US 20050069827A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2005/0069827 A1 Nariyuki et al. (43) Pub. Date: Mar. 31, 2005

(54) PHOTOSENSITIVE HALDE (30) Foreign Application Priority Data EMULSION, SILVER HALIDE PHOTOGRAPHC PHOTOSENSITIVE Aug. 28, 2003 (JP)...... 2003-209325 MATERIAL, PHOTOTHERMOGRAPHIC Aug. 28, 2003 (JP). ... 2003-209326 MATERIAL AND IMAGE-FORMING Sep. 22, 2003 (JP)...... 2003-329798 METHOD Publication Classification (76) Inventors: Fumito Nariyuki, Kanagawa (JP); Hiroyuki Mifune, Kanagawa (JP); (51) Int. Cl...... G03C 1/00 Kazutaka Takahashi, Kanagawa (JP); (52) U.S. Cl...... 430/619 Takayoshi Mori, Kanagawa (JP) (57) ABSTRACT Correspondence Address: The present invention a photothermographic material TAYO CORPORATION including: a Support; and an image-forming layer containing 2111 JEFFERSON DAVIS HIGHWAY a photoSensitive Silver halide, a non-photoSensitive organic #412, NORTH Silver Salt, a reducing agent for Silver ions and a binder on ARLINGTON, VA 2.2202 (US) at least one side of the Support, wherein the photosensitive Silver halide includes tabular grains with an average Silver (21) Appl. No.: 10/923,891 iodide content of 40 mol % or more, an average thickness whitin the range of 0.001 to 0.5 um and an average aspect (22) Filed: Aug. 24, 2004 ratio of 2 or more.

16O EMISSION SPECTRUM OF INTENSIFYING SCREEN A 14O 12O 1 OO 8O 6O 4O 2O O 25O 3OO 35O 4OO 45O 5OO 55O 6OO WAVELENGTH(nm) Patent Application Publication Mar. 31, 2005 US 2005/0069827 A1

F G. 1

16O EMISSION SPECTRUM OF INTENSIFYING SCREEN A D114O 212O 21 OO 8O 6O 4O 2O O 25O 3OO 35O 4OO 45O 5OO 55O 6OO WAVELENGTH (nm) US 2005/0069827 A1 Mar. 31, 2005

PHOTOSENSITIVE SILVER HALIDE EMULSION, exposure to form a black Silver image through an oxidation SILVER HALDE PHOTOGRAPHIC reduction reaction between a Silver halide or a reducible PHOTOSENSITIVE MATERIAL Silver Salt (functioning as an oxidizing agent) and a reducing PHOTOTHERMOGRAPHIC MATERIAL AND agent. The Oxidation-reduction reaction is accelerated by IMAGE-FORMING METHOD catalytic action of a latent image of Silver halide generated by exposure. As a result, a black Silver image is formed in CROSS-REFERENCE TO RELATED the exposed area. The photothermographic material is dis APPLICATION closed in many documents and FUJI MEDICAL DRY 0001) This application claims priority under 35 USC 119 IMAGER FM-DPL has been placed on the market as a from Japanese Patent Application Nos. 2003-209325, 2003 practical image-forming System for medical Services. 209326 and 2003-329798, the disclosures of which are 0008 Such an image-forming System using an organic incorporated by reference herein. Silver Salt has essentially two main problems, Since it is not Subjected to a fixing process, thereby allowing Silver halide BACKGROUND OF THE INVENTION to remain in a film even after development. 0002) 1. Field of the Invention 0009. One of the problems is deterioration of image 0003. The present invention relates to a photosensitive Storability, particularly that of printout when exposed to light Silver halide emulsion, a Silver halide photographic photo after development processing. As a technique to improve the Sensitive material, a photothermographic material and an printout, a method using is known. Compared image-forming method. Particularly, the invention relates to with or silver iodobromide containing 5 mol a photoSensitive Silver halide emulsion, a Silver halide % of iodine or less, Silver iodide has a property of being leSS photographic photoSensitive material, a photothermographic Susceptive to printout, which Suggests the possibility of material and an image-forming method using a Silver halide providing fundamental resolution of the problem. However, emulsion with a high content of silver iodide. Further, the the Silver iodide grain known until now has very low invention relates to a photoSensitive Silver halide emulsion, sensitivity which does not reach sensitivity that is usable for a Silver halide photographic photoSensitive material, a pho actual Systems. Further, there is an inherent problem Such tothermographic material and an image-forming method in that when a means for preventing recombination of a pho which Sensitivity is largely improved, fogging is reduced, toelectron and a positive hole is provided in order to increase and image storability after development is excellent. Sensitivity, the property of excellent printout is lost. 0004 2. Description of the Related Art 0010 AS for a means for increasing sensitivity of a silver iodide photographic emulsion, Sensitization by dipping it in 0005 Recently, in the fields of medical services and an aqueous Solution of a halogen receptor Such as Sodium printing and plate making, dry processing for photographic nitrite, pyrogallol or hydroquinone, or an aqueous Solution development is strongly desired from the viewpoints of of Silver , or by conducting Sulfur Sensitization at pAg environmental conservation and Space Saving. In these 7.5 has been known in academic literatures. However, the fields, digitalization has proceeded and Systems have rapidly Sensitization effect of these halogen receptorS is very slight Spread in which information is imported into a computer, and extremely insufficient in photothermographic material, Stored, processed if necessary, output to a photoSensitive which is the subject of the invention. material at a location where it is required by a laser image Setter or laser imager after being Sent by transmission, and 0011) Another problem is deterioration of image quality developed to form an image. It is required that the photo due to light Scattering by residual Silver halide, resulting in Sensitive material be capable of recording by laser exposure white turbidity of a film to make it translucent to opaque. In with high illumination intensity and that it forms a clear order to Solve this problem, a means was adopted as a black image having high resolution and Sharpness. AS practical means Such that photoSensitive Silver halide was recording materials for Such digital imaging, various hard made into fine grains (in a practical region, from 0.15 um to copy Systems using pigment or dye Such as an inkjet printer 0.08 um) and the addition amount thereof was reduced as far and an electrophotographic System are in circulation as as possible to decrease white turbidity caused by Silver general image-forming Systems. However, they are not halide. However, the compromise further reduces Sensitivity, Satisfactory with respect to image quality (sharpness, graini and does not completely correct the white turbidity, leaving ness, gradation, and color tone) which determines diagnostic the film opaque to give a haze thereto. capability, and recording speed (Sensitivity), in the case of a 0012. In the case of wet development processing, residual medical image. Thus, they have not reached a level capable Silver halide is removed by processing with a fixing liquid of replacing conventional wet development medical Silver containing a Solvent for Silver halide after development Salt film. processing. AS for the Solvent for Silver halide, various 0006 A thermal image-forming System using organic inorganic and organic compounds that can form a complex Silver Salt is already known. A photoSensitive material used with a silver ion are known. in the System includes an image-forming layer in which a 0013 In dry thermal development processing, it was reducible Silver Salt (for example, an organic Silver Salt), a attempted in the past to incorporate similar fixing means. For photoSensitive Silver halide and, according to need, a color example, a method, in which a compound capable of form toning agent for controlling color tone of Silver are dispersed ing a complex with a Silver ion is incorporated in the film to in a matrix of a binder. make silver halide soluble by thermal development (usually 0007. A photothermographic material is heated to a high called “fixing'), has been proposed (refer to Japanese Patent temperature (for example, 80 C. or higher) after image Application (JP-A) No. 8-76317). However, the method is US 2005/0069827 A1 Mar. 31, 2005

related to silver bromide or silver chlorobromide and further pletely different effect can be expected from the compound. requires post-heating for fixation in which a heating condi Further, it could never be conceived of applying the com tion of a high temperature in the range of 155 C. to 160 C. pound to photothermographic material using a high Silver is necessary, making the System difficult to fix. Further, a iodide content emulsion, and therefore speculation of the method, in which a separate sheet (fixing sheet) containing effect thereof was also impossible. a compound capable of forming a complex with a Silver ion 0020. On the other hand, it has been proposed to attempt is prepared to dissolve and remove residual Silver halide by to apply the above-described photothermographic material laminating the sheet on a photothermographic material that to a photoSensitive material for photographing. A photosen has been thermally developed to form an image and heating Sitive material for photographing here means one on which the laminate, has been proposed (refer to JP-A No. an image is recorded by Surface exposure instead of Scan 9-166845). However, since the system includes two sheets, exposure in which image information is written by laser there are drawbacks from a practical Standpoint Such that light. Conventionally, Such a photoSensitive material has processing becomes complicated to make Securing Stable been generally used in the field of wet developing photo action of the process difficult, and that waste material is Sensitive material. Direct or indirect X-ray film and mam generated after the processing Since it is necessary to dispose mography film for medical application, various plate making the fixing Sheet. films for printing, recording film for industrial application 0.014. As an additional fixing method in thermal devel and film for photographing by a general camera are known. opment, a method has been proposed in which a fixing agent For example, patent documents disclose a double-side for Silver halide is incorporated in microcapsules to allow coated type photothermographic material for X-rays utiliz the fixing agent to be released and act due to the thermal ing a blue fluorescent intensifying Screen (for example, refer development (refer to JP-A No. 8-82886). However, it is to Japanese Patent No. 3229344), a photothermographic difficult to achieve a design that makes the fixing agent material utilizing tabular grains of silver iodobromide (for release effectively. Another method has been proposed in example, refer to JP-A No. 59-142539), and a photosensitive which fixation is conducted by using a fixing Solution after material for medical Services in which tabular gains con thermal development (refer to JP-A Nos. 51-104826 and taining a high content of with a (100) 62-133454). However, since wet processing is required, the principal plane are coated on both sides of a Support (for method is unsuitable for totally dry processing. example, refer to JP-A No. 10-282606). Further, double Side-coated type photothermographic materials are also dis 0015. As described above, every conventionally known closed in other patent documents. However, in these prior method for improving turbidity of the film has a large examples, use of fine grain Silver halide with a size of 0.1 um adverse effect to make practical use thereof difficult. or leSS results in low Sensitivity, although it is not accom 0016. In addition, it is known that a higher sensitivity can panied by deterioration of haze, to make practical use for be obtained in the liquid development System by depositing photographing almost impossible. On the other hand, use of a silver Salt on a host Silver halide grain by epitaxial growth Silver halide gains having a size of 0.3 um or more results or introducing dislocation lines on Silver halide. in Significant degradation of image quality caused by dete rioration of haze and print out due to residual Silver halide 0.017. However, in silver halide photosensitive material to make practical use almost impossible. in the liquid development System, generally, Silver images are formed by reducing Silver halide by a developing agent 0021 A photosensitive material using tabular silver (reducing agent) contained in a processing Solution, or color iodide grains as Silver halide grains is known in the field of images are formed by using an oxidized developing agent wet developing (for example, refer to JP-A Nos. 59-119344 which is a by-product, that is, a fundamental reaction is and 59-119350). However, there is no example of applica reduction of Silver halide by a developing agent. tion in photothermographic material. The reason is, as described above, due to low sensitivity, lack of effective 0.018. On the other hand, in photothermographic material, means for Sensitization and a further higher technical barrier Silver halide forms only a latent image by exposure and in thermal development. silver halide itself is not reduced by a reducing agent. What is reduced in the material is Silver ions Supplied from a 0022. In order to use as such a photosensitive material for non-photoSensitive organic Silver Salt. AS for a reducing photographing, photothermographic material is required to agent also, an ionic reducing agent Such as hydroquinone or have a further higher Sensitivity, and a further higher level p-phenylenediamines is used in the case of liquid develop in image quality Such as haze of an obtained image. ment, but a hindered phenol derivative generally known as 0023) A technique is disclosed (JP-A No. 62-133454) in a radical reactive agent is used in the case of photothermo which a silver salt Such as silver chloride or silver bromide graphic material. is epitaxially grown on tabular Silver iodide grains to be used 0.019 Thus, mechanisms of development reactions for multicolor image color Silver halide Salt photoSensitive (reducing reaction) in liquid development processing pho material. Further, the Specification discloses that the Silver toSensitive material and photothermographic material are halide is Subjected to chalcogen Sensitization, gold-chalco completely different from each other, and compounds used gen Sensitization or reduction Sensitization. However, the are also completely different from each other. Accordingly, Specification only discloses use of the tabular Silver iodide it cannot be Supposed that compounds that are effective in grains in wet processing color Silver Salt photoSensitive liquid development processing will be directly effective for material, and there is no description or disclosure about photothermographic material. When a compound is applied photothermographic material. to photothermographic material, it can never be predicted 0024. Accordingly, a silver halide emulsion, a silver whether the same effect will be given or whether a com halide photographic photoSensitive material, a photothermo US 2005/0069827 A1 Mar. 31, 2005 graphic material and an image-forming method with high 0035. The distribution of halogen composition of each Sensitivity, low fog and excellent image Storability are grain may be uniform, or the halogen composition may required, the Silver halide emulsion, the Silver halide pho Stepwise change or may continuously change in each grain. tographic photoSensitive material, the photothermographic Further, Silver halide grains with a core/shell Structure can material and the image-forming method utilizing a high also be preferably used. The structure is preferably a two- or content of silver iodide. five-layered Structure. Core/shell grains with a two- to four-layered Structure can be more preferably used. Grains 0.025 Moreover, there is a need for a photothermographic having a core/shell Structure in which the core has a high material with low haZe and an image-forming method. silver iodide content or in which the shell has a high silver SUMMARY OF THE INVENTION iodide content can also be preferably used. 0026. A first aspect of the present invention provides a 0036) The tabular grains in the invention preferably has photothermographic material including: a Support; and an an epitaxial junction, in which Silver chloride or Silver image-forming layer containing a photoSensitive Silver bromide is localized, at the Surfaces thereof. halide, a non-photosensitive organic Silver Salt, a reducing 0037. The halogen composition in the epitaxial portion agent for Silver ions and a binder on at least one side of the may be uniform or the halogen composition in the Spatial Support, wherein the photosensitive Silver halide includes portion may stepwise change or continuously change. The tabular grains with an average Silver iodide content of 40 ratio of the Silver iodide content in the epitaxial portion to mol % or more, an average thickness within a range of 0.001 the host tabular grain is preferably 1/2 or less, more pref to 0.5 um and an average aspect ratio of 2 or more. erably 1/3 or less, still more preferably 1/5 or less and most 0027. A second aspect of the invention provides a method preferably 1/10 or less. In this case, it is preferable that the for forming an image on the photothermographic material, Silver iodide content in the epitaxial portion is Smaller than the method including: disposing the photothermographic that in the host tabular grain. material between a pair of X-ray intensifying Screens to 0038. In the halogen composition other than the silver obtain an assembly for image formation, arranging a Subject iodide in the epitaxial portion, it is preferable that the between the assembly and an X-ray Source; irradiating the content of silver bromide or silver chloride is high. More Subject with X-rays having an energy level in a range of 25 preferably, the Silver bromide content in the epitaxial portion kVp to 125 kVp, removing the photothermographic material is 60 mol % or more, still more preferably 80% or more and from the assembly; and heating the removed photothermo most preferably 90 mol % or more. graphic material at a temperature in a range of 90° C. to 180 C. 0039. In the invention, the silver iodide can have an arbitrary content of 3-phase and gamma phase. The B-phase BRIEF DESCRIPTION OF THE DRAWING indicates a high Silver iodide Structure with Wurtzite Struc ture of hexagonal System. The gamma phase indicates a high 0028 FIG. 1 shows an emission spectrum of fluorescent silver iodide structure with zinc blend structure of cubic intensifying Screen A. System. The gamma phase content herein means that deter mined by using a technique proposed by C. R. Berry. In the DETAILED DESCRIPTION OF THE technique, determination is conducted on the basis of the INVENTION ratio of peaks according to Silver iodide f-phases (100), 0029. Hereinafter, the invention will be described in (101) and (002), and gamma phase (111) in powder X-ray detail. diffraction method. The details of the technique is described in, for example, Physical Review Vol. 161, No. 3, pp 0030) 1. Photosensitive Silver Halide Emulsion 848-851 (1967). 0031) 1-1 Photosensitive Silver Halide 0040 2) Grain Shape 0032) 1) Halogen Composition 0041. The silver halide grains in the invention are tabular 0033. It is important that a photosensitive silver halide grains. used in the invention should have a high silver iodide content within the range of 40 mol % to 100 mol%. Residual 0042. The tabular grains in the invention are preferably portion in the Silver halide composition is not particularly formed by a nucleus forming process and a grain growing restricted, and can be Selected from Silver halide Such as process. In the grain growing process, Silver halide fine Silver chloride, and Silver bromide, and organic Silver Salt particles having a size Smaller than the average thickness of Such as Silver and . Among the tabular grains to be formed are preferably added to a them, silver bromide and/or silver chloride is particularly reaction System. In this case, adding the Silver halide fine preferable. Use of the silver halide having a high silver particles having the size Smaller than the average thickneSS iodide content allows design of a preferable photothermo is preferably conducted such that the amount of the silver graphic material with an excellent image Storability, espe halide fine particles added are 10 mol% or more of the entire cially with Significantly Small increase in fogging caused by Silver amount the tabular grains. The average grain size of light exposure after development. the Silver halide fine particles added in the grain growing 0034) Further, the silver iodide content is preferably in process is 0.0005 to 0.04 um and more preferably 0.0005 um the range of 80 mol % to 100 mol %, and more preferably to 0.025um. in the range of 90 mol % to 100 mol % from the viewpoint 0043. The average aspect ratio of the tabular grains is of image Storability with respect to light exposure after preferably 2 or more, more preferably from 2 to 50, still development. more preferably from 8 to 50, and furthermore preferably US 2005/0069827 A1 Mar. 31, 2005 from 12 to 50. Alternatively, the aspect ratio of the tabular invention, the average Sphere equivalent diameter is prefer grains is preferably 2 or more, more preferably 5 or more, ably in the range of 0.2 to 10.0 um, more preferably in the and still more preferably 8 or more. Alternatively, the range of 0.3 to 5.0 um, still more preferably in the range of average aspect ratio of the tabular grains in the invention is 0.35 to 3.0 lum, and most preferably 0.5 to 3.0 lum. In the preferably 5 to 70. invention, the average projected area equivalent diameter of 0044 Alternatively, at least a part of the tabular grains, the silver halide grains is preferably in the range of 0.1 to 5 the entire projected area of which part corresponds to 50% lum and more preferably in the range of 0.3 to 3 lum. The size or more of the entire projected area of all the tabular grains, distribution of the tabular grains in the invention is prefer preferably has an aspect ratio of 2 or more, and more ably mono-dispersion. The variation coefficient of projected preferably are grains in which Silver Salt has been deposited area equivalent diameters of the grains is preferably 25% or on Silver halide tabular grains having an aspect ratio in the less and more preferably 20% or less. The projected area range of 2 to 100 by epitaxial growth. equivalent diameter herein means the diameter of a circle 0.045 Alternatively, at least a part of the tabular grains, having the same area as the area of a Silver halide grain. The the entire projected area of which part corresponds to 50% Sphere equivalent diameter herein means the diameter of a or more of the entire projected area of all the tabular grains, Sphere having the same Volume as the Volume of a Silver preferably has an aspect ratio of 3 to 100 and more prefer halide grain. The projected area equivalent diameter and the ably has an aspect ratio in the range of 5 to 50. Sphere equivalent diameter can be obtained by observing a grain with an electron microscope, measuring the projected 0046) The average thickness of the tabular grains is preferably 0.001 to 0.5 tim, more preferably 0.01 to 0.5 tim, area and the thickness of the grain, obtaining therefrom the still more preferably 0.02 to 0.2 tim, and most preferably projected area and the Volume of the grain, and calculating 0.02 to 0.1 um. The average thickness of the tabular grains the diameter of a sphere having the same Volume as the grain is 0.001 to 0.2 tim, more preferably 0.001 to 0.1 um and still Volume and the diameter of a circle having the same area as more preferably 0.001 to 0.05um. the projected area. 0047 Alternatively, the average thickness of the silver 0051. The silver halide grains in the invention are pref halide grains in the invention is within the range from 20 nm erably tabular grains. Examples of the tabular grains include less than to 20 nm more than a thickness at which reflectance tabular octahedron grains, tabular tetradecahedron grains becomes maximum in the wavelength range in which the and tabular icosahedron grains which are classified accord Silver halide emulsion has Sensitivity. The average thickneSS ing to Side face Structures. The tabular octahedron grains and is preferably within the range from 15 nm less than to 15 nm tabular tetradecahedron grains are preferable. The tabular more than the thickness, and more preferably within the octahedron grains herein mean grains having {001}, {100 range from 10 nm less than to 10 nm more than the and {001} planes, or grains having {001}, {120 and thickness. In the Silver halide grains of high Silver iodide {1(-1)0 planes. The tabular tetradecahedron grains mean content in the invention, a particularly high Sensitivity can grains having {001}, {100}, {010}, {101 and {011 be obtained by Setting the average thickneSS in this specific planes, grains having {001}, {120}, {1(-1)0}, {121} and range. {1(-1)1)}planes, grains having {001)}, {101}, {011, 10(- 1)} and {01(-1)} planes, or grains having {001}, {121}, 0.048. In the silver halide tabular grains with a high silver {1(-1)1}, {12(-1)} and {1(-1) (-1)} planes. The tabular iodide content, reflectance to incident light depends on an icosahedron grains mean grains having {001}, {100, exposure wavelength (incident light wavelength) and the {010}, {101}, {011, 10(-1)} and {01(-1)} planes, or thicknesses of the Silver halide grains. Thicknesses which grains having {001}, {120}, {1(-1)0}, {121}, {1(-1)0}, result in maximum reflectance exists periodically. When the {12(-1)} and {1(-1)(-1)} planes. Here, indications such as photographic material of the invention including grains {001} represent crystal planes having plane indices equiva which has a high Silver iodide content is exposed to light in the wavelength range in which the grains have intrinsically lent to the plane index of (001) plane. In addition, tabular sensitivity (0=350 to 450 nm), a first thickness range effec grains with other shapes are also preferably used. tive in the invention is the range of less than 0.1 um, and a 0052 Silver halides with a high silver iodide content may Second thickness range is the range of 0.1 um to 0.2 um. have a complex form. The silver halide is preferably junc Although the effective thickness depends on the silver iodide tion particles shown in, for example, FIG. 1 of R. L. Jenkins content, in pure Silver iodide, the first thickness range is the et al., J of Phot. Sci. Vol. 28 (1980) P164. The tabular grains range whose center is 0.046 um, and the Second thickness shown in FIG. 1 of the Journal can also be preferably used. region is the range whose center is 0.14 um. Silver halide grains having rounded corners are also pref 0049 Further, when the grains are subjected to spectral erably used. There is no particular restriction on the plane Sensitization in a specific region of Spectrum, wavelengths at index of the outer surface (Miller index) of the photosensi tive silver halide grain. However, it is preferable that the rate which the reflectance becomes maximum there exist. The of 100 plane, which has a high spectral Sensitization effect thicknesses effective for the wavelengths are different from when the photoSensitive Silver halide adsorbs a spectral each other. For example, when the center of exposure Sensitizing dye, is high. The rate is preferably 50% or more, wavelength is 550 nm, the thickness range whose center is more preferably 65% or more, and still more preferably 80% 0.063 um is preferable. When the center of exposure wave or more. The Miller index and the rate of 100 plane can be length is 650 nm, the thickness range whose center is 0.077 obtained according to a method using adsorption depen tum is preferable. dency of 111 plane and 100 plane in adsorption of a 0050. The silver halide grains of the invention having a Sensitizing dye, the method being described in T. Tani; J. high Silver iodide content may have any grain size. In the Imaging Sci., 29,165 (1985). US 2005/0069827 A1 Mar. 31, 2005

0.053 Plane indices of main planes of the outer surface known for their capability of epitaxially growing on Silver can be obtained by Subjecting the Surface to epitaxial halide grains and effectiveness in photography. In particular, junction of a structure with known crystal orientation, for the silver salt is preferably selected from those convention example, Silver bromide grains. ally known for their effectiveness for formation of the shell 0.054 Terms “epitaxy' and “epitaxial herein have mean of a core-shell silver halide emulsion. In addition to all the ings accepted in the art in order to indicate that a Silver Salt known and photographically useful Silver halides, other has a crystal form with an orientation which can be con Silver Salts known for their capability of depositing on the trolled by a host tabular grain. Silver halide grains as a Silver Salt, Such as , , Silver ferricyanide, or Silver 0055. In order to form a sensitization site on host tabular arsenite, and can be used. Further, mixtures grains, a Silver Salt deposited by epitaxial growth can be thereof may be usable. Among them, Silver chloride, Silver utilized. By controlling a deposition Site through epitaxial bromide and Silver thiocyanate, and mixtures thereof are growth, Selectively localized Sensitization of the host tabular preferable. The silver salt particularly preferably includes at grains can be conducted. Accordingly, the Sensitization site can be disposed at one or more regular Sites. Term “regular least silver bromide. means that the Sensitization sites have an expectable orderly 0060. By allowing a modifying compound to exist relation between themselves and the principal crystal plane together with the tabular Silver halide grains, the Silver Salt of the tabular grain. IS is preferable that the Sensitization can be effectively deposited in accordance with a Selected Sites and the principal crystal plane mutually have Such a Silver Salt and intended application. Iodide may migrate relation. Control of epitaxial deposition with respect to the from the host grains into Silver Salt epitaxy. The host grains principal crystal plane of the tabular grain allows the number may contain anions other than iodide ions up to and the distance in the horizontal direction of the Sensitiza limit to silver iodide. tion sites to be controlled. 0061 The silver halide in the invention preferably has at 0056. In particular, it is preferable to substantially least one dislocation line. The silver halide more preferably exclude epitaxial deposition at at least a part of the principal has 5 dislocation lines or more, and particularly preferably crystal plane of the host tabular grain by controlling Silver has 10 dislocation lines or more. It is preferable that at least Salt exitaxy. In the host tabular grains, epitaxial deposition of a part of the tabular grains, the entire projected area of which the Silver Salt tends to occur at edges and/or corners of the part corresponds to 50% or more of the entire projected area grains. of all the tabular grains, include one dislocation line or more. 0057 Limitation of epitaxial deposition to a selected site It is more preferable that at least a part of the tabular grains, or Sites of the tabular grains provides more improved the entire projected area of which part corresponds to 80% Sensitivity than random deposition of the Silver Salt on the or more of the entire projected area of all the tabular grains, principal plane of the tabular grains due to epitaxial growth. include one dislocation line or more. It is particularly At least a part of the principal crystal plane is Substantially preferable that at least a part of the tabular grains, the entire forbidden to be subjected to epitaxial deposition of the silver projected area of which part corresponds to 80% or more of Salt, and the Silver Salt is allowed to deposit on a Selected Site the entire projected area of all the tabular grains, include ten or Sites in a limited range. The deposition range can be dislocation lines or more. broadly changed without deviating from the invention. Gen erally, the Smaller the covering amount of epitaxial on the 0062 Dislocation of silver halide crystal is described in, principal crystal plane, the larger the Sensitivity. The Silver for example, the following documents. Salt is preferably deposited by epitaxial growth on less than half of the area of the principal crystal planes of the tabular 0063. 1) C. R. Berry, J. APP1. Phys., 27, 636 (1956), grains, and more preferably on less than 25% of the area. 0064. 2) C. R. Berry, D. C. Skilman, J. APP1. Phys., 35, When the silver salt is deposited by epitaxial growth on the 2165 (1964), corners of the tabular Silver halide grains, the are of Sites having epitaxial deposition is preferably less than 10%, and 0065 3) J. F. Hamilton, Phot. Sci. Eng., 11, 57 (1967), more preferably less than 5% of the area of the principal crystal planes of the tabular grains. In Some embodiments, it 0066 4) T. Shiozawa, J. Soc. Phot. Sci. JAP., 34, 16 is observed that epitaxial deposition Starts at the edge (1971), and Surfaces of the tabular grains. Accordingly, depending on 0067 5) T. Shiozawa, J. Soc. Phot. Sci. JAP., 35,213 conditions, epitaxy is limited to Selected edge Sites to effectively exclude epitaxy on the principal crystal plane. (1972). 0.058 Complete development of grains including a latent 0068 They describe that observation of dislocation in a image center makes it impossible to determine the position crystal is possible by an X-ray diffraction method or trans and the number of the latent image centers. However, when mission electron microscopic method at a low temperature, development before extension of a developed area from a and that various dislocations occur in a crystal by giving position close to the latent image center is inhibited and the Strain to the crystal. partially developed gains are magnified and the magnified 0069. On the other hand, influence of dislocation on grains are observed, the partially developed Sites can be photographic properties is described in, for example, G. C. clearly Seen. These Sites generally correspond to the latent Fame 11, R. B. Flint and J. B. Chanter, J. Phot. Sci., 13, 25 image centers, and the latent image centers generally cor (1965). It shows that, in tabular silver bromide grains with respond to the Sensitization sites. a large Size and a high aspect ratio, affinity exists between 0059 A silver salt to be deposited by epitaxy can be places where latent image nucleuses are formed and defects Selected from any of Silver Salts conventionally generally in the grains. US 2005/0069827 A1 Mar. 31, 2005

0070 JP-A Nos. 63-220238 and 1-201649 disclose tabu pI. p is a logarithm of the inverse of iodide ion concentra lar Silver halide grains to which dislocation has been inten tion in a System. In the invention, an aqueous Solution of tionally introduced. The tabular grains to which dislocation and an aqueous halogen Solution are particu has been introduced have better photographic properties larly preferably added to the System at a temperature within Such as Sensitivity, and reciprocity law than tabular grains the range of 20° C. to 80°C. in the presence of gelatin while without dislocation. The application also shows that use of the System is being Stirred. At this time, pI of the System is the tabular grains with dislocation for photoSensitive mate preferably 3 or less and pH of the system is preferably 7 or rial results in excellent sharpness and grainineSS. leSS. The concentration of the aqueous Solution of Silver 0071. However, dislocation lines are irregularly intro nitrate is preferably 1.5 mol/L or less. duced to the edges of these tabular grains and every grain 0081. The aging step is preferably conducted at a tem has the different number of dislocations. perature within the range of 50° C. to 80 C. Further, an additional amount of gelatin is preferably added within a 0072 3) Coating Amount period from a time just after the nucleus formation to 0073. The coating amount of silver halide can be arbi completion of aging. trarily Selected in accordance with application and object. 0082 The growing step in the invention may be con 0.074. In the case of general silver halide photosensitive ducted either by adding a halogen ion-containing Solution materials for wet development System, there is no particular including iodide and a Solution containing AgNO, or by restriction on the amount of the silver to be applied. When adding Silver iodide fine grain emulsion. The Silver halide a high image density is required, the Silver halide is usually fine grain emulsion may be added alone, or the aqueous used in a silver amount of 1 g/m to 10 g/m. When a not so Solution of Silver nitrate, the halogen-containing aqueous high image density is required, the Silver halide is usually Solution containing the iodide and the Silver iodide fine grain used in a silver amount of 0.1 g/m to 5 g/m. emulsion can be simultaneously added. 0075 Generally, in the case of photothermographic mate 0083. In the invention, a growing step at least including rial, in which Silver halide remains as it stands even after the addition of the Silver iodide fine grain emulsion is thermal development, an increased coated amount of Silver preferred. The Silver iodide fine grain emulsion means an halide results in reduction of transparency of the film, which emulsion which includes grains having a size Smaller than is undesirable for image quality. Therefore, contrary to a the average thickness of the tabular grains. Further, the demand for a higher Sensitivity, the coated amount has been addition of the silveriodide fine grain emulsion is preferably restricted to a low value. However, in the invention, Since at least 10 mol % with respect to the entire amount of silver haze of the film caused by silver halide can be decreased by during growing. thermal development, a larger amount of Silver halide can be applied. In the invention, the amount of the Silver halide to 0084. The silver iodide fine particle emulsion in the be applied is preferably from 0.5 mol % to 100 mol %, and invention may be substantially made of silver iodide and more preferably from 5 mol % to 50 mol % per mol of silver may also contain Silver bromide and/or Silver chloride So of a non-photosensitive organic Silver Salt described later. long as mixed crystals can be formed. The emulsion is preferably made of 100% silver iodide. 0076 4) Grain Formation Method 0085. The silver iodide can have the following crystal 0077. A method for forming photosensitive silver halide Structures: beta phase, gamma phase, and alpha phase or a is well known in the art, and the Silver halide can be prepared structure similar to the alpha phase as describe in U.S. Pat. according to a conventionally known method. In particular, No. 4,672,026. The crystal structure is not limited in the the Silver halide employed in a photothermographic material invention, however a mixture of the beta phase and the is prepared by, for example, methods described in Research gamma phase is preferably used and the beta phase is more Disclosure, No. 17029, June 1978 and U.S. Pat. No. 3,700, preferably used. 458. Specifically, a method is employed in which photosen Sitive Silver halide is prepared by adding a Silver-donating 0086 The silver iodide fine grain emulsion may be compound and a halogen-donating compound to a Solution formed just before addition as described, for example, in including gelatin or other polymer followed by blending the U.S. Pat. No. 5,004,679, or may undergo an ordinary water resultant with an organic Silver Salt. In addition, a method Washing Step. In the invention, those which have undergone described in JP-A No. 11-119374, paragraphs 0217 to the ordinary water Washing Step are preferably used. 0224) and methods described in JP-A Nos. 11-352627 and 0087. The silver iodide fine grain emulsion can be easily 2000-347335 are also preferable. formed by a method described in, for example, U.S. Pat. No. 0078. As for a method for preparing silver iodide tabular 4,672,026. A double jet addition method in which an aque grains, methods described in aforementioned JP-A Nos. ous Silver Salt Solution and an aqueous iodide Salt Solution 59-119350 and 59-119344 are preferably used. are added to a System in grain formation while keeping the pI value constant during the grain formation is preferred. 0079 Preparation of the tabular grains in the invention There are no particular restrictions on temperature, pI, pH, may be conducted by any of grain formation methods the kind and the concentration of a protective colloid agent including three Steps of nucleus formation, aging and grow Such as gelatin, absence or presence, the kind and the ing, those including two steps of nucleus formation and concentration of a solvent for Silver halide. However, it is growing, and those including one Step in which nucleus advantageous in the invention that the grain size is from formation and growing are conducted. 0.0005um to 0.1 um, preferably from 0.0005um to 0.07 um, 0080. In the nucleus formation step, nucleus formation more preferably from 0.0005 um to 0.04 um and particularly can be preferably conducted in a short period of time at low preferably from 0.0005 um to 0.025 um. It is also advanta US 2005/0069827 A1 Mar. 31, 2005

geous that the variation coefficient of the grain size distri are described in JP-A Nos. 7-225449, 11-65021, paragraphs bution is 18% or less. Since the silver halide grains are fine, 0018 to 0024), and 11-119374, paragraphs 0227 to the grain shapes cannot be completely defined. However, the O240). variation coefficient of the grain size distribution is prefer 0094. In the invention, silver halide grains in which a ably 25% or less. hexacyano-metal complex is allowed to exist on the upper 0088. The effect of the invention is particularly remark most Surface of the grains are preferable. Examples of the able when the variation coefficient is 20% or less. After hexacyano-metal complex include Fe(CN), Fe(CN), Silver iodide fine grains grains contained in the Silver iodide , Ru(CN), Os(CN), Co(CN), Rh(CN), fine grain emulsion are placed on a mesh for electron Ir(CN), Cr(CN), and Re(CN). In the inven microscopic observation, the Size and the Size distribution tion, a hexacyano-iron complex is preferable. thereof are obtained not by a carbon replica method but 0095 Since the hexacyano-metal complex exists in the directly by observation using a transmission method. form of ions in an aqueous Solution, its counter cation is not 0089. This is because the grain size is small and therefore important. However, use of an alkali metal ion Such as a measuring error increases under the observation by the Sodium ion, a potassium ion, a rubidium ion, a cesium ion carbon replica method. The grain size is defined as the or a lithium ion, an ammonium ion, or an alkilammonium diameter of a circle having the same area as the projected ion (e.g., a tetramethylammonium ion, a tetraethylammo area of the observed grain. The grain size distribution is also nium ion, a tetrapropylammonium ion or a tetra(n-butyl)am determined by using Such diameters. monium ion), which is easily miscible with water and Suitable for precipitation operation of the Silver halide 0090. In principle, growing occurs by Ostwald ageing so emulsion, is preferable as the counter cation. long as the Size of each of the added fine grains in the emulsion is Smaller than the average thickness of the tabular 0096. The hexacyano-metal complex can be added in the grains. For the tabular grainS with the average Silver iodide form of mixture of the complex and a Solvent Such as water, content of 40 mol % or more, it is desirable that the size is a mixed Solvent of water and a Suitable organic Solvent Smaller and that the variation coefficient of the grain size miscible with water Such as an alcohol, an ether, a glycol, a distribution is Smaller. ketone, an ester, or an amide, or gelatin. 0097. The addition amount of the hexacyano-metal com 0.091 The method used most preferably in the growing plex preferably ranges from 1x10 mol to 1x10 mol, and Step of the invention is similar to a method described in JP-A more preferably from 1x10" mol to 1x10 mol per mol of No. 2-188741. In the method, an emulsion including fine silver. grains of silver iodide, silver bromide, or silver chloride which have been prepared just before addition is continu 0098. In order to allow the hexacyano-metal complex to ously added to a System during growing of tabular grains to exist on the outermost Surface of the Silver halide grains, the dissolve the ultrafine grains contained in the emulsion and hexacyano-metal complex is directly added to a System after grow the tabular grains. An external mixer for preparing the completion of adding an aqueous Solution of Silver nitrate fine grain emulsion has an intense Stirring power and an used in grain formation, and before completion of feeding aqueous Solution of Silver nitrate, an aqueous halogen Solu process (i.e., before chemical sensitization process perform tion and gelatin are placed in the mixer. The gelatin can be ing chalcogen Sensitization Such as Sulfur Sensitization; added as a mixture of the gelatin and at least one of the Selenium Sensitization or tellurium Sensitization or noble aqueous Solution of Silver nitrate and the aqueous halogen metal sensitization Such as gold Sensitization), during water Solution which mixture has been prepared previously or Washing process, during dispersion process or before chemi immediately before addition, or an aqueous gelatin Solution cal Sensitization process. In order not to allow Silver halide can be added alone. The gelatin preferably has a molecular fine grains to grow, it is preferable that addition of the weight Smaller than that of ordinary gelatin, and particularly hexacyano-metal complex after grain formation is rapidly preferably has a molecular weight of 10,000 to 50,000. The conducted. The hexacyano-metal complex is preferably gelatin is preferably at least one Selected from gelatin in added before completion of feeding process. which 90% or more of amino groups have been phthalized, 0099. The addition of the hexacyano-metal complex may Succinated or trimelitated, and oxidized gelatin with a be started after the addition of Silver nitrate used in the grain lowered methionine content. Gelatin which has undergone formation has proceeded by 96 mass %, preferably after the phthalizing modification is particularly preferable. addition has proceeded by 98 mass %, and more preferably 0092 5) Heavy Metal after the addition has proceeded by 99 mass %. 0093. The photosensitive silver halide grains in the 0100 Addition of the hexacyano-metal complex after invention can contain a metal which belongs to any of 6 to adding an aqueous Solution of Silver nitrate to be added just 13 groups (preferably 6 to 10 groups or 8 to 10 groups) of before completion of the grain formation allows the silver the periodic table including 1 to 18 groups, or a metal halide grains to adsorb the complex on the Outermost Surface complex thereof. The metal or the central metal of the metal thereof, and most of the complex forms a hardly soluble salt complex is preferably rhodium, ruthenium, iridium or iron. with silver ions on the surfaces of the grains. The silver salt A Single kind of metal complex may be used alone, or two of hexa-iron (II) is more hardly soluble than AgI, and or more kinds of metal complexes including the same kind therefore re-dissolution caused by that the grains are fine can of metal or different kinds of metals may be used as a be prevented. Thus, production of Silver halide fine grains mixture. The content thereof is preferably in the range of with a Small grain size has become possible. 1x10 mol to 1x10 mol per mol of silver. The heavy 0101) Further, a metal atom (e.g., Fe(CN) ) that can metals, the metal complexes and addition methods thereof be incorporated in the Silver halide grains used in the US 2005/0069827 A1 Mar. 31, 2005 invention, a desalting method and a chemical Sensitization in JP-B Nos. 46-4553 and 52-34492) such as selenious acid, method of the silver halide emulsion are described in JP-A Selenocyanates, Selenazoles and Selenides may also be used. Nos. 11-84574, paragraphs 0046 to 0050), 11-65021, In particular, phosphine Selenides, Selenoureas and Seleno paragraphs 0.025 to 0031) and 11-119374, paragraphs cyanates are preferable. 0242 to 0250). 0110. In the tellurium sensitization, a labile tellurium 0102) 6) Gelatin compound is used and labile tellurium compounds described 0103) The photosensitive silver halide emulsion used in in JP-A Nos. 4-224.595, 4-271341, 4-333043, 5-303157, the invention may include any gelatin, but phthalated gelatin 6-27573, 6-175258, 6-180478, 6-208186, 6-208184, is preferable. In order to keep the dispersion State of the 6-317867, 7-140579, 7-301879 and 7-301880 can be used. gelatin good in a coating liquid including the photoSensitive 0111 Specifically, examples thereof include phosphine Silver halide emulsion and an organic Silver Salt, use of tellurides (e.g., butyl-diisopropylphosphine telluride, tribu gelatin having a low molecular weight ranging from 500 to tylphosphine telluride, tributoxyphosphine telluride, and 60,000 is preferable. Such low molecular weight gelatin may ethoxydiphenylphophine telluride), diacyl (di)tellurides be used during grain formation, or during dispersion which (e.g., bis(diphenylcarbamoyl) ditelluride, bis(N-phenyl-N- is conducted after desalting process, and use thereof during methylcarbamoyl) ditelluride, bis(N-phenyl-N-methylcar dispersion conducted after desalting proceSS is preferable. bamoyl) telluride, bis(N-phenyl-N-benzylcarbamoyl) tellu ride, and bis(ethoxycarbonyl) telluride), telluroureas (e.g., 0104 7) Chemical Sensitization N,N'-dimethylethylenetellurourea, and N,N'-diphenylethyl 0105 The photosensitive silver halide used in the inven enetellurourea), telluroamides and telluroesters. In particu tion may not be Subjected to chemical Sensitization, but is lar, diacyl (di)tellurides and phosphine tellurides are pref preferably Subjected to chemical Sensitization by at least one erable and compounds described in documents described in of a chalcogen Sensitization method, a gold Sensitization JP-A No. 11-65021, paragraph 0030) and compounds rep method and a reduction Sensitization method. The Silver resented by formula (II), (III) or (IV) in JP-A No. 5-313284 halide may be Sensitized by a gold-chalcogen Sensitization are more preferable. method. Examples of the chalcogen Sensitization method 0112 In particular, the chalcogen sensitization in the include a Sulfur Sensitization method, a Selenium Sensitiza invention is preferably Selenium Sensitization or tellurium tion method and a tellurium Sensitization method. Sensitization and more preferably tellurium Sensitization. 0106 In the sulfur sensitization, a labile sulfur compound 0113. In the gold sensitization, a gold sensitizer described is used. As the labile Sulfur compound, those described in P. in P. Grafkides, Chimie et Physique Photographique, 5th Grafkides, Chimie et Physique Photographique, 5th Ed., Ed., Paul Momtel (1987) and Research Disclosure, vol. 307, Paul Momtel (1987), and Research Disclosure, vol. 307, No. No. 307105 may be used. Specific examples thereof include 307150 can be utilized. chloroauric acid, potassium chloroaurate, potassium 0107 Specifically, a known sulfur compound such as aurithiocyanate, gold Sulfide, gold Selenide, and gold 5,049, thiosulfates (e.g., hypo), thioureas (e.g., diphenylthiourea, 485, 5,169,751 and 5,252,455 and Belgian Patent No. 691, triethylthiourea, N-ethyl-N'(4-methyl-2-thiazolyl) thiourea, 857. A salt of a noble metal other than gold such as plutinum, or carboxymethyltrimethylthiourea), thioamides (e.g., thio paradium or iridium which salt is described in P. Grafkides, acetamide), rhodanines (e.g., diethylrhodanine, or 5-ben Chimie et Physique Photographique, 5th Ed., Paul Momtel Zylidene-N-ethylrhodanine), phosphine Sulfides (e.g., trim (1987) and Research Disclosure, vol. 307, No. 307105 may ethylphosphine Sulfide), thiohydantoins, 4-oxo-oxazolidine be also used. 2-thions, di- or poly-sulfides (e.g., dimorpholine disulfide, 0114. The gold sensitization may be conducted alone, cysteine, or lenthionine), polythionates, or elemental Sulfur, however a combined use of the gold Sensitization and the active gelatin may be used. Thiosulfates, thioureas and chalcogen Sensitization is preferable. Specific examples of rhodanines are particularly preferable. the combination include gold-Sulfur Sensitization, gold-Se 0108. In the selenium sensitization, a labile selenium lenium Sensitization, gold-tellurium Sensitization, gold-Sul compound is used. AS the labile Selenium compound, those fur-Selenium Sensitization, gold-Sulfur-tellurium Sensitiza described in Japanese Patent Application Publication (JP-B) tion, gold-Selenium-tellurium Sensitization and gold-Sulfur Nos. 43-13489 and 44-15748, JP-A Nos. 4-25832, Selenium-tellurium Sensitization. The combination of gold 4-109340, 4-271341, 5-40324, 5-11385, 6-51415, 6-175258, Sensitization and at least Sulfur Sensitization is preferable. 6-180478, 6-208186, 6-208184, 6-317867, 7-92599, 0115 The amount of the chalcogen sensitizer used in the 7-98483 and 7-140579 can be used. invention depends on the Silver halide grains to be used or 0109 Specifically, examples thereof include colloidal chemical ageing conditions, however, may be about from metal Selenium, Selenoureas (e.g., N,N-dimethylselenourea, 10 to 10 mol, and is preferably about from 107 to 10° trifluoromethylcarbonyl-trimethylselenourea, and acetyltri mol per mol of silver halide. methylselenourea), Selenoamides (e.g., Selenoamide, and 0.116) Similarly, the amount of the gold sensitizer for use N,N-diethylphenylselenoamide), phosphine Selenides (e.g., in the invention depends on various conditions, however triphenylphosphineselenide, and pentafluorophenyl-triph may be from 107 to 10° mol for measure, and is preferably enylphosphineselenide), Selenophosphates (e.g., tri-p- from 10 to 5x10 mol per mol of silver halide. Any tolylselenophosphate, and tri-n-butylselenophosphate), Sele condition may be selected as environmental conditions for noketones (e.g., Selenobenzophenone), isoselenocyanates, chemical Sensitization of the emulsion. However, p Ag is 8 Selenocarboxylic acids, Selenoesters and diacyl Selenides. In or less, preferably 7.0 or less, more preferably 6.5 or less and addition, non-labile Selenium compounds (those described particularly 6.0 or less, however pAg is 1.5 or more, US 2005/0069827 A1 Mar. 31, 2005 preferably 2.0 or more, more preferably 2.5 or more, still 0125 8) Compound Capable of Undergoing One-elec more preferably 3 or more and particularly preferably 4.0 or tron Oxidation to Form One-electron Oxidant Capable of more. pH is from 3 to 10, and preferably from 4 to 9. Releasing One or More Electrons Temperature is from 20° C. to 95 C., and preferably from 0.126 The photothermographic material of the invention 25° C. to 80° C. preferably contains a compound capable of undergoing 0117. It is preferable to use a water-soluble thiocyanate one-electron oxidation to form a one-electron oxidant Such as , or capable of releasing one or more electrons. The compound ammonium thiocyanate at the time of chemical Sensitization, may be used alone or in combination with any of the particularly at the time of chalcogen Sensitization or gold aforementioned chemical Sensitizers to improve Sensitivity chalcogen sensitization. The amount of the thiocyanate is of the silver halide. 1x10 mol or more, preferably from 2x10 mol to 8x10 0127. The compound capable of undergoing one-electron mol, more preferably from 3x10 mol to 2x10" mol, and oxidation to form a one-electron oxidant capable of releas particularly preferably 5x10 mol to 1x10' molper mol of ing one or more electrons contained in the photosensitive silver of silver halide. material of the invention is preferably a compound Selected 0118. In the invention, reduction sensitization may be from following types 1 and 2. further conducted in combination with the chalcogen Sensi 0128 (Type 1): A compound capable of undergoing tization and gold Sensitization. In particular, a combination one-electron oxidation to form a one-electron oxi of the reduction Sensitization and the chalcogen Sensitization dant thereof which is capable of releasing further one is preferable. or more electrons through a Subsequent bond cleav 0119) As a specific compound for use in the reduction age reaction; and Sensitization method, ascorbic acid, thiourea dioxide and 0129 (Type 2): A compound capable of undergoing dimethylamineborane are preferable. In addition, Stannous one-electron oxidation to form a one-electron oxi chloride, aminoiminomethaneSulfinic acid, a hydrazine dant thereof which is capable of releasing further one derivative, a borane compound, a Silane compound or a or more electrons after going through a Subsequent polyamine compound is preferably used. A reduction Sen bond formation reaction Sitizer may be added to a System at any Step in manufac turing process of the photosensitive emulsion from crystal 0.130 First, Type 1 compound will be explained. growth to a preparation process just before coating. The 0131 Examples of Type 1 compound, which is capable of reduction Sensitization is preferably conducted by respec undergoing one-electron oxidation to form a one-electron tively maintaining pH and pAg of the emulsion at 8 or higher oxidant thereof which is capable of releasing further one and 4 or lower to age the emulsion. Further, the reduction electron through a Subsequent bond cleavage reaction, Sensitization is also preferably carried out by introducing a include those referred to as “a one-photon-two-electron Single addition portion of Silver ions into a System at the time Sensitizer” or "a deprotonation electron donating Sensitizer” of grain formation. described in JP-A Nos. 9-211769 (specific examples: com pounds PMT-1 to S-37 listed in Tables E and F on pages 28 0120) The reduction sensitization may be conducted to 32), 9-211774 and 11-95355 (specific examples: com alone or in arbitrary combination with the chalcogen Sensi pounds INV 1 to 36), 2001-500996 (specific examples: tization or gold-chalcogen Sensitization. However, when compounds 1 to 74, 80 to 87 and 92 to 122), U.S. Pat. Nos. combined with the gold-chalcogen Sensitization, these Sen 5,747.235 and 5,747.236, EP-A No. 786,692 (specific Sitizations are preferably carried out with respect to the examples: compounds INV 1 to 35), and EP-A No. 893,732 interiors of the Silver halide grains. and U.S. Pat. Nos. 6,054,260 and 5,994,051. Preferable 0121 The amount of the reduction sensitizer to be added range of these compounds is the same as that described in depends on various conditions, and is from 107 mol to 10' the above patent Specifications. mol for measure, and more preferably from 10 mol to 0.132. In addition, examples of Type 1 compound, which 5x10 mol per mol of silver halide. is capable of undergoing one-electron oxidation to form a one-electron oxidant thereof which is capable of releasing 0122) In the invention, the chemical sensitization can be further one or more electrons through a Subsequent bond conducted at any time during grain formation, or at any time cleavage reaction, include those represented by formula (1) after grain formation and before coating, and is particularly (equivalent to formula (1) described in JP-A No. 2003 preferably carried out after and during grain formation. 114487), formula (2) (equivalent to formula (2) described in Further, the Sensitization may be conducted at any time after JP-A No. 2003-114487), formula (3) (equivalent to formula deSalting, before, during, or after spectral Sensitization, or (1) described in JP-A No. 2003-114488), formula (4) just before coating. (equivalent to formula (2) described in JP-A No. 2003 0123 The silver halide emulsion for use in the invention 114488), formula (5) (equivalent to formula (3) described in may contain a thiosulfonic acid compound and the addition JP-A No. 2003-114488), formula (6) (equivalent to formula method is described in EP-A No. 293,917. (1) described in JP-A No. 2003-75950), formula (7) (equiva lent to formula (2) described in JP-A No. 2003-75950), or 0.124. The photosensitive silver halide grains in the formula (8) (equivalent to formula (1) described in Japanese invention may be preferably Subjected to chemical Sensiti Patent Application No. 2003-25886), and compounds rep Zation by at least one method of the gold Sensitization and resented by formula (9) (equivalent to formula (3) described the chalcogen Sensitization from the Viewpoint of design of in Japanese Patent Application No. 2003-33446) among a photothermographic material with high Sensitivity. those capable of causing a reaction of reaction formula (1) US 2005/0069827 A1 Mar. 31, 2005

(equivalent to reaction formula (1) described in Japanese Patent Application No. 2003-33446). Preferable range of -continued these compounds is the same as that described in the above Reaction Formula (1) patent Specifications. (M) (M)

X2 X2 e- R2 H R2 Formula (1) --- R1 R2 H r V / s R2 R2 RED-C-L Y2 Y2 Formula (2) ED Formula (9)

R2 H X2 e- R2

RED L1 HOC R2 R2 Formula (3) Y2 Z

/ Y - 0133. In the formulae, RED, and RED represent reduc R2 == L1 ing groups. R represents a nonmetallic atomic group (X1)m 1 capable of forming a ring Structure corresponding to a tetrahydro or octahydro derivative of a 5- or 6-membered Formula (4) R aromatic ring (including an aromatic heterocycle) together with a carbon atom (C) and RED. R. represents a hydrogen ED H R2 atom or a Substituent. In the case where plural RS exist in one molecule, they may be identical to or different from each other. L. represents a leaving group. ED represents an -H R.- ) vs.L1 electron-donating group. Z represents an atomic group capable of forming a 6-membered ring together with a Formula (5) R2 nitrogen atom and two carbon atoms of a benzene ring. X represents a Substituent. m represents an integer of 0 to 3. R2 N H Z represents -CRR-., -NR- or -O-. R and R independently represent a hydrogen atom or a substitu R2 R. ent. R represents a hydrogen atom, an alkyl group, an aryl R5 H group or a heterocyclic group. X represents an alkoxy R2 L1 group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, Formula (6) an alkylamino group, an arylamino group, or a hetercyclic R2 R2 amino group. L. represents a carboxyl group or a Salt thereof, or a hydrogen atom. X represents a group forming RED a 5-membered heterocycle together with C=C. Y., repre Sents a group forming a 5- or 6-membered aryl group or R2 R2 R2 heterocyclic group together with C=C. M represents a radical, a radical cation, or a cation. Formula (7) R2 R2 0134) Next, Type 2 compound will be explained. Z2 0.135 Examples of Type 2 compound, which is capable of RED undergoing one-electron oxidation to form a one-electron

R2 R2 oxidant thereof which is capable of releasing further one or R2 more electrons after going through a Subsequent bond for Formula (8) mation reaction, include compounds represented by formula X1 (10) (equivalent to formula (1) described in JP-A No. 2003-140287) and compounds formula (11) (equivalent to formula (2) described in Japanese Patent Application No. Red-H,R2 2003-33446) among those capable of causing a reaction represented by reaction formula (1) (equivalent to reaction US 2005/0069827 A1 Mar. 31, 2005 formula (1) described in Japanese Patent Application 2003 more adsorptive groups to Silver halide exist in one mol 33446). Preferable range of these compounds is identical to ecule, these groups may be identical to or different from each that described in the above patent Specifications. other. 0140 Preferable examples of the adsorptive group X-L-Y Formula (10) include mercapto-Substituted nitrogen-containing heterocy 0.136) clic groups (e.g., a 2-mercaptothiadiazole group, a 3-mer capto-1,2,4-triazole group, a 5-mercaptotetrazole group, a 2-mercapto-1,3,4-oxadiazole group, a 2-mercaptobenzox Reaction Formula (1) azole group, a 2-mercaptobenzthiazole group, and a 1,5- dimethyl-1,2,4-triazolium-3-thiolate group) and nitrogen (M) (M) containing heterocyclic groups having, as a partial Structure X2 X2 of the heterocycle, -NH-group capable of forming imino e- R2 H R2 Silver (>NAg) (Such as a benzotriazole group, a benzoimi dazole group and an indazole group). A 5-mercaptotetrazole --- group, a 3-mercapto-1,2,4-triazole group and a benzotriaz H ole group are particularly preferable, and a 3-mercapto-1,2, NS R2 R2 4-triazole group and a 5-mercaptotetrazole group are the Y2 Y2 most preferable. Formula (11) 0141 Compounds having, as the adsorptive groups and as partial Structures thereof, 2 or more mercapto groups in X2 one molecule are also particularly preferable. Here, the e- R2 mercapto group (-SH) may tautomerize, if possible, to form a thion group. Preferable examples of the adsorptive group having 2 or more mercapto groupS as partial Structures s R2 (Such as a dimercapto-Substituted nitrogen-containing het Y2 erocyclic group) include a 2,4-dimercaptopyrimidine group, a 2,4-dimercapto triazine group and a 3,5-dimercapto-1,2, 4-triazole group. 0142. In addition, quaternary Salt structure of nitrogen or 0.137 In the above formulas, X represents a reducing phosphorous is also preferably used as the adsorptive group. group to be Subjected to one-electron oxidation. Y represents Specific examples of the Structure of a quaternary Salt of a reactive group containing a carbon-carbon double bond nitrogen include ammonio groups (Such as a trialkylammo nio group, a dialkylaryl-(or heteroaryl-)ammonio group, and Site, a carbon-carbon triple bond Site, an aromatic group site an alkyldiaryl-(or heteroaryl-)ammonio group) and groups or a non-aromatic heterocycle Site of benzo condensation containing a nitrogen-containing heterocyclic group includ group capable of reacting with a one-electron oxidant gen ing a quaternary nitrogen atom. Examples of the Structure of erated by one-electron oxidation of X to from a new bond. a quaternary Salt of phosphorous include phosphonio groups L. represents a liking group liking X and Y. R. represents a (Such as a trialkylphosphonio group, a dialkylaryl-(or het hydrogen atom or a Substituent. In the case where plural RS eroaryl-) phosphonio group, an alkyldiaryl-(or heteroaryl exist in one molecule, they may be identical to or different )phosphonio group, a triaryl-(or heteroaryl-)phosphonio from each other. X represents a group forming a 5-mem group). The Structure of the quaternary Salt of nitrogen is bered heterocyclic group together with C=C. Y. represents more preferably used, and a 5-membered or 6-membered a group forming a 5- or 6-membered aryl group or a nitrogen-containing aromatic heterocyclic group containing heterocyclic group together with C=C. M represents a a quaternary nitrogen atom is still more preferably used. Particularly preferably, a pyridinio group, a quinolinio group radical, a radical cation, or a cation. or an isoquinolinio group is used. These nitrogen-containing 0138 Among compounds of Type 1 or Type 2, “those heterocyclic groups including a quaternary nitrogen atom having an adsorptive group to Silver halide in the molecule may have any Substituent. thereof or “those having the partial Structure of a spectral 0.143 Examples of the counter anion of the quaternary Sensitizing dye in the molecule thereof are preferable. AS Salt include halogen ions, carboxylate ions, Sulfonate ions, a for the adsorptive group to Silver halide, typical ones are Sulfate ion, a perchlorate ion, a carbonate ion, a nitrate ion, described in JP-A No. 2003-156823, page 16, line 1 of right BF, PF and Ph.B. When a group with a minus charge column to page 17, line 12 of right column. The partial Such as carboxylate groups exists in the molecule, an Structure of a spectral Sensitizing dye is a Structure described intramolecular Salt including the group may be formed. AS a counter-anion not existing in the molecule, a chloride ion, on page 17, line 34 of right column to page 18, line 6 of left a bromide ion or a methaneSulfonate ion is particularly column of the same patent specification. preferable. 0.139. Type 1 and Type 2 compounds are more preferably 0144 Preferable structures of compounds of Type 1 and “those having at least one adsorptive group to Silver halide Type 2 having, as the adsorptive group, the quaternary Salt in the molecule thereof.” Still more preferable compounds Structure of nitrogen or phosphorous is represented by of Types 1 and 2 are “those having 2 or more adsorptive formula (X) groups to silver halide in the molecule thereof.” When 2 or (P-Q,-)-R(-Q-S); Formula (X) US 2005/0069827 A1 Mar. 31, 2005

0145. In formula (X), P and R independently represent a ately before initiation of chemical Sensitization to immedi quaternary Salt Structure of nitrogen or phosphorous which ately after completion thereof), or before coating. The addi quaternary Salt is not the partial Structure of a Sensitizing tion timing is more preferably conducted within a period dye. Q and Q independently represent a linking group, and from the chemical Sensitization to formation of a mixture of Specifically represent a single bond, an alkylene group, an the emulsion and a non-photosensitive organic Silver Salt. arylene group, a heterocyclic group, -O-, -S-, 0147 The compound of Type 1 or Type 2 in the invention NRN-, C(=O)-, SO-, SO and is preferably added as a Solution in which the compound is -P(=O)-, or groups having a combination of these dissolved in water, a water-Soluble Solvent Such as groups. RN represents a hydrogen atom, an alkyl group, an or ethanol, or a mixed Solvent thereof. For the compound aryl group or a heterocyclic group. S is a residue formed by which is soluble in water and whose solubility increases by removing one atom from a compound of Type 1 or Type 2. increasing or decreasing pH of the resultant Solution, a Both i and j are integers of 1 or more. They are Selected Such that the sum of i and j is 2 to 6. Preferably, i is 1 to 3 and Solution in which the compound is dissolved in water and j is 1 or 2. More preferably, i is 1 or 2 and j is 1. Particularly whose pH is adjusted to be high or low may be added. preferably, i is 1 and j is 1. The compound represented by 0.148. The compound of Type 1 or Type 2 in the invention formula (X) preferably has 10 to 100 carbon atoms in total, is preferably used in an emulsion layer containing a photo more preferably 10 to 70 carbon atoms, and still more Sensitive Silver halide and a non-photosensitive organic preferably 11 to 60 carbon atoms, and particularly preferably silver salt. Further, it may be added to not only the emulsion 12 to 50 carbon atoms. layer containing the photosensitive Silver halide and the 0146 The compounds of Type 1 and Type 2 in the non-photoSensitive organic Silver Salt but also a protective invention may be used at any time during preparation of the layer and/or an intermediate layer So as to allow the com photoSensitive Silver halide emulsion or in photothermo pound to diffuse at the time of coating. Regardless of graphic material manufacturing Steps, for example, during addition timing of a Sensitizing dye, the compound of the photoSensitive Silver halide grain formation, at the time of a invention may be added to a Silver halide emulsion layer. deSalting Step, at the time of chemical Sensitization or before The content thereof is preferably 1x10 to 5x10' mol, and coating. Further, Separate portions of the compound may be more preferably 1x10 to 5x10° mol per mol of silver added two or more times in these Steps. The addition is halide. preferably conducted within a period from completion of 0149 Hereinafter, specific examples of Type 1 and Type photoSensitive Silver halide grain formation to before the 2 compounds will be shown. However, the invention is not desalting step, during the chemical sensitization (immedi limited to them.

2 N N 21 is-K \ SH N N COOH l O. N21

NHCO HS lsN ls NHSO,

4 its-kN-N > -s; N

HO

OCH NHCOCH- Cl COONa N

HOOC

Cl US 2005/0069827 A1 Mar. 31, 2005 13

-continued 5 6 SH

N OCH3 c ()

o N COOK CH 7 8 T NN N > -s; H3COC tic-Key–9N-N N N COOH

"oolN COOH I NHCO CH2C6H5 9 1O is-KN-N > -s; is-KN-N > -s; N NHCO O N NHCO CH

HOOC N COOH CH 11 N-N is- \ . > -s; N N th th

NHCO CONH NaOOC COONa

12 13

US 2005/0069827 A1 Mar. 31, 2005 15

-continued

23

is- / N OEt e

NHCO

S.

OEt

24 ses,SH ls

NHCO-(CH2)3-(CH2)2-CHCOONa N HC CH

C

25 26 is-KN-N > -s; is-KN-N ...N-N ys

HN-(CH2) n1 (CH2)2-CHCOOK N HC CH

27 28

--> N NH NHCO US 2005/0069827 A1 Mar. 31, 2005 16

-continued

29 3O N-N SH

OH is- N > -s; H N21

Sch.cook HS ls N NH N H COOLi NHCO

NHCO

32 CH CXS HS – 3– lu, COOH HO CHCOONa

HN N- NDC H HC CH

33 34 C2H5 S Et S N Et O O Cl Ox-N-KC Ox-N-g N N CHSOs Et ir (CH2)4NHCO ro

N

O OOC N COOH

35 G OOC N / " o

36 37 NHCO Nas- N N 2 CHSO HOC C. CHso US 2005/0069827 A1 Mar. 31, 2005 17

-continued

38 39

(CH)-COOK A (CH)-N NHCOCH-N COOH N1 H HC CH

CH

40 41 N-N

is- 1\ N -soCH

N A N N \ 2 N SH 42 43 N is 4 y Si(CH3)3 N

N

CONH

44 HS

N

CONH

CHN US 2005/0069827 A1 Mar. 31, 2005 18

-continued 45 NHCO

Ph N N NH

2 CHSO HOC 46 l HO COOH N21

HS ls N us -

NHCOS-1-N-N-N-1aOH 47 NHCO

y COH

0150 9) Adsorptive Redox Compound having Adsorp OXadiazole ring group, a tetrazole ring group, a purine ring tive Group and Reducing Group group, a pyridine ring group, a quinoline ring group, an isoquinoline ring group, a pyrimidine ring group and a 0151. In the invention, incorporation of an adsorptive triazine ring group. A heterocyclic group containing a qua redox compound having an adsorptive group to Silver halide ternary nitrogen atom may be usable, in which a mercapto and reducing group in the molecule thereof is preferable. Substituent can dissociate to form a meso ion. When the The adsorptive redox compound is preferably a compound mercapto group forms a Salt, the counter ion can be, for represented by formula (I). example, the cation of an alkali metal, an alkaline earth Formula (I) metal or a heavy metal (e.g., Li", Na', K", Mg", Ag", or 0152. In formula (I), A represents a group capable of Zn), an ammonium ion, a heterocyclic group containing a being adsorbed by silver halide (hereinafter, referred to as an quaternary nitrogen atom, or a phosphonium ion. adsorptive group), W represents a divalent linking group, n O155 The mercapto group serving as the adsorptive represents 0 or 1, and B represents a reducing group. group may tautomerize to a form thion group. 0153. In formula (I), the adsorptive group represented by 0156 Examples of the thion group serving as the adsorp A means a group which is directly adsorptive to a Silver tive group include a linear or cyclic thioamide group, a halide, or a group which promotes Such adsorption to the thioureido group, a thiourethan group and a dithiocarbamic Silver halide. Specific examples thereof include a mercapto acid ester group. group (or a Salt thereof), a thion group (-CO=S)-), a heterocyclic group containing at least one atom Selected O157 The heterocyclic group containing at least one atom Selected from a nitrogen atom, a Sulfur atom, a from a nitrogen atom, a Sulfur atom, a Selenium atom and a Selenium atom and a tellurium atom Serving as the adsorp tellurium atom, a Sulfide group, a disulfide group, a cationic tive group means a nitrogen-containing heterocyclic group group and an ethynyl group. having an-NH-group capable of forming an imino Silver 0154) The “mercapto group (or the salt thereof)” serving (>NAg) as a partial structure of the heterocycle, or a as the adsorptive group means not only a mercapto group (or heterocyclic group having as a partial Structure of the a Salt thereof) but also a heterocyclic, aryl or alkyl group heterocycle a “-S-” group or a "-Se-' group or a preferably Substituted by at least one mercapto group (or Salt “-Te-” group or a “=N-” group capable of coordinating thereof). Herein, the heterocyclic group at least refers to a 5 with a silver ion by a coordinate bond. The former hetero to 7-membered, monocyclic or condensed-cyclic, aromatic cyclic group can be, for example, a benzotriazole group, a or non-aromatic heterocyclic group. Examples of Such a triazole group, an indazole group, a pyrazole group, a heterocyclic group include an imidazole ring group, a thia tetrazole group, a benzimidazole group, an imidazole group Zole ring group, an oxazole ring group, a benzoimidazole or a purine group. The latter heterocyclic group can be, for ring group, a benzothiazole ring group, a benzoxazole ring example, a thiophene group, a thiazole group, an oxazole group, a triazole ring group, a thiadiazole ring group, an group, a benzothiophene group, a benzothiazole group, a US 2005/0069827 A1 Mar. 31, 2005

benzoxazole group, a thiadiazole group, an oxadiazole include a formyl group, an amino group, a group with a group, a triazine group, a Selenoazole group, a benzoSele triple bond Such as an acetylene group and a propargyl noazole group, a tellurazole group or a benzotellurazole group, a mercapto group, hydroxylamines, hydroxamic grOup. acids, hydroxyureaes, hydroxyurethans, hydroxySemicarba 0158 Examples of the Sulfido group and the disulfido Zides, reductones (including reductone derivatives), group Serving as the adsorptive group include all the groups anilines, phenols (including chroman-6-ols, 2,3-dihydroben having a partial structure of “-S-” or “-S-S-.” Zofuran-5-ols, aminophenols, Sulfonamidophenols, and 0159. The cationic group serving as the adsorptive group polyphenols Such as hydroquinones, catechols, resorcinols, means a group containing a quaternary nitrogen atom. An benzentriols, and bisphenols), or a residue formed by remov Specific example thereof is a group containing a nitrogen ing one hydrogen atom from acylhydrazines, carbamoylhy containing heterocyclic group containing an ammonio group drazines, 3-pyrazolidones and the like. They may have, of or a quaternary nitrogen atom. The nitrogen-containing course, any Substituent. heterocyclic group containing a quaternary nitrogen atom 0167. In formula (I), oxidation potential of the reducing can be, for example, a pyridinio group, a quinolinio group, group represented by B can be measured by a measuring an isoquinolinio group or an imidazolio group. method described in Akira Fujishima “DENKIKAGAKU 0160 The ethynyl group serving as the adsorptive group SOKUTEIHOU (Electrochemical Measuring method)” (pp. means a -C=CH group, whose hydrogen atom may be 150-208, GIHODO SHUPPAN Co. Ltd.) and “JIKKEN replaced by a Substituent. KAGAKU KOUZA (Experimental Chemical Course)” 4th 0.161 The adsorptive group may have any substituent. Edition, edited and written by Chemical Society of Japan (Vol. 9, pp 282 to 344, published by Maruzen Co., Ltd.). For 0162 Furthermore, specific examples of the adsorptive example, it can be measured by a rotary disc voltammetry group include those listed in JP-A No. 11-95355, pages 4 to technique. Specifically, in the method, a Sample is dissolved 7. in a solution of methanol (pH 6.5) and Britton-Robinson 0163. In formula (I), preferable examples of the adsorp buffer at a mixed ratio of 10 vol%:90 vol%, and a nitrogen tive group represented by A include mercapto-Substituted gas is introduced into a container including the resultant heterocyclic groups (e.g., a 2-mercaptothiadiazole group, a Solution for 10 minutes, and then Voltammogram of the 2-mercapto-5-aminothiadiazole group, a 3-mercapto-1,2,4 solution can be obtained at 25 C. at 1000 rotation per -triazole group, a 5-mercaptotetrazole group, a 2-mercapto minute at a Sweep Speed of 20 mV/S by using a rotary disc 1,3,4-oxadiazole group, a 2-mercaptobenzimidazole group, electrode (RDE) made of glassy carbon as a working elec a 1,5-dimethyl-1,2,4-triazolium-3-thiolate group, a 2,4- trode, a platinum wire as a counter electrode, and a Saturated dimercaptopyrimidine group, a 2,4-dimercaptotriazine calomel electrode as a reference electrode. A half-wave group, a 3,5-dimercapto-1,2,4-triazole group, and a 2.5- potential (E%) can be obtained based on the obtained dimercapto-1,3-thiazole group), and nitrogen-containing Voltammogram. heterocyclic groups having an -NH- group capable of forming an iminosilver (>NAg) as a partial structure of the 0.168. The reducing group represented by B in the inven heterocycle (e.g., a benzotriazole group, a benzimidazole tion preferably has an oxidation potential, when measured group and an indazole group). More preferably, the adsorp by the above method, in the range of about -0.3 V to about tive group is a 2-mercaptobenzimidazole group or a 3,5- 1.0 V, more preferably about -0.1 V to about 0.8 V, and dimercapto-1,2,4-triazole group. particularly preferably about 0 to about 0.7 V. 0164. In formula (I), W represents a divalent linking group. Any linking group may be uSable except as long as 0169. In formula (I), the reducing group represented by B it does not give an adverse affect to photographic properties. is preferably hydroxylamines, hydroxamic acids, hydrox For example, a divalent linking group constituted by a yureas, hydroxySemicarbazides, reductones, phenoles, acyl carbon atom, a hydrogen atom, an OXygen atom, a nitrogen hydrazines, carbamoilhydrazines, or residues formed by atom and/or a Sulfur atom can be utilized. Examples of Such removing one hydrogen atom from 3-pyrazolidons. a linking group include an alkylene group having from 1 to 20 carbon atoms (for example, a methylene group, an 0170 The compound represented by formula (I) in the ethylene group, a trimethylene group, a tetramethylene invention may be one into which a ballasting group or a group, and a hexamethylene group), an alkenylene group polymer chain customarily employed in immobile photo having from 2 to 20 carbon atoms, an alkynylene group graphic additives Such as couplers is introduced. The poly having from 2 to 20 carbon atoms, an arylene group having mer can be, for example, any of those described in JP-A No. from 6 to 20 carbon atoms (for example, a phenylene group, 1-1OO530. and a naphthylene group), a -CO-group, an -SO 0171 The compound of formula (I) in the invention may group, an-O-group, an-S-group, an-NR-group be a bis- or tris-body. The compound of formula (I) in the and combinations thereof, in which R represents a hydro invention preferably has molecular weight in the range of gen atom, an alkyl group, a heterocyclic group, or an aryl 100 and 10000, more preferably in the range of 120 and grOup. 1000, and particularly preferably in the range of 150 and 0.165. The linking group represented by W may have any 500. Substituent. 0172 Hereinafter, examples of the compound of formula 0166 In formula (I), the reducing group represented by B (I) in the invention are shown, however the invention is not is a group capable of reducing Silver ions. Examples thereof restricted to them. US 2005/0069827 A1 Mar. 31, 2005

-continued (1) (7) N Hs-( CH NH NHCONOH HN (2) N-N

HS --> SH

NH CH OCONH NHCONOH (8) (3) N-N

--> HN "se

CH N O CONH CH (9) HO NH2 (4) N-N --> HN HO

OH (5) CONH OH -O- HO OH (10) HS Ry HS -k 21 NN NX's OH H y HS (6) O CH OH . . CH, (11) HNS N HS n N Nf

SH CONH

NHCONOH US 2005/0069827 A1 Mar. 31, 2005 21

able for Spectral properties of an exposure Source, can be -continued advantageously Selected. The Silver halide photoSensitive (12) material and the photothermographic material of the inven tion are preferably Subjected to spectral Sensitization So as to have a peak of Spectral Sensitivity particularly in the range of 600 nm to 900 nm, or in the range of 300 nm to 500 nm. (13) Examples of the Sensitizing dye and the adding method include compounds described in JP-A No. 11-65021, para graphs 0103 to 0109) and those represented by formula (II) of JP-A No. 10-186572, dyes represented by formula (I) and described in paragraph O106 of JP-A No. 11-119374, dyes described in U.S. Pat. No. 5,510,236 and example 5 of 0173. In addition, specific compounds 1 to 30 and 1"-1 to U.S. Pat. No. 3,871,887, dyes disclosed in JP-A Nos. 1"-77 described in EP-A No. 1,308,776A2, pages 73 to 87, 2-961.31 and 59-48753, and those described in line 38 of can also be preferably used as the compound having the page 19 to line 35 of page 20 of EP-A No. 0,803,764, and adsorptive group and the reducing group in the invention. JP-A Nos. 2001-272747, 2001-290238 and 2002-23306. 0.174. The compound in the invention can be easily One of these Sensitizing dyes may be used alone or two or Synthesized according to a known method. more of thereof may be used. 0175 The compound of formula (I) in the invention may 0181. The addition amount of the sensitizing dye in the be used alone or two kinds or more of the compounds are invention can be a desired one in accordance with properties also preferably used. When two kinds or more of the Such as Sensitivity and fogging, but is preferably in the range compounds are used, they may be added to the same layer of 10 to 1 mol, and more preferably 10' to 10 mol per or to different layers. In this case, adding methods can be mol of silver halide in the photosensitive layer. different from each other. 0182. In the invention, a Super-sensitizer may be 0176) The compound of formula (I) in the invention is employed in order to improve Spectral Sensitizing efficiency. preferably contained in a Silver halide emulsion layer and AS the Super-Sensitizer to be used in the invention, com more preferably, it is added to a system during preparation pounds described in EP-A No. 587,338, U.S. Pat. Nos. of the emulsion. When it is added during preparation of the 3,877,943 and 4,873,184, and JP-A Nos. 5-341432, emulsion, it is possible to add it at any stage of the process. 11-109547 and 10-111543 can be used. The compound can be added, for example, during Silver halide grain formation Step, before initiation of desalting 0183) 11) Combined Use of Silver Halides Step, during the desalting Step, before initiation of chemical 0.184 As the photosensitive silver halide emulsion in the ageing Step, during the chemical ageing Step or before Silver halide photoSensitive material and the photothermo preparation of completed emulsion. Further, Separate por graphic material of the invention, only one kind thereof may tions of the compound may be added two or more times be employed, or two or more kinds thereof (e.g., those during these Steps. Use of the compound in the emulsion having different average grain sizes, different halogen com layer is preferable, but it may be added to not only the positions, different crystal habits, or different chemical Sen emulsion layer but also a protective layer or an intermediate Sitization conditions) may be employed. Use of plural kinds layer adjacent to the emulsion layer to allow the compound of photosensitive silver halides having different sensitivities to diffuse during coating. makes it possible to adjust gradation. The techniques in 0177 Preferable addition amount of the compound relation thereto are described in JP-A Nos. 57-119341, greatly depends on the adding methods and the kind of the 53-106125, 47-3929, 48-55730, 46-5187, 50-73627 and compound to be added, but generally is in the range of 57-150841. Respective emulsions preferably have different 1x10 to 1 mol, preferably 1x10 to 5x10 mol, and more sensitivities such that the difference in sensitivity is 0.2 log preferably 1x10" to 1x10' mol per mol of photosensitive E or more. silver halide. 0185. 2. Silver Halide Photosensitive Material and Pho 0178 The compound of formula (I) in the invention may tothermographic Material be added as a Solution in which the compound is dissolved 0186 The silver halide photosensitive material of the in water, a water-Soluble Solvent Such as methanol or etha invention includes a photoSensitive layer containing the nol, or a mixed Solvent thereof. At this time, it is possible to photosensitive Silver halide on at least one Side of a Support. Suitably adjust pH of the Solution by an acid or a base, and On the other hand, the photothermographic material of the the Solution may also contain a Surfactant. Further, the invention includes an image-forming layer containing the compound may be dissolved as an emulsion dispersion in an photosensitive Silver halide, a non-photoSensitive organic organic Solvent with a high boiling point ane added, or may Silver Salt, a reducing agent and a binder on at least one side be added as a Solid dispersion. of a Support. Further, each of them may preferably include 0179 10) Sensitizing Dye a Surface protective layer on the photoSensitive layer or the image-forming layer, or a back layer or back protective layer 0180. As a sensitizing dye applicable to the invention, a on the other Side of the Support. Sensitizing dye, which, when adsorbed by Silver halide grains, can spectrally Sensitize the Silver halide grains in a 0187 Configuration of each of these layers and prefer desired wavelength range and has spectral Sensitivity Suit able components thereof will be described in detail. US 2005/0069827 A1 Mar. 31, 2005 22

0188 2-1. Photosensitive Silver Halide persion' as used herein is intended to mean that the per 0189 The above-described photosensitive silver halide is centage of a value obtained by dividing the Standard devia employed. tion of the length of the Short axis or the long axis by the length of the short axis or long axis, respectively, is prefer 0190) 2-2. Organic Silver Salt ably 100% or less, more preferably 80% or less, and still 0191 The non-photosensitive organic silver salt more preferably 50% or less. As for a measuring method of employed in the invention is a Silver Salt that is relatively the form of the organic silver salt, the form can be obtained Stable with respect to light, but which forms a Silver image from a transmission electron microscopic image of an when heated to 80° C. or higher in the presence of exposed organic Silver Salt dispersion. Another method for determin photoSensitive Silver halide and a reducing agent. The ing the monodispesibility is a method involving obtaining organic Silver Salt may be any organic material containing a the Standard deviation of a Volume weight average diameter Source capable of reducing Silver ions. Such non-photosen of the organic Silver salt. The percentage (coefficient of sitive organic silver salts are described in JP-A No. variation) of the value obtained by dividing the standard 10-62899, paragraphs 0048 to 0049), EP-A No. deviation by the Volume weight average diameter is prefer 0803764A1 page 18, line 24 to page 19, line 37, EP-A No. ably 100% or less, more preferably 80% or less, and still 0962812, JP-A Nos. 11-349591, 2000-7683 and 2000 72711. Silver salts of organic acids, particularly silver salts more preferably 50% or less. As for a measurement method, of long-chain aliphatic carboxylic acids (having 10 to 30 for example, laser light is irradiated on the organic Silver Salt carbon atoms, preferably having 15 to 28 carbon atoms) are dispersed in a liquid to allow the light to be Scattered and, preferable. Preferable examples of the organic silver salt then, an autocorrelation function of fluctuation of the result include , Silver arachidate, Silver Stearate, ant Scattered light against time is obtained to measure a grain Silver oleate, Silver laurate, Silver caproate, Silver myristate, Size (volume weight average diameter) and, thereafter, the Silver palmitate and mixtures thereof. In the invention, monodispesibility can be obtained from the thus-measured among these organic Silver Salts, use of an organic acid Silver grain size. salt containing 50 mol % to 100 mol % of silver behenate is 0.197 As a method for manufacturing and dispersing the preferable. In particular, the content of Silver behenate is organic Silver Salt for use in the invention, a known method preferably 75 mol % to 98 mol%. may be applied. For example, JP-A No. 10-62899, EP-A 0.192 The form of the organic silver salt that can be used Nos. 0803763A1 and O962812A1, JP-A Nos. 11-349591, in the invention is not particularly limited. Preferable 2000-7683, 2000-72711, 2001-163827, 2001-163889, 2001 examples of the form are needle-like, bar-shaped, tabular 163890, 11-203413, 2001-188313, 2001-83652, 2002-6442, and flaky forms. and 2002-31870, Japanese Patent Application No. 2000 0193 The organic silver salt having a flaky form is 214155 and JP-A2000-191226 can be referred to. preferable in the invention. In the Specification, the flaky organic Silver Salt is defined as follows. The organic Silver 0198 2-3. Blending of Silver Halide with Organic Silver Salt is observed by an electron microscope, the form of a Salt organic Silver Salt grain is regarded as a rectangular paral lelopiped. Then, given that the length of the shortest edge of 0199. It is particularly preferable that the photosensitive the rectangular parallelopiped, the length of the next shortest Silver halide grains in the invention are formed in the edge and the length of the longest edge are respectively absence of the non-photoSensitive organic Silver Salt and defined as “a, b and c' (c may be equal to b), X is calculated chemically Sensitized. This is because Sufficient Sensitivity according to the following expression by using lengths a and may not be obtained by a method for forming silver halide b. in which a halogenating agent is added to the organic Silver Salt. 0194 In this manner, the values X of around 200 grains 0200. As a method for blending the silver halide and the are obtained and the average of the obtained values is organic Silver Salt, there are a method in which the photo defined as X (average). Grains Satisfying the following Sensitive Silver halide and the organic Silver Salt which have relation: 1.52X (average) are determined as flaky grains. been Separately prepared are blended by, for example, a Preferably, flaky grains Satisfying the following relation: high-speed Stirrer, a ball mill, a Sand mill, a colloid mill, a 1.52X (average)230 are preferable and flaky grains satis Vibration mill or a homogenizer, a method in which the fying the following relation: 1.52X (average)215 are more photosensitive Silver halide which has been previously pre preferable. In this connection, needle-like grains Satisfy the pared is mixed at an appropriate timing in the process of following relation: 1sX (average)<1.5. preparing the organic Silver Salt to prepare the organic Silver 0.195. In the flaky grains, “a” can be regarded as the salt. Any of these methods can favorably obtain an effect of thickness of tabular grains having, as the principal plane, a the invention. plane with edges b and C. The average of “a” is preferably 0201 In the invention, it is possible to manufacture a in the range of 0.01 um to 0.3 um, and more preferably 0.1 photosensitive material by blending the aqueous dispersion um to 0.23 um. The average of (c/b) S is preferably in the of the organic Silver Salt and the aqueous dispersion of the range of 1 to 6, more preferably in the range of 1 to 4, Still photosensitive silver salt. Blending of two kinds or more of more preferably in the range of 1 to 3, and particularly the aqueous dispersions of the organic Silver Salts and two preferably in the range of 1 to 2. kinds or more of the aqueous dispersions of the photosen 0196. The size distribution of the organic silver salt Sitive Silver Salts is preferably used for the purpose of grains is preferably monodispersion. The term "monodis controlling photographic properties. US 2005/0069827 A1 Mar. 31, 2005 23

0202 Blending of Silver Halide to Coating Liquid taining at least one nitrogen atom is preferable. When the 0203 The silver halide in the invention is added to a compound does not have a mercapto group, a Sulfide group coating liquid of an image-forming layer during a period or a thion group as a Substituent, the nitrogen-containing 5 Starting from 180 minutes before coating and ending imme to 7-membered heterocycle may be either saturated or diately before coating, preferably during a period Starting unsaturated, and have another Substituent. Further, Substitu from 60 minutes to 10 seconds before coating. A blending ents of the heterocycle may bond to each other to form a method and blending conditions are not particularly limited ring. as far as the effect of the invention Sufficiently arises. Specific examples of the blending method include a method 0211 Typical examples of a 5- to 7-membered heterocy of blending in a tank Such that an average residence period, clic compound include pyrrole, pyridine, oxazole, isOOX calculated from an adding flow rate and a Supplying flow azole, thiazole, isothiazole, imidazole, pyrazole, pyrazine, rate to a coater, is allowed to be within a predetermined pyrimidine, pyridazine, indole, isoindole, indolizine, quino duration, and a method using a Static mixer described, for line, isoquinoline, benzoimidazole, 1H-imidazole, quinoxa example, in N. Harnby, M. F. Edwards & A. W. Nienow, line, quinazoline, cinnoline, phthalazine, naphthylizine, (translated by Koji Takahashi), “Liquid Mixing Technology” purine, pteridine, carbazole, acridine, phenanthridine, Chap. 8, The Nikkan Kogyo Shimbun, Ltd. (1989). phenanthroline, phenazine, phenoxazine, phenothiazine, 0204. The organic silver salt in the invention can be used benzothiazole, benzooxazole, benzoimidazole, 1,2,4-triaz in any amount, but the amount is preferably in the range of ine, 1,3,5-triazine, pyrrolidine, imidazolidine, pyrazolidine, 0.1 g/m· to 5 g/m·, more preferably 1 g/m to 3 g/ml, and piperidine, piperazine, morpholine, indoline and isolindoline. particularly preferably 1.2 g/m to 2.5 g/m in terms of silver Pyridine, imidazole, pyrazole, pyrazine, pyrimidine, amount. pyridazine, indole, isolindole, indolizine, quinoline, iso 0205 2-4. Compound which Substantially Decreases quinoline, benzoimidazole, 1H-imidazole, quinoxaline, Visible Light Absorption Derived from Photosensitive Sil quinazoline, cinnoline, phthalazine, 1,8-naphthylizine, 1,10 ver Halide after Thermal Development phenanthroline, benzoimidazole, benzotriazole, 1,2,4-triaz 0206. In the invention, the photosensitive material and ine and 1,3,5-triazine are more preferable. Pyridine, imida the thermographic material preferably contains a compound Zole, pyrazine, pyrimidine, pyridazine, phthalazine, triazine, that Substantially decreases visible light absorption derived 1,8-naphthylizine and 1,10-phenanthroline are still more from the photosensitive silver halide after thermal develop preferable. ment compared with visible light absorption before thermal development. AS the compound which Substantially 0212. These rings may have a substituent. Any substitu decreases visible light absorption derived from the photo ent may be used as far as it does not give an adverse affect sensitive silver halide after thermal development, a silver to photographic properties. Preferable examples include a iodide complex-forming agent is particularly preferably halogen atom (a fluorine atom, a chlorine atom, a bromine used. atom or an iodine atom), an alkyl group (a linear-, branched-, 0207 Silver Iodide Complex-Forming Agent cyclic-alkyl group containing a bicycloalkyl group or an 0208. The silver iodide complex-forming agent in the active methine group), an alkenyl group, an alkynyl group, invention can contribute to Lewis acid-base reaction in an aryl group, a heterocyclic group (no restriction on a which at least one of a nitrogen atom and a Sulfur atom in Substituting site), an acyl group, an alkoxycarbonyl group, the compound donates an electron to Silver ions as a coor an aryloxycarbonyl group, a heterocyclicoxycarbonyl group, dinating atom (electron donor: Lewis base). Stability of the a carbamoyl group, a N-acylcarbamoyl group, a N-Sulfo complex is defined by a Sequential Stability constant or an nylcarbamoyl group, a N-carbamoylcarbamoyl group, a entire Stability constant. The Stability depends on a combi N-Sulfamoylcarbamoyl group, a carbazoyl group, a carboxyl nation of three members, i.e., a Silver ion, an iodide ion and the Silver complex-forming agent. As a general guide, it is group and Salts thereof, an oxalyl group, an oxamoyl group, possible to obtain a large Stability constant by means Such as a cyano group, a carbonimidoyl group, a formyl group, a a chelating effect due to formation of an intramolecular hydroxyl group, an alkoxy group (including a group repeat chelate ring or increase of an acid-base dissociation constant edly containing an ethyleneoxe group unit or a propyleneoxy of a ligand. group unit), an aryloxy group, a heterocyclicoxy group, an 0209 Ultraviolet-visible absorption spectrum of the pho acyloxy group, a (alkoxy- or aryloxy-)carbonyloxy group, a toSensitive Silver halide can be measured by a transmission carbamoyloxy group, a Sulfonyloxy group, an amino group, method or a reflection method. In the case where an absorp an (alkyl-, aryl- or heterocyclic-) amino group, an acylamino tion originated from other compound added to the photo group, a Sulfonamido group, an ureide group, a tioureide thermographic material overlaps the absorption of the pho group, an imido group, a (alkoxy- or aryloxy-)carbony tosensitive silver halide, the ultraviolet-visible absorption lamino group, a Sulfamoylamino group, a Semicarbazide spectrum of the photosensitive silver halide can be observed group, an ammonio group, an OXamoylamino group, a by employing a means Such as differential spectrum, or N-(alkyl- or aryl-)sulfonylureido group, a N-acylureide removal of the other compound by a Solvent, or the com group, a N-acylsulfamoylamino group, a nitro group, a bination thereof. heterocyclic group containing a quaternary nitrogen atom 0210. As the silver iodide complex-forming agent in the (e.g., a pyridinio group, an imidazolio group, a quinolinio invention, a 5- to 7-membered heterocyclic compound con group, and an isoquinolinio group), an isocyano group, an US 2005/0069827 A1 Mar. 31, 2005 24 imino group, a (alkyl- or aryl-)sulfonyl group, a (alkyl- or gen-containing 5- to 7-membered heterocycle type Silver aryl-) Sulfinyl group, a Sulfo group and Salts thereof, a iodide complex-forming agent. Sulfamoyl group, a N-acylsulfamoyl group, a N-Sulfonyl Sulfamoyl group and Salts thereof, a phosphino group, a 0219. Further, a compound represented by the following phosphinyl group, a phosphinyloxy group, a phosphiny formula (3) is also preferably utilized. lamino group and a silyl group. Here, the active methine group means a methine group having, as Substituents, two electron-attractive groups. The electron-attractive group Formula (3) means an acyl group, an alkoxycarbonyl group, an aryloxy carbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a Sulfamoyl group, a trifluoromethyl group, a cyano group, a nitro group or a carbonimidoyl group. The two electron-attractive groups may bond to each other to form a ring Structure. The Salt means the cation of an alkali metal, an alkali earth metal or a heavy metal, or an organic cation Such as an ammonium ion or a phosphonium 0220. In formula (3), R to R independently represent ion. These substituents may further have any of these a hydrogen atom or a Substituent. Examples of the Substitu Substituents. ent represented by R to R include those explained as the Substituent of the nitrogen-containing 5- to 7-membered 0213 Any of these heterocycles and other ring may form heterocycle type Silver iodide complex-forming agent. a condensed ring. When the Substituent is an anion group When the compound represented by formula (3) has at least (e.g., -CO2 group, -SO-group, -ST-group), the one Substituent, the compound preferably has the at least one nitrogen-containing heterocycle of the invention may have a substituent at at least one site of R, R and R. R. to R cation (e.g., pyridinium, or 1,2,4-triazolium) to form an may bond to each other to form a Saturated or unsaturated intramolecular Salt. ring. Preferably, each of R to R is a halogen atom, an 0214) When the heterocyclic compound is a derivative of alkyl group, an aryl group, a carbamoyl group, a hydroxyl pyridine, pyrazine, pyrimidine, pyridazine, phthalazine, tri group, an alkoxy group, an aryloxy group, a carbamoyloxy azine, naphthylizine or phenanthroline, it is more preferable group, an amino group, an acylamino group, an ureido that an acid dissociation constant (pKa) of the conjugate acid group, or a (alkoxy- or aryloxy-) carbonylamino group. of the nitrogen-containing heterocycle moiety in acid dis 0221 For the compound represented by formula (3), an Sociation equilibrium of the compound is 3 to 8 in a mixed acid dissociation constant (pKa) of the conjugate acid of the solution of tetrahydrofuran/water (3/2) at 25 C. Further pyridine ring moiety is preferably 3 to 8, and more prefer more preferably, pKa is 4 to 7. ably 4 to 7 in a mixed solution of tetrahydrofuran/water (3/2) at 25° C. 0215. As such a heterocyclic compound, a derivative of pyridine, pyridazine or phthalazine is preferable, and a 0222 Further, a compound represented by the following derivative of pyridine or phthalazine is more preferable. formula (4) is also preferable. 0216. When the heterocyclic compound includes a mer capto group, a Sulfide group or a thion group as a Substituent, Formula (4) the compound is preferably a derivative of pyridine, thiaz R41 ole, isothiazole, oxazole, isooxazole, imidazole, pyrazole, R42 pyrazine, pyrimidine, pyridazine, triazine, triazole, thiazole or oxadiazole, particularly preferably a derivative of thiaz rN ole, imidazole, pyrazole, pyrazine, pyrimidine, pyridazine, R43 2 triazine or triazole. 0217 For example, a compound represented by the fol R44 lowing formula (1) or (2) may be utilized as the silver iodide complex-forming agent. 0223) In formula (4), R' to R' independently represent a hydrogen atom or a substituent. At least two of R' to R' may bond to each other to form a Saturated or unsaturated 11 12 Formula (1) R11-S-R ring. Examples of the substituent represented by R' to R" Formula (2) include those explained as the Substituent of the nitrogen S containing 5- to 7-membered heterocycle type Silver iodide complex-forming agent. These groups preferably represent 1. R22 an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a hydroxyl group, an alkoxy group, an aryloxy group or a heterocyclicoxy group, and may form a phthalazine ring 0218. In formula (1), each of R'' and R' represents a due to a benzo-condensed ring. When a carbon atom ada hydrogen atom or a substituent. In formula (2), each of R' cent to a nitrogen atom of the compound represented by and Rif represents a hydrogen atom or a substituent. How formula (4) has a hydroxyl group, equilibrium exists ever, both of R'' and R', or both of R and R' cannot be between the compound and pyridaZinon. hydrogen atoms at the same time. Examples of the Substitu 0224 Preferably, the compound represented by formula ent include those explained as the Substituent of the nitro (4) forms a phthalazine ring represented by the following US 2005/0069827 A1 Mar. 31, 2005 25 formula (5). Preferably, the phthalazine ring further has at least one substituent. Examples of R to R in formula (5) include those explained as the Substituent of the nitrogen Formula (8) containing 5- to 7-membered heterocycle type Silver iodide S complex-forming agent. AS the preferable Substituent, an R ls R85 alkyl group, an alkenyl group, an alkynyl group, an aryl n Y group, a hydroxyl group, an alkoxy group or an aryloxy group can be used. The Substituent is preferably an alkyl group, an alkenyl group, an aryl group, an alkoxy group or an aryloxy group, and more preferably an alkyl group, an 0230. In formula (8), R to R' independently represent alkoxy group or an aryloxy group. a hydrogen atom or a Substituent. Examples of the Substitu ents represented by R to R' include an alkyl group (including a cycloalkyl group), an alkenyl group (including Formula (5) R56 R51 a cycloalkenyl group), an alkynyl group, an aryl group, a heterocyclic group, an acyl group, an aryloxycarbonyl RSS group, an alkoxycarbonyl group, a carbamoyl group and an imido group. r N R54 2 0231. The silver iodide complex-forming agents is more preferably a compound represented by formula (3), (4), (5), R53 R52 (6) or (7), and still more preferably a compound represented by formula (3) or (5). 0225. Further, a compound represented by the following 0232 Hereinafter, preferable examples of the silver formula (6) is also preferable. iodide complex-forming agent in the invention are shown. However, the invention is not restricted to them. Formula (6)

(1)

(2)

0226. In formula (6), R to R' independently represent a hydrogen atom or a Substituent. Examples of the Substitu ent represented by R' include those explained as the sub (3) Stituent of the nitrogen-containing 5- to 7-membered het erocycle type Silver iodide complex-forming agent. 0227. A compound represented by the following formula (7) is preferably used. (4) R7'-S-(L)-S-R' Formula (7) 0228. In formula (7), R7 and R' independently repre Sent a hydrogen atom or a Substituent. L represents a bivalent linking group. n represents 0 or 1. Examples of the Substitu (5) ents represented by R'' and R' include an alkyl group (including a cycloalkyl group), an alkenyl group (including (6) a cycloalkenyl group), an alkynyl group, an aryl group, a (7) heterocyclic group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an HC C CH imido group and a composite Substituent containing Some of n1n 1 these groups. The bivalent linking group represented by L is preferably a linking group having 1 to 6 atoms, and more preferably 1 to 3 atoms. The bivalent linking group may (8) have a Substituent. 0229. Further, a compound represented by the following formula (8) is also preferably used. US 2005/0069827 A1 Mar. 31, 2005 26

-continued -continued

(17) (9) N n 2 CH co-( )—a (18) (10) () i| s 2N (19) HO NN (11) l n sy (20) / \ ZY S (21) NN (12) l (22) lNN (13) (23) NN - (24) (14) Cl s Cl 2N (25) r ON 2N (15) (26) r HN 2N (16) (27) SH N1 N US 2005/0069827 A1 Mar. 31, 2005 27

-continued -continued (28) (38) SH N-N NN N1 N ( N ) SH

HS us N2 SH (29) SH (39) N N1 N n l 2 CHCOOH C4H9 HS N 21 CON1 CH C4Ho (30) (40) HC N N VG) N-N s r HC - N >eS 21 ini-tch". Ni N O O C4H9 (41) (31) N HC N V () N-N - >e 2 Nigelo HC N S O (42) NHCOOCHs CH2CH2 (32) HS1 NHC10H1 HC V () N-N 0233. When the silver iodide complex-forming agent in -k > G the invention functions as a conventionally known color HC N S toning agent, it can Serve the color-toning agent. The Silver iodide complex-forming agent in the invention can be used in combination with a color-toning agent. Further, two or more kinds of the Silver iodide complex-forming agents may be used. (33) 0234. The silver iodide complex-forming agent in the S invention preferably exists in the film Such that the agent Separates from the photosensitive Silver halide. Such is HC YN -l N1 CH realized, for example, by allowing the agent to exist in the form of Solid. It is also preferable that the agent is contained (34) in a layer adjacent to a layer including the photoSensitive S Silver halide. The melting point of the agent is preferably adjusted to a value within a Suitable range So that the Silver iodide complex-forming agent in the invention melts when HN NHC12H25 heated to a thermal development temperature. (35) S S 0235. In the invention, the ratio of the absorption inten sity of the ultraviolet-visible absorption spectrum of the HC YN ls N ls N1 CH photosensitive silver halide after thermal development to H that before thermal development is preferably 80% or less, CH CH more preferably 40% or less, and still more preferably 10% (36) or less. 0236. The silver iodide complex-forming agent in the (37) invention may be incorporated in a coating liquid and in turn the photoSensitive material in any form Such as a Solution, an emulsified dispersion or a Solid fine grain dispersion. X-) 0237 An example of s a well known method for emul Sion dispersion can be a method in which a material is US 2005/0069827 A1 Mar. 31, 2005 28 dissolved in an oil Such as dibutyl phthalate, tricresyl group or -CHR'-group. R' represents a hydrogenatom phosphate, glyceryl triacetate or diethyl phtalate or an aux or an alkyl group having 1 to 20 carbon atoms. X" and X' iliary Solvent Such as ethyl or cyclohexanone to independently represent a hydrogen atom or a group capable mechanically produce an emulsified dispersion. of bonding to a benzene ring. 0238 An example of a method for dispersing solid 0246. Each substituent will be described in detail. microparticles can be a method in which powder of the Silver iodide complex-forming agent in the invention is dispersed O247 1) R'' and R' in a Suitable Solvent Such as water by using a ball mill, a 0248) R'' and R' independently represent a substituted colloid mill, a vibrational ball mill, a Sand mill, a jet mill, a or unsubstituted alkyl group having 1 to 20 carbon atoms. roller mill or an ultrasonic wave to produce a Solid disper The Substituent of the Substituted alkyl group is not particu Sion. In this method, a protective colloid (Such as polyvinyl larly limited. For example, typical examples thereof include alcohol) and/or a Surfactant (anionic Surfactant Such as an aryl group, a hydroxyl group, an alkoxy group, an aryloxy Sodium triisopropylnaphthalenesulfonate (mixture of the group, an alkylthio group, an arylthio group, an acylamino Sulfonates having three isopropyl groups at different sites)) group, a Sulfonamido group, a Sulfonyl group, a phosphoryl may be employed. In the above-mentioned mill, beads made group, an acyl group, a carbamoyl group, an ester group and of Zirconia are commonly used as a dispersion medium, and therefore Zr derived from these beads sometimes contami a halogen atom. nates the dispersion. The amount of the contaminant 0249 2) R' and R'' and X and X" depends on dispersion conditions, but is usually in the range of 1 ppm to 1000 ppm. When the amount of Zr in the 0250) R' and R' independently represent a hydrogen photoSensitive material is 0.5 mg or leSS per g of Silver, the atom or a group capable of bonding to a benzene ring. photoSensitive material is not problematic in practical use. 0251) X" and X" independently represent a hydrogen 0239). An aqueous dispersion preferably contains an anti atom or a group capable of bonding to a benzene ring. Septic agent (e.g., benzoisothiazolinon Sodium salt). Typical examples of the group capable of bonding to a benzene ring include an alkyl group, an aryl group, a 0240 The silver iodide complex-forming agent in the halogen atom, an alkoxy group and an acylamino group. invention is preferably used as a Solid dispersion. 0241 The silver iodide complex-forming agent in the 0252 3) L invention is preferably used in the range of 1 mol % to 5000 0253 L represents -S-group or -CHR" group. R' mol %, more preferably in the range of 10 mol % to 1000 represents a hydrogen atom or a Substituted or unsubstituted mol %, and still more preferably in the range of 50 mol % alkyl group having 1 to 20 carbon atoms. to 300 mol % with respect to photosensitive silver halide. 0254 Specific examples of the unsubstituted alkyl group 0242 2-5. Reducing Agent represented by R' include a methyl group, an ethyl group, 0243 The photothermographic material of the invention a propyl group, a butyl group, a heptyl group, an undecyl includes a reducing agent for the organic Silver Salt. The group, an isopropyl group, a 1-ethylpentyl group and a reducing agent may be any material (preferably an organic 2,4,4-trimethylpentyl group. material) capable of reducing Silver ions to metal silver. 0255 Examples of the Substituent of the substituted alkyl Examples of the reducing agent are described in JP-A No. group are similar to those described in the explanations of 11-65021, paragraphs 0043 to 0045 and EP-B No. R', and include a halogen atom, an alkoxy group, an 0803764, page 7, line 34 to page 18, line 12. alkylthio group, an aryloxy group, an arylthio group, an 0244. The reducing agent for use in the invention is acylamino group, a Sulfonamido group, a Sulfonyl group, a preferably a So-called hindered phenol reducing agent hav phosphoryl group, an oxycarbonyl group, a carbamoyl group ing a Substituent at the ortho position with respect to a and a Sulfamoil group. phenolic hydroxyl group or a bisphenol reducing agent. In particular, a compound represented by the following formula 0256 4) Typical Substituents (R) is preferable. 0257) Typical examples of R'' and R'' are secondary or tertiary alkyl groups having 3 to 15 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl Formula (R) group, a t-butyl group, a t-amyl, a t-Octyl group, a cyclo OH OH hexyl group, a cyclopentyl group, a 1-methylcyclohexyl group and a 1-methylcyclopropyl group. R'' and R' more independently preferably represent a tertiary alkyl group having 4 to 12 carbon atoms, Still more preferably represent a t-butyl group, a t-amyl group or a 1-methylcyclohexyl group, and most preferably represent a t-butyl group. 0258 Typical examples of R'' and R'' are alkyl groups having 1 to 20 carbon atoms. Specific examples thereof 0245. In formula (R), R'' and R' independently repre include a methyl group, an ethyl group, a propyl group, a sent an alkyl group having 1 to 20 carbon atoms. R'' and butyl group, an isopropyl group, a t-butyl group, a t-amyl R"f Independently represent a hydrogen atom or a substitu group, a cyclohexyl group, a 1-methylcyclohexyl group, a ent capable of bonding to a benzene ring. L represents -S- benzyl group, a methoxymethyl group and a methoxyethyl US 2005/0069827 A1 Mar. 31, 2005 29 group. R'' and R' independently more preferably represent a methyl group, an ethyl group, a propyl group, an isopropyl -continued group or a t-butyl group. (R-2) 0259 Each of X" and X" is preferably a hydrogen atom, OH OH a halogen atom or an alkyl group, and more preferably a hydrogen atom.

0260 L isS preferablyCCOTW a -CHR" -- groupSOU). 0261) R' is preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. The alkyl group is preferably a methyl group, an ethyl group, a propyl group, an isopropyl (R-3) group or a 2,4,4-trimethylpentyl group, and particularly OH OH preferably a hydrogen atom, a methyl group, a propyl group or an isopropyl group. 0262. When R' is a hydrogen atom, each of R'' and R' is preferably an alkyl group having 2 to 5 carbon atoms, more preferably an ethyl group or a propyl group, and most preferably an ethyl group. (R-4) 0263. When R' is a primary or secondary alkyl group having 1 to 8 carbon atoms, preferably R'' and R'' are OH methyl groups. The primary or Secondary alkyl group having 1 to 8 carbon atoms represented by R' is more preferably a methyl group, an ethyl group, a propyl group or an isopropyl group, and still more preferably a methyl group, O O an ethyl group or propyl group. 0264. When each of R'', R, R and R' is a methyl (R-5) group, R is preferably a secondary alkyl group. In this OH case, the secondary alkyl group represented by R' is pref erably an isopropyl group, an isobutyl group or a 1-ethyl pentyl group, and more preferably an isopropyl group. O O 0265. The reducing agent differs in various thermal development properties according to combinations of R' (R-6) and R', and R'' and R', and R". These thermal devel OH OH opment properties can be adjusted by using two or more kinds of the reducing agents in various mixing ratioS. Therefore, use of two or more kinds of reducing agents is preferable for Some purposes. O O 0266 Specific examples of the compound represented by (R-7) formula (R) in the invention. However, the invention is not OH OH restricted to them. (R-1) roror OH OH OH OH US 2005/0069827 A1 Mar. 31, 2005 30

-continued -continued (R-9) (R-16) O OH OH gro" O O (R-10) (R-17) OH OH it's O O (R-11)

(R-18) CH

OH OH

(R-12)

(R-19)

OH

(R-13)

(R-20) COCH NH OH (R-14)

(R-15) (R-21)

CHOCH CHOCH US 2005/0069827 A1 Mar. 31, 2005 31

-continued -continued (R-22) (R-29) OH Ó O o CH-CHCOOCH17 CH2 CH2

(R-30)

(R-23) OH OH

rootsCHOCH CHOCH (R-24) OH OH (R-31)

r (R-25) OH OH OH o -d O O (R-32)

(R-26) H

C.O (R-33)

(R-27) CH7 OH OH

ord (R-34) (R-28) ''OH OH O US 2005/0069827 A1 Mar. 31, 2005 32

of the Support on which Surface the image-forming layer is -continued formed is preferably 5 mol % to 50 mol %, and more (R-35) preferably 10 mol % to 40 mol % per mol of silver. OH O 0269. The reducing agent in the invention can be con tained in the image-forming layer containing the organic Silver Salt and the photoSensitive Silver halide and a layer adjacent to the image-forming layer, but is more preferably incorporated in the image-forming layer. 0270. The reducing agent in the invention may be incor (R-36) porated in a coating liquid and in turn the photosensitive material as any form Such as a Solution, an emulsified dispersion and a Solid microparticle dispersion.

OH O 0271 An example of a well known emulsion dispersion method is a method in which the reducing agent is dissolved in an oil Such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phtalate, or an auxiliary Solvent Such as ethyl acetate or cyclohexanone, and then mechani cally emulsion-dispersed. 0272 An example of a solid microparticle dispersion (R-37) method is a method in which the reducing agent is dispersed in a Suitable Solvent Such as water by using a ball mill, a colloid mill, a vibrational ball mill, a Sand mill, a jet mill, a OH OH roller mill or an ultrasonic wave to produce a Solid disper Sion. It is preferable that the sand mill is used in the method. In this method, a protective colloid (Such as polyvinyl alcohol) or a Surfactant (anionic Surfactant Such as Sodium triisopropylnaphthalenesulfonate (mixture of the Sulfonates having three isopropyl groups at different Sites)) may be employed. An aqueous dispersion may contain an antiseptic (R-38) agent (e.g., benzoisothiazolinon Sodium salt). 0273. The solid particle dispersion method of the reduc ing agent is particularly preferable. The reducing agent is preferably used as a Solid dispersion including micropar ticles which has an average particle size in the range of 0.01 OH OH tim to 10 um, preferably in the range of 0.05 um to 5 Lim, and more preferably in the range of 0.1 um to 1 um and added to a System. In the invention, it is preferable that other Solid dispersions include particles having a size within the above range. 0274) 2-6. Development Accelerator (R-39) 0275. The photothermographic material of the invention preferably contains a development accelerator Such as Sul fonamidophenol compounds represented by formula (A) described in JP-A Nos. 2000-267222 and 2000-330234, hindered phenol compounds represented by formula (II) OH OH described in JP-A No. 2001-92075, compounds represented by formula (I) described in JP-A No. 10–32895 and 11-15116, hydrazine compounds represented by formula (I) described in JP-A No. 2002-278017, and phenol and naph thol compounds represented by formula (2) described in JP-A No. 2001-264929. The content of the development accelerator is 0.1 mol % to 20 mol %, preferably 0.5 mol % to 10 mol %, and more preferably 1 mol % to 5 mol % with respect to the reducing agent. The development accelerator 0267 The reducing agent is particularly preferably any of can be introduced into the photothermographic material in compounds represented by (R-1) to (R-20). the same manner as introduction of the reducing agent, and is preferably contained as a Solid dispersion or an emulsified 0268. The amount of the reducing agent added in the dispersion. When the development accelerator is used as an invention is preferably 0.01 g/m to 5.0 g/m, and more emulsified dispersion, the development accelerator is pref preferably 0.1 g/m to 3.0 g/ml. Further, the content of the erably used as an emulsified dispersion octained including reducing agent contained in a layer or layerS on one Surface the development accelerator, a high-boiling Solvent which is US 2005/0069827 A1 Mar. 31, 2005 33

Solid at ordinary temperature, and a low-boiling auxiliary Solvent, or as a So-called oilleSS emulsified dispersion with -continued out a high-boiling Solvent. (A-7) 0276. In the invention, the development accelerator is OH particularly preferably a hydrazine compound represented by formula (1) described in JP-A No. 2002-278017 and a phenol or naphthol compound represented by formula (2) described in JP-A No. 2001-264929. 0277 Typical examples of the development accelerator OCH2CH2 -(O) in the invention are shown below. However, the invention is not restricted to them. (A-8) C OH (A-1) CONH NHNHCONH Ores, (A-2) (A-9) C C5H11(t) OH

C NHCO NHNHCONHCHCHCHO Csh11(t)

CHs C Ores, C (A-3) (A-10)

NC NHNHCONH C OH CONHCH2CH2CH2O CsH11(t)

NC SOCH C (A-4) CsH11(t) Cl O

HO No-O- NHCOC Ho(t) (A-11)

Cl NC NHNHCONH C (A-5)

N e S X-NHNHCONHCH-CHCH-O C5H11(t) NC SOCH3 C N (A-12) C5H11(t) C OH (A-6) inco-O) CONH C

N SOCH3 ki-O) US 2005/0069827 A1 Mar. 31, 2005 34

aryl group, an alkoxy group, an amino group, an acyl group, -continued an acylamino group, an alkylthio group, an arylthio group, (A-13) a Sulfonamide group, an acyloxy group, an oxycarbonyl OH group, a carbamoyl group, a Sulfamoyl group, a Sulfonyl group or a phosphoryl group. The Substituent is preferably an alkyl group or an aryl group, Such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a t-octyl group, a phenyl group, a 4-alkoxyphenyl group or a 4-acy kitch-O) loxyphenyl group. (A-14) 0284 Specific examples of the alkyl group represented OH by R to R' include a methyl group, an ethyl group, abutyl group, an octyl group, a dodecyl group, an isopropyl group, a t-butyl group, a t-amyl group, a t-octyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a benzyl group, a phen ethyl group and a 2-phenoxypropyl group.

Cl 0285) Examples of the aryl group include a phenyl group, a cresyl group, a Xylyl group, a naphthyl group, a 4-t- butylphenyl group, a 4-t-octylphenyl group, a 4-anisidyl 0278 2-7. Hydrogen Bonding Compound group and a 3,5-dichlorophenyl group. 0279. In the invention, the photosensitive material and 0286 Examples of the alkoxy group include a methoxy the thermographic material preferably contain a non-reduc group, an ethoxy group, a butoxy group, an octyloxy group, ing compound having a group capable of forming a hydro a 2-ethylhexyloxy group, a 3.5,5-trimethylhexyloxy group, a gen bond with the aromatic hydroxyl group (-OH) of the dodecyloxy group, a cyclohexyloxy group, a 4-methylcy reducing agent, or, when the reducing agent also has an clohexyloxy group and a benzyloxy group. amino group, the amino group. 0280 The group capable of forming a hydrogen bond can 0287 Examples of the aryloxy group include a phenoxy be a phosphoryl group, a Sulfoxide group, a Sulfonyl group, group, a creSyloxy group, an isopropylphenoxy group, a a carbonyl group, an amide group, an ester group, an 4-t-butylphenoxy group, a naphthoxy group and a bipheny urethane group, an ureido group, a tertiary amino group, or loxy group. a nitrogen-containing aromatic group. Compounds having a 0288 Examples of the amino group include a dimethy phosphoryl group, a Sulfoxide group, an amide group (hav lamino group, a diethylaminoamino group, a dibutylamino ing no >N-H group and blocked, for example, Such that the group, a dioctylamino group, a N-methyl-N-hexylamino nitrogen atom forms a >N-Ra group (Ra is a Substituent group, a dicyclohexylamino group, a diphenylamino group other than hydrogen)), an urethane group (having no >N-H and a N-methyl-N-phenylamino group. group and blocked, for example, Such that the nitrogen atom forms a >N-Ra group (Ra is a substituent other than 0289 R to R' independently preferably represent an hydrogen)) or an ureido group (having no >N-H group and alkyl group, an aryl group, an alkoxy group or an aryloxy blocked, for example, Such that the nitrogen atom forms a group. From the viewpoint of the effect of the invention, it >N-Ra group (Ra is a Substituent other than hydrogen)) are is preferable that at least one of R to R is an alkyl group preferable. or an aryl group. It is more preferable that at least two of 0281. In the invention, the hydrogen bonding compound them independently represent an alkyl group or an aryl is particularly preferably a compound represented by the group. Further, it is preferable that R to Rare the same following formula (D). group, Since Such a compound is inexpensively available. 0290 Hereinafter, specific examples of the hydrogen bonding compound in the invention including the compound formula (D) represented by formula (D) are shown. However, the inven tion is not limited to them.

(D-1) 0282) In formula (D), R to R' independently represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group. These groups may be unsubstituted or substituted. 0283 Examples of a substituent when R, R for R has (O)--O) the Substituent include a halogen atom, an alkyl group, an US 2005/0069827 A1 Mar. 31, 2005 35

-continued -continued

(D-2) (D-8) C

Cl

P O O Cl

(D-3) (D-9) tle CH17 h - C3H17 O

(D-10)

(D-4) . |P ( ) O (D-11)

(D-5) OCH fl.

(O)-cis--a-O)O (D-12) O O O-P-O (D-6) O O (D-13)

(D-7) (O)- P-| -CH7 O (D-14) US 2005/0069827 A1 Mar. 31, 2005 36

0293. The crystal powder thus isolated is particularly -continued preferably used as a Solid-dispersed fine particle dispersion (D-15) in order to obtain stable performance. In addition, a method can also be preferably conducted in which powder of the reducing agent is mixed with powder the hydrogen bonding compound in the invention, and in which the resultant mixture is dispersed with a Suitable dispersant by a Sand grinder mill to form a complex.

(O) O-ocal 0294 The content of the hydrogen bonding compound in (D-16) the invention can be preferably in the range of 1 mol % to 200 mol %, more preferably in the range of 10 mol % to 150 mol %, and still more preferably in the range of 30 mol % to 100 mol % with respect to the reducing agent. C4H9 0295 2-8. Binder

(O) O - C4H9 0296 Any kind of polymer may be used as the binder of a layer containing the organic Silver Salt in the invention. (D-17) The binder is preferably transparent or translucent and generally colorless. Examples thereof include natural resins, polymers and copolymers, Synthetic resins, polymers and copolymers, and film forming media. Specific examples thereof include gelatins, rubbers, polyvinyl alcohols, hydroxyethylcelluloses, cellulose , cellulose acetate (O) O butylates, polyvinylpyrrollidones, casein, Starch, polyacrylic (D-18) acids, polymethyl methacrylates, polyvinyl chlorides, poly methacrylic acids, Styrene-maleic anhydride copolymers, Styrene-acrylonitrile copolymers, Styrene-butadiene copoly O i O) mers, polyvinylacetals (e.g., polyvinylformal and polyvinyl O (D-19) butylar), polyesters, polyurethanes, phenoxy resins, polyvi C8H17 nylidene chlorides, polyepoxides, polycarbonates, polyvinyl acetates, polyolefins, cellulose esters and polyamides. The N binder may be used as a solution in which it is dissolved in water or an organic Solvent, or an emulsion in which the X=o polymer is emulsified in a suitable solvent to form a film. C8H17 0297. In the invention, the glass transition temperature of (D-20) the binder of the layer containing the organic Silver Salt is preferably from 10° C. to 80° C., more preferably from 20° N-C8H17 C. to 70° C., and still more preferably from 23° C. to 65° C. 0298. In this specification, Tg is calculated by using the O following expression. (D-21) C4Ho 0299 Here, it is assumed that the polymer is formed by C N- C4H9 copolymerization of n monomer components from i=1 to i=n. Xi is the weight rate of i-th monomer (XXi=1), and Tgi O is the glass transition temperature (absolute temperature) of a homopolymer made of the i-th monomer alone. X is the sum of Xi/Tgis from i=1 to n. 0291 Specific examples of the hydrogen bonding com pound include not only the above-mentioned compounds but 0300 The values (Tgi) of the glass transition tempera also those described in Japanese Patent Application NoS. tures of homopolymers made of each monomer alone which 2000-192191 and 2000-194811. values are used herein are those described in Polymer Handbook (3rd Edition) (J. Brandrup, E. H. Immergut 0292 AS in the reducing agent, the hydrogen bonding (Wiley-Interscience, 1989)). compound of the invention can be incorporated in a coating liquid and in turn the photoSensitive material as a Solution, 0301 The polymer serving as the binder may be used an emulsified dispersion or a Solid-dispersed fine particle alone or, if necessary, two polymers can be used together. A dispersion. The hydrogen bonding compound in the inven polymer having a glass transition temperatures of 20° C. or tion forms a complex with a compound having a phenolic higher and a polymer having a glass transition temperature hydroxyl group through a hydrogen bond in a Solution. of less than 20 C. may be used together. When a blend of Therefore, the complex can be isolated as crystalline in Some two or more kinds of polymers having different glass tran combinations of the reducing agent and the compound Sition temperatures is used, it is preferable that weight represented by formula (A) in the invention. average Tg of the blend is within the above-described range. US 2005/0069827 A1 Mar. 31, 2005 37

0302) In the invention, performance is improved when polymer may be linear, branched or crosslinked. The poly the organic Silver Salt-containing layer is formed by coating mer can be a So-called homopolymer obtained by polymer a coating liquid whose Solvent(s) contains 30 mass % or izing one kind of monomer alone or a copolymer obtained more of water and drying the resultant film. Performance is by polymerizing two or more kinds of monomers. In the case more improved when the binder of the layer containing the of a copolymer, a random copolymer and a block copolymer organic Silver Salt is Soluble or dispersible in a water-based are usable. Solvent (aqueous Solvent). Performance is still more 0312 The number average molecular weight of the poly improved when the coating liquid contains a latex of a mer is 5000 to 1000000, preferably 10000 to 200000. When polymer whose equilibrium moisture content is 2 mass % or the molecular weight of the polymer is too Small, the lower at 25° C. and relative humidity of 60%. image-forming layer has insufficient mechanical Strength. 0303. The polymer is most preferably prepared such that When the molecular weight of the polymer is too larger, the the polymer has an ion conductivity of 2.5 mS/cm or lower. polymer has a poor film forming property. AS the preparation method thereof, a method in which a 0313 Typical examples of the polymer latex are shown Synthesized polymer is purified with a separation function below. In the following list, the polymer latex is shown by membrane can be used. Starting monomers, the unit of the parenthesized value is 0304. The water-based solvent herein in which the poly mass %, and the molecular weight is a number average mer is soluble or dispersible is water or a mixture of water molecular weight. When a polymer is made of at least one and a 70 mass % or less of a water-miscible organic Solvent. monomer including a polyfunctional monomer, the concept 0305 Examples of the water-miscible organic solvent of molecular weight cannot be applied to the polymer. This include an alcohol Solvent Such as methyl alcohol, ethyl is because the polymer has a crosslinked Structure. Thus, in alcohol and propyl alcohol, a celloSolve Solvent Such as the case of Such a polymer, the term “crosslinked' is shown, methylcellosolve, ethylcellosolve and bytylcellosolve, ethyl and description of the molecular weight is omitted. Tg acetate and dimethylformamide. indicates the glass transition temperature of the polymer. 0306 The “equilibrium moisture content at 25° C. and 0314 P-1: a polymer latex made of MMA (70), EA relative humidity of 60%' is represented by the following (27) and MAA (3) and having a molecular weight of expression, given that weight of the polymer in a moisture 37000 and Tg of 61° C. equilibrium state under an atmosphere of 25 C. and relative 0315 P-2: a polymer latex made of MMA (70), 2EHA humidity of 60% is W1 and weight of the polymer in an (20), St (5), and AA (5) and having a molecular weight absolute dry state at 25° C. is W0. of 40000 and Tg of 59° C. 0307 Equilibrium moisture content at 25 C. and relative 0316 P-3: a crosslinked polymer latex made of St (50), humidity of 60%={(W1-WO)/WOx100 (mass %) Bu (47) and MAA (3) having Tg of 17° C. 0308 With respect to the definition of the moisture 0317 P-4: a crosslinked polymer latex made of St (68), content and the method of measuring the Same, for example, Bu (29) and AA (3) having Tg of 17° C. Kobunshi Kogaku Koza 14 and Kobunshi Zairyo Shikenho (Polymer Engineering Course 14, Method of testing poly 0318 P-5: a crosslinked polymer latex made of St (71), mer material; compiled by Kobunshi Gakkai (the Society of Bu (26) and AA (3) and having Tg of 24 C. Polymer Science, Japan) and published by Chijin Shokan) 0319 P-6: a crosslinked polymer latex made of St (70), can be referred to. Bu (27) and IA (3) 0309 The equilibrium moisture content of the binder 0320 P-7: a crosslinked polymer latex made of St (75), polymer in the invention at 25 C. and relative humidity of Bu (24) and AA (1) and having Tg of 29 C. 60% is preferably 2 mass % or less, more preferably from 0.01 mass % to 1.5 mass %, and still more preferably from 0321) P-8: a crosslinked polymer latex made of St (60), 0.02 mass % to 1 mass %. Bu (35), DVB (3) and MAA (2) 0310. In the invention, a polymer dispersible in the 0322 P-9: a crosslinked polymer latex made of St (70), aqueous Solvent is particularly preferable. Examples of the Bu (25), DVB (2) and AA (3) dispersed State include lateX in which fine particles of a 0323 P-10: a polymer latex made of VC (50), MMA water-insoluble hydrophobic polymer are dispersed, and a (20), EA (20), AN (5) and AA (5) and having a State in which polymer molecules are dispersed in a molecu molecular weight of 80000 lar State or form micelles and are dispersed. Both cases are 0324 P-11: a polymer latex made of VDC (85), MMA preferable. The average particle diameter of the dispersion (5), EA (5) and MAA (5) and having a molecular particles is preferably 1 nm to 50000 nm, and more prefer weight of 67000 ably 5 nm to 1000 nm. Particle size distribution of the dispersion particles is not particularly limited. The disper 0325 P-12: a polymer latex made of Et (90) and MAA Sion particles can have a wide particle Size distribution or a (10) and having a molecular weight of 12000 monodisperse particle Size distribution. 0326 P-13: a polymer latex made of St (70), 2EHA 0311. In the invention, typical examples of the polymer (27) and AA (3) and having a molecular weight of dispersible in the aqueous Solvent include hydrophobic 130000 and Tg of 43° C. polymerS Such as acrylic polymers, polyesters, rubbers (e.g., 0327 P-14: a polymer latex made of MMA (63), EA an SBR resin), polyurethanes, polyvinyl chlorides, polyvinyl (35) and AA (2) and having a molecular weight of acetates, polyvinylidene chlorides and polyolefins. The 33000 and Tg of 47° C. US 2005/0069827 A1 Mar. 31, 2005 38

0328 P-15: a crosslinked polymer latex made of St 0347 The styrene-butadiene copolymer latex is prefer (70.5), Bu (26.5) and AA (3) and having Tg of 23° C. ably a polymer P-3 to P-8, P-14, or P-15, or any of commercial products LACSTAR-3307B, LACSTAR-7132C 0329 P-16: a crosslinked polymer latex made of St and NIPOL LX 416. (69.5), Bu (27.5) and AA (3) and having Tg of 20.5° C. 0348 The organic silver salt-containing layer of the 0330 Abbreviations in the above structures indicate the photosensitive material in the invention may contain a following monomers. hydrophilic polymer Such as gelatin, polyvinyl alcohol, 0331) MMA: methyl methacrylate methyl cellulose, hydroxypropyl cellulose or carboxymethyl cellulose, if necessary. 0332 EA: ethyl acrylate 0349 The amount of the hydrophilic polymer is prefer 0333 MAA: methacrylic acid ably 30 mass % or less, and more preferably 20 mass % or less based on the total amount of the binder(s) of the organic 0334 2EHA: 2-ethylhexyl acrylate Silver Salt-containing layer. 0335) St: styrene 0350 The organic silver salt-containing layer (the image forming layer) in the invention preferably contains the 0336 Bu: butadiene polymer latex as the binder. As for the amount of the binder 0337) AA: acrylic acid in the organic Silver Salt-containing layer, the weight ratio of all the binders to the organic silver salt is from 1/10 to 10/1, 0338) DVB: divinylbenzene and preferably 1/5 to 4/1. 0339 VC: vinyl chloride 0351. This organic silver salt-containing layer is usually the photosensitive layer (image-forming layer) containing 0340) AN: acrylonitrile the photosensitive silver halide which is a photosensitive 0341 VDC: vinylidene chloride silver salt. In this case, the weight ratio of all the binders to the silver halide is preferably in the range of 400 to 5, and 0342 Et: ethylene more preferably 200 to 10. 0343) IA: itaconic acid. 0352. The total amount of the binder in the image forming layer in the invention is preferably from 0.2 g/m to 0344) The polymer latexes listed above are commercially 30 g/m, and more preferably from 1 g/m to 15 g/m. The available, and the following polymers can be utilized. image-forming layer in the invention may contain a Examples of the acrylic polymer include SEVIAN A-4635, crosslinking agent for crosslinking and a Surfactant to 4718 and 4601 (all manufactured by Daicel Chemical Indus improve a coating property. tries, Ltd.), and NIPOL LX 811, 814,821,820 and 857 (all manufactured by Nippon Zeon Co., Ltd.). Examples of the 0353 A solvent (for simplicity, a solvent and a dispersion polyester include FINETEX ES 650, 611, 675 and 850 (all medium are in common referred to as “a solvent”) of the manufactured by Dainippon Ink and Chemicals, Inc.), and coating liquid for the organic Silver Salt-containing layer WD-size and WMS (both manufactured by Eastman Chemi coating liquid of the photosensitive material in the invention cal). Examples of the polyurethane include HYDRAN AP may be an aqueous Solvent containing 30 mass % or more 10, 20, 30 and 40 (all manufactured by Dainippon Ink and of water. As a component other than water, any water Chemicals, Inc.). Examples of the rubber include LAC miscible organic Solvent may be used. Examples thereof STAR 7310K, 3307B, 4700H and 7132C (all manufactured include methyl alcohol, ethyl alcohol, isopropyl alcohol, by Dainippon Ink and Chemicals, Inc.), and NIPOL LX 416, methylcellosolve, ethylcellosolve, dimethylformamide and 410, 438C and 2507 (all manufactured by Nippon Zeon Co., ethyl acetate. The content of water in the aqueous Solvent is Ltd.). Examples of the polyvinyl chloride include G351 and preferably 50 mass % or more, and more preferably 70 mass G576 (both manufactured by Nippon Zeon Co., Ltd.). % or more. Examples of the polyvinylidene chloride include L502 and L513 (both manufactured by Asahi Chemical Industry Co., 0354 Solvents having the following compositions are Ltd.). Examples of the polyolefin include CHEMIPEARL preferable: water, a mixture of water and methyl alcohol at S120 and SA100 (both manufactured by Mitsui Petrochemi a mass ratio of 90/10, a mixture of water and methyl alcohol at a mass ratio of 70/30, a mixture of water, methyl alcohol cal Industries, Ltd.). and dimethylformamide at a mass ratio of 80/15/5, a mixture 0345 One of these polymer latexes may be used alone or, of water, methyl alcohol and ethylcelloSolve at a mass ratio if necessary, two or more thereof can be used together. of 85/10/5 and a mixture of water, methyl alcohol and isopropyl alcohol at a mass ratio of 85/10/5. 0346) The polymer latex used in the invention is particu larly preferably a styrene-butadiene copolymer latex. The 0355 2-9. Antifogging Agent weight ratio of Styrene monomer units and butadiene mono mer units in the Styrene-butadiene copolymer is preferably 0356) 1) Organic Polyhalogenated Compound from 40:60 to 95:5. The ratio of the sum of the styrene monomer units and the butadiene monomer units to all the 0357 The photosensitive material and the thermographic monomers of the copolymer is preferably 60 to 99 mass %. material of the invention preferably include a compound The preferable range of molecular weight is the same as represented by the following formula (H) as an antifoggant. above. Q-(Y)-C(Z) (Z)X Formula (H) US 2005/0069827 A1 Mar. 31, 2005 39

0358 Informula (H), Q represents an alkyl group, an aryl still more preferably -SO- or -C(=O)N(R)- or group or a heterocyclic group. Y represents a divalent -C(=O)- or -SO-, and most preferably -SO-. R linking group. n represents 0 or 1. Each of Z and Z. represents a hydrogen atom, an aryl group or an alkyl group, represents a halogen atom, and X represents a hydrogen more preferably a hydrogen atom or an alkyl group, and atom or an electron-attractive group. most preferably a hydrogen atom. 0359. In formula (H), when Q is an aryl group, Q is preferably a phenyl group having, as a Substituent, an 0368 n is 0 or 1, and preferably 1. electron-attractive group whose Hammett's Substituent con stant Op is a positive value. With respect to Hammett's 0369 Specific examples of the compound of formula (H) substituent constant, Journal of Medicinal Chemistry, 1973, in the invention are shown below. However, the invention is vol. 16, No. 11, pp. 1207-1216 can be referred to. not limited to them. 0360 Examples of the electron-attractive group include halogen atoms, alkyl groups having as a Substituent an electron-attractive group, aryl groups having as a Substituent (H-1) an electron-attractive group, heterocyclic groups, alkyl- or aryl-Sulfonyl groups, acyl groups, alkoxycarbonyl groups, carbomoyl groups and Sulfamoyl groups. t SOCBr 0361 Specific examples thereof include halogen atoms (H-2) (e.g., a fluorine atom (Op: 0.06), a chlorine atom (Op: 0.23), a bromine atom (op: 0.23) and an iodine atom (op. 0.18)), trihalomethyl groups (a tribromomethyl group (Op: 0.29), a trichloromethyl group (op: 0.33) and a trifluoromethyl SOCBr3 group (Op: 0.54)), a cyano group (Op: 0.66), a nitro group (H-3) (Op: 0.78), aliphatic, aryl or heterocyclic Sulfonyl groups (e.g., a methaneSulfonyl group (Op: 0.72)), an aliphatic, aryl or heterocyclic acyl group (e.g., an acetyl group (Op: 0.50) and a benzoyl group (Op: 0.43)), alkynyl groups (e.g., a O. C=CH group (op. 0.23)), aliphatic, aryl or heterocyclic (H-4) oxycarbonyl groups (e.g., a methoxycarbonyl group (Op: 0.45) and a phenoxycarbonyl group (Op: 0.44)), a carbamoyl group (Op: 0.36), a Sulfamoyl group (Op: 0.57), a Sulfoxide group, a heterocyclic group and a phosphoryl group. N SOCBr3 (H-5) 0362 Op is preferably from 0.2 to 2.0, and more prefer S ably from 0.4 to 1.0. X-soca, 0363 The electron-attractive group is preferably a halo N gen atom, a carbamoyl group, an alkoxycarbonyl group, an (H-6) alkylsulfonyl group, an alkyphosphoryl group, a carboxyl N-N group, an alkyl- or aryl-carbonyl group or an arylsulfonyl group, more preferably a halogen atom, a carbamoyl group or an arylsulfonyl group, or a carbamoyl group, an alkoxy ---. carbonyl group, an alkylsulfonyl group or an alkylphospho (H-7) ryl, and most preferably a carbamoyl group. 0364 X is preferably an electron-attractive group. The l electron-attractive group is preferably a halogen atom, an aliphatic, aryl or heterocyclic Sulfonyl group, an aliphatic, aryl or heterocyclic acyl group, an aliphatic, aryl or hetero BrC Oses, cyclic oxycarbonyl group, a carbamoyl group or a Sulfamoyl (H-8) group, more preferably a halogen atom or a carbamoyl CONHC Ho(n) group, and most preferably a halogen atom. 0365 Among the halogen atoms, a chlorine atom, a bromine atom and an iodine atom are preferable. A chlorine atom and a bromine atom are more preferable. A bromine SOCBr atom is most preferable. (H-9) 0366 Each of Z and Z is preferably a bromine atom or an iodine atom, and more preferably a bromine atom. 0367 Y represents preferably -C(=O)-, -SO-, si-( SO-, -C(=O)N(R)- or -SON(R)-, more prefer ably -C(=O)-, -SO-, -SO- or -C(=O)N(R)-, and still more preferably -C(=O)-, -SO- or SOCBr C(=O)N(R)-; or -C(=O)-, -SO- or -SO , US 2005/0069827 A1 Mar. 31, 2005

-continued -continued (H-18) (H-10) N-N

CH -K N > SOCBr3 O SOCBr (H-19) CONHC Ho(n)

-C2H5 (H-11) SOCHBr, ONN (H-20) CHs CONHCH7(n) SOCBr3 O SOCBrCN C4H9 (H-12) (H-21) SO2NN1 SOCBr3 C4H9

O n SOCBr3 SOCB2UESr. (H-22) (H-13) OH COOCH13 N S. M N N N SOCBr3 SOCBr3 (H-23) (H-14) SONa CONHCHCOONa O SOCBr SOCBr3 (H-24) (H-15) COOH

SOCBr3

(H-25) SOCBr3 (H-16) CONH COCH

SOCBr (H-26) SOCBr3 SOCBr3 (H-17)

CONHCHCOOH SO SOCBr3 (H-27) CBrCONH -X- NHCOCBr US 2005/0069827 A1 Mar. 31, 2005 41

represented by formula (XI) described in JP-A No. -continued 59-193447, compounds described in JP-B No. 55-12581, (H-28) compounds represented by formula (II) described in JP-A SOCBrCONHC Ho No. 60-153039. The azolium salt may be contained in any portion of the photoSensitive material. However, the azolium Salt is preferably contained in a layer on a side of a Support (H-29) which Side has the photosensitive layer, and more preferably SOCBrCONHCHCOOH the organic Silver Salt-containing layer. 0379 The azolium salt may be added at any step of preparation of a coating liquid. When it is added to the organic Silver Salt-containing layer, it may be added at any Step from preparation of the organic Silver Salt to preparation of the coating liquid, however preferably within a period 0370. The compound represented by formula (H) in the from completion of preparation of the organic Silver Salt to invention is preferably used in an amount of 10' to 0.8 mol, a time just before coating. The azolium Salt may be added in more preferably in an amount of 10 to 0.1 mol, and still any form Such as powder, a Solution or a fine particle more preferably in an amount of 5x10 to 0.05 mol per mol dispersion. Further, it may be added to a Solution including of the non-photoSensitive Silver Salt of the image-forming any other additive Such as a Sensitizing dye, the reducing layer. agent or a color-toning agent. 0371. In particularly, when the silver halide with a high content of Silver iodide according to the invention is used, 0380 The amount of the azolium salt in the invention is the addition amount of the compound of formula (H) is preferably from 1x10" mol to 2 mol, and more preferably important to obtain a Sufficient fogging preventing effect. from 1x10 mol to 0.5 molper mol of silver, but may be out Most preferably, the compound is used in an amount of of the above range. 5X10 to 0.03 mol. 0381 2-10. Other Additives 0372. In the invention, the compound represented by 0382) 1) Mercapto, Disulfide and Thions formula (H) can be incorporated in the photosensitive mate 0383. The photosensitive material and the thermographic rial in the same manner as incorporation of the reducing material of the invention may include a mercapto com agent. pound, a disulfide compound and/or a thion compound may 0373 The melting point of the compound represented by in order to inhibit, accelerate or control development, to formula (H) is preferably 200° C. or less, and more prefer improve a spectral Sensitization effect, or to improve ably 170° C. or less. storability before and after development. Examples thereof include compounds described in JP-A No. 10-62899, para 0374. As other organic polyhalogenated compound for graphs O067 to 0069, compounds represented by formula use in the invention, those disclosed in official gazettes (I) of JP-A No. 10-186572 including specific compounds described in JP-A No. 11-65021, paragraphs 0111 to described in paragraphs 0033 to 0052), compounds O112 can be used. In particular, an organic halogenated described in EP-A1 No. 0803764, page 20, lines 36 to 56, compound represented by formula (P) of JP-A NO. 2000 and compounds described in JP-A No. 2001-100358. 284399, an organic polyhalogenated compound represented Among them, a mercapto-Substituted heteroaromatic com by formula (II) of JP-A No. 10-339934 and an organic pound is preferable. polyhalogenated compound described in JP-A No. 2001 33911 are preferable. 0384 2) Color-Toning Agent 0375 Other Antifoggant 0385) The photothermographic material of the invention preferably contains a color-toning agent. The Color-toning 0376 Examples of other antifoggants include mercury agent is described in JP-A No. 10-62899, paragraphs 0.054 (II) salts in JP-A No. 11-65021, paragraph 0113), benzoic to 0055), EP-A No. 0803764A1, page 21, lines 23 to 48, acids in the same document, paragraph 0114), Salicylic acid JP-A No. 2000-356317 and Japanese Patent Application No. derivatives in JP-A No. 2000-206642, formalin scavenger 2000-187298. In particular, phthalazinones (phthalazinone, compounds represented by formula (S) in JP-A No. 2000 phthalazinone derivatives and metal Salts thereof, Such as 221634, triazine compounds in claim 9 of JP-A No. 4-(1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7- 11-352624, compounds represented by formula (III) in JP-A dimethoxyphthalazinone and 2,3-dihydro-1,4-phthala No. 6-11791 and 4-hydroxy-6-methyl-1,3,3a,7-tetrazain Zinedione); combinations of phthalazinones and phthalic dene. acids (e.g., phthalic acid, 4-methylphthalic acid, 4-nitro phthalic acid, diammonium phthalate, Sodium phthalate, 0377 Moreover, other antifogging agent, a stabilizer and potassium phthalate and tetrachlorophthalic anhydride); a Stabilizer precursor that can be used in the invention can phthalazines (phthalazine, phthalazine derivatives and metal also be any of those disclosed in official gazettes described Salts thereof, Such as 4-(1-naphthyl)phthalazine, 6-isopro in JP-A No. 10-62899, paragraph 0070 and EP-A No. pylphthalazine, 6-t-butylphthalazine, 6-chlorophthalazine, 0803764A1, page 20, line 57 to page 21, line 7, and 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine) are compounds described in JP-A Nos. 9-281637 and 9-329864. preferable. In particular, when the color-toning agent is used 0378. The photothermographic material in the invention together with Silver halide having a high Silver iodide may contain azolium Salt for the purpose of fogging pre content, combined used of phthalazines and phthalic acids is vention. Examples of the azolium Salt include compounds preferable. US 2005/0069827 A1 Mar. 31, 2005 42

0386 The amount of phthalazines is preferably 0.01 to 0.3 mol, more preferably 0.02 to 0.2 mol, and most prefer ably 0.02 to 0.1 mol per mol of the organic silver salt. The amount is an important factor for accelerated development, Formula (H) which is a subject for the silver halide emulsion of the A1 A2 invention having a high Silver iodide content, and appropri A-N-N-Bo ate Selection of the amount can make a Sufficient develop ment property and low fogging compatible. Formula (G) X W 0387 3) Plasticizer and Lubricant ni? 0388. The photosensitive material and the thermographic C n material can contain a plasticizer, and/or a lubricant in the R1 H photosensitive layer (image-forming layer). The plasticizer Formula (P) and the lubricant are described in JP-A No. 11-65021, R1 paragraph O117). The material may also contain a slipping + agent, which is described in JP-A No. 11-84573, paragraphs R-Q-R 0061 to 0.064 and Japanese Patent Application No. R X 11-106881, paragraphs 0049 to 0062). 0389) 4) Dye and Pigment Formula (A) Y, 0390 The photosensitive layer in the invention may f V contain any dye and/or any pigment (e.g., C.I. Pigment Blue Z1 C=CH-X 60, C.I. Pigment Blue 64 or C.I. Pigment Blue 15:6) so as , / to improve color tone, inhibit generation of interference s -v fringe at the time of laser exposure, or inhibit irradiation. O They are described in detail in WO98/36322, JP-A Nos. 10-2684.65 and 11-338.098. Formula (B) Y, 0391 5) Ultrahigh Contrasting Agent and Nucleus Form 2. Y=CH X ing Agent 2 / - Util X2 NC 0392. In order to form an ultrahigh contrast image suit V able for use in making of printing plates, the photoSensitive Y material and the thermographic material of the invention preferably contains an ultrahigh contrasting agent in the Formula (C) image-forming layer. Examples of the ultrahigh contrasting Z1's agent include compounds described in JP-A Nos. 11-65021, f paragraph 0118 and 11-223898, paragraphs O136 to X1 Y1 0.193), compounds represented by formulas (H), (1) to (3), (A) and (B) of Japanese Patent Application No. 11-87297, and compounds represented by formulas (III) to (V) of Japanese Patent Application No. 11-91652 (specific com R R2 pounds: Formula 21 to Formula 24). An addition method and the amount of the ultrahigh contrasting agent are also described in the above applications. A high contrast accel 0395. In formula H). A represents an aliphatic group, an erator is described in JP-A No. 11-65021, paragraph 0102) aromatic group, a heterocyclic group or a -Go-Do group and JP-A No. 11-223898 paragraphs 0194 to 0195). which may have a Substituent, and Bo represents a blocking group. Both of A and A are hydrogen atoms. Alternatively, 0393 Next, the nucleus forming agent which can be used one A and A is a hydrogen atom and the other is an acyl in the invention will be described. The nucleus forming agent in the invention is a compound capable of decreasing group, a Sulfonyl group or an oxalyl group. Go represents the amount of Silver which amount is necessary to obtain a -CO- group, -COCO- group, -CS- group, predetermined Silver image density. While there are Some C(=NG.D.)- group, -SO-group, -SO-group or mechanisms of action for decreasing function, a compound -P(O) (G.D.)- group. G represents a single bond, -O- improving the covering power of developed Silver is pref group, -S-group or -N(D)- group. D represents an erable in the invention. The covering power of the developed aliphatic group, an aromatic group, a heterocyclic group or Silver means an optical density of Silver per unit amount. a hydrogen atom. When a plurality of DS are contained in 0394 Typical examples of the nucleus forming agent one molecule, they may be identical to or different from each include a hydrazine derivative compound represented by the other. Do represents a hydrogen atom, an aliphatic group, an following formula (H), a vinyl compound represented by the aromatic group, a heterocyclic group, an amino group, an following formula (G), a quaternary onium compound rep alkoxy group, an aryloxy group, an alkylthio group or an resented by the following formula (P) and cyclic olefin arylthio group. Do is preferably a hydrogen atom, an alkyl compounds represented by formulae (A), (B) and (C). group, an alkoxy group, or an amino group. US 2005/0069827 A1 Mar. 31, 2005 43

0396. In formula (H), the aliphatic group represented by to H-35 in formula Nos. 12 to 18 and compounds H-1-1 to A is preferably one having from 1 to 30 carbon atoms, and H-4-5 in formula Nos. 20 to No. 26 of JP-A No. 2002 more preferably a linear, branched or cyclic alkyl group 131864. having from 1 to 20 carbon atoms including a methyl group, an ethyl group, a t-butyl group, an octyl group, a cyclohexyl 0402. The compound represented by formulae (H-1) to group and a benzyl group. These exemplified groupS may (H-4) of the invention can be easily synthesized by a known have an appropriate Substituent (for example, an aryl group, method. The compound can be Synthesized with reference an alkoxy group, an aryloxy group, an alkylthio group, an to, for example, U.S. Pat. Nos. 5,464,738 and 5,496,695. arylthio group, a Sulfoxy group, a Sulfonamide group, a 0403. Other examples of the hydrazine derivatives to be Sulfamoyl group, an acylamino group, or a ureido group). preferably used include compounds H-1 to H-29 described 0397. In formula (H), the aromatic group represented by in columns 11 to 20 of U.S. Pat. No. 5,545,505 and com A is preferably a monocyclic or condensed cyclic aryl pounds 1 to 12 described in columns 9 to 11 of U.S. Pat. No. group including a benzene ring and naphthalene ring. The 5,464,738. heterocyclic ring represented by A is preferably a mono 0404 Next, formula (G) will be explained. In formula cyclic or condensed hetero cyclic ring containing at least one (G), X and R has a cis-form, but compounds in which X and hetero atom Selected from nitrogen, Sulfur, and oxygen R has a trans-form are also included in formula (G). It is also atoms. Examples thereof include a pyrrolidine ring, an applicable to expressions of the Structure of Specific com imidazole ring, a tetrahydrofuran ring, a morpholine ring, a pounds. pyridine ring, a pyrimidine ring, a quinoline ring, a thiazole 0405. In formula (G), X represents an electron-attractive ring, a benzothiazole ring, a thiophene ring and a furan ring. group, and W represents a hydrogen-atom, an alkyl group, The aromatic group, the heterocyclic ring and the -Go-Do an alkenyl group, an alkynyl group, an aryl group, a het group represented by Ao may have a Substituent. Ao is more erocyclic group, a halogen atom, an acyl group, a thioacyl preferably an aryl group or -Go-Do group. group, an oxalyl group, an OXyoxalyl group, a thiooxalyl 0398. Further, in formula (H), Ao preferably contains at group, an OXamoyl group, an oxycarbonyl group, a thiocar least one diffusion resistant group or a group adsorptive to bonyl group, a carbamoyl group, a thiocarbamoyl group, a Silver halide. The diffusion resistant group is preferably a Sulfonyl group, a Sulfinyl group, an oxySulfinyl group, a ballast group ordinarily used in an immobile photographic thiosulfinyl group, a Sulfamoyl group, an oxySulfamoyl additive Such as a coupler. Examples of the ballast group group, a thiosulfamoyl group, a Sulfinamoyl group, a phos include a photographically inactive alkyl group, alkenyl phoryl group, a nitro group, an imino group, an N-carbon group, alkynyl group, alkoxy group, phenyl group, phenoxy ylimino group, an N-Sulfonylimino group, a dicyanoethyl group, and alkyl phenoxy group, and the number of carbon ene group, an ammonium group, a Sulfonium group, a atoms in the Substituent moiety is preferably 8 or more in phosphonium group, a pyrylium group, or an immonium total. grOup. 0399. In formula (H), examples of the group adsorptive 0406 R represents a halogen atom, a hydroxyl group, an to Silver halide include thiourea, a thiourethane group, a alkoxy group, an aryloxy group, a hetero cyclic oxy group, mercapto group, a thioether group, a thione group, a het an alkenyloxy group, an acyloxy group, an alkoxycarbony erocyclic ring group, a thioamide heterocyclic group, a loxy group, an aminocarbonyloxy group, a mercapto group, mercapto heterocyclic group, and an absorptive group an alkylthio group, an arylthio group, a hetero cyclic thio described in JP-A No. 64-90439. group, an alkenylthio group, an acylthio group, an alkoxy carbonylthio group, an aminocarbonylthio group, an organic 0400. In formula (H), Bo represents a blocking group, or inorganic Salt (for example, a Sodium Salt, a potassium preferably -Go-Do group. Go represents -CO- group, Salt, and a silver Salt) of the hydroxyl group or the mercapto COCO-group, -CS-group, -C(=NGD) group, group, an amino group, an alkylamino group, a cyclic amino -SO- group, -SO- group or -P=(O) (G.D.)- group (for example, a pyrolidino group), an acylamino group. Go is preferably -CO- group and -COCO group, an oxycarbonylamino group, a hetero cyclic group, (a group. G represents a single bond, -O-group, -S- five or six-membered nitrogen-containing hetero ring, for group, or -N(D)- group. D represents an aliphatic example, a benzotriazolyl group, an imidazolyl group, a group, an aromatic group, a heterocyclic group or a hydro triazolyl group, and a tetrazolyl group), an ureido group and gen atom. When a plurality of DS are present in one a sulfonamide group. X and W, and/or X and R may molecule, they may be identical with or different from each respectively join to each other to form a cyclic Structure. other. Do represents a hydrogen atom, an aliphatic group, an Examples of the ring formed by X and W include pyra aromatic group, a heterocyclic group, an amino group, an Zolone, pyrazolidinone, cyclopentanedione, B-ketolactone, alkoxy group, an aryloxy group, an alkylthio group, or an and B-ketolactam. arylthio group. Do is preferably a hydrogen atom, an alkyl group, an alkoxyl group, or an amino group. A and A2 are 0407. In formula (G), the electron-attractive group rep hydrogen atoms, or one of them is a hydrogen atom and the resented by X is a substituent which can have a substituent other represents an acyl group (e.g., an acetyl group, a constant Op of a positive value. Specific examples thereof trifluoroacetyl group, or a benzoyl group), a Sulfonyl group include a Substituted alkyl group (e.g., a halogen-Substituted (e.g., a methaneSulfonyl group, or a toluenesulfonyl group) alkyl group), a Substituted alkenyl group (e.g., a cyanovinyl or an oxalyl group (e.g., an ethoxalyl group). group), a Substituted or unsubstituted alkynyl group (e.g., a trifluoromethylacetylenyl group, and a cyanoacetylenyl 0401 Specific examples of the compound represented by group) a Substituted aryl group (e.g., an cyanophenyl group), formula (H) include, but are not limited to, compounds H-1 a Substituted or unsubstituted hetero cyclic group (e.g., a US 2005/0069827 A1 Mar. 31, 2005 44 pyridyl group, a triaZynyl group, and a benzooxazolyl a butenyl group), alkynyl groups (e.g., a propargyl group, group), a halogen atom, a cyano group, an acyl group (e.g., and a butynyl group), aryl groups (e.g., a phenyl group, and an acetyl group, a trifluoroacetyl group, a formyl group), a a naphthyl group), heterocyclic groups (e.g., a piperidinyl thioacetyl group (e.g., a thioacetyl group, and a thioformyl group, a peperazinyl group, a morphorinyl group, a pyridyl group), an oxalyl group (e.g., a methyloxalyl group), an group, a furyl group, a thienyl group, a tetrahydrofuryl Oxyoxalyl group (e.g., an ethoxalyl group), a thiooxalyl group, a tetrahydrothienyl group, and a Sulfolanyl group), group (e.g., an ethylthiooxalyl group), an oxamoyl group and an amino group. (e.g., a methyloxamoyl group), an oxycarbonyl group (e.g., an ethoxycarbonyl group), a carboxyl group, a thiocarbonyl 0414 Examples of the ring which R to Rjoin with each group (e.g., an ethylthiocarbonyl group), a carbamoyl group, other to form include a piperidine ring, a morpholine ring, a a thiocarbamoyl group, a Sulfonyl group, a Sulfinyl group, an piperazine ring, a quinacridine ring, a pyridine ring, a pyrrol Oxysulfonyl group (e.g., an ethoxysulfonyl group), a thio ring, an imidazol ring, a triazole ring, and a tetrazole ring. Sulfonyl group (e.g., an ethylthiosulfonyl group), a Sulfa 0415 The group represented by R to R may have a moyl group, an oxysulfinyl group (e.g., a methoxysulfiny Substituent Such as a hydroxyl group, an alkoxy group, an group), a thiosulfinyl group (e.g., a methylthiosulfinyl aryloxy group, a carboxyl group, a Sulfo group, an alkyl group), a Sulfinamoyl group, a phosphoryl group, a nitro group, or an aryl group. Each of R, R, R and R is group, an imino group, an N-carbonylimino group (e.g., an preferably a hydrogen atom or an alkyl group. N-acetylimino group), an N-Sulfonylimino group (e.g., an N-methaneSulfonylimino group), a dicyanoethylene group, 0416 Examples of the anion represented by X include an ammonium group, a Sulfonium group, a phosphonium inorganic and organic anions Such as halogen ions, a Sulfate group, a pyrylium group, and an immonium group. A ion, a nitrate ion, an acetate ion and a p-toluene Sulfonate heterocycle in which any combination of an ammonium ion. group, a Sulfonium group, a phosphonium group and an 0417. As the structure of formula P, a structure described immonium group forms a ring are also included in X. in the columns Nos. O153 to 0163 of JP-A No. 2002-131864 Substituents having a op value of 0.30 or more are particu is preferable. larly preferable. 0418 Specific examples of the compound of formula (P) 04.08 Examples of the alkyl group represented by W include, but are not limited to, Compounds P-1 to P-52 and include methyl, ethyl, and trifluoromethyl groups. Examples T-1 to T-18 represented by formulas 53 to 62 described in of the alkenyl group include vinyl, halogen-substituted JP-ANO. 2002-131864. Vinyl, and cyanovinyl groups. Examples of the alkynyl group include acetylenyl and cyanoacetylenyl groups. 0419. The quaternary onium compound can be synthe Examples of the aryl group include nitrophenyl, cyanophe sized according to a known method. For example, the nyl, and pentafluorophenyl groups. Examples of the hetero tetrazolium compound can be Synthesized on the basis of a cyclic group include pyridyl, pyrimidyl, triazinyl, Succinim method described in Chemical Reviews, vol. 55, page 335 to ide, tetrazolyl, triazolyl, imidazolyl, and benzooxazolyl 483. groups. W is preferably an electron-attractive group having 0420 Next, compounds represented by (A) and (B) will a positive Op value, and more preferably an electron be explained in detail. In formula (A), Z represents a attractive group having a value Op of 0.30 or more. non-metal atomic group capable of forming a 5- to 7-mem bered ring structure together with - Y-C(=CH-X)- 04.09 R is preferably a hydroxyl group, a mercapto C(=O)-. Z. preferably represents an atomic group includ group, an alkoxy group, an alkylthio group, a halogen atom, ing atoms Selected from a carbon atom, an oxygen atom, a an organic or inorganic Salt of the hydroxyl group or the Sulfur atom, a nitrogen atom and a hydrogen atom. Several mercapto group, or a hetero cyclic group, more preferably a hydroxyl group, an alkoxy group, an organic or inorganic atoms Selected from them bond to each other via a single Salt of the hydroxyl group or the mercapto group, or a hetero bond or a double bond to form a 5- to 7-membered ring cyclic group, and Still more preferably a hydroxyl group, or structure together with -Y-C(=CH-X)-C(=O) an organic or inorganic Salt of the hydroxyl group or the 0421 Z may have a Substituent, and Z perse may be a mercapto group. part of an aromatic or non-aromatic carbocyclic ring or an aromatic or non-aromatic heterocyclic ring. In this case, the 0410. Further, among the substituents represented by X 5- to 7-membered ring structure formed by Z and - Y - and W, those having therein a thioether bond are preferable. C(=CH-X)-C(=O)- forms a condensed ring struc 0411 Specific examples of the compound represented by ture. formula (G) include, but are not limited to, Compounds 1-1 0422. In formula (B), Z represents a non-metal atomic to 92-7 of formulae 27 to 50 disclosed in JP-A No. 2002 group capable of forming a 5- to 7-membered ring structure 131864. together with - Y-C(=CH-X-)-C (Y)N 0412. In formula (P), Q represents a nitrogen atom or a 0423 Z. preferably represents an atomic group including phosphor atom, and R, R, R and R. each represent a atoms Selected from a carbon atom, an oxygen atom, a Sulfur hydrogen atom or a Substituent, and X represents an anion. atom, a nitrogen atom and a hydrogen atom, and Several Further, R to R may join to each other to form a ring. atoms Selected from them bond to each other via a single 0413 Examples of the Substituents represented by R to bond or a double bond to form a 5- to 7-membered ring R include alkyl groups (e.g., a methyl group, an ethyl structure together with-Y-C (=CH-X-)-C (Y)N group, a propyl group, a butyl group, a hexyl group, and a 0424 Z may have a substituent, or Z itself may be a part cyclohexyl group), alkenyl groups (e.g., an allyl group, and of an aromatic or non-aromatic carbocyclic ring, or an US 2005/0069827 A1 Mar. 31, 2005 45 aromatic or non-aromatic heterocyclic ring. In this case, the group, or ap-dodecylphenylthio group), a heterocyclic thio 5- to 7-membered ring structure formed by Z and - Y - group (for example, a 1-phenyltetrazoyl-5-thio group, a C(=CH-X-)-C(Y)N-forms a condensed ring structure. 2-methyl-1-phenyltriazolyl-5-thio group, or a mercap tothidiazolylthio group), an amino group, an alkylamino 0425. In the case where Z and Z have a substituent, group (for example, a methylamino group, a propylamino typical examples of the Substituent include a halogen atom group, an octylamino group, or a dimethylamino group), an (e.g., a fluorine atom, a chlorine atom, a bromine atom and arylamino group (for example, an anilino group, a naphthy an iodine atom), an alkyl group (including an aralkyl group, lamino group, or an O-methoxyanilino group), a heterocyclic a cycloalkyl group, and an active methine group), an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, amino group (for example, a pyridylamino group, or a a quaternary nitrogen-containing heterocyclic group (for benzotriazole-5-ylamino group), an acylamino group (for example, a pyridinio group), an acyl group, an alkoxycar example, an acetoamide group, an octanoylamino group, or bonyl group, an aryloxycarbonyl group, a carbamoyl group, a benzoylamino group), a Sulfonamide group (for example, a carboxy group and a Salt thereof, a Sulfonylcarbamoyl a methaneSulfonamide group, a benzene Sulfonamide group, group, an acylcarbamoyl group, a Sulfamoylcarbamoyl or a dodecylsulfonamide group) or a heterocyclic group. group, a carbazoyl group, an oxalyl group, an OXamoyl 0429 The heterocyclic group is an aromatic or non group, a cyano group, a thiocarbamoyl group, a hydroxyl aromatic, Saturated or unsaturated, monocyclic or con group, an alkoxy group (including groups repeatedly con densed, Substituted or unsubstituted heterocyclic group, taining an ethyleneoxy group unit or a propyleneoxy group including an N-methylhydantoyl group, an N-phenylhydan unit), an aryloxy group, a heterocyclic oxy group, acyloxy toyl group, a Succinimide group, a phthalic imide group, an group, a (alkoxy- or aryloxy-) carbonyloxy group, a car N,N'-dimethylurazolyl group, an imidazolyl group, a ben bamoyloxy group, a Sulfonyloxy group, an amino group, an Zotriazolyl group, an indazolyl group, a morpholino group, (alkyl-, aryl- or heterocyclic-)amino group, an N-Substituted and a 4,4-dimethyl-2,5-dioxo-oxazolyl group. nitrogen-containing heterocyclic group, an acylamino group, a Sulfonamide group, an ureido group, a thioureido 0430. Further, examples of the salt include salts of alkali group, an imido group, a (alkoxy- or aryloxy-) carbony metals (e.g., Sodium, potassium and lithium) and alkaline lamino group, a Sulfamoylamino group, a Semicarbazide earth metals (e.g., magnesium and calcium), Silver Salts, group, a thiosemicarbazide group, a hydrazino group, a quaternary ammonium salts (e.g., a tetraethyl ammonium quaternary ammonio group, an oxamoylamino group, a Salt, and a dimethyl cetyl benzyl ammonium salt) and (alkyl- or aryl-) Sulfonylureido group, an acylureido group, quaternary phosphonium salts. In formulas (A) and (B), Y. an acylsulfamoylamino group, a nitro group, a mercapto and Y each represent-C(=O)- or -SO-. group, a (alkyl-, aryl- or heterocyclic-) thio group, a (alkyl 0431. The preferred range of the compounds represented or aryl-) Sulfonyl group, a (alkyl- or aryl) Sulfinyl group, a by formulas (A) and (B) is described in the columns 0027 to Sulfo group and a Salt thereof, a Sulfamoyl group, an 0043 of JP-A No. 11-231459. Specific examples of the acylsulfamoyl group, a Sulfonylsulfamoyl group and a Salt compounds represented by formulas (A) and (B) include, thereof, a group containing a phosphoric acid amide or a but are not limited to, Compounds 1 to 110 in Tables 1 to 8 phosphate Structure, a silyl group and a Stannyl group. Those of JP-A No. 11-231.459. Substituents may further have any of those Substituents. 0432 Next, the compound represented by formula (C) in 0426) Next, Y will be explained. In formula (B), Y. the invention will be explained in detail. In formula (C), X. represents a hydrogen atom or a Substituent. When Y represents an oxygen atom, a Sulfur atom or a nitrogen atom. represents a Substituent, examples thereof include an alkyl group, an aryl group, a heterocyclic group, a cyano group, an When X represents a nitrogen atom, the bond between X acyl group, an alkoxycabonyl group, an aryloxycarbonyl and Z may be a single bond or a double bond. When the group, a carbamoyl group, an amino group, a (alkyl-, aryl bond is a Single bond, the nitrogen atom may bond to a or heterocyclic-)amino group, an acylamino group, a Sul hydrogen atom or any Substituent. fonamide group, an ureido group, a thioureido group, an 0433 Examples of the substituent include an alkyl group imide group, an alkoxy group, an aryloxy group, and a (including an aralkyl group, a cycloalkyl group, and an (alkyl-, aryl- or heterocyclic-) thio group. active methine group), an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, an acyl group, an 0427 Those substituents may have any substituent, and alkoxycarbonyl group, an aryloxycarbonyl group, a carbam examples thereof include those of the substituent which Z, oyl group, and a (alkyl-, aryl- or heterocyclic-) Sulfonyl and/or Z may have. grOup.

0428. In formulae (A) and (B), X and X each represent 0434 Y represents s SO s a hydroxy group (or a salt thereof), an alkoxy group (for example, a methoxy group, an ethoxy group, a propoxy SO-, -C (=NR)-, or group, an isopropoxy group, an octyloxy group, a dodecy 0435 Z represents a non-metallic atomic group which loxy group, a cetyloxy group, or a t-butoxy group), an can form a 5- to 7-membered ring containing X and Y. The aryloxy group (for example, a phenoxy group, a p-t-pen atomic group which forms the ring is an atomic group tylphenoxy group, or a p-t-octylphenoxy group), a hetero including two to four atoms other than metal atoms which cyclic oxy group (for example, a benzotriazolyl-5-oxy two to four atoms may bond to each other via a Single bond group, or a pyridinyl-3-oxy group), a mercapto group (or a or a double bond and which may have a hydrogen atom or Salt thereof), an alkylthio group (for example, a methylthio any Substituent (for example, an alkyl group, an aryl group, group, an ethylthio group, a butylthio group, or a dode a heterocyclic group, an alkoxy group, an alkylthio group, an cylthio group), an arylthio group (for example, a phenylthio acyl group, an amino group, or an alkenyl group). US 2005/0069827 A1 Mar. 31, 2005 46

0436 When Z forms a 5- to 7-membered ring containing 0442. In formula (C), when R and R. each represent a X and Y, the ring is a Saturated or unsaturated heterocycle, monovalent group, the monovalent groups represented by and may be a monocycle or a condensed ring. When Y is C R, and R2 is preferably the following groups having from 0 (=NR) group or (R)C=N group, the condensed ring may to 25 carbon atoms in total: an alkyl group, an aryl group, a have a ring in which R or R bonds to a Substituent which heterocyclic group, an alkoxy group, an aryloxy group, a Z has. heterocyclicoxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, an alky 0437. In formula (C), R, R2, R and Reach represent a lamino group, an arylamino group, a heterocyclic amino hydrogen atom or a Substituent. However, R and R never group, an ureido group, an imide group, an acylamino group, bond to each other to form a cyclic Structure. a hydroxy group, or a Salt thereof, a mercapto group or a Salt 0438. When R and R each represent a monovalent thereof, or an electron-attractive Substituent. The electron group, examples thereof include a halogen atom (e.g., a attractive Substituent is a Substituent which can have a fluorine atom, a chlorine atom, a bromine atom and an iodine Hammet's Substituent constant Op of a positive value and atom), an alkyl group (including an aralkyl group, a Specific examples thereof include a cyano group, a Sulfa cycloalkyl group, and an active methine group), an alkenyl moyl group, an alkylsulfonyl group, an arylsulfonyl group, group, an alkynyl group, an aryl group, a heterocyclic group, a Sulfonamide group, an imino group, a nitro group, a a quaternary nitrogen-containing heterocyclic group (Such halogen atom, an acyl group, a formyl group, a phosphoryl as a pyridinio group), an acyl group, an alkoxycarbonyl group, a carboxyl group (or a Salt thereof), a Sulfo group (or group, an aryloxycarbonyl group, a carbamoyl group, a a Salt thereof), a Saturated or unsaturated heterocyclic group, carboxy group and a Salt thereof, a Sulfonylcarbamoyl an alkenyl group, an alkynyl group, an acyloxy group, an group, an acylcarbamoyl group, a Sulfamoylcarbamoyl acylthio group, a Sulfonyloxy group, or an aryl group having group, a carbazoyl group, an oxalyl group, an OXamoyl any of these electron-attractive groups. These groups may group, a cyano group, a thiocarbamoyl group, a hydroxyl have any Substituent. group and a salt thereof, an alkoxy group (including groups repeatedly containing an ethyleneoxy group unit or a pro 0443) In formula (C), when R and R. each represent a pyleneoxy group unit), an aryloxy group, a heterocyclic oxy monovalent Substituent, each of R and R is preferably an group, an acyloxy group, a (alkoxy- or aryloxy-) carbony alkoxy group, an aryloxy group, a heterocyclic oxy group, loxy group, a carbamoyloxy group, a Sulfonyloxy group, an an alkylthio group, an aryl thio group, a heterocyclic thio amino group, an (alkyl-, aryl- or heterocyclic-)amino group, group, an amino group, an alkylamino group, an arylamino an N-Substituted nitrogen-containing heterocyclic group, an group, a heterocyclic amino group, an ureido group, an acylamino group, a Sulfonamide group, an ureido group, a imide group, an acylamino group, a Sulfonamide group, a thioureido group, an imide group, a (alkoxy- or aryloxy-) heterocyclic group, a hydroxyl group or a Salt thereof or a carbonylamino group, a Sulfamoylamino group, a Semicar mercapto group or a Salt thereof. bazide group, a thiosemicarbazide group, a hydrazino group, 0444. In formula (C), R and R is more preferably a a quaternary ammonio group, an oxamoylamino group, a hydrogen atom, an alkoxy group, an aryloxy group, an (alkyl- or aryl-) Sulfonylureido group, an acylureido group, alkylthio group, an arylthio group, a heterocyclic group, a an acylsulfamoylamino group, a nitro group, a mercapto hydroxy group or a Salt thereof, or a mercapto group or a Salt group and a Salt thereof, a (alkyl-, aryl- or heterocyclic-)thio thereof. group, a (alkyl- or aryl-) Sulfonyl group, a (alkyl- or aryl-) Sulfinyl group, a Sulfo group and a Salt thereof, a Sulfamoyl 0445. In formula (C), most preferably, one of R and R. group, an acylsulfamoyl group, a Sulfonylsulfamoyl group is a hydrogen atom, and the other is an alkoxy group, an and a Salt thereof, a phosphoryl group, a group containing a aryloxy group, an alkylthio group, an arylthio group, a phosphoric amide or phosphoric acid ester Structure, a silyl heterocyclic group, a hydroxy group or a Salt thereof, or a group and a Stannyl group. The Substituents may further mercapto group or a Salt thereof. have Such a monovalent Substituent. 0446. In formula (C), when R represents a substituent, the Substituent is preferably an alkyl group having from 1 to 0439 When R and R, each represent a substituent, 25 carbon atoms in total (including an aralkyl group, a examples thereof include those of the substituent which R cycloalkyl group, and an active methine group), an alkenyl and R may have, but exclude halogen atoms. R and R may group, an aryl group, a heterocyclic group, a quaternary bond to Z to form a condensed ring. nitrogen-containing heterocyclic group (for example, a pyri 0440 Preferred examples of the compound by formula dinio group), an acyl group, an alkoxycarbonyl group, an (C) are as follows. In formula (C), Z preferably forms a 5 aryloxycarbonyl group, a carbamoyl group, a (alkyl- or aryl) to 7-membered ring together with X and Y, and is pref Sulfonyl group, a (alkyl- or aryl-) sulfinyl group, a Sulfos erably an atomic group including two to four atoms Selected ulfamoyl group, an alkoxy group, an aryloxy group, a from a carbon atom, a nitrogen atom, a Sulfur atom and an heterocyclic oxy group, an alkylthio group, an arylthio oxygen atom. The hetero ring which Z forms together with group, a heterocyclic thio group or an amino group. The X and Y is preferably a hetero ring preferably having from Substituent is more preferably an alkyl group or an aryl 3 to 40 carbon atoms, more preferably from 3 to 25 carbon grOup. atoms and most preferably from 3 to 20 carbon atoms in 0447. In formula (C), when R represents a substituent, total. Z. preferably contains at least one carbon atom. the Substituent is preferably an alkyl group having from 1 to 0441. In formula (C), Y is preferably -C(=O)-, 25 carbon atoms in total (including an aralkyl group, a C(=S)-, -SO, or -(R)C=N-, more preferably cycloalkyl group, and an active methine group), an aryl C(=O)-, -C(=S), or -SO- and most preferably group, a heterocyclic group, a quaternary nitrogen-contain -C(=O)-. ing heterocyclic group (for example, a pyridinio group), an US 2005/0069827 A1 Mar. 31, 2005 47 acyl group, an alkoxycarbonyl group, an aryloxycarbonyl more preferably from 0.1 um to 2 um. In the present group, a carbamoyl group, a (alkyl- or aryl-) sulfonyl group, application, other Solid dispersions preferably include par a (alkyl- or aryl-) Sulfinyl group, a SulfoSulfamoyl group, an ticles having a particle size within the range described alkoxy group, an aryloxy group, a heterocyclic oxy group, above. an alkylthio group, an arylthio group, or a heterocyclic thio group. The Substituent is preferably an alkyl group, an aryl 0457. The photothermographic material processed by group, an alkoxy group, an aryloxy group, a heterocyclic rapid development with a developing time of 20 Sec or leSS oxy group, an alkylthio group, an arylthio group or a preferably contains the compound represented by formula heterocyclic thio group. When Y represents C(R)=N, a (H) or (P), and more preferably the compound represented carbon atom in Ybonds to the carbon atom to which X and by formula (H) among the nucleus forming agents described Y Bond. above. 0448 Specific examples of the compound of formula (C) include, but are not limited to, Compounds A-1 to A-230 of 0458. The photothermographic material which is formulae No. 6 to 18 described in JP-A No. 11-133546. required to have a low fogging property preferably contains 0449 The amount of the nucleus forming agent is in the the compound represented by formula (G), (A), (B), or (C) range of 10 to 1 mol, and preferably in the range of 10." and more preferably contains the compound represented by to 5x10" mol based on mol of the organic silver salt. formula (A) or (B). Further, the photothermographic mate rial which leSS changes photographic performance to envi 0450. The nucleus forming agent may be contained in a coating liquid and in turn the photothermographic material ronmental conditions even when used under various envi in any form Such as an emulsified dispersion, or a fine Solid ronmental conditions (e.g., temperature, and humidity) particle dispersion. preferably contains the compound represented by formula (C). 0451 An example of a well known emulsion dispersion method is a method in which the nucleus forming agent is 0459 Specific examples of the nucleus forming agent are dissolved in an oil Such as dibutyl phthalate, tricresyl shown below, but the invention is not limited to these phosphate, dioctyl cebacate or tri(2-ethylhexyl) phosphate examples. or an auxiliary Solvent Such as ethyl acetate or cyclohex anone, and adding a Surfactant Such as Sodium dodecylben ZeneSulfonate, Sodium oleoyl-N-methyl taurinate, or Sodium di(2-ethylhexyl)sulfoSuccinate to the resultant Solution, and SH-1 mechanically forming an emulsified dispersion from the OCH3 resultant. 0452. In this case, it is also preferable to add a polymer Such as C.-methylstyrene oligomer or poly(t-butylacryla (3– NHNHCHO mide) to control the viscosity and the refractive index of oil droplets. SH-2 0453 Further, an examples of a fine solid particle dis persion method is a method of dispersing powder of the nucleus forming agent in an appropriate Solvent Such as water by a ball mill, a colloid mill, a vibration ball mill, a N Sand mill, a jet mill, a roller mill or SuperSonic waves to prepare a Solid dispersion. In this case, a protective colloid ( ) NHNH-COO \ / (for example, polyvinyl alcohol), a Surfactant (for example, anionic Surfactant Such as Sodium triisopropylnaphthalene sulfonate (mixture of those having different substitution positions of three isopropyl groups)) may also be used. 0454. In the above-described mills, beads, for example, SH-3 Zirconia beads, are generally used as a dispersion medium, and Zr or the like leaching from the beads may Sometimes be introduced into the dispersion. Depending on the disper Sion condition, the amount thereof is usually within the S range of 1 ppm to 1000 ppm. If the content of Zr in the photoSensitive material is 0.5 mg or leSS per 1 g of Silver, Zr NHNH- co ( ) causes no practical problem. 0455 The aqueous dispersion preferably contains an antiseptic (for example, Sodium Salt of benzoisothiazoli none). SH-4 0456. The solid particle dispersion method is most pref C2H5OOC H erable for the nucleus forming agent and the agent is desirably added as fine particles with an average grain size NC OH of 0.01 um to 10 tim, preferably from 0.05 um to 5 um and US 2005/0069827 A1 Mar. 31, 2005 48

-continued -continued SH-5 SH-12 HC

H

NC OH OH SH-6

N 0460. In order to use formic acid or formate as a strong fogging material, it is preferable to incorporate it in a layer H O on a side of a Support having the image-forming layer containing the photosensitive Silver halide in an amount of FCOS OH 5 mmol or less, and preferably in an amount of 1 mmol or SH-7 leSS per mol of Silver. O 0461) When an ultrahigh contrasting agent is employed in C12H25 the photothermographic material of the invention, a com bined use of an acid formed by hydration of diphosphorous N pentoxide or a Salt thereof is preferable as Such. Examples C.H.1 ONa of the acid formed by hydration of diphosphorous pentoxide O or the Salt thereof include metaphosphoric acid (salts SH-8 thereof), pyrophoric acid (Salts thereof), orthophosphoric O acid (salts thereof), triphosphoric acid (Salts thereof), tetra H phosphoric acid (salts thereof) and hexamethylphosphoric a. acid (salts thereof). Among them, orthophosphoric acid N (salts thereof) and hexamethylphosphoric acid (salts thereof) C12H5OOC N are preferable. Specific Salts include Sodium orthophos phate, Sodium dihydrogen orthophosphate, Sodium hexam O ethaphosphate and ammonium hexamethaphosphate. Cl SH-9 0462. The amount of the acid formed by hydration of CHO215 H diphosphorous pentoxide or the Salt thereof (coating amount C-ONa per m of the photosensitive material) may be a desired amount in accordance with properties Such as Sensitivity and N N fogging, but is preferably 0.1 mg/m to 500 mg/m, and N O more preferably 0.5 mg/m° to 100 mg/ml. 0463 2-11. Preparation of Coating Liquid and Coating 0464) The Preparation temperature of the coating liquid for the image-forming layer in the invention is preferably 30° C. to 65° C., more preferably 35° C. to 60° C., and still NHCOC12H25 more preferably 35 C. to 55° C. In addition, it is preferable that the temperature of the coating liquid for the image SH-10 forming layer just after addition of the polymer latex is kept O in the range of 30° C. to 65° C. O 0465 3. Layer Configuration and Other Components N 0466. The silver halide photosensitive material and the photothermographic material of the invention can have a OH non-photoSensitive layer in addition to the photosensitive H layer or the image-forming layer. The non-photoSensitive SH-11 layer can be classified, according to arrangement thereof, into (a) a Surface protective layer disposed on the image O forming layer (side far from a Support), (b) an intermediate O layer disposed between the image-forming layerS or between N the image-forming layer and the protective layer, (C) an undercoat layer disposed between the image-forming layer SH and the Support, and (d) a back layer disposed on a side of H the Support which Side is opposite to the Side having the image-forming layer. US 2005/0069827 A1 Mar. 31, 2005 49

0467. In addition, the photosensitive material and the 0478. The amount of the decolorizable dye is determined photothermographic material may also have a layer which according to application of the dye. Generally, the amount is acts as an optical filter, and the layer is provided as the layer Such that an optical density (absorbance) measured at an (a) or (b). The photosensitive material and the photother objective desired wavelength is more than 0.1. The optical mographic material may also have an antihalation layer, and density is preferably 0.2 to 2. The amount of the dye to the antihalation layer is provided as the layer (c) or (d). obtain Such an optical density is generally about 0.001 g/m 0468. 1) Surface Protective Layer to about 1 g/m. 0469 The silver halide photosensitive material and the 0479. The optical density after thermal development can photothermographic material in the invention may have a be decreased to be 0.1 or lower by decolorizing the dye. Two Surface protective layer to inhibit adhesion of the image or more kinds of decolorizable dyes may be used together in forming layer. The Surface protective layer may be a single a thermally decolorizable recording material or the photo layer or plural layers. The detail of the Surface protective thermographic material. Similarly, two or more kinds of layer is described in JP-A Nos. 11-65021, paragraphs 0119) base precursors may be used together. to 0120) and 2001-348546. 0480. In such a heat decolorization using these decolori 0470 The surface protective layer in the invention Zable dye and base precursor, it is preferable to use a includes a binder, and the binder is preferably gelatin, but material which can decrease a melting point by 3 C. or more may be polyvinyl alcohol (PVA). A combination of polyvi when used together with the base precursor and which is nyl alcohol and gelatin is also preferable. AS the gelatin, an described in, for example, JP-A No. 11-352626, such as inert gelatin (e.g., Nitta gelatin 750TM) or a phthalated diphenylsulfone, or 4-chlorophenyl(phenyl)sulfone from the gelatin (e.g., Nitta gelatin 801TM) can be used. viewpoint of thermal decolorizability. 0471) PVA can be any of those described in JP-A No. 0481 3) Back Layer 2000-171936, paragraphs 0009 to 0020), and a com pletely saponified product, PVA-105, partially saponified 0482. The back layer applicable to the invention is products, PVA-205 and PVA-335, and modified polyvinyl described in JP-A No. 11-65021, paragraphs 0128 to alcohol, MP-203 (all are trade names of KURARAY Co., O130). LTD.) are preferably used. 0483 The photosensitive material and the photothermo graphic material of the invention may contain a colorant 0472. The coating amount (per m of the support) of having an absorption maximum in the range of 300 nm to polyvinyl alcohol in the protective layer (per layer) is 450 nm in order to improve Silver tone and reduce change of preferably 0.3 g/m to 4.0 g/m, and more preferably 0.3 image over time. Such a colorant is described in JP-A Nos. g/m to 2.0 g/m. 62-210458, 63-104046, 63-103235, 63-208846, 63-306436, 0473) The total coating amount (per m of the support) of 63-314535 and 1-61745, and Japanese Patent Application all the binders (including a water-Soluble polymer and a No. 11-276751. Such a colorant is usually contained in an latex polymer) in the Surface protective layer (per layer) is amount of 0.1 mg/m to 1 g/m, and is preferably contained preferably 0.3 g/m to 5.0 g/m, and more preferably 0.3 in the back layer disposed on the Side of the Support which g/m to 2.0 g/m. Side is opposite the Side having the photoSensitive layer. 0474) 2) Antihalation Layer 0484 4) Matting Agent 0475. The silver halide photosensitive material and the 0485 The photosensitive material and the photothermo photothermographic material of the invention may have an graphic material of the invention preferably contains a antihalation layer on a side far from an exposure light Source matting agent in the Surface protective layer and the back with respect to the photoSensitive layer. The antihalation layer in order to improve the conveying property of the layer is described in JP-A Nos. 11-65021, paragraphs 0123 material. The matting agent is described in JP-A No. to 0124), 11-223898, 9-230531, 10-36695, 10-104779, 11-65021, paragraphs 0126 and 0127. 11-231457, 11-352625 and 11-352626. 0486 The coating amount of the matting agent is pref 0476. The antihalation layer contains an antihalation dye erably from 1 mg to 400 mg, and more preferably from 5 mg having absorption at an exposure wavelength. When the to 300 mg per m of the photosensitive material. exposure wavelength is in the wavelength range of infrared light, an infrared ray-absorbing dye may be used as the 0487. The matted degree of the image-forming layer antihalation dye. In this case, the dye preferably has no Surface may be any value as far as So-called “Star defects', absorption in the visible light region. which are missing portions formed in an image area and which cause leak of light, do not occur. However, Bekk 0477. When a dye having absorption in visible light smoothness of the surface is preferably from 30 seconds to region is used to prevent halation, it is preferable that the 2000 seconds, and more preferably from 40 seconds to 1500 color of the dye does not Substantially remain in the material seconds. The Bekk smoothness can be easily determined by after image formation. For this purpose, a means for causing "Method for testing Smoothness of paper and paperboard by decolorization by heat of thermal development is preferably Bekk tester” defined in JIS P8119, or TAPPI standard used. In particular, it is preferable that a thermally decol method T479, which are incorporated by reference herein. orizable dye and a base precursor are contained in the non-photoSensitive layer to allow the layer to function as the 0488. In the invention, as for the matted degree of the antihalation layer. Such a technique is described in JP-A No. back layer, the Bekk smoothness of the back layer is 11-231.457. preferably from 10 seconds to 1200 seconds, more prefer US 2005/0069827 A1 Mar. 31, 2005 50 ably from 20 seconds to 800 seconds, and even more James “THE THEORY OF THE PHOTOGRAPHIC PRO preferably from 40 seconds to 500 seconds. CESS FOURTH EDITION" Macmillan Publishing Co., Inc. 1977) pp. 77-87. The hardening agent is preferably chrome 0489. In the invention, the matting agent is preferably alum, 2,4-dichloro-6-hydroxy-s-triazine sodium salt, N,N- incorporated in an outermost layer, a layer which acts as the ethylenebis(vinylsulfonacetamide), N,N-propylenebis(vi outermost layer, a layer close to the outer Surface of the photoSensitive material, or a layer which acts as a So-called nylsulfonacetamide), polyvalent metal ions shown on page protective layer. 78 of the above document, a polyisocyanate described in U.S. Pat. No. 4,281,060 and JP-A No. 6-208193, an epoxy 0490) 5) Polymer Latex compound described in JP-A No. 62-89048. 0491 A polymer latex may be incorporated in the surface 0500 The hardening agent is added as a solution to a protective layer or the back layer in the invention. coating liquid. When the hardening agent is added to a 0492. The polymer latex is described in “Gosei Jushi protecting layer coating liquid, it is added during a period Emulsion (Synthetic Resin Emulsion)”, compiled by Taira Starting from 180 minutes before coating and ending imme Okuda and Hiroshi Inagaki, published by Kobunshi Kanko diately before coating, and preferably during a period Start Kai (1978); “Gosei Latex no Oyo (Application of Synthetic ing from 60 minutes to 10 Seconds before coating. A mixing Latex)', compiled by Takaaki Sugimura, Yasuo Kataoka, method and mixing conditions are not particularly limited So Souichi Suzuki and Keishi Kasahara, published by Kobun long as the effects of the invention Satisfactorily Show. shi Kanko Kai (1993); and Soichi Muroi, “Gosei Latex no 0501 Specific examples of the mixing method include a Kagaku (Chemistry of Synthetic Latex)", published by method of mixing in a tank Such that an average residence Kobunshi Kanko Kai (1970). Specific examples thereof period, calculated from an adding flow rate and a Supplying include a methyl methacrylate (33.5 mass %)/ethyl acrylate flow rate to a coater, is allowed to be within a predetermined (50 mass %)/methacrylic acid (16.5 mass %) copolymer duration, and a method using a Static mixer described, for latex, a methyl methacrylate (47.5 mass %)/butadien (47.5 example, in N. Harnby, M. F. Edwards & A. W. Nienow, mass %)/itaconic acid (5 mass %) copolymer latex, an ethyl (translated by Koji Takahashi), “Liquid Mixing Technology” acrylate/methacrylic acid copolymer latex, a methyl meth Chap. 8, The Nikkan Kogyo Shimbun, Ltd. (1989). acrylate (58.9 mass %)/2-ethylhexyl acrylate (25.4 mass %)/styrene (8.6 mass %)/2-hydroxyethyl methacrylate (5.1 0502) 8) Surfactant mass %)/acrylic acid (2.0 mass %) copolymer latex, methyl 0503) A surfactant to be usable in the invention is methacrylate (64.0 mass %)/styrene (9.0 mass %)/butyl described in JP-A 11-65021, paragraph 0132). acrylate (20.0 mass %)/2-hydroxyethyl methacrylate (5.0 mass %)/acrylic acid (2.0 mass %) copolymer latex. 0504. In the invention, a fluorine-containing surfactant is preferably used. Typical examples of the fluorine-containing 0493 The content of the polymer latex is preferably 10 surfactant include compounds described in JP-A Nos. mass % to 90 mass %, and more preferably 20 mass % to 80 10-197985, 2000-19680 and 2000-214554. Further, a poly mass % on the basis of the total amount of all the binders meric fluorine-containing surfactant described in JP-A No. (including a water-soluble polymer and latex polymer) of 9-281636 is also preferably used. In the invention, use of the the Surface protective layer or the back layer. fluorine-containing Surfactant described in Japanese Patent 0494 6) Film Surface pH Application No. 2000-206560 is particularly preferable. 0495. The photothermographic material of the invention 0505) 9) Antistatic Agent preferably has a film Surface pH of 7.0 or less, more 0506 The photosensitive material and the photothermo preferably 6.6 or less before thermal development. Although graphic material of the invention may have an antistatic the lower limit thereof is not particularly limited, it is layer including any known metal oxide or an electrocon generally around 3. The pH is most preferably in the range ductive polymer. The antistatic layer may also serve as the or 4 to 6.2. undercoat layer, the back layer or the Surface protective 0496 An organic acid such as phthalic acid derivatives, layer, or may be disposed Separately from these layers. a nonvolatile acid Such as Sulfuric acid, or a volatile base Techniques described in JP-A Nos. 11-65021, paragraph Such as ammonia is preferably used to control the film O135), 56-143430, 56-143431, 58-62646, 56-120519 and surface pH from the viewpoint of lowering of the film 11-84573, paragraphs 0040 to 0051), U.S. Pat. No. 5,575, Surface pH. In particular, ammonia is preferably used to 957 and JP-A 11-223898, paragraphs 0078 to 0084) may achieve a low film Surface pH, because it evaporates easily be applied to the antistatic layer. and therefore it can be removed before coating or thermal development. 0507 10) Support 0508 A transparent support which can be used in the 0497. In addition, a combined use of a nonvolatile base invention is preferably a polyester film which has been Such as Sodium hydroxide, potassium hydroxide or lithium heated at a temperature in the range of 130 to 185 C. in hydroxide and ammonia is also preferable. A method for order to relax internal Strain remaining in the film during measuring the film surface pH is described in JP-A No. biaxial orientation and thereby eliminate heat shrinkage 2000-284399, paragraph 0123). distortion that may occur during thermal development, par 0498 7) Hardening Agent ticularly a polyethylene terephthalate film. 0499. A hardening agent may be contained in each of the 0509. The support of the photothermographic material to photoSensitive layer, the protective layer and the back layer be used together with an ultraViolet-luminescent Screen is in the invention. The hardening agent is described in T. H. preferably PEN. However, the Support is not restricted to the US 2005/0069827 A1 Mar. 31, 2005 same. PEN is preferably polyethylene-2,6-naphthalate. 0516) 12) Coating Method Polyethylene-2,6-naphthalate in the invention may be any 0517. The silver halide photosensitive material and the one in which a repeating Structural unit is Substantially photothermographic material in the invention may be pre reconstructed by an ethylene-2,6-naphthalenedicarboxylate pared by any coating method. Specific examples these unit, and includes not only non-copolymerized polyethyl include extrusion coating, slide coating, curtain coating, dip ene-2,6-naphthalenedicarboxylate but also copolymers in coating, knife coating, flow coating, and extrusion coating which 10% or less, preferably 5% or less of the number of using a hopper as described in U.S. Pat. No. 2,681,294. The the repeating Structural units are modified by other compo extrusion coating or Slide coating as described by Stephen F. nents, and mixtures and compositions including polyethyl Kistler, Petert M. Schweizer, “LIQUID FILM COATING” ene-2,6-naphthalate and any other polymer. (CHAPMAN & HALL, 1997), pp. 399 to 536 is preferably conducted, and the Slide coating is more preferably con 0510 Polyethylene 2,6-naphthalate is synthesized by ducted. bonding naphthalene-2,6-dicarboxylic acid or its functional 0518. An example of the form of a slide coater used in the derivative, and ethylene glycol or its functional derivative in slide coating is illustrated in FIG.11b. 1 on page 427 of the the presence of a catalyst under Suitable reaction conditions. Same document. Further, at least two layers can be Simul Polyethylene 2,6-naphthalate as referred to herein may be a taneously formed in accordance with any of coating methods copolymer or a mixed polyester obtained by adding at least described in British Patent No. 837,095, if necessary. one kind of a Suitable third component (modifier) to a reaction System before completion of polymerization of 0519. The organic silver salt-containing layer coating polyethylene 2,6-naphthalate. The Suitable third component liquid in the invention is preferably a So-called thixotropic is a compound having a divalent ester-forming functional fluid. With regard to the technique, JP-A No. 11-52.509 can group, for example, dicarboxylic acids Such as Oxalic acid, be referred to. adipic acid, phthalic acid, isophthalic acid, terephthalic acid, 0520. The viscosity of the organic silver salt-containing naphthalene-2,7-dicarboxylic acid, Succinic acid or diphenyl layer coating liquid in the invention at a shear rate of 0.1 S' ether dicarboxylic acid, or their lower alkyl esters, or is preferably from 400 mPa's to 100,000 mPa's, and more oxycarboxylic acids Such as p-oxybenzoic acid or p-oxy preferably from 500 mPa's to 20,000 mPa's. ethoxybenzoic acid, or their lower alkyl esters, or dihydric 0521. Further, the viscosity thereof at a shear rate of 1000 alcohols, Such as propylene glycol or trimethylene glycol. s' is preferably from 1 mPa is to 200 mPa's, and more Polyethylene 2,6-naphthalate or its modified polymer may preferably from 5 mPa's to 80 mPas. be a polymer whose terminal hydroxyl group(s) and/or 0522) 13) Packaging Material carboxyl group(s) is blocked with a monofunctional com pound Such as benzoic acid, benzoylbenzoic acid or benzy 0523. It is preferable that the photosensitive material and loxybenzoic acid, methoxypolyalkylene glycol, or may be a the photothermographic material of the invention are her polymer which is modified with an extremely Small amount metically packed by a packaging material having at least one of a trifunctional or tetrafunctional ester-forming compound, of a low oxygen permeability and a low moisture perme Such as glycerin or pentaerythritol Such that the resultant ability in order to prevent photographic properties thereof copolymer is Substantially linear. from being deteriorated at the time of Storage before being used, or, when the photosensitive material and the photo 0511. In the case of a photothermographic material for thermographic material are in roll form, prevent the material medical use, the transparent Substrate may be colored with from being curled or curly deformed. The Oxygen perme a blue dye (e.g., dye-1 described in Examples of JP-A No. ability is preferably 50 mL/atm/m-day or less, more pref 8-240877 or may be colorless. erably 10 mL/atm/m-day or less, and still more preferably 1.0 mL/atm/m-day or less at 25°C. The moisture perme 0512 Specific examples of the substrate are described in ability is preferably 10 g/atm/m-day or less, more prefer JP-A No. 11-65021, paragraph 0134). ably 5 g/atm/m°-day or less, and still more preferably 1 0513. An undercoat including a water-soluble polyester g/atm/m-day or less. Specific examples of the packing described in JP-A No. 11-84574, a styrene-butadiene material having the low oxygen permeability and/or the copolymer described in JP-A No. 10-186565 or a vinylidene moisture permeability include those described in JP-A Nos. chloride copolymer described in JP-A No. 2000-39684 and 8-254793 and 2000-206653. Japanese Patent Application No. 11-106881, paragraphs 0524 14) Other Techniques which can be Used 0063 to 0080) is preferably disposed on the substrate. 0525 Techniques which can be used in the photothermo 0514) 11) Other Additives graphic material of the invention are described in, for example, EP-A Nos. 803764A1 and 883022A1, WO98/ 0515. The silver halide photosensitive material and the 36322, JP-A Nos. 56-62648,58-62644, 9-43766, 9-281637, photothermographic material may further contain an anti 9-297367, 9-304869, 9-311405, 9-329865, 10-10669, oxidant, a Stabilizer, a plasticizer, an ultraViolet ray absor 10-62899, 10-69023, 10-186568, 10-90823, 10-171063, bent and/or a coating aid. One or more kinds of Solvents 10-186565, 10-186567, 10-186569 to 10-186572, described in JP-A No. 11-65021, paragraph 0133 may be 10-197974, 10-197982, 10-197983, 10-197985 to added to these additives. Various kinds of additives are 10-197987, 10-207001, 10-207004, 10-221807, 10-282601, contained in at least one of the photoSensitive layer and the 10-288823, 10-288824, 10-307365, 10-312038, 10-339934, non-photosensitive layer. For these, WO98/36322, EP-A 11-7100, 11-15105, 11-24200, 11-24201, 11-30832, No. 803764A1, JP-A Nos. 10-186567 and 10-186568 can be 11-84574, 11-65021, 11-109547, 11-125880, 11-129629, referred to. 11-133536 to 11-133539, 11-133542, 11-133543, US 2005/0069827 A1 Mar. 31, 2005 52

11-223898, 11-352627, 11-305377, 11-305378, 11-305384, is from 3.2 to 4.0. When the photothermographic material 11-305380, 11-316435, 11-327076, 11-338096, 11-338.098, with the characteristic curve is used in an X-ray photograph 11-338099, and 11-343420, Japanese Patent Application No. ing System in the invention, an X-ray image having excellent 2000-187298, JP-A Nos. 2001-200414, 2001-234635, 2002 photographic properties Such as a remarkably extended leg 20699, 2001-275471, 2001-275461, 2000-313204, 2001 and high gamma at a medium density area can be obtained. 292844, 2000-324888, 2001-293864, and 2001-348546. Thanks to the photographic properties, depiction becomes good in a low density region in which an X-ray transmission 0526) 15) Color Image Formation amount is Small Such as a mediastinum region or heart 0527 The multicolor photothermographic material may Shadow, and images of the lung field region, where an X-ray contain a combination of these two layerS for each color, or transmission amount is large, have a density which can be may contain all components in a Single layer as described in easily Seen, and contrast becomes good. U.S. Pat. No. 4,708,928. 0541. The photothermographic material having the 0528. In the case of multicolor photothermographic above-described preferable characteristic curve can be eas materials, a functional or non-functional barrier layer is ily produced by, for example, a method in which each of the generally disposed between the respective photoSensitive image-forming layerS on both Sides is constructed by two or layers (emulsion layers), as described in USP No. 4,460, more layers of Silver halide emulsion layerS having different 681. Sensitivities. In particular, it is preferable to form the image 0529 4. Image Forming Method forming layerS by using an emulsion having a high Sensi tivity in an upper layer and an emulsion having a low 0530 4-1. Exposure Sensitivity and contrasty photographic characteristics in a 0531. The photothermographic material of the invention lower layer. When the image-forming layer including Such may be a single-sided material having an image-forming two layers is employed, the ratio of the Sensitivity (Sensi layer only on one side of the Support, or a double-sided tivity difference) of the silver halide emulsion of the upper material having the image-forming layer on each side of the layer to that of the lower layer is from 1.5 to 20, and Support. preferably from 2 to 15. The ratio of the amount of the emulsion contained in the upper layer to that in the lower 0532 Double-sided Photothermographic Material layer differs in accordance with Sensitivity difference and 0533. The photothermographic material of the invention covering power of emulsions to be used. Generally, the can be preferably used for an image forming method in larger the Sensitivity difference, the Smaller the percentage which an X-ray image is recorded by using X-ray intensi of the amount of the emulsion having a high Sensitivity. For fying Screens. example, when the Sensitivity difference is two and the covering powers of the two emulsions are approximately the 0534. The image forming method using the photother Same, the ratio of the amount of the emulsion having a high mographic material include the following Steps of: Sensitivity to that of the emulsion having a low Sensitivity is 0535 (a) disposing the photothermographic mate preferably in the range of 1:20 to 1:50 in terms of silver rial between a pair of X-ray intensifying Screens to amount. obtain an assembly for image formation; 0542 For crossover cut (double-sided photosensitive 0536 (b) arranging a subject between the assembly material) and antihalation (single-sided photosensitive mate and an X-ray Source; rial), a dye, or a combination of a dye and a mordant described in JP-A No. 2-68539, page 13, left lower column, 0537 (c) irradiating the subject with X-rays having line 1 to page 14, left lower column, line 9, may be an energy level in the range of 25 kVp to 125 kVp; employed. 0538 (d) removing the photothermographic mate 0543) Next, a fluorescent intensifying screen (radiation rial from the assembly; and intensifying screen) in the invention will be described. The 0539 (e) heating the removed photothermographic basic structure of the radiation intensifying Screen has a material at a temperature in the range of 90° C. to Support and a fluorescent Substance layer disposed on one 180° C. Side of the Support. In the fluorescent Substance layer, a 0540. The photothermographic material for use in the fluorescent Substance is dispersed in a binder. A transparent assembly according to the invention is preferably Such that protective coat is provided on the Surface of the fluorescent an image obtained by Stepwise exposing the photothermo Substance layer opposite to the Support (the Surface not graphic material with X-rays followed by thermal develop facing the Support) to protect the fluorescent Substance layer ment thereof has a characteristic curve that is drawn on a from chemical degeneration or mechanical shock. rectangular coordinate in which the coordinate axis unit 0544. In the invention, typical examples of the fluores lengths of optical density (D) and light exposure logarithm cent Substance include tungState fluorescent Substance (e.g., (log E) are equal to each other, and in which characteristic CaWO, MgWO, and CaWO:Pb), terbium-activated rare curve an average gamma (Y) formed by a point, whose earth oxysulfide fluorescent Substance (e.g., YOS:Tb, density is the Sum of a minimum density (Dmin) and 0.1, GdOS:Tb, LaOS:Tb, (Y.Gd).O.S:Tb, and and a point, whose density is the Sum of the minimum (YGd)OS:Tb, Tm), terbium-activated rare earth phosphate density (Dmin) and 0.5, is from 0.5 to 0.9, and an average fluorescent substance (e.g., YPO:Tb, GdPO:Tb, and gamma (Y) formed by a point, whose density is the Sum of LaPO:Tb), terbium-activated rare earth oxyhalide fluores the minimum density (Dmin) and 1.2, and a point, whose cent substance (e.g., LaCBr:Tb, LaCBr:Tb,Tm, LaC)Cl:Tb, density is the sum of the minimum density (Dmin) and 1.6 LaOCl:Tb,Tm, LaGBr:Tb, GdOBr:Tb, and GdOCl:Tb), thu US 2005/0069827 A1 Mar. 31, 2005 53 lium-activated rare earth oxyhalide fluorescent Substance 0551. The fluorescent Substance is more preferably a (e.g., LaCBr:Tm, and LaC)Cl:Tm), barium sulfate fluores bivalent Eu activated barium halide fluorescent Substance cent substance (e.g., BaSO, Pb, BaSO:Eu", and (Ba, represented by formula: MXX:Eu. M includes Ba as the Sr)SO:Eu?"), bivalent europium-activated alkaline earth main ingredient thereof and can preferably contain a Small metal phosphate fluorescent Substance (e.g., amount of any other compound Such as Mg, Ca or Sr. X and (Ba-PO):Eu?", and (Ba-PO):Eu?"), bivalent europium X each represent a halogen atom which can be selected activated alkaline earth metal fluorohalide fluorescent Sub arbitrarily from F, Cl, Brand I. X is preferably fluorine. X stance (e.g., BaFCl:Eu?", BaFBr:Eu?", BaFCl:Eu?", Tb, can be Selected from Cl, Br and I, and a composition BaFBr:Eu", Tb, BaFBaCl-KCl:Eu", and (Ba, including Some of the halogen compounds in admixture can Mg)F. BaCl-KCl:Eu"), iodide fluorescent substance (e.g., also be preferably used. CsI:Na, CsI:Tl, NaI, and KI:Tl), sulfide fluorescent Sub stance (e.g., ZnS: Ag(Zn, Cd)S. Ag, (Zn,Cd)S:Cu, and (Zn, 0552) More preferably, X is Br. Eu is europium. Eu Cd)S:Cu,Al), hafnium phosphate fluorescent Substance Serving as the emission center is preferably contained in a (e.g., Hfp.O.7:Cu), YTaO, and YTaO into which any acti ratio of 107 to 0.1, and more preferably 10' to 0.05 with Vator is incorporated as an emission center. However, the respect to Ba. A Small amount of other compound may also fluorescent Substance for use in the invention is not be preferably mixed. The fluorescent Substance is most restricted to them, and any fluorescent Substance which can preferably BaFCl:Eu, BaFBr:Eu, or BaFBr-I:Eu. emit light in the Visible or near ultraViolet region due to 0553 The fluorescence intensifying screen preferably has irradiation of radiation may be employed. a Support, and an undercoat layer, a fluorescent Substance 0545. In the X-ray fluorescence intensifying screen pref layer, and a Surface protective layer which are disposed on erably used in the invention, 50% or more of emission light the Support. has a wavelength in the range of 350 nm to 420 nm. In 0554. The fluorescent substance layer can be formed by particular, the fluorescent Substance is preferably a bivalent dispersing particles of the fluorescent Substance in a Solution Eu-activated fluorescent Substance and more preferably a containing an organic Solvent and a binder resin to prepare bivalent Eu-activated barium halide fluorescent Substance. a liquid dispersion, directly applying the liquid dispersion to The emission wavelength region is preferably from 360 nm a Support (or to an undercoat layer in the case where the to 420 nm, and more preferably 370 nm to 420 nm. Further, undercoat layer Such as a light reflection layer is formed on the fluorescent screen has more preferably 70% or more, and the Support), and drying the resultant coating. Alternatively, more preferably 85% or more of emission light in the region the liquid dispersion may be applied to a separately prepared described above. provisional Support, and the resultant coating is dried to 0546) The rate of the emission light is calculated by the prepare a fluorescent Substance sheet, and then the fluores following method. That is, the emission spectrum is mea cent Substance sheet may be peeled from the provisional Sured given that emission wavelength is shown by antiloga Support and bonded to a Support by using an adhesive. rithm disposed at a reggular interval on the abscissa and the 0555. The grain size of the fluorescent substance particles number of emitted photons is shown by the ordinate. The has no particular restriction and is usually within the range value obtained by dividing the area on the chart in which of about 1 um to 15 um and preferably within the range of area wavelength is from 350 nm to 420 nm by the area of the about 2 um to 10 um. The volumetric filling rate of the entire emission spectrum on the chart is defined as the rate fluorescent Substance particles in the fluorescent Substance of emission in the wavelength range of 350 nm to 420 nm. layer is preferably high. It is usually within the range of 60 When the photothermographic material of the invention is to 85%, preferably within the range of 65 to 80% and more combined with a fluorescent intensifying Screen having preferably within the range of 68 to 75% (the mass rate of emission light in Such a wavelength region, high Sensitivity the fluorescent Substance particles in the fluorescent Sub can be attained. stance layer is usually 80 mass % or more, preferably 90 0547. In order that most of emission light of the fluores mass % or more and more preferably 95 mass % or more). cent Substance exists in the wavelength region described The binder resin, the organic Solvent, and various kinds of above, the fluorescent Substance preferably has a narrow half optional additives used in formation of the fluorescent breadth of the emission light. The half breadth is preferably Substance layer are described in various known literatures. 1 nm to 70 nm, more preferably 5 nm to 50 nm and still more The thickness of the fluorescent Substance layer can be Set preferably 10 nm to 40 nm. in accordance with an aimed Sensitivity. The thickness of the screen for the front side is preferably within the range of 70 0548. There is no particular restriction on the fluorescent lum to 150 um, and the thickness of the screen for the back Substance to be used So long as the light emission described side is prefearbly within the range of 80 um to 400 lum. The above is obtained. For improved sensitivity which is an X-ray absorptivity of the fluorescent Substance layer object of the invention, the fluorescent Substance is prefer depends on the coating amount of the fluorescent Substance ably an Eu-activated fluorescent Substance having bivalent particles. Eu as an emission center. 0556. The fluorescent Substance layer may be a single 0549. However, the invention is not limited thereto. layer or may have two or more layers. The fluorescent 0550 Examples of such a fluorescent substance include Substance layer preferably has one to three layerS and more BaFCl:Eu, BaFBr:Eu, BaFI:Eu and those in which the preferably one or two layers. For example, layers including halogen compositions of the above materials are modified, the fluorescent Substance particles of different grain sizes BaSO:Eu, SrFBr:Eu, SrFCl:Eu, SrFI:Eu, (Sr, with a relatively narrow grain size distribution may be Ba)Al2Si2Os:Eu, SrBO-F:Eu, SrMgPO,:Eu, Stacked. In this case, the grain Size of the fluorescent Sr.(POI):Eu, and Sr.P.O.7:Eu. Substance particles contained in a layer nearer to the Support US 2005/0069827 A1 Mar. 31, 2005 54 may be Smaller. It is particularly preferable to apply fluo However, it is preferable that the surface protective layer has rescent Substance particles of a large grain size to a layer on no adsorption, Since Such a Surface protective layer leSS a Surface protective layer Side and to apply fluorescent reduces Screen Sensitivity. Alternatively, in order to com Substance particles of a Small grain size to a layer on the pensate insufficient Scattering, the Surface protective layer Support Side. The Small grain size is preferably within the may have a slight absorptivity. The absorption length is range of 0.5 um to 2.0 Lim and the large grain size is within preferably 800 um or more, and more preferably 1200 um or the range of 10 um to 30 lum. more. The light Scattering length and the light absorption 0557. Further, the fluorescent Substance layer may be length can be calculated according to the formula based on formed by mixing fluorescent Substance particles of different the Kubelka-Munk's theory by using values measured by the grain sizes. Alternatively, as described in JP-B No. following method. 55-33560, page 3, left column, line 3 to page 4, left column, 0563 At first, three or more film specimens having line 39, the fluorescent Substance layer may have a structure different thicknesses and the same composition as that of the in which the grain size distribution of the fluorescent Sub Surface protective layer to be measured are prepared. Then, stance particles has a gradient. Usually, the fluctuation the thickness (um) and the diffuse transmittance (%) of each coefficient of the grain size distribution of the fluorescent of the film Specimens are measured. The diffuse transmit substance particles is within the range of 30 to 50% but tance can be measured by a device in which an integrating mono-dispersed fluorescent Substance particles with a fluc Sphere is attached to an ordinary Spectrophotometer. In tuation coefficient of 30% or less may also be preferably measurement in the invention, an autographic spectropho used. tometer (Model U-3210, manufactured by Hitachi Ltd.) 0558. It has been attempted to provide a preferred sharp provided with a 150 cp integrating sphere (150-0901) is used. neSS by dyeing the fluorescent Substance layer with respect It is necessary that the measuring wavelength coincides with to the emission wavelength. However, the layer is preferably the peak wavelength of the main emission of the fluorescent designed Such that dyeing level thereof is as low as possible. Substance in the objective fluorescent Substance layer to The absorption length of the fluorescent Substance layer is which the Surface protective layer is attached. Then, the preferably 100 um or more and more preferably 1000 um or measured values of the thickness (um) and the diffuse transmittance (%) of the film are introduced into the fol OC. lowing formula (A) derived from the Kubelka-Munk's theo 0559 The scattering length of the layer is preferably retical formula. The formula (A) can be introduced simply, designed to be 0.1 um to 100 um and more preferably 1 um for example, from the formulae in 5.1.12 to 5.1.15, page to 100 um. The Scattering length and the absorption length 403, in “Fluorescent substance Handbook” (edited by Fluo can be calculated according to the formula based on the rescent Substance Dogakukai, published from Ohm Co. in Kubelka-Munk's theory. 1987) under the boundary condition for the diffuse trans 0560. The Support can be appropriately selected from mittance factor T (%). various kinds of Supports used in known radiation intensi formula (A) fying Screens according to the purpose. For example, a polymer film containing a white pigment Such as titanium 0564) In the formula, T represents a diffuse transmittance dioxide or a polymer film containing a black pigment Such (%), d represents a film thickness (um), and C. and f are as carbon black can be preferably used. An undercoat layer defined by the following formulae: Such as a light reflection layer containing a light reflection material may also be disposed on the Surface of the Support (Surface on which the fluorescent Substance layer is formed). A light reflection layer as described in JP-A No. 2001 0565 T (diffuse transmittance: %) and d (film thickness: 124898 can also be preferably used. In particular, a light pum) measured of the three or more films are respectively reflection layer including yttrium oxide as described in introduced into formula (A) to calculate K and S that satisfy Example 1 of the above-mentioned patent application or a formula (A). The Scattering length (um) is defined as 1/S and light reflection layer as described in Example 4 of the patent the absorption wavelength (um) is defined as 1/K. application is preferably used. AS for the another preferred 0566 It is preferable that the Surface protective layer has light reflection layer, JP-A No. 2001-124898, from page 3, a structure in which light Scattering particles are dispersed right column, line 15 to page 4, right column, line 23 can be and contained in the resin material. The optical refractive referred to. index of the light Scattering particles is usually 1.6 or more 0561. A surface protective layer is preferably provided on and preferably 1.9 or more. Further, the grain size of the the Surface of the fluorescent Substance layer. The light light Scattering particles is usually within the range of 0.1 Scattering length measured at the main emission wavelength tim to 1.0 lim. Examples of the light Scattering particles of the fluorescent Substance is preferably within the range of include fine particles of aluminum oxide, magnesium oxide, 5 um to 80 um, more preferably within the range of 10 tim Zinc oxide, Zinc Sulfide, titanium oxide, niobium oxide, to 70 um, and more preferably within the range of 10 um to barium Sulfate, lead carbonate, Silicon oxide, polymethyl 60 lum. The light Scattering length represents an average methacrylate, polystyrene, and melamine. distance for which light advances within a period Starting 0567 The resin material of the surface protective layer just after Scattering and ending just before next Scattering. has no particular restriction, and is preferably polyethylene The shorter the Scattering length, the higher the light Scat terephthalate, polyethylene naphthalate, polyamide, ala tering property. mide, a fluoro resin or polyester. The Surface protective layer 0562 Further, The light absorption length expressing an can be formed by dispersing the light Scattering particles in average free distance till light is absorbed is any value. a Solution containing an organic Solvent and the resin US 2005/0069827 A1 Mar. 31, 2005 55 material (binder resin) to prepare a liquid dispersion, directly 0578 A thermal development method is preferably a applying the liquid dispersion to the fluorescent Substance method using a plate heater. The thermal development layer (or to an optional auxiliary layer), and drying the method using the plate heater System is preferably a method resultant coating. Alternatively, a sheet for the protective described in JP-A No. 11-133572, in which a visible image layer formed Separately may be bonded to the fluorescent is obtained by bring a photothermographic material having Substance layer by using an adhesive. The thickness of the thereon a latent image into contact with a heating unit at the Surface protective layer is usually within the range of 2 um thermal development Zone of a thermal developing appara to 12 um, and preferably within the range of 3.5 um to 10 tus. In the thermal developing apparatus, the heating unit has plm. a plate heater and plural press rollers disposed along one Surface of the plate heater, and thermal development is 0568. Further, preferred manufacturing methods and of conducted by allowing the photothermographic material to radiation-intensifying Screens and materials used in the pass through a nip portion formed between the press rollers methods are described in detail, for example, in JP-A No. and the plate heater. It is preferable that the plate heater is 9-21899, page 6, left column, line 47 to page 8, left column, divided into 2 to 6 portions and the temperature of the top line 5, JP-A No. 6-347598, page 2, right column, line 17 to portion is set to be lower than that of the other portions by page 3, left column, line 33, and page 3, left column, line 42 around 1 C. to 10° C. to page 4, left column, line 22, and these descriptions can be referred to. 0579. Such method is also described in JP-A No. 54-30032, by which it becomes possible to remove moisture 0569. Single-Sided Photothermographic Material and an organic Solvent contained in the photothermographic 0570. The single-sided photothermographic material in material out of the System and inhibit change in the shape of the invention is particularly preferably used as an X-ray the Support caused by rapid heating of the photothermo Sensitive material for mammography. graphic material. 0571. It is important to design a single-sided photother 0580) 4-3. System mographic material used for this purpose Such that contrast 0581 An example of a medical laser imager having a of an image to be obtained is within a Suitable range. light exposure portion and a heat development portion is Fuji Medical Dry Imager FM-DPL. The imager is described 0572. As preferable configuration requirements for the in Fuji Medical Review, No. 8, pages 39-55, and techniques X-ray Sensitive material for mammography, JP-A Nos. described therein can be utilized in the invention. Further, 5-45807, 10-62881, 10-54900 and 11-109564 can be the photothermographic material can be used as a photo referred to. thermographic material for laser imagers in "AD network', 0573 Combination of Photothermographic Material and which has been proposed by Fuji Medical System as a Ultraviolet Fluorescent Screen network system that conforms to the DICOM standard. 0574 As a method for forming an image on the photo 0582 5. Applications of the Invention thermographic material of the invention, a method in which 0583. The silver halide photosensitive material and pho an image is formed by combining the Same with a fluores tothermographic material including the photographic emul cent Substance having a principal peak at 400 nm or less can Sion having a high Silver iodide content of the invention be preferably employed. A method in which an image is form a black and white image based on a Silver image and formed by combining the same with a fluorescent Substance is preferably used as a photoSensitive material for general having a principal peak at 380 nm or leSS is more preferable. purposes, a wet-type or photothermographic material for Either the double-sided photosensitive material or the medical diagnosis, or a wet-type or photothermographic Single-sided photoSensitive material may be used as an material for industrial purposes, a wet-type or photothermo assembly. AS the Screen having a principal fluorescent peak graphic material for printing, or a wet-type or photothermo at 400 nm or less, Screens described in JP-A No. 6-11804 and graphic material for COM. WO93/01521 are used, however the invention is not restricted to them. AS techniques of crossover cut (double EXAMPLES sided photosensitive material) and antihalaton (single-sided 0584 Hereinafter, the present invention will be described photosensitive material), those described in JP-A No. in detail while referring Examples, however the invention is 8-76307 can be used. As an ultraviolet absorbing dye, dyes not restricted to them. described in Japanese Patent Application No. 2000-320809 are particularly preferable. Example 1 0575) 4-2. Thermal Development 0585 1. Preparation of PET Support and Undercoat 0586 1-1. Film Formation 0576. The photothermographic material of the invention may be developed by any method, and usually the photo 0587 PET was made of terephthalic acid and ethylene thermographic material imagewise exposed is heated and glycol in an ordinary manner and had an intrinsic Viscosity developed. The development temperature is preferably from IV of 0.66 (measured in a mixture of phenol and tetrachlo 90° C. to 180° C., and more preferably from 100° C. to 140° roethane at a weight ratio of 6/4 at 25 C.). This was C. pelletized, and the resultant was dried at 130° C. for 4 hours. This pellet was colored with a blue dye, 1,4-bis(2,6,-diethy 0577. The development time is preferably from 1 sec to lanilinoanthraquinone) and the resultant was extruded out 60 sec, more preferably from 5 sec to 30 sec, and still more from a T-die, and rapidly cooled. Thus, a non-oriented film preferably from 5 sec to 20 sec. was prepared. US 2005/0069827 A1 Mar. 31, 2005 56

0588. The film was longitudinally oriented by rolls rotat 2,2'-(ethylenedithio)diethanol were added to 1421 mL of ing at different circumferencial speeds at 110° C. So that the distilled water. The resulting solution was kept at 75 C. in longitudinal length thereof after the orientation was 3.3 a Stainless Steel reaction pot while it was being Stirred. times as long as the original longitudinal length thereof. Solution A was prepared by diluting 22.22 g of Silver nitrate Next, the film was laterally oriented by a tenter at 130 C. with distilled water Such that the total volume of the result so that the lateral length thereof after the orientation was 4.5 ant mixture was 218 mL. Solution B was prepared by times as long as the original lateral length thereof. Next, the diluting 36.6 g of potassium iodide with distilled water such oriented film was thermally fixed at 240 C. for 20 seconds, that the total volume of the resultant mixture was 366 mL. and then laterally relaxed by 4% at the same temperature. These Solutions A and B were added to the content in the Next, the chuck portion of the tenter was slitted, and the both reaction pot by a controlled double jet method. At this time, edges of the film were knurled, and the film was rolled up the whole of Solution A was added at a constant flow rate at 4 kg/cm. The rolled film having a thickness of 175 um over 16 minutes. Moreover, solution B was added while pag was obtained. of the system was kept at 10.2. Then, 10 mL of a 3.5 mass % aqueous Solution of hydrogen peroxide, and 10.8 mL of 0589 1-2. Corona Processing of Surface a 10 mass % aqueous Solution of benzimidazole were added 0590 Both surfaces of this support were processed at a to the system. Solution C was prepared by diluting 51.86 g rate of 20 m/minute at room temperature by using a Solid of silver nitrate with distilled water Such that the total State corona processing machine (6 KVA model manufac volume of the resultant mixture was 508.2 mL. Moreover, tured by Pillar Company) From values of current and Solution D was prepared by diluting 63.9 g of potassium Voltage read at this time, it was found that the Support had iodide with distilled water Such that the total volume of the been processed at 0.375 kV.A.min/m. At this time, the resultant mixture was 639 mL. These solutions C and D were processing frequency was 9.6 kHz, and a gap clearance added to the system by the controlled double jet method. At between an electrode and a dielectric roll was 1.6 mm. this time, the whole of Solution C was added at a constant flow rate over 80 minutes. Moreover, Solution D was added 0591 1-3. Preparation of Undercoated Support while pag of the system was kept at 10.2. When ten minutes 0592 (1) Preparation of Coating Liquid for Undercoat had lapsed since Staring of addition of Solutions C and D, Layer potassium hexachloroiridate (III) was added to the System in an amount of 1x10" mol per mol of silver. Further, when 0593 Formulation (a) (for undercoat layer on photosen five Seconds had lapsed since completion of addition of sitive layer side) Solution C, an aqueous Solution of potassium hexacyanoiron (II) was added to the system in an amount of 3x10" molper mol of silver. 0.5 mol/L Sulfuric acid was added to the Formulation (a) for the undercoat layer System So as to adjust pH of the System at 3.8. Then Stirring on the photosensitive layer side was stopped, and precipitating/deSalting/washing Steps were Pesiresin A-520 46.8 g carried out. One mol/L sodium hydroxide was added to the (manufactured by Takamatsu Oil and Fats Co., Ltd.; System So as to adjust pH of the System at 5.9 and then a 30 mass % solution) Silver halide dispersion having pag of 11.0 was prepared. Vylonal MD-1200 10.4 g (manufactured by Toyobo Co., Ltd.) 0600 Silver halide grains in the obtained silver halide Polyethylene glycol monononyl phenyl ether 11.0 g dispersion were made of pure Silver iodide, and included (average ethylene oxide number = 8.5, 1 mass % tabular grains having an average projected area diameter of solution) MP-1OOO 0.91 g 0.93 um, a coefficient of variation of the average projected (manufactured by Soken chemical & Engineering Co., area diameter of 17.7%, an average thickness of 0.057 um, Ltd.; fine particles of PMMA polymer, and an average aspect ratio of 16.3. The entire projected area average particle size: 0.4 um) of the tabular grains corresponded to 80% or more of the Distilled water 93.1 mL. entire projected area of all the Silver halide grains. The Sphere equivalent diameter thereof was 0.42 lum. A result of 0594. Each surface of the biaxially-oriented polyethylene X-ray powder diffraction analysis showed that 90% or more terephthalate Support having a thickness of 175 um which of the Silver iodide had gamma phase. p.Ag was 10.2 when had been Subjected to the above-described corona discharge measured at 38 C. treatment was coated with the coating liquid for the under 0601 Preparation of Silver Halide Emulsion 2 coat having formulation (a) with a wire bar Such that a wet 0602 Asilver halide emulsion dispersion 2 was prepared coating amount became 6.6 ml/m (per one side). Each of the in the same manner as preparation of the Silver halide resultant coating was dried at 180° C. for 5 min. Thus, an emulsion 1 except that the addition amount of the 5 mass % undercoated Support was prepared. methanol solution of 2,2'- (ethylenedithio)diethanol was 0595 2. Formation of Coated Sample changed to 240 mL, the whole of Solution A was added over 0596) 2-1. Preparation of Coating Materials 12 minutes, the whole of Solution C was added over 64 minutes and other conditions were also Suitably changed. 0597 1) Silver Halide Emulsion The obtained silver halide emulsion grains were made of pure Silver iodide, and included tabular grains having an 0598 Preparation of Silver Halide Emulsion 1 average projected area diameter of 1.369 um, a coefficient of 0599 4.3 mL of a 1 mass % potassium iodide solution, variation of the average projected area diameter of 19.7%, 3.5 mL of 0.5 mol/L Sulfuric acid, 36.5 g of phthalated an average thickness of 0.130 um, and an average aspect gelatin and 160 mL of a 5 mass % methanol solution of ratio of 10.5. The entire projected area of the tabular grains US 2005/0069827 A1 Mar. 31, 2005 57 corresponded to 80% or more of the entire projected area of tobenzoimidazole was added to the System in an amount of all the Silver halide grains. The Sphere equivalent diameter 4.8x10 mol per mol of silver, and a methanol solution of thereof was 0.71 um. A result of X-ray powder diffraction 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole was also added analysis showed that 83% or more of the silver iodide had in an amount of 5.4x10 mol per mol of silver, and an gamma phase. aqueous Solution of 1-(3-metylureidophenyl)-5-mercap totetrazole was also add in an amount of 8.5x10 mol per 0603 Preparation Silver Halide Emulsions 3 and 4 mol of silver to prepare a silver halide emulsion 5. 0604 Preparation of Emulsions having Different Thick 0610 Silver halide dispersions 6 to 8 were prepared in neSS, Aspect Ratio and/or Sphere Equivalent Diameter the same manner as preparation of the Silver halide disper 0605 Silver halide emulsions 3 and 4 were prepared in Sion 5, except that the emulsion to be added to the reaction the same manner as preparation of the Silver halide emulsion vessel was replaced with Silver halide emulsions 2 to 4, 1 (or 2) except that the addition amount of the 5 mass % respectively. methanol solution of 2,2'-(ethylenedithio)diethanol, tem perature, pAg during formation of Silver halide, and the 0611 Preparation of Silver Halide Emulsions 9 and 10 addition rates of the Silver nitrate Solution and potassium 0612 Preparation of Emulsions for Comparison iodide solution were suitably changed. Properties of the 0613. A silver halide emulsion 9 was prepared in the obtained silver halide dispersion were as follows. The silver Same manner as preparation of the Silver halide emulsion 1 halide emulsion 3 a pure Silver iodide emulsion having an except that the temperature was changed to 45 C., pAg at average projected area of 1.43 um, a coefficient of variation the time of addition by the controlled double jet method was of the average projected area diameter of 20.1%, an average set to 9.3, and other conditions were suitably changed. The thickness of 0.24 um, an average aspect ratio of 5.95 and a obtained Silver halide emulsion grains were made of pure sphere equivalent diameter of 0.90 um. A result of X-ray Silver iodide, and included tabular grains having an average powder diffraction analysis showed that 88% or more of the projected area diameter of 1.39 um, a coefficient of variation Silver iodide had gamma phase. The Silver halide emulsion of the average projected area diameter of 20.2%, an average 4 was a pure Silver iodide emulsion having an average thickness of 0.52 um, and an average aspect ratio of 2.67. projected area of 1.422 um, a coefficient of variation of the The entire projected area of the tabular grains corresponded average projected area diameter of 20.1%, an average thick to 80% or more of the entire projected area of all the silver neSS of 0.48 um, an average aspect ratio of 2.96 and a sphere halide grains. The Sphere equivalent diameter thereof was equivalent diameter of 1.13 lum. A result of X-ray powder 1.15 lum. A result of X-ray powder diffraction analysis diffraction analysis showed that 90% or more of the silver showed that 73% or more of the silver iodide had gamma iodide had gamma phase. phase. 0606 Preparation of Silver Halide Emulsions 5 to 8 0.614. A silver halide emulsion 10 was prepared in the 0607 Preparation of Silver Bromide-Epitaxially Joined Same manner as preparation of the Silver halide dispersion 5, Grains except that the emulsion to be added to the reaction vessel 0608. The silver halide emulsion 1 was placed in a was replaced with the silver halide emulsion 9. reaction vessel in an amount which corresponded to one 0615 Preparation of Silver Halide Emulsions 1 to 10 for mole of the AgI emulsion. A 0.5 mol/L KBr solution and 0.5 Coating Liquid mol/L AgNO Solution were added to the emulsion by the double jet method over 20 minutes at 10 mL/minute to allow 0616. A 1 mass % aqueous solution of benzothiazolium substantially 10 mol % of silver bromide to epitaxially iodide was added to each of the silver halide emulsions 1 to deposit on the AgI host grains. During this operation, pAg of 10 in an amount of 7x10 mol per mol of silver. the reaction system was kept at 10.2. Further, 0.5 mol/L 0.617 Further, each of compounds 1, 2 and 3 capable of Sulfuric acid was added to the System So as to adjust pH of undergoing one-electron oxidation to form a one-electron the System at 3.8. Then Stirring was Stopped, and precipi oxidant that can release one or more electrons was added to tating/desalting/washing Steps were carried out. One mol/L each emulsion in an amount of 2x10 mol per mol of silver Sodium hydroxide was added to the System So as to adjust of silver halide. pH of the system at 5.9 and then a silver halide dispersion 0618. In addition, each of compounds 1, 2 and 3 having having pag of 11.0 was prepared. an adsorptive group and a reducing group was added to each 0609) 5 mL of a 0.34 mass % methanol solution of emulsion in an amount of 8x10 mol per mol of silver 1,2-benzoisothiazoline-3-one was added to the silver halide halide. dispersion which was kept at 38 C. and was being stirred. 0619. Furthermore, water was added to each emulsion to Forty minutes later, the temperature of the System was raised prepare a silver halide emulsion for coating liquid So that the to 47 C. When 20 minutes lapsed since increase of tem perature, a methanol Solution of Sodium benzenethiosul amount of silver of silver halide became 15.6 g per L of the fonate was added to the system in an amount of 7.6x10 Silver halide emulsion for coating liquid. mol per mol of Silver. Additional 5 minutes later, a methanol 0620) 2) Preparation of Dispersion of Silver Salt of Fatty Solution of tellurium-including Sensitizer C was added to the Acid system in an amount of 2.9x10 mol per mol of silver and then the System was aged for 91 minutes. Subsequently, 1.3 0621 Preparation of Recrystallized Behenic Acid mL of a 0.8 mass % methanol solution of N,N'-dihydroxy 0622 100 kg of behenic acid manufactured by Henkel N"N"-diethylmelamine was added to the system. Additional Co. (trade name of product: Edenor C22-85R) was dissolved 4 minutes later, a methanol Solution of 5-methyl-2-mercap in 1200 kg of isopropyl alcohol at 50° C., and the resultant US 2005/0069827 A1 Mar. 31, 2005 58

Solution was filtered through a filter having a pore size of 10 (a, b and c are defined hereinabove). An average aspect ratio lum and then cooled to 30° C. to recrystallize behenic acid. was 2.1. A coefficient of variation of Sphere equivalent The cooling rate in the recrystallization was controlled to 3 diameters of the particles was 11%. C./hour. The solution was centrifugally filtered to collect recrystallized crystals, and the crystals were washed with 0627 19.3 kg of polyvinyl alcohol (trade name, PVA 100 kg of isopropyl alcohol and then dried. The obtained 217) and water were added to the wet cake whose amount crystals were esterified and the resultant was measured by corresponded to 260 kg of the dry weight thereof so that the GC-FID. The resultant had a behenic acid content of 96 mol total amount of the resultant became 1000 kg. The resultant % and, in addition, included 2 mol % of lignoceric acid, 2 was formed into slurry with a dissolver wing, and then mol % of archidic acid and 0.001 mol % of erucic acid. pre-dispersed with a pipe-line mixer (Model PM-10 avail able from Mizuho Industry Co.). 0623) Preparation of Dispersion of Silver Salt of Fatty Acid 0628 Next, the pre-dispersed stock slurry was processed three times in a disperser (MICROFLUIDIZER M-610 0624 88 kg of recrystallized behenic acid, 422 L of obtained from Microfluidex International Corporation, and distilled water, 49.2 L of a 5 mol/Laqueous NAOH solution equipped with a Z-type interaction chamber) at a controlled and 120 L of t-butyl alcohol were mixed and reacted at 75 pressure of 1150 kg/cm. A silver behenate dispersion was C. for one hour while the resultant System was being Stirred. thus prepared. To cool it, corrugated tube type heat eXchang Thus, a sodium behenate solution B was obtained. Sepa ers were disposed before and behind the interaction cham rately, 206.2 L of an aqueous Solution (pH 4.0) containing ber. The temperature of the coolant in these heat eXchangers 40.4 kg of silver nitrate was prepared and kept at 10 C. A was So controlled that the System could be processed at a reaction vessel containing 635 L of distilled water and 30 L dispersion temperature of 18 C. of t-butyl alcohol was kept at 30° C. The entire amount of the Sodium behenate Solution and the entire amount of the 0629 3) Preparation of Reducing Agent Dispersion aqueous Solution of Silver nitrate were added to the content 0630 Preparation of of Reducing Agent-1 Dispersion of the vessel at constant flow rates over 93 minutes and 15 Seconds and over 90 minutes, respectively, while the content 0631) 10 kg of a reducing agent-1 (2,2'-methylenebis-(4- in the vessel was being Sufficiently stirred. At this time, only ethyl-6-tert-butylphenol)), 16 kg of a 10 mass % aqueous the aqueous Solution of Silver nitrate was added for 11 solution of modified polyvinyl alcohol (POVAL MP203 minutes after starting the addition of the aqueous Solution of available from Kuraray Co., Ltd.) and 10 kg of water were Silver nitrate, addition of Sodium behenate Solution was sufficiently mixed to form slurry. The slurry was fed by a Started Subsequently, and only the Sodium behenate Solution diaphragm pump into a horizontal sand mill (UVM-2 avail was added for 14 minutes and 15 Seconds after completion able from Imex Corporation) including Zirconia beads which of the addition of the aqueous Solution of Silver nitrate. At had a mean diameter of 0.5 mm, and dispersed therewith for this time, the internal temperature of the reaction vessel was 3 hours. Then, 0.2 g of sodium salt of benzoisothiazolinone kept at 30° C. The external temperature was controlled such and water were added thereto to adjust the reducing agent that the liquid temperature was constant. The pipe line for concentration of the resultant at 25% by mass. The disper the Sodium behenate Solution was a double-walled pipe and sion was heated at 60° C. for 5 hours. A reducing agent-1 thermally insulated by circulating hot water through the dispersion was thus prepared. The reducing agent particles interspace of the double-walled pipe, and the temperature of in the dispersion had a median diameter of 0.40 um, and a the solution at the outlet of the nozzle tip was adjusted at 75 maximum particles size of at most 1.4 lim. The reducing C. The pipe line for the aqueous Silver nitrate Solution was agent dispersion was filtered through a polypropylene filter also a double-walled pipe and thermally insulated by circu having a pore size of 3.0 um to remove foreign objects Such lating cold water through the interSpace of the double-walled as dirt from it, and then Stored. pipe. The position at which the Sodium behenate Solution was added to the reaction System and that at which the 0632 Preparation of Reducing Agent-2 Dispersion aqueous Silver nitrate Solution was added thereto were 0633 10 kg of a reducing agent-2 (6,6'-di-t-butyl-4,4'- disposed symmetrically relative to the shaft of the stirrer dimethyl-2,2'-butylidenediphenol), 16 kg of a 10 mass % disposed in the reactor, and the nozzle tips of the pipes were aqueous solution of modified polyvinyl alcohol (POVAL Spaced apart from the reaction Solution level in the reactor. MP203 available from Kuraray Co., Ltd.) and 10 kg of water 0625. After adding the sodium behenate solution was were sufficiently mixed to form slurry. The slurry was fed by finished, the reaction System was stirred for 20 minutes at a diaphragm pump into a horizontal sand mill (UVM-2 that temperature, and then heated to 35° C. over 30 minutes. available from Imex Corporation) including Zirconia beads Thereafter, the system was aged for 210 minutes. Immedi which had a mean diameter of 0.5 mm, and dispersed ately after completion of the ageing, the System was cen therewith for 3 hours and 30 minutes. Then, 0.2 g of sodium trifugally filtered to collect a Solid component, which was Salt of benzoisothiazolinone and water were added thereto to washed with water until the conductivity of the washing adjust the reducing agent concentration of the resultant at waste reached 30 uS/cm. The solid thus obtained was a silver 25% by mass. The dispersion was then heated at 40 C. for Salt of a fatty acid and was Stored as wet cake without drying 1 hour, and then at 80° C. for 1 hour. A reducing agent-2 it. dispersion was thus prepared. The reducing agent particles in the dispersion had a median diameter of 0.50 um, and a 0626. The shapes of the silver behenate particles obtained maximum particle size of at most 1.6 lim. The reducing herein were analyzed on the basis of their images taken agent dispersion was filtered through a polypropylene filter through electronimicroscopic photography. Average values having a pore size of 3.0 um to remove foreign objects Such of a, b, and c were 0.21 um, 0.4 um and 0.4 um, respectively as dirt from it, and then Stored. US 2005/0069827 A1 Mar. 31, 2005 59

0634) 4) Preparation of Hydrogen Bonding Compound prepare slurry. The Slurry was fed by a diaphragm pump into Dispersion a horizontal sand mill (UVM-2 available from Imex Cor 0635 Preparation of Hydrogen Bonding Compound-1 poration) including Zirconia beads which had a mean diam Dispersion eter of 0.5 mm, and dispersed therewith for 5 hours. Then, 0.2 g of Sodium Salt of benzoisothiazolinone and water were 0636) 10 kg of a hydrogen bonding compound-1 (tri(4- added thereto to prepare an organic polyhalogen com t-butylphenyl)phosphine oxide), 16 kg of a 10 mass % pound-1 dispersion having an organic polyhalogen com aqueous solution of modified polyvinyl alcohol (POVAL pound content of 30 mass %. The organic polyhalogen MP203 available from Kuraray Co., Ltd.) and 10 kg of water compound particles in the dispersion had a median diameter were sufficiently mixed to form slurry. The slurry was fed by of 0.41 um, and a maximum particle size of at most 2.0 lim. a diaphragm pump into a horizontal sand mill (UVM-2 The organic polyhalogen compound dispersion was filtered available from Imex Corporation) containing Zirconia beads through a polypropylene filter having a pore size of 10.0 um which had a mean diameter of 0.5 mm, and dispersed to remove foreign objects Such as dirt from it, and then therewith for 4 hours. Then, 0.2 g of sodium salt of ben Stored. Zoisothiazolinone and water were added thereto to adjust the 0644 Preparation of Organic Polyhalogenated Com hydrogen bonding compound concentration of the resultant pound-2 Dispersion at 25% by mass. The dispersion was heated at 40 C. for 1 hour and then at 80° C. for 1 hour. A hydrogen bonding 0.645 10 kg of an organic polyhalogen compound-2 compound-1 dispersion was thus prepared. The hydrogen (N-butyl-3-tribromomethanesulfonylbenzamide), 20 kg of a bonding compound particles in the dispersion had a median 10 mass % aqueous solution of modified polyvinyl alcohol diameter of 0.45 um, and a maximum particle size of at most (POVALMP203 available from Kuraray Co., Ltd.), and 0.4 1.3 lim. The hydrogen bonding compound dispersion was kg of a 20 mass % aqueous Solution of Sodium triisopro filtered through a polypropylene filter having a pore size of pylnaphthaleneSulfonate were Sufficiently mixed to prepare 3.0 um to remove foreign objects Such as dirt from it, and Slurry. The Slurry was fed by a diaphragm pump into a then Stored. horizontal sand mill (UVM-2 available from Imex Corpo ration) including Zirconia beads which had a mean diameter 0637 5) Preparation of Development Accelerator Disper of 0.5 mm, and dispersed therewith for 5 hours. Then, 0.2g Sion and Color-Toning Agent Dispersion of Sodium Salt of benzoisothiazolinone and water were 0638 Preparation of Development Accelerator-1 Disper added thereto to adjust the organic polyhalogen compound content of the resultant at 30 mass %. The dispersion was Sion heated at 40 C. for 5 hours. An organic polyhalogen 0639) 10 kg of a development accelerator-1, 20 kg of a 10 compound-2 dispersion was thus obtained. The organic mass % solution of modified polyvinyl alcohol (POVAL polyhalogen compound particles in the dispersion had a MP203 available from Kuraray Co., Ltd.) and 10 kg of water median diameter of 0.40 tim, and a maximum particle size were sufficiently mixed to form slurry. The slurry was fed by of at most 1.3 lim. The organic polyhalogen compound a diaphragm pump into a horizontal sand mill (UVM-2 dispersion was filtered through a polypropylene filter having available from Imex Corporation) containing Zirconia beads a pore Size of 3.0 um to remove foreign objects Such as dirt which had a mean diameter of 0.5 mm, and dispersed from it, and then Stored. therewith for 3 hours and 30 minutes. Then, 0.2 g of sodium 0646) 7) Preparation of Silver Iodide Complex-Forming Salt of benzoisothiazolinone and water were added thereto to Agent prepare a development accelerator-1 dispersion having a development accelerator concentration of 20% by mass. The 0647 8 kg of modified polyvinyl alcohol MP203 was development accelerator particles in the dispersion had a dissolved in 174.57 kg of water, and 3.15 kg of a 20 mass median diameter of 0.48 um, and a maximum particle size % aqueous Solution of Sodium triisopropylnaphthalene of at most 1.4 lim. The development accelerator dispersion sulfonate and 14.28 kg of a 70 mass % aqueous solution of was filtered through a polypropylene filter having a pore size 6-isopropylphthalazine were added to the resultant Solution of 3.0 um to remove foreign objects Such as dirt from it, and So as to prepare a 5 mass % Solution of a Silver iodide then Stored. complex-forming compound. 0640 Development accelerator-2 and color toning 0648) 8) Preparation of Mercapto Compound agent-1 Solid dispersions respectively having concentrations 0649. Preparation of Aqueous Solution of Mercapto of 20 mass % and 15 mass % were prepared in the same Compound-1 manner as the preparation of the development accelerator-1 0650 7 g of a mercapto compound-1 (sodium salt of dispersion. 1-(3-sulfophenyl)-5-mercaptotetrazole) was dissolved in 0641 6) Preparation of Polyhalogenated Compound Dis 993 g of water to form a 0.7 mass % aqueous solution. persion 0651) Preparation of Aqueous Solution of Mercapto Compound-2 0642 Preparation of Organic Polyhalogenated Com pound-1 Dispersion 0652) 20g of a mercapto compound-2 (1-(3-methylure idophenyl)-5-mercaptotetrazole) was dissolved in 980 g of 0643) 10 kg of an organic polyhalogen compound-1 water to form a 2.0 mass % aqueous Solution. (tribromomethanesulfonylbenzene), 10 kg of a 20 mass % aqueous solution of modified polyvinyl alcohol (POVAL 0653) 9) Preparation of SBR Latex Liquid MP203 available from Kuraray Co., Ltd.), 0.4 kg of a 20 0654) An SBR latex was prepared as follows. mass % aqueous Solution of Sodium triisopropylnaphthale 0655 287 g of distilled water, 7.73 g of a surfactant neSulfonate, and 14 kg of water were Sufficiently mixed to (PIONIN A-43-S produced by Takemoto Yushi Corporation US 2005/0069827 A1 Mar. 31, 2005 60 and having a solid content of 48.5 mass %), 14.06 ml of 1 and water were added to 1000 g of polyvinyl alcohol mol/liter NaOH, 0.15 g of tetrasodium ethylenediaminetet (PVA-205 available from Kuraray Co., Ltd.), and 4200 ml of raacetate, 255 g of Styrene, 11.25 g of acrylic acid, and 3.0 a 19 mass % latex of a methyl methacrylate/styrene/butyl g of tert-dodecylmercaptain were put into the polymerization acrylate/hydroxyethyl methacrylate/acrylic acid copolymer reactor of a gas monomer reaction apparatus (TAS-2J Model (copolymerization weight ratio: 64/9/20/5/2) so that the total available from Taiatsu Techno Corporation). The reactor was amount of the resultant mixture became 10000 g. The pH of sealed off, and the content therein was stirred at 200 rpm. the mixture was adjusted at 7.5 by adding NaOH to the The internal air was exhausted via a vacuum pump, and mixture. A coating liquid for intermediate layer was thus replaced a few times repeatedly with nitrogen. Then, 108.75 obtained. This was fed into a coating die So that the amount g of 1,3-butadiene was introduced into the reactor under of the coating liquid was 9.1 ml/mi. preSSure, and the internal temperature of the reactor was raised to 60° C. A solution in which 1.875 g of ammonium 0661 The viscosity of the coating liquid was 58 mPa 'S persulfate was dissolved in 50 ml of water was added to the when measured with a B-type viscometer (rotor No. 1, 60 system, and the system was stirred for 5 hour. It was further rpm) at 40° C. heated to 90° C. and stirred for 3 hours. After the reaction 0662 3) Preparation of Coating Liquid for First Surface was completed, the internal temperature was lowered to Protective Layer room temperature. Then, NaOH and NH4OH (both 1 mol/ 0663 64 g of inert gelatin was dissolved in water, and 112 liter) were added to the system at a molar ratio of Na" and g of a 19.0 mass % latex of a methyl methacrylate/styrene/ NH" of 1/5.3 so as to adjust the pH of the system at 8.4. butyl acrylate/hydroxyethyl methacrylate/acrylic acid Next, the System was filtered through a polypropylene filter copolymer (copolymerization weight ratio. 64/9/20/5/2), 30 having a pore size of 1.0 lim to remove foreign objects Such ml of a 15 mass % methanol solution of phthalic acid, 23 ml as dirt from it, and then stored. 774.7 g of SBR latex was of a 10 mass % aqueous Solution of 4-methylphthalic acid, thus obtained. Its halide ion content was measured through 28 ml of 0.5 mol/L Sulfuric acid, 5 ml of a 5 mass % aqueous ion chromatography, and the chloride ion concentration of solution of AEROSOLOT (available from American Cyana the lateX was 3 ppm. The chelating agent concentration mid Company), 0.5 g of phenoxyethanol, 0.1 g of ben thereof was measured through high-performance liquid Zoisothiazolinone, and water were added to the resultant chromatography, and was 145 ppm. Solution So that the total amount of the resultant mixture 0656. The mean particle size of the latex was 90 nm, Tg became 750 g. Just before application thereof, 26 ml of 4 thereof was 17 C., the Solid content thereof was 44% by mass % chromium alum was mixed with the mixture by mass, the equilibrium moisture content thereof at 25 C. and using a Static mixer. The resultant coating liquid was fed into 60% RH was 0.6 mass %, and the ion conductivity thereof a coating die So that the amount of the resultant coating was was 4.80 mS/cm. To measure the ion conductivity, a con 18.6 ml/mi. ductivity meter CM-30S manufactured by To a Denpa 0664) The viscosity of the coating liquid was 20 mPa 'S Kogyo K. K. was used. In the device, the 44 mass % latex when measured with a B-type viscometer (rotor No. 1, 60 was measured at 250 C. Its pH was 8.4. rpm) at 40° C. 0657 2-2. Preparation of Coating Liquid 0665 4) Preparation of Coating Liquid for Second Sur 0658) 1) Preparation of Coating Liquid-1 to -10 for face Protective Layer Image-Forming Layer 0.666 80 g of inert gelatin was dissolved in water, and 0659 The organic polyhalogen compound-2 dispersion, 102 g of a 27.5 mass % latex of a methyl methacrylate/ the organic polyhalogen compound-2 dispersion, the SBR Styrene/butyl acrylate/hydroxyethyl methacrylate/acrylic latex (Tg: 17 C.) liquid, the reducing agent-1 dispersion, the acid copolymer (copolymerization weight ratio. 64/9/20/5/ reducing agent-2 dispersion, the hydrogen bonding com 2), 5.4 ml of a 2 mass % Solution of a fluorine-containing pound-1 dispersion, the development accelerator-1 disper Surfactant (F-1), 5.4 ml of a 2 mass % aqueous Solution of Sion, the development accelerator-2 dispersion, the color a fluorine-containing surfactant (F-2), 23 ml of a 5 mass % toning agent-1 dispersion, the aqueous Solution of mercapto solution of AEROSOLOT (available from American Cyana compound-1, and the aqueous Solution of mercapto com mid Company), 4 g of fine polymethyl methacrylate par pound-2 were successively added to 1,000 g of the disper ticles (mean particle size thereof was 0.7 um and distribution sion of the silver salt of the fatty acid obtained above and of Volume-weighted average was 30%), 21 g of fine poly 276 ml of water. Then, the silver iodide complex-forming methyl methacrylate particles (mean particle size thereof agent was added to the resultant. Just before coating, each of was 3.6 um and distribution of Volume-weighted average the Silver halide emulsion-1 to -10 for coating liquid was was 60%), 1.6 g of 4-methylphthalic acid, 4.8g of phthalic added to and sufficiently mixed with the above mixture so acid, 44 ml of 0.5 mol/L Sulfuric acid, 10 mg of ben that the amount of silver of the emulsion became 0.22 mol Zoisothiazolinone, and water were added to the resultant per mol of silver salt of fatty acid. Coating liquids-1 to -10 Solution So that the total amount of the resultant mixture for the image-forming layer was thus prepared and each of became 650 g. Just before application thereof, 445 ml of an them was fed as it is to a coating die. aqueous Solution containing 4 mass % of chromium alum and 0.67 mass % of phthalic acid was mixed with the 0660 2) Preparation of Coating Liquid for Intermediate mixture by using a Static mixer. A coating liquid for the Layer 27 ml of a 5 mass % aqueous solution of AEROSOL Surface protective layer was thus obtained. The coating OT (available from American Cyanamid Company), 135 ml liquid was fed into a coating die, with its flow rate So of a 20 mass % aqueous Solution of diammonium phthalate controlled that its coating amount was 8.3 ml/m. US 2005/0069827 A1 Mar. 31, 2005

0667 The viscosity of the coating liquid was 19 mPa 'S wet-bulb temperature was 15 to 21 C). In this Zone, the when measured with a B-type viscometer (rotor No. 1, 60 coated Support to be dried was kept not in contact with the rpm) at 40° C. drier. After the drying, the support was conditioned at 25 C. 0668 2-3. Preparation of Photothermographic Material-1 and 40 to 60% RH, and then heated So that the Surface to -10 temperature was between 70 and 90° C. After the heating, the Support was cooled to have a Surface temperature of 25 0669 The coating liquid for image forming layer, the C. coating liquid for intermediate layer, the coating liquid for first Surface-protective layer, and the coating liquid for 0674) The degree of matting, in terms of the Bekk's Second Surface-protective layer were coated Simultaneously Smoothness, of the heat-developable photosensitive material thus prepared was 550 Seconds on the image forming by a slide bead coating method on the undercoat layer layer-coated Surface thereof. The pH of the image forming disposed on the Support in that order to prepare specimens layer-coated Surface of the Sample was measured and was of heat-developable photoSensitive materials. The tempera 6.O. tures of the coating liquid for image forming layer and the coating liquid for intermediate layer were controlled at 31 0675. The chemical structures of the compounds used in C., and the temperature of the coating liquid for first this Example are shown below. surface-protective layer was controlled at 36 C., and the 0676 Tellurium Sensitizer C temperature of the coating liquid for Second Surface-protec tive layer was controlled at 37 C. The coating amount of Silver, which was the Sum of the coating amount of Silver of silver salt of fatty acid and that of silver of silver halide, in one image-forming layer was 0.821 g/m. Both sides of the Support were coated according to the same formulation to form photothermographic materials-1 to -10. The photother ( )--CH CH- ) mographic materials-1 to -10 corresponded to the coating liquids-1 to -10 for image-forming layer. 0677 Compound 1 Capable of Undergoing One-Electron 0670) The coating amount (g/m) of each compound in Oxidation to Form One-Electron Oxidant that can Release one image-forming layer was as follows. One or More Electrons

Silver behemate 2.8O Polyhalogenated compound-1 O.O28 Polyhalogenated compound-2 O.O94 Silver iodide complex-forming agent O46 SBR latex 5.20 Reducing agent-1 O.33 SH N COONa Reducing agent-2 O.13 Hydrogen bonding compound-1 O.15 Development accelerator-1 O.OOS Development accelerator-2 O.O.35 N 2. Color toneing agent-1 O.OO2 N ls Mercapto compound-1 O.OO1 HS N NHSO Mercapto compound-2 O.OO3 Silver halide (in terms of Agamount) O.146 0678 Compound 2 Capable of Undergoing One-Electron Oxidation to Form One-Electron Oxidant that can Release 0671 Coating and drying conditions are shown below. One or More Electrons 0672 Before coating, the static electricity of the support was eliminated by blowing an ion blow to the support. The coating Speed was 160 m/minute. The coating and drying conditions for each Sample were controlled within the range mentioned below So that the coated Surface was Stabilized to HS – 3– the best. 0673. The distance between the coating die tip and the support was between 0.10 and 0.30 mm. The pressure in the decompression chamber was lower by 196 to 882 Pathan the C X)- NH -so atmospheric pressure. In the Subsequent chilling Zone, the NHCO coated Support was chilled with an air blow (its dry-bulb temperature was 10 to 20° C.). In the next helix type 0679 Compound 3 Capable of Undergoing One-Electron contactleSS drying Zone, the Support was dried with a dry air Oxidation to Form One-Electron Oxidant that can Release blow (its dry-bulb temperature was 23 to 45° C., and its One or More Electrons US 2005/0069827 A1 Mar. 31, 2005 62

-continued HS -K > -s; OH OH As Reducing agent-1

OH OH 0680 Compound 1 Having Adsorptive Group and Reducing Group

N-N - > Reducing agent-1 HS N SH

CH

NHCONOH

0681 Compound 2 Having Adsorptive Group and P Reducing Group | O Hydrogen bonding compound-1 OH

NHCONH NH

NX-sh SOCBr Polyhalogenated compound-1 OH

CONHC Ho 0682 Compound 3 Having Adsorptive Group and Reducing Group

SOCBr O CH Polyhalogenated compound-2

HN CH N-N N // N N N HS N N SH 2 Nf

SH SONa Mercapto compound-1 US 2005/0069827 A1 Mar. 31, 2005 63

0683 Evaluation of Photographic Performance -continued 0684) 1) Preparation 0685 Each specimen thus prepared was cut into pieces of a half-size, packaged with a packaging material mentioned below at 25 C. and 50% RH, stored at ordinary temperature for two weeks, and tested according to a test method mentioned below. 0686 Packaging Material NHCONHCH 0687. The packaging material used herein was a film including a PET film having a thickness of 10 tim, a PE film Mercapto compound-2 having a thickness of 12 um, an aluminium foil having a thickness of 9 tim, a nylon film having a thickness of 15 um, and a 3% carbon-containing polyethylene film having a thickness of 50 um, and having an oxygen permeability of 0.02 ml/atmim -0.25° C. day and a moisture permeability of OO 0.10 g/atm-m-0.25° C. day. Silver iodide complex-forming agent 0688 2) Exposure and Development 0689. The double-side-coated photosensitive material NHNHCONH prepared in this manner was evaluated as follows. 0690. The sample was sandwiched between two X-ray regular screens (HI-SCREEN B3 manufactured by Fuji Photo Film Co., Ltd., containing CaWO as a fluorescent Substance and having a peak emission wavelength of 425 nm) to form an assembly for image formation. The assembly was exposed to X-rays for 0.05 seconds and subjected to Development accelerator-1 X-ray sensitometry. The X-ray apparatus used was DRX C 3724HD (trade name) manufactured by Toshiba Corporation OH and having a tungsten target. A voltage of 80 KVp was applied to three phases with a pulse generator to generate CONH X-rays and the X-rays were made to pass through a filter of water having a thickness of 7 cm, which filter absorbed X-rays in nearly the same amount as that of X-rays which the human body absorbs, to form an X-ray source. While an X-ray exposure amount was varied by varying the distance between the assembly and the X-ray Source, the material was Development accelerator-2 exposed Stepwise at an interval of logE=0.15. After expo Sure, the material was thermally developed under the fol lowing thermal development conditions. 0691. The thermal development unit of FUJIMEDICAL DRYLASER IMAGER FM-DPL was remodeled to produce a thermal development apparatus that could heat the material from both sides thereof. Further, the apparatus was also remodeled to enable conveying a film sheet by replacing the conveying roller in the thermal development unit with a heat drum. Temperatures of four panel heaters were set to 112 C., 118°C., 120° C., and 120° C., respectively and that of oColor -dtoning agent-1 the heat drum was set to 120° C. In addition, the conveying CHCOOCH2CH2C Fo Speed was increased So that the total period of thermal development became 14 Seconds. NaOSCH1 CHCOOCH2CH2CFo 0692. On the other hand, a wet-developing type regular photosensitive material RX-U (manufactured by Fuji Photo Compound F-1 Film Co., Ltd.) was also exposed to X-rays under the same conditions and processed by using an automatic developing apparatus CEPROS-M2 (manufactured by Fuji Photo Film Co., Ltd.) and a processing liquid CE-D1 (manufactured by CHCOOCH2CHCFo Fuji Photo Film) for 45 seconds. -CHCOOCH-CH (CFCF)-H 0693), 3) Evaluation Item NaOS 0694 Sensitivity and Fogging Compound F-2 0695) The densities of the obtained images were mea Sured with a densitometer and characteristic curves of den sity relative to logarithm of the exposure amount were US 2005/0069827 A1 Mar. 31, 2005 64 depicted. The optical density of an unexposed area (Dmin Example 2 area) was defined as fogging level, and the reciprocal number of an exposure amount giving an optical density of 0707 Preparation of Fine Particle Emulsion A 1.5 was defined as Sensitivity. Results are represented by 0708 4.3 ml of a 1 mass % solution of potassium iodide, relative values given that the Sensitivity of the photosensi 3.5 ml of 0.5 mol/L Sulfuric acid and 36.7 g of phthalated tive material 1 was 100. AS for fogging level, a Smaller value gelatin were added to 1420 ml of distilled water. The is preferable. resultant solution was kept at 25 C. while it was being Image Storability Stirred in a reaction vessel made of Stainless Steel. The entire 0696) amount of solution A obtained by diluting 22.22 g of silver 0697 The printout property of the thermographic mate nitrate with distilled water so that the total amount of the rial was measured to evaluate image Storability. The image resultant became 195.6 ml and the entire amount of Solution formed above on each of the coated Samples was Stored for B obtained by diluting 21.8 g of potassium iodide with 24 hours while it was being exposed to light from a distilled water So that the total amount of the resultant fluorescent lamp having illuminance of 1000 Lux. Increase became 218 ml were added to the content of the reaction in fogging density of the Dmin area, ADmin, was obtained vessel at a constant flow rate over nine minutes. Subse and evaluated. The Smaller the ADmin value, the more quently, 10 ml of a 3.5 mass % aqueous Solution of hydrogen excellent the image Storability (printout property). peroxide and 10.8 ml of a 10 mass % aqueous solution of benzimidazole were added to the content of the reaction 0698 Haze Evaluation vessel. 0699 The Haze degree of the obtained image was visu 0709) Further, a solution C obtained by adding distilled ally and Sensorily evaluated on the basis of the following water to 51.86 g of silver nitrate so that the total amount of four Steps of evaluation Standard. the resultant became 317.5 ml and a solution D obtained by 0700 A: No white turbidity was observed. diluting 60 g of potassium iodide with distilled water so that the total amount of the resultant became 600 ml were added 0701 B: Slight white turbidity was observed. to the content of the reaction vessel by a controlled double 0702 C: Relatively much white turbidity was observed. jet method. At this time, the entire amount of the solution C turbidity was was added at a constant flow rate over 120 minutes. More 0703 D: Considerably much white over, the Solution D was added while pAg of the reaction observed. system was kept at 8.1. 0704. 4) Result 0710. Then, 0.5 mol/L sulfuric acid was added to the 0705) The obtained results are shown in Table 1. System to adjust pH of the System at 3.8, the Stirring was

TABLE 1.

Sample AgX Thickness Image No Composition (um) Sensitivity Fogging Haze Storability Remarks

1 AgI 0.057 1OO 0.17 A. O.O1 Invention 2 AgI O.13 124 O.18 A. O.O2 Invention 3 AgI O.24 112 O.18 B O.O3 Invention 4 AgI O.48 103 O.18 C O.O3 Invention 5 AgI 90, Br 10 0.057 2OO O.18 A. O.O1 Invention 6 AgI 90, Br 10 O.13 242 O.19 A. O.O2 Invention 7 AgI 90, Br 10 O.24 231 O.19 B O.O2 Invention 8 AgI 90, Br 10 O.48 221 O.19 C O.O3 Invention 9 AgI 0.52 112 O.2O D O.04 Comparative example 10 AgI 90, Br 10 0.52 212 O.2O D O.05 Comparative example RX-U - 256 O.26 A. O.O2 Comparative example

0706 From Table 1, it can be understood that the thinner Stopped and precipitation/desalting/water washing Steps the thickness of each of the Specimens of Examples, the were conducted. One mol/L Sodium hydroxide was added to better the properties thereof Such as fogging, haZe and image the system to adjust pH of the system at 5.9 and a silver Storability. Accordingly, it is understood that, in the case of halide emulsion having pAg of 8.0 was thus prepared. The photoSensitive materials having a high Silver iodide content, emulsion had an average grain size of 0.021 um, and a coefficient of variation of grain sizes of 15%. The average the photoSensitive material preferably has a thickness of no grain size was obtained by measuring the size of 1000 grains more than 0.5 tim, and more preferably a thickness of no with a transmission electron microscopy (TEM) and obtain more than 0.2 um to provide a photoSensitive material with ing the average thereof. low fogging level, low haze level and excellent image Storability. In addition, it is also understood that Sensitivity 0711 Preparation of Silver Halide Emulsion 21 is further improved by providing epitaxial join for tabular 0712 8.0 ml of a 10 mass % solution of potassium iodide, grains. 3.5 ml of 0.5 mol/L Sulfuric acid, 9.2 g of phthalated gelatin US 2005/0069827 A1 Mar. 31, 2005

and 160 ml of a 5 mass % methanol Solution of 2,2'- corresponded to 98% or more of the entire projected area of (ethylene dithio) diethanol were added to 1421 ml of dis all the Silver halide grains. The Sphere equivalent diameter tilled water. The resultant solution was kept at 75 C. while thereof was 0.7 um. A result of X-ray powder diffraction is was being Stirred in a reaction vessel made of StainleSS analysis showed that 60% or more of the silver iodide had Steel. The entire amount of a Solution A obtained by diluting beta phase. p.Ag was 10.2 when measured at 38 C. 3.2 g of silver nitrate with distilled water so that the total amount of the resultant became 32 ml and the entire amount 0719 Preparation of Silver Halide 23 of a Solution B obtained by diluting 3.2 g of potassium 0720) 8.0 ml of a 10 mass % solution of potassium iodide, iodide with distilled water so that the total amount of the 3.5 ml of 0.5 mol/L Sulfuric acid, 4.2 g of phthalated gelatin resultant became 32 ml were added to the content of the and 160 ml of a 5 mass % methanol Solution of 2,2'- reaction vessel at a constant flow rate over one minute. (ethylene dithio) diethanol were added to 1421 ml of dis Subsequently, 10 ml of a 3.5 mass % aqueous solution of tilled water. The resultant solution was kept at 75 C. while hydrogen peroxide and 10.8 ml of a 10 mass % aqueous it was being Stirred in a reaction vessel made of Stainless Solution of benzimidazole were added to the content (reac Steel. The entire amount of a Solution A obtained by diluting tion System) of the reaction vessel, and the resultant mixture 22.22 g of silver nitrate with distilled water so that the total was kept for 16 minutes. amount of the resultant became 218 ml and a solution B obtained by diluting 36.6 g of potassium iodide with distilled 0713 Subsequently, the fine particulate emulsion A, the water So that the total amount of the resultant became 366 ml amount of which corresponded to 0.42 mol of silver, was were added to the system by a controlled double jet method. added to the System at a constant flow rate over 260 minutes. At this time, the Solution A was added at a constant flow rate When 100 minutes had lapsed since starting of the addition over 16 minutes. Moreover, the Solution B was added while of the fine particle emulsion A, potassium hexachloroiridate pAg of the System was kept at 10.2. Subsequently, 10 ml of (III) was added to the system in an amount of 1x10" molper a 3.5 mass % aqueous Solution of hydrogen peroxide and mol of silver. Further, when 5 seconds had lapsed since 10.8 ml of a 10 mass % aqueous solution of benzimidazole completion of the addition of the fine particle emulsion A, an were added to the System. aqueous Solution of potassium iron (II)hexacyanide (II) was added to the system in an amount of 3x10" per mol of 0721 Further, the entire amount of a solution C obtained silver. 0.5 mol/L Sulfuric acid was added to the system to by diluting 51.86 g of silver nitrate with distilled water so adjust pH of the System at 3.8, Stirring was stopped, and that the total amount of the resultant became 508.2 ml and precipitation/desalting/water washing steps were conducted. the entire amount of a solution D obtained by diluting 63.9 g of potassium iodide with distilled water so that the total One mol/L Sodium hydroxide was added to the system to amount of the resultant became 639 ml were added to the adjust pH of the system at 5.9, and a silver halide emulsion system by a controlled double jet method. At this time, the 21 having pag of 11.0 was thus obtained. Solution C was added at a constant flow rate over 80 minutes. 0714. The obtained silver halide grains contained in the Moreover, the solution D was added while pag of the silver halide emulsion 21 were made of pure silver iodide, System was kept at 10.2. When ten minutes had lapsed since and included tabular grains having an average projected area the starting of the addition of the solution C and the solution diameter of 2.4 tim, a coefficient of variation of the average D, potassium hexachloroiridate (III) was added to the Sys projected area diameter of 19.4%, an average thickness of tem in an amount of 1x10" mol per mol of silver. 0.04 um, and an average aspect ratio of 60.0. The entire 0722 Further, when five seconds had lapsed since projected area of the tabular grains corresponded to 97% or completion of the addition of the Solution C, an aqueous more of the entire projected area of all the silver halide Solution of potassium iron (II9 hexacyanide was added to the grains. The Sphere equivalent diameter thereof was 0.7 um. system in an amount of 3x10" mol per mol of silver. 0.5 A result of X-ray powder diffraction analysis showed that mol/L Sulfuric acid was added to the system to adjust pH of 70% or more of the silver iodide had beta phase. p Ag was the System at 3.8, Stirring was stopped, and precipitation/ 10.2 when measured at 38 C. deSalting/water washing Steps were conducted. Then, one 0715 Preparation of Fine Particle Emulsion B mol/L Sodium hydroxide was added to the System to adjust pH of the system at 5.9, and a silver halide emulsion 23 0716 A fine particle emulsion B was obtained in the having pag of 11.0 was thus prepared. Same manner as preparation of the fine particle emulsion A 0723. The obtained silver halide grains contained in the except that the temperature during grain formation was kept silver halide emulsion 23 were made of pure silver iodide, at 42 C. The emulsion had an average grain size of 0.040 and included tabular grains having an average projected area tim and a coefficient of variation of grain sizes of 11%. diameter of 1.38 um, a coefficient of variation of the average 0717 Preparation of Silver Halide Emulsion 22 projected area diameter of 16.6%, an average thickness of 0.12 um, and an average aspect ratio of 11.5. The entire 0718. A silver halide emulsion 22 was obtained in the projected area of the tabular grains corresponded to 90% or Same manner as preparation of the Silver halide emulsion 21 more of the entire projected area of all the silver halide except that the fine particle emulsion A was replaced with grains. The Sphere equivalent diameter thereof was 0.7 um. the fine particle emulsion B. The obtained silver halide A result of X-ray powder diffraction analysis showed that grains contained in the Silver halide emulsion 22 were made 50% or more of the Silver iodide had gamma phase. pAg was of pure Silver iodide, and included tabular grains having an 10.2 when measured at 38 C. average projected area diameter of 2.16 um, a coefficient of variation of the average projected area diameter of 18.2%, 0724 Preparation of Silver Halide Emulsion 24 an average thickness of 0.049 um, and an average aspect 0725 3.5 ml of 0.5 mol/L Sulfuric acid, 2.3 g of phtha ratio of 44.0. The entire projected area of the tabular grains lated gelatin and 20 ml of a 5 mass % methanol solution of US 2005/0069827 A1 Mar. 31, 2005 66

2,2'-(ethylene dithio)diethanol were added to 1421 ml of 0731 Photothermographic materials 21 to 28 were manu distilled water. The resultant solution was kept at 75 C. factured in the Same manner as in Example 1 except that the while is was being Stirred in a reaction vessel made of silver halide emulsions 21 to 28 were respectively used. The Stainless Steel. The entire amount of a Solution A obtained by photographic performance of each of the photothermo diluting 22.22 g of silver nitrate with distilled water so that the total amount of the resultant became 218 ml and a graphic materials was evaluated in the same manner as in solution B obtained by diluting 36.6 g of potassium iodide Example 1, except that a reducing agent-3 and a nucleus with distilled water So that the total amount of the resultant forming agent were used as follows. became 366 ml were added to the system by a controlled 0732) The total coating amount (g/m) of each compound double jet method. At this time, the solution A was added at a constant flow rate over 16 minutes. Moreover, the Solution in one image forming layer is as follows. B was added while pAg of the System was kept at 7.2. Subsequently, 10 ml of a 3.5 mass % aqueous solution of hydrogen peroxide and 10.8 ml of a 10 mass % aqueous Silver salt of fatty acid 2.85 Solution of benzimidazole were added to the System. Polyhalogen compound-1 O.O28 0726 Further, the entire amount of a solution C obtained Polyhalogen compound-2 O.O94 by diluting 51.86 g of silver nitrate with distilled water so Silver iodide complex-forming agent O46 that the total amount of the resultant became 508.2 ml and SBR latex 5.20 the entire amount of a solution D obtained by diluting 63.9 Reducing agent-3 O46 g of potassium iodide with distilled water so that the total Nucleus forming agent-1 O.036 amount of the resultant became 639 ml were added to the Hydrogen bonding compound-1 O.15 Development accelerator-1 O.OOS system by a controlled double jet method. At this time, the Development accelerator-2 O.O.35 Solution C was added at a constant flow rate over 80 minutes. Color toning agent-1 O.OO2 Moreover, the solution D was added while pag of the Mercapto compound-1 O.OO1 System was kept at 7.2. Mercapto compound-2 O.OO3 0727. When ten minutes had lapsed since the starting of Silver of Silver halide 0.175 the addition of the solution C and the solution D, potassium hexachloroiridate (III) was added to the System in an amount of 1x10" mol per mol of silver. Further, when five seconds 0733 Preparation of Dispersion of Nucleus Forming had lapsed since completion of the addition of the Solution C, an aqueous Solution of potassium iron (II)hexacyanide Agent was added to the system in an amount of 3x10" mol per mol 0734) 2.5g of polyvinyl alcohol (PVA-217 manufactured of silver. 0.5 mol/L Sulfuric acid was added to the system so as to adjust pH of the System at 3.8, Stirring was Stopped, and by Kuraray Co., Ltd.) and 87.5g of water were added to 10 precipitation/deSalting/water washing Steps were conducted. g of a nucleus forming agent SH-7, and the resultant mixture One mol/L Sodium hydroxide was added to the System So as was sufficiently stirred to form slurry. The slurry was left to to adjust pH of the system at 5.9, and a silver halide stand for three hours. The slurry and 240 g of zirconia beads emulsion 24 having pag of 11.0 was thus prepared. having a diameter of 0.5 mm were placed in a vessel and the resultant was stirred for 10 hours by a disperser (4 G sand 0728. The obtained silver halide grains contained in the silver halide emulsion 24 were made of pure silver iodide, grinder mill manufactured by Imex Company) to prepare a and included tabular grains having an average projected area Solid fine particle dispersion of the nucleus forming agent. diameter of 0.67 um, a coefficient of variation of the average 80 mass % of the particles had a grain size of 0.1 to 1.0 lim projected area diameter of 23.2%, an average thickness of and the average grain size was 0.5 lim. 0.51 um, and an average aspect ratio of 1.3. The entire projected area of the tabular grains corresponded to 80% or more of the entire projected area of all the silver halide Reducing agent- 3. grains. The Sphere equivalent diameter thereof was 0.7 um. A result of X-ray powder diffraction analysis showed that 70% or more of the Silver iodide had gamma phase. pAg was 10.2 when measured at 38 C.

0729) Preparation of Silver Bromochloride-Epitaxially OH OH Joined Particles 0730 Silver bromide epitaxial emulsions 25 to 28 were prepared in the same manner as preparation of the Silver halide emulsion 5 in Example 1 except that the silver halide emulsions 21 to 24 were respectively used, that the 0.5 mol/L KBr Solution was replaced with a Solution containing 0.35 mol of KBr and 0.15 mol of NaCl, that pAg of the System was kept at 6.7 during the double jet addition, and that the addition time was changed to 40 minutes to epi 0735 Table 2 shows obtained results. The sensitivity of taxially precipitate substantially 20 mol % of silver bromo each Sample was expressed as a relative Sensitivity given chloride on AgI host grains contained in the emulsion. that the sensitivity the specimen 24 was 100. US 2005/0069827 A1 Mar. 31, 2005 67

TABLE 2 Sphere equiv. Specimen AgX diameter Thickness Image No. Composition (um) (um) Sensitivity Fogging Haze storability Remarks 21 AgI 0.70 O.04 106 O.18 A. 0.02 Invention 22 AgI 0.70 O.049 121 O.18 A. 0.03 Invention 23 AgI 0.70 O.12 135 O.2 A. 0.04 Invention 24 AgI 0.70 O.51 1OO O.21 D 0.06 Comp. Example 25 AgoDBrio O.74 O.04 403 O.19 A 0.02 Invention 26 AgoDBrio O.74 O.049 472 O.19 A 0.02 Invention 27 AgoDBrio O.74 O.12 512 O.21 B 0.03 Invention 28 AgoDBrio O.74 O.51 265 O.23 D 0.06 Comp. Example

0736. It was found from Table 2 that, as the thickness of fluorescent Substance layer was peeled off from the provi the planer particles is reduced, the properties Such as Sen Sional Support to form a fluorescent Substance sheet. Sitivity, fogging, haZe and image Storability are improved, as in Example 1. Accordingly, it was found that, in the case of 0743) 3) Provision of Fluorescent Substance Sheet on photoSensitive materials having a high Silver iodide content, Light Reflection Layer the photoSensitive material preferably has a thickness of no more than 0.5 tim, and more preferably a thickness of no 0744. The fluorescent Substance sheet was put on the more than 0.2 um to provide a photoSensitive material with Surface of the light reflection layer disposed on the Support low fogging level, low haze level and excellent image and manufactured in step 1), the resultant was pressed by a storability. In addition, it was also found that sensitivity is calendar roll under a pressure of 400 kgw/cm at 80° C. to further improved by providing epitaxial join for tabular dispose the fluorescent Substance layer on the light reflection grains. layer. The thickness of the fluorescent Substance layer was 125 um and the volume filling rate of the fluorescent 0737. In particular, it was found that, when the percent particles was 68%. age of tabular grains in the emulsion having a high Silver iodide content is high (the entire projected area of grains 0745) 4) Formation of Surface Protective Layer having an aspect ratio of 2 or more corresponds to 80% or more of the entire projected area of all the tabular grains), 0746. A polyester adhesive was applied to one surface of and when mono-dispersibility of the emulsion is Satisfactory a polyethylene terephthalate (PET) film having a thickness (coefficient of variation of 25% or less), sensitivity is of 6 um, and the resultant was bonded to the fluorescent especially high. Substance layer by a lamination method So as to form a Surface protective layer. A fluorescence intensifying Screen Example 3 A having the Support, the light reflection layer, the fluores cent Substance layer and the Surface protection layer was 0738 1. Preparation of Fluorescent Intensifying Screen thus obtained. 0739 1) Preparation of Undercoat Layer 0747 5) Light Emitting Characteristics 0740 Alight reflection layer made of an alumina powder and having a dry thickness of 50 um was formed on a 0748 FIG. 1 shows an emission spectrum of an intensi Support made of polyethylene terephthalate and having a fying Screen A measured by using X-rays at 40 kVp. The thickness of 250 um in the same manner as in Example 2 of fluorescent intensifying Screen Ashowed emission having a JP-ANO. 2001-124898. peak at 390 nm and narrow half breadth. 0741) 2) Preparation of Fluorescent Substance Sheet 0749 2. Evaluation of Performance 0742 250 g of BaFBr:Eu fluorescent substance (average 0750 Evaluation was made in the same manner as in grain size: 3.5 um), 8 g of a polyurethane binder resin Example 2 except that the Specimens of Example 2 were (Pandex T5265M (trade name) manufactured by Dai Nippon used and that the Screen used at the time of exposure was Ink and Chemicals Incorporated), 2 g of an epoxy binder replaced with the intensifying Screen A. As a result, excel resin (Epicoat 1001 (trade name) manufactured by Yuka lent images were obtained by using the Specimen of the Shell Epoxy Co.) and 0.5 g of an isocyanate compound invention, as in Example 2. (Colonate HX (trade name) manufactured by Nippon Poly urethane Industry Co., Ltd.) were added to methyl ethyl Example 4 ketone, and the resultant mixture was stirred by a propeller 0751 1. Preparation of Fluorescent Intensifying Screen mixer to prepare a coating liquid for forming a fluorescent substance layer having a viscosity of 25 PS at 25 C. The 0752 Fluorescent intensifying screens C, D and E were coating Solution was coated on a Surface of a provisional manufactured in the same manner as preparation of the Support (a polyethylene terephthalate sheet previously fluorescent Screen A except that the coating amount of the coated with a silicone releasing agent), and the resultant fluorescent Substance coating liquid was changed. Table 3 coating was dried to form a fluorescent Substance layer. The shows the thickness of the fluorescent Substance layer and US 2005/0069827 A1 Mar. 31, 2005 68 the volume filling rate of the fluorescent substance in the System. Thereafter, a Solution C was prepared by diluting obtained fluorescent intensifying Screen. 51.86 g of silver nitrate with distilled water so that the total amount of the resultant became 508.2 mL, and a solution D TABLE 3 was prepared by diluting 63.9 g of potassium iodide with Fluorescent Thickness of distilled water So that the total amount of the resultant intensifying Fluorescent fluorescent Volume filling rate of SCCC substance substance layer fluorescent substance became 639 mL. The entire amount of the Solution C and the A. BaFBr:Ell 125 um 68% entire amount of the solution D were added to the system by C BaFBr:Ell 70 um 70% a controlled double jet method. At this time, the solution C D BaFBr:Ell 160 um 66% was added at a constant flow rate over 160 minutes. More E BaFBr:Ell 250 um 64% over, the Solution D was added while pAg of the System was kept at 10.2. When 20 minutes had lapsed since the starting 0753 2. Evaluation for Performances of the addition of the solutions C and D, potassium 0754 Each of the photothermographic materials used in hexachloroiridate (III) was added to the System in an amount Example 3 was exposed to X-rays in the same manner as in of 1x10" mol per mol of silver. Further, when five seconds Example 3 except that the fluorescent intensifying Screen A had lapsed since completion of the addition of the Solution was replaced with each combination of Screens described C, an aqueous Solution of potassium iron (II)hexacyanide below. The front Screen herein is a Screen disposed nearer to was added to the system in an amount of 3x10" molper mol the X-ray Source than the photothermographic material, and of silver. 0.5 mol/L Sulfuric acid was added to the system so the back Screen is a Screen disposed farther from the X-ray as to adjust pH of the System at 3.8. Then, Stirring was Source than the photothermographic material. Stopped, and precipitating/desalting/washing Steps were car 0755. As in Example 3, preferred results were obtained ried out. One mol/L Sodium hydroxide was added to the by using the Specimens of the invention. System So as to adjust pH of the System at 5.9, and a Silver halide dispersion having pag of 11.0 was thus prepared. TABLE 4 0759 Silver halide grains in the obtained silver halide Front screen Back screen dispersion were made of pure Silver iodide, and included A. A. C C tabular grains having an average projected area diameter of C A. 0.86 um, a coefficient of variation of the average projected C D C E area diameter of 17.7%, an average thickness of 0.045 um, A. E and an average aspect ratio of 19.1. The entire projected area of the tabular grains corresponded to 80% or more of the entire projected area of all the Silver halide grains. The Example 5 sphere equivalent diameter thereof was 0.37 lum. A result of 0756 1. Preparation of Photosensitive Silver Halide X-ray powder diffraction analysis showed that 90% or more Emulsion of the Silver iodide had gamma phase. 0757 1) Preparation of Silver Halide Emulsion 1" 0760) 2) Preparation of Silver Halide Emulsions 2 to 6' 0758, 4.3 mL of a 1 mass % potassium iodide solution, 0761 Silver halide emulsions 2 to 4" having different 3.5 mL of 0.5 mol/L Sulfuric acid, 36.5 g of phthalated average thickness different were prepared in the same man gelatin and 160 mL of a 5 mass % methanol solution of ner as preparation of Silver halide emulsion 1' except that 2,2'-(ethylenedithio)diethanol were added to 1421 mL of temperature in the reaction vessel, pAg at at the time of distilled water. The resulting solution was kept at 75 C. in addition of the solutions C and D, and pH in the reaction a reaction vessel made of Stainless Steel while it was being vessel were Suitably changed. The Silver halide grains in Stirred. Separately, a Solution A was prepared by diluting each of the resultant Silver halide emulsions were made of 22.22 g of silver nitrate with distilled water so that the total amount of the resultant became 218 mL, and a Solution B pure Silver iodide. The sizes of the grains in each of the was prepared by diluting 36.6 g of potassium iodide with emulsions are shown in Table 5. Further, silver halide distilled water So that the total amount of the resultant emulsions 5' and 6' respectively having an average thickness became 366 mL. The entire amount of the Solution A and the of 0.080 um and 0.177 um were prepared in the same entire amount of the Solution B were added to the reaction manner as preparation of the Silver halide emulsion 1' except system by a controlled double jet method. At this time, the that temperature in the reaction vessel, pag at the time of Solution A was added at a constant flow rate over 32 minutes. addition of the solutions C and D, and pH in the reaction Moreover, the solution B was added while pag of the system vessel were Suitably changed. The Silver halide grains in was kept at 10.2. Then, 10 mL of a 3.5 mass % aqueous each of the resultant Silver halide emulsions were made of solution of hydrogen peroxide, and 10.8 mL of a 10 mass % pure silver iodide. The Sizes of the grains in each of the aqueous Solution of benzimidazole were further added to the emulsions are also shown in Table 5. US 2005/0069827 A1 Mar. 31, 2005 69

TABLE 5 Average Projected Average Average Sphere Emulsion Composition Area Diameter Thickness equivalent Diameter No (mole ratio) (um) (um) Aspect Ratio (um) Remarks 1" AgI 90, Br 10 O.86 O.O45 19.1 O.37 The invention 2 AgI 90, Br 10 O.93 0.057 16.3 O.42 The invention 3' AgI 90, Br 10 1.08 O140 7.7 O.63 The invention 4' AgI 90, Br 10 1.11 0.155 7.1 O.66 The invention 5 AgI 90, Br 10 1.12 O.O8O 14.O O.53 Comparative example 6" AgI 90, Br 10 1.15 O.177 6.5 0.71 Comparative example

Example 6 The resultant mixture was stirred for 2 hours while it was 0762. 1. Preparation of Support kept at 70° C. A wet cake of the dye was thus prepared. The wet cake of the dye contained 1 mol of methanol and 2 mol 0763) 1) Undercoat of water with respect to mol of the dye. In confirmation of 0764. Each surface of a biaxially oriented, blue-colored the composition, a part of the wet cake was dried at room (1,4-bis(2,6-diethylanilinoanthraquinone)-containing) poly temperature. Then, H-NMR measurement was conducted ethylene terephthalate Support having a thickness of 175 um and thereby presence of methanol in the crystal could be was Subjected to corona discharge treatment, and coated confirmed. Moreover, a Karl-Fisher titration method was with respective coating liquids for a first undercoat layer and also conducted and presence of crystallization water could a Second undercoat layer containing following main com be confirmed. Further, it was also confirmed that, when the ponents in this order by using a wire bar coater. crystal was heated at 150° C., methanol and crystallization water in the crystal were released. From these results, Solid 0765) First Undercoat Layer (Support Side) concentration of the dye in the wet cake was found to be 50 0766 The amount of the coating liquid was set at 4.9 mL mass %. per m of each side of the Support. The coating amounts of 0776 Method for Preparing Fine particle Aqueous Dis respective materials per m of each side of the Support were persion of Wet Cake as follows. 0777. The dye in the form of wet cake was treated as a wet cake without being dried and weighed 3.0 g thereof as a solid dye. Water for dispersion was previously mixed with Styrene-butadiene copolymer latex 0.31 g (in terms of solid content) 1.2 g of a 25 mass % Solution of a dispersing agent, Demol 2,4-dichloro-6-hydroxy-s-triazine sodium 8 mg SNB (manufactured by Kao Corporation), and the weighed dye was added to the resultant Solution. Additional water was added to the resulting dispersion So that the total weight 0767 The coated support was dried at 190° C. of the resultant became 30 g. Then the resultant was suffi ciently stirred to form slurry. 120 g of zirconia beads were 0768) Second Undercoat layer prepared and the slurry and the beads were put into a vessel. 0769 The amount of the coating liquid was set at 7.9 mL Then, the slurry and the beads were stirred with a sand per m of each side of the Support. The coating amounts of grinder mill of /16 gallon (manufactured by Imex Corpora respective materials per m of each side of the Support were tion) at a rotational speed of 1500 rpm while the vessel was as follows. cooled with water. The Zirconia beads had an average particle diameter of 1 mm and the Stirring was performed for 8 hours. After completion of the Stirring, water was added to the resultant dispersion So that the Solid content of the dye Gelatin 80 mg in the dispersion became 5 mass %. Then, a desired disper CHsO(CH2CH2O)oH 1.8 mg Antiseptic agent D 0.27 mg Sion liquid was obtained. Matting agent 2.5 mg 0778 Method for Preparing Coating Liquid for Dye Layer 0770 (polymethyl methacrylate particles having an aver 0779 Compounds were added to a water mother liquor in age particle size of 2.5 um) the following order So as to obtain the following coating 0771) The coated support was dried at 185° C. amounts. The coating amounts of the respective compounds are those per m of one side of the Support. 0772) 2. Preparation of Coated Sample 0773) 1) Preparation of Coating Liquid for Dye Layer 0774 Preparation of Wet Cake of Dye for Crossover Cut Gelatin 0.47 g Fine particle aqueous dispersion 8.4 mg 0775 Dye A (solid content 10 g) was added to a mixed of wet cake (in terms of solid content of dye) solvent containing 150 mL of methanol and 50 mL of water. US 2005/0069827 A1 Mar. 31, 2005 70

mol per mol of Silver. Additional 5 minutes later, a methanol -continued Solution of tellurium-including Sensitizer C was added to the Sodium polystyrenesulfonate 10 mg system in an amount of 2.9x10 mol per mol of silver and (average molecular weight: 600000) then the System was aged for 91 minutes. Subsequently, 1.3 Compound A-1 5 mg mL of a 0.8 mass % methanol solution of N,N'-dihydroxy Antiseptic agent D 1 mg N"N"-diethylmelamine was added to the system. Additional 4 minutes later, a methanol Solution of 5-methyl-2-mercap 0780. At this time, a small amount of acetic acid or tobenzoimidazole was added to the System in an amount of Sodium hydroxide was added to the resultant coating liquid 4.8x10 mol per mol of silver, and a methanol solution of So as to adjust pH of the coating liquid at 6.0. 1-phenyl-2-heptyl-5-mercapto-1,3,4 -triazole was also added in an amount of 5.4x10 mol per mol of silver, and an aqueous Solution of 1-(3-metylureidophenyl)-5-mercap Dye A totetrazole was also add in an amount of 8.5x10 mol per CH CH-CHECH-CHCH CH W mol of silver to prepare a silver halide emulsion 7". 0785 Silver halide grains in the obtained silver halide N dispersion were grains having a high Silver iodide content RX HO N and containing 10 mol % of silver bromide, and included tabular grains having an average projected area diameter of 0.86 um, a coefficient of variation of the average projected area diameter of 17.7%, an average thickness of 0.045 Om, and an average aspect ratio of 19.1. The entire projected area of the tabular grains corresponded to 80% or more of the OCOOH COOH Compound A-1 entire projected area of all the Silver halide grains. The sphere equivalent diameter thereof was 0.37 lum. A result of X-ray powder diffraction analysis showed that 90% or more call-( )-to-a-cursors of the Silver iodide had gamma phase. Antiseptic agent D 0786 Preparation of Coating Liquid for Photosensitive S N Layer NH 0787. The following components were added to the silver halide emulsion So as to obtain the following coating O amounts. The coating amounts are those per m of one side of the Support. 0781) 2) Preparation of Silver Halide Photosensitive Layer Coating amount of silver 1.8g Gelatin 1.7g 0782 Preparation of Photosensitive Silver Halide Emul Dextran 428 mg Sion (average molecular weight: 39000) Sodium polystyrenesulfonate 40 mg 0783 The silver halide emulsion 1' of Example 5 was (average molecular weight: 600000) Compound A-2 204 mg placed in a reaction vessel in an amount of one mole. A 0.5 Compound A-3 2.2 mg mol/L KBr solution and 0.5 mol/L AgNO, solution were Compound A-4 0.5 mg added to the emulsion by the double jet method over 20 Compound A-5 2.8 mg minutes at 10 mL/minute to allow substantially 10 mol% of 1.2-Bis(vinylsulfonylaceatmide)ethane 50 mg Silver bromide to epitaxially deposit on the AgI host grains. A-2 During this operation, p Ag of the reaction System was kept OH at 10.2. Further, 0.5 mol/L Sulfuric acid was added to the System So as to adjust pH of the System at 3.8. Then Stirring was stopped, and precipitating/deSalting/washing Steps were carried out. One mol/L sodium hydroxide was added to the System So as to adjust pH of the System at 5.9 and then a SONa Silver halide dispersion having pag of 11.0 was prepared. OH A-3 0784 Five mL of a 0.34 mass % methanol solution of HOHN N NHOH 1,2-benzoisothiazoline-3-one was added to the silver halide dispersion which was kept at 38 C. and was being stirred. Forty minutes later, the temperature of the System was raised to 47 C. When 20 minutes lapsed since increase of tem perature, a methanol Solution of Sodium benzenethiosul fonate was added to the system in an amount of 7.6x10 US 2005/0069827 A1 Mar. 31, 2005 71

-continued Matting agent-1 A-4 e th th N -(-CH-C- (-CH-CH-) (CH-C), NX-sh COCH CO2H

A-5 A-6 O O C8H17 O-CH-CH2-), SO-Na 2 CH ( OCH A-7 C18H33O -- CH2CH2O - H st st A-8 SO SOHN(C2H5)3 C17H3CONCH2CHSONa Dye-1 CH C2H5 A-9 CH7 O NH F--CF-SON-(-CHCHO-H A-10 CH7 C2H5 F-(-CFSON-(-CHCHO-1 (-CH-) SO-Na C2H5 A-11 N1 NN O NH | SH NN N

CHs

0788 3) Preparation of Coating Liquid for Surface Pro tective Layer COONa 0789. The following compounds were mixed so as to A-12 obtain the following coating amounts. 0790 Coating amounts of compounds per m of one side of Support 0792) 4) Coating of Sample Gelatin 0.767 g 0793 Both sides of the undercoated Support were simul Sodium polyacrylate 80 mg taneously coated with the coating liquid for dye layer, the (average molecular weight: 400000) coating liquid for Silver halide photoSensitive layer and the Sodium polystyrenesulfonate 1.1 mg (average molecular weight: 600000) coating liquid for Surface protective layer by a simultaneous Matting agent-1 (in terms of solid content) 70 mg extrusion method in that order, and the resultant coatings (average particle size: 3.7 um) were dried. The amounts of the coating liquid for the dye Compound A-6 18.1 mg layer, that for the photoSensitive layer, and that for the Compound A-7 34.5 mg Compound A-8 6.8 mg surface protective layer were 12.4 mL, 45.2 mL, and 10.7 Compound A-9 3.2 mg mL per m of one side of the Support, respectively. Compound A-10 1.4 mg Compound A-11 2.1 mg 0794) 3. Evaluation Compound A-12 1.0 mg Antiseptic agent D 0.9 mg 0795) 1) Exposure and Development p-Benzoquinone 0.7 mg 0796. The double-sided photosensitive material thus pre pared was evaluated as follows. 0791) At this time, a small amount of sodium hydroxide 0797 The sample was sandwiched between two X-ray was added to the coating liquid for Surface protective layer regular screens (HI-SCREEN B3 manufactured by Fuji So as to adjust pH of the coating liquid at 6.8. Photo Film Co., Ltd., containing CaWO as a fluorescent US 2005/0069827 A1 Mar. 31, 2005 72

Substance and having a peak emission wavelength of 425 regular screens (HI-SCREEN B3 manufactured by Fuji nm) to form an assembly for image formation. The assembly Photo Film Co., Ltd., containing CaWO as a fluorescent was exposed to X-rays for 0.05 Seconds and Subjected to Substance and having a peak emission wavelength of 425 X-ray sensitometry. The X-ray apparatus used was DRX nm), and the resultant assembly was arranged in position. 3724HD (trade name) manufactured by Toshiba Corporation The X-ray vessel was DRX-3724HD (trade name) manu and having a tungsten target. Voltage of 80 KVp was applied factured by Toshiba Corporation and using a tungsten target. to three phases with a pulse generator to generate X-rays and A focal spot size was set at 0.6 mmx0.6 mm. X-rays were the X-rays were made to pass through a filter of water having generated through 3 mm thick aluminum equivalent material a thickness of 7 cm, which filter absorbed X-rays in nearly including a diaphragm. A Voltage of 80 KV was applied to the same amount as that of X-rays which the human body three phases with a pulse generator to generate X-rays and absorbs, to form an X-ray source. While an X-ray exposure the X-rays were made to pass through a filter of water having amount was varied by varying the distance between the a thickness of 7 cm, which filter absorbed X-rays in nearly assembly and the X-ray Source, the material was exposed the same amount as that of X-rays which the human body Stepwise at an interval of logE=0.15. After exposure, the absorbs, to form an X-ray Source. After exposure, the material was thermally developed by using an automatic material was thermally developed by using an automatic developing apparatus, CEPROS-M2 (manufactured by Fuji developing apparatus, CEPROS-M2 (manufactured by Fuji Photo Film Co., Ltd.), and a developer solution, CE-D1 Photo Film Co., Ltd.), and a developer solution, CE-D1 (manufactured by Fuji Photo Film), for 5 minutes. (manufactured by Fuji Photo Film), for 5 minutes. The exposure amount at the time of X-ray photography was 0798) 2) Evaluation Item adjusted So that the average of the highest and lowest 0799. The densities of the obtained images were mea densities of the developed image would be 1.0. Sured with a densitometer and characteristic curves of den sity relative to logarithm of the exposure amount were 0805 Subsequently, the sample to be measured was pro depicted. The optical density of an unexposed area (Dmin cessed with a microdensitometer. At this time, density area) was defined as fogging level. AS for fogging level, a profile was measured at a Sampling interval of 30 um by Smaller value is preferable. using, as an aperture, a slit having a length of 30 um in the operating direction and a length of 500 um in a direction 0800 Image Storability perpendicular to the operating direction. This procedure was 0801. The image formed above on each of the coated repeated twenty times and the obtained values were aver Samples was Stored for 24 hours while it was being exposed aged to obtain a density profile on which CTF calculation to light from a fluorescent lamp having illuminance of 1000 was based. Thereafter, the peak of the rectangular wave for Lux. Increase in fogging density of the Dmin area, ADmin, each frequency in the density profile was detected and was obtained and evaluated. A Smaller value means a lower density contrast for each frequency was calculated. The printout level, which Stands for more excellent image measured values with respect to a spatial frequency of 2 storability. lp/mm are shown in Table 6. 0802 Measurement of Sharpness 0806) 3) Evaluation Result 0803 Contrast transfer function (CTF) was measured to 0807. The obtained results are shown in Table 6. evaluate Sharpness. 0808 AS can be easily recognized from the data shown in 0804 MRE single-sided photographic material (manu Table 6, a photographic material that is exposed to light in factured by Eastman Kodak Co.) was brought into contact a Specific range of a spectrum can have improved CTF with an intensifying Screen to be measured, and a rectan response when the thickness of the Silver halide grains are gular chart (made of molybdenum, and having a thickness of Selected Such that light reflection level in the wavelength 80 um and a spatial frequency of 0 lp/mm to 10 lp/mm) for range becomes minimum. Further, as for absolute properties MTF measurement was photographed. The chart was placed of the material, it was confirmed that the material has at a position which was 2 m away from an X-ray vessel. The Sharpness equal to that of prevailing photosensitive materi photographic material was Sandwiched between two X-ray als.

TABLE 6 Average Average Average Sphere Emulsion Composition Projected Area Thickness Aspect equivalent Diameter Image Sharpness No (mole ratio) Diameter (um) (um) Ratio (um) Fogging Storability 2 lp/mm Remarks 1. AgI 90, Br 10 O.86 O.O45 19.1 O.368 0.17 O.O1 0.323 The invention 2 AgI 90, Br 10 O.93 0.057 16.3 O42O 0.17 O.O1 0.291. The invention 3' AgI 90, Br 10 1.08 O140 7.7 O626 O.18 O.O1 0.301 The invention 4' AgI 90, Br 10 1.11 0.155 7.2 O.659 O.18 O.O1 0.282 The invention 5 AgI 90, Br 10 1.12 O.O8O 14.O O.532 O.18 O.O1 0.203 Comparative example 6 AgI 90, Br 10 1.15 O.177 6.5 O.705 O.18 O.O1 0.186 Comparative example RX-U - 0.17 O.O1 0.289 Comparative example US 2005/0069827 A1 Mar. 31, 2005 73

Example 7 treatment was coated with the coating liquid for the under coat having formulation (a) with a wire bar Such that a wet 0809) 1. Preparation of PET Support and Undercoat coating amount became 6.6 ml/m (per one side). Each of the 0810 1-1. Film Formation resultant coatings was dried at 180° C. for 5 min. Thus, an undercoated Support was prepared. 0811 PET was made of terephthalic acid and ethylene glycol in an ordinary manner and had an intrinsic Viscosity 0819 2. Preparation of Materials for Coating IV of 0.66 (measured in a mixture of phenol and tetrachlo 0820) 1) Silver Halide Emulsion roethane at a weight ratio of 6/4 at 25 C.). This was pelletized, and the resultant was dried at 130 C. for 4 hours. 0821 Preparation of Silver Halide Emulsions 1' to 6' for This pellet was colored with a blue dye, 1,4-bis(2,6,-diethy Coating Liquid lanilinoanthraquinone) and the resultant was extruded out 0822. As silver halide emulsions, the silver halide emul from a T-die, and rapidly cooled. Thus, a non-oriented film Sions 1' to 6' prepared in Example 6 were used. was prepared. 0823. 2) Preparation of Dispersion of Fatty Acid Silver 0812. The film was longitudinally oriented by rolls rotat Salt ing at different circumferencial speeds at 110° C. So that the longitudinal length thereof after the orientation was 3.3 0824 Preparation of Recrystallized Behenic Acid times as long as the original longitudinal length thereof. 0825 100 kg of behenic acid manufactured by Henkel Next, the film was laterally oriented by a tenter at 130 C. Co. (trade name of product: Edenor C22-85R) was dissolved so that the lateral length thereof after the orientation was 4.5 in 1200 kg of isopropyl alcohol at 50° C., and the resultant times as long as the original lateral length thereof. Next, the Solution was filtered through a filter having a pore size of 10 oriented film was thermally fixed at 240 C. for 20 seconds, lum and then cooled to 30° C. to recrystallize behenic acid. and then laterally relaxed by 4% at the same temperature. The cooling rate in the recrystallization was controlled to 3 Next, the chuck portion of the tenter was slitted, and the both C./hour. The solution was centrifugally filtered to collect edges of the film were knurled, and the film was rolled up recrystallized crystals, and the crystals were washed with at 4 kg/cm°. The rolled film having a thickness of 175 um 100 kg of isopropyl alcohol and then dried. The obtained was obtained. crystals were esterified and the resultant was measured by 0813 1-2. Corona Processing of Surface GC-FID. The resultant had a behenic acid content of 96 mol % and, in addition, included 2 mol % of lignoceric acid, 2 0814 Both surfaces of this support were processed at a mol % of archidic acid and 0.001 mol % of erucic acid. rate of 20 m/minute at room temperature by using a Solid State corona processing machine (6 KVA model manufac 0826 Preparation of Dispersion of Silver Salt of Fatty tured by Pillar Company). From values of current and Acid Voltage read at this time, it was found that the Support had 0827) 88 kg of recrystallized behenic acid, 422 L of been processed at 0.375 kV.A.min/m. At this time, the distilled water, 49.2 L of a 5 mol/Laqueous NAOH solution processing frequency was 9.6 kHz, and a gap clearance and 120 L of t-butyl alcohol were mixed and reacted at 75 between an electrode and a dielectric roll was 1.6 mm. C. for one hour while the resultant System was being Stirred. Thus, a sodium behenate solution B was obtained. Sepa 0815 1-3. Preparation of Undercoated Support rately, 206.2 L of an aqueous Solution (pH 4.0) containing 0816 (1) Preparation of Coating Liquid for Undercoat 40.4 kg of silver nitrate was prepared and kept at 10° C. A Layer reaction vessel containing 635 L of distilled water and 30 L of t-butyl alcohol was kept at 30° C. The entire amount of 0817 Formulation (a) (for undercoat layer on photosen the Sodium behenate Solution and the entire amount of the Sitive layer side) aqueous Solution of Silver nitrate were added to the content of the vessel at constant flow rates over 93 minutes and 15 Seconds and over 90 minutes, respectively, while the content Formulation (a) (for undercoat layer in the vessel was being Sufficiently stirred. At this time, only on photosensitive layer side) the aqueous Solution of Silver nitrate was added for 11 Pesiresin A-520 46.8 g minutes after Starting the addition of the aqueous Solution of (manufactured by Takamatsu Oil and Fats Co., Ltd.; Silver nitrate, addition of Sodium behenate Solution was 30 mass % solution) Started Subsequently, and only the Sodium behenate Solution Vylonal MD-1200 10.4 g was added for 14 minutes and 15 Seconds after completion (manufactured by Toyobo Co., Ltd.) Polyethylene glycol monononyl phenyl ether 11.0 g of the addition of the aqueous Solution of Silver nitrate. At (average ethylene oxide number = 8.5, 1 mass % this time, the internal temperature of the reaction vessel was solution) kept at 30° C. The external temperature was controlled such MP-1OOO 0.91 g that the liquid temperature was constant. The pipe line for (manufactured by Soken chemical & Engineering Co., Ltd.; fine particles of PMMA polymer, the Sodium behenate Solution was a double-walled pipe and average particle size: 0.4 um) thermally insulated by circulating hot water through the Distilled water 93.1 mL. interspace of the double-walled pipe, and the temperature of the solution at the outlet of the nozzle tip was adjusted at 75 C. The pipe line for the aqueous Silver nitrate Solution was 0818. Each surface of the biaxially-oriented polyethylene also a double-walled pipe and thermally insulated by circu terephthalate Support having a thickness of 175 um which lating cold water through the interSpace of the double-walled had been Subjected to the above-described corona discharge pipe. The position at which the Sodium behenate Solution US 2005/0069827 A1 Mar. 31, 2005 74 was added to the reaction System and that at which the 0835 Preparation of Reducing Agent-2 Dispersion aqueous Silver nitrate Solution was added thereto were 0836) 10 kg of a reducing agent-2 (6,6'-di-t-butyl-4,4'- disposed symmetrically relative to the shaft of the stirrer dimethyl-2,2'-butylidenediphenol), 16 kg of a 10 mass % disposed in the reactor, and the nozzle tips of the pipes were aqueous solution of modified polyvinyl alcohol (POVAL Spaced apart from the reaction Solution level in the reactor. MP203 available from Kuraray Co., Ltd.) and 10 kg of water were sufficiently mixed to form slurry. The slurry was fed by 0828. After adding the sodium behenate solution was a diaphragm pump into a horizontal sand mill (UVM-2 finished, the reaction System was stirred for 20 minutes at available from Imex Corporation) including Zirconia beads that temperature, and then heated to 35° C. over 30 minutes. which had a mean diameter of 0.5 mm, and dispersed Thereafter, the system was aged for 210 minutes. Immedi therewith for 3 hours and 30 minutes. Then, 0.2 g of sodium ately after completion of the ageing, the System was cen Salt of benzoisothiazolinone and water were added thereto to trifugally filtered to collect a Solid component, which was adjust the reducing agent concentration of the resultant at washed with water until the conductivity of the washing 25% by mass. The dispersion was then heated at 40 C. for waste reached 30 uS/cm. The solid thus obtained was a silver 1 hour, and then at 80° C. for 1 hour. A reducing agent-2 Salt of a fatty acid and was Stored as wet cake without drying dispersion was thus prepared. The reducing agent particles it. in the dispersion had a median diameter of 0.50 um, and a maximum particle size of at most 1.6 lim. The reducing 0829. The shapes of the silver behenate particles obtained agent dispersion was filtered through a polypropylene filter herein were analyzed on the basis of their images taken having a pore size of 3.0 um to remove foreign objects Such through electronimicroscopic photography. Average values as dirt from it, and then Stored. of a, b, and c were 0.21 um, 0.4 um and 0.4 um, respectively (a, b and c are defined hereinabove). An average aspect ratio 0837 4) Preparation of Hydrogen Bonding Compound was 2.1. A coefficient of variation of Sphere equivalent Dispersion diameters of the particles was 11%. 0838 Preparation of Hydrogen Bonding Compound-1 Dispersion 0830) 19.3 kg of polyvinyl alcohol (trade name, PVA 217) and water were added to the wet cake whose amount 0839) 10 kg of a hydrogen bonding compound-1 (tri(4- corresponded to 260 kg of the dry weight thereof so that the t-butylphenyl)phosphine oxide), 16 kg of a 10 mass % total amount of the resultant became 1000 kg. The resultant aqueous solution of modified polyvinyl alcohol (POVAL was formed into slurry with a dissolver wing, and then MP203 available from Kuraray Co., Ltd.) and 10 kg of water pre-dispersed with a pipe-line mixer (Model PM-10 avail were sufficiently mixed to form slurry. The slurry was fed by able from Mizuho Industry Co.). a diaphragm pump into a horizontal sand mill (UVM-2 available from Imex Corporation) containing Zirconia beads 0831 Next, the pre-dispersed stock slurry was processed which had a mean diameter of 0.5 mm, and dispersed three times in a disperser (MICROFLUIDIZER M-610 therewith for 4 hours. Then, 0.2 g of sodium salt of ben obtained from Microfluidex International Corporation, and Zoisothiazolinone and water were added thereto to adjust the equipped with a Z-type interaction chamber) at a controlled hydrogen bonding compound concentration of the resultant pressure of 1150 kg/cm. A silver behenate dispersion was at 25% by mass. The dispersion was heated at 40 C. for 1 thus prepared. To cool it, corrugated tube type heat eXchang hour and then at 80° C. for 1 hour. A hydrogen bonding ers were disposed before and behind the interaction cham compound-1 dispersion was thus prepared. The hydrogen ber. The temperature of the coolant in these heat eXchangers bonding compound particles in the dispersion had a median was So controlled that the System could be processed at a diameter of 0.45 um, and a maximum particle size of at most dispersion temperature of 18 C. 1.3 lum. The hydrogen bonding compound dispersion was filtered through a polypropylene filter having a pore size of 0832 3) Preparation of Reducing Agent Dispersion 3.0 um to remove foreign objects Such as dirt from it, and 0833 Preparation of of Reducing Agent-1 Dispersion then Stored. 0840 5) Preparation of Development Accelerator Disper 0834 10 kg of a reducing agent-1 (2,2'-methylenebis-(4 Sion and Color-Toning Agent Dispersion -ethyl-6-tert-butylphenol)), 16 kg of a 10 mass % aqueous solution of modified polyvinyl alcohol (POVAL MP203 0841 Preparation of Development Accelerator-1 Disper available from Kuraray Co., Ltd.) and 10 kg of water were Sion sufficiently mixed to form slurry. The slurry was fed by a 0842) 10 kg of a development accelerator-1, 20 kg of a 10 diaphragm pump into a horizontal sand mill (UVM-2 avail mass % solution of modified polyvinyl alcohol (POVAL able from Imex Corporation) including Zirconia beads which MP203 available from Kuraray Co., Ltd.) and 10 kg of water had a mean diameter of 0.5 mm, and dispersed therewith for were sufficiently mixed to form slurry. The slurry was fed by 3 hours. Then, 0.2 g of sodium salt of benzoisothiazolinone a diaphragm pump into a horizontal sand mill (UVM-2 and water were added thereto to adjust the reducing agent available from Imex Corporation) containing Zirconia beads concentration of the resultant at 25% by mass. The disper which had a mean diameter of 0.5 mm, and dispersed sion was heated at 60° C. for 5 hours. A reducing agent-1 therewith for 3 hours and 30 minutes. Then, 0.2 g of sodium dispersion was thus prepared. The reducing agent particles Salt of benzoisothiazolinone and water were added thereto to in the dispersion had a median diameter of 0.40 um, and a prepare a development accelerator-1 dispersion having a maximum particles size of at most 1.4 lim. The reducing development accelerator concentration of 20% by mass. The agent dispersion was filtered through a polypropylene filter development accelerator particles in the dispersion had a having a pore size of 3.0 um to remove foreign objects Such median diameter of 0.48 um, and a maximum particle size as dirt from it, and then Stored. of at most 1.4 lim. The development accelerator dispersion US 2005/0069827 A1 Mar. 31, 2005 75 was filtered through a polypropylene filter having a pore size 0850) 7) Preparation of Silver Iodide Complex-Forming of 3.0 um to remove foreign objects Such as dirt from it, and Agent then Stored. 0851 8 kg of modified polyvinyl alcohol MP203 was 0843 Preparation of Development Accelerator-2 Disper dissolved in 174.57 kg of water, and 3.15 kg of a 20 mass Sion and Color Toning Agent-1 Solid Dispersion % aqueous Solution of Sodium triisopropylnaphthalene sulfonate and 14.28 kg of a 70 mass % aqueous solution of 0844 Development accelerator-2 and color toning 6-isopropylphthalazine were added to the resultant Solution agent-1 Solid dispersions respectively having concentrations So as to prepare a 5 mass % Solution of a Silver iodide of 20 mass % and 15 mass % were prepared in the same complex-forming compound. manner as the preparation of the development accelerator-1 0852) 8) Preparation of Mercapto Compound dispersion. 0853 Preparation of Aqueous Solution of Mercapto 0845 6) Preparation of Polyhalogenated Compound Dis Compound-1 persion 0854 7 g of a mercapto compound-1 (1-(3-sulfophenyl)- 0846 Preparation of Organic Polyhalogenated Com 5-mercaptotetrazole sodium salt) was dissolved in 993 g of pound-1 Dispersion water to form a 0.7 mass % aqueous Solution. 0847 10 kg of an organic polyhalogen compound-i (tri 0855 Preparation of Aqueous Solution of Mercapto bromomethanesulfonylbenzene), 10 kg of a 20 mass % Compound-2 aqueous solution of modified polyvinyl alcohol (POVAL 0856 20g of a mercapto compound-2 (1-(3-methylure MP203 available from Kuraray Co., Ltd.), 0.4 kg of a 20 idophenyl)-5-mercaptotetrazole) was dissolved in 980 g of mass % aqueous Solution of Sodium triisopropylnaphthale water to form a 2.0 mass % aqueous Solution. neSulfonate, and 14 kg of water were Sufficiently mixed to prepare slurry. The Slurry was fed by a diaphragm pump into 0857) 9) Preparation of SBR Latex Liquid a horizontal sand mill (UVM-2 available from Imex Cor 0858. An SBR latex was prepared as follows. poration) including Zirconia beads which had a mean diam 0859 287 g of distilled water, 7.73 g of a surfactant eter of 0.5 mm, and dispersed therewith for 5 hours. Then, (PIONIN A-43-S produced by Takemoto Yushi Corporation 0.2 g of sodium salt of benzoisothiazolinone and water were and having a solid content of 48.5 mass %), 14.06 ml of 1 added thereto to prepare an organic polyhalogen com mol/liter NaOH, 0.15 g of tetrasodium ethylenediaminetet pound-1 dispersion having an organic polyhalogen com raacetate, 255 g of Styrene, 11.25 g of acrylic acid, and 3.0 pound content of 30 mass %. The organic polyhalogen g of tert-dodecylmercaptain were put into the polymerization compound particles in the dispersion had a median diameter reactor of a gas monomer reaction apparatus (TAS-2J Model of 0.41 um, and a maximum particle size of at most 2.0 lim. available from Taiatsu Techno Corporation). The reactor was The organic polyhalogen compound dispersion was filtered sealed off, and the content therein was stirred at 200 rpm. through a polypropylene filter having a pore size of 10.0 um The internal air was exhausted via a vacuum pump, and to remove foreign objects Such as dirt from it, and then replaced a few times repeatedly with nitrogen. Then, 108.75 Stored. g of 1,3-butadiene was introduced into the reactor under preSSure, and the internal temperature of the reactor was 0848 Preparation of Organic Polyhalogenated Com raised to 60° C. A solution in which 1.875 g of ammonium pound-2 Dispersion persulfate was dissolved in 50 ml of water was added to the system, and the system was stirred for 5 hour. It was further 0849) 10 kg of an organic polyhalogen compound-2 heated to 90° C. and stirred for 3 hours. After the reaction (N-butyl-3-tribromomethanesulfonylbenzamide), 20 kg of a was completed, the internal temperature was lowered to 10 mass % aqueous solution of modified polyvinyl alcohol room temperature. Then, NaOH and NHOH (both 1 mol/ (POVALMP203 available from Kuraray Co., Ltd.), and 0.4 liter) were added to the system at a molar ratio of Na" and kg of a 20 mass % aqueous Solution of Sodium triisopro NH of 1/5.3 so as to adjust the pH of the system at 8.4. pylnaphthaleneSulfonate were Sufficiently mixed to prepare Next, the System was filtered through a polypropylene filter Slurry. The slurry was fed by a diaphragm pump into a having a pore size of 1.0 um to remove foreign objects Such horizontal sand mill (UVM-2 available from Imex Corpo as dirt from it, and then stored. 774.7 g of SBR latex was ration) including Zirconia beads which had a mean diameter thus obtained. Its halide ion content was measured through of 0.5 mm, and dispersed therewith for 5 hours. Then, 0.2g ion chromatography, and the chloride ion concentration of of Sodium Salt of benzoisothiazolinone and water were the lateX was 3 ppm. The chelating agent concentration added thereto to adjust the organic polyhalogen compound thereof was measured through high-performance liquid content of the resultant at 30 mass %. The dispersion was chromatography, and was 145 ppm. heated at 40 C. for 5 hours. An organic polyhalogen 0860. The mean particle size of the latex was 90 nm, Tg compound-2 dispersion was thus obtained. The organic thereof was 17 C., the solid content thereof was 44% by polyhalogen compound particles in the dispersion had a mass, the equilibrium moisture content thereof at 25 C. and median diameter of 0.40 tim, and a maximum particle size 60% RH was 0.6 mass %, and the ion conductivity thereof of at most 1.3 lim. The organic polyhalogen compound was 4.80 mS/cm. To measure the ion conductivity, a con dispersion was filtered through a polypropylene filter having ductivity meter CM-30S manufactured by To a Denpa a pore Size of 3.0 um to remove foreign objects Such as dirt Kogyo K. K. was used. In the device, the 44 mass % latex from it, and then Stored. was measured at 25 C. Its pH was 8.4. US 2005/0069827 A1 Mar. 31, 2005 76

0861) 2-2. Preparation of Coating Liquid 0870 4) Preparation of Coating Liquid for Second Sur 0862) 1) Preparation of Coating Liquid-1' to -10' for face Protective Layer Image-Forming Layer 0871 80 g of inert gelatin was dissolved in water, and 0863. The organic polyhalogen compound-1 dispersion, 102 g of a 27.5 mass % latex of a methyl methacrylate/ the organic polyhalogen compound-2 dispersion, the SBR Styrene/butyl acrylate/hydroxyethyl methacrylate/acrylic latex (Tg: 17 C.) liquid, the reducing agent-1 dispersion, the acid copolymer (copolymerization weight ratio. 64/9/20/5/ reducing agent-2 dispersion, the hydrogen bonding com 2), 5.4 ml of a 2 mass % Solution of a fluorine-containing pound-1 dispersion, the development accelerator-1 disper Surfactant (F-1), 5.4 ml of a 2 mass % aqueous Solution of Sion, the development accelerator-2 dispersion, the color a fluorine-containing surfactant (F-2), 23 ml of a 5 mass % toning agent-1 dispersion, the aqueous Solution of mercapto solution of AEROSOLOT (available from American Cyana compound-1, and the aqueous Solution of mercapto com mid Company), 4 g of fine polymethyl methacrylate par pound-2 were successively added to 1,000 g of the disper ticles (mean particle size thereof was 0.7 um and distribution sion of the silver salt of the fatty acid obtained above and of Volume-weighted average was 30%), 21 g of fine poly 276 ml of water. Then, the silver iodide complex-forming methyl methacrylate particles (mean particle size thereof agent was added to the resultant. Just before coating, each of was 3.6 um and distribution of Volume-weighted average the silver halide emulsion-1" to -10' for coating liquid was was 60%), 1.6 g of 4-methylphthalic acid, 4.8g of phthalic added to and sufficiently mixed with the above mixture so acid, 44 ml of 0.5 mol/L Sulfuric acid, 10 mg of ben that the amount of silver of the emulsion became 0.22 mol Zoisothiazolinone, and water were added to the resultant Solution So that the total amount of the resultant mixture per mol of silver salt of fatty acid. Coating liquids-1' to -10' became 650 g. Just before application thereof, 445 ml of an for the image-forming layer was thus prepared and each of aqueous Solution containing 4 mass % of chromium alum them was fed as it is to a coating die. and 0.67 mass % of phthalic acid was mixed with the 0864. 2) Preparation of Coating Liquid for Intermediate mixture by using a Static mixer. A coating liquid for the Layer Surface protective layer was thus obtained. The coating 0865 27 ml of a 5 mass % aqueous solution of AERO liquid was fed into a coating die, with its flow rate So SOL OT (available from American Cyanamid Company), controlled that its coating amount was 8.3 ml/m. 135 ml of a 20 mass % aqueous solution of diammonium 0872 The viscosity of the coating liquid was 19 mPa 'S phthalate and water were added to 1000 g of polyvinyl when measured with a B-type viscometer (rotor No. 1, 60 alcohol (PVA-205 available from Kuraray Co., Ltd.), and rpm) at 40° C. 4200 ml of a 19 mass % latex of a methyl methacrylate/ Styrene/butyl acrylate/hydroxyethyl methacrylate/acrylic 0873 4. Formation of Photothermographic Material-1' to acid copolymer (copolymerization weight ratio. 64/9/20/5/ -10' 2) So that the total amount of the resultant mixture became 0874. The coating liquid for image forming layer, the 10000 g. The pH of the mixture was adjusted at 7.5 by coating liquid for intermediate layer, the coating liquid for adding NaOH to the mixture. A coating liquid for interme first Surface-protective layer, and the coating liquid for diate layer was thus obtained. This was fed into a coating die Second Surface-protective layer were coated Simultaneously so that the amount of the coating liquid was 9.1 ml/mi. by a slide bead coating method on the undercoat layer disposed on the Support in that order to prepare specimens 0866 The viscosity of the coating liquid was 58 mPa 'S of heat-developable photoSensitive materials. The tempera when measured with a B-type viscometer (rotor No. 1, 60 tures of the coating liquid for image forming layer and the rpm) at 40° C. coating liquid for intermediate layer were controlled at 31 0867 3) Preparation of Coating Liquid for First Surface C., and the temperature of the coating liquid for first Protective Layer surface-protective layer was controlled at 36 C., and the temperature of the coating liquid for Second Surface-protec 0868 64 g of inert gelatin was dissolved in water, and 112 tive layer was controlled at 37 C. The coating amount of g of a 19.0 mass % latex of a methyl methacrylate/styrene/ Silver, which was the Sum of the coating amount of Silver of butyl acrylate/hydroxyethyl methacrylate/acrylic acid silver salt of fatty acid and that of silver of silver halide, in copolymer (copolymerization weight ratio. 64/9/20/5/2), 30 one image-forming layer was 0.821 g/m. Both sides of the ml of a 15 mass % methanol solution of phthalic acid, 23 ml Support were coated according to the Same formulation to of a 10 mass % aqueous Solution of 4-methylphthalic acid, form photothermographic materials-1' to -10'. The photo 28 ml of 0.5 mol/L Sulfuric acid, 5 ml of a 5 mass % aqueous solution of AEROSOLOT (available from American Cyana thermographic materials-1' to -10' corresponded to the coat mid Company), 0.5 g of phenoxyethanol, 0.1 g of ben ing liquids-1' to -10' for image-forming layer. Zoisothiazolinone, and water were added to the resultant 0875) The coating amount (g/m) of each compound in Solution So that the total amount of the resultant mixture one image-forming layer was as follows. became 750 g. Just before application thereof, 26 ml of 4 mass % chromium alum was mixed with the mixture by using a Static mixer. The resultant coating liquid was fed into Silver behemate 2.8O a coating die So that the amount of the resultant coating was Polyhalogenated compound-1 O.O28 18.6 ml/mi. Polyhalogenated compound-2 O.O94 Silver iodide complex-forming agent O46 0869. The viscosity of the coating liquid was 20 mPa-S SBR latex 5.20 when measured with a B-type viscometer (rotor No. 1, 60 Reducing agent-1 O.33 rpm) at 40° C. US 2005/0069827 A1 Mar. 31, 2005 77

0887. 2) Exposure and Development -continued 0888. The double-side-coated photosensitive material Reducing agent-2 O.13 prepared in this manner was evaluated as follows. Hydrogen bonding compound-1 O.15 Development accelerator-1 O.OOS 0889. The sample was sandwiched between two X-ray Development accelerator-2 O.O.35 regular screens (HI-SCREEN B3manufactured by Fuji Color toning agent-1 O.OO2 Photo Film Co., Ltd., containing CaWO as a fluorescent Mercapto compound-1 O.OO1 Mercapto compound-2 O.OO3 Substance and having a peak emission wavelength of 425 Silver halide (in terms of Ag) O.146 nm) to form an assembly for image formation. The assembly was exposed to X-rays for 0.05 seconds and subjected to X-ray sensitometry. The X-ray apparatus used was DRX 3724HD (trade name) manufactured by Toshiba Corporation 0876 Coating and drying conditions are shown below. and having a tungsten target. A voltage of 80 KVp was 0877. Before coating, the static electricity of the support applied to three phases with a pulse generator to generate was eliminated by blowing an ion blow to the support. The X-rays and the X-rays were made to pass through a filter of coating Speed was 160 m/minute. The coating and drying water having a thickness of 7 cm, which filter absorbed conditions for each Sample were controlled within the range X-rays in nearly the same amount as that of X-rays which mentioned below So that the coated Surface was Stabilized to the human body absorbs, to form an X-ray source. While an the best. X-ray exposure amount was varied by varying the distance 0878 The distance between the coating die tip and the between the assembly and the X-ray Source, the material was support was between 0.10 and 0.30 mm. The pressure in the exposed Stepwise at an interval of logE=0.15. After expo decompression chamber was lower by 196 to 882 Pathan the Sure, the material was thermally developed under the fol atmospheric pressure. In the Subsequent chilling Zone, the lowing thermal development conditions. coated Support was chilled with an air blow (its dry-bulb 0890. The thermal development unit of FUJIMEDICAL temperature was 10 to 20° C.). In the next helix type DRYLASER IMAGER FM-DPL was remodeled to produce contactleSS drying Zone, the Support was dried with a dry air a thermal development apparatus that could heat the material blow (its dry-bulb temperature was 23 to 45° C., and its from both sides thereof. Further, the apparatus was also wet-bulb temperature was 15 to 21 C.). In this Zone, the remodeled to enable conveying a film sheet by replacing the coated Support to be dried was kept not in contact with the conveying roller in the thermal development unit with a heat drier. drum. Temperatures of four panel heaters were set to 112 C., 118°C., 120° C., and 120° C., respectively and that of 0879. After the drying, the support was conditioned at the heat drum was set to 120° C. In addition, the conveying 25 C. and 40 to 60% RH, and then heated so that the surface Speed was increased So that the total period of thermal temperature was between 70 and 90° C. After the heating, development became 14 Seconds. the Support was cooled to have a Surface temperature of 25 C. 0891. On the other hand, a wet-developing type regular photosensitive material RX-U (manufactured by Fuji Photo 0880. The degree of matting, in terms of the Bekk's Film Co., Ltd.) was also exposed to X-rays under the same Smoothness, of the heat-developable photosensitive material conditions and processed by using an automatic developing thus prepared was 550 Seconds on the image forming apparatus CEPROS-M2 (manufactured by Fuji Photo Film layer-coated Surface thereof, and 130 Seconds on the back Co., Ltd.) and a processing liquid CE-D1 (manufactured by layer. The pH of the image forming layer-coated Surface of Fuji Photo Film) for 45 seconds. the Sample was measured and was 6.0. 0892 3) Evaluation Item 0881. The chemical structure of each compound used in 0893 Sensitivity and Fogging this Example is as illustrated previously. 0894. The densities of the obtained images were mea 0882 4. Evaluation of Performance Sured with a densitometer and characteristic curves of den sity relative to logarithm of the exposure amount were 0883) 1) Preparation depicted. The optical density of an unexposed area (Dmin 0884. Each specimen thus prepared was cut into pieces of area) was defined as fogging level. AS for fogging level, a a half-size, packaged with a packaging material mentioned Smaller value is preferable. below at 25 C. and 50% RH, stored at ordinary temperature 0895) Image Storability for two weeks, and tested according to a test method 0896. The image formed above on each of the coated mentioned below. Samples was Stored for 24 hours while it was being exposed 0885 Packaging Material to light from a fluorescent lamp having illuminance of 1000 Lux. Increase in fogging density of the Dmin area, ADmin, 0886. The packaging material used herein was a film was obtained and evaluated. A Smaller value means a lower including a PET film having a thickness of 10 tim, a PE film printout level, which Stands for more excellent image having a thickness of 12 um, an aluminium foil having a storability. thickness of 9 tim, a nylon film having a thickness of 15 um, and a 3% carbon-containing polyethylene film having a 0897 Measurement of Sharpness thickness of 50 um, and having an oxygen permeability of 0898 Contrast transfer function (CTF) was measured to 0.02 ml/atmm°-25 C. day and a moisture permeability of evaluate Sharpness. MRE single-sided photographic mate 0.10 g/atm-m°-25° C. day. rial (manufactured by Eastman Kodak Co.) was brought into US 2005/0069827 A1 Mar. 31, 2005 78 contact with an intensifying Screen to be measured, and a a Specific range of a spectrum can have improved CTF rectangular chart (made of molybdenum, and having a response when the thickness of the Silver halide grains are thickness of 80 um and a spatial frequency of 0 lp/mm to 10 Selected Such that light reflection level in the wavelength lp/mm) for MTF measurement was photographed. The chart was placed at a position which was 2 m away from an X-ray range becomes minimum. Further, as for absolute properties vessel. The photographic material was Sandwiched between of the material, it was confirmed that the material has two X-ray regular screens (HI-SCREEN B3 manufactured Sharpness equal to that of prevailing photosensitive materi by Fuji Photo Film Co., Ltd., containing CaWO as a als.

TABLE 7 Average Average Average Sphere Emulsion Composition Projected Area Thickness Aspect equivalent Diameter Image Sharpness No (mole ratio) Diameter (um) (um) Ratio (um) Fogging Storability 2 lp/mm Remarks 1. AgI 90, Br 10 O.86 O.O45 19.1 O.368 0.17 O.O1 0.302 The invention 2 AgI 90, Br 10 O.93 0.057 16.3 O42O 0.17 O.O1 0.284 The invention 3' AgI 90, Br 10 1.08 O140 7.7 O626 O.18 O.O1 0.288 The invention 4' AgI 90, Br 10 1.11 0.155 7.2 O.659 O.18 O.O1 0.262 The invention 5 AgI 90, Br 10 1.12 O.O8O 14.O O.532 O.18 O.O1 0.172 Comparative example 6 AgI 90, Br 10 1.15 O.177 6.5 O.705 O.18 O.O1 0.154 Comparative example RX-U - 0.17 O.O1 0.289 Comparative example fluorescent Substance and having a peak emission wave- Example 8 length of 425 nm), and the resultant assembly was arranged in position. The X-ray vessel was DRX-3724HD (trade 0903 1. Formation of PET Support name) manufactured by Toshiba Corporation and using a tungsten target. A focal Spot size was set at 0.6 mmx0.6 mm. 0904 1-1. Film Formation X-rays were generated through 3 mm thick aluminum 0905 PET was made of terephthalic acid and ethylene equivalent material including a diaphragm. A voltage of 80 glycol in an ordinary manner and had an intrinsic Viscosity KV was applied to three phases with a pulse generator to generate X-rays and the X-rays were made to pass through IV of 0.66 (measured in a mixture of phenol and tetrachlo a filter of water having a thickness of 7 cm, which filter roethane at a weight ratio of 6/4 at 25 C.). This was absorbed X-rays in nearly the same amount as that of X-rays pelletized, and the resultant was dried at 130° C. for 4 hours. which the human body absorbs, to form an X-ray source. This pellet was melted at 300° C., extruded out from a T-die, After exposure, the material was thermally developed with and rapidly cooled. Thus, a non-oriented film was prepared. the above-mentioned developing machine for developing 0906. The film was longitudinally oriented by rolls rotat both sides of materials. The exposure amount at the time of ing at different circumferencial speeds at 110° C. So that the X-ray photography was adjusted So that the average of the longitudinal length thereof after the orientation was 3.3 highest and lowest densities of the developed image would times as long as the original longitudinal length thereof. be 1.0. Next, the film was laterally oriented by a tenter at 130 C. 0899 Subsequently, the sample to be measured was pro so that the lateral length thereof after the orientation was 4.5 cessed with a microdensitometer. At this time, density times as long as the original lateral length thereof. Next, the profile was measured at a Sampling interval of 30 um by oriented film was thermally fixed at 240 C. for 20 seconds, using, as an aperture, a slit having a length of 30 um in the and then laterally relaxed by 4% at the same temperature. operating direction and a length of 500 um in a direction Next, the chuck portion of the tenter was slitted, and the both perpendicular to the operating direction. This procedure was edges of the film were knurled, and the film was rolled up repeated twenty times and the obtained values were aver at 4 kg/cm. The rolled film having a thickness of 175 um aged to obtain a density profile on which CTF calculation was obtained. was based. Thereafter, the peak of the rectangular wave for each frequency in the density profile was detected and 0907 1-2. Corona Processing of Surface density contrast for each frequency was calculated. The measured values with respect to a spatial frequency of 2 0908. Both surfaces of this support were processed at a lp/mm are shown in Table 7. rate of 20 m/minute at room temperature by using a Solid State corona processing machine (6 KVA model manufac 0900 3) Evaluation Result tured by Pillar Company). From values of current and Voltage read at this time, it was found that the Support had 0901) The obtained results are shown in Table 7. been processed at 0.375 kV.A.min/m. At this time, the 0902. As can be easily recognized from the data shown in processing frequency was 9.6 kHz, and a gap clearance Table 7, a photographic material that is exposed to light in between an electrode and a dielectric roll was 1.6 mm. US 2005/0069827 A1 Mar. 31, 2005 79

0909 Formation of Undercoated Support added to the system in an amount of 3x10" mol per mol of silver. 0.5 mol/L Sulfuric acid was added to the system so as 0910 1) Preparation of Coating Liquid for Undercoat to adjust pH of the System at 3.8. Then Stirring was stopped, Layer and precipitating/desalting/washing Steps were carried out. One mol/L Sodium hydroxide was added to the System So as to adjust pH of the system at 5.9 and then a silver halide Pesiresin A-520 59 g dispersion having pAg of 9.0 was prepared. (manufactured by Takamatsu Oil and Fats Co., Ltd.; 30 mass % solution) 0.917) Silver halide grains in the obtained silver halide Polyethylene glycol monononyl phenyl ether 5.4 g dispersion were made of pure Silver iodide, and included (average ethylene oxide number = tabular grains having an average projected area diameter of 8.5, 10 mass % solution) MP-1OOO 0.91 g 1.35 um, a coefficient of variation of the average projected (manufactured by Soken chemical & area diameter of 18.5%, an average thickness of 0.110 um, Engineering Co., Ltd.; fine and an average aspect ratio of 12.2. The entire projected area polymer particles having an average of the tabular grains corresponded to 76% or more of the particle size of 0.4 um) entire projected area of all the Silver halide grains. The Distilled water 935 mL. sphere equivalent diameter thereof was 0.69 lum. A result of X-ray powder diffraction analysis showed that 90% or more 0911) 2) Undercoat of the Silver iodide had gamma phase. 0912 Each surface of the biaxially-oriented polyethylene 0918 Preparation of Silver Halide Emulsion B terephthalate Support having a thickness of 175 um which 0.919. One mole of the AgI tabular grain emulsion which had been Subjected to the above-described corona discharge was the Silver halide emulsion A was placed in a reaction treatment was coated with the coating liquid for the under vessel. A 0.5 mol/L KBr solution and 0.5 mol/L AgNO coat with a wire bar Such that a wet coating amount became solution were added to the emulsion by the double jet 6.6 ml/m (per one side). Each of the resultant coatings was method over 20 minutes at 10 mL/minute at 30° C. to allow dried at 180° C. for 5 min. substantially 10 mol % of silver bromide to epitaxially deposit on the AgI host grains. During this operation, Silver 0913 2. Preparation of Coating Materials potential was kept at +100 mV. Further, 0.5 mol/L Sulfuric 0914) 1) Preparation of Silver Halide Emulsion acid was added to the System So as to adjust pH of the System at 3.8. Then Stirring was stopped, and precipitating/deSalt 0915 Preparation of Silver Halide Emulsion A ing/washing Steps were carried out. One mol/L Sodium 0916 2.3 mL of a 10 mass % potassium iodide, 3.5 mL hydroxide was added to the System So as to adjust pH of the of 0.5 mol/L Sulfuric acid, 36.5 g of phthalated gelatin and system at 5.9. The system was divided in two portions to 160 mL of a 5 mass % methanol solution of 2,2'-(ethylene form silver halide dispersions having pag of 6.5 and 9.0, dithio)diethanol were added to 1421 mL of distilled water. respectively. The resulting solution was kept at 78° C. in a stainless steel 0920. The silver halide dispersion was divided into small reaction pot while it was being Stirred. Solution A was portions. After raising the temperature of each portion to 56 prepared by diluting 22.22 g of silver nitrate with distilled C., chemical sensitizers shown in Table 8 were added to the water Such that the total volume of the resultant mixture was portions, and the resultant mixtures were aged for 60 min 218 mL. Solution B was prepared by diluting 36.6 g of utes to obtain emulsions 101 to 114. potassium iodide with distilled water such that the total volume of the resultant mixture was 366 mL. These solu 0921 Preparation of Silver Halide Emulsion for Prepar tions A and B were added to the content in the reaction pot ing Coating Liquid by a controlled double jet method. At this time, the whole of 0922. One of the silver halide emulsions was molten at Solution A was added at a constant flow rate over 38 minutes. 40° C. and 1 mass % aqueous solution of benzothiazolium Moreover, solution B was added while pag of the system iodide was added thereto in an amount of 7x10 mol per was kept at 10.2. Then, 10 mL of a 3.5 mass % aqueous mol of silver. solution of hydrogen peroxide, and 10.8 mL of a 10 mass % 0923. Further, water was added to the emulsion so that aqueous Solution of benzimidazole were added to the SyS the content of silver of silver halide per kg of the resultant tem. Solution C was prepared by diluting 51.86 g of silver mixed emulsion for coating liquid would become 38.2 g. nitrate with distilled water Such that the total volume of the Then, 1-(3-methylureidophenyl)-5-mercaptotetrazole was resultant mixture was 508.2 mL. Moreover, Solution D was prepared by diluting 63.9 g of potassium iodide with dis added to the resultant in an amount of 0.34g per kg of the tilled water Such that the total volume of the resultant mixed emulsion for coating liquid. mixture was 639 mL. These Solutions C and D were added 0924) Further, compound (19) was added to the resultant to the system by the controlled double jet method. At this mixture as a compound having an adsorptive group and a time, the whole of Solution C was added at a constant flow reducing group in an amount of 2x10 molper mol of silver rate over 60 minutes. Moreover, Solution D was added while halide. pAg of the system was kept at 10.2. When ten minutes had 0925, 2) Preparation of Dispersion A of Silver Salt of lapsed Since Staring of addition of Solutions C and D, Fatty Acid potassium hexachloroiridate (III) was added to the System in an amount of 1x10" molper mol of silver. Further, when 40 0926 Preparation of Recrystallized Behenic Acid Seconds had lapsed since completion of addition of Solution 0927 100 kg of behenic acid manufactured by Henkel C, an aqueous Solution of potassium hexacyanoiron (II) was Co. (trade name of product: Edenor C22-85R) was dissolved US 2005/0069827 A1 Mar. 31, 2005 in 1200 kg of isopropyl alcohol at 50° C., and the resultant through electronimicroscopic photography. Average values solution was filtered through a filter having a pore size of 10 of a, b, and c were 0.21 um, 0.4 um and 0.4 um, respectively um and then cooled to 30° C. to recrystallize behenic acid. (a, b and c are defined hereinabove). An average aspect ratio The cooling rate in the recrystallization was controlled to 3 was 2.1. A coefficient of variation of sphere equivalent C./hour. The solution was centrifugally filtered to collect diameters of the particles was 11%. recrystallized crystals, and the crystals were washed with 0932) 19.3 kg of polyvinyl alcohol (trade name, PVA 100 kg of isopropyl alcohol and then dried. The obtained 217) and water were added to the wet cake whose amount crystals were esterified and the resultant was measured by corresponded to 260 kg of the dry weight thereof so that the GC-FID. The resultant had a behenic acid content of 96 mol total amount of the resultant became 1000 kg. The resultant % and, in addition, included 2 mol % of lignoceric acid, 2 was formed into slurry with a dissolver wing, and then mol % of archidic acid and 0.001 mol % of erucic acid. pre-dispersed with a pipe-line mixer (Model PM-10 avail 0928 Preparation of Dispersion of Silver Salt of Fatty able from Mizuho Industry Co.). Acid 0933) Next, the pre-dispersed stock slurry was processed three times in a disperser (MICROFLUIDIZER M-610 0929) 88 kg of recrystallized behenic acid, 422 L of obtained from Microfluidex International Corporation, and distilled water, 49.2 L of a 5 mol/Laqueous NAOH solution equipped with a Z-type interaction chamber) at a controlled and 120 L of t-butyl alcohol were mixed and reacted at 75 pressure of 1150 kg/cm. A silver behenate dispersion was C. for one hour while the resultant System was being stirred. thus prepared. To cool it, corrugated tube type heat eXchang Thus, a sodium behenate Solution B was obtained. Sepa ers were disposed before and behind the interaction cham rately, 206.2 L of an aqueous Solution (pH 4.0) containing ber. The temperature of the coolant in these heat eXchangers 40.4 kg of silver nitrate was prepared and kept at 10° C. A was so controlled that the System could be processed at a reaction vessel containing 635 L of distilled water and 30 L dispersion temperature of 18 C. of t-butyl alcohol was kept at 30° C. The entire amount of the sodium behenate solution and the entire amount of the 0934 3) Preparation of Reducing Agent Dispersion aqueous solution of silver nitrate were added to the content of the vessel at constant flow rates over 93 minutes and 15 0935) Preparation of of Reducing Agent-1 Dispersion seconds and over 90 minutes, respectively, while the content 0936) 10 kg of a reducing agent-1 (2,2'-methylenebis-(4- in the vessel was being Sufficiently stirred. At this time, only ethyl-6-tert-butylphenol)), 16 kg of a 10 mass % aqueous the aqueous solution of silver nitrate was added for 11 solution of modified polyvinyl alcohol (POVAL MP203 minutes after starting the addition of the aqueous Solution of available from Kuraray Co., Ltd.) and 10 kg of water were silver nitrate, addition of Sodium behenate Solution was sufficiently mixed to form slurry. The slurry was fed by a started subsequently, and only the Sodium behenate Solution diaphragm pump into a horizontal sand mill (UVM-2 avail was added for 14 minutes and 15 Seconds after completion able from Imex Corporation) including Zirconia beads which of the addition of the aqueous Solution of Silver nitrate. At had a mean diameter of 0.5 mm, and dispersed therewith for this time, the internal temperature of the reaction vessel was 3 hours. Then, 0.2 g of sodium salt of benzoisothiazolinone kept at 30° C. The external temperature was controlled Such and water were added thereto to adjust the reducing agent that the liquid temperature was constant. The pipe line for concentration of the resultant at 25% by mass. The disper the sodium behenate Solution was a double-walled pipe and Sion was heated at 60° C. for 5 hours. A reducing agent-1 thermally insulated by circulating hot water through the dispersion was thus prepared. The reducing agent particles interspace of the double-walled pipe, and the temperature of in the dispersion had a median diameter of 0.40 um, and a the solution at the outlet of the nozzle tip was adjusted at 75 maximum particles size of at most 1.4 lum. The reducing C. The pipe line for the aqueous silver nitrate Solution was agent dispersion was filtered through a polypropylene filter also a double-walled pipe and thermally insulated by circu having a pore size of 3.0 um to remove foreign objects Such lating cold water through the interspace of the double-walled as dirt from it, and then stored. pipe. The position at which the Sodium behenate Solution was added to the reaction system and that at which the 0937 Preparation of Reducing Agent-2 Dispersion aqueous silver nitrate Solution was added thereto were 0938) 10 kg of a reducing agent-2 (6,6'-di-t-butyl-4,4'- disposed symmetrically relative to the shaft of the stirrer dimethyl-2,2'-butylidenediphenol), 16 kg of a 10 mass % disposed in the reactor, and the nozzle tips of the pipes were aqueous solution of modified polyvinyl alcohol (POVAL spaced apart from the reaction Solution level in the reactor. MP203 available from Kuraray Co., Ltd.) and 10 kg of water 0930. After adding the sodium behenate solution was were sufficiently mixed to form slurry. The slurry was fed by finished, the reaction system was stirred for 20 minutes at a diaphragm pump into a horizontal sand mill (UVM-2 that temperature, and then heated to 35° C. over 30 minutes. available from Imex Corporation) including Zirconia beads Thereafter, the system was aged for 210 minutes. Immedi which had a mean diameter of 0.5 mm, and dispersed ately after completion of the ageing, the System was cen therewith for 3 hours and 30 minutes. Then, 0.2 g of Sodium trifugally filtered to collect a Solid component, which was salt of benzoisothiazolinone and water were added thereto to washed with water until the conductivity of the Washing adjust the reducing agent concentration of the resultant at waste reached 30 uS/cm. The solid thus obtained was a silver 25% by mass. The dispersion was then heated at 40° C. for salt of a fatty acid and was stored as wet cake without drying 1 hour, and then at 80° C. for 1 hour. A reducing agent-2 It. dispersion was thus prepared. The reducing agent particles in the dispersion had a median diameter of 0.50 um, and a 0931) The shapes of the silver behenate particles obtained maximum particle size of at most 1.6 lim. The reducing herein were analyzed on the basis of their images taken agent dispersion was filtered through a polypropylene filter US 2005/0069827 A1 Mar. 31, 2005 having a pore size of 3.0 um to remove foreign objects Such prepare slurry. The Slurry was fed by a diaphragm pump into as dirt from it, and then Stored. a horizontal sand mill (UVM-2 available from Imex Cor 0939 4) Preparation of Hydrogen Bonding Compound poration) including Zirconia beads which had a mean diam Dispersion eter of 0.5 mm, and dispersed therewith for 5 hours. Then, 0.2 g of Sodium Salt of benzoisothiazolinone and water were 0940 Preparation of Hydrogen Bonding Compound-I added thereto to prepare an organic polyhalogen com Dispersion pound-1 dispersion having an organic polyhalogen com 0941 10 kg of a hydrogen bonding compound-1 (tri(4- pound content of 30 mass %. The organic polyhalogen t-butylphenyl)phosphine oxide), 16 kg of a 10 mass % compound particles in the dispersion had a median diameter aqueous solution of modified polyvinyl alcohol (POVAL of 0.41 um, and a maximum particle size of at most 2.0 lim. MP203 available from Kuraray Co., Ltd.) and 10 kg of water The organic polyhalogen compound dispersion was filtered were sufficiently mixed to form slurry. The slurry was fed by through a polypropylene filter having a pore size of 10.0 um a diaphragm pump into a horizontal sand mill (UVM-2 to remove foreign objects Such as dirt from it, and then available from Imex Corporation) containing Zirconia beads Stored. which had a mean diameter of 0.5 mm, and dispersed 0948 Preparation of Organic Polyhalogenated Com therewith for 4 hours. Then, 0.2 g of sodium salt of ben pound-2 Dispersion Zoisothiazolinone and water were added thereto to adjust the 0949) 10 kg of an organic polyhalogen compound-2 hydrogen bonding compound concentration of the resultant (N-butyl-3-tribromomethanesulfonylbenzamide), 20 kg of a at 25% by mass. The dispersion was heated at 40 C. for 1 10 mass % aqueous solution of modified polyvinyl alcohol hour and then at 80° C. for 1 hour. A hydrogen bonding (POVALMP203 available from Kuraray Co., Ltd.), and 0.4 compound-1 dispersion was thus prepared. The hydrogen kg of a 20 mass % aqueous Solution of Sodium triisopro bonding compound particles in the dispersion had a median pylnaphthaleneSulfonate were Sufficiently mixed to prepare diameter of 0.45 um, and a maximum particle size of at most 1.3 lim. The hydrogen bonding compound dispersion was Slurry. The Slurry was fed by a diaphragm pump into a filtered through a polypropylene filter having a pore size of horizontal sand mill (UVM-2 available from Imex Corpo 3.0 um to remove foreign objects Such as dirt from it, and ration) including Zirconia beads which had a mean diameter then Stored. of 0.5 mm, and dispersed therewith for 5 hours. Then, 0.2g of Sodium Salt of benzoisothiazolinone and water were 0942 5) Preparation of Development Accelerator-1 Dis added thereto to adjust the organic polyhalogen compound persion content of the resultant at 30 mass %. The dispersion was 0943) 10 kg of a development accelerator-1,20 kg of a 10 heated at 40 C. for 5 hours. An organic polyhalogen mass % solution of modified polyvinyl alcohol (POVAL compound-2 dispersion was thus obtained. The organic MP203 available from Kuraray Co., Ltd.) and 10 kg of water polyhalogen compound particles in the dispersion had a were sufficiently mixed to form slurry. The slurry was fed by median diameter of 0.40 tim, and a maximum particle size a diaphragm pump into a horizontal sand mill (UVM-2 of at most 1.3 lim. The organic polyhalogen compound available from Imex Corporation) containing Zirconia beads dispersion was filtered through a polypropylene filter having which had a mean diameter of 0.5 mm, and dispersed a pore Size of 3.0 um to remove foreign objects Such as dirt therewith for 3 hours and 30 minutes. Then, 0.2 g of sodium from it, and then Stored. Salt of benzoisothiazolinone and water were added thereto to 0950 7) Preparation of Silver Iodide Complex-Forming prepare a development accelerator-1 dispersion having a Agent (22) development accelerator concentration of 20% by mass. The 0951) 8 kg of modified polyvinyl alcohol MP203 was development accelerator particles in the dispersion had a dissolved in 174.57 kg of water, and 3.15 kg of a 20 mass median diameter of 0.48 um, and a maximum particle size % aqueous Solution of Sodium triisopropylnaphthalene of at most 1.4 lim. The development accelerator dispersion sulfonate and 14.28 kg of a 70 mass % aqueous solution of was filtered through a polypropylene filter having a pore size silver iodide complex-forming agent (NO. 22) were added to of 3.0 um to remove foreign objects Such as dirt from it, and the resultant Solution So as to prepare a 5 mass % Solution then Stored. of the Silver iodide complex-forming compound (No. 22). 0944 Development accelerator-2 and color toning agent-1 Solid dispersions respectively having concentrations 0952) 8) Preparation of SBR Latex Liquid of 20 mass % and 15 mass % were prepared in the same 0953) An SBR latex was prepared as follows. manner as the preparation of the development accelerator-1 dispersion. 0954 287 g of distilled water, 7.73 g of a surfactant (PIONIN A-43-S produced by Takemoto Yushi Corporation 0945 6) Preparation of Polyhalogenated Compound Dis and having a solid content of 48.5 mass %), 14.06 ml of 1 persion mol/liter NaOH, 0.15 g of tetrasodium ethylenediaminetet 0946 Preparation of Organic Polyhalogenated Com raacetate, 255 g of Styrene, 11.25 g of acrylic acid, and 3.0 pound-1 Dispersion g of tert-dodecylmercaptain were put into the polymerization reactor of a gas monomer reaction apparatus (TAS-2J Model 0947 10 kg of an organic polyhalogen compound-1 available from Taiatsu Techno Corporation). The reactor was (tribromomethanesulfonylbenzene), 10 kg of a 20 mass % sealed off, and the content therein was stirred at 200 rpm. aqueous solution of modified polyvinyl alcohol (POVAL The internal air was exhausted via a vacuum pump, and MP203 available from Kuraray Co., Ltd.), 0.4 kg of a 20 replaced a few times repeatedly with nitrogen. Then, 108.75 mass % aqueous Solution of Sodium triisopropylnaphthale g of 1,3-butadiene was introduced into the reactor under neSulfonate, and 14 kg of water were Sufficiently mixed to preSSure, and the internal temperature of the reactor was US 2005/0069827 A1 Mar. 31, 2005 82 raised to 60° C. A solution in which 1.875 g of ammonium dispersion, 75 g of the reducing agent-2 dispersion, 106 g of persulfate was dissolved in 50 ml of water was added to the the hydrogen bonding compound-1 dispersion, 4.8g of the system, and the system was stirred for 5 hour. It was further development accelerator-1 dispersion, 3.0 g of the develop heated to 90° C. and stirred for 3 hours. After the reaction ment accelerator-2 dispersion, 2.0 g of the color toning was completed, the internal temperature was lowered to agent-1 dispersion, 9 ml of the aqueous Solution of mercapto room temperature. Then, NaOH and NHOH (both 1 mol/ liter) were added to the system at a molar ratio of Na" and compound-1, and 27 ml of the aqueous Solution of mercapto NH, of 1/5.3 so as to adjust the pH of the system at 8.4. compound-2 were successively added to 1,000 g of the Next, the System was filtered through a polypropylene filter dispersion A of the silver salt of the fatty acid obtained above having a pore size of 1.0 lim to remove foreign objects Such and 104 ml of water. Then, the silver iodide complex as dirt from it, and then stored. 774.7 g of SBR latex was forming agent was added to the resultant in an amount of 8 thus obtained. Its halide ion content was measured through mol % per mol of silver. Just before coating, each of the ion chromatography, and the chloride ion concentration of silver halide emulsion for coating liquid (Table 8) was added the lateX was 3 ppm. The chelating agent concentration to and Sufficiently mixed with the above mixture so that the thereof was measured through high-performance liquid amount of silver of the emulsion became 0.25 mol per mol chromatography, and was 145 ppm. of silver salt of fatty acid. The resultant Coating liquid for 0955 The mean particle size of the latex was 90 nm, Tg the image-forming layer was fed as it is to a coating die, and thereof was 17 C., the Solid content thereof was 44% by applied to the Support. mass, the equilibrium moisture content thereof at 25 C. and 0966 Preparation of Coating Liquid for Intermediate 60% RH was 0.6 mass %, and the ion conductivity thereof Layer was 4.80 mS/cm. To measure the ion conductivity, a con ductivity meter CM-30S manufactured by To a Denpa 0967 27 ml of a 5 mass % aqueous solution of AERO Kogyo K. K. was used. In the device, the 44 mass % latex SOL OT (available from American Cyanamid Company), was measured at 25 C. Its pH was 8.4. 10.5 ml of a 20 mass % aqueous solution of diammonium phthalate and water were added to 772 g of a 10 mass % 0956 9) Preparation of Mercato Compound aqueous solution of polyvinyl alcohol (PVA-205 available 0957 Preparation of Aqueous Solution of Mercapto from Kuraray Co., Ltd.), 5.3 g of the pigment-1 dispersion Compound-1 and 226 g of a 27.5 mass % latex of a methyl methacrylate/ Styrene/butyl acrylate/hydroxyethyl methacrylate/acrylic 0958 7 g of a mercapto compound-1 (1-(3-sulfophenyl)- acid copolymer (copolymerization weight ratio. 64/9/20/5/ 5-mercaptotetrazole sodium salt) was dissolved in 993 g of 2) So that the total amount of the resultant mixture became water to form a 0.7 mass % aqueous Solution. 880 g. The pH of the mixture was adjusted at 7.5 by adding 0959 Preparation of Aqueous Solution of Mercapto NaOH to the mixture. A coating liquid for intermediate layer Compound-2 was thus obtained. This was fed into a coating die So that the amount of the coating liquid was 10 ml/m. 0960 20 g of a mercato compound-2 (1-(3-methylure idophenyl)-5-mercaptotetrazole) was dissolved in 980 g of 0968. The viscosity of the coating liquid was 65 mPa-S when measured with a B-type viscometer (rotor No. 1, 60 water to form a 2.0 mass % aqueous Solution. rpm) at 40 0961) 2) Preparation of Pigment-1 Dispersion 0969 Preparation of Coating Liquid for First Surface 0962 250 g of water was added to and sufficiently mixed Protective Layer with 64 g of C.I. Pigment Blue 60 and 6.4 g of Demol N 0970) 64 g of inert gelatin was dissolved in water, and 80 (manufactured by Kao Corporation) to form slurry. 800g of g of a 27.5 mass % latex of a methyl methacrylate/styrene/ Zirconia beads having an average diameter of 0.5 mm were butyl acrylate/hydroxyethyl methacrylate/acrylic acid prepared and the Slurry and the Zirconia beads were put in a copolymer (copolymerization weight ratio. 64/9/20/5/2), 23 vessel. The resulting mixture was Stirred by a dispersion ml of a 10 mass % methanol solution of phthalic acid, 23 ml machine (/4G Sand grinder mill manufactured by Imex Co.) of a 10 mass % aqueous Solution of 4-methylphthalic acid, for 25 hours. The resultant dispersion was taken out of the 28 ml of 0.5 mol/L Sulfuric acid, 5 ml of a 5 mass % aqueous vessel and diluted with water to obtain a 5 mass % pig solution of AEROSOLOT (available from American Cyana ment-1 dispersion. The pigment particles contained in the mid Company), 0.5 g of phenoxyethanol, 0.1 g of ben pigment dispersion thus obtained had an average particle Zoisothiazolinone, and water were added to the resultant size of 0.21 um. Solution So that the total amount of the resultant mixture 0963. 3. Preparation of Coating Liquid became 750 g. Just before application thereof, 26 ml of 4 mass % chromium alum was mixed with the mixture by 0964 Preparation of Coating Liquid for Image-Forming using a Static mixer. The resultant coating liquid was fed into Layer a coating die So that the amount of the resultant coating was 0965 35 g of the pigment-1 dispersion, 6.3 g of the 18.6 ml/mi. organic polyhalogen compound-I dispersion, 20.7 g of the 0971) The viscosity of the coating liquid was 20 mPa-S organic polyhalogen compound-2 dispersion, 1060 g of the when measured with a B-type viscometer (rotor No. 1, 60 SBR latex (Tg: 17 C.) liquid, 75 g of the reducing agent-1 rpm) at 40 US 2005/0069827 A1 Mar. 31, 2005

0972 Preparation of Coating Liquid for Second Surface Protective Layer -continued Sensitizing dye-3 0973 80 g of inert gelatin was dissolved in water, and 102 g of a 27.5 mass % latex of a methyl methacrylate/ O C2H5 O styrene/butyl acrylate/hydroxyethyl methacrylate/acrylic acid copolymer (copolymerization weight ratio. 64/9/20/5/ 2), 3.2 ml of a 5 mass % solution of a fluorine-containing C O)-in-a- Cl Surfactant (F-1), 32 ml of a 2 mass % aqueous solution of a fluorine-containing surfactant (F-2), 23 ml of a 5 mass % ( Solution of AEROSOLOT (available from American Cyana mid Company), 4 g of fine polymethyl methacrylate par ticles (mean particle size: 0.7 um), 21 g of fine polymethyl 0978) 2) Evaluation of Performance methacrylate particles (mean particle size: 4.5 um), 1.6 g of 0979 The double-side-coated photosensitive material 4-methylphthalic acid, 4.8 g of phthalic acid, 44 ml of 0.5 prepared in this manner was evaluated as follows. mol/L Sulfuric acid, 10 mg of benzoisothiazolinone, and 0980 The sample was sandwiched between two X-ray water were added to the resultant solution so that the total ortho screens (HG-M manufactured by Fuji Photo Film Co., amount of the resultant mixture became 650 g. Just before Ltd., containing as a fluorescent Substance terbium-activated application thereof, 445 ml of an aqueous solution contain gadolinium oxysulfide and having a peak emission wave ing 4 mass % of chromium alum and 0.67 mass % of length of 545 nm) to form an assembly for image formation. phthalic acid was mixed with the mixture by using a static The assembly was exposed to X-rays for 0.05 seconds and mixer. A coating liquid for the Surface protective layer was Subjected to X-ray Sensitometry. The X-ray apparatus used thus obtained. The coating liquid was fed into a coating die, was DRX-3724HD (trade name) manufactured by Toshiba With its flow rate So controlled that its coating amount was Corporation and having a tungsten target. A voltage of 80 8.3 ml/m. KVp was applied to three phases with a pulse generator to 0974. The viscosity of the coating liquid was 19 mPa-S generate X-rays and the X-rays were made to pass through when measured with a B-type viscometer (rotor No. 1, 60 a filter of water having a thickness of 7 cm, which filter rpm) at 40° C. absorbed X-rays in nearly the same amount as that of X-rays which the human body absorbs, to form an X-ray source. 0975 Preparation of Photothermographic Material While an X-ray exposure amount was varied by varying the 0976) 1) Preparation of Coated Sample distance between the assembly and the X-ray source, the 0977) Each side of the support was simultaneously coated material was exposed stepwise at an interval of logE=0.15. With the coating liquid for image-forming layer which After exposure, the material was thermally developed under contained one of the silver halide emulsions 101 to 113 and the following thermal development conditions. The density to which sensitizing dyes 1, 2 and 3 were added just before of the resultant image was measured with a densitometer. coating, the coating liquid for intermediate layer, the coating 0981) The thermal development unit of FUJIMEDICAL liquid for first Surface protective layer and the coating liquid DRYLASER IMAGER FM-DPL was remodeled to produce for Second Surface protective layer, and the resultant coat a thermal development apparatus that could heat the material ings were dried. Photothermographic materials which had an from both sides thereof. Further, the apparatus was also image-forming layer containing a silver coating amount of remodeled to enable conveying a film sheet by replacing the 1.65 g/mon each side of the support and in which the total conveying roller in the thermal development unit with a heat Silver coating amount that was the Sum of the silver amount drum. Temperatures of four panel heaters were set to 112 of the silver salt of fatty acid and that of the silver halide was C., 118°C., 120° C., and 120° C., respectively and that of 3.3 g/m were thus prepared. the heat drum was set to 120° C. In addition, the conveying Speed was increased So that the total period of thermal development became 14 seconds. Sensitizing dye-1 0982) The chemical structures of compounds used in this O O Example are shown below.

O-alk OCH Cyanine dye compound-1 st st SOs SO3H N(C2H5)3 Sensitizing dye-2 C2Hs C2H5 Cl X-CH=CH-CH={ OC Cl Cl Cl Cs11 CH2-(CH2)3-SOs US 2005/0069827 A1 Mar. 31, 2005 84

-continued -continued Blue dye compound-1 Polyhalogenated compound-2

CONHC Ho

(SO3Na)n SOCBr Mercapto compound-1 N-N (SONH2)m N (n N ) SH

n = 0.5-2.0 SONa m = 0.5-2.5 Mercapto compound-2 Ultraviolet absorbent-1 N-N CN N ( n N x SH C S 21 2 SO2C12H2s(n)

C3H6SOK Reducing agent-1 NHCONHCH OH OH Development accelerator-1

NHNHCONH O Reducing agent-1 als, Development accelerator-2 C OH OH OH CONH

OC6H13 Color toning agent-1 Hydrogen bonding compound-1

HO CH2 HO

Compound F-1 --O- CF (CF)nCHCH-SCHCH -COOLi Polyhalogenated compound-1 Mixture of compounds having in or 5-11 Compound F-2 CF (CF)nCH2CH2O(CH2CH2O)mH Ol SOCBr3 Mixture of compounds having in or 5-11 and m or 5-15 US 2005/0069827 A1 Mar. 31, 2005 85

increased Sensitivity. On the other hand, a Sample containing -continued an emulsion which had been Subjected to chemical Sensiti Compound F-3 Zation at pAg of 9.0 showed Somewhat increased Sensitivity, "cooctrict, which was relatively unsatisfactory. As is clear from Table -CHCOOCH-CH.C.F. 8, tellurium Sensitization is the most preferable of calcogen NaOSCH Sensitizations, and gold-calcogen Sensitization results in Compound F-4 considerable Sensitization but in a relatively high fogging level. A more preferable result was obtained by combining "Coocals trooctrict, reduction sensitization and calcogen Sensitization (tellurium -CHCOOCHCH.C. Fo -CHCOOC12H9s NaOS NaOS Sensitization). Further, the grains having a high Silver iodide Mixture of the following content of the invention showed excellent image Storability two compounds after development. It was difficult to predict from conven tional photoSensitive materials which are processed by a wet method that a photothermographic material containing Silver

TABLE 8

Chemical Sensitizer Sample Addition. Amount Relative Image No pAg Compound (mol/mol AgX) Fogging Sensitivity Storability Remarks O1 6.5 - O.26 1OO O Comparative example O2 6.5 Sodium thiosulfate 6.4 x 10 O.28 224 O The invention O3 6.5 Triethylthiourea 6.4 x 10 O.28 239 O The invention O4 6.5 Triphenylphosphine selenide 3.2 x 10 O.34 251 O The invention 05 6.5 Pentafluorophenyl- 2.4 x 10 O.32 273 O The invention Diphenylphpsphine selenide O6 6.5 Bis(N-methyl-N- 2.8 x 10 O.28 339 O The invention Phenylcarbamoyl) telluride O7 6.5 n-butyl-di-i-propylphosphine 6.4 x 10 O.30 288 O The invention telluride O8 Sodium thiosulfate 2.4 x 10 O.42 4O7 O The invention Chloroauric acid 1.0 x 10 Potassium thiocyanate 2.0 x 10 O9 6.5 Dimethylamine borane 2.0 x 10 O.31 257 O The invention 1O 6.5 Dimethylamine borane 2.0 x 10 O.34 368 O The invention Bis(N-methyl-N- 2.8 x 10 phenylcarbamoyl) telluride 11 9.0 - 0.25 62 O Comparative example 12 9.0 Bis(N-methyl-N- 6.4 x 10 O.26 2O1 O The invention phenylcarbamoyl) telluride 13 6.5 Dimethylamine borane 1.0 x 10 O.30 360 O The invention Bis(N-methyl-N- 2.8 x 10 phenylcarbamoyl) telluride

0983. The obtained results are shown in Table 8. halide which has a high Silver iodide content and having 0984. The relative sensitivity is the ratio of inverse num very high Sensitivity and excellent image Storability can be ber of an exposure amount at which an optical density that obtained. Further, samples 101 and 111 had somewhat was the Sum of fogging level and 0.2 was obtained to that of yellowish color tone after thermal development. However, Sample 101. The larger the ratio, the higher the sensitivity. Samples which had been Subjected to chemical Sensitization Unlike Samples 101 to 112, Sample 113 included an emul recited in the invention showed an unexpected preferable Sion which had been Subjected to reduction Sensitization effect in that yellowish tone decreases and darkness with dimethylamine boran and then tellurium Sensitization at increases, as the degree of Sensitization is increased. the time of preparation of epitaxial portions of Silver bro Example 9 mide. 0987. One mol of an emulsion containing silver iodide 0985. In evaluation of image storability, the fogging tabular grains was prepared in the Same manner as the density of the Dmin area of a thermally developed Sample preparation of the Silver halide emulsion Ain Example 8 and was measured immediately after development. After the pH of the emulsion was adjusted at 5.9. Then, the emulsion Sample was exposed to light from a fluorescent lamp having was divided in two portions to prepare Silver halide disper illumination of 850 Lux for three days under environment of Sions having pag of 5.6 and pAg 9.0, respectively. After 40° C. and relative humidity of 50%, the fogging density of each of these silver halide emulsions was divided into Small the Dmin area was measured, and increase in fogging portions, the temperature of these portions was raised to 56 density was obtained. C. Then, chemical sensitizers shown in Table 9 were added 0986 AS is clear from Table 8, it was found that a sample to the portions and the resultant mixtures were aged for 95 containing an emulsion which had been Subjected to chemi minutes to obtain emulsions 120 to 126. Thereafter, coated cal Sensitization at a low pag of 6.5 showed significantly Samples were formed and Subjected to Sensitometry in the US 2005/0069827 A1 Mar. 31, 2005 86

Same manner as in Example 8, except that the emulsions 120 What is claimed is: to 126 were used. Results shown in Table 9 were obtained. 1. A photothermographic material comprising: a Support; Relative sensitivity is the ratio of inverse number of an and an image-forming layer containing a photoSensitive exposure amount at which an optical density that was the Silver halide, a non-photoSensitive organic Silver Salt, a Sum of fogging level and 0.2 was obtained to that of Sample reducing agent for Silver ions and a binder on at least one 120. Side of the Support, wherein the photosensitive Silver halide

TABLE 9

Chemical Sensitizer

Sample Addition. Amount Relative Image No PAg Compound (mol/mol AgX) Fogging Sensitivity Storability Remarks 12O 5.6 - O.24 1OO O Comparative example 121 5.6 Sodium thiosulfate 8.2 x 10 O.24 132 O The invention 122 5.6 Pentafluorophenyl- 8.2 x 10 O.30 162 O The invention Diphenylphpsphine selenide 123 5.6 Bis(N-methyl-N- 4.1 x 10 0.25 209- O The invention Phenylcarbamoyl)telluride 124 5.6 Dimethylamine borane 4.0 x 10 O.28 161 O The invention 125 9.0 - O.24 81 O Comparative example 126 9.0 Bis(N-methyl-N- 6.4 x 10 O.24 122 O The invention Phenylcarbamoyl)telluride

0988 AS is clear from Table 8, thermographic materials includes tabular grains with an average Silver iodide content of the invention containing Silver iodide tabular grains of 40 mol % or more, an average thickness within a range which had been Subjected to chemical Sensitization at pAg of 0.001 to 0.5 um and an average aspect ratio of 2 or more. of 5.6 showed significantly increased sensitivity. On the 2. A photothermographic material according to claim 1, other hand, a Sample containing an emulsion which had been wherein the average thickness of the tabular grains is 0.001 Subjected to chemical Sensitization at pAg of 9.0 showed to 0.2 lum. Somewhat increased Sensitivity, which was slightly inferior 3. A photothermographic material according to claim 1 or to that of the materials containing the Silver iodide tabular 2, wherein the average thickness of the tabular grains is grains which had been Subjected to chemical Sensitization at 0.001 to 0.1 um. pAg of 5.6. Further, from comparison of results shown in 4. A photothermographic material according to claim 1, Table 8 and those in table 9, the degree of sensitization in wherein the average thickness of the tabular grains is 0.001 emulsion A was slightly Smaller than that in emulsion B. to 0.05um. However, it is an original knowledge of the invention that 5. A photothermographic material according to claim 1, Sufficient Sensitization can be achieved in photothermo wherein the tabular grains are formed by a nucleus forming graphic materials by chemically Sensitizing Silver iodide process and a grain growing process, and the grain growing tabular grains. process has adding Silver halide fine grains having a size Smaller than the average thickness. Example 10 6. A photothermographic material according to claim 5, wherein adding the Silver halide fine grains having the size 0989. A coated sample was prepared, exposed to X-rays Smaller than the average thickneSS in the grain growing and thermally developed in the Same manner as in Examples process is conducted Such that the amount of the Silver 8 and 9 except that no Sensitizing dye was added to an halide fine particles added are 10 mol% or more of the entire emulsion, and that a X-ray regular screens (HI-SCREEN B3 Silver amount of the tabular grains. manufactured by Fuji Photo Film Co., Ltd., containing a 7. A photothermographic material according to claim 5, fluorescent Substance CaWO and having a peak emission wherein the average grain size of the Silver halide fine grains wavelength of 425 nm) were used as the fluorescent Screen. added in the grain growing process is 0.0005 to 0.04 um. 8. A photothermographic material according to claim 7, 0990 The result showed that good sensitization could be wherein the average grain size of the Silver halide fine grains obtained as in Examples 8 and 9. added in the grain growing process is 0.0005 to 0.025 um. 9. A photothermographic material according to claim 1, Example 11 wherein the average aspect ratio of the tabular grains is 5 to 0991. A coated sample was prepared, exposed to X-rays 70. and thermally developed in the Same manner as in Examples 10. A photothermographic material according to claim 1, 8 and 9 except that the layer containing the photoSensitive wherein the average projected area equivalent diameter of silver halide emulsion was formed on only one side of the the tabular grains is 0.1 to 5.0 um, and the variation film Support, and that a fluorescent Screen for mammogra coefficient of projected area equivalent diameters is 25% or phy (UM MANMO FINE manufactured by Fuji Photo Film leSS. Co., Ltd.) was used as the fluorescent Screen. The result 11. A photothermographic material according to claim 1, showed that good Sensitization could be obtained as in wherein the average Silver iodide content of the photosen Examples 8 and 9. sitive silver halide is 80 mol % or more. US 2005/0069827 A1 Mar. 31, 2005 87

12. A photothermographic material according to claim 11, irradiating the Subject with X-rays having an energy level wherein the average Silver iodide content of the photosen in a range of 25 kVp to 125 kVp; sitive silver halide is 90 mol % or more. 13. A photothermographic material according to claim 1, removing the photothermographic material from the wherein the photoSensitive Silver halide has an epitaxial assembly, and junction. 14. A photothermographic material according to claim 1, heating the removed photothermographic material at a further comprising a compound capable of Substantially temperature in a range of 90° C. to 180 C. reducing visible light absorption derived from the photo 19. A photosensitive silver halide emulsion according to sensitive silver halide after thermal development. claim 1, comprising: tabular grains having an average Silver 15. A photothermographic material according to claim 14, iodide content of 40 mol % or more, wherein at least a part wherein the compound capable of Substantially reducing of the tabular grains, the entire projected area of which part Visible light absorption is a Silver iodide complex-forming corresponds to 50% or more of the entire projected area of agent. all the tabular grains, has an aspect ratio of 2 or more, and 16. A photothermographic material according to claim 1, the average thickness of the tabular grains is within a range wherein the image-forming layer is disposed on one side of from 20 nm less than to 20 nm more than a thickness at the Support. which reflectance becomes maximum in a wavelength range 17. A photothermographic material according to claim 1, in which the silver halide emulsion has sensitivity. wherein the image-forming layer is disposed on both sides 20. A photothermographic material according to claim 1, of the Support. comprising: a Support, and an image-forming layer contain 18. A method for forming an image on the photothermo ing a photoSensitive Silver halide, a non-photosensitive graphic material according to claim 1, the method compris organic Silver Salt, a reducing agent for Silver ions and a Ing: binder on at least one side of the Support, wherein the photosensitive Silver halide includes tabular grains, has a disposing the photothermographic material between a pair silver iodide content of 40 mol % or more, and has been of X-ray intensifying Screens to obtain an assembly for chemically Sensitized by at least one of calcogen Sensitiza image formation; tion, gold-calcogen Sensitization and reduction Sensitization. arranging a Subject between the assembly and an X-ray SOurce,