United States Patent (19) 11 3,854,947 Ritchey (45) Dec. 17, 1974 (54) PROCESS AND SOLUTION FOR FIXING AN 57 ABSTRACT IMAGE ON SLVER HALDE PRINTS A rapid process for producing a stable visible image in 76 Inventor: Edward R. Ritchey, 303 S. 5th St., a photographic silver halide emulsion layer containing St. Joseph, Mo. 64501 a latent image which comprises developing the layer in a photographic silver halide developing solution and 22 Filed: May 16, 1973 fixing the silver halide forming the resultant image by (21) Appl. No.: 360,652 immersing the layer in a novel fixing solution. The novel fixing solution has a major proportion of a solu tion including a first compound selected from the 52) U.S. Cl. ................................. 96/61 R, 96/50 R group consisting of alkali metal thiocyanate, ammo (51 Int. Cl............................ G03c 5/38, GO3c 5/26 nium thiocyanate, alkali metal thiosulfate, and ammo 58 Field of Search........................... 96/50 R, 61 R nium thiosulfate, and a minor proportion of a second (56) References Cited solution including an anionic synthetic detergent hav ing a carbon chain length in the range of between UNITED STATES PATENTS about 7 to about 18 carbon atoms per molecule and 2,343,696 31 1944. Muehler et al...................... 96/61 R selected from the group consisting of ammonium lau 2,578,075 21 1951 Kienast ............................... 96/61 R ryl sulfate sodium lauryl sulfate, potassium lauryl sul 2,860,978 l l l 1958 Henn et al.......................... 96/6 R 3, 132,943 5/1964 Smith et al.......................... 96/61 R fate, aklylated aromatic sulfonic acids, and mixtures thereof, and a water softening agent selected from the 3,404,004 loll 968 Ake ........................................ 96/50 group consisting of sodium hexametaphosphate so 3,573,912 4ll 971 Brown................................. 96/61 R dium pyrophosphate, sodium tetraphosphate, and mix Primary Examiner-Mary F. Kelley tures thereof. The resultant image layer is subse Attorney, Agent, or Firm-John H. Widdowson quently rinsed in a moving water bath. 30 Claims, No Drawings 3,854,947 2 PROCESS AND SOLUTION FOR FIXNG AN process completely cleared the photographic layer of MAGE ON SILVER HALDE PRINTS all chemical residue in minimultime with a single soak, BACKGROUND OF THE INVENTION and simultaneously to soaking the process provided a flattening treatment. However, this patented process 1. Field of the Invention did not curtail the time for fixing the silver halide form This invention relates to photography. Most specifi ing the resultant latent image by immersing the layer in cally, this invention provides a rapid process for pro a thiosulfate or thiocyanate solution; nor could this ducing a stable visible image in a photographic silver process eliminate the step of stopping the action of the halide emulsion layer containing a latent image, and a developing solution by immersing the layer in an acetic novel fixing solution for use therein. O 2. Description of the Prior Art acid solution. It is generally old in the art of producing a stable visi Therefore, what is needed and what has been in ble image and photographic silver halide emulsion vented by me since Oct. 1, 1968, the date which Ake layer containing a latent image formed therein by expo U.S. Pat. No. 3,404,004 issued, is a novel process and sure to light in a camera, enlarger, X-ray machine, or 15 a new fixing solution which is to be used therein, which similar apparatuses, to develop the silver halide layer in produces a stable visible image in a photographic silver a developing solution, to stop the developing action of halide emulsion layer containing a latent image without the developer solution, to fix the silver halide forming the foregoing deficienciess associated with the prior the resultant image by immersing the layer in a stabiliz art. ing solution, and to subsequently rinse the resultant 20 SUMMARY OF THE INVENTION photographic image layer in a moving water bath. This process has been disclosed by Richard W. Henn et al It is therefore an object of this invention to provide in U.S. Pat. No. 2,860,978, patented Nov. 18, 1958, a novel process and fixing solution for producing a sta Eric T. Smith et al in U.S. Pat. No. 3,132,943, patented ble visible image in a photographic silver halide emul May 12, 1964, and in Ake U.S. Pat. No. 3,404,004, pa 25 sion layer containing a latent image which includes a tented Oct. 1, 1968. Prior to Ake patent, it was com shorter fixing time with archival permanence. mon subsequent to fixing to go through an extensive It is another object of this invention to provide a and time consuming washing operation taking approxi novel process and fixing solution for producing a stable mately from 30 minutes to 60 minutes in order to re visible image in a photographic silver halide emulsion move all fixing chemicals from the plate or print. The 30 layer containing a latent image which requires no stop removal of these fixing chemicals and soluble by bath and gives no darkroom odors. products of the fixing operation is necessary in order to It is yet another object of this invention to provide a prevent deterioration of the print, film, or plate caused new photographic processing method and a non-toxic, from residual thiosulfate or thiocyanate solutions con biodegradable fixing solution wherein there is less wash verting part of the silver image into a yellowish or 35 time and is relatively economical to manufacture and brownish silver sulfide. This extensive washing could be install in known apparatuses and processes, shortened to approximately 3 minutes, followed by im Still, other objects will be apparent to those skilled in mersion into a running water bath for 20 minutes. Even the art from the following description of this invention. the inclusion of the "hypo' eliminator step and subse The foregoing objects were achieved according to quent washing should be followed by another bath op 40 the practice of this invention. Broadly, this invention eration for flattening the print or plate; which should comprises an improved rapid process for producing a still yet be followed by still another bath to provide for stable visible image in a photographic silver halide treatment prior to handling the plate or print on an en emulsion layer containing a latent image which in larging machine, orsimilar apparatus, and in toning op cludes developing the layer in a photographic silver erations. The time consuming washing operation foll 45 halide developing solution. Subsequent to developing, lowing the hypo eliminator step normally takes from the silver halide forming the resultant latent image is between 25 to 35 minutes. Conventional processes fixed by immersing the layer in a novel fixing solution after the hypo treatment require a minimum of four having a major proportion of a solution including a first washing operations, baths, or solutions, and the equip compound selected from the group consisting of alkali ment form handling the same. Notwithstanding this rig 50 metal thiocyanate, ammonium thiocyanate, alkali orous extensive and time consuming washing, fre metal thiosulfate and ammonium thiosulfate. The novel quently a portion of the chemicals used to process the fixing solution additionally includes a minor proportion print or plate still remain and decompose to cause of a second solution including an anionic synthetic de staining. tergent having a carbon chain length in the range of be Ake U.S. Pat. No. 3,404,004, discloses a new rapid 55 tween about 7 to about 18 carbon atoms per molecule process and a final soak bath used therein for produc and selected from the group consisting of ammonium ing a stable image in a photographic layer containing a lauryl sulfate, sodium lauryl sulfate, potassium lauryl latent image which solved many of the foregoing prob sulfate, alkylated aromatic sulphonic acids, and mix lems associated with developing processes known to tures thereof, and a water softening agent selected from the prior art. This patented rapid process includes the 60 the group consisting of sodium hexametaphosphate, so steps of (1) developing the layer in a developing solu dium pyrophosphate, sodium tetraphosphate, and mix tion; (2) stopping the action of the developing solution; tures thereof. The second solution preferably addition (3) fixing the resultant image in a stabilizing solution; ally includes a print flattening agent selected from the and (4) treating the layer in the final soak bath for re 65 group consisting of propylene glycol, hexylene glycol, moving chemical residue. Following the last step, the ethylene glycol, glycerol, and mixtures thereof; and a resultant image is rinsed in a moving water bath for a defoaming agent selected from the group consisting of time interval in a range of about 4 to 7 minutes. The methylhexacarbonyl sulfonated ores, sulfonated sili 3,854,947 3 4 cones, and mixtures thereof. Following fixing, the re made from glacial acetic acid which has been diluted sultant image layer is rinsed in a moving water bath. with water in a ratio of about three parts of glacial Thus, by the practice of this invention, there is pro acetic acid with eight parts of water. Crystalline boric vided a rapid and economical process for producing a acid should be used instead of powdered boric acid be stable visible image in a photographic silver halide cause the powdered acid dissolves only with great diffi emulsion layer containing a latent image, and a novel culty. fixing solution which is used within the process. If an alkaline non-hardening bath is desired, the first Detailed Description of the Invention fixing agent compound should have a concentration in the range of between about 145 to about 175 grams per In the new rapid process of my invention, the photo O liter of water; the desiccated alkali metal sulfite or am graphic print, X-ray, plates, negatives, or other photo monium sulfite should include a concentration in the graphic elements are initially placed in a silver halide range of between about 4 to about 9 grams per liter of developing solution.