USOO683O874B2 (12) United States Patent (10) Patent No.: US 6,830,874 B2 Kondo et al. (45) Date of Patent: Dec. 14, 2004

(54) METHOD FOR MAKING LITHOGRAPHIC 6,440,633 B1 8/2002 Kawauchi ...... 430/270.1 PRINTING PLATE 6,716,569 B2 4/2004 Hotta et al...... 430/302 2002/0O397O3 A1 4/2002 Hotta et al...... 430/302 (75) Inventors: Shun-ichi Kondo, Shizuoka-Ken (JP); 2002/0177071 A1 11/2002 Okamoto ...... 430/270.1 Yuichi Shiraishi, Shizuoka-Ken (JP) 2003/O165768 A1 9/2003 Hotta et al...... 430/146 FOREIGN PATENT DOCUMENTS (73) Assignee: Fuji Photo Film Co., Ltd., EP 1 O13 469 A1 6/2000 ...... B41N/3/03 Minami-Ashigara (JP) JP 10-28.2645 10/1998 ...... GO3F/7/OO (*) Notice: Subject to any disclaimer, the term of this JP 2000-105462 A 4/2000 ...... GO3F/7/11 patent is extended or adjusted under 35 * cited by examiner U.S.C. 154(b) by 33 days. Primary Examiner Barbara L. Gilliam (74) Attorney, Agent, or Firm-Burns, Doane, Swecker & (21) Appl. No.: 10/188,079 Mathis, L.L.P. (22) Filed: Jul. 3, 2002 (57) ABSTRACT (65) Prior Publication Data A method for preparing a lithographic printing plate which US 2003/0143487 A1 Jul. 31, 2003 comprises imagewise exposing to light a presensitized plate useful for making a lithographic printing plate having an (30) Foreign Application Priority Data intermediate layer and a photosensitive layer on an alumi Jul. 9, 2001 (JP) ...... 2001-208108 num Substrate in this order and developing the imagewise exposed plate with a developer, wherein Said intermediate (51) Int. Cl...... G03F 7/11; G03F 7/32 layer comprises a polymer compound comprising at least a (52) U.S. Cl...... 430/302; 430/271.1; 430/278.1; Structure unit having an acid group and a structure unit 430/281.1; 430/286.1; 430/309; 430/.435; having an onium group and Said developer comprises an 430/494 inorganic alkali Salt and a nonionic Surfactant having poly (58) Field of Search ...... 430/281. 1, 286.1, oxyalkylene ether group and pH of the developer ranges 430/287.1, 288.1, 309, 270.1, 271.1, 278.1, from 11.0 to 12.7. The method provides a lithographic 302, 401, 434, 435, 494 printing plate, which shows good contrast between an image area and non-image area, no background contamination (56) References Cited during printing, good Stability with time and good printing U.S. PATENT DOCUMENTS durability. 6,114,089 A 9/2000 Takita et al...... 430/278.1 12 Claims, No Drawings US 6,830,874 B2 1 2 METHOD FOR MAKING LITHOGRAPHIC J.P. KOKAI No. 59-101651 discloses a method to PRINTING PLATE improve the background contamination of a PS plate having a photoSensitive layer comprising a diazo compound and a BACKGROUND OF THE INVENTION photopolymerizable compound when the plate is kept for a The present invention relates to a method for making a long time, which the method comprises coating a polymer lithographic printing plate from a presensitized plate having comprising a repeating unit having a Sulfonic acid as an a photopolymerizable photoSensitive layer on an aluminum intermediate layer. The storage stability of the PS plate Substrate. More specifically, the present invention relates to prepared by the method is enough when the PS plate has a a method for making a lithographic printing plate which relatively low Sensitive photopolymerizable photoSensitive shows an improved development performance thus show a layer of which sensitivity which can be treated with the resistivity to printing contamination and has an increased conventional PS plate-exposing device. However, the effect Strength of image with decreased development damage. is not sufficient when the PS plate has a highly sensitive When printings are prepared from a lithographic printing photopolymerizable photoSensitive layer that is exposed to plate, it is important to obtain printings with no background 15 laser light as used for CTP technique. contamination. Generally, the occurrence of background The method to deposit a basecoat layer comprising a contamination in printings increases with the Storage time of a presensitized plate used for making a lithographic printing compound highly Soluble in a developer or the method to plate (hereinafter, referred to as PS plate) after production. add Such a compound to the photopolymerizable photosen In particular, this phenomenon becomes more intense when Sitive layer is effective for improving the background con the PS plate has been Stored under a high temperature and tamination property of a PS plate. But an irradiated portion high humidity. It is particularly difficult to stably store a PS of the photopolymerizable photosensitive layer of the PS plate having a photopolymerizable photoSensitive layer for plate is Severely damaged by development and the printing a long time Since free radical easily generates to initiate a durability of the PS plate is also deteriorated. chain polymerization reaction in the photopolymerizable 25 As a developer for a PS plate having a photopolymeriz photosensitive layer when the PS plate is exposed to light. able photoSensitive layer on an aluminum Substrate, an Accordingly, there has been a demand to obtain a PS plate aqueous Solution of Silicate, phosphate, carbonate or hydrox that can be Stably kept for a long time, especially under a ide of an alkali metal or organic amine compound has been high temperature and high humidity and that can provide a proposed. lithographic printing plate which does not cause any back For example, J.P. KOKAI No. Hei 8-248643 discloses a ground contamination. developer having a high pH of at least 12 and comprising an Many attempts have been made to eliminate the back alkali silicate and an amphoteric Surfactant. J.P. KOKAI No. ground contamination. For instance, the following PS plates Hei 11-65129 discloses a developer having a pH of 12 or or methods disclosed in various publications are known; a 35 lower, wherein the ratio SiO/MO (M is alkali metal) is PS plate comprising a basecoat layer consisting of polyvi Specified. nylphosphonic acid coated on a Surface of an anodized aluminum plate and a photoSensitive layer coated thereon The former developer having such a high pH has a further comprising a diazo compound (German Patent No. 1,621, problem, in addition to the handling problem, that an image 478), a PS plate comprising a basecoat layer of polyacrylic 40 area of the PS plate to be developed is easily damaged. The acid that is coated on an aluminum Substrate and a layer of latter developer has a problem that the contained Silicate diazo resin coated on the basecoat layer (German Patent No. easily gelates and becomes insoluble due to the decrease of 1,091,433), a PS plate comprising a basecoat layer of the pH of the developer during the development process. polyacrylamide and a photoSensitive layer coated thereon 45 A developer comprising no alkali Silicate is described, for (U.S. Pat. No. 3,511,661), and a method to add an organic example, in J.P. KOKAI No. Sho 61-109052. The patent acid polymer compound to a photoSensitive layer compris application discloses a developer comprising an alkaline ing a diaZO compound and organic polymer carrier to agent, a complexing agent, an anionic Surfactant, an emul improve the stability with time of a PS plate comprising the Sifying agent and n-alkanoic acid. Another example is photoSensitive layer, thereby inhibiting generation of a back 50 described in German Patent No. 1984.605 which discloses a ground contamination of the PS plate (Japanese developer comprising an alkaline agent, a complexing agent, Un-examined Patent Publication (hereunder referred to as an anionic Surfactant, amyl alcohol, and N-alkoxyamine. “J.P. KOKAI”) No. Sho 56-107238). However, these PS However, it is difficult to obtain a good printing performance plates are Still insufficient and a further improvement is 55 Such as printing durability Since both the developerS have required. J.P. KOKAI No. Sho 57-5042 discloses a photo high pH and comprise an organic Solvent which causes addition composition comprising a combination of a diaZo damages of image area. resin having plural diazonium groups on the Side chain and A developer having a relatively low pH (12 or less) with a Sulfonated polymer comprising plural Sulfonate groups no alkali silicate is described, for example, in J.PKOKAI (for example, Sulfonated polyurethane and Sulfonated 60 No.2000-81711 which discloses a developer comprising an polyester). However, the effect of the composition to inhibit aqueous Solution of potassium hydroxide comprising an the background contamination is not Sufficient and further, anionic Surfactant, and in J.P. KOKAINo. Hei 11-65126 that the utility of the PS plate is restricted since the performance discloses a developer comprising an aqueous Solution of of the plate is highly influenced by the Sulfonated polyure 65 alkali metal carbonate having a pH ranging from 8.5 to 11.5. thane or Sulfonated polyester used in the photoSensitive However, such a developer having a relatively low pH layer. poorly dissolves photopolymerizable photosensitive layer US 6,830,874 B2 3 4 and thus, may cause problems. Such as a remain of a film in DESCRIPTION OF THE PREFERRED a non-image area of the photoSensitive layer, particularly EMBODIMENTS when the utilized PS plate is an aged one (that is, the plate Hereinafter, the present invention is explained in detail. has been Stored for a long time after production). In order to (Intermediate Layer) Solve the problem, it is necessary to improve the develop One of the characteristics of the present invention is that ment performance by increasing an acid number of a binder an intermediate layer comprises a polymer compound com polymer in the photosensitive layer of the PS plate, or by use prising a Structure unit having an acid group and a structure of an additional monomer having an acid group in the binder unit having an onium group. The lithographic printing plate polymer. But, when Such a binder polymer having a higher 1O prepared from a PS plate comprising Such an intermediate acid number is used, it often causes a problem in a printing shows no background contamination even after it is kept for proceSS Such as a blinding, that is, ink does not adhere to the a long time and an improved printing durability. PS plate during the printing process. The polymer compound used in the present invention is SUMMARY OF THE INVENTION prepared by, for example, polymerizing at least a monomer 15 component comprising an acid group and a monomer com Thus, the purpose of the present invention is to provide a ponent comprising an onium group. A preferred example of method for making a lithographic printing plate which has a the acid group is that having an acid dissociation constant Stability with time and does not cause any background (pKa) of 7 or less. More preferable examples of the acid contamination when the plate is used to make printings after group include -COOH, -SOH, -OSOH, -POH, exposed to light and developed, and even when the plate is -OPOH, -CONHSO-, and -SO2NHSO-. Particu kept for a long time under a high temperature and high larly preferred group is -COOH. Preferred examples of the humidity. More Specifically, the purpose of the present onium group include those comprising atoms of group 5 or invention is to provide a PS plate useful for making a group 6 in the periodic table. More preferable examples of lithographic printing plate and to provide a preparation 25 onium group are those comprising nitrogen atom, phospho method therefor, wherein the lithographic printing plate rus atom, or Sulfur atom. Most preferable example is an shows a stable and good development performance even if onium group comprising nitrogen atom, i.e., ammonium the PS plate has been developed with an alkali developer grOup. having a relatively low pH preferably used from the view Preferably, the main chain of the polymer of the present point of environmental protection and Safety, and the litho invention is a vinyl polymer Such as acrylic resin, meth graphic printing plate shows an increased image strength acrylic resin and polystyrene, urethane resin, polyester or and causes no background contamination during printing polyamide. More preferably, the main chain of the polymer proceSS and no damage in the image area during develop is a vinyl polymer Such as acrylic resin, methacrylic resin ment process. 35 and polystyrene. A particularly preferred chain is a polymer The inventors of the present invention have found that a having a structure unit having an acid group, which is lithographic printing plate Shows a resistivity to background derived from the compound represented by the following contamination when the PS plate comprises an intermediate general formula (1) or (2) and a structure unit having an layer comprising a polymer comprising a structure unit onium group, which is derived from the compound repre having an acid group and a structure unit having an onium 40 sented by the following general formula (3), (4) or (5). group and the PS plate is developed with an developer comprising a Specific nonionic Surfactant in an aqueous (1) alkali Solution having a relatively low pH. In addition, R1 dissolution rate of non-exposed area of the photopolymer 45 izable photoSensitive layer is increased by the method and CHFC penetration of the developer is inhibited around the photo (A), (B) -(D)-X), (2) crosslinked image portion to thus give a Strong film. R1 Thus, the present invention provides a method for pre paring a lithographic printing plate which comprises image 50 CHFC wise exposing to light a presensitized plate useful for making a lithographic printing plate having an intermediate (A), (B), (G)-(D)-X layer and a photosensitive layer on an aluminum Substrate in (E) X this order and developing the imagewise exposed plate with 55 a developer, wherein Said intermediate layer comprises a In the above formula, A is a bivalent connecting group; B polymer compound comprising a structure unit having an is a bivalent, trivalent or tetravalent aromatic or Substituted acid group and a structure unit having an onium group and aromatic group; D and E each independently represents a Said developer comprises an inorganic alkali Salt and a bivalent connecting group; G is a trivalent connecting group; nonionic Surfactant having polyoxyalkylene ether group and 60 X and X each independently represents an acid group pH of the developer ranges from 11.0 to 12.7. having pKa of 7 or leSS or an alkali metal Salt or ammonium By Such a method, it becomes possible to obtain a salt thereof; R is a hydrogen atom, alkyl group or halogen lithographic printing plate that does not cause any back atom; “a”, “b”, “d” and “e” each independently represents 0 ground contamination even it is kept for a long time and 65 or 1; and “t' is 1 to 3. image portion of the plate becomes Strong film to thus give Preferably, A is -COO- or -CONH-; B is a phe a good printing durability and a resistance to a Solvent. nylene group or Substituted phenylene group wherein the US 6,830,874 B2 S 6 Substituent is a hydroxy group, halogen atom or alkyl group; -continued D and E each independently represents an alkylene group or CHFCH CHFCH a bivalent connecting group represented by the molecular N N formula of CHO, CHS, or CH, N, G is a trivalent 5 connecting group represented by the molecular formula of CH, CHO, CHS or CHN, wherein “n” is ex ex 1 to 12, X and X" each independently represents a carboxylic CHCHCOOH criticoot acid, Sulfonic acid, phosphonic acid, Sulfuric acid mono COOH ester or phosphoric acid mono ester; R is a hydrogen atom or alkyl group; “a”, “b”, “d” and “e” each independently CHFCH CHFCH represents 0 or 1, provided that “a” and “b” are not simul taneously 0. N N 15 A particularly preferred Structure unit having an acid ex ex group is a compound represented by the general formula (1), city cool choticoon wherein B is a phenylene group or Substituted phenylene CHCOOH CHCOOH group wherein the Substituent is a hydrogen group or C1 to C3 alkyl group; D and E each independently represents C1 or C2 alkylene group or C1 or C2 alkylene group which is connected through an oxygen atom; R is a hydrogen atom 1. COOH or methyl group; X is a carboxylic acid group; “a” is 0; and 25 “b is 1. Specific examples of the Structure unit having an acid group are shown below, but they are not limited thereto. 2. COOH (Specific Examples of the Structure Unit Having an Acid Group) 1. O Acrylic acid, methacrylic acid, crotonic acid, isocrotonic COO-CHCHC k DH)2 acid, itaconic acid, maleic acid, maleic anhydride, 35 1. COO- circucu-kot, CHFCH CHFCH CHFCH CHFCH CHFCH

40

COOH O=P(OH)2 SOH CH SONHCOCH OSONHCO CH 45 CHFCH CHFCH CHFC

50 --O- CHFCH COONa COONH' COOH CHFCH CHFCH CH3 COOH 55 losis-( ) COOH COOH 60 CHFCH CHFCH 1oss-( )—cil. N N CH

1. 1. O eX ex I 65 1son-- CH2-SOH CHCOOH CH2P(OH)2 CH US 6,830,874 B2 7 8 -continued Particularly preferred examples among the above are the CHFCH compounds wherein K is a phenylene group or Substituted phenylene group wherein the Substituent is a hydroxy group or C1 to C3 alkyl group; M is C1 or C2 alkylene group or C1 or C2 alkylene group connected via an oxygen group; Z. is a chloride ion or RSOs; R is a hydrogen atom or methyl group; "j" is 0; “k” is 1; and R is C1 to C3 alkyl group. Specific examples of the Structure unit having an onium losi-()-son 1O group are shown below, but they are not limited thereto. Hereinafter, the polymer comprising a structure unit hav (Specific Examples of the Structure Unit Having an Onium ing an onium group, which is derived from the compound Group) represented by the general formula (3), (4) or (5) will be explained. 15 CHFCH CHFCH (3) N N R2 ex ex cu- R3 CHN' Me Cl CHN'Eta Cl (j)-(K) (M) -Yi'-R' uz k CHFCH CHFCH (4) R2 25 Me cu- R6 Cex1. A. cle CI CHNEt3 CI (J)-(K) (M) -Y.,' uz Me 2 3 Y7 CHFCH CHFCH (5) R2 N N Me - ci- R3 2x1 \4 O Cl 2x / \ M CH51V / CH5-N C (J)-(K) (M) -Y.,' uz 35 y4 CHFCH CHFCH

In the formula, J is a bivalent connecting group; K is a N N bivalent, trivalent or tetravalent aromatic or a Substituted aromatic group; Mindependently represents a bivalent con 40 ex 1. necting group; Y is an atom of group 5 in the periodic table; CH2N(CH2CH2OH)3 CI Y is an atom of group 6 in the periodic table; Z is a counter CHFCH CHFCH anion; R is a hydrogen atom, alkyl group or halogen atom; R. R", Rand R7 each independently represents a hydrogen N N atom or an optionally Substituted alkyl group, aromatic 45 group, or aralkyl group; R is an alkylidene group or ex e substituted alkylidene group; R and R', or R and R7 may CHN'Et Br CHN'Et PF be linked together to form a ring; “j”, “k” and “m” each CHFCH CHFCH independently represents 0 or 1; and “u' is 1 to 3. 50 Preferably, J is -COO- or -CONH-; K is a phe N N nylene group or a Substituted phenylene group wherein the Substituent is a hydroxy group, halogen atom or alkyl group; 1. M is an alkylene group or a bivalent connecting group 2X 1. having the molecular formula of CHO, CHS or CHN'Et MeSO CH, N, wherein “n” is 1 to 12, Y is a nitrogen atom or 55 th th phosphorus atom; Y is a Sulfur atom, Z is a halogen ion, CHFC CHF PF, BF, or RSO; R is a hydrogen atom or alkyl group; R, R", R and R7 each independently represents a COOCH2CH2N' Me Cl hydrogen atom or optionally substituted C1 to C10 alkyl 60 r group, aromatic group, or aralkyl group; R is a C1 to C10 1. alkylidene group or Substituted alkylidene group; R and R', CHN'Eta Cl or Rand R may be linked together to form a ring; “j”, “k” th th and “m” each independently represents 0 or 1 provided that CHFC CHFC “j” and “k” are not simultaneously 0; and R is an optionally 65 Substituted C1 to C10 alkyl group, aromatic group, or CONHCHCHN' Me Cl COOCH2CH2NHMe) Cl aralkyl group. US 6,830,874 B2 9 10 -continued (5) acrylic acid esters or methacrylic acid esters having an CH CHFCH aliphatic hydroxy group, e.g., 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, CHFC N (6) (Substituted) acrylic ester Such as methyl acrylate, CONHCH2CHCHN' Me Cl ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, 2X -- hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl OH CHSEt NO acrylate, benzyl acrylate, 2-chloroethyl acrylate, CH2=CH 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate and the like, (7) (Substituted) methacrylic acid ester Such as methyl r 1. BF methacrylate, ethyl methacrylate, propyl methacrylate, butyl 2x -- 4 methacrylate, amyl methacrylate, hexyl methacrylate, cyclo CHS he Xyl methacrylate, octyl methacrylate, phenyl 15 methacrylate, benzyl methacrylate, 2-chloroethyl th methacrylate, 4-hydroxybutyl methacrylate, glycidyl CHFC -- methacrylate, N-dimethylaminoethyl methacrylate and the COOCH2CH2P(n-Bu) Cl like, (8) acrylamide or methacrylamide Such as acrylamide, me thacrylamide, N-methylol acrylamide, In addition, the polymer may further comprise as a N-methylolme thacrylamide, N-ethylacrylamide, copolymer component at least one polymerizable monomer N-ethylmethacrylamide, N-hexyl acrylamide, selected from the following (1) to (4); N-hexylmethacrylamide, N-cyclohexylacrylamide, (1) acrylamides, methacrylamides, acrylic acid esters, 25 N-cyclohexylmethacrylamide, N-hydroxyethylacrylamide, methacrylic acid esters and hydroxystyrenes having an aro N-hydroxyethylacrylamide, N-phenylacrylamide, matic hydroxy group Such as N-(4-hydroxyphenyl) N-phenylmethacrylamide, N-benzyl acrylamide, acrylamide or N-(4-hydroxyphenyl)methacrylamide, o-, m N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitro phenyl me thacrylamide, N-ethyl-N- or p-hydroxystyrene, o- or m-bromo-p-hydroxystyrene, o phenylacrylamide, N-ethyl-N-phenylmethacrylamide and or m-chloro-p-hydroxystyrene, o-, m- or p-hydroxyphenyl the like, acrylate or methacrylate and the like, (9) vinyl ethers such as ethyl vinyl ether, 2-chloroethyl (2) unsaturated carboxylic acid Such as acrylic acid, vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, methacrylic acid, maleic acid, maleic anhydride and a half 35 butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether and ester thereof, itaconic acid, and itaconic anhydride and a half the like, ester thereof, (10) vinyl esterS Such as Vinyl acetate, vinyl chloroacetate, Vinyl butyrate, Vinyl benzoate and the like, (3) unsaturated Sulfonamide of acrylamids Such as N-(o- (11) styrenes such as Styrene, C.-methylstyrene, a mino Sulfonyl phenyl) acrylamide, N- (m- 40 methylstyrene, chloromethylstyrene and the like, a mino Sulfonyl phenyl) acrylamide, N-(p- (12) vinyl ketones Such as methyl vinyl ketone, ethyl aminosulfonylphenyl)acrylamide, N-1-(3-aminosulfonyl) Vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone and naphthyl acrylamide, N-(2-aminosulfonylethyl)acrylamide the like, and the like; of methacrylamids such as N-(o- 45 (13) olefines Such as ethylene, propylene, isobutylene, a mino Sulfonyl phenyl)methacrylamide, N-(m- butadiene, isoprene and the like, and a mino Sulfonyl phenyl)methacrylamide, N-(p- (14) N-vinylpyrrollidone, N-vinylcarbazole, aminosulfonylphenyl)methacrylamide, N-1-(3- 4-Vinylpyridine, acrylonitrile, methacrylonitrile and the like. aminosulfonyl) naphthylmethacrylamide, N-(2- The polymer of the present invention desirably contains aminosulfonylethyl)-methacrylamide and the like; of acrylic 50 20% by mole or more and more preferably 40% by mole or acid esterS Such as O-aminosulfonylphenyl acrylate, more of the Structure unit having an acid group, and contains m-aminoSulfonylphenyl acrylate, p-aminoSulfonylphenyl 1% by mole or more and more preferably 5% by mole or acrylate, 1-(3-aminosulfonylphenylnaphthyl) acrylate and more of the Structure unit having an onium group. If the the like; and of methacrylic acid esterS Such as 55 polymer contains 20% by mole or more of the structure unit O - a mino Sulfonyl phenyl me thacrylate, having an acid group, dissolution of the polymer to the m - a mino Sulfonyl phenyl me thacrylate, alkaline developer will be promoted. If the polymer contains p - a mino Sulfonyl phenyl me thacrylate, 1- (3- 1% by mole or more of the Structure unit having an onium aminosulfonylphenylnaphthyl) methacrylate and the like, group, adhesiveness of the polymer is increased as a Syn 60 ergistic effect with the acid group. The polymer may com (4) phenylsulfonylacrylamide that may have a Substituent prise one or more structure units having an acid group and Such as tosylacrylamide and phenylsulfonylmethacrylamide the polymer may comprise one or more Structure units that may have a Substituent Such as tosylmethacrylamide. having an onium group. In addition, the polymer of the In addition to the monomers comprising an alkaline 65 present invention may be a mixture of two or more polymers Soluble group, the following film-forming resin prepared by that are different in its structure unit, ratio thereof or copolymerizing the monomer described in (5) to (14); molecular weight. US 6,830,874 B2 11 12 The followings are the representative polymers of the present invention. The number described in the structure unit represents mole percent.

Number average Structure molecular weight (Mn) No. 1 -(-CHCH-) - (-CHCH-) is 2,100

COOH CH'NEta Cl

No. 2 -(-CHCH-) - (-CHCH- -(-CHCH-) - 4,800

CH2NEt Cl COOH CH'NEta Cl

No. 3 -(-CHCH-) - (-CHCH 3,200

COOH CHNMe Cl

No. 4 -(-CHCH-) - (-CHCH 2,300 21 S X CH2'P(n-Bu)3 CI COOH

No. 5 -(-CHCH-) - (-CHCH 1,400 21 N X CH'S BF SOH No. 6 -(-CHCH-) - (-CHCH 4,500 21 S X CH'N(n-Bu), PF SONa No. 7 -(-CHCH-) - (-CHCH 5,000 C,Nix CNx CHP (OH)2 CHNMe Cl

US 6,830,874 B2

-continued Number average Structure molecular weight (Mn) No. 16 CH CH 3,000 - cursloss-( )—cil- curr-curCN COOCH2CH2'P(n-Bu)3Cl

No. 17 -(-CHCH-) - (-CHCH-) - (-CHCH- 3,300 21 21 N.X : lyX CHP(OH)2 CH'PPhs Cl COOH

No. 18 CH 6OO - curr -(-CHCH- -cuts COOH COOCHCH'PEta Cl losi-()-coon No. 19 - curs -tcl is -(-CHCH- 5,000 COOH dooCH,-( y 21 N X CH'N(n-Bu), Br No. 20 CH 2,400 -(-CHC- -(-CHCH-) -(-CHCH-). COOCH 21

losis-( )—cit N dCH2NEt3 I

45 Typically, the polymer of the present invention can be control the molecular weight of the polymer. The chain prepared by a radical chain polymerization method. See, transfer agent is a Substance that transfers the active point in “Textbook of Polymer Science” 3rd ed., (1984) F. W. the polymerization reaction by chain transfer reaction. The Billmeyer, A Wiley-Interscience Publication. The number occurrence of the transfer reaction is indicated by the chain average molecular weight (Mn) of the polymer of the 50 transfer constant, Cs. The chain transfer constant Csx10" (at present invention, that is calculated from the integrated 60° C) of the chain transfer agent used in the present intensity of the terminal group and functional group at Side invention is preferably 0.01 or higher, more preferably 0.1 or chain observed in NMR analysis, is in the range of 300 to higher and most preferably 1 or higher. A polymerization 5,000, preferably from 500 to 4,800 and more preferably initiator generally utilized in the radical polymerization Such from 800 to 4,500. If Mn is below 300, the adhesiveness of 55 as peroxide, azo compound and redox initiator can be the polymer to the Substrate becomes decreased to result in utilized. Among them, azo compound is particularly pre deterioration of the printing durability. If Mn is beyond ferred. 5,000, the adhesiveness to the Substrate becomes too strong Examples of chain transfer agents include halogenized to result in insufficient removal of the non-image area and to compounds Such as carbon tetrachloride, carbon tetrabro result in deterioration of cleaning property. The amount of 60 mide and the like, alcohols Such as isopropyl alcohol, the unreacted monomer in the polymer may be in a wide isobutyl alcohol and the like, olefines Such as 2-methyl-1- range but preferably up to 20% by weight and more pref butene, 2,4-diphenyl-4-methyl-1-pentene and the like, Sulfur erably up to 10% by weight. compounds Such as ethanethiol, butanethiol, dodecanethiol, When the polymer is prepared by copolymerizing the 65 mercap to ethanol, mercaptopropanol, methyl corresponding monomers, a polymerization initiator and/or mercaptopropionate, ethyl mercaptopropionate, mercapto chain transfer agent can be added to the reaction mixture to propionic acid, thioglycolic acid, ethyl disulfide, Sec-butyl US 6,830,874 B2 17 18 disulfide, 2-hydroxyethyl disulfide, thiosalicylic acid, (Photosensitive Layer) thiophenol, thiocreSol, benzylmercaptan, phenethylmercap The photopolymerizable photoSensitive layer usable in tan and the like, but not limited thereto. Preferred com the present invention is prepared from photopolymerizable pounds are ethanethiol, butanethiol, dodecanethiol, photosensitive composition (hereinafter, referred to as “pho mercap to ethanol, mercaptopropanol, methyl topolymerizable composition'). The photopolymerizable mercaptopropionate, ethyl mercaptopropionate, mercapto composition comprises an addition polymerizable or ethyl propionic acid, thioglycolic acid, ethyl disulfide, Sec-butyl enically unsaturated bond-containing compound, a photo disulfide, 2-hydroxyethyl disulfide, thiosalicylic acid, polymerization initiator, and a polymer binder, and option thiophenol, thiocreSol, benzylmercaptan, phenethylmercap ally comprises a variety of compounds Such as a coloring tan and the like, but not limited thereto. More preferred agent, plasticizer, heat polymerization inhibitor and the like. compounds are ethanethiol, butanethiol, dodecanethiol, The ethylenically unsaturated bond in the ethylenically mercap to ethanol, mercaptopropanol, methyl unsaturated bond-containing compound can be addition mercaptopropionate, ethyl mercaptopropionate, mercapto polymerized to cross-link or cure the compound when the propionic acid, thioglycolic acid, ethyl disulfide, Sec-butyl 15 photopolymerizable composition is exposed to active light. disulfide, and 2-hydroxyethyl disulfide. The compound comprising the addition polymerizable or The intermediate layer comprising the above polymer ethylenically unsaturated bond may be selected from the compounds can be coated on an aluminum Substrate by group consisting of compounds comprising at least one, various methods, which the Substrate has been previously preferably two or more terminal ethylenically unsaturated Subjected to treatment to obtain a hydrophilic Surface. bonds, which the compounds are in the form of, for example, For example, the intermediate layer can be coated by the a monomer, prepolymer (i.e., oligomer Such as a dimer and following methods. A Solution of the polymer compound trimer), copolymer and a mixture thereof. described above in an organic Solvent Such as methanol, Examples of the monomer and copolymer comprising an ethanol, and methyl ethyl ketone or a mixture thereof or in ethylenically unsaturated bond include an ester of unsatur a mixture of Said organic Solvent and water, is coated on an 25 ated carboxylic acid (e.g., acrylic acid, methacrylic acid, aluminum Substrate and then is dried. An aluminum Sub itaconic acid, crotonic acid, isocrotonic acid, and maleic Strate is immersed in a Solution of the polymer compound acid) and aliphatic polyol, and an amide of unsaturated described above in an organic Solvent Such as methanol, carboxylic acid and aliphatic polyamine. Examples of the ethanol, and methyl ethyl ketone or a mixture thereof or in ester of unsaturated carboxylic acid and aliphatic polyol a mixture of Said organic Solvent and water, and then is include an acrylic acid ester Such as ethylene glycol washed with water and/or air-dried. diacrylate, triethylene glycol diacrylate, 1,3-butanediol In the former method, a Solution comprising Said com diacrylate, tetramethylene glycol diacrylate, propylene gly pounds in a total amount of 0.005% to 10% by weight can col diacrylate, neopentyl glycol diacrylate, trimethylolpro be applied onto the aluminum Surface by a variety of pane triacrylate, trimethylolpropane tri(acryloyloxypropyl) methods. Examples of the method include bar coating, roll 35 ether, trimethylolethane triacrylate, hexanediol diacrylate, coating, spray coating, flood coating and the like. In the 1,4-cyclohexanediol diacrylate, tetraethylene glycol latter method, the concentration of the Solution may range diacrylate, pentaerythyritol diacrylate, pentaerythyritol from 0.005% to 20% by weight, preferably from 0.01% to triacrylate, pentaerythyritol tetraacrylate, dipentaerythyritol 10% by weight at the immersing temperature of 0°C. to 70 40 diacrylate, dipentaerythyritol pentaacrylate, dipentaerythy C., preferably from 5° C. to 60° C. for 0.1 second to 5 ritol hexaacrylate, Sorbitol triacrylate, Sorbitol tetraacrylate, minutes, preferably from 0.5 second to 120 seconds. Sorbitol pentaacrylate, Sorbitol hexaacrylate, tri The pH of the solution for the intermediate layer can be (acryloyloxyethyl)isocyanulate, polyester acrylate oligomer controlled by adding to the Solution the following materials, and the like. a basic compound Such as ammonia, triethylamine, and 45 Examples of methacrylic acid ester include tetramethyl potassium hydroxide, an inorganic acid Such as hydrochloric ene glycol dime thacrylate, triethylene glycol acid, phosphoric acid, Sulfuric acid and nitric acid, an dimethacrylate, neopentyl glycol dimethacrylate, trimethy organic acidic compound, e.g., an organic Sulfonic acid Such lolpropane trimethacrylate, trimethylolethane methacrylate, as nitrobenzeneSulfonic acid, naphthaleneSulfonic acid, an ethylene glycol dimethacrylate, 1,3-butanediol organic phosphonic acid Such as phenylphosphonic acid, 50 dimethacrylate, hexanediol dimethacrylate, pentaerythyritol and an organic carboxylic acid Such as benzoic acid, fumaric dimethacrylate, pentaerythyritol trimethacrylate, pen acid, and malic acid, and an organic chloride Such as taerythyritol tetramethacrylate, dipentaerythyritol naphthaleneSulfonyl chloride, and benzeneSulfonyl chloride. dimethacrylate, dipentaerythyritol hexamethacrylate, dipen The pH of the solution may range from 0 to 12 and 55 taerythyritol pentamethacrylate, Sorbitol trimethacrylate, preferably from 0 to 6. The solution may further comprise a Sorbitol tetramethacrylate, bisp-(3-methacryloxy-2- material that absorbs ultraviolet light, visible light or infra hydroxypropoxy)phenyldimethylmethane, bis-p- red radiation to improve a property as to tone reproduction (methacryloxyethoxy)phenyldimethylmethane and the like. of the PS plate. Examples of itaconic acid ester include ethylene glycol The total amount of the compound that makes up the 60 ditaconate, propylene glycol ditaconate, 1,5-butanediol intermediate layer after being dried ranges Suitably from 1 ditaconate, 1,4-butanediol ditaconate, tetramethylene gly Mg/m to 100 mg/m, and preferably from 2 mg/m to 70 col ditaconate, pentaerythyritol ditaconate, Sorbitol tet mg/m. If the coating amount is below 1 mg/m, the inter raitaconate and the like. mediate layer does not work well. If the coating amount is 65 Examples of crotonic acid ester include ethylene glycol beyond 100 mg/m, also the intermediate layer does not dicrotonate, tetramethylene glycol dicrotonate, pentaerythy work well. ritol dicrotonate, Sorbitol tetradicrotonate and the like. US 6,830,874 B2 19 20 Examples of isocrotonic acid ester include ethylene glycol No. Sho 54-155292); a system comprising a cyclic cis-O- diisocrotonate, pentaerythyritol diisocrotonate, Sorbitol tet dicarbonyl compound and a dye (J.P. KOKAI No. Sho raisocrotonate and the like. 48-84-183); a System comprising a Substituted triazine and a Examples of maleic acid ester include ethylene glycol merocyanine dye (J.P. KOKAI No. Sho 54-15102); a system dimaleate, triethylene glycol dimaleate, pentaerythyritol comprising a 3-keto-Substituted coumarin compound and an dimaleate, Sorbitol tetramaleate and the like. Further, mix active halogen atom-containing compound (J.P. KOKAI No. tures of the aforementioned ester monomers are also Sho 52-112681, J.P. KOKAI No. Sho 58-15503); a system included. comprising biimidazole, styrene derivative, and thiol (J.P. Examples of amide of aliphatic polyamine compound and KOKAI No. Sho 59-140203); a system comprising an unsaturated carboxylic acid include methylenebis organic peroxide compound and a pigment (J.P. KOKAI No. acrylamide, methyleneb is methacrylamide, 1,6- Sho 59-1504, J.P. KOKAI No. Sho 59-140203, J.P. KOKAI he X a methylene bis-acrylamide, 1, 6 - No. Sho 59-189340, J.P. KOKAI No. Sho 62-174203, J.P. he X a methylene biS me thacrylamide, KOKOKU No. Sho 62-1641, U.S. Pat. No. 4,766,055); a diethylenetriaminetrisacrylamide, Xylylenebisacrylamide, 15 System comprising a dye and an active halogenated com Xylylenebismethacrylamide and the like. Other examples pound (J.P. KOKAI No. Sho 63-258903, J.P. KOKAI No. include Vinylurethane compound comprising two or more Hei 2-63054 and the like); a system comprising a dye and a polymerizable vinyl groups in a molecule, prepared by an borate compound (J.P. KOKAI No. Sho 62-143044, J.P. addition reaction of a vinyl monomer having a hydroxyl KOKAI No. Sho 62-150242, J.P. KOKAI No. Sho group represented by the following formula (A) with a 64-13140, J.P. KOKAI No. Sho 64-13141, J.P. KOKAI No. polyisocyanate compound having two or more isocyanate Sho 64-13142, J.P. KOKAI No. Sho 64-13143, J.P. KOKAI groups as disclosed in Japanese Patent Publication for No. Sho 64-13144, J.P. KOKAI No. Sho 64-17048, J.P. Opposition Purpose (hereunder referred to as “J.P. KOKAI No. Hei 1-229003, J.P. KOKAI No. Hei 1-298348, KOKOKU”) No. Sho 48-41708. 25 J.P. KOKAI No. Hei 1-138204 and the like); a system comprising a dye having a rhodanine ring and a radical generator (J.P. KOKAI No. Hei 2-179643, J.P. KOKAI No. wherein R and R' each represents H or CH. Hei 2-244.050); a System comprising a titanocene and Also, urethane acrylates as described in J.P. KOKAI No. 3-keto-substituted coumarin compound (J.P. KOKAI No. Sho 51-37193, J.P. KOKOKU No. Hei 2-32293, polyfunc Sho 63-221110); a System comprising titanocene, Xanthene tional acrylates or methacrylates Such as epoxycrylate pre dye, and an addition polymerizable compound having an pared from epoxy resin and (meth)acrylic acid, and polyester ethylenically unsaturated bond and an amino group or a acrylates as described in J.P. KOKAI No. Sho 48-64183, J.P. urethane group (J.P. KOKAI No. Hei 4-221958, J.P. KOKAI KOKOKU No. Sho 49-43191, and J.P. KOKOKU No. Sho 35 No. Hei 4-219756); a system comprising a titanocene and a 52-30490, can be utilized as the compound comprising an specific merocyanine dye (J.P. KOKAI No. Hei 6-295061); ethylenically unsaturated bond. In addition, a photo-Setting and a System comprising a titanocene and a dye having a monomer and oligomer as described in “Bulletin of Japan benzopyran ring (J.P. KOKAI No. Hei 8-334897). Adhesive Association Vol.20, No.7, p. 300-308 (1984)” can In addition, a laser having a wavelength ranging from 400 be utilized. The amount of the ethylenically unsaturated 40 nm to 410 nm (violet laser) has been developed and also, a bond-containing compound ranges 5% to 80% by weight photoinitiation System highly Sensitive to the wavelength of and preferably from 30% to 70% by weight on the basis of 450 nm or shorter has been developed. Therefore, such a the total weight of the photoSensitive layer. photoinitiation System also can be utilized. Examples The initiator of photopolymerization usable in the pho 45 thereof include a System comprising a cationic dye/borate tosensitive layer in the PS plate of the present invention can (J.P. KOKAI No. Hei 11-84.647), a system comprising a be selected from various initiators of photopolymerization merocyanine dye/titanocene (J.P. KOKAI No. 2000 reported in many patents and publications, or from various 147763), a System comprising a carbazole dye/titanocene combinations of two or more initiators of photopolymeriza (Japanese Patent Application No. Hei 11-221480) and the tion (photoinitiation System), depending on the wavelength 50 like. In particular, a System comprising a titanocene com of the light source to be used. Specific examples thereof will pound is preferably used in the present invention in View of be described below, but not limited thereto. its high Sensitivity. There have been proposed various photoinitiation Systems In the present invention, any titanocene compound can be which can be used for visible light rays having 400 nm or 55 utilized, but a Suitable titanocene compound can be Selected longer, Ar laser, Secondary harmonics of Semiconductor from various titanocene compounds including, for example, laser, or SHG-YAG laser as a light Source. For instance, a those described in J.P. KOKAI No. Sho 59-152396 and J.P. certain dye capable of being photolytically reduced Such as KOKAI No. Sho 61-151197. More specifically, examples of Rose Bengale, Eosine, and Erythrosine (U.S. Pat. No. 2,850, the titanocene compound include di-cyclopentadienyl-Ti-di 445); a combination System of a dye and an initiator Such as 60 chloride, di-cyclop ent a die nyl-Ti-bis-phenyl, a combined initiator System comprising a dye and an amine di-cyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, (J.P. KOKOKU No. Sho 44-20189); a system comprising di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, hexaarylbiimidazole, a radical initiator and a dye (J.P. di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1-yl, KOKOKU No. Sho 45-37377); a system comprising a 65 di-cyclopentadienyl-Ti-bis-2,6-di-fluorophen-1-yl, hexaarylbiimidazole and a p-dialkylaminobenzylidene di-cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, ketone (J.P. KOKOKU No. Sho 47-2528 and J.P. KOKAI di- methylcyclopen tadienyl-Ti-bis-2,3,4,5,6- US 6,830,874 B2 21 22 tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6- 2. “i” and “h” each represents 0 or 1. “1” represents 1 or 2. difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6'-difluoro j” and “k” each represents 0, 1, 2 or 3. X represents a 3-(pyr-1-yl)-phen-1-yl and the like. counter anion. Preferred dyes to be used with the titanocene compound include cyanine dyes, merocyanine dyes, Xanthene dyes, 5 p ketocoumarin dyes, and benzopyran dyes. A preferred cya 1. nine dye is represented by the following formula, but not 7& SN2 n.1" limited thereto. 7. CC, , , 1O N o- NR18 11 13 R R Rl, O4 - - - N. N -

z )=ch- CHE ch–K 2? 15 In the above formula, R'' and R', each independently R12 (X)n R14 represents a hydrogen atom, alkyl group, Substituted alkyl group, alkenyl group, Substituted alkenyl group, alkynyl wherein Z' and Z are the same or different and represent a group, Substituted alkynyl group, alkoxycarobonyl group, nonmetallic atom necessary to form a benzimidazole or naphthoimidazole ring; R', R', R' and R' each repre aryl group, Substituted aryl group or aralkyl group. Z Sents an optionally Substituted alkyl group; X represents a represents an oxygen atom, Sulfur atom, Selenium atom, counter anion and “n” represents 0 or 1. tellurium atom, alkyl or aryl-Substituted nitrogen atom, or Specific embodiments of cyanine dyes are shown in Table dialkyl-substituted carbon atom. Z represents non-metallic 1. atoms necessary to form a heterocyclic 5-membered ring

TABLE 1. R11 R13 1. A3 A. NX=CH-CH=CH-4 N A2 N (X)n N+ A4 R12 k

R11 R12 R13 R14 A" A? A. X CHs CHs CHs CHs C C Cl C 1. CHs CHs CHs CHs H CF, H CF, 1. CHs (CH)SO Na CH (CH)SO, CI Cl Cl C

Preferred examples of merocyanine dyes are shown containing a nitrogen atom. B' represents a substituted below, but not limited thereto. 45 phenyl group, unsubstituted or Substituted polynuclear aro matic ring, or unsubstituted or Substituted heteroaromatic ---- Z--- f Q ring. B represents a hydrogen atom, alkyl group, Substituted R-N-(-CH=CH-C=EL-L-FQ15- 1-T 2 p=EL-L's3--T 4 FL5-8: alkyl group, aryl group, Substituted aryl group, aralkyl J , f group, alkoxyl group, alkylthio group, arylthio group, Sub Aro 50 Stituted amino group, acyl group, or alkoxycarobonyl group, (X)m O l ---- Z--- or B and B may be linked together to form a ring. w w : Examples of merocyanine dyes are shown below. 55 In the above formula, Z and Z' each represents a non-metallic atomic group necessary for forming a Y C o S O 5-membered and/or 6-membered nitrogen-containing het CHO N 60 erocyclic ring that is typically contained in cyanine dyes. CH - O R" and Reach represents an alkyl group. Q and Q are --, atomic groups necessary for forming 4-thiazolinone ring, CH5 CH5 5- thia Zolin one ring, 4-imidazolidin one ring, 4-oxazolid in one ring, 5-oxazolid in one ring, 65 CH SOs 5-imidazolidinone ring or 4'-dithiolanone ring. L', L,L,L' and Leach represents methine group. “m” represents 1 or US 6,830,874 B2 23 -continued -continued O S S CH 1 3 S O N N S N X=CH-( CH CH or N S CHAOC Ho C2H5 C2H5 OCH3 1O O e

O 15 S O O S N X=CH-4 N 1Na or e N S CHs CHs CH

CH SO -O- O 25

-CH3 N N O | CHO S N n CH-CH S O XECH-K 1-4 CHs N C N S or s CHs CH5 Clop 35 O CH O S 1-421 40 Examples of Xanthene dyes include rhodamine B, N S rhodamine 6G, ethyleosin, alcohol-Soluble eosin, pyronine C7H15 Y, pyronine B and the like. Preferred examples of ketocoumarin dyes are shown below, but not limited thereto. O 45 R19 R24 R20 R25 O N S 50 21 N R na N O O N S H le R23 C8H17 55 In the above formula, R', R and R' each indepen O dently represents a hydrogen atom, halogen atom, alkyl O group or alkoxyl group, R and Reach represents alkyl CH S CH group, provided that at least one group represents alkyl 1. 215 N group having 4 to 16 carbon atoms, R' represents a 60 hydrogen atom, alkyl group, alkoxyl group, acyl group, N S cyano group, carboxyl group or ester or amide derivative C8H17 thereof, R represents a residue of the heteroaromatic ring, having 3 to 17 total carbon atoms and is represented by O 65 -CO-R, RandR and/or R’ and R may be bonded together to form a ring, and R represents the following groupS. US 6,830,874 B2 26 R", or -Z'-R, wherein Z represents a carbonyl group, R24 R19 Sulfonyl group, Sulfinyl group or arylene dicarbonyl group. R20 Alternatively, R and R together may form a ring con R’: alkoxy, 21 sisting of non-metallic atoms. Z7 represents O, S, NH or R21 nitrogen atom comprising a Substituent thereon. O O N R23 R22 Z represents the following group:

1O Examples of ketocoumarin dyes are shown below. V

N

N 15 N wherein G' and G may be the same or different and H represent a hydrogen atom, cyano group, alkoxycarobonyl group, aryloxycarbonyl group, acyl group, arylcarbonyl group, alkylthio group, arylthio group, alkylsulfonyl group, arylsulfonyl group or fluorosulfonyl group, but G' and G' do not represent hydrogen atom simultaneously. In addition, G' N-CION and G may form a ring consisting of non-metallic atoms together with a carbon atom. (C8H17)2N O O COO(t)C Ho N 25 Examples of benzopyran dyes are shown below.

N O O CH N CF C2H5- CN N O M N C2H5 CN CH N O O N

C2H5- CN 40 A O C2H5 CO2C2H5 CH

N O 45 CH5 CHs Preferred examples of benzopyran dyes include the com n N O N 1. pounds represented by the following formula, but are not / limited thereto. CH5 OCH O O 50 R30 R31 CH5 CH R29 N R32 N O

R28 Z7 78 C2H5 C2H5 n N O N 1. R27 / C2H5 In the above formula, R7, RandR are independently O S chosen from a hydrogen atom, halogen atom, alkyl group, 60 C2H5 aryl group, hydroxyl group, alkoxyl group and amino group. N Also, R7, R and R may form a ring consisting of non-metallic atoms together with the carbon atoms bonded CN H3CO thereto. R represents a hydrogen atom, alkyl group, aryl 65 group, heteroaromatic group, cyano group, alkoxyl group, CH COCHs carboxyl group or alkenyl group. R' represents a group of US 6,830,874 B2 27 28 -continued and the like. Examples of a functional group which becomes N a free radical upon exposure to light include mercapto group, thiol group, halogen atom, triazine Structure, onium Salt CN Structure and the like. In addition, examples of a polar group H3CO S that may be present in the binder polymer compound include CN carboxyl group, imide group and the like. In particular, ethylenically unsaturated groups Such as acrylic group, Moreover, it is known that a photoinitiation activity of the methacrylic group, allyl group, and Styryl group are pre above described photopolymerization initiator can be ferred as an addition polymerizable functional group. Also, improved by optionally adding to the initiator a hydrogen a functional group Selected from the group consisting of donating compound Such as thiol compounds, e.g., amino group, hydroxyl group, phosphonic acid group, phos 2-mercaptobenzthiazole, 2-mercaptobenzimidazole, and phoric acid group, carbamoyl group, isocyanate group, 2-mercaptobenzoxazole, and amine compounds, e.g., ureide group, ureylene group, Sulfonic acid group, and N-phenylglycine, N,N-dialkylaminoarylcarboxylic acid 15 ammonio group can be utilized. alkyl ester. In order to maintain the development performance of the The amount of the photopolymerization initiator (or composition, the binder polymer compound used in the system) to be used ranges from 0.05 to 100 parts by weight, present invention preferably has a Suitable molecular weight preferably from 0.1 to 70 parts by weight, and more pref and a Suitable acid number. That is, a polymer compound erably from 0.2 to 50 parts by weight, per 100 parts by having a weight average molecular weight ranging from weight of ethylenically unsaturated bond-containing com 5,000 to 300,000 and having an acid number ranging from pound. 20 to 200 may be effectively utilized. These organic polymer The binder polymer used in the photosensitive layer of the compounds can be utilized in the photopolymerizable com PS plate of the present invention should be a film-forming 25 position in any Suitable amount. However, if the amount material as well as an alkali developer-Soluble material. thereof exceeds 90% by weight, undesirable problems Therefore, an organic polymer compound that is Soluble or would be caused. For instance, the formed image may have Swellable in an alkali water may be used. Thus, if a water an insufficient Strength. The amount thereof is preferably Soluble organic polymer is used, a photopolymerizable com from 10% to 90% by weight and more preferably from 30% position can be developed with water. Examples of Such an to 80% by weight. The weight ratio of the photopolymer organic polymer compound that is soluble or Swellable in an izable ethylenically unsaturated compound to the organic alkali water include addition polymers having carboxyl polymer compound is preferably from 1/9 to 9/1, more groups on the Side chains Such as methacrylic acid preferably from 2/8 to 8/2 and 7/3 and further preferably copolymers, acrylic acid copolymers, itaconic acid 35 from 3/7 to 7/3. copolymers, crotonic acid copolymers, maleic acid Moreover, the photoSensitive layer usable in the present copolymers, and partially esterified maleic acid copolymers invention may preferably comprise a Small amount of a heat as disclosed in J.P.KOKAI Nos. Sho 59-44615, 54-92723, polymerization inhibitor, in addition to the principal com 59–53836 and 59-71048, and J.P.KOKOKU Nos. 54-34327, 40 ponents described above, to inhibit unnecessary heat poly 58-12577 and 54-25957. merization of the polymerizable ethylenically unsaturated Also, an acidic cellulose derivative having a carboxyl bond-containing compound during the preparation of the group on the Side chain can be utilized in the binder polymer photoSensitive composition or Storage thereof. Specific of the present invention. In addition, a polymer that is examples of the heat polymerization inhibitor effectively formed by adding a cyclic acid anhydride to an addition 45 used are hydroquinone, p-methoxyphenol, di-t-butyl-p- polymer having a hydroxyl group can be used. Among these creSol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'- compounds, benzyl (meth) acrylate/(meth) acrylic acid/ thiobis(3-methyl-6-t-butylphenol), 2,2'-methylenebis(4- other optional addition-polymerizable vinyl monomer methyl-6-t-butylphenol), N-nitrosophenylhydroxylamine copolymers and allyl (meth)acrylate/(meth)acrylic acid/ cerium Salt, and N-nitrosophenylhydroxylamine aluminum other optional addition-polymerizable vinyl monomer 50 Salt. copolymers are preferred. In addition, polyvinyl pyrrollidone The amount of the heat polymerization inhibitor based on and polyethylene oxide are useful as a water-Soluble organic the total weight of the photoSensitive composition is pref polymer. Alcohol-Soluble polyamides and polyetherS Such as erably from about 0.01% to about 5% by weight. Also, if a reaction product of 2,2-bis-(4-hydroxyphenyl)-propane 55 necessary, a higher fatty acid derivative Such as behenic acid with epichlorohydrin are also useful for the improvement of and behenic acid amide may be added to the photosensitive the Strength of the cured film. In addition, polyurethane composition to inhibit the blocking of polymerization by resins described in J.P. KOKOKU Nos. Hei 7-120040, Hei oxygen. The higher fatty acid derivative may be distributed 7-120041, Hei 7-120042, Hei 8-12424, J.P. KOKAI Nos. on the Surface of the photosensitive layer during the drying Sho 63-287944, Sho 63-287947, Hei 1-271741, and Hei 60 process after the application process. The amount of the 11-352691 are also useful in the present invention. higher fatty acid derivative is preferably in the range of The strength of the cured film can be increased by about 0.5% to about 10% by weight based on the total introducing a radical reactive group into the Side chain of the weight of the photoSensitive composition. above-described organic polymer compound. 65 In addition, a coloring agent may be added to the photo Examples of the addition polymerizable group include Sensitive layer to color the layer. Examples of the coloring ethylenically unsaturated group, amino group, epoxy group agent include phthalocyanine pigments (C. I. Pigment Blue US 6,830,874 B2 29 30 15:3, 15:4, 15:6 and the like), azo pigments, carbon black, from Kuraray Co. Ltd.) and the like. Examples of the titanium oxide pigments, ethyl violet, crystal violet, azo copolymer include a copolymer of polyvinyl acetate, poly dyes, anthraquinone dyes, and cyanine dyes. The amount of Vinyl chloroacetate, polyvinyl propionate, polyvinyl formal the dyes or pigments preferably ranges from about 0.5% to or polyvinyl acetal and copolymers thereof, which are about 20% by weight on the basis of the total weight of the Saponified to a degree of 88% to 100%. In addition, photosensitive composition. Additionally, in order to examples of the other useful polymers for the protective improve the property of the formed film, an additive such as layer include polyvinylpyrrolidone, gelatin, and gum arabic. an inorganic filler and plasticizer, e.g., dioctyl phthalate, The polymers can be used alone or in a combination. dimethyl phthalate and tricresyl phosphate, can be added. A Solvent to be used for coating the protective layer The amount of the additive is preferably 10% by weight or having an oxygen-barrier property is preferably pure water. leSS based on the total weight of the photosensitive compo But, a blend of pure water and alcohols such as methanol and Sition. ethanol and/or ketones Such as acetone and methyl ethyl The photosensitive composition used for the PS plate of ketone may be utilized. The amount of the solid in the the present invention may be dissolved in a variety of 15 coating solution suitably ranges from 1% to 20% by weight. organic Solvents when the composition is applied onto the In addition, the protective layer having an oxygen-barrier foregoing intermediate layer. Examples of the organic sol property may comprise known additives such as a surfactant Vents include acetone, methyl ethyl ketone, cyclohexane, to improve an application property of the layer and a ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, plasticizer to improve a film property. As an aqueous ethylene glycol monomethyl ether, ethylene glycol mono plasticizer, for example, propionamide, cyclohexanediol, ethyl ether, ethylene glycol dimethyl ether, propylene glycol glycerin, Sorbitol and the like may be added. Also, aqueous monomethyl ether, propylene glycol monoethyl ether, (meth)acrylic polymers can be added. The amount of the acetylacetone, cyclohexanone, diacetonealcohol, ethylene additives after being dried suitably ranges from about 0.1 glycol monomethyl ether acetate, ethylene glycol ethyl ether 25 g/m to about 15 g/m, and preferably from about 1.0 g/m acetate, ethylene glycol monoisopropyl ether, ethylene gly to about 5.0 g/m. col monobutyl ether acetate, 3-methoxypropanol, (Aluminum Substrate) methoxymethoxyethanol, diethylene glycol monomethyl The aluminum Substrate usable in the present invention ether, diethylene glycol monoethyl ether, diethylene glycol will be described. The aluminum substrate usable in the dimethyl ether, diethylene glycol diethyl ether, propylene present invention desirably consists of an aluminum having glycol monomethyl ether acetate, propylene glycol mono a high dimensional stability, an alloy thereof with silicon, ethyl ether acetate-3-methoxypropyl acetate, N,N- copper, manganese, magnesium, chromium, zinc, lead, bis dimethylformamide, dimethylsulfoxide, Y-butyrolactone, muth or nickel, or a plastic film or a paper which is methyl lactate, ethyl lactate and the like. The solvent can be 35 laminated or deposited with an aluminum or aluminum alloy used alone or in a combination. A Suitable concentration of Generally, the thickness of the Substrate ranges from about the Solid in the coating solution ranges from 1% to 50% by 0.05 mm to about 1 mm. Besides, a composite sheet as weight. disclosed in J.P. KOKAI No. Sho 48-18327 is also prefer The photopolymerizable composition used for the photo ably used in the present invention. sensitive layer of the PS plate of the present invention may 40 The aluminum Substrate used in the present invention further comprise a Surfactant to improve the property of the preferably has the Surface roughness ranging from 0.2 to coated Surface. The amount the Surfactant in the photosen 0.55 um. In order to obtain the roughness of the surface in sitive layer suitably ranges from about 0.1 g/m to about 10 Such a range, the Substrate is Surface-treated as described g/m, preferably from 0.3 g/m to 5 g/m, and more pref 45 hereinafter. erably from 0.5 g/m to 3 g/m, based on the dried weight In the present specification, the term "surface roughness” of the photosensitive layer. or “roughness of the Surface” of the aluminum substrate A protective layer having an oxygen-barrier property can means centerline average roughness (arithmetic mean be optionally applied onto the layer of the photopolymeriz roughness) (Ra) determined at right angles with the alumi able composition on a Substrate for eliminating the 50 num rolling direction. Ra is defined by the following for polymerization-inhibitory effect of oxygen in the air. mula and expressed in um. Examples of a water-Soluble vinyl polymer comprised in Such a protective layer having an oxygen-barrier property include polyvinyl alcohol, partial ester, ether, or acetal 55 thereof and a copolymer thereof comprising a substantial amount of unsubstituted vinyl alcohol unit that makes the In the formula, L is a measured length in the direction of compounds water-soluble. Examples of the polyvinyl alco centerline of roughness curve which is obtained using a hol include those having a degree of saponification of 71% probe (feeler), and the roughness curve is expressed as to 100% and a degree of polymerization of 300 to 2400. 60 Y=f(X), wherein X is an axis of centerline and Y is an axis Specific examples thereof include PVA-105, PVA-110, in the direction rectangular to X axis. The determination of PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, Land the average roughness is conducted as described in JIS PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-204, PVA B 0601. 205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, 65 (Surface Graining) PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, Preferred Surface graining methods of aluminum plates PVA-224E, PVA-405, PVA-420, PVA-613, L-8 (available include mechanical Surface graining, chemical etching, and US 6,830,874 B2 31 32 electrolytic graining as disclosed in J.P. KOKAI No. Sho Among the anodization treatments, particularly a method 56-28893. The surface graining methods further include, for to anodize in Sulfuric acid using a high current density instance, an electrochemical graining in an electrolyte Such described in U.K. Patent No. 1,412,768, and a method to as hydrochloric acid or nitric acid, and a mechanical grain anodize using phosphoric acid as an electrolyte described in ing such as a wire brush graining wherein an aluminum U.S. Pat. No. 3.511,661 are preferred. surface is scrabbled with a metal wire, a ball graining The amount of the anodized layer is preferably in the wherein an aluminum surface is grained with an abrasive range of 1 g/m to 10 g/m. If it is less than 1 g/m, the ball and abrasive, a brush graining wherein an aluminum resulting lithographic printing plate has insufficient printing surface is grained with a nylon brush and abrasive. durability and the non-image portion thereof is easily dam Moreover, these methods can be used alone or in a combi aged. If it is higher than 10 g/m, it requires a large amount nation. Among them, a suitable Surface graining method of electricity to produce the plate to result in an economical used in the present invention is the electrochemical method disadvantage. More preferable amount ranges from 1.5 g/m wherein the surface is grained chemically in an electrolyte to 7 g/m and most preferably from 2 g/m to 5 g/m. such as hydrochloric acid or nitric acid with an electric Moreover, the aluminum plate may be subjected to a current density ranging from 100C/dm to 400 C/dmf. More 15 sealing treatment after the Surface-graining and anodization specifically, electrolysis is preferably conducted in 0.1% to treatments. Such a sealing treatment is performed by 50% of hydrochloric acid or nitric acid at 20° C. to 100° C. immersing the aluminum plate in a hot water or a hot for 1 second to 30 minutes with an electric current density aqueous solution containing an inorganic or organic Salt or ranging from 100 C/dm to 400 C/dm. by treating the plate in a steam bath. In addition, the The thus grained aluminum Substrate may be further aluminum plate may be further Subjected to other treatments chemically etched with an acid or an alkali. It is not such as a surface treatment with an alkali metal silicate and industrially advantageous to use an acid as an etching agent a dipping treatment to dip the Substrate into an aqueous since it takes a long time to destroy the micro structure of the solution comprising a potassium fluorozirconate or a phos plate, but use of an alkali as the etching agent Solves this 25 phonic acid salt. problem. The PS plate of the present invention can be prepared by Suitable alkali agents usable in the present invention forming the intermediate layer and the photosensitive layer include sodium hydroxide, Sodium carbonate, Sodium described above on the thus surface-treated aluminum Sub aluminate, sodium metasilicate, Sodium phosphate, potas strate in this order. sium hydroxide and lithium hydroxide. A preferable con Hereinafter, the method for making a lithographic printing centration of the alkali agent ranges from 1% to 50% and a preferable temperature for the treatment with the alkali agent plate of the present invention will be specifically described. ranges from 20 to 100° C. In addition, a preferred condition The PS plate described above is imagewise exposed to light for the treatment can be selected so that an amount of the and then, developed with a developer comprising an inor dissolved aluminum becomes in the range of 5 g/m to 20 35 ganic alkali salt and a nonionic Surfactant comprising a g/m. polyoxyalkylene ether group and having pH of 11.0 to 12.7 In order to remove a Smut remained on the etched Surface and preferably of 11.5 to 12.5. The novel developer utilized of an aluminum plate, the plate may be washed with an acid. in the present invention will be described below. Examples of the acid to be used include nitric acid, Sulfuric 40 (Developer) acid, phosphoric acid, chromic acid, hydrofluoric acid and The developer used in the method for making a litho fluoboric acid. In particular, preferred Smut-removing meth graphic printing plate of the present invention comprises at ods after electrochemical Surface graining include a method least one inorganic alkali Salt and at least one nonionic to contact the plate with 15% to 65% by weight of sulfuric surfactant having polyoxyalkylene ether group. In addition, acid solution at 50 to 90° C. as disclosed in J.P. KOKAI No. 45 the developer has a pH ranging from 11.0 to 12.7. Sho 53-12739, and a method of alkali etching as disclosed Examples of the inorganic alkali Salt include any alkali in J.P. KOKOKU No. Sho 48-28.123. agent, preferably those having the above-described property. (Anodization) Specific examples thereof include inorganic alkali agents The thus treated aluminum substrate is preferably further such as sodium hydroxide, potassium hydroxide, ammo subjected to an anodization treatment. The anodization can 50 nium hydroxide, lithium hydroxide, Sodium silicate, potas be conducted by any conventional method known in the art. sium silicate, ammonium silicate, lithium silicate, trisodium More specifically, an anodized layer can be formed on the phosphate, tripotassium phosphate, triammonium surface of an aluminum Substrate by passing a direct or alternating current therethrough in an aqueous Solution or phosphate, sodium carbonate, potassium carbonate, ammo non-aqueous solution (i.e., in an electrolyte) comprising 55 nium carbonate, sodium bicarbonate, potassium sulfuric acid, phosphoric acid, chromic acid, oxalic acid, bicarbonate, ammonium bicarbonate, Sodium borate, potas sulfamic acid, benzenesulfonic acid or a combination sium borate, and ammonium borate. The alkali agent can be thereof. alone or in a combination. The conditions for the anodization can be variously When a silicate is used, the development performance of changed depending on the kind of the electrolyte used. But, 60 the developer can be easily controlled by changing the in general, the anodization is preferably performed in an mixing ratio of silicon dioxide SiO2 and alkali metal oxide electrolyte having a concentration ranging from 1% to 80% MO wherein M is alkali metal or ammonium group and by by weight, at a temperature ranging from 5 to 70° C., with changing the concentration thereof a current density ranging from 0.5 A/dm to 60 A/dM2 and 65 The molar ratio of said silicate SiO, to alkali metal oxide a voltage ranging from 1 V to 100 V for 10 seconds to 100 MO (SiO /MO) in the aqueous alkali solution is 0.5 to 3.0 Seconds. and preferably, 1.0 to 2.0. If the ratio SiO2/MO is below US 6,830,874 B2 33 34 0.5, Sometimes it causes a problem that an aluminum In addition, if “p” is an integer of 2 to 100, R' may be Substrate is etched by the developer Since the alkali Strength the Same or different. Specific examples of Such a group becomes too strong. In contrast, if the ratio is beyond 3.0, the include a combination of ethyleneoxy group and propyle development performance would be deteriorated. neoxy group, a combination of ethyleneoxy group and The content of the alkali Silicate in the aqueous alkali isopropyloxy group, a combination of ethyleneoxy group solution is preferably 1% to 10% by weight, more preferably and butyleneoxy group, and a combination of ethyleneoxy 3% to 8% by weight and most preferably 4% to 7% by group and isobutylene group, in which each group may be weight. If the content is less than 1% by weight, the connected to each other in a random or block manner. In the development performance and processing performance may present invention, the nonionic Surfactant comprising a be deteriorated. If the content is more than 10% by weight, polyoxyalkylene ether group may be used alone or in a precipitation or crystalline material would be easily pro combination. An effective amount of the Surfactant to be duced in the developer and moreover, the developer easily used in a developer is in the range of 1% to 30% by weight gelates when it is neutralized, which may cause problem in and preferably from 2% to 20% by weight. If the amount of the treatment of the wastewater. 15 the Surfactant is too small, the development performance of Also, an organic alkali agent may be used as a Secondary the developer would be deteriorated. If the amount of the agent to aid a minute control of alkali concentration and an Surfactant is in excess, the printing durability would be improvement of solubility of the photosensitive layer. deteriorated. Examples of the organic alkaline agent include Examples of the nonionic Surfactant comprising a poly monomethylamine, dimethylamine, trimethylamine, oxyalkylene ether group represented by the above general monoethylamine, diethylamine, trie thylamine, formula (I) include polyoxyethylene alkyl etherS Such as monoisopropylamine, diisopropylamine, triisopropylamine, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, n-butylamine, monoethanolamine, diethanolamine, polyoxyethylene Stearyl ether and the like, polyoxyethylene trie than olamine, mo no isoprop a no la mine, aryl etherS Such as polyoxyethylene phenyl ether, polyoxy diisopropanolamine, ethyleneimine, ethylene diamine, 25 ethylene naphthyl ether and the like, polyoxyethylene alky laryl etherS Such as polyoxyethylene methylphenyl ether, pyridine, tetramethylammonium hydroxide and the like. The polyoxyethylene octylphenyl ether, polyoxyethylene non alkaline agent can be used alone or in a combination. The developer utilized in the method of the present ylphenyl ether and the like. invention comprises a nonionic Surfactant comprising a Further, the following other surfactants may be added to polyoxyalkylene ether group. The nonionic Surfactant in the the developer used in the present invention; nonionic Sur developer improves the Solubility of a non-irradiated portion factants (e.g., polyoxyethylene alkyl esterS Such as polyoxy of the photosensitive layer of the present invention and ethylene Stearate, Sorbitan alkyl esterS Such as Sorbitan decreases the permeability of the developer into an irradi monolaurate, Sorbitan monoStearate, Sorbitan distearate, Sor ated portion of the photosensitive layer. The following 35 bitan monooleate, Sorbitan Sesquioleate, and Sorbitan compound represented by the general formula (I) can be trioleate, and monoglyceride alkyl esterS Such as glycerol monostearate, and glycerol monooleate); anionic Surfactants Suitably utilized as the Surfactant comprising a polyoxyalky (e.g., Salts of alkylbenzenesulfonic acid Such as Sodium lene ether group. dodecylbenzeneSulfonate, Salts of alkylnaphthaleneSulfonic 40 acid Such as Sodium butylnaphthaleneSulfonate, Sodium In the formula (I), R" represents an optionally substituted p enty 1 naphthale n e Sulfonate, Sodium alkyl group having 3 to 15 carbon atoms, optionally Substi he Xylnaphthale n e Sulfonate, and Sodium tuted aromatic hydrocarbon group having 6 to 15 carbon octylnaphthaleneSulfonate, alkyl Sulfates Such as Sodium atoms, or optionally Substituted heteroaromatic ring having 45 laurylsulfate, Salts of alkylsulfonic acid Such as Sodium 4 to 15 carbon atoms, wherein the Substituent on these dodecylsulfonate, and Salts of SulfoSuccinic acid ester Such groups is an alkyl group having 1 to 20 carbon atoms, as Sodium dilaurylsulfoSuccinate); and amphoteric Surfac halogen atom Such as Br, Cl, I, etc., aromatic hydrocarbon tants (e.g., alkylbetaine Such as laurylbetaine and group having 6 to 15 carbon atoms, aralkyl group having 7 Stearylbetaine, and amino acids), with the anionic Surfac to 17 carbon atoms, alkoxyl group having 1 to 20 carbon 50 tants Such as alkylnaphthaleneSulfonic acid Salt being par atoms, alkoxy-carbonyl group having 2 to 20 carbon atoms, ticularly preferred. or acyl group having 2 to 15 carbon atoms, R' represents These Surfactants may be used alone or in a combination. an optionally Substituted alkylene group having 1 to 100 The amount of the Surfactant in the developer is suitably in carbon atoms, wherein the Substituent on the group is an 55 the range of 0.1% to 20% by weight, which the amount is alkyl group having 1 to 20 carbon atoms or aromatic calculated based on the weight of the effective component in hydrocarbon group having 6 to 15 carbon atoms, and “p' the Surfactant. represents an integer of 1 to 100. The preferred pH of the developer used in the present In the formula (I), Specific examples of “aromatic hydro invention is in the range of 11.0 to 12.7 and preferably of carbon group” include phenyl group, tolyl group, naphthyl 60 11.5 to 12.5. If the pH of the developer is lower than 11.0, group, anthryl group, biphenyl group, and phenanthryl it is not possible to form an image. In contrast, if the pH of group, Specific examples of "heteroaromatic ring include the developer is higher than 12.7, it causes problems. Such as furyl group, thionyl group, oxazolyl group, imidazolyl an over-development of the plate or a damage of an irradi group, pyranyl group, pyridinyl, acridinyl group, benzofura 65 ated portion during the development. nyl group, benzothionyl group, benzopyranyl group, ben The developer utilized in the present invention preferably ZOxazolyl group, and benzimidazolyl group. has conductivity in the range of 3 mS/cm to 30 mS/cm. If the US 6,830,874 B2 35 36 conductivity of the developer is lower than the range, exposure to light as described in J.P. KOKAI No. 2000 generally, it is difficult to elute (dissolve) the photosensitive 89478 to improve the printing durability of the plate. composition on an aluminum Substrate to thus result in a Thus obtained lithographic printing plate is Set on an contamination in the plate during printing process. If the offset press and then is used for printing. conductivity is higher than the range, an elution rate of the photoSensitive composition becomes So Slow to generate EXAMPLES remain of a non-irradiated portion of a film due to a high concentration of a Salt. In particular, the conductivity is Hereinafter, the present invention will be explained more preferably in the range of 5 mS/cm to 20 mS/cm. Specifically by Examples, but the present invention is not (Exposure to Light and Development) limited thereto. The PS plate of the present invention is imagewise exposed to a conventional active light Such as carbon arc Example 1 lamps, high pressure mercury lamps, Xenon lamps, metal A1S aluminum plate having a thickness of 0.30 mm was halide lamps, fluorescent lamps, tungsten lamps, halogen 15 Surface-grained with a No.8 nylon brush and a Suspension of lamps, helium-cadmium laser, argon ion laser, FDYAG 800 mesh pumice stone in water and then sufficiently laser, helium-neon laser and Semiconductor rays (350 nm to washed with water. After the plate was etched by immersing 600 nm). Then, the plate was developed with a developer to in an aqueous solution of 10% sodium hydroxide for 60 form an image on the Surface of the aluminum plate. After seconds at 70° C., the plate was washed with running water. being imagewise exposed to light and before being Then the plate was washed with 20% HNO to neutralize it developed, the plate may be heated at 50 C. to 150° C. for and washed with water. Then, an electrolytic graining of the 1 Second to 5 minutes in order to enhance the degree of plate was conducted in a 1% aqueous Solution of nitric acid polymerization of the photopolymerizable photoSensitive using a rectangle alternating continuous wave Voltage with layer. 25 an anode electric amount of 300 coulomb/dm under the Typically, an overcoat layer having an oxygen barrier condition of VA=12.7V. The roughness of the surface of the property is coated on a photosensitive layer of the PS plate plate determined with an experimental device: Surfcom of the present invention as described above. It is known that available from Tokyo Seimitu Co. Ltd., with a needle having Such an overcoat layer may be removed simultaneously with a tip diameter of 2 um, was 0.45 um (Ra). The plate was then the remove of the non-irradiated portion of the photosensi immersed in a 30% HSO for 2 minutes at 55 C. to desmut tive layer with a developer, or may be removed with water the Surface. Then, the plate was anodized in a 20% aqueous or hot water before removing the non-irradiated portion of solution of HSO at 33° C. by placing a cathode on the the photosensitive layer with a developer. Such water or hot grained surface using an electric current density of 5 A/dmf water may comprise preservatives as described in J.P. 35 for 50 Seconds to obtain a Substrate having an anodized layer KOKAI No. Hei 10-10754 and organic solvents as described of which thickness was 2.7 g/m. in J.P. KOKAI No. Hei 8-278636. The development of the PS plate of the present invention A solution of a polymer, U-1 (molecular weight Mn=10, with the developer described above may be conducted under 000) in water/methanol=5 g/95 g was coated on the treated the conventional condition, that is, by immersing the image 40 aluminum plate, and the plate was dried at 80 C. for 30 wise exposed plate in the developer at 0 to 60° C., preferably Seconds to form an intermediate layer. The thickness of the at 15 to 40° C. and by rubbing the plate with a brush. intermediate layer was 10 mg/m. A highly sensitive pho In addition, in the case that the development proceSS is topolymerizable composition P-1 described below was coated on the intermediate layer So that the dried weight conducted using an automatic development machine, the 45 development performance of the developer used therein thereof became 1.5 g/m, and then the plate was dried at (capability of the developer to sufficiently develop the plate) 100° C. for 1 minute to form a photosensitive layer. may be recovered by adding a replenisher or a fresh devel oper when the developer becomes exhausted after a large number of plates are treated. 50 The thus treated plate is then, generally treated with water, a rinse comprising a Surfactant, and/or a Solution for desen Sitizing the plate to grease comprising gum arabic, Starch derivatives and the like, as described in J.P. KOKAI Nos. 55 Sho 54-8002, Sho 55-115045, and Sho 59-58431. The PS CH COOH plate of the present invention may be Subjected to various combinations of the treatments. N'Eta Cl The thus treated plate may be further subjected to a heat treatment Such as a burning or to a treatment after an (Photopolymerizable Composition P-1)

Ethylenically unsaturated bond-containing compound (A1) 1.5 part by weight Linear organic polymer compound (polymer binder) (B1) 2.0 part by weight Sensitizer (C1) 0.15 part by weight US 6,830,874 B2 37 38

-continued Initiator of photopolymerization (D1) 0.2 part by weight e-Phthalocyanine (F1) dispersion 0.02 part by weight Fluorine atom-containing nonionic surfactant, Megafac F-177 (Dainippon Ink and Chemicals, 0.03 part by weight Inc.) Methyl ethyl ketone 9.0 part by weight Propylene glycol monomethyl ether acetate 7.5 part by weight Toluene 11.0 part by weight A1 O O

o- O O /-o

O O

B1 O O O H N N N 1N1\1\1 N H H /so H 20 O

O Mw = 60,000 O O O 20

COOH 80 n = 20

C1 CH

N. O. /C4Ho N N (C2H5)2N O S N V O C4Ho

D1 US 6,830,874 B2 39 40 A3% by weight solution of polyvinyl alcohol (the degree was 100° C., the developing temperature was 30°C., and the of saponification was 98% by mole and the degree of immersing time in the developer was about 15 Seconds. polymerization was 500) was coated on the photosensitive Developer 1 contains the components described below layer so that the dried weight of the polyvinyl alcohol and has a pH of 11.5 at 25 C. and conductivity of 5 mS/cm. became 2.5 g/m and the coating was dried at 120° C. for 3 5 minutes to obtain a PS plate. In order to determine the level of contamination of a lithographic printing plate under an aging condition, the PS (Developer 1) plate was stored for 5 days at 50° C. in 80% RH, which the Potassium hydroxide 0.15g Polyoxyethylene phenyl ether (n = 13) 5.0 g condition Simulates an aging condition. Chelest 400 (chelating agent) 0.1 g The PS plate before and after being stored under the Water 94.75 g Simulative aging condition was exposed to light with 100 uJ/cm’ of FDYAG laser (Plate Jet 4, available from CSI company) by scanning 1% to 99% of dot image (by 1%) and 15 Examples 2 to 7 solid image on the plate under a condition of 4000 dpi and 175 lines/inch. Then, the plate was subjected to a standard The same procedure as described in Example 1 was treatment in an automatic developing machine (LP-850P2, repeated except that the copolymer component for the available from Fuji Photo Film Co. Ltd.) comprising Devel intermediate layer in Table 2 was substituted for the copoly oper 1 and a finishing gum liquid FP-2W (available from mer component for the intermediate layer described in Fuji Photo Film Co. Ltd.). Preheating conditions for the Example 1 to obtain a lithographic printing plate before and plate were as follows; the temperature on the Surface of plate after being Stored under the aging condition.

TABLE 2

Composition for copolymer used in Intermediate layer (% by mole)

Example No. 2 3 4 5 6 7 Composition A. B C D E F

90 8O 85 8O 85 CHF al-O- COOH

1O 1O 1O 1O CHF ci-O- CHN'Eta Cl

CHN*Et Cl 1O CHF -O

15 CHF ci-O- CHN' Me Cl

1O CH-S CHFCH O) BF th 8O al-I-O- COOH

CH 1O 5 CH=C-COOCHCH-NH(CH) US 6,830,874 B2 41 42

TABLE 2-continued Composition for copolymer used in Intermediate layer (% by mole Example No. 2 3 4 5 Composition A. B C f

CH CH 1O CH=C-COONH-C-CHSOH CH Average molecular weight 18,000 7,000 23,000 12,000 5,000 45,000

Examples 8 to 10 composition P-1 described in Example 1 (that is, photopo lymerizable composition P-2 to P-6 was used instead of P-1) The same procedure as described in Example 1 was to obtain lithographic printing plates of Examples 11 to 15. repeated except that the coating amount of the intermediate layer in Example 1 was changed to 5 mg/m, 15 mg/m or B2 (P-2): allyl methacrylate/methacrylic acid (70/30% by 20 mg/m . mole) copolymer, molecular weight: 50,000. B3 (P-3): methyl methacrylate/isobutyl methacrylate/ Examples 11 to 15 methacrylic acid (60/20/20% by mole) copolymer, molecular weight 100,000. The same procedure as described in Example 1 was 25 B4 (P-4): methyl methacrylate/isopropylacrylamide/ repeated except that the linear organic polymer compound methacrylic acid (65/15/20% by mole) copolymer, B2 to B6 was substituted for B1 in photopolymerizable molecular weight 70,000.

Me Me

SO N N N1\-1 N-1N N H H 80 H H 20

-(-)-COOH ) (1-N-n} Molecular weight Mw = 40,000

O O O O CH N N N CH-N H H 80 H H 2O

Molecular weight Mw = 120,000

Example 16 The Same procedure as described in Example 15 was repeated except that the following compound (A2) was 65 Substituted for A1 (that is, ethylenically unsaturated bond containing compound P-7 was used) to obtain a lithographic printing plate of Example 16. US 6,830,874 B2 43 44 ness was 2.5 g/m. The plate was then washed with water to OH thus give Substrate A. The thus obtained substrate A was treated with an K-- aqueous Solution comprising 0.15% by weight of Sodium silicate at 22 C. for 10 seconds and was washed with water O to give substrate B. Substrate A was also treated with an aqueous Solution comprising 2.5% by weight of Sodium silicate at 30° C. for 10 seconds and was washed with water to give substrate C). Substrate A was also treated with an N aqueous Solution comprising 2.5% by weight of Sodium silicate at 50° C. for 5 seconds and was washed with water to give substrate D. Examples 17 to 20 15 The same procedure as described in Example 1 was An intermediate layer, a photoSensitive layer and OC repeated except that Developer 2, 3, 4 or 5 in Table 3 was layer were coated on the thus treated aluminum plates by the substituted for Developer 1 in Example 1. Same method as described in Example 1 to provide the corresponding PS plates. Then the PS plates were further TABLE 3 treated as described in Example 1 to provide lithographic pH conductivity printing plates that are before and after being kept in an aging condition. Developer 2 potassium hydroxide 0.15 g 11.7 6 mSfcm 25 Comparative Example 1 polyoxyethylene naphthyl ether (n = 10) 5.0 g Chelest 400 0.1 g water 94.75 g The same procedure as described in Example 1 was Developer 3 repeated except that the intermediate layer described in potassium hydroxide 0.15 g 11.9 6 mSfcm Example 1 was not formed, to obtain a lithographic printing polyoxyethylene naphthyl ether (n = 12) 5.0 g plate. triethanolamine 1.35 g Chelest 400 0.1 g water 93.4g Comparative Example 2 Developer 4 The same procedure as described in Example 1 was 1K-potassium silicate 2.5 g 12.2 20 mSfcm 35 potassium hydroxide 0.15g repeated except that Developer 6 comprising an amphoteric polyoxyethylene naphthyl ether (n = 10) 5.0 g Surfactant and an alkali metal Silicate Salt (SiO/KO), that Chelest 400 0.1 g is, a solution obtained by diluting LP-D developer available water 92.25 g developer 5 from Fuji Photo Film Co. Ltd. with water, was used in place 40 of Developer 1 described in Example 1, and that the PS plate 1K-potassium silicate 2.5 g 11.5 22 mSfcm potassium hydroxide 0.08 g prepared in the Comparative Example 1 was used in place of polyoxyethylene naphthyl ether (n = 12) 5.0 g the PS plate in Example 1. Developer 6 does not comprise Anon. LG 1.0 g any nonionic Surfactant comprising polyoxyalkylene ether Chelest 400 0.1 g 45 group. In addition, pH of Developer 6 was 12.8 and con water 91.32 g ductivity was 32 mS/cm. Printing durability and background contamination were Example 21 evaluated for the lithographic printing plates obtained by the JISA1050 aluminum plate having a thickness of 0.24 mm methods described in Examples 1 to 21 and Comparative was Surface-grained with a nylon brush and a Suspension of 50 Examples 1 to 2. 400 mesh pumice stone in water and then washed well with Printing operation with a lithographic printing plate was water. After the plate was etched by immersing in an conducted using R'-type printer available from Man acqueous solution of 10% sodium hydroxide for 60 seconds Roland company and GEOS G black (N) ink (available from at 70° C., the plate was washed with running water. Then the 55 plate was washed with 20% HNO to be neutralized and Dainippon Ink and Chemicals, Inc.) and the number of washed with water. Then, an electrolytic graining of the printings obtained before dots loss on 3% mesh was plate was conducted in a 1% aqueous Solution of nitric acid observed was determined to evaluate the printing durability using a rectangle alternating continuous wave Voltage with of the lithographic printing plate. an anode electric amount of 260 coulomb/dm under the 60 The background contamination was evaluated by Visibly condition of VA=12.7V. The roughness of the surface of the checking the presence of a contamination when the printing plate was 0.55 um (Ra). The plate was then immersed in a operation with a lithographic printing plate was conducted 30% HSO for 2 minutes at 55° C. to desmut the surface. using Daiya IF2 printer available from Mitsubishi Heavy Then, the plate was anodized in a 20% aqueous Solution of 65 Industries, Ltd., and GEOS G Red (S) available from HSO using an electric current density of 14 A/dm to Dainippon Ink and Chemicals, Inc. The results are shown in obtain a Substrate having an anodized layer of which thick Table 4. US 6,830,874 B2 45 46 to be used in the method of the present invention has a TABLE 4 relatively low pH and thus, the method of the present After being stored invention can be safely utilized and provides an effect to for 5 days at 50° C. reduce the influence of a waste of the developer on an Before being stored and 80% RH environment. Printing Printing What is claimed is: Background durability Background durability 1. A method for preparing a lithographic printing plate contami- (number of contami- (number of which comprises imagewise exposing to light a presensi nation copies) nation copies) tized plate useful for making a lithographic printing plate Example 1 None 50,000 None 60,000 having an intermediate layer and a photopolymerizable Example 2 None 80,000 None 70,000 photosensitive layer comprising an addition polymerizable Example 3 None 30,000 None 30,000 Example 4 None 40,000 None 50,000 or ethylenically unsaturated bond-containing compound, Example 5 None 50,000 None 50,000 photopolymerization initiator, and polymer binder on an Example 6 None 50,000 None 40,000 15 Example 7 None 70,000 None 60,000 aluminum Substrate in this order and developing the image Example 8 None 60,000 None 60,000 wise exposed plate with a developer, wherein Said interme Example 9 None 50,000 None 50,000 diate layer comprises a polymer compound comprising at Example 10 None 30,000 None 50,000 Example 11 None 70,000 None 60,000 least a structure unit having an acid group and a structure Example 12 None 40,000 None 40,000 unit having an onium group and Said developer comprises an Example 13 None 80,000 None 80,000 Example 14 None 60,000 None 60,000 inorganic alkali Salt and a nonionic Surfactant having the Example 15 None 40,000 None 50,000 structure represented by the following formula (I) Example 16 None 30,000 None 50,000 Example 17 None 60,000 None 60,000 Example 18 None 70,000 None 60,000 Example 19 None 80,000 None 80,000 25 Example 20 None 60,000 None 50,000 wherein, R" represents an optionally substituted naphthyl Example 21 None 50,000 None 40,000 group, R' represents an optionally Substituted alkylene Comp. Ex. 1 Slightly 30,000 Severely 40,000 group having 1 to 100 carbon atoms, and “p’ represents contaminated contaminated an integer of 1 to 100, and Said developer has a pH Comp. Ex. 2 Slightly 40,000 Slightly 40,000 contaminated contaminated ranging from 11.0 to 12.7. 2. The method of claim 1, wherein the acid group in the Structure unit of the polymer compound is selected from the AS Seen from Table 4, every printing plate of the group consisting of -COOH, -SOH, -OSOH, Examples of the present invention gave good results. In -POH, - O POH, -CON HS O-, and contrast, the printing plate of Comparative Example 1 35 -SONHSO-. showed background contamination when the plate was 3. The method of claim 1, wherein the onium group in the Stored at high temperature under high humidity. In addition, Structure unit of the polymer compound comprises an atom the printing durability of the plate of Comparative Example Selected from atoms of group 5 and group 6 in the periodic 1 was low both before and after Storage. Also, the printing table. plate of Comparative Example 2 which was developed with 40 4. The method of claim 1, wherein the structure unit a developer comprising nonionic Surfactant having polyoxy having an acid group is derived from the compound repre alkylene ether group showed a background contamination sented by the following both before and after the Storage. In addition, the printing plate of Comparative Example 2 showed low printing dura 45 (1) bility both before and after storage. R1 As seen from the above, the method of the present cu invention provides a lithographic printing plate which shows no background contamination even after Storage under a (A) (B) -(D)-X), 50 (2) Simulative aging condition and high printing durability. R1 Thus, the method for preparing a lithographic printing plate which comprises imagewise exposing to light a pre CHFC Sensitized plate useful for making a lithographic printing (A) (B), (G)-(D)-X plate having an intermediate layer and a photoSensitive layer 55 on an aluminum Substrate in this order and developing the (E) -X imagewise exposed plate with a developer, wherein Said intermediate layer comprises a polymer compound having a general formula (1) or (2); component with acid group and a component with an onium wherein A is a bivalent connecting group; B is a bivalent, group and Said developer comprises an inorganic alkali Salt 60 trivalent or tetravalent aromatic or Substituted aromatic group; D and E each independently represents a bivalent and a nonionic Surfactant having polyoxyalkylene ether connecting group; G is a trivalent connecting group; X and group and pH of the developer ranges from 11.0 to 12.7 X" each independently represents an acid group having pKa gives a lithographic printing plate which shows good con of 7 or less or an alkali metal Salt or ammonium Salt thereof; trast between an image area and non-image area, no back 65 R" is a hydrogen atom, alkyl group or halogen atom; “a”, ground contamination during printing, good Stability with “b”, “d” and “e” each independently represents 0 or 1; and time and good printing durability. In addition, the developer “t' is 1 to 3. US 6,830,874 B2 47 48 5. The method of claim 4, wherein A is -COO-or wherein J is a bivalent connecting group; K is a bivalent, -CONH-; B is a phenylene group or substituted phe trivalent or tetravalent aromatic or a Substituted aromatic nylene group wherein the Substituent is a hydroxy group, group, M independently represents a bivalent connecting halogen atom or alkyl group; D and E each independently group; Y is an atom of group 5 in the periodic table, Y is an atom of group 6 in the periodic table; Zis a counter represents an alkylene group or a bivalent connecting group anion; R is a hydrogen atom, alkyl group or halogen atom; represented by the molecular formula of CHO, CHS or R. R", RandR each independently represents a hydrogen CHN; G is a trivalent connecting group represented by atom or an optionally Substituted alkyl group, aromatic the molecular formula of CH2-1, CH2O, CH2S or group, or aralkyl group; R is an alkylidene group or CHN, wherein “n” is 1 to 12; X and X" each indepen substituted alkylidene group; R and R', or R and R may dently represents a carboxylic acid, Sulfonic acid, phospho be linked together to form a ring; “j”, “k” and “m” each nic acid, Sulfuric acid mono ester or phosphoric acid mono independently represents 0 or 1; and “u' is 1 to 3. ester; R' is a hydrogen atom or alkyl group; “a”, “b”, “d” and 8. The method of claim 7, wherein J is -COO- or “e” each independently represents 0 or 1, provided that “a” -CONH-; K is a phenylene group or a substituted phe and “b” are not simultaneously 0. 15 nylene group wherein the Substituent is a hydroxy group, 6. The method of claim 5, wherein B is a phenylene group halogen atom or alkyl group; M is an alkylene group or a or Substituted phenylene group wherein the Substituent is a bivalent connecting group having the molecular formula of hydrogen group or C1 to C3 alkyl group; D and E each CHO, CHS or CHN, wherein “n” is 1 to 12; Y independently represents C1 or C2 alkylene group or C1 or is a nitrogen atom or phosphorus atom; Y is a Sulfur atom; C2 alkylene group which is connected via an oxygen atom; Z is a halogen ion, PF, BF, or RSOs; R is a hydrogen R" is a hydrogen atom or methyl group; X is a carboxylic atom or alkyl group; R. R', R and R7 each independently acid group; “a” is 0; and “b' is 1. represents a hydrogen atom or optionally Substituted C1 to 7. The method of claim 1, wherein the structure unit C10 alkyl group, aromatic group, or aralkyl group; R is a having an onium group is derived from the compound 25 C1 to C10 alkylidene group or Substituted alkylidene group; represented by the following general formula (3), (4) or (5); R and R", or R and R may be linked together to form a ring; “”, “k” and “m” each independently represents 0 or 1 (3) provided that “j” and “k” are not simultaneously 0; and R R2 is an optionally Substituted C1 to C10 alkyl group, aromatic group, or aralkyl group. cu- R3 9. The method of claim 8, wherein K is a phenylene group (j)-(K) (M) -Yi'-R' uZ or Substituted phenylene group wherein the Substituent is a R hydroxy group or C1 to C3 alkyl group; M is C1 or C2 (4) 35 alkylene group or C1 or C2 alkylene group connected via an R2 oxygen group; Z is a chloride ion or RSO; R is a cu- R6 hydrogen atom or methyl group; “j” is 0; “k” is 1; and R is M C1 to C3 alkyl group. (J)-(K) (M)n Yi' uZ 40 10. The method of claim 1, the pH of the developer ranges Y7 from 11.5 to 12.5. (5) 11. The method of claim 1, wherein the amount of the R2 nonionic Surfactant in the developer is in the range of 1% to 30% by weight. cu- R3 45 M 12. The method of claim 11, wherein the amount of (J)-(K) (M)n Y.,' uZ nonionic Surfactant in the developer is in the range of 2% to y4 20% by weight.