JP2009237174A - Photosensitive composition, planographic printing plate precursor, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition which is satisfactorily developable with a developer solution of pH 2.0 to 6.5, is excellent in abrasion resistance and soiling prevention, and also is imparted with the reproducibility of sensitivity in image formation, to provide an image forming method, and to provide a planographic printing plate precursor capable of producing a planographic printing plate. <P>SOLUTION: The photosensitive composition has a photosensitive layer on a support, the photosensitive layer containing (A) a binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and/or a side chain, (B) a compound having an ethylenically unsaturated bond, and (C) a polymerization initiator. The image forming method comprises imagewisely exposing the photosensitive composition to a laser beam and removing the photosensitive layer in an unexposed part. The planographic printing plate precursor contains the photosensitive composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive composition, a lithographic printing plate precursor using the composition, and an image forming method.

In general, a lithographic printing plate has a surface composed of an oleophilic image portion and a hydrophilic non-image portion. In lithographic printing, dampening water and oil-based ink are alternately applied to the plate surface, and the hydrophilic non-image area is dampened with a dampening water receiving area (ink non-receiving area) by utilizing the property that water and oil repel each other. ), After the ink is received only in the oleophilic image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive layer (image recording layer) is provided on a hydrophilic support has been widely used. Normally, after exposing a lithographic printing plate precursor through an original image such as a lithographic film, the photosensitive layer to be an image portion is left, and other unnecessary photosensitive layers are dissolved with an alkaline developer or an organic solvent. The lithographic printing plate is obtained by carrying out plate making by a method of exposing the surface of the hydrophilic support to form a non-image portion by removing it.

  In the conventional plate-making process of a lithographic printing plate precursor, a step of dissolving and removing unnecessary photosensitive layers with a developer or the like is necessary after exposure, but simplifies such additional wet processing. Is listed as one of the issues. As one of simplification, it is desired that development can be performed with an aqueous solution close to neutrality or simple water.

  On the other hand, in recent years, digitization technology that electronically processes, stores, and outputs image information using a computer has become widespread, and various new image output methods corresponding to such digitization technology have been put into practical use. It has come to be. Along with this, digitized image information is carried by high-convergence radiation such as laser light, and the lithographic printing plate precursor is scanned and exposed with that light, directly without using a lithographic film. Computer-to-plate technology for manufacturing is attracting attention. Accordingly, obtaining a lithographic printing plate precursor adapted to such a technique is one of the important technical issues.

  From the background as described above, it is now more strongly desired than ever to adapt both the simplification of the plate making operation and the digitization.

  On the other hand, for example, in Patent Document 1, in an image forming layer of a lithographic printing plate precursor having an image forming layer containing a hydrophobizing precursor, a hydrophilic resin, and a photothermal conversion agent on a hydrophilic support. In addition to the on-press development, it can also be used for printing after exposure by liquid development using water or a suitable aqueous solution as a developer by further containing a compound having an ethylene oxide chain. Has been.

  Patent Document 2 contains (i) a hydrophilic support, and (ii) a radical polymerizable ethylenically unsaturated monomer, a radical polymerization initiator and an infrared absorbing dye, and is cured by infrared laser exposure. Moreover, a lithographic printing plate precursor comprising an oleophilic heat-sensitive layer containing 60% by mass or more of water and developable with an aqueous developer having a pH of 2.0 to 10.0 is prepared and exposed imagewise with an infrared laser. A processing method for a lithographic printing plate precursor comprising removing an uncured region of the heat-sensitive layer with an aqueous developer is described.

On the other hand, as a photosensitive resin composition having an ammonium salt, a photosensitive resin composition introduced by opening an epoxy group with an amino group is known (see Patent Documents 3 to 5). It is not shown that both developability and printing durability can be achieved when used in the above. Moreover, when the binder polymer which has a hydroxyl group is used, the stain | pollution | contamination property by adsorption | suction to a board | substrate will deteriorate, and there existed a problem in practical use. Furthermore, there is a practical problem that the exposure amount (image formation sensitivity) necessary for performing a constant image formation is not stable (reproducibility is poor).
JP 2002-365789 A US Patent Application Publication No. 2004/0013968 JP-A-6-59448 JP-A-6-202329 JP-A-8-109232

  In order to maintain the developability of the aqueous developer having a pH of 2.0 to 10.0 as described above, and the aqueous developer of pH 2.0 to 6.5 having a lower pH, the photosensitive layer is hydrophilic or has high water penetration. The photosensitive layer cured by exposure has insufficient water resistance and film strength. In addition, when the binder polymer used in the conventional lithographic printing plate precursor is applied, there is a problem that the stain resistance cannot be satisfied by aqueous development at pH 2.0 to 6.5. In order to solve these problems, the photosensitive layer cured by laser exposure can impart excellent printing durability to the image area, and the photosensitive layer in the unexposed area is excellent by an aqueous developer having a pH of 2.0 to 6.5. Furthermore, it is necessary to provide a photosensitive composition, a lithographic printing plate precursor, and an image forming method that have a good reproducibility of image forming sensitivity.

  The present inventor has found that the above problem can be solved by incorporating a binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain into the photosensitive layer. That is, the present invention is as follows.

1. A photosensitive composition having a photosensitive layer containing the following (A) to (C) on a support.
(A) Binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain (B) Compound having ethylenically unsaturated bond (C) Polymerization initiator (A) In a binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain, groups having a positively charged nitrogen atom are represented by the following general formulas (1) to (1): 4. The photosensitive composition as described in 1 above, which has a group represented by any one of 4).

In the formula, R _{1 to} R ₇ each represent a monovalent substituent, and X ⁻ represents an anion. Any _{two of} R ₁ and R ₂ and R _{4 to} R ₆ may be bonded to each other to form a ring. In the general formulas (2) and (4), -N ⁺ = C- constitutes a cyclic structure.
3. (A) The 1 or 2 above, wherein the binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain is a (meth) acrylic resin or a urethane resin. The photosensitive composition as described in any one of.
4). (A) The photosensitive composition as described in 1 or 2 above, wherein the binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain is a urethane resin. object.
5. In the general formulas (1) to (4), at least one of R ₁ and R ₂ , R ₃ , at least one of R _{4 to} R ₆ , and R ₇ have a group having a hydrogen atom. The photosensitive composition in any one of said 1-4.
6). The binder polymer having at least one positively charged nitrogen atom and at least one amino group is made by neutralizing a part of the amino group of the polymer having an amino group with an acid, The photosensitive composition in any one of said 1-5.
7). The photosensitive composition as described in any one of 1 to 6 above, wherein the photosensitive layer further contains (D) a sensitizing dye.
8). The photosensitive composition according to any one of 1 to 7 above is image-exposed with a laser, and then the unexposed photosensitive layer is removed in the presence of a developer having a pH of 2 to 6.5. Image forming method.
9. A lithographic printing plate precursor comprising the photosensitive composition as described in any one of 1 to 7 above.

  Although the mechanism of action of the present invention is not clear, the following is presumed. Conventionally, developability to a developer having a pH of 2.0 to 10.0 has been imparted by increasing the hydrophilicity of the binder polymer, but this also means that the developer and dampening water have penetrated significantly into the exposed area. Inevitably, this was a major factor that deteriorated printing durability. The binder polymer having a positively charged nitrogen atom in the main chain and / or side chain of the present invention, preferably selected from the structures represented by the following general formulas (1) to (4) in the main chain and / or side chain. By introducing a specific salt structure such as a binder polymer having at least one group, the interaction between the binder polymer and the surfactant is improved, and developability to a developer having a pH of 2.0 to 6.5 is imparted. Think of it as possible. In addition, the specific salt structure selected from the structures represented by the general formulas (1) to (4) is currently considered to be able to improve the adhesion with the substrate or the undercoat layer. It is presumed that the permeability of the developer and dampening water at pH 2.0 to 6.5 can sometimes be lowered, and the printing durability is improved. These actions are considered to have achieved the conflicting performances of developability and printing durability with a developer having a pH of 2.0 to 6.5. On the other hand, it was surprising that the reproducibility of image formation sensitivity was imparted by incorporating not only positively charged nitrogen atoms but also amino groups into the binder structure. Although details are unknown, it is considered that the stabilization by the function of inhibiting the polymerization of amino groups can be imparted, and the reproducibility of image formation sensitivity can be imparted.

  According to the present invention, a photosensitive film which can be satisfactorily developed with a developer having a pH of 2.0 to 6.5, has excellent printing durability and stain resistance, and is provided with reproducibility of image formation sensitivity. A lithographic printing plate precursor capable of producing a lithographic composition, an image forming method, and a lithographic printing plate can be provided.

  The photosensitive layer, photosensitive composition (lithographic printing plate precursor as an example), and image forming method according to the present invention will be described in detail below.

(Photosensitive layer)
The photosensitive layer of the lithographic printing plate precursor according to the invention comprises a binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain, preferably a positively charged nitrogen atom. A binder polymer having at least one group selected from the structures represented by the following general formulas (1) to (4), a compound having an ethylenically unsaturated bond, and a radical polymerization initiator: It is characterized by containing.
Below, the component of the polymeric composition which comprises a photosensitive layer is demonstrated in detail.

(Binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain)
The binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain of the present invention (hereinafter referred to as a specific binder polymer as appropriate) refers to the main chain of the polymer chain. In addition, any compound may be used as long as the polymer has at least one ammonium base and one amino group in the side chain portion. Preferably, it is a binder polymer having at least one group selected from structures represented by the following general formulas (1) to (4) as a group having a positively charged nitrogen atom in the main chain and / or side chain. is there. The binder polymer having at least one group selected from the structures represented by the following general formulas (1) to (4) in the main chain and / or side chain is represented by the general formulas (1) to (4). Any compound may be used as long as the polymer compound has at least one group as a repeating unit.

Here, in general formulas (1) to (4), R _{1 to} R ₇ each independently represents a monovalent substituent. Here, the monovalent substituent is a substituent consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen and silicon. Further, any _{two of} R _1, R ₂ and R _{4 to} R ₆ may be bonded to each other to form a ring. The substituent consisting of at least one atom selected from hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, halogen, and silicon is -H, -F, -Cl, -Br, -I,> C <, = C <, ≡C-, -O-, O =, -N <, -N =, ≡N, -S-, S =,> S <, ≡S≡, -P <, ≡P <,> Si <, ═Si <, ≡Si— and monovalent substituents formed by combining these. Monovalent substituents include hydrogen atoms, alkyl groups [eg, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl. Group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2 -Methylhexyl, cyclohexyl, cyclopentyl, 2-norbornyl, chloromethyl, bromomethyl, 2-chloroethyl, trifluoromethyl, methoxymethyl, methoxyethoxyethyl, allyloxymethyl, phenoxymethyl Methylthiomethyl group, tolylthiomethyl group, Tylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl Group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-di Propylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group , Phosphonatohexyl group, Diethylphosphonobutyl group, Diphenylphosphonopropyl group, Methylphosphonobutyl group, Methylphosphonobutyl group, Tolylphosphonohexyl group, Tolylphosphonatohexyl group, Phosphonoxypropyl group, Phosphonato Oxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, etc.], aryl group [eg, phenyl group, biphenyl group, naphthyl group, tolyl group , Xylyl group, mesityl group, cumenyl group, chlorophenyl group, Lomophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylamino Phenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, nitrophenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group , Phosphonophenyl group, phosphonatophenyl group, etc.), heteroaryl group (for example, thiophene, thiathrene, furan, pyran, isobenzofuran, chromene, Nten, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indoir, indazole, purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, sinoline, pteridine, carbazole , A carboline, a phenanthrine, an acridine, a perimidine, a phenanthroline, a phthalazine, a phenazazine, a phenoxazine, a furan, a group derived from a hetero ring such as phenoxazine, an alkenyl group (for example, a vinyl group, a 1-propenyl group, a 1- Butenyl, cinnamyl, allyl, 1-propenylmethyl, 1-butenyl, 2-methylallyl, 2-methylpropenylmethyl, 2-chloro-1-ethenyl, etc.], alkynyl For example, an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a trimethylsilylethynyl group, etc.), a halogen atom [—F, —Br, —Cl, —I ], Hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N , N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkyls Hoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N ′ -Arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N′-alkyl-N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N -Alkylurei Group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonyl Amino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkyl Carbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group , a sulfo group (-SO ₃ H And its conjugate base group (hereinafter referred to as sulfonate group), alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl Group, N, arylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonate group), dialkylphosphono group (-PO ₃ (alkyl) ₂ ), diaryl phosphono group (-PO ₃ (aryl) ₂ ), alkyl aryl phosphono group (—PO ₃ (alkyl) (aryl)), monoalkyl phosphono group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkyl phosphonate group), monoaryl phosphono group (—PO 3 ₃ H (aryl)) and its conjugate base group (hereinafter referred to as arylphosphonate group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonateoxy group), dialkyl Phosphonooxy group (—OPO ₃ (alkyl) ₂ ), diaryl phosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylaryl phosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkyl phosphine A phonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as an alkylphosphonatooxy group), a monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group ( After that, And a cyano group, a nitro group, and the like. A hydrogen atom, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, a halogen atom, an alkoxy group, and an acyl group are preferable, and printing durability , A hydrogen atom, an alkyl group, and an aryl group are more preferable from the viewpoints of developability with a developer having a pH of 2.0 to 6.5 and stain resistance, and a hydrogen atom or the total number of carbon atoms of R _{1 to} R ₂ , R ₃ More preferred are alkyl groups and aryl groups in which the total number of carbon atoms in R ₄ , R _{4 to} R ₆ , and R ₇ have 1 to 12 carbon atoms, respectively. More preferably, at least one of R ₁ and R ₂ , R _3, at least one of R _{4 to} R ₆ , and R ₇ are hydrogen atoms.

In the general formulas (2) and (4), -N ⁺ = C- constitutes a cyclic structure.
In general formulas (2) and (4), the cyclic structure containing —N ⁺ ═C— is preferably a 5- to 7-membered ring, for example, a 5-membered ring such as a pyrrolium ring, an imidazolium ring, or a pyrazolium ring. Examples thereof include 6-membered ring structures such as a structure, a pyridinium ring, a quinolinium ring, and an acridinium ring.
Among the general formulas (1) to (4), the most preferable structure is the general formula (3). In particular, it is preferable that one of R _{4 to} R _{6 in} the general formula (3) is a hydrogen atom, and the remaining two are an alkyl group or an aryl group. Further, an alkyl group or an aryl group having a total of the remaining two carbon atoms of 1 to 12 is more preferable.

In the general formulas (1) to (4), X ⁻ is an anion. Specific examples thereof include halogen anions, halogen oxoacid anions (ClO ₄ ⁻ , IO ₃ ⁻ , BrO ₃ ⁻ , etc.), halogeno complexes. ion _{^{(BF 4 -, PF 6 -}} , AlCl 4 -, etc.), a sulfate anion, nitrate anion, phosphate anion, a borate anion, a carboxylate anion, sulfonate anion, a phosphonate anion and a metal complex anion ([Fe (CN ) ₆ ] ^- , etc.). Among these, a halogen anion, a halogeno complex ion, a borate anion, a carboxylate anion, and a sulfonate anion are preferable, and a halogeno complex ion, a borate anion, and a sulfonate anion are more preferable from the viewpoint of printing durability and stain resistance.

Any method may be used for introducing the ammonium salt into the polymer. For example, a method of copolymerizing a quaternary ammonium group-containing acrylate monomer exemplified in [Chemical Formula 3] with another vinyl compound, The tertiary amine-containing acrylate monomer exemplified in [Chemical Formula 4] is copolymerized with another vinyl compound, and then neutralized with an acid and quaternary ammonium chloride or quaternary with an alkylating agent. A method of ammonium chloride, a method of copolymerizing a quaternary ammonium group-containing diol compound exemplified in [Chemical Formula 5] with an isocyanate, a carboxylic acid and a carboxylic acid derivative, and a tertiary amine-containing diol exemplified in [Chemical Formula 6] Is copolymerized with isocyanate, carboxylic acid, carboxylic acid derivative, and then neutralized with acid to produce tertiary ammonium chloride or alkyl Quaternary ammonium how to chloride by agents.
Examples of introduction sites include introduction to random side chains and main chains, introduction to block side chains and main chains, end capping and introduction to polymer ends, as described above, synthesis of macromonomers, grafting From the viewpoint of developability, introduction into a main chain or side chain in a random or block manner or introduction after grafting is preferable.

Specific examples of acids used to neutralize with acids to form tertiary ammonium salts include hydrohalic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, carbonic acid Mineral acids such as tetrafluoroboric acid and pentafluorophosphoric acid, halogen oxo acids such as perchloric acid, benzoic acid, 2,5-dichlorobenzoic acid, 3,5-dichlorobenzoic acid, pentafluoro Benzoic acid, 4-methoxybenzoic acid, 3,4-dimethoxybenzoic acid, 4-bromobenzoic acid, 4-dimethylaminobenzoic acid, 4-diethylaminobenzoic acid, 1-naphthoic acid, 4-nitrobenzoic acid, 4-phenyl Carboxylic acids such as benzoic acid, toluic acid, benzoylformic acid, acetic acid, tert-butylacetic acid, lauric acid, behenic acid, stearyl acid, nonanoic acid, 3-cyclohexanebutanoic acid, etc. 4-amino-1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 2,4,5-trichlorobenzenesulfonic acid, dansylic acid, p-xylene-2-sulfonic acid, 2,4-dinitrobenzene acid methanesulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 4-nitrobenzenesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, 4-ethylbenzenesulfonic acid, dodecylbenzenesulfonic acid, ethanesulfonic acid, propanesulfonic acid, amino Ethanesulfonic acid, 2-cyclohexylaminoethanesulfonic acid, (+)-10-camphorsulfonic acid, sulfonic acid such as 3-hydroxypropanesulfonic acid, alkyl sulfuric acid such as 2-aminoethyl hydrogensulfate, ethyl phosphate, butyl phosphate Dibutylphos Eto, and the like phosphoric acids such as phenyl phosphonic acid. Among these, nonvolatile carboxylic acid, sulfonic acid, and phosphonic acid are preferable from the viewpoint of image formation stability. From the viewpoint of printing durability, the log P value of the neutralized acid is preferably 6 or less, preferably 4 or less, and more preferably 2 or less (here, the log P value is the distribution coefficient P ( This is a common logarithm of (Partition Coefficient). It is a physical property value that expresses how an organic compound is distributed in the equilibrium of a two-phase system of oil (generally 1-octanol) and water as a quantitative value. Log P = log (Coil / Cwater) Coil = Molar concentration in oil phase Cwater = Molar concentration in water phase) From the viewpoint of sensitivity, the pKa of the neutralizing acid is preferably -5 to 8, more preferably -3 to 6, and further preferably -1 to 4. Specific examples of the neutralizing acid satisfying these include benzoic acid, 2,5-dichlorobenzoic acid, 3,5-dichlorobenzoic acid, pentafluorobenzoic acid, benzoylformic acid, lauric acid carboxylic acid, 2-naphthalenesulfonic acid, 2,4,5-trichlorobenzenesulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, 4-ethylbenzenesulfonic acid, dodecylbenzenesulfonic acid, ethanesulfonic acid, More preferred are propanesulfonic acid and (+)-10-camphorsulfonic acid sulfonic acid.

  Furthermore, allyloxypropionic acid, acrylamide hexanoic acid, 3-butenoic acid, acrylic acid, methacrylic acid, 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl phthalic acid, 2 -Carboxylic acids having radically polymerizable unsaturated double bonds such as methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid, 4-vinylbenzoic acid, etc. A sulfonic acid having a radically polymerizable unsaturated double bond such as 2-acrylamido-2-methylpropanesulfonic acid or 4-vinylbenzenesulfonic acid is more preferable from the viewpoints of sensitivity and printing durability.

Moreover, as an alkylating agent used in order to make a quaternary ammonium salt with an alkylating agent, a chlorinated product (R-Cl), a brominated product (R-Br), an iodinated product (R-1), a sulfate ester ( R′O—SO ₂ —OR ′), sulfonic acid ester (R′—SO ₂ —OR) and the like. Specific examples of these alkylating agents include dialkyl sulfuric acid, alkyl paratoluenesulfonate, alkyl-trifluoromethanesulfonate, alkyl trifluoromethanesulfonate (triflate), alkyl methanesulfonate (mesylate) and the like. Specific examples of such alkylating agents include chloromethane, chloroacetic acid, chloropropionic acid, iodomethane, 1-iodoethane, 1-iodooctane, bromomethane, 1-bromoethane, 1-bromohexane, 3-bromopropionic acid. n-methyl, dimethyl sulfate, diethyl sulfate, dibutyl sulfate, diamyl sulfate, dihexyl sulfate, dioctyl sulfate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, n-hexyl p-toluenesulfonate, p-toluenesulfonic acid n-octyl, methyl methanesulfonate, ethyl methanesulfonate, n-hexyl methanesulfonate, and the like. Iodomethane, 1-iodoethane, dimethyl sulfate, diethyl sulfate, methyl p-toluenesulfonate, p-toluenesulfonic acid Ethyl, methane Methyl sulfonic acid are preferable from the viewpoint of hydrophobicity and counter anion of quaternary ammonium salt.

On the other hand, the amino group in the binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain may be any primary, secondary or tertiary amino group. In view of the storage stability of the product and the reproducibility of image formation sensitivity, a tertiary amino group is preferable. The introduction method may be any method, but specifically, a method of copolymerizing the monomer having an unsaturated double bond described in [Chemical Formula 4] or a method of copolymerizing the diol compound of [Chemical Formula 6] Etc. can be introduced.
As in the present invention, a method for producing a binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain is achieved by using the method as described above. However, a particularly preferable method is a method in which a binder polymer having an amino group in the side chain is neutralized with an acid to convert some amino groups into an ammonium base. As the amino group, a tertiary amino group is preferably used, and it is preferable to neutralize with an acid to make a part thereof an ammonium base.

  As the skeleton structure of such a specific binder polymer, any structure having at least one group selected from the structures represented by the general formulas (1) to (4) in the main chain and / or the side chain. Although it is preferably a polymer compound, as the chain polymerization resin, (meth) acrylic resin, styrene resin, epoxy resin, polyvinyl acetal resin, sequential polymerization resin, polyurethane resin, polyamide resin, polyester resin, Polymer compounds selected from polyurea resins are preferred. From the viewpoint of synthesis suitability, film properties, printing durability, and developability, (meth) acrylic resins and styrene resins are chain polymerization resins, and sequential polymerization resins are A polyurethane resin is more preferable.

  The specific binder polymer of the present invention is represented by a compound having at least one group selected from the structures represented by the general formulas (1) to (4) and the general formulas (1) to (4). It may be a copolymer with another copolymerizable compound having no structure. Of the copolymerizable compounds, examples of the chain polymerization compound include the compounds listed in the following (m1) to (m11).

(M1) For example, acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(M2) Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, and glycidyl acrylate.
(M3) Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, and glycidyl methacrylate.
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.
(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene.
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(M10) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like.
(M11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.

  Examples of the sequential polymerization compound copolymerizable with a compound having at least one group selected from the structures represented by the general formulas (1) to (4) include the following bifunctional compounds: (Diamine compounds, dicarboxylic acids or derivatives thereof, diisocyanate compounds, diol compounds).

Examples of the diamine compound include those shown below.
Ethylenediamine, 1,3-diaminopropane, 1,2-diaminopropane, 1,4-diaminobutane, 1,2-diamino-2-methylpropane, 1,5-diaminopentane, 2,2-dimethyl-1,3 -Propanediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,10-diaminodecene, 4,4'-methylenebis (cyclohexylamine), 1,2-diaminocyclohexane, 1,4 -Aliphatic diamines such as diaminocyclohexane, isophorone diamine, 2,2 '-(ethylenedioxy) -bis (ethyleneamine), 4,7,10-trioxa-1,13-tridecanediamine, 1,2- Phenylenediamine, 2,3-diaminotoluene, 3,4-diaminotoluene, 4-chloro-1,2 -Phenylenediamine, 4,5-dimethyl-1,2-phenylenediamine, 4,5-dichloro-1,2-phenylenediamine, 1,3-phenylenediamine, 2,6-diaminotoluene, 2,4-diaminotoluene 2,4,6-trimethyl-1,3-phenylenediamine, 1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, 2,5-dichloro-1,4-phenylenediamine, 4, , 4 ′-(hexafluoroisopropylidene) diamine, 2,3-diaminonaphthalene, 1,5-diaminonaphthalene, p-xylenediamine, 4-aminobenzylamine, 2- (4-aminophenyl) ethyleneamine, bis ( Aromatic diamines such as 4-aminophenylmethane) and bis (4-aminophenyl) ether, etc. Of these, aromatic diamine compounds and aliphatic diamine compounds having 2 to 10 carbon atoms are particularly preferable.

  Dicarboxylic acids or their derivatives include succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrabromophthalic acid, tetrachlorophthalic acid, 1, Examples include 4-cyclohexanedicarboxylic acid, carboxynorbornanoic acid, 5-sodium sulfoisophthalic acid, 4-hydroxybenzylidene malonic acid, 3-hydroxyphthalic acid and other dicarboxylic acids or derivatives thereof. Among them, dicarboxylic acids having aromaticity or A derivative thereof, an aliphatic dicarboxylic acid having 2 to 10 carbon atoms or a derivative thereof is particularly preferred.

  The specific polyamide resin according to the present invention can be easily produced by, for example, a method described in “New Polymer Experiments 3 Synthesis and Reaction of Polymer (2)” published by Kyoritsu Shuppan Co., Ltd.

As a diisocyanate compound, it represents with General formula (5). The diol compound is represented by the general formula (6). In the general formulas (5) and (6), X ⁰ and Y ⁰ each independently represent a divalent organic residue.

OCN-X ⁰ -NCO (5)
HO-Y ⁰ -OH (6)

Specific examples of the diisocyanate compound represented by the general formula (5) include those shown below. That is, 2,4-tolylene diisocyanate, 2,4-tolylene diisocyanate dimer, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate Aromatic diisocyanate compounds such as 1,5-naphthylene diisocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate; hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate, etc. Aliphatic diisocyanate compounds; isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate A cycloaliphatic diisocyanate compound such as 1,3- (isocyanatomethyl) cyclohexane; a reaction product of a diol and a diisocyanate such as an adduct of 1 mol of 1,3-butylene glycol and 2 mol of tolylene diisocyanate A diisocyanate compound; and the like.

  Examples of the diol compound represented by the general formula (6) include a polyether diol compound, a polyester diol compound, and a polycarbonate diol compound.

  Examples of the polyether diol compound include compounds represented by the following formulas (7), (8), (9), (10) and (11), and random copolymerization of ethylene oxide and propylene oxide having a hydroxyl group at the terminal. Coalescence is mentioned.

In formulas (7) to (11), R ¹⁴ represents a hydrogen atom or a methyl group, and X ¹ represents the following group. A, b, c, d, e, f and g each represent an integer of 2 or more, preferably an integer of 2 to 100.

Specific examples of the polyether diol compound represented by the above formulas (7) and (8) include the following. That is, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, di-1,2-propylene glycol, tri-1,2-propylene glycol, tetra-1, 2-propylene glycol, hexa-1,2-propylene glycol, di-1,3-propylene glycol, tri-1,3-propylene glycol, tetra-1,3-propylene glycol, di-1,3-butylene glycol, Tri-1,3-butylene glycol, hexa-1,3-butylene glycol, polyethylene glycol having a weight average molecular weight of 1000, polyethylene glycol having a weight average molecular weight of 1500, poly having a weight average molecular weight of 2,000 Tylene glycol, polyethylene glycol having a weight average molecular weight of 3000, polyethylene glycol having a weight average molecular weight of 7500, polypropylene glycol having a weight average molecular weight of 400, polypropylene glycol having a weight average molecular weight of 700, polypropylene glycol having a weight average molecular weight of 1000, polypropylene glycol having a weight average molecular weight of 2000 , Polypropylene glycol having a weight average molecular weight of 3000, polypropylene glycol having a weight average molecular weight of 4000, and the like.

Specific examples of the polyether diol compound represented by the formula (9) include those shown below.
That is, Sanyo Chemical Industries, Ltd. (trade name) PTMG650, PTMG1000, PTMG2000, PTMG3000, and the like.

  Specific examples of the polyether diol compound represented by the formula (10) include those shown below. That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole PE-61, New Pole PE-62, New Pole PE-64, New Pole PE-68, New Pole PE-71, New Pole PE-74, New Pole PE-75, New Pole PE-78, New Pole PE-108, New Pole PE-128, New Pole PE-61, and the like.

Specific examples of the polyether diol compound represented by the formula (11) include those shown below.
That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole BPE-20, New Pole BPE-20F, New Pole BPE-20NK, New Pole BPE-20T, New Pole BPE-20G, New Pole BPE-40, New Pole BPE-60, New Pole BPE-100, New Pole BPE-180, New Pole BPE-2P, New Pole BPE-23P, New Pole BPE-3P, New Pole BPE-5P, and the like.

  Specific examples of the random copolymer of ethylene oxide and propylene oxide having a hydroxyl group at the terminal include the following. That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole 50HB-100, New Pole 50HB-260, New Pole 50HB-400, New Pole 50HB-660, New Pole 50HB-2000, New Pole 50HB-5100, etc. It is.

  Examples of the polyester diol compound include compounds represented by formulas (12) and (13).

In formulas (12) and (13), L ² , L ³ and L ⁴ may be the same or different.
Represents a divalent aliphatic or aromatic hydrocarbon group, and L ⁵ represents a divalent aliphatic hydrocarbon group. Preferably, L ^{2 to} L ⁴ each represent an alkylene group, an alkenylene group, an alkynylene group, or an arylene group, and L ⁵ represents an alkylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ^{2 to} L ⁵ . n1 and n2 are each an integer of 2 or more, preferably an integer of 2 to 100.

  As the polycarbonate diol compound, there is a compound represented by the formula (14).

In the formula (14), L ⁶ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group. Preferably, L ⁶ represents an alkylene group, an alkenylene group, an alkynylene group or an arylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ⁶ . n3 is an integer of 2 or more, and preferably represents an integer of 2 to 100.

  Specific examples of the diol compound represented by the above formula (12), (13) or (14) include (Exemplary Compound No. 1) to (Exemplary Compound No. 18) shown below. N in the specific examples represents an integer of 2 or more.

  Furthermore, the specific binder polymer can be provided with a crosslinking property in order to improve the film strength of the image area. In order to give the specific binder polymer crosslinkability, a crosslinkable functional group may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization or may be introduced by a polymer reaction.

  Here, the crosslinkable functional group is a group that crosslinks the binder polymer in the process of radical polymerization reaction that occurs in the photosensitive layer when the lithographic printing plate precursor is exposed. Although it will not specifically limit if it is a group of such a function, For example, an ethylenically unsaturated bond group, an epoxy group, etc. are mentioned as a functional group which can be addition-polymerized. Moreover, the functional group which can become a radical by light irradiation may be sufficient, As such a crosslinkable functional group, a thiol group, a halogen group, an onium salt structure etc. are mentioned, for example. Especially, an ethylenically unsaturated bond group is preferable and the functional group represented by the following general formula (i)-(iii) is especially preferable.

In the general formula (i), R ^{1 to} R ³ each independently represents a hydrogen atom or a monovalent organic group, and R ¹ is preferably a hydrogen atom or an alkyl which may have a substituent. A hydrogen atom or a methyl group is preferable because of high radical reactivity. R ² and R ³ are each independently a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an optionally substituted alkyl group, or a substituted group. An aryl group that may have a group, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

X represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² represents a hydrogen atom or a monovalent organic group. Here, examples of the monovalent organic group include an alkyl group which may have a substituent. Among them, R ¹² is a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group having a high radical reactivity. This is preferable.

  Here, examples of the substituent that can be introduced include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, an alkylamino group, an arylamino group, a carboxyl group, an alkoxycarbonyl group, A sulfo group, a nitro group, a cyano group, an amide group, an alkylsulfonyl group, an arylsulfonyl group and the like can be mentioned.

In the general formula (ii), R ^{4 to} R ⁸ each independently represents a hydrogen atom or a monovalent organic group, and R ^{4 to} R ⁸ are preferably a hydrogen atom, a halogen atom, an amino group, or a dialkyl. Amino group, carboxyl group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, alkyl group which may have a substituent, aryl group which may have a substituent, alkoxy which may have a substituent A group, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, Examples include an arylsulfonyl group which may have a substituent. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group which may have a substituent, and an aryl which may have a substituent Group is preferred.

Examples of the substituent that can be introduced are the same as those in the general formula (i). Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —. R ¹² has the same meaning as R ^{12 in} formula (i), and preferred examples are also the same.

In the general formula (iii), R ⁹ represents a hydrogen atom or a monovalent organic group, and preferably includes a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom A methyl group is preferred because of high radical reactivity. R ¹⁰ and R ¹¹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or an alkyl group which may have a substituent. An aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, An arylamino group which may have, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, etc. are mentioned, among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable because of high radical reactivity.

Here, examples of the substituent that can be introduced are the same as those in the general formula (i). Further, Z is an oxygen atom, a sulfur atom, -N (R ¹³⁾ -, or a phenylene group which may have a substituent. Examples of R ¹³ include an alkyl group which may have a substituent. Among them, a methyl group, an ethyl group, and an isopropyl group are preferable because of high radical reactivity.

  Among the above, the specific binder polymer having crosslinkability is more preferably a (meth) acrylic acid copolymer having a crosslinkable functional group in the side chain and polyurethane.

  The specific binder polymer having crosslinkability is, for example, a free radical (polymerization initiation radical or a growth radical in the polymerization process of a polymerizable compound) is added to the crosslinkable functional group, and the polymerization chain of the polymerizable compound is directly between the polymers. Addition polymerization is carried out to form a cross-link between polymer molecules and cure. Alternatively, atoms in the polymer (for example, hydrogen atoms on carbon atoms adjacent to the crosslinkable functional group) are extracted by free radicals to form polymer radicals that are bonded to each other, thereby causing crosslinking between polymer molecules. Forms and cures.

  The specific binder polymer preferably has a mass average molecular weight of 5000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1000 or more, preferably 2000 to 250,000. Is more preferable. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10. The specific binder polymer may be any of a random polymer, a block polymer, a graft polymer, and the like, but is preferably a random polymer.

  The specific binder polymer may be used alone or in combination of two or more.

  In the specific binder, a repeating unit having a positively charged nitrogen atom (preferably a repeating unit having a structure represented by the general formulas (1) to (4)) is 0 for all the repeating units constituting the specific binder. It is preferable to contain 1 to 90 mol%, more preferably 3 to 50 mol%, still more preferably 5 to 30 mol%. Moreover, as a repeating unit which has an amino group, it is preferable to contain 0.01-90 mol%, it is more preferable to contain 0.1-50 mol%, and it is still more preferable to contain 1-30 mol%.

The content of the specific binder polymer is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and still more preferably 10 to 60% by mass with respect to the total solid content of the photosensitive layer.

Specific examples of the specific binder polymer containing the structures represented by the general formulas (1) to (4) as repeating units are listed below, but are not limited thereto.
The mass average molecular weight (Mw) in the table is measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.
In PB-1 to 103, the numerical value described together with the compound is the reaction ratio (mol%) of each constituent component. In the table, for example, “PPG1000” represents polypropylene glycol having an average molecular weight of 1000.

  Below, the synthesis example of the specific binder polymer of this invention is shown.

<Synthesis of Exemplary Compound (PA-1)>
A 500 mL three-necked flask equipped with a condenser and a stirrer was charged with 135 g of 1-methoxy-2-propanol and heated to 70 ° C. Under nitrogen flow, methyl acrylate 25.83 g, 3- (methacryloyloxy) propyltrimethylammonium chloride 33.26 g, 3-dimethylaminopropyl methacrylate 8.56 g, V-65 (trade name: Wako Pure Chemical Co., Ltd. polymerization initiator) 0.62
A solution prepared by dissolving g in 135 g of 1-methoxy-2-propanol was added dropwise over 2.5 hours. The mixture was further reacted at 70 ° C. for 2 hours. Next, the reaction solution was poured into water to precipitate a copolymer. This was collected by filtration, washed and dried to obtain a binder polymer (PA-1). It was confirmed from the NMR spectrum, IR spectrum, and GPC that the product was the object.

<Synthesis of Exemplary Compound (PB-71)>
In a 500 mL three-necked flask equipped with a condenser and a stirrer, 56 g of MEK, 20.00 g of polypropylene glycol (average molecular weight 1000), 7.36 g of 3- (N, N-diethylamino) -1,2-propanediol, BLEMMER GLM (manufactured by NOF Corporation) ) 4.81 g, 20.62 g of methylenediphenyl 4,4′-diisocyanate, 3.46 g of hexamethylene diisocyanate, 0.0442 g of 2,5-di-tert-butylbenzoquinone were introduced, and the reaction solution was brought to 50 ° C. to obtain a homogeneous solution. . Two drops of Neostan (manufactured by Nitto Kasei Co., Ltd .: bismuth catalyst) were added to the reaction solution and reacted at 70 ° C. for 2 hours. Methanol (3.00 g) was added to the reaction solution to quench the reaction, and then MEK (75 g), MFG (94 g), and camphorsulfonic acid (9.29 g) were added. The reaction solution was poured into 10 L of water to precipitate polyurethane. This is filtered. Washing and drying were performed to obtain a binder polymer (PB-71). It was confirmed from the NMR spectrum, IR spectrum, and GPC that the product was the object.

(Compound having an ethylenically unsaturated bond)
The compound having an ethylenically unsaturated bond (hereinafter also referred to as a polymerizable compound) used in the photosensitive layer in the invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is terminally ethylenically unsaturated. It is selected from compounds having at least one bond, preferably two or more bonds. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or copolymers thereof, or mixtures thereof. Examples of monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably unsaturated carboxylic acids. An ester of an acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, isocyanuric acid ethylene oxide (EO) There are modified triacrylates, polyester acrylate oligomers and the like.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include, for example, aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, JP-A-59- Those having an aromatic skeleton described in JP-A No. 5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.
Furthermore, the ester monomers described above can also be used as a mixture.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

  Further, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable. Specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinylurethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula (A) to a polyisocyanate compound having two or more isocyanate groups Etc.

_{CH 2 = C (R 4)} COOCH 2 CH (R 5) OH (A)
(However, R ₄ and R ₅ represent H or CH _3. )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56- Urethane compounds having an ethylene oxide skeleton described in Japanese Patent No. 17654, Japanese Patent Publication No. 62-39417, and Japanese Patent Publication No. 62-39418 are also suitable. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the case, it is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and JP-A-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. In addition, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid-based compounds described in JP-A-2-25493 are also included. Can be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

About these polymerizable compounds, the details of usage such as the structure, single use or combination, addition amount and the like can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of sensitivity, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable. A method of adjusting both sensitivity and strength by using a compound) is also effective.
In addition, the compatibility and dispersibility with other components in the photosensitive layer (for example, binder polymer, polymerization initiator, colorant, etc.), the selection and use method of the polymerizable compound is an important factor. In some cases, the compatibility can be improved by using a low-purity compound or using two or more of them together. In addition, a specific structure may be selected for the purpose of improving adhesion to a support or a protective layer described later. In addition, the use method of the polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging, refractive index change, surface adhesiveness, etc. The layer configuration and coating method such as undercoating and overcoating can be considered.

  The polymerizable compound is preferably used in the range of 5 to 75% by mass, more preferably 25 to 70% by mass, and particularly preferably 30 to 60% by mass with respect to the total solid content of the photosensitive layer.

(Polymerization initiator)
The photosensitive layer of the present invention contains a polymerization initiator (hereinafter also referred to as an initiator compound). The initiator compound is a compound that undergoes a chemical change through the action of electron transfer, energy transfer, heat generation, etc. caused by the electronic excitation state of the sensitizing dye, and generates at least one selected from radicals, acids, and bases. is there. Hereinafter, radicals, acids, and bases generated in this way are simply referred to as active species. When the initiator compound is not present or when only the initiator compound is used alone, practically sufficient sensitivity cannot be obtained. As one mode in which a sensitizing dye and an initiator compound are used in combination, they can be used as a single compound by an appropriate chemical method (such as linking a sensitizing dye and an initiator compound through a chemical bond). It is.

  Usually, many of these initiator compounds are considered to generate active species through the initial chemical processes represented by the following (1) to (3). (1) Reductive decomposition of the initiator compound based on the electron transfer reaction from the electronically excited state of the sensitizing dye to the initiator compound, (2) Electron transfer from the initiator compound to the electronically excited state of the sensitizing dye (3) decomposition of the initiator compound from the electronically excited state based on energy transfer from the electronically excited state of the sensitizing dye to the initiator compound. Although it is often ambiguous as to which type of (1) to (3) each individual initiator compound belongs, the sensitizing dye in the present invention is extremely in combination with any of these types of initiator compounds. Shows a high sensitizing effect.

  As the initiator compound in the present invention, those known to those skilled in the art can be used without limitation, and specifically include, for example, trihalomethyl compounds, carbonyl compounds, organic peroxides, azo compounds, azide compounds, metallocene compounds. , Hexaarylbiimidazole compounds, organic boron compounds, disulfone compounds, oxime ester compounds, onium salt compounds, and iron arene complexes. Among these, at least one selected from the group consisting of hexaarylbiimidazole compounds, onium salts, trihalomethyl compounds, and metallocene compounds is preferable, and hexaarylbiimidazole compounds are particularly preferable. Two or more of the above polymerization initiators can be used in combination as appropriate.

Examples of the hexaarylbiimidazole compounds include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4 ′, 5. , 5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2, 2'-bis (o, o'-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4', 5,5 ' -Te Raphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-trifluorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole and the like.
The hexaarylbiimidazole compound is particularly preferably used in combination with a sensitizing dye having a maximum absorption at 300 to 450 nm.

  The onium salt suitably used in the present invention (in the present invention, functions as an ionic polymerization initiator, not as an acid generator) is represented by the following general formulas (RI-I) to (RI-III). Onium salt.

In the formula (RI-I), Ar ₁₁ represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include an alkyl group having 1 to 12 carbon atoms and a carbon number. 1-12 alkenyl group, C1-C12 alkynyl group, C1-C12 aryl group, C1-C12 alkoxy group, C1-C12 aryloxy group, halogen atom, C1-C1 12 alkylamino groups, C1-C12 dialkylamino groups, C1-C12 alkylamide groups or arylamide groups, carbonyl groups, carboxyl groups, cyano groups, sulfonyl groups, C1-C12 thioalkyl groups And a thioaryl group having 1 to 12 carbon atoms. Z ₁₁ ⁻ represents a monovalent anion, and specific examples include halogen ions, perchlorate ions, borate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Of these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion and sulfinate ion are preferable from the viewpoint of stability.

In the formula (RI-II), Ar ₂₁ and Ar ₂₂ each independently represent an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include 1 to 12 alkyl groups, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 1 to 12 carbon atoms, Halogen atom, C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl group, cyano group, sulfonyl group, carbon Examples thereof include a thioalkyl group having 1 to 12 carbon atoms and a thioaryl group having 1 to 12 carbon atoms. Z ₂₁ ⁻ represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among them, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable in terms of stability and reactivity.

In the formula (RI-III), R ₃₁ , R ₃₂ and R ₃₃ are each independently an aryl group, alkyl group, alkenyl group or alkynyl having 20 or less carbon atoms, which may have 1 to 6 substituents. Represents a group. Among them, an aryl group is preferable from the viewpoint of reactivity and stability. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, Aryloxy group having 1 to 12 carbon atoms, halogen atom, alkylamino group having 1 to 12 carbon atoms, dialkylamino group having 1 to 12 carbon atoms, alkylamide group or arylamide group having 1 to 12 carbon atoms, carbonyl group, carboxyl Group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms. Z ₃₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoints of stability and reactivity. More preferred are the carboxylate ions described in JP-A No. 2001-343742, and particularly preferred are the carboxylate ions described in JP-A No. 2002-148790.
The onium salt is particularly preferably used in combination with an infrared absorber having a maximum absorption at 750 to 1400 nm.

Other polymerization initiators include JP 2007-171406, JP 2007-206216, JP 2007-206217, JP 2007-225701, JP 2007-225702, JP 2007-316582, and JP 2007-328243. The polymerization initiators described in each of the above publications can be preferably used.

The polymerization initiator in the present invention is preferably used alone or in combination of two or more.
The amount of the polymerization initiator used in the photosensitive layer in the present invention is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, based on the total solid content of the photosensitive layer. More preferably, it is 1.0 mass%-10 mass%.

(Sensitizing dye)
The photosensitive layer of the present invention preferably contains a sensitizing dye. For example, by adding a sensitizing dye having a maximum absorption at 300 to 450 nm, a sensitizing dye having a maximum absorption at 500 to 600 nm, and an infrared absorber having a maximum absorption at 750 to 1400 nm, each is normally used in the industry. It is possible to provide a high-sensitivity lithographic printing plate corresponding to the 405 nm violet laser, 532 nm green laser, and 803 nm IR laser.
First, a sensitizing dye having a maximum absorption in the wavelength region of 350 to 450 nm will be described. Examples of such a sensitizing dye include merocyanine dyes, benzopyrans, coumarins, aromatic ketones, anthracenes, and the like.

  Of the sensitizing dyes having an absorption maximum in a wavelength range of 360 nm to 450 nm, a dye more preferable from the viewpoint of high sensitivity is a dye represented by the following general formula (IX).

(In the general formula (IX), A represents an aromatic ring group or a heterocyclic group which may have a substituent, and X represents an oxygen atom, a sulfur atom or N- (R ₃ ). R ₁ , R ₂ and R ₃ each independently represent a monovalent nonmetallic atomic group, and A and R ₁ and R ₂ and R ₃ are bonded to each other to form an aliphatic or aromatic ring. May be good.)

General formula (IX) will be described in more detail. R ₁ , R ₂ and R ₃ are each independently a monovalent nonmetallic atomic group, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group. Represents a substituted or unsubstituted aromatic heterocyclic residue, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a hydroxyl group, or a halogen atom.

Next, A in the general formula (IX) will be described. A represents an aromatic ring group or a heterocyclic group which may have a substituent. Specific examples of the aromatic ring or heterocyclic ring which may have a substituent include R ₁ in the general formula (IX). , R ₂ and R ₃ are the same.

  As specific examples of such sensitizing dyes, compounds described in JP-A-2007-58170, 0047 to 0053 are preferably used.

  Furthermore, sensitizing dyes represented by the following general formulas (V) to (VII) can also be used.

In formula (V), R ^{1 to} R ¹⁴ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a cyano group or a halogen atom. However, at least one of R ^{1 to} R ¹⁰ represents an alkoxy group having 2 or more carbon atoms.
In the formula (VI), R ^{15 to} R ³² each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a cyano group, or a halogen atom. However, at least one of R ^{15 to} R ²⁴ represents an alkoxy group having 2 or more carbon atoms.

In formula (VII), R ¹ , R ² and R ³ each independently represents a halogen atom, an alkyl group, an aryl group, an aralkyl group, an —NR ⁴ R ⁵ group or an —OR ⁶ group, and R ⁴ , R ⁵ And R ⁶ each independently represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and k, m and n each represents an integer of 0 to 5.

Further, as described in JP 2007-171406, JP 2007-206216, JP 2007-206217, JP 2007-225701, JP 2007-225702, JP 2007-316582, and JP 2007-328243. Sensitizing dyes can also be preferably used.
The preferred addition amount of the sensitizing dye is preferably 0.05 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and most preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the total solid content of the photosensitive layer. It is the range of mass parts.

Subsequently, a sensitizing dye having a maximum absorption at 750 to 1400 nm that is preferably used in the present invention will be described in detail.
The sensitizing dye used here is highly sensitive to infrared laser irradiation (exposure) and is in an electronically excited state. The electron transfer, energy transfer, heat generation (photothermal conversion function), etc., associated with the electronically excited state are the photosensitive layer. It is presumed that it acts on a polymerization initiator coexisting therein to cause a chemical change in the polymerization initiator to generate a radical. In any case, the addition of a sensitizing dye having a maximum absorption at 750 to 1400 nm is particularly suitable for plate making directly drawn with an infrared laser beam having a wavelength of 750 to 1400 nm, and the conventional lithographic printing plate precursor Compared with this, high image forming properties can be exhibited.

  The infrared absorber is preferably a dye or pigment having an absorption maximum at a wavelength of 750 nm to 1400 nm.

As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, etc. Is mentioned.
Particularly preferred among these dyes are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferred, and particularly preferred examples include cyanine dyes represented by the following general formula (a).

In the general formula (a), X ¹ represents a hydrogen atom, a halogen atom, -NPh ₂ , X ² -L ¹ or a group shown below. Here, X ² represents an oxygen atom, a nitrogen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or 1 to 1 carbon atom containing a hetero atom. 12 hydrocarbon groups are shown. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. X _a ^- is Z _a which will be described below ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. In view of storage stability of the photosensitive layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring or It is particularly preferable that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Za ⁻ represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by formula (a) has an anionic substituent in its structure and charge neutralization is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a hexagonal salt, in view of the storage stability of the photosensitive layer coating solution. Fluorophosphate ions and aryl sulfonate ions. In addition, the thing which does not contain a halogen ion as a counter ion is especially preferable.

  Specific examples of the cyanine dye represented by formula (a) that can be suitably used include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969.

  Further, other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057 described above.

  Examples of pigments include commercially available pigment and color index (CI) manuals, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), “Printing” The pigments described in "Ink Technology", published by CMC Publishing, 1984) can be used.

Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

  These pigments may be used without surface treatment, or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Application of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. Within this preferred particle size range, excellent dispersion stability of the pigment in the photosensitive layer can be obtained, and a uniform photosensitive layer can be obtained.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

  These infrared absorbers may be added to the same layer as other components, or another layer may be provided and added thereto.

  From the viewpoint of uniformity in the photosensitive layer and durability of the photosensitive layer, these infrared absorbers are 0.01 to 50% by mass, preferably 0.1 to 10% by mass, based on the total solid content constituting the photosensitive layer. In the case of a dye, it is particularly preferably 0.5 to 10% by mass, and in the case of a pigment, it is particularly preferably 0.1 to 10% by mass.

<Microcapsule>
In the present invention, as a method for causing the photosensitive layer to contain the above-described photosensitive layer constituents and other constituents described later, for example, as described in JP-A Nos. 2001-277740 and 2001-277742, A part of the components can be encapsulated in microcapsules and added to the photosensitive layer. In that case, each component can be contained in any ratio in and out of the microcapsule.

As a method for microencapsulating the photosensitive layer constituent components, known methods can be applied. For example, as a method for producing microcapsules, a method using coacervation found in U.S. Pat. Nos. 2,800,547 and 2,800,498, U.S. Pat. No. 3,287,154, JP-B-38-19574, 42-446 by the interfacial polymerization method, US Pat. No. 3,418,250, US Pat. No. 3,660,304 by polymer precipitation method, US Pat. No. 3,796,669, isocyanate polyol A method using a wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, and a urea-formaldehyde system found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802. Or urea formaldehyde-resorcino A method using a system wall forming material, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, as shown in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method using monomer polymerization, spray drying method found in British Patent No. 930422, US Pat. No. 3,111,407, electrolytic dispersion cooling method seen in British Patent Nos. 952807 and 967074, etc. However, it is not limited to these.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. Moreover, you may introduce | transduce into the microcapsule wall the compound which has crosslinkable functional groups, such as an ethylenically unsaturated bond which can be introduce | transduced into said water-insoluble polymer.

  The average particle size of the microcapsules is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is further more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, good resolution and stability over time can be obtained.

<Other photosensitive layer components>
The photosensitive layer of the present invention can further contain various additives as required. Additives include surfactants for promoting developability and improving the surface of the coating, hydrophilic polymers for improving developability and dispersion stability of microcapsules, and visual and non-image areas visible A coloring agent and a print-out agent, a polymerization inhibitor for preventing unnecessary thermal polymerization of radically polymerizable compounds during production or storage of the photosensitive layer, a higher fat derivative for preventing polymerization inhibition by oxygen, Add inorganic fine particles to improve the strength of the cured film in the image area, hydrophilic low molecular weight compounds to improve developability, co-sensitizers and chain transfer agents to improve sensitivity, plasticizers to improve plasticity, etc. be able to. Any of these compounds can be used, for example, JP 2007-171406, JP 2007-206216, JP 2007-206217, JP 2007-225701, JP 2007-225702, JP 2007-316582. The compounds described in JP-A-2007-328243 can be used.

As the compound that acts as a chain transfer agent, for example, a compound group having SH, PH, SiH, GeH in the molecule is used. These can donate hydrogen to low-activity radical species to generate radicals, or can be oxidized and then deprotonated to generate radicals.
In the photosensitive layer of the present invention, in particular, thiol compounds (for example, 2-mercaptobenzimidazoles, 2-mercaptobenzthiazoles, 2-mercaptobenzoxazoles, 3-mercaptotriazoles, 5-mercaptotetrazoles, etc.) Can be preferably used as a chain transfer agent.
Especially, the thiol compound represented by the following general formula (I) is used especially suitably. By using this thiol compound as a chain transfer agent, the problem of odor and sensitivity reduction due to evaporation from the photosensitive layer and diffusion to other layers are avoided, and it has excellent storage stability and high sensitivity and high printing durability. A lithographic printing plate precursor is obtained.

  In general formula (I), R represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and A represents a 5-membered ring having a carbon atom together with an N = CN moiety. Alternatively, it represents an atomic group that forms a 6-membered heterocycle, and A may further have a substituent.

  More preferably, those represented by the following general formula (IA) or general formula (IB) are used.

  In general formulas (IA) and (IB), R represents an alkyl group which may have a substituent or an aryl group which may have a substituent, and X represents a halogen atom, an alkoxyl group or a substituent. The alkyl group which may have or the aryl group which may have a substituent is represented.

  Specific examples of the compound represented by formula (I) are shown below, but the present invention is not limited to these.

  The amount of these thiol compounds used is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, based on the total solid content of the photosensitive layer. More preferably, it is 1.0-10 mass%.

<Formation of photosensitive layer>
The photosensitive layer of the present invention is formed by preparing or applying a coating solution by dispersing or dissolving the necessary components described above in a solvent. Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The photosensitive layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeatedly applying and drying a plurality of times.

The coating, the photosensitive layer coating amount on the support obtained after drying (solid content) may be varied according to the intended purpose, generally 0.3 to 3.0 g / m ² is preferred. Within this range, good sensitivity and good film properties of the photosensitive layer can be obtained.
Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

<Protective layer>
In the lithographic printing plate precursor according to the invention, a protective layer (oxygen blocking layer) is preferably provided on the photosensitive layer in order to block diffusion and penetration of oxygen that hinders the polymerization reaction during exposure. The protective layer used in the present invention preferably has an oxygen permeability A at 25 ° C. and 1 atm of 1.0 ≦ A ≦ 20 (mL / m ² · day). When the oxygen permeability A is extremely low at less than 1.0 (mL / m ² · day), unnecessary polymerization reaction occurs at the time of production and raw storage, and unnecessary fogging and image streaking occur during image exposure. The problem that fatness arises arises. Conversely, when the oxygen permeability A exceeds 20 (mL / m ² · day) and is too high, the sensitivity is lowered. The oxygen permeability A is more preferably in the range of 1.5 ≦ A ≦ 12 (mL / m ² · day), further preferably 2.0 ≦ A ≦ 10.0 (mL / m ² · day). In addition to the oxygen permeability described above, the properties desired for the protective layer further do not substantially inhibit the transmission of light used for exposure, have excellent adhesion to the photosensitive layer, and are easy in the development process after exposure. It is desirable that it can be removed. The device concerning such a protective layer has been conventionally made, and is described in detail in US Pat. No. 3,458,311 and JP-B-55-49729.

  As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, vinyl alcohol / vinyl phthalate copolymer, vinyl acetate / vinyl are used. Examples include water-soluble polymers such as alcohol / vinyl phthalate copolymer, vinyl acetate / crotonic acid copolymer, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, polyacrylic acid, polyacrylamide, etc. Or they can be mixed. Of these, the use of polyvinyl alcohol as the main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability.

  The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. Specific examples of polyvinyl alcohol include those that are hydrolyzed by 71 to 100 mol% and have a polymerization repeating unit in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA- 420, PVA-613, L-8 and the like, and these can be used alone or in combination. In a preferred embodiment, the content of polyvinyl alcohol in the protective layer is 20 to 95% by mass, and more preferably 30 to 90% by mass.

Moreover, well-known modified polyvinyl alcohol can also be used preferably. For example, various hydrophilic modification sites such as anion modification sites modified with anions such as carboxyl groups and sulfo groups, cation modification sites modified with cations such as amino groups and ammonium groups, silanol modification sites, and thiol modification sites are randomly selected. Polyvinyl alcohol having various degrees of polymerization, the anion-modified site, the cation-modified site, the silanol-modified site, the thiol-modified site, the alkoxyl-modified site, the sulfide-modified site, and the ester modification of vinyl alcohol and various organic acids. Examples thereof include polyvinyl alcohol having various polymerization degrees having various modified sites such as a site, an ester-modified site of the anion-modified site and alcohols, an epoxy-modified site, and the like.

  As a component used by mixing with polyvinyl alcohol, polyvinyl pyrrolidone or a modified product thereof is preferable from the viewpoint of oxygen barrier properties and development removability, and the content in the protective layer is 3.5 to 80% by mass, preferably 10 to 60%. It is 15 mass%, More preferably, it is 15-30 mass%.

  Components of the protective layer (selection of PVA, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of the PVA used (the higher the content of the unsubstituted vinyl alcohol unit in the protective layer), the higher the film thickness, the higher the oxygen barrier property and the more advantageous in terms of sensitivity. The molecular weight of the (co) polymer such as polyvinyl alcohol (PVA) can be in the range of 2000 to 10 million, preferably in the range of 20,000 to 3 million.

  As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added.

  In addition, adhesion to the image area and scratch resistance are extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on an oleophilic photosensitive layer, film peeling due to insufficient adhesion tends to occur, and the peeled part causes defects such as poor film hardening due to inhibition of oxygen polymerization. On the other hand, various proposals have been made to improve the adhesion between these two layers. For example, in U.S. Patent Application No. 292,501 and U.S. Patent Application No. 44,563, an acrylic emulsion or a water-insoluble vinyl pyrrolidone-vinyl acetate copolymer is contained in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and laminating on a photosensitive layer. Any of these known techniques can be applied to the protective layer in the present invention. Such a coating method for the protective layer is described in detail in, for example, US Pat. No. 3,458,311 and Japanese Patent Publication No. 55-49729.

Furthermore, the protective layer in the lithographic printing plate precursor according to the invention preferably contains an inorganic stratiform compound for the purpose of improving oxygen barrier properties and photosensitive layer surface protection.
Here, the inorganic layered compound is a particle having a thin flat plate shape. For example, the following general formula A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂
[However, A is any one of K, Na, and Ca, B and C are any of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. And mica groups such as natural mica and synthetic mica, talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by the formula 3MgO.4SiO.H ₂ O.
In the present invention, among the inorganic layered compounds described above, fluorine-based swellable synthetic mica that is a synthetic inorganic layered compound is particularly useful.
The aspect ratio of the inorganic layered compound of the present invention is preferably 20 or more, more preferably 100 or more, and particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  As for the particle diameter of the inorganic stratiform compound used in the present invention, the average major axis is 0.3 to 20 μm, preferably 0.5 to 10 μm, particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. For example, among inorganic layered compounds, the size of the swellable synthetic mica that is a representative compound is about 1 to 50 nm in thickness and about 1 to 20 μm in surface size.

  When the inorganic layered compound particles having such a large aspect ratio are contained in the protective layer, the coating film strength is improved, and the permeation of oxygen and moisture can be effectively prevented. Deterioration is prevented, and even when stored for a long time under high-humidity conditions, the storage stability of the planographic printing plate precursor does not deteriorate due to changes in humidity, and the storage stability is excellent.

  It is preferable that content of the inorganic stratiform compound in a protective layer is 5/1-1/100 by mass ratio with respect to the quantity of the binder used for a protective layer. Even when a plurality of types of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass ratio.

  The dispersion method of the inorganic stratiform compound used for the protective layer is disclosed in JP 2007-171406, JP 2007-206216, JP 2007-206217, JP 2007-225701, JP 2007-225702, JP 2007-316582, JP The method described in 2007-328243 etc. is used.

The coating amount of the protective layer is preferably in the range of 0.05 to 10 g / m ^{2 in} terms of the coating amount after drying. When the inorganic layered compound is contained, 0.1 to 0.5 g / The range of m ² is more preferable, and when the inorganic layered compound is not contained, the range of 0.5 to 5 g / m ² is more preferable.

[Support]
The support used in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like hydrophilic support. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. Preferable supports include a polyester film and an aluminum plate. Among these, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

  The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of different elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is preferably 10% by mass or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element. The composition of the aluminum plate is not specified, and a publicly known material can be used as appropriate.

  The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm, and even more preferably from 0.2 to 0.3 mm.

  Prior to using the aluminum plate, it is preferable to perform a surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it becomes easy to improve hydrophilicity and secure adhesion between the photosensitive layer and the support. Prior to the roughening treatment of the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like for removing rolling oil on the surface is performed as desired.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment for dissolving the surface electrochemically), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, an electrolyte concentration of 1 to 80% by mass solution, a liquid temperature of 5 to 70 ° C., a current density of 5 to 60 A / d m ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2. Within this range, good printing durability and good scratch resistance of the non-image area of the lithographic printing plate can be obtained.

  As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation and the like. If necessary, it contains a micropore enlargement treatment, a micropore sealing treatment, and a hydrophilic compound described in Japanese Patent Application Laid-Open Nos. 2001-253181 and 2001-322365. A surface hydrophilization treatment immersed in an aqueous solution can be selected as appropriate. Of course, these enlargement processing and sealing processing are not limited to those described above, and any conventionally known method can be performed.

Sealing treatment includes vapor sealing, single treatment with zirconic fluoride, treatment with an aqueous solution containing an inorganic fluorine compound such as treatment with sodium fluoride, vapor sealing with addition of lithium chloride, sealing with hot water. Hole processing is also possible.
Of these, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing treatment with hot water are preferable.

The hydrophilization treatment is described in the specifications of US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There are such alkali metal silicate methods. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, And a method of treating with polyvinylphosphonic acid as described in the specification of No. 272.

  When using a support with insufficient surface hydrophilicity such as a polyester film as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony, and a transition metal described in JP-A-2001-199175 A hydrophilic layer formed by coating a coating solution containing a colloid of oxide or hydroxide, or organic hydrophilicity obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer described in JP-A-2002-79772 A hydrophilic layer having a hydrophilic matrix, a hydrophilic layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or a metal oxide A hydrophilic layer made of an inorganic thin film having a surface is preferred. Arbitrariness. Among these, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or a hydroxide colloid is preferable.

  Moreover, when using a polyester film etc. as a support body of this invention, it is preferable to provide an antistatic layer in the hydrophilic layer side of a support body, the opposite side, or both sides. In the case where the antistatic layer is provided between the support and the hydrophilic layer, it also contributes to improving the adhesion with the hydrophilic layer. As the antistatic layer, a polymer layer in which metal oxide fine particles or a matting agent are dispersed as described in JP-A-2002-79772 can be used.

The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the photosensitive layer, good printing durability and good stain resistance can be obtained.
The color density of the support is preferably 0.15 to 0.65 as the reflection density value. Within this range, good image formability by preventing halation during image exposure and good plate inspection after development can be obtained.

(Undercoat layer)
In the lithographic printing plate precursor according to the invention, it is preferable to provide an undercoat layer of a compound containing a polymerizable group on a support. When an undercoat layer is used, the photosensitive layer is provided on the undercoat layer. The undercoat layer reinforces the adhesion between the support and the photosensitive layer in the exposed area, and easily peels the photosensitive layer from the support in the unexposed area, thereby improving the developability.
As the undercoat layer, specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, JP-A-2-304441. The phosphorus compound etc. which have the ethylenic double bond reactive group of description are mentioned suitably. Particularly preferable compounds include compounds having a polymerizable group such as a methacryl group or an allyl group and a support adsorbing group such as a sulfonic acid group, a phosphoric acid group, or a phosphoric acid ester. A compound having a hydrophilicity-imparting group such as an ethylene oxide group in addition to the polymerizable group and the support-adsorbing group can also be exemplified as a suitable compound.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 1 to 30 mg / m ^2.

[Back coat layer]
After the surface treatment is performed on the support or after the undercoat layer is formed, a back coat can be provided on the back surface of the support, if necessary.
Examples of the back coat include hydrolysis and polycondensation of organic polymer compounds described in JP-A-5-45885, organometallic compounds or inorganic metal compounds described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this manner is preferred. Among them, it is inexpensive to use a silicon alkoxy compound such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) _4. It is preferable in terms of easy availability.

[Plate making method]
A lithographic printing plate is prepared by subjecting the lithographic printing plate precursor according to the invention to image exposure and development. As the development processing, (1) a method of developing with an alkaline developer (pH is greater than 10), (2) a method of developing with a developer having a pH of 2 to 10, and (3) wet on a printing press. A method of developing while adding water and / or ink (on-press development) can be mentioned. In the present invention, a method of developing with a developer having a pH of 2 to 10 is used.
That is, the lithographic printing plate precursor of the present invention can be set on a printing machine and printed immediately after the protective layer and the photosensitive layer in the non-exposed area are removed together with a developer having a pH of 2 to 10. In the normal development process using the alkali developer of (1), the protective layer is removed by the pre-water washing process, then alkali development is performed, the alkali is removed by the post-water washing process, and the gum treatment is performed in the gumming process. And dried in the drying process. In the present invention, the developer contains a water-soluble polymer compound, and development and gumming are performed simultaneously. Therefore, the post-water washing step is not particularly required, and it is preferable to perform the drying step after developing and gumming in one bath. Further, the pre-water washing step is not particularly required, and the protective layer is preferably removed simultaneously with development and gumming. Moreover, after developing and gumming, it is preferable to perform drying after removing excess developer using a squeeze roller. The development of the photosensitive lithographic printing plate precursor according to the invention is carried out by immersing the exposed photosensitive lithographic printing plate precursor in a developer at a temperature of about 0 to 60 ° C., preferably about 15 to 40 ° C., according to a conventional method. For example, rubbing with a brush.
In addition, such processing in an automatic developing machine has an advantage that it is freed from dealing with development residue derived from the protective layer / photosensitive layer that occurs in the case of on-press development.

0254
The developer used in the present invention is an aqueous solution having a pH of 2 to 10. For example, water alone or an aqueous solution containing water as a main component (containing 60% by mass or more of water) is preferable. In particular, an aqueous solution having the same composition as that of a generally known fountain solution, a surfactant (anionic, nonionic, An aqueous solution containing a cationic system or the like, or an aqueous solution containing a water-soluble polymer compound is preferable. In particular, an aqueous solution containing both a surfactant and a water-soluble polymer compound is preferable. The pH of the developer is more preferably 3-8, and even more preferably 4-7.
When an acidic to neutral developer is used, it is preferable to contain either an organic acid or an inorganic acid. By containing an organic acid or an inorganic acid, developability can be improved during plate making, and it is possible to suppress the occurrence of stains in the non-image area of the plate that has been made.

  The anionic surfactant used in the developer of the present invention is not particularly limited, but dialkyl sulfosuccinates, alkyl sulfate esters and alkyl naphthalene sulfonates are preferably used.

  The cationic surfactant used in the developer of the present invention is not particularly limited, and conventionally known ones can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.

Nonionic surfactants used in the developer of the present invention include sorbitol and / or sorbitan fatty acid ester ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, dimethylsiloxane-ethylene oxide block copolymer, dimethylsiloxane- (propylene oxide). -Ethylene oxide) block copolymers and fatty acid esters of polyhydric alcohols are preferably used.

  Two or more surfactants may be used, and the ratio of the surfactant contained in the developer is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass.

  Examples of the water-soluble polymer compound used in the developer of the present invention include soybean polysaccharide, modified starch, gum arabic, dextrin, fibrin derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, pullulan. , Polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone, polyacrylamide and acrylamide copolymer, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride copolymer, etc. It is done.

  A well-known thing can be used for the said soybean polysaccharide, for example, there exists a brand name Soya Five (made by Fuji Oil Co., Ltd.) as a commercial item, and the thing of various grades can be used. What can be preferably used is one in which the viscosity of a 10% by mass aqueous solution is in the range of 10 to 100 mPa / sec.

  As the modified starch, known ones can be used, and starch such as corn, potato, tapioca, rice and wheat is decomposed with acid or enzyme in the range of 5 to 30 glucose residues per molecule, and further in an alkali. It can be made by a method of adding oxypropylene or the like.

  Two or more water-soluble polymer compounds can be used in combination. The content of the water-soluble polymer compound in the developer is preferably from 0.1 to 20% by mass, and more preferably from 0.5 to 10% by mass.

  Further, the developer of the present invention may contain an organic solvent. Examples of the organic solvent that can be contained include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (manufactured by Esso Chemical Co., Ltd.) or gasoline, kerosene, etc.), and aromatic hydrocarbons (toluene). , Xylene, etc.), halogenated hydrocarbons (methylene dichloride, ethylene dichloride, tricrene, monochlorobenzene, etc.) and polar solvents.

  If the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. If the developer contains an organic solvent, safety, ignition, From the viewpoint of property, the concentration of the solvent is preferably less than 40% by mass.

  In addition to the above, the developer of the present invention may contain a preservative, a chelate compound, an antifoaming agent, an organic acid, an inorganic acid, an inorganic salt, and the like.

  The developer described above can be used as a developer and developer replenisher for the exposed negative lithographic printing plate precursor, and is preferably applied to an automatic processor described later. When developing using an automatic processor, the developing solution becomes fatigued according to the amount of processing, so the processing capability may be restored using a replenisher or a fresh developer. This replenishing method is also preferably applied to the lithographic printing plate making method of the present invention.

The development treatment with an aqueous solution having a pH of 2 to 10 in the present invention can be preferably carried out by an automatic processor equipped with a developer supply means and a rubbing member. As the automatic processor, for example, an automatic processor described in JP-A-2-220061 and JP-A-60-59351, which performs a rubbing process while transporting a lithographic printing plate precursor after image recording, or a cylinder Examples thereof include an automatic processor described in US Pat. Nos. 5,148,746, 5,568,768 and British Patent 2,297,719, which rub the lithographic printing plate precursor after image recording set thereon while rotating a cylinder. Among these, an automatic processor using a rotating brush roll as the rubbing member is particularly preferable.

The rotating brush roll that can be preferably used in the present invention can be appropriately selected in consideration of the difficulty of scratching the image area and the stiffness of the support of the lithographic printing plate precursor. As the rotating brush roll, a known one formed by planting a brush material on a plastic or metal roll can be used. For example, as described in Japanese Patent Application Laid-Open No. 58-159533, Japanese Patent Application Laid-Open No. 3-100554, or Japanese Utility Model Publication No. 62-167253, metal or plastic in which brush materials are implanted in rows. A brush roll can be used in which the groove mold material is radially wound around a plastic or metal roll as a core without a gap.
The brush material includes plastic fibers (for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6.6 and nylon 6.10, polyacrylonitrile, poly (meth) acrylate, etc. Acrylic and polyolefin synthetic fibers such as polypropylene and polystyrene) can be used. For example, the fiber has a hair diameter of 20 to 400 μm and a hair length of 5 to 30 mm. Can be used.
Furthermore, the outer diameter of the rotating brush roll is preferably 30 to 200 mm, and the peripheral speed at the tip of the brush rubbing the plate surface is preferably 0.1 to 5 m / sec.
Moreover, it is preferable to use two or more rotating brush rolls.

  The rotating direction of the rotating brush roll used in the present invention may be the same or opposite to the conveying direction of the planographic printing plate precursor of the present invention. Thus, when two or more rotating brush rolls are used, it is preferable that at least one rotating brush roll rotates in the same direction and at least one rotating brush roll rotates in the opposite direction. This further ensures the removal of the heat sensitive layer in the non-image area. Furthermore, it is also effective to swing the rotating brush roll in the direction of the rotation axis of the brush roll.

  Although the temperature of the developer can be used at any temperature, it is preferably 10 ° C to 50 ° C.

  In the present invention, the lithographic printing plate after the rubbing treatment can be optionally washed with water, dried and desensitized. In the desensitizing treatment, a known desensitizing solution can be used.

  In addition, as the plate-making process of the lithographic printing plate from the lithographic printing plate precursor according to the present invention, the entire surface may be heated before exposure, during exposure, and between exposure and development, if necessary. By such heating, the image forming reaction in the photosensitive layer is promoted, and advantages such as improvement in sensitivity and printing durability and stabilization of sensitivity may occur. Further, for the purpose of improving the image strength and printing durability, it is also effective to subject the developed image to full post heating or full exposure. Usually, the heating before development is preferably performed under a mild condition of 150 ° C. or less. If the temperature is too high, problems such as covering up to the non-image area occur. Very strong conditions are used for heating after development. Usually, it is the range of 100-500 degreeC. If the temperature is low, sufficient image strengthening action cannot be obtained. If the temperature is too high, problems such as deterioration of the support and thermal decomposition of the image area occur.

Prior to the above development processing, the lithographic printing plate precursor is exposed imagewise by laser exposure through a transparent original image having a line image, a halftone dot image or the like, or by laser beam scanning by digital data.
A desirable light source wavelength is preferably 350 nm to 450 nm or 700 nm to 1200 nm. In the case of 350 nm to 450 nm, a lithographic printing plate precursor having a sensitizing dye having an absorption maximum in this region in the photosensitive layer is used, and in the case of 700 nm to 1200 nm, infrared absorption which is a sensitizing dye having absorption in this region. A lithographic printing plate precursor containing an agent is used. A semiconductor laser is suitable as a light source of 350 nm to 450 nm. As a light source of 700 nm to 1200 nm, a solid-state laser and a semiconductor laser that emit infrared rays are suitable.
The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

<Examples 1-17, Comparative Examples 1-4>
[Preparation of lithographic printing plate precursor type I]
An aluminum plate (material JIS A1050) having a thickness of 0.3 mm was etched by being immersed in 10% by weight sodium hydroxide at 60 ° C. for 25 seconds, washed with running water, neutralized with 20% by weight nitric acid, and then washed with water. . This was subjected to an electrolytic surface roughening treatment in a 1% by mass nitric acid aqueous solution using a sinusoidal alternating waveform current at an anode time electricity of 300 coulomb / dm ² . Subsequently, after dipping in a 1% by mass aqueous sodium hydroxide solution at 40 ° C. for 5 seconds and then in a 30% by mass sulfuric acid aqueous solution and desmutting at 60 ° C. for 40 seconds, the current density in a 20% by mass sulfuric acid aqueous solution was 2A / current density. Anodization was performed for 2 minutes so that the thickness of the anodized film was 2.7 g / m ² under the condition of dm ² . Then, it processed at 20 degreeC for 10 second with 1 mass% of sodium silicate aqueous solution. The center line average roughness (Ra) of the support thus obtained was measured using a needle having a diameter of 2 μm and found to be 0.25 μm (Ra indication according to JIS B0601).

Furthermore, after applying the following undercoat liquid (1) with a bar, it was oven-dried at 80 ° C. for 10 seconds to apply a dry coating amount of 15 mg / m ² , and a support having an undercoat layer used in the following experiments. Produced.

Undercoat liquid (1)
・ The following polymer compound (1) 0.017 g
・ Methanol 9.00 g
・ Water 1.00g

A photosensitive layer coating solution 1 having the following composition was bar coated on the aluminum support provided with the undercoat layer, followed by oven drying at 72 ° C. for 65 seconds to form a photosensitive layer having a dry coating amount of 1.2 g / m ^2. A protective layer coating solution 1 having the following composition is formed on the coating layer using a bar so that the dry coating amount is 0.75 g / m ^2, and then dried at 125 ° C. for 70 seconds for protection. A layer was formed to prepare a lithographic printing plate precursor type I series.

Photosensitive layer coating solution 1
-Specific binder polymer of the present invention (exemplary compounds described in Table 1) 0.50 g
・ Compound having ethylenically unsaturated bond 0.50 g
(Dipentaerythritol pentaacrylate; SR39 manufactured by Nippon Kayaku Co., Ltd.)
・ Radical polymerization initiator (I-1) 0.08g
Sensitizing dye (D-1) 0.06g
・ Chain transfer agent (S-1) 0.07g
・ 0.40 g of ε-phthalocyanine pigment dispersion
[Pigment: 15 parts by mass, Allyl methacrylate / methacrylic acid (80/20) copolymer as a dispersant: 10 parts by mass, Cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 parts by mass / 20 parts as a solvent Parts / 40 parts by mass]
・ Thermal polymerization inhibitor 0.01g
(N-nitrosophenylhydroxylamine aluminum salt)
・ Fluorine-based surfactant (F-1) 0.001 g
・ Polyoxyethylene-polyoxypropylene condensate 0.04g
(Asahi Denka Kogyo Co., Ltd., Pluronic L44)
・ Tetraethylammonium chloride 0.01g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

Protective layer coating solution 1
Polyvinyl alcohol (PVA-105 (manufactured by Kuraray Co., Ltd.), saponification degree 98 mol%, polymerization degree 500) 40 g
・ Polyvinylpyrrolidone (molecular weight 50,000) 5g
・ Poly [vinyl pyrrolidone / vinyl acetate (1/1) molecular weight 70,000]
0.5g
・ Surfactant (Emalex 710; manufactured by Nippon Emulsion Co., Ltd.)
0.5g
・ 950g of water

[Exposure, development and printing]
For each lithographic printing plate precursor type I series, use a 405 nm semiconductor laser with an output of 100 mW to perform imagewise exposure with varying energy density. After the laser exposure, place the lithographic printing plate precursor in an oven within 30 seconds and blow hot air. The entire surface of the lithographic printing plate precursor was heated by spraying and kept at 110 ° C. for 15 seconds.

Thereafter, using a developing solution 1 having the following composition, development processing was performed with an automatic developing processor having a structure shown in FIG. 1 to prepare a lithographic printing plate (without heating). The pH of the developer was 4.6. The automatic processor is an automatic processor having two rotating brush rolls. As the rotating brush roll, the first brush roll and the polybutylene terephthalate fiber (hair diameter 200 μm, hair length 17 mm). Using a brush roll with an outer diameter of 90 mm implanted with 200 mm / min in the same direction as the conveying direction (peripheral speed 0.94 m / sec at the tip of the brush), the second brush roll is made of polybutylene terephthalate Using a brush roll having an outer diameter of 60 mm in which fibers (hair diameter: 200 μm, hair length: 17 mm) were planted, it was rotated 200 times per minute in the direction opposite to the conveying direction (peripheral speed of the brush tip: 0.63 m / sec). . The transportation of the lithographic printing plate precursor was carried out at various transport speeds.
The developer was showered from the spray pipe with a circulation pump and supplied to the plate surface. The tank capacity of the developer was 10 liters.

Developer 1
・ Water 100.00g
・ Benzyl alcohol 1.00g
・ Polyoxyethylene naphthyl ether (oxyethylene average number n = 13) 1.00 g
・ Dioctylsulfosuccinate sodium salt 0.50 g
・ Gum arabic (Mw = 250,000) 1.00g
・ Ethylene glycol 0.50g
・ Primary ammonium phosphate 0.05g
・ Citric acid 0.05g
・ Ethylenediaminetetraacetate tetrasodium salt 0.05g

  Next, the planographic printing plate is attached to a printing machine SOR-M manufactured by Heidelberg, and dampening water (EU-3 (Etchi solution manufactured by FUJIFILM Corporation) / water / isopropyl alcohol = 1/89/10 (volume ratio). ) And TRANS-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.), and printing was performed at a printing speed of 6000 sheets per hour.

[Evaluation]
The lithographic printing plate precursor was evaluated for developability, sensitivity, printing durability and stain resistance as follows. The results are shown in Table 1.

<Developability>
Development was carried out at various conveying speeds as described above, and the cyan density of the non-image area was measured with a Macbeth densitometer. The transport speed at which the cyan density of the non-image area was equal to the cyan density of the aluminum substrate was determined and defined as developability. The evaluation of developability is represented by the relative developability defined as follows using Comparative Example 1 as a reference (1.0). A larger relative developability value indicates higher developability and better performance.
Relative developability = (target photosensitive material transport speed) / (reference photosensitive material transport speed)

<Sensitivity>
After 100 sheets were printed as described above and it was confirmed that a printed matter having no ink stains in the non-image area was obtained, 500 sheets were printed continuously. In the total 600th printed matter, the exposure amount with no unevenness in the ink density in the image area was measured as sensitivity. The sensitivity evaluation is expressed as a relative sensitivity defined as follows using Comparative Example 1 as a reference (1.0). The larger the relative sensitivity value, the higher the sensitivity and the better the performance.
Relative sensitivity = (sensitivity of standard photosensitive material / sensitivity of target photosensitive material)

<Print durability>
As the number of printed sheets was increased, the photosensitive layer was gradually worn out and the ink acceptability was lowered, so that the ink density in the printing paper was lowered. In a printing plate exposed at the same exposure (90 μJ / cm ² ), printing durability was evaluated by the number of printed sheets when the ink density (reflection density) was reduced by 0.1 from the start of printing. The evaluation of printing durability is represented by the relative printing durability defined as follows using Comparative Example 1 as a reference (1.0). The larger the relative printing durability number, the higher the printing durability.
Relative printing durability = (printing durability of target photosensitive material) / (printing durability of standard photosensitive material)

<Dirty>
After printing 500 sheets as described above, non-image areas with no ink stains are “◎”, “◎” are inferior to practical use, but “○” is practical, and some stains can be seen. The problem is indicated by “△”, and the dirty one is indicated by “×”.

<Reproducibility of image formation sensitivity>
A FUJIFILM Fuji step guide (gray scale whose transmission optical density changes discontinuously at ΔD = 0.15) manufactured by FUJIFILM Corporation is brought into close contact with the lithographic printing plate precursor obtained as described above. The sample was loaded on a Violet semiconductor laser setter Vx9600 (InGaN semiconductor laser 405 nm ± 10 nm emission / output 30 mW) manufactured by Electronic Imaging Ltd, and an image was drawn with an exposure amount of 90 μJ / cm ² .
Thereafter, the film was immersed in a developer having the above composition at 25 ° C. for 30 seconds, developed, and the maximum number of steps at which the image was completely removed was read. A lithographic printing plate precursor is prepared for each of 10 levels using polymers of different synthetic lots, and this evaluation is performed. The difference between the maximum value and the minimum value among the 10 levels of the maximum number of stages at which the image is completely removed is determined. Those with less than 0.5 steps were marked with “◯”, and those with more than 0.5 steps were marked with “×”.

  The results are shown in Table 1.

As shown in Table 1, it can be seen that by using the binder polymer of the present invention, it is possible to improve the developability and the printing durability as compared with Comparative Examples 1 and 2 outside the scope of the present invention. . Furthermore, although it is thought that it is the stabilization effect by an amino group, it was unexpected that the reproducibility of image formation sensitivity was improved as compared with Comparative Examples 3 and 4. Further, the counter anion X ⁻ of the binder polymer may be a halogen type or a carboxylic acid type, but a halogeno complex ion, a halogen oxo acid anion, a borate anion, or a sulfonate anion is more preferable from the viewpoint of printing durability and stain resistance. I understand.

<Examples 18 to 52, Comparative Examples 5 to 8>
[Preparation of lithographic printing plate precursor type II series]
Except for changing the photosensitive layer coating solution 1 to the photosensitive layer coating solution 2 and the protective layer coating solution 1 to the protective layer coating solution 2, the same as the lithographic printing plate precursor type I series, including the undercoat coating solution formulation, is used. It was.

Photosensitive layer coating solution 2
-Specific binder polymer of the present invention (Exemplary compounds described in Table 2)
0.52g
-Compound (M-1) having an ethylenically unsaturated bond 0.50 g
・ Radical polymerization initiator (I-1) 0.08g
Sensitizing dye (D-1) 0.06g
・ Chain transfer agent (S-2) 0.07g
・ 0.40 g of ε-phthalocyanine pigment dispersion
[Pigment: 15 parts by mass, Allyl methacrylate / methacrylic acid (80/20) copolymer as a dispersant: 10 parts by mass, Cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 parts by mass / 20 parts as a solvent Parts / 40 parts by mass]
・ Thermal polymerization inhibitor 0.01g
(N-nitrosophenylhydroxylamine aluminum salt)
・ Fluorine-based surfactant (F-1) 0.001 g
・ Polyoxyethylene-polyoxypropylene condensate 0.04g
(Asahi Denka Kogyo Co., Ltd., Pluronic L44)
・ Tetraethylammonium chloride 0.01g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

Protective layer coating solution (2)
・ The following mica dispersion (1): 13.00 g
Polyvinyl alcohol (PVA-105 (manufactured by Kuraray Co., Ltd.), saponification degree 98 mol%, polymerization degree 500) 1.30 g
-Sodium 2-ethylhexyl sulfosuccinate 0.20 g
-Poly (vinyl pyrrolidone / vinyl acetate (1/1)) molecular weight 70,000
0.050g
・ Surfactant (Emalex 710; manufactured by Nippon Emulsion Co., Ltd.)
0.050g
・ Water 133.00g

Preparation of Mica Dispersion (1) To 368 g of water, 32 g of synthetic mica (“Somasif ME-100” manufactured by Co-op Chemical Co., Ltd., aspect ratio: 1000 or more) was added, and the average particle size (laser scattering method) was obtained using a homogenizer. ) Disperse to 0.5 μm to obtain a mica dispersion (1).

[Exposure, development and printing]
Each of the planographic printing plate precursor type II series was exposed, developed and printed in the same manner as in Example 1 except that the developer 1 was changed to the developer 2.

Developer 2
・ Water 100.00g
・ N-lauryldimethylbetaine 10.00g
(Takemoto Yushi Co., Ltd .; Pionein C157K)
・ Polystyrenesulfonic acid (Mw = 20,000) 1.00g
・ Primary ammonium phosphate 0.05g
・ Citric acid 0.05g
・ Ethylenediaminetetraacetate tetrasodium salt 0.05g
Furthermore, after adjusting so that the pH of a developing solution might be set to 5.0 using phosphoric acid, it was used as the developing solution 2.

[Evaluation]
The obtained lithographic printing plate was evaluated in the same manner as in Example 1. However, the standard (1.0) of developability, sensitivity, and printing durability was set to the comparative example 5. The results are shown in Table 2.

  As shown in Table 2, by using the binder polymer of the present invention, it is possible to improve developability, printing durability, and stain resistance as compared with Comparative Examples 5 and 6 outside the scope of the present invention. You can see that Further, it can be seen that the reproducibility of the image formation sensitivity is improved as compared with Comparative Examples 7 and 8.

<Examples 53 to 92, Comparative Examples 9 to 12>
[Preparation of lithographic printing plate type III series]
Except for changing the protective layer coating solution from the protective layer coating solution 2 to the protective layer coating solution 1, the same one as in the lithographic printing plate precursor II series was used, including the undercoat coating solution formulation.

[Exposure, development and printing]
Each of the lithographic printing plate precursor type III series precursors was exposed, developed and printed in the same manner as in Example 1 except that the developer 1 was changed to the developer 3.

Developer 3
・ Water 100.00g
・ Polyoxyethylene lauryl amino ether 10.00g
(Takemoto Yushi Co., Ltd .; Pionein D3110)
・ Polystyrenesulfonic acid 1.00g
・ Primary ammonium phosphate 0.05g
・ Citric acid 0.05g
・ Ethylenediaminetetraacetate tetrasodium salt 0.05g
Furthermore, after adjusting so that the pH of a developing solution might be set to 5.0 using phosphoric acid, it was used as the developing solution 3.

[Evaluation]
The obtained lithographic printing plate was evaluated in the same manner as in Example 1. However, the standard (1.0) of developability, sensitivity, and printing durability was set to the comparative example 9. The results are shown in Table 3.

  As shown in Table 3, by using the binder polymer of the present invention, it is possible to improve developability, printing durability, and stain resistance as compared with Comparative Examples 9 and 10 outside the scope of the present invention. You can see that Further, it can be seen that the reproducibility of the image formation sensitivity is improved as compared with Comparative Examples 11 and 12.

<Examples 93 to 108 and Comparative Examples 13 to 16>
[Preparation of lithographic printing plate type IV series]
Except for changing the photosensitive layer coating solution from the photosensitive layer coating solution 2 to the photosensitive layer coating solution 3 shown below, the same one as in the planographic printing plate precursor type II series including the undercoat coating solution formulation was used.

Photosensitive layer coating solution 3
-Specific binder polymer of the present invention (Exemplary compounds described in Table 4)
0.50g
・ 1.00 g of a compound having an ethylenically unsaturated bond
(Isocyanuric acid EO-modified triacrylate; NK ester M-315, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ Radical polymerization initiator (I-2) 0.08g
Sensitizing dye (D-2) 0.06g
・ 0.40 g of ε-phthalocyanine pigment dispersion
[Pigment: 15 parts by mass, Allyl methacrylate / methacrylic acid (80/20) copolymer as a dispersant: 10 parts by mass, Cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 parts by mass / 20 parts as a solvent Parts / 40 parts by mass]
・ Thermal polymerization inhibitor 0.01g
(N-nitrosophenylhydroxylamine aluminum salt)
・ Fluorine-based surfactant (F-1) 0.001 g
・ 1-methoxy-2-propanol 7.0g
・ Methyl ethyl ketone 7.0g

[Exposure, development and printing]
Each of the lithographic printing plate precursor type IV series was subjected to image exposure with a water-cooled 40 W infrared semiconductor laser-mounted Creo Trendsetter 3244VX under the conditions of an outer drum rotation speed of 210 rpm and a resolution of 2400 dpi with varying energy density. The obtained exposed lithographic printing plate precursor was developed and printed in the same manner as in Example 1 except that the developer 1 was changed to the developer 2.

[Evaluation]
The obtained lithographic printing plate was evaluated in the same manner as in Example 1. However, the standard (1.0) of developability, sensitivity, and printing durability was set to the reference value of Comparative Example 13, and the exposure was performed with the infrared laser (conditions for evaluating reproducibility of printing durability and image formation density). : Output 9 W, outer drum rotation speed 210 rpm, resolution 2400 dpi).
The results are shown in Table 4.

  As shown in Table 4, by using the binder polymer of the present invention, it is possible to improve developability, printing durability, and stain resistance as compared with Comparative Examples 13 and 14 outside the scope of the present invention. You can see that Further, it can be seen that the reproducibility of the image formation sensitivity is improved as compared with Comparative Examples 15 and 16.

Structure of automatic processor

Explanation of symbols

1: rotating brush roll 2: receiving roll 3: transport roll 4: transport guide plate 5: spray pipe 6: pipeline 7: filter 8: plate supply table 9: plate discharge table 10: developer tank 11: circulation pump 12: plate

Claims (9)

A photosensitive composition having a photosensitive layer containing the following (A) to (C) on a support.
(A) Binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain (B) Compound having ethylenically unsaturated bond (C) Polymerization initiator (A) In the binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain, groups having a positively charged nitrogen atom are represented by the following general formulas (1) to (1): The photosensitive composition according to claim 1, which has a group represented by any one of 4).

In the formula, R _{1 to} R ₇ each represent a monovalent substituent, and X ⁻ represents an anion. Any _{two of} R ₁ and R ₂ and R _{4 to} R ₆ may be bonded to each other to form a ring. In the general formulas (2) and (4), -N ⁺ = C- constitutes a cyclic structure.   (A) The binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain is a (meth) acrylic resin or a urethane resin. 2. The photosensitive composition according to 2.   (A) The photosensitivity according to claim 1 or 2, wherein the binder polymer having at least one positively charged nitrogen atom and at least one amino group in the main chain and / or side chain is a urethane resin. Composition. In the general formulas (1) to (4), at least one of R ₁ and R ₂ , R ₃ , at least one of R _{4 to} R ₆ , and R ₇ have a hydrogen atom group, The photosensitive composition as described in any one of Claims 1-4.   The binder polymer having at least one positively charged nitrogen atom and at least one amino group is made by neutralizing a part of the amino group of the polymer having an amino group with an acid, The photosensitive composition as described in any one of Claims 1-5.   The photosensitive composition according to claim 1, wherein the photosensitive layer further contains (D) a sensitizing dye. After image-exposing the photosensitive composition as described in any one of Claims 1-7 with a laser, pH
A method for forming an image, comprising: removing an unexposed photosensitive layer in the presence of a developing solution of 2 to 6.5.   A lithographic printing plate precursor comprising the photosensitive composition according to any one of claims 1 to 7.