WO2010004780A1 - Photosensitive lithographic plate material - Google Patents

Abstract

The present invention provides a photosensitive lithographic plate material with excellent initial print adaptivity and printing resistance, which is used in a plate making method for manufacturing lithographic plates by removing unexposed parts with a developer containing a water-soluble resin and a surfactant and having a pH in the range of 3.0-9.0, after exposing and recording image information. Said photosensitive lithographic plate material is characterized by the fact that a photosensitive layer containing a sensitizer, a radical generating agent, a polymerizable monomer, and a binder is present on a support having a hydrophilic surface, and the total concentration of methacrylol groups and acryloyl groups contained in the molecules of the polymerizable monomer is from 2.5 to 3.5 mmol/g with respect to the total mass of the photosensitive layer.

Description

Photosensitive lithographic printing plate material

The present invention relates to a photosensitive lithographic printing plate material, and more specifically, a photosensitive lithographic printing plate material capable of producing a lithographic printing plate by removing an unexposed portion with a developer having a pH in the range of 3.0 to 9.0. About.

Generally, 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, conventionally, a photosensitive lithographic printing plate material in which an oleophilic photosensitive layer (image recording layer) is provided on a hydrophilic support has been widely used. Usually, after exposing a photosensitive lithographic printing plate material through an original image such as a lithographic film, the image recording layer to be an image portion is left, and the other unnecessary image recording layer is formed with an alkaline developer or organic The lithographic printing plate is obtained by carrying out plate making by a method in which the surface of the hydrophilic support is exposed by dissolving with a solvent to form a non-image portion.

In the conventional plate making process of a photosensitive lithographic printing plate material, it is necessary to dissolve and remove an unnecessary image recording layer with a developer after exposure, but it is easy to perform such additional wet processing. Is 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 on high-convergence radiation such as laser light, and the photosensitive lithographic printing plate material is scanned and exposed with the light, directly without using a lithographic film. Computer-to-plate technology for producing printing plates has attracted attention. Therefore, obtaining a photosensitive lithographic printing plate material adapted to such a technique is one of the important technical problems.

Due to the above-mentioned background, it is now increasingly desired to make the platemaking work easier and adapt to both aspects of digitization than ever before.

In contrast, a photosensitive lithographic printing plate material having a photosensitive layer comprising a sensitizer, a radical generator, a polymerizable monomer, and a binder on a support having a hydrophilic surface is mixed with a developer having a pH of 2 to 10. A method of making a lithographic printing plate in the presence is disclosed (for example, see Patent Document 1). Also, a photosensitive lithographic printing plate material having a photopolymerizable layer on a support having a hydrophilic surface or provided with a hydrophilic layer is made into a lithographic printing plate with a rubber solution having a pH of 3 to 9. A method is disclosed (for example, see Patent Document 2). However, in these inventions, since the activity of the developer is low in the low pH treatment, it is difficult to achieve both good developability and printing durability, and there is a problem in loss paper and printing durability during printing.
JP 2007-058170 A Special table 2007-538279 gazette

An object of the present invention is to provide a photosensitive lithographic printing plate material which is excellent in initial printing suitability and excellent in printing durability with little paper loss during printing even when a low pH developer is used. is there.

The above object of the present invention can be achieved by the following configuration.

1. After exposing and recording image information, a plate making method for producing a lithographic printing plate by removing an unexposed portion with a developer containing a water-soluble resin and a surfactant and having a pH of 3.0 to 9.0. In the photosensitive lithographic printing plate material used, the photosensitive lithographic printing plate material has a photosensitive layer containing a sensitizer, a radical generator, a polymerizable monomer and a binder on a support having a hydrophilic surface. And the total of methacryloyl groups and acryloyl groups contained in the molecule of the polymerizable monomer is a concentration of 2.5 to 3.5 mmol / g based on the total mass of the photosensitive layer. Plate material.

2. After exposing and recording image information with a laser light source having an emission wavelength in the range of 350 nm to 450 nm, it is not yet developed with a developer containing a water-soluble resin and a surfactant and having a pH in the range of 3.0 to 9.0. In a photosensitive lithographic printing plate material used in a plate making method for producing a lithographic printing plate by removing an exposed portion, the photosensitive lithographic printing plate material has a sensitizer and a radical generator on a support having a hydrophilic surface. A photosensitive layer containing an agent, a polymerizable monomer, and a binder, and the total of methacryloyl and acryloyl groups contained in the polymerizable monomer molecule is 2.5 to 3.5 mmol based on the total mass of the photosensitive layer. A photosensitive lithographic printing plate material having a concentration of / g.

3. 3. The photosensitive lithographic printing plate material as described in 1 or 2 above, wherein the total of the methacryloyl group and the acryloyl group is from 2.9 to 3.5 mmol / g based on the total mass of the photosensitive layer.

4. 4. The photosensitive lithographic printing plate material as described in any one of 1 to 3 above, wherein the content of the polymerizable monomer in the photosensitive layer is 40 to 60% by mass.

5. 5. The photosensitive lithographic printing plate material as described in any one of 1 to 4 above, wherein the radical generator is a hexaarylbiimidazole compound.

6. 6. The photosensitive lithographic printing plate material as described in any one of 1 to 5 above, further comprising an oxygen blocking layer having polyvinyl alcohol as a component on the photosensitive layer.

According to the present invention, it is possible to provide a photosensitive lithographic printing plate material which has little initial loss in printing even when a low pH developer is used and which has excellent initial printing suitability and excellent printing durability. Although the mechanism by which the above effect is produced by the present invention is not clear, by setting the concentration of the methacryloyl group and acryloyl group in a specific range in the photosensitive layer, the photopolymerization rate is high in the exposed area, and in the unexposed area. It is presumed that a soft resin layer is formed.

The present invention will be described in more detail.

(Radical generator)
The radical generator according to the present invention is capable of initiating polymerization of a polymerizable monomer that can be polymerized by image exposure, and the photosensitive layer is generally known as a photopolymerization initiator as a radical generator. Various compounds can be used.

Examples include biimidazole compounds, titanocene compounds, monoalkyltriaryls, borate compounds, iron arene complex compounds, polyhalogen compounds, and other Chemistry & Technology of UV & EB Formation for Coating, Inks & Paints Volumes of Three. And photopolymerization initiators described in (by JV Crivero, K. Dieticker).

Among them, a preferred radical generator is a biimidazole compound. Biimidazole compounds are biimidazole and biimidazole derivatives, and examples thereof include compounds described in JP-A No. 2003-295426.

In the present invention, a hexaarylbiimidazole compound (triaryl-imidazole dimer, abbreviated as HABI) can be preferably used as the biimidazole compound.

The production process of HABI is described in DE 1,470,154 and their use in photopolymerizable compositions is described in EP 24,629, EP 107,792, US 4,410,621, EP 215,453 and DE 3,211. 312.

Preferred biimidazole compounds include, for example, 2,4,5,2 ′, 4 ′, 5′-hexaphenylbiimidazole, 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5 ′. -Tetraphenylbiimidazole, 2,2'-bis (2-bromophenyl) -4,5,4 ', 5'-tetraphenylbiimidazole, 2,2'-bis (2,4-dichlorophenyl) -4, 5,4 ', 5'-tetraphenylbiimidazole, 2,2'-bis (2-chlorophenyl) -4,5,4', 5'-tetrakis (3-methoxyphenyl) biimidazole, 2,2'- Bis (2-chlorophenyl) -4,5,4 ', 5'-tetrakis (3,4,5-trimethoxyphenyl) -biimidazole, 2,5,2', 5'-tetrakis (2-chlorophenyl)- 4, '-Bis (3,4-dimethoxyphenyl) biimidazole, 2,2'-bis (2,6-dichlorophenyl) -4,5,4', 5'-tetraphenylbiimidazole, 2,2'-bis ( 2-nitrophenyl) -4,5,4 ', 5'-tetraphenylbiimidazole, 2,2'-di-o-tolyl-4,5,4', 5'-tetraphenylbiimidazole, 2,2 '-Bis (2-ethoxyphenyl) -4,5,4', 5'-tetraphenylbiimidazole and 2,2'-bis (2,6-difluorophenyl) -4,5,4 ', 5'- Tetraphenylbiimidazole is mentioned. These biimidazole compounds can be obtained as commercial products.

The content of the biimidazole compound is preferably 0.05% by mass to 20.0% by mass, and particularly preferably 1.0% by mass to 15.0% by mass with respect to the photosensitive layer.

As other radical generators, titanocene compounds, monoalkyltriaryl borate compounds, iron arene complex compounds, polyhalogen compounds and the like may be used.

Examples of the titanocene compound include compounds described in JP-A-63-41483 and JP-A-2-291. More preferable specific examples include bis (cyclopentadienyl) -Ti-di-dioxide. Chloride, bis (cyclopentadienyl) -Ti-bis-phenyl, bis (cyclopentadienyl) -Ti-bis-2,3,4,5,6-pentafluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,3,5,6-tetrafluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,4,6-trifluorophenyl, bis (cyclopentadienyl) -Ti-bis -2,6-difluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,4-difluorophenyl, bis (methylcyclopentadienyl) Ti-bis-2,3,4,5,6-pentafluorophenyl, bis (methylcyclopentadienyl) -Ti-bis-2,3,5,6-tetrafluorophenyl, bis (methylcyclopentadienyl) ) -Ti-bis-2,6-difluorophenyl (IRUGACURE 727L: manufactured by Ciba Japan Ltd.), bis (cyclopentadienyl) -bis (2,6-difluoro-3- (py-1-yl) Phenyl) titanium (IRUGACURE784: Ciba Japan KK), bis (cyclopentadienyl) -bis (2,4,6-trifluoro-3- (pyridin-1-yl) phenyl) titanium bis (cyclo Pentadienyl) -bis (2,4,6-trifluoro-3- (2-5-dimethylpy-1-yl) phenyl) titanium and the like That.

Examples of the monoalkyl triaryl borate compound include compounds described in JP-A Nos. 62-150242 and 62-14304. More preferable specific examples include tetra-n-butylammonium. n-butyl-trinaphthalen-1-yl-borate, tetra-n-butylammonium / n-butyl-triphenyl-borate, tetra-n-butylammonium / n-butyl-tri- (4-tert-butylphenyl) -Borate, tetra-n-butylammonium.n-hexyl-tri- (3-chloro-4-methylphenyl) -borate, tetra-n-butylammonium.n-hexyl-tri- (3-fluorophenyl) -borate Etc.

Examples of the iron arene complex compound include compounds described in JP-A-59-219307, and more preferable specific examples include η-benzene- (η-cyclopentadienyl) iron hexafluorophosphate, η -Cumene- (η-cyclopentadienyl) iron hexafluorophosphate, η-fluorene- (η-cyclopentadienyl) iron hexafluorophosphate, η-naphthalene- (η-cyclopentadienyl) iron hexafluorophosphate, and η-xylene- (η-cyclopentadienyl) iron hexafluorophosphate, η-benzene- (η-cyclopentadienyl) iron tetrafluoroborate, and the like.

As the polyhalogen compound, a compound having a trihalogenmethyl group, a dihalogenmethyl group or a dihalomethylene group is preferably used. In particular, the halogen compound represented by the following general formula (4) and the above group are represented by 1, 3, 5 A triazine compound having a triazine ring and an oxadiazole compound having the above group in an oxadiazole ring are preferably used.

Formula (4) R ₁ —C (Y) ₂ — (C═O) —R ₂
In the formula, R ₁ represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an acyl group, an alkylsulfonyl group, an arylsulfonyl group, an iminosulfonyl group, or a cyano group. R ₂ represents a monovalent substituent. R ₁ and R ₂ may be bonded to form a ring. Y represents a halogen atom.

The monovalent substituent represented by R ₂ is substituted, unsubstituted alkyl group, substituted, unsubstituted aryl group, substituted, unsubstituted heterocyclic group, substituted, unsubstituted alkoxy group, substituted, unsubstituted Represents an aryloxy group, a substituted, an unsubstituted amino group or a hydroxyl group.

Among these, polyhalogen compounds represented by the following general formula (5) are particularly preferably used.

Formula (5) C (Y) ₃ — (C═O) —XR ₃
Wherein R ₃ represents a monovalent substituent. X represents —O— or —NR ₄ —, and R ₄ represents a hydrogen atom or an alkyl group. When X is —NR ₄ —, R ₃ and R ₄ may be bonded to each other to form a ring. Y represents a halogen atom.

The monovalent substituent represented by R ₃ represents a substituted, unsubstituted alkyl group, a substituted, unsubstituted aryl group, or a substituted, unsubstituted heterocyclic group.

Among these, as the polyhalogen compound, those having a polyhalogen acetylamide group are particularly preferable.

Other optional radical generators can be used in combination. For example, J. et al. Carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo, diazo compounds, halogen compounds, and photoreductive dyes as described in Chapter 5 of “Light Sensitive Systems” by J. Kosar Etc. More specific compounds are disclosed in British Patent 1,459,563.

That is, the following can be used as the radical generator that can be used in combination.

Benzoin derivatives such as benzoin methyl ether, benzoin-i-propyl ether, α, α-dimethoxy-α-phenylacetophenone; benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethyl) Benzophenone derivatives such as amino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-i-propylthioxanthone; anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone; N-methylacridone, N-butylacridone and the like Acridone derivatives: α, α-diethoxyacetophenone, benzyl, fluorenone, xanthone, uranyl compounds, JP-B-59-1281, JP-A-69-1621 and JP-A-60-60104 Triazine derivatives; organic peroxides described in JP-A-59-1504 and JP-A-61-243807; JP-B-43-23684, JP-A-44-6413, JP-A-44-6413, JP-A-47-1604 and the United States Diazonium compounds described in Japanese Patent No. 3,567,453; organic azide compounds described in US Pat. Nos. 2,848,328, 2,852,379 and 2,940,853; Japanese Patent Publication No. 36-22062, O-quinonediazides described in JP-A-37-13109, JP-A-38-18015 and JP-A-45-9610; JP-B-55-39162, JP-A-59-14023 and “Macromolecules”, Vol. 10, Various onium compounds described on page 1307 (1977); azo compounds described in JP-A-59-142205 Compound: described in JP-A-1-54440, European Patents 109,851 and 126,712, and “Journal of Imaging Science (J. Imag. Sci.)”, Vol. 30, 174 (1986) (Oxo) sulfonium organoboron complexes described in JP-A-5-213861 and JP-A-5-255347; "Coordination Chemistry Review" Vol. 84, pp. 85-277 (1988) And transition metal complexes containing a transition metal such as ruthenium described in JP-A-2-182701; 2,4,5-triarylimidazole dimer described in JP-A-3-209477; carbon tetrabromide, JP Organic halogens described in Sho 59-107344 Compounds, etc..

The content of the polymerization initiator (total amount of the polymerization initiator) is preferably 0.1% by mass to 20% by mass and particularly preferably 0.5% by mass to 15% by mass with respect to the polymerizable ethylenically unsaturated bond-containing compound. preferable.

(Polymerizable monomer)
The polymerizable monomer of the present invention is a compound having an ethylenic double bond that can be polymerized by a radical generator in the image-exposed photosensitive layer, and has at least a methacryloyl group or an acryloyl group.

The polymerizable monomer that can be used in the present invention is an acrylic acid ester compound, a methacrylic acid ester compound or the like, generally known as a photopolymerizable monomer / oligomer, Polyfunctional monomers having a plurality of addition-polymerizable ethylenic double bonds or polyfunctional oligomers generally used in UV curable resins can be used alone or in combination.

These compounds are not limited, but preferred examples include 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, Monofunctional acrylic acid esters such as tetrahydrofurfuryloxyhexanolide acrylate, acrylate of ε-caprolactone adduct of 1,3-dioxane alcohol, 1,3-dioxolane acrylate, or these acrylates with methacrylate, itaconate, crotonate, Methacrylic acid instead of maleate, itaconic acid, crotonic acid, maleic acid esters such as ethylene glycol Chryrate, triethylene glycol diacrylate, pentaerythritol diacrylate, hydroquinone diacrylate, resorcinol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, diacrylate of neopentyl glycol hydroxypivalate, neo Diacrylate of pentyl glycol adipate, diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate, 2- (2-hydroxy-1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-1,3 -Ε-caprolactone of dioxane diacrylate, tricyclodecane dimethylol acrylate, tricyclodecane dimethylol acrylate Additives, bifunctional acrylates such as diacrylate of diglycidyl ether of 1,6-hexanediol, or methacrylic acid, itaconic acid, crotonic acid, maleate in which these acrylates are replaced with methacrylate, itaconate, crotonate, maleate Acid esters such as trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, Ε-caprolactone adduct of dipentaerythritol hexaacrylate, pyrogallol tria Relate, polyfunctional acrylic acid ester acid such as propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, hydroxypivalylaldehyde-modified dimethylolpropane triacrylate, or these acrylates with methacrylate, itaconate, crotonate, Examples thereof include methacrylic acid, itaconic acid, crotonic acid, and maleic acid ester instead of maleate.

Also, prepolymers can be used in the same manner as described above. Examples of the prepolymer include compounds as described below, and a prepolymer obtained by introducing acrylic acid or methacrylic acid into an oligomer having an appropriate molecular weight and imparting photopolymerizability can be preferably used. These prepolymers may be used singly or in combination of two or more, and may be used by mixing with the above-mentioned monomers and / or oligomers.

Examples of prepolymers include adipic acid, trimellitic acid, maleic acid, phthalic acid, terephthalic acid, hymic acid, malonic acid, succinic acid, glutaric acid, itaconic acid, pyromellitic acid, fumaric acid, glutaric acid, pimelic acid, Polybasic acids such as sebacic acid, dodecanoic acid, tetrahydrophthalic acid, and ethylene glycol, propylene glycol, diethylene glycol, propylene oxide, 1,4-butanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, trimethylol Polyester in which (meth) acrylic acid is introduced into polyester obtained by the combination of polyhydric alcohols such as propane, pentaerythritol, sorbitol, 1,6-hexanediol, 1,2,6-hexanetriol Acrylates such as bisphenol A, epichlorohydrin, (meth) acrylic acid, and epoxy acrylates in which (meth) acrylic acid is introduced into an epoxy resin such as phenol novolac, epichlorohydrin, (meth) acrylic acid, such as ethylene glycol adipine Acid / tolylene diisocyanate / 2-hydroxyethyl acrylate, polyethylene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate, hydroxyethyl phthalyl methacrylate / xylene diisocyanate, 1,2-polybutadiene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate , Trimethylolpropane, propylene glycol, tolylene diisocyanate, 2-hydroxyethyl acrylate As described above, urethane acrylates in which (meth) acrylic acid is introduced into a urethane resin, for example, silicone resin acrylates such as polysiloxane acrylate, polysiloxane diisocyanate, 2-hydroxyethyl acrylate, and other oil-modified alkyd resins (meth) Examples thereof include prepolymers such as alkyd-modified acrylates and spirane resin acrylates into which acryloyl groups are introduced.

The photosensitive layer according to the present invention includes a phosphazene monomer, triethylene glycol, isocyanuric acid EO (ethylene oxide) modified diacrylate, isocyanuric acid EO modified triacrylate, dimethylol tricyclodecane diacrylate, trimethylolpropane benzoic acid benzoic acid. Addition-polymerizable oligomers and prepolymers having monomers such as esters, alkylene glycol type acrylic acid-modified, urethane-modified acrylates, and structural units formed from the monomers can be contained.

Furthermore, examples of the ethylenic monomer that can be used in combination with the present invention include phosphate ester compounds containing at least one (meth) acryloyl group. The compound is not particularly limited as long as it is a compound in which at least part of the hydroxyl group of phosphoric acid is esterified and has a (meth) acryloyl group.

In addition, JP-A Nos. 58-212994, 61-6649, 62-46688, 62-48589, 62-173295, 62-187092, 63- 67189, JP-A-1-244891, and the like. Furthermore, “11290 Chemical Products”, Chemical Industry Daily, p. 286-p. 294, “UV / EB Curing Handbook (raw material)”, Kobunshi Publishing Co., p. The compounds described in 11 to 65 can also be suitably used in the present invention. Of these, compounds having two or more acrylic groups or methacryl groups in the molecule are preferred in the present invention, and those having a molecular weight of 10,000 or less, more preferably 5,000 or less are preferred.

In addition, acrylates or alkyl acrylates described in JP-A-1-105238 and JP-A-2-127404 can be used.

As the polymerizable monomer, reaction products of the following compounds (C1) to (C3) are particularly preferably used.
(C1) a compound containing at least one ethylenic double bond and one hydroxyl group in the molecule (C2) a diisocyanate compound (C3) a diol compound having a tertiary amine structure in the molecule, or an intramolecular Compounds having a secondary amine structure and one hydroxyl group each as C1 include, for example, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, 2-hydroxypropyl methacrylate.

C2 is a compound having two isocyanate groups. (C2) Diisocyanate compounds include 1,3-bis (1-isocyanato-1-methylethyl) benzene (2 mol), 1,3-diisocyanate. Examples thereof include natobenzene, 1,3-diisocyanate-4-methylbenzene, 1,3-di (isocyanatomethyl) benzene and the like. Examples of C3 include Nn-butyldiethanolamine, N-methyldiethanolamine, 1,4-di (2-dihydroxyethyl), N-ethyldiethanolamine, and the like.

The content of the polymerizable monomer according to the present invention in the photosensitive layer is preferably 0.5% by mass to 15.0% by mass and particularly preferably 1.0% by mass to 8.0% by mass with respect to the photosensitive layer.

The use amount of the polymerizable monomer within the scope of the present invention is the total amount of the methacryloyl group and the acryloyl group according to the present invention, and the total solid content used in the photosensitive layer and the methacryloyl group contained in the polymerizable monomer used. And the total amount of acryloyl groups can be calculated.

(binder)
The binder according to the present invention is capable of supporting the components contained in the photosensitive layer on a support, and examples of the binder include an acrylic polymer, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, a polyester resin, an epoxy resin, Phenol resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl formal resin, shellac, and other natural resins can be used. Two or more of these may be used in combination.

Preferably, a vinyl copolymer obtained by copolymerization of an acrylic monomer is preferable. Furthermore, the copolymer composition of the binder is preferably a copolymer of (a) polyalkylene glycol methacrylic acid ester or acrylic acid ester, (b) methacrylic acid alkyl ester, or acrylic acid alkyl ester.

(A) Polyalkylene glycol methacrylic acid ester or acrylic acid ester includes polyethylene glycol monomethacrylic acid ester, polyethylene glycol monoacrylic acid ester, polyethylene glycol monomethacrylic acid ester monoalkyl ether, polyethylene glycol Examples thereof include monoacrylic acid ester monoalkyl ether, polypropylene glycol monomethacrylic acid ester, polypropylene glycol monoacrylic acid ester, polypropylene glycol monomethacrylic acid ester monoalkyl ether, and polypropylene glycol monoacrylic acid ester monoalkyl ether. These are commercially available from manufacturers such as Shin-Nakamura Chemical Co., Ltd.

(B) Specific examples of alkyl methacrylates and alkyl esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, Nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, acrylic acid In addition to unsubstituted alkyl esters such as nonyl, decyl acrylate, undecyl acrylate and dodecyl acrylate, cyclic alkyl ethers such as cyclohexyl methacrylate and cyclohexyl acrylate Tellurium, benzyl methacrylate, 2-chloroethyl methacrylate, N, N-dimethylaminoethyl methacrylate, glycidyl methacrylate, benzyl acrylate, 2-chloroethyl acrylate, N, N-dimethylaminoethyl acrylate, glycidyl acrylate, etc. Also included are substituted alkyl esters.

Furthermore, for the binder, the monomers described in the following (1) to (15) can be used as copolymerization monomers.

1) Monomers having an aromatic hydroxyl group, such as o- (or p-, m-) hydroxystyrene, o- (or p-, m-) hydroxyphenyl acrylate and the like.

2) Monomers having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, N-methylol methacrylamide, 4-hydroxybutyl methacrylate, 5-hydroxypentyl acrylate, 5-hydroxypentyl methacrylate 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, hydroxyethyl vinyl ether and the like.

3) A monomer having an aminosulfonyl group, such as m- (or p-) aminosulfonylphenyl methacrylate, m- (or p-) aminosulfonylphenyl acrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p -Aminosulfonylphenyl) acrylamide and the like.

4) Monomers having a sulfonamide group, such as N- (p-toluenesulfonyl) acrylamide, N- (p-toluenesulfonyl) methacrylamide and the like.

5) Acrylamide or methacrylamide such as acrylamide, methacrylamide, N-ethylacrylamide, N-hexylacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N- (4-nitrophenyl) acrylamide, N-ethyl-N- Phenylacrylamide, N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide and the like.

6) Monomers containing alkyl fluoride groups such as trifluoroethyl acrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, hexafluoropropyl methacrylate, octafluoropentyl acrylate, octafluoropentyl methacrylate, heptadecafluorodecyl methacrylate, N- Butyl-N- (2-acryloxyethyl) heptadecafluorooctylsulfonamide and the like.

7) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether and the like.

8) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate and the like.

9) Styrenes such as styrene, methyl styrene, chloromethyl styrene and the like.

10) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone and the like.

11) Olefins such as ethylene, propylene, i-butylene, butadiene, isoprene and the like.

12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine and the like.

13) Monomers having a cyano group, such as acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, o- (or m-, p-) cyanostyrene.

14) Monomers having amino groups such as N, N-diethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, polybutadiene urethane acrylate, N, N-dimethylaminopropyl acrylamide, N, N-dimethylacrylamide, acryloylmorpholine, Ni-propylacrylamide, N, N-diethylacrylamide and the like.

15) Specific examples of the carboxyl group-containing monomer include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride and the like. In addition, carboxylic acids such as phthalic acid and 2-hydroxymethacrylate half ester are also preferred.

Further, other monomers that can be copolymerized with these monomers may be copolymerized.

Furthermore, the binder is preferably a vinyl polymer having a polymerizable double bond. For example, an unsaturated bond-containing vinyl copolymer obtained by addition-reacting a compound having a (meth) acryloyl group and an epoxy group in the molecule to a carboxyl group present in the molecule of the vinyl copolymer. Is also preferred as a binder.

Specific examples of the compound containing both an unsaturated bond and an epoxy group in the molecule include glycidyl acrylate, glycidyl methacrylate, and an epoxy group-containing unsaturated compound described in JP-A No. 11-271969. An unsaturated bond-containing vinyl copolymer obtained by addition reaction of a compound having a (meth) acryloyl group and an isocyanate group in the molecule to a hydroxyl group present in the molecule of the vinyl polymer is also a binder. As preferred. Compounds having both an unsaturated bond and an isocyanate group in the molecule include vinyl isocyanate, (meth) acrylic isocyanate, 2- (meth) acryloyloxyethyl isocyanate, m- or p-isopropenyl-α, α'-dimethylbenzyl. Isocyanates are preferred, and examples include (meth) acrylic isocyanate and 2- (meth) acryloyloxyethyl isocyanate.

The vinyl polymer having a carboxyl group and a polymerizable double bond in the side chain is preferably 50 to 100% by mass and more preferably 100% by mass in the total polymer binder.

In the photosensitive lithographic printing plate material of the present invention, in order to solve the problems according to the present invention, among the above binders, in particular, a homopolymer or copolymer of N-vinylpyrrolidone is contained in the photosensitive layer. preferable.

When a copolymer of N-vinylpyrrolidone is used, the monomer to be copolymerized is not particularly limited, but vinyl acetate can be preferably used.

The binder content in the photosensitive layer is preferably in the range of 10 to 90% by weight, more preferably in the range of 15 to 70% by weight, and particularly preferably in the range of 20 to 50% by weight from the viewpoint of sensitivity.

(Sensitizer)
The photosensitive layer according to the present invention contains a sensitizer. Examples of the sensitizer include cyanine, merocyanine, porphyrin, spiro compound, ferrocene, fluorene, fulgide, imidazole, perylene, phenazine, phenothiazine, acridine, acridone, N-alkylacridone compound, azo compound, diphenylmethane, triphenylmethane , Triphenylamine, coumarin derivatives, quinacridone, indigo, styryl compounds, styryl stilbene compounds, triaryloxazole compounds, pyrylium compounds, pyromethene compounds, pyrazolotriazole compounds, benzothiazole compounds, barbituric acid derivatives, thiobarbituric acid derivatives , Keto alcohol borate complexes, and the like.

Particularly preferred are N-alkylacridone compounds, coumarin derivatives, styrylstilbene compounds, and triaryloxazole compounds.

Examples of the coumarin derivative include B-1 to B-22 coumarin derivatives of JP-A-8-129258, D-1 to D-32 coumarin derivatives of JP-A-2003-21901, and JP-A-2002. No. 1-363206 of coumarin derivatives, JP-A No. 2002-363207 No. 1 to 40 coumarin derivatives, JP-A No. 2002-363208 No. 1 to 34 coumarin derivatives, JP-A No. 2002-363209 Examples thereof include 1 to 56 coumarin derivatives and can be preferably used.

Examples of the styrylstilbene compound include compounds described in WO2005029187 (A1).

Examples of the triaryloxazole compound include compounds described in WO2004074930 (A1).

Other sensitizers that can be preferably used include, for example, JP-A No. 2000-98605, JP-A No. 2000-147663, JP-A No. 2000-206690, JP-A No. 2000-258910, JP-A No. 2000-309724, And spectral sensitizers described in JP-A No. 2001-042524 and JP-A No. 2002-202598.

In the present invention, a spectral sensitizer having an absorption maximum wavelength of 370 to 420 nm is preferably used.

(Mercapto compound)
The photosensitive layer according to the present invention preferably contains a mercapto compound in terms of increasing sensitivity and preventing sensitivity fluctuations.

The mercapto compound is a compound having a mercapto group. For example, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercapto-4-methyl-5-acetylthiazole, 2-mercapto-4 -Methylthiazole, 1-methyl-2-mercaptoimidazole, 2-mercapto-4,5-dimethylthiazole, 2-mercapto-5-acetylthiazole, 1-methyl-2-mercaptobenzimidazole, 1-methyl-2-mercapto Examples include -4-methyl-5-acetylimidazole, 2-mercaptooxazole, 2-mercaptobenzoxazole, and 2-mercapto-2-imidazoline.

The content of the mercapto compound is preferably from 0.01 to 5% by mass, particularly preferably from 0.1 to 1% by mass, based on the photosensitive layer.

(Various additives)
In the photosensitive layer according to the present invention, in addition to the above-described components, in order to prevent unnecessary polymerization of the ethylenic double bond monomer that can be polymerized during the production or storage of the photosensitive lithographic printing plate material, It is desirable to add a polymerization inhibitor.

Suitable polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol) 2,2'-methylenebis (4-methyl-6-t-butylphenol), N-nitrosophenylhydroxylamine cerium salt, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5 -Methylbenzyl) -4-methylphenyl acrylate and the like.

The addition amount of the polymerization inhibitor is preferably about 0.01% to about 5% with respect to the mass of the total solid content of the photosensitive layer. If necessary, higher fatty acid derivatives such as behenic acid and behenic acid amide may be added to prevent polymerization inhibition due to oxygen, or it may be unevenly distributed on the surface of the photosensitive layer during the drying process after coating. Good. The amount of higher fatty acid derivative added is preferably about 0.5% to about 10% of the total composition.

In addition, a colorant can also be used, and as the colorant, conventionally known ones can be suitably used, including commercially available ones. Examples include those described in the revised new edition “Pigment Handbook”, edited by Japan Pigment Technology Association (Seikodo Shinkosha), Color Index Handbook, and the like.

Examples of pigments include black pigments, yellow pigments, red pigments, brown pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, and metal powder pigments. Specifically, inorganic pigments (titanium dioxide, carbon black, graphite, zinc oxide, Prussian blue, cadmium sulfide, iron oxide, and lead, zinc, barium and calcium chromates) and organic pigments (azo-based, thioindigo) , Anthraquinone, anthanthrone, and triphendioxazine pigments, vat dye pigments, phthalocyanine pigments and derivatives thereof, quinacridone pigments, and the like.

Among these, it is preferable to select and use a pigment having substantially no absorption in the absorption wavelength region of the spectral sensitizing dye corresponding to the exposure laser to be used. In this case, an integrating sphere at the laser wavelength to be used is used. It is preferable that the reflection absorption of the used pigment is 0.05 or less. The addition amount of the pigment is preferably 0.1 to 10% by mass, more preferably 0.2 to 5% by mass, based on the solid content of the composition.

From the viewpoints of pigment absorption in the above-mentioned photosensitive wavelength region and visible image properties after development, it is preferable to use a purple pigment or a blue pigment. Such as, for example, cobalt blue, cerulean blue, alkali blue lake, phonatone blue 6G, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, first sky blue, indanthrene blue, indico, dioxane violet, Examples include isoviolanthrone violet, indanthrone blue, and indanthrone BC. Among these, phthalocyanine blue and dioxane violet are more preferable.

Further, the photosensitive layer can contain a surfactant as a coating property improving agent as long as the performance of the present invention is not impaired. Of these, fluorine-based surfactants are preferred.

In order to improve the physical properties of the cured film, additives such as inorganic fillers and plasticizers such as dioctyl phthalate, dimethyl phthalate and tricresyl phosphate may be added. These addition amounts are preferably 10% or less of the total solid content.

Examples of the solvent used in preparing the photosensitive layer coating solution for the photosensitive layer according to the present invention include, for example, alcohol: polyhydric alcohol derivatives such as sec-butanol, isobutanol, n-hexanol, benzyl alcohol, Diethylene glycol, triethylene glycol, tetraethylene glycol, 1,5-pentanediol, ethers: propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, ketones, aldehydes: diacetone alcohol, cyclohexanone Preferred examples include methylcyclohexanone and esters: ethyl lactate, butyl lactate, diethyl oxalate, methyl benzoate and the like.

Although the photosensitive layer coating solution has been described above, the photosensitive layer according to the present invention is constituted by coating on a support using this.

In the photosensitive layer according to the present invention, the weight on the support is preferably from 0.1 g / m ² to 10 g / m ² , and particularly preferably from 0.5 g / m ² to 5 g / m ² .

(Protective layer (oxygen barrier layer))
A protective layer can be provided on the upper side of the photosensitive layer according to the present invention, if necessary.

The protective layer (oxygen barrier layer) preferably has high solubility in a developer (described below, generally an alkaline aqueous solution) described below, and specific examples include polyvinyl alcohol and polyvinyl pyrrolidone. Polyvinyl alcohol has an effect of suppressing permeation of oxygen, and polyvinyl pyrrolidone has an effect of ensuring adhesion with an adjacent photosensitive layer.

In addition to the above two polymers, polysaccharides, polyethylene glycol, gelatin, glue, casein, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl starch, gum arabic, sucrose octaacetate, ammonium alginate, sodium alginate as required Water-soluble polymers such as polyvinylamine, polyethylene oxide, polystyrene sulfonic acid, polyacrylic acid, and water-soluble polyamide can also be used in combination.

When a protective layer is provided on the photosensitive lithographic printing plate of the present invention, the peeling force between the photosensitive layer and the protective layer is preferably 35 mN / mm or more, more preferably 50 mN / mm or more, and even more preferably 75 mN / mm or more. is there. Preferred protective layer compositions include those described in JP-A-10-10742.

In the present invention, the peeling force is obtained by applying an adhesive tape having a predetermined width on the protective layer and having a sufficiently large adhesive force, and peeling it together with the protective layer at an angle of 90 degrees with respect to the plane of the photosensitive lithographic printing plate material. It can be determined by measuring the force.

The protective layer can further contain a surfactant, a matting agent and the like as required. The protective layer composition is dissolved in a suitable solvent, applied onto the photosensitive layer and dried to form a protective layer. The main component of the coating solvent is particularly preferably water or alcohols such as methanol, ethanol and i-propanol.

When a protective layer is provided, the thickness is preferably 0.1 to 5.0 μm, particularly preferably 0.5 to 3.0 μm.

(Support)
The support according to the present invention is a plate or film that can carry a photosensitive layer, and has a hydrophilic surface on the side where the photosensitive layer is provided.

Examples of the support according to the present invention include a metal plate such as aluminum, stainless steel, chromium and nickel, or a laminate obtained by laminating or vapor-depositing the above metal thin film on a plastic film such as a polyester film, a polyethylene film and a polypropylene film. .

Also, a surface of a polyester film, vinyl chloride film, nylon film or the like that has been subjected to a hydrophilic treatment can be used, but an aluminum support is preferably used.

In the case of an aluminum support, pure aluminum or an aluminum alloy is used.

Various aluminum alloys can be used as the support, and for example, alloys of metals such as silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, titanium, sodium, iron, and aluminum are used. . Further, the aluminum support having a roughened surface is used for water retention.

When using an aluminum support, it is preferable to perform a degreasing treatment to remove the rolling oil on the surface prior to roughening (graining treatment). As the degreasing treatment, a degreasing treatment using a solvent such as trichlene or thinner, an emulsion degreasing treatment using an emulsion such as kesilon or triethanol, or the like is used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, dirt and oxide film that cannot be removed only by the degreasing treatment can be removed. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, smut is generated on the surface of the support. In this case, the substrate is immersed in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid, or a mixed acid thereof and desmutted. It is preferable to perform the treatment. Examples of the roughening method include a mechanical method and a method of etching by electrolysis.

The mechanical surface roughening method used is not particularly limited, but a brush polishing method and a honing polishing method are preferable.

The electrochemical roughening method is not particularly limited, but a method of electrochemical roughening in an acidic electrolyte is preferable.

After roughening by the electrochemical roughening method, it is preferable to immerse in an aqueous solution of acid or alkali in order to remove aluminum scraps on the surface. Examples of the acid include sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like. Examples of the base include sodium hydroxide and potassium hydroxide. Among these, it is preferable to use an alkaline aqueous solution.

The amount of aluminum dissolved on the surface is preferably 0.5 to 5 g / m ² . In addition, it is preferable that after the immersion treatment with an alkaline aqueous solution, neutralization treatment is performed by immersion in an acid such as phosphoric acid, nitric acid, sulfuric acid, chromic acid or a mixed acid thereof.

The mechanical surface roughening method and the electrochemical surface roughening method may each be used alone for roughing, or the mechanical surface roughening method followed by the electrochemical surface roughening method. You may roughen.

Anodizing treatment can be performed after the roughening treatment. There is no restriction | limiting in particular in the method of the anodizing process which can be used in this invention, A well-known method can be used. By performing the anodizing treatment, an oxide film is formed on the support.

The anodized support may be subjected to a sealing treatment as necessary. These sealing treatments can be performed using known methods such as hot water treatment, boiling water treatment, water vapor treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment, and ammonium acetate treatment.

Furthermore, after performing these treatments, water-soluble resins such as polyvinylphosphonic acid, polymers and copolymers having sulfonic acid groups in the side chain, polyacrylic acid, water-soluble metal salts (for example, zinc borate) or Also suitable are those coated with a yellow dye, amine salt or the like. Further, a sol-gel treated substrate having a functional group capable of causing an addition reaction by a radical as disclosed in JP-A-5-304358 is also preferably used.

(Application)
The above photosensitive layer coating solution can be coated on a support by a conventionally known method and dried to prepare a photosensitive lithographic printing plate material.

Examples of coating methods for the coating liquid include an air doctor coater method, a blade coater method, a wire bar method, a knife coater method, a dip coater method, a reverse roll coater method, a gravure coater method, a cast coating method, a curtain coater method, and an extrusion coater method. Can be mentioned.

The drying temperature of the photosensitive layer is preferably in the range of 60 to 160 ° C., more preferably 80 to 140 ° C., and particularly preferably 90 to 120 ° C.

(Image exposure)
As a light source for exposing image information to the photosensitive lithographic printing plate material of the present invention, it is preferable to use a laser beam having an emission wavelength of 350 to 450 nm.

As a light source for exposing the photosensitive lithographic printing plate material of the present invention, for example, a He—Cd laser (441 nm), a combination of Cr: LiSAF and SHG crystal (430 nm) as a solid laser, and a semiconductor laser system as KNbO ₃ , Examples thereof include a ring resonator (430 nm), AlGaInN (350 nm to 450 nm), and an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 400 to 410 nm).

In the case of laser exposure, light can be narrowed down in the form of a beam and scanning exposure according to the image data is possible, which is suitable for direct writing without using a mask material.

Further, when a laser is used as a light source, it is easy to reduce the exposure area to a very small size, and high-resolution image formation is possible.

¡Laser scanning methods include cylindrical outer surface scanning, cylindrical inner surface scanning, and planar scanning. In the cylindrical outer surface scanning, laser exposure is performed while rotating a drum around which a recording material is wound, and the rotation of the drum is used as main scanning, and the movement of laser light is used as sub scanning. In cylindrical inner surface scanning, a recording material is fixed to the inner surface of the drum, a laser beam is irradiated from the inside, and a main scanning is performed in the circumferential direction by rotating a part or all of the optical system. Sub scanning is performed in the axial direction by linearly moving all of them in parallel with the drum axis. In plane scanning, a laser beam main scan is performed by combining a polygon mirror, a galvanometer mirror, and an fθ lens, and a sub-scan is performed by moving a recording medium. Cylindrical outer surface scanning and cylindrical inner surface scanning are easier to increase the accuracy of the optical system and are suitable for high-density recording.

In the present invention, image exposure is preferably performed with a plate surface energy (energy on the plate material) of 10 μJ / cm ² or more, and the upper limit is 300 μJ / cm ² . More preferably, it is 10 to 200 μJ / cm ² . For this energy measurement, for example, an optical power meter Q8230 manufactured by Advantest Corporation can be used.

(Post-exposure heat treatment)
The photosensitive lithographic printing plate material of the present invention is preferably subjected to heat treatment after exposure and before development to promote radical polymerization and increase the degree of polymerization of the image area. The heat treatment is preferably performed within 30 minutes after exposure. Further, it is preferably within 10 minutes, particularly preferably within 1 minute. The heat treatment is preferably performed with an infrared heater, a warm air heater, or the like, and heated so that the temperature of the plate surface is in the range of 70 to 130 degrees, preferably in the range of 80 to 120 degrees. The heating time is 5 seconds to 120 seconds, preferably 10 seconds to 60 seconds.

(Developer)
The exposed portion of the photosensitive layer subjected to image exposure is cured. This is developed with a developer containing a water-soluble resin and a surfactant and having a pH in the range of 3.0 to 9.0 to remove unexposed portions and form an image.

Examples of the water-soluble resin according to the present invention include starch derivatives such as gum arabic and dextrin, fiber derivatives (for example, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinylpyrrolidone, poly Examples include acrylamide and copolymers thereof, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, and styrene / maleic anhydride copolymer. The content of these water-soluble resins is suitably 0.1 to 50% by mass, more preferably 0.5 to 3.0% by mass in the composition.

In addition, examples of the surfactant according to the present invention include an anionic surfactant and a nonionic surfactant. For example, anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfones. Acid salts, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, polyoxyethylene aryl ether sulfonates, polyoxyethylene naphthyl ether sulfonates, N-methyl-N-oleyl taurine sodium salts N-alkylsulfosuccinic acid monoamide disodium salts, petroleum sulfonates, nitrated castor oil, sulfated beef tallow oil, sulfate esters of fatty acid alkyl esters, Rualkyl nitrates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphate esters, polyoxyethylene alkyl ethers Phosphoric acid ester salts, polyoxyethylene alkylphenyl ether phosphoric acid ester salts, partially saponified products of styrene-maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensates Etc. Among these, dialkyl sulfosuccinates, alkyl sulfate esters, and alkyl naphthalene sulfonates are particularly preferably used.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene aryl ethers, polyoxyethylene naphthyl ether, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxy Propylene alkyl ether, glycerin fatty acid partial ester, sorbitan fatty acid partial ester, pentaerythritol fatty acid partial ester, propylene glycol mono fatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid moiety Esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylenation Bran oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides, etc. It is done. Of these, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used. Fluorine-based and silicon-based anions and nonionic surfactants can also be used.

Examples of preferable surfactants include surfactants added to the lithographic printing plate surface protective agents described in JP-A Nos. 2004-167903, 2004-230650, and 2005-43393. .

These surfactants can be used in combination of two or more. For example, two or more different from each other can be used in combination. For example, a combination of two or more different anionic surfactants or a combination of an anionic surfactant and a nonionic surfactant is preferable. The amount of the surfactant used is not particularly limited, but is preferably 0.01 to 20% by mass of the post-treatment liquid.

The pH of the developer according to the present invention can be used in the range of 3.0 to 9.0. When used in the acidic range of pH 3 to 6, it is adjusted by adding a mineral acid, organic acid or inorganic salt to the aqueous solution. The addition amount is preferably 0.01 to 2% by mass. Examples of mineral acids include nitric acid, sulfuric acid, phosphoric acid, and metaphosphoric acid.

Examples of organic acids include citric acid, acetic acid, succinic acid, malonic acid, p-toluenesulfonic acid, tartaric acid, malic acid, lactic acid, levulinic acid, phytic acid, and organic phosphonic acid.

Further examples of inorganic salts include magnesium nitrate, primary sodium phosphate, secondary sodium phosphate, nickel sulfate, sodium hexamethanoate, sodium tripolyphosphate, and the like. You may use together at least 1 sort (s) or 2 or more types, such as a mineral acid, an organic acid, or an inorganic salt.

When used in the basic region pH 8 to 9, it can be adjusted to the pH by adding a water-soluble organic base or inorganic base. A water-soluble organic base is preferable, and examples include triethanolamine, diethanolamine, and ethanolamine.

Further, a preservative, an antifoaming agent, and the like can be added to the developer according to the present invention.

For example, as a preservative, phenol or a derivative thereof, o-phenylphenol, p-chlorometacresol, hydroxybenzoic acid alkyl ester, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benzoisothiazoline-3- ON, benztriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, derivatives of pyridine, quinoline, guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives and the like. A preferable addition amount is an amount that exerts a stable effect on bacteria, molds, yeasts, etc., and varies depending on the type of bacteria, molds, yeasts, but 0.01% with respect to the plate surface protective agent at the time of use. The range of ˜4% by mass is preferable, and two or more kinds of preservatives are preferably used in combination so as to be effective against various molds and sterilization. As the antifoaming agent, a silicon antifoaming agent is preferable. Among them, emulsification dispersion type and solubilization can be used. The range of 0.01 to 1.0% by mass is optimal.

Further, a chelate compound may be added. Preferred chelate compounds include, for example, ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, sodium salt thereof; ethylenediamine disuccinic acid, potassium salt thereof. Triethylenetetramine hexaacetic acid, potassium salt thereof, sodium salt thereof, hydroxyethylethylenediaminetriacetic acid, potassium salt thereof, sodium salt thereof: nitrilotriacetic acid, sodium salt thereof; 1-hydroxyethane-1,1-diphosphone Acids, potassium salts, sodium salts; organic phosphonic acids or phosphonoalkanetricarboxylic acids such as aminotri (methylenephosphonic acid), potassium salts, sodium salts, etc. It can be mentioned.

An organic amine salt is also effective in place of the sodium salt and potassium salt of the chelating agent. These chelating agents are selected so that they are stably present in the gum solution composition and do not impair the printability. The addition amount is suitably 0.001 to 1.0% by mass.

In addition to the above components, a sensitizer can be added if necessary. For example, hydrocarbons such as turpentine oil, xylene, toluene, low heptane, solvent naphtha, kerosene, mineral spirit, petroleum fraction having a boiling point of about 120 ° C to about 250 ° C, such as dibutyl phthalate, dihebutyl phthalate, di-n-octyl Phthalic acid diester agents such as phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, dilauryl phthalate, butyl benzyl phthalate, such as dioctyl adipate, butyl glycol adipate, dioctyl azelate, dibutyl sebacate, di ( 2-ethylhexyl) aliphatic dibasic acid esters such as sebacate and dioctyl sebacate, epoxidized triglycerides such as epoxidized soybean oil, such as tricresyl phosphate, trioctylfolate Feto, phosphoric acid esters such as tris chloroethyl phosphate, for example, freezing point, such as benzoic acid esters of benzyl benzoate and at 15 ℃ below boiling point at one atmosphere include 300 ° C. or more plasticizers.

In addition, caproic acid, enanthic acid, caprylic acid, helargonic acid, capric acid, undecyl acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, lignoserine Saturated fatty acids such as acid, serotic acid, heptacosanoic acid, montanic acid, melicinic acid, lactelic acid and isovaleric acid, acrylic acid, crotonic acid, isocrotonic acid, undecylenic acid, oleic acid, elaidic acid, celetic acid, nillic acid, buteticidin Examples also include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiolic acid, stearolic acid, sardine acid, talylic acid and licanoic acid. More preferred are fatty acids which are liquid at 50 ° C., more preferred are those having 5 to 25 carbon atoms, and most preferred are those having 8 to 21 carbon atoms. These sensitizers can be used alone or in combination of two or more. A preferable range of the amount used is 0.01 to 10% by mass, and a more preferable range is 0.05 to 5% by mass.

(Automatic processor)
It is advantageous to use an automatic processor for developing the photosensitive lithographic printing plate material.

The automatic developing machine may have a pretreatment unit that immerses the plate in the pretreatment liquid before the development process. The pretreatment section is preferably provided with a mechanism for spraying the pretreatment liquid onto the plate surface, and preferably provided with a mechanism for controlling the temperature of the pretreatment liquid to an arbitrary temperature of 25 to 55 ° C. Is provided with a mechanism for rubbing the plate surface with a roller-like brush. Water or the like is used as the pretreatment liquid.

In addition, it is preferable that the self-existing machine is provided with a heat treatment step for performing the above-described post-exposure heat treatment before the entrance of the developing tank.

In addition, this self-machine can be connected to a conveyor from the plate discharge port of the exposure machine and installed so that the plate is automatically loaded into the self-machine. Further, the conveyor connecting portion is shielded from light by the cover member, and it can be preferably installed so that the plate before exposure and before development is not exposed to illumination light in the working environment.

(Post-processing)
The photosensitive lithographic printing plate material developed with the developer is subjected to a post-treatment with a washing water, a rinse liquid containing a surfactant, a finisher mainly composed of gum arabic or starch derivatives, or a protective gum liquid. You can also. These treatments can be used in various combinations. For example, the treatment with a rinsing solution containing development->washing-> surfactant or the development->washing-> finisher solution is preferable because of less fatigue of the rinse solution and the finisher solution. Furthermore, a countercurrent multistage process using a rinse liquid or a finisher liquid is also a preferred embodiment.

These post-processing are generally performed using an automatic developing machine including a developing unit and a post-processing unit. As the post-treatment liquid, a method of spraying from a spray nozzle or a method of immersing and conveying in a treatment tank filled with the treatment liquid is used. A method is also known in which a fixed amount of a small amount of washing water is supplied to the plate surface after development, and the waste liquid is reused as dilution water for the developer stock solution. In such automatic processing, processing can be performed while each replenisher is replenished with each replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable treatment method in which treatment is performed with a substantially unused post-treatment liquid is also applicable.

In addition, since the developer for developing the photosensitive lithographic printing plate material of the present invention contains a water-soluble resin having a protective gum function, it is preferable that the developer is dried immediately after development without performing the above-described post-treatment. It is. In this case, it is preferable to incorporate a drying zone provided with a hot air dryer or a dryer using radiant heat from a ceramic heater, an infrared lamp, or the like, behind the developing tank of the automatic developing machine.

The lithographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.

Hereinafter, although an example is given and the present invention is explained in detail, the mode of the present invention is not limited to this. In the examples, “parts” represents “parts by mass” unless otherwise specified.

[Production of support]
Using a JIS A 1050 aluminum plate having a thickness of 0.30 mm and a width of 1030 mm, the treatment was continuously performed as follows.

(A) The aluminum plate was subjected to an etching process by spraying at a caustic soda concentration of 2.6 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C. to dissolve 0.3 g / m ^{2 of the} aluminum plate. Thereafter, washing with water was performed by spraying.

(B) A desmut treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (including 0.5% by mass of aluminum ions), and then washed with water by spraying.

(C) An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time contains 1.1% by mass of hydrochloric acid, 0.5% by mass of aluminum ions, and 0.5% by mass of acetic acid. The temperature was 21 ° C. The AC power source was subjected to electrochemical surface roughening treatment using a sine wave alternating current having a time TP of 2 msec until the current value reached a peak from zero, using a carbon electrode as a counter electrode. The current density was an effective value of 50 A / dm ² , and the energization amount was 900 C / dm ² . Then, water washing by spraying was performed.

(D) A desmut treatment was performed for 10 seconds with a phosphoric acid concentration 20 mass% aqueous solution (containing 0.5 mass% of aluminum ions) at a temperature of 60 ° C., and then washed with water by spraying.

(E) An anodizing apparatus of an existing two-stage feed electrolytic treatment method (first and second electrolysis unit length 6 m, first feed unit length 3 m, second feed unit length 3 m, first and second feed electrode lengths 2.4 m each ) Was used to perform anodizing at a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions) at a temperature of 38 ° C. Thereafter, washing with water was performed by spraying.

At this time, in the anodizing device, the current from the power source flows to the first power supply electrode provided in the first power supply unit, flows to the plate-like aluminum via the electrolytic solution, An oxide film is formed on the surface, passes through the electrolytic electrode provided in the first power feeding portion, and returns to the power source.

On the other hand, the current from the power source flows to the second power feeding electrode provided in the second power feeding portion, similarly flows to the plate-like aluminum via the electrolytic solution, and an oxide film is formed on the surface of the plate-like aluminum by the second electrolysis portion. Although the amount of electricity fed from the power source to the first feeding unit and the amount of electricity fed from the power source to the second feeding unit are the same, the feeding current density on the oxide film surface in the second feeding unit is about It was 25 A / dm ² . In the 2nd electric power feeding part, it came to feed from the oxide-film surface of 1.35 g / m < ² >. The final oxide film amount was 2.7 g / m ² . Furthermore, after spray water washing, it was immersed in 0.4 mass% polyvinylphosphonic acid solution for 30 seconds, and was hydrophilized. The temperature was 85 ° C. Thereafter, it was washed with spray water and dried with an infrared heater. At this time, the center line average roughness (Ra) of the surface was 0.65 μm.

(Preparation of photosensitive lithographic printing plate material)
On the support, photosensitive layer coating solutions P-1 to 4 and RP-1, 2 having the composition shown in Table 1 were applied with a wire bar so that the drying rate was 1.5 g / m ^2. Dry for 5 minutes.

Binder (1): 30% by weight concentration of dawanol PM solution of copolymer (Mw = 50,000) in a weight ratio of 59:41 between methyl methacrylate and tetraethylene glycol monomethyl ether methacrylate. Monomer (1): 88.2% MEK solution of the mixture (molecular weight = 471,2 functional)
Monomer (2): Pentaerythritol tetraacrylate (molecular weight = 352, tetrafunctional)
Pigment dispersion (1): MEK dispersion of copper phthalocyanine. Pigment concentration 20% by weight, dispersant polymer concentration 15% by weight
Sensitizer (1): N-butylacridone radical generator (1): Hexaarylbisimidazole compound Speedcure
BCIM (manufactured by Lambson)

Thereafter, an oxygen barrier layer coating solution having the following composition was further applied with a wire bar so as to be 2.0 g / m ² at the time of drying, and dried at 80 ° C. for 1.0 minute. -1 to 4 and RP-1, 2 were prepared.

(Oxygen barrier coating liquid)
Polyvinyl alcohol (Mowiol 4-98: saponification degree 98%) 50.0 parts Polyvinyl alcohol (Mowiol 4-88: saponification degree 88%) 50.0 parts Surfynol 465 (surfactant manufactured by Air Products) 0.2 part 900 parts of water Using a plate setter Mako4 (manufactured by ECRM) equipped with a light source of 405 nm in a yellow safety light environment, a sample of the photosensitive lithographic printing plate material produced by the above method was used, and the resolution was 2400 dpi (dpi and Represents the number of dots per 2.54 cm), the number of lines is 175 LPI (LPI is one inch, that is, the number of lines per 2.54 cm), and the exposure value (Exposure Value) is 100 to expose the image data. It was.

After the exposure, each photosensitive lithographic printing plate material sample having a size of 550 cm × 400 cm was subsequently heat-treated at 105 ° C. for 30 seconds in an environment of red safety light, and then washed with running water to remove the oxygen blocking layer. Thereafter, the surface is rubbed with a sponge while immersed in 2 liters of developer 1 having the following composition for 30 seconds to completely remove the unexposed portions, and a lithographic printing plate sample corresponding to the photosensitive lithographic printing plate material, respectively. Samples P-1 to 4 and RP-1 and 2 were obtained.

(Developer 1)
White dextrin 5.0% by mass
Hydroxypropyl etherified starch 10.0% by mass
Gum arabic 1.0% by mass
1st Ammon Phosphate 0.1% by mass
Sodium dilauryl succinate 0.15% by mass
Polyoxyethylene naphthyl ether 0.5% by mass
Polyoxyethylene polyoxypropylene block copolymer (ethylene oxide ratio 50 mol%, molecular weight 5000) 0.3 mass%
Ethylene glycol 1.0% by mass
1,2-Benzisothiazolin-3-one 0.005% by mass
Citric acid (add the amount that makes pH = 4.5)
Using the above lithographic printing plate, with a printing machine (GTO manufactured by Heidelberg), coated paper, printing ink (Toyo King High Echo M Red manufactured by Toyo Ink Co., Ltd.) and dampening water (H Liquid manufactured by Tokyo Ink Co., Ltd.) Printing was performed using SG-51 density 1.5%.

In printing, the ink fillability of the image part of the printed 20th printed product and the stain of the non-image part were evaluated and used as an index of initial printability. Further, after that, 50,000 copies were printed, and it was visually confirmed whether or not there was a defect in the printed image, and the printing durability was evaluated. The results are shown in Table 2.

(Evaluation criteria)
The presence or absence of image defects in the printed material of 50,000 copies was evaluated according to the following criteria.

◎; No problem at all ○: Although there is a defect of 3% or less of small dots, it is good as an image △; Although there is a defect of 5% or less of small dots, it is acceptable as an image ×; Is missing xx; halftone dots of less than 10% are missing, and the solid portion is also distorted.

From Table 2, it can be seen that the planographic printing plate of the present invention has excellent initial printing suitability and excellent printing durability.

Claims (6)

1. After exposing and recording image information, a plate making method for producing a lithographic printing plate by removing an unexposed portion with a developer containing a water-soluble resin and a surfactant and having a pH of 3.0 to 9.0. In the photosensitive lithographic printing plate material used, the photosensitive lithographic printing plate material has a photosensitive layer containing a sensitizer, a radical generator, a polymerizable monomer and a binder on a support having a hydrophilic surface. And the total of methacryloyl groups and acryloyl groups contained in the molecule of the polymerizable monomer is 2.5 to 3.5 mmol / g with respect to the total mass of the photosensitive layer. Printing plate material.
2. After exposing and recording image information with a laser light source having an emission wavelength in the range of 350 nm to 450 nm, an unexposed portion is developed with a developer containing a water-soluble resin and a surfactant and having a pH in the range of 3.0 to 9.0. In the photosensitive lithographic printing plate material used in the plate making method for producing a lithographic printing plate by removing the lithographic printing plate, the photosensitive lithographic printing plate material is formed on a support having a hydrophilic surface, a sensitizer, a radical generator, The photosensitive layer contains a polymerizable monomer and a binder, and the total of methacryloyl and acryloyl groups contained in the polymerizable monomer molecule is 2.5 to 3.5 mmol / g based on the total weight of the photosensitive layer. A photosensitive lithographic printing plate material, characterized in that
3. The photosensitive property according to claim 1 or 2, wherein the total of the methacryloyl group and the acryloyl group is a concentration of 2.9 to 3.5 mmol / g with respect to the total mass of the photosensitive layer. Planographic printing plate material.
4. The photosensitive lithographic printing plate material according to any one of claims 1 to 3, wherein the content of the polymerizable monomer in the photosensitive layer is 40 to 60 mass%.
5. The photosensitive lithographic printing plate material according to any one of claims 1 to 4, wherein the radical generator is a hexaarylbiimidazole compound.
6. The photosensitive lithographic printing plate material according to any one of claims 1 to 5, further comprising an oxygen blocking layer having polyvinyl alcohol as a component on the photosensitive layer.