JP2002244277A - Photosensitive planographic printing plate and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planographic printing plate giving satisfactory image strength and printing resistance to an image obtained by scanning exposure with laser light. SOLUTION: In the photosensitive planographic printing plate having a photopolymerizable photosensitive layer containing an ethylenically unsaturated compound, a photopolymerization initiating system and a polymer binder on a substrate, the polymer binder consists essentially of a polymer binder (C1) which is a copolymer having an allyl type or vinyl type unsaturated bond in a side chain and a polymer binder (C2) which is typically a copolymer containing a (meth)acrylic ester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photosensitive lithographic printing plate. Specifically, the present invention relates to a photosensitive lithographic printing plate having a photopolymerizable photosensitive layer containing an ethylenically unsaturated compound, a photopolymerization initiation system and a polymer binder on an aluminum support, Regarding improvement.

[0002]

2. Description of the Related Art Conventionally, as a method for forming an image by exposing a photopolymerizable composition, a photosensitive composition comprising a photopolymerizable composition comprising an ethylenically unsaturated compound and a photopolymerization initiator, or further comprising a polymer binder is used. After forming a layer on the surface of the support, exposing and polymerizing and curing the ethylenically unsaturated compound in the photopolymerizable composition in the exposed portion, a cured relief image is formed by dissolving and removing the non-exposed portion. The method is universal.
In recent years, as an exposure method, an argon ion laser, an FD-YAG laser, which can greatly improve productivity,
Attention has been paid to scanning exposure with laser light such as a semiconductor laser and a YAG laser, and in particular, light of a wavelength of 488 nm of an argon ion laser as a visible light laser, FD-YA
Light with a wavelength of 532 nm of a G laser is promising.

[0003] Higher sensitivity of the photopolymerizable composition corresponding to the laser scanning exposure has been actively studied, but the high-speed scanning exposure by the laser beam still has insufficient sensitivity.
It was difficult to form an image having sufficient strength. on the other hand,
Studies have been made to improve the image intensity by processing after laser scanning exposure. For example, a method of performing heat treatment after laser scanning exposure and before development processing, and a method of further post-exposure after development processing have been proposed. For example, Japanese Patent Application Laid-Open No. 6-1
The inventions described in JP-A-48885 and JP-A-6-289611 are characterized by the composition of the photosensitive layer. In the examples, post-exposure after development is described.

The high-sensitivity photosensitive layer suitable for such laser scanning exposure has a different composition from that of a photosensitive layer such as a carbon arc lamp, a mercury lamp, or a metallohalide lamp which is exposed to an ordinary light through an original image, and is based on aluminum. It was found that there was a problem in the adhesion to the support. As a countermeasure, methods such as heat treatment and post-exposure are known, but in such a case, a dedicated heat treatment device or post-exposure device is required, which leaves problems in cost, installation place, workability, and the like. . This adhesiveness is closely related to the printing durability.

As an attempt to improve the adhesion between the photosensitive layer and the support, the support is roughened by a mechanical, chemical, or electrochemical method, and subsequently, a chemical etching treatment, an anodic oxidation treatment, a chemical conversion treatment, and a hydrophilic treatment are performed. Various methods have been proposed for controlling the surface state of the support by combining various kinds of treatments such as a chemical conversion treatment, a sealing treatment, and a primer coating treatment. On the other hand, many proposals have been made on the improvement of the photosensitive layer side with regard to the structure, properties, compounding amount and the like of the ethylenically unsaturated compound, the photopolymerization initiation system and the polymer binder constituting the main ingredient of the photosensitive layer. Also, various additives for the photosensitive layer such as a thermal polymerization inhibitor, an antifoaming agent, a colorant, a plasticizer, a surfactant, a development accelerator, and a storage stabilizer have been proposed.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lithographic printing plate having a photosensitive layer on the surface of a support, in which the adhesion between the support and the photosensitive layer is increased and the printing durability of the lithographic printing plate is improved. And to improve the chemical resistance of the lithographic printing plate. In particular, the present invention provides a lithographic printing plate that imparts sufficient printing durability and chemical resistance to an image obtained by scanning exposure with a laser beam.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a photosensitive layer containing an ethylenically unsaturated compound, a photopolymerization initiation system and a polymer binder has a polymer bond. By using a combination of specific polymer binders with different structures and properties,
The inventors have found that the above object can be achieved and completed the present invention.

That is, the present invention provides a photosensitive composition having a photopolymerizable photosensitive layer containing an ethylenically unsaturated compound (A), a photopolymerization initiation system (B), and a polymer binder (C) on a support. In a lithographic printing plate, the polymer binder is at least
The following polymer binder (C1) and polymer binder (C2)
Or a photosensitive lithographic printing plate.

Polymer binder (C1): General formula (1)

[0010]

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(Wherein, R ^{3 to} R ⁷ each independently have 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, and a substituent. Alkyl group which may be substituted, alkoxy group which may have a substituent, alkylamino group which may have a substituent, alkylsulfonyl group which may have a substituent, An aryl group which may be substituted, an aryloxy group which may have a substituent, an arylamino group which may have a substituent,
Or an arylsulfonyl group which may have a substituent; Is an oxygen atom, a sulfur atom, an imino group, or
Shows an alkylimino group. ) Or general formula (2)

[0012]

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Wherein R ^{3 to} R ⁵ and Z Indicates the same as above. ) And one or more polymerizable unsaturated groups represented by general formula (3)

[0014]

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(Wherein R ⁰ independently represents a hydrogen atom or a methyl group, and Z ⁰ represents an oxygen atom or an imino group). Copolymer having a monomer having an unsaturated bond as a copolymer component, polymer binder (C2): general formula (4)

[0016]

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Wherein R ¹ is an alkyl group having 1 to 15 carbon atoms, R ² is a hydrogen atom or a methyl group, and R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkyl An amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, an alkylsulfonyl group which may have a substituent, Indicates the same as above. A) a copolymer having a monomer having one unsaturated group represented by formula (1) as a copolymer component.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive lithographic printing plate of the present invention comprises the following components on a support: (A) an ethylenically unsaturated compound, (B) a photopolymerization initiation system, and (C) a polymer binder. A photosensitive layer comprising a photopolymerizable composition is formed.

Here, the ethylenically unsaturated compound as the component (A) of the photopolymerizable composition constituting the photosensitive layer includes:
When the photopolymerizable composition is irradiated with actinic rays,
(B) A monomer having an ethylenically unsaturated bond that undergoes addition polymerization by the action of a photopolymerization initiation system as a component, and in some cases, crosslinks and cures. In addition, the meaning of the monomer here is a concept corresponding to a so-called polymer, and in addition to the monomer in a narrow sense, includes a dimer, a trimer, and other oligomers. I do. In addition, the photopolymerization initiation system means a combination of a radical generator (photopolymerization initiator) and a sensitizer.

In the present invention, as the ethylenically unsaturated compound as the component (A), a compound having one ethylenically unsaturated bond in one molecule, specifically, for example, (meth)
Acrylic acid [In the present invention, “(meth) acryl” means acryl and methacryl. Unsaturated carboxylic acids such as crotonic acid, isocrotonic acid, maleic acid, itaconic acid, and citraconic acid, and alkyl esters thereof, (meth) acrylonitrile, (meth) acrylamide, and styrene; Compounds having two or more saturated bonds in one molecule are preferred.

Typical examples of the polyfunctional ethylenically unsaturated compound include esters of a polyhydroxy compound and an unsaturated carboxylic acid, and urethane (meth) acrylate of a polyisocyanate compound and a hydroxyalkyl (meth) acrylate compound. And epoxy (meth) acrylates of a polyepoxy compound and a (meth) acrylic acid or a hydroxyalkyl (meth) acrylate compound, and phosphates having a (meth) acryloyloxy group.

Specific examples of the esters include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, tripropylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol, and hexamethylene. Glycol, nonamethylene glycol, trimethylolethane, tetramethylolethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol,
Sorbitol and its reaction products of aliphatic polyhydroxy compounds such as ethylene oxide adducts, propylene oxide adducts, diethanolamine, triethanolamine and the like with unsaturated carboxylic acids as described above, for example, ethylene glycol (Meth) acrylate, diethylene glycol di (meth) acrylate,
Triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, hexamethylene glycol di (meth) acrylate, nonamethylene glycol di (meth) acrylate, trimethylolethanetri (meth) acrylate, tetramethylolethanetri (meth) acrylate, trimethylolpropanedi (meth) acrylate, trimethylol Propane tri (meth) acrylate, trimethylolpropane ethylene oxide added tri (meth) acrylate, glycerol di (meth) acrylate Glycerol tri (meth) acrylate, glycerol propylene oxide addition tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth)
Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol di (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, sorbitol tri (meth) acrylate, sorbitol tetra (meth) acrylate, sorbitol penta (meth) acrylate, sorbitol hexa (meth)
Acrylates and the like, and similar crotonates, isocrotonates, maleates, itaconates, citraconates and the like can be mentioned.

Further, as the esters, a reaction product of an aromatic polyhydroxy compound such as hydroquinone, resorcinol, pyrogallol and an unsaturated carboxylic acid, specifically,
For example, a reaction product of a heterocyclic polyhydroxy compound such as hydroquinone di (meth) acrylate, resorcinol di (meth) acrylate, pyrogallol tri (meth) acrylate, and tris (2-hydroxyethyl) isocyanurate with an unsaturated carboxylic acid Specifically, for example, di (meth) acrylate and tri (meth) acrylate of tris (2-hydroxyethyl) isocyanurate, and a reaction product of a polyhydroxy compound, an unsaturated carboxylic acid, and a polycarboxylic acid Specifically, for example, a condensate of ethylene glycol with (meth) acrylic acid and phthalic acid, a condensate of diethylene glycol with (meth) acrylic acid and maleic acid, pentaerythritol, (meth) acrylic acid and terephthalic acid With butanediol, glycerin and (meth) Condensates of acrylic acid and adipic acid.

Examples of the urethane (meth) acrylates include, for example, hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine methyl ester diisocyanate, lysine methyl ester triisocyanate, dimer acid Aliphatic polyisocyanates such as diisocyanate, 1,6,11-undecatriisocyanate, 1,3,6-hexamethylenetriisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, cyclohexane diisocyanate, dimethylcyclohexane diisocyanate, 4, Alicyclic polyisocyanates such as 4'-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, and bicycloheptane triisocyanate; p-phenylene diisocyanate,
2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, tolidine diisocyanate, 1,5-naphthalene diisocyanate, tris (isocyanate phenyl methane) , Aromatic polyisocyanates such as tris (isocyanatephenyl) thiophosphate, polyisocyanate compounds such as heterocyclic polyisocyanates such as isocyanurate, hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycerol di (meth) acrylate , Pentaerythritol tri (meth) acrylate,
Reaction products with a hydroxyalkyl (meth) acrylate compound such as tetramethylolethane tri (meth) acrylate are exemplified.

Examples of the epoxy (meth) acrylates include (poly) ethylene glycol polyglycidyl ether, (poly) propylene glycol polyglycidyl ether, (poly) tetramethylene glycol polyglycidyl ether, (Poly) pentamethylene glycol polyglycidyl ether, (poly) neopentyl glycol polyglycidyl ether,
Aliphatic polyepoxy compounds such as (poly) hexamethylene glycol polyglycidyl ether, (poly) trimethylolpropane polyglycidyl ether, (poly) glycerol polyglycidyl ether, (poly) sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, triglycidyl Heterocyclic polyepoxy compounds such as isocyanurate, triglycidyl tris (2-hydroxyethyl) isocyanurate, phenol novolak polyepoxy compound, brominated phenol novolak polyepoxy compound, (o-, m-, p-) cresol novolak polyepoxy Compounds, bisphenol A polyepoxy compounds, bisphenol F polyepoxy compounds and other aromatic polyepoxy compounds such as polyepoxy compounds, and (meth) a Reaction products of acrylic acid or hydroxyalkyl (meth) acrylate compounds.

As the phosphates having a (meth) acryloyloxy group, specifically, those represented by the following general formula (Ia) or (Ib) are preferable.

[0027]

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[In the formulas (Ia) and (Ib), R ¹⁰ represents a hydrogen atom or a methyl group, n is an integer of 1 to 25, m is 1, 2,
Or 3. Here, n is preferably from 1 to 10, particularly preferably from 1 to 4. Specific examples thereof include, for example, (meth) acryloyloxyethyl phosphate, bis [(meth) acryloyloxyethyl] phosphate, (meth) ) Acryloyloxyethylene glycol phosphate and the like, which may be used alone or as a mixture.

Other polyfunctional ethylenically unsaturated compounds other than the above include, for example, ethylene bis (meth)
Examples thereof include (meth) acrylamides such as acrylamide, allyl esters such as diallyl phthalate, and vinyl group-containing compounds such as divinyl phthalate.

In the present invention, in view of exposure sensitivity, printing durability, developability, etc. as a photosensitive layer, the (A) component has the above-mentioned (meth) acryloyloxy group as the ethylenically unsaturated compound. It is preferable to contain phosphates, and the content of the phosphates in the whole ethylenically unsaturated compound is 1 to 60% by weight, particularly 5 to 5% by weight.
It is preferably 0% by weight.

In the present invention, the photopolymerization initiation system as the component (B) of the photopolymerizable composition constituting the photosensitive layer generally comprises a radical generator (photopolymerization initiator) and a sensitizer, and in some cases, Further, it contains a polymerization accelerator. The radical generator is a compound that generates an active radical when the photopolymerizable composition is irradiated with an actinic ray and causes the ethylenically unsaturated compound as the component (A) to polymerize, Those having sensitivity in the ultraviolet to near-infrared light region can be mentioned. In particular, those sensitive to the visible light region are preferable, and examples thereof include titanocenes, hexaarylbiimidazoles, halogenated hydrocarbon derivatives, diaryliodonium salts, and organic peroxides.
Among them, titanocenes and hexaarylbiimidazoles are preferable, and titanocenes are particularly preferable, in view of sensitivity as a photopolymerizable composition, adhesion to a support, and storage stability.

Examples of the titanocenes include compounds described in JP-A-59-152396 and JP-A-61-151197, for example, dicyclopentadienyltitanium dichloride, dicyclopentadienyl Titanium bisphenyl, dicyclopentadienyl titanium bis (2,4-difluorophenyl), dicyclopentadienyl titanium bis (2,6-difluorophenyl), dicyclopentadienyl titanium bis (2,4,6- Trifluorophenyl), dicyclopentadienyl titanium bis (2,3,5,6-tetrafluorophenyl), dicyclopentadienyl titanium bis (2,3,4,5,6-pentafluorophenyl), (Methylcyclopentadienyl) titanium bis (2,6-difluoro Phenyl), di (methylcyclopentadienyl) titanium bis (2,3,4,5,6
-Pentafluorophenyl), dicyclopentadienyltitanium bis [2,6-difluoro-3- (1-pyrrolyl) phenyl] and the like.

The hexaarylbiimidazoles include, for example, 2,2′-bis (o-chlorophenyl)-
4,4 ′, 5,5′-tetra (p-chlorophenyl) biimidazole, 2,2′-bis (o-chlorophenyl)
-4,4 ', 5,5'-tetra (o, p-dichlorophenyl) biimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (p-fluorophenyl) ) Biimidazole, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (o, p-
Dibromophenyl) biimidazole, 2,2'-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-
Tetra (o, p-dichlorophenyl) biimidazole,
2,2′-bis (o-bromophenyl) -4,4 ′,
5,5'-tetra (o, p-dichlorophenyl) biimidazole, 2,2'-bis (o-bromophenyl)-
4,4 ′, 5,5′-tetra (p-iodophenyl) biimidazole, 2,2′-bis (o-bromophenyl)
-4,4 ', 5,5'-tetra (o-chloro-p-methoxyphenyl) biimidazole, 2,2'-bis (o-
(Chlorophenyl) -4,4 ', 5,5'-tetra (p-
Hexaarylbiimidazole compounds having a halogen-substituted aromatic ring such as chloronaphthyl) biimidazole. These hexaarylbiimidazole compounds include, for example, Bull.Chem.Soc.Japan; 33,565 (1960), J.Or
g. Chem .; 36, 2262 (1971) and the like.

As the sensitizer for activating the radical generator at the time of irradiation with actinic rays to effectively generate active radicals, those having a sensitivity in the visible light region are particularly preferable. No. 3479185, triphenylmethane-based leuco dyes such as leuco crystal violet and leucomalachite green, photoreducing dyes such as erythrosin and eosin Y,
Aminophenyl ketones such as Michler's ketone and aminostyryl ketone disclosed in U.S. Pat. Nos. 3,549,367 and 3,652,275;
Β-diketones disclosed in US Pat. No. 4,790,464, indanones disclosed in US Pat. No. 4,162,162, JP-A-6-301208, JP-A-8-12925.
No. 8, JP-A-8-129259, JP-A-8-1466
Coumarin-based pigments disclosed in JP-A Nos. 05-111605 and 8-221605, ketocoumarin-based pigments disclosed in JP-A-52-112681, and JP-A-59-564.
Aminostyrene derivatives and aminophenylbutadiene derivatives disclosed in U.S. Pat.
No. 10, aminophenyl heterocycles disclosed in U.S. Pat. No. 4,966,830; julolidine heterocycles disclosed in U.S. Pat. No. 4,966,830;
Compounds such as pyromethene pigments disclosed in each publication of No. 5885 are exemplified. Among them, coumarin pigments and pyromethene pigments are preferred.

Examples of the polymerization accelerator for enhancing the photopolymerization initiation ability include 2-mercaptobenzothiazole,
Mercapto group-containing compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 3-mercapto-1,2,4-triazole; N, N-dialkylaminobenzoic acid ester; N-phenylglycine; N-aryl-α-amino acids or derivatives thereof such as salts such as sodium salts, derivatives such as esters thereof, N-phenylalanine, or salts thereof such as ammonium and sodium salts, derivatives thereof such as esters, and the following general formula: And hydrogen-donating compounds such as the compounds represented by (II).

[0036]

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[In the formula (II), R ¹¹ represents a hydrogen atom or an alkyl group which may have a substituent, R ¹² represents a hydrogen atom, an alkyl group which may have a substituent, A vinyl group which may have a group, an allyl group which may have a substituent, an (meth) acryloyloxy group which may have a substituent, an aryl group which may have a substituent ,
Or represents an aromatic heterocyclic group which may have a substituent,
The benzene ring may have a substituent, and p is 2 to 10.
Is an integer. ]

Here, examples of the substituent of the benzene ring include an alkyl group which may have a substituent, an alkoxy group which may have a substituent, and an acyl group which may have a substituent. Group, an alkoxycarbonyl group which may have a substituent, a vinyl group which may have a substituent, an allyl group which may have a substituent, and a group which may have a substituent (meth A) an acryloyloxy group, an aryl group which may have a substituent, or an aromatic heterocyclic group which may have a substituent.

A feature of the present invention is that a specific polymer binder (C1) or (C2) is used in combination as the component (C) of the photopolymerizable composition constituting the photosensitive layer. . Hereinafter, each polymer binder will be described. The polymer binder (C1) has the general formula (1)

[0040]

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(Wherein, R ^{3 to} R ⁷ each independently have 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, and a substituent. Alkyl group which may be substituted, alkoxy group which may have a substituent, alkylamino group which may have a substituent, alkylsulfonyl group which may have a substituent, An aryl group which may be substituted, an aryloxy group which may have a substituent, an arylamino group which may have a substituent,
Or an arylsulfonyl group which may have a substituent; Is an oxygen atom, a sulfur atom, an imino group, or
Shows an alkylimino group. ) Or general formula (2)

[0042]

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Wherein R ³ -R ⁵ and Z Indicates the same as above. ) And one or more polymerizable unsaturated groups represented by general formula (3)

[0044]

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(Wherein R ⁰ independently represents a hydrogen atom or a methyl group, and Z ⁰ represents an oxygen atom or an imino group). Is a copolymer having a monomer having an unsaturated bond as a copolymer component. Examples of the monomer having the polymerizable unsaturated group represented by the general formula (1) and the polymerizable unsaturated group represented by the general formula (3) include, for example, allyl (meth) acrylate, 3-allyloxy-2-hydroxy Propyl (meth) acrylate, N-allyl (meth) acrylamide, cinnamyl (meth) acrylate, crotonyl (meth) acrylate, methallyl (meth) acrylate, allyl crotonate, 3-allyloxy-2-hydroxypropyl crotonate, and the like. . Of these, allyl (meth) acrylate is particularly preferred.

Examples of the monomer having a polymerizable unsaturated group represented by the general formula (2) and a polymerizable unsaturated group represented by the general formula (3) include vinyl (meth) acrylate and vinyl crotonate. , 1-propenyl (meth) acrylate, 1-chlorovinyl (meth) acrylate,
2-phenylvinyl (meth) acrylate, vinyl (meth) acrylamide, 1-chlorovinylcrotonate,
1-propenyl crotonate and the like. Of these, vinyl (meth) acrylate is particularly preferred.

The polymer binder (C1) can be produced by copolymerizing these monomers with other monomers having a polymerizable unsaturated group. Other monomers include unsaturated carboxylic acids, methyl (meth) acrylate,
Ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylonitrile, styrene, methylstyrene, vinyl acetate, vinyl chloride, vinylidene chloride, maleimide and the like can be used. Unsaturated carboxylic acids such as acid, methacrylic acid, maleic anhydride, itaconic acid, maleic acid, crotonic acid, isocrotonic acid and citraconic acid, and particularly preferably acrylic acid or methacrylic acid are used.

By copolymerizing each of the above monomers, the polymerizable unsaturated group represented by the general formula (3) is preferentially polymerized to obtain an acrylic copolymer. The copolymer includes a polymerizable unsaturated group represented by the general formula (1) (allyl-type polymerizable unsaturated group) or a polymerizable unsaturated group represented by the general formula (2) (vinyl-type polymerizable Most of the unsaturated group) remains without being polymerized. This is because the polymerizable unsaturated group (acrylic polymerizable unsaturated group) represented by the general formula (3) has a higher polymerization activity than the former.

The proportion of the monomer having the structure of the general formula (1) or the general formula (2) in the whole copolymer, that is, in the polymer binder (C1) is 10 to 90 mol%, preferably 30 to 90 mol%. 80 mol%. If it is less than this range, the image reproducibility is poor, and if it is too large, the developability deteriorates. When an unsaturated carboxylic acid is used as another monomer, a carboxyl group can be introduced into the polymer binder (C1), which is preferable. The amount of the unsaturated carboxylic acid to be used is preferably such that the acid value of the polymer binder (C1) is 10 to 250. The acid value of the polymer binder having a carboxyl group is calculated as follows. For example, in a copolymer of monomers A, B and C, when one carboxyl group is present in monomer C, the acid value of the polymer binder is c / ([A] × a + [B] × b + [ C] × c) × 56.
Calculated as 1 × 1000. Here, [A], [B], and [C] represent the molecular weights of monomers A, B, and C, and a, b, and c represent the copolymerization rates of monomers A, B, and C.

The reaction method for the copolymerization is not particularly limited, but the following method is exemplified. A predetermined amount of a monomer having the structure of the general formula (1) or the general formula (2) and a suitable other monomer is dissolved in a reaction solvent such as ethanol, and a solution such as azobisisobutyronitrile (AIBN) is dissolved. A polymerization initiator is added, and usually 50
It is manufactured by a conventional method in which the reaction is carried out at -100 ° C for 1-20 hours. After completion of the reaction, propylene glycol monomethyl ether acetate (PGM-A
C) and the like are added and diluted, and finally ethanol is removed to obtain a PGM-AC solution of the copolymer. Polymer binder (C1)
Has a weight average molecular weight of 10,000 to 1,000,000
0, preferably 30,000 to 700,000.

The polymer binder (C2) has the general formula (4)

[0052]

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Wherein R ¹ is an alkyl group having 1 to 15 carbon atoms, R ² is a hydrogen atom or a methyl group, and R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkyl An amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, an alkylsulfonyl group which may have a substituent, Indicates the same as above. ) Is a copolymer containing a monomer having one unsaturated group as a copolymer component.

The monomers represented by the general formula (4) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth) acrylate. , (Meta)
Octyl acrylate, lauryl (meth) acrylate, β
-Methyl chloro (meth) acrylate, ethyl β-methoxycarbonyl (meth) acrylate, N-butyl (meth) acrylate
Acrylamide, octyl β-cyano (meth) acrylate and the like can be mentioned, and these are used alone or in combination of two or more.

Further, these monomers include acrylic acid,
It can be used in combination with other monomers such as methacrylic acid, maleic anhydride, unsaturated carboxylic acids such as itaconic acid, (meth) acrylonitrile, styrene, methylstyrene, vinyl acetate, vinyl chloride, vinylidene chloride, and maleimide. The proportion of the monomer represented by the general formula (4) in the polymer binder (C2) is 5 to 95 mol%,
Preferably it is 10-85 mol%. If it is less than this range, the image reproducibility is poor, and if it is too large, the developability deteriorates.
When an unsaturated carboxylic acid is used as another monomer, a carboxyl group can be introduced into the polymer binder (C2), which is preferable. The amount of the unsaturated carboxylic acid to be used is preferably such that the acid value of the polymer binder (C2) is 10 to 250. The copolymerization can be carried out in the same manner as in the case of the polymer binder (C1).

The performance characteristic of the polymer binder (C1) lies in the formation of a tough photosensitive layer which is strong in chemical resistance, but lacks flexibility and therefore has insufficient adhesion to a support. Therefore, there is a weak point that small dots easily fly during printing. On the other hand, the polymer binder (C2) has good adhesiveness to the support, but has a weak point that it easily wears out during printing because it forms a soft photosensitive layer.

The point of the present invention is that the tough polymer binder (C1) is replaced with the polymer binder (C
2), and the mixing weight ratio of the polymer binders (C1) and (C2) is usually (C
1): (C2) = 97: 3 to 10:90, preferably (C1) :( C2) = 90: 10 to 30:70. In other words, the polymer binder (C1) is used in a proportion containing 10 to 97% by weight and the polymer binder (C2) 3 to 90% by weight, based on the entire polymer binder.

In the present invention, the proportions of the ethylenically unsaturated compound (A), the photopolymerization initiation system (B) and the polymer binder (C) constituting the photosensitive layer are as follows: The radical generator in the photopolymerization initiation system of the component (B) is usually 0.1 to 80 parts by weight, preferably 0.5 to 100 parts by weight of the ethylenically unsaturated compound of the component A).
６０60 parts by weight, the sensitizer is usually 0.01-20 parts by weight,
Preferably 0.05 to 10 parts by weight, the polymerization accelerator is usually 0.1 to 80 parts by weight, preferably 0.5 to 60 parts by weight, and the polymer binder of the component (C) is the same. (C1)
The total amount of (C2) is usually 10 to 400 parts by weight, preferably 20 to 200 parts by weight.

Further, as the photopolymerizable composition in the present invention, various additives, for example, a thermal polymerization inhibitor such as hydroquinone, p-methoxyphenol and 2,6-di-tert-butyl-p-cresol may be used. 20 parts by weight or less of a colorant comprising an organic or inorganic dye / pigment, 40 parts by weight or less of a plasticizer such as dioctyl phthalate, didodecyl phthalate, and tricresyl phosphate, and sensitivity characteristics such as tertiary amine and thiol. An improver, a coating improver such as a fluorine-based surfactant or the like, and a development accelerator may be contained in a proportion of 10 parts by weight or less and a dye precursor in a proportion of 30 parts by weight or less.

In preparing the lithographic printing plate of the present invention, the photopolymerizable composition is usually applied to the surface of a support as a solution in which the above components are dissolved in an appropriate solvent, and then heated and dried. To form a photosensitive layer comprising the photopolymerizable composition on the surface of a support.

The support is a plate made of aluminum or an alloy containing aluminum as a main component and containing silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel, and the like. 0.01-10
mm, preferably 0.05 to 1 mm.

The aluminum plate support is generally degreased, roughened (grained), desmutted, anodized, prior to forming a photosensitive layer comprising the photopolymerizable composition on its surface. What has been subjected to a sealing treatment, an undercoating treatment and the like is used.

Here, the degreasing treatment includes a method of wiping, dipping, or steam cleaning using a solvent, a method of dipping or spraying with an aqueous alkali solution, and then neutralizing with an aqueous acid solution.
It is performed according to a conventional method such as a method of dipping or spraying using a surfactant.

The surface roughening treatment (graining treatment) includes mechanical treatment methods such as a ball polishing method, a brush polishing method, a blast polishing method, a honing polishing method and a buff polishing method, and electrochemical etching using hydrochloric acid, nitric acid or the like. Method (electrolytic etching method), chemical etching method using an acid or alkali etching agent,
Alternatively, they are performed by appropriately combining them. Among them, brush polishing, ball polishing, liquid honing polishing, electrolytic etching, chemical etching, and the like are preferable, and in particular, electrolytic etching in which hydrochloric acid or nitric acid is used to perform electrolysis with alternating current or direct current. In this case, an acid concentration of about 0.5 to 5% by weight,
The treatment is preferably performed at a current density of about 200 A / dm ^{2 and} a voltage of about 10 to 40 V at a temperature of about 20 to 50 ° C. When sulfuric acid, oxalic acid, or the like is appropriately added during the electrolytic etching method, an oxide film can be formed simultaneously with etching.

Examples of the acid etchant include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and oxalic acid. Examples of the alkaline etchant include sodium hydroxide, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, and the like. Potassium hydroxide, lithium hydroxide and the like are used. These acid or alkali etching agents are usually 0.5
It is used as an aqueous solution of ５０50% by weight, preferably 1-30% by weight, and the treatment is usually carried out at a temperature of 20-100 ° C., preferably 30-80 ° C. On the high temperature and high concentration side, the etching rate is high, which is advantageous for industrial production. However, since there is a problem in control of the surface state and stability, it is usually selected from the above range. Mild etching at a low temperature and low concentration is preferable in terms of uniformity of the surface state of the support. By such a roughening treatment, the surface of the support becomes JIS
The average roughness (Ra) specified in B0601 is 0.1 to
The thickness is about 1.5 μm, preferably about 0.2 to 1.0 μm.

On the surface of the roughened aluminum,
Mechanical polishing scum, by-products during etching, such as aluminum oxide, oxide hydrate, hydroxide, as well as oxides of impurities such as iron, hydroxide, and other substances called smut There is accumulation. The smut formed by electrolytic etching is often in the form of a spud and porous.
The smut is considered to cause dust and dirt in a later step, or has an adverse effect on the adhesiveness to the photosensitive layer, and a step called “desmut” for removing the smut is added.

The desmut treatment may be performed by using an acid such as sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, or chromic acid, or sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium phosphate, sodium pyrophosphate, potassium phosphate, sodium aluminate, or the like. This is performed according to a conventional method such as immersion or spraying using an aqueous alkali solution.

For example, at a concentration of 1 to 4% by weight and a liquid temperature of 0 to 40%
Conditions such as immersion in an aqueous solution of sodium hydroxide at about 1 ° C. for about 1 to 10 seconds can be given. Preferably, 0.3 to 3% by weight of sodium hydroxide aqueous solution having a liquid temperature of 5 to 30 ° C is 1 to 5%.
A second immersion method can be used.

Next, an oxide film is formed to chemically stabilize the desmutted aluminum surface.
Usually, an electrochemical method is used. Anodizing treatment is
Generally, an aqueous solution of sulfuric acid, phosphoric acid, boric acid or the like is used as an electrolytic solution. In particular, an aqueous solution containing mainly sulfuric acid or sulfuric acid and an aqueous solution containing oxalic acid, phosphoric acid, chromic acid, malonic acid, or the like is used. It is preferable from the viewpoint of printability. At that time, the acid concentration is 5
５０50% by weight, preferably 15-30% by weight, current density is 1-60 A / dm ² , preferably 2-50 A / d
The treatment is preferably performed at m ² , voltage of 1 to 150 V, electrolytic bath temperature of 5 to 50 ° C., preferably 15 to 35 ° C., and electrolysis time of about 5 to 60 seconds. The amount of the oxide film formed on the aluminum plate by using these is preferably 1 to 100 mg / dm ² , and particularly preferably 10 to 50 mg / dm ² .

The support subjected to the anodizing treatment is subjected to a sealing treatment as required. This treatment involves boiling water, steam,
This is performed according to a conventional method such as immersion or spraying using an aqueous solution of sodium silicate, an aqueous solution of dichromate, or the like.

The underlining process performed as needed is
A resin containing an acid group or an onium group, a resin having a cationic quaternary ammonium salt group, polyvinylphosphonic acid, starch, a water-soluble polymer such as cellulose, or an aqueous solution of a metal salt such as fluorinated zirconic acid, Or, it is performed according to a conventional method such as spraying.

Further, if necessary, a treatment with an alkali silicate such as sodium silicate or hot water, a dipping treatment of a resin having a cationic quaternary ammonium base or a water-soluble polymer compound such as polyvinyl sulfonic acid in an aqueous solution, etc. Can be applied.

The solvent for coating the photopolymerizable composition solution on the surface of the support is not particularly limited as long as it has sufficient solubility for the components used and gives good coating properties. For example, methyl cellosolve, ethyl cellosolve,
Cellosolve solvents such as methyl cellosolve acetate and ethyl cellosolve acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene Propylene glycol solvents such as glycol dimethyl ether, butyl acetate, amyl acetate, ethyl butyrate, butyl butyrate, diethyl oxalate, ethyl pyruvate, ethyl-2-hydroxybutyrate, ethyl acetoacetate, methyl lactate, ethyl lactate, 3-methoxy Ester solvents such as methyl propionate, heptanol, hexanol, Seton alcohol, alcohol-based solvents such as furfuryl alcohol, cyclohexanone,
Examples thereof include ketone solvents such as methyl amyl ketone, highly polar solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone, and mixed solvents thereof, and those in which an aromatic hydrocarbon is added thereto. The usage ratio of the solvent is usually in the range of about 1 to 20 times by weight based on the total amount of the photopolymerizable composition.

The coating method includes, for example, dip coating, spinner coating, spray coating, roll coating,
A coating rod or the like can be used. The coating amount varies depending on the application, but is usually 0.1 to 1 as a dry film thickness.
0 g / m ^2, preferably in the range of 0.5 to 5 g / m ^2.

The photopolymerizable image-forming material of the present invention is used to prevent the polymerization of the photopolymerizable composition by oxygen on the photosensitive layer of the photopolymerizable composition formed on the surface of the support. It is preferable that an oxygen barrier layer is formed.

The constituents of the oxygen barrier layer are water,
Or, with water, methanol, ethanol, propanol,
A polymer soluble in a mixed solvent with an alcohol such as isononyl alcohol or a water-miscible organic solvent such as tetrahydrofuran, for example, polyvinyl alcohol, and a partially acetalized product thereof, and a cation-modified product thereof such as a quaternary ammonium salt; Derivatives such as anion-modified products thereof with sodium sulfonate, polypinylpyrrolidone, polyethylene oxide, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, gelatin, gum arabic, methylvinylether-maleic anhydride copolymer, polyacryl Partially saponified acid esters, carboxyl group-containing compounds such as unsaturated carboxylic acids such as vinylpyrrolidone, (meth) acrylic acid, and itaconic acid and derivatives thereof, hydroxyethyl ( Data) copolymers of copolymerizable components a hydroxyl group-containing compounds such as acrylamide and the like.

Among them, polyvinyl alcohol and its derivatives are preferred from the viewpoint of oxygen barrier properties and the like, and the degree of saponification is 70 to 99 mol%, more preferably 85 to 95 mol%.
Preferably, the weight average molecular weight is 0.2 to 500,000, more preferably 0.4 to 100,000.

Further, from the viewpoint of adhesion to the photosensitive layer, vinylpyrrolidone polymers such as polyvinylpyrrolidone and vinylpyrrolidone-vinyl acetate copolymer, acrylic polymer emulsions, diisocyanate compounds, p-toluenesulfonic acid, It is preferable to contain hydroxyacetic acid and the like, and it is preferable to contain these in an amount of 0.1 to 60 parts by weight, more preferably 1 to 50 parts by weight, based on 100 parts by weight of the polyvinyl alcohol and its derivative.

Further, from the viewpoint of imparting preservability, it is preferable to contain an organic acid such as succinic acid or an organic acid salt such as ethylenediaminetetraacetic acid. Nonionics such as phenyl ether, anionics such as sodium dodecylbenzenesulfonate, cationic surfactants such as alkyltrimethylammonium chloride, and other defoaming agents, dyes, plasticizers, pH adjusters, etc. It may be contained in a proportion of 10 parts by weight or less based on 100 parts by weight of the alcohol and its derivative.

The oxygen barrier layer is formed as a solution of water or a mixed solvent of water and a water-miscible organic solvent by the same coating method as that for the above-described photosensitive layer. Usually 1 to 10 g / m ² , preferably 1.5 to
The range is 7 g / m ² .

In the image forming method of the present invention, the photopolymerizable image forming material is exposed, developed, and, if necessary, further heated or post-exposed. As the exposure, there is a method of irradiating a carbon arc lamp, a mercury lamp, a metallohalide lamp, a xenon lamp, a tungsten lamp, or the like through the original image. In the present invention, scanning exposure using laser light is preferable.

As the laser exposure light source, for example,
Helium cadmium laser, argon ion laser, FD-YAG laser, helium neon laser,
A semiconductor laser, a YAG laser, a ruby laser, or the like is used. Specifically, a semiconductor laser in a blue-violet region with a wavelength of about 390 to 430 nm, an argon ion laser at about 488 nm, an FD-YAG laser at about 532 nm, and a 700 to 1300 nm Semiconductor laser and YAG
Laser and the like. Laser exposure is varies appropriate value by the laser light source and plotter models which use, for example, a semiconductor laser of blue-violet region having a wavelength of 390~430nm is 0.5~100μJ / cm ^2, 488
5 to 500 μJ / cm ² , 7 for an argon ion laser near 532 nm and an FD-YAG laser near 532 nm.
0.5 to 20 for a semiconductor laser of 00 to 1300 nm
About 0 mJ / cm ² is preferable. Conventionally, after the laser exposure, a step of stabilizing the latent image by heating at a temperature in the range of 40 to 300 ° C., particularly about 100 ° C., has often been adopted. In the present invention, the support and the photosensitive layer are used. Since the adhesiveness to the film is good, it is possible to directly enter the next development step without performing such heat treatment. One of the features of the present invention is that the process is simplified and contributes to productivity.

In the processing method of the present invention, after the photosensitive lithographic printing plate has been subjected to image exposure with such a laser exposure machine, the protective layer may be washed with water before development to remove all or most of the protective layer. Good. The method of washing with water is not particularly limited, but specifically, a method of dissolving by immersing in water, a method of dissolving and removing by spraying water in a shower, and a method of removing a brush in a state of being immersed or sprayed with water. And the like. The washing temperature is usually 4 to 70
° C, preferably 10 to 50 ° C, more preferably 15 to 3 ° C.
0 ° C., and the washing time is about 1 second to 5 minutes, depending on the washing method. The washing water may contain a surfactant and a water-miscible organic solvent, if necessary.

Examples of the developing solution include sodium silicate, potassium silicate, lithium silicate, ammonium silicate, sodium metasilicate, potassium metasilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, and the like. Inorganic alkali salts such as sodium bicarbonate, potassium carbonate, sodium phosphate dibasic, sodium phosphate tribasic, ammonium phosphate dibasic, ammonium phosphate tribasic, sodium borate, potassium borate, ammonium borate, or monomethylamine, dimethylamine, trimethylamine , Monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, monobutylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diethylamine Alkali developer comprising an aqueous solution of about 0.1 to about 10% by weight of an organic amine compounds such as propanolamine is used.

For the purpose of improving the image quality and shortening the development time, the above-mentioned developer may contain, for example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl ester. , Sorbitan alkyl esters, monoglyceride alkyl esters, etc., nonionic, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfates, alkyl sulfonates, sulfosuccinate salts, etc., alkyl betaines, amino acids Amphoteric surfactants such as isopropyl alcohol, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, diacetone alcohol, etc. It is possible.

The development is usually performed by a known development method such as immersion development, spray development, brush development, or ultrasonic development.
Preferably about 10 to 60 ° C, more preferably 15 to 4 ° C.
This is performed at a temperature of about 5 ° C. for a time of about 5 seconds to about 10 minutes. At this time, the oxygen barrier layer may be removed in advance with water or the like, or may be removed during development.

[0087]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Examples 1 to 5 and Comparative Examples 1 to 5 The following ethylenically unsaturated compounds as component (A) and radicals as polymerization initiators as component (B) were formed on the surface of the following aluminum plate support: The coating thickness of the coating liquid of the photopolymerizable composition comprising a sensitizer, a sensitizer, a polymerization accelerator, a polymer binder of the component (C), and other components, and a solvent is adjusted to a dry film thickness of 2.
The composition was applied so as to be 0 g / m ² and dried at 70 ° C. for 2 minutes to form a photosensitive layer composed of the photopolymerizable composition. Further, a mixed aqueous solution of polyvinyl alcohol and polyvinyl pyrrolidone (polyvinyl alcohol: polyvinyl pyrrolidone = 70% by weight: 30% by weight) was further applied thereon using a bar coater so that the dry film thickness became 3 g / m ² , ° C
For 4 minutes to form an oxygen barrier layer, thereby preparing a photosensitive lithographic printing plate as a photopolymerizable image forming material. The lithographic printing plate thus prepared was evaluated for printing durability and chemical resistance according to the following.

Production of Support A raw aluminum sheet having a thickness of 0.24 mm was degreased with a 3% by weight aqueous solution of sodium hydroxide and then washed with water. Then, in a 18.0 g / liter nitric acid bath, 25 ° C., 90 A
A surface roughening treatment by electrolytic etching was performed at a current density of / dm ² for 11 seconds. After washing with water, it was immersed in a 4.5% by weight aqueous solution of sodium hydroxide at 30 ° C. for 5 seconds to be desmutted. After desmut treatment, wash with water
The solution was neutralized with a 10% by weight aqueous solution of nitric acid at 5 ° C. for 5 seconds and washed with water. Then, in a 30% by weight sulfuric acid bath, 30 ° C., 10 A /
Anodize at current density of dm ² for 16 seconds, wash with water,
After drying, an aluminum plate support was obtained.

(A) Ethylenically unsaturated compound Mixture of methacryloyloxyethyl phosphate and bis (methacryloyloxyethyl) phosphate of the following A1 (acid value 171); 11 parts by weight of hexamethylene bis [tris (acryloyloxymethyl) of the following A2 ) Ethyl urethane] (zero acid value); 22
Parts by weight 2,2-bis (4-acryloyloxydiethyleneoxyphenyl) propane of A3 below (acid value zero); 22
Parts by weight

[0091]

Embedded image

(B) Photopolymerization initiator (B-1) Radical generator dicyclopentadienyltitanium bis [2,6-difluoro-3- (1-pyrrolyl) phenyl]; 5 parts by weight

(B-2) Sensitizer Compound of the following D; 0.5 parts by weight Compound of the following E; 0.5 parts by weight

[0094]

Embedded image

(B-3) Polymerization accelerator 2-mercaptobenzothiazole; 5 parts by weight N-phenylglycine benzyl ester; 5 parts by weight

(C) Polymeric Binder (C1) 107 g of allyl methacrylate, 13 g of methacrylic acid, and ethanol as a reaction solvent were placed in a 3 liter four-necked flask equipped with a stir bar equipped with blades, a reflux condenser, and a nitrogen pipe. 6 liters were added and heated and stirred in a 90 ° C. oil bath. 1.6 g of azobisisobutyronitrile (AIBN) dissolved in 400 ml of ethanol was added to this solution. After heating and stirring for 3 hours, remove the nitrogen piping,
0.04 g of p-methoxyphenol and 400 ml of propylene glycol monomethyl ether acetate (PGM-AC) were added, the bath temperature was raised to 100 ° C, and heating and stirring were continued for 1 hour. Finally, ethanol was distilled off to obtain a 20% by weight solution of the copolymer. The weight average molecular weight of the copolymer was 180,000 and the acid value was 71.

(C1) 67 g of allyl methacrylate, 20 g of methyl methacrylate, 17 g of methacrylic acid and ethanol as a reaction solvent were placed in a three-liter four-necked flask equipped with a stir bar equipped with a blade, a reflux condenser and a nitrogen pipe.
6 liters were added and heated and stirred in a 90 ° C. oil bath. 1.6 g of AIBN dissolved in 400 ml of ethanol was added to this solution. After heating and stirring for 3 hours, the nitrogen pipe was removed, and 0.04 g of p-methoxyphenol, PGM
-400 ml of AC was added, the bath temperature was raised to 100 ° C, and heating and stirring were continued for 1 hour. Finally, ethanol was distilled off to obtain an 18% by weight solution of the copolymer. The weight average molecular weight of the copolymer was 140,000, and the acid value was 106.

(C1) 45 g of vinyl methacrylate, 60 g of 2-hydroxy-3-allyloxypropyl methacrylate, 8.0 g of acrylonitrile were placed in a 3 L four-necked flask equipped with a stirring rod with a blade, a reflux condenser, and a nitrogen tube.
13 g of methacrylic acid and 1.6 L of ethanol as a reaction solvent were added, and the mixture was heated and stirred in an oil bath at 80 ° C.
1.6 g of AIBN dissolved in 400 ml of ethanol was added to this solution. After heating and stirring for 3 hours, the nitrogen tube was removed, and 0.04 g of p-methoxyphenol and PGM-AC were removed.
400 ml was added, the bath temperature was raised to 100 ° C., and the heating and stirring were continued for 1 hour. Finally, ethanol was distilled off to obtain a 23% by weight solution of the ethylenic polymer binder. The weight average molecular weight of the copolymer was 230,000, and the acid value was 67. The obtained binder solution was diluted with PGM-AC and used as a 20% by weight solution.

(C1) 79 g of vinyl methacrylate, 8.0 g of acrylonitrile, 13 g of methacrylic acid, and 1.6 L of ethanol as a reaction solvent were placed in a 3 L four-necked flask equipped with a stirring rod with a blade, a reflux condenser, and a nitrogen tube. And heated and stirred in an oil bath at 80 ° C. A
1.6 g of IBN was dissolved in 400 ml of ethanol and added. After heating and stirring for 3 hours, the nitrogen tube was removed, 0.04 g of p-methoxyphenol and 400 ml of PGM-AC were added, the bath temperature was raised to 100 ° C, and heating and stirring were continued for 1 hour. Finally, ethanol was distilled off to obtain a 23% by weight solution of the ethylenic polymer binder. The weight average molecular weight of the copolymer was 150,000 and the acid value was 85. The obtained binder solution was diluted with PGM-AC and used as a 20% by weight solution.

(C2) A monomer mixture of ethyl acrylate / acrylonitrile / methacrylic acid / hydroxyphenyl methacrylamide = 60/20/10/10 (mol%) was prepared so that the monomer concentration of all monomers was 7.15 mol%. A solution of methanol / acetone = 1: 1 was prepared, AIBN was added to the solution in an amount equivalent to 1.25 mol% of the total monomer ratio, and the mixture was stirred in a vessel equipped with a stirring rod equipped with blades, a reflux condenser tube, and a nitrogen pipe. The mixture was refluxed at 65 ° C. for 6 hours under a nitrogen stream. After the reaction was completed, hydroquinone having a total monomer ratio of 0.04 mol was added, and the reaction solution was poured into water to precipitate a copolymer. This was collected by filtration and dried at 60 ° C. for 3 days. The weight average molecular weight of the obtained copolymer was 70,000, and the acid value was 58.

(C2) Copolymer of butyl acrylate / methyl methacrylate / methacrylic acid = 10/70/20 (mol%): weight average molecular weight: 60,000, acid value: 11
2. (C2) methyl methacrylate / methacrylic acid = 70
/ 30 (mol%) copolymer: weight average molecular weight is 10
10,000, acid value is 175.

Other component pigment (P.B. 15: 6); 4 parts by weight dispersant ("Disperbyk 161" manufactured by BYK Chemie);
2 parts by weight surfactant (“Emulgen 104P” manufactured by Kao Corporation); 2
Parts by weight surfactant ("S-381" manufactured by Asahi Glass Co., Ltd.); 0.3 parts by weight

Solvent Propylene glycol monomethyl ether acetate; 600 parts by weight cyclohexanone; 545 parts by weight

The obtained photosensitive lithographic printing plate was subjected to FD-YA
Using a G laser exposure machine (“Platejet” manufactured by Cybolic Science International), 2000 dpi, 6.8 m
Under the condition of W (exposure amount: 120 μJ / cm ² ), 2% flat knitting and 5% flat knitting were exposed. Then, potassium silicate 3
% By volume, sodium alkylnaphthalenesulfonate-based surfactant (concentration: 35% by weight, "Perex NB" manufactured by Kao Corporation)
L ") using an automatic developing machine (Western Litho Tech, Diamond
(Developer) at a developer temperature of 30 ° C. and a transport speed of 4 FPM.

Evaluation of lithographic printing plate Printing durability The obtained lithographic printing plate was printed with a printing machine (RP-R
1), and a printing durability test was performed. The printing durability was determined by a reproduction state of 2% of the image area after printing 30,000 sheets. ；: Reproducibility of 90% or more △: Reproducibility of 50% or more, less than 90% ×: Reproducibility of less than 50%

Chemical resistance The obtained lithographic printing plate was applied to a printing machine (RP-R
While printing over 1), the plate surface was wiped 10 times back and forth with a plate cleaner (Wiltra plate cleaner, manufactured by ABC Chemical Co.) every 2,000 sheets of 5% flat knitted parts,
A chemical resistance test was performed on the 10,000th plate. Chemical resistance was determined in a reproduction state of 5% after printing 10,000 sheets. ；: Reproducibility of 90% or more △: Reproducibility of 50% or more, less than 90% ×: Reproducibility of less than 50%

Table 1 summarizes the formulation and evaluation results of the polymer binder for each of the examples and comparative examples. The parts by weight of the polymer binder indicate the net weight of the solid content of the copolymer and does not include the solvent. The photosensitive lithographic printing plates of Examples 1 to 5 in which (C1) and (C2) are used in combination as the polymer binder are excellent in both printing durability and chemical resistance. on the other hand,
In the case of only (C1) (Comparative Examples 1, 2, and 5), although the chemical resistance is good, there is a problem in printing durability. In addition, when only (C2) was used (Comparative Examples 3 and 4), although the printing durability was good, there was a problem in the chemical resistance.

[0108]

[Table 1]

[0109]

According to the present invention, a photosensitive lithographic printing plate having excellent adhesion between a support and a photosensitive layer and excellent chemical resistance and printing durability can be obtained. Particularly, an image obtained by scanning exposure with laser light can be given sufficient image intensity and printing durability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/027 G03F 7/027 7/028 7/028 7/038 501 7/038 501 F term (reference) 2H025 AA06 AA07 AA08 AA12 AA14 AB03 AC08 AD01 BC03 BC19 BC32. AA05 AA07 BA04 CA05 CA08 DA02 DA04 FA07 FB01 PA69 PB40 PC02 QA02 QA03 QA05 QA06 QA07 QA12 QA13 QA14 QA21 QA22 QA26 QA42 QB19 SA73 SA76 SA78 SA85 SA87 SA90 UA02 VA01 WA01 4J026 AA43 AA02 AA43 AA42 AA42 AA42 AA45 AA42 AA42 AA45 AA45 AA45 AA42 AA45 AA45 AA45 AA42 AA45 DB36 FA05 GA06 GA07 GA08 GA10

Claims (13)

[Claims] A photosensitive lithographic printing plate having a photopolymerizable photosensitive layer containing an ethylenically unsaturated compound, a photopolymerization initiation system, and a polymer binder on a support, wherein the polymer binder is: A photosensitive lithographic printing plate comprising at least the following polymer binder (C1) and polymer binder (C2). Polymer binder (C1): General formula (1) (Wherein, R ^{3 to} R ⁷ 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, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an alkylamino group which may have a substituent, Alkylsulfonyl group which may have a substituent, aryl group which may have a substituent, aryloxy group which may have a substituent, arylamino group which may have a substituent Or an arylsulfonyl group which may have a substituent;
Represents an oxygen atom, a sulfur atom, an imino group, or an alkylimino group. ) Or the general formula (2) (Wherein, R ^{3 to} R ⁵ and Z Indicates the same as above. And at least one polymerizable unsaturated group represented by the general formula (3): (Wherein R ⁰ independently represents a hydrogen atom or a methyl group, and Z ⁰ represents an oxygen atom or an imino group.) One or more polymerizable unsaturated groups represented by the following formula: A copolymer having a monomer having a bond as a copolymer component, a polymer binder (C2): General formula (4) (Wherein, R ¹ is an alkyl group having 1 to 15 carbon atoms, R ² is a hydrogen atom or a methyl group, R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkylamino group,
Carboxyl group, alkoxycarbonyl group, sulfo group,
A nitro group, a cyano group, an optionally substituted alkyl group, and an optionally substituted alkylsulfonyl group, Indicates the same as above. A) a copolymer having a monomer having one unsaturated group represented by the formula (1) as a copolymer component. 2. A monomer having a polymerizable unsaturated group represented by the general formula (1) and a polymerizable unsaturated group represented by the general formula (3) is allyl (meth) acrylate, 3-allyloxy-2- Hydroxypropyl (meth) acrylate, N
-Allyl (meth) acrylamide, cinnamyl (meth)
Acrylate, crotonyl (meth) acrylate, methallyl (meth) acrylate, allyl crotonate and 3
2. The photosensitive lithographic printing plate according to claim 1, which is at least one member selected from the group consisting of -allyloxy-2-hydroxypropylcrotonate. 3. A monomer having a polymerizable unsaturated group represented by the general formula (2) and a polymerizable unsaturated group represented by the general formula (3), wherein vinyl (meth) acrylate, vinyl crotonate, 1- It is at least one selected from propenyl (meth) acrylate, 1-chlorovinyl (meth) acrylate, 2-phenylvinyl (meth) acrylate, vinyl (meth) acrylamide, 1-chlorovinylcrotonate and 1-propenylcrotonate. The photosensitive lithographic printing plate according to claim 1. 4. A compound having one polymerizable unsaturated group represented by the general formula (4), wherein methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, β-methyl methyl methacrylate, β-
The photosensitive lithographic printing plate according to claim 1, wherein the lithographic printing plate is at least one selected from ethyl methoxycarbonyl (meth) acrylate, N-butyl (meth) acrylamide, and octyl β-cyano (meth) acrylate. 5. A monomer having a polymerizable unsaturated group represented by the general formula (1) or (2) and a polymerizable unsaturated group represented by the general formula (3) is a polymer binder (C1 5) 10 to 90% by weight of the total monomers constituting the composition.
The photosensitive lithographic printing plate according to any one of the preceding claims. 6. The compound having a polymerizable unsaturated group represented by the general formula (4), which accounts for 5 to 95% by weight of all monomers constituting the polymer binder (C2). 1
A photosensitive lithographic printing plate according to the item. 7. The photosensitive lithographic printing plate according to claim 1, wherein the monomer constituting the polymer binder (C1) contains (meth) acrylic acid. 8. The photosensitive lithographic printing plate according to claim 1, wherein the monomer constituting the polymer binder (C2) contains (meth) acrylic acid. 9. The polymer binder (C1) having an acid value of 10 to 25.
9. The photosensitive lithographic printing plate according to claim 1, wherein the value is 0. 10. The polymer binder (C2) having an acid value of 10 to 2
The photosensitive lithographic printing plate according to any one of claims 1 to 9, wherein the number is 50. 11. The polymer binder (C1)
11. The composition according to claim 1, comprising 10 to 97% by weight and 3 to 90% by weight of a polymer binder (C2).
A photosensitive lithographic printing plate according to the item. 12. The polymer binder (C1) has the general formula (1)
(Meth) acrylate having a polymerizable unsaturated group represented by formula (1), (meth) acrylate having a polymerizable unsaturated group represented by formula (2), and an unsaturated carboxylic acid monomer, and if necessary, other polymerization. The photosensitive lithographic printing plate according to any one of claims 1 to 11, wherein the lithographic printing plate is a terpolymer or higher copolymer with a functional monomer. 13. An image forming method, comprising subjecting the photosensitive lithographic printing plate according to claim 1 to laser exposure.