JP2002214790A - Substrate for photosensitive planographic printing plate, photosensitive planographic printing plate and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the adhesiveness of a photosensitive layer to a substrate in a planographic printing plate with the photosensitive layer on the surface of the substrate, to improve the developability and printing resistance of the planographic printing plate and to particularly provide a planographic printing plate in which satisfactory image strength and printing resistance are imparted to an image obtained by scanning exposure with laser light. SOLUTION: In the substrate for a photosensitive planographic printing plate obtained by surface-roughening and anodically oxidizing an aluminum plate, desmutting treatment is carried out between the surface roughening and the anodic oxidation, and when reflection density immediately after the surface roughening step is represented by A and that immediately before the anodic oxidation step by B, the formula A-B<=0.10 is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photosensitive lithographic printing plate. More specifically, the present invention relates to an improvement of 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. .

[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. .

[0005] As an attempt to improve the adhesion between the photosensitive layer and the support, the support is roughened by mechanical, chemical, or electrochemical means, followed by chemical etching, anodic oxidation, chemical conversion, and hydrophilic treatment. There has been proposed a method of combining various treatments such as a chemical treatment, a sealing treatment, and a primer coating treatment. Conventionally, in a lithographic printing plate of the type widely used for exposing ordinary light through an original image, a method of controlling the surface condition of the support by adjusting the surface roughness or the depth of the rough surface to a predetermined range is known. Are known. For example, JP-A-55-13
No. 2294 specifies the average depth using a stylus-type surface roughness meter, and Canadian Patent No. 954449 specifies the height and diameter of the peak of the rough surface. However, simply controlling such surface roughness only allows the entire support to be grasped macroscopically and cannot reflect the fine state of individual locations, contributing to obtaining sufficient adhesiveness. Can not do it.

[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. With the goal. In particular, an object of the present invention is to provide a lithographic printing plate that provides an image obtained by scanning exposure with a laser beam with sufficient image strength and printing durability.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have controlled the desmutting treatment of roughened aluminum under specific conditions and set the surface of the aluminum support in a specific state. It has been found that the above object can be achieved by holding the above, and the present invention has been completed. That is, the present invention provides a photosensitive lithographic printing plate support obtained by subjecting an aluminum plate to a surface roughening and then performing an anodizing treatment, wherein there is a desmutting treatment between the roughening treatment and the anodizing treatment, When the reflection density immediately after the anodizing treatment step is A and the reflection density immediately before the anodizing treatment step is B, AB ≦ 0.1
The present invention provides a photosensitive lithographic printing plate support characterized by satisfying 0.

[0008]

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 is defined as:
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-hexamethylene triisocyanate, 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.

The epoxy (meth) acrylates include, for example, (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.

[0017]

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[In the formulas (Ia) and (Ib), R ¹ represents a hydrogen atom or a methyl group, n is an integer of 1 to 25, and 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, the (meth) acryloyloxy group described above is used as the ethylenically unsaturated compound as the component (A) from the viewpoints of exposure sensitivity, printing durability, and developability as a photosensitive layer. 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 a sensitizer for activating the radical generator upon irradiation with actinic rays to effectively generate an active radical, a sensitizer particularly sensitive to the visible light region is 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 dyes disclosed in JP-A-5885 and JP-A-10-144242. 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).

[0026]

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[In the formula (II), R ² represents a hydrogen atom or an alkyl group which may have a substituent; R ³ 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 an aromatic heterocyclic group which may have a substituent, wherein the benzene ring may have a substituent, and p is an integer of 2 to 10. ]

Here, examples of the substituent on 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.

In the present invention, as the polymer binder as the component (C) of the photopolymerizable composition constituting the photosensitive layer, for example, (meth) acrylic acid, (meth) acrylic ester, (meth) acrylate Homopolymers or copolymers such as acrylonitrile, (meth) acrylamide, maleic acid, styrene, vinyl acetate, vinylidene chloride, and maleimide, as well as polyamide, polyester, polyether, polyurethane, polyvinyl butyral, polyvinyl pyrrolidone, polyethylene oxide, and acetyl Cellulose and the like can be mentioned, and among them, a carboxyl group-containing polymer is preferred from the viewpoint of alkali developability, and specifically, (meth) acrylic acid and alkyl (meth) acrylate (having 1 to 10 carbon atoms). ) Copolymers containing ester or styrene as a copolymer component Preferably, the acid value of the carboxyl group-containing polymer is 10 to 250, weight average molecular weight is preferably 0.5 to 100 to 250,000. In addition, JP
Those having a carboxyl group and an unsaturated bond described in JP-A-312055 are also preferable.

As the polymer binder, those having an ethylenically unsaturated bond in the side chain are preferable, and as the ethylenically unsaturated bond, the following general formulas (IIIa), (IIIb),
Or those represented by (IIIc) are preferred.

[0031]

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[In the formulas (IIIa), (IIIb) and (IIIc), R^Four
Represents a hydrogen atom or a methyl group; ^Five, R⁶, R⁷, R
⁸, And R⁹Are each independently a hydrogen atom, a halogen atom
Child, amino group, dialkylamino group, carboxyl group,
Alkoxycarbonyl group, sulfo group, nitro group, cyano
Group, an alkyl group which may have a substituent,
Optionally having an alkoxy group or a substituent
Alkylamino groups and optionally substituted alkyl
Rusulfonyl group, aryl which may have a substituent
Group, aryloxy group which may have a substituent, substitution
An arylamino group which may have a group or a substituent
Represents an arylsulfonyl group which may have
Oxygen atom, sulfur atom, imino group, or alkylimino
Represents a group. ]

Here, an alkyl group for R ^{5 to} R ⁹ ,
Examples of the substituent of the alkoxy group, the alkylamino group, the alkylsulfonyl group, the aryl group, the aryloxy group, the arylamino group, and the arylsulfonyl group include, for example,
Examples thereof include an alkyl group, an alkoxy group, an alkylthio group, an amino group, a dialkylamino group, a nitro group, a cyano group, a phenyl meaning, and a halogen atom.

The polymer binder having an ethylenically unsaturated bond in the side chain represented by the formula (IIIa) is obtained by adding a carboxyl group-containing polymer to allyl glycidyl ether, glycidyl (meth) acrylate, α-ethyl glycidyl ( Meta)
Acrylate, glycidyl crotonate, glycidyl isocrotonate, crotonyl glycidyl ether, monoalkyl monoglycidyl itaconate, monoalkyl monoglycidyl fumarate, monoalkyl monoglycidyl maleate and other unsaturated compounds containing an aliphatic epoxy group, Alternatively, an alicyclic epoxy group-containing unsaturated compound such as 3,4-epoxycyclohexylmethyl (meth) acrylate may be used at a temperature of about 80 to 120 ° C.,
In about 50 to 50 hours, 5 to 90 mol%, preferably 3 to 90 mol% of the carboxyl groups of the carboxyl group-containing polymer.
It is obtained by reacting about 0 to 70 mol%.

The polymer binder having an ethylenically unsaturated bond represented by the formula (IIIb) in the side chain includes allyl (meth) acrylate, 3-allyloxy-2-hydroxypropyl (meth) acrylate, cinnamyl (meth) A) a compound having two or more unsaturated groups such as acrylate, crotonyl (meth) acrylate, methallyl (meth) acrylate, N, N-diallyl (meth) acrylamide, and an unsaturated carboxylic acid such as (meth) acrylic acid; Alternatively, it can be obtained by copolymerizing with an unsaturated carboxylic acid ester such that the ratio of the former compound having an unsaturated group to the whole is 10 to 90 mol%, preferably about 30 to 80 mol%. Similarly, polymer binders having an ethylenically unsaturated bond represented by the formula (IIIc) in the side chain include allyl (meth) acrylate, 3-allyloxy-2-hydroxypropyl (meth) acrylate, cinnamyl (meth) ) Acrylate, crotonyl (meth) acrylate,
A compound having two or more types of unsaturated groups such as methallyl (meth) acrylate and N, N-diallyl (meth) acrylamide, and an unsaturated carboxylic acid such as (meth) acrylic acid or further unsaturated carboxylic acid ester It is obtained by copolymerization so that the ratio of the former compound having an unsaturated group to the whole becomes 10 to 90 mol%, preferably about 30 to 80 mol%.

In the present invention, the contents 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 usually 10-4
00 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 or tricresyl phosphate, and sensitivity characteristics of a tertiary amine or 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 producing 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.

Prior to the formation of the photosensitive layer comprising the photopolymerizable composition on the surface of the aluminum plate support, usually, a degreasing treatment, a roughening treatment (graining treatment), a desmutting treatment, an anodizing treatment, What has been subjected to a sealing treatment, an undercoating treatment and the like is used. The present invention is characterized by this desmutting treatment. The method for producing the support will be described below in order.

Here, the degreasing treatment includes a method of wiping using a solvent, immersing or steam cleaning, a method of immersing or spraying with an alkaline aqueous 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 etching agent include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and oxalic acid. Examples of the alkaline etching agent 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.

This desmutting treatment is performed to remove the smut on the surface of the support caused by the roughening treatment. The present inventors have found that the smut removed by this desmutting treatment is actually greatly involved in the adhesion between the support and the photosensitive layer. In particular, the photopolymerizable photosensitive layer, which is generally exposed to a laser with poor adhesion to the photosensitive layer, has a sensitive effect, so it has good conditions, that is, a range that does not cause adverse effects such as developability and contamination during printing. It is very effective to leave the smut. In addition, it was confirmed that the desmutting treatment removed the smut and etched the surface of the support at the same time as removing the smut, which also affected the adhesion to the photosensitive layer.

That is, the feature of the present invention is that by controlling the desmut treatment under specific conditions, the adhesiveness between the photosensitive layer and the support is ensured while sufficiently maintaining the developability and the hydrophilicity required during printing. Is to do. Conventionally, the processing has been performed in a direction to remove the smut as completely as possible, but this is to be suppressed so as to partially satisfy a specific condition. Assuming that the reflection density immediately after the surface roughening step is A and the reflection density immediately before the anodizing step is B,
This is to keep the difference in reflection density within a specific range. That is, AB ≦ 0.10, preferably 0.03 ≦ AB
≤ 0.08. If no desmut treatment is performed, a large amount of smut remains on the process line as it is, which has an adverse effect. That is, since the photosensitive layer cannot be sufficiently developed in terms of performance and causes stains during printing, desmutting is indispensable. still,
The reflection density is measured using a reflection densitometer in a visual mode without filtering.

When the surface is roughened by electrolytic etching in a hydrochloric acid or nitric acid electrolytic solution, an alkali is used in a subsequent neutralization step, and etching may proceed depending on conditions. However, the change in the reflection density of the support surface during the neutralization step is substantially close to zero. Similarly, after the desmutting treatment, a neutralization step and a washing step are performed, followed by an anodic oxidation step, but the reflection density does not substantially change in the neutralization and washing step. Therefore, in the desmut treatment of the present invention, before and after the treatment, the reflection density is reduced by 0.01 to 0.1.
It can also be expressed as controlling to be 0, preferably in the range of 0.03 to 0.08.

The desmutting process of the present invention results in
AB ≦ 0.10, preferably 0.03 ≦ AB ≦
0.08, and more directly, before and after desmutting, the reflection density is reduced by 0.01 to
It is to control so as to be in the range of 0.10, preferably 0.03 to 0.08. Specific conditions of the desmut treatment, depending on the type of acid or alkali aqueous solution used as a desmut treatment agent, depending on the state of the surface roughening treatment, for example,
Conditions include immersion in an aqueous solution of sodium hydroxide having a concentration of 1 to 4% by weight and a liquid temperature of about 0 to 40 ° C. for about 1 to 10 seconds. Preferably, a method of immersing in a sodium hydroxide aqueous solution of 0.3 to 3% by weight at a liquid temperature of 5 to 30 ° C. for 1 to 5 seconds 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 used for applying the photopolymerizable composition solution to 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 is, 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 for preventing the photopolymerizable composition from inhibiting polymerization 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 preferable from the viewpoint of oxygen barrier property 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 adhesiveness to the photosensitive layer, vinylpyrrolidone-based 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 photosensitive layer described above. 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. The appropriate amount of laser exposure varies depending on the type of laser light source or plotter used. For example, in the case of a semiconductor laser in the blue-violet region of 390 to 430 nm, 0.5 to 100 μJ / cm ² , an argon ion laser near 488 nm and an argon ion laser near 532 nm are used. FD-
5 ~ 500μJ / cm ² , 700 ~
0.5-200mJ for 1300nm semiconductor laser
/ Cm ² is preferred. Conventionally, after laser exposure, 40
In many cases, a step of stabilizing the latent image by performing a heat treatment in a temperature range of from about 300 ° C. to about 100 ° C. is often adopted. However, in the present invention, the adhesion between the support and the photosensitive layer is good. Therefore, 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 is 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, for example, sodium silicate, potassium silicate, lithium silicate, ammonium silicate, sodium metasilicate, potassium metasilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, Inorganic alkali salts such as sodium bicarbonate, potassium carbonate, sodium diphosphate, sodium tertiary phosphate, ammonium diphosphate, ammonium tertiary phosphate, 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, shortening the development time, etc., the developing solution 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 pH of the developer is
It is preferably 9 to 14.

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.

[0068]

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.

Example 1 The following ethylenically unsaturated component (A) was coated on the surface of the following aluminum plate support:
A coating solution of a photopolymerizable composition comprising a radical generator as a polymerization initiator of the component (B), a sensitizer, a polymerization accelerator, a polymer binder of the component (C), and other components, and a solvent is used. dry film thickness using. the coating is 2.0 g / m ^2, to form a photosensitive layer comprising a photopolymerizable composition was dried for 2 minutes at 70 ° C.. Further, a mixed aqueous solution of polyvinyl alcohol and polyvinylpyrrolidone (polyvinyl alcohol: polyvinylpyrrolidone = 70% by weight: 30% by weight) was further dried thereon by using a bar coater to have a dry film thickness of 3%.
g / m ² and dried at 70 ° C. for 4 minutes to form an oxygen barrier layer, thereby producing a photosensitive lithographic printing plate as a photopolymerizable image forming material.

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, at 25 ° C. and 87 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 2 seconds to perform a desmut treatment. 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. Physical properties of support (1) Surface reflection density (Macbeth densitometer, manufactured by Macbeth
The surface reflection density of the aluminum plate was 0.40 immediately after the surface roughening treatment (A), and 0.35 immediately after the desmutting treatment and immediately before the anodizing treatment (B) (measured by RD-918). (2) Residual amount of smut After the desmutting process and immediately before the anodizing treatment, the weight of the smut remaining on the aluminum plate was measured.
It was 0.1 g / m ² . The residual amount of smut was determined using a 10 cm square aluminum plate sample at 93 ° C. smut solution (phosphoric acid 35 mL, chromic acid 20 g / L).
Expressed in elution volume when immersed for 5 minutes (g / m ²⁾ on. (3) Surface average roughness of the aluminum plate support (Ra)
Was measured according to JIS B0601 and found to be 0.6
μm. Table 1 summarizes the results of the production conditions and surface properties of the support.

(A) Ethylenically unsaturated compound Mixture of methacryloyloxyethyl phosphate and bis (methacryloyloxyethyl) phosphate of the following A; 11 parts by weight of hexamethylene bis [tris (acryloyloxymethyl) ethyl urethane of the following B]; 22 parts by weight 2,2-bis (4-acryloyloxydiethyleneoxyphenyl) propane of the following C; 22 parts by weight

[0072]

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(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

[0075]

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

(C) Polymer binder Methyl methacrylate (80 mol%) / methacrylic acid (20 mol%) copolymer (weight average molecular weight: 50,000)
Reaction product obtained by reacting 3,4-epoxycyclohexylmethyl acrylate (acid value 53, 50 mol% of carboxyl groups of methacrylic acid component react); 45 parts by weight

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 a condition of W (exposure amount: 120 μJ / cm ² ), 2% flat knitting was exposed. Then, potassium silicate 3% by volume, sodium alkylnaphthalenesulfonate-based surfactant (concentration 3
5% by weight, Kao Corporation "Perex NBL") 5% by volume,
An automatic developing machine (We
Development processing was performed using a Diamond Processer (stern Litho Tech) at a developer temperature of 30 ° C. and a transport speed of 4 FPM.
The state of the plate after development was determined according to the following criteria. Table 1 shows the results
It was shown to. ；: Good development △: dye remaining ×: photosensitive layer in non-image area remains

The planographic printing plate obtained by making a plate in this manner was set on a printing machine (RP-1 manufactured by Roland) to perform a printing durability test. The printing durability was determined by a reproduction state of 2% of the image area after printing 30,000 sheets. The results are shown in Table 1. ；: Reproducibility of 90% or more △: Reproducibility of 50% or more, less than 90% ×: Reproducibility of less than 50%

[Examples 2 and 3, Comparative Examples 1 to 3]
, A lithographic printing plate was made in the same manner as in Example 1 except that the conditions of the desmutting treatment were changed as shown in Table 1. Table 1 summarizes the surface condition of the support (the remaining amount of smut and the reflection density) and the developability and printing durability of the obtained lithographic printing plate. As is clear from the examples and comparative examples, when desmutting is performed so that the change in reflection density exceeds 0.10, the printing durability of the lithographic printing plate support is inferior. On the other hand, when the desmut treatment is omitted, the developing property is poor,
In addition, printing becomes impossible due to dirt.

[0083]

[Table 1]

[0084]

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

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Teruo Takada 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsubishi Chemical Research Institute (72) Inventor Yasushi Sasaoka 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi F-term (reference) in Yokohama R & D Co., Ltd. BA01 BA10 DA04 DA43 DA50 DA51 DA52 DA53 DA56 DA58 DA60 EA01 EA03 EA09 FA10 GA05 GA06 GA08 GA09

Claims (11)

[Claims] A photosensitive lithographic printing plate support obtained by subjecting an aluminum plate to a surface roughening and then performing an anodizing treatment,
If there is a desmut treatment between the surface roughening treatment and the anodic oxidation treatment, and the reflection density immediately after the surface roughening treatment step is A and the reflection density immediately before the anodic oxidation treatment step is B, AB ≦ 0.10
A support for a photosensitive lithographic printing plate, characterized by satisfying the following. 2. When the reflection density immediately after the roughening treatment step is A and the reflection density immediately before the anodic oxidation treatment step is B, 0.03
2. The condition of <AB <0.08 is satisfied.
The support for the photosensitive lithographic printing plate as described above. 3. The support for a photosensitive lithographic printing plate according to claim 1, wherein the surface roughening treatment includes electrolytic etching with an acid. 4. The support for a photosensitive lithographic printing plate according to claim 1, wherein the desmut treatment uses an aqueous alkali solution. 5. The support for a photosensitive lithographic printing plate according to claim 4, wherein the aqueous alkali solution is a 0.5 to 3% by weight aqueous alkali hydroxide solution. 6. The support for a photosensitive lithographic printing plate according to claim 4, wherein the desmutting treatment is performed at 0 to 40 ° C. 7. A decrease in reflection density due to desmutting,
The photosensitive lithographic printing plate support according to any one of claims 4 to 6, wherein the support is 0.01 to 0.10. 8. The support for a photosensitive lithographic printing plate according to claim 1, wherein the smut remaining on the support after the desmut treatment is 0.1 to 0.5 g / m ² . 9. A photosensitive lithographic printing method comprising: providing a photosensitive layer containing an ethylenically unsaturated compound, a photopolymerization initiator system and a polymer binder on the support according to any one of claims 1 to 8. Edition. 10. The photosensitive lithographic printing plate according to claim 9, wherein the ethylenically unsaturated compound contains a phosphate having an acryloyloxy group or a methacryloyloxy group. 11. An image forming method, comprising subjecting the photosensitive lithographic printing plate according to claim 9 to laser exposure.