JPH11249298A - Photosensitive composition and photosensitive lithographic printing plate - Google Patents

Abstract

(57) [Problem] To provide a photosensitive composition excellent in sensitivity, printing durability, chemical resistance and storage stability, and a photosensitive lithographic printing plate using such a photosensitive composition. SOLUTION: An ethylenically unsaturated double bond-containing monomer, an alkaline water-soluble or swellable acidic vinyl copolymer,
A photosensitive composition containing a photopolymerization initiator. The photopolymerization initiator contains two or more triazine compounds represented by the following formula. A photosensitive lithographic printing plate comprising a photosensitive layer formed on a support surface-treated with the photosensitive composition. Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive composition and a photosensitive lithographic printing plate, and more particularly to a photosensitive composition having excellent sensitivity, printing durability, chemical resistance and storage stability, and this photosensitive composition. The present invention relates to a photosensitive lithographic printing plate manufactured using the composition.

[0002]

2. Description of the Related Art In general, a negative photosensitive lithographic printing plate is prepared by coating a photosensitive composition on a support such as an aluminum plate, irradiating active light such as ultraviolet light through a negative image, and irradiating the light-irradiated portion. Is polymerized or cross-linked to make it insoluble in the developing solution, and then, the non-irradiated portion is eluted in the developing solution, so that each portion repels water, receives an image portion that receives ink, and receives water. It is manufactured by using a non-image portion that repels ink.

Heretofore, as a photosensitive composition used for such a purpose, a photopolymerizable composition using a photopolymerization initiator is well known, and some of them are practically used. When any of the photosensitive compositions is used as a photosensitive layer of a lithographic printing plate, the plate needs to be replaced on the way due to wear of the plate,
There are problems such as deterioration of the image area due to the chemical used for wiping the plate surface.

In order to improve these problems, Japanese Patent Publication No.
Japanese Patent Publication No. 63740 / JP-B No. 6-105353 discloses the use of a binder having a crosslinkable group such as an allyl group or a vinyl group.

[0005]

By using such a binder, the problems of plate wear and deterioration due to chemicals can be improved, and higher sensitivity can be achieved, but further higher sensitivity is desired.

[0006] Further, the photosensitive lithographic printing plate using the above photopolymerizable composition has a disadvantage that the photopolymerization initiator is agglomerated due to storage over time and the printing performance is deteriorated.

The present invention solves the above-mentioned conventional problems, and provides a photosensitive composition excellent in sensitivity, printing durability, chemical resistance and storage stability, and photosensitive lithographic printing using the photosensitive composition. The purpose is to provide a version.

[0008]

Means for Solving the Problems The photosensitive composition of the present invention comprises an ethylenically unsaturated double bond-containing monomer, an alkali water-soluble or swellable acidic vinyl copolymer, and a photopolymerization initiator. Wherein the photopolymerization initiator comprises two or more triazine compounds represented by the following general formula.

[0009]

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Wherein R ¹ is a substituted or unsubstituted aliphatic or aromatic group, and R ² and R ³ independently represent a haloalkyl group. When two or more specific triazine compounds are used in combination, sensitivity, printing durability, and chemical resistance are improved, and aggregation of the photopolymerization initiator is suppressed, and storage stability is improved.

In the present invention, the alkaline water-soluble or swellable acidic vinyl copolymer preferably has an unsaturated group in a side chain, and the unsaturated group in the side chain is an allyl group and / or a vinyl group. Is preferred.

Further, the photosensitive composition of the present invention further comprises a diazo resin, in particular, a co-condensation compound containing, as constituent units, an aromatic compound residue having a carboxyl group and / or a hydroxyl group and an aromatic diazonium compound residue. It is preferable to contain a diazo resin consisting of

The photosensitive lithographic printing plate of the present invention is obtained by forming a photosensitive layer on a support surface-treated with such a photosensitive composition of the present invention.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

In the photosensitive composition of the present invention, an ethylenically unsaturated double bond-containing monomer (hereinafter abbreviated as "ethylenic monomer") contained as a first essential component is a photosensitive composition. It is a monomer having an ethylenically unsaturated double bond that undergoes addition polymerization and cures by the action of a photopolymerization initiator, which is the third essential component, when the product is irradiated with actinic rays. Incidentally, the meaning of the monomer in the present invention,
This is a concept corresponding to a so-called polymer, and therefore includes not only monomers in a narrow sense but also dimers, trimers and oligomers.

As the ethylenic monomer, it is desirable to use a polyfunctional ethylenic compound having two or more ethylenically unsaturated double bonds in one molecule. Esters of aliphatic polyhydroxy compounds with unsaturated carboxylic acids; esters of aromatic polyhydroxy compounds with unsaturated carboxylic acids; polyhydroxy compounds such as aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds with unsaturated Esters obtained by an esterification reaction with a carboxylic acid and a polycarboxylic acid are exemplified.

The ester of the aliphatic polyhydroxy compound and the unsaturated carboxylic acid is not particularly limited,
For example, ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol Acrylic esters of aliphatic polyhydroxy compounds such as pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, and glycerol acrylate; methacrylic esters in which the acrylate of these exemplified compounds is replaced with methacrylate; and itacone in which likewise itaconate is replaced Crotonic acid instead of acid ester and clonate Maleic acid esters in which instead of the ester or maleate and the like.

The ester of the aromatic polyhydroxy compound and the unsaturated carboxylic acid is not particularly limited, but examples thereof include aromatic polyhydroxy compounds such as hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate, and pyrogallol triacrylate. And methacrylic acid esters.

The ester obtained by the esterification reaction of the unsaturated carboxylic acid, the polycarboxylic acid and the polyhydroxy compound is not particularly limited, but typical examples include acrylic acid, phthalic acid and ethylene glycol. Condensate of acrylic acid, maleic acid, and condensate of methylene glycol, methacrylic acid, condensate of terephthalic acid and pentaerythritol, acrylic acid,
And condensates of adipic acid, butanediol and glycerin.

Other examples of the polyfunctional ethylenic monomer used in the present invention include a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate or a polyisocyanate compound with a polyol and a hydroxyl group-containing (meth) acrylate. Urethane (meth) acrylates obtained by the reaction; epoxy acrylates such as an addition reaction product of a polyvalent epoxy compound and hydroxy (meth) acrylate or (meth) acrylic acid; acrylamides such as ethylenebisacrylamide; Allyl esters such as diallyl phthalate; vinyl-containing compounds such as divinyl phthalate are useful.

Such an ethylenic monomer is preferably contained in the solid content of the photosensitive composition in an amount of 5 to 70% by weight, particularly 10 to 60% by weight.

Next, the alkaline water-soluble or swellable acidic vinyl copolymer which is the second essential component of the present invention will be described. Specific examples of this vinyl copolymer include, for example,
(Meth) acrylic acid, (meth) acrylic acid ester,
(Meth) acrylamide, maleic acid, (meth) acrylonitrile, styrene, vinyl acetate, vinylidene chloride,
Examples thereof include homo- or copolymers of maleimide and the like, polyethylene oxide, polyvinyl pyrrolidone, polyamide, polyurethane, polyester, polyether, polyethylene terephthalate, acetyl cellulose, and polyvinyl butyral. Among them, a copolymer containing at least one (meth) acrylic acid ester and (meth) acrylic acid as a copolymer component is preferable. The preferred acid value of the molecular vinyl copolymer is 10 to 250, and the preferred weight average molecular weight (hereinafter abbreviated as Mw) is 5,000 to 1,000,000.

It is desirable that these vinyl copolymers have an unsaturated bond in a side chain, and particularly, the following general formulas (1) to (1).
It is preferable to have at least one type of unsaturated bond represented by (3) from the viewpoint of improving printing durability and chemical resistance.

[0024]

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(Wherein, R ^{11 to} R ¹⁵ may each independently have a hydrogen atom, a halogen atom, an amino group, an amide group, a carboxyl group, a sulfo group, a nitro group, a cyano group, or a substituent. Alkyl group, aryl group which may have a substituent, alkoxy group which may have a substituent, aryloxy group which may have a substituent, alkyl which may have a substituent An amino group, an arylamino group optionally having a substituent, an alkylsulfonyl group optionally having a substituent, or an arylsulfonyl group optionally having a substituent, Z is an oxygen atom, It represents a sulfur atom, an imino group, or an alkylimino group.) As a method for synthesizing such a vinyl copolymer, there are roughly the following two methods.

(Synthesis Method 1) An inert organic solvent solution of a polymer binder having a carboxyl group in the molecule (for example, alcohol-based, ester-based, aromatic hydrocarbon-based, aliphatic hydrocarbon-based, etc.) A method of reacting an unsaturated compound having an epoxy group with an epoxy group under a reaction condition of about 80 to 120 ° C. for about 1 to 50 hours. The ratio of the carboxyl group to be reacted with the epoxy group-containing unsaturated compound is not particularly limited as long as the effect of the present invention can be achieved, but it is preferable to react 5 to 90 mol% with respect to all the carboxyl groups. Preferably it is 20 to 80 mol%, more preferably 30 to 70 mol%. Within the above range, the developing property is good and the adhesive property is good.

The epoxy group-containing unsaturated compound used herein is a compound having at least one addition-polymerizable unsaturated bond and an epoxy group in one molecule.

Examples of the unsaturated compound having an epoxy group include glycidyl (meth) acrylate, allyl glycidyl ether, α-ethyl glycidyl acrylate, crotonyl glycidyl ether, glycidyl crotonate, glycidyl isocrotonate, monoalkyl itaconate monoglycidyl ester And aliphatic epoxy group-containing unsaturated compounds such as fumaric acid monoalkyl ester monoglycidyl ester and maleic acid monoalkyl ester monoglycidyl ester, and alicyclic epoxy group-containing unsaturated compound represented by the following structure.

[0029]

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[0030]

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(In each formula, R ²¹ represents a hydrogen atom or a methyl group. R ²² represents a divalent saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms. R ²³ has a 1 to 10 carbon atom.) It represents a divalent hydrocarbon group, and k represents an integer of 0 to 10.) Specific examples of preferred compounds of the epoxy group-containing unsaturated compound include glycidyl methacrylate, allyl glycidyl ether, and 3,4-epoxycyclohexyl. Methyl acrylate and the like can be mentioned. Particularly preferred compounds among these are allyl glycidyl ether, 3,4-
Epoxycyclohexylmethyl acrylate.

(Synthesis method 2) The above general formulas (2) and (3)
And at least one kind of unsaturated bond having low reactivity and one kind of unsaturated bond having higher reactivity than these.
A method of synthesizing a compound having at least one kind of unsaturated bond and an unsaturated carboxylic acid by copolymerization.

Specific examples of the compound having an unsaturated group represented by the general formula (2) include allyl (meth) acrylate, 3-allyloxy-2-hydroxypropyl (meth) acrylate, and N, N-diallyl (meth) acrylate. Acrylamide, cinnamyl (meth) acrylate, crotonyl (meth) acrylate, methallyl (meth) acrylate and the like can be mentioned.

Specific examples of the compound having an unsaturated group represented by the general formula (3) include vinyl (meth) acrylate, vinyl crotonate, 1-propenyl (meth) acrylate, 1-chlorovinyl (meth) acrylate, 2
-Phenyl vinyl (meth) acrylate, vinyl (meth) acrylamide and the like.

Among the compounds having the structures (2) and (3), preferable compounds include allyl methacrylate and vinyl methacrylate.

These monomers are copolymerized with an unsaturated carboxylic acid, preferably acrylic acid or methacrylic acid, to obtain a copolymer having the unsaturated group. As the monomer to be copolymerized, another monomer may be copolymerized in addition to the unsaturated carboxylic acid, and examples thereof include alkyl acrylate, alkyl methacrylate, acrylonitrile, and styrene. The ratio of the compound having the structure of (2) or (3) to the total components of the polymer to be copolymerized is preferably 10 to 90 mol%, more preferably 30 to 80 mol%. If the ratio is less than the above range, the image reproducibility is poor, and if the ratio is large, the developability deteriorates.

It is preferable that such an alkali water-soluble or swellable vinyl copolymer be contained in an amount of 30 to 95% by weight, particularly 40 to 90% by weight, based on the solid content of the photosensitive composition.

Next, the photopolymerization initiator, which is the third essential component of the photopolymerizable composition of the present invention, will be described.

In the present invention, at least two types of triazine compounds represented by the following general formula are used as a photopolymerization initiator.

[0040]

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(Where R¹Is a substituted or unsubstituted fat
An aliphatic group or an aromatic group,^TwoAnd R ^ThreeIs independently halo
Represents an alkyl group. The triazine compound used in the present invention is, in particular, one of the following:
It is preferably represented by a general formula.

[0042]

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Wherein R ^a represents a substituted or unsubstituted aromatic or heterocyclic group; R ^b and R ^c each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms;
Represents a chloro or bromo atom, and n represents an integer of 0 to 3. In the above general formula, the substituent of ^Ra is not particularly limited, but is preferably an alkyl group, a halogen atom, an alkoxy group, a nitro group, an acetyl group, an amino group, an alkylamino group, or the like.

^Ra is preferably a substituted or unsubstituted phenyl group or naphthyl group.

The following are preferred triazine compounds suitable for the present invention.

[0046]

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In the present invention, two or more of such triazine compounds are used in combination. The proportion of the triazine compound is 5 to 95% by weight based on the total amount of the triazine compound. It is particularly preferably from 10 to 90% by weight, particularly preferably from 20 to 80% by weight.

In the present invention, an initiator for initiating the polymerization of an ethylenic monomer can be used in combination with the above-mentioned triazine-based compound as a photopolymerization initiator, for example, benzoin, benzoin alkyl ether, benzophenone. , Anthraquinone-based compounds, Michler's ketone, oxadiazole-based compounds, biimidazole-based compounds, titanocene-based compounds, thioxanthone-based compounds, aromatic tertiary amines, and the like can all be suitably used. Specific examples of these photopolymerization initiators and preferable examples thereof are described in “UV / EB Curing Handbook-Raw Materials-” edited by Kato Kiyomi (Polymer Publishing Association), pp. 67-73, “UV / E
Application and Market of B-Curing Technology ", edited by Radotech Kenkyukai (CMC), supervised by Yoneho Tabata, pages 64-82,
No. 42074, JP-A-62-61044, JP-A-60-35725, and JP-A-2-287747.
And those described in Japanese Patent Application Laid-Open Publication No. H10-26095. Further, compounds capable of generating an acid upon irradiation with an actinic ray described in JP-A-4-362543 and JP-A-4-362644 can also be used as a photopolymerization initiator, but they can be used in the present invention. The photopolymerization initiator that can be produced is not limited to these specific examples.

The photopolymerization initiator in the present invention is used in an amount of 0.2 to 30% by weight, especially 0.5 to 30% by weight, based on the solid content of the photosensitive composition.
Preferably, the triazine compound is contained in an amount of 1 to 30% by weight in the solid content of the photosensitive composition.
%, Particularly preferably 2 to 20% by weight.

In the present invention, a diazo resin can be further added to the photosensitive composition for the purpose of imparting adhesiveness to the support of the photosensitive layer to be formed.

The diazo resin that can be used in the present invention includes:
Although it is optional, it is preferable to use a photosensitive compound having a structure represented by the following general formula (i) or (ii), and particularly preferably a compound represented by (ii).

[0052]

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(In the formula (i), R ³¹ represents a hydrogen atom, an alkyl group or a phenyl group, and R ³² , R ³³ and R ³⁴ represent
Each independently represents a hydrogen atom, an alkoxy group or an alkyl group, M represents a counter anion, Y represents -O-, -S-
Or -NH-. )

[0054]

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(In the formula (ii), R ³⁵ and R ³⁶ each independently represent a hydrogen atom, an alkyl group or a phenyl group;
R ³⁷ , R ³⁸ , and R ³⁹ each independently represent a hydrogen atom, an alkoxy group, or an alkyl group; M represents a counter anion; Y represents —O—, —S—, or —NH—; Represents an aromatic group. The ratio of p to q is preferably 10: 1 to 1
The ratio is 1:10, more preferably 5: 1 to 1: 5. In the above general formula (ii), specific examples of the aromatic compound that can be used to give the aromatic group represented by A include m-chlorobenzoic acid, diphenylacetic acid, phenoxyacetic acid, and p-methoxy. Phenylacetic acid, p-methoxybenzoic acid, 2,4-dimethoxybenzoic acid, 2,4-dimethylbenzoic acid, p-phenoxybenzoic acid, 4-anilinobenzoic acid, 4- (m-methoxyanilino) benzoic acid,
-(P-methylbenzoyl) benzoic acid, 4- (p-methylanilino) benzoic acid, phenol, (o, m, p)-
Cresol, xylenol, resorcinol, 2-methylresorcinol, (o, m, p) -methoxyphenol, m-
Methoxyphenol, catechol, phloroglucin, p
-Hydroxyethylphenol, naphthol, pyrogallol, hydroquinone, p-hydroxybenzyl alcohol, 4-chlororesorcin, biphenyl-4,4'-diol, 1,2,4-benzenetriol, bisphenol A, 2,4-dihydroxybenzophenone, 2,
3,4-trihydroxybenzophenone, p-hydroxyacetophenone, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylamine,
4,4′-dihydroxydiphenyl sulfide, cumylphenol, (o, m, p) -chlorophenol,
(O, m, p) -bromophenol, salicylic acid, p-
Hydroxybenzoic acid, 2-methyl-4-hydroxybenzoic acid, 6-methyl-4-hydroxybenzoic acid, 2,4-
Dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 4-chloro-2,6-dihydroxybenzoic acid, 4-
Methoxy-2,6-dihydroxybenzoic acid, gallic acid,
Phloroglucin carboxylic acid, p-hydroxyphenyl (meth) acrylamide, cinnamic acid, ethyl cinnamate, p-
Hydroxycinnamic acid, styrene, (o, p) -hydroxystyrene, stilbene, 4-hydroxystilbene, 4
-Carboxystilbene, 4,4'-dicarboxystilbene, diphenyl ether, diphenylamine, diphenylthioether, 4-methoxydiphenylether, 4-methoxydiphenylamine, 4-methoxydiphenylthioether and the like.

Of these, particularly preferred are p-hydroxybenzoic acid, p-methoxybenzoic acid, p-hydroxycinnamic acid, p-hydroxyphenyl (meth) acrylamide, diphenyl ether, 4-methoxydiphenyl ether and diphenylamine.

As the aromatic diazonium compound as a constituent unit of the diazo resin represented by the general formulas (i) and (ii), for example, a diazonium salt as described in JP-B-49-48001 can be used. Yes, but especially
Diphenylamine-4-diazonium salts are preferred.
Diphenylamine-4-diazonilium salts are derived from diphenylamines, and such 4-amino-diphenylamines include 4-aminodiphenylamine, 4-amino-3-methoxydiphenylamine,
4-amino-2-methoxydiphenylamine, 4'-amino-2-methoxydiphenylamine, 4'-amino-
4-methoxydiphenylamine, 4-amino-3-methyldiphenylamine, 4-amino-3-ethoxydiphenylamine, 4-amino-3 (β-hydroxyethoxy) diphenylamine, 4-aminodiphenylamine-
Examples thereof include 2-sulfonic acid, 4-aminodiphenylamine-2-carboxylic acid, and 4-aminodiphenylamine-2′-carboxylic acid.

The diazo resin can be prepared by a known method, for example,
According to the method described in Photographic Science Engineering (Photo. Sci. Eng.) Vol. 17, p. 33 (1973), U.S. Pat. No. 2,063,631, in sulfuric acid, phosphoric acid or hydrochloric acid. It is obtained by polymerizing an aromatic diazonium salt, an aromatic compound giving an aromatic group represented by A, and an active carbonyl compound, for example, paraformaldehyde, acetaldehyde, benzaldehyde or acetone or acetophenone.

The aromatic compound, an aromatic diazo compound, an active carbonyl compound and the like, which give an aromatic group represented by A in the general formula (ii), can be freely combined with each other. It is also possible to mix and condense the above.

The charged molar ratio of the aromatic compound giving an aromatic group represented by A and the aromatic diazonium compound is preferably 1: 0.1 to 0.1: 1, more preferably 1: 1.
0.5-0.2: 1, more preferably 1: 1-0.2:
It is one. Further, in this case, the total of the aromatic compound and the aromatic diazonium compound which give an aromatic group represented by A and the aldehyde or ketone are usually usually preferably in a molar ratio of 1: 0.6 to 1: 1. 5, more preferably 1: 0.
The diazo resin can be obtained by charging at 7 to 1: 1.2 and reacting at a low temperature for a short time, for example, about 3 hours.

The counter anion of the above diazo resin includes an anion which forms a salt with the diazo resin stably and makes the resin soluble in an organic solvent. Those forming such anions include organic carboxylic acids such as decanoic acid and benzoic acid, and organic phosphoric acids and sulfonic acids such as phenylphosphoric acid. Typical examples include methanesulfonic acid and chloroethanesulfonic acid. , Dodecanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, mesitylenesulfonic acid, anthraquinonesulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, hydroxysulfonic acid, 4-acetylbenzenesulfonic acid, dimethyl-5 Aliphatic and aromatic sulfonic acids such as sulfoisophthalate, hydroxyl-containing aromatic compounds such as 2,2 ', 4,4'-tetrahydroxybenzophenone and 1,2,3-trihydroxybenzophenone, hexafluorophosphoric acid,
Examples thereof include halogenated Lewis acids such as tetrafluoroboric acid, and perhalogen acids such as perchloric acid and periodic acid. However, it is not limited to these. Particularly preferred among these are hexafluorophosphoric acid and mesitylenesulfonic acid.

In the present invention, the molecular weight of the diazo resin used is not particularly limited. For example, the molecular weight of the above-mentioned co-condensed diazo resin can be arbitrarily changed by variously changing the molar ratio of each monomer and the condensation conditions. Can be obtained as a value. In the present invention, generally, those having a molecular weight of about 400 to 10,000 can be used effectively, and those having a molecular weight of about 800 to 5,000 are more suitable.

The amount of the diazo resin to be added to the photosensitive composition is preferably 1 to 30% by weight, more preferably 3 to 15% by weight based on the solid content of the photosensitive composition.

The photosensitive composition of the present invention contains a dye or pigment for coloring the photosensitive layer and p
An H indicator or the like can be added.

Among these colorants, preferred are:
Dyes which form a salt with an acid and change the color tone are exemplified. These pigments include, for example, Victoria Pure Blue B
OH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue # 603 (manufactured by Orient Chemical Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), crystal violet, brilliant green, ethyl violet, methyl violet,
Methyl green, erythrosin B, basic fuchsin, malachite green, oil red, m-cresol purple, rhodamine B, auramine, 4-p-diethylaminophenylimino naphthoquinone, cyano-p-
Examples of discoloring agents in which triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes represented by diethylaminophenylacetanilide and the like change from colored to colorless or different colored tones No.

On the other hand, examples of the color changing agent which changes from colorless to colored include leuco dyes and, for example, triphenylamine, diphenylamine, o-chloroaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p '-Bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p, p',
p "-tris-dimethylaminotriphenylmethane,
p, p'-bis-dimethylaminodiphenylmethylimine, p, p ', p "-triamino-o-methyltriphenylmethane, p, p'-bis-dimethylaminodiphenyl-4-anilinonaphthylmethane, p, Primary or secondary arylamine dyes represented by p ', p "-triaminotriphenylmethane are exemplified.

Particularly preferred are triphenylmethane-based and diphenylmethane-based dyes, more preferably triphenylmethane-based dyes, and particularly Victoria Pure Blue BOH.

The above dye is generally contained in the photosensitive composition in a total solid content of 0.5 to 10% by weight, preferably about 1 to 5% by weight.

Various additives can be further added to the photosensitive composition of the present invention.

For example, alkyl ethers (eg, ethylcellulose, methylcellulose), fluorinated surfactants, and nonionic surfactants (eg, Pluronic L-64 (Asahi Denka Co., Ltd.)
)), A plasticizer (for example, butylphthalyl, polyethylene glycol,
Tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid), images Sensitizer for improving the oil sensitivity of the part (for example, see JP-A-5
5-527, half-esterified product of styrene-maleic anhydride copolymer with alcohol), stabilizer (for example, phosphoric acid, phosphorous acid, organic acid (citric acid, oxalic acid, benzenesulfonic acid, naphthalene sulfone) acid,
4-methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric acid, etc.), development accelerators (eg, higher alcohols, acid anhydrides, etc.). The amount of these additives varies depending on the purpose of use, but is generally 0.01 to 30% by weight based on the total solid content of the photosensitive composition.

When such a photosensitive composition is applied to the production of a photosensitive lithographic printing plate, the photosensitive composition is coated on a suitable support.

As the support used for the photosensitive lithographic printing plate, paper, plastic (for example, polyethylene, polypropylene, polystyrene, etc.) laminated paper, metal such as aluminum (including aluminum alloy), zinc, copper and the like can be used. Board, plastic film such as cellulose diacetate, cellulose triacetate, cellulose propionate, polyethylene terephthalate, polyethylene, polypropylene, polycarbonate polyvinyl acetal, etc .; paper or plastic film on which the above-mentioned metal is laminated or vapor-deposited; aluminum or chrome A plated steel sheet and the like can be mentioned, and among these, aluminum and an aluminum-coated composite support are particularly preferable.

The surface of the aluminum plate is desirably subjected to a surface roughening treatment for the purpose of increasing water retention and improving adhesion to the photosensitive layer.

Examples of the surface roughening method include generally known methods such as a brush polishing method, a ball polishing method, electrolytic etching, chemical etching, liquid honing, sand blast and the like, and a combination thereof. Examples include etching, chemical etching and liquid honing, of which a surface roughening method including the use of electrolytic etching is preferred. As the electrolytic bath used in the electrolytic etching, an aqueous solution containing an acid, an alkali or a salt thereof or an aqueous solution containing an organic solvent is used, and among these, an electrolytic solution containing hydrochloric acid, nitric acid or a salt thereof is particularly used. Liquids are preferred. Further, the roughened aluminum plate is desmutted with an acid or alkali aqueous solution as required. The aluminum plate thus obtained is desirably subjected to anodic oxidation treatment, and particularly preferably a method of treating with a bath containing sulfuric acid or phosphoric acid. Further, if necessary, a surface treatment such as treatment with alkali silicate or hot water, or immersion in a water-soluble polymer compound or an aqueous solution of potassium fluorozirconate can be performed.

Examples of the water-soluble polymer compound include carboxymethylcellulose and its alkali metal salts, polyvinylphosphonic acid, dextrin, gum arabic, pectin, carrageenan, hydroxyethylcellulose, alginic acid and its alkali metal salts, polyacrylic acid, polyvinyl alcohol And the like.

To provide the above-described photosensitive composition on a support, a predetermined amount of the above-mentioned ethylenic monomer, vinyl copolymer, photopolymerization initiator, diazo resin and, if necessary, various additives is added. Suitable solvents (methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethyl sulfoxide, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl lactate, ethyl lactate, 4-hydroxy-2-butanone , Methyldiglycol, water or a mixture thereof) to prepare a coating solution of the photosensitive composition, which is then coated on a support and dried. The concentration of the photosensitive composition at the time of application is desirably in the range of 1 to 50% by weight. In this case, the application amount of the photosensitive composition is about 0.1.
It may be about ² to 10 g / m ² .

On the layer of the photosensitive composition provided on the support, in order to prevent a polymerization action by oxygen in the air, for example, polyvinyl alcohol, acidic celluloses and the like have excellent oxygen barrier properties. A protective layer made of a polymer may be provided.

Exposure of a photosensitive layer coated and formed on a support,
Development can be performed according to a conventional method. That is, a line image,
Exposure through a transparent original having a halftone image, etc., and then
By developing with an aqueous developer, a negative relief image is obtained for the original image. As a light source of active light suitable for exposure, a carbon arc lamp, a mercury lamp, a xenon lamp, a metal halide lamp, a strobe, and the like can be given.

The developer of the photosensitive composition of the present invention is not particularly limited, but is preferably an aqueous alkali solution containing a small amount of an organic solvent such as benzyl alcohol, 2-phenoxyethanol or 2-butoxyethanol. , 475,171 and 3,615,480 can be used. Further, the developer described in Japanese Patent Application No. 8-347531 is also excellent as a developer for the photosensitive composition of the present invention.

[0080]

EXAMPLES The present invention will be described more specifically with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. .

Production Example 1: Synthesis of Binder-1 45 g of vinyl methacrylate, 2-hydroxy-3-allyloxypropyl methacrylate (HAO) were placed in a 3 L four-necked flask equipped with a stir bar equipped with a wing, reflux cooling, and a nitrogen tube.
60 g of PMA), 8.0 g of acrylonitrile, 13 g of methacrylic acid and 1.6 L of ethanol as a reaction solvent were heated and stirred in an oil bath at 80 ° C. 1.6 g of azobisisobutyronitrile (AIBN) was added to the solution.
Dissolved in 00 mL of ethanol and added.

After heating and stirring for 3 hours, the nitrogen tube was removed and p
-0.04 g of methoxyphenol, propylene glycol monomethyl ether acetate (PGM-AC) 40
0 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 an ethylenic polymer binder (abbreviated as “binder-1”) (Mw = 230,000). The obtained binder solution was diluted with PGM-AC and used as a 20% by weight solution.

Production Example 2: Synthesis of Binder-3 Methyl methacrylate / isobutyl methacrylate / isobutyl acrylate / methacrylic acid = 35/20 /
10/35 mol% (charge ratio) of copolymer (Mw = 7)
Hereafter, it is abbreviated as “binder-2”. ) 200 parts by weight, 75 parts by weight of an alicyclic epoxy-containing unsaturated compound having the following structure, p
-2.5 parts by weight of methoxyphenol, 8 parts by weight of tetrabutylammonium chloride and 800 parts by weight of propylene glycol monomethyl ether acetate are added into a reaction vessel, and the mixture is stirred at 110 ° C. for 24 hours in the air to produce an ethylenic polymer binder. A 25% by weight solution of an acid value of 60 and an unsaturated group reacted with 60% of the entire methacrylic acid component of the binder-2, hereinafter abbreviated as "binder-3", was obtained.

[0084]

Embedded image

Production Example 3: Synthesis of diazo resin 3.5 g (0.025 mol) of p-hydroxybenzoic acid and 21.75 g of p-diazodiphenylamine sulfate
(0.075 mol) was dissolved in 90 g of concentrated sulfuric acid under ice-cooling. After this reaction, 2.7 g of p-formaldehyde (0.09 mol) was added slowly. At this time, the reaction temperature was controlled not to exceed 10 ° C. Thereafter, stirring was continued under ice cooling for 2 hours. The reaction mixture was poured into 1 L of methanol under ice cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 200 mL of pure water, and a cold concentrated aqueous solution in which 10.5 g of zinc chloride was dissolved was added to this solution. The resulting precipitate was filtered, washed with ethanol, and dissolved in 300 mL of pure water. 1 in this liquid
A cold concentrated aqueous solution in which 3.7 g of ammonium hexafluorophosphate was dissolved was added. The resulting precipitate was separated by filtration, washed with water, and dried at 30 ° C. for 24 hours to obtain a diazo resin. The molecular weight of this co-condensed diazo resin was measured by GPC (gel permeation chromatography) and found to be about 2300 in weight average molecular weight.

Production Example 4 Production of Aluminum Support-1 An aluminum plate was degreased with 3% by weight of sodium hydroxide, and was degreased in a 18.0 g / L nitric acid bath at 25 ° C. and 80 A / A.
electrolytic etching at a current density of dm ² for 15 seconds,
A desmutting treatment was performed for 5 seconds at 50 ° C. with a 10% by weight aqueous solution of sodium hydroxide,
Neutralized at 5 ° C for 5 seconds. After washing with water, anodized in a 30% by weight sulfuric acid bath at 30 ° C. and 10 A / dm ² for 16 seconds,
After washing with water and drying, an aluminum plate for a lithographic printing plate (hereinafter abbreviated as "support-1") was obtained.

Production Example 5: Production of aluminum support-2 An aluminum plate was degreased with 3% by weight of sodium hydroxide, and was degreased in a 18.0 g / L nitric acid bath at 25 ° C and 80 A /
electrolytic etching at a current density of dm ² for 15 seconds,
A desmutting treatment is performed for 5 seconds at 50 ° C. with an aqueous solution of sodium hydroxide at 25 ° C.
For 5 seconds. After washing with water, 30% by weight sulfuric acid
Anodizing was performed for 16 seconds at 10 ° C. and 10 A / dm ² , followed by washing with water. Finally, a 1% by weight aqueous solution of sodium metasilicate 85
C. for 30 seconds, washed with water and dried to obtain an aluminum plate for a lithographic printing plate (hereinafter abbreviated as "support-2").

Examples 1 and 2 and Comparative Examples 1 to 3 A photosensitive solution having a composition shown in Table 1 was filtered on a support shown in Table 1 and then dried using a bar coater to a dry film thickness of 1.5 g / m ^2.
And dried.

A step guide made by Konica was vacuum-adhered to the obtained photosensitive lithographic printing plate, and exposed with a 2 KW metal halide lamp from a distance of 60 cm for the time shown in Table 1,
After being immersed in a developer shown in Table 1 at 25 ° C. for 20 seconds, it was rubbed lightly with absorbent cotton and developed. Next, a desensitizing treatment was performed with a gum solution to obtain a lithographic printing plate. The following four items were evaluated for the obtained lithographic printing plate, and the results are shown in Table 1.

The compositions of the developing solutions A and B used are as follows.

<Composition of developer A (g)> Benzyl alcohol: 3.0 Triethanolamine: 3.0 Perex NBL (manufactured by Kao Corporation): 3.0 Pure water: 100 <Composition of developer B (g)> Anhydrous Sodium carbonate: 0.5 Perex NBL (manufactured by Kao Corporation): 3.0 Pure water: 100 <Sensitivity> The number of solid steps in the step guide was visually evaluated.

<Printing Durability> The photosensitive lithographic printing plate was scanned and exposed with an air-cooled argon laser (trade name “PI-R” manufactured by Dainippon Screen Co., Ltd.) at an exposure of 100 μj / cm ² to evaluate the sensitivity. Development is performed in the same manner. The obtained printing plate is referred to as “DAIYA-1F-2 type” (manufactured by Mitsubishi Heavy Industries, Ltd.).
And the number of printed sheets until the image area (175 lines, 3% small point) jumps is shown as printing durability.

<Chemical Resistance> The exposed and developed sample was immersed in a UV washing oil manufactured by Matsui Chemical Co. for 30 minutes, and the residual film ratio was calculated from the reflection density (red filter).

<Presence or Absence of Aggregation of Initiator> The photosensitive lithographic printing plate was stored at room temperature for 3 months, exposed to light over the entire surface, and visually observed for unevenness of the exposed visible image on the plate surface.

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[Table 1]

Table 1 shows that the photosensitive lithographic printing plate using the photosensitive composition of the present invention is superior to the conventional lithographic printing plate in all of sensitivity, chemical resistance, printing durability and storage safety. .

[0097]

As described in detail above, according to the present invention, a photosensitive composition having both excellent sensitivity, chemical resistance, printing durability and storage stability over time, and the use of such a photosensitive composition. A photosensitive lithographic printing plate is provided.

Claims (6)

[Claims] 1. An ethylenically unsaturated double bond-containing monomer, an alkaline water-soluble or swellable acidic vinyl copolymer,
In a photosensitive composition comprising a photopolymerization initiator,
A photopolymerizable composition, wherein the photopolymerization initiator contains two or more triazine compounds represented by the following general formula. Embedded image (In the formula, R ¹ is a substituted or unsubstituted aliphatic group or aromatic group, and R ² and R ³ independently represent a haloalkyl group.) 2. The photosensitive composition according to claim 1, wherein the alkaline water-soluble or swellable acidic vinyl copolymer has an unsaturated group in a side chain. 3. The photosensitive composition according to claim 2, wherein the unsaturated group in the side chain is an allyl group and / or a vinyl group. 4. The photosensitive composition according to claim 1, further comprising a diazo resin. 5. The diazo resin according to claim 4, wherein the diazo resin is a cocondensation compound containing, as constituent units, an aromatic compound residue having a carboxyl group and / or a hydroxyl group and an aromatic diazonium compound residue. Photosensitive composition. 6. A photosensitive lithographic printing plate comprising a support having been subjected to a surface treatment and a photosensitive layer containing the photosensitive composition according to claim 1 provided thereon.