JP2001066773A - Photosensitive composition and photosensitive lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive composition for a lithographic printing plate which is high in sensitivity and superior in resistances to chemicals and printing. SOLUTION: This photosensitive composition comprises a monomer, having an ethylenically unsaturated bond and an acidic vinyl copolymer soluble or swellable in an aqueous solution of alkali and having unsaturated groups on its side chains and a photopolymerization initiator containing a titanocene compound and a halomethyloxadiazole compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photosensitive composition and a photosensitive lithographic printing plate. Particularly, the present invention relates to a photopolymerizable photosensitive composition having excellent sensitivity and a photosensitive lithographic printing plate having excellent chemical resistance and printing durability.

[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 crosslinked to make it insoluble in a developer,
It is obtained by dissolving the non-irradiated portion in the developing solution and forming each portion as an image portion that repels water and receives ink and a non-image portion that receives water and repels ink. Conventionally, as a photosensitive composition used for such a purpose, a photopolymerizable composition is well known and is partially used in practice, but any of the photosensitive compositions is a photosensitive composition of a lithographic printing plate. When used as a layer, the plate needs to be replaced in the middle due to wear of the plate, and problems such as deterioration of the image area due to a chemical used when wiping the surface of the plate are caused. In order to improve these problems, Japanese Patent Publication No. 3-63740 and Japanese Patent Publication No.
JP-A-105353 discloses the use of a binder having a crosslinkable group such as an allyl group or a vinyl group. These binders can solve the above problems and can achieve high sensitivity, and have come to be used practically, but further higher sensitivity is desired. See also
JP-A-3-261352 discloses a photosensitive composition using an oxadiazole compound, and JP-A-5-132507 discloses a photosensitive composition using a titanocene compound. I didn't have it.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photosensitive composition which has higher sensitivity than before and has excellent printing durability and chemical resistance.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that by combining a specific compound as a photopolymerization initiator, all of the sensitivity, printing durability, and chemical resistance can be attained. It was found that an excellent photosensitive composition was obtained in the above, and the present invention was achieved. That is, the gist of the present invention is:
In a photosensitive composition containing an ethylenically unsaturated bond-containing monomer, an alkaline water-soluble or swellable acidic vinyl copolymer and a photopolymerization initiator, the photopolymerization initiator is a titanocene compound and a halomethyloxadiazole compound. In the photosensitive composition characterized by containing. Other points are:
The present invention relates to a photosensitive lithographic printing plate having a layer comprising the above photosensitive composition on a support.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The addition-polymerizable ethylenically unsaturated bond-containing monomer (hereinafter abbreviated as "ethylenic monomer") contained as a first essential component in the photosensitive composition of the present invention is defined as an active substance of the photosensitive composition. A monomer having an ethylenically unsaturated bond that undergoes addition polymerization and cures by the action of a photopolymerization initiation system, which is the third essential component, when irradiated with light. In the present invention, the meaning of the monomer is a concept corresponding to a so-called polymer, and therefore includes not only a monomer in a narrow sense but also a dimer, a trimer, and an oligomer. It is.

Examples of the ethylenic monomer used in the present invention include, for example, an ester of an aliphatic polyhydroxy compound and an unsaturated carboxylic acid; an ester of an aromatic polyhydroxy compound and an unsaturated carboxylic acid; Examples include an ester obtained by an esterification reaction of a polyhydroxy compound such as a polyhydroxy compound and an aromatic polyhydroxy compound with an unsaturated carboxylic acid and a polycarboxylic acid.

The ester of the aliphatic polyhydroxy compound and the unsaturated carboxylic acid is not limited, but ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, Acrylic esters of aliphatic polyhydroxy compounds such as pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, glycerol acrylate, and acrylates of these exemplified compounds as methacrylates Methacrylic acid ester replaced with itacone also replaced with itaconate Esters, maleic acid esters, and the like was replaced with crotonic acid ester or maleate was replaced Kuroneto.

Examples of the ester of an aromatic polyhydroxy compound with an unsaturated carboxylic acid include acrylic acid esters of 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 unsaturated carboxylic acid, polycarboxylic acid and polyhydric hydroxy compound is not necessarily a single substance, but typical examples include acrylic acid, phthalic acid and There are condensates of ethylene glycol, condensates of acrylic acid, maleic acid, and diethylene glycol, condensates of methacrylic acid, terephthalic acid, and pentaerythritol, and condensates of acrylic acid, adipic acid, butanediol, and glycerin.

Other examples of the ethylenic monomer used in the present invention include a reaction between a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate or a reaction between a polyisocyanate compound and a polyol and a hydroxyl group-containing (meth) acrylate. (Meth) acrylates as obtained by the above method; 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; phthalic acid Allyl esters such as diallyl; vinyl group-containing compounds such as divinyl phthalate are useful. The addition-polymerizable ethylenically unsaturated bond-containing monomer of the present invention is used in an amount of usually 5 to 70% by weight, more preferably 10 to 10% by weight, based on the solid content of the photosensitive composition.
It is preferably contained at 60% by weight.

Next, the alkaline water-soluble or swellable acidic vinyl copolymer (hereinafter abbreviated as vinyl copolymer), which is the second essential component of the present invention, will be described. Specific examples of such vinyl copolymers include, for example, (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, maleic acid, (meth) acrylonitrile, styrene, vinyl acetate, vinylidene chloride, maleimide and the like. Examples thereof include a copolymer of a compound having a vinyl group, polyethylene oxide, polyvinyl pyrrolidone, polyamide, polyurethane, polyester, polyether, polyethylene terephthalate, acetyl cellulose, and polyvinyl butyral. Among them, a copolymer containing (meth) acrylic acid ester and at least one (meth) acrylic acid as a copolymer component is preferable. Preferred acid value of the vinyl copolymer is 10 to 250,
The preferred weight average molecular weight (hereinafter abbreviated as Mw) is 5,000 to 500,000. Among these vinyl copolymers, it is desirable to have an unsaturated bond in the side chain, and it is particularly preferable to have at least one kind of unsaturated bond represented by the following general formulas (1) to (3). The synthesis is roughly divided into the following 2
There are two ways.

[0012]

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(Wherein R _{1 to} R ₅ are independently hydrogen, halogen, carboxyl, sulfo, nitro, cyano, amide,
Amino and, optionally, alkyl, aryl, alkoxy, aryloxy, alkylamino, arylamino, alkylsulfonyl, and arylsulfonyl, each of which may have a substituent; Z is oxygen, sulfur,
It is a group represented by NH or NR (R is an alkyl group). )

(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 proportion of the carboxyl group to be reacted with the epoxy group-containing unsaturated compound is generally preferably 5 to 90 mol%, more preferably 20 to 80 mol%, and still more preferably 30 to 70 mol%, based on all carboxyl groups. It is. Within the above range, the developing property is good and the adhesive property is good. The epoxy group-containing unsaturated compound used in the production of the ethylenic polymer binder having an unsaturated group in the side chain is a compound having at least one addition-polymerizable unsaturated bond in one molecule and an epoxy group. .

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 monoalkyl fumarate monoglycidyl ester and monoalkyl maleate monoglycidyl ester, and unsaturated compounds containing an alicyclic epoxy group represented by the following structure.

[0016]

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[0017]

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[0018] (in each formula, R ²¹ is .R ²² represents a hydrogen atom or a methyl group .R ²³ showing a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms having 1 to 10 carbon atoms It represents a divalent hydrocarbon group, and l represents an integer of 0 to 10.) Specific examples of preferable compounds of the above epoxy group-containing unsaturated compound include glycidyl methacrylate, allyl glycidyl ether, and 3,4-epoxycyclohexyl. Methyl acrylate and the like can be mentioned. Among these, particularly preferred compounds are allyl glycidyl ether and 3,4-epoxycyclohexylmethyl acrylate.

(Synthesis method 2) The unsaturated bond having low reactivity as shown in the above general formulas (2) and (3) is
A method of synthesizing by copolymerizing an unsaturated carboxylic acid with a compound having two or more kinds of unsaturated bonds, one or more kinds of which are more reactive, and one kind of unsaturated bond having higher reactivity. 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, N, N-diallyl (meth) acrylamide, cinnamyl (Meth) acrylate, crotonyl (meth) acrylate, methallyl (meth) acrylate, and the like.

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. These (2),
Preferred compounds among the compounds having the structure of (3) include allyl methacrylate and vinyl methacrylate.

By copolymerizing these monomers with an unsaturated carboxylic acid, preferably acrylic acid or methacrylic acid, a copolymer having the unsaturated group is obtained. 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 10 to 10%.
90 mol%, more preferably 30 to 80 mol%. If the amount is less than this range, the image reproducibility is poor, and if the amount is too large, the developability may be deteriorated.

The vinyl copolymer of the present invention is used in an amount of usually 30 to 95% by weight, preferably 40 to 95% by weight, based on the solid content of the photosensitive composition.
95% by weight is contained. Next, the photopolymerization initiator, which is the third essential component of the photopolymerizable composition of the present invention, will be described.
The present invention is characterized in that a titanocene compound is used in combination with a halomethyloxadiazole compound as a photopolymerization initiator. As the halomethyloxadiazole compound,
Any compound may be used as long as it has a halomethyl group and an oxadiazole structure and generates an active radical upon irradiation with light. Among them, the halomethyloxadiazole compound is preferably a compound having the following structure.

[0023]

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(Wherein X represents a chlorine atom or a bromine atom, A represents an aryl group or a heterocyclic group which may be substituted, and n represents an integer of 0, 1 or 2). , A phenyl group or a naphthyl group as a heterocyclic group is a 5- to 7-membered ring having an oxygen or nitrogen atom, and such a heterocyclic ring may form a condensed ring. Examples of the substituent include a hydroxyl group, C ₁ -C ₆ alkyl group, C ₁ -C
₆ alkoxy groups and optionally substituted vinyl groups. Specific examples of preferred compounds among the oxadiazole-based compounds are shown below.

[0025]

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As the titanocene compound, various compounds having a titanocene structure can be used. For example, JP-A-59-152396 and JP-A-61-15119 can be used.
It can be used by appropriately selecting from various titanocenes described in each publication of No. 7. More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5 , 6-Pentafluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2 , 4,6-Trifluorophenyl-1-yl, dicyclopentadienyl-Ti-2,6-difluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-
2,4-di-fluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6
-Pentafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluoro-3 Titanocene compounds having a dicyclopentadienyl group such as-(pyr-1-yl) -phenyl-1-yl can be given.

In the present invention, the sensitivity, chemical resistance and printing durability are improved by using the above two initiators in combination. The mixing ratio (weight ratio) of the halomethyloxadiazole and the titanocene compound is generally 10: 1 to 1:10, preferably 5: 1 to 1
1: 5. As a photopolymerization initiator, in addition to the above-mentioned compounds, other initiators for initiating the polymerization of the ethylenic monomer can be used in combination, for example, benzoin, benzoin alkyl ether, benzophenone, anthraquinone-based compound, Michler's ketone, triazine Any of a series compound, a biimidazole series compound, a thioxanthone series compound, an aromatic tertiary amine and the like can be suitably used.
Specific examples of these photopolymerization initiators and preferable examples of the combination are described in “UV / EB Curing Handbook-Raw Materials-”, edited by Kato Kiyomi (Polymer Publishing Association), pp. 67-73.
“Applications and Markets of UV / EB Curing Technology”, supervised by Yoneho Tabata, edited by Radtech Research Group (CMC), pp. 64 to 82, JP-B-6-42074, JP-A-62-61
04, JP-A-60-35725, JP-A-2-2875
47. In addition, Japanese Unexamined Patent Publication
Compounds capable of generating an acid upon irradiation with actinic rays, described in JP-A-362643 and JP-A-4-362644, can also be used as the photopolymerization initiator. The photopolymerization initiator that can be used in the present invention is not limited to the above specific examples. The photopolymerization initiator in the invention is usually contained in the solid content of the photosensitive composition in an amount of 0.2 to 30% by weight, more preferably 0.5 to 10% by weight. In the present invention, a diazo resin can be further added to the photosensitive composition for the purpose of imparting adhesion of the formed photosensitive layer to the support.

The diazo resin that can be used in the present invention includes:
Any known diazo resin may be used as the diazo resin contained in the photosensitive composition. Among them, it is preferable to use a photosensitive compound having a structure represented by the following general formula (i) or (ii), and in particular, a compound represented by (ii) Are preferred.

[0029]

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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-. )

[0031]

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((Ii) In the formula, 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 which can be used for providing the aromatic group represented by A include m-chlorobenzoic acid, diphenylacetic acid, phenoxyacetic acid, p -Methoxyphenylacetic acid,
p-methoxybenzoic acid, 2,4-dimethoxybenzoic acid,
2,4-dimethylbenzoic acid, p-phenoxybenzoic acid,
4-anilinobenzoic acid, 4- (m-methoxyanilino)
Benzoic acid, 4- (p-methylbenzoyl) benzoic acid, 4
-(P-methylanilino) benzoic acid, phenol,
(O, m, p) -cresol, xylenol, resorcin, 2-methylresorcin, (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'-dihydroxydiphenylether, 4,4'-dihydroxydiphenylamine, 4,4'-dihydroxydiphenylsulfide, 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 which is a constituent unit of the diazo resin represented by the above general formulas (i) and (ii), for example, a diazonium salt as described in JP-B-49-48001 may 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 above 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, Halogenated Louis such as tetrafluoroboric acid Examples thereof include perhalic acids such as succinic acid, 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 content of the diazo resin in the photosensitive composition is preferably 0.5 to 30% by weight, more preferably 1 to 15% by weight based on the solid content of the photosensitive composition. . To the photosensitive composition of the present invention, a coloring agent such as a dye or a pigment for coloring the photosensitive layer, and a pH indicator or the like as a printing-out agent 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 Industries), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Company), 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 usually contained in an amount of 0.5 to 10% by weight, preferably about 1
-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. Such a photosensitive composition is usually used after being dissolved in an appropriate solvent. When applied to the production of a photosensitive lithographic printing plate, this photosensitive composition is coated on a suitable support.

In order to provide the above-mentioned photosensitive composition on a support, the above-mentioned ethylenic monomer, vinyl copolymer, photopolymerization initiator and, if necessary, further additives such as various additives of a diazo resin are used. A predetermined amount of a suitable solvent (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, apply it on a support, and dry it. 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 coating amount of the photosensitive composition is about 0.2 to 10 g / m ² .

As the support used for the photosensitive lithographic printing plate, paper, plastic (eg, polyethylene, polypropylene, polystyrene, etc.) laminated paper, metal (such as aluminum (including aluminum alloy)), zinc, copper, etc. 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 Examples thereof include a plated steel sheet and the like, and among these, an aluminum support and an aluminum-coated composite support are particularly preferable. The surface of the aluminum support 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.

On the layer of the photosensitive composition provided on the support, in order to prevent a polymerization action due to 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 preferred examples thereof include benzyl alcohol and
An alkaline aqueous solution containing a small amount of an organic solvent such as 2-phenoxyethanol and 2-butoxyethanol. For example, US Pat. Nos. 3,475,171 and 3,615,480.
Can be mentioned. Further, the developer described in JP-A-11-30858 is also excellent as a developer for the photosensitive composition of the present invention.

[0053]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

Synthesis of Binder-1 45 g of vinyl methacrylate 60 g of 2-hydroxy-3-allyloxypropyl methacrylate 60 g of acrylonitrile 13 g of methacrylic acid and reaction solvent in a 3 L four-necked flask equipped with a stir bar with wings, reflux cooling and a nitrogen tube 1.6L of ethanol was added, and the mixture was heated and stirred in an oil bath at 80 ° C. 1.6 g of azobisisobutyronitrile dissolved in 400 ml of ethanol was added to this solution. After heating and stirring for 3 hours, remove the nitrogen tube.
-Methoxyphenol 0.04 g propylene glycol monomethyl ether acetate (abbreviated as PGM-AC) 40
0 ml was added, the bath temperature was raised to 100 ° C., and heating and stirring were continued for 1 hour. Finally, ethanol was distilled off to obtain a 23% by weight solution of a vinyl copolymer having an unsaturated group in the side chain (abbreviated as “binder-1”) (MW 230,000). The obtained solution of binder-1 was diluted with PGM-AC and used as a 20% by weight solution.

Synthesis of diazo resin 1 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 paraformaldehyde (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, the precipitate was dissolved in 200 ml of pure water, and to this solution was added a cold concentrated aqueous solution in which 10.5 g of zinc chloride was dissolved. 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 collected by filtration, washed with water, and dried at 30 ° C. for 24 hours to obtain diazo resin 1. The molecular weight of this co-condensed diazo resin 1 was measured by GPC (gel permeation chromatography).
The weight average molecular weight was about 2300.

Preparation of Aluminum Support The aluminum plate was degreased with 3% sodium hydroxide and electrolytically etched in a 18.0 g / l nitric acid bath at 25 ° C. and a current density of 80 A / dm ² for 15 seconds. % Sodium hydroxide aqueous solution at 50 ° C for 5 seconds, then 10%
The solution was neutralized at 25 ° C for 5 seconds in a 25% aqueous solution of nitric acid. After washing with water, it was anodized in a 30% sulfuric acid bath at 30 ° C. and 10 A / dm ² for 16 seconds and washed with water. Finally, a 1% aqueous solution of sodium metasilicate was treated at 85 ° C. for 30 seconds, washed with water and dried to obtain an aluminum plate for a lithographic printing plate.

Example 1 and Comparative Examples 1-2 The following photosensitive solution I was prepared. Photosensitive solution I Pentaerythritol tetraacrylate 1.0 g Binder-1 (20% by weight PGM-AC solution) 14 g Oxadiazole compound having the following structure

[0058]

Embedded image

A titanocene compound having the following structure

[0060]

Embedded image

Diazo resin 1 0.20 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.12 g Julimer AC-10L (manufactured by Nippon Pure Chemical Co., Ltd.) 0.12 g Methyl cellosolve 30 g

After the photosensitive solution I was filtered, the weight after drying on the above aluminum support using a bar coater was 1.5%.
g / m ² . The photosensitive lithographic printing plate thus obtained was designated as Sample A. As a comparative example, the following photosensitive solution II and photosensitive solution III were prepared and coated on a support in the same manner as in Example 1. The obtained photosensitive lithographic printing plates were designated as Sample B and Sample C, respectively.

Photosensitive Liquid II (Comparative Example 1) Pentaerythritol tetraacrylate 1.0 g Binder-1 (20 wt% PGM-AC solution) 14 g Oxadiazole compound having the following structure

[0064]

Embedded image

Diazo resin 0.20 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.12 g Julimer AC-10L (manufactured by Nippon Pure Chemical Co., Ltd.) 0.12 g Methyl cellosolve 30 g

Photosensitive solution III (Comparative Example 2) Pentaerythritol tetraacrylate 1.0 g Binder-2 (20 wt% PGM-AC solution) 14 g Titanocene compound having the following structure

[0067]

Embedded image

Diazo resin 0.20 g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.12 g Julimer AC-10L (manufactured by Nippon Pure Chemical Co., Ltd.) 0.12 g Methyl cellosolve 30 g

The obtained photosensitive lithographic printing plates (samples A to
C) A step guide made by Konica is vacuum-adhered to C), and 2
It is 60 from a distance of 60cm with a metal halide lamp of KW.
Exposure for 2 seconds, immersion in a developer having the following composition at 25 ° C. for 20 seconds, and rubbing lightly with absorbent cotton for development. Next, a desensitizing treatment was performed with a gum solution to obtain a printing plate.

Developer Benzyl alcohol: 3.0 g Triethanolamine: 3.0 g Perex NBL (manufactured by Kao Corporation): 3.0 g Pure water: 100 g The following items were evaluated for samples A to C, and the results were shown in Table 1.
1 is shown.

<Sensitivity> The number of solid steps of the step guide was visually evaluated. The higher the number of steps, the better the sensitivity. <Printing durability> The printing plate was printed with "DAIYA-1F-2" (manufactured by Mitsubishi Heavy Industries, Ltd.), and the image area (175 lines, 3%
The number of prints before the point (dot) jumps is shown as printing durability. <Chemical resistance> The exposed and developed sample was immersed in UV washing oil manufactured by Matsui Chemical Co. for 30 minutes, and the residual film ratio was calculated from the reflection density (red filter). The higher this value, the higher the residual film ratio and the better the chemical resistance.

[0072]

[Table 1]

[0073]

The photosensitive lithographic printing plate using the photosensitive composition of the present invention is superior to conventional products in all of sensitivity, chemical resistance and printing durability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/038 G03F 7/038 F-term (Reference) 2H025 AA01 AA06 AA12 AB03 AC01 AD01 BA03 BC12 BC31 BC43 BC51 BC52 BC81 BC84 BE08 CA39 CB13 CB14 CB42 CB43 CB52 FA17 2H096 AA06 BA03 BA05 EA02 GA08 4J011 QA13 QA17 QA18 QA19 QA20 QA23 QA24 QA26 QB01 QB02 QB03 QB11 QB12 QB13 QB14 QB15 RAB SA14 QB15 SAB08 UA01 VA01 WA10

Claims (6)

[Claims] 1. A photosensitive composition comprising an ethylenically unsaturated bond-containing monomer, an alkaline water-soluble or swellable acidic vinyl copolymer and a photopolymerization initiator, wherein the photopolymerization initiator comprises a titanocene compound and a halo. A photosensitive composition comprising a methyloxadiazole compound. 2. The photosensitive composition according to claim 1, wherein the halomethyloxadiazole compound is a compound represented by the following general formula (I). Embedded image (In the formula, X represents a chlorine atom or a bromine atom, A represents an optionally substituted aryl group or a heterocyclic group, and n represents an integer of 0, 1 or 2.) 3. 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. 4. The photosensitive composition according to claim 1, further comprising a diazo resin. 5. The photosensitive composition according to claim 4, wherein the diazo resin is a co-condensation compound containing, as constituent units, an aromatic compound having at least one of a carboxyl group and a hydroxyl group and an aromatic diazonium compound. Composition. 6. A photosensitive lithographic printing plate comprising a support and a layer comprising the photosensitive composition according to claim 1.