JPH04316049A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To provide the photosensitive composition excellent in visualizability by exposure to light and high in sensitivity and improved in remaining colors after development and storage stability. CONSTITUTION:This photosensitive composition comprises at least (a) an arylazo compound substituted by carboxylic or sulfonic group and/or its salt, and (b) an o-quinonediazido compound or a diazo resin.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a photosensitive composition that can be used in photosensitive lithographic printing plates, and more specifically, it relates to a photosensitive composition that has good exposure and visible image properties, little residual dye, and good sensitivity and storage stability. The present invention relates to a photosensitive composition.

0002

2. Description of the Related Art Photosensitive compositions using o-quinonediazide compounds or diazo resins as photosensitive substances are widely used, for example, in the production of photosensitive lithographic printing plates and printed circuits.

A photosensitive lithographic printing plate has an ink-receptive photosensitive layer provided on a hydrophilic support. For example, in a positive-working photosensitive lithographic printing plate, an ink-receptive photosensitive layer is provided on a hydrophilic support. An ink-receptive photosensitive layer is formed which becomes solubilized upon exposure to light.

When the photosensitive layer of such a positive-working photosensitive lithographic printing plate is subjected to imagewise exposure and then developed, the photosensitive layer in the exposed areas is removed and the surface of the hydrophilic support is exposed, while the unexposed areas are removed. The photosensitive layer remains on the support to form an ink-receiving layer.

[0005] In planographic printing, the difference in properties is utilized in that the exposed areas are hydrophilic and the unexposed areas are lipophilic.

These photosensitive planographic printing plates are required to have high sensitivity in order to improve workability. Further, in plate making, exposure work is performed, for example, so-called "multi-sided printing" in which a plurality of film originals are printed one after another while changing their positions. In these exposure operations, if it is not possible to distinguish between exposed areas and unexposed areas, the position of the exposed areas cannot be confirmed, making the exposure operations difficult and leading to incorrect exposure. In order to avoid these problems, photosensitive compositions are required to form a visible image upon exposure that can be recognized even under the yellow safety light used for exposure work (exposure visible image property). ing.

For example, o-quinonediazide compounds and diazo resins photodecompose and fade when exposed to light;
Photosensitive compositions using quinonediazide compounds or diazo resins can produce visible images when exposed to light, but the resulting visible images have low contrast and are hardly visible under the yellow safety lights used for exposure work. It was so bad that it was unrecognizable.

[0008] Various means have been proposed to improve these drawbacks and to form a clear visible image with contrast through exposure.

For example, a photosensitive composition contains a diazonium salt and a hydroxy-substituted arylazo compound, and as a result of exposure, the hue of the hydroxy-substituted arylazo compound is changed by the acid generated from the diazonium salt, thereby obtaining visible imageability by exposure. Although it is described in Japanese Patent Publication No. 55-25653, the sensitivity was lowered and the exposure visibility was still not sufficient.

Furthermore, JP-A-58-87553 discloses that a photosensitive composition contains a trihalogenomethyl-s-triazine compound or a naphthoquinonediazide sulfonyl halide compound having a specific structure and at least one nitro group. It has been described that visible image quality can be obtained by using an azo dye, but color remains after development, and
Not only was the storage stability insufficient, but also the exposure visibility was still not sufficient.

[0011]

OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide a photosensitive composition which has excellent exposure and visible image properties, high sensitivity, and improved color retention after development and storage stability.

0012

[Structure of the Invention] The above objects of the present invention are at least (a)
An arylazo compound and/or a salt thereof having a carboxyl group and/or a sulfonic acid group as a substituent, (b) o
- Achieved by a photosensitive composition characterized by containing a quinonediazide compound or a diazo resin.

The present invention will be explained in detail below.

First, the arylazo compound having a carboxyl group or a sulfonic acid group as a substituent used in the present invention will be explained.

The arylazo compound having a carboxyl group or sulfonic acid group as a substituent used in the present invention is not particularly limited, but is preferably a compound represented by the following general formula [I].

[0016]

embedded image In the formula, R1 and R2 each represent a hydrogen atom, an alkyl group, or an aryl group, and A and B represent an aromatic hydrocarbon ring group. Moreover, X represents -COOH or -SO3H. ]
In the above general formula [I], examples of the alkyl group represented by R1 and R2 include lower alkyl groups such as a methyl group, an ethyl group, and a propyl group. Examples of the aryl group include a phenyl group and a naphthyl group. These alkyl groups and aryl groups may have a substituent.

Examples of the aromatic hydrocarbon ring group represented by A and B include phenyl group and naphthyl group. These aromatic hydrocarbon ring groups may have a substituent.

[0018] Also, -COOH, -SO3 represented by X
H may be in the form of a salt. As the salt, alkali metal salts, alkaline earth metal salts and ammonium salts are preferred.

Specific examples of the compound represented by the general formula [I] are shown below, but the compounds of the present invention are not limited thereto. Further, these compounds may be, for example, alkali metal salts, alkaline earth metal salts, or ammonium salts.

[0020]

[Case 2]

[0021]

embedded image The proportion of the arylazo compound having a carboxyl group and/or sulfonic acid group as a substituent used in the present invention in the photosensitive composition is preferably 0.01 to 30% by weight, and 0.02 to 10% by weight. % by weight is particularly preferred.

Next, the o-quinonediazide compound used in the present invention will be explained.

In the photosensitive composition containing an o-quinonediazide compound used in the present invention, it is preferable to use the o-quinonediazide compound and an alkali-soluble resin together.

The o-quinonediazide compound used in the present invention is not particularly limited, and examples include ester compounds of o-naphthoquinonediazide sulfonic acid and polycondensation resins of phenols and aldehydes or ketones.

Examples of the phenols include monohydric phenols such as phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, carvacrol, and thymol, and dihydric phenols such as catechol, resorcinol, and hydroquinone. Examples include trihydric phenols such as phenol, pyrogallol, and phloroglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred among these are formaldehyde and benzaldehyde. Further, examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, m-cresol/formaldehyde resin, m-, p-mixed cresol/formaldehyde resin, resorcinol/benzaldehyde resin, pyrogallol/acetone resin, etc. It will be done.

The condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol in the o-naphthoquinonediazide compound (reaction rate with respect to one OH group) is:
15-80% is preferable, more preferably 20-45%
It is.

Further, as the o-quinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be used. That is, for example 1,2-
Known 1,2-quinonediazide compounds such as benzoquinonediazide sulfonic acid ester, 1,2-naphthoquinonediazide sulfonic acid ester, 1,2-benzoquinonediazide sulfonic acid amide, 1,2-naphthoquinonediazide sulfonic acid amide, more specifically "Light-Sensitive System" by J. Kosar.
ems”) pp. 339-352 (1965), John Wiley and Sons
& Sons (New York) and W.S. De Forest (New York).
“Photoresist” by T)
”) Volume 50 (1975), McGraw-Hill (Mc
1,2-benzoquinonediazide-4-sulfonic acid phenyl ester, 1,2-benzoquinonediazide-5-
Sulfonic acid phenyl ester, 1,2,1',2'-di-(benzoquinonediazide-4-sulfonyl)-dihydroxybiphenyl, 1,2-benzoquinonediazide-4
-(N-ethyl-N-β-naphthyl)-sulfonamide, 1,2-naphthoquinonediazide-4-sulfonic acid cyclohexyl ester, 1,2-naphthoquinonediazide-
5-sulfonic acid cyclohexyl ester, 1-(1,2
-naphthoquinonediazide-5-sulfonyl)-3,5-
Dimethylpyrazole, 1,2-naphthoquinonediazide
4-Sulfonic acid-4'-hydroxydiphenyl-4'-
Azo-β-naphthol ester, N,N-di-(1,2
-naphthoquinonediazide-5-sulfonyl)-aniline, 2'-(1,2-naphthoquinonediazide-4-sulfonyloxy)-1-hydroxy-anthraquinone, 1,
2-naphthoquinonediazide-4-sulfonic acid-2,4-
Dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-4-sulfonic acid-2,3,4-trihydroxybenzophenone ester, 2 moles of 1,2-naphthoquinonediazide-4-sulfonic acid chloride and 4,4'
- Condensate of 1 mole of diaminobenzophenone, 1,2-naphthoquinonediazide - Condensate of 2 moles of 4-sulfonic acid chloride and 1 mole of 4,4'-dihydroxy-1,1'-diphenylsulfone, 1,2-naphthoquinonediazide -4
- Condensate of 1 mol of sulfonic acid chloride and 1 mol of purprogalin, 1,2-naphthoquinonediazide-5-sulfonic acid-4'-hydroxydiphenyl-4'-azo-β-naphthol ester, 2'-(1,2- naphthoquinonediazide-5-sulfonyloxy)-1-hydroxy-anthraquinone, 1,2-naphthoquinonediazide-5-sulfonic acid-2,4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid-2
, 3,4-trihydroxybenzophenone ester, 1
, a condensate of 2 moles of 2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mole of 4,4'-diaminobenzophenone, 2 moles of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 4,4'-dihydroxy-1 ,1'-
Condensate of 1 mole of diphenylsulfone, condensate of 1 mole of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mole of purprogalin, 1,2-naphthoquinonediazide-5-(N-dihydroabiethyl)-sulfonamide, etc. Examples include the following 1,2-quinonediazide compounds. Also, Special Publication No. 37-1953, No. 37-36
No. 27, No. 37-13109, No. 40226126, No. 40-3801, No. 45-5604, No. 45-
No. 27345, No. 51-13013, Japanese Unexamined Patent Publication No. 1973-9
No. 6575, No. 48-63802, No. 48-6380
1,2-quinonediazide compounds described in each publication No. 3 can also be mentioned.

Among the above o-quinonediazide compounds, 1
, 2-benzoquinonediazide sulfonyl chloride or 1
, 2-naphthoquinonediazide sulfonyl chloride and a pyrogallol acetone condensation resin or an o-quinonediazide ester compound obtained by reacting 2,3,4-trihydroxybenzophenone is particularly preferred.

As the o-quinonediazide compound used in the present invention, each of the above compounds may be used alone, or
Two or more types may be used in combination.

The proportion of the o-quinonediazide compound used in the present invention in the photosensitive composition is 5 to 60% by weight.
is preferred, particularly preferably 10 to 50% by weight.

Examples of the alkali-soluble resin used in the photosensitive composition of the present invention include novolac resin, vinyl polymer having a phenolic hydroxyl group, and JP-A-55-578.
Examples include condensation resins of polyhydric phenols and aldehydes or ketones described in Japanese Patent No. 41. Examples of the novolak resin used in the present invention include phenol,
Formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensation resin as described in JP-A No. 55-57841, p- as described in JP-A-55-127553 Examples include copolycondensation resins of substituted phenol and phenol or cresol and formaldehyde.

The molecular weight (polystyrene standard) of the novolac resin is preferably such that the number average molecular weight Mn is 3.00×
102 to 7.50×103, weight average molecular weight Mw is 1.
00×103 to 3.00×104, more preferably Mn
is 5.00×102 to 4.00×103, Mw is 3.0
It is 0x103 to 2.00x104.

The above novolac resins may be used alone or in combination of two or more. The proportion of the novolak resin in the photosensitive composition of the present invention is 5 to 95%.
Weight%.

[0035] Furthermore, the vinyl polymer having a phenolic hydroxyl group used in the present invention is a polymer having a unit having a phenolic hydroxyl group in its molecular structure,
Polymers containing at least one structural unit represented by the following general formulas [II] to [VI] are preferred.

[0036]

embedded image [In the formula, R3 and R4 each represent a hydrogen atom, an alkyl group, or a carboxyl group, and preferably a hydrogen atom. R5 represents a hydrogen atom, a halogen atom, or an alkyl group, preferably a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R6 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom. A represents an alkylene group optionally having a substituent that connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer of 0 to 10, and B has a substituent. represents a phenylene group that may have a substituent or a naphthylene group that may have a substituent. ] The polymer used in the photosensitive composition of the present invention preferably has a copolymer type structure,
Examples of monomer units that can be used in combination with the structural units represented by the general formulas [II] to [VI] include ethylene, propylene, isobutylene,
Ethylenically unsaturated olefins such as butadiene and isoprene; styrenes such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene; acrylic acids such as acrylic acid and methacrylic acid; e.g. itaconic acid and maleic acid. acids, unsaturated aliphatic dicarboxylic acids such as maleic anhydride, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α - Esters of α-methylene aliphatic monocarboxylic acids such as methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, and ethyl ethacrylate, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide, such as acrylanilide, Anilides such as p-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, e.g. vinyl acetate,
Vinyl esters such as vinyl propionate, vinyl benzoate, vinyl butyrate, etc., such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, β-
Vinyl ethers such as chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene, 1,1
-dimethoxyethylene, 1,2-dimethoxyethylene,
1,1-dimethoxycarbonylethylene, 1-methyl-
Ethylene derivatives such as 1-nitroethylene, e.g.
There are N-vinyl monomers such as vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidene, and N-vinylpyrrolidone. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above-mentioned monomers, esters of aliphatic monocarboxylic acids and nitriles are preferred because they exhibit excellent performance for the purpose of the present invention.

These monomers may be bound in the polymer used in the present invention in either a block or random manner.

The proportion of the vinyl polymer used in the present invention in the photosensitive composition is 0.5 to 70% by weight.

As the vinyl polymer used in the present invention, the above-mentioned polymers may be used alone or in combination of two or more. Moreover, it can also be used in combination with other polymer compounds.

Next, the diazo resin used in the present invention will be explained. The diazo resin used in the present invention is not particularly limited, and various photosensitive diazo resins can be used.

Examples of photosensitive diazo resins include diazo resins represented by condensates of aromatic diazonium salts and carbonyl-containing compounds, especially formaldehyde; among these, alkali-soluble or organic solvent-soluble diazo resins are used. is preferred.

[0043] As the condensed diazo resin, for example, p
- A diazo resin inorganic salt which is an organic solvent-soluble reaction product of a condensate of diazodiphenylamine, formaldehyde or acetaldehyde, and hexafluorophosphate or tetrafluoroborate, as described in U.S. Pat. No. 3,300,309 Said condensates as described and sulfonic acids such as para-toluenesulfonic acid or its salts, phosphinic acids such as benzenephosphinic acid or its salts, hydroxyl-containing compounds such as 2,4-dihydroxybenzophenone, 2-hydroxy- Examples include organic solvent-soluble diazo resin organic acid salts which are reaction products such as 4-methoxybenzophenone.

The diazo resin is contained in the photosensitive layer in an amount of 1 to 70% by weight,
In particular, it is desirable that the content be 3 to 60% by weight.

In the present invention, when the purpose is to have good developability and sensitivity, an aromatic compound having at least one organic group of a carboxyl group and a hydroxyl group, and an aromatic diazonium compound are used. A co-condensed diazo resin containing as a constituent unit can be more preferably used. Moreover, this and the above-mentioned diazo resin may be used in combination. When used together, the ratio of co-condensed diazo resin:condensed diazo resin is preferably in the range of 5 to 95:95 to 5 (weight % ratio), more preferably 3.
0-70: 70-30.

The aromatic compound having at least one organic group of a carboxyl group and a hydroxyl group is, for example, an aromatic ring substituted with at least one carboxyl group and/or an aromatic ring substituted with at least one hydroxyl group. The molecule contains an aromatic ring, and the carboxyl group and hydroxyl group may be substituted with the same aromatic ring.

The aromatic ring is preferably an aryl group, such as a phenyl group or a naphthyl group.

[0048] The carboxyl group or hydroxyl group described above may be bonded directly to the aromatic ring or may be bonded via a linking group.

In the above, the number of carboxyl groups bonded to one aromatic ring is preferably 1 or 2, and the number of hydroxyl groups bonded to one aromatic ring is preferably 1 to 3.

Examples of the linking group include alkylene groups having 1 to 4 carbon atoms.

[0051] Specific examples of the aromatic compounds containing carboxyl and/or hydroxyl groups mentioned above include benzoic acid, o-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, phthalic acid, and terephthalic 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-methoxybenzoyl)benzoic acid, 4-(p-methylanilino)benzoic acid, 4-phenylsulfonylbenzoic acid, phenol, (o, m, p
)-cresol, xylenol, resorcin, α-methylresorcin, (o, m, p)-methoxyphenol,
m-ethoxyphenol, catechol, phloroglycin, 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, 4-methylsalicylic acid, 6-methylsalicylic acid, 4-ethylsalicylic acid, 6-propylsalicylic acid, 6-laurylsalicylic acid, 6-stearylsalicylic acid, 4,6-dimethylsalicylic acid, p -Hydroxybenzoic acid, 2-methyl-4
-Hydroxybenzoic acid, 6-methyl-4-hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,4-dihydroxy-6-methylbenzoic acid, 2,6 -dihydroxybenzoic acid, 2,6-dihydroxy-4-benzoic acid, 4-chloro-2,6-dihydroxybenzoic acid, 4-methoxy-2,
6-dioxybenzoic acid, gallic acid, phloroglucincarboxylic acid, 2,4,5-trihydroxybenzoic acid, m-galloyl gallic acid, tannic acid, m-benzoyl gallic acid, m-(p-toluyl) gallic acid , protocatechuoyl-gallic acid, 4,6-dihydroxyphthalic acid, (2,4
-dihydroxyphenyl)acetic acid, (2,6-dihydroxyphenyl)acetic acid, (3,4,5-trihydroxyphenyl)acetic acid, p-(hydroxymethylbenzoic acid, p-hydroxyethylbenzoic acid, 4-(p-hydroxy phenyl)methylbenzoic acid, 4-(o-hydroxybenzoyl)benzoic acid, 4-(2,4-dihydroxybenzoyl)
Benzoic acid, 4-(p-hydroxyphenoxy)benzoic acid, 4-(p-hydroxyanilino)benzoic acid, bis(3
-carboxy-4-hydroxyphenyl)amine, 4-
(p-hydroxyphenylsulfonyl)benzoic acid, 4-
(p-hydroxyphenylthio)benzoic acid, etc. Among these, particularly preferred are salicylic acid, p-
These are hydroxybenzoic acid, p-methoxybenzoic acid, and metachlorobenzoic acid.

As the aromatic diazonium compound,
Diazonium salts listed in Japanese Patent Publication No. 49-48001 can be used, but diphenylamine-
4-diazonium salts are particularly preferred.

Diphenylamine-4-diazonium salts are derived from 4-amino-diphenylamines, and such 4-amino-diphenylamines include 4-amino-diphenylamine, 4-amino-3-methoxy-diphenylamine, , 4-amino-2-methoxy-diphenylamine, 4'-amino-2-methoxy-diphenylamine, 4'-amino-4-methoxy-diphenylamine, 4-amino-3-methyldiphenylamine, 4-amino-3-β- Examples include hydroxy-ethoxydiphenylamine, 4-amino-diphenylamine-2-sulfonic acid, 4-amino-diphenylamine-2-carboxylic acid, 4-amino-diphenylamine-2'-carboxylic acid, and particularly preferably 4-amino-diphenylamine-2'-carboxylic acid. -3-methoxy-diphenylamine and 4-amino-diphenylamine.

The above-mentioned co-condensed diazo resin and condensed diazo resin can be prepared by known methods such as Photographic Science and Engineering (Photo.
Sci. Eng. ) Volume 17, page 33 (1973)
, U.S. Patent No. 2,063,631, U.S. Patent No. 2,679,
According to the methods described in each specification of No. 498, diazonium salts and aldehydes,
For example, it can be obtained by polycondensing paraformaldehyde, acetaldehyde, benzaldehyde or ketones such as acetone and acetophenone with or without addition of an aromatic compound having carboxyl and hydroxyl groups.

[0055] Further, these aromatic compounds having carboxyl groups and/or hydroxyl groups, aromatic diazo compounds, and aldehydes or ketones can be freely combined with each other, and two or more of each may be mixed and co-condensed. Good too.

In the co-condensed diazo resin, the molar ratio of the aromatic compound having at least one of a carboxyl group and a hydroxyl group to the aromatic diazo compound is 1.
:0.1-0.1:1, preferably 1:0.5-0.2
:1, more preferably 1:1 to 0.2:1.

Condensation or co-condensation is usually carried out by combining an aromatic compound or aromatic diazo compound having at least one of a carboxyl group and a hydroxyl group with an aldehyde or a ketone. The molar ratio of aldehydes or ketones to the sum of the aromatic compounds and aromatic diazo compounds is 1:0.6 to 1.2, preferably 1:0.7 to
This is carried out by charging the mixture at a temperature of 1.5 and reacting at a low temperature for a short period of time, for example, about 3 hours.

As the counter anion for the diazo resin according to the present invention, an anion that stably forms a salt with the diazo resin and makes the resin soluble in an organic solvent is used. These counter-anions include organic carboxylic acids such as decanoic acid and benzoic acid, organic phosphoric acids such as phenyl phosphoric acid, and sulfonic acids, with typical examples being methanesulfonic acid, chloroethanesulfonic acid, dodecanesulfonic acid, etc. , benzenesulfonic acid, toluenesulfonic acid, mesitylenesulfonic acid, anthraquinonesulfonic acid, 2-hydroxy-4-
Aliphatic and aromatic sulfonic acids such as methoxybenzophenone-5-sulfonic acid, hydroxysulfonic acid, 4-acetylbenzenesulfonic acid, dimethyl-5-sulfoisophthalate, 2,2',4,4'-tetrahydroxybenzophenone, Aromatic compounds containing hydroxyl groups such as 1,2,3-trihydroxybenzophenone and 2,2',4-trihydroxybenzophenone, halogenated Lewis acids such as hexafluorophosphoric acid and tetrafluoroboric acid, ClO4
, IO4, and other perhalogen acids, but are not limited thereto. Among these, particularly preferred are hexafluorophosphoric acid and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid.

The co-condensed diazo resin of the present invention can have any molecular weight by varying the molar ratio of each monomer and the condensation conditions. Those having a molecular weight of about 400 to 10,000 can be used, but those having a molecular weight of about 800 to 5,000 are suitable.

In the photosensitive composition containing the diazo resin of the present invention, it is preferable to use the following polymer compound together with the above diazo resin.

[0061] These polymer compounds can function as a binder when forming a photosensitive composition together with the diazo resin.

[0062] The polymer compound that can be used in the present invention is of any type, and includes, for example, polyamide, polyether, polyester, polycarbonate, polystyrene, polyurethane, polyvinyl chloride and its copolymers, polyvinyl butyral resin, polyvinyl formal resin. , Sierrac, epoxy resin, phenolic resin, and acrylic resin.

Preferably, it is a copolymer obtained by copolymerizing monomers selected from the following (1) to (12). (1) Monomers having aromatic hydroxyl groups, such as N-(4
-hydroxyphenyl) acrylhumide or N-(4
-hydroxyphenyl) methacrylamide, o-, m-
, p-hydroxystyrene, o-, m-, p-hydroxyphenyl-acrylate or -methacrylate. (2) Monomers having aliphatic hydroxyl groups, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate. (3) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, or their anhydrides. (4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, acrylic acid-
(substituted) alkyl acrylates such as 2-chloroethyl, 2-hydroxyethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate; (5) Methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 2
-Hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-
(Substituted) alkyl methacrylates such as dimethylaminoethyl methacrylate. (6) Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide,
N-ethylacrylamide, N-hexylacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N
- Acrylamides or methacrylamides such as phenylacrylamide. (7) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether. (8) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate. (9) Styrenes such as styrene, α-methylstyrene, methylstyrene, and chloromethylstyrene. (10) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone. (11) Olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene. (12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc.

Furthermore, a monomer that can be copolymerized with the above monomer may be copolymerized. It also includes, but is not limited to, copolymers obtained by copolymerizing the above monomers, modified with glycidyl methacrylate, glycidyl acrylate, and the like.

More specifically, a copolymer having a hydroxyl group using the monomers listed in (1) and (2) above is preferred, and a copolymer having an aromatic hydroxyl group is more preferred.

Further, polyvinyl butyral resin, polyurethane resin, polyamide resin, epoxy resin, novolak resin, natural resin, etc. may be added to the above copolymer, if necessary.

Particularly preferred as the polymer compound used in the photosensitive composition of the present invention are the following copolymers. That is, in the molecular structure, (a) the structural unit having a carboxyl group is 2 mol% or more, preferably 3 to 20 mol%, (
b) 1 to 50 mol% of a structural unit having an alcoholic hydroxyl group and/or a structural unit having a phenolic hydroxyl group, (c) the following general formula IA

[0068]

embedded image [In the formula, R11 represents a hydrogen atom or an alkyl group. ] 5 to 40 mol% of the structural unit represented by (d) the following general formula IIA

[0069]

embedded image [In the formula, R12 represents a hydrogen atom, a methyl group, or an ethyl group, and R13 represents an alkyl group having 1 to 12 carbon atoms or an alkyl-substituted aryl group. A polymer compound containing 25 to 60 mol % of the structural unit represented by the formula is preferable.

Specific examples of monomers forming the structural unit having an alcoholic hydroxyl group (b) include the following general formula III described in Japanese Patent Publication No. 7364/1983.
Examples include (meth)acrylic acid esters and (meth)acrylamides represented by A.

[0071]

embedded image [In the formula, R14 represents a hydrogen atom or a methyl group, R15 represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, and n represents an integer of 1 to 10. ] Specific examples of these (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, etc. Specific examples of acrylamides include N-methylol (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, and the like. Preferably it is 2-hydroxyethyl (meth)acrylate.

Specific examples of monomers forming the structural unit having a phenolic hydroxyl group (b) above include N-(4-hydroxyphenyl)-(meth)acrylamide, N-(2-hydroxyphenyl) -(meth)acrylamides such as (meth)acrylamide and N-(4-hydroxynaphthyl)-(meth)acrylamide; o
-, m- or p-hydroxyphenyl (meth)acrylate; o-, m- or p-hydroxystyrene, and the like. Preferably, o-, m- or p-hydroxyphenyl (meth)acrylate, N-(4-hydroxyphenyl)-(meth)acrylamide, more preferably N-(4-hydroxyphenyl)-(meth)acrylamide. etc.

The structural unit having an alcoholic hydroxyl group and/or the structural unit having a phenolic hydroxyl group is
In the polymer compound, 1 to 50 mol%, preferably 5 to 3
It is selected from the range of 0 mol%.

Specific examples of monomers forming the structural unit represented by the general formula IA include acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, etc. It will be done. Preferred are acrylonitrile and methacrylonitrile. The proportion of the structural unit formed from the monomer contained in the molecule of the polymer compound is preferably selected from the range of 5 to 40 mol%, more preferably 15 to 23 mol%.

Specific examples of monomers forming the structural unit represented by the general formula IIA include ethyl acrylate, ethyl methacrylate, propyl acrylate, butyl acrylate, amyl acrylate, amyl methacrylate, hexyl acrylate, octyl acrylate, -chloroethyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate and the like. The unit formed from the monomer preferably accounts for 25 to 60 mol%, more preferably, in the polymer compound.
It is selected from the range of 35 to 60 mol%.

[0076] The above structural units are not limited to units formed from the monomers listed as specific examples.

[0077] In the photosensitive composition using the diazo resin of the present invention, when the above-mentioned polymer compounds are used together, these are added to the solid content of the photosensitive composition constituting the photosensitive layer according to the present invention. Preferably 30 to 99% by weight of the polymer compound
, more preferably 50 to 95% by weight.

A compound that generates an acid and/or a free radical upon exposure to light may be added to the photosensitive composition of the present invention. Various known compounds can be used as compounds that generate acids and/or free radicals upon exposure to light, including oxadiazole compounds having trihaloalkyl groups, triazine compounds, pyrone compounds, diazonium salts, o-
Naphthoquinonediazide-4-sulfonic acid chloride and the like can be preferably used.

Among these, trihaloalkyl compounds and diazonium salt compounds represented by the following general formula [A] and general formula [B], respectively, are preferably used.

[0080]

embedded image In the formula, Xa represents a trihaloalkyl group having 1 to 3 carbon atoms, W represents each atom of N, S, Se, P, and C, and Z
represents each atom of O, N, S, Se, P, and C. Y has a chromophore group and represents a nonmetallic atomic group necessary for cyclizing W and Z. However, the ring formed by the nonmetallic atomic group may have the above-mentioned Xa. General formula [B] Ar-+N2X- In the formula, Ar represents an aryl group, and X represents a counter ion of an inorganic compound.

Compounds represented by general formula [A] include:
Specifically, compounds (1), (2), (3), (7), which are exemplified on page 3 of JP-A-60-138593,
Oxadiazole compounds having a benzofuran ring such as (9), page 1 of JP-A-54-74728, pages 3-4
Compound No. exemplified in the table. 1~No. An oxadiazole compound represented by 17. Furthermore, JP-A-55-777
Publication No. 42, Publication No. 60-3626, Publication No. 60-177
Examples thereof include oxadiazole compounds described in JP-A No. 340 and JP-A No. 61-143748.

Also, 4-(2,4-dimethoxy-4-styryl)-6-trichloromethyl-2-pyrone compound described in JP-A-53-36223. 2,4-bis-(trichloromethyl)-6-methoxystyryl-S- described in JP-A-48-36281
Examples include triazine compounds and 2,4-bis-(trichloromethyl)-6-p-dimethylaminostyryl-S-triazine compounds.

[0083] Furthermore, for example, Special Publication No. 60-46700
No. 62-44258, Special Publication No. 1-28369,
JP-A-58-87553, JP-A No. 60-239736,
No. 60-239473, No. 61-151644, No. 62-24242, No. 62-58241, No. 62-
No. 175735, No. 63-58440, No. 63-29
Examples include compounds described in various publications such as No. 8339.

On the other hand, as the diazonium salt compound, a diazonium salt which generates a strong Lewis acid upon exposure to light is preferred, and as the counter ion moiety, a counter ion of an inorganic compound is recommended. As specific examples of such compounds, the anion moiety of the diazonium salt is at least one of phosphorus fluoride ion, arsenic fluoride ion, antimony fluoride ion, antimony chloride ion, tin chloride ion, bismuth chloride ion, and zinc chloride ion. Examples include aromatic diazonium salts, and preferably hexafluorophosphate of paradiazodiphenylamine.

In addition to the above-mentioned materials, the photosensitive composition of the present invention may optionally contain plasticizers, surfactants, organic acids, acid anhydrides, long-chain aliphatic carboxylic acids, dyes, pigments such as pigments, etc. Stabilizers, thermal polymerization inhibitors, sensitizers, coatability improvers, etc. can be added.

Furthermore, in order to improve the oil sensitivity of the photosensitive composition used in the present invention, for example, p
-tert-butylphenol formaldehyde resin, p-n-octylphenol formaldehyde resin,
Alternatively, resins in which these resins are partially esterified with an o-quinodine azide compound can be added.

The photosensitive composition of the present invention can be applied to photosensitive lithographic printing plates, etc. by dissolving each of these components in a solvent, applying the solution to the surface of a suitable support and drying it to form a photosensitive layer. materials can be obtained.

Solvents that can be used to dissolve each component of the photosensitive composition of the present invention include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate, methyl carbitol, and ethyl carbitol. , diethylene glycol ethers and/or esters such as dimethyl carbitol, diethyl carbitol, and methyl carbitol acetate, dimethyl formamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, and methyl ethyl ketone. These solvents can be used alone or in combination of two or more.

In the present invention, it is preferable to use alkyl ethers of dialkylene glycol, such as dimethyl carbitol, alone or in combination with other solvents. At this time, it is preferable that the amount of the alkyl ether of dialkylene glycol to be mixed exceeds 15% by weight. Furthermore, the content is preferably over 40% by weight, particularly preferably 55% by weight or more.

The coating method used for coating the photosensitive composition of the present invention on the surface of the support includes conventionally known methods, such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, and blade coating. Coating, curtain coating, etc. are possible. At this time, the coating amount varies depending on the application, but is preferably 0.5 to 5.0 g/m2 in terms of solid content.

[0091] Supports used when obtaining a photosensitive lithographic printing plate using the photosensitive composition of the present invention include metal plates such as aluminum, zinc, steel, and copper, as well as metal plates such as chromium, zinc, copper, nickel, Examples include metal plates plated or vapor-deposited with aluminum, iron, etc., paper, plastic films and glass plates, paper coated with resin, paper covered with metal foil such as aluminum, plastic films treated to make them hydrophilic, etc. can.

When obtaining a photosensitive lithographic printing plate, it is preferable to use as a support an aluminum plate which has been subjected to surface treatments such as graining, anodizing and, if necessary, sealing.

[0093] Known methods can be applied to these treatments.

Examples of the graining treatment include a mechanical method and an electrolytic etching method. Examples of the mechanical method include a ball polishing method, a brush polishing method, a polishing method using liquid honing, and a buffing method. The various methods described above can be used alone or in combination depending on the composition of the aluminum material. Preferred is a method using electrolytic etching.

[0095] Electrolytic etching can be performed using phosphoric acid, sulfuric acid, hydrochloric acid,
It is carried out in a bath containing one or more inorganic acids such as nitric acid. After the graining treatment, if necessary, desmut treatment is performed with an aqueous alkali or acid solution, neutralized, and washed with water.

[0096] The anodic oxidation treatment is carried out by electrolyzing using an aluminum plate as an anode using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc. as an electrolytic solution. The amount of anodic oxide film formed is 1 to 50 m
g/dm2 is appropriate, preferably 10 to 40 mg/dm2.
It is dm2. The amount of anodic oxide coating can be determined by, for example, applying an aluminum plate to a phosphoric acid chromic acid solution (85% phosphoric acid solution: 35%
, chromium (IV) oxide (prepared by dissolving 20 g in 1 liter of water) to dissolve the oxide film, and determine the weight change of the plate before and after the film is dissolved.

Specific examples of the sealing treatment include hot water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition to this, for aluminum supports,
It is also possible to perform subbing treatment using an aqueous solution of a water-soluble polymer compound or a metal salt such as fluorinated zirconate. Further, immersion treatment can also be carried out using a sodium nitrite aqueous solution.

A photosensitive lithographic printing plate to which the photosensitive composition of the present invention is applied can be developed by a conventional method. For example, a relief image can be obtained by exposing a transparent original image having a line image, halftone image, etc. in close contact with a photosensitive surface, and then removing the photosensitive layer in the non-image area using a suitable developer. As a light source suitable for exposure, a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a carbon arc lamp, etc. are used, and as a developer used for development, an alkaline aqueous solution is preferably used, for example,
Alkaline aqueous solutions include aqueous solutions of sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, sodium carbonate, potassium carbonate, and the like. The concentration of the alkaline aqueous solution at this time varies depending on the photosensitive composition and the type of alkali, but is generally in the range of 0.1 to 10% by weight,
Further, an anionic surfactant, an amphoteric surfactant, or an organic solvent such as alcohol can be added to the alkaline aqueous solution if necessary.

0099

[Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. Example 1 [Preparation of aluminum plate] An aluminum plate with a thickness of 0.24 mm (material 1050, tempered H16) was degreased in a 5% by weight aqueous sodium hydroxide solution at 60°C for 1 minute. In a liter of 0.5 molar hydrochloric acid aqueous solution, temperature: 25°C, current density: 60 A/dm2, treatment time: 30
Electrolytic etching treatment was performed under conditions of seconds. Next, after desmutting in a 5% by weight aqueous sodium hydroxide solution at 60°C for 10 seconds, anodization was performed in a 20% by weight sulfuric acid solution at a temperature of 20°C, a current density of 3A/dm2, and a treatment time of 1 minute. processed. Furthermore, hot water sealing treatment was performed for 20 seconds with hot water at 80° C. to produce an aluminum plate as a support for a lithographic printing plate. [Coating of photosensitive composition coating liquid] A photosensitive composition coating liquid of the following composition was applied to the aluminum plate prepared as above using a rotary coater, and dried at 90°C for 4 minutes to obtain a positive photosensitive composition. A lithographic printing plate (Sample 1) was prepared.

[0100] The thickness of the dry coating film of this sample was 2.2 g/
It was m2. [Composition of photosensitive composition coating solution] (1) Cocondensation resin of phenol, m-cresol, p-cresol, and formaldehyde (the molar ratio of each of phenol, m-cresol, and p-cresol is 2.0: 4.8:3.
2, Mw=6000, Mw/Mn=5.0
)
6.9g (2) Below formula 9

2.3g

[0101]

[Chemical formula 9] (3) The following chemical formula 10
0.07
g

[0102]

[Chemical formula 10] (4) The following chemical formula 11
0.07
g

[0103]

[Chemical formula 11] (5) Methyl cellosolve
100ml
Furthermore, in the above photosensitive composition coating solution composition, the type and amount of compound (4) added were changed as shown in Table 1, and photosensitive lithographic printing plate samples 2 to 8 were obtained in the same manner.

Compound G and Compound H used in the photosensitive composition coating solution are as follows. Compound G: Isomeric hydroxyphenylazodiphenylamine mixture prepared as follows (mixture described in Japanese Patent Publication No. 55-25653) Phenol (18.8 g, 0.2 mol) was dissolved in 2000 ml of 4% aqueous sodium hydroxide. , water 30
A solution of diphenylamine-4-diazonium hydrogen sulfate (58.6 g, 0.2 mol) in 0 ml and 300 ml of water
A solution of sodium carbonate (21.2 g, 0.2 mol) in the solution was added at the same time with stirring at the same rate. The pH was kept at approximately 10 during this step. The resulting brown precipitate was separated, washed with water, and dried in a vacuum dryer to obtain an isomeric hydroxyphenylazodiphenylamine mixture.

The above isomeric hydroxyphenylazodiphenylamine mixture was confirmed by thin film chromatography to be a mixture of three isomeric hydroxyphenylazodiphenylamines, all of which are acid/base indicators.

The final yield of dry product was 49.0 g (85
%) and melted at 100-105°C. Compound H: The diazonium salt of 2,4-dinitro-6-chloro-benzene was converted into 2-methoxy-5-acetylamino-
A blue azo dye obtained by coupling with N,N-diethylaniline. (Unexamined Japanese Patent Publication No. 58-87553
(blue azo dye described in the publication) [Evaluation of sensitivity] Each of the obtained photosensitive lithographic printing plate samples 1 to 8 was coated with a step tablet for sensitivity measurement (No. 2 manufactured by Eastman Kodak Company, density difference 0. 21 levels of gray scale (gray scale of 15 each) were placed in close contact with each other and exposed from a distance of 90 cm using a 2KW metal halide lamp (Idolfin 2000 manufactured by Iwasaki Electric Co., Ltd.) as a light source. Next, this sample was developed at 27° C. for 20 seconds using a developer prepared by diluting SDR-1 (manufactured by Konica Corporation) six times with water.

Sensitivity was defined as the exposure time at which the 3.0 step of the step tablet was completely cleared. [Evaluation of dye residue] The reflection density of the non-image area of the sample exposed and developed under the conditions used to determine the sensitivity was measured using a densitometer (Sakura Densitometer PDA-65),
The difference in density (ΔD1) with respect to the aluminum support plate before coating the photosensitive composition coating solution was determined, and this was used to evaluate the residual dye. The smaller ΔD1 means the less dye remains. [Evaluation of visible image quality after exposure] The difference in density between the exposed and unexposed areas of the sample before development was exposed under the above conditions and was visually evaluated under a yellow lamp to evaluate the visible image quality after exposure. Further, measurement was performed using a densitometer (Sakura Densitometer PDA-65), and the absolute value ΔD2 of the density difference between the exposed area and the unexposed area was determined. ΔD
The larger the value of 2, the better the exposure visible image quality. [Evaluation of exposure visible image quality during storage] Photosensitive lithographic printing plate samples 1 to 8 were incubated at 55°C, 20% RH, and at 40°C, 80% RH.
Each was stored for one week under these conditions. These samples were evaluated for exposure visibility using the method described above.

[0108] The results of the above evaluation are also shown in Table 1.

[0109]

[Table 1] In Table 1, the exposure visible image quality (visual observation) is divided into 5 stages, with ◎ indicating very good exposure visible image quality and XX indicating no exposure visible image quality at all. ◎、○、△、×、×
Evaluations were made and displayed in the order of ×.

[0110] As is clear from Table 1, sample 1 of the present invention
-5 have excellent exposed visible image properties, high sensitivity, and improved color retention after development and storage stability.

Example 2 A photosensitive plate was prepared in exactly the same manner as in Samples 1 to 8 of Example 1, except that the compound (2) was changed to the following compound A, and the compound (3) was changed to the following compound B. Printing plate samples 9-16
It was created.

[0112] These samples were evaluated in the same manner as in Example 1 for sensitivity, dye residue, and visible image quality upon exposure immediately after coating and during storage.
Similar results were obtained.

[0113]

[Chemical formula 12]

Example 3 A photosensitive plate was prepared in exactly the same manner as in Samples 1 to 8 of Example 1, except that the compound (2) was changed to the following compound C, and the compound (3) was changed to the following compound D. Printing plate sample 17-2
4 was created.

[0115] These samples were evaluated in the same manner as in Example 1 for sensitivity, dye residue, and exposure visible image quality immediately after coating and during storage. Samples 17 to 21 of the present invention showed the same results as Example 1. was gotten.

[0116]

[Chemical formula 13]

Example 4 [Preparation of sample of photosensitive lithographic printing plate] On the support prepared in Example 1, a photosensitive composition coating solution having the following composition was coated using a spin coater, and the coating solution was heated at 90°C. The plate was dried for 1 minute to obtain a negative photosensitive lithographic printing plate sample 25 having a dry coating thickness of 1.7 g/m 2 . [Photosensitive composition coating liquid composition] (1) Copolymer *E
5.0
g(2) Diazo resin *F
005
g(3) Julimar AC-10L (manufactured by Nippon Pure Chemical Industries)
0.1g (4) Below chemical formula 14

0.1g

[0118]

[Chemical formula 14] (5) Methyl cellosolve
100ml
Further, in the above photosensitive composition coating solution composition, the type and amount of compound (4) added were changed as shown in Table 2 to obtain photosensitive lithographic printing plate samples 26 to 32.

Copolymer *E used in photosensitive composition coating solution
and diazo resin *F are as follows. Copolymer *E; N-(p-hydroxyphenyl)methacrylamide/acrylonitrile/ethyl acrylate/
Copolymer with composition of methacrylic acid = 10/23/60/7 (Mw = 6000) Diazo resin *F; following formula 15

[0120]

[Chemical formula 15]

[Evaluation of Sensitivity] Each of the obtained photosensitive lithographic printing plate samples 25 to 32 was coated with a step tablet for sensitivity measurement (No. 2 manufactured by Eastman Kodak Company, density difference 0.
21 levels of gray scale (15 each) in close contact, 2
Exposure was carried out from a distance of 90 cm using a kW metal halide lamp (Idol Fin 2000 manufactured by Iwasaki Electric Co., Ltd.) as a light source. Next, this sample was developed at 27° C. for 20 seconds using a developer prepared by diluting SDN-21 (manufactured by Konica Corporation) 4 times with water. Sensitivity was defined as the exposure time at which the 4.0 step of the step tablet was completely solid.

[Evaluation of dye residue] Photosensitive planographic printing plate 25
A negative transparent original image of a line drawing and halftone image was brought into close contact with the photosensitive layer No. 32, and exposed and developed under the above conditions. The obtained sample was printed on a printing machine (Heidel GTO) using coated paper printing ink (New Bright Beni, manufactured by Toyo Ink Mfg. Co., Ltd.) and dampening water (SEU-3, 2.5%, manufactured by Konica Corporation). After printing 1,000 sheets, use a 25x magnifying glass to examine the dark areas of the halftone image (halftone area ratio: 97).
%) was evaluated for the state of halftone dot reproduction. (If the dye remains in the non-image area, the halftone dot reproducibility will deteriorate.) Evaluation: ○...Reproduced (no coloring) ×: Not reproduced (there is coloring)

[Evaluation of visible image quality after exposure] The difference in density between the exposed area and the unexposed area of the sample before development which was exposed under the above conditions was visually evaluated under a yellow lamp to evaluate the visible image quality after exposure. Further, measurement was performed using a densitometer (Sakura Densitometer PDA-65), and the absolute value ΔD2 of the density difference between the exposed area and the unexposed area was determined. It is shown that the larger ΔD2 is, the better the exposure visible image quality is.

[Evaluation of exposure visible image quality during storage] Photosensitive lithographic printing plate samples 25 to 32 were heated at 55°C, 20% RH, and 4
Each was stored for one week under the conditions of 0° C. and 80% RH. These samples were evaluated for exposure visibility using the method described above.

[0125] The results of the above evaluation are also shown in Table 2.

[0126]

[Table 2]

In Table 2, the exposure visibility (visual observation) is as follows:
The state with very good exposure visibility is ◎, and the state with no exposure visibility is XX, and the overall condition is divided into 5 stages: ◎, ○.
The results were evaluated and displayed in the order of , Δ, ×, and XX.

[0128]

Effects of the Invention The photosensitive composition of the present invention has excellent exposure and visible image properties, high sensitivity, and improved color retention after development and storage stability.

Claims (1)

[Claims] 1. A photosensitive material containing at least (a) an arylazo compound and/or a salt thereof having a carboxyl group and/or a sulfonic acid group as a substituent, and (b) an o-quinonediazide compound or a diazo resin. Composition.