JPH0470834A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To obtain a photosensitive compsn. giving a photosensitive planographic printing plate having superior developability, sensitivity and print ing resistance by incorporating specified cocondensed diazo resin and a specified org. high molecular compd. CONSTITUTION:Cocondensed diazo resin contg. an arom. diazonium compd. and a compd. represented by formula I as structural units is formed. In the formula I, R<1>-R<5> are substituents, at least one of them is OH, R<6>-R<10> are identical with R<1>-R<5>, X is a divalent bonding group and n is 0 or 1. The diazo resin and an org. high molecular compd. contg. phenolic OH and/or alcoholic OH in the molecule are incorporated into a photosensitive compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive composition. The photosensitive composition of the present invention can be used, for example, to constitute an intense light layer of a lithographic printing plate.

[Background of the invention]

Various photosensitive compositions have been proposed in the past, and various photosensitive lithographic printing plates (hereinafter sometimes referred to as PS plates) are constructed using these compositions.

Photosensitive printing plates are generally manufactured by coating a photosensitive composition on a support such as an aluminum plate. The photosensitive printing plate is
For example, in the case of a negative type, it is usually irradiated with active light such as ultraviolet rays through a negative image, etc., and the irradiated areas are polymerized or crosslinked to make these areas insoluble in the developer, and then developed. The non-irradiated area is eluted into the developer,
Generally, each portion is used as an image area that repels water and receives oil-based ink, and a non-image area that receives water and repels oil-based ink.

In this case, the photosensitive composition is particularly negative-type P
In the S plate, a photoreceptor containing a diazo resin has been commonly used.

A condensate of an aromatic diazonium compound and formaldehyde is known as a general diazo resin used in such a negative PS plate. However, these were not necessarily satisfactory in terms of alkali solubility (that is, developability), sensitivity, stiffness resistance when used in PS plates, etc. On the other hand,
As described in Japanese Patent Publication No. 1983-78340, using a diazo cocondensation resin,
Although it has been proposed to use high molecular weight condensed diazo resins, none of them have been able to solve the above problems.

The present invention solves the above-mentioned problems and has good sensitivity, good alkali solubility, and good physical properties. Therefore, when used, for example, for forming an angry lithographic printing plate, it has good developability, sensitivity, stiffness resistance, etc. The object of the present invention is to provide a photosensitive composition that provides excellent properties.

[Means for solving problems]

The above objects of the present invention have been achieved by a photosensitive composition containing the following cocondensed diazo resin (A) and the following organic polymer compound (B).

(A) aromatic diazonium compound and the following general formula (1)
A co-condensed diazo resin containing a compound having the structure represented by as a structural unit.

General formula (1) R1-R5 represent substituents, at least one of which represents 0)1 group. R6-R1+1 has the same meaning as R1-R5. X represents a divalent bonding group.

n is O or 1.

(B) Phenolic OH and/or alcoholic OH
An organic polymer compound containing in the molecule.

The present invention will be explained in more detail below.

First, the above (A) contained in the photosensitive composition of the present invention
The component diazo resin (hereinafter sometimes referred to as "the diazo resin of the present invention") will be described.

The diazo resin of the present invention comprises an aromatic diazonium compound,
It is a co-condensed diazo resin containing a compound having a structure represented by the above general formula (I) as a structural unit.

In general formula (1), at least one of RI, RS and at least one of R6 to RIG are OH
Each of these groups preferably has 1 to 2 OH groups.

Represents either υ 1z or -〇-. Here R1+, )
71! is H or an alkyl group or an aryl group.

The diazo resin of the present invention has an aromatic diazonium unit in its molecule as a structural unit, and various aromatic diazonium compounds can be used as the aromatic diazonium compound that provides the diazonium structural unit. For example, those listed in Japanese Patent Publication No. 49-48001 can be used. Particularly preferred are diphenyl-4-diazonium salts. Such diphenyl-4-diazonium salts are derived from 4-aminodiphenylamines, and examples of such 4-amino-diphenylamines include 4-amino-diphenylamine, 4-amino-3-methoxydiphenylamine, 4-amino-diphenylamine, and 4-amino-diphenylamine. Amino-2-methoxy-diphenylamine, 4'
-amino-2-methoxydiphenylamine, 4'-amino-4-methoxy-diphenylamine, 4-amino-3
-methyldiphenylamine, 4-amino-3-ethoxydiphenylamine, 4-amino-3-β-hydroxy-
Ethoxydiphenylamine, 4-aminodiphenylamine-2-sulfonic acid, 4-amino-diphenylamine-
2-carboxylic acid, 4-amino-diphenylamine-2'
-carboxylic acids, and particularly preferably used are 3-methoxy-4-aminodiphenylamine and 4-amino-diphenylamine.

On the other hand, examples of compounds that impart the structure represented by general formula (I) to the diazo resin of the present invention include compounds having the structure represented by general formula (I), such as 2,2' dihydroxybenzophenone, 4.4 '-dihydroxybenzophenone, 0
．． 0'-biphenol, p, p'-biphenol, 1.
3-bis(4-hydroxyphenoxy)benzene, ■,
4-bis(3-hydroxyphenoxy)benzene, bis(3-hydroxyphenyl)amine, 2,2-bis(4
-hydroxyphenyl)butane, bis(4-hydroxyphenyl)ether, 2.2-bis(4-hydroxyphenyl)hexafluoropropane, bis(0-hydroxyphenyl)methane, bis(p-hydroxyphenyl)methane, 2 [Bis(4-hydroxyphenyl)methyl]benzyl alcohol, 2.2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfone, diphenolic acid, 3. Examples include 3'dihydroxydiphenyl ether, 2,2'4,4'-tetrahydroxydiphenylmethane, and the like.

Among the above, particularly preferred are 4,4'-dihydroxybenzophenone, bis(P-hydroxyphenyl)methane, bis(4-hydroxyphenyl sulfide), bis(3-hydroxyphenyl)amine, bis(4-hydroxyphenyl) ) ether, p, p'-biphenol,
3,3'-dihydroxydiphenyl ether, 2.2'
, 4°4'-tetrahydroxydiphenylmethane, and the like.

The above-mentioned co-condensed diazo resin can be produced by various methods, such as known methods such as Photographic Science &amp;
Engineering (Photo, Sci, Eng,) Vol. 17, p. 33 (1973), U.S. Patent No. 2,063
A diazonium salt, a compound giving a structural unit of general formula (I) and a carbonyl compound in sulfuric acid, phosphoric acid or hydrochloric acid according to the methods described in the specifications of No. 631 and No. 2.679,498. It can be obtained by polycondensing aldehydes (eg, paraformaldehyde, acetaldehyde, benzaldehyde, etc.) or ketones (eg, acetone, acetophenone, etc.).

The molar ratio of the compound providing the structural unit of general formula (I) and the aromatic diazonium compound is preferably 1:0.
1-0.1:1, more preferably 1:0.5-0.2:
1, more preferably 1:1 to 0.2:1. Also,
The total of the compound giving the structure of general formula (1) and the aromatic diazonium compound and aldehydes or ketones,
The co-condensed diazo resin is prepared by charging at a molar ratio of preferably 1:0.6 to 1.2, more preferably 1:0.7 to 1.5, and reacting at a low temperature for a short period of time, for example, about 3 hours. can get.

The counter anion of the diazo resin includes an anion that stably forms a salt with the diazo resin and makes the resin soluble in an organic solvent. Those that form such anions include organic carboxylic acids such as decanoic acid and benzoic acid, organic phosphoric acids such as phenylphosphoric acid, and sulfonic acids; typical examples include methanesulfonic acid, Chloroethanesulfonic acid, dodecanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, mesitylenesulfonic acid, and anthraquinonesulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, hydroxysulfonic acid, 4-acetylhenzenesulfonic acid , aliphatic and aromatic sulfonic acids such as dimethyl-5-sulfoisophthalate, 2°2',4.4'-tetrahydroxybenzophenone, 1,2.3-1-dihydroxybenzophenone, 2.2',4- ) Aromatic compounds containing hydroxyl groups such as dihydroxybenzophenone, halogenated Lewis acids such as hexafluorophosphoric acid and tetrafluoroboric acid, CI
Examples include perhalogen acids such as O, 10, and the like. However, it is not limited to this. Among these, particularly preferred are hexafluorophosphoric acid and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid.

The above-mentioned co-condensed diazo resin can have an arbitrary molecular weight by varying the molar ratio of each monomer and the condensation conditions. In the present invention, in general, those having a molecular weight of about 400 to 10,000 can be effectively used, more preferably about 800 to 5,000.
is appropriate.

Next, the organic polymer compound which is the component (B) contained in the photosensitive composition of the present invention will be explained.

The polymer compound that can be used in the present invention may be of any type as long as it contains phenolic 01 (and/or alcoholic OH in the molecule), but for example, the following compounds may be used. Yes, that is,
Examples of the polymer compounds that can be used include polyamide, polyether, polyester, polycarbonate, polystyrene, polyurethane, polyvinyl chloride and its copolymers, polyvinyl butyral resin, polyvinyl formal resin, shellac, epoxy resin, phenol resin, acrylic resin, etc. It will be done.

Preferably, one or more monomers selected from (1) among the monomers shown in (1) to (12) below, and (
Copolymers with monomers selected from those shown in 2) to (12) can be mentioned.

(1) Hetamine-1 having an aromatic hydroxyl group, for example, N(4-
hydroxyphenyl)acrylamide 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 2,2-hydroxyethyl methacrylate.

(3) Acrylic acid, methacrylic acid, maleic anhydride,
α, β unsaturated carboxylic acids such as itaconic acid and itaconic anhydride.

(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, and 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,
Acrylamides or methacrylamides such as N-ethylacrylamide, N-hexylacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylamide, and N-ethyl-N-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, methacrylatel, etc.

Furthermore, a monomer that can be copolymerized with the above monomer may be copolymerized. Further, the copolymerization pair obtained by copolymerization of the above monomers may be, for example, glycidyl methacrylate,
It also includes, but is not limited to, those modified with glycidyl acrylate and the like.

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

Particularly preferred as the polymer compound containing phenolic OH and/or alcoholic OH in the molecule used in the present invention are the following copolymers.

That is, in the molecular structure, (a) a structural unit having an alcoholic hydroxyl group and/or
or 1 to 50 structural units having a phenolic hydroxyl group.
mol%, (b) 2 mol% of structural units having carboxyl groups
(C) represented by the following general formula IA-CHZ-C-...IAN (wherein, R11 represents a hydrogen atom or an alkyl group). 5 to 40 mol% of structural units, (d) the following general formula IIA - CHZ -C-... IIACOOR
” (In the formula, R12 represents a hydrogen atom, a methyl group, or an ethyl group, and R12 represents an alkyl group or an alkyl-substituted aryl group having 2 to 12 carbon atoms.) 25 to 60 moles of the structural unit represented by % is preferred.

Specific examples of the monomer forming the structural unit having an alcoholic hydroxyl group in (a) above include Japanese Patent Publication No. 52-736
Examples include (meth)acrylic acid esters and acrylamides, such as the compounds shown in the following general formula n[A, as described in No. 4.

C8! -C-・・・・・・・・・I[[ACOO+CH
ICHO→, H RIS In the formula, R+4 represents a hydrogen atom or a methyl group, RIS represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, and n represents an integer of 1 to 10.

Examples of (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxypentyl (meth)acrylate.
Examples of acrylamides include N-methylol(meth)acrylamide, N-meth)acrylate, etc.
-Hydroxyethyl (meth)acrylamide and the like.

Preferably it is 2-hydroxyethyl (meth)acrylate.

In addition, examples of monomers forming the structural unit having a phenolic hydroxyl group (a) include N-(4-hydroxyphenyl)-(meth)acrylamide, N-(
2-hydroxyphenyl)-(meth)acrylamide,
(meth)acrylamide monomers such as N-(4-hydroxynaphthyl)-(meth)acrylamide; O-,
Examples include m- or p-hydroxyphenyl (meth)acrylate monomer; om- or p-hydroxystyrene monomer. Preferably, o-, m- or p-hydroxyphenyl (meth)acrylate monomer, N-(4-hydroxyphenyl)(meth)acrylamide monomer, more preferably N-(4-hydroxyphenyl)-(meth) It is an acrylamide monomer.

The structural unit having an alcoholic hydroxyl group and/or the structural unit having a phenolic hydroxyl group is preferably 1 to 50 mol%, more preferably 5 to 50 mol%, in the polymer compound.
It is selected from a range of 30 mol%.

Examples of monomers having a cyano group in the side chain that form the structural unit represented by the general formula IA include acrylonitrile, methacrylonitrile, 2-pentenenitrile, and 2-pentenenitrile.
Examples include methyl-3-butenenitrile, 2-cyanoethyl acrylate, o-, m-p-cyanostyrene, and the like. Preferred are acrylonitrile and methacrylonitrile.

The proportion of the structural unit having a cyano group in the side chain contained in the molecule of the polymer compound is preferably selected from the range of 5 to 40 mol%, more preferably 15 to 35 mol%.

Examples of monomers having a carboxy ester group in the side chain that form the structural unit represented by general formula I[A include ethyl acrylate, ethyl methacrylate, propyl acrylate, butyl acrylate, amyl acrylate, amyl methacrylate, and hexyl acrylate. ,
Examples include octyl acrylate, 2-chloroethyl acrylate, 2-hydroxyethyl acrylate, and glycidyl acrylate. The unit formed from the monomer preferably accounts for 25 to 60 mol% in the polymer compound,
More preferably, it is selected from the range of 35 to 60 mol%.

Note that each of the above structural units is not limited to units formed from the monomers listed as specific examples.

The polymer compound according to the present invention contained in the photosensitive composition of the present invention and other polymer compounds contained as necessary preferably have a weight average molecular weight of 20,
000 or more and soo or ooo or less, and is preferably a lipophilic polymer compound. More preferably, the weight average molecular weight is 30,000 or more and 300,000
These are as follows.

The above molecular weights and the molecular weights of the polymers shown in this specification are based on polystyrene standards by GPC.

That is, the weight average molecular weight can be measured by GPC (gel permeation chromatography). Calculation of number average molecular weight MN and weight average molecular weight MW is based on Morio Tsuge, Tatsuya Miyabayashi, and Masayuki Tanaka, “Journal of the Chemical Society of Japan” 8.
By the method described on pages 00 to 805 (1972),
The test shall be performed by leveling the peaks of the oligomer region (by connecting the center lines of the peaks and valleys).

The polymer compound as component (B) contained in the photosensitive composition of the present invention is preferably usually contained in an amount of 40 to 99% by weight, more preferably 50 to 95% by weight in the solid content of the photosensitive composition. let Further, the co-condensed diazo resin which is component (A) is similarly preferably contained in an amount of usually 1 to 60% by weight, more preferably 3 to 30% by weight.

The photosensitive composition of the present invention can contain any organic acid, inorganic acid, or acid anhydride.

Although the organic acid is arbitrary, monocarboxylic acids and polycarboxylic acids having at least one carboxyl group are preferred. Malic acid, tartaric acid, and polyacrylic acid (such as those commercially available under the trade name Jurimer) can be preferably used.

As the inorganic acid, phosphoric acid or the like can be used. Acid anhydrides are also optional, and include those derived from aliphatic/aromatic monocarboxylic acids such as acetic anhydride, propionic anhydride, benzoic anhydride, succinic anhydride, maleic anhydride, glutaric anhydride, phthalic anhydride, etc. , those derived from aliphatic/aromatic dicarboxylic acids, and the like.

The photosensitive composition of the present invention can contain a dye, particularly a dye that changes color from colored to colorless or changes color upon processing. Preferably, a pigment that changes from colored to colorless is contained.

In carrying out the present invention, the following can be mentioned as dyes that can be preferably used.

That is, for example, Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.)
, Crystal Violet, Brilliant Green, Ethyl Hiolesotho, Methyl Violet, Methyl Green, Erythrosin B, Pesic Tsuksin, Malachite Green, Oil Red, m-Cresol Purple, Rhodamine B1 Auramine, 4-P-dimethylaminophenyl imino naphthoquine , triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthine-based, iminonaphthoquinone-based, azomethine-based, or anthraquinone-based pigments such as cyano-p-diethylaminophenyl acetanilide change color from colored to colorless or to a different color. Examples of pigments include:

Particularly preferred are triphenylmethane-based and diphenylmethane-based dyes, and more preferred are triphenylmethane-based dyes, with Victoria Viewer Blue BO (Victoria Viewer Blue BO) being particularly preferred.

The above-mentioned color changing agent is usually added in the photosensitive composition from about 0.5 to about 10
It is preferable to contain the amount by weight, more preferably about 1% by weight.
Contain up to 5% by weight.

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

In addition, alkyl ethers (e.g., ethyl cellulose, methyl cellulose), fluorosurfactants, nonionic surfactants (e.g., Pluronic L-64 (manufactured by Asahi Denka Corporation)) to improve coating properties, and Plasticizers for imparting flexibility and abrasion resistance (e.g. 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), oil sensitivity of image area Sensitizers (for example, half esters of styrene-maleic anhydride copolymer with alcohol as described in JP-A No. 55-527), stabilizers [for example, phosphoric acid, phosphorous acid, etc.] , 19 acids (citric acid, oxalic acid, benzenesulfonic acid, naphthalenesulfonic acid, 4-methoxy-2
hydroxybensophenone-5-sulfonic acid, tartaric acid, etc.)]. The amount of these additives added varies depending on the object and purpose of use, but is generally preferably 0.01 to 30% by weight based on the total solid content.

Next, a case where a photosensitive lithographic printing plate is constructed using the photosensitive composition of the present invention will be described. A photosensitive lithographic printing plate can be constructed by forming a photosensitive layer made of the photosensitive composition of the present invention on a support.

In order to place the photosensitive composition on a support, predetermined amounts of the co-condensed diazo resin, polymer compound, and other additives used as necessary are added to a suitable solvent (methyl A coating solution of the photosensitive composition is prepared by dissolving the photosensitive composition in (cellosolve, ethyl cellosolve, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethyl formamide, dimethyl sulfoxide, water, or a mixture thereof, etc.), and this is coated on a support. , drying means can be used. The concentration of the photosensitive composition during coating is preferably in the range of 1 to 50% by weight.

In this case, the coating amount of the photosensitive composition is preferably approximately 0.2 to 10 g/rr? It is sufficient to set the degree.

In the photosensitive lithographic printing plate, various supports can be used to coat the photosensitive composition to form the photosensitive layer. Particularly preferred is an aluminum plate. However, if an aluminum plate is used without treatment, there are problems in that the adhesion of the photosensitive composition is poor and the photosensitive composition decomposes. In order to eliminate this problem, various proposals have been made in the past.

For example, a method in which the surface of an aluminum plate is grained and then treated with a silicate (US Pat. No. 2,714°066), a method in which the surface is treated with an organic acid salt (US Pat. No. 2,714,
No. 066), treatment with phosphonic acids and their derivatives (U.S. Pat. No. 3,220,832), treatment with potassium hexafluorozirconate (U.S. Pat. No. 2
, 946,683), a method of anodizing, and a method of treating with an aqueous solution of alkali metal silicate after anodizing (US Pat. No. 3,18L461).

In a preferred embodiment of the present invention, the surface of the aluminum plate (including the alumina laminate) is degreased and then grained by a brush polishing method, a ball polishing method, a chemical polishing method, an electrolytic etching method, etc. It is preferably grained using an electrolytic etching method that produces deep and uniform grains. The anodizing treatment is carried out, for example, in an aqueous solution of an inorganic salt such as phosphoric acid, chromic acid, boric acid, or sulfuric acid, or an organic acid such as oxalic acid, or a mixture of two or more of these acids, preferably in an aqueous sulfuric acid solution. This is done by passing an electric current through an aluminum plate as an anode. The amount of anodized film is preferably 5 to 60+ag/drrf, more preferably 5 to 30+ag/drrf.

When carrying out the pore sealing treatment in carrying out the present invention, it is preferable to add a sodium silicate aqueous solution with a concentration of 0.1 to 3% at a temperature of 8.
This treatment is carried out by immersion for 10 seconds to 2 minutes at 0-95°C. More preferably, it is then treated by immersing it in water at 40 to 95°C for 10 seconds to 2 minutes.

The photosensitive lithographic printing plate of the present invention can be exposed and developed by conventional methods. That is, for example, a negative leaf image can be obtained with respect to the original image by exposing the transparent original image having a line image, halftone image, etc. to light, and then developing with an aqueous developer.

Light sources suitable for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, and the like.

Any developer can be used to develop the photosensitive composition of the present invention and/or the photosensitive lithographic printing plate using the photosensitive composition, as long as it can develop the photosensitive composition.

Preferably, a developer containing a specific organic solvent, an alkaline agent, and water as necessary components can be used.

The specific organic solvent herein refers to one that can dissolve or swell the non-exposed area (non-image area) of the layer made of the photosensitive composition of the present invention when contained in the developer.
Moreover, the solubility in water at room temperature (20"C) is 1.
0% by weight or less of organic solvent is preferred. Such organic solvents only need to have the above-mentioned characteristics, and are not limited to the following, examples of which include ethyl acetate, propyl acetate, Butyl acetate, amyl acetate, benzyl acetate, ethylene glycol motuputyl acetate, butyl lactate,
Carboxylic acid esters such as butyl levulinate; ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone; ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n - alcohols such as amyl alcohol and methyl amyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; halogenated hydrocarbons such as methylene dichloride, ethylene dichloride, and monochlorobenzene. One or more of these organic solvents may be used. Among these organic solvents, ethylene glycol monophenyl ether and benzyl alcohol are particularly effective. Further, the content of these organic solvents in the developer is preferably about 1
-20% by weight, and particularly preferable results are obtained when the content is 2-10% by weight.

On the other hand, preferred alkaline agents contained in the developer include (a) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium dibasic or tertiary phosphate, and sodium carbonate; , inorganic alkaline agents such as ammonium, (b) mono, di or trimethylamine, mono, di or triethylamine, mono or diisopropylamine, n-butylamine, mono, di or triethanolamine, mono, di or triisopropanolamine, Examples include organic amine compounds such as ethyleneimine and ethylenediamine.

The content of these alkaline agents in the developer is usually 0.
It is preferably 0.05 to 4% by weight, more preferably 0.5 to 2% by weight.

Further, in order to further improve storage stability, rigidity resistance, etc., it is preferable to include a water-active sulfite in the developer. Such water-soluble sulfites are preferably alkali or alkaline earth metal salts of sulfite, such as sodium sulfite, potassium sulfite, lithium sulfite, magnesium sulfite, and the like. The content of these sulfites in the developer composition is usually preferably 0.05 to 4% by weight, more preferably 0.1 to 1% by weight.

If such a developer is brought into contact with the photosensitive composition after development and exposure, or is rubbed with the developer, the temperature will be approximately room temperature to 4.
After 10 to 60 seconds at 0°C, the photosensitive composition in the non-exposed areas of the photosensitive composition layer is completely removed without adversely affecting the exposed areas.

〔Example〕

Examples of the present invention will be described below. As a matter of course, the present invention is not limited to the following examples.

In each of the following examples, (B
) is an organic polymer compound corresponding to component (A), and is an alkali-soluble/swellable polymer compound (1) (2), and a co-condensed diazo resin of the present invention that corresponds to component (A) as a photosensitive substance ( Since diazo resin (1) and comparative diazo resin (2) were used, their synthesis will be explained first.

Person 1 8N-(4-hydroxyphenyl)methacrylamide 1
7.7 g, methacrylic acid 8.6 g, acrylonitrile 10.6 g, ethyl acrylate 60.0
g.

and 1.64 g of azobisisobutyronitrile were dissolved in 130 mf of an acetone-methanol 1:1 mixed solution,
After purging with nitrogen, the mixture was heated at 60°C for 6 hours.

After the reaction was completed, the reaction solution was poured into water 51 with stirring, and the resulting white precipitate was filtered and dried to obtain 87 g of polymer compound (1).

When the molecular weight of this polymer compound (1) was measured by gel permeation chromatography (hereinafter abbreviated as GPC, polystyrene standard), the weight average molecular weight was found to be 82,000. Calculation of weight average molecular weight MW by GPC (gel permeation chromatography method) is based on the book written by Morio Tsuge, Tatsuya Miyabayashi, and Masayuki Tanaka.
This can be carried out by the method described in "Journal of the Chemical Society of Japan," pages 800 to 805 (1972), by leveling the peaks of the oligomer 95 region (connecting the center lines of the peaks and valleys).

A 2-hydroxyethyl methacrylate) 13.0 g,
Methacrylic acid 8.6g, acrylonitrile 10.6g
g, 60.0 g of ethyl acrylate, and 1.64 g of azobisisobutyronitrile were dissolved in 130 mj2 of a 1:1 acetone-methanol mixed solution, the atmosphere was purged with nitrogen, and the mixture was heated at 60''C for 6 hours.

Thereafter, in the same manner as for polymer compound (1), 83 g of polymer compound (2) was obtained.

When the molecular weight of this polymer compound (2) was measured by GPC, the weight average molecular weight was 67,000.

Diazo Ll 21.75 g of p-diazodiphenylamine sulfate and 4.7 g of p,p'-biphenol were cooled in water to 90 g.
of concentrated sulfuric acid. To this reaction solution, 2.7 g of paraformaldehyde was slowly added.

At this time, the addition was carried out so that the reaction temperature did not exceed 10°C. Thereafter, stirring was continued for 2 hours under water cooling.

This reaction mixture was added dropwise to If's ethanol under water cooling, and the resulting precipitate was filtered off. After washing the precipitate with ethanol, the precipitate was dissolved in 200 cal of pure water, and an aqueous solution containing 10.5 g of zinc chloride was added to this solution. After filtering the resulting precipitate, it was washed with ethanol and
It was dissolved in pure water of cal. Add 13.7 g to this liquid.
An aqueous solution in which ammonium hexafluorophosphate was dissolved was added, and the resulting precipitate was filtered off, washed with water and ethanol, and then dried at 25°C for 3 days to obtain diazo resin 1.

14.5g of P-diazodiphenylamine sulfate,
It was dissolved in 40 g of concentrated sulfuric acid under water cooling. 1 in this reaction solution
．． 0.5 g of rose formaldehyde was slowly added.

At this time, the addition was carried out so that the reaction temperature did not exceed 10°C. Thereafter, stirring was continued for 2 hours under water cooling. This reaction mixture was added dropwise to 500 m 12 of ethanol under water cooling, and the resulting precipitate was filtered off.

After washing the precipitate with ethanol, the precipitate was dissolved in 1001 pure water, and an aqueous solution in which 6.8 g of zinc chloride was dissolved was added to this solution. The resulting precipitate was filtered off, washed with ethanol, and dissolved in 150 ml of pure water. An aqueous solution containing 8 g of ammonium hexafluorophosphate was added to this solution, and the resulting precipitate was filtered, washed with water and ethanol, and dried at 25°C for 3 days to obtain diazo resin 2. Ta.

Next, examples will be described together with comparative examples.

Examples 1 and 2 and Comparative Example 1 Table 1 was prepared on a grained, anodized aluminum plate.
The photosensitive solution shown in
A photosensitive planographic printing plate sample was prepared.

A transparent negative original image was placed on each sample obtained in the margin below, and after exposure for 30 seconds from a distance of 60 cm using a 2 kW metal halide lamp, 2.
After being immersed in 7°CCl2O for 7 seconds, it was developed by rubbing lightly with absorbent cotton.

The sensitivity of each sample was compared based on the number of steps when exposing and developing the original image using a Konica step tablet.

Further, the obtained plates were printed using a Heidelberg GTO printing machine, and the developability was compared based on the degree of scumming.

Furthermore, the stiffness resistance was evaluated by comparing the number of sheets at the time when scratches were observed in the image area when printing was continued.

Each result is shown in Table-2.

From the results in Table 2, the samples obtained in Examples 1 and 2 were:
It can be seen that sensitivity and stiffness resistance can be significantly improved without reducing developability. On the other hand, the comparative sample was
Poor developability, sensitivity and stiffness resistance.

[Effects of the Invention] As described above, the present invention made it possible to obtain a photosensitive composition with excellent sensitivity and developability. Furthermore, by applying this photosensitive composition to a lithographic printing plate, a printing plate with excellent rigidity resistance could be obtained.

Claims (1)

[Claims] 1. A photosensitive composition comprising the following cocondensed diazo resin (A) and the following organic polymer compound (B). (A) aromatic diazonium compound and the following general formula (I
) A co-condensed diazo resin containing a compound having the structure represented by as a constituent unit. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ R^1 to R^5 represent substituents, at least one of which
One represents an OH group. R^6~R^1^0 is R^1~R
It is synonymous with ^5. X represents a divalent bonding group. n is 0 or 1. (B) Phenolic OH and/or alcoholic OH
An organic polymer compound containing in the molecule.