JPH02189545A - Production of planographic printing plate - Google Patents

Abstract

PURPOSE:To improve developability and plate wear without using a developer contg. an org. solvent by developing the photosensitive planographic printing plate having a photosensitive layer contg. a diazo compd., lipophilic high-polymer compd. and development accelerator on a base body by an aq. alkaline soln. having >=pH 12 after image exposing. CONSTITUTION:The photosensitive planographic printing plate having the photosensitive layer contg. the diazo compd., the lipophilic high-polymer compd. and the development accelerator on the base body is subjected to image exposing and is then developed by the aq. alkaline soln. which has >=pH 12 and contains substantially no org. solvents. While the conventional known compds. are usable as the diazo compd., a diazo resin as represented by the condensation product of an arom. diazonium salt and, for example, active carbonyl-contg. compd., more particularly, formaldenyde, is included and above all, the diazo resin soluble in org. solvents is more preferable. The planographic printing plate which is free from the toxicity, smells and the danger to fires and has the good developability is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a lithographic printing plate, and particularly to a negative photosensitive lithographic printing plate.

(Prior art) Photosensitive printing plates are generally produced by coating a photosensitive composition on a support such as an aluminum plate, irradiating active light such as ultraviolet rays through a negative image, and polymerizing or crosslinking the irradiated areas. The areas that are not irradiated with light are eluted into the developer, and each area is made into an image area that repels water and receives oil-based ink, and a non-image area that accepts water and repels oil-based ink. It can be obtained by

As the photosensitive composition in this case, a diazo resin such as a condensate of p-diazodiphenylamine and formaldehyde is used, and as the developer, one containing an organic solvent and an alkaline agent has been widely used.

(Problems to be Solved by the Invention) However, organic solvents are generally toxic, have an odor, and have a risk of fire, and also have many disadvantages such as being subject to BOD regulations for waste liquid, and are expensive ( There is a problem with becoming.

However, on the other hand, the present inventors have found that simply removing the organic solvent from the developer may result in insufficient developability.

(Means for Solving the Problems) As a result of repeated studies to solve the above problems based on this knowledge, the present inventors have developed an alkaline developer having a pH of 12 or more that does not substantially contain organic solvents. Developed with an aqueous solution,
In addition, in this case, the inventors discovered that it is important to include a development accelerator in the photosensitive layer of the printing plate, and arrived at the present invention.

That is, the gist of the present invention is that after imagewise exposure of a photosensitive lithographic printing plate having a photosensitive layer containing a diazo compound, a lipophilic polymer compound, and a development accelerator on a support, a photosensitive lithographic printing plate having a photosensitive layer containing a diazo compound, a lipophilic polymer compound, and a development accelerator is prepared, after imagewise exposure. The present invention relates to a method for producing a lithographic printing plate, which is characterized by developing with an alkaline aqueous solution.

(Specific Structure of the Invention) To explain the present invention, the present invention relates to a method for producing a lithographic printing plate, and the diazo compound contained in the photosensitive composition of the lithographic printing plate may be any conventionally known diazo compound. Examples which can be used include diazo resins represented by condensates of aromatic diazonium salts and, for example, active carbonyl-containing compounds, especially formaldehyde, among which diazo resins soluble in organic solvents are preferred.

Examples of the diazo resin include diazo resin inorganic salts which are organic solvent-soluble reaction products of a condensate of p-diazodiphenylamine and formaldehyde or acetaldehyde, and hexafluorophosphate or tetrafluoroborate;
Further, as described in U.S. Pat. , 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, or a salt thereof, and organic solvent-soluble diazo resin organic acid salts.

Similarly, diazo resin is 1 in the photosensitive layer for Kuon.
The content is desirably 70% by weight, particularly 3 to 60% by weight.

Other diazo resins that can be suitably used in the present invention include aromatic compounds having at least one organic group of at least one carboxyl group and at least one hydroxyl group; diazonium compounds;
Preferably, it is a (co)condensate containing an aromatic diazonium compound as a structural unit.

The above-mentioned aromatic compound having a carboxyl group and/or a hydroxyl group contains in the molecule an aromatic ring substituted with at least one carboxyl group and/or an aromatic ring monosubstituted with at least one hydroxyl group. In this case, the carboxyl group and the hydroxyl group may be substituted with the same aromatic ring.

Preferable examples of the aromatic ring include aryl groups such as phenyl and naphthyl groups.

Furthermore, the above carboxyl group or hydroxyl group may be bonded directly to the aromatic ring or may be bonded via a joint.

In the above case, 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. Furthermore, examples of joints include alkylene groups having 1 to 4 carbon atoms.

Specific examples of the above-mentioned aromatic compounds containing carboxyl groups and/or hydroxyl groups include benzoic acid, 0-
Chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, phthalic acid, 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, 2-methylresorcin, (o, m
, p)-methoxyphenol, m-ethoxyphenol, catechol, phloroglycin, p-hydroxyethylphenol, naphthol, pyrogallol, hydroquinone, p-hydroxybenzyl alcohol, 4-chlororesorcin, biphenyl 4,4'-diol, etc.

2.4-benzenetriol, bisphenol A12,
4-dihydroxybenzophenone, 2,3゜4-trihydroxybenzophenone, p-hydroxyacetophenone, 4.4-dihydroxydiphenyl ether, 4.4
'-dihydroxydiphenylamine, 4.4'-dihydroxydiphenylsulfidocumylphenol, (
01m,p)-chlorophenol, (o,m,p)-bromophenol, salicylic acid, 4-methylsalicylic acid,
6-methylsalicylic acid, 4-ethylsalicylic acid, 6-propylsalicylic acid, 6-laurylsalicylic acid, 6-stialylsalicylic 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-cyhydroxy-4-benzoic acid, 4-chloro-2 , 6 dihydroxybenzoic acid, 4-methoxy-2,6-dioxybenzoic acid, gallic acid, phloroglucincarboxylic acid, 2,4.5
-) Lihydroxybenzoic acid M, m-caroyl gallic acid, tannic acid, m-benzoyl gallic acid, m-(p-)
gallic acid, protocatechuoyl-gallic acid, 4
, 6-dihydroxyphthalic acid, (2,4-dihydroxyphenyl l: acid, (2,6-dihydroxyphenyl)acetic acid, (3,4,5-1-dihydroxyphenyl)acetic acid,
p-hydroxymethylbenzoic acid, p-hydroxyethylbenzoic acid, 4-(p-hydroxyphenyl)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-
Examples include 4-hydroxyphenyl)amine, 4-(p-hydroxyphenylsulfonyl)benzoic #4 (p-hydroxyphenylthio)benzoic acid, and particularly preferred among these are salicylic acid, p-hydroxybenzoic acid, and P-hydroxybenzoic acid. Methylbenzoic acid and metachlorobenzoic acid.

As the aromatic diazonium compound constituting the structural unit of the above-mentioned co-condensed diazo resin, diazonium salts such as those 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-diphenyl amines, including 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-ethoxy-diphenylamine , 4-amino-3
-β-hydroxy-ethoxydiphenylamine, 4-amino-diphenylamine-2-sulfonic acid, 4-amino-diphenylamine-2-carboxylic acid, 4-amino-diphenylamine-2'-carboxylic acid, etc., particularly preferably 3-amino-diphenylamine-2'-carboxylic acid, etc. -methoxy-4-amino-diphenylamine, 4-amino-diphenylamine.

The above-mentioned co-condensed diazo resin can be prepared by a known method, for example, Photographic Science and Engineering (Photo, Sci, Eng.) Vol. 17, No. 33.
According to the method described in Makoto (1973), U.S. Pat.
diazonium salts in sulfuric, phosphoric or hydrochloric acids, aromatic compounds and aldehydes having carboxyl and/or hydroxyl groups, such as paraformaldehyde, acetaldehyde, benzaldehyde or ketones;
For example, it can be obtained by polycondensing acetone and acetophenone.

Furthermore, these aromatic compounds, aromatic diazo compounds, and aldehydes or ketones having carboxyl groups and/or hydroxyl groups in their molecules can be freely combined with each other, and two or more of each can also be mixed and co-condensed. It is possible.

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 to 0.1:1; preferably 1:0.5 to 0.2:1. , more preferably 1:1 to 0.
The ratio is 2:1. In this case, the molar ratio of the total of aromatic compounds and aromatic diazo compounds having at least one of a carboxyl group and a hydroxyl group to aldehydes or ketones is usually i:o, e to 1.2, preferably 1: A co-condensed diazo resin can be obtained by charging 0.7 to 1.5 and reacting at a low temperature for a short time, for example, about 3 hours.

The counter anion of the diazo resin used in the present invention is
It contains an anion that stably forms a salt with the diazo resin and makes the resin soluble in an organic solvent.

These 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-
Aliphatic and aromatic sulfonic acids such as methoxybenzophenone-5-sulfonic acid, hydroxysulfonic acid, 4-acetylbenzenesulfonic acid, dimethyl-5-sulfoisophthalate, 2.2', 4.4'-tetrahydroxybenzophenone, 1,2.3-) hydroxybenzophenone, 2.2', 4-) hydroxyl group-containing aromatic compounds such as lyhydroxybenzophenone, hexafluorophosphoric acid,
Halogenated Lewis acids such as tetrafluoroboric acid, C1,
Examples include, but are not limited to, perhalogen acids such as Oa and 104. Among these, particularly preferred are hexafluorophosphoric acid, 2-hydroxy-4
-methoxybenzophenone-5-sulfonic acid.

The above-mentioned co-condensed diazo resin can have any molecular weight by varying the molar ratio of each monomer and the condensation conditions, but in order to effectively serve the purpose of the present invention, Molecular weight is about 400 to io, ooo
Although any number can be used, preferably about 800 to 5,000 is suitable.

Moreover, as the lipophilic polymer compound in the present invention, a water-insoluble and alkali-soluble (or swellable) polymer is preferable.

The alkali-soluble polymers include the following (1) to 02.
Examples include copolymers whose structural units are monomers shown in ) and which usually have a molecular weight of 20,000 to 200,000.

(1) Acrylamides, methacrylamides, acrylic esters, and methacrylic esters having an aromatic hydroxyl group, such as N-(4-hydroxyphenyl)
Alkylamide or N-(4-hydroxyphenyl)methacrylamide, 0m-1p-hydroxystyrene, 0
-1m-1P-hydroxyphenyl-acrylate or methacrylate, (2) Acrylic esters and methacrylic esters having aliphatic hydroxyl groups, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, (3) Acrylic acid, methacrylate acids, α, β-unsaturated carboxylic acids such as maleic 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, glycidyl acrylate, N-dimethylaminoethyl acrylate, (5) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 4-hydroxybutyl methacrylate,
(Substituted) alkyl methacrylates such as glycidyl methacrylate and N-dimethylaminoethyl methacrylate; (6) acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethylacrylamide, N-hexyl methacrylamide, N-cyclohexyl Acrylamides or methacrylamides such as acrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N-phenylacrylamide, (7) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether , vinyl ethers such as propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, (8) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate, (9) styrene, α-methylstyrene, Styrenes such as methylstyrene and chloromethylstyrene, On) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone, (I+) Olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene, 02) N
-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylateril, 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-mentioned heptamers and modified with glycidyl methacrylate, glycidyl acrylate, and the like.

More specifically, a copolymer having a hydroxyl group containing the heptamers listed in (1) and (2) above is preferable, and a copolymer having an aromatic hydroxyl group is more preferable.

It is particularly preferable that the copolymer contains an α,β-unsaturated carboxylic acid listed in (3), and the preferable acid value of the copolymer is 10 to 100.

The preferred molecular weight of the above copolymer is 40,000 to 150,000.

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

This type of alkali-soluble polymer is usually contained in the solid content of the photosensitive composition in an amount of 40 to 99% by weight, preferably 50 to 95% by weight.

Particularly preferred as this alkali-soluble polymer is a polymer having methyl acrylate as a structural unit. In this case, more preferred 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 mol% of a structural unit having a phenolic hydroxyl group, (b) with the following formula (■), -CO, -C-...lN (wherein R1 represents a hydrogen atom or an alkyl group); 5 to 40 mol% of the structural unit represented, (C) 5 to 40 mol% of units formed from methyl acrylate, (d) the following - formula ■, -CH2-C-...■ C0OR' (in the formula , R2 represents a hydrogen atom, a methyl group, or an ethyl group, and R3 represents an alkyl group having 2 to 12 carbon atoms or an alkyl-substituted aryl group. ) A copolymer containing 2 to 30 mol% of a structural unit having a carboxyl group and having a weight average molecular weight of 50,000 to 200,000.

Specific examples of the monomer forming the structural unit having an alcoholic hydroxyl group include (meth)acrylic acid esters such as the compounds shown in the following general 2) as described in Japanese Patent Publication No. 52-7364, Examples include acrylamides.

R5 In the formula, R4 is a hydrogen atom or a methyl group, R5 is a hydrogen atom,
Methyl group, ethyl group or chloromethyl group, and n is 1
Indicates an integer between ~10.

Examples of (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, and examples of acrylamides include N -Methylol (meth)acrylamide, N
-Hydroxyethyl (meth)acrylamide and the like. Preferably it is 2-hydroxyethyl (meth)acrylate.

In addition, examples of the seven polymers forming a structural unit having a phenolic hydroxyl group include N-(4-hydroxyphenyl)-(meth)acrylamide, N-(2-hydroxyphenyl)-(meth)acrylamide, N-( Monomer of (meth)acrylamides such as 4-hydroxynaphthyl)-(meth)acrylamide: o-lm- or p-hydroxyphenyl (meth)acrylate monomer m: 〇-
Examples include m-or ha-hydroxystyrene monomers. Preferably, o-lm- or p-hydroxyphenyl (meth)acrylate monomer N-(4-hydroxyphenyl)-(meth)acrylamide monomer, more preferably N-(4-hydroxyphenyl)-
(meth)acrylamide monomer.

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

Examples of monomers having a cyano group in the side chain that form the structural unit represented by formula I include acrylonitrile, methachloronitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, 0 -1m-1p-cyanostyrene and the like. Preferred are acrylonitrile and methachloronitrile. The proportion of the structural unit having a cyano group in the side chain contained in the molecule of the polymer compound is selected from the range of 5 to 40 mol%, preferably 15 to 35 mol%.

The unit formed from methyl acrylate is 5 to 40 mol%, preferably 10 to 30 mol% in the polymer compound.
selected from the range.

Examples of the seven polymers having a carboxy ester group in the side chain that form the structural unit represented by formula (1) include ethyl acrylate, ethyl methacrylate, propyl acrylate, butyl acrylate, amyl acrylate,
amyl methacrylate, hexyl acrylate, octyl acrylate, 2-chloroethyl acrylate, 2-
and droxyethyl acrylate, glycidyl acrylate, and the like. The unit formed from the monomer accounts for 25 to 60 mol%, preferably 3% by mole in the polymer compound.
It is selected from the range of 5 to 60 mol%.

In addition, examples of the seven polymers forming a structural unit having a carboxyl group include methacrylic acid, acrylic acid, maleic anhydride, maleic acid, and the like. The amount of hexamer in the polymer compound is 2 to 30 mol%, preferably 5 to 15 mol%.
Selected from the range of mol%.

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

As a method for synthesizing the alkali-soluble polymer as a binder in the photosensitive composition, for example, azobisisobutyronitrile, azobisisobutyronitrile,
It is easily synthesized by a solution polymerization method using an initiator (0.1 to 4.0 mol %) such as benzoyl peroxide.

In the present invention, the development accelerator contained in the photosensitive layer of the lithographic printing plate together with the diazo compound and the lipophilic polymer compound includes acid anhydrides, long-chain alcohols, substances containing phenolic hydroxyl groups, celluloses, etc. . Furthermore, specific examples of these include acid anhydrides of saturated fatty acids such as glacial acetic anhydride, propionic anhydride, butyric anhydride, glu anhydride, talic acid, and lauric anhydride; aromatic anhydrides such as benzoic anhydride, phthalic anhydride, birometic anhydride, etc. Acid anhydrides of group carboxylic acids; acid anhydrides of unsaturated fatty acids such as itaconic anhydride; eugenol,
Long-chain alcohol necks such as nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, and pentadecanol; phenolic-011-containing substances such as ethyl gallate, ethyl benzoate, eugenol, guaiacol, isoeugenol, and PA resin;
Examples include celluloses such as hydroxypropyl cellulose terephthalate and hydroxypropyl cellulose benzoate, and only one type of these may be used.
You may use multiple types together. Particularly preferred are acid anhydrides of saturated fatty acids having 3 to 20 carbon atoms such as acetic anhydride, glutaric anhydride, and lauric anhydride, dodecanol,
These include long-chain alkyl alcohols having 10 to 14 carbon atoms such as tetradecanol, cellulose esters such as hydroxypropylcellulose terephthalate, and the like. These development accelerators are contained in the photosensitive composition in an amount of 0.1 to 20% by weight.
In particular, it is preferable to mix 1 to 10% by weight.

A dye can further be used in the photosensitive layer of the photosensitive lithographic printing plate in the present invention. The dye is used for the purpose of obtaining a visible image by exposure (exposed visible image) and a visible image after development.

As the dye, one that changes color tone by reacting with free radicals or acids can be preferably used.

Here, "the color tone changes" includes both a change from colorless to a colored tone, and a change from a color to colorless or a different colored tone. Preferred dyes are those that change color tone by forming salts with acids.

For example, Victoria Pure Blue BOHC 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 Violet, Methyl Violet, Methyl Green , erythrosin B1 basinin, malachite green, oil red, m-cresol purple, rhodamine B1 auramine, 4-P-diethylaminophenyl imino naphthoquinone, triphenylmethane type represented by cyano-p~diethylaminophenyl acetanilide, etc., diphenylmethane. type, oxazine type, xanthine type,
Iminonaphthoquinone-based, azomethine-based, or anthraquinone-based dyes are examples of color-changing agents that change color from colored to colorless or to a different colored tone.

On the other hand, examples of color changing agents that change from colorless to colored include leuco dyes and, for example, triphenylamine, diphenylamine, 0-chloroaniline, l,2゜3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, ρ, r-bis- Dimethylaminodiphenylamine, 1,2-dianilinoethylene, p, p', p''-tris-dimethylaminotriphenylmethane, p, p' -
Bis-dimethylaminodiphenylmethylimine, p, p
'p#-triamino-0-methyltriphenylmethane,
Examples include primary or secondary arylamine dyes represented by p,p'-bis-dimethylaminodiphenyl-4-anilinonaphthylmethane, p,p',p″L-triaminotriphenylmethane. .

Particularly preferably triphenylmethane and diphenylmethane dyes are effectively used, more preferably triphenylmethane dyes, especially Victoria Pure Blue BOH.

The amount of the above dye in the photosensitive composition is generally preferably about 0.5 to about 10% by weight, more preferably about 1 to 5% by weight.

Various additives can be further added to the photosensitive layer of the photosensitive lithographic printing plate of the present invention. For example, alkyl ethers (e.g. ethyl cellulose,
Methylcellulose), fluorine-based surfactants, nonionic surfactants (e.g., Pluronic L-64 (manufactured by Asahi Denka)), etc. are used as plasticizers to impart flexibility and abrasion resistance to the coating film. Butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid Examples of the oil-sensitizing agent for improving the oil-sensitivity of the image area include alcohol-based half esters of styrene-maleic anhydride copolymers described in JP-A No. 55-527. Examples of stabilizers include polyacrylic acid, tartaric acid, phosphoric acid, phosphorous acid, organic acids (acrylic acid, methacrylic acid, citric acid, oxalic acid, benzenesulfonic acid, naphthalenesulfonic acid, 4- Methoxy
2-hydroxybenzophenone-5-sulfonic acid, etc.). The amount of these additives added varies depending on the purpose for which they are used, but is generally 0.01 to 30% by weight based on the total solid content.

A photosensitive lithographic printing plate is obtained by applying the above photosensitive composition onto the surface of a support and drying it.

Examples of the coating solvent include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate, dimethyl formamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, and methyl ethyl ketone.

These solvents may be used alone or in combination of two or more.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, curtain coating, etc. can be used. The coating amount is preferably 0.2 to 10 g/bo in terms of solid content.

It is preferable to use an aluminum plate as the support for the photosensitive lithographic printing plate of the present invention. The surface is grained by electrolytic roughening in nitric acid or an electrolytic solution containing nitric acid as a main component, or in hydrochloric acid or an electrolytic solution containing hydrochloric acid as a main component, preferably further anodized and sealed if necessary. Use one that has undergone surface treatment such as hole treatment.

Electrolytic surface roughening is carried out by immersing an aluminum plate in a bath containing 0.1 to 0.5 mol/1, preferably 0.2 to 0.4 moQ/l of nitric acid or hydrochloric acid, and heating at 20 to 50°C.
1 Preferably a temperature of 25-40'C, a current density of 20-2
It is preferable to perform electrolytic etching at 0.00 A/dm2 for about 10 seconds to 3 minutes. After this graining treatment, if necessary, a desmut treatment is performed with an aqueous alkali or acid solution to neutralize the material, and the material is washed with water.

The anodizing treatment is performed 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 electrolyte. The amount of anodic oxide film formed is 1 to 50 μ/dm
2 is suitable, preferably lO~40■/dII+2
It is. Here, the amount of anodized film is determined by replacing the aluminum solution with a phosphoric acid chromic acid solution (35 ml of 85% phosphoric acid aqueous solution).
．． and 20 g of chromium (VI oxide) dissolved in water) to dissolve the oxide film, and measure the weight change of the plate before and after the film is dissolved.

Pore sealing treatments include boiling water treatment, steam treatment, sodium silicate treatment, dichromate aqueous solution treatment, and the like. In addition, water-soluble polymer compounds,
Subbing treatment can also be performed using an aqueous solution of a metal salt such as fluorinated zirconate.

The photosensitive lithographic printing plate thus obtained can be used by a known method. Typically, a negative film is brought into close contact with a photosensitive printing plate, exposed to light using an ultra-high pressure mercury lamp, metal halide lamp, etc., and developed using various known developers to obtain a printing plate. The lithographic printing plate produced in this way can be used in sheet-fed and off-wheel printing presses.

That is, by exposing to light through a transparent original having line images, halftone images, etc., and then developing with an aqueous developer,
A negative relief image is obtained for the original image. Light sources suitable for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, and the like.

The developer used in the development of the photosensitive lithographic printing plate in the present invention is an alkaline aqueous solution containing substantially no organic solvent.

"Substantially no organic solvent" means that the organic solvent is not contained in such an amount as to impair the above-mentioned sanitary and safety effects, and - 1% by weight or less in the developer composition for boat fishing. If so, there is no problem.

In the present invention, the preferred organic solvent content is 0.5% by weight.
The following is a more preferable embodiment in which it is not contained at all. The alkaline agent used in the developer according to the present invention is preferably potassium silicate, lithium silicate, sodium silicate,
Sodium hydroxide, potassium hydroxide, lithium hydroxide,
Sodium triphosphate, sodium diphosphate, potassium triphosphate, potassium diphosphate, sodium carbonate,
Examples include potassium carbonate. Among these, a developer containing an alkali silicate such as potassium silicate, lithium silicate, or sodium silicate is most preferable because it has good development gradation.
□) / (M) ~ 0.5 ~ 1.5 (here (SiOz),
(M) indicates the molar concentration of Sing and the molar concentration of total alkali metals, respectively. ), and SiO□ is 0.8~
A developer containing 8% by weight is preferably used. Of this alkali silicate composition, especially in terms of molar ratio (Si(h)
/CM) = 0.5 to 0°75, and S
A developer solution with an iO□ of 0.8 to 4% by weight is preferably used because it is easy to neutralize the developer waste solution due to its low concentration, while a developer solution with a molar ratio of more than 0.75 and up to 1.3, and SiO
A developer containing 1 to 8% by weight of 2 is suitably used because of its high buffering power (and high processing ability).The pH (at 25° C.) of the developer according to the present invention is 12 or higher, preferably 12.
5 to 14. Furthermore, water-soluble sulfites such as sodium sulfite, potassium sulfite, lithium sulfite, and magnesium sulfite can be added to the developer. The preferred content of sulfite in the developer composition is 0.05 to 4% by weight, more preferably 0.1 to 4% by weight.
It is 1% by weight.

In addition, an anionic surfactant and an amphoteric surfactant as described in JP-A-50-51324, and an amphoteric surfactant as described in JP-A-59-75255 and JP-A-59-75255,
By containing at least one of the nonionic surfactants as described in JP-A-55-95946 and JP-A-55-95946,
As described in Japanese Patent No. 142528, the inclusion of a polymer electrolyte can improve the wettability of the photosensitive composition and further improve the gradation, and is therefore preferably used. There is no particular limit to the amount of surfactant added, but
3 to 3% by weight of O,OO is preferred, particularly 6 to 1% of O,OO
Concentrations in weight percent are preferred.

Further, it is preferable that the alkali silicate contains at least 20 mol% of potassium as the alkali metal in all the alkali metals, since the generation of insoluble matter in the developer is small, and more preferably 90 mol% or more of potassium. , most preferably when the potassium content is 100 mol %.

Furthermore, the developer used in the present invention can contain an antifoaming agent. Suitable antifoaming agents include organosilane compounds.

Various conventionally known methods can be used to develop the photosensitive lithographic printing plate according to the present invention which has been imagewise exposed with the developer as described above. Specifically, a method of immersing an image-exposed photosensitive lithographic printing plate according to the present invention in a developer;
A method of ejecting a developer from a number of nozzles onto the photosensitive layer of the photosensitive lithographic printing plate according to the present invention, and wiping the photosensitive layer of the photosensitive lithographic printing plate according to the present invention with a sponge moistened with the developer. method, and a method of applying a developer to the surface of the photosensitive layer of the PS plate using a roller. Further, after applying the developer to the photosensitive layer of the PS plate in this manner, the surface of the photosensitive layer can be lightly rubbed with a brush or the like. The developing conditions can be appropriately selected depending on the developing method. - To give an example, for example, in the development method by immersion, about 1
A method of immersing the film in a developer solution at 0 to 40°C for about 10 to 80 seconds is selected.

〔Example〕

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Production of Aluminum Plate-1 17 g of an aluminum plate with a thickness of 0.24 ax was subjected to electrolytic polishing treatment for 25 seconds at 50 A/dm'' in a ## hydrochloric acid bath at a bath temperature of 25 °C, and the maximum roughness was 4 μm. A grained board was obtained. The grained board was anodized in a 40% by weight phosphoric acid bath at a bath temperature of 35° C. for 20 seconds at 3.2 A/d+*. Next, the anodized aluminum plate was heated at 90°C for 30 minutes in a 1% sodium metasilicate solution.
It was immersed for a second to seal the holes.

Thereafter, it was washed with water and dried to obtain an aluminum plate-1.

Synthesis of diazo compound-1 p-diazodiphenylamine sulfate 14.5 g (50
mmol) was dissolved in 40.9 g of concentrated sulfuric acid under water cooling. To this reaction solution, 1.5 g (50 mmol) of rose formaldehyde was slowly added dropwise. At this time, the reaction temperature is 1
It was added so that the temperature did not exceed 0°C. Thereafter, stirring was continued for 2 hours under water cooling.

This reaction mixture was added dropwise to 500 ml of ethanol under water cooling, and the resulting precipitate was filtered. After washing with ethanol,
Dissolve this precipitate in 100 mf of pure water and add 6.
A cold concentrated aqueous solution of 8 g of zinc chloride was added. The resulting precipitate was filtered, washed with ethanol, and then dissolved in 150
n/! was dissolved in pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate was collected by filtration, washed with water, and then dried at 30°C for one day and night to obtain diazo compound-1.

When the molecular weight of this diazo compound-1 was measured by GPC, it was found that it contained about 50 mol% of pentamers or more.

Synthesis of diazo compound-2 3.5 g (0,025 mol) of p-hydroxybenzoic acid and 22.0 g (0,025 mol) of 4-diazodiphenylamine sulfate
, 025 mol) was dissolved in 90 g of concentrated sulfuric acid under water cooling.

After this reaction, 2.7 g of paraformaldehyde (0,0
9 mol) was added slowly. At this time, the reaction temperature is io
It was added so as not to exceed 'c. Thereafter, stirring was continued for 2 hours under water cooling.

This reaction mixture was cooled with water for 1. Inject into ethanol L7
, the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 200 nl of pure water, and 10.5
A cold concentrated aqueous solution of 1 g of zinc chloride was added. The resulting precipitate was filtered, washed with ethanol, and washed with 300 m
It was dissolved in pure water of j2.

A cold concentrated aqueous solution containing 13.7 g of ammonium hexafluorophosphate was added to this solution. The resulting precipitate was filtered, washed with water, and then dried at 30°C for 51 days to obtain diazo compound-2.

When the molecular weight of this diazo compound-2 was measured by GPC, it was found to be about 2000 in weight average molecular weight.

Synthesis of lipophilic polymer compound-1 N-(4-hydroxyphenyl) methacrylamide 10
．． 0g, acrylonitrile 25g, ethyl acrylate 60g, methacrylic acid 5g and azobisisobutyronitrile 2.0g in acetone-methanol 1:1 mixed solution 1
20mj! After dissolving the mixture in the solution and purging it with nitrogen, it was heated at 60°C for 8 hours.

After the reaction was completed, the reaction solution was poured into 5 drops of water, and the resulting white precipitate was dried to obtain 90 g of polymer compound-1.

When the molecular weight of this lipophilic polymer compound ~1 was measured by GPC, the weight average molecular weight was 63,000.

Examples 1-4. Comparative Examples 1 to 2 After applying a photosensitive liquid having the following composition to the aluminum plate-1 obtained as described above using a whirler,
It was dried at °C for 3 minutes to obtain a photosensitive planographic printing plate.

(Photosensitive liquid composition) Lipophilic polymer compound - 15.0g Diazo compound Listed in Table 1 Jurimer AC-1OL 0.3g (manufactured by Nippon Pure Chemical) Victoria Pure Blue BOH 0.2g (manufactured by Hodogaya Chemical) Development acceleration Agent PP-31 listed in Table-1
21” 0.05g methyl cellosolve 10ml*PP-31 The obtained photosensitive planographic printing plate was heated with a 3kHz ultra-high pressure mercury lamp.
After exposure for 30 seconds from a distance of 0.00 cm, developer-1 shown below was diluted with water to a predetermined magnification and development was performed at 25° C. for 545 seconds.

In addition, for those developed at a dilution rate of 4 times, a printing durability test was conducted using No. 11 ink (Toyo Ultra King Beni) on high-quality paper using a GTO printing machine manufactured by Heidelberg.

The above results are shown in Table-2.

(Developer-1) JIS Sodium Silicate No. 3 2210 g (manufactured by Asahi Denka Kogyo ■) Sodium hydroxide (industrial use) 1150 g Sodium sulfite 67 g Water
2500+++
Table 1 *Examples that exceeded the developability standard - 1 to 4. Comparative Examples 1 and 2 show that the photosensitive lithographic printing plate according to the present invention exhibits excellent developability when developed using the developer according to the present invention, and a lithographic printing plate with excellent stiffness resistance can be obtained. I understand.

(Effects of the Invention) As explained in detail above, the method for producing a lithographic printing plate of the present invention provides a lithographic printing plate with excellent developability and stiffness resistance without using a developer containing an organic solvent. It is effective.

Applicant: Mitsubishi Kasei Co., Ltd., 1 agent, Patent attorney Hase, and 1 other person Procedural amendment (spontaneous) Date of August 2, 1999 No. 10739 Name of the invention Person who corrects the manufacturing method of printing plates 2-5-2-5 Marunouchi, Chiyoda-ku, Tokyo! Column 6 of “Detailed Description of the Invention” of the specification subject to fi-correct Contents of M-correct

Claims (1)

[Claims] A photosensitive lithographic printing plate having a photosensitive layer containing a diazo compound, a lipophilic polymer compound, and a development accelerator on a support,
1. A method for producing a lithographic printing plate, which comprises developing the lithographic printing plate with an alkaline aqueous solution having a pH of 12 or higher and substantially free of organic solvents after image exposure.