JPH0266A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To enhance developability and to prevent remaining of a diazonium compound by incorporating a condensed copolymer comprising an aromatic compound having at least one carboxylic group and at least one hydroxyl group and an aromatic diazonium compound as structural units. CONSTITUTION:The aromatic compound having a carboxylic group and a hydroxyl group A, such as salicylic acid or p-hydroxybenzoic acid, and the aromatic diazo compound B, such as 4-diazophenylamine sulfate or tetrafluoroborate, in an A/B molar ratio of 1/1-0.2/1 and one of aldehydes and ketones C in a (A+B)/C molar ratio of 1/0.7-1/1.5 are mixed and reacted for 3 hours to obtain the condensation copolymer resin, such as a diazophenylamine salicylate resin, having a molecular weight of 800-5,000 by controlling a feed proportion and condensation conditions, and further, an alkali soluble or swellable oleophilic polymer, such as polyacrylamide having aromatic hydroxyl groups, is combined with said resin as a binder, and this composition is soluble in alkali, and the binder can be selected from a wide range of resins.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photosensitive composition, and particularly to a photosensitive composition suitable for manufacturing a photosensitive lithographic printing plate.

[Background of the invention]

Photosensitive printing plates are generally produced by coating a photosensitive composition on a support such as an aluminum plate, irradiating it with active light such as ultraviolet rays through a negative image, polymerizing or crosslinking the irradiated areas, and turning the composition into a developer. Insolubilize and elute non-light irradiated areas into a developer, making each area an image area that repels water and receives oil-based ink, and a non-image area that receives water and receives oil-based ink. It is obtained by

As photosensitive compositions in this case, diazo resins such as condensates of P-diazodiphenylamine and formaldehyde have been widely used.

However, conventionally known diazo resins generally do not have alkali solubility, so when developing a photosensitive composition containing it with an alkaline developer after exposure, it is difficult to develop the diazo resin, especially under under conditions. There is a problem in that the developability at the bottom is not good, and a so-called diazo residue, in which the diazo resin remains in the form of a film on the surface of the support after development, is caused, resulting in a decrease in printability.

Therefore, the main object of the present invention is to provide a lipophilic polymer compound (
The object of the present invention is to provide a novel photosensitive composition that can expand the selection range of binder resins.

[Means for solving problems]

The above object is achieved by containing a co-condensed compound containing an aromatic compound having at least one carboxyl group and at least one hydroxyl group and an aromatic diazonium compound as a constituent unit.

Specific configuration of invention C] The present invention will be explained in more detail below.

The aromatic compound having a carboxyl group and a hydroxyl group according to the present invention contains an aromatic ring substituted with at least one carboxyl group and an aromatic ring substituted with at least one hydroxyl group in the molecule. 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 present invention, 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.

In order to condense the above-mentioned aromatic compounds with aldehydes or ketones, at least two unsubstituted sites on the aromatic ring of one or more aryl groups substituted with at least one hydroxyl group are required. It is necessary to have

Specific examples of aromatic compounds having a carboxyl group and a hydroxyl group in the molecule used in the present invention include salicylic acid, 4-methylsalicylic acid, 6-methylsalicylic acid, 4-ethylsalicylic acid, 6-propyl salicylic acid, 6-propyl salicylic acid,
-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-methylbenzoic acid, 4-chloro-2,6-dihydroxybenzoic acid,
4-methoxy-2,6-dioxybenzoic acid, gallic acid,
Phloroglucin carboxylic acid, 2.4.5-) dihydroxybenzoic acid, m-galloyl gallic acid, tannic acid, m
-benzoyl gallic acid, m-(p-toluyl) gallic acid, protocatechoyl gallic acid, 4,6-cyhydroxyphthalic acid, (2,4-dihydroxyphenyl) acetic 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-(.

-hydroxybenzoyl)benzoic acid, 4-(2,4dihydroxybenzoyl)benzoic acid, 4-(p-hydroxyphenoxy)benzoic acid, 4-(p-hydroxyanilino)benzoic acid, bis(3-hydroxybenzoyl)benzoic acid, -hydroxyphenyl)amine, 4(p-hydroxyphenylsulfonyl)benzoic acid, 4-(p-hydroxyphenylthio)
Examples include benzoic acid, and among these, particularly preferred are:
These are salicylic acid, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, gallic acid, phloroglucincarboxylic acid, and 4-(p-hydroxyanilino)benzoic acid.

The aromatic diazo compound used in the present invention is not particularly limited as long as it has a diazonium group directly bonded to the aromatic ring, but examples thereof include 4-diazophenylamine sulfate, 4-diazophenylamine sulfate, -Diazodiphenylamine tetrafluoroborate, 4-diazodiphenylamine hexafluoride phosphate, 4-morpholino-benzenediazonium tetrafluoroborate, 4-(N-ethyl-N-hydroxyethyl)-aminobenzenediazonium Sulfate, 4-N
, N'-dimethylaminobenzenediazonium hexafluorophosphate, and 8-hydroxy-2naphthalenediazonium tetrafluoroborate. Among these, particularly preferred aromatic diazo compounds include 4-diazodiphenylamine salts.

The photosensitive diazo cocondensation resin according to the present invention can be prepared by a known method,
For example, Photographic Science and Engineering Link (Photo, Sci.

Eng., Volume 17, Page 33 (1973), U.S. Patent No. 2.063,631, U.S. Patent No. 2.679.498. It is obtained by polycondensation of salts, aromatic compounds having carboxyl and hydroxyl groups, and aldehydes, such as paraformaldehyde, acetaldehyde, benzaldehyde, or ketones, such as acetone and acetophenone.

In addition, these aromatic compounds, aromatic diazo compounds, and aldehydes or ketones having carboxyl groups and hydroxyl groups in their molecules can be freely combined with each other, and it is also possible to co-condense two or more of each. be. Furthermore, co-condensation can be carried out by adding a co-condensable phenol having no carboxyl group.

At that time, the charging molar ratio of the aromatic compound having a carboxyl group and a hydroxyl group and the aromatic diazo compound is
1:0.1-0.1:1; preferably 1:0.5-0.
The ratio is 2:1, more preferably 1:1 to 0.2:1. In this case, the total of the compound having a carboxyl group and a hydroxyl group and the aromatic diazo compound and the aldehyde or ketone are usually mixed in a molar ratio of t:O,S to 1:2.
, preferably at a ratio of 1:0.7 to 1:1.5, and reacted at low temperature for a short time, for example, about 3 hours, to obtain a diazo cocondensation resin.

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

These include organic carboxylic acids such as decanoic acid and benzoic acid; acids, 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, Hydroxyl group-containing aromatic compounds such as 1,2,3-trihydroxybenzophenone and 2,2',4-trihydroxybenzophenone, halogenated Lewis acids such as hexafluorophosphoric acid and tetrafluoroboric acid, and peroxidases such as CI204.104. Examples include, but are not limited to, halogen acids. Among these, particularly preferred are hexafluorophosphoric acid and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid.

Examples of condensation type resins (hereinafter referred to as diazo cocondensation resins) with aldehydes or ketones containing aromatic compounds having carboxyl groups and hydroxyl groups and aromatic diazo compounds as structural units used in the present invention include: , 4-diazodiphenylamine salicylate/hexafluorophosphate-formaldehyde resin, 4-diazodiphenylamine 4-methylsalicylate/tetrafluoroborate formaldehyde resin, p-hydroxybenzoic acid-4-diazodiphenylamine/hexafluoride Phosphate-formaldehyde resin, 2,4-dihydroxybenzoic acid-4-diazodiphenylamine/2-hydroxy-4-methoxybenzophenone-5-sulfonate-formaldehyde resin, gallic acid 4-diazodiphenylamine/hexafluorophosphate -Formaldehyde resin, phloroglucincarboxylic acid -4-diazodiphenylamine/tetrafluoroborate-
Acetaldehyde resin, (2,4-dihydroxyphenyl)acetic acid-4-(N-ethyl-N-hydroxyethyl)
-Aminobenzenediazonium/hexafluorophosphate -benzaldehyde resin, 4-(0-hydroxybenzoyl)benzoic acid-4-diazodiphenylamine/hexafluorophosphate -formaldehyde resin, 4-(p-hydroxyphenoxy)benzoic acid Acid-4-diazodiphenylamine/hexafluorophosphate-formaldehyde resin, 4-(
p-hydroxyanilino)benzoic acid-4-diazodiphenylamine/hexafluorosulfate-formaldehyde tree M
L 4 (p-hydroxyphenylsulfonyl)benzoic acid-4-diazodiphenylamine/hexafluorophosphate-formaldehyde resin, etc.; particularly preferred among these are salicylic acid-4-diazodiphenylamine/hexafluorophosphate- Formaldehyde resin, p-hydroxybenzoic acid-4-diazodiphenylamine/hexafluorophosphate-formaldehyde resin, 2,4-dihydroxybenzoic acid-4-diazodiphenylamine/2-hydroxy-4-methoxybenzophenone-5-sulfonic acid Salt-
Formaldehyde resin and 4-(p-hydroxyanilino)benzoic acid-4-diazodiphenylamine/hexafluorosulfate-formalde resin. The diazo cocondensation resin of the present invention can have any molecular weight by varying the molar ratio of each monomer and the condensation conditions, but it can be effectively used for the purpose of the present invention. The molecular weight is about 400 to 10,000.
can be used, but preferably about 800 to 5
,000 is appropriate.

The photosensitive diazo cocondensation resin described above is desirably used in combination with an alkali-soluble or swellable lipophilic polymer compound as a binder resin.

Examples of this lipophilic polymer compound include copolymers having a molecular weight of usually 20,000 to 200,000 and having monomers shown in (1) to Oz below as structural units.

(1) Acrylamides, methacrylamides, acrylic esters, and methacrylic esters having an aromatic hydroxyl group, such as N-(4-hydroxyphenyl)
Acrylamide or N-(4-hydroxyphenyl)methacrylamide, 〇-m-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. 2-chloroethyl, glycidyl acrylate, N-
(Substituted) alkyl acrylates such as dimethylaminoethyl acrylate, (5) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate, etc. (Substituted) alkyl methacrylate, (6) acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-
Acrylamides or methacrylamides such as hydroxyethyl acrylamide, N-phenylacrylamide, N-nitrophenyl acrylamide, N-ethyl-N-phenylacrylamide, (7) ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, Vinyl ethers such as butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, etc. (8) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate, etc. (9) Styrene, α-methylstyrene, methylstyrene, chloro Styrenes such as methylstyrene, α [vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone, αυ olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene, 0EN-vinylpyrrolidone, N -vinylcarbazole, 4-vinylpyrine, acrylonitrile, methacrylatetrile, etc. Furthermore, a heptamer which can be copolymerized with the above monomers may be copolymerized. It also includes, but is not limited to, copolymers obtained by copolymerizing the above monomers and modified with glycidyl methacrylate, glycidyl acrylate, and the like.

More specifically, the above +1). A copolymer having a hydroxyl group containing a monomer etc. listed in T2) is preferable,
More preferred are copolymers having aromatic hydroxyl groups.

The copolymer preferably contains an α,β-unsaturated carboxylic acid listed in (3), and the copolymer preferably has an acid value of 10 to 100.

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

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

A particularly preferable lipophilic polymer compound as a binder is the following copolymer having methyl acrylate as a structural unit.

That is, in the molecular structure, (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) the following - maximum ■, CI2-C-...I N (wherein R1 is a hydrogen atom or an alkyl group) 5 to 40 mol% of structural units represented by ), fc) 5 to 40 mol% of units formed from methyl acrylate, (dl below - maximum ■, cut-c-...・■ GOOR' (In the formula, R2 represents a hydrogen atom, a methyl group, or an ethyl group, and R3 represents an alkyl group or an alkyl-substituted aryl group having 2 to 12 carbon atoms.) 60 mol%, and (e) 2 to 30 mol% of a structural unit having a carboxyl group, and has a weight average molecular weight of 50,000 to 200,000.

Specific examples of the hexamer forming the structural unit having an alcoholic hydroxyl group include (meth)acrylic acid esters such as the compounds shown in the maximum (I[) below as described in Japanese Patent Publication No. 527364. and acrylamides.

S 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 of IQ.

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-( Monomers of (meth)acrylamides such as 4-hydroxynaphthyl (meth)acrylamide: o-, m- or p-hydroxyphenyl (meth)acrylate monomers: O-
Examples include m- or p-hydroxystyrene monomers. Preferably, the o-, m- 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 preferably selected from a range of 1 to 50 mol%, preferably 5 to 30 mol%, in the polymer compound.

Examples of the seven polymers having a cyano group in the side chain and forming the structural unit represented by the maximum I include acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, and 2-cyanoethyl acrylate. , 〇-1m-1p-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 desirably 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.

The monomers having a carboxy ester group in the side chain and forming the structural unit represented by -maximum (■) include ethyl acrylate, ethyl methacrylate, propyl acrylate, butyl acrylate, amyl acrylate,
amyl methacrylate, hexyl acrylate, octyl acrylate, 2-chloroethyl acrylate, 2-
Examples include hydroxyacrylate, glycidyl acrylate, and the like. The units formed from the monomer account for 25 to 60 mol%, preferably 35 to 6 mol%, in the polymer compound.
It is selected from the range of 0 mol%.

Furthermore, examples of monomers forming structural units having carboxyl groups include methacrylic acid, acrylic acid, maleic anhydride, maleic acid, and the like. The monomer accounts for 2 to 30 mol%, preferably 5 to 15 mol% in the polymer compound.
Selected from the range of mol%.

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

As a method for synthesizing the lipophilic polymer compound as a binder in the composition of the present invention, a generally known radical polymerization method or the like may be used, for example, using an initiator (0,1- 4.0 mol%) by a solution polymerization method.

The lipophilic polymer compound used in the present invention is usually 40 to 99% by weight, preferably 50 to 99% by weight in the solid content of the photosensitive composition.
Contains 95% by weight. Further, the photosensitive diazo resin used in the present invention is usually 1 to 60% by weight, preferably 3 to 3% by weight.
Contains 0% by weight.

A dye can further be used in the photosensitive composition of 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 BOH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.), Patent Pure Blue (manufactured by Juju Kingdom Chemical Co., Ltd.), Crystal Violet, Brilliant Green, Ethyl Bioleft, Methyl Violet, Triphenylmethane type, represented by methyl green, erythrosin B1 basic tsuksin, malachite green, oil red, m-cresol purple, rhodamine B1 auramine, 4-p-diethylaminophenylimino naphthoquinone, 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, triphenylamine, diphenylamine, 0-chloroaniline, 1.2.3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p'-bis -dimethylaminodiphenylamine,
1.2-dianilinoethylene, p,p +p-tris-dimethylaminotriphenylmethane, plp
-bis-dimethylaminodiphenylmethylimine, p,
p', p"-triamino-0-methyltriphenylmethane, p, p"-bis-dimethylaminodiphenyl-4-
Examples include primary or secondary arylamine dyes typified by anilinonaphthylmethane and p,p,p''-triaminotriphenylmethane.

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

The above-mentioned dye is usually contained preferably in an amount of about 0.5 to about 10% by weight, more preferably in an amount of about 1 to 5% by weight in the photosensitive composition.

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

For example, alkyl ethers (
(e.g., ethyl cellulose, methyl cellulose), fluorine-based surfactants, nonionic surfactants (e.g., Pluronic L-64 (manufactured by Asahi Denka Corporation)), plasticizers for imparting flexibility and abrasion resistance to coating films. agents (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), fat-sensitizing agents for improving the fat-sensitivity of image areas (for example, JP-A-55-527) half-esterified styrene-maleic anhydride copolymer with alcohol, etc.), stabilizers [e.g., phosphoric acid, phosphorous acid, organic M (citric acid, oxalic acid, benzenesulfonic acid, naphthalenesulfonic acid, 4- methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric 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.

Such a photosensitive composition is coated on a support. As this support, aluminum or its alloy plate,
Examples include metal plates such as zinc plates, copper plates, and stainless steel plates, and plastic films such as polyethylene terephthalate and polypropylene.

When the photosensitive composition of the present invention is applied to the production of a photosensitive lithographic printing plate, it is used by being provided on a support such as an aluminum or alloy plate thereof.

The support used in the photosensitive lithographic printing plate is as follows:
Paper, plastics (e.g. polyethylene, polypropylene, polystyrene, etc.) laminated paper, plates of metals such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose diacetate, cellulose triacetate, cellulose propionate, polyethylene terephthalate, Plastic films such as polyethylene, polypropylene, polycarbonate polyvinyl acetal, etc., paper or plastic films laminated or vapor-deposited with metals such as those mentioned above, steel plates plated with aluminum or chrome, etc. and aluminum-coated composite supports are preferred.

Further, the surface of the aluminum material is preferably roughened for the purpose of increasing water retention and improving adhesion with the photosensitive layer.

Examples of the surface roughening method include generally known methods such as brush polishing, ball polishing, electrolytic etching, chemical etching, liquid honing, sandblasting, etc., and combinations thereof, and preferably brush polishing, electrolytic etching, and chemical etching. Mention may be made of target etching and liquid honing, among which roughening methods involving the use of electrolytic etching are particularly preferred. The electrolytic bath used in electrolytic etching is an aqueous solution containing an acid, an alkali, or a salt thereof, or an aqueous solution containing an organic solvent. Liquid is preferred. Further, the roughened aluminum plate is desmutted with an acid or alkali aqueous solution, if necessary. It is desirable that the aluminum plate thus obtained is subjected to anodizing treatment, and particularly preferred is a method of treatment in a bath containing sulfuric acid or phosphoric acid. Further, if necessary, a sealing treatment using an alkali silicate or hot water, and a surface treatment such as immersion in a water-soluble polymer compound or an aqueous potassium fluorozirconate solution can be performed.

To provide the above photosensitive composition on a support, predetermined amounts of a photosensitive diazo cocondensation resin, a lipophilic polymer compound, and, if necessary, various additives are added to a suitable solvent (methyl cellosolve, ethyl cellosolve). , methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethyl formamide, dimethyl sulfoxide, water, or a mixture thereof, etc.) to prepare a coating solution of the photosensitive composition, and apply this onto a support and dry it. good. 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
In general, it may be about 0.2 to 10 g/rrf.

Conventional methods are applied to the photosensitive material coated on the support. That is, by exposing a transparent original image having a line image, a halftone image, etc. to light, and then developing it with an aqueous developer, a negative relief image can be obtained with respect to the original image. Examples of active light sources suitable for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, and the like.

The developer used for developing the photosensitive composition according to the present invention contains a specific organic solvent, an alkaline agent, and water as essential components. The specific organic solvent herein refers to the non-exposed area (
An organic solvent that can dissolve or swell the non-image area) and has a solubility in water of 10% by weight or less at room temperature (20°C). 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, and acetic acid. Carboxylic acid esters such as butyl, amine acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, butyl levulinate; ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone; ethylene glycol monobutyl ether, ethylene glycol benzyl Alcohols such as ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; methylene dichloride, ethylene dichloride, monochlorobenzene. There are halogenated hydrocarbons such as One or more of these organic solvents may be used. Among these organic solvents, ethylene glycol monophenyl ether and benzyl alcohol are particularly effective. The content of these organic solvents in the developer is generally 1 to 20% by weight, particularly 2 to 1% by weight.
More preferable results are obtained when the amount is 0% by weight.

On the other hand, the alkaline agents contained as essential components in the developer include (A) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium dibasic or tertiary phosphate, or Inorganic alkaline agents such as ammonium salts, sodium metasilicate, sodium carbonate, ammonia, etc. (B) Mono-, di- or trimethylamine, mono-, di- or triethylamine, mono- or diisopropylamine, n-
Examples include organic amine compounds such as butylamine, mono-, di-, or triethanolamine, mono-, di-, or triisopropanolamine, ethyleneimine, and ethylenediamine.

The content of these alkaline agents in the developer is usually 0.
0.5 to 4% by weight, 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-soluble 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 0.05 to 4% by weight, preferably 0.1 to 1% by weight.

If such a developer is brought into contact with the photosensitive composition after imagewise exposure or is rubbed with the developer, the exposed areas of the photosensitive composition layer will be removed after 10 to 60 seconds at room temperature to 4oC. The photosensitive composition in non-exposed areas is completely removed without adversely affecting the surface of the photosensitive lithographic printing plate, for example, resulting in a photosensitive lithographic printing plate.

Next, a typical synthesis example of the diazo cocondensation resin according to the present invention will be shown.

Next, a typical synthesis example of the diazo cocondensation resin according to the present invention will be shown.

(Synthesis Example 1) 3.5 g (0,025 mol) of p-hydroxybenzoic acid and 22.0 g of 4-diazodiphenylamine sulfate
g (0,025 mol) was dissolved in 90 g of concentrated sulfuric acid under water cooling. After this reaction, 2.7 g of paraformaldehyde (
0.09 mol) was added slowly. 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 poured into the ethanol of 1) under water cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was washed with 200 m
j2 of pure water, and to this solution was added a cold concentrated aqueous solution in which 10.5 g of zinc chloride was dissolved. The resulting precipitate was filtered, washed with ethanol, and dissolved in 300 mj2 of pure water. 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 one day and night to obtain diazo cocondensation resin-1.

The molecular weight of this diazo cocondensation resin-1 was measured by gel permeation chromatography (hereinafter abbreviated as GPC), and the weight average molecular weight was about 2,000.

Regarding the other diazo cocondensation resins mentioned above, Synthesis Example 1
It can be synthesized by the same method as .

Next, a synthesis example of the lipophilic polymer compound according to the present invention will be shown.

(Synthesis of lipophilic polymer compound 1) N-(4-hydroxyphenyl) methacrylamide 10
．． 0g, acrylonitrile 25g1 ethyl acrylate 60g, methacrylic acid 5g and azobisisobutyronitrile 1,642g in acetone-methanol 1:1 mixed solution 1) 2mj! After dissolving the mixture in a nitrogen atmosphere, the mixture was heated at 60° C. for 8 hours.

After the reaction is completed, the reaction solution is stirred and poured into water 51, and the resulting white precipitate is filtered and dried to obtain 90 g of lipophilic polymer compound 1.
Obtained.

When the molecular weight of this lipophilic polymer compound 1 was measured by GPC, the weight average molecular weight was 85,000.

(Synthesis of lipophilic polymer 2) 50.0 g of 2-hydroxyethyl methacrylate.

Acrylonitrile 20g, methyl methacrylate 25g
A mixture of 5 g of methacrylic acid and 1.2 g of benzoyl peroxide was added dropwise over 2 hours to 300 g of ethylene glycol monomethyl ether heated to 100°C. After the dropwise addition was completed, 300 g of ethylene glycol monomethyl ether and 0.3 g of benzoyl peroxide were added, and the mixture was allowed to react for 4 hours. After the reaction was completed, the mixture was diluted with methanol and poured into water 51 with stirring, and the resulting white precipitate was collected by filtration and dried to obtain 90 g of lipophilic polymer compound 2.

When the molecular weight of this lipophilic polymer compound was measured by GPC, the weight average molecular weight was 65,000.

(Synthesis of lipophilic polymer compound 3) A mixed solution of 45 g of 2-hydroxyethyl methacrylate, 10 g of acrylonitrile, 35 g of ethyl methacrylate, 10 g of methacrylic acid, and 1.2 g of benzoyl peroxide was added to ethylene in the same manner as in the synthesis of lipophilic polymer compound 2. The mixture was added dropwise to glycol monomethyl ether to obtain 90 g of lipophilic polymer 3.

When the molecular weight of this lipophilic polymer compound was measured by GPC, the weight average molecular weight was 62,000.

(Synthesis of lipophilic polymer compound 4) Under a nitrogen stream, 100 g of acetone and 100 g of methanol
To a mixed solvent of 25 g of N-(4-hydroxyphenyl) methacoolamide, 4.0 g of acrylonitrile, 18 g of methyl acrylate, 60 g of ethyl acrylate, 10 g of methacrylic acid, and 3.0 g of azobisisobutyronitrile.
5g was dissolved, and the mixture was heated at 60℃ for 8 hours while stirring.
heated for an hour. After completion of the reaction, the reaction solution was poured into water, the white precipitate formed was filtered and dried, and the lipophilic polymer compound 4 was dissolved into 1
) 0g obtained. The weight average molecular weight of this vacuum-dried copolymer was 10,000.

〔Example〕

(Example 1) An aluminum plate was degreased with a 3% aqueous sodium hydroxide solution, electrolytically etched in a 2% hydrochloric acid bath at a current density of 13 A/dm2 at 25°C, and after washing with water, etched in a 30% sulfuric acid bath for 30 minutes.
Anodic oxidation treatment was performed for 2 minutes at 0°C and 1.5 A/dm2. Next, 1% sodium metasilicate aqueous solution at 85°C,
The pores were sealed for 30 seconds, washed with water, and dried to obtain an aluminum plate for planographic printing. A photosensitive liquid having the following composition was applied to this aluminum plate so that the film weight after drying was 1.5 g/m''.

Photosensitive liquid-1 Lipophilic polymer compound-15.0g Diazo cocondensation resin-1 (Synthesis example 1) 0.5g Methyl cellosolve 100ml 1l The obtained photosensitive lithographic printing plate was brought into close contact with a negative transparent original image, and 2KW metal halide was applied. The film was exposed to light from a distance of 60 cm using a lamp for 30 seconds, and developed at 25° C. for 40 seconds using developer-1 having the following composition.

Composition of developer-1 Benzyl alcohol 50g Triethanolamine 15g Sodium sulfite 5g Sodium butylnaphthalene sulfonate 25g Water
1000gNext, prepare a diluted developer (Developer-2) in which an equal volume of pure water was added to Developer-1 and a diluted developer (Developer-3) in which twice the amount of pure water was added, and the above When development was carried out in the same manner as above, in both cases, a good printing plate was obtained with no developing defects (stains) in the non-image areas.Next, to examine the diazo residue in the non-image areas, When half of the non-image area of the thus obtained printing plate was exposed again and compared with the area that was not re-exposed, it could not be visually distinguished.Also, the above-mentioned photosensitive lithographic printing plate was subjected to forced storage (55℃, When the plate making was carried out in the same manner as described above, good printing plates were obtained without staining in any of the developing solutions.

When the printing plate obtained as described above was printed on an offset printing machine, a large number of prints with sharp and high contrast images were obtained.

(Comparative Example-1) The same procedure as in Example 1 was carried out except that the diazo cocondensation resin-1 in the photosensitive liquid-1 in Example 1 was replaced with the following diazo resin-1. Diazo resin-1 was prepared in the same manner as in Synthesis Example 1, except that p-hydroxybenzoic acid was omitted and 29.3 g (0.1 mol) of 4-diazodiphenylamine sulfate was used as the raw material. Obtained. The obtained 4-diazodiphenylamine hexafluorophosphate
The molecular weight of the formaldehyde resin was measured by GPC, and the weight average molecular weight was approximately 2,300.

As a result, when developed using developer-3, stains occurred in the non-image areas of the printing plate. In addition, with respect to the photosensitive lithographic printing plates that were forcibly stored, stains occurred in the non-image areas in the case of Developer Solution-2 and Developer Solution-3.

On the other hand, regarding the diazo residue in the non-image area, when half of the non-image area of the printing plate that was well developed using developer-1 was re-exposed and compared with the area that was not re-exposed, it was visually observed. Diazo residue was clearly observed in areas that were not re-exposed.

(Example 2) A photosensitive liquid having the following composition was coated on the same aluminum plate as in Example 1 so that the layer weight after drying was 1.7 g/m2.

Photosensitive liquid-2 Lipophilic polymer compound-25.0g 2.4-dihydroxybenzoic acid-4-diazophenylamine/2-hydroxy-4-methoxybenzophenone-
5-sulfonate-formaldehyde resin (synthesized in the same manner as Synthesis Example 1, weight average molecular weight 2,500)
0.7 g (manufactured by Nippon Junraku) 0.3 g Methyl cellosolve 100 ml The obtained photosensitive lithographic printing plate was exposed for 40 seconds under the same conditions as in Example 1, and the same developer used in Example 1 was used. -1 to 3, development was performed at 30°C for 20 seconds, and in all cases, good printing plates with no stains in non-image areas were obtained. Next, when the diazo residue in the non-image area was examined in the same manner as in Example 1, it could not be visually observed. Furthermore, when the photosensitive lithographic printing plates that had been forcibly stored were developed, no stains were observed and the printing results were good.

(Example 3) After forming primary grains on a degreased aluminum plate by a liquid honing method using 400 mesh of bumstone-water suspension, the surface was lightly etched with 10% sodium hydroxide, and % nitric acid bath at 30 °C, IO
Secondary grains were formed by electrolytic etching at a current density of A/dm2. Next, anodizing treatment and sealing treatment were performed in the same manner as in Example 1 to obtain an aluminum plate for a lithographic printing plate.

A photosensitive liquid having the following composition was applied to this aluminum plate so that the layer weight after drying was 1.5 g/m<2>.

Photosensitive liquid-3 Lipophilic polymer compound-35.0g 4-(p-hydroxyanilino)benzoic acid-4diazodiphenylamine/hexafluorophosphate-formaldehyde resin (weight average molecular weight 2,700) 0. 7
g Methyl cellosolve 100mf The obtained photosensitive lithographic printing plate was processed under the same conditions as in Example 1 for 40
Exposure for seconds and the same developer solution-1 to 3 used in Example 1.
When development was carried out at 30° C. for 20 seconds, good printing plates with no stains in non-image areas were obtained in all cases. Next, when the diazo residue in the non-image area was examined in the same manner as in Example 1, it could not be visually observed. Furthermore, when the photosensitive lithographic printing plates that had been forcibly stored were developed, no stains were observed and the printing results were good.

(Example 4) A photosensitive liquid having the following composition was coated on the same aluminum plate as in Example 1 so that the layer weight after drying was 1.6 g/nf.

Photosensitive liquid-4 Lipophilic polymer compound-45.0g Diazo cocondensation resin-1 (Synthesis example 1) 0.7g Oil Blue #603 (Orient chemical side type) 0.2g Jurimer MCl0L (manufactured by Nippon Pure Chemical Industries Ltd.) > 0 .3g Methyl cellosolve 100mj!The obtained photosensitive lithographic printing plate was exposed for 40 seconds under the same conditions as in Example 1, and then exposed to light for 20 seconds at 30°C using the same developer 1 to 3 used in Example 1. When development was carried out, a good printing plate with no stains in the non-image area was obtained in all cases.Next, the diazo residue in the non-image area was examined in the same manner as in Example 1, and it was visually observed. Furthermore, when the photosensitive lithographic printing plate that had been forcibly stored was developed, no stains were observed and the printing results were good.

〔Effect of the invention〕

As described above, according to the present invention, the developability is excellent and diazo residue can be prevented.

Claims (1)

[Claims] (1) at least one carboxyl group and at least one
1. A photosensitive composition comprising a co-condensation compound containing an aromatic compound having two hydroxyl groups and an aromatic diazonium compound as constituent units.