JP2671406B2 - Photosensitive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photosensitive composition, and particularly to a photosensitive lithographic printing plate.

[Background of the Invention]

In general, a photosensitive printing plate is prepared by coating a photosensitive composition on a support such as an aluminum plate, and irradiating active light such as ultraviolet light through a negative image or the like, and polymerizing or crosslinking the irradiated portion to form a developer. Insolubilize and elute the non-irradiated part of the light into the developer, and make each part an image part that repels water and receives oil-based ink and a non-image part that receives water and receives oil-based ink Is obtained by

As the photosensitive composition in this case, a diazo resin such as a condensate of p-diazodiphenylamine and formaldehyde has been widely used.

However, since conventionally known diazo resins have low photosensitivity and generally do not have alkali solubility, a photosensitive composition containing the diazo resin is exposed to light and then developed with an alkali developing solution. Properties, particularly developability under under conditions, is not good, and there is also a problem that a so-called diazo residue that a diazo resin remains in a film form on the surface of a support after development causes deterioration of printability.

Further, in a lithographic printing plate, an image is generally formed by a photoengraving method, but in this case, the image is reproduced on the printing plate so as to be thicker than the image line of the film original (hereinafter, abbreviated as "dot thickening"). . As a result, in the final printed matter, the halftone dots of the shadow are crushed, and a printed matter that is far apart from the original is produced, which is inconvenient in many cases.

Therefore, a main object of the present invention is to provide a novel photosensitive composition having high sensitivity, excellent developability, and small dot weight.

(Means for Solving the Problems) The above-mentioned object is, in a photosensitive composition containing a photosensitive diazo resin, (A) an aromatic water compound substantially having at least one carboxylic acid group as an diazo resin and an alkoxy group. (B) (i) Unsaturated compound having an aromatic hydroxyl group and / or unsaturated compound having an aliphatic hydroxyl group, containing only a co-condensed diazo resin obtained by co-condensing an aromatic diazo compound having no Compound and (ii)
This is achieved by containing a copolymer containing α, β-unsaturated carboxylic acid as a structural unit.

(Specific Structure of the Invention) Hereinafter, the present invention will be described in more detail.

The aromatic compound having at least one carboxylic acid group according to the present invention includes an aromatic ring substituted with at least one carboxylic acid group, for example, a benzene ring, a naphthalene ring or the like in the molecule, In this case, the carboxylic acid group may be directly bonded to the aromatic ring or may be bonded via a linking group. Examples of the linking group include an alkylene group having 1 to 4 carbon atoms.

Further, the above aromatic ring may be substituted with a substituent other than the carboxylic acid group. Examples thereof include an alkyl group having 1 to 4 carbon atoms, an alkoxy group, a cyano group, and a halogen atom.

In the present invention, the number of carboxylic acid groups bonded to the aromatic ring is preferably 1 or 2.

The aromatic compound may have at least two unsubstituted moieties on the aromatic ring of one or more aryl groups substituted with at least one carboxylic acid group in order to condense with aldehydes or ketones. is necessary.

Specific examples of the aromatic compound having a carboxylic acid group in the molecule used in the present invention include p-methoxybenzoic acid,
p-ethoxybenzoic acid, o-, m-, p-methylbenzoic acid, o-, m-, p-cyanobenzoic acid, 3,4-dimethoxybenzoic acid, 2,4-dimethoxybenzoic acid, 2,4- Dimethylbenzoic acid, 4-dimethylaminobenzoic acid, 4-anilinobenzoic acid, phenoxyacetic acid, 4-methoxyphenylacetic acid, p-phenoxybenzoic acid, N-phenylglycine,
Isophthalic acid, terephthalic acid, DL-mandelic acid, acetylsalicylic acid, cinnamic acid, 1-naphthalenecarboxylic acid, 2
-Naphthalenecarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and the like can be mentioned. Of these, p-methoxybenzoic acid, p-ethoxybenzoic acid, o-, m-, p-methylbenzoic acid, o-, m-, p-chlorobenzoic acid, 2,4-dimethoxybenzoic acid, 4-dimethylaminobenzoic acid, 4-anilinobenzoic acid, p-phenoxybenzoic acid, N- Phenylanthranilic acid, terephthalic acid, cinnamic acid, 1-naphthalenecarboxylic acid and the like.

The aromatic diazo compound having no alkoxy group used in the present invention is not particularly limited as long as it is a compound in which a diazonium group is directly bonded to an aromatic ring.
Examples thereof include 4-diazophenylamine sulfate and 4
-Diazodiphenylamine tetrafluoroborate, 4-diazodiphenylamine hexafluorophosphate, 4-morpholino-benzenediazonium tetrafluoroborate, 4- (N
-Ethyl-N-hydroxyethyl) -aminobenzenediazonium sulfate, 4-N, N'-dimethylaminobenzenediazonium hexafluorophosphate, and 8-hydroxy-2-naphthalenediazonium tetrafluoroborate. To be Among them, a particularly preferred aromatic diazo compound having no alkoxy group is 4-diazophenylamine salt.

The photosensitive diazo co-condensation resin according to the present invention can be produced by a known method, for example, Photographic Science and Engineering (Photo, Sci., Eng.) Vol. 17, No. 33.
(1973), U.S. Pat. Nos. 2,063,631 and 2,679,498, the aromatic compounds and aldehydes having an azonium salt and a carboxylic acid group, such as laformaldehyde, in sulfuric acid, phosphoric acid or hydrochloric acid, according to the method described in each specification. , Acetaldehyde, benzaldehyde or ketones such as acetone or acetophenone.

The aromatic compound having a carboxylic acid group in the molecule, the aromatic diazo compound, and the aldehydes or ketones can be freely combined with each other, and two or more kinds of them can be mixed and co-condensed. At that time, the charged molar ratio of the aromatic compound having a carboxylic acid group and 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 0.2: 1. Further, in this case, the total of the compound having a carboxylic acid group and the aromatic diazo compound and the total of the aldehyde and the aromatic diazo compound and the aldehyde or the keto is usually 1: 0.6 to 1:
2, preferably 1: 0.7 to 1: 1.5, low temperature, short time,
For example, a diazo resin can be obtained by reacting for about 3 hours.

The counter anion of the diazo resin used in the present invention includes an anion which forms a stable 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 and sulfonic acids such as phenylphosphoric acid, and typical examples include methanesulfonic acid, chloroethanesulfonic acid,
Dodecane sulfonic acid, benzene sulfonic acid, toluene sulfonic acid, mesitylene sulfonic acid, and antonlaquinone sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2,2 ', 4,4'-tetrahydroxybenzophenone , 1,2,3-trihydroxybenzophenone, 2,2 ', 4-trihydroxybenzophenone and other hydroxyl group-containing aromatic compounds, hexafluorophosphoric acid, tetrafluoroboric acid and other halogenated Lewis acids, ClO ₄ , Io
Examples thereof include perhalogenic acid such as _{4 and the} like, but are not limited thereto. Among these, particularly preferred are hexafluorophosphoric acid, tetrafluoroboric acid, and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid.

Specific examples of the diazo co-condensation resin in the present invention,
p-Methoxybenzoic acid-4-diazodiphenylamine-
Formaldehyde resin-hexafluorophosphate, p-ethoxybenzoic acid-4-diazophenylamine-formaldehyde resin-hexafluorophosphate, O-, m-, p-methylbenzoic acid-4-diazodiphenylamine-formaldehyde Resin-hexafluorophosphate, o-, m-, p-chlorobenzoic acid-4-
Diazodiphenylamine-formaldehyde resin-hexafluorophosphate, 2,4-dimethoxybenzoic acid-4-diazodiphenyldiamine-formaldehyde resin-hexafluorophosphate, 2,4-dimethoxybenzoic acid-4-diazodiphenylamine-formaldehyde resin -Hexafluorophosphate, terephthalic acid-4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate 4-dimethylaminobenzoic acid-4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate, terephthalic acid-4-diazo Diphenylamine-formaldehyde resin-hexafluorophosphate,
Cinnamic acid-4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate, 1-naphthalenedicarboxylic acid-4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate, o-, m-, p-cyanobenzoic acid-4 −
Diazodiphenylamine-formaldehyde resin-tetrafluoroborate, 3,4 dimethoxybenzoic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, 2,4 dimethylbenzoic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate Borate, 4-
Anilinobenzoic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, p-phenoxybenzoic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, N-phenylglycine-
4-diazodiphenylamine-formaldehyde resin-
Tetrafluoroborate isophthalic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, acetylsalicylic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, 2-naphthalenecarboxylic acid-4-diazodiphenylamine -Formaldehyde resin-tetrafluoroborate, 2,3-naphthalenedicarboxylic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, 2,6-naphthalenedicarboxylic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoride Borate, 4-methoxyphenylacetic acid-4-diazodiphenylamine-formaldehyde resin-2-hydroxy-4-methoxybenzophenone-5-
Sulfonate, p-phenoxyacetic acid-4-diazodiphenylamine-formaldehyde resin-2-hydroxy-
4-methoxybenzophenone-5-sulfonate, etc. are particularly preferable, p-methoxybenzoic acid-4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate, o-, m-, p-chlorobenzoic acid- 4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate, 2,4-dimethoxybenzoic acid-4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate, p-
Methylbenzoic acid-4-diazodiphenylamine-formaldehyde resin-hexafluorophosphate, 2,4-dimethylbenzoic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, 4-anilinobenzoic acid-4-
Diazodiphenylamine-formaldehyde resin-tetrafluoroborate, N-phenylglycine-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate, 2-naphthalenedicarboxylic acid-4-diazodiphenylamine-formaldehyde resin-tetrafluoroborate Is.

The diazo co-condensation resin of the present invention can be obtained as an arbitrary value for its molecular weight by variously changing the molar ratio of each monomer and the condensation conditions, but in order to effectively serve the intended purpose of the present invention. The molecular weight of about 400 to 10,000 can be used, but preferably about 800 to 5,000.
Is appropriate.

The photosensitive diazo resin used in the present invention is usually 1 to 60% by weight, preferably 3 to 30% by weight in the solid content of the photosensitive composition.
% By weight.

The above photosensitive diazo co-condensation resin contains (i) an unsaturated compound having an aromatic hydroxyl group and / or an unsaturated compound having an aliphatic hydroxyl group, and (ii) an α, β-unsaturated carboxylic acid as structural units. An alkali-soluble or swellable lipophilic polymer compound made of a copolymer is used as a binder resin in combination with it. This lipophilic polymer compound usually has a molecular weight of 20,000 to 200,000, and the following (1),
It is a copolymer of one or more monomers selected from the group (2) and the monomer (3).

(1) Acrylamides, methacrylamides, acrylates, and methacrylates having an aromatic hydroxyl group, such as N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide, o- , m-, p-hydroxystyrene, o-, m-, p-hydroxyphenyl-acrylate or methacrylate, (2) acrylic acid ester and methacrylic acid ester having an aliphatic hydroxyl group, for example, 2-hydroxyethyl methacrylate. Alternatively, 2-hydroxyethyl methacrylate, (3) α, β-unsaturated carboxylic acid such as acrylic acid, methacrylic acid, and maleic anhydride, and the following monomers copolymerizable with the above monomers may be copolymerized. .

(4) methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate,
(Substituted) alkyl acrylates such as hexyl acrylate, octyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate, (5) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
(Substituted) alkyl methacrylates such as amyl methacrylate, cyclohexyl methacrylate, 4-hydroxybutyl methacrylate and glycidyl methacrylate, (6) acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-hexyl methacryl Amides, acrylamides or methacrylamides such as N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N-phenylacrylamide, etc. (7) Ethyl vinyl ether, 2-chloroethyl Vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octa Vinyl ethers such as tyl vinyl ether and phenyl vinyl ether (8) Vinyl acetate, vinyl chloroacetate,
Vinyl butyrate, vinyl benzoate, and other vinyl esters, (9) Styrene, α-methylstyrene, methylstyrene, chloromethylstyrene, and other styrenes, (10) Methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl Vinyl ketones such as vinyl ketone, (11) olefins such as ethylene, propylene, isobutylene, butadiene and isoprene, (12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc. Also, the copolymer obtained by copolymerizing the above-mentioned monomers is, for example, modified with glycidyl methacrylate, glycidyl acrylate, etc., but is not limited thereto.

 The preferred acid value of the above copolymer is 10 to 100.

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

If necessary, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, an epoxy resin, a novolak resin, a natural resin, or the like may be added to the copolymer.

The lipophilic polymer compound used in the present invention is usually contained in the solid content of the photosensitive composition at 40 to 99% by weight, preferably 50 to 95% by weight.

The photosensitive composition of the present invention may further contain a dye. The dye is used for the purpose of obtaining a visible image by exposure (exposure visible image) and a visible image after development.

As the dye, those which change color tone by reacting with free radicals or acids can be preferably used. Here, the term “color tone changes” includes both a change from colorless to a color tone and a change from color to colorless or a different color tone. Preferred dyes are those which form a salt with an acid to change the color tone.

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 Red, Brilliant Green, Ethyl Violet, Methyl Violet, Methyl green,
Erythrosine B, basic fuchsin, malachite green, oil red, m-cresol purple, rhodamine B, auramine, 4-p-dieraminophenyliminonaphthoquinone, cyano-p-diethylaminophenylacetanilide, and other triphenylmethanes, diphenylmethanes. Examples of the discoloring agent that changes a colorant from a colorant to a colorless color or a different color tone include a dye of a system, an oxazine, a xanthene, an iminonaphthoquinone, an azomethine, or an anthraquinone.

On the other hand, as a color changing agent that changes from colorless to colored, leuco dye and, for example, triphenylamine, diphenylamine, o-chloroaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane,
p, p'-bis-dimethylaminodiphenylamine, 1,2-
Dianilinoethylene, p, p ', p "-tris-dimethylaminotriphenylmethane, p, p'-bis-dimethylaminodiphenylmethylimine, p, p', p" -triamino-
o-methyltriphenylmethane, p, p'-bis-dimethylaminodiphenyl-4-anilinonaphthylmethane, p,
Primary or secondary arylamine dyes represented by p ', p "-triaminotriphenylmethane are exemplified.

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

The dye is usually contained in the photosensitive composition in an amount of 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 composition of the present invention.

For example, alkyl ethers (eg, ethyl cellulose, methyl cellulose) for improving coating properties, fluorine surfactants, and nonionic surfactants [for example,
Pluronic L-64 (manufactured by Asahi Denka Co., Ltd.)], a plasticizer (for example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, phthalic acid) for imparting flexibility and abrasion resistance to the coating film Dihexyl, dioctyl phthalate, tricresyl phosphate,
Tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid), and a sensitizer for improving the sensitivity of the image area (for example, JP-A-55-527). Styrene-half esterified product of styrene-maleic anhydride copolymer with alcohol), stabilizer [for example, phosphoric acid, phosphorous acid, organic acid (citric acid, oxalic acid, benzenesulfonic acid, naphthalenesulfonic acid, 4- Methoxy-2
-Hydroxybenzophenone-5-sulfonic acid, tartaric acid, etc.)]. The amount of these additives varies depending on the purpose of use, but is generally 0.01 to 30% by weight based on the total solid content.

Such a photosensitive composition is applied on a support.
Examples of the support include a metal plate such as an aluminum plate or its alloy plate, a zinc plate, a copper plate, a stainless plate, or a plastic such as polyethylene terephthalate or 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 for the above-mentioned photosensitive lithographic printing plate includes paper, plastics (for example, polyethylene, polypropylene, polystyrene, etc.) laminated paper, metal such as aluminum (including aluminum alloy), zinc, copper and the like. Plate, cellulose diacetate, cellulose triacetate,
Films of plastics such as cellulose propionate, polyethylene terephthalate, polyethylene, polypropylene, polycarbonate polyvinyl acetal, etc., papers or plastic films laminated or vapor-deposited with the above metals, steel plates plated with aluminum or chrome, etc., Of these, aluminum and an aluminum-coated composite support are particularly preferable.

The surface of the aluminum material is desirably subjected to a surface roughening treatment for the purpose of increasing water retention and improving adhesion to the photosensitive layer.

Examples of the surface roughening method include generally known methods such as brush polishing, ball polishing, electrolytic etching, chemical etching, liquid honing, sand blasting and the like, and combinations thereof. Preferably, brush polishing, electrolytic etching, and chemical polishing are used. Etching and liquid honing, of which the surface roughening method including the use of electrolytic etching is preferred. Further, as an electrolytic bath used in the electrolytic etching, an aqueous solution containing an acid, an alkali or a salt thereof or an aqueous solution containing an organic solvent is used, and among these, an electrolytic solution containing hydrochloric acid, nitric acid or a salt thereof is used. Liquids are preferred. The surface-roughened aluminum plate is desmutted with an acid or alkali aqueous solution as necessary. The aluminum plate thus obtained is desirably subjected to anodic oxidation treatment, and particularly preferably a method of treating the aluminum plate with a bath containing sulfuric acid or phosphoric acid. Further, if necessary, surface treatment such as sealing treatment with alkali silicate or hot water and immersion in a water-soluble polymer compound or an aqueous solution of potassium fluorozirconate can be performed.

In order to provide the above-mentioned photosensitive composition on a support, a photosensitive diazo co-condensation resin, a lipophilic polymer compound and, if necessary, various additives in predetermined amounts are added in an appropriate solvent (methyl cellosolove, ethyl cellosolove, methyl). Cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethylsulfoxide, water or a mixture thereof) to prepare a coating solution of the photosensitive composition, which is coated on a support and dried. The concentration of the photosensitive composition at the time of coating is preferably in the range of 1 to 50 weight. In this case, the application amount of the photosensitive composition may be approximately 0.2 to 10 g / m ² .

A conventional method is applied to the photosensitive material coated on the support. That is, by exposing through a transparent original image having a line image, a halftone dot image, and the like, and then developing with an aqueous developer, a negative relief image with respect to the original image is obtained. As a light source of active light suitable for exposure, a carbon arc lamp,
Examples include a mercury lamp, a xenon lamp, a metal halide lamp, and a strobe.

The developer used for developing the photosensitive composition according to the present invention contains a specific organic solvent, an alkaline agent, and water as necessary components. Here, the specific organic solvent is capable of dissolving or swelling the above-mentioned non-exposed portion (non-image portion) of the photosensitive composition layer when it is contained in a developing solution, and furthermore, water at normal temperature (20 ° C.) Refers to an organic solvent having a solubility in water of 10% by weight or less. Such an organic solvent only needs to have the above-mentioned characteristics, and is not limited to the following, but if these are exemplified, for example, ethyl acetate, propyl acetate, acetic acid, etc. Carboxylic esters such as butyl, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, butyl levulinate: ethyl butyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone: ethylene glycol monobutyl ether, ethylene glycol benzyl Alcohols such as ethers, ethylene glycol monophenyl ether, benzyl alcohol, methylphenylcarbinol, n-amyl alcohol, methylamyl alcohol: alum-substituted aromatic hydrocarbons such as xylene: methylene Chloride, ethylene dichloride, and the like halogenated hydrocarbons such as 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 generally 1 to 20% by weight, particularly 2 to 10% by weight.
More favorable results are obtained when the weight% is used.

On the other hand, the alkaline agent contained as an essential component in the developer includes (A) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium of secondary or tertiary phosphate or (B) mono-, di- or trimethylamine, mono-, di- or triethylamine, mono- or diisopropylamine, inorganic alkali agents such as ammonium salts, sodium metasilicate, sodium carbonate, and ammonium
-Butylamine, mono, di or triethanolamine,
Organic amine compounds such as mono-, di- or tri-isopropanolamine, ethyleneimine, ethylenediamine and the like can be mentioned.

The content of these alkali agents in the developer is usually 0.1.
It is from 0.5 to 4% by weight, preferably from 0.5 to 2% by weight.

In order to further improve the storage stability, printing durability and the like, it is preferable to include a water-soluble sulfite in the developer. As such a water-soluble sulfite, an alkali or alkaline earth metal sulfite is preferable, and examples thereof include sodium sulfite, potassium sulfite, lithium sulfite, and magnesium sulfite. 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 developing solution is brought into contact with the photosensitive composition after development exposure, or if it is rubbed with the developing solution, the exposed portion of the photosensitive composition is adversely affected after about 10 to 60 seconds at room temperature to 40 ° C. The photosensitive composition in the non-exposed area is completely removed without affecting the temperature, and a photosensitive lithographic printing plate is obtained.

〔Example〕

Next, examples will be shown to clarify the effects of the present invention.
The present invention is not limited to these examples. Diazo resin-1
Synthesis of p-ethoxybenzoic acid 2.08 g (12.5 mmol) and 4
-Diazodiphenylamine sulfate 10.2 g (35 mmol)
Was dissolved in 40.9 g of concentrated sulfuric acid under ice cooling. Laformaldehyde (1.35 g, 45 mmol) was slowly added dropwise to the reaction solution. At this time, the reaction was added so that the reaction temperature did not exceed 10 ° C. After that, stirring was continued under ice cooling. This reaction mixture was poured into 1 ethanol under ice cooling, and the generated precipitate was filtered. After washing with ethanol, it was dissolved in 100 ml of pure water, and to this liquid was added a cold concentrated aqueous solution in which 6 g of chlorous chloride was dissolved. The precipitate formed is filtered and washed with ethanol, which is
It was dissolved in 150 ml of pure water.

To this solution was added a cold concentrated aqueous solution in which 6.9 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate is filtered,
After washing, it was dried at 30 ° C. for one day to obtain diazo resin-1. The weight average molecular weight of this was measured by GPC (gel permeation chromatography)
It was 2100.

Synthesis of diazo resin-2 p-Ethoxybenzoic acid was mixed with 1.96 g of p-chlorobenzoic acid (1
Diazo resin-2 was obtained in the same manner as in the synthesis of diazo resin-1 except that the amount was changed to 2.5 mmol). When the molecular weight was measured by GPC, the weight average molecular weight was about 2000.

Synthesis of diazo resin-3 p-Ethoxybenzoic acid was added to p-methylbenzoic acid 1.7 g (1
Diazo resin 3 was obtained in the same manner as in the synthesis of diazo resin-1 except that the amount was changed to 2.5 mmol). When the molecular weight was measured by GPC, the weight average molecular weight was about 2200.

Synthesis of diazo resin-4 4-anilinobenzoic acid 2.67 g of p-ethoxybenzoic acid
(12.5 mmol) and ammonium tetrafluoroborate were replaced with ammonium tetrafluoroborate (4.45 g), except that diazo resin-1 was prepared in the same manner as in the synthesis of diazo resin-1.
4 was obtained. GPC measurement showed a weight average molecular weight of about 2400
Met.

Synthesis of diazo resin-5 4-anilinobenzoic acid was added to N-phenylglycine 1.89.
Diazo resin-5 was obtained in the same manner as diazo resin-4 except that g (12 mmol) was replaced. When the molecular weight was measured by GPC, the weight average molecular weight was about 2100.

Synthesis of diazo resin-6 (comparative diazo resin) Without using p-ethoxybenzoic acid, 14.5 g (50 mmol) of p-diazodiphenylamine sulfate, 1.5 g (50 mmol) of paraformaldehyde and 6.8 g of zinc chloride. , Except that ammonium hexafluorophosphate was replaced with 8 g,
Diazo resin-6 was obtained in the same manner as diazo resin-1.
When the molecular weight was measured by GPC, the weight average molecular weight was about 2500.

Synthesis of diazo resin-7 (comparative diazo resin) Diazo resin-7 was obtained in the same manner as the synthesis of diazo resin-6 except that the amount of paraformulaldehyde was 1.05 g (35 mmol). When the molecular weight was measured by GPC, the weight average molecular weight was about 1600.

[Synthesis of lipophilic polymer chemistry 1] N- (4-hydroxyphenyl) methacrylamide 1
0.0 g, acrylonitrile 25 g, ethyl acrylate 60 g,
Methacrylic acid 5 g and azobisisobutyronitrile 1,64
Dissolve 2 g of acetone-methanol 1: 1 mixed solution 112 ml,
After purging with nitrogen, the mixture was heated at 60 ° C. for 8 hours.

After the reaction was completed, the reaction solution was poured into water 5 with stirring, and the white precipitate formed was collected by filtration 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 compound 2] 45 g of 2, -hydroxyethyl methacrylate, 10 g of acrylonitrile, 35 g of ethyl methacrylate, methacrylic acid
A mixed solution of 10 g and 1.2 g of benzoyl peroxide was added dropwise to 300 g of ethylene glycol monomethyl ether heated to 100 ° C. over 2 hours. After completion of the dropwise addition, 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 completion of the reaction, the mixture was diluted with methanol, poured into water 5 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 80,000.

[Production of grain]

The aluminum plate was degreased with a 3% aqueous sodium hydroxide solution, and this was electrolytically etched in a 2% hydrochloric acid bath at 25 ° C and a current density of 100 A / dm ² , and then washed with water and washed with a 30% sulfuric acid bath with 30%.
It was anodized for 30 seconds in a sulfuric acid bath at 30 ° C. and 1.5 A / dm ² . Then, a re-solution of 15 sodium metasilicate was sealed at 85 ° C. for 30 seconds, washed with water and dried to obtain an aluminum plate for lithographic printing.

Examples 1 to 5 and Comparative Examples 1 to 3 The aluminum plate for lithographic printing obtained as described above was coated with a photosensitive solution having the following composition to give a coating film weight of 1.69 / m 2.
^It was applied so as to be ² .

Photosensitive composition Lipophilic polymer 5.0g Diazo resin 0.6g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.)
0.1g Diurimer Ac-10L (manufactured by Nippon Pure Chemical Co., Ltd.) 0.3g Methyl cellosolve 100ml The combination of lipophilic polymer and diazo resin is shown in Table-
1 is shown.

The thus-obtained photosensitive lithographic printing plate was brought into close contact with a negative transparent original image and a step wedge (optical density increased stepwise by 0.15), and exposed for 30 seconds from a distance of 60 cm with a 2 KW metal halide lamp, Developer with the following composition
Development was carried out at 1 and the sensitivity was examined. Next, in order to examine the diazo residue of the non-image area, half of the non-image area of the printing plate thus obtained was re-exposed and compared with the non-re-exposed area. Furthermore, in order to check the underdeveloping property,
As Nos. 2 and 3, the developing solution-1 was developed using a diluted developing solution obtained by diluting the developing solution-1 with an equal volume and twice the amount of pure water, and the developing property (dirt) of the non-image area was observed. Further, the above-mentioned photosensitive lithographic printing plate was forcibly stored (55 ° C., humidity 10% RH or less, for 3 days), and using the developer-2, the developability of the non-image area was similarly observed.

Composition of Developer-1 Benzyl alcohol 50g Triethanolamine 15g Sodium sulfite 5g Sodium butylnaphthalene sulfonate 25g Water 1000g (Development condition: develop for 40 seconds at 25 ° C) Next, apply each photosensitive solution to check the dot thickening. UGRA plate control wedge PCW82 (manufactured by Mika Denshi Co., Ltd.) was closely adhered to the photosensitive lithographic printing plate obtained in this way, and exposed for 5 steps to develop with current liquid-1 and Sakura Area Duck 10
The dot weight of the printing plate was measured with 00 (manufactured by Konica Corp.).
These results are summarized in Table-1.

(Effect of the invention) As shown in Table 1, according to the present invention, the underdeveloping property is good, there is no diazo residue, and the dot thickness is small, that is,
A photosensitive lithographic printing plate excellent in tone reproducibility is obtained, which is industrially very useful.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masafumi Uehara, No. 1, Sakura-cho, Hino-shi, Tokyo, Konica stock company (72) Inventor, Shinichi Matsubara, No. 1, Sakura-cho, Hino-shi, Tokyo, Konica stock company (56) References JP-A-2-4258 (JP, A) JP-A-1-254949 (JP, A) JP-A-1-102457 (JP, A) JP-A-59-97136 (JP, A) JP-A-54 -156522 (JP, A) JP-B-49-48001 (JP, B1)

Claims (1)

(57) [Claims] 1. A photosensitive composition containing a photosensitive diazo resin, comprising: (A) an aromatic water compound having at least one carboxylic acid group and an aromatic diazo compound having no alkoxy group as the diazo resin. (B) (i) an unsaturated compound having an aromatic hydroxyl group and / or containing only a co-condensed diazo resin co-condensed with an aldehyde or a ketone
Alternatively, a photosensitive composition containing an unsaturated compound having an aliphatic hydroxyl group and (ii) a copolymer containing α, β-unsaturated carboxylic acid as a structural unit