JPH0345822B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive composition, and particularly to a photosensitive composition suitably used in a photosensitive lithographic printing plate. More specifically, the present invention relates to a photosensitive composition with improved storage stability. The majority of compounds used as photosensitive substances in pre-sensitized printing materials are diazonium compounds, the most commonly used of which is the formaldehyde condensate of p-diazodiphenylamine. There are diazo resins. When such a diazo resin is coated on a suitable support such as paper, plastic or metal and exposed to actinic light through a transparent negative, the diazo resin in the exposed areas decomposes and becomes insoluble. do. On the other hand, the surface of the support is exposed by dissolving and removing the unexposed areas with water. If a support having a surface that has been previously subjected to a hydrophilic treatment is used, the hydrophilic layer will be exposed in the unexposed areas through development. Therefore, on an offset printing press, this area receives water and repels ink. In addition, the decomposed portion of the diazo resin exhibits lipophilic properties, repelling water and accepting ink. In other words, such printing materials give so-called negative-positive printing plates. Since such photosensitive compositions have low storage stability, various attempts have been made to improve them, but none have yet yielded satisfactory results, particularly in terms of storage stability under high temperature and humidity. . Therefore, an object of the present invention is to provide a photosensitive composition with excellent storage stability, and in particular a photosensitive composition containing a diazo compound that does not deteriorate in performance even after being stored at high temperature and high humidity for a long time. An object of the present invention is to provide a composition. As a result of intensive research, the present inventors have found that a polymer compound having a hydroxyl group and a diazo resin represented by the following general formula, and containing 90 mol% or more of n in the formula, are 1 to 5. It has been found that the objects of the present invention are achieved by a photosensitive composition having the following characteristics. General formula () [In the formula, R ₁ is an alkyl group having 1 to 3 carbon atoms, R ₂ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group, X is an aromatic sulfonic acid, and n is an integer of 1 or more. ] Specific examples of R ₁ include methyl group, ethyl group,
Contains n-propyl group, iso-propyl group, etc.
Specific examples of R ₂ include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, a phenyl group, and the like. Among these, particularly preferred are those in which R ₁ is a methyl group and R ₂ is a hydrogen atom or a methyl group. Specific examples of
-Sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-
Chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-chloro-5-nitrobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, 1-naphtho-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl- These include benzenesulfonic acid and para-toluenesulfonic acid. Among these, particularly preferred are:
2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid. The diazo resin used in the present invention (hereinafter referred to as the diazo resin of the present invention) is, for example, 3-methoxy-4-diazodiphenylamine, 3-ethoxy-4-diazodiphenylamine, 3-(n-
A diazo monomer such as propoxy)-4-diazodiphenylamine, or 3-(iso-propoxy)-4-diazodiphenylamine and formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, iso-butyraldehyde, or Reaction of a condensate obtained by condensing a condensing agent such as benzaldehyde in a molar ratio of 1:1 to 1:0.5, preferably 1:0.8 to 1:0.6, in a conventional manner with an aromatic sulfonate. It is a product. When the condensation ratio exceeds 1:1, the resulting diazo resin has poor solubility in organic solvents,
If the ratio is less than 1:0.5, the mechanical strength of the exposed area of the photosensitive composition will be insufficient, making it unsuitable for the photosensitive composition of the present invention. It is necessary for the diazo resin of the present invention to be contained in the photosensitive composition in an amount of 0.1% by weight or more from the viewpoint of sufficient visible image quality, but if it exceeds 50% by weight, the sensitivity of the photosensitive composition decreases. Because it comes
Preferably it does not exceed 50% by weight. A more preferred content of the diazo resin of the present invention ranges from about 3 to about 20% by weight. In addition to the diazo resin of the present invention, diazo compounds such as those described in JP-A-50-118802, JP-B-52-7364, etc. can be appropriately used in combination. Examples of the polymer compound having a hydroxyl group used in the present invention include a copolymer of a monomer represented by the following general formula () and another monomer. General formula () (In the general formula (), R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, and n represents an integer of 1 to 10.) Other monomers for combination include, for example, acrylonitrile, methacrylonitrile, acrylic esters, acrylamides, methacrylic esters, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonic esters, etc. is selected from compounds having one addition-polymerizable unsaturated bond. Specifically, for example, acrylic esters, such as alkyl acrylates (e.g., methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, ethylhexyl acrylate, octyl acrylate, t-acrylate) Octyl, chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropanoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate,
methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.): aryl acrylate (e.g. phenyl acrylate, etc.); methacrylic acid esters,
For example, alkyl methacrylates (e.g. methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl acrylate, etc.), aryl methacrylate (e.g., phenyl methacrylate, cresyl methacrylate, naphthyl methacrylate, etc.); acrylamides, such as acrylamide,
N-alkylacrylamide (such alkyl groups include, for example, methyl group, ethyl group, propyl group, butyl group, t-butyl group, heptyl group, octyl group, cyclohexyl group, hydroxyethyl group, benzyl group, etc.) , N-arylacrylamide (the aryl group includes, for example, a phenyl group, tolyl group, nitrophenyl group, naphthyl group, hydroxyphenyl group, etc.)N-N
- dialkylacrylamide (such alkyl groups include methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group, cyclohexyl group, etc.), N/N-diarylacrylamide (such as phenyl group, etc.) ), N-methyl-N-phenylacrylamide, N-hydroxyethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide, etc.; methacrylamides, such as methacrylamide, N-alkylmethacryl amide (such alkyl groups include methyl, ethyl, t-butyl, ethylhexyl, hydroxyethyl, cyclohexyl, etc.), N-arylmethacrylamide (such aryl groups include phenyl, etc.); be.)
N/N-dialkyl methacrylamide (such alkyl groups include ethyl, propyl, butyl, etc.), N/N-diaryl methacrylamide (such aryl groups include phenyl, etc.)N -hydroxyethyl-N-methylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-ethyl-N-phenylmethacrylamide, etc.; allyl compounds, such as allyl esters (such as allyl acetate, allyl caproate,
allyl caprylate, allyl laurate, allyl palmitylate, allyl stearate, allyl benzoate, allyl acetone acetate, allyl lactate, etc.), allyloxyethanol, etc.; vinyl ethers,
For example, alkyl vinyl ethers (e.g. hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyvinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethyl butyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.), vinyl aryl ether (such as vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl 2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthrani ether, etc.); vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valerate, vinyl caproate, Vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxy acetate, vinyl butoxy acetate,
Vinyl phenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenyl butyrate, vinyl cyclohexyl carboxylate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate, etc.; styrene such as styrene, alkylstyrenes (such as methylstyrene, dimethylstyrene, trimethylstyrene,
Ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene,
benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene, etc.), alkoxystyrenes (e.g., methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene, etc.), halogenostyrenes (e.g., chlorostyrene, Dichlorostyrene, trichlorstyrene, tetrachlorostyrene, bentachlorstyrene, bromstyrene, dibromstyrene, iodostyrene, fluorostyrene, trifluorstyrene,
2-bromo-4-trifluoromethylstyrene,
4-fluoro-3-trifluoromethylstyrene, etc.); crotonate esters, such as alkyl crotonates (such as butyl crotonate, hexyl crotonate, glycerin monocrotonate, etc.); dialkyl itaconates (such as dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.); dialkyl maleic acid or fumaric acid (for example, dimethyl maleate, dibutyl fumarate, etc.); Other addition-polymerizable unsaturated compounds that are generally copolymerizable with the compound represented by the above general formula () may be used. It also includes homopolymers and copolymers of the monomers represented by the general formula (), and resins obtained by partially esterifying or etherifying aromatic hydroxyl groups such as phenol novolak. However, the structural unit (monomer) represented by the general formula () contained in the polymer is 1 to 80 mol%, preferably 5
~60 mol%. If the structural unit content is less than 1 mol%, there is a problem with storage stability, and if it exceeds 80 mol%, the exposed area will dissolve to provide a positive-positive type photosensitive copying layer, and the photosensitive copying layer of the present invention may It becomes unsuitable as a composition. In addition to the above-mentioned polymer compounds, monomer units having an aromatic hydroxyl group, such as those described in polyvinyl butyral resin, polyvinyl formal resin, Sierra Tsukuba, or Japanese Patent Application Laid-Open No. 54-98614, can be used in polymer structural formulas such as those described in JP-A-54-98614. The polymer contained therein can also be used as the hydroxyl group-containing polymer compound of the present invention. The polymer compound having a hydroxyl group used in the present invention is contained in a photosensitive composition of about 50 to 99.5
by weight, preferably about 55-95% by weight. The photosensitive compositions of the present invention may further include dyes, PH
Additives can be included, such as indicators, phosphoric acid as described in US Pat. No. 3,236,646. In the present invention, the photosensitive composition containing a diazo resin and a polymeric compound having a hydroxyl group is coated on a substrate such as an aluminum plate, other metal plate, plastic film, etc. after adding additives if necessary and dissolving it in a solvent. It can be dried to form a photosensitive lithographic printing plate. The coating amount is usually about 0.5 to about 6 g/m ² in terms of dry weight, preferably about 0.3 to about 3.0 g/m ² . Next, the present invention will be explained in more detail with reference to Examples, but the embodiments of the present invention are not limited thereto. Example 1 A 0.15 mm thick 2S aluminum plate was degreased by immersing it in a 10% aqueous solution of tribasic sodium phosphate kept at 80°C for 3 minutes, then grained with a nylon brush, and then soaked in sodium aluminate at 60°C. It was etched for about 10 seconds and then desmatted with a 3% aqueous solution of sodium hydrogen sulfate. This aluminum plate was heated at 2A/d in 20% sulfuric acid.
m ² for 2 minutes, and then treated with a 2.5% sodium silicate aqueous solution at 70° C. for 1 minute to produce an anodized aluminum plate ( ). A photosensitive liquid having the following composition was applied to this aluminum plate (2) using a foiler. The photosensitive solution was then dried for 2 minutes at 100°C.
From Example 1, photosensitive lithographic printing plate A was obtained. As a comparative example, a photosensitive lithographic printing plate B was obtained from photosensitive liquid-2 in the same manner as above. Both coating weights after drying are
It was 2.0g/ ^m2 . Photosensitive liquid 1 Copolymer 1 5.0g Diazo resin 1 0.5g Oil Blue #603 (dye manufactured by Orient Chemical Industry Co., Ltd.) 0.1g Silk acid 0.05g Methyl cellosolve 100g However, the above copolymer-1 has a molar ratio of 2-hydroxyethyl methacrylate/acrylonitrile/methyl methacrylate/methacrylic acid=1
Diazo resin-1 has a composition of 0/50/30/10, and diazo resin-1 is a condensate of 3-methoxy-4-diazodiphenylamine and paraformaldehyde in a molar ratio of 1:0.6. -Methoxy-4-hydroxy-5-benzoylbenzene sulfonate. The molecular weight distribution of this diazo resin 1 was analyzed using gel permeation chromatography (GPC).
As a result of measurement, 95 mol% of the total amount was 5-mer or less. Photosensitive liquid 2 Diazo resin-1 of photosensitive liquid-1 was replaced with diazo resin-2
Everything else is the same as photosensitive liquid-1 except that it was replaced with . However, the above-mentioned diazo resin-2 is obtained by replacing 3-methoxy-4-diazodiphenylamine of the above-mentioned diazo resin-1 with p-diazodiphenylamine. Photosensitive lithographic printing plates A and B thus obtained
After leaving it at 40℃ and 80% RH for 5 days, it was image-exposed for 1 minute from a distance of 1 m using Fuji Photo Film Co., Ltd.'s PS light, and then immersed in the following developer for 1 minute at room temperature. The surface was lightly rubbed with absorbent cotton and the unexposed areas were removed to obtain lithographic printing plates A and B, respectively. Sodium sulfite 5g Benzyl alcohol 30g Sodium carbonate 5g Sodium isopropylnaphthalene sulfonate
12g Water 1000g When these lithographic printing plates A and B were printed on high-quality paper using commercially available ink using a Heidelberg GTO printing machine, the printed matter printed by printing plate B had scumming, but No scumming was observed in the printed matter printed from printing plate A, and 100,000 good quality printed matter were obtained. Example 2 Copolymer-1 in photosensitive liquid-1 in Example 1
A photosensitive lithographic printing plate C was obtained in the same manner as in Example 1, except that Copolymer-2 was used, and this plate was made and printed in the same manner. As in Example 1, no scumming occurred at all. 80,000 good quality prints were obtained. However, the copolymer-2 has a molar ratio of p-hydroxyphenylacrylamide/acrylonitrile/methyl methacrylate/methacrylic acid=30/30/30/10. Example 3 Diazo resin in photosensitive liquid 1 in Example 1
Photosensitive lithographic printing plates D to G were obtained in the same manner as in Example 1, except that 1 was replaced with the following diazo resins 3 to 6, and when these plates were made and printed in the same manner, good results were obtained with no scumming. Obtained many printed materials. 【table】

Claims (1)

[Scope of Claims] 1. A polymer compound having a hydroxyl group and a diazo resin represented by the following general formula and containing 90 mol% or more of n in the formula from 1 to 5. Photosensitive composition. general formula [In the formula, R ₁ is an alkyl group having 1 to 3 carbon atoms, R ₂ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a phenyl group, X is an aromatic sulfonic acid, and n is an integer of 1 or more. ]