JPH0544018B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a photosensitive composition suitable for a photosensitive lithographic printing plate. More specifically, the present invention relates to an alkaline water-soluble photocrosslinkable photosensitive composition that has improved adhesion to aluminum substrates. [Prior Art] Photocrosslinkable materials that crosslink through a cycloaddition reaction are well known, and these are used as image forming materials for printing plates, LSI devices, and the like. Among these photocrosslinkable materials, photosensitive resins having cinnamyl groups, cinnamylidene groups, chalcone groups, etc. in their side chains or main chains, which have a photodimerizable unsaturated double bond adjacent to an aromatic nucleus, are useful and have not been put into practical use. Some have been. Generally, in order to coat a photosensitive resin on an aluminum substrate and use it as a printing plate, it must be developable in alkaline water and have sufficient adhesive strength with the aluminum substrate, from the viewpoint of not generating wastewater pollution. The above-mentioned photosensitive resins have a problem in this respect, and because they are not commonly used as photosensitive layers for printing plates, they have been used only in some applications. For the purpose of improving the above-mentioned drawbacks, for example, Japanese Patent Application Laid-Open No. 58-49940 discloses that the main chain or side chain is photodimerizable.

[Structure of the invention]

The object of the present invention is to () have at least two
It has a photodimerizable unsaturated double bond adjacent to two aromatic nuclei, has at least one carboxyl group in its side chain, and is soluble or swellable in alkaline water with an acid value of 20 to 200. This is achieved by a photosensitive composition consisting of a molecular compound, () a negative-acting diazo resin and () optionally a photosensitizer. The photosensitive polymer compound that is soluble or swellable in alkaline water for use in the present invention is
A polyester prepolymer having a photodimerizable unsaturated double bond adjacent to an aromatic nucleus in the main chain, a carboxyl group in the side chain, and a hydroxyl group at the end as described in the specification of No. 191244 is prepared by reacting with a hydroxyl group. A photosensitive polymer compound obtained by reacting a chain extender having two or more functional groups in the molecule, such as a diisocyanate compound, diphenyl terephthalate, diphenyl carbonate, or terephthaloyl bis(N-caprolactam); Pyromellitic dianhydride or cyclopentanetetracarboxylic dianhydride is used as a chain extender for polyester prepolymers and polyurethane prepolymers that have a photodimerizable unsaturated double bond adjacent to an aromatic nucleus and a hydroxyl group at the end in the main chain. Examples include photosensitive polymer compounds in which a carboxyl group is introduced into the side chain by reacting with . In addition, a photosensitive polymer compound made of a polyurethane having a carboxyl group in the side chain, which is obtained by mixing the above-mentioned polyester prepolymer having a hydroxyl group with a diol having a carboxylic acid, such as dimethylolpropionic acid, and reacting the mixture with a diisocyanate, is also useful. be. Specifically, a dicarboxylic acid, dicarboxylic acid ester, or dicarboxylic acid chloride having a photodimerizable unsaturated double bond adjacent to an aromatic nucleus is reacted with an excess polyhydric alcohol component to synthesize a polyester prepolymer with terminal hydroxyl groups. Then, the same mole of a compound having two cyclic acid anhydride residues per molecule was reacted, or the same mole or less of a compound having two cyclic acid anhydride residues per molecule was reacted. rear,
After reacting with a diisocyanate compound, diphenyl terephthalate, diphenyl carbonate, terephthaloyl bis(N-caprolactam), etc. as a chain extender, or reacting the above polyester prepolymer with a terminal hydroxyl group with an equivalent mole or less of diisocyanate, 2 per molecule as a chain extender
A photosensitive polymer compound having a carboxyl group in a side chain is obtained by reacting a compound having a cyclic acid anhydride residue. Among these photosensitive polymer compounds, those prepared by mixing a polyester prepolymer having a hydroxyl group at the end with a diol having a carboxylic acid and then reacting the same amount of diisocyanate with respect to the hydroxyl group can easily be converted into a polymer. It is highly sensitive and particularly useful. Examples of carboxylic acids having a photodimerizable unsaturated double bond adjacent to an aromatic nucleus include those having the following structural formulas. (In the above general formulas (1) to (7), R ₁ and R ₁ ' each represent an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, or a nitro group,
R ₃ represents an alkylene group having 2 to 4 carbon atoms, and n
and n' represents an integer from 1 to 4. n or n' is 2~
4, R ₁ or R ₁ ' may be the same or different. ) Preferred examples of the dicarboxylic acids or derivatives thereof include P-phenylene diacrylic acid, 2,5-dimethoxy-P-phenylene diacrylic acid, P-carboxycinnamic acid, and bis(p-cinnamic acid) diethylene glycol ether. dicarboxylic acids such as and derivatives thereof. On the other hand, as the polyhydric alcohol component, various types can be used without particular limitations, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol,
1,3-butylene glycol, 1,6-hexanediol, 2-butene-1,4-diol, 2,
2,4-trimethyl-1,3-pentanediol, 1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, bisphenol A There are ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, ethylene oxide adducts of hydrogenated bisphenol A, propylene oxide adducts of hydrogenated bisphenol A, and the like. In addition, dimethylolpropionic acid, diol having a carboxylic acid group, etc. can be given. (n is an integer of 1 to 5) Examples of compounds having two cyclic acid anhydride groups in one molecule include pyromellitic dianhydride, 1,2,3,
4-cyclopentanetetracarboxylic dianhydride,
3,3',4,4'-diphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride Examples include acid dianhydrides. Among them, particularly when used as a chain extender, dianhydrides with high purity (low anhydride content) are used.
90% or more) must be used. As the chain extender used in the present invention, one molecule contains two
aryl ester group, aryl carbonate group, N-acyllactam group, N-acylimide group, benzoxazinone group, isocyanate group, oxazolonine group, N-acylimidazole group, silanol group, furoxane group, aziridine group, iso Thiocyanate group, vinyl ether group,
Examples include compounds having a ketene acetal group, an unsaturated cycloacetal group, and a carboimide group. Among these, diisocyanate compounds are particularly suitable. Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, 4,
4'-diphenylmethane diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate, isophorone diisocyanate,
Examples include 4,4'-methylenebis(cyclohexyl isocyanate). The molecular weight of these photosensitive polymer compounds can be adjusted by adjusting the amount of chain extender added, but the molecular weight suitable for the photosensitive composition of the present invention is 2000 to 2000.
200000. More preferably, it is 10,000 to 100,000. In addition, the acid value of these photosensitive polymers is 20~
An acid value of 200 or less is preferable, and an acid value of less than 20 is not preferable because the solubility in alkaline water decreases. Further, if the acid value is higher than 200, the photocured photosensitive layer will swell significantly with alkaline water, which is not preferable. Suitable negative-acting diane resins for use in the present invention are those that are substantially water-insoluble and soluble in organic solvents. As such diazo resin, 4-
Diazodiphenylamine, 1-diazo-4-
N,N-dimethylaminobenzene, 1-diazo-
4-N,N-diethylaminobenzene, 1-diazo-4-N-ethyl-N-hydroxyethylaminobenzene, 1-diazo-4-N-methyl-N-
Hydroxyethylaminobenzene, 1-diazo-
2,5-diethoxy-4-benzoylaminobenzene, 1-diazo-4-N-benzylaminobenzene, 1-diazo-4-morpholinobenzene,
1-Diazo-2,5-dimethoxy-4-p-tolylmercaptobenzene, 1-diazo-2-ethoxy-4-N,N-dimethylaminobenzene, p-
Diazo-dimethylaniline, 1-diazo-2,5
-dibutoxy-4-morpholinobenzene, 1-
Diazo-2,5-diethoxy-4-morpholinobenzene, 1-diazo-2,5-dimethoxy-4
-morpholinobenzene, 1-diazo-2,5-
Diethoxy-4-morpholinobenzene, 1-diazo-2,5-diethoxy-4-p-tolylmercaptobenzene, 1-diazo-3-ethoxy-4
-N-methyl-N-benzylaminobenzene, 1
-Diazo-3-chloro-4-N,N-diethylaminobenzene, 1-diazo-3-methyl-4-pyrrolidinobenzene, 1-diazo-2-chloro-4
-N,N-dimethylamino-5-methoxybenzene, 1-diazo-3-methoxy-4-pyrrolidinobenzene, 3-methoxy-4-diazodiphenylamine, 3-ethoxy-4-diazodiphenylamine, 3 A diazo monomer such as -(n-propoxy)-4-diazodiphenylamine, 3-(n-isopropoxy)-4-diazodiphenylamine and formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, or Examples include salts of condensates and acids obtained by condensing condensing agents 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. Examples of acids include tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitroortho-toluenesulfonic acid, 5-sulfosalicylic acid value, 2,5-dimethylbenzenesulfonic acid, 2,
4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-
Examples include fluorocaprinaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and para-toluenesulfonic acid. Among these, alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid are particularly suitable. The amount of these diazo resins added to the total composition is 0.1 to 15% by weight, more preferably 0.3 to 5% by weight.
Weight % is appropriate. Photosensitizers that can be used as necessary in the present invention include benzophenone derivatives, benzanthrone derivatives, quinones, aromatic nitro compounds, naphthothiazoline derivatives, benzothiazoline derivatives, thioxanthones, ketocoumarin compounds, naphthofuranone compounds, pyrylium salts, Thiapyrylium salt etc. can be given. Specifically, Michler's ketone, N,N'-diethylaminobenzophenone, benzanthrone, (3-methyl-1,
3-Diaza-1,9-benz)anthrone picramide, 5-nitroacenaphthene, 2-chlorothioxanthone, 2-isopropylthioxanthone,
Dimethylthioxanthone, methylthioxanthone-1-ethylcarboxylate, 2-nitrofluorene, 2-dibenzoylmethylene-3-methylnaphthothiazoline, 3,3-carbonyl-bis(7-diethylaminocoumarin), 2,4,6-trif Examples include enylthiapyrylium perchlorate. The appropriate amount of these sensitizers added is 1 to 20% by weight, more preferably 3 to 10% by weight of the total composition. In addition to the above, it is preferable to further add a thermal polymerization inhibitor to the photosensitive layer, such as hydroquinone,
p-methoxyphenol, di-t-butyl-p-
Cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis(3-methyl-6-t-butylphenol), 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2 -Mercaptobenzimidazole and the like are useful, and in some cases, dyes or pigments and a PH indicator as a printing agent may be added for the purpose of coloring the photosensitive layer. Further, as a stabilizer for the diazo resin, phosphoric acid, phosphorous acid, tartaric acid, citric acid, malic acid, dipicolinic acid, polynuclear aromatic sulfonic acid and its salts, sulfosalicylic acid, etc. can be added as necessary. The above-mentioned photosensitive composition may be used, for example, with 2-methoxyethanol, 2-methoxyethyl acetate, propylene glycol monomethyl ether,
The solution is coated on a support by dissolving it in a suitable solvent such as 3-methoxypropanol, 3-methoxypropyl acetate, methyl ethyl ketone, ethylene dichloride, etc. alone or in a mixed solvent of a suitable combination thereof. The amount of coverage is approximately 0.1 by weight after drying.
A range of from g/m ² to about 10 g/m ² is suitable, more preferably from 0.5 to 5 g/m ² . Suitable supports for coating the photosensitive compositions of the invention are dimensionally stable plates. Such dimensionally stable plate-like materials include those conventionally used as supports for printing plates, and they can be suitably used in the present invention. Such supports include paper, paper laminated with plastic (e.g. polyethylene, polypropylene, polystyrene, etc.), plates of metals such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose diacetate, triacetic acid. Films of plastics such as cellulose, cellulose propionate, cellulose acetate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.; papers or plastics laminated or vapor-deposited with metals such as those mentioned above; Includes films, etc. Among these supports, aluminum plates are particularly preferred because they are extremely dimensionally stable and inexpensive. Furthermore, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 is also preferred. In addition, in the case of a support having a metal surface, especially aluminum, surface treatments such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, etc., or anodization treatment are performed. Preferably. In addition, as described in U.S. Patent No. 2,714,066, an aluminum plate is grained and then immersed in an aqueous sodium silicate solution, and an aluminum plate is anodized as described in Japanese Patent Publication No. 47-5125. After treatment, those treated by immersion in an aqueous solution of an alkali metal silicate are also suitably used. The above-mentioned anodizing treatment is carried out by electrolysis using an aqueous solution or a non-aqueous solution of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, boric acid, etc., or an organic acid such as oxalic acid, sulfamic acid, or a salt thereof alone or in combination of two or more kinds. This is carried out by passing an electric current through a liquid using an aluminum plate as an anode. Also effective is silicate electrodeposition as described in US Pat. No. 3,658,662. Furthermore, Japanese Patent Publication No. 1974-27481, Japanese Patent Application Publication No. 1973-
Also useful is a surface treatment that combines a support coated with electrolytic grains with the above-mentioned anodic oxidation treatment and sodium silicate treatment as disclosed in JP-A-58602 and JP-A-52-30503. Furthermore, it is also preferable to use brush grain, electrolytic grain, anodic oxidation treatment, and sodium silicate treatment as disclosed in JP-A-56-28893. Furthermore, after these treatments, it is also suitable to apply an undercoat with a water-soluble resin such as polyvinylphosphonic acid, a polymer or copolymer having a sulfonic acid group in the side chain, polyacrylic acid, or the like. These hydrophilic treatments are performed not only to make the surface of the support hydrophilic, but also to prevent harmful reactions with the photosensitive composition provided thereon, and to improve the adhesion with the photosensitive layer. This is done for the purpose of improving the quality of life. A photosensitive plate having the photosensitive composition of the present invention provided on a support is imagewise exposed using a light source rich in ultraviolet rays such as a metal halide lamp or a high pressure mercury lamp, and then treated with a developer to leave the photosensitive layer unexposed. A lithographic printing plate is prepared by removing the portion and finally applying a gum liquid. Preferred examples of the developer are benzyl alcohol, 2-phenoxyethanol,
It is an alkaline aqueous solution containing a small amount of an organic solvent such as 2-butoxyethanol, and is described, for example, in U.S. Pat.
Examples include those described in No. 3475171 and No. 3615480. Furthermore, JP-A-1987-
The developers described in Japanese Patent Publication No. 26601, Japanese Patent Publication No. 56-39464, and Japanese Patent Publication No. 56-42860 are also excellent as developers for photosensitive printing plates using the photosensitive composition of the present invention. [Example] Hereinafter, a more detailed explanation will be given based on an example.
Note that % indicates weight %. Example 1 A substrate was prepared by the method disclosed in Japanese Patent Application Laid-Open No. 56-28893. That is, the surface of an aluminum plate having a thickness of 0.30 mm was grained using a nylon brush and a 400 mesh water suspension of pumice stone, and then thoroughly washed with water. in 10% sodium hydroxide
After etching by dipping at 70°C for 60 seconds, washing with running water, neutralizing with 20% HNO ₃ and washing with water. this
Electrolytic surface roughening treatment was carried out in a 1% nitric acid aqueous solution with an electrical charge of 160 coulombs/dm ² under the condition of V _A =12.7 V using a sinusoidal alternating current waveform. When the surface roughness was measured, it was 0.6μ (Ra display). Subsequently, it was immersed in a 30% H ₂ SO ₄ aqueous solution and desmatted at 55°C for 2 minutes, and then the thickness was 2.7 g/dm at a current density of 2 A/dm ² in a 20% H ₂ SO ₄ aqueous solution.
It was anodized for ^{2 minutes so that the thickness was 2} m2. after that
Immerse it in a 2.5% sodium silicate aqueous solution at 70℃ for 1 minute.
Washed with water and dried. The following photosensitive solution (1) was prepared. Photosensitive liquid (1) The following unsaturated polyurethane resin () 5g

[Formula] 0.2g PF ₆ salt of condensate of P-diazodiphenylamine and formaldehyde 0.2g F-177 (manufactured by Dainippon Ink Co., Ltd.: fluorine-based nonionic surfactant) 0.002g Methyl ethyl ketone 30g Ethylene glycol monomethyl Ether 10g Propylene glycol monomethyl ether 55g Ion-exchanged water 5g This photosensitive solution was coated onto the substrate using a spin coater so that the weight after drying was 2.0g/m ² . Drying was carried out at 100°C for 2 minutes. A negative film was adhered to this photosensitive plate and exposed for 20 counts using a Nuark printer (2KW metal halide lamp). After exposure, the plate was developed with the following developer at 25°C for 1 minute to obtain a printing plate. During development, no insoluble substances were generated in the developer. Developer: Benzyl alcohol 4.5g 38% aqueous solution of isopropylnaphthalenesulfonic acid sodium salt 4.5g Triethanolamine 1.5g Monoethanolamine 0.1g Sodium sulfite 0.3g Pure water 100g This printing plate was printed using a Heidel SOR printing machine. We were able to print 250,000 copies. By post-exposing the developer printing plate to light, the printing durability was further increased and it was possible to print up to 400,000 sheets. Synthesis method of unsaturated polyurethane resin (): 27.4 g of diethyl p-phenylene diacrylate
(0.1 mol), 40.8 g (0.2 mol) of 1,4-di-β-hydroxyethoxycyclohexanone, 300 mg of dibutyltin oxide (catalyst), and 30 mg of phenothiazine (inhibitor) in a stirring device, nitrogen gas inlet tube, thermometer, and distillation. Pour into a reactor equipped with a tube,
The reaction was started by heating to 190° C. while stirring under a nitrogen gas atmosphere. Thereafter, heating and stirring were continued for 4 hours to completely distill off the ethanol produced by the reaction to obtain a polyester prepolymer having hydroxyl groups at both ends. After cooling to 70° C., 300 g of dioxane (solvent) was added to dissolve the polyester prepolymer. Add 13.4 g (0.1 mol) of dimethylolpropionic acid and 4,4'-
50 g (0.2 mol) of diphenylmethane diisocyanate was added and reacted for 6 hours at the boiling point of the solvent.
After that, 200 g of dioxane was added and the polymer was precipitated by pouring it into water. The acid value of this polymer is
42, and the molecular weight was 24,000 according to GPC (gel permeation chromatography). Example 2 A printing plate was obtained in the same manner as in Example (1) except that the following unsaturated polyurethane resin () was used in place of the unsaturated polyurethane resin () of Example 1. During development, no insoluble substances were generated in the developer. When this printing plate was printed in the same manner as in Example 1, 200,000 sheets could be printed. Synthesis method of unsaturated polyurethane resin (): 32.9 g of diethyl p-phenylene diacrylate
(0.12 mol), 1,4-di-β-hydroxyethoxycyclohexanone 100 g (0.24 mol), dibutyltin oxide 350 mg and phenothiazine 35 mg
was charged into the reactor of Example 1, heated to 190°C while stirring under nitrogen gas atmosphere, and reacted for 4 hours.
Ethanol produced by the reaction was completely distilled off to obtain a polyester prepolymer having hydroxyl groups at both ends. After that, dioxane was cooled to 70℃.
360 g was added to dissolve the polyester prepolymer. Dimethylolpropionic acid 10.8 to this solution
g (0.08 mol) and 33.6 g (0.2 mol) of hexamethylene diisocyanate, and
Allowed time to react. After that, 200 g of dioxane was added, and the polymer was precipitated by pouring it into water. The acid value of this polymer is
37, and the molecular weight was 32,000 as determined by GPC. Example 3 A 0.5% aqueous solution of methyl methacrylate/ethyl acrylate/sodium 2-acrylamido-2-methylpropanesulfonate (50:30:20 molar ratio) copolymer was applied to the substrate of Example 1 using a roll coater. , 80°C for 1 minute. The coating weight after drying was 15 mg/m ² . The following photosensitive liquid was applied to this substrate. Unsaturated polymer of Example 1 of JP-A-60-191244 (diethyl p-phenylene diacrylate/ethylene oxide (6.2 mol) adduct of bisphenol A (1 mol)/pyromellitic dianhydride/4 , 4'-diphenylmethane diisocyanate) 5g

〔Effect of the invention〕

The photosensitive composition of the present invention is soluble in alkaline water, and a photosensitive material using the same can be easily developed in alkaline water, without generating insoluble substances in the developer during development. Furthermore, when crosslinked by exposure to light, it exhibits excellent adhesion to aluminum substrates. Therefore, printing plates made using this have extremely excellent printing durability.

Claims (1)

[Claims] 1 () An alkaline water-soluble compound having an acid value of 20 to 200 and having a photodimerizable unsaturated double bond adjacent to at least two aromatic nuclei in the main chain and at least one carboxyl group in the side chain. A photosensitive composition comprising a photosensitive polymer compound that can be dissolved or swelled, () a negative-acting diazo resin, and () an optional photosensitizer.