JPH0627659A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To provide a photosensitive compsn. having improved adhesive property to a substrate, high sensitivity and excellent printing resistance and developable with an aq. alkali developer. CONSTITUTION:This photosensitive compsn. contains a polymerizable compd. having two or more ethylenic unsatd. double bonds, a photopolymn. initiator and a photocrosslinkable polymer having maleimido groups.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive composition particularly suitable for a lithographic printing plate. More specifically, it improves the adhesiveness with the lithographic printing plate support, has high sensitivity and excellent printing durability,
Moreover, it relates to a photosensitive composition which can be developed with an aqueous alkaline developer.

[0002]

Photocrosslinkable materials which crosslink by a cycloaddition reaction are well known, and these are used as a main component of a photosensitive composition used for producing a photosensitive lithographic printing plate or the like, or for forming an image for a photoresist. Widely used as a material.

Although these photocrosslinkable polymers are highly sensitive and useful as photoresists,
Adhesion to the support is not good. If the adhesiveness is poor, the image may be peeled off or scratched due to brushing during development and sufficient printing durability cannot be obtained.This tendency is remarkable especially at low exposure, resulting in sensitivity. Will be lower.

A method of adding a negative-working diazo resin to the photosensitive layer in order to improve the adhesiveness (JP-A-62-7854).
No. 4) is proposed. However, when the diazo resin is added to the photosensitive layer, the storage stability is deteriorated, especially the moisture resistance is weakened, and the portion affected by moisture is easily soiled. Further, since a developing solution containing a solvent is required for developing the photosensitive layer, it is not preferable from the viewpoint of preventing pollution during wastewater treatment. In addition, a novel sensitizer (Japanese Patent Application Laid-Open No. 2-131236) is used to increase the adhesiveness to the support and shorten the exposure time.
JP-A-2-157762 and JP-A-2-17364
No. 6, JP-A-2-236552) has been proposed, but it has not reached the point where the above problem is solved.

[0005]

DISCLOSURE OF THE INVENTION The present invention uses a polymerizable compound having an ethylenically unsaturated double bond, a photopolymerization initiator, and a photocrosslinkable polymer having a maleimide group in combination. The inventors have found that the above problems can be solved and arrived at the present invention. Therefore, an object of the present invention is to provide a photosensitive composition which has improved adhesiveness to a support, high sensitivity and excellent printing durability, and which can be developed with an aqueous alkaline developer.

[0006]

The present invention contains a polymerizable compound having two or more ethylenically unsaturated double bonds, a photopolymerization initiator, and a photocrosslinkable polymer having a maleimide group. A photosensitive composition characterized by the above is provided.

Examples of the polymerizable compound having two or more ethylenically unsaturated double bonds (hereinafter referred to as the polymerizable compound of the present invention) include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate. , Diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, butylene glycol dimethacrylate, hexanediol diacrylate,
Hexanediol dimethacrylate, neopentyldiol diacrylate, neopentyldiol dimethacrylate, polypropylene glycol diacrylate, methoxydiethylene glycol methacrylate, methoxytetraethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, penta Examples thereof include erythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, and dipentaerythritol hexaacrylate.

The content of the polymerizable compound of the present invention is preferably 5 to 60% by weight, more preferably 10 to 50% by weight, based on all the components of the photosensitive composition of the present invention.

The photopolymerization initiator used in the present invention includes:
Conventionally used compounds can be appropriately used, examples of which include bis (p-aminophenyl-unsaturated) ketone, triphenylphosphine, organic phosphorus compounds such as quaternary phosphonium salts, and mercapto derivatives. , Tetrazonium derivatives, imidazoles, carbonyl compounds, peroxides, halogenated compounds, sensitizing dyes and the like.

The above bis (p-aminophenyl-unsaturated)
Examples of the ketone include 2,6-bis (4'-dimethylaminobenzylidene) cyclohexanone, 2,5-bis (4'-dimethylaminobenzylidene) cyclopentanone, and 2,5-bis (4'-diethylaminobenzylidene). Cyclopentanone, 2,6-bis (4'-diethylamino-2'-methylbenzylidene) cyclohexane,
2,5-bis (4'-diethylamino-2'-methylbenzylidene) cyclopentanone, 2,5-bis (4'-
Dimethylaminocinnamylidene) cyclopentanone and the like.

Examples of the above organic phosphorus compounds include triphenylphosphine, allyltriphenylphosphonium bromide, allyltriphenylphosphonium chloride, n-amyltriphenylphosphonium chloride and benzyltriphenylphosphonium chloride. , Bromomethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide and the like. Examples of the mercapto derivative include 2-mercaptobenzimidazole and 2-mercaptobenzimidazole.
Examples thereof include mercaptobenzothiazole and 2-mercaptobenzoxazole.

Examples of the above tetrazonium derivative include:
2,3-diphenyl-5- (p-diphenyl) tetrazolium chloride, 2,5-diphenyl-3- (p-diphenyl) tetrazolium chloride, 2,3-diphenyl-5-ethyltetrazolium chloride, 2,3-
Diphenyl-5- (m-hydroxyphenyl) tetrazolium chloride, 2,3-diphenyl-5- (p-methoxyphenyl) tetrazolium chloride, 2,3-
Diphenyl-5-methoxytetrazolium chloride,
2,5-diphenyl-3- (4-nitro-1-naphthyl) tetrazolium chloride, 2,5-diphenyl-
3- (p-phenylazophenyl) tetrazolium chloride, 2,5-diphenyl-3- (4-styrylphenyl) tetrazolium chloride, 2,3-diphenyltetrazolium perchloride, 2,3-diphenyl-
5-thienyl- (2) -tetrazolium chloride,
2,3-diphenyl-5- (p-tolyl) tetrazolium chloride, 2,5-diphenyl-3- (4-trimethylammoniumindole) phenyltetrazolium chloride, 2,3-di (p-tolyl) -5-phenyltetrazolium Chloride, 2,5-diphenyl (p-
Tolyl) -3-phenyltetrazolium chloride,
2,5-diphenyl-3- (p- (o-tolyl) azo-
o-tolyl) tetrazolium chloride, 2- (p-iodophenyl) -3- (p-nitrophenyl) -5-phenyl-2H-tetrazolium chloride and the like.

Examples of the above-mentioned imidazoles include 2-chlorophenyl-4,5-diphenylimidazole dimer,
2- (2,3-dichlorophenyl) -4,5-diphenylimidazole dimer and the like can be mentioned. Examples of the carbonyl compound include benzoin, benzoin isopropyl ether, benzyl dimethyl ketal, benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 1-hydroxycyclohexylphenyl ketone, Two
-Methyl- [4- (methylthio) phenyl] -2-morpholinote propane and the like.

Examples of the above-mentioned peroxide include di-t-butyl peroxide, benzoyl peroxide and 1,3-di (t
-Butyldioxycarbonyl) benzene, 3,3 ',
4,4'-tetrakis (t-butyloxycarbonyl)
Examples include benzophenone. Examples of the halogenated compound include 2,4,6-tri (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2-naphthyl-4,6. -Bis (trichloromethyl) -s-triazine and the like. Examples of the sensitizing dyes include xanthene dyes, merocyanine dyes, coumarin or ketocoumarin dyes.

The amount of the photopolymerization initiator added in the present invention is
It is preferably 0.1 to 5 with respect to the polymerizable compound of the present invention.
It is 0% by weight, more preferably 1 to 30% by weight.

The photocrosslinkable polymer having a maleimide group used in the present invention is described in, for example, JP-A-52-988 and Di.
16 of e Angewandte Mackrolekulare Chemie 115 (1983)
3-181. In the present invention, among these, the following general formula

[Chemical 1] (In the formula, R, R ₁ and R ₂ represent a hydrogen atom or a methyl group, and n represents an integer of 1 to 6) and a vinyl monomer having an alkali-soluble group in the molecule, such as 95 / 5 to 30/70 (molar ratio), preferably 90/10 to 70/30 (molar ratio).

Examples of the above copolymer include N- [2-
(Methacryloyloxy) ethyl] -2,3-dimethylmaleimide or N- [2- (methacryloyloxy)]
A copolymer of propyl] -2,3-dimethylmaleimide and acrylic acid and / or methacrylic acid is particularly preferred. The content of the above-mentioned maleimide group-containing copolymer is preferably 30 to 30 with respect to all components of the photosensitive composition of the present invention.
It is 95% by weight, more preferably 40 to 90% by weight.

In the present invention, a photosensitizer may be contained if necessary. Examples of the photosensitizer include thioxane and thioxanthone derivatives such as 2-chlorothioxanthone, dimethylthioxanthone, and diethylthioxanthone. The content of the photosensitizer is preferably 0.5 to 20% by weight, more preferably 2 to 15% by weight, based on all the components of the photosensitive composition of the present invention.
Is.

The photosensitive composition of the present invention may optionally contain a binder resin. Preferred binder resins include resins that are soluble or swellable in a weak alkaline aqueous solution that allow development in a weak alkaline aqueous solution. As these binder resins, acrylic acid copolymers, methacrylic acid copolymers, itaconic acid copolymers, crotonic acid copolymers, copolymers of alkyl methacrylate and acrylonitrile, acrylic acid, methacrylic acid, styrene, etc. Coalesce, copolymer of 2-hydroxyethyl methacrylate with acrylonitrile, methyl methacrylate, etc., copolymer of 2-hydroxypropyl methacrylate with acrylonitrile, methyl methacrylate,
Polyvinylpyrrolidone, ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer and partial esterified products thereof, polyhydroxystyrene, p-isopropenylphenol copolymer, phenol or cresol resin, p-hydroxymaleimide copolymer And so on. The content of these binder resins is preferably 50% by weight or less based on all components of the photosensitive composition of the present invention.

In the present invention, in addition to the above, a thermal polymerization inhibitor, a colorant (for example, a dye or a pigment), a plasticizer, a surfactant and the like may be used in combination, if necessary. As a result, a desired lithographic printing plate, photoresist, etc. can be prepared. The thermal polymerization inhibitor is added in a small amount in order to prevent unnecessary thermal polymerization during production or storage of the photosensitive composition of the present invention. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, pyrogallol, t-butylcatechol, di-t-butyl-p-cresol and the like. The addition amount of these thermal polymerization inhibitors is 0 to 5% by weight based on all components of the photosensitive composition of the present invention,
It is more preferably 0.1 to 3% by weight.

The above-mentioned dye or pigment is added for the purpose of coloring the photosensitive composition of the present invention. Specifically, crystal violet, malachide green,
Victoria Blue, Methylene Blue, Methyl Violet, Ethyl Violet, Rhodamine B, Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.), Oil Blue # 613 (Orient Chemical Co., Ltd.), Permanent Blue # 47 (Daido Chemical Co., Ltd.) (Made by the company). The content of these dyes or pigments is preferably 0.1 to 5.0% by weight, more preferably 0.5 to 4.0% by weight, based on all the components of the photosensitive composition of the present invention. is there.

A photo-acid generator may be added together with the above dye so as to obtain a visible image immediately after exposure. As a photo-acid generator, 1,2-naphthoquinone-2
-Diazide-4-sulfonyl chloride, 2,4,6-
Tri (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine , 2- (p-methoxynaphthyl) -4,6-bis (trichloromethyl)
Examples thereof include -s-triazine and 9,10-dimethoxyanthracene-2-sulfonic acid iodonium salt. The content thereof is preferably 0.05 to 1.5% by weight, more preferably 0.1 to 1.0% by weight.

Solvents used when applying the photosensitive composition of the present invention include methanol, ethanol, propanol, acetone, methylene chloride, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, NN-dimethylformamide, dimethyl sulfoxide, ethylene glycol. Examples thereof include monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and methyl lactate, and these can be used alone or in combination.

When the photosensitive composition of the present invention is used as a photosensitive layer of a photosensitive lithographic printing plate, the support thereof is paper,
A plastic film, a metal plate such as copper, zinc, aluminum, or stainless steel, or a composite material in which two or more kinds of these are combined can be used. Among these, particularly aluminum plates that have been brush- or ball-polished, aluminum plates that have been brush-polished and then anodized, aluminum plates that have been electrolytically-polished and then anodized, or aluminum plates that have been subjected to a combination of these. Is preferred.

The aluminum plate which has been subjected to such a pretreatment is further subjected to a chemical conversion treatment with a single solution or a mixed solution of alkali silicate, sodium phosphate, sodium fluoride, zirconium fluoride, alkyl titanate, trihydroxybenzoic acid and the like. , Boehmite treatment or coating treatment with an aqueous solution of strontium acetate, zinc acetate, magnesium acetate, calcium benzoate, polyvinylpyrrolidone, polyaminesulfonic acid, polyvinylsulfonic acid,
A coating treatment with polyacrylic acid, polymethacrylic acid, poly-2-hydroxyethyl acrylate or the like can be performed as a post-treatment.

On the photosensitive layer formed of the photosensitive composition of the present invention, a peelable transparent cover sheet is provided on the photosensitive layer in order to accelerate the photosensitive speed or prevent deterioration of storage stability. A coating layer made of a polymer having low oxygen permeability and removable at the time of development, such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, water-soluble nylon, or a cellulose compound, may be provided. In addition, a mat layer may be provided on the photosensitive layer for the purpose of improving vacuum adhesion to the film.

As a light source for irradiating the photosensitive composition of the present invention with an actinic ray, a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a carbon arc lamp, an argon laser, a helium / cadmium laser, an excimer laser or the like is used. be able to.

The developer for the photosensitive composition of the present invention includes sodium hydroxide, potassium hydroxide, sodium silicate, sodium metasilicate, sodium orthosilicate, sodium triphosphate, dibasic sodium phosphate and octanoic acid. Examples thereof include aqueous solutions of alkaline compounds such as sodium salts, monoethanolamine, diethanolamine, triethanolamine, and tetramethylammonium hydroxide. In the above alkaline aqueous solution,
An activator can be added if necessary. As the activator, an anionic surfactant or an amphoteric surfactant can be used.

[0029]

[Working] With the photosensitive composition obtained by the method of the present invention, the adhesiveness to a support is improved, high sensitivity and sufficient printing durability can be obtained, and storage stability, especially humidity resistance is impaired. Since it does not exist, it does not easily get dirty even if it gets wet. Further, the photosensitive composition according to the present invention can be developed with an aqueous alkaline developer.

[0030]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto.

Examples 1, 2 and 3: Comparative Example Example 1 An aluminum plate (material 1050) having a thickness of 0.24 mm and a width of 1000 mm was alkali degreased, and then a nylon brush was applied while applying a water suspension of silica stone powder. The surface was polished and then thoroughly washed with water. Then, a caustic soda solution of 20% by weight at 70 ° C. is flowed over for 5 seconds to etch the surface with 3 g / m ² and then rinsed with running water to remove hydrochloric acid (35 g /
l), boric acid (20 g / l) and aluminum ions (20 g / l) in an electrolytic solution at 25 ° C., 30 A / dm
^{It was} electropolished at a current density of ² for 30 seconds and washed with water. next,
1. The surface is etched by pouring caustic soda solution of 20% by weight at 70 ° C, followed by washing with water, and then anodizing treatment in a 10% by weight sulfuric acid aqueous solution at 30 ° C.
An oxide film of 0 g / m ² was formed. Then 5% by weight
It was immersed in a mixed solution of monosodium phosphate and 0.2% by weight sodium fluoride at 70 ° C. for 15 seconds, washed with water, and dried.

On the aluminum plate thus obtained, a photosensitive composition (photosensitive liquid 1) having the following composition was applied so that the coating film weight after drying would be 1.0 g / m ² and dried. ,
A photosensitive printing plate 1 was produced. Photosensitive solution 1 pentaerythritol tetraacrylate 5 g Photopolymerization initiator; N, N'-bis (diethylamino) benzophenone 0.15 g Ketocoumarin 0.15 g 2,4,6-Tris (trichloromethyl) -S-triazine 0.15 g N- [2- (methacryloyloxy) ethyl] -2,3-dimethylmaleimide / methacrylic acid = 80/20 (molar ratio) copolymer 6 g photosensitizer; 2,4-diethylthioxanthone 1 g crystal violet 0.15 g propylene glycol Monomethyl ether 70g Ethylene glycol monomethyl ether 70g

Example 2 An aluminum support was prepared in the same manner as in Example 1, and a photosensitive solution 2 having the following composition was applied so that the coating film weight after drying would be 1.0 g / m ² , dried, and exposed. Stable printing plate 2 was produced. Photosensitive solution 2 Pentaerythritol triacrylate 4 g Photopolymerization initiator; 2,5-bis (4'-diethylaminobenzylidene) cyclopentanone 0.15 g 2-mercaptobenzothiazole 0.15 g 2-chlorophenyl-4,5-diphenylimidazole 2 Polymer 0.15 g N- [2- (methacryloyloxy) ethyl] -2,3-dimethylmaleimide / methacrylic acid = 80/20 (molar ratio) copolymer 6 g Photosensitizer; 2,4-diethylthioxanthone 1 g Oil Blue # 613 (Orient Chemical Co., Ltd.) 0.20 g Propylene glycol monomethyl ether 70 g Ethylene glycol monomethyl ether 70 g

Example 3 Polyvinyl chloride was formed on the photosensitive layer of the photosensitive printing plate 2 prepared in Example 2.
Nyl alcohol (GL-05 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
Dry coating weight of 3% aqueous solution of F) is 1.0 g / m ²Tona
And then dried to produce a photosensitive printing plate 3.

Comparative Example As a comparative example, an aluminum support prepared in the same manner as in Example 1 was coated with a photosensitive solution 3 having the following composition so that the coating film weight after drying was 1.0 g / m ² . It was dried to produce a photosensitive printing plate 4. Photosensitive liquid 3 N- [2- (methacryloyloxy) ethyl] -2,3-dimethylmaleimide / methacrylic acid = 80/20 (molar ratio) copolymer 6 g Photosensitizer; 2,4-diethylthioxanthone 1 g Crystal violet 0.15g Propylene glycol monomethyl ether 60g Ethylene glycol monomethyl ether 60g

The photosensitive lithographic printing plate thus obtained was coated with a negative film and a step tablet No. manufactured by Kodak Co. No. 2 was vacuum-contacted, ultraviolet rays were irradiated at a distance of 1 m for 20 seconds using a 2 KW high-pressure mercury lamp, and the plate was immersed in a developer having the following composition at 25 ° C. for 30 seconds for development to obtain a lithographic printing plate sample. Developer composition JIS No. 3 sodium silicate 20 g potassium hydroxide 12 g Amogen K (Daiichi Kogyo Seiyaku Co., Ltd.) 0.8 g water 1 kg

Subsequently, the following test was conducted. (1) Sensitivity Read the number of solid steps on the step tablet. (2) Rubbing test (adhesion test) After development, the image area is scratched, and the image is peeled and scratched. (3) Printing durability test Each printing plate is placed on an offset printing machine, and the number of sheets from which good printed matter is obtained is examined. The results are shown in Table 1.

[0038]

[Table 1]

As is clear from the results shown in Table 1, the lithographic printing plates obtained in Examples 1, 2 and 3 are more sensitive, adhesive and printing durable than the printing plates obtained in Comparative Example. Excellent version in any case.

[0040]

INDUSTRIAL APPLICABILITY The photosensitive composition of the present invention has high sensitivity and can be developed with an aqueous alkali solution, and when used as a printing plate, it gives a lithographic printing plate having excellent adhesiveness and high printing durability. it can.

Claims (2)

[Claims] 1. A photosensitive composition comprising a polymerizable compound having two or more ethylenically unsaturated double bonds, a photopolymerization initiator, and a photocrosslinkable polymer having a maleimide group. . 2. A polymerizable compound having an ethylenically unsaturated double bond is contained in an amount of 5 to 60% by weight based on all components of the photosensitive composition, and a photopolymerization initiator is added to the polymerizable compound in an amount of 0.
A photosensitive composition comprising 1 to 50% by weight and a photocrosslinkable polymer having a maleimide group in an amount of 30 to 95% by weight based on all components of the photosensitive composition.