JP3167429B2 - Photosensitive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photosensitive composition particularly suitable for a lithographic printing plate. More specifically, the adhesiveness with the lithographic printing plate support has been improved, with high sensitivity and excellent printing durability,
In addition, the present invention relates to a photosensitive composition developable with an aqueous alkaline developer.

[0002]

2. Description of the Related Art Photocrosslinkable materials which are crosslinked by a cycloaddition reaction are well known, and they 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.

[0003] Although these photocrosslinkable polymers are highly sensitive and useful as photoresists,
Adhesion with 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 may not be obtained. Becomes lower.

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

[0005]

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

[0006]

The present invention comprises a polymerizable compound having two or more ethylenically unsaturated double bonds, a photopolymerization initiator, and a photocrosslinkable polymer having a maleimide group. And a photosensitive composition characterized by the following.

The polymerizable compound having two or more ethylenically unsaturated double bonds (hereinafter referred to as the polymerizable compound of the present invention) includes, for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate. , Diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 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 Erythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate and the like.

[0008] The content of the polymerizable compound of the present invention is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight, based on all components of the photosensitive composition of the present invention.

The photopolymerization initiator used in the present invention includes:
Conventionally used ones can be used as appropriate, examples of which include bis (p-aminophenyl-unsaturated) ketones, organic phosphorus compounds such as triphenylphosphine or 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 ketones 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, benzyltriphenylphosphonium chloride. , Bromomethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide and the like. Examples of the mercapto derivative include 2-mercaptobenzimidazole and 2-mercaptobenzimidazole.
Mercaptobenzothiazole, 2-mercaptobenzoxazole and the like can be mentioned.

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-trimethylammonium indole) 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 imidazoles include 2-chlorophenyl-4,5-diphenylimidazole dimer,
2- (2,3-dichlorophenyl) -4,5-diphenylimidazole dimer and the like. Examples of the carbonyl compound include benzoin, benzoin isopropyl ether, benzyldimethyl ketal, benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 1-hydroxycyclohexylphenyl ketone, 2
-Methyl- [4- (methylthio) phenyl] -2-morpholinatopropane and the like.

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

In the present invention, the amount of the photopolymerization initiator added is
Preferably 0.1 to 5 with respect to the polymerizable compound of the present invention.
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
e Angewandte Mackrolekulare Chemie 115 (1983) 16
3-181. In the present invention, among these, the following general formula

Embedded image (Wherein 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, for example, 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)
[Propyl] -2,3-dimethylmaleimide and a copolymer of acrylic acid and / or methacrylic acid are particularly preferred. The content of the copolymer having a maleimide group is preferably from 30 to 30% based on 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 can be contained as required. Examples of the photosensitizer include thioxane, 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 components of the photosensitive composition of the present invention.
It is.

The photosensitive composition of the present invention can contain a binder resin if necessary. Preferred binder resins include resins that are soluble or swellable in a weakly alkaline aqueous solution and that enable development of a weakly alkaline aqueous solution. These binder resins include acrylic acid copolymers, methacrylic acid copolymers, itaconic acid copolymers, crotonic acid copolymers, copolymers of alkyl methacrylate with acrylonitrile, acrylic acid, methacrylic acid, styrene and the like. A copolymer of 2-hydroxyethyl methacrylate and acrylonitrile, a copolymer of methyl methacrylate and the like, a copolymer of 2-hydroxypropyl methacrylate and acrylonitrile, a copolymer of methyl methacrylate,
Polyvinyl pyrrolidone, ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer and its partial ester, polyhydroxystyrene, p-isopropenylphenol copolymer, phenol or cresol resin, p-hydroxymaleimide copolymer And the like. 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 (eg, a dye or pigment), a plasticizer, a surfactant, and the like may be used in combination, if necessary. This makes it possible to prepare a desired lithographic printing plate, photoresist or the like. The thermal polymerization inhibitor is added in a small amount 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.
More preferably, it is 0.1 to 3% by weight.

The above 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 (manufactured by Hodogaya Chemical Industry Co., Ltd.), Oil Blue # 613 (manufactured by Orient Chemical Industry Co., Ltd.), Permanent Blue # 47 (Daido Chemical Industry Co., Ltd.) Manufactured by a 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 components of the photosensitive composition of the present invention. is there.

In order to obtain a visible image immediately after exposure, a photoacid generator can be added together with the above dye. As the photoacid generator, 1,2-naphthoquinone-2
-Diazido-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)
-S-triazine, 9,10-dimethoxyanthracene-2-sulfonic acid iodonium salt and the like. The content 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, N-N-dimethylformamide, dimethyl sulfoxide, ethylene glycol Monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate and the like can be mentioned, 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 may be paper,
A plastic film, a metal plate of copper, zinc, aluminum, stainless steel, or the like, or a composite material of a combination of two or more thereof can be used. Among these, particularly, an aluminum plate polished with a brush or a ball, an aluminum plate polished with a brush and then subjected to anodization, an aluminum plate subjected to anodization after being polished electrolytically, or an aluminum plate treated with a combination thereof Is preferred.

The aluminum plate subjected to such a pretreatment is further subjected to a chemical conversion treatment using a single solution or a mixed solution of alkali silicate, sodium phosphate, sodium fluoride, zirconium fluoride, alkyl titanate, trihydroxybenzoic acid, or the like. , Boehmite treatment or coating treatment with an aqueous solution such as strontium acetate, zinc acetate, magnesium acetate, calcium benzoate, polyvinyl pyrrolidone, polyamine sulfonic acid, polyvinyl sulfonic acid,
Coating treatment with polyacrylic acid, polymethacrylic acid, poly-2-hydroxyethyl acrylate, or the like can also be performed as a post-treatment.

On the photosensitive layer formed by the photosensitive composition of the present invention, a transparent cover sheet that can be peeled off from the photosensitive layer is used in order to increase the photosensitive speed or prevent deterioration of storage stability. It is also possible to provide a coating layer of a polymer having a low oxygen permeability and being removable at the time of development, such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, water-soluble nylon, and a cellulose compound. Further, a mat layer may be provided on the photosensitive layer for the purpose of improving the vacuum adhesion to the film.

As a light source for irradiating the photosensitive composition of the present invention with actinic rays, 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.

Examples of the developer for the photosensitive composition of the present invention include sodium hydroxide, potassium hydroxide, sodium silicate, sodium metasilicate, sodium orthosilicate, tribasic sodium phosphate, dibasic sodium phosphate and octanoic acid. An aqueous solution of an alkaline compound such as sodium salt, monoethanolamine, diethanolamine, triethanolamine, and tetramethylammonium hydroxide can be used. In the above alkaline aqueous solution,
Activators can be added as needed. As the surfactant, an anionic surfactant or an amphoteric surfactant can be used.

[0029]

The photosensitive composition obtained by the method of the present invention improves the adhesion to a support, provides high sensitivity and sufficient printing durability, and also impairs the storage stability, especially the moisture resistance. Because there is no, it is hard to get dirty even if it gets wet. The photosensitive composition according to the present invention can be developed with an aqueous alkaline developer.

[0030]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Examples 1, 2, and 3: Comparative Examples Example 1 An aluminum plate (material 1050) having a thickness of 0.24 mm and a width of 1000 mm was degreased with an alkali, and then sprinkled with an aqueous suspension of silica powder using a nylon brush. The surface was polished and then washed well with water. Next, a 20% by weight caustic soda solution was poured at 70 ° C. for 5 seconds, the surface was etched at 3 g / m ² , then washed with running water, and hydrochloric acid (35 g / m ^2).
l), boric acid (20 g / l) and aluminum ion (20 g / l) in an electrolyte at 25 ° C. and 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 a 20% by weight caustic soda solution at 70 ° C., followed by washing with water, and then anodizing in a 10% by weight sulfuric acid aqueous solution at 30 ° C.
An oxide film of 0 g / m ² was formed. Next, 5% by weight
It was immersed in a mixed solution of monosodium phosphate and 0.2% by weight of sodium fluoride at 70 ° C. for 15 seconds, washed with water, and dried.

The thus obtained photosensitive composition (photosensitive solution 1) was applied onto the aluminum plate so as to obtain a coating film weight of 1.0 g / m ² after drying, and dried. ,
A photosensitive printing plate 1 was manufactured. 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 weight after drying was 1.0 g / m ² , dried, and dried. 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 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 (manufactured by Orient Chemical Industry Co., Ltd.) 0.20 g Propylene glycol monomethyl ether 70 g Ethylene glycol monomethyl ether 70 g

Example 3 The photosensitive printing plate 2 produced in Example 2
Nyl alcohol (GL-05 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
A 3% aqueous solution of F) has a dry coating weight of 1.0 g / m ^TwoTona
And dried to produce a photosensitive printing plate 3.

Comparative Example As a comparative example, a photosensitive solution 3 having the following composition was applied to an aluminum support prepared in the same manner as in Example 1 so that the coating weight after drying was 1.0 g / m ² . It dried and the photosensitive printing plate 4 was manufactured. Photosensitive solution 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 0.15 g Propylene glycol monomethyl ether 60 g Ethylene glycol monomethyl ether 60 g

To the photosensitive lithographic printing plate thus obtained, a negative film and Step Tablet No. 2 was vacuum-adhered, irradiated with ultraviolet rays at a distance of 1 m for 20 seconds using a 2 KW high-pressure mercury lamp, immersed in a developer having the following composition at 25 ° C. for 30 seconds, and developed to obtain a planographic 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 performed. (1) Sensitivity Read the solid number of steps on the step tablet. (2) Rubbing test (adhesion test) After development, the image portion is inspected for damage, image peeling, and damage. (3) Printing durability test Each printing plate is set on an offset printing press to check the number of sheets on which a good printed matter is obtained. Table 1 shows the results.

[0038]

[Table 1]

As is evident from the results shown in Table 1, the planographic printing plates obtained in Examples 1, 2 and 3 have higher sensitivity, adhesive strength and printing durability than the printing plates obtained in Comparative Examples. Both are excellent versions.

[0040]

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, gives a planographic printing plate having excellent adhesion and high printing durability. it can.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03F 7/038 G03F 7/027 G03F 7/028

Claims (2)

(57) [Claims] 1. A ethylenically unsaturated double bond polymerizable compound having two or more photopolymerization initiators, and the following general
A monomer represented by the formula and an alkali-soluble group in the molecule
A photosensitive composition comprising a photo-crosslinkable polymer having a maleimide group copolymerized with a vinyl monomer having the same. Embedded image (Wherein R, R ₁ and R ₂ represent a hydrogen atom or a methyl group
And n represents an integer of 1 to 6. ) 2. A polymerizable compound having an ethylenically unsaturated double bond in an amount of 5 to 60% by weight based on the total weight of the photosensitive composition, and a photopolymerization initiator in an amount of 0.
A photosensitive composition comprising 1 to 50% by weight, and 30 to 95% by weight of a photocrosslinkable polymer having a maleimide group based on all components of the photosensitive composition.