JPH0667417A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To enhance adhesiveness to a support by incorporating a polymer having maleimide groups, a compound having an ethylenically unsaturated double bond, diazo resin salts, a photosensitizer, photopolymerization initiator, and a diazo sensitizer. CONSTITUTION:This photosensitive composition comprises 100 pts.wt. of the photocross-linkable polymer having the maleimide groups, 0.1-200 pts.wt. of the polymerizable polymer having the >=2 ethylenidally unsaturated double bonds and the diazo resin salts, further, the photosensitizer, photopolymerization initiator, and the diazo stabilizer. The adhesiveness to the support is not enhanced so much by adding only the compound having >=2 double bonds, but the adhesiveness are more enhanced and sensitivity time is quickened by adding the diazo resin salts in a small amount so as not to impair the storage stability of the photosensitive layer. It is preferred to use 4,4'-bis(dialkylamino)- benzophenonein to both roles of the photopolymerization initiator and the diazo stabilizer.

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 relates to a photosensitive composition having improved adhesion to a lithographic printing support, high sensitivity, excellent printing durability, and developable 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. These photo-crosslinkable polymers have high sensitivity and are useful as photoresists, but their adhesion to a support is not good. If the adhesiveness is poor, the image may be peeled off or scratched during development due to brushing, etc., and sufficient printing durability cannot be obtained. Will be lower.

A method of adding a negative-working diazo resin to a photosensitive layer in order to improve adhesion (Japanese Patent Laid-Open No. 62-78544).
No.) 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. Also,
The development of the photosensitive layer requires a developing solution containing a solvent, which is not preferable from the viewpoint of pollution problems in treating wastewater.

Further, a novel sensitizer (Japanese Patent Laid-Open No. 2-1312) is used to increase the adhesiveness to the support and shorten the sensitivity time.
36, JP-A-2-157762, and JP-A-2-173.
No. 646 and Japanese Patent Laid-Open No. 2-236552) have been proposed, but they have not reached the point where the above problems are solved.

[0005]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to improve the adhesiveness to a support, have high sensitivity and excellent printing durability, and have no problem in storage stability, and develop with an aqueous alkaline developer. It is to provide a possible photosensitive composition.

[0006]

The present invention relates to a diazo resin salt and a polymerizable compound having two or more ethylenically unsaturated double bonds per 100 parts by weight of a photocrosslinkable polymer having a maleimide group. 0.1 to 200 parts by weight, and further containing a photosensitizer, a photopolymerization initiator, and a diazo stabilizer, and a photosensitive composition, and the photopolymerization initiator and diazo stabilizer. The present invention provides a photosensitive composition characterized by using 4,4'-bis (dialkylamino) benzophenone represented by the following general formula (I) as an agent.

[Chemical 2] In the formula, R represents an alkyl group having 1 to 2 carbon atoms.

In the present invention, when only the polymerizable compound having two or more ethylenically unsaturated double bonds is added, the adhesiveness to the support is not improved so much. If a small amount of diazo resin salt is added to this so that the storability of the photosensitive layer is not impaired, the adhesiveness with the support is further improved and the sensitivity time can be shortened. Further, generally, in the photosensitive composition, the photopolymerization initiator and the diazo stabilizer are inherently impurities, and it is better to add as little amount as possible, which is economically good. The present inventors have found that a benzophenone derivative represented by the above general formula (I) is
They have found that they are effective as a photopolymerization initiator and also as a diazo stabilizer, and decided to incorporate them in the photosensitive composition for the purpose of serving as both functions.

The present invention will be described in detail below. The photocrosslinkable polymer having a maleimide group used in the present invention is
For example, JP-A-52-988, Die Angewan
dte Macklelekulare Chemie
115 (1983) 163-181 is used.

In the present invention, among these, the following general formula

[Chemical 3] (Wherein R ₁ , R ₂ and R ₃ 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, it is copolymerized at a ratio of 90/10 to 70/30 (molar ratio).

Examples of the above copolymer include N- [2-
(Methacryloyloxy) ethyl] -2,3-dimethylmaleimide or N- [2- (methacryloyloxy)]
Particularly preferred is a copolymer of propyl] -2,3-dimethylmaleimide and acrylic acid and / or methacrylic acid. The content of the copolymer having a maleimide group is 30 to 95% by weight based on the total components of the photosensitive composition of the present invention.
Is preferred.

The polymerizable compound having two or more ethylenically unsaturated double bonds (hereinafter referred to as a polymerizable compound) used in the present invention is, for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethide. Methacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, butylene glycol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, neopentyldiol diacrylate, neopentyldiol dimethacrylate Methacrylate,
Polypropylene glycol diacrylate, methoxydiethylene glycol methacrylate, methoxytetraethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate Methacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate and the like can be mentioned.

Suitable diazo resin salts used in the present invention are those which are insoluble in water and soluble in aqueous alkali solutions and organic solvents. As such a diazo resin salt, a diazo monomer having a 4-diazodiphenylamine skeleton, a 4-diazodiphenylether skeleton or a 4-diazodiphenylsulfide skeleton,
Examples thereof include a cocondensation product of an aldehyde or an aldehyde having a carboxyl group and a divalent aromatic compound which can be condensed with the aldehydes in some cases.

Specific examples of the diazo monomer include 4-
Diazodiphenylamine, 4'-hydroxy-4-diazodiphenylamine, 4'-methoxy-4-diazodiphenylamine, 4'-ethoxy-4-diazodiphenylamine, 4'-methyl-4-diazodiphenylamine,
4'-ethyl-4-diazodiphenylamine, 4-diazo-3-methoxydiphenylamine, 3-methyl-4-
Diazodiphenylamine, 3-ethyl-4-diazodiphenylamine, 3'-methyl-4-diazodiphenylamine, 3-ethoxy-4-diazodiphenylamine, 4
-Diazodiphenyl ether, 4'-methoxy-4-diazodiphenyl ether, 4'-carboxy-4-diazodiphenyl ether, 4-diazodiphenyl sulfide, 4'methyl-4-diazodiphenyl sulfide and the like.

Specific examples of the aldehyde or the aldehyde having a carboxyl group include formaldehyde,
Acetaldehyde, propionaldehyde, butyraldehyde, glyoxylic acid, etc. can be mentioned. Instead of the above aldehyde, 4,4'-dimethoxymethyldiphenyl ether can be used for condensation.

Specific examples of the aromatic compound include phenol, o, m, p-cresol, xylenol, resorcin, o, m, p-methoxyphenol, catechol, p-hydroxyethylphenol, naphthol, pyrogallol, hydroquinone, Bisphenol A, bisphenol S, o, m, p-chlorophenol, cumylphenol, benzoic acid, salicylic acid, 4-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 4-methoxybenzoic acid, 4-phenoxybenzoic acid, Cinnamic acid, 4-hydroxycinnamic acid, methyl 4-hydroxycinnamate, 4-
Ethyl hydroxycinnamate, 4-nitrocinnamic acid, 4-
Methoxycinnamic acid, cinnamylidene acetic acid, 4-hydroxycinnamylidene acetic acid, cyanocinnamylidene acetic acid,
2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone and the like can be mentioned. Among these, particularly preferably used are 4-
Hydroxybenzoic acid, cinnamic acid, cinnamylidene acetic acid,
Cyanocinnamylidene acetic acid.

The diazo resin is most preferably used in the form of an organic salt or an inorganic salt. Examples of the organic compound which reacts with the diazo resin to form an organic salt include compounds described in JP-B-40-2203, JP-B-41-6813 and JP-B-47-1167. For example,
Benzenesulfonic acid, p-toluenesulfonic acid, 2,5
-Xylene sulfonic acid, linear or side chain dodecylbenzene sulfonic acid (commonly known as dodecyl benzene sulfonic acid), 2-methoxy-4-hydroxy-5-benzoylbenzene sulfonic acid, methanyl yellow, 2-chlorotoluene-4-sulfonic acid, Examples thereof include alkali metal salts, alkaline earth metal salts and ammonium salts thereof.

Further, as an example of the inorganic compound which reacts with the above-mentioned diazo resin to form an inorganic salt, Japanese Patent Publication No. 40-220.
3, JP-A-54-98613, and US Pat. No. 40934.
There are compounds described in No. 65 and the like. For example, borofluoric acid, hexafluorophosphoric acid, phosphotungstic acid,
Examples thereof include thiocyanic acid, alkali metal salts and ammonium salts thereof.

The above polymerizable compound and diazo resin salt are preferably added in an amount of 0.1 to 200 parts by weight based on 100 parts by weight of the photocrosslinkable polymer having a maleimide group.
If the amount is less than 0.1 parts by weight, photocuring will be poor and the adhesion to the support will be poor. When the amount is 200 parts by weight or more, the storage stability is deteriorated, and when it is used for a printing plate, it easily becomes dirty. The ratio of the polymerizable compound and the diazo resin salt is 1: 0.001 to
1: 4 (weight ratio) is preferable. Diazo resin salt is 0.00
When it is 1 or less, the adhesion to the support is poor, and when 4 or more,
Storability deteriorates and stains easily occur when used for printing plates.

Examples of the photosensitizer used in the present invention 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 based on the total weight of all components of the photosensitive composition of the present invention.

As the photopolymerization initiator used in the present invention, conventionally known ones can be preferably used, and examples thereof include benzophenone derivatives (carbonyl compounds) and bis (p-aminophenyl-unsaturated). Examples thereof include organic phosphorus compounds such as ketones, triphenylphosphine or quaternary phosphonium salts, mercapto derivatives, tetrazonium derivatives, imidazoles, peroxides, halogenated compounds and sensitizing dyes.

Among these, particularly, a benzophenone derivative (carbonyl compound) represented by the above general formula (I),
For example, when 4,4'-bis (dimethylamino) benzophenone and 4,4'-bis (diethylamino) benzophenone are contained, the sensitivity is improved and it is effective.

The amount of the photopolymerization initiator added in the present invention is
0.1 to 5 on the basis of the polymerizable compound of the present invention
0% by weight is preferred.

As the diazo stabilizer used in the present invention, conventionally known phosphoric acid, oxalic acid, citric acid, malic acid, tartaric acid, mandelic acid, benzophenone derivative and the like can be used. 4,4'-bis (dimethylamino) benzophenone represented by I) or 4,4'-bis (diethylamino) benzophenone is preferred. The amount of the diazo stabilizer added is preferably 5 to 90% by weight based on the diazo resin salt.

In the present invention, in addition to the above components, a binder resin, a thermal polymerization inhibitor, a colorant (for example, dye or pigment), a plasticizer, a surfactant, etc. may be used in combination, if necessary. By using these in combination, a desired lithographic printing plate, photoresist or the like can be prepared.

Examples of the binder resin include resins which are soluble or swellable in a weak alkaline aqueous solution and which enable 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- Examples thereof include maleic anhydride copolymers and partial esterified products thereof, polyhydroxystyrene, p-isopropenylphenol copolymers, phenol or cresol-formaldehyde resins, and p-hydroxymaleimide copolymers. That.

The content of these binder resins is 50% by weight, based on the total components of the photosensitive composition of the present invention.
The following are preferred.

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 amount of these thermal polymerization inhibitors added is preferably 0 to 5% by weight based on the total weight of all components of the photosensitive composition of the present invention.

The above dyes or pigments are 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 based on the total weight of all components of the photosensitive composition of the present invention.

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 is preferably 0.05 to 5% 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, which 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.

Of these, 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 a combination of these. Aluminum plates are preferred.

The pretreated aluminum plate is further subjected to chemical conversion treatment with an alkali silicate, sodium phosphate, sodium fluoride, zirconium fluoride, alkyl titanate, trihydroxybenzoic acid or the like alone or as a mixture. , Boehmite treatment or coating treatment with an aqueous solution of strontium acetate, zinc acetate, magnesium acetate, calcium benzoate, polyvinylpyrrolidone, polyaminesulfonic acid, polyvinylphosphonic acid, polyacrylic acid, polymethacrylic acid, poly-2-hydroxyethyl acrylate, etc. It is also possible to carry out the coating treatment by means of a post treatment.

On the photosensitive layer formed by the photosensitive composition of the present invention, a peelable transparent cover sheet is provided on the photosensitive layer in order to accelerate the sensitivity time or prevent deterioration of storage stability. Alternatively, it is possible to provide a coating layer of a polymer having a low oxygen permeability and removable during development, such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, water-soluble nylon, or a cellulose compound. 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.

As a developing solution for the photosensitive composition of the present invention, sodium hydroxide, potassium hydroxide, sodium silicate, sodium metasilicate, sodium orthosilicate, sodium triphosphate, dibasic sodium phosphate, octanoic acid is used. Examples thereof include aqueous solutions of alkaline compounds such as sodium salts, monoethanolamine, diethanolamine, triethanolamine, and tetramethylammonium hydroxide.

If necessary, an activator can be added to the above alkaline aqueous solution. As the activator, an anionic surfactant or an amphoteric surfactant can be used.

[0038]

[Working] With the photosensitive composition obtained by the present invention,
Adhesiveness to the support is improved, high sensitivity and excellent printing durability can be obtained, and storage stability, especially moisture resistance is not deteriorated, so that it is difficult to stain even if it is humid. Further, the photosensitive composition according to the present invention can use an aqueous alkaline developing solution during development.

[0039]

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

Examples 1 to 3 and 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 the surface thereof was brushed with a nylon brush while applying a water suspension of silica stone powder. 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,
The surface is etched by pouring a 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 2.0 g / m ² was formed. Then, it is immersed in a 5 wt% sodium silicate solution at 70 ° C. for 15 seconds,
It was washed with water and dried.

The aluminum plate thus obtained was coated with a photosensitive composition (photosensitive liquid 1) having the following composition so that the coating film weight after drying was 1.0 g / m ² , and dried. ,
A photosensitive printing plate 1 was produced. Photosensitive liquid 1: N- [2- (methacryloyloxy) ethyl] -2,3-dimethylmaleimide / methacrylic acid = 80/20 (molar ratio) copolymer 6 g pentaerythritol tetraacrylate 2.5 g 4-diazodiphenylamine and 4 -Hydroxybenzoic acid and formaldehyde co-condensate 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate 0.1 g 2,4-diethylthioxanthone 0.8 g 4,4'-bis (dimethylamino) benzophenone 0 0.08 g 2-chlorophenyl-4,5-diphenylimidazole dimer 0.08 g Victoria Pure Blue BOH 0.15 g ethylene glycol monomethyl ether 70 g propylene glycol monomethyl ether 70 g N-N-dimethylformamide 10 g

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 liquid 2: N- [2- (methacryloyloxy) ethyl] -2,3-dimethylmaleimide / methacrylic acid = 80/20 (molar ratio) copolymer 6 g pentaerythritol triacrylate 2 g 4-diazodiphenylamine and cinnamylidene acetic acid Hexafluorophosphate of co-condensation of formaldehyde 0.15 g 2,4-diethylthioxanthone 0.8 g 4,4'-bis (dimethylamino) benzophenone 0.08 g 2-chlorophenyl-4,5-diphenylimidazole dimer Body 0.08 g Crystal violet 0.15 g Propylene glycol monomethyl ether 70 g Ethylene glycol monomethyl ether 70 g N-N-dimethylformamide 10 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 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 2,4-diethylthioxanthone 0.8 g Crystal violet 0. 15g Propylene glycol monomethyl ether 60g Ethylene glycol monomethyl ether 60g

A negative film and a step tablet No2 manufactured by Kodak Co. were vacuum-contacted to each of the photosensitive lithographic printing plates thus obtained, and ultraviolet rays were irradiated for 20 seconds at a distance of 1 m using a 2 KW high pressure mercury lamp, A lithographic printing plate sample was obtained by immersing in a developer having the following composition at 25 ° C. for 30 seconds for development. 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.

[Table 1]

[0047]

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

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Claims (2)

[Claims] 1. A polymerizable compound having two or more ethylenically unsaturated double bonds and 0.1 to 100 parts by weight of a diazo resin salt with respect to 100 parts by weight of a photocrosslinkable polymer having a maleimide group. In addition to 200 parts by weight, a photosensitive composition containing a photosensitizer, a photopolymerization initiator, and a diazo stabilizer. (2) 4,4'-bis (dialkylamino) benzophenone represented by the following general formula (I) is used as the photopolymerization initiator and the diazo stabilizer. ) The photosensitive composition described in In the formula, R represents an alkyl group having 1 to 2 carbon atoms.