JPH0369097B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photosensitive composition for a reducible lithium film. More specifically, it can be used as a lithographic film used in photolithography, etc., and when the halftone dots of the reproduced image are made smaller after image duplication and the power is reduced, even if the power is reduced after the date and time after the duplication, the speed of reduction is low. The present invention relates to a photosensitive composition that can be used for lithographic films that do not change their reducing properties. Silver halide photosensitive materials are currently used as lithographic film for contact return in the photolithography process, but due to the depletion of silver resources, there is a need to replace this with non-silver salt photosensitive materials. There is a lot of movement. However, the essential function for this substitution is the ability to modify the tone of the image by making the halftone dots of the reproduced image smaller (reduction, dot etch), and non-silver salt photosensitive materials that have this function are few. A known non-silver salt photosensitive material having such a force reducing property is disclosed in Japanese Patent Application Laid-Open No. 52-62427, which reduces force by utilizing the fact that the formed image has an uncured lower layer. things are listed. This certainly has excellent force reduction properties (force reduction % and force reduction speed) immediately after image formation. However, when this material comes into close contact with the proof plate and is exposed to light from the back side during proof plate printing, which is a common process in the photolithography process,
Naturally, the uncured lower layer hardens, and it becomes impossible to reduce the force at the time when it is actually required. In order to improve this drawback, the present inventors invented a method of containing a polymerization inhibitor in the image area of the formed image, and previously filed a patent application. Through this invention, a non-silver salt lithium-ion film was realized that had a force-reducing property that could be used in the actual photolithography process. It turns out that there is. In the actual photoengraving industry, the proof is shown to the customer and the reproduced image is reduced in strength according to the customer's request. may be six months later. Therefore, unless the force reduction property remains the same throughout this period, it cannot be realistic. However,
Even with the method of the invention described above, the force reduction property itself decreases as the product is left unused, and it eventually becomes impossible to reduce force. This phenomenon occurs regardless of the presence or absence of the above-mentioned back exposure and the presence or absence of a polymerization inhibitor, so the cause is not due to a photoreaction. This is a huge problem. The present inventors have worked diligently to solve these problems and to develop a photosensitive material for image duplicating materials that can truly reduce force, and as a result, they have gradually completed the present invention. That is, the present invention provides at least (1)
Actinic ray absorber, (2) polymeric binder having one or more carboxylic acid groups, sulfonic acid groups, or phosphoric acid groups in the molecule, (3) the following general formula

[Formula] or

[Formula] (In the formula, R ₁ and R ₂ are alkyl groups having 1 to 3 carbon atoms, R ₃
represents an alkyl group having 1 to 6 carbon atoms, and R ₄ and R ₅ represent an alkyl group having 3 to 6 carbon atoms. Contains (4) a photoinitiator and (5) a polymerizable monomer. ,
Absorbance within the active light range is 0.4~ per 1μ thickness
This is a photosensitive composition for lithographic film that can be subjected to stress reduction treatment, and is characterized in that it has a viscosity of 4.0. Each composition of the photosensitive composition of the present invention will be explained in detail below. (1) Actinic ray absorber In addition to the photoinitiator described below, a compound effective in absorbing rays in the wavelength range to which the photosensitive composition of the present invention is sensitive, that is, actinic rays, can be added to form a lithographic film. In this case, an image that is opaque to imagewise actinic radiation is formed. By increasing the absorption of actinic rays, in the image area exposed through the transparent part of the mask, only the upper layer undergoes a curing reaction, while the lower layer remains uncured. In this manner, by retaining the uncured lower layer portion, the force reducing property, which is an advantageous characteristic for use as a plate-making film, is maintained. The active light absorbers used include ultraviolet absorbers, ultraviolet absorbing dyes, and other dyes and pigments, and the ingredients and blending amounts are determined so that the absorbance within the active light range is 0.4 to 4.0 per 1 μm of thickness. You can choose as appropriate. Examples of these include powders of compounds such as carbon black, titanium oxide, iron oxide, various metals and metal oxides, and sulfides, pigment black (CI50440), chrome yellow light (CI77603), 2,2'-dihydroxy-
4-methoxybenzophenone, 2,4-dihydroxybezophenone, hydroxyphenylbenzotriazole, 2-(2'-hydroxy-5'-
methoxyphenyl) benzotriazole, resorcinol monobenzoate, ethyl-2-cyano-3,3-diphenyl acrylate, toluidine yellow GW (CI71680), molybdenum orange (CI77605), Sudan yellow (C.
I.30), oil orange (CI12055), etc. In particular, carbon black is desirable in order to achieve the same black color as conventional silver salts. Furthermore, when using a non-colored ultraviolet absorber, it is better to add dyes or pigments because the image area is difficult to see. In the case of inorganic/organic pigments, metals, and metal compounds, it is necessary to make them into fine particles by physical or chemical methods. (2) Polymeric binder The polymeric binder useful in the present invention is an organic polymer that is soluble in a solvent and is fixed at temperatures below 50°C, and that has a carboxylic acid group or a sulfonic acid group in its molecule. It is a polymer having one or more groups such as a group or a phosphate group. The amount of such acid groups is preferably in the range of 1 to 4 equivalents per kg of polymer, and by using such a polymer, the resulting image duplicating material can be denatured or weakened in an alkaline aqueous solution. Examples of such polymers include: (a) Polymers containing carboxylic acid groups Methyl methacrylate-methacrylic acid copolymer, methyl methacrylate-butyl methacrylate-acrylic acid copolymer, methyl acrylate-acrylic acid Acid copolymer, vinyl acetate-methacrylic acid copolymer, vinylidene chloride-itaconic acid copolymer, styrene-aleic acid copolymer, styrene-maleic acid monobutyl ester copolymer, acrylonitrile-vinyl acetic acid copolymer and Copolymerization of vinyl compounds containing carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, vinyl acetic acid, and maleic acid with other vinyl compounds, cellulose acetate phthalate, hydroxypropyl methyl cellulose phthalate, hydroxypropyl methyl cellulose acetate succinate, etc. cellulose derivatives, etc. (b) Polymers containing sulfonic acid groups Vinyl acetate-ethylene sulfonic acid copolymer, methyl methacrylate-allylsulfonic acid copolymer, methyl methacrylate-styrene sulfonic acid, methyl methacrylate-2-sulfoethyl acrylate copolymer Polymer, methyl acrylate-2-sulfoethyl methacrylate copolymer, styrene-2-acrylamide-2
-Methylpropanesulfonic acid copolymer, etc. (c) Polymers containing phosphoric acid groups Examples include methyl methacrylate-2-hydroxyethyl acryloyl phosphate copolymer and methyl methacrylate-2-hydroxyethyl methacryloyl phosphate copolymer. (3) Amine compounds In order to achieve the purpose of the present invention of preventing changes over time in photographic performance such as alkaline developability, sensitivity, and resolving power of the composition, and in reducing power, the amine compounds that are effective in the present invention are particularly those listed below. It is necessary to limit it to amine compounds represented by the general formula.

[expression] or

[Byron 20S (saturated polyester adhesive manufactured by Toyobo Co., Ltd.) 50 parts Coronate L (manufactured by Nippon Polyurethane Industries) 4 parts U-Cat SA-No.102 (manufactured by Sun Abbott) 0.1 part Toluene 80 parts Methyl ethyl ketone 20 parts]

Next, a photosensitive composition was prepared by mixing and dispersing the following compositions, and each of the photosensitive compositions was coated using a reverse coater onto a polyester film provided with the following undercoat layer to form a photosensitive layer having a thickness of 3 μm. [Polymeric binder (copolymer of methyl methacrylate and methacrylic acid) (molar ratio 77/23) 39 parts 2,2'-bis(2-chlorophenyl)-4,4',
5,5'-Tetraphenylbiimidazole 8 parts Michler's ketone 3 parts Trimethylolpropane triacrylate 31 parts 2-mercaptobenzothiazole 1 part Carbon black 18 parts Methanol 280 parts Ethyl acetate 80 parts Chloroform 40 parts Amine compound shown in Table 1 Equivalent molar amount to the carboxylic acid of the combined binder] Furthermore, a protective layer composition having the composition shown below was coated on this film in the same manner, and the thickness
A Lithfilm green plate with a 1 μm protective layer was prepared. [Polyvinyl alcohol (degree of saponification 98.5%, degree of polymerization 500) 5 parts Neugen EA-140 (manufactured by Daiichi Kogyo Seiyaku) 0.2 parts methanol 5 parts water 90 parts] A 21-step step guide (large (manufactured by Nippon Screen Co., Ltd.) and a test negative film that combines a 150/in, flat-tone image with a dot area ratio of 40%, and a 3KW light room printer (ORC).
Image exposure was performed for 15 seconds. Next, after removing the protective layer by washing with water, the sample is immersed in a 0.75% Na ₂ Co ₃ aqueous solution adjusted to 30°C for a predetermined time (white-out time), then washed with water, developed while rubbing with a sponge, and dried. A reversed image was obtained. It was found that up to the 5th stage of the step guide was cured, and the halftone dots reproduced the negative well. Next, a duplicate halftone image made in the same manner was immersed for 15 seconds in a 5% aqueous solution of hydroquinone kept at 30°C, washed with water, and dried. Regarding the sample thus obtained, as described below,
A force reduction test was conducted. (1) First, assuming printing of a proof plate, expose the sample to 80 mJ/cm ² from the back side using a bright room printer. Prepare two similarly treated samples of the same type. One of the sheets was used as a sample after 0 days of aging, and the force reduction operation described in (2) below was immediately applied. I looked at the changes over time. (2) A mixed aqueous solution of potassium phosphate and sodium ammonium hydrogen phosphate (1:1 by weight) was prepared as a reducing solution, and each sample was immersed in this solution for 30 seconds and then drained. It was rubbed with a sponge on a washing light table, washed with water, and dried. The % reduction (indicated by the difference between the halftone area ratio (%) before reduction and the halftone area ratio (%) after reduction) of the obtained sample was measured using a dot area meter (manufactured by Dainippon Screen).
Measure with DT-10). The results obtained are shown in Table 1 below.

【table】

[41.5 parts of polymeric binder shown in Table 2] 2,2'-bis(2-chloro-1-naphthyl)-4,4',5,5'-tetraphenylbiimidazole 8 parts Jimedon Part 3 7-diethylamino-4-methylcoumarin 1.5 parts Hydroquinone monomethyl ether 0.05 part 34 parts trimethylolpropane triacrylate Carbon black 12 parts Methanol 280 parts 80 parts of ethyl acetate Chloroform 40 parts Amine compounds shown in Table 2 Equivalent molar amount based on carboxylic acid of polymeric binder]

Furthermore, a protective layer was coated in the same manner as in Example 1, and the resulting lithium film was subjected to a stress reducing property test. However, the exposure amount was adjusted so that the step guide was cured in five steps. The obtained results are summarized in Table 2.

【table】

[Table] As is clear from Table 2, as long as the amine compound of the present invention is used, no matter which one of a carboxylic acid group, a sulfonic acid group, or a phosphoric acid group is contained in the molecule as a polymeric binder, It can be seen that the % reduction in force of the obtained lithium film is maintained.

Claims (1)

[Scope of Claims] 1 At least (1) an actinic ray absorber, (2) a polymeric binder having one or more of carboxylic acid groups, sulfonic acid groups, or phosphoric acid groups in the molecule; (3) the following: General formula [Formula] or [Formula] (In the formula, R ₁ and R ₂ are alkyl groups having 1 to 3 carbon atoms, R ₃
represents an alkyl group having 1 to 6 carbon atoms, R ₄ and R ₅ represent an alkyl group having 3 to 6 carbon atoms, (4) a photoinitiator, and (5) a polymerizable monomer. including,
Absorbance within the active light range is 0.4~ per 1μ thickness
4.0 A photosensitive composition for lithographic film which can be subjected to force reduction treatment.