JPH04216555A - Photosensitive planographic printing plate without requiring damping water - Google Patents

Abstract

PURPOSE:To make a dye liquid unnecessary by providing a coloring layer and a shielding layer on the coloring layer and removing the shielding layer in an unexposed area for developing so that the color layer appears only in the picture image area and that a visible picture image can be obtd. CONSTITUTION:A shielding layer is provided on a primer layer to prevent coloring of the primer layer. This shielding layer consists of white powder particles. The binder used in the shielding layer is such one soluble in water-base developer, and for example, polyamide and polyether can be used. The white particles has 0.01-10mum average particle size. The add amt. is decided depending on the film thickness and kinds of white particles, namely, pigment, metal powder, and polymer compd., and is preferably 5-75wt.%, and more preferably 30-50wt.%. The film thickness of the shielding layer is 0.01-10mum preferably, and more preferably, 0.1-10mum.

Description

Detailed Description of the Invention [0001] [Industrial Application Field] The present invention relates to a photosensitive lithographic printing plate that does not require dampening water, and more specifically, provides a clear image and is easy to maintain after development. To provide a photosensitive lithographic printing plate that does not require dampening water and does not require time for a dyeing process, does not stain hands or clothes with a dyeing solution, and does not stain an automatic developing machine during dyeing. BACKGROUND OF THE INVENTION Conventionally, photosensitive lithographic printing plates that do not require dampening water (hereinafter referred to as "plate material" as necessary) have been prepared by coating a photosensitive layer and an ink repellent layer on a support in this order. something is known. A printing plate can be obtained by exposing and developing this plate material. For such plate materials, it is necessary to examine the condition of the plate (developability, scratches, stains on the plate, etc.) during or after development, and therefore it must have excellent plate inspection properties. [0003] In order to improve this plate inspection property, conventionally, in Japanese Patent Application Laid-Open No. 63-280251, etc., a primer layer, a photosensitive layer, and an ink repellent layer are sequentially laminated on a substrate, and no dampening water is required. After imagewise exposing the photosensitive lithographic printing plate, the unexposed areas of the photosensitive layer are eluted or swollen using a developer, and then the unexposed areas of the photosensitive layer and the silicone rubber layer in contact with the photosensitive layer are removed. It has been shown that the primer layer is exposed and only this primer layer is dyed with a dyeing solution, but [
[0004] In this method, the dyeing process takes time;
In addition, the replenishment, storage, and management of the dye solution during the series of plate-making processes is complicated, and there are problems such as staining hands and clothes with the dye solution during dyeing, and staining the automatic processor with the dye solution. . Furthermore, there is a problem of pollution in the treatment of the dye solution after use. [0005] Therefore, the inventors of the present invention took into account the above-mentioned plate inspection properties and conducted various studies on methods that do not use staining solutions.
It was discovered that by removing the hiding layer in the unexposed area during development, a colored layer appears only in the image area and a visible image can be obtained, and this has led to the present invention. OBJECTS OF THE INVENTION Therefore, the object of the present invention is to obtain clear images and eliminate the need for a dyeing solution, so that the dyeing process does not take much time and does not stain hands or clothes with the dyeing solution. To provide a photosensitive lithographic printing plate that does not require dampening water and does not stain an automatic developing machine and therefore has a good working environment. [Structure of the Invention] The object of the present invention is to provide a photosensitive lithographic printing plate that does not require dampening water and is formed by sequentially laminating a primer layer, a photosensitive layer, and an ink repellent layer on a substrate, wherein the primer layer contains a colorant. This is achieved by using a photosensitive lithographic printing plate which does not require dampening water and which contains a masking layer between the photosensitive layer and the primer layer. The configuration of the present invention will be explained in more detail below. The present invention is characterized in that a coloring agent is added to the primer layer, a hiding layer is provided on the primer layer, and a visible image is obtained by removing this hiding layer by development. The primer layer used in the present invention includes, for example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin,
Examples include polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin, polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, and the like. Preferred examples include acrylic resin, polyester resin, and urethane resin. These resins are preferably used in the form of being cured by heat or light. Further, as the anchor agent constituting the primer layer, for example, the silane coupling agent, silicone primer, etc. described above can be used, and organic titanates and the like are also effective. [0010] In the present invention, a coloring agent is added to the primer layer, and the preferred coloring agents are the following dyes or pigments. Victoria Pure Blue BOH, Oil Blue #603, Oil Pink #312, Patent Pure Blue, Crystal Violet, Leuco Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Green, Erythrosin B, Basic Fuchsin, Malachite Green,
[0011] Leucomalachite green, m-cresol purple, cresol red, xylenol blue,
Triphenylmethane type, diphenylmethane type, oxazine type, xanthene type, iminonaphthoquinone type, azomethine type or anthraquinone type, represented by rhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, cyano-p-diethylaminophenylacetanilide, etc. pigment, Victoria Pure Blue (C
．． C.I 42595), Catione brilliantoflavin (C.I.
Basic 13), Rhodamine 6GCP (C.I.
45160), Erioglaucine X (C.I 420)
80), Fast Black HB (C.I 2615
0), Shimla Fast Red 4015 (C.I.
12355), Lionor Red 7B4401 (C.I.
15830), First Gen Blue TGR-L (
C. I 74160), Lionor Blue SM (C.
I 26150), Mitsubishi Carbon Black MA-10
0, 0013] Mitsubishi Carbon Black #30, #40
, #50, MA-100, Cyanine Blue 4920 (manufactured by Dainichiseika), and Seika Fast Carmine 1483 (manufactured by Dainichiseika). [0014] The content of the colorant in the primer layer used in the present invention is 5% to 75% by weight in the case of dye;
In the case of pigments, 5% to 90% by weight is suitable. The hiding layer used in the present invention is placed on the primer layer and blocks coloring of the primer layer, and white particles are used as the hiding material. The binder resin used in the concealing layer according to the present invention is soluble in an aqueous developer, and examples include those shown below. Examples of the binder resin include polyamide, polyether, polyester, polycarbonate, polystyrene, polyurethane, polyvinyl chloride and its copolymers, polyvinyl butyral resin, polyvinyl formal resin, shellac, epoxy resin, phenol resin, acrylic resin, and the like. Preferably, copolymers of the monomers shown in (1) to (12) below, usually having a weight average molecular weight of 1,000 to 200,000, are used. (1) Monomers having aromatic hydroxyl groups, such as N-(4
-hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, o-, m-, p
-Hydroxystyrene, o-, m-, p-hydroxyphenylacrylate or methacrylate, 0017
(2) Monomers having aliphatic hydroxyl groups, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate; (3) α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic anhydride; 4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate,
(Substituted) alkyl acrylates such as 2-chloroethyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, and N-dimethylethyl acrylate; (5) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate; Cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 4-
(Substituted) alkyl methacrylates such as hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate, etc. (6) Acrylamide, methacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-hexylmethacrylamide, N - Acrylamides or methacrylamides such as cyclohexyl methacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N-phenylacrylamide, etc. (7) Ethyl vinyl ether, 2-chloro Vinyl ethers such as ethyl vinyl ether, hydroxyethyl vinyl ether, provinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, (8) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate, etc. 9) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene,
(10) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (11) olefins such as ethylene, propylene, isobutylene, butadiene, and isobrene; (1)
2) N-vinylpyrrolidone, N-vinylcarbazole,
4-vinylpyridine, acrylonitrile, methacrylonitrile, etc. Furthermore, monomers that can be copolymerized with the above monomers may be copolymerized. It also includes, but is not limited to, copolymers obtained by copolymerizing the above-mentioned nomers and modified with, for example, glycyl methacrylate, glycyl acrylate, and the like. More specifically, a copolymer having a hydroxyl group containing the monomers listed in (1) and (2) above is preferred, and a copolymer having an aromatic hydroxyl group is even more preferred. The white particles contained in the concealing layer used in the present invention include white pigments such as alumina white, lead white, titanium dioxide, molybdenum white, and zinc oxide, as well as aluminum zinc, antimony, bismuth, calcium, indium, magnesium, and nickel. , white metal powder such as tin. [0026] As for the white particle size, the average particle size is 0.
01 to 10 μm is preferable, and the amount added can be determined depending on the thickness of the hiding layer and the type of white particles used in the hiding layer (pigment, metal powder, polymer compound), but it is 5% to 10% by weight. 75% is preferred, particularly 30%
~50% by weight. Further, the thickness of the concealing layer used in the present invention is preferably 0.01 to 10 μm, particularly preferably 0.1 to 5 μm. [0027] Furthermore, a coating property improver, a plasticizer, a fat-sensitizing agent, a stabilizer, etc. can be added to the above-mentioned hiding layer, if necessary. Examples of the coating property improver include alkyl ethers (eg, ethyl cellulose, methyl cellulose), fluorine-based surfactants, nonionic surfactants (eg, Bluronic L64 (manufactured by Asahi Denka)), and the like. Examples of the plasticizer for imparting flexibility and abrasion resistance to the coating film include butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate,
Dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrafurfuryl oleate,
Examples include oligomers of acrylic acid or methacrylic acid. The amount of these additives added varies depending on the intended purpose, but is generally 0.01% by weight based on the total solid content.
~30% by weight is preferred. The hiding layer used in the present invention is removed by development, and any known developer can be used as a developer for plate materials that do not require dampening water, but preferably an aqueous developer. is used. Water-based developer is 3 parts of water.
0% by weight or more, preferably 50% to 98% by weight,
Examples include developing solutions containing organic solvents and surfactants, and more preferably containing an alkaline agent. Examples of organic solvents contained in the developer containing water as a main component include aliphatic hydrocarbons (hexane, heptane, Isopar E, H, G (manufactured by Esso Chemical Co., Ltd., aliphatic hydrocarbon products). alcohols (methanol, ethanol, 1-butoxy-2-propanol, 3-methyl- 3-methoxybutanol, β-anilinoethanol, benzyl alcohol, etc.), 0031
Ethers (methyl cellosolve, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, methyl carbitol, ethyl carbitol, butyl carbitol, dioxane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol dibutyl ether, propylene glycol, dipropylene glycol) butyl ether, tripropylene glycol methyl ether, polypropylene glycol methyl ether, etc.)
, Ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, 4-
methyl-1,3-dioxolan-2-one, etc.), esters (ethyl acetate, propyl acetate, hexyl acetate, methyl acetate, propyl acetate, diethyl succinate, dibutyl oxalate, diethyl maleate, benzyl benzoate, methyl cellosolve acetate) , cellosolve acetate, carbitol acetate, etc.). [0033] As the surfactant added to the developer used in the present invention, anionic surfactants, nonionic surfactants, cationic surfactants and amphoteric ionic surfactants are used. The surfactants described in specification No. 206041 are used. These surfactants can be used alone or in combination of two or more. The appropriate amount of the surfactant used in the present invention is 0.01% to 60% by weight, preferably 0.1% to 10% by weight. Furthermore, the alkaline agents used in the present invention include (1) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, dibasic or tribasic sodium or ammonium phosphate, sodium metasilicate, Inorganic alkaline agents such as sodium carbonate and ammonia; (2) mono-, di- or trimethylamine;
mono- or diisopropylamine, n-butylamine,
Examples include organic amine compounds such as mono-, di- or triethanolamine, mono-, di- or triisopropanolamine, ethyleneimine, ethylenediimine. The amount of alkaline agent used is 0.05% to 20% by weight,
Preferably, 0.2% to 10% by weight is appropriate. Development can be carried out, for example, by rubbing with a developing pad containing a developer as described above, or by pouring the developer onto the printing plate and then rubbing with a developing brush. By the above development, a part of the photosensitive layer in the unexposed area and the silicone rubber are removed from the printing plate, or only the silicone rubber layer is removed, and the colored photosensitive layer is exposed, and the exposed area is substantially separated from the silicone rubber layer. A printing plate is obtained in which a photosensitive layer that does not develop color remains. The photosensitive layer that can be used in the present invention includes, in the case of a positive type, a photopolymerizable adhesive layer, a photocrosslinkable photosensitive layer, a photosensitive layer made of a diazo resin, a binder resin, and the like. In the case of a negative type, a photosensitive layer made of a quinone diazide compound and a binder resin, etc. can be used. Various conventionally known diazo resins can be used as the above-mentioned diazo resin, but include diazo resins represented by condensates of aromatic diazonium salts and, for example, active carbonyl-containing compounds, especially formaldehyde; Solvent-soluble diazo resins are preferred. Preferred specific examples of the diazo resin include resins represented by the following formula 1. [Formula 1] [In the formula, R12, R13, and R14 each represent a hydrogen atom, an alkyl group, or an alkoxy group, and preferably a hydrogen atom. R15 represents a hydrogen atom, an alkyl group or a phenyl group, preferably a hydrogen atom. X represents the counter anion of the diazo resin, specifically, P
It represents F6, BF4, organic carboxylic acids such as decanoic acid and benzoic acid, organic phosphoric acids such as phenylphosphoric acid, and sulfonic acids such as methanesulfonic acid. [0041] Y represents NH, S, or O. Furthermore, Z is a sulfonic acid group, a sulfonate (Na salt, K salt, etc.) group, a sulfinic acid group, a sulfinate (Na salt, K salt, etc.) group, an O
Represents a phenyl group or naphthyl group substituted with at least one substituent selected from H group and COOH group. The ratio of m and n is m/n=1/0 to 10 in molar ratio.
, preferably in the range of 1/0 to 2. ] [0042]
The diazo resin represented by the above formula 1 preferably has a molecular weight of about 500 to 10,000. The content of the diazo resin in the photosensitive layer is preferably selected from the range of 1 to 70% by weight, more preferably from 3 to 60% by weight. [0043] In the negative type photosensitive lithographic printing plate that does not require dampening water, an orthoquinone diazide compound is used, and as the compound, for example, a polycondensation resin of phenols and aldehydes or ketones and the following formula 2 or formula 3 are used. Orthoquinonediazide sulfonic acid ester or carboxylic acid ester obtained by chemically condensing orthoquinonediazide sulfonic acid or carboxylic acid derivative represented by: [Formula 2] [Formula 3] [In the formula, X is -SO2 Y or -COY
In the group represented by, Y represents a group that can be removed during condensation of a halogen atom, an alkali metal, etc. ] Specific examples of the compound represented by the above formula 2 include 1,2-benzoquinonediazide (2)-4-sulfonyl chloride, 1,2-benzoquinonediazide (2)-4-carbonyl chloride, and 1,2-benzoquinonediazide (2)-4-carbonyl chloride.
Examples include benzoquinone diazide (2)-, 5-sulfonyl chloride, 1,2-benzoquinone diazide (2)-5-carbonyl chloride, and the like. Specific examples of the compound represented by the above formula 3 include 1,2-naphthoquinonediazide (2)-4-sulfonyl chloride, 1,2-naphthoquinonediazide (2)
-4-carbonyl chloride, 1,2-naphthoquinonediazide (2)-5-sulfonyl chloride, 1,2-naphthoquinonediazide (2)-5-carbonyl chloride, and the like. Polycondensation resins of phenols and aldehydes or ketones include, for example, Japanese Patent Publication No. 43-28
403, a polycondensate of pyrogallol and acetone; as described in JP-A-55-76346, a polycondensate of a mixture of pyrogallol and resorcin and acetone; JP-A-45-9610; As stated in the publication, phenol, formaldehyde,
Novolac resin or meta-cresol formaldehyde novolac resin; As described in Japanese Patent Publication No. 50-5083, para-substituted phenol formalin resin (e.g. para-cresol formalin resin, para-t-butylphenol formalin resin, Paraethylphenol formalin resin, parapropylphenol formalin resin, paraisopropylphenol formalin resin, para n-butylphenol formalin resin, paraoctylphenol formalin resin, etc.), [0050] described in Japanese Patent Publication No. 62-60407 Polycondensation of formaldehyde with a phenol mixture containing a phenol substituted with an alkyl group or phenyl group having 3 to 12 carbon atoms and phenol or its methyl substituted product or a mixture thereof in a molar ratio of 1:9 to 9:1. (eg, polycondensates of the para-substituted phenol and phenol, para-cresol, metacresol, etc.). The esterification rate of the orthoquinone diazide group to the hydroxyl group of the polycondensation resin of phenols and aldehydes or ketones is preferably 15 to 100 mol%, more preferably 20 to 80 mol%. Furthermore, as an orthoquinone diazide compound,
Orthonaphthoquinonediazide sulfonic acid ester of polyhydroxybenzophenone (e.g. 1,2-naphthoquinonediazide(2)-5-sulfonic ester, 1,2-
naphthoquinone diazide (2)-4-sulfonic acid ester, etc.). This polyoxybenzophenone is a compound obtained by replacing two or more hydrogen atoms of benzophenone with hydroxyl groups, such as dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone, octahydroxybenzophenone, or derivatives thereof. , (for example, a substituent for a halogen atom, an alkyl group, an aryl group, an aralkyl group, a carboxylic acid group), and the like. Preferred are trihydroxybenzophenone and tetrahydroxybenzophenone, more preferred are 2,3,4-trihydroxybenzophenone and 2,3,4,4'-tetrahydroxybenzophenone. Moreover, the esterification rate with respect to hydroxyl groups is preferably 30 to 100%. In the present invention, each of the above compounds may be used alone as the orthoquinone diazide compound, or two or more thereof may be used in combination. Among these orthoquinonediazide compounds listed above, 1,2-naphthoquinonediazide (2)-5-sulfonic acid ester of 2,3,4-trihydroxybenzophenone or 1,2-naphthoquinonediazide (2) )-4-sulfonic acid ester, 1,2-naphthoquinone diazide (2)-5-sulfonic acid ester of metacresol formaldehyde novolak resin or 1,
2-naphthoquinonediazide (2)-4-sulfonic acid ester or a mixture thereof is more preferably used. The proportion of the orthoquinonediazide compound in the photosensitive layer is preferably 50 to 60% by weight, more preferably 20 to 50% by weight. Further, examples of binder resins used in the photosensitive layer include acrylic resins and novolak resins. All copolymerizable monomers can be used as the copolymerizable constituents of the acrylic resin, and in particular, the following compounds having unsaturated bonds are used as monomers for radical polymerization. (1) Monomers having a hydroxyl group: (2)
-Hydoxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, 4-hydroxyphenyl (
meth)acrylate, 2-hydroxyphenyl(meth)
(Meth)acrylate monomers such as acrylate; N
-(meth)acrylamide monomers such as methylol(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-(hydroxyphenyl)-(meth)acrylamide, N-(hydroxynaphthyl)-(meth)acrylamide; o- , m-, p-hydroxystyrene monomers, etc. (2), (meth)acrylic acid ester or amide monomers other than (1); methyl (meth)acrylate, ethyl (meth)acrylate, propyl ( Alkyl (meth)acrylates such as meth)acrylate and butyl (meth)acrylate; N-phenyl (meth)acrylamide, o-, m-, p-methoxyphenyl (meth)acrylamide, o-, m-, p-ethoxy Phenyl (meth)acrylamide etc. (3) Monomers having a cyano group in the side chain; (meth)acrylonitrile, 2-pentenitrile, 2
-Methyl-3-butenenitrile, 2-cyanoethyl acrylate, o-, m-, p-cyanostyrene, etc.; (4)
Monomers having carboxylic acid in the side chain; (meth)acrylic acid, itaconic acid and its anhydride, maleic acid and its anhydride, crotonic acid, etc.; (5) Vinyl ethers; propyl vinyl ether, butyl vinyl ether, Octyl vinyl ether, phenyl vinyl ether, etc., (6) Styrenes; α-methylstyrene, methylstyrene, chloromethylstyrene, styrene, etc.; (7) Vinyl ketones; Methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, etc. (
8) Monomers other than (1) to (7); Examples include olefins such as ethylene, propylene, isobutylene, butadiene, and vinyl chloride, N-vinylpyrrolidone, N-vinylcarbazole, and 4-vinylpyridine, but others Any monomer can be used as long as it can undergo radical copolymerization with these monomers. In the present invention, in addition to the above-mentioned materials, the photosensitive layer may further contain dyes, pigments, coatability improvers, plasticizers,
A fat sensitizer, a stabilizer, etc. can be added. It is advantageous that the photosensitive layer of the positive type photosensitive lithographic printing plate that does not require dampening water further contains a known exposure-visible image imparting agent. Examples of the above dyes include Victoria Pure Blue BOH, Oil Blue #603, Oil Pink #312, Patent Pure Blue, Crystal Violet, Leuco Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Green, Erythrosine B, and Basic Fuchsin. , Malachi Green,
Leucomalachite green, m-cresol purple,
Cresol red, xylenol blue, rhodamine B
, auramine, 4-p-diethylaminophenylimino naphthoquinone, cyano-p-diethylaminophenyl acetanilide, etc.; triphenylmethane, diphenylthane, oxazine, xanthene, iminonaphthoquinone, azomethine, or anthraquinone pigments; can be mentioned. The dye is usually contained in the photosensitive layer in an amount of about 0.01 to about 1
0% by weight, preferably about 0.05-8% by weight. Examples of the coating property improver include alkyl ethers (eg, ethyl cellulose, methyl cellulose), fluorine-based surfactants, nonionic surfactants (eg, Bluronic L64 (manufactured by Asahi Denka)), and the like. Examples of plasticizers for imparting flexibility and abrasion resistance to the coating film include butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate,
Dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrafurfuryl oleate,
Examples include oligomers of acrylic acid or methacrylic acid. [0065] The amount of these additives added varies depending on the intended purpose, but is generally 0.01% of the total solid content.
% to 30% by weight is preferred. The thickness of the photosensitive layer used in the present invention is usually 0.05 to 100 μm, preferably,
It is 0.1 to 20 μm. In the present invention, a silicone rubber layer is coated on the photosensitive layer. The silicone rubber used in the present invention is preferably a cotton-like or somewhat crosslinked polyorganosiloxane. The polyorganosiloxane usually has a molecular weight of 1,000 to several hundred thousand, and is suitably crosslinked in the form of a liquid, wax, or cake at room temperature. The polyorganosiloxane is classified into condensed type and addition type depending on the method of crosslinking. [0067] In the condensed type, crosslinking is performed by a condensation reaction, and water, alcohol, organic acid, etc. are released by the reaction. Particularly useful condensation silicone rubbers include:
Examples include mixtures of linear polyorganosiloxanes having hydroxyl groups, acetoxy groups, etc. at both ends or part of the main chain, and silicone crosslinking agents, or those in which hydroxyl groups are reacted with silicone crosslinking agents, and in both cases, a condensation catalyst is added. This is more advantageous in terms of crosslinking speed. Particularly preferred are those obtained by condensation crosslinking of linear dimethylorganopolysiloxanes having hydroxyl groups at both ends. The main chain of the polyorganosiloxane has the following repeating units. [Formula 4] In the formula, R1 and R2 are each an alkyl group, an aryl group, an alkenyl group, which may have a substituent, or a combination thereof, and include a methyl group, a phenyl group, a vinyl group, and a tri-substituted group. A fluoropropyl group is preferred, and a methyl group is particularly preferred. As the silicone crosslinking agent, -OCO
CH3, -ONR(R'), -ON=CR(R'),
-OR, -NR(R') or -OH (where R and R'
is an alkyl group. ) Condensation type silicone crosslinking agents such as so-called deacetic acid type, deoxime type, dealcoholized type, deaminated type, dehydrated type, and the like, which have a functional group represented by the following formulas, can be mentioned. Examples of such crosslinking agents include tetraacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, phenyltriacetoxysilane, dimethyldiacetoxysilane, diethylacetoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane. , dimethyldimethoxysilane, vinyltrimethoxysilane, methyltris(acetoneoxime)silane, methyltris(N-methyl-N-acetylamino)silane, vinyltris(methylethylketoxime)silane,
Examples include methyltri(methylethylketoxime)silane and oligomers thereof. The amount of each of these crosslinking agents is preferably in the range of 0.5 to 30 parts by weight per 100 parts by weight of the polyorganosiloxane. Examples of the condensation catalyst include organic carboxylic acids, titanate esters, acetylacetone metal complexes, chloroplatinic acid, naphthenic acid, and the like. The addition type refers to one in which a water-based group in a crosslinking agent is added to an unsaturated group in the main body, such as a vinyl group (-CH=CH2), resulting in crosslinking. Specifically, examples include vinyl group-containing organopolysiloxanes, hydrogenated organopolysiloxanes, and the like mixed with platinum-based catalysts (for example, chloroplatinic acid). The polyorganosiloxane has repeating units similar to those of the condensed type described above in the main chain. For the silicone rubber layer used in the present invention, either or both of condensation type and addition type silicone rubbers can be used. It is also possible to use condensed and addition type polyorganosiloxanes having hydroxyl groups, unsaturated groups, etc. in one polyorganosiloxane. The thickness of the silicone rubber layer used in the present invention is usually 0.5 μm to 10 μm, preferably 1 μm.
It is μm to 5 μm. In the present invention, an adhesive layer made of acrylic resin or the like may be provided between the photosensitive layer and the silicone rubber layer, and the adhesive layer may contain various reactive crosslinking agents,
It can contain a silane coupling agent and the like, and the thickness of the adhesive layer is preferably 0.01 μm to 0.5 μm. [0077] As the substrate used in the present invention, any substrate can be used as long as it has the flexibility to be set in a normal lithographic printing machine and can withstand the load applied during printing, including the layer structure. There are no particular restrictions. For example, paper such as coated paper, aluminum plate (JIS standard H
Examples include metal plates such as (-16, H-18, etc.), and plastic films such as polyethylene terephthalate. [0078] In particular, an aluminum plate or a composite material of aluminum foil and other materials is preferable, and an aluminum plate is particularly preferable from the viewpoint of printing durability. In addition, from the viewpoint of storage stability, the substrate, particularly an aluminum plate, or a composite material of aluminum foil and other materials, can be surface-treated by a known method before use. Such surface treatments include, for example, a method of treating the surface of an aluminum plate with a silicate (US Pat. No. 2,714,066), a method of treating the surface of an aluminum plate with an organic acid salt (US Pat. No. 2,714, No. 066), a method of treatment with phosphonic acids and their derivatives (U.S. Pat. No. 3,220,
No. 832), treatment with potassium hexafluorozirconate (U.S. Pat. No. 2,946,683), anodic oxidation, and treatment with an aqueous solution of alkali metal silicate after anodization (U.S. Pat. No. 3, 181,461) etc. The thickness of such a support is 50 μm to 4 μm.
00 μm is preferable, more preferably 100 μm to 30 μm.
It is 0 μm. In the present invention, a protective layer may be provided on the upper surface of the silicone rubber layer, if necessary. As the material for this protective layer, it is preferable to use a water-soluble film such as polyvinyl alcohol, a biodegradable film such as polyhydroxyalkanoate, or polyesteramide. The plate material of the present invention that does not require dampening water can be produced, for example, as follows. A composition solution to form a primer layer is applied onto a support using a conventional coater such as a reverse roll coater, an air knife coater, a Meyer bar coater, or a rotary coating device such as a Whaler, and is dried and crosslinked to cure. Next, a composition solution to form a photosensitive layer is applied and dried. [0082] A silicone rubber solution is applied onto the above photosensitive layer in a similar manner and heat-treated at a temperature of usually 100 to 120°C for several minutes to sufficiently cure the solution to form a silicone rubber layer. If necessary, a protective film can be provided on the silicone rubber layer using a laminator. Next, a method for manufacturing a printing plate that does not require dampening water using the plate material that does not require dampening water of the present invention will be explained. A positive film, which is the manuscript, is vacuum-adhered to the surface of the positive plate material and exposed. As a light source for this exposure, a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, etc., which generate abundant ultraviolet light, are used. Next, the positive film is peeled off and developed using a developer. [Example] Example 1 Production of aluminum plate a An aluminum plate with a thickness of 0.24 mm was immersed in a 3% aqueous sodium hydroxide solution, washed with water, and then immersed in a 32% aqueous sulfuric acid solution at a temperature of 5 A/dm2 at a temperature of 30°C. It was anodized for 10 seconds under the following conditions, washed with water, immersed in a 2% sodium metasilicate aqueous solution at a temperature of 85°C for 37 seconds, further immersed in water at a temperature of 90°C (pH 8.5) for 25 seconds, washed with water, and dried. , an aluminum plate a was obtained. [0085] A primer layer composition having the composition shown below was applied to an aluminum plate a, and after drying at 85°C for 3 minutes, 3K
The entire surface was exposed to light at 1000 mJ/cm2 using a W ultra-high pressure mercury lamp. Further dry at 100℃ for 4 minutes to a thickness of 15mm.
A primer layer of μm was formed. [Primer layer composition] Copolymer resin of 2-hydroxyethyl methacrylate and methyl methacrylate (50/50 molar ratio)
100 parts by weight pentaerythritol tetraacrylate
100 parts by weight DETX
(Polymerization initiator, manufactured by Nippon Kayaku Co., Ltd.)
5 parts by weight EPA (sensitizer, manufactured by Nippon Kayaku Co., Ltd.)
5 parts by weight Victoria Pure Blue BOH
200 parts by weight methyl lactate
1000
Parts by Weight Next, a concealing layer composition having the composition shown below was coated on the primer layer and dried at 100° C. for 2 minutes to form a concealing layer having a thickness of 1 μm. [Hiding layer composition] Copolymer resin of 2-hydroxyethyl methacrylate, N-(4-hydroxy phenyl) methacrylamide, and methacrylic acid in a molar ratio of 40/57/3.
1
00 parts by weight titanium dioxide

100 parts by weight methyl cellosolve

900 parts by weight 0088
Next, a photosensitive composition having the composition shown below was coated on the concealing layer and dried at 100° C. for 2 minutes to form a photosensitive layer having a thickness of 0.3 μm. [Photosensitive composition] (1) Diazo resin-1

50 parts (2) 2-hydroxyethyl methacrylate, N-(4-hydroxyphenyl) methacramide, methacrylic acid in a molar ratio of 40/57/3 copolymerized resin-1
50 parts by weight (3) Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd., dye)
1 part by weight (4) Methyl cellosolve
90
0 parts by weight Diazo resin-1 was synthesized as follows. p-diazodiphenylamine sulfate 14.5g (5
0 mmol) was dissolved in 40.9 g of concentrated sulfuric acid under ice cooling. 1.35 g (45 mmol) of paraformaldehyde was slowly added to this reaction solution so that the reaction temperature did not exceed 10°C. This reaction mixture was added dropwise to 500 ml of ethanol under ice cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 100 ml of pure water, and a cold concentrated aqueous solution containing 6.8 g of zinc chloride was added to this solution. The resulting precipitate was filtered, washed with ethanol, and dissolved in 150 ml of pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate was collected by filtration, washed with water, and then dried to obtain diazo resin-1. Next, the following silicone rubber composition was coated on the photosensitive layer to a dry film thickness of 1.8 μm.
It was dried at ℃ for 10 minutes. [Silicone rubber layer composition] (1) Dimethylpolysiloxane having hydroxyl groups at both ends (molecular weight 82,000)
100
Part by weight (2) Triacetoxymethylsilane
10 parts by weight (3) dibutyltin laurate
0.8
Weight part (4) Isopar E (manufactured by Esso Chemical)
900 parts by weight [0092] Next, a layer with a thickness of 5 μm was applied on the silicone rubber layer.
A single-sided matte polypropylene film was laminated to obtain a photosensitive lithographic printing plate that did not require dampening water. After a positive film was vacuum-adhered to the upper surface of the above plate material, it was exposed to light using a metal halide lamp as a light source. Next, after immersing it in the following developer for 1 minute,
By rubbing the surface of the plate material with a pad impregnated with developer, the silicone rubber layer, photosensitive layer, and hiding layer in the unexposed areas are removed, the halftone dots are well reproduced, and the unexposed image areas are removed. A printing plate was obtained in which a blue colored primer layer appeared in some areas. [Developer] β-anilinoethanol

0.5 part propylene glycol

1.0 part p-tert-butylbenzoic acid
1.0 part potassium hydroxide

1.0 copy
Polyoxyethylene lauryl ether
0.1 part potassium sulfite

2.0 parts potassium metasilicate

3.0 parts water


91 parts Example 2 In the primer layer composition of Example 1, Victoria Pure Blue-BOH was mixed with Mitsubishi Carbon Black MA-100.
(manufactured by Mitsubishi Kasei Corporation, pigment) and the hiding layer composition was changed as follows, the same procedure as in Example 1 was carried out to obtain a photosensitive lithographic printing plate that did not require dampening water. [Hidden layer composition] Copolymer resin-2 with a styrene/methacrylic acid molar ratio of 70/30 100 parts by weight calcium powder

100 parts by weight methyl cellosolve
900 parts by weight When exposure and development were carried out in the same manner as in Example 1, the silicone rubber layer, photosensitive layer and hiding layer in the unexposed areas were removed, the halftone dots were well reproduced, and the unexposed area in the image area was removed. A printing plate was obtained in which a black colored primer layer appeared in the exposed areas. Example 3 A dampening water-free photosensitive lithographic printing plate was obtained in the same manner as in Example 1, except that the compositions of the primer layer and hiding layer of Example 1 were changed as follows. [Primer layer composition] Epikote 1007 (epoxy resin, manufactured by Shell Oil Co., Ltd.) 50 parts by weight Hytanol 4010 (
Phenol resin, manufactured by Hitachi Chemical)
50 parts by weight ethyl cellosolve

360 parts by weight ethyl cellosolve acetate

360 parts by weight Shimla Fast Red 4
015
100 parts by weight butyl cellosolve

180 parts by weight [Hidden layer composition] Copolymer resin of p-hydroxystyrene/2-hydroxyethyl methacrylate/methacrylic acid in a molar ratio of 50/30/20-3 1
00 parts by weight zinc oxide

100 parts by weight methyl cellosolve

900 parts by weight 010
0] Exposure and development were carried out in the same manner as in Example 1.
The silicone rubber layer, photosensitive layer and hiding layer in the unexposed areas are removed, resulting in a printing plate in which halftone dots are well reproduced and a primer layer colored bright red appears in the unexposed areas, which are image areas. It was done. Effects of the Invention In the present invention, since a coloring agent is contained in a primer layer and a concealing layer is provided on the primer layer,
The images obtained are clear, and since the dyeing process is not required, the time required for the dyeing process can be saved.In addition, the staining solution does not stain hands or clothes, and furthermore, the automatic processor does not get dirty. A photosensitive lithographic printing plate that does not require dampening water and exhibits the following effects can be obtained. applicant
Konica Co., Ltd. Agent Patent Attorney
Mikio Nakajima

Claims (1)

[Claims] 1. A dampening water-free photosensitive lithographic printing plate comprising a primer layer, a photosensitive layer, and an ink repellent layer sequentially laminated on a substrate, wherein the primer layer contains a colorant, and the photosensitive layer and the primer layer A photosensitive lithographic printing plate that does not require dampening water and has a concealing layer between it.