JPH11109642A - Photosensitive planograph printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive planograph printing plate constituted so that mat grains are hardly peeled and crushed, the reproducibility of a dot is excellent and the deterioration of the reproducibility of the dot and the like caused by the light entering the circumference of the mat grains is improved as for the photosensitive planographic printing plate constituted so that the surface of a photosensitive layer is provided with fine ruggedness by the mat grains in order to obtain an excellent close contact state in a short time at a vacuum contact printing time. SOLUTION: This photosensitive planograph printing plate is constituted so that the surface of the photosensitive layer is made mat by dispersing and incorporating the grains in photosensitive liquid for coating the photosensitive layer. As the grains, the grain whose grains size is 0.5-20 μm and which is provided with rubber elasticity or the grains through which the light for exposing the photosensitive layer is not substantially transmitted (obtained by incorporating dye absorbing ultra violet rays in the grains) are used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate in which the surface on the photosensitive layer side of a photosensitive lithographic printing plate is matted (forming fine irregularities) in order to obtain good adhesion in a vacuum contact printing in a short time. Regarding the printing plate.

[0002]

2. Description of the Related Art Conventionally, in the plate making process for preparing a printing plate using a photosensitive lithographic printing plate, in order to adhere and print an original film, it is generally necessary to use a vacuum printing frame between a glass plate and a rubber sheet of the printing frame. A method of adhering an original image and a photosensitive lithographic printing plate (referred to as "vacuum adhesion method") is used.
In this vacuum contact method, matting is performed on the surface of the photosensitive layer of the photosensitive lithographic printing plate in order to obtain a sufficient contact state over the entire surface to be contacted in a short time.

As a method of mat processing, Japanese Patent Application Laid-Open No. 55-1
No. 2974 discloses a method in which a solid powder as a matting agent is powdered on the surface of a photosensitive layer and then fixed by heat or the like. However, in the method of forming a mat by powdering, it is necessary to use a material having a low thermal softening point in order to fuse the photosensitive layer at such a low temperature that does not cause thermal denaturation. Such materials generally have low mechanical strength,
There is a problem in that the matting agent particles are crushed during vacuum contact and it takes a long time to adhere. In addition, the formed matting agent particles usually do not have a hemispherical shape or a hat shape, and such a shape is such that the shape is deformed (crushed) by the pressure of the glass surface at the time of vacuum adhesion, and the vacuum adhesion time is increased. Has disadvantages.

Japanese Patent Application Laid-Open No. 56-9739 discloses a method of forming a mat by using a photosensitive layer containing fine particles. This method does not cause problems such as peeling, but it is necessary to use matte particles having a large particle size to protrude from the surface, and since large particles pop out from the surface of the photosensitive layer, the original film rises and becomes small. There is a problem that the reproducibility of points is deteriorated, and when transparent mat particles are used, light is refracted, and halation is caused to cause fog around the mat particles, small dots and chipped image portions. In order to solve this problem,
Japanese Patent No. 23858 discloses a technique using mat particles having the same refractive index as the material forming the photosensitive layer, but the effect is not sufficient.

JP-A-57-34558 discloses a method in which an aqueous liquid in which a resin is dissolved or dispersed is sprayed and dried to fix the resin on the surface of a photosensitive layer to form a mat. Although this method is advantageous in terms of safety and health because an aqueous solution is used, however, since it uses a water-soluble material as a matting agent, it is inferior in adhesiveness to the material forming the photosensitive layer. Is peeled off, and it takes a long time for vacuum adhesion. In addition, since the aqueous liquid in which the resin is dissolved or dispersed has high viscosity, water does not have fluidity when attached to the surface of the photosensitive layer due to high viscosity of the aqueous solution, and the matte particles attached to the surface of the photosensitive layer are smaller than the particle size. It is usual to form a shape with a height. Since the matting agent particles having such a shape have a height, the particles are crushed by the pressure when the particles adhere to the glass surface, and the vacuum adhesion time is lengthened. Since the pressure concentrates on the edge of the film, there is a problem that the image reproducibility changes only in that portion.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and a first object of the present invention is to provide a matting agent for forming a surface mat for vacuum adhesion. To provide a photosensitive lithographic printing plate which is less likely to be peeled or crushed, and has good reproducibility of small dots.
It is an object of the present invention to provide a photosensitive lithographic printing plate which is less likely to cause fog around the mat particles due to light circling around the mat particles.

[0007]

The first object of the present invention is attained by the following (1), (4) or (5), and the second object is attained by the following (2) to (5).

(1) In a photosensitive lithographic printing plate in which the surface of the photosensitive layer is matted by dispersing and containing particles in a photosensitive solution for coating the photosensitive layer, the particles have a particle size of 0. A photosensitive lithographic printing plate comprising particles having a rubber elasticity of 0.5 to 20 μm.

(2) In a photosensitive lithographic printing plate wherein the surface of the photosensitive layer is matted by dispersing particles in a photosensitive solution for coating the photosensitive layer, the photosensitive layer is used as the particles. A photosensitive lithographic printing plate comprising particles that do not substantially transmit light to be exposed.

(3) The wavelength of light for exposing the photosensitive layer is 45.
The photosensitive lithographic printing plate according to the above (2), wherein the thickness is 0 nm or less.

(4) In a photosensitive lithographic printing plate in which the surface of the photosensitive layer is matted by dispersing particles in a photosensitive solution for coating the photosensitive layer, the particles have a particle size of 0. A photosensitive lithographic printing plate comprising particles having a rubber elasticity of 0.5 to 20 μm and substantially not transmitting light for sensitizing the photosensitive layer.

(5) The wavelength of light for exposing the sensitive layer is 45
(4) The photosensitive lithographic printing plate as described in (4) above, wherein the thickness is 0 nm or less.

Hereinafter, the present invention will be described in detail.

The photosensitive lithographic printing plate of the invention according to claims 1 to 5 basically has a photosensitive layer provided on a support and is used for preparing a lithographic printing plate or the like. is there.

The support includes a plate-like material having good dimensional stability used as a plate material of a lithographic printing plate. Such supports include roughened aluminum supports. Examples of the roughening method include a method of mechanically roughening the surface, a method of electrochemically roughening the surface, and a chemically roughening method of roughening the surface with an etching agent composed of an alkali, an acid, or a mixture thereof. It is possible to use a conversion method or a method combining these. The roughened aluminum support is subjected to anodic oxidation treatment and sealing treatment as required. The aluminum support can be provided with a hydrophilic layer. Further, a protective layer can be provided on the back surface of the support in order to prevent scratches on the photosensitive layer when the photosensitive lithographic printing plates are stacked and to prevent elution of the aluminum component into the developing solution during development. . For details of the support, reference can be made to UK Patent Publication No. 2030309A.

The photosensitive layer includes a positive photosensitive layer containing an o-quinonediazide compound as a photosensitive component, a negative photosensitive layer containing a photosensitive diazonium salt or a photosensitive azide compound as a photosensitive component, and an addition-polymerizable ethylenically unsaturated compound. Negative-type photopolymerizable compositions containing a compound having a heavy bond as a main component, and photocrosslinkable compounds containing a cinnamic acid or a dimethylmaleimide group as photosensitive components are included.

As the photosensitive component, a resin obtained by polycondensing a polyhydric phenol such as phenol, cresol and / or pyrogallol with an active carbonyl compound such as formalin or acetone is esterified with o-quinonediazidesulfonic acid, or O-Polyhydroxy polynuclear compounds such as polyhydroxybenzophenones or bisphenol
Those esterified with naphthoquinonediazidesulfonic acid are mentioned.

The photosensitive layer usually contains a binder resin.
Examples of the binder resin include a resin obtained by polycondensing cresol and / or phenol with formalin (generally referred to as a novolak resin).

These photosensitive layers are known, and details thereof can be referred to, for example, in British Patent Publication No. 2030309A.

In the invention according to the first, fourth or fifth aspect of the present invention, the photosensitive solution has rubber elasticity and a particle size of 0.5 to 0.5.
As the particles having a size of 20 μm (hereinafter, referred to as “rubber-based mat particles”), a particulate carboxyl group-containing diene polymer having a crosslinked structure (hereinafter, referred to as “component (1)”) can be used. The polymer has a repeating unit composed of an aliphatic conjugated diene as an essential component, and has at least one of a particulate carboxyl group-containing diene polymer having a crosslinked structure.
Consists of seeds.

The crosslinked structure in the component (1) can be introduced simultaneously with the production of the carboxyl group-containing diene polymer and / or after the production of the carboxyl group-containing diene polymer. It is preferable to introduce a crosslinked structure at the same time as the production of the coalescence.

The particulate component (1) is prepared by emulsion polymerization,
The carboxyl group-containing diene polymer can be obtained simultaneously with the production of the carboxyl group-containing diene polymer by suspension polymerization, precipitation polymerization, or the like. It can also be obtained by obtaining the system polymer in the form of particles. The particulate component (1) is preferably produced by emulsion polymerization using a radical polymerization initiator, suspension polymerization or a combination thereof. From the viewpoints of particle size and particle size uniformity, emulsion polymerization is particularly preferred. It is preferable to manufacture by.

The carboxyl group-containing diene polymer in the component (1) may be, for example, (a-1) an aliphatic conjugated diene, a carboxyl group-containing unsaturated monomer and a monomer having at least two polymerizable unsaturated groups. A method of copolymerizing a body, optionally with another monomer, (A-2)
After copolymerizing an aliphatic conjugated diene and a monomer having at least two polymerizable unsaturated groups, optionally together with other monomers, the resulting copolymer is subjected to carboxylation treatment, for example, maleic anhydride. Can be produced by an addition reaction of an unsaturated carboxylic acid (anhydride) such as, and subsequent hydrolysis as required.
The method 1) is preferred.

Examples of the aliphatic conjugated diene include butadiene, isoprene, 1,3-pentadiene, 1,3-
Hexadiene, 2,3-dimethylbutadiene, 4,5-
Diethyl-1,3-octadiene, 3-butyl-1,3
-Octadiene, chloroprene, 2,3-dichlorobutadiene, 1,3-cyclopentadiene and the like.

Preferred aliphatic conjugated dienes are butadiene, isoprene and the like. These aliphatic conjugated dienes can be used alone or in combination of two or more.

Examples of the unsaturated monomer having a carboxyl group include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid and cinnamic acid; maleic anhydride, fumaric acid, itaconic acid anhydride, citracone Unsaturated polycarboxylic acids (anhydrides) such as acids and mesaconic acids; free carboxyl group-containing esters such as monomethyl esters, monoethyl esters and monopropyl esters of the unsaturated polycarboxylic acids; Nitriles containing a free carboxyl group such as mononitrile; amides containing a free carboxyl group such as the monoamide of the unsaturated polycarboxylic acid; mono (2-hydroxyethyl ester) and mono (2-hydroxypropyl ester) of the unsaturated polycarboxylic acid ) And other free carboxyl group-containing hydroxyalkyl esters; In addition to the N-hydroxyalkyl derivatives of the free carboxyl group-containing amides of the unsaturated polycarboxylic acids, non-polymerizable polycarboxylic acids such as succinic acid, adipic acid, phthalic acid and unsaturated alcohols, 2-hydroxyethyl (meth) Examples include free carboxyl group-containing esters with a hydroxyl group-containing unsaturated compound such as acrylate.

Preferred unsaturated monomers having a carboxyl group are (meth) acrylic acid, monovinyl succinate, monoester of succinic acid and 2-hydroxyethyl (meth) acrylate, and phthalic acid and 2-hydroxyethyl (meth) acrylate. Monoester with acrylate and the like. These carboxyl group-containing unsaturated monomers can be used alone or in combination of two or more.

Examples of the compound having at least two unsaturated groups include di (alkylene glycol) such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. (Meth) acrylates; polyalkylene glycols such as polyethylene glycol and polypropylene glycol (the number of alkylene glycol units is, for example, 2
20) di (meth) acrylates; both ends hydroxypolybutadiene, both ends hydroxypolyisoprene,
Di (meth) acrylates of polymers containing hydroxyl groups at both ends of molecular chains such as hydroxybutadiene-acrylonitrile copolymer at both ends and hydroxypolycaprolactone at both ends; glycerin, 1,2,4-butanetriol,
Trimethylol alkane (Alkane has, for example, 1 carbon atom
To 3), poly (meth) acrylates of trihydric or higher polyhydric alcohol such as tetramethylolalkane (alkane has 1 to 3 carbon atoms); poly of polyalkylene glycol adduct of trihydric or higher polyhydric alcohol (Meth) acrylates; 1,4-cyclohexanediol, 1,4-
Di (meth) acrylates of cyclic polyols such as benzenediol; polyester resin (meth) acrylate;
Oligo (meth) acrylates such as epoxy resin (meth) acrylate, urethane resin (meth) acrylate, alkyd resin (meth) acrylate, silicone resin (meth) acrylate, and spirane resin (meth) acrylate; N, N'-methylenebis ( (Meth) acrylamide, N, N'-ethylenebis (meth) acrylamide,
Bis (meth) acrylamides such as N, N'-hexamethylenebis (meth) acrylamide; polyvinyl aromatic compounds such as divinylbenzene, diisopropenylbenzene, and trivinylbenzene; non-polymer polystyrene such as divinylphthalate and diallylphthalate Poly (unsaturated alcohol esters) of carboxylic acids; and polyfunctional unsaturated ethers such as divinyl ether and diallyl cartel.

Preferred compounds having at least two unsaturated groups are di (meth) acrylates of alkylene glycols such as ethylene glycol and polyvinyl aromatic compounds such as divinylbenzene. These compounds having at least two unsaturated groups may be used alone or
A mixture of more than one species can be used.

Further, the monomer other than the above-mentioned is not particularly limited, but specific examples thereof include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p
-T-butylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene,
1,1-diphenylethylene, N, N'-dimethyl-p
-Aminostyrene, N, N-diethyl-p-aminostyrene, vinylpyridine, vinylpiperidine, vinylpiperazine, vinylfuran, vinylthiophene, vinylthiazole, N-vinylpyrrolidone, N-vinylcarbazole, (meth) acrylonitrile, α- Chloroacrylonitrile, α-methoxyacrylonitrile, α-ethoxyacrylonitrile, nitrile crotonic acid, nitrile cinnamate, dinitrile itaconate, dinitrile maleate,
Fumaric acid dinitrile, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N, N-bis (2-hydroxyethyl) (meth) acrylamide,
Crotonic amide, cinnamamide, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec -Butyl (meth) acrylate, t-butyl (meth) acrylate, n-amyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate , Methyl crotonate, ethyl crotonate, propyl crotonate, butyl crotonate, methyl cinnamate, ethyl cinnamate, propyl cinnamate, butyl cinnamate, dimethyl itaconate, diethyl itaconate, dimethyl maleate, maleate Diethyl, diethyl fumarate, diethyl fumarate, vinyl chloride, vinylidene chloride, vinyl acetate, there are allyl acetate and the like.

Other preferred monomers are styrene, (meth) acrylonitrile, methyl (meth) acrylate,
Ethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and the like. These other monomers are
They can be used alone or in combination of two or more.

In the carboxyl group-containing diene copolymer, the content of the aliphatic conjugated diene, the carboxyl group-containing unsaturated monomer and the compound having at least two unsaturated groups constitutes the copolymer. Based on the total amount of the monomer components, the aliphatic conjugated diene is usually 10
~ 95 mol%, preferably 30-90 mol%,
The unsaturated compound containing a carboxyl group is usually 0.1 to 3
0 mol%, preferably 0.2 to 20 mol%, and a compound having at least two unsaturated groups is usually
0.01 to 20 mol%, preferably 0.1 to 10 mol%
It is. The content of the other monomer is 7% of the monomer component.
0 mol% or less.

Examples of the radical polymer initiator used for the emulsion polymerization and the like include benzoyl peroxide, lauroyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, paramenthane hydroperoxide, di-t-butyl peroxide, dicumyl. Organic peroxides such as peroxides; azo compounds such as azobisisobutyronitrile, azobisisovaleronitrile, and azobisisocapronitrile; inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide; A redox catalyst comprising an organic peroxide or an inorganic peroxide and a reducing agent such as an organic amine, ferrous sulfate, sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, L-ascorbic acid, sulfinic acid, etc. This Can.

As the emulsifier used in the emulsion polymerization, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants and the like can be used. Agents and nonionic surfactants are preferred. These surfactants are
It can also be a fluorine-based surfactant. In the emulsion polymerization, a suspension stabilizer or a thickener as described below can be used in combination with an emulsifier in order to adjust the viscosity, the particle size, and the like of the reaction system.

The suspension stabilizer used in the suspension polymerization includes polyvinyl alcohol, sodium polyacrylate, methyl vinyl ether-maleic anhydride copolymer, water-soluble polyether, hydroxyethyl cellulose, carboxymethyl cellulose, starch. , Gelatin, casein, alginate and the like. In suspension polymerization, the emulsifier can be used in combination with a suspension stabilizer, if desired.

In each of the above polymerizations, the reaction components such as a monomer and a radical polymerization initiator may be added in their entirety before the start of the reaction, or a part or all of them may be divided or continuously added after the start of the reaction. May be added. The polymerization reaction is usually
The reaction is carried out at 0 to 60 ° C. in an atmosphere from which oxygen has been removed (for example, nitrogen). However, operating conditions such as a temperature and a stirring speed can be appropriately changed during the reaction. The polymerization reaction is continuous,
It can be implemented in any of the batch systems.

The component (1) can be used alone or in combination of two or more.

In the invention according to claim 1, 4, or 5,
The rubber-based mat particles have a particle size of 0.5 to 20 μm.
If the particle size is less than 0.5 μm, sufficient vacuum adhesion performance cannot be obtained, and if it exceeds 20 μm, the reproducibility of small points deteriorates.

The particle size of the rubber type mat particles is preferably 1 to 10 μm, more preferably 3 to 10 μm. The addition amount of the rubber size matting particles preferably 10 to 200 mg / m ² as the weight of the rubber size matting particles after drying, more preferably from 20 to 100 mg / m ^2.

The rubber-based mat particles can be produced by kneading rubber fine particles into the above polymer, followed by pulverization and fractionation.

In the invention according to claim 1, 4, or 5,
The amount of rubber-based matte particles added is 0.1 to the photosensitive layer.
10 to 10% by weight is suitable, preferably 0.1 to 5% by weight, and more preferably 0.5 to 3% by weight.

In the invention according to claim 2 or 4, the particles which are contained in the photosensitive solution and which do not substantially transmit light for sensitizing the photosensitive layer (hereinafter, also referred to as “light-impermeable mat particles”) are photosensitive. Particles obtained by adding a dye that absorbs light in a wavelength region where the photosensitive layer is sensitive to a polymer that is insoluble in a solvent contained in the photosensitive solution for forming the layer can be preferably used. As the dye, an ultraviolet absorbing dye can be used for the photosensitive layer having sensitivity to light of 450 nm or less in the invention according to claim 3 or 5.

Here, "substantially does not transmit light for exposing the photosensitive layer" means a transmittance which does not cause fogging due to light wrapping around mat particles in image exposure of a photosensitive lithographic printing plate. It means that it is good.

As the polymer, polyethylene or polypropylene is preferable, and a copolymer containing a monomer unit formed from each of the following monomers (a), (b) and (c) is preferably used. Can be.

(A) The alkyl residue has 2 carbon atoms
And at least one monomer selected from the group consisting of alkyl acrylates having 10 to 10 and alkyl methacrylates having 4 to 10 carbon atoms in the alkyl residue.

Specifically, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-
Butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate,
n-octyl acrylate, n-decyl acrylate,
Examples include n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, and n-decyl methacrylate.

(B) styrenes, acrylonitriles,
At least one monomer selected from the group consisting of methyl methacrylate and ethyl methacrylate.

Specifically, styrene, o- / m- / p-
Methylstyrene, 2,4-dimethylstyrene, 2,5-
Dimethylstyrene, 3,4-one dimethylstyrene, 3,
5-dimethylstyrene, 2,4,5-trimethylstyrene, 2,4,6-trimethylstyrene, o- / m- / p
-Ethylstyrene, 3,5-diethylstyrene, 2,
4,5-triethylstyrene, pn-butylstyrene, m-sec-butylstyrene, m-tert-butylstyrene, p-hexylstyrene, pn-heptylstyrene, p-2-ethylhexylstyrene, o- / m
-/ P-fluorostyrene, o- / m- / p-chlorostyrene, 2,3-dichlorostyrene, 2,4-dichlorostyrene, 2,5-dichlorostyrene, 2,6-dichlorostyrene, 3,4- Dichlorostyrene, 3,5-dichlorostyrene, 2,3,4,5,6-pentachlorostyrene, m-trifluoromethylstyrene, o- / m-cyanostyrene, m- / p-nitrostyrene, o-dimethyl Examples include aminostyrene, acrylonitrile, α-chloroacrylonitrile, α-bromoacrylonitrile, methyl methacrylate, ethyl methacrylate, and the like.

(C) at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid, alkali metal salts and ammonium salts thereof.

Specifically, acrylic acid, sodium acrylate, potassium acrylate, ammonium acrylate, methacrylic acid, sodium methacrylate, potassium methacrylate, ammonium methacrylate, maleic acid, sodium maleate, a potassium maleate, maleate Ammonium itaconate, itaconic acid, sodium itaconate, potassium itaconate, ammonium itaconate, and the like.

The copolymerization ratio in the above copolymer is (a)
10-70% by weight, (b) 20-80% by weight and (c)
It is preferably from 6 to 50% by weight, particularly preferably (a) 15
To 50% by weight, (b) 40 to 70% by weight, (c) 10 to 10% by weight.
25% by weight.

The above polymer preferably has water solubility or alkali solubility. Specifically, an acrylic copolymer containing methacrylic acid or acrylic acid as a main component or a copolymer containing methacrylic acid or an ammonium salt of acrylic acid as a main component is preferable.

The light-impermeable matting particles according to the second or third aspect of the present invention may be subjected to a surface treatment for improving the affinity with the photosensitive solution, and a range which does not impair the effects of the present invention. May contain other additives such as a dispersant and a surfactant.

According to the fourth or fifth aspect of the present invention, as the light-impermeable matting particles, a dye that absorbs light in a wavelength range where the photosensitive layer is sensitive (to the ultraviolet-sensitive photosensitive layer) is added to the rubber-based matting particles. And an ultraviolet absorbing dye).

Known UV absorbing dyes can be used. Specific examples include Tartrazine, Diaresin Brilliant Yellow 6G (manufactured by Mitsubishi Chemical Corporation), Diaresin Yellow 3G (manufactured by Mitsubishi Chemical Corporation), Kayaset Yellow K-RL (manufactured by Nippon Kayaku Co., Ltd.) Kayaset Yellow K-CL (manufactured by Nippon Kayaku Co., Ltd.), hydroxybenzophenone, phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, 2,4-dihydroxybenzene, 2-hydroxy-4- Methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2, -hydroxy-4 Methoxy-5-sulfobenzophenone, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2-
(2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert
-Butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-ter
(t-amylphenyl) benzotriazole, 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, ethylhexyl-2-cyano-3,3'-diphenylacrylate and the like. Further, the ultraviolet absorbing dyes described in JP-A-4-39649 and JP-A-4-39662 can be used. Further, the following ultraviolet absorbing dyes can be used.

(CI means Color Index) Lemon Chrome Yellow M35 (CI.77603) Medium Chrome Yellow (CI.77600) Molypdate Orange (CI.77605) Seika First Yellow 10GH (CI.11710) Seika First Yellow GH (CI.11680) Seika First Yellow 2015 (CI.11741) Seika First Yellow A-3 (CI.11737) Seika First Yellow 2300 (CI. I.21090) Seika First Yellow 2200 (CI.21095) Seika First Yellow 2400 (CI.21105) Seika First Yellow 2600 (CI.21100) Seika First Yellow 250 (C.I. 21096) Seika First Yellow 2720 (C.I. 21108) Chromo Fine Yellow 5910 (C.I. 200335) Shimler First Yellow 8GTF (C.I. 21105) manufactured by Dainippon Seika Co., Ltd. First Yellow 4186 (CI. 11767) Shimla First Yellow 4193G (CI. 21100) Shimla First Yellow GHK-N4 (CI. 21090) Shimla First Yellow GTF230T (CI not listed.) Shimla First Yellow RF (C.I. 21096) Shimla Fast Yellow 4181 (C.I. 21108) Fast Gen Super Yellow GRO (C.I. 56280) Tal yellow GT (C.I.11680) No. 7100 Lionol Yellow (CI. 21096) Lionol Yellow FGG-3 (CI. 21127) Lionol Yellow NBR (CI. 21108) Lionol Yellow 1806-G (CI. 21127) Lionol Yellow K-5G (CI. 13960) Lionol Yellow K-2R (CI. 13955) Lionol Yellow FGG-3 (CI. 21127) Lionol Blue 7210-V (CI. 74160) Lionon Yellow GF (CI. 70600) Lionon Yellow 3G-F (CI not listed) Lionon Yellow RX-F (CI. 66280) Auramine (CI.41000) carotene brilliant flavin (CI. Basic 1) ) Benzidine Yellow 4T-564D (CI. 21095) Further, o-naphthoquinonediazide-4 or 5-sulfonic acid ester compound, trihalomethyloxadiazole compound, trihalomethyltriazine compound, etc. may be used as an ultraviolet absorbing dye. Can be.

In the invention according to claim 2 or 3, the size of the light-impermeable mat particles is preferably 1 to 10 μm,
More preferably, it is 1 to 5 μm. The addition amount of the light-impermeable matting particles is suitably from 0.1 to 10% by weight, preferably from 0.1 to 5% by weight, and more preferably from 0.5 to 3% by weight, based on the photosensitive layer. .

In the inventions according to the first to fifth aspects, as a method for dispersing the matte particles in the photosensitive solution, a known dispersion method using beads or a homogenizer can be used. Further, a method of dispersing in a solvent used for a photosensitive solution for coating a photosensitive layer, mixing the dispersion with the photosensitive solution and stirring the dispersion is effective for preventing deterioration of the photosensitive layer components due to dispersion.

[0059]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Parts in Examples and Comparative Examples indicate parts by weight.

Example 1 (Example of the invention according to claim 1) Preparation of rubber-based mat particles (1) Butadiene / methacrylic acid / ethylene glycol dimethacrylate / ethyl acrylate (76/10 in molar ratio)
/ 2/12), emulsifier with sodium lauryl sulfate, A
Polymerization was carried out at 70 ° C. for 10 hours using IBN as a polymerization initiator. After the polymerization, hydroquinone was added as a polymerization inhibitor. After cooling, salting out with calcium chloride
After drying, rubber-based mat particles (1) were prepared. The average particle size of the rubber mat particles (1) was 4 μm.

Preparation of Support A 0.24 mm-thick aluminum plate was degreased in a 5% aqueous sodium hydroxide solution, and then in a 0.5 molar hydrochloric acid aqueous solution at a temperature of 25 ° C. and a current density of 60 A / d.
Electrolytic etching was performed under the conditions of m ² and a processing time of 30 seconds. Next, after a desmutting treatment was performed in a 5% aqueous sodium hydroxide solution, an anodic oxidation treatment was performed in a sulfuric acid solution. The amount of the anodic oxide film was 20 mg / dm ² . Next, it was immersed in hot water at 90 ° C. to perform a sealing treatment to obtain a lithographic printing plate support.

A photosensitive solution (1) having the following composition was applied on the support and dried to prepare a photosensitive lithographic printing plate (1).

Composition of Photosensitive Solution (1) Novolak 7.5 parts Naphthoquinone diazide compound 2.5 parts Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.08 parts Triazine compound 0.10 parts Tetrahydrophthalic acid 0 0.3 parts Solvent Rubber-based mat particles (1) 0.3 part Example 2 Same as Example 1 except that rubber-based mat particles (2) were used in place of rubber-based mat particles (1). Thus, a photosensitive lithographic printing plate (2) was prepared.

Preparation of Rubber Mat Particles (2) Butadiene / methacrylic acid / ethylene glycol dimethacrylate / ethyl acrylate (76/10 in molar ratio)
/ 2/12) was added with 1 mol% of phenyl salicylate as an ultraviolet absorber, and this mixture was treated at 70 ° C. with sodium lauryl sulfate as an emulsifier and AIBN as a polymerization initiator.
For 10 hours. After the polymerization, hydroquinone was added as a polymerization inhibitor. After cooling, the precipitate was coagulated by salting out with calcium chloride and dried to prepare rubber-based mat particles (2). The average particle size of the rubber mat particles (2) is 4μ.
m.

Comparative Example 1 The same procedures as in Example 1 were carried out except that the photosensitive solution (3) using silica particles instead of the rubber-based matte particles (1) in the composition of the photosensitive solution (1) was used as the photosensitive solution. Similarly, a photosensitive lithographic printing plate (3) was obtained.

COMPARATIVE EXAMPLE 2 A photosensitive layer was formed by using a photosensitive solution (4) having a composition excluding the rubber mat particles (1) in the composition of the photosensitive solution (1). The following mat particles (3) were evenly sprayed on the sample coated with (a spray amount was 30 mg /
m ² ), and then a photosensitive lithographic printing plate (4) was prepared in the same manner as in Example 1 except that the mat was formed by treating at 120 ° C. for 15 seconds.

Preparation of Comparative Matt Particles (3) Acrylic resin of styrene / butyl acrylate / acrylic acid (40/30/30 in molar ratio) was pulverized to a particle size of 2 to 3.
It was fractionated to 5 μm.

Comparative Example 3 A photosensitive solution was prepared in the same manner as in Example 1 except that a photosensitive solution (5) having a composition obtained by removing the rubber-based matte particles (1) from the composition of the photosensitive solution (1) was used. A lithographic printing plate (5) was prepared.

For the photosensitive lithographic printing plates (1) to (5), the time required for vacuum contact, the ease with which the mat particles were crushed, and the reproducibility of small spots were measured by the following methods.

Time Required for Vacuum Adhesion A 1000 mm × 800 mm sample and a 50% halftone chart (size: 900 mm × 600 mm) were set on an exposure machine, and vacuum adhesion was performed, and the time required for adhesion was measured.

Easiness of crushing of the mat particles In advance, the exposure device is exposed to the air for a sufficient time, and the glass surface of the exposure device is warmed to about 40 ° C. 1000mm x 80 in this state
50% halftone chart thickness on a 0 mm sample (0.3 mm)
, And a 0.3 mm transparent film is further placed on the halftone dot chart so as to cover half of the halftone chart, vacuum is applied for 2 minutes, and exposure is performed for 1 minute. Thereafter, development was performed, and the dot quality of the end where the transparent film was placed was examined in the obtained dot image. The edge part of the transparent film, which is under the highest pressure, is easily crushed. If crushed, the halftone dot chart adheres to the plate surface only at that part and the halftone dot becomes large (the edge part looks like a line after development). Of FOGRA chart on photosensitive lithographic printing plate 1
Exposure for 60 seconds after vacuum contact for 5 minutes. The fine line of the completely reproduced FOGRA chart after development is measured. The reproducibility of the fine line indicates the reproducibility of a small point, and the good reproducibility of the fine line indicates that light is less wrapped around the mat particles.

The above results are shown in Table 1 below.

[0073]

[Table 1]

[0074]

According to the first, fourth or fifth aspect of the present invention, in order to obtain good adhesion in a short time in vacuum adhesion printing, a photosensitive lithographic printing plate in which the surface of the photosensitive layer is provided with minute irregularities by matting particles. In this case, a photosensitive lithographic printing plate in which the matting particles are hardly peeled or crushed and the reproducibility of small points is good can be obtained.

According to the invention as set forth in claims 2 to 5, in the photosensitive lithographic printing plate in which fine irregularities are provided on the surface of the photosensitive layer by mat particles in order to obtain good adhesion in a short time in vacuum adhesion baking, A photosensitive lithographic printing plate in which the deterioration of the reproducibility of small spots due to the light circling around the plate can be improved.

Claims (5)

[Claims] 1. A photosensitive lithographic printing plate in which the surface of the photosensitive layer is matted by dispersing and containing particles in a photosensitive solution for coating the photosensitive layer, wherein the particles have a particle size of 0.1. A photosensitive lithographic printing plate comprising particles having a rubber elasticity of 5 to 20 μm. 2. In a photosensitive lithographic printing plate wherein the surface of the photosensitive layer is matted by dispersing and containing particles in a photosensitive solution for coating the photosensitive layer, the photosensitive layer is exposed as the particles. A photosensitive lithographic printing plate comprising particles that do not substantially transmit light to be applied. 3. The wavelength of light for exposing the photosensitive layer is 450 n.
3. The photosensitive lithographic printing plate according to claim 2, wherein m is equal to or less than m. 4. In a photosensitive lithographic printing plate in which the surface of the photosensitive layer is matted by dispersing and containing particles in a photosensitive solution for coating the photosensitive layer, the particles have a particle size of 0.1. A photosensitive lithographic printing plate characterized in that the lithographic printing plate contains particles having a rubber elasticity of 5 to 20 μm and substantially not transmitting light for sensitizing the photosensitive layer. 5. The wavelength of light for exposing the photosensitive layer is 450 nm.
The photosensitive lithographic printing plate according to claim 4, wherein m is equal to or less than m.