JPH10288841A - Photosensitive planographic printing plate and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive planographic printing plate which is sufficient in the adhesiveness between a matting agent and a photosensitive layer surface, is free from the deterioration of vacuum adhesiveness by the dislodgment of the matting, yields good printed matter with a good inking property, has the sufficient adhesiveness between the matting agent and the photosensitive layer surface and has a good vacuum adhesion property without being collapsed by the pressure in exposure by a vacuum contact method. SOLUTION: This photosensitive planographic printing plate is formed by providing the surface of a base with the photosensitive layer, spraying a liquid prepd. by dissolving or dispersing a resin into an org. solvent to its surface and drying the liquid to fix the resin to a rugged form on the surface of the photosensitive layer. The resin described above has properties (solubility in an aq. alkaline soln., etc.) different from the properties of the main component (binder resin, etc.) of the photosensitive layer. The rugged form described above is trapezoidal in its section and the diameter of the base thereof is 5 to 3 0μm. The height of the rugged form is 1 to 5 μm and the average grain size is preferably 5 to 20 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for forming fine irregularities provided on the surface of a photosensitive layer of a photosensitive lithographic printing plate in order to obtain good contact in a short time in vacuum contact printing.

[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. 2,974 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 a material generally has a problem that mechanical strength is weak, and it takes a long time until the matting agent particles are crushed at the time of vacuum contact and adhere. Also, the formed matting agent particles usually have no hemispherical shape or hat shape,
Such a shape has a drawback that the shape is deformed (crushed) by the pressure of the glass surface at the time of vacuum contact, and the vacuum contact time becomes long.

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.

JP-A-4-46343 discloses a method of forming a photosensitive layer by spraying a main photosensitive layer component of a photosensitive lithographic printing plate. However, the photosensitive lithographic printing plate that has been matted by this method is inferior in ink deposition during printing due to the unevenness of the image area even after exposure and development, and is relatively larger than a halftone dot, especially a solid color. The density of the image area is not uniform and good printed matter cannot be obtained.

[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 which has sufficient adhesiveness to the photosensitive layer surface, A photosensitive lithographic printing plate which is free from deterioration in vacuum adhesion due to dropping off of a matting agent, has excellent ink deposition properties, and can obtain good printed matter (particularly, uniform density of solid portions). A second object is to provide a photosensitive lithographic printing plate in which the matting agent is not crushed even by pressure during exposure, the matting agent has sufficient adhesion to the surface of the photosensitive layer, and has good vacuum adhesion. .

[0007]

The first object is achieved by the following (1) to (3), and the second object is achieved by the following (4) to (8).

(1) A photosensitive layer is provided on a support, and a liquid obtained by dissolving or dispersing a resin in an organic solvent is sprayed on the surface of the photosensitive layer, and the resin is dried and dried to fix the resin on the surface of the photosensitive layer in an uneven manner. A photosensitive lithographic printing plate, wherein the resin has different physical properties from the main components of the photosensitive layer.

(2) The photosensitive lithographic printing plate as described in (1) above, wherein the physical properties are solubility in an aqueous alkaline solution.

(3) A main component of the photosensitive layer is a compound obtained by esterifying an o-quinonediazide compound with a polycondensate of phenol and / or polyhydric phenol and a polycondensate of cresol and / or phenol. The photosensitive lithographic printing plate according to the above (1).

(4) A photosensitive layer is provided on a support, and a liquid obtained by dissolving or dispersing the resin in an organic solvent is sprayed on the surface of the photosensitive layer, and the sprayed fine particles are adhered to the surface and dried. In a photosensitive lithographic printing plate fixed to the surface of the photosensitive layer in a concavo-convex shape, the concavo-convex shape has a trapezoidal cross section and a bottom surface diameter of 5 to 30 μm. Edition.

(5) The method according to (4), wherein the fine particles flow sufficiently even when they adhere to the surface of the photosensitive layer.
5. A method for producing a photosensitive lithographic printing plate, which comprises producing the photosensitive lithographic printing plate described in 1. above.

(6) The solution in which the resin is dissolved or dispersed in an organic solvent has a solid content of 5 to 20%, and a solvent having a boiling point of 100 to 200 ° C. is used as the organic solvent. A method for producing a photosensitive lithographic printing plate for producing the photosensitive lithographic printing plate according to (4).

(7) A photosensitive layer is provided on a support, and a liquid in which a resin is dissolved or dispersed in an organic solvent is sprayed on the surface of the photosensitive layer, and the sprayed fine particles are adhered to the surface and dried. In a photosensitive lithographic printing plate fixed to the surface of the photosensitive layer in an uneven manner, the height of the unevenness is 1 to 5;
A photosensitive lithographic printing plate having a thickness of 5 μm and an average particle size of 5 to 20 μm.

(8) The photosensitive lithographic printing plate as described in (7) above, wherein the liquid has a solid concentration of 10 to 40% and the organic solvent has a boiling point of 100 to 200 ° C. For producing a photosensitive lithographic printing plate.

Hereinafter, the present invention will be described in detail.

The photosensitive lithographic printing plate of the invention according to claims 1 to 8 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 having good dimensional stability and 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 may be 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, 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 polycondensation of 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 Polyhydroxybenzophenones or polyhydroxy polynuclear compounds such as bisphenol
And those esterified with naphthoquinonediazidesulfonic acid.

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, British Patent Publication No. 2030309A.

In the first to eighth aspects of the present invention, the resin to be fixed to the surface of the photosensitive layer in an uneven manner is, for example, formed from each of the following monomers (a), (b) and (c). And copolymers containing monomer units.

(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-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.

In the inventions according to claims 4 to 8, the resin to be fixed on the surface of the photosensitive layer 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.

In the inventions according to the first to eighth aspects, the resin to be fixed to the surface of the photosensitive layer in an uneven shape may contain additives other than the resin. As additives, for example, silicon dioxide, zinc oxide, titanium oxide, zirconium oxide,
Fillers such as glass particles, alumina, and polymer particles (for example, particles of polymethyl methacrylate, polystyrene, phenol resin, and the like) are included.

In the invention according to claims 1 to 8, the organic solvent for dissolving or dispersing the resin includes aliphatic alcohols such as methanol, ethanol and propanol, n-hexane, cyclohexane, heptane, octane, nonane, decane and the like. Hydrocarbons, diacetone alcohol, 3-methoxy-1-butanol, acetone, methyl ethyl ketone, cyclohexanone, ethylene glycol, diethylene glycol, ethylene glycol monoacetate, ethylene glycol alkyl ethers and their acetates (methyl cellosolve, ethyl cellosolve, butyl cellosolve, Ethylene glycol dimethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate), diethylene glycol monoalkyl ethers and their acetates (Diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate), diethylene glycol dialkyl ethers (diethylene glycol dimethyl ether,
Diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether), triethylene glycol alkyl ethers (monomethyl ether, monoethyl ether, dimethyl ether, diethyl ether, methyl ethyl ether), propylene glycol alkyl ethers and their acetates (monomethyl ether, Monoethyl ether, n-propyl ether, monobutyl ether, co, etriether, diethyl ether, monomethyl ether acetate, monoethyl ether acetate), dipropylene glycol alkyl ethers (monomethyl ether, monoethyl ether, n-propyl ether, mono Butyl ether, dimethyl ether, diethyl ether), Ethyl, propyl formate, butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, carboxylic acid esters such as ethyl propionate, methyl butyrate, ethyl butyrate, dimethyl formamide, dimethyl sulfoxide,
Dioxane, tetrahydrofuran, methyl lactate, ethyl lactate, methyl benzoate, ethyl benzoate, propylene carbonate and the like.

The preferred organic solvent for the resin to be fixed to the surface of the photosensitive layer is the one according to the first to third aspects of the present invention.
The invention according to claims 4 to 8 has a boiling point of 10 to 200 ° C.
It is an organic solvent of 0 to 200 ° C.

Preferred organic solvents for the resin in the invention according to claims 1 to 3 include ethanol, isopropyl alcohol, ethyl acetate, methyl ethyl ketone, dimethyl diglycol dimethyl ether, diethyl diglycol dimethyl ether, methyl carbitol, ethyl carbitol and methoxy ethanol. Ethoxyethanol, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, butyl cellosolve, and Solfit (manufactured by Claire Soprene Chemical).

Preferred examples of the organic solvent for the resin in the invention according to claims 4 to 8 include dimethyl diglycol dimethyl ether, diethyl diglycol dimethyl ether, methyl carbitol, ethyl carbitol, methoxyethanol, ethoxyethanol, propylene glycol and propylene glycol monomethyl. Ether, propylene glycol monoethyl ether, ethyl lactate,
Butyl cellosolve, Solfit (manufactured by Kuraray Soprene Chemical) and the like can be mentioned.

These solvents can be used alone or in combination of two or more. The organic solvent has a boiling point of 100 to 200.
C. is preferred, and the concentration of the resin is preferably 10 to 50% by weight, more preferably 10 to 30% by weight in the invention according to claims 1 to 3, and the invention according to claims 4 to 6 is Preferably 5 to 40% by weight, more preferably 5 to 20% by weight, the invention according to claim 7 or 8, preferably 5 to 40% by weight, more preferably 10 to 40% by weight.
Range.

The solution or dispersion of the resin is sprayed onto the surface of the photosensitive layer, formed into fine particles, adhered, dried, and fixed on the surface in an uneven manner. As a method of spraying, known methods such as an air spray method, an airless spray method, an electrostatic air spray method, an electrostatic atomization electrostatic coating method, and the like can be adopted. As a preferred method of spraying, a method in which a resin solution is dropped on a cup or a disk rotating at a high speed (10,000 to 100,000 rpm) to form fine particles, and the spread and flight distance are controlled by electrostatic and air flow (electrostatic Atomized spray).

The drying step of the fine particles formed by spraying the resin solution or dispersion preferably includes a drying step substantially after the fine particles adhere to the surface of the photosensitive layer. Drying can be carried out by a usual method, for example, a method of blowing hot air, but usually drying can be carried out for several seconds even at about room temperature.

In the inventions according to the first to eighth aspects, the unevenness due to the resin fixed on the surface of the photosensitive layer is such that individual fine particles generated by spraying a liquid in which the resin is dissolved or dispersed in an organic solvent are exposed to the surface of the photosensitive layer. It is preferable that the minute individual resin coating layers formed by adhering and drying at intervals are formed in discontinuous dots.
Known sizes can be applied to the size and the number per unit area of the resin coating layer. As a preferred embodiment of the fine individual resin coating layer, the diameter (the length of the longest diagonal line when not circular) is preferably 1 to 200 μm,
More preferably 5 to 100 μm, still more preferably 5 to 100 μm
20 μm, and the height of the projection is preferably 1 to 50 μm, more preferably 1 to 20 μm, and still more preferably 1 to 20 μm.
５5 μm, and the number per unit area is preferably 1 to 1000, more preferably 5 to 10 per 1 mm ^2.
There are zero.

In the first aspect of the present invention, the "main component of the photosensitive layer" is a component relating to the solubility of the photosensitive layer in a developing solution. In the case of a sensitive layer developed with an aqueous alkali solution, the alkali solubility of the sensitive layer is substantially determined by the binder resin, and thus the main component of the sensitive layer is the binder resin contained in the sensitive layer.

In a preferred embodiment of the present invention, the photosensitive layer is a compound in which an o-quinonediazide compound is esterified with a polycondensate of phenol and / or polyhydric phenol as a photosensitive component, and phenol and / or a binder resin as a binder resin. Or an embodiment containing a polycondensate of polyhydric phenol, and the physical properties of the resin to be fixed to the surface of the photosensitive layer and the main component of the photosensitive layer are different, in order to imagewise expose and develop the imagewise exposed photosensitive layer. An embodiment in which the compound is soluble in a liquid used, for example, an aqueous alkaline solution (preferably having a pH of 10 to 12) may be mentioned.

Next, the invention according to claims 4 to 6 will be described.

The second object of the present invention is to provide a photosensitive layer on a support, spray a liquid obtained by dissolving or dispersing a resin in an organic solvent on the surface of the photosensitive layer, and adhere the sprayed fine particles to the surface. In a photosensitive lithographic printing plate in which the resin is fixed to the surface of the photosensitive layer in an uneven manner by drying, the unevenness has a trapezoidal cross section and a bottom diameter of 5 to 3 mm.
Achieved by a photosensitive lithographic printing plate that is 0 μm.

The resin adhered to the surface of the photosensitive layer has a trapezoidal cross section (longitudinal cross section) and a bottom surface (surface in contact with the photosensitive layer) having a diameter of 5 to 30 μm. The oblique side and the upper bottom side of the trapezoidal shape need not be straight lines.

As a method of matting the photosensitive lithographic printing plate, a solution in which a resin is dissolved or dispersed in an organic solvent is sprayed, and the sprayed fine particles sufficiently flow even in a state of being adhered to the surface of the photosensitive layer. To fix the resin on the surface of the photosensitive layer. Here, "sufficiently flows" means that the sprayed fine particles sufficiently flow even in a state of being adhered to the surface of the photosensitive layer, so that the irregularities of the resin fixed to the surface of the photosensitive layer in an uneven manner. Means that the cross section and the diameter of the bottom surface thereof flow to the extent that the above conditions are satisfied. As another method, there is a method in which a liquid in which the resin is dissolved or dispersed in an organic solvent has a solid content concentration of 5 to 20%, and a solvent having a boiling point of 100 to 200 ° C is used as the organic solvent.

Next, the invention according to claim 7 or 8 will be described.

The second object of the present invention is to provide a photosensitive layer on a support, spray a liquid obtained by dissolving or dispersing a resin in an organic solvent on the surface of the photosensitive layer, and adhere the sprayed fine particles to the surface. In a photosensitive lithographic printing plate in which the resin is fixed to the surface of the photosensitive layer in an uneven manner by drying, the height of the unevenness is 1 to 5 μm, and the average particle size is 5 to 2 μm.
This is also achieved with a photosensitive lithographic printing plate that is 0 μm.

As a preferred embodiment, there is an embodiment in which a liquid in which a resin is dissolved or dispersed in an organic solvent has a solid content concentration of 10 to 40%, and the boiling point of the organic solvent is 100 to 200 ° C.

[0050]

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, Comparative Examples 1 and 2 (Examples and Comparative Examples of the Inventions According to Claims 1 to 3) Preparation of Support A 0.24 mm-thick aluminum plate was placed in a 5% aqueous sodium hydroxide solution. After the degreasing treatment, 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 having the following composition was coated on the support and dried to form a photosensitive layer (sample A).

Photosensitive solution Novolak resin (1) (the molar ratio of phenol / m-cresol / p-cresol / is 10/54/36, weight average molecular weight 5000) 7.5 parts with pyrogallol acetone resin (weight average molecular weight 2000) Condensation product of o-naphthoquinonediazide-5-sulfonyl chloride (esterification rate 30%) 2.5 parts Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.08 parts 2,4-bis (trichloromethyl) -6 -(P-methoxystyryl) -s-triazine 0.10 parts Methyl ethyl ketone / propylene glycol monomethyl ether (50/50 volume ratio) 100 parts On the surface of the photosensitive layer of the sample A, 3 of the composition shown in Table 1 below
Each of the resin solutions was sprayed using an electrostatic spray gun, dried, fixed, and matted to prepare photosensitive lithographic printing plates 1 to 3. The conditions for the electrostatic spraying were a voltage of 4 kV and a rotation speed of 20,000.

Resin solution 1 (photosensitive lithographic printing plate 1) Polymer 1 80 parts of styrene / acrylic acid (40/60 in molar ratio, Mw 100000) ethanol / propylene glycol monomethyl ether (10/90 in volume ratio) 20 parts Resin solution 2 (photosensitive lithographic printing plate 2) 80 parts of the novolak resin (1) 80 parts ethanol / propylene glycol monomethyl ether (10/90 by volume ratio) 20 parts Resin solution 3 (photosensitive lithographic printing plate 3) 80 parts of polymer 2 (methyl Methacrylate / butyl acrylate / sodium acrylate (70/20/10 in molar ratio, Mw 100000)) Ethanol / propylene glycol monomethyl ether (10/90 in volume ratio) 20 parts The above resin fixed on the surface of the photosensitive layer and the photosensitive layer The difference in physical properties from the main components of The solubility in sex solution, pH of the resin 0.5g was ground into particles having an average particle diameter of 2~3mm
11 was immersed in 30 ml of an aqueous NaOH solution for 5 seconds, and the degree of dissolution was evaluated.

Photosensitive lithographic printing plate 1 Polymer 1: Completely dissolved Photosensitive lithographic printing plate 2 Novolak resin (1): Undissolved Photosensitive lithographic printing plate 3 Polymer 2: Completely dissolved Formed on photosensitive layer surface The application amount of the resin, the number of resin layers (mat particles) formed on the photosensitive layer surface per unit area, the height, and the diameter were as follows.

Number of resin layers: 15 / mm ² Height of resin layer: 4 μm Diameter of resin layer: 10 μm The above-mentioned photosensitive lithographic printing plate was evaluated for alkali solubility, vacuum adhesion time and quality of printed matter by the following methods. Was evaluated.

Alkali solubility 0.5 g of the pulverized and atomized polymer was added to NaOH of pH 11
It was immersed in 30 ml of an aqueous solution for 5 seconds, and the degree of dissolution was evaluated. The meanings of the symbols in Table 1 below are as follows.

：: Completely soluble △: Slightly insoluble content remains ×: Not melted Vacuum adhesion time A 1000 mm × 800 mm sample and a 50% halftone dot chart (size: 900 mm × 600 mm) are set in an exposure machine. Vacuum adhesion was performed, and the time until adhesion was measured.

Quality of Printed Material The sample was image-exposed and printed with a Heidelberg GTO printing machine, and the quality of the solid portion of the obtained printed material was visually evaluated. The meanings of the symbols in Table 1 below are as follows.

：: good ×: many pinhole-shaped defects are visible

[0061]

[Table 1]

Examples 2 to 7 and Comparative Examples 3 and 4 (Examples and Comparative Examples of the Inventions According to Claims 4 to 6) On the surface of the photosensitive layer of the sample A, as a resin to be fixed to the surface of the photosensitive layer Styrene / butyl acrylate / methacrylic acid (20/40/40 in molar ratio, weight average molecular weight:
(200,000) in a solvent shown in Table 2 below at a concentration shown in Table 2 was sprayed using an electrostatic spray gun, dried and fixed to prepare a matt-processed photosensitive lithographic printing plate. The condition of the electrostatic spray is voltage 4
kV, the number of rotations was 40,000, and the distance from the spray nozzle to the surface of the photosensitive layer was about 40 cm. Table 2 below shows the cross-sectional shape of the matte particles of these photosensitive lithographic printing plates.

The above photosensitive lithographic printing plate has a weight of 30 kg /
The presence or absence of crushing of the mat particles when a load of m ² was applied was measured, and the vacuum adhesion time was evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[0064]

[Table 2]

Examples 8 to 12 and Comparative Examples 5 and 6 (Claim 7)
Or Examples and Comparative Examples of the invention according to 8) On the surface of the photosensitive layer of Sample A, methyl methacrylate / butyl acrylate / methacrylic acid (40/20/40 in molar ratio, as a resin to be fixed to the surface of the photosensitive layer) A weight average molecular weight: 200000) was dissolved in a solvent shown in Table 3 below at a concentration shown in Table 3 by spraying a polymer solution using an electrostatic spray gun, dried and fixed, and matt-processed photosensitive lithographic printing plate. It was created. The conditions of the electrostatic spraying were as follows: the voltage was 4 kV, the number of rotations was 40,000, and the distance from the spray nozzle to the surface of the photosensitive layer was about 40 cm. Table 3 shows the cross-sectional shape of the matte particles of these photosensitive lithographic printing plates.
Shown in

The above photosensitive lithographic printing plate has a weight of 30 kg /
The presence or absence of crushing of the mat particles when a load of m ² was applied was measured, and the vacuum adhesion time was evaluated in the same manner as in Example 1. The results are shown in Table 3 below.

[0067]

[Table 3]

[0068]

According to the present invention, there is provided a photosensitive lithographic printing plate wherein a matting agent is fixed on the surface of a photosensitive layer in order to obtain good adhesion in a short time in vacuum contact printing. Photosensitivity with sufficient adhesion to the surface of the photosensitive layer, no deterioration in vacuum adhesion due to dropping of the matting agent, and good printed matter with good ink adhesion (particularly uniform density of solid portion) A lithographic printing plate is provided. According to the invention according to claims 4 to 8, the matting agent is not crushed even by the pressure at the time of exposure by the vacuum adhesion method, the adhesion of the matting agent to the photosensitive layer surface is sufficient, and the vacuum adhesion is good. A lithographic printing plate is provided.

Claims (8)

[Claims] 1. A photosensitive layer is provided on a support, and a liquid obtained by dissolving or dispersing a resin in an organic solvent is sprayed on the surface of the photosensitive layer, followed by drying to fix the resin on the surface of the photosensitive layer in an uneven manner. A photosensitive lithographic printing plate, characterized in that the resin has different physical properties from the main components of the photosensitive layer. 2. The photosensitive lithographic printing plate according to claim 1, wherein the physical properties are solubility in an aqueous alkaline solution. 3. A main component of the photosensitive layer is a compound obtained by esterifying an o-quinonediazide compound with a polycondensate of phenol and / or polyhydric phenol, and cresol and / or
2. The photosensitive lithographic printing plate according to claim 1, which is a polycondensate of phenol. 4. A photosensitive layer is provided on a support, and a liquid obtained by dissolving or dispersing a resin in an organic solvent is sprayed on the surface of the photosensitive layer. The sprayed fine particles are adhered to the surface and dried to dry the resin. A photosensitive lithographic printing plate having an unevenly fixed surface on a photosensitive layer, wherein the unevenness has a trapezoidal cross section and a bottom diameter of 5 to 30 μm. . 5. The method for producing a photosensitive lithographic printing plate for producing a photosensitive lithographic printing plate according to claim 4, wherein the fine particles flow sufficiently even in a state where they adhere to the surface of the photosensitive layer. 6. A liquid in which the resin is dissolved or dispersed in an organic solvent, has a solid content of 5 to 20%, and a solvent having a boiling point of 100 to 200 ° C. is used as the organic solvent. 4. A method for producing a photosensitive lithographic printing plate for producing the photosensitive lithographic printing plate according to 4. 7. A photosensitive layer is provided on a support, the surface of which is sprayed with a liquid in which a resin is dissolved or dispersed in an organic solvent, and the sprayed fine particles are adhered to the surface and dried to remove the resin. A photosensitive lithographic printing plate having an uneven surface fixed on the surface of a photosensitive layer, wherein the height of the unevenness is 1 to 5 μm and the average particle size is 5 to 20 μm. Edition. 8. The photosensitive lithographic printing plate according to claim 7, wherein the liquid has a solid content of 10 to 40%, and the boiling point of the organic solvent is 100 to 200 ° C. A method for producing a photosensitive lithographic printing plate.