JPH07261401A - Printing plate material - Google Patents

Abstract

PURPOSE:To enhance close contact with an original image film at the time of exposure and to form an excellent grain without generating the deterioration of picture by providing a layer containing cross-linked polymer particles obtained by polymerizing specific polymerizing monomers. CONSTITUTION:This printing plate material is provided with a layer containing the cross-linked polymer particles obtained by polymerizing the polymerizable monomers containing >=10wt.% cross-linking monomers. Where, the printing plate material means one obtained by forming a photosensitive layer composed of an image forming material on a substrate and if necessary, forming a cover film on the photosensitive layer. And the cross-linked polymer particle is obtained by polymerizing the polymerizable monomers containing >=10wt.% cross-linking monomers having >=2 groups containing polymerizable double bonds in the molecule. And as the cross-linking monomer, a compound having a non-conjugate vinyl compound represented by divinyl benzene or a polyfunctional acrylate compound represented by trimethylenepropane trimethacrylate is exemplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing plate material for plate making by electrophotography or photographic method. More specifically, it relates to a printing plate material having fine printability, in which fine particles are contained in the constituent layers of the printing plate.

[0002]

2. Description of the Related Art Conventionally, when a printing plate material having a photosensitive layer formed on a substrate is exposed through an original image film such as a positive film or a negative film, in order to obtain a good image without burning blur, the photosensitive layer and the original image are It is necessary to remove the air between the films and bring them into close contact, and vacuuming is usually used to remove the air between the photosensitive layer and the original film.
It was done. However, when the photosensitive layer and the original image film are overlapped and vacuum-adhered, most of the surface is firmly fixed, but it is very difficult to remove the bubbles left between the photosensitive layer and the original image film. It was difficult. As a result, there is a problem in that the original image cannot be faithfully reproduced due to the occurrence of burning blur when exposed with insufficient adhesion between the photosensitive layer and the original image film. In order to solve this problem, Japanese Patent Publication No. 61-614 discloses that
A method has been proposed in which a solution containing inorganic particles is applied to a cover film to form unevenness on the surface to improve vacuum adhesion. Further, JP-A-2-63051 discloses that a cover film containing particles having an average particle diameter of 4 to 9 μm and a refractive index of 1.4 to 1.7 is provided. However, in the methods disclosed in JP-B-61-614 and JP-A-2-63051, the adhesion between the added particles and the binder resin of the cover film is insufficient, and the improvement of the baking blur is also insufficient. It was Also, in the production of lithographic printing plate precursors, the adhesion of the support and the film coated on it is improved, or the "fountain solution" in the non-image area during printing is improved and printing stains are improved. Or for the purpose of improving the ink receptivity of the image area, a fine uneven pattern (hereinafter simply referred to as “grain”) on the surface of the support or the surface of the applied lithographic printing layer.
Is said to be formed. JP-A-51-
According to Japanese Patent No. 13940, by incorporating fine particles into a support having a rough surface and a coating layer on the support, a mat effect due to the roughness of the surface of the support and a mat effect due to fine particle powder in the coating layer are combined. It has been proposed to obtain a good grain due to the matte effect. In addition, Japanese Patent Publication No. 51-157
No. 64 discloses that the composition of the undercoat layer of the printing plate has a particle size of 0.1.
A method of improving by incorporating fine particles of 10 to 10 μm has been proposed. However, even with these methods, the improvement in ink receptivity and background stain is not sufficient, and further improvements have been demanded.

[0003]

SUMMARY OF THE INVENTION The present invention has been made against the background of the above-mentioned conventional technical problems, and has excellent adhesion to the original image film during exposure, that is, the time required for vacuum adhesion is short and the productivity is excellent. It is also an object of the present invention to provide a printing plate material that does not cause image quality deterioration due to transfer of an original image film and can form better grain.

[0004]

According to the present invention, there is provided a printing plate having a layer containing crosslinked polymer particles obtained by polymerizing a polymerizable monomer containing 10% by weight or more of a crosslinking monomer. It provides the material. Less than,
The present invention will be described in detail. In the present invention, the printing plate material refers to a material in which a photosensitive layer made of an image forming material is formed on a substrate and, if necessary, a cover film is formed on the photosensitive layer. In the present invention, the crosslinked polymer particles are polymerized such that the content of the crosslinkable monomer having two or more groups having a polymerizable double bond in the molecule (hereinafter, simply referred to as “crosslinkable monomer”) is 10% by weight or more. Obtained by polymerizing a volatile monomer, and having an average particle diameter of 0.01 to 10 μm. Examples of the crosslinkable monomer include the following compounds having two or more copolymerizable double bonds such as a non-conjugated vinyl compound typified by divinylbenzene or a polyvalent acrylate compound typified by trimethylene propane trimethacrylate. , These are used by 1 type (s) or 2 or more types.

Specific examples of the crosslinkable monomer include polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-butylene glycol diacrylate, 1,6-hexanelen glycol diacrylate and neopentyl glycol diacrylate. ,
Polypropylene diacrylate, 2,2'-bis (4-
Acryloxyproproxyphenyl) propane, 2,
Diacrylate compounds such as 2'-bis (4-acryloxydiethoxyphenyl) propane, trimethylolpropane triacrylate, trimethylolethane triacrylate, triacrylate compounds such as tetramethylolmethane triacrylate, ditrimethylolpropane tetraacrylate, Tetramethylolmethane tetraacrylate, tetraacrylate compounds such as pentaerythritol tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
Polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2 ，
Examples thereof include methacrylate compounds such as 2-bis (4-methacryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethacrylate compounds such as trimethylolethanetrimethacrylate, methylenebisacrylamide, and divinylbenzene. Of the above, divinylbenzene, ethylene glycol dimethacrylate, or trimethylolpropane trimethacrylate is preferably used, and divinylbenzene is particularly preferable.

Among the polymerizable monomers other than the crosslinkable monomer, examples of the monomer having no functional group include the following compounds, which may be used alone or in combination of two or more.
Aromatic monovinyl compounds such as styrene, ethyl vinyl benzene, α-methyl styrene, fluorostyrene, vinyl pyridine, butyl acrylate, 2-ethylhexyl acrylate, β-methacryloyloxyethyl hydrogendiene phthalate, N, N′-dimethylaminoethyl acrylate, etc. Acrylic acid ester monomer,
2-ethylhexyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, N, N'-
Methacrylic acid ester monomers such as dimethylaminoethyl methacrylate, silicon-modified monomers, macromonomers, etc. Further, conjugated double bond compounds such as butadiene and isoprene, vinyl ester compounds such as vinyl acetate, 4-methyl-1-pentene and other α-olefin compounds can be mentioned. Further, as the monomer having a functional group among the polymerizable monomers other than the crosslinkable monomer, a mono- or dicarboxylic acid monomer such as acrylic acid, methacrylic acid, maleic acid or itaconic acid, 2-acryloyloxyethyl-2-hydroxyethylphthale acid,
Amido compounds such as 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, sodium styrenesulfonate, maleic anhydride, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, methylenebisamide, acrylonitrile, Examples thereof include vinyl cyanide compounds such as methacrylonitrile.

In the crosslinked polymer particles, the content of the crosslinkable monomer in the polymerizable monomer used is 10% by weight.
Or more, preferably 15% by weight or more, more preferably 2
It is 0% by weight or more. If the content of the crosslinkable monomer is less than 10% by weight, the improvement of the baking blur is insufficient or the printing durability is deteriorated. As a preferable combination of the polymerizable monomers constituting the crosslinkable polymer particles, a crosslinkable monomer such as a non-conjugated vinyl compound or a polyvalent methacrylate compound and an aromatic monovinyl compound, a polymerizable monomer such as an acrylic acid ester monomer or a methacrylic acid ester monomer is used. And a combination of a non-conjugated vinyl compound and an aromatic monovinyl compound is particularly preferable. In the present invention, the average particle diameter of the crosslinked polymer particles is 0.01 to 10 μm, preferably 0.01
˜5 μm, more preferably 0.01 to 2 μm.
If the average particle size is less than 0.1 μm, smoothness is poor, and if it exceeds 10 μm, printing durability is poor. The average particle diameter here is measured by the following method. The average particle diameter of the crosslinked polymer particles was measured by directly measuring 100 particles by a transmission electron micrograph (when the particles are not spherical, the long diameter and the short diameter were measured and the average value was obtained. ) Was carried out by obtaining the average value of. In the present invention, in order to further improve the affinity with the binder, the surface of the crosslinked polymer particles is partially covered with a polymer having a content of the crosslinkable monomer of less than 10% by weight (hereinafter referred to as “polymer B”). Alternatively, the entire surface may be covered to form composite crosslinked polymer particles. As the monomer for forming the polymer B, the same monomer as for forming the crosslinkable polymer particles can be used. The preferred glass transition temperature of the polymer (B) is 200 ° C. or lower, particularly 150 ° C. or lower.

The content of the crosslinkable monomer in the polymerizable monomer used in the polymer (B) is less than 10% by weight, preferably 8% by weight or less, more preferably 5% by weight or less. When the content of the crosslinkable monomer in the polymerizable monomers constituting the polymer (B) is 10% by weight or more, the affinity with the binder of the photosensitive layer or the cover film cannot be improved. The amount of the polymer (B) to be partially or entirely laminated on the surface of the crosslinked polymer particles is 100% of the crosslinked polymer particles.
0.01 to 900 parts by weight, preferably 0.1 to 400 parts by weight, and more preferably 0.5 to 20 parts by weight.
0 parts by weight. When the amount of the polymer (B) is less than 0.01 part by weight, the affinity for the binder of the photosensitive layer or the cover film is poor. Further, the polymer (B) is a group having chemical reactivity or ionicity in the molecule and has a functional group (hereinafter, simply referred to as “functional group”) excluding a group containing a polymerizable double bond. In that case, the affinity with the binder of the photosensitive layer or the cover film is further excellent. Here, examples of the functional group include a reactive functional group such as a carboxyl group, a hydroxyl group, an N-methylol group, a sulfone group, a maleic anhydride unit, an epoxy group, an amino group, an amide group, and a nitrile group. Preferred functional groups are carboxyl group, hydroxyl group, amino group and amide group. In the present invention, the functional group-containing monomer is used in an amount of 0.05 to 20% by weight, particularly 0.1 to 20% by weight based on the monomers constituting the polymer (B).
It is preferable that the content of 15% by weight improves the affinity with the binder of the composite crosslinked polymer particles obtained.

Specific monomers having a functional group include the same ones as described above. Polymer B
Among the polymerizable monomers other than the above-mentioned crosslinkable monomer, preferred as the monomer for constituting are aromatic vinyl, acrylic acid ester, methacrylic acid ester, monomers having a functional group, specifically, styrene and ethyl. Vinylbenzene, acrylonitrile, methyl methacrylate, butyl acrylate, (meth) acrylic acid and the like. It is also possible to impart a functional group to the above polymer (B) by chemical treatment, for example, by obtaining a polymer (B) having an epoxy group and then treating with ammonia, methylamine or the like. An amino group can be added or a sulfone group can be added by treatment with sodium hydrogen sulfite or sulfuric acid. Further, as a preferable combination of the polymerizable monomers constituting the polymer (B), a non-conjugated vinyl compound, a crosslinkable monomer such as a polyvalent methacrylate compound and an aromatic monovinyl compound, an acrylic acid ester monomer, a methacrylic acid ester monomer, etc. A combination of a polymerizable monomer and a monomer containing a functional group can be mentioned, and a combination of a non-conjugated vinyl compound, an aromatic monovinyl compound and a di- or monocarboxylic acid is particularly preferable. In the present invention, a polymerizable monomer having a content of the crosslinkable monomer of 10% by weight or more is polymerized, preferably by an emulsion polymerization method to obtain crosslinked polymer particles. The composite crosslinkable polymer particles have a crosslinkable monomer content of less than 10% by weight, and preferably a functional group-containing monomer content of 0.1% by weight in the presence of 100 weight parts of the crosslinked polymer particles (A). 0.01 to 900 parts by weight of the polymerizable monomer of 05 to 20% by weight is preferably polymerized by the emulsion polymerization method. In the present invention, partially coating the surface of the crosslinked polymer particles with the polymer (B) means that less than 100% of the total surface area of the crosslinked polymer particles, preferably 0.00001% or more and less than 100% of the polymer ( It shows that it coats with B).

The method of adding the polymerizable monomer in the polymerization to obtain the above-mentioned crosslinked polymer particles and composite crosslinked polymer particles is preferably a method of continuously or intermittently adding a part or the whole amount. The polymerization initiator used in the above emulsion polymerization is not particularly limited as long as it is used in ordinary emulsion polymerization and suspension polymerization, but potassium persulfate, sodium persulfate, persulfate salts such as ammonium persulfate are used. The initiator, azo-based initiator, hydrogen peroxide, organic peroxide and the like may be used alone or in combination with various reducing agents such as ascorbic acid. In the above emulsion polymerization, in order to enhance the stability of the polymerization reaction system,
Suspension protectants or surfactants are used. Usual surfactants can be used, for example, dodecylbenzene sulfonate, dodecyl sulfate, lauryl sulfate, dialkylsulfosuccinate, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene alkylpropenylphenyl. Examples thereof include anionic surfactants such as ether sulfates and formalin condensates of naphthalene sulfonic acid. Here, sodium, ammonium, potassium, etc. can be mentioned as a salt. Furthermore, it is also possible to use nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyethylene glycol monostearate, polyoxyethylene alkylpropenyl phenyl ether, sorbitan monostearate. Further, it is possible to use a generally known reactive emulsifier such as sodium naphthalenesulfonate alone or in combination with the above-mentioned surfactant. As a preferable suspension protector, water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethyl cellulose, sodium polyacrylate, and hydroxypropyl cellulose can be used. These may be used alone or in combination. A preferable combination is a combination of an anionic surfactant, a nonionic surfactant and a water-soluble polymer. In the present invention,
In using the crosslinked polymer particles, the known organic polymer particles and inorganic particles are 40% by weight or less, preferably 20% by weight or less.
It is also possible to use together not more than 10% by weight, more preferably not more than 10% by weight. Examples of the organic polymer particles that can be used in combination include polystyrene particles, polymethylmethacrylate particles, polybenzoguanamine particles, epoxy particles, and corn starch. Examples of the inorganic particles that can be used in combination include natural silica, calcium carbonate, synthetic silica and mica.

In the present invention, as the substrate of the printing plate material, metal such as zinc, copper and magnesium alloy, stone, plastic, paper and the like are used, and are appropriately selected depending on the kind of printing. The photosensitive layer is composed of a mixture of a natural or synthetic colloid and a photosensitizer, a photosensitive polymer, or the like. Natural or synthetic colloids include starch, casein,
Albumin, gum arabic, hydroxyethyl cellulose, gelatin, etc., sensitizers such as silver halides, dichromates, diazo compounds, azide compounds, etc., and photosensitive polymers containing or copolymerizing sensitizers Polyester, polyamide, polyvinyl alcohol,
Silicone rubber etc. can be mentioned. Further, the cover film that can be used in the present invention needs to be transparent to the exposing light, and a known transparent plastic film can be used. Examples thereof include polyethylene terephthalate, polypropylene, polyvinylidene chloride, polyvinyl chloride, polyamide, polyurethane, polystyrene, cellophane, polyvinyl alcohol, and cellulose acetate. The thickness of the cover film is 0.1-20μ
m is preferable, and more preferably 1 to 15 μm. Further, when the polymer solution in which the polymer binder and the crosslinked polymer particles are mixed is applied to the cover film, it is preferable to use a method of increasing the adhesion by corona discharge treatment or flame treatment of the film surface. In the present invention, an undercoat layer or an adhesive layer may be provided between the substrate and the photosensitive layer and between the photosensitive layer and the cover film, if necessary.

In the printing plate material of the present invention, in order to form a layer containing the above crosslinked polymer particles, the crosslinked polymer particles are added to the photosensitive layer, a film containing the crosslinked polymer is laminated on the photosensitive layer or crosslinked. By forming a crosslinked polymer layer by applying a dispersion containing polymer particles, adding crosslinked polymer particles to a cover film, laminating a film containing a crosslinked polymer on the cover film, or a solution containing a crosslinked polymer Any method such as forming a crosslinked polymer layer by coating may be applied, and these methods can be combined, but from the viewpoint of productivity and quality of the manufacturing process, and the methods are used alone or in combination. It is preferable to use.

First, when the crosslinked polymer particles are added to the photosensitive layer, the crosslinked polymer particles can be added to any layer such as the photosensitizer layer, the undercoat layer and the intermediate layer in the photosensitive layer. The amount of the crosslinked polymer particles added is generally 0.5 to 50% by weight, preferably 1 to 40% by weight, based on the natural or synthetic colloid. Further, in the above method or method, the film containing the crosslinked polymer particles can be obtained by adding the crosslinked polymer particles into a polymer film which forms the cover film. Further, the solution containing the crosslinked polymer particles is a solution in which the crosslinked crosslinked polymer particles are dispersed with a polymer having a film-forming property as a binder. Here, as the film-forming polymer, crystalline and amorphous saturated polyester resins, unsaturated polyester resins, thermosetting polyurethane resins, thermoplastic polyurethane resins, melamine resins, urea resins, acrylic resins, alkyd resins , Chlorinated polyolefin resins and the like. It is also possible to use a cross-linking crosslinking agent in combination with the polymer binder. Examples of the cross-linking agent include polyfunctional isocyanate cross-linking agents, polyfunctional epoxy cross-linking agents, amino resin cross-linking agents, etc., which are appropriately selected and used according to the polymer binder to be used.

The addition ratio of the crosslinked polymer particles to the binder in the polymer film or polymer dispersion is usually 0.01% by weight to 20% by weight, preferably 0.1% by weight to 10% by weight. The coating amount of the polymer solution is 10 g / m ² or less, preferably 4 g / m ² or less in dry thickness. Although the lower limit of the coating amount is not limited, it is preferably 0.1 g / m ² or more from the viewpoint of coatability. The difference in refractive index between the crosslinked polymer particles, the polymer film and the polymer binder used in the present invention is not particularly limited, but it is 0.
It is preferably 3 or less. The polymer layer containing the crosslinked polymer particles obtained by the above method or may also serve as a cover film. next,
The proportion of the crosslinked polymer particles added to the cover film is usually 0.01 to 20% by weight of the cover film, and preferably 0.1. It is 1 to 10% by weight. The printing plate material of the present invention can be effectively applied to a relief printing plate, a planographic printing plate, a waterless planographic printing plate, a dry film resist, a direct printing plate, an electrophotographic planographic printing plate, a flexographic printing plate and the like. As the original image film that can be used together with the printing plate material of the present invention, both a normal positive film and a negative film can be used.

[0015]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited thereto. In the following description, "part" means "part by weight" and "%" means "% by weight". Measurement method of particle size The average particle size of the composite crosslinked polymer particles is measured by measuring the particle size of 100 particles directly by a transmission electron micrograph (if the particles are not spherical, measure the major axis and the minor axis) The average value was calculated.).

[0016] to obtain crosslinked polymer particles a~e by the following preparation examples of crosslinked polymer particle Production Example 1] to [Production Example 5]. [Production Example 1] Divinylbenzene (commercial item, purity 55%,
The remaining 40% is ethyl vinyl benzene, the remaining 5% is diethylbenzene) 50 parts, styrene 50 parts, sodium dodecylbenzene sulfonate 5 parts, polyvinyl alcohol 0.5 part, ion-exchanged water 1000 parts, α, α′-azo 1 part of isobutyronitrile was charged into a reaction vessel, and homogenized with a homomixer at 12,000 rpm for 60 minutes. Then, while blowing nitrogen gas, the mixture was heated to 80 ° C. and continuously stirred for 3 hours to carry out suspension polymerization to obtain an average particle size of 1.
Polymer fine particles a of 9 μm were obtained. [Production Example 2] 10 parts of polymethylmethacrylate particles having a weight average molecular weight of 15,000 and an average particle diameter of 0.25 μm, sodium dodecylbenzenesulfonate 5
Parts, 30 parts of ethylene glycol dimethacrylate (commercial product, purity 99%), 70 parts of methyl methacrylate, 1 part of sodium persulfate, 700 parts of ion-exchanged water are charged into a reaction vessel and nitrogen gas is blown thereinto at 80 ° C. for 1 hour while stirring Polymerization was performed to obtain polymer fine particles b having an average particle diameter of 0.5 μm. [Production Example 3] 50 parts of divinylbenzene (purity and the like is the same as in Production Example 1), 50 parts of styrene, 5 parts of sodium dodecylbenzenesulfonate, 0.5 parts of polyvinyl alcohol,
1000 parts of ion-exchanged water and 1 part of α, α′-azoisobutyronitrile were charged into a reaction vessel, and the mixture was mixed with a homomixer to 1
The mixture was stirred at 2,000 rpm for 60 minutes to make it uniform. Then, while blowing nitrogen gas, the mixture was heated to 80 ° C. and continuously stirred for 3 hours to carry out polymerization. Then, as a second step, 1 part of potassium persulfate was charged into the reaction vessel, and 70 parts of methyl methacrylate and 20 parts of n-butyl acrylate were added.
An emulsion prepared by mixing 9 parts of methacrylic acid, 1 part of ethylene glycol methacrylate, 40 parts of ion-exchanged water, 0.5 part of dodecylbenzenesulfonic acid, and 1 part of polyvinyl alcohol was continuously added for 3 hours to complete the polymerization, and the average. Polymer fine particles c having a particle diameter of 2.3 μm were produced.

[Production Example 4] The weight average molecular weight is 15,000.
10 parts of polystyrene particles having an average particle size of 0 and 0.25 μm, sodium dodecylbenzenesulfonate 5
Part, divinylbenzene (purity etc. are the same as in Production Example 1) 65
Parts, styrene 35 parts, sodium persulfate 1 part, and ion-exchanged water 700 parts were charged into a reaction vessel and polymerized at 80 ° C. for 1 hour under stirring while blowing nitrogen gas. After that, in the second step, 1 part of styrene, 1 part of methacrylic acid, 0.5 part of 2-hydroxyethyl methacrylate and 0.5 part of sodium persulfate were added, and the mixture was polymerized at 80 ° C. for 3 hours to complete the polymerization. Polymer fine particles d having a particle diameter of 0.6 μm were produced. [Production Example 5] 100 parts of methyl methacrylate, 3 parts of sodium dodecylbenzenesulfonate, 0.5 part of polyvinyl alcohol, 1000 parts of ion-exchanged water, 1 part of α, α'-azoisobutyronitrile were charged into a reaction vessel, and homogenized. The mixture was agitated with a mixer at 15,000 rpm for 60 minutes for homogenization. Then, while blowing nitrogen gas, the mixture was heated to 80 ° C. and continuously stirred for 3 hours to carry out suspension polymerization to obtain polymer fine particles e having an average particle diameter of 1.9 μm.

Examples 1 to 4 Waterless lithographic printing plates were prepared using the polymer fine particles a to d by the following method, and an exposure test was conducted. The results are shown in Table 1.
Shown in. (1) Preparation of cover film Polyurethane (Samplen SZ18 manufactured by Sanyo Kasei Co., Ltd.) 10
0 part, polymer fine particles 8 parts, dimethylformamide 45
A coating solution was prepared by mixing 0 parts and 450 parts of methyl ethyl ketone. This coating solution was applied to a polyethylene terephthalate film (8 μm) and dried at 100 ° C. for 30 seconds. The thickness of the coating layer after drying was 1 g / m ² , and the amount of particles added was 0.07 g / m ² . (2) Preparation of waterless planographic printing plate and measurement of adhesion time The above cover film was laminated so as to be in contact with the silicone rubber layer of Toray waterless planographic TAP to prepare a waterless planographic printing original plate. Using a vacuum baking frame (TYPE P-802G manufactured by Dainippon Screen Mfg. Co., Ltd.), a positive film (was adhered to this printing plate precursor and the time required was measured. (3) Evaluation in exposure and development Using automatic processor (Toray TWL860K)
Was exposed and developed, and the presence or absence of burning blur was visually determined.

Comparative Examples 1-2 Fine particles e and fine particles f (silica particles Mizukasil P-8 manufactured by Mizusawa Chemical Industry Co., Ltd.) were used instead of the fine particles used in Examples 1 to 4.
Evaluation was made in the same manner except that 02) was used. The results are shown in Table 1.
Shown in.

[0020]

[Table 1]

Example 5 An antihalation undercoat containing a matting layer containing fine particles b on one side of an undercoated polyester film support and carbon black on the opposite side in an amount to give a light reflectance of 5%. A layer and a spectrally amplified high-sensitivity silver chloride emulsion layer were provided thereon. Fine particles b (1.2 g /
m ² ) was mixed with gelatin (3 g / m ² ), and the emulsion layer was coated with gelatin (1.5 g / m ² ) and silver halide (1.5 g / m ² ) in terms of silver nitrate. The undercoat layer and the emulsifier layer contain formalin as a hardening agent (5 mg / 1 g of gelatin). After drying, after heating at 40 ° C. for 14 days, a coating solution (comprising ion-exchange resin-treated palladium sulfide sol / hydroquinone / saponin / water) was applied onto this emulsion layer and dried to form a lithographic printing plate. Manufactured. The silver halide emulsion has a silver halide composition of 1 during physical ripening.
The average particle size was 0.45 μm, in which 5 × 10 ⁻⁶ mol of rhodium chloride was added per mol. Chemical sensitization
It was carried out with 3 × 10 ⁻⁵ mol of sodium thiosulfate and 4 × 10 ⁻⁵ mol of HAuCl ₄ per mol of silver halide. The spectral sensitizing dye was 3 × 10 ⁻⁴ per mol of silver halide.
Molar cyanine dye was used. A 200-line / inch contact screen (manufactured by Dainippon Screen) was closely adhered to the printing plate prepared above and exposed (Direct Scanner Graph SG-606 manufactured by Dainippon Screen).
After exposure, after developing with a transfer developer and treating with a neutralizing solution,
It was dried at room temperature. The lithographic printing plate thus obtained was used for printing and the following evaluations were carried out. Ink sticking property : Paper feeding was started at the same time when an inking roller was brought into contact with the plate surface, and the number of prints until a printed matter was obtained with good image density was evaluated. ◯ Obtained on 10 or less sheets, × 20 or more background stains required: 5000 sheets were printed, and the degree of stain on the printed matter at that time was evaluated. ○ No stains occurred at all × Dense stains on the entire surface Printing durability : Evaluated by the number of prints until a good image printout is no longer a good printout due to image jump, image density drop or image collapse did. ◎ 5000 or more good prints, ○ 4000 or more 50
Table 2 shows the good results when the number of sheets is 00 or less.

Example 6 In Example 5, fine particles c were used instead of fine particles b in the undercoat layer.
A lithographic printing plate was produced and evaluated in the same manner as in Example 5 except that was added. The results are shown in Table 2. Comparative Example 3 In Example 5, fine particles f were used in the undercoat layer instead of fine particles b.
A lithographic printing plate was produced and evaluated in the same manner as in Example 5 except that was added. The results are shown in Table 2.

[0024]

[Table 2]

[0025]

The present invention has been made against the background of the above-mentioned conventional technical problems. When applied to a cover film, it is excellent in vacuum adhesion to an original image film at the time of exposure, and image quality is deteriorated by transfer of an uneven pattern. When applied to the photosensitive layer of a lithographic printing plate, a good grain having excellent ink receptivity, little background stain and excellent printing durability could be formed.

Claims (1)

[Claims] 1. A printing plate material having a layer containing crosslinked polymer particles obtained by polymerizing a polymerizable monomer having a content of a crosslinkable monomer of 10% by weight or more.