JPH06332155A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To provide a photosensitive planographic printing plate not generating problems of grazing on a photosensitive layer and joining at a photosensitive layer when many sheets of it are conveyed and stored one over lapping the other, even in the case that slip sheet enabling to be regenerated is not used as insertion paper. CONSTITUTION:In the photosensitive planographic printing plate, the photosensitive layer and a mat layer in which the average diameter is 10-100Xm, the average height being 1-10 Xm and the coating quantity is 5-200mg/m<2> are successively provided on a surface of a supporting body and also a back coating layer with 0.01-8.0Xm thick incorporating an organic high polymer compound <=20 deg.C in the glass transition point and a surfactant is provided on the rear side of the supporting body.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive lithographic printing plate, and more particularly to a photosensitive lithographic printing plate provided with a back coat layer containing an organic polymer on the back surface of a support.

[0002]

2. Description of the Related Art A positive-working photosensitive lithographic printing plate which has been widely used in the past comprises a light-sensitive layer comprising an o-quinonediazide compound on an aluminum plate as a support. It is known that an o-quinonediazide compound is converted to a carboxylic acid by exposure to ultraviolet light, and therefore, when this is developed with an aqueous alkaline solution, only the exposed portion of the photosensitive layer is removed and the surface of the support is exposed.
Since the surface of the aluminum support is hydrophilic, the portion where the surface of the support is exposed by development (non-image area) retains water and repels the oil-based ink. On the other hand, the area (image area) where the photosensitive layer has not been removed by the development is lipophilic and thus repels water and accepts ink.

On the other hand, a negative type photosensitive lithographic printing plate is composed of a photosensitive layer made of a photosensitive diazonium salt on a support, a photosensitive layer made of a photopolymerizable monomer, and a polymer compound containing a cinnamic acid or a dimethylmaleimide group. Those provided with a photocrosslinkable photosensitive layer are known. The exposed areas of these photosensitive layers are cured, and only the unexposed areas are removed with an appropriate developing solution, and the same is used as a printing plate. When a large number of these photosensitive lithographic printing plates are piled up and conveyed, there is a problem that the photosensitive layer is scratched and scratched. As one of the causes of this, a photosensitive layer provided with a matte layer on which a matte layer for preventing vacuum blurring and shortening of vacuuming time during contact exposure using a vacuum baking frame, and a superposed layer thereon are stacked. It is considered that the other photosensitive lithographic printing plate thus obtained had insufficient slipperiness with the back surface of the aluminum support, and therefore was rubbed during transportation and scratched on the photosensitive layer. Further, when a large number of sheets are stored in piles, there is a problem in that the back surface of the support and the photosensitive layer of the photosensitive lithographic printing plate under the support are not adhered to each other due to the load and cannot be peeled off.

In order to solve these problems, it has been generally practiced to insert a sandwich paper called interleaving paper for each photosensitive lithographic printing plate. These interleaving papers are generally used with polyethylene or the like laminated on one side or both sides in consideration of the influence on the photosensitive layer. However, these interleaving papers cannot be used as recycled paper and are When a large amount of planographic printing plates are used, a new problem arises in that a large amount of interleaving paper is discharged as industrial waste. In order to improve this problem, it has been considered to use paper not laminated with a polymer such as polyethylene as an interleaving paper. However, the photosensitive layer of the photosensitive lithographic printing plate and the photosensitive lithographic printing layer overlaid thereon The slipperiness of the plate with respect to the back surface of the support is deteriorated, and the photosensitive layer is scratched. As another method for preventing scratches on the photosensitive layer, a thickness of 10 to 100 μm which is easily peeled off on the photosensitive layer of the photosensitive lithographic printing plate or on the back surface of the support.
A technique for providing a protective layer of m is disclosed in JP-B-51-6570. This can eliminate scratches when handling photosensitive lithographic printing plates one after another, but adhesion between the photosensitive layer and the protective layer poses a new problem, and the peeled protective layer is industrially discarded as in the case of interleaving paper. There was a new problem of being discharged as a thing.

On the other hand, JP-A-50-151136 discloses a method of forming a soft polymer layer or paper layer on the back surface of a support, and JP-A-57-63293 discloses a steel sheet on the back surface of aluminum whose surface is grained. Method of providing a protective layer of a polymer having a melting point of 120 ° C. or lower on the steel plate side (opposite side of the photosensitive layer) of the laminated composite support, 60-7353.
No. 8 discloses a method of providing a protective layer on the back surface of a support, which is removed at the time of development, and JP-A No. 61-67863 discloses a photosensitive lithographic printing plate similarly provided with an organic polymer compound having a thickness of 100 μm or less on the back surface. Is disclosed. In these prior arts, it is stated that the thickness of the protective layer is preferably 100 μm or more, and a comparatively soft polymer is preferable because the emphasis is placed on overlapping cutting of the photosensitive lithographic printing plate, and in fact, it is 10 μm or more. The low density polyethylene protective layer of was effective for stack cutting. However, since the slipperiness between the photosensitive layer surface and the back surface of the aluminum support of the photosensitive lithographic printing plate laminated thereon is not considered, when a large number of sheets are stacked,
There was a problem that the photosensitive layer surface was scratched during transportation.

Further, depending on the type of the protective layer used, there have been problems such that the protective layer swells due to the chemicals used during printing, the printing pressure changes, and the printing durability deteriorates. This was because the protective layer was relatively thick, 10 μm or more.
JP-B-55-48296 discloses that the surface of the aluminum support is mechanically, chemically or electrochemically roughened, and a photosensitive layer is provided on the back surface of the aluminum support to provide a layer for absorbing infrared rays. A method of further heating (burning) is disclosed. However, this infrared absorbing layer uses pigments such as carbon black or hard particles such as fine metal powder as an infrared absorbing agent, and the slipperiness is not taken into consideration as in the above case, which damages the photosensitive layer. There was a problem.

[0007]

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide an improved photosensitive lithographic printing plate which does not suffer from scratches, even with reusable interleaving paper.
Another object of the present invention is to provide an improved photosensitive lithographic printing plate which does not have the problem of scratches and adhesion without the use of interleaving paper which becomes industrial waste.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a relatively hard layer of an organic polymer compound and a surfactant is thinly formed on the back surface of a support. It has been found that the above object can be achieved by providing a matte layer having a specific shape on the photosensitive layer,
The present invention has been accomplished. That is, the present invention has a photosensitive layer on the surface of a support, an average diameter of 10 to 100 μm, an average height of 1 to 10 μm, and a coating amount of 5 to 200 mg / m 2.
And a matte layer comprised of ² provided, and the glass transition point to the back surface of the support is provided with a backcoat layer having a thickness of 0.01~8.0μm containing an organic polymer compound described above 20 ° C. and a surfactant The present invention relates to a photosensitive lithographic printing plate characterized by the above. Below, the photosensitive lithographic printing plate of the present invention (hereinafter referred to as PS plate)
Will be described in detail.

[0009]

[Support] The support used in the PS plate of the present invention is a dimensionally stable plate. As such a support, paper,
Paper laminated with plastics (eg polyethylene, polypropylene, polystyrene, etc.), eg aluminum (including aluminum alloys), zinc,
A metal plate such as iron or copper is used, but the effect of the present invention is remarkably exhibited especially on a metal plate such as an aluminum plate. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a slight amount of a foreign element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper,
Examples include magnesium, chromium, zinc, bismuth, nickel and titanium. The content of foreign elements in the alloy is at most 10% by weight. Aluminum suitable for the present invention is pure aluminum, but completely pure aluminum is difficult to produce due to refining technology, and thus may contain slightly different elements. As described above, the aluminum plate applied to the present invention is not limited in its composition, and conventionally known publicly known materials can be appropriately used.
The thickness of the aluminum plate used in the present invention is 0.1 mm to
It is about 0.6 mm.

Prior to roughening the surface of the aluminum plate, if desired, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is carried out in order to remove the rolling oil on the surface. First, the surface of the aluminum plate may be roughened, and as a method thereof, a method of mechanically roughening the surface, a method of electrochemically melting and roughening the surface, or a method of selectively melting the surface chemically There are ways. Mechanical methods include ball polishing, brush polishing, blast polishing,
A known method called a buff polishing method can be used. Further, as an electrochemical graining method, there is a method of performing alternating current or direct current in a hydrochloric acid or nitric acid electrolytic solution. Further, as disclosed in Japanese Patent Application Laid-Open No. 54-63902, a method in which both are combined can be used.
The thus roughened aluminum plate is subjected to an alkali etching treatment and a neutralization treatment, if necessary, and then subjected to anodization treatment if desired to enhance the water retention and abrasion resistance of the surface. As the electrolyte used for anodizing the aluminum plate, any electrolyte that forms a porous oxide film can be used, and generally sulfuric acid, phosphoric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.

The anodizing condition varies depending on the electrolyte used and cannot be specified unconditionally. Generally, however, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 5. 60 A / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are suitable. The amount of the anodized film is preferably 1.0 g / m ² or more, more preferably
It is in the range of 2.0 to 6.0 g / m ² . Anodized film 1.0g
If it is less than / m ² , the printing durability is insufficient, or the non-image area of the planographic printing plate is easily scratched, and so-called “scratch stains” tend to occur in which ink is attached to the scratched portion during printing. . After being subjected to anodizing treatment, the aluminum surface is optionally subjected to hydrophilic treatment. Examples of the hydrophilic treatment used in the present invention include U.S. Pat. Nos. 2,714,066 and 3,18.
There are alkali metal silicate (eg aqueous sodium silicate) processes such as those disclosed in 1,461, 3,280,734 and 3,902,734. In this method, the support is dipped or electrolyzed in an aqueous sodium silicate solution. In addition, Japanese Patent Publication Sho 36-22
No. 063 and potassium fluorozirconate disclosed in US Pat. Nos. 3,276,868, 4,153,461 and US Pat.
For example, a method of treating with polyvinylphosphonic acid as disclosed in 4,689,272 is used.

[0012]

[Organic Undercoat Layer] An organic undercoat layer is provided on a support such as an aluminum plate, if necessary, before coating the photosensitive layer.
Examples of the organic compound used in this organic undercoat layer include phosphonic acids having an amino group such as carboxymethyl cellulose, dextrin, gum arabic, and 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, and naphthyl. Phosphonic acid, alkylphosphonic acid Glycerophosphonic acid, organic phosphonic acid such as methylenediphosphonic acid or ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, organic phosphoric acid such as alkylphosphoric acid or glycerophosphoric acid Acids, phenylphosphinic acid which may have a substituent, naphthylphosphinic acid, organic phosphinic acids such as alkylphosphinic acid or glycerophosphinic acid, amino acids such as glycine and β-alanine, and triethanolamine hydrochloride Have a hydroxyl group -Alanine and the like amine hydrochloride, may be used as a mixture of two or more thereof.

This organic undercoat layer can be provided by the following method. That is, water or methanol, ethanol,
A method in which a solution prepared by dissolving the above organic compound in an organic solvent such as methyl ethyl ketone or a mixed solvent thereof is applied on a support and dried, and an organic solvent such as water or methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof. In this method, the support is immersed in a solution in which the organic compound is dissolved to adsorb the organic compound, and then washed with water or the like and dried to form an organic undercoat layer. In the former method, 0.
A solution having a concentration of 005 to 10% by weight can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, or curtain coating may be used.
In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, and the immersion temperature is 2%.
The temperature is 0 to 90 ° C., preferably 25 to 50 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute.

The solution used as the undercoat layer is ammonia,
Adjust the pH with basic substances such as triethylamine and potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid to adjust the pH.
It can also be used in the range of 1 to 12. Further, a yellow dye may be added to improve the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the organic undercoat layer after drying is 2 to
200 mg / m ² is suitable, preferably 5-100 mg /
m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same applies when the amount is larger than 200 mg / m ² .

[0015]

[Backcoat layer] On the back surface of the support of the PS plate of the present invention,
In order to prevent scratches on the photosensitive layer when sandwiching slip-resistant slip sheets such as pure pulp, and to prevent scratches and sticking on the photosensitive layer even when piled up without interleaving paper, organic polymer compounds and surface active agents are used. A back coat layer containing an agent is provided. As a material for the back coat layer which characterizes the present invention, an organic polymer compound having a glass transition point of 20 ° C. or higher, preferably 30 ° C. or higher, and preferably insoluble in water and an alkaline developer having a pH of 8.5 or higher is used. An organic polymer compound having a glass transition point of lower than 20 ° C. is not preferable because adhesion with the photosensitive layer occurs. Examples of the organic polymer compound include polybutene, polybutadiene, saturated polyester resin, unsaturated polyester resin, nylon, polyurethane, polyurea, polyimide, polysiloxane, polycarbonate, epoxy resin, phenoxy resin, chlorinated polyethylene, and aldehyde condensation resin of alkylphenol. Suitable are acetal resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, acrylic resin or copolymer resin thereof, hydroxy cellulose, polyvinyl alcohol, cellulose acetate, carboxymethyl cellulose and the like. The glass transition point of these organic polymer compounds is adjusted to 20 ° C. or higher by selecting the degree of polymerization or a partner to be copolymerized or by curing with a suitable crosslinking agent.

Other suitable backcoat layer materials include copolymers having the following monomers (1) to (12) as constituent units and having a molecular weight of usually 10,000 to 200,000. Similarly, the glass transition point can be adjusted to a desired value by selecting the degree of polymerization and the copolymerization monomer. (1) Acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester and hydroxystyrene having an aromatic hydroxyl group, such as N- (4-
Hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide, o-, m- and p-hydroxystyrene, o-, m- and p-hydroxyphenyl acrylate or methacrylate, (2) an acrylic group having an aliphatic hydroxyl group. Acid esters and methacrylic acid esters, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate,
(3) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, acrylic (Substituted) acrylic acid ester such as acid 4-hydroxybutyl, glycidyl acrylate, N-dimethylaminoethyl acrylate,

(4) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
Amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, methacrylic acid 2
-Chloroethyl, 4-hydroxybutyl methacrylate,
(Substituted) methacrylic acid esters such as glycidyl methacrylate and N-dimethylaminoethyl methacrylate,
(5) Acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-hexylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide,
N-cyclohexylmethacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenyl Methacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-
Acrylamide or methacrylamide such as N-phenylmethacrylamide,

(6) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether, (7) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate, (8) styrenes such as styrene, methyl styrene and chloromethyl styrene, ( 9)
Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone, (10) olefins such as ethylene, propylene, isobutylene, butadiene and isoprene, (11) N
-Vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc. (12) N- (o-aminosulfonylphenyl)
Acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-aminosulfonyl) naphthyl] acrylamide, N- (2-aminosulfonylethyl) acrylamide, etc. Acrylamides, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1- (3-aminosulfonyl) )
Naphthyl] methacrylamide, methacrylamides such as N- (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m-
Unsaturated sulfonamides such as acrylic acid esters such as aminosulfonylphenyl acrylate, p-aminosulfonylphenyl acrylate, 1- (3-aminosulfonylphenylnaphthyl) acrylate,

O-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate,
p-aminosulfonylphenyl methacrylate, 1-
Unsaturated sulfonamides such as methacrylic acid esters such as (3-aminosulfonylphenylnaphthyl) methacrylate. Further, a monomer copolymerizable with the above-mentioned monomer may be copolymerized. Further, a copolymer obtained by copolymerizing the above-mentioned monomers is also modified, for example, with glycidyl acrylate, glycidyl methacrylate, etc., but is not limited thereto. Based on the weight of the back coat layer, the organic polymer compound has a content of 9
It is used in an amount of 0 to 9.999%, preferably 95 to 99.99%. The backcoat layer of the present invention further contains a surfactant. This is added for the purpose of improving the slipperiness with respect to the interleaving paper or the photosensitive layer, the prevention of sticking to the matte layer, the coated surface state and the like. Examples of the surfactant include anionic, cationic, nonionic and amphoteric surfactants.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial ester. , Sorbitan fatty acid partial esters,
Pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester , Polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial ester, fatty acid diethanolamide,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, and trialkylamine oxides,

Fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts,
Dialkylsulfosuccinate ester salts, linear alkylbenzene sulfonates, branched chain alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl- N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfuric acid ester salts of fatty acid alkyl esters, alkyl sulfuric acid ester salts, polyoxyethylene alkyl ether sulfuric acid ester salts, Fatty acid monoglyceride sulfate ester salts, polyoxyethylene alkylphenyl ether sulfate ester salts, polyoxyethylene styryl phenyl ether sulfate ester salts, Ruquil phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkylphenyl ether phosphate ester salts, partial saponification products of styrene / maleic anhydride copolymers, olefin / maleic anhydride copolymers Anionic surfactants such as saponified products and naphthalene sulfonate formalin condensates, alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, cationic surfactants such as polyethylene polyamine derivatives, carboxybetaine And amphoteric surfactants such as aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. Among the above-mentioned surfactants, those having polyoxyethylene can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene and polyoxybutylene, and these surfactants are also included.

A particularly preferred surfactant is a fluorinated surfactant containing a perfluoroalkyl group in the molecule. Such fluorine-based surfactants include perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, anionic systems such as perfluoroalkyl phosphates, amphoteric systems such as perfluoroalkyl betaines, and perfluoroalkyl trimethyl ammonium salts. Cation-based and perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct,
An oligomer containing a perfluoroalkyl group and a hydrophilic group,
An oligomer containing a perfluoroalkyl group and a lipophilic group,
Nonionic compounds such as perfluoroalkyl group-, hydrophilic group- and lipophilic group-containing oligomers, perfluoroalkyl group- and lipophilic group-containing urethanes can be mentioned. Further, the fluorine-containing surfactants described in JP-A Nos. 62-170950, 62-226143 and 60-168144 are also preferably used. The above-mentioned surfactants can be used alone or in combination of two or more kinds, and 0.0001-10% by weight, preferably 0.01
Is added in the range of ~ 5% by weight.

If desired, a plasticizer may be added to the back coat layer used in the present invention for the purpose of imparting flexibility or adjusting slipperiness. Preferred plasticizers include, for example, phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butylbenzyl phthalate, diisodecyl phthalate, diallyl phthalate, and the like, Dimethyl glycol phthalate, ethyl phthalyl ethyl glycolate,
Methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, glycol esters such as triethylene glycol dicaprylate, phosphates such as tricresyl phosphate, triphenyl phosphate, diisobutyl adipate, dioctyl adipate, dimethyl sebacate , Aliphatic dibasic acid esters such as dibutyl sebacate, dioctyl azelate and dibutyl maleate, polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate and the like are effective. The plasticizer is added in a range such that the glass transition point of the back coat layer does not fall below 20 ° C., and it can be contained up to about 30% by weight based on the organic polymer compound used for the back coat layer. The backcoat layer used in the present invention further comprises a dye or pigment for coloring, a silane coupling agent for improving adhesion with an aluminum support, a diazo resin containing a diazonium salt, an organic phosphonic acid, an organic phosphoric acid. Waxes, higher fatty acids, higher fatty acid amides, etc.
A silicone compound made of dimethyl siloxane, modified dimethyl siloxane, polyethylene powder and the like are appropriately added.

The thickness of the back coat layer used in the present invention is basically a thickness that does not damage the photosensitive layer without interleaving paper,
That is, it is 0.01 to 8.0 μm, preferably 0.02 to 6.
It is 0 μm. If the thickness is less than 0.01 μm, scratches on the photosensitive layer cannot be prevented when the PS plates are stacked and handled. If the thickness exceeds 8.0 μm, the back coat layer may be dissolved or swelled by the chemicals used around the printing during printing to change the thickness, and the printing pressure may be changed to deteriorate the printing characteristics. Various methods can be applied to coat the back coat layer on the back surface of a support such as an aluminum plate. For example, a method of applying a solution in a suitable solvent, or applying an emulsion dispersion, coating and drying, for example, a method of pasting a preformed film into a support with an adhesive or heat,
Examples of the method include forming a melted film with a melt extruder and laminating it on a support. The most preferable method for securing the coating amount is to form a solution and then coat and dry. Examples of the solvent used here include JP-A-62-25173.
Organic solvents such as those described in Japanese Patent Publication No. 9 are used alone or in combination.

[0025]

[Photosensitive layer] A photosensitive layer made of a known photosensitive composition is provided on the surface of the support. As the photosensitive composition, o-
Positive type mainly composed of quinonediazide compound, diazonium salt, alkali-soluble diazonium salt, photopolymerizable compound mainly composed of unsaturated double bond-containing monomer, and photocrosslinkable compound containing cinnamic acid or dimethylmaleimide group A negative type photosensitive material is used.

[0026]

[Positive-type photosensitive layer] As an o-naphthoquinonediazide compound used as a positive-type photosensitive composition, Japanese Patent Publication No.
The ester of 1,2-diazonaphthoquinonesulfonic acid and pyrogallol-acetone resin described in JP-A-3-28403 is preferable. Other suitable orthoquinonediazide compounds include, for example, U.S. Pat.
No. 1 and No. 3,188,210
-Diazonaphthoquinone-5-sulfonic acid and phenol-
There is an ester with a formaldehyde resin.
There are esters of 1,2-diazonaphthoquinone-4-sulfonic acid and a phenol-formaldehyde resin described in JP-A 96163, JP-A-2-96165 and JP-A-2-96761. Other useful o-naphthoquinonediazide compounds include those known in numerous patents and the like. For example, JP-A-47-
No. 5303, No. 48-63802, No. 48-6380
3, No. 48-96575, No. 49-38701,
48-13854, 37-18015, 41-11222, 45-9610 and 49-1.
7481, U.S. Pat. Nos. 2,797,213 and 3,45
No. 4,400, No. 3,544,323, No. 3,573,917, No.
3,674,495, 3,785,825, British Patent 1,227,60
No. 2, No. 1,251,345, No. 1,267,005, No. 1,32
Mention may be made of those described in each publication such as 9,888, 1,330,932 and German Patent No. 854,890 or in the specification.

The o-naphthoquinonediazide compound particularly preferred in the present invention is a compound obtained by reacting a polyhydroxy compound having a molecular weight of 1,000 or less with 1,2-diazonaphthoquinonesulfonic acid. Specific examples of such compounds are described in JP-A-51-139402 and JP-A-5-139402.
8-150948, 58-203434, 59
-165053, 60-12145, 60-
134235, 60-163043, 61-1
No. 18744, No. 62-10645, No. 62-106.
No. 46, No. 62-153950, No. 62-17856.
No. 2, 64-76047, U.S. Pat. No. 3,102,809.
No. 3, No. 3,126,281, No. 3,130,047, No. 3,14
No. 8,983, No. 3,184,310, No. 3,188,210, No.
The materials described in each publication or specification such as 4,639,406 can be mentioned.

When synthesizing these o-naphthoquinonediazide compounds, it is preferable to react 0.2-1.2 equivalents of 1,2-diazonaphthoquinonesulfonic acid chloride with the hydroxyl group of the polyhydroxy compound. .3
More preferably, the reaction is carried out at about 1.0 equivalent. Examples of 1,2-diazonaphthoquinonesulfonic acid chloride include 1,2
-Diazonaphthoquinone-5-sulfonic acid chloride or 1,2-diazonaphthoquinone-4-sulfonic acid chloride can be used. The obtained o-naphthoquinonediazide compound is a mixture of 1,2-diazonaphthoquinonesulfonic acid ester groups having different positions and introduction amounts, but all of the hydroxyl groups are 1,2-diazonaphthoquinonesulfonic acid esterified. The compound
The proportion (content of the completely esterified compound) in this mixture is preferably 5 mol% or more,
More preferably, it is 20 to 99 mol%.

The amount of the photosensitive compound acting on the positive type (including the above-mentioned combination) in the photosensitive composition is suitably 10 to 50% by weight, preferably 15 to 40% by weight. Is. The o-quinonediazide compound alone can form the photosensitive layer, but it is preferable to use a resin soluble in alkaline water together as a binder. As such a resin soluble in alkaline water, there is a novolak type resin such as phenol formaldehyde resin, o-, m- and p-cresol formaldehyde resin, m / p-mixed cresol formaldehyde resin, phenol / cresol ( o-, m-, p
-, M / p-, and o / m-mixture may be used) mixed formaldehyde resin and the like.

Further, a phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, and an acrylic resin containing a phenolic hydroxyl group as disclosed in JP-A-51-34711 can also be used. Other suitable binders include copolymers having the following monomers (1) to (13) as constituent units and having a molecular weight of usually 10,000 to 200,000. (1) Acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester and hydroxystyrene having an aromatic hydroxyl group, such as N- (4-
Hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide, o-, m- and p-hydroxystyrene, o-, m- and p-hydroxyphenyl acrylate or methacrylate, (2)
Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate,
(3) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, methaconic acid,

(4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, 2-acrylate Chloroethyl, 4-hydroxybutyl acrylate, glycidyl acrylate,
(Substitution) such as N-dimethylaminoethyl acrylate
Acrylic ester, (5) methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate,
Cyclohexyl methacrylate, octyl methacrylate,
(Substituted) methacrylic acid esters such as phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl methacrylate, (6) acrylamide, methacrylamide, N
-Methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-hexylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-cyclohexylmethacrylamide, N-hydroxyethylacrylamide, N -Hydroxyethyl acrylamide, N-phenyl acrylamide, N-phenyl methacrylamide, N-benzyl acrylamide,
N-benzyl methacrylamide, N-nitrophenyl acrylamide, N-nitrophenyl methacrylamide,
Acrylamide or methacrylamide such as N-ethyl-N-phenylacrylamide or N-ethyl-N-phenylmethacrylamide,

(7) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether, (8) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate, (9) styrenes such as styrene, methylstyrene and chloromethylstyrene, ( 1
0) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone, (11) olefins such as ethylene, propylene, isobutylene, butadiene and isoprene, (1)
2) N-vinylpyrrolidone, N-vinylcarbazole,
4-Vinylpyridine, acrylonitrile, methacrylonitrile, etc., (13) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- Acrylamides such as [1- (3-aminosulfonyl) naphthyl] acrylamide and N- (2-aminosulfonylethyl) acrylamide,

N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1- (3-aminosulfonyl) Naphthyl] methacrylamide, methacrylamides such as N- (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl acrylate, p
-Aminosulfonylphenyl acrylate, 1- (3-
Unsaturated sulfonamides such as acrylic acid esters such as aminosulfonylphenylnaphthyl) acrylate,
Unsaturated sulfonamides such as methacrylic acid esters such as o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate and 1- (3-aminosulfonylphenylnaphthyl) methacrylate.

Further, a monomer copolymerizable with the above-mentioned monomer may be copolymerized. Further, a copolymer obtained by copolymerizing the above-mentioned monomers is also modified, for example, with glycidyl acrylate, glycidyl methacrylate, etc., but is not limited thereto. The above copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the preferable acid value of the copolymer is 0.
It is -10 meq / g, more preferably 0.2-5.0 meq / g. The preferred molecular weight of the above copolymer is 10,000 to 100,000. Moreover, you may add polyvinyl butyral resin, polyurethane resin, polyamide resin, or an epoxy resin to the said copolymer as needed. Such alkali-soluble polymer compounds may be used alone or in combination of two or more and are used in an amount of 80% by weight or less of the photosensitive layer.

Further, as described in US Pat. No. 4,123,279, a phenol-formaldehyde resin containing an alkyl group having 3 to 8 carbon atoms as a substituent, such as t-butylphenolformaldehyde resin and octylphenolformaldehyde resin, is used. It is preferable to use a condensate together in order to improve the oil sensitivity of the image. Cyclic acid anhydrides, phenols, and organic acids are preferably added to the photosensitive layer in the invention in order to enhance sensitivity. Examples of cyclic acid anhydrides are phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-entoxy-Δ ⁴ -tetrahydrophthalic anhydride and tetrachlorophthalic anhydride described in U.S. Pat. No. 4,115,128. , Maleic anhydride, chloromaleic anhydride, α-phenyl maleic anhydride, succinic anhydride, pyromellitic dianhydride, etc. can be used.

Examples of phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol,
2,4,4'-trihydroxybenzophenone, 2,
3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ', 4 "-trihydroxy-
Triphenylmethane, 4,4 ', 3 ", 4"-tetrahydroxy-3,5,3',5'-tetramethyltriphenylmethane and the like can be mentioned. Examples of organic acids include sulfonic acids, sulfinic acids, which are described in JP-A-60-88942 and JP-A-2-96755.
There are alkylsulfuric acids, phosphonic acids, phosphoric acid esters, carboxylic acids, and the like, and specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethylsulfuric acid, phenylphosphonic acid, phenylphosphinic acid. , Phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 1,4-cyclohexene-2,2-dicarboxylic acid, Examples thereof include erucic acid, lauric acid, n-undecanoic acid and ascorbic acid.

The proportion of the above cyclic acid anhydrides, phenols or organic acids in the photosensitive layer is 0.05 to 15% by weight.
Is preferable, and more preferably 0.1 to 5% by weight. Further, in the photosensitive layer according to the present invention, in order to broaden the stability of processing to the developing conditions (so-called development latitude),
Nonionic surfactants as described in JP-A-62-251740 and Japanese Patent Application No. 2-188.
JP-A-59-121044 and JP-A-4-1314
Amphoteric surfactants such as those described in No. 9 can be added.

Specific examples of the nonionic surfactant include:
Sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene sorbitan monooleate,
And polyoxyethylene nonylphenyl ether. Specific examples of the amphoteric surfactant include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N.
-Tetradecyl-N, N-betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and alkyl imidazoline type (for example, trade name Levon 15, Sanyo Kasei Co., Ltd.)
Manufactured) and the like.

The proportion of the nonionic surfactant or amphoteric surfactant in the photosensitive layer is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight. A printout agent for obtaining a visible image immediately after exposure and a dye or pigment as an image colorant may be added to the above-mentioned photosensitive composition. Typical examples of the printout agent include a combination of a compound that releases an acid upon exposure (photoacid releasing agent) and an organic dye capable of forming a salt. Specifically, o-naphthoquinonediazide-4 described in JP-A Nos. 50-36209 and 53-8128 are disclosed.
-A combination of a sulfonic acid halogenide and a salt-forming organic dye, and JP-A-53-36223 and 54-74728.
No. 60-3626, No. 61-143748, No. 61-151644, and No. 63-58440, combinations of trihalomethyl compounds and salt-forming organic dyes can be mentioned. . Such trihalomethyl compounds include oxazole compounds and triazine compounds, both of which have excellent stability over time,
Gives a clear printout.

As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS,
Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (above, manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine. B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI5201)
5) etc. can be mentioned. In addition, JP-A-62-2
The dyes described in Japanese Patent No. 93247 are particularly preferable. The photosensitive layer used in the PS plate of the present invention is applied to the surface of a support by dissolving it in a solvent that dissolves each of the above components.
As the solvent used here, methyl alcohol, ethyl alcohol, acetone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether,
Organic solvents described in JP-A-62-251739 such as N, N-dimethylformamide and dimethylsulfoxide may be used alone or in combination. The photosensitive composition is dissolved and dispersed at a solid content concentration of 2 to 50% by weight, and then coated and dried on a support.

The coating amount of the photosensitive layer coated on the support varies depending on the use, but generally, the weight after drying is 0.
It is preferably ³ to 4.0 g / m ² . The smaller the coating amount, the smaller the exposure amount for obtaining an image, but the film strength decreases. As the coating amount increases, the exposure amount is required, but the film strength increases. For example, when used as a printing plate, a printing plate having a high printable number (high printing durability) can be obtained. A surfactant for improving the quality of the coated surface, for example, a fluorinated surfactant as described in JP-A-62-170950 can be added to the photosensitive layer. The preferable addition amount is 0.001-1.
It is 0% by weight, preferably 0.005-0.5% by weight.

[0042]

[Negative-type photosensitive layer] Examples of the negative-type photosensitive layer that can be used in the PS plate of the present invention include a photosensitive layer containing a photosensitive diazo compound, a photopolymerizable photosensitive layer, and a photocrosslinkable photosensitive layer. The photo-curable photosensitive layer made of a photosensitive diazo compound will be described with reference to examples. The photosensitive diazo compound used in the PS plate of the present invention includes a diazo resin obtained by condensing an aromatic diazonium salt and a reactive carbonyl group-containing organic condensing agent, particularly aldehydes such as formaldehyde and acetaldehyde, or acetals in an acidic medium. Is preferably used. The most typical one is a condensate of p-diazophenylamine and formaldehyde. Methods for synthesizing these diazo resins are described, for example, in US Pat. No. 2,679,498.
No. 3, No. 3,050,502, No. 3,311,605 and No.
It is described in the specification of 3,277,074.

Further, as the photosensitive diazo compound, a co-condensation diazo compound of an aromatic diazonium salt described in JP-B-49-48,001 and a substituted aromatic compound containing no diazonium group is preferably used, and among them, A co-condensed diazo compound with an aromatic compound substituted with an alkali-soluble group such as a carboxyl group or a hydroxyl group is preferable. Furthermore,
Also a photosensitive diazo compound obtained by condensing an aromatic diazonium salt with a reactive carbonyl compound having an alkali-soluble group described in Japanese Patent Application Nos. 1-130,493, 2-321,823 and 2-299,551. It is preferably used.
As a counter anion of these diazonium salts, there are diazo resins using inorganic anions such as mineral acids such as hydrochloric acid, hydrobromic acid, sulfuric acid and phosphoric acid, or double salts with zinc chloride, but they are substantially water-insoluble and organic. Solvent-soluble diazo resins are particularly preferred. Such a preferable diazo resin is disclosed in JP-B-47-
1167, U.S. Pat. No. 3,300,309 or the specification thereof.

Further, JP-A Nos. 54-98613 and 56.
A diazo resin having a counter anion of halogenated Lewis acid such as tetrafluoroboric acid and hexafluorophosphoric acid and perhalogen acid such as perchloric acid and periodic acid as described in JP-A-121031 is preferably used. To be Further, JP-A-58-209733 and 62-17573.
The diazo resins having a long-chain alkyl group-containing sulfonic acid as a counter anion, which are described in JP-A Nos. 1 and 63-262643, are also preferably used.

The photosensitive diazo compound is contained in the photosensitive layer in an amount of 5 to 50.
It is contained in the range of 8 to 20% by weight, preferably 8 to 20% by weight. The photosensitive diazo compound is preferably used in combination with a lipophilic polymer compound which is soluble or swellable in alkaline water as a binder. Such a lipophilic polymer compound is usually 10,000 to 20 having the same monomer as shown in the above (1) to (13) as the constitutional unit, which is the same as that used in the positive photosensitive composition described above. Copolymers having a molecular weight of 10,000 can be mentioned.
Polymer compounds obtained by copolymerizing the monomers shown in 4) and (15) as constituent units can also be used. (14) Maleimide, N-acryloyl acrylamide, N-acetyl acrylamide, N-propionyl acrylamide, N-
Unsaturated imides such as (p-chlorobenzoyl) acrylamide, N-acetylacrylamide, N-acryloylmethacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide, (15). N- [2-
Unsaturation having a crosslinkable group in the side chain of (acryloyloxy) -ethyl] -2,3-dimethylmaleimide, N- [2- (methacryloyloxy) -ethyl] -2,3-dimethylmaleimide, vinylcinnamate, etc. monomer.

Further, a monomer copolymerizable with the above-mentioned monomer may be copolymerized. Further, a copolymer obtained by copolymerizing the above-mentioned monomers is also modified, for example, with glycidyl acrylate or glycidyl methacrylate, but is not limited thereto. The above copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the preferable acid value of the copolymer is 0 to 10 meq /
g, and more preferably 0.2 to 5.0 meq / g. The preferred molecular weight of the above copolymer is 10,000 to 100,000. Also,
If necessary, polyvinyl butyral resin, polyurethane resin, polyamide resin and epoxy resin may be added to the above copolymer. In addition, novolac type resin, phenol-modified xylene resin, polyhydroxystyrene,
Polyhalogenated hydroxystyrene, JP-A-51-34
It is also possible to use an alkali-soluble resin containing a phenolic hydroxyl group as disclosed in Japanese Patent No. 711.

Such alkali-soluble polymer compounds may be used alone or in combination of two or more,
It is usually contained in the solid content of the photosensitive layer in the range of 40 to 95% by weight. The photosensitive layer that can be used in the PS plate of the present invention includes
In order to improve the oil sensitivity of the image, an oil sensitizer (for example,
Half-esterified product of styrene-maleic anhydride copolymer with alcohol described in JP-A-55-527.
Novolac resin, 50% fatty acid ester of p-hydroxystyrene, etc.) may be added. Further, a plasticizer for imparting flexibility and abrasion resistance to the coating film may be added.
For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid. Examples thereof include acid oligomers and polymers, of which tricresyl phosphate is particularly preferable.

In order to extend the stability over time, the above-mentioned photosensitive layer is made of, for example, phosphoric acid, phosphorous acid, citric acid, oxalic acid, dipicolinic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, 4-methoxy. 2-Hydroxybenzophenone-5-sulfonic acid, tartaric acid, etc. may be added. Further, a printing-out agent for obtaining a visible image immediately after exposure or a dye such as a dye or a pigment as an image colorant can be added to the photosensitive layer. As the dye, those that change color tone by reacting with free radicals or acids are preferably used. For example, Victoria Pure Blue BOH (Hodogaya Chemical), Oil Yellow # 10
1, oil yellow # 103, oil pink # 312,
Oil Red, Oil Green BG, Oil Blue BO
S, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (above, manufactured by Orient Chemical Industry Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), Crystal Violet (CI
42555), methyl violet (CI4253
5), ethyl violet, rhodamine B (CI145
170B), malachite green (CI42000),
Methylene blue (CI52015),

Brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4-p-diethylaminophenyliminaphthoquinone, cyano-p-diethylaminophenylacetanilide, and other triphenylmethane-based and diphenylmethane-based compounds. , Oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based, or anthraquinone-based dyes change from colored to colorless or to different colored tones. On the other hand, as a discoloring agent that changes from colorless to colored, a leuco dye and, for example,
Triphenylamine, diphenylamine, o-chloroaniline, 1,2,3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p'-bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p, p ', p ″ -tris-dimethylaminotriphenylmethane, p, p′-bis-dimethylaminodiphenylmethylimine, p, p ′, p ″ -triamino-o-methyltriphenylmethane, p, p′-bis-dimethylamino Examples thereof include primary or secondary arylamine dyes represented by diphenyl-4-anilinonaphthylmethane and p, p ′, p ″ -triaminotriphenylmethane.

Particularly preferred are triphenylmethane and diphenylmethane dyes, more preferred is triphenylmethane dye, and especially Victoria Pure Blue BOH. The above dye is usually used in the photosensitive layer in an amount of about 0.5-10.
%, Preferably about 1-5% by weight. Cyclic acid anhydrides, phenols, organic acids or higher alcohols can be added to the photosensitive layer in order to enhance the developability. The photosensitive layer is dissolved in a solvent that dissolves each of the above components and applied onto an aluminum plate of a support. Examples of the solvent used here include JP-A-62-251739.
Organic solvents such as those described in Japanese Patent Laid-Open Publication can be used alone or in combination.

The photosensitive layer is dissolved and dispersed at a solid content concentration of 2 to 50% by weight, coated on a support and dried. The coating amount of the photosensitive layer coated on the support varies depending on the use, but it is generally 0.3 to 4.0 g / m ^{2 in} terms of weight after drying.
Is preferred. The smaller the coating amount, the smaller the exposure amount for obtaining an image, but the film strength decreases. As the coating amount increases, the exposure amount is required, but the film strength increases. For example, when used as a printing plate, a printing plate having a high printable number (high printing durability) can be obtained. A surfactant for improving the coated surface quality can be added to the photosensitive layer, as in the positive photosensitive composition described above. In the production of the PS plate of the present invention, either the back coat layer on the back side or the photosensitive layer on the front side may be coated on the support first, or both may be coated simultaneously.

[0052]

[Matte layer] On the surface of the photosensitive layer provided as described above, the vacuuming time during contact exposure using a vacuum baking frame is shortened to prevent burning blurring, and the photosensitive layer A mat layer is provided in order to prevent the PS plate laminated on the PS plate from adhering to the back coat layer. Specifically, JP-A-5
0-125805, Japanese Patent Publication No. 57-6582, 61
No. 28986, a method of providing a mat layer as described in JP-B No. 28986, and a method of heat-fusing a solid powder as described in JP-B No. 62-62337 are mentioned. The above effect becomes more remarkable in the PS plate having a water-soluble, alkaline-water-developer-soluble matte layer.

As the resin used in such a method, from the viewpoint of being strongly fixed to the photosensitive layer and hardness, a copolymer containing the following monomer units (a), (b) and (c) is added. The combination is particularly good. (A) At least one monomer unit selected from the group consisting of alkyl acrylates having 2 to 10 carbon atoms in the alkyl residue and alkyl methacrylates having 4 to 10 carbon atoms in the alkyl residue. . (B) At least one monomer unit selected from the group consisting of styrenes, acrylonitriles, methyl methacrylate and ethyl methacrylate. (C) Acrylic acid, methacrylic acid, maleic acid, itaconic acid, monomers having a sulfonic acid group, such as p-styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, ethylenesulfonic acid, alkali metal salts thereof, and At least one monomer unit selected from the group consisting of ammonium salts.

The above-mentioned monomer unit (a) is a component which imparts adhesiveness to the surface of the photosensitive layer, and specific examples thereof include 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, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-decyl methacrylate and the like are included. The monomer unit (b) is a component that imparts resistance to pressure, and specific examples thereof include styrene, o-methylstyrene, m-methylstyrene and p.
-Methylstyrene, 2,4-dimethylstyrene, 2,5
-Dimethylstyrene, 3,4-dimethylstyrene, 3,
5-dimethylstyrene, 2,4,5-trimethylstyrene, 2,4,6-trimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, 3,
5-diethylstyrene, 2,4,5-triethylstyrene, pn-butylstyrene, m-sec-butylstyrene, m-tert-butylstyrene, p-hexylstyrene, pn-heptylstyrene, p-2 -Ethylhexyl styrene, o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, o-chlorostyrene, m
-Chlorostyrene, 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-cyanostyrene, m-cyanostyrene, m-nitrostyrene, p-nitrostyrene, p-dimethylaminostyrene, Acrylonitrile, α-chloroacrylonitrile,
Examples include α-bromoacrylonitrile, α-trifluoromethylacrylonitrile, α-trifluoromethylcarboxyacrylonitrile, methyl methacrylate, ethyl methacrylate and the like. The monomer unit (c) is a component that improves the solubility in a developing solution, and specific examples thereof include acrylic acid, sodium acrylate,
Potassium acrylate, ammonium acrylate, methacrylic acid, sodium methacrylate, potassium methacrylate, ammonium methacrylate, maleic acid, sodium maleate, potassium maleate, ammonium maleate, itaconic acid, sodium itaconate, potassium itaconate, itacon Ammonium acid and the above-mentioned sulfonic acid-containing monomers and salts thereof are included.

In such a copolymer, the amount of the monomer units (a), (b) and (c) is 10 to 70, respectively.
Weight ranges of 20-80% and 6-50% are preferred. When the amount of the monomer unit (a) is less than 10% by weight, the adhesion of the copolymer to the surface of the photosensitive layer is decreased, while when it is more than 70% by weight, the pressure resistance of the copolymer is reduced. Is reduced. Further, as the amount of the monomer unit (b) is less than 20% by weight, the hardness of the copolymer is lowered and the pressure resistance is lowered, while when it is more than 80% by weight, Solubility in a developing solution is lowered and, moreover, adhesion to the photosensitive layer is lowered. Further, when the amount of the monomer unit (c) is less than 6% by weight, the solubility of the copolymer in the developing solution becomes poor, while when it is more than 50% by weight, the copolymer becomes brittle. The adhesion of the photosensitive layer to the surface is also reduced. Therefore, particularly preferred monomer units (a),
The amounts of (b) and (c) are respectively 15 to 50% by weight,
40 to 70% by weight and 10 to 25% by weight.

The above-mentioned copolymer is solution-polymerized in an organic solvent and evaporated to dryness to obtain a fine powder by a pulverizer, or acrylic acid or methacrylic acid of component (c), maleic acid, itaconic acid and A part of the sulfonic acid-containing monomer can be obtained as a sodium salt, potassium salt, or ammonium salt as an aqueous solution of the copolymer. Also, in the same manner as in the usual latex synthesis method, the raw material monomers may be emulsified in water with a surfactant and emulsion-polymerized using a polymerization initiator such as potassium persulfate to obtain an aqueous dispersion. Good. The copolymer may include a filler. Examples of the filler include silicon dioxide, zinc oxide, titanium oxide, zirconium oxide, glass particles, alumina, polymer particles (for example, particles of polymethylmethacrylate, polystyrene, phenol resin, etc.). These can be used in combination of two or more.

As a method for forming a mat layer by coating these resins, a method of fixing fine resin powder to the photosensitive layer by heat or a solvent (Japanese Patent Laid-Open No. 12975/1988), or dissolving or dissolving the resin A method in which the dispersed aqueous liquid is sprayed and dried (JP-A-57-34558).
However, from the viewpoints of safety, manufacturing stability, cost, etc., the matting method (air spray method, airless spray method, electrostatic air spray method, electrostatic fog method) described in JP-A-57-34558 is disclosed. Electrostatic atomization electrostatic coating method) is particularly preferable, and the electrostatic atomization electrostatic coating method having a high deposition rate is particularly preferable.

The average diameter of the mat layer used in the present invention is 1
It is from 0 to 100 μm, preferably from 20 to 80 μm. When the average diameter is smaller than 10 μm, the mat layer is easily crushed when PS plates are stacked, and vacuum adhesion becomes insufficient. On the other hand, when the average diameter of the PS plate is more than 100 μm, when the PS plate is overlaid and stored, the contact area between the photosensitive layer and the backcoat layer of the PS plate overlaid on the PS layer is increased, and the slipperiness is deteriorated. And the surface of both the back coat layer is apt to be scratched. The average height of the mat layer is 1 to 10 μm, preferably 2 to 8 μm. If the average height is lower than 1 μm, the vacuum adhesion becomes insufficient and baking blur is likely to occur. On the other hand, if the average height is higher than 10 μm, it is difficult to attach fine lines and the number of highlight dots is reduced, which is not preferable for tone reproduction. The coating amount of the matte layer is 5 to 200 mg / m ²
And preferably 20 to 150 mg / m ² . If the coating amount is more than 200 mg / m ² , the contact area between the photosensitive layer and the backcoat layer of the PS plate or the interleaving paper, which is overlaid thereon, increases, causing scratches. On the other hand, the application amount is 5 mg /
If it is smaller than m ² , the vacuum adhesion becomes insufficient. In the present invention, the slipperiness (tan θ) between the back coat layer and the slip sheet or the photosensitive layer is preferably 0.50 or less, and particularly preferably 0.43 or less. This slip property is evaluated as follows according to JIS P8147-1987. That is, a PS plate having a back coat layer on the back side is fixed with the back coat layer facing upward. On the other hand, 3
A smooth weight having an area of 5 mm × 75 mm and a weight of 200 g is prepared, and a slip sheet or a photosensitive layer (having a mat layer) is fixedly attached to the smooth flat surface of the weight. Then
A weight is placed on the fixed backcoat layer of the PS plate so that the interleaf paper or the photosensitive layer (with the mat layer on the opposite side of the weight) is in contact with the backcoat layer. The angle (θ) at the start of sliding is calculated, and tan θ is calculated from this angle. The smaller the slipperiness, the better the slipperiness.

[0060]

[Development treatment] The PS plate thus obtained is passed through a transparent original image through a carbon arc lamp, a mercury lamp, a metal halide lamp,
After being exposed to an actinic ray using a xenon lamp, a tungsten lamp, or the like as a light source, development processing is performed. As a developer and a replenisher for such a PS plate, a conventionally known alkaline aqueous solution can be used. For example, sodium silicate, potassium, sodium triphosphate, potassium, ammonium, sodium diphosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, sodium Inorganic alkaline agents such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium are mentioned.
Further, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkaline agents such as ethyleneimine, ethylenediamine and pyridine are also used.

These alkaline agents may be used alone or in combination of two or more. Among these alkaline agents, an aqueous solution of silicate such as sodium silicate or potassium silicate is particularly preferable as the developer for positive PS plate. The reason is that the ratio of silicon oxide SiO ₂ which is a component of silicate and alkali metal oxide M ₂ O (generally [SiO ₂ ] / [M ₂
This is because the developability can be controlled by the concentration and the concentration). For example, JP-A-54-6200
No. 4 as disclosed in Japanese, the molar ratio of SiO ₂ / Na ₂ O 1.0 to 1.5 (that is, [SiO _2] / [Na ₂ O] is 1.0 to 1.
5), wherein an aqueous solution of sodium silicate having a SiO ₂ content of 1 to 4% by weight or [SiO ₂ ] / [M] as described in JP-B-57-7427 is 0. 0.5 to 0.75
(That is, [SiO ₂ ] / [M ₂ O] is 1.0 to 1.5) and Si
An alkali metal silicate having a concentration of O ₂ of from 1 to 4% by weight and the developer containing at least 20% of potassium, based on the gram atoms of all alkali metals present therein. Acid salts are preferably used.

Further, the PS plate was developed using an automatic processor.
Aqueous solution with higher alkaline strength than developer
Develop for a long time by adding (replenisher) to the developer
A large amount of PS plate can be processed without changing the developer in the tank.
It is known that it can be processed. PS of the present invention
This replenishment system is preferably applied to the plate as well. example
For example, it is disclosed in JP-A-54-62004.
Una developer SiO₂/ Na ₂The molar ratio of O is 1.0 to 1.5 (that is,
(SiO₂] / [Na₂O] is 1.0 to 1.5), and SiO₂Including
Use an aqueous solution of sodium silicate with a content of 1-4% by weight
In addition, depending on the throughput of the positive photosensitive lithographic printing plate,
SiO continuously or intermittently₂/ Na₂The molar ratio of O is 0.5-1.5 (immediately
Chi (SiO₂] / [Na₂O] is 0.5-1.5) sodium silicate
Method of adding an aqueous solution (replenisher) to the developer, and
[SiO 2 disclosed in Japanese Kokai No. 57-7427]₂]
/ [M] is 0.5 to 0.75 (ie [SiO₂] / [M₂O] is 1.
0-1.5), and SiO₂Is 1 to 4% by weight
Use as a replenisher by using an alkali metal silicate developer
Alkali metal silicate [SiO₂] / [M] is 0.25
~ 0.75 (ie [SiO₂] / [M₂O] is 0.5-1.5)
And both the developer and the replenisher are in it.
Less based on gram atoms of all existing alkali metals
Both contain 20% potassium and
The imaging method is preferably used.

When an alkali metal silicate is used as the replenishing solution, the replenishing solution becomes highly active and the replenishing amount can be reduced by reducing the molar ratio [SiO ₂ ] / [M ₂ O]. However, running cost and amount of waste liquid are reduced, which is preferable. However, when the PS plate support is an aluminum plate due to high activation, aluminum is dissolved,
It is known to produce insoluble matter in the developer. However, since the PS plate of the present invention has the back coat layer on the back surface of the support, it is possible to suppress the elution of aluminum from the back surface, and therefore the high activity development replenishing system can be preferably used. As such a highly active developer, an alkali having a SiO ₂ / M ₂ O molar ratio of 0.7 to 1.5 and a SiO ₂ concentration of 1.0 to 4.0% by weight is used. It consists of an aqueous solution of metal silicate, and the replenisher is SiO ₂ / M ₂ O.
Has a molar ratio of 0.3 to 1.0 and a SiO ₂ concentration of 0.5 to 4.
A system which is a 0% by weight aqueous solution of an alkali metal silicate is preferably used.

The developer and replenisher used in the development of the positive and negative PS plates of the present invention include the ones which promote or suppress the developing property,
If necessary, various surfactants and organic solvents can be added for the purpose of dispersing the development dust and improving the ink affinity of the image portion of the printing plate. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan. Fatty acid partial ester, pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, poly Glycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acids Ethanol amides, N, N-
Nonionic surfactants such as bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, and trialkylamine oxides,

Fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts,
Dialkylsulfosuccinate ester salts, linear alkylbenzene sulfonates, branched chain alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl- N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfuric acid ester salts of fatty acid alkyl esters, alkyl sulfuric acid ester salts, polyoxyethylene alkyl ether sulfuric acid ester salts, Fatty acid monoglyceride sulfate ester salts, polyoxyethylene alkylphenyl ether sulfate ester salts, polyoxyethylene styryl phenyl ether sulfate ester salts, Rukylic phosphoric acid ester salts, polyoxyethylene alkyl ether phosphoric acid ester salts, polyoxyethylene alkylphenyl ether phosphoric acid ester salts, partial saponification products of styrene / maleic anhydride copolymers, and partial olefin / maleic anhydride copolymers Anionic surfactants such as saponification products and naphthalene sulfonate formalin condensates,

Cationic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts and polyethylene polyamine derivatives,
Examples thereof include amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. Among the above-mentioned surfactants, those having polyoxyethylene can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene and polyoxybutylene, and these surfactants are also included. A more preferable surfactant is a fluorinated surfactant containing a perfluoroalkyl group in the molecule. Such fluorine-based surfactants include perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, anionic systems such as perfluoroalkyl phosphates, amphoteric systems such as perfluoroalkyl betaines, and perfluoroalkyl trimethyl ammonium salts. Cationic system and perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct, perfluoroalkyl group and hydrophilic group-containing oligomer, perfluoroalkyl group and lipophilic group-containing oligomer, perfluoroalkyl group, hydrophilic group and lipophilicity Nonionic compounds such as group-containing oligomers, perfluoroalkyl group- and lipophilic group-containing urethanes can be mentioned.

The above-mentioned surfactants can be used alone or in combination of two or more kinds, and they can be used in a developing solution in an amount of 0.0
It is added in the range of 01 to 10% by weight, preferably 0.01 to 5% by weight. A preferable organic solvent has a solubility in water of about 10% by weight or less, and is preferably selected from 5% by weight or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-1.
-Butanol, 2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol and 4 -Methylcyclohexanol,
Examples thereof include N-phenylethanolamine and N-phenyldiethanolamine. The content of the organic solvent is 0.1 to 5% by weight based on the total weight of the developer.
The amount used is closely related to the amount used of the surfactant,
It is preferred to increase the amount of surfactant as the amount of organic solvent increases. This is because the amount of surfactant is small, and when using a large amount of organic solvent, the organic solvent does not completely dissolve,
Therefore, it cannot be expected to secure good developability.

A reducing agent may be further added to the developer and the replenisher used for developing the PS plate of the present invention. This is to prevent stains on the printing plate and is particularly effective when developing a negative PS plate containing a photosensitive diazonium salt compound. Preferable organic reducing agents include phenol compounds such as thiosalicylic acid, hydroquinone, methol, methoxyquinone, resorcin, and 2-methylresorcin, and amine compounds such as phenylenediamine and phenylhydrazine. More preferable inorganic reducing agents include sodium salts, potassium salts, and ammonium salts of inorganic acids such as sulfurous acid, bisulfite acid, phosphorous acid, hydrogen phosphite, dihydrogen phosphite, thiosulfuric acid and dithionous acid. Examples thereof include salt. Among these reducing agents, sulfite has a particularly excellent antifouling effect. These reducing agents are preferably added to the developing solution at the time of use at 0.05
It is contained in the range of up to 5% by weight.

An organic carboxylic acid may be further added to the developer and the replenisher. Preferred organic carboxylic acids are aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids. Specific examples of the aliphatic carboxylic acid include caproic acid, enanthic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred is an alkanoic acid having 8 to 12 carbon atoms. . Further, it may be an unsaturated fatty acid having a double bond in the carbon chain or a branched carbon chain. The aromatic carboxylic acid is a compound in which a benzene ring, a naphthalene ring, an anthracene ring or the like is substituted with a carboxyl group, and specifically, o-chlorobenzoic acid, p-chlorobenzoic acid, o-
Hydroxybenzoic acid, p-hydroxybenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6
-Dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid , 1-naphthoic acid, 2-naphthoic acid and the like, but hydroxynaphthoic acid is particularly effective.

The above-mentioned aliphatic and aromatic carboxylic acids are preferably used as sodium salts, potassium salts or ammonium salts in order to enhance the water solubility. Although the content of the organic carboxylic acid in the developer used in the present invention is not particularly limited,
If it is less than 1% by weight, the effect is not sufficient, and 10% by weight
Above, not only the effect cannot be further improved, but dissolution may be hindered when another additive is used in combination. Therefore, the preferable addition amount is 0.1 to 1 with respect to the developing solution at the time of use.
It is 0% by weight, and more preferably 0.5 to 4% by weight. If necessary, the developer and the replenisher may further contain a conventionally known compound such as a defoaming agent, a water softener and an organic boron compound described in JP-B-1-57895.

Examples of the water softener include polyphosphoric acid and its sodium salt, potassium salt and ammonium salt,
Aminopolycarboxylic acids such as ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid and 1,3-diamino-2-propanoltetraacetic acid, and Sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylenetetraminehexa (methylenephosphonic acid), hydroxyethylethylenediaminetri (methylene). Phosphonic acid) and 1-hydroxyethane-1,1-
Mention may be made of diphosphonic acids and their sodium, potassium and ammonium salts.

The maximum value of such a water softener varies depending on its chelating power, the hardness of hard water used, and the amount of hard water. 0.01-5% by weight, more preferably 0.01-0.
It is in the range of 5% by weight. If the addition amount is less than this range, the intended purpose is not sufficiently achieved, and if the addition amount is more than this range, the image area is adversely affected such as color loss. The remaining component of the developing solution and the replenishing solution is water, but if desired, various additives known in the art can be added. It is advantageous in terms of transportation that the developing solution and the replenishing solution are concentrated solutions having a water content smaller than that at the time of use and are diluted with water at the time of use. In this case, the degree of enrichment should be such that each component does not separate or precipitate.

The PS plate thus developed is post-treated with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing arabic gum and starch derivatives and the like. Various combinations of these treatments can be used for the post-treatment of the PS plate of the present invention. In recent years, in the plate making / printing industry, automatic developing machines for PS plates have been widely used in order to rationalize and standardize the plate making work. This automatic developing machine is generally composed of a developing section and a post-processing section, and is composed of a device for conveying a PS plate, each processing liquid tank and a spraying device. Each processing solution is sprayed from a spray nozzle for development processing.
Further, recently, a method has also been known in which a PS plate is dipped and conveyed by a submerged guide roll or the like in a treatment liquid tank filled with the treatment liquid for treatment. In such automatic processing,
It is possible to carry out the processing while supplementing the replenishing solution to each processing solution according to the processing amount, operating time and the like. Further, a so-called disposable processing method of processing with a substantially unused processing liquid can be applied. The planographic printing plate obtained by such treatment is set on an offset printing machine and used for printing a large number of sheets.

[0074]

EXAMPLES The present invention will be described in more detail below with reference to examples. Examples 1 to 12 and Comparative Examples 1 to 2 An aluminum plate having a thickness of 0.30 mm and a nylon brush and 40
The surface was grained using a 0-mesh aqueous suspension of pumice and then thoroughly washed with water. It was immersed in 10% sodium hydroxide at 70 ° C. for 60 seconds for etching, washed with running water, neutralized with 20% HNO ₃ and washed with water. This is V
Electrolytic surface roughening treatment was carried out in an aqueous 1% nitric acid solution under the condition of _A = 12.7V in an aqueous 1% nitric acid solution at an anode electricity of 160 coulomb / dm ² . The surface roughness was measured and found to be 0.6 μ (Ra indication). 30% continuously
Of H ₂ SO ₄ aqueous solution and desmutted at 55 ° C. for 2 minutes, and then anodized in 20% H ₂ SO ₄ aqueous solution at a current density of 2 A / dm ^{2 to} a thickness of 2.7 g / m ^2. Then, the substrate was prepared.

The surface of the obtained substrate was coated with the following photosensitive solution, and a photosensitive layer was provided so that the coating weight after drying was 2.5 g / m ² . Photosensitive solution Esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin (described in Example 1 of US Pat. No. 2,635,709) 0.45 parts by weight Cresol formaldehyde novolak resin 1.1 〃 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine 0.02 〃 Oil Blue # 603 (manufactured by Oriental Chemical Co., Ltd.) 0.01 〃 Megafac F -177 (Fluorine-based surfactant manufactured by Dainippon Ink and Chemicals, Inc.) 0.004 〃 Methyl ethyl ketone 10 〃 Propylene glycol monomethyl ether 10 〃 Matt layer is formed on the surface of the photosensitive layer thus prepared as follows. The resin liquid for spraying was sprayed to form a mat layer.

As a resin liquid for forming a mat layer, a part of the copolymer of methyl methacrylate / ethyl acrylate / acrylic acid (charge ratio of 65:20:15) was used as sodium salt (potassium salt or ammonium salt). The prepared 12% aqueous solution was prepared, and the atomization head rotation speed was 25,000 rpm with a rotary atomization electrostatic coating machine, and the resin liquid feed rate was 4
0 ml / min, the applied voltage to the atomizing head is -90 kv, the ambient temperature at the time of application is 25 ° C, the relative humidity is 50%, and the application surface is wetted by blowing steam for 2.5 seconds after application, and then wet. After 3 seconds, hot air having a temperature of 60 ° C. and a humidity of 10% was blown for 5 seconds to dry. The average height of the mat was about 6 μm, the average diameter was about 30 μm, and the coating amount was 150 mg / m ² .

Next, a saturated copolymer polyester resin (trade name: Chemit K-1294, manufactured by Toray: glass transition point 10
(0 ° C.) 3.0 parts by weight was dissolved in 100 parts by weight of methyl ethyl ketone, and 0.05 parts by weight of the surfactant shown in Table 1 below was added as an active ingredient to prepare a back coat layer forming solution. The PS plate a to 1 was obtained by coating and drying on the back surface of the support of the PS plate shown in (2) so that the thickness after drying was 0.2 μm. For comparison, the PS plate having a back coat layer to which no surfactant was added was designated as m, and the PS plate having no back coat layer on the back surface was designated as n.

The 14 kinds of PS plates thus obtained were cut into 1003 mm × 800 mm, and 30 sheets were prepared for each.
These 30 sheets were piled up, one sheet of cardboard having a thickness of about 0.5 mm was placed on each of the upper and lower sides, and the four corners were taped to each other, and then wrapped with aluminum kraft paper. This was further packaged in a cardboard case, taped, and then subjected to a truck transportation test. Exactly the same test was performed on a sample in which pure pulp paper was sandwiched with interleaving paper. Next, each of the same 14 types of PS plates 1,
After stacking 500 sheets, iron backing plates were placed on the top and bottom, and left for 5 months in a bolted mass transport mode, the bolts were removed and the adhesion between PS plates was examined. Table 1 shows the presence / absence of the adhesion and the result of the film peeling. Next, the PS plate was fixed on a tilt table of a static friction angle measuring instrument (manufactured by Shinto Kagaku Co., Ltd.) so that the back coat layer was on the upper surface. 35 mm
Fix the interleaving paper on a smooth flat surface with a weight of × 75 mm and a weight of 200 g, and put the weight on the back coat layer through the interleaving paper.
The angle θ when the weight begins to slide as the plate is gradually tilted
The slipperiness tan θ was obtained. Similarly, a photosensitive layer (including a matte layer) is applied to the smooth flat surface of the weight, the weight is placed on the backcoat layer through the photosensitive layer, and the PS plate is gradually tilted to the backcoat layer in the same manner. Between the photosensitive layer and
tan θ was determined and the results are shown in Table 1.

[0079]

[Table 1] Table 1 Without interleaving paper Without interleaving paper Sliding (tan θ) When added and stored in transit by transportation Transport against PS plate surfactant Photosensitive layer Photosensitive layer of photosensitive layer and interleaf paper Photosensitive layer Scratch Scratch Scratch Adhesion on backside Example 1a Rathosol B-80 Almost no 0.45 0.47 No No NOF Corporation 2b Haionin A-32B Same as above None 0.47 0.50 Takemoto Yushi Kogyo Co., Ltd. 3c Demol NL 〃〃 None 0.46 0.50 Kao Corporation 4 d Emulgen 906 〃 〃 None 0.44 0.46 Kao Corporation 5 e Pluronic F-68 〃 〃 None 0.46 0.48 Asahi Denka Kogyo Co., Ltd. 6 f Tween 20 〃 None 0.46 0.48 Kao ( Co., Ltd. 7 g Span 40 〃 〃 None 0.45 0.47 Kao Co., Ltd. 8 h Pionine B-111 〃 〃 None 0.48 0.50 Takemoto Yushi Kogyo Co., Ltd. 9 i Ammo K K 〃 None 0.45 0.48 Daiichi Kogyo Seiyaku Co., Ltd. 10 j Amoven No.8 〃 〃 None 0. 46 0.48 Dai-ichi Kogyo Seiyaku Co., Ltd. 11 k Mechafuck F-177 None at all None 0.40 0.41 Dainippon Ink and Chemicals Incorporated 12 l Surflon S-131 None at all None 0.43 0.45 Asahi Glass Co., Ltd. Comparative Example 1 m No surfactant Yes Yes Yes Some Yes 0.53 0.55 2 n No back coat layer Yes Many Yes Yes 0.56 0.61 ─────────────────────────── ────────

Note) Lapizole B-80: Sulfodialkyl succinate Na salt Paionin A-32B: Sodium alkylsulfonate demol NL: Formaldehyde condensate of sodium naphthalenesulfonate Emulgen 906: Polyoxyethylene nonylphenyl ether Pluronic F-68 : Polyoxyethylene-polyoxypropylene block copolymer Tween 20: polyoxyethylene sorbitan monolaurate span 40: sorbitan monolaurate paionin B-111: trimethyllauryl ammonium chloride amogen K: betaine-type amphoteric activator amogen No. 8: imidazoline Type Amphoteric Activator Megafac F-177: Oligomer containing fluorocarbon alkyl group, hydrophilic group and lipophilic group Surflon S-131: Perflutroalkylbetaine By adding a surfactant to the organic coating layer on the back surface, scratches on the photosensitive layer in the transport test are less likely to occur, and particularly with resins k and l containing a fluorosurfactant. The effect was obtained.

Further, 100 of each of the 14 types of PS plates described above was used.
Prepare one piece cut into a size of 3 mm × 800 mm,
These were exposed through a document film for 60 seconds from a distance of 1 m using a 3 kw metal halide lamp. A commercially available automatic processor PS-900D (manufactured by Fuji Photo Film Co., Ltd.) having an immersion type developing tank was provided with a developing tank of [SiO ₂ ] / [M ₂
O] ratio 1.2, Si ₂ (wt%) 1.5 potassium silicate aqueous solution, and N-alkyl-N, N-dihydroxyethyl betaine amphoteric surfactant 0.04 wt% developer solution was charged. The exposed photosensitive lithographic printing plate described above was processed.
As a result, all the samples could be well developed and the back coat layer did not peel off from the back surface.

EFFECT OF THE INVENTION An organic polymer compound having a photosensitive layer having a specific matte layer formed on the surface of a support of a photosensitive lithographic printing plate and having a glass transition point of 20 ° C. or less and a surfactant are provided on the back surface of the support. By providing a back coat layer containing and, even if a large number of photosensitive lithographic printing plates are stacked and transported or stored regardless of the presence or absence of reproducible interleaving paper, the scratches and adhesion of the photosensitive film are effectively prevented. Can be prevented.

Claims (2)

[Claims] 1. A photosensitive layer on the surface of a support having an average diameter of 10
˜100 μm, an average height of 1 to 10 μm, and a coating layer of ⁵ to 200 mg / m ² in order,
In addition, the back surface of the support has a thickness of 0.01 to 8.0 including an organic polymer compound having a glass transition point of 20 ° C. or higher and a surfactant.
A photosensitive lithographic printing plate comprising a back coat layer of μm. 2. The slip property between the back coat layer and the interleaving paper or the photosensitive layer is tan θ = 0.50 or less.
The photosensitive lithographic printing plate described.