JPH01186967A - Printing plate for electrophotographic engraving - Google Patents

Abstract

PURPOSE:To prevent staining of a non-image part at the time of printing by forming an intermediate layer of a compd. selected from compds. having an amino group and hydroxyl group and the salts thereof. CONSTITUTION:The intermediate layer is formed on the compd. selected from the compds. having at least one amino group and at least one hydroxyl group and the salts thereof. Such compd. is adequately the compd. having <=1,000mol. wt., for which, for example, monoethanol amine, diethanol amine, trimethanol amine, tripropanol amine, triethanol amine and the hydrochloride, oxalate and phosphate thereof are useful; above all, the triethanol amine and triethanol amine hydrochloride are most preferable. The staining in the non-image part at the time of printing is thereby prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a printing plate for electrophotographic platemaking having an electrophotographic photosensitive layer. In particular, it relates to a printing plate for electrophotographic plate making that does not stain non-image areas during printing.

[Prior art] Today, as flat plate offset printing plates, there are 28 plates that use positive-working photosensitizers whose main components are diazo compounds and phenolic resins, and negative-working photosensitizers whose main components are acrylic monomers and prepolymers. Although these have been put into practical use, all of them have low sensitivity, and plate making is performed by closely exposing a silver halide photographic film original plate on which an image has been recorded in advance. on the other hand,
In recent years, advances in computer image processing, large-capacity data storage, and data communication technology have meant that everything from inputting, correcting, editing, and layout to page layout has become computer-operated, and high-speed communication networks and satellite communications have made it possible to instantly send documents to remote locations. Electronic editing systems that can output to terminal plotters have been put into practical use. The demand for electronic editing systems is particularly high in the newspaper printing field, where immediacy is required, and in fields where originals are stored in the form of original film, and printed versions are reproduced as needed based on this. With the development of ultra-high capacity recording media such as optical discs, it is thought that originals will be stored as digital data on these recording media.

However, direct printing plates that create printing plates directly from the output of terminal blocks have hardly been put into practical use.
Even in places where electronic [1] systems are in operation, the actual situation is that output is performed on silver halide photographic film, and based on this, printing plates are created indirectly by contact exposure to PS plates. This is the light source of the output block (e.g. He-N
This is because it is difficult to develop a direct printing plate with a sensitivity high enough to make a printing plate within a practical time using e-lasers, semiconductor lasers, etc.).

Electrophotographic photoreceptors are considered as photoreceptors with high photosensitivity that can provide direct printing plates.

Conventionally, as printing plate materials (printing original plates) using electrophotography, for example, Japanese Patent Publication No. 47-47610, Japanese Patent Publication No. 48
-40002, Special Publication No. 18325, Special Publication No. 18325, Special Publication No. 18325
1-15766, Japanese Patent Publication No. 51-25761, etc., there are known zinc oxide-resin dispersion offset printing plate materials, which make the non-image area non-greasy after forming a toner image by electrophotography. It is used after being moistened with a desensitizing solution (for example, a ferrocyanate or an acidic aqueous solution containing a ferricyanate) to make the material more opaque. Offset printing plates treated in this way have a stiffness of about 5,000 to 10,000 sheets, and are not suitable for printing beyond this, and if they are made into a composition suitable for desensitization, their electrostatic properties deteriorate. , and has disadvantages such as deterioration of image quality. It also has the disadvantage of using harmful cyanide compounds as desensitizing solutions.

Special Publication No. 37-17162, Special Publication No. 38-7758,
In the organic photoconductor-resin printing plate materials described in Japanese Patent Publication No. 46-39405 and Japanese Patent Publication No. 52-2437, for example, oxazole or oxadiazole compounds are combined with a styrene-maleic anhydride copolymer. An electrophotographic photoreceptor is used in which a photoconductive insulating layer is formed on a grained aluminum plate, and after a toner image is formed on this photoreceptor by electrophotography, the non-image area is dissolved with an alkaline organic solvent. Upon removal, a printing plate is formed.

In addition, the present inventors disclosed an electrophotographic photosensitive printing plate material containing a hydrazone compound and barbylic acid or thiobarbylic acid in JP-A-57-147656. In addition, JP-A No. 5.9-147335,
JP-A-59-152456, JP-A-59-16846
Dye-sensitized printing plates for electrophotographic platemaking such as No. 2 and JP-A-58-145495 are known. However, substances in the electrophotographic photosensitive layer are adsorbed to the non-image area of the printing plate for electrophotographic platemaking and contaminate the non-image area, so ink adheres to the non-image area of the printed matter, causing "stains". There was a problem in that it could no longer be used as a printing plate because of this. In order to solve this problem, we have developed a method of physically or chemically making the conductive substrate hydrophilic, for example, by immersing the surface of an aluminum substrate, which has been subjected to anodic scratching, in an alkali metal silicate as described in U.S. Pat. No. 3,181,461. There are known methods to do this, but none of them are fully satisfactory.

[Object of the Invention] An object of the present invention is to provide a printing plate for electrophotographic platemaking that is free from stains in non-image areas during printing.

Another object of the present invention is to provide a printing plate for electrophotographic platemaking that has sufficient sensitivity to directly create a printing plate using a laser or the like.

Another object of the present invention is to provide a printing plate for electrophotographic platemaking with excellent electrostatic properties.

[Means for solving the problem] As a result of intensive studies, the inventors found that at least a conductive substrate,
In an electrophotographic printing plate comprising an intermediate layer and an electrophotographic photosensitive layer, the intermediate layer has at least one amino group,
The above object could be achieved by a printing plate for electrophotographic plate making characterized by being made of a compound selected from compounds having at least one hydroxyl group and salts thereof.

Hereinafter, the present invention will be explained in detail step by step.

The electrically conductive substrates used in the invention include plastic sheets with electrically conductive surfaces or especially solvent-impermeable and electrically conductive papers, aluminum plates, zinc plates, or copper-aluminum plates, copper-stainless steel plates, Bimetal plates such as chrome-copper plates, or chrome-copper-aluminum plates,
A conductive substrate having a hydrophilic surface such as a tri-metal plate such as a chromium-lead-iron plate or a chromium-copper-stainless steel plate is used, and its thickness is preferably 0.1 to 3 mm, particularly 0.1 to 3 mm.
1 to 0.5 mm is preferred. Among these substrates, an aluminum plate having an anodic oxide film is preferably used.

The aluminum plate used in the present invention is a plate-shaped body made of pure aluminum containing aluminum as a main component or an aluminum alloy containing a trace amount of foreign atoms.

These foreign atoms include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The alloy composition has a content of at most 10% by weight or less. Aluminum suitable for the present invention is pure aluminum, but since it is difficult to produce completely pure aluminum due to smelting technology, it is preferable to use aluminum that contains as few foreign atoms as possible. Furthermore, any aluminum alloy having the above-mentioned content can be said to be a material that can be applied to the present invention. As described above, the composition of the aluminum plate applied to the present invention is not specified; conventionally known and publicly used materials can be used as appropriate.

Prior to anodizing the aluminum plate, degreasing treatment, such as treatment with a surfactant or alkaline aqueous solution, and graining treatment are performed as desired to remove rolling oil from the surface.

Graining treatment methods include a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. As a method for mechanically roughening the surface, known methods such as ball polishing, brush polishing, blast polishing, puff polishing, etc. can be used.

Electrochemical surface roughening methods include methods using alternating current or direct current in a hydrochloric acid or nitric acid electrolyte.
IJI Publication No. Sho 54-63902 + [: A method combining the two can also be used as disclosed.

The aluminum plate thus roughened is subjected to alkali etching treatment and neutralization treatment as necessary.

Sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used as the electrolyte for anodizing the aluminum plate, and the electrolyte and its concentration are determined as appropriate depending on the type of electrolyte. The processing conditions for anodic oxidation vary depending on the electrolyte used, so they cannot be specified, but in general, the electrolyte concentration is 1 to 80% by weight, the liquid temperature is 5 to 70°C, and the current density is 5 to 60 A/w. dm”, voltage l
~100V and electrolysis time of 10 seconds to 50 minutes are suitable.

The amount of the anodic oxide film is preferably O.Ig/m'', more preferably in the range of 1 to 6 g/m''. The printing plate of the present invention can be produced by coating a solution of the compound of the present invention dissolved in water or an organic solvent such as methanol on the anodized film of the aluminum plate treated as described above and drying it to form an intermediate layer. A support for use is obtained. It consists of a compound selected from compounds having at least one amino group and at least one hydroxyl group and salts thereof used in the present invention. Suitable such compounds are those having a molecular weight of 1.000 or less. As specific compounds thereof, for example, monoethanolamine, jetanolamine, trimethanolamine, tripropaturamine, triethanolamine, and their hydrochlorides, oxalates, and phosphates are useful.

Among these, triethanolamine and triethanolamine hydrochloride are most preferred.

Hydrophilic compounds as described above can be prepared in a suitable solvent such as water,
0.001-10% by weight in alcohol such as methanol
It is dissolved at a concentration of and used as a coating solution. At this time, it is appropriate that the pH after coating is in the range of 1-13. Further, the temperature of the coating liquid is suitably in the range of 10 to 50°C.

As the coating method, any method such as dip coating, spin coating, spray coating, curtain coating, etc. may be used, and the coating amount after drying is 1 to 109 mg/m.
” is suitable, more preferably 5 to 50 mg/m'
is within the range of As the above-mentioned coating amount becomes less than 1 mg/m'', it becomes less effective in preventing stains in non-image areas, and on the other hand, as it becomes more than 100 mg/m, the adhesion between the photosensitive layer and the support deteriorates, and the stiffness resistance decreases. Only a printing plate for electrophotographic platemaking with a low viscosity can be obtained.

Before or after providing such an intermediate layer, the anodized aluminum plate can be treated with an aqueous solution of an alkali metal silicate (e.g. sodium silicate) as described in U.S. Pat. No. 3,181°461. can.

The intermediate layer on the conductive substrate thus obtained includes:
The printing plate for electrophotographic platemaking of the present invention can be obtained by providing a conventionally known electrophotographic photosensitive layer. As the photoconductive material, many conventionally known inorganic or organic compounds can be used. For example, inorganic photoconductive materials include selenium and selenium alloys, amorphous silicon, Cd, Cd's, Cd5Se, ZnO1Zn
Examples include S. In addition, as organic photoconductive materials, (1) polyvinyl carbazole and its derivatives described in Japanese Patent Publication No. 34-10966, (2) Japanese Patent Publication No. 43-1
Polyvinylpyrene, polyvinylanthracene, poly-2 described in JP-A No. 8674 and Japanese Patent Publication No. 43-19192
-vinyl-4-(4'-dimethylaminophenyl)-5
- Vinyl polymers such as phenyl-oxazole and poly-3-vinyl-N-ethylcarbazole, (3) Japanese Patent Publication No. 4
Polymers such as polyacenaphthylene, polyindene, copolymer of acenaphthylene and styrene, etc. described in Japanese Patent Publication No. 3-19193, (4) Pyrene-formaldehyde resin, bromopyrene-formaldehyde resin described in Japanese Patent Publication No. 13940-1984, etc. , condensation resin such as ethylcarbazole-formaldehyde resin, (5) JP-A-56-9
Various triphenylmethane polymers described in No. 0883 and JP-A-56-161550, and low-molecular ones include (6) triazole derivatives described in U.S. Pat. No. 3,112,197, etc.; (7) ) Oxadiazole derivatives described in US Pat. No. 3,189,447, etc., (8) Equity-37-
Imidazole derivatives described in Publication No. 16096, etc. (9) U.S. Patent No. 3615402, U.S. Patent No. 382098
No. 9, No. 3542544, Special Publication No. 45-555, No. 10983-1983, Japanese Patent Publication No. 93224-1971,
JP-A-55-108667, JP-A-55-15695
No. 3, polyarylalkane derivatives described in JP-A-56-36656, publications, etc. (10) U.S. Pat. No. 3,180,729, U.S. Pat. -88065, JP 49-105537, JP 55-51086, JP 56-80051,
JP-A-56-88141, JP-A-57-45545, JP-A-54-112637, JP-A-55-7454
Pyrazoline derivatives and pyrazolone derivatives described in No. 6 specifications, publications, etc. (11) U.S. Patent No. 3,615,404, Japanese Patent Publication No. 1987-1
No. 0105, JP-A-54-83435, JP-A-54-
110836, JP-A-54-119925, JP-A-46-3712, JP-A-47-28336,
Phenyl diamine derivatives described in publications, etc. (!2) U.S. Patent No. 3,567,450, Japanese Patent Publication No. 49
-35702, West German Patent (DAS) 11105
No. 18, U.S. Patent No. 3180703, U.S. Patent No. 32
No. 40597, U.S. Patent No. 3658520, U.S. Patent No. 4232103, U.S. Patent No. 4175961, U.S. Patent No. 4012376, JP 55-144250
No., JP-A No. 56-119132, JP-A No. 39-275
77, JP-A-56-22437, publications, etc., (13) amino-substituted chalcone derivatives described in U.S. Pat. No. 3,526,501, (14) U.S. Pat. No. 3,542,546. (15) Oxazole derivatives described in US Pat. No. 3,257,203, etc.; (16) Styryl anthracene derivatives described in JP-A-56-46234, etc.; (17) ) Fluorenone derivatives described in JP-A-54-110837, etc., (18) U.S. Patent No. 3717462, JP-A-54
-59143 (corresponding to U.S. Patent No. 4,150,987)
, JP-A-55-52063, JP-A-55-52064
No., JP-A-55-46760, JP-A-55-8549
No. 5, JP-A-57-11350, JP-A-57-148
No. 749, JP-A-57-104144, JP-A-60-
Hydrazone derivatives disclosed in No. 186847 specification, publications, etc.

(19) Benzidine derivatives described in US Pat. No. 4,047,948, US Pat. No. 4,047,949, US Pat. No. 4,265,990, US Pat. No. 4,273,846, US Pat. No. 4,299B97, US Pat. No. 4,306,008, etc.

(20) JP-A-58-190953, JP-A-59
-95540, JP-A-59-97148, JP-A-5
Stilbene derivatives described in U.S. Pat. No. 9-195658, JP-A-62-36674, etc. Same 5B
-123541, 58-192042, 60-
No. 179746, No. 61-148453, No. 61-2
No. 3806.3, Special Publication No. 60-5941, No. 60-4
Monoazo, bisazo, trisazo pigments described in No. 5,664, etc. (22) U.S. Patent No. 3,397,086
Phthalonanine pigments such as metal phthalocyanine or 1M metal phthalocyanine described in US Pat. No. 4,666.802 (23) Perylene pigments described in US Pat. Indigo and thioindigo derivatives (25) described in British Patent No. 237,680, etc. Quinacridone pigments (26) described in British Patent No. 2,237,680, etc. British Patent No. 2,237.678, JP-A-5'9 -184.348, 62-738, etc. (27) Bisbenzimidazole R-based materials described in JP-A-47-30,331, etc. (28) U.S. Patent No. 4, Squarium base pigments (29) described in JP-A No. 396,610, JP-A No. 4゜644.082, etc. JP-A No. 59-53,850, JP-A No. 61-
The azulenium salt pigment described in No. 212.542 etc. These organic photoconductive materials may be used in combination of 111 or two or more.

Furthermore, as a sensitizing agent, triallylmethane dyes such as brilliant green, Victoria Blue 85 methyl violet, crystal violet, and acid violet 6B, rhodamine B, rhodamine 6G, rhodamine G extra, eosin S5 erythrosin, rose bengal, and fluorescein are used. xanthine dyes such as, thiadene dyes such as methylene blue, C,1,Ba5ic
Examples include astrazone dyes such as Violet 7, cyanine dyes, pyrylium dyes such as 2,6-diphenyl-4-(N, N-dimethylaminophenyl)thiapyrylium perchlorate, and benzobyrylium salts. .

In the printing plate for electrophotographic platemaking of the present invention, the photoconductive compound itself may have film properties, but if the photoconductive compound does not have film properties, a binding resin can be used. As the binding resin, resins commonly known in electrophotography can be used. In the present invention, it is necessary to finally remove the photoconductive layer in the non-image area, but this process depends on the relative solubility of the photoconductive layer in the etching solution or the resistivity of the toner image to the etching solution. It is impossible to generalize because it depends on the relationship. However, in consideration of environmental safety, it is desirable to use as the etching solution an aqueous solution or a mixture with an organic solvent that is miscible with the aqueous solution described below. Therefore, the binding resin used in the present invention is preferably a polymer compound that is soluble or dispersible in the etching solution described below.

Examples of the binding resin include copolymers of styrene and maleic anhydride, copolymers of styrene and monoalkyl maleic anhydride, methacrylic acid/methacrylic ester copolymers, and styrene/methacrylic acid/methacrylic ester copolymers. Acrylic acid esters such as acrylic acid/methacrylic acid ester copolymer, styrene/acrylic acid/methacrylic acid ester copolymer, vinyl acetate/crotonic acid copolymer, vinyl acetate/crotonic acid/methacrylic acid ester copolymer, etc. , methacrylic acid ester, styrene,
Copolymers of vinyl acetate, etc., with carboxylic acid-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid anhydride, fumaric acid, or acid anhydride group-containing monomers, methacrylic acid amide, vinyl pyrrolidone, Examples include copolymers containing monomers having phenolic hydroxyl groups, sulfonic acid groups, sulfonamide groups, and sulfonimide groups, phenol resins, partially saponified vinyl acetate resins, xylene resins, and vinyl acetal resins such as polyvinyl butyral. Can be done.

A copolymer containing a monomer having an acid anhydride group or a carboxylic acid group as a copolymerization component, and a phenol resin have a high charge retention ability of a photoconductive insulating layer when used as a printing plate for electrophotolithography. It can be used with good results.

As the copolymer containing a monomer having an acid anhydride group as a copolymerization component, a copolymer of styrene and maleic anhydride is preferable. Half esters of this copolymer can also be used.

As a copolymer containing a monomer having a carboxylic acid group as a copolymerization component, a copolymer of two or more elements of acrylic acid or methacrylic acid and an alkyl ester, aryl ester or aralkyl ester of acrylic acid or methacrylic acid is used. Preferred examples include a copolymer of vinyl acetate and crotonic acid, and a terpolymer of vinyl acetate, a vinyl ester of a carboxylic acid having 2 to 18 carbon atoms, and crotonic acid. Particularly preferred among the phenolic resins are phenol, O-cresol, m-
Examples include novolac resins obtained by condensing cresol or p-cresol with formaldehyde or acetaldehyde under acidic conditions. The binding resin may be used alone or in combination of two or more types. When using a photoconductive compound and a binding resin, the sensitivity will decrease if the content of the photoconductive compound is small, so 1 part by weight of the binding resin is used. The photoconductive compound is 0.05 parts by weight or more,
More preferably, it can be used in an amount of 0.1 part by weight or more. Furthermore, if the photoconductive layer is too thin, it will not be able to charge the charge necessary for development, and if it is too thick, etching in the plane direction called side etching will occur, making it impossible to obtain a good image. It can be used in a range of 1 to 30μ, more preferably 0.5 to ioμ.

The printing plate for electrophotographic platemaking of the present invention is obtained by coating a photoconductive layer on a conductive substrate.

The coating liquid is obtained by dissolving each component constituting the photoconductive layer in a suitable solvent and coating the solution on a conductive substrate.

When using a component that is insoluble in a solvent such as a pigment, it can be used after being dispersed to a particle size of 5 μm to 0.1 μm using a dispersing machine such as a ball mill, paint shaker, Dyno Mill, or Attritor. The binding resin and other additives used in the photoconductive layer can be added during or after dispersing the pigment. The coating solution prepared in this way is applied by rotation.
A printing plate for electrophotolithography can be obtained by coating and drying on a substrate by a known method such as blade coating, knife coating, reverse meal coating, dip coating, rod bar coating, or spray coating. Solvents for creating the coating solution include halogenated hydrocarbons such as dichloromethane, dichloroethane, and chloroform, alcohols such as methanol and ethanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, ethylene glycol monomethyl ether, and 2-methoxyethyl acetate. Examples include glycol ethers such as, ethers such as tetrahydrofuran and dioxane, and esters such as ethyl acetate and butyl acetate.

The printing plate for electrophotographic platemaking of the present invention can be produced by a generally known process. That is, it is charged substantially uniformly in a dark place, and an electrostatic latent image is formed by imagewise exposure.

Examples of the exposure method include scanning exposure using a semiconductor laser, H'5-Ne laser, etc., reflection image exposure using a xenon lamp, tungsten lamp, fluorescent lamp, etc. as a light source, and contact exposure using a transparent positive film. Next, the electrostatic latent image is developed with toner. As the developing method, various conventionally known methods such as cascade development, magnetic brush development, powder cloud development, and liquid development can be used. Among these, liquid development is capable of forming fine images and is suitable for creating printing plates. The formed toner image is fixed using a known fixing method.
For example, fixing can be performed by heat fixing, pressure fixing, solvent fixing, or the like. A printing plate can be prepared by allowing the toner image thus formed to act as a resist and removing the electrophotographic photosensitive layer in non-image areas with an etching solution.

The etching solution used in the printing plate of the present invention may be an aqueous solution of an organic or inorganic acid, base, or a salt thereof, or an aqueous solution that is miscible therewith. Preference is given to using mixtures with solvents.

Specifically, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, phosphoric acid, thorium phosphoric acid, potassium phosphate, ammonia, and monoethanolamine, Amino alcohols such as tanolamine and triethanolamine are well known.

Examples of organic solvents that are miscible with the aqueous solution include alcohols, ketones, esters, and ethers.

Alcohols include lower alcohols and aromatic alcohols such as methanol, ethanol, propatool, butanol, benzyl alcohol, and phenethyl alcohol; cellsolves such as ethylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol; monoethanolamine, and Examples include amino alcohols such as tanolamine and triethanolamine. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like. Examples of the esters include ethyl acetate, isopropyl acetate, n-propyl acetate, 5ec-butyl acetate, isobutyl acetate, n-butyl acetate, 1-acetoxy-2-methoxyethane, ethylene glycol diacetate, and the like. Examples of ethers include ethyl ether, tetrahydrofuran, dioxane, 2-methoxyethanol, and ethylene glycol dimethyl ether.

These organic solvents can be mixed with the aqueous solution in any desired range, but are preferably used in an amount of 90% by weight or less of the mixed solution. A surfactant, an antifoaming agent, a coloring agent, etc. may be added to this etching liquid as necessary.

The toner used in the printing plate of the present invention preferably contains a resin component having resist properties to the etching solution. Examples of resin components include methacrylic acid,
Acrylic resin using methacrylic acid ester, vinyl acetate resin, copolymer of vinyl acetate and ethylene or vinyl chloride, vinyl chloride resin, vinylidene chloride resin, vinyl acecool resin such as polyvinyl butyral, polystyrene, styrene and butadiene. , copolymers such as methacrylic acid esters, polyethylene, polypropylene and their chlorinated products, polyester resins (e.g., polyethylene terephthalate, polyethylene isophthalate, polycarbonate of bisphenol A), polyamide resins (e.g., polycabramide, polyhexamethylene azide) Poamide,
Cellulose ester derivatives such as polyhexamelene sebacamide), phenolic resins, xylene resins, alkyd resins, vinyl-modified alkyd resins, gelatin, carboxymethylene cellulose, waxes, polyolefins,
There are wax etc.

When utilizing the printing plates of the present invention, the relationship between the toner and the conductive substrate having an oleophobic printing ink surface is often such that the former is oleophilic and the latter surface is hydrophilic; The degrees of oiliness and hydrophilicity are relative;
10 Oil-based printing ink property of the surface of the substrate means that the oil-based printing ink should not be retained on the substrate surface when the toner image area and the exposed substrate surface are adjacent, and the wood-based property of the substrate surface means that the toner image The oleophilicity of the toner means that the water repellency of the substrate surface should not be so strong that it is impossible to retain water when the part and the exposed substrate surface are adjacent, and the oleophilicity of the toner is 1n This means that it must not be so strong that it cannot hold oil-based printing inks. The surface of the conductive substrate may be oil-based printing ink-like and water-repellent (hydrophobic).

In the present invention, in addition to the photoconductive compound and the binding resin, additives may be added for the purpose of improving the sensitivity of the photoconductive layer, electrical properties such as charge retention, or film properties such as flexibility and coated surface condition. Sensitizers, plasticizers, surfactants, and other additives can be added. For example, as a sensitizer,
-65.439, 58-102.239, 58
-129°439, 62-71,965, and the like. Plasticizers include biphenyl, chlorinated biphenyl, O-terphenyl,
Examples include p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, and the like.

In the present invention, an overcoat layer that can be dissolved when the electrophotographic photosensitive layer is removed is provided on the electrophotographic photosensitive layer, if necessary, for the purpose of improving the electrostatic properties of the electrophotographic photosensitive layer, the development properties during toner development, or the image properties. be able to. . This overcoat layer is mechanically matted,
Alternatively, it may be a resin layer containing a cape agent.
As matting agents, silicon dioxide, zinc oxide, titanium oxide,
Zirconium oxide, glass particles, alumina, starch, polymer particles (e.g. particles of polymethyl methacrylate, polystyrene, phenolic resins, etc.) and U.S. Pat.
, 710.245, U.S. Patent No. 2.992.1
The matting agents described in No. 01 are included. Two or more of these can be used in combination. The resin used in the resin layer containing the matting agent is appropriately selected depending on the combination with the etching solution used. Specifically, for example, gum arabic, glue, gelatin% casein hese J
L/C1-cellulose (e.g. viscose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, etc.), starches (e.g. soluble starch, modified starch, etc.), polyvinyl alcohol, polyethylene oxide, poly Examples include acrylic acid, polyacrylamide, polyvinyl methyl ether, epoxy resin, phenol resin (novolak type phenol resin is particularly preferred), polyamide, polyvinyl butyral, and the like. Two or more of these can be used in combination.

[Examples] The present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. In addition, all parts in Examples indicate parts by weight.

Example 1 The surface of a JIS 1050 aluminum sheet was grained using a rotating nylon brush using a pumice water suspension as an abrasive. The surface roughness at this time (center line average roughness) is 0.5μ
Met. After washing with water, it was immersed in a 10% caustic soda aqueous solution at 70°C and etched so that the amount of aluminum dissolved was 6 g/m''.After washing with water, it was neutralized by immersing it in a 30% nitric acid aqueous solution for 1 minute, and then thoroughly washed with water. Thereafter, in a 0°7% nitric acid aqueous solution, using a square wave alternating waveform with an anode special voltage of 13 volts and a negative electrode voltage of 6 volts (Special Publication No. 55-1)
9.191)) Perform electrolytic surface treatment for 20 seconds,
After cleaning the surface by immersing it in a 50°C solution of % sulfuric acid, it was washed with water. Furthermore, the weight of the anodized film in 20% sulfuric acid aqueous solution is 3.0 g/m! Anodized so that
After washing with water and drying, a substrate (1) was prepared.

A solution having the following composition was applied to the surface of the substrate (summer) treated in this way and dried at 80° C. for 30 seconds.

The amount of film after drying was 10 mg/m''. In this way, a substrate (II) was produced.

Coating liquid for intermediate layer Triethanolamine 0.05 parts Methanol 94.95 parts Water
5.0 parts Next, the following photoconductive layer coating solution was applied to the substrates (1) and (■) using bar caulk, and dried at 120°C for 10 minutes to prepare a printing plate for electrophotographic platemaking.

Coating liquid for photoconductive layer Shimezu hydrazone compound shown below 25 parts Copolymer of benzyl metal rylate methacrylic acid (30 mol% methacrylic acid) 75 parts Thiopyrylium salt compound shown below 1.18 parts Methylene chloride 510 parts Methyl cellosolve acetate The dry film thickness of 150 copies of the thus prepared printing plate for electrophotographic platemaking was 4 μm.

Next, this sample was charged with a surface potential of ++ using a corona charger in a dark place.
After being charged to 400 V, it was exposed to tungsten light and developed with a liquid developer Ricoh MRP (Ricoh Co., Ltd.), thereby making it possible to obtain a clear positive image. Furthermore, the created image was heated at 120°C for 2 minutes to fix the toner image. This non-image area was etched with an etching solution prepared by diluting 40 parts of potassium silicate, 10 parts of potassium hydroxide, and 100 parts of ethanol in 800 parts of water. After removing and thoroughly rinsing with water, it was gummed and an offset printing plate could be created.

This printing plate was printed using a conventional method, and the 20,000th print was compared. The printing plate using the group Fi(n) did not have any stains, but the printing plate using the substrate (]) teeth,
The non-image area was smeared and was not suitable for practical use.

Example 2 The following intermediate layer coating liquid was applied to the substrate (1) in Example 1 to create a substrate (I[l).

Coating solution for intermediate layer Triethanolamine hydrochloride 0.05 parts Methanol 94.95 parts Water
5.0 Next, the board (1),
The following photoconductive layer coating solution was applied to (III) using a bar coater and dried at 120° C. for 10 minutes to prepare a printing plate for electrophotolithography.

Dispersion liquid for photoconductive layer Trisazo compound 1.0 parts Oxazole compound shown below 2.5 parts Copolymer of vinyl acetate and crotonic acid (RESYN No. 28-1310 manufactured by Kanebo NSC Co., Ltd.) 10 parts Tetrahydrofuran
The mixture was placed in a glass container of 100 parts G500 ml together with glass beads and dispersed for 60 minutes using a paint shaker (Toyo Seiki Seisakusho Co., Ltd.) to prepare a photoconductive layer dispersion.

The thickness of this photoelectric layer was about 4 microns. Example 1
A printed version was created in a similar manner.

This printing plate was printed using a conventional method, and the 20,000th print was compared. The printing plate using the substrate (III) did not have any stains, but the printing plate using the base Fi(1) did not have any stains. However, stains were generated in the non-image area, and it was not suitable for practical use.

Example 3 A substrate (fV) was prepared in exactly the same manner as in Example 1 except that jetanolamine was used instead of triethanolamine, and the photoconductive layer of Example 1 was coated thereon.

When a planographic printing plate was prepared using this printing plate for electrophotographic plate making, it was possible to print clearly and without stains in the non-image areas.

Example 4 A substrate (V) was prepared in exactly the same manner as in Example 2 except that jetanolamine was used instead of triethanolamine hydrochloride, and the photoconductive layer of Example 2 was coated thereon. When a planographic printing plate was prepared using this printing plate for electrophotographic plate making, it was possible to print clearly and without stains in the non-image areas.

Example 5 A substrate (Vl) was prepared in exactly the same manner as in Example 2 except that trimethanolamine was used instead of triethanolamine hydrochloride, and the photoconductive layer of Example 2 was coated thereon. When a planographic printing plate was prepared using this printing plate for electrophotographic plate making, it was possible to print clearly and without stains in the non-image areas.

Patent Applicant: Fuji Photo Film Co., Ltd. Procedural Amendment

Claims (1)

[Claims] In an electrophotographic printing plate comprising at least a conductive substrate, an intermediate layer, and an electrophotographic photosensitive layer, the intermediate layer is selected from compounds and salts thereof having at least one amino group and at least one hydroxyl group. A printing plate for electrophotographic platemaking characterized by being made of a compound.