JPH04281469A - Electrophotographic type planographic printing original plate for plate making - Google Patents

Abstract

PURPOSE:To eliminate the printing stains generated in a place corresponding to the ends of the printing plate in the case of printing on rolled paper by using such a rotary press for news printing. CONSTITUTION:The end face of the electrophotographic planographic printing original plate for plate making is coated and provided with (1) a layer contg. at least a fluorine-contg. compd., (2) an aq. soln. contg. the silicate expressed by general formula mSiO2/nM2O (M denotes an alkaline metal atom, m/n=0.5 to 8.5) and a hydrophilic resin and further, a layer (3) contg. at least the fluorine-contg. compd. is desensitized thereon and further, a layer contg. at least the fluorine-contg. compd. is provided thereon.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an electrophotographic lithographic printing original plate, which forms a printing plate by forming a toner image on a photoconductive layer and then removing non-image areas other than the toner image area, especially printing stains. The present invention relates to an electrophotographic lithographic printing original plate that provides a lithographic printing plate in which oxidation is prevented.

0002

[Prior Art] Today, as lithographic offset printing plates,
PS plates that use positive-working photosensitizers mainly composed of diazo compounds and phenolic resins, and negative-working photosensitizers mainly composed of acrylic monomers, etc., have been put into practical use, but all of these have low sensitivity, so Plate making is performed by contact exposure of a film original plate on which an image has been recorded. On the other hand, advances in computer image processing, large-capacity data storage, and data communication technology have meant that in recent years, everything from inputting, correcting, editing, and page layout to page layout can now be controlled by computers, and instant remote access is possible using high-speed communication networks and satellite communications. An electronic editing system that can output to a terminal plotter has been put into practical use. In particular, electronic editing systems are in high demand in the field of newspaper printing, which requires immediacy. Furthermore, even in the field where original manuscripts are currently stored in the form of film and printed versions are reproduced as needed based on this, with the development of large-capacity recording media such as optical discs, the original It is thought that data will be stored as digital data on these recording media.

However, direct printing plates that directly create printing plates from the output of a terminal plotter have hardly been put to practical use, and even in places where electronic editing systems are in operation, output is performed on silver halide photographic film, and this is not the case. The reality is that printing plates are created by contact exposure of PS plates. This is the light source of the output plotter (e.g. He
One of the reasons was that it was difficult to develop a direct printing plate with a sensitivity high enough to make a printing plate within a practical time using a -Ne laser, a semiconductor laser, etc.). Electrophotographic photoreceptors are considered as photoreceptors with high photosensitivity that can provide direct printing plates. As a method of producing a printing plate using electrophotography, a method is known in which a photoconductive layer in a non-image area is removed after forming a toner image. For example, Special Publication No. 37-17162, No. 38-6961, No. 38
-7758, 41-2426, 46-3940
No. 5, JP-A No. 50-19509, JP-A No. 50-19510
No. 52-2437, No. 54-145538, No. 54-134632, No. 55-105254, No. 5
No. 5-153948, No. 55-161250, No. 57
Examples include printing original plates for electrophotographic platemaking described in Japanese Patent No. 147656 and No. 57-161863. In the above method, it is necessary to remove the non-image area of the electrophotographic photoreceptor by etching to expose the hydrophilic surface, so it is necessary to use a binding resin that dissolves in an alkaline solvent or swells and detaches as the binding resin. There are many.

However, when printing using the printing plate obtained in this way, when printing on paper smaller than the size of the printing plate using a normal sheet-fed printing machine, There is no problem if the area to be printed does not become the printing surface, but when printing on a roll of paper using a rotary press such as for newspaper printing, printing smudges occur at the area corresponding to the edge of the printing plate. do. This stain is particularly noticeable when toner development is performed by reversal development.

[0005] An insulating resin layer is provided on the end face (side surface) of a lithographic printing original plate for electrophotographic plate making in order to prevent edge staining caused by a lithographic printing plate obtained by reverse development of a lithographic printing original plate for electrophotographic plate making. has been proposed (Unexamined Japanese Patent Publication No. 63-17
Publication No. 8240). In other words, one of the causes of printing stains caused by the lithographic printing plate obtained by reversing the lithographic printing original plate for electrophotographic platemaking as described above is that toner also adheres to the end surface of the lithographic printing original plate for electrophotographic platemaking during reversal development. However, it is believed that this area also gets ink during printing, causing printing stains, so an insulating resin is applied to the edge of the lithographic printing original plate for electrophotographic platemaking, and this area is coated with ink during reversal development. This is based on the idea of preventing toner from adhering. Furthermore, in JP-A-2-61654 and JP-A-2-66566, a water-soluble polymer layer or a resin layer having higher solubility in an alkaline solution than the resin of the photosensitive layer is provided on the end face. Proposed. However, the edges of planographic printing original plates are often cut with a cutter, and the cut surface is not smooth, so it is common for the resin to remain without dissolving, and the remaining resin is ink receptive. Also, printing stains occur on the edges. In order to prevent this, an effective proposal has already been made by the applicant. (Japanese Patent Application No. 1-159404, Japanese Patent Application No. 1-227398) The present invention is a further development of this.

[0006]

[Problems to be Solved by the Invention] The present inventors also used a lithographic printing plate obtained by forming a toner image by reversal development and removing the photoconductive layer in the non-exposed area by the above-mentioned means. We found that when printing newspapers, etc., printing stains were still observed on the edges, and after investigating the cause, we found that even if an insulating resin layer was provided as described above, toner hardly adhered to the edges. However, it was found that because the insulating resin layer itself remained on the end face, ink adhered to this area, resulting in printing stains. That is, by providing an insulating resin layer on the end surface, toner adhesion to the end surface during reversal development is certainly improved, but the newly provided insulating resin layer itself has lipophilic properties (i.e., It was found that if this remained, ink would adhere to the end surface and printing stains could not be prevented.

[0007]

[Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned drawbacks, the present inventors were able to completely prevent printing stains on the edge surface by the following method, and achieved the present invention. . That is, (1) a photoconductive layer is provided on a conductive support having a hydrophilic surface, and after at least imagewise exposure and toner development to form a toner image, the photoconductive layer in a non-image area other than the toner image area; An electrophotographic lithographic printing original plate for electrophotographic platemaking, which is made into a lithographic printing plate by removing the lithographic printing plate, characterized in that a layer containing at least a fluorine-containing compound is provided on an end surface of the lithographic printing original plate for electrophotographic platemaking. Planographic printing original plate for type plate making. (2) A photoconductive layer is provided on a conductive support having a hydrophilic surface, and after imagewise exposure and toner development to form a toner image, the photoconductive layer in non-image areas other than the toner image area is removed. In a lithographic printing original plate for electrophotographic plate making, which is made into a lithographic printing plate, the end surface of the planographic printing original plate for electrophotographic plate making has a general formula mSiO
2/nM2O (M is an alkali metal atom, m/n=0
．． 5 to 8.5) An aqueous solution containing a silicate represented by 5 to 8.5) and a hydrophilic resin is applied, and a layer containing at least a fluorine-containing compound is further provided thereon. Planographic printing original plate. (3) A photoconductive layer is provided on a conductive support having a hydrophilic surface, and after a toner image is formed by imagewise exposure and toner development, the photoconductive layer in non-image areas other than the toner image area is removed. In the lithographic printing original plate for electrophotographic plate making, which is preferably used as a lithographic printing plate, the end face of the planographic printing original plate for electrophotographic plate making is subjected to a desensitization treatment, and further a layer containing at least a fluorine-containing compound is provided thereon. The object of the present invention could be achieved by a lithographic printing original plate for electrophotographic platemaking characterized by the following characteristics.

The present invention will be explained in detail below. Various supports can be used as the conductive substrate of the electrophotographic printing original plate of the present invention. For example, plastic sheets with an electrically conductive surface or papers made especially solvent-impermeable and electrically conductive, aluminum plates, zinc plates or bimetallic plates such as copper-aluminum plates, copper-stainless steel plates, chrome-copper plates, or chrome-copper plates, etc. A conductive substrate having a hydrophilic surface such as a trimetal plate such as a copper-aluminum plate, a chromium-lead-iron plate, or a chromium-copper-stainless steel plate is used, and the thickness thereof is preferably 0.1 to 3 mm, particularly 0.1~0
．． 5 mm is preferred. Among these substrates, aluminum plates are preferably used. The aluminum plate used in the present invention is a plate-shaped body such as pure aluminum whose main component is aluminum or an aluminum alloy containing a small amount of foreign atoms, and its composition is not specified, and conventionally known and publicly used materials are used as appropriate. It can be used.

[0009] This aluminum plate can be used after being grained and anodized by a conventionally known method. Prior to the graining treatment, in order to remove rolling fat from the surface of the aluminum plate, degreasing treatment with a surfactant or an alkaline aqueous solution is performed, if desired, and then the graining treatment is performed. Graining 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, buff polishing, etc. can be used. Further, as an electrochemical roughening method, there is a method in which alternating current or direct current is used in a hydrochloric acid or nitric acid electrolyte. Furthermore, a method combining both methods can also be used, as disclosed in Japanese Patent Application Laid-Open No. 54-63,902.

[0010] The roughened aluminum plate is subjected to alkali etching treatment and neutralization treatment as necessary. The aluminum plate thus treated is anodized. As the electrolyte used in the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used, and the electrolyte and its concentration are appropriately determined depending on the type of electrolyte. The processing conditions for anodic oxidation vary depending on the electrolyte used, so they cannot be definitively specified, but generally 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 60 A. /dm2, voltage of 1 to 100 V, and electrolysis time of 10 seconds to 50 minutes. The amount of anodized film is preferably 0.1 to 10 g/m2, more preferably 1 to 6 g/m2.

[0011] As the photoconductive material used in the present invention, many conventionally known compounds can be used. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, N,N-vicarbasil derivatives, oxazole derivatives, styryl anthracene derivatives. , fluorenone derivatives, hydrazone derivatives, benzidine derivatives, stilbene derivatives, etc. Further, in addition to the above-mentioned low-molecular photoconductive compounds, the following high-molecular compounds can also be used. For example, vinyl polymers such as polyvinylcarbazole and its derivatives, polyvinylpyrene, polyvinylanthracene, poly-2-vinyl-4-(4'-dimethylaminophenyl)-5-phenyloxazole, poly-3-vinyl-N-ethylcarbazole, etc. Examples include polymers such as polyacenaphthylene, polyindene, copolymers of acenaphthylene and styrene, condensation resins such as pyrene-formaldehyde resin, bromopyrene-formaldehyde resin, and ethylcarbazole-formaldehyde resin. Furthermore, various pigments, sensitizing dyes, and the like can be used for the purpose of improving the sensitivity of the photoconductor and imparting a desired photosensitive wavelength range. Examples of these include monoazo, bisazo, trisazo pigments, phthalocyanine pigments such as metal phthalocyanines or metal-free phthalocyanines;
These include perylene pigments, indigo, thioindigo derivatives, quinacridone pigments, polycyclic quinone pigments, bisbenzimidazole pigments, squalium salt pigments, and azulenium salt pigments.

[0012] In addition, as a sensitizing agent, "sensitizer" 12
5 pages (Kodansha 81987), "Electronic Photography" Volume 12 9 (1
973) "Organic Synthetic Chemistry" Volume 24 No. 111010(
1966) and others can be used. Examples include pyrylium dyes, triarylmethane dyes, cyanine dyes, and styryl dyes. These can be used alone or in combination of two or more. In addition, if these charge generating agents have not only charge generating ability but also charge transporting ability, a photoreceptor can be prepared by dispersing and coating the charge generating agent in a binder as a basic material. can. That is, it is not necessarily necessary to use an organic photoconductive compound known as a charge transport agent. In the photoconductive layer of the present invention, for example, electron-withdrawing compounds such as trinitrofluorenone, chloranil, and tetracyanoethylene can be used for the purpose of improving sensitivity.

In the electrophotographic photoreceptor, 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 used in the photoconductive layer of the lithographic printing original plate for electrophotographic plate making of the present invention, resins known in the field of electrophotography can be used. To create a printing plate using an electrophotographic photoreceptor, it is necessary to finally remove the photoconductive layer in the non-image area, but this process depends on the solubility of the photoconductive layer in the etching solution or the toner image. It cannot be generalized because it depends on the relative relationship with the etching solution, such as resist properties. As the binding resin, a polymer compound that is soluble or dispersible in the etching solution described below is preferable.

Specifically, for example, a copolymer of styrene and maleic anhydride, a copolymer of styrene and monoalkyl maleic anhydride, a copolymer of methacrylic acid/methacrylic acid ester, styrene/methacrylic acid/methacrylate acid ester copolymer, acrylic acid/methacrylic acid ester copolymer, styrene/acrylic acid/methacrylic acid ester copolymer, vinyl acetate/crotonic acid copolymer,
Acrylic esters such as vinyl acetate/crotonic acid/methacrylic ester copolymers, methacrylic esters, styrene, vinyl acetate, etc., and acrylic acid, methacrylic acid,
Copolymers with carboxylic acid-containing monomers such as itaconic acid, crotonic acid, maleic acid, maleic anhydride, and fumaric acid or monomers containing acid anhydride groups, methacrylic acid amide, vinylpyrrolidone, phenolic hydroxyl groups, sulfonic acid groups, and sulfones. Examples include copolymers containing monomers having amide groups and sulfonimide groups, phenol resins, partially saponified vinyl acetate resins, xylene resins, and vinyl acetal resins such as polyvinyl butyral. 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.

The copolymer containing a monomer having an acid anhydride group as a copolymer component is preferably a copolymer of styrene and maleic anhydride. 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. preferable. Further, preferable 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 novolac resins obtained by condensing phenol, o-cresol, m-cresol, or p-cresol with formaldehyde or acetaldehyde under acidic conditions.

When using a photoconductive compound and a binding resin, the content of the photoconductive compound should be adjusted to 1% by weight of the photoconductive compound per 1 part by weight of the binding resin, since sensitivity decreases if the content of the photoconductive compound is small. is 0.05 parts by weight to 1.2 parts by weight,
More preferably, it can be used in a range of 0.1 part by weight to 1.0 part by weight. In addition, if the photoconductive layer of the present invention is too thin, it will not be possible to charge the surface potential necessary for development, and conversely, if the photoconductive layer is too thick, it will be difficult to remove the photoconductive layer in the planar direction called side etching. 0.1 to 30μ, preferably
It can be used with a thickness of 0.5 to 10μ. The electrophotographic printing plate of the present invention can be obtained by coating a photoconductive layer on a conductive substrate according to a conventional method. When creating a photoconductive layer, methods are known in which the components constituting the photoconductive layer are contained in the same layer, or a method in which a charge carrier generating substance and a charge carrier transporting substance are separated into different layers. , can be created using either method.

The coating solution is prepared by dissolving each component constituting the photoconductive layer in a suitable solvent. When using components that are insoluble in solvents such as pigments, use a dispersing machine such as a ball mill, paint shaker, Dyno Mill, or Attritor to reduce the particle size to 5 μm.
It is used by dispersing it to ~0.1μ. 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 coated onto a substrate by a known method such as spin coating, blade coating, knife coating, reverse roll coating, dip coating, rod bar coating, or spray coating and is dried to form a printing plate for electrophotolithography. can be obtained. 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.

In addition to a photoconductive compound and a binding resin, the photoconductive layer of the lithographic printing original plate for electrophotographic platemaking of the present invention contains a plasticizer, if necessary, in order to improve the flexibility of the photoconductive layer and the condition of the coated surface. Agents, surfactants, matting agents, and other various additives can be added. These additives can be contained within a range that does not deteriorate the electrostatic properties and etching properties of the photoconductive layer. In the lithographic printing original plate for electrophotographic platemaking of the present invention, if necessary, the adhesiveness between the conductive substrate and the photoconductive layer;
An intermediate layer can be provided for the purpose of improving the electrical properties, etching properties, printing properties, etc. of the photoconductive layer.

Examples of the intermediate layer include casein, polyvinyl alcohol, ethyl cellulose, phenolic resin,
Styrene-maleic anhydride resin, polyacrylic acid, monoethanolamine, diethanolamine, triethanolamine, tripropanolamine, triethanolamine and their hydrochlorides, oxalates, phosphates, aminoacetic acid, monoaminomonocarbons such as alanine acid, serine,
Oxyamino acids such as threonine and dihydroxyethylglycine, amino acids containing sulfur such as cysteine and cystine, monoaminodicarboxylic acids such as aspartic acid and glutamic acid, diaminomolcarboxylic acids such as lysine, p-hydroxyphenylglycine, phenylalanine, anthranilic acid, etc. tryptophan, an amino acid with an aromatic nucleus of
Amino acids with heterocycles such as proline, sulfamic acid,
Aliphatic aminosulfonic acids such as cyclohexylsulfamic acid, ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, hydroxyethyliminodiacetic acid, hydroxyethylethylenediaminetriacetic acid, ethylenediaminediacetic acid, cyclohexanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycol ether Diaminetetraacetic acid, etc. (
Poly)aminopolyacetic acid and one of the acid groups of these compounds
Part or all of the salts can include sodium salts, potassium salts, ammonium salts, and the like.

Furthermore, an overcoat layer that can be removed during etching of the photoconductive layer is provided on the photoconductive layer, if necessary, for the purpose of improving the electrical properties of the photoconductive layer, image properties during toner development, adhesion with toner, etc. be able to. This overcoat layer may be mechanically matted or a resin layer containing a matting agent. As matting agents, silicon dioxide, zinc oxide, titanium oxide, zirconium oxide, glass particles, alumina, starch, resin particles (for example, polymethyl methacrylate, polystyrene, phenolic resin, etc.) and U.S. Pat. No. 2,710,245, U.S. Pat.
The matting agent described in No. 992101 is 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, celluloses (e.g., viscose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, etc.), starches (e.g., soluble starch, modified starch, etc.) )
, polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyacrylamide, polyvinylymethyl 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.

The compound containing at least fluorine formed at the end portion, which is a feature of the present invention, will be explained. Fluorine-containing compounds include tetrafluoroethylene resin, tetrafluoroethylene/hexafluoropropylene copolymer resin, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene/ethylene copolymer resin, trifluoride Examples include fluorine-containing polymers such as ethylene chloride resin, vinylidene fluoride resin, vinyl fluoride resin, trifluorochloroethylene/ethylene copolymer resin, and various oligomers. Also, perfluoroalkyl carboxylate, perfluoroalkyl sulfonate, perfluoroalkyl phosphate, perfluoroalkyl quaternary
grade ammonium salt, perfluoroalkyl betaine, perfluoroalkyl amine oxide, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl group/hydrophilic group-containing oligomer, perfluoroalkyl group/lipophilic group-containing oligomer, perfluoroalkyl group/ Anions, cations, etc. of hydrophilic group/lipophilic group-containing oligomers, perfluoroalkyl group/lipophilic group-containing urethanes, perfluoroalkyl group/hydrophilic group-containing urethanes,
Examples include various amphoteric and nonionic fluorine-containing surfactants. Specifically, Dainippon Ink Chemical (
Megafac F-110, F-113, F-12 manufactured by Co., Ltd.
0, F-812, F-142D, F-144D, F-1
50, F-171, F-173, F-177, F-18
3, F-191, F-824, F-833, 3M Florado FC-95, FC-98, FC-128, FC
-143, FX-161, FC-134, FC-170
, FC-176, FC-430, FC-431, S-111, S-112, S-113, S-1 manufactured by Asahi Glass Co., Ltd.
21, S-132, S-133, S-141, S-14
5. Unidyne DS-10, DS manufactured by Daikin Industries, Ltd.
-102, DS-202, DS-301, DS-401
, DS-402, DS-501, DS-502, and the like. These fluorine-containing compounds may be used alone or in combination of two or more. Moreover, it is also possible to use it by mixing it with other various resins if necessary. Many resins can be used as the resin, but when the fluorine compound-containing layer is used alone, it is preferable to dissolve it in water or an etching solution, and it is recommended to use the resins listed below under silicate and water-soluble resin solution. suitable. In addition, when overlapping a fluorine compound-containing layer, a silicate layer, a water-soluble resin layer, or a desensitized layer, using an insulating resin in addition to the above resins will reduce toner adhesion during reversal development, making it more suitable for use. can do.

[0022] In the coating solution for the fluorine-containing compound layer of the present invention, additives such as various surfactants can also be used to improve coating properties. For example, anionic surfactants,
There are nonionic surfactants, amphoteric surfactants, and cationic surfactants. Anionic surfactants include fatty acid salts,
Alkylbenzene sulfonates, linear alkylbenzene sulfonates, alkyl sulfates, α-olefin sulfonates, alkyl phosphate ester salts, dialkyl sulfosuccinate ester salts, polyoxyethylene alkyl ether, sulfates, polyoxyethylene alkyl ether phosphorus Examples include acid salts, alkylnaphthalene sulfonates, N-lauroylsarcosine salts, sulfonic acids of naphthalene-formalin condensates, diphenyl ether disulfonates, and the like. Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene, polyoxypropylene block polymers, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyethylene glycol These include fatty acid esters, polyoxyethylene fatty acid amines, fatty acid monoglycerides, sorbitan fatty acid esters, pentaerythritol fatty acid esters, sucrose fatty acid esters, and amine oxides.

Examples of amphoteric surfactants include alkylcarboxybetaine types, alkylaminocarboxylic acid types, and alkylimidazoline types. Examples of cationic surfactants include tetraalkylammonium salts, trialkylbenzylammonium salts, and alkylimidazolinium salts. Other examples include silicone surfactants. Two or more of these surfactants can also be used in combination. Although the amount used is not particularly limited, the preferred range is 0.01 to 10% by weight of each treatment liquid.

In the present invention, a fluorine-containing compound is applied to the cut surfaces of the lithographic printing original plates for electrophotographic platemaking obtained as described above cut to a predetermined size and stacked in large numbers. Although it is preferable for mass production to treat a large number of sheets in a stacked manner, it is also possible to apply the coating to the end face of each sheet.

[0025] Examples of methods for applying the fluorine-containing compound include applying with a brush, sponge, roller, etc.
It can be applied by conventionally known methods such as spray application. The fluorine compound is applied after being dissolved, emulsified or dispersed in water or various organic solvents. Organic solvents that can be used include halogenated hydrocarbons such as dichloromethane, dichloroethane, and chloroform, alcohols such as methanol and ethanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and glycols such as ethylene glycol monomethyl ether and 2-methoxyethyl acetate. Examples include ethers, ethers such as tetrahydrofuran and dioxane, and esters such as ethyl acetate and butyl acetate.However, in order to not adversely affect the photosensitive layer when coating on the edge surface, organic solvents or water that do not dissolve the photosensitive layer are used. is preferably used. Furthermore, the edge surface to be coated varies depending on the usage pattern of the printing plate. If only one end surface of the printing plate will be used as the printing surface, it is sufficient to coat only that end surface, but assuming various usage patterns, , preferably on two opposing end faces, most preferably on the outer end faces (i.e., on all four sides).

In the present invention, below the layer containing the fluorine-containing compound, a compound having the general formula mSiO2 /nM2O
An aqueous solution containing a silicate represented by (M is an alkali metal atom, m/n=0.5 to 8.5) and a water-soluble resin may be applied. In the present invention, sodium silicate, potassium silicate, lithium silicate, etc. can be used as the silicate. mSiO2 /nM2 used in the present invention
The molar ratio m/n of O is preferably 0.5 to 8.5.

Examples of hydrophilic resins that can be used in the present invention include the following. For example, natural polymers include starches such as kansho starch, potato starch, tapioca starch, wheat flour starch, and corn starch; those obtained from algae such as carrageenan, laminaran, seaweed mannan, funori, Irish moss, agar, and sodium alginate; Trolo mallow, mannan, quince seed, pectin, gum tragacanth, gum karaya,
Plant mucilages such as xanthine gum, guarbing gum, locust bingham, gum arabic, calops gum and benzoin gum, homopolysaccharides such as dextran, glucan and levan, and heteropolysaccharides such as succinoglucan and santhan gum are produced by microbial fermentation. Examples include mucilage, glue, gelatin, casetin, and proteins such as collagen. In addition to alginate propylene glycol ester, which is a semi-natural product (semi-synthetic product), fibers such as viscose, methylcellulose, ethylcellulose, methylethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose, and hydroxypropylmethylcellulose phthalate are used. Can be used for basic derivatives and processed starches.

Processed starches include roasted starches such as white dextrin, yellow dextrin, and British gum, enzyme-modified dextrins such as enzyme dextrin and Schardinger dextrin, acid-decomposed starches as shown in solubilized starch, and oxidized starches as shown in dialdehyde starch. Starch, pregelatinized starch such as modified pregelatinized starch and unmodified pregelatinized starch, esterified starch such as phosphate starch, fatty starch, sulfate starch, nitrate starch, xanthate starch and carbamate starch, carboxylalkyl starch, hydroxyalkyl starch Starch, etherified starch such as sulfoalkyl starch, cyanoethyl starch, allyl starch, benzyl starch, carbamylethyl starch and dialkylamino starch, methylol cross-linked starch, hydroxyalkyl cross-linked starch, phosphoric acid cross-linked starch and dicarboxylic acid cross-linked starch, etc. Cross-linked starch, starch polyacrylamide copolymer, starch polyacrylic acid copolymer, starch polyvinyl acetate copolymer, starch polyacrylonitrile copolymer, cationic starch polyacrylic acid ester copolymer, cationic starch vinyl polymer copolymer Examples include starch graft copolymers such as starch polystyrene maleic acid copolymers and starch polyethylene oxide copolymers. In addition to polyvinyl alcohol, synthetic products include partially acetalized polyvinyl alcohol, allyl-modified polyvinyl alcohol, modified polyvinyl alcohols such as polyvinyl methyl ether, polyvinylethyl ether, and polyvinyl isobutyl ether, sodium polyacrylate, partially saponified polyacrylic esters, Partially saponified polyacrylic acid ester copolymers, polyacrylic acid derivatives and polymethacrylic acid derivatives such as polymethacrylate and polyacrylamide, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, copolymers of polyvinylpyrrolidone and vinyl acetate , carboxyvinyl polymer, styrene maleic acid copolymer, styrene crotonic acid copolymer, and the like.

In the aqueous solution of silicate and hydrophilic resin used in the present invention, the hydrophilic resin accounts for about 1% by weight of the total composition weight.
to about 30% by weight, preferably from about 3% to about 25% by weight. When the content is less than 1% by weight, the effectiveness of use decreases, and when it is more than 30% by weight, the viscosity increases and handling becomes difficult. These hydrophilic resins may be used alone or in combination of two or more.

As the desensitizing liquid used in the present invention, an aqueous solution containing a hydrophilic polymer compound can be effectively used. As specific hydrophilic polymers, various hydrophilic resins described in the above-mentioned silicate and hydrophilic resin solution can be used. It is preferable that the desensitizing liquid of the present invention further contains a metal salt of a strong acid, so that the desensitizing effect can be further enhanced. Specific examples of metal salts of strong acids include salts of sodium, potassium, magnesium, calcium, or zinc such as nitric acid, sulfuric acid, or chromic acid, sodium fluoride, and potassium fluoride.

When a metal salt of a strong acid is used in the desensitizing solution of the present invention, it is preferably used within a pH range of 1 to 5, more preferably 2 to 4.5. The desensitizing liquid used in the present invention is composed of an aqueous solution of a hydrophilic polymer compound as described above, and for example, US Pat. No. 4,253,999,
Emulsified desensitizing liquids described in specifications such as 4268613 and 4348954 can also be used.

In the present invention, as described above, a desensitizing treatment liquid or a liquid containing a silicate and a water-soluble resin is applied to the end face of a lithographic printing original plate for electrophotographic plate making, and after drying, a Apply a layer containing fluorine compounds. The amount of the desensitizing treatment liquid or the liquid containing silicate and water-soluble resin applied to the end face is preferably in the range of about 50 to 150 g/m 2 .

[0033] A lithographic printing plate can be produced using the lithographic printing original plate for electrophotographic engraving of the present invention by a 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, He--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 development method, conventionally known methods such as cascade development, magnetic brush development,
Various methods such as 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. Further, either a normal development method in which toner is attached to non-exposed areas or a reverse development method in which toner is attached to exposed areas can be used as appropriate.

The formed toner image can be fixed by a known fixing method, such as heat fixing, pressure fixing, solvent fixing, or the like. A lithographic 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.

As the etching solution for removing the photoconductive insulating layer in the toner non-image area after toner image formation, any solvent can be used as long as it can remove the photoconductive insulating layer, and there are no particular limitations. However, preferably alkaline solvents are used. The alkaline solvent referred to herein is an aqueous solution containing an alkaline compound, an organic solvent containing an alkaline compound, or a mixture of an aqueous solution containing an alkaline compound and an organic solvent.

Examples of alkaline compounds include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, sodium phosphate, potassium phosphate, ammonia, and monoethanolamine, Any organic or inorganic alkaline compounds such as amino alcohols such as diethanolamine and triethanolamine can be mentioned. As described above, water or many organic solvents can be used as the solvent for the etching solution, but from the viewpoint of odor and pollution, an etching solution mainly composed of water is preferably used.

[0037] If necessary, various organic solvents can be added to the etching solution mainly composed of water. Preferred organic solvents include lower alcohols and aromatic alcohols such as methanol, ethanol, propanol, butanol, benzyl alcohol, and phenethyl alcohol, as well as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, cellosolves, and monoethanolamine, diethanolamine, Examples include amino alcohols such as triethanolamine. Further, the etching solution may contain a surfactant, an antifoaming agent, and various other additives as necessary. In the present invention, the toner forming the image area is not particularly limited as long as it has resistivity to the etching solution, but generally,
It is preferable that the resin component contains a resisting resin component to the etching solution.

Examples of the resin component include methacrylic acid,
Acrylic resins using acrylic acid and their esters, vinyl acetate resins, copolymer resins such as vinyl acetate and ethylene or vinyl chloride, vinyl chloride resins, vinylidene chloride resins, vinyl acetal resins such as polyvinyl butyral, polystyrene, styrene, etc. Copolymer resins such as butadiene and methacrylic acid esters, polyethylene, polypropylene and their chlorinated products, polyester resins (e.g., polyethylene terephthalate, polyethylene isophthalate, polycarbonate of bisphenol A, etc.), phenolic resins, xylene resins, alkyd resins, vinyl-modified alkyds Examples include resins, gelatin, cellulose ester derivatives such as carboxymethylcellulose, wax, polyolefin, and wax.

[0039]

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. Example 1 The surface of a JIS1050 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 2 . After washing with water, it was neutralized by immersing it in a 30% nitric acid aqueous solution for 1 minute, and was thoroughly washed with water. Then 0.
In a 7% nitric acid aqueous solution, a rectangular alternating waveform with an anode voltage of 13 volts and a cathode voltage of 6 volts was used.
No. 9191) Electrolytic surface roughening was performed for 20 seconds, and the surface roughened by 20%.
The surface was cleaned by immersing it in a 50°C solution of sulfuric acid, and then washed with water. Further, the substrate was anodized in a 20% aqueous sulfuric acid solution so that the weight of the anodic oxide film was 3.0 g/m2, washed with water, and dried to prepare a substrate.

The following photoconductive layer coating solution (1) was applied onto this substrate.
) was coated with a bar coater and dried at 120° C. for 10 minutes to prepare a printing plate for electrophotolithography. Coating liquid for photoconductive layer (1) ε-type copper phthalocyanine (Lio manufactured by Toyo Ink Co., Ltd.)
photon-ERPC)

1.0 parts Copolymer of benzyl methacrylate and methacrylic acid (30 mol% methacrylic acid)

10.0 parts Tetrahydrofuran

48.0 parts cyclohexanone

16.0 copies or more 3
A dispersion liquid for a photoconductive layer was prepared by dispersing the mixture together with glass beads in a 00 ml glass container using a paint shaker (Toyo Seiki Seisakusho Co., Ltd.) for 60 minutes.

The dry film thickness of the electrophotographic printing plate thus prepared was 4 μm. This electrophotographic photoreceptor was stacked by laminating paper with a weight of 50 g/m2 on one side with 10 μm of polyethylene so that the polyethylene side of the paper was in contact with the photosensitive layer, and then cut with a guillotine cutter. A spray (manufactured by Fluon Kogyo Co., Ltd.) was applied and dried at 120°C for 5 minutes to form a fluorine-containing compound layer. Next, this sample was charged to a surface potential of +400 V with a corona charger in a dark place, and then a negative image was exposed to tungsten light, and this sample was placed in 1 liter of Isopar H (Esso Standard) with polymethyl methacrylate particles (particle size 0). +3 using a liquid developer prepared by dispersing 5g of .3μ) as toner particles and adding 0.01g of zirconium naphthenate as a charge control agent.
By applying a bias voltage of 00 V to the counter electrode and performing reversal development, a clear positive image could be obtained. Further, the created image was heated at 120° C. for 2 minutes to fix the toner image.

This non-image area was removed 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, and thoroughly washed with water.
Next, gum liquid (Fuji Photo Film PS version gum GU-
7) was applied to create an offset printing plate. When this printing plate was set in an offset printing machine and printing was performed, all of the obtained prints were good prints with no stains at all even in the portions corresponding to the edges of the printing plate.

Comparative Example 1 A printing plate was prepared in exactly the same manner as in Example 1 except that a layer containing a fluorine compound was not provided on the end face. When printing was carried out in the same manner as in Example 1 using this printing plate, the image area of the obtained print was a good print with no stains, but there were streaks in the portion corresponding to the edge of the printing plate. This resulted in staining and was not suitable for practical use.

Comparative Example 2 Instead of providing a layer containing a fluorine compound on the end face in Example 1, a 3 μm layer containing a copolymer of isobutyl methacrylate and methacrylic acid (molar ratio: 8:2) was used as an insulating resin. A printing plate was prepared in exactly the same manner except that the layers were formed. When printing was carried out in the same manner as in Example 1 using this printing plate, the image area of the obtained print was a good print with no stains, but there were streaks in the portion corresponding to the edge of the printing plate. This resulted in staining and was not suitable for practical use.

Example 2 In Example 1, instead of using Teflon spray (manufactured by Flon Industries Co., Ltd.), a fluorine-based oligomer compound S was used.
A 5% ethyl acetate solution of -381 (manufactured by Asahi Glass Co., Ltd.) was applied and dried at 100°C for 5 minutes to prepare a lithographic printing original plate for electrophotographic platemaking in the same manner as in Example 1, plate making, and printing. As a result, all of the obtained printed matter were good, with no stains at all even in the portions corresponding to the edges of the printing plates.

Example 3 An electrophotographic photoreceptor on which a photoconductive layer was formed in the same manner as in Example 1 was laminated with 10 μm polyethylene on one side of paper weighing 50 g/m 2 so that the polyethylene side of the interleaving paper was in contact with the photosensitive layer. After sandwiching and stacking them and cutting them with a guillotine cutter, the following hydrophilic resin solution containing silicate was applied to the outer peripheral end surface with a sponge in a coating amount of about 70 g/m 2 and dried at room temperature. Hydrophilic resin solution containing silicate Hydroxypropyl etherified starch (degree of substitution 0.0
5) 60 parts potassium silicate solution (52Be': 20°C)
18 parts Potassium hydroxide (
48.5%)
Part 8 Pure water


914 parts Next, a solution having the following composition was applied to the end face and dried at 100°C for 10 minutes. Resin solution containing fluorine-containing compound Megafac F-177 (manufactured by Dainippon Ink Co., Ltd.)
10 parts Butyl methacrylate/methacrylic acid (molar ratio 6/4)
90 parts ethyl acetate

900 copies

00
47] Next, this sample was plate-made in the same manner as in Example 1, and the obtained printing plate was set in an offset printing machine and printing was performed. All of the obtained prints corresponded to the edges of the printing plate. The printed matter was also in good condition with no stains at all.

Example 4 Instead of applying the silicate-containing hydrophilic resin in Example 1, the following desensitizing treatment solution was applied by spray coating at a coverage of about 70 g/m2, and the coating was heated at room temperature. Dry. Desensitizing treatment liquid 30% gum arabic aqueous solution

Part 61 Water

30 parts Sodium hexametaphosphate
0.7 parts
sodium nitrate

1.0 part magnesium sulfate

1.2 parts 85% phosphoric acid

2.4
Part: Polyoxyethylene polyoxypropylene block copolymer (trade name: Bluronic)
1.
Apply 2 parts of the solution with the following composition to the end face and heat at 100°C.
Dry for 10 minutes. Resin solution containing fluorine-containing compound Megafac F-170 (manufactured by Dainippon Ink Co., Ltd.)
10 parts Vinyl acetate resin (RESYN28-2930 Kanebo ・
Manufactured by NSC Co., Ltd.)
90 parts ethyl acetate

900 copies Next, this sample was plate-made in the same manner as in Example 1, and the resulting printing plate was set in an offset printing machine and printed. All of the resulting prints corresponded to the edges of the printing plate. The printed matter was also in good condition with no stains at all.

Example 5 A printing original plate for electrophotographic plate making was prepared in exactly the same manner as in Example 1, except that the following photoconductive coating liquid (2) was used instead of photoconductive coating liquid (1). Coating liquid for photoconductive layer (2) Trisazo compound

1.0 copy

[0050]

[Chemical formula 1]

Oxazole compound shown below
2.
5th part

[0052]

[Case 2]

Copolymer of vinyl acetate and crotonic acid (RESYN
No. 28-1310 Manufactured by Kanebo NSC Co., Ltd.)

10 parts Tetrahydrofuran

100 copies for 500m
The mixture was placed in a glass container 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 approximately 4 μm. In the same manner as in Example 3, a hydrophilic resin solution (C) containing the following silicate was applied to the outer peripheral end face at a coating amount of 50 g/m2. Hydrophilic resin solution containing silicate Cream dextrin with water soluble content of 95% by weight or more (
Cream dextrin #3, manufactured by Matsutani Chemical Co., Ltd.) 100 parts Potassium silicate (52Be': 20°C)
20 parts Potassium hydroxide (48.5%)
10 copies
Sodium isopropyl naphthalene sulfonate
Part 5 Pure water


865 parts Next, a solution having the following composition was applied thereon and dried. Resin solution containing fluorine-containing compound Megafac F-183 (manufactured by Dainippon Ink Co., Ltd.)
10 parts ethyl acetate

900 copies

Next, this sample was charged to a surface potential of +400 V with a corona charger in a dark place, and then a positive image was exposed to tungsten light, and a liquid developer Ricoh MRP (
By developing the film (bias voltage +50 V) with Ricoh Co., Ltd., a clear positive image could be obtained. Further, the created image was heated at 120° C. for 2 minutes to fix the toner image. This non-image area was immersed for 10 seconds in an etching solution prepared by diluting DN-3C (Fuji Photo Film's developer for PS plates) with water at a ratio of 1:2, and then thoroughly washed with water.
Apply Fuji Photo Film's PS plate gum GU-7),
Created an offset printing plate. When this printing plate was set in an offset printing machine and printing was performed, all of the obtained prints were good prints with no stains at all even in the portions corresponding to the edges of the printing plate.

Example 6 A printing plate was prepared in exactly the same manner as in Example 5, except that the following desensitizing solution water-soluble resin solution was used instead of the silicate-containing hydrophilic resin solution. All of the obtained prints were good prints with no stains at all even in the portions corresponding to the edges of the printing plates. Desensitization treatment liquid Carboxymethylated starch (carboxymethyl group introduction rate 0.2)

100 parts Potassium silicate (52Be
': 20℃)
20 parts potassium hydroxide (48.
5%)
10 parts Sodium isopropylnaphthalene sulfonate
Part 5 Pure water

865 copies

[0057]

[Effects of the Invention] As described above, by providing a layer containing at least a fluorine-containing compound on the end face of a lithographic printing original plate for electrophotographic platemaking, it is possible to print on a roll of paper using a rotary press such as a newspaper printing machine. In this case, it was possible to eliminate printing stains that occurred at the edges of the printing plate.

Claims (3)

[Claims] 1. A photoconductive layer is provided on a conductive support having a hydrophilic surface, and after a toner image is formed by at least imagewise exposure and toner development, the photoconductive layer is formed in a non-image area other than the toner image area. An electrophotographic lithographic printing original plate for electrophotographic platemaking, which is made into a lithographic printing plate by removing the lithographic printing plate, characterized in that a layer containing at least a fluorine-containing compound is provided on an end surface of the lithographic printing original plate for electrophotographic platemaking. Planographic printing original plate for type plate making. 2. A photoconductive layer is provided on a conductive support having a hydrophilic surface, and after a toner image is formed by imagewise exposure and toner development, the photoconductive layer in non-image areas other than the toner image area is removed. In a lithographic printing original plate for electrophotographic plate making which is made into a lithographic printing plate by removal, a compound having the general formula mSiO2 /nM2O(
M is an alkali metal atom, m/n = 0.5 to 8.5) An aqueous solution containing a silicate and a hydrophilic resin is applied, and a layer containing at least a fluorine-containing compound is further applied thereon. A lithographic printing original plate for electrophotographic platemaking, which is characterized by: 3. A photoconductive layer is provided on a conductive support having a hydrophilic surface, and after a toner image is formed by imagewise exposure and toner development, the photoconductive layer in non-image areas other than the toner image area is removed. In a lithographic printing original plate for electrophotographic plate making which is made into a lithographic printing plate by removal, the end face of the planographic printing original plate for electrophotographic plate making is subjected to a desensitization treatment, and further thereon, a layer containing at least a fluorine-containing compound is provided. A lithographic printing original plate for electrophotographic platemaking, characterized by being provided with.