JPH03294871A - Plate making method for electrophotographic printing plates - Google Patents

Abstract

PURPOSE:To more stably produce a large quantity of printing plates over a long period of time by making the plates by using a rinsing liquid which contains a mono mer having at least a carboxyl group in a monomer constituting a binder resin and in adjusted in liquid pH to the max. value of the acid dissociation constant of the monomer having the carboxyl group or above. CONSTITUTION:The rinsing liquid to be used is adjusted in the liquid pH to the max. value of the acid dissociation constant in the monomer having the carboxyl group constituting the binder resin in the photoconductive layer of the electrophotographic planographic printing plate to be subjected to plate making processing or above. Namely, the binder resin flowing in together with the washing liquid having the liquid pH above neutrality can maintain the soluble state at least during the liquid circulating and plate passage if the pH of the rinsing liquid is at least above the max. value of the individual acid dissociation constants of the monomer group having the carboxyl groups constituting >=1 kinds of the binder resin used for the photoconductive layer of the electrophotographic planographic printing plate. The trouble by the reinsolubilization of the binder resisn is prevented in this way and, therefore, the printing of many sheets is possible without generating troubles, such as print staining.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a plate-making method for an electrophotographic printing plate drawn by an electrophotographic method, and more specifically, after bringing the planographic printing plate into contact with an eluent using an automatic elution machine, washing treatment with water and subsequent rinsing treatment are performed. This invention relates to a method for making electrophotographic printing plates.

[Prior art and its problems]

Conventionally, as lithographic offset printing plates, 28 plates have been put into practical use, using positive-working photosensitizers whose main components are diazo compounds and phenolic resins, and negative-working photosensitizers whose main components are acrylic monomers and prepolymers. However, all of these have low sensitivity, and plate making is performed by contact exposure of a silver salt photographic film original plate on which an image has been recorded in advance. On the other hand, with the development of computer image processing, large-capacity data storage, and data communication technology, in recent years, everything from inputting, correcting, editing, and layout of manuscripts to page setting has become fully computer-controlled, and can be done instantly using high-speed communication networks and satellite communications. An electronic editing system that can output to a terminal plotter in a remote location has been put into practical use. This electronic editing system is particularly in high demand in the field of newspaper printing, which requires immediacy. Furthermore, even in fields where originals are preserved in the form of original film, and printing plates are reproduced as needed based on this, with the development of ultra-high capacity recording media such as optical discs, these originals are It is conceivable that information will be stored as digital data on recording media. However, direct printing plates, in which printing plates are produced directly from the output of a terminal plotter, have hardly been put into practical use, and even in places where electronic editing systems are in operation, output is made on silver halide photographic film, which is then used as a base. In reality, printing plates are created indirectly by contact exposure to PS plates. This has led to the development of direct printing plates that are sensitive enough to produce printing plates within a practical amount of time using output professional light sources (e.g., I (e-Ne laser, semiconductor laser, etc.)). Now, an electrophotographic photoreceptor can be considered as a photosensitive material with high photosensitivity that can provide a direct printing plate. Conventionally, as a printing plate material (printing original plate) using electrophotography, for example, Special Publication No. 47-47610, No. 48-18325,
Photoconductive zinc oxide/resin dispersion offset printing plate materials described in JP 48-40002 and JP 51-15766 are known; After being wetted with a desensitizing treatment liquid (for example, an acidic aqueous solution containing iron hexacyano salt or inosit hexaphosphate) to make it oil-insensitive, it is subjected to printing. However, offset printing plates treated in this way have a printing durability of about 10,000 sheets at most.
In terms of good print image reproducibility, it is not suitable for further printing, and if a composition with enhanced desensitization is used, it has drawbacks such as deterioration of image quality. On the other hand, Japanese Patent Publication Nos. 37-17162, 38-7758, 41-2426, 46-39405, 50-19509, 52-2437, 54-1
No. 34632, No. 54-145538, No. 55-15
No. 3948, No. 57147656, No. 57-1618
Printing plate materials based on organic photoconductive compounds and alkali-soluble binder resins, such as those described in Japanese Patent No. 63, are also known. These electrophotographic photoreceptors are generally mounted on aluminum substrates, and if the aluminum plate and photoconductive layer (binder) are firmly bonded, they can essentially have printing durability equivalent to PS plates. have A general plate-making method for these alkali-soluble electrophotographic printing plates is to form a toner image on an electrophotographic printing original plate using a photoconductive compound by a known electrophotographic image forming method, and then form a toner image in the toner image area. By treating the other non-image areas with a solution containing an alkaline agent, etc., the photoconductive layer in the non-image area is dissolved (so-called elution) from the plate, and generally the excess eluate and solubilized light are The conductive layer is removed from the plate using a washing liquid with a liquid pH of at least neutral, and then the apparent pH of the plate surface is adjusted using an acidic rinsing liquid.
If necessary, a plate surface protection liquid (protective gum liquid) is applied and the plate is made. The alkali-soluble binder resin used in this alkali-soluble electrophotographic printing plate does not exhibit permanent solubility in an aqueous solution in a solubilized state, and most of it becomes insolubilized again in a strongly acidic atmosphere. . Therefore, when this solubilized binder resin flows into the acidic rinsing liquid together with the washing water, the binder resin may precipitate depending on the pH of the rinsing liquid. In particular, when rinsing liquid is circulated and reused using an automatic elution machine, the precipitates that form in the rinsing liquid may clog the spray nozzle or adhere to pipes or liquid tanks, causing problems with liquid circulation. In addition, dust deposits may adhere to the non-image areas of the printing plate, resulting in
It was possible to induce

[Purpose of the invention]

An object of the present invention is to bring an electrophotographic printing plate drawn by an electrophotographic method into contact with an eluent, and then perform a water washing process and a subsequent rinsing process to prepare an electrophotographic printing plate. An object of the present invention is to provide an electrophotographic printing plate that does not generate insoluble matter or gel and can stably produce a large amount of printing plates over a long period of time, and further reduces the frequency of liquid exchange. An object of the present invention is to provide a plate-making method.

[Means to solve the problem]

The present invention involves forming a toner image by an electrophotographic method on an electrophotographic lithographic printing plate having a photoconductive layer made of at least a photoconductive compound and a binder resin on a conductive support, and then using an automatic elution machine. In the plate-making method for electrophotographic printing plates, which involves contacting with an alkaline eluent to solubilize non-image areas, followed by washing with water and subsequent rinsing, the monomer constituting the binder resin is This is achieved by plate making using a rinsing solution that contains at least a monomer having a carboxyl group and whose liquid pH is adjusted to be higher than the highest value of the acid dissociation constant (p Km ) of the monomer that has a carboxyl group. . The structure of the electrophotographic lithographic printing plate containing the binder resin in the photoconductive layer according to the present invention will be described in detail later, but the carboxyl resin according to the present invention constituting the binder resin in the photoconductive layer of the electrophotographic printing plate will be described in detail later. The monomers having groups (the acid dissociation constant: PKl is shown in parentheses) include acrylic acid (4,26),
methacrylic acid (4,66), and crotonic acid (4,69
), itaconic acid (3,85,5,45),
maleic acid (1,75,5,38), and fumaric acid (2
Examples include dibasic acids such as t85.4.10) and half esters thereof. The rinsing liquid according to the present invention has an acid dissociation constant (pKa) higher than the highest value of the carboxyl group-containing monomer constituting the binder resin in the photoconductive layer of the electrophotographic printing plate to be subjected to plate-making processing. The liquid pH has been adjusted. In other words, when the pH of the rinsing solution is at its minimum, the individual acid dissociation constants (p Ka ), at least during liquid circulation mail order, the binder resin that flows in with the washing liquid having a liquid pH of neutral or higher will remain in a solubilized state, and therefore the binder resin will be re-insolubilized. The above troubles can be prevented. However, even if only a small amount of the rinsing liquid flows into the protective gum liquid for the plate surface protection treatment that is normally performed afterwards, if the pH of the rinsing liquid is high, the pH of the protective gum liquid will inevitably rise quickly, and the plate surface protection will be prevented. Since the effect is also attenuated, it is desirable to maintain the pH of the rinsing liquid at 7 or less. Various test materials can be added to the rinse solution according to the present invention in order to adjust the pH of the solution. In particular, in order to more stably process a large number of electrophotographic lithographic printing plates using an automatic elution machine, etc., it is desirable that the pH of the rinsing liquid does not change during plate making for a large number of plates. It is desirable to contain at least one of water-soluble salts as an agent. As a result, when the rinsing liquid according to the present invention is applied to an electrophotographic lithographic printing plate, the basic components resulting from the eluate remaining on the plate are neutralized, and the non-image areas become more hydrophilic. For details on such buffering agents, see, for example, "Chemistry Handbook, Basic Edition ■" edited by the Chemical Society of Japan, February 20, 1972.
5th edition, published by Maruzen Co., Ltd., pages 1312 to 1320, and these can be applied as is. Also,
Suitable acids and water-soluble salts include inorganic acids such as molybdic acid, boric acid, nitric acid, sulfuric acid, phosphoric acid, and boric acid, acetic acid, benzoic acid, glycolic acid, lactic acid, propionic acid, oxalic acid, Water-soluble acids such as tartaric acid, amber acid, maleic acid, fumaric acid, malonic acid, phthalic acid, malic acid, glutaric acid, pimelic acid, adipic acid, citric acid, trimellitic acid, trimesic acid, p-toluenesulfonic acid, etc. Examples include acids such as organic acids and their salts. In the salt form, water-soluble alkali metal salts and ammonium salts are preferred. Among these,
More preferred acids and/or water-soluble salts include molybdic acid, boric acid, phosphoric acid, polyphosphoric acid, oxalic acid, tartaric acid, succinic acid, maleic acid, fumaric acid, malonic acid, phthalic acid, malic acid, glutaric acid, pimelic acid, adipic acid,
Polybasic acids such as citric acid and their alkali metal or ammonium salts, more preferably at least 4 of the above acids.
．． Those having an acid dissociation constant (11 Kl) of 5 to 6.0 can be suitably used in the rinse liquid according to the present invention. Examples of polybasic acids having an acid dissociation constant (pKa) of at least 4.5 to 6.0 include adipic acid, citric acid, glutaric acid, succinic acid, pimelic acid, maleic acid, malonic acid, malic acid, etc. can be mentioned. These acids and/or water-soluble salts can be used alone or in combination of two or more, and if desired, a suitable acid or alkali agent can be added to adjust the pH of the solution. The amount of these additions is not particularly limited, but the total amount of acid and water-soluble salt is 0.01 to 10
It is preferably used in a range of 0.05 to 5% by weight, more preferably 0.05 to 5% by weight. The rinsing liquid according to the present invention further includes:
It is preferable to contain a surfactant for the purpose of improving washability and protecting the printing plate. Examples of such surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyrylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, pentaerythritol fatty acid ester, polyoxyethylene sorbitan. fatty acid ester, glycerin fatty acid ester, acetylene diol,
Nonionic surfactants such as polyoxyethylene-added acetylene diol, fatty acid salts, abietates, alkanesulfonates, hydroxyalkanesulfonates, dialkylsulfosuccinates, alkylbenzenesulfonates, alkylnaphthalenesulfonates,
Alkylphenoxypolyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-alkyl sulfosuccinic acid monoamide salts, petroleum sulfonates, fatty acid alkyl ester sulfate ester salts, alkyl sulfate ester salts, polyoxyethylene alkyl Ether sulfate ester salts, polyoxyethylene alkyl phenyl ether sulfate ester salts, fatty acid monoglyceride sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkyl phenyl ether phosphate ester salts, styrene/ Anionic surfactants such as partially saponified maleic anhydride copolymers, partially saponified olefin/maleic anhydride copolymers, naphthalene sulfonate formalin condensates, alkylamine salts, quaternary ammonium salts, Examples include cationic surfactants such as polyoxyethylene alkylamine salts and polyoxyethylene polyamine derivatives, and amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfate esters, and imidacillins. Among the surfactants listed above, polyoxyethylene refers to polyoxymethylene,
Polyoxyalkylenes such as polyoxypropylene and polyoxybutylene can be substituted, and these surfactants are also included. The above surfactants can be used alone or in combination of two or more, and are used in the rinse solution in an amount of 0.001 to 10% by weight, more preferably 0.01 to 5% by weight. It is preferable that the rinsing liquid according to the present invention contains a lipophilic substance in order to improve the oil sensitivity of the image area of the printing plate and hasten the build-up of ink at the initial stage of printing. Lipophilic substances include oleic acid, lauric acid, valeric acid, nonylic acid,
Organic carboxylic acids having 5 to 25 carbon atoms, such as capric acid, myristic acid, and palmitic acid, and castor oil are preferable. These lipophilic substances can be used alone or in combination of two or more, and are used in the rinse solution in an amount of 0.005 to 10% by weight, more preferably 0.05 to 5% by weight. It is desirable that the washing liquid according to the present invention contains a preservative and/or a bactericidal agent. Examples of preservatives and fungicides include phenol, cresol, 0-phenylphenol, p-chloro-m-xyleno-Jl/, 2', 4'
Phenol compounds such as 5-trichloro-2-phenoxyphenol, glycine compounds such as alkylbis(aminoethyl)glycine and bis(alkylaminoethyl)glycine, guanidine compounds such as polyhexamethylene biguanidine, Carboxylic acids, esters, and their salts such as dehydroacetic acid and benzoic acid ester, hexahydro-1,
Triazine compounds such as 3,5-tris(2-hydroxyethyl)-s-triazine and hexahydro-135-triethyl-s-triazine, benzisothiazolone,
Isothiazolone compounds such as isothiazolone and derivatives thereof, imidazole compounds such as 2-(thiocyanomethylthio)benzimidazole, 4,5.6.7-tetrachloro-2-trifluoromethylbenzimidazole, perventazole, 2.3.5.Pyridine compounds such as 6-tetrachloro-4-methylsulfonylpyridine, amide compounds such as dithiobis(benzmethylamide), and other N, N-dimethyl-N'-phenyl-N
Examples include '-(fluorodichloromethylthio)-sulfamide, and isothiazolone-based, acid ester-based, and phenol-based compounds are particularly suitable. These preservatives and disinfectants can be used alone or in combination of two or more. When adding it to the washing liquid, it is preferable to dissolve it in water and a suitable organic solvent in advance. Further, these may be added prior to plate making, or may be added once or in several portions at a desired time. The amount added to the washing solution needs to be adjusted depending on the type of compound used (sterilizing power), the type of bacteria mixed in the washing solution, and its amount, but it is usually in the range of 1 to 30,000 ppm, more preferably 10 to 30,000 ppm.
It is preferable to use it within the range of 110,000 pp. Next, other processing liquids and the like related to the present invention will be explained. The eluent according to the present invention preferably contains an alkaline agent and has a buffering capacity. As an alkaline agent, -
Silicates expressed by the formula S i O2/M20 (M2N a . K), inorganic alkaline agents such as alkali metal hydroxides, alkali metal and ammonium salts of phosphoric acid and carbonic acid, ethanolamine, propanediamine, etc. Examples include organic alkaline agents such as amines, and mixtures thereof, but the silicates mentioned above are particularly advantageous because they exhibit a strong buffering ability. In terms of formulation, it is desirable to add an alkali metal hydroxide to this. The eluate according to the present invention preferably contains a surfactant in order to improve the wettability of the eluate to the surface of the photoconductive layer, thereby improving the elution ability, and expanding the elution treatment conditions. Examples of preferable surfactants include alkylbenzene sulfonates (the alkyl group has 8 to 18 carbon atoms, more preferably 12 to 16 carbon atoms), alkylnaphthalene sulfonate salts (the alkyl group has 3 to 10 carbon atoms) Anionic surfactants such as formalin condensates of naphthalene sulfonic acid, dialkyl sulfosuccinates (the alkyl group has 2 to 18 carbon atoms), dialkylamide sulfonates (the alkyl group has 11 to 17 carbon atoms), etc. , imidacillin derivatives, carboxybetaines, aminocarboxylic acids,
Examples include amphoteric surfactants such as sulfobetaines, aminosulfate esters, and imidacillins. The eluate further contains ionic compounds described in JP-A No. 55-25100, water-soluble cationic polymers described in JP-A-55-95946, and water-soluble amphoteric compounds described in JP-A-56-142528. Molecular electrolyte, JP-A-58-75
Neutral salt described in Publication No. 152, JP-A-58-190952
chelating agents described in JP-A-1-177541, preservatives and bactericidal agents described in JP-A-63-226657, U.S. Pat. No. 3,250,727, U.S. Pat. No. 1382901,
Known components such as the antifoaming agent described in Japanese Patent No. 1,387,713, and natural and synthetic water-soluble polymers can be contained as necessary. The solvent in the eluate is not particularly limited as long as it can stably disperse and dissolve the above components, but water, more preferably ion-exchanged water, is advantageously used. Further, in order to further stabilize the above components, a small amount of an organic solvent may be contained. Especially when using the above-mentioned silicate in an alkaline agent, Si
02/M20=0.5 to 8.5 (in terms of moles) is preferable. The pH of the eluate should be between 11.5 and 14°, more preferably between 12.0 and 13.5, and when the pH fluctuates during mail-order sales or aging of the eluate, add the desired replenisher at the appropriate time. It is desirable to improve the elution activity. The washing liquid according to the present invention has at least 7.0 to 10.
5 contains an organic compound having an acid dissociation index (pKa) to maintain its pH at 10.5 or lower. This organic compound (hereinafter, unless otherwise specified, acid dissociation index (pKa) of at least 7.0 to 10.5 according to the present invention)
) is simply referred to as an organic compound, and other organic compounds are referred to as organic substances to distinguish them. ), the washing process can be carried out sufficiently even with water that does not contain organic compounds at least at the beginning, so a liquid that does not contain organic compounds is used as the washing liquid at first, and it is added later to "finally" It may be contained in the washing solution, or it may be added to the washing solution prior to plate making. In the case of the former (post-addition), the addition starts when the pH of the washing solution is 8.
A range of 5 to 10.5, more preferably 9.5 to 10.0 is desirable. In addition, especially if the plate size is constant, the pH increase of the washing liquid is approximately proportional to the mail order amount (number of sheets) unless the area of the non-image area (eluted area) differs greatly. Organic compounds related to can be added. Even in the case of the latter (first addition), it is possible to add more in accordance with the rise in pH of the washing liquid during mail-order sales of a large number of sheets. Further, when adding the organic compound according to the present invention prior to plate making, the organic compound may be added alone, or may be used as a predispersed or dissolved organic compound in water. When preparing an aqueous solution, a small amount of an organic solvent may be added to promote dissolution. In particular, if the organic compound is a water-soluble solid, it may be immersed in a water washing tank so that it is gradually dissolved by liquid flow in the reverse plate or pH fluctuation. The pH of the washing liquid according to the present invention must always be kept at 10.5 or less, but at least the pH of the washing liquid containing organic compounds is 7.5 to 10.
It is desirable to keep it in the range of 5, more preferably in the range of 8.0 to 10.0. The organic compound according to the present invention has an acid dissociation index (pKa) of 7.0 to 10°5.
pKa) should be between 7.0 and 10.5. 7.
Examples of organic compounds having an acid dissociation index (pKa) of 0 to 10.5 include asparagine, aspartic acid, acetylacetone, adenine, 2-aminoethanol, 2-
Aminoethanethiol, 0-aminophenol, L-alanyl-L-alanine, L-alanylglycine, β-alanylglycine, alanine, β-alanine, β-alaninamide, arginine, isoleucine, inosine, uracil, ethylenediamine, 8-quinolitool, guanine, glycyl-L-alanine, glycine, glycinamide, glutamine, glutamic acid, cresol, chlorophenol, salicylaldehyde, sarcosine, jetanolamine, diethylenetriamine, cystine, cysteine, citrulline, 34-dihydroxyphenylalanine, N N'-dimethylethylenediamine, N, N'-
Dimethylglycine, serine, taurine, tyrosine, triethanolamine, triethylenetetramine, tris(
Hydroxymethyl) methylamine, tryptophan, trimethylamine, 1-naphthol, 2-naphthol, 1
-Nitroso-2-naphthol, m-nitrosophyl, norleucine, valine, histidine, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 4-hydroxyproline, piperazine, hyboxanthin, pyridoxal, pyrogallol, phenylalanine, phenol, p −
Phenolsulfonic acid, fluorophenol, 1,2-
Propanediamine, 13-propanediamine, 0-bromophenol, 1.6-'\xanediamine, benzylamine, benzoylacetone, methionine, 2-mercaptoethanol, mercaptoacetic acid, morpholine, lysine, riboflavin, resorcinol, leucine, etc. It will be done. Further examples of the organic compounds according to the present invention include, for example, "Chemistry Handbook, Basic Edition ■", Chemical Society of Japan, 3rd revised edition, 1982.
Published by Maruzen Co., Ltd., pages n-339 to 342, among which all organic substances having a pKa defined in the present invention can be used. Among these, amino acids such as aspartic acid, β-alanine, glycine, and glutamic acid and their salts are particularly suitable in the present invention. These organic compounds according to the present invention may be added as a mixture of two or more types, or different organic compounds may be used for pre-addition and post-addition. In addition, these organic compounds may be used as a mixture (salt) with an appropriate acid or basic compound,
In order to adjust the pH and promote dissolution, an appropriate acid or basic compound may be used in combination to form an aqueous solution (aqueous dispersion). In particular, when the organic compound-containing solution of the present invention is added later, the pH of the solution is adjusted to 6.0 to 9.5, more preferably 7.0.
It is desirable to adjust the amount to 8.0 and add it. The amount of the organic compound according to the present invention added to the washing liquid is 0.
0.040 to 10% by weight, more preferably 0.10 to 5.0% by weight.
0% by weight is preferred. It is desirable that the washing liquid according to the present invention contains a preservative and/or a bactericidal agent. As preservatives and bactericidal agents, all those that can be used in the rinsing liquid according to the present invention can be used. The amount added to the washing liquid needs to be adjusted depending on the type of compound used (sterilizing power), the type of bacteria mixed in the washing liquid, and its amount, but it is usually in the range of 1 to 30,000 ppm, more preferably 10 to 110,000 ppm. It is best to use within this range. In addition, known additives that do not cause aggregation with organic compounds can be mixed in the washing liquid according to the present invention. Examples include: 1) titanium oxide described in Japanese Patent Publication No. 62-62341;
Metal oxide fine particles such as silicon oxide, and metal oxides whose surfaces are coated with inorganic substances such as alumina, organic substances such as low-molecular polyols, chelating agents, surfactants, etc. to improve dispersibility, etc., 2) Tokkosho Alkali-soluble resins such as phenol formaldehyde resin, cresol formaldehyde resin, xylene resin, and polyhydroxystyrene resin described in JP-A No. 61-45554, 3) JP-A-50-51324, JP-A-51-58101, JP-A-61-261095, No. 62-143055,
Nonionic and anionic surfactants described in Japanese Patent Publication No. 64-8819, etc., 4) Organometallic surfactants described in Japanese Patent Application Publication No. 59-75255, 5) JP-A-60-225798, 61- 18999
6, inorganic and organic phosphoric acid compounds and phosphonic acid compounds described in JP-A No. 61-261095, etc., 6) Liquid surface tension regulators described in JP-A-63-158552, etc., 7) JP-A-Sho 63-158552, etc. Acids or buffers described in JP-A-62-143055, etc. 8) JP-A-62-275782, JP-A-63-19169
No. 3, JP-A No. 1-125292, JP-A No. 1-177541
Natural and synthetic water-soluble polymers described in JP-A No. 62-73270, and chelating agents. These additives may be added to the washing liquid in advance, or may be added afterwards together with the liquid containing the organic compound. The washing section must have a mechanism capable of supplying a washing liquid onto the plate and quickly and completely removing the solubilized photoconductive layer and eluate. The liquid may be directly supplied onto the plate as long as the mechanism can suppress scattering, or the elution promoting member described in JP-A-60-76395 may be applied to the washing mechanism. The protective gum liquid according to the present invention contains a polymer compound, a lipophilic substance, a surfactant, water, and the like. Examples of natural polymers in the polymer compound include starches such as sweet potato starch, horse/yam starch, wheat starch, tapioca starch, and cornstarch, carrageenan, laminaran, seaweed mannan,
Things obtained from algae such as funori, Irish moss, agar, and alginate, grated yam, yam, mannan, quince seed, pectin, tragacanth gum,
Vegetable mucilages such as karaya gum, bovine sunthin gum, guar gum, locust bin gum, tamarind seed gum, gum arabic, carob gum, and benzoin gum; homopolysaccharides such as dextran, glucan, xanthan gum, and levan; and succinoglucan, pullulan, Examples include microbial mucilage such as heterosaccharides such as curdlan and xanthan gum, glue, and proteins such as gelatin, casein, and collagen. In addition to alginate propylene glycol ester, semi-natural products (semi-synthetic products) include viscose, methylcellulose, ethylcellulose, methylethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose, carboxymethyl hydroxyethyl cellulose,
and cellulose derivatives such as hydroxypropyl methylcellulose phthalate, modified gums, and modified starches. Modified gums include carboxymethyl guar gum, hydroxypropyl guar gum, and hydroxyethyl guar gum. Processed starches include white dextrin, yellow dextrin, roasted starch such as pre-deish gum, enzyme-modified dextrin such as enzyme dextrin and Schardinger dextrin, acid-decomposed starch such as solubilized starch, oxidized starch such as dialdehyde starch, and modified starch. Pregelatinized starch such as pregelatinized starch and unmodified pregelatinized starch, phosphate starch,
Esterified starches such as fatty acid starch, sulfate starch, nitrate starch, xanthate starch, and carbamate starch, hydroxyalkyl starch, carboxyalkyl starch, sulfoalkyl starch, cyanoethyl starch, allyl starch, benzyl starch, carbamylethyl starch, and Etherified starch such as dialkylamino starch, methylol crosslinked starch, hydroxyalkyl crosslinked starch, phosphoric acid crosslinked starch, crosslinked starch such as dicarboxylic acid crosslinked starch, starch polyacrylamide copolymer, starch polyacrylonitrile copolymer, cationic Examples include starch graft copolymers such as starch polyacrylic acid ester copolymers, cationic starch vinyl polymer copolymers, starch polystyrene maleic acid copolymers, and starch polyethylene oxide copolymers. Synthetic products include partially acetalized polyvinyl alcohol, allyl-modified polyvinyl alcohol, modified polyvinyl alcohol such as polyvinyl methyl ether, polyvinylethyl ether, polyvinyl isobutyl ether, polyacrylates, partially saponified polyacrylic esters, Polymethacrylates, polyacrylic acid derivatives and polymethacrylic acid derivatives such as polyacrylamide, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, vinylpyrrolidone/vinyl acetate copolymer, carboxyvinyl polymer, styrene/maleic acid copolymer and styrene/crotonic acid copolymer. Among these, those obtained from algae, vegetable mucilages, cellulose derivatives, modified starches, alginate propylene glycol esters, and synthetic products are preferably used because they have good film-forming properties on printing plates. Lipophilic substances include plasticizers, fatty acids, fatty oils, -hydric alcohols, waxes, and lipophilic resins used as vehicles for lithographic printing inks. Preferred lipophilic resins include novolac type phenol resins such as phenol formaldehyde resin and 1-butylphenol formaldehyde resin, xylene resins obtained by condensing phenol and xylene with formaldehyde, resins obtained by condensing phenol and mesitylene with formaldehyde, and polyhydroxy resins. Styrene, brominated polyhydroxystyrene, cashew resin, partially esterified styrene/maleic anhydride copolymer, melamine resin, alkyd resin, polyester resin, epoxy resin, rosin,
Examples include hydrogenated rosin, modified rosin such as rosin ester, petroleum resin such as giltstone, and the like. Preferred plasticizers include, for example, dibutyl phthalate, di-
Phthalic acid diesters such as n-octyl phthalate, di(2-ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, dilauryl phthalate, butylbenzyl phthalate, such as dioctyl azelate, dioctyl adipate, dibutyl sebacate, di(2) - aliphatic dibasic acid esters such as ethylhexyl) sebacate and dioctyl sebacate; epoxidized triglycerides such as epoxidized soybean oil; phosphoric acid esters such as tricresyl phosphate and trischlorethyl phosphate; e.g. benzoic acid; Includes benzoic acid esters such as benzyl. Preferred fatty acids include caproic acid, enanthic acid, caprylic acid, undecylic acid, lauric acid, tridecylic acid,
myristic acid, pentadecyl acid, palmitic acid, heptadecyl acid, stearic acid, nonadecanoic acid, arachidic acid,
Saturated fatty acids such as behenic acid, lignoceric acid, cerotic acid, heptacosanoic acid, montanic acid, tarylic acid, lafcelic acid, isovaleric acid, and acrylic acid, crotonic acid, isocrotonic acid, undecylic acid, oleic acid, elaidic acid,
Cetoleic acid, erucic acid, brassic acid, sorbic acid,
Examples include unsaturated fatty acids such as linoleic acid, linuric acid, arachidonic acid, propiolic acid, stearolic acid, sardine acid, tarylic acid, and lycanic acid. Monohydric alcohols are classified into aliphatic saturated alcohols, aliphatic unsaturated alcohols, aromatic alcohols, alicyclic alcohols, heterocyclic alcohols, and the like. Also,
The -hydric alcohol may have a substituent, and examples of the substituent include halogen atoms such as chloro and brome, alkoxy groups such as methoxy and propoxy, and aryloxy groups such as phenoxy. The protective gum liquid according to the present invention can be manufactured in any manner such as emulsion type, suspension type, non-emulsion type and non-suspension type by appropriately selecting the surfactant and lipophilic substance to be contained. and a suspension type protective gum liquid are suitably used in order to suppress a decrease in the oil sensitivity of the image area of a lithographic printing plate. Further, an emulsion-type protective gum solution is preferable because it strongly suppresses the generation of suspended solids and generates less insoluble matter in the plate-making method of the present invention. The automatic elution machine according to the present invention is preferably one that conveys an electrophotographic printing plate and has an elution section, a water washing section, a rinsing section, a protective gum application section, and a drying section, but other In conventional alkaline development treatment of PS plates, known automatic developing machines and the like can also be used. The electrophotographic lithographic printing plate according to the present invention contains at least an organic photoconductive compound and a binder resin on a conductive support, and is capable of forming a toner image by a conventional electrophotographic development method. The electrically conductive supports used in the invention include plastic sheets with electrically conductive surfaces, paper made impermeable and electrically conductive, or aluminum, zinc, copper-aluminum,
Copper - stainless steel, chromium - bimetal such as copper, chromium -
Examples include conductive supports having a hydrophilic treated surface such as metal plates such as tri-metals such as copper-aluminum, chromium-lead-iron, and chromium-copper-stainless steel. Their thickness is 0
It is preferably 0.07 to 2 mm, more preferably 0.1 to 0.5 mm. Among these supports, aluminum plates are preferably used. This aluminum plate is mainly composed of aluminum and may contain trace amounts of other elements, and conventionally known and publicly used materials can be used as appropriate. Further, it can be used after graining and anodizing using known methods. Prior to graining, degreasing with a surfactant or alkaline aqueous solution is carried out, if desired. Graining treatment methods include mechanical surface roughening methods, electrochemical surface roughening methods, chemical surface selective dissolution methods, and the like. As the mechanical surface roughening method, known methods such as ball polishing, brush polishing, blast polishing, and puff polishing can be used. Further, as an electrochemical surface 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 that combines both methods can also be used, as disclosed in Japanese Patent Laid-Open No. 54-63902. The thus roughened aluminum plate is used after being subjected to alkali etching treatment and neutralization treatment, if necessary. The aluminum plate subjected to the above treatment is anodized. The electrolyte used for anodizing treatment is sulfuric acid, phosphoric acid, oxalic acid, etc., or a mixed acid thereof.
These electrolytes and their concentrations are appropriately determined depending on the type of electrolyte. The conditions for anodizing treatment vary greatly depending on the electrolyte used, so they cannot be specified, but in general, the electrolyte concentration is 1.0 to 80% by weight, and the liquid temperature is 5.0 to 70°C.
, the current density is 5.0-60A/drrr, the voltage is Jo,
It is sufficient that the voltage is 0 to 100V and the electrolysis time is in the range of 10 to 3000 seconds. The amount of anodic oxide film obtained in this way was 0.
10~Log/rrl is good, and even 1゜0~6.0g
A range of /rrf is preferred. Furthermore, as described in Japanese Patent Publication No. 47-5125, it is also preferable to use an anodic oxidation treatment followed by treatment with an aqueous alkali metal silicate solution. In addition, silicate electrodeposition described in US Pat. No. 3,658,662 is also effective. Treatment with polyvinylsulfonic acid as described in DE 1621478 is also suitable. Casein, polyvinyl alcohol, ethyl cellulose, phenol resin, styrene/maleic anhydride copolymer, polyacrylic acid, etc. may be added between the conductive support and the photoconductive layer as necessary to improve adhesion and electrophotographic properties. An alkali-soluble intermediate layer made of acid or the like may be provided. A known electrophotographic photoconductive layer can be provided on the conductive support thus obtained to obtain an electrophotographic photoreceptor. As the photoconductive material used for the photoconductive layer, known organic or inorganic compounds can be used. Examples of inorganic photoconductive materials include cadmium sulfide and zinc oxide. In addition, organic photoconductive materials include a) triazole derivatives described in US Pat. No. 3,112,197, etc., b) oxadiazole derivatives described in US Pat. No. 3,189,447, etc., and C) Japanese Patent Publication No. 1983- Imidazole derivatives described in US Pat. No. 16096, etc., d) US Pat. No. 3,542,544, US Pat.
No. 51-10983, JP-A No. 5193224, No. 5
No. 5-108667, No. 55-156953, No. 56
-boaryarylalkane derivatives described in Publication No. 36636, e) U.S. Pat.
Specification No. 46, JP-A-55-88064, JP-A No. 55-8
No. 8065, No. 49-105537, No. 55-510
86, No. 56-80051, No. 56-88141, No. 57-45545, No. 54-112637, No. 55-74546, etc., f) U.S. Patent No. 3615404 Specification, Special Publication No. 51-
No. 10105, No. 46-3712, No. 47-2833
No. 6, JP-A-54-83435, JP-A No. 54-11083
No. 6, fuconylene diamine derivatives described in No. 54-119925, etc., g) U.S. Pat. No. 3,567,450,
No. 3180703, No. 3240597, No. 3658
No. 520, No. 42321.03, No. 4175961, No. 4012376, West German Patent (DAS) 1110
Specification No. 518, Japanese Patent Publication No. 49-35702, No. 39-
No. 27577, JP-A-55-144250, JP-A No. 56-
Arylamine derivatives described in No. 119132, No. 56-22437, h) U.S. Patent No. 3526501
i) NN described in US Pat. No. 3,542,546, etc.
- Bicalbasil derivatives, j) Oxazole derivatives described in U.S. Pat. The fluorenone derivatives described in m) U.S. Pat.
No. 59143 (corresponding to U.S. Pat. No. 4,150,987),
No. 55-52063, No. 55-52064, No. 55
-46760, 55-85495, 57-11
No. 350, No. 57-148749, No. 57-1041
Hydrazone derivatives described in US Pat. No. 44, etc., n) US Pat. No. 4,047,948, US Pat.
Benzidine derivatives described in JP-A-58-190953 and JP-A-59-95540, etc.
No. 59-97148, No. 59-195658,
stilbene derivatives described in Japanese Patent Publication No. 62-36674, p) polyvinylcarbazole and its derivatives described in Japanese Patent Publication No. 34-10966, q) polyvinyl described in Japanese Patent Publication No. 43-18674 and Japanese Patent Publication No. 43-19192. Vinyl polymers such as pyrene, polyvinylanthracene, poly-2-vinyl-4-(4'-dimethylaminophenyl)-5-phenyloxazole, and poly-3-vinyl-N-ethylcarbazole, r) Japanese Patent Publication No. 19193-1973 S) Polymers such as polyacenaphthylene, polyindene, acenaphthylene/styrene copolymer, etc. described in Japanese Patent Publication No. 56-13940, etc.;
Formaldehyde resin, condensation resin such as ethyl carbazole/formaldehyde resin, t) JP-A-56-9088
Various triphenylmethane polymers described in U.S. Pat. No. 3,397,086, U.S. Pat.
Examples include metal-free or metal (oxide) phthalocyanine and naphthalocyanine, and derivatives thereof, as described in Japanese Patent No. 43, No. 64-2061, and No. 64-4389. The organic photoconductive compounds according to the present invention include a) to U).
The present invention is not limited to the compounds listed above, and conventionally known organic photoconductive compounds can be used. Two or more types of these organic photoconductive compounds can be used in combination, if desired. Furthermore, various pigments, dyes, etc. can be used in combination for the purpose of improving the sensitivity of the photoconductor or imparting sensitivity to a desired wavelength range. Examples of these include: 1) U.S. Pat. No. 4,436,800, U.S. Pat.
No. 41, No. 58-192042, No. 58-21926
No. 3, No. 59-78356, No. 60-179746, No. 61-148453, No. 61-238063,
Monoazo, bisazo, trisazo pigments described in Japanese Patent Publications No. 60-5941, No. 60-45664, etc.; 2) Metal phthalocyanine or metal-free phthalocyanine described in U.S. Pat. No. 3,397,086, No. 4,666,802, etc. Phthalocyanine pigment, 3) U.S. Patent No. 33
4) Indigo and thioindigo derivatives described in British Patent No. 2237680, etc.; 5) Quinacridone pigments described in British Patent No. 2237679, etc.; 6) British Patent No. 2237679, etc.; Patent No. 2237678, JP-A-59-
7) Bisbenzimidazole pigments described in JP-A-47-30331, etc.; 8) U.S. Pat. Nos. 4,396,610 and 4,644,082. Squarium ring-based pigments described in specifications, etc., 9) JP-A-1989-1999
Azurenium salt pigments described in Publications No. 9-53850 and No. 61-212542. In addition, as a sensitization fee, "electronic photography" 129 (1
973), “Organic Synthetic Chemistry” 24 No. 11 10
1.0 (1966) and the like can be used. Examples include: 10) ＾pplied 0ptics Supplem
ent 3 50 (1969), JP-A-50-3954
11) Cyanine dyes described in US Pat. No. 3,597,196, etc.; 12) JP-A-59-164588, 60-16304.
7, No. 60-252517, and the like. These sensitizing dyes may be used alone or in combination of two or more. The photoconductive layer according to the present invention contains compounds such as trinitrofluorenone, chloranil, and tetracyanoethylene in order to improve sensitivity and the like.
No. 2239, No. 58-129439, No. 60-719
Compounds described in Publication No. 65 and the like can be used in combination. The photoconductive layer for an electrophotographic printing plate according to the present invention comprises at least a photoconductive compound and a binder resin. In this electrophotographic photoconductive layer, it is necessary to finally remove the photoconductive layer in the non-image area. Although it cannot be expressed unconditionally because it is determined by the relationship, in the present invention, the monomers constituting the binder resin include at least one type of binder resin containing a monomer having at least a carboxyl group, It is a polymer compound that is soluble or dispersible in the above-mentioned eluent. Specific examples of the binder resin containing a monomer having a carboxyl group according to the present invention include styrene/maleic acid monoalkyl ester copolymer, methacrylic acid/methacrylic acid ester copolymer, and styrene/methacrylic acid/methacrylic acid ester copolymer. acid ester copolymer, acrylic acid/methacrylic acid ester copolymer, styrene/acrylic acid/methacrylic acid ester copolymer, vinyl acetate/crotonic acid copolymer,
Styrene such as vinyl acetate/crotonic acid/methacrylic ester copolymer, methacrylic ester, acrylic ester, vinyl acetate, vinyl benzoate, etc. and acrylic acid,
Methacrylic acid, itaconic acid, crotonic acid, maleic acid,
Copolymers with carboxyl group-containing monomers such as fumaric acid or dibasic acid monoester monomers, as well as methacrylic acid amide, vinyl pyrrolidone, phenolic hydroxyl groups, sulfonic acid groups, sulfonamide groups, and sulfonimide groups. Examples include copolymers with monomers having the following. Among these, particularly preferred monomer-containing copolymers having carboxyl groups include copolymers of styrene and maleic acid monoester, and copolymers of acrylic acid or methacrylic acid and their alkyl esters, aryl esters, or aralkyl esters. A copolymer of two or more elements is preferred. Also good are vinyl acetate and crotonic acid. The binder resin may be used alone or in combination of two or more types as long as it contains at least a carboxyl group-containing monomer as a constituent monomer. When using a mixture of two or more types, a type of binder resin whose constituent monomers do not all contain carboxyl groups and a carboxyl group-containing binder resin may be mixed. Examples of the above-mentioned binder resins that do not contain carboxyl groups include styrene/maleic anhydride copolymers, methacrylic acid amide, vinyl pyrrolidone, monomers having phenolic hydroxyl groups, sulfonic acid groups, sulfonamide groups, and sulfonimide groups. Examples include copolymers of and monomers containing no carbo-xyl groups, phenol resins, partially saponified vinyl acetate resins, xylene resins, vinyl acetal resins such as polyvinyl butyral, and the like. When using a photoconductive compound and a binder resin, if the content of the photoconductive compound is small, the sensitivity will be low. It is preferable to use a mixture of 15 parts by weight or more. In addition, if the photoconductive layer is thin, the charge necessary for toner development cannot be charged, and if it is thick, it not only accelerates the deterioration of the eluate but also induces side etching during elution, making it difficult to obtain a good image. 0.1 to 30 μm, more preferably 0.1 to 30 μm. 5 to 10 μm is good. The electrophotographic lithographic printing plate according to the present invention is obtained by coating a photoconductive layer on a conductive support according to a conventional method. In producing the photoconductive layer, the components constituting the photoconductive layer may be contained in the same layer, or separately contained in two or more layers, for example, a charge carrier generating substance and a charge carrier transporting substance may be contained. Methods of separating and using different layers are known,
It can be created using any method. The coating solution is prepared by dissolving each component constituting the photoconductive layer in an appropriate solvent, but when using components such as pigments that are insoluble in the solvent, a dispersing machine such as a ball mill, paint shaker, Dyno Mill, or Attritor is used. It is used after being dispersed to an average particle size of 0°01 to 5 μm. The binder resin and other additives used in the photoconductive layer can be added during or after dispersing the pigment. The coating solution prepared in this manner is coated onto a support 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 an electrophotographic printing plate. can be obtained. Solvents for the coating solution include halogenated hydrocarbons such as dichloromethane, dichloroethane, and chloroform, alcohols such as methanol, ethanol, 2-propanol, and 1-butanol, ketones such as acetone, 2-butanone, and cyclohexanone, and ethylene. Examples include glycol ethers such as glycol monomethyl ether and 2-methoxyethyl acetate, cyclic ethers such as oxolane, oxane, and dioxane, and esters such as propyl acetate and butyl acetate. In addition to the photoconductive compound and the binder resin, the photoconductive layer may contain plasticizers, surfactants,
Other additives can be added. Examples of the plasticizer include biphenyl, chlorinated biphenyl, 0-terphenyl, p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, and the like. The electrophotographic lithographic printing plate used in the present invention can be produced by a known operation using the above-mentioned electrophotographic photoreceptor. That is, it is charged substantially uniformly in a dark place, and an electrostatic latent image is formed by imagewise exposure. Exposure methods include reflection image exposure using a xenon lamp, tungsten lamp, fluorescent lamp, etc. as a light source, contact exposure through a transparent positive film, and scanning exposure using a laser beam, a light emitting diode, etc. When performing scanning exposure, use He-Ne laser, He-
Cd laser, argon ion laser, krypton ion laser, ruby laser, YAG laser, nitrogen laser, dye laser, excimer laser, GaAs/GaAlAs
, scanning exposure using a laser light source such as a semiconductor laser such as InGaAsP, alexandrite laser, or copper vapor laser, or scanning exposure using a light emitting diode or liquid crystal shutter (line printer using a light emitting diode array, liquid crystal Schani'7 array, etc.) (including a type of light source). Next, the electrostatic latent image is developed with toner. As the development method, either dry development (cascade development, magnetic brush development, powder cloud development) or liquid development can be used. In particular, the liquid development method can form fine toner images and is suitable for producing printing plates with good reproducibility. Further, positive/positive development by normal development or negative/positive development by reversal development under application of an appropriate bias voltage is also possible. The formed toner image can be fixed by a known fixing method, such as heat fixing, pressure fixing, solvent fixing, or the like. A printing plate can be prepared by using the toner image thus formed as a resist and removing the photosensitive layer in the non-image area with an eluent. The toner according to the present invention needs to contain a resin component that has resistivity to the eluent. Examples of resin components include acrylic resins made of methacrylic acid, methacrylic esters, etc., vinyl acetate resins, copolymers of vinyl acetate and ethylene or vinyl chloride, etc.
Vinyl chloride resin, vinylidene chloride resin, vinyl acetal resin such as polyvinyl butyral, polystyrene, copolymers of styrene and butadiene, methacrylic acid esters, etc., polyethylene, polypropylene and their chlorides,
Polyester resins such as polyethylene terephthalate and polyethylene isophthalate, polyamide resins such as polycapramide and polyhexamethylene aziboamide, phenolic resins, xylene resins, alkyd resins, vinyl-modified alkyd resins, gelatin, cellulose ester derivatives such as carboxymethylcellulose, etc. Examples include wax and wax. Further, the toner can also contain a dye or a charge control agent within a range that does not adversely affect development, fixing, etc.

【Example】

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 I J l51050 aluminum sheet at 60°C, 10%
Immersed in NaOH aqueous solution, the amount of aluminum dissolved is 6 g
I etched it so that it read /rrr. After washing with water, it was immersed in a 30% nitric acid aqueous solution for 1 minute to neutralize it, and then thoroughly washed with water. Thereafter, electrolytic surface treatment was performed for 20 seconds in a 0.7% nitric acid aqueous solution, and the surface was washed by immersion in a 20% sulfuric acid aqueous solution at 50° C., followed by water washing. Furthermore, a support for a printing plate was prepared by performing anodization treatment in a 20% aqueous sulfuric acid solution, washing with water, and drying. On the surface-treated surface of this support, the following photoconductive layer composition was dispersed in a paint shaker for 1 hour, applied with a vacuum coater, and dried at 90° for 5 minutes to prepare an electrophotographic lithographic printing plate. At this time, the coating amount of the photoconductive layer was 4.5 g/I. Photoconductive layer coating solution 1 Composition: Butyl methacrylate/methacrylic acid copolymer (40 mol% methacrylic acid) 18 parts by weight Gold-free metal talocyanine 4 parts by weight Butyl acetate
60 parts by weight 2-Proper Tools
18 parts by weight Note) The pKi of methacrylic acid is 4.66
It is. The obtained printing plate precursor was charged with corona discharge in a dark place so that the surface potential (VO) was about +300■, and then
Scanning image exposure using a semiconductor laser (780 nm),
Immediately positively charged toner (manufactured by Mitsubishi Paper Industries, LOM-EDI [
Liquid reversal development was carried out in step I) and the toner was thermally fixed to obtain a toner image on the photoconductive layer. Next, a plate-making process was performed using an automatic eluator, an eluate, a washing solution, and a rinse solution as shown below. 1) A drive device that has an automatic elution machine elution tank, followed by a washing tank, and a rinsing tank, and transports an electrophotographic printing plate that has been subjected to toner development;
The processing liquid in each processing tank is transferred to the storage tank → pump → spray nozzle →
An automatic machine having a device for cycling through the storage tank and a device for replenishing each treatment tank was used. 2) Eluent 1 composition: Sodium silicate aqueous solution (Si 02 min 30% by weight, Si
02 /Na2O molar ratio 2.5) 20 parts by weight Potassium hydroxide 1 part by weight Pure water
79 parts by weight 3) Washing liquid 1 composition Pour 0.1% by weight aqueous solution of sodium dioctyl sulfosuccinate (20+lm3) into a washing tank, and add 40ml of 5% by weight alanine aqueous solution for every 10 A2 size printing plates processed.
was added. 4) Rinse solution 1 composition (20+Im') Citric acid 0.8 parts by weight Phosphoric acid (85% aqueous solution) 0.5 parts by weight Decaglyceryl monolaurate 0.05 parts by weight Sodium hydroxide was added to this to adjust the liquid pH. was adjusted to 5°0, and then adjusted to 100 parts by weight with pure water. Even after continuous printing of 200 plates under the above conditions, no abnormal residue or gel was produced in the rinsing bath, and no malfunctions such as stains in non-image areas were observed in any of the printing plates made. Comparative Example 1 All the same as Example 1 except that a solution (rinsing solution 2) having the same acid composition and adding sodium hydroxide to the solution pH of 3.5 was used instead of rinsing solution 1 of Example 1. When processed under the same conditions, insoluble matter began to float in the rinse liquid 2 after the 40th plate, and at the 50th plate, the insoluble matter adhered to the non-image area of the printing plate, causing printing stains. This insoluble matter is
Even when the temperature of the rinse liquid 2 was increased, or even when it was left to stand for several days, it did not disappear. Example 2 All treatments were carried out under the same conditions as in Example 1, except that a solution (rinsing solution 3) having the following composition was used instead of rinsing solution 1 used in Example 1. Rinse solution 3 composition (20 dm3) Succinic acid 0.5 parts by weight Malic acid 0.4 parts by weight Potassium dihydrogen phosphate 0.5 parts by weight Sorbitan monolaurate 0.05 parts by weight Sodium hydroxide was added to this to form a solution. After adjusting the pH to 4°8, dilute to 100% with pure water.
Parts by weight. Even when 200 plates were continuously passed under the above conditions, as in Example 1, no abnormal residue or gel was produced in the rinsing bath, and satisfactory printed matter was obtained for all the printing plates made. Example 3 The following photoconductive layer composition was coated on the surface-treated surface of the printing plate support prepared in Example 1 under the same conditions as in Example 1 to prepare an electrophotographic printing plate. Photoconductive layer coating solution 2 compositions Vinyl acetate/crotonic acid copolymer (3 mol% crotonic acid) 18 parts by weight Gold-free metal talocyanine 4 parts by weight Butyl acetate
60 parts by weight 2-Proper Tools
18 parts by weight Note) The pKa of crotonic acid is 4.
It is 69. Continuous treatment for 20 minutes was carried out using the same processing solution and plate-making conditions as in Example 1, except that the rinsing liquid 3 used in Example 2 was used as the rinsing liquid.
Even when passing through the 0 plate, as in Example 1, no abnormal residue or gel was produced in the rinsing tank, and satisfactory printed matter was obtained with all the printing plates made. Example 4 The following photoconductive layer composition was coated on the surface-treated surface of the printing plate support prepared in Example 1 under the same conditions as in Example 1 to prepare an electrophotographic lithographic printing plate. Photoconductive layer coating liquid 3 composition styrene/butyl acrylate/acrylic acid copolymer
(Molar ratio 50:15:35) 18 parts by weight Gold-free metal talocyanine 4 parts by weight xylene
60 parts by weight 2-Proper Tools
18 parts by weight Note) The pKa of acrylic acid is 4.
It is 26. Next, a plate-making process was performed using an eluent, a washing solution, and a rinsing solution as shown below. 2) Eluent 2 compositions Monoethanolamine 0.5 parts by weight Triethanolamine 6 parts by weight Benzyl alcohol 1.5 parts by weight EDTA-4F
4 0.4 parts by weight Potassium hydroxide
2 parts by weight pure water
89.6 parts by weight 3) Washing liquid 2 composition Pour 0.15% by weight aqueous solution of polyoxyethylene (6) monooleate (20 dm3) into the washing tank, and add 40% by weight glycine aqueous solution for every 10 A2 size printing plates processed.
m1 was added. 4) Rinse solution 4 composition (20dm3) Citric acid 0.6 parts by weight Adipic acid 0.2 parts by weight Phosphoric acid (
(85% aqueous solution) 0.5 parts by weight Sorbitan monolaurate 0.05 parts by weight Sodium hydroxide was added to this to adjust the pH of the solution to 4.5, and the pH was adjusted to 100 parts by weight with pure water. Even after continuous printing of 200 plates under the above conditions, as in Example 1, there was no abnormal residue or gel in the rinsing tank, and all the printing plates made had no failures such as stains in non-image areas. I couldn't watch it. Example 5 The following photoconductive layer composition was coated on the surface-treated surface of the printing plate support prepared in Example 1 under the same conditions as in Example 1 to prepare an electrophotographic printing plate. Photoconductive layer coating liquid 4 composition styrene/maleic acid monooctyl ester copolymer
(Molar ratio 60:40) -18 parts by weight Gold-free metal talocyanine 4 parts by weight xylene
40 parts by weight oxolane
20 parts by weight 2-Proper Tools
18 parts by weight Note) The pKa of maleic acid is 5.38. Next, a plate-making process was performed using an eluent, a washing solution, and a rinsing solution as shown below. 2) Eluent 3 composition Monoethanolamine triethanolamine benzyl alcohol ED, TA-48 potassium hydroxide pure water 3) Washing solution 31FB 0.15% by weight aqueous solution of sodium dioctyl sulfosuccinate (20 dm3) was charged into the washing tank. Every time 10 A2 size printing plates were processed, an aqueous solution 401 containing 5 parts by weight of alani, 3 parts by weight, and 7 parts by weight was added. 4) Rinse solution 5 composition (20dm") Succinic acid 0.5 parts by weight Citric acid 0.4 parts by weight Potassium dihydrogen phosphate 0.5 parts by weight Sorbitan monolaurate 0.05 parts by weight Add sodium hydroxide to this After adjusting the liquid pt-i to 5°8, dilute it to 1 with pure water.
00 parts by weight. Even when 200 plates were continuously passed under the above conditions, as in Example 1, no abnormal residue or gel was produced in the rinsing tank. Comparative Example 2 All examples are the same except that a solution (rinsing solution 6) having the same acid composition and adding sodium hydroxide to adjust the liquid pH to 4.0 was used instead of rinsing solution 5 used in Example 5. When processed under the same conditions as in 5, insoluble matter began to float in the rinsing liquid after 40 plates, and by the 50th plate at the latest, this insoluble matter adhered to the non-image area of the printing plate, causing printing to occur in that area. Dirt has occurred. Example 6 The following photoconductive layer composition was coated on the surface-treated surface of the printing plate support prepared in Example 1 under the same conditions as in Example 1 to prepare an electrophotographic printing plate. Photoconductive layer coating liquid 5 Composition Benzyl methacrylate/methacrylic acid copolymer (molar ratio 70:30) 18 parts by weight Gold-free metal talocyanine 4 parts by weight Methyl cellosolve acetate 60 parts by weight 2-propanol
18 parts by weight Note) The pKa of methacrylic acid is 4.66. Next, a plate-making process was performed using an eluent, a washing solution, and a rinsing solution as shown below. 2) Eluent 4 composition Potassium silicate 4 parts by weight Ethanol 10 parts by weight Potassium hydroxide 1 part by weight Pure water
85 parts by weight 3) Washing liquid 3 composition Pour 0.15% by weight aqueous solution (20 dm3) of sodium dioctyl sulfosuccinate into the washing tank, and add 40 ml of 5% by weight glycine aqueous solution for every 10 A2 size printing plates processed.
was added. 4) Rinse solution 7 composition (20dm") Citric acid 0.8 parts by weight Ammonium dihydrogen phosphate 0.5 parts by weight Sorbitan monolaurate 0.05 parts by weight Potassium hydroxide was added to this to adjust the pH of the solution to 5. 0, and then adjusted to 100 parts by weight with pure water. Even when printing 200 plates continuously under the above conditions, no abnormal scum or gel was produced in the rinsing tank as in Example 1, and all of the plates made were No malfunctions such as staining of non-image areas occurred in the printing plates. Comparative Example 3 Potassium hydroxide was added with the same acid composition in place of rinsing liquid 7 used in Example 6 to adjust the pH of the liquid. 3°5 solution (
When processing was carried out under the same conditions as in Example 6 except that a rinsing liquid 8) was used, insoluble matter began to float in the rinsing liquid after the 30th plate, and by the 50th plate at the latest, it appeared in the non-image area of the printing plate. This insoluble matter adhered, causing printing stains.

【Effect of the invention】

By the method of the present invention, it has become possible to perform stable treatment for a long period of time without generating insoluble matter in the rinsing solution. Therefore, by using the electrophotographic printing plate obtained according to the present invention, it has become possible to print a large number of sheets without causing inconveniences such as printing stains. Procedural amendment (master) August 23, 1990 1, Case indication 1990 Patent Application No. 98660 2,
Title of the invention: Plate-making method 3 for electrophotographic printing plates; Relationship with the amended case Patent applicant address: 4-2 Marunoshiratama-chome, Chiyoda-ku, Tokyo Contact address: 125 Higashiganemachi-chome, Katsushika-ku, Tokyo 4-1 Mitsubishi Paper Mills Co., Ltd. Patent Department (1) Page 10, line 17 of the specification. "Phosphoric acid and polyphosphoric acid," was corrected to "phosphoric acid, polyphosphoric acid." (2) Ibid., p. 14, line 13. Page 15, line 20. and page 16, line 4.5. Corrected "washing liquid" to "rinsing liquid". (3) Ibid., p. 26, line 19. Corrected "hetero-saccharides, etc." to "hetero-polysaccharides, etc." (4) Ibid., p. 59, line 5. Corrected "0.5 weight" to "0.5 part by weight". (5) Ibid., p. 59, line 6. Corrected "sorbitan monolaurate" to "sorbitan monolaurate". (6) Ibid., p. 60, line 19. "3) 3 compositions of washing liquid" was corrected to "3) 4 compositions of washing liquid".

Claims (1)

[Claims] 1. A toner image is formed on an electrophotographic lithographic printing plate having a photoconductive layer made of at least a photoconductive compound and a binder resin on a conductive support, and then automatically In a plate-making method for an electrophotographic printing plate, in which a non-image area is solubilized by contacting with an alkaline eluent using an eluator, followed by a water washing treatment and a subsequent rinsing treatment, the binder resin is formed. Plate making using a rinsing solution containing at least a monomer having a carboxyl group, and in which the pH of the solution is adjusted to be equal to or higher than the highest value of the acid dissociation constant (pKa) of the monomer having a carboxyl group. Characteristic plate-making method for electrophotographic printing plates. 2. The rinsing liquid contains a polybasic acid, and the pH of the liquid is 7.
The method for making an electrophotographic printing plate according to claim 1, which is as follows. 3. The method for making an electrophotographic printing plate according to claim 2, wherein the polybasic acid has an acid dissociation constant (pKa) of at least 4.5 to 6.0. 4. The method for making an electrophotographic printing plate according to claim 12 or 3, wherein the rinsing liquid further contains at least one preservative and bactericide selected from isothiazolone-based, acid ester-based, and phenol-based preservatives. .