JPH04204667A - Production of electrophotograph planographic printing plate and producing device - Google Patents

Abstract

PURPOSE:To produce a planographic printing plate without the soiling of printing on an edge part by fixing only the required image part of an electrophotograph planographic original plate after toner development is carried out and carrying out the etching of a nonimage part without fixing toner stuck to a side surface part. CONSTITUTION:An electrophotographic printing original plate 3 having toner developed is carried to a fixing process. A toner image on a fixing part 5 on a printing original plate is heated and fixed by infrared rays, but the infrared rays are reflected by a shielding plate 2, so that a printing original plate edge part 4 is carried out without fixing the toner. When, the partially fixed printing original plate is etched, only a toner nonimage part is eluted on the part of the fixing part 5, but the toner image is eluted on the part of the printing original plate edge part 4, as well. Thus, specific stage treating process is not provided, but the printing plate without completely having the soiling of the edge part can be produced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is an electrophotographic method in which a printing plate is produced by forming a toner image on a photoconductive layer and then removing a non-image area other than the toner image area. The present invention relates to a method for producing a lithographic printing plate, particularly an electrophotographic lithographic printing plate that provides a lithographic printing plate in which printing stains are prevented.

(Prior art) Today, as lithographic offset printing plates, there are 25 plates that use positive-working photosensitizers whose main components are diazo compounds and phenolic resins, and negative-working photosensitizers whose main components are acrylic monomers and prepolymers. Although these have been put into practical use, all of them have low sensitivity, so plate making is performed by contact exposure of a film original plate on which an image has been recorded in advance. 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 manipulating manuscripts, corrections, editing, and layout to page composition has become computer-operated, and instant remote control is available through 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 create printing plates directly from plotter output are hardly ever put into practical use, and even in places where electronic editing systems are in operation, output is done using silver halide photographic film, which is then converted into PS plates. The reality is that printing plates are created by contact exposure. This is the light source of the output plotter (e.g. He-Ne laser,
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 semiconductor laser (such as a semiconductor laser).

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-fi9B1, No. 3
No. 8-7758, No. 41-2426, No. 46-394
No. 05, JP-A No. 50-19509, JP-A No. 50-1951
No. 0, No. 52-2437, No. 54-145538,
No. 54-134832, No. 55-IC15254,
Examples include printing original plates for electrophotographic plate making as described in Publications No. 55-153948, No. 55-161250, No. 57-147656, No. 57-1518 [13].

In the above method, it is necessary to remove the non-image area of the electrophotographic photoreceptor by etching to expose the hydrophilic surface. Often used.

When printing using the printing plate obtained in this way,
When printing on paper smaller than the size of the printing plate as in a normal sheet-fed printing press, there is no problem because the printing surface is not the part corresponding to the edge of the printing plate.

However, when printing on a roll of paper using a rotary press such as newspaper printing, printing stains occur at locations corresponding to the edges of the printing plate. This stain is particularly noticeable when toner development is performed by reversal development.

(Problems to be Solved by the Invention) In order to prevent edge staining caused by a lithographic printing plate obtained by reversing development of a lithographic printing original plate for electrophotographic platemaking, the edges (side surfaces) of the lithographic printing original plate for electrophotographic platemaking are coated. A method of preventing toner adhesion by providing an insulating resin layer has been proposed (Japanese Patent Laid-Open No. 178240/1983). However, even with the above-mentioned means, the end stains were not sufficiently eliminated. Therefore, it has been proposed to prevent the edges from becoming dirty by desensitizing the edges of the printing plate.
No. 159404 has proposed this method, but desensitizing liquids are generally conductive in many cases, and toner adhesion occurs during development, particularly during reversal development, and the removal of edge stains is insufficient. Furthermore, Japanese Patent Application Laid-Open No. 1-2616 [i0] proposes to remove toner between a developing section and a fixing section, and it is difficult to completely remove dried toner mechanically. There is a problem in that the removed toner powder contaminates the device, the original printing plate, or the environment.

This invention was made due to the circumstances mentioned above,
The purpose of this invention is to solve the drawbacks of the above-mentioned prior art,
It is an object of the present invention to provide a method and apparatus for producing an electrophotographic lithographic printing plate that reliably prevents printing stains caused by toner adhering to the edge portions during reverse development.

(Means for Solving the Problems) As a result of intensive studies to solve the above problems, the present inventors have found that an electrophotographic lithographic printing original plate having a photoconductive layer formed on a conductive substrate is at least charged. An electrophotographic process includes a charging process, an exposure process, a developing process using toner, a fixing process, and a process for removing the photoconductive layer other than the toner image (hereinafter referred to as an etching process). In a method for manufacturing a lithographic printing plate, the above problem can be solved by fixing toner only in a required portion of the electrophotographic lithographic printing original plate in the developing step.

(Function) In newspaper printing as described above, only the necessary image areas of the electrophotographic lithographic original plate after toner development are fixed, and the edges,
In particular, toner adhering to the side surfaces is removed by etching the non-image areas without fixing the toner, and as mentioned above, it is possible to perform planographic printing without printing stains on the edges without the need for special toner removal means. Able to make plates. In addition to newspaper printing, the present invention is applicable to cases in which a plurality of pages are provided on the same electrophotographic lithographic original plate for plate making (multi-page printing).
By etching a portion of the toner that has adhered to areas other than the necessary image areas without fixing them, a clean lithographic printing plate can be made without any special toner removal means.

As the fixing method of the present invention, conventionally known methods can be used. For example, radiant heat transfer using infrared lamps, xenon flash, etc., convection heat transfer using planar or ribbon heaters, heat transfer via contact with heating rollers or belts, high frequency heating, pressure, solvent vapor, etc. Fixation can be achieved by the following methods or by a combination of these methods.

To fix an arbitrary part as in the present invention, radiation heat transfer, heat conduction by contact, high frequency, and pressure fixing are preferably used, but other methods can also be used. In order to fix only a desired area using these fixing methods, for example, in the case of radiation heat transfer, it is necessary to use a reflector or lens to irradiate heat rays only to the necessary image area, or to fix unnecessary areas. This can be realized by providing a jig that reflects heat rays in a part of the toner. Furthermore, the present invention can be carried out more effectively by cooling only a portion of the toner that is unnecessary, if necessary.

Further, in the case of fixing by a contact method, it is possible to fix only an arbitrary portion by bringing the fixing device into contact with only a necessary image portion.

(Example) FIGS. 1A and 1B are a plan view and a side view showing an example of the method for manufacturing a lithographic printing original plate of the present invention. The electrophotographic printing original plate 3 that has been developed with toner is transported to a fixing step by a transport method (not shown). The fixing process is composed of at least an infrared line heater 1, a reflection plate 6, and a shielding plate 2, and the infrared rays generated by the line heater 1 are turned into parallel rays by the reflection plate 6 and reach the surface of the printing original plate 3. The toner image in the fixing unit 5 on the printing original plate is heated and fixed by this infrared rays, but the printing original plate end portion 4 is transported through the fixing step without the toner fixed thereon because the shielding plate 2 reflects the infrared rays. Next, when this partially fixed printing original plate was etched, only the toner non-image area was eluted in the fixing portion 5, but the toner image was also eluted in the printing original plate edge 4 portion. As a result, it was possible to produce a printing plate with no edge stains at all without providing any special processing steps.

FIGS. 2(A) and 2(B) are a plan view and a side view showing another embodiment of the method for manufacturing a lithographic printing original plate of the present invention.

The fixing process uses at least a flash lamp 8, a reflector 6,
It is composed of a shielding plate 2, and the flash light 9 generated by the flash lamp 8 reaches the surface of the printing original plate 3 so as to be focused by the reflecting plate 6. By conveying the printing original plate while emitting this flash light multiple times, the toner image in the fixing unit 5 on the printing original plate is heated and fixed. Further, the printing original plate end portion 4 is transported through the fixing process without toner being fixed thereon by reflecting the flash light by the shielding plate 2. As a result, printing plates with no edge stains can be produced without any special processing steps.

FIGS. 3(8) and 3(B) are a plan view and a side view showing still another embodiment of the method for manufacturing a lithographic printing original plate of the present invention. The fixing step is performed using a pressure roller 10, which is at least smaller than the original printing plate 3. +1, and the printing original plate 3 is conveyed while fixing the toner in the fixing section 5 by pressure. As a result, it was possible to produce a printing plate with no edge stains at all without providing any special processing steps.

In the embodiment shown in FIGS. 4(8) and 4(B), the fixing process includes at least an infrared line heater 12, a reflecting plate 13, an aluminum foil feeding roller 15, an aluminum foil pressing roller 1B, an aluminum foil winding roller 17, an aluminum foil 18, and the infrared rays generated by the line heater 12 reach the surface of the printing original plate 3 by the reflection plate 13 so as to be focused on the surface. By conveying the printing original plate while irradiating this infrared ray, the toner in the fixing section 5 on the printing original plate,
- The image is heat-fixed. Further, the printing original plate end 4 reflects infrared rays by the aluminum foil 18, and at the same time promotes heat dissipation at the printing original plate end 4, so that the fixing process is carried out without the toner sticking to the original plate end 4. As a result, it was possible to produce a printing plate with no edge stains at all without providing any special processing steps.

FIGS. 5(A) and 5(B) are a plan view and a side view showing still another embodiment of the method for manufacturing a lithographic printing original plate of the present invention. The fixing process includes at least an infrared line heater 12 and a cold air blowing hole 19, and the infrared rays generated by the line heater 12 reach the surface of the printing original plate 3 through a reflection plate 13 so as to be focused.

By conveying the printing original plate while irradiating the infrared rays, the toner image in the fixing section 5 on the printing original plate is heated and fixed.

Further, the printing original plate end portion 4 is cooled by the cold air 20 blown out from the cold air blowing hole 19 and is conveyed through the fixing process without fixing the toner.

As a result, it was possible to produce a printing plate with no edge stains at all without providing any special processing steps.

FIG. 6 shows the fixing state when a printing original plate having a plurality of pages is manufactured using the embodiment shown in FIG. 2 (8).

As a pre-processing step of the main fixing section, a plate feeding section for the photoreceptor, a charging section, a scanning exposure section using a laser, a surface exposure section via a silver halide original, a toner development, etc. are provided. For toner development, conventionally known methods such as cascade development, magnetic brush development, powder cloud development, liquid development, and various other methods can be used. Among these, liquid development is capable of forming fine images and is suitable for creating printing plates. At this time, either normal development or reverse development is possible depending on the combination of the charge polarity of the photoconductor and the charge polarity of the toner. In particular, in the case of reversal development, toner electrically adheres to the edges of the printing original plate, which tends to cause printing stains, so the present invention is particularly effective.

As a post-fixing step, steps such as an etching section, a washing section, a desensitizing section, a drying section, a bender section, etc. can be provided as necessary.

Next, the structure of an electrophotographic printing original plate that can use the apparatus of the present invention will be explained.

Various supports can be used as the conductive substrate of the electrophotographic printing original plate to which the present invention can be applied. For example, plastic sheets with an electrically conductive surface or papers made especially solvent-impermeable and electrically conductive, aluminum plates, zinc plates, or copper-aluminum plates, copper-stainless steel plates,
A conductive substrate with a wood-loving surface such as a bimetallic plate such as a chromium-copper plate, or a trimetallic plate such as a chromium-copper-aluminum plate, a chromium-lead-iron plate, or a chromium-copper-stainless steel plate is used, and its thickness The thickness is preferably in the range of 0.1 to 3 mm, particularly 0.1 to 0.5 mm. Among these substrates, aluminum plates are preferably used. The aluminum plate used in the present invention is a plate-like material 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. It can be used as appropriate.

As the photoconductive material used in the present invention, many conventionally known compounds can be used. For example, triazole 8 conductors, oxadiazole derivatives, imidazole derivatives, polyallylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, allylamine conductors, amino-substituted chalcone conductors,
N,N-bicalbasil conductor, oxazole derivative,
Low molecular weight photoconductive compounds such as styryl anthracene conductors, fluorenone derivatives, hydrazone derivatives, benzidine derivatives, stilbene derivatives, and high molecular weight compounds such as polyvinyl carbazole and its derivatives can also be used.

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 pigments include monoazo,
Bisazo, trisazo pigments, phthalocyanine pigments such as metal phthalocyanine or metal-free phthalocyanine, naphthalocyanine pigments, perylene pigments, indigo, thioindigo derivatives, quinacridone pigments, polycyclic quinone pigments, bisbenzimidazole pigments, squalium salt pigments, These include azulenium salt pigments.

In addition, as a sensitizing agent, [Sensitizer J No. 81987
(Kodansha) p. 125, “Electronic Photography J 12 9 (19
73), “Organic Synthetic Chemistry” En No. 0.111010 (1
966) and the like can be used. Examples include biryllium dyes, triallylmethane dyes, cyanine dyes, and styryl dyes.

The binding resin used in the printing original plate for electrophotographic plate making that can be used in the present invention may be any resin that can elute and remove the non-image area after toner development, and although it is not specified, it can be used as an etching liquid from the viewpoint of pollution and ease of handling. An etching solution mainly composed of an alkaline aqueous solution is preferably used. Therefore, it is preferable that the binding resin be a compound that can be removed with an alkaline aqueous solution. For example, styrene/maleic anhydride copolymer, styrene/maleic anhydride monoalkyl ester copolymer, methacrylic acid/methacrylic acid ester copolymer, styrene/methacrylic acid/methacrylic acid ester copolymer, acrylic acid/methacrylic acid Acrylic esters such as ester copolymers, styrene/acrylic acid/methacrylic ester copolymers, vinyl acetate/crotonic acid copolymers, 9-vinyl acetate/crotonic acid/methacrylic ester copolymers, methacrylic esters, and styrene. , copolymers with acrylic acids such as vinyl acetate, methacrylic acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid and other carboxylic acid-containing substances or acid anhydride group-containing substances, and methacrylates. Copolymers containing acid amides, vinylpyrrolidone, monomers with phenolic hydroxyl groups, sulfonic acid groups, sulfonamide groups, sulfonimide groups, phenolic resins, partially saponified vinyl acetate resins, xylene resins, polyvinyl butyral, etc. Examples include vinyl acetal resin.

The printing plate for electrophotographic platemaking to which the present invention is applied can be obtained by applying a photoconductive layer onto a conductive substrate according to a conventional method. In producing the photoconductive layer, there are known methods such as containing the components constituting the photoconductive layer in the same layer, or separating the charge carrier generating substance and the charge carrier transporting substance into different layers. , it can be created using either method.

In addition to a photoconductive compound and a binding resin, the photoconductive layer of the electrophotographic printing plate to which the present invention can be applied contains a plasticizer, if necessary, to improve the flexibility of the photoconductive layer and the properties of the coated surface. ,
Various additives such as surfactants, management agents, and others can be added. These additives improve the electrostatic properties of the photoconductive layer,
It can be contained within a range that does not deteriorate etching properties.

In the printing original plate for electrophotographic platemaking to which the present invention is applied, if necessary, an intermediate layer may be added for the purpose of improving the adhesion between the conductive substrate and the photoconductive layer, the electrical properties of the photoconductive layer, the etching properties, the printing properties, etc. can be provided.

Examples of the intermediate layer include casein, polyvinyl alcohol, ethylcellulose, polyacrylic acid, monoethanolamine, jetanolamine, triethanolamine, tribronobenolamine, triethanolamine, and their hydrochlorides, oxalates, and phosphoric acids. There are various amino acids such as salts and monoamino monocarboxylic acids such as alanine.

In addition, an overcoat layer that can be removed during nching 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 a mechanically matted layer or a resin layer containing a matting agent.

In addition, the printing original plate used in the present invention includes JP-A-63-17
No. 8240, JP 2-61654, JP 2-6656
By applying a resin layer removable with a processing/quenching liquid to the edge of the rough printing original plate, such as No. 5, the attached toner can be removed more effectively.

Furthermore, Japanese Patent Application No. 1-159404 and Kai-Hyou 1-227398
By desensitizing the edges of the original printing plate by pre-warming as disclosed in Seiji No. 2-128587, it is possible to more effectively prevent the edges from t''r warping during printing.

As the polymer used in the removable resin layer or desensitizing liquid used in the present invention, the following hydrophilic polymer compounds can be effectively used. Specific wood-loving polymers include, for example, natural polymers such as kansho starch, porphyry starch,
Starches such as tapioca starch, wheat starch and corn starch, chala citin, laminaran, seaweed mannan, funori,
Those obtained from algae, such as Irish moss, agar and sodium alginate; vegetable sources, such as yellow mallow, mannan, quince seed, pectin, gum tragacanth, gum karaya, xanthine gum, guarping gum, locust pinkum, gum arabic, carob gum and benzoincum; Mucilages, homopolysaccharides such as dextran, glucan, and levan, heteropolysaccharides such as succinoglucan and santhan gum, mucilages modified using microbial fermentation, glue, proteins such as seratin, cassetin, and collagen, etc. Can be mentioned. In addition to alkynoic acid propylene glycol ester, which is a semi-natural product (semi-synthetic product), viscose, methylcellulose, ethylcellulose, methylethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose, hydroxypropylmethylcellulose phthalate, etc. Examples include fiber conductors and processed starches. Processed starches include roasted starches such as white dextrin, yellow dextrin, and British cam, enzyme-modified dextrins such as enzyme dextrin and Schardinger dextrin, acid-decomposed starches as shown in solubilized starch, oxidized starches as shown in dialdehyde starch, and modified starches. Pregelatinized starch such as 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, sulfur foralkyl starch, cyanoethyl starch, allyl starch,
Etherified starches such as Hensyl starch, carbamylethyl starch and dialkylamino starch, methylol cross-linked starches,
Crosslinked starch such as hydroxyalkyl crosslinked starch, phosphoric acid crosslinked starch and dicarphonic acid crosslinked starch, starch polyacrylamide copolymer, starch polyacrylic acid copolymer, starch polyvinyl acetate copolymer, starch polyacrylonitrile copolymer, cationic starch polyacrylate copolymer,
Examples include starch graft copolymers such as cationic starch vinyl polymer copolymers, 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 alcohol such as polyvinyl methyl ether, polyvinylethyl ether, and polyvinyl isobutyl ether, sodium polyacrylate,
Partially saponified polyacrylic esters, partially saponified polyacrylic ester copolymers, polyacrylic acid derivatives and polymethacrylic acid derivatives such as polymethacrylates and polyacrylamides, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl These include pyrrolidone/vinyl acetate copolymer, carboxyvinyl polymer, styrene/maleic acid copolymer, and styrene/crotonic acid copolymer.

It is preferable that the desensitizing liquid used in the present invention further contains a strong acid potassium salt, which can further enhance the desensitizing effect. 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 using a metal salt of a strong acid, it is recommended to use p) in the range of 11 to 5, preferably 2 to 465.

Also, instead of the metal salt of the strong acid, the general formula +SiO2/n
M2O (M: alkal metal atom, m/n -0,5~1
．． The desensitizing effect can also be enhanced by including the silicate represented by 5) in the desensitizing liquid. As specific silicates, sodium silicate, potassium silicate, lithium silicate, etc. can be used. The silicate used in the present invention is preferably used in an amount of about 0.4% to about 40% by weight, preferably about 0.8% to about 25% by weight, based on the total fat-fading liquid.

When a silicate is used in the desensitizing liquid used in the present invention, it is preferably used within a pH range of 8 to 14, more preferably 9 to 13. Various additives such as a surfactant and a wetting agent may be used in the desensitizing liquid used in the present invention, if necessary.

The desensitizing liquid used in the present invention consists of an aqueous solution of a hydrophilic polymer compound as described above1, for example, U.S. Pat. No. 4,253,999 and U.S. Pat.
It is also possible to use the emulsified desensitizing liquids described in the specifications of No. 4,348,954 and the like. The amount of desensitizing liquid applied to the end surface of the original printing plate is preferably in the range of about 50 to 150 g/m<2>.

The various resins or desensitizing liquids may be applied to the printing original plate by, for example, a brush, a sponge, a roller, etc., or by a well-known method such as spray coating. 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 is to be printed, it is fine to apply the desensitizing liquid to only that end surface, but depending on the usage pattern Assuming that, the coating is preferably applied to two opposing end surfaces, most preferably to the entire outer circumferential end surface (that is, all four side end surfaces).

As the etching solution for removing the photoconductive insulating layer in the toner non-image area after the toner image is formed, any solvent can be used as long as it can remove the photoconductive insulating layer, and the etching solution is not particularly limited. , 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.

Alkaline compounds include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, sodium phosphate, potassium phosphate, ammonia, and monoethanolamine and jetanolamine. , amino alcohols such as triethanolamine, and any organic and inorganic alkaline compounds. As mentioned above, water or many organic solvents can be used as the solvent for the etching solution;
From the viewpoint of pollution, an etching solution mainly containing water is preferably used.

Further, the etching liquid may contain a surfactant, an antifoaming agent, and various other additives as required.

(Effects of the Invention) According to the method and apparatus for manufacturing an electrophotographic lithographic printing plate of the present invention, in the fixing step after toner development, fixation of toner-stained portions at the edges of printing original plates can be prevented by a simple method, thereby achieving the following: Toner stains can be easily removed during the etching process, eliminating the need for mechanical removal means.

[Brief explanation of the drawing]

FIGS. 1(A) and (B) are a plan view and a side view showing one embodiment of the present invention, and FIGS. 2(8) and (B) to 5
Figures (A) and (B) are a plan view and a side view showing another embodiment of the present invention, and Fig. 6 is an example of plate making for multi-sided printing using the present invention. 1... Infrared line heater, 2... Shielding plate, 3...
・Electrophotographic lithographic printing original plate, 4...Printing original plate edge, 5
...Fixing section, 6.Reflector, 7.Infrared rays, 8.
-・Flash lamp, 9...Flash light, 10.
DESCRIPTION OF SYMBOLS 11... Pressure roller, 12... Infrared line heater, 13... Reflector, 14... Infrared rays, 15... Aluminum foil delivery roller, 16... Aluminum foil pressing roller, 17... Aluminum foil winding roller, 18... Aluminum foil, 19... Cold air outlet, 20... Cold air. Applicant's agent Yu Yasugata Migukotsu 20/l-311]

Claims (1)

[Scope of Claims] 1. A charging step of at least charging an electrophotographic lithographic printing original plate having a photoconductive layer layered on a conductive substrate, an exposure step of exposing it to light, and a development step of developing with toner. A method for manufacturing an electrophotographic lithographic printing plate by a step of fixing the toner image, a fixing step of fixing the toner image, and an etching step of removing the photoconductive layer other than the toner image. A method for producing an electrophotographic lithographic printing plate, characterized in that: 2. In the electrophotographic planographic printing plate manufacturing apparatus including at least the charging step, the exposure step, the fixing step, and the etching step, a means for suppressing fixing of the edge of the printing original plate is provided in the fixing section. An apparatus for manufacturing an electrophotographic lithographic printing plate, characterized in that: