JPS6017752A - Printing plate for electrophotographic plate making - Google Patents

Abstract

PURPOSE:To make directly a printing plate through the electrophotographic process and to enhance printing resistance by forming a layer composed essentially of a specified azo pigment and an alkali-soluble resin on a conductive substrate. CONSTITUTION:A conductive substrate is coated with a layer composed essentially of an alkali-soluble resin and an azo pigment represented by formula I in which X is formula II or III, and A is a coupler residue. As the coupler of the formula, compds. having a phenolic OH group, such as phenols and naphthols, and aromatic amino compds. are used. As said alkali-soluble resin, a resin solubilizable in an aq. or alcoholic solvent by addition of alkali, and, e.g., a styrene- maleic anhydride copolymer is used, and for this resin, film forming property, electric characteristics, strength of adhesion to a substrate, and especially solubility characteristics, etc. are important. The printing plate of said constitution is good in sensitivity and it can be directly manufactured by using various kinds of light sources, such as laser, and the obtained printing plate has high printing resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a novel printing plate that can be made by electrophotography. More specifically, with a new printing plate containing a specific azo pigment, an electrostatic latent image obtained by charging and subsequent image exposure is developed with toner and fixed to obtain a toner image, and then the non-image area is This invention relates to printing plates that are made by dissolving and removing a photosensitive layer.

BACKGROUND ART Conventionally, as master plates for lithographic printing, those using photosensitive resins or silver halide photosensitive materials have been known.

However, although lithographic printing plates using photosensitive resin have high printing durability, they have low sensitivity, and so-called direct plate making is not possible, and it is necessary to create negatives or positives from the original using silver halide film. For this reason, there are drawbacks such as the need for manpower and limited equipment, and the time required for plate making.

Further, although printing plates using diffusion transfer development or hardening development methods of silver halide photosensitive materials can be directly plate-made, they have the drawbacks of low printing durability and high cost per sheet.

Examples of printing plates for direct plate making using electrophotography include JP-B No. 47-476101 and JP-B No. 48-40.
002, Special Publication No. 48-18325, Special Publication No. 51-157
No. 66, Japanese Patent Publication No. 57-25761 discloses a zinc oxide-resin dispersion printing plate. After forming a toner image on this printing plate by electrophotography, it is treated with an acidic aqueous solution containing, for example, a ferrocyan salt in order to make the non-image area hydrophilic. Printing plates made in this way peel off due to the mechanical pressure applied during printing and the penetration of dampening water into the photosensitive layer and conductive treated surface, and the hydrophilic layer on the surface is destroyed. , its printing durability is 5,000 ~
It was about 10,000 sheets.

In addition, zinc oxide/resin dispersion printing plates are subjected to dye sensitization in order to have sensitivity in the visible light region, but even so, they do not exhibit sensitivity sufficient for practical use in the long wavelength light region of eoonm or more. Therefore, there is a drawback that exposure cannot be performed using a low-output and inexpensive He-Ne laser or semiconductor laser.

JP 3717162, JP 38-7758, JP 46-39405, JP 52-2437, JP 56
．． In the organic photoconductive compound-resin printing plate described in Publication No. 107246, for example, an oxadiazole compound or an Axazole compound is bonded with an alkali-soluble resin such as a styrene-maleic anhydride copolymer. An electrophotographic photoreceptor is used, in which a photographic photosensitive layer is provided on a grained aluminum plate. After an image is formed on this photoreceptor by electrophotography, non-image areas are treated with an alkaline organic solvent. Dissolve and remove it and make a plate.

Similar to zinc oxide-resin printing plates, such organic photoconductive compound-resin printing plates undergo dye sensitization to have sensitivity in the visible light region, but the sensitivity is lower than that of other electrophotographic photoreceptors. Compared to this, it is extremely unsatisfactory. In particular, 60
There is almost no sensitivity to long wavelength light of 0 nm or more,
Image exposure cannot be performed using a He-Ne laser or a semiconductor laser.

Purpose The present inventors have conducted intensive research to solve the problems of the conventionally known printing plates for electrophotographic engraving as described above.
This has led to the completion of the present invention.

An object of the present invention is to provide a printing plate for electrophotographic engraving that has high sensitivity and provides a sharp image with no staining in the image area.

Another object of the present invention is to provide a printing plate for electrophotographic engraving that can be recorded with various light sources such as a He-Ne laser or a semiconductor laser.

In other words, the present invention provides a method for electrophotolithography, characterized in that a layer containing an azo pigment represented by the following general formula and an alkali-soluble resin as main components is disposed on a conductive support. This is the printed version.

General formula (I) Here, as the coupler, (for example, phenols,
Compounds with a phenolic hydroxyl group such as naphthols, aromatic amino compounds with an amino group, aminonaphthols with an amino group and a phenolic hydroxyl group, or an aliphatic or aromatic phenolic ketone group (active methylene group) A compound is used, preferably the coupler residue A has the following general formula (I), (I), (1v), (V
1, Vl>, (■).

'L, A hydrocarbon ring group or a substituent thereof, a heterocyclic group or a substituent thereof, or a styryl group or a substituent thereof, Rs l
It may represent hydrogen, an alkyl group, a phenyl group, or a substituted product thereof, or R2 and R3L may form a ring together with the carbon atom to which they are bonded. ) Co (R4 in formulas (I) and (IV) represents a substituted or unsubstituted hydrocarbon group.) (In the formula, R5 is an alkyl group, carbamoyl group, carboxyl, and Ar+ is a carbocyclic group or their Represents a substitute.

) (wherein, R6 is a hydrocarbon group or a substituted product thereof, Ar
2 represents a hydrocarbon ring group or a substituted product thereof. ) The hydrocarbon ring substituted for X in the general formula used in the present invention includes, for example, a benzene ring, a naphthalene ring, etc.
C is a heterocyclic ring, for example, an indole ring, a carbazole ring, a benzofuran ring, etc., and Y/e is a heterocyclic group such as a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, etc. Examples of the group include pyridyl group, chenyl group, furyl group, indolyl group, benzofuranyl group, carbazolyl group, dibenzofuranyl group, and examples of the ring that R2 and R3 can form together with the carbon atoms to which they are bonded include a fluorene ring. can. Examples of the hydrocarbon group represented by R4 or R6 include alkyl groups such as methyl, ethyl, propyl and butyl groups, aralkyl groups such as benzyl, aryl groups such as phenyl, or substituted products thereof. can be exemplified. Examples of substituents on the hydrocarbon group of R4 or R6 include alkyl groups such as methyl, ethyl, propyl, and butyl; alkoxy groups such as methoxy, ethoxy, propoxy, and butoxy, and chlorine. atom, a halogen atom such as a bromine atom, a hydroxyl group, a nitro group, etc.As a substituent on the phenyl group of R+ or the ring of X, a halogen atom such as a chlorine atom or a bromine atom,
Examples of substituents 1) on the carbocyclic group or heterocyclic group of 2 or the ring formed by R2 and R3 include alkyl groups such as methyl, ethyl, propyl, and butyl groups, methoxy groups, and Alkoxy groups, such as propoxy groups, butoxy groups, halogen atoms, such as chlorine atoms and bromine atoms, dialkyl groups, such as dimethylamino groups and diethylamino groups7! dialkylamino groups such as mino group, dibenzylamino group, and trifluoromethyl group [1
Medyl group, nitro group, cyano group, carboxyl group or its ester, hydroxyl group, sulfonic acid group (-8O3Na>
Examples include. Furthermore, 1 in Ar1 or Ar2
Examples of substituents include phenyl, naphthyl, etc., and examples of substituents include alkyl groups such as methyl, ethyl, propyl, butyl, etc.
Alkoxy groups such as nyl group, me]-oxy group, ethoxy group, propoxy group, butoxy group, halogen atoms such as nitro group, chlorine atom, bromine atom, dialkylamino group such as cyano group, dimethylamino group, diethylamino group, etc. can be exemplified.

The azo pigment used in the present invention is, for example, a.

JP-A-48-70538, b, JP-A-54-1274
It is described in the 2M publication. Examples of these azo gradients are as follows.

The alkali-soluble resin used in the present invention refers to a resin that becomes soluble in an aqueous or alcoholic solvent by adding an alkali. For the purposes of the present invention, in addition to properties such as film-forming properties, electrical properties, and adhesion strength to a support, solubility properties are particularly important for these resins. Examples of resins that exhibit such characteristics include styrene-maleic anhydride copolymers, styrene-methacrylic acid-methacrylate copolymers, methacrylic acid-methacrylate copolymers, and phenol resins. Examples of phenolic resins include phenol, 0-cresol, m-cresol,
p-cresol, ethyl 71nol, isopropylphenol, t-butylphenol, t-amylphenol, hexylphenol, ctylphenol, cyclohexylphenol, 3-methyl-4-chloro-6-[
- at least one divalent phenol such as butylphenol, isopropylcresol, t-butylcresol, t-amylcresol, hexylcresol, t-octylcresol and cyclohexylcresol, formaldehyde, acetaldehyde, acrolein,
A novolac type resin obtained by condensing aldehydes such as crotonaldehyde and furfural under acidic conditions is used.

The printing plate of the present invention may contain an electron-accepting compound or an electron-donating compound, mainly for the purpose of improving electrophotographic properties such as sensitivity.

Examples of electron-accepting compounds include phthalic anhydride, tetrachlorophthalic anhydride, tetrachlorophthalic anhydride,
Pyromellitic anhydride, mellitic anhydride, bigryl chloride,
2.4-dinitrochlorobenzene, 2.4-dinitrobrombenzene, 4-ditropiphenyl, 2,4.6-1
-linitroanisole, 4,6-dichloro-1,3-dinitrobenzene, chloranil, bromoanil, 2,4
．． 7-t-dinitro-9-fluorene, 2,4,5.7
-Titranitro -9-fluorenone, tetracyanoethylene, tetracyanoquinone dimethane, 2,4,5.7
-titranitroki→nonton, 2,4.8-t-linitrothiA xanthone, 2,G,8-trinitro-4day-indeno[1,2-b]]thiAphene-4-Ani, 3
．． 7-1-linitrodibenzodiphen-5,5-dioxide and the like are used.

Examples of electron-donating compounds include 2,5-bis(4
-diethylaminophenyl) -1,3,4-71xasif/zole, 2,5-bis[4-(4-diethylaminostyryl)phenyl] -1,3,4-oxadiazole, 2-(9-ethylcarba Zolyl-3-) -5-
Axadiazole compounds such as (4-diethylaminophenyl)-1,3,4-oxadisol, 2-vinyl-4-(2-chlorophenyl)-5-(4-diethylamino)oxazole, 2-(4-diethylamino)oxazole, -diethylaminophenyl)-4-phenyloxazole, 1-phenyl-3-(4-diethylaminostyryl)-5-(4-diethylaminofuconyl)pyrazoline, 1-phenyl-3-(4-dimethylamino pyrazoline compounds such as styryl)-5-(4-dimethylamino')J-nyl)pyrazoline, 2,2'-dimethyl-4,4-bis(diethylamino)triphenylmethane, benzylaminophenyl)
Propane, diphenylmethane compounds such as tris(4-diethylaminophenyl)methane, fluorene compounds such as 9-(4-dimethylaminobenzylidene)fluorene 1.3-(9-fluorenondene)-9-ethylcarbazole, 9-(4- styryl anthracene compounds such as diethylaminostyryl)anthracene, 9-bromo-10-(4-diethylaminostyryl)anthracene, 1,2-bis(4-diethylaminostyryl)benzene, 1,2-bis(2,4-dimethoxystyryl) Disdyrylbenzene compounds such as benzene, 9-ethylcarbazole-3-aldehyde 1-methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde 1-benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde 1,1 -diphenylhydrazone, 2,4-dimethoxybenzaldehyde 1-benzyl-
1-phenylhydrazone, hydrazone compounds such as 4-diphenylaminobenzal ahydride 1-methyl-1-phenylhydrazone, 4-diphenylaminomethylben,
Stilbene compounds such as 4-dibenzylaminostilbene and 4-ditolylaminemethylben;
Styrylnaphthalene compounds such as nylaminostyryl)naphthalene, 1-(4-dibenzylaminostyryl)naphthalene, 4'-diethylamino-α-phenylstilbene, 4'-methylphenylamino-α-phenylstilbene, etc. -Phenylstilbene compound, 3-
Styrylcarbazole compounds such as styryl-9-ethylcarbazole and 3-(4-diethylamino)styryl-9-ethylcarbazole are used.

The printing plate of the present invention can also contain a plasticizer. Examples of plasticizers include heptatarate esters such as dimethyl tsthalate, diethyl phthalate, and dibutyl phthalate, and glycol esters such as dimethyl glycol phthalate and ethyl phthalyl ethyl glycolate. It can be contained within a range that does not deteriorate properties and alkali solubility.

The conductive substrate used in the present invention is an aluminum plate, a zinc plate, a bimetal plate such as a copper-aluminum plate, a copper-stainless steel plate, a chrome-copper plate, or a chrome-copper plate.
Copper-aluminum plate, chromium-lead-iron plate, chromium-copper-
An S conductive substrate with a hydrophilic surface such as a tri-metal plate such as a stainless steel plate is used, and its thickness is 0.1 to 1 m.
m is preferred.

In addition, especially in the case of a support having an aluminum surface, surface treatments such as graining, dipping in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, etc., or anodizing are performed. Preferably. In addition, as shown in U.S. Pat. No. 2,714,066, an aluminum plate that is grained and then immersed in an aqueous sodium silicate solution, and
It is also preferable to carry out an anodic oxidation treatment and then immersion treatment in an aqueous solution of an alkali metal silicate as shown in Japanese Patent No. 5125.

The above-mentioned anodizing treatment is performed, for example, on the aluminum plate in an electrolytic solution consisting of a solution of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, or boric acid, or a molar acid such as oxalic acid or sulfuric acid, or a salt thereof. This is carried out by passing an electric current through the anode.

In addition, in the present invention, the conductive plate and the light guide plate may be combined with each other. [If necessary, add an alkali-soluble intermediate layer such as casein, polyvinyl alcohol, ethyl cellulose, phenolic resin, styrene-maleic anhydride copolymer, or polyacrylic acid between the substrate and the photoconductor layer or the photoconductive layer. The setting number can be set to 1 to improve electrostatic strength.

The azo pigment used in the printing plate of the present invention may be incorporated into the electrophotographic photosensitive layer together with an alkali-soluble resin and, if necessary, additives such as an electron-accepting compound or an electron-donating compound. is preferably dispersed in the resin, and is usually dispersed in the resin.
By what method is υ incorporated into the photosensitive layer?

In order to produce the electrophotographic printing plate of the present invention, the pigment represented by the above general formula and an alkali-soluble resin are mixed, for example, with tetrahydrofuran, dioxane, dimethylformamide, acetone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl needle, etc. , ff1lIlf butyl, ethyl acetate, toluene, halogenated hydrocarbon, or other organic solvent, and if necessary, an electron-accepting compound or an electron-donating compound is added thereto, followed by dispersion using a ball mill, ultrasonic dispersion machine, etc. A uniformly dispersed coating solution is prepared by a method, and the obtained coating solution is coated onto the conductive support, if necessary, via the above-mentioned intermediate layer, and dried.

The addition port of the azo pigment and alkali-soluble resin forming the electrophotographic photosensitive layer of the printing plate of the present invention is preferably 0.01 to 100 parts by weight and 11 parts by weight of the alkali-soluble resin per 1 part by weight of the azo pigment. If accepting compounds or electron donating compounds are added, they should be added at a concentration of 0.0 to the azo pigment.
1 to 100 mol is preferred, particularly 0.01 to 40 mol. The J7 thickness of the electrophotographic photosensitive layer on the obtained conductive substrate is preferably 1 to 50 μm, particularly 1 to 15 μm.
μm is preferred.

Botto Akira's printing plates for electrophotographic engraving are uniformly charged in bright light using a corona charger, using a light source such as a tungsten lamp, halogen lamp, xenon lamp, or fluorescent lamp, according to the normal electrophotographic method. 1-1
8- Scanning exposure using laser light such as Ne relay, argon laser, or semiconductor laser 1-
An electrostatic latent image is formed, this electrostatic latent image is developed with toner, and fixed by heating to obtain a toner image on the electrophotographic photosensitive layer.

Next, when the printing plate on which the toner image has been formed is immersed in an alkaline eluent, the photosensitive layer in the non-image area that is not masked by the toner image is dissolved and removed, and the hydrophilic surface of the conductive substrate is exposed. Only the exposed toner image portion remains on the surface of the support, and a good printing plate can be obtained.

The eluent used here is, for example, an alkaline aqueous solution of inorganic salts such as sodium silicate, sodium phosphate, sodium hydroxide, and sodium carbonate, an alkaline aqueous solution containing organic amines such as triethanolamine and ethylenediamine, or ethanol, benzyl alcohol, etc. , a solution containing an organic solvent such as ethylene glycol or glycerin or a surfactant is used.

In the printing plate of the present invention, after the toner image is formed, the non-image area is dissolved and removed in the eluent, so the toner components include:
It is preferable that this eluate contains a resin component having resist properties.

This resin component may be anything that is insoluble in the eluate, such as acrylic resin using methacrylic acid, methacrylic acid ester, vinyl acetate resin, copolymer of vinyl acetate and ethylene or vinyl chloride, etc. , vinyl chloride resin, vinylidene chloride resin, vinyl ahytal resin such as polyvinyl butyral, polystyrene, copolymers of styrene and butadiene, methacrylic acid ester, polyethylene, polypropylene and their chlorides,
Examples include polycarbonate, polyester resin, polyamide resin, phenolic resin, xylene resin, alkyd resin, wax, polyolefin, and wax.

The printing plate of the present invention may also contain a quinonediazide compound such as 0-naphthoquinonediazide or a diazo compound for the purpose of increasing the solubility of the electrophotographic photosensitive layer by full-surface exposure after toner image formation.

In the printing plate of the present invention, after the plate-making process is completed, the conductive substrate with a hydrophilic surface is exposed in the non-image area, and the image area covered with oleophilic toner remains. It adheres only to the image area, resulting in good printed matter without background stains.

Further, according to the present invention, there is provided a printing plate 1q that has high printing durability, high sensitivity, and can be directly plate-made using various light sources such as laser light.

Moreover, the photosensitive layer of the printing plate of the present invention is a printed wiring board!
It can also be used for construction.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Azo pigment N0.1 1 mm part Styrene-maleic anhydride copolymer 5 parts by weight Tetrahydrofuran 64 parts by weight A mixture having the above composition was sufficiently pulverized and mixed in a ball mill. The coating was applied onto a grained and anodized aluminum plate using a wire bar and dried at a temperature of 100° C. for 20 minutes to prepare a printing plate having an electrophotographic photosensitive layer having a thickness of 6 μm.

This printing plate was subjected to corona discharge of 10 kV for 10 seconds using an electrostatic copying paper testing device (manufactured by Kawaguchi Electric Seisakusho, Model 5P-428) to make it positively charged, and then tested with tungsten light. was exposed to light at an illuminance of 20 lux.As a result, the charged potential t after 10 seconds was 524 volts, and the half-reduced exposure amount was 14 lux·sec.

Next, this printing plate was charged to about 400 volts by corona discharge in a dark place, and then imagewise exposed using a tungsten light source, and the resulting electrostatic m-image was developed with toner and heat-fixed. Form an image.

Next, the printing plate on which the toner image had been formed was immersed in a 1fiW 1% aqueous sodium silicate solution, and then washed with light brushing with a water jet C to remove the electrophotographic photosensitive layer in the non-image area.

When the printing plate made in this way was printed using a Ricoh+JI17J Fuhit Printing model #IAP-1310 according to the usual method, very clear prints with no background stains were obtained.
I was able to print a million copies.

Example 2 Azo pigment No. 3 1 part-cresol formaldehyde resin 5 parts by weight 2.5-bis(diethylaminophenyl)-1,3,4-71xadiazole 5 parts by weight Tetrahydrofuran 99 parts by weight A mixed solution of the above composition The dispersion obtained by thorough pulverization and mixing using a ball mill was applied onto a grained and anodized aluminum plate with a thickness of 0.25111 m,
It was dried at 100° C. for 20 minutes to produce a printing plate having an electrophotographic photosensitive layer with a thickness of 6 μm.

For this printing plate, the charging potential and half-exposure time were measured in the same manner as in Example 1. As a result, the charging potential was +660 volts, and the half-decay exposure was 7.4 lux·sec.

Next, in the same manner as in Example 1, this printing plate was subjected to charging, imagewise exposure, development, and fixing to form a toner image, and the electrophotographic photosensitive layer in the non-image area was removed.

When printing was carried out in the same manner as in Example 1 using the printing plate made in this manner, 50,000 sheets of very clear printed matter without background smearing were printed.

Example 3 Azo pigment No. 6 1 mm part Methyl methacrylate (80%) / methacrylic 1 (20%) copolymer 5 parts by weight 2.4.7-8921 - 9-Flu A lenone 5 parts by weight Tetrahydrofuran 99 Heavy assembly part The above-mentioned phase mixture was sufficiently pulverized and mixed using a ball mill, and the resulting dispersion was coated on a grained and anodized aluminum plate with a thickness of 0.25 mm.
It was dried at .degree. C. for 20 minutes to produce a printing plate having an electrophotographic photosensitive layer with a thickness of 7 .mu.m.

The charging potential and half-decrease exposure amount of this printing plate were measured in the same manner as in Example 1 except that it was charged at -6, Ok V. As a result, the charging potential was 1,490 volts, and the half-life exposure was m6.3 lux·sec.

Next, this printing plate was charged, image exposed, and exposed in the same manner as in Example 1.
Development and fixation were performed to form a toner image, and the electrophotographic photosensitive layer in the non-image area was removed.

When printing was carried out in the same manner as in Example 1 using the printing plate made in this manner, 50,000 clear prints without background stains were printed.

Example 4 Azo Pigment No. 9 1 part by weight Styrene-maleic anhydride copolymer 5 parts by weight Tetrahydrofuran 64 parts by weight A mixture having the above composition was thoroughly ground and mixed in a ball mill, and the obtained dispersion was prepared to a thickness of about 0.5 mm. 25mm grained,
It was applied on an anodized aluminum plate using a wire bar, dried at 100°C for 20 minutes,
A printing plate having an electrophotographic photosensitive layer with a film thickness of 6 μm was prepared.

This printing plate was positively charged by +6kV corona discharge for 10 seconds using an electrostatic copying paper test M machine (manufactured by @I Kawayokuchi Seisakusho, Model 5P-428), and then tungsten light was applied. was exposed at an illuminance of 20 lux. As a result, 1
The charging potential after 0 seconds is 620 volts, and the half-reduction exposure is 25 lux seconds.

Next, this printing plate is charged to about 400 volts by corona discharge in a bright place, imagewise exposed using a tungsten light source, the electrostatic latent image is developed with toner, and heated and fixed to form a toner image. Formed.

Next, the printing plate on which the 1 henna image was formed was immersed in a 1% by weight aqueous sodium silicate solution, and then washed with a water jet while lightly brushing to remove the electrophotographic photosensitive layer in the non-image area.

When the printing plate thus prepared was printed using a Ricoh A offset printing machine model AP-1310 according to a conventional method, 50,000 sheets of very clear prints without scumming could be printed.

Example 5 Azo pigment No. 11 1 part by weight m-cresol formaldehyde resin 5 parts by weight 2,5-bis<diethylaminophenyl)-1,3,4-J xadiazole 5 parts by weight Tetrahydrofuran 99 parts by weight 11 parts Mixture of the above composition The dispersion obtained by sufficiently pulverizing and mixing using a ball mill was applied onto a grained and anodized aluminum plate with a thickness of 0.25 mm.
It was dried at .degree. C. for 20 minutes to produce a printing plate having an electrophotographic photosensitive layer with a thickness of 6 .mu.m.

With respect to this printing plate, the charging potential and half-decrease exposure amount were measured in the same manner as in Example 4. As a result, the charging potential was -630 volts, and the half-life exposure was 18 lux·sec.

Next, in the same manner as in Example 4, this printing plate was subjected to charging, image exposure, development, and fixing to form a toner image, and the electrophotographic photosensitive layer in non-image areas was removed.

When printing was carried out in the same manner as in Example 4 using this printing plate made by sea urchin, 50,000 sheets of very clear prints with no scuffing could be printed.

Example 6 j'Zo-yori N0.14 1 mff 1 part Methyl methacrylate (80%) / methacrylic acid (20%) copolymer 5 polymers M part 2.4.7-1-linitro-9-fluorenone 5mm
Part 1 Herahydrofuran A 0.25 mm thick aluminum plate was prepared by thoroughly pulverizing and mixing a mixture of 99 hydrofurans in a ball mill, graining the resulting dispersion, and anodizing the mixture. Apply on top, 10
A printing plate having an electrophotographic photosensitive layer having a thickness of 7 μm was prepared by drying at 0° C. for 20 minutes.

The charging potential and half-decrease exposure amount of this printing plate were measured in the same manner as in Example Cow, except that it was charged at -6, Ok V. As a result, the charging potential was 1,630 volts, and the half-reduction exposure was 15 lux·sec.

Next, this printing plate was charged, image exposed, and exposed in the same manner as in Example 4.
Development and fixation were performed to form a toner image, and the electrophotographic photosensitive layer in the non-image area was removed.

Using the printing plate made in this way, printing was carried out in the same manner as for the example cow, and 50,000 clear prints with no background stains were printed.

Effects As explained above, the present invention has good sensitivity, allows direct plate making with various light sources such as laser light, and the resulting printing plate has high printing durability.

Patent applicant Rico Co., Ltd. Agent Patent Attorney Hidetake Komatsu Agent Patent Attorney Hiroshi Asahi

Claims (1)

[Scope of Claims] [11] Printing for electrophotographic printing, characterized in that a layer containing an azo pigment represented by the following general formula (I) and an alkali-soluble resin as main components is provided on a conductive support. Edition. (21) In the azo pigment represented by the general formula (I), A is a general formula (I , heterocycle or a substitute thereof, Y is a hydrocarbon ring group or a substituent thereof, or a substituent thereof, a heterocyclic group or an MWA form thereof, or a styryl group or a substituent thereof, R3 is hydrogen, alkyl or a phenyl group, or a substituent thereof, or R2 and R3 may form a ring together with the carbon atom to which they are bonded.Claim III, Section 1) The printing plate for electronic η true plate making described above. (3) In the azo pigment represented by the general formula (I), A is the general formula (I) or (IV) (formula<N) a3. J:,'Cf (IV) Middle R4c,
Represents a substituted or unsubstituted hydrocarbon group. ) Claim No. 1 (printing plate for electrophotographic engraving according to claim 11. (a)) In the azo pigment represented by the general formula (I),
Claims represented by the general formula (V) rt (wherein, Rs represents an alkyl group, a carbamoyl group, a carboxyl group, or an ester thereof, and Ar+ represents a carbocyclic group or a substituted product thereof) (5) In the azo pigment represented by the general formula (I), A
is the general formula (Vl) or (Vl) II 60 (wherein, R6 is a hydrocarbon group or a substituent thereof, Ar
2 represents a hydrocarbon ring group or an M derivative thereof. ) A printing plate for electrophotolithography according to claim (1).