JPH07281457A - Positively chargeable laminated planographic printing plate - Google Patents

Abstract

PURPOSE:To provide the printing plate which has high sensitivity to a semiconductor laser, electrophotographic characteristics showing good chargeability, further, excellent properties with respect to image forming and superior plate wear and with which no scumming or tinting is generated. CONSTITUTION:This electrophotographic planographic printing plate has a photoconductive layer contg. a phthalocyanine compound and a binder resin on an electrically conductive substrate and the photoconductive layer is positively charged and then subjected to image exposure to form a toner image and thereafter, the non image area other than the toner image area of the layer is removed with an eluent consisting of an alkaline solvent to form the final printing plate. Further, this layer is a laminated photoconductive layer formed by successively laminating on the substrate a charge transfer layer contg. the binder resin soluble in the eluent and a charge transfer substance and a charge generating layer consisting essentially of the binder resin soluble in the eluent and the phthalocyanine compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a photoconductive layer containing a phthalocyanine compound, and after forming a toner image by electrophotography, removes the photoconductive layer in the non-image area other than the toner image area. The present invention relates to a positively charged layered lithographic printing plate which is used as a printing plate.

[0002]

2. Description of the Related Art Today, as a lithographic printing plate, a positive type photosensitizer containing a quinonediazide compound and a phenol resin as a main component and a PS plate using a negative type photosensitizer containing an acrylic monomer or a prepolymer as a main component are practically used. However, since all of them are low in sensitivity, a film original plate on which an image is recorded in advance is contact-exposed to perform plate making.
On the other hand, due to the progress of computer image processing, storage of large amount of data, and data communication technology, in recent years, computer operations are consistently performed from manuscript input, correction, editing, layout to page setting, and immediate remote communication is achieved by high-speed communication network and satellite communication. An electronic editing system that can output to the terminal plotter of the ground has been put to practical use. In particular, there is a high demand for electronic editing systems in the field of newspaper printing, where immediacy is required. Also, in the field where the original manuscript is currently stored in the form of a film and the printing plate is reproduced as needed based on this,
With the development of large-capacity recording media such as optical discs, it is considered that the originals will be stored as digital data in these recording media. However, direct type printing plates, which directly produce printing plates from the output of end plotters, have hardly been put to practical use, and even when the electronic editing system is in operation, the output is performed on the silver halide photographic film, and this PS plate is used. The actual situation is that a printing plate is produced by exposing the plate to contact. This is the light source of the output plotter (eg He-Ne laser,
One of the causes is that it is difficult to develop a direct type printing plate having a high sensitivity for producing a printing plate in a practical time by using a semiconductor laser or the like.

An electrophotographic photoreceptor is considered as a photoreceptor having high photosensitivity that can provide a direct printing plate. As a method of making a printing plate using electrophotography, a method of eluting the photoconductive layer in the non-image area after forming a toner image is already known. For example, Japanese Examined Patent Publication Nos. 37-17162 and 38-6.
No. 961, No. 38-7758, No. 41-2426,
46-39405, JP-A-50-19509, 50-19510, 52-2437, 54-1.
45538, 54-134632, 55-10.
No. 5254, No. 55-153948, No. 55-161.
No. 250, No. 57-147656, No. 57-1618
An electrophotographic lithographic printing plate described in JP-A No. 63, etc. may be mentioned. In the above method, since it is necessary to remove the non-image portion of the electrophotographic photosensitive member by etching to expose the hydrophilic surface,
A lithographic printing plate is obtained by using a binder resin that dissolves in an alkaline solvent or that swells and desorbs as a binder resin, and by using a toner image as a resist to elute portions other than the toner image portion to expose the hydrophilic surface.

As a conventionally known binding resin used in electrophotographic lithographic printing plates, Japanese Patent Publication No. 41-2426,
37-17162, 38-6961, JP-A-5
No. 2-2437, No. 54-19803, No. 54-13
4632, 55-105254, 50-195.
09, 19510 and the like, styrene-maleic anhydride copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-maleic anhydride copolymer, phenol resin, etc. are known. However, when these are used in an electrophotographic lithographic printing plate using an organic photoconductive compound, there are various problems. When a phenol resin is used as the binder resin, the formed film is fragile and the printing durability is poor, and vinyl acetate-crotonic acid copolymer and vinyl acetate-maleic anhydride copolymer also have insufficient printing durability. there were. When an acrylic ester-based binder is used, the printing durability is good, but the solubility in an alkaline aqueous solution is not sufficient, and there are problems such as a long etching time. Further, in recent years, a direct type printing plate having a high sensitivity for producing a printing plate within a practical time by a light source of an output plotter (eg, He-Ne laser, semiconductor laser, etc.) has been desired. For this, in an electrophotographic lithographic printing plate in which an organic photoconductive compound is dispersed in a binder resin, it is possible to increase the sensitivity by increasing the amount of the organic photoconductive compound, but on the other hand, the charging property is reduced. There was an essential problem.

[0005]

In order to achieve both high sensitivity and chargeability, Japanese Patent Publication No. 4-73577 and Japanese Patent Publication No. 4-73577.
No. 69382 discloses a so-called function-separated electrophotographic laminated photoreceptor applied to a printing plate. However, since the charge generation layer is provided on the aluminum substrate and the charge transport layer is provided on the charge generation layer, high sensitivity and good chargeability are obtained, but after elution, the charge generation substance remains in the grain of the aluminum substrate. There is a problem in that it easily remains and is easily stained during printing. Further, there is a problem that harmful ozone is remarkably generated at the time of corona charging because of the negative charging due to the constitution of the photoreceptor. Although various investigations have been made for these drawbacks, electrophotography having good electrophotographic characteristics that achieve both high sensitivity and chargeability, and having no printing stains and excellent image quality and printing durability. The reality is that there are very few shiki lithographic printing plates. Therefore, an object of the present invention is to have a photoconductive layer containing at least a phthalocyanine-based compound and a binding resin on a conductive support, and after positive charging, after imagewise exposure to form a toner image, other than the toner image portion. In the electrophotographic lithographic printing plate which is used as a printing plate by removing the photoconductive layer of the non-image area with an eluent of an alkaline solvent, it has high sensitivity, good electrostatic properties, and printing durability. The object is to provide a positively chargeable laminated lithographic printing plate having excellent properties and imageability. Another object of the present invention is to provide a positively chargeable laminated lithographic printing plate which has excellent photoconductive layer removal performance and more excellent imageability. Still another object of the present invention is to provide a high-sensitivity positively chargeable laminated lithographic printing plate suitable for image formation by scanning exposure with a laser or the like.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and as a result, have a photoconductive layer containing at least a phthalocyanine compound and a binding resin on a conductive support, and After charging, after image exposure to form a toner image, the photoconductive layer in the non-image area other than the toner image area is removed with an eluent of an alkaline solvent to obtain a printing plate, which is used as an electrophotographic lithographic printing plate, and The conductive layer includes a charge transport layer containing a binder resin soluble in the eluent and a charge transport material, and a charge generation layer containing the binder resin soluble in the eluent and a phthalocyanine compound as main components. The above object can be achieved by using a positive charging type laminated lithographic printing plate which is a laminated type photoconductive layer sequentially provided on the body.

The present invention will be described in detail below. The electrophotographic lithographic printing plate of the present invention can be prepared by forming and fixing a toner image by a conventionally known method and eluting the photoconductive layer in the non-image area. That is, it is positively charged substantially uniformly in a dark place, and an electrostatic latent image is formed by imagewise exposure. Examples of the exposure method include scanning exposure using a semiconductor laser, a He-Ne laser, or the like, reflection image exposure using a xenon lamp, a tungsten lamp, a fluorescent lamp, or the like as a light source, and contact exposure using a transparent positive film. Next, the electrostatic latent image is developed with toner. As a developing method, a conventionally known method such as cascade development, magnetic brush development,
Various methods such as powder cloud development and liquid development can be used. Among them, liquid development is capable of forming a fine image and is suitable for making a printing plate. Further, either a normal development method in which toner is attached to the non-exposed area or a reversal development method in which toner is attached to the exposed area can be used. The reversal development method is suitable for the laser exposure method because it has characteristics that only the image part is exposed and additional writing is possible, fogging is extremely small, and fine line reproducibility is good. The formed toner image can be fixed by a conventionally known fixing method, for example, heat fixing, pressure fixing, solvent fixing or the like. A lithographic printing plate can be prepared by causing the toner image thus formed to act as a resist and eluting the photoconductive layer in the non-image area other than the toner image area with an eluent. As a post-elution step, a washing step, a gumming step, a drying step, a pattern recognizing step equipped with a CCD sensor or the like for pattern recognition, a bender and a punch step for processing a printing plate into a predetermined shape, a plate accumulating step, etc. Can be provided.

Next, the binder resin in the photoconductive layer in the present invention will be described. As the binding resin, any conventionally known binding resin can be used as long as it is a binding resin soluble in the eluate of an alkaline solvent. Among the binder resins, a copolymer mainly composed of an acrylic acid ester or methacrylic acid ester monomer and a vinyl polymerizable monomer having a carboxyl group is preferable. As a result, the performance of removing the photoconductive layer by the eluate becomes better, and the image quality during printing becomes better. Examples of the ester portion of the acrylic acid ester or methacrylic acid ester monomer include an alkyl group or a group having an aromatic ring. Examples of the alkyl group include a linear, branched or saturated carbon ring having 1 to 18 alkyl carbon atoms, which may form a saturated carbon ring, and specific examples thereof include a methyl group, an ethyl group,
n-butyl group, n-pentyl group, t-amyl group, n-hexyl group, i-hexyl group, cyclohexyl group, 2-methylhexyl group, n-octyl group, 2-ethylhexyl group, lauryl group, stearyl group, etc. Is mentioned. Examples of the group in which the ester portion of the (meth) acrylic acid ester has an aromatic ring include a phenyl group, an o-tolyl group,
m-tolyl group, p-tolyl group, p-t-butylphenyl group, chlorophenyl group, benzyl group, o-methylbenzyl group, m-methylbenzyl group, p-methylbenzyl group,
p-ethylbenzyl group, p-propylbenzyl group, 2-
Aromatic such as phenylethyl group, 2- (p-methylphenyl) -ethyl group, 2- (o-methylphenyl) -ethyl group, 3-phenylpropyl group, α-naphthylmethyl group, β-naphthylmethyl group, etc. Those having a hydrocarbon, 2-pyridinomethyl group, 4-pyridinomethyl group, imidazolylmethyl group, 4-indolylmethyl group, pyrimidinomethyl group, thiazolylmethyl group, etc., furan, thiophene, pyrrole, pyran, thiopyran, thiazole, imidazole, pyrimidine, Triazine, indole, quinoline,
Examples thereof include those having an aromatic heterocyclic group such as purine.

The alkyl group or aromatic ring group of the ester portion in the present invention may have a substituent, and in this case, the substituent is a hydrogen atom, an alkyl group, an allyl group, an aryl group or an aralkyl group. , An alkoxy group, an aryloxy group, an alkoxycarbonyl group, a halogen atom, a nitro group, an amide group, a cyano group, a carbonyl group, a carboxyl group, a trifluoromethyl group, an amino group and a dialkylamino group. Preferred substituents include
Hydrogen atom, alkyl group having 1 to 5 carbon atoms, aryl group having 1 to 5 carbon atoms, allyl group having 1 to 10 carbon atoms, aralkyl group having 1 to 10 carbon atoms, alkoxy group having 1 to 5 carbon atoms, carbon number Substituted with an aryloxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 5 carbon atoms, a halogen atom, an amino group, a nitro group, a cyano group, a trifluoromethyl group, a carboxyl group, an amide group, and an alkyl group having 1 to 5 carbon atoms. And an amino group. In the (meth) acrylic acid ester having an alkyl group according to the present invention, a methyl group, an ethyl group, an n-butyl group, an n-pentyl group, and an n-alkyl group having an alkyl carbon number of 1 to 7 are used.
Hexyl group and the like are preferable. In the (meth) acrylic acid ester having an aromatic ring in the present invention, those in which the aromatic ring is an aromatic hydrocarbon are preferable, and those particularly preferable as the (meth) acrylic acid ester having an aromatic ring are substituted or Unsubstituted benzyl acrylate, benzyl methacrylate, phenylethyl acrylate,
Examples include phenylethyl methacrylate, phenyl acrylate, and phenyl methacrylate.

Specific examples of the vinyl polymerizable monomer having a carboxyl group in the present invention include acrylic acid,
Methacrylic acid, crotonic acid, itaconic acid, etc. may be mentioned. In the binder resin of the present invention, the content of at least one monomer selected from acrylic acid ester or methacrylic acid ester monomers and at least one monomer selected from vinyl polymerizable monomers having a carboxyl group is used. The optimum ratio changes depending on the type of monomer and the type of photoconductive layer eluent (etching liquid),
At least one monomer selected from acrylic acid ester or methacrylic acid ester monomers is 10 to 90 mol% of all monomer components, and at least one monomer selected from vinyl polymerizable monomers having a carboxyl group is a single monomer. It is preferably 5 to 80 mol% of the monomer component. In the case of using an alkaline solvent mainly composed of an alkaline aqueous solution as an etching solution from the viewpoint of pollution, it is particularly preferable that the vinyl polymerizable monomer having a carboxyl group is 10 to 70 mol% of all monomer components. preferable.

The binder resin of the present invention may contain a vinyl-polymerizable monomer as a copolymerization component in addition to the monomer selected from the above. Examples of the vinyl-polymerizable monomer include styrene, vinyltoluene, t-butylstyrene, styrene derivatives such as chlorostyrene, substituted or unsubstituted alkylamide of acrylic acid or methacrylic acid, acrylonitrile, vinylidene chloride, and chloride. Examples thereof include vinyl.

(Specific Examples of Binder Resin) Specific examples of the binder resin in the present invention will be given below. Copolymer: (1) benzyl methacrylate-methacrylic acid (90:10) (2) benzyl methacrylate-methacrylic acid (80:20) (3) benzyl methacrylate-methacrylic acid (70:30) (4) benzyl methacrylate-methacrylic acid Acid (60:40) (5) Benzyl methacrylate-methacrylic acid (50:50) (6) Benzyl methacrylate-methacrylic acid (60:40) (7) Benzyl acrylate-acrylic acid (70:30) (8) Benzyl methacrylate -Acrylic acid (60:40) (9) Phenyl acrylate-acrylic acid (60:40) (10) Phenethyl methacrylate-methacrylic acid (65:35) (11) Naphthyl methacrylate-methacrylic acid (60:40) (12) Benzyl methacrylate-meth Methacrylate-methacrylic acid (50:20:30) (13) benzyl methacrylate-n-butyl methacrylate-methacrylic acid (50:10:40) (14) benzyl acrylate-ethyl methacrylate-acrylic acid (50:20:30) )

(15) Phenyl methacrylate-hydroxyethyl methacrylate-acrylic acid (60:10:30) (16) Benzyl methacrylate-methacrylic acid-n-benzyl acrylate (40:40:20) (17) Benzyl methacrylate-methacrylic acid -N-hexyl methacrylate (40:40:20) (18) benzyl methacrylate-methacrylic acid-n-hexyl methacrylate (30:40:30) (19) benzyl methacrylate-methacrylic acid-n-hexyl methacrylate (20:40: 40) (20) benzyl methacrylate-acrylic acid-n-hexyl methacrylate (60:30:10) (21) benzyl methacrylate-acrylic acid-n-hexyl methacrylate (50:30:20) (22) benzyl methacrylate To-acrylic acid-n-hexyl methacrylate (40:30:30) (23) benzyl methacrylate-acrylic acid-n-hexyl methacrylate (30:30:40) (24) benzyl methacrylate-styrene-methacrylic acid (40:10) : 50) (25) 2-pyridinomethylmethacrylate-vinyltoluene-acrylic acid (30:30:40) (26) benzylmethacrylate-ethylmethacrylate-methacrylamide-methacrylic acid (50: 20: 10: 20) (27) ) Benzyl acrylate-ethyl acrylate-itaconic acid (50:20:30) The copolymerization ratio is shown in moles in parentheses. These binding resins use a radical polymerization initiator to perform bulk polymerization, solution polymerization,
It can be easily synthesized by suspension polymerization, and the synthetic method is generally well known. The molecular weight of the binder resin is 1,000 to 50,000.
Although it can be used in the range of 0, the range of 8000 to 150,000 is preferable from the viewpoint of the strength of the formed film and the removal rate of the photoconductive layer.

The charge-transporting substance in the charge-transporting layer used together with the above-mentioned binder resin includes (a) US Pat.
2,197, etc., triazole derivatives, (b) US Pat. No. 3,189,447, etc., oxadiazole derivatives, (c)
Imidazole derivatives described in JP-B-37-16,096, etc., (d) US Pat. No. 3,615,4
02, 3,820,989, 3,542,54
No. 4, Japanese Patent Publication No. 45-555, No. 51-10, 983
No. 51-93,224, 55-108,6.
No. 67, No. 55-156953, No. 56-36, 65.
6, polyarylalkane derivatives described in the specification, gazette and the like, (e) US Pat. Nos. 3,180,729 and 4,
278,746, JP-A-55-88,064, 5
5-88,065, 49-105,537, 5
5-51,086, 56-80,051, 56
-88, 141, 57-45, 545, 54-
Nos. 112,637 and 55-74,546, and pyrazoline derivatives and pyrazolone derivatives described in gazettes, (f) US Pat. No. 3,615,404, Japanese Patent Publication No. 51-10,105, 46-3,712, 47-28,336, JP-A-54-83,435,
No. 54-110,836, No. 54-119,925, phenylenediamine derivatives described in gazettes and the like,

(G) US Pat. No. 3,567,450,
3,180,703, 3,240,597, 3,658,520, 4,232,103, 4,175,961, 4,012,376, West Germany Patent (DAS) 1,110,518, Japanese Patent Publication No.49-
35,702, 39-27,577, JP-A-55.
-144, 250, 56-119, 132, 5
6-22,437, arylamine derivatives described in, for example, (h) US Pat.
No. 501 amino-substituted chalcone derivative, (i)
N, N-bicarbazyl derivatives described in US Pat. No. 3,542,546 and the like, (j) US Pat.
57,203, etc. oxazole derivatives,
(k) Styrylanthracene derivatives described in JP-A-56-46,234 and the like, (l) JP-A-54-11
Fluorenone derivatives described in JP-A-8,837, (m)
U.S. Pat. No. 3,717,462, JP-A-54-5
9,143 (corresponding to US Pat. No. 4,150,987), 55-52,063, 55-52,064.
No. 55, No. 55-46, 760, No. 55-85, 495.
No. 57, No. 57, 350, No. 57-148, 749.
No. 57-104,144, and the hydrazone derivatives described in the gazette, (n) US Pat.
47,948, 4,047,949, 4,26
5,990, 4,273,846, 4,29
9,897, 4,306,008 and other benzidine derivatives, (o) JP-A-58-190,9
53, 59-95,540, 59-97,14
No. 8, No. 59-195,658, No. 62-36, 67.
Stilbene derivatives described in Japanese Patent No. 4, etc.,

(P) Polyvinylcarbazole and its derivatives described in JP-B-34-10,966; (q) Polyvinylpyrene and polyvinylanthracene described in JP-B-43-18,674 and 43-19,192. ,
Poly-2-vinyl-4- (4'-dimethylaminophenyl) -5-phenyloxazole, poly-3-vinyl-
Vinyl polymers such as N-ethylcarbazole, (s) polymers such as polyacenaphthylene, polyindene, copolymers of acenaphthylene and styrene described in JP-B-43-19,193, (t) JP-B-56- Condensed resins such as pyrene-formaldehyde resin, bromopyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin described in JP-A No. 13,940, (u) JP-A-56-
There are various triphenylmethane polymers described in 90,883 and 56-161,550.
In the present invention, the charge transport substance is not limited to the compounds listed in (a) to (u), and all the charge transport substances known so far can be used. It is possible to use two or more types of these charge transport materials in some cases.

As the charge transport material used in the present invention, a hydrazone derivative is preferable in view of compatibility with the binding resin and electrophotographic characteristics. Next, the phthalocyanine compound used in the charge generation layer will be described. As the phthalocyanine compound, various phthalocyanine compounds having different central metals or having a substituent on the benzene ring can be used. For example, Japanese Examined Patent Publication Nos. 44-14, 106 and 45-
8,102, JP-A-58-182,639, JP-A-62-47,054 and the like, metal-free phthalocyanines, JP-A-50-38,543, JP-A-50-95,
852, JP-A-51-108,847, JP-A-51
-109,841 etc. copper phthalocyanine, JP-A-59-49,544, JP-A-59-166,959
JP-A-62-275,272, JP-A-62-6
7,094, JP-A-63-37,163, JP-A-6
Examples thereof include titanyl phthalocyanine described in the publications such as 3-116,158, but not limited to these, various known phthalocyanine compounds can be used. Among these, γ type, δ
Preferred are copper phthalocyanines such as γ-type, ε-type and η-type, metal-free phthalocyanines such as τ-type and χ-type, and titanyl phthalocyanines such as α-type, β-type, m-type and Y-type. The binder resin used for the charge generation layer may be the same copolymer as the binder resin used for the charge transport layer, and the binder resin for the charge generation layer may be the same as or different from the binder resin for the charge transport layer. Good. The solubility of the binding resin of the charge transport layer in the eluate of the alkaline solvent is preferably higher than the solubility of the binding resin of the charge generation layer in terms of elution processing time and print stain countermeasures. A chemical sensitizer may be added to the charge generation layer of the present invention for the purpose of improving sensitivity. For example, electron-withdrawing compounds such as trinitrofluorenone, chloranil, tetracyanoethylene, and the like, JP-A-58-65439 and 58-58.
-102239, 58-129439, 62-
The compound etc. which are described in No. 71965 etc. can be mentioned. The above materials can be used alone or in combination of two or more kinds. Further, the charge transport material used in the charge transport layer may be added.

As the conductive support that can be used in the present invention, various supports can be used. For example, a plastic sheet with a conductive surface or especially a solvent-impermeable and conductive paper, an aluminum plate,
Zinc plate, bimetal plate such as copper-aluminum plate, copper-stainless plate, chrome-copper plate, etc., or hydrophilic property such as chrome-copper-aluminum plate, chrome-lead-iron plate, trimetal plate such as chrome-copper-stainless plate, etc. A conductive substrate having a conductive surface is used, and the thickness thereof is preferably 0.1 to 3 mm, particularly preferably 0.1 to 0.5 mm. Among these substrates, the aluminum plate is preferably used. The aluminum plate used in the present invention is a plate-shaped body such as pure aluminum containing aluminum as a main component or an aluminum alloy containing a small amount of foreign atoms, and its composition is not specified. Can be used. This aluminum plate can be used after graining and anodizing by a conventionally known method. Prior to the graining treatment, a degreasing treatment with a surfactant or an alkaline aqueous solution is carried out, if desired, in order to elute the rolling grease on the surface of the aluminum plate, and the graining treatment is carried out. The graining treatment method includes a method of mechanically roughening the surface, a method of electrochemically melting the surface, and a method of chemically selectively melting the surface. As a method for mechanically roughening the surface, a known method called a ball polishing method, a brush polishing method, a blast polishing method, a buff polishing method or the like can be used. As an electrochemical graining method, there is a method of performing alternating current or direct current in a hydrochloric acid or nitric acid electrolytic solution. Further, as disclosed in Japanese Patent Laid-Open No. 54-63,902, a method in which both are combined can be used.

The roughened aluminum plate is subjected to alkali elution treatment and neutralization treatment, if necessary. The aluminum plate thus treated is anodized. As the electrolyte used for the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used, and the electrolyte and the concentration thereof are appropriately determined depending on the kind of the electrolyte. Since the treatment conditions of anodization vary variously depending on the electrolyte used, it cannot be unconditionally specified, but generally, the concentration of the electrolyte is 1 to 80 wt% solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A. / Dm ² , voltage 1 to 100 V, electrolysis time 1
It is suitable if it is in the range of 0 seconds to 50 minutes. The amount of anodized film is preferably 0.1 to 10 g / m ^2, but more preferably 1 to 6 g / m ² . The thickness of these aluminum plates is preferably 0.1 to 3 mm, particularly 0.1 to 3 mm.
0.5 mm is preferable. Further, an aluminum plate as described in JP-B No. 47-5125, which is anodized and then immersed in an aqueous solution of an alkali metal silicate, is also preferably used. Also, US Pat. No. 36586
The silicate electrodeposition described in No. 62 is also effective. Treatment with polyvinyl sulfonic acid as described in West German Patent No. 16214478 is also suitable.

The electrophotographic lithographic printing plate of the present invention can be obtained by coating a photoconductive layer on a conductive support according to a conventional method. The coating liquid is prepared by dissolving each component constituting the photoconductive layer in a suitable solvent. When using components that are insoluble in solvents such as pigments, use a ball mill, paint shaker,
Particle size of 5 μm with a disperser such as Dynomill or Attritor
It is used dispersedly below. Binding resin used for photoconductive layer,
Other additives can be added during or after dispersion of the pigment. The coating solution thus prepared is coated on a substrate by a known method such as spin coating, blade coating, knife coating, reverse roll coating, dip coating, rod bar coating, spray coating, and dried to obtain an electrophotographic lithographic printing plate. Can be obtained. As a solvent for preparing the coating liquid, dichloromethane, dichloroethane, halogenated hydrocarbons such as chloroform, alcohols such as methanol and ethanol, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethylene glycol monomethyl ether, 2-methoxyethyl acetate. And the like, ethers such as tetrahydrofuran and dioxane, esters such as ethyl acetate and butyl acetate, and the like. In the photoconductive layer of the present invention, in addition to the photoconductive compound and the binder resin, a plasticizer, a surfactant, a matting agent and other various kinds of additives may be added as necessary in order to improve the flexibility of the photoconductive layer and the surface condition of the coating. Additives can be added. These additives can be contained within a range that does not deteriorate the electrostatic characteristics and elution properties of the photoconductive layer.

Regarding the contents of the binder resin and the phthalocyanine-based compound in the charge generation layer of the present invention, the sensitivity decreases when the content of the phthalocyanine-based compound is small. It is preferably used in the range of 02 parts by weight to 2.0 parts by weight, more preferably 0.05 parts by weight to 1.5 parts by weight. Further, if the thickness of the charge generation layer is too thick, elution time is required and the photosensitivity is deteriorated.
The range of 4 μm is preferable. Next, the content of the binder resin and the charge transport material in the charge transport layer of the present invention is 0.05 parts by weight of the charge transport compound per 1 part by weight of the binder resin based on the elution rate, electrophotographic characteristics, film strength and the like. To 1.5 parts by weight, more preferably 0.10 to 1.0 parts by weight. Further, if the thickness of the charge transport layer is too thin, the surface potential required for development cannot be charged,
On the other hand, if the thickness is too thick, side etching is likely to occur, and a good printing plate cannot be obtained.
It is 0.1 to 30 μm, preferably 0.5 to 10 μm.

In the positively-charged laminated lithographic printing plate of the present invention, an intermediate layer may be formed, if necessary, for the purpose of improving the adhesion between the aluminum substrate and the photoconductive layer, the electrical properties of the photoconductive layer, the elution property, the printing properties and the like. Can be provided. Further, if necessary, an overcoat layer that can be eluted during elution of the photoconductive layer can be provided on the photoconductive layer for the purpose of improving the electrical characteristics of the photoconductive layer, image characteristics during toner development, adhesion with toner, and the like. . The overcoat layer may be a mechanically matted layer or a resin layer containing a matting agent. Specifically, various materials described in Japanese Patent Application No. 3-92661 can be used.

In the present invention, the resin component of the toner forming the image portion is not particularly limited as long as it has a resist property with respect to the eluent described below, but the following resins are exemplified. You can For example, acrylic resins using methacrylic acid, acrylic acid and their esters, vinyl acetate resins, copolymer resins of vinyl acetate and ethylene or vinyl chloride, vinyl chloride resins, vinylidene chloride resins, vinyl acetal resins such as polyvinyl butyral. , Polystyrene, copolymer resins of styrene and butadiene and methacrylic acid ester, polyethylene, polypropylene and chlorinated products thereof, polyester resins (for example, polyethylene terephthalate, polyethylene isophthalate, polycarbonate of bisphenol A, etc.), phenol resins, xylene resins, alkyds Examples thereof include resins, vinyl-modified alkyd resins, gelatin, cellulose ester derivatives such as carboxymethyl cellulose, wax, polyolefin and wax. More preferably, from the viewpoint of dispersibility or charge characteristics, methacrylic acid, an acrylic resin using various esters of acrylic acid,
Copolymer resins of methacrylic acid, various esters of acrylic acid and styrene, styrene resins, vinyl acetate resins and the like can be used.

As the eluent for removing the photoconductive layer in the non-image portion of the toner after forming the toner image, any alkaline solvent can be used as long as it can remove the photoconductive layer, and is not particularly limited. The alkaline solvent mentioned here 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.

The alkaline compounds include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, potassium silicate, lithium silicate, sodium metasilicate, potassium metasilicate, sodium phosphate, potassium phosphate, ammonia and mono. Examples thereof include any organic and inorganic alkaline compounds such as ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, triisopropanolamine, diethylaminoethanol, and 2-amino-2-methylpropanol. Among them, especially, the general formula mSiO ₂ / nM ₂ O (M: alkali metal atom, m / n
= 0.5 to 8.5), it is possible to obtain better etching properties and printing characteristics by incorporating the silicate represented by the formula (3) into the etching solution. If necessary, various organic solvents can be added to the etching solution mainly containing water. Preferred organic solvents include methanol, ethanol, propanol, butanol, benzyl alcohol, lower alcohols such as phenethyl alcohol and aromatic alcohols and polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol and polyethylene glycol, ether alcohols,
Amino alcohols, ether esters, ethers, ketones, esters, and other organic solvents or surfactants, antifoaming agents, and various other additives can be contained. Further, as an eluent, JP-A-4-30565
Eluates containing alcohols, amino alcohols, surfactants and water as main components as disclosed in Japanese Patent Application No. 6 and Japanese Patent Application No. 5-896665 can also be used.

[0026]

EXAMPLES The present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Example 1 The surface of a JIS 1050 aluminum sheet was grained with a rotating nylon brush using a pumice-water suspension as an abrasive. The surface roughness (centerline average roughness) at this time is 0.5μ
It was m. After washing with water, it was immersed in a 10% aqueous sodium hydroxide solution at 70 ° C. and eluted so that the amount of aluminum dissolved was 6 g / m ² . After washing with water, it was neutralized by immersing in a 30% nitric acid aqueous solution for 1 minute, and thoroughly washed with water. Then 0.7%
In a nitric acid solution, the voltage at the anode is 13 V and the voltage at the cathode is 6
Using the rectangular wave alternating waveform of the bolt (Japanese Patent Publication No. 55-191
Electrolytic surface roughening was performed for 20 seconds, and the surface was washed by immersing it in a solution of 20% sulfuric acid at 50 ° C. and then with water. Furthermore, a substrate was prepared by anodizing treatment in a 20% aqueous solution of sulfuric acid so that the weight of the anodized film would be 3.0 g / m ² , washing with water, and drying. Next, a coating solution having the following formulation is prepared, coated on the substrate with a bar coater and dried at 120 ° C. for 10 minutes, and a charge transport layer having a dry film thickness of 4.0 μm and a charge generating layer having a dry film thickness of 0.2 μm are formed on a substrate. The layers were sequentially provided on the top to prepare a laminated printing plate. (Coating Liquid for Charge Transport Layer) 1.4-Diphenylaminobenzaldehyde-N, N-diphenylhydrazone ... 32 parts 2. Copolymer of benzyl methacrylate and methacrylic acid: 40 parts (the above copolymer No. 4, methacrylic acid 40 mol%, weight average molecular weight (Mw) = 32,000) 4. Dichloromethane: 133 parts 5.1,2-Dichloroethane: 266 parts

(Coating Liquid for Charge Generation Layer) 1. X type metal-free phthalocyanine: 140 parts Fastogen Blue 8120 (manufactured by Dainippon Ink and Chemicals, Inc.) 2. Copolymer of benzyl methacrylate and methacrylic acid: 140 parts (the above copolymer No. 4, methacrylic acid 40 mol%, Mw = 32,000) 3. N, N'-diethyl, benzylidene thiobarbituric acid: 2.0 parts 4.1-Methoxy-2 propanol: 555 parts 5. Methyl ethyl ketone: 555 parts A mixture having the above composition was uniformly dispersed (dispersion retention time 2 hr) with a high speed dispersion mixer Dynamill (manufactured by BACH0FEN, trade name KDL-5) to obtain a coating liquid for a charge generation layer. did.

The thus-prepared laminated printing plate was corona-charged at +6.8 kV by a static method using an electrostatic copying paper test apparatus EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.), and a semiconductor laser was used for 780 nm. Was used to expose the plate surface to an exposure amount of ² erg / cm ² , and the electrophotographic characteristics were examined. When the surface potential immediately after charging (V0) and the exposure amount (E50) at which the surface potential before exposure is attenuated by light to be halved (E50) were examined as a sensitivity, Vo was + 546V, E
50 was 10.3 erg / cm ^2, and the chargeability was good and the sensitivity was extremely high. Next, the above-mentioned laminated printing plate was charged to a surface potential of +560 V by corona charging, and then a negative image was contact-exposed, toner-developed and fixed. As the toner, 5 g of polybenzyl methacrylate-methyl acrylate particles (particle size 0.2 μm) are dispersed as toner particles in 1000 ml of Isopar H (Esso Standard Co., Ltd.), and 0.01 g of zirconium naphthenate is added as a charge control agent. A clear positive toner image could be obtained by applying a bias voltage of +200 V to the counter electrode and performing reversal development. Next, the non-image area was eluted with the following eluent (1), followed by washing with water and gumming to prepare a printing plate. When printing with a sprint printing machine using this printing plate,
50,000 or more good prints without print stains were obtained.

Eluent (1) -Monoethanolamine 150 g-Benzyl alcohol 20 g-Perex NBL (Kao Sekken Co., Ltd.) 60 g-Feriox 115 20 g-Water 900 g

Examples 2 to 8 Laminated printing plates were prepared by the same procedure except that the charge transporting material and the binder resin of Example 1 were replaced by the charge transporting material and the copolymer having the following structural formulas. Electrophotographic characteristics were measured using EPA-8100 in the same manner as in Example 1. The results are shown in Table-1. All had good chargeability and high sensitivity. The weight average molecular weight of the copolymer used here was 20,000 to 50,000.

[0031]

[Chemical 1]

[0032]

[Chemical 2]

[0033]

[Table 1]

The printing original plate thus prepared was charged to a surface potential of +560 V by corona charging in the same manner as in Example 1, and then a negative image was exposed, toner developed and fixed, and the non-image area was eluted with an eluent. After washing with water and gumming, a printing plate was prepared. When printing was carried out using a sprint printing machine using these printing plates, 50,000 or more good prints free of printing stains were obtained. Example 9 A photosensitive layer of PS plate FNN manufactured by Fuji Photo Film Co., Ltd. was prepared on an aluminum plate eluted with methyl ethyl ketone, and then a coating solution having the following formulation was prepared and coated on the substrate with a bar coater at 120 ° C. for 10 minutes. After drying, a charge transport layer having a dry film thickness of 3.4 μm and a charge generating layer having a dry film thickness of 1.0 μm were sequentially provided on an aluminum plate to prepare a laminated printing plate. When the electrophotographic characteristics were measured using EPA-8100 in the same manner as in Example 1, Vo was +557 V and E50 was 9.7 erg.
/ Cm ² and the chargeability and sensitivity were good.

(Coating Liquid for Charge Transport Layer) 1.4-Diphenylaminobenzaldehyde-N, N-diphenylhydrazone: 24 parts 2. Copolymer of benzyl methacrylate and methacrylic acid: 40 parts (the copolymer No. 5, methacrylic acid 50 mol%, Mw = 35,000) Dichloromethane: 133 parts 5.1,2-Dichloroethane: 266 parts (Coating liquid for charge generation layer) 1. X type metal-free phthalocyanine: 140 parts Fastogen Blue 8120 (manufactured by Dainippon Ink and Chemicals, Inc.) 2. Copolymer of benzyl methacrylate and methacrylic acid: 140 parts (the above copolymer No. 4, methacrylic acid 40 mol%, Mw = 32,000) 3. N, N'-diethyl, benzylidene thiobarbituric acid ... 2.0 parts 4.4-diphenylaminobenzaldehyde-N, N-diphenylhydrazone ... 15 parts 4.1-methoxy-2-propanol ... 555 copies 5. Methyl ethyl ketone: 555 parts The printing original plate thus prepared was charged to a surface potential of +560 V by corona charging in the same manner as in Example 1, and then a negative image was exposed, toner developed and fixed, and a non-image area was removed by an eluent. After elution, it was washed with water and gummed to prepare a printing plate. When printing with a sprint printing machine using this printing plate,
50,000 or more good prints without print stains were obtained.

Example 10 A copolymer (16) (Mw = 40,000) was used in place of the binder resin (5) for the charge transport layer of Example 9, and the binder resin (4) for the charge generation layer was used instead. Polymer (20) (Mw = 36,000)
A laminated printing plate was prepared by exactly the same operation except that was used. When electrophotographic characteristics were measured using EPA-8100 in the same manner as in Example 1, Vo was +555 V and E50 was 1.
The chargeability and sensitivity were 1.4 erg / cm ² and were good. The printing original plate prepared in this manner was charged with a surface potential of +570 V by corona charging, and then a negative image was contact-exposed and exposed.
The toner was developed and fixed. Next, after the non-image area was eluted with the following eluent (2), washing and gumming were carried out in the same manner as in Example 9 to prepare a printing plate. When printing was carried out using a sprint printing machine using this printing plate, 50,000 or more good printed matters free of printing stains were obtained. Eluent (2) -DP-4 (Fuji Photo Film Co., Ltd., positive PS plate eluent) 100 g-Water 800 g-Monoethanolamine 6 g-Benzyl alcohol 8 g-Perex NBL (Kao Sekken Co., Ltd.) 10 g

Comparative Example A single layer printing plate (dry film thickness 4.2 μm) having the following formulation containing a charge transporting substance and a charge generating substance in the same layer was prepared in place of the laminated printing plate of Example 1. Then, the electrophotographic characteristics were measured using EPA-8100 by the same operation as in Example 1. Despite the addition amount of the phthalocyanine compound, which is the charge generating substance, being half the amount of the charge generating layer of Example 1, Vo was +268 V and E50 was 14.7 erg / c.
It is m ² , and it can be seen that the charging property is remarkably reduced. Further, the printing original plate thus prepared was charged to a surface potential of +280 V by corona charging as in Example 1, and then a negative image was exposed, toner developed and fixed, and a non-image area was eluted with an eluent, It was washed with water and gummed, but because the surface potential was too low, the toner adhesion amount decreased and a good printing plate could not be obtained. (Single Layer Photoelectric Layer Coating Solution) 1. X-type metal-free phthalocyanine: 70 parts Fastogen Blue 8120 (manufactured by Dainippon Ink and Chemicals, Inc.) 2.4-Diphenylaminobenzaldehyde-N, N-diphenylhydrazone: 112 parts 3. Copolymer of benzyl methacrylate and methacrylic acid: 140 parts (Copolymer No. 4, methacrylic acid: 40 mol%) 4. N, N'-diethyl, benzylidene thiobarbituric acid: 2.0 parts 5.1-Methoxy-2 propanol: 555 parts 6. Methyl ethyl ketone: 555 parts The mixture having the above composition is uniformly dispersed (dispersion retention time 2 hr) by a high speed dispersion mixer Dynamill (BACH0FEN, trade name KDL-5) to obtain a coating liquid for a photoconductive layer. did.

[0038]

According to the present invention, it is possible to provide a positively chargeable laminated lithographic printing plate having high sensitivity to a semiconductor laser, having excellent electrophotographic characteristics with good charging property, and having excellent imageability and printing durability. You can

Claims (3)

[Claims] 1. A non-image part other than the toner image part, which has a photoconductive layer containing at least a phthalocyanine compound and a binding resin on a conductive support, is positively charged, and is imagewise exposed to form a toner image. In the electrophotographic lithographic printing plate to be a printing plate by removing the photoconductive layer of the part with an eluent of an alkaline solvent, the photoconductive layer contains a binding resin soluble in the eluent and a charge transport substance. A charge transport layer,
A positive charging type laminated lithographic printing plate, which is a laminated type photoconductive layer in which a charge generation layer containing a binding resin soluble in the eluate and a phthalocyanine compound as main components is sequentially provided on the support. . 2. The binding resin soluble in the eluate is a binding resin containing an acrylic acid ester monomer or a methacrylic acid ester monomer and a vinyl polymerizable monomer having a carboxyl group as main components. Positively charged laminated lithographic printing plate. 3. The positively chargeable laminated lithographic printing plate according to claim 1, wherein the image exposure is performed by scanning exposure with laser light, and the toner image formation is performed by a reversal development method.