JPH0527461A - Etching liquid for electrophotographic printing plate - Google Patents

Abstract

PURPOSE:To provide such an etching liquid for electrophotographic printing plate so that, first, the etching speed can be improved while preventing the photoconductive layer from remaining, second, production of precipitation can be prevented, and third, contamination of a roller which causes carrying or squeezing can be prevented, and thereby, no degradation of maintenance property nor contamination of print can be produced. CONSTITUTION:This etching liquid for electrophotographic printing plate is used to remove a photoconductive layer in an area where no picture image is formed after a toner picture image is formed on a planographic printing plate material P by electrophotographic method. This planographic printing material has a photoconductive layer containing an org. photoconductive compd. on a conductive supporting body. This etching liquid contains an alkali agent, org. solvent having <=10wt.% solubility in water at 20 deg.C, aromatic carboxylic acid or aromatic sulfonic acid or salt of these.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an etching solution for electrophotographic printing plates. More specifically, it can improve the etching speed, prevent the photoconductive layer component from remaining, and prevent the occurrence of precipitation.
The present invention relates to an etching solution for electrophotographic printing plates, which can prevent stains during printing.

[0002]

BACKGROUND OF THE INVENTION Conventionally, an electrophotographic printing plate using an organic photoconductive compound has been disclosed in, for example, Japanese Patent Publication Nos. 37-17162 and 3).
8-6961, 41-2426, 46-394
No. 05, JP-A Nos. 50-19509 and 50-1951.
No. 0, No. 54-19803, No. 54-89801,
No. 54-134632, No. 54-145538, No. 55-105254 and the like.

A method for producing such an electrophotographic printing plate (that is, a plate-making method) is one in which a toner image is formed from an electrophotographic printing plate material (original plate) using an organic photoconductive compound by a usual electrophotographic method, and thereafter, a toner image is formed. A general method is to make a plate by treating the non-image area other than the toner image with an etching solution containing an alkaline agent. This method utilizes the difference between the etching property of the toner and the etching property of the photoconductive layer, the toner is not etched at all, and only the photoconductive layer other than the toner-adhered portion is rapidly etched, so that A printed matter with better fine line reproducibility can be obtained.

The toner is not etched, and therefore, it is required that the toner has a resist property during etching.

On the other hand, the photoconductive layer is much more easily etched than the toner, and it is necessary that the photoconductive layer is not excessively etched. On the other hand, after the etching, the toner can be retained to the extent that it can withstand printing a large number of sheets. It must have a strong film forming property.

In order to obtain good fine line reproducibility, the etching treatment liquid is important, but the conventional alkali etching treatment liquid is insufficient.

In view of this, Japanese Patent Application Laid-Open No. 58-2854 proposes an aqueous etching treatment liquid which does not impair the resist property of the toner and has good fine line reproducibility.

[0008]

However, when such a water-based etching treatment liquid is used, there is a problem that the organic photoconductive compound remains in the non-image area, and there is a problem that the etching speed is reduced. Further, the compatibility between the alkaline agent and the organic solvent is low, and when the photoconductive layer component containing the organic photoconductive compound is mixed in the etching solution, there is a problem that precipitation occurs. For this reason, it adheres to the plate and stains on the printing occur.

Further, there is a problem that rollers such as conveyance or squeeze are contaminated, cleaning is required and maintainability is deteriorated, and contaminating of printing occurs.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is, firstly, to provide an etching solution for an electrophotographic printing plate which is capable of improving the etching speed while preventing the photoconductive layer component from remaining.

A second object is to provide an etching solution for electrophotographic printing plates which can prevent the occurrence of precipitation.

A third object is to prevent the roller from being contaminated, such as being conveyed or squeezed, so that maintainability is not deteriorated.
An object of the present invention is to provide an etching solution for electrophotographic printing plates that does not cause stains on printing.

[0013]

The inventor of the present invention has reached the present invention as a result of extensive studies to achieve the above object.

That is, the etching solution for electrophotographic printing plates according to the present invention is a lithographic printing plate material in which a photoconductive layer containing an organic photoconductive compound is provided on a conductive support to form a toner image by an electrophotographic method. Which is an etching solution for removing the photoconductive layer in the non-image area after formation of an alkaline solution, an organic solvent having a solubility in water at 20 ° C of 10% by weight or less, and an aromatic carboxylic acid or a salt thereof. It is characterized by doing.

The present invention will be described below. The alkaline agent used in the present invention includes at least one selected from the following inorganic alkaline agents and organic alkaline agents.

Examples of inorganic alkaline agents: potassium metasilicate, sodium metasilicate, sodium silicate, potassium silicate, sodium hydroxide, lithium hydroxide, sodium triphosphate, dibasic sodium phosphate, potassium triphosphate. , Dibasic potassium phosphate, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, ammonium hydroxide and the like.

Examples of organic alkaline agents: monomethylamine,
Alkylamines such as dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, n-butylamine, mono-, di- or triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, Amino alcohols such as diethylaminoethanol and 2-amino-2-methyl-propanol, ethyleneimine, ethylenediamine, pyridine, and organic silicates.

Alkaline silicates are preferred, and potassium silicate is more preferred. The content of the alkaline agent is preferably in the range of 0.05 to 20% by weight, and when alkali silicate is used, the SiO ₂ concentration is preferably 0.5 to 5.0% by weight, more preferably 0.7 to 2.0% by weight. ..

As the organic solvent having a solubility in water at 20 ° C. of 10% by weight or less used in the present invention, a so-called poorly water-soluble organic solvent is preferably used, and examples thereof include diisobutyl ketone, acetophenone, isophorone and diethyl succinate. , Methyl benzoate, diethyl oxalate, dimethyl phthalate, isobutyl acetate, benzyl benzoate, 2-ethylbutyric acid, ethylene glycol monophenyl ether, ethylene glycol dibutyl ether, ethylene glycol benzyl ether, diethylene glycol di-n-butyl ether, diethylene glycol diacetate , N-amyl alcohol, benzyl alcohol, cyclohexanone, cyclohexanol, N-benzyl ethanolamine, anisyl alcohol, dimethylbenzyl carbitol, 2-N-ethyl Examples thereof include anilinoethanol, propylene glycol-α-monophenyl ether, N-phenylethanolamine, β-anilinoethanol, phenethyl alcohol and the like.

Among these, benzyl alcohol, propylene glycol-α-monophenyl ether and β-anilinoethanol are effective in reducing odor.

The content of these sparingly water-soluble organic solvents in the etching solution is preferably 0.1 to 10%, more preferably 0.3 to 3.0%.

Further, in the present invention, the solubility in water at 20 ° C. is 10 together with the above poorly water-soluble organic solvent.
It is also preferable to use an organic solvent in excess of weight% in combination.

Examples of the organic solvent having a solubility in water at 20 ° C. of more than 10% include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, t-butanol, furfuryl alcohol and tetrahydrofurfuryl alcohol. Alcohols such as: 1,2-propylene oxide, 1,
Ethers or acetals such as 4-dioxane, tetrahydrofuran, methylal: acetone, methylacetone,
Methyl ethyl ketone, acetone oil, acetonylacetone, diacetone alcohol and other ketones: methyl formate, methyl acetate, methyl lactate, ethyl lactate and other esters: ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol , Tripropylene glycol, trimethylene glycol, butanediol,
Polyhydric alcohols such as 1,5-pentanediol, glycerin, trimethylolpropane and 1,2,6-hexanetriol and their derivatives: nitrogen compounds such as monomethylamine, diethanolamine and triethanolamine. Of these, propylene glycol is preferable from the viewpoint of safety and reduction of odor.

These organic solvents are
The range of 0.1 to 10% is preferable, and the range of 0.3 to 10 is more preferable.
It is in the range of 3.0%.

Next, as the aromatic carboxylic acid used in the present invention, benzoic acid or its alkyl group, hydroxyl group,
Examples of the substituent include halogen atoms, amino groups, alkoxy groups, and phenyl groups, such as p-ethylbenzoic acid and pn-
Propylbenzoic acid, pi-propylbenzoic acid, pn-butylbenzoic acid, pt-butylbenzoic acid, 2-hydroxy-4-n-
Alkyl-substituted benzoic acid such as propylbenzoic acid, 2-chloro-4-isopropylbenzoic acid, p-hydroxybenzoic acid,
m-hydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 3,5-dimethoxybenzoic acid, m-sulfobenzoic acid, naphthoic acid, 2-hydroxy-3-naphthoic acid, salicylic acid, Examples include gallic acid. Preferred are benzoic acid, alkyl-substituted benzoic acids such as pt-butylbenzoic acid, naphthoic acid, and 2-hydroxy-3-naphthoic acid.

Further, in the present invention, the salt of the above aromatic carboxylic acid can also be used, and the salt is sodium,
An alkali metal salt such as potassium is preferably used.

The addition amount of these aromatic carboxylic acids or salts thereof is preferably 0.01 to 10%, and more preferably 0.1 to 3.0% with respect to the etching solution.

The etching solution of the present invention may contain a surfactant. It is necessary especially when a small amount of liquid is applied, and it is preferable to add it so that the surface tension is 45 dyne / cm or less. The amount added is preferably 0.0001 to 2.0% by weight, more preferably 0.
It is from 01 to 0.1% by weight. If added excessively, the etching property is impaired. It is not always necessary when a large amount of liquid is supplied by a shower and circulated for use.

Preferred surfactants include anionic surfactants and amphoteric surfactants.

Examples of the anionic surfactant include higher alcohol (C _{8 to} C ₂₂ ) sulfate ester salts, fatty acid alcohol phosphate ester salts, alkylaryl sulfonates, alkylamide sulfonates, and dibasic fatty acid esters. And the like.

Examples of: lauryl alcohol sulphate Na salt, octyl alcohol sulphate Na salt, lauryl alcohol sulphate NH ₄ salt, “Teepol-81” (trade name, manufactured by Ciel Kagaku), di-sodium alkyl sulphate, etc. Examples: cetyl Alcohol phosphate ester Na salt, etc .: Dodecylbenzene sulfonic acid Na salt, isopropyl naphthalene sulfonic acid Na salt, Dinaphthalene disulfonic acid Na salt, metanitrobenzene sulfonic acid Na salt, etc .: C ₁₇ H ₃₃ CON (CH ₃ ) CH ₂ SO ₃ Na, etc .: Sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.

Examples of the amphoteric surfactant include those having an amino group and an acid group in the molecule, as well as those of betaine type, sulfobetaine type and sulfoamino type.

Preferred amphoteric surfactants include N, N
-Dimethyl-N-alkyl-N-carboxymethylammonium betaine, N, N-dialkylaminoalkylenecarboxylic acid salt, N, N, N-trialkyl-N-sulfoalkylene ammonium sulfate ester betaine, 2-
Alkyl-1-carboxymethyl-1-hydroxyethyl imidazolium betaine and the like.

Further, in the present invention, a nonionic surfactant or a cationic surfactant may be used.

As the nonionic surfactant, polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, Polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene behenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene stearyl amine, polyoxyethylene oleyl amine, polyoxyethylene stearic acid amide, Polyoxyethylene oleic acid amide, polyoxyethylene castor oil,
Polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene glyceryl monooleate, polyoxyethylene glycer monostearate, polyoxyethylene propylene glycol monostearate , Oxyethyleneoxypropylene block polymer, distyrenated phenol polyethylene oxide adduct, tribenzylphenol polyethylene oxide adduct, octylphenol polyoxyethylene polyoxypropylene adduct, glycerol monostearate, sorbitan monolaurate, polyoxyethylene sorbitan monolaurate Rate etc. are mentioned.

Examples of these nonionic surfactants include Nikkor manufactured by Nikko Chemicals and Emulgen manufactured by Kao.

Cationic surfactants are roughly classified into amine type and quaternary ammonium salt type, and any of these can be used.

Examples of the amine type include polyoxyethylene alkyl amine, N-alkyl propylene amine, N
-Alkyl polyethylene polyamine, N-alkyl polyethylene polyamine dimethyl sulfate, alkyl biguanide, long chain amine oxide, alkyl imidazoline, 1-
Hydroxyethyl-2-alkyl imidazoline, 1-acetylaminoethyl-2-alkyl imidazoline, 2-
Alkyl-4-methyl-4-hydroxymethyloxazoline and the like.

Examples of the quaternary ammonium salt type are long-chain primary amine salt, alkyltrimethylammonium salt, dialkyldimethylethylammonium salt, alkyldimethylammonium salt, alkyldimethylbenzylammonium salt, alkylpyridinium salt, and alkylquinone. Norinium salt, alkylisoquinolinium salt, alkylpyridinium sulfate, stearamidomethylpyridinium salt, acylaminoethyldiethylamine salt, acylaminoethylmethyldiethylammonium salt, alkylamidopropyldimethylbenzylammonium salt, fatty acid polyethylene polyamide, acylamino Ethylpyridinium salt, Acylcholaminoformylmethylpyridinium salt, Stearooxymethylpyridinium salt, Fatty acid triethanolamine, Fat Acid triethanolamine formate, trioxyethylene fatty acid triethanolamine,
Examples include fatty acid dibutylaminoethanol, cetyloxymethylpyridinium salt, p-isooctylphenoxyethoxyethyldimethylbenzylammonium salt and the like.
("Alkyl" in the above examples of the compound has 6 to 2 carbon atoms.
The straight-chain or partially substituted alkyl of 0 is shown, and specific examples thereof include hexyl, octyl, cetyl, stearyl and the like. ) Further, a cationic surfactant of a polymer having a cation component as a repeating unit, for example, a polymer having a weight average molecular weight of 300 to 50,000 containing a quaternary ammonium salt obtained by copolymerization with a lipophilic monomer is also contained. be able to.

Further, the etching liquid of the present invention may contain a chelating agent for preventing precipitation and contamination. As the chelating agent, a compound that forms a chelate compound by coordinate bond with a metal ion, such as polysulfonic acid,
Polyphosphates, oxy acids and aminopolycarboxylic acids are preferred.

The aminopolycarboxylic acids are represented by the general formula> N- (CH ₂ ) n-COOR (wherein n represents 1 or 2 and R represents a hydrogen atom or an alkali metal). Is a compound having in the molecule, and when the — (CH ₂ ) n—COOR group is represented by X,
It can be classified as follows.

[0042] (1) RNX ₂ type compound (2) NX ₃ type compounds _{(3) RNX-CH 2 -CH} 2 -NX-R type compound _{(4) RNX-CH 2 -CH} 2 -NH 2 Type compound (5) X ₂ NR′-NX ₂ type and a compound containing 4 or more X (wherein R has a substituent such as a hydrogen atom, an alkyl group, a hydroxyalkyl group and an alkoxyalkyl group) Represents an organic group, R'is a chain or cyclic alkylene group,
It represents an organic group such as a phenylene group or a substitution product thereof. )

Examples of typical aminopolycarboxylic acid compounds include iminodiacetic acid, iminodipropionic acid, and N.
-(3,3-dimethylbutyl) iminodiacetic acid, mercaptoethyliminodiacetic acid, methoxyethyliminodiacetic acid,
Methylthioethyliminodiacetic acid, N- (carbamoyl)
Iminodiacetic acid, aminoethyliminodiacetic acid, 2-ethoxycarbonylaminoethyliminodiacetic acid, sulfoethyliminodiacetic acid, nitrilotriacetic acid, carboxyethyliminodiacetic acid, N, N'-ethylenediaminediacetic acid, N-
(2-Hydroxycyclohexyl) ethylenediamine triacetic acid, N'-hydroxyethyl-ethylenediamine-
N, N, N'-triacetic acid, ethylenediaminetetraacetic acid, ethylenediamine-N, N'-diacetic acid-N, N'-
Dipropionic acid, 1,2-propylenediaminetetraacetic acid, trimethylenediaminetetraacetic acid, hexaethylenediaminetetraacetic acid, 1,2-cyclopentanediaminetetraacetic acid, trans-cyclohexane-1,2-diaminetetraacetic acid, 2,2 ′ -Diaminoethyl ether-N, N, N ', N'-tetraacetic acid, diethylenetriaminepentaacetic acid, glycoldiaminetetraacetic acid, thioglycoldiaminetetraacetic acid, 2,2'-diaminoethylthioether-N, N, N', N '-Tetraacetic acid,
N ′, N ″ -domethyltrimethylenetetramine-N,
Examples thereof include N, N ′ ″, N ′ ″-tetraacetic acid, trimethylenetetramine hexaacetic acid, and their sodium salts or potassium salts.

These chelating agents are preferably contained in the range of 0.01 to 2% by weight with respect to the etching solution.
More preferably, it is contained in the range of 0.05 to 0.5% by weight.

In addition to the above, the etching solution of the present invention is, for example, JP-A-51-77401, JP-A-51-80228, and JP-A-53-4.
No. 4202 and 55-52054, the anionic surfactant has a solubility in water of 1 at room temperature.
Additives consisting of 0% by weight or less of an organic solvent, an alkaline agent, water and, if necessary, an antifouling agent can be contained within a range not impairing the object of the present invention.

(Lithographic printing plate material) Next, the lithographic printing plate material to which the etching solution of the present invention is applied is one in which a photoconductive layer containing an organic photoconductive compound is provided on a conductive support. is there. After forming a toner image on the planographic printing plate material by an electrophotographic method, the photoconductive layer in the non-image area is removed using the etching solution of the present invention to obtain a planographic printing plate.

The electrophotographic system is a system in which a toner image is formed on the conductive layer by a process including charging, exposure, development and fixing.

The organic photoconductive composition used in the photoconductive layer preferably contains an organic photoconductive pigment. For example, JP-B-40-2780, 44-12671 and 46-3.
0035, 44-16474, 48-30513, 50-7434
No. 47, No. 47543, No. 47-18544, No. 47-30330,
47-37543, 49-11136, 49-99142, 51-109
841, 54-134632, 55-11715, 55-105254
No. 55, No. 55-153948, No. 55-161250, No. 56-1944,
56-2352, 56-9752, 56-19063, 56-292
No. 50, No. 56-69644, No. 56-50050, No. 59-125751
59-176756, 59-224846, 60-17751, 60
-17752, 60-17753, 60-17754, 60-17755
No. 60, No. 60-17756, No. 60-17757, No. 60-17758, No. 60
-177599, 60-17760, 60-17761, 60-17762
No. 60, No. 60-35750, No. 61-67869, No. 61-67870, No. 62
-64266, 62-198864, 62-217256, 63-97965
No. 63, No. 63-97966, No. 63-226667, No. 63-226668, No. 1-257862, No. 1-260464, No. 1-269944, No. 2-70
No. 58, No. 2-188758, No. 2-188759, No. 2-125265, No.
2-125266, 3-102358 perylene pigments, quinacridone pigments, bisbenzimidazole pigments, aromatic polycondensed ring compounds, monoazo pigments, disazo pigments, trisazo pigments, metal or metal-free phthalocyanine pigments, zinc oxide An organic photoconductive composition containing a photoconductive pigment such as, and optionally a sensitizer, a charge transporting agent and the like is applied.

Of these, phthalocyanine pigments are preferred.

Further, JP-A-58-118658, JP-A-58-150953,
It also works well when etching a two-layer separation type lithographic printing plate as described in JP-A-58-169154, JP-A-58-162960, and JP-A-1-261659.

Further, the present invention suitably acts on the organic photoconductive compounds shown in the following publications in addition to the above-mentioned pigment dispersion type.

JP-A-57-161863, 58-76843, 58-
100862, 58-172649, 58-207049, 59-44060
No. 59-121058, 59-128559, 60-178886,
JP-A 1-222263, 1-161354, 1-163752, 1-
163753, 1-186967, 1-186968, 1-188865
No. 1-216362

The binder used in the photoconductive layer is preferably a polymer compound soluble or dispersible in the etching liquid of the present invention.

Specifically, for example, copolymers of styrene and maleic anhydride, copolymers of styrene and monoalkyl maleic anhydride, methacrylic acid / methacrylic acid ester copolymers, styrene / methacrylic acid / methacrylic acid. Ester copolymers, acrylic acid / methacrylic acid ester copolymers, styrene / acrylic acid / methacrylic acid ester copolymers, vinyl acetate / crotonic acid copolymers, vinyl acetate / crotonic acid / methacrylic acid ester copolymers, etc. Acrylic acid, methacrylic acid, styrene, acrylic acid such as vinyl acetate, methacrylic acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride,
A copolymer or methacrylic acid amide with a carboxylic acid-containing monomer such as fumaric acid or an acid anhydride group-containing monomer,
Copolymers containing monomers having vinylpyrrolidone, phenolic hydroxyl groups, sulfonic acid groups, sulfonamide groups, sulfonimide groups, phenol resins, partially saponified vinyl acetate resins, xylene resins, vinyl acetal resins such as polyvinyl butyral. Can be mentioned.

A copolymer containing a monomer having an acid anhydride group or a carboxylic acid group as a copolymerization component and a phenol resin are preferred because of high charge retention of the photoconductive layer.

The copolymer containing a monomer having an acid anhydride group as a copolymerization component is preferably a copolymer of styrene and maleic anhydride. Further, a half ester of this copolymer can also be used. As a copolymer containing a monomer having a carboxylic acid group as a copolymerization component, there is a binary copolymer of acrylic acid or methacrylic acid and an alkyl ester, an aryl ester or an aralkyl ester of acrylic acid or methacrylic acid. preferable. Further, vinyl acetate and crotonic acid copolymer, and terpolymer of vinyl acetate and vinyl ester of carboxylic acid having 2 to 18 carbon atoms and crotonic acid are also preferable examples. Among the phenolic resins, novolak resins obtained by combining phenol, o-cresol, m-cresol or p-cresol with formaldehyde or acetaldehyde under acidic conditions can be mentioned as particularly preferable ones. Bider alone or 2
You may use it in mixture of 2 or more types.

Examples of the above-mentioned phenol resin include phenol, o-cresol, m-cresol, p-cresol, ethylphenol, isopropylphenol and t-cresol.
Butylphenol, t-amylphenol, hexylphenol, t-octylphenol, cyclohexylphenol, 3-methyl-4-chloro-6-t-butylphenol, isopropylcresol, t-butylcresol, t-amylcresol, hexylresole, t
-A resin obtained by condensing an aliphatic or aromatic aldehyde such as formaldehyde, acetaldehyde, acrolein, crotonaldehyde, furfural, etc. of at least one substituted phenol such as octylcresol and cyclohexylcresol is used as a representative resin. be able to. Also, a polyhydroxyphenyl resin obtained by polycondensation of pyrogallol or resorcinol and acetone can be used.

Among these phenol resins, preferred are phenol, o-cresol, m-cresol and p-.
It is a novolac-type phenol resin obtained by condensing at least one of cresol and formaldehyde or acetaldehyde under acidic conditions.

The average molecular weight of this phenol resin is 350-
It is 20000, preferably about 350 to 6000. These phenolic resins include acetone, methyl ethyl ketone,
Soluble in organic solvents such as methyl isobutyl ketone, ketones such as cyclohexanone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, glycol ethers such as dioxane, esters such as butyl acetate and ethyl acetate What is desirable.

The compounding ratio of the photoconductive compound and the binder is
The binder is preferably 0.01 to 100 parts with respect to 1 part of the photoconductive compound.

As the conductive support, an aluminum plate,
Aluminum laminated with resin, or zinc plate, copper-aluminum plate, copper-stainless plate, chrome-
A conductive support having a hydrophilic surface such as a bimetal plate such as a copper plate or a trimetal plate such as a chrome-copper-aluminum plate, a chrome-lead-iron plate and a chrome-copper-stainless plate is used.

Further, particularly in the case of a support having an aluminum surface, surface treatment such as graining treatment, anodic oxidation treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like is carried out. Preferably.

Further, as described in US Pat. No. 2,714,066, an aluminum plate which has been grained and then immersed in an aqueous solution of sodium silicate, and Japanese Patent Publication No. 47-5125.
As described in Japanese Patent Laid-Open Publication No. 2003-242242, an aluminum plate subjected to anodizing treatment and then immersed in an aqueous solution of an alkali metal silicate is also preferably used.

The anodizing treatment is carried out by using an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid or nitric acid, an organic acid such as oxalic acid or sulfamic acid, or an aqueous solution or a non-aqueous solution of these salts, or a combination of two or more thereof. It is carried out by passing an electric current in an electrolytic solution using an aluminum plate as an anode.

Further, silicate electrodeposition as described in US Pat. No. 3658662 is also effective. The treatment with polyvinylphosphonic acid described in West German Patent Publication No. 16214278 is also suitable.

These hydrophilic treatments are carried out for the purpose of preventing harmful reaction with the photoconductive layer provided thereon, and for the purpose of making the surface of the support hydrophilic, except that the hydrophilic treatment is carried out. It is applied to improve the adhesion.

In the present invention, if necessary, an alkali-soluble substance such as casein, polyvinyl alcohol, ethyl cellulose, phenol resin, styrene-maleic anhydride copolymer, polyacrylic acid, etc. is provided between the conductive support and the photoconductive layer. Can be provided for the purpose of improving the adhesiveness between the support and the photoconductive layer.

(Method for producing planographic printing plate material) The photoconductive compound and the binder are mixed in an amount of 0.01 to 100 parts of the binder with respect to 1 part of the photoconductive compound, and the mixture is mixed in an organic solvent. Disperse evenly with an ultrasonic disperser.

The obtained photoconductive composition (photosensitive solution) is coated on a conductive support to a thickness of 1 to 50 μm, preferably 1 to 10 μm and dried to enhance the solubility of the photoconductive layer in an etching solution. Therefore, it is obtained by heat treatment at 70 ° C. or higher.

(Method for producing electrophotographic lithographic printing plate) When a lithographic printing plate material prepared by coating a photoconductive layer on a conductive support and drying is used to form a printing plate by an ordinary electrophotographic method, Prior to etching the photoconductive layer, it is preferably heat-treated in a fixing step.

If necessary, an overcoat layer that dissolves during etching of the photoconductive layer is provided on the photoconductive layer in the present invention for the purpose of improving the electrostatic characteristics of the photoconductive layer, the developing characteristics during toner development, or the image characteristics. be able to.

Developer (toner) used in electrophotography
Is desirably hydrophobic and ink receptive,
For example, polystyrene-based resins, polyester-based resins (amino group-containing acrylic stells, long-chain acrylic esters, etc.), acrylic resins (resins with phenolic hydroxyl groups or sulfone groups, etc.), epoxy resins, vegetable oil-modified alkyds, cyclized rubbers, asphalt , Polymeric materials such as vinyl chloride are included. Further, a colorant such as carbon black, a nigrosine pigment, carmine 6B, phthalocyanine blue, benzidine yellow, phthalocyanine green or the like may be contained within a range that does not adversely affect the granulation property and the fixing property of the toner, and a charge control agent. For example, a metal salt of fatty acid or naphthenic acid, a metal-containing pigment, a sulfonate and the like can be contained.

In the present invention, JP-A-57-2103 is used.
45, 57-210346, 57-21034.
No. 6, No. 58-194040, No. 58-194404
No. 60, No. 60-6954, No. 61-36759, No. 6
The toner disclosed in JP-A-2-35370 can be used.

The means for forming a toner image is not limited, and any commonly used means can be used.
For toner development, in a carrier liquid consisting of an electrically insulating liquid,
Colorants (carbon black, copper phthalocyanine, etc.),
A material containing a coating agent and a charge control agent, particularly polyethylene, polypropylene or the like is used as the coating agent,
As the charge control agent, it is preferable to use a negative charge control agent composed of a phosphoric acid ester-based surfactant or an electrophotographic liquid developer using a copolymer of acrylic acid, methacrylic acid or their esters.

The etching treatment method to which the etching of the present invention is applied is not particularly limited.
The so-called new liquid supply method described in Japanese Patent Application No. 1-168861, the shower circulation supply method described in Japanese Patent Application Laid-Open No. 58-25477, or the Japanese Patent Application Nos. 2-32010 and 2-966773. There are dipping treatment methods as described above. Of these, the so-called new liquid supply method is preferable.

After the etching process is completed, a rinsing process, a gumming process, and a drying process are completed.
For such a rinse treatment and gumming treatment, reference can be made to JP-A-63-271256 and Japanese Patent Application No. 1-215314. Further, the techniques of rinse treatment and gumming treatment disclosed in the treatment of positive and negative PS plates can be used as they are.

[0077]

EXAMPLES The present invention will be described in more detail below with reference to examples.
The term "parts" means parts by weight unless otherwise specified.

Examples 1 to 35, Comparative Examples 1 to 3 Preparation of photosensitive lithographic printing plate material 3 parts of phenol resin having the following structural formula

[0079]

[Chemical 1] And 0.1 part of maleic anhydride dissolved in 20 parts of propylene glycol monoethyl ether, and then copper phthalocyanine Lionol Blue-ER (ε type copper phthalocyanine) manufactured by Toyo Ink Co., Ltd.
1 part was added and the glass beads were dispersed for 30 minutes to obtain a dispersion liquid.

Next, an aluminum plate of 1100 mm × 400 mm was grained by electrolytic polishing in a hydrochloric acid bath, further anodized and sealed with hot water, and then dried to a thickness of 5 μm. The dispersion was applied and dried to obtain a photosensitive lithographic printing plate material (original plate).

Formation of Toner Image A toner image was formed on the plate surface of this photosensitive lithographic printing plate precursor by an electrophotographic plate making machine of the semiconductor laser exposure system.

A liquid developer manufactured by the following method was used as the developer.

Octadecyl methacrylate / methacrylic acid copolymer (90: 5) 10% Isopar G solution 10 parts MA-100 (carbon black: manufactured by Mitsubishi Kasei) 1 part The above mixture was dispersed with glass beads for 5 hours. Further, 1 part of Sunwax 151P (polyethylene average molecular weight 2000: manufactured by Mitsubishi Kasei) was added to the above dispersion, heated to 80 ° C., and further dispersed for 3 hours. This dispersion was diluted 80 times to obtain a liquid developer.

The fixing condition after development was 130 ° C. for 2 minutes.

Etching Treatment As described above, the photosensitive lithographic printing original plate P on which the toner image was formed was subjected to an etching treatment for eluting the non-image portion by using the processing apparatus shown in FIG.

Description of Processing Apparatus FIG. 1 shows an example of a processing apparatus to which the etching liquid of the present invention can be applied. Detailed explanation of Figure 1 is 1991
Reference may be made to the description relating to the title of the invention “Method and apparatus for manufacturing planographic printing plate” filed on 17th of March.

The processing apparatus shown in FIG. 1 will be briefly described below. A is a first etching portion for performing the first etching treatment step, B is a second etching portion for performing the second etching treatment step, C is a first rinsing portion for performing treatment with a rinse liquid,
D is the second rinse portion, E is the gumming portion that protects the printing plate, F
Is the dry part.

An apparatus G for exposing the photoconductive layer portion of the photosensitive lithographic printing original plate P to form a toner image is arranged in the preceding stage of the processing apparatus shown in FIG.
Is processed while being guided by the entrance carry-in roller and being carried along the carrying path indicated by the phantom line.

The etching solution is supplied from the stock solution tank 1 to the pump 2
Is supplied to the first etching unit A through the supply pipe 6 after being introduced into the dilution tank 3 and stirred with the dilution water introduced from the dilution water tank 4 to be diluted to a specified concentration.

In FIG. 1, 7 to 9 are rollers,
10 is a pool of etching liquid, 11 is a guide member, 12
Is a liquid guide roller, 14 is a pan, 15 and 16 are rollers, 17 is a dip tank, 18 is a transfer roller, 19 is a guide roller, 20 is a brush roller, 21 is a lower surface support member, 22-squeeze roller, and 23 is a squeeze roller. , 24 is a liquid receiving part, 25 is a filter, 26 is a pump, 27 is a shower nozzle, 28 is a brush roller,
29 is a brush roller.

The etching liquid supplied through the supply pipe 6 is introduced through the slit inside the guide member 11 so as to be uniformly applied to the surface of the liquid guide roller 12, and is rotated on the roller 8 for its rotation. It flows down the surface in a reverse shape and is guided to the liquid pool 10.

In this example, as the guide member 11, a synthetic resin film having a thickness of 175 μ for the lower side and 100 μ for the upper side was used.

The eccentric angle α between the rollers 7 and 8 was set to -8 degrees, and the eccentric angle β between the roller 8 and the liquid guide roller 12 was set to 10 degrees.

The brush roll 20 in the second etching section B has a roll diameter of 40 mmφ and nylon 6/12 having a thickness of 0.05 mmφ is planted in a channel-shaped member so that the bristle length is 12 mm. A member was wound around a roller core, and a so-called channel brush was used to rotate the member so that the peripheral speed was 14 m / min.

As the transport roller 15, three rollers at both ends and the center are used.
A roller that nips the place with a width of 10 mm was used.

As the transport roller 18, a roll diameter of 100 mm
A disc-shaped EPT rubber with a hardness of 40 degrees and a diameter of 10 was cut to a thickness of 10 mm and attached to the shaft at 100 mm intervals.

Etching Solution An etching solution having the composition shown in Table 1 was adjusted to 27 ° C. and used. The unit of the blending amount of each composition represents% by weight.

The supply rate of the etching solution was 400 cc / min from the supply pipe 6, and the transport speed was adjusted so that the etching time (sec) was as shown in Table 1.

The etching solution applied on the plate surface of the photosensitive lithographic printing original plate P in the first etching section A is
It was 180cc / m ² .

Further, each of the etching solutions was adjusted so that the surface tension was in the range of 32 to 36 dyne / cm. The coatability was good in all cases.

However, Example 26 had a surface tension of 49 dyne / cm.
In Example 27, the surface tension was 30 dyne / cm.

The pH of each etching solution was adjusted to 13.05 by adding a KOH solution. However, Example 23 had pH 12.90, and Example 24 had pH 13.
Adjusted to 20.

Under the above-mentioned processing conditions, 100 plate photosensitive lithographic printing original plate P was continuously processed, and the following evaluations were carried out.

Adhesion of Photoconductive Layer Components to Grain Grains were visually evaluated according to the following evaluation criteria. ◎: Not seen at all ○: Not seen △: Seen ×: Pretty seen

Precipitation According to the following evaluation criteria, the dip tank 17 and the liquid receiving section 2
The state of occurrence of precipitation in the liquid of No. 4 was visually evaluated. ◎: No occurrence ○: No occurrence △: Occurrence ×: Significant occurrence

Adhesion of Stain to Roller The state of adhesion of stain to the squeeze roller was visually evaluated according to the following evaluation criteria. ◎: Not seen at all ○: Not seen △: Seen ×: Pretty seen

Staining on Printing Staining on printed matter was visually evaluated according to the following evaluation criteria. ⊚: not seen at all ◯: not seen Δ: seen ×: considerably seen Table 1 shows the above evaluation results.

[0108]

[Table 1]

[0109]

[Table 2]

[0110]

[Table 3]

[0111]

[Table 4]

[0112]

[Table 5]

[0113]

[Table 6]

[0114]

[Table 7]

[0115]

[Table 8]

As is clear from Table 1, in the case of this embodiment, the photoconductive layer component did not adhere to the sand in the shortest etching time, and the liquid in the dip tank 17 and the liquid receiving portion 24 was not changed. No precipitation occurred inside the shower 27
No clogging occurred, and no stain was attached to the squeeze roller. Regarding the adhesion of stains to the printed matter, the generation of stains was not recognized in the printing test using any plate.

On the other hand, in the etching solution of the present invention, in Comparative Example 1 in which the organic solvent of the present invention was not used, the adhesion of the photoconductive layer component to the sand and the squeeze roller were not well adhered.

In Comparative Example 2 in which the aromatic carvone of the present invention was not used, the adhesion of the photoconductive layer component to the grain was good, but the occurrence of precipitation, the adhesion of dirt to the squeeze roller, The stains on the printed matter were all bad.

Furthermore, in Comparative Example 3 in which the organic solvent and aromatic carvone of the present invention were not used, the adhesion of the photoconductive layer component to the sand, the occurrence of precipitation, the adhesion of dirt to the squeeze roller, and the adhesion of dirt to the printed matter. None of the situations were pretty bad.

Example 36 and Comparative Example 4 Instead of the processing apparatus used in Example 1, JP-A-58-254 was used.
The processing device described in No. 77 was replaced. That is, the first embodiment is an example in which the etching liquid is supplied by a so-called new liquid supply method, but this embodiment is a system in which the etching liquid is supplied by a shower and circulated. As the etching solution, the solution used in Example 2 was used after adjusting the temperature at 27 ° C. 20 ml / m ² supplied to the printing plate
Adjusted to. Water was used as the rinse liquid in the first and second rinse steps. In the same manner as in Example 1, the printing plate on which the toner image was fixed was subjected to continuous processing for 100 plates in total while replenishing 50 cc of the etching liquid per plate.

For comparison, the same treatment was carried out except that the etching solution used in the above-mentioned Example was replaced with the solution used in Comparative Example 2.

When evaluated in the same manner as in Example 1, the following results were obtained.

Example 36 Comparative Example 4 Etching Time 18 22 Adhesion of Photoconductive Layer Component to Grain ◯ ○ Precipitation Occurrence ○ △ Adhesion of Stain to Roller ○ ○ to △ Adhesion of Stain to Print ○ ○ to △

Example 37 Continuous treatment was carried out in the same manner as in Example 1 except that the photosensitive lithographic printing plate material produced as described below was used and the etching solution was changed to that used in Examples 2 and 6. .. As a result, the same good result was obtained.

(Production of Photosensitive Lithographic Printing Plate Material)
No. 8-207049, the photoreceptor solution obtained in Example 23 was applied and dried on the support of Example 1 to a film thickness of 5 μm when dried, and the printing plate obtained was charged, and then exposed to a camera.
Further, a toner image was formed and fixed in the same manner as in Example 1.

[0126]

According to the present invention, firstly, the photoconductive layer component can be prevented from remaining, the etching speed can be improved, secondly, precipitation can be prevented, and thirdly, rollers such as conveying or squeezing can be prevented. It is possible to provide an etching solution for an electrophotographic printing plate, in which stains are generated, and thus maintainability is not deteriorated, and stains in printing are not generated.

[Brief description of drawings]

FIG. 1 is a schematic view of a processing apparatus to which an etching solution for electrophotographic printing plates of the present invention can be applied.

[Explanation of symbols]

 A-First etching processing section B-Second etching processing section C-First rinsing section D-Second rinsing section E-Gumming section F-Drying section G-Toner image forming apparatus P-Photosensitive lithographic printing original plate 1- Undiluted solution tank 2-Pump 3-Diluting tank 4-Diluting water tank 5-Pump 6-Supply pipe 7-Roller 8-Roller 9-Roller 10-Liquid reservoir 11-Guide member 12-Liquid guide roller 14-Saucepan 15-Roller 16 -Roller 17-Dip tank 18-Conveying roller 19-Guide roller 20-Brush roller 21-Lower surface support member 22-Squeeze roller 23-Squeeze roller 24-Liquid receiving section 25-Filter 26-Pump 27-Shower nozzle 28-Brush roller 29-brush roller

Claims (1)

Claim: What is claimed is: 1. A toner image is formed on a lithographic printing plate material in which a photoconductive layer containing an organic photoconductive compound is provided on a conductive support by an electrophotographic method, and then a non-image is formed. Is an etching solution for removing the photoconductive layer of a part, which is characterized by containing an alkaline agent, an organic solvent having a solubility in water at 20 ° C of 10% by weight or less, and an aromatic carboxylic acid or a salt thereof. Etching liquid for photo printing plates.