JPS5925217B2 - How to form a printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel printing original plate and a method for forming a printing plate using this printing original plate.

More specifically, it is a printing original plate having a recording layer containing a specific phenolic resin as a main component, and a toner image is formed on this recording layer by developing with a liquid development method, or a toner image is recorded through a transfer process. The present invention relates to a method of forming a printing plate by etching after forming a toner image on a layer. Conventional printing plates include, for example, silver photosensitive materials, photosensitive resins, photoreceptors in which inorganic photoconductive materials such as zinc oxide are dispersed in resin, and photoreceptors in which organic photoconductive materials are mixed with resin. It has been known.

However, printing plates made on the basis of diffusion transfer development of silver sensitizers have the disadvantages of high cost per sheet and lack of printing durability.

In addition, printing original plates using photosensitive resins have significantly lower sensitivity than photoconductive photoreceptors or silver photosensitive materials used in electrophotography, and require a strong light source and long exposure, so-called photoreceptors. It has drawbacks such as the inability to perform direct plate making.

Furthermore, a method in which the photosensitive printing plate is responsible for photosensitive printing and the photosensitive printing original plate is responsible for printing durability or printing suitability, that is, a method that combines both, is disclosed in JP-A-50-1801;
This can be found in Publication No. 143408, etc.

After transferring the toner image, this method crosslinks the photosensitive resin layer by exposing the entire surface to light and removing the toner image area, but it requires a full-surface exposure process, requires a strong light source, and is difficult to create a printing plate. There are disadvantages such as the time required for the process. Examples of original printing plates using electrophotography include Japanese Patent Publications No. 47-47610, No. 48-40002, No. 48-18325, No. 51-15766, and No. 51-
A zinc oxide-resin dispersion type offset printing original plate is known, which is described in Japanese Patent No. 25761, etc., and after forming a toner image by basket photography, a non-sensitized resin is applied to the non-image area to form an insensitive fat box. It is used after being wetted with a chemical solution (for example a ferrocyanate or an aqueous acid solution containing a ferrocyane salt).

Offset printing plates formed by such treatment have a printing durability of about 5,000 to 10,000 sheets, and are not suitable for printing beyond this, and if the composition is suitable for desensitization, they become static. There are disadvantages such as deterioration of electric characteristics and deterioration of image quality. Furthermore, Special Publication No. 37-17162, No. 38-
JMo V58, No. 46-39405, JP-A-52-24
In the organic photoconductor-resin printing original plate described in Publication No. 37, for example, a photoconductive insulating layer in which oxazole or oxydiazole is bonded with a styrene-maleic anhydride copolymer is coated with grained aluminum. A photoreceptor provided on a clay plate is used, and after a toner image is formed on the photoreceptor by electrophotography, a printing plate is formed by dissolving and removing the non-image area with an alkaline organic solvent.

To form this printing plate, an organic solvent such as ethylene glycol, glycerin, methanol, or ethanol is required as a processing liquid to dissolve and remove the photoconductive insulating layer, and this requires an organic solvent such as ethylene glycol, glycerin, methanol, or ethanol, from the viewpoint of cost, safety, pollution, occupational health, etc. undesirable. In addition, it requires a sensitizer such as a polymethine dye, and even if a sensitizer is used, it does not show sensitivity sufficient for practical use in the long wavelength region of 600 mμ or more. For example, when recording with inexpensive He-Ne laser light, The disadvantage is that sufficient image recording cannot be performed. Furthermore, it is unsatisfactory in terms of resolution, adhesion, etc., cannot reproduce fine images, has poor humidity dependence, electrostatic characteristics change easily due to changes in humidity, and has poor storage conditions due to poor charge preservation. It has disadvantages such as not being good.

The above-mentioned Japanese Patent Application Laid-Open No. 52-2437 contains several articles about phenol, but mainly the binder is a styrene-maleic anhydride copolymer.
The type of phenolic resin used as a binder, the casting material, and the structure of each compound are not described. On the other hand, liquid developers are generally used as a developer for electrostatic latent images to create printing plates because high-resolution images can be obtained by fine particle development, reversal development is possible, and the development device is simple. It is being

A liquid developer is formed by dispersing a toner consisting of a colorant, a fixing agent, a charge control agent, etc. in a carrier liquid, and the carrier liquid has a specific resistance of 109Ω? Aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halodenated hydrocarbons, polymethylsiloxane, etc., which have electrical resistances as low as Phenomena such as deterioration or images blurring and becoming unclear are often observed.

It is known that such a phenomenon not only causes deterioration of the developer, but also poses a significant problem in obtaining a clear, high-resolution toner image. An object of the present invention is to provide a printing original plate that is not affected by the carrier liquid of a liquid developer and is therefore capable of producing clear images.

A further object of the present invention is to provide a printing original plate having excellent sensitivity, charge retention, moisture resistance, and electrostatic characteristics.

Still another object is to provide a printing original plate that can be charged in both positive and negative polarities and is capable of positive-positive and negative-positive plate making using one type of developer.

Still another object is to provide a printing original plate having a recording layer that is easily soluble in an alkaline aqueous solution. The above purpose is to use a printing original plate having a recording layer on a hydrophilic substrate soil for obtaining a toner image mainly composed of a phenolic resin having a structural unit represented by the following general formula [1]. Forming a printing plate by forming a toner image on the recording layer by a liquid development method, applying a necessary force to heat fixing the toner image, and dissolving and removing the recording layer in the area where the toner image does not exist using an alkaline bending solution. This is achieved by using a method.

[In the formula, R1 is an aryl group or a furfuryl group; R2
, R3 and R4 are a hydrogen atom, a halogen atom, a hydroxy group, a nitro group, an amino group, a carboxylic acid group or a salt thereof, a sulfo group or a salt thereof, and each has 1 to 1 carbon atoms.
20 alkyl groups, alkoxy groups, alkoxy-alkyl groups, alkylcarbonylalkyl groups or acyl groups,
Or it represents a hydrocarbon group having 4 to 14 carbon atoms.

However, when at least one of R2, R3 and R4 represents a group having 4 or more carbon atoms, at least one of R2, R3 and R4 represents a hydrophilic injecting functional group or a group substituted with a hydrophilic functional group. represents.

] The hydrophilic functional groups include a hydroxy group, an amino group,
Typical examples include a carboxy group or a salt thereof, or a sulfo group or a salt thereof.

That is, by configuring the present invention in this manner, the following effects can be achieved. For example, a liquid developer is used to make an electrostatic latent image formed on a printing original plate into a visual image. For this reason, a toner image with high resolution can be obtained, and the recording layer uses a phenolic resin as a main component that has a specific structure that is not attacked by liquid developers, so the image may be distorted or the recording layer may be damaged. There is no softening and deformation, no deterioration of the developer, and there is an effect that a printing plate with excellent printing durability and high resolution can be obtained. Further, the recording layer of the present invention may be only a phenolic resin layer as described above, or may be a layer containing a photoconductive material, and may be positive or negative depending on the characteristics of the specific phenolic resin used. Both types of charging are a matter of course, and the ability to form a positive-positive or negative-positive printing plate with one type of developer is the key. Further, since the resin of the present invention has an alkaline weld, areas other than the toner image can be easily dissolved and removed without heat treatment, and sharp corrosion processing can be performed.

In the plate making method of the present invention, an electrostatic charge image is formed in advance on another recording material, this is electrostatically transferred to the printing master plate of the present invention, this electrostatic charge image is made into a toner image by liquid development, and this is converted into an alkali image. Although the process includes plate making by etching with a liquid, the specific phenolic resin of the present invention has an excellent charge retention range, so it is possible to easily form a transferred electrostatic charge image. The printing original plate of the present invention can also be advantageously used in the case where a toner image is previously formed on another recording material and the toner image is transferred onto the recording material of the present invention for plate making. It will be done.

Next, as the phenolic resin used as the main component of the binder resin of the printing original plate of the present invention, the phenolic resin having the structural unit represented by the general formula [D] and other phenolic resin monomers It is a co-condensation with a body, and includes, for example, those modified with epoxy resin, polyvinyl alcohol, etc.

Furthermore, the average molecular weight of the phenolic resin used in the present invention is 2.
40-20,000, preferably 350-600
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetic acid, dioxane, butyl acetate, and ethyl acetate. Those soluble in solvents such as esters are desirable. Examples of compounds that can be effectively used in the present invention include the following.

However, m and n represent the polymerization molar ratio, and M represents the average molecular weight.

As the photoconductor used in the present invention, at least one of inorganic photoconductors, organic photoconductors, and photoconductively bent organic pigments can be used.

Examples of inorganic photoconductors include zinc oxide, cadmium sulfide, titanium oxide, selenium, cadmium selenide, zinc selenide or lead oxide, and examples of organic photoconductors include substituted vinyl oxides, such as 2-vinyl- 4-(2'
-chlorophenyl)-5-(4''-diethylaminophenyl(c)-oxazole or triphenylamine derivatives, higher condensed aromatic compounds such as anthracene,
benzo-fused complex, birazoline or imidazole derivatives, such as 1-phenyl-3-(p-diethylaminostyrino(ha)-5-(p-diethylaminophenyl))pyrazoline or triazole, oxadiazole derivatives such as 2,5-bis -(4'-diethylaminophenyl)-1,3,4-oxaneazole or vinyl aromatic polymers such as polyvinylanthracene, polyacenaphthylene poly-N-vinylcarbazole and copolymerization products consisting of these compounds or 2 ,4,7
-trinitro-9-funobiolenone, 2,4,5,7-
Examples include tetranitrofluorenone, polyarylalkane, triarylmethane leuco dye, squaric acid derivative dye, and 2,4,8-trinitrothioxanthone. Next, among the photoconductive organic pigments used in the present invention, phthalocyanine pigments are
No. 780, No. 45-8102, No. 45-11021, No. 46-42511, No. 46-42512, No. 4
No. 8-163, No. 49-17535, No. 50-505
It is a photoconductive phthalocyanine pigment described in No. 9 and JP-A No. 50-38543, etc., and has the general formula (C8
H4N2)4R'n, where R' is a hydrogen atom, eutherium, sodium, potassium, copper, silver, beryllium, magnesium, calcium, zinc, cadmium, barium, mercury, aluminum, potassium indium lanthanum neodymium SS) murium europium cadmium dyspro) S) sium, holmium,
Erbium, thulium, ytterbium, ruthenium,
Titanium, tin, hafnium, lead, thorium, vanadium, antimony chromium, molybdenum, uranium, manganese,
Iron, cobalt nickel rhodium palladium male))))mium and platinum, and n is O~2.

Among these, Alpha 1 (Ct!i, Beta @
, gamma (γ), pi (π), ex (4), and epsilon (ε) type metal-free phthalocyanines or metal phthalocyanines such as copper, cobalt, lead, zinc, etc. are preferred. Examples of azo pigments include JP-A Nos. 51-90827 and 52
Among the photoconductive curved azo pigments described in Japanese Patent No. 55643 and the like, monoazo pigments represented by the following general formula and disazo pigments represented by the following general formula are used in the present invention.

General formula mill U In the formula, Z is -NO2, -CNl-Ct, -Brl-H1-
CH3, -0CH3, -0C2H5, -0H, -N(C
Represents an atom or group such as 2H5)2.

General formula [] In the formula, A is or and R5 and R6 are lower alkyl groups.

X and Y are -NO2, -CNl-H1-CH3, -0C
H3, -0C2H5, -ON1-Ctl-Brl-N(
Represents an atom or group such as C2H5)2. Among the compounds represented by the above general formulas and diagrams, Diane Blue, which is a type of cis-sazo pigment, is particularly preferred. As the quinacridone pigment, for example, a quinacridone pigment described in JP-A-49-30332 and represented by the following general formula, which may have a substituent as necessary, is used in the present invention.

General formula [] Among the pigments represented by the above general formula, it is particularly beta-1 (β and gamma-1 (γ) linear trans-quinacridone, unsubstituted trans-quinacridone and substituted with a methyl group or a chlorine atom). Trans-nacridones are preferred.

As a bisbenzimidazole pigment, for example, JP-A-4
Among the bisbenzimidazole pigments described in Japanese Patent No. 7-18543, a trans-type compound represented by the following general formula and a cis-type pigment represented by the following general formula are used in the present invention.

General formula [and each of R7 and R8 represents one to four substituents selected from an optionally substituted alkyl group, an optionally substituted aryl group, a halogen atom, a nitro group, and an amino group, When there are multiple groups, they may be the same or different. Furthermore, the substituents R7 and R8 may form a condensed ring together with the benzene nucleus. Besides this, 1, 4, 5,
Pigments having a heterocycle produced by the reaction of naphthalene carboxylate and a heterocyclic diamine can also be effectively used in the present invention.

As an indigo pigment, for example, JP-A No. 47-30, 33
Trans-indigo pigments represented by the following general formula [] and cis-indigo pigments represented by the following general formula [] described in Publication No. 1 are used in the present invention.

General formula [] In the general formula [] and [], R is an alkyl group,
A 5-aryl group, amino group, or halodane atom,
A and B are -NH- -0- -S- -Se-SSS
and -Te-, and the substituents may be the same.

Among these, unsubstituted indigo in which A and B are an NH group or an S atom is particularly preferred. As the pigment, for example, a polyalquinone pigment described in JP-A-47-18544 is used in the present invention, preferably andanthrone, general formula [vilanthrone], dibenzpyrenequinone, pyrenequinone, 3 , 4,9,10-dibenzpyrenequinone, brominated andanthrone, brominated dibenzpyrenequinone, brominated bilanthrone, anthraquinone thiazole, furanthrone, and the like.

As perylene pigments, for example, JP-A-47-130,33
Pigments represented by the following general formula [] and the following general formula [X] described in Publication No. 0 and US Pat. No. 3,871,882 are used in the present invention. In the formula, Q is an alkyl group, an aryl group, an alkylaryl group, an alkoxy group
It is a heterocyclic substituent or a halogen atom. In the formula, D is a chlorine atom or a methoxy group.

As the quinoline pigment, for example, a quinoline pigment represented by the following general formula described in JP-A-49-1231 is used in the present invention. In the formula, F represents an iodine atom or a bromine atom, E represents a quinoline ring, and t represents 0, 1, 2, 3.

As a cyanine pigment, for example, JP-A-47-137,54
Those represented by the following general formula described in Publication No. 4 are used in the present invention.

In the formula, R77 is a methyl group, an ethyl group, or an allyl group,
is a chlorine atom, a bromine atom or an iodine atom, G and L are an oxygen atom, a sulfur atom or a selenium atom, and A is a hydrogen atom, a methyl group or an ethyl group.

As pyrylium salt pigments, for example, Japanese Patent Publication No. 462251
No. 9, No. 46-22518, etc., and those represented by the following general formula can be used in the present invention.

where Ra, Rb, RC, Rd and Re are each a hydrogen atom; typically an aliphatic or aromatic group having 1 to 15 carbon atoms, such as methyl, ethylpropyl isopropyl butyl t-butylamyl isoamyl hexyl octyl nonyl dodecyl Styryl Methoxystyryl Diethoxystyryl Dimethylaminostyryl 1-Butyl-4-p-dimethylaminophenyl-1,3-butadienyl, β-ethyl-4-dimethylaminostyryl, etc.; methoxy, ethoxy, propoxy, butoxy , amyloxy, hexoxy, octoxy, and other alkoxy groups; phenyl 4-diphenyl, alkylphenyls (4-ethyl phenyl, 4-propylphenyl, etc.), alkoxy diphenyls (4-ethoxyphenyl, 4-methoxyphenyl, 4-methoxyphenyl, 4-methoxyphenyl, etc.) -amylodiphenyl, 2hexoxyphenyl, 2-methoxyphenyl,
3,4-dimethoxyphenyl, etc.), β-hydrosialkoxyphenyl (2-hydroxyethoxyphenyl,
4-hydroxyphenyl, halophenyl (2,4-dichlorophenyl,
3,4-dipromophenyl, 4-chlorophenyl, 2,
4-dichlorophenyl, etc.), acidophenyl, nitrophenyl, aminoyls (4-diethylaminophenyl, 4-dimethylaminophenol, etc.) and naphthyl;
represents vinyl, etc.; where M is a sulfur atom, oxygen atom, or selenium atom, and Z is an anionic functional group (berchlorate, fluoroborate, iodate, chloride, bromide, sulfonate, sulfonate, baryodate, (including p-toluenesulfonate, etc.).

Furthermore, the pair Ra and RbO and the pair Rd and Re represent the atomic groups necessary to complete the closed aryl destruction to produce the pyrylium nucleus upon excitation.

The electrophotographic printing original plate of the present invention can also be effectively used as a laminated type electrophotographic printing original plate formed by laminating a charge generation layer and a charge transport layer.

In the electrophotographic printing original plate of the present invention, a dye sensitizer or a chemical sensitizer can be used.

Examples of dye sensitizers that can be used include malachite green, crystal violet, methyl violet, Victoria blue, Rhodamine B, Capriblue, methylene blue, fuchsin, rose bengal, polymethine pigments, and thiosanthene pigments.

Examples of chemical sensitizers include p-benzoone, 2,5
- Zigyama lebenzoquinone, benzophenone tetracarboxylic acid dianhydride, 2,6-dichlorobenzoone, chloranil, naphthoquinone 1(1,4), 2,3
-JikororenaJagquinone 1(1,4), anthraquinone, 2-methylanthraquinone, 1,4-dimethyl-anthraquinone 1-chloroanthraquinone, anthratonone-2-carboxylic acid 1,5-dichloroanthraquinone 1 -Chlor-4-nitroanthraquinone)Sphenanthrene-quinone acenaphthene-quinone S)quinones such as pyrandrenequinone, chrysene-quinone, thionaphthene-quinone, anthraquinone-1,8-disulfonic acid and anthraquinone-2-aldehyde; Phthaloyl benzenes, such as promal, 4-nitrobenzaldehyde, 2,6-dimethylbenzaldehyde, 2-ethoxy-1-naphthaldehyde, anthracene-9-aldehyde, pyrene-3-aldehyde oxindole-3
-Aldehydes Aldehydes such as pyridine-2,6-di)aldehyde and biphenyl-4-aldehyde; Organophosphoric acids such as 4-chloro-3-nitrobenzene-phosphonic acid; For example, 4-nitrophenol Nitrophenols; Bicric acid; For example, acetic anhydride, succinic anhydride, maleic anhydride, 7-talic anhydride, tetrachlorophthalic anhydride, pyrene-3,4,9,) 10
-tetracarboxylic acid and chrysene-2,3,8,9
Anhydrous acids such as monotetracarboxylic anhydride; 1 of the periodic table
B1 group to group metals and metalloids, such as aluminum chloride, zinc chloride, ferric chloride, tin tetrachloride (stannic chloride), arsenic trichloride, stannous chloride, antimony pentachloride, Magnesium chloride, magnesium bromide,
Calcium bromide, calcium iodide, strontium bromide, chromium bromide, manganese chloride, cobaltous chloride, ferric chloride, cupric bromide, cerium chloride, thorium chloride, arsenic triiodide boron halide compounds such as boron trifluoride and boron trichloride; examples include acetophenone, benzophenone, 2-acetyl-naphthalene, benzoin, 5-benzoylacena
Acetyl-e anthracene 9-benzoyl-anthracene S) 4-(4-dimethylamino-cinnamoyl)-
1-acetylbenzene acetoacetate acid)-
Included are ketones such as anilide, indandione (1,3), acenaquinone dichloride, anisyl, 2,2-pyridyl, and furyl.

Further Lewis acids include mineral acids such as hydrogen halides, sulfur and phosphoric acid; for example acetic acid and its substitution products, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, aurinetricarboxylic acid, phenylacetic acid and 6-methylcoumaric acid. Organic carboxylic acids such as nyl acetic acid (4); maleic acid, cinnamic acid, benzoic acid, 1-(4-diethylaminobenzoyl)benzene-2-carboxylic acid, phthalic acid,
Tetratacho phthalic acid, α-β-dibromo-β-formyl-acrylic acid (mucomonobromic acid), dibromo-maleic acid, 2-bromobenzoic acid, gallic acid, 3-nitro-2-
Hydrogenyl-benzoic acid, 2-nitrophenoxyacetic acid, 2-nitro-benzoic acid, 3-nitro-benzoic acid, 4
-Nitro-benzoic acid, 3-nitro-4-ethoxybenzoic acid, 2-chloro-4-nitro-1-benzoic acid, 3-nitro-4-methoxybenzoic acid, 4-nitro-1-methyl- Benzoic acid, 2-chloro-5-nitro-1-benzoic acid, 3-chloro-6-nitro-1-benzoic acid, 4-ku-machi 3-nitro-1-benzoic acid, 5-ku-cho-rei 3-Nitro-2-hydroxy-benzoic acid, 4-nitro-2-hydroxy-benzoic acid, 2,4-dinitro-1-benzoic acid, 2
-Bromo-5-nitro-benzoic acid, 4-chlorophenyl monoacetic acid, 2-chlorine cinnamic acid, 2-cyano-cinnamic acid, 2
, 4-dichloro-benzoic acid, 3,5-dinitro-benzoic acid, 35-dinitro-salicylic acid, malonic acid, mucinic acid,
Acetosalicylic acid, benzylic acid, butane-tetracarboxylic acid, citric acid, cyanomonoacetic acid, cyclohexane-dicarboxylic acid, cyclohexane-dicarboxylic acid, 9,10-dichloro-stearic acid, fumaric acid, itaconic acid, levulinic acid, apple Acid, succinic acid, α-bromo-stearic acid, citraconic acid, dibromo-succinic acid, pyrene-2,3
, 7,8-tetracarboxylic acid, tartaric acid; e.g. 4-toluene-sulfonic acid, benzene-sulfonic acid, 2,4-dinitro-1-methyl-benzene-6-sulfonic acid 2,
6-dinitro-1-hydroxy)-benzene-4-sulfonic acid, 2-nitro-1-hydroxy-benzene-4-
Sulfonic acid 4-nitro-1-hydroxy-2-benzene-sulfonic acid, 3-nitro-2-methyl-1-hydrobenzene-5-sulfonic acid 6-nitro-4-
methyl-1-hydroxy-benzene-2-sulfonic acid, 4-chloro-1-hydro-benzene-3-sulfonic acid, 2-chloro-3-nitro-1-methyl-benzene-5-sulfonic acid and Contains organic sulfonic acids such as 2-chloro-1-methyl-benzene-4-sulfonic acid.

The phenolic resin of the printing original plate of the present invention may be compatible with other resins, such as styrene-maleic anhydride copolymer, silica, epoxy resin, acrylic resin, polyvinyl acetate, acetyl butyl cellulose, polyvinyl alcohol, gelatin, etc. ) It can be used in combination with SS zein or a phenolic resin that does not belong to the present invention.

However, it is preferable that the phenolic resin, which is a structural unit of the present invention, is contained in an amount of 50 mol% or more based on the amount of the binding resin. Further, the phenolic resin for printing plates of the present invention may contain a plasticizer.

i:i] The plastic agent is effective for making the recording layer provided on the support have the desired flexibility, and examples include dimethyl phthalate, diethyl chloride, dibutyl phthalate, dioctyl Phthalate O SS Cutyl capryl phthalate, dicyclohexyl J charate Ditridecyl phthalate Butylbe S
) Diisodecyl phthalate Di-XS
Phthalate esters such as aryl phthalate, dimethyl glycol phthalate, ethyl phthalyl-ethyl glycolate, methylptaryl ethyl glycolate, glycol esters such as butylphthalyl butyl glycolate, triethylene glycol dicaprylate, tricresylphos J phosphate, phosphoric acid esters such as triphenyl phosphate, diisobutyl adipate,
Dioctyl adipate dimethyl sebacate Djibouti)
S Lucevacate Diotatylacelate Dibutyl SS
Fatty acid dibasic acid esters such as maleate, polyglycidyl methacrylate triethyl citrate, glycerin triacetyl ester, butyl laurate, etc. are effective.

These plasticizers mentioned above can be contained within a range that does not deteriorate the electrostatic properties or the alkali dissolution range of the recording layer.

Printing plate material substrates that are effective in the present invention include offset printing base paper, aluminum plates, zinc plates, bimetal plates such as copper-aluminum plates, copper-stainless steel plates, chrome-copper plates, etc.
Alternatively, an electric insulating, low resistance or conductive board with hydrophilic properties such as tri-metal plates such as Tarom copper-aluminum plate, chromium copper-iron plate, chromium copper-stainless steel plate, etc. is used. A conductive substrate or a low resistance substrate having a surface is preferably used.

In addition, especially in the case of a support having an aluminum surface, surface treatments such as graining treatment; immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, etc., or anodization treatment are performed. It is preferable.

In addition, as described in U.S. Pat.
As described in the above publication, an aluminum plate which is anodized and then immersed in an aqueous solution of an alkali metal silicate is also preferably used. The above-mentioned anodizing treatment may be performed using an electrolytic solution, for example, an aqueous or non-aqueous solution of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, boric acid, etc., or an organic acid such as oxalic acid, sulfamic acid, or a salt thereof, or a combination of two or more thereof. This is carried out by passing an electric current through the aluminum plate as an anode. Also, U.S. Patent No. 36586
Silicate electrodeposition as described in No. 62 is also effective.

Treatment with polyvinylphosphonic acid as described in DE 1621478 is also suitable. These hydrophilic treatments are performed not only to make the surface of the support hydrophilic, but also to prevent harmful reactions with the recording layer provided thereon, and to improve adhesion with the recording layer. It is performed for the purpose of Further, in the present invention, casein, polyvinyl alcohol, etc. may be used between the hydrophilic surrounding substrate and the recording layer as necessary.
For the purpose of improving the adhesion between the support and the recording layer or the electrostatic characteristics of the recording layer, an intermediate layer of an alkaline material made of ethyl cellulose, phenolic resin, styrene-maleic anhydride copolymer, polyacrylic acid, etc. can be provided. In addition, in the present invention, an overcoat layer that dissolves when the recording layer is removed is provided on the recording layer, if necessary, for the purpose of improving the electrostatic characteristics of the recording layer, the development characteristics during toner development, or the image ejection characteristics. be able to.

This overcoat layer may be mechanically matted or a resin layer containing a matting agent. Matting agents include silicon dioxide, zinc oxide, titanium oxide, zirconium oxide, glass particles, alumina, starch,
Included are polymeric particles (eg, particles of polymethyl methacrylate, polystyrene, phenolic resins, etc.) and matting agents as described in US Pat. No. 2,701,245 and US Pat. No. 2,992,101. Two or more of these can be used in combination. The resin used for the resin layer containing the matting agent is appropriately selected depending on the combination with the recording layer removing liquid used. Specifically, examples include gum arabic, glue, gelatin, casein, cellulose (such as viscose, methylcellulose, ethylcellulose)
hydroxy SS diethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, etc.),
Starches (for example, soluble starch, inflexible starch, etc.), polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyacrylamide, polyvinyl methyl ether, epoxy resin, phenolic resin (particularly preferred is novolak type phenolic resin), polyamide , polyvinyl petyral, etc.

Two or more of these can be used in combination. In order to produce the printing original plate of the present invention, for a recording layer or a transfer body that does not require photo-sensitivity, the phenolic resin of the present invention is suitably dissolved in the above-mentioned organic solvent, and then the phenol resin of the present invention is disposed on the hydrophilic curved substrate to a thickness of 1 to 50 μm. (preferably 1 to 15 microns thick) is coated and dried.

It is also possible to use polymer powder or pigment dispersed in such a recording layer. To produce an original plate for electrophotographic printing, 1 part by weight of the photoconductor is mixed with 0.0 part of the phenolic resin.
1 to 100 parts by weight (preferably within a range where the photoconductive insulating layer can be dissolved and removed).

) mixed with ethylene glycol monoethyl ether
Methyl ethyl ketone acetone, halodane hydrocarbon,
The hydrophilic substrate is suitably dissolved in an organic solvent such as toluene, tetrahydrofuran, or ethyl acetate, or if the photoconductor is not dissolved, it is substantially uniformly dispersed using a homogenizer or an ultrasonic disperser. 1-5 on top
It is prepared by coating and drying to a thickness of 0 μm, preferably 1 to 15 μm. Further, in the present invention, a printing original plate in which a recording layer in which an organic pigment, particularly a phthalocyanine pigment, is dispersed in a phenolic resin according to the present invention is provided on a hydrophilic substrate is suitable for the purpose of the present invention.

That is, a photoconductive injected phthalocyanine pigment, for example an α, β, γ, π, ε or χ type phthalocyanine pigment, is added to the phenolic resin shown by the general formula above, and 1 to 50 parts by weight of the resin is added to 1 part by weight of the pigment. A recording layer containing dispersed particles in a dry film thickness of 1 to 15 μm is deposited on a grained, hydrophilic aluminum, zinc or copper-aluminum plate, for example.
The original plate for printing is created by coating it so that it becomes .

This printing original plate has high sensitivity even though the resin is richer than the pigment, and the particles are extremely fine, making it possible to obtain extremely sharp toner images. In addition, since the resin is richer than the pigment, it has excellent effects such as being resistant to electric shock from cokana discharges or needle electrodes, and does not damage the recording layer, and is also capable of being charged both positively and negatively. be able to.

Various coating methods are available, including dip coating, air knife coating, bead coating, curtain coating, and extrusion coating using a hopper as shown in US Pat. No. 2,681,294. The developing methods used in the present invention include a dry method using a developer in which both the toner and the carrier are solid, a wet method using a developer in which the toner or carrier is a liquid, and a wet method in which the toner or carrier is a liquid. Although there is an aerosol development method in which an air stream is used as a carrier, a liquid development method is preferable in order to obtain an image with high resolution.

The toner used in the present invention is preferably hydrophobic and ink-receptive, and examples thereof include polystyrene resins, polyester resins (acrylic esters containing amino groups, long-chain acrylic esters, etc.), acrylic resins (phenolic hydroxyl groups, etc.). They include polymeric substances such as epoxy resins, vegetable oil-modified alkaline resins, ape rubber, asphalt, and vinyl chloride.

In addition, colorants such as carbon black, nigrosine pigments, carmine 6B1 phthalocyanine blue, benzidine yellow, phthalocyanine green, etc., and charge control agents such as fatty acids and naphthenic acids are added to the extent that they do not adversely affect toner granulation and fixation. It can contain metal salts, metal-containing dyes, sulfonates, etc. After charging by a normal electrophotographic method using the electrophotographic original plate of the present invention, a xenon lamp, a halogen lamp, a tungsten lamp,
Alternatively, in addition to obtaining a toner image by reflective exposure using a fluorescent lamp as a light source, semiconductor laser, Ar+ or He-N
A toner image can be obtained by exposure to a laser beam such as e.g., or by contact exposure through a transparent positive 7 ilm.

Further, after exposure, charging can be performed to obtain a toner image using a photoconductive memory. After obtaining a toner image by such a method, the non-image area (the area to which toner does not adhere) is fixed using a hot plate, a hot roller, a hot wire, etc., and a gamma alkali aqueous solution such as sodium silicate, sodium phosphate, etc. When immersed in a solution containing an organic solvent such as benzyl alcohol or ethylene glycol monobutyl ether, or a surfactant, the non-image area is dissolved and removed, leaving only the toner-attached area on the support surface, resulting in a good printing plate. Obtainable.

In the fixing process, the recording layer may be burned if necessary. Further, the printing plate of the present invention may contain a quinonediazide compound (for example, cm naphthoquinonediazide) or a diazo compound for the purpose of increasing the dissolution of the recording layer by full-surface exposure after toner image formation.

Furthermore, when the printing plate of the present invention is used, two types of printing plates, positive-positive and negative-positive, can be obtained using one type of liquid developer by utilizing positive and negative polar surrounding charging.

This method utilizes reversal development using a liquid development method, and is an extremely useful plate-making method industrially. The application of the present invention is to obtain a printing plate (lithography or letterpress) with high resolution and high durability (printing capacity of about 100,000 sheets) by a small amount of light (number + Erg / 0f1L) by corrosion after toner image formation. In addition, (1) a contact film for printing plates, a micro film, etc. can be formed using a transparent support.

(2) There are industrial advantages such as the ability to create printed circuits using conductive substrates. EXAMPLES The present invention will be specifically explained below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 Japanese Patent Publication No. 40-2780, Japanese Patent Publication No. 48-76925,
ε-type copper phthalocyanine pigment produced by the method described in Publication No. 49-59136
1 part by weight Compound Example 26 parts by weight Ethylene glycol monoethyl 24 parts by weight
A rotary coater was used to coat a grained and anodized aluminum plate with a thickness of 0μ to a dry weight of approximately 0.
The coating machine was rotated at 500 revolutions per minute so that the coating color was 5 to 100 d/min.

This electrophotographic printing original plate was heated and dried for about 3 hours in a dryer heated to 60° C. to prepare a sample. The electrostatic characteristics of the electrophotographic printing original plate thus prepared were measured using an electrostatic paver analyzer (Ele) manufactured by Kawaguchi Electric Co., Ltd.
ctrOstalicPaperAnalyzer)S
Measured using P-428.

At this time, the measurement was carried out in the dark with +6.0K corona discharge at 10
After being charged positively for 2 seconds, the sample surface was exposed to 2854 tungsten light at an illuminance of 35 lux. As a result, it was found that the saturation charging potential was 300 V1, and the half-reducing exposure amount was 16 lux·sec. Next, this sample was subjected to a +6.0 K corona discharge in a dark place so that the surface potential became +200, and a positive image was exposed to tungsten light (80 lux seconds).
When liquid development was carried out in a stainless steel vat using MRP toner manufactured by Rikoichi Co., Ltd. using (manufactured by Etsuo Standard Oil Co., Ltd.) as a carrier liquid, a very clear positive-positive toner image was obtained. could be obtained on the original plate sample for electrophotographic printing.

This electrophotographic printing original plate was immersed in an alkaline aqueous solution consisting of sodium silicate and caustic soda to remove the photoconductive layer in non-image areas (portions to which no toner was attached).

As a result, a lithographic printing plate with a clear image and excellent resolution and printing durability was created. On the other hand, the resin was t-butylphenol-formaldehyde resin (comparative compound example 1 described later).
A comparative sample was prepared in the same manner as the sample except that a toner image was formed using the toner image forming method described above. When a toner image was obtained according to the toner image forming method described above, the toner image ran and smeared, and the image became unclear. Further, the photoconductive layer could not be removed using an alkaline aqueous solution having the same composition as in Example 1. In the comparative sample, it is thought that the toner image becomes unclear because the t-butylphenol-formaldehyde resin, which is the binder, dissolves, swells, or softens in the carrier liquid of the liquid developer.

Example 2 Two types of electrophotographic printing original plates were prepared by the method of Example 1 using the various phenolic resins shown in the compound examples above.

In addition, two types of comparative samples using the comparative resin described later were prepared in the same manner as in Example 1, and a comparative test was conducted.

Table 1 summarizes the toner images of these samples and comparative electrophotographic printing plates and their solubility in the alkali aqueous solution.

Comparison compound example However, M represents the average molecular weight.

From the results shown in Table 1, it can be seen that the electrophotographic original plate sample of the present invention dissolves easily in an aqueous alkaline solution and has a clear toner mound, which is significantly superior to the comparative sample.

This is considered to be because the novolak type phenolic resin used in the electrophotographic printing original plate of the present invention does not dissolve, swell, or soften in the carrier liquid of the liquid developer. Example 3 In Example 1, when the negative image was illuminated by corona discharge at -6.0 K in a dark place and reversal development was performed in the same manner as in Example 1, except that a stainless steel mesh counter electrode was used, a clear negative image was obtained. - A positive toner image could be obtained on the electrophotographic original plate sample using Compound Example 2.

Furthermore, in the same manner as in Example 1, by removing the photoconductive layer in the area to which toner was not attached on the electrophotographic printing plate using an alkaline aqueous solution, a lithographic printing plate with a clear image and excellent resolution and printing durability could be created. .

Comparative Example 1 A comparative sample was prepared in the same manner as in Example 1 except that the resin was a styrene-maleic anhydride copolymer (Comparative Compound Example 4, manufactured by Monsanto Co., Ltd.) and the solvent was methyl ethyl ketone. Similarly, considering the electrostatic characteristics, in the case of positive charging, the saturation charging potential is 150, and the half-life exposure amount is approximately 2.
It turned out to be 00 lux-seconds.

Further, in the case of negative charging, when corona discharge was performed at -60K, the saturation charging potential was 100, and the sensitivity was hardly exhibited. These results show that the printing plate of the present invention is significantly superior in charge acceptance and sensitivity to a printing plate using styrene-maleic anhydride copolymer as the binder. Preferred embodiments of the present invention are as follows.

(1) The printing original plate according to claim 1, wherein the hydrophilic injecting functional group is a hydroxy group, an amino group, a carboxylic group, or a salt thereof.The sulfo group or a salt thereof is a salt thereof.

(2) The printing original plate according to claim 1, wherein the printing original plate is for both positive and negative charging.

(3) The printing original plate according to claim 1, wherein the printing original plate is a transfer body.

(4) The method for forming a printing plate according to claim 2, wherein the hydrophilic functional group is a hydroxy group, an amino group, a carboxy group or a salt thereof, a sulfo group or a salt of a group thereof.

(5) The printing plate according to claim 2, wherein the printing plate forming method uses the printing original plate to form a negative-positive or positive-positive printing plate with one type of liquid developer. Formation method.

(6) The method for forming a printing plate according to claim 2, which includes a transfer step when forming the toner image on the recording layer.

Claims (1)

[Scope of Claims] 1. A toner image is formed on a recording layer mainly composed of a phenolic resin having a structural unit represented by the following general formula [I] provided on a hydrophilic substrate by a liquid development method, and an alkaline solution A method for forming a printing plate, comprising dissolving and removing a recording layer in an area having no toner image. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [In the formula, R_1 is a phenyl group or a frifuryl group; R
_2, R_3 and R_4 are hydrogen atoms, hydroxy groups,
Carboxy group or salt thereof, each having 1 to 1 carbon atoms
20 alkyl groups. However, when at least one of R_2, R_3 and R_4 represents a group having 4 or more carbon atoms, at least one of R_2, R_3 and R_4 represents a hydroxy group, a carboxy group or a salt thereof. ]