JPS5936259B2 - 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 of forming a printing plate using this printing original plate.

More specifically, it is a printing original plate having a recording layer mainly composed of a specific phenolic resin, and a toner image is formed on this recording layer by a liquid development method, or a toner image is formed on the recording layer through a transfer process. The invention relates to a method of forming a printing plate by etching after forming a toner image on the plate. Conventional printing plates include, for example, silver halide photosensitive materials, photosensitive resins, photoconductors in which inorganic photoconductive materials such as zinc oxide are dispersed in resin, and photoconductors in which organic photoconductive materials are mixed with resin. Are known.

However, printing plates made based on diffusion transfer development of silver halide photosensitive materials have the drawbacks of high cost per sheet and poor printing durability.

In addition, printing original plates using photosensitive resins have significantly lower sensitivity than photoconductive photoreceptors or silver halide photosensitive materials used in electrophotography, and require a strong light source and long exposure, so-called. It has drawbacks such as not being able to perform direct plate making.

Furthermore, a method in which the electrophotographic photosensitive plate is responsible for photosensitivity and the photosensitive printing original plate is responsible for printing durability or printing suitability, that is, a method that combines both, is described in JP-A-50-1801 and JP-A-51-143408. 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 printing plates using electrophotography include:
A zinc oxide-resin dispersion base plate for offset printing is known, which is described in Japanese Patent Publication No. 47-47610, Japanese Patent Publication No. 48-40002, Japanese Patent Publication No. 48-18325, Japanese Patent Publication No. 51-15766, Japanese Patent Publication No. 51-25761, etc. is used after electrophotographic toner image formation, after being wetted with a desensitizing solution (for example, a ferrocyan salt or an acidic aqueous solution containing a ferrocyan salt) to render the non-image areas fat-free.

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 even if the composition is made suitable for desensitization, the electrostatic properties are poor. There are drawbacks such as deterioration and deterioration of image quality. In addition, special public service Shou 37-17162, special public official Sho 3877
58, Japanese Patent Publication No. 46-39405, Japanese Patent Publication No. 52-2437
In the organic photoconductor-resin printing original plate described in et al.
For example, a photoconductor is used in which a photoconductive insulating layer of oxazole or oxydiazole bound with a styrene-maleic anhydride copolymer is provided on a grained aluminum plate. After forming a toner image using the method, 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 viewpoints of cost, safety, pollution, and occupational health. 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 properties change easily due to changes in humidity, and has poor storage stability due to poor charge retention. It has drawbacks such as:

Although the above publication also describes phenolic resins, it mainly describes styrene-maleic anhydride copolymer as a binder, and describes the type, properties, and individual structures of the phenolic resins used as binders. is not listed. 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, halogenated hydrocarbons, polymethylsiloxane, etc., which have electrical resistances as low as Development is often observed as deterioration or blurring of the image.

It is known that such development not only causes deterioration of the developer, but also poses a significant problem in obtaining clear, high-resolution toner images. SUMMARY OF THE INVENTION 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.

Still another object is to provide a printing original plate having excellent sensitivity, charge retention, moisture resistance, and electrostatic properties.

Still another object is to provide a printing original plate that can be charged with both positive and negative polarities and can be used for both 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 can be easily dissolved in an alkaline aqueous solution. The above purpose is to use a printing original plate having a recording layer on a hydrophilic substrate for obtaining a toner image mainly composed of a phenolic resin having repeating units represented by the following general formula, and to form a recording layer of this printing original plate. This is achieved by using a printing plate forming method in which a toner image is formed on the printing plate by a liquid development method, the toner image is fixed by heating if necessary, and the recording layer in the area where the toner image does not exist is dissolved and removed using an alkaline solution. .

In the general formula, R1 and R2 are hydrogen atoms or lower alkyl groups, R3, R4 and R5 are hydrogen atoms, halogen atoms, hydroxyl groups, nitro groups, amino groups, carboxyl groups or salts thereof, sulfonic acid groups or salts thereof, carbon Number of atoms: 1
-20 chain hydrocarbon group or a hydrocarbon ring group having 4 to 14 carbon atoms.

However, at least one of the above substituents R3, R4 and R5
is a substituent having 4 or more carbon atoms, R3, R
At least one of 4 and R5 is a hydrophilic functional group, or at least one of R3, R4 and R5 has a hydrophilic functional group. That is, by configuring the present invention in this manner, the following effects can be achieved.

For example, a liquid developer is used to turn an electrostatic latent image formed on a printing plate into a visible image. For this reason, a toner image with high resolution can be obtained, and since the recording layer uses a phenolic resin as a main component that has a specific structure that is not attacked by liquid developer, the image may be distorted or
This has the effect that a printing plate with excellent printing durability and high resolution can be obtained without the recording layer being softened or deformed or the developer being deteriorated. Furthermore, 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 have a positive or negative polarity depending on the characteristics of the specific phenolic resin used. Either type of charging is possible, and it is possible to form a printing plate for both positive-positive and negative-positive printing with one type of developer. Furthermore, since the resin of the present invention is alkali-soluble, 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 original plate of the present invention, this electrostatic charge image is made into a toner image by liquid development, and this is converted into an alkaline image. Although the process includes plate making by etching with a liquid, the specific phenolic resin of the present invention has excellent charge retention properties, 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. .

Next, the phenolic resin used as the main component of the binder resin of the printing plate of the present invention is a modified phenolic resin having the structural unit shown in the above general formula and other phenolic resin monomers. Also included are cocondensates modified with, for example, epoxy or polyvinyl alcohol.

Furthermore, the average molecular weight of the phenolic resin used in the present invention is 2.
40-20000, preferably 350-6000
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, and dioxane; and esters such as butyl acetate and ethyl acetate. Phenolic resins that are soluble in solvents such as the following are desirable. Examples of compounds that can be effectively used in the present invention include the following.

However, T. ．． 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 photoconductive organic pigments can be used.

For example, inorganic photoconductors include zinc oxide, cadmium sulfide, titanium oxide, selenium, cadmium selenide, zinc selenide or lead oxide, and organic photoconductors include substituted vinyloxazoles, such as 2-vinyl-4- (2
'-chlorophenyl)-5-(4''-diethylaminophenyl)-oxazole or triphenylamine derivatives, higher condensed aromatic compounds such as anthracene, benzo-fused heterocycles, pyrazoline or imidazole derivatives, such as 1-phenyl-3 -(p-diethylaminostyryl)-5-(p-diethylaminophenino(c)
- pyrazolines or triazoles, oxadia J zole derivatives such as 2,5-bis-(4''-diethylaminophenyl)-1,2,3-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-fluorenone, 2,4
, 5,7-tetranitrofluorenone, polyarylalkane such as triarylmethaneleuco dye or squaric acid derivative dye, 2,4,8-trinitrothioxanthone, and the like. Next, among the photoconductive organic pigments used in the present invention, phthalocyanine pigments include:
1021, Special Publication No. 46-42511, Special Publication No. 46-42
512, Special Publication No. 48-163, Special Publication No. 49-17535
, a photoconductive phthalocyanine pigment described in Japanese Patent Publication No. 50-5059 and Japanese Patent Application Laid-open No. 50-38543, etc.,
It is represented by the general formula (C8H4N2)4Rn, and R is a hydrogen atom, eutherium, sodium, potassium, copper, silver, beryllium, magnesium, calcium, zinc, cadmium, barium, mercury, aluminum, potassium, indium, lanthanum, neodymium, samarium , europium, cadmium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, titanium, tin, hafnium, lead, thorium, vanadium, antimony, chromium, molybdenum, uranium, manganese, iron, cobalt, nickel, rhodium, palladium, They are osmium and platinum, and n is O~2.

Among these, alpha (a), beta (β,
Comma (γ), pi (π), ex (x) and epsilon (ε) type metal-free phthalocyanines or metal phthalocyanines such as copper, cobalt, lead and zinc are preferred.

Examples of azo pigments include photoconductive azo pigments described in JP-A-51-90827, JP-A-52-55643, etc., including monoazo pigments represented by the following general formula 1 and cis-azo pigments represented by the following general formula. is used in the present invention.

In the formula, Z is -NO2, -CNl-C Brl-H1-N
Represents an atom or group such as (C2H5)2.

In the formula, A is or R2 where R1 and R2 are lower alkyl groups.

X and Y are -NO2, -CNl-H1-CH3, -0C
H3, -0C2H5, -0H. -Ct, -Br, Yo {C
, H5) represents an atom or group such as 2. Among the compounds represented by the above general formula, Diane Blue, which is a type of disazo pigment, is particularly preferred.

As the quinacridone pigment, for example, Japanese Patent Application Laid-Open No. 493033
The quinatalydone pigment described in No. 2 and represented by the following general formula, which may have a substituent if necessary, is used in the present invention. General formula Among the pigments represented by the above general formula, especially beta (β and gamma one (γ)) linear trans-quinacridone, unsubstituted trans-quinacridone and trans-quinacridone substituted with a methyl group or a chlorine atom are used. Quinacridones are preferred.

As a bisbenzimidazole pigment, for example, JP-A-4
A trans type compound represented by the following general formula 1 and a cis type pigment represented by the following general formula, which are bisbenzimidazole pigments described in No. 7-18543, are used in the present invention.

In the formula, each of R1 and R2 is an optionally substituted alkyl group,
Represents 1 to 4 substituents selected from an optionally substituted aryl group, halogen atom, nitro group and amino group,
When there are multiple substituents, they may be the same or different.

Furthermore, the substituents R1 and R2 may form various rings together with the benzene nucleus. In addition to these, pigments having a heterocycle produced by the reaction of 1,4,5,8-tetracarboxylic naphthalene and a heterocyclic diamine can also be effectively used in the present invention; examples of indigo pigments include Trans-indigo pigments represented by the following general formula 1 and cis-indigo pigments represented by the following general formula described in JP-A-47-30331 are used in the present invention.

In the formula, R is an alkyl group, an aryl group, an amino group, or a halogen atom, and X and Y are groups or atoms selected from -NH-, 0-, -S-Se, and -Te=. ,
The substituents may be the same.

Among these, unsubstituted trans indigo in which X and Y are an NH group or an S atom is particularly preferred. As a quinone pigment,
For example, polycyclic quinone pigments described in JP-A-47-18544 are used in the present invention, preferably andanthrone, pyranthrone, dibenzpyrenequinone, pyrenequinone, 3,4,9,10-dibenzpyrenequinone, bromine andanthrone, brominated dibenzpyrenequinone, brominated pyranthrone, anthraquinone thiazole, flavanthrone, etc. are used.

As perylene pigments, for example, JP-A-47-30330
Pigments represented by the following general formula 1 and the following general formula described in US Pat. No. 3,871,882 are used in the present invention.

In the formula, Q is an alkyl group, an allyl group, an aralkyl group, an alkoxy group, a heterocyclic substituent, or a halogen atom.

In the formula, Z 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, X represents an iodine atom or a bromine atom, Q represents a quinoline ring, and n represents 0, 1, 2, or 3.

As a cyanine pigment, for example, JP-A-47-37544
Those represented by the following general formula described in are used in the present invention.

In the formula, R is a methyl group, an ethyl group, or an allyl group,
It is an ethyl group.

As pyrylium salt pigments, for example, Japanese Patent Publication No. 462251
9, those represented by the following general formula described in Japanese Patent Publication No. 46-22518 etc. are used in the present invention. R here? R R9 Blue Wh each hydrogen atom; typically 1 carbon atom
aliphatic or aromatic groups having ~15, such as methyl, ethyl, propyl-isopropyl-butyl-t-
Butyl, amyl, isoamyl, hexyl, octyl, nonyl, dotesyl, styryl, methoxystyryl, diethoxystyryl, dimethylaminostyryl, 1-butyl-4-P-dimethylaminophenyl-1,3-phthadienyl, β- Alkyl groups such as ethyl-4-dimethylaminostyryl: methoxy, ethoxy, propoxy,
Alkoxy groups such as butoxy, amyloxy, hexoxy, octoxy: phenyl, 4-diphenyl, alkylphenyls (4-ethylphenyl, 4-propylphenyl, etc.), alkoxyphenyls (4-ethoxyphenyl, 4-methoxyphenyl, etc.) oxyphenyl, 4-amyloxyphenyl, 2-hexoxyphenyl, 2-methoxyphenyl, 3,4-dimethoxyphenyl, etc.), β-hydroxyalkoxyphenyl (2-hydroxyethoxyphenyl, etc.), oxyphenylene, 3-hydroxyethoxyphenyl, etc.)
, 4-hydroxyphenyl, halophenyl (2,4
-dichlorophenyl, 3,4-dibromophenyl, 4-
chlorophenyl, 2,4-dichlorophenyl, etc.), azidophenyl, nitrophenyl, aminophenyl (4-
(diethylaminophenyl, 4-dimethylaminophenyl, etc.) and naphthyl; vinyl, etc., where X is a sulfur atom, oxygen atom or selenium atom, and Z is an anionic functional group (perchlorate, fluoroporate, iodate, (including chloride, bromide, sulfate, sulfonate, periotate, P-toluenesulfonate, etc.).

Furthermore, the pair Ra and Rb and the pair Rd and Re together represent the atomic groups necessary to complete the closed aryl ring to form the hyrylium nucleus.

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

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

Examples of dye sensitizers include malachite green, crystal violet, methyl violet, night blue, Victoria blue, Rhodamine B1 Capripur,
Methylene chloride, fuchsin, loin bengal, polymethine pigment, thioxandene pigment, etc. are used. Examples of chemical sensitizers include P-benzoquinone, 2,5-dichlorobenzoquinone, benzophenonetetracarboxylic acid dianhydride, 2,6-dichlorobenzoquinone, chloranil, naphthoquinone mono(1,4), 2,3 -dichlornaphthoquinone-(1,4), anthraquinone, 2-
Methylanthraquinone, 1,4-dimethyl-anthraquinone, 1-chloroanthraquinone, anthraquinone-2
-carboxylic acid, 1,5-cycloanthraquinone, 1-
Chlor-4-nitroanthraquinone, phenanthrene-quinone, acenaphthenequinone, pyrantrenequinone, chrysene-quinone, thionaphthene-quinone, anthraquinone-1,8-disulfonic acid and anthraquinone-2-
Quinones such as aldehydes; triphthaloylbenzene, e.g. promal, 4-nitrobenzaldehyde, 2
, 6-dichlorobenzaldehyde, 2-ethoxy-1-
Naphthaldehyde, anthracene-9-aldehyde, pyrene-3-aldehyde oxindole-3-aldehyde, pyridine-2,6-dialdehyde, biphenyl-4
-Aldehydes such as aldehydes: e.g. 4-chloro-
Organic phosphonic acid such as 3-nitrobenzene-phosphonic acid; nitrophenols such as 4-nitrophenol; picric acid such as acetic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, anhydride Tetrachlorophthalic acid, pyrene-3,4,9,
10-tetracarboxylic acid and chrysene-2,3,8,9
Anhydrous acids such as monotetracarboxylic anhydride: Periodic Table 1B
Metal halides of Group 1 and metalloids, such as aluminum chloride, zinc chloride, ferric chloride, tin tetrachloride (tin chloride), arsenic trichloride, stannous chloride, antimony pentachloride, magnesium chloride, Magnesium bromide, calcium bromide, calcium iodide, strontium bromide, chromium bromide, manganese chloride, cobaltous chloride, cobaltous chloride, cupric bromide, cerium chloride, thorium chloride, triiodide Arsenic: boron halide compounds such as boron trifluoride and boron trichloride; e.g. acetophenone, benzophenone, 2-acetyl-naphthalene, benzyl, benzoyl, 5-benzoylacenaphthene, 9-
Acetyl-anthracene, 9-benzoyl-anthracene, 4-(4-dimethylaminocinnamoyl)-1-
Acetylbenzene, acetoacetic acid anilide, indanedione-(1,3), (1-3-diketo-
hydroquinone), acenaphthenequinone dichloride,
Included are ketones such as anisyl, 2,2-pyridyl and furyl.

Still other Lewis acids are mineral acids such as hydrogen halides, sulfuric acid and phosphoric acid; for example acetic acid and its substitution products, monochloroacetic acid, cycloacetic acid, trichloroacetic acid, oleicarboxylic acid phenyl acetic acid and 6-methyl-coumarinyl acetic acid. Organic carboxylic acids such as (4); maleic acid, cinnamic acid, benzoic acid, 1-(4-diethylaminobenzoyl)-benzene-2-carboxylic acid, phthalic acid, tetrachlorophthalic acid, α-β-dibromo -β-formyl-acrylic acid (mucomonobromic acid), dibromo-maleic acid, 2-
Brobenzoic acid, gallic acid, 3-nitro-2-hydroxyl-1-benzoic acid, 2-nitrophenoxyacetic acid,
2-nitro-benzoic acid, 3-nitro-benzoic acid, 4-nitro-benzoic acid, 3-nitro-4-ethoxy-benzoic acid,
2-chloro-4-nitro-1-benzoic acid, 3-nitro-
4-Methoxy-benzoic acid, 4-nitro-1-methyl-benzoic acid, 2-chloro-5-nitro-1-benzoic acid, 3-
Chlor-6-nitro-1 monobenzoic acid, 4-chloro-3-
Nitro-1-benzoic acid, 5-chloro-3-nitro-2-
Hydroxy-benzoic acid, 4-chloro-2-hydroxy-benzoic acid, 2,4-sinitro-benzoic acid, 2-
Bromo-5 nitro-benzoic acid, 4-chlorophenylacetic acid, 2-chloro-cinnamic acid, 2-cyano-cinnamic acid, 2,4
-dichloro-benzoic acid, 3,5-dinitrobenzoic acid, 3
, 5-cinitrosalicylic acid, malonic acid, mucic acid, acetosalicylic acid, butane-tetracarboxylic acid, citric acid,
Cyanomonoacetic acid, cyclohexane-dicarboxylic acid, cyclohexane-monocarboxylic acid, 9,10-dichloro-stearic acid, fumaric acid, itaconic acid, levulinic acid, malic acid, succinic acid, α-bromo-stearic acid, citraconic acid, dibromo - succinic acid, pyrene-2,3,7,8-tetracarboxylic acid, atracarboxylic 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-hydroxybenzene-5-sulfonic acid, 6 -nitro-4-methyl-1-hydroxybenzene-2-sulfonic acid, 4-
Chlor-1-hydroxybenzene-3-sulfonic acid, 2-chloro-3-nitro-1-methyl-benzene-5
-sulfonic acid and organic sulfonic acids such as 2-chloro-1-methyl-benzene-4-sulfonic acid.

The phenolic resin of the printing 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 butylcellulose, polyvinyl alcohol, gelatin. , casein, or a phenolic resin that does not belong to the present invention.

However, it is preferable that the constituent units of the phenolic resin of the present invention are 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.

Plasticizers are effective for making the recording layer provided on the support have a desired texture, such as (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl). Phthalate, synchrohexyl phthalate, ditridecyl phthalate, butylbenzyl phthalate, diisodecyl phthalate, phthalate esters such as diaryl phthalate, dimethyl glycol phthalate, ethylputaryl ethyl glycolate, methylptaryl ethyl glycolate, butyl phthalylbutyl glycolate , glycol esters such as triethylene glycol dicaprylate, phosphoric esters such as tricresyl phosphate and triphenyl phosphate, diisobutyl adipate, dioctyl adipate,
Fatty acid dibasic acid esters such as dimethyl sebacate, dibutyl sebacate, dioctyl azelate, and dibutyl maleate, polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate, and the like are effective. The plasticizer can be contained within a range that does not deteriorate the electrostatic properties or alkali solubility of the recording layer.

Printing plate substrates that are effective in the present invention include offset printing base paper, aluminum plates, zinc plates, bimetallic plates such as copper-aluminum cum plates, copper-stainless steel plates, chrome-copper plates, etc.
Or chrome-copper-aluminum plate, chrome-copper-iron plate,
An electrically insulating, low-resistance or conductive substrate with hydrophilic properties such as a tri-metal plate such as a chromium-copper-stainless steel plate is used, but a conductive or low-resistance surrounding substrate with a hydrophilic surface is preferably used. It will be done.

In addition, especially in the case of a support having an aluminum surface, surface treatments such as graining treatment, immersion treatment in a hydrochloric acid solution such as sodium silicate, potassium fluorozirconate, or phosphate, or anodizing treatment may be performed. It is preferable that

In addition, as described in U.S. Pat.
As described in the above publication, an aluminum plate which has been anodized and then immersed in an aqueous solution of an alkali metal silicate is also suitably used. The above-mentioned anodizing treatment can be carried out using, for example, an electrolytic solution containing an aqueous or non-aqueous solution of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, or boric acid, or an organic acid such as oxalic acid or 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. 365866
Silicate electrodeposition as described in No. 2 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 In addition, in the present invention, an alkaline intermediate material such as casein, polyvinyl alcohol, ethyl cellulose, phenolic resin, styrene-maleic anhydride copolymer, polyacrylic acid, etc. is optionally provided between the hydrophilic/surrounding substrate and the recording layer. A layer may be provided for the purpose of improving the adhesion between the support and the recording layer or the electrostatic properties of the recording layer. Further, in the present invention, an overcoat layer that dissolves when the recording layer is removed may be provided on the recording layer, if necessary, for the purpose of improving the electrostatic properties of the recording layer, the development properties during toner development, or the image properties.

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,
Polymer particles (e.g. particles of polymethyl methacrylate, polystyrene, phenolic resins, etc.) and U.S. Pat. No. 2,701,245, U.S. Pat. No. 2,992,101
This includes the matting agents described in the specification.

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, gum arabic, glue, gelatin, casein, celluloses (such as viscose, methylcellulose,
ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carpoxy methyl cellulose, etc.), starches (e.g. soluble starch, modified starch, etc.), polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyacrylamide, polyvinyl methyl ether, epoxy resin , phenolic resin (novolac type phenolic resin is particularly preferred), polyamide, polyvinyl butyral, and the like. 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 photosensitivity, the phenolic resin of the present invention is suitably dissolved in the above-mentioned organic solvent, and then the phenolic resin of the present invention is coated on the above-mentioned hydrophilic substrate to a thickness of 1 to 50 μm. (preferably 1~
15μ thick) and dry it.

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, halogenated hydrocarbons,
The photoconductor may be appropriately dissolved in an organic solvent such as toluene, tetrahydrofuran, or ethyl acetate, or if the photoconductor is not dissolved, it may be dispersed substantially uniformly using a homogenizer or an ultrasonic disperser, and then applied onto the hydrophilic substrate. 1 to 50
It is prepared by coating and drying to a thickness of μ, preferably 1 to 15 μ. 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 phthalocyanine pigment, such as an α, β, γ, π, ε or A recording layer containing dispersed proportions of
For example, a printing original plate is prepared by coating a grained hydrophilic aluminum, zinc or copper-aluminum plate to a dry film thickness of 1 to 15 μm.

This printing 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 corona discharge or electric shock from needle electrodes and preventing damage to the recording layer, and is also capable of being charged both positively and negatively. be able to.

Various coating methods are possible, including tab coating, air knife coating, bead coating, curtain coating, and extrusion coating using a hopper as shown in US Pat. No. 2,681,294. The image-limiting method used in the present invention includes a dry method using a developer in which both the toner and the carrier are solid, a wet method when the toner or carrier is a liquid, and a wet method when the toner or carrier is a liquid, and whether the toner is solid or 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 a high-resolution image.

The toner used in the present invention is preferably hydrophobic and ink receptive, and examples thereof include polystyrene resin, polyester resin (amino group-containing acrylic ester, long-chain acrylic ester, etc.), acrylic resin (phenol These include resins with hydroxyl groups or sulfon groups), epoxy resins, vegetable oil-modified alkyds, cyclized rubbers, asphalt, vinyl chloride, and other polymeric substances.

In addition, colorants such as carpon black, nigrosine pigments, carmine 6B1 phthalocyanine blue, benzidine yellow, phthalocyanine green, etc., and charge control agents such as fatty acids and naphthenic acids may be added to the extent that they do not adversely affect the granulation and fixing properties of the toner. It can contain metal salts, metal-containing dyes, sulfonates, and the like. 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 film.

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, it is heated and fixed using a hot plate, a heated roller, a hot wire, etc., and the non-image areas (areas to which toner does not adhere) are coated with an aqueous alkaline solution such as sodium silicate or sodium phosphate, or further benzyl alcohol. When immersed in a solution containing an organic solvent such as 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. I can do it.

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, o-naphthoquinonediazide) or a diazo compound for the purpose of increasing the solubility of the recording layer by exposing the entire surface to light after toner image formation. Furthermore, when the printing plate of the present invention is used, positive-positive and negative-positive two can be created using one type of liquid developer using positive and negative polarity charging.
Various types of printing plates are obtained.

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 approximately 100,000 sheets) by a small amount of light (number + Erg/0rn) by corrosion after toner image formation. other(
1) Contact film for printing plates using a transparent support,
Alternatively, a microfilm or the like can be formed.

(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 1 part by weight of ε-type copper phthalocyanine pigment produced by the method described in Japanese Patent Publications No. 40-2780, No. 48-76925, and No. 49-59136 Compound Example 26 parts by weight Ethylene glycol 24 parts by weight Mono Ethyl ether The composition according to the above weight ratio was dispersed for 5 minutes at room temperature using an ultrasonic disperser, and the weight after drying was applied to a grained and anodized aluminum plate of about 100μ thickness using a rotary coater. The coating process was carried out by rotating the coating machine at 500 revolutions per minute so that the coating amount was approximately 0.4 mg/d.

This electrophotographic printing original plate was heated and dried in a dryer heated to 60° C. for about 3 hours to prepare a sample. The electrostatic properties of the electrophotographic printing original plate thus prepared were measured using an Electrostatic Paper Analyzer 1 (EIect) manufactured by Kawaguchi Electric Co., Ltd.
rOstaticPaperAnalyzer)SP-
Measured using 428.

At this time, the measurement was carried out in the dark with +6.0K corona discharge at 10
After being charged positively for a second, the sample surface was exposed to 2854 tungsten beams at an illuminance of 35 lux. As a result, it was found that the saturation charging potential was 500 V, and the half-reduction exposure was 20 lux·sec. Next, a +6.0 KV corona discharge was applied to this sample in a dark place so that the surface potential became +200 V, and a positive image was exposed with tungsten light (8
0 lux/sec), and then liquid development was performed in a stainless steel vat using MRP toner manufactured by Rikoichi Co., Ltd., with the isoparaffinic solvent Isopar-H (manufactured by Etsuo Standard Oil Co., Ltd.) as the carrier liquid. A very clear positive-positive toner image could be obtained on the sample electrophotographic printing original plate.

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, 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 Three 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.

The toner images of these samples and comparative sample electrophotographic printing original plates and their solubility in the alkaline aqueous solution are summarized in Table 1.

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

From the results shown in Table 1, it can be seen that the electrophotographic printing original plate of the present invention is easily dissolved in an alkaline aqueous solution and the toner image is clear, 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, a negative image was exposed to light by corona discharge of -6.0 KV 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, and a clear negative image was obtained. A positive toner image could be obtained on the sample electrophotographic printing original plate using Compound Example 2.

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

Example 4 When the spectral sensitivity of the sample electrophotographic printing original plate described in Example 1 was measured, the results shown in FIG. 1 were obtained.

Spectral sensitivity was evaluated using the reciprocal of the half-decreased exposure. This result shows that this printing original plate is suitable for He-Ne lasers or semiconductor lasers. Comparative example 1 Example 1
A comparative sample was prepared in the same manner as above except that the resin was a styrene-maleic anhydride copolymer (Comparative Compound Example 4, manufactured by Monsanto) and the solvent was methyl ethyl ketone.
When the electrostatic characteristics were examined in the same manner as in Example 1, it was found that in the case of positive charging, the saturation charging potential was 150 and the half-life exposure was approximately 200 lux·sec.

Further, in the case of negative charge, when a corona discharge of 6.0 KV was performed, the saturation charging potential showed almost no sensitivity of 100V1. 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. Example 5 Zinc oxide (manufactured by Sakai Chemical Co., Ltd.) 1 part by weight Compound Example 1
1 part by weight Methyl ethyl ketone 1 part by weight Rose Bengal 0.01 part by weight A sample was prepared in the same manner as in Example 1, except that the composition with the above weight ratio was adjusted to a film thickness of 5 μm, and the electrostatic properties were examined. As a result, in the case of negative charging, the saturation charging potential was -270, and the half-reduction exposure amount was 72 lux·sec.

Further, in the case of positive charging, the saturation charging potential was +200 V, and the half-reduction exposure amount was 140 lux·sec.

From this, it can be seen that the original plate for electrophotographic printing using the resin of the present invention has both positive and negative chargeability, and is suitable for negative-positive or positive-positive plate making. On the other hand, a comparative sample was prepared in the same manner as the sample except that Comparative Compound Example 1 was used as the resin, and when liquid development was performed to obtain a toner image, the recording layer of the comparative sample was eroded by the liquid developer and the substrate was removed. It was found that it was easy to separate, and therefore it was impossible to form a printing plate with a clear image that would have a long printing life. ? α-1 type copper phthalocyanine 1 part by weight 2,4,7-trinitro 3 parts by weight -9-Fluorenone Compound Example 220 parts Methyl ethyl ketone 40 parts by weight Except for using a composition with the above weight ratio so that the film thickness was 5μ A sample was prepared in the same manner as in Example 1, and the electrostatic properties were examined. When negatively charged, the saturation charging potential was -450 V (5), and the half-reduction exposure amount was 18 lux·sec.

In the case of positive charging, the saturation charging potential was +460 V and the half-reduction exposure amount was 20 lux·sec. From this, the electrophotographic printing original plate using the resin of the present invention has both static and negative charging properties,
It can be seen that it is suitable for both negative-positive and solid-bodies plate making.

Example 7 An original plate for electrophotographic printing in which an ε-1 type copper phthalocyanine pigment was dispersed was prepared in the same manner as in Example 1 using a resin obtained by mixing Compound Example 2 and Comparative Compound Example 2 as a binder, and a toner image and The alkali solubility was investigated.

As a result, as shown in Table 2, the sharpness of the toner image depends on the resin of Compound Example 2, which is dissolved in the carrier liquid of the liquid developer.
The effect of adding the resin used in the printing original plate of the present invention on the resin that swells or softens was observed.

[Brief explanation of the drawing]

FIG. 1 shows the spectral sensitivity of the phthalocyanine-resin recording layer of Example 1, and the spectral sensitivity is expressed as a relative sensitivity calculated from the reciprocal of the half-death exposure.

Claims (1)

[Claims] 1. A toner image is formed by a liquid development method on a recording layer mainly composed of a phenolic resin having repeating units represented by the following general formula, which is provided on a hydrophilic substrate, and the toner image is formed by an alkaline solution. 1. A method for forming a printing plate, comprising dissolving and removing a recording layer in an area that does not have a recording layer. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_1 and R_2 are hydrogen atoms or lower alkyl groups, R_3, R_4 and R_5 are hydrogen atoms, halogen atoms, hydroxy groups, nitro groups, amino groups, carboxy groups or a salt thereof, a sulfo group or a salt thereof, an alkyl group having 1 to 20 carbon atoms, an alkoxy group, an alkyl ether group, an alkyl ketone group, an acyl group, or a benzene ring. However, when at least one of the substituents R_3, R_4 and R_5 is a substituent having 4 or more carbon atoms, R
At least one of _3, R_4 and R_5 is a hydrophilic functional group selected from a hydroxy group, an amino group, a carboxy group, a sulfo group, or a salt of these groups, or R_3, R
One of _4 and R_5 has the hydrophilic functional group. ]