JPS59121060A - Printing plate for electrophotographic photomechanical process - Google Patents

Abstract

PURPOSE:To obtain high printing resistance by using a specified compd. as an org. photoconductive compd. used for electrophotographic photomechanical process having a layer contg. the org. photoconductive compd. and an alkali- soluble resin on a conductive substrate. CONSTITUTION:An org. photoconductive compd. used in a printing plate for electrophotographic photomechanical process having a layer contg. the org. photoconductive compd. and an alkali-soluble resin on a conductive substrat is represented by the formula I in which R1, R2 are each H, halogen, cyano, 1-4C alkoxy, or 1-4C alkyl; Ar is formula II or III; R3 is 1-4C alkyl; R4 is H, halogen, or 1-4C alkyl or alkoxy, or dialkylamino; n is 1 or 2; R5, R6 are each H, 1-4C or benzyl, each may be substd. The photoconductive layer is formed in a 2-15mum thickness, and a suitable content of the photoconductive compd. in the photoconductive layer is 10-60wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel printing plate that can be made by electrophotography. More specifically, a new printing plate containing a specific photoconductive substance is charged and an electrostatic latent image obtained by subsequent imagewise exposure is developed with a toner and fixed to obtain a toner image, after which a non-image This invention relates to a printing plate that is made by dissolving and removing a photosensitive layer.

Conventionally, as planographic printing original plates, those using photosensitive resins and silver halide photosensitive materials are known.

However, although lithographic printing plates using photosensitive resin have high printing durability, they have low sensitivity and cannot be used in so-called direct plate making, requiring operations to create negatives or positives from originals using silver halide film or film. Therefore, there are disadvantages such as requiring large-scale equipment and requiring time for plate making.

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

As a printing plate for direct plate making using electrophotography, for example, Tokuko Sho 47-47610゜ Tokuko Sho/18=
-40002, Special Publication Showa/18-18325, Special Publication Showa 51
-15766 and Japanese Patent Publication No. 51-25761, printing plates containing a zinc oxide-resin dispersion system are known. After forming a toner image on this printing plate by electrophotography, it is treated with an acidic aqueous solution containing, for example, a ferrocyanate salt in order to make non-image areas hydrophilic. Printing plates made in this way have a printing durability of about 5,000 to 10,000 sheets due to the mechanical pressure applied during printing and the penetration of damp wood into the photosensitive layer and conductive layer. there were.

The purpose of the present invention is to
The objective is to provide a new printing plate that works effectively and has very high printing durability.

As a result of studying printing plates having layers made of various photoconductive compounds and alkali-soluble resins, the present inventors found that the above object can be achieved when a photoconductive compound represented by the following general formula is used. I discovered that.

That is, the present invention provides a printing plate for electrophotographic printing plates having a layer containing an organic photoconductive compound and an alkali-soluble resin on a conductive support, as the organic photoconductive compound,
In the electrophotographic printing stamp F, which is characterized by using a compound represented by the following general formula, R1+ R1 is hydrogen, halogen, cyano group, alkoxy group having 3-1 to 4 carbon atoms, or C1-4 alkoxy group. represents an alkyl group, R3 represents an alkyl group having 1 to 4 carbon atoms, R4 represents hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a dialkylamino group; l is 1 or 2, and when n is 2.

R4 may be the same or different, and R5 and R4 represent hydrogen, an n-substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted benzyl group. 1 The photoconductive compound represented by the above general formula used in the present invention is disclosed in JP-A-52-128373 and JP-A-55-1.
No. 612/I7.

The alkali-soluble resin used in the present invention refers to a resin that becomes soluble in an aqueous or alcoholic solvent by adding an alkali. In view of objective 4 of the present invention, in addition to properties such as film-forming properties, electrical properties and adhesion strength to a support, solubility properties are particularly important for these resins. Examples of resins having such characteristics include styrene/maleic anhydride copolymer, styrene/methacrylic acid/methacrylate-1 to copolymer, methacrylic acid/methacrylate 1 (polymer, phenol resin, etc.) As the phenolic resin, phenol and 0-cresol are used.

m-cresol, p-cresol, ethylphenol,
Isopropylphenol, 1-butylphenol, [-
amylphenol, hexylphenol, t-octylphenol, cyclohexylphenol, 3-methyl-
At least one phenol such as 4-chloro-6-1-butylphenol, isopropylcresol, I-butylcresol, t-amylcresol, hexylcresol, t-octylcresol, and cyclohexylcresol and formaldehyde, acetaltehyde, acrolein. , crotonaltehyde, furfural, and other aldehydes are condensed under acidic conditions↑! ↑Rakuru novolac type resin is used.

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

Examples of dye sensitizers include Brilliant Clean,
Victoria Blue B, Methyl Violet, Crystal Violet, Rhodamine B1-Tamine F B , Rhodamine G Extra, Sulforhodamine B, Fast Asindoeosin G, Loose Bencal, Fluorescein, Methylene Blue.

Acridine Yellow, Acridine Orange, Trivaflapine, Cryptocyanin, Alizarin, Astrazone Yellow 3G, Basic Yellow 52115, Asl Herathon Orange R, Malachite Green, etc. are used.

Examples of chemical sensitizers include quinones such as p-benzoquinone and chloranil, altehydes such as 4-nitropenthaldehyde, 2-ethoxy-1-naphthaldehyde, and anthracene-9-aldehyde, and 4-nitrophenol. Examples include acid anhydrides such as citric acid, maleic anhydride, and phthalic anhydride, ketones such as benzophenone benzoin and 9-acetyl-anthracene, organic phosphoric acids, and halogen dihydroboron compounds.

Furthermore, the printing plate of the present invention can contain a plasticizer. Effective plasticizers include, for example, phthalic acid esters such as dimethyl phthalate, diethyl phthalate, and dibutyl phthalate, and glue recall esters such as dimethyl glycol phthalate and ethyl phthalyl ethyl glycolate.

These plasticizers can be contained within a range that does not deteriorate the electrostatic properties and alkali solubility of the photoconductive layer.

(L″4'T4' T rest) The conductive substrate used in the present invention is an aluminum plate, a zinc plate, or a bimetallic plate such as a copper-aluminum plate, a copper-stainless steel plate, a chrome-copper plate, or a chromium plate. - Copper-aluminum plate.

A conductive substrate having a wood-loving surface such as a tri-metal plate such as a chrome-lead-iron plate or a chrome-copper-stainless steel plate is used, and its thickness is preferably 0.1 to 1 mm.

Also, especially in the case of supports with an aluminum surface, graining treatment, sodium silicate.

Preferably, the material has been subjected to surface treatment such as immersion treatment in an aqueous solution of potassium fluorozirconate or phosphate, or anodization treatment. Also, U.S. Patent No. 271
/1066, after graining treatment, sodium silicate wood? ? Aluminum fiber 1 immersed in i-liquid
It is also preferable to carry out an anodic oxidation treatment and then immersion treatment in an aqueous solution of an alkali metal silicate as shown in Japanese Patent Application Laid-Open No. 47-5125.

1-F'>14'i The oxidation treatment is performed using, for example, an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, or oxalic acid, or oxalic acid.

This is carried out by passing a positive (lx) current through the aluminum plate in an electrolyte consisting of a solution of an organic acid such as sulfamic acid or a salt thereof.

In addition, in the present invention, casein, polyvinyl alcohol,
Ethyl cellulose, phenolic resin.

An alkali-soluble intermediate layer such as a styrene/maleic anhydride copolymer or polyacrylic acid may be provided to improve the adhesion between the substrate and the Y6 conductive layer or the electrostatic properties of the photoconductive layer.

To produce the electrophotographic printing plate of the present invention, the photoconductive compound represented by the above general formula and additives such as the alkali-soluble resin and the dye R1 sensitizer are mixed with toluene, tetrahydrofuran, ethylene glycol monoethyl It is dissolved in a WI agent such as ether, methyl ethyl ketone, halogenated hydrocarbon, or ethyl acetate, applied onto the conductive substrate, and dried.

The photoconductive layer has a thickness of 1 to 30μ, preferably 2 to 15μ.
It is created so that The proportion of the photoconductive compound in the photoconductive layer is suitably 10 to 60% by weight.

The printing plate of the present invention is charged with a conventional electrophotographic method, and then charged with a light source such as a halogen lamp, a tungsten lamp, or a fluorescent lamp.
Alternatively, a toner image is obtained by exposing to laser light such as an argon laser and then developing with a hydrophobic and ink-receptive toner.

After forming the image, it is heated and fixed using a heat roller, heat rays, etc.

Next, the non-image area (toner) is removed by immersion in an eluent consisting of an alkaline aqueous solution such as a sodium silicate aqueous solution or a sodium phosphate aqueous solution, an organic solvent containing an alkaline salt or an organic amine such as ethanolamine, or a mixture thereof. (unattached parts).

Then, by washing with water and drying, only the image-drawing area (toner-attached area) remains on the surface of the support, and a good printing plate can be obtained. Additives such as surfactants can be added to the eluate.

Furthermore, the printing plate of the present invention may contain a quinonediazide compound such as 0-naphthoquinone siacite for the purpose of increasing the solubility of the recording layer by full-surface exposure after toner image formation.

The printing plate of the present invention prepared by the method described above has particularly high stability during printing operations and excellent printing durability. The photosensitive layer of the printing plate of the present invention can also be used for manufacturing printed wiring boards.

The present invention will be explained below in terms of H1 based on Examples.

Photoconductive compound log of Example 1 Styrene/maleic anhydride copolymer 0.5 g
Rhodamine FB 180 g Tetrahydrofuran The above solution was applied using a 0.25 inch thick aluminum wire bar with a grained and anodized surface and dried at 100°C for 20 minutes to a thickness of approx.
A printing plate with a photosensitive layer of μ was prepared. This printing plate was charged to approximately -400v11- by corona discharge, and then exposed to light using a plate-making camera using a halogen lamp as a light source.
After n light, use toner to f! ? , and fixed to obtain a toner image. Next, this was immersed in a 1% aqueous sodium silicate solution for 1 minute, and then washed with a water stream while being lightly brushed. The dry printing plate with the non-image area removed in this manner was run on an offset printing machine to obtain 100,000 good prints.

10 g of photoconductive compound of Example 2 0.5 g of styrene/maleic anhydride copolymer
Astrazone Orange R 180 g Tetrahydrofuran The above solution was applied to an aluminum plate whose surface was grained and subjected to positive t4i oxidation treatment to prepare a printing plate having a photosensitive layer about 5 μm thick. After this printing plate was charged to about -/100 V by corona discharge, it was exposed to light of 488 nm 12 - using an IOmW argon laser, and developed and fixed with toner to obtain a toner image. Next, as in Example 1, the non-circular portion tL was removed, and then an offset printing machine was used to obtain 100,000 good prints.

10 g of photoconductive compound of Example 3 0.5 g of methyl methacrylate (80%)/methacrylic acid (20%) copolymer 180 g of rhodamine FB Tetrahydrofuran Same as in Example 1 except that the photosensitive layer was formed using the above solution. I obtained too many good prints.

10 g of photoconductive compound 1-cresol formaltehyde 1 fat 0.5 g Astrazone Orange R 180 g ethylene cucol monoethyl ether The same procedure as in Example 2 was carried out, except that the photosensitive layer was formed using the above solution. ]00,000 good prints 11
is.

Patent applicant: Ricoh Co., Ltd. 15- 417-

Claims (1)

[Claims] In an electrophotographic printing plate having a layer containing an organic photoconductive compound and an alkali-soluble resin on a conductive support, a compound represented by the following general formula is used as the organic photoconductive compound. A printing plate for electrophotographic engraving characterized by the following. 1-4 alkoxy group, or C1-4 alkyl group, R3 is hydrogen, halogen, C1-4 alkyl group, C1-4 alkoxy group, or represents a dialkylamino group, n is 1 or 2; when n is 2, R4 may be the same or different; Rr and R6 are hydrogen, substituted or unsubstituted alkyl having 1 to 4 carbon atoms; or substituted or unsubstituted benzyl group.