Abstract: A method for preparation of a printing plate by an electrophotographic process comprising forming a peelable transfer layer mainly containing a resin (A) capable of being removed upon a chemical reaction treatment on the surface of an electrophotographic light-sensitive element, forming a toner image on the transfer layer by an electrophotographic process, heat-transferring the toner image together with the transfer layer onto a receiving material a surface of which is capable of providing a hydrophilic surface suitable for lithographic printing at the time of printing, and removing the transfer layer on the receiving material upon the chemical reaction treatment, wherein prior to or simultaneously with the formation of transfer layer a compound (S) which contains a fluorine atom and/or silicon atom is applied to the surface of electrophotographic light-sensitive element to improve releasability of the surface of electrophotographic light-sensitive element.

Abstract: A method of forming an electrophotographic color transfer image comprising forming at least one color toner image on a transfer layer provided on the surface of an electrophotographic light-sensitive element by an electrophotographic process and heat-transferring the toner image together with the transfer layer onto a receiving material wherein the surface of the electrophotographic light-sensitive element has an adhesive strength of not more than 200 gram.force, which is measured according to JIS Z 0237-1980 "Testing methods of pressure sensitive adhesive tapes and sheets" and the transfer layer mainly contains a thermoplastic resin (AH) having a glass transition point of not more than 140.degree. C. or a softening point of not more than 180.degree. C. and a thermoplastic resin (AL) having a glass transition point of not more than 45.degree. C. or a softening point of not more than 60.degree. C.

Abstract: A color image forming method which comprises forming a mono-color or multi-color toner image on an electrophotographic photoreceptor having a releasing surface by an electrophotographic process; forming a releasable transfer layer on the photoreceptor having the toner image formed thereon; transferring the toner image together with the transfer layer onto a primary receptor; and transferring the toner image together with the transfer layer from the primary receptor onto the final receiving material, and an apparatus for carrying out the image forming method.

Abstract: A method for preparation of a printing plate by an electrophotographic process comprising forming a toner image on a transfer layer capable of being removed upon a chemical reaction treatment provided on the surface of an electrophotographic light-sensitive element by an electrophotographic process, heat-transferring the toner image together with the transfer layer onto a receiving material a surface of which is capable of providing a hydrophilic surface suitable for lithographic printing at the time of printing, and removing the transfer layer on the receiving material upon the chemical reaction treatment wherein the transfer layer mainly contains a thermoplastic rein (AH) having a glass transition point of from 10.degree. C. to 140.degree. C. or a softening point of from 35.degree. C. to 180.degree. C. and a thermoplastic resin (AL) having a glass transition point of from -50.degree. C. to 45.degree. C. or a softening point of from 0.degree. C. to 60.degree. C.

Abstract: An electrophotographic material for color proofing which comprises a substrate, a photoconductive layer and a transfer layer in this order, wherein said photoconductive layer comprises a polymer (P) which contains at least one polymer segment (x) containing not less than 50% by weight of units having fluorine atom(s) and/or silicon atom(s) and at least one polymer segment (Y) containing units having photosetting and/or thermosetting group(s); a polymer (Q) which contains not less than 30% by weight of units represented by the formula I--CH(a.sub.1)--C(a.sub.2)(COOR.sub.3)--wherein a.sub.1 and a.sub.2 each represents independently a hydrogen atom, R.sub.3 represents a hydrocarbon group; and contains at least one polar group such as --PO.sub.3 H.sub.2, --SO.sub.

Abstract: An electrophotographic material for color proofing which comprises a substrate, a photoconductive layer and a transfer layer in this order, wherein said photoconductive layer comprises a polymer (P) which contains at least one polymer segment (X) containing not less than 50% by weight of units having fluorine atom(s) and/or silicon atom(s) and at least one polymer segment (Y) containing units having photosetting and/or thermosetting group(s); a polymer (Q) which contains not less than 30% by weight of units represented by the formula (I):--CH(b.sup.1)--C(b.sup.2)(COOR.sup.3)--wherein b.sup.1 and b.sup.2 each represents independently a hydrogen atom, and R.sup.3 represents a hydrocarbon group, and contains at least one one-functional macromonomer containing one or more units having polar group such as --PO.sub.3 H.sub.2, --SO.sub.

Abstract: An electrophotographic printing plate precursor which comprises a conductive support having provided thereon, in order, an intermediate layer and an electrophotographic photo-receptive layer, wherein the intermediate layer contains at least one compound having at least one amino group and at least one group selected from the group consisting of a carboxyl group, a sulfo group and a hydroxyl group, or a salt of the compound, whereby ink stains are prevented from sticking to the non-image area upon printing.

Abstract: A method for processing an electrophotographic lithographic printing precursor comprising a photoconductive layer provided on a conductive substrate, the photoconductive layer having a toner image formed thereon by an electrophotographic process, comprising measuring electronically the area of the nonimage area to be processed, treating the precursor with a processing fluid from a processing fluid reservoir to remove the nonimage area of the photoconductive layer, and adding replenisher by automatic means in accordance with the area of the measured nonimage area.

Abstract: A method for oil-densensitization treatment of a lithographic printing plate is disclosed, comprising treating the plate with an aqueous solution containing a silicate represented by the formula SiO.sub.2 /M.sub.2 O (wherein M is an alkali metal atom) and a water-soluble resin.

Abstract: A cyan-free desensitizing solution for use in offset printing comprising as the effective ingredients:(a) at least one member selected from the group of an ammonium salt and amine salt of inositol hexaphosphate ester;(b) a water-soluble cationic polymer; and(c) a low molecular weight electrolyte.

Abstract: A process for preparing a lithographic printing plate from an electrophotographic photosensitive material comprising a photoconductive insulating layer containing photoconductive zinc oxide and a thermoplastic insulating resin disposed on a waterproof support, said method comprising the steps of electrical charging, imagewise exposure, and development of the material in a wet developer having toner particles containing an oleophilic component dispersed in an insulating liquid carrier, thereby providing an oleophilic toner image, and heating the developed photosensitive material under such conditions that when an adhesive tape having a tackiness of 280 to 350 g/10 mm wide portion as measured by the 180.degree. peeling method of JIS C2107 (passed once between pressure rollers at 50 mm/sec) and which has been contact-bonded to the surface of said toner image-bearing photosensitive material by passage between a metal roll and a rubber roll pressed against said roll at a pressure of 6000 g/cm.sup.

Abstract: A process for producing a developer for electrostatic latent images comprising adding a solution (A) of a high-molecular weight compound having electron-donating functional groups dissolved in an organic solvent (1) which is a good solvent for the high-molecular weight compound to an organic solvent (2) in which the high-molecular weight compound is substantially insoluble, thereby depositing the high-molecular weight compound in a finely divided particle form, wherein an organic resin which is soluble in both of organic solvent (1) and organic solvent (2) is dissolved in at least one of solution (A) and organic solvent (2).

Abstract: A xerographic color reproduction imaging system is disclosed. This color system provides at least a two color image with one exposure and avoids the necessity of employing a registration step. A sensitized photoconductive layer is employed which is charged, selectively exposed and developed with a color toner. The photoconductive layer is then recharged and developed with toner of another color.

Abstract: A liquid developer for electrophotography is disclosed which comprises toner particles, a regulating agent composed of a copolymer of a half-alkylamide of maleic acid and .alpha.-diisobutylene and an electric insulating carrier liquid and, if desired, an organic acid.

Abstract: Novel liquid developers contain in a carrier liquid a toner produced by graft-copolymerization of an addition-polymerizable monomer represented by the formula: ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group and R.sub.2 represents an alkyl group having 6 to 20 carbon atoms, an addition-polymerizable monomer having an alkoxysilane group or a phenoxysilane group, and carbon black. The carrier liquid has a high electric resistance and a low dielectric constant.

Abstract: A manufacturing process for liquid developer intended for developing the electrostatic latent image characterized by polymerizing one or more kinds of addition-polymerizable monomers with a mixture containing pigment and polymerization initiator to thereby obtain a graft polymer of the monomers and the pigments and treating the resultant polymerized product with a polar solvent of 12 or higher in dielectric constant, and then dispersing the component of the resultant product insoluble in the solvent in the carrier liquid of the liquid developer with high electric resistance whereby (a) the electric resistance of the developer, (b) the uniformity of the charge of the toner in the developer, and (c) the length of charge stability are enhanced because of the treating step.