Abstract: A liquid electrophotographic developing device for developing a charged and exposed photoconductive material which includes a photoconductive layer formed on one surface of a conductive layer. The liquid electrophotographic developing device is comprised of developing section, a developing solution tank provided in a housing and filled with a developing solution, conveying rollers for conveying the photoconductive materials, a developing electrode and a back electrode which are disposed parallel along a conveying path of the photoconductive material in the developing section, and a developing solution supplying device disposed above the developing electrode. The developing electrode is spaced part from the photoconductive layer, and the back electrode is disposed to come into contact with the back surface of the photoconductive material. Upon directly connecting the electrodes, toner particles contained in the developing solution adhere to the photoconductive layer to achieve development.

Abstract: A liquid electrophotographic developing device for developing a photoconductive material charged and exposed and which has a photoconductive layer formed on one surface of a conductive layer comprises a developing tank filled with a developing solution in which a developing electrode and a back electrode are disposed. The electrodes are immersed in the developing solution and disposed on either side of the photoconductive material in conveyance. The back electrode comes into contact with the back surface of the photoconductive material, whereas the developing electrode is spaced part from the photoconductive layer. Upon directly connecting the electrodes, toner particles contained in the developing solution adhere to the photoconductive layer to achieve development.

Abstract: A method and an apparatus for developing a photosensitive lithographic plate at least one layer of which has been exposed with an image by a developer with conveying the same with the one layer facing substantially downwards, the method and apparatus being arranged in such a manner that the developer is supplied to the one layer and the thus-supplied developer is retained on the same layer.Therefore, the photosensitive lithographic plate can be developed without any necessity of being dipped in the developer.

Abstract: A liquid electrophotographic development method where electrodes are arranged only on the side of the photosensitive layer of a master, developing liquid is supplied between the master and the electrodes, and conductors are made to come into contact with the base of the master so that an electric field is generated between the photosensitive plane and the electrodes for development. The electrode to be used for the electrophotographic development method includes conductive wires of a plural number which are arranged in the direction perpendicular to the traveling direction of the material so as to come into contact with the conductive base thereof. If the electrodes are utilized, a main electrode needs to be arranged only on the side of the photosensitive layer of the master, and developing liquid is supplied therebetween. The electrode is adapted to come into contact with the conductive base of the master, to thereby generate an electric field between the main electrode and the electrode.

Abstract: An electrophotographic lithographic printing plate precursor which is suitable for not only the ordinary developing methods but also the developing methods of direct electron injection system and which after developing, can readily be wound and fixed, as a lithographic printing plate, around a drum of a printing machine without any slippage after winding is provided. This precursor comprise a base of paper coated, on both surfaces thereof, with .alpha.-polyolefin laminated layers each having a volume resistivity of at most 1.times.10.sup.10 .OMEGA. and being further provided, on one side thereof, with a photoconductive layer and on the other side thereof, with an over back layer having a surface resistivity of at most 1.times.10.sup.10 .OMEGA. and a larger friction coefficient than the .alpha.-polyolefin laminated layer.

Abstract: An electrophotographic lithographic printing plate precursor capable of giving a good image free from pinholes is provided which comprises an electrically conductive base coated, on one side thereof, with an undercoated layer and a photoconductive layer containing zinc oxide as a predominant component in order and on the opposite side thereof, with a back layer, said undercoated layer having a surface resistivity of 1.times.10.sup.8 to 1.times.10.sup.14 .OMEGA. and said back layer having a surface resistivity of at most 1.times.10.sup.10 .OMEGA..

Abstract: An electrophotographic lithographic printing plate is described, comprising an electrically conductive support and a photoconductive layer on the support, said layer being made mainly of a photoconductive zinc oxide and a resin binder, wherein in the surface of the photoconductive layer, the degree of exposure of photoconductive zinc oxide is from 10% to 70%.

Abstract: A method for removing liquid from the surface of a plate-shaped material, for instance, as applied to removing surface treatment liquids from metal plates of photographic film. While the plate-shaped material is being conveyed, a larger part of the liquid is removed from its surface by a first liquid removing device having a solid scraping surface positioned adjacent the surface of the plate-shaped material. This first liquid removing device may be a scraper blade or a pair of rollers. Subsequently, liquid remaining on the surface of the plate-shaped material is removed by a second liquid removing device, specifically, an air knife. The air flow rate and air pressure used with the air knife are sufficiently low that there is no significant scattering of liquid from the surface of the plate-shaped material.

Abstract: An electrophotographic photoreceptor having on a conductive support an interlayer and a photoconductive photoreceptive layer in that order, with the interlayer containing at least one colloidal substance selected from colloidal silica and colloidal alumina, and an organic solvent soluble resin which is composed of(A) a polymer having an acid value of from 10 to 100 and containing repeating units represented by formula (I) and (II) ##STR1## wherein R.sub.1 represents H or CH.sub.3 ; R.sub.2 represents H, --CH.sub.3, --C.sub.2 H.sub.5, or a chloromethyl group; and n represents an integer of 1 to 10; ##STR2## wherein R.sub.3 represents H or --CH.sub.3 ; and (B) at least one polymer selected from a homopolymer and a plural copolymer having a glass transition point (Tg) of from -70.degree. to 20.degree. C., which can be utilized as a lithographic printing material having long press life.

Abstract: An electrophotographic plate making material comprising a substrate comprising a paper support and a polyolefin laminate layer on at least one surface thereof and having a volume resistance of 10.sup.10 ohms or less, and a photoconductive layer on the substrate.

Abstract: A process for producing a printing plate and a printing plate making machine are disclosed. The process involves providing an electrophotographic plate making material which includes a base having a low conductive layer thereon. The material is electrically charged and imagewise exposed. The imagewise exposed material is subjected to liquid toner development with a toner containing a solvent. The solvent is then substantially removed by heating the material to a temperature sufficient to cause the evaporation of the solvent. The material is then moved to a substantially isolated fixing area and again heated in order to fix a toner image on the plate making material. The process can be quickly and easily carried out and eliminates the danger of the explosion of solvent vapors.

Abstract: A presensitized lithographic printing plate, which comprises a support having a hydrophilic surface. A non-silver light-sensitive layer capable of having formed therein a lipophilic image pattern and a direct positive light-sensitive silver halide emulsion layer are provided on the support in that sequence. The non-silver light-sensitive layer is provided with an adjacent hydrophilic colloid layer in which a resin is dispersed in fine particle form. The resin is a copolymer comprising (A) a recurring unit derived from at least one monomer of acrylic acid and methacrylic acid, and (B) a recurring unit derived from at least one monomer of an aralkyl acrylate and an aralkyl methacrylate.

Abstract: A photosensitive material for lithographic printing comprising a photosensitive layer, an aluminum foil and a paper base in that order. An intermediate layer containing colloidal silica and/or colloidal alumina is formed between the photosensitive layer and the aluminum foil. The material has good stability and can produce a large number of high quality printed copies.

Abstract: A light-sensitive composition comprising addition polymerizable ethylenically unsaturated double bond-containing compounds and a photopolymerization initiator comprising (1) at least one compound selected from the group consisting of benzanthrone, substituted benzanthrones (the substituents of which include halogen atoms, alkyl groups having 1 to 5 carbon atoms and alkoxy groups having 1 to 5 carbon atoms), 1,2-benzanthraquinone and substituted benzanthraquinones (substituents of which include halogen atoms, alkyl groups having 1 to 5 carbon atoms and alkoxy groups having 1 to 5 carbon atoms) and (2) at least one compound selected from the group consisting of 4,4'-di-substituted amino-benzophenones represented by the following general formula (a), p-substituted amino-benzaldehyde derivatives represented by the following general formula (b), 2-(p-substituted amino-phenyl)-1,3-dioxolanes represented by the following general formula (c), 4,4'-bis(substituted amino)-N-benzylideneanilines represented by the follow

Abstract: By treating an imagewise exposed and developed image-forming material comprising a support and a light-sensitive resin composition layer with organic solvents miscible with water or with a mixture of water and organic solvents miscible with water, elimination of non-image areas is completed.

Abstract: The formation of spots when making a printing plate using a presensitized printing plate comprising a silver halide light-sensitive layer formed on an aluminum support having an aluminum oxide film on the surface directly or over a non-silver light-sensitive intermediate layer is effectively prevented by incorporating a mercapto compound in one of the layers.

Abstract: A light-sensitive composition comprising addition polymerizable ethylenically unsaturated double bond-containing compounds and a photopolymerization initiator comprising (1) at least one compound selected from the group consisting of benzanthrone, substituted benzanthrones (the substituents of which include halogen atoms, alkyl groups having 1 to 5 carbon atoms and alkoxy groups having 1 to 5 carbon atoms), 1,2-benzanthraquinone and substituted benzanthraquinones (substituents of which include halogen atoms, alkyl groups having 1 to 5 carbon atoms and alkoxy groups having 1 to 5 carbon atoms) and (2) at least one compound selected from the group consisting of 4,4'-di-substituted amino-benzophenones represented by the following general formula (a), p-substituted amino-benzaldehyde derivatives represented by the following general formula (b), 2-(p-substituted amino-phenyl)-1,3-dioxolanes represented by the following general formula (c), 4,4'-bis(substituted amino)-N-benzylideneanilines represented by the follow

Abstract: A photosensitive lithographic printing plate precursor comprising a support having a hydrophilic surface and having thereon a non-silver photosensitive layer capable of forming a water-insoluble oleophilic image and a hardened gelatino silver halide photosensitive emulsion layer on the non-silver photosensitive layer.

Abstract: A process for producing a lithographic printing plate from a light-sensitive lithographic printing plate comprising a support, a non-silver light-sensitive layer which is provided on the support and which forms a water-insoluble lipophilic image and a gelatino-silver halide light-sensitive emulsion layer on the non-silver light-sensitive layer, which process comprises the steps of:(a) imagewise exposing the light-sensitive lithographic printing plate;(b) developing the gelatino-silver halide light-sensitive emulsion layer;(c) exposing the non-silver light-sensitive layer to light;(d) washing out the gelatino-silver halide light-sensitive emulsion layer in the presence of a proteolytic enzyme; and(e) developing the non-silver light-sensitive layer.

Abstract: A light-sensitive composition comprising addition polymerizable ethylenically unsaturated double bond-containing compounds and a photopolymerization initiator comprising (1) at least one compound selected from the group consisting of benzanthrone, substituted benzanthrones (the substituents of which include halogen atoms, alkyl groups having 1 to 5 carbon atoms and alkoxy groups having 1 to 5 carbon atoms), 1,2-benzanthraquinone and substituted benzanthraquinones (substituents of which include halogen atoms, alkyl groups having 1 to 5 carbon atoms and alkoxy groups having 1 to 5 carbon atoms) and (2) at least one compound selected from the group consisting of 4,4'-di-substituted amino-benzophenones represented by the following general formula (a), p-substituted amino-benzaldehyde derivatives represented by the following general formula (b), 2-(p-substituted amino-phenyl)-1,3-dioxolanes represented by the following general formula (c), 4,4'-bis(substituted amino)-N-benzylideneanilines represented by the follow