Abstract: A electrophotographic printing plate precursor comprising an electrically-conductive support having thereon a photoconductive layer containing at least photoconductive pigments and a binder resin, wherein said photoconductive pigments are phthalocyanine pigments and said photoconductive layer further comprises a compound represented by the general formula (I), (II) or (III): ##STR1## wherein Z represents a sulfur or oxygen atom; Ar represents a monovalent aromatic hydrocarbon group or monovalent heterocyclic group; R.sub.3 represents a hydrogen atom, alkyl group, aryl group or aralkyl group; Ar and R.sub.3 may together form a ring; and R.sub.1 and R.sub.2, which may be the same or different, each represents an alkyl group, aryl group or aralkyl group, with the proviso that the aromatic hydrocarbon group and heterocyclic group represented by Ar and the alkyl, aryl and aralkyl group represented by R.sub.1, R.sub.2 and R.sub.

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: An electrophotographic liquid developer is disclosed. The developer is comprised of resin particles dispersed in a high-insulating low dielectric non-aqueous solvent. The resin particles are prepared by polymerizing or copolymerizing a specific styrenic monomer in an organic solvent containing a polymer which is substantially soluble in the organic solvent. The liquid developer is particularly suitable for making a printing plate or sheet by an electrophotographic process.

Abstract: A printing plate precursor for electrophotographic printing plate making purposes wherein the binder resin used for a photoconductive layer comprises a copolymer of at least one vinyl ester compound or allyl ester compound having an aromatic ring as a monomer component and at least one vinyl polymerizable monomer containing at least one acidic functional group as a monomer component.

Abstract: An electrophotographic printing plate comprising a conductive support having provided thereon a photoconductive insulating layer containing:(1) at least one organic photoconductive compound,(2) at least one sensitizer selected from the group consisting of compounds represented by formula (A-I), (A-II), (B), (C-I), (C-II), (C-III), (C-IV), (D) or (E); ##STR1## . (3) at least one amide compound selected from the group consisting of compounds represented by formula (I), (II), or (III); ##STR2## and (4) a binder resin soluble or dispersible in an alkaline solvent (wherein symbols in formulae are defined as in claim 1). The printing plate exhibits high sensitivity sufficient to respond to a laser light source and provides a printing plate free from background stains.

Abstract: An electrophotographic printing plate comprising a conductive support having provided thereon a photoconductive insulating layer containing:(1) at least one organic photoconductive compound,(2) at least one sensitizer for said at least one organic photoconductive compound represented by formula (I); ##STR1## wherein Bu.sup.t represents a t-butyl group; R.sub.1 and R.sub.2, which may be the same or different, each represents a hydrogen atom, a substituted or unsubstituted alkyl group having from 1 to 5 carbon atoms, or a substituted or unsubstituted aryl group having from 6 to 18 carbon atoms; R.sub.3, R.sub.4, R.sub.5, and R.sub.6, which may be the same or different, each represents a hydrogen atom, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 5 carbon atoms, or a halogen atom; and Z.sup..crclbar. represents an anion; and (3) a binder resin soluble or dispersible in an alkaline solvent.

Abstract: A transparent electrophotographic photoreceptor comprising a conductive support having provided thereon a photosensitive layer is disclosed, wherein said photosensitive layer contains a combination of at least one of specific hydrazone compounds and at least one of specific benzidine compounds as photoconductive substances. These photoconductive substances are prevented from crystallization and precipitation on the surface of the photoreceptor so that the photoreceptor exhibits satisfactory stability before and after image formation even when preserved for long periods of time or under a high temperature condition.

Abstract: An image-forming process using a long rolled transparent light-sensitive recording material is disclosed. The process comprises applying at least two image-forming steps each including at least an image exposure and a development to a long rolled transparent light-sensitive recording material comprising a support having thereon a light-sensitive layer and a surface protective layer containing a hardenable compound and fine particles. The recording material preferably has a backing layer containing fine particles.

Abstract: A novel electrophotographic liquid developer is provided, comprising a coloring agent, a coating agent, a dispersant, an electric charge adjustor, and a carrier liquid, wherein said coating agent is a copolymer of a long-chain alkyl acrylate or methacrylate and a methyl methacrylate, and has a softening temperature within the range of from 40.degree. to 140.degree. C. and a number-average molecular weight of from 5.times.10.sup.3 to 1.times.10.sup.5. The long-chain alkyl group is a straight-chain or branched alkyl group having from 8 to 22 carbon atoms. In preferred embodiments, the long-chain alkyl methacrylate is 2-ethylhexyl methacrylate, lauryl methacrylate, or stearyl methacrylate.

Abstract: A negative-working image forming process which comprises uniformly exposing a photosensitive material comprising a support having thereon a sensitive layer comprising (i) an o-quinonediazide compound and (ii) a second compound, to actinic radiation which is able to convert the o-quinonediazide compound to the corresponding indenecarboxylic acid compound, and subsequent to said uniformly exposing imagewise exposing said exposed photosensitive material to a laser beam to thereby render the indenecarboxylic acid compound of the imagewise exposed areas convert to the corresponding indene compound and developing with an alkaline developing solution to dissolve out the unexposed area to the laser beam, wherein said second compound reduces the rate of dissolution of the laser exposed areas in the developing solution by converting the indenecarboxylic acid to the corresponding indene compound, whereby said image results.

Abstract: A liquid developer for electrostatic images which comprises toner particles dispersed in a nonaqueous medium having an electrical resistance of 10.sup.9 .OMEGA..multidot.cm or more and a dielectric constant of 3 or less, wherein said toner particles are composed of a resin polymer comprised of monomer units selected from the group of monomers represented by the following formula (I) and a coloring agent: ##STR1## wherein X represents ##STR2## and n represents an integer of 1-6, wherein R.sup.1 and R.sup.2 each represents an alkyl group having 1-18 carbon atoms, and alkyl substituted or nonsubstituted aryl group (the substituent being an alkyl group having 1-12 carbon atoms), or an aralkyl group (substituent alkyl groups in case that the benzene nucleus is substituted by alkyl groups have 1-12 carbon atoms, and the alkylene group has 1-12 carbon atoms).

Abstract: A light-sensitive material having on a support a light-sensitive layer containing an o-quinonediazide compound as a main component and, additionally, a particular compound represented by the following general formula (I): ##STR1## wherein Z represents the nonmetallic atoms forming a 5-membered ring; X represents S, O, ##STR2## or .dbd.N--R.sub.c (where R.sub.a, R.sub.b and R.sub.c are each a hydrogen atom or an organic group other than a carboxylic acid group); and Y is a hydrogen atom or an organic group other than a carboxylic acid group, is disclosed. This material can provide both positive and negative working images having high resolution and good adhesiveness to the support. A process for producing positive working images includes the steps of imagewise exposure and development processing, while a process for producing negative working images includes the steps of imagewise exposure, heating, uniform (overall) exposure and development processing.

Abstract: A process for forming an image is disclosed wherein a photosensitive image-forming material comprising a diazonium compound or an azide compound is exposed and developed by a peeling development method wherein a development carrier sheet having thereon a layer of an adhesive composition is adhered to the image-forming material, before or after exposure, and, after exposure, peeled from the image-forming material whereby the exposed areas of the photosensitive layer are adhered to the carrier sheet thereby forming a relief image, and the unexposed areas remaining adhered to the support also forming a relief image.

Abstract: A novel desensitizing solution is disclosed which is applied to the surface of a lithographic printing plate coated with a photosensitive layer of a photopolymerizable composition, the desensitizing solution contains a hydrophilic colloid, a free radical polymerization inhibitor and water.

Abstract: An image-forming method is described using a light-sensitive material comprising a support and a light-sensitive layer on the support, said light-sensitive layer containing an o-quinonediazide compound as a first component and a basic carbonium dye as a second component; according to this method images can be obtained both by positive working and negative working techniques. Furthermore, images which are free from yellow light fogging can be obtained by use of a laser beam.

Abstract: A photosensitive member comprising a photosensitive layer containing an o-quinonediazide compound as a photosensitive agent and an additive, characterized in that the additive is selected from a group consisting of quinone compounds and aromatic ketone compounds, and a method for forming an image using the same.

Abstract: A process for forming an image is disclosed wherein a photo-sensitive material composed of a support and a layer of a photo-sensitive composition containing a diazonium compound, an o-quinonediazide compound or an aromatic azide is exposed and developed by heating in intimate contact with a peeling development carrier sheet, and subsequently, peeling the carrier sheet from the photo-sensitive material.

Abstract: A novel desensitizing solution is disclosed which is applied to the surface of a lithographic printing plate coated with a photosensitive layer of a photopolymerizable composition, the desensitizing solution contains a hydrophilic colloid, a free radical polymerization inhibitor and water.

Abstract: A desensitizer for a lithographic printing plate, which contains:(i) at least one silicate represented by the general formulae (I), (II) and (III)M.sub.2 O.(SiO.sub.2).sub.n.qH.sub.2 O (I) ##STR1## wherein M represents an alkali metal atom; R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, each represents a hydrogen atom, an alkyl group or a hydroxyalkyl group; n represents a number of from 1 to 8.5; q represents a number of from 0 to 12; m represents a number of greater than 0 and up to 10; and p represents a number of from 4 to 5000;(ii) at least one wetting agent;(iii) a hydrophilic colloidal material; and(iv) water, anda process for preparing a lithographic printing plate using the desensitizer.

Abstract: A process for forming an image is disclosed wherein a photo-sensitive image-forming material composed of a support and a layer of a thermoplastic photo-sensitive composition which is not adhesive at ordinary temperatures, is exposed and developed by heating in intimate contact with a peeling development carrier sheet at least one surface of which is composed of a thermoplastic material not adhesive at ordinary temperatures, and, subsequently, peeling the development carrier sheet from the photo-sensitive image-forming material.