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 novel electrophotographic photoreceptor for copying machine or photoprinter is provided comprising on an electrically conductive support a photoconductive layer, characterized in that said photoconductive layer contains a phthalocyanine pigment and a compound represented by the general formula (I), (II), (III), (IV) or (VI): ##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 may be the same or different and each represents an alkyl group, aryl group or aralkyl group, ##STR2## wherein Z represents a sulfur or oxygen atom; R.sub.4 represents an alkyl group, alkoxy group, monovalent or bicyclic condensed aryl group, monocyclic or bicyclic condensed aryloxy group or monovalent group derived from heterocyclic group; the two R.sub.

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: A liquid developer for electrostatic charge images comprising a polymer selected from (a) a polymer containing at least one polymerizable monomer represented by the following general formula (1) as a component of the polymer, and (b) a polymer containing at least one polymerizable monomer represented by the following general formula (2) and chloromethylstyrene a copolymer components, the polymer being dispersed in a carrier liquid having an electric resistance of at least 10.sup.9 .OMEGA..cm and a dielectric constant of at most 3, ##STR1## wherein all the symbols are defined in the specification.

Abstract: The present invention provides a process for preparation of a charge-regulatory agent characterized by reacting an amino acid with a titanium compound in an organic solvent to form a reaction mixture and further reacting the resultant reaction mixture with water which is equimolar or more to said titanium compound, and a liquid developer for development of an electrostatic image comprising a dispersion of resin-containing toner particles dispersion in a carrier solution having an electric resistance of 10.sup.9 .OMEGA..multidot.cm or more and a dielectric constant of 3.5 or less and containing said charge-regulatory agent prepared as mentioned above.When an electrostatic latent image is developed with the present liquid developer containing the special charge-regulatory agent, an image of excellent resolving power, good half-tone reproduction and excellent gradation may be obtained without the occurence of any image flow.

Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor contains a specific styryl dye in which the tertiary amino moiety is substituted with aryl groups and a specific organic photoconductive compound in which the nitrogen atoms are substituted with aryl groups. The photoreceptor exhibits high sensitivity and excellent preservation stability and heat stability.

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 liquid developer for electrostatic images which comprises at least one charge controlling agent selected from the group consisting of compounds represented by formula (I) or (II) and complex salts containing a molecular structure shown by the formula (I) or (II): ##STR1## wherein R.sup.1 and R.sup.2 each represents a hydrogen atom, an alkyl and substituted alkyl group, an aryl and a substituted aryl group, an aralkyl group, an aliphatic acyl group, an aromatic acyl group, an alkylsulfonyl group, an arylsulfonyl group, R.sup.1 and R.sup.2 represent identical group or different groups, or R.sup.1 and R.sup.2 together form a heterocyclic ring with the nitrogen atom in the formulae, and when one of R.sup.1 and R.sup.

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).