GB883782A - Composite sheet materials for electrophotography - Google Patents

Abstract

An electrophotographic plate comprises a paper or metal support coated with a dispersion in a resinous binder of a photoconductive condensation product of an aromatic aldehyde with a heterocyclic compound, containing at least one active methyl group, of the formula: <FORM:0883782/III/1> in which the bracketed groups are attached to the heterocyclic ring in the 2 or 4 position and in which Y represents members of a heterocyclic six membered ring to which may be fused, for example, a substituted or unsubstituted benzene or naphthalene ring, X is an acid radical, n is 0 or 1, m is 1, 2 or 3 and R represents one or more similar or different substituents from:-a halogen atom, an alkyl or aryl radical, or a nitro, amino, hydroxy, alkylamino, arylamino, alkoxy or aryloxy group. The substances, 12 examples of which are given, may be used in the cis or trans form. Any of the dye sensitizers described in Specification 811,165 may be added to the coating material which preferably contains 1 part by weight of photoconductive compound to ,3 to 2 parts binder. Suitable binders are alkyl and aryl polysiloxanes, cellulose, cellulose ethers and esters, polyvinyl chloride, polyurethanes, polyesters, polyamides and polycarbonates. The layer is deposited from a dispersion of the photoconductor formed by adding to a solution of the photoconductor and binder a solvent in which the photoconductor is insoluble and the binder soluble. Alternatively the layer is formed from an aqueous dispersion of the photoconductor and binder. Binders suitable for application in this way are melamine-formaldehyde, urea-formaldehyde, and xylene-formaldehyde resins, polymers and copolymers based on vinyl chloride, vinylidene chloride, vinyl ethers, acrylic and methacrylic esters, acrylic amides, aromatic vinyl compounds, iso-olefines, synthetic elastomers such as copolymers of styrene and butadiene, or butadiene and acrylonitrile, copolymers of dienes with a preponderant proportion of styrene or acrylonitrile or other vinyl compounds; polyamides, polyurethanes, polyesters of polycarboxylic acids and polyhydric alcohols, polycarbonates, cellulose esters and rubber. An exemplary coating composition is described. Specifications 663,849, 772,627, 775,812 and 808,485 also are referred to.ALSO:<FORM:0883782/IV (a)/1> A supported layer for use as an electrophotographic plate (see Group XXXVI) comprises, dispersed in a resinous binder, a photoconductive condensation product of an aromatic aldehyde with a heterocyclic compound, containing at least one active methyl group of the formula: <FORM:0883782/IV (a)/2> in which the bracketed groups are attached to the heterocyclic ring in the 2 or 4 position and in which Y represents members of a heterocyclic six-membered ring to which may be fused for example a substituted or unsubstituted benzene or naphthalene ring, X is an acid radical, n is 0 or 1, m is 1, 2, or 3 and R represents one or more similar or different substituents from:- a halogen atom, an alkyl or aryl radical, or a nitro, amino, hydroxy, alkylamino, arylamino, alkoxy, or aryloxy group. The substances, 12 examples of which are given, may be used in the cis or trans form. Any of the dye sensitizers described in Specification 811,165 may be added to the layer which preferably contains 1 part by weight photoconductive compound to ,3 to 2 parts binder. Suitable binders are alkyl and aryl polysiloxanes, polyvinyl chloride, polyurethanes, polyesters, polyamides, and polycarbonates, melamine-formaldehyde, urea-formaldehyde, and xylene-formaldehyde resins, polymers and copolymers based on vinyl chloride, vinylidene chloride, vinyl ethers, acrylic and methacrylic esters, acrylic amides, aromatic vinyl compounds, iso-olefines, synthetic elastomers such as copolymers of butadiene and styrene, or butadiene and acrylonitrile, copolymers of dienes with a preponderant proportion of styrene, acrylonitrile or other vinyl compounds, polyamides, polyurethanes, polyesters or polycarboxylic acids and polyhydric alcohols and polycarbonates. In the example 20 grams of the compound of the formula shown in Fig. 2 are ball milled with 2,5 grams of the copolymer of 30 parts by weight acrylonitrile and 70 parts methyl methacrylate dissolved in 1,00 cc. of formamide and deposited on a support. Specifications 633,849, 772,647, 775,812 and 808,485 also are referred to.