GB1313341A - Production of electrophotographic material - Google Patents

Abstract

1313341 Electro-phoretic production of electro-photographic paper RANSBORG CORP 19 June 1970 [19 June 1969] 29874/70 Heading C7B [Also in Division H1] Electro-photographic paper is produced by passing a conductive paper through a non-aqueous bath containing zinc oxide pigment and a resinous binder in a ratio of 2:1 to 1:4, the paper passing between the anode and cathode in the vicinity of the cathode with a voltage of at least 1000 volts applied between the electrodes. As binder an acrylic resin, a copolymer of styrene and butadiene, or a polyvinyl chloride copolymer may be used. The polymer may contain carboxyl groups, e. g. by addition of fumaric, acrylic, methacrylic, crotonic or itaconic acids; hydroxyl groups, e. g. by addition of allyl alcohol or hydroxyethyl methacrylate; or ethylenically unsaturated amine groups, e.g. by addition of dimethyl amino ethyl methacrylate. The organic solvent supporting the bath may be an aliphatic or aromatic hydrocarbon, e.g. naphtha, toluene or xylene; a ketone, an ester or a halogen-containing solvent, e.g. trichloroethylene. The bath may also contain a phthalein dye. Non-conductive paper may be rendered conductive by immersion in a surface active agent such as sodium lauryl sulphate (alternatives are listed). As shown a paper strip is passed through surface active agent 11, excess of which is removed by squegee 13, and then about cathode roller 15 disposed in electro-coating bath 14, the bath container forming the anode and through a drying zone to wind-up roller 19. The cathode may be of steel; the anode of ferrous material or zinc.