GB1261360A - Electrophotographic elements and their use - Google Patents

Abstract

1,261,360. Photo-conductive imaging member. XEROX CORP. 31 Dec., 1968 [2 Jan., 1968], No. 61835/68. Heading H1K. [Also in Division G2] An imaging member comprises a substrate comprising a layer of electrically conductive material, a layer consisting of carbon particles overcoating said conductive layer and a layer of solvent soluble insulating material and having particulate or fracturable photo-conductive migration material therein or thereon, the soluble layer being soluble in a solvent wherein the substrate, carbon particles and migration material are insoluble. The imaging member is developed after charging and image-wise exposure in a two-step process whereby in a first step a solvent for said soluble layer is used whereby the migration material forms an image lying on the particulate carbon layer and in the second step the conductive layer is dissolved away together with a portion of the particulate carbon layer to give respectively a positive or negative image according to whether the solvent for the conductive layer 12 simultaneously dissolves the migration material 15 and the carbon layer 13 thereunder (Fig. 5, not shown) or the carbon layer not covered by the migration material (Fig. 6, not shown). An insoluble support 11 of glass, paper or plastics has a conductive film 12 of Al, Sn O 2 , Sn, In, Cu 2 I 2 or Cu 2 S and an overlying film 13 of graphite, charcoal, coke, carbon black, lamp black or activated carbon which may be formed by coating with a colloidal carbon solution and drying, or dusting or cascading carbon particles on the film. The solvent softenable layer 14 is preferably a hydrogenated glycerol rosin ester but many other plastics materials and sucrose benzoate are specified. Particles 15 of vitreous selenium are deposited on the layer 14 by vapour phase deposition. Other suitable photo-conductors are specified. These may be in the form of a continuous or semi-continuous layer which is capable of breaking up during the first development stage. The particles may also be applied to the heat or solvent softened layer 14 by dusting or coating with a slurry. In other embodiments, the particles may be sandwiched between two plastics layers or dispersed in the layer 14.