ELECTROPHOTOGRAPHIC PLATE AND THE METHOD FOR PRODUCING THE SAME

1,188,330. Photoconductive laminates. CANON CAMERA CO. Inc. 18 Sept., 1967 [22 Sept., 1966; 21 Nov., 1966], No. 42410/67. Heading B5N. [Also in Division H1] A laminate is disclosed comprising a translucent insulating layer, a photoconductive layer made by polymerizing a dispersion of a photoconductor in a solventless polymer system and a conductive layer. A solventless polymer system is defined as a liquid composition containing material such as monomer or prepolymer, capable of polymerizing to form a solid resin without evaporation of solvent. The monomer is preferably styrene, a methacrylic ester, or epoxy monomer whilst the prepolymer may be an epoxy resin containing dimers or trimers thereof, polyvinyl acetate or phenolic resin dissolved in epoxy monomer or styrene, vinyl acetate, methyl methacrylate or diallylphthalate dissolved in an alkyd or an unsaturated polyester resin. The photoconductor may be ZnO, CdS activated by Cu and halogen, CdSe, TiO 2 , CdZnS 2 , PbO, or the oxides, tellurides or iodides of Hg, Sb, Bi, Tl, In, Mo or Al, or anthracene, a carbazole or an imidazole. The conductive layer may be a foil or plate of Al, Cu, Fe or Sn, conductively coated paper, cloth or plastics or a metal-paper laminate. The translucent layer is preferably polyethylene, a polyamide, polypropylene, polytetrafluoroethylene, cellulose acetate or nitrate or polyethylene terephthalate. In one embodiment (Fig. 2, not shown) the conductive and the translucent layer are fed spacedapart over rollers and the composition fed into the space. In another embodiment the conductive layer is placed on a rigid support, the composition applied and then the translucent layer. The three-layered structure is given uniform thickness by traversing it with a roller or blade while the composition is still liquid (Figs. 3a and 3b, not shown). Polymerization of the composition may take place at room temperature or be aided by heating or radioactivity together with a catalyst or hardener.