Porous reusable zno electrophotographic element

Abstract

A reusable electrophotographic element comprising a photoconductive layer containing sensitized zinc oxide particles and first and second binding agents that are incompatible is produced by employing as the first binding agent a macromolecular compound that has a higher affinity to zinc oxide than the second binding agent, is largely deposited on the zinc oxide, has an average molecular weight of at least 12,000 and is present in the photoconductive layer in an amount of 1.5 to 9% by weight calculated on the zinc oxide, with the second binding agent present in substantially larger amount. The photoconductive layer is formed of agglomerates of zinc oxide particles substantially enveloped in the first binding agent, which agglomerates have a diameter of between 2.5 and 6 .mu.m and are stuck together by portions of the second binding agent, thus providing a substantially porous photoconductive layer having a negative charge density of at most 1 m Coulomb per m.sup.2. The photoconductive layer is produced by mixing together the zinc oxide, any desired dye sensitizer, and solutions of the binding agents in one or more volatilizable solvents, applying a layer of the resulting dispersion to a substrate suited for electrophotography and drying the applied layer. The electrophotographic element has a very high resistance to both electrical and mechanical influences, thus being suited for long service life in an electrophotographic copying machine.