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AssigneeOce-Nederland B.V.
InventorsRoelof H. Everhardus, Gerard J. E. H. van Lomm
Estimating the term…
A multi-layered electrophotographic element providing significantly improved properties, and especially so for use as a "permanent" master in transfer photocopying, comprises a conductive support carrying a photoconductive charge generating layer and on top of the photoconductive layer a charge transporting layer containing homogeneously distributed in an insulating binder a charge transporting agent selected from among certain azines which may comprise one or more alkylsubstituents and/or heterocyclic groups with at least one nitrogen atom and/or phenyl or naphthyl groups. The charge transporting layer may also contain to advantage an activator for the charge transporting agent. Particularly effective activators are terephthalal dimalonitrile (TDM) and 1,3,7- trinitro-dibenzothiophene-5,5-dioxide (DBTO). The charge transporting layer preferably is applied to a very thin charge generating layer formed on an endless support, and which contains the charge generating compound in molecularly divided form. Photocopying can be carried out with enhanced permanence of the usefulness of the element by charging the element for each copying operation to not more than about 70% of its maximum chargeable surface voltage.
A multi-layered electrophotographic element comprising an electrically conductive support carrying a photoconductive layer containing at least one radiation-sensitive charge generating compound, and applied to the photoconductive layer a charge transporting layer containing as a charge transporting agent homogeneously distributed in an insulating binder an azine which has the general structural formula ##STR28## wherein R.sub.5 to R.sub.10 each represents a hydrogen atom or an alkyl group having 1 to 4 C atoms.
A multi-layered electrophotographic element comprising an electrically conductive support in the form of a drum or of a flexible web to be made endless for use, on said support a photo-conductive layer of 0.2 to 2 .mu.m in thickness consisting essentially of at least one radiation-sensitive charge generating bis-azo compound homogeneously distributed in a polymeric binder, and on said photoconductive layer a charge transporting layer consisting essentially of an inert polymeric binder having homogeneously distributed therein about 20 to 40% by weight of 4-[bis(4-methylphenyl)amino] benzaldehyde azine and an activator for said azine.
Dependencies are inferred from the claim text.