GB1500310A - Photoconductive materials - Google Patents

Abstract

1500310 Electro-photographic members EASTMAN KODAK CO 18 Dec 1975 [20 Dec 1974] 51897/75 Heading G2C An electro-photographic member contains two photo-conductive layers, one layer comprising a continuous polymer phase and a discontinuous phase of a cocrystalline complex of a polymer containing alkylidene diarylene groups and a pyrylium, thiapyrylium or selenapyrylium dye salt and being capable of generating charges and the other layer containing an organic photo-conductor but no cocrystalline complex and being capable of transporting charges. Preferably the complex layer is sensitive to 520-700 n.m. and the organic photoconductive layer is not sensitive to this range. Specified organic photo-conductors are tri-ptolylamine, polyvinyl carbazole/trinitrofluorenone (PV.K/TNF) complex, bis-(4 diethylamino) tetraphenylmethane and triphenyl methanes. An organic photo-conductor may be added to the continuous phase of the complex layer, preferably the same as that added to the charge transport layer. Preferably, the complex layer is coated on a polyester support with a Ni layer subbed with a vinylidenechloride copolymer and then overcoated with a thicker, organic photo-conductive layer. However, for positive charging, the photoconductive layers are coated in the reverse order. If visibly opaque organic photo-conductors are used (e.g. PVK/TNF), the member is exposed through the transparent support if the complex is the lower photo-conductive layer. The materials show a greater activity in the 600-680 n.m. range than single layer, materials of the cocrystalline complex. Other subbing layers and supports may be used.