networked polyvinylbutyral binder for organic photoleiter

摘要

The invention is a self-cross-linked polyvinyl butyral (PVB) binder for OPC's. The non-cross-linked form of the binder is available from Monsanto Co. in the U.S.A. as Butvar TM , and from Sakisiu Chemical Co. in Japan as Slek TM . I discovered that the PVB may be self-cross-linked by subjecting it to just a thermal cure at between about 150 DEG -300 DEG C for about 2 hours. I think other ways of cross-linking, for example, L-beam, UV or X-ray radiation, will achieve results similar to those I obtained with heat. No cross-linker, nor cross-linkable copolymer nor catalyst is required to accomplish the cross-linking. After self-cross-linking, the PVB has good mechanical durability and good anti-solvent characteristics. In addition, the self-cross-linked PVB's glass transition temperature (Tg) increases from about 65 DEG C to about 170 DEG C. Also, when conventional photoconductor pigments are dispersed in the self-cross-linked PVB, they are well dispersed, and the resulting OPC's have good charge acceptance, low dark decay, and in general, good photodischarge characteristics. Also, OPC's with the self-cross-linked PVB exhibited improved adhesion, so multi-layered OPC's made according to this invention will have improved interlayer bonding and longer economic lives. IMAGE