Electrophotographic material contg. charge-transfer agent - which is 6,8-di:nitro-4H-indeno-(1,2-b)-thiophenone-4 or its derivs., giving high speed

摘要

Electrophotographic material has a light-sensitive layer contg. a charge-producing pigment, a binder, and 6,8-dinitro-4H-indeno-(1,2-b)-thiophen-4-one of formula (I): (in which X is H or halogen. R is H or nitro), or its derivs. or one layer contg. a charge-producing substance and another layer contg. a binder and (I). The binder is pref. a polyamide, polyester, polyurethane, polystyrene, polycarbonate, polyvinylformal, polyvinylacetal, polyvinylbutyral, ethylcellulose, nitrocellulose, acetylcellulose, epoxy, alkyd, acrylic, silicone resin, and/or poly-N-vinylcarbazole. (I) acts as charge-transporting agent and the material has high sensitivity and durability. In an example, material with a Diane Blue (CI 21180) coating and a polycarbonate coating contg. 2-bromo-6,8-dinitro-4H-indeno-(1,2-b)-thiophen-4-one (Ia) was charged positively to 630 V and required a 25 lx-s exposure to halve this voltage. If (Ia) was omitted, no photodischarge occurred.