Abstract: The invention relates to a double-layered electrophotographic photoreceptor comprising a conductive support, a carrier generation layer provided on the conductive support, and a carrier transport layer provided on the carrier generation layer. The carrier generation layer contains a generation material, which generates carrier upon absorption of light, and a compound having an epoxy group. The carrier transport layer contains a carrier transport material which transports the generated carrier. This photoreceptor has excellent pre-exposure properties and durability for repeated use.

Abstract: Disclosed is a double-layered type electrophotographic photoreceptor which comprises an electroconductive support and a carrier generation layer containing a pigment or a dye as a carrier generation material and a carrier transport layer which are provided on said support, wherein the carrier transport layer contains an organic low molecular weight carrier transport material, a binder resin, a hydroquinone compound represented by the following formula (II): ##STR1## wherein R.sup.7, R.sup.8, R.sup.9 and R.sup.10 each represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, a carbamoyl group or an alkylthio group, and a compound represented by the following formula (III): ##STR2## wherein R.sup.11, R.sup.12, R.sup.13 and R.sup.14 each represents a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group with a proviso that at least one of R.sup.11 -R.sup.14 is hydroxyl group, R.sup.15 and R.sup.

Abstract: The present invention provides an electro-photographic photoreceptor which is high in sensitivity and endurance which comprises an electroconductive support and, provided thereon, a photosensitive layer which contains a compound represented by the following formula [I]: ##STR1## wherein R.sup.1 and R.sup.2 each represents a hydrogen atom or an alkyl, aralkyl or aryl group which may have substituent: X represents ##STR2## in which R.sup.3 and R.sup.4 each represents an alkyl, aralkyl or aryl group which may have substituent and R.sup.5 and R.sup.6 each represents a hydrogen atom or an alkyl, aralkyl or aryl group which may have substituent and R.sup.5 and R.sup.6 may link to each other to form a ring; and Z represents a group of atoms necessary for forming a saturated 5-8 membered ring together with two carbon atoms of the indoline ring.