Electrophotographic photoreceptor, electrophotographic photoreceptor cartridge and image forming apparatus

摘要

An electrophotographic photoreceptor, an electrophotographic photoreceptor cartridge, and an image forming apparatus, which are excellent in electrical characteristics such as a responsivity and at the same time, excellent in the crack resistance, are provided. Two kinds of charge transport substances each having a specific structure and a polycarbonate resin having a specific structure are combined, whereby the electrical characteristics such as responsivity and the crack resistance can be improved at the same time.

主权项

1. An electrophotographic photoreceptor, comprising a conductive support, a charge transport layer, and a charge generation layer on the conductive support, wherein the charge transport layer comprises:
a charge transport substance represented by the following formula (2): a charge transport substance represented by the following formula (6): a polycarbonate resin having a structural unit represented by the following formula (5) as a binder resin: wherein: and the first and second charge transport substances and the polycarbonate resin are present in the same layer; each of Ar4 to Ar7 independently represents an optionally-substituted aryl group having a carbon number of 30 or less; X represents a divalent substituent represented by the formula (3); each of R1 and R2 independently represents a hydrogen atom or an alkyl group having a carbon number of 6 or less, provided that when X is the divalent substituent represented by the formula (3), each of Ar4 and Ar6 is independently an optionally-substituted phenyl group and each of Ar5 and Ar7 is independently an optionally-substituted naphthyl group; each of Ar8 and Ar9 independently represents an optionally-substituted aryl group having a carbon number of 30 or less; each of R8 and R9 independently represents a hydrogen atom or an alkyl group having a carbon number of 6 or less; each of R6 and R7 represents a hydrogen atom or an alkyl group having a carbon number of 4 or less; and Z represents a cyclic aliphatic alkyl group having a total carbon number of 5 to 9 including the carbon atom of the bonding site, wherein the total amount of the charge transport substance represented by the formula (6) and the charge transport substance represented by the formula (2), in terms of weight per 100 parts by weight of the binder resin, is from 70 to 110 parts, and wherein a mixing ratio of the charge transport substance represented by the formula (6) and the charge transport substance represented by the formula (2) is from 40:60 to 90:10.