US Patent 11714359 Electrophotographic photosensitive member, process cartridge, and image forming apparatus

An electrophotographic photosensitive member includes: a conductive support; a charge generation layer disposed on the conductive support, the charge generation layer including a charge generating material and a vinyl copolymer, the vinyl copolymer including a structural unit including a chlorine atom, a structural unit including an acyloxy group, and a structural unit including an aromatic polycarboxylic acid structure, a proportion of the structural unit including a chlorine atom to all the structural units being 80% by mass or more, a proportion of the structural unit including an aromatic polycarboxylic acid structure to all the structural units being 0.5% by mass or more; and a charge transport layer disposed on the charge generation layer, the charge transport layer including a charge transporting material and a binder resin.