Patent ID: 7005222

Claim:
An imaging member comprising a supporting substrate, an optional electrically conductive layer, an optional hole blocking layer, a charge generating layer, a dual charge transport layer having a first charge transport layer and a second charge transport layer on top of and in contiguous contact with the first charge transport layer, wherein the first charge transport layer is situated between the charge generating layer and the second charge transport layer, and each charge transport layer independently comprises, a film forming polymer binder and a hole transport compound molecularly dispersed therein, wherein the hole transport compound is selected from the group consisting of triphenylmethane; bis(4-diethyamino-2-methylphenyl) phenylmethane; 4,4′-bis(diethylamino)-2,2′-dimethyltriphenylmethane; N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine; N,N′-diphenyl-N,N′-bis(4-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine; N,N′-diphenyl-N,N′-bis (alkylphenyl)-1,1′-biphenyl-4,4′-diamine; N,N′-diphenyl-N,N′-bis(chlorophenyl)-1,1′-biphenyl-4,4′-diamine; tritolylamine; N,N′-bis-(3,4-dimethylphenyl)-4-biphenyl amine; N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-1,1′,3,3′-(dimethylbiphenyl)-4,4′-diamine; phenanthrene diamine; arylamine; enamine; stylbene; and hydrozone molecules, and the film forming polymer binder is selected from the group consisting of polycarbonates, polystyrene, polyesters, polyvinyl butyrals, polystyrene-b-polyvinyl pyridine, poly(vinyl butyral), poly(vinyl carbazole), poly(vinyl chloride), polyacrylates, polymethacrylates, copolymers of vinyl chloride and vinyl acetate, phenoxy resins, polyurethanes, poly(vinyl alcohol), and polyacrylonitrile; and wherein the first charge transport layer comprises between about 40 and about 80 weight percent of the hole transport compound based on the total weight of the first charge transport layer and wherein the second charge transport layer comprises a lesser amount by weight of the hole transport compound.