Photoconductive imaging members

1. A photoconductive imaging member comprised of a supporting substrate, a hole blocking layer thereover, a photogenerating layer, and a charge transport layer, and wherein the hole blocking layer is comprised of a metallic component and an electron transport component.

2. An imaging member in accordance with claim 1 wherein said metallic component is TiO 2 .

3. An imaging member in accordance with claim 2 wherein said metallic component is comprised of a metal containing dispersion of a titanium oxide, a silicon oxide, and a resin optionally present in an amount of from about 94 to about 98 weight percent.

4. An imaging member in accordance with claim 2 wherein said metallic component is comprised of a metal containing dispersion of a titanium oxide, a silicon oxide, and a resin present in an amount of from about 96 to about 98 weight percent.

5. An imaging member in accordance with claim 2 wherein said electron transport component is (4-n-butoxycarbonyl-9-fluorenylidene) malononitrile, 2-methylthioethyl 9-dicyanomethylenefluorene-4-carboxylate, 2-(3-thienyl)ethyl 9-dicyanomethylene fluorene-4-carboxylate, 2-phenylthioethyl 9-dicyanomethylenefluorene-4-carboxylate, 11,11,12,12-tetracyano anthraquinodimethane or 1,3-dimethyl-10-(dicyanomethylene)-anthrone.

6. An imaging member in accordance with claim 2 wherein said electron transport component is (4-n-butoxycarbonyl-9-fluorenylidene) malononitrile.

7. An imaging member in accordance with claim 1 wherein said metallic component is a metal oxide.

8. An imaging member in accordance with claim 1 wherein said metallic component is present in an amount of from about 20 to about 90 weight percent.

9. An imaging member in accordance with claim 1 wherein said metallic component is present in an amount of from about 30 to about 80 weight percent.

10. An imaging member in accordance with claim 1 wherein said electron transport component is N,N′-bis(1,2-dimethylpropyl)-1,4,5,8-naphthalenetetracarboxylic acid; bis(2-heptylimido)perinone; BCFM, butoxy carbonyl fluorenylidene malononitrile; benzophenone bisimide; or a substituted carboxybenzylnaphthaquinone.

11. An imaging member in accordance with claim 10 wherein said substituted carboxybenzylnaphthaquinone is substituted with alkyl.

12. An imaging member in accordance with claim 10 wherein said electron transport component is present in a dopant amount of from about 1 to about 15 weight percent.

13. An imaging member in accordance with claim 10 wherein said electron transport component is present in an amount of from about 2 to about 10 weight percent.

14. An imaging member in accordance with claim 10 wherein said electron transport component is present in an amount of from about 2 to about 4 weight percent.

15. An imaging member in accordance with claim 1 wherein said electron transport component is N,N′-bis(1,2-dimethylpropyl)-1,4,5,8-naphthalenetetracarboxylic acid.

16. An imaging member in accordance with claim 1 wherein said electron transport component is bis(2-heptylimido)perinone.

17. An imaging member in accordance with claim 1 wherein said electron transport component is a butoxy carbonyl fluorenylidene malononitrile.

18. An imaging member in accordance with claim 1 wherein said electron transport component is benzophenone.

19. An imaging member in accordance with claim 1 wherein said electron transport component is present in an amount of from about 1 to about 15 weight percent.

20. An imaging member in accordance with claim 1 wherein said electron transport component is selected in an amount of from about 2 to about 10 weight percent.

21. An imaging member in accordance with claim 1 wherein said electron transport component is selected in an amount of from about 2 to about 4 weight percent.

22. An imaging member in accordance with claim 1 wherein said hole blocking layer is of a thickness of about 2 to about 12 microns.

23. An imaging member in accordance with claim 1 wherein said electron transport component is (4-n-butoxycarbonyl-9-fluorenylidene) malononitrile (BCFM), 2-methylthioethyl 9-dicyanomethylenefluorene-4-carboxylate, 2-(3-thienyl)ethyl 9-dicyanomethylene fluorene-4-carboxylate, 2-phenylthioethyl 9-dicyanomethylenefluorene-4-carboxylate, 11,11,12,12-tetracyano anthraquinodimethane or 1,3-dimethyl-10-(dicyanomethylene)-anthrone.

24. An imaging member in accordance with claim 23 wherein the adhesive layer is comprised of a polyester with an M w of from about 45,000 to about 75,000, and an M n of from about 25,000 to about 40,000.

25. An imaging member in accordance with claim 1 wherein said electron transport component is (4-n-butoxycarbonyl-9-fluorenylidene) malononitrile.

26. An imaging member in accordance with claim 1 comprised in the following sequence of said supporting substrate, said hole blocking layer, an adhesive layer, said photogenerating layer, and said charge transport layer, and wherein said layer is a hole transport layer.

27. An imaging member in accordance with claim 1 wherein the supporting substrate is comprised of a conductive metal substrate, and optionally which substrate is aluminum, aluminized polyethylene terephthalate, or titanized polyethylene terephthalate.

28. An imaging member in accordance with claim 1 wherein said photogenerator layer is of a thickness of from about 0.05 to about 10 microns, and wherein said transport layer is of a thickness of from about 10 to about 50 microns.

29. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of photogenerating pigments dispersed in a resinous binder in an optional amount of from about 5 percent by weight to about 95 percent by weight, and optionally wherein the resinous binder is selected from the group consisting of polyesters, polyvinyl butyrals, polycarbonates, polystyrene-b-polyvinyl pyridine, and polyvinyl formals.

30. An imaging member in accordance with claim 1 wherein the charge transport layer comprises aryl amines, and which aryl amines are of the formula

wherein X is selected from the group consisting of alkyl and halogen.

31. An imaging member in accordance with claim 30 wherein alkyl contains from about 1 to about 10 carbon atoms, or wherein alkyl contains from 1 to about 5 carbon atoms, or optionally wherein alkyl is methyl, wherein halogen is chlorine, and wherein there is further included a resinous binder selected from the group consisting of polycarbonates and polystyrenes.

32. An imaging member in accordance with claim 30 wherein the aryl amine is N,N′-diphenyl-N,N-bis(3-methyl phenyl)-1,1′-biphenyl-4,4′-diamine.

33. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of metal phthalocyanines, hydroxygallium phthalocyanines, chlorogallium phthalocyanines, or metal free phthalocyanines.

34. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of titanyl phthalocyanines, perylenes, or halogallium phthalocyanines.

35. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of chlorogallium phthalocyanines.

36. A method of imaging which comprises generating an electrostatic latent image on the imaging member of claim 1 , developing the latent image, and transferring the developed electrostatic image to a suitable substrate.

37. An imaging member in accordance with claim 1 wherein said hole blocking layer is of a thickness of about 2 to about 4 microns.

38. An imaging member in accordance with claim 1 wherein said member comprises, in sequence, said supporting layer, said hole blocking layer, said photogenerating layer, and said charge transport, and wherein said charge transport is a hole transport; and wherein said hole blocking layer is comprised of an electron transport selected from the group consisting of N,N′-bis(1,2-dimethylpropyl)-1,4,5,8-naphthalenetetracarboxylic diimide represented by the formula

1,1′-dioxo-2-(4-methylphenyl)-6-phenyl-4-(dicyanomethylidene) thiopyran represented by the following structural formula

wherein R is independently selected from the group consisting of hydrogen, alkyl with 1 to about 4 carbon atoms, alkoxy and halogen, and a quinone selected from the group consisting of carboxybenzylnaphthaquinone represented by the formula

and tetra(t-butyl) diphenolquinone represented by the following structural formula

39. An imaging member in accordance with claim 1 wherein said metallic component is comprised of a particle dispersion of a titanium oxide (TiO 2 ), a silicon oxide (SiO 2 ), and a resin.

40. A photoconductive imaging member comprised of a hole blocking layer thereover, a photogenerating layer, and a charge transport layer, and wherein the hole blocking layer is comprised of a metallic component and an electron transport component.

41. An imaging member in accordance with claim 40 wherein said metallic component is a titanium oxide.

42. A xerographic apparatus comprised of charging component, an imaging component, a transfer component, a development component, and a fixing component; and wherein the imaging component is comprised of a photoconductive imaging member comprised of a supporting substrate, a hole blocking layer thereover, a photogenerating layer, and a charge transport layer, and wherein the hole blocking layer is comprised of a metallic component and an electron transport component.