Imaging member having first and second charge transport layers
View Patent ↗A photoconductive imaging member containing an optional supporting substrate, an optional hole blocking layer thereover, a photogenerating layer and a charge transport layer, and wherein the charge transport layer contains a phenol of, for example, the alternative formulas
1. A photoconductive imaging member comprised of
a supporting substrate,
an optional hole blocking layer thereover,
a photogenerating layer,
a first charge transport layer in contiguous contact with the photogenerating layer, the first charge transport layer consisting of a charge transport compound and a polymer binder, and
a second charge transport layer coated over the first charge transport layer, the second charge transport layer consisting of a charge transport compound, a polymer binder, and a hindered phenol of the formula
wherein the total thickness of the two charge transport layers is about 29 microns, and the first and second transport layers are of equal thickness.
2. An imaging member in accordance with claim 1 wherein said hindered phenol is present in an amount of from about 1 to about 10 weight percent.
3. An imaging member in accordance with claim 1 wherein said hindered phenol is present in an amount of from about 0.5 to about 7 weight percent.
4. An imaging member in accordance with claim 1 wherein said hindered phenol is present in an amount of from about 1 to about 4 weight percent.
5. An imaging member in accordance with claim 1 wherein said hindered phenol is present in an amount of from about 0.5 to about 2 weight percent.
6. An imaging member in accordance with claim 1 further including a hole blocking layer.
7. An imaging member in accordance with claim 6 wherein said hole blocking layer is comprised of titanium oxide and a phenolic resin.
8. An imaging member in accordance with claim 1 comprised in the following sequence of said supporting substrate, said hole blocking layer, an optional adhesive layer, said photogenerating layer, said first charge transport layer, and said second charge transport layer.
9. An imaging member in accordance with claim 8 wherein the adhesive layer is present, and which layer is comprised of a polyester optionally with an M w of from about 50,000 to about 75,000, and an M n of about 25,000 to about 45,000.
10. An imaging member in accordance with claim 1 wherein the supporting substrate is comprised of a conductive metal substrate.
11. An imaging member in accordance with claim 10 wherein the conductive substrate is aluminum, aluminized polyethylene terephthalate or titanized polyethylene terephthalate.
12. An imaging member in accordance with claim 1 wherein said photogenerating layer is of a thickness of from about 0.05 to about 10 microns.
13. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of photogenerating pigments dispersed in a polymer, and which pigments are present in an amount of from about 5 percent by weight to about 95 percent by weight.
14. An imaging member in accordance with claim 1 wherein the charge transport compound in each of the first and second charge transport layers is independently an aryl amine molecule.
15. An imaging member in accordance with claim 14 wherein the aryl amine is of the formula
wherein X is selected from the group consisting of alkyl and halogen, and optionally wherein the aryl amine is dispersed in a resinous binder.
16. An imaging member in accordance with claim 15 wherein the aryl amine is N,N′-diphenyl-N,N-bis(3-methyl phenyl)-1,1′-biphenyl-4,4′-diamine.
17. An imaging member in accordance with claim 1 further including an adhesive layer of a polyester with an M w of from about 35,000 to about 70,000, and an M n of from about 25,000 to about 41,000.
18. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of metal phthalocyanines or metal free phthalocyanines.
19. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of titanyl phthalocyanines, perylenes, or hydroxygallium phthalocyanines.
20. An imaging member in accordance with claim 1 wherein the photogenerating layer is comprised of Type V hydroxygallium phthalocyanine.
21. 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.
22. A member in accordance with claim 1 , and which member is flexible.
23. A member in accordance with claim 1 , and which member is rigid.