Overcoat for imaging members

• US 5,162,183 A
• Filed: 05/10/1991
• Issued: 11/10/1992
• Est. Priority Date: 07/31/1990
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Lindblad, Nero R., Schank, Richard L., Scharfe, Merlin E., Melnyk, Andrew R., Trott, Robert E., Leising, Walter F., Bigelow, Richard W., Relyea, Herbert C.
• Primary Examiner(s): MARTIN, ROLAND E
• Application Number:
  US07/698,215
• Time in Patent Office: 550 Days
• Field of Search: 430/58, 430/59, 430/66, 430/67, 430/132
• US Class Current: 430/58.8
• CPC Class Codes: G03G 5/0525 Coating methods
• CPC Class Codes: G03G 5/147 Cover layers

Abstract

A surface layer on an imaging member has a surface roughness which reduces the force necessary for blade cleaning, reduces blade edge truck, reduces blade/substrate friction, inhibits the formation of toner-type deposits on the imaging surface, and/or reduces or eliminates light interference patterns resulting from coherent light, for example, from a raster output scanner.

Claims

1. An imaging member comprising at least one photosensitive layer and an overcoat layer formed from a solution having a surface roughness defined by asperities formed by circulation patterns formed in the layer during drying, wherein said surface roughness comprises a lateral roughness of between about 1 micrometer and about 200 micrometers, and a vertical roughness less than or equal to about 1 micrometer.

2. The imaging member of claim 1, wherein said surface roughness comprises a lateral roughness of about 50 micrometers to about 150 micrometers and a vertical roughness of about 0.1 micrometer to about 0.3 micrometer.

3. The imaging member of claim 2, wherein said surface roughness is accompanied by a fine scale roughness comprised of a lateral roughness of about 1 micrometer to about 10 micrometers and a vertical roughness of about 0.2 micrometer to about 0.3 micrometer.

4. The imaging member of claim 1, wherein said surface roughness comprises a lateral roughness of about 5.0 micrometers to about 100.0 micrometers and a vertical roughness of about 0.2 micrometer to about 0.5 micrometer.

5. The imaging member of claim 1, wherein said overcoat layer comprises a charge transport compound which is a triaryl amine having hydroxy functionalities.

6. The imaging member of claim 1, wherein said overcoat layer comprises silicone.

7. The imaging member of claim 1, wherein said overcoat layer comprises an electron donor compound.

8. The imaging member of claim 1, comprising a supporting substrate, a conductive layer, a blocking layer, an adhesive layer, a charge generating layer, a charge transport layer, and said overcoat layer.

9. The imaging member of claim 1, wherein said overcoat layer comprises a charge transport compound and a binder which are bonded through hydrogen bonds.

10. An imaging member comprising a non-continuous overcoat layer, formed from a polymer solution, having a surface roughness defined by hemispheric dots of the layer formed during drying.

11. The imaging member of claim 10, wherein the surface roughness is comprised of a lateral roughness of about 5.0 to about 10.0 micrometers and a vertical roughness of about 0.2 to about 0.5 micrometer.

12. The imaging member of claim 10, wherein the dots are present in a concentration of about 10,000 to about 40,000 dots per square millimeter.

13. An imaging system, comprising:

an imaging member comprising an overcoat layer having a surface roughness defined by a vertical roughness less than or equal to about 1 micrometer and a lateral roughness of about 1 to about 200 micrometers; and

a blade contacting said overcoat layer.

14. The system of claim 13, further comprising a raster output scanner.

15. The system of claim 13, wherein the vertical roughness is about 0.1 micrometer to about 0.3 micrometer and the lateral roughness is about 50 micrometers to about micrometers.

16. The system of claim 13, wherein the vertical roughness is about 0.2 micrometer to about 0.5 micrometer and the lateral roughness is about 5.0 micrometers to about 100.0 micrometers.

17. An imaging system, comprising:

an imaging member comprising an overcoat layer having a surface roughness defined by a vertical roughness of about 0.2 to about 0.5 micrometer and a lateral roughness of about 5.0 to about 100.0 micrometers; and

a raster output scanner.

18. A method for fabricating an overcoat layer for an imaging member, comprising:

applying a coating solution to a surface of said imaging member to form an overcoat film; and

drying the overcoat film under such conditions that circulation patterns are formed in and become frozen into a surface of the result in dry overcoat layer.

19. The method of claim 18, wherein said drying is carried out at about 65°

-70°

F. and relative humidity of about 30 to about 40%.

20. The method of claim 18, wherein said drying is performed such that a surface roughness of the overcoat layer comprises a lateral roughness of about 1 micrometer to about 200 micrometers and a vertical roughness less than about 1.0 micrometer.

21. The method of claim 18, wherein said drying is performed such that a surface roughness of the overcoat layer comprises a lateral roughness of about 50 micrometers to about 150 micrometers and a vertical roughness of about 0.1 micrometer to about 0.3 micrometer.

22. The method of claim 21, wherein said surface roughness is accompanied by a fine scale roughness comprised of a lateral roughness of about 1 micrometer to about 10 micrometers and a vertical roughness of about 0.2 micrometer to about 0.3 micrometer.

23. The method of claim 18, wherein said drying is performed such that a surface roughness of the overcoat layer comprises a lateral roughness of about 5.0 to about 100.0 micrometers and a vertical roughness of about 0.2 to about 0.5 micrometer.

24. The method of claim 18, wherein said coating solution comprises a film forming binder, a charge transport compound, and a solvent.

25. The method of claim 24, wherein said charge transport compound is a triaryl amine.

26. A method of electrophotographic imaging, comprising:

scanning a photoreceptor having a textured surface with a raster output scanner to form a latent image on the photoreceptor, said textured surface acting as an anti-reflection layer of light from the raster output scanner;

applying toner particles to the latent image to develop the image;

transferring the developed image to a support member; and

fixing the transferred image on the support member;

wherein the textured surface has a lateral surface roughness of about 5.0 to about 100.0 micrometers, and a vertical roughness of about 0.2 to about 0.5 micrometer.

27. The method of claim 26, wherein said textured surface comprises a charge transport compound which is a triaryl amine having hydroxy functionalities.

28. The method of claim 26, wherein said textured surface is non-continuous.

29. The method of claim 26, wherein said textured surface is obtained by circulation patterns formed upon drying a solution used to form the textured surface.