Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

• US 20030194625A1
• Filed: 12/09/2002
• Published: 10/16/2003
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yoshimura, Kimihiro, Tanaka, Daisuke, Ikezue, Tatsuya, Morikawa, Yosuke, Nakata, Kouichi
• Granted Patent: US 6,806,009 B2
• Time in Patent Office: Days
• US Class Current: 430/58.8
• CPC Class Codes: G03G 15/751 relating to drum G03G15/757 takes precedence
• CPC Class Codes: G03G 5/147 Cover layers

Abstract

In an electrophotographic photosensitive member comprising a cylindrical support, and provided thereon a photosensitive layer and a protective layer in this order, which cylindrical support has an outer diameter of less than 30 mm, the difference between a coefficient of thermal expansion α₁ measured from the top of the protective layer and a coefficient of thermal expansion α₂ measured after the protective layer has been removed, |α₁−α₂|, is more than 5.0×10⁻⁷° C.⁻¹ to less than 1.0×10⁻⁴° C.⁻¹, and the modulus of elastic deformation We % measured from the top of the protective layer is more than 30% to less than 60%. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.

Claims

1. An electrophotographic photosensitive member comprising a cylindrical support, and provided thereon a photosensitive layer and a protective layer in this order, which cylindrical support has an outer diameter of less than 30 mm, wherein;

the difference between a coefficient of thermal expansion α

₁ measured from the top of the protective layer and a coefficient of thermal expansion α

₂ measured after the protective layer has been removed, |α

₁−

α

₂|, is more than 5.0×

10<sup>−

7</sup>°

C.<sup>−

1</sup> to less than 1.0×

10<sup>−

4</sup>°

C.<sup>−

1</sup>; and

the modulus of elastic deformation We % measured from the top of the protective layer is more than 30% to less than 60%.

2. The electrophotographic photosensitive member according to claim 1, wherein said protective layer contains a binder resin and at least one of conductive particles and a charge-transporting material.

3. The electrophotographic photosensitive member according to claim 2, wherein said binder resin is a curable resin.

4. The electrophotographic photosensitive member according to claim 3, wherein said curable resin is selected from the group consisting of a phenolic resin, an epoxy resin and a siloxane resin.

5. The electrophotographic photosensitive member according to claim 4, wherein said curable resin is a phenolic resin, and the phenolic resin is a resol type phenolic resin.

6. The electrophotographic photosensitive member according to claim 5, wherein said resol type phenolic resin is a resin synthesized in the presence of an alkali catalyst selected from the group consisting of an alkali metal, an alkaline earth metal and an amine compound.

7. The electrophotographic photosensitive member according to claim 6, wherein said resol type phenolic resin is a resin synthesized in the presence of an amine compound.

8. The electrophotographic photosensitive member according to claim 4, wherein said curable resin is a phenolic resin, and the phenolic resin is a heat-curable phenolic resin.

9. The electrophotographic photosensitive member according to claim 1, wherein said protective layer contains at least conductive particles, and the conductive particles are metal particles or metal oxide particles.

10. The electrophotographic photosensitive member according to claim 1, wherein said protective layer contains at least one of a fluorine-atom-containing compound and a siloxane compound.

11. The electrophotographic photosensitive member according to claim 10, wherein said protective layer contains at least a fluorine-atom-containing compound, and the fluorine-atom-containing compound is a compound selected from the group consisting of a fluorine-containing silane coupling agent, a fluorine-modified silicone oil and a fluorine type surface-active agent.

12. The electrophotographic photosensitive member according to claim 10, wherein said protective layer contains at least a siloxane compound, and the siloxane compound is a siloxane compound having structure represented by the following Formula (1):

13. The electrophotographic photosensitive member according to claim 1, wherein said protective layer contains lubricating particles.

14. The electrophotographic photosensitive member according to claim 13, wherein said lubricating particles are particles selected from the group consisting of fluorine-atom-containing resin particles, silicone resin particles, silica particles and alumina particles.

15. The electrophotographic photosensitive member according to claim 1, wherein said protective layer contains at least a charge-transporting material, and the charge-transporting material has a hydroxyl group in the molecule.

16. The electrophotographic photosensitive member according to claim 15, wherein said charge-transporting material has at least one of a hydroxyalkyl group and a hydroxyalkoxyl group in the molecule.

17. The electrophotographic photosensitive member according to claim 16, wherein said charge-transporting material having at least one of a hydroxyalkyl group and a hydroxyalkoxyl group in the molecule has structure represented by any one of the following Formulas (2) to (4):

18. The electrophotographic photosensitive member according to claim 1, wherein said protective layer contains at least a charge-transporting material, and the charge-transporting material has a hydroxyphenyl group in the molecule.

19. The electrophotographic photosensitive member according to claim 18, wherein said charge-transporting material having a hydroxyphenyl group in the molecule has structure represented by any one of the following Formulas (5) to (7):

20. The electrophotographic photosensitive member according to claim 1, which is an electrophotographic photosensitive member used for an electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging means, an exposure means, a developing means and a transfer means;

said charging means being a contact charging means having a charging member provided in contact with said electrophotographic photosensitive member;

said charging member being a contact charging member to which only a direct-current voltage is applied to charge said electrophotographic photosensitive member electrostatically.

21. The electrophotographic photosensitive member according to claim 20, which is used for an electrophotographic apparatus and wherein;

said contact charging member is a member comprising i) charging particles for coming into contact with said electrophotographic photosensitive member and ii) a charging-particle-holding member having a surface which has conductivity and elasticity for holding thereon said charging particles;

said charging particles having a particle diameter of from 10 nm to 10 μ

m; and

said contact charging means is an injection charging means in which electric charges are directly injected to said electrophotographic photosensitive member surface by means of said charging particles to charge said electrophotographic photosensitive member electrostatically.

22. A process cartridge comprising an electrophotographic photosensitive member and a means selected from the group consisting of a charging means, a developing means, a transfer means and a cleaning means which are integrally supported, and being detachably mountable to the main body of an electrophotographic apparatus, wherein;

said electrophotographic photosensitive member comprises a cylindrical support, and provided thereon a photosensitive layer and a protective layer in this order, which cylindrical support has an outer diameter of less than 30 mm, wherein;

the difference between a coefficient of thermal expansion α

₁ measured from the top of the protective layer and a coefficient of thermal expansion α

₂ measured after the protective layer has been removed, |α

₁−

α

₂|, is more than 5.0×

10<sup>−

7</sup>°

C.<sup>−

1</sup> to less than 1.0×

10<sup>−

4</sup>°

C.<sup>−

1</sup>; and

the modulus of elastic deformation We % measured from the top of the protective layer is more than 30% to less than 60%.

23. The process cartridge according to claim 22, wherein said electrophotographic photosensitive member and said charging means at least are integrally supported, and said charging means is a contact charging means having a charging member provided in contact with said electrophotographic photosensitive member;

said charging member being a contact charging member to which only a direct-current voltage is applied to charge said electrophotographic photosensitive member electrostatically.

24. The process cartridge according to claim 22, wherein;

said contact charging member is a member comprising i) charging particles for coming into contact with said electrophotographic photosensitive member and ii) a charging-particle-holding member having a surface which has conductivity and elasticity for holding thereon said charging particles;

said charging particles having a particle diameter of from 10 nm to 10 μ

m; and

said contact charging means is an injection charging means in which electric charges are directly injected to the electrophotographic photosensitive member surface by means of said charging particles to charge said electrophotographic photosensitive member electrostatically.

25. An electrophotographic apparatus comprising an electrophotographic photosensitive member, a charging means, an exposure means, a developing means and a transfer means, wherein;

said electrophotographic photosensitive member comprises a cylindrical support, and provided thereon a photosensitive layer and a protective layer in this order, which cylindrical support has an outer diameter of less than 30 mm, wherein;

the difference between a coefficient of thermal expansion α

₁ measured from the top of the protective layer and a coefficient of thermal expansion α

₂ measured after the protective layer has been removed, |α

₁−

α

₂|, is more than 5.0×

10<sup>−

7</sup>°

C.<sup>−

1</sup> to less than 1.0×

10<sup>−

4</sup>°

C.<sup>−

1</sup>; and

the modulus of elastic deformation We % measured from the top of the protective layer is more than 30% to less than 60%.

26. The electrophotographic apparatus according to claim 25, wherein said charging means is a contact charging means having a charging member provided in contact with said electrophotographic photosensitive member;

said charging member being a contact charging member to which only a direct-current voltage is applied to charge said electrophotographic photosensitive member electrostatically.

27. The electrophotographic apparatus according to claim 25, wherein;

said contact charging member is a member comprising i) charging particles for coming into contact with said electrophotographic photosensitive member and ii) a charging-particle-holding member having a surface which has conductivity and elasticity for holding thereon said charging particles;

said charging particles having a particle diameter of from 10 nm to 10 μ

m; and

said contact charging means is an injection charging means in which electric charges are directly injected to the electrophotographic photosensitive member surface by means of said charging particles to charge said electrophotographic photosensitive member electrostatically.