Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus

• US 8,465,889 B2
• Filed: 01/29/2010
• Issued: 06/18/2013
• Est. Priority Date: 01/30/2009
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sekido, Kunihiko, Nagasaka, Hideaki, Sekiya, Michiyo, Takagi, Shinji, Maruyama, Akihiro
• Primary Examiner(s): RODEE, CHRISTOPHER D
• Application Number:
  US13/143,052
• Publication Number:
  US 20110268472A1
• Time in Patent Office: 1,236 Days
• Field of Search: 430/56, 430/96, 430/59.6, 430/64, 399/159
• US Class Current: 430/59.6
• CPC Class Codes: G03G 5/0571 Polyamides; Polyimides
• CPC Class Codes: G03G 5/0575 Other polycondensates comprising nitrogen atoms with or without oxygen atoms in the main chain
• CPC Class Codes: G03G 5/072 comprising pending monoamine groups

Abstract

To provide an electrophotographic photosensitive member that can reproduce good images with less positive ghost and also has a good photosensitivity, the electrophotographic photosensitive member is incorporated in its photosensitive layer with a copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (2), or a copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (3).
Z₁-A-Z₂-E₁  (1)
Z₃-A-Z₄—W₂—B₂—W₂  (2)
Z₅—B₃—Z₆-E₄  (3)

Claims

1. An electrophotographic photosensitive member comprising a support and a photosensitive layer formed on the support, wherein

the photosensitive layer contains a copolymer having a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), or a copolymer having a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (3):

Z₁-A-Z₂-E₁ 

 

(1)

Z₃-A-Z₄—

W₂—

B₂—

W₂ 

 

(2)

Z₅—

B₃—

Z₆-E₄ 

 

(3)

where, in the formulas (1), (2) and (3);

Z₁ to Z₆ each independently represent a single bond, an alkylene group, an arylene group, or an arylene group substituted with an alkyl group;

E₁ represents a divalent group represented by

—

W₁—

B₁—

W₁—

, or a divalent group represented by the following formula (E11);

2. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is a photosensitive layer having an electron transport layer, a charge generation layer and a hole transport layer which are layered in this order from the support side, and the electron transport layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (2) or the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (3).

3. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer is a photosensitive layer having an electron transport layer, a charge generation layer and a hole transport layer which are layered in this order from the support side, and the electron transport layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (2) or the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (3), in an amount of from 80% by mass to 100% by mass based on the total mass of the electron transport layer.

4. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (2), and the repeating structural unit represented by the formula (1) is in a proportion of from 50 mol % to 99 mol % based on all the repeating structural units in the copolymer.

5. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (2), and the repeating structural unit represented by the formula (1) is in a proportion of from 70 mol % to 99 mol % based on all the repeating structural units in the copolymer.

6. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (2), and the repeating structural unit represented by the formula (2) is in a proportion of from 1 mol % to 30 mol % based on all the repeating structural units in the copolymer.

7. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (3), and the repeating structural unit represented by the formula (1) is in a proportion of from 50 mol % to 99 mol % based on all the repeating structural units in the copolymer.

8. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (3), and the repeating structural unit represented by the formula (1) is in a proportion of from 70 mol % to 99 mol % based on all the repeating structural units in the copolymer.

9. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains the copolymer having a repeating structural unit represented by the formula (1) and a repeating structural unit represented by the formula (3), and the repeating structural unit represented by the formula (3) is in a proportion of from 1 mol % to 30 mol % based on all the repeating structural units in the copolymer.

10. A process cartridge which integrally supports the electrophotographic photosensitive member according to claim 1 and at least one device selected from the group consisting of a charging device, a developing device, a transfer device and a cleaning device, and is detachably mountable to the main body of an electrophotographic apparatus.

11. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging device, an exposure device, a developing device and a transfer device.