Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus

• US 7,901,855 B2
• Filed: 12/17/2009
• Issued: 03/08/2011
• Est. Priority Date: 07/18/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ochi, Atsushi, Uematsu, Hiroki, Ogaki, Harunobu
• Primary Examiner(s): RoDee; Christopher
• Application Number:
  US12/640,466
• Publication Number:
  US 20100092209A1
• Time in Patent Office: 446 Days
• Field of Search: 430/58.2, 430/59.6, 399/159
• US Class Current: 430/58.2
• CPC Class Codes: G03G 5/056 Polyesters
• CPC Class Codes: G03G 5/0564 Polycarbonates
• CPC Class Codes: G03G 5/0578 Polycondensates comprising silicon atoms in the main chain
• CPC Class Codes: G03G 5/0592 Macromolecular compounds characterised by their structure or by their chemical properties, e.g. block polymers, reticulated polymers, molecular weight, acidity
• CPC Class Codes: G03G 5/061443 benzidine
• CPC Class Codes: G03G 5/06147 alkenylarylamine
• CPC Class Codes: G03G 5/061473 plural alkenyl groups linked directly to the same aryl group
• CPC Class Codes: G03G 5/14752 Polyesters
• CPC Class Codes: G03G 5/14773 Polycondensates comprising silicon atoms in the main chain
• CPC Class Codes: G03G 5/14791 Macromolecular compounds characterised by their structure, e.g. block polymers, reticulated polymers, or by their chemical properties, e.g. by molecular weight or acidity

Abstract

A charge transport layer serving as a surface layer of an electrophotographic photosensitive member contains a polyester resin having a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), as a binder resin; the content of a siloxane moiety of the polyester resin is not less than 5% by mass and not more than 30% by mass relative to the total mass of the polyester resin; and the content of the polyester resin in the charge transport layer is not less than 60% by mass relative to the total mass of the whole binder resin in the charge transport layer.

Claims

1. An electrophotographic photosensitive member comprising a support, a charge generation layer provided on the support and a charge transport layer containing a charge transporting material and a binder resin formed on the charge generation layer, the charge transport layer serving as a surface layer of the electrophotographic photosensitive member, wherein:

the charge transport layer contains a polyester resin having a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), as a binder resin;

the content of a siloxane moiety in the polyester resin is not less than 5% by mass and not more than 30% by mass relative to the total mass of the polyester resin,

the siloxane moiety is a structure represented by the following formula;

2. The electrophotographic photosensitive member according to claim 1, wherein the content of the siloxane moiety in the charge transport layer is not less than 5% by mass and not more than 30% by mass relative to the total mass of the whole binder resin in the charge transport layer.

3. The electrophotographic photosensitive member according to claim 1, wherein n in the formula (1) is 25 or more and 70 or less.

4. The electrophotographic photosensitive member according to claim 1, wherein the content of the siloxane moiety in the charge transport layer is not less than 10% by mass and not more than 25% by mass relative to the total mass of the whole binder resin in the charge transport layer.

5. The electrophotographic photosensitive member according to claim 1, wherein X¹ in the formula (1) is a structure represented by the following formula (3-12) or (3-13) and X² in the formula (2) is a structure represented by the following formula (3-12) or (3-13):

6. The electrophotographic photosensitive member according to claim 1, wherein the charge transport layer contains, as a charge transporting material, a compound represented by the following formula (4):

7. A process cartridge comprising an 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, wherein the electrophotographic photosensitive member and the at least one device are integrally supported and detachably mountable to a main body of an electrophotographic apparatus.

8. 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.