Developing member, process cartridge, and electrophotographic apparatus

• US 8,706,011 B2
• Filed: 06/21/2013
• Issued: 04/22/2014
• Est. Priority Date: 02/17/2012
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Anan, Genya, Yamada, Masaki, Sakurai, Yuji, Ishii, Toru
• Primary Examiner(s): Lindsay, Jr., Walter L
• Assistant Examiner(s): Wenderoth, Frederick
• Application Number:
  US13/923,714
• Publication Number:
  US 20130287454A1
• Time in Patent Office: 305 Days
• Field of Search: 399/286
• US Class Current: 399/286
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/42 Polycondensates having carboxylic or carbonic ester groups in the main chain
• CPC Class Codes: C08G 18/48 Polyethers
• CPC Class Codes: C08G 18/4825 Polyethers containing two hydroxy groups C08G18/4833 - C08G18/5096 take precedence
• CPC Class Codes: C08G 18/4854 Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
• CPC Class Codes: G03G 15/0818 characterised by the structure of the donor member, e.g. surface properties

Abstract

Provided is a developing member capable of exerting stable performance under various environments. The developing member comprises a mandrel, an elastic layer formed on a periphery of the mandrel, and a surface layer covering a peripheral surface of the elastic layer. The surface layer contains a polyurethane and zinc oxide particles dispersed in the polyurethane, and the polyurethane has, between two adjacent urethane bonds, one or both of structures selected from structures according to the following item (A) and the following item (B): (A) a structure represented by the following structural formula (1), and one or both of structures selected from a structure represented by the following structural formula (2) and a structure represented by the following structural formula (3); and (B) a structure represented by the following structural formula (4).

Claims

1. A developing member, comprising:

a mandrel;

an elastic layer formed on a periphery of the mandrel; and

a surface layer covering a peripheral surface of the elastic layer,

wherein;

the surface layer contains

a polyurethane and

zinc oxide particles dispersed in the polyurethane; and

the polyurethane has, between two adjacent urethane bonds, one or both of structures selected from structures according to the following item (A) and the following item (B);

(A) a structure represented by the following structural formula (1), and one or both of structures selected from a structure represented by the following structural formula (2) and a structure represented by the following structural formula (3); and

2. The developing member according to claim 1, wherein a ratio between the number of moles of the structure represented by the structural formula (1), and a total sum of the number of moles of the structure represented by the structural formula (2) and the number of moles of the structure represented by the structural formula (3) in the polyurethane is 50:

50 to 80;

20.

3. The developing member according to claim 1, wherein the zinc oxide particles have an average primary particle diameter of 20 to 600 nm.

4. The developing member according to claim 3, wherein the zinc oxide particles comprise zinc oxide particles having an average primary particle diameter of 20 to 50 nm.

5. The developing member according to claim 4, wherein a content of the zinc oxide particles in the surface layer is 23 to 46 parts by mass with respect to 100.0 parts by mass of a resin solid content in the surface layer.

6. The developing member according to claim 3, wherein the zinc oxide particles comprise zinc oxide particles having an average primary particle diameter of 50 to 100 nm.

7. The developing member according to claim 6, wherein a content of the zinc oxide particles in the surface layer is 10 to 60 parts by mass with respect to 100.0 parts by mass of a resin solid content in the surface layer.

8. The developing member according to claim 3, wherein the zinc oxide particles comprise zinc oxide particles having an average primary particle diameter of 100 to 600 nm.

9. The developing member according to claim 8, wherein a content of the zinc oxide particles in the surface layer is 10 to 46 parts by mass with respect to 100.0 parts by mass of a resin solid content in the surface layer.

10. The developing member according to claim 1, wherein the polyurethane comprises a polyurethane obtained by causing a polyol having at least one of the structures according to the item (A) and the item (B), and an isocyanate compound to react with each other.

11. The developing member according to claim 1, wherein the elastic layer contains a silicone rubber.

12. An electrophotographic apparatus, comprising:

the developing member according to claims 1; and

an electrophotographic photosensitive member placed to be in contact with or close to the developing member.

13. A process cartridge, comprising:

the developing member according to claim 1; and

an electrophotographic photosensitive member placed to be in contact with or close to the developing member,

wherein the process cartridge is detachably mountable to a main body of an electrophotographic apparatus.