Developing member, process cartridge, and electrophotographic image forming apparatus

• US 8,655,222 B2
• Filed: 06/17/2013
• Issued: 02/18/2014
• Est. Priority Date: 02/17/2012
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nakamura, Minoru, Urushihara, Shohei, Kawamura, Kunimasa, Yamada, Masaki, Koyanagi, Takashi
• Primary Examiner(s): Lindsay, Jr., Walter L
• Assistant Examiner(s): BOLDUC, DAVID J
• Application Number:
  US13/920,007
• Publication Number:
  US 20130279937A1
• Time in Patent Office: 246 Days
• Field of Search: 399/111, 399/286
• US Class Current: 399/111
• CPC Class Codes: G03G 15/0818 characterised by the structure of the donor member, e.g. surface properties
• CPC Class Codes: G03G 15/0865 Arrangements for supplying new developer

Abstract

Provided is a developing member capable of suppressing a variation in resistance even when exposed to a high-temperature, high-humidity environment for a long time period. The developing member comprises: a mandrel; an electro-conductive elastic layer provided on a periphery of the mandrel; and a surface layer provided on a surface of the elastic layer, wherein: the elastic layer contains a dimethyl silicone rubber and carbon black; and an amount α of a hydrogen atom bound to a silicon atom of the dimethyl silicone rubber, and an amount β of a hydrogen atom of methyl groups bound to a silicon atom of the dimethyl silicone rubber, satisfy a relationship of 2.5×10⁻⁵≦α/β≦1.0×10⁻⁴.

Claims

1. A developing member, comprising:

a mandrel;

an electro-conductive elastic layer provided on a periphery of the mandrel; and

a surface layer provided on a surface of the elastic layer,

wherein;

the elastic layer contains a dimethyl silicone rubber and carbon black; and

an amount α

of a hydrogen atom bound to a silicon atom of the dimethyl silicone rubber, and

an amount β

of a hydrogen atom of methyl group bound to a silicon atom of the dimethyl silicone rubber, satisfy a relationship of 2.5×

10<sup>−

5</sup>≦

α

/β

≦

1.0×

10<sup>−

4</sup>.

2. The developing member according to claim 1, wherein

the amount α

of the hydrogen atom bound to the silicon atom of the dimethyl silicone rubber, and

the amount β

of the hydrogen atom of the methyl group bound to the silicon atom of the dimethyl silicone rubber, satisfy a relationship of 3.0×

10<sup>−

5</sup>≦

α

/β

≦

6.0×

10<sup>−

5</sup>.

3. The developing member according to claim 1, wherein the dimethyl silicone rubber is a reaction product of a liquid silicone rubber containing a liquid dimethylpolysiloxane having, in a molecule thereof, two or more alkenyl groups bound to a silicon atom and a dimethylpolysiloxane having, in a molecule thereof, two or more hydrogen atoms bound to a silicon atom.

4. The developing member according to claim 1, wherein the surface layer contains a urethane resin.

5. A process cartridge, comprising the developing member according to claim 1, wherein the process cartridge is detachably mountable to a main body of an electrophotographic image forming apparatus.

6. An electrophotographic image forming apparatus, comprising:

an image-bearing member for bearing an electrostatic latent image;

a charging unit for primarily charging the image-bearing member;

an exposing unit for forming an electrostatic latent image on the primarily charged image-bearing member;

a developing unit for developing the electrostatic latent image with toner to form a toner image; and

a transferring unit for transferring the toner image onto a transfer material,

wherein the developing unit comprises the developing member according to claim 1.