IP Library Granted Patent US 8,437,663
Granted Patent B2
US 8,437,663 · App. 12/534,981 · Granted May 7, 2013

Charging member, process cartridge and image forming apparatus

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Quick Facts
Patent No.
US 8,437,663
App. No.
12/534,981
Granted
May 7, 2013
Kind
B2
Abstract

The present invention provides a charging member that includes at least: a base material; and a conductive outermost layer that is disposed on the base material, comes into contact with a body to be charged, has a ten-point average surface roughness Rz of about 2 μm to about 20 μm, and contains (A) a resin and (B) specific conductive particles for forming the surface roughness, the charging member coming into contact with the body to be charged, in a state where a voltage is applied, to charge the body to be charged.

Claims (32)

1. A charging member comprising at least:

a base material; and

a conductive outermost layer that is disposed on the base material, comes into contact with a body to be charged, has a ten-point average surface roughness Rz of about 2 μm to about 20 μm, and comprises (A) a resin and (B) specific conductive particles for forming the surface roughness,

the charging member coming into contact with the body to be charged, in a state where a voltage is applied, to charge the body to be charged, wherein

the (A) resin comprises a polyamide resin,

a gel fraction of the conductive outermost layer is 50% or more,

a volume average particle diameter of the (B) specific conductive particles is in a range of from about 2 μm to about 20 μm, and

the conductive outermost layer further comprises conductive particles (C) having an average particle diameter of from 1 nm to 200 nm.

2. The charging member of claim 1 , wherein an average degree of circularity of the (B) specific conductive particles is about 0.8 to about 1.0.

3. The charging member of claim 1 , wherein a specific gravity of the (B) specific conductive particles is about 2 g/cm 3 or less.

4. The charging member of claim 1 , wherein the (B) specific conductive particles are particles selected from the group consisting of amorphous carbon fine particles, carbon fine particles and graphite fine particles.

5. The charging member of claim 1 , wherein the polyamide resin is methoxymethylated polyamide.

6. A process cartridge comprising at least:

an image holding member; and

the charging member of claim 1 , which comes into contact with the image holding member.

7. The process cartridge of claim 6 , wherein an average degree of circularity of the (B) specific conductive particles is about 0.8 to about 1.0.

8. The process cartridge of claim 6 , wherein a specific gravity of the (B) specific conductive particles is about 2 g/cm 3 or less.

9. An image forming apparatus comprising:

an image holding member;

the charging member of claim 1 disposed so as to come into contact with the image holding member to charge the image holding member;

an exposing unit that forms an electrostatic latent image on the charged image holding member;

a developing unit that develops the electrostatic latent image formed on the image holding member with a toner to form a toner image; and

a transferring unit that transfers the toner image onto a transfer receiving body.

10. The image forming apparatus of claim 9 , wherein an average degree of circularity of the (B) specific conductive particles is about 0.8 to about 1.0.

11. The image forming apparatus of claim 9 , wherein a specific gravity of the (B) specific conductive particles is about 2 g/cm 3 or less.

12. A charging roll comprising at least:

a base material; and

a conductive outermost layer that is disposed on the base material, comes into contact with a body to be charged, has a ten-point average surface roughness Rz of about 2 μm to about 20 μm, and comprises (A) a resin formed by crosslinking N-alkoxymethylated polyamide using a catalyst and (B) specific conductive particles for forming the surface roughness,

the charging member coming into contact with the body to be charged, in a state where a voltage is applied, to charge the body to be charged, wherein

a gel fraction of the conductive outermost layer is 50% or more,

a volume average particle diameter of the (B) specific conductive particles is in a range of from about 2 μm to about 20 μm, and

the conductive outermost layer further comprises conductive particles (C) having an average particle diameter of from 1 nm to 200 nm.

Assignments (2)
CHANGE OF NAME Recorded Aug 12, 2021
From: FUJI XEROX CO., LTD.
To: FUJIFILM BUSINESS INNOVATION CORP.
Reel/Frame 058287/0056 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 4, 2009
From: HOSHIO, TAKURO
To: FUJI XEROX CO., LTD.
Reel/Frame 023051/0918 →