IP Library Granted Patent US 9,029,061
Granted Patent B2
US 9,029,061 · App. 12/978,920 · Granted May 12, 2015

Carrier, developer using the carrier, and developing device, image forming method, image forming apparatus and process cartridge using the developer

Inventors: Koichi Sakata (Shizuoka-ken, JP); Minoru Masuda (Shizuoka-ken, JP); Hisashi Nakajima (Shizuoka-ken, JP); Kimitoshi Yamaguchi (Shizuoka-ken, JP); Yutaka Takahashi (Kanagawa-ken, JP); Hitoshi Iwatsuki (Shizuoka-ken, JP); Saori Yamada (Shizuoka-ken, JP); Toyoaki Tano (Shizuoka-ken, JP)
Assignee: Ricoh Company, Limited
G03G9/1139G03G13/06G03G13/08G03G9/10G03G9/1136
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 9,029,061
App. No.
12/978,920
Granted
May 12, 2015
Kind
B2
Abstract

A carrier for use in a two component developer for developing an electrostatic latent image is provided. The carrier includes a particulate core material; and a cover layer located on a surface of the core material and including a silicone resin and barium sulfate. The cover layer includes Ba and Si at an atomic ratio of from 0.01 to 0.08 as determined by X-ray photoelectron spectroscopy.

Claims (15)

1. A carrier for use in a two component developer for developing an electrostatic latent image, comprising:

a particulate core material; and

a cover layer located on a surface of the core material and including a silicone resin and barium sulfate, wherein the cover layer includes Ba and Si at an atomic ratio of from 0.01 to 0.08 as determined by X-ray photoelectron spectroscopy.

2. The carrier according to claim 1 , wherein the cover layer further includes tin oxide.

3. The carrier according to claim 1 , wherein the carrier has a logarithmic volume resistivity of from 10 log(Ω·cm) to 15 log(Ω·cm).

4. The carrier according to claim 1 , wherein the carrier has a volume average particle diameter of from 15 μm to 40 μm.

5. A two component developer for developing an electrostatic latent image, comprising:

the carrier according to claim 1 ; and

a toner including at least a binder resin and a colorant.

6. The two component developer according to claim 5 , used as a supplementary developer, wherein a weight ratio (C/T) of the carrier (C) to the toner (T) is from ½ to 1/50.

7. An image forming method comprising:

forming an electrostatic latent image on an image bearing member;

developing the electrostatic latent image with the two component developer according to claim 5 to form a toner image on the image bearing member;

transferring the toner image to a recording material; and

fixing the toner image to the recording material.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 27, 2010
From: SAKATA, KOICHI; MASUDA, MINORU; NAKAJIMA, HISASHI; YAMAGUCHI, KIMITOSHI; TAKAHASHI, YUTAKA; IWATSUKI, HITOSHI; YAMADA, SAORI; TANO, TOYOAKI
To: RICOH COMPANY LIMITED
Reel/Frame 025538/0680 →
Priority Claims (1)
JP 2010-005096 · Jan 13, 2010 · national
Continuity (1)
Related Publication 20110171573A1 · Jul 14, 2011