| US 7,553,598 B2 | ||
| Electrophotographic carrier, developer, developer container, process cartridge, image forming apparatus and image forming method | ||
| Kousuke Suzuki, Numazu (Japan); Tomio Kondoh, Numazu (Japan); Shinichiro Yagi, Numazu (Japan); and Hitoshi Iwatsuki, Numazu (Japan) | ||
| Assigned to Ricoh Company, Limited, Tokyo (Japan) | ||
| Filed on Mar. 20, 2006, as Appl. No. 11/378,424. | ||
| Claims priority of application No. 2005-079479 (JP), filed on Mar. 18, 2005; and application No. 2005-263363 (JP), filed on Sep. 12, 2005. | ||
| Prior Publication US 2006/0210906 A1, Sep. 21, 2006 | ||
| Int. Cl. G03G 9/113 (2006.01) | ||
| U.S. Cl. 430—111.35 [430/111.1; 430/111.31; 430/123.58] | 18 Claims |
| 1. A carrier, comprising:
a core; and
a cover layer located overlying the core,
wherein the cover layer comprises a binder resin, a first particulate material and a second particulate material,
wherein the following relationships are satisfied:
1<(D1/h) <10, and
0.001 <(D2/h) <1,
wherein D1 (μm) represents a volume average particle diameter of the first particulate material, D2 (μm) represents a volume
average particle diameter of the second particulate material, and h (μm) represents a thickness of the cover layer,
wherein the second particulate material has a volume resistivity of not greater than 1.0 ×1012 Ω·cm,
wherein the binder resin is a reaction product of an acrylic resin with amino resin, and wherein said amino resin is guanamine
or melamine.
|