| US 7,550,242 B2 | ||
| Toner, toner manufacturing method, developer, image forming apparatus, and process cartridge for the image forming apparatus | ||
| Tsuyoshi Nozaki, Ikeda (Japan); Chiyoshi Nozaki, Ohtsu (Japan); Minoru Nakamura, Takarazuka (Japan); Atsushi Yamamoto, Kawanishi (Japan); and Hideaki Yasunaga, Ibaraki (Japan) | ||
| Assigned to Ricoh Company Limited, Tokyo (Japan) | ||
| Filed on Mar. 10, 2006, as Appl. No. 11/372,186. | ||
| Claims priority of application No. 2005-069234 (JP), filed on Mar. 11, 2005; and application No. 2005-269690 (JP), filed on Sep. 16, 2005. | ||
| Prior Publication US 2006/0204882 A1, Sep. 14, 2006 | ||
| Int. Cl. G03G 9/093 (2006.01) | ||
| U.S. Cl. 430—110.2 [430/137.14; 399/159] | 26 Claims |
| 1. A toner, comprising:
a core comprising a colorant, a release agent and a binder resin (A); and
a shell comprising a binder resin (B), which is located overlying the core,
wherein the binder resin (A) comprises a resin having a polyester skeleton, the binder resin (B) comprises a vinyl copolymer
resin, and a weight ratio of the shell to the core is from 0.05 to 0.5, and wherein the toner has a volume average particle
diameter of from 3 to 8 μm;
wherein the shell comprising the binder resin (B) is formed by aggregating a particulate vinyl copolymer resin using an aggregation
agent; and
wherein the aggregation agent comprises Mg2+, and the toner has a fluorescent X-ray intensity of a peak specific to a Mg-Kα X-ray of from 3 to 30 Kcps.
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