| US 7,541,128 B2 | ||
| Toner, developer including the toner, and method for fixing toner image | ||
| Yohichiroh Watanabe, Fuji (Japan); Masanori Suzuki, Shizuoka-ken (Japan); Tsunemi Sugiyama, Numazu (Japan); Hiroshi Yamashita, Numazu (Japan); Takuya Saito, Numazu (Japan); Naohiro Watanabe, Shizuoka-ken (Japan); Masami Tomita, Numazu (Japan); Shigeru Emoto, Numazu (Japan); Shinichiro Yagi, Numazu (Japan); Hiroshi Yamada, Numazu (Japan); Toshiki Nanya, Mishima (Japan); and Tadao Takigawa, Shinshiro (Japan) | ||
| Assigned to Ricoh Company Limited, Tokyo (Japan) | ||
| Filed on Sep. 26, 2003, as Appl. No. 10/670,320. | ||
| Claims priority of application No. 2002-281900 (JP), filed on Sep. 26, 2002; application No. 2002-333251 (JP), filed on Nov. 18, 2002; and application No. 2002-365782 (JP), filed on Dec. 17, 2002. | ||
| Prior Publication US 2004/0131961 A1, Jul. 08, 2004 | ||
| Int. Cl. G03G 9/087 (2006.01) | ||
| U.S. Cl. 430—108.4 [430/108.1; 430/109.4; 430/123.51; 430/123.54; 430/124.32; 430/137.16; 430/137.19] | 9 Claims |
| 1. A toner composition, comprising:
toner particles comprising:
a binder resin comprising:
an urea-modified polyester resin; and
a second resin having a weight average molecular weight of from 2,000 to 10,000,
a colorant;
a release agent; and
a particulate material which is present in at least a surface portion of the toner particles while embedded into the surface
portion,
wherein the binder resin has a glass transition temperature not lower than 35° C. and lower than 55° C., and wherein the particulate
material has an average particle diameter of from 0.002 to 0.2 times that of the toner particles;
wherein the particulate material comprises a particulate resin having a glass transition temperature of from 55 to 100° C.;
wherein the particulate resin is crosslinked using a crosslinking agent;
wherein the binder resin comprises tetrahydrofuran-insoluble components in an amount of from 2 to 30% by weight; and wherein the toner particles are prepared by a method comprising
dissolving or dispersing a toner composition, comprising
(i) at least a polyester prepolymer (A) having an isocyanate group, and being capable of reacting with an active hydrogen;
(ii) an amine (B) as a compound having an active hydrogen,
(iii) said second resin having a weight average molecular weight of from 2,000 to 10,000,
(iv) said colorant, and
(v) said release agent, in an organic solvent, to obtain an oil phase liquid;
dispersing the oil phase liquid in an aqueous medium comprising said particulate material while subjecting the polyester prepolymer
(A) to an addition polymerization reaction using said compound having said active hydrogen as a cross-linking agent, extending
agent or both, to prepare said urea-modified polyester resin and to prepare a dispersion;
removing at least the organic solvent from the dispersion to prepare the toner particles comprising the binder resin;
washing the toner particles; and
drying the toner particles.
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