| US 7,579,129 B2 | ||
| Process for preparing toner for electrophotography | ||
| Nobumichi Kamiyoshi, Wakayama (Japan); Koji Shimokusa, Wakayama (Japan); and Hiroyuki Kawaji, Wakayama (Japan) | ||
| Assigned to Kao Corporation, Tokyo (Japan) | ||
| Filed on May 25, 2005, as Appl. No. 11/136,370. | ||
| Claims priority of application No. 2004-167574 (JP), filed on Jun. 04, 2004. | ||
| Prior Publication US 2005/0271965 A1, Dec. 08, 2005 | ||
| Int. Cl. G03G 9/08 (2006.01) | ||
| U.S. Cl. 430—111.4 [430/109.4; 430/137.14] | 18 Claims |
| 1. A process for preparing a toner for electrophotography comprising a crystalline polyester and a colorant, comprising the
following:
(neutralizing step) neutralizing in a molten state a resin binder comprising a crystalline polyester having an acidic group;
(emulsifying step) contacting the neutralized resin binder in a molten state with an aqueous medium, to prepare a dispersion
comprising dispersed particles comprising the resin binder as a main component, the dispersed particles having an average
particle size of from 0.02 to 2 μm, wherein a rate of adding the aqueous medium from the beginning of the neutralization up
to the formation of an O/W dispersion is from 0.5 to 50 g/minute per 100 g of the resin binder;
(aggregating step) allowing the dispersed particles in the dispersion to aggregate to form aggregate particles comprising
at least the resin binder and the colorant as the constituents; and
(unifying step) unifying the aggregate particles,
wherein the colorant is added in at least one of the neutralizing step, the emulsifying step and the aggregating step,
and wherein the amount of the crystalline polyester in the resin binder is at least 80% by weight of the resin binder.
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