| 摘要 |
PROBLEM TO BE SOLVED: To provide nonmagnetic toner particles in which transfer characteristics are excellent, deterioration and wear of toner particle surfaces are hardly caused, environmental characteristics are provided, and therefore good-quality image characteristics are stably obtained from an initial period to a life end. SOLUTION: For a toner preform, a polyester resin which has a glass transition point of 50-65°C, is regulated in a molecular weight distribution by a GPC (Gel Permeation Chromatography) in details, and has an acid value of≤10 mgKOH/g is used as a binder resin and the wax having a melting point of 50-90°C is used. The toner host particles are formed by melt kneading and pulverizing a mixture composed of the binder resin, coloring matter and wax, then treating the mixture in a gaseous phase by the hot air of the temperature higher than the glass transition temperature of the binder resin and the melting point of the wax, to obtain the particles having the arithmetic average value of circularity of 0.73-0.84 and volume average grain size of≤11μm. Cerium oxide is added at need into an external additive. COPYRIGHT: (C)2004,JPO |
