| 摘要 |
PURPOSE:To obtain electric charge controlling resin particles narrow in size distribution and comparatively low in molecular weight by specifying the ranges of the average molecular weight of a copolymer of spherical particles obtained by suspension polymerization and the volume-based resin particles median diameter and the volume-based integrated diameter of the resin particles. CONSTITUTION:The charge controlling resin particles have a volume-based large median particle diameter of >= 3mum, a low weight average molecular weight of 3,000 - 50,000, and uniformly dissolves in a binder resin, such as a styrene copolymer, and in the monomer of sais resin, and it has a dispersion degree represented by a D25/D75 ratio in the range of 1 - 1.4, where D25 and D75 are volume-based integrated up to 25% and 75% particle diameters, respectively, thus permitting the obtained charge controlling resin particles to have a low molecular weight and a uniform size distribution and not to increase the viscosity of suspended oil drops and to uniformize the polarity of the drops, and accordingly, the toner particles sharp in size distribution to be obtained. |
