| 摘要 |
PURPOSE:To obtain a high-quality image when the toner is made into the smaller grain size by incorporating specific magnetite as magnetic material particles into the toner. CONSTITUTION:This toner contains a binder resin and the magnetite which is coated with a single-layer film of a surface active agent on the particle surface and has <=300Angstrom average grain size and the average grain size thereof is specified to <=8mum. The magnetite is uniformly dispersed into the toner particles essentially consisting of the binder resin and is capable of minimizing the formation of nonmagnetic particles even when the magnetite is used to form the small grain-size magnetic toner as small as <=8mum average grain size. The formation of the toner to the smaller grain size is thereby enabled and the high-quality image is obtd. |
