| 摘要 |
PURPOSE:To obtain a toner having a desirable grain size distribution at a good yield by discharging an aq. medium and polymerizable monomer compsn. under a specific pressure difference while whirling the medium and compsn. so as to generate vortex shearing flow. CONSTITUTION:A coloring agent, such as carbon black, a charge control agent, wax and others, such as toner characteristic improving agent, at need are added into the polymerizable monomer and these materials are uniformly mixed and dispersed by a wet process medium type grinding mill, such as attriter. A polymn. initiator is added to the polymerizable monomer compsn. obtd. in such a manner to form an oil phase and the oil phase is whirled under pressurization in the aq. medium in the presence of a dispersion stabilizer. The shearing force by the vortex flow is utilized. Namely, a continuous type dispersing machine utilizing the vortex flow or the vortex flow and cavitation is used under 30 to 200kg/cm<2>G pressurization. The improvement in the grain size distribution of the toner is made and the small-grain size toner having a sharp grain size distribution to be desired for upgrading of image quality is obtd. at a good yield. |
