| 摘要 |
PURPOSE:To effectively obtain an electrostatic image developing toner causing low fog at a small cost of power, by preliminarily pulverizing a roughly crushed toner material with an impact breaker, and finely pulverizing it with a jet mill. CONSTITUTION:A raw toner material consisting of synthetic resin, carbon black, etc. is roughly crushed with a hammer mill, etc., and preliminarily pulverized with an impact breaker having a rotor 2 provided with beater blades 2a so as to make weight average particle diameter not to exceed 50mum. Then, it is further micropulverized by beating the pulverized particles 1 with ultrahigh speed air streams injected from a jet nozzle 4 using a jet pulverizer, thus permitting both advantages of the impact and jet pulverizers to be adopted, microparticles causing fog to be prevented, and an intended electrostatic image developing toner to be effectively obtained. |
