METHOD FOR MANUFACTURING ELECTROPHOTOGRAPHIC TONER BY KNEADING/PULVERIZING SYSTEM AND KNEADED MATERIAL USED FOR THE SAME

PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrophotographic toner by which the efficiency of pulverization of a kneaded material to be pulverized is enhanced and occurrence of ultrafine powder can be suppressed, with respect to a method for manufacturing an electrophotographic toner by a kneading/pulverizing system, and to provide an electrophotographic toner having a low ultrafine powder content. SOLUTION: The method for manufacturing an electrophotographic toner consisting essentially of a binder resin and a colorant by a kneading/pulverizing system includes the steps of uniformly dispersing a mixture consisting essentially of the binder resin and colorant by injecting a supercritical fluid into the mixture under pressure while melting and kneading the mixture; producing a kneaded material having bubbles by rapidly expanding the resulting liquid under reduced pressure and cooling it; and pulverizing the kneaded material. COPYRIGHT: (C)2005,JPO&NCIPI