Patent ID: 8227167
Filing Date: 2012-07-24
Classification: G03G

Abstract:
1. A method for producing a developing agent comprising: mixing a granular mixture containing a binder resin and a colorant, an aqueous medium and an alkaline pH controlling agent to prepare a toner material dispersion liquid; subjecting the toner material dispersion liquid to mechanical shearing under a temperature of a glass transition point Tg of the binder resin or more and a pressure of 10 MPa or more to make the granular mixture into fine particles to provide a dispersion liquid containing fine particles having a smaller particle diameter than a particle diameter of the granular mixture; depressurizing the dispersion liquid containing the fine particles with two or more stages while maintaining the temperature of a glass transition point Tg of the binder resin or more; and cooling the depressurized fine particle dispersion liquid to a temperature of a glass transition point Tg of the binder resin or less.