Manufacturing method for toner used in electrophotography

摘要

A novel manufacturing method for toner used in electrophotography employing no organic solvent is disclosed. The method comprises the steps of: (1) combing a colored melted resin (a) and an aqueous medium (b), wherein the colored melted resin (a) is prepared by heating and melting a kneaded material containing a synthetic resin for use in an electrophotographic toner having an ionic group and a coloring pigment, and the aqueous medium (b) contains a substance capable of neutralizing the ionic group, and possesses a raised temperature not lower than the softening point of the synthetic resin by way of heating with application of pressure where necessary; (2) dispersing the colored melted resin (a) in the aqueous medium (b) by mechanical means while maintaining a mixture of the colored melted resin (a) and the aqueous medium (b) at a temperature not lower than the softening point of the synthetic resin; (3) producing an aqueous suspension of colored resin microparticles by means of sudden cooling; (4) separating the colored resin microparticles from the suspension; and (5) drying the separated colored resin microparticles.