Patent ID: 7629098

Claim:
A method of producing a toner for developing an electrostatic charge image, the method comprising: aggregating particles containing a crystalline polyester resin, particles containing a non-crystalline polyester resin, and particles of a releasing agent in an aqueous medium, so as to form aggregated particles; and heating the aggregated particles to fuse into a coalescent body, wherein: at least one of the crystalline polyester resin and the non-crystalline polyester resin is obtained by polymerization at temperatures not higher than 150° C. with a Bronsted acid containing a sulfur atom as a catalyst, a first onset temperature A(° C.) of the toner and a glass transition temperature B(° C.) of the non-crystalline polyester resin as measured by differential scanning calorimeter satisfy a relation (B−A)≦10, the non-crystalline polyester resin has a weight average molecular weight (Mw) of from 5,000 to 100,000 as measured by a molecular weight measurement of a tetrahydrofuran (THF) soluble component utilizing gel permeation chromatography (GPC), and a weight average molecular weight of the crystalline polyester resin is ½ or lower of a weight average molecular weight of the non-crystalline polyester resin.