Patent ID: 7763409

Claim:
A method for producing a binder resin for a toner consisting of a tetrahydrofuran (THF) soluble portion and a THF-insoluble portion, wherein the entire resin in the bulk state is swollen when the resin in the bulk state is immersed in THF, said method comprising a step of subjecting an amorphous resin (X) having the amount of monomer having a carboxyl group of not less than 8 weight % based on the total amount of monomers and a peak molecular weight of not less than 20,000, an amorphous resin (Y) having the amount of monomer having a carboxyl group of less than 5 weight % based on the total amount of monomers and a peak molecular weight of less than 10,000, and a crystalline resin (Z) having a hydroxyl group to melting, kneading and reaction, wherein the amorphous resins and the crystalline resin are incompatible with each other.