BINDER RESIN FOR TONER, ELECTROSTATIC CHARGE IMAGE DEVELOPING TONER AND IMAGE FORMING METHOD

PROBLEM TO BE SOLVED: To enhance stable production without causing bridging in manufactur ing the toner by incorporating free acid groups in the structure of the binder resin and mixing an oil components. SOLUTION: The toner is made by mixing and kneading the binder resin having the free acid groups and containing the oil component, and a colorant, and when needed, other components. The binder resin containing the oil component is obtained by polymerizing the monomer of the resin in the presence of a silicone oil as the oil component. The binder resin for the toner is embodied by a vinyl resin having acid groups and a polyester resin and a mixture of these resins, and the vinyl resin having acid groups is made by copolymerizing one or more kinds of vinyl monomers with a monomer having a polymerizable unsaturated double bond and at least one carboxylic group.