NEGATIVE TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE AND METHOD FOR MANUFACTURING THE SAME

PROBLEM TO BE SOLVED: To provide a toner which is used for the method of nonmagnetic single-component development and which stably gives high-quality image characteristics from the initial stage to the life end and to provide a method for manufacturing the toner. SOLUTION: In the negative toner for developing an electrostatic charge image comprising at least a binder resin and a coloring agent, the binder resin is a polyester resin having each specified weight average molecular weight Mw , ratio Mw /Mn to the number average molecular weight Mn and peaks P1, P2 of the molecular weight in the molecular weight distribution by GPC, the amount of the high molecular weight component and the acid value of the resin. The method for manufacturing the toner is carried out by preliminarily preparing a pigment dispersion master batch by using a copolymer polyester of 2-mol adduct of bisphenol-A propylene oxide and fumaric acid or maleic acid, then mixing the batch with the binder resin and other toner materials, melting and kneading, and dispersing the coloring agent in the toner.