POLYESTER RESIN FOR TONER, ITS PRODUCTION AND ELECTROPHOTOGRAPHIC TONER USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a resin for electrophotographic toner excellent in low temp. fixing property and off-set preventive effect. SOLUTION: The polyester resin for toner is obtained by allowing a linear polyester synthesized from polyoxypropylene bis-phenol A and a dicarboxylic acid to react with (1) a >=3-hydric alcohol and a dicarboxylic acid or (2) a >=3-carboxylic acid and a diol and contains <=5wt.% tetrahydrofuran(THF) insoluble portion. And the max. value (Mp) of the molecular weight of a THF soluble portion is controlled to 1-6×10<3> and the ratio (Mp)/(Mn) of (Mp) to the number average molecular weight (Mn) is controlled to 1-3.