Patent ID: 7981583

Claim:
A binder resin for an electrostatic image developing toner, which is obtained by a polycondensation reaction of at least two polycarboxylic acids and at least one polyol, wherein the at least two polycarboxylic acids comprise at least one of a polycarboxylic acid represented by formula (1) and a polycarboxylic acid represented by formula (2) in an amount of from about 3 mol % to less than about 45 mol % based on a total amount of the at least two polycarboxylic acids, the binder resin comprises a catalyst-derived metal in an amount of from about 0 ppm to about 10 ppm, the binder resin comprises a Brønsted acid catalyst having a melting temperature that is different from melting temperatures of 60 mol % or more of a total of polycarboxylic acids and polyol by less than about 100° C., and the binder resin has a glass transition temperature Tg of from about 45° C. to about 80° C.: R 1 OOCA 1 m B 1 n A 1 1 COOR 1′ (1) wherein each A 1 independently represents a methylene group, each B 1 , which may be the same as or different from every other B 1 , independently represents an aromatic hydrocarbon residue, each of R 1 and R 1′ independently represents a hydrogen atom or a monovalent hydrocarbon group, a sum of m and 1 is from 1 to 12, and n is from 1 to 3; R 2 OOCA 2 q B 2 r A 2 p COOR 2′ (2) wherein each A 2 independently represents a methylene group, each B 2 , which may be the same as or different from every other B 2 , independently represents an alicyclic hydrocarbon residue, each of R 2 and R 2′ independently represents a hydrogen atom or a monovalent hydrocarbon group, p is from 0 to 6, q is from 0 to 6, and r is from 1 to 3.