| abstract |
Disclosed is a toner binder which has high storage stability and can achieve both of good low-temperature fixability and good hot offset resistance (a broadened fixing temperature range). Specifically disclosed is a toner binder comprising, as constituting units, a carboxylic acid component (x) and a polyol component (y), wherein the component (x) comprises two or more kinds of dicarboxylic acids (X1), selected from among aromatic dicarboxylic acids and ester-forming derivatives of the same, in a total amount of 80 mol % or more and a trivalent or higher polycarboxylic acid (x2); the component (y) comprises a polyester resin (P) which is constituted by a polyester resin (A) comprising 80 mol % or more of an aliphatic diol (y1) having 2 to 10 carbon atoms optionally together with a linear polyester resin (B); and the storage modulus at 150° C. [G'150] of resin (A) is 20000 dyn/cm2 or more and the ratio of [G'150] to the storage modulus as 180° C. [G'180] thereof, i.e., [G'150]/[G'180], is 15 of less. |