A toner binder for dry toners which comprises a polyester; and a process for
producing
the toner binder. A known conventional technique for imparting low-temperature
fixing property and anti-hot offset property to a toner binder is to use a mixture
of two powdery polyesters. However, when the two polyesters mixed differ greatly
in softening point, the effect of mixing is not obtained and pigments show poor
dispersibility during toner production. The toner binder and the process eliminate
these problems. The toner binder comprises aggregates of binder resin particles
comprising two polyesters (A) and (B), wherein the polyester (A) has a higher softening
point than the polyester (B) and the polyesters (A) and (B) have been evenly mixed
in each particle. The process for producing a toner binder is characterized by
melt-mixing the two polyesters (A) and (B) at 80 to 180 C. The toner binder
is used mainly as an ingredient for dry toners.