Patent ID: 6140002
Filing Date: 2000-10-31
Classification: G03G

Abstract:
A binder resin for toners, which comprises:a styrene-acrylic resin comprising a high molecular weight polymer component which is present in an amount of 20-70 wt. % of the binder resin and which has a weight average molecular weight of 2.times.10.sup.5 to 7.times.10.sup.5 with a ratio of weight average molecular weight to number average molecular weight of 1.8 to 4 and a low molecular weight polymer component having a weight average molecular weight of 5.times.10.sup.3 to 3.times.10.sup.4, wherein, in terms of the molecular weight distribution as measured by gel permeation chromatography, the main peak of the low molecular weight polymer component ranges in molecular weight from 1.times.10.sup.3 to 3.times.10.sup.4 and the high molecular weight polymer component has a first peak in the molecular weight region ranging from 5.times.10.sup.4 to 8.times.10.sup.5 and has two or more peaks, two or more shoulders or one or more peaks and one or more shoulders at the high molecular weight side above the molecular weight of the first peak.