| 摘要 |
PURPOSE:To obtain a toner fixable at low temperature and good in offset resistance by using as a binder resin 2 kinds of styreneacrylic type copolymers different in molecular weight from each other and regulating their monomer ratios, their mixing ratios, and their molecular weights. CONSTITUTION:The developing toner suitable for a heating roll fixing system is prepared by using the styrene-acrylic polymer lower in molecular weight having a styrene/acrylic monomer ratio of A and the styrene-acrylic polymer higher in molecular weight having a styrene/acrylic monomer ratio of B, controlling an A/B ratio to >1.3, and the lower molecular weight polymer/higher molecular weight polymer weight ratio to 80/20-40/60, an Mw/Mn ratio to <=3.0, where Mw is a weight average molecular weight, and Mn is a number average molecular weight, and ¦TgL-TgH¦ to <=10 deg.C, where TgL is the glass transition point of the lower polymer and TgH is that of the higher polymer. |
