Patent ID: 7314695
Filing Date: 2008-01-01
Classification: G03G

Abstract:
1. A toner for developing electrostatic charge images comprising at least binder resin, colorant, and charge control agent, wherein the charge control agent comprises a low molecular weight polymer selected from the group consisting of a positive charge-type low molecular weight polymer in which quaternary ammonium salt type functional groups are added to a styrene-acrylic main chain and a negative charge-type low molecular weight polymer in which sulfonic acid type functional groups are added to a styrene-acrylic main chain, and the binder resin comprises ethylene-norbornene copolymer resin having at least two peaks in molecular weight distribution measured by gel permeation chromatography and comprises a high molecular weight fraction having number average molecular weight of 7,500 or more at 5 to 50 weight % to the binder resin, and Mw/Mn is 22.6 to 27.5, wherein Mw is the weight average molecular weight of the ethylene-norbornene copolymer resin and Mn is the number average molecular weight of the ethylene-norbornene copolymer resin.