| 摘要 |
PURPOSE:To enhance offset resistance, fixability, and storage stability by using a binder resin made of a styrene-butadiene copolymer having a styrene unit content of 70-95mol%, containing one of inorganic salts hardly soluble in water having a specific resistivity of >=10<16>OMEGA.cm as an additive. CONSTITUTION:An electrostatic charge image developing toner comprising at least the binder resin and a colorant and fixable with a heat roller greatly depends upon the properties of the binder resin contained in the toner in the fixability, offset resistance, and heat blocking resistance of the toner, and these characteristics, contrary to each other, need to be satisfied by the binder resin. From these viewpoints, it is preferred to use as the binder resin the styrene- butadiene copolymer having a styrene unit content of 70-95mol%, especially, 80-92mol%, and to add the one of inorganic salts hardly soluble in water having a specific resistivity of >=10<16>OMEGA.cm as an additive to the toner, thus permitting chargeability to be stabilized for a long term, and fluctuation of charge quantity to be reduced against changes of temperature and humidity by incorporating both of said resin and said salt in the toner, and consequently, offset resistance, fixability, and storage stability to be enhanced. |
