| 摘要 |
PURPOSE:To obtain a fog-free sharp image high in image density by mixing magnetic particles into a binder resin of a tetrafluoroethylene-ethylene copolymer specified in a magnetic particles to binder ratio, and specified in the range of the average particle diameter of the resin. CONSTITUTION:The electrophotographic carrier is prepared by dispersing the magnetic particles into the binder resin in an amount of 100-400pts.wt. per 100pts.wt. of the binder resin, and the average particle diameter of the carrier is regulated to 50-100mum, thus permitting the obtained carrier to prevent deterioration of adhesion of the fluoropolymer to a carrier core, leakage, and the like, and sticking of a toner to the surface of the carrier even when many sheets of paper are copied at a high speed. If the content of the magnetic particles is <100pts.wt., a force of holding the carrier to a developing sleeve is weakened, and if >400pts.wt., the resin is made unable to bind the magnetic particles. If the average particle diameter of the carrier is <50mum, scattering of the carrier occurs, and if >100mum, an electric charge imparting ability decreased. |
