ELECTROPHOTOGRAPHIC CARRIER, DEVELOPING DEVICE, IMAGE FORMING DEVICE AND PROCESS CARTRIDGE

摘要

PROBLEM TO BE SOLVED: To improve the toner spending resistance and electrostatic charge characteristics of a carrier by dispersing specified electrically conductive spherical particles in a bonding resin as the film forming component of a resin coating layer. SOLUTION: This electrophotographic carrier has a resin coating layer formed on the core material by coating with a resin compsn. The resin coating layer contains at least electrically conductive spherical particles having 1-20 μm number average particle diameter dispersed in the bonding resin. The true density of the particles is <=3 g/cm<3> , the ratio of the major axis size to the minor axis size is 1.0-1.5 and the volume resistivity is <=10<6> Ωcm. The particles are preferably spherical carbon particles surface-plated with an electrically conductive metal and/or an electrically conductive metal oxide, electrically conductive spherical particles obtd. by making the surfaces of resin particles electrically conductive by treatment or electrically conductive spherical particles obtd. by dispersing electrically conductive fine particles in resin particles.