| 摘要 |
PURPOSE:To enhance adhesion of a coating film to carrier particles, its coating strength, electrical resistance and fluidity of the carrier, and positive electrifiability of a toner by using as a surface coating material a resin obtained by reacting a specified polyester resin with an epoxy resin to harden them. CONSTITUTION:The carrier is coated with the surface coating material composed essentially of a mixture of a soln. of the polyester resin having unreacted carboxylic groups produced by reacting one or more kinds of polyols with one or more kinds of polycarboxylic acids, and a soln. of an epoxy resin, and hardened, thus permitting the resin coating film of the carrier thus obtained to be high in strength and abrasion resistance, and adhesion to the carrier, further, the carrier to be enhanced in electric resistance and fluidity, to give positive electrifiability, and separability from the carrier to the toner, and this developer to be adapted to a laser beam printer requiring both of high quality and long life, and the reliability of the printer to be enhanced. |
