| 摘要 |
PURPOSE:To widen the latitude of a toner concn. and to relieve the accuracy of a toner concn. control mechanism by sprinkling a charge control agent on the surface of a carrier and sticking a resin which is of a small grain size and hard to the surface, thereby widening the surface area. CONSTITUTION:The surface of the spherical resin carrier 1 formed by dispersing magnetic powder into a binder resin is coated with the soft resin layer 2 having small compression fracture strength to prevent exposing of the magnetic powder dispersed in the resin carrier 1. The charge control agent 3 is then stuck onto this layer and further, the resin powder 4 having the high compression fracture strength and small grain size is stuck thereto to expand the surface area of the carrier. The charge control agent is fine powder and is penetrated into the soft resin layer 2. On the other hand, the resin powder 4 having the grain size much larger than the grain size of the charge control agent 3 is partially penetrated into the soft resin layer 2 and is fixed. The excellent electrostatic chargeability and the wide latitude of the toner concn. are obtd. in this way and the accuracy of the toner concn. control mechanism is relieved. |
