| 摘要 |
PURPOSE:To provide the magnetic toner which allows easy electrostatic charge, exhibits stable developability and exhibits excellent transferability by coating the surface of core particles with a conductive material and insulating material having specific electric conductivity and specifying the weight average particle sizes thereof. CONSTITUTION:The surface of the core particles constituted of a binder consisting of resin components, magnetic powder and additives is coated with the conductive material having <=1mum weight average particle size and >=10<-8>(OMEGA.cm)<-1> electric conductivity and is further coated with the insulating material having 0.1 to 1.0mum weight average particle size and <=10<-8>(OMEGA.cm)<-1> electric conductivity in such a manner that the conductive material is not exposed to at least the outermost layer. The magnetic toner having 5 to 50mum weight average grain size is thus obtd. The electrostatic transfer is enabled by properly selecting the material compsn. and production conditions and the electric conductivity characteristic to stabilize the conduction development is obtd. The stable development is executed in this way and further, the electrostatic transfer to plain paper is possible as the toner exhibits a stable insulating characteristic in a static state. |
