ELECTROSTATIC DEVELOPER AND FULL-COLOR ELECTROSTATIC DEVELOPING METHOD

摘要

PROBLEM TO BE SOLVED: To obtain an electrostatic developer less liable to cause an edge effect and untransfer of a secondary color and particularly suitable for a tandem system by using silicone oil-contg. toner particles and magnetic carrier particles surface-treated with a specified resin coating material. SOLUTION: The electrostatic developer contains silicone oil-contg. toner particles and magnetic carrier particles surface-treated with a resin coating material contg. electrically conductive fine particles. The toner particles are fine powder contg. a colorant, silicone oil and, optionally, an electrostatic charge controlling agent, other releasing agent and other materials dispersed in a binder resin. The average particle diameter of the toner particles is appropriately 4-20 μm. The binder resin may be selected from known various resins suitable for a toner and polyethylene or polychlorostyrene is, e.g. used.