DEVELOPER FOR ELECTROPHOTOGRAPHY

PURPOSE:To provide the developer which allows the adjustment of an electrostatic charge level and has wear resistance by subjecting the surfaces of toner powder and carrier powder to plasma polymn. or plasma treatment and combining both to maintain an adequate electrostatic charge quantity. CONSTITUTION:The surfaces of the toner powder and the carrier powder are subjected to the plasma polymn. or plasma treatment to form the thin film having electrostatic chargeability and wear resistance on the powder surfaces. The toner or carrier powder is placed on an oscillation tray 13 of parallel plate electrodes 12 of a bell-jar 11 as a reactor and a prescribed gaseous monomer is introduced from an introducing pipe 14 into the bell-jar after evacuation. A high-frequency electric power is then supplied to the electrodes 12 to generate plasma and to polymerize the monomers. Both of the reformed toner and carrier are mixed at a prescribed ratio. The required electrostatic charge quantity is thus imparted to the developer and the wear resistance is increased by the thin film having the high adhesive strength.