FERRITE CARRIER FOR ELECTROPHOTOGRAPHIC DEVELOPMENT AND REVERSAL DEVELOPING METHOD USING SAME

摘要

PROBLEM TO BE SOLVED: To provide a carrier having such electric resistance characteristics as high resistance in a low electric field and low resistance in a high electric field and contg. no harmful material. SOLUTION: This ferrite carrier has a basic compsn. consisting of 2-15mol% Li2 O, 5-30mol% MnO and 60-90mol% Fe2 O3 and is made of ferrite particles having 20-100μm average particle diameter. The ratio (R1 /R2 ) of the volume resistivity (R1 ) of the ferrite particles in an electric field having 200V/cm DC to the volume resistivity (R2 ) of the ferrite particles in an electric field having 10kV/cm DC is >=10 and the resistivity R1 is 1×10<5> -1×10<13>Ω.cm.