| 摘要 |
PURPOSE:To obtain a titled carrier which has an excellent picture image characteristic and a long life by substituting part of SrO of magnetoplumbite with specified metallic oxide. CONSTITUTION:Part of SrO in a basic compsn. having the structure of magnetoplumbite of 5-30mol% SrO, 10-30mol% ZnO and 55-80mol% Fe2O3 is substituted with 1 or more kinds metallic oxides selected among Li2O, MnO, CuO, Al2O3, NiO, MgO, etc. and the raw material powders thereof are mixed and are calcined at 800-1,200 deg.C, whereafter the calcined mixture is ground to 0.3-2.0mum average grain size. The powder is mixed with a binder and the mixture is granulated and is then calcined at 1,100-1,400 deg.C, whereby a ferrite carrier for electrophotography having 10<5>OMEGAcm electric resistivity, >=30emu/g satd. magnetization value, <=100Oe coercive force, >=50 magnetic permeability >=120 deg.C Curie point, >=1,000g/cm<2> strength and 30-1,000mum average grain sizes is obtd. |
