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 5W30mol% SrO, 10W30mol% ZnO and 55W80mol% 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 800W1,200°C, whereafter the calcined mixture is ground to 0.3W2.0μm average grain size. The powder is mixed with a binder and the mixture is granulated and is then calcined at 1,100W1,400°C, whereby a ferrite carrier for electrophotography having 105Ωcm electric resistivity, ≥30emu/g satd. magnetization value, ≤100Oe coercive force, ≥50 magnetic permeability ≥120°C Curie point, ≥1,000g/cm2 strength and 30W1,000μm average grain sizes is obtd.
EGUCHI KIYOSHI
CHINJIYU MINORU
SHIMAZOE AKIRA
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