| 摘要 |
PURPOSE:To obtain a titled carrier which has an excellent image characteristic and a long life by substituting Li2O and/or MnO in a basic compsn. of Li2O, MnO, Fe2O3 with specified metallic oxide. CONSTITUTION:Li2O and/or MnO in the basic compsn. consisting of 3-15mol% Li2O, 5-17mol% MnO, 60-85% Fe2O3 are substituted with 1 or more kinds selected among ZnO, MgO, CuO, NiO, Al2O3, etc. to prepare raw material powders which are calcined at 800-1,200 deg.C and are ground to 0.3-2.0mum average grain sizes. A binder is added to the powder and the mixture is granulated and is then calcinated at 1,100-1,400 deg.C, whereby a ferrite carrier for electrophotography having 10<5>-10<12>OMEGAcm electric resistivity, >=20emu/g satd. magnetization value, <=100 Oe coercive force, >=50 magnetic permeability, >=120 deg.C Curie point, >=1,000g/cm<2> strength and 30-1,000mum average grain size is obtd. |
