| 摘要 |
PURPOSE:To improve resolution, solid-black uniformity, etc., by forming the above carriers of spherical particles having >=95% spheroidization rate and <=65mum average particle size and allowing the control of saturation magnetization between 40 and 90emu/g. CONSTITUTION:Both iron oxide powder 3 and gaseous nitrogen for transportation are charged into a combustion flame gas and the iron powder is melted to a spheroidal shape in the flame 2. The concn. of the oxygen in the gas is controlled and the molten iron is dropped into water 12 in a cooling container 13, by which the molten iron is rapidly cooled. The surface thereof is coated with a resin at need. Since such production process is adopted, spherical particles having <=500e coercive force, >=40emu/g saturation magnetization, >=10<4>OMEGA.cm electric resistivity, <=3g/cm<3> bulk density, >=95% spheroidization rate, high surface smoothness and <=65mum average particle size are obtd. The control of the saturation magnetization is possible between 40 and 90emu/g. The resolution, solid-black uniformity, etc., are improved in this way. |
