| 摘要 |
PURPOSE:To produce metallic magnetic powder having excellent particle orientation property with extremely less sintering by coating particles of needle-like iron oxyhydroxide and/or iron oxide with a water soluble polymer, fine particles SiO2 and Al(OH)3 in this order then subjecting the particles to a heat treatment follwed by a heating and reducing treatment. CONSTITUTION:Needle-like iron oxyhydroxide and of needle-like iron oxide are thoroughly dispersed in water contg. anionic surfactants. A water soluble polymer resin is added to these particles at 0.5-10wt% based on the iron atoms to form the uniform polymer resin films on the surfaces of the raw material particles. Thereafter 0.5-5.0wt% fine particles SiO2 based on the iron atoms are coated thereon by neutralization with sodium silicate and futher Al(OH)3 to form 0.1-3.0wt% Al2O3 based on the iron atoms are coated thereon by neutralization with AlCl3, etc. After such coated particles are filtered, rinsed and dried, the particles are heated to 500-700 deg.C in an inert gaseous atmosphere and are then subjected to a heating and reducing treatment in a reducing gaseous atmosphere. |
