| 摘要 |
PURPOSE:To produce metallic magnetic powder as a high density magnetic recording medium by immersing the compound powders of specific metals in an aq. soln. of silicone oil emulsified with a nonionic surfactant then heating the same in a reducing atmosphere followed by cooling. CONSTITUTION:Powders of oxide, acid hydroxide, oxalate, and formate of metals consisting essentially of Fe, Co, Ni and further contg. >=1 kinds of Cu, Cr, P, B Sn and other elements are immersed in an aq. of silicone oil emulsified with a nonionic surfactant such as higher aliphatic acid ester of polyethylene glycol. The aq. soln. of silicone oil is an aq. soln. of silicone oil of 0.5-20% of the metallic compounds and water of 3-100 times the metallic compounds, and the amt. of the surfactant is 0.1-10 times the silicone oil. The metallic compound powder filtered from the liquid and dried is heated and reduced at 300-650 deg.C in a reducing atmosphere of H2, CO, etc., thereafter it is cooled, whereby the metallic magnetic powder for high density magnetic recording medium such as magnetic tapes is produced. |
