| 摘要 |
PURPOSE:To obtain a magnetic recording medium having a magnetic layer with superior wear resistance and surface smoothness, by using a magnetic coating contg. aluminum oxide surface-treated with silicon oxide. CONSTITUTION:Aluminum oxide, chromium oxide or titanium oxide having about 0.5-2mum particle size is dispersed in an aqueous alkali soln. of silicate, and by blowing gaseous CO2 or the like, the soln. is neutralized to deposit silicic acid on the surface of the oxide. The oxide is then dried by heating to form aluminum oxide or the like covered with silicon oxide. A magnetic coating is prepared by mixing 100pts.wt. magnetic powder (A) with about 0.1-20pts.wt. of the covered aluminum oxide or the like (B), a binder resin (C) and a solvent (D). The coating is applied to a polyester base film by a conventional method to obtain a magnetic recording medium. |
