| 摘要 |
PURPOSE:To disperse uniformly magnetic powder, additive, etc. and to improve an electromagnetic conversion characteristic by mixing a surface activated polishing material with magnetic powder, binder, etc. CONSTITUTION:A soln. dissolved therein with a surface active agent is heated to evaporate under the flow of an inert gas and the generated gas is fed to the inside of the furnace so as to be brought into contact with an abrasive material, thereby adsorbing the surface active agent on said material. The abrasive material is non-magnetic solid powder and powder of alumina, titanium oxide, titanium nitride, chromium nitride, chromium oxide, etc. Cation, anion, amphoteric and nonionic surface active agents are used for the surface active agent and polar and nonpolar solvents such as alcohol, hydroaromatic, solvent, etc. are used for the solvent to dissolve the surface active agent. The amt. of the surface active agent to be adsorbed is made preferably 0.5-10wt% by the weight of the magnetic powder. |
