| 摘要 |
PURPOSE:To enhance dispersibility of surface treated magnetic powder by a method wherein the surface of the powder is treated by the plural number of kinds of the specified phosphoric ester and coupling agents selected from the group of the specified organic silane compound, organic titanium compound or organic aluminum compound. CONSTITUTION:Magnetic powder is heat treated in an inactive organic solvent using phosphoric ester to be expressed by the formula [RO(AO)n]lPO(OH)3-l and phosphoric ester of one kind or two kinds or more selected from the group consisting of phosphoric ester of 10,000 or less of molecular weight having two phosphoric acid groups or more in one molecule, and the coupling agent of one kind or two kinds or more selected from the group consisting of an organic silane compound having the hydrolytic alkoxysilane group, an organic titanium compound having the hydrolytic titanium group and an organic aluminum compound having the hydrolytic alkoxy aluminum group. |
