| 摘要 |
PURPOSE:To obtain magnetic paint having good dispersibility and to obtain a magnetic recording material having good abrasion resistance and good electromagnetic conversion propoerty by a method wherein an organic solvent is evaporated after dispersing and treating composition of matter including a polar compound havig one or more of ferromagnetic fine powder (e.g. -CO2H, -CONH2, -PO3H, -SO2H, -OH, -NH2) in a molecule and the organic solvent dissolving said polar compound. CONSTITUTION:As the ratio mixing composition of matter, a polar compound has ferromagnetic fine powder of 0.3-8wt%, preferably 0.5-2wt%. An organic solvent prefeably has 50-500wt% of the ferromagnetic fine powder. High ratio of organic solvent requires much energy for evaporation. Low ratio of organic solvent prevents uniform dispersion. Various kinds of kneading dispersers are used for dispersing composition of matter. The evaporation of the organic solvent may be done during a dispersion operation. The dispersion operation is normally done while heating the organic solvent at 80-100 deg.C. A pressure reduction opration may be added. For the preferable effect of surface treatment, the ratio of remained solvent after evaporation is 20wt%, preferably 5wt% of ferromagnetic powder. |
