| 摘要 |
PURPOSE:To improve dispersion characteristic in an organic binder during adjustment of magnetic paint by containing at least a kind of the hydroxides of Mg, Ca, Sr and Ba. CONSTITUTION:With a magnetic iron oxide powder such as gamma-Fe2O3 used as the core crystal, cobalt or metal oxide of cobalt and iron is deposited, particularly a ferrous compound and cobalt compound are deposited. In case a metal hydroxide is contained to such iron oxide and it is heated, it is heated up to 60- 150 deg.C so that a hydroxide is not decomposed. An amount of hydroxide is selected to 0.01-10pts.wt. for the 100pts.wt. of magnetic iron oxide containing cobalt which becomes the nucleus crystal. It is desirable that the hydroxide is uniformly formed and gradual advancement of neutralization is effective for uniform containing of hydroxide. As compared with a magnetic tape obtained using an iron oxide not containing metal hydroxide, the squareness ratio (Br/Bm) and orientation can be improved. |
