| 摘要 |
PURPOSE:To secure an excellent orientation property, by impregnating the silicon into the water-containing iron oxide or the starting material of iron oxide obtained by dehydrating the water-containing iron oxide within a sealed container and under a high-pressure temperature when the iron oxide containing SiO2 is obtained. CONSTITUTION:The water-soluble silicate is mixed into the alkaline aqueous slurry (8-14PH) of the needle-shaped water-containing iron oxide or the iron oxide and then undergoes a water and heat treatment in a container and under an appropriate temperature (100-250 deg.C) and proper pressure. Thus the iron oxide containing SiO2 is obtained. Then the needle-shaped metal iron obtained by giving a reduction based on the normal method is dispersed into the resin of polyurethane and others and then coated on the base of the polyester film or the like with addition of an orientation process of magnetic field. Thus this degree of orientation is set as (degree of orientation) >=4.90X(square ratio in longer direction)-1.87 in the case of >=1,000thetae coercive force plus >=2,000G residual magnetic flux density with the square ratio in the longer direction set at the degree of orientation to the square ratio in the width direction of the tape respectively. |
