| 摘要 |
PURPOSE:To improve orientation and filling by a method wherein sintered powder which is coated with magnetic adjustment and sintering preventive compositions is compacted, and then it is reduced. CONSTITUTION:The powder, which is made by coating the surface of particles of washed iron oxyhydroxide with magnetic adjustment components and sintering preventive components, is dehydrated with heating in nonreductive atmosphere to make sintered powder. The sintered powder is put in a pressure kneader, and water is added to it. Then, it under goes compaction process to obtain a dense, sintered cake. After the compacted, sintered powder has been put in a stirr floating type reactor and heated while being supplied with H2, the gas is replaced by N2 to cool it. Then, after the obtained, reduced powder has been dipped into toluene, it is contacted with air to obtain stable and dry magnetic iron powder with oxide coating formed thereon. With this method, it is made possible to obtain magnetic iron powder with superior orientation and filling, thereby improving the performance of magnetic tape with such iron powder. |
