| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide composite magnetic particles having magnetism, provided with various sorts of color tones including black, red and yellow groups and especially suited to security purposes and biological and biochemical purposes. <P>SOLUTION: Composite magnetic particles consisting of oxide magnetic particles of which the average grain size is in a range of 0.02-5.0 μm or mixed particles obtained by adding pigment grains of which the average grain size is in a range of 0.02-5.0 μm and silica, having magnetism based on oxide magnetic particles and having a prescribed color tone based on the oxide magnetic particles and pigment grains, composite magnetic particles constituted of forming a film of silica on the surface of each oxide magnetic particle or each mixed particle, and composite magnetic particles of which the average grain size is in a range of 0.5-10 μm and the saturation magnetism is in a range of 0.5-20 A m<SP>2</SP>/kg (0.5-20 emu/g) are provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
