| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a magnetite particle powder reduced in a content of coarse agglomerates and being easily dispersible and excellent in hue and electrical properties. <P>SOLUTION: The magnetite particle powder comprises a magnetite particle containing silicon, having an average primary particle diameter of 0.10-0.30 μm and a D90 value of 0.40-1.00 (as determined by laser diffraction/scattering particle size distribution measurement) and satisfying a ratio A/B of 0.70-1.30 (wherein A is the rate (A%) of the Fe (divalent) to the total Fe amount within a surface 10 mass% portion, and B is the rate (B%) of Fe (divalent) to the total Fe amount within the remaining 90 mass% portion). <P>COPYRIGHT: (C)2008,JPO&INPIT |
