| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an alumina filler with which a high strength glass ceramic composition fitable to a glass slit or a resin composition having heat conducvity can be manufactured. <P>SOLUTION: A 50% accumulated average diameter (D50) for volume converted value of the alumina particle ranges within 3-6 μm, a ratio of D90 to D10, D90/D10, is 2.5 or less, the ratio of particles of at least 12 μm is 0.5 mass or less, the ratio of particles of at least 20 μm is 0.01 mass or less, and the ratio of particles of 1.5 μm or less is 0.2 mass or less, and a major phase is α phase. The ratio of a long axis diameter (DL) to a short axis diameter (DS) of the alumina particles, DL/DS, is 2 or less, the ratio of D50 to an average primary particle diameter (DP), D50/DP3, is 3 or less, Na<SB>2</SB>O content is 0.1% or less, B content is 80 ppm or more, CaO content is 500 ppm or more. <P>COPYRIGHT: (C)2003,JPO |
