| 摘要 |
Particulate alumina has a mean particle size corresponding to a volume-cumulative 50% mean particle size (D50) falling within a range of 3 to 6 mum, has a ratio of D90 to D10 that is 2.5 or less, contains particles that have a particle size of at least 12 mum in an amount of 0.5 mass % or less, particles that have a particle size of 20 mum or more in an amount of 0.01 mass % or less and particles that have a particle size of 1.5 mum or less in an amount of 0.2 mass % or less, and contains an alpha-phase as a predominant phase. In addition, the particulate alumina has a ratio of longer diameter (DL) to shorter diameter (DS) that is 2 or less and a ratio of D50 to mean primary particle size (DP) that is 3 or less. With these features, the particulate alumina has a narrow particle size distribution profile, causes little wear and exhibits excellent flow characteristics. |
