JP2003192339A5 - - Google Patents

Claims (23)

The volume equivalent 50% cumulative average diameter (D50) is in the range of 3 to 6 μm, the ratio of D90 to D10, D90 / D10 is 2.5 or less, and the ratio of particles of 12 μm or more is 0.5 mass. The ratio of particles of 20 μm or more is 0.01% by mass or less, the ratio of particles of 1.5 μm or less is 0.2% by mass or less, and the α phase is the main phase. Alumina grains. Ratio of major axis diameter (DL) and minor axis diameter (DS) of alumina particles, DL / DS is 2 or less, ratio of D50 to average primary particle diameter (DP), D50 / DP is 3 or less The alumina particles according to claim 1. The alumina particles according to claim 1 or 2, wherein the Na ₂ O content is 0.1% or less, the B content is 80 ppm or more, and the CaO content is 500 ppm or more. A method for producing alumina grains, characterized by adding a boron compound, a halide, and a calcium compound to aluminum hydroxide or alumina and firing. The production of alumina grains according to claim 4, wherein the halide is at least one selected from the group consisting of aluminum halide, ammonium halide, calcium halide, magnesium halide, and hydrogen halide. Method. 6. The method for producing alumina particles according to claim 4, wherein the boron compound is at least one selected from boric acid, boron oxide, and borate. The halide is at least one selected from the group consisting of aluminum fluoride, aluminum chloride, ammonium chloride, ammonium fluoride, calcium fluoride, calcium chloride, magnesium chloride, magnesium fluoride, hydrogen fluoride, hydrogen chloride; It exists, The manufacturing method of the alumina grain of any one of Claims 4-6 characterized by the above-mentioned. The alumina compound according to any one of claims 4 to 7, wherein the calcium compound is at least one selected from the group consisting of calcium fluoride, calcium chloride, calcium nitrate, and calcium sulfate. Production method. The addition amount of the boron compound is within a range of 0.05 to 0.50% by mass with respect to alumina in terms of boric acid, and the addition amount of the calcium compound is 0.03 to 0.10% by mass with respect to alumina in terms of Ca. Within the range, the added amount of the halide is in the range of 0.20 to 0.70 mass% in terms of the ratio to the alumina, The alumina grains according to any one of claims 4 to 8, Production method. The firing temperature is in the range of 1200 to 1550 ° C, and the maximum temperature holding time is in the range of 10 minutes to 10 hours, The alumina particles according to any one of claims 4 to 9, Production method. Crushing is carried out with an airflow pulverizer at a nozzle jet pressure of 2-6 × 10 ⁵ Pa at a relative pressure, or with a ball mill or vibration mill using alumina balls, and fine particles are removed with an airflow classifier. The method for producing alumina particles according to any one of claims 4 to 10, wherein: The alumina grain manufactured by the manufacturing method of the alumina grain of any one of Claims 4-11. The ceramic composition containing the alumina grain of any one of Claims 1-3 or 12. The composition according to claim 13, wherein the content of alumina particles is 10% by mass or more and 90% by mass or less. The composition containing the alumina grain of any one of Claims 1-3 or 12, and a high molecular compound. The polymer compound is at least one selected from the group consisting of aliphatic resins, unsaturated polyester resins, acrylic resins, methacrylic resins, vinyl ester resins, epoxy resins, and silicone resins. 15. The composition according to 15. The composition according to claim 15 or 16, wherein the content of alumina particles is 80% by mass or more. The composition according to any one of claims 15 to 17, wherein the polymer compound is an oily substance. The composition according to any one of claims 15 to 18, wherein the polymer compound has a softening point or a melting temperature within a temperature range of 40 ° C to 100 ° C. The heat conductive composition containing the composition of any one of Claims 15-19. An electronic component or a semiconductor device comprising the composition according to claim 20 provided between a heat generator and a heat radiator. A refractory, glass, ceramics or a composite material thereof containing the alumina particles according to any one of claims 1 to 3. The board | substrate material or sealing material of an electronic component containing the alumina particle of any one of Claims 1-3 or 12, or a filler or finishing wrapping material.