Abstract: To provide a method of producing a spherical aluminum nitride powder which has a large thermal conductivity and excellent filling property, and is useful as a filler for heat-radiating materials. [Means for Solution] The spherical aluminum nitride powder is produced by reductively nitriding a mixture of 100 parts by mass of an alumina or an alumina hydrate, 0.5 to 30 parts by mass of a rare earth metal compound and 38 to 46 parts by mass of a carbon powder at a temperature of 1620 to 1900° C. for not less than 2 hours.

Abstract: [Problems] To provide a spherical aluminum nitride powder that features high thermal conductivity and filling property, and that is useful as a filler for a heat radiating material, and a method of producing the same. [Means for Solution] A spherical aluminum nitride powder comprising aluminum nitride particles having an average particle diameter of 3 to 30 ?m, a sphericalness of not less than 0.75, and an oxygen content of not more than 1% by weight wherein, when the average particle diameter is d (?m), the specific surface area S (m2/g) satisfies the following formula (1), (1.84/d)?S?(1.84/d+0.5)??(1).

Abstract: [Problem] To provide a method of producing aluminum nitride that has high conducting property and can be excellently filled and is useful as a filler for heat-radiating materials, and an aluminum nitride powder obtained by the same method.

Abstract: [Problem] To provide a method of producing aluminum nitride that has high conducting property and can be excellently filled and is useful as a filler for heat-radiating materials, and an aluminum nitride powder obtained by the same method. [Means for Solution] An aluminum nitride powder is produced by reducing and nitriding: an alumina powder or a hydrated alumina powder having a primary grain size of 0.001 to 6 ?m; and a powder of a compound containing a rare earth metal element and having an average grain size in a range of 2 ?m to 80 ?m, the average grain size being not less than 6 times as great as the primary grain size of the alumina powder or the hydrated alumina powder; in the presence of a carbon powder at a temperature of 1620° C. to 1900° C. for not less than 2 hours.

Abstract: To provide a method of producing a spherical aluminum nitride powder which has a large thermal conductivity and excellent filling property, and is useful as a filler for heat-radiating materials. [Means for Solution] The spherical aluminum nitride powder is produced by reductively nitriding a mixture of 100 parts by mass of an alumina or an alumina hydrate, 0.5 to 30 parts by mass of a rare earth metal compound and 38 to 46 parts by mass of a carbon powder at a temperature of 1620 to 1900° C. for not less than 2 hours.

Abstract: [Problems] To provide a spherical aluminum nitride powder that features high thermal conductivity and filling property, and that is useful as a filler for a heat radiating material, and a method of producing the same. [Means for Solution] A spherical aluminum nitride powder comprising aluminum nitride particles having an average particle diameter of 3 to 30 ?m, a sphericalness of not less than 0.75, and an oxygen content of not more than 1% by weight wherein, when the average particle diameter is d (?m), the specific surface area S (m2/g) satisfies the following formula (1), (1.84/d)?S?(1.84/d+0.