Tateho Chemical Industries Co., Ltd.

Denka Company Limited

Tomoaki Chikazawa

Shuji Sasaki

Junichi Nakazono

Yoshihisa Osaki

Akinori Saito

Yoshihisa Ohsaki

Mareshi Takegaki

Keisuke Tsutsumi

Takeshi Konishi

Yuki Morita

Shotaro Tanoue

Miki Yamamoto

The objective of the present invention is to provide: a spherical magnesium oxide which has high sphericity and excellent moisture resistance, and has excellent fluidity by which a resin composition exhibits excellent fluidity when filled in a resin; and a method for producing the same. The present invention is a spherical magnesium oxide characterized in that: 10-2000 ppm of boron is contained; the total content of silicon and phosphorus is 300-4000 ppm; and the sphericity that can be read from the SEM photograph is 1.00-1.10, when the volume-based cumulative 50% particle diameter (D50) measured by means of a laser diffraction scattering particle size distribution measurement, is in the range of 3-200 μm.

Spherical magnesium oxide, manufacturing method thereof, thermal conductive filler and resin composition

Provided are: a spherical magnesium oxide having not only high sphericity but also smooth surface and having excellent moisture resistance and excellent filling properties, and a method producing the same. In the present invention, by controlling the boron and iron contents of the calcined magnesium oxide to be in the respective predetermined ranges, there is provided a spherical magnesium oxide having a volume-based cumulative 50% particle diameter (D50), as measured by a laser diffraction/scattering particle size distribution measurement, in the range of from 3 to 200 &#x3bc;m, which is the range for a relatively large particle diameter, and a high sphericity of 1.00 to 1.20, as measured from viewing a SEM photomicrograph, as well as smooth surface, and having excellent moisture resistance and excellent filling properties. A predetermined spherical magnesium oxide is provided by virtue of the synergies obtained from the boron content of 300 to 2,000 ppm and the iron content of 100 to 1,500 ppm.

Spherical magnesium oxide and production method therefor

Provided is a magnesium oxide-containing spinel powder capable of producing a ceramic sintered body having high strength and excellent strength stability. In the magnesium oxide-containing spinel powder, a 50% particle diameter (D50) is 0.30 to 10.00 &#x3bc;m, a ratio (D90-D50)/(D50-D10) of a difference between a 90% particle diameter (D90) and the 50% particle diameter (D50) and a difference between the 50% particle diameter (D50) and a 10% particle diameter (D10) is 1.0 to 5.0, and a composition ratio of Mg and Al in terms of an oxide equivalent content is 50 to 90% by weight of MgO and 10 to 50% by weight of AlO.

Magnesium oxide-containing spinel powder and method for producing same

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Ako, Japan

Tomoaki Chikazawa