Spherical magnesium oxide and production method therefor

Abstract

The present invention provides a spherical magnesium oxide which has not only a high sphericity but also has a smooth surface and excellent moisture resistance and filling properties; and a productionmethod for the spherical magnesium oxide. Since the boron content and the iron content after firing are adjusted to fall within certain ranges, the present invention provides a spherical magnesium oxide which has filling properties and moisture resistance, which has a smooth surface, and has a sphericity as high as 1.00-1.20 as measured from an SEM photograph, in a relatively large range of volume-based cumulative 50%-particle size (D50) of 3-200 [mu]m as measured by a laser diffraction scattering particle size distribution measurement. Also provided is a predetermined spherical magnesium oxide obtained by an added-amount synergistic effect resulting from setting the boron content to 300-2000 ppm and the iron content to 100-1500 ppm.

Description

technical field

[0001] The present invention relates to spherical magnesium oxide with high sphericity, smooth surface, excellent moisture resistance and filling property, and a production method thereof. Background technique

[0002] Silica, alumina, etc. have been used conventionally as thermally conductive fillers, but the thermal conductivity of silica is low, and the heat dissipation is insufficient to cope with the increase in calorific value due to recent high integration, high power, and high speed. , There are problems in the stable operation of semiconductors. On the other hand, alumina, which has a higher thermal conductivity than silica, has improved heat dissipation compared to silica, but due to the high hardness of alumina, the wear of the kneading machine, molding machine, and mold may become severe. question. Therefore, magnesia, whose thermal conductivity is one digit higher than that of silica and about twice that of alumina, has a hardness lower than th...

Examples

Embodiment 1

[0066] Anhydrous magnesium chloride (MgCl 2 ) was dissolved in ion-exchanged water to prepare an aqueous magnesium chloride solution of about 3.5 mol / l. MgCl 2 Solution and 25% NaOH solution are pumped to the reactor with quantitative pumping respectively, and the continuous reaction is carried out, so that the MgCl 2 The reaction rate was 90 mol%.

[0067] Thereafter, boric acid (manufactured by Kanto Chemical Co., Ltd., reagent special grade) was added to the reaction liquid so that the boron content in the finally obtained spherical magnesium oxide became 650 ppm, and iron (II) oxide (manufactured by Hayashi Junyaku Kogyo Co., Ltd.) was added to make the iron content It becomes 350ppm. Thereafter, it was filtered, washed with water, and dried to obtain magnesium hydroxide. The obtained magnesium hydroxide was calcined at 900° C. for 1 hour to obtain magnesium oxide particles. An organic solvent was added to the magnesium oxide particles so as to have a concentration of...

Embodiment 2

[0069] Spherical magnesia was obtained by the same production method as in Example 1, except that boric acid was added to the reaction solution so that the boron content in the spherical magnesia became 900 ppm, and iron (II) oxide was added so that the iron content became 350 ppm. The physical properties thereof were evaluated in the same manner as in Example 1.

Embodiment 3

[0071] Spherical magnesia was obtained by the same production method as in Example 1, except that boric acid was added to the reaction solution so that the boron content in the spherical magnesia became 1000 ppm, and iron (II) oxide was added so that the iron content became 350 ppm. The physical properties thereof were evaluated in the same manner as in Example 1.

technical field

[0001] The present invention relates to spherical magnesium oxide with high sphericity, smooth surface, excellent moisture resistance and filling property, and a production method thereof. Background technique

[0002] Silica, alumina, etc. have been used conventionally as thermally conductive fillers, but the thermal conductivity of silica is low, and the heat dissipation is insufficient to cope with the increase in calorific value due to recent high integration, high power, and high speed. , There are problems in the stable operation of semiconductors. On the other hand, alumina, which has a higher thermal conductivity than silica, has improved heat dissipation compared to silica, but due to the high hardness of alumina, the wear of the kneading machine, molding machine, and mold may become severe. question. Therefore, magnesia, whose thermal conductivity is one digit higher than that of silica and about twice that of alumina, has a hardness lower than th...

Examples

Embodiment 1

[0066] Anhydrous magnesium chloride (MgCl 2 ) was dissolved in ion-exchanged water to prepare an aqueous magnesium chloride solution of about 3.5 mol / l. MgCl 2 Solution and 25% NaOH solution are pumped to the reactor with quantitative pumping respectively, and the continuous reaction is carried out, so that the MgCl 2 The reaction rate was 90 mol%.

[0067] Thereafter, boric acid (manufactured by Kanto Chemical Co., Ltd., reagent special grade) was added to the reaction liquid so that the boron content in the finally obtained spherical magnesium oxide became 650 ppm, and iron (II) oxide (manufactured by Hayashi Junyaku Kogyo Co., Ltd.) was added to make the iron content It becomes 350ppm. Thereafter, it was filtered, washed with water, and dried to obtain magnesium hydroxide. The obtained magnesium hydroxide was calcined at 900° C. for 1 hour to obtain magnesium oxide particles. An organic solvent was added to the magnesium oxide particles so as to have a concentration of...

Embodiment 2

[0069] Spherical magnesia was obtained by the same production method as in Example 1, except that boric acid was added to the reaction solution so that the boron content in the spherical magnesia became 900 ppm, and iron (II) oxide was added so that the iron content became 350 ppm. The physical properties thereof were evaluated in the same manner as in Example 1.

Embodiment 3

[0071] Spherical magnesia was obtained by the same production method as in Example 1, except that boric acid was added to the reaction solution so that the boron content in the spherical magnesia became 1000 ppm, and iron (II) oxide was added so that the iron content became 350 ppm. The physical properties thereof were evaluated in the same manner as in Example 1.

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