Spherical magnesium oxide and method for producing same, resin filler, and resin composition

Spherical magnesium oxide having the total content of elements belonging to the 3rd to 4th periods of the periodic table (except for the elements belonging to the 2nd and 18th groups) of 500 to 12,000 ppm, having a volume-based cumulative 50% particle diameter (D50) measured by a laser diffraction/scattering particle size distribution measurement of 1 to 200 μm, and wherein a sphericity read from a SEM photomicrograph of 1.00 to 1.20.

A method for producing spherical magnesium oxide, comprising:

• 1) preparing a slurry of spherical magnesium carbonate by reacting an aqueous solution of magnesium salt and an aqueous solution of carbonate and coagulating the resulting magnesium carbonate;
• 2) preparing spherical magnesium carbonate particles by filtering the slurry of spherical magnesium carbonate, washing with water, and drying;
• and 3) preparing spherical magnesium oxide by firing the spherical magnesium carbonate particles, wherein in at least one of 1) to 3), the amount of each element belonging to the 3rd to 4th periods of the periodic table (except for the elements belonging to the 2nd and 18th groups) and yttrium is adjusted so that the total content of the elements belonging to the 3rd to 4th periods of the periodic table (except for the elements belonging to the 2nd and 18th groups) and yttrium is 500 to 12,000 ppm in the spherical magnesium oxide after firing.

A method for producing a spherical magnesium oxide, comprising:

• 1) preparing a slurry of spherical magnesium carbonate by reacting an aqueous solution of magnesium salt and an aqueous solution of carbonate and coagulating the resulting magnesium carbonate;
• 2) preparing spherical magnesium carbonate particles by filtering the slurry of spherical magnesium carbonate, washing with water, and drying;
• and 3) preparing a spherical magnesium oxide by firing the spherical magnesium carbonate particles, wherein in at least one of 1) to 3), the amount of each element belonging to the 3rd to 4th periods of the periodic table (except for the elements belonging to the 2nd and 18th groups) is adjusted so that the total content of the elements belonging to the 3rd to 4th periods of the periodic table (except for the elements belonging to the 2nd and 18th groups) is 500 to 12,000 ppm in the spherical magnesium oxide after firing.