| 摘要 |
PROBLEM TO BE SOLVED: To obtain a magnesium hydroxide-based flame retardant having excellent flame retardancy and excellent mechanical characteristics at a low cost. SOLUTION: This magnesium hydroxide-based flame retardant having an average particle diameter of 1.5 to 4.0μm, not containing >=30μm particles, and containing >=10μm particles in an amount of <=10 vol.% and <=1μm particles in an amount of <=35 vol.% is obtained by crushing the coarse powder of natural brucite ore containing Fe compounds in an amount of <=0.1 wt.% converted into metal Fe and Si compounds in an amount of <=1.5 wt.% converted into SiO2 with a heatable media crusher in the presence of 0.5 to 5 wt.% of a surface-treating agent comprising a higher fatty acid or its metal salt, a higher fatty acid ester, a higher fatty acid amide, a higher alcohol or a hydrogenated oil, simultaneously treating the surfaces of the crushed products with the surface-treating agent under heating, and then classifying the treated products. |
