PROBLEM TO BE SOLVED: To provide surface treated zinc oxide powder, which can give dispersion having high dispersibility to an organic solvent, small particle diameter, and low viscosity, and also dispersion and cosmetics which uses this surface treated zinc oxide powder.SOLUTION: Surface treated zinc oxide powder including no aluminum element, surface of which has been treated with N-acyl amino acid salt and which has ratio of A/B of within a range of 0.60 to 1.20, where A is a maximum peak strength in a range from 2895 to 2953 cm, and B is a maximum peak strength in a range from 870 to 886 cmwhen the powder is undergoes infrared spectroscopy.SELECTED DRAWING: None【課題】有機溶媒への分散性が高く、粒度が細かく低粘度の分散体を与えることができる表面処理酸化亜鉛粉体を提供する。また、この表面処理酸化亜鉛粉体を用いた分散体及び化粧料も提供する。【解決手段】表面がN-アシル化アミノ酸塩で処理されてなり、赤外分光法で測定した際に、2895~2953cm-1での最大ピークの強度Aと、870~886cm-1での最大ピークの強度Bとの比(A/B)が0.60~1.20の範囲内であり、アルミニウム元素を含まない表面処理酸化亜鉛粉体。【選択図】 なし
