Abstract: Provided are a dispersion excellent in the dispersibility of powder particles, dispersion stability, storage stability, and versatility; and a cosmetic blended with such dispersion. An oil dispersion of a surface-treated powder, comprising a surface-treated powder coated with a half ester oil, and a lipophilic solvent as a dispersion medium, wherein the half ester oil comprises an ester compound having 16 or more carbon atoms in total as can be obtained by reacting at least one kind of alcohols having 1 to 36 carbon atoms with at least one kind of carboxylic acids having 1 to 36 carbon atoms, and wherein the half ester oil has an acid value of 15 or more.

Abstract: The present invention is to provide oily makeup cosmetics which comprises an oligo ester obtained from (a) an aliphatic acid or a hydroxy aliphatic acid having 8 to 30 carbon atoms (straight or branched, saturated or unsaturated), (b) a straight or branched dibasic acid having 12 to 36 carbon atoms, and (c) glycerol or a glycerol condensate, and a hydrocarbon having a branched structure.

Abstract: Providing a surface-treated powder coated with a half ester oil, wherein the half ester oil contains an ester compound with 16 or more carbon atoms in total, as obtained by reacting one or more alcohols with one to 36 carbon atoms with one or more carboxylic acid with one to 36 carbon atoms and wherein the half ester oil has an acid value of 15 or more. The surface-treated powder of the invention has excellent adhesion to and spreadability on skin and hair, excellent dispersibility in general oils such as ester oil and triglyceride and in silicone-series or fluorine-series oils, and moist feel.