COSMETIC CONTAINING SILICA NANO STRUCTURE

PROBLEM TO BE SOLVED: To provide a cosmetic containing a silica structure that can be easily industrially produced, and achieving both of light-scattering property and a good feeling in use.SOLUTION: The cosmetic comprises a silica nano structure, which is an aggregate of fiber-like or ribbon-like basic structures having a width or thickness of 5 to 100 nm and an aspect ratio of 2 or more. The silica nanostructure is obtained through steps of: associating a polymer having a straight-chain polyethylene imine skeleton in an aqueous medium; obtaining a complex of the polymer and silica by adding alkoxysilane to the obtained associated polymer; and calcining the complex to remove the polymer. The aggregate has a size (in a longest part of the aggregate when observed in a TEM image) ranging from 1 μm to 20 μm. Further, the cosmetic contains a material comprising the above silica nano structure and a metal oxide nano crystal having a size of 2 to 10 nm bonded to the surface of the fiber-like or ribbon-like silica.