PURPOSE: A make-up cosmetic, capable of changing the color tone reversibly by light stimulation without staining the skin or nail, and comprising a spiropyran compound in the form of a solid solution as a nucle substance enclosed in a microcapsule.
CONSTITUTION: A spiropyran compound is dispersed in an oil-soluble resin, e.g. polyacrylic acid, to give a solid solution, which is then pulverized and as a nuclear substance enclosed in a wall membrane to form a microcapsule. The formation of the microcapsule is preferably carried out by the coacervation with a polycation or polyanion as the wall membrane material. 0.1W20wt% the microcapsule is then mixed with a cosmetic oil or foundation to give a cosmetic capable of changing the color tone reversibly in the room and outdoors. The cosmetic is characterized by the prevented fatigue phenomenon by light stimulation which is a disadvantage of the spiropyran compound.
FUKUYAMA MASAKATSU
YASUI SHIGEO
TOMONO MASARU
NIPPON KANKOU SHIKISO KENKYUSH