| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cosmetic, excellent in UV-A absorptivity, excellently familiar with skin, capable of manifesting an excellent preservation stability by formulating a benzalhydantoin-based ultraviolet absorber having extremely small solubility. SOLUTION: This cosmetic is obtained by formulating the powder of a 5-(3,4- dialkoxybenzal)hydantoin of the formula (R<1> and R<2> are each a 1-3C alkyl) and/or the power obtained by carrying out a coating treatment of a power for cosmetics (e.g. a pigment) with the compound of the formula as an ultraviolet absorber. The compound of the formula can be obtained by condensing a 3,4-dialkoxybenzaldehyde with hydantoin using a basic catalyst. The powder formulated as an ultraviolet absorber preferably has an average particle diameter of 0.001-100μm, and the mixing amount of the powder is preferably 0.01-10 wt.%. As a result, the cosmetic having no problem of crystal precipitation, etc., even if preserved for a long term, and excellent in functionality and form stability is expected.
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