| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface treated zinc oxide powder excellent in hydrophobicity and improved in washability, and to provide a cosmetic containing the same. SOLUTION: The surface treated zinc oxide powder is prepared by covering a surface of a zinc oxide base powder, that is so treated as to make an amount of eluted zinc ion measured by test method 1 not more than 30 ppm, with a polymer containing an acrylic monomer of a specific structure as a constituent monomer, e.g. 12-methacrylamide dodecanoic acid. The test method 1 for determining an amount of eluted zinc ion comprises dispersing a zinc oxide powder in water to be 0.01 mass%, regulating pH of the dispersion to be maintained at 7.5, and measuring a concentration (ppm) of zinc oxide in a supernatant separated by centrifuging the dispersion. COPYRIGHT: (C)2008,JPO&INPIT
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