Patent ID: 8642018
Filing Date: 2014-02-04
Classification: A61K,A61Q

Abstract:
1. A water-in-oil emulsified sunscreen cosmetic, comprising: a) hydrophobic zinc oxide powder, manufactured through a method in which a zinc oxide powder is dispersed in a solvent, and the surface of the zinc oxide powder is treated with a phosphate ester having a perfluoroalkyl represented by general formula (1) as follows: (wherein Rf is a perfluoroalkyl group or a perfluorooxyalkyl group having 3-21 carbons that is a straight chain or branched and is a single chain length or a composite chain length; n is an integer from 1-12, and y is a number from 1-3), and an ester of a copolymer of 30,000-300,000 MW of 2-ethylhexyl acrylate, methacrylate, methyl methacrylate, or butyl methacrylate and a methylpolysiloxane some of whose methyl groups have been substituted with a hydroxypropyl group, to produce the hydrophobic zinc oxide powder, said ester of a copolymer represented by general formula (2) as follows: (wherein n is an integer, a, b, c, and d are mole ratios within the copolymer and are not 0, and d is at least 40 mole percent but not more than 60 mole percent), wherein the hydrophobic zinc oxide powder is manufactured using microparticle zinc oxide powder having a first-order particle diameter of 1 μm or less, and the amount of solvent that is used is within a range of 50 to 90 wt % of the zinc oxide powder; (b) volatile silicone; (c) 1-10 wt % caprylylmethicone, based on the total weight of the sunscreen cosmetic, the caprylylmethicone further present in an amount of 12.5-40 wt % of the amount of volatile silicone; (d) 0.5-4 wt % of a polyoxyalkylene-modified organopolysiloxane; (e) water; (f) from 0-2 wt % of a nonvolatile non-polar oil and/or nonvolatile silicone oil; and (g) octylmethoxy cinnamate, wherein the hydrophobic zinc oxide powder absorbs from 10-40 mL/100 g of oil, and said sunscreen cosmetic exhibits excellent long lasting coverage and ease of washability.