1. The use of copolymers containing a) from 40 to 95 wt.% N-vinylpyrrolidone and b) from 5 to 60 wt.% Hydrophobically modified derivative of acrylic acid, as agents for improving the water resistance of a cosmetic composition. Use of copolymers according to claim 1, wherein the hydrophobically modified acrylic acid derivative is an acrylic acid ester or a methacrylic acid ester of the formula I, in which R is hydrogen or methyl and R is C -C alkyl. Use of copolymers according to claim 1 or 2, wherein the cosmetic composition contains at least one water-soluble, water-insoluble or sparingly water-soluble active ingredient or special effect agent. The use of copolymers according to claim 1 or 2, wherein the cosmetic composition is a sunscreen composition or a composition for eye, lip or face makeup. The use of copolymers containing a) from 40 to 95 wt.% N-vinylpyrrolidone and b) from 5 to 60 wt.% Hydrophobically modified acrylic acid derivative as means for improving the water resistance of a sunscreen composition that contains at least one UV filter, and / or to increase the sun protection factor of this sunscreen composition, which contains at least one UV filter. A method for improving the water resistance of a cosmetic composition, in which a copolymer containing a) from 40 to 95 wt% N-vinylpyrrolidone and b) from 5 to 60 wt% of a hydrophobically modified acrylic acid derivative is added to the composition of the cosmetic composition. A cosmetic composition selected from the group consisting of sunscreen and makeup compositions�1. Применение сополимеров, содержащихa) от 40 до 95 мас.% N-винилпирролидона иb) от 5 до 60 мас.% гидрофобно модифицированного производного акриловой кислоты,в качестве средств для улучшения водостойкости косметической композиции.2. Применение сополимеров по п.1, где гидрофобно модифицированное производное акриловой кислоты представляет собой сложный эфир акриловой кислоты или сложный эфир метакриловой кислоты формулы I,,в которойRозначает
