Sun protection compositions

A method for preparing a cosmetic sun protection composition comprising mixing (i) at least one polyurethane urea obtained by

• A) preparing water-insoluble, non-water-dispersible, isocyanate-functional polyurethane prepolymers A) from
• A1) organic polyisocyanates,
• A2) polymeric polyols with number-average molecular weights of from 400 to 8000 g/mol, determined by gel permeation chromatography relative to polystyrene standard in tetrahydrofuran at 23° C. and OH functionalities of 1.5 to 6,
• A3) optionally hydroxy-functional compounds with molecular weights of 62 to 399 g/mol, and
• A4) optionally nonionic hydrophilizing agents,
• and
• B) then reacting some or all of their free NCO groups with at least one amino-functional compound B), comprising at least one amino-functional compound B2) which comprises one or more ionic and/or ionogenic groups, and (ii) a total of 16 to 35% by weight of one or more sun protection filter substances, based on total weight of said sun protection composition, wherein the at least one polyurethane urea is dispersed in water during or after step B), wherein the isocyanate-functional polyurethane prepolymers A) have a content of ionic and ionogenic groups below 1 milliequivalent per 100 g of polyurethane prepolymers, and
• wherein one of said sun protection filter substances is octocrylene which is present in an amount of from 4 to 12% by weight, based on total weight of the sun protection composition, and
• wherein the at least one polyurethane urea has repeat units containing urea groups, which are formed in the reaction of the isocyanate-functional prepolymers A) with the at least one amino-functional compound B), and wherein the sun protection composition has a SPF-boosting effect.

A cosmetic method for protecting skin against negative effects of solar radiation, comprising applying a composition comprising at least one polyurethane urea obtained by

• A) preparing water-insoluble, non-water-dispersible, isocyanate-functional polyurethane prepolymers A) from
• A1) organic polyisocyanates,
• A2) polymeric polyols with number-average molecular weights of from 400 to 8000 g/mol, determined by gel permeation chromatography relative to polystyrene standard in tetrahydrofuran at 23° C. and OH functionalities of 1.5 to 6,
• A3) optionally hydroxy-functional compounds with molecular weights of 62 to 399 g/mol, and
• A4) optionally nonionic hydrophilizing agents,
• and
• B) then reacting some or all of their free NCO groups with at least one amino-functional compound B), comprising at least one amino-functional compound B2) which comprises one or more ionic and/or ionogenic groups, and a total of 16 to 35% by weight of one or more sun protection filter substances, based on the total weight of the composition, to skin, wherein the at least one polyurethane urea is dispersed in water during or after step B, wherein the isocyanate-functional polyurethane prepolymers A) have a content of ionic and ionogenic groups below 1 milliequivalent per 100 g of polyurethane prepolymers, wherein at least one of said sun protection filter substances is octocrylene which is present in an amount of from 4 to 12% by weight, based on the total weight of the composition, and
• wherein the at least one polyurethane urea has repeat units containing urea groups, which are formed in the reaction of the isocyanate-functional prepolymers A) with the at least one amino-functional compound B), and wherein the sun protection composition has a SPF-boosting effect.