Patent ID: 8318855

Claim:
A two-pack coating composition comprising crosslinking agents selected from the group consisting of non-blocked polyfunctional isocyanates I, polyaziridines Z, and carbodiimides Y, and an aqueously dispersed polyurethane U wherein the polyurethane U is obtained by reaction of polyfunctional isocyanates A, oils B that are esters of polyhydric alcohols B1 and fatty acids B2, wherein at least a mass fraction of 40% of the said fatty acids B2 is comprised of fatty acids B21 which have at least one hydroxyl group and, optionally, at least one olefinic unsaturation, such oils B having a hydroxyl number of from 120 mg/g to 230 mg/g, with low molar mass polyols C having a number average molar mass M n of up to 400 g/mol, and compounds D which possess at least two groups which are reactive toward isocyanate groups and at least one group which is capable of forming anions, to form a prepolymer ABCD which is then reacted with compounds F which carry at least one hydroxyl group F1 and at least one functional group F2 selected from the group consisting of amino groups, mercapto groups, and hydroxyl groups F21 that are activated so that their reactivity towards isocyanate groups is higher than that of hydroxyl group F1, until the NCO content in the reaction mixture has fallen to zero, wherein the ratio of the number of isocyanate groups in A to the total number of hydroxyl groups in the hydroxy-functional compounds B and D is from 1.05 to 1.4.