Water-based polyurethane coatings and coatings made from such coatings with high scratch resistance and good chemical resistance

摘要

Disclosed are aqueous coating compositions comprising at least one hydroxyl-containing compound (A), at least one compound (B) having isocyanate groups and also having hydrolyzable silane groups, and at least one catalyst (C) wherein the compound (B) has 10 mol % to less than 90 mol % of at least one structural unit (I) -N(X-SiR''x(OR')3-x)n(X'-SiR''y(OR')3-y)m(I) Where R'=hydrogen, alkyl or cycloalkyl, X, X'=linear and/or branched alkylene or cycloalkylene radical having 1 to 20 carbon atoms, R''=alkyl, cycloalkyl, aryl or aralkyl, n=0 to 2, m=0 to 2, m+n=2, and x, y=0 to 2, and more than 10 to 90 mol % of at least one structural unit (II) -Z-(X-SiR''x(OR')3-x) (II), where Z=-NH-, -NR-, -O- or -S-, where R=alkyl, cycloalkyl, aryl or aralkyl, and x, X, R' and R'' have the definition indicated for formula (I).