Coating agent with high scratch resistance and weathering stability.

Coating composition based on aprotic solvents, containing at least one compound containing hydroxyl groups (A) and at least one compound containing isocyanate groups (B), wherein i) one or more ingredients of the coating present as additional functional components between a 2, 5 and 97, 5 mol%, relative to all the structural units (I) and (II), of at least one structural unit of formula (I) - N (X- SiR & quot; x (oR ') 3-x) n (X'-SiR & quot; and (oR') 3-y) m (I) where R '= hydrogen, alkyl or cycloalkyl, may be interrupted carbon chain groups oxygen, sulfur or nonadjacent NRa, with Ra = alkyl, cycloalkyl, aryl or aralkyl, X, X '= an alkylene group or linear cycloalkylene and / or branched 1 to 20 carbon atoms, R' '= alkyl, cycloalkyl, aryl or aralkyl, may be interrupted carbon chain by nonadjacent oxygen groups, sulfur or NRa, with Ra = alkyl, cycloalkyl, aryl or aralkyl, n = 0 to 2, m = 0 to 2, m + n = 2, x, y = 0 to 2, and between 2, 5 and 97, 5 mol%, relative to all the structural units (I) and (II), of at least one structural unit of formula (II ) - Z- (X-SiR & quot; x (oR ') 3-x) (II) where Z = -NH-, -NR-, -O-, with R = hydrogen, alkyl, cycloalkyl, aryl or aralkyl, may be interrupted carbon chain by nonadjacent oxygen groups, sulfur or NRa, with Ra = alkyl, cycloalkyl, aryl or aralkyl, R '= hydrogen, alkyl or cycloalkyl, may be interrupted carbon chain by oxygen groups, sulfur or NR nonadjacent, with Ra = alkyl, cycloalkyl, aryl or aralkyl, X = an alkylene group or linear cycloalkylene and / or branched 1 to 20 carbon atoms, R '' = alkyl, cycloalkyl, aryl or aralkyl, may be interrupted carbon chain by nonadjacent oxygen groups, sulfur or NRa, with Ra = alkyl, cycloalkyl, aryl or aralkyl, x = 0 to 2, and ii) the polyol (a) contains at least one poly (meth) acrylate polyol.