Coating compositions containing alkoxysilanes

A coating composition containing

• I) 50 to 80% by weight, based on resin solids of components I) and II), of an alkoxysilyl-functional polyisocyanate polyurea which is the reaction product of
• A) a polyisocyanate component having an average functionality of 2.5 to 5.5, an NCO content of 11.0 to 20.0% by weight and a monomeric diisocyanate content of less than 10% by weight, and containing at least 50% by weight of a polyisocyanate prepared from 4,4′-diisocyanatodicyclohexyl-methane with
• B) at least 0.7 equivalents, based on the equivalents of isocyanate groups, of an aminosilane corresponding to formula (I)
• (RO)nY(3−n)Si—CH2CH2CH2—NHZ (I),
• wherein
• R represents methyl or ethyl,
• Y represents methyl,
• Z represents H, a C1-C12 alkyl or CH2CH2CH2—Si(OR)nY3−n, and
• n is 1, 2 or 3, and
• C) optionally other isocyanate-reactive compounds, and
• II) 20 to 50% by weight, based on resin solids of components I) and II), of a silane corresponding to formula (II)
• QSi(OX)3 (II),
• wherein
• X represents methyl, ethyl, isopropyl or butyl and
• Q represents hydrogen, C1 to C8 alkyl, phenyl, methoxy, ethoxy, 3-glycidyloxy-propyl, 3-aminopropyl or 3-methacroyloxy-propyl,
• or a hydrolyzate/condensate obtained from the silane of formula (II).