Coating agents having high scratch resistance and weathering stability

A coating composition comprising:

• (a) at least one hydroxyl-containing compound (A),
• (b) at least one compound (B) having free and/or blocked isocyanate groups,
• (c) at least one catalyst (D) for the crosslinking of silane groups, said catalyst (D) comprising phosphorus and nitrogen,
• where
• (i) one or more constituents of the coating composition contain hydrolyzable silane groups and
• (ii) the coating composition can be finally cured to a coating which has statistically distributed regions of an Si-O-Si network
• (iii) one or more constituents of the coating composition comprise between 2.5 and 97.5 mol %, based on the entirety of structural units (II) and (III), of at least one structural unit of the formula (II)
• —N(X—SiR″x(OR′)3-x)n(X′—SiR″y(OR')3-y)m (II)
• where
• R′ =hydrogen, alkyl or cycloalkyl, in which a carbon chain may comprise nonadjacent oxygen, sulfur or NRa groups, with Ra =alkyl, cycloalkyl, aryl or aralkyl,
• X, X′ =linear and/or branched alkylene or cycloalkylene radical having 1 to 20 carbon atoms,
• R″ =alkyl, cycloalkyl, aryl or aralkyl, in which a carbon chain may comprise nonadjacent oxygen, sulfur or NRa groups, with Ra =alkyl, cycloalkyl, aryl or aralkyl,
• n =0 to 2, m =0 to 2, m+n =2, and x =0 to 2, y =0 to 2, and
• between 2.5 and 97.5 mol%, based on the entirety of structural units (II) and (III), of at least one structural unit of the formula (III)
• —Z—(X—SiR″x(OR′)3-x) (III),
• where
• Z =—NH—, —NR—, —0—, with
• R =alkyl, cycloalkyl, aryl or aralkyl, in which a carbon chain may comprise nonadjacent oxygen, sulfur or NRa groups, with Ra =alkyl, cycloalkyl, aryl or aralkyl,
• x =0 to 2, and
• X, R′, R″ have the meaning given in formula (II).

A coating composition comprising:

• (a) at least one hydroxyl-containing compound (A),
• (b) at least one compound (B) having free and/or blocked isocyanate groups,
• (c) at least one catalyst (D) for the crosslinking of silane groups, said catalyst (D) being an amine-blocked bis(ethylhexyl) phosphate
• where
• (i) one or more constituents of the coating composition contain hydrolyzable silane groups and
• (ii) the coating composition can be finally cured to a coating which has statistically distributed regions of an Si—O—Si network.