Coating compositions containing polyisocyanates and aspartate-terminated urea/urethane prepolymers

A coating composition comprising

• a) 10 to 22% by weight, based on the weight of components a) and b), of an aspartate-terminated urea/urethane prepolymer that is the reaction product of
• i) an NCO prepolymer having a functionality of 1.8 to 2.2 and based on a linear or branched aliphatic diisocyanate and
• ii) a compound corresponding to formula I
• wherein
• X represents the residue obtained by removing the amino groups from a linear or branched aliphatic diamine,
• R1 and R2 may be identical or different and represent organic groups which are inert towards isocyanate groups at a temperature of 100° C. or less and
• R3 and R4 may be identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100° C. or less,
• b) 78 to 90% by weight, based on the weight of components a) and b), of a compound corresponding to formula I, and
• c) a polyisocyanate adduct prepared from an aliphatic diisocyanate and having an average functionality of 2.8 to 3.1,
• wherein components a), b) and c) are present in amounts sufficient to provide an equivalent ratio of aspartate groups to isocyanate groups of 1.2:1 to 1.0:1.3.