Coating compositions containing polyisocyanates and aldimines which have improved storage stability

A coating composition which has an improved pot life without a corresponding increase in dry time when cured under ambient conditions comprising

• a) a polyisocyanate component,
• b) an aldimine based on the reaction product of a polyamine having 2 or more primary amino groups with an aldehyde corresponding to the formula:
• O=CHCH(R.sub.1)(R.sub.2)
• wherein R.sub.1 and R.sub.2 may be the same or different and represent hydrocarbon radicals containing 1 to 6 carbon atoms and
• c) 0.001 to 5 weight percent, based on the weight of components a) and b), of a dialkyl tin(IV) compound which contains a group selected from the group consisting of ester, sulfide, bisulfide, thiol and/or halide groups and which increases the reaction rate between isocyanate and hydroxyl groups by a factor of 100 when present in an amount of 1 mole percent in comparison to the reaction of these groups in the absence of a catalyst,
• wherein components a) and b) are present in an amount sufficient to provide an equivalent ratio of isocyanate groups to aldimine groups of 0.5:1 to 20:1.

A coating composition which has an improved pot life without a corresponding increase in dry time when cured under ambient conditions comprising

• a) a polyisocyanate component,
• b) an aldimine based on the reaction product of a polyamine having 2 or more primary amino groups with an aldehyde corresponding to the formula:
• O=CHCH(R.sub.1)(R.sub.2)
• wherein R.sub.1 and R.sub.2 may be the same or different and represent optionally substituted hydrocarbon radicals, or R.sub.1 and R.sub.2 together with the .beta.-carbon atom form a cycloaliphatic or heterocyclic ring and
• c) 0.01 to 1 weight percent, based on the weight of components a) and b), of a dialkyl tin(IV) compound which increases the reaction rate between isocyanate and hydroxyl groups by a factor of 100 when present in an amount of 1 mole percent in comparison to the reaction of these groups in the absence of a catalyst,
• wherein components a) and b) are present in an amount sufficient to provide an equivalent ratio of isocyanate groups to aldimine groups of 0.8:1 to 3:1.