| 摘要 |
Previous two-component coating compositions with enamine components were very slow-curing at low temperatures and resulted in yellowed products. The invention provides a binder composition which cures rapidly at low temperatures and results in non-yellowing products. It contains an acidic CH component comprising a polymer having at least two enamine functions in the molecule, obtained by A) transesterifying an aliphatic beta -ketocarboxylic ester with hydroxyl-containing compounds or polymers containing at least two hydroxyl groups in the molecule having an OH number of at least 50 and a number average molecular weight of from 500 to 10,000 and subsequent reaction with ammonia, primary and/or secondary amines, and B) an alpha , beta -unsaturated component comprising a compound with at least two groups of the general formula R1R2C=CR3X, where X is -CO- bonded via the radical of a di- or polyhydric alcohol, a di- or polyamine or amino alcohol to a further group R1R2C=CR3X, where R1, R2 and R3 are each hydrogen or alkyl, the components A) and B) are present in a ratio of from 2:1 to 1:1.5, based on their equivalent weights, the composition is present as a two-component system, and component A) contains a Lewis or Brönstedt base as catalyst. i |
