Crosslinkable composition crosslinkable by real michael addition (RMA) reaction

Method for the improvement of the appearance and hardness of a cured coating, comprising providing a crosslinkable composition comprising:

• a. a component A with at least 2 RMA donor groups being acidic protons C—H in activated methylene or methine groups, and
• b. a component B with at least 2 RMA acceptor groups being activated unsaturated groups, and
• c. a catalyst system C that contains, or is able to generate a basic catalyst capable of activating the RMA reaction between components A and B,
• d. wherein the cross-linkable composition further comprises an X—H group containing component D that is also a Michael addition donor reactable with component B under the action of catalyst C, wherein X is N, P, O, S or wherein X is C as part of an acidic methyl group, wherein component A is malonate or acetoacetate, and wherein the X—H group of component D has a higher acidity than the C—H groups in component A, wherein component D has a pKa, defined in aqueous environment, of at least one unit less than that of the C—H groups in component A,
• alone or in combination with component A2 comprising C—H acidic protons in activated methylene or methine groups having a higher acidity than component A and which is also RMA reactive towards component B, or in combination with an RMA coating additive mixture comprising
• a. one or more components selected from the group of components A2comprising C—H acidic protons in activated methylene or methine groups, and of substituted or unsubstituted triazoles components, and additionally
• b. one or more components selected from the group of non-triazole X—H group containing components D wherein X is N, P, O or S or wherein X is C as part of an acidic methyl CH3 group.