Composition crosslinkable by real michael addition (RMA) reaction

1. A crosslinkable composition crosslinkable by Real Michael Addition (RMA) reaction comprising:

a) Component(s) A having at least 2 acidic C—H donor groups in activated methylene or methine and having a pKa(A) between 10.5 and 14,

b) Component(s) B having at least 2 activated unsaturated acceptor groups, wherein a molar ratio R of acceptor groups to donor groups is between 3:1 to 1:6 and which component(s) B react with component(s) A by Real Michael Addition (RMA) to form a crosslinked network,

c) basic component(s) C being a salt of a basic anion X— from an acidic X—H group containing compound wherein X is N, P, O, S or C,

i) in an amount xc between 0.001 and 1 meq/(gr of components A, B, C, D),

ii) anion X— being a Michael Addition donor reactable with component B and

iii) anion X— is characterized by a pKa(C) of the corresponding acid X—H of more than two units lower than the pKa(A) of the majority component A and being lower than 10.5,

d) not including a composition comprising an ethylmalonate modified polyester based on neopentyl glycol and hexahydrophthalic anhydride, di-trimethylolpropane-tetraacrylate and tetrabutylammonium succinimide and ethylacetoacetate.

2. The crosslinkable composition according to claim 1 comprising:

component(s) D comprising one or more acidic X′—H groups wherein X′ is N, P, O, S or C,

i) X′ being a same or different group as group X in component C,

ii) the X′-anion being a Michael Addition donor reactable with component B,

iii) the pKa(D) of the X′—H group in component D being more than two units lower than the pKa(A) of the majority component A and being lower than 10.5,

iv) the equivalent ratio Rd/c of acidic X′—H groups in component D over basic anion X— in component C is between 1 and 5000%.

3. The crosslinkable composition according to claim 2 , wherein pKa(D) is equal to or higher than pKa(C).

4. The crosslinkable composition according to claim 2 , further comprising component(s) F comprising an acidic X″—H group wherein X″ is N, P, O, S or C

i) different from components A and D,

ii) F being a Michael addition donor reactable with component B.

5. The crosslinkable composition according to claim 1 , wherein the composition comprises less than 50 mole % relative to basic components C of other basic compound other than C that can initiate or catalyse the RMA crosslinking reaction.

6. The crosslinkable composition according to claim 2 , comprising:

a) Component(s) A in an amount xa between 5 and 95 wt % and

b) Component(s) B in an amount xb between 5 and 95 wt %, wherein xa plus xb is at least 40 wt %,

c) basic component(s) C in an amount xc between 0.001 and 1 meq/(gr total resin),

d) component(s) D in an amount xd such that the equivalent ratio Rd/c of acidic X′—H groups in component D over basic anion groups X— in component C is between 0% and 5000%,

e) component(s) F in an amount xf between 0 and 30 wt %,

wherein wt % is relative to total resin forming components A, B, C, D and F.

7. The crosslinkable composition according to claim 1 wherein at least 50 mole % of the RMA donor groups in component(s) A are from malonate or acetoacetate groups.

8. The crosslinkable composition according to claim 1 , in which the RMA acceptor components B are acryloyl or maleate groups or mixtures thereof.

9. The crosslinkable composition according to claim 2 , in which anions X— and X′— in components C and D have a lower Michael Addition reactivity towards component B than an anion of the majority component A by a factor of at least 3, but no more than 10,000.

10. The crosslinkable composition according to claim 2 , wherein

a) more than 50 mole % of RMA donor groups in components A are from malonate groups,

b) more than 50 mole % of the RMA acceptor groups in component B are from acryloyl groups,

c) component C is a benzotriazolide salt, a salt of 1,2,4-triazole or a salt of 1,3-cyclohexanedione,

d) component D is benzotriazole or a triazole, a 1,3-diketone, or an imid.

11. The crosslinkable composition according to claim 1 , wherein the composition comprises a solvent and wherein the amount of solvent is not higher than 55 wt %.

12. The crosslinkable composition according to claim 2 , wherein the anion X— in component C, and/or the X′ group in component D is an aza-acidic compound.

13. The crosslinkable composition according to claim 2 , wherein the anion X— from component C, and/or the X′ group in component D is a carbon-acidic compound.

14. The crosslinkable composition according to claim 2 , wherein the anion X— in component C, and/or the X′ group in component D are derived from an aromatic sulfonamide.

15. The crosslinkable composition according to claim 2 , wherein component C is a triazole and component D an imid or a 1,3 diketone.

16. A crosslinkable composition crosslinkable by Real Michael Addition (RMA) reaction comprising:

a) Component(s) A having at least 2 acidic C—H donor groups in activated methylene or methine and having a pKa(A) between 10.5 and 14,

b) Component(s) B having at least 2 activated unsaturated acceptor groups, wherein a molar ratio R of acceptor groups to donor groups is between 3:1 to 1:6 and which component(s) B react with component(s) A by Real Michael Addition (RMA) to form a crosslinked network,

c) basic component(s) C being a salt of a basic anion X— from an acidic X—H group containing compound wherein X is N, P, O, S or C,

iv) in an amount xc between 0.001 and 1 meq/(gr of components A, B, C, D),

v) anion X— being a Michael Addition donor reactable with component B and

vi) anion X— is characterized by a pKa(C) of the corresponding acid X—H of more than two units lower than the pKa(A) of the majority component A and being lower than 10.5,

d) component(s) D comprising one or more acidic X′—H groups wherein X′ is N, P, O, S or C,

i) X′ being a same or different group as group X in component C,

ii) the X′-anion being a Michael Addition donor reactable with component B,

iii) the pKa(D) of the X′—H group in component D being more than two units lower than pKa(A) of the majority component A and being lower than 10.5,

iv) the equivalent ratio Rd/c of acidic X′—H groups in component D over basic anion X— in component C is between 1 and 5000%.

17. The crosslinkable composition according to claim 16 , wherein pKa(D) is equal to or higher than pKa(C).

18. The crosslinkable composition according to claim 16 , wherein the composition comprises less than 50 mole % relative to basic components C of other basic compound other than C that can initiate or catalyze the RMA crosslinking reaction.

19. The crosslinkable composition according to claim 16 , comprising:

a) Component(s) A in an amount xa between 5 and 95 wt % and

b) Component(s) B in an amount xb between 5 and 95 wt %, wherein xa plus xb is at least 40 wt %,

c) basic component(s) C in an amount xc between 0.001 and 1 meq/(gr total resin),

d) component(s) D in an amount xd such that the equivalent ratio Rd/c of acidic X′—H groups in component D over basic anion groups X— in component C is between 0% and 5000%,

e) component(s) F in an amount xf between 0 and 30 wt %, wherein wt % is relative to total resin forming components A, B, C, D and F.

20. The crosslinkable composition according to claim 16 , wherein at least 50 mole % of the RMA donor groups in component(s) A are from malonate or acetoacetate groups and the RMA acceptor components B are acryloyl or maleate groups or mixtures thereof.

21. The crosslinkable composition according to claim 16 , in which anions X— and X′— in components C and D have a lower Michael Addition reactivity towards component B than an anion of the majority component A by a factor of at least 3, but no more than 10,000.

22. The crosslinkable composition according to claim 16 , wherein the anion X— in component C, and/or the X′ group in component D is an aza-acidic compound.

23. The crosslinkable composition according to claim 12 , wherein the aza-acidic compound comprises a molecule containing the N—H as part of a group Ar—NH—(C═O), —(C═O)—NH—(C═O)—, or a —NH—(O═S═O)— group, or a heterocycle in which the nitrogen of the N—H group is contained in a heterocyclic ring.