Process for the manufacture of a crosslinkable composition
The invention relates to a process for the preparation of a RMA crosslinkable composition comprising at least one crosslinkable component comprising reactive components A and B each comprising at least 2 reactive groups wherein the at least 2 reactive groups of component A are acidic protons C—H in activated methylene or methine groups and the at least 2 reactive groups of component B are activated unsaturated groups C═C and base catalyst C and one or more N—H group containing reactivity moderating component D that are also a Michael addition donor reactable with component B under the action of catalyst C, characterized in that the one or more reactivity moderating components D have a melting temperature above 60° C. and is first dissolved in one or more crosslinkable components comprising reactive components A or B and the obtained pre-dissolved product is later mixed with other components of the RMA crosslinkable composition.
1. A moderator composition comprising: one or more RMA crosslinkable polymer components comprising one or more reactive components A comprising at least 2 acidic protons C—H in activated methylene or methine groups, and dissolved therein
one or more N—H groups containing reactivity moderating components D that are a Michael addition donor reactable with a reactive component B comprising activated unsaturated groups C═C under the action of a base catalyst C, said reactivity moderating components D having a melting temperature above 60° C. and less than 300 gr/ltr of an organic solvent,
said moderator composition being obtained by a process wherein the one or more RMA crosslinkable polymer components comprising the reactive component A are synthesized at a temperature above the melting temperature of the components D and the components D are added directly after the synthesis of said polymer and dissolved therein before cooling to a temperature below the melting temperature of the components D.
2. The moderator composition of claim 1 , consisting essentially of the RMA crosslinkable polymer components comprising the reactive components A, wherein the reactive components A are malonate, comprising between 0.5 and 5 wt % of a dissolved succinimide or a triazole moderator D relative to the total amount of the RMA crosslinkable components comprising the reactive components A and the components D and comprising less than 300 gr/ltr of an organic solvent.
3. The moderator composition of claim 1 , wherein the one or more RMA crosslinkable polymer components comprise a polymer chosen from the group of polyesters, polyurethanes, polyacrylates, epoxy resins, polyamides and polyvinyl resins, which contains the reactive components A in the main chain, pendant, terminal, or combinations thereof.
4. The moderator composition of claim 1 , wherein the one or more RMA crosslinkable polymer components comprising the reactive components A have a weight average molecular weight Mw of at least 250 gr/mol.
5. The moderator composition of claim 1 , wherein the one or more RMA crosslinkable polymer components comprising the reactive components A have a weight average molecular weight Mw between 300 and 5000 gr/mol.
6. The moderator composition of claim 1 , wherein the one or more RMA crosslinkable polymer components comprise a polyester comprising the reactive components A which are synthesised by forming a polyester polymer using the reactive components A as monomer or by transesterification of polyester polymer with the reactive components A.
7. The moderator composition of claim 1 , wherein the reactive components A are malonate or acetoacetate.
8. The moderator composition of claim 1 , wherein the one or more RMA crosslinkable polymer components comprise both malonate and acetoacetate in the same molecule.
9. The moderator composition of claim 8 , wherein more than 50% of the reactive components A are malonates.
10. The moderator composition of claim 1 , wherein the N—H group in the components D has a pKa (defined in aqueous environment) of at least one unit less than that of the C—H groups in the reactive components A.
11. The moderator composition of claim 1 , wherein the pKa of the N—H group in the components D is lower than 13.
12. The moderator composition of claim 1 , wherein the components D comprise a molecule containing the N—H as part of a group —(C═O)—NH—(C═O)—, or of a group —NH—(O═S═O)— or a heterocycle in which the nitrogen of the N—H group is contained in a heterocyclic ring.
13. The moderator composition of claim 1 , wherein the components D are selected from the group consisting of a substituted or unsubstituted succinimide, phthalimide, glutarimide, hydantoin, triazole, pyrazole, imidazole, uracil, and mixtures thereof.
14. The moderator composition of claim 1 , wherein the components D are present in an amount between 0.1 and 10 wt %, relative to the total amount of the RMA crosslinkable polymer components comprising the reactive component A and the components D.
15. The moderator composition of claim 1 , wherein the components D are present in such amount that the amount of N—H groups in the components D is no more than 30 mole %, relative to C—H donor groups from the reactive components A in the RMA crosslinkable polymer components.
16. The moderator composition of claim 1 , comprising less than 200 gr/ltr of an organic solvent.
17. The moderator composition of claim 1 , comprising less than 175 gr/ltr of an organic solvent.
18. A kit of parts comprising a first part comprising the moderator composition of claim 1 and a second part comprising a base catalyst C.