CROSSLINKABLE COMPOSITION CROSS-LINKABLE BY REAL MICHAEL ADDITION REACTION AND RESINS FOR USE IN SAID COMPOSITION
An RMA crosslinkable composition having at least one crosslinkable component including reactive components A and B each including at least 2 reactive groups, the at least 2 reactive groups of component A being 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 a base catalyst (C) which reactive components A and B crosslink by Real Michael Addition (RMA) reaction under action of the base catalyst, characterised in that the at least one crosslinkable component including reactive components A and B in the composition have a total hydroxy number of less than 60, preferably less than 40 and more preferably less than 20 mg KOH/g solids. Further, specific resins A and B having a low hydroxy number for use in RMA cross-linkable compositions and a process for the manufacture thereof.
1 ) An 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 C—H acidic protons in activated methylene or methine groups, and the at least 2 reactive groups of component B are C═C activated unsaturated groups and a base catalyst C, which reactive components A and B crosslink by Real Michael Addition reaction under action of the base catalyst, wherein the at least one crosslinkable component comprising reactive components A and B in the composition has a total hydroxy number of less than 60 mg KOH/g solids.
2 ) The RMA crosslinkable composition according to claim 1 , wherein the at least one crosslinkable component comprising reactive components A and B in the composition has a total hydroxy number less than 20 mg KOH/g solids.
3 ) The RMA crosslinkable composition according to claim 1 , wherein the catalyst C is a carbonate salt according to formula X + ROCO 2 − , wherein X + is a non-acidic cation, and R is hydrogen or a substituted or unsubstituted alkyl, aryl, or aralkyl group.
4 ) The RMA crosslinkable composition according to claim 1 , wherein X + is quaternary ammonium or phosphonium.
5 ) The RMA crosslinkable composition according to claim 1 , wherein the crosslinkable component comprising reactive component A is a polymer comprising an average of 2 to 20 active C—H functions per molecule.
6 ) The RMA cross-linking composition according to claim 1 , wherein more than 50% of the reactive components A in the crosslinkable component are malonate groups.
7 ) The RMA crosslinkable composition according to claim 1 , wherein the component B comprises an unsaturated acryloyl or maleate functional group.
8 ) The RMA crosslinkable composition according to claim 1 , comprising:
a. between 5 and 95 wt % of a crosslinkable component comprising component A with at least 2 acidic protons C—H in activated methylene or methine, and
b. between 5 and 95 wt % of a crosslinkable component comprising component B with at least 2 activated unsaturated groups, wt % relative to the total weight of the crosslinkable composition 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,
wherein the sum of the above-mentioned components is 100 weight percent and wherein the at least one crosslinkable component comprising reactive components A and B in the composition has a total hydroxy number of less than 60 mg KOH/g solids.
9 ) The RMA crosslinkable composition according to claim 8 , wherein the catalyst system C contains or is able to generate a basic catalyst capable of activating the RMA reaction between components A and B, at levels of 0.0001 and 0.5 meq/g solid components.
10 ) The RMA crosslinkable composition according to claim 8 , further comprising 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 C, N, P, O or S.
11 ) The RMA crosslinkable composition according to claim 8 , wherein component D is present in quantities of at least 50 mole % relative to base generated by component C, and less than 30 mole % of C—H active groups from component A.
12 ) The RMA crosslinkable composition according to claim 8 , further comprising between 0.1 and 80 wt % of an organic solvent, which contains at least lwt % of a primary alcohol and at least 0.1-10 wt % water.
13 ) The RMA crosslinkable composition according to claim 8 , wherein the at least one crosslinkable component comprising reactive components A and B in the composition has a total hydroxy number less than 20 mg KOH/g solids.
14 ) A kit of parts for the manufacture of the crosslinkable composition according to claim 1 , comprising a part 1 comprising the cross-linkable components comprising reactive components A and/or B but no C, and part 2 comprising component C.
15 ) A polymeric or oligomeric resin A, for use in a RMA crosslinkable composition according to claim 1 , comprising one or more reactive components A having a structure according to formula 1:
wherein R is hydrogen or an alkyl, aralkyl or aryl substituent and Y and Y′ are same or different alkyl, aralkyl or aryl (R*), alkoxy (—OR*) groups or a polymer backbone or wherein the —C(═O)—Y and/or —C(═O)—Y′ is replaced by CN or phenyl and which polymeric or oligomeric resin A has a hydroxy number of less than 60 mg KOH/g solids, wherein the polymeric or oligomeric resin is a polyester, polyether, polyepoxy, polyurethane or polycarbonate, comprising reactive component A.
16 ) The resin A according to claim 15 , wherein more than 50% of the reactive components A in the crosslinkable component are malonate groups.
17 ) The resin A according to claim 15 , having a number molecular weight between 100-20000 gr/mol, and an equivalent weight per reactive component A of 100-2000 gr/mol, and an acid number less than 4 mg KOH/gr.
18 ) A polymeric or oligomeric resin B for use in a RMA cross-linkable composition according to claim 1 comprising one or more reactive components B comprising C═C activated unsaturated groups, and which polymeric or oligomeric resin has a hydroxy number of less than 60 mg KOH/g solids, wherein the polymeric or oligomeric resin B is a polyester, polyether, polyepoxy, polyurethane or polycarbonate comprising reactive component B.
19 ) The resin B according to claim 18 , having a number molecular weight between 300 and 20000 gr/mol, having a equivalent weight per reactive component A or B of 100-2000 gr/mol, an acid number less than 4 mg KOH/gr.
20 ) Method for preparation of an 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 C—H acidic protons in activated methylene or methine groups, and the at least 2 reactive groups of component B are C═C activated unsaturated groups and a base catalyst C, which reactive components A and B crosslink by Real Michael Addition reaction under action of the base catalyst, wherein the at least one crosslinkable component is a resin A, which resin A is a polymeric or oligomeric resin comprising one or more reactive components A having a structure according to formula 1:
wherein R is hydrogen or an alkyl, aralkyl or aryl substituent and Y and Y′ are same or different alkyl, aralkyl or aryl (R*), alkoxy (—OR*) groups or a polymer backbone or wherein the —C(═O)—Y and/or —C(═O)—Y′ is replaced by CN or phenyl and which polymeric or oligomeric resin A has a hydroxy number of less than 60 mg KOH/g solids, wherein the polymeric or oligomeric resin is a polyester, polyether, polyepoxy, polyurethane or polycarbonate; or
wherein the at least one crosslinkable component is a resin B, which resin B is a polymeric or oligomeric resin comprising one or more reactive components B comprising C═C activated unsaturated groups, and which polymeric or oligomeric resin has a hydroxy number of less than 60 mg KOH/g solids, wherein the polymeric or oligomeric resin B is a polyester, polyether, polyepoxy, polyurethane or polycarbonate, or
wherein the at least one crosslinkable component is a mixture of resin A and resin B.
21 ) Method for the manufacture of coating compositions, films or inks comprising: providing the crosslinking composition according to claim 1 .
22 ) Coating composition comprising the RMA crosslinkable composition according to claim 1 , and further comprising one or more coating additives such as pigments, co-binders, or solvents.