Crosslinkable composition crosslinkable with a latent base catalyst
The present invention relates to a crosslinkable composition comprising at least one crosslinkable component crosslinkable by a latent base crosslinking catalyst comprising a substituted carbonate salt according to formula 1 wherein X + represents a cation and wherein R is hydrogen, alkyl, aryl or aralkyl group, and wherein the crosslinkable composition comprises 0.1-10 wt %, preferably 0.1-5, more preferably 0.2-3 and most preferably 0.5-1.5 wt % water (relative to total weight of the crosslinkable composition). The invention further relates to a coating composition comprising the crosslinkable composition according to the invention, a novel catalyst composition and to the use of said catalyst composition according to the invention as a latent base crosslinking catalyst in coating compositions, preferably in RMA crosslinkable compositions.
1. A crosslinkable polymer coating composition comprising at least one crosslinkable component crosslinkable by a latent base crosslinking catalyst said crosslinkable polymer coating composition comprising a latent base catalyst being a substituted carbonate salt according to formula 1
wherein X + represents a non-acidic cation and wherein R is hydrogen, alkyl, aryl or aralkyl group, and wherein the crosslinkable composition comprises 0.1-10 wt % water relative to total weight of the crosslinkable composition.
2. The crosslinkable composition according to claim 1 wherein the at least one crosslinkable component comprises reactive components crosslinkable by Real Michael Addition (RMA) upon deblocking of the latent base catalyst by evaporation of carbon dioxide.
3. The crosslinkable composition according to claim 1 , wherein the latent crosslinking catalyst is utilized in an amount ranging between 0.001 and 0.3 meq/g solids (meq/g solids defined as moles latent base relative to the total dry weight of the crosslinkable composition).
4. The crosslinkable composition according to claim 1 , wherein the amount of water is chosen in an effective amount to increase gel time of the crosslinkable composition with at least 15 minutes or at least 10% compared to the same composition without water.
5. The crosslinkable composition according to claim 1 having a solids content between 55 and 100% solvent having a dry to touch time at room temperature between 5 to 120 min and a gel time of at least 3 hours at room temperature.
6. The crosslinkable composition according to claim 1 further comprising an organic solvent.
7. The crosslinkable composition according to claim 6 , wherein at least part of the solvent is an alcohol solvent.
8. The crosslinkable composition according to claim 7 , wherein the alcohol is present in an amount of at least 1 wt % relative to the total weight of the crosslinkable composition.
9. The crosslinkable composition according to claim 7 , wherein the alcohol is a primary mono-alcohol having 1 to 20 carbon atoms.
10. The crosslinkable composition according to claim 1 , wherein the cation in the latent crosslinking catalyst is a quaternary ammonium or phosphonium carbonate salt according to formula 3,
wherein Y represents N or P, wherein each R′ is a same or different alkyl, aryl or aralkyl group or a polymer, R is hydrogen, alkyl, aryl or aralkyl group or a polymer or bridged to form a ring structure with R′.
11. The crosslinkable composition according to claim 10 wherein R is an alkyl or aralkyl group.
12. The crosslinkable composition according to claim 10 further comprising a compound (II) with the formula RO—C(═O)O—R wherein R is the same as R in formula 1 or 3 but not H.
13. The crosslinkable composition according to claim 12 , the molar ratio of compound II to the mole of carbonate in the catalyst is 0.01-50.
14. The crosslinkable composition according to claim 12 wherein R is alkyl having 1-4 carbon atoms.
15. A crosslinkable polymer composition for use in the preparation of a 2K crosslinkable coating 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) said crosslinkable polymer composition comprising a latent base catalyst C, wherein the at least one crosslinkable component crosslink by Real Michael Addition (RMA) reaction upon deblocking of latent base catalyst C by evaporation of carbon dioxide, wherein the latent base catalyst C is a substituted carbonate salt according to formula 1
wherein X represents a non-acidic cation and wherein R is hydrogen, an alkyl, or aralkyl group and which comprises 0.1-10 wt % water (relative to total weight of the crosslinkable composition).
16. A crosslinkable polymer composition for use in a 2K crosslinkable coating composition according to claim 15 said crosslinkable composition comprising
a. a malonate containing compound as reactive component A.
b. an unsaturated acryloyl, maleate or fumarate functional compound as reactive component B.