Tin-free catalysis of silane-functional polyurethane crosslinkers
The present invention relates to a composition at least comprising A) an adduct of isocyanatosilanes with hydroxy-functional compounds and B) a tin-free catalyst, and also to a coating composition comprising at least the composition and to the use of the coating composition.
1. An aminosilane-free composition comprising
A) an adduct of an isocyanatosilane with a hydroxy-functional compound wherein the adduct A) comprises <0.05% free NCO groups,
B) a tin-free catalyst selected from the group consisting of alkylammonium halides, wherein the hydroxy-functional compound is selected from the group consisting of monoalcohols, diols, triols, tetrols and hydroxyl group-containing polymers having an OH number of from 10 to 500 mg KOH/gram and a number-average molar mass of from 250 to 6000 g/mol, and
C) a polyether siloxane copolymer,
wherein the hydroxyl group-containing polymers are selected from the group consisting of polyesters, polyethers, polyacrylates, polycarbonates, epoxy resins, FEVE (fluoroethylene vinyl ether), alkyds and polyurethanes, wherein the polyurethanes consist of polyols and diisocyanate monomers; and
wherein the amount of component A) is from 40 to 99% by weight and the amount of component B) is from 0.01 to 3% by weight, based in each case on the total composition.
2. The aminosilane-free composition according to claim 1 , wherein the isocyanatosilane is selected from the group consisting of 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyldimethoxyethoxysilane and/or 3-isocyanatopropyldiethoxymethoxysilane.
3. The aminosilane-free composition according to claim 2 , wherein the ratio of OH groups of the hydroxy-functional compounds to NCO groups of the isocyanatosilanes is from 1 to 1.
4. The aminosilane-free composition according to claim 1 , wherein the tin-free catalyst B) is selected from the group consisting of alkylammonium fluorides.
5. The aminosilane-free composition according to claim 1 , wherein the tin-free catalyst B) is tetramethylammonium fluoride, tetrapropylammonium fluoride, tetraethylammonium fluoride, tetrabutylammonium fluoride or a mixture thereof.
6. A one-component (1K) coating composition comprising at least the aminosilane-free composition according to claim 1 .
7. A one-component coating composition according to claim 6 which comprises at least one auxiliary and/or additive and/or at least one solvent.
8. The one-component coating composition according to claim 7 , wherein the at least one auxiliary and/or additive is selected from the group consisting of stabilizers, light stabilizers, pigments, levelling agents or rheological assistants, microgels, fumed silicon dioxide, inorganic or organic color pigments and/or effect pigments or mixtures of two or more thereof.
9. A composite comprising the one-component coating composition according to claim 6 wherein the composite comprises wood, plastic, glass or metal.
10. A coating comprising the one-component coating composition according to claim 6 .
11. The aminosilane-free composition according to claim 2 , wherein the tin-free catalyst B) is an alkylammonium fluoride.
12. A two-component (2K) coating composition comprising at least the aminosilane-free composition according to claim 1 .
13. A two-component coating composition according to claim 12 which comprises at least one auxiliary and/or additive and/or at least one solvent.
14. The two-component coating composition according to claim 13 , wherein the at least one auxiliary and/or additive is selected from the group consisting of stabilizers, light stabilizers, levelling agents or rheological assistants, microgels, fumed silicon dioxide, inorganic or organic color pigments and/or effect pigments or mixtures of two or more thereof.
15. A composite comprising the two-component coating composition according to claim 12 wherein the composite comprises wood, plastic, glass or metal.
16. A coating comprising the two-component coating composition according to claim 12 .
17. The aminosilane-free composition according to claim 1 , wherein the hydroxy-functional compound is selected from the group consisting of a diol, triol and tetrol.
18. The aminosilane-free composition according to claim 1 , wherein the hydroxy-functional compound is a diol or a triol.