Polyurethanes made with copper catalysts
Polyisocyanate-based polymers are formed by curing a reaction mixture containing at least one polyisocyanate and at least one isocyanate-reactive compound having at least two isocyanate-reactive groups in the presence of a copper catalyst that contains at least one copper atom associated with a polydentate ligand that contains at least one nitrogen-containing complexing site.
1. A process for preparing a polyisocyanate-based polymer, comprising forming a reaction mixture containing at least one polyisocyanate, at least one isocyanate-reactive compound having at least two isocyanate-reactive groups and at least one copper catalyst, and then curing the reaction mixture to form a polymer, wherein the copper catalyst contains at least one copper atom associated with a polydentate organic ligand
having any of the structures
2. The process of claim 1 wherein the polyisocyanate-based polymer is a polyurethane, polyurea, or polyurethane-urea.
3. The process of claim 1 , wherein the reaction mixture further contains a blowing agent and a surfactant, and the polyisocyanate-based polymer is a foam.
4. The process of claim 1 , wherein the isocyanate-reactive compound includes a polyol having a molecular weight of from 800 to 12,000 and an average of from 1.8 to 2.5 hydroxyl groups per molecule, and the polyisocyanate-based polymer is a cast elastomer.
5. The process of claim 1 wherein the reaction mixture contains at least one additional catalyst.