Latent catalyst for the production of polyurethane foam
The present technology provides a foam-forming composition comprising at least one polyol, at least one isocyanate, at least one copper catalyst composition, and at least one surfactant. The copper catalyst composition may comprise a copper (II) compound dissolved in a solvent. In one embodiment, the copper catalyst composition comprises (Cu(II)(acac) 2 ) dissolved in DMSO.
1. A method for forming a foam comprising:
(i) combining:
a) at least one polyol;
b) at least one isocyanate;
c) a catalyst composition comprising a copper (II) compound dissolved in a solvent chosen from a dialkyl sulfoxide, an N,N-dialkylalkanoamides, a phosphonate, an aromatic compound, an ether compound, or an organic carbonate;
d) at least one surfactant to form a mixture; and
(ii) curing the mixture of (i).
2. The method of claim 1 , where the copper (II) compound comprises copper (II) coordinated to a ligand chosen from a carboxylate, a diketonate, a salicylate, an organic salt, a halide, or a combination of two or more thereof.
3. The method of claim 1 , where the catalyst composition comprises (Cu(II)(acac) 2 ).
4. The method of claim 3 , where the solvent comprises DMSO.
5. The method of claim 1 , where the catalyst composition comprises a co-diluent chosen from a fatty acid, a vegetable oil, or a combination thereof.
6. The method of claim 1 , wherein the catalyst composition comprises two or more Cu(II) salts.
7. The method of claim 1 , wherein the catalyst composition comprises Cu(II)(acac) 2 and Cu(II)acetate 2 .
8. The method of claim 1 , where the mixture comprises a copper concentration of about 0.04 to about 10 parts per 100 parts polyol (pphr).
9. The method of claim 1 , comprising a co-catalyst (c′).
10. The method of claim 9 , wherein the co-catalyst is chosen from a tertiary amine.
11. The method of claim 10 , wherein the tertiary amine is chosen from triethylenediamine, 2-methyltriethylenediamine, N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′-tetramethylpropylenediamine, N,N,N′,N″,N″-pentamethyldiethylenetriamine, N,N,N′,N″,N″-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N′,N″,N″-pentamethyldipropylenetriamine, N,N,N′,N′-tetramethylhexamethylenediamine, bis(2-dimethylaminoethyl)ether, dimethylethanolamine, dimethylisopropanolamine, dimethylaminoethoxyethanol, N,N-dimethyl-N′-(2-hydroxyethyl)ethylenediamine, N,N-dimethyl-N′-(2-hydroxyethyl)propanediamine, bis(dimethylaminopropyl)amine, bis(dimethyl aminopropyl)isopropanolamine, 3-quinuclidinol, N,N,N′,N′-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, N-methyl-N′-(2-dimethylaminoethyl)piperazine, N,N′-dimetylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, N,N-dimethyhexanolamine, N-methyl-N′-(2-hydroxyethyl)piperazine, 1-(2-hydroxyethyl)imidazole, 1-(2-hydroxypropyl)imidazole, 1-(2-hydroxyethyl)-2-methylimidazole, 1-(2-hydroxypropyl)-2-methylimidazole, quinuclidine, 2-methylquinuclidine, or a combination of two or more thereof.
12. The method of claim 9 , wherein the catalyst composition and the co-catalyst are added separately in part (i).
13. The method of claim 9 , wherein the catalyst composition and the co-catalyst are part of a single composition.
14. The method of claim 9 , wherein the co-catalyst is present in an amount of from about 0.1 to about 10% by weight of the catalyst composition.
15. The method of claim 1 , further comprising combining a component (e) with components (a)-(d), where component (e) is chosen from a blowing agent, a chain extender, a crosslinker, a filler, a reinforcement, a pigment, a tint, a dye, a colorant, a flame retardant, an antioxidant, an antiozonant, a UV stabilizer, an anti-static agent, a biocide, a biostat, or a combination or two or more thereof.
16. The method of claim 1 , wherein step (i) comprises frothing components (a)-(d) to form a frothed mixture.