Ytterbium(III) acetylacetonate as a catalyst for the preparation of aliphatic oligocarbonate polyols
View Patent ↗Ytterbium(III) acetylacetonate is used as a catalyst for the preparation of aliphatic oligocarbonate polyols by transesterification of at least one organic carbonate with at least one aliphatic polyol.
1. A process for the production of an aliphatic oligocarbonate polyol having a number average molecular weight of from 500 to 5000 g/mol comprising reacting an aliphatic polyol with an organic carbonate in the presence of an ytterbium(III) acetylacetonate transesterification catalyst.
2. The process of claim 1 in which the organic carbonate is a dimethyl carbonate, a diethyl carbonate, a diphenyl carbonate or any combination thereof.
3. The process of claim 1 in which the organic carbonate is a dimethyl carbonate.
4. The process of claim 1 in which the aliphatic polyol is the product of an addition reaction between (a) an aliphatic diol and (b) a lactone or epoxide.
5. The process of claim 1 in which the aliphatic polyol is 1,6-hexanediol, a ring-opening product of 1,6-hexanediol and ε-caprolactone or a mixture thereof.
6. The process of claim 1 in which the catalyst concentration is from 0.01 ppm to 10000 ppm, based on the total mass of educts utilized.
7. The process of claim 1 in which the methylether content of the aliphatic oligocarbonate polyol is less than or equal to 0.2 wt. %.
8. An ytterbium-containing oligocarbonate diol having a number average molecular weight of from 500 to 5000 g/mol produced by the process of claim 1 .
9. An NCO-terminated prepolymer produced by reacting a stoichiometric excess of an organic (poly)isocyanate with the ytterbium-containing oligocarbonate diol of claim 8 .