Double-metal cyanide catalysts for preparing polyether polyols
The invention is directed to a double-metal cyanide catalyst for the preparation of a polyether polyol by the polyaddition of an alkylene oxide on to a starter compound containing active hydrogen atoms, wherein the DMC catalyst comprises a) at least one double-metal cyanide compound; b) at least one organic complexing ligand which is not a polyether, polyester, polycarbonate, polyalkylene glycol sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, α,β-unsaturated carboxylic acid ester or ionic surfactant compound; c) at least one polyether; and d) at least one polyester, polycarbonate, polyalkylene glycol sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, α,β-unsaturated carboxylic acid ester or ionic surfactant compound. The catalyst of the present invention has increased activity in the preparation of a polyether polyol.
1. A double-metal cyanide catalyst comprising:
a) at least one double-metal cyanide compound;
b) at least one organic complex ligand which is not a polyether, polyester, polycarbonate, polyakylene glycol sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, α,β-unsaturated carboxylic acid ester or ionic surfactant compound;
c) at least one polyether; and
d) at least one polyester, polycarbonate, polyalkylene glycol, sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, α,β-unsaturated carboxylic acid ester or ionic surfactant compound.
2. The double-metal cyanide catalyst according to claim 1 , further comprising water and/or a water-soluble metal salt.
3. The double-metal cyanide catalyst according to claim 1 , wherein the double-metal cyanide compound is zinc hexacyanocobaltate (III).
4. The double-metal cyanide catalyst according to claim 1 , wherein the organic complex ligand is an alcohol, aldehyde, ketone, ether, ester, amide, urea, nitrile, sulfide and/or a mixture thereof.
5. The double-metal cyanide catalyst according to claim 1 , wherein the organic complex ligand is tert.-butanol.
6. The double-metal cyanide catalyst according to claim 1 , wherein the double-metal cyanide catalyst contains up to about 80 wt. %, based on the total weight of the double-metal cyanide catalyst, of a mixture of c) and d).
7. A process for the preparation of a double-metal cyanide catalyst according to claim 1 , comprising the steps of:
(a) reacting, in aqueous solution,
(I) at least one metal salt,
(II) with at least one metal cyanide salt, in the presence of
(III) an organic complex ligand, which is not a polyether, polyester, polycarbonate, polyalkylene glycol sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, α,β-unsaturated carboxylic acid ester or ionic surfactant compound; to form a suspension; and
(b) treating the suspension with at least one polyether and at least one polyester, polycarbonate, polyalkylene glycol sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, α,β-unsaturated carboxylic acid ester or ionic surfactant compound.
8. A process according to claim 7 , further comprising the steps of:
(c) isolating the catalyst from suspension after (b);
(d) washing the isolated catalyst; and
(e) drying the isolated catalyst.