Purification of polyols prepared using double metal cyanide complex catalysts
US4877906A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 25, 1988 |
| Grant date | Oct 31, 1989 |
| Priority date | — |
| Expiry date | Nov 25, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G65/2663
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for removing double metal cyanide complex catalyst from polyether polyols is disclosed which uses alkali metal compounds and phosphorous compounds to precipitate the residual catalyst, which may then be removed by filtration. In one embodiment, a propylene oxide polyol is treated with sodium metal dispsersion, capped with ethylene oxide, treated with magnesium silicate, and then filtered to remove at least a portion of the catalyst. Substantially complete catalyst removal is then achieved by treating the polyol with hypophosphorous or phosphorous acid to precipitate the remaining solubilized double metal cyanide complex catalyst residue, neutralizing the excess acid with magnesium silicate, and filtering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.