Method for continuously producing low equivalent weight polyols using double metal cyanide catalysts
US9074044B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 2010 |
| Grant date | Jul 7, 2015 |
| Priority date | — |
| Expiry date | Dec 23, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G65/2696
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Polyether polyols having equivalent weights of up to 500 are continuously prepared in the presence of a double metal cyanide catalyst. A first step of the reaction is performed at a temperature of at least 150° C., while controlling the hydroxyl content and unreacted alkylene oxide content of the reaction mixture to within certain ranges. A portion of that reaction mixture is withdrawn and permitted to react non-isothermally to consume the unreacted alkylene oxide. This process is highly efficient, does not result in catalyst deactivation, as is commonly seen in previous processes, and does not produce a significant ultra high molecular weight tail.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.