Method for decreasing the propensity for phase-out of the high molecular weight component of double metal cyanide-catalyzed high secondary hydroxyl polyoxypropylene polyols
US5958994A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Feb 25, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G2110/0008
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
During polyoxyalkylation in the presence of certain double metal cyanide catalysts, a very high molecular weight hydrophobic fraction, i.e. a "tail", is produced during preparation of high secondary hydroxyl polyols which is believed to contribute to foam collapse in polyurethane foam formulations. The processing latitude of such foams may be improved by altering the hydrophile/lipophile balance of the high molecular weight tail by oxyalkylating with a mixture of ethylene oxide and higher alkylene oxide during the greatest portion of total oxyalkylation such that essentially pure higher alkylene oxide is present in a terminal portion of oxyalkylation not exceeding 15 weight percent of total polyol weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.