Process for reducing fluoride levels in poly(tetramethylene ether) glycol
US4954658A · kind A · utility
0Cited by
4References
20Claims
0Family size
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Key dates
| Filing date | Sep 14, 1989 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Sep 14, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G65/20
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for reducing fluoride levels in PTMEG by heating aqueous PTMEG having an undesired level of fluoride (80'600 ppm) to a temperature in the range between about 200.degree. and 300.degree. C. for a period of time sufficient to reduce the fluoride content of said PTMEG. Preferably, heating is carried out with agitation to a temperature between about 225.degree. and about 275.degree. C. for about 1 minute to about 8 hours in the presence of an aqueous base, most preferably 240.degree. to 250.degree. C. in presence of aqueous lime.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.