Method for purifying polyalkylsiloxanes and the resulting products
US5879649A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 1997 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | Sep 5, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2203/27
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention is directed to a purified polyalkylsiloxane composition having a boiling point, under atmospheric conditions, of less than about 250.degree. C. and containing high boiling impurities, including siloxanes and silanol-terminated siloxanes, that have boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of less than 14 ppm. The present invention is further directed to a method of producing a purified polyalkylsiloxane composition, having a boiling point, under atmospheric conditions, of less than about 250.degree. C., by distilling a polyalkylsiloxane starting material containing high boiling impurities having boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of at least 14 ppm, under conditions effective to produce a purified polyalkylsiloxane composition having a boiling point under atmospheric conditions of less than about 250.degree. C., and containing high boiling impurities, having boiling points, under atmospheric conditions, of greater than about 250.degree. C., in a total concentration of less than 14 ppm. In preferred embodiments, low boiling …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.