Reducing low molecular weight cyclic organosiloxanes in a recirculating process stream
US6180811A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1998 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | Dec 22, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F7/21
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for continuously reducing the amount of cyclic organosiloxane in a recirculating process stream. The process comprises washing a process stream in a wash step to reduce chloride content of the process stream, distilling the process stream into a low-boiling fraction comprising low molecular weight cyclic organosiloxanes and an inert solvent and a high-boiling fraction comprising linear organosiloxanes and high molecular weight cyclic organosiloxanes, and reequilibrating the overhead low-boiling fraction in the presence of a reequilibration catalyst to form a reequilibration mixture comprising high molecular weight cyclic organosiloxanes and the inert solvent, and recycling the reequilibration mixture to the wash step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.