Polymerisation of cyclosiloxanes
US5883215A · kind A · utility
16Cited by
5References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1998 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Feb 20, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for the ring-opening polymerisation of cyclosiloxanes, which comprises contacting a cyclosiloxane with 1-500 ppm by weight of a phosphazene base, based on the weight of cyclosiloxane, in the presence of water, preferably 0.5-10 mols per mol of phospazene base. Also claimed is a process in which the cyclosiloxane is present together with an agent which inhibits catalyst activity of the phosphazene base, e.g. carbon dioxide or water, in which the polymerisation is initiated by reducing the effect of the inhibiting agent e.g. by heating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.