Process for the production of polysilalkylenesiloxanes
US8586690B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2010 |
| Grant date | Nov 19, 2013 |
| Priority date | — |
| Expiry date | Nov 2, 2030 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/50
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to a process for the production of an intermediate siloxane monomer and use of said monomer to produce high molecular weight linear polysilalkylenesiloxanes. The siloxane monomer is prepared by ring opening polymerization of a cyclic monomer of the structure in the presence of an acidic or basic ring opening polymerization catalyst; to form a mixture of siloxane monomers and linear oligomers. The linear oligomers are then extracted and discarded before a further step of ring opening polymerization using the aforementioned intermediate siloxane monomer mixture as the starting material. The second polymerization step is undertaken at a temperature within the melting point range of said siloxane monomer mixture. The intermediate, final product and methods of their manufacture are described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.