Method for the production of polymethylvinylsiloxane resins with recycling of volatile oligoorganosiloxanes
US7750077B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 26, 2004 |
| Grant date | Jul 6, 2010 |
| Priority date | — |
| Expiry date | Sep 15, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/20
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention relates to the field of silicon resins, particularly polymethylvinylsiloxane resins. The invention more specifically relates to a method for the production of polymethylvinylsiloxane resins comprising at least two different types of siloxy motifs R3SiO1/2 (motif M) and SiO4/2 (motif Q, optionally QOH), said method comprising the following steps: a) producing a siloxane resin comprising motifs Q by acidic hydrolysis of a siloxane resin precursor, preferably an alkaline silicate; b) functionalizing the siloxane resin obtained in step a) with halogenosilanes in the presence of an apolar solvent, the functionalizing generating sub-products including volatile oligosiloxanes (silox); c) recovering silox produced in step b) in a solution in the apolar solvent; and d) subjecting the resin functionalized in step b) to rearrangement with the aid of a strong base in order to eliminate the silanols, wherein at least a part of the silox produced during step b) and recovered in step c) is recycled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.