Method for preparing polyorganosiloxanes by hydrolyzing organohalosilanes
US6326452A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 2000 |
| Grant date | Dec 4, 2001 |
| Priority date | — |
| Expiry date | May 10, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention concerns a method for preparing polyorganosiloxanes by hydrolysing organohalosilanes of formula (I) R.sub.a R.sup.1.sub.b SiX.sub.c, in which R, R.sup.1 are identical or different radicals and represent hydrogen or linear or branched C1-C6 alkyls, aryls, alkylaryls or aralkyla X represents a halogen, and a+b+c=4 and 0<c<4; characterised in that it consists essentially in carrying out: at three successive hydrolysing steps (1), (2), (3), wherein the reaction medium is capable of exerting an increasing hydrolysing force on the organohalosilane (I), and optionally, at least a coalescing step (4); in that step (1) is a hydrolysis under pressure in the presence of an aqueous saturate hydrogen halide solution S.sub.1, at the reaction medium pressure and temperature; and in that the advanced hydrolysing step (3.sub.1) brings into the reaction medium a water supply in the form of water free from or practically free from dissolved solutes and/or by means of aqueous hydrogen halide solution(s).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.