Process for the preparation of polyorganosiloxanes by hydrolysis of organohalosilanes
US5783718A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1997 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Jun 11, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G77/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention relates to a process for the preparation of polyorganosiloxanes by hydrolysis of organohalosilanes of formula (I) R.sub.a R.sup.1.sub.b SiX.sub.c, wherein R and R.sup.1 identical or different, are an hydrogen atom or a linear or branched C.sub.1 -C.sub.6 alkyl, aryl, alkylaryl or aralkyl group; X is a halogen atom; and a+b+c=4 and 0<c<4; said process comprising the steps of carrying out three or more successive hydrolysis steps (1), (2), (3), in which the reaction medium is capable of exerting an increasing hydrolysing force on the organohalosilanes (I), wherein step (1) is a hydrolysis under pressure in the presence of an aqueous solution S.sub.1 of saturated hydrogen halide, at the pressure and temperature of the reaction medium; and, optionally, carrying out one or more coalescence step (4).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.