| 摘要 |
The invention concerns a method for preparing polyorganosiloxanes by hydrolysing organohalosilanes of formula (I) Ra R<1>b SiXc, in which R, R<1> are identical or different radicals and represent hydrogen or linear or branched C1-C6 alkyls, aryls, alkylaryls or aralkyls, 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 organohalosilanes (I), and optionally, at least a coalescing step (4); in that step (1) is a hydrolysis under pressure in the presence of an aqueous saturated hydrogen halide solution S1, at the reaction medium pressure and temperature; and in that the advanced hydrolysing step (31) 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). |
