摘要 |
<p>A method for preparing polyorganosiloxanes by hydrolysing organohalosilanes of formula (I) RaR1bSiXc, wherein each of R and R1, which are the same or different, is hydrogen or straight or branched C¿1-6? alkyl, aryl, alkylaryl or aralkyl, X is a halogen, and a + b + c = 4 and 0 < c < 4. The method essentially comprises a series of at least three hydrolysis steps (1, 2, 3) in which the reaction medium is capable of exerting an increasing hydrolysing force on the organohalosilanes (I), and optionally at least one coalescence step (4). Step (1) involves pressure hydrolysis in the presence of a saturated aqueous hydrogen halide solution S1 and at the same temperature and pressure as the reaction medium.</p> |