| 摘要 |
A method of hydrolysis/condensation by acid catalysis of silanes with hydrolyzable groups, preferably halosilanes and most preferably chlorosilanes in a polyphase (preferably biphase) medium by placing the silanes in the presence of water, buffer and neutralizer, subjecting to intensive stirring, separating the aqueous and organic phases to recover the hydroxylated polyorganosiloxanes. Stirring is carried out using means capable of producing within the reaction medium a stirring effect at least equivalent to that given by the shear produced by a rotor with peripheral speed at least 8 m.s-1 more preferably 10 m.s-1 and most preferably 15-30 m.s-1 and permitting the formation of droplets of organic phase with d32 below 500 mum. The ratio by weight of silanes and the aqueous phase is 0.05 or more, more preferably 0.10 or more and most preferably 0.5-2.0. An Independent claim is included for a device for implementing the method consisting of: (1) one or more hydrolysis/condensation reactors; (2) means of intensive stirring; (3) means of feeding the reactor(s) with organic phase; (4) means of feeding the reactor with aqueous phase; (5) means of withdrawal from the biphase reaction medium after hydrolysis/condensation; (6) means of maintaining the temperature; (7) an equipment for phase separation . |
