Anhydrous process for preparation of polyorganosiloxanes.

摘要

Method comprises (A) contacting an anhydrous mixt. comprising a Cl end-terminated polyorganosiloxane of the formula Cl(R2SiO)xSiR2Cl (I) and an organodisiloxane of the formula R3SiOSiR3 (II) with a rearrangement catalyst to facilitate a Cl and organosiloxy exchange to form an organochlorosilane; (B) continuously removing the organochlorosilane from the process; and (C) recovering polyorganosiloxanes of the formula R3SiO(R2SiO)ySiR3 (III). In the formulae R is H, 1-20C alkyl, 4-20C cycloalkyl, 2-20C alkenyl and aryl (esp H or Me); x is 1-1000 (esp 10-200) and y is 1-1001.