Patent ID: 6359097
Filing Date: 2002-03-19
Classification: C07F,C08G

Abstract:
A process for the preparation of a statistical, sequenced or block polyorganosiloxane of the following average formula: wherein:Y is a methoxy, ethoxy, propoxy, or isopropoxy radical, W is hydrogen or a monovalent radical having from 2 to 30 carbon atoms and optionally substituted with S, O, or halogen atoms, R are identical or different and are monovalent hydrocarbon radicals selected from the group consisting of linear alkyls having from 1 to 6 atoms, branched alkyls having from 1 to 6 atoms, and aryls, Z is R or Y, m and n, represent positive whole or decimal numbers and p and q represent 0 or positive or decimal numbers. 100&gE;m+n+p+q&gE;3, 1&lE;m&lE;50, 0&lE;p&lE;10, and 0&lE;q&lE;20, said process comprising the steps of:1a) reacting with an alcohol in the presence of a catalyst whose active element is a transition metal, according to a dehydrogenation/condensation mechanism, a starting polyorganosiloxane of the formula: â€ƒwherein: R are identical or different and are monovalent hydrocarbon radical selected from the group consisting of linear alkyls having from 1 to 6 atoms, branched alkyls having from 1 to 6 atoms, and aryls, Zâ€² are identical or different and are R or hydrogen, and v=m+n+q, with the proviso that, if v=0, then p&gE;1 and the two Zâ€² radicals are hydrogen; then 1b) reacting the polyorganosiloxane obtained in step 1a) with an olefinic compound carrying one &pgr; bond to carry out a hydrosilylation reaction exclusively catalysed by the catalyst used in step 1a), using step 1a) alcohol as a solvent; and 2) recovering said functionalized polyorganosiloxane.