Process for purifying acetoxysiloxanes
AssigneeEvonik Operations GmbH
InventorsWilfried Knott, Dagmar Windbiel, Horst Dudzik, Frauke Henning, Jan Caßens
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Abstract
Processes are described for purifying acidic, preferably superacidic, in particular trifluoromethanesulfonic acid-acidified, end-equilibrated acetoxysiloxanes, wherein the acidic, preferably superacidic, in particular trifluoromethanesulfonic acid-acidified, acetic anhydride-containing and optionally acetic acid-containing equilibrated, preferably end-equilibrated acetoxysiloxane, which is optionally dissolved in an inert solvent, is contacted with a base, the precipitate is filtered off thereafter and then the filtrate obtained is optionally purified by distillation.
Claims9
A process for purifying acidic equilibrated acetic anhydride-containing acetoxysiloxane, wherein
- (a) the acidic acetic anhydride-containing equilibrated, acetoxysiloxane, which is optionally dissolved in an inert solvent, is contacted with a base, wherein the acetoxy siloxane contains acetic acid of from 0.4 to 3.5 per cent by weight, based on the acetoxysiloxane;
- (b) a precipitate is filtered off;
- and
- (c) the filtrate obtained is purified by distillation.
Dependencies are inferred from the claim text.