Evonik Operations Gmbh

Jan Caßens

Wilfried Knott

Horst Dudzik

Frauke Henning

Dagmar Windbiel

Michael Ferenz

Michael Fiedel

Philippe Favresse

Ralf Meier

Luca Cameretti

André Brötzmann

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.

Process for purifying acetoxysiloxanes

The invention relates to a method for producing cyclododecanone (CDON). During the production, contaminated cyclododecane (CDAN) is produced. This can be separated from CDON by distillation (CDAN-containing fraction). The separation of CDAN and impurities such as 13-oxabicyclo [7.3.1]tridecane occurs by crystallizing out CDAN from the CDAN-containing fraction.

Process for preparing cyclododecanone

Described is a process for producing preferably trifluoromethanesulfonic acid-acidified, end-equilibrated, acetoxy-bearing siloxanes which comprises reacting cyclic siloxanes, in particular comprising Dand/or D, and/or cyclic branched siloxanes of the D/T type with acetic anhydride using preferably trifluoromethanesulfonic acid as catalyst and with addition of acetic acid, wherein the cyclic branched siloxanes of the D/T type are mixtures of cyclic branched siloxanes of the D/T type which contain not only siloxanes comprising D and T units but also siloxanes comprising Q units.

Process for producing acetoxy-bearing siloxanes

Branched SiOC-linked polyethersiloxanes have the following formula (I) where Ris an alkyl radical having 1 to 4 carbon atoms or a phenyl radical, but preferably 90% of the radicals Rare methyl radicals; b has a value of from 1 to 10; a has a value of from 1 to 200, preferably 10 to 100, a value of from 3 to 70 when b is &#x2265;1 and &#x2264;4, or a value of from 3 to 30 when b is &#x3e;4; and Rdenotes identical or different polyether radicals, but at least one radical Ris a structural element radical of formula (II): where p=at least 2, preferably p=2-6, particularly preferably p=3.

SiOC-based polyethersiloxanes

Described is a process for producing preferably trifluoromethanesulfonic acid-acidified, end-equilibrated, acetoxy-bearing siloxanes which comprises reacting cyclic siloxanes, in particular comprising Dand/or D, and/or cyclic branched siloxanes of the D/T type with acetic anhydride using preferably trifluoromethanesulfonic acid as catalyst and with addition of acetic acid, wherein the cyclic branched siloxanes of the D/T type are mixtures of cyclic branched siloxanes of the D/T type which may contain not only siloxanes comprising D and T units but also siloxanes comprising Q units.

Described is a process for producing trifluoromethanesulfonic acid-acidified, end-equilibrated, acetoxy-bearing siloxanes which comprises reacting cyclic siloxanes, in particular comprising Dand/or D, and/or cyclic branched siloxanes of the D/T type with acetic anhydride using trifluoromethanesulfonic acid as catalyst and with addition of acetic acid.

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Datteln, Germany

Jan Caßens