Evonik Operations Gmbh

Evonik Degussa Gmbh

Evonik Goldschmidt Corporation

Goldschmidt Ag

Goldschmidt Gmbh

Horst Dudzik

Wilfried Knott

Frauke Henning

Philippe Favresse

Dagmar Windbiel

Klaus-Dieter Klein

Jan Caßens

Michael Ferenz

Dietmar Schaefer

Michael Fiedel

Roland Hubel

Annegret Terheiden

André Brötzmann

Frank Schubert

Georg Burkhart

Markus Hallack

Berend-Jan De Gans

Carsten Schiller

Hardi Doehler

Florian Düllmann

Volker Möhring

Martin Glos

Christian Eilbracht

Helmut Lammerting

Rüdiger Landers

Andrea Lohse

Hardi Döhler

Olga Fiedel

Sadik Amajjahe

Daniela Hermann

Wolfgang Hiersche

Isabelle Denise Wessely

Ute Hesse

Juergen Droese

Jurgen Dröse

Gabriele Platte

Jan Cassens

Volker Moehring

George Burkhart

Dagmar Schnell

Florian Gaber

Stephan Hofmann

Eva Emmrich

Phillippe Favresse

Hardi Dohler

Curable condensation compounds are obtainable by a reaction of non-end-equilibrated acetoxy group-bearing siloxanes with at least one alkoxy-functional polysiloxane, in the presence of a catalyst.

Curable condensation compounds based on alkoxy-functional polysiloxanes

Process for producing PU foams by reacting at least one polyol component with at least one isocyanate component in the presence of one or more catalysts that catalyse the isocyanate-polyol and/or isocyanate-water and/or isocyanate trimerization reactions, and optionally one or more chemical or physical blowing agents, with use of SiOC-linked, linear polydialkylsiloxane-polyoxyalkylene block copolymers having repeat (AB) units, obtainable through the reaction of polyether diols with equilibrated α,ω-diacetoxypolydialkylsiloxanes, wherein a sufficient amount of the SiOC-linked, linear polydialkylsiloxane-polyoxyalkylene block copolymers having repeat (AB) units is added such that the proportion by mass of said component based on the finished PU foam is from 0.0001% to 10% by weight, preferably 0.01% to 6% by weight, especially 0.05% to 5% by weight.

Production of PU foams

Curable condensation compounds are useful, obtainable by the reaction of end-equilibrated acetoxy group-bearing siloxanes with at least one alkoxy-functional polysiloxane, in the presence of a catalyst.

Process for producing endcapped, liquid siloxanes having chain lengths of greater than 3 silicon atoms from end-of-life silicones, especially from silicone elastomers and/or silicone rubbers, by acid-catalysed depolymerization thereof in a solvent-free reaction system comprising at least one compound providing end groups M, at least one compound providing D units, and at least one Brønsted acid.

Process for producing endcapped, liquid siloxanes from silicone wastes

The production of SiOC-bonded, linear polydimethylsiloxane-polyoxyalkylene block copolymers comprising repeating (AB) units by reaction of polyether diols with trifluoromethanesulfonic acid-acidified, equilibrated α,ω-diacetoxypolydimethylsiloxanes is described, wherein the reaction is undertaken by adding a solid, liquid or gaseous base, optionally using inert solvents.

SiOC-bonded, linear polydimethylsiloxane-polyoxyalkylene block copolymers

Process for producing SiOC-bonded, linear polydimethylsiloxane-polyoxyalkylene block copolymers comprising repeating (AB) units, comprising pretreating acidified, end-equilibrated α,ω-diacetoxypolydimethylsiloxanes with a base and reacting the α,ω-diacetoxypolydimethylsiloxanes resulting therefrom with polyether diols in the presence of a solid, liquid or gaseous base, optionally using inert solvents.

The invention describes (i) reaction systems for the production of siloxanes bearing acetoxy functions, comprising a) silanes and/or siloxanes bearing alkoxy groups and/or b) silanes and/or siloxanes bearing acetoxy groups, c) silanes and/or siloxanes bearing hydroxy groups, d) optionally simple siloxane cycles and/or DT cycles, e) a reaction medium, comprising acetic anhydride, perfluoroalkanesulfonic acid and preferably acetic acid, (ii) a process for producing linear or branched siloxanes bearing acetoxy functions and also the use of same for producing polyethersiloxanes.

Reactive siloxanes

Described is a process for producing SiOC-bonded polyether siloxanes branched in the siloxane portion from cyclic branched siloxanes of the D/T type, wherein said process comprises in a first step reacting the mixtures of cyclic branched siloxanes of the D/T type with acetic anhydride optionally in admixture with simple siloxane cycles under acid catalysis to afford acetoxy-bearing branched siloxanes, in a second step performing the equilibration of the acetoxy-modified branched siloxane with superacid, preferably with addition of acetic acid and in a third step reacting the superacid-treated acetoxysiloxane with polyetherols optionally in the presence of bases and optionally in the presence of an inert solvent.

Process for producing SiOC-bonded polyether siloxanes branched in the siloxane portion

Upcycling process for producing acidic, end-equilibrated siloxanes bearing acetoxy groups and having chain lengths of greater than 3 silicon atoms from end-of-life silicones by thermal digestion in an acidic reaction medium comprising acetic anhydride, acetic acid and at least one further Br&#xf8;nsted acid having a pKa of &#x3c;4, the digestion taking place in a reactor having a volume of at least 1 liter.

Upcycling process for processing silicone wastes

Described is a process for producing SiOC-bonded polyether siloxanes branched in the siloxane portion from cyclic branched siloxanes of the D/T type, wherein said process comprises in a first step reacting the mixtures of cyclic branched siloxanes of the D/T type with acetic anhydride optionally in admixture with simple siloxane cycles under acid catalysis to afford acetoxy-bearing branched siloxanes, in a second step performing the equilibration of the acetoxy-modified branched siloxane with trifluoromethanesulfonic acid, preferably with addition of acetic acid, and in a third step reacting the trifluoromethanesulfonic acid-treated acetoxysiloxane with polyetherols optionally in the presence of bases and optionally in the presence of an inert solvent.

Method for preparing SiOC-linked polyether siloxanes branched in the siloxane part

The method for the physical reutilization of sheet-like siliconized structures comprises treating the sheet-like siliconized structure in a liquid digestion system comprising acetic anhydride and/or an acetoxysiloxane, and at least one Br&#xf8;nsted acid, optionally solvent, preferably with addition of acetic acid, and removing the desiliconized sheet-like structure from the liquid phase.

Physical reutilization of siliconized sheets

SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers of formula (I) C&#x2014;B-(AB)&#x2014;C1 are produced by reaction of end-equilibrated &#x3b1;,&#x3c9;-diacetoxypolydimethylsiloxanes with a mixture including at least one polyether polyol, preferably a polyether diol, and at least one polyether monool or at least one monohydric alcohol.

Process for producing polyoxyalkylene polysiloxane block polymers

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

Reaction system for preparing acetoxy function-bearing siloxanes having chain lengths of more than 3 silicon atoms, comprising silanes and/or siloxanes bearing alkoxy groups, silanes and/or siloxanes bearing acetoxy groups, silanes and/or siloxanes bearing hydroxy groups and/or simple siloxane cycles and/or DT cycles, and also a reaction medium comprising acetic anhydride, Br&#xf8;nsted acid and acetic acid, wherein Br&#xf8;nsted acids having a pKa &#x2264;&#x2212;1.30 are used, and wherein the acetic acid is present in the reaction system in amounts of 0.4 to 15.0 percent by weight, based on the reaction system, wherein the molar ratio of Br&#xf8;nsted acid used to acetic acid is in a defined range, with the proviso that either the sole use of trifluoromethanesulfonic acid and also of trifluoromethanesulfonic acid and acetic acid is excluded, and/or that the Br&#xf8;nsted acid used at least in part has a pKa between &#x2212;1.3 and &#x3e;&#x2212;13.5.

Acetoxy systems

Equilibrated trifluoromethanesulfonic acid-acidified &#x3b1;,&#x3c9;-diacetoxypolydimethylsiloxanes, processes for the production thereof and SiOC-bonded, linear polydimethylsiloxane-polyoxyalkylene block copolymers of the structure type ABA and a process for the production thereof are described, wherein the production of SiOC-bonded, linear polydimethylsiloxane-polyoxyalkylene block copolymers of the structure type ABA is effected by reacting trifluoromethanesulfonic acid-acidified acetoxysiloxane with polyetherols optionally in the presence of buffer mixtures and optionally an additional condensation catalyst and optionally in the presence of an inert solvent.

Linear polydimethylsiloxane-polyoxyalkylene block copolymers of the structure type ABA

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Essen, Germany

Horst Dudzik