Wacker Chemie Ag

Consortium Fur Elektrochemische Industrie Gmbh

Alfred Popp

Volker Stanjek

Torsten Gottschalk-Gaudig

Elke Fritz-Langhals

Jürgen Stohrer

Hermann Petersen

Klaus Kaeppler

Thomas Kornek

Oliver Schäfer

Jürgen Pfeiffer

Ulrike Buettner

Jodoca Rockinger-Mechlem

Andrea Gilch

Klaus Käppler

Christine Kaes

Margit Steiner-Langlechner

Ulrike BÜTTNER

The object of the invention is therefore to provide a method for the preparation of amino-functional polyorganosiloxanes, in which (A) organosiloxanes containing Si&#x2014;OH groups are reacted with (B) at least stoichiometric amounts of monoalkoxy(aminoalkyl) silanes with respect to the Si&#x2014;OH groups, wherein catalytically active additives selected from acid, base or metal-organic compound are used in amounts of less than 0.1 ppm acid, less than 30 ppm base and less than 0.4% metal-organic compound.

Method for producing organosilicon compounds having amino groups

Organopolysiloxanes containing units of the formulae ORSi&#x2014;Y&#x2014;(SiRO)and RSiOare prepared by catalyzed reaction, in a first step, of a mixture of XRSi&#x2014;Y&#x2014;(SiRX)and RSiXand siloxanes which have structural units of the formulae ORSi&#x2014;Y&#x2014;(SiRO)and RSiOand having weight average molar mass of 100 to 950 g/mol and reacting the mixture obtained therefrom with water or aqueous acid, producing organopolysiloxanes having a weight average molar mass of 1,000 to 100,000 g/mol, wherein R and Reach are monovalent CSiC-bonded organic groups optionally containing one or more N and/or O atoms, Y is a 2-12 valent Corganic group optionally containing one or more O atoms, X is a hydrolyzable group, a is 0 or 1, b is 1 to 11, and c is 0, 1, 2, or 3.

Method for producing organopolysiloxanes

Cyclic siloxanes are separated from short chain hydroxyl-terminated siloxanes by contact with steam at at least 650 hPa absolute. The cyclic siloxanes and other components which are separated by use of steam can be recovered by phase separation, and preferably used in other processes.

Separating cyclic siloxanes from short-chain siloxanes having terminal hydroxyl groups

Blocked silyl isocyanates contain a methylene group between the blocked isocyanate group and silicon. The blocked isocyanates are easily prepared in high yield and purity.

Organosilicon compounds with a masked isocyanate group

A process is provided for preparing an enantiopure 1,3-dioxolan-4-one or 1,3-oxathiolan-5-one derivative, which includes bringing a mixture containing enantiomeric 1,3-dioxolan-4-one or 1,3-oxathiolan-5-one derivatives and an enzyme with hydrolytic activity into contact in the presence of a nucleophile. Cleaving a dioxolanone/oxathiolanone ring of one enantiomer occurs by the enzyme with hydrolytic activity and, after the cleavage of one enantiomer has taken place, the uncleaved enantiomer of the 1,3-dioxolan-4-one or 1,3-oxathiolan-5-one derivative is isolated.

Process for the enzymatic preparation of enantiopure 1, 3-dioxolan-4-one and 1,3-oxathiolan-5-one derivatives

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Unterhaching, Germany

Alfred Popp