Wacker Chemie Ag

Gerhard Staiger

Michael Geck

Wolfgang Schattenmann

Georg Loessel

Manfred Meisenberger

Klaus Kaeppler

Paul Fuchs

Peter Jerschow

Norbert Ellinger

Oliver Fuhrmann

Klaus Käppler

Georg Lößel

A targeted molecular weight of an organopolysiloxane is obtained in a two stage hydrolysis by hydrolyzing a chlorosilane with from 0.002 to 0.6 mol of water in a first step in the presence of alcohol, in which the pressure and/or temperature are adjusted such that following further hydrolysis in a second step, the targeted molecular weight is obtained.

Process for preparing organopolysiloxanes

Organopolysiloxanes with consistent product properties are prepared while minimizing alcohol usage in the hydrolysis of chlorosilanes by use of a vertical continuous loop reactor having a heating unit on an ascending side of the loop which is regulated such that the temperature of the reactant mixture is within &#xb1;5&#xb0; C. of a set value.

Method for producing organopolysiloxanes

Mixtures containing high boiling and low boiling components, at least one component being dissociatable into ions, are separated effectively by heating by passing an alternating electrical current through the mixture. The process is particularly effective in the workup of crude alkylchlorosilanes from the direct synthesis.

Method for evaporating components of a liquid

One-component, H-siloxane-containing addition-crosslinkable silicone resins, are prepared by charging a reactor with water and a solvent mixture of at least one aromatic solvent and at least one alkyl ester, adding a chlorosilane mixture containing an Si&#x2014;H functional silane and a silane bearing an unsaturated hydrosilylatable group with stirring, the temperature not being above 50&#xb0; C., separating an aqueous phase comprising a one-component, H-siloxane-containing addition-crosslinkable silicone resin, and washing the phase comprising the one-component, H-siloxane-containing addition-crosslinkable silicone resin in at least two washing steps to reduce residual HCl content, a final washing carried out using a 0.01%-1.0% strength aqueous solution of a base with a pH between 7.00-8.50, at a temperature of 20-50&#xb0; C.

Silicone resin coating for electronic components

The invention relates to a pelletized organopolysiloxane material, to a process for producing the pelletized material, and to the use of the pelletized organopolysiloxane material as an additive for thermoplastics.

Pelletized organopolysiloxane material

Addition-crosslinking silicone resin compositions containing selected high functionality addition curable organosilicon compounds can be cured at relatively low temperatures and can produce highly transparent, hard polymers which are suitable for many uses, in particular for the potting or embedding of electrical componts such as LEDs.

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Kirchdorf, Germany

Gerhard Staiger