Dow Corning Toray Silicone Company Limited

Dow Corning S.a.

Takao Takemasa

Tadashi Okawa

Mitsuo Hamada

Patrick Leempoel

Junichi Maeshima

Eric Damme

Fabrice Lebecq

Norikatsu Higuchi

Masaru Kobayashi

Jean-Marc Gilson

Naoya Matsui

Toshio Okuyama

Process for the production of cyclic siloxane

A continuous method for performing a hydrosilylation reaction comprising effecting a hydrosilylation reaction between a liquid organosilicon compound (A) having in each molecule at least one silicon-bonded hydrogen atom and a liquid organosilicon compound (B) having in each molecule at least one aliphatic unsaturated bond in the presence of a platinum catalyst (C) continuously in a tubular reactor equipped with a stirring and plug-flow maintaining apparatus located within the reactor.

Continuous hydrosilylation method for production of a modified liquid organosilicon compound

This specification describes and claims a process for preparing chain-extended organopolysiloxanes. The process comprises the steps of: A) mixing organopolysiloxanes having at least one silicon-bonded hydroxyl group per molecule with a polymerization catalyst to form a mixture, B) allowing the mixture of step A to react so as to produce a reaction product comprising polymerized organopolysiloxanes of which some have at least one silicon-bonded hydroxyl group per molecule and C) allowing the silicon-bonded hydroxyl group containing organopolysiloxanes of the reaction product of step B to react with a nitrogen-containing silylating agent capable of chain-extending to produce a chain-extended organopolysiloxane. Preferably the silylating agent is a cyclosilazane. Organopolysiloxanes having terminal groups other than silicon-containing hydroxyl groups and which are capable of equilibrating with the mixture of step A and/or the reaction product of step B may also be introduced prior to step C. The chain-extended organopolysiloxanes are suitable for use in sealant compositions.

Process for preparing chain-extended organopolysiloxanes

A method of improving the efficient depletion of the siloxane oligomer present in organopolysiloxane moldings by using supercritical carbon dioxide gas, so that this reduction in siloxane oligomer content is accomplished without cracking of the moldings by regulating the pressure reduction to less than 40 Kg/cm.sup.2 per 1 hour during the release to atmospheric pressure.

Method for reducing the quantity of siloxane oligomer in

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Chiba, Japan

Takao Takemasa