Dow Corning S.a.

Dow Corning Corporation

Jean-Marc Gilson

Denis Sbardella

Didier P Vanderveken

Jean De La Croi Habimana

Viken Kortian

Emulsions containing liquid polymers are made by first condensing monomers in a polymerization reactor having an inlet, a reaction chamber, and an outlet. The monomers are mixed with a condensation catalyst, and a pressurized gas forms a foaming mixture. The foaming mixture is fed down the chamber to the outlet while the monomers polymerize in the chamber. Water and a surfactant are then fed to the lower end of the chamber to form a water-in-oil emulsion with the aid of the foaming action in the chamber. A shear device then inverts the water-in-oil emulsion to an oil-in-water emulsion.

Method of making polysiloxane emulsions

A continuous static polymerization reactor for the production of liquid polymers comprises an elongated hollow reaction chamber (30) which has a porous wall (31) and a jacket means (40) spaced around the reaction chamber (30), which is provided with means (44) for introducing a fluid through the porous wall (31). The reactor is particularly useful for a process for making liquid polymers by condensing monomers and/or oligomers. It comprising the use of a pressurized gas to cause the reaction mixture to reach a foam consistency. This is beneficial in the condensation polymerization. Feeding a fluid through the porous wall into the reaction chamber avoids build up of the polymer on the wall.

Polymerization reactor and polymerization process

A continuous static polymerization reactor for the production of liquid polymers comprises an elongated hollow reaction chamber (30) which has a porous wall (31) and a jacket means (40) spaced around the reaction chamber (30), which is provided with means (44) for introducing a fluid through the porous wall (31). The reactor is particularly useful for a process for making liquid polymers by condensing monomers and/or oligomers. It comprising the use of a pressurized gas to cause the reaction mixture to reach a foam-like consistency. This is beneficial in the condensation polymerization. Feeding a fluid through the porous wall into the reaction chamber avoids build up of the polymer on the wall.

A method of making organopolysiloxanes comprises contacting organosilicon compounds having at least one unit ##EQU1## wherein R.degree. is hydrogen, hydroxyl, a C.sub.1-18 hydrocarbon, substituted hydrocarbon or hydrocarbonoxy group and a has a value of from 0 to 4 with a phosphonitrile halide AB, wherein A is a phosphonitrile halide cation [X(PX.sub.2 .dbd.N).sub.n PX.sub.3 ].sup.+, wherein X is halide and n is from 1 to 8 and B is an anion derived from a Lewis acid not containing a P atom, e.g. [MX.sub.(v-t+1) R.sup.2 .sub.t ].sup.-. The method is particularly useful for condensation of silanol end-blocked siloxanes.

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Sombreffe, Belgium

Jean-Marc Gilson