Wacker Chemie Ag

Wacker-chemie Gmbh

Thomas Köhler

Hans-Peter Weitzel

Richard Weidner

Theo Mayer

Oliver Schäfer

Reinhard Härzschel

Christoph Briehn

Jochen Ebenhoch

Bernd Schilling

Martina Belitzer

Yolker Staniek

Oliver Windt

Hans Wintrich

Rene Grawe

René GRÄWE

A method for producing polyvinyl alcohols by means of catalytic reactions of alcoholic polyvinyl ester solutions in extruders, wherein the polyvinyl esters are based exclusively on ethylenically unsaturated monomers and wherein one or more neutralizing agents are added to the product of the catalytic reaction.

Method for producing polyvinyl alcohol

The invention relates to cross-linkable vinylester-copolymers obtained by means of radically initiated polymerisation of a) one or more vinyl esters and b) one or more ethylenically unsaturated, epoxy functional monomers, and by a subsequent reaction that is analogous to polymerisation of the thus obtained base polymers with one or more ethylenically unsaturated acids g), such that at least one ethylenically unsaturated, polymerizable group is introduced into each base polymer. Said invention is characterised in that the cross-linkable vinylester-copolymers have molecular weights of Mn of &#x2267;6.500 g/mol.

Crosslinkable vinyl ester copolymers and their use as low-profile additives

The invention relates to a method for producing solutions of vinyl polymers in reactive monomers by a) polymerizing by radical initiation one or more ethylene unsaturated monomers selected from the group comprising vinyl esters, acrylic acid esters, and methacrylic acid esters, and optionally one or more further ethylene unsaturated monomers, and subsequently b) optionally distilling off volatile components, and c) optionally adding one or more inert solvents, d) mixing with one or more reactive monomers, and e) optionally distilling off the inert solvent, characterized in that the vinyl polymers are not present as isolated solids in any of the steps a) through e).

Production of solutions of vinyl polymers in reactive monomers

Particles of metal and non-metal oxides may be readily functionalized with organosilyl groups, even in the absence of catalysts, when methylene-spaced alkoxysilanes are used for functionalizing. When an excess of alkoxy groups relative to metal-OH groups are present, the resulting functionalized particles exhibit high reactivity, particularly upon exposure to moisture. Functionalization is particularly useful with particles of organopolysiloxane resins.

Organosilyl functionalized particles and the production thereof

The invention relates to a method for isolating polyorganosiloxanes from an aqueous dispersion, wherein the polyorganosiloxanes are separated from water in a dissolved form with the aid of an extraction agent.

Method for isolating polyorganosiloxanes

The invention provides mixed aromatic vinyl-1,3-diene polymers stabilized by a protective colloid and present in the form of aqueous polymer dispersions or polymer powders redispersible in water as adhesives for porous substrates. The polymer dispersions and the polymer powders are obtained by emulsion polymerization of a mixture containing: a) 20 to 80 percent by weight of one or more vinylaromatics; b) 19.9 to 79.9 percent by weight of one or more 1,3-dienes; c) 0.1 to 15 percent by weight of one or more comonomers from the group consisting of N-methylolacrylamide, N-methylolmethacrylamide and the N-(alkoxymethyl)-acrylamides and N-(alkoxymethyl)-methacrylamides with a C to C -alkyl radical. The sum of the above percentages adds up to 100% by weight. Emulsion polymerization is carried out in the presence of one or more protective colloids and without emulsifiers, optionally followed by drying of the resulting aqueous polymer dispersion.

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Kastl, Germany

Thomas Köhler