Wacker-chemie Gmbh

Johann Bauer

Klaus Adler

Engelbert Pichler

Thomas Balwe

Alex Sabel

Gerhard Beier

Friedrich Heichele

Helmut E Thyret

Gunter Kratel

Dieter Kurz

Rudolf Wiedholz

Heinz Hefner

Hans-Peter Kalmuk

Herbert Kandler

Josef Hanzalik

Georg Hollenbach

Erich Manner

Wilfried Dressler

Helmut Wimmer

Hansjochen Barth

Joseph Heckmaier

Johann Birke

Kai Rostock

Hans Sommer

Kurt Fendel

Hans Birke

Harald Sulek

Georg Vojtechovsky

Christoph Kemenater

Herbert Furst

An improvement in the process of producing polyvinyl chloride by the suspension process in the presence of protective colloids by utilizing a protective colloid mixture of from 20% to 80% of the protective colloid mixture of a polyvinyl acetate having a hydrolysis degree of 40 to 55 mol % and the remainder of the protective colloid mixture of (1) a water-soluble polyvinyl alcohol having a hydrolysis degree of 70 to 90 mol %, or (2) an aminoethyl-hydroxypropyl cellulose having a molar substitution of from 0.05 to 1.5 mols of aminoethyl groups and 3 to 5 mols of hydroxypropyl groups, or (3) a vinyl acetate/vinyl pyrrolidone copolymer having a ratio of vinyl pyrrolidone to vinyl acetate in the copolymer of 50% to 70% by weight to 30% to 50% by weight and a K-value of 25 to 40. By the use of this protective colloid mixture, the polyvinyl chloride produced exhibits a large absorption of plasticizer and gives finished products having a low number of specks.

Process for suspension polymerization of vinyl chloride employing mixed

A polymerization autoclave for the suspension polymerization of vinyl compounds in the aqueous phase having a volume of from 50 to 200 m.sup.3, an impeller agitator driven from below at the bottom of the autoclave and two cylindrical displacement bodies acting as flow interrupters, secured downwardly from the autoclave dome, where the autoclave has a height-to-diameter ratio of from 2.4 to 3 with a critically dimensioned agitator and critically dimensioned flow interrupter fittings. By the use of this invention in the case large-scale autoclaves, the heat of polymerization can be removed merely by wall-cooling. The autoclave according to the invention are very economical, as shown by, for example, a spatial capacity of 0.3 to 0.4 metric tons of polyvinyl chloride per m.sup.3 autoclave volume.

Polymerization autoclave

In the process for steam-stripping residual monomer from an aqueous polymer dispersion comprising injecting steam into an aqueous polymer dispersion containing residual monomers and the customary amounts of emulsifiers and/or protective colloids, said dispersion having a solids content of from 15% to 55% by weight with simultaneous evacuation of the gas space above the dispersion whereby said gas space is maintained at a subatmospheric pressure and said residual monomers are volatilized, the improvement consisting of injecting a sufficient volume of steam into said aqueous polymer dispersion whereby from 5% to 50% by weight of the injected steam passes through said dispersion uncondensed, thereby substantially preventing formation of foam above said dispersion.

Process for prevention of foaming when steam-stripping residual monomer

A process for the manufacture of vinyl chloride copolymers soluble in lacquer solvents with a clear solution consisting of copolymerizing vinyl chloride and at least one other olefinically-unsaturated compound copolymerizable with vinyl chloride under suspension copolymerization conditions in an aqueous dispersion and in the presence of (a) a monomer-soluble polymerization catalyst, (b) a water-soluble salt of a maleic acid anhydride mixed polymerizate of maleic acid anhydride, an olefinically unsaturated ester or ether of at least 7 carbon atoms, and another vinyl monomer, (c) from 0.003% to 0.007% by weight of a polyvinyl alcohol having a low viscosity and a high saponification number and (d) from 0.03% to 0.05% by weight of sodium chloride, whereby a vinyl chloride copolymer is obtained having the majority of its particles of a size between 0.1 and 0.5 mm.

Process for the manufacture of vinyl chloride copolymers of a small and

An improvement in the suspension polymerization of a polymerizate containing at least 90% polyvinyl chloride by the steps of mixing monomers selected from the group consisting of vinyl chloride and mixtures of vinyl chloride with up to 10% of olefinically unsaturated compounds copolymerizable with vinyl chloride, with water in the presence of a polymerization catalyst and suspension stabilizers, heating said mixture under continuous agitation to polymerization temperatures and recovering said polymerizate. The improvement comprises utilizing a gas containing molecular oxygen as the sole catalyst or catalyst-forming substance. The so-prepared polymerizate forms sheets with a lower content of 'fish eyes' and a greater heat stability.

Process for suspension polymerization of vinyl chloride with molecular

A method of reducing the electrostatic charge aquired by a plastic composition by incorporating therein an antistatically effective amount of a mixed oxide of phosphorus and one or more metals selected from the group consisting of silicon, aluminum, titanium and iron, said mixed oxide having been prepared by flame hydrolysis; as well as the plastic composition containing said mixed oxide.

Method of reducing static electricity in plastic compositions and

An adhesion assistant or binder composition for bonding polyolefin surfaces with metal surfaces comprising an aqueous dispersion of an ethylene/vinyl acetate copolymer from 0.5 to 5 parts by weight based on 100 parts of the copolymer of a cross-linking peroxide compound and from 1 to 10 parts by weight based on 100 parts of the copolymer of a low-molecular-weight 1,2-polybutadiene; as well as a process for producing composite bodies by heat and pressure utilizing the above adhesion assistant between polyolefin surfaces and metal surfaces.

Adhesive composition and method for bonding polyolefin surfaces with

A readily dryable adhesive binder for particulated rubber and/or plastics compositions comprising from 1% to 10% by weight of a water-solubleformaldehyde polycondensation resin, from 0.5% to 5% by weight of formaldehyde or a compound liberating formaldehyde, and from 85% to 98.5% by weight of a film-forming plastics dispersion; as well as a composition forming a resilient covering comprising from 40% to 75% by weight of particulated rubber and/or plastics and from 25% to 60% by weight of the above adhesive binder.

Particulated rubber and plastics coverings and binders therefor

A process for the production of polyvinyl chloride graft copolymers from ethylene/vinyl acetate copolymers and vinyl chloride by graft polymerization in the aqueous phase consisting essentially of adding a water-soluble, free-radical-forming polymerization catalyst to an aqueous dispersion of an ethylene/vinyl acetate copolymer optionally containing additional emulsifiers and/or dispersion stabilizers, heating said dispersion to the polymerization temperature, adding vinyl chloride gas above said agitated heated dispersion at such rate that the pressure is below the saturation pressure of vinyl chloride at the polymerization temperature, and recovering said polyvinyl chloride grafted copolymer.

Process for the production of polyvinyl chloride graft copolymers

An impact resistant thermoplastic molding composition comprising

Impact resistant thermoplastic PVC molding composition

Impact-resistant molding compositions consisting essentially of

Impact-resistant molding compositions containing polyvinyl chloride

An apparatus for the production of extruded profiles of foamed thermoplasts consisting of an extruder having an extrusion screw or helix and a form-giving extruder head having a flow channel there-through, at least part of the length of said flow channel being divided by separating walls having a thickness of 0.2 to 3 mm arranged in the axial direction into individual channels of such a length and cross-section area whereby each individual channel has a nozzle coefficient k of from 0.1 to 2mm.sup.3, characterized in that thorn-like pins are inserted into some of the individual channels; as well as the process of extrusion.

Apparatus for the preparation of foamed thermoplastic extruded profiles

Vinyl chloride terpolymers soluble in aromatic compounds with a K-value of from 25 to 38, measured in cyclohexanone consisting of an emulsion polymerized monomer mixture of from

Growing community of inventors

Burghausen, Germany

Johann Bauer