Basf Aktiengesellschaft

Badische Anilin- & Soda-fabrik Aktiengesellschaft

Hans G Keppler

Rolf Moeller

Erhard Stahnecker

Klaus Hahn

Bruno Sander

Uwe Guhr

Hans Hintz

Eckhard Bonitz

Werner Simmler

Hermann Wesslau

Bead-form expandable styrene polymers are obtained by suspension polymerization of styrene with addition of from 1 to 10% by weight of C.sub.3 - to C.sub.6 -hydrocarbons as blowing agents and, if desired, customary additives, where

Preparation of bead-form expandable styrene polymers

A process for the preparation of styrene homopolymers or copolymers by suspension polymerization of monomers which contain dissolved styrene polymers from a preceding suspension polymerization, in the presence of sparingly soluble metal phosphates as suspension stabilizers, wherein, before the polymerization is started, the monomer phase is dispersed in an aqueous phase, containing a dissolved mineral acid, preferably phosphoric acid, at from 10.degree. to 80.degree. C. for from 5 to 120 minutes, after which the sparingly soluble metal phosphate is formed in situ in the aqueous phase. The process is particularly suitable for the preparation of expandable styrene polymers, in which case a volatile blowing agent is added to the suspension before, during or after polymerization.

Preparation of styrene suspension polymers

Styrene polymers are prepared by suspension polymerization using, as suspension stabilizers, mixtures of

Manufacture of styrene suspension polymers

Process for the manufacture of styrene polymers optionally containing blowing agent by polymerization in aqueous suspension using as the suspension stabilizer a calcium phosphate which after its manufacture by precipitation has been heated in aqueous dispersion for at least 2 hours at from 70.degree. to 130.degree. C. The styrene polymers may be used for the manufacture of foams.

A process for the manufacture of fibrids by dissolving, in a solvent, macromolecular waste materials from the bead polymerization of styrenes, and introducing the solution into a precipitation medium under the action of shearing forces to form fibrids.

Utilization of constituents of effluent from the manufacture of styrene

A process for the manufacture of expandable styrene polymers by suspension polymerization of the monomers in the presence of blowing agents and suspension stabilizers, the latter having been manufactured by polymerization of vinyl monomers in the presence of vinylpyrrolidone polymers. The expandable styrene polymers can be further processed to give foams.

Manufacture of expandable styrene polymers

Mixtures of aqueous synthetic rubber dispersions of alkali-insoluble copolymers of minor amounts of ethylenically unsaturated monomers (a) which form water-soluble hompolymers and major amounts of ethylenically unsaturated monomers (b) which form water-insoluble homopolymers have large particle size and are less viscous and easier to process than aqueous dispersions of the same solids concentration having small particle size.

Growing community of inventors

Weinheim, Germany

Hans G Keppler