Chemische Werke Huls Aktiengesellschaft

Mitsubishi Petrochemical Company Limited

Huls Aktiengesellschaft

Chemische Werhe Huls Ag

Karl Trukenbrod

Josef K Rigler

Horst Leithauser

Ekkehard Wienhofer

Hans-Josef Ratajczak

Hideyuki Takahashi

Franz-Michael Bollenrath

Tomohiko Takahama

Tadamichi Aoki

Wolfgang Schafer

Yoshikazu Higaki

Shohei Suzuki

Werner Bollmann

Heinz Osterhoff

Werner Ogrzewalla

A method of inhibiting polymerization of styrenes is disclosed, comprising the process of jointly using nitrosophenols and p-tertiarybutyl catecol for composing the polymerization inhibiting agent usable during the distillation process of styrenes.

Method of inhibiting polymerization of styrenes

Process for the production of fine particulate, expandable styrene polymers by suspension-polymerizing styrene or possibly mixtures of styrene and other monomers having at least 50% by weight of styrene in the presence of expanding agents having low boiling points in incompletely filled reactors. The polymer beads to be charged with expanding agents are vigorously stirred during the addition of the expanding agent(s) in such a manner that these beads undergo the least possible contact in time and space with the gas phase and with each other, and so that the surface of the stirred medium retains a topology as free as possible from a funnel shape during stirring.

Production of fine particulate, expandable styrene polymers with

Fine particulate expandable flame retardant styrene polymers having an improved minimum mold dwell time and reduced block shrinkage are prepared by:

Fire retardant fine particulate expandable styrene polymers

Fire retardant, expanded styrene polymer shaped objects are prepared by: (a) mixing styrene monomer or a mixture thereof with at least one comonomer, an expanding agent and a fire retardant, organic halogen compound in a aqueous dispersion; (b) adding to (a) either before or during polymerization from about 0.0001 to 0.1 percent by weight esters soluble in the organic phase of (a), these esters of aliphatic dicarboxylic acids and aliphatic epoxy alcohols having at least 11 carbon atoms; (c) polymerizing the aqueous dispersion of (a) and (b) using radical forming initiators at a temperature of about 80.degree. to 130.degree. C.; (d) separating bead polymers having diameters between about 0.4 and 3 mm; (e) pre-foaming the beads; (f) ageing the pre-foamed beads; and (g) final forming the aged and pre-foamed beads in a pressure resistant mold.

Fire retardant particulate expandable styrene polymers

Fire retardant, expanded styrene polymer shaped objects are perpared by:

Self-extinguishing, fine particulate, expandable styrene polymers for the manufacture of molded articles, containing bromine compounds and one synergist. The synergist, referred to the styrene polymer, is at least one hydrocarbon present in amounts from about 0.1 to 3% by weight and forms stable radicals at temperatures above 300.degree. C.

Self-extinguishing, fine particulate expandable styrene polymers

Self-extinguishing fine particulate expandable styrene polymers

Fine particulate expandable styrene polymers have coatings applied thereto by:

Method for coating fine particulate expandable styrene polymers

Small particulate expandable styrene polymer molding compositions are prevented from acquiring static charges by coating with betaines.

Small particulate expandable styrene polymer molding compositions

The process for the preparation of shaped bodies based on expanded styrene polymers comprising: the polymerization of styrene or a mixture thereof with at least one monomer copolymerizable therewith, the addition of an expanding agent, pre-forming of the resulting expandable particles, ageing of the pre-formed particles, and molding thereof in a pressure resistant mold, is improved in the decrease of the minimum mold dwell time by carrying the polymerization in the presence of 0.0005 to less than 0.01% by weight based on the styrene polymer of organic bromine compounds which give a chain transfer constant of at least 200 and at 100.degree. C. in bidistilled water the bromine compounds split off less than one molar % of hydrogen bromide per equivalent of bromine present in the molecule.

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Marl, Germany

Karl Trukenbrod