Chemische Werke Huls Aktiengesellschaft

Chemische Werhe Huls Ag

Horst Leithauser

Josef K Rigler

Karl Trukenbrod

Ekkehard Wienhofer

Hans-Josef Ratajczak

Heinz Osterhoff

Dirk Reese

Wolfgang Schafer

Werner Bollmann

Josef-Karl Rigler

Werner Ogrzewalla

A process for controlling bead size in the production of expandable styrene polymers by suspension polymerization is carried out by adding protective colloids to the aqueous phase before polymerization begins, such protective colloids being used which are homogeneously soluble in water over the entire temperature range from 25.degree. to 125.degree. C. and in which the concentration range being employed shall not lower the boundary surface tension water/styrene below 18 N/mm.sup.2. Lastly, the protective colloids are selected according to their molecular weight and the weight ratio of aqueous to organic phase lies in the range of 0.9:1 to 1:1.25, preferably in the range of 1:1. A grain spectrum is maintained predominantly greater than 0.41 to less than 2.5 mm by varying the molecular weights of the protective colloids.

Method for controlling bead size in the production of expandable styrene

A process for controlling bead size in the manufacture of expandable styrene polymers by suspension polymerization, wherein, referred to the aqueous phase, a concentration of ions of calcium, aluminum, metals of the 1st, 2nd, or 6th through 8th side groups of the period table of elements of 3.times.10.sup.31 5 to 3.times.10.sup.-2 % by mass is established, these metal ions being present as cations in the higher oxidation stage of water-soluble, inorganic salts.

Process for controlling bead size in the manufacture of expandable

A process for preparing improved molding materials of expandable styrene polymers by coating the particles with glycerin esters of long-chain fatty acids. The coating comprises organosols of pulverulent glycerin esters having 14 to 24 carbon atoms in aliphatic hydrocarbons having 3 to 8 carbon atoms. The proportion of glycerin monoester is at most 40, but not less than 10% by weight and the particle size of the pulverulent ester is less than 100 microns. The molding materials are used to manufacture molded articles.

Method for preparing improved molding materials from coated fine

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

Horst Leithauser