Abstract: Foams having high compressive strength are obtained by extrusion of a mixture of a styrene polymer and from 3 to 9% by weight of a blowing agent consisting of from 80 to 100% by weight of CO.sub.2 and from 0 to 20% by weight of one or more halohydrocarbons or hydrocarbons which are gaseous at room temperature, the mixture being extruded into a zone under from 0.1 to 2 bar gage pressure and the foam being allowed to stabilize under this pressure.

Abstract: Polyolefin foams which have a density of from 30 to 300 g/l, do not exhibit after-shrinkage and possess taut cells are prepared by letting down a polyolefin/blowing agent gel, the latter first being let down to 0.1-10 bar gage pressure and the foam being kept at this pressure until it has cooled to at least 20.degree. C. below the expansion temperature.

Abstract: Closed-celled foams of high compressive strength are obtained by extruding a mixture of a styrene polymer and from 8 to 16% by weight of a blowing agent mixture containing from 2 to 20% by weight of ethyl chloride, from 2 to 20% by weight of carbon dioxide, from 20 to 80% by weight of dichlorodifluoromethane and from 10 to 60% by weight of monochlorodifluoromethane.

Abstract: A fireproofing material based on alkali metal silicates and containing from 20 to 60 percent by weight of water, which additionally contains from 1 to 10 percent by weight of a borate or an aluminate, preferably sodium aluminate, to improve the aging resistance. The fireproofing material can be used to insulate apertures and passages in building structures against the passage of fire and smoke, and can also be used as a fireproof glass.

Abstract: A process for the manufacture of fire protection materials, in which an aqueous alkali metal silicate solution is dried to a water content of from 6 to 40% and the resulting powder is thermoplastically molded to form sheets, tapes or strips. These can be fitted into openings and passages of building units; in the event of a fire they eliminate water and form a stable, heat-insulating foam.

Abstract: A process for the manufacture of cross-linked foamable moldings from olefin polymers, wherein the olefin polymer is mixed with(a) a solid organic blowing agent which eliminates gases when heated,(b) an organic peroxide,(c) conventional additives and(d) an activating organic compound which lowers the decomposition temperature of the peroxide,And the mixture is molded thermoplastically and is crosslinked below the decomposition temperature of the blowing agent but above the decomposition temperature of the activated peroxide.The organic activator is preferably a transition metal salt of a long-chain fatty acid.The moldings may be used for the manufacture of foams, for example for insulating purposes.

Abstract: Tubeless automobile tires filled with foam, the foam used being closed-cell foamed particles of a partially crystalline olefin polymer of olefins of from 2 to 6 carbon atoms.

Abstract: Shaped articles are produced by heating and compressing particles of foamed olefin polymer containing crosslinked portions in molds, the pressure being reduced during compression in the mold.

Abstract: Treatment of waste water produced in the manufacture of expandable polystyrene, comprising passing a stream of fine gas bubbles through the waste water and removing the resulting foam containing a high concentration of impurities from the aqueous phase. In a special embodiment of the invention, the aqueous phase can then be subjected to further treatment.

Abstract: Foam moldings of olefin polymers are prepared by heating, and pressing together, foamed particles of an olefin polymer, containing crosslinked constituents, in molds, a temperature gradient of from 0.5.degree. to 25.degree. C per cm of loose mass of particles being established in the mold, which has a gas-permeable wall on the lower-temperature side.

Abstract: Particulate expandable styrene polymers requiring short residence times in the mold are obtained by polymerizing styrene and, optionally, other copolymerizable monomers in the presence of expanding agents and from 0.001 to 0.1% by weight of a brominated oligomer or polymer of a 1,3-diene for at least part of the time at temperatures of from 110.degree. to 140.degree.C.