Abstract: The invention relates to a process for producing foam webs by foam extrusion of a mixture of a polysulfone or polyether sulfone and a volatile blowing agent, where the blowing agent is water or a mixture of water with an inert gas or organic liquid, e.g. an alcohol or a ketone.

Abstract: The present invention relates to an open-cell foam, and to a process for producing this open-cell foam by melting a thermoplastic, or a mixture comprising a thermo-plastic, giving a melt, mixing the melt with at least one blowing agent under pressure, and foaming the melt comprising the blowing agent via extrusion into the free atmosphere, the temperature of the melt during the foaming process being greater than the melt temperature at which a closed-cell foam is formed, and/or adding a pulverulent solid, and/or adding a foreign polymer. The present invention further relates to the use of the foam of the invention for sound deadening or for producing materials by sound deadening.

Abstract: In a process for preparing polyisocyanate polyaddition products by reacting isocyanates with compounds which are reactive toward isocyanates, in the presence or absence of blowing agents, catalysts, auxiliaries and/or additives, the reaction is carried out in the presence of (i) particles which have a size of <200 &mgr;m and a melting point in a range from 50 to 300° C., or in the presence of thermoset particles (ii) or in the presence of particles (i) and (ii).

Abstract: In a process for producing polyurethane foams by reacting isocyanates with compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, the isocyanates used are (cyclo)aliphatic isocyanates and the reaction is carried out in the presence of substances which effect framework formation in the polyurethane foam.

Abstract: In a process for preparing polyisocyanate polyaddition products by reacting isocyanates with compounds which are reactive toward isocyanates, in the presence or absence of blowing agents, catalysts, auxiliaries and/or additives, the reaction is carried out in the presence of (i) particles which have a size of <200 &mgr;m and a melting point in a range from 50 to 300° C., or in the presence of thermoset particles (ii) or in the presence of particles (i) and (ii).

Abstract: Mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (raw MDI) having a reduced iodine color number and a reduced chlorine content are prepared by reacting the corresponding mixtures of diphenylmethanediamines and polyphenylpolymethylenepolyamines with phosgene in the presence of at least one inert organic solvent at elevated temperature, and then, after phosgenation is complete, incorporating into the reaction mixture, in the presence or absence of the phosgene, a mixture of water and at least one monohydric or polyhydric polyoxyalkylene alcohol, preferably having a functionality of from 2 to 3, and advantageously having a hydroxyl number of from 20 to 1800, in an effective amount which advantageously comprises from more than 0.01 to 0.3% by weight of water (i) and from 0.

Abstract: A process for the preparation of foamed plastics materials based on polyisocyanate polyaddition products by the reaction of isocyanates with isocyanate-reactive compounds in the presence of catalysts and, optionally, auxiliaries and/or additives, wherein i) isocyanates having isocyanurate and/or biuret structures are used, the isocyanate-reactive compounds used are ii) at least one diol and/or polyol having a molecular weight of from 400 to 8000 and containing at least 50% of primary hydroxyl groups based on all of the hydroxyl groups present in the compound, iii) at least one compound having at least one primary amine group, and diols and/or triols having molecular weights of less than 400 are optionally used as chain-extending and/or crosslinking agents, the reaction being carried out in the presence of iv) at least one tertiary amine acting as catalyst and/or v) at least one metal salt acting as catalyst and vi) water.

Abstract: Two-component polyurethane systems composed of an at least bifunctional polyisocyanate component and a polyol component have a polyol component which comprises at least one hydroxyl-containing cyclic acetal and/or ketal.

Abstract: In a process for producing self-releasing, compact or cellular moldings which comprise polyisocyanate polyaddition products and may contain reinforcing material by reacting a) organic and/or modified organic polyisocyanates with b) at least one compound containing at least two reactive hydrogen atoms and having a molecular weight of from 62 to 10,000 and, if desired, c) chain extenders and/or crosslinkers in the presence of d) internal mold release agents and in the presence of or absence of e) catalysts, f) blowing agents, g) reinforcing materials and h) auxiliaries in an open or closed mold, the internal mold release agents (d) used are diesters and/or monoesters of alkylsuccinic acids and/or diesters and/or monoesters of alkenylsuccinic acids.

Abstract: In a process for producing foams based on polyisocyanate polyaddition products by reacting isocyanates with compounds which are reactive toward isocyanates and have a molecular weight of from 400 to 8000 in the presence of blowing agents, catalysts and, if desired, chain extenders and/or crosslinkers having a molecular weight of <400, auxiliaries and/or additives, use is made of isocyanates having isocyanurate and/or biuret structures, at least one compound which is reactive toward isocyanates, has a molecular weight of from 400 to 8000 and contains at least 50% primary hydroxyl groups, as catalysts at least one tertiary amine and at least one metal salt plus from 0.5 to 5.3% by weight of water, based on the weight of the compounds which are reactive toward isocyanates and have a molecular weight of from 400 to 8000, and the reaction is carried out at >40.degree. C.

Abstract: Sheet-like polyurethane moldings are produced by impregnation of porous sheets with a prepolymer containing free isocyanate groups and reversibly blocked isocyanate-reactive groups or containing free isocyanate-reactive groups and reversibly blocked isocyanate groups, and subsequent reaction of the prepolymers in a heated mold.

Abstract: In a process for producing sheet-like polyurethane moldings by impregnation of porous sheets with a polyurethane system and subsequent reaction of the polyurethane system in a mold, the porous sheet is first fully impregnated with a polyurethane component, then fully impregnated with the other polyurethane component and the molding is then produced in a heated mold by reaction of the polyurethane components.

Abstract: The present invention relates to expandable styrene polymers containing recycled polystyrene, having a recycled material content of from 10 to 50% by weight, based on the total weight of the polystyrene, to which alkyldi(2-hydroxyethyl)amines have been added during the polymerization.

Abstract: A process for the preparation of bead-form expandable styrene polymers by polymerizing styrene, if desired in the presence of further comonomers, in aqueous suspension in the presence of organic molecular colloids as suspension stabilizers and conventional styrene-soluble polymerization catalysts and with addition of a blowing agent and, if desired, conventional additives in effective amounts, wherein the aqueous suspension contains at least one olefinically unsaturated carboxylic acid or a water-soluble salt thereof in an amount, based on the organic phase, of from 0.002 to 0.3% by weight of carboxylate anions.

Abstract: The invention relates to a process for the preparation of CFC-free, flexible polyurethane foams or molded foams by reactingA) liquid polyisocyanate mixtures containing bonded urethane groups and having a content of NCO groups of from 20 to 30% by weight, these mixtures themselves being prepared by reacting a mixture of diphenylmethane diisocyanates and polyphenyl-polymethylene polyisocyanates (crude diphenylmethane diisocyanate) with a polyether-polyol mixture, having a hydroxyl number of from 120 to 25, of at least one polyoxypropylene glycol and at least one trifunctional polyoxypropylene-polyoxyethylene glycol having a content of ethylene oxide units of from 90 to 10% by weight or by reacting 4,4'-diphenylmethane diisocyanate (diphenylmethyl diisocyanate) or an diphenylmethane diisocyanate isomer mixture with said polyether-polyol mixture to give an NCO-containing quasi-prepolymer and diluting this quasi-prepolymer with crude diphenylmethane diisocyanate, withB) relatively high-molecular-weight polyhydroxy

Abstract: The invention relates to a process for the preparation of CFC-free, flexible polyurethane foams or molded foams by reactingA) liquid polyisocyanate mixtures containing bonded urethane groups and having a content of NCO groups of from 20 to 30% by weight, these mixtures themselves being prepared by reacting a mixture of diphenylmethane diisocyanates and polyphenyl-polymethylene polyisocyanates (crude diphenylmethane diisocyanate) with a polyether-polyol mixture, having a hydroxyl number of from 120 to 25, of at least one polyoxypropylene glycol and at least one trifunctional polyoxypropylene-polyoxyethylene glycol having a content of ethylene oxide units of from 90 to 10% by weight or by reacting 4,4'-diphenylmethane diisocyanate (diphenylmethyl diisocyanate) or an diphenylmethane diisocyanate isomer mixture with said polyether-polyol mixture to give an NCO-containing quasi-prepolymer and diluting this quasi-prepolymer with crude diphenylmethane diisocyanate, withB) relatively high-molecular-weight polyhydroxy

Abstract: Expandable styrene polymers containing recycled polystyrene have a content of recycled material of up to 40% by weight, based on the total weight of the polystyrene, wherein, in the course of the polymerization of the reaction mixture, from 100 to 500 ppm of a molecular weight regulator and/or from 0.05 to 1.0% by weight, based in each case on the polymerization solution, of a finely divided polyethylene wax are added.

Abstract: The invention relates to a process for the preparation of bead shaped, expandable polystyrene by the polymerization of styrene in an aqueous suspension in the presence of dimeric .alpha.-methylstyrene as a regulator and a C.sub.3 to C.sub.6 hydrocarbon as a blowing agent, whereby one first reports the content of saturated hydrocarbons, having a boiling point between 70.degree. and 170.degree. C., in the styrene and dimeric .alpha.-methylstyrene, and then enough saturated hydrocarbons, having a boiling point from 70.degree. to 170.degree. C., are added before, during or after the polymerization so that their total content in the suspension is from 0.1 to 0.8 weight percent, based on the styrene.

Abstract: Bead-form, expandable styrene polymers containing, based on the styrene polymer, from 0.005 to 1.5% by weight of polyethylene wax and from 0.005 to 1% by weight of dimeric .alpha.-methylstyrene, and a process for the preparation thereof.

Abstract: The invention relates to a process for the preparation of CFC-free, flexible polyurethane foams or molded foams by reactingA) liquid polyisocyanate mixtures containing bonded urethane groups and having a content of NCO groups of from 20 to 30% by weight, these mixtures themselves being prepared by reacting a mixture of diphenylmethane diisocyanates and polyphenyl-polymethylene polyisocyanates (crude diphenylmethane diisocyanate) with a polyether-polyol mixture, having a hydroxyl number of from 120 to 25, of at least one polyoxypropylene glycol and at least one trifunctional polyoxypropylene-polyoxyethylene glycol having a content of ethylene oxide units of from 90 to 10% by weight or by reacting 4,4'-diphenylmethane diisocyanate (diphenylmethyl diisocyanate) or an diphenylmethane diisocyanate isomer mixture with said polyether-polyol mixture to give an NCO-containing quasi-prepolymer and diluting this quasi-prepolymer with crude diphenylmethane diisocyanate, withB) relatively high-molecular-weight polyhydroxy