Abstract: Cellular Polyurethane elastomer which is produced by reacting:(a) an isocyanate component which includes methylenebis(phenyl isocyanate) (MDI) and/or tolylene diisocyante (TDI), in monomeric form or as liquefied prepolymer with(b) compounds which at least two isocyanate-reactive hydrogen atoms and(c) 4,4'-methylenebis(3-chloro-2,6-dialylaniline) or a mixture of 4,4'-methylenebis-(3-chloro-2,6-dialyaniline) with one or more aromatic, aliphatic or cycloaliphatic diamines as chain extending agent, if desired with further polyol, and(d) a blowing agent in the presence of the usual catalysts and, if desired, other additives.

Abstract: The invention is a process for the preparation of elastic polyurethane flexible foams having densities from approximately 25 to 60 kg/m.sup.3, and producing molded articles in closed molds at temperatures from 25.degree. to 80.degree. C., comprising reacting(A) an organic polyisocyanate prepolymer having an isocyanate content from 6 to 20 percent by weight prepared by reacting a toluene diisocyanate and/or a diphenylmethane diisocyanate with a di- to tetrafunctional polyether polyol having a hydroxyl number from 20 to 50 and oxyethylene terminal group content of at least 10 to 30 percent by weight(B) a mixture of compounds containing reactive hydrogen atoms, comprising a mixture of(a) from 55 to 89.5 parts by weight of at least one di- to tetrafunctional polyether polyol having a hydroxyl number of from 20 to 80 and less than 10 percent by weight terminal oxyethylene groups,(b) from 0.

Abstract: Stable melamine-polyoxyalkylene polyether polyol dispersions are prepared by the in situ reduction of melamine particles wherein 90 percent of the melamine particles have a particle size of less than 10 microns. Stabilizers for the melamine-polyol dispersion are selected from the group consisting of(a) silicic acids and silicates,(b) salts of perfluorinated alkyl carboxylic acids having 4 to 20 carbon atoms, salts of alkyl sulfonic acids and perfluorinated alkylsulfonic acids having 4 to 20 carbon atoms and polyperfluoroether polyols having molecular weights of 300 to 6000, and(c) salts of fatty alcohol sulfates having 6 to 30 carbon atoms.These dispersions are useful for the preparation of polyurethane foams.

Abstract: A process for separating hydrophobic organic liquids from water comprising passing a mixture of water and hydrophobic organic liquids through a column-like vessel which is filled with a hydrophobic, preferably open-celled, polyurethane foam, said foam having a high absorption capacity, permits high flow-through velocities even as the foam becomes covered and saturated with the hydrophobic organic liquids, is reversibly deformable, and can be reused.

Abstract: The invention concerns a process for the manufacture of flame resistant flexible polyurethane foams by reacting a mixture of diphenylmethane diisocyanates and polyphenylene polymethylene polyisocyanates having a functionality greater than 2 containing 40 to 90 percent by weight diphenylmethane diisocyanate based on the total weight of said mixture; polyols, cyanic acid derivatives such as cyanamide, dicyandiamide, guanidine, biguanidine, melamine, cyanuric alkyl esterhydrazides and -amides as flame inhibitors, and blowing agents; as well as, possibly, chain extenders and other additives. The flexible polyurethane foams are suited for the familiar areas of applications, but especially as sound-insulation material for the construction industry.

Abstract: This invention concerns a process for the manufacture of flexible polyurethane foams from urethane-modified aromatic polyisocyanates having an NCO content of 15 to 30 percent by weight and a viscosity of 100 to 2000 centipoises at 20.degree. C., which are obtained by reaction of a mixture of diphenylmethane diisocyanates and polyphenylene polymethylene polyisocyanates containing 55 to 85 percent by weight of diphenylmethane diisocyanate based on the total weight of the polyisocyanate mixture and a hydroxyl compound with 2 to 4 Zerewitinoff active hydrogen atoms and a molecular weight of 60 to 1500, in an equivalency ratio of NCO groups to active hydrogen atoms of the hydroxyl compound of 2:1 to 60:1, polyols, catalysts, blowing agents, and optionally, chain extenders, auxiliaries, and additives.

Abstract: A process for the manufacture of partially dehydrated organic polymer polyol dispersions from the reaction of polyhydroxyl compounds and aqueous polymer dispersions wherein the problem of excessive viscosity is overcome by mixing the reactants with a recycled partially dehydrated polyol polymer dispersion, removing water from the reaction mixture, removing a portion of the partially dehydrated polyol polymer dispersion, and recycling the remainder.

Abstract: The invention relates to a process for the manufacture of reinforced polyurethane foams based on the reaction of organic polyisocyanates and polyols in the presence of filler dispersions. These dispersions are prepared by in situ crushing of the filler in the polyisocyanate or polyol to a particle size of less than 7 microns.

Abstract: The invention concerns a process for the manufacture of flexible polyurethane foams by reaction of a mixture consisting of diphenylmethane diisocyanates and polyphenylene polymethylene polyisocyanates having a functionality greater than 2 containing 55 to 85 percent by weight diphenylmethane diisocyanate based on the total weight of the isocyanate mixture with polyester polyols or mixtures of polyester polyols and polyether polyols having a polyester polyol content of more than 60 percent by weight based on the weight of the polyol mixture, and optionally chain extenders, auxiliaries, and additives, in the presence of catalysts and, in particular, water as a blowing agent. The special selection of starting compounds results in the production of flexible polyurethane foams having a high resistance to hydrolysis, high load-bearing capacity, and high energy absorption upon impact.

Abstract: Hydrophobic polyurethane foams which have densities of from 4 to 15 g/liter and in which the number of closed cells is from 2 to 30%, and the number of open cells from 98 to 70%, based on the total number of cells, are obtained from polyisocyanates, polyhydroxy compounds, catalysts and water, with or without lipophilic compounds, the components being reacted in such amounts that the ratio of hydrogen atoms capable of undergoing a Zerewitinoff reaction to NCO groups is from 1.3 to 10:1. The foams are suitable for the absorption of oil and/or by hydrophobic solvents, which may or may not contain halogen, from water.