Abstract: Crude polyisocyanates are purified by extraction at a temperature from 80.degree. to 180.degree. C. to form a two-phase system. The phases are separated and the phase made up of purified polyisocyanate and solvent is cooled to a temperature which is at least 50.degree. C. below the extraction temperature. Upon cooling, a second two-phase system forms. Purified polyisocyanate containing residual solvent is recovered upon separation of these phases. Solvent in which polyisocyanate is present that is reclaimed during this process may be reused in subsequent extractions. The purified polyisocyanates have a viscosity which is lower than that of crude polyisocyanates having substantially the same isocyanate content and average functionality. These purified polyisocyanates are useful in the production of polyurethane foams and moldings as well as adhesives and coatings.

Abstract: Elastic molded articles having a closed surface layer are made from polyurea elastomers by the reaction injection molding technique. These polyurea elastomers are prepared from a polyisocyanate in which all of the isocyanate groups are aromatically bound, a polyether and a diamine. The polyether has at least two isocyanate-reactive groups and a molecular weight from 1800 to 12,000. At least 50% of the isocyanate-reactive groups in the polyether are pjrimary and/or secondary amino groups. The diamine has a molecular weight from 108 to 400 and primary and/or secondary aromatically bound amino groups. Known auxiliary agents and additives may also be employed.

Abstract: The present invention is directed to flame retardant, pigmented polycarbonate molding compositions which properties include both good flame resistance properties and virtual freedom from streaking. The compositions are particularly suitable for use in molding machines using hot runner tools. The composition of the invention comprise a thermoplastic aromatic polycarbonate resin, a flame retarding agent, pigments, polytetrafluoroethylene--ASTM Type 3--and an amount of finely divided hydrophobic silicon dioxide sufficient for providing streaking-free molded articles.

Abstract: The present invention is directed to a process for the production of light-resistant, optionally foamed elastomeric molded polyurethanes by reacting(a) organic polyisocyanates which are either mixtures of isophorone diisocyanate with polyisocyanates containing isocyanurate groups and based on 1,6-diisocyanatohexane or mixtures of IPDI with polyisocyanates containing isocyanurate groups and based on 1,6-diisocyanato-hexane and IPDI with organic compounds containing isocyanate-reactive groups in the presence of catalysts, wherein the components are reacted together inside closed molds in an isocyanate index of about 70 to 130.The present invention is additionally directed to the elastomeric polyurethanes prepared by this process.

Abstract: Flame resistant polyurethane foams are made by reacting a polyisocyanate with a specific polyol composition. This polyol composition is made up of (a) at least 10 wt. % of a polyether formed by the addition of alkylene oxide(s) to 2,3- and/or 3,4-tolylenediamine having an OH number of from 400 to 520, (b) at least 20-50 wt. % flame retardant containing phosphorus and/or halogen, (c) 5-10 wt. % chain lengthening or cross-linking agent, (d) surface active agents, (e) water and (f) 0-30 wt. % polyhydroxyl compound(s) other than (a) having a molecular weight of from 300 to 10,000.

Abstract: The invention relates to a process for the in situ production of dispersions or solutions of urea group-containing aromatic isocyanates by the low temperature reaction of aromatic diisocyanates and/or polyisocyanates (the NCO groups of which preferably exhibit different reactivities) with from 0.15 to 0.4 mols of water per NCO equivalent in relatively high molecular weight polyols and in the presence of catalysts accelerating the NCO/water reaction. Such catalysts are preferably selected from peralkylaminoalkyl ethers, peralkylamino-polyalkylene ethers and/or peralkyl-polyalkylene-polyamines. The present invention also relates to the resulting metastable solutions or dispersions and to the use thereof, optionally with the further addition of relatively high and low molecular weight compounds having hydroxyl, amino or hydrazide groups and with the optional addition of other polyisocyanates in polyurethane-forming ratios for the production of polyurethanes.

Abstract: The present invention is directed to mold release compositions based on a solution which is liquid at room temperature and contains(i) at least one zinc salt of a straight or branched chain, saturated or unsaturated aliphatic carboxylic acid containing 8 to 24 carbon atoms in(ii) at least one organic compound containing tertiary nitrogen atoms which is liquid at room temperature,the zinc salt being present in a quantity of about 10 to 75% by weight, based on the total weight of the composition, characterized in that component (ii) is based on at least one compound corresponding to the formula ##STR1## wherein R', R", R"' and R.sup.iv, which may be identical or different, denote alkyl group containing 1 to 4 carbon atoms or any two of the groups R' and R" or R"' and R.sup.

Abstract: The present invention is directed to a process for the production of optionally cellular, polyurethane elastomer moldings or optionally cellular, rigid structural polyurethanes by reacting a reaction mixture containing(i) a polyisocyanate,(ii) a high molecular weight polymer having at least two isocyanate-reactive groups and having a molecular weight of 400 to about 10,000,(iii) about 5 to 50% by weight, based on the weight of component (ii) of a chain-extender having at least two isocyanate-reactive groups and(iv) about 0.05 to 10 weight percent, based on the weight of components (ii) and (iii) of a salt based on a carboxy functional siloxane and an amidine group-containing compound of the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.

Abstract: The present invention is directed to water dispersible or soluble polyurethanes containing about 0.5 to 30% by weight, based on the weight of the polyurethanes, of ethylene oxide units present in lateral or terminal polyether chains, characterized in that in addition to these ethylene oxide units the polyurethanes contain, as further hydrophilic centers, about 0.1 to 120 milliequivalents, per 100 g of solids content, of carboxylate groups in the form of built-in structural units corresponding to the general formula ##STR1## wherein R denotes an alkyl group having 1 to 4 carbon atoms and the total quantity of carboxylate groups and ethylene oxide units present in lateral or terminal chains is calculated to ensure the solubility or dispersibility of the polyurethanes in water.The present invention also relates to a process for the preparation of these polyurethanes and to their use for coating substrates.

Abstract: The present invention is directed to a process and apparatus for introducing gas into one of at least two free-flowing components which are subsequently mixed to provide a foam-forming free-flowing mixture by transferring the component to have gas dispersed therein from a supply container to a gas loading area, loading the component with gas and returning the component to the supply area, wherein the gas used in the gas loading area is obtained from a gas cushion maintained in the supply container and wherein the gas is compressed to a pressure higher than the pressure in the gas loading area before it is dispersed into the free-flowing component.

Abstract: Phosgene is produced by reacting chlorine and an excess of carbon monoxide in the presence of activated charcoal in a two stage process. In the first stage, the chlorine and carbon monoxide are reacted in a tubular reactor containing activated charcoal at a temperature above 250.degree. C. until 95 to 98% chlorine has reacted. The reaction gases are cooled to a temperature of from 50.degree. to 120.degree. C. and then introduced into a second reactor maintained at 50 to 100.degree. C. where the phosgene-forming reaction is completed. The phosgene leaving the second reactor has a residual chlorine content of less than 50 ppm. The heat generated during phosgene formation is used to produce steam.

Abstract: The invention is directed to a process for the production of polyurethanes suitable for thermoplastic processing comprising mixingI. at least 75% by weight of preformed thermoplastic polyurethane elastomers, or of a blend of(A) substantially bifunctional, compounds(B) substantially bifunctional chain-extending agents(C) organic diisocyanates and optionally(D) lubricants or other known additivessaid blend characterized in that it contains no peroxides and polymerization initiators which decompose into radicals under the effect of actinic light and further in that the molar ratio of the sum of said (A) and said (B) to said (C) is between 0.9 to 1.1, withII. (E) from 4 to 24% by weight of a crosslinking agent andIII. (F) from 0.01 to 3% by weight of a polymerization inhibitor and/or an antioxidant,by adding said II and said III to said I at a temperature below 230.degree. C., and the cooling the mixture to below 130.degree. C.

Abstract: A reinforced, flame retardant molding composition based on polyalkylene terephthalate were found to be imparted an improved level of mold release properties upon the incorporation therein of a sufficient amount of a compound conforming to the structure of ##STR1## wherein R is a hydrocarbon derivative of a polyhydric alcohol preferably ethylene glycol, glycerol or pentaerythritol, R.sub.1 is hydrogen or a lower alkyl, n is about 10 to 30 and x is 2, 3 or 4.

Abstract: The present invention is directed to a process for the production of optionally foamed polyurethanes which are combined or fabricated with another material, comprising reacting compounds with molecular weights from 400 to 10,000 containing at least 2 isocyanate reactive hydrogen atoms with polyisocyanates in the presence of catalysts containing tertiary amino groups and combining or fabricating the resulting polyurethane with another material, characterized in that the catalysts used are diffusion resistant aminoalkanols corresponding to the general formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be identical or different and represent hydrogen or a C.sub.1 -C.sub.6 alkyl group,R.sup.5, R.sup.6, R.sup.7 and R.sup.8 may be identical or different and represent a C.sub.1 -C.sub.6 alkyl group or together form a C.sub.2 -C.sub.6 alkylene group which may contain hetero atoms such as O or NR (R=C.sub.1 -C.sub.4 alkyl), and n and m may be identical or different and represent integers from 1 to 6.

Abstract: The present invention is directed to a stable dispersion of a polyurea and/or a polyhydrazodicarbonamide having a solids content of from 5 to 40%, by weight, in a relatively high molecular weight, hydroxyl group-containing polyether, obtained by continuously reacting:(a) an organic di- and/or polyisocyanate withan amine-functional material selected from the group consisting of (i) primary and/or secondary amino group-containing di- and/or polyamines, (ii) hydrazines, (iii) hydrazides and (iv) mixtures thereof in(c) said polyetherat an equivalent ratio of components (a) to (b) of from 1.051:1 to 1.50:1 in a throughflow mixer in such a quantity that the average residence time of the reaction components in the mixer is less than 10 minutes and collecting the reaction product issuing from the throughflow mixer in a receiver optionally with heating to from 50.degree. to 150.degree. C. and optionally with subsequent stirring. The invention also relates to the production and use of such dispersions.

Abstract: The instant invention is directed to diisocyanates based on diphenylmethane which may be methyl-substituted and which are characterized in particular by isocyanate groups in the 3,4'- and optionally in the 3,2'-position. The instant invention is also directed to a number of independent processes for their production and to their use as isocyanate component in the production of polyurethanes.

Abstract: The present invention is directed to a process for strengthening and sealing geological formations which are moist or contain water, in particular loose stone, by the injection of a mixture which reacts to form polyurethane, characterized in that a polyisocyanate component is injected before injection of the reaction mixture.

Abstract: The present invention is directed to an apparatus for the production of back-foamed cushions from cover materials and foam comprising:(i) a mold comprising an upper mold half and a lower mold half, said lower mold half defining a cavity, the inside surface of which is capable of being covered by said cover material,(ii) a mix head associated with said mold, said mix head capable of introducing foam materials and/or reactants into said mold cavity, and(iii) at least one pressing element for pressing said cover material into said mold cavity, said pressing element having a pressing edge which consists of at least one balanced spring.

Abstract: The present invention is directed to a process for the production of waterproof, fine-cell polyurethane elastomers having a density of about 300 to 800 kg/m.sup.3 by reacting(a) organic polyisocyanates,(b) polyhydroxyl compounds having a molecular weight of about 400 to about 8000,(c) water and, optionally,(d) organic chain-extending agents containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight of 32 to 399,the equivalent ratio of isocyanate groups to NCO-reactive groups in the overall formulation being about 0.90:1 to 1.20:1, characterized in that polysiloxane ionomers are added to the water/crosslinker component in concentrations of about 0.1 to 5% by weight, based on the reaction mixture as a whole.

Abstract: The present invention is directed to a process for the continuous production of elongate hollow bodies or inner linings for such hollow bodies, from a liquid material wherein the peripheral surface of a mandrel rotating about a horizontal or slightly inclined shaft is covered with a separating film and the liquid material is applied to said separating film and the resulting hollow body is continuously drawn from the mandrel in the axial direction of the shaft while observing the solidification speed of the material, the improvement wherein the separating film is applied to the mandrel in the axial direction of the shaft and to an apparatus for the use therein.