Abstract: The invention relates to a process for producing polyether carbonate polyols through an addition reaction of alkylene oxides and carbon dioxide onto one or more H-functional starter substances in the presence of a double metal cyanide catalyst or in the presence of a metal complex catalyst based on the metals zinc and/or cobalt, characterized in that one or more H-functional starter substances containing at least 1000 ppm of component (K) is/are continuously metered into the reactor during the reaction, where component (K) is selected from at least one compound containing a phosphorus-oxygen bond and a phosphorus compound that can form one or more P—O bonds through reaction with OH-functional compounds.

Abstract: The present invention relates to the use of a component A for the production of colour-stable polyurethane foams, containing A1?50 to ?100 weight parts of at least one polyether carbonate polyol with a hydroxyl number from ?20 mg KOH/g to ?300 mg KOH/g according to DIN 53240, A2?50 to ?0 weight parts of at least one polyether polyol with a hydroxyl number from ?20 mg KOH/g to ?250 mg KOH/g according to DIN 53240, wherein the polyether polyol is free from carbonate units, A3 0.5 to 25 weight parts, based on the sum of the weight parts of components A1 and A2, water and/or physical propellants, A4 0 to 10 weight parts, based on the sum of the weight parts of components A1 and A2, at least one antioxidant, A5 0 to 10 weight parts, based on the sum of the weight parts of components A1 and A2, adjuvants and additives, wherein all weight part data of the components A1 to A5 are scaled such that the sum of the weight parts A1+A2 is 100 in the composition.

Abstract: An isocyanate-terminated prepolymer C having an NCO content of from ?26% by mass to ?31.0% by mass is obtainable from the reaction of an isocyanate composition A having a viscosity at 25° C. of from ?60 mPas to ?800 mPas, comprising from ?25% by mass to ?60% by mass MDI and from ?40% by mass to ?75% by mass pMDI, wherein the sum of the amounts of those components is ?100% by mass, with a bifunctional polyester ether polyol B having an OH number of ?200 mg(KOH)/g and ?500 mg(KOH)/g, obtained from the reaction of a dicarboxylic acid/dicarboxylic acid derivative with at least one polyol and with an epoxide, wherein the polyester ether polyol B is used in amounts of from ?1.5% by mass to ?6.0% by mass, based on the sum of the masses of A and B. The invention further provides a PUR/PIR polymer produced from the prepolymer C, its use and composite elements based thereon.

Abstract: The invention relates to a process for producing polyether carbonate polyols through an addition reaction of alkylene oxides and carbon dioxide onto one or more H-functional starter substances in the presence of a couble metal cyanide catalyst or in the presence of a metal complex catalyst based on the metals zinc and/or cobalt, characterized in that one or more H-functionalstarter substances containing at least 1000 ppm of component (K) is/are continuously metered into the reactor during the reaction, where component (K) is selected from at least one compound containing a phosphorus-oxygen bond and a phosphorus compound that can form one or more P—O bonds through reaction with OH-functional compounds.

Abstract: The present invention relates to a process for producing flexible polyurethane (PUR) foams with high comfort value and low hysteresis losses produced by reacting organic polyisocyanates containing di- and polyisocyanates of the diphenylmethane (MDI) group with polyoxyalkylene polyethers.

Abstract: Aromatic amines are produced by adiabatic hydrogenation of nitroaromatic compounds in the gas phase on one or more fixed catalysts. The nitroaromatic reactant is passed over the catalyst under pressure and at elevated temperature with hydrogen, water, optionally nitrogen and substantially in the absence of the aromatic amine produced from the nitroaromatic.

Abstract: The present invention relates to the technical field of isocyanates. The present invention provides a method for preparing NCO prepolymers by reacting a stoichiometric excess of an organic isocyanate with an isocyanate-reactive component, the reaction components being mixed together and the mixture being introduced directly into a storage or transport vessel, where it reacts to completion.

Abstract: An isocyanate-terminated prepolymer C having an NCO content of from ?26% by mass to ?31.0% by mass is obtainable from the reaction of an isocyanate composition A having a viscosity at 25° C. of from ?60 mPas to ?800 mPas, comprising from ?25% by mass to ?60% by mass MDI and from ?40% by mass to 75% by mass pMDI, wherein the sum of the amounts of those components is ?100% by mass, with a bifunctional polyester ether polyol B having an OH number of ?200 mg(KOH)/g and ?500 mg(KOH)/g, obtained from the reaction of a dicarboxylic acid/dicarboxylic acid derivative with at least one polyol and with an epoxide, wherein the polyester ether polyol B is used in amounts of from ?1.5% by mass to ?6.0% by mass, based on the sum of the masses of A and B. The invention further provides a PUR/PIR polymer produced from the prepolymer C, its use and composite elements based thereon.

Abstract: The present invention relates to the technical field of isocyanates. The present invention provides a method for preparing NCO prepolymers by reacting a stoichiometric excess of an organic isocyanate with an isocyanate-reactive component, the reaction components being mixed together and the mixture being introduced directly into a storage or transport vessel, where it reacts to completion.

Abstract: The invention relates to polyurethanes that can be obtained by reacting a prepolymer based on diphenylmethane diisocyanate (MDI) with compounds that have NCO-reactive groups, and to use thereof.

Abstract: The invention relates to a process for the preparation of liquid, storage-stable isocyanate mixtures which are characterized by a low color number and which contain carbodiimide (CD) and/or uretonimine (UI) groups. This invention also relates to the isocyanate mixtures obtained by this process, to their use for the preparation of blends with further isocyanates, and to the preparation of prepolymers containing isocyanate groups and of polyurethane plastics, preferably polyurethane foams from these isocyanate mixtures.

Abstract: The invention relates to a process for the production of liquid, storage-stable isocyanate mixtures with a low color index having carbodiimide-(CD) and/or uretone imine (UI) groups, the isocyanate mixtures that can be obtained by this process and their use for the production of blends with other isocyanates or for the production of isocyanate group-containing pre-polymers and also of polyurethane plastics, preferably polyurethane foamed plastics.

Abstract: The invention relates to a method for determining the isomer composition in an isocyanate isomer mixture, wherein a spectrum of the isomer mixture is recorded and the spectrum is entered into a chemometric calibration model.

Abstract: The present invention relates to a process for the production of MDI fractions containing 2,4?-MDI, and in which the 2,2?-MDI component from the MDA production is largely removed from the isomer mixture. Highly reactive monomeric MDI products can be produced in this way. These MDI products are characterised in their processing by significantly reduced emissions of MDI monomers.

Abstract: Aromatic amines are produced by adiabatic hydrogenation of nitroaromatic compounds in the gas phase on one or more fixed catalysts. The nitroaromatic reactant is passed over the catalyst under pressure and at elevated temperature with hydrogen, water, optionally nitrogen and substantially in the absence of the aromatic amine produced from the nitroaromatic.

Abstract: The invention provides a process for the preparation of polyamines of the diphenylmethane series. This process comprises a) reacting aniline and formaldehyde in a molar ratio of 1.5:1 to 6:1, in the presence of an acid catalyst at temperatures of 20° C. to 100° C., in which the water content in the acid reaction mixture is <20 wt. % and a degree of protonation of <15% is established, and b) increasing the temperature of the reaction to a temperature of 110° C. to 250° C. when the ratio of the weight contents of p-aminobenzylaniline to 4,4?-MDA in the reaction mixture falls below a value of 1.00.

Abstract: The invention provides a process for the preparation of polyamines of the diphenylmethane series. This process comprises a) reacting aniline and formaldehyde in a molar ratio of 1.5:1 to 6:1, in the presence of an acid catalyst at temperatures of 20° C. to 100° C., in which the water content in the acid reaction mixture is <20 wt. % and a degree of protonation of <15% is established, and b) increasing the temperature of the reaction to a temperature of 110° C. to 250° C. when the ratio of the weight contents of p-aminobenzylaniline to 4,4?-MDA in the reaction mixture falls below a value of 1.00.

Abstract: The invention relates to a process for the production of liquid, storage-stable isocyanate mixtures with a low color index having carbodiimide-(CD) and/or uretone imine (UI) groups, the isocyanate mixtures that can be obtained by this process and their use for the production of blends with other isocyanates or for the production of isocyanate group-containing pre-polymers and also of polyurethane plastics, preferably polyurethane foamed plastics.

Abstract: The invention relates to a method of producing polyisocyanates of the diphenylmethane series including the steps of a) reacting aniline and formaldehyde in the presence of HCl to provide a product mixture containing polyamines of the diphenylmethane series, HCl, aniline and water; b) removing excess aniline and water by distillation to provide a product mixture comprising polyamines of the diphenylmethane series, HCl, no more than 10 wt. % aniline based on the polyamines, and no more than 5 wt. % water based on the polyamines; and c) phosgenating the product mixture in (b).

Abstract: A fraction of diisocyanates of the diphenylmethane series containing at least 95 wt. % binuclear methylenediphenyl diisocyanate is obtained by a) reacting aniline and formaldehyde in the presence of an acid catalyst to produce diamines and polyamines of the diphenylmethane series containing binuclear methylenediphenyl diamine, b) phosgenating the diamines and polyamines produced in a), optionally in the presence of a solvent, to produce a crude diisocyanate and polyisocyanate, and c) separating a fraction containing at least 95 wt. % binuclear methylenediphenyl diisocyanate with a 4,4?-MDI content of over 60 wt. %, a 2,4?-MDI content of 4 to 35 wt. % and a 2,2?-MDI content of 0.01 to 10 wt. %, relative to the mass of the fraction, and a maximum of 20 ppm phenyl isocyanate and optionally a maximum of 50 ppm solvent from the crude diisocyanate and polyisocyanate produced in b) in a single distillation step with optional upstream and/or downstream separation of low-boiling components.