Abstract: The invention relates to the preparation of isocyanates by phosgenation of amines in the gas phase, with these isocyanates having a comparatively low proportion of color-imparting compounds.

Abstract: An isocyanate is produced by reacting an amine with a stoichiometric excess of phosgene in the gas phase. This reaction is carried out at a temperature above the amine's boiling point to obtain a liquid stream containing the isocyanate and a gas stream containing hydrogen chloride and phosgene. The gas stream containing hydrogen chloride and phosgene thus produced is separated into a gas stream containing hydrogen chloride and a liquid stream containing phosgene. At least part of the liquid stream containing phosgene is then converted to a gas stream containing phosgene which gas stream is then recycled. The gaseous phosgene stream is maintained at a higher pressure than the liquid phosgene stream.

Abstract: Processes comprising providing an amine reactant, and reacting the amine reactant with a stream of phosgene in a reaction zone to form a product comprising a corresponding isocyanate, wherein the phosgene stream has a CO content of 0.5% by weight or more.

Abstract: An isocyanate is produced by reacting an amine with a stoichiometric excess of phosgene in the gas phase. This reaction is carried out at a temperature above the amine's boiling point to obtain a liquid stream containing the isocyanate and a gas stream containing hydrogen chloride and phosgene. The gas stream containing hydrogen chloride and phosgene thus produced is separated into a gas stream containing hydrogen chloride and a liquid stream containing phosgene. At least part of the liquid stream containing phosgene is then converted to a gas stream containing phosgene which gas stream is then recycled. The gaseous phosgene stream is maintained at a higher pressure than the liquid phosgene stream.

Abstract: Isocyanates are produced by reaction of primary amines with phosgene in the gas phase. In this process, the reaction is terminated by guiding the reaction mixture from the reaction chamber through a cooling stretch into which liquids are injected. Direct cooling takes place in the cooling stretch in one stage in two or more cooling zones connected in series.

Abstract: The invention relates to the preparation of isocyanates by phosgenation of amines in the gas phase, with these isocyanates having a comparatively low proportion of color-imparting compounds.

Abstract: An isocyanate is produced by reacting a primary amine with phosgene in the gas phase above the boiling point of the amine over an average contact time of 0.05 to 15 seconds under adiabatic conditions.

Abstract: Processes comprising providing an amine reactant, and reacting the amine reactant with a stream of phosgene in a reaction zone to form a product comprising a corresponding isocyanate, wherein the phosgene stream has a CO content of 0.5% by weight or more.

Abstract: Isocyanates are produced by reaction of primary amines with phosgene in the gas phase. In this process, the reaction is terminated by guiding the reaction mixture from the reaction chamber through a cooling stretch into which liquids are injected. Direct cooling takes place in the cooling stretch in one stage in two or more cooling zones connected in series.

Abstract: An isocyanate is produced by reacting a primary amine with phosgene in the gas phase above the boiling point of the amine over an average contact time of 0.05 to 15 seconds under adiabatic conditions.

Abstract: The present invention relates to a process for the production of an isocyanate corresponding to the formula R(NCO)n wherein R represents a (cyclo)aliphatic or aromatic hydrocarbon residue having up to 15 carbon atoms, preferably 4 to 13 carbon atoms, provided that there are at least 2 carbon atoms arranged between each of the nitrogens and n represents the number 2 or 3, by a) separately heating an amine corresponding to the formula R(NH2)n, wherein R and n are as previously defined, in vapor form, optionally diluted with an inert gas or the vapors of an inert solvent, and phosgene to temperatures of 200° C. to 600° C.

Abstract: The invention relates to a process for the preparation of isocyanates in the gas phase, in which the possibilities for back-mixing and byproduct formation are reduced by improving the mixing of the starting materials in a tubular reactor.

Abstract: The invention relates to a process for the preparation of isocyanates in the gas phase, in which the possibilities for back-mixing and byproduct formation are reduced by improving the mixing of the starting materials in a tubular reactor.

Abstract: The present invention relates to a process for preparing (cyclo)aliphatic diisocyanates and triisocyanates corresponding to the formula R—(NCO)n??(I), wherein R represents a (cyclo)aliphatic hydrocarbon group having up to 15 carbon atoms, provided that there are at least two carbon atoms between two nitrogens, n represents the number 2 or 3, by a) separately heating phosgene and a diamine or triamine corresponding to the formula R—(NH2)n??(II), ?to a temperature of 200° C. to 600° C., wherein the amine may optionally be diluted with an inert gas or with the vapors of an inert solvent, b) optionally passing the reactants over torque-producing baffles and c) continuously reacting phosgene and the amine in the gas phase in a reaction chamber without moving parts and with constrictions of the walls in the region of the reaction zone.

Abstract: Isocyanates are produced in the gas phase in a manner such that temperature fluctuations over time and temperature distribution asymmetry are prevented. In this improved process, performance of the reaction in tubular reactors is accomplished by flow-related measures such as homogenization and centering of the educt streams. The formation of polymeric secondary products, which result in baked-on deposits in the reactor and a reduction in reactor service life, is consequently prevented.

Abstract: The present invention provides a process for quenching a gaseous reaction mixture during the phosgenation of diamines in the gas phase to produce diisocyanates. The gaseous reaction mixture contains at least a diisocyanate, phosgene and hydrogen chloride. The quenching liquid is injected into the gas mixture continuously flowing out of a cylindrical reaction zone into the downstream cylindrical quenching zone with the aid of at least two spray nozzles which are arranged at the entrance to the quenching zone at equal distances along the circumference of the quenching zone.

Abstract: The present invention provides a process for quenching a gaseous reaction mixture during the phosgenation of diamines in the gas phase to produce diisocyanates. The gaseous reaction mixture contains at least a diisocyanate, phosgene and hydrogen chloride. The quenching liquid is injected into the gas mixture continuously flowing out of a cylindrical reaction zone into the downstream cylindrical quenching zone with the aid of at least two spray nozzles which are arranged at the entrance to the quenching zone at equal distances along the circumference of the quenching zone.

Abstract: The present invention relates to a novel process for preparing (cyclo)aliphatic diisocyanates and triisocyanates by phosgenation of (cyclo)aliphatic diamines and triamines in the gas phase by accelerating the flow of at least one of reactants in the region where the reactants are mixed.

Abstract: Isocyanates are produced in the gas phase in a manner such that temperature fluctuations over time and temperature distribution asymmetry are prevented. In this improved process, performance of the reaction in tubular reactors is accomplished by flow-related measures such as homogenization and centering of the educt streams. The formation of polymeric secondary products, which result in baked-on deposits in the reactor and a reduction in reactor service life, is consequently prevented.

Abstract: The present invention relates to a process for the production of an isocyanate corresponding to the formula R(NCO)n wherein