Abstract: The invention provides a process for preparing diphenylmethanediamine, comprising the steps of: a) reacting aniline with formaldehyde in the presence of an acid, b) neutralizing the predominant part of the acid with ammonia and/or aqueous ammonia solution, c) separating the reaction mixture from step b) into an aqueous phase and an organic phase, d) neutralizing the other part of the acid, present in the organic phase, with aqueous alkali metal hydroxide solution, e) separating the reaction mixture from step d) into an aqueous phase and an organic phase, f) treating the aqueous phase obtained in step c) or optionally the combined aqueous phases from steps c) and e) with at least one oxide or hydroxide of an alkaline earth metal, g) removing the ammonia obtained in step f).

Abstract: The present invention relates to a process for preparing isocyanates and an apparatus suitable for this purpose, and also its use. In the process, an amine and phosgene, both in the gas phase, react in the presence of an inert medium. A number, n, of amine streams are reacted with a number, n +1, of phosgene streams in a reactor. The number n is a positive integer of at least 1. All amine and phosgene streams are introduced into the reactor through annular gaps for mixing.

Abstract: The present invention encompasses the finding that improvements can be achieved in manufacture of isocyanates through the use of a substitute for or a precursor of phosgene. Methods and compositions utilized in accordance with the present invention can be useful in situations in which it is difficult to use phosgene, and in particular gaseous phosgene. In some embodiments, a substitute for or a precursor of phosgene used in accordance with the present invention for preparing isocyanates is or comprises diphosgene (ClCO2CCl3).

Abstract: Process for preparing isocyanates by phosgenation of amines, wherein phosgene and amine are brought into contact in at least 2 mixing chambers connected in parallel.

Abstract: A process for preparing phenyl iso(thio)cyanates of the formula I in which a compound of the formula II or its HCl adduct is reacted with a phosgenating agent where W is oxygen or sulfur and Ar and A are as defined in claim 1 is described. Moreover, the invention relates to the use of the phenyl iso(thio)cyanates for preparing crop protection agents.

Abstract: Process for preparing isocyanates by phosgenation of amines, wherein phosgene and amine are brought into contact in at least 2 mixing chambers connected in parallel.

Abstract: The present invention provides a flow duct type jet reactor and a process for preparing isocyanates using it. The flow duct type jet reactor situates flow ducts in inner feed pipe which form whirlpool and reinforce vortex, thereby amine steam rapidly admixes and reacts with phosgene, and the byproducts are reduced. In addition, the present process uses a jet-absorption apparatus which rapidly cools the high temperature gas discharged from the reactor to a temperature at which the product is thermally stable, and at the same time provides negative pressure for the reaction process of the system, and thus saving bulky vacuum system.

Abstract: What is proposed is a process for preparation and distillative workup of diphenylmethane diisocyanate (MDI), proceeding from a benzene-comprising feedstream, in which, in a catalytic hydrogenation of nitrobenzene to aniline, steam is raised at two different pressure levels, which partly or completely covers the energy demand for the overall process, by using two fluidized bed reactors of identical design, of which a first fluidized bed reactor is operated with an aniline load for which the fluidized bed reactors have been designed and provides steam at a first, lower pressure level, and a second fluidized bed reactor is operated with a load lowered with respect to the first fluidized bed reactor to such an extent that the second fluidized bed reactor affords steam at the higher pressure level.

Abstract: A process for preparing diisocyanates by gas-phase phosgenation starting out from a feed stream comprising the corresponding diamines and a phosgene-comprising feed stream, in which the feed streams are separately converted into the gas phase and preheated to the reaction temperature of the gas-phase phosgenation, wherein the waste heat from a plant for preparing chlorine by heterogeneously catalyzed oxidation of hydrogen chloride by the Deacon process is utilized for this purpose, is proposed.

Abstract: An isocyanate has been widely used as a starting material for the production of a polyurethane material, a polyisocyanurate material or the like which is suitably applicable to the field of optical materials. Disclosed is a process for producing an isocyanate which includes a step for producing the isocyanate in the form of a hydrochloride with improved productivity. A process for producing a linear or cyclic aliphatic isocyanate comprising the step of reacting a linear or cyclic aliphatic amine with hydrogen chloride to yield a hydrochloride of the linear or cyclic aliphatic amine, the step being performed under a pressure higher by 0.01 MPa or more than the atmospheric pressure.

Abstract: The invention relates to a process for preparing methylenedi(phenyl isocyanate), which comprises (a) the phosgenation of two-ring and/or multiring methylenedi(phenylamine), (b) the fractionation of the crude methylenedi(phenyl isocyanate) obtained to give two-ring and multiring isomers, (c) the purification and/or fractionation of the resulting mixture of two-ring isomers of methylenedi(phenyl isocyanate) and (d) the storage of the mixtures obtained in step (c) or in step (b), wherein part of the stored mixtures is reused by means of recirculation in at least one of steps (b) or (c).

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: The present invention relates to a process for preparing isocyanates.

Abstract: The invention relates to a method of measuring entry of water and resulting corrosion in plants for producing isocyanates by reacting phosgene with one or more primary amines in a solvent. The invention further relates to an apparatus for producing such isocyanates, in the work-up section of which probes for monitoring corrosion are arranged in defined places.

Abstract: Isocyanates are produced by reacting a primary amine with phosgene in the gas phase. In this process, the amine is vaporized and then superheated prior to introduction into the reactor. The amine is superheated to a temperature at least 10° C. above dew point before entry into the reactor. A pressure difference between the vaporizer and entry into the reactor of from 1 to 500 mbar is maintained.

Abstract: The invention relates to a process for preparing isocyanates in the gas phase.

Abstract: The present invention relates to a process for the production of isocyanates, preferably diisocyanates and polyisocyanates of the diphenylmethane series (MDI), by reacting an amine with phosgene in the liquid phase or in the gas phase to form the corresponding isocyanates, subsequent removal of the solvent in at least two steps to obtain at least two solvent streams, individual treatment of the at least two solvent streams, and re-circulation of at least a portion of the solvent streams.

Abstract: Process for preparing isocyanates by reacting the corresponding amines with phos-gene comprising (a) providing at least one amine-comprising feed stream and at least one phosgene-comprising feed stream, (b) mixing the feed streams to form at least one reaction mixture in a mixing zone, (c) reacting the at least one reaction mixture in a reaction zone and (d) working-up the product mixture obtained from (c).

Abstract: An isocyanate is produced by: (a) reacting chlorine with carbon monoxide to form phosgene, (b) reacting the phosgene with an organic amine to form an isocyanate and hydrogen chloride, (c) separating the isocyanate and hydrogen chloride, (d) optionally, purifying the hydrogen chloride, (e) preparing an aqueous solution of the hydrogen chloride, (f) optionally, purifying the aqueous solution of hydrogen chloride, (g) subjecting the aqueous hydrogen chloride solution to electrochemical oxidation to form chlorine, and (h) returning at least a portion of the chlorine produced in (g) to (a).

Abstract: A two-stage process for the preparation of organic isocyanates by reacting primary amines with phosgene in which: a) in a first stage, amine and phosgene are reacted in an adiabatically managed reaction, in which the temperature of reaction is restricted to values between 100 and 220° C. by actively adjusting the absolute pressure in the reactor to values between 8 and 50 bar by decompression, and the temperature is held at values between 100 and 220° C. until the stoichiometric conversion of phosgene has reached at least 80%; and then b) in a second stage, the reaction mixture from a) is decompressed to an absolute pressure of 1 to 15 bar and the reaction mixture is reacted further at temperatures between 90 and 240° C., optionally with the introduction of heat.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, optionally in the presence of an inert medium, in which phosgene and amine are first evaporated and then superheated further to reaction temperature, and the superheated phosgene and amine are mixed and fed to a reactor in which the phosgene and the amine are converted to the isocyanate, wherein the residence time of the phosgene at temperatures greater than 300° C. is not more than 5 s, and/or the temperature of heat transfer surfaces in contact with phosgene is not more than 20 K above the phosgene temperature to be established. The invention further relates to an apparatus for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase.

Abstract: Isocyanates are prepared by a process in which a product stream from the isocyanate synthesis is purified.

Abstract: A process for phosgenating an amine comprising employing a plug-flow type reactor with internal recycle is disclosed. The process can be continuous, which makes it possible to prepare, in a single stage, a (poly)isocyanate with a good yield, without formation of byproducts and on simplifying the plant in order to carry out the process so as to promote safety.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, optionally in the presence of an inert medium, in which the amine is evaporated in an evaporator to give an amine-comprising gas stream, the phosgene is mixed into the amine-comprising gas stream, and the amine and the phosgene are converted to the isocyanate in a reactor, wherein the temperature of surfaces in contact with the gaseous amine is kept above the dew point limit of the amine-comprising gas stream.

Abstract: The present invention relates to a process for the preparation of toluene-diisocyanate. In this process, toluenediamine is reacted with phosgene to give crude toluene-diisocyanate, the crude toluene-diisocyanate is purified by distillation, the distillation residue formed during the distillation is hydrolysed at temperatures of less than 230° C. under absolute pressures of less than 30 bar, and the toluenediamine formed by this process is subsequently recycled into the reaction of toluenediamine and phosgene.

Abstract: The present invention is a process for aliphatic or cycloaliphatic isocyanate. The process comprises reacting an aliphatic or cycloaliphatic primary amine, with phosgene in the presence of an inert solvent wherein the initial reaction temperature is between 100 and 130° C. and the temperature is subsequently ramped to 150 to 180° C. during the course of the reaction, the solvent to amine weight ratio is 95:5 to 80:20, the total reaction pressure is maintained between 50 and 350 psig and the amine is rapidly dispersed in the phosgene through injection in a region of high efficiency mixing.

Abstract: The present invention relates to a process for preparing an isocyanate, comprising hydrogenating a mixture (Gi) comprising an amine in the presence of a hydrogenation catalyst comprising copper to obtain a mixture (Gii) comprising the amine, and reacting the mixture (Gii) with phosgene to obtain a mixture (Giii) comprising the isocyanate. The present invention further relates to the isocyanate preparable by this process.

Abstract: A monomer is provided which is excellent in reactivity, can give high heat resistance and high refractive index, and has two or more polymerizable functional groups with different polymerization properties and an aromatic ring in the molecule. An industrial advantageous process for producing the monomer is also provided. The monomer is an aromatic isocyanate compound containing a (meth)acryloyl group, and is represented by Formula (I): wherein R1 is a single bond or a linear or branched alkylene group of 1 to 5 carbon atoms, R2 is a hydrogen atom or a methyl group, R3 is a single bond or a linear or branched alkylene group of 1 to 3 carbon atoms, X is independently a halogen atom or an electron-withdrawing group, m is an integer ranging from 0 to 4, n is an integer ranging from 1 to 3, and 1?m+n?5.

Abstract: The present invention relates to a process for preparing pentamethylene 1,5-diisocyanate, to pentamethylene 1,5-diisocyanate prepared in this way and to the use thereof.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, optionally in the presence of an inert medium, in which the amine and the phosgene are first mixed and converted to the isocyanate in a reactor, and in which a reaction gas (1) which comprises isocyanate and hydrogen chloride leaving the reactor is cooled in a quench (3) by adding a liquid quench medium (5) to form a mixture of reaction gas and quench medium as the product stream (7). The quench medium (5) used is a mixture which comprises at least one solvent and isocyanate and which is withdrawn from the preparation process, any solid particles present in the quench medium (5) being removed before addition to the quench (3).

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the liquid phase, if appropriate in the presence of at least one inert medium, in which the amine and the phosgene are first mixed in a mixing chamber (1) to give a reaction mixture and the reaction mixture is fed to a reactor, the amine being added through an orifice (3) arranged coaxially to the mixing chamber (1) and the phosgene being added through feed orifices (5) in at least two planes (7, 9) arranged at right angles to the axis (11) of the mixing chamber (1), or the phosgene being added through the orifice (3) arranged coaxially to the mixing chamber and the amine through the feed orifices (5) in at least two planes (7, 9) arranged at right angles to the axis (11) of the mixing chamber (1). At least one plane (9) is arranged upstream and at least one plane (7) downstream of the orifice (3) arranged coaxially to the mixing chamber (1) in main flow direction of the reaction mixture.

Abstract: A method for producing toluene diisocyanate is disclosed which comprises forming a dispersion comprising phosgene gas bubbles dispersed in toluene diamine liquid phase, wherein said gas bubbles have a mean diameter less than 1 micron; and subjecting the dispersion to phosgenation reaction conditions, whereby at least a portion of the toluene diamine is phosgenated to form toluene diisocyanate. A system for carrying out the phosgenation of toluene diamine is also disclosed.

Abstract: The invention relates to a process for preparing isocyanates, comprising (a) the reaction of at least one amine with phosgene in the gas phase in a reaction zone and (b) the subsequent cooling of the reaction gases in a cooling zone by means of indirect cooling, the cooling medium which absorbs the heat of the reaction gases being conducted in countercurrent to the product stream at least in the region of the highest temperature in the cooling zone.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, in the presence or absence of an inert medium, which comprises the following steps: (a) vaporization of the amine in a vaporizer, (b) superheating of the amine, (c) mixing of the gaseous amine with the phosgene and introduction into a reaction zone, (d) reaction of amine and phosgene to give isocyanate in the reaction zone, with a reaction mixture comprising isocyanate and hydrogen chloride being formed, (e) cooling of the reaction mixture comprising isocyanate and hydrogen chloride, wherein the vaporizer comprises a vessel in which tubes through which a heating medium flows are comprised, where number and diameter of the tubes are designed so that the tubes have a specific heat transfer area based on the volume through which the amine flows of at least 300 m2/m3.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, if appropriate in the presence of an inert medium, in which the amine and the phosgene are first mixed and converted to the isocyanate in a reactor, by cooling a reaction gas which comprises isocyanate and hydrogen chloride and leaves the reactor in a quench by adding a liquid quench medium to obtain a mixture of reaction gas and quench medium. The amount of quench medium added is such that the temperature of the mixture of reaction gas and quench medium which is established in the quench is above the dew point of the gas present in the quench.

Abstract: The present disclosure relates, according to some embodiments, to apparatus, systems, and/or methods for fractionating a feed mixture comprising, for example, one or more isocyanates, light components, solvents and/or heavier components. In some embodiments, fractionating an isocyanate feed mixture may comprise distilling the feed mixture in a non-adiabatic fractionating apparatus comprising a prefractionating section and/or column and a main section and/or column, which comprises a rectification section, a side section, and a stripping section. For example, isocyanates may be separated from light component(s), solvent(s) and/or heavier component(s). A fractionating apparatus may be configured and arranged, in some embodiments, as a dividing wall column. According to some embodiments of the disclosure, apparatus, systems, and/or methods may be energy efficient and/or may have a broad operating range.

Abstract: This invention provides a method for purifying a chlorine supply that includes a chlorine component, a bromine component, and nitrogen trichloride. The method includes the steps of introducing the chlorine supply into a vaporizer, heating the chlorine supply in the vaporizer to form a vapor, and introducing the vapor into a distillation system to provide purified chlorine gas, a distillate that includes liquid chlorine and the bromine component, and a bottoms component including the nitrogen trichloride. The method also includes the steps of condensing the vapor in a reflux condenser, heating the condensate in a reboiler, removing the purified chlorine gas from the distillation system, and removing the distillate from the distillation system.

Abstract: The present invention provides a flow duct type jet reactor and a process for preparing isocyanates using it. The flow duct type jet reactor situates flow ducts in inner feed pipe which form whirlpool and reinforce vortex, thereby amine steam rapidly admixes and reacts with phosgene, and the byproducts are reduced. In addition, the present process uses a jet-absorption apparatus which rapidly cools the high temperature gas discharged from the reactor to a temperature at which the product is thermally stable, and at the same time provides negative pressure for the reaction process of the system, and thus saving bulky vacuum system.

Abstract: The invention provides a process for preparing polyisocyanates, comprising the steps of a) reacting amines with phosgene, b) removing hydrogen chloride, excess phosgene and, if appropriate, the solvent from the reaction mixture, c) separating the liquid mixture from step b) into a liquid phase and a gaseous phase, d) working up the gaseous phase from step c) to give the polyisocyanate.

Abstract: The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, if appropriate in the presence of at least one inert medium, the phosgene being passed into a reactor (21) through a first inlet and the amine through a second inlet of an ejector (1). The first inlet and the second inlet open into a mixing zone (17) in which the phosgene and the amine are mixed to give a reaction mixture. The mixing zone (17) is followed downstream by a diffuser (19) in which pressure and temperature of the reaction mixture composed of phosgene and amine are increased.

Abstract: The present invention relates to a process for preparing diisocyanates from diamines and phosgene in the gas phase.

Abstract: The invention relates to a process for preparing polyisocyanates by reacting primary amines with phosgene in the presence of a solvent, wherein ionic liquids are used as solvents.

Abstract: A polyisocyanate production method that can allow effective use of hydrogen chloride produced secondarily in a polyisocyanate production process, while allowing reduction of environmental burdens, and a polyisocyanate production system for performing the polyisocyanate production method. After chlorine is allowed to react with carbon monoxide to produce carbonyl chloride in a carbonyl chloride producing reactor, the carbonyl chloride produced in the carbonyl chloride producing reactor is allowed to react with polyamine in an isocyanate producing reactor to produce polyisocyanate. Then, after hydrochloric gas produced secondarily in the isocyanate producing reactor is purified in a hydrogen chloride purifying column, the purified hydrochloric gas is oxidized in a hydrogen chloride oxidizing reactor to produce chlorine.

Abstract: The present invention provides a method of preparing polymethylene-polyphenyl-polyamine (briefly referred to as polyamine, DAM), in which a high gravity rotating bed is used as the mixing reactor of formaldehyde and aniline hydrochloride, the mixing solution of aniline hydrochloride and circulation solution and the formaldehyde are fed into the high gravity rotating bed reactor proportionally to carry out mixing and condensation reaction under a condition of a very high gravity; the materials leaving the high gravity rotating bed reactor is introduced into a stirred vessel to proceed with the pre-condensation reaction and obtain a condensation solution; and the process steps of heating, molecular rearrangement, neutralization, water washing and purification, etc. are completed to obtain the refined DAM.

Abstract: The present invention relates to a process for the preparation of toluene-diisocyanate. In this process, toluenediamine is reacted with phosgene to give crude toluene-diisocyanate, the crude toluene-diisocyanate is purified by distillation, the distillation residue formed during the distillation is hydrolysed at temperatures of less than 230° C. under absolute pressures of less than 30 bar, and the toluenediamine formed by this process is subsequently recycled into the reaction of toluenediamine and phosgene.

Abstract: A process for preparing phenyl iso(thio)cyanates of the formula I in which a compound of the formula II or its HCl adduct is reacted with a phosgenating agent where W is oxygen or sulfur and Ar and A are as defined in claim 1 is described. Moreover, the invention relates to the use of the phenyl iso(thio)cyanates for preparing crop protection agents.

Abstract: Process for preparing isocyanates by phosgenation of amines, wherein phosgene and amine are brought into contact in at least 2 mixing chambers connected in parallel.

Abstract: The invention relates to a process for preparing polyisocyanates by reacting organic amines with phosgene, wherein the reaction is carried out in at least three stages, with the first stage being carried out in a mixing apparatus, the second stage in at least one residence apparatus and the third stage in at least one separation apparatus and the pressure in each successive stage being lower than that in the previous stage.

Abstract: The present invention relates to a process for the phosgenation of amines in the gas phase, in which a specific type of heat exchanger is used for vaporizing the amines.

Abstract: The present invention relates to a process for preparing isocyanates.