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

Abstract: In a process for preparing mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates having a reduced content of chlorinated by-products and a reduced iodine color number by two-stage reaction of the corresponding mixtures of diphenylmethanediamines and polyphenylpolymethylenepolyamines with phosgene in the presence of at least one inert organic solvent at elevated temperature, separation of the excess phosgene and solvent after the phosgenation is complete and thermal treatment of the reaction product, the mass ratios of phosgene to hydrogen chloride in the residence time apparatus of the second stage of the phosgenation are at the same time 10-30:1 in the liquid phase and 1-10:1 in the gas phase.

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: A description is given of polyisocyanates of the formula I 1

Abstract: The present invention relates to a process for preparing (cyclo)aliphatic diisocyanates and triisocyanates corresponding to the formula

Abstract: A process for preparing methylenedianiline by reacting aniline with formaldehyde in the presence of acid catalysts comprising, in a semicontinuous process, introducing aniline with or without acid catalyst, feeding formaldehyde with or without acid catalyst through a mixing element into a circuit in which aniline with or without acid catalyst and with or without previously added formaldehyde is circulated and, after feeding in at least 50% of the total amount of formaldehyde to be fed in, heating the reaction mixture to a temperature above 75° C. In addition, the invention relates to a process for preparing polyisocyanates by phosgenation of amines obtainable in this manner and to the polyisocyanates obtainable by this process.

Abstract: A method for making an aliphatic diisocyanate by (a) phosgenating an aliphatic diamine in the presence of an inert solvent or gas to form a crude reaction mixture; (b) distilling the crude reaction mixture to form an aliphatic diisocyanate production stream and an aliphatic diisocyanate waste stream; (c) introducing the aliphatic diisocyanate waste stream to a chamber and placing the waste stream under supercritical fluid conditions sufficient to dissolve an appreciable amount of the aliphatic diisocyanate component in the supercritical fluid; (d) separating the dissolved aliphatic diisocyanate component from the waste stream, wherein the remaining waste stream is a supercritically-purged aliphatic diisocyanate waste stream; (e) lowering the pressure sufficiently to precipitate the aliphatic diisocyanate component.

Abstract: Mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (raw MDI) having a reduced iodine color number and a reduced chlorine content are prepared by reacting the corresponding mixtures of diphenylmethanediamines and polyphenylpolymethylenepolyamines with phosgene in the presence of at least one inert organic solvent at elevated temperature, and then, after phosgenation is complete, incorporating into the reaction mixture, in the presence or absence of the phosgene, a mixture of water and at least one monohydric or polyhydric polyoxyalkylene alcohol, preferably having a functionality of from 2 to 3, and advantageously having a hydroxyl number of from 20 to 1800, in an effective amount which advantageously comprises from more than 0.01 to 0.3% by weight of water (i) and from 0.

Abstract: A process for rapidly mixing phosgene and an amine in the gas phase to produce the corresponding isocyanate. Micro-structure mixers are used for the rapid mixing. The educts emerge from the micro-structure mixer in the form of thin free jets which mix very rapidly by diffusion and/or turbulence. As a result, the mixing operation is accelerated substantially as compared with conventional reactors. The isocyanate yield is also increased.

Abstract: A process for lightening (or decreasing) the color of diphenylmethane diisocyanate by irradiation with light having a wavelength of from 250 nm to 2,500 nm is described. This invention also relates to the use of this brightened diphenylmethane diisocyanate as the isocyanate component in a process for the production of polyurethane plastics by the isocyanate polyaddition process.

Abstract: Isocyanates are prepared by a continuous process by reacting appropriate primary amines with phosgene in the presence of an isocyanate as solvent, the primary amine optionally dissolved in an inert organic solvent being reacted with phosgene, which is dissolved in the isocyanate, at temperatures of 60 to 150.degree. C. and at pressures of 1 to 30 bar (10.sup.5 to 3.10.sup.6 Pa) to obtain the corresponding isocyanate, wherein the molar ratio of phosgene to amine used is 4:1 to 1:1, and the isocyanate used as solvent is solids-free and has a value for hydrolysable chlorine of less than 2%.

Abstract: In a process for preparing isocyanates having a light color by reacting the corresponding amines with phosgene, the amines are treated with solid inorganic substances containing Lewis acid and/or Bronsted acid centers prior to the reaction with the phosgene.

Abstract: Toluylene diisocyanate is produced by nitration of toluene toy yield dinitrotoluene, hydrogenation of the dinitrotoluene, optionally in the presence of a solvent or diluent, to yield a crude solution of toluylene diamine and reaction water, processing the crude solution of toluylene diamine and water to yield an intermediate mixture of toluylene diamine and water wherein the processing is interrupted to result in a water content of about 1-40% by weight, preferably about 2-10% by weight of the intermediate mixture, transporting this intermediate mixture from a first production facility to a second production facility, whereat the intermediate mixture of TDA and water is completed to yield dry toluylene diamine of commercial quality, and followed by phosgenation of the toluylene diamine to give toluylene diisocyanate. It is optional to additionally process the dry toluylene diamine prior to phosgenation.

Abstract: The present invention relates to mixtures of cycloaliphatic diisocyanates corresponding to formula 1) ##STR1## wherein R represents a saturated, linear, aliphatic hydrocarbon residue having 8 to 15 carbon atoms.The present invention also relates to a process for the preparation of these diisocyanate mixtures and to their use for the production of polyisocyanate addition products.

Abstract: The invention relates to a novel process for the preparation of acyl isocyanates which consists in reacting oxalyl chloride with an N-trialkylsilylcarboxamide or an N,N-bis(trialkylsilyl)carboxamide.The process makes it possible to obtain acyl isocyanates in good yield, in particular acyl isocyanates derived from aliphatic amides, and under simplified reaction conditions.

Abstract: The 4,4'-methylene-bis-(3-chloro-2,6-dialkylphenylisocyanates) of the general formula ##STR1## are new polyisocyanates for the production of PU systems with high chemical stability and good thermal stability.

Abstract: A method of phosgenation while using carbonyl chloride produced from chlorine and contaminated carbon monoxide. The obtained contaminated carbonyl chloride is purified prior to being delivered to the phosgenation process. The carbonyl chloride is purified by absorption in a solvent and the obtained carbonyl chloride solution is used for the phosgenation reaction. The carbonyl chloride is conveniently purified in an absorption column which is also used to recover carbonyl chloride from waste gases deriving from the phosgenation process, wherein the solution of fresh and recovered carbonyl chloride is delivered commonly to the phosgenation process.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to the use thereof.

Abstract: Aromatic polyisocyanates are prepared by reacting at least one compound (A), containing at least two primary amine functions and at least one aromatic nucleus, with a relatively modest quantity of phosgene, in the gaseous phase, the amount of phosgene ranging from the stoichiometric amount to a stoichiometric excess of 100% with respect to the number of moles of amine functions of compound (A), carried out in a mixed reactor which comprises a first, homogenizing zone constituting from 20% to 80% of the total volume thereof, and a second, essentially piston flow downstream zone constituting from 80% to 20% of the total volume thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and their use.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to their use.

Abstract: The invention relates to a process for the fractionation and purification of mixtures of aromatic polyamines and to the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to the use thereof.

Abstract: The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and the use thereof.

Abstract: Triisocyanates are produced by gas phase phosgenation of the corresponding (cyclo)aliphatic triamines having three primary amine groups.

Abstract: Organic isocyanates are continuously prepared by reacting primary organic amines with phosgene in the presence of an inert, organic solvent, with the reaction mixture being circulated by means of a bubble column at a temperature of from 60.degree. to 100.degree. C. and with the ratio of the quantity of the circulated amine reaction products to the quantity of the amine supplied of from 100:1 to 5:1.

Abstract: Isocyanates or isocyanate mixtures which contain no appreciable amounts of color causing materials are produced by phosgenating the amine corresponding to the desired isocyanate and treating the isocyanate-containing phosgenation mixture with hydrogen in the presence of a supported catalyst. The supported catalyst is in a form such that its shortest dimension is from about 0.3 to about 3.0 mm. This catalyst has a BET surface of from about 0.5 to about 150 m.sup.2 /g. No alkali material can be present in the catalyst. These isocyanates are particularly useful for the production of light-colored foams.

Abstract: Diisocyanates containing carboxylic acid ester groups corresponding to the formula: ##STR1## in which R and R.sup.1 represent specified groups are produced by phosgenation of the corresponding diamines, optionally present in the form of an ammonium salt. These diisocyanates are useful as starting materials in the production of plastics containing urethane and/or urea groups and as starting materials for the production of intermediate products used for the production of such plastics.

Abstract: A process is provided for the preparation of an aliphatic polyisocyanate. Upon reacting an aliphatic polyamine or its hydrochloride or carbonate with phosgene in an inert liquid medium, the reaction is conducted while charging an inert gas into a reaction system.

Abstract: Diisocyanates are produced by gas-phase phosgenation of aliphatic diamines having two primary amino groups in the 1,2- or 1,3-position to one another or by cycloaliphatic diamines having two primary amino groups in the 1,2- or 1,3-position to one another.

Abstract: A continuous process for the preparation of aromatic diisocyanates by phosgenation of the corresponding diamines, in which the reaction is carried out in the gas phase. The mean contact time for the gaseous reactants is from 0.5 to 5 seconds with a mean deviation of no more than 6%. The product diisocyanate is obtained in yields of over 95%.

Abstract: Aromatic polyisocyanates, e.g., toluene diisocyanate, are prepared by reacting/contacting at least one aromatic compound (A) bearing at least two primary amine substituents, e.g., toluenediamine, xylylenediamine and/or phenylenediamine,, with phosgene, in gaseous phase and in a reactor/reaction zone devoid of active mechanical stirring.

Abstract: The invention concerns a process for the preparation of acyl isocyanates which consists of reacting oxalyl chloride with a salt selected from the group consisting of hydrohalides and sulphates of carboxamides and/or carbamates, unsubstituted on nitrogen, then heating the reaction mixture at a temperature between 30.degree. and 150.degree. C. The process is suitable for preparation of acyl isocyanates with excellent yields in easy to control operational conditions.

Abstract: The hue of a methylene-crosslinked polyphenylene polyisocyanate continuously produced by the reaction with phosgene in an inert solvent of a polyamine mixture obtained by condensation of aniline and formaldehyde in the presence of an acid catalyst is improved by first removing any residual phosgene followed by heat treatment in the presence of hydrogen chloride gas.

Abstract: The invention relates to a process for removing water traces from a liquid phosgene stream in chemical processes which employ a phosgenation step. Water traces are removed from a liquid phosgene stream containing at least 60 weight percent phosgene by contacting the stream with a strongly basic macroreticular anion exchange resin which catalyzes the reaction between phosgene and the water traces.

Abstract: The present invention is directed to a process for the production of polymethylene polyphenyl polyisocyanates by phosgenating the corresponding polyamines in solution in an inert organic solvent, removing excess phosgene, and stripping the solvent. The improvement resides in adding at least 0.02 parts by weight of reducing agent per 150 parts by weight of polyamine to the polyamines at any time prior to the stripping step.

Abstract: Disclosed herein is a process for preparing a reaction product containing methylene diphenylamine comprising reacting aniline with an aldehyde, in the presence of a low level of an acid wherein the acid level is reduced before digesting reaction mixture at a high temperature which is sufficient to effect a rearrangement of the intermediates to produce a reaction product containing methylene diphenylamines and low levels of impurities.

Abstract: Saturated, liquid, low molecular weight and low-viscosity isobutylene polymers terminally functionalized by special groups, which correspond to the following formula ##STR1## are produced by solution ozonolysis of high molecular weight isobutylene/diene copolymers containing diene monomers, stabilization of the products obtained after the ozone treatment by addition of peroxide decomposers and subsequent reduction with hydrogen in the presence of hydrogenation catalysts under pressures of 10 to 300 bar and at temperatures of 20.degree. to 300.degree. C., optionally in the presence of sulfur or amines or ammonia.

Abstract: Herein disclosed are an .alpha.-(aminocyclohexyl)alkylamine represented by the following general formula (II): ##STR1##wherein R represents hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, provided that the amino group bonded to the cyclohexyl group may be in either of the 2-, 3- and 4-positions and a method for preparing it; an .alpha.-(isocyanatocyclohexyl)alkylisocyanate of Formula (II) wherein the amino groups are replaced with isocyanato groups and a method for preparing it; polyisocyanato-isocyanurate represented by the following general formula (IV): ##STR2##wherein R.sub.1, R.sub.2 and R.sub.

Abstract: Mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (crude MDI) having a reduced iodine color number are prepared by reacting the corresponding mixtures of diphenylmethanediamines and polyphenylpolymethylene-polyamines with phosgene in the presence of one or more inert organic solvents at elevated temperatures by a process in which low molecular weight alkanols, polyhydric alcohols, preferably dihydric to octahydric alcohols having a molecular weight of from 60 to 350, or mixtures thereof are incorporated in an effective amount, advantageously in an amount of from 0.01 to 5% by weight, based on the weight of crude MDI, into the reaction mixture after the end of the phosgenation, the phosgene and the inert organic solvent are then separated off, from 0 to 5% by weight, based on the weight of crude MDI, of one or more phenol-based antioxidants and/or aryl phosphite are added to the reaction product, and the reaction mixture is subjected to a thermal treatment.

Abstract: Mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (crude MDI) of reduced iodine color number are prepared by reacting the corresponding mixtures of diphenylmethanediamines and polyphenylpolymethylenepolyamines with phosgene in the presence of at least one inert organic solvent at elevated temperature, at least one monohydric or polyhydric polyoxyalkylene alcohol, preferably having a functionality of from 2 to 3, and advantageously having a hydroxyl number of from 20 to 1800, or mixtures thereof in an effective amount, expediently in an amount of from 0.1 to 10% by weight, based on the weight of the crude MDI, being introduced into the reaction mixture when the phosgenation is complete, the phosgene and the inert organic solvent then being removed, up to 5% by weight, based on the weight of crude MDI, of at least one phenol-based antioxidant and/or aryl phosphite being added, if desired to the reaction product, and the reaction mixture being heated.

Abstract: The present invention is directed to a process of preparing isocyanate-substituted isophthaloyl chloride by heating a mixture of amino-substituted isophthalic acid, catalyst, phosgene and halogenated solvent under autogeneous pressure.

Abstract: A fractionation process of a methylene bridged polyphenylene polyisocyanate mixture obtained by phosgenating condensation product of aniline and formaldehyde is disclosed.In order to apply the above mixture to a variety of uses, the process separates the mixture into fractions by giving primary attention to the content of 4,4'-and 2,4'-isomer of diphenylmethane diisocyanate and at the same time reduces the content of impurities having acidity and hydrolyzable chlorine.

Abstract: This invention is an industrially efficient and improved process for the preparation of aliphatic polyisocyanates by using esters as the solvent for converting aliphatic polyamines to isocyanates.

Abstract: Disclosed herein is an improved process for the preparation of polymethylene polyphenyl polyisocyanate by reacting phosgene with a corresponding polyamine, followed by removing residual phosgene from the reaction mixture, the improvement comprising removing the residual phosgene by contacting the reaction mixture which is maintained at 150 degrees Centigrade or lower, with an inert solvent vapor stream at a temperature which is sufficient to effect a substantially complete removal of the residual phosgene.

Abstract: The present invention relates to a process for the continuous preparation of organic mono- or polyisocyanates by the reaction of the mono- or polyamines corresponding to the mono- or polyisocyanates with phosgene dissolved in an organic solvent. The phosgene solution and the amine component, optionally also in the form of a solution, are brought together inside a nozzle (1) by subjecting the stream of one component to a constriction (3) and supplying the other component into this constriction (3) from the side as partial streams through several apertures (5).

Abstract: Substituted 3,5-dichloro-2,4-difluoro-benzenes of the formula ##STR1## in which R represents nitro, amino (including the corresponding ammonium salts) or isocyanato, which can be prepared from 2,3,4,5-tetrachloro-nitrobenzene by means of the reaction, carried out initially, with alkali metal fluorides at elevated temperature in a polar, aprotic solvent, starting from a crude 2,3,4,5-tetrachloro-nitrobenzene containing 2,3,5,6-tetrachloro-nitrobenzene and/or 2,3,4,6-tetrachloro-nitrobenzene, and substituted 3,5-dichloro-2,4-difluoro-benzene being isolated from the reaction mixture at the nitro stage or, after reduction of the nitro group, at the amino stage or, after reduction and phosgenation of the amino group, at the isocyanate stage.

Abstract: The present invention is directed to a novel process for preparing isothiocyanate functionalized chelates by reacting amino functionalized chelates with thiophosgene.