Abstract: Process for the synthesis of non cyclic carbamate derivatives from amine compounds, alcohols and CO2 in the presence of ionic liquids and optionally in the presence of a base.

Abstract: An object of the present invention is to provide a process allowing long-term, stable production of isocyanates at a high yield without the various problems found in the prior art during production of isocyanates without using phosgene. The present invention discloses a process for producing an isocyanate by subjecting a carbamic acid ester to a decomposition reaction in the presence of a compound having an active proton and a carbonic acid derivative.

Abstract: An object of the present invention is to provide a process that enables isocyanates to be stably produced over a long period of time at high yield without encountering various problems as found in the prior art when producing isocyanates without using phosgene.

Abstract: Urethanes are prepared by oxidative carbonylation of at least one amino compound in the presence of carbon monoxide, oxygen and organic, at least one hydroxyl-group-carrying compound. The carbonylation is carried out in the absence of halogen-containing promoters. The carbonylation is also carried out in the presence of a metal complex catalyst which contains neutral bidentate N-chelate ligands of the (N˜N) type, two monoanionic N,O-chelate ligands of the general type (N˜O)? or tetradentate dianionic chelate ligands (O˜N˜N˜O)2?.

Abstract: Cycloaliphatic diisocyanates can be prepared continuously and phosgene-free by reacting at least one cycloaliphatic diamine with at least one carbonic acid derivative and at least one alcohol to give a cycloaliphatic diurethane; freeing the cycloaliphatic diurethane of a low boiler, a medium boiler and mixtures thereof; thermally cleaving the cycloaliphatic diurethane in a cleavage apparatus to give a cycloaliphatic diisocyanate and a cleavage residue; continuously discharging a portion of the cleavage residue from the cleavage apparatus; removing the high boiler components from the discharge to obtain a purified discharge; reurethanizing the purified discharge with alcohol to obtain a reurethanized discharge; and recycling the reurethanized discharge into the process.

Abstract: The invention relates to a multistage process for continuous and phosgene-free preparation of cycloaliphatic diisocyanates.

Abstract: A multistage process for continuous and phosgene-free preparation of cycloaliphatic diisocyanates.

Abstract: A process for the preparation of isocyanates from carbamic esters.

Abstract: Integrated process for the preparation of aromatic isocyanates comprising: the reaction between an aromatic amine and an organiccarbonate in the presence of a catalyst selected from organic and inorganic salts of a metal selected from Zn, Sn, Pb, Cu; the removal of the catalyst; the passivation of the quantity of residual metal in the urethane formed in step a); the removal of the organic solvent and its optional recycling to step a) of the reaction; the evaporation of the aromatic urethane with partial pyrolysis; the complete pyrolysis of the urethane in gas phase; the recovery of the isocyanate.

Abstract: A phosgene-free process for producing organic isocyanates reacts an organic fomamide with a diorganocarbonate and thermolyzing the reaction product to obtain the corresponding organic isocyanate. Byproducts may be cycled back to the reaction or recycled to produce additional starting materials. The process product organic isocyanates in high yield.

Abstract: The invention relates to a method for synthesis of aliphatic isocyanates from aromatic isocyanates in substantially 3 stages. In particular, the invention relates to a method for synthesis of bis{4-isocyanatocyclohexyl}methane (H12MDI) from bis{4-isocyanatophenyl}methane (MDI). More especially, the invention relates to a method for synthesis of H12MDI with a trans-trans isomer content of <30%, preferably of <20%, particularly preferably of 5 to 15%.

Abstract: The procedure consists of the catalytic thermal decomposition of a carbamate in the presence of natural or synthetic carbamates as catalysts. Isocyanates with high yields and high reaction speeds are formed selectively.

Abstract: Integrated process for the preparation of aromatic isocyanates comprising: the reaction between an aromatic amine and an organiccarbonate in the presence of a catalyst selected from organic and inorganic salts of a metal selected from Zn, Sn, Pb, Cu; the removal of the catalyst; the passivation of the quantity of residual metal in the urethane formed in step a); the removal of the organic solvent and its optional recycling to step a) of the reaction; the evaporation of the aromatic urethane with partial pyrolysis; the complete pyrolysis of the urethane in gas phase; the recovery of the isocyanate.

Abstract: A method for producing carbamates that enables carbamates to be produced at low costs, with high selectivity and high yield, and in a simple manner, and a method for producing isocyanates that enables isocyanates industrially used to be produced by using the carbamates obtained by the carbamates producing method. Nonaromatic amine selected from the group consisting of aliphatic amine, alicyclic amine, and aralkyl amine is allowed to react with alkylaryl carbonate to thereby produce carbamates. Also, the carbamates thus obtained are thermally decomposed to thereby produce isocyanates. When carbamates are produced in this method, alkyl carbamates can be obtained with high selectivity and at high yield by using simple equipment. Also, when isocyanates are produced in this method, polyisocyanates used industrially as the raw material of polyurethane can be produced in a simple manner and with efficiency.

Abstract: Process for the preparation of organic polyisocyanates by decomposing the corresponding organic polycarbamates into organic polyisocyanates and alcohols, characterised in that the alcohol and at least part of either the diisocyanates or the monoisocyanatomonocarbamates, or both, formed upon decomposition of the said polycarbamates is removed during the decomposition.

Abstract: The procedure consists of the catalytic thermal decomposition of a carbamate in the presence of natural or synthetic carbamates as catalysts. Isocyanates with high yields and high reaction speeds are formed selectively.

Abstract: The invention concerns a process for the enzymatic preparation of protected di- and oligopeptides and the separation of the protective groups used. The process according to the invention enables peptides to be synthesized simply and economically and the protective group to be separated carefully. The process comprises three reaction steps: 1. Preparation of N-carbamoyl amino acid or N-carbamoyl amino acid derivatives; 2. Formation of the peptide bond between the carbamoyl-protected electrophile and nucelophile; and 3. Separation of the carbamoyl-protective group.

Abstract: A process for the preparation of ethylenically unsaturated isocyanates is described, which process comprises silylating an appropriate ethylenically unsaturated urethane precursor at the urethane nitrogen and converting the resulting unsaturated N-silyl-urethane by means of thermolysis at elevated temperature into the desired isocyanate. The unsaturated isocyanates obtainable according to the process are suitable, for example, as monomers or comonomers in the preparation of polymerisates or copolymerisates.

Abstract: The present invention relates to ethylenically unsaturated polyurethanes which are substantially free from isocyanate groups and havea) a content of .beta.,.gamma.-ethylenically unsaturated ether groups (calculated as C.dbd.C, MW 24) incorporated through allophanate groups of 0.5 to 10% by weight,b) an allophanate group content (calculated as N.sub.2 C.sub.2 HO.sub.3, MW 101) of 1 to 20% by weight andc) a total content of ethylenically unsaturated groups of (calculated as C.dbd.C, MW 24) of 1 to 15% by weight.The present invention also relates to ethylenically unsaturated polyisocyanates which contain allophanate groups and havei) an NCO content of 5 to 25% by weight,ii) a content of .beta.,.gamma.-ethylenically unsaturated ether groups (calculated as C.dbd.C, MW 24) incorporated through allophanate groups of 0.5 to 15% by weight andiii) an allophanate group content (calculated as N.sub.2 C.sub.2 HO.sub.3, MW 101) of 1 to 30%.

Abstract: An aliphatic diisocyanate compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethane compound; and, within 48 hours after the completion of the preparation of the urethane compound, thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling-point solvent.

Abstract: In the decomposition of a polymer containing a urethane linkage and/or urea linkage in the presence of a decomposing agent, the amount of evolved carbon dioxide is measured and the decomposition reaction is conducted until a total amount of evolved carbon dioxide reaches a specified value to obtain a liquid decomposition product. According to the present invention, a decomposition product having constant quality can be obtained in a simple manner.

Abstract: Inert, thermally stable high-boiling solvents which have a defined boiling point or which boil over a narrow range are used as heat exchange media during thermal cracking of carbamic acid esters (urethane cracking).

Abstract: An aliphatic diisocyante compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethene compound; and, within 48 hours after the completion of the preparation of the urethane compound, thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling-point solvent.

Abstract: A diisocyanate compound substantially free from chlorine is prepared by the following consecutive steps (1), (2) and (3):(1) preparing dimethyl carbonate by a method selected from:(a) a method wherein carbon monoxide and oxygen are reacted with methanol,(b) a method wherein propylene oxide is reacted with carbon dioxide to prepare propylene carbonate, and then, the propylene carbonate is reacted with methanol, and(c) a method wherein a nitrous acid ester is catalytically reacted with carbon monoxide;(2) reacting the dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to prepare a corresponding urethane compound; and(3) thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling point solvent.

Abstract: This present invention relates to a process for thermally cracking carbamic acid esters into the corresponding isocyanate and hydroxyl compounds in the liquid phase, wherein the reaction proceeds as a reactive rectification in the stripping zone of a column and in an inert, high-boiling solvent, which acts as a buffer to keep the reaction away from the evaporator region of the column.

Abstract: The present invention relates to a process for preparing polyisocyanates containing allophanate groups by reacting compounds a), whichi) contain urethane groups, but which are substantially free of hydroxyl groups and isocyanate groups,ii) have an average of at least two urethane groups per molecule,iii) are prepared by reacting organic isocyanates a1) with organic hydroxyl compounds a2) andiv) have an average molecular weight of at most 2,500,with excess quantities, based on the urethane groups, of distillable organic polyisocyanates b) to form polyisocyanates containing allophanate groups and subsequently removing by distillation the unreacted excess of component b) to a residual content of less than 0.5 wt. %, provided that polyisocyanates a1) and polyisocyanates b) are different.The present invention also relates to the products obtained from this process and to their use as binders or binder components in coating compositions.

Abstract: Novel aromatic diisocyanate and a method of producing the same. The method comprises reacting a diamine compound with a chloroformate to produce an urethane intermediate, and then reacting the urethane intermediate with a halogenated organosilicon compound or a halogenated organoboron compound, using an organic solvent capable of dissolving both the diamine compound and the urethane intermediate. This method enables to produce the aromatic diisocyanate by one-pot. The aromatic diisocyanate has excellent various properties such as high heat resistance and chemical resistance.

Abstract: Allophanate-modified 1,3-phenylene diisocyanates or 1,1-biphenyl diisocyanates or 1,1'-oxy-bis-(isocyanato benzenes) which are storage stable liquid at 25.degree. C. are made by reacting the diisocyanate and a mono-alcohol to form an isocyanate containing urethane groups. The urethane groups in the diisocyanate are then converted to allophanate groups. The resultant product which has an isocyanate group content of from about 10 to about 40% may be further reacted with isocyanate-reactive compounds to produce an allophanate-modified diisocyanate prepolymer containing urethane or urea groups having an isocyanate group content of from about 5 to about 40.0%. The liquid, storage-stable, allophanate-modified diisocyanates produced by these processes are particularly useful in the production of elastomers and flexible foams.

Abstract: Low-boiling by-products are removed from diurethanes prepared by a phosgene-free process by carrier vapor distillation using alcohol vapor, preferably the vapor of the basic alcohol found in the diurethane, as the carrier vapor. The diurethanes freed of low-boiling by-products in this manner may be thermally decomposed to produce diisocyanates.

Abstract: Low-viscosity (cyclo)-aliphatic polyamines containing urea groups and having more than two amino groups may be prepared by reacting (cyclo)aliphatic diamines with polyisocyanates containing isocyanurate groups or biuret groups. Such polyamines are useful as components in PUR reaction finishes and coating and adhesive compositions.

Abstract: In a reactor for the thermal cleavage of mono- and polyfunctional carbamic esters into the corresponding isocyanates and the hydroxyl component in the liquid phase, the geometry of the reactor, defined by the degassing area in relation to the volume and the arrangement of the heating surfaces, permits cleavage in a two-phase mixture which has a volumetric gas content of more than 50%.

Abstract: Provided is a process for producing isocyanates from carbamic acid esters which comprises thermally decomposing carbamic acid esters in the presence of a catalyst containing at least one compound selected from the group consisting of organic sulfonic acids and alkaline metal salts of organic sulfonic acids. Thereby, a high thermal decomposition rate can be provided and isocyanate can be obtained in a high yield.

Abstract: Urethanes are converted to isocyanates by reaction with a chloro-, bromo- or iodo-borane compound and a tertiary amine in a nonpolar solvent. With the preferred borane compound, chlorocatecholborane, the reaction goes speedily and under gentle conditions to give the isocyanate in good yield. Also formed is a borate which can be readily converted to the borane compound, for reuse.

Abstract: Polycarbamates of a polyisocyanate and secondary alcohols are disclosed. These carbamates are characterized in being readily pyrolyzed to form the corresponding polyisocyanate and alcohol with low formation of tars and other by-products. Thus, these polycarbamates can be pyrolyzed under relatively mild conditions, and in the absence of solvent and catalyst.

Abstract: A process for preparing isocyanates comprising contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and a base selected from the group consisting of a phosphazene compound, an organic, nitrogenous base and mixtures thereof, wherein the organic, nitrogenous base selected from the group consisting of guanidine compounds, amidine compounds, tertiary amines and mixtures thereof to produce the corresponding ammonium carbamate salt, reacting the ammonium carbamate salt with an anhydride dehydrating agent to produce a product stream comprising the corresponding isocyanate, the aprotic organic solvent and the base salt derived from the anhydride, separating the base salt from the product stream, recovering and recycling the base, and regenerating and recycling the anhydride dehydrating agent.

Abstract: The preparation of organic isocyanates of formula by the thermal decomposition of the corresponding carbamates in an inert solvent, is improved by thermally treating the dissolved carbamate in separate steps, decomposing the carbamate to isocyanate and alcohol, with intermediate steps of removing the alcohol with an inert stripping agent, recovering a solution rich in isocyanate.

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: A multistep process for the continuous preparation of organic polyisocyanates, preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to give monomeric polyurethanes and pyrolyzing the latter involves separating the resultant polyisocyanates and worthless residues in certain reaction steps and recycling the reusable by-products into earlier steps.

Abstract: A continuous multistage process for the preparation of (cyclo)aliphatic diisocyanates comprising a) condensing urea with a (cyclo)aliphatic diamine in the presence of an alcohol solvent to make a (cyclo)alkylenebisurea in a distillation reactor; b) reacting the crude (cyclo)alkylenebisurea with alcohol in a pressurized distillation reactor to make (cyclo)biscarbamate; c) removing the ammonia formed in the pressurized distillation reactor; d) cleaving the (cyclo)biscarbamate in the presence of a catalyst in a combined cleavage and rectifying column to make crude (cyclo)alkylene diisocyanate; e) reacting a diverted portion of the cleavage products with the alcohol to form a recycling mixture; f) and distilling the crude (cyclo)alkylene diisocyanate formed in step d.

Abstract: A process for preparing isocyanates comprising (a) contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and a base selected from the group consisting of a phosphazene compound, an organic, nitrogenous base and mixtures thereof, wherein the organic, nitrogenous base selected from the group consisting of guanidine compounds, amidine compounds, tertiary amines, pyridine and mixtures thereof to produce the corresponding ammonium carbamate salt, and (b) reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent to produce the corresponding isocyanate.

Abstract: Novel bicyclic alkyl dicarbamates are prepared from norbornadiene and other simple starting materials, and these are subsequently thermally cracked to novel diisocyanate norbornyl derivatives, which are, among others, useful for crosslinking active hydrogen compounds.

Abstract: A method for preparing isocyanates by the thermal decomposition of carbamates in the presence of a sintered oxide as catalyst under gaseous phase condition. The sintered oxide is composed of at least one element selected from the group consisting of boron, aluminum, silicon, tin, lead, antimony, zinc, yttrium, lanthanum, titanium, zirconium, niobium, tungsten, and iron. The sintered oxide may be composed of at least one element selected from the group consisting of phosphorus, alkali metal element, and alkaline earth metal element.

Abstract: A process for preparing isocyanates comprising (a) contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and a phosphazene compound or a mixture of a phosphazene compound and an organic, nitrogenous base selected from the group consisting of guanidine compounds, amidine compounds, tertiary amines, pyridine and mixtures thereof to produce the corresponding ammonium carbamate salt, and (b) reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent to produce the corresponding isocyanate. A second embodiment comprises recovering the ammonium carbamate salt of step (a) prior to reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent in the presence of an aprotic organic solvent and a phosphazene compound or a mixture of a phosphazene compound and an organic, nitrogenous base selected from the group consisting of guanidine compounds, amidine compounds, tertiary amines, pyridine and mixtures thereof.

Abstract: A process for the continuous catalyst-free production of polyisocyanates by thermal decomposition of the N-substituted carbamic acid esters corresponding to the polyisocyanates, in which the carbamic acid esters to be decomposed, in the form of a 5 to 90% by weight solution in an inert high-boiling solvent, are heated to a temperature of 100.degree. to 400.degree. C. and are subsequently introduced with expansion as a sidestream into a distillation column (4), in the sump of which a pressure of 0.001 to 5 bar and a temperature of 150.degree. to 400.degree. C. are maintained so that the high boiler is kept boiling in the sump, and the decomposition products are simultaneously condensed continuously and selectively at the head of the distillation column. The high boiler, which optionally contains impurities, is continuously removed via the sump outlet in a quantity substantially corresponding to the quantity of high boiler introduced into the column as solvent for the carbamic acid ester.

Abstract: A process for preparing an isocyanate having at least two --N.dbd.C.dbd.O groups is provided which comprises preparing a substituted aromatic amine having at least two --NH.sub.2 groups, recovering the substituted aromatic amine having at least two --NH.sub.2 groups, and preparing an isocyanate from the substituted aromatic amine having at least two --NH.sub.2 groups by (1) contacting the substituted aromatic amine with CO.sub.2 under conditions sufficient to produce the corresponding ammonium carbamate salt, and reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent under conditions sufficient to produce the corresponding isocyanate, or (2) contacting the substituted aromatic amine with CO.sub.

Abstract: A process for preparing nitrogen-containing compounds which comprises contacting a carboxylated N-monosubstituted nitrogen-containing compound or a carboxylated N,N-disubstituted nitrogen-containing compound with a mixed metal oxide catalyst under conditions effective to produce the nitrogen-containing compound.

Abstract: Organic mono- or di-isocyanates are prepared by the decomposition of the corresponding urethanes, by means of a continuous process in which:(a) an urethane flow is continuously fed to a decomposition reactor containing a liquid mixture, composed of a high boiling inert organic solvent, of an unaltered urethane and isocyanate, kept at the boiling conditions of the solvent, at a temperature suitable to decompose the urethane and evaporate the alcohol which is the co-product of the reaction;(b) the liquid mixture is continuously withdrawn from the reactor in (a) and is fed to a flash equipment, at an operating temperature lower than the decomposition temperature of the urethane, where the isocyanate is partially evaporated and the residuous liquid mixture is recycled to the reactor in (a); and(c) the steam flow generated in (b) is distilled to separate the isocyanate in pure or substantially pure form.

Abstract: Xylylene diisocyanate is produced in higher space-time yield with higher selectivity by thermal decomposition of xylylene dicarbamate as an urethane compound, i.e. by subjecting the urethane compound to reactive distillation with a thermal decomposition catalyst of at least one of metals selected from antimony and tin or their compounds in the presence of an inert solvent having a higher boiling point than that of the resulting xylylene diisocyanate under reduced pressure of 1 to 500 mmHg and at 150.degree. to 350.degree. C. and then subjecting the resulting reaction products as distillates to partial condensation outside the reactive distillation system, thereby separately recovering the resulting alcohol and xylylene diisocyanate.

Abstract: A process for preparing isocyanates comprising (a) contacting carbon dioxide and a primary amine in the presence of an aprotic organic solvent and an organic, nitrogenous base to produce the corresponding ammonium carbamate salt, and (b) reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent to produce the corresponding isocyanate. A second embodiment comprises recovering the ammonium carbamate salt of step (a) prior to reacting the ammonium carbamate salt with an electrophilic or oxophilic dehydrating agent in the presence of an aprotic organic solvent and an organic, nitrogenous base.

Abstract: There is disclosed a process for producing an isocyanate compound from a formamide compound or an amine compound which comprises (a) the first reaction step of reacting a formamide compound with dimethyl carbonate in the presence of an alkali catalyst, or reacting methyl formate and an amine compound with dimethyl carbonate in the presence of an alkali catalyst, to produce a corresponding urethane compound, and (b) the second reaction step of thermally decomposing the urethane compound at a temperature of 150.degree.-350.degree. C. and separately recovering the methanol and the corresponding isocyanate compound thus formed.