Abstract: An object of the present invention is to provide an isocyanate production process, which is free of the various problems found in the prior art, and which uses a composition containing a carbamic acid ester and an aromatic hydroxy compound when producing isocyanate without using phosgene, as well as a carbamic acid ester composition for transferring or storing carbamic acid ester. The present invention discloses an isocyanate production process including specific steps and using a composition containing a carbamic acid ester and an aromatic hydroxy compound, as well as a composition for transfer or storage of carbamic acid ester comprising the carbamic acid ester and the specific aromatic hydroxy compound.

Abstract: The invention provides a multistage process for continuously preparing organic polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic polyamines with carbonic acid derivatives and alcohols into monomeric polyurethanes of low molecular mass, and the dissociation of said polyurethanes. The invention further provides an associated preparation process in which at certain reaction stages the polyisocyanates prepared and unutilizable residues are removed and reusable by-products and intermediates are recycled to preliminary stages.

Abstract: The invention relates to a multi-stage process for the continuous, phosgene-free preparation of (cyclo)aliphatic diisocyanates that comprises the conversion of (cyclo)aliphatic diamines into the corresponding (cyclo)alkylene biscarbamates and the thermal cleaving of the latter into the (cyclo)alkylene diisocyanates and alcohol. The urea used in accordance with the invention and also the urea employed for the preparation of urea equivalents (e.g. alkyl carbonates, alkyl carbamates) as a possible precursor for the synthesis of the (cyclo)aliphatic biscarbamates is unconditioned.

Abstract: A method for producing tolylene diisocyanate includes: mixing a first diaminotoluene containing 2,4-diaminotoluene and 2,6-diaminotoluene at a first isomer ratio and a second diaminotoluene containing 2,4-diaminotoluene and/or 2,6-diaminotoluene at a second isomer ratio that is different from the first isomer ratio so as to prepare mixed diaminotoluene; producing tolylene dicarbamate by reaction of the mixed diaminotoluene, urea and/or N-unsubstituted carbamic acid ester and alcohol; and thermally decomposing the tolylene dicarbamate.

Abstract: The invention provides a multistage process for continuously preparing organic, distillable polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to low molecular mass monomeric polyurethanes, and thermally cleaving said polyurethanes, in which at defined reaction stages the polyisocyanates prepared and unusable residues are separated off, and reusable by products and intermediates are recycled to upstream stages.

Abstract: Low chlorine, multi-staged method for producing cycloaliphatic diisocyanates. The invention relates to a multi-staged method for the continuous low-chlorine production of cycloaliphatic diisocyanates, comprising the synthesis of diaminodipheynl alkanes, the hydration thereof into the corresponding cycloaliphatic diamines and the subsequent conversion of cycloaliphatic diamines to the corresponding cycloalkylene biscarbamates and the thermal cleaving of the latter into the cycloaliphatic diisocyanates and alcohol.

Abstract: The invention provides a multistage process for continuously preparing organic polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic polyamines with carbonic acid derivatives and alcohols into monomeric polyurethanes of low molecular mass, and the dissociation of said polyurethanes. The invention further provides an associated preparation process in which at certain reaction stages the polyisocyanates prepared and unutilizable residues are removed and reusable by-products and intermediates are recycled to preliminary stages.

Abstract: The invention relates to a multistage process for the continuous preparation of organic, distillable polyisocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic polyamines with carbonic acid derivatives and alcohols to form low molecular weight monomeric polyurethanes and thermal dissociation of the latter, in which the polyisocyanates produced and unusable residues are separated off at particular stages of the reaction and reusable by-products and intermediates are recirculated to preceding stages.

Abstract: The invention relates to a multistage process for the continuous preparation of organic, distillable isocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic amines with urea and alcohols to liberate ammonia and form low molecular weight monomeric urethanes and thermal dissociation of the latter, in which by-products formed are at least partly utilized.

Abstract: An object of the present invention is to provide an isocyanate production process, which is free of the various problems found in the prior art, and which uses a composition containing a carbamic acid ester and an aromatic hydroxy compound when producing isocyanate without using phosgene, as well as a carbamic acid ester composition for transferring or storing carbamic acid ester. The present invention discloses an isocyanate production process including specific steps and using a composition containing a carbamic acid ester and an aromatic hydroxy compound, as well as a composition for transfer or storage of carbamic acid ester comprising the carbamic acid ester and the specific aromatic hydroxy compound.

Abstract: The invention relates to a multi-stage process for the continuous, phosgene-free preparation of (cyclo)aliphatic diisocyanates that comprises the conversion of (cyclo)aliphatic diamines into the corresponding (cyclo)alkylene biscarbamates and the thermal cleaving of the latter into the (cyclo)alkylene diisocyanates and alcohol. The urea used in accordance with the invention and also the urea employed for the preparation of urea equivalents (e.g. alkyl carbonates, alkyl carbamates) as a possible precursor for the synthesis of the (cyclo)aliphatic biscarbamates is unconditioned.

Abstract: The invention relates to a multistage process for the continuous preparation of organic, distillable isocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic amines with urea and alcohols to liberate ammonia and form low molecular weight monomeric urethanes and thermal dissociation of the latter, in which by-products formed are at least partly utilized.

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 provides a multistage process for continuously preparing organic, distillable polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to low molecular mass monomeric polyurethanes, and thermally cleaving said polyurethanes, in which at defined reaction stages the polyisocyanates prepared and unusable residues are separated off, and reusable by products and intermediates are recycled to upstream stages.

Abstract: The present invention relates to a process for preparing arylsulfonyl isocyanates by reacting an arylsulfonamide with phosgene in the presence of a catalytically effective amount of an alkyl isocyanate.

Abstract: The present invention relates to a process for preparing a low boiling monoisocyanate having a boiling point of between 70 and 320° C. at standard pressure by reacting A) a high boiling isocyanate compound having a boiling point of at least 180° C. at standard pressure and an HC content of at least 50 ppm with B) a monoamine having a primary amino group, at a maximum reaction temperature of 180° C. and a molar ratio of isocyanate groups to amino groups of at least 4:1 to form a compound containing a biuret/urea group, simultaneously thermally decomposing this compound in situ to form a monoisocyanate corresponding to monoamine B) and removing the monoisocyanate by distillation, optionally under vacuum.

Abstract: Described are diester amine adducts of formula (1) wherein R1, R2, R3, R4 are each independently of one another C4-C22alkyl; C2-C22alkenyl; or C5-C7cycloalkyl; X1 and X2 are each independently of the other hydrogen, C1-C4alkyl; C2-C4hydroxyalkyl or C2-C4hydroxyhaloalkyl; Y is a radical of formula (1b); A1 is C2-C3alkylene or 2-hydroxy-n-propylene; X3 is hydrogen; C1-C4alkyl, C2-C4hydroxyalkyl; or C2-C4hydroxyhaloalkyl; (A) is an asymmetrical carbon atom in the R- or S-configuration, wherein, if C1=R, C2=R; C1=S, C2=S; and C1=R; C2=S; m1 is 1 or 2; and n is an integer from 1 to 4; p is 0 or 1; which adducts may be in the form of free bases or ammonium salts. Said compounds are precursors of compounds having good complex-forming properties and are thus able to effectively bind heavy metal ions such as iron, zinc, magnesium or copper ions and to prevent metal-initiated oxidations after enzymatic or chemical cleavage.

Abstract: A reduced-color isocyanurate-functional polyisocyanate is prepared by partially trimerizing 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI) having a low total chlorine content of less than 80 mg/kg in the presence of a catalyst, thereby resulting in a product isocyanurate-functional polyisocyanate having a content of free NCO groups of between 10 and 22% and a residual monomer content of less than 0.7%.

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: 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 process for the preparation of isocyanic acid, characterized in that N,N-disubstituted ureas are decomposed at elevated temperature to a secondary amine of lower volatility and to isocyanic acid, which is drawn off at the top.

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 trisubstituted ureas is disclosed. A nitroarene is reacted with carbon monoxide and a secondary amine in the presence of a Group VIII transition metal catalyst and optionally one or more promoters selected from primary amines, halide ion-containing compounds, and chelating phosphorus and nitrogen compounds.

Abstract: The present invention relates to polyisocyanates which contain ester groups and havea) a content of aliphatically bound isocyanate groups of 18 to 33% by weight,b) an average NCO functionality of 4.1 to 10, preferably from 4.5 to 10, andc) a viscosity of 200 to 2,5000 mPa.s at 22.degree. C.The present invention also relates to preferred polyisocyanates which contain ester groups and havea) a content of aliphatically bound isocyanate groups of 20 to 33% by weight,b) an average NCO functionality of 5 to 8 andc) a viscosity of 500 to 1,000 mPa.s at 22.degree. C.The present invention further relates to a process for the preparation of these preferred polyisocyanates by reacting isocyanatocarboxylic acid chlorides with O-silylated, polyhydric alcohols at a temperature of about 50.degree. to 150.degree. C. Finally, the present invention relates to the use of the polyisocyanates as the isocyanate component for two-component polyurethane coating compositions.

Abstract: A circulation process for the production of (cyclo)aliphatic diisocyanates, in which the biscarbamate is produced from diamines, by-products from the thermal cracking, urea, and alcohol in the presence of N-unsubstituted carbamates and dialkyl carbonates, and with separation of NH.sub.3 ; the subsequent cracking of the biscarbamate is carried out in the liquid phase without solvent; the diisocyanate and alcohol are condensed; the diisocyanate is subjected to a purifying distillation; and a portion of the cracking reaction mixture is discharged with the by-products formed and recycled to the biscarbamate production step after prior reaction with the crude alcohol formed, effectively utilizes the by-products formed in the cracking step and is an industrially practical and economical process.

Abstract: The invention provides an improved method for obtaining optically active amines, carbamates, and isocyanates by thermal fragmentation of optically active ureas through refluxing the ureas in C.sub.3 -C.sub.7 alcohol solution with or without catalytic amounts of alkali metal.

Abstract: An improved process is provided for the preparation of methylene diphenylene diisocyanates (MDI) and polymethylene polyphenylene poly (isocyanates) (PMDI) by the thermal decomposition of a methylene diphenylene bis (dialkylurea) or a polymethylene polyphenylene poly (alkylurea) in a solvent in the presence of an organic sulfonic acid or sulfonated aromatic ion exchange resin as a promoter for conversion of the urea groups to the corresponding isocyanate.

Abstract: An improved process is provided for the preparation of aromatic mono- and poly-isocyanates by the thermal decomposition of an aromatic bis dialkyl urea in solvent in the presence of an organic sulfonic acid or sulfonated aromatic ion exchange resin as a promoter for conversion of the urea groups to isocyanates.

Abstract: A process is disclosed for the preparation of aralkyl mono- and diurethanes or ureas by carbamylmethylation, or acid-catalyzed addition at a temperature of 40.degree. C. to about 100.degree. C. of formaldehyde and esters of carbamic acid to aromatic hydrocarbons. Aralkyl carbamates and ureas formed by this process can be cracked directly to produce aralkyl diisocyanates, or hydrogenated and then cracked to produce aliphatic diisocyanates, or reacted directly with polyols to produce polyurethanes by functioning as blocked isocyanates.

Abstract: An improved process is provided for the preparation of methylene diphenylene diisocyanates (MDI) and polymethylene polyphenylene poly (diisocyanates) by the thermal decomposition of a methylene diphenylene bis (dialkylurea) or a polymethylene polyphenylene poly (dialkylurea) in a solvent in the presence of a tertiary amine hydrohalide, such as pyridine hydrochloride, as a promoter for conversion of the urea groups to the corresponding isocyanate.

Abstract: An improved process is provided for the preparation of aromatic mono- and poly- isocyanates by the thermal decomposition of an aromatic bis dialkyl urea in solvent in the presence of a tertiary amine hydrohalide, such as pyridine hydrochloride, as a promoter for conversion of the urea groups to isocyanates.

Abstract: Hexamethylene 1,6-diisocyanate and/or isomeric aliphatic diisocyanates where alkylene is of 6 carbon atoms, preferably 2-methylpentamethylene 1,5-diisocyanate and/or 2-ethyltetramethylene 1,4-diisocyanate, are prepared by a process wherein the corresponding dialkylurethanes are vaporized, without decomposition, at from 220.degree. to 300.degree. C., advantageously under reduced pressure, the dialkylurethane vapors are subjected to thermal cleavage under reduced pressure, preferably from 0.1 to 200 mbar, and at above 300.degree. C., preferably from 310.degree. to 480.degree. C. The cleavage products are fractionally condensed with the product obtained in the first condensation stage consisting predominantly of the diisocyanates, while that obtained in the second condensation stage is the alcohol.

Abstract: This invention discloses a non-phosgene process for the preparation of 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate by the reaction of the precursor diamine with urea and an aliphatic alcohol in the presence of a dialkyl carbonate and an alkyl carbonate. The intermediate diurethane is separated from starting materials and by-products and thermally cleaved to alcohol and diisocyanate which are separated by fractional condensation of the products from the vapor state. This process gives high yields of the desired diisocyanate and lends itself particularly to continuous processing.