Abstract: The invention relates to polyphenyl polymethylene polyisocyanates having an NCO number of at least 29% comprising less than 2% by weight ureas, less than 8% by weight carbodiimides or uretonimines and less than 1000 ppm organic chlorine compounds. The polyphenyl polymethylene polyisocyanates can be prepared according to the invention by reacting (i) polyphenyl polymethylene polyamines with organic carbonates to give the corresponding polyphenyl polymethylene polycarbamates, (ii) by thermally cleaving the polyphenyl polymethylene polycarbamates to give the polyphenyl polymethylene polyisocyanates, wherein, prior to the thermal cleavage, the free amino groups or urea groups present in the carhamate crude mixture comprising the polyphenyl polymethylene polycarbamates are reacted with a derivatizing reagent to give amide groups or urethane groups.

Abstract: Process for manufacturing a crystalline alkali metal salt of the general formula (I) [R1—CH(COO)—N(CH2—COO)2]M13 (I) wherein M1 is selected from alkali metal cations, same or different, R1 is selected from C1-C4-alkyl and CH2CH2COOM1, comprising the step of (b) crystallizing said alkali metal salt from an aqueous solution containing in the range of from 5 to 30% by weight of alkali metal hydroxide, referring to said aqueous solution.

Abstract: Process for manufacturing a crystalline alkali metal salt of the general formula (I) [R1—CH(COO)—N(CH2—COO)2]M13 (I) wherein M1 is selected from alkali metal cations, same or different, R1 is selected from C1-C4-alkyl and CH2CH2COOM1, comprising the step of (b) crystallizing said alkali metal salt from an aqueous solution containing in the range of from 5 to 30% by weight of alkali metal hydroxide, referring to said aqueous solution.

Abstract: The invention relates to polyphenyl polymethylene polyisocyanates having an NCO number of at least 29% comprising less than 2% by weight ureas, less than 8% by weight carbodiimides or uretonimines and less than 1000 ppm organic chlorine compounds. The polyphenyl polymethylene polyisocyanates can be prepared according to the invention by reacting (i) polyphenyl polymethylene polyamines with organic carbonates to give the corresponding polyphenyl polymethylene polycarbamates, (ii) by thermally cleaving the polyphenyl polymethylene polycarbamates to give the polyphenyl polymethylene polyisocyanates, wherein, prior to the thermal cleavage, the free amino groups or urea groups present in the carhamate crude mixture comprising the polyphenyl polymethylene polycarbamates are reacted with a derivatizing reagent to give amide groups or urethane groups.

Abstract: A process for coproducing di- and/or polyisocyanates and glycols, comprising process stages A, B, C and E for preparing glycols and process stages A, C, D, E, F and G for preparing di- and/or polyisocyanates, which comprises accomplishing the material coupling via the separation of the reaction mixture obtained in process stage A into process stages B and C, by in process stage A, reacting an aqueous alkylene oxide with carbon dioxide to give a reaction mixture comprising alkylene carbonate, hydrolyzing a portion of the alkylene carbonate-comprising reaction mixture obtained in process stage A to glycol in process stage B, dewatering the remaining alkylene carbonate-comprising stream of the reaction mixture from process stage A in process stage C, in process stage D, synthesizing amine by hydrogenating an aromatic nitro compound or a nitrile, in process stage E, transesterifying the dewatered alkylene carbonate-comprising mixture from process stage C with a monohydroxy alcohol to give the corresponding dia

Abstract: The content of the invention is a process for preparing urethanes by reaction of aromatic amines with a dialkyl carbonate, wherein the alkyl radical of the organic dialkyl carbonate comprises 4-18 carbon atoms and is branched in the 2 position, and the reaction is performed in the presence of a substoichiometric amount of base, based on the amino groups.

Abstract: Process for preparing aromatic isocyanates by reacting the corresponding formamides with an oxygen-comprising gas over noble metal catalysts at temperatures of from 300 to 600° C. and a contact time of from 1 to 1000 ms, wherein: a. the formamide is vaporized before entering the reaction zone, b. the reaction mixture obtained is quenched with an alcohol-comprising quenching liquid and c. the urethane formed is dissociated into isocyanate and alcohol.

Abstract: A process is proposed for preparing isocyanates by thermally cleaving carbamates to obtain a carbamate cleavage gas comprising the corresponding isocyanate and the corresponding alcohol, which comprises quenching the carbamate cleavage gas in the presence of an ether which functions as an inhibitor for the reverse reaction of the isocyanate with the alcohol.

Abstract: The present invention relates to a process for preparing aminopolycarboxylates proceeding from an amino acid which, in a first process step is reacted with ethylene oxide to give an intermediate mixture comprising the corresponding dialkanolamine, and then the intermediate mixture, in a second process step is converted catalytically using a base to the corresponding aminopolycarboxylate, wherein the amino acid, before the reaction with ethylene oxide in the first process step, is supplied to a partial neutralization with 0.70 to 0.99 equivalent of base per acid group, or, in the first process step, an amino acid which has already been partly neutralized with 0.70 to 0.99 equivalent of base per acid group is used.

Abstract: A process for preparing urethanes by reacting aromatic diamines with a dialkyl carbonate, wherein the alkyl radical of the organic dialkyl carbonate comprises 2-18 carbon atoms and one or more heteroatoms and the reaction is performed in the presence of a catalyst.

Abstract: The invention relates to a process for the preparation of formamides by reacting aromatic amines with a formic acid ester in the presence of a catalyst, wherein the catalyst is a phosphorus-containing acid or a Lewis-acidic metal salt.

Abstract: The invention relates to a process for preparing isocyanates by thermal dissociation of carbamates and separation by distillation of the reaction mixture from the carbamate dissociation, comprising the corresponding isocyanate and the corresponding alcohol, by distillation in a column (K) having an enrichment section (V) and a stripping section (A), where the carbamate (1) is introduced between the enrichment section (V) and the stripping section (A) and the isocyanate is taken off as a constituent of the bottom stream (2) and the alcohol is taken off as a constituent of the overhead stream (3) from the column (K), in the presence of an inert solvent, wherein an intermediate boiler having a boiling point between the boiling point of the isocyanate and the boiling point of the alcohol under the operating conditions of the carbamate dissociation is used as inert solvent and is fed as external runback (4) in liquid form in a purity of >95% by weight, based on the total weight of the external runback (4), in t

Abstract: A process for preparing aminopolycarboxylates proceeding from the corresponding polyalkanolamines by oxidative dehydrogenation in the presence of a catalyst comprising 1 to 90% by weight of copper, based on the total weight of the catalyst, using a base, which comprises first performing a partial conversion of the polyalkanolamine to a reaction mixture comprising the aminopolycarboxylate at a temperature in the range from 140 to 180° C. until at least 10 to 90 mol% of the polyalkanolamine has been depleted, and then continuing the conversion at elevated temperature.

Abstract: Process for preparing one or more complexing agents selected from methylglycinediacetic acid, glutamic acid diacetic acid and salts thereof Process for preparing one or more complexing agents selected from methylglycinediacetic acid, glutamic acid diacetic acid and salts thereof by catalytic dehydrogenation of N,N-bis(2-hydroxyethyl)alanine and/or N,N-bis(2-hydroxyethyl)glutamic acid and/or salts thereof in the presence of alkali metal hydroxide, where a catalyst comprising copper and zirconium dioxide is used, the activation of which is a reduction, wherein the precursor of the catalyst in question has a degree of crystallization K, defined as K = I K · 100 I K + I A , in the range from 0 to 50%.

Abstract: The invention relates to a process for obtaining a dialkyl carbonate and an alkylene glycol from a stream comprising dialkyl carbonate, alkylene carbonate, alkylene glycol and alcohol, comprising the following steps: (a) distillatively removing a stream (5) comprising dialkyl carbonate and alkylene glycol as a heteroazeotrope from the stream comprising dialkyl carbonate, alkylene carbonate, alkylene glycol and alcohol in a first distillation stage (1), (b) separating the stream (5) comprising dialkyl carbonate and alkylene glycol as a heteroazeotrope into a first crude product stream (27) comprising essentially di-alkyl carbonate and a second crude product stream (29) comprising essentially alkylene glycol in an apparatus for phase separation (25).

Abstract: What is proposed is a process for preparing aminopolycarboxylates proceeding from the corresponding polyalkanolamines by oxidative dehydrogenation in the presence of a catalyst comprising 1 to 90% by weight of copper, based on the total weight of the catalyst, using a base, which comprises first performing a partial conversion of the polyalkanolamine to a reaction mixture comprising the aminopolycarboxylate at a temperature in the range from 140 to 180° C. until at least 10 to 90 mol % of the polyalkanolamine has been depleted, and then continuing the conversion at elevated temperature.

Abstract: The present invention relates to a process for preparing aminopolycarboxylates proceeding from an amino acid which, in a first process step is reacted with ethylene oxide to give an intermediate mixture comprising the corresponding dialkanolamine, and then the intermediate mixture, in a second process step is converted catalytically using a base to the corresponding aminopolycarboxylate, wherein the amino acid, before the reaction with ethylene oxide in the first process step, is supplied to a partial neutralization with 0.70 to 0.99 equivalent of base per acid group, or, in the first process step, an amino acid which has already been partly neutralized with 0.70 to 0.99 equivalent of base per acid group is used.

Abstract: The invention relates to a process for the preparation of formamides by reacting aromatic amines with a formic acid ester in the presence of a catalyst, wherein the catalyst is a phosphorus-containing acid or a Lewis-acidic metal salt.

Abstract: Process for preparing aromatic isocyanates by reacting the corresponding formamides with an oxygen-comprising gas over noble metal catalysts at temperatures of from 300 to 600° C. and a contact time of from 1 to 1000 ms, wherein: a. the formamide is vaporized before entering the reaction zone, b. the reaction mixture obtained is quenched with an alcohol-comprising quenching liquid and c. the urethane formed is dissociated into isocyanate and alcohol.

Abstract: A process is proposed for preparing isocyanates by thermally cleaving carbamates to obtain a carbamate cleavage gas comprising the corresponding isocyanate and the corresponding alcohol, which comprises quenching the carbamate cleavage gas in the presence of an ether which functions as an inhibitor for the reverse reaction of the isocyanate with the alcohol.