摘要:
A process for preparing a xylylenediamine by heterogeneously catalyzed hydrogenation of a phthalonitrile, wherein the hydrogenation is carried out in the presence of a cobalt skeletal catalyst, of an alkali metal hydroxide and of an alcohol and/or ether as the solvent, at an absolute pressure in the range from 1 to 100 bar and a temperature in the range from 40 to 150° C.
摘要:
A process for preparing a xylylenediamine by heterogeneously catalyzed hydrogenation of a phthalonitrile, wherein the hydrogenation is carried out in the presence of a nickel catalyst, of water, of an alkali metal hydroxide and of an ether as a solvent, at an absolute pressure in the range from 1 to 100 bar, at a temperature in the range from 40 to 150° C. and without addition of ammonia.
摘要:
The invention relates to a process for preparing 4-[aminoalkoxy]benzylamines of the general formula (I) by catalytically hydrogenating 4-[aminoalkoxy]benzonitriles of the general formula (II) where, in the compounds of the general formulae I and II, R1 is C1-C8-alkylene, R2 and R3 are each independently C1-C8-alkyl or are joined to give a ring which may additionally contain a heteroatom, which comprises carrying out the hydrogenation at elevated pressure and elevated temperatures. The invention further relates to a process for preparing the intermediate (II).
摘要:
Process for preparing a symmetrical secondary amine by reaction of a primary amine in the presence of hydrogen and a catalyst whose preparation has involved precipitation of catalytically active components onto monoclinic, tetragonal or cubic zirconium dioxide.
摘要:
The invention relates to a method for removing, by distillation, 6-aminocapronitrile from mixtures that contain 6-aminocapronitrile, adipodinitrile and hexamethylenediamine, by a) removing the hexamethylenediamine from the mixture while obtaining a mixture (I) that has a hexamethylenediamine content of less than 1 wt. -%, b) removing completely or partially the 6-aminocapronitrile from mixture (I) while obtaining a mixture (II) whose content in substances that have a higher boiling point as 6-aminocapronitrile under distillation conditions and that cannot be formed by dimerization reactions when 6-aminocapronitrile is thermally treated is less than 1 wt. -%, and c) completely or partially removing from mixture (II) the hexamethylenediamine that might be present while obtaining a mixture (IV) whose hexamethylenediamine content is higher than that of mixture (II), and a mixture (V) whose hexamethylenediamine content is lower than that of mixture (II).
摘要:
The invention relates to a method for increasing yield in the production of polyvalent alcohols, especially trimethylolpropane, obtained by condensing formaldehyde with a higher aldehyde. According to the inventive method, acid treatment is carried out on a mixture (high-boiling fraction) that is obtained by reprocessing, contains derivatives of said alcohols and has a higher boiling point than the respective alcohol, and the polyvalent alcohol is recovered from the acid-treated high-boiling fraction. The inventive method is characterised in that the water content of the high-boiling fraction amounts to between 20 and 90 wt. % in relation to the entire mixture of the high-boiling fraction and water.
摘要:
Polyalkeneamines of the formula (I) where R1, R2, R3, R4, R5 and R6 may have different meanings, are prepared by a process in which a polyalkene epoxide is reacted with an amine and the amino alcohol is dehydrated and reduced to give the compound of the formula (I).
摘要:
A process is provided for the regeneration of a heterogeneous catalyst used for the preparation of compounds containing NH2 groups by the hydrogenation, with hydrogen, of compounds containing at least one unsaturated carbon-nitrogen bond, wherein a) the feed of the compound to be hydrogenated is stopped and b) the heterogeneous catalyst is treated with a compound of the formula R1R2N—CO—R3 (I), in which R1 is hydrogen or C1-C4 alkyl and R2, R3 independently of one another are each hydrogen or C1-C4 alkyl or together are a C3-C6 alkylene group, or mixtures of such compounds, at a pressure ranging from 0.1 to 30 MPa and a temperature ranging from 100 to 300° C., with the proviso that the compound of formula (I) is in liquid form during the treatment.
摘要:
A process for preparing a polymer, which comprises a) reacting a mixture (I) containing 6-aminocapronitrile and water in the presence of a catalyst to obtain a mixture (II) containing caprolactam, ammonia, water, high boilers and low boilers, then b) removing ammonia from mixture (II) to obtain a mixture (III) containing caprolactam, water, high boilers and low boilers, then c) removing all or some of the water from mixture (III) to obtain a mixture (IV) containing caprolactam, high boilers and low boilers and then d) feeding mixture (IV) to a polymerization reaction, and also the polymer obtainable by this process, the use of the polymer for producing fibers, sheetlike structures and moldings, and also fibers, sheetlike structures and moldings obtainable using such a polymer.
摘要:
The invention relates to a process for preparing essentially formic acid-free N-alkyl-N′-methylalkyleneureas of the formula with R1=H or CH3, R2=CnH2n+1 with n=1-4 and x=0 or 1, from the corresponding alkyleneureas by reaction with monomeric or polymerized formaldehyde in the presence of formic acid. This entails feeding the mixture, obtained in the reaction, of N-alkyl-N′-methylalkyleneurea and formic acid to the upper region of a distillation column, distilling without further additions and removing essentially formic acid-free N-alkyl-N′-methylalkyleneurea in the lower region of the column. The process parameters are set so that the pressure in the upper region of the column is at a higher level than in the lower region of the column, and the difference in pressure between the upper and lower regions of the column is from 10 to 100 mbar, and the temperature in the lower region of the column is higher than in the upper region of the column, with the difference in temperature between the upper and lower regions of the column being from 40° C. to 210° C.