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.
摘要:
Amines are prepared by reacting aldehydes or ketones at elevated temperature under elevated pressure with nitrogen compounds selected from the group of ammonia, primary and secondary amines, and with hydrogen in the presence of a catalyst, wherein the catalytically active mass of the catalyst contains, after its preparation and before the treatment with hydrogen, 22 to 45% by weight of oxygen-containing compounds of zirconium, calculated as ZrO2, 1 to 30% by weight of oxygen-containing compounds of copper, calculated as CuO, 5 to 50% by weight of oxygen-containing compounds of nickel, calculated as NiO, where the molar ratio of nickel to copper is greater than 1, 5 to 50% by weight of oxygen-containing compounds of cobalt, calculated as CoO, 0 to 5% by weight of oxygen-containing compounds of molybdenum, calculated as MoO3, and 0 to 10% by weight of oxygen-containing compounds of aluminum and/or manganese, calculated as Al2O3 or MnO2.
摘要:
N-Methyl-2-pyrrolidone (NMP) is prepared by preparing a mixture comprising monomethylamine, dimethylamine and trimethylamine and ammonia in a first process step by reacting ammonia with methanol at elevated temperature in the presence of a catalyst, separating 10 off the ammonia, reacting the mixture comprising the methylamines with gamma-butyrolactone (&ggr;-BL), in a molar ratio of monomethylamine to &ggr;-BL of at least 1 in a second process step at elevated temperature and superatmospheric pressure, separating NMP and unreacted methylamines from the reaction product and returning unreacted methylamines to the first process step for reaction with methanol and ammonia.
摘要:
Neopentyl glycol hydroxypivalate (NGH) is isolated from a mixture containing NGH, lower- and higher-boiling products and inorganic salts and purified in a two-stage process, whereinin a first separation stage, the inorganic salts and part of the higher-boiling products are separated off in a wiped-film evaporator and a vapor stream consisting of NGH, lower- and higher-boiling products is discharged and fed to a heat exchanger and condensed therein,and, in a second separation stage, the resulting condensate is distilled in a rectification column from which NGH is taken off in a side stream and condensed. Further discharges of the rectification column containing lower-boiling products or higher-boiling products are separately taken off. The higher-boiling products which comprise residual NGH are partly or completely recycled to the lower region of the rectification column.
摘要:
A process for the preparation of 1,2,4-triazolium salts Ia ##STR1## where R.sup.1, and R.sup.2 and R.sup.3 are C-organic radicals, it being possible for R.sup.2 and R.sup.3 to be connected to give a 5- to 8-membered ring, R.sup.4 is hydrogen or an organic radical and A is an equivalent of an anion, by reacting an amidrazone II ##STR2## with a carboxylic acid III R.sup.4 --COOH II or a functional derivative (IIIa) of this acid, an anion A being formed from III or IIIa which, optionally, can be replaced by another anion. The triazolium salts have great industrial importance as catalysts for the preparation of acyloine from aldehydes.
摘要:
The present application relates to a process for preparing secondary amines by aminating excess primary or secondary alcohols with primary amines in the liquid phase in the presence of copper-comprising catalysts.