摘要:
A process for the preparation of caprolactam is provided, wherein a) a mixture (I) containing 6-aminocapronitrile and water is reacted in the gas phase, in the presence of a catalyst, to give a mixture (II) containing caprolactam, ammonia, water, high-boiling components and low-boiling components, b) ammonia is then removed from the mixture (II) to give a mixture (III) containing caprolactam, water, high-boiling components and low-boiling components, c) water is then removed from the mixture (III) to give a mixture (IV) containing caprolactam, high-boiling components and low-boiling components, and d) a solid (V) containing caprolactam is then obtained from the mixture (IV) by crystallization, the proportion by weight of caprolactam in the solid (V) being greater than in the mixture (IV).
摘要:
A process for the preparation of caprolactam is provided, wherein a) a mixture (I) containing 6-aminocapronitrile and water is reacted in the liquid phase, in the presence of a catalyst, to give a mixture (II) containing caprolactam, ammonia, water, high-boiling components and low-boiling components, b) ammonia is then removed from the mixture (II) to give a mixture (III) containing caprolactam, water, high-boiling components and low-boiling components, c) water is then removed from the mixture (III) to give a mixture (IV) containing caprolactam, high-boiling components and low-boiling components, and d) a solid (V) containing caprolactam is then obtained from the mixture (IV) by crystallization, the proportion by weight of caprolactam in the solid (V) being greater than in the mixture (IV).
摘要:
A process for preparing caprolactam by reacting 6-aminocapronitrile with water in the presence of catalysts comprises using a starting mixture of 6-aminocapronitrile and the tetrahydroazepine derivative of the formula and conducting the reaction in liquid phase in the presence of a heterogeneous catalyst. Also describes a process for preparing said tetrahydroazepine derivative I and its use for preparing caprolactam and polycaprolactam.
摘要:
A process for hydrogenating a compound in the group of the imines or enamines I to an amine II in the presence of a nitrile III, said nitrile III being essentially not hydrogenated comprises reacting a mixture comprising a compound I and a nitrile III with a gas comprising molecular hydrogen in the presence of a catalyst IV.
摘要:
Caprolactam and hexamethylenediamine are prepared simultaneously starting from adiponitrile by a process in which (a) adiponitrile is partially hydrogenated to give a mixture containing essentially 6-aminocapronitrile, hexamethylenediamine, ammonia, adiponitrile and hexamethyleneimine, (b) the mixture obtained in (a) is subjected to a distillation to give ammonia as the top product and a bottom product I, (c) the bottom product I containing essentially 6-aminocapronitrile, hexamethylenediamine, adiponitrile, hexamethyleneimine, inert compound A and ammonia, the ammonia content being lower than that of the mixture used in stage (b), is subjected to a second distillation to give a mixture comprising the inert compound A and ammonia as the top product and a bottom product II, (d) the bottom product II is subjected, in a third column, to a distillation to give the inert compound A as the top product and a bottom product III, (e) the bottom product III is subjected, in a fourth column, to a distillation to give a top product KP1, containing essentially hexamethyleneimine and a bottom product IV, (f) the top product KP1 is subjected, in a fifth column, to a distillation to give a top product KP2, which contains essentially hexamethyleneimine, and (g) the bottom product IV containing essentially 6-aminocapronitrile and adiponitrile is subjected, in a sixth column, to a distillation to give 6-aminocapronitrile, and the 6-aminocapronitrile thus obtained is then cyclized to give caprolactam.
摘要:
In a process for producing polyamides by polymerization of lactams in the presence of metal oxides as heterogeneous catalysts, the metal oxides are used in a form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture in the course of or on completion of the polymerization.
摘要:
Crude capronitrile is purified by hydrogenation, subsequent treatment in an acidic medium and subsequent distillation in an alkaline medium, by a process in which(a) 6-aminocapronitrile is converted into crude caprolactam by reaction with water,(b) high boilers and low boilers are separated off from the crude caprolactam from step (a),(c) the crude caprolactam from step (b) is treated with hydrogen at from 50.degree. to 150.degree. C. and from 1.5 to 250 bar in the presence of a hydrogenation catalyst and, if desired, of a solvent to give a mixture A,(d1) mixture A in a solvent is passed, at from 30.degree. to 80.degree. C. and from 1 to 5 bar, over an ion exchanger containing terminal acid groups to give a mixture B1, or(d2) mixture A is distilled in the presence of sulfuric acid, any solvent present being removed before the addition of the sulfuric acid, to give a mixture B2, and(e) mixture B1 or mixture B2 is distilled in the presence of a base to give pure caprolactam.
摘要:
A process for preparing a secondary or tertiary 2-methyl-1,5-pen-tanediamine of the formula I where R1 and R2 are H, C1-C20-alkyl, C3-C8-cycloalkyl, aryl, C7-C20-arylalkyl, where the radicals R1 and R2 may bear substituents selected from the group consisting of C1-C20-alkyl, C1-C20-alkoxy, C6-C20-aryloxy and hydroxy, and R1 and R2 are not simultaneously hydrogen, or R1 and R2 are together an unsubstituted or C1-C20-alkyl- and/or C1-C20-alkoxy-substituted C3-C7-alkylene chain which may, if desired, be interrupted by one or two O or NR3 groups, where R3 is H or C1-C20-alkyl comprises reacting 2-methylglutarodinitrile with a primary or secondary amine of the formula R1R2NH and hydrogen at from 50 to 250° C. and pressures of from 0.5 to 35 MPa in the presence of an oxidic supported catalyst comprising one or more noble metals which has been treated with hydrogen at from 50 to 300° C. for at least 0.5 hour before use. The compound 1,5-bis(dimethylamino)-2-methylpentane is also claimed.