摘要:
Caprolactam is obtained from caprolactam-containing polymers in the presence of a base under reduced pressure by depolymerizing polymers which contain the repeating unit --[--N(H)--(CH.sub.2).sub.5 --C(O)--] or mixtures consisting essentially offrom 50 to 99.99% by weight of a polymer containing the repeating unit --[--N(H)--(CH.sub.2).sub.5 --C(O)--]--from 0.01 to 50% by weight of additives selected from the group consisting of inorganic fillers, organic and inorganic pigments and dyes,from 0 to 10% by weight of organic and/or inorganic additives,from 0 to 40% by weight of non-polyamide-containing polymers andfrom 0 to 20% by weight of polyamides, with the exception of polycaprolactam and copolyamides prepared from caprolactam,in at least two depolymerization reactors connected in series.
摘要:
A process for recovering caprolactam from oligomers and/or polymers of caprolactam comprises the following steps:a) treating oligomers and/or polymers of caprolactam with from 1 to 20 parts by weight of water per part by weight of oligomer or polymer at from 200.degree. to 350.degree. C. under superatmospheric pressure with a residence time of from 0.5 to 10 hours to form an aqueous reaction mixture comprising polycaprolactam, monomeric caprolactam and oligomers thereof, andb) passing the aqueous reaction mixture obtained in a) into a fluidized bed of alumina at from 250.degree. to 400.degree. C. to obtain a mixture of steam and caprolactam.
摘要:
Caprolactam is obtained from mixtures which contain polymers or thermoplastic molding materials having the repeating unit--N(H)--(CH.sub.2).sub.5 --C(O)--(a) by cleavage at elevated temperatures in the presence of a base under reduced pressure or (b) in the presence of water, by using a mixture essentially comprisingfrom 50 to 99.9% by weight of a polymer or of a thermoplastic molding material having the repeating unit--N(H)--(CH.sub.2).sub.5 --C(O)--from 0.1 to 50% by weight of additives selected from the group consisting of inorganic fillers, organic and inorganic pigments and dyes,from 0 to 10% by weight of organic and/or inorganic additives,from 0 to 40% by weight of non-polyamide-containing polymers andfrom 0 to 20% by weight of polyamides, with the exception of polycaprolactam and copolyamides prepared from caprolactam,and carrying out the cleavage in the presence of a base under reduced pressure, the water content of the mixture used being not more than 0.01% by weight, or carrying out the cleavage in the presence of water without the addition of acid or base at from 270.degree. to 350.degree. C. and a weight ratio of water to polymer or thermoplastic molding material of from 1:1 to 20:1 and in a reaction time of less than 3 hours.
摘要:
Caprolactam is recovered from polycaprolactam by hydrolyric cleavage of polycaprolactam with from 5 to 50 parts by weight of water per part by weight of polycaprolactam at from 200.degree. to 350.degree. C. under superatmospheric pressure to give an aqueous solution or suspension which contains monomeric caprolactam and oligomers thereof and may contain polycaprolactam and subsequent isolation of monomeric caprolactam from the aqueous solution or suspension by distillation or extraction, by a process in which the hydrolyric cleavage is carried out in the presence of an alkali metal hydroxide at a pH of from 5 to 10.
摘要:
Caprolactam is purified by oxidative treatment in which mixtures which essentially contain the caprolactam to be purified and unsaturated lactams are treated with oxygen or an oxygen-containing gas mixture in an alkaline medium.
摘要:
Caprolactam is purified by oxidative treatment in which mixtures which essentially contain the caprolactam to be purified and unsaturated lactams are treated with oxygen or an oxygen-containing gas mixture in an alkaline medium.
摘要:
In an improved process for the preparation of 6-aminocaproates by reacting a 5-formylvalerate with ammonia and hydrogen using an alkanol as a solvent in the presence of a hydrogenation catalyst at elevated temperatures and under superatmospheric pressure, the improvement comprises carrying out the reaction at from 40.degree. to 95.degree. C.
摘要:
A process for the preparation of 3-aminomethyl-3,5,5-trimethyl-cyclohexylamine from 3-cyano-3,5,5-trimethyl-cyclohexanone, wherein the following stages are carried out in discrete reaction chambers:a) the 3-cyano-3,5,5-trimethyl-cyclohexanone is reacted in a first reaction chamber with excess ammonia over an acidic metal oxide catalyst at a temperature of from 20.degree. to 150.degree. C. and a pressure of from 15 to 500 bar, andb) in a second reaction chamber, the reaction product from stage a) is hydrogenated with hydrogen at a temperature of from 60.degree. to 150.degree. C. and a pressure of from 50 to 300 bar in the presence of excess ammonia over a catalyst containing cobalt, nickel, ruthenium, and/or some other noble metal, which catalyst optionally contains a basic component or is supported by neutral or basic supporting material.
摘要:
Triphendioxazine dyes suitable for dyeing or printing hydroxyl- or amido-containing substrates have the formula ##STR1## where n is 0 or 1,m is 1 or 2,R.sup.1 and R.sup.2 are each independently of the other hydrogen, chlorine, bromine, hydroxysulfonyl, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, substituted or unsubstituted phenyl or substituted or unsubstituted phenoxy,R.sup.3 is halogen, carboxyl, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, vinylsulfonyl or the radical --SO.sub.2 --CH.sub.2 CH.sub.2 --Z, where Z is a leaving group, andQ.sup.1 and Q.sup.2 are each independently of the other a radical of the formula ##STR2## where R.sup.4 and R.sup.5 are each independently of the other hydrogen, C.sub.1 -C.sub.4 -alkyl or phenyl,R.sup.6 is hydrogen or a fiber-reactive radical,L.sup.1 and L.sup.2 are each independently of the other substituted or unsubstituted C.sub.2 -C.sub.8 -alkylene or phenylene,X is a chemical bond, oxygen, sulfur, imino, C.sub.1 -C.sub.4 -alkylimino, carbonyl or methylene, andY is oxygen or sulfur,with the proviso that if n is 0, R.sup.6 is a fiber-reactive radical, and that the hydroxysulfonyl groups are each ortho to the substituents Q.sup.1 and Q.sup.2.
摘要:
Caprolactam is prepared by heating a 6-aminocaproic ester in liquid phase in the presence of water to 230.degree.-350.degree. C. under superatmospheric pressure in a reaction medium comprising a liquid aromatic hydrocarbon having a boiling point of from 80.degree. to 240.degree. C. which is inert under reaction conditions, and isolating caprolactam from the reaction mixture.