Process for producing caprolactam through hydrolytic cleavage of molten polycaprolactam

Abstract

Caprolactam is obtained from caprolactam-containing polymers in the presence of superheated water by bringing polymers which contain the repeating unit --[--N(H)--(CH.sub.2).sub.5 --C(O)--]-- or mixtures consisting essentially of ______________________________________ from 40 to 99.9% by weight of a polymer containing the repeat- ing 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 and from 0 to 60% by weight of polyamides, with the exception of polycaprolactam and copolyamides prepared from caprolactam, ______________________________________ into contact with superheated water at from 280.degree. to 320.degree. C. and from 7.5 to 15 MPa and a weight ratio of water to polymer containing the repeating unit --[--N(H)--(CH.sub.2).sub.5 --C(O)--]-- of from 5:1 to 13:1 and in a reaction time of less than 3 hours, with the proviso that the reaction mixture, consisting essentially of water and the polymer used or the mixture used, contains no gaseous phase under the conditions of the hydrolysis.

Dependencies are inferred from the claim text.