Obtaining caprolactam by cleavage of molten polycaprolactam

US5536831A · kind A · utility

Assignee

• BASF SE

Inventors

• Michael Kopietz · Frankfurt, DE
• Alan Handerman · Asheville, US
• Simon Jones · Leimen, DE
• Ulrich Kalck · Schifferstadt, DE
• Claus-Ulrich Priester · Ludwigshafen, DE
• Heinz Auer · Neulußheim, DE
• Josef Ritz · Ludwigshafen, DE
• Hugo Fuchs · Ludwigshafen, DE
• Paul Pijl · Bischofswerda, DE

Key dates

• Filing date: Dec 12, 1994
• Grant date: Jul 16, 1996
• Expiry date: Dec 12, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D201/12
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

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 of PA1 from 50 to 99.99% by weight of a polymer containing the repeating unit --[--N(H)--(CH.sub.2).sub.5 --C(O)--]-- PA1 from 0.01 to 50% by weight of additives selected from the group consisting of inorganic fillers, organic and inorganic pigments and dyes, PA1 from 0 to 10% by weight of organic and/or inorganic additives, PA1 from 0 to 40% by weight of non-polyamide-containing polymers and PA1 from 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.