Recovery of caprolactam from oligomers and/or polymers of caprolactam

US5700358A · kind A · utility

Assignee

• BASF SE

Inventors

• Hugo Fuchs · Ludwigshafen, DE
• Josef Ritz · Ludwigshafen, DE
• Gerald Neubauer · Weinheim, DE

Key dates

• Filing date: Mar 1, 1995
• Grant date: Dec 23, 1997
• Expiry date: Mar 1, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D201/16
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Caprolactam is recovered from oligomers and/or polymers of caprolactam by cleavage of oligomers and/or polymers of caprolactam and subsequent working up by distillation of the caprolactam obtained in the cleavage, by a process including PA1 (a) cleaving oligomers and/or polymers of caprolactam to obtain an aqueous reaction mixture which contains caprolactam, PA1 (b) removing water from the reaction mixture obtained under (a) to obtain a residue, PA1 (c) distilling the residue obtained under (b) in an acidic medium and PA1 (d) then distilling the distillate in an alkaline medium to obtain caprolactam, or PA1 (c') distilling the residue obtained under (b) in an alkaline medium and PA1 (d') then distilling the distillate in an acidic medium to obtain caprolactam.