Patent · US Expired

Recovery of caprolactam from distillation residues obtained in the purification of caprolactam

US5441607A · kind A · utility

6Cited by

6References

6Claims

0Family size

Assignee

BASF SE

Inventors

Hugo Fuchs · Ludwigshafen, DE
Josef Ritz · Ludwigshafen, DE
Hans J. Wilfinger · Schifferstadt, DE
David Weatherford · Mannheim, DE

Key dates

Filing date	Jun 27, 1994
Grant date	Aug 15, 1995
Priority date	—
Expiry date	Jun 27, 2014

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D201/16
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

Recovery of caprolactam and of an alkali metal carbonate from distillation residues which are obtained in the purification of caprolactam and contain caprolactam and/or oligomers and/or polymers of caprolactam and also alkali metal hydroxides by PA1 (a) melting the distillation residues, the caprolactam and/or oligomers and/or polymers of caprolactam and alkali metal hydroxides, PA1 (b) continuously removing caprolactam from the melt, PA1 (c) after removing caprolactam, cooling the melt and obtaining a residue, PA1 (d) dissolving the residue thus obtained in water and PA1 (e) subjecting the aqueous solution thus obtained to combustion with the formation of an alkali metal carbonate is described.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.