Patent · US Expired

Method for making caprolactam from impure ACN wherein ammonia and water are removed from crude caprolactam in a simple separation step and then THA is removed from the resulting caprolactam melt

US6716977B1 · kind B1 · utility

2Cited by

4References

2Claims

0Family size

Assignee

E.I. DU PONT DE NEMOURS AND COMPANY · US

Inventors

Gregory S. Kirby · Avondale, US
John J. Ostermaier · Wilmington, US

Key dates

Filing date	Jun 17, 2003
Grant date	Apr 6, 2004
Priority date	—
Expiry date	Jun 17, 2023

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07D223/04
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

Method for making caprolactam from 6-aminocapronitrile that contains greater than 500 ppm tetrahydroazepine and its derivatives (THA) in which ammonia and water are removed from crude caprolactam in a single separation step and then THA is removed from the resulting caprolactam melt.

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