Process for producing a high purity caprolactam
US5525725A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Aug 19, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D201/16
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for producing a high purity caprolactam is disclosed in which a crude caprolactam obtained by a catalytic rearrangement of cyclohexanone oxime is subjected (1) to mixing, while stirring, with at least one hydrocarbon selected from the group consisting of aliphatic hydrocarbons and alicyclic hydrocarbons to form a liquid-liquid, two-layer liquid mixture, and then crystallizing caprolactam out of the liquid mixture; (2) to mixing with both at least one hydrocarbon selected from the group consisting of aliphatic hydrocarbons and alicyclic hydrocarbons, and water to form a liquid mixture, separating the liquid mixture into a hydrocarbon layer and a water layer, and then recovering caprolactam from the water layer; or (3) to distillation in the co-presence of at least one aliphatic saturated hydrocarbon of 10 to 18 carbon atoms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.