The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1996
Filed:
Aug. 19, 1994
Yasuhiko Higashio, Toyonaka, JP;
Hiroshi Kajikuri, Ibaraki, JP;
Keisuke Sugita, Ibaraki, JP;
Hideki Doi, Niihama, JP;
Masanobu Matsubara, Niihama, JP;
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.