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:
Aug. 20, 2002
Filed:
Oct. 18, 2000
Applicant:
Inventors:
Yoshinari Yamaguchi, Himeji, JP;
Hitoshi Yano, Suita, JP;
Akira Kurusu, Kyoto, JP;
Yuuji Shimasaki, Otsu, JP;
Assignee:
Nippon Shokubai Co LTD, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D 3/42 ; C07D / ;
U.S. Cl.
CPC ...
B01D 3/42 ; C07D / ;
Abstract
A process for recovering N-vinyl-2-pyrrolidone is provided which allows to recover N-vinyl-2-pyrrolidone efficiently and steadily and in high purity by continuous distillation from a mixed liquid containing N-vinyl-2-pyrrolidone, N-(2-hydroxyethyl)-2-pyrrolidone, compounds having a higher boiling point than N-vinyl-2-pyrrolidone and water. The process includes continuously distilling the mixed liquid using a distilling column, controlling the temperature of the bottom liquid of the distilling column at 180° C. or less.