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:
Sep. 28, 1999
Filed:
Mar. 31, 1997
Shin-ichi Sato, Kitakyusyu, JP;
Takahiro Oshida, Kitakyusyu, JP;
Hiroshi Izumikawa, Kitakyusyu, JP;
Akihiko Tanaka, Kitakyusyu, JP;
Eiichiro Koresawa, Kitakyusyu, JP;
Mitsubishi Chemical Corporation, Tokyo, JP;
Abstract
A purification process of N-vinylformamide, which comprises: providing a crude N-vinylformamide having an acetone-insoluble component content of not more than 400 ppm; and continuously feeding the crude N-vinylformamide into a fractionating tower, to obtain an N-vinylformamide having high purity. Also disclose is a continuous purification process of N-vinylformamide, which comprises the steps of: providing a crude N-vinylformamide; feeding the crude N-vinylformamide into a thin film evaporator to remove un-evaporated fraction from the system, and feeding the evaporated fraction containing N-vinylformamide into a fractionating tower, distilling the purified N-vinylformamide from the tower head, and discharging a bottom liquid containing N-vinylformamide from the tower bottom, and recycling the bottom liquid into the thin film evaporator to remove un-evaporated fraction from the system, and feeding the evaporated fraction into the fractionating tower.