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:
Jul. 13, 1999
Filed:
Apr. 07, 1997
Yoshihiko Kambara, Osaka, JP;
Mutsuo Matsumura, Osaka, JP;
Michiaki Umeno, Osaka, JP;
Yoshikazu Uehara, Osaka, JP;
Koichi Asao, Osaka, JP;
Mitsui Chemicals, Inc., Tokyo, JP;
Abstract
A method is disclosed for the concentration of an aqueous acrylamide solution prepared by hydration of acrylonitrile or an aqueous acrylamide solution substantially free of acrylonitrile. The method makes use of a concentration apparatus at least a part of whose solution-contacting section is made of a copper-containing material. The concentration is conducted while introducing an oxygen-containing gas into the apparatus. Use of this method can prevent formation, adhering, accumulation and the like of popcorn polymers inside the concentration apparatus upon concentration of the aqueous acrylamide solution, and can also produce high-quality acrylamide.