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:
Jan. 15, 2008
Filed:
May. 07, 2004
Sei Nakahara, Himeji, JP;
Kazuhiko Sakamoto, Kobe, JP;
Yukihiro Matsumoto, Kobe, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
A method for distilling (meth)acrylic acid and/or the ester thereof by withdrawing vapor generated in a distillation column by distillation from the top of the column, condensing the vapor to give a condensate, and circulating part of the condensate as reflux liquid into the distillation column from the top thereof, comprising the step of adding a polymerization inhibitor to said condensate and said reflux liquid. This method enables maintaining the purity and quality of (meth)acrylic acid and/or the ester thereof at a certain level or higher, suppressing generation of polymers in the rectification column and suppressing polymerization of the condensate obtained by distillation in the incident facilities of the column such as condenser, condensate tank, and the like. In addition, the method enables reduction in the amount of polymerization inhibitor used while suppressing polymerization in the intermediate distillation columns (except the final rectification column).