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:
May. 11, 2010
Filed:
Sep. 19, 2007
Satoshi Nakagawa, Himeji, JP;
Satoshi Nakagawa, Himeji, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
In a production method in which an acrylic acid-containing solution obtained from an acrylic acid-containing gas (or an acrylic acid-containing liquid obtained simply by subjecting the acrylic acid-containing solution to a separation process of reaction by-products) is directly subjected to a crystallization process, the crystallization process can't be carried out smoothly in an unsteady state (when the concentration of water in the acrylic acid-containing solution is high). The present invention aims to provide a method for collecting the purified acrylic acid having high purity in good yield even in an unsteady state. When the acrylic acid-containing solutionsandhave a concentration of water higher than 10 mass % (unsteady state), the purified acrylic acidandor the acrylic acid-containing solutioncontaining 10 mass % or less of water is mixed therewith to make the concentration of water 10 mass % or less [a] [b]. Alternatively, when the acrylic acid-containing solutionsandhave a concentration of water higher than 10 mass %, it is used as an absorption liquid [c]. Thereafter, the crystallization process is carried out.