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. 10, 2013
Filed:
May. 07, 2010
Yoshitake Ishii, Himeji, JP;
Koji Ueno, Himeji, JP;
Yoshitake Ishii, Himeji, JP;
Koji Ueno, Himeji, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
The objective of the present invention is to provide a process for producing highly pure (meth) acrylic acid stably and efficiently with crystallization. The process for production of (meth)acrylic acid according to the present invention is characterized in comprising the steps of cooling a crude (meth)acrylic acid solution in a crystallization apparatus until the temperature of a cooling medium discharged from the crystallization apparatus is stabilized in the range of higher than the solidification point of the crude (meth)acrylic acid solution in the crystallization apparatus and not more than the solidification point plus 5° C.; then bringing the crude (meth)acrylic acid solution in the crystallization apparatus to a supercooled condition by setting the temperature of a cooling medium supplied to the crystallization apparatus at the temperature of not more than the solidification point of the crude (meth)acrylic acid solution minus 1° C.; and crystallizing (meth)acrylic acid from the crude (meth)acrylic acid solution.