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:
Aug. 24, 2010
Filed:
Oct. 17, 2005
Tomoyuki Ogawa, Fukushima-Ken, JP;
Tomohiro Hoshi, Fukushima-Ken, JP;
Tsutomu Kushida, Fukushima-Ken, JP;
Kentaro Otawara, Fukushima-Ken, JP;
Tomoyuki Ogawa, Fukushima-Ken, JP;
Tomohiro Hoshi, Fukushima-Ken, JP;
Tsutomu Kushida, Fukushima-Ken, JP;
Kentaro Otawara, Fukushima-Ken, JP;
Kureha Corporation, Tokyo, JP;
Abstract
Disclosed is a process for purifying a hydroxycarboxylic acid, comprising: a crystallization step of subjecting a hydroxycarboxylic acid aqueous solution to crystallization for purification, a separation step of separating a hydroxycarboxylic acid crystal from a mother liquid, and a washing step of washing the hydroxycarboxylic acid crystal for further purification with a washing liquid, wherein the washing liquid is a hydroxycarboxylic acid aqueous solution. The purified or refined hydroxycarboxylic acid obtained through the above process is suitably used as a starting material for production of a polyhydroxycarboxylic acid. The above process is suitably included in a process for producing a cyclic ester and a process for producing a polyhydroxycarboxylic acid.