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:
Oct. 12, 2010
Filed:
Jun. 13, 2007
Tomoyuki Ogawa, Fukushima-Ken, JP;
Masaru Kagoshima, Fukushima-Ken, JP;
Tomoyuki Ogawa, Fukushima-Ken, JP;
Masaru Kagoshima, Fukushima-Ken, JP;
Kureha Corporation, Tokyo, JP;
Abstract
Glycolide production through depolymerization of glycolic acid oligomer is stabilized by controlling impurities in the glycolic acid oligomer to allow economical and effective production of glycolide. More specifically, the depolymerization system is controlled to suppress an effective concentration (x+100y wt. %) of depolymerization-obstructing substances calculated as a total of a concentration calculated as diglycolic acid (of x wt. %) of hydroxyl group-free impurity carboxylic acids (A) and 100 times a concentration calculated as ammonia (of y wt. %) of nitrogen-containing substances (B), respectively with respect to the starting glycolic acid oligomer in the depolymerization system, to at most 15 wt. %.