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:
Jul. 09, 2013
Filed:
Sep. 21, 2012
Gunze Limited, Ayabe, JP;
Gunze Limited, Ayabe-shi, Kyoto, JP;
Abstract
The present invention provides a method for reducing the content of a metal catalyst in a biodegradable and absorbable polymer that can be applied on an industrial scale and a method for producing a biodegradable and bioabsorbable polymer having a metal catalyst content of less than 1 ppm in terms of a metal. The method includes the steps of (1) copolymerizing lactide and ε-caprolactone at a molar ratio ranging from 40/60 to 60/40 or 65/35 to 85/15 in the presence of the metal catalyst to produce a copolymer; and (2) washing the copolymer with a mixed solvent comprising acetic acid and isopropanol at a volume ratio ranging from 25/75 to 45/55 or 45/55 to 55/45 at less than 40° C., and drying the copolymer.