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:
Jun. 29, 2004
Filed:
Jun. 12, 2001
Yoshio Hata, Ibaraki, JP;
Yasutaka Igari, Kobe, JP;
Takeda Chemical Industries, Ltd., Osaka, JP;
Abstract
A process for producing a biodegradable polymer having free carboxyl at the &ohgr;-end charcterized by polymerizing a cyclic ester compound in the presence of a hydroxymonocarboxylic acid derivative having protected carboxyl or a hydroxydicarboxylic acid derivative having protected carboxyl, and then deprotecting the thus obtained polymer having protected carboxyl at the &ohgr;-end. Use of the above process makes it easy to control the molecular weight of the target biodegradable polymer and the content of free carboxyl therein, thereby enabling the efficient production of a polymer having a high purity and being contaminated with littel catalyst remaining therein.