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:
Feb. 17, 1998
Filed:
Oct. 15, 1996
Shoji Tamai, Fukuoka-ken, JP;
Yukiko Mori, Fukuoka-ken, JP;
Kenichi Goto, Fukuoka-ken, JP;
Katsuji Watanabe, Fukuoka-ken, JP;
Osamu Kohgo, Fukuoka-ken, JP;
Kotaro Shimizu, Fukuoka-ken, JP;
Toshiyuki Kataoka, Fukuoka-ken, JP;
Takashi Kuroki, Kanagawa-ken, JP;
Wataru Yamashita, Fukuoka-ken, JP;
Hideki Mizuta, Fukuoka-ken, JP;
Teruyuki Nagata, Fukuoka-ken, JP;
Mitsu Toatsu Chemicals, Inc., Tokyo, JP;
Abstract
The invention provides a novel preparation process of a polycondensation type polymer, an excellent polymer which is represented by lactic acid and the preparation process of the polymer, a polycondensation agent used for the preparation process, and an intermediate. Specifically, the invention provides a preparation process of the polycondensation type polymer, for example, polyamide, polyimide, polythioester and polyester, comprising bonding a carboxyl group comprising compound with an active hydrogen group comprising compound in the presence of haloiminium salt. The invention provides excellent polylactic acid having a controlled D/L-isomer ratio in the repeating structural units and preparation process of polylactic acid, and further provides a haloiminium salt compound used for the preparation process and an intermediate compound of acid chloride.