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, 2002
Filed:
Mar. 09, 2001
Yuji Terado, Fukuoka, JP;
Hiroshi Suizu, Tokyo, JP;
Masatoshi Takagi, Chiba, JP;
Masanobu Ajioka, Fukuoka, JP;
Shoji Hiraoka, Yamaguchi, JP;
Masayuki Sakai, Yamaguchi, JP;
Hiroyuki Suzuki, Fukuoka, JP;
Hiroshi Kimura, Chiba, JP;
Shinji Ogawa, Fukuoka, JP;
Yasushi Kotaki, Fukuoka, JP;
Mitsui Chemicals, Inc., , JP;
Abstract
A process for producing aliphatic polyester wherein a crystallized aliphatic polyester prepolymer formed from an aliphatic dihydric alcohol and an aliphatic dicarboxylic acid and having a weight-average molecular weight of 2,000 to 100,000 is caused to undergo solid-phase polymerization in the presence of a volatile catalyst to make an aliphatic polyester having a weight-average molecular weight of 50,000 to 1,000,000. This process is more efficient than any prior process calling for a complicated step for catalyst removal, since it enables the removal of the catalyst from the reaction system during and/or after solid-phase polymerization. The polyester is comparable in stability to any aliphatic polyester having any catalyst removed therefrom.