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:
Sep. 14, 1999
Filed:
Oct. 10, 1997
Applicant:
Inventors:
Norio Yanagisawa, Yokkaichi, JP;
Toshikazu Murayama, Yokkaichi, JP;
Yorozu Yokomori, Ichihara, JP;
Yoshiharu Kimura, Ohmihachiman, JP;
Nobuko Tsuzaki, Yokkaichi, JP;
Assignee:
Kyowa Hakko Kogyo Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528361 ; 528354 ; 528357 ;
Abstract
The present invention provides a process for producing polyhydroxycarboxylic acids which have a weight-average molecular weight of 50,000 or above and which are excellent as biodegradable plastics by polycondensing hydroxycarboxylic acids or oligomers thereof in the presence of an inorganic solid acid catalyst in combination with an alkali metal or an alkaline earth metal.