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:
May. 27, 2003
Filed:
Dec. 19, 2001
Toyota Jidosha Kabushiki Kaisha, Aichi-ken, JP;
Abstract
According to the present invention, a process for consistently producing lactide from ammonium lactate obtained by lactic fermentation, and a process for consistently producing polylactic acid from ammonium lactate obtained by lactic fermentation, are provided. A process for producing lactide, which comprises the steps of: (1) synthesizing lactate ester from ammonium lactate obtained by lactic fermentation; (2) polycondensing the lactate ester in the presence of a catalyst other than monobutyltin, whereby polylactic acid with a weight-average molecular weight of less than 15,000 (lactic acid prepolymer) is synthesized; and (3) depolymerizing the polylactic, whereby lactide is produced. A process for producing polylactic acid, which comprises the additional step of (4) ring-opening polymerizing said lactide, whereby polylactic acid is obtained. A process for producing lactate ester from ammonium lactate obtained by lactic fermentation.