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:
Oct. 06, 2015
Filed:
Jun. 27, 2011
Yoshitake Takahashi, Aichi, JP;
Takuma Naotsuka, Aichi, JP;
Ken Sudo, Aichi, JP;
Hiroyuki Ome, Aichi, JP;
Yoshitake Takahashi, Aichi, JP;
Takuma Naotsuka, Aichi, JP;
Ken Sudo, Aichi, JP;
Hiroyuki Ome, Aichi, JP;
Toray Industries, Inc., , JP;
Abstract
A method of producing a polylactic acid block copolymer constituted of a segment(s) composed of L-lactic acid units and a segment(s) composed of D-lactic acid units, includes obtaining a mixture by mixing poly-L-lactic acid and poly-D-lactic acid one of which has a weight average molecular weight of 60,000 to 300,000 and the other of which has a weight average molecular weight of 10,000 to 50,000, the mixture having a weight average molecular weight of not less than 90,000 and a degree of stereocomplexation (Sc) satisfying: Sc=ΔHh/(ΔHl+ΔHh)×100>60 (wherein ΔHh represents the heat of fusion of stereocomplex crystals (J/g), and ΔHl represents the heat of fusion of crystals of poly-L-lactic acid alone and crystals of poly-D-lactic acid alone (J/g)); and subsequently subjecting the mixture to solid-phase polymerization at a temperature lower than the melting point of the mixture.