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. 14, 2015
Filed:
Jul. 18, 2012
Tsuyoshi Tanaka, Nagoya, JP;
Sadanori Kumazawa, Nagoya, JP;
Hiroyuki Ome, Tokai, JP;
Toray Industries, Inc., Tokyo, JP;
Abstract
The present invention is directed to a method for producing a polylactic acid resin, including the step of subjecting a crystallized prepolymer, which is a prepolymer including a lactic acid unit as a main component, and has an optical purity (Ea) of 60 to 94%, a weight average molecular weight of 5,000 to 100,000, and a crystal melting enthalpy (ΔHma) of 4 to 50 J/g, to solid phase polymerization. According to the present invention, it is possible to obtain a polylactic acid resin which is excellent in moldability upon melt processing and drawdown resistance upon melt processing, and is also excellent in hydrolysis resistance.