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. 05, 2015
Filed:
Jun. 27, 2011
Applicants:
Tatsuya Nagano, Tokai, JP;
Tsuyoshi Tanaka, Nagoya, JP;
Hiroyuki Ome, Tokai, JP;
Inventors:
Assignee:
Toray Industries, Inc., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G 63/91 (2006.01); C08G 63/06 (2006.01); C08G 63/08 (2006.01); C08G 63/80 (2006.01);
U.S. Cl.
CPC ...
C08G 63/06 (2013.01); C08G 63/08 (2013.01); C08G 63/80 (2013.01);
Abstract
A method of producing a poly(lactic acid) resin includes carrying out direct polycondensation using lactic acid as a main raw material to prepare a crystallized prepolymer having a weight average molecular weight of 5,000 to 25,000, an enthalpy of fusion ΔHm of 50 to 65 J/g and an acid value A mol/ton satisfying (1) below:450/(Mw/10,000−0.14)<<950/(Mw/10,000−0.14)  (1)(wherein Mw represents weight average molecular weight of the crystallized prepolymer); and subjecting the crystallized prepolymer to solid-phase polymerization.