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:
Nov. 12, 1996
Filed:
May. 05, 1995
Applicant:
Inventors:
Rika Miyoshi, Hiroshima, JP;
Tadamoto Sakai, Hiroshima, JP;
Noriaki Hashimoto, Hiroshima, JP;
Yukihiro Sumihiro, Hiroshima, JP;
Kayoko Yokota, Hiroshima, JP;
Kunihiko Koyanagi, Hiroshima, JP;
Assignee:
The Japan Steel Works, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528354 ; 524755 ; 524784 ; 525408 ; 525411 ; 525415 ; 528271 ; 528274 ; 528275 ; 528283 ; 528357 ; 528361 ; 528480 ;
Abstract
A process for producing polylactic acid includes the steps of polycondensing lactic acid to a lactic acid prepolymer having a weight-average molecular weight of 10,000-50,000 in a batch-type polymerization reactor, and polycondensing the lactic acid prepolymer to lactic acid polymer having a weight-average molecular weight of at least 100,000 by means of a screw-type extruder.