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:
Dec. 02, 1980
Filed:
Sep. 17, 1979
Hideo Kawamura, Okazaki, JP;
Ichiro Fukami, Okazaki, JP;
Shuhei Wada, Okazaki, JP;
Fusayuki Yoshikawa, Okazaki, JP;
Nippon Ester Co., Ltd., Okazaki, JP;
Abstract
In a process for continuously producing polyester which comprises continuously polymerizing bis-.beta.-hydroxyethyl terephthalate and/or a lower polymer thereof using a plurality of vacuum polymerization reactors equipped with a stirrer disposed in series, the improvement which comprises automatically and continuously measuring stirring power or stirring axis reaction force of at least the final polymerization reactor among the polymerization reactors from which a polymer having a limiting viscosity (.eta.) of 0.25 or more is removed, and controlling the vacuum in the polymerization reactors based on changes in the stirring power or reaction force so that the stirring power or reaction force is kept at a prescribed level, by which the degree of polymerization of the polymer removed from the polymerization reactors is controlled. A process for producing a polyester spun fiber is also disclosed.