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:
Sep. 08, 2020
Filed:
Mar. 30, 2017
Kuraray Co., Ltd., Kurashiki-shi, JP;
Universite DE Liege, Liege, BE;
Takumi Takayama, Kurashiki, JP;
Yusuke Amano, Kurashiki, JP;
Kazuhiko Maekawa, Kurashiki, JP;
Christophe Detrembleur, Liege, BE;
Antoine Debuigne, Liege, BE;
Christine Jerome, Liege, BE;
KURARAY CO., LTD., Kurashiki-shi, JP;
UNIVERSITE DE LIEGE, Liege, BE;
Abstract
A polyvinyl alcohol is produced in a method comprising: a polymerization step comprising polymerizing vinyl ester monomers by controlled radical polymerization in the presence of a radical initiator and an organic cobalt complex to obtain a polymer solution containing a polyvinyl ester; an extraction step comprising extracting a cobalt complex from the polymer solution by contacting an aqueous solution containing a water-soluble ligand with the polymer solution; and a saponification step comprising saponifying the polyvinyl ester after the extraction step to obtain a polyvinyl alcohol. A method for producing a polyvinyl alcohol is thus provided that has a narrow molecular weight distribution and a high number-average molecular weight with good hue and further good solubility in water.