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:
Oct. 03, 2017
Filed:
May. 31, 2016
Asahi Kasei Kabushiki Kaisha, Tokyo, JP;
Shigeru Yamamoto, Tokyo, JP;
Akira Mitsui, Tokyo, JP;
ASAHI KASEI KABUSHIKI KAISHA, Tokyo, JP;
Abstract
A method for producing a polyphenylene ether (PPE) provides the PPE that includes less gel and that is good in mechanical property and heat resistance, wherein the method includes a polymerization step of subjecting a phenol compound to oxidative polymerization in the presence of a polymerization catalyst in a good solvent for a polyphenylene ether to thereby provide a polyphenylene ether solution, a catalyst extraction step of adding an aqueous chelating agent solution to the polyphenylene ether solution and extracting the polymerization catalyst into the aqueous chelating agent solution to thereby provide a catalyst-removed polyphenylene ether solution, a concentration step of removing a part of the good solvent from the catalyst-removed polyphenylene ether solution to provide a concentrated polyphenylene ether solution, and a gel removal step of removing at least a visually observable chloroform-insoluble substance from the concentrated polyphenylene ether solution, to thereby provide a gel-removed polyphenylene ether solution.