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. 16, 2012
Filed:
Feb. 15, 2012
Mutsumi Maeda, Tokyo, JP;
Hiroaki Furukawa, Tokyo, JP;
Mutsumi Maeda, Tokyo, JP;
Hiroaki Furukawa, Tokyo, JP;
Asahi Kasei Chemicals Corporation, Tokyo, JP;
Abstract
Method for producing polyphenylene ether, comprising preparing a polymerization solution of 10-25 parts by mass of a phenolic compound (M) and 75-90 parts by mass of an aromatic solvent (A) with the total of the compound and the solvent being 100 parts by mass, and 0.1-10 parts by mass of a catalyst (C) containing a metal salt; performing oxidative polymerization of the phenolic compound (M) by passing oxygen-containing gas through polymerization solution; stopping polymerization by mixing aqueous chelating agent solution into polymerization solution; subjecting a diphenoquinone compound produced as a by-product to quinone binding process or removal by reduction; and obtaining polyphenylene ether by separating aqueous phase through liquid-liquid separation. In the method for producing a polyphenylene ether, 0.001-0.004 part by weight of an ion catalyst (D) is added into the polymerization solution before the liquid-liquid separation.