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:
Apr. 21, 1987
Filed:
Jul. 18, 1984
Martin Bartmann, Recklinghausen, DE;
Hanns-Jorg Bax, Marl, DE;
Klaus Burzin, Marl, DE;
Wilfried Ribbing, Dorsten, DE;
Srinivasan Sridhar, Marl, DE;
Chemische Werke Huls Aktiengesellschaft, Marl, DE;
Abstract
The invention relates to a process for purifying polyphenylene oxides obtained by interruption of the copper-amine catalyzed polycondensation of di-ortho-substituted phenols, where in said process the reaction mixture is subjected to a 'reaction-extraction' (i.e., an extraction which is accompanied by reaction) with water or stream, at a temperature of 60.degree. to 150.degree. C. It is particularly advantageous if the starting mixture in the inventive process comprises a solution of the polyphenylene oxide wherein the reaction has been interrupted by water and CO.sub.2, which solution is mixed into a toluene/water mixture; and further if the 'reaction-extraction' is carried out in the presence of an alkanolamine and a stabilizer.