Process for terminating polyphenylene ethers reactions with amino carboxylic acids and reducing agents

Claim 1

In a process for producing polyphenylene ethers which comprises reacting phenols with oxygen in the presence of a complex catalyst containing at least one metallic compound selected from the group consisting of copper compound, manganese compound and cobalt compound, the improvement which comprises terminating the polymerization reaction by adding an aminocarboxylic acid derivative and a reducing agent to the polymerization reaction mixture at a stage of the desired degree of polymerization of the resulting polyphenylene ether, said aminocarboxylic acid derivative being at least one member selected from the group consisting of polyalkylene polyamine polycarboxylic acids, cycloalkylene polyamine polycarboxylic acids, polyalkylene ether polyamine polycarboxylic acids, aminopolycarboxylic acids, aminocarboxylic acid, alkali metal or alkaline earth metal salts of these acids, and alkali metal/alkaline earth metal mixed salts of these acids, and said reducing agent being at least one member selected from the group consisting of sulfur suboxides, salts of lower oxyacids of sulfur, salts containing a metal in lower atomic valency of higher oxyacids or hydroacids, nitrogen-containing reducing compounds selected from the group consisting of hydroxylamine and salts thereof and hydrazine and boron hydride said aminocarboxylic acid derivative being added in an amount of at least 1 mole per mole of the metallic compound in said complex catalyst said reducing agent being added in an amount of 1.0 to 15.0 moles per mole of the metallic compound in the complex catalyst.