Patent ID: 7060781

Claim:
A process for preparing a polyphenylene ether, which comprises subjecting a 2,6-dimethylphenol composition having an m-cresol content of from 15 ppm to 700 ppm based on the weight of 2,6-dimethylphenol to oxidative polymerization using a catalyst and an oxygen-containing gas, wherein the catalyst comprises, as constituents thereof, a copper compound, a halogen compound and a diamine compound represented by the following formula (1): wherein R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom, a linear or branched C 1-6 alkyl group, with the proviso that they do not represent a hydrogen atom at the same time; and R 5 represents a linear or methyl-branched C 2-5 alkylene group.