Patent ID: 6759507
Filing Date: 2004-07-06
Classification: C08G,C08J

Abstract:
A method for producing polyphenylene ether, which comprises(a) a step for synthesizing polyphenylene ether by subjecting phenol to oxidative polymerization in the presence of a copper compound and amines in an aromatic compound solvent, (b) a step for precipitating polyphenylene ether particles by adding methanol into the solution of polyphenylene ether in the aromatic compound solvent obtained by the step (a), (c) a step for solid-liquid separating a slurry of polyphenylene ether obtained by the step (b), and then washing the separated polyphenylene ether particles with methanol to obtain the polyphenylene ether, (d) a step for adding water to a filtrate obtained by the step (c) to mix them, and then liquid-liquid separating the mixture into a phase consisting mainly of the aromatic compound and a phase consisting mainly of methanol and water, and (e) a step for supplying the phase consisting mainly of methanol and water, obtained at the step (d) to the middle portion of a distilled column to perform distillation, and separating out a distillate liquid consisting mainly of methanol, a bottom liquid consisting mainly of water and a side-cut liquid containing the amines by distillation, recycling the distillate liquid consisting mainly of methanol as methanol of the steps (b) and (c), and recycling the side-cut liquid as part of the filtrate of the step (d).