Patent ID: 6300461
Filing Date: 2001-10-09
Classification: C08G

Abstract:
A method to reduce the yellowness index of polyphenylene ether resin, wherein the method comprises oxidative coupling in a reaction solution at least one monovalent phenol species using an oxygen containing gas and a complex metal catalyst to produce a polyphenylene ether resin having an intrinsic viscosity within the range of about 0.08 dl/g to about 0.16 dl/g as measured in chloroform at 25.degree. C.; recovering the complex metal catalyst with an aqueous solution and isolating the polyphenylene ether resin through devolatilization of the reaction solvent, wherein the devolatilization is accomplished at least in part with a devolatilization extruder maintained at a temperature less than about 275.degree. C.