Process for preparing hydrolytically stable poly (ethylene-2,6-naphthalene dicarboxylate) polymers

摘要

The present invention relates to a process for preparing poly(ethylene-2,6-naphthalene dicarboxylate) polymers wherein a low concentrations of an alkali metal salt is present. More specifically, 15 ppm to 100 ppm of an alkali metal derived from an alkali metal salt is added in the melt polymerization reaction mixture during formation of such polymers. The polymers are useful in applications where improved hydrolytic stability at elevated temperatures and high humidity (>50% relative humidity) are required.