Process for adding nitrogen containing methine light absorbers to poly(ethylene terephthalate)

摘要

A method for incorporating a nitrogen containing methine light absorbing compound into a polyester prepared using direct esterification of reactants selected from a dicarboxylic acid and a diol, the method comprising reacting the reactants in an esterifying reactor under conditions sufficient to form an esterified product including at least one of an ester, an oligomer, or mixture having an ester and a mixture of low molecular weight polyester; polymerizing the esterified product in a polycondensation reactor to form a polyester; and adding the light absorbing compound to the esterified products when at least 50% of the carboxy groups initially present in the reactants have been esterified. Articles utilizing the light protected polyester are additionally disclosed.