Addition of non-reactive uv absorbers during polyester synthesis

Abstract

A method of incorporating a UV light absorber into a polyester during the esterification or the condensation process by selecting the UV absorber from a class that is substantially not reactive with the polyester raw materials, is stable in the conditions of polycondensation or polymerization, and does not suffer loss through volatilization, resulting in an incorporation yield of 70% or higher, preferably 90% or higher. One embodiment comprises selecting the appropriate compound from the class of triazines and incorporating is as a solid powder in the beginning of the esterification. Another embodiment comprises selecting the appropriate compound from the class of triazines and incorporating it in the form of slurry during the time interval between esterification and condensation. Other embodiments include novel resins and films made by the UV absorber containing polyester resin made by the methods disclosed herein.