Patent ID: 7541407

Claim:
A method for incorporating a UV light absorbing compound into a polyester prepared using direct esterification of reactants comprising a dicarboxylic acid and a diol, said method comprising: a. combining said reactants in an esterifying reactor under conditions sufficient to form an esterified product comprising at least one of: an ester, an oligomer, a low molecular weight polyester and mixtures thereof; b. polymerizing the esterified product in a polycondensation reactor to form a polyester; and c. adding at least one UV absorbing compound to at least one of said esterification reactor or polycondensation reactor when at least 50% of the carboxy groups initially present in the reactants have been esterified, wherein said UV absorbing compound includes at least one 4-oxybenzylidene radical of Formula I: wherein X is hydrogen or up to two moieties selected from the group consisting of hydroxy, C 1 -C 6 alkyl, C 1 -C 6 alkoxy and halogen, and wherein the UV absorbing compound includes a polyester reactive group.