Patent ID: 7759449

Claim:
A method for introducing additives into polyethylene terephthalate, comprising: polymerizing polyethylene terephthalate precursors via melt phase polycondensation to form polyethylene terephthalate polymers possessing sufficient molecular weight to facilitate polymer processing; and thereafter, introducing an additive into the polyethylene terephthalate polymers via a reactive carrier that has a molecular weight of between about 300 and 10,000 g/mol, the reactive carrier being a delivery vehicle for the additive; wherein the additive is introduced to the polyethylene terephthalate polymers in quantities such that its concentration in the polyethylene terephthalate polymers is less than about one weight percent; and wherein the reactive carrier is introduced to the polyethylene terephthalate polymers in quantities such that bulk properties of the polyethylene terephthalate polymers are not significantly affected.