Novel concept for low temperature curing powder coatings based on hyperbranched polyesters

The concept of using hyperbranched polymers as scaffolds for solid thermose t resin applications is described. A series of semi-crystalline methyacryla te-functional aliphatic polyesters has been synthesized and characterized f or applications as solid thermoset resins, e.g., powder coating resins. The polyester resins have been crosslinked by UV irradiation producing either amorphous or semi-crystalline crosslinked films depending on the initial st ructure. The resins are based on hyperbranched aliphatic polyester chains h ave been grafted and end-capped with methacrylate moieties. The resins exhi bit a rheological behavior suitable for low temperature curing powder coati ngs, i.e., films that can be readily formed and UV cured at temperatures be low 80 degrees C.