Patent ID: 8445604

Claim:
A hot beverage cup lid made of a thermoformable resin composition comprising a biodegradable polymer comprising polybutylene succinate (PBS), and optionally comprising a filler, wherein, when present, the filler is a natural filler selected from the group consisting of cellulose fibers and powders, wherein the biodegradable polymer composition has a) a heat distortion index of from 50° C. to 140° C., b) a Tm in the range of 40° C. to 250° C., and c) a Ts value in the range of 60° C. to 150° C. wherein the heat distortion index is the temperature at which a polymer deforms under a specified load as determined by test procedure ASTM D648, Tm is the melting temperature of the polymer, and the Ts refers to the Vicat softening point wherein the Vicat softening point is measured as the temperature at which a polymer specimen is penetrated to a depth of 1 mm by a flat-ended needle with a 1 sq. mm circular or square cross-section.