HEAT-SHRINKABLE POLYESTER FILM AND POLYESTER RESIN USED FOR HEAT-SHRINKABLE FILM

摘要

PROBLEM TO BE SOLVED: To provide a heat-shrinkable polyester film having improved heat resistance and mechanical properties while maintaining its excellent shrinking properties. SOLUTION: A heat shrinkable polyester film is prepd. from a copolyester resin for a heat shrinkable film obtd. by copolymerizing an arom. dicarboxylic acid and ethylene glycol as main components and 2,6-naphthalenedicarboxylic acid as a copolymerizing component. It has a glass transition temp. in the range of 60-90 deg.C, a rate of heat shrinkage at 80 deg.C of >=10% a rate of heat shrinkage at 100 deg.C of >=20% and a rate of heat shrinkage in the direction perpendicular to the direction of shrinkage being a minimum in the temperature range of 80±25 deg.C.