POLYESTER RESIN FOR HEAT-SHRINKABLE FILM, HEAT-SHRINKABLE FILM, HEAT-SHRINKABLE LABEL, AND PACKAGE

摘要

Provided is a polyester resin for a heat-shrinkable film, the polyester resin being capable of ensuring sufficient film-forming properties and film strength while reducing the film manufacturing cost for a heat-shrinkable film. The present invention discloses a polyester resin wherein, in all of the components of the polyester resin, ethylene glycol is the main component of diol components and terephthalic acid is the main component of dicarboxylic acid components, and if all of the diol components are considered to be 100 mol%, the content of neopentyl glycol is 18-32 mol% and the content of diethylene glycol is 7-15 mol%. Furthermore: (i) the intrinsic viscosity (IV) of the polyester resin is at least 0.65 dl/g and less than 0.70 dl/g; (ii) the carboxyl end group concentration (AV) in the polyester resin is 8-25 eq/t; and (iii) the color b value of the polyester resin in the L*a*b* color system is 1.0-8.0. Moreover, the polyester resin contains aluminum and phosphorous atoms, the content of aluminum atoms in the polyester resin is 15-40 ppm, and the molar ratio of phosphorous atoms to aluminum atoms in the polyester resin is 1.8-2.6.