RAW COPOLYESTER MATERIAL FOR AMORPHOUS FILM, HEAT-SHRINKABLE POLYESTER-BASED FILM, HEAT-SHRINKABLE LABEL, AND PACKAGE

摘要

A problem to be solved by the present invention is to provide a heat-shrinkable polyester film which exhibits a high heat-shrinking rate in a width direction, which exhibits a small natural shrinking rate in a longitudinal direction, and which exhibits small changes in the shrinking rate before and after the aging treatment, and to provide a raw material for preparing the heat-shrinkable polyester film as such.;An amorphous copolymerized polyester raw material for a film, characterized that, it satisfies the following requirements (1) to (4), and is used for producing a film:(1) The raw material contains ethylene terephthalate as a main constituent component, and contains from 18 % by mol to 30% by mol of neopentyl glycol when a total amount of a glycol component in a total polyester resin component is taken as 100% by mol; (2) The raw material contains from 8% by mol to 16% by mol of a constituent unit derived from diethylene glycol in the total amount (100% by mol) of the glycol component in the total polyester resin component; (3) The raw material has an intrinsic viscosity of from 0.70 dl/g to 0.86 dl/g; and (4) The raw material has a melt viscosity of 200Pa·S or less, when measured at a shear rate of 6080/S at 250°C.