| abstract |
[Problem] To provide a heat-shrinkable polyester film having sufficient thermal shrinkage characteristics in the main shrinkage direction as the longitudinal direction, low thermal shrinkage rate in the width direction perpendicular to the main shrinkage direction, and main shrinkage The shrinkage stress in the direction is not too high, and the attenuation of the shrinkage stress is small, so that the followability to the container as the packaged body at the time of shrinkage is high, and slack is unlikely to occur. [Solution] A heat-shrinkable polyester-based film characterized in that it is a heat-shrinkable polyester-based film whose main shrinkage direction is the longitudinal direction, and wherein (1) is carried out in hot water at 98° C. for 10 seconds The hot water shrinkage rate in the main shrinkage direction of the film during treatment is 40% or more and 80% or less, (2) Hot water in the direction perpendicular to the film main shrinkage direction when treated in hot water at 98°C for 10 seconds The shrinkage ratio is -5% or more and 10% or less, (3) the shrinkage stress ratio in the main shrinkage direction of the film measured under hot air at 90°C, the shrinkage stress ratio represented by the above formula is 0.6 or more and 1.0 or less, (4 ) The refractive index in the main shrinkage direction of the film is 1.600 or more. |