| 摘要 |
The present invention addresses the problem of providing a heat-shrinkable polyester film, which has high thermal shrinkage in the width direction, exhibits small thermal shrinkage in the longitudinal direction, high mechanical strength in the longitudinal direction, favorable perforation opening properties and excellent shrink finishing properties. The heat-shrinkable polyester film satisfies the conditions (1) - (4) below. (1) The 98°C hot water thermal shrinkage in the main film shrinkage direction is 55% to 90%, (2) the 98°C hot water thermal shrinkage in the direction orthogonal to the main film shrinkage direction is -5% to 12%, (3) the change in specific heat capacity (?Cp) before and after Tg when reverse heat flow is measured with temperature-modulated DSC is 0.1 J/(g·°C) to 0.7 J/(g·°C), and (4) the tensile strength at break in the direction orthogonal to the main film shrinkage direction is 70 MPa to 150 MPa. |
