Thermo-shrinkable polyester film

摘要

In a thermo-shrinkable polyester film, the thermal shrinkage ratio in a main shrinking direction is about 20% or more after being treated in water of about 70 DEG C for about 5 seconds, about 35 to about 55% after treated in water of about 75 DEG C for about 5 seconds, and about 50 to about 60% after being treated in water of about 80 DEG C for about 5 seconds. After the film is shrunk by about 5% by treatment in water of about 75 DEG C for about 10 seconds, the probability of the elongation at rupture of the film in the direction perpendicular to the main shrinking direction being about 20% or less, is about 10% or less. The ratio of tau 1/ tau 2 is about 0.05 to about 0.45, where tau 2 is the stress of shrinkage in a main shrinking direction of the film at about 90 DEG C, and tau 1 is the stress of shrinkage in a direction perpendicular to the main shrinking direction of the film at about 90 DEG C. The sealing strength of the film is about 1.2 kg/15 mm of width or more.