Polyester-based shrink film

A heat-shrinkable polyester film derived from a polyester resin composition containing 30% to 90% by weight of an amorphous polyester resin and 10% to 70% by weight of a crystalline polyester resin with respect to a total amount (100% by weight), the heat-shrinkable polyester film satisfying the following configurations (a′) to (c′):

• configuration (a′):
• a storage modulus curve obtained using a dynamic viscoelasticity measuring apparatus according to JIS K 7244-4 has a first deflection point at which a storage modulus decreases, in a temperature region of below 100° C.;
• configuration (b′):
• a storage modulus curve obtained using a dynamic viscoelasticity measuring apparatus according to JIS K 7244-4 has a second deflection point at which a storage modulus increases, in a temperature region of 100° C. or higher;
• and
• configuration (c′):
• a heat shrinkage ratio in a main shrinkage direction obtained when the film is immersed in hot water at 80° C. for 10 seconds is 30% or more.

A heat-shrinkable polyester film derived from a polyester resin composition containing 30% to 90% by weight of an amorphous polyester resin and 10% to 70% by weight of a crystalline polyester resin with respect to a total amount (100% by weight), the heat-shrinkable polyester film satisfying the following configurations (a″) to (c″):

• configuration (a″):
• a loss modulus curve obtained using a dynamic viscoelasticity measuring apparatus according to JIS K 7244-4 has a first loss modulus peak in a temperature region of below 100° C.;
• configuration (b″):
• a loss modulus curve obtained using a dynamic viscoelasticity measuring apparatus according to JIS K 7244-4 has a second loss modulus peak that is convex-shaped in a direction inverse to the first loss modulus peak, in a temperature region of 100° C. or higher;
• and
• configuration (c″):
• a heat shrinkage ratio in a main shrinkage direction obtained when the film is immersed in hot water at 80° C. for 10 seconds is 30% or more.