Heat-shrinking multilayer film and heat-shrinking label

A heat shrinkable multilayer film comprising:

• front and back layers each containing a polyester resin;
• an interlayer containing a polystyrene resin;
• and
• adhesive layers each containing a styrene-butadiene copolymer, which is a copolymer consisting of a component derived from styrene as an aromatic vinyl hydrocarbon and a component derived from 1,3-butadiene as a conjugated diene,
• wherein the front and back layers and the interlayer are stacked with the adhesive layers interposed therebetween,
• the heat shrinkable multilayer film has a maximum shrinkage stress of 3.5 to 11 MPa, which is measured by immersing in hot water at 80° C. for 30 seconds,
• the polystyrene resin constituting the interlayer is a mixed resin containing a styrene-butadiene copolymer (A) having a Vicat softening temperature of 80° C. or higher and a styrene-butadiene copolymer (B) having a Vicat softening temperature of lower than 80° C.,
• the interlayer contains 1 to 35% by weight of the styrene-butadiene copolymer (A) and 65 to 99% by weight of the styrene-butadiene copolymer (B),
• wherein the styrene-butadiene copolymer (A) and the styrene-butadiene copolymer (B) in the interlayer represents all of the polystyrene resin in the interlayer, and
• the styrene-butadiene copolymer constituting the adhesive layers has a higher butadiene content than all of the styrene-butadiene copolymers constituting the interlayer.