Heat shrinkable multilayer film and heat shrinkable label
View Patent ↗It is an object of the present invention to provide a heat-shrinkable multilayer film which, in the case of using the heat-shrinkable multilayer film as a heat-shrinkable label for a container, does not produce delamination in covering a container, is superior in heat resistance, oil resistance, tearing properties along the perforation and appearance and can prevent the reduction in strength between the layers after a printing step, and a heat-shrinkable label comprising the heat-shrinkable multilayer film as a base film. The present invention is a heat-shrinkable multilayer film which comprises: an outer surface layer comprising a polyester type resin; and an intermediate layer comprising a polystyrene type resin, said outer surface layer and said intermediate layer being laminated by interposing an adhesive layer comprising a polyester type elastomer or a modified polyester type elastomer.
1. A heat-shrinkable multilayer film, comprising:
an outer surface layer comprising a polyester type resin; and
an intermediate layer comprising a polystyrene type resin,
said outer surface layer and said intermediate layer being laminated by interposing an adhesive layer consisting essentially of a polyester type elastomer,
wherein the polyester type elastomer composing the adhesive layer is a block copolymer comprising a polyester and polyalkylene ether glycol, and
wherein the polyester type resin composing the outer surface layer contains a component derived from terephthalic acid as a dicarboxylic acid component, and contains a component derived from ethylene glycol and a component derived from 1,4-cyclohexanedimethanol as a diol component.
2. The heat-shrinkable multilayer film according to claim 1 ,
wherein the polystyrene type resin composing the intermediate layer is an aromatic vinyl hydrocarbon-conjugated diene copolymer.
3. The heat-shrinkable multilayer film according to claim 2 ,
wherein the aromatic vinyl hydrocarbon-conjugated diene copolymer is a styrene-butadiene-styrene copolymer and/or a styrene-isoprene-butadiene-styrene copolymer.
4. The heat-shrinkable multilayer film according to claim 1 ,
wherein the polystyrene type resin composing the intermediate layer is a mixed resin of an aromatic vinyl hydrocarbon-conjugated diene copolymer and an aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer.
5. A heat-shrinkable label,
which is obtainable by using the heat-shrinkable multilayer film according to claim 1 .