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US 4,732,795 AGranted
Heat-shrinkable laminate tubular film
AssigneeKureha Kagaku Kogyo Kabushiki Kaisha
InventorsMasaki Ohya, Yoshiharu Nishimoto
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Abstract
Disclosed herein is a heat-shrinkable laminate tubular film comprising a gas-barrier layer of a copolymer of vinylidene chloride, outer layers of a polyolefin, at least one intermediate layer of a polyamide or a thermoplastic polyester both of which show a crystal melting point of not more than 240.degree. C. and have a specified thickness, and adhesive layers disposed between any of the above layers.
Claims10
A coextruded, biaxially stretched and laminated heat-shrinkable tubular film, comprising:
- a gas-barrier layer of a copolymer of vinylidene chloride having a thickness, which is not more than 30% of the total thickness of the coextruded, biaxially stretched and laminated heat-shrinkable tubular film, of not less than 6 .mu.m, outer layers of a polyolefin, at least one intermediate layer of a polyamide or a thermoplastic polyester, both of which show a crystal melting point of not more than 240.degree. C., said intermediate layer having a thickness of 5 to 40% of the total thickness of the coextruded, biaxially stretched and laminated heat-shrinkable tubular film, and adhesive layers disposed between all or certain polymer layers, and
- the total thickness of the coextruded, biaxially stretched and laminated heat-shrinkable tubular film being in the range of 20 to 120 micrometers,
- the coextruded, biaxially stretched and laminated heat-shrinkable tubular film being produced by laminating and co-extruding the copolymer of vinylidene chloride, the polyolefin, polyamide or the thermoplastic polyester and the adhesive material, cooling, heating and stretching the resultant laminated tubular film.
A coextruded, biaxially stretched and laminated heat-shrinkable tubular film, comprising:
- (A) a gas-barrier layer of a copolymer of vinylidene chloride having a thickness which is not more than 30% of the total thickness of the coextruded, biaxially stretched and laminated heat-shrinkable tubular film, of not less than 6 .mu.m;
- (B) outer layers which are of one of the following two combinations:
- (1) one outer layer consisting essentially of a copolymer of ethylene and vinyl acetate of a crystal melting point ranging from 80.degree. to 103.degree. C. and the other outer layer consisting essentially of a linear low-density polyethylene of a crystal melting point ranging from 110.degree. to 130.degree. C.,
- (2) both outer layers consisting essentially of a mixture of not more than 40% by weight of a linear low-density polyethylene of a crystal melting point ranging from 110.degree. to 130.degree. C. and not less than 60% by weight of a copolymer of ethylene and vinyl acetate of a crystal melting point ranging from 80.degree. to 103.degree. C., and
- (C) at least one intermediate layer of a polyamide or a thermoplastic polyester, both of which show a crystal melting point of not more than 240.degree. C., said intermediate layer having a thickness of 5 to 40% of the total thickness of the coextruded, biaxially stretched and laminated heat-shrinkable tubular film;
- and
- (D) adhesive layers which are disposed between all or certain polymer layers.
- the total thickness of the coextruded, biaxially stretched and laminated heat-shrinkable tubular film being in the range of 20 to 120 micrometers.
5 more elements
Dependencies are inferred from the claim text.