Patent ID: 6221410
Filing Date: 2001-04-24
Classification: A22C,B29C,B32B,B65D,F41A,Y10T

Abstract:
A backseamed casing comprising a heat-shrinkable casing film comprising:(A) a first outer layer serving as an inside casing layer, the first outer layer comprising a first polyolefin comprising at least one member selected from the group consisting of:(i) ethylene/unsaturated acid copolymer, propylene/unsaturated acid copolymer, and butene/unsaturated acid copolymer, wherein the unsaturated acid is present in an amount of at least 4 weight percent, based on the weight of the copolymer; and(ii) anhydride-containing polyolefin comprising an anhydride-functionality, wherein the anhydride functionality is present in an amount of at least 1 weight percent, based on the weight of the anhydride-containing polyolefin;(B) a second layer comprising at least one member selected from the group consisting of polyester, and first polyamide;(C) a third layer serving as an outside casing layer, the third layer comprising at least one member selected from the group consisting of second polyolefin, polystyrene, and second polyamide; and(D) a fourth layer which is an internal layer between the first layer and the third layer, the fourth layer serving as an O.sub.2 -barrier layer, the fourth layer comprising at least one member selected from the group consisting of ethylene/vinyl alcohol copolymer, polyvinylidene chloride, polyamide, polyalkylene carbonate, and polyester; andwherein the second layer is between the first layer and the third layer, and the second layer has a thickness of at least about 5% of a total thickness of the heat-shrinkable casing film.