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US 5,707,750 AGranted
Retortable, high oxygen barrier polymeric films
AssigneeAlliedSignal Inc.
InventorsAlfieri Degrassi, James Ivan Fryer, Andrew Gerard Hitzel, Michael Stanley Matas
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Abstract
A polymeric film having superior oxygen barrier properties comprising at least five layers with two exterior layers independently selected from the group consisting of an aliphatic polyamide and an aliphatic/aromatic polyamide, an interior layer of ethylene vinyl alcohol copolymer or a blend of poly(m-xylylene adipamide) and ethylene vinyl alcohol copolymer, and a modified polyolefin adhesive layer between each exterior layer and the interior layer.
Claims23
A film having at least five layers comprised of:
- a) a first and second exterior layer independently comprised of a polymer selected from the group consisting of polyamides, aliphatic/aromatic polyamides having the formula ##STR3## and blends thereof, b) an interior layer which comprises a blend of an aliphatic/aromatic polyamide having the formula ##STR4## and an ethylene vinyl alcohol copolymer;
- and c) a modified polyolefin adhesive layer positioned between each exterior layer and the interior layer, wherein said film is retortable, and wherein R.sup.2 and R.sup.3 are different and are an alkylene group having at least 2 carbon atoms or an arylene group, with the proviso that when R.sup.2 is alkylene, R.sup.3 is arylene and when R.sup.2 is arylene, R.sup.3 is alkylene.
A process for producing a retortable film comprising:
- a) juxtaposing a modified polyolefin adhesive layer onto both sides of an interior layer comprised of a blend of an aliphatic/aromatic polyamide having the formula ##STR6## and an ethylene vinyl alcohol copolymer, to form a three-layered combination;
- b) juxtaposing a first and second exterior layer independently comprised of a polymer selected from the group consisting of aliphatic polyamides, aliphatic/aromatic polyamides having the formula ##STR7## and blends thereof, onto both sides of said three-layered combination, whereby said interior and exterior layers are bonded together through said adhesive layers, wherein R.sup.2 and R.sup.3 are different and are an alkylene group having at least 2 carbon atoms or an arylene group, with the proviso that when R.sup.2 is alkylene, R.sup.3 is arylene and when R.sup.2 is arylene, R.sup.3 is alkylene.
Dependencies are inferred from the claim text.