Films based on three component polyolefin blend
OwnerMark Thomas Demeuseinventor
Life of this patent
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Abstract
Polyolefin films having high oxygen transmission values are composed of blends of 75 to 92% isotactic polypropylene, 5 to 15% by weight low density polyethylene and 3 to 10% by weight of an olefin heteropolymer containing propylene and at least one other olefin 2 to 4 carbon atoms having a melting point less than that of polypropylene and a density ofr at least about 0.95 g/cc.
Claims13
A biaxially oriented film comprised of a polyolefin mixture consisting essentially of
- a) about 75 to 92% by weight of isotactic polypropylene,
- b) about 5 to 15% by weight of low density polyethylene having a density no greater than about 0.935 g/cc and
- c) about 3 to 10% by weight of an olefin heteropolymer containing propylene and at least one other 2 to 4 carbon α-olefin, said heteropolymer having a melting point less than that of polypropylene and a density no greater than about 0.95 g/cc.
A film according to claim 3 wherein the low density polyethylene has a density between about 0.915 and 0.935 g/cc.
A biaxially oriented film comprised of a polyolefin mixture consisting essentially of
- a) about 75 to 92% by weight of isotactic polypropylene,
- b) about 5 to 15% by weight of low density polyethylene having a density no greater than about 0.935 g/cc and
- c) about 3 to 10% by weight of an olefin heteropolymer containing propylene and at least one other α-olefin of 2 to 4 carbon atoms, said heteropolymer having a melting point less than that of polypropylene and a density no greater than about 0.95 g/cc, said film having an oxygen transmission rate of at least 200 cc/100 sq. In./day/atmosphere, a modulus of at least about 195,000 psi and a haze value no greater than about 4%.
Dependencies are inferred from the claim text.