Ethylene polymer blends and process for forming film
AssigneePhillips Petroleum Company
InventorsFay W. Bailey, William M. Whitte
Life of this patent
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Abstract
Ethylene polymer blends of a high molecular weight ethylene polymer, preferably an ethylene-mono-1-olefin copolymer, and a low molecular weight ethylene polymer preferably an ethylene homopolymer, both preferably with narrow molecular weight distribution and low levels of long chain branching exhibit excellent film properties and good environmental stress crack behavior superior to that expected for polyethylene of comparable density and melt flow. These resins are useful for the manufacture of film or in blow molding techniques, the production of pipes and wire coating.
Claims11
Process to produce an ethylene polymer film comprising extruding a fluid ethylene polymer blend, the polymer component of which consists essentially of
- (a) 40-70 parts by weight of a high molecular weight ethylene polymer having a high load melt index (HLMI) in the range of about 0.1 to about 1.5 g/10 min and a density in the range of 0.930 to 0.940 g/cc, and having a heterogeneity index of <10, and
- (b) 60-30 parts by weight of a low molecular weight ethylene polymer having a melt index (MI) in the range of 45-300 g/10 minutes and a density of above about 0.950 and having a heterogeneity index of <6.
Process to produce an ethylene polymer film comprising extruding a fluid ethylene polymer blend, the polymer component of which consists essentially of
- (a) 40-70 parts by weight of a high molecular weight ethylene copolymer having a high load melt index (HLMI) in the range of 0.2-0.6 g/10 min and a density in the range of 0.930 to 0.940 g/cc, and having a heterogeneity index of <10, and
- (b) 60-30 parts by weight of a low molecular weight ethylene homopolymer having a melt index (MI) in the range of 100-300 g/10 minutes and a density of above about 0.950 and having a heterogeneity index of <6 wherein the low molecular weight ethylene homopolymer is essentially linear and wherein the high molecular weight ethylene copolymer is also essentially linear and has essentially only short chain branching from the comonomer.
Dependencies are inferred from the claim text.