Metallocene-produced very low density polyethylenes
AssigneeExxonMobil Chemical Patents Inc.
InventorsJames M. Farley, Richard W. Halle, George Panagopoulos, Jerry M. Johnson, Douglas J. Laurent, Alan M. Malakoff
Life of this patent
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Abstract
A very low density polyethylene having a density of 0.890 to 0.915 and a Dart Drop value of at least about 450 g/mil or above is disclosed. Gas phase polymerization methods are also disclosed for making very low density linear polyolefins utilizing a metallocene catalyst, and the resulting polyolefin products. In a specific embodiment, a gas phase polymerization process is disclosed relating to the formation of a linear polyethylene having a very low density, e.g., ranging from 0.890 to 0.915, but with improved toughness.
Claims63
A polymer blend composition, comprising a copolymer derived from ethylene and one or more C3-C20 alpha olefin comonomers, said copolymer having:
- a) a comonomer content of from 5 to 15 wt. %,
- b) a density of less than 0.916 g/cm3,
- c) a composition distribution breadth index in the range of from 55% to 70%,
- d) a molecular weight distribution Mw/Mn of from 2 to 3,
- e) a molecular weight distribution Mz/Mw of less than 2, and
- f) a bi-modal composition distribution.
A monolayer film, comprising a copolymer derived from ethylene and one or more C3-C20 alpha olefin comonomers, said copolymer having:
- a) a comonomer content of from 5 to 15 wt. %,
- b) a density of less than 0.916 g/cm3,
- c) a composition distribution breadth index in the range of from 55% to 70%,
- d) a molecular weight distribution Mw/Mn of from 2 to 3,
- e) a molecular weight distribution Mz/Mw of less than 2, and
- f) a bi-modal composition distribution.
A multilayer film, comprising a first layer and a second layer, at least one of the layers comprising a copolymer derived from ethylene and one or more C3-C20 alpha olefin comonomers, said copolymer having:
- a) a comonomer content of from 5 to 15 wt. %,
- b) a density of less than 0.916 g/cm3,
- c) a composition distribution breadth index in the range of from 55% to 70%,
- d) a molecular weight distribution Mw/Mn of from 2 to 3,
- c) a molecular weight distribution Mz/Mw of less than 2, and
- f) a bi-modal composition distribution.
An article, comprising a substrate and a film disposed on the substrate, the film comprising a copolymer derived from ethylene and one or more C3-C20 alpha olefin comonomers, said copolymer having:
- a) a comonomer content of from 5 to 15 wt. %,
- b) a density of less than 0.916 g/cm3,
- c) a composition distribution breadth index in the range of from 55% to 70%,
- d) a molecular weight distribution Mw/Mn of from 2 to 3, and
- e) a molecular weight distribution Mz/Mw of less than 2;
- and
A polymer composition, comprising a metallocene-catalyzed linear VLDPE polymer, the VLDPE polymer having:
- (a) a density of less than 0.916 g/cm3,
- (b) a composition distribution breadth index of 50 to 85% by weight,
- (c) a molecular weight distribution Mw/Mn of 2.0 to 3.0,
- (d) a molecular weight distribution Mz/Mw of less than 2.0, and
- (e) two peaks in a TREF measurement.
A monolayer film comprising a polymer composition including a metallocene-catalyzed linear VLDPE polymer, the VLDPE polymer having:
- (a) a density of less than 0.916 g/cm3,
- (b) a composition distribution breadth index of 50 to 85% by weight,
- (c) a molecular weight distribution Mw/Mn of 2.0 to 3.0,
- (d) a molecular weight distribution Mz/Mw of less than 2.0, and
- (e) two peaks in a TREF measurement.
A multilayer film, comprising a first layer and a second layer, at least one of the layers comprising a metallocene-catalyzed linear VLDPE polymer, the VLDPE polymer having:
- (a) a density of less than 0.916 g/cm3,
- (b) a composition distribution breadth index of 50 to 85% by weight,
- (c) a molecular weight distribution Mw/Mn of 2.0 to 3.0,
- (d) a molecular weight distribution Mz/Mw of less than 2.0, and
- (e) two peaks in a TREF measurement.
An article, comprising a substrate and a film disposed on the substrate, the film comprising a metallocene-catalyzed linear VLDPE polymer, the VLDPE polymer having:
- (a) a density of less than 0.916 g/cm3,
- (b) a composition distribution breadth index of 50 to 85% by weight,
- (c) a molecular weight distribution Mw/Mn of 2.0 to 3.0, and
- (d) a molecular weight distribution Mz/Mw of less than 2.0.
A linear very low density polyethylene having a density of 0.910 to 0.915 and a Dart Drop value of at least about 450 g/mil or above.
A gas phase polymerization process for making a linear very low density polyethylene, comprising passing a gaseous stream containing one or more monomers through a fluidized bed under reactive conditions in the presence of a catalyst mixture comprising metallocene to provide a polyethylene having a density of 0.910 to 0.915.
Dependencies are inferred from the claim text.