Polyethylene films
AssigneeExxonMobil Chemical Patents Inc.
InventorsEtienne R. H. Lernoux, Wen Li, Achiel J. M. Van Loon, Steven A. Best, Xiao-Chuan Wang
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Abstract
Films made from metallocene-catalyzed polyethylene polymers, optionally, with other polymers, are disclosed.
Claims20
A film made from at least one polyethylene polymer comprising from 75.0 mol % to 100.0 mol % ethylene derived units and having:
- a density of from 0.910 g/cm3 to 0.923 g/cm3,
- a melt index (I2.16) of from 0.1 g/10 min to 1.2 g/10 min,
- a melt index ratio (I21.6/I2.16) of from 20 to 35, and
- a weight average molecular weight (Mw) of from 150,000 g/mol to 400,000 g/mol;
- wherein the film has a dart drop impact strength (DIS) of ≥40 g/μm and flex crack resistance of ≤5 holes/10,000 cycles;
- and,
- wherein the film comprises two or more layers, wherein the two or more layers comprise at least one skin layer, a core layer, and optionally one or more intermediary layers;
- and, wherein at least one of the skin layer, the core layer, or optional intermediary layer comprises from 30 wt % to 100 wt % of the polyethylene polymer, based upon the total weight of the skin layer, the core layer, or optional intermediary layer;
- and,
- wherein at least one of the skin layer, the core layer, or optional intermediary layer, comprises a blend of the polyethylene polymer and at least one different polyethylene polymer, wherein the at least one different polyethylene polymer is a Ziegler-Natta linear low density polyethylene polymer.
A multilayer film comprising a core layer with a subskin layer located on each side of the core layer and a skin layer on the outer side of each subskin layer, where the core layer comprises i) from 50 wt % to 100 wt % of a first polyethylene polymer comprising from 75.0 mol % to 100.0 mol % ethylene derived units and having:
- a density of from 0.910 g/cm3 to 0.923 g/cm3,
- a melt index (I2.16) of from 0.1 g/10 min to 1.2 g/10 min,
- a melt index ratio (I21.6/I2.16) of from 20 to 35, and
- a weight average molecular weight (Mw) of from 150,000 g/mol to 400,000 g/mol;
- ii) a second polyethylene polymer comprising a Ziegler-Natta linear low density polyethylene polymer;
- the skin and subskin layers comprise i) from 50 wt % to 100 wt % of the first polyethylene polymer and ii) the second polyethylene polymer;
- wherein the wt % of first polyethylene polymer in the core layer is greater than or equal to the wt % of first polyethylene polymer in the skin and subskin layers;
- and
- wherein the film has a dart drop impact strength (DIS) of ≥40 g/μm and flex crack resistance of ≤5 holes/10,000 cycles.
Dependencies are inferred from the claim text.