Cast Polyethylene Packaging Films
OwnerGiriprasath GURURAJAN, Michael A. LEAF +1inventors
InventorsGiriprasath GURURAJAN, Michael A. LEAF, Porter C. SHANNON
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Abstract
A cast film is made from at least one ethylene polymer which comprises from 75.0 mol % to 100.0 mol % of ethylene derived units and which has a density of from 0.900 g/cm3 to 0.926 g/cm3, a melt index (I2.16) from greater than 1.2 g/10 min to 6 g/10 min, a melt index ratio (I21.6/I2.16) of from 20 to 50, and a z-average molecular weight (Mz) of greater 150,000 g/mol. The cast film has an average flex crack resistance as measured by ASTM F392 of less than or equal to 15 holes/300 cm2 after 10,000 cycles, preferably 8±1 holes/300 cm2 after 10,000 cycles.
Claims14
A cast film made from at least one ethylene polymer comprising from 75.0 mol % to 100.0 mol % of ethylene derived units and having:
- a density of from 0.900 g/cm3 to 0.926 g/cm3,
- a melt index (I2.16) from 1.2 g/10 min to 6 g/10 min,
- a melt index ratio (I21.6/I2.16) of from 20 to 50, and
- a z-average molecular weight (Mz) of greater 150,000 g/mol.
- wherein the cast film has an average flex crack resistance as measured by ASTM F392 of less than 15 holes/300 cm2 after 10,000 cycles.
A process for producing a film, the process comprising:
- (1) polymerizing ethylene in the presence of a metallocene catalyst system in a gas phase reactor with at least one C3 to C10 alpha-olefin comonomer to produce a polyethylene composition having a density between about 0.900 g/cm3 and about 0.926 g/cm3, a melt index (I2.16) from 2 g/10 min to 6 g/10 min, a melt index ratio (I21.6/I2.16) of from 20 to 50, and a Mz greater than 150,000 g/mol;
- and
- (2) casting the polyethylene composition into a film having an average flex crack resistance as measured by ASTM F392 of less than 15 holes/300 cm2 after 10,000 cycles.
Dependencies are inferred from the claim text.