| 摘要 |
A film comprising a blend of copolymers, which has been (i) extruded to a gauge in the range of about 0.3 to about 0.9 mil, said film having an Elmendorf Tear Strength in the machine direction of at least about 25 grams per mil greater than the Elmendorf Tear Strength in the machine direction of the same blend of copolymers, which has been extruded to a gauge of one mil, or (ii) extruded to a heavy gauge of at least about 4.5 mils and then biaxially oriented and reduced to a gauge of about 1.5 mils or less, first in the machine direction at a gauge reduction ratio of at least about 2:1, and then in the transverse direction at a gauge reduction ratio of at least about 1.5:1, said blend having been produced in situ by contacting ethylene and at least one alpha-olefin comonomer with a magnesium/titanium based catalyst system in each of two reactors connected in series, under polymerization conditions.
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