Higher density polyolefins with improved stress crack resistance
AssigneeChevron Phillips Chemical Company LP
InventorsMark L. Hlavinka, Errun Ding, Paul DesLauriers, Yongwoo Inn, Lili Cui, Qing Yang, Ashish Sukhadia, Guylaine St. Jean, Richard M. Buck
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Abstract
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes can employ a catalyst system containing two or three metallocene components, resulting in ethylene-based copolymers that can have a medium density and improved stress crack resistance.
Claims20
An ethylene polymer having a density from about 0.930 to about 0.948 g/cm3, a zero-shear viscosity greater than about 5×105 Pa-sec, a CY-a parameter in a range from about 0.01 to about 0.40, a peak molecular weight (Mp) in a range from about 30,000 to about 130,000 g/mol, a bimodal molecular weight distribution, and a reverse comonomer distribution.
An ethylene polymer having a density from about 0.930 to about 0.948 g/cm3, a bimodal molecular weight distribution, a single point notched constant tensile load (SP-NCTL) of at least 6,500 hours, and a natural draw ratio (NDR) of less than or equal to about 525%.
Dependencies are inferred from the claim text.