High melt strength polyethylene compositions
AssigneeExxon Chemical Patents Inc.
InventorsEric J. Markel, Carlos U. DeGracia, Armen H. Dekmezian
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Abstract
The invention is a polyethylene composition having a polydispersity index of less than or equal to 3, an average branching index (g') as measured by GPC/Vis.gtoreq.0.9, and a melt strength (MS) (centiNewton, 190.degree. C.) that satisfies the relationship: ##EQU1## In a preferred embodiment these polyethylene compositions comprise A) branched polyethylene copolymers prepared by insertion polymerization of ethylene, ethylene-containing macromers, and optionally, additional copolymerizable monomers, and B) essentially linear ethylene copolymers. Improved melt strength without sacrificing the benefits of narrow polydispersity index are exhibited by the invention compositions.
Claims9
A polyethylene composition having a polydispersity index of less than or equal to 3, an average branching index (g') as measured by gel permeation chromotography/viscosity (GPC/Vis).gtoreq.0.9, and a melt strength (MS) (centiNewton, 190.degree. C.) that satisfies the relationship:
- ##EQU3## wherein said composition comprises a branched polyethylene copolymer prepared by insertion polymerization of ethylene, ethylene-containing macromers, and optionally, additional copolymerizable monomers, and an essentially linear ethylene copolymer having density of 0.900-0.935 g/cm.sup.3, polydispersity index of 1.8-3.5 and a melt index (2.16 kg/190.degree. C.) of 0.3-7.5.
Dependencies are inferred from the claim text.