Elastic substantialy linear olefin polymers
AssigneeThe Dow Chemical Company
InventorsShih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens
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Abstract
Elastic substantially linear olefin polymers are disclosed which have very good processability, including processing indices (PI's) less than or equal to 70 percent of those of a comparative linear olefin polymer and a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a traditional linear olefin polymer at about the same I.sub.2 and M.sub.w /M.sub.n. The novel polymers have higher low/zero shear viscosity and lower high shear viscosity than comparative linear olefin polymers.
Claims37
A substantially linear olefin polymer characterized as having:
- a) a melt flow ratio, I.sub.10 /I.sub.2,.gtoreq.5.63,
- b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation:
- M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63, and
- c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having about the same I.sub.2 and M.sub.w /M.sub.n, and wherein the olefin polymer is further characterized as a copolymer of ethylene with a C.sub.3 -C.sub.20 alpha-olefin.
A composition comprising a substantially linear olefin polymer, wherein the polymer is characterized as having:
- a) a melt flow ratio, I.sub.10 /I.sub.2,.gtoreq.5.63,
- b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation:
- M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63, and
- c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having about the same I.sub.2 and M.sub.w /M.sub.n, and wherein the olefin polymer is further characterized as a copolymer of ethylene with a C.sub.3 -C.sub.20 alpha-olefin and (b) at least one other natural or synthetic polymer.
A substantially linear olefin polymer characterized as a copolymer of ethylene with a C.sub.3 -C.sub.20 alpha-olefin and having:
- a) a melt flow ratio, I.sub.10 /I.sub.2,.gtoreq.5.63,
- b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation:
- M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63, and
- c) a processing index (PI) less than or equal to about 70% of the PI of a comparative linear olefin polymer at about the same I.sub.2 and M.sub.w /M.sub.n.
A film layer comprising a substantially linear olefin polymer, wherein the substantially linear olefin polymer is characterized as having:
- a) a melt flow ratio, I.sub.10 /I.sub.2,.gtoreq.5.63,
- b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation:
- M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63, and
- c) a critical shear rate at onset of surface melt fracture at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having about the same I.sub.2 and M.sub.w /M.sub.n, and wherein the olefin polymer is further characterized as a copolymer of ethylene with a C.sub.3 -C.sub.20 alpha-olefin.
A film layer composition comprising a substantially linear olefin polymer, wherein the substantially linear olefin polymer is characterized as having:
- a) a melt flow ratio, I.sub.10 /I.sub.2,.gtoreq.5.63,
- b) a molecular weight distribution, M.sub.w /M.sub.n, of from 1.5 to 2.5, and
- c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer at about the same I.sub.2 and M.sub.w /M.sub.n, and wherein the olefin polymer is further characterized as a copolymer of ethylene with a C.sub.3 -C.sub.20 alpha-olefin.
Dependencies are inferred from the claim text.