| 摘要 |
A method of preparing a composition, comprising a blend, wherein said blend comprises a high molecular weight ethylene-based interpolymer and a low molecular weight ethylene-based interpolymer, said method comprising:
a) polymerizing either the high molecular weight ethylene-based interpolymer, or the low molecular weight ethylene-based interpolymer, in a first reactor, in the presence of a Ziegler-Natta catalyst system, to form a first interpolymer product;
b) transferring the first interpolymer product to another reactor; and
c) polymerizing, in the other reactor, the ethylene-based interpolymer that was not produced in the first reactor, in the presence of the Ziegler-Natta catalyst system; and
wherein the high molecular weight ethylene-based interpolymer is a heterogeneously branched linear ethylene-based interpolymer, and has a density from 0.922 g/cc to 0.929 g/cc, and a high load melt index (I21) from 0.2 g/10 min to 1.0 g/10 min, and
wherein the low molecular weight ethylene-based interpolymer is heterogeneously branched linear ethylene-based interpolymer, and has a density from 0.940 g/cc to 0.955 g/cc, and a melt index (I2) from 6 g/10 min to 50 g/10 min; and
wherein the blend has a single peak in an ATREF profile eluting above 30°C, and has a coefficient of viscosity average molecular weight (CMv) less than -0.0032 in the log(calculated Mv) versus elution temperature, said CMv calculated in the range of elution temperatures from 70°C to 90°C, and wherein Mv is the viscosity average molecular weight. |
