Patent attributes
This invention relates to an in-reactor polymer blend comprising: (a) a first ethylene-containing polymer having a density of greater than 0.90 g/cm3 and a Mw of more than 20,000 g/mol and (b) a second ethylene-containing polymer having a density of less than 0.90 g/cm3, wherein the polymer blend has a Tm of at least 90° C. (DSC second melt), a density of less than 0.92 g/cm3, and the densities of the first and second polymers differ by at least 1%. Specifically this invention relates to an in-reactor polymer blend comprising: (a) a first ethylene polymer comprising 90 to 100 wt % ethylene and from 0 to less than 10 wt % comonomer, said first ethylene polymer component having density of greater than 0.920 g/cm3, an Mw of 20,000 g/mol or more; and (b) a second ethylene polymer comprising from 70 to 90 wt % ethylene and 30 to 10 wt % comonomer, said second ethylene polymer having a density of 0.910 g/cm3 or less, wherein the polymer blend has:(a) a Tm of at least 100° C. over a density ranging from 0.84 to 0.92 g/cm3;(b) a elongation at break of 300% or more;(c) a strain hardening index M300/M100 of at least 1.2;(d) a ratio of complex viscosity at 0.01 rad/s to the viscosity at 100 rad/s is of at least 30; and(e) a shear thinning slope of the plot of log(dynamic viscosity) versus log(frequency) less than −0.2.
