Disclosed herein are ethylene-based polymers generally characterized by a density of at least 0.94 g/cm.sup.3, a high load melt index from 4 to 20 g/10 min, a zero-shear viscosity at 190° C. from 20,000 to 400,000 kPa-sec, and a relaxation time at 190° C. from 225 to 3000 sec. These ethylene polymers can be produced by peroxide-treating a broad molecular weight distribution Ziegler-catalyzed resin, and can be used in large diameter, thick wall pipes and other end-use applications.

Disclosed herein are ethylene-based polymers generally characterized by a density of at least 0.94 g/cm.sup.3, a high load melt index from 4 to 20 g/10 min, a zero-shear viscosity at 190° C. from 20,000 to 400,000 kPa-sec, and a relaxation time at 190° C. from 225 to 3000 sec. These ethylene polymers can be produced by peroxide-treating a broad molecular weight distribution Ziegler-catalyzed resin, and can be used in large diameter, thick wall pipes and other end-use applications.

This disclosure relates to ethylene interpolymer compositions and films prepared therefrom. Specifically: ethylene interpolymer products having: a dimensionless nonlinear rheology network parameter, Δ.sub.int., greater than or equal to 0.01, satisfying 0.01×(Z−50).sup.0.78≤Δ.sub.int.≤0.01×(Z−60).sup.0.78 inequality wherein Z is a normalized molecular weight defined by $Z=\frac{M_w}{M_e}$
where M.sub.w and M.sub.e are the weight average and entanglement molecular weights, and; a residual catalytic metal of from ≥0.03 to ≤5 ppm of hafnium. The disclosed ethylene interpolymer products have a melt index from about 0.3 to about 500 dg/minute, a density from about 0.855 to about 0.975 g/cc, a polydispersity, $\frac{M_w}{M_n},$
from about 1.7 to about 25 and a Composition Distribution Breadth Index (CDBI.sub.50) from about 1% to about 98%.

This disclosure relates to ethylene interpolymer compositions and films prepared therefrom. Specifically: ethylene interpolymer products having: a dimensionless nonlinear rheology network parameter, Δ.sub.int., greater than or equal to 0.01, satisfying 0.01×(Z−50).sup.0.78≤Δ.sub.int.≤0.01×(Z−60).sup.0.78 inequality wherein Z is a normalized molecular weight defined by $Z=\frac{M_w}{M_e}$
where M.sub.w and M.sub.e are the weight average and entanglement molecular weights, and; a residual catalytic metal of from ≥0.03 to ≤5 ppm of hafnium. The disclosed ethylene interpolymer products have a melt index from about 0.3 to about 500 dg/minute, a density from about 0.855 to about 0.975 g/cc, a polydispersity, $\frac{M_w}{M_n},$
from about 1.7 to about 25 and a Composition Distribution Breadth Index (CDBI.sub.50) from about 1% to about 98%.

The present invention is directed to a multimodal polyethylene copolymer comprising a first and a second copolymer of ethylene and at least two alpha-olefin comonomers. Such multimodal copolymers are highly suitable for conversion processes that require a high Draw Down Ratio, like the production of thin films. Such multimodal polyethylene copolymers provide a good impact strength in the sense of a high Dart drop impact strength (DDI) and good isotropy of the films produces thereof. The invention further presents final articles such as films made therefrom.

Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.

Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.

A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm.sup.3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from 12 to 40; 3) Mz from 500,000 to 3,500,000 g/mol; 4) η.sub.0.02 from 80,000 to 300,000 Pa.Math.s; 5) HMWcopo index from 1 to 15; and 6) Mz/Mw*LCBI lower than 6.4.

A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm.sup.3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from 12 to 40; 3) Mz from 500,000 to 3,500,000 g/mol; 4) η.sub.0.02 from 80,000 to 300,000 Pa.Math.s; 5) HMWcopo index from 1 to 15; and 6) Mz/Mw*LCBI lower than 6.4.

Processes for forming a polypropylene composition are provided herein comprising the steps of making a first propylene-based copolymer having a molecular weight distribution between 3 to 8.5, and making a second propylene-based polymer in the presence of the first propylene-based polymer to produce the polypropylene composition having a high molecular weight tail in the amount of between 1.0 wt. % and 10.0 wt. %. The polypropylene compositions produced have a broad molecular weight distribution and high molecular weight tail to provide improved stiffness while retaining toughness.