Linear low-density polyethylene polymers used to form covering layers for cables are disclosed. Such polymers exhibit certain molecular weight distributions suitable to form the covering layers for the cable. The polymer can be crosslinked to exhibit suitable properties including retained elongation at break values and hot set values.

Ethylene-based polymers are characterized by a melt index less than 1 g/10 min, a density from 0.94 to 0.965 g/cm.sup.3, a Mw from 100,000 to 250,000 g/mol, a relaxation time from 0.5 to 3 sec, and an average number of long chain branches (LCBs) per 1,000,000 total carbon atoms in a molecular weight range of 300,000 to 900,000 g/mol that is greater than that in a molecular weight range of 1,000,000 to 2,000,000 g/mol, or an average number of LCBs per 1,000,000 total carbon atoms in a molecular weight range of 1,000,000 to 2,000,000 g/mol of less than or equal to about 5 and a maximum ratio of η.sub.E/3η at an extensional rate of 0.1 sec.sup.−1 from 1.2 to 10. These polymers have substantially no long chain branching in the high molecular weight fraction of the polymer, but instead have significant long chain branching in a lower molecular weight fraction, such that polymer melt strength and parison stability are maintained for the fabrication of blow molded products and other articles of manufacture. These ethylene polymers can be produced using a dual catalyst system containing a single or two atom bridged metallocene compound with two indenyl groups, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

Ethylene-based polymers are characterized by a melt index less than 1 g/10 min, a density from 0.94 to 0.965 g/cm.sup.3, a Mw from 100,000 to 250,000 g/mol, a relaxation time from 0.5 to 3 sec, and an average number of long chain branches (LCBs) per 1,000,000 total carbon atoms in a molecular weight range of 300,000 to 900,000 g/mol that is greater than that in a molecular weight range of 1,000,000 to 2,000,000 g/mol, or an average number of LCBs per 1,000,000 total carbon atoms in a molecular weight range of 1,000,000 to 2,000,000 g/mol of less than or equal to about 5 and a maximum ratio of η.sub.E/3η at an extensional rate of 0.1 sec.sup.−1 from 1.2 to 10. These polymers have substantially no long chain branching in the high molecular weight fraction of the polymer, but instead have significant long chain branching in a lower molecular weight fraction, such that polymer melt strength and parison stability are maintained for the fabrication of blow molded products and other articles of manufacture. These ethylene polymers can be produced using a dual catalyst system containing a single or two atom bridged metallocene compound with two indenyl groups, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

What is disclosed is a Ziegler-Natta catalyzed ethylene and alpha-olefin LLDPE copolymer having a unique composition distribution and long chain-branching. The polymers of the present invention inherently exhibit outstanding melt strength with great bubble stability, sufficient flexibility, excellent gel performance, as well as desirable mechanical properties such as balanced toughness and stiffness, which are desirable properties for thick gauge film applications. Specifically, the polymers of the present invention.

What is disclosed is a Ziegler-Natta catalyzed ethylene and alpha-olefin LLDPE copolymer having a unique composition distribution and long chain-branching. The polymers of the present invention inherently exhibit outstanding melt strength with great bubble stability, sufficient flexibility, excellent gel performance, as well as desirable mechanical properties such as balanced toughness and stiffness, which are desirable properties for thick gauge film applications. Specifically, the polymers of the present invention.

This invention relates to a catalyst system including the reaction product of a support (such as a fluorided silica support that preferably has not been calcined at a temperature of 400° C. or more), an activator and at least two different transition metal catalyst compounds; methods of making such catalyst systems, polymerization processes using such catalyst systems and polymers made therefrom.

This invention relates to a catalyst system including the reaction product of a support (such as a fluorided silica support that preferably has not been calcined at a temperature of 400° C. or more), an activator and at least two different transition metal catalyst compounds; methods of making such catalyst systems, polymerization processes using such catalyst systems and polymers made therefrom.

A bimodal poly(ethylene-co-1-alkene) copolymer comprising a higher molecular weight poly(ethylene-co-1-alkene) copolymer component and a lower molecular weight poly(ethylene-co-1-alkene) copolymer component. The copolymer is characterized by a unique combination of features comprising, or reflected in, its density; molecular weight distributions; component weight fraction amount; viscoelastic properties; and environmental stress-cracking resistance. Additional inventive embodiments include a method of making the copolymer, a formulation comprising the copolymer and at least one additive that is different than the copolymer, a method of making a manufactured article from the copolymer or formulation; the manufactured article made thereby, and use of the manufactured article.

A bimodal poly(ethylene-co-1-alkene) copolymer comprising a higher molecular weight poly(ethylene-co-1-alkene) copolymer component and a lower molecular weight poly(ethylene-co-1-alkene) copolymer component. The copolymer is characterized by a unique combination of features comprising, or reflected in, its density; molecular weight distributions; component weight fraction amount; viscoelastic properties; and environmental stress-cracking resistance. Additional inventive embodiments include a method of making the copolymer, a formulation comprising the copolymer and at least one additive that is different than the copolymer, a method of making a manufactured article from the copolymer or formulation; the manufactured article made thereby, and use of the manufactured article.

A dual reactor solution process gives high density polyethylene compositions containing a first ethylene copolymer and a second ethylene copolymer and which have good processability, stiffness, and environmental stress crack resistance. The polyethylene compositions are suitable for compression molding or injection molding applications and are particularly useful in the manufacture of caps and closures for bottles.