A process for preparing a polyethylene composition comprising contacting ethylene with a first salan catalyst precursor and an activator to form branched vinyl/vinylidene-terminated high density polyethylene having a number average molecular weight (Mn) of at least 5,000 g/mole; and contacting the branched vinyl/vinylidene-terminated high density polyethylene with ethylene and a second metallocene catalyst precursor and an activator to form a comb-block HDPE. The polyethylene composition comprises a polyethylene backbone, and one or more branched high density polyethylene combs pendant to the backbone, the combs having an Mn of at least 5,000 g/mole, where the polyethylene has a branching index (g′) of less than 0.9.

A process for preparing a polyethylene composition comprising contacting ethylene with a first salan catalyst precursor and an activator to form branched vinyl/vinylidene-terminated high density polyethylene having a number average molecular weight (Mn) of at least 5,000 g/mole; and contacting the branched vinyl/vinylidene-terminated high density polyethylene with ethylene and a second metallocene catalyst precursor and an activator to form a comb-block HDPE. The polyethylene composition comprises a polyethylene backbone, and one or more branched high density polyethylene combs pendant to the backbone, the combs having an Mn of at least 5,000 g/mole, where the polyethylene has a branching index (g′) of less than 0.9.

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.

The present disclosure provides pyridyl hydroxyl amine catalyst compounds and systems containing the compounds. The present disclosure is also directed to polymerization processes to produce polyolefin polymers from catalyst systems including one or more olefin polymerization catalysts, at least one activator, and an optional support. The compounds are represented by Formula I(a), I(b) or I(c):

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The present disclosure provides polymerization processes to produce polymeric materials, such as olefin terpolymers, using transition metal catalysts having bridged phenolate ligands. The polymerization process includes contacting a transition metal complex with a mixture olefin monomers that contain ethylene, propylene, and a cyclic diene to produce an olefin polymer and recovering the olefin polymer. The mixture of olefin monomers can include specified weight ratios for the various olefin monomers. The transition metal complex includes a bridged phenolate ligand bonded to a metal atom via covalent bonds by two oxygens, a coordinate covalent bond by a Group 15 atom, and a coordinate covalent bond by a Group 15 or 16 atom. The transition metal complex provides relatively high endocyclic alkene/vinyl selectivity to minimize hyperbranching during the production of olefin polymeric materials, such as EPDM and other terpolymers that are free or substantially free of gels.

This invention relates to transition metal complexes of a multi-dentate ligand that features a neutral heterocyclic Lewis base and a second Lewis base, where the multi-dentate ligand coordinates to the metal center to form at least one 8-membered chelate ring.

This invention relates to transition metal complexes of a multi-dentate ligand that features a neutral heterocyclic Lewis base and a second Lewis base, where the multi-dentate ligand coordinates to the metal center to form at least one 8-membered chelate ring.

The present disclosure provides pyridyl hydroxyl amine catalyst compounds and systems containing the compounds. The present disclosure is also directed to polymerization processes to produce polyolefin polymers from catalyst systems including one or more olefin polymerization catalysts, at least one activator, and an optional support. The compounds are represented by Formula I(a), I(b) or I(c): ##STR00001##

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.