Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 μm and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm.sup.3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

The polymerization process of this disclosure includes includes polymerizing ethylene and one or more olefins in the presence of a catalyst system under olefin polymerization conditions to form an ethylene-based polymer. The catalyst system comprising a metal-ligand complex according to formula (I):

##STR00001##

A polymer composition for producing gel extruded articles is described. The polymer composition contains polyethylene particles combined with a plasticizer. The polyethylene polymer has a narrow molecular weight distribution. Polymer articles made in accordance with the present disclosure have enhanced strength properties. In one embodiment, the polymer composition is used to form a porous membrane for use as a separator in electronic devices.

A polymer composition for producing gel extruded articles is described. The polymer composition contains polyethylene particles combined with a plasticizer. The polyethylene polymer has a narrow molecular weight distribution. Polymer articles made in accordance with the present disclosure have enhanced strength properties. In one embodiment, the polymer composition is used to form a porous membrane for use as a separator in electronic devices.

A catalyst composition for the polymerization of propylene is provided. The catalyst composition includes one or more Ziegler-Natta procatalyst compositions having one or more transition metal compounds and an internal electron donor, one or more aluminum containing cocatalysts, and a selectivity control agent (SCA). The SCA is a mixture of an activity limiting agent (ALA) and selectivity determining agent (SDA) such as a non-silane composition. The present catalyst composition is silane-free, has high catalyst activity and high stereoselectivity, and is self-extinguishing.

Disclosed are catalyst compositions having an internal electron donor which includes a 3,6-di-substituted-1,2-phenylene aromatic diester. Ziegler-Natta catalyst compositions containing the present catalyst compositions exhibit very high hydrogen response, high activity, high selectivity and produce propylene-based olefins with high melt flow rate.

This invention relates to transition metal complexes of a dianionic, tridentate ligand that features a central neutral heterocyclic Lewis base and two phenolate donors, where the tridentate ligand coordinates to the metal center to form two eight-membered rings. Preferably the bis(phenolate) complexes are represented by Formula (I): ##STR00001##
where M, L, X, m, n, E, E′, Q, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.1′, R.sup.2′, R.sup.3′, R.sup.4′, A.sup.1, A.sup.1′, ##STR00002##
are as defined herein, where A.sup.1QA.sup.1′ are part of a heterocyclic Lewis base containing 4 to 40 non-hydrogen atoms that links A.sup.2 to A.sup.2′ via a 3-atom bridge with Q being the central atom of the 3-atom bridge.

This invention relates to a supported catalyst system comprising: (i) at least one first catalyst component comprising a group 4 bis(phenolate) complex; (ii) at least one second catalyst component comprising a 2,6-bis(imino)pyridyl iron complex; (iii) activator; and (iv) support. The catalyst system may be used for preparing polyolefins, such a bimodal polyethylene, typically in a gas phase polymerization.

Embodiments are directed to a catalyst system comprising metal ligand complexes and processes for polyolefin polymerization using the metal ligand complex having the following structure: where X is selected from the group consisting of —OR.sup.X or NR.sup.X.sub.2. ##STR00001##

Provided is an olefin-based polymer with excellent processability. The olefin-based polymer according to the present invention has a high molecular weight and a broad molecular weight distribution to show excellent processability and improved transparency, thereby being used in desired applications.