A transition metal compound represented by Chemical Formula 1 and a method for preparing the same, catalyst compositions including the same, and olefin-based polymers prepared from the same are disclosed herein. The transition metal catalyst has excellent structural stability together with excellent catalytic activity and can exhibit excellent copolymerizability even at a high temperature. In an embodiment, an olefin-based polymer prepared using a catalyst composition including the transition metal compound has a density of 0.91 g/cc or less.

A transition metal compound represented by Chemical Formula 1 and a method for preparing the same, catalyst compositions including the same, and olefin-based polymers prepared from the same are disclosed herein. The transition metal catalyst has excellent structural stability together with excellent catalytic activity and can exhibit excellent copolymerizability even at a high temperature. In an embodiment, an olefin-based polymer prepared using a catalyst composition including the transition metal compound has a density of 0.91 g/cc or less.

The present invention relates to a polyethylene copolymer which has excellent processability and long-term durability, and thus is useful for hollow molding of a pipe or the like.

This invention relates to supported catalyst compositions of 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′, A.sup.3A.sup.2, and A.sup.2′A.sup.3′ 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.

The invention relates to a propylene copolymer composition comprising a propylene-ethylene copolymer, wherein the propylene-ethylene copolymer has a melt flow index in the range of 0.05 to 2.5 dg/min measured according to ISO1133 (2.16 kg/230° C.), wherein the propylene-ethylene copolymer is a unimodal propylene-ethylene copolymer and wherein a pipe prepared from the propylene copolymer composition according to ISO 1167-2 has a run time without failure of at least 2,500 h measured according to ISO1167-1 at a temperature of 95° C. and a hoop stress calculated according to ISO3213 of 4.2 MPa.

The invention relates to a propylene copolymer composition comprising a propylene-ethylene copolymer, wherein the propylene-ethylene copolymer has a melt flow index in the range of 0.05 to 2.5 dg/min measured according to ISO1133 (2.16 kg/230° C.), wherein the propylene-ethylene copolymer is a unimodal propylene-ethylene copolymer and wherein a pipe prepared from the propylene copolymer composition according to ISO 1167-2 has a run time without failure of at least 2,500 h measured according to ISO1167-1 at a temperature of 95° C. and a hoop stress calculated according to ISO3213 of 4.2 MPa.

Catalyst systems contain metal-ligand complexes according to formula (I): In formula (I), M is Ti, Zr, of Hf; n is 0, 1, 2, or 3; m is 1 or 2; each R.sup.1 and each R.sup.2 is independently chosen from (C.sub.1-C.sub.40)hydrocarbyl, (C.sub.1-C.sub.40)heterohydrocarbyl, (C.sub.1-C.sub.40)aryl, (C.sub.1-C.sub.40)heteroaryl, halogen, and —H; R.sup.1 and R.sup.2 are optionally covalently linked to each other; and each R.sup.3 is a hydrocarbon or heterohydrocarbon radical having an identity depending on the value of subscript m. The metal-ligand complexes may be incorporated as procatalysts in catalyst systems for polyolefin polymerization. ##STR00001##

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.

Embodiments of the present application are directed to procatalysts, and catalyst systems including procatalysts, including a metal-ligand complex having the structure of formula (I): [Formula I]

A transition metal compound having a novel structure is disclosed herein. The transition metal compound can have improved structural stability by forming a stable coordination site of a transition metal through controlling a bond angle formed by the amido group of a phenylene bridge, a cyclopentadienyl ring, and a transition metal. The transition metal compound has excellent copolymerization properties and may produce an olefin polymer having a high molecular weight in a ultra low density region.