Catalyst systems and methods for making and using the same. A method of polymerizing olefins to produce a polyolefin polymer with a multimodal composition distribution, includes contacting ethylene and a comonomer with a catalyst system. The catalyst system includes a first catalyst compound and a second catalyst compound that are co-supported to form a commonly supported catalyst system. The first catalyst compound includes a compound with the general formula (C.sub.5H.sub.aR.sup.1.sub.b)(C.sub.5H.sub.cR.sup.2.sub.d)HfX.sub.2. The second catalyst compound includes at least one of the following general formulas:

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In both catalyst systems, the R groups can be independently selected from any number of substituents, including, for example, H, a hydrocarbyl group, a substituted hydrocarbyl group, or a heteroatom group, among others.

Disclosed is a propylene-diene copolymer resin having excellent melt tension, with improved melt strength, high molecular weight and broad molecular weight distribution by using a specific metallocene catalyst system. The present invention provides a propylene-diene copolymer resin produced by polymerizing propylene and a diene compound of C4-C20 by using a metallocene catalyst system, wherein the propylene-diene copolymer resin has the melt index (2.16 kg load at 230 C.) of 0.1-100 g/10 min and the melt tension (advanced rheometric expansion system (ARES)) of 5-100 g.

Disclosed is a propylene-diene copolymer resin having excellent melt tension, with improved melt strength, high molecular weight and broad molecular weight distribution by using a specific metallocene catalyst system. The present invention provides a propylene-diene copolymer resin produced by polymerizing propylene and a diene compound of C4-C20 by using a metallocene catalyst system, wherein the propylene-diene copolymer resin has the melt index (2.16 kg load at 230 C.) of 0.1-100 g/10 min and the melt tension (advanced rheometric expansion system (ARES)) of 5-100 g.

An ethylene/1-hexene copolymer has a density from 0.9541 to 0.9600 gram per cubic centimeter (g/cm.sup.3), a molecular mass dispersity (.sub.M=M.sub.w/M.sub.n) from greater than 2.0 to 3.5; and a Z-average molecular weight (Mz) from 120,000 to 240,000 grams per mole (g/mol). Methods of making and using same. Articles containing same.

An ethylene/1-hexene copolymer has a density from 0.9541 to 0.9600 gram per cubic centimeter (g/cm.sup.3), a molecular mass dispersity (.sub.M=M.sub.w/M.sub.n) from greater than 2.0 to 3.5; and a Z-average molecular weight (Mz) from 120,000 to 240,000 grams per mole (g/mol). Methods of making and using same. Articles containing same.

The present invention relates to an ethylene/alpha-olefin copolymer and, more particularly, to an ethylene/alpha-olefin copolymer that exhibits excellent environmental stress crack resistance by appropriately controlling the ratio of crystal structure domain and amorphous domain, and the like. The ethylene/alpha-olefin copolymer comprises an ethylene repeating unit and an alpha-olefin repeating unit, and has a crystal structure including a crystalline domain containing lamellar crystals and an amorphous domain containing a tie molecule that mediates bonding between the lamellar crystals. The lamellar crystal thickness (dc) of the ethylene/alpha-olefin copolymer as calculated from the result of Small Angle X-ray Scattering (SAXS) analysis is between 12.0 and 16.0 nm, the amorphous domain thickness (da) is between 4.0 and 5.3 nm, and the thickness ratio da/dc is between 0.3 and 0.4.

The present invention relates to an ethylene/alpha-olefin copolymer and, more particularly, to an ethylene/alpha-olefin copolymer that exhibits excellent environmental stress crack resistance by appropriately controlling the ratio of crystal structure domain and amorphous domain, and the like. The ethylene/alpha-olefin copolymer comprises an ethylene repeating unit and an alpha-olefin repeating unit, and has a crystal structure including a crystalline domain containing lamellar crystals and an amorphous domain containing a tie molecule that mediates bonding between the lamellar crystals. The lamellar crystal thickness (dc) of the ethylene/alpha-olefin copolymer as calculated from the result of Small Angle X-ray Scattering (SAXS) analysis is between 12.0 and 16.0 nm, the amorphous domain thickness (da) is between 4.0 and 5.3 nm, and the thickness ratio da/dc is between 0.3 and 0.4.

The instant invention is a high-density polyethylene composition, method of producing the same, injection molded articles made therefrom, and method of making such articles. The high-density polyethylene composition of the instant invention includes a first component, and a second component. The first component is a high molecular weight ethylene alpha-olefin copolymer having a density in the range of 0.920 to 0.946 g/cm.sup.3, and a melt index (I.sub.21.6) in the range of 1 to 15 g/10 minutes. The second component is a low molecular weight ethylene polymer having a density in the range of 0.965 to 0.980 g/cm.sup.3, and a melt index (I.sub.2) in the range of 30 to 1500 g/10 minutes. The high-density polyethylene composition has a melt index (I.sub.2) of at least 1, a density in the range of 0.950 to 0.960 g/cm.sup.3.

The instant invention is a high-density polyethylene composition, method of producing the same, injection molded articles made therefrom, and method of making such articles. The high-density polyethylene composition of the instant invention includes a first component, and a second component. The first component is a high molecular weight ethylene alpha-olefin copolymer having a density in the range of 0.920 to 0.946 g/cm.sup.3, and a melt index (I.sub.21.6) in the range of 1 to 15 g/10 minutes. The second component is a low molecular weight ethylene polymer having a density in the range of 0.965 to 0.980 g/cm.sup.3, and a melt index (I.sub.2) in the range of 30 to 1500 g/10 minutes. The high-density polyethylene composition has a melt index (I.sub.2) of at least 1, a density in the range of 0.950 to 0.960 g/cm.sup.3.

A catalyst composition and a method for preparing an olefin polymer by using the same are provided herein. In some embodiments, a catalyst composition includes a transition metal compound having a compound (A) represented by Chemical Formula 1 and a compound (B) represented by Chemical Formula 2 present in a molar ratio of 1.6:1 to 18. The catalyst composition has high activity in an olefin polymerization reaction and can contribute to a reduction of catalyst cost. The catalyst composition aides in high copolymerizability of olefin monomers, and the produced olefin polymers can exhibit excellent processability and long-term physical properties, suitable for a pipe.