A process for the preparation of an ultra-high molecular weight ethylene homopolymer having a MFR.sub.21 of 0.01 g/10 min or less, said process comprising: (I) prepolymerising at least ethylene at a temperature of 0 to 90° C. in the presence of a heterogeneous Ziegler Natta catalyst to prepare an ethylene prepolymer having an Mw of 40,000 to 600,000 g/mol; and thereafter in the presence of the prepolymer and said catalyst; (II) polymerising ethylene at a temperature of 55° C. or less, such as 20 to 55° C., to prepare said UHMW ethylene homopolymer; wherein the UHMW ethylene homopolymer comprises up to 8 wt. % of said prepolymer.

Embodiments of a method for producing a multimodal ethylene-based polymer having a first, second, and third ethylene-based component, wherein the multimodal ethylene based polymer results when ethylene monomer, at least one C.sub.3-C.sub.12 comonomer, solvent, and optionally hydrogen pass through a first solution, and subsequently, a second solution polymerization reactor. The first solution polymerization reactor or the second solution polymerization reactor receives both a first catalyst and a second catalyst, and a third catalyst passes through either the first or second solution polymerization reactors where the first and second catalysts are not already present. Each ethylene-based component is a polymerized reaction product of ethylene monomer and C.sub.3-C.sub.12 comonomer catalyzed by one of the three catalysts.

Embodiments of a method for producing a multimodal ethylene-based polymer having a first, second, and third ethylene-based component, wherein the multimodal ethylene based polymer results when ethylene monomer, at least one C.sub.3-C.sub.12 comonomer, solvent, and optionally hydrogen pass through a first solution, and subsequently, a second solution polymerization reactor. The first solution polymerization reactor or the second solution polymerization reactor receives both a first catalyst and a second catalyst, and a third catalyst passes through either the first or second solution polymerization reactors where the first and second catalysts are not already present. Each ethylene-based component is a polymerized reaction product of ethylene monomer and C.sub.3-C.sub.12 comonomer catalyzed by one of the three catalysts.

Embodiments of a method of producing a multimodal ethylene-based polymer comprising a first catalyst and a second catalyst in a first solution polymerization reactor and a third catalyst in a second solution polymerization reactor.

Embodiments of a method of producing a multimodal ethylene-based polymer comprising a first catalyst and a second catalyst in a first solution polymerization reactor and a third catalyst in a second solution polymerization reactor.

Disclosed are a polyolefin resin composition and a production method using same. The polyolefin resin satisfies the following conditions: (1) melt index (MI2.16, 190° C., under a load of 2.16 kg) is 0.1 to 1.5 g/10 min; (2) density is 0.91 to 0.93 g/cc; (3) polydispersity Index (Mw (weight-average molecular weight)/Mn (number-average molecular weight)) is 3 to 7; (4) Mz (Z-average molecular weight)/Mw (weight-average molecular weight) is 2.3 to 4.5; and (5) COI(Comonomer Orthogonal Index) value calculated by Equation 1 in the specification is 5 to 12. In Equation 1, “SCB number at Mz” represents average number of branches derived from comonomers per 1000 carbon atoms at Z-average molecular weight (Mz), and “SCB number at Mn” represents average number of branches derived from comonomers per 1000 carbon atoms at number-average molecular weight (Mn) based on a molecular weight-comonomer distribution graph.

Disclosed are a polyolefin resin composition and a production method using same. The polyolefin resin satisfies the following conditions: (1) melt index (MI2.16, 190° C., under a load of 2.16 kg) is 0.1 to 1.5 g/10 min; (2) density is 0.91 to 0.93 g/cc; (3) polydispersity Index (Mw (weight-average molecular weight)/Mn (number-average molecular weight)) is 3 to 7; (4) Mz (Z-average molecular weight)/Mw (weight-average molecular weight) is 2.3 to 4.5; and (5) COI(Comonomer Orthogonal Index) value calculated by Equation 1 in the specification is 5 to 12. In Equation 1, “SCB number at Mz” represents average number of branches derived from comonomers per 1000 carbon atoms at Z-average molecular weight (Mz), and “SCB number at Mn” represents average number of branches derived from comonomers per 1000 carbon atoms at number-average molecular weight (Mn) based on a molecular weight-comonomer distribution graph.

The invention is directed to a polyethylene composition comprising 20-90 wt % of a LLDPE A and 80-10 wt % of a LLDPE B, wherein i) LLDPE A is obtainable by a process for producing a copolymer of ethylene and another α-olefin in the presence of an Advanced Ziegler-Natta catalyst, ii) LLDPE B is obtainable by a process for producing a copolymer of ethylene and another α-olefin in the presence of a metallocene catalyst.

The invention is directed to a polyethylene composition comprising 20-90 wt % of a LLDPE A and 80-10 wt % of a LLDPE B, wherein i) LLDPE A is obtainable by a process for producing a copolymer of ethylene and another α-olefin in the presence of an Advanced Ziegler-Natta catalyst, ii) LLDPE B is obtainable by a process for producing a copolymer of ethylene and another α-olefin in the presence of a metallocene catalyst.

Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm.sup.3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft.sup.2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.