Ethylene-based polymers are characterized by a density from 0.92 to 0.955 g/cm.sup.3, a HLMI of less than 35 g/10 min, and a ratio of a number of short chain branches (SCBs) per 1000 total carbon atoms at Mz to a number of SCBs per 1000 total carbon atoms at Mn in a range from 11.5 to 22. These polymers can have a higher molecular weight (HMW) component and a lower molecular weight (LMW) component, in which a ratio of a number of SCBs per 1000 total carbon atoms at Mn of the HMW component to a number of SCBs per 1000 total carbon atoms at Mn of the LMW component is in a range from 10.5 to 22. These ethylene polymers can be produced using a dual catalyst system containing an unbridged metallocene compound with an indenyl group having at least one halogen-substituted hydrocarbyl substituent with at least two halogen atoms, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

The present disclosure generally relates to catalyst systems, polyethylene compositions, and uses of such compositions in, e.g., films. In an embodiment is provided a film that includes a polyethylene composition, comprising: ethylene and a C.sub.3-C.sub.40 olefin comonomer, the polyethylene composition having at least 65 wt % ethylene content and from 0 wt % to 35 wt % of a C.sub.3-C.sub.40 olefin comonomer content based upon the total weight of the composition, the film having: an average of MD and TD 1% secant modulus of 43,000 psi or greater, and a Dart Drop Impact Strength of greater than 500 g/mil. In another embodiment is provided a process for producing a polyethylene composition that includes introducing ethylene and a C.sub.3-C.sub.40 alpha-olefin to a catalyst system, the catalyst system comprising a first catalyst compound, a second catalyst compound, and an activator; and forming a polyethylene composition.

The present disclosure generally relates to catalyst systems, polyethylene compositions, and uses of such compositions in, e.g., films. In an embodiment is provided a film that includes a polyethylene composition, comprising: ethylene and a C.sub.3-C.sub.40 olefin comonomer, the polyethylene composition having at least 65 wt % ethylene content and from 0 wt % to 35 wt % of a C.sub.3-C.sub.40 olefin comonomer content based upon the total weight of the composition, the film having: an average of MD and TD 1% secant modulus of 43,000 psi or greater, and a Dart Drop Impact Strength of greater than 500 g/mil. In another embodiment is provided a process for producing a polyethylene composition that includes introducing ethylene and a C.sub.3-C.sub.40 alpha-olefin to a catalyst system, the catalyst system comprising a first catalyst compound, a second catalyst compound, and an activator; and forming a polyethylene composition.

Provided is a particle drying method capable of sufficiently removing the volatile component and down-regulating the increase of the viscosity of the particles after the removal of the volatile component. There is provided a method for producing heterophasic propylene polymerization material particles, the method including: (1) performing monomer polymerization in the presence of a catalyst including a solid catalyst component so as to obtain a component I; (2) performing monomer polymerization in the presence of the component I so as to obtain the component II, so that particles including a volatile component are produced; and (3) causing the particles to contact with an inert gas-containing stream so as to remove the volatile component from the particles.

Provided is a particle drying method capable of sufficiently removing the volatile component and down-regulating the increase of the viscosity of the particles after the removal of the volatile component. There is provided a method for producing heterophasic propylene polymerization material particles, the method including: (1) performing monomer polymerization in the presence of a catalyst including a solid catalyst component so as to obtain a component I; (2) performing monomer polymerization in the presence of the component I so as to obtain the component II, so that particles including a volatile component are produced; and (3) causing the particles to contact with an inert gas-containing stream so as to remove the volatile component from the particles.

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.

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.

This invention relates to high porosity (≧15%) and/or low pore diameter (PD<165 μm) propylene polymers and propylene polymerization processes using single site catalyst systems with supports having high surface area (SA≧400 m.sup.2/g), low pore volume (PV≦2 mL/g), a specific mean pore diameter range (PD=1-20 nm), and high average particle size (PS≧30 μm).

This invention relates to high porosity (≧15%) and/or low pore diameter (PD<165 μm) propylene polymers and propylene polymerization processes using single site catalyst systems with supports having high surface area (SA≧400 m.sup.2/g), low pore volume (PV≦2 mL/g), a specific mean pore diameter range (PD=1-20 nm), and high average particle size (PS≧30 μm).

The present invention relates to a rotomolded article, comprising at least one layer, wherein said at least one layer comprising comprises at least one metallocene-catalyzed polyethylene resin comprising at least two metallocene-catalyzed polyethylene fractions A and B; and at least one ionomer;

wherein the polyethylene resin comprises: at least 25% to at most 55% by weight of polyethylene fraction A based on the total weight of the polyethylene resin, wherein fraction A has a density at least 0.005 g/cm.sup.3 higher than the density of the polyethylene resin; and wherein the polyethylene resin has a density of at least 0.930 g/cm.sup.3 to at most 0.954 g/cm.sup.3 as measured according to ASTM D-1505 at 23° C.; a melt index MI2 of at least 1.0 g/10 min to at most 25.0 g/10 min as determined according to ISO 1133, condition D, at 190° C. and under a load of 2.16 kg.

The present invention also relates to a process for preparing said rotomolded article.