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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):

The present invention relates to filtration media made from melt-blown fibers having improved barrier properties. The melt-blown fibers in the filtration media of the invention are made of a visbroken metallocene-catalyzed propylene homopolymer composition with specified melting temperature Tm and molecular weight distribution (MWD).

A heterophasic polypropylene copolymer having an MFR2 of 0.05 to 20 g/10 min (ISO 1133 at 230° C. with a loading of 2.16 kg) and a melting point (Tm) of 156 to 164° C. (measured by DSC according to ISO 11357) wherein the heterophasic polypropylene copolymer comprises at least the following components: (A) 55.0 to 95.0 wt % of a crystalline fraction (CF) having a comonomer content of 0 to 3.0 wt %; and (B) 5.0 to 45.0 wt % of a soluble fraction (SF) having a comonomer content of 12 to 45 wt %; wherein the intrinsic viscosity (IV) (in decalin at 135° C.) of the soluble fraction (SF) is 2.5 to 11 dl/g, and wherein the amount of crystalline fraction (CF) and the amount of soluble fraction (SF) are determined in 1,2,4-trichlorobenzene at 40° C.

Processes of polymerizing olefin monomers using catalyst systems and catalysts systems that include a procatalyst having a structure according to formula (I):

The present invention relates to a polyolefin film and to a process for preparing the same. The polyolefin film, specifically, the linear low-density polyethylene film according to an embodiment of the present invention is readily formed and has excellent mechanical strength and excellent heat seal characteristics.

The present invention relates to an anionic polymerization initiator represented by Formula 1 below for producing a polyolefin-polystyrene block copolymer, an anionic polymerization initiator composition, and a production method therefor,

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wherein R.sub.1, and A are described herein.

A catalyst system including the product of the combination of an unbridged Group 4 metallocene compound and a 2,6-bis(imino)pyridyl iron complex is provided. A process for the polymerization of monomers (such as olefin monomers) and a polymer produced therefrom are also provided.

The present invention relates to melt-blown webs having no shots and improved barrier properties, whereby the melt-blown webs are made of a visbroken metallocene-catalyzed propylene homopolymer composition with specified melting temperature T.sub.m, content of 2,1 erythro regiodefects and molecular weight distribution (MWD).

A polyethylene suitable for use in blown film can comprise ethylene derived units and C.sub.3 to C.sub.12 α-olefin derived units at 0.5 wt % to 10 wt % of the polyethylene and have a reversed-co-monomer index (RCI,m) of 35 to 100, a comonomer distribution ratio (CDR-2,m) of 1.20 to 1.80, and a weight average molecular weight (Mw) to number average molecular weight (Mn) of 5 to 7.

A polyethylene comprising of ethylene derived units and 0.5 wt % to 10 wt % C.sub.3 to C.sub.12 α-olefin derived units may be synthesized using a mixed catalyst that comprises rac-dimethylsilylbis(tetrahydroindenyl)zirconium dichloride and a zirconium co-catalyst in a mole ratio of 50:50 to 90:10, and wherein the zirconium co-catalyst is a poor comonomer incorporator as compared to the rac-dimethylsilylbis(tetrahydroindenyl)zirconium dichloride catalyst. Such a polyethylene may have a density of 0.91 g/cm.sup.3 to 0.93 g/cm.sup.3, an I.sub.2 value of 0.5 g/10 min to 2 g/10 min, an I.sub.21 value of 25 g/10 min to 75 g/10 min, an I.sub.21/I.sub.2 ratio of 25 to 75, a molar reversed-co-monomer index (RCI,m) of 30 to 180, a phase angle equal or lower than 70° at complex modulus G* of 10,000 Pa, a Θ.sub.2 of 1.5 radians to −1.5 radians, and a low density population of 50% and 70% by weight of the polyethylene.