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.

This invention relates to an oriented polyethylene film comprising polyethylene having: (A) a melt flow index of 1.0 g/10 min or more, (B) a density of 0.90 g/cm.sup.3 to less than 0.940 g/cm.sup.3, (C) a g′.sub.LCB of greater than 0.8, (D) ratio of comonomer content at Mz to comonomer content at Mw is greater than 1.0, (E) ratio of comonomer content at Mn to comonomer content at Mw is greater than 1.0, and (F) a ratio of the g′.sub.LCB to the g′.sub.Zave is greater than 1.0, where the film has a 1% secant in the transverse direction of 70,000 psi or more and Dart Drop of 350 g/mil or more.

A biaxially-oriented film comprising a polyethylene having (A) a melt flow index of 1.0 g/10 min or more, (B) a density of 0.90 g/cm3 to less than 0.940 g/cm.sup.3, (C) a g′.sub.LCB of greater than 0.8, (D) ratio of comonomer content at Mz to comonomer content at Mw is greater than 1.0, (E) ratio of comonomer content at Mn to comonomer content at Mw is greater than 1.0, and (F) a ratio of the g′.sub.LCB to the g′.sub.zave is greater than 1.0, and where the film has a 1% secant in the transverse direction of 70,000 psi or more and Dart Drop of 350 g/mil or more.

This invention relates to a biaxially-oriented polyethylene film comprising polyethylene having: (A) a melt index, I.sub.2, of 1.0 g/10 min or greater; (B) a density of 0.925 g/cm.sup.3 to 0.945 g/cm.sup.3; (C) a g′.sub.vis of less than 0.8; (D) an Mz of 1,000,000 g/mol or more; (E) an Mw/Mn of 5 or more; (F) an Mw of 100,000 g/mol or more; (G) a ratio of the g′.sub.LCB to the g′.sub.Zave is greater than 1.0; and (H) a Strain Hardening Ratio of 4 or more, where the film has a 1% secant in the transverse direction of 60,000 psi or more, a Dart Drop of 250 g/mil or more, and a ratio of 1% secant MD/1% secant TD is 0.65 or more.

The present invention relates to a new multimodal ethylene copolymer (P), to the use of the copolymer in film applications and to a film comprising the copolymer of the invention.

The present disclosure relates to a method for preparing a polyolefin using a supported hybrid metallocene catalyst. According to the present disclosure, a polyolefin having a narrow molecular weight distribution can be prepared very effectively by introducing a cocatalyst in an optimum content in the presence of a supported hybrid metallocene catalyst containing two or more metallocene compounds having a specific chemical structure. The polyolefin prepared according to the present disclosure exhibits excellent uniformity in chlorine distribution in polyolefin during chlorination, thereby significantly improving elongation of the chlorinated polyolefin, compatibility with PVC and impact reinforcing performance. Thus, it exhibits excellent chemical resistance, weather resistance, flame retardancy, processability and impact strength reinforcing effect, and can be suitably applied as an impact reinforcing agent for PVC pipes and window profiles.

The polyethylene according to the present invention has narrow particle size distribution, and can minimize a change in the crystal structure, and thus, it can be reacted with chlorine to prepare chlorinated polyethylene having excellent chlorination productivity and thermal stability.

The present invention relates to polyolefin. More specifically, the present invention relates to polyolefin having excellent dart drop impact strength, and exhibiting improved transparency, and such polyolefin has a density of 0.915 g/cm3 to 0.930 g/cm3 measured according to ASTM D1505; and satisfies the following requirements (provided that S1+S2+S3=1), when measuring the relative content of peak area according to melting temperature (Tm) using SSA (Successive Self-nucleation and Annealing) analysis: the content(S1) of peak area at Tm less than 100° C. is 0.33 to 0.35; the content(S2) of peak area at Tm of 100° C. or more and 120° C. or less is 0.52 to 0.56; and the content(S3) of peak area at Tm greater than 120° C. is 0.10 to 0.14.

Embodiments provide bimodal polymerization catalyst systems comprising metallocene olefin polymerization catalysts and biphenylphenol polymerization catalysts made from biphenylphenol polymerization precatalysts of Formula I.