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.

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 provides a hybrid supported metallocene catalyst useful for preparing a polyethylene copolymer capable of producing an mLLDPE shrink film having excellent shrinkage and processability with excellent mechanical properties, and a process for preparing a polyethylene copolymer using the same. The hybrid supported metallocene catalyst comprises at least one first metallocene compound selected from compounds represented by the following Chemical Formula 1 and at least one second metallocene compound selected from compounds represented by the following Chemical Formula 2:

##STR00001## wherein the variables are described herein.

The present disclosure provides a hybrid supported metallocene catalyst useful for preparing a polyethylene copolymer capable of producing an mLLDPE shrink film having excellent shrinkage and processability with excellent mechanical properties, and a process for preparing a polyethylene copolymer using the same. The hybrid supported metallocene catalyst comprises at least one first metallocene compound selected from compounds represented by the following Chemical Formula 1 and at least one second metallocene compound selected from compounds represented by the following Chemical Formula 2:

##STR00001## wherein the variables are described herein.

A polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M.sub.w/M.sub.n of <2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000, a molecular weight distribution M.sub.w/M.sub.n of >2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M.sub.w/M.sub.n of >2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 10 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of 200 ≥MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of ≤90° C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of ≥160 Newtons.Math.C° (at a film thickness of about 2 mil) and an oxygen transmission rate (OTR) of ≥600 cm.sup.3 per 100 inch per day (at a film thickness of about 1 mil).

A polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M.sub.w/M.sub.n of <2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000, a molecular weight distribution M.sub.w/M.sub.n of >2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M.sub.w/M.sub.n of >2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 10 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of 200 ≥MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of ≤90° C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of ≥160 Newtons.Math.C° (at a film thickness of about 2 mil) and an oxygen transmission rate (OTR) of ≥600 cm.sup.3 per 100 inch per day (at a film thickness of about 1 mil).

A Ziegler-Natta catalyzed ethylene/alpha-olefins copolymer is provided having sporadic long chain branches and reversed comonomer composition distribution or short chain branching distribution (SCBD) in the high molecular weight fractions. According to the invention, polyethylene film made with the inventive copolymer has a balance of improved physical, optical, mechanical properties as well as processability. In one aspect, the film includes a 1% secant modulus of greater than 25,000 psi, a film haze of less than 10, a film clarity of greater than 90, a dart impart resistance of greater than 500 g/mil, and a MD tear strength of greater than 500 g/mil.

A Ziegler-Natta catalyzed ethylene/alpha-olefins copolymer is provided having sporadic long chain branches and reversed comonomer composition distribution or short chain branching distribution (SCBD) in the high molecular weight fractions. According to the invention, polyethylene film made with the inventive copolymer has a balance of improved physical, optical, mechanical properties as well as processability. In one aspect, the film includes a 1% secant modulus of greater than 25,000 psi, a film haze of less than 10, a film clarity of greater than 90, a dart impart resistance of greater than 500 g/mil, and a MD tear strength of greater than 500 g/mil.

A catalyst composition for polymerizing a polyolefin having excellent processability and impact strength, a process for producing a polyolefin and a polyolefin resin thereof are disclosed. The catalyst composition comprises at least one first organometallic compound of following formula 1; at least one second organometallic compound of following formula 2; and aluminoxane. The polyolefin resin satisfies following properties (i) to (iv) and (vi), (i) melt flow index (ASTM D1238), measured at 190° C., under a load of 2.16 kg: 0.1 to 1.5 g/10 min, (ii) density: 910 to 930 kg/m.sup.3, (iii) the ratio (Mw/Mn), as measured by gel permeation chromatography (GPC): 3.0 to 7.0, (iv) the ratio (Mz/Mw), as measured by GPC: 2.2 to 4.5, and (vi) when the TREF curve of multimodal distribution is deconvoluted, the area of TREF curve having a peak at 50 to 74° C. is 40 to 75% of the total area of the TREF curve.

A catalyst composition for polymerizing a polyolefin having excellent processability and impact strength, a process for producing a polyolefin and a polyolefin resin thereof are disclosed. The catalyst composition comprises at least one first organometallic compound of following formula 1; at least one second organometallic compound of following formula 2; and aluminoxane. The polyolefin resin satisfies following properties (i) to (iv) and (vi), (i) melt flow index (ASTM D1238), measured at 190° C., under a load of 2.16 kg: 0.1 to 1.5 g/10 min, (ii) density: 910 to 930 kg/m.sup.3, (iii) the ratio (Mw/Mn), as measured by gel permeation chromatography (GPC): 3.0 to 7.0, (iv) the ratio (Mz/Mw), as measured by GPC: 2.2 to 4.5, and (vi) when the TREF curve of multimodal distribution is deconvoluted, the area of TREF curve having a peak at 50 to 74° C. is 40 to 75% of the total area of the TREF curve.