Provided are a novel metallocene-supported catalyst and a method of preparing a polyolefin using the same. The metallocene-supported catalyst according to the present disclosure may be used in the preparation of polyolefins, it may have excellent activity and excellent reactivity with comonomers, and it may prepare olefinic polymers having a high molecular weight and a low molecular weight.

This invention relates to metallocene compounds represented by the formula: ##STR00001##
catalyst systems comprising said metallocene compound and an activator or a reaction product of the metallocene compound with the at least one activator, and polymerization processes using such metallocene compounds and activators, where Cp.sub.a and Cp.sub.b are optionally-substituted cyclopentadienyl rings; A is bridging group; q is zero or 1; Q is O, O(CR.sup.3R.sup.4).sub.m, (CR.sup.3R.sup.4).sub.mO, or (CR.sup.3R.sup.4).sub.m; m is 0 to 18; Z is (CR.sup.3R.sup.4).sub.2; LA is a Lewis acid; M is a transition metal; X.sup.1 and X.sup.2 are independently R.sup.5 or OR.sup.5; R.sup.1 and R.sup.2 are independently selected from optionally-substituted hydrocarbyl groups; R.sup.3 and R.sup.4 are independently selected from the group consisting of H, halogen, and an optionally-substituted hydrocarbyl group; and R.sup.5 is alkyl, aryl, perfluoroalkyl, or perfluoroaryl.

Disclosed are metallocene compounds, catalyst compositions comprising at least one metallocene compound, processes for polymerizing olefins, methods for making catalyst compositions, olefin polymers and articles made from olefin polymers. In an aspect, a metallocene compound and catalyst composition are disclosed in which the metallocene contains at least one indenyl ligand, the indenyl ligand containing at least one halogenated substituent, such as a fluorinated substituent. These metallocene compounds and catalyst compositions can produce polyethylene having unexpectedly low levels of short chain branching.

Provided is an ethylene/1-hexene copolymer which has excellent long-term physical properties and processability, and thus may be usefully applied to manufacturing high-pressure resistant heating pipes, PE-RT pipes, large-diameter pipes, or the like.

In the present disclosure, there are provided a polyethylene having improved low-temperature sealing properties with an increase in the content and molecular weight of a low crystalline polymer, and a method for preparing the same.

There are provided a polyethylene capable of improving tensile strength while maintaining excellent processability and Mooney viscosity characteristics when preparing a chlorinated polyethylene compound by implementing a molecular structure having a low content of low molecular weight and a high content of high molecular weight, and a chlorinated polyethylene prepared using the same.

The present invention relates to a polyethylene copolymer which has excellent processability and long-term durability, and thus is useful for hollow molding of a pipe or the like.

The present invention is directed to a polyolefin composition comprising a blend of a heterophasic polypropylene composition and 5.0 to 30.0 wt % of an ethylene homo- or copolymer, the ethylene homo- or copolymer having a density of at least 941 kg/m.sup.3 and a melt flow rate MFR.sub.21 of 1 to 10 g/10 min. The heterophasic polypropylene composition comprises a propylene homopolymer or a propylene ethylene random copolymer and an elastomeric ethylene propylene rubber, and is characterized by 75.0 to 95.0 wt % of a crystalline fraction having an ethylene content of up to 4.0 wt % and an MFR.sub.2 of 0.1 to 100 g/10 min, and 5.0 to 25.0 wt % of a soluble fraction having an ethylene content of 10.0 to 70.0 wt % and an intrinsic viscosity of 1.0 to 4.0 dl/kg, wherein the crystalline fraction and the soluble fraction are determined in 1,2,4-trichlorobenzene at 40° C.

The present invention relates to a transition metal compound for a catalyst for olefin polymerization and to a catalyst for olefin polymerization comprising the same. Specifically, the present invention relates to a transition metal compound for an olefin polymerization catalyst in which an allyltrimethylsilane substituent is introduced into the cyclopentadienyl group and to a catalyst for olefin polymerization comprising the same.

The present disclosure relates to a polyethylene having high degree of crosslinking and a crosslinked polyethylene pipe including the same. The polyethylene according to the present disclosure has a high content of ultra-high molecular weight, and thus a crosslinking rate is improved, and thus a sufficient degree of crosslinking is exhibited even when the crosslinking time is shortened, thereby exhibiting excellent strength and pressure resistance characteristics.