A metallocene complex of formula (I): each X is a sigma-ligand; in the group R.sub.2Si— at least one R is methyl or ethyl, and the other R is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl, pentyl, hexyl, cyclohexyl and phenyl; each R.sup.1 independently is the same or can be different and are a CH.sub.2—R.sup.7 group, with R.sup.7 being H or linear or branched C.sub.1-6-alkyl group, C.sub.3-8 cycloalkyl group, or C.sub.6-10 aryl group; each R.sup.2 is independently a —CH═, —CY═, —CH.sub.2—, —CHY— or —CY.sub.2— group, wherein Y is a C.sub.1-6 hydrocarbyl group and where n is 2-6; each R.sup.3 and R.sup.4 are independently the same or can be different and are hydrogen, a linear or branched C.sub.1-6-alkyl group, a C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group, C.sub.6-20 aryl group, or an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group; R.sup.5 is a linear or branched C.sub.1-6-alkyl group, C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group or C.sub.6-20-aryl group; and R.sup.6 is a C(R.sup.8).sub.3 group, with R.sup.8 being a linear or branched C.sub.1-6 alkyl group; (A) wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is not hydrogen, and wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is hydrogen; or (B) wherein one R.sup.3 is an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4 position of each phenyl group and the two other R.sup.3 groups are tert-butyl groups; and/or (C) wherein one R.sup.4 is an —OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4-position of the phenyl ring and the two other R.sup.4 groups are tert-butyl groups.

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Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.

This disclosure provides new methods for the design and development of ethylene polymerization catalysts, including Group 4 metallocene catalysts such as zirconocenes, which are based on an improved ability to adjust co-monomer incorporation into the polymer. Computational analyses with and without dispersion corrections revealed that designing catalyst scaffolds which induce stabilizing non-covalent dispersion type interactions with incoming α-olefin co-monomers can be used to modulate co-monomer selectivity into the polyethylene chain. Demonstrated herein is a lack of correlation of computed ΔΔG.sup.‡ values against experimental ΔΔG.sup.‡ values when the dispersion correction (D3BJ) was disabled, and B3LYP was used in the absence of Grimme's D3 dispersion and Becke-Johnson (BJ) dampening, but a correlation of computed against experimental ΔΔG.sup.‡ with B3LYP+D3BJ, which are used to design new catalyst scaffolds.

There is provided a method for preparing a metallocene-supported catalyst that exhibits catalytic activity, and yet, can decrease fine generation, and thus, can minimize fouling and chunk generation, and can stably prepare polyethylene having excellent properties.

The present disclosure relates to a polyethylene, which is reacted with chlorine to prepare a chlorinated polyethylene having excellent processability and size stability during high-speed extrusion by optimizing a high-crystalline region in a molecular structure, and a CPE compound including the same.

Provided is an ethylene/1-butene copolymer having excellent processability and stress cracking resistance. The ethylene/1-butene copolymer according to the present invention may be applied to a high-pressure resistant heating pipe, a PE-RT pipe, a large diameter pipe, etc.

The present invention relates to a metallocene compound, and preparation and use thereof, and the compound can be used as a catalyst for synthesis of poly-α-olefin as lubricating base oil. The metallocene compound includes a substituted aryl group, a bridged atom, an optionally unsubstituted, 3-mono-substituted or 3,6-disubstituted 5H-indeno [1,2-b] pyridyl group or optionally unsubstituted, 3-mono-substituted or 3,6-disubstituted 5H-indeno [1,2-b] thiopyranyl group, and a metal coordination group. As a catalyst, the metallocene compound is shown to be structurally stable and high in catalytic efficiency, and the preparation of the catalyst is relatively easy in operation, high in yield, low in cost, low in pollution and easy to scale up for industrial production.

Provided is syndiotactic polypropylene-based ethylene-propylene copolymers comprising a) 5 to 15% by weight of ethylene and 85 to 95% by weight of propylene; b) 60 to 90% rr triads; c) Mw (LS) of 10 to 250 kg/mol; and d) no substantial melting peak, wherein the heat of fusion of the peak is 5 J/g or less as determined by differential scanning calorimetry at a scan rate of 10° C./min (ASTM D3418-03).

The present invention relates to a novel ligand compound, a metallocene compound, and a method for preparing an olefin-based polymer using the same. The metallocene compound according to the present invention and a catalyst composition comprising the same have excellent polymerization activity, and yet, have excellent comonomer insertion capability, and thus, can be used to prepare olefin-based polymer having wide molecular weight distribution and the resulting excellent processability.

This invention relates to a novel metallocene compound, a catalyst composition comprising the metallocene compound, and a method for preparing olefin polymer using the catalyst composition.