This invention relates bisindenyl metallocene catalyst compounds having long (at least 4 carbon atoms) linear alkyl groups substituted at the two position and substituted or unsubstituted aryl groups at the four position and process using such catalyst compounds, particularly in the solution process at higher temperatures.

A method for producing gradient copolymers can include polymerizing a reaction mixture comprising a monomer and a comonomer in the presence of a metallocene catalyst in a loop reactor, wherein in the loop reactor a gradient monomer weight percent in the reaction mixture is about 3 wt % to about 50 wt %, thereby forming a gradient copolymer.

A method for producing gradient copolymers can include polymerizing a reaction mixture comprising a monomer and a comonomer in the presence of a metallocene catalyst in a loop reactor, wherein in the loop reactor a gradient monomer weight percent in the reaction mixture is about 3 wt % to about 50 wt %, thereby forming a gradient copolymer.

The present invention relates to a novel ligand compound, a transition metal compound and a catalyst composition comprising the same. The novel ligand compound and the transition metal compound of the present invention may be useful as a catalyst of polymerization reaction for preparing an olefin-based polymer having a low density.

The present invention relates to a novel ligand compound, a transition metal compound and a catalyst composition comprising the same. The novel ligand compound and the transition metal compound of the present invention may be useful as a catalyst of polymerization reaction for preparing an olefin-based polymer having a low density.

The present invention relates to a novel ligand compound, a transition metal compound and a catalyst composition comprising the same. The novel ligand compound and the transition metal compound of the present invention may be useful as a catalyst of polymerization reaction for preparing an olefin-based polymer having a low density.

The purpose of the present invention is to obtain an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that has a low permanent compression set at low temperatures, is flexible, and has an excellent balance of rubber elasticity at low temperatures and tensile strength at normal temperatures. This ethylene-based polymer is an ethylene⋅α-olefin⋅non-conjugated polyene copolymer that includes units derived from ethylene (A), units derived from an α-olefin (B) containing 4-20 carbon atoms, and units derived from a non-conjugated polyene (C) and satisfies (1)-(4). (1) The molar ratio of (A) to (B) is 40/60-90/10, (2) the contained amount of the units derived from (C) is 0.1-6.0 mol %, (3) ML.sub.(1+4)125° C. is 5-100, and (4) the B value is 1.20 or more.

A process for preliminary polymerization may include washing a catalyst mud comprising a supported metallocene catalyst with at least one saturated hydrocarbon at a temperature from 0° C. to 40° C., a pressure from 20 to 40 kgf/cm.sup.2, and a residence time of at least 30 minutes; continuously feeding the washed catalytic mud to a continuous pre-polymerization reactor; and pre-polymerizing, in the continuous pre-polymerization reactor, ethylene and at least one C.sub.4 to C.sub.10 α-olefin as comonomer, with the washed catalytic mud, to produce a pre-polymer; wherein an average residence time in the continuous pre-polymerization reactor is more than 90 minutes and less than 240 minutes, a reactor temperature is from 10° C. to 50° C., and a reactor pressure from 20 to 40 kgf/cm.sup.2.

A process for preliminary polymerization may include washing a catalyst mud comprising a supported metallocene catalyst with at least one saturated hydrocarbon at a temperature from 0° C. to 40° C., a pressure from 20 to 40 kgf/cm.sup.2, and a residence time of at least 30 minutes; continuously feeding the washed catalytic mud to a continuous pre-polymerization reactor; and pre-polymerizing, in the continuous pre-polymerization reactor, ethylene and at least one C.sub.4 to C.sub.10 α-olefin as comonomer, with the washed catalytic mud, to produce a pre-polymer; wherein an average residence time in the continuous pre-polymerization reactor is more than 90 minutes and less than 240 minutes, a reactor temperature is from 10° C. to 50° C., and a reactor pressure from 20 to 40 kgf/cm.sup.2.

The metallocene compound represented by the following general formula (1): ##STR00001##
(the numerals and signs in the general formula (1) are as described in the description).