ADVANCED TRANSITION METAL CATALYTIC SYSTEMS IN TERMS OF COMONOMER INCORPORATIONS AND METHODS FOR PREPARING ETHYLENE HOMOPOLYMERS OR COPOLYMERS OF ETHYLENE AND .ALPHA.-OLEFINS USING THE SAME

Provided is a homogeneous catalytic system for use in preparing an ethylene homopolymer or a copolymer of ethylene and a-olefin, and more particularly a Group 4 transition metal compound in which a cyclopentadienyl derivative 3,4-positions of which are substituted with alkyls and an electron-donating substituent are crosslinked around a Group 4 transition metal. Also provided is a method of preparing an ethylene homopolymer or a copolymer of ethylene and a-olefin, having high molecular weight, under high-temperature solution polymerization conditions using the catalytic system including such a transition metal compound and a co-catalyst composed of an aluminum compound, a boron compound or a mixture thereof. The catalyst according to present invention has high thermal stability and enables the incorporation of a-olefin, and is thus effective in preparing an ethylene homopolymer or a copolymer of ethylene and a-olefin, having various properties, in industrial polymerization processes.