Patent ID: 8742043

Claim:
A method of producing an ethylene homopolymer at a polymerization temperature of 60˜250° C. using the transition metal system comprising; (a) a transition metal catalyst system; represented by Formula 1 below, which includes a cyclopentadiene derivative and one or more anionic ligands having an aryl group substituted with an aryl derivative at an ortho-position thereof around a transition metal, the ligands not being crosslinked to each other: wherein M is titanium; Cp is cyclopentadienyl or pentamethylcyclopentadienyl group which forms a η5-bond with the central metal M; D is N—R 1 , in which R 1 is a hydrogen atom or an aryl group of 6 to 30 carbon atoms; R 2 , R 3 , and R 4 are a hydrogen atom; R 5 , R 6 , R 7 , R 8 and R 9 are each independently a hydrogen atom, a linear or nonlinear alkyl group of 1 to 20 carbon atoms, an aryl group of 6 to 30 carbon atoms, or an alkoxy group selected from a methoxy group, ethoxy group, isopropoxy group, and tert-butoxy group, and R 5 , R 6 , R 7 , R 8 and R 9 may be arbitrarily bonded with each other to form rings; E is C—R 10 , in which R 10 is a hydrogen atom; n is an integer of 1 or 2; and X is a halogen atom or an alkyl group of 1 to 20 carbon atoms (b) an aluminoxane and/or a boron compound as a cocatalyst, when the cocatalyst is aluminoxane, the molar ratio of the central metal M to aluminum atom of aluminoxane is 1:50˜1:5,000; when the cocatalyst is boron compound, the molar ratio of the central metal M to boron atom of the boron compound is 1:0.01˜1:100; and when the cocatalyst is a mixture of aluminoxane and boron compound, the molar ratio of the central metal M: boron atom of the boron compound: aluminum atom of the aluminoxane is 1:0.5˜5:5˜500.