Patent ID: 7915360

Claim:
A method for preparing a polyolefin, comprising the step of polymerizing olefinic monomers in the presence of a supported catalyst for olefin polymerization, the polyolefin having a weight-average molecular weight (Mw) of 150,000 to 250,000 and a density of 0.900 to 0.970 g/cc, and the support catalyst comprising a) a support containing a hydroxyl group on a surface thereof at an amount of 0.1 to 10 mmol/g; b) a cocatalyst, which is a compound represented by Formula 4; and c) a transition metal catalyst compound represented by Formula 1: [Al( R 8)-O] [Formula 4] wherein R8s may be the same or different from each other, and each independently a halogen radical; a hydrocarbyl radical having 1 to 20 carbon atoms; or a hydrocarbyl radical having 1 to 20 carbon atoms that is substituted with halogen; and a is an integer of 2 or more; and wherein R1 and R2 may be the same or different from each other, and each independently hydrogen; an alkyl radical having 1 to 20 carbon atoms; an alkenyl radical having 2 to 20 carbon atoms; an aryl radical having 6 to 20 carbon atoms; a silyl radical; an alkylaryl radical having 7 to 20 carbon atoms; an arylalkyl radical having 7 to 20 carbon atoms; or a metalloid radical of Group 4 metal substituted with hydrocarbyl; wherein R1 and R2, or two R2s may be connected by an alkylidine radical that contains an alkyl radical having 1 to 20 carbon atoms or aryl radical having 6 to 20 carbon atoms to form a ring; R3s may be the same or different from each other, and each independently hydrogen; a halogen radical; an alkyl radical having 1 to 20 carbon atoms; an aryl radical having 6 to 20 carbon atoms; an alkoxy radical having 1 to 20 carbon atoms; an aryloxy radical having 6 to 20 carbon atoms; or an amido radical; wherein two or more of R3s may be connected to each other to form an aliphatic or aromatic ring; CY1 is a substituted or unsubstituted, aliphatic or aromatic ring, and CY1 may be substituted with halogen radical; an alkyl radical having 1 to 20 carbon atoms; an alkenyl radical having 2 to 20 carbon atoms; an aryl radical having 6 to 20 carbon atoms; an alkylaryl radical having 7 to 20 carbon atoms; an arylalkyl radical having 7 to 20 carbon atoms; an alkoxy radical having 1 to 20 carbon atoms; an aryloxy radical having 6 to 20 carbon atoms; or an amido radical, in the case where CY1 is substituted with plural substituents, two or more of the substituents may be connected to each other to form an aliphatic or aromatic ring; M is a transition metal of Group 4; and Q1 and Q2 may be the same or different from each other, and each independently a halogen radical; an alkyl radical having 1 to 20 carbon atoms; an alkenyl radical having 2 to 20 carbon atoms; an aryl radical having 6 to 20 carbon atoms; an alkylaryl radical having 7 to 20 carbon atoms; an arylalkyl radical having 7 to 20 carbon atoms; an alkyl amido radical having 1 to 20 carbon atoms; an aryl amido radical having 6 to 20 carbon atoms; or an alkylidene radical having 1 to 20 carbon atoms.