Patent ID: 7884164

Claim:
A catalyst system for olefin polymerization, comprising (a) a transition metal compound containing an element of Groups IV, V or VI of the periodic table as a solid main catalyst component; (b) an organic metal compound containing an element of Group XIII of the periodic table as a cocatalyst component; and (c) an organosilane compound represented by the following Formula 1 as an external electron donor: wherein R 1 and R 2 are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a cycloalkyl group having 5 to 30 carbon atoms, and at least one of R 1 and R 2 is a branched alkyl group having 1 to 20 carbon atoms; R 7 , R 8 , R 9 , and R 10 are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a cycloalkyl group having 5 to 30 carbon atoms; and n and m are each independently an integer of 1 to 3.