Patent ID: 6838522

Claim:
A propylene polymer composition which is the product obtained by the steps comprising: polymerizing propylene in the presence of an olefin polymerization catalyst comprising (i)(a) a zirconocene compound represented by the following formula R 1 R 2 R 3 R 4 Zr wherein two of R 1 , R 2 , R 3 and R 4 are each a substituted indenyl group substituted with aryl group, and linked together through a dimethylsilylene; and remaining two of R 1 , R 2 , R 3 and R 4 are each a halogen atom, and (ii) at least one organoaluminum oxy-compound, to prepare a propylene polymer (A1) having a melt flow rate (MFR), as measured according to ASTM D-1238, at 230° C. under a load of 2.16 kg, of 0.01 to 30 g/10 min.; and a molecular weight distribution (Mw/Mn), as measured by gel permeation chromatography (GPC), of 2 to 3; polymerizing propylene in the presence of an olefin polymerization catalyst comprising (i) (a) a zirconocene compound represented by the following formula R 1 R 2 R 3 R 4 Zr wherein two of R 1 , R 2 , R 3 and R 4 are each a substituted indenyl group substituted with aryl group, and linked together through a dimethylsilylene; and the remaining two of R 1 , R 2 , R 3 and R 4 are each a halogen atom, and (ii) at least one organoaluminum oxy-compound, to prepare a propylene polymer (A2) having a melt flow rate (MFR), as measured according to ASTM D-1238, at 230° C. under a load of 2.16 kg, of 30 to 1000 g/10 min.; and a molecular weight distribution (Mw/Mn), as measured by gel permeation chromatography (GPC), of 2 to 4; wherein the ratio ((A2)/(A1)) of the MFR of said propylene polymer (A2) to the MFR of said propylene polymer (A1) is not less than 30; and mixing 10 to 90% by weight of the propylene polymer (A1) and 10 to 90% by weight of the propylene polymer (A2).