Patent ID: 7259215

Claim:
A process for producing a propylene-ethylene block copolymer in which propylene is copolymerized with ethylene in the presence of a catalyst system comprising a metallocene catalyst (1), a metallocene catalyst (2), a porous carrier (3), at least one aluminoxane (4) and/or compound (4) which can form an ionic complex by reacting with the metallocene catalysts described above and, optionally, an organic aluminum compound (5), wherein the metallocene catalyst (1) is a monocross-linked metallocene catalyst, and the metallocene catalyst (2) is a dicross-linked metallocene catalyst, and wherein the monocross-linked metallocene catalyst is a transition metal compound represented by general formula (I): wherein E1 represents a bonding group which cross-links two conjugate five-membered ring ligands; R1 and R2 each represent a hydrocarbon group, a halogen atom, an alkoxy group, a silicon-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group; R3 to R6 each represent hydrogen, a hydrocarbon group, a halogen atom, an alkoxy group, a silicon-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group; M1 represents a transition metal of the IV to VI group in the periodic table; X1 and Y1 each represent a covalent bonding ligand; and X1 and Y1 may be combined with each other to form a ring structure; and the dicross-linked metallocene catalyst is a transition metal compound represented by general formula (II) or general formula (III): wherein E2 and E3 independently represent a silylene group, an oligosilylene group, or a side chain lower alkyl or phenyl-substituted group thereof; R9 to R18 each represent hydrogen, a hydrocarbon group, a halogen atom, an alkoxy group, a silicon-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group; R7, R8, R19 and R20 each represent a hydrocarbon group, a halogen atom, an alkoxy group, a silicon-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, a nitrogen-containing hydrocarbon group or a boron-containing hydrocarbon group; M2 represents a transition metal of the IV to VI group in the periodic table; X2 and Y2 each represent a covalent bonding ligand; and X1 and Y1 may be combined with each other to form a ring structure.