| abstract |
In a process for polymerizing an olefin in the presence of a catalyst system combining an organoaluminum compound with a hydrocarbon insoluble solid catalytic component prepared by treating a hydrocarbon solution containing a magnesium compound, and a titanium compound with an aluminum halide having the formula AlRl1X3-l1 (R1 represents an alkyl, aryl or cycloalkyl group and X1 represents a halogen atom, and l is 1</=l</=2), an improvement characterized in that the magnesium compound is a compound having the formula Mg(OR2)mX2-m2 (R2 represents an alkyl, aryl or cycloalkyl group; X2 represents a halogen atom; and m is 1 or 2) and the titanium compound is a compound having the formula Ti(OR3)nX4-n3 (R3 represents an alkyl, aryl or cycloalkyl group; X3 represents a halogen atom; n is 1, 2 or 3). |