OLEFIN (CO)POLYMER COMPOSITION AND PRODUCTION THEREOF

PROBLEM TO BE SOLVED: To provide an olefin (co)polymer compsn. which has high melt tension, crystallization temp., and rigidity by producing a small amt. of a high-mol.-wt. polyolefin in advance to give a preactivated catalyst, adding a specific catalyst thereto, and conducting polymn., and to provide a process for producing the same. SOLUTION: An olefin is (co)polymerized by using a polymn. catalyst which contains 0.01-5 pts.wt. olefin (co)polymer having an intrinsic viscosity [ηa ] (at 135 deg.C in tetralin) of 15-100 dl/g and catalyst components (A), (B), and (C), thus giving an olefin (co)polymer compsn. mainly comprising 100 pts.wt. olefin (co)polymer having an intrinsic viscosity [ηb ] (at 135 deg.C in tetralin) of 0.2-10 dl/g. Catalyst component A is a titanium trichloride compsn.; catalyst component B, an organoaluminum compd.; and catalyst component C, at least one compd. selected from among arom. carboxylic esters and organosilicon compds. each having at least either an SiOC or mercapto group.