| abstract |
A process for producing a polyolefin resin composition which comprises a first polymerization step in which a C4-20 α-olefin, a styrene compound, and a cycloolefin compound are polymerized in the presence of a specific catalyst and a second polymerization step in which the polymer obtained in the first polymerization step is subjected to copolymerization of a C2-20 α-olefin, a styrene compound, and a cycloolefin compound in the presence of a polyene; and a polypropylene composition which has a branching parameter (a) and branching index (g) in respective specific ranges and has been regulated with respect to an elongational viscosity/time curve, deterioration parameter (D), or the content of high-molecular components. By the process, a highly homogeneous polyolefin resin composition is obtained which has improved melt tension and improved melt processability. The polypropylene composition is excellent in melt elasticity and formability and can give a foamed molding, sheet, blow molding, etc. |