Abstract: Provided is a novel olefin polymer which is excellent in lightness and moldability, has high rigidity and yields molded products excellent in flexural elasticity. The olefin polymer includes a propylene initial polymerization product formed in the presence of an olefin polymerization catalyst which is a contact reaction product of an olefin polymerization solid catalyst component containing a titanium atom, a magnesium atom, a halogen atom and an internal electron donating compound, at least one organoaluminum compound selected from the compounds of the general formula (I), and a first external electron donating compound; and a polypropylene part formed of a propylene polymerization product formed in the presence of the olefin polymerization catalyst and a second external electron donating compound higher in adsorption to the surface of the olefin polymerization solid catalyst component than the first external electron donating compound.

Abstract: A solid catalyst component for polymerization of an olefin having a polymerization activity equivalent to or higher than a solid catalyst component having a phthalic acid ester compound or diether compound as an internal electron-donating compound, and can produce an olefin polymer having excellent bulk density and low content of olefin oligomers.

Abstract: A solid catalyst component for polymerization of an olefin having a polymerization activity equivalent to or higher than a solid catalyst component having a phthalic acid ester compound or diether compound as an internal electron-donating compound, and can produce an olefin polymer having excellent bulk density and low content of olefin oligomers.

Abstract: A method for manufacturing a solid catalyst component for polymerization of an olefin is disclosed, which includes bringing a magnesium compound and a specific styrene-based compound into contact with each other to obtain a preliminary contact product, and subsequently bringing the preliminary contact product, a titanium halide compound, and an internal electron donor compound into contact with each other to obtain a solid catalyst component for polymerization of an olefin; and a method for manufacturing a catalyst for polymerization of an olefin and a method for manufacturing a polymer of an olefin using the solid catalyst component for polymerization of an olefin obtained by the manufacturing method.

Abstract: Provided is a novel olefin polymer which is excellent in lightness and moldability, has high rigidity and yields molded products excellent in flexural elasticity. The olefin polymer includes a propylene initial polymerization product formed in the presence of an olefin polymerization catalyst which is a contact reaction product of an olefin polymerization solid catalyst component containing a titanium atom, a magnesium atom, a halogen atom and an internal electron donating compound, at least one organoaluminum compound selected from the compounds of the general formula (I), and a first external electron donating compound; and a polypropylene part formed of a propylene polymerization product formed in the presence of the olefin polymerization catalyst and a second external electron donating compound higher in adsorption to the surface of the olefin polymerization solid catalyst component than the first external electron donating compound.