Abstract: Provided is a polypropylene resin composition having excellent impact resistance, impact strength at low temperature and transparence comprising ethylene-alpha olefin copolymer (c) to a polypropylene resin composition in which the ratio of viscosity is regulated by adjusting molecular weight of propylene-alpha olefin random copolymer (a) and propylene-alpha olefin elastic copolymer (b), thereby regulating impact resistance and flexural modulus of the polypropylene resin composition and improving transparence; therefore, applying as various products including cold-storage containers for freezer and refrigerator, food packaging container, extrusion blow molding material, film, sheet and bottle cap, etc.

Abstract: Disclosed is a method of preparing a highly transparent polypropylene comprising a step of prepolymerizing an ?-olefin and a vinyl cyclic saturated hydrocarbon in the presence of a Zegler-Natta catalyst and an external electron donor, wherein a step of adding and prepolymerizing the ?-olefin is followed by a step of adding and prepolymerizing the vinyl cyclic saturated hydrocarbon. The method provides polypropylene having superior tacticity and transparency with not decreasing the activity of the polymerization catalyst at the polymerization of propylene.

Abstract: Provided is a polypropylene resin composition having excellent impact resistance, impact strength at low temperature and transparence comprising ethylene-alpha olefin copolymer (c) to a polypropylene resin composition in which the ratio of viscosity is regulated by adjusting molecular weight of propylene-alpha olefin random copolymer (a) and propylene-alpha olefin elastic copolymer (b), thereby regulating impact resistance and flexural modulus of the polypropylene resin composition and improving transparence; therefore, applying as various products including cold-storage containers for freezer and refrigerator, food packaging container, extrusion blow molding material, film, sheet and bottle cap, etc.