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.

A solid catalyst component for olefin polymerization exhibits excellent catalytic activity during polymerization, and can produce a polymer that exhibits excellent stereoregularity, bulk density, and the like even when a polymerization catalyst is produced in an inert atmosphere using an electron donor compound other than a phthalic ester and an organosilicon compound. The solid catalyst component for olefin polymerization is produced by bringing a vinylsilane compound (d) into contact with a catalyst component, the catalyst component being a powdery solid component obtained by bringing a magnesium compound (a), a titanium halide compound (b), and an electron donor compound (c) into contact with each other, the electron donor compound (c) being one or more compounds that do not include a phthalic ester structure, and include one or more groups selected from an ester group, a carbonate group, and an ether group, the vinylsilane compound (d) being brought into contact with the catalyst component in a 0.1 to 15-fold molar quantity with respect to the molar quantity (on a titanium atom basis) of the titanium halide compound (b) included in the catalyst component.

A solid catalyst component for olefin polymerization exhibits excellent catalytic activity during polymerization, and can produce a polymer that exhibits excellent stereoregularity, bulk density, and the like even when a polymerization catalyst is produced in an inert atmosphere using an electron donor compound other than a phthalic ester and an organosilicon compound. The solid catalyst component for olefin polymerization is produced by bringing a vinylsilane compound (d) into contact with a catalyst component, the catalyst component being a powdery solid component obtained by bringing a magnesium compound (a), a titanium halide compound (b), and an electron donor compound (c) into contact with each other, the electron donor compound (c) being one or more compounds that do not include a phthalic ester structure, and include one or more groups selected from an ester group, a carbonate group, and an ether group, the vinylsilane compound (d) being brought into contact with the catalyst component in a 0.1 to 15-fold molar quantity with respect to the molar quantity (on a titanium atom basis) of the titanium halide compound (b) included in the catalyst component.

Supported Ziegler-Natta ethylene polymerization procatalyst comprising special bi-(oxygen containing ring) compounds as internal donor, as well as a process for preparing the same and use of such a procatalyst for preparing a catalyst system used in the polymerization of ethylene for producing high molecular weight polyethylenes.

Supported Ziegler-Natta ethylene polymerization procatalyst comprising special bi-(oxygen containing ring) compounds as internal donor, as well as a process for preparing the same and use of such a procatalyst for preparing a catalyst system used in the polymerization of ethylene for producing high molecular weight polyethylenes.

A method of preparing a high-purity metallocene catalyst capable of providing various selectivities and high activities for polyolefin copolymers, wherein a metallocene compound is formed by reacting a ligand compound with a zirconium compound, and then lithium chloride as a reaction by-product included in the metallocene compound is prepared in a form of a complex compound and effectively removed in a subsequent step of extracting the catalyst, thereby effectively preparing the high-purity metallocene catalyst, is provided.

A method of preparing a high-purity metallocene catalyst capable of providing various selectivities and high activities for polyolefin copolymers, wherein a metallocene compound is formed by reacting a ligand compound with a zirconium compound, and then lithium chloride as a reaction by-product included in the metallocene compound is prepared in a form of a complex compound and effectively removed in a subsequent step of extracting the catalyst, thereby effectively preparing the high-purity metallocene catalyst, is provided.

Embodiments disclosed herein include multilayer cast films having a first outer layer, a core layer, and a second outer layer, wherein the first outer layer comprises (a) a linear low density polyethylene (LLDPE), ultra-low density polyethylene (ULDPE), a first polyethylene composition, or combinations of two or more thereof, and (b) polyisobutylene, and the core layer comprises a core layer polyethylene composition.

Embodiments disclosed herein include multilayer cast films having a first outer layer, a core layer, and a second outer layer, wherein the first outer layer comprises (a) a linear low density polyethylene (LLDPE), ultra-low density polyethylene (ULDPE), a first polyethylene composition, or combinations of two or more thereof, and (b) polyisobutylene, and the core layer comprises a core layer polyethylene composition.

An ultra-high molecular weight, ultra-fine particle size polyethylene has a viscosity average molecular weight (Mv) greater than 1?10.sup.6. The polyethylene is spherical or are sphere-like particles having a mean particle size of 10-100 ?m, having a standard deviation of 2-15 ?m and a bulk density of 0.1-0.3 g/mL. Using the polyethylene as a basic polyethylene, a grafted polyethylene can be obtained by means of a solid-phase grafting method; and a glass fiber-reinforced polyethylene composition comprising the polyethylene and glass fibers, and a sheet or pipe prepared therefrom; a solubilized ultra-high molecular weight, ultra-fine particle size polyethylene; and a fiber and a film prepared from the solubilized ultra-high molecular weight, ultra-fine particle size polyethylene may also be obtained. The method has simple steps, is easy to control, has a relatively low cost and a high repeatability, and can realize industrialisation.