The present invention relates to the technical field of catalyst preparation, and discloses a preparation method of a Ziegler-Natta catalyst. The method includes the following steps: subjecting magnesium halide, alcohol and an electron donor to a first contact reaction in the presence of an inert solvent to obtain a magnesium halide alcoholate and performing first cooling; subjecting titanium halide to second cooling; subjecting the cooled titanium halide, the cooled product containing the magnesium halide alcoholate and an electron donor to a second contact reaction; filtering the product of the second contact reaction to obtain the Ziegler-Natta catalyst; and subjecting the Ziegler-Natta catalyst and the heated titanium halide to a third contact reaction. The method has the advantages such as short cycle, high efficiency, etc., being suitable to industrial production.

A Ziegler-Natta catalyst component precursor made from or containing a mechanical mixture of (a) distinct particles of adducts of formula MgCl.sub.2(R.sup.1OH).sub.n where R is a C.sub.1-C.sub.8 alkyl group and n is from 0.2 to 6 having average particle size (P50a) ranging from 5 to 100 μm; and (b) from 0.2 to 5.0% by weight of distinct particles of a solid compound containing more than 50% by weight of Sift units and having average particle size (P50b), wherein the ratio P50b/P50a ranges from 0.4 to 1.5.

Provided is a solid catalyst component for olefin polymerization comprising an electron-donating compound other than a phthalate, the solid catalyst component being equal in the olefin-polymerizing activity and in the primary physical properties of the resulting polymer such as stereoregularity and molecular weight distribution to those with use of a phthalate as an electron-donating compound. A solid catalyst component for olefin polymerization comprises a magnesium atom, a titanium atom, a halogen atom, an ester compound (A) represented by a general formula (1) and a diester compound (B) represented by a general formula (2), wherein a ratio represented by the following expression:
(content (mass %) of ester compound (A)/content (mass %) of diester compound (B))
is 0.05 to 50.

Provided is a solid catalyst component for olefin polymerization comprising an electron-donating compound other than a phthalate, the solid catalyst component being equal in the olefin-polymerizing activity and in the primary physical properties of the resulting polymer such as stereoregularity and molecular weight distribution to those with use of a phthalate as an electron-donating compound. A solid catalyst component for olefin polymerization comprises a magnesium atom, a titanium atom, a halogen atom, an ester compound (A) represented by a general formula (1) and a diester compound (B) represented by a general formula (2), wherein a ratio represented by the following expression:
(content (mass %) of ester compound (A)/content (mass %) of diester compound (B))
is 0.05 to 50.

A solid catalyst component for use in olefinic polymerization, includes titanium, magnesium, a halogen, and an internal electron donor compound; wherein: the internal electron donor compound is at least one compound represented by Formula (I)): ##STR00001##

A solid catalyst component for use in olefinic polymerization, includes titanium, magnesium, a halogen, and an internal electron donor compound; wherein: the internal electron donor compound is at least one compound represented by Formula (I)): ##STR00001##

A polypropylene-based resin composition contains: a component (A1) being a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.; and a component (A2) being a polymer selected from the group consisting of (A2-1) a propylene homopolymer, (A2-2) a random copolymer of propylene and an α-olefin having 2 or 4 to 8 carbon atoms, (A2-3) a block copolymer of propylene and an α-olefin having 2 or 4 to 8 carbon atoms, and a combination of the (A2-1), (A2-2), and (A2-3).

The resin composition has a content of the component (A1) of 0.1 to 10 wt % and a content of the component (A2) of 99.9 to 90 wt % based on the total amount of the component (A1) and the component (A2). The component (A2) has a melt flow rate (MFR) (230° C., load: 2.16 kg) of 1 to 500 g/10 min.

A polypropylene-based resin composition contains: a component (A1) being a propylene homopolymer or a copolymer of propylene and a 30 wt % or less α-olefin having 2 or 4 to 8 carbon atoms, having a intrinsic viscosity of more than 20 dl/g, as measured in a tetralin solvent at 135° C.; and a component (A2) being a polymer selected from the group consisting of (A2-1) a propylene homopolymer, (A2-2) a random copolymer of propylene and an α-olefin having 2 or 4 to 8 carbon atoms, (A2-3) a block copolymer of propylene and an α-olefin having 2 or 4 to 8 carbon atoms, and a combination of the (A2-1), (A2-2), and (A2-3).

The resin composition has a content of the component (A1) of 0.1 to 10 wt % and a content of the component (A2) of 99.9 to 90 wt % based on the total amount of the component (A1) and the component (A2). The component (A2) has a melt flow rate (MFR) (230° C., load: 2.16 kg) of 1 to 500 g/10 min.

A modified spray-dried Ziegler-Natta (pro)catalyst system comprising a Ziegler-Natta (pro)catalyst, a carrier material, and a tetrahydrofuran/ethanol modifier; polyolefins; methods of making and using same; and articles containing same.

An activated, titanium-based, spray-dried Ziegler-Natta catalyst system containing a titanium-based Ziegler-Natta catalyst, a carrier material, and an activator mixture comprising an effective amount of an activator mixture comprising triethylaluminum and diethylaluminum chloride for producing a substantially uniform comonomer composition distribution. Also, polyolefins; methods of making and using same; and articles containing same.