The present invention is directed to a propylene polymer composition comprising at least one propylene copolymer (C-PP), and an α-nucleating agent (NU), wherein the propylene copolymer (C-PP) comprises two propylene copolymer fractions (PP1) and (PP2), wherein propylene copolymer fraction (PP1) is contained in the propylene copolymer (C-PP) in an amount of 30 to 70 wt. % and the propylene copolymer fraction (PP2) is contained in the propylene copolymer (C-PP) in an amount of 70 to 30 wt. %, the comonomer content of propylene copolymer fraction (PP1) is in the range of 0.5 to 2.5 wt.-% and the comonomer content of the propylene copolymer fraction (PP1) is lower compared to the comonomer content of the propylene copolymer fraction (PP2), and the propylene polymer composition has (a) a melt flow rate MFR.sub.2 (230° C.) measured according to according to ISO 1133 of 1 to 5 g/10 min., and (b) a comonomer content of 4.0 to 8.0 wt. %, the comonomer(s) being ethylene and/or at least one C.sub.4 to C.sub.12 α-olefin. The above propylene polymer composition has improved impact and optical properties. The invention further provides a method of producing the above propylene polymer composition and an extrusion blow molded article comprising the above propylene polymer composition.

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. A solid catalyst component for polymerization of an olefin is obtained by: (i) bringing compounds selected from particular phthalic acid ester compounds (A), a magnesium compound and a halogen-containing titanium compound into contact; (ii) bringing the first contact product obtained in step (i) and compounds selected from particular diether compounds (B) into contact, and washing the second contact product; and (iii) obtaining a contact product between the washed second contact product and a halogen-containing titanium compound, washing the contact product, and bringing it into contact with particular phthalic acid ester compounds (A) and a halogen-containing titanium compound.

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. A solid catalyst component for polymerization of an olefin is obtained by: (i) bringing compounds selected from particular phthalic acid ester compounds (A), a magnesium compound and a halogen-containing titanium compound into contact; (ii) bringing the first contact product obtained in step (i) and compounds selected from particular diether compounds (B) into contact, and washing the second contact product; and (iii) obtaining a contact product between the washed second contact product and a halogen-containing titanium compound, washing the contact product, and bringing it into contact with particular phthalic acid ester compounds (A) and a halogen-containing titanium compound.

Provided is an alkoxy magnesium supported olefin polymerization catalyst component, comprising the reaction products of the following components: at least one alkoxy magnesium compound of Mg(OR1′)N(OR2′)2-N, at least one titanium compound of general formula Ti(OR)nX4-n, at least one ortho-phenylene diester electron donor compound a, and at least one diether electron donor compound b, wherein the molar ratio of a to b is 0.05 to 20. The catalyst component has an ultrahigh polymerization activity when used for olefin polymerization, and does not require the use of an external electron donor, but can also obtain a polymer with a high isotacticity, and the resulting polymer has a relatively wide molecular weight distribution and a relatively low ash content.

Provided is an alkoxy magnesium supported olefin polymerization catalyst component, comprising the reaction products of the following components: at least one alkoxy magnesium compound of Mg(OR1′)N(OR2′)2-N, at least one titanium compound of general formula Ti(OR)nX4-n, at least one ortho-phenylene diester electron donor compound a, and at least one diether electron donor compound b, wherein the molar ratio of a to b is 0.05 to 20. The catalyst component has an ultrahigh polymerization activity when used for olefin polymerization, and does not require the use of an external electron donor, but can also obtain a polymer with a high isotacticity, and the resulting polymer has a relatively wide molecular weight distribution and a relatively low ash content.

Catalyst composition comprising a phthalate-free electron donor, which is highly effective during polymerisation in the presence of a polymeric nucleating agent, and its use and a process for its preparation.

Catalyst composition comprising a phthalate-free electron donor, which is highly effective during polymerisation in the presence of a polymeric nucleating agent, and its use and a process for its preparation.

A magnesium alkoxide catalyst support and the preparation method and use thereof are provided. The method for preparing the magnesium alkoxide catalyst support comprises the following steps: mixing a metallic magnesium, a monohydric alcohol, a halogenating agent and a surfactant at 0° C. to 90° C. under an inert gas atmosphere, and then washing the resultant with an inert solvent to obtain the magnesium alkoxide catalyst support. A magnesium alkoxide catalyst support obtained by the above method is also provided, which can be used to catalyze olefin polymerization. The magnesium alkoxide catalyst support obtained by the above method according to the invention has excellent particle morphology and controllable size, and is suitable for preparing a catalyst for olefin polymerization.

A magnesium alkoxide catalyst support and the preparation method and use thereof are provided. The method for preparing the magnesium alkoxide catalyst support comprises the following steps: mixing a metallic magnesium, a monohydric alcohol, a halogenating agent and a surfactant at 0° C. to 90° C. under an inert gas atmosphere, and then washing the resultant with an inert solvent to obtain the magnesium alkoxide catalyst support. A magnesium alkoxide catalyst support obtained by the above method is also provided, which can be used to catalyze olefin polymerization. The magnesium alkoxide catalyst support obtained by the above method according to the invention has excellent particle morphology and controllable size, and is suitable for preparing a catalyst for olefin polymerization.

A method capable of stably performing continuous production of a propylene polymer with high productivity while reducing generation of agglomerates is described. In the method, a monomer(s) containing propylene is/are (co)polymerized in a presence of an olefin polymerization catalyst with a polymerization system containing two or more gas phase polymerization reactors or a polymerization system containing a liquid phase polymerization reactor(s) and a gas phase polymerization reactor(s) such that that the total number of liquid phase polymerization reactor(s) and gas phase polymerization reactor(s) is three or more. In at least one gas phase polymerization reactor, an average retention time τ.sub.G [hour] in the gas phase polymerization, an average particle diameter D.sub.pi [μm] of fed powder, and a total amount C.sub.o [wt %] of an ethylene-derived structural unit and C4-C12 α-olefin-derived structural units in a polymer in discharged powder are in a predetermined relationship.