A catalyst component comprising Ti, Mg, Cl, and an electron donor compound having porosity of at least 0.2 cm.sup.3/g and characterized by the fact that it further comprises Cu oxide, with the proviso that when the electron donor compound is selected from esters of phthalic acids, the porosity is of at least 0.45 cm.sup.3/g.

A solid catalyst component for the polymerization of olefins made from or containing Mg, Ti, halogen and an electron donor of formula (I) or (II) ##STR00001## When activated with an aluminum alkyl and optionally an external electron donor, solid catalyst component can give high activity and stereospecificity in the polymerization of olefins.

The present disclosure provides a heterogeneous Ziegler-Natta catalyst system to be used in the preparation of ultra-high molecular weight polymers (UHMWP). The system includes at least one procatalyst, at least one co-catalyst, at least one hydrocarbon medium and at least one external donor, wherein the ratio of elemental magnesium to elemental titanium to halide, in the procatalyst, is 1:1.3:3.7; the ratio of elemental aluminum, present in the co-catalyst to elemental titanium, present in the procatalyst, ranges between 6:1 and 12:1; and the ratio of elemental silicon, present in the external donor to elemental titanium, present in the procatalyst, ranges between 1:10 and 10:1. The present disclosure also provides a process for preparation of UHMWPE using the heterogeneous Ziegler-Natta catalyst system of the present disclosure.

Catalyst systems containing a Ziegler-Natta catalyst component are disclosed. Such catalyst systems can contain a co-catalyst and a supported catalyst containing a fluorided silica-coated alumina, a magnesium compound, and vanadium and/or tetravalent titanium.

A process for the preparation of a propylene copolymer, preferably a heterophasic propylene copolymer, in a multistage polymerisation process in the presence of a single site catalyst, said process comprising: (I) in a slurry polymerisation step, polymerising propylene and optionally at least one C2-10 alpha olefin comonomer; and subsequently (II) in a gas polymerisation step polymerising propylene and optionally at least one C2-10 alpha olefin comonomer, in the presence of catalyst and polymer from step (I); (III) in a second gas polymerisation step, polymerising propylene and at least one C2-10 alpha olefin comonomer in the presence of the catalyst and polymer from step (II); wherein said catalyst comprises (i) a metallocene complex of a group (IV) metal, said metallocene comprising at least two cyclopentadienyl type ligands; (ii) a boron based cocatalyst; and (iii) an aluminoxane cocatalyst; said catalyst being in solid form, preferably in solid particulate form, and being free from an external carrier.

Catalyst systems containing a Ziegler-Natta catalyst component are disclosed. Such catalyst systems can contain a co-catalyst and a supported catalyst containing a fluorided silica-coated alumina, a magnesium compound, and vanadium and/or tetravalent titanium.

This present invention relates to a method for using halogenation agents to react with magnesium precursor or with magnesium complexes to form catalyst components without using internal electron donors. The catalyst components are used to produce polypropylene with good productivity and high stereospecificity. This method offers a wide range of catalyst component preparations and selections to enhance the catalyst component applications regarding activity, stereospecificity, hydrogen response, molecular weight, and distributions.

Provided is a production method for an olefin-based polymer, including polymerizing an olefin raw material using (A) a transition metal compound, (B) a boron compound capable of forming an ion pair with the component (A), (C) a specific organoaluminum compound, and (D) a specific aluminoxane in presence of at least one or more kinds of (N) a nonpolymerizable unsaturated hydrocarbon in the olefin raw material or a polymerization solvent.

Polymerization process control methods for making polyethylene are provided. The process control methods include performing a polymerization reaction in a polymerization reactor to produce the polyethylene, where ethylene, and optionally one or more comonomers, in the polymerization reaction is catalyzed by an electron donor-free Ziegler-Natta catalyst and an alkyl aluminum co-catalyst. A melt flow ratio (I.sub.21/I.sub.2) of the polyethylene removed from the polymerization reactor is measured and an amount of long chain branching (LCB) of the polyethylene from the polymerization reactor is controlled by adjusting a weight concentration of the alkyl aluminum co-catalyst present in the polymerization reactor. In addition, an electron donor-free Ziegler-Natta catalyst productivity of the polyethylene being produced in the polymerization reactor is measured from which the amount of LCB of the polyethylene from the polymerization reactor is determined using the measured electron donor-free Ziegler-Natta catalyst productivity and a predetermined relationship between the electron donor-free Ziegler-Natta catalyst productivity and the LCB.