The invention relates to the technical field of heterogeneous catalytic olefin polymerization, and discloses a polyolefin catalyst, its preparation and its us. A method for preparing the polyolefin catalyst comprises: (i) providing a thermally activated mesoporous material, with the thermal activation treatment being performed at a temperature of 300 to 900° C. for a period of time of 3 to 48 hours; (ii) under an inert atmosphere, (iia) conducting impregnation treatment of the thermally activated mesoporous material with a solution containing a magnesium component and then with a solution containing a titanium component, (iib) conducting impregnation treatment of the thermally activated mesoporous material with a solution containing a titanium component and then with a solution containing a magnesium component, or (iic) conducting co-impregnation treatment of the thermally activated mesoporous material with a solution containing both a titanium component and a magnesium component, to obtain a slurry to be sprayed; and (iii) spray drying the slurry to be sprayed from step (ii), to obtain a solid polyolefin catalyst component. When used in olefin polymerization, the polyolefin catalysts prepared by using the method provided by the invention have high catalytic activities, and polyolefin products having a narrow molecular weight distribution and an excellent melt index can be obtained.

Methods for the production of heterophasic polymers in gas and slurry phase polymerization processes, and polymer compositions made therefrom, are disclosed herein.

The present invention relates to a process for the preparation of a procatalyst suitable for preparing a catalyst composition for olefin polymerization, said process comprising the steps of: Step A) providing or preparing a Grignard compound; Step B) contacting the Grignard compound an alkoxy- or aryloxy silane compound, to give a solid support; Step C) optionally contacting the solid support obtained with at least one activating compound; and Step D) reacting the (activated) support with a halogen-containing Ti-compound as catalytic species, an activator and at least one internal electron donor in several sub steps wherein the internal donor is added in portions during at least two of said stages to obtain a procatalyst. The invention moreover relates to a procatalyst, a catalytic system comprising said procatalyst and to a process to prepare polyolefins using said catalyst system and the polyolefins obtained therewith.

A carrier for an olefin polymerization catalyst contains a magnesium-containing compound and sulfur. The sulfur is at least one of an elemental sulfur, a complex sulfur, and a compound sulfur. The carrier has good particle morphology and a smooth surface, and has a narrow particle size distribution. The catalyst prepared from the carrier has high activity and good sensitivity to hydrogen regulation, and can improve the density of a polymer stack when being used for olefin polymerization.

The present invention is directed to a polyolefin composition comprising a blend of a heterophasic polypropylene composition and 5.0 to 30.0 wt % of an ethylene homo- or copolymer, the ethylene homo- or copolymer having a density of at least 941 kg/m.sup.3 and a melt flow rate MFR.sub.21 of 1 to 10 g/10 min. The heterophasic polypropylene composition comprises a propylene homopolymer or a propylene ethylene random copolymer and an elastomeric ethylene propylene rubber, and is characterized by 75.0 to 95.0 wt % of a crystalline fraction having an ethylene content of up to 4.0 wt % and an MFR.sub.2 of 0.1 to 100 g/10 min, and 5.0 to 25.0 wt % of a soluble fraction having an ethylene content of 10.0 to 70.0 wt % and an intrinsic viscosity of 1.0 to 4.0 dl/kg, wherein the crystalline fraction and the soluble fraction are determined in 1,2,4-trichlorobenzene at 40° C.

The present invention relates to a catalyst system for producing ethylene copolymers in a high temperature solution process, the catalyst system comprising (i) a metallocene complex of a group 4 transition metal comprising at least one ligand selected from optionally substituted cyclopentadienyl (Cp), indenyl (Ind) and fluorenyl (Flu) ligands and (ii) a solid alkyl aluminium oxide cocatalyst The invention relates also to the preparation of the catalyst system, use thereof in the high temperature solution process and to a process comprising polymerizing ethylene and a C.sub.4-10 alpha-olefin comonomer in a high temperature solution process in the presence of the catalyst system.

Catalyst preparation systems and methods for preparing reduced chromium catalysts are disclosed, and can comprise irradiating a supported chromium catalyst containing hexavalent chromium with a light beam having a wavelength within the UV-visible light spectrum. Such reduced chromium catalysts have improved catalytic activity compared to chromium catalysts reduced by other means. The use of the reduced chromium catalyst in polymerization reactor systems and olefin polymerization processes also is disclosed, resulting in polymers with a higher melt index.

Disclosed are support-activators and catalyst compositions comprising the support-activators for polymerizing olefins in which the support-activator includes clay heteroadduct, prepare from a colloidal phyllosilicate such as a colloidal smectite clay, which is chemically-modified with a heterocoagulation agent. By limiting the amount of heterocoagulation reagent relative to the colloidal smectite clay as described herein, the smectite heteroadduct support-activator is a porous and amorphous solid which can be readily isolated from the resulting slurry by a conventional filtration process, and which can activate metallocenes and related catalysts toward olefin polymerization. Related compositions and processes are disclosed.

Disclosed herein are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with an inorganic base to form an aqueous mixture having a pH of at least 4, followed by contacting a solid oxide with the aqueous mixture to produce the fluorided solid oxide. Also disclosed are methods for preparing fluorided solid oxides by contacting an acidic fluorine-containing compound with a solid oxide to produce a mixture, followed by contacting the mixture with a inorganic base to produce the fluorided solid oxide at a pH of at least about 4. The fluorided solid oxide can be used as an activator component in a catalyst system for the polymerization of olefins.

A composition, such as a catalyst precursor or a catalyst comprising a Cr coated silica support with particularly defined levels of Na and Al, such that the resulting Cr/Silica catalyst has an increased MI potential is disclosed. In an embodiment, the disclosed catalyst composition comprises a silica-containing substrate made using a base-set gel and comprising a catalytically active metal consisting of Cr, with Al impurities of less than 50 ppm and Na in an amount of less than 800 ppm of the catalyst composition. The disclosed composition has an increased MI potential over a catalyst having higher Al content, a lower Na:Al ratio, or both. Methods of making the disclosed composition, and methods of using it to prepare a polyethylene are also disclosed.