The invention relates to a process for preparing a solid support for a procatalyst suitable for preparing a catalyst composition for olefin polymerization, said process for preparing said solid support comprising reacting a compound R.sup.4.sub.zMgX.sup.4.sub.2-z with a silane compound Si(OR.sup.5).sub.4-n(R.sup.6).sub.n in a solvent and mixing the resulting mixture with a mixing device and at a certain mixing speed in order to give a solid support Mg(OR.sup.1).sub.xX.sup.1.sub.2-x said solid support obtained having an average particle size of at most 17 μm, preferably at most 16 or 14 μm, more preferably at most 12 μm. The invention further relates to a solid support, a process for preparing a procatalyst and said procatalyst as well as polyolefins obtained using said procatalyst.

The present disclosure provides a gas-phase polymerization process for preparing polyethylene, wherein halogenated alcohols in combination with a Ti based catalyst component and aluminum alkyls as co-catalyst suppress ethane formation or increase polymerization activity.

The present disclosure provides a gas-phase polymerization process for preparing polyethylene, wherein halogenated alcohols in combination with a Ti based catalyst component and aluminum alkyls as co-catalyst suppress ethane formation or increase polymerization activity.

A pipe including polyethylene produced in the presence of a solid catalyst and a co-catalyst, wherein the solid catalyst is prepared by the steps of: (a) contacting a dehydrated support having hydroxyl groups with a compound of formula MgR.sup.1R.sup.2; (b) contacting the product of step (a) with modifying compounds (A), (B) and (C), wherein: (A) is carboxylic acid, carboxylic acid ester, ketone, acyl halide, aldehyde or alcohol; (B) is of formula R.sup.11.sub.f(R.sup.12O).sub.gSiX.sub.h wherein f, g and h 0 to 4 and the sum of f, g and h=4 provided that when h=4 then compound (A) is not an alcohol; (C) is a compound of formula (R.sup.13O).sub.4M, wherein M is a titanium atom, a zirconium atom or a vanadium atom; and (c) contacting the product of step (b) with a titanium halide TiX.sub.4, whereby the polyethylene has a molecular weight of 720,000 to less than 2,500,000 g/mol.

A pipe including polyethylene produced in the presence of a solid catalyst and a co-catalyst, wherein the solid catalyst is prepared by the steps of: (a) contacting a dehydrated support having hydroxyl groups with a compound of formula MgR.sup.1R.sup.2; (b) contacting the product of step (a) with modifying compounds (A), (B) and (C), wherein: (A) is carboxylic acid, carboxylic acid ester, ketone, acyl halide, aldehyde or alcohol; (B) is of formula R.sup.11.sub.f(R.sup.12O).sub.gSiX.sub.h wherein f, g and h 0 to 4 and the sum of f, g and h=4 provided that when h=4 then compound (A) is not an alcohol; (C) is a compound of formula (R.sup.13O).sub.4M, wherein M is a titanium atom, a zirconium atom or a vanadium atom; and (c) contacting the product of step (b) with a titanium halide TiX.sub.4, whereby the polyethylene has a molecular weight of 720,000 to less than 2,500,000 g/mol.

Provided is a solid catalyst component for olefin polymerization, which comprises Mg, Ti, a halogen and an electron donor. The electron donor is selected from at least one of ring-substituted ether-acid ester compounds of the general formula (I). Also provided are a catalyst containing the solid catalyst component and the application of the catalyst in reactions of olefin polymerization, particularly in the reaction of propylene polymerization.

Provided is a solid catalyst component for olefin polymerization, which comprises Mg, Ti, a halogen and an electron donor. The electron donor is selected from at least one of ring-substituted ether-acid ester compounds of the general formula (I). Also provided are a catalyst containing the solid catalyst component and the application of the catalyst in reactions of olefin polymerization, particularly in the reaction of propylene polymerization.

The present disclosure relates to a porous solid adduct comprising magnesium chloride and ethanol, characterized by a relationship between the content of alcohol, average pore radius and amount of porosity deriving from pores with radii of 100-1000 nm, and catalyst components produced therefrom that are capable of producing polyolefins with increased porosity.

The present disclosure relates to a porous solid adduct comprising magnesium chloride and ethanol, characterized by a relationship between the content of alcohol, average pore radius and amount of porosity deriving from pores with radii of 100-1000 nm, and catalyst components produced therefrom that are capable of producing polyolefins with increased porosity.

The invention relates to a continuous process for the production of ultra-high molecular weight polyethylene with an Elongational Stress of at least 0.43 N/mm.sup.2. The polymerisation of ethylene takes place in the presence of a catalyst and hydrogen. It is an advantage of the process according to the invention that the use of small amounts of hydrogen during the production of UHM-WPE reduces reactor fouling. Furthermore, the process according to the invention results in longer run times in polymerization reactors, less cleaning cycles to remove reactor fouling and in less need for other anti-fouling agents or anti-static agents.