The present invention relates to a polyethylene homo- or copolymer having improved wear properties. In particular, the invention relates to an ultra-high molecular weight polyethylene having improved wear properties prepared using a heterogeneous Ziegler catalyst system. Said polyethylene homo- or copolymer is characterized in that the abrasion index of said polyethylene is related to the elongational stress according to the formula (I): in which ES=elongational stress as measured according to ISO 11542-2:1998 AI=abrasion index, as measured according to ISO 15527:2010 where the reference material according to ISO 15527:2010 is set to 100; β<1.8; and −0.015<a<−0.017.

[00001]$\begin{array}{cc}\mathrm{AI}<\frac{\mathrm{ES}-\beta }{\alpha }& \left(I\right)\end{array}$

A process for the preparation of a propylene polymer containing a coloring agent in an amount ranging from 0.2 to 30 ppm referred to the weight of propylene polymer, including the steps of: a) providing a solid ZN catalyst component made from or containing Mg, Ti, halogen and an internal electron donor compound, wherein the Ti being in an amount ranging from 0.1 to 10% of the total weight of solid catalyst component; b) providing a coloring agent made from or containing at least a pigment; c) mixing the ZN catalyst particles and the coloring agent in a liquid hydrocarbon medium, thereby obtaining a slurry and d) feeding the slurry to a polymerization reactor and subjecting the reactor to polymerization conditions, thereby yielding the propylene polymer.

A process for the preparation of a propylene polymer containing a coloring agent in an amount ranging from 0.2 to 30 ppm referred to the weight of propylene polymer, including the steps of: a) providing a solid ZN catalyst component made from or containing Mg, Ti, halogen and an internal electron donor compound, wherein the Ti being in an amount ranging from 0.1 to 10% of the total weight of solid catalyst component; b) providing a coloring agent made from or containing at least a pigment; c) mixing the ZN catalyst particles and the coloring agent in a liquid hydrocarbon medium, thereby obtaining a slurry and d) feeding the slurry to a polymerization reactor and subjecting the reactor to polymerization conditions, thereby yielding the propylene polymer.

The present disclosure provides processes for polymerizing olefin(s). Methods can include combining a catalyst component slurry with a catalyst component solution to form a third catalyst composition and introducing the third composition into a polymerization reactor. The present disclosure further provides methods for preparing catalyst component slurries, catalyst component solutions, and the third catalyst compositions. In at least one embodiment, a method includes contacting a first composition and a second composition in a line to form a third composition, the first composition including a contact product of a first catalyst, a second catalyst, a support, an activator, a mineral oil, and a wax, and the second composition comprising a contact product of an activator, a diluent, and the first catalyst or second catalyst. The method includes introducing the third composition from the line into a gas-phase fluidized bed reactor, exposing the third composition to polymerization conditions, and obtaining a polyolefin.

The present disclosure provides processes for polymerizing olefin(s). Methods can include combining a catalyst component slurry with a catalyst component solution to form a third catalyst composition and introducing the third composition into a polymerization reactor. The present disclosure further provides methods for preparing catalyst component slurries, catalyst component solutions, and the third catalyst compositions. In at least one embodiment, a method includes contacting a first composition and a second composition in a line to form a third composition, the first composition including a contact product of a first catalyst, a second catalyst, a support, an activator, a mineral oil, and a wax, and the second composition comprising a contact product of an activator, a diluent, and the first catalyst or second catalyst. The method includes introducing the third composition from the line into a gas-phase fluidized bed reactor, exposing the third composition to polymerization conditions, and obtaining a polyolefin.

The Zigler-Natta catalyst composition of the present disclosure provides uniform polyethylene having a molecular weight in the range from 1 million g/mol to 12 million g/mol. The Zigler-Natta catalyst composition of the present disclosure comprises external electron donor selected from the group consisting of substituted silanediyl diacetate, trialkyl borate and tetraalkoxysilane.

The Zigler-Natta catalyst composition of the present disclosure provides uniform polyethylene having a molecular weight in the range from 1 million g/mol to 12 million g/mol. The Zigler-Natta catalyst composition of the present disclosure comprises external electron donor selected from the group consisting of substituted silanediyl diacetate, trialkyl borate and tetraalkoxysilane.

The present invention relates to a process for preparing a procatalyst for polymerization of olefins, said process comprising contacting a magnesium-containing support with a halogen-containing titanium compound, an internal electron donor being a substituted 1,2-phenylene aromatic diester compound.

The present invention relates to a process for preparing a procatalyst for polymerization of olefins, said process comprising contacting a magnesium-containing support with a halogen-containing titanium compound, an internal electron donor being a substituted 1,2-phenylene aromatic diester compound.

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.