A polyethylene fiber wherein when a free induction decay (M(t)) of the polyethylene fiber at 90 C. measured by a pulsed nuclear magnetic resonance (NMR) solid echo method is approximated to three components of a component () having a lowest mobility, a component () having an intermediate mobility, and a component () having a highest mobility, by fitting using formula 1 (M(t)= exp(()(t/T.sub.).sup.2)sin bt/bt+ exp((1/Wa)(t/T.sub.).sup.Wa)+ exp(t/T.sub.)), a composition fraction of the component () having the highest mobility is 1% or more and 10% or less, and a relaxation time of the component () having the highest mobility is 100 s or more and 1000 s or less.

Methods of preparing a polymerization catalyst component is provided, in which a magnesium component, a Lewis acid solubilizing component, a titanium compound, optionally a transition metal compound different than the titanium compound, and typically an inert filler are combined in a slurrying agent and spray-dried to produce a catalyst precursor in the form of a substantially spherical and porous solid particle. The methods and catalysts of this disclosure can provide ethylene homopolymer and copolymer resins having a high molecular weight tail and a broadened molecular weight distribution as compared to more traditional Ziegler-Natta catalysts.

Methods of preparing a polymerization catalyst component is provided, in which a magnesium component, a Lewis acid solubilizing component, a titanium compound, optionally a transition metal compound different than the titanium compound, and typically an inert filler are combined in a slurrying agent and spray-dried to produce a catalyst precursor in the form of a substantially spherical and porous solid particle. The methods and catalysts of this disclosure can provide ethylene homopolymer and copolymer resins having a high molecular weight tail and a broadened molecular weight distribution as compared to more traditional Ziegler-Natta catalysts.

A process of preparing a solid catalyst component for the production of polypropylene includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

A process of preparing a solid catalyst component for the production of polypropylene includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

A process for the preparation of a solid catalyst component for the homo or copolymerization of olefins, wherein the solid catalyst component is made from or contains Mg, Ti, halogen and an electron donor selected from cycloalkyl ethers, wherein the process includes the steps of (a) dissolving a Mg based compound and a TiCl.sub.3 based compound in a liquid medium further made from or containing a cycloalkyl ether and a compound of formula R.sup.2OH where R.sup.2 is a C.sub.1-C.sub.20 hydrocarbon group, in which the Ti/Mg molar ratio ranges from 0.1 to 0.5, the cycloalkyl ether/Mg ratio ranges from 1 to 4 and the ROH/Mg molar ratio ranges from 1 to 4; and (b) adding, to the solution coming from step (a), SiCl.sub.4 in an amount such that the R.sup.2OH/SiCl.sub.4 molar ratio ranges from 0.5 to 1.5 and maintaining the temperature in the range 50-150 C. thereby precipitating the solid catalyst component particles.

A process for the preparation of a solid catalyst component for the homo or copolymerization of olefins, wherein the solid catalyst component is made from or contains Mg, Ti, halogen and an electron donor selected from cycloalkyl ethers, wherein the process includes the steps of (a) dissolving a Mg based compound and a TiCl.sub.3 based compound in a liquid medium further made from or containing a cycloalkyl ether and a compound of formula R.sup.2OH where R.sup.2 is a C.sub.1-C.sub.20 hydrocarbon group, in which the Ti/Mg molar ratio ranges from 0.1 to 0.5, the cycloalkyl ether/Mg ratio ranges from 1 to 4 and the ROH/Mg molar ratio ranges from 1 to 4; and (b) adding, to the solution coming from step (a), SiCl.sub.4 in an amount such that the R.sup.2OH/SiCl.sub.4 molar ratio ranges from 0.5 to 1.5 and maintaining the temperature in the range 50-150 C. thereby precipitating the solid catalyst component particles.

The present disclosure is generally directed to polyolefin polymers, such as polypropylene homopolymers, and propylene-ethylene copolymers that have improved flow properties. In one embodiment, the polymers can be produced using a solid catalyst component that includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

The present disclosure is generally directed to polyolefin polymers, such as polypropylene homopolymers, and propylene-ethylene copolymers that have improved flow properties. In one embodiment, the polymers can be produced using a solid catalyst component that includes a) dissolving a halide-containing magnesium compound in a mixture, the mixture including an epoxy compound, an organic phosphorus compound, and a hydrocarbon solvent to form a homogenous solution; b) treating the homogenous solution with an organosilicon compound during or after the dissolving step; c) treating the homogenous solution with a first titanium compound in the presence of a first non-phthalate electron donor, and an organosilicon compound, to form a solid precipitate; and d) treating the solid precipitate with a second titanium compound in the presence of a second non-phthalate electron donor to form the solid catalyst component, where the process is free of carboxylic acids and anhydrides.

A process for preparing a solid pre-catalyst component for use in olefinic polymerization includes dissolving a magnesium chloride in an alcohol and optionally adding water to form a first solution having a water content of about 0.5 mmol water per mol MgCl.sub.2 to about 100 mmol water per mol MgCl.sub.2; contacting the first solution with a first titanium compound to form the solid pre-catalyst component; and treating the solid pre-catalyst component with a hydrocarbon or halogenated hydrocarbon solvent, optionally containing a second titanium compound.