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.

The present invention relates to a process for preparing a solid catalyst component suitable for producing polyethylene and its copolymers, said process comprising the steps of: (a) contacting a dehydrated support having hydroxyl groups with a magnesium compound having the general formula MgR.sup.1R.sup.2; (b) contacting the product obtained in step (a) with modifying compounds (A) and/or (B) and/or (C), wherein: (A) is at least one oxygen and/or nitrogen comprising organic compound; (B) is a compound having the general formula R.sup.11.sub.f(R.sup.12O).sub.gSiX.sub.h, (C) is a compound having the general formula (R.sup.13O).sub.4M, and (c) contacting the product obtained in step (b) with a titanium halide compound having the general formula TiX.sub.4, wherein Ti is a titanium atom and X is a halide atom, wherein an organometallic compound is added either before step (a) and/or after step (c). The invention also relates to a solid catalyst component obtainable by said process. The invention further relates to a process for producing polyethylene and its copolymers in the presence of the solid catalyst component and a co-catalyst.

The present invention relates to a process for preparing a solid catalyst component suitable for producing polyethylene and its copolymers, said process comprising the steps of: (a) contacting a dehydrated support having hydroxyl groups with a magnesium compound having the general formula MgR.sup.1R.sup.2; (b) contacting the product obtained in step (a) with modifying compounds (A) and/or (B) and/or (C), wherein: (A) is at least one oxygen and/or nitrogen comprising organic compound; (B) is a compound having the general formula R.sup.11.sub.f(R.sup.12O).sub.gSiX.sub.h, (C) is a compound having the general formula (R.sup.13O).sub.4M, and (c) contacting the product obtained in step (b) with a titanium halide compound having the general formula TiX.sub.4, wherein Ti is a titanium atom and X is a halide atom, wherein an organometallic compound is added either before step (a) and/or after step (c). The invention also relates to a solid catalyst component obtainable by said process. The invention further relates to a process for producing polyethylene and its copolymers in the presence of the solid catalyst component and a co-catalyst.

The present invention provides an ethylene polymer having a viscosity average molecular weight of 10010.sup.4 or more and 1,00010.sup.4 or less, in which a ratio between an isothermal crystallization time at 125 C. and an isothermal crystallization time at 123 C. obtained under specific isothermal crystallization time measurement conditions is 3.5 or more and 10.0 or less, and a degree of crystallization obtained using a differential scanning calorimeter (DSC) is 40% or more and 75% or less.

The present invention provides an ethylene polymer having a viscosity average molecular weight of 10010.sup.4 or more and 1,00010.sup.4 or less, in which a ratio between an isothermal crystallization time at 125 C. and an isothermal crystallization time at 123 C. obtained under specific isothermal crystallization time measurement conditions is 3.5 or more and 10.0 or less, and a degree of crystallization obtained using a differential scanning calorimeter (DSC) is 40% or more and 75% or less.

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.

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.

A method for producing a solid catalyst component (Aa) for -olefin polymerization, which includes: bringing components (A1) to (A4) into contact with one another in an inert solvent; and without washing the contact product with an inert solvent, aging the contact product by keeping for a holding time of 3 days or more and 180 days or less, regarding the time point that all of the components (A1) to (A4) first come into contact, as a starting point.

A method for producing a solid catalyst component (Aa) for -olefin polymerization, which includes: bringing components (A1) to (A4) into contact with one another in an inert solvent; and without washing the contact product with an inert solvent, aging the contact product by keeping for a holding time of 3 days or more and 180 days or less, regarding the time point that all of the components (A1) to (A4) first come into contact, as a starting point.

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.