A polyethylene powder having a limiting viscosity [?] of 2.0 dl/g or more and less than 20.0 dl/g as measured in decalin at 135? C., wherein the polyethylene powder presents a percentage decrease from a specific surface area A measured by the BET method before heating at 120? C. for 5 h to a specific surface area B measured by a BET method after heating at 120? C. for 5 h, ((A?B)/A?100), of 0.1% or more and less than 35%.

A polyethylene powder having a limiting viscosity [?] of 2.0 dl/g or more and less than 20.0 dl/g as measured in decalin at 135? C., wherein the polyethylene powder presents a percentage decrease from a specific surface area A measured by the BET method before heating at 120? C. for 5 h to a specific surface area B measured by a BET method after heating at 120? C. for 5 h, ((A?B)/A?100), of 0.1% or more and less than 35%.

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 invention presents an ethylene polymer, wherein the ethylene polymer has a weight average molecular weight (Mw) of 200,000 or more and 3,000,000 or less, a proportion of a component (130) with the lowest mobility of 40% or more and 60% or less, and a ratio / of a middle motion component () to a component () with the highest mobility of 1.0 or more and 4.0 or less when a three-component approximation of free induction decay at 130 C. measured by a solid echo method of pulse NMR is performed.

The present invention presents an ethylene polymer, wherein the ethylene polymer has a weight average molecular weight (Mw) of 200,000 or more and 3,000,000 or less, a proportion of a component (130) with the lowest mobility of 40% or more and 60% or less, and a ratio / of a middle motion component () to a component () with the highest mobility of 1.0 or more and 4.0 or less when a three-component approximation of free induction decay at 130 C. measured by a solid echo method of pulse NMR is performed.

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.

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.