A heterophasic copolymer composition obtained by a process comprising polymerising in multiple steps and multiple polymerisation reactors propylene monomer and a comonomer selected from ethylene, alpha-olefins having 4 to 10 carbon atoms and their mixtures, in the presence of an olefin polymerisation catalyst comprising a solid catalyst component and a co-catalyst, wherein the solid catalyst component comprises titanium, magnesium, halogen and an internal donor of the formula (I):

##STR00001##

wherein R.sub.1 and R.sub.2 are the same or different being a linear or branched C.sub.1-C.sub.12-alkyl group and R is hydrogen or a linear, branched or cyclic C.sub.1 to C.sub.12-alkyl.

Embodiments of polyethylene compositions and articles comprising polyethylene compositions are disclosed. The polyethylene compositions may include a first polyethylene fraction area defined by an area in the elution profile in a temperature range of 70° C. to 97° C. via improved comonomer composition distribution (iCCD) analysis method; a first peak in the temperature range of 70° C. to 97° C. in the elution profile; a second polyethylene fraction area defined by an area in the elution profile in a temperature range of 97° C. to 110° C.; and a second peak in the temperature range of 97° C. to 110° C. The polyethylene composition may have a density of 0.935 g/cm.sup.3 to 0.955 g/cm.sup.3 and a melt index (I.sub.2) of 1.0 g/10 minutes to 10.0 g/10 minutes. A ratio of the first polyethylene fraction area to the second polyethylene fraction area may be less than 2.0.

Embodiments of polyethylene compositions and articles comprising polyethylene compositions are disclosed. The polyethylene compositions may include a first polyethylene fraction area defined by an area in the elution profile in a temperature range of 70° C. to 97° C. via improved comonomer composition distribution (iCCD) analysis method; a first peak in the temperature range of 70° C. to 97° C. in the elution profile; a second polyethylene fraction area defined by an area in the elution profile in a temperature range of 97° C. to 110° C.; and a second peak in the temperature range of 97° C. to 110° C. The polyethylene composition may have a density of 0.935 g/cm.sup.3 to 0.955 g/cm.sup.3 and a melt index (I.sub.2) of 1.0 g/10 minutes to 10.0 g/10 minutes. A ratio of the first polyethylene fraction area to the second polyethylene fraction area may be less than 2.0.

Embodiments are directed towards polyolefin compositions including a high molecular weight polyolefin and a low molecular weight polyolefin.

Embodiments are directed towards polyolefin compositions including a high molecular weight polyolefin and a low molecular weight polyolefin.

Polypropylenes and impact copolymers with low organic volatiles. The impact copolymers comprising a polypropylene and within a range from 5 wt% to 40 wt% of an ethylene-propylene copolymer or rubber, by weight of the impact copolymer; wherein the polypropylene has a melt flow rate within a range from 100 g/10 min to 400 g/10 min, and the impact copolymer has a melt flow rate within a range from 15 g/10 min to 150 g/10 min; and wherein there are less than 1000 .Math.g of oligomer per gram of impact copolymer. The polymers may be made by combining olefins with the reaction product of a solid magnesium compound and a halogen-containing titanium compound with at least one phthalic acid ester compound and at least one diether compound as internal electron donors.

Polypropylenes and impact copolymers with low organic volatiles. The impact copolymers comprising a polypropylene and within a range from 5 wt% to 40 wt% of an ethylene-propylene copolymer or rubber, by weight of the impact copolymer; wherein the polypropylene has a melt flow rate within a range from 100 g/10 min to 400 g/10 min, and the impact copolymer has a melt flow rate within a range from 15 g/10 min to 150 g/10 min; and wherein there are less than 1000 .Math.g of oligomer per gram of impact copolymer. The polymers may be made by combining olefins with the reaction product of a solid magnesium compound and a halogen-containing titanium compound with at least one phthalic acid ester compound and at least one diether compound as internal electron donors.

A catalyst for the polymerization of olefins made from or containing (a) a solid catalyst component containing Mg, Ti and optionally an internal electron donor compound (ID), (b) an aluminum alky compound, and (c) an external electron donor (ED) selected from non-aromatic diazo compounds.

A catalyst for the polymerization of olefins made from or containing (a) a solid catalyst component containing Mg, Ti and optionally an internal electron donor compound (ID), (b) an aluminum alky compound, and (c) an external electron donor (ED) selected from non-aromatic diazo compounds.

The present invention relates to filtration media made from melt-blown fibers having improved barrier properties. The melt-blown fibers in the filtration media of the invention are made of a visbroken metallocene-catalyzed propylene homopolymer composition with specified melting temperature Tm and molecular weight distribution (MWD).