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).

Disclosed are a spherelike supermacroporous mesoporous material, a polyolefin catalyst, and a preparation method therefor and an olefin polymerization process. The spherelike supermacroporous mesoporous material has a twodimensional hexagonal ordered pore channel structures. The mesoporous material has an average pore size of 10 nm to 15 nm, a specific surface area of 300 m.sup.2/g to 400 m.sup.2/g, and an average particle size of 1 .Math.m to 3 .Math.m, based on the total mass of the mesoporous material. The mass content of water in the mesoporous material is < 1 ppm. The mass content of oxygen in the mesoporous material is < 1 ppm. When a polyolefin catalyst prepared with the mesoporous material as a carrier is used for an olefin polymerization reaction, the a polyolefin product with a narrow molecular weight distribution and a good melt index can be obtained.

Disclosed are a spherelike supermacroporous mesoporous material, a polyolefin catalyst, and a preparation method therefor and an olefin polymerization process. The spherelike supermacroporous mesoporous material has a twodimensional hexagonal ordered pore channel structures. The mesoporous material has an average pore size of 10 nm to 15 nm, a specific surface area of 300 m.sup.2/g to 400 m.sup.2/g, and an average particle size of 1 .Math.m to 3 .Math.m, based on the total mass of the mesoporous material. The mass content of water in the mesoporous material is < 1 ppm. The mass content of oxygen in the mesoporous material is < 1 ppm. When a polyolefin catalyst prepared with the mesoporous material as a carrier is used for an olefin polymerization reaction, the a polyolefin product with a narrow molecular weight distribution and a good melt index can be obtained.

This disclosure relates to ethylene interpolymer product having intermediate branching. Intermediate branching was defined as branching that was longer than the branch length due to comonomer and shorter than the entanglement molecular weight (M.sub.e). Intermediately branched ethylene interpolymer products were produced in a continuous solution polymerization process employing an intermediate branching catalyst formulation. Intermediately branched ethylene interpolymer products were characterized by a Non-Comonomer Index Distribution (NCID.sub.i), a melt index from 0.3 to 500 dg/minute, a density from 0.858 to 0.965 g/cm.sup.3, a polydispersity (M.sub.w/M.sub.n) from about 2 to about 25 and a CDBI.sub.50 from about 10% to about 98%. A method based on triple detection cross fractionation chromatography (3D-CFC) was disclosed to measure NCID.sub.i.

This disclosure relates to ethylene interpolymer product having intermediate branching. Intermediate branching was defined as branching that was longer than the branch length due to comonomer and shorter than the entanglement molecular weight (M.sub.e). Intermediately branched ethylene interpolymer products were produced in a continuous solution polymerization process employing an intermediate branching catalyst formulation. Intermediately branched ethylene interpolymer products were characterized by a Non-Comonomer Index Distribution (NCID.sub.i), a melt index from 0.3 to 500 dg/minute, a density from 0.858 to 0.965 g/cm.sup.3, a polydispersity (M.sub.w/M.sub.n) from about 2 to about 25 and a CDBI.sub.50 from about 10% to about 98%. A method based on triple detection cross fractionation chromatography (3D-CFC) was disclosed to measure NCID.sub.i.

An ethylene copolymer comprising ethylene and at least one alpha olefin having from 4 to 8 carbon atoms has a density f from 0.940 to 0.960 g/cm.sup.3, a molecular weight distribution, Mw/Mn of from 9 to 12, and a Z-average molecular weight, Mz of greater than 500,000. The ethylene copolymer is made in a multi-zone reactor system under solution phase polymerization conditions and is useful in the preparation of biaxially oriented polyethylene (BOPE) films.

An ethylene copolymer comprising ethylene and at least one alpha olefin having from 4 to 8 carbon atoms has a density f from 0.940 to 0.960 g/cm.sup.3, a molecular weight distribution, Mw/Mn of from 9 to 12, and a Z-average molecular weight, Mz of greater than 500,000. The ethylene copolymer is made in a multi-zone reactor system under solution phase polymerization conditions and is useful in the preparation of biaxially oriented polyethylene (BOPE) films.

The present disclosure relates to a Ziegler-Natta catalyst system comprising a pro-catalyst, a co-catalyst and a selectivity control agent. The pro-catalyst comprises a magnesium compound, a titanium compound and a multi-dentate internal donor, wherein the internal donor is tetraethyl 3,3,3′,3′-tetramethyl-2,2′,3,3′-tetrahydro-1,1′-spirobiindane-5,5′,6,6′-tetracarbonate. The present disclosure further relates to a process for polymerization of an olefin using the Ziegler-Natta catalyst system. The Ziegler-Natta catalyst system of the present disclosure shows very high hydrogen response and thus can be used to produce low to high molecular weight polyolefin.

The present disclosure relates to a Ziegler-Natta catalyst system comprising a pro-catalyst, a co-catalyst and a selectivity control agent. The pro-catalyst comprises a magnesium compound, a titanium compound and a multi-dentate internal donor, wherein the internal donor is tetraethyl 3,3,3′,3′-tetramethyl-2,2′,3,3′-tetrahydro-1,1′-spirobiindane-5,5′,6,6′-tetracarbonate. The present disclosure further relates to a process for polymerization of an olefin using the Ziegler-Natta catalyst system. The Ziegler-Natta catalyst system of the present disclosure shows very high hydrogen response and thus can be used to produce low to high molecular weight polyolefin.

A heterophasic polypropylene copolymer having an MFR2 of 0.05 to 20 g/10 min (ISO 1133 at 230° C. with a loading of 2.16 kg) and a melting point (Tm) of 156 to 164° C. (measured by DSC according to ISO 11357) wherein the heterophasic polypropylene copolymer comprises at least the following components: (A) 55.0 to 95.0 wt % of a crystalline fraction (CF) having a comonomer content of 0 to 3.0 wt %; and (B) 5.0 to 45.0 wt % of a soluble fraction (SF) having a comonomer content of 12 to 45 wt %; wherein the intrinsic viscosity (IV) (in decalin at 135° C.) of the soluble fraction (SF) is 2.5 to 11 dl/g, and wherein the amount of crystalline fraction (CF) and the amount of soluble fraction (SF) are determined in 1,2,4-trichlorobenzene at 40° C.