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.

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 catalyst system includes a heterogeneous procatalyst, an electron donor, and a hydrogenation procatalyst. The heterogeneous procatalyst includes a titanium species, an aluminum species, and a magnesium chloride component. The hydrogenation procatalyst has the formula Cp.sub.2TiX.sub.nTiCp.sub.2 or Cp.sub.2TiX.sub.n. In formula Cp.sub.2TiX.sub.n, each Cp is a cyclopentadienyl substituted with at least one R.sup.1, wherein R.sup.1 is (C.sub.1-C.sub.10)alkyl; and each X is independently monoanionic or neutral, wherein each X is independently (C.sub.1-C.sub.40)hydrocarbon, (C.sub.1-C.sub.40)heterohydrocarbon, (C.sub.1-C.sub.40)hydrocarbyl, (C.sub.1—C.sub.40)heterohydrocarbyl, or a halogen atom.

The catalyst system includes a heterogeneous procatalyst, an electron donor, and a hydrogenation procatalyst. The heterogeneous procatalyst includes a titanium species, an aluminum species, and a magnesium chloride component. The hydrogenation procatalyst has the formula Cp.sub.2TiX.sub.nTiCp.sub.2 or Cp.sub.2TiX.sub.n. In formula Cp.sub.2TiX.sub.n, each Cp is a cyclopentadienyl substituted with at least one R.sup.1, wherein R.sup.1 is (C.sub.1-C.sub.10)alkyl; and each X is independently monoanionic or neutral, wherein each X is independently (C.sub.1-C.sub.40)hydrocarbon, (C.sub.1-C.sub.40)heterohydrocarbon, (C.sub.1-C.sub.40)hydrocarbyl, (C.sub.1—C.sub.40)heterohydrocarbyl, or a halogen atom.

A polyethylene-based composition may include an ethylene-based copolymer produced from ethylene and one or more C3-C10 alpha olefin comonomers, wherein the ethylene-based copolymer has: a density ranging from 945 kg/m.sup.3 to 961 kg/m.sup.3 according to ASTM D792, a melt flow rate (MFR.sub.2) ranging from 0.5 g/10 min to 3.0 g/10 min according to ASTM D1238 at 190° C./2.16 kg, a molecular weight distribution (Mw/Mn) ranging from 3 to 25, and a stress exponent (SEx) ranging from 1.0 to 1.8.

A polyethylene-based composition may include an ethylene-based copolymer produced from ethylene and one or more C3-C10 alpha olefin comonomers, wherein the ethylene-based copolymer has: a density ranging from 945 kg/m.sup.3 to 961 kg/m.sup.3 according to ASTM D792, a melt flow rate (MFR.sub.2) ranging from 0.5 g/10 min to 3.0 g/10 min according to ASTM D1238 at 190° C./2.16 kg, a molecular weight distribution (Mw/Mn) ranging from 3 to 25, and a stress exponent (SEx) ranging from 1.0 to 1.8.

The present invention relates to a supported polymetal olefin polymerization catalyst, comprising a porous support, a magnesium-containing support component, a transition metal titanium component supported on the porous support, and further comprising at least one non-magnesium metal component supported on the porous support. Further provided is a preparation method and a use of the supported polymetal olefin polymerization catalyst. An efficient composite support supported polymetal Ziegler-Natta catalyst is provided in the present invention, wherein a porous support, a soluble magnesium compound, and a soluble non-magnesium metal compound are used as raw materials. The supporting of titanium is achieved while a composite support containing magnesium and non-magnesium metal components is formed in situ in the surface of the porous support. The present invention has the advantage of a simple preparation method, a low cost, a controllability of morphology, properties of the catalyst, etc. Comparing the provided catalyst with the same type of magnesium/titanium catalyst free of non-magnesium metal components, the catalytic performance such as polymerzation activity, hydrogen regulation sensitivity and copolymerization performance are significantly improved.

The present invention relates to a supported polymetal olefin polymerization catalyst, comprising a porous support, a magnesium-containing support component, a transition metal titanium component supported on the porous support, and further comprising at least one non-magnesium metal component supported on the porous support. Further provided is a preparation method and a use of the supported polymetal olefin polymerization catalyst. An efficient composite support supported polymetal Ziegler-Natta catalyst is provided in the present invention, wherein a porous support, a soluble magnesium compound, and a soluble non-magnesium metal compound are used as raw materials. The supporting of titanium is achieved while a composite support containing magnesium and non-magnesium metal components is formed in situ in the surface of the porous support. The present invention has the advantage of a simple preparation method, a low cost, a controllability of morphology, properties of the catalyst, etc. Comparing the provided catalyst with the same type of magnesium/titanium catalyst free of non-magnesium metal components, the catalytic performance such as polymerzation activity, hydrogen regulation sensitivity and copolymerization performance are significantly improved.

Novel catalyst compositions comprising three or more transition metals are effective in increasing catalyst efficiency, reducing polydispersity, and increasing uniformity in molecular weight distribution when used in olefin, and particularly, linear low density polyethylene (LLDPE), polymerizations. The resulting polymers may be used to form differentiated products including, for example, films that may exhibit improved optical and mechanical properties.