A butene-1 polymer composition having MFR values of from 20 to less than 100 g/10 min., measured according to ISO 1133 at 190° C. with a load of 2.16 kg, made from or containing: A) a butene-1 homopolymer or a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of up to 5% by mole; and B) a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of from 6% to 20% by mole; wherein the composition having a total copolymerized comonomer content from 4% to 15% by mole, referred to the sum of A) and B), and a content of fraction soluble in xylene at 0° C. of 75% by weight or less, determined on the total weight of A) and B).

A butene-1 polymer composition having a MFR value of from 100 to 300 g/10 min., measured according to ISO 1133 at 190° C. with a load of 2.16 kg, made from or containing: A) a butene-1 homopolymer or a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of up to 5% by mole; B) a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of from 6% to 20% by mole;
wherein the composition having a total copolymerized comonomer content from 4% to 15% by mole, referred to the sum of A) and B), and a content of fraction soluble in xylene at 0° C. of 75% by weight or less, determined on the total weight of A) and B).

A butene-1 polymer composition having a MFR value of from 100 to 300 g/10 min., measured according to ISO 1133 at 190° C. with a load of 2.16 kg, made from or containing: A) a butene-1 homopolymer or a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of up to 5% by mole; B) a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of from 6% to 20% by mole;
wherein the composition having a total copolymerized comonomer content from 4% to 15% by mole, referred to the sum of A) and B), and a content of fraction soluble in xylene at 0° C. of 75% by weight or less, determined on the total weight of A) and B).

An ethylene alpha-olefin copolymer having (a) a density of from about 0.910 g/cc to about 0.940 g/cc; (b) a weight average molecular weight of from about 150,000 g/mol to about 300,000 g/mol; and (c) a melt index at a load of 2.16 kg of from about 0.01 dg/10 min. to about 0.5 dg/min.; wherein a 1 mil blown film formed from the polymer composition is characterized by (i) a Dart Impact strength greater than about 175 g/mil; (ii) an Elmendorf machine direction tear strength greater than about 20 g/mil; and (iii) an Elmendorf transverse direction tear strength greater than about 475 g/mil.

An ethylene alpha-olefin copolymer having (a) a density of from about 0.910 g/cc to about 0.940 g/cc; (b) a weight average molecular weight of from about 150,000 g/mol to about 300,000 g/mol; and (c) a melt index at a load of 2.16 kg of from about 0.01 dg/10 min. to about 0.5 dg/min.; wherein a 1 mil blown film formed from the polymer composition is characterized by (i) a Dart Impact strength greater than about 175 g/mil; (ii) an Elmendorf machine direction tear strength greater than about 20 g/mil; and (iii) an Elmendorf transverse direction tear strength greater than about 475 g/mil.

The present invention relates to a hybrid supported metallocene catalyst and a polyolefin preparation method using the same. Using the hybrid supported metallocene catalyst can not only significantly reduce the amount of wax produced when polymerizing olefin monomers, but can also enhance the stress cracking resistance of the polyolefin that is prepared.

A butene-1 polymer having: a) a Melt Flow Rate value of from 100 to 300 g/10 min., measured according to ISO 1133 at 190° C. with a load of 2.16 kg; b) an intrinsic viscosity (IV) measured in tetrahydronaphthalene (THN) at 135° C. equal to lower than 0.70 dl/g; c) a Mw/Mn value equal to or lower than 2.8 and a lower limit of 1.5; d) a Mz value of 90,000 g/mol or higher; and e) optionally, a comonomer content of up to 10% by mole.

A butene-1 polymer having: a) a Melt Flow Rate value of from 100 to 300 g/10 min., measured according to ISO 1133 at 190° C. with a load of 2.16 kg; b) an intrinsic viscosity (IV) measured in tetrahydronaphthalene (THN) at 135° C. equal to lower than 0.70 dl/g; c) a Mw/Mn value equal to or lower than 2.8 and a lower limit of 1.5; d) a Mz value of 90,000 g/mol or higher; and e) optionally, a comonomer content of up to 10% by mole.

A process for preparing an olefin polymer, including the steps of forming a particulate olefin polymer in a gas-phase polymerization reactor in the presence of a C.sub.3-C.sub.5 alkane as polymerization diluent, separating discharged polyolefin particles from concomitantly discharged gas at a pressure from 1 to 2.2 MPa, degassing the polyolefin particles at a pressure from 0.1 to 0.4 MPa with a gas made from or containing a C.sub.3-C.sub.5 alkane; and transferring the separated gas and the gas from the degassing to a work-up unit operated at a pressure from 0.001 to 0.2 MPa below the pressure of the separation, wherein the gas for degassing is continuously received from the work-up unit.

A process for preparing an olefin polymer, including the steps of forming a particulate olefin polymer in a gas-phase polymerization reactor in the presence of a C.sub.3-C.sub.5 alkane as polymerization diluent, separating discharged polyolefin particles from concomitantly discharged gas at a pressure from 1 to 2.2 MPa, degassing the polyolefin particles at a pressure from 0.1 to 0.4 MPa with a gas made from or containing a C.sub.3-C.sub.5 alkane; and transferring the separated gas and the gas from the degassing to a work-up unit operated at a pressure from 0.001 to 0.2 MPa below the pressure of the separation, wherein the gas for degassing is continuously received from the work-up unit.