Abstract: Copolymers of ethylene and ?-olefins having C7-C12 carbon atoms having: (a) a density (D) in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range of 0.01-50 g/10 min, (c) a melt elastic modulus G? (G?=500 Pa) in the range 20 to 150 Pa, and (d) a tear strength (MD) of ?220 g, a tear strength (TD) of ?470 g, and a Dart Drop Impact (DDI) of ?1800 g of a blown film having a thickness of 25 ?m produced from the copolymer; where MD is referred to the machine direction and TD is the transverse direction of the blown film are suitably prepared in the gas phase by use of a supported metallocene catalyst system. Particularly suitable are copolymers of ethylene and 1-octene and the resultant blown films show improved processability and exhibit an improved balance of film properties of dart impact and tear strength.

Abstract: Copolymers comprising ethylene and alpha-olefins having (a) a density (D) in the range 930-960/g/m3 (b) a melt index (MI2) in the range 0.1-3.5 g/10 min (c) a melt elastic modulus G? (G?=500 Pa) in the range 40 to 150 Pa, and (d) a ratio of complex dynamic shear viscosities ?*(0.1)/?(100) in the range 1.5 to 5.5. The copolymers are suitable for use as Polyethylenes of Raised Temperature Resistance (PE-RT) for use in hot water piping systems. The copolymers may be prepared by use of meltallocene catalyst systems. Pipes having a time to failure of ?500 hrs measured according to ISO 1167 at 110° C. and 2.6 MPa prepared in a single reactor are also disclosed.

Abstract: A copolymer of ethylene and an alpha-olefin, said copolymer having a (a) density>0.930 g/cm3, (b) melt index (g/10 min)>4, (c) molecular weight distribution (MWD)>3.0, and (d) FNCT>250 hours, and is described suitable for use in rotomolding applications. In particular the novel copolymers result in improved impact strength, improved permeation resistance and improved environmental stress crack resistance and may suitably be prepared by use of metallocene catalysts.

Abstract: Copolymers of ethylene and ?-olefins having (a) a density in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range 0.01-50 g/10 min, (c) a molecular weight distribution (Mw/Mn, by conventional GPC) in the range 2.0-4.5, (d) a comonomer partition factor, Cpf>1, and (e) a melt index MI2 (2.16 kg, 190° C.) normalized Dow Rheology Index (DRI), [DRI/MI2] in the range 3-20. The copolymers may be prepared using catalyst systems containing activating supports. The copolymers are suitably prepared in the gas phase preferably in a single reactor. The copolymers exhibit unique properties in particular with respect to their rheology.

Abstract: Novel polymer blends comprise (a) 90-97% by weight of a copolymer of ethylene and an alpha olefin having from 3 to 10 carbon atoms, said copolymer having (i) a density in the range of 0.910 to 0.940 g cm?3, (ii) a melt index (190° C./2.16 kg), MI2<5, and (iii) molecular weight distribution Mw-cc/Mn-cc, by classical GPC) in the range 2.0-5.0, and (b) from 3-10% by weight of a low density polyethylene polymer having (i) a density from 0.910 to 0.920 g cm?3, (ii) a melt index (190° C./2.16 kg), MI2>2, and (iii) a melt elastic modulus G? (G?=500 Pa)>140 Pa at 190° C., wherein the sum of (a) and (b) is 100%. The copolymer component (a) may be prepared by use of metallocene catalyst systems and the novel blends exhibit an improved balance of processability and mechanical properties and are particularly useful for film applications.

Abstract: Novel copolymers of ethylene and ?-olefins are provided having (a) a density in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range 0.01-50 g/10 min, (c) a molecular weight distribution (Mw/Mn, by conventional GPC) in the range 2.0-4.5, (d) a comonomer partition factor, Cpf>1, and (e) a melt index MI2 (2.16 kg, 190° C.) normalized Dow Rheology Index (DRI), [DRI/MI2] in the range 3-20. The novel copolymers may suitably be prepared by use of catalyst systems comprising activating supports. The copolymers are suitably prepared in the gas phase preferably in a single reactor. The copolymers exhibit unique properties in particular with respect to their rheology.

Abstract: A copolymer of ethylene and an alpha-olefin, said copolymer having a (a) density>0.930 g/cm3, (b) melt index (g/10 min)>4, (c) molecular weight distribution (MWD)>3.0, and (d) FNCT>250 hours, and is described suitable for use in rotomolding applications. In particular the novel copolymers result in improved impact strength, improved permeation resistance and improved environmental stress crack resistance and may suitably be prepared by use of metallocene catalysts.

Abstract: Copolymers of ethylene and ?-olefins having (a) a density (D) in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range of 0.01-50 g/10 min, (c) a melt index MI2 (2.16 kg, 190° C.) and Dow Rheology Index (DRI) satisfying the equation [DRI/MI2]>2.65, and (d) a Dart Drop Impact (DDI) in g of a blown film having a thickness of 25 ?m produced from the copolymer satisfying the equation DDI?1900×{1?Exp [?750(D?0.908)2]}×{Exp [(0.919?D)/0.0045]}. The copolymers may be prepared using metallocene catalysis and are preferably prepared in multistage processes carried out in loop reactors in the slurry phase. The copolymers exhibit long chain branching as defined by Dow Rheology Index (DRI) and exhibit unexpected improvements in mechanical properties, in particular dart drop impact, when extruded into blown films.

Abstract: Copolymers of ethylene and ?-olefins are provided having (a) a density (D) in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range of 0.01-50 g/10 min, (c) a melt index MI2 (2.16 kg, 190° C.) and Dow Rheology Index (DRI) satisfying the equation [DRI/MI2]>2.65, and (d) a Dart Drop Impact (DDI) in g of a blown film having a thickness of 25 ?m produced from the copolymer satisfying the equation DDI?1900×{1?Exp[?750(D?0.908)2]}×{Exp[(0.919?D)/0.0045]}. The copolymers may suitably be prepared by use of metallocene catalysis and are preferably prepared in multistage processes earned out in loop reactors in the slurry phase. The copolymers exhibit long chain branching as defined by Dow Rheology Index (DRI) and exhibit unexpected improvements in mechanical properties, in particular dart drop impact, when extruded into blown films.

Abstract: Copolymers of ethylene and ?-olefins having C7—C12 carbon atoms having: (a) a density (D) in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range of 0.01-50 g/10 min, (c) a melt elastic modulus G? (G?=500 Pa) in the range 20 to 150 Pa, and (d) a tear strength (MD) of ?220 g, a tear strength (TD) of ?470 g, and a Dart Drop Impact (DDI) of ?1800 g of a blown film having a thickness of 25 ?m produced from the copolymer; where MD is referred to the machine direction and TD is the transverse direction of the blown film are suitably prepared in the gas phase by use of a supported metallocene catalyst system. Particularly suitable are copolymers of ethylene and 1-octene and the resultant blown films show improved processability and exhibit an improved balance of film properties of dart impact and tear strength.

Abstract: Copolymers of ethylene and an alpha-olefin having (a) a density in the range 0.900-0.940 g/cm3, (b) a molecular weight distribution (Mw/Mn) in the range 3.5 to 4.5, (c) a melt elastic modulus G? (G?=500 Pa) in the range 40 to 150 Pa, (d) an activation energy of flow (Ea) in the range 28-45 kJ/mol, and (e) a melt index (g/10 ml) in the range 1.0-3.5. The copolymers are suitably prepared in the gas phase by use of a supported metallocene catalyst system. The copolymers show improved processability and are particular suitable for use in blown film applications.

Abstract: Novel polymer blends comprise (a) 1-99% by weight of a copolymer of ethylene and an alpha olefin having from 3 to 10 carbon atoms, said copolymer having (iv) a density in the range 0.905 to 0.940 g cm?3, (v) a melt elastic modulus G? (G?=500 Pa) in the range 10 to 150 Pa, and (vi) a melt index in the range 5 to 50, and (b) from 1-99% by weight of a low density polyethylene (LDPE) polymer having a density from 0.914 to 0.928 g cm?3 wherein the sum of (a) and (b) is 100%. The copolymers of component (a) are typically prepared by use of metallocene catalysts. The blends exhibit advantageous melt elastic modulus in the range 30 to 200 Pa. The blends are particularly suitable for extrusion coating applications.

Abstract: Novel copolymers are described comprising ethylene and alpha-olefins having (a) a density (D) in the range 930-960/g/m3 (b) a melt index (MI2) in the range 0.1-3.5 g/10 min (c) a melt elastic modulus G? (G?=500 Pa) in the range 40 to 150 Pa, and (d) a ratio of complex dynamic shear viscosities ?*(0.1)/?*(100) in the range 1.5 to 5.5. The novel copolymers are particularly suitable for use as Polyethylenes of Raised Temperature Resistance (PE-RT) for use in hot water piping systems. The novel copolymers may be prepared by use of meltallocene catalyst systems. Pipes having a time to failure of ?500 hrs measured according to ISO 1167 at 110° C. and 2.6 MPa prepared in a single reactor are also disclosed.

Abstract: Film formed from a polyethylene resin composition which obeys a dynamic rheological relationship at 190° C. between melt storage modulus G?, measured in Pa and at a dynamic frequency where the loss modulus G?=3000 Pa, and dynamic complex viscosity ?*100, measured in Pa·s at 100 rad/s, such that (a) G?(G?=3000)>?0.86?*100+z where z=3800, and at the same time (b) G?(G?=3000)>0.875?*100?y where y=650, and having an impact strength (DDT) of at least 250 g, measured on 15 ?m thick film (blown under conditions with BUR=5:1 and Neck Height=8×D) conditioned for 48 hours at 20°-25° C., according to ASTM D1709.

Abstract: Oxygen barrier compositions are described comprising 70-95 wt % of a polyolefin, and incorporated in said polyolefin ?0.1-10 wt % of an ethylene-vinyl alcohol polymer containing between 27 mol % and 44 mol % of ethylene units; 0.1-5 wt % of an active oxygen scavenger; 0.1-10 wt % of either a clay having an aspect ratio of at least 10, preferably at least 20, more preferably at least 50, or a nucleating agent, or a polyamide optionally containing such a clay or nucleating agent; and 0.1-5 wt % of a compatibiliser.

Abstract: A copolymer of ethylene and an alpha-olefin, said copolymer having a (a) density>0.930 g/cm3, (b) melt index (g/10 min)>4, (c) molecular weight distribution (MWD)>3.0, and (d) FNCT>250 hours., and is described suitable for use in rotomoulding applications. In particular the novel copolymers result in improved impact strength, improved permeation resistance and improved environmetal stress crack resistance and may suitably be prepared by use of metallocene catalysts.

Abstract: Copolymers of ethylene and alpha-olefins having (a) a density in the range 0.900-0.940 g/cm3, (b) a molecular weight distribution (Mw/Mn) in the range 3.5 to 4.5, (c) a melt elastic modulus G? (G?=500 Pa) in the range 40 to 150 Pa and (d) an activation energy of flow (Ea) in the range 28-45 kJ/mol. are suitably prepared in the gas phase by use of a supported metallocene catalyst system. The novel copolymers show improved processability and are particular suitable for use in blown film applications.

Abstract: A process for the polymerisation of olefins is described involving the use of a catalyst system comprising a supported transition metal compound and an activator based on an organoborane and an aluminoxane. Preferably the transition metal compound is a metallocene complex. The support is pretreated with an organoaluminium compound and the process is particularly suitable for the gas phase preparation of copolymers of ethylene and alpha-olefins having a molecular weight distribution in the range 2.5-7.0 and a melt strength in the range 3-12 cN.

Abstract: Novel copolymers comprise ethylene and alpha olefins having from 3 to 10 carbon atoms and which have (a) a density in the range 0.900 to 0.940 (b) Mw/Mn of 2-3.4 (c) I21/I2 from 16 to 24 (d) activation energy of flow from 28 to 45 kJ/mol (e) a ratio Ea(HMW)/Ea(LMW)>1.1, and (f) a ratio g?(HMW)/g?(LMW) from 0.85 to 0.95 The copolymers are particularly useful in film applications showing an excellent balance of processing, optical and mechanical properties. The novel polymers may suitably be prepared in the gas phase in the presence of metallocene complexes.

Abstract: A process for the polymerisation of olefins is described involving the use, of a catalyst system comprising a supported transition metal compound and an activator based on an organoborane and an aluminoxane. Preferably the transition metal compound is a metallocene complex. The support is pretreated with an organoaluminium compound and the process is particularly suitable for the gas phase preparation of copolymers of ethylene and alpha-olefins having a molecular weight distribution in the range 2.5-7.0 and a melt strength in the range 3-12 cN.