Propylene random copolymer composition containing (A) 60-80 wt % of a copolymer of propylene and from 0.1 to 2 wt % of units derived from ethylene; and (B) 20-40 wt % of a copolymer of propylene and from 7 to 15 wt % of units derived from ethylene. The composition has a total ethylene content of from 3 to 4.5 wt % and a melt flow rate value according to ISO 1133 (230° C., 2.16 kg) of from 10 to 120 g/100 min. Cast films, sheets, or injection molded or injection stretch blow molded articles made from the above composition are also disclosed.
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.
C08F 4/6592 - Component covered by group containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring
C08F 2/44 - Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
A propylene random copolymer composition is disclosed, comprising (A) 60-80wt% of a copolymer of propylene and from 0.1 to 2wt% of units derived from ethylene; and (B) 20-40wt% of a copolymer of propylene and from 7 to 15wt% of units derived from ethylene, said composition having a total ethylene content of from 3 to 4.5wt% and a melt flow rate value according to ISO 1133 (230°C, 2.16 kg) of from 10 to 120 g/10O min. Cast films, sheets, or injection moulded or injection stretch blow moulded articles made from the above composition are also disclosed.
Process for polymerising, in a loop reactor, at least one olefin monomer in a liquid diluent to produce a slurry comprising solid particulate olefin polymer and said diluent, wherein the ratio between the actual volumetric solids concentration of the slurry and the maximum possible geometric volume solids concentration of the slurry as measured by the bulk density of an unpacked settled bed of particles, SVCR, is V*0.065 or greater, and the ratio of the cumulative settling distance of an average size particle at any point in the reactor in any direction perpendicular to the direction of the flow, to the internal diameter of the loop reactor, is maintained below [0.084*(V−6.62)+(0.69−SVCR)* 1.666], where V is the circulation velocity of the slurry in m/s and “cumulative settling distance” is defined as the cumulative distance, expressed as a fraction of the diameter, travelled by a particle in any direction perpendicular to the direction of the flow since the previous upstream pump.
An insulated cable is disclosed which comprises an electrical core conductor (1) having arranged coaxially around it at least three extruded layers of polymer-based material, which layers comprise an insulating layer (3) comprising a copolymer of polyethylene and an acrylate, an outer layer (5) of a semi-conductive material, and an intermediate layer (4) between the insulating and outer layers which comprises polyethylene and is substantially free of any acrylate or conducting material, such that the outer layer (5) is strippable from the intermediate layer (4).
H01B 3/44 - Insulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances plasticsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances resinsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances waxes vinyl resinsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances plasticsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances resinsInsulators or insulating bodies characterised by the insulating materialsSelection of materials for their insulating or dielectric properties mainly consisting of organic substances waxes acrylic resins
Process for making a film or pipe by compounding an uncompounded polyolefin powder having a particle size distribution such that D95 is less than 355 μm and (D90−D10)/D50 is less than 1.2, where D95, D90, D50 and D10 are defined such that 95 wt %, 90 wt %, 50 wt % or 10 wtl % of the polymer particles have a diameter of less than D95, D90, D50 and D10 respectively, to form pellets; and then forming the pellets into a film or pipe.
Process for transferring a slurry stream containing polymer through a transfer line from a polymerisation reactor to a downstream vessel by, prior to entry into the downstream vessel, separating the slurry stream into two flows, the first flow being recycled upstream of the flow separation and the second flow being passed into the downstream vessel. The flow separation is located more than halfway along the transfer line between the reactor and the downstream vessel.
B01J 10/00 - Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particlesApparatus specially adapted therefor
B01J 19/18 - Stationary reactors having moving elements inside
Copolymers of ethylene and α-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 μm produced from the copolymer satisfying the equation DDI ≥ 19000 x {1 - Exp [-750(D - 0.908)2] } x {Exp [(0.919 - D)/0.0045] } The copolymers may suitably be prepared by use of metallocene catalysts 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.
Process for heating a polymer-containing stream being transferred from a polymerization reactor to a separation zone or device, by passing the stream through a heater having at least one transfer line for the stream and a heater for heating the transfer line. The average particle size of the solid polymer is less than 3mm, the mass flowrate of the polymer-containing stream exiting the heater is no more than 15% greater than the mass flowrate exiting the reactor, the average velocity of the polymer-containing stream either at a point 80% along the length of the heated part of the transfer line measured from the transfer line inlet, or at the transfer line outlet, is at least 6 m/s, and the pressure drop across the transfer line per unit length is between 0.0125 bar/m and 0.1 bar/m.
Process for polymerising, in a loop reactor, at least one olefin monomer in a liquid diluent to produce a slurry comprising solid particulate olefin polymer and said diluent, wherein the ratio between the actual volumetric solids concentration of the slurry and the maximum possible geometric volume solids concentration of the slurry as measured by the bulk density of an unpacked settled bed of particles, SVCR, is V*0.065 or greater, and the ratio of the cumulative settling distance of an average size particle at any point in the reactor in any direction perpendicular to the direction of the flow, to the internal diameter of the loop reactor, is maintained below [0.084*(V - 6.62) + (0.69 - SVCR)* 1.666], where V is the circulation velocity of the slurry in m/s and "cumulative settling distance" is defined as the cumulative distance, expressed as a fraction of the diameter,travelled by a particle in any direction perpendicular to the direction of the flow since the previous upstream pump.
Continuous process for manufacturing a polyolefin resin in at least two reactors in which in a first polymerization reactor, an olefin is polymerized continuously in the presence of a catalyst and a diluent to produce a first suspension comprising the diluent and polyolefin particles. At least a portion of the first suspension is transferred from the first polymerisation reactor to a second polymerisation reactor where further polymerisation takes place. A further suspension containing diluent and polymer particles is withdrawn from the second reactor and transferred to two separators, in each of which separators a diluent-rich flow and a concentrated suspension of polyolefin particles are formed and separated. The diluent-rich flow from one separator is recycled to a reactor preceding the second reactor, and the diluent-rich flow from the other separator is recycled to the second reactor. The invention enables higher separator efficiencies to be achieved.
2) 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 η*(0.1)/η(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.
F16L 9/12 - Rigid pipes of plastics with or without reinforcement
C08F 210/16 - Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
C08F 4/76 - MetalsMetal hydridesMetallo-organic compoundsUse thereof as catalyst precursors selected from metals not provided for in group selected from refractory metals selected from titanium, zirconium, hafnium, vanadium, niobium, or tantalum
F16L 9/127 - Rigid pipes of plastics with or without reinforcement the walls consisting of a single layer
C08F 4/659 - Component covered by group containing a transition metal-carbon bond
C08F 4/6592 - Component covered by group containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring
Process for heating a polymer-containing stream being transferred from a polymerization reactor to a separation zone or device, by passing the stream through at least two heaters operating in parallel, each heater having at least one transfer line for the stream and a heater for heating the transfer line. The average particle of the polymer is below 3 mm, the temperature of the polymer-containing stream at the outlet of all heaters is maintained above the dew point of the stream, and no heater has a volumetric flowrate of polymer-containing stream more than three times that of any other heater.
Fibers, tapes, monofilaments including copolymers of ethylene and α-olefins which exhibit improved tensile properties expressed as a balance between tenacity and elongation at break. The copolymers may be prepared by use of metallocene catalyst systems in particular by use of monocyclopenadienyl catalyst systems. The fibers, tapes, monofilaments of the invention are particularly suitable for end-use applications including artificial grass, woven and nonwoven fabrics, cordages, ropes, netting and flexible intermediate bulk containers.
Process for producing a multimodal polyethylene in at least two loop reactors connected in series. In the process 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor, one polymer being made in the presence of the other in either order. The ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr)/[ethylene concentration in the reactor (mol %)×residence time in the reactor (hours)×feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr), and the volumes of the two reactors differ by less than 10%.
C08F 4/44 - MetalsMetal hydridesMetallo-organic compoundsUse thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths, or actinides
C08F 4/72 - MetalsMetal hydridesMetallo-organic compoundsUse thereof as catalyst precursors selected from metals not provided for in group
B01J 19/00 - Chemical, physical or physico-chemical processes in generalTheir relevant apparatus
B01J 19/18 - Stationary reactors having moving elements inside
F01N 3/20 - Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operationControl specially adapted for catalytic conversion
Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor. The ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr)/[ethylene concentration in the reactor (mol %)×residence time in the reactor (hours)×feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr). The volume of the second reactor is at least 10% greater than the volume of the first reactor, and the ratio of length to diameter of the first reactor, L/D(1), is greater than that of the second reactor, L/D(2).
C08F 4/44 - MetalsMetal hydridesMetallo-organic compoundsUse thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths, or actinides
C08F 4/72 - MetalsMetal hydridesMetallo-organic compoundsUse thereof as catalyst precursors selected from metals not provided for in group
B01J 19/00 - Chemical, physical or physico-chemical processes in generalTheir relevant apparatus
B01J 19/18 - Stationary reactors having moving elements inside
F01N 3/20 - Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operationControl specially adapted for catalytic conversion
Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor in the presence of the HMW polymer, wherein the solids concentration in the second LMW reactor, defined as the mass of polymer divided by the total mass of slurry, is at least 35 wt %, most preferably between 45 wt % and 60 wt %, and/or the ratio of solids concentration in the first reactor to that in the second reactor is maintained at less than 1.0, preferably between 0.6 and 0.8, and further wherein the volume of the second reactor is at least 10%, preferably at least 30% and more preferably at least 50% greater than the volume of the first reactor.
C08F 4/44 - MetalsMetal hydridesMetallo-organic compoundsUse thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths, or actinides
C08F 4/72 - MetalsMetal hydridesMetallo-organic compoundsUse thereof as catalyst precursors selected from metals not provided for in group
B01J 19/00 - Chemical, physical or physico-chemical processes in generalTheir relevant apparatus
B01J 19/18 - Stationary reactors having moving elements inside
F01N 3/20 - Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operationControl specially adapted for catalytic conversion
B01J 10/00 - Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particlesApparatus specially adapted therefor
B01J 19/18 - Stationary reactors having moving elements inside
Polymerisation process in which polyethylene is produced in slurry in a polymerisation reactor in the presence of a Ziegler Natta catalyst and an activator, and a stream or slurry containing the polymer is withdrawn from the reactor and transferred to a flash tank operating at a pressure and temperature such that at least 50 mol % of the liquid or non-polymer component of the stream entering the flash tank or slurry is withdrawn from the flash tank as a vapour and at least 98 mol % of the vapour withdrawn from the flash tank is capable of being condensed at a temperature of between 15 and 50° C., without compression. A by-product suppressor, which reduces the amount of by-product formed per unit of polyethylene produced by at least 10%, compared with an identical polymerisation process where the by-product suppressor is not present, is used in the reactor. The molar ratio of the by-product suppressor added to the reactor to titanium added to the reactor is between 0.2 and 1.
3 between the average density of the polymer particles exiting the reactor with particle size above D90 and the average density of the material with particle size below D10) below 0.005, preferably below 0.003, more preferably below 0.0026, most preferably below 0.0023.
A process comprising polymerising in a loop reactor of a continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the average internal diameter of at least 50% of the total length of the reactor is at least 650 millimeters, the solids concentration in the reactor is at least 15 volume % and having a particle size distribution such that (D90−D10)/D50 is less than 2.
Process comprising polymerizing in a loop reactor of a continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerization catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent, wherein the average internal diameter of at least 50% of the total length of the continuous tubular loop reactor is at least 700 mm wherein the HMW polymer is produced in a reactor upstream of the LMW polymer reactor and the ratio of the average internal diameter of the HMW reactor to the average internal diameter of the LMW reactor is between 0.8 and 1.4.
Process for heating a polymer-containing stream being transferred from a polymerization reactor to a degassing vessel operating at a pressure between 6 bara and 12 bara. The process includes passing the stream through a heater having a transfer line for the stream and a device for heating the transfer line. The pressure drop in the heater is between 5% and 50% of the total pressure drop between the polymerization reactor and the entry to the degassing vessel. The pressure drop across the length of the heater is less than 0.5 barh per tonne of polymer, and the average Reynolds number across the cross-section of the stream at any point along the length of the transfer line of the heater is greater than 500,000, such that at least 90 mol% of the hydrocarbon fluids withdrawn from the polymerization reactor operation are vaporized before entry into the degassing vessel.
Novel copolymers are described comprising ethylene and alpha-olefins having (a) a density (D) in the range 930 - 960 kg/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 η*(0.1)/η*(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 metallocene catalyst systems. Pipes having a time to failure of ≥ 500 hrs measured according to ISO 1167 at 110oC and 2.6 MPa prepared in a single reactor are also disclosed.
2 per tonne/h of production of polymer. The pressure drop across the length of the heater is less than 0.5 bar per tonne/h of polymer, such that at least 90 mol % of the hydrocarbon fluids withdrawn from the polymerization reactor operation are vaporized before entry into the degassing vessel.
Uncompounded polyolefin powder which is multimodal and has a particle size distribution such that D95 is less than 355 μm, D5 is at least 60 μm, and (D90−D10)/D50 is less than 1.2, where D95, D90, D50 and D10 are defined such that 95 wt %, 90 wt %, 50 wt % and 10 wt % of the polymer particles have a diameter of less than D95, D90, D50 and D10 respectively.
A continuous process for manufacturing a polyolefin resin in at least two reactors in series is described, in which: in a first polymerisation reactor, an olefin is polymerised continuously in the presence of a catalyst and a diluent to produce a first suspension comprising the diluent and polyolefin particles; at least a portion of said first suspension is transferred from the first polymerisation reactor to a second polymerisation reactor where further polymerisation takes place; a further suspension comprising diluent and polymer particles is withdrawn from the second reactor and transferred to two separators, in each of which separators a diluent- rich flow and a concentrated suspension of polyolefin particles are formed and separated, wherein the diluent-rich flow from one separator is recycled to a reactor preceding the second reactor, and the diluent-rich flow from the other separator is recycled to the second reactor. The invention enables higher separator efficiencies to be achieved.
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 27mol% and 44mol% 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.
C08L 23/02 - Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bondCompositions of derivatives of such polymers not modified by chemical after-treatment
A process for heating a polymer-containing stream being transferred from a polymerization reactor to a separation zone or device, comprising passing the stream through at least two heaters operating in parallel, each heater comprising at least one transfer line for the stream and means for heating the transfer line, wherein the temperature of the polymer-containing stream at the outlet of all heaters is maintained above the dew point of the stream, and no heater has a volumetric fiowrate of polymer-containing stream more than three times that of any other heater.
A process for heating a polymer-containing stream being transferred from a polymerization reactor to a separation zone or device is described, comprising passing the stream through a heater comprising at least one transfer line for the stream and means for heating the transfer line, wherein the average particle size of the solid polymer is less than 3mm, the mass flowrate of the polymer-containing stream exiting the heater is no more than 15% greater than the mass flowrate exiting the reactor, and the average velocity of the polymer-containing stream at 80% along the length of the heated part of the transfer line measured from the transfer line inlet is at least 6 m/s, preferably at least 8m/s and more preferably at least 10m/s and the pressure drop across the transfer line is between 0.01 bar/m and 0.2 bar/m.
A process comprising polymerizing an olefin monomer optionally together with an olefin comonomer in the presence of a polymerization catalyst in a diluent in a loop reactor which comprises at least 2 horizontal sections and at least 2 vertical sections to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the Froude number in at least 20% of the length of the vertical sections of the reactor loop is less than 85% of the Froude number in at least 20% of the length of the horizontal sections of the loop is disclosed.
Apparatus for activating a catalyst is described, comprising means for passing high-temperature gases across a catalyst, a primary filter for filtering said gases, means for cooling the filtered gases, and a secondary filter for filtering the cooled gases which collects at least 99.97 % of all residual particles smaller than 0.3 μm, wherein the secondary filter is disposable and/or has a design pressure less than 0.5 bar.
A tubular reactor for use in polymerisation reactions is described, having a design pressure PR of 40-65 barg, at least a portion of which is oriented vertically and at least part of which vertical portion is surrounded by a concentric jacket for the passage of cooling fluid, wherein the design pressure in barg of the jacket PJ is less than 0.0018.PR225. Another aspect of the invention concerns a tubular reactor for use in polymerisation reactions having a design pressure PR of 40-65 barg, at least a portion of which is oriented vertically and at least part of which vertical portion is surrounded by a concentric jacket for the passage of cooling fluid, wherein the actual thickness of the reactor wall is either no more than 2mm greater and/or no more than 10% greater than the minimum wall thickness required to withstand the design pressure PR as calculated according to the ASME Boiler and Pressure Vessel code.
A cooling circuit for at least two reactors which form at least pail of a polymerisation reactor system is described, which circuit comprises: one or more heat exchangers which provide at least 95% of the cooling requirement for the cooling circuit; a cold flow of cooling fluid exiting the one or more heat exchangers, part of which cold flow passes into a first inlet flow directed to the cooling system of a first reactor, and part of which passes into a second inlet flow directed to the cooling system of a second reactor; a return flow comprising the combined exit flows of the cooling fluids used to remove the heat from each of the reactors; wherein a portion of the return flow is diverted to bypass at least one of the heat exchangers, and is wholly or partly incorporated into at least one of the first and second inlet flows. The application also covers a process using the above circuit.
The present invention relates to fibres, tapes, monofilaments and the like comprising copolymers of ethylene and α-olefins which exhibit improved tensile properties expressed as a balance between tenacity and elongation at break. The copolymers may preferable be prepared by use of metallocene catalyst systems in particlualr by use of monocyclopenadienyl catalyst systems. The fibres, tapes, monofilaments of the invention are particularly suitable for end-use applications including artificial grass, woven and nonwoven fabrics, cordages, ropes, netting and flexible intermediate bulk containers.
D01D 5/42 - Formation of filaments, threads, or the like by cutting films into narrow ribbons or filaments or by fibrillation of films
D01F 6/30 - Monocomponent man-made filaments or the like of synthetic polymersManufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds comprising olefins as the major constituent
C08F 210/16 - Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80wt% of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80wt% of a low molecular weight (LMW) polymer is made in suspension in a second reactor, wherein the ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr) / [ethylene concentration in the reactor (mol%) x residence time in the reactor (hours) x feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr), and wherein the volume of the second reactor is at least 10%, preferably at least 30% and more preferably at least 50% greater than the volume of the first reactor, and the ratio of length to diameter of the first reactor, L/D(l), is greater than that of the second reactor, L/D(2), and preferably at least 20% greater.
A polymerisation process is disclosed in which polyethylene is produced in slurry in a polymerisation reactor in the presence of a Ziegler Natta catalyst and an activator, and slurry containing the polymer is withdrawn from the reactor and transferred to a flash tank operating at a pressure and temperature such that at least 50mol% of the liquid component of the slurry is withdrawn from the flash tank as a vapour and at least 98mol%, more preferably at least 98.5mol%, and most preferably at least 99.5mol%, of the vapour withdrawn from the flash tank is capable of being condensed at a temperature of between 15 and 40C without compression, wherein a by-product suppressor, which reduces the amount of by-product formed per unit of polyethylene produced by at least 10% compared with an identical polymerisation process where the by-product suppressor is not present, is used in the reactor.
Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80wt% of a first polymer is made in suspension in a first reactor and 80-20wt% of a second polymer is made in suspension in a second reactor in the presence of the first polymer, and a stream or slurry containing the resulting polymer is withdrawn from the second reactor and transferred to a flash tank operating at a pressure and temperature such that at least 50mol% of the liquid component of the slurry, or the non- polymer component of the stream entering the flash tank, is withdrawn from the flash tank as a vapour, wherein the concentration in the stream or slurry entering the flash tank of components having a molecular weight below 50 g/mol, Qjghts (mol%), satisfies the equation Clights ឬ 7 + 0.07(40 - Tc) + 4.4(Pc - 0.8) - 7(CH2/CEt) where Tc and Pc are respectively the temperature (in °C) and pressure (MPa g) at the location where the vapour withdrawn from the flash tank is condensed, and CH2 and CEt are the molar concentrations in the flash tank of hydrogen and ethylene respectively.
C08F 297/08 - Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the coordination type polymerising mono-olefins
Process for producing a multimodal polyethylene in at least two reactors connected in series, in which 20-80wt% of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80wt% of a low molecular weight (LMW) polymer is made in suspension in a second reactor in the presence of the HMW polymer, wherein the solids concentration in the second LMW reactor, defined as the mass of polymer divided by the total mass of slurry, is at least 35wt%, most preferably between 45wt% and 60wt%, and/or the the ratio of solids concentration in the first reactor to that in the second reactor is maintained at less than 1.0, preferably between 0.6 and 0.8, and further wherein the volume of the second reactor is at least 10%, preferably at least 30% and more preferably at least 50% greater than the volume of the first reactor.
Process for producing a multimodal polyethylene in at least two loop reactors connected in series, in which 20-80wt% of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80wt% of a low molecular weight (LMW) polymer is made in suspension in a second reactor, one polymer being made in the presence of the other in either order, wherein the ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr) / [ethylene concentration in the reactor (mol%) x residence time in the reactor (hours) x feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr), and the volumes of the two reactors differ by less than 10%.
An olefin polymerisation process is disclosed in which a slurry of olefin polymer is produced within a polymerisation zone, and a polymer slurry stream is withdrawn from the polymerisation zone and passed through a transfer line to a centrifugal concentrating device, which separates it into a solids-lean stream or streams each having a solids concentration less than that of the polymer slurry stream entering the concentrating device and a solids-rich stream or streams each having a solids concentration greater than that of the polymer slurry stream entering the concentrating device, wherein at least part of the solids-rich stream or streams is recycled back into the polymer slurry stream upstream of the concentrating device and downstream of the polymerisation zone.
A process for transferring a slurry stream containing polymer through a transfer line from a first polymerisation reactor to a second polymerisation reactor is disclosed, wherein prior to entry from the transfer line into the second polymerisation reactor, the slurry stream is separated into two flows and the first flow is returned to the first reactor whilst the second flow passes into the second reactor, the length of the transfer line between the first reactor and the location of the flow separation being more than that between the second reactor and the location of the flow separation.
Process for heating a polymer-containing stream being transferred from a polymerisation reactor to a degassing vessel, comprising passing the stream through a heater comprising a transfer line for the stream and means for heating the transfer line, wherein the ratio of the stream velocity at the outlet of the heater to that at the inlet, Vo/Vi, is at least 1.1, typically between 1.2 and 4.
A process for heating a polymer-containing stream being transferred from a polymerisation reactor to a degassing vessel, comprising passing the stream through a heater comprising a transfer line for the stream and means for heating the transfer line, wherein the pressure drop in the heater is between 5% and 50%, preferably between 10 and 35%, of the total pressure drop between the polymerisation reactor and the entry to the degassing vessel.
A polyethylene composition is disclosed having an unpigmented density of at least 946 kg/m3 and a melt index MI5 of 0.05 to 2 g/10 min, and comprising from 48 to 49.5% by weight based on the total weight of the composition of an ethylene polymer fraction (A) having a density of at least 969 kg/m3, and from 50.5 to 52% by weight with based on the total weight of the composition of a copolymer fraction (B) of ethylene and 1-hexene having a melt index MI5 of 0.001 to 0.5 g/10 min and a density of no more than 930 kg/m3.
B29C 47/00 - Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor (extrusion blow-moulding B29C 49/04)
C08F 297/08 - Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the coordination type polymerising mono-olefins
49.
Drawn tapes, fibre and filaments comprising a multimodal polyethylene resin
C08L 23/00 - Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bondCompositions of derivatives of such polymers
An uncompounded polyolefin powder is disclosed, having a particle size distribution such that D95 is less than 355&mgr;m and (D90-D10)/D50 is less than 1.2, where D95, D90, D50 and D10 are defined such that 95vol%, 90vol%, 50vol% or 10vol% of the polymer particles have a diameter of less than D95, D90, D50 and D10 respectively. A process for making the powder is also disclosed.
A process which comprises polymerising an olefin monomer in at least one continuous tubular loop reactor of a multiple reactor system, optionally together with an olefin comonomer, in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and diluent, wherein the average internal diameter of at least 50% of the total length of the continuous tubular loop reactor is at least 700mm.
A pressure pipe resin is disclosed comprising from 90 to 99.9 wt %, based on the total weight of the resin, of a polyethylene, and from 0.1 to 10 wt %, based on the total weight of the blend, of an ionomer.
01 - Chemical and biological materials for industrial, scientific and agricultural use
02 - Paints, varnishes, lacquers
11 - Environmental control apparatus
Goods & Services
(1) Polyolefines et leurs copolymères à l'état brut, nommément polyéthylène et polypropylène.
(2) Matières thermoplastiques et résines synthétiques à l'état brut, nommément polyolefines et leurs copolymères à l'état brut, nommément polyéthylène et polypropylène.
01 - Chemical and biological materials for industrial, scientific and agricultural use
17 - Rubber and plastic; packing and insulating materials
Goods & Services
Thermoplastic materials and unprocessed synthetic resins. Sheets, plates and rods (semi-finished products) made of
thermoplastic materials and synthetic resins.
01 - Chemical and biological materials for industrial, scientific and agricultural use
17 - Rubber and plastic; packing and insulating materials
Goods & Services
Matières thermoplastiques et résines synthétiques à l'état
brut. Feuilles, plaques et baguettes (produits semi-finis) de
matières thermoplastiques et résines synthétiques.
01 - Chemical and biological materials for industrial, scientific and agricultural use
17 - Rubber and plastic; packing and insulating materials
Goods & Services
THERMOPLASTIC MATERIALS AND SYNTHETIC RESINS, PARTICULARLY POLYOLEFINS AND THEIR COPOLYMERS [ SEMI-FINISHED PRODUCTS-NAMELY, SHEETS, PLATES, AND RODS OF THERMOPLASTIC MATERIALS AND SYNTHETIC RESINS ]
A composition suitable for use in pressure pipes and pipe fittings is disclosed comprising polymer of ethylene and from 0.5 to 5 wt% of a C4-C8 alpha-olefin which has a natural density of 935-956 kg/m3, a melt index MI5 of 0.15 - 0.5 g/10min, a dynamic complex viscosity at 100 rad/s and 190 ~C (.eta.100) of no more than 2500 Pa.s, a relationship between .eta.100 and dynamic complex viscosity measured in Pa.s at 0.01 rad/s and 190 ~C (.eta.0.01) defined by the equation .eta.0.01 > 115000 + 30. .eta.100, and an environmental stress crack resistance as measured by a notched pipe test performed according to ISO13479:1997 on 110 mm SDR 11 pipes at 80 ~C and a pressure of 9.2 bar, of greater than 1000 hours, or: wherein the C4-C8 alpha-olefin is 1-hexene or 1-octene.
C08F 297/08 - Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the coordination type polymerising mono-olefins
A propylene random copolymer composition is disclosed, comprising (A) 60-80wt% of a copolymer of propylene and from 0.1 to 2wt% of units derived from ethylene; and (B) 20-40wt% of a copolymer of propylene and from 7 to 15wt% of units derived from ethylene, said composition having a total ethylene content of from 3 to 4.5wt% and a melt flow rate value according to ISO 1133 (230°C, 2.16 kg) of from 10 to 120 g/10O min. Cast films, sheets, or injection moulded or injection stretch blow moulded articles made from the above composition are also disclosed.
