Abstract:
The present technology relates to a process for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of free-radical polymerization initiators, wherein the polymerization is carried out in a continuously operated tubular reactor at temperatures from 100° C. to 350° C. and pressures from 180 MPa to 340 MPa, with a specific reactor surface area Asp of 2 m2/(t/h) to 5.5 m2/(t/h), and the tubular reactor has a specific ratio RDsp of 0.0050 MPa−1 to 0.0069 MPa−1 and an inner surface which has a surface roughness Ra of 2 μm or less.
Abstract:
A two steps polymerization process for obtaining a polyolefin composition comprising: a) from 25 wt % to 70 wt % of a propylene homopolymer or a propylene-ethylene copolymer containing from 0.1 wt % to 10 wt % of ethylene derived units; b) from 27 wt % to 70 wt % of a copolymer of ethylene and at least one C3-C20 alpha olefins, wherein the ethylene derived units content ranges from 15 wt % to 70 wt %; c) from 3 wt % to 20 wt % of polyethylene homopolymer or an ethylene and at least one C3-C20 alpha olefins copolymer; the sum a)+b)+c) being 100, wherein said process comprises: step a) contacting under polymerization conditions propylene, optionally ethylene and the catalyst system in order to obtain component a), step b) contacting under polymerization conditions ethylene and at least one C3-C20 alpha-olefins and the catalyst system in order to obtain components b) and c); wherein the catalyst system comprises a metallocene compound and an iron complex.
Abstract:
The present disclosure relates to a polyethylene composition with improved swell ratio and mechanical properties for use in preparing blow-moulded articles and having the following features: 1) a density from 0.945 to less than 0.952 g/cm3; 2) an MIF/MIP ratio from 15 to 30; 3) a Shear-Induced Crystallization Index (SIC) from 2.5 to 5.5.
Abstract:
The present technology relates to a process for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of free-radical polymerization initiators, wherein the polymerization is carried out in a continuously operated tubular reactor at temperatures from 100° C. to 350° C. and pressures from 180 MPa to 340 MPa, with a specific reactor surface area Asp of 2 m2/(t/h) to 5.5 m2/(t/h), and the tubular reactor has a specific ratio RDsp of 0.0050 MPa−1 to 0.0069 MPa−1 and an inner surface which has a surface roughness Ra of 2 μm or less.
Abstract:
The present disclosure relates to a polyethylene composition comprising copolymers of ethylene with 1-alkenes, or mixtures of ethylene homopolymers and said copolymers of ethylene with 1-alkenes, wherein the polyethylene composition has a molar mass distribution width (MWD) Mw/Mn of from 7 to 15, a density of from 0.942 to 0.954 g/cm3, a weight average molar mass Mw of from 20,000 g/mol to 500,000 g/mol, a MIE of from 1.0 to 3.0 g/10 min, a MIF of from 100 to 200 g/10 min, and a ratio MIF/MIE of from 40 to 50.
Abstract:
The invention relates to a polyethylene molding composition having a multimodal molar mass distribution particularly suitable for blow molding films having a thickness in the range from 8 to 200 μm. The molding composition has a density at a temperature of 23° C. in the range from 0.953 to 0.960 g/cm3 and an MFR190/5 of the final product after extrusion in the range from 0.10 to 0.50 dg/min. The composition comprises from 30 to 60% by weight of a first ethylene polymer fraction made of a homopolymer A having a first molecular weight, from 22 to 40% by weight of a second ethylene polymer fraction made of a further homopolymer or first copolymer B of ethylene and at least one first comonomer from the group of olefins having from 4 to 8 carbon atoms, the first copolymer B having a second molecular weight higher than the first molecular weight, and from 10 to 30% by weight of a third ethylene polymer fraction made of a second copolymer C having a third molecular weight higher than the second molecular weight. The molding composition of the invention allows to produce thin films having improved processability without impairing the mechanical properties.
Abstract:
A polyethylene composition having density from 0.943 to 1.1 g/cm3, comprising: A) carbon black, or a UV stabilizer, or a mixture of carbon black and a UV stabilizer; B) a polyethylene comprising copolymers of ethylene with 1-alkenes, or mixtures of ethylene homopolymers and said copolymers of ethylene with 1-alkenes, which polyethylene has molar mass distribution width (MWD) Mw/Mn of from 7 to 15, density of from 0.942 to 0.954 g/cm3, a weight average molar mass Mw of from 20,000 g/mol to 500,000 g/mol, a MIE of from 1.0 to 3.0 g/10 min, a MIF of from 100 to 200 g/10 min, and a ratio MIF/MIE of from 40 to 50.
Abstract:
A process for polymerizing olefins at temperatures of from 30° C. to 140° C. and pressures of from 1.0 MPa to 10 MPa in the presence of a polymerization catalyst in a multistage polymerization of olefins in at least two serially connected gas-phase polymerization reactors, and apparatus for the multistage polymerization of olefins, comprising at least two serially connected gas-phase polymerization reactors and a device for transferring polyolefin particles from an up-stream gas-phase polymerization reactor to a downstream gas-phase polymerization reactor, the transferring device comprising—a gas/solid separation chamber placed downstream of the upstream gas-phase polymerization which gas/solid separation chamber is equipped at a lower part with an net for introducing a fluid, and—connected to the gas/solid separation chamber at least two lock hoppers, placed in a parallel arrangement, each connected to the downstream gas-phase polymerization reactor.
Abstract:
The present technology relates to a polyethylene composition suitable for producing small articles such as flexible and collapsible tubes by blow molding comprising: 1) a density from 0.948 to 0.955 g/cm3; 2) a MIF/MIP ratio from 12 to 25; 3) a MIF from 25 to 40 g/10 min; 4) a Mz from 1000000 to 2000000 g/mol; and 5) a long-chain branching index, LCBI, equal to or greater than 0.55.
Abstract:
A multilayer fiber ABA comprising: A) at least two top layers (layer A) comprising propylene copolymer with ethylene having an ethylene derived units content ranging from 3.5 wt % to 6.5 wt %; a melt flow rate according to ISO 1133 (230° C., 2.16 Kg) comprised between from 0.5 g/10 min to 5 g/10 min; a fraction of polymer soluble in xylene at 25° C. ranging from 10 wt % to 17 wt % based on the total weight of said copolymer: B) at least one core layer (layer B) comprising a high density polyethylene having a density ranging from 0.942 g/cm3 to 0.958 g/cm3; and having a melt flow rate (MFR measured at 190° C. 5.0 kg) ranging from 0.3 g/10 min to 5 g/10 min.