Abstract:
A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from −20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.
Abstract:
A composition comprising: a) 50% to 90% of a propylene (co)polymer having: (i) a polydispersity index >3, (ii) melt flow rate >1 dg/min, and (iii) fraction soluble in xylene at 25° C. >1%, b) 5% to 25% of an ethylene/α-olefin copolymer having: (i) ethylene content over 50% but under 92% by mol, (ii) intrinsic viscosityover 1.2 but under 6 dL/g, (iii) density ranging from 0.850 to 0.890 g/cm3, and (iv) enthalpy of fusion under 62 J/g; c) 5% to 25% of a propylene/ethylene copolymer having: (i) propylene content over 50% but under 92% by mol, (ii) intrinsic viscosity over 2 but under 6 dL/g, (iii) density ranging from 0.850 to 0.890 g/cm3, (iv) product of reactivity ratios r1×r2 u nder 2, and (v) enthalpy of fusion under 45 J/g; wherein the weight ratio between component b and the sum of components b) and c) is 0.5 to 0.9.
Abstract:
A polypropylene composition comprising:A) from 30% to 90% by weight of a propylene polymer composition comprising: a1) from 20% to 90% of a propylene homopolymer, or a copolymer of propylene containing 3% or less of derived units of ethylene or C4-C10 α-olefin(s) or of combinations thereof, said homopolymer or copolymer having a content of isotactic pentads (mmmm), measured by 13C NMR on the fraction insoluble in xylene at 25° C., higher than 96; a2) from 10% to 80%, of a copolymer of ethylene containing from 40% to 70% of derived units of propylene or C4-C10 α-olefin(s) or of combinations thereof; B) from 10% to 70% by weight of a multimodal ethylene copolymer wherein the comonomer is selected from the derived units of alpha olefins of formula CH2═CHT wherein T is a C3-C10 alkyl group; having the following properties: i) density (with ISO 1183) comprised in the range from 0.850 to 0.935 g/cm3; ii) total comonomer content ranging from 6% to 30% by weight; iii) content of 1-butene derived units ranging from 0 to 2% by weight; iv) Mw/Mn comprised from 4 to 20; v) intrinsic viscosity (decalin at 135° C. as determined according to EN IS0 1628-312003) comprised between 1.0 and 4.0 dL/g, and C) from 0 to 50% by weight; preferably from 0 to 20% of a filler.
Abstract:
Polymer composition showing an improved balance of flexural modulus, IZOD impact strength and elongation at break comprising (percent by weight): A) a polymer blend comprising: A1) 50-70% of a crystalline propylene homopolymer or copolymer; and A2) 30-50% of one or more copolymer(s) of ethylene with one or more C4-C10 α-olefin(s) containing from 15 to 35% of said C4-C10 α-olefin(s); said polymer blend (A) having values of MFR equal to or higher than 10 g/10 min., a total content C4-C10 α-olefin(s) equal to or higher than 8% and an intrinsic viscosity value of the fraction soluble in xylene at room temperature of from 1.3 to 2 dl/g, the amounts of (A1) and (A2) being referred to the total weight of the polymer blend; and optionally B) 1-15% of an elastomeric polymer different from A2), having a hardness (Shore A, ASTM D-2240) value equal to or lower than 90 points; and/or C) 0.5-20% of a mineral filler; the amounts of optional components (B) and (C) being referred to the total weight of the composition.
Abstract:
A multilayer film in which at least one layer (A) comprises a copolymer (A1) of propylene with hexene-1 containing from 4 to 10% by weight of hexene-1 and having Melt Flow Rate from 1 to 10 g/10 min.; and at least one layer (B) comprises a copolymer (B1) of ethylene containing up to 20 mol % of CH2=CHR α-olefins and having a density from 0.88 to 0.945 g/cm3
Abstract:
A multistage process for the continuous production of an emulsion comprising subjecting at least two immiscible liquids to a sequence of at least two mixing stages carried out in at least two successive stator-rotor devices, wherein a peripheral outlet from a first stator-rotor device is connected to an axial inlet in the successive stator-rotor device by means of a duct in which the Reynold number ReT inside said duct is higher than 5000, and the peripheral velocity of each rotor of said stator-rotor devices ranges from 5 to 60 m/s.
Abstract:
The present invention provides polyolefin composition comprising a 50-80 wt % of propylene homopolymer or copolymer and a first and a second ethylene/alpha-olefin copolymer, said composition having good stress whitening resistance and gloss, in combination with a good balance of mechanical properties.
Abstract:
A process for the gas-phase polymerization of α-olefins carried out in two interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, the process being characterized in that: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer by introducing into the upper part of said downcomer a liquid stream LB having a composition different from the gaseous mixture present in the riser; (b) the ratio R between the flow rate Fp of polymer circulated between said downcomer and said riser and the flow rate LB of said liquid being adjusted in a range from 10 to 50.
Abstract:
A method for controlling a solution process for the polymerisation of olefins is disclosed. The method is based on an algorithm that calculates predicted operating parameters of the process, including calculation of the extent of reaction (ξ), as a function of the solution density (π), and then calculation of the whole composition of the solution. The algorithm resolves a system of equations comprising the equation of state in the PC-SAFT form, the Lewis-Mayo equation for monomer incorporation into a copolymer, and the stoichiometry equation. Predicted parameters are compared to target parameters to detect possible deviations and implement corresponding compensation in the feed.
Abstract:
A polyolefin composition having unusually low values of flexural modulus and shore hardness and comprising, in percent by weight: A) 15-40% of a copolymer of propylene with hexene-1 containing from 2.5 to 10% of hexene-1 and having Melt Flow Rate (MFR, measured according to ISO 1133, 230° C./2.16 Kg) from 0.5 to 100 g/10 min.; and B) 60-85% of an ethylene copolymer containing ethylene in a quantity equal to or lower than 40%, and having solubility in xylene at room temperature greater than 70%.