Abstract:
A method for treating polymer particles with steam in a steaming vessel downstream a polymerization process, the method comprising contacting polymer particles with a counter-current flow of steam, wherein the flow rate of steam entering said steaming vessel is continuously maintained proportional to the production rate of said polymer in said polymerization process and to the gradient between the temperature (Tout) of the polymer exiting said steaming vessel and the temperature (Tin) of the polymer entering said steaming vessel.
Abstract:
1-butene/ethylene/propylene terpolymer containing: c) from 4 to 10 wt % of ethylene derived units, and d) from 2 to 10 wt % of propylene derived units; the said terpolymer having the following properties: distribution of molecular weights (Mw/Mn) measured by GPC lower than 3; no melting point detectable at the DSC; melting enthalpy, measured after 10 days of aging at room temperature, from 12 to 20 J/g.
Abstract:
Use of propylene copolymers with up to 50 wt % of units derived from at least one linear or branched alpha-olefin having from 2 to 10 carbon atoms other than propylene for producing injection-molded coating on a metallic pipe.
Abstract:
The present invention relates to catalysts component for the polymerization of ethylene and its mixtures with olefins CH2═CHR, wherein R is an alkyl, cycloalkyl or aryl radical having 1-12 carbon atoms, comprising Ti, Mg, halogen, and electron donor belonging to 1,2-diethers as internal electron donor compound. The catalyst of the invention is suitably used in (co)polymerization processes of ethylene to prepare (co)polymers having narrow Molecular Weight Distribution (MWD) and high bulk density.
Abstract:
Solid adducts comprising MgCl2 and water and optionally an organic hydroxy compound (A) selected from hydrocarbon structures containing at least one hydroxy group, said compounds being present in molar ratio defined by the following formula MgCl2.(H20)n(A)p in which n is from 0.6 to 6, p ranges from 0 to 3, said adduct having a porosity (PF), measured by the mercury method and due to pores with radius equal to or lower than 1 μm, of at least 0.15 cm3/g with the proviso that when p is 0, (PF) is equal to or higher than 0.3 cm3/g.
Abstract:
Polyolefin compositions comprising, all percentages being by weight: A) from 70 to 95%, of a compositions comprising (by weight): AI) 15-80% of one or more copolymers of propylene; AII) 20-85% of one or more copolymers with different comonomer(s) content than in A) B) from 5 to 30% of an elastomeric or plastomeric polyolefin or polyolefin composition.
Abstract:
The present invention relates to catalysts systems for the polymerization of ethylene and its mixtures with olefins CH2═CHR, wherein R is an alkyl, cycloalkyl or aryl radical having 1-12 carbon atoms, comprising (A) a solid catalyst component comprising Ti, Mg, halogen, and optionally an electron donor compound in a donor/Ti molar ratio lower than 1, (B) an aluminum alkyl compound and (C) a silicon compound of formula RImSi(ORII)n in which RI is C1-C20 alkyl group, RII is a secondary or tertiary alkyl group or a cycloalkyl having from 3 to 20 carbon atoms, m is an integer ranging from 0 to 3, and n is (4-m). The catalyst of the invention is suitably used in (co)polymerization processes of ethylene to prepare (co)polymers having narrow Molecular Weight Distribution (MWD) and high activity.
Abstract:
A propylene composition comprising (percent by weight): A) 70%-95%, of a propylene homopolymer having a Polydispersity Index (P.I.) value of from 4.6 to 10, a fraction insoluble in xylene at 25° C., higher than 90%, and MFR L (Melt Flow Rate according to ISO 1133, condition L, i.e. 230° C. and 2.16 kg load) from 100 to 250 g/10 min; B) 5%-30%, of a copolymer of propylene containing from 36% to 44% of ethylene derived units; the composition having an intrinsic viscosity of the fraction soluble in xylene at 25° C. comprised between 3 and 5 dl/g.
Abstract:
A single- or multilayer threaded pipe, wherein at least one layer is produced from a polyolefin composition comprising (percentages express on the basis of the sum of components (A) and (B)): (A) 65-90 wt % of a heterophasic polypropylene composition comprising (percentages expressed on the basis of the polypropylene composition): (1) 65-95 wt % of a propylene polymer selected from propylene homopolymer and co- and terpolymers of propylene with a comonomer selected from ethylene, a C4-C10 alpha-olefin and a mixture thereof, said polymer containing 0.1-10 wt % of comonomer units, being insoluble in xylene at 25° C. in an amount over 85 wt %, having a polydispersity index ranging from 4 to 13 and an intrinsic viscosity ([η]1) value of over 2.2 dl/g; and (2) 5-35 wt % of an olefin polymer of ethylene with propylene or a C4-C10 alpha-olefin having an ethylene content ranging from 15 to 85 wt % and an intrinsic viscosity of the fraction soluble in xylene ([η]2) of at least 1.4 dl/g; wherein the ratio of the intrinsic viscosity value of propylene polymer (1) to that of olefin polymer (2) ([η]/[η]2) ranges from 0.45 to 1.6; and (B) 10-35 wt % of a at least one filler selected among calcium carbonate, talc, wollastonite or mixtures thereof.
Abstract:
A process for the preparation of propylene polymer compositions carried out in the presence of a catalyst system comprising (a) a solid catalyst component having average particle size ranging from 15 to 80 μm comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least two electron donor compounds one of which being present in an amount from 50 to 90% by mol with respect to the total amount of donors and selected from succinates and the other being selected from 1,3 diethers, (b) an aluminum alkyl and optionally (c) an external electron donor compound, and comprising the following steps: (i) contacting the catalyst components (a), (b) and optionally (c); (ii) pre-polymerizing up to forming amounts of polymer from about 0.1 up to about 1000 g per gram of solid catalyst component (a); (iii) polymerizing propylene producing a propylene (co)polymer being for at least 85% by weight of insoluble in xylene at 25° C. and (iv) in a successive step, carried out in gas-phase, polymerizing mixtures of ethylene with α-olefins CH2═CHR in which R is a hydrocarbon radical having 1-10 carbon atoms, to produce the said ethylene copolymer.