Abstract:
A process for the preparation of random copolymer of propylene containing up to 6.0 % by weight of ethylene units, suitable for the manufacture of pipes, by copolymerizing propylene and ethylene in the presence of a catalyst system comprising the product obtained by contacting the following components: (a) a solid catalyst component 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 40 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) n aluminum hydrocarbyl compound, and (c) optionally an external electron donor compound.
Abstract:
A pre-polymerized catalyst component for the polymerization of olefins endowed with high activity and morphological stability comprises (i) a non-stereospecific solid catalyst component comprising Ti, Mg and a halogen and having a porosity, due to pores with radius up to 1 μm, ranging from 0.2 to 0.8 cm 3 /g and (ii) an amount of an ethylene/alpha-olefm block (co)polymer ranging from 0.1 up to 5g per g of said solid catalyst component (i), said pre-polymerized catalyst component being characterized by a mercury porosity due to pores up to 1 μm of less than 70% the mercury porosity value of the said non-stereospecific solid catalyst component (i).
Abstract:
A process for the preparation of propylene polymer compositions comprising from 50 to 90 % by weight of a propylene (co)polymer fraction insoluble in xylene at 25°C, and from 10 to 50% by weight of an ethylene copolymer fraction soluble in xylene at 25°C, said process comprising: (i) a first step of polymerizing propylene in the optional presence of ethylene and/or C 4 -C 10 alpha olefins, to produce a propylene (co)polymer being for at least 85% by weight insoluble in xylene at 25°C; and (ii) a successive step, carried out in gas-phase, in the presence of the product coming from step (i), of copolymerizing a mixture of ethylene with one or more ±-olefins CH 2 =CHR in which R is a hydrocarbon radical having 1-10 carbon atoms, to produce an ethylene copolymer; the process being carried out in the presence of a catalyst system comprising: the product obtained by contacting: (a) a solid catalyst component comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least two internal electron donor compounds one of which being present in an amount from 35 to 90% by mol with respect to the total amount of donors and being selected from succinates and the other being selected from 1,3-diethers, the total amount of internal electron donor compounds being lower than 14.0% by weight with respect to the total weight of the solid catalyst component; with (b) an aluminum hydrocarbyl compound, and optionally with (c) an external electron donor compound.
Abstract:
A process for the preparation of high purity propylene polymers carried out in the presence of a catalyst comprising the product obtained by contacting: (a) a solid catalyst component comprising Mg, Ti and at least a first internal electron donor compound (HD) selected among the succinates and a second internal electron donor compound (2ID) selected among the 1,3-diethers, wherein the molar ratio of first internal donor over second internal donor 1ID:2ID is comprised between 4:6 and 9:1, with (b) an organo-aluminium compound, and optionally with (c) an external electron donor compound, said process being carried out at a temperature equal or higher than 78° C. and by employing a molar ratio of organo-aluminum compound over solid catalyst component (b):(a) of lower than 5.
Abstract:
Process for the preparation of solid particles of a magnesium-chloride alcohol adduct comprising (a) forming an emulsion between a MgCl2 .alcohol adduct in molten form and a liquid phase which is immiscible with the said adduct in the presence of a polyalkyl-methacrylate used as a solution having viscosity ranging from 100 to 5000 mm2/s and (b) rapidly cooling the emulsion to solidify the disperse phase and collecting the solid adduct particles.
Abstract:
A solid adduct comprising magnesium chloride and ethanol in which the moles of ethanol per mole of magnesium chloride range from 2 to 5 and in which the ratio between the average pore radius measured in Angstrom of said adduct, determined by mercury porosity, and the moles of ethanol, is higher than 500.