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 C4-C10 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 α-olefins CH2═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 catalyst component made from or containing Ti, Mg, chlorine, an amount of a first internal donor selected from esters of aliphatic monocarboxylic acids (EAA), and an amount of a second internal donor selected from cyclic ethers (CE), wherein the EAA/CE molar ratio ranges from 0.02 to less than 20.
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 (1ID) 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-aluminum 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:
Preparing propylene polymer compositions comprising 50 to 90% by weight of a propylene (co)polymer, and 10 to 50% by weight of an ethylene copolymer. The polymerization process includes, in the presence of a catalyst system: (i) a first step of polymerizing propylene to produce the propylene (co)polymer; and (ii) a successive gas-phase polymerization step performed in the presence of the propylene (co)polymer, ethylene, and one or more α-olefins to produce the ethylene copolymer. The catalyst system contains the product obtained by contacting: (a) a solid catalyst component comprising at least two internal electron donor compounds, a succinate and a 1,3-diether; (b) an aluminum hydrocarbyl compound, and (c) optionally, an external electron donor compound.
Abstract:
The present invention relates to a slurry process for preparing an ethylene polymer having a melt flow ratio F/P, which is the ratio among the melt index value measured according to ASTM 1238 condition “F” and the melt index value measured according to ASTM 1238 condition “P” of equal to or lower than 27, carried out in two or more stages of polymerization at temperatures in the range from 60 to 120° C., in which at least two of the said two or more polymerization stages are carried out under different amounts of molecular weight regulator, said process being carried out in the presence of (A) a solid catalyst component comprising Ti, Mg, halogen, 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 0.3 cm3/g and a surface area determined by BET method, of lower than 100 m2/g, and being further characterized by the fact that more than 50% of the titanium atoms are in a valence state lower than 4 and (B) of an organoaluminum compound.
Abstract:
Spherical adducts comprising a MgCl2, an alcohol ROH in which R is a C1-C10 hydrocarbon group, present in a molar ratio with MgCl2 ranging from 0.5 to 6 and less than 20% mol based on the mol of MgCl2 of a compound of formula Mg(OR1)2 in which R1 is selected from C1-C10 alkyl groups or R2CO groups in which R2 is selected from C1-C6 alkyl or aryl groups.
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) an aluminum hydrocarbyl compound, and(c) optionally an external electron donor compound.
Abstract:
Fibers comprising a polypropylene obtainable by a process comprising the steps of: (i) polymerizing propylene 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) an aluminum hydrocarbyl compound, and (c) optionally an external electron donor compound, to obtain a polypropylene precursor having a melt flow rate MFR1; (ii) subjecting the thus-obtained polypropylene precursor to visbreaking to obtain a visbroken polypropylene having a melt flow rate MFR2; (iii) spinning the visbroken polypropylene obtained in the previous step; wherein MFR2 is comprised between from 15 to 40 g/10 min, the ratio MFR2/MFR1 is comprised between 8 and 18, both MFR1 and MFR2 being measured according to ISO method 1133 (230° C., 2.16 kg).
Abstract:
A pre-polymerized catalyst component for the polymerization of olefins endowed with high activity and morphological stability comprises a non-stereospecific solid catalyst component containing Ti, Mg and a halogen, and an amount of an ethylene/alpha-olefin block (co)polymer ranging from 0.1 up to 5 g per g of said solid catalyst component, said prepolymerized catalyst component being characterized by a mercury porosity, due to pores having radius up to 1 μm, ranging from 0.15 to 0.5 cm3/g and by the fact that at least 55% of said porosity is due to pores having pore radius up to 0.2 μm.
Abstract:
Solid adducts comprising MgCl2 and an alcohol ROH in which R is a C1-C20 hydrocarbon group, in which the amount of alcohol ranges from higher than 42% to 60% by weight and the porosity determined with Hg method due to pores up to 1 μm and expressed in cm3/g, is such that the value of its ratio with the amount of alcohol in percentage falls above the straight line defined by the equation y=−0.0158x+1.03 in which y is the porosity of the adduct and x is the alcohol percentage by weight.