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:
Propylene polymer compositions comprising: A) from 70 wt % to 95 wt %, of a random copolymer of propylene with ethylene, containing from 1.5 wt % to 4.5 wt %, of ethylene derived units, having a content of fraction insoluble in xylene at 25° C. of not less than 93%; B) from 5 wt % to 35 wt %, of a copolymer of propylene with ethylene, containing from 7.0 wt % to 17.0 wt % of ethylene derived units; the sum A+B being 100; wherein the melt flow rate, MFR. (Melt Flow Rate according to ASTM 1238, condition L, i.e. 230° C. and 2.16 kg load) ranges from 40 g/10 min and 130 g/10 min; and wherein the relation (I) is fulfilled: 10
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:
A process and apparatus for producing olefin polymers are disclosed, comprising:a. polymerizing one or more olefins in the gas phase, in the presence of an olefin polymerization catalyst, whereby growing polymer particles flow along a cylindrically-shaped downward path in densified form under the action of gravity so as to form a densified bed of downward-flowing polymer particles b. allowing said polymer particles to flow through a restriction of the densified bed, such restriction being positioned in a restriction zone extending from the bed upward to a distance of 15% of the total height of the densified bed; and c. metering an antistatic agent through a feed line connected to the densified bed at a feed point being located in a feed zone extending from the top of the restriction upward, to a distance five times the diameter of the section of the densified bed above the restriction.
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 catalyst component for the polymerization of olefins comprising Mg, Ti and an electron donor compound of the following formula (I) in which the R groups equal to or different from each other, are C1-C15 hydrocarbon groups, the R1-R2 groups, equal to or different from each other, are hydrogen, halogen or C1-C15 hydrocarbon groups, optionally containing an heteroatom selected from halogen, P, S, N and Si, which can be fused together to form one or more cycles; n and m are integer from 0 to 3 with the proviso that at least one of them is different from 0 and that diisobutyl o-phenylenediacetate is excluded.
Abstract:
A propylene, ethylene, 1-butene terpolymer containing from 0.5 wt % to 2.2 wt % of ethylene derived units and from 6.0 wt % to 20.0 wt % of 1 butene derived units; wherein: i) the ratio C2 wt %/C4 wt % ranges from 0.09 to 0.06; wherein C2 wt % is the weight per cent of ethylene derived units and C4 wt % is the weight per cent of 1-butene derived units; ii) the Melt flow rate ranges from 0.4 to 54 g/10 min; iii) the xylene soluble fraction at 25° C. is lower than 15.0 wt % the minimum value being 5.0 wt %.
Abstract:
Propylene polymer compositions comprising: A) from 70 wt % to 95 wt %, of a random copolymer of propylene with ethylene, containing from 3.5 wt % to 6.5 wt % of ethylene derived units, having a content of fraction insoluble in xylene at 25° C. of not less than 93 wt %; B) from 5 wt % to 35 wt %, of a copolymer of propylene with ethylene, containing from 8.5 Wt % to 17.0 wt % of ethylene derived units; the sum A+B being 100; the melt flow rate ,MFR (ISO 1133 (230° C., 2.16 kg) ranges from 0.6 g/10 min to 20.2 g/10 min.
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.