Abstract: A porous 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 selected from 1,3-diethers and the other being selected from succinates, characterized by the fact that the molar ratio ID/Ti is from 0.30 to 0.90, where ID is the total molar amount of succinate and 1,3-diether, the molar ratio of the 1,3-diether donor to the succinate donor is higher than, or equal to, 0.60.

Abstract: A process for the (co)polymerization of propylene carried out at a temperature ranging from 77 to 95° C. in the presence of a catalyst comprising the product obtained by reacting: —an organo-aluminium compound, with—-a solid catalyst component comprising Mg, Ti and electron donor compound selected from specific diolesters.

Abstract: A process for the preparation of high purity propylene polymers carried out in the presence of a catalyst comprising the product obtained by reacting:—an organo-aluminium compound, with—a solid catalyst component comprising Mg, Ti and electron donor compound selected from specific diolesters, said process being carried out employing an organo-aluminum/propylene ratio equal to or lower than 1.75 mmole/kg.

Abstract: A catalyst system comprising the product obtained by contacting (a) a solid catalyst component containing Mg, Ti, halogen and at least an electron donor compound selected from diolesters of a specific formula (b) an alkylaluminum cocatalyst and (c) an ester of formula R?OOC—(CR?2)m—COOR? in which m is an integer from 2 to 8, the R? groups, equal to or different from each other, are C1-C10 alkyl groups and the R? groups, independently, are hydrogen or C1-C15 hydrocarbon groups.

Abstract: Solid adducts comprising a MgCl2, ethanol and a compound (A), said compounds being present in molar ratios defined by the following formula MgCl2.(EtOH)n(A)p in which n is from 0.1 to 6, p ranges from 0.001 to 0.5 and A is a compound selected from cyclic hydrocarbon structures which are substituted with at least two hydroxy groups.

Abstract: A solid catalyst component for olefin polymerization, and in particular for the preparation of LLDPE, comprising Mg, Ti, halogen and an electron donor compound (ID) belonging to cyclic ethers having 3-6 carbon atoms, characterized by having the molar ratio Mg/Ti higher than 5, the molar ratio Mg/ID lower than 3, and by a specific X-ray diffraction spectrum.

Abstract: A catalyst system comprising the product obtained by contacting (a) a solid catalyst component containing Mg, Ti, halogen and at least an electron donor compound selected from 1,3-diethers; (b) an alkylaluminum cocatalyst; and (c) an ester of formula ROOC—(CH2)n—COOR in which n is an integer from 2 to 8, R groups, equal to or different from each other, are C1-C10 alkyl groups.

Abstract: Catalyst component for the polymerization of olefins CH2?CHR in which R is hydrogen or a hydrocarbyl radical with 1-12 carbon atoms, comprising Mg, Ti, halogen and two electron donor compounds one of which selected those of formula (I) wherein: R2, equal to or different from each other, are hydrogen atoms or C1-C20 hydrocarbon radicals optionally containing heteroatoms belonging to groups 13-17 of the periodic table of the elements or alkoxy groups of formula —OR1, two or more of the R2 groups can be connected together to form a cycle; R1, equal to or different from each other, are C1-C20 hydrocarbon radicals optionally containing heteroatoms belonging to groups 13-17 of the periodic table of the elements, with the proviso that at least one of R2 is —OR1 and the other being selected from succinates of formula (II): wherein the radicals RI and RII, equal to or different from each other, are a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containi

Abstract: Catalyst component for the polymerization of olefins CH2?CHR in which R is hydrogen or a hydrocarbyl radical with 1-12 carbon atoms, comprising Mg, Ti, halogen and two electron donor compounds one of which selected from alkoxybenzenes and the other being selected from those of formula (II) where RI and RII are the same or different and are hydrogen or linear or branched C1-C18 hydrocarbon groups which can also form one or more cyclic structures; RIII groups, equal or different from each other, are hydrogen or C1-C18 hydrocarbon groups; RIV groups equal or different from each other, have the same meaning of RIII except that they cannot be hydrogen; each of RI to RIV groups can contain heteroatoms selected from halogens, N, O, S and Si.

Abstract: A process for the preparation of propylene polymer compositions comprising from 50 to 90% by weight of a propylene 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 being carried out in the presence of a specific catalyst system, is also characterized by the following step: (i) contacting the catalyst components (a), (b) and optionally (c) for a period of time ranging from 0.1 to 120 minutes, at a temperature ranging from 0 to 90° C.; (ii) polymerizing propylene in the optional presence of ethylene and/or C4-C10 alpha olefins producing a propylene (co)polymer being for at least 85% by weight of insoluble in xylene at 25° C. and (iii) in a successive step, carried out in gas-phase, in the presence of the product coming from (ii), polymerizing mixtures of ethylene with a-olefins CH2?CHR in which R is a hydrocarbon radical having 1-10 carbon atoms, to produce an ethylene copolymer.

Abstract: Solid adducts comprising a MgCl2, ethanol and a compound (A), said compounds being present in molar ratios defined by the following formula MgCl2.(EtOH)n(A)p in which n is from 0.1 to 6, p ranges from 0.001 to 0.5 and A is a compound selected from cyclic hydrocarbon structures which are substituted with at least two hydroxy groups.

Abstract: Process for the preparation of ethylene polymers having narrow MWD characterized by a F/E ratio lower than 35 carried out in the presence of a catalyst system comprising (a) a solid catalyst component comprising Ti atoms that are substantially in the +4 oxidation state, Mg, Cl, and optionally OR groups and internal donors in which R is a C1-C20 hydrocarbon group, in which the OR/Ti molar ratio is equal to or lower than 0.35 and the internal donor/Ti ratio is lower than 1, (b) an aluminum alkyl compound and (c) a compound selected from alkoxybenzenes of specified formula.

Abstract: Disclosed is a method for making LLDPE grades having different xylene solubles or hexane extractables with the same Ziegler-Natta catalyst by varying the amount of alkylaluminum used for polymerization. The method comprises copolymerizing ethylene with a C3-10 ?-olefin in the presence of a Ziegler-Natta catalyst, an alkylaluminum, and an electron donor; determining the dependency of the xylene solubles or hexane extractables on the alkylaluminum/electron donor ratio; and adjusting the alkylaluminum/electron donor ratio to achieve a desired xylene solubles or hexane extractables.

Abstract: Disclosed is a process for making a linear low density polyethylene (LLDPE) having low gels. The process comprises copolymerizing ethylene with one or more C3-10 ?-olefins to produce an LLDPE resin which has a gel defect area less than 25 ppm. The copolymerization is performed in the presence of a Ziegler-Natta catalyst which comprises an MgCl2 support, a Ti(IV) complex, and a cyclic ether as an internal electron donor. The Ziegler-Natta catalyst has an Mg/Ti molar ratio greater than or equal to 7.

Abstract: A catalyst component comprising Ti, Mg, Al, Cl, and optionally ORI groups in which RI is a C1-C20 hydrocarbon group, optionally containing heteroatoms, up to an amount such as to give a molar ORI/Ti ratio lower than 0.5, characterized by the fact that substantially all the titanium atoms are in valence state of 4, that the porosity (PF), measured by the mercury method and due to pores with radius equal to or lower than 1 ?m, is at least 0.3 cm3/g, and by the fact that the Cl/Ti molar ratio is lower than 29. The said catalysts are characterized by high morphological stability under the low molecular weight ethylene polymerization conditions while at the same time maintaining characteristics of high activity.

Abstract: Catalyst precursors comprising Mg, Cl, Ti, and OR groups that are in molar ratios defined by the formula MgClnTip(OR)(2?n)+4p in which n is from 0.3 to less than 1.7, p is lower than 0.6, the molar ratio (OR)/Cl is lower than 4 and R is C1-C15 hydrocarbon groups. The said precursor, just upon activation with organo-Al compounds, are able to advantageously polymerize ethylene and alpha olefins, and that upon reaction with halogenating compounds generate in high yields catalyst components with high polymerization activity particularly in the polymerization of propylene also in combination with 1,3-diethers.

Abstract: A modified Ziegler-Natta catalyst system, a method for preparing the catalyst system, and a process for polymerizing an olefin in the presence of the catalyst system are disclosed. The catalyst system comprises a titanium compound, an aluminum compound, and a nitroso compound. Improved polyolefin properties, such as high molecular weight, are obtained.

Abstract: A method for preparing a titanium-containing Ziegler-Natta catalyst is disclosed. A dialkyl magnesium compound, a trialkyl aluminum compound, and a polymethylhydrosiloxane are first combined in a hydrocarbon solvent. That product is then combined with dry, alcohol-free magnesium chloride. A solid product from the reaction with the magnesium chloride component is isolated and washed with a hydrocarbon solvent. The washed solid product is then combined with an alkyl aluminum dichloride or a dialkyl aluminum chloride to give the catalyst. The catalyst is suitable for both slurry and gas-phase olefin polymerizations. Polyolefins produced with the catalyst have broad molecular weight distributions and narrow distributions of relatively large particles.

Abstract: A modified Ziegler-Natta catalyst system, a method for preparing the catalyst system, and a process for polymerizing an olefin in the presence of the catalyst system are disclosed. The catalyst system comprises a titanium compound, an aluminum compound, and a nitroso compound. Improved polyolefin properties, such as high molecular weight, are obtained.

Abstract: A modified Ziegler-Natta catalyst system, a method for preparing the catalyst system, and a process for polymerizing an olefin in the presence of the catalyst system are disclosed. The catalyst system comprises a titanium or vanadium compound, an aluminum compound, and an indazole. Improved comonomer incorporation and the ability to regulate molecular weight are achieved in the manufacture of polyolefins.