Patents
Brevetti depositati, ottenuti ed estesi, durante l'attività di ricerca svolta nelle Società del gruppo Eni
1. US 5070051 03.12.1991
"Catalyst component and catalyst for the production of very high molecular weight polyolefins”
Abstract
A solid catalyst component for the low-pressure polymerization of ethylene and C3 -C10 alpha-olefins into very high molecular weight polyolefins is in the form of a spherical granular solid having a surface area of between 20 and 40 m2 /g, a mean pore radius of between 5,000 and 40,000 Å and a porosity of between 40 and 90 vol %, and is definable by the following formula (in atomic proportions:
X (1), Mg (1-8), Al (0.2-0.8), Cl (5-20), (Et+OEt+OR) (1-3);
where: X=Hf or Zr; Et=ethyl group; OEt=ethoxy group; and OR=alkoxy group containing from 2 to 8 carbon atoms in the linear or branched alkyl portion.
Such a catalyst component is obtained by preparing a solid spherical granular support by spray-drying an ethanolic solution of magnesium chloride, reacting said support with a hafnium or zirconium alkoxide or halogenalkoxide, and finally reacting the thus treated support with an alkyl aluminum chloride.
2. US 5278117 11.01.1994
“Supported catalyst for ethylene polymerization and the copolymerization if ethylene with alpha-olefins, its preparation and use”
Abstract
A supported Ziegler-Natta catalyst active in ethylene polymerization and in the copolymerization of ethylene with alpha-olefins consists of:
(A) a cocatalyst in the form of an organometallic compound of aluminium, and
(B) a solid catalyst component obtained by:
(i) impregnating a granular solid support with a solution of a titanium alcoholate and magnesium chloride in a liquid aliphatic hydrocarbon, followed by evaporation of the hydrocarbon solvent;
(ii) impregnating the support treated in (i) with a solution of magnesium chloride in a liquid aliphatic ester, followed by evaporation of the ester solvent; and
(iii) activating the support treated in (ii) by contact with an alkyl aluminium halide.
In a preferred embodiment, measured quantities of a silicon halide are introduced in stage (i) and/or (ii), this considerably improving catalytic activity. In a particular embodiment, zirconium or hafnium are introduced into the solid catalyst component (B) in addition to titanium, to obtain catalysts able to produce polyethylenes with a widened molecular weight distribution.
3. US 5320995 14.07.1994
"Catalyst for the polymerization of olefins”
Abstract
A catalyst for the polymerization of olefins, containing magnesium, chlorine, aluminium and at least one transition metal, in a dispersed or emulsified form within an inert diluent, is obtained by:
contacting, in an inert diluent, a magnesium dialkyl and aluminium trichloride, in a molar ratio equal or almost equal to 2/1, at a temperature lower than 105° C. to obtain a catalyst precursor in a suspended form, or at a temperature higher than 105° C. to form a catalyst precursor in the form of a colloidal emulsion, in the diluent used; and
contacting said suspended or emulsified precursor with at least one compound of a transition metal to form a catalyst in the form of a suspension or emulsion respectively.
4. US 7449528 11.11.2008
“Supported catalyst containing active titanium in the omo- co- and ter-polymerization of olefin unsaturated compounds”
Abstract
The present invention relates to a supported catalyst containing titanium, its preparation and it use in the homo-, co-, and ter-polymerization of olefin-unsaturated compounds. The present invention also relates to a catalytic system comprising a supported catalyst based on titanium and a co-catalyst selected from organo-derivatives of aluminum. More specifically, the present invention relates to catalyst supported on silica, obtained by reacting a titanium halocarboxylate and a magnesium halocarboxylate with an aluminum chloroakylderivative, in the presence of a carrier consisting of high porosity silica. The above reaction essentially takes place in the pores of the silica itself.
5. US 8772521 08.07.2014
"METALALKYL-ARENES AND PROCESSES FOR THE PREPARATION THEREOF"
Abstract
Metal alkyl-arene having general formula (I) or (Ia): M (marene). A1X,R, (I) M (m °-arene)Al XR (Ia) wherein: M represents zirconium (Zr), hafnium (Hf), or mixtures thereof, preferably Zirconium; —arene represents a benzene, or a benzene 10 substituted with from 1 to 6 linear or branched C-C alkyl groups, or mixtures thereof; —X represents a halogen atom selected from chlorine, bromine, fluorine, iodine, preferably chlorine; —R represents a linear or branched C-C alkyl group; —q is a number ranging from 2 to 6, preferably 3 for a metal alkyl-arene having general formula (I), 2 for a metal alkyl-arene having general formula (Ia); —r is a number ranging from 1 to 20, preferably 9 for a metal alkyl-arene having general formula (I), 6 for a metal alkyl-arene having general formula (Ia); —s is a number ranging from 1 to 6, preferably 2. Said metal alkyl-arene can be advantageously used for the preparation of Solid compo nents of catalysts for the (co)polymerization of C-olefins.
6. US 9334341 10.05.2016
"Catalyst of the Ziegler-Natta typefor the (co)polymerization of olefins with a high productivity"
Abstract
Solid catalyst with a high thermal stability for the (co)poly merization of C-olefins, comprising titanium, magnesium, at least one metal selected from hafnium and Zirconium, alumi num and chlorine, wherein at least 60% of the titanium is in oxidation state +3, and, when examined by means of XPS spectroscopy, has an absorption band characteristic of a bind ing energy ranging from 455 to 458 eV. Said catalyst, used in combination with a suitable co-catalyst in (co)polymerization processes of C-olefins at a high temperature, shows an improved productivity, a high incorporation of co-monomers in the copolymerization of ethylene and an increased thermal stability with respect to the systems so far in use.
7. US 9751959 05.09.2019
"CATALYST PRECURSOR AND CATALYST FOR THE HIGH - TEMPERATURE ( CO ) POLYMERIZATION OF ALPHA - OLEFIN"
Abstract
A precursor for the formation of catalysts for the ( co ) polymerization of a - olefins , comprising titanium , magne sium , at least one metal selected from hafnium and zirco nium , aluminum and chlorine , obtained with a process comprising treatment with a siloxane compound . Said solid precursor , used in combination with a suitable co - catalyst in high - temperature ( copolymerization processes of a - olefins , shows an improved productivity , a high incorporation of co - monomers in the copolymerization of ethylene and an increased thermal stability with respect to the systems so far in use .
8. US 10486144 26.11.2019
"SOLID CATALYST FOR THE ( CO ) POLYMERISATION OF A - OLEFINS AND PROCESS FOR THE PREPARATION THEREOF"
Abstract
An improved solid Ziegler - Natta type catalyst for the ( co ) polymerisation of ethylene and a - olefins , particularly in high - temperature processes , such as for example adiabatic solution processes and high - pressure adiabatic processes with elevated productivity , is provided . Said catalyst is obtained by means of an original process comprising dis solving in hydrocarbons , compounds of titanium , magne sium and optionally a metal selected from hafnium and zirconium , and reprecipitating them in two steps in succes sion , the first of which is chlorination and the second reduction .