Abstract: Process for the preparation of a diene polymer or a random vinyl arene-diene copolymer comprising anionically (co)polymerizing at least one conjugated diene monomer, optionally in the presence of at least one vinyl arene, in the presence of at least one hydrocarbon solvent, at least one lithium-based initiator and at least one organic compound containing at least one nitrox- ide group having general formula (I) or (II): wherein: R1, R2, R3 and R4, mutually identical or different, represent a hydrogen atom; or are selected from C1-C20, preferably C1-C8, linear or branched alkyl groups optionally containing heteroatoms such as, for example, oxygen, nitrogen, sulphur, optionally substituted cycloalkyl groups, optionally substituted C1-C20, preferably C1-C8, linear or branched alkoxy groups, optionally substituted aryl groups; -x is an integer ranging from 0 to 7, preferably ranging from 4 to 5; -y is an integer ranging from 1 to 3, preferably ranging from 1 to 2.

Abstract: Process for the preparation of a diene polymer or a random vinyl arene-diene copolymer comprising anionically (co)polymerising at least one conjugated diene monomer, optionally in the presence of at least one vinyl arene, in the presence of at least one hydrocarbon solvent, at least one lithium-based initiator and at least one organic compound containing at least one nitroxide group having general formula (I) or (II): wherein: R1, R2, R3 and R4, mutually identical or different, represent a hydrogen atom; or are selected from C1-C20, preferably C1-C8, linear or branched alkyl groups optionally containing heteroatoms such as, for example, oxygen, nitrogen,sulphur,optionally substituted cycloalkyl groups, optionally substituted C1-C20, preferably C1-C8, linear or branched alkoxy groups, optionally substituted aryl groups; ?x is an integer ranging from 0 to 7, preferably ranging from 4 to 5; ?y is an integer ranging from 1 to 3, preferably ranging from 1 to 2.

Abstract: A process for the preparation of branched polybutadiene having a high content of 1,4-cis units which comprises polymerizing butadiene in the presence of at least one organic solvent, and in the presence of: a) a catalytic system prepared in situ including: (a1) at least one neodymium carboxylate, (a2) at least one alkyl compound of aluminum, (A3) at least one alkyl compound of aluminum containing at least one halogen atom, and b) at least one organic ester containing at least one halogen atom. Said branched polybutadiene having a high content of 1,4-cis units, depending on the branching degree and molecular weight distribution, can be advantageously used in various applications ranging from the modification of plastic materials [production, for example, of high impact polystyrene (HIPS)] to the production of tires, in particular the production of treads and/or of sidewalls of tires.

Abstract: A process for the preparation of an elastomeric polymer of ethylene which comprises polymerizing, in suspension, a mixture of monomers comprising ethylene, at least one a-olefin having from 3 to 12 carbon atoms, possibly at least one non-conjugated diene having from 4 to 20 carbon atoms, in the presence of a catalytic system comprising: —a suspension in oil of at least one catalyst selected from compounds containing vanadium; —at least one co-catalyst, as such, selected from compounds containing aluminum; at least one activator, as such, selected from compounds containing chlorine.

Abstract: A process for the preparation of branched polybutadiene having a high content of 1,4-cis units which comprises polymerizing butadiene in the presence of at least one organic solvent, and in the presence of: a) a catalytic system prepared in situ including: (a1) at least one neodymium carboxylate, (a2) at least one alkyl compound of aluminum, (A3) at least one alkyl compound of aluminum containing at least one halogen atom, and b) at least one organic ester containing at least one halogen atom. Said branched polybutadiene having a high content of 1,4-cis units, depending on the branching degree and molecular weight distribution, can be advantageously used in various applications ranging from the modification of plastic materials [production, for example, of high impact polystyrene (HIPS)] to the production of tyres, in particular the production of treads and/or of sidewalls of tyres.

Abstract: A process for the preparation of an elastomeric polymer of ethylene which comprises polymerizing, in suspension, a mixture of monomers comprising ethylene, at least one a-olefin having from 3 to 12 carbon atoms, possibly at least one non-conjugated diene having from 4 to 20 carbon atoms, in the presence of a catalytic system comprising:—a suspension in oil of at least one catalyst selected from compounds containing vanadium;—-at least one co-catalyst, as such, selected from compounds containing aluminium; at least one activator, as such, selected from compounds containing chlorine.

Abstract: Promoters are described for vanadium-based catalysts used in the (co)polymerization of olefins and, in particular, in the production of ethylene/propylene (EPR) or ethylene/propylene/diene (EPDM) elastomeric copolymers. The promoters of the present invention belong to the group of compounds having general formula I: wherein: “X” represents a (—CO—) carbonyl or (—SO2—) sulfonyl group; “n” is 0 or 1; R? is an alkyl or alkylaryl group having from 1 to 20 carbon atoms; R?=R?, H.

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.

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 presente of a carrier consisting of high porosity silica. The above reaction essentially takes place in the pores of the silica itself.

Abstract: Promoters are described for vanadium-based catalysts used in the (co)polymerization of olefins and, in particular, in the production of ethylene/propylene (EPR) or ethylene/propylene/diene (EPDM) elastomeric copolymers. The promoters of the present invention belong to the group of compounds having general formula I: wherein: “X” represents a (—CO—) carbonyl or (—SO2—) sulfonyl group; “n” is 0 or 1; R? is an alkyl or alkylaryl group having from 1 to 20 carbon atoms; R?=R?, H.

Abstract: Catalytic composition effective in the hydrogenation of olefinic double bonds prepared by reaction between: (A) at least one cyclopentadienyl complex of a transition metal having general formula (I) (R)(R1)M1(R2)(R3) wherein R is an anion containing an &eegr;5-cyclopentadienyl ring coordinated to M1; M1 is selected from titanium, zirconium and hafnium; R2 and R3, the same or different, are organic or inorganic anion groups bound to M1; R1 is selected from cyclopentadienyl and R2; (B) an alkylating composition essentially consisting of: (b1) an organometallic compound having general formula (II) M2 (R4)(R5), wherein M2 is selected from Zn and Mg; (b2) an organoderivative of aluminum having general formula (III) Al(R6)3.

Abstract: Effective catalyst in the selective hydrogenation of olefinic double bonds, comprising the reaction product between: (A) at least one cyclopentadienyl complex of a transition metal having the following general formula (I): (R)M(R1)(R2)(R3)  (I)  wherein: M is selected from titanium, zirconium and hafnium, preferably titanium; R is an anion containing an &eegr;5-cyclopentadienyl ring co-ordinated to M; and each R1, R2 or R3, independently, represents an organic or inorganic group of an anionic nature bound to M, and may, particularly, be hydride, halide, a C1-C8 alkyl group, a C3-C12 alkylsilyl group, a C5-C8 cycloalkyl group, a C6-C10 aryl group, a C1-C8 alkoxyl group, a C1-C8 carboxyl group, a C2-C10 dialkylamide group and a C4-C20 alkylsilylamide group;  the above compound (I) being solid, supported or dispersed in an inert liquid medium; and (B) at least one organometallic compound of magnesium having the following formula (II): Mg(R4)n(R5)(2−n)  (II)  whe

Abstract: Catalytic composition effective in the selective hydrogenation of olefinic double bonds prepared by the reaction between:(A) at least one bis(cyclopentadienyl)Titanium derivative having the general formula (I) (C.sub.5 H.sub.5).sub.2 Ti(R) (R.sub.1) wherein R and R.sub.1, the same or different, are halogens; the above compound (I) being solid or dispersed in one or more non-solvent diluents;(B) at least one organo derivative having general formula (II) M(R.sub.2) (R.sub.3) wherein M is selected from Zinc and Magnesium, and R.sub.2 and R.sub.3, the same or different, are selected from C.sub.1 -C.sub.16 alkyls;(C) at least one modifier.

Abstract: A catalyst for the (co)polymerization of ethylene is obtained by a process comprising the contact of the following components (A), (B), (C) and (D) in the respective molar ratios (1):(0.5-2):(0-25):(0-15):(A): a bivalent arene of titanium having the formulaTi (.eta..sup.6 -arene)(AlR.sub.x X.sub.4-x).sub.2 ;wherein: "arene" indicates benzene, or benzene substituted with from 1 to 6 C.sub.1 -C.sub.10 alkyl groups;each X independently represents a chlorine, bromine or fluorine atom;R is a C.sub.1 C.sub.10 alkyl group, linear or branched; "x" is a number varying from 0.5 to 2.