Abstract: A “bridged” bis-cyclopentadienyl complex which can be advantageously used for the formation of a catalytic system active in the (co)polymerization of ethylene and other &agr;-olefins is represented by means of the following formula (II): wherein: M represents a metal selected from titanium, zirconium or hafnium; A′ and A″ each independently represent an anion containing an &eegr;5-cyclopentadienyl ring coordinated to M; R′ or R″ each independently represents a group of an anionic nature &sgr;-bound to the metal M; B represents an unsaturated bivalent organic residue having from 1 to 30 carbon atoms, bound, respectively, to the ring of group A′ and to the —CH2-methylene group by means of carbon atoms.

Abstract: A “bridged” bis-cyclopentadienyl complex which can be advantageously used for the formation of a catalytic system active in the (co)polymerization of ethylene and other a-olefins is represented by means of the following formula (II): 1

Abstract: A “bridged” bis-cyclopentadienyl complex which can be advantageously used for the formation of a catalytic system active in the (co)polymerization of ethylene and other &agr;-olefins is represented by means of the following formula (II): wherein: M represents a metal selected from titanium, zirconium or hafnium; A′ and A″ each independently represent an anion containing an &eegr;5-cyclopentadienyl ring coordinated to M; R′ or R″ each independently represents a group of an anionic nature a-bound to the metal M; B represents an unsaturated bivalent organic residue having from 1 to 30 carbon atoms, bound, respectively, to the ring of group A′ and to the —CH2— methylene group by means of carbon atoms.

Abstract: Bridged cyclopentadienyl derivatives having general formula (I)A--X--B (I)wherein:1) A is a monofunctional hydrocarbyl radical having general formula (II) ##STR1## 2) --X-- is the bridge between A and B and consists of a bifunctional radical selected from an alkylene group, a silanylene group, an alkyl substituted silaalkylene group, a siloxasilanylene group;3) B is a monofunctional hydrocarbyl radical selected from:e) any of the A radicals defined above,f) a cyclopentadienyl radical.

Abstract: Process for preparing elastomeric copolymers of ethylene-propylene (EPM) type and elastomeric terpolymers of ethylene-propylene-diene (EPDM) type with a propylene content comprised within the range of from 15 to 75%, carried out in the presence of metallocenes of formula (I) ##STR1##

Abstract: Catalytic component for the copolymerization of ethylene with alpha-olefins having general formula (I): ##STR1## wherein: A is a cyclopentadienyl derivative having general formula (II) ##STR2## B is selected from: 1) any of the cyclopentadienyl derivatives A defined above2) a monofunctional cyclopentadienyl radical (F) selected from cyclopentadienyl, indenyl, fluorenyl and the relative alkyl, aryl, trialkylsilyl substituted derivatives;Q, a bridge between A and B, is a bifunctional radical.

Abstract: A description follows of catalysts of the metallocene type which can be used in the (co)polymerization of alpha-olefins, particularly in the preparation of elastomeric copolymers of ethylene.

Abstract: Cyclopentadienyl derivatives are described having general formula (I) ##STR1## where R, R.sub.1, R.sub.2, R.sub.4, equivalent to or different from one another, are selected from: --H, alkyl radicals having a number of carbon atoms from 1 to 5, cycloalkyl radicals having a number of carbon atoms from 5 to 8, aryl and alkylaryl radicals having a number of carbon atoms from 6 to 8, aralkyl radicals having a number of carbon atoms from 7 to 9; n is an integer from 2 to 18; with the proviso that the number of R different from H does not exceed 2; with the exclusion of the compound having n=3, R.dbd.R.sub.1 .dbd.R.sub.2 .dbd.R.sub.4 .dbd.H. The invention a-so describes the process for the preparation of the above-mentioned cyclopentadienyl derivatives.

Abstract: Solid component of a catalyst for the synthesis of elastomeric Ethylene-Propylene copolymers typically amorphous, basically consisting of a Titanium compound supported on a solid component mainly consisting of MgCl.sub.2, prepared by a process which comprises putting a solution (I), basically consisting of an organometallic compound of Aluminium diluted with aliphatic hydrocarbons, in contact with a solution (II) containingan anhydrous Magnesium halide in a composition of solvents selected from halohydrocarbons and aromatic hydrocarbons and relative mixtures, in the presence of an Aluminium trihalide;a tetravalent Titanium compound having general formula Ti(OR).sub.4-n X.sub.n.

Abstract: In an improved process for producing elastomeric ethylene-propylene copolymers with a propylene content comprised within the range of from 22 to 38% by weight and a content of residual chlorine, coming from the co-catalyst, lower than 300 parts per million parts, the polymerization is carried out in suspension in the monomers in the liquid state, with vanadium triacetylacetonate and alkyl-Al compounds, and the obtained polymer is recovered without any washing steps.

Abstract: Catalytic components for copolymerizing ethylene with alpha-olefins, or alpha-olefins with one another, and possibly with a diene as a termonomer, suitable for producing saturated and unsaturated elastomeric copolymers are disclosed. The catalytic components are compounds obtained by the reaction of:(1) a magnesium compound having the formula:R'.sub.y MgX.sub.n (OR).sub.2-n(wherein R, R'=alkyl, cycloalkyl, aryl; X=Cl, Br; n is from 0 to 1.8, y is from 0 to 1, and n+y=2), or(2) a Mg-alcohol adduct;with a titanium compound having the formula:Ti(OR).sub.Z X.sub.4-Z'wherein X and R are as defined above and Z is from 0 to 1, the compounds being charcterized by a Mg/Ti ratio of from 0.5 to 50 and an OR/Ti ratio of from 0.7 to 10. The copolymers produced using these catalytic components are endowed with improved tension-set characteristics in the vulcanized state.

Abstract: Maleic anhydride is grafted onto unsaturated elastomeric terpolymers consisting of monomeric units coming from at least two different monomers having the formula R--CH.dbd.CH.sub.2 (R=hydrogen or an alkyl group containing from 1 to 6 carbon atoms) and from a conjugated or non-conjugated dienic monomer by mass reaction, which is carried out by heating at 120.degree.-350.degree. C. a mixture of said maleic anhydride with the terpolymer in the presence of a catalyst consisting of a compound having the formula:M.sub.n X.sub.zwherein:M=a metal of group VIII of the periodic system, and in particular Rh and Ru;X=a counterion,N=valence of the counterion; andZ=valence of the metal.

Abstract: Grafting of maleic anhydride, possibly together with styrene, on olefinic polymers, carried out in the presence of radical starters, characterized in that one operates with the polymer maintained in suspension of either an aliphatic, cycloaliphatic or aromatic ketone, containing from 3 to 22 carbon atoms.

Abstract: Catalyst components for the stereoregular polymerization of alpha-olefins, comprising a Ti halide and an electron-donor compound supported on an anhydrous magnesium dihalide and obtained by means of non-extractive treatments, with liquids having a dielectric constant at 20.degree. C. equal to or higher than 2, of compositions comprising an anhydrous Mg dihalide, the crystallites of which have an average size lower than 300 .ANG..The present invention refers to new catalyst components and the catalysts obtained therefrom for the polymerization of alpha-olefins Ch.sub.2 .dbd.CHR, wherein R is an alkyl radical with 1-4 C atoms or an aryl radical, and of mixtures of said alpha-olefins with minor amounts of ethylene.