Abstract: A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2=CHL, where L is an alkyl, cycloalkyl or aryl radical with 1-10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.

Abstract: A process for continuously producing an elastomeric composition includes metering at least one elastomer, at least one filler, and at least one minor ingredient; feeding the at least one elastomer, the at least one filler, and the at least one minor ingredient into at least one extruder; mixing and dispersing the at least one filler and the at least one minor ingredient into the at least one elastomer using the at least one extruder; obtaining a subdivided product from a resulting elastomeric composition discharged from the at least one extruder; accumulating an amount of the subdivided product; and stirring the accumulated amount of the subdivided product. An apparatus for continuously producing an elastomeric composition includes at least one extruder, at least one first metering device, at least one second metering device, at least one device for obtaining a subdivided product, and at least one accumulating and stirring device.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: System for producing models of tyres which are different from each other, comprising:—a building unit (2) comprising a plurality of operating stations (5, 6, 7, 8, 9), each designed to assemble at least one corresponding structural component on at least one model of tyre being produced;—a vulcanizing unit (3), having vulcanizing moulds (24, 25, 26, 27, 28, 29) for the built tyres;—a unit for producing a plurality of mixtures, comprising at least one extruder unit, which continuously supplies at least one of the said operating stations with at least one mixture suitable for making the said at least one structural component.

Abstract: Product in subdivided form comprising: a) at least one additive for crosslinkable elastomeric compositions; and b) a thermoplastic binder comprising at least (i) one copolymer ethylene with at least one aliphatic or aromatic &agr;-olefin, and optionally a polyene, said copolymer being characterized by a molecular weight distribution (MWD) index of less than 5 and a melting enthalpy (&Dgr;Hm) of at least 30 J/g. Said product in subdivided form is particularly useful for preparing crosslinkable elastomeric compositions.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: re for vehicle wheels, comprising at least one component made of crosslinked elastomeric material, in which said component includes an elastomeric composition comprising: a) at least one dicnc clastomcric polymer; b) at least one copolymer of ethylene with at least one aliphatic &agr;-olefin, and optionally a polyene, said copolymer being characterized by a molecular weight distribution (MWD) index of less than 5, preferably between 1.5. and 3.5, and by a melting enthalpy (&Dgr;aHm) of not less than 30 J/g, preferably between 34 J/g and 130 J/g. Preferably, said component including said composition is a tyre tread band.

Abstract: Tyre for vehicle wheels, comprising at least one element made of crosslinked elastomeric material, in which said element includes an elastomeric composition comprising: (a) at least one elastomeric homopolymer or copolymer of 1,3-butadiene; (b) at least one copolymer of ethylene with at least one aromatic &agr;-olefin, said copolymer being essentially free of side chains containing ethylenic double bonds. Preferably, said element including said composition is a tread band of the tyre. The above (mentioned elastomeric composition makes it possible to prepare tread bands having both a low rolling resistance at the normal working temperatures of the tyre (40° C.-70° C.) and a high roadholding when the tread band is thermally stressed above these temperatures.

Abstract: A tyre for a vehicle wheel includes a carcass structure, a pair of inextensible annular structures, a belt structure, a tread band, a pair of sidewalls, and at least one coating layer. The carcass structure includes at least one carcass ply shaped in a substantially-toroidal configuration and is engaged, by opposite circumferential edges, to the inextensible annular structures. The belt structure includes at least one belt strip applied in a circumferentially-external position relative to the carcass structure. The tread band is circumferentially superimposed on the belt structure. The sidewalls are applied to opposite sides of the carcass structure. The at least one coating layer includes crosslinked elastomeric material placed in a radially-internal position relative to the at least one carcass ply. The at least one coating layer is obtained by crosslinking at least one elastomer comprising hydrolyzable silane groups. A related process for producing the tyre is also disclosed.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: Method for improving processability and storage stability of a silica filled elastomeric composition, said method comprising adding to said composition a thermoplastic polymer having a main hydrocarbon chain to which hydroxy groups are linked, said polymer having a weight-average molecular weight of at least 8,000. Preferably, the method further comprises adding to the silica filled elastomeric composition a polymer containing functional groups reactive with said hydroxy groups. The polymer containing hydroxy groups is highly effective in reducing and stabilizing viscosity of the composition, even when used in relatively low amounts, while maintaining or even enhancing the reinforcement effect of silica on the elastomeric composition. The resulting composition is particularly suitable to produce tyres, and particularly tyre treads.

Abstract: An elastomeric composition includes at least one elastomeric diene polymer, at least one thermoplastic polymer, and at least one polymer comprising functional groups. The at least one thermoplastic polymer comprises a main hydrocarbon chain. Hydrophilic groups are linked to the main hydrocarbon chain. The functional groups are reactive with the hydrophilic groups. The composition may also include at least one reinforcing filler. The at least one reinforcing filler may include carbon black, silica, or both carbon black and silica. The composition may further include a silica coupling agent, a sulfur-based vulcanizing agent, or both a silica coupling agent and a sulfur-based vulcanizing agent. A tire for vehicle wheels including at least one element including an elastomeric material, where the at least one element include the composition, is also disclosed.

Abstract: Catalysts for the polymerization of olefins comprise the product of the reaction between: (A) a titanium, zirconium or hafnium product with substituted cyclopentadiene ligands, (B) a mixture of two organometallic aluminium compounds, with at least one of the groups bound to the aluminium being other than a linear alkyl, and (C) water. When used in the polymerization of olefins, these catalysts show higher activities, at short residence times, than corresponding catalysts obtained from the individual components of the above-mentioned mixtures of aluminium compounds.

Abstract: Ethylene based polymers having high molecular weights can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of catalysts comprising silicon bridged metallocenes having a particular ligand system containing a heteroatom.

Abstract: Catalysts for the polymerization of olefins are disclosed, comprising the product obtainable by contacting: (A) a bridged and/or substituted cyclopentadienyl compound of Ti, Zr or Hf; (B) one or more organometallic aluminium compounds of formula (II): AlR43−zHz wherein the substituents R4, same or different from each other, are linear or branched, saturated or unsaturated C1-C20 alkyl or alkylaryl radicals, optionally containing Si or Ge atoms, wherein at least one of the substituents R4 is different from a straight alkyl group; z is 0 or 1; and (C) water, the molar ratio between the organometallic aluminium compound and water being comprised between 1:1 and 100:1; said catalyst being obtainable by a process comprising the following steps: (i) contacting component (A) with part of component (B) in the absence of component (C); (ii) contacting part of component (B) with component (C) in the absence of component (A) and successively (iii) contacting the products obtained in steps (i) and (ii).

Abstract: Amorphous copolymers of ethylene with propylene, and optionally with minor amounts of polyenes, have the following characteristics: (A) the % content by mole of propylene in the copolymer (%P) and the triads ratio EPE/(EPE+PPE+PPP) satisfy the following relationship: 0.01%P+EPE/(E?E+PPE+PPP)≧1 (B) less than 2% of the CH2 groups in the chain are in sequences (CH2)n, wherein n is an even number. These copolymers are obtainable by operating in the presence of particular metallocene catalysts having two fluorenyl groups joined together through a bridging group.

Abstract: Catalysts for the polymerization of olefins are disclosed, comprising the product obtainable by contacting: (A) a bridged and/or substituted cyclopentadienyl compound of Ti, Zr or Hf; (B) one or more organometallic aluminium compounds of formula (II): AlR 43−z Hz wherein the substituents R4, same or different from each other, are linear or branched, saturated or unsaturated C1-C20 alkyl or alkylaryl radicals, optionally containing Si or Ge atoms, wherein at least one of the substituents R4 is different from a straight alkyl group; z is 0 or 1; and (C) water; the molar ratio between the organometallic aluminium compound and water being comprised between 1:1 and 100:1; said catalyst being obtainable by a process comprising the following steps: (i) contacting component (A) with part of component (B) in the absence of component (C), (ii) contacting part of component (B) with component (C) in the absence of component (A) and successively (iii) contacting the products obtained in steps (i) and (ii).

Abstract: A process for the preparation of amorphous copolymers of ethylene with &agr;-olefins and optionally minor amounts of polyenes are disclosed, which have the following characteristics: (A) the % by mole content of &agr;-olefin in the copolymer (%&agr;) and the ratio between the molar amount of &agr;-olefin diads and the molar content of &agr;-olefin in the copolymer (&agr;&agr;/&agr;) satisfy the following relationship: (%&agr;)−250 (&agr;&agr;/&agr;)≧10 (B) less than 2% of the CH2 groups in the polymeric chain are in sequences (CH2)n, wherein n is an even number. These copolymers are obtained by operating in the presence of particular metallocene-based catalysts having two fluorenyl groups joined together through a bridging group.

Abstract: Novel copolymers of ethylene with propylene and optionally with minor proportions of a diene or polyene having good elastomeric properties in their uncured state. The copolymers are characterized by a structure in which the propylene is partially present in the form of short isotactic sequences. Tension set values (200%) of less than 15 are obtained by when the ethylene/propylene ratio has specific values and the intrinsic viscosity values are higher than 3.

Abstract: The present invention relates to bituminous compositions, particularly suitable for paving and building waterproofing, comprising a bitumen and a copolymer of ethylene with propylene and/or other alpha-olefins and optionally with smaller proportion of a diene or polyene. The copolymer is besides characterized by a very low crystallinity, intrinsic viscosity higher than 1.5 dl/g and by a content of propylene units or of the alpha-olefin in form of triads comprised between 4 and 50% of the propylene or of the alpha-olefin, with at least 70% of said triads having isotactic structure.