Pirelli Pneumatici S.p.a.

Pirelli Coordinamento Pneumatici S.p.a.

Angela Amaddeo

Luciano Garro

Antonio Serra

Marco Nahmias Nanni

Mario Isola

Roberto Pessina

Fabrizia Sala

An elastomeric composition includes at least one diene elastomeric polymer, at least one salt or oxide of a transition metal belonging to groups IIIA, IVA, VA, VIA, VIIA, or VIIIA of the Periodic Table, at least one vulcanization accelerator, sulphur or derivatives thereof, and at least one reinforcing filler. The elastomeric composition is substantially free of zinc or derivatives thereof. A tire for a vehicle wheel including at least one component including the elastomeric composition and a tread band for a tire including the elastomeric composition are also disclosed. The at least one diene elastomeric polymer may include a glass transition temperature lower than 20&#xb0; C. The at least one salt of a transition metal may be an organic or inorganic metal salt. The at least one oxide of a transition metal may include one or more of: cobalt oxide; cerium oxide; molybdenum oxide; manganese oxide; and iron oxide.

Elastomeric composition including at least one salt or oxide of a transition metal and tyre and tread band including the composition

A tire for a motor vehicle includes at least one carcass ply, a belt structure radially external to the at least one carcass ply, a tread band radially external to the belt structure, a pair of sidewalls axially-external to the at least one carcass ply, and a pair of beads. The beads include bead wires or circumferentially-inextensible annular inserts. Opposite lateral edges of the at least one carcass ply are associated with respective beads. The at least one carcass ply includes a first composition having an elastic modulus at 70&#xb0; C. less than or equal to 5.0 MPa and a viscous modulus at 70&#xb0; C. less than or equal to 0.50 MPa. The sidewalls include a second composition having an elastic modulus at 70&#xb0; C. greater than or equal to 3.5 MPa and a viscous modulus at 70&#xb0; C. less than or equal to 0.50 MPa.

Motor vehicle tire with low rolling resistance

A low rolling resistance tire for vehicles includes a carcass structure, a belt structure coaxially extending around the carcass structure, and a tread coaxially extending around the belt structure and being externally provided with a rolling surface designed to contact the ground. The tread includes a vulcanized polymer base having at least a first silica-based reinforcing filler. The first silica-based reinforcing filler has an average projected area of aggregates, measured before incorporation into the polymer base, lower the 20,000 nm , a dispersion index in the polymer base not lower than 97%, and an average projected area of the aggregates, measured after incorporation into the polymer base, between 8,500 nm and 18,000 nm .

Low rolling resistance tire for vehicles

A low rolling resistance tire ( ) for vehicles is described which comprises at least one belt layer ( ) coaxially extending around at least one carcass ply ( ), a composite tread ( ) coaxially extending around the belt layer ( ) and comprising a radially outer layer ( ) and a radially inner layer ( ), wherein the ratio between the modulus of elasticity E' at 70&deg; C. of the radially inner layer ( ) and the modulus of elasticity E' at 70&deg; C. of the radially outer layer ( ) is comprised between 1.1 and 3, and the ratio between the value of tang&dgr; at 70&deg; C of the radially inner layer ( ) and the value of tang&dgr; at 70&deg; C. of the radially outer layer ( ) is lower than 0.8. Advantageously, the tire ( ) achieves a better compromise between the characteristics of rolling resistance, handling and comfort with respect to what is obtainable from known tires for the same type of use.

Low rolling resistance tire for vehicles having a composite tread

Vulcanizable rubber composition, in particular for low rolling resistance for vehicle tires

A process for producing a vulcanizable rubber composition containing silica and carbon black, comprises the step of intimately mixing at a temperature of from 130&deg; to 180&deg; C. at least a first cross-linkable unsaturated chain polymer with a first carbon black-based reinforcing filler, so as to obtain a first rubber composition capable of allowing a subsequent effective dispersion of a second silica-based reinforcing filler and of a second cross-linkable unsaturated chain polymer. The rubber composition thus obtained shows a homogeneous dispersion of the reinforcing fillers, in particular of the silica-based reinforcing filler, constant physical-mechanical characteristics, and improved drawability, and is particularly suitable for the manufacture of tire treads with low rolling resistance.

Process for producing a vulcanizable rubber composition including carbon black-based and silica-based reinforcing fillers

A vulcanizable rubber composition is described comprising a cross-linkable unsaturated chain polymer base including natural rubber, at least a copolymer obtainable by polymerizing a conjugated diolefin with a vinyl aromatic hydrocarbon, and a main carbon black-based reinforcing filler, wherein: a) the copolymer is obtainable by polymerizing in 1,2 form with the vinyl aromatic hydrocarbon at least 50% by weight of the conjugated diolefin, so as to obtain in the copolymer a quantity of from 30% to 70% by weight to the total weight of the same of an olefin fraction having a 1,2 structure, and b) the carbon black has a DBP absorption value measured according to ISO 4656-1 equal to at least 110 ml/100 g, a reduction in the DBP absorption value measured after compression according to ISO 6894 equal to at least 25 ml/100 g and a surface area measured by means of CTAB absorption according to ISO 6810 not greater than 120 m.sup.2 /g.

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Arienzo, Italy

Angela Amaddeo