Heavy-load tires having a rubber composition that delays irregular wear
The present invention relates to tires suitable for bearing heavy loads, and to the use of a rubber composition to form the treads of such tires which delays the appearance of irregular wear on the treads of such tires during travel. The invention applies to tires for motor vehicles, such as heavy vehicles, construction vehicles or aircraft. The rubber composition comprises: an elastomeric matrix comprising majoritarily at least one diene elastomer having at one or more of its chain ends a functional group which is active for coupling to a reinforcing white filler, a reinforcing filler comprising at least 50% by weight a reinforcing white filler, and a reinforcing white filler/functionalized diene elastomer bonding agent. The present invention relates to tires suitable for bearing heavy loads, and to the use of the rubber composition to delay the appearance of irregular wear on the treads of such tires during travel. The invention applies to tires for motor vehicles, such as heavy vehicles, construction vehicles or aircraft.
1. A heavy-vehicle tire comprising a tread which is formed from a cross-linked rubber composition, the composition comprising:
(a) an elastomeric matrix comprising a functionalized diene elastomer co-polymer formed from a conjugated diene monomer and a vinyl-aromatic compound, the co-polymer having a glass transition temperature between −70° C. and −20° C. and a mass content of vinyl-aromatic units of from 10% to 50%, the elastomer having at one or more of its chain ends a functional group which is active for coupling to a reinforcing white filler, the functional group being selected from the group consisting of a silanol group and a polysiloxane block having a silanol end;
(b) a reinforcing filler comprising at least 50% by weight of silica, the silica having a CTAB specific surface area of from 80 m 2 /g to 260 m 2 /g; and
(c) a reinforcing white filler/functionalized diene elastomer bonding agent.
2. The heavy-vehicle tire according to claim 1 , wherein the reinforcing white filler/functionalized diene elastomer bonding agent is a polysulphurized alkoxysilane.
3. The heavy-vehicle tire according claim 1 , wherein the composition further comprises an alkyl alkoxysilane covering agent for the reinforcing white filler.
4. The heavy-vehicle tire according to claim 1 wherein the silica is present in the composition in an amount of from 20 phr to 80 phr (parts by weight of the elastomeric matrix).