Rubber composition comprising at least one silica as inorganic reinforcing filler

A process for preparing a rubber composition based on at least one elastomer, a reinforcing inorganic filler, an agent for coupling the elastomer to the reinforcing inorganic filler, and a crosslinking system, the process comprising the following steps:

• contacting the at least one elastomer, the at least one reinforcing inorganic filler, and the at least one agent for coupling the elastomer to the reinforcing inorganic filler to make a mixture, wherein the content of reinforcing inorganic filler is within a range extending from 80 to 150 phr,
• wherein the reinforcing inorganic filler comprises at least one silica S having:
• a CTAB specific surface area SCTAB within a range extending from 40 to 300 m2/g;
• a difference between a BET specific surface area SBET and the CTAB specific surface area SCTAB of greater than or equal to 35 m2/g;
• an aluminium content WAl within a range extending from 0.5 to 7.0% by weight relative to a weight of the silica S;
• a width of the aggregate size distribution Ld, measured by centrifugal sedimentation, of greater than or equal to 1.5;
• and
• a median aggregate diameter d50, measured by centrifugal sedimentation, such that for a given value of CTAB specific surface area SCTAB and a given aluminium content WAl, a magnitude A is defined by the following equation (I):
• A=[d50]+0.782×[SCTAB]−8.524×[WAl] (I)
• in which:
• [d50] is the numerical value of d50, expressed in nm;
• [SCTAB] is the numerical value of SCTAB, expressed in m2/g;
• [WAl] is the numerical value of WAl, expressed in % by weight relative to the weight of the silica S;
• and
• the magnitude A satisfies the relationship (II):
• A≥253 (II);
• thermomechanically kneading the mixture, once or several times, until a maximum temperature of between 110° C. and 190° C. is reached;
• cooling the mixture from the preceding step to a temperature below 100° C.;
• incorporating a crosslinking system into the cooled mixture from the preceding step;
• and
• kneading the mixture comprising the crosslinking system up to a maximum temperature below 110° C.