Patent ID: 7256233

Claim:
A rubber composition comprising at least one diene elastomer, one reinforcing inorganic filler, and a coupling agent providing a bond between the inorganic filler and the elastomer, wherein the inorganic filler comprises a synthetic aluminosilicate of the formula: M x SiAl y O a (OH) b , (H 2 O) c (I) where: M is a cation selected from the group consisting of K + , Na + , Ca ++ and mixtures of these cations; x>0; y>0; a≧0; b≧0, c≧0 and a+b>0; and having the following characteristics: (a) a BET specific surface area of between 20 and 300 m 2 /g; (b) an average particle size by mass (d w ) of between 20 and 400 nm; (c) an ultrasound disagglomeration rate (α) greater than 5×10 −4 μm −1 /min.