Diene rubber composition for tire including a silica as a reinforcing filler

摘要

A diene rubber composition for tires based on at least (i) one diene elastomer, (ii) one reinforcing inorganic filler and (iii) one coupling agent which provides the bonding between the inorganic filler and the elastomer. The inorganic filler comprises at least one silica capable of being obtained by the preparation process of the type comprising the reaction of a silicate with an acidifying agent, whereby a silica suspension is obtained, followed by the separation and the drying of this suspension. The reaction of the silicate with the acidifying agent is carried out according to the following successive stages: (i) an aqueous suspension of precipitated silica, exhibiting a pH of between 2.5 and 5.3, is brought into contact (mixing) with acidifying agent and silicate, in such a way that the pH of the reaction medium is maintained between 2.5 and 5.3, (ii) silicate is added to the reaction medium obtained, so as to increase the pH of the reaction medium up to a value of between 4.7 and 6.3.

主权项

1. A diene rubber composition for tires based on at least (i) one diene elastomer, (ii) one reinforcing inorganic filler and (iii) one coupling agent which provides the bonding between the reinforcing filler and the elastomer, wherein the inorganic filler comprises at least one silica formed of aggregates of primary particles (A) of silica, at the surface of which occur primary particles (B) of silica with a size smaller than that of the primary particles (A), and wherein the at least one silica has:
a CTAB specific surface (SCTAB) and a BET specific surface Area (SBET) such that SCTAB/SBET ratio is between 1.1 and 1.4, wherein the SCTAB is between 60 and 400 m2/g, a d50 median size of aggregates, measured by XDC particle sizing after ultrasonic deagglomeration, such that:
d50 (nm)>(6214/SCTAB (m2/g))+23, a pore volume distribution such that:
V(d5-d50)/V(d5-d100)>0.906−(0.0013×SCTAB (m2/g)), a pore size distribution such that:
Mode (nm)>(4166/SCTAB (m2/g))−9.2, and the silica exhibits a parameter C, measured by small angle X-ray scattering, such that: C/SCTAB (m2/g)>0.001.