Patent ID: 8268921

Claim:
An elastomeric composition (C1) containing at least one butadienic elastomer E, which contains precipitated silica S1 as at least one reinforcing filler and at least one coupling agent, wherein: the butadienic elastomer E comprises a functionalized butadienic elastomer prepared in solution, which is modified by at least one polyfunctional coupling agent having an alkoxy silane group; and said precipitated silica S1 is prepared by a process including a precipitation reaction of a silicate with an acidifying agent, whereby a suspension of precipitated silica is obtained, and then the separation and the drying of this suspension, wherein: the precipitation reaction is carried out in the following manner: (i.1) an initial base stock comprising a silicate and an electrolyte is formed, the silicate concentration (expressed as SiO 2 ) in said initial base stock being lower than 100 g/l, and the electrolyte concentration in said initial base stock being lower than 17 g/l; (ii.1) acidifying agent is added to said base stock until a pH value of the reaction mixture of at least approximately 7 is obtained, (iii.1) acidifying agent and a silicate are added simultaneously to the reaction mixture, a suspension which has a solids content of not more than 24% by weight is dried, and said process further including one of the following steps (a1) or (b1): (a1) after stage (iii.1), at least one aluminum compound A and then a basic agent are added to the reaction mixture, and said separation comprises a filtration and disintegration of the cake originating from this filtration, said disintegration being performed in the presence of at least one aluminum compound B, (b1) after stage (iii.1) a silicate and at least one aluminum compound A are added simultaneously to the reaction mixture and, when said separation comprises a filtration and disintegration of the cake originating from this filtration, the disintegration is optionally performed in the presence of at least one aluminum compound B, and wherein the composition comprises coupling agent in an amount such that the weight ratio of coupling agent to silica is at most 4%.