Use of a functionalized organosilicon compound bearing at least one azo function activated, as coupling agent (white filler-elastomer) in rubber compositions comprising an inorganic filler

The field of the invention is the use: -> an effective amount of a coupling agent (A) comprising a functionalized organosilicon compound; -> as coupling agent inorganic filler-elastomer in rubber compositions comprising: (B) at least one rubber-like elastomer of natural or synthetic origin; (C) an inorganic filler as reinforcing filler; (D) all or part of the other constituents or additives normally used including in particular one (or more) agent (s) of vulcanization (D1); -> said use being characterized in that: + the coupling agent (A) is a functionalized organosilicon compound consisting of the species (i) and (2i): (i) being at least one functionalized siloxane oligomer corresponding to the formula (I): [(G ) 3SiO1 / 2] m [(G ) 2SiO2 / 2] n [G SiO3 / 2] o [SiO4 / 2] p [(G ) a (G ) a '(Z-CO-N = N-CO-a) SiO (3-a-a') / 2] q wherein the symbols Z, G , G , G , a, a ', m, n, o, p and q have the meanings given in claim 1; (2i) being a mixture of at least one functionalized siloxane (i) with ( 3i) at least one functionalized organosilane corresponding to formula (I) wherein m = n = o = p = 0 (zero), q = 1, a is an integer selected from 0, 1, 2 and 3 and the sum a + a '= 3; + said coupling agent (a) is incorporated into rubber compositions based on isoprene elastomers.