Rubber composition for tire comprising an organosiloxane coupling agent

A tire comprising a rubber composition based on at least one isoprene elastomer, an inorganic filler as reinforcing filler and a polyfunctional organosiloxane coupling agent which provides the bonding between the said reinforcing inorganic filler and the isoprene elastomer, wherein the organosiloxane corresponds to the formula (VII):

• [(G0)3SiO1/2]m[(G0)2SiO2/2]n[G0SiO3/2]o[SiO4/2]p[(G2)b′(G1)a′(A-CO—N═N—CO—Z)SiO(3-a′-b′)/2]q
• in which:
• Z is a divalent bonding group connecting the azodicarbonyl functional group to a silicon atom of the organosiloxane;
• A represents (i) a monovalent radical which can be unsubstituted or substituted hydrocarbon or a monovalent residue selected from the group consisting of —OR′, —NR′, and —SR′, wherein R′ is a monovalent hydrocarbon radical, or (ii) the group of formula Z′ in which Z′, which is identical to or different from Z, and is a divalent bonding group which makes it possible to connect the azodicarbonyl functional group to a silicon atom (identical to or different from the Si atom connected to Z) of the organosiloxane;
• A, Z and if applicable Z′, independently, may comprise one or more heteroatoms;
• a′ represents an integer chosen from 0, 1 and 2;
• b′ represents an integer chosen from 0, 1 and 2;
• the sum a′+b′ is equal to 1 or 2 with the condition according to which, when b′=0, then at least one of the G0 symbols corresponds to the definition of G2;
• m lies within the range from 1 to 2;
• n=o=p=0 (zero) and q=1;
• the G0 symbols, which are identical or different, each represent one of the groups corresponding to G2 or G1
• the G1 radicals, which are identical or different if several are present, represent a monovalent hydrocarbon radical;
• the G2 radicals, which are identical or different if several are present, represent a hydroxyl or hydrolysable group.