Organopolysiloxane, rubber compounding agent, rubber composition, and tire

Abstract

Provided are: an organopolysiloxane capable of achieving intended low fuel consumption properties and significantly reducing hysteresis loss in the cured product of a rubber composition during tire production; a rubber compounding agent comprising said organopolysiloxane; a rubber composition obtained by blending said rubber compounding agent; and a tire formed using said rubber composition. The organopolysiloxane, which is represented by average compositional formula (1), is characterized in: containing an organic group with a sulfide group; and the sulfide equivalents being 1,000 g/mol or less. (A)a(B)b(C)c(R1)dSiO(4-2a-b-c-d)/2   (1) (In the formula, A is a sulfide group-containing divalent organic group, B is a C5 to C10 monovalent hydrocarbon group, C is a hydrolyzable group and/or a hydroxyl group, R1 is a C1 to C4 monovalent hydrocarbon group, and for a, b, c and d, 0<2a<1, 0<b<1, 0<c<3, 0≦d<2, and 0<2a+b+c+d<4.)

Dependencies are inferred from the claim text.