| abstract |
An additive for rubber containing a sulfide composition, wherein the sulfide composition contains a sulfide compound having a repeating unit represented by the formula (1), and the amount of the repeating unit (1) in the sulfide compound is 100 mol parts. In contrast, the additive for rubber is provided wherein the amount of the repeating unit (1) where X = 2 is 45 mol parts or more, and the number n of the repeating units (1) in the sulfide compound is 1 to 400. By this, the rubber additive which can provide the outstanding heat resistance, and the rubber composition containing this rubber additive are provided. |