Abstract: A rubber composition includes: a rubber component; a filler in an amount of 40 to 125 parts by mass per 100 parts by mass of the rubber component; and a hydrogenated resin in an amount of 5 to 50 parts by mass per 100 parts by mass of the rubber component, the resin having a softening point of higher than 110° C. and a weight average molecular weight, as determined in terms of polystyrene, of 200 to 1200 g/mol. The rubber composition can be used to produce a tire having an excellent wet grip performance and a low rolling resistance, and a vulcanized rubber having excellent handling properties.

Abstract: The antivibration rubber composition of the present invention contains a styrene-butadiene rubber (A) having a polystyrene-equivalent weight-average molecular weight of 700,000 or more, and a liquid styrene-butadiene rubber (B) having a polystyrene-equivalent weight-average molecular weight of 12,000 or less, wherein the total amount of the vinyl bond content in the rubber (A) and the vinyl bond content in the liquid rubber (B) relative to the total amount of the rubber (A) and the liquid rubber (B) is 25% by mass or more. The antivibration rubber using the composition exhibits ultra-low spring property and high durability.