Patent ID: 7189785

Claim:
A rubber composition for a heavy duty power transmission belt, the rubber composition having a rubber hardness of 40 to 60 when measured with a durometer Type D, a value of t 5 of −50° C. to −35° C. when given by a Gehman torsion test, and an amount of acetone extract of 9% or less, wherein: (a) 20 to 40 parts by weight of a metal salt monomer of an organic acid is mixed into 100 parts by weight of a rubber component composed of an ethylene-α-olefin elastomer and hydrogenated acrylonitrile butadiene rubber; (b) 5 to 35 parts by weight of short fibers are mixed into 100 parts by weight of the rubber component; and (c) the amount of the ethylene-α-olefin elastomer in 100 parts by weight of the rubber component is 55 to 75 parts by weight.