Patent ID: 8337349

Claim:
A power transmission belt comprising: (a) rubber layers comprising a compression rubber layer and an adhesion rubber layer, both of which are vulcanized and bonded to each other; (b) a plurality of load carrying cords embedded in the adhesion rubber layer; (c) short fibers dispersed in the compression rubber layer and oriented in the widthwise direction of the belt; and (d) a plurality of ribs formed integrally with the compression rubber layer and extending in the lengthwise direction of the belt, (i) wherein at least the compression rubber layer of the rubber layers comprises vulcanizate obtained by vulcanizing an ethylene-α-olefin-diene rubber with an organic peroxide in an amount of 0.005-0.05 moles in relation to 100 g of the ethylene-α-olefin-diene rubber and at least one trifunctional co-crosslinking agent selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate and triallyl isocyanurate in an amount of 0.1-10 parts by weight in relation to 100 parts by weight of the ethylene-α-olefin-diene rubber, and (ii) wherein the compression rubber layer has the short fibers comprising first short fibers without adhesion treatment and second short fibers with adhesion treatment in an amount of 5-30 parts by weight in total in relation to 100 parts by weight of the ethylene-α-olefin-diene rubber, the second short fibers being in the amount of 5-25% by weight based on the total amount of the first and second short fibers.