Abstract: A power transmission belt with a body made from a first rubber composition in which at least one load carrying member is embedded. The body has a plurality of laterally spaced ribs with exposed surfaces on the inside of the body. The ribs are made from a second rubber composition in which: a) a plasticizer of 8.3 to 10.7 (cal/cm3)1/2 in solubility parameter; and b) solid lubricant are respectively blended in an amount: i) 5 to 25 pts.wt.; and ii) 5 to 50 pts.wt. per 100 pts.wt. ethylene-?-olefin elastomer. The body further has short fibers fixed at the exposed, pulley engaging rib surfaces.

Abstract: A power transmission belt having a body with an inside, an outside, and laterally oppositely facing side surfaces. The body has at least one surface that engages a pulley to frictionally transmit forces between the power transmission belt and pulley. The body includes rubber defining at least a part of the at least one surface. The rubber is a composition made up of a blend of at least: a) 100 parts by weight of an ethylene/?-olefin elastomer; b) 10 to 25 parts by weight of a plasticizer having a solubility parameter of from 8.3 to 10.7 (cal/cm3)1/2; and c) 60 to 110 parts by weight of an inorganic filler.

Abstract: The present invention provides a friction transmission belt having a friction transmission surface having a rubber composition containing a plasticizer, the plasticizer forming a film on the friction transmission surface, a change in friction coefficient (?) with respect to a change in slipping velocity (V) indicated by a difference between a pulley speed and a belt speed (d?/dv) being 0 or a positive value in a dry state and a wet state.

Abstract: A power transmission belt with a body made from a first rubber composition in which at least one load carrying member is embedded. The body has a plurality of laterally spaced ribs with exposed surfaces on the inside of the body. The ribs are made from a second rubber composition in which: a) a plasticizer of 8.3 to 10.7 (cal/cm3)1/2 in solubility parameter; and b) solid lubricant are respectively blended in an amount: i) 5 to 25 pts.wt.; and ii) 5 to 50 pts.wt. per 100 pts.wt. ethylene-?-olefin elastomer. The body further has short fibers fixed at the exposed, pulley engaging rib surfaces.

Abstract: The present invention provides a friction transmission belt having a friction transmission surface having a rubber composition containing a plasticizer, the plasticizer forming a film on the friction transmission surface, a change in friction coefficient (?) with respect to a change in slipping velocity (V) indicated by a difference between a pulley speed and a belt speed (d?/dv) being 0 or a positive value in a dry state and a wet state.

Abstract: A power transmission belt having a body with an inside, an outside, and laterally oppositely facing side surfaces. The body has at least one surface that engages a pulley to frictionally transmit forces between the power transmission belt and pulley. The body includes rubber defining at least a part of the at least one surface. The rubber is a composition made up of a blend of at least: a) 100 parts by weight of an ethylene/?-olefin elastomer; b) 10 to 25 parts by weight of a plasticizer having a solubility parameter of from 8.3 to 10.7 (cal/cm3)1/2; and c) 60 to 110 parts by weight of an inorganic filler.