The frictional power transmission belt includes a frictional power transmission surface formed of a composite fibrous layer containing a fibrous member, an isocyanate compound, and a resin component, wherein the fibrous member contains a cellulose-based fiber. A proportion of each of the isocyanate compound and the resin component in the composite fibrous layer may be 2 to 15% by mass.

A belt with a tensile cord embedded in an elastomeric body, having a polyurea-urethane adhesive composition impregnating the cord and coating the fibers. The composition is reaction product of a polyurethane prepolymer and a diamine curative. The prepolymer is a reaction product of a compact, symmetric diisocyanate and a polyester, polyether, or polycarbonate polyol. The belt body may be of cast polyurethane, vulcanized rubber, or thermoplastic elastomer. The cord may have an adhesive overcoat.

A belt with a tensile cord embedded in an elastomeric body, having a polyurea-urethane adhesive composition impregnating the cord and coating the fibers. The composition is reaction product of a polyurethane prepolymer and a diamine curative. The prepolymer is a reaction product of a compact, symmetric diisocyanate and a polyester, polyether, or polycarbonate polyol. The belt body may be of cast polyurethane, vulcanized rubber, or thermoplastic elastomer. The cord may have an adhesive overcoat.

The present invention relates to a method for manufacturing a cord for a power transmission belt, including a first treatment step of treating an untreated yarn of a cord for a power transmission belt with a first treatment agent containing: a rubber composition (A) containing a condensate (A1) of a resorcin and formaldehyde, a rubber component (A2) containing a carboxy-modified latex, and a curing agent (A3) containing a polycarbodiimide resin having a plurality of carbodiimide groups; and a hydrophilic solvent (B).

The present invention relates to a method for manufacturing a cord for a power transmission belt, including a first treatment step of treating an untreated yarn of a cord for a power transmission belt with a first treatment agent containing: a rubber composition (A) containing a condensate (A1) of a resorcin and formaldehyde, a rubber component (A2) containing a carboxy-modified latex, and a curing agent (A3) containing a polycarbodiimide resin having a plurality of carbodiimide groups; and a hydrophilic solvent (B).

A method for producing a sheet-like composite fabric material, in particular a rubberized fabric or a fabric provided with a polymer preparation, for covering drive belts, the composite fabric material comprising a textile integrated in a matrix of elastomeric material, preferably at least one fabric layer integrated in a rubber matrix, the textile or the fabric layer and the elastomeric material being introduced into a gap between a band and a cylindrical molding wheel and molded to form a composite material between the band and the molding wheel at a temperature below the vulcanization temperature, the band looping around the molding wheel at a looping angle under pressure. Likewise disclosed is a drive belt with a covering of composite material produced according to the invention.

A toothed power transmission belt with a smooth back side surface has a back jacket on the back side surface; wherein the back jacket comprises a closed-mesh, knit fabric tube. The fabric tube may be knitted on a circular weft knitting machine and may be heat set after knitting. The fabric tube may be treated with an epoxy, RFL or other treatment to provide for oil resistance, adhesion, frictional properties, etc.

A toothed power transmission belt with a smooth back side surface has a back jacket on the back side surface; wherein the back jacket comprises a closed-mesh, knit fabric tube. The fabric tube may be knitted on a circular weft knitting machine and may be heat set after knitting. The fabric tube may be treated with an epoxy, RFL or other treatment to provide for oil resistance, adhesion, frictional properties, etc.

A V-ribbed belt includes a plurality of V-rib portions extending along a longitudinal direction of the belt and in parallel with one another, and a compression rubber layer including a frictional power transmission face at least a part of which can come into contact with a V-rib groove portion of a pulley. The frictional power transmission face of the compression rubber layer is formed from a vulcanizate of a rubber composition containing a rubber component and a noise suppression improver. A difference (Rp−Rb) between a curvature radius Rp of a rib top end of the pulley and a curvature radius Rb of a rib bottom portion of the V-ribbed belt is −0.08 to 0.08 mm.

A V-ribbed belt includes a plurality of V-rib portions extending along a longitudinal direction of the belt and in parallel with one another, and a compression rubber layer including a frictional power transmission face at least a part of which can come into contact with a V-rib groove portion of a pulley. The frictional power transmission face of the compression rubber layer is formed from a vulcanizate of a rubber composition containing a rubber component and a noise suppression improver. A difference (Rp−Rb) between a curvature radius Rp of a rib top end of the pulley and a curvature radius Rb of a rib bottom portion of the V-ribbed belt is −0.08 to 0.08 mm.