The present invention relates to a method of producing a cord for a power transmission belt, the method including: a first treatment step of treating an untreated yarn of a cord for a power transmission belt with a first treatment agent including a resin component (A) to obtain a first treated yarn; and a second treatment step of treating the first treated yarn with a second treatment agent including a condensate (B1) of resorcin and formaldehyde, an unmodified latex (B2), and an acid-modified diene-based polymer (B3) to obtain a second treated yarn.

The present invention relates to a V-ribbed belt including: a tension rubber layer made of a vulcanizate of a rubber composition including a rubber component and short fibers; and a core wire, in which a proportion of the short fibers in the rubber composition is 15-50 parts by mass with respect to 100 parts by mass of the rubber component, and the rubber composition has a minimum Mooney scorch viscosity measured at 125° C. of 70-130.

The present invention relates to a V-ribbed belt including: a tension rubber layer made of a vulcanizate of a rubber composition including a rubber component and short fibers; and a core wire, in which a proportion of the short fibers in the rubber composition is 15-50 parts by mass with respect to 100 parts by mass of the rubber component, and the rubber composition has a minimum Mooney scorch viscosity measured at 125° C. of 70-130.

A process for the production of a traction or carrying means built up from a plurality of components or assemblies of extruded elastomeric material, wherein, in a first substep, a first component, provided with reinforcing members or cables, of the traction or carrying means is produced and, in further substeps, a traction or carrying means, which is connected to further components or provided with further layers of elastomeric material, fabric layers or reinforcing-member layers, is successively completed, and optionally said traction or carrying means is shaped on one or more sides, wherein the individual substeps follow one another such that a component processed or completed in the respectively preceding substep is fed at room temperature (Rt), after a maximum of 1 to 10 minutes, to the subsequent substep, and such that the temperature of the component does not drop below 30° C. between a respectively preceding substep and the subsequent substep.

A high efficiency belt having reduced bending stiffness while maintaining a high coefficient of friction. The belt includes a backing layer, a rib material layer, and cords embedded within, wherein the coefficient of friction of the high efficiency belt is greater than or equal to 0.03 mm/N times the bending stiffness for belts having a thickness in the range of from 2.6 mm to 4.2 mm. The belt can include a bending stiffness in the range of from about 30 N/mm to about 65 N/mm and an anisotropic modulus of elasticity ratio of between 1.1 and 5.0. Methods of manufacturing the high efficiency belt are also described and can include forming sheets of rib material with parallel aligned reinforcement fibers transverse to the direction of rotation of the high efficiency belt.

A frictional power transmission belt includes a compression rubber layer having a frictional power transmission surface that is covered with a fabric. The compression rubber layer includes an inner rubber layer in contact with the fabric and an outer rubber layer on an outer peripheral side of the inner rubber layer. The inner rubber layer is formed of a cured product of a rubber composition including a surfactant as a hydrophilic plasticizer, an unsaturated carboxylic acid metal salt, and polyolefin particles.

The present invention relates to a V-ribbed belt that has a medium elongation of 0.8% or more when the load of 4 cN/dtex is applied, and that contains a twisted cord in which a high-elongation aramid fiber having a tensile modulus of 50-100 GPa and a low-modulus fiber having a lower tensile modulus than the high-elongation aramid fiber are blended and twisted.

The present invention relates to a V-ribbed belt that has a medium elongation of 0.8% or more when the load of 4 cN/dtex is applied, and that contains a twisted cord in which a high-elongation aramid fiber having a tensile modulus of 50-100 GPa and a low-modulus fiber having a lower tensile modulus than the high-elongation aramid fiber are blended and twisted.

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.

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.