A power transmission belt is at least partially formed of a rubber composition. The rubber composition contains a rubber component, cellulose nanofibers, and carbon black. The amount of the cellulose nanofibers to be added is from 0.1 parts by mass to 20 parts by mass, relative to 100 parts by mass of the rubber component. The amount of the carbon black to be added is from 5 parts by mass to 80 parts by mass, relative to 100 parts by mass of the rubber component. The sum of the amount of the carbon black to be added and three times the amount of the cellulose nanofibers to be added is from 15 to 90.

A production method of a V-belt uses a belt mold having a plurality of compression layer-shape grooves arranged adjacent to one another in a groove width direction. A shaped structure having a plurality of ridges on an outer peripheral surface is crosslinked and combined with a fabric material to form a belt slab, while the compression layer-forming portions, which are the ridges covered with the fabric material, being fitted in the respective compression layer-shape grooves of the belt mold. The belt slab is cut into ring-shaped pieces such that one ring-shaped piece corresponds to one compression layer-forming portion.

A production method of a raw edge V-belt uses a belt mold having a plurality of compressed rubber layer-shape grooves arranged adjacent to one another. A shaped structure having a plurality of compressed rubber layer-forming portions on an outer peripheral surface is crosslinked to form a belt slab, while the compressed rubber layer-forming portions fitted in the respective compressed rubber layer-shape grooves of the belt mold. The belt slab is cut into ring-shaped pieces such that one ring-shaped piece corresponds to one compressed rubber layer-forming portion.

Provided is a method for producing a V-ribbed belt having a plurality of V-shaped ribs extending in a longitudinal direction and arranged in a width direction. The method includes: setting a shaped structure having a plurality of ridges arranged adjacent to one another in a belt mold including a plurality of compressed rubber layer-shaping grooves arranged adjacent to one another on an inner peripheral surface of the mold; molding a belt slab by crosslinking the shaped structure set in the mold, while compressed rubber layer-forming portions face radially outward and are fitted in the compressed rubber layer-shaping grooves, the compressed rubber layer-forming portions comprised of a surface rubber layer and a core rubber layer which are to constitute surface and inner portions, respectively; and cutting the belt slab into ring-shaped pieces having two or more of the compressed rubber layer-forming portions.

A shaped structure and a fabric material are set in a belt mold such that the shaped structure and the fabric material are respectively positioned inside and outside with respect to each other. While each of compression layer-forming portions comprised of ridges of the shaped structure covered with the fabric material is fitted in an associated one of compression layer-shaping grooves of the belt mold, the shaped structure is pressed toward the belt mold and heated to be crosslinked, and integrated with the fabric material, thereby molding a cylindrical belt slab. The belt slab is cut into ring-shaped pieces having two or more of the compression layer-forming portions.

The present invention relates to a power-transmitting friction belt having a compressed layer and a knitted fabric. The surface of the compressed layer is covered with the knitted fabric. The knitted fabric has an overlapping section in which one end and the other end of the knitted fabric overlap each other. The overlapping section has a bonding region containing a bonding component for bonding the end and the other end of the knitted fabric together.

A production method for producing a frictional power transmission belt containing an extensible layer forming a belt back surface, a compressive rubber layer formed on one surface of the extensible layer and frictionally engaging at the lateral surface thereof with pulleys, and a tension member embedded between the extensible layer and the compressive rubber layer along the belt length direction. A surface of at least a part of the compressive rubber layer to be in contact with pulleys is coated with a fiber/resin mixture layer that contains a resin component and heat-resistant fibers having a softening point or a melting point higher than a vulcanization temperature in a mixed state, and the heat-resistant fibers contain a fiber embedded so as to extend from the fiber/resin mixture layer to the compressive rubber layer.

A method for treating a tension member in the production of a belt. The belt includes at least a belt body made of a polymer material having elastic properties, a cover layer as a belt backing, and a substructure having a force-transmission zone. The tension member has a ribbed design and is embedded in the belt body. The tension member is treated with an overall treatment mixture which forms a cross-linked polymer that on the one hand enters into a mechanical connection with the tension member and on the other hand forms an adhesive connection with the belt body.

The present invention relates to a power transmission belt containing a frictional power transmission part and a fiber member that covers a surface of the frictional power transmission part, in which the fiber member is formed of a fiber (A) containing a water-absorbent fiber (A1) and contains a surfactant, to a fiber member used in the power transmission belt, and to a method for manufacturing the fiber member.

A method include: providing a cylindrical mold made of metal, a shaped structure having a cylindrical shape, a rotation mechanism configured to rotatably support the cylindrical mold, and an electromagnetic induction coil configured to heat the cylindrical mold through electromagnetic induction; setting the shaped structure inside the cylindrical mold; and molding a cylindrical belt slab by heating the cylindrical mold by the electromagnetic induction coil, while the cylindrical mold is rotated by the rotation mechanism and the shaped structure is pressurized from inside and pressed against the cylindrical mold.