A synchronous drive belt includes an outer tension section and opposing continuous tooth section defining an outer surface. The synchronous drive belt further includes a cross-linked elastomeric body, and a tensile reinforcement section disposed between the outer tension section and the cross-linked elastomeric body. A fabric reinforcement is disposed inwardly adjacent the outer surface of the continuous tooth section, and the fabric reinforcement is enveloped by the cross-linked elastomeric body. Further, the cross-linked elastomeric body forms the outer surface of the continuous tooth section. In some aspects, the cross-linked elastomeric body contains a urethane material, which may be formed from the reaction product of a polyisocyanate and a hydroxyl functional polyol during a belt molding process. The polyisocyanate and the hydroxyl functional polyol may envelop the fabric reinforcement prior to reacting during the belt molding process, or even while reacting in the molding process.

A rubber-reinforcing cord of the present invention is a rubber-reinforcing cord for reinforcing a rubber product. The rubber-reinforcing cord includes at least one strand. The strand includes at least one filament bundle and a coating provided to cover at least a portion of a surface of the filament bundle. The coating includes a rubber component and a crosslinking agent. The crosslinking agent includes two or more isocyanate compounds.

A drive belt includes a foamed undercord layer having void spaces located throughout the foamed undercord layer. The void spaces extend from a backing layer of the undercord layer to an exterior surface of the backing layer, and may include some void spaces at the exterior surface that are open to the external environment. The foamed undercord layer may exhibit a 20% reduction in specific gravity as compared to an unfoamed version of the undercord layer. The manufacturing process for making the foamed undercord layer can include incorporating foaming agent in the undercord layer such that the undercord layer both foams and cures when heat and pressure are applied to the undercord layer. The foamed drive belt incorporating the foamed undercord layer may exhibit reduced bending stiffness and improved energy efficiency.

A drive belt includes a foamed undercord layer having void spaces located throughout the foamed undercord layer. The void spaces extend from a backing layer of the undercord layer to an exterior surface of the backing layer, and may include some void spaces at the exterior surface that are open to the external environment. The foamed undercord layer may exhibit a 20% reduction in specific gravity as compared to an unfoamed version of the undercord layer. The manufacturing process for making the foamed undercord layer can include incorporating foaming agent in the undercord layer such that the undercord layer both foams and cures when heat and pressure are applied to the undercord layer. The foamed drive belt incorporating the foamed undercord layer may exhibit reduced bending stiffness and improved energy efficiency.

A drive belt includes an undercord layer having a first region proximate a backing layer surface of the undercord layer and a second region proximate the exterior surface of the undercord layer, the first region being foamed and the second region either being foamed to a lesser extent than the first region or not being foamed. The drive belt further includes a cover layer formed over the exterior surface of the undercord layer. Alternatively, the drive belt may be foamed throughout the undercord layer thickness, with a cover layer formed on the exterior surface of the undercord layer. The manufacturing process for making the foamed undercord layer can include incorporating a first quantity of foaming agent in a first sheet of undercord layer material and either a second quantity of foaming agent in a second sheet of undercord layer material, the second quantity being less than the first quantity, or including no foaming agent in the second sheet. The first sheet and second sheet are disposed in a mold, to which heat and pressure is applied to cure the sheets and foam the first sheet and the second sheet when the second sheet includes foaming agent. The mold includes an exterior portion that forms ridges in the exterior surface of the undercord layer and a cover layer disposed on the exterior surface of the undercord layer. The drive belt incorporating the undercord layer having a foamed first region may exhibit reduced bending stiffness and improved energy efficiency.

A drive belt includes an undercord layer having a first region proximate a backing layer surface of the undercord layer and a second region proximate the exterior surface of the undercord layer, the first region being foamed and the second region either being foamed to a lesser extent than the first region or not being foamed. The drive belt further includes a cover layer formed over the exterior surface of the undercord layer. Alternatively, the drive belt may be foamed throughout the undercord layer thickness, with a cover layer formed on the exterior surface of the undercord layer. The manufacturing process for making the foamed undercord layer can include incorporating a first quantity of foaming agent in a first sheet of undercord layer material and either a second quantity of foaming agent in a second sheet of undercord layer material, the second quantity being less than the first quantity, or including no foaming agent in the second sheet. The first sheet and second sheet are disposed in a mold, to which heat and pressure is applied to cure the sheets and foam the first sheet and the second sheet when the second sheet includes foaming agent. The mold includes an exterior portion that forms ridges in the exterior surface of the undercord layer and a cover layer disposed on the exterior surface of the undercord layer. The drive belt incorporating the undercord layer having a foamed first region may exhibit reduced bending stiffness and improved energy efficiency.

The present invention relates to elastomer toothed belts comprising a fabric spanning the teeth of the toothed belt, wherein the elastomer mixture forming the teeth contains a crosslinked ethylene-propylene rubber (EPM) and/or a crosslinked ethylene-propylene terpolymer rubber (EPDM) accounting for at least 70% by weight of the elastomer mixture based on the polymer proportion and wherein an interlayer is arranged between the fabric and the elastomer mixture forming the teeth which contains at least 70% by weight of hydrogenated acrylonitrile-butadiene rubber (HNBR) based on the polymer proportion of the interlayer. Such elastomer toothed belts are halogen-free and feature improved durability and good low-temperature stability properties. The present invention further relates to processes for producing such elastomer toothed belts and to the use of a layer of hydrogenated acrylonitrile-butadiene rubber (HNBR) in such toothed belts to increase service life, to improve low-temperature stability and to improve the adhesion between the teeth and the fabric.

A rubber-reinforcing cord (12) of the present invention includes at least one strand. The strand includes at least one filament bundle and a coating provided to cover at least a portion of the surface of the filament bundle. The coating contains a polymer and cellulose nanofibers, and does not contain a resorcinol-formaldehyde condensate. The polymer contains at least one selected from a polyurethane and a rubber component. In the coating, the content of the cellulose nanofibers is 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer. The proportion of the coating in the rubber-reinforcing cord is 18 vol % or more.

A rubber-reinforcing cord (12) of the present invention includes at least one strand. The strand includes at least one filament bundle and a coating provided to cover at least a portion of the surface of the filament bundle. The coating contains a polymer and cellulose nanofibers, and does not contain a resorcinol-formaldehyde condensate. The polymer contains at least one selected from a polyurethane and a rubber component. In the coating, the content of the cellulose nanofibers is 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer. The proportion of the coating in the rubber-reinforcing cord is 18 vol % or more.

A two-faced, modified interlock knit fabric for use in the manufacture of toothed belts, the fabric constructed by plating a partially oriented first yarn of polyester or nylon with a second yarn of polyester or spun cotton and knit in a blister stitch in the machine direction is provided. A method of forming toothed belts incorporating such a fabric is also provided.