# US 10,502,281 B2 · Frictional power transmission belt > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,281 B2 - Document ID: US10502281B2 - Status: Granted - Kind: B2 - Application number: 14/764,759 - Filed: 2014-01-30 - Published: 2015-12-24 - Granted: 2019-12-10 - Earliest claimed: 2013-01-30 - Assignees: Mitsuboshi Belting Ltd. - Applicants: Mitsuboshi Belting Ltd. - Inventors: Hisato Ishiguro; Yorifumi Hineno; Masashi Tamura; Hiroki Imai - Web page: https://patentgrep.com/patent/US10502281B2 ## CPC - F16G 1/08: with reinforcement bonded by the rubber - C08K 7/02: Fibres or whiskers - C08L 7/00: Compositions of natural rubber - C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons - C08L 9/02: Copolymers with acrylonitrile - C08L 9/06: Copolymers with styrene - C08L 11/00: Compositions of homopolymers or copolymers of chloroprene - C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers - C08L 71/02: Polyalkylene oxides - F16G 5/06: with reinforcement bonded by the rubber - F16G 5/20: with a contact surface of special shape, e.g. toothed - C08K 2201/004: Additives being defined by their length - C08K 2201/014: Additives containing two or more different additives of the same subgroup in C08K - F16G: BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract The present invention relates to a frictional power transmission belt containing an extensible layer to form a belt back surface, a compressive layer formed on one surface of the extensible layer and having a power transmission surface at least a part of which can be in contact with pulleys, and a tension member embedded between the extensible layer and the compressive layer along a belt length direction, in which at least the compressive layer is formed of a rubber composition containing a polymer component, short fibers and a surfactant and in which the short fibers contain at least short fibers of water-absorbing fibers. ## Claims ### Claim 1 A frictional power transmission belt comprising: an extensible layer to form a belt back surface, a compressive layer formed on one surface of the extensible layer and having a power transmission surface at least a part of which is configured to contact with pulleys, and a tension member embedded between the extensible layer and the compressive layer along a belt length direction, wherein at least the compressive layer is formed of a rubber composition comprising a polymer component, short fibers and a surfactant, wherein the content of the polymer component in the rubber composition is in a range of 45% to 55% by weight, and the polymer component comprises an ethylene-α-olefin elastomer, wherein the short fibers comprise at least water-absorbing fibers, wherein the short fibers and the surfactant exist to be exposed out to a surface of at least a part of the power transmission surface, and the surfactant adheres to a surface of at least a part of the exposed short fibers, and wherein the mean length of the short fibers is 2 mm to 30 mm. ### Claim 2 (depends on 1) The frictional power transmission belt according to claim 1, wherein the short fibers further comprise reinforcing fibers. ### Claim 3 (depends on 2) The frictional power transmission belt according to claim 2, wherein the water-absorbing fibers comprise cellulosic fibers, the reinforcing fibers comprise at least one type of fibers selected from polyester fibers and polyamide fibers, and the surfactant comprises a nonionic surfactant. ### Claim 4 (depends on 2) The frictional power transmission belt according to claim 2, wherein the short fibers comprise the water-absorbing fibers and the reinforcing fibers in a weight ratio of former/latter of from 10/90 to 50/50. ### Claim 5 (depends on 1) The frictional power transmission belt according to claim 1, wherein the surfactant comprises a polyethylene glycol-type nonionic surfactant having a hydrophile-lipophile-balance (HLB) value of from 8.7 to 17. ### Claim 6 (depends on 1) The frictional power transmission belt according to claim 1, wherein the surfactant is selected from polyoxyethylene C10-26 alkyl ethers, alkylphenol-ethylene oxide adducts and polyalcohol C10-26 fatty acid ester-ethylene oxide adducts, and has a hydrophile-lipophile-balance (HLB) value of from 9 to 15. ### Claim 7 (depends on 1) The frictional power transmission belt according to claim 1, wherein the surfactant has a melting point of 20° C. or lower and a boiling point of 180° C. or higher. ### Claim 8 (depends on 1) The frictional power transmission belt according to claim 1, wherein, relative to 100 parts by weight of the polymer component in the rubber composition, a proportion of the surfactant is from 0.1 to 12 parts by weight and a proportion of the water-absorbing fibers is from 1 to 20 parts by weight. ### Claim 9 (depends on 1) The frictional power transmission belt according to claim 1, wherein a weight ratio of the short fibers of water-absorbing fibers to the surfactant is, as the former/latter, from 15/1 to 0.8/1.