# US 2014/0194545 A1 · Vehicle tyre having a tread comprising a heat-expandable rubber composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0194545 A1 - Document ID: US20140194545A1 - Status: Published application - Kind: A1 - Application number: 14/122,409 - Filed: 2012-05-31 - Published: 2014-07-10 - Earliest claimed: 2011-06-01 - Assignees: Michelin Recherche et Technique S.A.; Compagnie Generale Des Etablissements Michelin - Inventors: Masayuki Maesaka; Salvatore Pagano - Web page: https://patentgrep.com/patent/US20140194545A1 ## CPC - C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons - B60C 1/0016: {Compositions of the tread} - C08K 3/04: Carbon - C08K 3/26: Carbonates; Bicarbonates - C08K 3/36: Silica - C08K 5/09: Carboxylic acids; Metal salts thereof; Anhydrides thereof - C08L 7/00: Compositions of natural rubber - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract A vehicle tyre, usable in winter weather, includes a tread formed of a rubber composition that is heat-expandable when in an unvulcanized state, and expanded when in a vulcanized state. When unvulcanized, the composition includes a diene elastomer, such as natural rubber and/or a polybutadiene; more than 50 phr of a reinforcing filler, such as silica and/or carbon black; between 5 and 25 phr of a sodium- or potassium-including carbonate or hydrogen carbonate; and between 2 and 20 phr of a carboxylic acid having a melting point between 60° C. and 220° C., such as citric acid or stearic acid. A total content of the carboxylic acid and the carbonate or the hydrogen carbonate is greater than 10 phr. Presence of the carboxylic acid and the carbonate or the hydrogen carbonate makes it possible to greatly improve the tyre's grip on melting ice. ## Claims ### Claim at position 1 1-22. (canceled) ### Claim 23 A tyre comprising a tread, wherein the tread, in an unvulcanized state, includes a heat-expandable rubber composition, wherein the rubber composition includes: a diene elastomer; more than 50 phr of a reinforcing filler; between 5 and 25 phr of a carbonate or a hydrogen carbonate, wherein the carbonate or the hydrogen carbonate includes sodium or potassium; and between 2 and 20 phr of a carboxylic acid having a melting point between 60° C. and 220° C., and wherein a total content of the carboxylic acid and the carbonate or the hydrogen carbonate is greater than 10 phr. ### Claim 24 (depends on 23) The tyre according to claim 23, wherein the diene elastomer is selected from a group of elastomers consisting of: natural rubber, synthetic polyisoprenes, polybutadienes, butadiene copolymers, isoprene copolymers, and mixtures thereof. ### Claim 25 (depends on 24) The tyre according to claim 24, wherein the rubber composition includes 50 to 100 phr of a natural rubber or a synthetic polyisoprene. ### Claim 26 (depends on 25) The tyre according to claim 25, wherein the natural rubber or the synthetic polyisoprene is used as a blend with at most 50 phr of a polybutadiene having a content of cis-1,4-bonds of greater than 90%. ### Claim 27 (depends on 24) The tyre according to claim 24, wherein the rubber composition includes 50 to 100 phr of a polybutadiene having a content of cis-1,4-bonds of greater than 90%. ### Claim 28 (depends on 27) The tyre according to claim 27, wherein the polybutadiene is used as a blend with at most 50 phr of a natural rubber or a synthetic polyisoprene. ### Claim 29 (depends on 23) The tyre according to claim 23, wherein the reinforcing filler includes an inorganic filler, carbon black, or a mixture of an inorganic filler and carbon black. ### Claim 30 (depends on 23) The tyre according to claim 23, wherein the reinforcing filler is present at a content of between 50 and 150 phr. ### Claim 31 (depends on 23) The tyre according to claim 23, wherein the rubber composition includes a plasticizing agent that is a liquid at 20° C., the plasticizing agent being present at a content such that a weight ratio of the reinforcing filler to the liquid plasticizing agent is greater than 2.0. ### Claim 32 (depends on 23) The tyre according to claim 23, wherein the carbonate or the hydrogen carbonate is present at a content of between 8 and 20 phr. ### Claim 33 (depends on 23) The tyre according to claim 23, wherein the carboxylic acid is present at a content of between 2 and 15 phr. ### Claim 34 (depends on 23) The tyre according to claim 23, wherein the total content of the carboxylic acid and the carbonate or the hydrogen carbonate is greater than 15 phr. ### Claim 35 (depends on 23) The tyre according to claim 23, wherein the melting point of the carboxylic acid is between 100° C. and 200° C. ### Claim 36 (depends on 23) The tyre according to claim 23, wherein a pKa of the carboxylic acid is greater than 1. ### Claim 37 (depends on 23) The tyre according to claim 23, wherein the carboxylic acid includes, along a hydrocarbon chain thereof, from 2 to 22 carbon atoms. ### Claim 38 (depends on 37) The tyre according to claim 37, wherein the carboxylic acid is selected from a group of acids consisting of: palmitic acid, stearic acid, nonadecanoic acid, behenic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, benzoic acid, tartaric acid, malic acid, maleic acid, glycolic acid, α-ketoglutaric acid, salicylic acid, phthalic acid, citric acid, and mixtures thereof. ### Claim 39 (depends on 38) The tyre according to claim 38, wherein the carboxylic acid is selected from a group of acids consisting of: malic acid, α-ketoglutaric acid, citric acid, stearic acid, and mixtures thereof. ### Claim 40 (depends on 23) The tyre according to claim 23, wherein the rubber composition includes a vulcanization retarder. ### Claim 41 (depends on 23) The tyre according to claim 23, wherein a density of the rubber composition, when in the unvulcanized state, is between 1.100 and 1.400 g/cm3. ### Claim 42 (depends on 23) The tyre according to claim 23, wherein the tyre is cured to a vulcanized state in which the rubber composition is expanded. ### Claim 43 (depends on 42) The tyre according to claim 42, wherein a density of the rubber composition, when expanded, is between 0.700 and 1.000 g/cm3. ### Claim 44 (depends on 42) The tyre according to claim 42, wherein a degree of expansion by volume of the rubber composition, when expanded, is between 20% and 75%.