# US 11,440,349 B2 · Pneumatic tire and crosslinked rubber composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,349 B2 - Document ID: US11440349B2 - Status: Granted - Kind: B2 - Application number: 15/767,964 - Filed: 2016-10-21 - Published: 2018-10-25 - Granted: 2022-09-13 - Earliest claimed: 2015-10-27 - Assignees: Sumitomo Rubber Industries, Ltd. - Applicants: Sumitomo Rubber Industries, Ltd. - Inventors: Ryo Mashita; Hiroyuki Kishimoto; Ryota Kitago - Web page: https://patentgrep.com/patent/US11440349B2 ## CPC - B60C 1/0008: {Compositions of the inner liner} - B60C 1/00: Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition - B60C 1/0016: {Compositions of the tread} - B60C 11/00: Tyre tread bands; Tread patterns; Anti-skid inserts - B60C 11/0041: {comprising different tread rubber layers} - C08L 9/00: Compositions of homopolymers or copolymers of conjugated diene hydrocarbons - B60C 2001/005: {Compositions of the bead portions, e.g. clinch or chafer rubber or cushion rubber} - B60C 2011/0016: {Physical properties or dimensions} - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract The pneumatic tire of the present invention characterized by comprising: bead cores, a carcass ply, an inner liner and a tread having a volume of the low density region of 35% or more, at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of −20° C. or lower, and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of −20° C. or lower are excellent in abrasion resistance. ## Claims ### Claim 1 A pneumatic tire comprising: bead cores provided on a pair of right and left bead portions, respectively, a carcass ply extending from a crown portion to the both bead portions through both side wall portions and moored to the bead cores, an inner liner disposed at an inner side than the carcass ply in a direction of a tire diameter, and a tread disposed at an outer side than the carcass ply in a direction of a tire diameter and having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of −20° C. or lower, wherein the low density region is a region having a density of 0.1 to 0.8 time the density of a crosslinked rubber composition before the elongation, and wherein the void portion is a region having a density of 0 to 0.1 time the density of a crosslinked rubber composition before the elongation. ### Claim 2 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition comprises silica. ### Claim 3 (depends on 2) The pneumatic tire of claim 2, wherein a content of the silica is 5 to 200 phr. ### Claim 4 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition comprises a rubber component comprising styrene-butadiene rubber. ### Claim 5 (depends on 4) The pneumatic tire of claim 4, wherein a styrene content of the styrene-butadiene rubber is 16% to 60% by mass and a vinyl content of the styrene-butadiene rubber is 10% to 90%. ### Claim 6 (depends on 4) The pneumatic tire of claim 4, wherein a Tg of the styrene-butadiene rubber is from −54° C. to 10° C. ### Claim 7 (depends on 4) The pneumatic tire of claim 4, wherein a weight-average molecular weight of the styrene-butadiene rubber is from 400,000 to 2,000,000. ### Claim 8 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition comprises an oil. ### Claim 9 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition comprises a silane coupling agent. ### Claim 10 (depends on 9) The pneumatic tire of claim 9, wherein the crosslinked rubber composition further comprises silica, wherein a content of the silane coupling agent is 2 to 25 parts by mass based on 100 parts by mass of the silica. ### Claim 11 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition comprises a rubber component comprising two kinds of styrene-butadiene rubber, and butadiene rubber. ### Claim 12 (depends on 11) The pneumatic tire of claim 11, wherein a content of the styrene-butadiene rubber in the rubber component is 30% by mass to 90% by mass. ### Claim 13 (depends on 11) The pneumatic tire of claim 11, wherein a content of the butadiene rubber in the rubber component is 10% by mass to 70% by mass. ### Claim 14 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition comprises emulsion-polymerized styrene-butadiene rubber and solution-polymerized styrene-butadiene rubber, wherein a content of the emulsion-polymerized styrene-butadiene rubber is 15 parts by mass to 29 parts by mass, and wherein a content of the solution-polymerized styrene-butadiene rubber is 34 parts by mass to 58 parts by mass. ### Claim 15 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition further comprises carbon black. ### Claim 16 (depends on 15) The pneumatic tire of claim 15, wherein a content of the carbon black is 3 to 200 phr based on 100 parts by mass of the rubber component. ### Claim 17 (depends on 1) The pneumatic tire of claim 1, wherein the crosslinked rubber composition further comprises: styrene-butadiene rubber in the rubber component having a content of 30% by mass to 90% by mass; butadiene rubber in the rubber component having a content of 10% by mass to 70% by mass, wherein a styrene content of the styrene-butadiene rubber in the rubber component is 16% to 60% by mass and a vinyl content of the styrene-butadiene rubber is 10% to 90%; carbon black having a content of 3 to 200 phr based on 100 parts by mass of the rubber component; silica having a content of 5 to 200 phr; silane coupling agent. ### Claim 18 (depends on 17) The pneumatic tire of claim 17, wherein a content of silane coupling agent is 2 to 25 parts by mass based on 100 parts by mass of the silica. ### Claim 19 (depends on 18) The pneumatic tire of claim 18, wherein the rubber component, a first portion of a sulfur donator and a first portion of a vulcanization accelerator are kneaded in a first step to form a first product; wherein the first product and at least the silica, silane coupling agent, a second portion of the sulfur donator and a second portion of the vulcanization accelerator are kneaded in a second step to form a second product; and wherein the second product and sulfur are added in a third step to form the crosslinked rubber composition. ### Claim 20 A crosslinked rubber composition having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of −20° C. or lower, wherein the low density region is a region having a density of 0.1 to 0.8 time the density of a crosslinked rubber composition before the elongation, wherein the void portion is a region having a density of 0 to 0.1 time the density of a crosslinked rubber composition before the elongation. ### Claim 21 (depends on 20) The crosslinked rubber composition of claim 20, wherein the volume of the low density region at elongation by an applied stress of 1.5 MPa is 40% or more, and wherein the volume of the void portion at elongation by an applied stress of 3.0 MPa is 7.3% or less. ### Claim 22 (depends on 20) The crosslinked rubber composition of claim 20, wherein the volume of the low density region at elongation by an applied stress of 1.5 MPa is 50% or more, and wherein the volume of the void portion at elongation by an applied stress of 3.0 MPa is 7.0% or less. ### Claim 23 (depends on 20) The crosslinked rubber composition of claim 20, wherein the volume of the low density region at elongation by an applied stress of 1.5 MPa is 60% or more, and wherein the volume of the void portion at elongation by an applied stress of 3.0 MPa is 6.7% or less. ### Claim 24 (depends on 20) The crosslinked rubber composition of claim 20, wherein the volume of the low density region at elongation by an applied stress of 1.5 MPa is 70% or more, and wherein the volume of the void portion at elongation by an applied stress of 3.0 MPa is 6.3% or less. ### Claim 25 (depends on 24) The crosslinked rubber composition of claim 24, wherein the volume of the low density region at elongation by an applied stress of 1.5 MPa is 72% or more, and wherein the volume of the void portion at elongation by an applied stress of 3.0 MPa is 6.2% or less. ### Claim 26 (depends on 24) The crosslinked rubber composition of claim 24, wherein the glass transition temperature is −22° C. or lower. ### Claim 27 (depends on 20) The crosslinked rubber composition of claim 20, wherein the glass transition temperature is −24° C. or lower. ### Claim 28 (depends on 20) The crosslinked rubber composition of claim 20, wherein the glass transition temperature is −25° C. or lower. ### Claim 29 (depends on 20) The crosslinked rubber composition of claim 20, wherein the glass transition temperature is −28° C. or lower. ### Claim 30 (depends on 20) The crosslinked rubber composition of claim 20, comprising a rubber component comprising a conjugated diene compound. ### Claim 31 (depends on 20) The crosslinked rubber composition of claim 20, wherein the volume of the low density region at elongation by an applied stress of 1.5 MPa is evaluated from a density distribution of the crosslinked rubber composition when extended using an X-ray computerized tomography, and wherein the volume of the void portion at elongation by an applied stress of 3.0 MPa is evaluated from a density distribution of the crosslinked rubber composition when extended using an X-ray computerized tomography. ### Claim 32 (depends on 31) The crosslinked rubber composition of claim 31, wherein the density distribution of the crosslinked rubber composition when extended using an X-ray computerized tomography is evaluated with an evaluation device comprising a photographing means, the photographing means has an X-ray tube for irradiating an X-ray and a detector for detecting the X-ray and converting it into an electric signal, the detector has a phosphor for converting the X-ray into a visible light, and a decay time of the phosphor is 100 ms or less. ### Claim 33 (depends on 32) The crosslinked rubber composition of claim 32, wherein a luminance of the X-ray irradiated from the X-ray tube is 1010 photons/s/mrad2/mm2/0.1% bw or more. ### Claim 34 (depends on 21) A pneumatic tire comprising: bead cores provided on a pair of right and left bead portions, respectively, a carcass ply extending from a crown portion to the both bead portions through both side wall portions and moored to the bead cores, an inner liner disposed at an inner side than the carcass ply in a direction of a tire diameter, and a tread disposed at an outer side than the carcass ply in a direction of a tire diameter and composed of the crosslinked rubber composition of claim 21.