WO2025084239A1 - 空気入りタイヤ及びその製造方法 - Google Patents

空気入りタイヤ及びその製造方法 Download PDF

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Publication number
WO2025084239A1
WO2025084239A1 PCT/JP2024/036475 JP2024036475W WO2025084239A1 WO 2025084239 A1 WO2025084239 A1 WO 2025084239A1 JP 2024036475 W JP2024036475 W JP 2024036475W WO 2025084239 A1 WO2025084239 A1 WO 2025084239A1
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WO
WIPO (PCT)
Prior art keywords
tire
layer
sealant
pneumatic tire
belt
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/JP2024/036475
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English (en)
French (fr)
Japanese (ja)
Inventor
清人 高橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yokohama Rubber Co Ltd
Original Assignee
Yokohama Rubber Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yokohama Rubber Co Ltd filed Critical Yokohama Rubber Co Ltd
Priority to JP2025553165A priority Critical patent/JPWO2025084239A1/ja
Priority to CN202480063054.4A priority patent/CN121969509A/zh
Publication of WO2025084239A1 publication Critical patent/WO2025084239A1/ja
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C19/00—Tyre parts or constructions not otherwise provided for
    • B60C19/12—Puncture preventing arrangements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C5/00—Inflatable pneumatic tyres or inner tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
    • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
    • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/12—Materials for stopping leaks, e.g. in radiators, in tanks

Definitions

  • the present invention relates to a pneumatic tire with a sealant layer on the inner surface of the tread portion and a manufacturing method thereof. More specifically, the present invention relates to a pneumatic tire and a manufacturing method thereof that reduces distortion in the tire and improves durability by suppressing thermal shrinkage of the belt cover layer caused by heating during the formation of the sealant layer.
  • the sealant constituting the sealant layer has generally been a rubber composition mainly composed of butyl-based rubber (see, for example, Patent Documents 1 to 3).
  • butyl-based rubber include butyl rubber (IIR) and halogenated butyl rubber such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR).
  • IIR butyl rubber
  • Br-IIR brominated butyl rubber
  • Cl-IIR chlorinated butyl rubber
  • Japanese Patent No. 6583456 Japanese Patent No. 6620851 Japanese Patent No. 7319533 Japanese Patent No. 6124967
  • the object of the present invention is to provide a pneumatic tire and a manufacturing method thereof that can reduce distortion in the tire and improve durability by suppressing the thermal shrinkage of the belt cover layer caused by heating during the formation of the sealant layer.
  • a pneumatic tire of the present invention includes a tread portion extending in a circumferential direction of the tire to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on the radially inner side of the sidewall portions, a belt layer including belt cords inclined with respect to the tire circumferential direction and a belt cover layer including organic fiber cords oriented in the tire circumferential direction on an outer circumferential side of the belt layer are embedded in the tread portion, the organic fiber cords of the belt cover layer have a heat shrinkage rate at 180°C in the range of 0.1% to 5.0%,
  • the tire is characterized in that a sealant layer is formed on the inner surface of the tread portion, and the sealant of the sealant layer is composed of a silicone-based composition.
  • a method for manufacturing a pneumatic tire according to the present invention is a method for manufacturing the above-mentioned pneumatic tire, After manufacturing a pneumatic tire excluding the sealant layer,
  • the present invention is characterized in that when a sealant made of a silicone-based composition is applied to the inner surface of the tire in the tread portion to form the sealant layer, the temperature of the sealant applied to the inner surface of the tire is lowered to less than 70°C.
  • a sealant layer containing a sealant made of a silicone-based composition is formed on the inner surface of the tire in the tread portion, making it possible to lower the temperature of the sealant applied to the inner surface of the tire.
  • the temperature of the sealant applied to the inner surface of the tire can be made lower than 70°C.
  • the silicone-based composition is preferably a two-component curing silicone.
  • Two-component curing silicone has a low viscosity immediately after mixing the two components, so it can be applied even at low temperatures.
  • the width of the sealant layer is 90% or more of the width of the belt layer.
  • the thickness of the sealant layer is in the range of 2.0 mm to 5.0 mm. This ensures puncture sealing properties while preventing deterioration of durability due to increased tire weight.
  • the distance L from the belt layer to the sealant layer is 10 mm or less at all points of the belt layer located at the innermost side in the tire radial direction. This makes it easier for the sealant to flow into the belt layer when a foreign object such as a nail penetrates the tread portion, ensuring good puncture sealing properties.
  • a sound-absorbing material is installed along the tire circumferential direction on the tire radially inner side of the sealant layer.
  • the sound-absorbing material can be installed on the sealant layer that is applied at a low temperature, so damage to the sound-absorbing material can be avoided and its sound-absorbing effect can be well maintained.
  • FIG. 1 is a meridian cross-sectional view showing a pneumatic tire according to an embodiment of the present invention.
  • FIG. 2 is a cross-sectional view showing a main part of the pneumatic tire of FIG. 3A to 3C are cross-sectional views showing a method for manufacturing the pneumatic tire of FIG.
  • FIG. 4 is a plan view showing a sealant layer formed on the inner surface of the tire in the tread portion of the pneumatic tire of FIG.
  • FIG. 5 is a meridian cross-sectional view showing a pneumatic tire according to another embodiment of the present invention.
  • Figures 1 and 2 show a pneumatic tire according to an embodiment of the present invention.
  • the pneumatic tire of this embodiment has a tread portion 1 that extends in the circumferential direction of the tire and forms an annular shape, a pair of sidewall portions 2, 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3, 3 arranged on the radially inner side of the sidewall portions 2.
  • a carcass layer 4 is mounted between a pair of bead portions 3, 3.
  • This carcass layer 4 includes multiple carcass cords extending in the tire radial direction, and is folded from the inside to the outside of the tire around the bead cores 5 arranged in each bead portion 3.
  • a bead filler 6 made of a rubber composition with a triangular cross section is arranged on the outer periphery of the bead cores 5.
  • belt layers 7 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1.
  • These belt layers 7 include multiple belt cords that are inclined with respect to the tire circumferential direction, and are arranged so that the belt cords cross each other between layers.
  • the inclination angle of the belt cords with respect to the tire circumferential direction is set in the range of 10° to 40°, for example.
  • Steel cords are preferably used as the belt cords of the belt layers 7.
  • At least one belt cover layer 8 is arranged on the outer periphery of the belt layer 7, in which reinforcing cords are arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction, in order to improve high-speed durability.
  • This belt cover layer 8 is preferably a jointless structure in which a strip material made of at least one reinforcing cord aligned and rubber-coated is continuously wound at substantially 0° with respect to the tire circumferential direction.
  • an organic fiber cord such as nylon or polyethylene terephthalate (PET) is preferably used as the reinforcing cord of the belt cover layer 8.
  • the organic fiber cord constituting the belt cover layer 8 has a heat shrinkage rate at 180°C in the range of 0.1% to 5.0%.
  • the heat shrinkage rate is the dry heat shrinkage rate (%) of the sample cord measured when heated under the conditions of a sample length of 500 mm and heating conditions of 180°C x 30 minutes in accordance with JIS L1017 "Test method for chemical fiber tire cords".
  • the above-mentioned tire internal structure shows a typical example of a pneumatic tire, but is not limited to this.
  • Various grooves including multiple main grooves 11 extending in the tire circumferential direction, are formed in the tread portion 1.
  • a sealant layer 20 is formed on the tire inner surface 10 in the tread portion 1 so as to be continuous in the tire circumferential direction. It is preferable that the center position of the sealant layer 20 in the tire width direction coincides with the tire equator, but the center position may be shifted from the tire equator to either side in the tire width direction.
  • the distance in the tire width direction between the center position of the sealant layer 20 in the tire width direction and the tire equator is preferably 10 mm or less, more preferably 5 mm or less. This prevents the sealant layer 20 from adversely affecting the tire balance.
  • the sealant of the sealant layer 20 is composed of a silicone-based composition.
  • the silicone-based composition includes a synthetic polymer compound having a main skeleton formed by siloxane bonds.
  • a sealant layer 20 containing a sealant made of a silicone-based composition is formed on the tire inner surface 10 in the tread portion 1, so that it is possible to lower the temperature of the sealant applied to the tire inner surface 10 when forming the sealant layer 20.
  • the heat shrinkage of the belt cover layer 8 due to heating when forming the sealant layer 20 is suppressed, so that the distortion caused in the pneumatic tire can be reduced and its durability can be improved.
  • the heat shrinkage rate at 180°C of the organic fiber cords constituting the belt cover layer 8 exceeds 5.0%, the distortion caused in the pneumatic tire will be large.
  • a silicone-based composition is used as the sealant of the sealant layer 20, there is also the advantage that it has excellent weather resistance and low temperature dependency of physical properties.
  • the temperature of the sealant applied to the tire inner surface 10 is 40°C or lower.
  • the lower limit of the temperature of the sealant applied to the tire inner surface 10 is preferably 20°C.
  • FIG. 3 shows a specific manufacturing method of the pneumatic tire of FIG. 1, and FIG. 4 shows a sealant layer formed on the inner surface of the tire in the tread portion.
  • the sealant extrusion device 31 mixes the sealants supplied from the pumps 32 and 33, and continuously discharges the mixed sealant from the nozzle 34 as a strip 21.
  • This sealant extrusion device 31 is configured so that the position of the nozzle 34 can be freely changed. Therefore, by moving the nozzle 34 in the axial direction of the tire while rotating the tire from a state in which the nozzle 34 is close to the inner surface 10 of the tire, the sealant strip 21 can be arranged in a spiral shape on the inner surface 10 of the tire while inclining with respect to the tire circumferential direction Tc (see FIG. 4).
  • the spirally arranged sealant strip 21 has its circumferential portions in close contact with each other.
  • the sealant strip 21 arranged in a spiral shape is integrated to form the sealant layer 20.
  • one-component curing silicone or two-component curing silicone can be used, but it is particularly preferable to use two-component curing silicone.
  • One-component curing silicone can be, for example, moisture-curing silicone.
  • Two-component curing silicone is composed of a first liquid and a second liquid, and a curing reaction begins by mixing these first and second liquids, and the stability of the sealant layer 20 is ensured after curing.
  • the first and second liquids of the two-component curing silicone are supplied from pumps 32 and 33, respectively.
  • Two-component curing silicone has a low viscosity immediately after mixing the two liquids, so it can be applied even at low temperatures.
  • Two-component curing silicones are composed of, for example, a condensation curable silyl-terminated polymer, a silane crosslinker, a condensation catalyst, and a filler.
  • condensation curable silyl-terminated polymers include polydialkylsiloxanes, alkylphenylsiloxanes, organic polymers having silyl groups (e.g., silyl polyethers, silyl acrylates), and polyisobutylenes having silyl groups.
  • silane crosslinkers include alkoxy-functional silanes, oximosilanes, acetoxysilanes, and enoxysilanes.
  • fillers include iron oxide, titanium dioxide, carbon black, and talc.
  • condensation catalysts include titanates and zirconates. These condensation curable silyl-terminated polymers, silane crosslinkers, condensation catalysts, and fillers are stored in a state where they are separated into a first liquid and a second liquid in a combination that does not cause a curing reaction to proceed, and are mixed when used.
  • two-component curing silicones include those described in Japanese Patent Publication No. 2018-503725 and Japanese Patent Publication No. 2022-550962.
  • SST-2650 manufactured by Dow can be used as a commercially available two-component curing silicone.
  • the belt cover layer 8 may cover only a portion of the belt layer 7 in the tire width direction (for example, the edge portions on both sides of the belt layer in the tire width direction), but it is preferable that it covers the entire area of the belt layer 7 in the tire width direction.
  • the effect of thermal shrinkage of the belt cover layer 7 becomes significant, so it is effective to apply a sealant layer 20 made of a silicone-based composition.
  • the width Ws of the sealant layer 20 is 90% or more of the width Wb of the belt layer 7.
  • the thickness S of the sealant layer 20 is preferably in the range of 2.0 mm to 5.0 mm. This can ensure puncture sealing while preventing deterioration of durability due to increased tire weight. If the thickness S of the sealant layer 20 is less than 2.0 mm, the puncture sealing performance will decrease, and if it is greater than 5.0 mm, the durability may decrease due to increased tire weight.
  • the thickness S of the sealant layer 20 is the overall average thickness.
  • the average thickness of the sealant layer 20 can be calculated from the measured values at a total of 40 points, for example, by taking a tire meridian cross section at eight points around the tire circumference using a CT scan, measuring the thickness of the sealant layer 20 at five points in each image taken: the tire equator position, the outer edge positions (both sides) 10 mm inward in the tire width direction from the edge of the sealant layer 20, and the intermediate positions (both sides) between the tire equator position and the outer edge position.
  • the distance (shortest distance) L from the belt layer 7 to the sealant layer 20 is 10 mm or less at all points of the belt layer 7 located at the innermost side in the tire radial direction. This makes it easier for the sealant to flow into the belt layer 7 when a foreign object such as a nail penetrates the tread portion 1, thereby ensuring good puncture sealing properties. If there is a part where the distance L from the belt layer 7 to the sealant layer 20 is greater than 10 mm, there is a risk that the puncture sealing properties in that part will be insufficient.
  • FIG. 5 shows a pneumatic tire according to another embodiment of the present invention.
  • a sound-absorbing material 40 is installed along the tire circumferential direction on the radially inner side of the sealant layer 20.
  • the sound-absorbing material 40 is made of a porous material having open cells, and has a predetermined sound-absorbing characteristic based on its porous structure. It is preferable to use foamed polyurethane as the porous material of the sound-absorbing material 40.
  • the sound-absorbing material 40 is attached onto the sealant layer 20 based on the adhesiveness of the sealant layer 20. In this case, the sound-absorbing material 40 is installed on the sealant layer 20 applied at a low temperature, so that damage to the sound-absorbing material 40 can be avoided and its sound-absorbing effect can be well maintained.
  • tires were manufactured as Comparative Examples 1-4 and Examples 1-8 in which the cord material of the belt cover layer, the heat shrinkage rate at 180°C of the organic fiber cord of the belt cover layer, the constituent material of the sealant layer, the application temperature of the sealant, and the ratio of the width of the sealant layer to the width of the belt layer were varied as shown in Table 1.
  • the thickness S of the sealant layer was 3 mm, and the distance L from the belt layer to the sealant layer was 8 mm.
  • the evaluation results were shown as " ⁇ " when the running time was 340 km/h x 10 minutes or more, “ ⁇ ” when the running time was 320 km/h x 10 minutes or more and less than 340 km/h x 10 minutes, and " ⁇ " when the running time was less than 320 km/h x 10 minutes.
  • Outer diameter distortion The outer diameter of each test tire was measured, and the error of the actual measurement value from the design value was calculated. The evaluation results were indicated by " ⁇ " when the error of the actual measurement value from the design value was within ⁇ 0.3%, by “ ⁇ ” when the error was within ⁇ 0.5%, by “ ⁇ ” when the error was within ⁇ 0.7%, and by “ ⁇ ” when the error was outside the range of ⁇ 0.7%.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Tires In General (AREA)
PCT/JP2024/036475 2023-10-18 2024-10-11 空気入りタイヤ及びその製造方法 Pending WO2025084239A1 (ja)

Priority Applications (2)

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JP2025553165A JPWO2025084239A1 (https=) 2023-10-18 2024-10-11
CN202480063054.4A CN121969509A (zh) 2023-10-18 2024-10-11 充气轮胎及其制造方法

Applications Claiming Priority (2)

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JP2023179543 2023-10-18
JP2023-179543 2023-10-18

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018520040A (ja) * 2015-07-03 2018-07-26 コンティネンタル・ライフェン・ドイチュラント・ゲゼルシャフト・ミト・ベシュレンクテル・ハフツング 粘着性シーリング材を含む空気入り自動車タイヤ
CN114953546A (zh) * 2021-02-23 2022-08-30 诺基安伦卡特股份有限公司 用于将密封剂施加到充气轮胎的内表面的方法
JP2022162823A (ja) * 2021-04-13 2022-10-25 住友ゴム工業株式会社 空気入りタイヤ

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018520040A (ja) * 2015-07-03 2018-07-26 コンティネンタル・ライフェン・ドイチュラント・ゲゼルシャフト・ミト・ベシュレンクテル・ハフツング 粘着性シーリング材を含む空気入り自動車タイヤ
CN114953546A (zh) * 2021-02-23 2022-08-30 诺基安伦卡特股份有限公司 用于将密封剂施加到充气轮胎的内表面的方法
JP2022162823A (ja) * 2021-04-13 2022-10-25 住友ゴム工業株式会社 空気入りタイヤ

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CN121969509A (zh) 2026-05-01
JPWO2025084239A1 (https=) 2025-04-24

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