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JP-2026074775-A - tire

JP2026074775AJP 2026074775 AJP2026074775 AJP 2026074775AJP-2026074775-A

Abstract

[Problem] To provide a tire that can improve the wear resistance and wet performance of the tire. [Solution] In this tire 1, the tire outer diameter OD [mm] is in the range of 200 ≤ OD ≤ 660, and the tire total width SW [mm] is in the range of 100 ≤ SW ≤ 400. The tire 1 also has a tread rubber 15 containing a thermoplastic resin. The content Q [parts by mass] of the thermoplastic resin in the tire rubber composition is in the range of 5 ≤ Q ≤ 120 relative to the diene rubber 100 [parts by mass]. Furthermore, the content Q [parts by mass] of the thermoplastic resin is in the range of 0.008 ≤ Q/OD ≤ 0.450 and 0.020 ≤ Q/SW ≤ 0.850 relative to the tire outer diameter OD [mm] and the tire total width SW [mm]. [Selection Diagram] Figure 1

Inventors

  • 新井 晴香
  • 佐藤 正樹

Assignees

  • 横浜ゴム株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (15)

  1. A tire comprising a pair of bead cores, a carcass layer spanning the pair of bead cores, a belt layer positioned radially outward of the carcass layer, and a tread rubber positioned radially outward of the belt layer, The tire outer diameter OD [mm] is in the range of 200 ≤ OD ≤ 660. The total tire width SW [mm] is in the range of 100 ≤ SW ≤ 400. The tire rubber composition includes a thermoplastic resin, The content Q [parts by mass] of the thermoplastic resin in the tire rubber composition is in the range of 5 ≤ Q ≤ 120 relative to the diene rubber 100 [parts by mass], and A tire characterized in that the content Q [parts by mass] of the thermoplastic resin is in the range of 0.008 ≤ Q/OD ≤ 0.450 and 0.020 ≤ Q/SW ≤ 0.850 with respect to the tire outer diameter OD [mm] and the tire total width SW [mm].
  2. A tire comprising a pair of bead cores, a carcass layer spanning the bead cores, a belt layer positioned radially outward of the carcass layer, and a tread rubber positioned radially outward of the belt layer, The tire outer diameter OD [mm] is in the range of 200 ≤ OD ≤ 660. The total tire width SW [mm] is in the range of 100 ≤ SW ≤ 400. The tire rubber composition includes a thermoplastic resin, The content Q [parts by mass] of the thermoplastic resin in the tire rubber composition is in the range of 5 ≤ Q ≤ 120 relative to the diene rubber 100 [parts by mass], and A tire characterized in that the content Q [parts by mass] of the thermoplastic resin is in the range of 0.035 ≤ (Q × LI') / (OD × SW) ≤ 1.900 with respect to the tire outer diameter OD [mm], the tire total width SW [mm], and the load LI' [kgf] which is 120% of the specified load LI.
  3. The tire according to claim 1 or 2, wherein the tread rubber comprises the tire rubber composition.
  4. The tire according to claim 1 or 2, wherein the glass transition temperature of the thermoplastic resin is in the range of 20°C to 120°C.
  5. The tire according to claim 1 or 2, wherein the thermoplastic resin is at least one selected from the group consisting of a resin comprising at least one selected from terpenes, modified terpenes, rosin, rosin esters, C5 components, C9 components, and C5C9 copolymer components, and a resin in which at least a portion of the double bonds of such resins are hydrogenated.
  6. The tire according to claim 1 or 2, wherein the tire rubber composition contains 20 parts by mass or more of styrene-butadiene rubber in 100 parts by mass of diene rubber.
  7. The tire according to claim 6, wherein the glass transition temperature of the styrene-butadiene rubber is -40°C or lower.
  8. The tire according to claim 1 or 2, wherein the tire rubber composition contains 30 parts by mass or more and less than 150 parts by mass of a white filler per 100 parts by mass of diene rubber.
  9. The tire according to claim 1 or 2, wherein the tire rubber composition contains 5 to 100 parts by mass of carbon black per 100 parts by mass of diene rubber.
  10. The tire according to claim 1 or 2, wherein the tire rubber composition contains 10 parts by mass or more of natural rubber or isoprene rubber in 100 parts by mass of diene rubber.
  11. The tire according to claim 1 or 2, wherein the rubber gauge Gce [mm] of the tread rubber at the tire's equatorial plane is in the range of 0.05 ≤ Gce/OD × 10 ≤ 0.70 with respect to the tire's outer diameter OD [mm].
  12. The tire according to claim 1 or 2, wherein the rubber gauge Gce [mm] of the tread rubber at the tire's equatorial plane is in the range of 0.15 ≤ Gce/SW × 10 ≤ 1.05 with respect to the total tire width SW [mm].
  13. The tire according to claim 1 or 2, wherein the belt layer has a pair of cross belts consisting of a wide cross belt and a narrow cross belt, and the distance Tce [mm] from the tread profile at the tire's equatorial plane to the outer surface of the wide cross belt is in the range of 0.08 ≤ Tce/OD × 10 ≤ 1.30 with respect to the tire's outer diameter OD [mm].
  14. The tire according to claim 1, wherein the belt layer has a pair of cross belts consisting of a wide cross belt and a narrow cross belt, and the distance Tsh [mm] from the tread profile at the tire contact edge to the outer surface of the wide cross belt is in the range of 0.50 ≤ Tsh/Tce ≤ 1.70 with respect to the distance Tce [mm] at the tire equator.
  15. The tire according to claim 1, wherein the belt layer has a pair of cross belts consisting of a wide cross belt and a narrow cross belt, and the distance Tsh at the tire contact edge is in the range of 1.50 ≤ Tsh/Tu ≤ 8.50 with respect to the rubber gauge Tu [mm] from the end of the wide cross belt to the outer surface of the carcass layer.

Description

This invention relates to a tire, and more specifically, to a tire capable of improving wear resistance and wet performance. In recent years, small-diameter tires have been developed for vehicles with lowered floors to expand interior space. These small-diameter tires have low rotational inertia and low tire weight, which is expected to reduce transportation costs. However, small-diameter tires require high load capacity. Regarding conventional tires addressing these challenges, the technology described in Patent Document 1 is known. International Publication No. 2020/122169 Figure 1 is a cross-sectional view of a tire in the meridian direction, showing a tire according to an embodiment of this invention.Figure 2 is an enlarged view of the tire shown in Figure 1.Figure 3 is an explanatory diagram showing the laminated structure of the tire belt layer described in Figure 1.Figure 4 is an enlarged view showing the tread portion of the tire described in Figure 1.Figure 5 is an enlarged view showing one side of the tread area described in Figure 4.Figure 6 is a diagram showing the results of a performance test of a tire according to an embodiment of this invention.Figure 7 is a diagram showing the results of a performance test of a tire according to an embodiment of this invention.Figure 8 is a diagram showing the results of a performance test of a tire according to an embodiment of this invention. The present invention will be described in detail below with reference to the drawings. However, this embodiment does not limit the present invention. Furthermore, the components of this embodiment include those that are substituted and obvious for substitution while maintaining the identity of the invention. Also, the various modifications described in this embodiment can be arbitrarily combined within the scope of what is obvious to those skilled in the art. [tire] Figure 1 is a cross-sectional view of a tire 1 according to an embodiment of the present invention, taken in the meridian direction of the tire. The figure shows a cross-sectional view of one side region in the radial direction of the tire 1 mounted on a rim 10. In this embodiment, a pneumatic radial tire for passenger cars will be described as an example of a tire. In this figure, the tire meridian cross-section is defined as the cross-section obtained when the tire is cut by a plane containing the tire rotation axis (not shown). The tire equatorial plane CL is defined as a plane passing through the midpoint of the tire cross-sectional width DW as defined by JATMA and perpendicular to the tire rotation axis. The tire width direction is defined as the direction parallel to the tire rotation axis, and the tire radial direction is defined as the direction perpendicular to the tire rotation axis. Point T is the tire contact point, and point Ac is the tire's maximum width position. The tire 1 has an annular structure centered on the tire rotation axis and comprises a pair of bead cores 11, 11, a pair of bead fillers 12, 12, a carcass layer 13, a belt layer 14, a tread rubber 15, a pair of sidewall rubbers 16, 16, a pair of rim cushion rubbers 17, 17, and an inner liner 18 (see Figure 1). The pair of bead cores 11, 11 are formed by winding one or more bead wires made of steel in a ring-like and multi-layered manner, and are embedded in the bead portion to form the cores of the left and right bead portions. The pair of bead fillers 12, 12 are respectively arranged on the outer circumference of the pair of bead cores 11, 11 in the radial direction of the tire to reinforce the bead portion. Furthermore, the bead fillers 12 have a rubber hardness Hs_bf of 55 to 105, a modulus M_bf [MPa] at 100% elongation of 2.0 to 13.0, and a loss tangent tanδ_bf of 0.03 to 0.30, preferably a rubber hardness Hs_bf of 70 to 100, a modulus M_bf [MPa] at 100% elongation of 3.0 to 12.0, and a loss tangent tanδ_bf of 0.05 to 0.25. The carcass layer 13 has a single-layer structure consisting of one carcass ply or a multi-layer structure consisting of multiple carcass ply layers, and is stretched in a toroidal manner between the left and right bead cores 11, 11 to form the tire's skeleton. The ends of the carcass layer 13 are wrapped back outward in the tire width direction and secured to enclose the bead cores 11 and bead filler 12. The carcass ply of the carcass layer 13 is constructed by coating multiple carcass cords made of inorganic fibers (e.g., steel, carbon fiber, glass fiber) or organic fiber materials (e.g., aramid, nylon, polyester, rayon, etc.) with a rubber coating and then rolling it. It has a cord angle of 80 degrees to 100 degrees (defined as the longitudinal inclination angle of the carcass cords relative to the tire's circumferential direction). The belt layer 14 is formed by stacking multiple belt plies 141 to 144 and is arranged around the outer circumference of the carcass layer 13. In the configuration shown in Figure 1, the belt plies 141 to 144 consist of a pai