	US 12,275,281 B2
	Pneumatic tire
Kenji Hamamura, Hyogo (JP); Hiroki Kawai, Hyogo (JP); and Subaru Toya, Hyogo (JP)
Assigned to SUMITOMO RUBBER INDUSTRIES, LTD., Hyogo (JP)
Appl. No. 18/017,785
Filed by SUMITOMO RUBBER INDUSTRIES, LTD., Hyogo (JP)
PCT Filed Jul. 21, 2021, PCT No. PCT/JP2021/027376 § 371(c)(1), (2) Date Jan. 24, 2023, PCT Pub. No. WO2022/024933, PCT Pub. Date Feb. 3, 2022.
Claims priority of application No. 2020-127600 (JP), filed on Jul. 28, 2020.
Prior Publication US 2023/0286321 A1, Sep. 14, 2023
Int. Cl. B60C 3/04 (2006.01); B60C 1/00 (2006.01); B60C 11/00 (2006.01); B60C 11/03 (2006.01)

CPC B60C 3/04 (2013.01) [B60C 1/0016 (2013.01); B60C 11/0058 (2013.01); B60C 11/033 (2013.01); B60C 2011/0033 (2013.01); B60C 2011/0341 (2013.01); B60C 2011/0358 (2013.01)]

21 Claims

1. A pneumatic tire having a tread portion, wherein

the tread portion has a ground-contacting surface made of at least two types of rubber compositions having different thermal conductivities,

when the cross-sectional width of the tire is Wt (mm), the outer diameter is Dt (mm), and the volume of the space occupied by the tire is the virtual volume V (mm³), when the tire is installed on a standardized rim and the internal pressure is 250 kPa, the tire satisfies following (formula 1) and (formula 2):

1700≤(Dt²×π/4)/Wt≤2827.4 (formula 1)

[(V+1.5×10⁷)/Wt]≤2.88×10⁵ (formula 2)

wherein, when the thermal conductivity of the rubber composition with the highest thermal conductivity is Ka (W/m·K), and the thermal conductivity of the rubber composition with the lowest thermal conductivity is Kb (W/m·K), among the at least two types of rubber compositions having different thermal conductivities, the following (formula 6) is satisfied:

0.11≤Ka−Kb≤0.24 (formula 6).