US 12,168,371 B2
Pneumatic tire
Momoka Misaki, Kobe (JP); Dong Miao, Kobe (JP); and Hiroki Kawai, Kobe (JP)
Assigned to SUMITOMO RUBBER INDUSTRIES, LTD., Kobe (JP)
Filed by SUMITOMO RUBBER INDUSTRIES, LTD., Kobe (JP)
Filed on Dec. 28, 2021, as Appl. No. 17/563,507.
Claims priority of application No. 2021-000588 (JP), filed on Jan. 5, 2021.
Prior Publication US 2022/0212504 A1, Jul. 7, 2022
Int. Cl. B60C 11/00 (2006.01); B60C 9/18 (2006.01); B60C 9/28 (2006.01); B60C 11/03 (2006.01)
CPC B60C 11/0008 (2013.01) [B60C 9/28 (2013.01); B60C 11/03 (2013.01); B60C 2011/0025 (2013.01); B60C 2011/0033 (2013.01); B60C 2011/0341 (2013.01); B60C 2011/0358 (2013.01)] 14 Claims
 
1. A pneumatic tire having a tread portion formed from a rubber composition which includes a circumferential groove and a belt layer, wherein
the belt layer includes a monofilament steel cord as a reinforcing cord,
the number of arrangements e (lines/5 cm) of the monofilament steel cords per 5 cm in the tire width direction in the tire radial cross section of the belt layer,
the distance G (mm) is 6.0 mm or more and 10.0 mm or less, from the surface of the land portion closest to the equatorial plane among land portions separated by the circumferential groove to the monofilament steel cord,
the loss tangent (0° C. tan δ) is 0.5 or more when the rubber composition constituting the surface of the tread portion is measured under conditions of temperature: 0° C., initial strain: 5%, dynamic strain: ±0.25%, frequency: 10 Hz, and deformation mode; tensile,
the loss tangent (30° C. tan δ) satisfies 30° C. tan δ≥0.17 when the rubber composition constituting the surface of the tread portion is measured under conditions of temperature: 30° C., initial strain: 5%, dynamic strain: ±1%, frequency: 10 Hz, and deformation mode: tensile, and satisfies formula 2,
0.016≤(30° C. tan δ×G)/e≤0.028  formula 2,
the outer diameter of the monofilament steel cord is 0.1 mm to 0.5 mm, and
the number of arrangements e (lines/5 cm) of the monofilament steel cord and the outer diameter r (mm) of the monofilament steel cord satisfy formula 4,
e×r2/4×π>4.0  formula 4.