| CPC B60C 9/1821 (2013.01) [B60C 9/0064 (2013.01); B60C 9/20 (2013.01); B60C 11/0008 (2013.01); B60C 11/033 (2013.01); C08L 9/06 (2013.01); B60C 2001/0066 (2013.01); B60C 2009/2077 (2013.01); B60C 2009/2083 (2013.01); B60C 2011/0025 (2013.01); C08L 2205/03 (2013.01)] | 13 Claims |
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1. A pneumatic tire having a tread portion with 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 arranged per 5 cm in the tire width direction in the tire radial cross section of the belt layer is 50/5 cm or more,
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 cord, and
the loss tangent (30° C. tan δ) satisfies 30° C. tan δ≤0.11 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,
30° C. tan δ×G<1.0 formula 2
the outer diameter of the monofilament steel cord is 0.1 mm to 0.5 mm,
the number of arrangements e (lines/5 cm) of the monofilament steel cord and the outer diameter r (mm) of the monofilament cord steel satisfy formula 3,
e×r2/4×π>4.0 formula 3
the loss tangent (0° C. tan δ) and the distance G (mm) satisfy formula 5,
0° C. tan δ/G<0.14 formula 5
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