Pneumatic tire

摘要

To provide a pneumatic tire by which rolling resistance is reduced while cracking resistance in side wall portions is maintained. A foam rubber layer 6 extending in a tire radial direction is disposed in at least a portion of the side wall portion 3. Heat conductivity at 23° C. of the foam rubber layer 6 is from 0.05 to 0.20 W/mK, a tan δ at 60° C. is not more than 0.17, and an expansion ratio Q is from 50 to 160%.

主权项

1. A pneumatic tire comprising a left-right pair of bead portions, a side wall portion continuous with the bead portions, and a tread portion connected to the side wall portion, a carcass layer being mounted between the left-right bead portions: wherein
a foam rubber layer extending in a tire radial direction is disposed in at least a portion of the side wall portion, heat conductivity at 23° C. of the foam rubber layer is from 0.05 to 0.20 W/mK, a tan δ at 60° C. of the foam rubber layer is not more than 0.17, and an expansion ratio Q as defined in formula (I) below is from 50 to 160%:
Expansion ratio Q(%)=[(D0/D1)−1]×100  (1) wherein, D0 is a specific weight of the foam rubber layer before foaming and D1 is a specific weight after foaming.