| 摘要 |
PURPOSE:To improve drive feeling and reduce the noise in car interior by constituting a tread layer from a plurality of layers including a surface layer having a prescribed dynamic modulus and setting the total sum of the products of each average thickness of layers and each loss tangent of the layers within a prescribed range. CONSTITUTION:The hardness of the surface layer of a tread layer 2 is varied by only 1.5mm. thickness, and a dynamic modulus E is formed to 115kg/cm<2> or less, and a tread layer 2 is constituted of a plurality of layers a-c. Further, over the whole of the tread layer 2, the total sum Dt of the products of each average thickness Tt1-Tt3 of the layers a-c and each loss tangent tandelta1-tandelta3 of the layers is set within 0.35-0.55cm. Further, the product of the thickness ts in the normal direction to the profile surface at the part indicating the thinnest gauge in a sidewall part 6 and the loss tangent tandeltas of the sidewall part is set at least 0.05cm. |
