| 摘要 |
PURPOSE:To improve the frictional force on an ice snow road by constituting a tread part having a specific value of the average gas foam area of the surface form a specific kind of foamed rubber and short fibers and arranging the short fibers along the block surface and side surface of the tread part in the foamed rubber. CONSTITUTION:A tread part 13 is constituted of a polymer having a glass transition temperature from -60 to -20 deg.C foamed rubber which has independent gas foams and contains the urea group assisting agent having at most the equal quantity to the foaming agent compounding quantity and short fibers 17. At this time, the short fibers 17 are directed along the obverse surface (a) and side surface (b) of the block 16 of the tread part 13. Further, the average gas foam area of a tread surface 10 is set to 100-5,000mum<2>, and the variation coefficient of each gas foam area is set to 0.5-0.8, and the gas foam occupation area rate is set to 1-4%. |
