| 摘要 |
PURPOSE:To obtain the subject product, having a tread part composed of a composition prepared by blending a rubber component with specific PVA powder and staple fiber oriented in a specified direction and improved in frictional force on ice and snow roads, especially on ice without impairing the runnability on open roads. CONSTITUTION:The objective product having a tread part, composed of a rubber composition prepared by blending 100 pts.wt. rubber component with 1-15 pts.wt. PVA powder having 10-70cPs viscosity, >=80mol% saponification degree and 30-1000mum average grain diameter and staple fiber 17 and having <=8 difference in JIS hardness between 20 and -10 deg.C. Most of the staple fiber 17 is oriented along the surface (a) and sides (b) of a block 16 in the tread part. Cellulosic staple fiber such as rayon is preferred as the staple fiber. Furthermore, the staple fiber preferably has >=1mum average diameter, 1000-3000mum average length and 10-100 ratio of the length/the diameter so as to orient in the flow direction of the rubber in extrusion molding of the tread part. |
