| 摘要 |
PROBLEM TO BE SOLVED: To reduce the electric resistance while suppressing the hysteresis loss without reducing reinforcing property by mixing a conductive short fiber consisting of a reinforcing short fiber covered with a conductive material to a diene rubber. SOLUTION: A tread rubber 9 arranged in the outside of a belt layer 7 to form a tread part 2 is formed of a rubber composition 10 obtained by mixing 2-30 pts.wt. of conductive short fiber consisting of a reinforcing short fiber covered with a conductive material to 100 pts.wt. of a rubber base 100. As the reinforcing short fiber, an organic fiber such as nylon, rayon or the like or an inorganic fiber such as glass, alumina or the like can be used. The fiber length is desirably set into a range of 10-6000μm from the viewpoint of reinforcing effect, and when it is out of this range, the blending as short fiber is obstructed, and the dispersion is also reduced. The smaller fiber diameter is advantageous for conductivity, but it is preferably 1-10μm, because the fibers are excessively entangled to cause a dispersion failure when it is too small so that an uniform rubber composition can be hardly obtained.
|
