| 摘要 |
PURPOSE:To make it possible to form a tire rubber composition very low in a decrease in tensile strength and remarkably improved in modulus and cutting resistance without adversely affecting its heat buildup property, by using short aramid fibers of a specified size. CONSTITUTION:This tire rubber composition contains short aramid fibers of a diameter of 5-50mum and a length of 50-500mum. It is preferable that the amount of said fibers is 1-10pts.wt. per 100pts.wt. rubber. In order to obtain said short fibers, a process comprising blending short aramid fiber/SBR mixture (masterbatch) formed by mixing short aramid fibers with a styrene/butadiene copolymer rubber (SBR) by a wet process with other diene rubbers is preferable. Examples of said diene rubbers which can be particularly desirably used include a styrene/butadiene copolymer rubber and a natural rubber. In order to prepare a masterbatch of the short aramid fibers, it is desirable to use an aramid pulp of a length of 1-5mm as said short aramid fibers. |
