| 摘要 |
PURPOSE:To promote the capacity of wet braking and the durability of a cap tread without reducing the rolling resistance by using a specified mixture rubber of polybutadiene rubber of a prescribed structure mixed with an assigned amount of sulphur respectively for the cap tread and an under tread layer. CONSTITUTION:Ram material rubber is made from 25-75pts.wt. of 65-90mol% polybutadiene rubber in 1-2 combination unit and 75-25pts.wt. natural rubber and/or polyisoprene rubber. For a cap tread, sulphur in the range of 0.5-1.6pts.wt. is mixed with 100pts.wt of this raw material rubber component, and a rubber of more than 33% elongation before breaking in 100 deg.C is used. Meanwhile, for an under tread layer, sulphur in the range of 1.8-10pts.wt. is mixed with 100pts.wt. of this raw material rubber component, and a 0.5-3mm. thick rubber is used. |
