Effect of conductive carbon black on electrical conductivity and performance of tire tread compounds filled with carbon black/silica hybrid filler

For green tires, carbon black (CB) is partially replaced by silica (SiO 2 ) in the tread formula in order to improve wet grip (WG) and fuel saving efficiency (FSE). However, such replacement inversely affects electrical conductivity of a tire resulting a greater potential for static shock or electrostatic ignition. This work aimed to improve electrical conductivity of the tread compound by partially replacing either CB or SiO 2 by 0–12 phr of conductive carbon black (CCB) (with replacing ratio of 2:1) and investigating the effect of such replacement on the tire performance. Although the partial replacement of CB or SiO 2 by CCB increased the magnitude of transient filler network resulting in the negative effects on heat build‐up, WG and FSE of the tread vulcanizates, it significantly improved electrical conductivity. Surface resistivity decreased sharply when CB or SiO 2 was replaced by 3 phr of CCB, revealing the point of percolation threshold. In addition, the partial replacement of CB or SiO 2 by CCB did not cause significantly change of both hardness and tensile properties. At any given CCB loading, the SiO 2 replacement provided greater surface conductivity and higher abrasion resistance with lower WG and FSE than the CB replacement.