Tire tread reinforced with a silica of low specific surface area

Abstract

A tire tread incorporating an elastomeric composition reinforced by an inorganic filler, based on at least: (i) a diene elastomer; (ii) as reinforcing inorganic filler, more than 80 phr of a silica of low specific surface area having the following characteristics: (a) a BET specific surface area of less than 130 m2/g; (b) an average particle size, dw, of between 30 and 300 nm; (iii) a coupling agent providing the bond between the reinforcing inorganic filler and the diene elastomer; (iv) a vulcanization system comprising sulfur, a vulcanization accelerator and between 0.5 and 1.5 phr of zinc as vulcanization activator. Preferably, this silica furthermore has a disagglomeration rate α greater than 5×103 μm−1/min (measured in the ultrasound disagglomeration test). Compared with a conventional tread for “Green Tires” which is reinforced with a silica of higher specific surface area, the tread of the invention has an improved compromise of (wear resistance/rolling resistance/grip on wet ground) performances. The use of a very small amount of zinc makes it possible to overcome an increase in the induction delays during the vulcanization, when such a silica of low specific surface area is used.

Dependencies are inferred from the claim text.