Vehicle tyre, the tread of which comprises a heat-expandable rubber composition

Abstract

A vehicle tyre includes a tread formed of a rubber composition that is heat-expandable when unvulcanized, and expanded when vulcanized. When unvulcanized, the composition includes from 50 to 100 phr of a copolymer based on styrene and butadiene; optionally from 0 to 50 phr of another diene elastomer, such as a polybutadiene or a natural rubber; more than 50 phr of a reinforcing filler, such as silica and/or carbon black; between 5 and 25 phr of a sodium- or potassium-including carbonate or hydrogencarbonate; and between 2 and 15 phr of a carboxylic acid having a melting point between 60° C. and 220° C., such as citric acid. A total content of the carboxylic acid and the carbonate or the hydrogencarbonate is greater than 10 phr. Presence of the carboxylic acid and the carbonate or the hydrogencarbonate makes it possible to significantly reduce noise emitted by the tyre during running.

Dependencies are inferred from the claim text.