Tyre, the inner wall of which is provided with a heat-expandable rubber layer

摘要

A heat-expandable rubber layer is provided to an inner all of a pneumatic tire when the tire is in an uncured state. The rubber layer is expanded when the tire is in a vulcanized state. Once expanded, the rubber layer is capable of reducing rolling noises of the tire. The rubber layer includes an elastomer composition based on at least an elastomer, e.g., natural rubber or butyl rubber; a reinforcing filler, e.g., silica and/or carbon black; between 10 and 80 phr of a blowing agent, e.g., an azodicarbonamide compound; and between 10 and 50 phr of a hot-melt compound with a melting point between 70° C. and 150° C., e.g., urea. The combination of the blowing agent and the hot-melt compound, at recommended high contents, makes it possible to very greatly reduce an expansion ratio and therefore a thickness of the rubber layer once the pneumatic tire is vulcanized, without affecting noise absorption properties provided by the blowing agent.

主权项

1. A pneumatic tyre in an unvulcanized state, the tyre comprising:
an inner wall; and a heat-expandable rubber layer positioned on the inner wall, the heat-expandable layer being formed of an elastomer composition including at least:
an elastomer,a reinforcing filler,between 20 and 80 phr of a blowing agent, andbetween 10 and 50 phr of a hot-melt compound having a melting point between 70° C. and 150° C.