Tire whose tread comprises elements of the tread pattern with walls lateral comprising a rigid thermoplastic - expandable rubber the raw state, or rubber foam has the cured state.

摘要

The invention relates to a cured or uncured tire, the tread of which comprises a plurality of tread pattern features (1) that are formed from a first rubber material, a so-called "base" material (MB), and defined by cut-outs (3, 4). Said tread pattern features include a contact surface (2), for making contact with the road while the tire is rolling, and at least one sidewall (13, 14, 15, 16). On at least one sidewall of all or part of said tread pattern features, the base material is at least partially coated with a layer of a second rubber material, a so-called "coating" material (MR), different from the base material and comprising at least one rubber composition. Said tire is characterized in that said rubber composition of the coating material is heat-expandable in the tire in the uncured state and takes a foam rubber form in the tire in the cured state. Said tire is moreover characterized in that said rubber composition comprises, in the tire in the uncured state as well as the cured state, at least: 50 to 100 phr of a styrene unit and butadiene unit copolymer, the glass transition temperature of which is greater than -40°C; optionally, 0 to 50 phr of another diene elastomer; more than 50 phr of a reinforcing filler; more than 25 phr of a plastifying hydrocarbon resin, the glass transition temperature of which is greater than 20°C; and optionally, 0 to less than 20 phr of a liquid plastifying agent.