| abstract |
The inner wall of a pneumatic tyre, in the vulcanized state, is provided with a layer of polyurethane foam, characterized in that the polyurethane is based on a diphenylmethane diisocyanate (MDI), in particular 4,4′-diphenylmethane diisocyanate, and on a polyol having an ethylene oxide content of greater than 50% (% by weight). This specific polyurethane formulation makes it possible to obtain a light foam that efficiently absorbs noise; it has the advantages of being simple and inexpensive and of being easy to process by direct casting of the reactants in the pneumatic tyre of the invention. |