| 摘要 |
837,849. Tyre treads. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Sept. 8, 1958 [June 18, 1957], No. 19177/57. Class 144 (2). For improved skid resistance a tyre tread is formed of a natural or synthetic rubber having a rebound resilience, as defined Standard B,S. 903, 22, 1950, of the British Standards Institution of not more than 40% in the temperature range - 10 to 50‹ C. Such rubber has a high hysteresis loss and is preferably used in conjunction with sidewalls of rubber having a rebound resilience of at least 60% in the same temperature range. The synthetic rubbers may comprise butyl, butadiene-acrylonitrile or an organic polysulphide type and where necessary may be bonded to the carcase by means of a tie layer to ensure good adhesion. Such tie layer, or the tyre carcase where no tie layer is used, should be a different colour from the tread layer to provide an indication of full wear. |
