A vulcanized rubber comprising a rubber component containing natural rubber, in an amount of 20 to 70 parts by weight, and polybutadiene, in an amount of 30 to 80 parts by weight; a rubber matrix containing 5 to 55 parts by weight of carbon black and 5 to 55 parts by weight of silica per 100 parts per...http://www.google.es/patents/US6427738?utm_source=gb-gplus-sharePatente US6427738 - Tire and vulcanized rubber including elongated cells
Tire and vulcanized rubber including elongated cells
