A polymer-modified rubber composition is formed by blending together about 5% to about 60% vulcanized styrene-butadiene rubber crumb; about 5% to about 60% uncured rubber; about 5% to about 30% styrene-based thermoplastic resin; about 1% to about 10% homogenizing agent adapted to facilitate blending...http://www.google.es/patents/US5510419?utm_source=gb-gplus-sharePatente US5510419 - Polymer-modified rubber composition
