Ridout & Maybee
Polymer-modified rubber composition
 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 of aromatic-based with non aromatic-based polymers; and about 1% to about 10% curing agent for the uncured rubber; to form a blend wherein the thermoplastic resin (c) is substantially homogeneously blended with the rubbers (a) and (b). All major components of the composition may be derived from the post industrial and post consumer waste stream. The compositions have excellent physical properties, especially stiffness and stiffness retention at elevated temperatures. 
National Rubber Technology Inc.
C C C B C B C C B B
C08L C08L C08L B29K C08L B29B C08K C08L B29K B29K
inventional additional inventional additional additional inventional additional additional additional additional
James R. James F. Michael D.
Jury Fisher Burgoyne