Patent ID: 7341624

Claim:
An asphalt composition made by a plurality of steps comprising: heating a base asphalt to a temperature of from 300° F. to 400° F.; introducing a polymer selected from the group consisting of block copolymers, elastomeric polymers, or a combination thereof to form an asphalt concentrate and blending the asphalt concentrate, wherein said concentrate has from 5 wt % to 12 wt % of the polymer; adding zinc oxide before the acid and before or after the polymer and blending the concentrated asphalt, wherein zinc oxide is used as an additive for reducing hydrogen sulfide emissions; adding from 0.01 wt. % to less than 5 wt. % of a mineral acid, and blending the concentrated asphalt; wherein at least a portion of one or more of the blendings after zinc oxide addition occurs in the presence of an oxygen containing gas; and adding further additives comprised of sulfur and mercaptobenzothizole (MBT) to the asphalt.