Patent ID: 7338991

Claim:
A method for preparing polymer modified asphalt compositions comprising: mixing asphalt and an elastomeric polymer to form a mixture; adding a crosslinker to the mixture at a crosslinking temperature of above 180° C. and within a temperature range of 20° C. wide to form the polymer modified asphalt composition, wherein the crosslinker is selected from the group consisting of a sulfur-containing derivative, elemental sulfur and mixtures thereof; wherein the sulfur-containing derivative is a thiuram polysulfide having a formula of: where R 1 and R 2 are the same or different alkyl substituents having from 1 to 4 carbon atoms, M is a metal selected from zinc, barium or copper and n is 0 or 1; and determining a top and bottom softening point of the polymer modified asphalt composition, wherein the crosslinking temperature is adapted to control the compatibility of the polymer modified asphalt composition, resulting in a difference between the top and bottom softening points of 20° C. or less, using a ring and ball softening point test.