Patent ID: 7338991
Filing Date: 2008-03-04
Classification: C08K,C08L

Abstract:
1. 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 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.