Patent ID: 8952092
Filing Date: 2015-02-10
Classification: C04B,C08F,C08L

Abstract:
1. A method of making a polymer-modified asphalt, comprising: polymerizing styrene and butadiene in an aqueous medium at a temperature of 40° C. or greater to produce an uncured styrene-butadiene copolymer, wherein said polymerizing step occurs in the absence of acid monomers and produces a non-carboxylated styrene-butadiene copolymer; mixing a sulfur curing agent with the non-carboxylated styrene-butadiene copolymer to form an aqueous dispersion, said curing agent allowing the non-carboxylated styrene-butadiene copolymer to cure, and blending asphalt and the aqueous dispersion at a blending temperature exceeding the boiling point of water.