Asphalt composition

Abstract

An asphalt composition comprises asphalt mixed with an asphalt modifier, which combines a thermoplastic elastomeric copolymer and an effective amount of a fibrillated polytetrafluoroethylene and molybdenum disulfide particles. The thermoplastic elastomeric copolymer preferably comprises two incompatible polymers forming a two-phase copolymer including a thermoplastic end block polymer and an elastomeric mid block polymer. Preferably, the thermoplastic end block polymer is a styrene polymer and the elastomeric mid block polymer is selected from a group consisting of polybutadiene, polyisoprene and poly(ethylene-butylene). The asphalt modifier is made by mixing together under high shear, as for example, in a twin screw extruder, particles of a thermoplastic elastomeric copolymer, fibrillatable polytetrafluoroethylene and molybdenum disulfide until the fibrillatable polytetrafluoroethylene is substantially fibrillated and combined with the thermoplastic elastomeric copolymer. A preferred asphalt modifier comprises about 2 to about 12 parts of fibrillated polytetrafluoroethylene and molybdenum disulfide particles per 100 parts by weight of copolymer, with the ratio of fibrillated polytetrafluoroethylene to molybdenum disulfide being about 3 to 1 by weight.

Dependencies are inferred from the claim text.