ROAD PAVING BINDERS

摘要

This invention provides for novel road paving binder compositions and the method of making them. One embodiment is a road paving binder composition of a storage stable blend of a sulfonated, unhydrogenated random copolymer of sytrene and butadiene having a sulfonation level of from 1 to 100 meq SO3H/100 g of polymer and a sulfonated asphalt. Another is a method of making a storage stable polymer modified asphalt composition by combining a sulfonated unhydrogenated random styrene butadiene copolymer having a sulfonation level of from about 1 to 100 meq SO3H per 100 g of polymer and a sulfonated asphalt at a temperature of at least about 180 DEG C to produce a storage stable polymer modified asphalt. Yet another is a method of making a storage stable polymer modified asphalt by combining a sulfonated unhydrogenated random styrene and butadiene copolymer having a sulfonation level of from about 1 to 100 meq SO3H/100 g of polymer, and unsulfonated asphalt and a basic neutralizing agent at a temperature of from about 170 DEG C to 185 DEG C to produce a storage stable polymer modified asphalt. Still another is a method for making a storage stable road paving composition by cosulfonation of a blend of unhydrogenated random styrene-butadiene copolymer and an asphalt at 180 DEG -210 DEG C. The novel road paving asphaltic compositions have enhanced viscoelasticity and storage stability. The compositions can be used as binders in road paving applications. Sulfonated copolymers of random styrene-isoprene may be substituted for the sulfonated copolymers of styrene-butadiene herein.