Patent ID: 6057390
Filing Date: 2000-05-02
Classification: C08L

Abstract:
A method for improving high temperature performance grade properties of asphalt which comprises i) heating an asphalt cement to 200 to 500.degree. F. (93 to 260.degree. C.), ii) adding 1 wt. % to 10 wt. % crosslinkable polymer based on weight of said asphalt cement, selected from the group consisting of styrene-butadiene diblock copolymer (SB), styrene-isoprene-styrene triblock copolymer (SIS), and styrene-butadiene-styrene triblock copolymer (SBS), iii) adding a useful temperature index (UTI) improving amount of dioxime(s) of 1,4-benzoquinone and optionally, free radical initiator, and iv) mixing the resulting blend, thereby providing an asphalt having a greater useful temperature index (UTI) than a corresponding blend to which no dioxime of 1,4-benzoquinone is added.