Patent attributes
In a process of producing a roofing shingle coating asphalt from a low flashpoint asphalt feedstock, an asphalt feedstock which has a low flashpoint of from 490° F. (254° C.) to 540° F. (282° C.) is partially blown, and wax is added to the asphalt feedstock. The process produces a coating asphalt having a low melt viscosity of from 50 cps to 150 cps at 400° F. (204° C.), a softening point of from 190° F. (88° C.) to 235° F. (113° C.) and a penetration of at least 15 dmm at 77° F. (25° C.). In another embodiment, the process produces a roofing shingle coating asphalt having good weatherability from a poor weathering asphalt feedstock. In a further embodiment, the process produces roofing shingles including a filled coating containing a poor tear filler without sacrificing the tear strength of the shingles.