Method of producing roofing shingle coating asphalt from non-coating grade asphalt

摘要

A method of producing a roofing shingle coating asphalt from a non-coating grade asphalt feedstock includes the following steps. The non-coating grade asphalt feedstock is partially blown to lower its penetration to a first penetration that is within or close to a target penetration range of the coating asphalt, and to raise its softening point to a first softening point that is lower than a target softening point range of the coating asphalt. Then a wax is added to the partially blown non-coating grade asphalt to further raise its softening point to a second softening point that is within the target softening point range to produce the coating asphalt.