Patent ID: 7951239
Filing Date: 2011-05-31
Classification: C08L,C09D,C10C

Abstract:
1. A method of producing a roofing shingle coating asphalt from a non-coating grade asphalt feedstock comprising the following steps: partially blowing the non-coating grade asphalt feedstock 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; adding a blowing catalyst to the non-coating grade asphalt before or during the blowing; and then adding a wax 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, wherein the wax has a melt point of at least about 90° C.