Abstract: 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. 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. The wax may also be added during the blowing process. Resulting roofing coating asphalt compositions may comprise a paving grade asphalt and a wax, and yet still has desirable penetration, softening point and viscosity.

Abstract: 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. 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. The wax may also be added during the blowing process. Resulting roofing coating asphalt compositions may comprise a paving grade asphalt and a wax, and yet still has desirable penetration, softening point and viscosity.

Abstract: 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.