Process of producing roofing shingle coating asphalt

A process of producing a roofing shingle coating asphalt from an asphalt feedstock comprising:

• partially blowing the asphalt feedstock to raise its softening point to a first softening point that is lower than a target range;
• adding wax to the partially blown asphalt, said wax having a melt point of at least about 90° C.;
• and
• further blowing the asphalt to further raise its softening point to a second softening point that is within the target range;
• and
• adding a blowing catalyst to the asphalt before or during the blowing;
• the process producing a coating asphalt having a softening point within the target range of from about 190° F. (88° C.) to about 235° F. (113° C.) and having a penetration of at least about 15 dmm at 77° F. (25° C.).

A process of producing a roofing shingle coating asphalt from an asphalt feedstock comprising the following steps:

• blowing the asphalt feedstock with a high level of blowing catalyst such that the blowing step is effective to raise the softening point of the asphalt to within a target range of from about 190° F. (88° C.) to about 235° F. (113° C.) and to lower the penetration of the asphalt to within a target range of from about 15 dmm to about 28 dmm at 77° F. (25° C.), the blowing step raising the melt viscosity of the asphalt to higher than a target range;
• and
• adding wax to the blown asphalt after said blowing step to lower its melt viscosity to within the target range of from about 130 cps to about 420 cps at 400° F. (204° C.);
• and
• blending a polymer modified asphalt with the blown asphalt.