Roofing product including bio-based asphalt mixture and methods of making the roofing product and the roofing-grade asphalt mixture

A roofing grade asphalt mixture consisting of:

• a bio-asphalt, at least one bitumen source material, particles, and an optional plasticizer;
• wherein the bio-asphalt is an esterification or transesterification alkyd resin reaction product of a bio-source material in the presence of a polycarboxylic acid modifier;
• wherein the polycarboxylic acid consists of a phthalic acid, an isophthalic acid, a terephthalic acid, a tetrahydrophthalic acid, a naphthalene dicarboxylic acid, or any combination thereof;
• wherein the at least one bitumen source material is different than the bio-asphalt, the at least one bitumen source material consisting of a first bitumen source material, a second bitumen source material, or combination thereof selected from the group consisting of petroleum-based asphalt, coal tar, or combination thereof;
• and
• wherein the roofing grade asphalt mixture has a softening point of at least 104° C., a penetration distance of no greater than 12 dmm, and a viscosity of at least 3000 cps at a temperature of 177° C.