Self-adhered modified bitumen roofing material

A dual-compound roof covering comprising:

• a composite having a carrier sheet with a front side and a back side, the carrier sheet being sandwiched between:
• a first top layer comprised of a mixture of:
• (a) 5% to 25% polypropylene modifiers comprised of isotactic polypropylene, ethylene-propylene copolymer, atactic polypropylene and polyethylene, (b) 8% to 70% of filler, and (c) 45% to 75% bitumen;
• a second bottom layer of heat-and-pressure activated self-adhesive compound comprised of a mixture of:
• (a) 3% to 10% styrene-butadiene-styrene copolymer, (b) 4% to 11% styrene-isoprene-styrene copolymer, (c) 20% to 33% hydrocarbon tackifying resins, (d) 0% mineral stabilizers, and (e) remainder asphalt;
• and
• the top and bottom layers forming oppositely exposed upper and lower surfaces.

A dual-compound roof covering comprising:

• a composite having a carrier sheet with a front side and a back side, the carrier sheet being sandwiched between:
• a first top layer comprised of a mixture of:
• (a) polypropylene modifiers comprised of isotactic polypropylene, ethylene-propylene copolymer, atactic polypropylene and polyethylene, (b) filler, and (c) asphalt;
• a second bottom layer of heat-and-pressure activated self-adhesive compound comprised of a mixture of:
• (a) styrene-butadiene-styrene copolymer, (b) styrene-isoprene-styrene copolymer, (c) hydrocarbon tackifying resins, (d) mineral stabilizers, and (e) asphalt;
• and
• the top and bottom layers forming oppositely exposed upper and lower surfaces.
• the hydrocarbon tackifying resins in the bottom layer compound is primarily Polyvinyl Butyral.

A dual-compound roof covering comprising:

• a composite having a carrier sheet with a front side and a back side, the carrier sheet being sandwiched between:
• a first top layer comprised of a mixture of:
• (a) 5% to 25% polypropylene modifiers comprised of isotactic polypropylene, ethylene-propylene copolymer, atactic polypropylene and polyethylene, (b) 8% to 70% of filler, and (c) 45% to 75% bitumen;
• a second bottom layer of heat-and-pressure activated self-adhesive compound comprised of a mixture of:
• (a) 3% to 10% styrene-butadiene-styrene copolymer, (b) 0% to 5% styrene-isoprene-styrene copolymer, (c) 6% to 25% hydrocarbon tackifying resins, (d) 8% to 40% mineral stabilizers, and (e) remainder asphalt;
• and
• the top and bottom layers forming oppositely exposed upper and lower surfaces.
• the hydrocarbon tackifying resins in the bottom layer compound is primarily Polyvinyl Butyral.

A dual-compound roof covering comprising:

• a composite having a carrier sheet with a front side and a back side, the carrier sheet being sandwiched between:
• a first top layer comprised of a mixture of:
• (a) polypropylene modifiers comprised of isotactic polypropylene, ethylene-propylene copolymer, atactic polypropylene and polyethylene, (b) filler, and (c) asphalt;
• a second bottom layer of heat-and-pressure activated self-adhesive compound comprised of a mixture of:
• (a) 3% to 10% styrene-butadiene-styrene copolymer, (b) 0% to 5% styrene-isoprene-styrene copolymer, (c6% to 25% hydrocarbon tackifying resins, (d) 8% to 40% mineral stabilizers/filler, and (e) remainder asphalt;
• the top and bottom layers forming oppositely exposed upper and lower surfaces;
• and
• the hydrocarbon tackifying resins in the bottom layer compound is primarily Polyvinyl Butyral.