Patent ID: 7115313

Claim:
A self-adhering underlayment for metal roofing assemblies comprising: a dual-compound composite sheet having a carrier sheet with a front side and a back side, the carrier sheet being sandwiched between a top layer and a bottom layer: the 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; the bottom layer comprised 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, and (d) asphalt; and the top and bottom layers forming oppositely facing upper and lower surfaces.