US Patent 10443190 Fire resistant composite roofing membrane

A composite roofing membrane containing a single ply roofing membrane containing a first membrane, a scrim, and a second membrane. The first side of the first membrane forms the upper surface of the composite roofing membrane and contains a thermoplastic polymer. The scrim has a machine and cross-machine direction and contains a yarn or fiber selected from the group consisting of polyester and glass, and a tensile strength in the machine direction is at least about 100 N/cm2. The second membrane contains a thermoplastic polymer. The composite roofing membrane also contains a fire resistant fleece containing a plurality of FR rayon staple fibers and a plurality of char scaffold fibers selected from the group consisting of partially oxidized acrylonitrile and silica staple fibers.