Patent ID: 7799406

Claim:
A single-ply roofing membrane, comprising a thermoplastic polyolefin-based mixture that includes: a thermoplastic polyolefin blend consisting of a first polypropylene-ethylene elastomer having a first ethylene co-polymer in an amount of 15 percent by weight of said first elastomer and a second polypropylene-ethylene elastomer having a second ethylene co-polymer in an amount of 12 percent by weight of said second elastomer, wherein the amount of said first elastomer in said blend is greater than zero parts of said blend and less than 100 parts of said blend and the balance of said blend is said second elastomer; titanium dioxide in an amount in the range of about 5 to about 10 parts per 100 parts of said blend; and calcium carbonate in an amount in the range of greater than 0 to 80 parts per 100 parts of said blend, wherein said roofing membrane consists of a non-reinforced single layer of said thermoplastic polyolefin-based mixture, wherein said roofing membrane is heat-weldable, wherein a sample of said roofing membrane having a thickness of 30 mil has a stretchability that is greater than 14 lbf and less than 30 lbf as measured by the stretchability test, and wherein said roofing membrane has a whiteness of at least an L* value of 90 as measured by the whiteness test.