Roofing Membranes, Compositions, and Methods Of Making The Same
A roofing membrane includes (A) about 40 to 75 wt. % silane-crosslinked polyolefin elastomer/plastomer component including a blend of at least three different polyolefin elastomers, each having different melt mass-flow rate (MFR), measured at 190° C. under a 2.16 kg load, in a range of about 3.0 to 25.0 g/10 min, (E) about 1 to 20 wt. % functional filler(s) including a polyolefin; (F) UV/heat stabilizer(s); (G) antioxidant(s); and (H) fire retardant(s), wt. % based on the total weight of the roofing membrane.
1 . A roofing membrane comprising:
(A) about 40 to 75 wt. % silane-crosslinked polyolefin elastomer/plastomer component including a blend of at least three different polyolefin elastomers, each having different melt mass-flow rate (MFR), measured at 190° C. under a 2.16 kg load, in a range of about 3.0 to 25.0 g/10 min,
(E) about 1 to 20 wt. % functional filler(s) including a polyolefin;
(F) UV/heat stabilizer(s);
(G) antioxidant(s); and
(H) fire retardant(s),
wt. % based on the total weight of the roofing membrane.
2 . The roofing membrane of claim 1 , wherein the blend of the at least three different polyolefin elastomers includes a first polyolefin, a second polyolefin, and a third polyolefin in a ratio of first polyolefin:second polyolefin:third polyolefin of about 16.2:1:2.
3 . The roofing membrane of claim 1 , wherein the blend of the at least three different polyolefin elastomers includes two different ethylene-octene copolymers.
4 . The roofing membrane of claim 1 , wherein the component A includes different amounts of each one of the at least three different polyolefin elastomers.
5 . The roofing membrane of claim 1 , wherein the component (E) comprises polypropylene having MFR in the same range as the polyolefin elastomers of the component (A).
6 . The roofing membrane of claim 1 , wherein the membrane exhibits a glass transition temperature of from about −75° C. to about −25° C., measured according to differential scanning calorimetry (DSC) using a second heating run at a rate of 5° C./min or 10° C./min.
7 . The roofing membrane of claim 1 , wherein the membrane exhibits low temperature retraction in a range of about −35 to −29% at TR10, measured according to ISO 2921.
8 . A roofing membrane comprising:
a top layer having a thickness t 1 and including:
a first (A) silane-crosslinked polyolefin elastomer/plastomer component including a first blend of at least three polyolefin elastomers, each having different melt mass-flow rate (MFR), measured at 190° C. under a 2.16 kg load, and
a bottom layer having a thickness t 2 and including:
a second (A) silane-crosslinked polyolefin elastomer/plastomer component including a second blend of polyolefin elastomers,
the thickness t 2 being greater than the thickness t 1 .
9 . The roofing membrane of claim 8 , wherein at least one of the second blend of polyolefin elastomers is the same elastomer as in the first blend.
10 . The roofing membrane of claim 8 , wherein a ratio of the first silane-crosslinked polyolefin elastomer/plastomer second silane-crosslinked polyolefin elastomer/plastomer is about 19:1 to 2:1.
11 . The roofing membrane of claim 8 , wherein the top layer further comprises (F) UV/heat stabilizer(s) and both the top and bottom layers further comprise (G) antioxidant(s) and (H) fire retardant(s).
12 . The roofing membrane of claim 8 , wherein the top layer further includes titanium dioxide, and the bottom layer is titanium dioxide-free.
13 . The roofing membrane of claim 8 , wherein the first and second silane-crosslinked polyolefin elastomer/plastomer components include a same polyolefin, the polyolefin being present in a lower weight percentage in the bottom layer than in the top layer.
14 . The roofing membrane of claim 8 , wherein the first blend includes a first polyolefin, a second polyolefin, and a third polyolefin in a ratio of first polyolefin:second polyolefin:third polyolefin of about 16.2:1:2.
15 . The roofing membrane of claim 8 , wherein the top layer has a gel content greater than about 70% and the bottom layer may have a gel content between about 50 and 70%.
16 . A roofing membrane comprising:
a single-ply layer including:
a silane-crosslinked polyolefin elastomer/plastomer component comprising a blend of ethylene-1-butene copolymer, ethylene propylene copolymer, and ethylene octene copolymer; and
one or more UV/heat stabilizer(s), antioxidant(s), and fire retardant(s),
the single-ply layer having elongation at break, measured according to ASTM D412, Die C, of about 600 to 930% and heat ageing elongation at break, measured according to the ASTM D573, of about 350 to 700%.
17 . The roofing membrane of claim 16 , wherein a ratio of the ethylene-1-butene copolymer:ethylene propylene copolymer:ethylene octene copolymer is about 5.4:1:2.
18 . The roofing membrane of claim 16 , wherein the component (A) includes different amounts of the ethylene-1-butene copolymer, ethylene propylene copolymer, and ethylene octene copolymer.
19 . The roofing membrane of claim 16 , wherein the single-ply layer further comprises polypropylene having MFR in the same range as at least one of the ethylene-1-butene copolymer:ethylene propylene copolymer:ethylene octene copolymer.
20 . The roofing membrane of claim 16 , wherein the roofing membrane has tensile elongation at break, measured according to ASTM D412, Die C testing method, of about 600 to 930%.