CPC B32B 27/12 (2013.01) [B32B 5/022 (2013.01); B32B 7/12 (2013.01); B32B 27/20 (2013.01); B32B 27/32 (2013.01); B32B 27/34 (2013.01); E04D 12/002 (2013.01); B32B 2250/03 (2013.01); B32B 2262/0253 (2013.01); B32B 2264/0214 (2013.01); B32B 2264/104 (2013.01); B32B 2264/1021 (2020.08); B32B 2264/1023 (2020.08); B32B 2307/718 (2013.01); B32B 2307/724 (2013.01); B32B 2307/728 (2013.01); B32B 2307/7265 (2013.01); B32B 2307/73 (2013.01); B32B 2307/732 (2013.01); B32B 2419/06 (2013.01)] | 34 Claims |
1. A roofing underlayment comprising:
(a) a first layer that is nonwoven, vapour-permeable, and has a hydrophobic surface, comprising a polymer or mixture of polymers, the first layer being an outer layer configured to contact an exterior roofing material;
(b) a second layer that is water vapour-permeable and a liquid water barrier, comprising a carrier resin and a breathability agent, and
(c) a third layer configured to contact a roofing deck, the third layer being nonwoven, hydrophilic and liquid water absorptive,
wherein the second layer between the third layer and the first layer;
wherein the third layer comprises a carrier resin and a hydrophilic agent;
wherein the carrier resin comprises a polyolefin;
wherein the hydrophilic agent comprises between 2 and 10 weight % of the third layer;
wherein the roofing underlayment has a water absorbency of at least 9 g/m2 in 10 minutes; and
wherein the roofing underlayment has a breathability of at least 10 perms when measured in accordance with standard test method ASTM E96; and
wherein the roofing underlayment has a surface wettability on its bottom surface such that a contact angle between the bottom surface and water decreases to 0° in less than 6 seconds, measured in accordance with standard test method ASTM D724.
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