Anti-slip roofing underlayment
View Patent ↗A roofing underlayment comprises a reinforcing layer, which is extrusion coated on at least one side with an anti-slip coating layer. The reinforcing layer comprises a woven polyethylene or polypropylene scrim. The anti-slip coating layer comprises a compound based on a styrene and ethylene/butylene-styrene, S-E/B-S, block copolymer, such as the compound sold under the trademark KRATON® MD6649. The anti-slip coating layer may also be embossed. The anti-slip coating layer is low in cost and helps prevent water from penetrating the primary roofing material. In addition, the anti-slip coating layer provides an improved anti-skid surface upon which an individual may safely walk. Embossment improves the wet slip resistance of the roofing underlayment.
1. A roofing underlayment comprising:
a reinforcing layer comprising:
an upper surface anti-slip coating layer comprising:
a core layer comprising 2% UV stabilizer, 10% Beige pigment, 4% anti-block, 20% low density polyethylene, and 64% h-homopolymer polypropylene; and
a skin layer comprising 2% UV stabilizer, 10% Beige pigment, 8% anti-block, 15% low density polyethylene, and 65% S-E/B-S block copolymer compound comprising about 30%-75% by weight styrene-ethylene/butylene-styrene, about 0%-50% by weight resin, and about 0.1-2% by weight antioxidant/stabilizer/dusting agent; and
a lower surface anti-slip coating layer;
wherein the anti-slip coating comprises a styrene and ethylene/butylene-styrene (S-E/B-S) block copolymer, wherein the upper surface anti-slip coating layer has a thickness of about 0.5 mils to 4 mils,
wherein the lower surface anti-slip coating layer has a thickness of about 0.5 mils to 4 mils, and
wherein the roofing underlayment is embossed with a pattern.
2. The roofing underlayment according to claim 1 , wherein the reinforcing layer comprises a woven polyethylene scrim.
3. The roofing underlayment according to claim 1 , wherein the reinforcing layer comprises a woven polypropylene scrim.
4. The roofing underlayment according to claim 1 , wherein the reinforcing layer comprises a nonwoven layer.
5. The roofing underlayment according claim 1 , wherein:
the reinforcing layer comprises a woven polypropylene scrim;
the lower coating layer comprises 73.5% thermoplastic olefin resin, 8.0% low density polyethylene, 2% U.V. stabilizer, 10.5% White MasterBatch, and 6% anti-block; and
wherein the core layer and the skin layer are coextruded onto the scrim; and wherein the core layer comprises 70% by weight of the upper coating layer and the skin layer comprises 30% by weight of the upper coating layer.
6. The roofing underlayment according to claim 1 , wherein the embossment is a diamond pattern.
7. The roofing underlayment according to claim 6 , wherein the diamond pattern comprises interlocking diamond shapes.
8. The roofing underlayment according to claim 1 , wherein embossment is provided by applying heat and pressure while the roofing underlayment is run through a nip assembly.
9. The roofing underlayment according to claim 8 , wherein the nip assembly contains a positive of a pattern to be embossed on the anti-slip coating layer.
10. The roofing underlayment according to claim 1 , wherein the embossment is applied by extrusion coating onto a patterned chill roll.
11. The roofing underlayment according to claim 1 , wherein the embossment is applied by direct embossment.
12. The roofing underlayment according to claim 11 , wherein the direct embossment is carried out after a smooth chill rolling.
13. A roofing underlayment comprising:
a reinforcing layer comprising:
an upper surface anti-slip coating layer comprising:
a core layer; and
a skin layer; and
a lower surface anti-slip coating layer;
and wherein the reinforcing layer comprises a woven polypropylene scrim;
the core layer comprising 1% U.V. stabilizer, 10% Beige pigment, 8% low density polyethylene, and 81% homo-polymer polypropylene;
and wherein the skin coating layer comprises 2% UV stabilizer, 10% Beige pigment, 8% anti-block, 10% homo-polymer polypropylene, and 70% S-E/B-S block copolymer compound comprising about 30-75% by weight styrene-ethylene/butylene-styrene, about 0%-50% by weight resin, and about 0.1%-2% by weight antioxidant/stabilizer/dusting agent;
and wherein the lower coating layer comprises 73.5% thermoplastic olefin resin, 8.0% low density polyethylene, 2% UV stabilizer, 10.5% white masterbatch, and 6% anti-block;
wherein the core layer and the skin layer are coextruded onto the scrim, and wherein the core layer comprises 70% by weight of the upper coating layer and the skin layer comprises 30% by weight of the upper coating layer.