Laminate of heat sealable polyolefin and cured polyolefin sheeting
AssigneeMinnesota Mining and Manufacturing Company
InventorDennis L. Levens
Life of this patent
Estimating the term…
Abstract
A laminate formed by heat fusing a heat sealable polyolefin sheet to two cured polyolefin sheets to produce a water impermeable seal between the cured polyolefin sheets. The heat sealable polyolefin sheet is preferably bonded to a porous heat resistant backing on one surface and the other surface is heat fused to the cured polyolefin sheets. The cured polyolefin sheets may typically be in juxtaposed or overlapping arrangement. The porous backing may be in the form of a fibrous sheet. The heat sealable polyolefin sheet is preferably low density polyethylene and the cured polyolefin sheets are typically cured EPDM rubber.
Claims26
A laminate comprising two cured polyolefin sheets and a carbon black containing heat sealable polyolefin sheet wherein the cured polyolefin sheets have a seam therebetween and the heat sealable polyolefin sheet covers said seam and is fused to each of said cured polyolefin sheets to produce a substantially water impermeable seal between said cured sheets, said heat sealable polyolefin sheet having a first major surface and opposite second major surface, said first major surface bonded to a porous backing and the second major surface being fused to said cured polyolefin sheets, the presence of carbon black in said heat sealable polyolefin sheet improves its weatherability and the absorbance of radiation heat by said heat sealable polyolefin sheet.
A flexible laminate comprising a carbon black containing heat sealable polyolefin layer bonded to a porous backing and fused to two cured polyolefin sheet to produce a substantially water impermeable seal at the seam between said two cured polyolefin sheet wherein said porous backing has a melting temperature higher than the melting temperature of the heat sealable polyolefin layer, the presence of carbon black in said heat sealable polyolefin sheet improves its weatherability and the absorbance of radiation heat by said heat sealable polyolefin sheet.
A composite structure comprising:
- (a) two cured polyolefin sheets in proximity to each other having a seam there between;
- and
- (b) a sealing tape comprising a porous backing having a layer of heat sealable polyolefin bonded thereto, wherein said sealing tape covers said seam and is fused to each of said polyolefin sheets through said heat sealable polyolefin layer to produce a substantially water impermeable seal between said cured sheets and further wherein said heat sealable polyolefin comprises carbon black, the presence of carbon black in said heat sealable polyolefin sheet improves its weatherability and the absorbance of radiation heat by said heat sealable polyolefin sheet.
A flexible roofing membrane comprising first and second cured, flexible polyolefin sheets having a seam therebetween, a sealing tape over said seam and fused to each of said sheets to produce a substantially water impermeable seal between said cured sheets, wherein said tape comprises a porous backing having a layer of carbon black containing heat sealable polyolefin therein, which heat sealable polyolefin contacts said cured sheets and is fused thereto, the presence of carbon black in said heat sealable polyolefin sheet improves its weatherability and the absorbance of radiation heat by said heat sealable polyolefin sheet.
Dependencies are inferred from the claim text.