WATERPROOF MEMBRANES

Abstract

Waterproof membranes have a single-ply polymer coated substrate and at least one adhesive layer for architectural and structural waterproofing.

Description

FIELD OF THE INVENTION

The present disclosure and related inventions is directed to an improved waterproof membrane(s) for use as waterproof barriers.

BACKGROUND OF THE INVENTION

Waterproof membranes are commonly formed by use of multiple layers of materials including a matrix such as a woven scrim or fabric which is coated or combined with natural or synthetic material which blocks the passage of moisture through the matrix. For example, roofing membranes, for flat or low-slope roofs are typically constructed of multiple layers of woven polymeric or glass mat material with bituminous or modified bituminous applied to both sides and adhesive between the layers. The modified bituminous material may include any of various polymers or plastics such as atactic polypropylene (APP), amorphous poly-alpha-olefin (APAO), thermoplastic polyolefin (TPO), styrene-butadiene-styrene (SBS), synthetic rubber or other asphaltic modifiers to enhance the adhesive strength and waterproofing performance of the asphalt. Multiple layers of sheet material are used to enhance structural integrity and water resistance. With polymeric materials, incompatibility with bituminous bonding is also countered by use of additional layers and coatings. Such laminates are applied to a roof by use of asphalt adhesive which is applied in a heated condition. This requires the application of hot asphalt directly to a roof underlayment, which is laborious and hazardous. The combination of woven materials and bituminous compositions is problematic in that once the asphalt component degrades, passages through the membrane allow leakage.

Waterproof membranes which have a base fabric or matrix which is coated on both sides with a polymeric material to form a non-permeable barrier are used in various construction and architectural applications. These types of membranes are generally designed for direct installation, not in combination with any other layers or materials to provide a waterproof barrier.

SUMMARY OF THE INVENTION

In one embodiment the present invention discloses a waterproof membrane comprising a waterproof barrier substrate having a base fabric of woven, knitted or non-woven polymeric or glass fibers, a polymeric adhesive coating, and a polymeric coating on both sides of the base fabric, and at least one additional adhesive applied to at least one side of the substrate.

In yet another embodiment the present invention discloses a waterproof membrane comprising a waterproof barrier substrate having a base fabric of woven, knitted or non-woven polymeric or glass fibers, a polymeric adhesive coating, and a polymeric coating on one side of the base fabric, and at least one additional adhesive applied to an un-coated side of the base fabric.

In still yet another embodiment the present invention discloses a single-ply waterproof and structural barrier substrate for a roofing membrane, comprising a polymeric adhesive and polymeric coating compound applied to at least one side of a base fabric, the base fabric having an uncoated underside for contact with an adhesive for bonding to a roof surface.

The present disclosure and related inventions includes improved substrates for waterproof membranes, and more specifically single-ply polymer coated substrates which are designed for installation in combination with one or more adhesives applied to one or both sides of the substrate. The single-ply waterproof membranes of the present disclosure can be used in any architectural or construction application, including for example installation with any structure whether above or below ground such as roofing including flat and sloped roofs, siding underlayment, below grade water proofing such as for foundations and basements, excavation lining, decks, or adjacent to or incorporated into any concrete structure. The single-ply waterproof membranes of the present disclosure may also be used as one of the layers in a multiple layer waterproofing system or laminate, or as a cap layer over asphalt in a multiple layer waterproofing system to improve resistance to degradation from exposure to UV radiation, weather or chemicals.

In one particular embodiment of a roofing application of the invention, a single-ply waterproof and structural barrier substrate for any architectural or construction application includes a base fabric which may be knitted, woven or non-woven or polymeric (e.g. polyester) or glass mat fibers, a polymeric adhesive coating and a polymeric coating (e.g. plasticized PVC compound, PVC/Elvaloy, or any other suitable polymeric coating) on each side of the base fabric, such as a heat-fusible thermoplastic. The polymeric coating is selected for optimal bonding with an adhesive, which may be asphalt, polyurethane, latex or rubber containing adhesive which bonds with the polymeric coating applied to the underside of the base fabric. The superior waterproof barrier and structural strength of the single layer polymeric substrate in combination with an adhesive provides an improved waterproofing membrane which can be installed without heat or any additional sealants or components. Ideally, the polymeric coating of the base fabric is comprised so a specially formulated compound which is highly compatible with additional adhesives.

In a further preferred embodiment of a single-ply waterproof and structural barrier substrate for a waterproof membrane such as a roofing membrane, a polymeric adhesive and polymeric coating compound is applied only to a top side of the base fabric. This embodiment is referred to herein as a single-side coated single-ply waterproof membrane. An underside of the base fabric is left exposed for direct contact with an asphalt or other adhesive for bonding directly to a roof surface. Additional adhesive can be applied to a top side of the substrate for bonding of an additional layer. A release paper may be applied to the adhesive on an underside of the substrate.

In another embodiment, a polyester base fabric of increased mass of for example 6 to 10 ounces/sq. yard, is used as the single-ply base fabric for improved puncture resistance and waterproofing and ability to carry polymeric adhesive and polymeric coating layers on a single side such as the top side, and to carry asphalt binding layers on both sides.

In another embodiment, a single-ply base fabric is coated on one side with a compound that is specifically formulated to resist any further adhesive that is applied to it. An example is the use of a PVC/Elvaloy compound, formulated to resist degradation from exposure to any additional adhesive applied to the polymer coating, and extended long-term performance. In this embodiment also, the mass or density of the base fabric may also be increased for the stated advantages.

In another embodiment, a single-ply waterproofing membrane has a single-ply waterproof and structural barrier substrate base fabric which is coated with a polymeric adhesive and polymeric coating on only a top, exposed, upward side. A bottom uncoated side of the base fabric is adhered, for example by any compatible adhesive. For example, in a roofing application, an asphalt-based adhesive can be used to apply the membrane to a roof surface. The uncoated base fabric provides improved an adhesion surface for the asphalt adhesive, without compromise of the waterproof and mechanical barrier properties of the roofing membrane substrate.

In another embodiment, air-textured yarns such as air-textured polyester yarns are used in the base fabric of the substrate, and can be left uncoated on an underside as described. The use of air-textured yarns provides an optimal surface for adhesion of asphalt or other material as an adhesive for a waterproof membrane. A base fabric substrate which contains air-textured yarns may be woven or non-woven or knitted. In a knitted base fabric the air-textured yarns are preferably on a bottom and un-coated exposed side of the fabric for improved adhesion with an asphalt adhesive. In another embodiment, the barrier substrate is comprised of texturized polymeric yarns.

In yet another embodiment, a roofing membrane has a substrate which includes a fabric, such as a woven fabric of polyester yarn, which is un-coated on a bottom side and coated on a top side with a polymeric adhesive and a polymeric coating, and a non-woven fiber mat attached to the top side. Roofing granules are adhered to the non-woven fiber mat, for example by asphalt.

In still yet another embodiment, one or more release covers are employed to one or both sides of the membrane, structure or substrate to protect the materials underneath prior to application or to preserve the material properties (including adhesive properties) prior to application or use.

These and other alternate embodiments and variations thereof are further described herein.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic rendering of a representative embodiment of a waterproof membrane of the present disclosure; and

FIG. 2 is a schematic rendering of a representative embodiment of a waterproof roofing membrane of the present disclosure.

DETAILED DESCRIPTION OF PREFERRED AND ALTERNATE EMBODIMENTS

The present disclosure and related inventions are directed to waterproof membranes and particularly to single-ply polymeric coated substrates which serve as the primary water barrier in a waterproof membrane. The single-ply polymeric coated substrates of the present disclosure and related inventions are combinable with one or more adhesives and additional materials to form a waterproof membrane for a wide variety of applications, including architectural and construction applications above and below grade and adjacent any surface or structure to be protected from moisture.

The present disclosure and related inventions also include improved substrates which serve as the waterproof barrier and structural puncture-resistant barrier for a single-layer roofing membrane. The waterproof membranes of the present disclosure, made with a single-ply polymer coated substrate as described herein, provide reduced weight and/or thickness; reduced cost; improved puncture resistance; improved degradation resistance or long-term performance; improved weather resistance; improved adhesion qualities; and improved cosmetic qualities over waterproof barriers of the prior art.

Referring to FIG. 1, a waterproof membrane shown in cross-section and indicated generally at 1, can be made with any of the various embodiments of the single-ply polymeric coated substrates disclosed herein. The waterproof membrane 1 has a single-ply substrate that includes a woven, knitted or non-woven base fabric 14 made from yarns 141, 142, which may be polyester yarn, preferably of continuous strand polyester fibers (or in some embodiments known as high tenacity continuous filament polyester fibers). Alternatively, the fabric may be made from any suitable polymeric or glass fiber(s). A polymeric adhesive 16 is applied to a first or upper side 14A of the base fabric 14, and a polymeric coating 18 is applied over the polymeric adhesive layer 16. In some embodiments, the polymeric adhesive layer 16 and polymeric coating layer 18 may be symmetrically applied to an underside 14B of the base fabric 14 as further described. In this particular embodiment, the underside 14B of base fabric 14 is not coated. The yarns 141, 142 of the base fabric 14 are exposed directly to and bonded with an adhesive 2 which is the adherent for attachment of the membrane 1 to any surface 100 as a single-ply waterproofing membrane. Leaving the side 14B of the base fabric 14 uncoated reduces the weight, thickness and cost of the membrane 1 and improves adhesion as the bare polyester yarns contact directly with the adhesive. As noted the adhesive may be asphaltic, polyurethane, rubber or latex based as may be selected for any particular application. The polymeric coating 18 is preferably selected for compatibility and strong bonding with any particular adhesive 2. Such adhesive(s) 2 include, but are not limited to, pressure sensitive adhesives such as acrylic based adhesives, butyl rubber based adhesives, ethylene vinyl acetate adhesives or any other suitable adhesives. In one embodiment, adhesive 2 may require the use of an optional release layer. In yet another embodiment, adhesive 2 being able to adhere to itself, such adherence typically not a major handling issue. In still yet another embodiment, adhesive 2 acting as a means for waterproof membrane 1 to be applied in a “peel and stick” type application, in such an application a release cover optionally being employed. The coatings 16 and 18 on the top side 14A of base fabric 14, and the strength and mass of the base fabric 14 create the strong waterproof and puncture-resistant barrier properties of the membrane 1. Additional layers, shown for example as layers 3 and 4, can be added to the membrane 1 for additional performance enhancements. In one embodiment, additional layers 3 and 4 being adhesive in nature. In another embodiment, examples of layers 3 and 4 including, but not limited to, pressure sensitive adhesives such as acrylic based adhesives, butyl rubber based adhesives, ethylene vinyl acetate adhesives or any other suitable adhesives, UV barriers such as a Tedlar film, or any other applicable materials which enhance the properties of the membrane. Also, the membrane 1 may be used in any location in a laminate or build-up of layers as a structural and moisture, water or chemical barrier.

As shown in FIG. 2, a waterproof roofing membrane in cross-section is indicated generally at 10, which can be made with any of the various embodiments of the single-ply polymeric coated substrates disclosed herein. The roofing membrane has a single-ply substrate 12 that includes a woven base fabric 14 made from interwoven, non-woven or knitted yarns 141, 142, which may be polyester yarn. Alternatively, the fabric may be made from any suitable polymeric or glass fiber(s). A polymeric adhesive 16 is applied to a first or upper side 14A of the base fabric 14, and a polymeric coating 18 is applied over the polymeric adhesive layer 16. In some embodiments, the polymeric adhesive layer 16 and polymeric coating layer 18 may be symmetrically applied to an underside 14B of the base fabric 14 as further described. In this particular embodiment, the underside 14B of base fabric 14 is not coated. The yarns 141, 142 of the base fabric 14 are exposed directly to and bonded with asphalt adhesive 24 (which may be covered by a release cover 26). The asphalt (or asphalt based) adhesive 24 is the adherent for attachment of the roofing membrane 10 to a surface of a roof 200. Leaving the side 14B of the base fabric 14 uncoated reduces the weight, thickness and cost of the membrane 10 and improves asphalt adhesion as the bare polyester yarns contact directly with the asphaltic adhesive. The coatings 16 and 18 on the top side 14A of base fabric 14 create a strong waterproof and puncture-resistant barrier.

For an architectural roofing product, an upper asphalt layer 22 can be applied directly to a top upper surface of the polymeric coating layer 18, and granules 28 attached to and embedded in the asphalt layer 22, to provide the primary exposed surface of the roofing membrane 10. Alternatively, a fiber containing material, such as for example a non-woven mat 20 made of polyester fibers can be fused to the polymeric coating 18 of the substrate 12, and asphalt layer 22 applied thereto. The fibers of the layer 20 provide a textured multi-dimensional surface which optimizes adhesion with asphalt for the exposed surface of the membrane 10.

In an alternate embodiment, the base fabric 14 may include strands of textured polyester yarns. Air textured yarn is a yarn that has been processed to introduce durable crimps, coils, loops or other fine distortions along the length of the fibers, thereby altering the surface texture and topography of the fabric. The texturing process may include one or more of the following processes: twisting the yarn, heat-setting and then untwisting; passing the yarn through a heated “stuffer box”; passing the heating yarn over a knife edge; passing the heated yarn between a pair of geared wheels or some similar device; and kitting the yarn into a fabric, heat-setting, then unraveling the yarn. The use of air textured yarn in the base fabric 14 of the substrate 12 improves adhesion of asphalt adhesion to the underside 14B of the substrate and adhesion of the entire membrane 10 to a roof.

In another aspect of the disclosure, a heavier polyester yarn is used to form the base fabric 14 to increase the thickness and overall mass of the fabric 14. This increases the coating carrying capacity of the fabric 14 for improved waterproofing and puncture resistance, and ability to carrying the top coating of asphalt and granules as described for increased UV resistance and longevity. For example, the fiber weight, diameter and strength and density of the weave can be increased beyond that of fabrics conventionally used in waterproof membranes of the prior art for the new application of a single ply asphaltic roofing membrane of the present disclosure.

The polymeric coating, such as coating layer 18 can also be augmented or modified in accordance with the disclosure for the described combination with the top asphalt and granule coating. A preferred material for coating layer 18 is a PVC alloy compound such as for example DuPont™ Elvaloy® ketone ethylene ester resin is used in addition to PVC in the substrate layer 18 coating compound. DuPont™ Elvaloy® is differs from conventional plasticizers in that it is a solid pellet, which when blended with another solid makes the entire mixture flexible. Because it is a solid, it cannot migrate out of the sheet. Since it does not migrate and cannot be extracted, it stays flexible. The use of this type of compound in the substrate coating layer 18 has improved resistance to degradation from exposure to hot asphalt, providing better long-term performance of the entire roofing membrane 10.

The various embodiments of the present invention described above may be combined together in any number and/or combination.

Claims

1. A waterproof membrane comprising: a waterproof barrier substrate having a base fabric of woven, knitted or non-woven polymeric or glass fibers;a polymeric adhesive coating; anda polymeric coating on both sides of the base fabric, and at least one additional adhesive applied to at least one side of the substrate.

2. The waterproof membrane of claim 1 wherein the base fabric of the waterproof barrier substrate is comprised of woven, knitted, or non-woven polyester or glass fiber fabric having a weight of approximately 6 to 10 ounces per square yard.

3. The waterproof membrane of claim 1 wherein the polymeric coating is comprised of a specially formulated compound that is highly compatible with additional adhesives.

4. The waterproof membrane of claim 1 further comprising one or more release covers adjacent to the at least one additional adhesive.

5. The waterproof membrane of claim 1 further comprising at least one additional layer of material on a top side of the waterproof membrane.

6. The waterproof membrane of claim 5 wherein the at least one additional layer of material on the top side of the waterproof membrane is an adhesive.

7. The waterproof membrane of claim 6 further comprising one or more release covers adjacent to the adhesive.

8. A waterproof membrane comprising: a waterproof barrier substrate having a base fabric of woven, knitted or non-woven polymeric or glass fibers;a polymeric adhesive coating; anda polymeric coating on one side of the base fabric, and at least one additional adhesive applied to an un-coated side of the base fabric.

9. The waterproof membrane of claim 8 wherein the base fabric of the waterproof barrier substrate is comprised of woven, knitted, or non-woven polyester or glass fiber fabric having a weight of approximately 6 to 10 ounces per square yard.

10. The waterproof membrane of claim 8 wherein the base fabric of the waterproof barrier substrate is comprised of texturized polymeric yarns.

11. The waterproof membrane of claim 8 wherein the polymeric coating is comprised of a specially formulated compound that is highly compatible with additional adhesives.

12. The waterproof membrane of claim 8 further comprising one or more release covers adjacent to the at least one additional adhesive applied to an un-coated side of the base fabric.

13. The waterproof membrane of claim 8 further comprising at least one additional layer of material on a top side of the waterproof membrane.

14. The waterproof membrane of claim 13 wherein the at least one additional layer of material on the top side of the waterproof membrane is an adhesive.

15. The waterproof membrane of claim 14 further comprising one or more release covers adjacent to the adhesive.

16. A single-ply waterproof and structural barrier substrate for a roofing membrane, comprising a polymeric adhesive and polymeric coating compound applied to at least one side of a base fabric, the base fabric having an uncoated underside for contact with an adhesive for bonding to a roof surface.

17. The single ply waterproof and structural barrier substrate of claim 16 in combination with an asphalt-containing adhesive and granules applied to a top side of the substrate.

18. The single ply waterproof and structural barrier substrate of claim 16 in combination with a non-woven polymeric fiber layer applied to the top side of the substrate and an asphalt-containing adhesive, and granules applied to the top side of the substrate.

19. The single ply waterproof and structural barrier substrate of claim 16 further comprising one or more release covers adjacent to the polymeric adhesive and polymeric coating compound.

20. The single ply waterproof and structural barrier substrate of claim 16 further comprising one or more release covers adjacent to the base fabric having an uncoated underside.