Patent Publication Number: US-2021178429-A1

Title: Methods Of Sealing Wet Surfaces By Applying Moisture-Cure Hybrid Synthetic Resin Paste

Description:
BACKGROUND 
     A number of products are commercially available for waterproofing doors, windows, siding, and various other structures. Acrylic- and solvent-based products typically require application onto a dry surface in order to provide sufficient adhesion to the surface and resulting waterproofing. However, in some circumstances, damage to a surface may be discovered only upon the presence of water on the surface and, in severe cases, upon significant quantities of water flowing through the damaged area. It would be desirable to develop techniques that allow for repair of wet surfaces, including surfaces from which water is actively flowing. It would be particularly desirable to develop techniques that also allow for the surface to be painted subsequent to the repair. 
     SUMMARY 
     Aspects of the invention involve techniques in which a moisture-cure, hybrid synthetic resin paste (herein sometimes referred to as “paste”) is applied to a wet surface to create a waterproof barrier. The paste may be applied to a wide variety of surfaces, non-limiting examples of which include metal, wood, stucco, plaster, brick, concrete, glass, rubber, tile, fiberglass, ceramic, porcelain, plastic, canvas, stone, and drywall. The paste may be used to repair, patch, bond, seal, and/or waterproof various types of articles, non-limiting examples of which include roofs, gutters, boats, kayaks, personal watercraft, canoes, rafts, outdoor equipment, mobile homes, recreational vehicles, campers, garden hoses, low-pressure PVC and plumbing pipes, tents, vinyl awnings, covers and tarps, above-ground swimming pools, windows, doors, walls, seams, vents, air ducts, HVAC systems, and the like. 
     In one aspect, an aperture is formed in wooden barrel that is at least partially filled with water by cutting through a wall portion thereof, e.g., a side or an end portion of the barrel, using a cutting tool such as a chainsaw. The water that gushes through the aperture may be collected in a reservoir and recirculated into the barrel via a pump to maintain the water in the barrel at a substantially constant level. As the water gushes through the aperture, a quantity of paste is applied to cover the aperture and form a watertight seal, thereby preventing water from continuing to flow through the aperture. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention and certain advantages thereof may be acquired by referring to the following detailed description in consideration with the accompanying drawings, in which: 
         FIGS. 1A and 1B  illustrate a method of repairing a leak in a liquid container such as a wooden barrel or other liquid storage tank. 
         FIGS. 2A and 2B  illustrate a method of repairing a leak in a conduit such as a PVC pipe. 
         FIGS. 3A and 3B  illustrate a method of repairing a leak in a water-containing structure such as an above-ground swimming pool. 
         FIGS. 4A and 4B  illustrate a method of making underwater repairs to a partially submerged vessel. 
     
    
    
     DETAILED DESCRIPTION 
     A moisture-cure, hybrid synthetic resin paste (sometimes referred to herein as “paste”) may be used in a variety of techniques involving repair or waterproofing of various articles such as roofs, gutters, boats, kayaks, personal watercraft, canoes, rafts, outdoor equipment, mobile homes, recreational vehicles, campers, garden hoses, low pressure PVC and plumbing pipes, tents, vinyl awnings, covers and tarps, above-ground swimming pools, windows, doors, walls, seams, vents, air ducts, HVAC systems, and the like. The paste is highly flexible, allowing it to readily conform to the shape of the surface to which it is applied. The paste may form a strong bond with a variety of surfaces under a variety of conditions, particularly in the presence of water. The paste may be applied to a wide variety of surfaces, non-limiting examples of which include metal, wood, stucco, plaster, brick, concrete, glass, rubber, tile, fiberglass, ceramic, plastic, porcelain, canvas, stone, and drywall. 
     In some examples, the paste is applied to a surface that is wet and/or in contact with flowing water, so that leaks may be repaired in articles such as pipes, aquariums, above-ground swimming pools, hot tubs, or inflatable pools, for example, without the need for draining them prior to repair, as well as in doors, windows, or other building structures that may be leaking water during a storm and/or as a result of flooding. The methods described herein also are useful to affect underwater repairs such as repairing leaks in waterborne vessels, docks, or the like. 
     Any suitable application tool may be used to apply the paste. For example, the paste may be supplied in a caulk tube and applied using a caulk gun. In some examples, the paste may be applied with a suitable hand tool such as a spatula. Application of the paste by spatula not only allows for precise control of the quantity of paste applied, but also enables the user to, simultaneous with application, force the paste into crevasses and damaged areas as the paste is applied, further assisting with the formation of a watertight seal. 
     In some examples, a paste is applied to a wet surface for purposes of waterproofing, including repairing holes or leaks in an article, or modifying the article to make it waterproof by covering preformed holes or by adding a moisture-impermeable layer to the article or a portion thereof. The paste may provide a durable, breathable, weatherproof barrier that is resistant to rain, snow, sun, wind, air moisture, UV degradation, and natural weathering over a wide temperature range. The paste may provide additional strength and waterproofing that enable a much wider range of applications than heretofore were possible, particularly applications needing higher adhesive strength and/or when the paste is applied to a surface in the presence of water, including flowing water and even gushing water. A “wet surface,” as used herein, refers to a surface which has retained water due to weather and/or contact with water such as a body of water including flood water, ponds, rivers, lakes, streams, oceans, or the like. For clarity, water that is present merely to a hygroscopic material, such as wood, absorbing moisture from the air does not constitute a “wet” surface. Wet surfaces may be identified by the presence of water being discernible by the naked human eye using only ambient light. 
     The particular composition of the moisture-cure, hybrid synthetic resin paste used is not limited provided that it has sufficiently high adhesive strength and water-resistance characteristics. The paste may have a non-shrink formula. Moisture-cure polyurethanes (PURs) or polyurethane prepolymer are isocyanate-terminated prepolymers that are formulated to cure with ambient water. Cured PURs are segmented copolymer polyurethane-ureas exhibiting microphase-separated morphologies. One phase is derived from a typically flexible (sub-ambient glass transition temperature, TO polyol that is generally referred to as the soft phase. The corresponding hard phase is born from the di- or polyisocyanates that through water reaction produce a highly crosslinked material with softening temperature well above room temperature. 
     Moisture-cure polyurethanes have been widely used in the adhesive and coating industries. Thermal, mechanical, and surface properties of hyperbranched polyurethane-urea (HBPU) moisture cured coatings have been studied in relationship to chemical structure. Different NCO terminated HBPU prepolymers were prepared by reacting hyperbranched polymers with isophorone diisocyanate (IPDI) or 4,4′-bis-methylene cyclohexane diisocyanate (HMDI). A range of NCO/OH eq. ratios from 1.2-1.6 may be used. Thermal and mechanical properties of moisture cured polyurethane-urea/clay nanocomposite coatings have been studied in relationship to clay dispersion and intercalation of clay platelets in the urethane-urea matrix. Coatings were prepared by moisture curing of IPDI capped hydroxyl terminated polybutadiene/clay dispersions in a relative humidity (RH) of 50% at 25° C. Moisture cured polyurethane-urea coatings have been made by reacting 1,2,3-triazole rich polyether polyols with HMDI at NCO/OH eq. ratio of 1.2 to obtain isocyanate-terminated polyurethane prepolymers. The prepolymers were cured under atmospheric moisture to make polyurethane-urea free films. 
     In some examples, the composition may be free of solvents and isocyanates, and have excellent long-term resistance to UV and weathering, making it useful for both interior and exterior applications. Some compositions may not work well with certain olefin class plastics or in applications with pressure in excess of 20 psi, such as garden hoses. Non-limiting examples of commercial products that may be used include DAP® 3.0 sealant, an advanced hybrid polymer-based product available from DAP Products Inc., and OSI® QUAD® MAX, a silane modified polymer-based product available from Henkel Corporation. According to its safety data sheet, QUAD® MAX includes 50-60 wt. % limestone (CAS 1317-65-3), 5-10 wt. % phthalic acid, di(C9-11)alkylester, branched, C10-rich (CAS 68515-49-1), 1-5 wt. % trimethoxyvinylsilane (CAS 2768-02-7), and 0.1-1 wt. % quartz (SiO 2 ) (CAS 14808-60-7). 
     If desired, the paste may be formulated in a variety of colors tailored to particular applications or consumer preferences. For example, paste compositions may be clear, white, off-white, black, gray, blue, green, red, almond, brown, silver, yellow, terra cotta, or other suitable color. The selection of appropriate pigment(s) or other colorant(s) needed to achieve a desired color will be apparent to persons skilled in the art with the aid of no more than routine experimentation. Alternatively, the paste may be painted after application, e.g., subsequent to curing. In some examples, the cured paste may be sanded prior to painting. 
       FIGS. 1A and 1B  illustrate the repair of a leak in a liquid container  40 , e.g., a 5- or 10-gallon bucket, 55-gallon drum, or large storage tank. The container  40  contains water  42  or other liquid, which is discharged through aperture  41 . The aperture  41  may be circular, as shown in  FIG. 1A , or may be of various other shapes such as an elongated gash, for example, or may be irregularly shaped depending on the source of damage to the container. For example, a circular hole  41  may have an approximately 1″ diameter. While water  42  discharges through the aperture  41 , a quantity of paste  44  may be applied to the container so as to cover the aperture  41 . The quantity of paste  44  may be selected so that the aperture  41  is completely covered as well as a sufficiently large area surrounding the aperture  41  to allows a watertight seal to be created. By way of example, the surface area of the applied paste  44  may be about 200% or more of the surface area of the aperture  41 . As shown in  FIG. 1B , after its application the paste  44  is effective to prevent further discharge of water through the aperture  41 . 
     In one example, the container  40  may be a wooden barrel or portion thereof. The aperture  41  may be formed by cutting through a wall portion of the wooden barrel, e.g., a side or an end portion of the barrel, using a suitable cutting tool such as a chainsaw (not illustrated). 
     The water that gushes through the aperture  41  may be collected in a reservoir (not illustrated) and then recirculated into the container  40  via a suitable pump (not illustrated) to replenish the water, e.g., to maintain the water in the container  40  at a constant or substantially constant level. As the water  42  gushes through the aperture  41 , a quantity of paste  44  is applied to the container so as to cover the aperture  41  and form a watertight seal, thereby preventing water from further discharging through the aperture  41 . 
       FIGS. 2A and 2B  schematically illustrate the repair of a conduit  50  such as a PVC pipe, garden hose, pool or hot tub filter hose, or the like. The conduit  50  has an aperture  51  therein through which water or other liquid is discharged, as shown in  FIG. 2A . While water is being discharged through the aperture, a quantity of paste  55  is applied to the conduit  50  to cover the aperture  51  and create a watertight seal. The quantity of paste  55  may be appropriately selected depending on the size and shape of the aperture  51 . As described above in connection with the embodiment of  FIGS. 1A and 1B  and as illustrated in  FIG. 2B , it may be advantageous to apply the paste  55  over an area significantly larger (e.g., 200% or more) than that of the aperture  51  in order to form a watertight seal, thereby preventing further discharge of water through the aperture  51 . 
       FIGS. 3A and 3B  schematically illustrate a method of repairing a leak in a water-containing structure  60  such as an above-ground swimming pool, hot tub, or aquarium. An aperture  61  that exists below the water level  62  may be repaired by applying a quantity of paste  66  over the aperture  61  to create a watertight seal. The paste  66  may be applied to the inside surface of the structure  60  even though the aperture  61  is surrounded by water. Thus, it is not necessary to drain the water from the structure  60  before making the repair. The quantity of the paste  66  should be selected so that the aperture  61  is completely covered as well as a sufficient area surrounding the aperture  61 , as discussed above in connection with previous examples, to allow formation of a watertight seal. If desired, another quantity of paste (not illustrated) may be applied to the outside surface of the structure  60  covering the aperture  61  to reinforce the watertight seal. 
     In other aspects, the paste may be used for underwater repairs, as shown schematically in  FIGS. 4A and 4B .  FIG. 4A  shows a vessel  90  having a partially submerged hull  93 . An aperture  91  is formed in the submerged portion  93 , which may be an elongated gash as depicted in  FIG. 4A . An appropriate quantity of paste  99  may be applied onto the submerged hull  93  covering the aperture  91  to create a watertight seal. The paste  99  may be applied to the outside surface of the hull  93 , as shown in  FIG. 4B . In some examples, another quantity of paste (not illustrated) may be applied to the inside surface of the hull  93  covering the aperture  91  to reinforce the watertight seal. 
     The paste may be applied to pipes and hoses, such as the ends of downspouts, gutters, PVC pipes, irrigation pipes, conduits, etc. to attach segments together in a watertight manner. After the paste is applied, the downspout or PVC pipe to which it is applied may be adhered to a fitting or junction element in a watertight manner. 
     In addition to the applications and benefits as set forth herein, there are benefits in these techniques as demonstrating the uses, the ease of the use, and the advantages of the rubberized adhesive pastes by each of these processes. For example, by making articles waterproof, the techniques described herein further provide benefits associated with avoiding contact with moisture, including making articles rust-resistant, mold-resistant, mildew-resistant, and the like. 
     The foregoing description should be considered illustrative rather than limiting. It should be recognized that various modifications can be made without departing from the spirit or scope of the invention as described and claimed herein.