Patent Application
20060059825
The present invention relates to methods for fastening two or more building materials together to achieve improved structural integrity and sound-deadening effects, and more particularly to a two-sided adhesive membrane assembly for attaching flooring, decking, roofing, wall components, and the like to mounting substrates.
Adhesives are available for achieving improved structural integrity and bonding between common building materials such as subfloor installations. Heavy-duty adhesives sold by ICI Paints under the tradename LIQUID NAILS® are sold, for example, for increasing the structural integrity of walls and subfloor systems. These liquid adhesives can be used with, plywood, foamboard, particle board, lumber and treated lumber, waferboard, and OSB. Such a construction adhesive provides for “quiet” floor assemblies in that the adhesive is said to eliminate squeaking between boards and between the boards and nails.
Unfortunately, the decking, flooring, or other component must be attached within fairly short time, such as twenty minutes. Otherwise, a skin will begin to form on the adhesive that can impede the formation of a strong adhesive bond between the building materials. In addition, the liquid adhesive must be applied using a caulking gun so that the liquid adhesive can be squeezed out of a plastic nozzle at the end of a cardboard tube. The application of the adhesive over relatively large surface areas may thus become tiring, inconvenient, and time-consuming.
In view of the foregoing disadvantages, a novel method is needed for fastening building materials together in a quick and convenient manner that achieves noise reduction and enhances structural integrity.
In surmounting the disadvantages of the prior art, the present invention provides a method for joining two or more building materials involving the use of a membrane assembly having differing pressure-sensitive surfaces on opposing major faces. The method is suitable for building applications whereby surface components, such as plywood, foamboard, particle board, lumber and treated lumber, waferboard, and OSB (oriented strand board), deck planks, floor planks, wall panels, roofing tiles or other surface components are mechanically fastened to deck joists, floor boards, wall studs, roofing decks, and other mounting substrates in a manner that is fast and convenient while providing sound-deadening and structural integrity.
For decking and flooring applications in particular, the membrane assemblies help to minimize unwanted noise, such as squeaking, that can arise when one component (e.g., floor, plank) impacts or rubs against joists or floor boards. Unwanted movement of the components is minimized by the additional adhesion, and energy, such as squeaking from sliding against nails, is absorbed by the additional adhesive surface of the membrane assembly. Decking becomes loose as a result of fatigue (due to repetitive foot traffic), differential thermal expansion, differential moisture absorption. Foot traffic also causes noise due to the friction between joists and boards and also between these components and the nails used for fastening them together. Thus, the membrane assemblies of the invention help to prevent or minimize the unwanted movement of the material components as well as to deaden the sound created by their relative movements.
Thus, an exemplary method of the invention comprises positioning between two substrates a membrane assembly having a sheet-like body structure having opposing first and major faces, the first major face comprising a first pressure-sensitive adhesive surface which adheres the membrane assembly to one of the substrates upon pressed contact, and the second major face thereof comprising a second pressure-sensitive adhesive surface having an initial tack that is less than that of the first pressure-sensitive adhesive surface and whereby a second substrate placed into pressing contact against the second pressure-sensitive adhesive surface can be repositioned into another contact placement without destroying the integrity of the surface of the second pressure-sensitive adhesive surface. It is also possible that the second pressure-sensitive adhesive surface provides minimal or no initial tack, but does provide a good adhesive bond over time after the components are placed into contact with one another and pressed together by force of the mechanical fasteners (e.g., nails or screws). The membrane assembly can be affixed first to either of the two substrates, preferably with the more aggressive adhesive surface first, followed by subsequent attachment to the other substrate, and then the fastener is driven through the substrates and membrane assembly.
The invention also relates to building structures made in accordance with the above-described method. Further advantages and features are described herein and after.
The following detailed description of exemplary embodiments may be more readily appreciated in conjunction with the appended drawings, wherein
The mechanical fastening of one substrate to another substrate, using the double-adhesive-sided membrane assembly 10, will usually involve nails or screws. However, it is contemplated that other mechanical fasteners may include staples, spikes, clamps, and other devices.
The exemplary membrane assembly 10 preferably has a sheet like body, and is preferably flexible so that it can be shipped in roll form and unrolled at the site of installation. The sheet like body has opposing first and major adhesive surfaces, which are preferably continuous, in that they extend from one edge of the membrane to the other edge. The first adhesive surface, shown positioned against a first substrate 20, is a pressure-sensitive adhesive operative to attach the membrane assembly 10 firmly against the first substrate 20 with hand pressure.
The first substrate 20, for example, may be a deck joist, roof joist, or wall stud, and the second substrate 30 thus a plank made of wood (treated lumber), plywood, plastic lumber, fir decking, mahogany decking, oriented strand board (OSB), a composite, or material commonly used for such constructions. The first substrate 20 could also comprise plywood, OSB, Masonite, fiberboard, while the second substrate 30 could be flooring planks, hardwood or softwood tongue in groove flooring planks, panels, boards, or tiles. In yet another embodiment, the first substrate 20 could also be a roof deck (sloped or unsloped), while the second substrate 30 could be roofing components such as asphalt shingles, slate tiles, cedar shingles, metal tiles, or plastic, metal, felt, or composite sheeting. In many of these cases, the membrane assembly 20 serves to providing a waterproofing barrier to prevent moisture from accumulating against the adjacent surfaces of the substrates (20 and 30), and may primarily serve to provide sound deadening effects such as preventing either substrate from rubbing against the membrane assembly 10 due to the securing effect of the two adhesive surfaces. The membrane assembly 20 also serves to increase the structural rigidity of the result structure.
In other exemplary embodiments of the invention, one or both of said substrates can comprise a pre-made building material selected from the group consisting of wood, plywood, oriented strand board, gypsum, concrete, mortar, brick, or tile.
The first adhesive surface is preferably of sufficient tenacity that pressing the membrane assembly 10 against the first substrate 20, using hand pressure, is sufficient to adhere the membrane such that subsequent attempts to position the membrane would disrupt portions of the adhesive surface (i.e., some adhesive would be torn from the membrane and remain stuck to the first substrate 20 if repositioned after pressing contact).
However, the second adhesive surface, located on the major face of the membrane assembly, should have an initial adhesive tack that is substantially less than that possessed by the first adhesive surface, such that the second substrate 30 can be placed into pressing contact against the second adhesive surface and yet re-positioned if the need arises (without tearing apart the second adhesive surface), before the second substrate 30 is nailed or screwed into place against the first substrate 20 and membrane assembly 10. As will be discussed further below, the second adhesive surface may be rendered less initially tacky by coating it with a powdered material or embedding filler material (e.g., fibers) in the surface. Alternatively, the second adhesive surface may be formulated with low tack without filler. Preferably, the second adhesive comprises a slightly tacky rubber, filler, and no plasticizer or tackifier. The filler level may range from very high (90% filler by weight) or may be entirely free of filler. Preferred rubbers include polymers comprising acrylic esters.
Once the second substrate is nailed or screwed into place against the membrane assembly 10, the strength of the adhesive bond between the membrane 10 and second substrate 30 preferably increases. This increase in the strength of the adhesive bond may be brought about by a number of factors, such as the ability of the second adhesive to flow and make contact with the substrate, when subjected to the pressure exerted by the mechanical fastener over time against the second substrate 30. Alternatively, for a second adhesive layer coated with a filler (particles), the adhesive may flow around the powdered material and make contact with the substrate when subjected to long term pressure after the second substrate 30 is mechanically fastened to the first substrate 20 (such as by nailing, screwing, clamping, or other mechanical pressure or force). The strength of the adhesive bond may also be later enhanced or arising as a matter of course through other means, such as the application of heat (e.g., exposure to sunlight or elevated temperature of roof tops) depending on the purpose or application.
Optionally, the second adhesive layer 13 may be rendered less initially tacky by having a coating layer of particulates or fiber material 14 on its surface. In further exemplary embodiments, the second adhesive layer 13 may incorporate a filler material (e.g., particulate material) as well as have the coating of filler material on its outward surface.
Preferably, the less-initially-tacky adhesive layer 13 comprises an acrylic ester rubber. The glass transition temperature of this rubber is preferably less than or equal to −10 degrees C.
In a further exemplary embodiment of the invention, the membrane assembly 10 may have different adhesive layers. Turning to
The physical dimensions and thicknesses for the various exemplary component layers of the membrane assembly 10 may be as conventionally employed for waterproofing membranes or sound-deadening membranes as the case may be. For example, the total thickness of the one or more adhesive layers (11, 13, 14) may be 0.5-100 mils. If the outermost layer 14 comprised particles alone rather than a particle-filled adhesive, then the thickness of the outermost layer 14 would be relatively thin depending on the average size of the particles. Where the first adhesive layer 11 is used for providing attachment to a building material substrate, such as roof joists, floor joists, or wall studs, roof deck, or floor deck. The thickness of the first waterproofing adhesive layer 11 may be 5-80 mils, and more preferably 10-60 mils. The thickness of the second and third adhesive layers (13, 14) may be 0.5-20 mils each. Use of larger thicknesses may be particularly suitable for achieving sound deadening properties with respect to the securing of the second substrate 30. If the optional reinforcement layer 12 is a film, thicknesses may be in the range of 0.5-20 mils, while a woven or nonwoven fabric may have a weight in the range of 0.5-5.0 ounces/yard. The membrane assembly 10 may have an edge-to-edge width of 0.01-10.0 meters or more. Preferably, the width is approximately equal to that of the floor joist, roof joist, or wall stud to which the first adhesive layer 11 is attached.
As previously mentioned, the membrane assemblies 10 of the invention can be transported in roll form or they may be used pre-attached to the substrate. In any event, a release liner sheet (not shown) preferably having a releasable coating on both sides, can be used to protect the adhesive surfaces and then removed before installation. The releasable property may be achieved by coating a paper or plastic film with silicone, wax, or other release agent. Plastic films used for this purpose include plastic materials such as polyolefins (e.g., polyethylene, polypropylene) and polyester (e.g., polyethylene terephthalate).
Once at the application site, a rolled membrane assembly 10 can be unrolled such that the release sheet remains temporarily attached to less-initially-tacky adhesive surface (such as designated as 13/14 in
The pressure-sensitive adhesive layers (e.g., 11, 13, 14) may comprise polymeric materials such as styrene isoprene styrene (SIS), styrene butadiene styrene (SBS), styrene ethylene butadiene styrene (SEBS), natural rubber, butadiene, acrylic rubber, neoprene, silicone, isoprene, or mixture thereof. Adhesive compositions employed in the invention may also comprise a rubber-modified asphalt or bitumen, as would be known to those skilled in waterproofing building foundations, walls, and roofing structures. The pressure-sensitive adhesive layer may also comprise one or more tackifiers and/or plasticizers (which can be used to increase adhesion when compared to rubber alone) and/or one or more fillers and particles (which can be used to decrease adhesion, including initial tack).
Usually, tackifier components exhibit lower molecular weight and glass transition temperature (Tg) than the rubber being modified. For a given rubber type and grade, the tackifier and plasticizer are selected to achieve the desired balance of properties. It is expected that those skilled in the art of adhesives or adhesive formulations would be able to achieve desired pressure-sensitive adhesive properties using various components, as contemplated by the present invention. For example, it is known that polymers comprising acrylic esters (e.g., butyl acrylate, ethyl hexyl acrylate and other acrylic esters with four or more carbons in the ester chain) are inherently pressure sensitive, although some of these are generally less initially tacky when compared to certain other adhesive systems (e.g., rubber modified bitumen, SIS, etc., with plasticizer and tackifier or other combinations of rubber, plasticizer, and tackifier).
The second pressure-sensitive adhesive layer 13, which may otherwise be considered a “less-initially-tacky” adhesive layer (i.e., the surface of adhesive having the less-intially-tacky adhesive face) may include, or be coated with, particulate materials to decrease initial tackiness (i.e., adhesive bond strength upon first physical contact).
Exemplary particulate materials useful for incorporating into and/or coating the less-initially-tacky adhesive layer (or surface) include calcium carbonate, sand, silicate sand, cement, talc, titanium dioxide, carbon black, slate dust, granite dust, clay, diatomaceous earth, limestone, metakaolin clay, smectite clay, shale, fly ash, silica fume, granulated blast furnace slag, alkaline or alkaline earth metal nitrites or nitrates, halides, sulfates, carboxylates, such as calcium, potassium, sodium salts, or mixtures thereof. Aluminum oxide trihydrate particles are also believed to be suitable. A number of particulate materials which are also believed to be suitable for the purposes of the present invention are disclosed in U.S. Pat. Nos. 5,496,615 of Bartlett et al. and 6,500,520 of Wiercinski et al.
Other materials believed to be suitable for decreasing initial tackiness of the second adhesive layer 13 may include fibrous materials such as cellulose, polymeric fibers (e.g., polyolefin), cotton, hemp, glass, and other materials.
Exemplary less-initially-tacky, pressure-sensitive adhesive layers 13 (if outermost) or 14 may comprise a combination of the adhesive materials and optional particulate and/or fibrous materials as described above. The adhesive material of the less-initially-tacky adhesive layer (outermost) 13 and/or 14 may be chosen such that it is different from, because it has lower adhesive bond strength than, the adhesive material chosen for the first pressure-sensitive adhesive layer 11. Indeed, the adhesive material for both adhesive layers 11 and 13 could comprise the same components (except filler levels), but the second second adhesive layer 13 may be rendered less-initially-tacky in comparison by including lower amounts of plasticizer and/or rubber tackifying agents (or omitting them entirely), and/or by including particulate and/or fibrous materials such as described above.
Exemplary less-initially-tacky pressure sensitive layers 13 of the present invention have an adhesion value of less than or equal to 1 pounds per lineal inch when tested in accordance with a standard initial adhesion test. Preferably, the outermost less-initially-tacky pressure-sensitive adhesive layers (13 or 14) of the present invention have an adhesion value of less than or equal to 0.5 pounds per lineal inch when tested in accordance with a standard initial adhsion test. The standard test is described as follows. A 3″×8″ piece of 2 sided tape is used for the test. The release liner is left in contact with the pressure sensitive layer 11. The less-initially-tacky, pressure-sensitive adhesive layer 13 is applied to a 3″×8″ plywood surface. All materials are at 75 degrees F. The membrane assembly is rolled with a 30 lb roller. Four 1 sec. passes are made in the long direction of the sample. The tape is peeled off of the plywood substrate at an angle of 180 degrees, at a peel rate of two inches per minute, fifteen minutes after rolling.
Exemplary less-initially-tacky pressure sensitive layers (13 if outermost or 14) exhibit significantly improved adhesion, when compared to that measured in the initial test (hereinafter “initial” adhesion) after extended contact with a substrate under pressure (hereinafter “aged” adhesion value). The initial adhesion value is greater than or equal to 0.5 pounds per lineal inch. Preferably, the aged adhesion value is greater than or equal to three pounds per lineal inch. The test is described as follows. A 3″×8″ piece of two-sided tape is used for the test. A release liner is left in contact with the pressure sensitive layer 11. The less-initially-tacky, pressure-sensitive adhesive layer 13 is applied to a 3″×8″ plywood surface. All materials are at 75 degrees F. The membrane assembly is rolled with a 30 lb roller. Four 1 sec. passes are made in the long direction of the sample. Another 3″×8″ sample of plywood is placed on the surface comprising the release liner. Six self-tapping screws are fastened through the assembly, spaced evenly apart. Four screws are located near the corners one inch from the shortest edges, and two midway along the longitudinal sides, with all screws being approximately 0.5 inches from the long sides of the rectangular sample. The test assembly is aged at room temperature for 48 hours, and screws removed. The less-initially-tacky pressure sensitive layer 13 is peeled off the plywood substrate at an angle of 180 degrees at a rate of two inches per minute.
Accordingly, an exemplary “less-initially-tacky” adhesive layer (e.g., 13) of the present invention will have adhesion value of less than or equal to 0.5 pounds per lineal inch when tested in accordance with a standard initial adhesion test. After 48 hours of compressed contact against a plywood substrate, this adhesive layer 13 will have an adhesion value of greater than or equal to three pounds per lineal inch.
The choice of adhesives and adhesive formulations and optional reinforcement sheet materials for a given membrane assembly 10 of the invention may well depend upon the nature of the application at hand. The substrate may comprise materials such as wood, gypsum, metal (e.g., steel, aluminum), concrete, or synthetic polymers (e.g., plastic, resins).
Accordingly, further exemplary embodiments of the invention include structures or assemblies made from the methods described above, wherein the second substrate 30 is mechanically fastened, using nails, screws, or other mechanical fasteners, to the first substrate 20, through the membrane assembly 10.
Preferred structures are those wherein both substrates are made of wood, plywood, or oriented strand board (OSB), and nails or screws are used for mechanically securing them together, using the membrane assembly 10 to provide adhesive sealing at their interfaces. In floors, roof, and deck structures, wood will probably be made using pine, spruce, fir, or engineered lumber; while the second substrate may be wood, plywood, OSB, gypsum board, a floor (hard wood, ceramic tiles, fiber board), roofing tiles or sheets (e.g., fiberglass), or decking (e.g., pine, mahogany, engineered plastics).
The use of the membrane assembly 10, as previously mentioned, is operative to provide a number of benefits. For example, it can prevent water or moisture from accumulating at the surfaces of the respective first substrate 20 and second substrate 30; it can provide enhanced structural integrity (when compared to using only the fasteners); and it can provide sound deadening. As for the last mentioned benefit, the two-adhesive-sided membrane assembly 10 would be particularly helpful in providing a quiet construction using plywood or oriented strand board which has been nailed or screwed onto floor joists, wall studs, roof joists, or other mounting substrates. In floors, any squeaking caused by loose decking (caused by traffic) or sliding along joists or nails or screws (caused by warpage, contraction, expansion, etc.) will tend to be minimized by the membrane assembly 10.
For example, the membrane assembly 10 can minimize squeaking in deck or flooring construction in at least two ways: by providing better/fuller adhesion between the decking/flooring and joists (in contrast to the nails or screws alone); and by dampening any sound that may be created as decking impacts or rubs against itself, the joists, or fasteners.
As an alternative method of the invention, the membrane assembly 10 can be installed by first applying the less-initially-tacky adhesive surface (e.g, designated at 13 in
Thus, further exemplary embodiments of the invention comprise a building material substrate, such as a floor or roof tile having slidably attached thereto (e.g., it is attached but re-positionable) a membrane assembly, the membrane assembly having two major opposing adhesive faces, the first adhesive face thereof comprising a pressure-sensitive adhesive surface, the second opposing adhesive face thereof comprising a pressure-sensitive adhesive surface having a less-initially-tacky pressure sensitive adhesive face in comparison to said first adhesive face. In this exemplary embodiment, the less-initially-tacky pressure-adhesive face would be installed, pre-attached to a substrate 30 (e.g., floor or roofing tile), and a protective release liner sheet would be removed to expose the first pressure-sensitive adhesive layer, which is attached onto the mounting substrate, such as joists or other building mounting surface.
Thus, further exemplary embodiments of the invention include building materials, such as floor, wall, ceiling, roof, or decking boards, tiles, or other such surface components having a repositionable two-sided adhesive membrane assembly (10) attached releasably thereto using the less tacky adhesive surface (e.g., 13). The present invention thus contemplates the use of “pre-made” building materials as substrates, in the sense that these substrates are provided in solid form (e.g., not as wet fresh concrete cast into place against the membrane and allowed to harden).
Thus, an exemplary building material assembly, comprises a membrane assembly having a sheet-like body structure with opposing first and major faces, the first major face comprising a first pressure-sensitive adhesive surface which adheres the membrane to a first substrate upon pressed contact, and the second major face thereof comprising a second pressure-sensitive adhesive surface having an initial tack that is less than that of the first pressure-sensitive adhesive surface, whereby a second substrate placed into pressing contact against the second pressure-sensitive adhesive surface can be repositioned into another contact placement without destroying the integrity of the surface of the second pressure-sensitive adhesive; the building material assembly further comprising a substrate that is releasably adhered against the second pressure-sensitive adhesive surface; and the building material assembly further comprising a release sheet liner that is removably attached to the first pressure-sensitive adhesive surface. Thus, the release sheet can be removed, and the releasably attached substrate (e.g., floor, wall, roof, ceiling, or other building surface component) can be adhered to and mechanically fastened to a mounting surface, such as a joist, beam, panel, or other mounting structure.
The following examples are used for illustrating certain embodiments of the invention, and are not intended to limit the scope of the invention.
This example provides a demonstration that the less-initially-tacky pressure sensitive layer 13 (outermost, see e.g.,
Exemplary less-initially-tacky pressure sensitive layers 13 exhibit an (initial) adhesion value of less than or equal to 0.5 pounds per lineal inch when tested in accordance with standard peel adhesion test, which is described again hereinbelow as follows. Preferably, the less-initially-tacky pressure-sensitive adhesive layers exhibit an initial adhesion value of less than or equal to 0.5 pounds per lineal inch when tested in accordance with a standard peel adhesion test. A 3″×8″ piece of two-sided tape is used. A release liner is left in contact with the pressure sensitive layer 11. The less-initially-tacky, pressure-sensitive adhesive layer 13 is applied onto a 3″×8″ plywood surface. All materials are at 75 degrees F. The assembly is rolled with a 30 lb. roller. Four 1 sec. passes are made in the long direction of the sample. The tape is peeled off of the plywood substrate at an angle of 180 degrees, at a peel rate of two inches per minute, fifteen minutes after rolling.
Exemplary less-initially-tacky pressure sensitive layers 13 were found to exhibit significantly improved adhesion, compared to initial adhesion measurements, after long-term contact with a substrate under pressure. The adhesion value is found to be greater than or equal to 0.5 pounds per lineal inch. Preferably, the adhesion value is greater than or equal to three pounds per lineal inch. The test is described below. A 3″×8″ piece of 2 sided tape is used for the test. The release liner is left in contact with the pressure sensitive layer 11. The less-initially-tacky, pressure-sensitive adhesive layer 13 is applied to a 3″×8″ plywood surface. All materials are at 75 degrees F. The assembly is rolled with a 30 lb roller. Four 1 sec. passes are made in the long direction of the sample. Another 3″×8″ sample of plywood is placed on the surface comprising the release liner. Six self-tapping screws are fastened through the assembly, spaced evenly apart with screws located near each of the four corners and two along the longitudinal sides, all six screws being approximately 0.5-1 inch from the edges of the rectangular sample. The test assembly is aged at room temperature for 48 hrs. The screws are removed. The less-initially-tacky pressure sensitive layers 13 is peeled off the first plywood substrate at an angle of 180 degrees F. at a rate of two inches per minute. The average adhesion value is reported. Adhesion is highest where the screws are applied; but adhesion is lower at distances furthest from the screws.
Results for two different less-initially-tacky pressure sensitive layers 13 (one comprising a high level of filler and the other comprising a low level of filler) and a (non-particulate-filled) pressure-sensitive adhesive layer 11 are shown in the table below. It was observed that the less-initially-tacky pressure sensitive layers 13 exhibited initial adhesion values less than or equal to 0.5 pounds per lineal inch, and “long term” adhesion values of greater than or equal to 0.5 pounds per lineal inch (after 48 hours in compressed contact with substrate).
The formulation comprising the acrylic with 4% filler has very low initial adhesion but excellent long term adhesion peel strength. In contrast, the exemplary pressure sensitive layer 11, which was based on a styrene-isoprene-styrene adhesive (SIS), exhibited excellent initial adhesion.
The foregoing embodiments are provided for illustrative purposes are not intended to limit the scope of the invention.
| Number | Date | Country | |
|---|---|---|---|
| 60598151 | Aug 2004 | US |
