Multilayer tape

Abstract

The invention relates to a multi-layer belt. Vibration damping viscoelastic damping material laminates are described. The belt (10) generally includes at least two layers (30, 50) of viscoelastic damping material and at least one substrate (40). The tape may optionally include one or more release pads (20, 60). A restraint layer system formed by adhering the tape (10) to a first substrate and / or a second substrate that undergoes vibration is also described.

Description

[0001] This application is a divisional application. The application date of the original application is September 20, 2017, the application number is 2017800575354, and the name of the invention is “Multi-layer tape”. Technical Field

[0002] The present subject matter relates to a tape for damping vibrations, comprising an adhesive tape. Background Art

[0003] Vibration-damping adhesive tapes are well known in the art. However, to achieve the desired vibration-damping properties, most such adhesive tapes are relatively thick, utilize large amounts of adhesive, and / or significantly increase the overall weight of the system or assembly experiencing vibration. Therefore, a need remains for adhesive tapes that effectively dampen or reduce vibrations and are relatively thin and / or lightweight. Summary of the Invention

[0004] The difficulties and shortcomings associated with previous approaches are addressed in the present subject matter as follows.

[0005] In one aspect, the present subject matter provides a belt for damping vibrations. The belt includes a substrate defining a first side and an oppositely oriented second side. The belt also includes a first layer of viscoelastic damping material disposed at least partially on the first side of the substrate. The belt additionally includes a second layer of viscoelastic damping material disposed at least partially on the second side of the substrate. The thickness of the substrate can range from about 5 μm to about 3,000 μm, and the thickness of each layer of viscoelastic damping material can range from about 2 μm to about 5,000 μm.

[0006] In another aspect, the present subject matter provides a belt for damping vibrations. The belt includes a first substrate and a second substrate. The belt also includes a first layer of viscoelastic damping material at least partially disposed between the first and second substrates. Further, the belt additionally includes a second layer of viscoelastic damping material. The second substrate is at least partially disposed between the first and second layers of viscoelastic damping material. Each of the first and second substrates has a thickness in a range from about 5 μm to about 3,000 μm. Furthermore, each of the first and second layers of viscoelastic damping material has a thickness in a range from about 2 μm to about 5,000 μm.

[0007] In yet another aspect, the present subject matter provides a constrained layer system (also referred to as a surface) comprising at least one of a first component and a second component that is subjected to vibration. The first component and / or the second component can be constructed of any material requiring damping, including but not limited to metal, plastic, and wood. The tape described herein is at least partially disposed between the first component and the second component. The system also includes a vibration damping tape comprising (i) a substrate defining a first side and an oppositely oriented second side, (ii) a first layer of viscoelastic damping material at least partially disposed on the first side of the substrate, and (iii) a second layer of viscoelastic damping material at least partially disposed on the second side of the substrate. The thickness of the substrate is in the range of about 5 μm to about 3,000 μm, and the thickness of each layer of the viscoelastic damping material is in the range of about 2 μm to about 5,000 μm. At least one of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material is adhered to at least one of the first component and the second component.

[0008] In yet another aspect, the present subject matter provides a constrained layer system comprising at least one of a first component and a second component that are subjected to vibration. The system further comprises a vibration damping tape comprising (i) a first substrate, (ii) a second substrate, (iii) a first layer of viscoelastic damping material at least partially disposed between the first substrate and the second substrate, and (iv) a second layer of viscoelastic damping material, wherein the second substrate is at least partially disposed between the first layer of viscoelastic damping material and the second layer of viscoelastic damping material. Each of the first substrate and the second substrate has a thickness in a range of about 5 μm to about 3,000 μm. Furthermore, each of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material has a thickness in a range of about 2 μm to about 5,000 μm. At least one of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material is at least partially adhered to at least one of the first component and the second component.

[0009] As will be realized, the subject matter described herein is capable of other and different embodiments and its several details are capable of modifications in various respects, all without departing from the subject matter claimed.Accordingly, the drawings and description are to be regarded as illustrative and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic cross-sectional view of an embodiment of a viscoelastic damping material laminate or tape according to the present subject matter.

[0011] Figure 2 is a schematic cross-sectional view of another embodiment of a viscoelastic damping material laminate or tape according to the present subject matter.

[0012] Figure 3 and Figure 4 is used Figure 1 Schematic cross-sectional view of the constraining layer system of the belt in FIG.

[0013] Figure 5 is used Figure 2 Schematic cross-sectional view of the constrained layer system of the belt in FIG.

[0014] Figure 6 is a graph of the composite loss factor as a function of temperature for a tape according to the present subject matter compared to two prior art tapes.

[0015] Figure 7 is a graph of the composite loss factor as a function of temperature for a tape according to the present subject matter compared to two prior art tapes.

[0016] Figure 8 is a graph of the linear density normalized damping efficiency index of tapes according to the present subject matter compared to commercially available tapes. DETAILED DESCRIPTION

[0017] The present subject matter provides viscoelastic damping material laminates (which may also be referred to herein as tapes) that exhibit relatively high vibration damping properties, which may be described as damping efficiency as described herein. In a particular form of the tape, the tape is relatively thin and / or lightweight compared to many currently known vibration damping tapes. The viscoelastic damping material laminates are provided in a variety of configurations, including single substrate configurations and multi-layer configurations utilizing two or more substrates. Each configuration includes at least two (2) layers of viscoelastic damping material and an optional isolation liner that is at least partially disposed on the viscoelastic damping material face(s). In some embodiments, the tape may include additional viscoelastic damping layers. In one embodiment, the tape may include at least three (3) layers: both the viscoelastic damping material and the substrate that is at least partially disposed on the surface of the viscoelastic damping material face(s). In some embodiments, the tape may include at least four (4) layers: both the viscoelastic damping material and the substrate that is at least partially disposed on the surface of the viscoelastic damping material face(s). In some embodiments, the tape can include at least five (5) layers of both the viscoelastic damping material and a substrate at least partially disposed on a surface of the viscoelastic damping material face(s). In some embodiments, the tape can include at least six (6) layers of both the viscoelastic damping material and a substrate at least partially disposed on a surface of the viscoelastic damping material face(s). While many of the embodiments described herein relate to first and second layers of viscoelastic damping material, any additional layers may also have these embodiments. In still other embodiments, the viscoelastic damping material(s) can exhibit at least one compositional gradient or region, for example, along the thickness of the viscoelastic damping material.

[0018] In some embodiments, composition gradients or regions can provide a gradual change in material properties from one surface of the viscoelastic damping material(s) to another surface. Additional viscoelastic damping layers can be disposed on top of each other or on at least one substrate. The present subject matter also provides constrained layer systems using viscoelastic damping material laminates.

[0019] substrate

[0020] The tapes of the present subject matter utilize one or more substrates. While specific embodiments of single substrate tapes and dual substrate tapes are described herein, it should be understood that the tapes of the present subject matter include tapes having additional substrates, including three substrates, four substrates, five substrates, and six or more substrates. The additional substrates may be disposed upon each other or upon at least one viscoelastic damping layer. In some embodiments, the substrates may be multi-layered and at least partially disposed upon each other. In tapes utilizing multiple substrates, the layers of viscoelastic damping material are typically at least partially disposed between adjacent substrates. For example, in one embodiment of the present subject matter, a tape is provided comprising five substrates, wherein the layers of viscoelastic damping material are at least partially disposed between adjacent substrates, and a fifth layer of viscoelastic damping material is disposed at least partially along a face of one of the outermost substrates.

[0021] The substrate used in the subject viscoelastic damping material laminates is relatively thin, i.e., having a thickness in the range of about 5 μm to about 3,000 μm, in many embodiments about 10 μm to about 500 μm, and in certain embodiments, about 125 μm or about 250 μm. In some embodiments, the room temperature Young's modulus of the substrate ranges from about 1 GPa to about 1000 GPa, in other embodiments about 20 GPa to about 500 GPa, and in certain embodiments about 40 GPa to about 200 GPa. In some embodiments, the substrate is a metal foil having a room temperature Young's modulus of at least 20 GPa.

[0022] In many embodiments, the substrate can be composed of or in the form of a metal foil. In some embodiments, there can be more than one substrate metal foil (which can be referred to as a first metal foil, a second metal foil, a third metal foil, etc.). Generally, any metal foil (including a first metal foil, a second metal foil, a third metal foil, etc.) can be used, including iron-based foils and non-iron-based foils. A variety of metals can be used, such as, but not limited to, aluminum, copper, tin, brass, gold, silver, nickel, steel, stainless steel, mixtures and / or alloys of these with other metals and / or reagents. In many embodiments, aluminum foil is used. However, it is contemplated that other metals and / or combinations of metals can be used, including columbium / niobium, hafnium, iridium, molybdenum and alloys, rhenium and alloys, tantalum, tungsten and alloys, platinum, platinum and iridium, alloys 42 and 52, Hastelloy, Inconel, Invar, etc. Kovar iron-based nickel-cobalt alloy Monel, Nichrome / Tophet "A", phosphor bronze, titanium, vanadium, zirconium and combinations thereof.

[0023] The present subject matter may include the use of coated metal foils and metal foils comprising one or more metals in combination with one or more agents. It is also contemplated that one or more polymeric films or coatings may be used in place of or in addition to one or more metal foils for the substrate of the viscoelastic damping material laminate. In one embodiment, the metal foil may comprise a metallized film.

[0024] The present subject matter may also include other materials for the substrate(s), such as heterogeneous layers or regions. In some embodiments, the substrate(s) may include one or more adjuvants dispersed in a matrix material. The adjuvants may be in the form of, for example, particles, flakes, fibers, geometrically shaped materials, and / or sheet-like regions of a first material having a chemical composition different from that of the matrix material. A specific example of a heterogeneous layer is a carbon fiber film. In another embodiment, the heterogeneous layer may include a polymer composite material having at least one layer of glass fiber or carbon fiber. In one example, the glass fiber may be impregnated with epoxy resin. In another example, the glass fiber may be FR-4 (also known as FR4). In some embodiments, the selection of the adjuvant(s) and the matrix material, as well as the degree of dispersion of the adjuvant in the matrix material, enables specific adjustment of the physical properties and characteristics of the heterogeneous layer(s) that can be used as the substrate(s). In yet other embodiments, the substrate(s) may utilize, for example, a foil that exhibits a composition gradient or region along the thickness of the foil. In some embodiments, the composition gradient or region can provide a gradual change in material properties from one surface to another. The metal foil may be a differential foil having a first iron region of iron foil and a second region of non-ferrous foil. In some embodiments, a differential foil having two or more regions of ferrous composition or non-ferrous-based composition, combined with two or more regions of non-ferrous composition or non-ferrous-based composition, may be used.

[0025] Viscoelastic damping materials

[0026] Each layer of the viscoelastic damping material(s) used in the viscoelastic damping material laminates of the present invention is relatively thin. In many embodiments, the relatively thin viscoelastic damping material laminate may have a thickness ranging from about 2 μm to about 5,000 μm, in many embodiments from about 10 μm to about 1,000 μm, and in certain embodiments, has a thickness of about 125 microns. In some embodiments, at least one of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material may include a viscoelastic damping material selected from, but not limited to, elastomers, butyl rubber, styrene block copolymers (referred to as SBCs, such as Kraton), polyurethanes, silicone rubbers, nitrile rubbers, isoprene, butadiene, viscoelastic polymer gels, pressure-sensitive adhesives (e.g., silicone, rubber, acrylic pressure-sensitive adhesives), non-pressure-sensitive adhesives, asphalt materials (e.g., roofing adhesives and mastics), and combinations thereof. In many embodiments, these viscoelastic damping materials may have a modulus that is dependent on both temperature and frequency, which may provide effective damping at approximately their glass transition. In other embodiments, both the first layer of viscoelastic damping material and the second layer of viscoelastic damping material may comprise a viscoelastic damping material selected from, but not limited to, elastomers, butyl rubber, styrene block copolymers (referred to as SBCs, e.g., Kraton), polyurethanes, silicone rubbers, nitrile rubbers, isoprene, butadiene, viscoelastic polymer gels, pressure-sensitive adhesives (e.g., silicone, rubber, acrylic pressure-sensitive adhesives), non-pressure-sensitive adhesives, asphalt materials (e.g., roofing adhesives and mastics), and combinations thereof. In many embodiments, these viscoelastic damping materials may have a temperature- and frequency-dependent modulus that provides effective damping about their glass transition. In many embodiments, the viscoelastic damping material may have a dielectric loss tangent maximum greater than about 0.5 at the temperature and frequency of the damping application. In some embodiments, the temperature range measured by a dynamic mechanical analyzer (DMA) at 10 rad / s may be from about -120°C to about 200°C, in many embodiments from -80°C to about 100°C, and in certain embodiments from about -60°C to about 75°C.

[0027] The viscoelastic damping material used in the subject tapes can exhibit viscoelastic properties at temperatures corresponding to the tape's application. Typically, the tapes are used and / or designed for applications within a temperature range of -30°C to 150°C. In some embodiments, the subject tapes also include tapes for use at temperatures that may be less than -30°C and / or greater than 150°C.

[0028] In many embodiments, the adhesive comprises a pressure sensitive adhesive (PSA). However, the present subject matter may also encompass the use of adhesives that are not pressure sensitive adhesives or "non-PSAs." For example, non-pressure sensitive adhesives may include, but are not limited to, heat seal adhesives, thermal adhesive films, B-stage adhesives, two-stage adhesives, dry adhesives, and combinations of these.

[0029] The pressure-sensitive adhesive material that can be used for vibration damping adhesive tape comprises rubber-based adhesive, acrylic adhesive, vinyl ether adhesive, silicone adhesive and / or two or more mixtures thereof.Be included in the pressure-sensitive adhesive material of describing in " Adhesion and Bonding ", Encyclopedia of Polymer Science and Engineering, volume 1, 476-546 pages, Interscience Publishers, second edition .1985, its disclosure is incorporated into this by reference.The pressure-sensitive adhesive material can comprise the adhesive polymer as main component, for example natural, regenerated or styrene butadiene rubber, the natural or synthetic rubber of tackifying, styrene butadiene or styrene isoprene block copolymer, the random copolymer of ethylene and vinyl acetate, ethylene-vinyl-acrylic acid terpolymer, polyisobutylene, poly (vinyl ether), poly (acrylic acid) ester etc.The typical feature of pressure-sensitive rubber and acrylic adhesive material is the glass transition temperature in the range of about -70 ℃ to about 20 ℃. Pressure sensitive silicone adhesive materials are typically characterized by a glass transition temperature in the range of about -20°C to about 100°C.

[0030] The acrylic adhesive may include as main components an acrylic polymer containing carboxylic acid, obtained from a vinyl monomer containing a carboxyl group, such as acrylic acid, methacrylic acid, etc., and an acrylic polymer containing hydroxyl groups, obtained from a vinyl monomer containing a hydroxyl group, such as 2-hydroxyethyl methacrylate, etc. In one embodiment, the acrylic adhesive material is obtained by copolymerization of an alkyl acrylate, such as butyl acrylate, 2-ethylhexyl acrylate, or isononyl acrylate; a polar monomer, such as acrylic acid, acrylamide, or N-vinyl-2-pyrrolidone; and another monomer, such as an acrylate other than the above-mentioned acrylates, a methacrylate, styrene, vinyl acetate, etc.

[0031] Other materials besides the aforementioned resins may be included in the pressure-sensitive adhesive material. These may include, but are not limited to, solid tackifying resins, liquid tackifiers (commonly referred to as plasticizers), antioxidants, fillers, pigments, waxes, etc. The adhesive material may contain a blend of a solid tackifying resin and a liquid tackifying resin (or liquid plasticizer).

[0032] In many embodiments, the viscoelastic damping materials, in addition to their improved vibration damping properties, exhibit beneficial adhesion properties, such as relatively high adhesion, good shear resistance, good temperature resistance, good chemical resistance, weathering resistance and resistance to environmental agents including UV radiation, good holding power, adhesion to low surface energy substrates, and adhesion to non-pristine surfaces such as dirty or oily surfaces as found in certain automotive applications.

[0033] In some embodiments, the first and second layers of the subject viscoelastic damping material can have the same chemical composition. In other embodiments, the first and second layers of the subject viscoelastic damping material can have different chemical compositions. In other embodiments, all layers of the viscoelastic damping material (where there are at least three layers of viscoelastic damping material) can have the same chemical composition. In another embodiment, all layers of the viscoelastic damping material (where there are at least three layers of viscoelastic damping material) can have different chemical compositions.

[0034] The layers of viscoelastic damping material in the subject tape (referring to both the first layer of viscoelastic damping material and the second layer of viscoelastic damping material) can be continuous or substantially continuous. In many embodiments, the layers of viscoelastic damping material are continuous and exhibit a uniform thickness. In some embodiments, the layers of viscoelastic damping material can be substantially continuous, wherein the layer(s) can have non-uniformities, such as unintentional defects or voids.

[0035] Release liner(s)

[0036] The viscoelastic damping material laminate of the present subject matter may optionally include one or more isolation pads(s) that at least partially cover or are disposed on the viscoelastic damping material layer(s). Typically, in many embodiments, a first isolation pad is at least partially disposed on the face of and covers the first viscoelastic damping material layer(s) of the viscoelastic damping material. Optionally, a second isolation pad may be at least partially disposed on the face of and covers the second layer of viscoelastic damping material. The present subject matter includes the use of a multi-component isolation pad assembly, such as a plurality of isolation pads that at least partially cover areas where the viscoelastic damping material layer(s) would otherwise be exposed. In certain embodiments, the belt may include multiple isolation pads, a single isolation pad, or no isolation pad(s).

[0037] The isolation pads used in the present invention can be those known in the art. Various isolation pads are available that can be applied to the viscoelastic damping material and can be used to protect the viscoelastic damping material from unintentional adhesion prior to use. Suitable isolation pads are described in detail in Chapter 23 of the Handbook of Pressure Sensitive Adhesive Technology, 2nd Ed., edited by Donatas Satas. Various isolation pads known in the art are suitable, as long as they are selected for their isolation properties relative to the viscoelastic damping material selected for use in the present invention.

[0038] Composite loss factor and damping efficiency

[0039] As provided herein, damping properties can be measured using CLF (composite loss factor) at a reference frequency of at least 50 Hz over a specific temperature range. In certain embodiments, 200 Hz can be used as a reference frequency. In some embodiments, when the CLF is at least 0.10 at a frequency of 200 Hz over the temperature range of application, the laminate structure can be considered damped. The temperature range of application can be from about -50°C to about 200°C. In some embodiments, when measured at a frequency of 200 Hz over a temperature range of 15°C, the laminate structure can be considered damped when the CLF is at least 0.05. As described herein, the span of the temperature range of 15°C can occur from about -50°C to about 200°C. In other embodiments, when measured at a frequency of 200 Hz over a temperature range of 15°C, the laminate structure can be considered damped when the CLF is at least 0.10, wherein the span of the temperature range of 15°C can occur from about -50°C to about 200°C.

[0040] In other embodiments, the damping properties of the laminate structure can be based on a damping efficiency index (described below). In one embodiment, the laminate structure can have a damping efficiency index of at least greater than 2000 at a frequency of at least about 50 Hz. In another embodiment, the laminate structure can have a damping efficiency index of at least greater than 2000 at a frequency of about 50 Hz to about 5000 Hz.

[0041] As used herein, damping efficiency is a measure of the composite loss factor (CLF) height and width normalized by its thickness and mass. For damping efficiency, the linear density normalized damping efficiency index, ζ = (W x M) / (ρ A xt) (in °C / (kg / m)) to evaluate the performance of different belts, where W is the width of the CLF curve for CLF ≥ 0.10 (in °C), M is the maximum value of the measured CLF, and ρ Ais the mass per unit area (kg / m 2 ), and t is the thickness of the total structure (m). In some embodiments disclosed herein, samples with improved damping may have a value greater than at least 2.0×10 3 The linear density normalized damping efficiency index (ζ).

[0042] Attached photos

[0043] Figure 1 is a schematic cross-sectional view of an embodiment of a tape 10 according to the present subject matter. The tape 10 includes a substrate 40 defining a first side 42 and an oppositely oriented second side 44. The tape 10 also includes a first layer of viscoelastic damping material 30 at least partially disposed on or along the first side 42 of the substrate 40. The tape 10 additionally includes a second layer of viscoelastic material 50 at least partially disposed on or along the second side 44 of the substrate 40. The tape 10 may also include one or more optional release liners, such as a release liner 20 at least partially disposed on and covering the first layer of viscoelastic damping material 30, and / or a release liner 60 at least partially disposed on and covering the second layer of viscoelastic damping material 50.

[0044] Figure 2 FIG1 is a schematic cross-sectional view of another embodiment of a strip 100 according to the present subject matter. Strip 100 includes a first substrate 110, a second substrate 130, a first layer of viscoelastic damping material 120 at least partially disposed between first substrate 110 and second substrate 130, and a second layer of viscoelastic damping material 140. Second substrate 130 is at least partially disposed between first layer 120 and second layer 140 of viscoelastic damping material. Strip 100 also includes an optional release liner 150 at least partially disposed on or along the second layer of viscoelastic damping material 140.

[0045] Belt form

[0046] The tape of the present subject matter can be provided in a variety of different forms. In many embodiments, the tape is provided in roll form, but other forms are included, such as sheet form and Z-fold form.

[0047] Application and Constraint Layer Systems

[0048] As described above, the tape of the present subject matter will find a wide range of applications for damping vibrations. When applied, i.e., adhered, to a first component, a constrained layer system is formed. The tape of the present subject matter can also be applied (i.e., adhered) to an optional second component. When the first component and the optional second component are subjected to vibrations, the tape and, in particular, the viscoelastic damping material layer(s) of the tape damp or reduce the vibrations. Although it is not desired to be limited to any particular frequency or frequency range, the tape of the present subject matter will be used to damp vibrations of at least 50 Hz. In other embodiments, the tape of the present subject matter can damp vibrations in the frequency range of about 50 Hz to about 15,000 Hz, more typically about 100 Hz to about 5,000 Hz, and in specific applications, about 200 Hz to about 3000 Hz.

[0049] The tapes of the present subject matter can potentially be used in any application in which it is desired to damp vibrations by forming a constrained layer system by adhering the tape to a first component that exhibits or experiences vibrations and optionally a second component of the system. The tapes of the present subject matter can also potentially be used in any application in which it is desired to damp vibrations by forming a constrained layer system by adhering (i.e., applying) the tape to at least one of the first component and the second component of the system that exhibits or experiences vibrations. Non-limiting examples include automotive applications, electronics applications, incorporation into power tools, aerospace applications, incorporation into household appliances such as washers, dryers, dishwashers, and industrial equipment such as motor housings and pump housings. Specific non-limiting examples of automotive applications include automotive door panels, brake assemblies including brake pads and brake shims, roofs, floors, heat shields, frames and frame assemblies, firewalls, and suspension assemblies. A non-limiting example of an electronics application is damping vibrations associated with a hard disk drive (HDD).

[0050] Figure 3 and Figure 4 Is to use a combination Figure 1 Schematic cross-sectional view of the constraining layer system of the tape 10 described previously. Figure 3 The constrained layer system 210 depicted in FIG. 1 includes a tape 10 (composed of a substrate 40, a first layer of adhesive 30, and a second layer of adhesive 50), a release liner (e.g., Figure 1 The release liner 60 shown in FIG. 1 is removed and the belt 10 is at least partially adhered by the layer 50 of viscoelastic damping material to a second component 70 that is subject to vibration or the potential for vibration to be damped. Figure 4 The constraining layer system 212 shown in FIG. 1 includes a tape 10 having two release liners (e.g., Figure 1 The isolation liners 20 and 60 shown in FIG are removed and the tape 10 is adhered to the second component 70 that is subject to vibration or potential vibration damping by the second layer of viscoelastic damping material 50 and to the first component 80 that is subject to vibration or potential vibration damping by the first layer of viscoelastic damping material 30. Further reference is made to Figure 4It will be appreciated that in many applications the first component 80 and / or the second component 70 may be in the form of a sound absorbing material, such as foam. The resulting assembly will provide both vibration damping and sound absorption. It will also be appreciated that in Figure 3 and 4 Additional layers of substrate and / or adhesive layers may be added.

[0051] Figure 5 Is to use a combination Figure 2 Schematic cross-sectional view of the previously described constraining layer system of the tape 100. The constraining layer system 300 includes the tape 100, a release liner (e.g., Figure 2 The release liner 150 (shown) is removed and the tape 100 is adhered to the second component 170 that experiences vibration or potential vibrations to be damped by the second adhesive layer 140 (also referred to herein as the second layer of viscoelastic damping material). Figure 5 In the embodiment, the first substrate is exposed rather than adhered or bonded to another substrate, viscoelastic damping material or component. Figure 5 ), the tape may be bonded to a first component experiencing vibration or potential vibration to be damped by a first adhesive layer (also referred to herein as a first layer of viscoelastic damping material), with the second substrate exposed, rather than adhered or bonded to another substrate, viscoelastic damping material, or component. It should also be understood that in Figure 5 Additional layers of substrate and / or adhesive layers may be added wherein the substrate remains exposed rather than adhered or bonded to another substrate, viscoelastic damping material, or component.

[0052] Figure 1-5 The embodiments described in the provide examples of the configurations described herein. It will be understood that the subject matter may include a belt having additional substrates, including three substrates, four substrates, five substrates, and six or more substrates. The additional substrates may be disposed on top of each other or on at least one viscoelastic damping layer. It will also be understood that the subject matter may include a belt having additional viscoelastic damping layers, including three layers of viscoelastic damping material, four layers of viscoelastic damping material, five layers of viscoelastic damping material, or six or more layers of viscoelastic damping material. The additional viscoelastic damping layers may be disposed on top of each other or on at least one substrate.

[0053] The following examples describe Figure 6 、 7 and 8.

[0054] Example

[0055] The vibration damping properties of several adhesive tapes according to the present subject matter were compared to the vibration damping properties of a commercially available vibration damping adhesive tape. In some embodiments, the laminates described herein were evaluated at similar thicknesses to the commercially available vibration damping adhesive tape. In some cases, different thicknesses were evaluated to demonstrate both increased vibration damping efficiency index and CLF. Specifically, a tape available from Avery Dennison under the designation UHA0806 was obtained and designated Sample A. The UHA0806 tape comprised an aluminum foil having a single layer of acrylic adhesive (as the viscoelastic damping material) at least partially disposed on one side of the aluminum foil. The UHA0806 tape was coated with a coating weight of 125 g / m 2 The total product mass per unit area of ​​the UHA0806 tape is 0.45 kg / m 2 This is the mass per unit area of ​​the complete tape (ie adhesive plus foil).

[0056] Another tape similar in construction to Sample A was obtained from Dynamic Control of North America, Inc. under the name DYNAMAT SUPERLITE and designated Sample B. The DYNAMAT SUPERLITE tape comprised a 0.06 mm aluminum foil and a single layer of adhesive (as a viscoelastic damping material) on one side of the foil. The DYNATMAT SUPERLITE tape utilized a relatively high coat weight of black butyl adhesive, with a total product mass per unit area of ​​1.50 kg / m 2 , and the total thickness is 1.10mm.

[0057] Preparation according to the present subject and having corresponding Figure 2 The belt of the configuration shown in FIG was designated as sample C, which had a 1.50 kg / m 2 The tape utilizes an acrylic adhesive for each of the two adhesive layers (as the viscoelastic damping material), each adhesive layer having a mass of 125 g / m 2 The tape has a coating weight of 0.125 mm and a thickness of 0.125 mm, with each adhesive layer having the same chemical composition. The tape also utilizes aluminum foil for each substrate, with each foil layer having a thickness of 0.250 mm.

[0058] Preparation according to the present subject and having corresponding Figure 2 The belt of the configuration shown in FIG was designed and designated as Sample D, which had a 1.50 kg / m 2 The tape utilizes an acrylic adhesive for each of the two adhesive layers (as the viscoelastic damping material), each adhesive layer having a mass of 125 g / m 2The tape has a coating weight of 0.125 mm and a thickness of 0.125 mm, with each adhesive layer having a different chemical composition. The tape also utilizes aluminum foil for each substrate, with each foil layer having a thickness of 0.250 mm.

[0059] Preparation according to the present subject and having corresponding Figure 2 The belt of the configuration shown in FIG was designated as Sample E, which had a 0.90 kg / m 2 The tape utilizes an acrylic adhesive for each of the two adhesive layers (as the viscoelastic damping material), each adhesive layer having a mass of 125 g / m 2 The tape also utilizes aluminum foil for each substrate, with each foil layer having a thickness of 0.125 mm.

[0060] Each of the tape samples A, B, C, D, and E was adhered to a component, which was then vibrated over a range of temperatures. A composite loss factor (CLF) was then determined for each system. As is known in the art, the CLF value is an indicator of the damping capacity of the tape (or other construction). Generally, the greater the CLF value at a given temperature, the greater the tape's ability to damp, or reduce, vibrations at that temperature. The CLF measurements for each sample were obtained from a vibrating beam test (VBT) using specification SAE J1637, with 0.75 mm thick Sendimizer steel as the base layer (component), and the results are reported at a reference frequency of 200 Hz.

[0061] like Figure 6 As evidenced by the graph of , tape Sample D exhibits higher CLF values ​​over a relatively wide temperature range as compared to currently available tapes, namely Samples A and B. Sample C exhibits a slightly higher peak CLF than Sample D and has a higher peak CLF than Sample B, and an overall higher peak CLF than Sample A over the temperature range evaluated. Sample E exhibits CLF values ​​comparable to Sample B. Samples C, D, and E are all thinner and lighter than Sample B or weigh the same as Sample B. The present subject matter allows for the construction of tapes having the same thickness and weight profile as currently available tapes, if not, a thinner and lighter profile having a wider and / or higher CLF value as a function of temperature (e.g., Figure 6 shown).

[0062] Another tape having a thickness and weight higher than Samples AE was obtained from Dynamic Control of North America, Inc. under the name DYNAMAT XTREME and designated Sample F. The DYNAMAT XTREME tape comprised a 0.10 mm aluminum foil and a single layer of adhesive on one side of the foil. The DYNAMAT XTREME tape utilized a relatively high coat weight black butyl adhesive and had a total product mass per unit area of ​​2.50 kg / m 2 , and the total thickness is 1.7mm.

[0063] Another tape of equal thickness and weight to Sample F was obtained from Sika Corporation under the designation SikaDamp 630 and designated Sample G. The SikaDamp 630 tape comprised a 0.08 mm aluminum foil and a single layer of adhesive on one side of the foil. The SikaDamp 630 tape utilized a relatively high coat weight black butyl adhesive, resulting in a total product mass per unit area of ​​2.00 kg / m 2 , and the total thickness is 1.5mm.

[0064] Preparation according to the present subject and having corresponding Figure 2 A tape having the configuration shown in FIG was prepared and designated as Sample H. The tape utilized an acrylic adhesive for each of the two adhesive layers, each adhesive layer having a thickness of 1.0 mm. The tape also utilized aluminum foil for each substrate, each foil layer having a thickness of 0.125 mm.

[0065] A tape according to the present subject matter and having a configuration consisting of two layers of Sample C was prepared and designated Sample I. The tape utilized an acrylic adhesive for each of the four adhesive layers (as the viscoelastic damping material) with a coating weight of 125 g / m 2 , and a thickness of 0.125 mm. The tape also utilizes aluminum foil for each of the four substrates, with each foil layer having a thickness of 0.25 mm.

[0066] like Figure 7As evidenced by the graph of , tape sample D exhibits comparable CLF values ​​over a relatively wide temperature range compared to currently available tapes, namely, samples F and G. However, sample D is thinner and lighter than samples F and G. Sample H has a higher CLF value than the CLF values ​​of currently available tapes, namely, samples F and G, over the entire temperature range studied. However, sample H has a mass per unit area comparable to that of samples F and G. Sample I exhibits the highest CLF maximum value of all samples studied. Thus, the present subject matter provides a damping construction that allows both higher CLF values ​​as a function of temperature and wider (or width-comparable) CLF values, the damping construction having reduced tape thickness and reduced tape mass per unit area.

[0067] Figure 8 A measure of damping efficiency calculated at 200 Hz as described herein is provided. Figure 8 A graph of the linear density normalized damping efficiency index (ζ) for samples A to G is provided. For the currently available samples (samples A, B, F, and G), the linear density normalized damping efficiency index (ζ) is less than about 4.5×10 3 For the disclosed products (Samples C, D, E, H, and I), the linear density normalized damping efficiency index (ζ) is greater than at least about 4.5×10 3 For products with more optimized surface density, maximizing temperature-dependent damping (ζ greater than at least about 4.5×10 3 ), the linear density normalized damping efficiency index increases. For example, sample A has a linear density normalized damping efficiency index (ζ) at about 0 because, despite being light, its peak CLF is less than 0.10 ( Figure 6 Although the effective fraction of CLF values ​​is greater than 0.10 (see Figure 7 ), sample F and sample G have a surface density of about 4.4×10 3 In contrast, samples C, D, and E have comparable or better damping (see Figure 6 ) and has ζ>1.12×10 4 , where the samples have a surface density reduction of about 50%. Similarly, comparing Samples H and I to an equal weight product of Samples F and G, Samples H and I have at least comparable, if not improved, damping as measured by the linear density normalized damping efficiency index (see Figure 7 and Figure 8 In some embodiments disclosed herein (not shown), samples with improved damping may have a value greater than at least 2.0×10 3 The linear density normalized damping efficiency index (ζ).

[0068] Many other benefits will undoubtedly become apparent from future applications and developments of this technology.

[0069] The present subject matter includes all operable combinations of features and aspects described herein. Thus, for example, if one feature is described in conjunction with one embodiment and another feature is described in conjunction with another embodiment, it is understood that the present subject matter includes embodiments having these feature combinations.

[0070] As described above, the present subject matter solves many problems associated with previous strategies, systems and / or devices. However, it should be understood that those skilled in the art may make various changes to the details, materials and arrangements of the components described and illustrated herein to explain the essence of the present subject matter without departing from the principles and scope of the claimed subject matter as expressed in the appended claims.

Claims

1. A belt for damping, comprising: a substrate defining a first side and an oppositely oriented second side; a first layer of viscoelastic damping material at least partially disposed on the first side of the substrate; and a second layer of viscoelastic damping material at least partially disposed on the second side of the substrate; The substrate has a thickness in a range of about 5 μm to about 3,000 μm, and each layer of the viscoelastic damping material has a thickness in a range of about 2 μm to about 5,000 μm. 2 . The tape of claim 1 , wherein at least one of the first substrate and the second substrate has a room temperature Young's modulus in a range of about 1 GPa to about 1000 GPa.

3. The tape of claim 1, wherein at least one of the first substrate and the second substrate has a room temperature Young's modulus in a range of about 20 GPa to about 500 GPa.

4. The tape of claim 1, wherein the substrate comprises a metal foil.

5. The tape of claim 4, wherein the metal foil is an iron foil.

6. The tape of claim 4, wherein the metal foil is a non-ferrous based foil.

7. The tape of claim 4, wherein the metal foil is a differential foil having a first region of ferrous foil and a second region of non-ferrous based foil.

8. The tape of claim 4, wherein the metal foil comprises aluminum.

9. The belt of claim 1 , wherein at least one of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material comprises a viscoelastic damping material selected from the group consisting of elastomers, butyl rubber, styrene block copolymers, polyurethanes, silicone rubbers, nitrile rubbers, isoprene, butadiene, viscoelastic polymer gels, pressure sensitive adhesives, non-pressure sensitive adhesives, and combinations thereof.

10. The belt of claim 1 , wherein the first layer of viscoelastic damping material and the second layer of viscoelastic damping material are each selected from the group consisting of elastomers, butyl rubber, styrene block copolymers, polyurethanes, silicone rubbers, nitrile rubbers, isoprene, butadiene, viscoelastic polymer gels, pressure sensitive adhesives, non-pressure sensitive adhesives, and combinations thereof.

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