Multi-layer tape

Abstract

To solve the problem that although vibration damping adhesive tapes are well known in the field, in order to attain a desired vibration damping characteristic, most such adhesive tapes are relatively thick, use a large amount of adhesives, and / or significantly increase a total weight of a system or an assembly that receives vibration, and therefore, there remains a need for an adhesive tape that damps or reduces vibration effectively, and is relatively thin and / or is light-weight.SOLUTION: A vibration damping viscoelastic damping material laminate is described. A tape (10) generally comprises at least two viscoelastic damping material layers (30, 50), and at least one substrate (40). The tape may optionally comprise one or more release liners (20, 60). A constraint layer system is also described that is formed by adhering the tape (10) to a first substrate and / or a second substrate that is subject to (that is, exposed to) vibration.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present subject matter relates to tapes, including adhesive tapes, for damping vibrations. [Background technology]

[0002] 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, use large amounts of adhesive, and / or significantly increase the overall weight of a system or assembly subjected to vibration. Thus, there remains a need for adhesive tapes that effectively dampen or reduce vibrations and are relatively thin and / or lightweight. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] (None in particular) Summary of the Invention

[0004] The problems and shortcomings associated with prior art approaches are addressed in the present invention as follows. In one aspect, the invention provides a tape for damping vibrations. The tape includes a substrate defining a first side and an oppositely directed second side. The tape also includes a first layer of viscoelastic damping material disposed at least partially on the first side of the substrate. The tape further includes a second layer of viscoelastic damping material disposed at least partially on the second side of the substrate. The substrate may have a thickness in the range of about 5 μm to about 3,000 μm, with each layer of viscoelastic damping material having a thickness in the range of about 2 μm to about 5,000 μm.

[0005] In another aspect, the present invention provides a tape for damping vibrations. The tape includes a first substrate and a second substrate. The tape also includes a first viscoelastic damping material layer at least partially disposed between the first substrate and the second substrate. Additionally, the tape further includes a second viscoelastic damping material layer. The second substrate is at least partially disposed between the first viscoelastic damping material layer and the second viscoelastic damping material layer. The first substrate and the second substrate each have a thickness in the range of about 5 μm to about 3,000 μm. The first viscoelastic damping material layer and the second viscoelastic damping material layer each have a thickness in the range of about 2 μm to about 5,000 μm.

[0006] In yet another aspect, the present invention provides a constraining layer system comprising at least one of a first component and a second component (also referred to as a surface) undergoing vibration. The first component and / or the second component may be composed of any material requiring damping, including, but not limited to, metal, plastic, and wood. The tape described herein is disposed at least partially between the first component and the second component. The system also comprises a vibration damping tape comprising (i) a substrate defining a first surface and an oppositely directed second surface, (ii) a first viscoelastic damping material layer disposed at least partially on the first surface of the substrate, and (iii) a second viscoelastic damping material layer disposed at least partially on the second surface of the substrate. The substrate has a thickness in the range of about 5 μm to about 3,000 μm, and the viscoelastic damping material layers each have a thickness in the range of about 2 μm to about 5,000 μm. At least one of the first viscoelastic damping material layer and the second viscoelastic damping material layer are adhered to at least one of the first component and the second component.

[0007] In yet another aspect, the present invention provides a constrained layer system comprising at least one of a first component and a second component undergoing vibration, the system comprising: (i) a first substrate; (ii) a second substrate; and (iii) a substrate disposed at least partially between the first substrate and the second substrate. The vibration damping tape also includes (i) a first viscoelastic damping material layer, and (ii) a second viscoelastic damping material layer, the second substrate being at least partially disposed between the first viscoelastic damping material layer and the second viscoelastic damping material layer. The first substrate and the second substrate each have a thickness in the range of about 5 μm to about 3,000 μm. The first viscoelastic damping material layer and the second viscoelastic damping material layer each have a thickness in the range of about 2 μm to about 5,000 μm. At least one of the first viscoelastic damping material layer and the second viscoelastic damping material layer is at least partially adhered to at least one of the first component and the second component.

[0008] As will be realized, the subject matter described herein is capable of other and different embodiments, and its several details are capable of modification in various respects, all without departing from the scope of the claims. Accordingly, the drawings and description are to be regarded as illustrative and not restrictive. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of one embodiment of a viscoelastic damping material laminate or tape according to the present invention; [Diagram 2] 2 is a schematic cross-sectional view of another embodiment of a viscoelastic damping material laminate or tape according to the present invention. [Diagram 3] FIG. 2 is a schematic cross-sectional view of a constraining layer system using the tape of FIG. 1. [Figure 4] FIG. 2 is a schematic cross-sectional view of a constraining layer system using the tape of FIG. 1. [Diagram 5] FIG. 3 is a schematic cross-sectional view of a constraining layer system using the tape of FIG. 2. [Figure 6] 1 is a graph of composite loss factor as a function of temperature for a tape according to the present invention compared to two prior art tapes. [Figure 7] 1 is a graph of composite loss factor as a function of temperature for a tape according to the present invention compared to two prior art tapes. [Figure 8]1 is a graph of the linear density normalized attenuation efficiency index of a tape according to the present invention compared to a commercially available tape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The subject matter provides viscoelastic damping material laminates (also referred to herein as "tapes") that exhibit relatively high vibration damping properties, which may be described as damping efficiency as described herein. In certain types of tapes, the tapes are relatively thin and / or lightweight as 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 layers of viscoelastic damping material and an optional release liner at least partially disposed on the surface of the viscoelastic damping material. In some embodiments, the tapes may include additional viscoelastic damping layers. In one embodiment, the tapes may include at least three layers of both viscoelastic damping material and a substrate at least partially disposed on the surface of the viscoelastic damping material surface. In some embodiments, the tapes may include at least four layers of both viscoelastic damping material and a substrate at least partially disposed on the surface of the viscoelastic damping material surface. In some embodiments, the tapes may include at least five layers of both viscoelastic damping material and a substrate at least partially disposed on the surface of the viscoelastic damping material surface. In some embodiments, the tape may include at least six layers of both viscoelastic damping material and a substrate at least partially disposed on the surface of the viscoelastic damping material face. While many of the embodiments described herein show first and second viscoelastic damping material layers, any additional layers may also have these embodiments. In still other embodiments, the viscoelastic damping material may exhibit at least one compositional gradient or region, such as along the thickness of the viscoelastic damping material.

[0011] In some embodiments, the compositional gradient or region extends from one surface of the viscoelastic damping material to A graded change in material properties may be imparted to the other surface. Additional viscoelastic damping layers may be disposed on top of one another or on at least one of the substrates. The present invention also provides a constraining layer system utilizing a viscoelastic damping material laminate.

[0012] [Base material] The tapes of the present invention utilize one or more substrates. Although specific embodiments of single substrate tapes and dual substrate tapes are described herein, it is understood that the tapes of the present invention include tapes 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. In some embodiments, the substrates are multi-layered and may be disposed at least partially on top of each other. In tapes utilizing multiple substrates, typically a layer of viscoelastic damping material is disposed at least partially between adjacent substrates. For example, in one embodiment of the present invention, a tape is provided that includes five substrates, in which a layer of viscoelastic damping material is disposed at least partially between adjacent substrates and a fifth layer of viscoelastic damping material is disposed at least partially along one surface of the outermost substrate.

[0013] The substrates used in the viscoelastic damping material laminates of the present invention are relatively thin, i.e., have 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 some embodiments about 125 μm or about 250 μm. In some embodiments, the substrate has a room temperature Young's modulus in the range of about 1 GPa to about 1000 GPa, in other embodiments about 20 GPa to about 500 GPa, and in some embodiments about 40 GPa to about 200 GPa. In some embodiments, the substrate is a metal foil that may have a room temperature Young's modulus of at least 20 GPa.

[0014] In many embodiments, the substrate may consist of or be in the form of a metal foil. In some embodiments, there may be more than one substrate metal foil (which may be referred to as a first metal foil, a second metal foil, a third metal foil, etc.). In general, any metal foil (including a first metal foil, a second metal foil, a third metal foil, etc.) may be used, including ferrous and non-ferrous foils. A wide range of metals may be used, including, 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 agents. In many embodiments, aluminum foil is used. However, other metals may be used, including columbium / niobium, hafnium, iridium, molybdenum and alloys, rhenium and alloys, tantalum, tungsten and alloys, platinum, platinum and iridium, Alloy 42 and 52, Hastelloy, Inconel, Invar 36®, Kovar, etc. It is contemplated that other metals and / or combinations of metals may be used, including .TM., Monel, Nichrome / Tophet "A", phosphor bronze, titanium, vanadium, zirconium, and combinations thereof.

[0015] The present invention may include the use of coated metal foils and metal foils that include 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 utilized 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 include a metallized film.

[0016] The present invention may also include other materials for the substrate, such as heterogeneous layers or regions. In some embodiments, the substrate may comprise one or more adjuvants dispersed in a matrix material. The adjuvants may be in the form of, for example, particles, platelets, fibers, geometrically shaped materials, and / or sheet-like regions of a first material that differs in chemical composition from the matrix material. A particular example of a heterogeneous layer is a carbon fiber film. In another embodiment, the heterogeneous layer may include a polymer composite having at least one layer of fiberglass or carbon fiber. In one example, the fiberglass may be impregnated with an epoxy. In another example, the fiberglass may be FR-4 (also known as FR4). In some embodiments, the choice of adjuvant and matrix material, as well as the degree of dispersion of the adjuvant within the matrix material, allows for detailed tailoring of the physical properties and characteristics of a heterogeneous layer that may be used as a substrate. In still other embodiments, the substrate may utilize a foil that exhibits a compositional gradient or region, such as along the thickness of the foil. In some embodiments, the compositional gradient or region may provide a gradual change in material properties from one surface to the other. The metal foil may be a differential foil having a first ferrous region of ferrous foil and a second region of non-ferrous foil. In some embodiments, Thus, a foil having two or more regions of an iron or iron-based composition in combination with two or more regions of a non-ferrous or non-ferrous composition can be used.

[0017] [Viscoelastic damping material] Each viscoelastic damping material layer used in the viscoelastic damping material laminate of the present invention is relatively thin. In many embodiments, the relatively thin viscoelastic damping material laminate may have a thickness in the range of about 2 μm to about 5,000 μm, in many embodiments about 10 μm to about 1,000 μm, and in some embodiments about 125 μm. In some embodiments, at least one of the first viscoelastic damping material layer and the second viscoelastic damping material layer may comprise a viscoelastic damping material selected from the group including, but not limited to, elastomers, butyl rubber, styrenic block copolymers (known as SBC, e.g., Kraton), polyurethane, silicone rubber, nitrile rubber, isoprene, butadiene, viscoelastic polymer gels, pressure sensitive adhesives (e.g., silicone, rubber, acrylic), non-pressure sensitive adhesives, asphalt materials (e.g., roofing adhesives and mastics), and combinations thereof. In many embodiments, these viscoelastic damping materials may have both temperature and frequency dependent moduli that may provide efficient damping near their glass transition temperatures. In other embodiments, both the first and second viscoelastic damping material layers may comprise a viscoelastic damping material selected from the group including, but not limited to, elastomers, butyl rubber, styrenic block copolymers (known as SBC, e.g., Kraton), polyurethane, silicone rubber, nitrile rubber, isoprene, butadiene, viscoelastic polymer gels, pressure sensitive adhesives (e.g., silicone, rubber, acrylic), non-pressure sensitive adhesives, asphalt materials (e.g., roofing adhesives and mastics), and combinations thereof. In many embodiments, these viscoelastic damping materials may have both a temperature and frequency dependent modulus that may provide efficient damping near their glass transition temperatures. In many embodiments, the viscoelastic damping material may have a tan delta maximum of greater than about 0.5 at the temperature and frequency of the damping application. In some embodiments, The temperature range as measured by dynamic mechanical analyzer (DMA) at 10 rad / s can be about -120°C to about 200°C, in many embodiments, -80°C to about 100°C, and in some embodiments, about -60°C to about 75°C.

[0018] The viscoelastic damping materials used in the tapes of the present invention may exhibit viscoelastic properties at temperatures corresponding to the application of the tape. Generally, the tapes are used and / or designed for applications within a temperature range of -30° C. to 150° C. In some embodiments, the present invention also includes tapes for use at temperatures that may be below -30° C. and / or above 150° C.

[0019] In many embodiments, the adhesive comprises a pressure sensitive adhesive (PSA). However, the present invention may also include the use of adhesives that are not pressure sensitive adhesives, i.e., "non-PSA." For example, non-pressure sensitive adhesives may include, but are not limited to, heat seal adhesives, thermal bond films, B-stage adhesives, two-stage adhesives, dry adhesives, and combinations thereof.

[0020] Pressure sensitive adhesive materials that can be used in the vibration damping adhesive tape include rubber adhesives, acrylic adhesives, vinyl ether adhesives, silicone adhesives, and / or mixtures of two or more thereof, see "Adhesion and Bonding", Encyclopedia of Polymers, the disclosure of which is incorporated herein by reference. Examples of pressure-sensitive adhesive materials include those described in Science and Engineering, Vol.1, pages 476-546, Interscience Publishers, 2nd Ed.1985. Pressure-sensitive adhesive materials may include adhesive polymers such as natural, reclaimed or styrene-butadiene rubber, tackified natural or synthetic rubber, styrene-butadiene or styrene-isoprene block copolymers, random copolymers of ethylene and vinyl acetate, ethylene-vinyl-acrylic terpolymers, polyisobutylene, poly(vinyl ether), poly(acrylic) esters, etc. Pressure-sensitive rubber and acrylic adhesive materials are typically characterized by a glass transition temperature in the range of about -70°C to about 20°C. Pressure-sensitive silicone adhesive materials are typically characterized by a glass transition temperature in the range of about -20°C to about 100°C.

[0021] The acrylic adhesive may include as its main components acrylic polymers containing carboxylic acids, which are obtained from vinyl monomers containing carboxyl groups, such as acrylic acid, methacrylic acid, and acrylic polymers containing hydroxyl groups, which are obtained from vinyl monomers containing hydroxyl groups, such as 2-hydroxyethyl methacrylate. In one embodiment, the acrylic adhesive material is obtained from the copolymerization of an alkyl acrylate, such as butyl acrylate, 2-ethylhexyl acrylate, or isononyl acrylate, with a polar monomer, such as acrylic acid, acrylamide, or N-vinyl-2-pyrrolidone, and another monomer, such as an acrylate, methacrylate, styrene, vinyl acetate, other than the above acrylates.

[0022] In addition to the resins mentioned above, other materials may be included in the pressure sensitive adhesive material. These may include, but are not limited to, solid tackifying resins, liquid tackifiers (often called plasticizers), antioxidants, fillers, pigments, waxes, etc. The adhesive material may contain a mixture of solid and liquid tackifying resins (or liquid plasticizers).

[0023] In many embodiments, the viscoelastic damping materials, in addition to improved vibration damping properties, exhibit beneficial adhesive properties such as those found in certain automotive applications, such as relatively high adhesion, good shear resistance, good heat resistance, good chemical resistance, resistance to environmental factors including weathering and UV light, good holding power, adhesion to low surface energy substrates, and adhesion to soiled surfaces such as dirty or oily surfaces.

[0024] In some embodiments, the first and second viscoelastic damping material layers of the present invention can have the same chemical composition. In other embodiments, the first and second viscoelastic damping material layers of the present invention can utilize different chemical compositions. In other embodiments, all layers of viscoelastic damping material (if there are at least three layers of viscoelastic damping material) can have the same chemical composition. In another embodiment, all layers of viscoelastic damping material (if there are at least three layers of viscoelastic damping material) can have different chemical compositions.

[0025] The viscoelastic damping material layer (referring to both the first and second viscoelastic damping material layers) in the tapes of the present invention can be continuous or substantially continuous. In many embodiments, the viscoelastic damping material layer is continuous and exhibits a uniform thickness. In some embodiments, the viscoelastic damping material layer can be substantially continuous where the layer cannot be uniform, such as due to unintentional imperfections or voids.

[0026] [Release liner] The viscoelastic damping material laminate of the present invention optionally includes one or more release liners at least partially covering or disposed on the viscoelastic damping material layer. Generally, in many embodiments, a first release liner is a first release liner of the viscoelastic damping material. The first release liner is disposed at least partially on and covers the face of the layer. Optionally, a second release liner may be disposed at least partially on and covers the face of the second viscoelastic damping material layer. The invention includes the use of multi-component (or multi-element) release liner assemblies, such as multiple release liners that at least partially cover areas of the viscoelastic damping material layer that are otherwise exposed. In some embodiments, the tape may include multiple release liners, a single release liner, or no release liner.

[0027] The release liner used in the present invention may be any release liner known in the art. A variety of release liners are available that may be applied to the viscoelastic damping material and are useful for protecting the viscoelastic damping material from inadvertent bonding prior to use. Suitable release liners are described in the Handbook of Pressure These are described in some detail in Chapter 23 of Sensitive Adhesive Technology, 2nd Ed. A variety of release liners known in the art are suitable, so long as they are selected for their release characteristics with respect to the viscoelastic damping material selected for use in the present invention.

[0028] [Composite loss factor and damping efficiency] As provided herein, damping performance may be measured using CLF (composite loss factor) over a temperature range at a reference frequency of at least 50 Hz. In some embodiments, 200 Hz may be used as the reference frequency. In some embodiments, a laminate structure may be considered damped when the CLF is at least 0.10 at a frequency of 200 Hz in the temperature range of the application. The temperature range of the application may be from about -50°C to about 200°C. In some embodiments, a laminate structure may be considered damped when the CLF is at least 0.05 when measured over a temperature range of 15°C at a frequency of 200 Hz. As described herein, the span for the 15°C temperature range may occur from about -50°C to about 200°C. In other embodiments, a laminate structure may be considered damped when the CLF is at least 0.10 when measured over a temperature range of 15°C at a frequency of 200 Hz, and the span for the 15°C temperature range may occur from about -50°C to about 200°C.

[0029] In other embodiments, the damping properties of the laminate structure may be based on a Damping Efficiency Index (discussed below). In one embodiment, the laminate structure may have a Damping Efficiency Index of at least greater than 2000 at frequencies of at least about 50 Hz. In another embodiment, the laminate structure may have a Damping Efficiency Index of at least greater than 2000 at frequencies of about 50 Hz to about 5000 Hz.

[0030] As used herein, damping efficiency is a measure of the height and width of a composite loss factor (CLF) normalized by its thickness and mass. For damping efficiency, the linear density normalized damping efficiency index ζ=(W×M) / (ρ A The performance of various tapes can be evaluated using the formula: ρ × t (unit: °C / (kg / m)), where W is the width of the CLF curve for CLF ≥ 0.10 (°C), M is the maximum CLF value measured, and ρ A is the mass per unit area (kg / m 2 ), where t is the thickness of the entire structure (m). In some embodiments of what is disclosed herein, the samples with improved attenuation have a .lambda. of at least 2.0×10 3 The linear density normalized attenuation efficiency factor (ζ) may be greater than or equal to

[0031] [drawing] 1 is a schematic cross-sectional view of one embodiment of a tape 10 according to the present invention. Tape 10 comprises a substrate 40 defining a first side 42 and an oppositely oriented second side 44. Tape 10 also comprises a first layer of viscoelastic damping material 30 disposed at least partially on or along the first side 42 of substrate 40. Tape 10 further comprises a second layer of viscoelastic damping material 50 disposed at least partially on or along the second side 44 of substrate 40. The loop 10 may also include one or more optional release liners, such as a release liner 20 disposed at least partially on and covering the first viscoelastic damping material layer 30 and / or a release liner 60 disposed at least partially on and covering the second viscoelastic damping material layer 50.

[0032] 2 is a schematic cross-sectional view of another embodiment of a tape 100 according to the present invention. Tape 100 comprises a first substrate 110, a second substrate 130, a first viscoelastic damping material layer 120 disposed at least partially between the first substrate 110 and the second substrate 130, and a second viscoelastic damping material layer 140. Second substrate 130 is disposed at least partially between the first viscoelastic damping material layer 120 and the second viscoelastic damping material layer 140. Tape 100 also comprises an optional release liner 150 disposed at least partially on or along the second viscoelastic damping material layer 140.

[0033] [Tape form] The tapes of the present invention can be provided in a variety of different forms, in many embodiments the tapes are provided in roll form, although other forms such as sheet form and Z-fold form are included.

[0034] [Applications and Constraint Layer Systems] As described, the tapes of the present invention find wide application for damping vibrations. When applied, i.e., adhered to a first component, a constraining layer system is formed. The tapes of the present invention may be affixed (i.e., adhered) to an optional second component. When the first component and any second component are subjected to vibrations, the tape, and in particular the viscoelastic damping material layer of the tape, dampens or reduces the vibrations. While not wishing to be limited to any particular frequency or frequency range, the tapes of the present invention are used to damp vibrations of at least 50 Hz. In other embodiments, the tapes of the present invention may dampen vibrations within a frequency range of about 50 Hz to about 15,000 Hz, more typically about 100 Hz to about 5,000 Hz, and in certain applications, about 200 Hz to about 3,000 Hz.

[0035] The tapes of the present invention can potentially be used in any application where it is desired to damp vibrations by adhering the tape to a first and optionally a second component of a system that exhibits or receives vibrations to form a constrained layer system. The tapes of the present invention can potentially be used in any application where it is desired to damp vibrations by adhering (i.e., attaching) the tape to at least one of a first and a second component of a system that exhibits or receives vibrations to form a constrained layer system. Non-limiting examples include automotive applications, electronic applications, incorporation into power tools, aerospace applications, incorporation into 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 components including brake pads and brake shims, roofs, floors, heat shields, frames and frame components, firewalls, and suspension components. A non-limiting example of an electronic application is the damping of vibrations associated with hard disk drives (HDDs).

[0036] Figures 3 and 4 are schematic cross-sectional views of a constraining layer system using tape 10, as described above in connection with Figure 1. Constraining layer system 210 shown in Figure 3 comprises tape 10 (comprising substrate 40, first adhesive layer 30 and second adhesive layer 50) with one of its release liners removed (e.g., release liner 60 shown in Figure 1) and tape 10 is at least partially adhered via viscoelastic damping material layer 50 to a second component 70 that is subject to vibrations or potential vibrations to be damped. Constraining layer system 212 shown in Figure 4 comprises tape 10 with both of its release liners removed (e.g., release liners 20 and 60 shown in Figure 1) and tape 10 is at least partially adhered via viscoelastic damping material layer 50 to a second component 70 that is subject to vibrations or potential vibrations to be damped. 3 and 4, the first component 80 and / or the second component 70 are bonded via a second viscoelastic damping material layer 50 to a second component 70 that is subject to the generated or potential vibrations, and via a first viscoelastic damping material layer 30 to a first component 80 that is subject to the vibrations or potential vibrations. With further reference to FIG. 4, it will be appreciated that the first component 80 and / or the second component 70 may be in the form of a sound absorbing material such as foam in many applications. The resulting assembly provides both vibration damping and sound absorption. It will also be appreciated that in FIGS. 3 and 4, additional substrate and / or adhesive layers may be added.

[0037] FIG. 5 is a schematic cross-sectional view of a constraining layer system using tape 100, as described above in connection with FIG. 2. Constraining layer system 300 comprises tape 100 with its release liner removed (e.g., release liner 150 shown in FIG. 2), and tape 100 is adhered to a second component 170 that is subject to vibrations or potential vibrations to be damped via a second adhesive layer 140 (also referred to herein as a second viscoelastic damping material layer). In FIG. 5, the first substrate (110) is exposed and is not adhered or bonded to another substrate, viscoelastic damping material, or component. Conversely (but not shown in FIG. 5), the tape may be adhered to a first component that is subject to vibrations or potential vibrations to be damped via a first adhesive layer (also referred to herein as a first viscoelastic damping material layer) when the second substrate is exposed and is not adhered or bonded to another substrate, viscoelastic damping material, or component. It is also understood that additional substrate and / or adhesive layers may be added in FIG. 5, where the substrate is still exposed and is not adhered or bonded to another substrate, viscoelastic damping material, or component.

[0038] The embodiments described in Figures 1-5 provide examples of the configurations described herein. It is understood that the invention can include tapes with additional substrates, including three substrates, four substrates, five substrates, and more than six substrates. The additional substrates can be disposed on top of each other or on at least one viscoelastic damping layer. It is also understood that the invention can include tapes with additional viscoelastic damping layers, including three viscoelastic damping material layers, four viscoelastic damping material layers, five viscoelastic damping material layers, or more than six viscoelastic damping material layers. The additional viscoelastic damping layers can be disposed on top of each other or on at least one substrate.

[0039] Figures 6, 7 and 8 are illustrated in the Examples below.

[0040] [Examples] The vibration damping properties of several adhesive tapes according to the present invention were compared to the vibration damping properties of a commercially available vibration damping adhesive tape. The laminates described herein were evaluated against the commercially available vibration damping adhesive tape in some embodiments at similar thicknesses. In some examples, various thicknesses were evaluated to demonstrate an increase in both the vibration damping efficiency index and the CLF. Specifically, a tape sold by Avery Dennison under the name UHA0806 was obtained and designated Sample A. The UHA0806 tape comprises an aluminum foil having a single layer of an acrylic adhesive (as a viscoelastic damping material) at least partially disposed on one side of the aluminum foil. The UHA0806 tape is a 125 g / m 2 The adhesive layer coat weight is 0.25mm, and the total product mass per unit area of ​​UHA0806 tape is 0.45kg / m 2 This is the mass per unit area of ​​the entire tape, i.e. adhesive and foil.

[0041] Another tape similar in construction to Sample A was obtained, designated DYNAMAT SUPERLITE by Dynamic Control of North America, Inc. and designated Sample B. The DYNAMAT SUPERLITE tape comprises 0.06 mm aluminum foil and a single layer of adhesive (as the viscoelastic damping material) on one side of the foil. The DYNAMAT SUPERLITE tape utilizes a relatively high coat weight black butyl adhesive, resulting in a total product mass per unit area of ​​1.50 kg / m. 2 , total thickness is 1.10 mm.

[0042] In accordance with the present invention, a tape having a construction corresponding to that shown in Figure 2 was produced and designated Sample C. Sample C had a strength of 1.50 kg / m 2 The tape utilizes an acrylic adhesive in each of the two adhesive layers (as the viscoelastic damping material), with each adhesive layer having a weight of 125 g / m 2 and a thickness of 0.125 mm, with each adhesive layer having the same chemical composition. The tapes also utilized aluminum foil for each substrate, with each foil layer having a thickness of 0.250 mm.

[0043] In accordance with the present invention, a tape having a construction corresponding to that shown in Figure 2 was produced and designated Sample D. Sample D had a strength of 1.50 kg / m 2 The tape utilizes an acrylic adhesive in each of the two adhesive layers (as the viscoelastic damping material), with each adhesive layer having a weight of 125 g / m 2 and a thickness of 0.125 mm, with each adhesive layer having a different chemical composition. The tapes also utilized aluminum foil for each substrate, with each foil layer having a thickness of 0.250 mm.

[0044] In accordance with the present invention, a tape having a construction corresponding to that shown in Figure 2 was prepared and designated Sample E. Sample E had a strength of 0.90 kg / m 2 The tape utilizes an acrylic adhesive in each of the two adhesive layers (as the viscoelastic damping material), with each adhesive layer having a weight of 125 g / m2 and a thickness of 0.125 mm. The tapes also utilized aluminum foil for each substrate, with each foil layer having a thickness of 0.125 mm.

[0045] Each of the tape samples A, B, C, D, and E was adhered to a part and then the part was subjected to vibration over a range of temperatures. The composite loss factor (CLF) of each system was then determined. As known in the art, the CLF value is an indication of the damping ability of a tape (or other structure). Generally, the higher the value of CLF at a given temperature, the greater the ability of the tape to dampen or reduce vibration at that temperature. The CLF measurements for each sample were obtained from a Vibrating Beam Test (VBT) using SAE J1637 standard with 0.75 mm thick Sendimizer steel as the base layer (component) and the results are reported at a reference frequency of 200 Hz.

[0046] As is evident from the graph of FIG. 6, Tape Sample D exhibited higher CLF values ​​over a relatively wide range of temperatures compared to the currently available tapes, i.e., Samples A and B. Sample C exhibited a slightly higher peak CLF than Sample D, had a higher peak CLF than Sample B, and had a higher CLF overall over the temperature range evaluated than Sample A. Sample E exhibited CLF values ​​comparable to that of Sample B. Samples C, D, and E are all no thinner and no heavier than Sample B. The present invention allows for the construction of tapes with thickness and weight profiles comparable, if not thinner and lighter, to currently available tapes with wider and / or higher CLF values ​​as a function of temperature (as seen in FIG. 6).

[0047] Another tape, thicker and heavier than Samples A-E, was obtained from Dynamic Control of North America, Inc., designated DYNAMAT XTREME and designated Sample F. The DYNAMAT XTREME tape contains a 0.10 mm aluminum foil and a single layer of adhesive on one side of the foil. XTREME tape utilizes a relatively high coat weight black butyl adhesive, resulting in a total product mass per unit area of ​​2.50kg / m 2 , the total thickness is 1.7 mm.

[0048] Another tape of similar thickness and weight to Sample F, designated SikaDamp 630 by Sika Corporation, was obtained and designated Sample G. The p630 tape contains 0.08mm aluminium foil and a single layer of adhesive on one side of the foil. SikaDamp630 tape utilises a relatively high coat weight black butyl adhesive, resulting in a total product mass per unit area of ​​2.00kg / m 2 , the total thickness is 1.5 mm.

[0049] In accordance with the present invention, a tape having a configuration corresponding to that shown in Figure 2 was made and designated 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.

[0050] In accordance with the present invention, a tape having the two-ply construction of Sample C was prepared and designated Sample I. The tape utilized an acrylic adhesive in each of the four adhesive layers (as the viscoelastic damping material), each adhesive layer having a coat weight of 125 g / m2. 2 , having a thickness of 0.125 mm. The tape also utilized aluminum foil for each of the four substrates, with each foil layer having a thickness of 0.25 mm.

[0051] As is evident from the graph of FIG. 7, Tape Sample D exhibits comparable CLF values ​​over a relatively wide range of temperatures compared to the currently available tapes, i.e., Samples F and G. However, Sample D is thinner and lighter than Samples F and G. Sample H has a higher CLF value over the entire temperature range tested than the currently available tapes, i.e., Samples F and G. However, Sample H has a mass per unit area comparable to Samples F and G. Sample I exhibits the highest CLF maximum value of all the samples tested. Thus, the present invention provides a damping structure with a thinner tape thickness and less tape mass per unit area that allows both higher CLF values ​​as well as a wider (or comparable) CLF value as a function of temperature.

[0052] Figure 8 provides a measure of damping efficiency calculated at 200 Hz as described herein. Figure 8 provides a plot of the linear density normalized damping efficiency index (ζ) for Samples A through I. For the currently available samples (Samples A, B, F, and G), the linear density normalized damping efficiency index (ζ) is approximately 4.5×10 3 For the disclosed products (Samples C, D, E, H, and I), the linear density normalized attenuation efficiency index (ζ) is at least about 4.5×10 3 Products with a surface density more optimized for maximum temperature-dependent damping (ζ of at least about 4.5×10 3 For samples with a CLF greater than 0.10 (see FIG. 6), the linear density-normalized attenuation efficiency index (ζ) increases. For example, despite its light weight, sample A has a linear density-normalized attenuation efficiency index (ζ) of about 0 because its peak CLF is less than 0.10 (see FIG. 6). Samples F and G have a significant portion with CLF values ​​greater than 0.10 (see FIG. 7), but because of their relatively high surface densities, the linear density-normalized attenuation efficiency index (ζ) is about 4.4×10 3 In comparison, samples C, D, and E have similar or higher attenuation (see Figure 6), so the ζ is 1.12 × 10 4The samples have a larger ζ and have a surface density reduction of about 50%. Similarly, when comparing Samples H and I to comparable heavy products such as Samples F and G, Samples H and I have at least similar, if not improved, attenuation as measured by the Linear Density Normalized Attenuation Efficiency Index (see Figures 7 and 8). In some embodiments (not shown) disclosed herein, the samples with improved attenuation have at least 2.0 x 10 3 It may have a larger linear density normalized attenuation efficiency index (ζ).

[0053] Many other advantages will no doubt become apparent from the future use and development of this technology.

[0054] The present invention includes all practicable combinations of the features and aspects described herein. Thus, for example, if one feature is described in connection with an embodiment and another feature is described in connection with another embodiment, it is understood that the invention includes embodiments having combinations of those features. It is understood.

[0055] As noted above, the present invention overcomes many of the problems associated with previous methods, systems and / or apparatus. However, it will be recognized that various changes in the details, materials and arrangements of the components described and illustrated herein to illustrate the nature of the invention may be made by those skilled in the art without departing from the principles and scope of the claimed subject matter, as set forth in the appended claims. [Explanation of symbols]

[0056] [Figure 1, etc.] 10 Tape 20 Release Liner 30 First viscoelastic damping material layer 40 Base material 42 First surface of the substrate (40) 44 Second surface of the substrate (40) 50 Second viscoelastic damping material layer 60 Release Liner [Figure 2, etc.] 100 Tape 110 First base material 120 First viscoelastic damping material layer 130 Second base material 140 Second viscoelastic damping material layer 150 Release Liner [Other figures] 70 Second Component 80 First Component 170 Second Component 210 Constrained Layer System 212 Constrained Layer System 300 Constrained Layer System

Claims

1. A damping tape comprising: A first substrate (110); A second substrate (130); a first layer of viscoelastic damping material (120) disposed at least partially between the first substrate and the second substrate; a second viscoelastic damping material layer (140), the second substrate being at least partially disposed between the first viscoelastic damping material layer and the second viscoelastic damping material layer; Equipped with the first substrate and the second substrate each have a thickness in the range of 5 μm to 3,000 μm, the first viscoelastic damping material layer and the second viscoelastic damping material layer each have a thickness in the range of 2 μm to 5,000 μm; each of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material having a first surface and a second surface; 11. A damping tape comprising: a first viscoelastic damping material layer, a second viscoelastic damping material layer, or both, having a composition gradient that provides a gradual change in material properties from a first surface of the viscoelastic damping material layer to a second surface of the viscoelastic damping material layer.

2. 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 the range of 1 GPa to 1000 GPa.

3. 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 the range of 20 GPa to 500 GPa.

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

5. 5. The tape of claim 4, wherein at least one of the first metal foil and the second metal foil is an iron-based foil.

6. 5. The tape of claim 4, wherein at least one of the first metal foil and the second metal foil is a non-ferrous foil.

7. 5. The tape of claim 4, wherein at least one of the first metal foil and the second metal foil is a differential foil having a first ferrous composition region and a second non-ferrous composition region.

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

9. 5. The tape of claim 4, wherein the second metal foil comprises aluminum.

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

11. 2. The tape of claim 1, wherein both the first viscoelastic damping material layer and the second viscoelastic damping material layer are selected from the group including elastomers, butyl rubber, styrenic block copolymers, polyurethanes, silicone rubbers, nitrile rubbers, isoprene, butadiene, viscoelastic polymer gels, pressure sensitive adhesives, non-pressure sensitive adhesives, and combinations thereof.

12. 11. The tape of claim 10, wherein the pressure sensitive adhesive comprises an acrylic adhesive, a silicone adhesive, a rubber adhesive, a vinyl ether adhesive, and combinations thereof.

13. The tape of claim 1 , wherein both the first layer of viscoelastic damping material and the second layer of viscoelastic damping material comprise an acrylic adhesive.

14. The tape of claim 1 , wherein the first layer of viscoelastic damping material and the second layer of viscoelastic damping material have the same chemical composition.

15. The tape of claim 1 , wherein the first layer of viscoelastic damping material and the second layer of viscoelastic damping material have different chemical compositions.

16. The tape of claim 1 , wherein at least one of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material is substantially continuous.

17. and further comprising at least one release liner at least partially disposed on at least one of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material.

2. The tape of claim 1.

18. The tape of claim 1, further comprising a release liner (150) at least partially disposed on the second viscoelastic damping material layer.

19. The tape of claim 1 further comprising an additional substrate.

20. The tape of claim 1 further comprising an additional viscoelastic damping layer.

21. The tape of claim 1, having a CLF of at least 0.05 at 200 Hz over a range of 15°C.

22. The tape of claim 1, having a CLF of at least 0.10 at 200 Hz over a range of 15°C.

23. A linear density normalized attenuation efficiency index (ζ) of at least 2.0 × 10 at 200 Hz. ３ The tape of claim 1 .

24. A linear density normalized attenuation efficiency index (ζ) of at least 4.5 × 10 at 200 Hz. ３ The tape of claim 1 .

25. 1. A constrained layer system comprising: At least one of a first component and a second component that are subjected to vibration; A vibration damping tape (100), comprising: (i) a first substrate (110); (ii) a second substrate (130); and (iii) a first layer of viscoelastic damping material (120) disposed at least partially between the first substrate and the second substrate; (iv) a second viscoelastic damping material layer (140), the second substrate being at least partially disposed between the first viscoelastic damping material layer and the second viscoelastic damping material layer; and wherein the first substrate and the second substrate each have a thickness in the range of 5 μm to 3,000 μm, and the first viscoelastic damping material layer and the second viscoelastic damping material layer each have a thickness in the range of 2 μm to 5,000 μm; each of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material having a first surface and a second surface; a vibration damping tape, wherein the first viscoelastic damping material layer or the second viscoelastic damping material layer, or both, have a composition gradient that provides a gradual change in material properties from a first surface of the viscoelastic damping material layer to a second surface of the viscoelastic damping material layer; Equipped with A constraining layer system, wherein 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.

26. 26. The constraining layer system of claim 25, wherein at least one of the first substrate and the second substrate has a room temperature Young's modulus in the range of 1 GPa to 1000 GPa.

27. 26. The constraining layer system of claim 25, wherein at least one of the first substrate and the second substrate has a room temperature Young's modulus in the range of 20 GPa to 500 GPa.

28. 26. The constraining layer system of claim 25, wherein at least one of the first substrate and the second substrate comprises a metal foil.

29. 30. The constraining layer system of claim 28, wherein the metal foil is an iron-based foil.

30. 30. The constraining layer system of claim 28, wherein the metal foil is a non-ferrous foil.

31. 30. The constraining layer system of claim 28, wherein the metal foil is a differential foil having a first ferrous composition region and a second non-ferrous composition region.

32. 30. The constraining layer system of claim 28, wherein the metal foil comprises aluminum.

33. 26. The constraining layer system of claim 25, wherein at least one of the first viscoelastic damping material layer and the second viscoelastic damping material layer is selected from the group including elastomers, butyl rubber, styrenic block copolymers, polyurethanes, silicone rubbers, nitrile rubbers, isoprene, butadiene, viscoelastic polymer gels, pressure sensitive adhesives, non-pressure sensitive adhesives, and combinations thereof.

34. 34. The constraining layer system of claim 33, wherein the pressure sensitive adhesive comprises an acrylic adhesive, a silicone adhesive, a rubber adhesive, a vinyl ether adhesive, and combinations thereof.

35. 26. The constraining layer system of claim 25, wherein the first layer of viscoelastic damping material and the second layer of viscoelastic damping material have the same chemical composition.

36. 26. The constraining layer system of claim 25, wherein the first layer of viscoelastic damping material and the second layer of viscoelastic damping material have different chemical compositions.

37. 26. The constraining layer system of claim 25, wherein at least one of the first layer of viscoelastic damping material and the second layer of viscoelastic damping material is substantially continuous.

38. 26. The constrained layer system of claim 25, wherein the CLF is at least 0.05 at 200 Hz over a range of 15 degrees Celsius.

39. 26. The constrained layer system of claim 25, wherein the CLF is at least 0.10 at 200 Hz over a range of 15 degrees Celsius.

40. Linear density normalized attenuation efficiency index (ζ) of at least 2.0×10 at 200 Hz ３ 26. The constraining layer system of claim 25, wherein said constraining layer system is greater than

41. A linear density normalized attenuation efficiency index (ζ) of at least 4.5×10 at 200 Hz ３ 26. The constraining layer system of claim 25, wherein

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