Thermal shielding device, material, and method thereof

Abstract

The teachings herein concern thermal shielding devices for reducing and / or delaying heating in areas near a heat source. The thermal shielding device includes a polymer core layer interposed between a metal layer and a barrier layer. Preferably, the barrier layer provides a thermal barrier, an electrical barrier, or both.

Description

[Technical Field]

[0001] Claim of priority This application claims priority to U.S. Provisional Patent Application No. 63 / 451,306, filed on 10 March 2023, the contents of which are incorporated herein by reference in their entirety.

[0002] The teachings herein relate to composite materials, material systems, and thermal shielding devices for reducing the flow of thermal energy and / or electrical conductivity. Thermal shielding devices include, or are formed from, a composite material comprising two metal layers separated by a core layer. Thermal shielding devices include a barrier layer that provides an additional thermal and / or conductive barrier. The composite material may include the barrier layer (for example, the barrier layer may be attached to or mounted on the composite material), or the barrier layer may be provided as a separate, unattached material. Preferably, the composite material is a multilayer material comprising the barrier layer. [Background technology]

[0003] Typically, heat shields are made from metal sheets, and their sole purpose is to provide a direct barrier against the propagation of flames from one side of the shield to the other. However, in some applications, it is also necessary to reduce heat flow from one side of the shield to the other. Because heat shields are usually made from metals with high thermal conductivity, heat flows rapidly from one side to the other. This can be particularly problematic when there is minimal space on the "cool" side between the heat shield and the object that needs to be protected. One example is inside a vehicle powered by battery cells, where the space between the battery cells and the occupant compartment is limited.

[0004] Arc discharge between the battery cell and the metal layer of the shielding can cause rapid heating of the shielding, and even collapse of the shielding. Such heating or collapse may initially be localized, but in a short period of time, the affected area will rapidly expand, and the shielding will no longer be effective.

[0005] As the capacity and / or size of vehicle batteries increases, the weight of the heat shield generally increases. This weight can affect vehicle performance, particularly with respect to energy efficiency.

[0006] A thermal shielding device including a composite material that reduces thermal conductivity through the composite material, absorbs thermal energy through an endothermic reaction, or has a polymer core that expands in thickness (e.g., by gas generation) is described in U.S. Patent Application No. 17 / 628,346, filed Jan. 19, 2022, by Tullis et al. and published as US 2022 / 0258453 A1, the content of which is incorporated herein by reference in its entirety.

[0007] There continues to be a need for materials, material systems, thermal shielding devices, and methods for improving one or any combination of the following characteristics: reduction of heat flow through a material or device, reduction of the thermal conductivity of a material or device, reduction of the weight of a material or device, ability to expand in thickness more than the thermal expansion coefficient of a material or device, ability to absorb thermal energy through an endothermic reaction, ability to retard flame, ability to reduce sound transmission, ability to provide electrical insulation, or ability to reduce or eliminate arcing. SUMMARY OF THE INVENTION

[0008] One or more of the above needs are solved by the laminated materials, thermal shielding devices, methods, systems, and battery covers according to the teachings herein.

[0009] One aspect of the present invention is directed to a laminate and / or thermal shielding device comprising a first metal layer, a second metal layer, a core layer (preferably an expandable core layer) interposed between the first metal layer and the second metal layer, and a barrier layer providing a thermal barrier (e.g., a thermal insulator), an electrical barrier (e.g., an electrical insulator), or both.

[0010] Another aspect of the present invention relates to a material system comprising a laminate or other composite material including a first metal layer, a second metal layer, and a core layer (preferably an expandable core layer) interposed between the first and second metal layers, wherein the material system includes a barrier layer that provides a thermal barrier (e.g., a thermal insulator), an electrical barrier (e.g., an electrical insulator), or both. The barrier layer and the laminate may be provided as separate materials, and the laminate preferably includes the barrier layer. The laminate is preferably in the form of a coil, and more preferably the coil (e.g., each layer of the coil) is sufficiently ductile so that the laminate can be press-formed.

[0011] The above aspects of the present invention further include one or any combination of the following: The barrier layer is either directly adjacent to the first metal layer, or the insulating layer is attached to the first metal layer. The barrier layer is attached to the first metal layer using an adhesive (e.g., a pressure-sensitive adhesive). The core layer and the first metal layer are interposed between the second metal layer and the barrier layer (for example, the layers are arranged in the following order: barrier layer, first metal layer, core layer, second metal layer). The barrier layer is the outer layer of the device (for example, facing one or more battery cells). The barrier layer and core layer are interposed between the first metal layer and the second metal layer (for example, the layers are arranged in the following order: first metal layer, barrier layer, core layer, and second metal layer). The barrier layer comprises a composition containing aerogel. The barrier layer includes a high-resistivity coating. High resistivity coatings include polyvinyl chloride (PVC). High resistivity coatings contain plastisol. High resistivity coatings contain flame retardants and / or carbonizers. A high-resistivity coating is applied as a coating containing one or more solvents. The barrier layer contains a composite material including inorganic fibers. The inorganic fibers include glass fibers, and the composite material includes silicone rubber, or preferably both. The composite material includes one or more layers of silicone rubber (e.g., two or more layers, or three or more layers) and one or more layers of glass fiber (e.g., two or more layers, or three or more layers). The barrier layer contains one or more inorganic compounds. One or more inorganic compounds include mineral fillers. The mineral filler contains silicates, preferably aluminum silicate. The barrier layer includes a mica sheet. The barrier layer is a flame-retardant coating, preferably a flame-retardant coating containing a carbon powder additive. The flame-retardant coating, when tested at 700°C (preferably at 800°C, more preferably at 900°C, and most preferably at 982.2°C), exhibits a flame resistance of 6 hours or more on the aluminum surface. The barrier layer contains expandable graphite. Aerogels include carbon aerogel, silica aerogel, alumina aerogel, chromia aerogel, graphene aerogel, or tin oxide aerogel. The aerogel has a thermal conductivity of approximately 0.400 W / m·K or less, preferably approximately 0.070 W / m·K or less, more preferably approximately 0.040 W / m·K or less, even more preferably approximately 0.025 W / m·K or less, and most preferably approximately 0.021 W / m·K or less, measured at approximately 23°C. The barrier layer is sufficiently ductile so that the thermal shielding device can be formed by pressing the layer and / or so that the thermal shielding device can be wound onto a roll. The barrier layer is attached to the first metal layer using an adhesive, preferably a pressure-sensitive adhesive. The core layer is a polymer core layer comprising a first additive selected from the group consisting of flame-retardant compounds and gas-generating compounds, or a second additive selected from the group consisting of antioxidants, reinforcing fillers, and mineral fillers. The polymer core layer contains a first additive and a second additive. The core layer is a polymer core layer containing one or more gas-generating compounds that produce gas (preferably carbon dioxide or water) at a temperature of approximately 100°C to approximately 320°C. The first metal layer and the second metal layer are formed from the same material (preferably steel or aluminum). The first metal layer and the second metal layer are formed from different materials (for example, the first metal layer is either a steel layer or an aluminum layer, and the second metal layer is the other). The ratio of the thickness of the second metal layer to the thickness of the first metal layer is approximately 1.4 or greater. The thermal shielding device has a thermal conductivity of approximately 0.015 to approximately 4 W / m·K. When heated to a temperature of approximately 100°C or higher, the core layer increases the separation distance between the first metal layer and the second metal layer in one or more regions, and the thickness of the thermal shielding device increases by approximately 15 percent or more in one or more regions. The polymer core layer generates or releases a sufficient amount of gas upon heating (e.g., above approximately 100°C, 200°C, 250°C, or 350°C), causing separation of the metal layers and an increase in the thickness of the thermal shielding device in one or more regions. The core layer contains a compound having one or more water of hydration. The core layer, excluding voids and / or pores within the core layer, has a density of approximately 0.90 to 2.00 g / cm³ at a temperature of approximately 25°C. 3 It is made from a material having a density of The core layer contains a polymer, and the thermal shielding device preferably contains a catalyst that accelerates the decomposition of the polymer so as to increase the pressure between the metal layers. The heat shielding device has a thickness of approximately 0.70 mm to approximately 5.0 mm. The ratio of the core layer thickness to the thermal shielding device thickness is approximately 0.15 to 0.45, and the ratio of the barrier layer thickness to the thermal shielding device thickness is approximately 0.15 to 0.45. Alternatively, the heat shielding device is approximately 0.05 m 2 Above and / or approximately 20.0m 2 Having the following area: It can be characterized by one or any combination of these.

[0012] Another aspect of the present invention relates to a battery cover, preferably for a plug-in electric vehicle, which includes a laminate comprising a thermal shielding device and / or barrier layer as taught herein.

[0013] Another aspect of the present invention relates to the use of a battery cover as taught herein in an automobile. Preferably, the battery cover comprises a laminate having a polymer core layer having a thermal conductivity of about 0.05 to about 4 W / m·K. Preferably, the battery cover is positioned between the vehicle battery, which supplies power for an electric motor that drives the vehicle, and the occupant compartment.

[0014] Further aspects of the present invention relate to a system including a battery cover as taught herein, an electric motor for driving one or more wheels of a vehicle, and one or more battery cells for supplying power to the electric motor, wherein the battery cover is positioned over the one or more battery cells. Preferably, the battery cover is substantially horizontal. Optionally, the battery cover is mounted on a container holding one or more battery cells, and / or the battery cover is mounted on the vehicle body and positioned below the occupant compartment. Optionally, the system includes a gap above or below the battery cover to allow for an increase in the separation between the first metal layer and the second metal layer.

[0015] This aspect of the present invention may be further characterized by one or any combination of the following: the battery cover is positioned such that the barrier layer faces one or more battery cells, or the barrier layer has an electrical resistivity sufficiently high to prevent or reduce arc discharge or other electrical disturbances.

[0016] Another aspect of the present invention relates to a method for forming a thermal shielding device, comprising the steps of press-forming or punching a material system or laminate in accordance with the teachings herein.

[0017] Another aspect of the present invention relates to a method for applying a material system to a battery, comprising the steps of positioning a barrier layer on a housing containing one or more battery cells, positioning a laminate or other composite material on the barrier layer, and attaching the laminate to the housing. [Brief explanation of the drawing]

[0018] [Figure 1] This is an exemplary cross-sectional view of a laminate without a barrier layer. [Figure 2] This is an exemplary cross-sectional view of a thermal shielding device, or a thermal shielding device including a laminate having a first metal layer interposed between a barrier layer and a core layer. [Figure 3] This is an exemplary cross-sectional view of a thermal shielding device, or a thermal shielding device including a laminate having a barrier layer interposed between a first metal layer and a core layer. [Figure 4] This is an exemplary cross-sectional view of a thermal shielding device, or a thermal shielding device including a laminate having two or more barrier layers. [Figure 5] This is an exemplary cross-sectional view of a thermal shielding device, or a thermal shielding device including a laminate having an adhesive layer for attaching a barrier layer to a laminate (for example, to a first metal layer). [Figure 6] This is an exemplary cross-sectional view of a part of a thermal shielding device, or a thermal shielding device including a laminate and a separate barrier layer (i.e., the barrier layer is not attached to the laminate). [Figure 7] This is a top view of a thermal shielding device showing one or more shielding regions and one or more extension regions. The extension regions may be formed from the same material as the shielding regions, or from different materials. [Figure 8] This is a top view of a thermal shielding device, showing one or more mounting locations located in or near the edge region of the device. [Figure 9]This is a side cross-sectional view of a thermal shielding device, showing a layer of composite material within the shielding region and one or more bent portions, protrusions, or extensions angled relative to the shielding region. The bent portions, protrusions, or extensions may be made of composite material or different materials. [Figure 10] This is an exemplary side cross-sectional view showing a thermal shielding device expanding during an extreme thermal event. As shown in Figure 5, the edges of the composite material may be sealed. For example, two metal layers may be welded, joined, or otherwise sealed at their common edges. [Figure 11] This is an exemplary cross-sectional view of the marginal region. [Figure 12A] This is a cross-sectional view of an exemplary edge region of a thermal shielding device, showing the installation of the device. [Figure 12B] Figure 12A shows the characteristics of the core layer after expansion (for example, during or after an extreme thermal event). [Figure 13] This is a cross-sectional view of an exemplary edge region having a fracture point. [Figure 14] This is a cross-sectional view showing localized expansion of a thermal shielding device due to an extreme thermal event. [Figure 15] This is a cross-sectional view showing a composite material for a thermal shielding device having components for storing potential energy, such as one or more compressed springs. [Figure 16] This is a cross-sectional view showing a composite material for a thermal shielding device having a metal layer that can expand in one or more regions without yielding of the metal layer. [Figure 17] Figure 16 shows the melting or softening of the polymer within the core layer region when the thermal shielding device is exposed to heat. [Figure 18] Figure 17 shows the local expansion of the thermal shielding device. It is preferable that the separation distance between the two metal layers increases without yielding of the metal layers. [Figure 19A] This is a cross-sectional view showing the formation of a composite material for a thermal shielding device using one or both of the curved metal layers. [Figure 19B] This shows the composite material after formation, and the composite material includes the potential energy from the compressed metal layer(s). [Figure 20A]This describes an edge covering component having one or more features for expanding the element without yielding of the covering component material. [Figure 20B] Figure 20A shows the edge covering component after the core layer has expanded. Preferably, the covering component seals the edge before and / or after the core layer has expanded. [Modes for carrying out the invention]

[0019] The thermal shielding device is preferably configured such that the heat flow through the thermal shielding device is reduced or minimized, and / or arc discharge is reduced or eliminated. The thermal shielding device taught herein comprises a composite material having a first metal layer and a second metal layer separated by a polymer core layer, and further comprising a barrier layer. The material of the composite material may be selected such that the thermal conductivity of the composite material in the thickness direction (i.e., through the two metal layers and the polymer core layer) is reduced compared to the thermal conductivity of the first metal layer, the second metal layer, or both. The barrier layer may provide a thermal barrier (e.g., a thermal insulator), an electrical barrier (e.g., an electrical insulator), or both. The core layer preferably contains a flame retardant compound or a gas-forming compound. The combination of the core layer and the barrier layer improves shielding performance, particularly against heat and / or arc discharge from batteries. Furthermore, by using materials for the core layer and barrier layer that are relatively less dense (e.g., compared to the metal layers), performance can be improved while maintaining a light weight. The combination of lightweight properties and improved thermal and / or electrical insulation can be particularly important in shielding vehicle batteries.

[0020] The thermal shielding device is preferably designed such that the spacing between the metal layers can increase when the device is exposed to high temperatures, for example, during extreme thermal events such as those discussed herein. The spacing between the metal layers may further reduce the heat flow through the thermal shielding device.

[0021] The thermal shielding device may include one or more features that induce an endothermic reaction during heating, thereby reducing heat transfer through the thermal shielding device.

[0022] The thermal shielding device may include one or more features that help delay the amount of heat transferred through the device by preventing or delaying the burning of the polymer core layer.

[0023] While various approaches to reduce heat transfer are described herein, it will be understood that multiple approaches may be combined to achieve further improvements.

[0024] Furthermore, the materials used in the thermal shielding device can be selected to achieve a reduction in density, especially when the device is used in an automobile, particularly when the automobile is driven by an electric motor, such as a plug-in electric vehicle.

[0025] Extreme thermal events An extreme thermal event refers to an event that causes the temperature directly adjacent to the thermal shield, and / or the temperature on one surface of the thermal shield, to rise to a critical temperature above the normal operating temperature. The critical temperature may be approximately 80°C or higher, approximately 120°C or higher, approximately 160°C or higher, approximately 190°C or higher, or approximately 210°C or higher. The critical temperature may be approximately 600°C or lower, approximately 500°C or lower, approximately 400°C or lower, or approximately 300°C or lower.

[0026] Extreme thermal events can result from any event or situation that causes the temperature to reach or exceed a critical temperature. Examples of such events include fire, battery or battery cell failure, mechanical failure resulting in the generation of frictional energy, and cooling system failure. Extreme thermal events can be fatal events resulting in the failure of one or more components.

[0027] During extreme thermal events, it may be necessary to reduce heat flow in one or more directions. Reducing heat flow may be required to prevent further damage and / or to provide additional time to respond to the event.

[0028] Unless otherwise specified, the dimensions and characteristics of a thermal shielding device refer to the dimensions under ambient conditions prior to an extreme thermal event that could alter one or more dimensions of the device (i.e., approximately 25°C).

[0029] Figure 1 is a cross-sectional view of an exemplary laminate 10, which includes a first metal layer 12, a second metal layer 14, and a core layer 16 interposed between the first and second metal layers.

[0030] Figures 2, 3, 4, and 5 are cross-sectional views of an exemplary thermal shielding device 30 (or a portion of such a device) including a laminate 10' with a barrier layer 18. The barrier layer 18 may be adjacent to, directly in contact with, or attached to the first metal layer, as shown in Figures 2, 3, 4, and 5. The barrier layer 18 may be interposed between the first metal layer and the second metal layer, and / or between the first metal layer and the core layer, as shown in Figures 3 and 4. The first metal layer 12 may be interposed between the barrier layer and the core layer, as shown in Figures 2, 4, and 5. The laminate may include one or more barrier layers, or two or more barrier layers. The laminate may include a first metal layer interposed between two barrier layers, as shown in Figure 4. The barrier layer 18 may be attached to the metal layer using an adhesive 20, as shown in Figure 5. The barrier layer 18 may be provided in the laminate 10 as a separate component, as shown in Figure 6. For example, the barrier layer may be placed beneath the laminate 10 during assembly or installation of the heat shielding device 30. However, it is preferable that the barrier layer 18 is attached to the first metal layer so that the barrier layer can be processed together with the other layers of the heat shielding device (including, for example, pressing, punching, winding, storage, shipping, installation, molding, or any combination thereof).

[0031] The core layer is preferably a polymer core layer containing one or more polymers. The metal layers may have the same thickness or different thicknesses. The metal layers may be formed from the same metal or different metals. Preferably, the first and second metal layers are formed from aluminum or steel. More preferably, the first metal layer is formed from aluminum. Preferably, the first and second metal layers are formed from metals having substantially the same coefficient of thermal expansion (for example, the ratio of the coefficients of thermal expansion at about 500°C may be 0.666 to 1.500, about 0.80 to about 1.25, about 0.90 to about 1.1, or about 0.95 to about 1.05, or about 0.98 to about 1.02). Preferably, both the first and second metal layers are formed from the same metal, and more preferably, both the first and second metal layers are formed from aluminum. The thermal shielding device may include one or more adhesive layers. An adhesive layer can be used to bond the other two layers together, or to join them in other ways. It will be understood that the core layer may contain an adhesive for adhesion to the metal layer and / or the barrier layer. The metal layer may have coatings on one or more surfaces to protect the surface and / or to improve the adhesion of the metal layer to the core layer. The metal layer may have coatings on one or more surfaces (preferably the outer surface facing the heat source or battery cell) which reduces heat flow and / or heat generation. For example, the coatings may include a flame retardant (preferably a polymer containing a flame retardant), a nanocoating (preferably thermally conductive but electrically insulating), or both. A particularly preferred coating is one containing a flame retardant. The core layer is preferably attached to the first metal layer, the second metal layer, or both. The attachment preferably involves direct or indirect adhesion or bonding between the core layer and the metal layer(s). The core layer may contain polymers or additives that improve adhesion to one or both metal layers. One or both metal layers may be covered with an adhesive layer and / or a primer layer to provide adhesion to the core layer.

[0032] A thermal shielding device as taught herein includes a first metal layer, a second metal layer, a core layer interposed between the first and second metal layers, and one or more barrier layers. The barrier layers may provide a thermal barrier (e.g., a thermal insulator), an electrical barrier (e.g., an electrical insulator), or both. The thermal shielding device may provide a direct barrier to reduce or eliminate the propagation of heat or flame from one side of the shielding device to the other side (e.g., the opposite side or the opposite surface). For example, components that generate heat or flame may be located on the first side of the thermal shielding device, and / or components or compartments to be protected from heat or flame may be located on the second side of the thermal shielding device. Typically, the position of the first metal layer in the thermal shielding device is oriented toward the first side of the thermal shielding device (i.e., toward the components that generate heat or flame), and the position of the second metal layer is oriented toward the second side of the thermal shielding device. Preferably, a barrier layer is interposed between the first metal layer and the second metal layer, or the first metal layer is interposed between the barrier layer and the core layer. If a barrier layer is interposed between the first metal layer and the second metal layer, it may be interposed between the first metal layer and the core layer, or between the second metal layer and the core layer.

[0033] The laminate may be in the form of a coil structure. For example, a coil of the laminate may be manufactured, stored, or transported. The laminate may be unwound from the coil and / or cut into blanks for forming a thermal shielding device. Alternatively, the laminate may be in the form of a sheet. For example, a sheet of the laminate may be manufactured, stored, or transported. The sheet may be cut into blanks for forming a thermal shielding device.

[0034] The layers of the thermal shielding device can be arranged in the order of a barrier layer, a first metal layer, a core layer, and a second metal layer. Preferably, the thermal shielding device includes or is formed from a laminate comprising two or more, three or more, or all of the layers selected from the group consisting of a first metal layer, a second metal layer, a core layer, and a barrier layer. The laminate may optionally include one or more adhesive layers for bonding the other two layers to each other. For example, an adhesive layer may be used to bond the metal layer to the core layer, and / or an adhesive layer may be used to bond the barrier layer to the metal layer, and / or an adhesive layer may be used to bond the barrier layer to the core layer.

[0035] The barrier layer can be attached to the laminate containing the first metal layer by an adhesive. The barrier layer can also be attached directly to the first metal layer by an adhesive. For example, a pressure-sensitive adhesive can be used to attach the barrier layer to the laminate (e.g., to other layers of the laminate) and / or to the first metal layer.

[0036] The barrier layer may provide a thermal barrier (e.g., a thermal insulator), an electrical barrier (e.g., an electrical insulator), or both. Examples of barrier layers include, but are not limited to, compositions containing aerogels, composite materials containing inorganic fibers, materials containing or comprising one or more inorganic compounds, materials containing or comprising graphite, flame-retardant coatings, high-resistivity coatings, or any combination thereof. The barrier layer may be a single-layer structure, a composite, or a material having multiple layers. If the barrier layer comprises multiple layers, two of the layers may be formed from the same material or different materials.

[0037] The barrier layer may include a flame-retardant coating, may consist of an inherently flame-retardant coating, or may consist entirely of a flame-retardant coating. The flame-retardant coating can protect the metal surface from the effects of flame. For example, a flame-retardant coating may be applied to an aluminum surface. Without a flame-retardant coating, a metal (e.g., aluminum) may break if exposed to flame for an extended period (e.g., about 6 hours) at temperatures of about 700°C, about 800°C, about 900°C, or about 982.2°C. The breakage typically takes the form of a hole in a 1.5 mm thick metal sheet. The flame-retardant coating may allow the heat shield to be exposed to flames for 6 hours at temperatures of about 700°C, about 800°C, about 900°C, or about 982.2°C without damage (e.g., without burning), where the total thickness of the metal layer in the heat shield is about 1.4 mm or less (preferably about 1.3 mm or less, more preferably about 1.2 mm or less, and even more preferably about 1.1 mm or less), and / or the total weight of the heat shield is less than the weight of a 1.5 mm thick metal (e.g., aluminum or steel) and has the same shape (e.g., the same width and thickness as the heat shield). The flame-retardant coating may include low-density fibers, cementitious compounds, expansive coatings, gypsum, carbon powder additives, or cement. The flame-retardant coating may include one or more polymers, such as one or more thermosetting resins.

[0038] The barrier layer may include or consist of a layer of graphite. A preferred graphite layer is expandable graphite. The graphite may expand after the laminate containing the first metal layer and the graphite layer is formed (for example, after the laminate containing the first and second metal layers, the core layer, and the graphite layer is formed). The graphite may expand before the graphite layer is attached to the first metal layer or before the graphite layer is assembled with the laminate containing the first metal layer. Preferably, the graphite is expanded by treating it with an oxidizing agent. The graphite may have an expansion ratio of about 30 or more, about 50 or more, about 70 or more, about 90 or more, about 110 or more, about 130 or more, or about 140 or more. The graphite may have an expansion ratio of about 250 or less, about 200 or less, or about 175 or less.

[0039] The barrier layer may include, or consist of, a layer formed of a material containing inorganic fibers. The inorganic fibers may be woven or unwoven. The inorganic fibers may include fibers preferentially oriented in one or more directions. The inorganic fibers may include fibers randomly oriented. The inorganic fibers may include short (e.g., weight-average length less than about 5 cm), medium length (e.g., weight-average length about 5 cm to about 20 cm), or long (e.g., weight-average length greater than about 20 cm) fibers. A preferred inorganic fiber is glass fiber. The glass fiber may be provided in one or more layers. For example, the barrier layer may include two or more layers of glass fiber. Preferably, the barrier layer containing inorganic fibers is a composite including one or more layers of polymer material. Preferably, adjacent layers of glass fiber are separated by the polymer material. The polymer material may be a thermoplastic material, a thermosetting material, or a rubber material. The polymer material preferably includes a synthetic polymer. The polymer material preferably includes or consists of an inorganic polymer material, such as a silicon-based polymer. A preferred silicon-based polymer is silicon rubber. For example, the barrier layer may include multiple layers of glass fibers separated by layers of silicon-based polymer (e.g., silicon rubber). The composite material containing inorganic fibers may include one or more layers of silicon rubber, two or more, or three or more layers, and one or more layers of glass fibers, two or more, or three or more layers. The composite material for the barrier layer preferably has a thickness of about 0.2 mm or more, about 0.4 mm or more, about 0.6 mm or more, or about 0.7 mm or more. To reduce cost and / or weight, the composite material for the barrier layer preferably has a thickness of about 3.0 mm or less, about 2.5 mm or less, about 2.1 mm or less, about 1.8 mm or less, or about 1.7 mm or less. For example, the thickness of the composite barrier layer (e.g., glass / silicon polymer composite) may be approximately 0.70 to 1.10 mm, 0.90 to 1.30 mm, 1.10 to 1.50 mm, 1.30 to 1.70 mm, 1.50 to 1.90 mm, 1.70 to 2.10 mm, 1.90 to 2.30 mm, or 2.1 to 3.0 mm. The barrier layer (e.g., composite material) is preferably approximately 1.40 g / cm³ as measured according to ISO 2781. 3Greater than or about 1.50 g / cm 3 Greater than or about 1.55 g / cm 3 It has a density greater than or equal to. The density of the barrier layer (e.g., composite material) is preferably measured in accordance with ISO 2781 and is about 1.80 g / cm 3 Less than or about 1.70 g / cm 3 Less than or about 1.65 g / cm 3 Less than or equal to. The barrier layer (e.g., composite material) preferably has one or more of the following properties, namely, A V1 flammability rating measured in accordance with UL94-V1, No burnout after 30 minutes at 1000 °C (oxyacetylene flame and / or oxygen propane flame), A thermal conductivity less than 0.3 W / m·K measured in accordance with ASTM D5470, A dielectric strength of about 10 kV / mm or more measured in accordance with ASTM D149, or A hardness (durometer) of about 90 Shore A or less (preferably about 82 Shore A or less) measured in accordance with ISO 48-4 It has. Examples of composite materials that can be used for the barrier layer include Thermal Barrier MK-315 (having three layers of woven glass and two layers of elastomer, with a thickness of about 1.5 mm) and Thermal Barrier MK-108 (having one layer of woven glass and one layer of elastomer, with a thickness of about 0.80 mm), which are commercially available from NB Materials Co., Ltd.

[0040] The barrier layer of the heat shielding device may include a high-resistivity coating layer. The high-resistivity coating layer preferably includes a thermoplastic composition containing thermoplastic polyvinyl chloride (PVC). The thermoplastic composition may be applied as a coating containing one or more solvents. The one or more solvents preferably include one or more aromatic solvents, one or more alcohols, one or more ketones, one or more alkanes, or any combination thereof. The one or more solvents preferably include one, two, three, four, or all of toluene, phenol, n-alcohols having 3 to 6 carbon atoms (preferably having 3 or 4 carbon atoms), ethyl alcohol, and ketones (e.g., branched ketones). The thermoplastic composition preferably includes a plasticizer. The concentration of the plasticizer in the thermoplastic composition is preferably high enough so that the barrier layer can be processed by pressing, bending, drawing, or other molding processes without rupture or delamination of the barrier layer. The thermoplastic composition containing PVC preferably includes a flame retardant, a carbonizing agent, or both. Based on the total weight of the barrier layer, the total concentration of PVC, flame retardants and / or carbides, and any plasticizers is approximately 98% by weight or more, approximately 99% by weight or more, approximately 99.5% by weight or more, approximately 99.8% by weight or more, or approximately 100% by weight.

[0041] A thermal shielding device (e.g., a barrier layer) as taught herein may include a layer of a composition containing an aerogel. The aerogel-containing composition is preferably interposed between a first metal layer and a core layer, or the aerogel is interposed between a second metal layer and a core layer, or the first metal layer is interposed between the core layer and the aerogel. More preferably, the aerogel-containing composition is interposed between the core layer and a first metal layer, or the first metal layer is interposed between the core layer and the aerogel. Most preferably, the aerogel-containing composition is in direct contact with the first metal layer or attached to the first metal layer. Typically, the aerogel is an ultralight solid material having a porosity of about 75 volume percent or more, about 86 volume percent or more, about 94 volume percent or more, or about 97 volume percent or more. The porosity of the aerogel may be about 99 volume percent or less, or about 98 volume percent or less. The aerogel may be formed from a gel having a liquid component, or it may be formed by replacing the liquid component with a gas. Preferably, at least 80% by weight, at least about 90% by weight, at least about 95% by weight, at least about 98% by weight, at least about 99.5% by weight, or about 100% by weight of the liquid component is replaced with gas. The aerogel-containing composition is preferably an expandable material that expands when heated. For example, a composition containing an aerogel material may be included in a thermal shielding device, where the composition may be activated by thermal events within the shielded component, thereby activating the aerogel-containing composition and causing expansion. The aerogel may include, but is not limited to, carbon aerogel, silica aerogel, alumina aerogel, chromia aerogel, graphene aerogel, tin oxide aerogel, or any combination thereof.Aerogels may contain, or essentially consist of, carbon atoms (optionally, in some or all form of graphene) (e.g., at least about 70 wt percent, at least about 80 wt percent, at least about 90 wt percent, at least about 95 wt percent, at least about 99 wt percent, or about 100 wt percent), silicon atoms, aluminum atoms, tin atoms, chromium atoms, oxygen atoms, or any combination thereof. Aerogels or compositions containing aerogels preferably have a thermal conductivity (measured at 23°C) lower than the thermal conductivity of the core layer. In the case of aerogels, the thermal conductivity (measured at 23°C) may be about 0.400 W / m·K or less, preferably about 0.070 W / m·K, more preferably about 0.040 W / m·K or less, more preferably about 0.025 W / m·K or less, and most preferably about 0.021 W / m·K. Preferably, the barrier layer containing the aerogel material expands at temperatures of about 200°C or higher, about 250°C or higher, about 300°C or higher, or about 350°C or higher. The expansion of the aerogel barrier layer is preferably about 200 volume percent or more, more preferably about 300 volume percent or more, even more preferably about 400 volume percent or more, and most preferably about 500 volume percent or more. The volume expansion is preferably about 1500% or less, about 1000% or less, or about 750% or less, but higher levels of expansion may be used. The aerogel barrier layer may contain a binder, an oligomeric material (e.g., having a molecular weight of less than 8,000 or about 4,000 or less), or a polymer material (e.g., having a molecular weight of 8,000 or more, about 20,000 or more, or about 40,000 or more). The aerogel barrier layer may be applied as a coating. Preferred coating materials have a viscosity of approximately 400 to 12,000 cps (measured at 25°C). Coating materials containing aerogel are preferably tactilely dry and / or cure in approximately 48 hours or less, approximately 24 hours or less, approximately 12 hours or less, approximately 6 hours or less, or approximately 3 hours or less. Drying time can be measured with a coating applied to a thickness of approximately 0.4 mm using a brush application at 25°C and 50% relative humidity.Coating materials containing aerogel preferably have a solid content of about 20 volume percent or more, about 30 volume percent or more, about 40 volume percent or more, or about 50 volume percent or more. Coating materials containing aerogel preferably have a solid content of about 80 volume percent or less, about 70 volume percent or less, or about 65 volume percent or less. Barrier layers containing aerogel preferably have a thickness of about 0.10 mm or more, about 0.20 mm or more, about 0.30 mm or more, about 0.4 mm or more, or about 0.50 mm or more, and / or about 3.0 mm or less, about 2.0 mm or less, about 1.50 mm or less, about 1.20 mm or less, about 1.10 mm or less, or about 1.00 mm or less. Typical compositions containing aerogel are brittle when dry and / or cured, and cannot be press-formed when applied as a coating. Preferably, the barrier layer containing the aerogel (for example, after drying or curing if applied as a coating layer) is sufficiently ductile so that the heat shielding device can be processed by pressing, bending, drawing or other forming processes without rupture or delamination of the barrier layer.

[0042] The barrier layer and / or composite material for the thermal shielding device may contain one or more inorganic compounds. The inorganic compounds preferably include mineral fillers. The inorganic compounds may include silicates or mica. The silicates may include aluminum silicate or consist essentially of aluminum silicate. The amount of inorganic compounds in the barrier layer may be about 53% by weight or more, about 66% by weight or more, about 82% by weight or more, about 91% by weight or more, about 97% by weight or more, or about 99% by weight or more. The amount of inorganic compounds in the barrier layer may be about 100% by weight or less. The barrier layer may include a mica sheet or a silicate sheet. The inorganic compounds may result in an increase in electrical resistance (e.g., compared to a first metal layer and / or a second metal layer), a decrease in thermal conductivity (e.g., compared to a first metal layer and / or a second metal layer), or preferably both. The barrier layer, comprising one or more inorganic compounds, is preferably sufficiently flexible so that the laminate containing the barrier layer can be wound onto a roll without cracking or breaking at a given position. Preferably, the barrier layer can be wound along a roll of about 100 mm, about 200 mm, about 300 mm, about 400 mm, or about 500 mm without cracking or breaking.

[0043] The barrier layer for the thermal shielding device and / or composite material is preferably sufficiently ductile so that the thermal shielding device can be formed by press-forming a laminate comprising a first metal layer, a second metal layer, a core layer, and a barrier layer. The barrier layer has an elongation at break of preferably about 10% or more, more preferably about 20% or more, even more preferably about 30% or more, and most preferably about 40% or more, as measured according to ISO 37.

[0044] The barrier layer and / or composite material for the thermal shielding device is preferably sufficiently ductile so that the barrier layer and / or laminate, which includes a metal layer(s), a core layer, and a barrier layer, can be wound onto a roll (for example, on a roll having a diameter of about 100 mm or more, about 150 mm or more, about 200 mm or more, about 250 mm or more, about 300 mm or more, or about 400 mm or more). The barrier layer preferably has a durometer of about 95 Shore A or less, about 91 Shore A or less, about 88 Shore A or less, about 85 Shore A or less, about 82 Shore A or less, or about 79 Shore A or less, as measured according to ISO 48-4. The barrier layer preferably has a durometer of about 22 Shore A or more, about 35 Shore A or more, about 45 Shore A or more, or about 60 Shore A or more.

[0045] The barrier layer should have sufficient thickness to provide the required electrical and / or thermal barrier properties. Preferably, the barrier layer thickness is about 0.30 mm or more. If the barrier layer is too thick, the weight of the thermal shielding device may be too high and / or the cost of the barrier layer may be too high. Preferably, the barrier layer has a thickness of about 4.0 mm or less, more preferably about 3.0 mm or less, and most preferably about 2.5 mm or less. It will be understood that as the cost of the barrier material increases and / or the density of the barrier layer material increases, the upper limit of the barrier layer thickness decreases. For such materials, the barrier layer thickness is preferably about 2.2 mm or less, about 1.9 mm or less, about 1.60 mm or less, about 1.40 mm or less, about 1.20 mm or less, about 1.00 mm or less, or 0.90 mm or less.

[0046] The initial thickness of the thermal shielding device or laminate (for example, at about 25°C, before an abnormal thermal event) is preferably about 0.70 mm or more, more preferably about 0.90 mm or more, and most preferably about 1.20 mm or more. The initial thickness of the thermal shielding device or laminate is preferably about 6 mm or less, more preferably about 5.00 mm or less, even more preferably about 3.50 mm or less, and most preferably about 3.00 mm or less. The ratio of the initial thickness of the polymer core layer to the initial thickness of the thermal shielding device or laminate is preferably about 0.150 or more, about 0.20 or more, about 0.25 or more, or about 0.30 or more and / or about 0.85 or less, about 0.80 or less, 0.75 or less, or about 0.70 or less, or about 0.60 or less, or about 0.50 or less, or about 0.45 or less. The polymer core layer preferably has an initial thickness of about 0.3 mm or more, 0.4 mm or more, about 0.6 mm or more, or about 0.8 mm or more. The polymer core layer preferably has an initial thickness of about 3.00 mm or less, about 1.90 mm or less, about 1.3 mm or less, or about 1.0 mm or less. The ratio of the initial thickness of the barrier layer to the initial thickness of the heat shielding device or laminate is preferably about 0.150 or more, about 0.20 or more, about 0.25 or more, or about 0.30 or more, and / or about 0.60 or less, about 0.50 or less, or about 0.45 or less. The barrier layer preferably has an initial thickness of about 0.2 mm or more, 0.4 mm or more, about 0.6 mm or more, or about 0.8 mm or more. The barrier layer preferably has an initial thickness of about 4.00 mm or less, or about 3.2 mm or less, or about 2.5 mm or less, or about 2.0 mm or less, or 1.50 mm or less, or 1.00 mm or less.

[0047] The thermal shielding device preferably has a sufficient area (for example, perpendicular to the thickness direction or in the direction of the normal), thereby reducing the heat exposure to one or more devices, or one or more components, or multiple compartments. The thermal shielding device preferably has an area of ​​about 0.05 m 2 The above is approximately 0.15m 2 More than 0.45m 2 Above, or approximately 1.85m 2It has the above area. In some applications, the area of ​​the heat shielding device is approximately 20.0 m². 2 Below, approximately 18.0m 2 Below, approximately 16.0m 2 Below, approximately 13.0m 2 Below, or approximately 10m 2 The following applies: In some applications, the area of ​​the heat shielding device is 20.0 m². 2 It will be understood that larger is better. The thermal shielding device may be replaced by two or more smaller sections or components. Each section or component may include composite materials as taught herein.

[0048] Thermal conductivity The thermal conductivity of the thermal shielding device is measured in the thickness direction through the metal layer and the polymer core layer. The thermal conductivity of the polymer core layer and / or the thermal shielding device is preferably about 4.0 W / m·K or less, about 2.00 W / m·K or less, about 1.0 W / m·K or less, or about 0.80 W / m·K or less. Preferably, the thermal conductivity of the polymer core layer and / or the thermal shielding device is about 0.05 W / m·K or more. The thermal conductivity is preferably measured at a temperature of about 25°C. Unless otherwise specified, the thermal conductivity of the thermal shielding device and / or the polymer core layer may be measured according to ASTM D 5930 17.

[0049] Weight / density reduction The core layer and / or metal layer may be selected to reduce the weight of the thermal shielding device.

[0050] The density of the core layer is approximately 2.30 g / cm³. 3 Below, approximately 2.00g / cm 3 Below, approximately 1.80g / cm 3 Below, approximately 1.60g / cm 3 Below, approximately 1.40g / cm 3 The following, or approximately 1.30 g / cm³ 3 The following is possible: The density of the core layer is approximately 0.950 g / cm³. 3 Above, or approximately 1.10 g / cm³ 3 That's fine too.

[0051] One or both of the metal layers may be formed from steel, or selected to have a lower density than steel. Each metal layer independently has a density of approximately 8.0 g / cm³. 3 Below, about 7.7g / cm 3 Below, about 6.8g / cm 3 Below, approximately 5.6g / cm 3 Below, about 5.0g / cm 3 Below, approximately 4.6g / cm 3 Below, approximately 4.1g / cm 3 The following, or approximately 3.3 g / cm³ 3 The following densities can be selected: The density of the metal layer is typically about 2.5 g / cm³. 3 That concludes the explanation. Particularly preferred metals having a density lower than that of steel include aluminum, aluminum alloys containing at least 60 atomic percent of aluminum atoms (based on the total number of metal atoms), titanium, and titanium alloys.

[0052] It will be understood that the reduction in weight and / or density may be due in part or even entirely to the polymer core layer. For example, the thickness and / or density of the core layer may be sufficient to result in some or all of the weight improvement of the thermal shielding device.

[0053] The ratio of the density of the composite material of the thermal shielding device to the average density of the metal layer is preferably about 95% or less, about 90% or less, about 85% or less, about 80% or less, or about 75% or less. The ratio of the density of the composite material of the thermal shielding device to the average density of the metal layer may be about 20% or more, about 30% or more, about 40% or more, or about 50% or more. The average density of the metal layer is D avg The formula can be calculated as =(t1D1+t2D2) / (t1+t2), where t1 and t2 are the thicknesses of the first and second metal layers, and D1 and D2 are the densities of the first and second metal layers.

[0054] Polymer core layer The polymer core layer comprises one or more polymers. Preferably, the polymer core layer comprises one or more first additives selected from the group consisting of flame retardant compounds and gas-generating compounds, and / or one or more second additives selected from the group consisting of antioxidants, reinforcing fillers, and mineral fillers. Preferably, the polymer core layer comprises both the first and second additives.

[0055] The amount of polymer in the polymer core layer must be sufficient so that the polymer forms a continuous phase and / or so that the core layer material can be extruded as a filler polymer. Preferably, the amount of polymer in the polymer core layer is about 10% by weight or more, about 12% by weight or more, about 14% by weight or more, about 16% by weight or more, about 18% by weight or more, or about 20% by weight or more. The core layer may consist entirely of one or more polymers, but the core layer preferably contains one or more non-polymeric components that help reduce heat flow, especially during extreme thermal events. Thus, the amount of polymer in the core layer is preferably about 95% by weight or less, about 90% by weight or less, about 80% by weight or less, about 70% by weight or less, about 60% by weight or less, about 50% by weight or less, or about 40% by weight or less.

[0056] polymer If a polymer is below its melting temperature or glass transition temperature, it may be difficult for it to expand when gas is released or generated within the polymer core layer. Thus, polymers may be selected to melt when gas is released or generated within the polymer core layer (e.g., during extreme thermal events).

[0057] Melting temperature As used herein, the term “melting temperature” refers to the peak melting temperature for semi-crystalline polymers and the glass transition temperature for amorphous thermoplastic polymers. Generally, the melting temperature provides an indicator of the temperature at which polymer molecules begin to flow. With respect to foaming or gas generation, the melting of this crystal, or the increase in free volume associated with heating above the glass transition temperature, results in polymers that can more easily expand and adapt to gas pockets.

[0058] If the polymer's melting temperature is too low, the thermal shielding device may be damaged by the melting or softening of the polymer during normal use. A preferred melting temperature for the polymer is preferably about 90°C or higher, more preferably about 100°C or higher, even more preferably about 110°C or higher, and most preferably about 120°C or higher. The polymer's melting temperature should be sufficiently low so that the polymer remains above its melting temperature when gas is being generated or released within the polymer core layer (e.g., as a result of an extreme thermal event). The polymer temperature is preferably about 300°C or lower, more preferably about 240°C or lower, even more preferably about 200°C or lower, even more preferably about 170°C or lower, and most preferably about 145°C or lower. The glass transition temperature and peak melting temperature can be measured using differential scanning calorimetry at a heating rate of 10°C / min.

[0059] The polymer can melt or soften at temperatures near or below (preferably lower than) the activation temperature of the blowing agent. When the blowing agent is activated by thermal energy (e.g., during an extreme thermal event), the polymer foams. The polymer foam may be characterized by open bubbles, closed bubbles, or both. Pressure from the activated blowing agent and / or foam may cause the metal layer to separate.

[0060] The polymer core layer can generally be a high-density material before any extreme thermal event. For example, the amount of any voids and / or pores within the polymer core layer (and / or between metal layers) may be about 15 volume percent or less, about 10.0 volume percent or less, about 5.0 volume percent or less, about 3.0 volume percent or less, or about 1.5 volume percent or less, based on the total volume of the polymer core layer (and / or space between metal layers). High-density materials may have voids and / or pores of about 0 volume percent or more.

[0061] The polymer core layer may contain voids and / or pores dispersed throughout the layer before any extreme thermal event. Preferably, the voids and / or pores are in the form of polymer cells. Thus, the polymer core layer may be foamed and / or contain foamed polymer. The amount of voids and / or pores may be sufficient to reduce the thermal conductivity of the thermal shielding device. Preferably, the amount of voids and / or pores in the polymer core layer is about 3 volume percent or more, more preferably about 10 volume percent or more, even more preferably about 20 volume percent or more, and most preferably about 40 volume percent or more. The amount of voids and / or pores in the polymer core layer may be about 80 volume percent or less, about 70 volume percent or less, about 60 volume percent or less, or about 50 volume percent or less.

[0062] Any type of polymer may be used in the polymer core layer. The polymer may be a polyolefin, a polyolefin-free polyolefin, or a copolymer containing both olefin and non-olefin monomers. The polymer may be a homopolymer or a copolymer. Examples of copolymers include random copolymers, block copolymers, graft copolymers, and alternating copolymers. Preferred polyolefin-containing polymers contain or consist essentially of ethylene, propylene, butene, hexene, octene, or any combination thereof. Non-polyolefin polymers include polyamides, polyimides, polyacrylates, polyesters, polyethers, polycarbonates, polyacrylonitriles, copolymers thereof, derivatives thereof, and combinations thereof. The polymer may contain or consist of polystyrene. The polymer may contain a homopolymer or copolymer of polyethylene. Preferred polyethylene copolymers have an ethylene concentration of about 60% by weight or more, about 70% by weight or more, about 80% by weight or more, about 87% by weight or more, or about 93% by weight or more. The polymer may include polypropylene homopolymers or copolymers. Preferred polypropylene copolymers have a propylene concentration of about 60% by weight or more, about 70% by weight or more, about 80% by weight or more, about 87% by weight or more, or about 93% by weight or more. Some or all of this polymer may be grafted with functional groups to improve adhesion to the metal layer. Preferably, some or all of the polymer does not have such grafts. For example, the amount of polymer without grafts may be about 70% by weight or more, about 80% by weight or more, about 90% by weight or more, about 96% by weight or more, or about 99% by weight or more. The polymer may be a semicrystalline polymer at 25°C. Preferred semicrystalline polymers have a crystallinity of about 6% or more, more preferably about 10% or more, even more preferably about 20% or more, even more preferably about 30% or more, and most preferably about 38% or more. The crystallinity may be about 80% or less, about 70% or less, or about 60% or less.Crystallinity can be measured using differential scanning calorimetry at a heating rate of 10°C / min, where the heat of fusion is measured and compared to the theoretical heat of fusion known for the polymer. Crystallinity = 100% × H. f / H theory .

[0063] The polymer core layer contains multiple polymers. The multiple polymers may be in a single layer or in separate layers. The multiple layers of polymers may have different melting temperatures and may be used to determine where melting and / or expansion first occurs. For example, it may be desirable for initial melting to occur near the center of the polymer core layer. Here, the polymer core layer may contain multiple layers, including an intermediate layer interposed between two additional layers, the intermediate layer containing a first polymer, and the two additional layers containing one or more crosslinked second polymers and / or having a melting temperature higher than the melting temperature of the first polymer.

[0064] expansion As discussed herein, one characteristic of a thermal shielding device may be an increase in the separation distance between two metal layers of the device. The separation distance may increase due to mechanical properties acting when the polymer in the core layer melts. The increase in the separation distance between the metal layers may be caused by the expansion of the core layer and / or the formation of a gas layer between the two metal layers. The formation of the gas layer may be caused by one or more gas-generating materials and / or one or more gas-releasing materials in the polymer core layer. The gas may be water or any other compound having a boiling point below about 120°C. The gaseous compound may be in the liquid phase at room temperature, but may be in the gaseous phase upon heating, for example at the temperature of an extreme thermal event.

[0065] Some or all of the gas may originate from i) one or more compounds having one or more hydrated waters, ii) the decomposition of polymers, preferably catalyzed, iii) the reaction of flame retardants, from dry materials having water or other low-boiling point compounds, or iv) (in situations where the polymer core layer foams during layer formation) gases within the open or closed cells of the polymer core layer. The melting and expansion of the polymer core layer may increase the separation distance between the first and second metal layers. The generation and / or release of gases within the polymer core layer preferably occurs at the activation temperature Ta. The activation temperature is preferably at least 30°C higher than the polymer melting temperature (i.e., Ta≧Tm+30°C), thereby providing a sufficiently large processing window for forming the polymer core layer without activating the generation or release of gases. More preferably, Ta≧Tm+40°C, even more preferably, Ta≧Tm+60°C, and most preferably, Ta≧Tm+70°C.

[0066] Preferably, when the polymer core layer is heated during an extreme thermal event, some, substantially all, or all of the gas is released or generated. For example, the amount of gas generated in the polymer core layer during an extreme thermal event may be about 10% or more, about 25% or more, about 40% or more, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, or about 100%, based on the total amount of gas in the polymer core layer during or after the extreme thermal event.

[0067] One or more gas molecules may be formed by the decomposition of the polymer within the polymer core layer. Therefore, it may be desirable for the polymer core layer to contain a catalyst that accelerates the decomposition of the polymer. The catalyst can lower the temperature at which the decomposition of the polymer begins. The initiation of decomposition can be observed using thermogravimetric analysis and may be the temperature at which the mass of the polymer core layer decreases by about 2 percent relative to the mass at a reference temperature (the reference temperature may be about 25°C, about 50°C, about 80°C, or about 120°C) at a heating rate of about 10°C / min. Unless otherwise specified, the reference temperature is 120°C. The initiation of decomposition may be measured in an air atmosphere or an inert atmosphere. A preferred inert atmosphere is nitrogen. Unless otherwise specified, the initiation of decomposition is measured using an inert atmosphere of nitrogen (i.e., N2). If used, the catalyst is used in an amount sufficient to preferably lower the decomposition initiation temperature by about 20°C or more, more preferably about 40°C or more, even more preferably about 75°C or more, and most preferably about 100°C or more. Any catalyst that promotes the decomposition of the polymer and the formation of gas molecules as products may be used. It will be understood that the selection of catalysts may depend on the polymer in the polymer core layer. For example, catalysts known in the field of polymer recycling can be used. An example of a catalyst that can be used in the decomposition reaction is a zeolite catalyst. The catalyzed decomposition reaction preferably includes one or more pyrolysis reactions.

[0068] The expansion of the polymer core layer is preferably kept sufficiently low so that the heat flow through the thermal shielding device is primarily due to thermal conduction. For example, heat flow due to convection within the polymer core layer can generally be prevented. The expansion of the polymer core layer is preferably about 1000% or less, more preferably about 750% or less, and most preferably about 500% or less, thereby minimizing heat flow due to thermal convection.

[0069] It will be understood that different materials may produce different amounts of gas per gram of gas-releasing / gas-generating material. Therefore, the required amount of gas-releasing and / or gas-generating material may be specified based on i) the desired amount of gas (e.g., in moles) and / or ii) the required separation of the metal layers and / or iii) the desired volume expansion of the polymer core layer.

[0070] 1m of composite material 2 The amount of gas generated or released per unit area (i.e., measured over an area of ​​the surface of a metal layer exposed to high temperature / extreme thermal events) is approximately 0.01 mol / m². 2 In total, approximately 0.02 mol / m³ 2 In total, approximately 0.05 mol / m³ 2 In total, approximately 0.10 mol / m³ 2 Above, or approximately 0.15 mol / m³ 2 The above is acceptable. The amount of gas generated or released is approximately 1.00 mol / m³. 2 Below, approximately 0.90 mol / m³ 2 Below, approximately 0.80 mol / m³ 2 Below, approximately 0.70 mol / m³ 2 Below, approximately 0.60 mol / m³ 2 The following, or approximately 0.50 mol / m³ 2 The following may occur: The increase in the separation between the two metal layers due to the gas is preferably about 1 mm or more, about 2 mm or more, about 5 mm or more, about 10 mm or more, about 15 mm or more, about 20 mm or more, about 25 mm or more, or about 30 mm or more.

[0071] The expansion of the thermal shield may take the form of bulges in the metal layers, further increasing the distance between them. The bulges may have any shape. For example, the bulges may be curved (e.g., on one or both metal layers), hill-shaped (e.g., on one or both metal layers), elliptical (e.g., on one or both metal layers), generally flat (e.g., on one of the metal layers), or any combination thereof. The bulges may be localized to one or more areas of the thermal shield, or the bulges may pass through a substantial or entire area of ​​the thermal shield. When an extreme thermal event occurs, one or more areas may heat up first, and those areas may expand first. As time progresses and the thermal shield heats up further, the size of the areas may increase, and / or additional areas may expand. When the entire polymer core layer of the thermal shield is activated and gas is released or generated, the maximum gap may be at or near the center of the thermal shield, unless the thermal shield is welded, bolted, or otherwise constrained in that area. In constrained locations, for example, in the edge regions of metal layers attached to each other or other components, the change in their separation may be minimal or not change at all. The shape of the bulge may be symmetrical or asymmetrical with respect to the two metal layers. Depending on the structure of the thermal shield, it may be possible to control the location of the expansion. For example, one metal layer may be relatively thin and / or formed from a softer metal and / or have features such as folds, wrinkles, or creases that allow for favorable expansion of the metal layer (preferably without yielding). As another example, two metal layers may have similar thicknesses, be formed from the same metal, and have similar features so that the expansion is symmetrical. Expansion in one direction may be limited by the presence of another component such as a housing, frame, or panel.

[0072] As discussed herein, polymer core layers may expand when heated above a threshold temperature. Such expansion is preferably greater than that due to an increase in the specific volume of the material when the material is heated as a liquid or solid, and greater than that due to a phase transition from solid to liquid. For example, the expansion may result from a chemical reaction and / or a phase transition from solid or liquid to gas. Preferred chemical reactions include those that produce gas-phase products from solid or liquid reactants. The expansion of the core layer may be localized to one or more regions of the composite material, or it may extend throughout the composite material. For example, the expansion may result in one or more bulges in the composite material. A composite material having initially parallel metal layers may have metal layers that are no longer parallel within the region of the bulge. The percentage of core layer expansion is E c = 100% × Δt / t i It can be defined by, where Δt is the change in the thickness of the core layer after expansion (e.g., at the thickest and / or most expanded position), and t i This is the initial thickness of the core layer. If the expansion of the core layer is too low, the composite material may not be able to provide sufficient improvement in slowing down the flow of thermal energy through the composite material. Core layer E c The expansion percentage may be approximately 5 percent or more, approximately 10 percent or more, approximately 20 percent or more, approximately 40 percent or more, approximately 60 percent or more, approximately 80 percent or more, or 100 percent or more. If the core layer expansion percentage is too high, convective heat flow may become a problem. The core layer expansion percentage may be approximately 1000% or less, approximately 900% or less, approximately 800% or less, approximately 700% or less, approximately 600% or less, or approximately 500% or less.

[0073] foaming agent Examples of blowing agents that may be used include chemical blowing agents and hydrates. A blowing agent may also be a foaming agent. A chemical blowing agent can be any compound that reacts during extreme thermal events to produce a gas at high temperatures. Examples of chemical blowing agents include azodicarbonamide and sodium bicarbonate. Gases may also be produced by the reaction of monomers, for example, during condensation reactions, which produce water, carbon dioxide, or other low-boiling point molecules.

[0074] Hydrates contain one or more waters of hydration. Water is usually bound to a metal or a metal-containing basic compound. Compounds may have waters of hydration, coordination water, or both. Examples of basic compounds include metal salts, metal halides, metal carbonates, alkaline metal sulfates, alkaline metal halides, alkaline metal carbonates, alkaline earth metal sulfates, alkaline earth metal halides, alkaline earth metal carbonates, or any combination thereof. Preferred alkali metals include K and Na. Preferred alkaline earth metals include Ca and Mg. Preferred halides include bromides and chlorides. Metal salts, metal halides, metal carbonates. Preferred metals include Cr, Mn, Fe, Co, Ni, Cu, Cd, V, Al, Mg, or any combination thereof. The number of waters of hydration per molecule (or per metal atom) may be one or more, two or more, three or more, four or more, five or more, or six or more. Some or all of the water of hydration may be released during extreme thermal events. The number of waters of hydration released may be one or more, two or more, three or more, four or more, or five or more. Compounds having two or more waters of hydration may release or produce water at different temperatures.

[0075] For example, calcium chloride is a hygroscopic salt that can be anhydrous or have 1, 2, 4, or 6 waters of hydration. The hexahydrate is converted to tetrahydrate at about 30°C, releasing 2 waters of hydration. The tetrahydrate is converted to dihydrate at about 46°C, releasing 2 waters of hydration. The dihydrate is converted to monohydrate at about 175°C, releasing 1 water of hydration. The monohydrate is converted to an anhydrous compound at about 260°C, releasing the last water of hydration. The hexahydrate and tetrahydrate compounds generally release water at the polymer processing temperature. This can be advantageous when producing a foamed polymer core layer. Depending on the choice of polymer, other waters of hydration may be released during polymer processing. However, provided that the layer is formed at a temperature below 175°C, it may be possible to prepare a polymer core layer in dihydrate form (for example, by starting with a dihydrate, or by starting with a tetrahydrate or hexahydrate and removing some of the water of hydration). Similarly, the polymer core layer may be formed in monohydrate form, provided that the layer is formed at a temperature below 260°C. If the polymer core layer contains a dihydrate, one water of hydration is released when the material reaches a temperature of about 175°C, and the last water of hydration is released when the temperature rises to about 260°C.

[0076] The polymer core layer may contain a desiccant material containing water. When used, the desiccant is preferably supplied with or filled with a predetermined amount of water. Some of the water may be released during the formation of the polymer core layer (as described herein with respect to compounds containing hydration water), but it is preferable that some or all of the water remains in the desiccant after the polymer core layer is formed. The water in the desiccant within the polymer core layer may be released after extreme thermal events as the polymer core layer is heated. Examples of desiccants include molecular sieves, silica gel, anhydrocel (CaSO4), anhydrone (Mg(ClO4)2), ascarite, desicchlora (Ba(ClO4)2), alumina (Al2O3), mikohbite (68% NaOH, 32% cottony mica), magnesium perchlorate, barium oxide, phosphorus pentoxide, lithium perchlorate, calcium chloride, sodium hydroxide, barium perchlorate, calcium oxide, magnesium oxide, and potassium hydroxide. Examples of molecular sieves include zeolites.

[0077] In some cases, the release of water by hydrates or desiccants is an endothermic reaction. Therefore, some of the thermal energy from extreme thermal events is consumed in the production of water. This can be useful in delaying the heat flow through thermal shielding devices.

[0078] The polymer core layer may be formed as a foamed core layer. Here, the thickness of the core layer increases with temperature (K), for example, with a linear increase in volume according to the ideal gas law. Since the area of ​​the thermal shielding device can be nearly constant, expansion can occur in the thickness direction, and the resulting thickness increases nearly linearly with temperature (K).

[0079] The polymer core layer may contain one or more flame retardants (i.e., flame retardant compounds). The flame retardants may be halogen-containing or halogen-free. Any flame retardant that suppresses the combustion of the polymer in the core layer. Preferred flame retardants have an endothermic reaction that generates gas (e.g., at temperatures above critical temperatures during extreme thermal events) and / or consumes thermal energy. Examples of flame retardants include inorganic flame retardants, organic halogen compounds, organophosphorus compounds, inorganic phosphate compounds, organophosphate compounds, and graphene. Examples of inorganic flame retardants that can be used include aluminum hydroxide, magnesium hydroxide, huntite, hydromagnesite, red phosphorus, boron compounds, or any combination thereof. Boron compounds may be borates. Examples of organic halogen compounds include organochlorine and / or organobromine. Preferably, organohalogens are used with synergists, such as antimony-containing compounds. Preferred synergists include antimony oxide, antimony pentoxide, and sodium antimonate. Examples of organophosphorus compounds include organophosphates, phosphonates, and phosphinates. Organophosphorus compounds may contain halogens, preferably chlorine or bromine. Other organophosphorus compounds do not contain halogens. Flame retardants may preferably be halogen-free so as to reduce or eliminate exposure to halogenation decomposition products.

[0080] The flame retardant preferably prevents the polymer from burning for a certain period of time. For example, if one metal layer is directly exposed to a flame, the delay in the burning of the polymer allows the other metal layer to be maintained at a temperature of 600°F or less for 5 minutes or more, preferably 7 minutes or more, and most preferably 10 minutes or more.

[0081] The polymer core layer may contain reinforcing fillers. Preferred reinforcing fillers are mineral fillers. The polymer layer may contain metal fibers or metal particles. Metal fibers or metal particles in the polymer core layer can increase the thermal conductivity of the core layer. Preferably, the amount of metal fibers and metal particles in the polymer core layer is small enough so that the thermal conductivity of the layer is about 2.00 W / m·K or less, preferably about 1.00 W / m·K or less, and more preferably about 0.80 W / m·K or less. Preferably, the amount of metal in the polymer core layer is about 10.0 volume percent or less, more preferably about 6.0 volume percent or less, even more preferably about 3.0 volume percent or less, and most preferably about 2.0 volume percent or less. The polymer core layer may be completely metal-free or substantially metal-free (e.g., 1.0 volume percent or less, or 0.5 volume percent or less).

[0082] Composite materials may lack welds, bolts, or other connectors that limit the core material's ability to expand within the area where thermal shielding is most desired. Bolts, welds, and connectors are preferably located away from the shielding area. For example, connections through both metal layers may occur in the peripheral or edge areas of the composite material. They may also occur in extension areas where the composite material extends away from the heat source. Bolts, welds, and connectors within the shielding area may be attached to only one of the metal layers, and as a result, the distance between the metal layers is not constrained by the connector. Therefore, the core layer may expand even if one of the metal layers is connected to another component.

[0083] A first metal layer and a second metal layer can be connected using a single connector or a meltable connector. Since the meltable connector can melt during extreme thermal events, the first and second metal layers can be separated from each other. The meltable connector may contain or be formed from a polymer that melts at any of the temperatures specified herein for the core layer. The meltable connector may contain or be formed from a polymer specified herein for the core layer.

[0084] edge seal Two or more metal layers may typically be sealed together along one or more edges. Edge sealing may improve the composite's ability to expand and retain gases generated or released during extreme thermal events. Two metal layers may be sealed by joining them together directly or indirectly. For example, two metal layers may be joined together using a third metal layer. As another example, one of the metal layers may have an extended region that is curved to reach or cover the other metal layer so that the two metal layers can be directly attached. As yet another example, there may be a region near the edge of the metal layers where there is no polymer core layer, so that the surfaces of the two metal layers in that region can contact and join with each other.

[0085] It will be understood that the edge region may be located sufficiently far from the heat generated by extreme thermal events that cause the polymer core layer to function as a seal at the edge region. Therefore, in order to achieve expansion of the core layer, it may not be necessary to seal or join the two metal layers, especially if the expansion is localized to one or more regions (e.g., away from the edge).

[0086] Figure 5 shows an embodiment of a shielding device comprising a metal outer layer, separated by layers containing one or more gases that generate material. The gas-generating material may be a material that generates or releases gas when heated. The gas applies outward pressure to the metal layers, separating them. In some cases, it may be necessary to seal one or more, or even all, of the edges of the metal layers together to reduce or prevent gas leakage. The separation of the metal layers may be localized in one or more areas, or it may extend essentially across the entire area of ​​the metal layers. Naturally, edges that are sealed together may be difficult to inflate. However, if both expansion and sealing at the edges are required, edge sealing can be achieved using one or more edge expansion components that can increase the height of the seal (i.e., the distance between the two metal layers at the edge). For example, the seal may include one or more folds, pleats, grooves, or other structures that can be expanded with low force. For example, if the core layer is in a molten state (above its glass transition temperature and above its melting temperature), the edge seal expansion component may require a force of less than 25% of the yield stress of the metal layer in the forward direction to increase the seal height. The edge seal expansion component may make it possible to increase the edge height by approximately 5%, 15%, 35%, 70%, 100%, 175%, or 250% or more.

[0087] Any mounting components or methods used for mounting metals and / or composite materials may be used for mounting the thermal shielding device. Examples of mounting include welding, bolting, and riveting. Mounting may use one or both of the metal layers.

[0088] The thermal shielding device may be mounted on a device capable of generating thermal energy. The thermal shielding device may be mounted on an assembly, frame, or panel so as to be positioned above the device capable of generating thermal energy.

[0089] In many applications, thermal shielding devices are mounted or installed on assemblies, frames, or panels. When thermal shielding devices are installed, expansion of the device in the area where it is installed may be difficult. It may be possible to install thermal shielding devices only in locations where expansion is not significant. For example, thermal shielding devices may be installed only in edge areas or nearby, extension areas or nearby, bends or nearby, or any combination thereof. Thermal shielding devices may include one or more extension areas, as shown in Figure 7. Extension areas may be areas where shielding is required. Extension areas may be used to install thermal shielding devices. When extension areas are used to install thermal shielding devices, it is preferable that the extension areas are in locations where shielding is not required, or where a reduction in thermal shielding is required.

[0090] A thermal shielding device includes one or more shielding regions 100 in which the device helps reduce the flow of thermal energy. The shielding regions preferably include or consist of composite materials or laminates as taught herein. The thermal shielding device may include one or more extension regions 102. The thermal shielding device may also function to reduce the flow of thermal energy within the extension region(s), although the requirements for thermal shielding in these regions are usually reduced. The extension regions may be used to mount the thermal shielding device to an assembly, panel, frame, or other component. The extension regions may include the same material as the shielding region (e.g., composite material) or may be formed from different materials. As shown in Figure 7, the extension region 102 may be used as a mounting position 104. The mounting position 104 may be located in an edge region 106 of the thermal shielding device, as shown in Figure 8. Preferably, the edge region is about 150 mm or less, about 100 mm or less, about 50 mm or less, or about 25 mm or less from the edge of the thermal shielding device. The extension region may include a bent portion or projection angled with respect to the shielding region. The bent portion or projection 108 may be substantially perpendicular to the shielding region 100, as shown in Figure 9. The bent portion or projection 108 may be formed from the same material as the shielding region 100 or from a different material. For example, the projection 108 may be formed from a substantially integral material, as shown in Figure 9.

[0091] It may also be possible to mount a thermal shield using only one of the metal layers. In this case, the mounted layer may be in a nearly fixed position, while the other layers may be movable away from the mounted layer.

[0092] The gas within the polymer core layer (e.g., before and / or after expansion) and / or the space between the metal layers is preferably substantially free of oxygen molecules (i.e., O2). The amount of oxygen molecules within the polymer core layer and / or the space between the metal layers is preferably about 24 percent or less, more preferably about 18 percent or less, even more preferably about 10 percent or less, even more preferably about 5 percent or less, and most preferably about 1 percent or less, based on the total number of gas molecules in the polymer core layer. The amount of oxygen molecules may be about 0 percent or more.

[0093] The separation of the metal layers can be achieved by the action of a spring. For example, the apparatus may include one or more springs in a non-equilibrium state (compressed or elongated). Preferably, the springs are in a compressed state. The springs are prevented from returning to equilibrium by one or more components of the apparatus. For example, the springs may be embedded in a polymer in a solid state. The polymer in a solid state may be a semi-crystalline polymer whose melting temperature and / or crystallization temperature is below its temperature. The polymer in a solid state may be a glassy polymer whose glass transition temperature is below its temperature. During use, it is preferable that the polymer remains in a solid state until it is exposed to a temperature high enough to activate the expansion function of the apparatus. Here, the expansion feature can be activated by melting or softening the polymer. This involves exposing the polymer to a temperature at or near its melting temperature (e.g., at least about T m -10℃, approx. T m , about T m +30℃, approx. T m +40℃, approx. T m +50℃, approx. T m +60℃, or approximately T m This may involve heating (up to a temperature of +80°C). When the polymer is heated, a force is applied that allows the spring to return to its equilibrium length, separating the metal layers.

[0094] During extreme thermal events, the thermal shielding device may be exposed to heat from a heat source 116, typically located on one side of the device. The heat causes gas generation and / or gas expansion within the core layer. The core layer containing gas 110 applies pressure 114 onto the metal layer. In this case, the metal layers can be separated from each other, and the thickness of the core layer 110 usually increases. In addition to, or instead of, the core layer expanding, it will be understood that a separate gas phase may be formed between the two metal layers. The two metal layers can be sealed together at the edges to prevent gas leakage, as shown in Figure 10 (112).

[0095] A thermal shield may include a fracture point, e.g., a puncture, scoring, thinning area, or other feature resulting in one of the metal layers fracturing at a given location. Fracture of a metal layer may occur due to pressure generated within the core layer, e.g., during extreme thermal events. It will be understood that the fracture point may include one or more points, one or more substantially straight lines, or one or more substantially curved lines. Fracture points can be used to help separate metal layers. The fracture point is preferably in or near the edge region of the thermal shield. Fracture points can be used in particular when the edge region is sealed (e.g., when two metal layers are welded to each other or otherwise joined together). A thermal shield may have one metal layer that is a fixed layer and one metal layer that becomes movable after fracturing, and the thermal shield may separate from the fixed metal layer. A thermal shield with a fracture point is shown in Figure 11. With respect to Figure 11, a barrier layer including a metal layer 122 and / or a fracture point 120 may be attached to a fixed metal layer 124. Attachment may be made via an edge region component 128. It will be understood that the edge region component is formed from one of the metal layers or from different portions. The thermal shielding device preferably includes a core layer 126 which preferably generates and / or releases gas when heated. The core layer 126 may extend to the edge region component 128, or a gap may exist in the edge region where there is no core layer material. For example, as shown in Figure 6, the core layer material terminates either before or at a fracture point. Fracture at a fracture point may occur due to the pressure of gas within the core layer, for example, during extreme thermal events. Examples of fracture points include perforations, scoring, notched regions, and thinned regions.

[0096] Figures 12A and 12B show a thermal shielding device mounted in an edge region and include one or more features for rupturing at a predetermined location. Figure 12A shows the structure of the metal layer 122 before rupture, and Figure 12B shows the structure of the metal layer 122 and / or barrier layer after rupture, where this layer is moving away from the fixed metal layer 124. The thermal shielding device may be mounted to another component using a mounting component 130. The mounting component may also mount both metal layers of the composite material together. After the core layer expands 136, the movable metal layer 122 may rupture at the rupture point and move away from the fixed metal layer 124, particularly within the shielding region. The core layer is shown to terminate before or near the rupture point, but may extend beyond the rupture point or to the edge.

[0097] The thermal shielding device may be connected to an assembly, panel, frame, or other component 133 using a coupler or mounting component 132, as shown in Figure 13. The coupler or mounting component may be connected to both metal layers. Preferably, the coupler or mounting component is connected to only one of the metal layers, thereby providing a fixed (or connected) metal layer and a movable metal layer that moves after an extreme thermal event.

[0098] It will be understood that extreme thermal events can cause separation of metal layers in only one or more regions, as shown in Figure 14. For example, thermal energy can cause only localized melting and / or localized gas generation or release.

[0099] Heat 116 on one or both sides of the heat shielding device can first heat the first region 54 of the polymer core layer.

[0100] In one embodiment, the core layer initially comprises a polymer in a solid state 56 (e.g., having a degree of crystallinity and / or a glass transition temperature below its glass transition temperature). When heated, the polymer melts and / or softens, preferably above its glass transition temperature, into a liquid state 58 without a crystalline phase. The melting and / or softening can be localized in the heated region.

[0101] When the temperature reaches a critical point or activation temperature, gas may be released or generated within the heating region. The gas may cause the core layer to expand 59 in the heating region 54. The expansion may be on one or both sides of the thermal shielding device. The expansion may be symmetrical. The heating region 54 may expand over time due to additional heating. Due to the size of the thermal shielding device, there may be areas where the core layer is still solid 56 even when the core has expanded within the heating region 54 (e.g., by 25% or more, 50% or more, 75% or more, or 100% or more). The expanded core layer 59 causes separation of the metal layers 12, 14 in or near the heating region 54.

[0102] The thermal shielding device may include one or more components within the core layer 16 to store potential energy 80. When the polymer is heated (e.g., melted or softened), the stored potential energy is released, causing the core layer to expand and increasing the separation distance 90 between the metal layers 12, 14. The potential energy may be stored in one or more springs 82, as shown in Figure 15. The springs may be spaced apart, preferably throughout the entire area of ​​the thermal shielding device. The springs are preferably positioned such that the thickness of the core layer and / or the spacing between the metal layers increases as the polymer melts or softens, and the springs return from a compressed state to an uncompressed state.

[0103] Using one or more features, the separation distance 90 between metal layers can increase during extreme thermal events.

[0104] One or both of the metal layers 12, 14 may include one or more features that allow the layer to expand (e.g., in length, width, or area) without yielding to the metallic material. For example, the metal layer may include one or more folds 140, creases, wrinkles, or folds, as shown in Figure 16.

[0105] When the area of ​​the heat shielding device is heated, a portion of the polymer in the core layer may melt and / or soften, as shown in Figure 17 (58).

[0106] As the metal layers separate, they can expand 142 by removing some or all of the folds, wrinkles, creases, or folds, as shown in Figure 18. This allows the metal layers to separate in areas where the metal layers do not expand, contract, or yield.

[0107] The thermal shielding device may have potential energy from the metal layers (or both metal layers) in a compressed state 158. For example, one or more metal layers may have a curved configuration 150 before forming the thermal shielding device. During the formation of the device, the metal layers may be compressed 154, held in a compressed state by, for example, a core layer. As the polymer in the core layer melts or softens, the metal layers may return to their curved configuration and / or uncompressed configuration. This may increase the thickness of the core layer and / or the separation distance between the metal layers. Figure 19A shows the curved metal layers before forming the thermal shielding device. Figure 19B shows the thermal shielding device with the metal layers in a compressed state. The metal layers may be maintained in a flat orientation by physical or mechanical means. For example, the metal layers may be attached to a core layer. As another example, the layers may be attached via one or more connectors (for example, within the central region of the thermal shielding device). The connectors are preferably meltable connectors. It will be understood that, during heating, for example, during extreme thermal events, the flat orientation should be reversed. In an uncompressed state, such metal layer(s) preferably has a convex outer surface 152.

[0108] The edges of the thermal shielding device may be covered with edge covering components 170. The edge covering components may be expandable (preferably without yielding) when the thickness of the core layer increases and / or when the separation distance between the metal layers increases. For example, the covering components may include one or more folds, wrinkles, pleats, or creases 172, as shown in Figure 20A. When the core layer expands 174, at least one or more of the folds, wrinkles, pleats, or creases may be removed, so that the edge covering components can expand without yielding. Preferably, the edge covering components maintain contact with the metal layers and / or seal the edges before and during the expansion of the core layer.

[0109] A thermal shielding device can also help provide electromagnetic interference (EMI) shielding to one or more components.

[0110] The thermal shielding device preferably has good vibration damping characteristics characterized by a composite loss coefficient of about 0.010 or more at a temperature of about 50°C and a frequency of about 100 Hz.

[0111] Batteries and / or electric vehicles (i.e., EVs) The thermal shielding devices taught herein can be used in systems including a battery. The thermal shielding devices may shield a compartment from a battery if extreme thermal events originate from or affect the battery. For example, a battery may be located in an electric vehicle, and the thermal shielding devices may shield the compartment of the EV. The electric vehicle may be a hybrid EV or a plug-in EV. Preferably, the battery supplies power to an electric motor that drives the vehicle. The EV preferably does not have an internal combustion engine. The battery may include one or more battery cells for providing power.

[0112] The thermal shielding device may be positioned substantially horizontally such that the front of the thermal shielding device generally faces vertically. Preferably, the barrier layer of the thermal shielding device faces upward in the vertical direction. Preferably, the thermal shielding device is positioned at least partially under the occupant compartment, at least partially under the seats, at least partially under the trunk, at least partially under the flanks, or any combination thereof.

[0113] The thermal shield may be used as a battery cover, a battery housing, or a separate component spaced apart from the battery. The thermal shield may shield any vehicle compartment from the battery. The compartment shielded by the thermal shield may include a storage area, a computer or other electronic control area, or a passenger area. Preferably, the thermal shield shields the passenger compartment. The compartment may be above, below, in front of, or behind the battery. As described herein, the thermal shield may reduce the heat flow through the device and therefore reduce the heat flow to the shielded compartment. A battery cover may be positioned above or in front of one or more battery cells. The battery cover may generally be horizontal, angled, or substantially vertical.

[0114] The thermal shield may be substantially flat. The thermal shield may be formed from a flat sheet having a uniform thickness and / or a flat surface. For example, the thermal shield may be formed by press molding or press working. The thermal shield may have one or more regions having a flat surface. The thermal shield may have a surface that includes (or has as a whole) a region having a shape similar to that of the battery housing. There may be gaps above or below the battery cover (e.g., for a substantially horizontal battery cover). There may be gaps in front of or behind the battery cover (e.g., for a substantially vertical battery cover). Gaps may exist between the battery and the battery cover, and / or between the battery cover and the crew compartment.

[0115] A laminate as taught herein having a barrier layer (e.g., including a metal layer and a core layer) can be processed into a thermal shielding device by a method including one or any combination of the following steps: cutting a sheet or roll of the laminate to a predetermined length; cutting a blank from a sheet or roll of the laminate; pressing or otherwise forming the blank (e.g., so that the blank has a non-planar shape); sealing or winding the edges of the laminate; or cutting one or more holes in the laminate or blank (e.g., for attaching the laminate to a component or structure).

[0116] The thermal shield may be mounted on the vehicle frame or vehicle panel. The thermal shield may be mounted on a container (e.g., a housing) that holds one or more battery cells. The thermal shield may be oriented to provide a barrier between a heat-generating device (e.g., during an extreme thermal event) and the compartment or area being shielded. The thermal shield may be large enough to provide a substantial or complete barrier to the compartment or area being shielded.

Claims

1. i. The first metal layer and ii. The second metal layer, iii. A core layer (preferably an expandable core layer) interposed between the first metal layer and the second metal layer, iv. A thermal shielding device comprising a barrier layer that provides a thermal barrier (e.g., a thermal insulator), an electrical barrier (e.g., an electrical insulator), or both.

2. The thermal shielding device according to claim 1, wherein the barrier layer is directly adjacent to the first metal layer, or the insulating layer is attached to the first metal layer.

3. The thermal shielding device according to claim 2, wherein the barrier layer is attached to the first metal layer using an adhesive (for example, a pressure-sensitive adhesive).

4. The thermal shielding device according to any one of claims 1 to 3, wherein the core layer and the first metal layer are interposed between the second metal layer and the barrier layer (for example, the layers are arranged in the following order: the barrier layer, the first metal layer, the core layer, and the second metal layer).

5. The thermal shielding device according to any one of claims 1 to 4, wherein the barrier layer is an outer layer of the device (for example, facing one or more battery cells).

6. The barrier layer and the core layer are interposed between the first metal layer and the second metal layer (for example, the layers are arranged in the following order: the first metal layer, the barrier layer, the core layer, and the second metal layer), according to any one of claims 1 to 3.

7. The heat shielding device according to any one of claims 1 to 6, wherein the barrier layer comprises an aerogel, preferably the aerogel is an expandable material, and preferably the volume expansion of the aerogel when heated to a temperature of about 200°C or higher (e.g., 250°C or higher, or 300°C or higher) is about 200% or more, about 300% or more, about 400% or more, or about 500% or more.

8. The thermal shielding device according to any one of claims 1 to 6, wherein the barrier layer comprises a composite material containing inorganic fibers.

9. The heat shielding device according to claim 8, wherein the inorganic fibers include glass fibers and the composite material includes silicone rubber, or preferably both.

10. The heat shielding device according to claim 9, wherein the composite material comprises one or more layers of the silicone rubber (for example, two or more layers, or three or more layers) and one or more layers of the glass fiber (for example, two or more layers, or three or more layers).

11. The thermal shielding device according to any one of claims 1 to 6, wherein the barrier layer comprises one or more inorganic compounds.

12. The thermal shielding device according to claim 11, wherein the one or more inorganic compounds include a mineral filler.

13. The thermal shielding device according to claim 12, wherein the mineral filler comprises a silicate, preferably aluminum silicate.

14. The thermal shielding device according to any one of claims 11 to 13, wherein the barrier layer includes a mica sheet, a high-resistivity coating, or both.

15. The barrier layer is a flame-retardant coating. Preferably, it includes a flame-retardant coating containing a carbon powder additive, Preferably, the flame-retardant coating has a combustion resistance on an aluminum surface of 6 hours or more when tested at 700°C (preferably at 800°C, more preferably at 900°C, and most preferably at 982.2°C), according to any one of claims 1 to 14.

16. The thermal shielding device according to any one of claims 1 to 15, wherein the core layer contains expandable graphite.

17. The thermal shielding device according to claim 7, wherein the aerogel is a carbon aerogel, silica aerogel, alumina aerogel, chromia aerogel, graphene aerogel, or tin oxide aerogel.

18. The thermal shielding device according to claim 7 or 17, wherein the aerogel has a thermal conductivity of about 0.400 W / m·K or less, preferably about 0.070 W / m·K or less, more preferably about 0.040 W / m·K or less, even more preferably about 0.025 W / m·K or less, and most preferably about 0.021 W / m·K or less, as measured at about 23°C.

19. The thermal shielding device according to any one of claims 1 to 18, wherein the barrier layer is sufficiently ductile so that the thermal shielding device can be formed by press-forming the layer and / or so that the thermal shielding device can be wound onto a roll.

20. The thermal shielding device according to any one of claims 1 to 19, wherein the barrier layer is attached to the first metal layer using an adhesive, preferably a pressure-sensitive adhesive.

21. The aforementioned core layer is i) A first additive selected from the group consisting of flame retardant compounds and gas-producing compounds, ii) A polymer core layer comprising a second additive selected from the group consisting of antioxidants, reinforcing fillers, and mineral fillers, Preferably, the thermal shielding device according to any one of claims 1 to 20, wherein the polymer core layer comprises the first additive and the second additive.

22. The heat shielding device according to any one of claims 1 to 20, wherein the core layer is a polymer core layer containing one or more gas-generating compounds that generate a gas (preferably carbon dioxide or water) at a temperature of about 100°C to about 320°C.

23. The heat shielding device according to any one of claims 1 to 22, wherein the first metal layer and the second metal layer are formed from the same material (preferably steel or aluminum).

24. The first metal layer and the second metal layer are formed from different materials (for example, the first metal layer is a steel layer and the second metal layer is an aluminum layer). The heat shielding device according to any one of claims 1 to 22, wherein the ratio of the thickness of the second metal layer to the thickness of the first metal layer is preferably about 1.4 or more.

25. The heat shielding device has a thermal conductivity of approximately 0.015 to approximately 4 W / m·K, and when heated to a temperature of approximately 100°C or higher, the core layer increases the separation distance between the first metal layer and the second metal layer in one or more regions, and the thickness of the heat shielding device increases by approximately 15 percent or more in one or more regions. Preferably, the polymer core layer generates or releases a sufficient amount of gas at a temperature of about 100°C or higher, causing the separation of the metal layers and the increase in the thickness of the heat shielding device in one or more regions. Preferably, the core layer (for example, the polymer core layer is one or any combination of the following: i) The core layer contains one or more compounds having water of hydration, ii) The core layer, excluding any voids and / or pores within the core layer, has a density of approximately 0.90 to approximately 2.00 g / cm³ at a temperature of approximately 25°C. ３ It is formed from a material having a density of, iii) The thermal shielding device according to any one of claims 1 to 24, characterized in that the core layer comprises a polymer, and the thermal shielding device preferably comprises a catalyst that accelerates the decomposition of the polymer so as to increase the pressure between the metal layers.

26. The heat shielding device has a thickness of approximately 0.70 mm to approximately 5.0 mm, and the ratio of the thickness of the core layer to the thickness of the heat shielding device is approximately 0.15 to approximately 0.

45. The ratio of the thickness of the barrier layer to the thickness of the heat shielding device is approximately 0.15 to approximately 0.

45. Preferably, the heat shielding device is about 0.05 m ２ Above and / or approximately 20.0 m ２ A heat shielding device according to any one of claims 1 to 25, having the following area.

27. A battery cover for a plug-in electric vehicle, comprising a heat shielding device according to any one of claims 1 to 26.

28. Preferably, the core layer is a polymer core layer having a thermal conductivity of about 0.05 to about 4 W / m·K. Preferably, the battery cover is positioned between a vehicle battery that supplies power for an electric motor that drives the vehicle and the passenger compartment, in the use of the battery cover according to claim 27 in an automobile.

29. The battery cover according to claim 27, An electric motor for driving one or more wheels of the vehicle, A system comprising one or more battery cells for supplying power to the electric motor, The battery cover is placed on top of one or more battery cells. Preferably, the battery cover is approximately horizontal. Optionally, the battery cover is attached to a container that holds one or more battery cells, and / or the battery cover is attached to the vehicle body and positioned below the occupant compartment. Optionally, the system includes a gap above or below the battery cover to allow for an increase in the separation between the first metal layer and the second metal layer.

30. The system according to claim 29, wherein the battery cover is arranged such that the barrier layer faces one or more battery cells.

31. The system according to claim 30, wherein the barrier layer has an electrical resistivity sufficiently high to prevent or reduce arc discharge or other electrical disturbances.

32. A material system comprising a composite material, wherein the composite material is i. The first metal layer and ii. The second metal layer, iii. A core layer (preferably an expandable core layer) interposed between the first metal layer and the second metal layer, The material system comprises a barrier layer that provides a thermal barrier (e.g., a thermal insulator), an electrical barrier (e.g., an electrical insulator), or both.

33. The material system according to claim 32, wherein the barrier layer is provided as a separate material.

34. The material system according to claim 32, wherein the composite material includes the barrier layer.

35. The material system according to any one of claims 32 to 34, wherein the composite material is in the form of a coil.

36. The material system according to claim 35, wherein the coil (for example, each layer of the coil) is sufficiently ductile so that the coil can be press-formed.

37. The material system according to any one of claims 32 to 36, wherein the material system is further characterized by one or any combination of the features described in claims 2 to 26.

38. A method comprising the step of press-working or punching a material system according to any one of claims 32 to 37 in order to form a heat shielding device (for example, to form a heat shielding device according to any one of claims 1 to 26).

39. A method for applying the material system according to claim 33 to a battery, comprising the steps of: positioning the barrier layer on a housing containing one or more battery cells; positioning the composite material on the barrier layer; and attaching the composite material to the housing.

40. The heat shielding device according to any one of claims 1 to 14, wherein the heat shielding device includes a high resistivity coating.

41. The heat shielding device according to claim 40, wherein the high resistivity coating comprises a thermoplastic composition containing polyvinyl chloride (PVC).

42. The thermoplastic composition is applied as a coating containing one or more solvents, preferably the one or more solvents comprising one or more aromatic solvents, one or more alcohols, one or more ketones, one or more alkanes, or any combination thereof, more preferably the solvent comprising one, two, three, four, or all of toluene, phenol, n-alcohols having 3 to 6 carbon atoms (preferably having 3 or 4 carbon atoms), ethyl alcohol, and ketones (e.g., branched ketones), according to claim 41.

43. The thermal shielding device according to claim 41 or 42, wherein the thermoplastic composition contains a plasticizer.

44. The thermal shielding device according to claim 43, wherein the concentration of the plasticizer is sufficiently high so that the barrier layer can be processed by pressing, bending, drawing, or other forming processes without rupture or delamination of the barrier layer.

45. The thermoplastic composition containing PVC comprises a flame retardant, a carbonizing agent, or both, according to any one of claims 41 to 44.

46. The heat shielding device according to claim 45, wherein, based on the total weight of the barrier layer, the total concentration of the PVC, the flame retardant and / or carbonizer, and any plasticizer is about 98% by weight or more, about 99% by weight or more, about 99.5% by weight or more, or about 99.8% by weight or more, or about 100% by weight.

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