Flame and Thermal Barrier Materials

Abstract

A laminate having thermal protection and flame retardant properties is disclosed. The laminate may include a flame retardant layer and an aerogel layer, where the laminate has opposing front and rear surfaces, the flame retardant layer defines at least a majority of the front surface, and the laminate has a thickness of 25.4 millimeters (mm) or less. TIFF2025503894000011.tif80170

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 301,897, filed January 21, 2022, and U.S. Provisional Patent Application No. 63 / 481,124, filed January 23, 2023, which are incorporated by reference in their entireties.

[0002] A. Field of the Invention The present invention generally relates to a laminate that can be used as a flame and / or heat protection material for any type of manufactured article. In some aspects, the laminate can be used to protect manufactured articles (e.g., batteries, electronic devices, and / or non-conductive protective materials) from environments that may be exposed to high temperatures (e.g., above 500°C) for a period of time (e.g., 1 minute to 90 minutes). [Background technology]

[0003] B. Description of Related Art Modern society is becoming more and more prevalent with electrification. One example of this is the rapid pace of electrification in the transportation sector. In particular, transportation vehicles such as cars, trains, and planes are moving away from combustion engine technology and instead being equipped with electric motors that rely on battery systems. These battery systems can be complex systems that rely on chemicals, chemical reactions, electronic components, and other materials to store and discharge electricity for the electric motors.

[0004] One problem associated with battery systems used in electric vehicles is that they are large and store and release much more energy than battery systems used in typical transportation vehicles that rely primarily on combustion engine technology. A specific problem is that batteries used in electric vehicles, when subjected to mechanical damage (e.g., vehicle accidents, wiring or electronic system malfunctions, etc.), exposed to temperatures outside of their operating range, or subjected to rapid charge / discharge events, can cause relatively large explosions, large fires, and / or release of large amounts of corrosive chemical fumes compared to batteries used in vehicles that rely on combustion engines. Lithium-ion based battery cells used in electric vehicles can ignite and / or explode at temperatures in excess of 500° C. In contrast, a vehicle fire, for example, due to a vehicle accident, can generate heat in excess of 1,500° F. (815° C.). If an accident occurs in an electric vehicle and a fire breaks out, a period of time is required to extinguish the fire and / or exit and remove the vehicle before the battery ignites and / or explodes. As society becomes more electrified, and in particular the electrification of transport infrastructure, and batteries become more energy dense, the risk of electric vehicle fires and battery fires and explosions will also increase.

[0005] Traditional insulating materials such as foams, polymers, and elastomers have been used to provide some degree of thermal protection for the battery systems of electric vehicles. Unfortunately, these traditional materials still face limitations. For example, while polymer foams have low thermal conductivity, which mitigates heat transfer, their thermal diffusivity, i.e., the thermal conductivity of a material divided by its density and specific heat capacity, tends to be higher than other insulating materials. The higher the thermal diffusivity (meaning the higher the thermal conductivity relative to the specific heat capacity and density of the material), the faster the temperature of such polymer foams tends to rise as they continue to heat, such that heat propagates faster. Other polymer and elastomeric materials may have lower thermal diffusivities than polymer foams, but tend to have higher thermal conductivities. In addition, heat concentrated in one portion of such a traditional insulating material may not be distributed across its entire surface, accelerating the transfer of heat through the thickness of the material to the surface of the component it is designed to protect. Thus, traditional insulating materials may not provide the desired level of thermal protection in some applications.

[0006] Furthermore, in some systems, insulating materials may be subject to severe space constraints. Because traditional insulating materials are usually relatively thick and / or stiff, such constraints may limit the amount of traditional insulating material that may be included in a system, further limiting the thermal protection provided by the material or rendering such materials unusable in the system. Compounding these constraints, polymers, elastomers, and foams often have relatively high coefficients of thermal expansion, creating more severe space constraints when these materials are heated. Summary of the Invention

[0007] A discovery has been made that provides a solution to at least one or more of the aforementioned problems associated with providing thermal protection to an article of manufacture, substrate, or system (e.g., an electric battery system). In one aspect, it has been found that a laminate including a flame retardant layer having a flammability rating in accordance with at least one flammability standard (e.g., UL94 5VB or UL94 5VA rating) and an aerogel layer can provide good thermal protection properties to the article of manufacture, substrate, or system (article of manufacture, substrate, or system may be used interchangeably throughout this specification). In such a laminate, the synergy between the flame retardant layer and the aerogel layer can provide thermal protection of the substrate in terms of heating rate and / or equilibrium temperature of the substrate beyond what would be expected from the sum of their parts, especially when the thickness of the aerogel layer is thin (e.g., less than 0.5 mm). Without wishing to be bound by any particular theory, it is believed that the aerogel layer, having low thermal conductivity and low thermal diffusivity, effectively retards heat transfer from the flame retardant layer and into the substrate.

[0008] As an example, the laminate of the present invention, when attached to a surface of a substrate, can maintain the temperature of the substrate (e.g., the surface temperature of the substrate) at or below 500°C when the laminate is exposed to a temperature of greater than 500°C, preferably between 500°C and 1,500°C, or more preferably between 700°C and 1,200°C, for 1 minute to 90 minutes, preferably at least 5 minutes. This can be advantageous, for example, in that it provides a longer time before the substrate (e.g., the battery system of an electric vehicle) reaches a temperature at which it may fail. This can be particularly advantageous when used to protect the battery system of an electric vehicle, as it can provide a longer time for the vehicle occupants to exit the vehicle after an accident before the electric vehicle battery catches fire, explodes, and / or releases toxic chemicals. It can also provide a longer time for first responders (e.g., firefighters) to extinguish the fire before the electric vehicle battery catches fire, explodes, and / or releases toxic chemicals. In particular, the laminates of the present invention can be relatively thin (e.g., 25.4 millimeters (mm), 20 mm, 15 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, 0.1 mm or less) and / or relatively flexible (e.g., can be rolled (see, e.g., FIG. 5 ) and / or have a bend radius). An advantage of the flexibility of the laminates of the present invention is that they can be used in applications with severe space constraints (e.g., electric vehicle battery systems and battery packs).

[0009] In one aspect of the invention, a laminate is disclosed that includes a flame retardant layer and a porous material layer (e.g., a foam layer or an aerogel layer, preferably an aerogel layer). The laminate can have opposing front and rear surfaces, where the flame retardant layer defines at least a majority of the front surface. The laminate can have a thickness of 25.4 millimeters (mm), 24 mm, 23 mm, 22 mm, 21 mm, 20 mm, 19 mm, 18 mm, 17 mm, 16 mm, 15 mm, 14 mm, 13 mm, 12 mm, 11 mm, 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, 0.1 mm or less, or any range therein. In other aspects, the laminate can have a thickness of more than 25.4 mm (e.g., 26, 27, 28, 29, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 mm or more, or any range therein). In certain preferred aspects, the laminate has a thickness of 0.3 to 10 mm, 0.3 to 5 mm, or 0.3 mm to 3 mm. In certain aspects, the flame retardant layer has a thickness of 0.05 mm to 0.8 mm. In certain aspects, the porous layer (e.g., aerogel layer) has a thickness of 0.05 mm to 1.0 mm (or any number or range thereof, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 mm), preferably 0.05 mm and 0.254 mm.

[0010] In some aspects, the flame retardant layer is not electrically insulating. In other aspects, the flame retardant layer is electrically insulating. In some aspects, the flame retardant layer and / or the entire laminate meets a plastic flammability standard. In some particular aspects, the plastic flammability standard is UL94 5VA or UL94 5VB. In certain aspects, the flame retardant layer includes fibers (e.g., woven and / or nonwoven fibers) and / or one or more of a metal hydroxide, an organic phosphate, an alumina hydroxide, an inorganic filler, and / or a metal oxide. In some aspects, the flame retardant layer can be halogen-free. In some aspects, the flame retardant layer can include a silicate (e.g., a phyllosilicate). In some particular aspects, the silicate can include mica. The flame retardant layer can include at least 90% by weight of a silicate, preferably mica, based on the total weight of the flame retardant layer. In some aspects, the flame retardant layer includes a ceramic. The ceramic can include inorganic and / or non-metallic materials (e.g., clay, kaolinate, aluminum oxide, silicon carbide, tungsten carbide, etc.) that can be exposed to high temperatures. In some aspects, the ceramic can include a metal oxide or a non-metal oxide, or a combination thereof. In some aspects, the ceramic can include alumina, beryllia, ceria, zirconia, carbides, borides, nitrides, or silicides, or any combination thereof. In some aspects, the flame retardant layer can include at least 90% by weight ceramic, based on the total weight of the flame retardant layer.

[0011] In some aspects, the porous layer is an aerogel layer. In some aspects, the aerogel layer comprises an organic polymer. In some aspects, the organic polymer is a thermoplastic polymer. In some aspects, the thermoplastic polymer is a polyimide, polystyrene, polyester, polyamide, polyether, polyurethane, acrylic polymer, polyurea, polypyrrole, polythiophene, polyaniline, acrylic polymer, vinyl polymer, polysiloxane, polysulfide, polycarbonate, or copolymer, or a mixture thereof. In a preferred embodiment, the thermoplastic polymer is a polyimide, polyamic amide, or a mixture or copolymer thereof. In certain aspects, the aerogel layer comprises at least 50%, 60%, 70%, 80%, 90%, or 95% thermoplastic polymer, preferably polyimide or polyamic amide. In other aspects, the polymeric aerogel layer comprises less than 50%, 40%, 30%, 20%, 10%, or 5% thermoplastic polymer, preferably polyimide or polyamic amide. In some aspects, the aerogel layer has a decomposition temperature of 400°C or higher, preferably 400°C to 600°C.

[0012] The laminate of the present invention may include one or more adhesive layers. The one or more adhesive layers may be bonded to the aerogel layer. In one aspect, the first adhesive layer is disposed between the flame retardant layer and the aerogel layer. The first adhesive layer may have a melting or decomposition temperature of greater than 500° C., preferably greater than 600° C. In another aspect, the second adhesive layer may be disposed on the rear surface of the aerogel layer (the surface further from the flame retardant layer). The first and / or second adhesive layers may be pressure-sensitive adhesive layers that can attach the rear surface of the aerogel layer to a substrate. A removable or peelable liner layer may be disposed on the second adhesive layer prior to use. In certain aspects, the second adhesive layer may have a melting or decomposition temperature of greater than 500° C., preferably greater than 600° C. In certain aspects, the adhesive layer may include a silicone adhesive compound and / or an epoxy compound.

[0013] The laminate of the present invention may include one or more heat spreading layers. In some aspects, the one or more heat spreading layers may have a thermal conductivity of at least 15 W / m·K, preferably from 15 W / m·K to 2,500 W / m·K. In some aspects, the one or more heat spreading layers may include a metal or graphite or a combination thereof. The metal or graphite may have a thermal conductivity of at least 15 W / m·K, preferably from 15 W / m·K to 2,500 W / m·K. In some aspects, the metal may include copper, aluminum, molybdenum, tungsten, rhenium, tantalum, niobium, stainless steel, nickel, or an alloy thereof. In some aspects, the one or more heat spreading layers can include at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99% or more metal and / or graphite by weight based on the total weight of the heat spreading layer. In some aspects, the one or more heat spreading layers can have a thickness of 0.001 mm to 0.4 mm, preferably 0.01 mm to 0.05 mm, or any range or number therein (e.g., 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, or 0.25 mm).

[0014] In some aspects, one or more heat distribution layers can be bonded to the flame retardant layer and / or the aerogel layer. In some aspects, one or more heat distribution layers can be disposed between the flame retardant layer and the aerogel layer. In some aspects, a first adhesive layer can be disposed between the flame retardant layer and the heat distribution layer, and / or a second adhesive layer can be disposed between the heat distribution layer and the aerogel layer. In some aspects, no adhesive layer is disposed between the flame retardant layer and the aerogel layer. In some aspects, the first adhesive layer can be in direct contact with the flame retardant layer and the heat distribution layer, and the second adhesive layer can be in direct contact with the heat distribution layer and the aerogel layer. In some aspects, a third adhesive layer, and optionally a liner layer, can be used, where the third adhesive layer is disposed between the aerogel layer and any liner layer. In some aspects, the third adhesive layer can be in direct contact with the aerogel layer and any liner layer. In some aspects, the first, second, and / or third adhesive layers each: (1) may have a melting or decomposition temperature greater than 500° C.; (2) may include a pressure-sensitive adhesive; and / or (3) may include a silicone adhesive compound and / or an epoxy compound. In some aspects, any one, any combination, or all of the flame retardant layer, the heat dissipation layer, the aerogel layer, and / or the first, second, and / or third adhesive layers may be perforated. In some aspects, the perforations may help to allow removal of any gas (e.g., due to evaporation or boiling of the adhesive layers) from the laminate.

[0015] The laminate of the present invention may include one or more reinforcing layers. In some aspects, the one or more reinforcing layers may be attached to at least a portion of the flame retardant layer and / or may be included in at least a portion of the volume of the flame retardant layer. In some aspects, the one or more reinforcing layers may include fibers. Non-limiting examples of fibers include glass fibers, carbon fibers, aramid fibers, thermoplastic fibers, thermoset fibers, ceramic fibers, basalt fibers, rock wool fibers, steel fibers, or cellulosic fibers, or any combination thereof. In some aspects, the fibers are non-woven or woven fibers.

[0016] In some aspects of the present invention, any one, any combination, or all of the flame retardant layer, the porous layer (e.g., the aerogel layer), the adhesive layer, the heat dissipation layer, and / or the reinforcement layer are perforated. The size and pattern of the perforations can be modified as desired. In some aspects, the size of the perforations is nanometers, micrometers, or millimeters. In some aspects, the pattern of the perforations can be random, lattice-like, circular, etc. In some particular embodiments, the pattern is a lattice-like. Without wishing to be bound by theory, it is believed that the perforations can be useful in the event that the adhesive layer off-gassing when exposed to high temperatures or reduced pressure. Allowing off-gassing can be useful to avoid foaming and / or peeling of the aerogel layer and / or the flame retardant layer.

[0017] Also disclosed in the context of the present invention is a device comprising one or more laminates of the present invention. The laminates can be coupled to the device such that the front face of a first one of the laminates is disposed further from the device than the rear face of the first laminate. The device can be any type of device. In a preferred aspect, the device is one that may be exposed to high temperatures (e.g., greater than 500°C) during use. One example is a battery. In a preferred aspect, the battery can be a battery system or battery pack of an electric vehicle. The battery can be a secondary / rechargeable battery (e.g., a lithium-ion battery or a nickel-metal hydride battery). The vehicle can include one or more wheels and one or more electric motors, each configured to rotate at least one of the wheels. The battery can be in electrical communication with at least one of the electric motors. In another example, the device can be a bus bar for the battery. The bus bar can be in electrical communication with the battery. The laminates of the present invention can be coupled to a bus bar such that the front face of the laminate is disposed further from the bus bar than the rear face of the laminate.

[0018] In some aspects, the device may be a compression pad, a battery cell, a battery module, a battery pack, or a battery box. The compression pad, which may also be referred to as a battery pad cushion, may be disposed between the battery cells to help resist dimensional changes of the cells during charging and / or use of the cells. The compression pad may allow sufficient pressure to be applied to the battery pack to maintain thermal and / or electrical connection, while also allowing the battery cells to tolerate and / or expand during charging or exposure to extreme temperatures. In some aspects, the compression pad may include a compressible material. In some aspects, the compressible material may be a foam (e.g., polyurethane foam or silicone foam). In some aspects, the compression pad is disposed between a first battery cell and a second battery cell. The laminate of the present invention may cover a portion, a majority, or all of the outer surface of the compression pad.

[0019] In some aspects, the device can be a battery cell. The battery cell can be charged to provide electrical energy (e.g., to power an electric motor) and can be discharged during use or when exposed to extreme temperatures or when in a latent state. A plurality of battery cells can be disposed side-by-side, with compression pads disposed between each battery cell. The laminate of the present invention can cover a portion, a majority, or all of the exterior surface of the battery cell.

[0020] In some aspects, the device can be a battery module. The battery module can include a plurality of battery cells. The laminate of the present invention can cover a portion, a majority, or all of an outer surface of the battery module.

[0021] In some aspects, the device can be a battery pack. The battery pack can include a plurality of battery modules. The laminate of the present invention can be disposed between the battery modules of the battery pack. The laminate of the present invention can cover a portion, a majority, or all of the exterior surface of the battery pack.

[0022] In some aspects, the device can be a battery box or battery casing or container. The battery box or container can enclose a portion, a majority, or all of the battery pack. The battery box can include an exterior surface, an interior surface, and an interior volume. The laminate of the present invention can cover at least a portion, a majority, or all of the exterior surface of the battery box, at least a portion, a majority, or all of the interior surface, or both. In some preferred aspects, at least a portion, a majority, or all of the interior surface of the battery box is covered with one or more laminates of the present invention. In some aspects, the interior volume of the battery box includes a compression pad, a battery cell, a battery module, or a battery pack, or any combination thereof. In some aspects, the compression pad, the battery cell, the battery module, the battery pack, and / or the battery box are included in a vehicle, and the vehicle includes one or more electric motors. In some aspects, the vehicle can be an automobile, an aircraft, a train, a ship, or a spacecraft.

[0023] In some aspects, the device can be a cable. The cable can have a length and a width. The length can be greater than the width. In some aspects, the cable can be electrically conductive. In some aspects, the cable can have an electrically conductive portion and an electrically insulating portion. In some aspects, the electrically insulating portion can include some, most, or all of the electrically conductive portion. In some aspects, the electrically conductive portion can include an electrically conductive metal (e.g., copper, gold, platinum, aluminum, steel, etc.). In some aspects, the cable can have a diameter of 0.0001 inches to 10 inches, preferably 0.001 inches to 1 inch, or any range or number therein (e.g., diameters 0.0001, 0.0002, 0.0003, 0.0004, 0.0005, 0.0006, 0.0007, 0.0008, 0.0009, 0.001, 0.002, The cable may include a length of 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 inches. In certain aspects, the cable may be included in a missile, rocket, artillery, manned aircraft, unmanned aerial vehicle, ground vehicle, or sea vehicle. In certain aspects, the vehicle may be a spacecraft or aircraft.

[0024] Also disclosed in the context of the present invention is a method of thermally protecting a device using any one of the laminates of the present invention. The method may include bonding the laminate to a surface of the device. The bonding may be via an adhesive. The laminate may be positioned relative to the device such that the front surface of the laminate is positioned further from the device than the rear surface of the laminate. The laminate of the present invention is capable of maintaining the temperature of the device at or below 500°C when the front surface of the laminate is exposed to a temperature of greater than 500°C, preferably between 500°C and 1,500°C (or 600, 700, 800, 900, 1,000, 1,200, 1,300, 1,400°C or any range therein), or more preferably between 700°C and 1,200°C (or 800, 900, 1,000, or 1,100°C or any range therein), for a period of between 1 minute and 90 minutes (or 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, or 90 minutes or any range therein), preferably for at least 5 minutes.

[0025] The term "aerogel" generally refers to a class of materials produced by forming a gel, removing a mobile interstitial solvent phase from the pores, and then replacing it with a gas or gas-like material. By controlling the gel and evaporation system, density, shrinkage, and pore collapse can be minimized. Aerogels of the invention can include macropores, mesopores, and / or micropores. In preferred aspects, a majority (e.g., greater than 50%) of the pore volume of the aerogel can be composed of macropores. In other alternative aspects, a majority of the pore volume of the aerogel can be composed of mesopores and / or micropores, such that less than 50% of the pore volume of the aerogel is composed of macropores. In some embodiments, aerogels of the invention have low bulk densities (about 0.75 g / cm 3 Less than about 0.01 g / cm 3 ~0.5g / cm 3 ), high surface area (typically about 10 m 2 / g~1,000m 2 / g or more, preferably about 50m 2 / g~1000m 2 / g), high porosity (greater than or equal to about 20%, preferably greater than about 85%), and / or relatively large pore volume (greater than or equal to about 0.3 mL / g, preferably greater than or equal to about 1.2 mL / g).

[0026] The presence of macropores, mesopores, and / or micropores in the aerogels of the present invention can be determined by mercury intrusion porosimetry (MIP) and / or gas physisorption experiments. MIP tests can be used to measure mesopores and macropores (i.e., American Standard Testing Method (ASTM) D4404-10, Standard Test Method for Determination of Pore Volume and Pore Volume Distribution of Soil and Rock by Mercury Intrusion Porosimetry). Gas physisorption experiments can be used to measure micropores (i.e., ASTM D1993-03 (2008) Standard Test Method for Precipitated Silica - Surface Area by Multipoint BET Nitrogen).

[0027] The "decomposition temperature" of a material is the temperature at which 2%, 5%, or 10% of a sample of the material will decompose when heated in an environment elevated to that temperature. The decomposition temperature can be measured by placing a sample in a thermogravimetric analyzer (TGA), heating the sample from ambient temperature in the TGA (e.g., at a rate of 10°C / min), and recording as the decomposition temperature the temperature at which the mass of the sample is 2%, 5%, or 10% lower than its initial mass.

[0028] The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically. Two items that are "coupled" may be integral to one another, or may be connected to one another through one or more intermediate components or elements.

[0029] The terms "a" and "an" are defined as one or more, unless this disclosure expressly requires otherwise.

[0030] The term "substantially" is defined as being largely, but not necessarily entirely, what is specified, as will be understood by those of skill in the art (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees, and substantially parallel includes parallel). In any disclosed embodiment, the terms "substantially," "approximately," and "about" may be substituted with "within [a percentage]" of what is specified, where the percentage is 0.1%, 1%, 5%, or 10%.

[0031] The term "and / or" means and, or, or. By way of example, A, B, and / or C includes: A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C. In other words, "and / or" operates as an inclusive or.

[0032] The terms "comprise" (and any form of including, such as "comprises" and "comprising"), "have" (and any form of including, such as "has" and "having"), "include" (and any form of including, such as "includes" and "including"), and "contain" (and any form of including, such as "contains" and "containing") are open-ended linking verbs. As a result, an apparatus that "comprises," "has," "includes," or "contains" one or more elements has those one or more elements, but is not limited to having only those one or more elements. Similarly, a method that "comprises," "has," "includes," or "contains" one or more steps has those one or more steps, but is not limited to having only those one or more steps.

[0033] The laminates of the present invention can "comprise," "consist essentially of," or "consist of" certain ingredients, components, compositions, etc. disclosed throughout this specification. With respect to the transitional phrase "consist essentially of," in one non-limiting aspect, a basic and novel feature of the laminates of the present invention is their ability to thermally protect a substrate over time when exposed to temperatures that could cause the substrate to fail (e.g., catch fire, explode, decompose, deform, etc.).

[0034] Unless expressly prohibited by the nature of this disclosure or the embodiments, features of one embodiment may be applied to other embodiments even if not described or illustrated.

[0035] Some details relating to the aforementioned aspects and others are set forth below. [Brief description of the drawings]

[0036] The following drawings are presented by way of example, and not by way of limitation. For purposes of brevity and clarity, not all features of a given structure are always shown in every figure in which the structure appears. Identical reference numbers do not necessarily refer to identical structures. Rather, the same reference numbers may be used to refer to similar features or features with similar functionality, as well as non-identical reference numbers.

[0037] [Figure 1] 1A-1B are cross-sectional views of embodiments of laminates of the present invention having a flame retardant layer and a single aerogel layer (FIG. 1A) or a flame retardant layer and two aerogel layers (FIG. 1B) attached to a substrate surface. [Diagram 2] FIG. 2 is a cross-sectional view of another embodiment of a laminate of the present invention having a liner layer removably disposed on an adhesive layer of the laminate, the liner layer defining at least a portion of the rear surface of the laminate. [Diagram 3] FIG. 2 is a cross-sectional view of another embodiment of a laminate of the present invention having a reinforcing layer attached to the flame retardant layer of the laminate. [Figure 4] FIG. 2 is a cross-sectional view of another embodiment of a laminate of the present invention having a heat spreading layer disposed between the flame retardant layer of the laminate and the aerogel layer of the laminate. [Diagram 5] FIG. 2 is a perspective view of a roll of an embodiment of a laminate of the present invention. [Figure 6] FIG. 1 is a schematic diagram of a vehicle having a battery including one or more embodiments of a laminate of the present invention. [Figure 7] Figure 7A is a schematic diagram of a cable including one or more embodiments of a laminate of the present invention, and Figure 7B is a cross-sectional schematic diagram of the cable of Figure 7A taken along line 7B-7B of Figure 7A. [Figure 8] FIG. 1 is a schematic diagram of a setup for testing the heat and flame properties of laminates of the present invention. [Figure 9] FIG. 9 is a schematic diagram of the laminate used in the test setup of FIG. 8. [Figure 10]Thermal profiles of a control (no barrier on copper substrate), a flame retardant barrier (layer) on copper substrate, an insulating layer on copper substrate, a laminate of the present invention on copper substrate (one insulating layer and one flame retardant layer), and another laminate of the present invention on copper substrate (two insulating layers and one flame retardant layer). [Figure 11] FIG. 2 is another schematic diagram of a setup for testing the heat and flame properties of laminates of the present invention. [Figure 12] 1 is a thermal profile of a laminate of the present invention bonded to a substrate compared to an unprotected substrate in several cases. [Figure 13] 1 is a thermal profile of a laminate of the present invention bonded to a substrate compared to an unprotected substrate in several cases. [Figure 14] 1 is a thermal profile of a laminate of the present invention bonded to a substrate compared to an unprotected substrate in several cases. [Figure 15] 1 is a thermal profile of a laminate of the present invention bonded to a substrate compared to an unprotected substrate in several cases. [Figure 16] FIG. 2 is a rear view of a carbon fiber composite plate protected on the front side by one of the laminates of the present invention while exposed to a 1,000° C. flame for 25 minutes. [Figure 17] 1 is a thermal profile of one of the laminates of the present invention bonded to an aluminum sheet substrate. [Figure 18] FIG. 2 is a view of the back side of an aluminum sheet substrate protected on the front side by one of the laminates of the present invention while exposed to a 1000° C. flame for 25 minutes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Detailed Description The electrification of modern society offers technological advances that offer alternatives to combustion engines. However, with these advances come new challenges. As one example, the use of battery systems in electric vehicles in the transportation industry can reduce reliance on gasoline as a fuel. However, these battery systems can lead to significant risks of explosion, fire, and / or toxic gas emissions, for example, if the battery system is exposed to excessive heat (e.g., above 500°C).

[0039] The present invention provides a solution to at least one of these problems. The solution is a laminate material that can provide both good thermal protection and flexibility, both of which are desirable attributes to have in certain applications (e.g., battery systems for electric vehicles). In one aspect, the present invention provides a laminate including a flame retardant layer having a flammability rating in accordance with at least one plastic flammability standard (e.g., UL94 5VB or UL94 5VA rating) and an aerogel layer. The laminate of the present invention, when attached to a surface of a substrate, can maintain the temperature of the substrate (e.g., the surface temperature of the substrate) at or below 500°C when the laminate is exposed to a temperature of more than 500°C, preferably 500°C to 1,500°C, or more preferably 700°C to 1,200°C, for 1 minute to 90 minutes, preferably at least 5 minutes. The laminates of the invention are also thin (e.g., having a thickness of 25.4 millimeters (mm), 20 mm, 15 mm, 10 mm, 5 mm, 3 mm, 2 mm, 1 mm, 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, 0.1 mm or less, or any range therein) and flexible (e.g., capable of being rolled (see, e.g., FIG. 5) and / or having a bend radius). The good thermal protection properties of the laminates of the invention, along with their thin and flexible characteristics, enable the laminates to be used in locations with severe space constraints, such as covers or protective layers for batteries (e.g., electric vehicle batteries and battery systems having multiple batteries), battery bus bars, and a wide range of other articles of manufacture.

[0040] A. Thermal and Flame Barrier Protection Laminates 1A and 1B, a laminate 100 is shown. The laminate 100 can be attached to a surface of a substrate 10, the laminate having opposing front and rear faces 12 and 14. The laminate 100 can include one or more insulating porous layers (e.g., aerogel layers) 16, a flame retardant layer 18 defining at least a portion (e.g., at least a majority, up to and including all) of the front face 12, and one or more adhesive layers 20, 22, and 24. The insulating layers (e.g., aerogel layers) can also include any one or more of 1, 2, 3, 4, 5, 6, 7, 8, or 9 insulating layers, or between any two of them. The adhesive layers 20, 22, and 24 can be the same or different materials (e.g., silicone adhesive compounds, acrylic adhesive compounds, rubber adhesive compounds, phenolic compounds, cyanate ester compounds, epoxy resin compounds, etc.). In certain aspects, the adhesive layer can be an adhesive that can maintain adhesion at high temperatures (e.g., 500° C. or higher), non-limiting examples of which include FLEXcon Silicone Adhesive SA 6000 SA 9000D series (FLEXcon Company, Inc., Spencer, Massachusetts), Alamo Tapes Epoxy Adhesives (Alamotape, San Antonio, Texas), Avery FT 3010 (Avery Dennison Corporation, Painesville, Ohio), and Adhesive Applications S1001-01 (Adhesive Applications, Inc., Easthasmpton, Massachusetts). The number of adhesive layers 20, 22, and 24 can be any one or more of, or between any two of, 1, 2, 3, 4, 5, 6, 7, 8, or 9, depending on, for example, the number of insulation layers. The second adhesive layer 22 can define at least a portion (e.g., at least a majority, up to all) of the rear surface 14 such that the second adhesive layer can adhere the laminate 100 to the surface 14 when placed on the surface 14. The third adhesive layer 24 can adhere the insulation layers 16 together.As shown, the laminate 100 includes one (FIG. 1A) or two (FIG. 1B) insulation layers 16, a flame retardant layer 18, and adhesive layers 20, 22, 24, with substantially all of the front surface 12 defined by the flame retardant layer and substantially all of the rear surface 14 defined by the second adhesive layer. Furthermore, in some embodiments, the laminate 100 need not have the first adhesive layer 20 and / or the second adhesive layer 22. In one embodiment, the laminate 100 can include a single insulation layer (aerogel layer) 16, a flame retardant layer 18, an adhesive layer 20, and an adhesive layer 22.

[0041] The combination of the thermal insulation layer 16 and the flame retardant layer 18 can mitigate heat and flame propagation for heat and flame protection of the substrate surface 10. For example, the flame retardant layer 18 can include flame retardant materials, optionally with nonwoven fibers, paper, and fillers. Flame retardant materials include metal hydroxides, organic phosphates, metal phosphates, nitrogen-containing polymers, nitrogen-phosphorus compounds, talc, sulfonates or salts thereof, silica, silicates (e.g., mica), hydrated oxides, organic polymers, nanoclays, organoclays, organic polymers, silicon-phosphorus-nitrogen compounds, metal oxides, ceramics (e.g., metal and / or non-metal oxides, alumina, beryllia, ceria, zirconia, carbides, borides, nitrides, and / or silicides), and mixtures thereof. Non-limiting examples of metal hydroxides include alumina trihydrate, magnesium oxide, and the like. Non-limiting examples of metal oxides include titanium oxide, aluminum oxide, zinc oxide, iron oxide, magnesium oxide, calcium oxide, and the like. Non-limiting examples of phosphates include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tributoxyethyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl phosphate, trixylenyl phosphate, tris(2-phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, resorcinol bis(diphenyl phosphate), resorcinol bis(dixylenyl phosphate), resorcinol bis(dicresyl phosphate), hydroquinone bis(dixylenyl phosphate), biphenyl phosphate, and bis(diphenyl phosphate). These include sphenol A bis(diphenyl phosphate), tetrakis(2,6-dimethylphenyl) 1,3-phenylene bisphosphate, pentaerythritol phosphate alcohol, oligomeric ethyl ethylene phosphate, tricresyl phosphate, trixylenyl phosphate, isopropyl phenyl phosphate, tert-butylphenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, butyl diphenyl phosphate, dibutyl phenyl phosphate, tributyl phosphate, tetraphenyl resorcinol diphosphate, and tetraphenyl bisphenol-A diphosphate.In some embodiments, the flame retardant layer (eg, 18) can comprise at least 90% by weight of a flame retardant material, such as at least 90% by weight of a silicate, or at least 90% by weight of a ceramic.

[0042] Non-limiting examples of fillers include kaolin clay, talc, mica, calcium carbonate, alumina trihydrate, montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, vermiculite, laponite, rectorite, perlite, aluminum nitride, silicon carbide, boron nitride, and combinations thereof.

[0043] The flame retardant layer can be reinforced. For example, the flame retardant layer can include woven and / or nonwoven fibers. Non-limiting examples of fibers include aramid fibers, organic fibers, glass fibers, carbon fibers, thermoplastic fibers, thermosetting fibers, basalt fibers, ceramic fibers, rock wool fibers, steel fibers, cellulosic fibers, and the like. In embodiments where the flame retardant layer is fiber-reinforced, the fibers can be included in at least a portion of the volume of the flame retardant layer, for example, in the form of a reinforcing layer.

[0044] Additionally or alternatively, and referring to Figure 3, some laminates, such as laminate 300, include a reinforcing layer 60 separate from the flame retardant layer 18, which may include woven and / or nonwoven fibers, as discussed above. In particular, the reinforcing layer 60 may be attached to at least a portion of the flame retardant layer 18, such as via an adhesive layer 20. Other laminates may include any suitable number of reinforcing layers (e.g., 60), each of which may be positioned in any suitable location within the laminate.

[0045] The flame retardant layer 18 may be electrically insulating or non-electrically insulating and may meet plastic flammability standards (e.g., UL94 V-0, V-1, V-2, HB, 5VA, 5VB, etc.). The thickness of the flame retardant layer may range from 0.05 mm to 1.0 mm, or 0.1 mm to 0.6 mm, 0.2 mm to 0.5 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, or 0.5 mm, or any range or value therebetween. In one case, the thickness of the flame retardant layer ranges from 0.145 mm to 0.225 mm and has a flammability rating of UL94 5VA or UL94 5VB, preferably UL94 5VA. The flame retardant layer 18 may be a commercially available product that can be bonded to the insulation layer 16. The flame retardant layer may include an adhesive layer (e.g., a pressure-sensitive adhesive) to facilitate bonding of the two layers. Non-limiting examples of commercially available flame retardant tapes or papers are those sold under the Unifrax brand (e.g., FyreWrap LiB Papers and Films), 3M® brand (e.g., 3M VHB Tape, 3M FRB Paper), Scotch® brand, U-Line brand, etc. In some specific embodiments, Unifrax brand FyreWrap LiB Paper (e.g., FX70 and IN70), Unifrax brand FyreWrap LiB Film (e.g., C1554), 3M® Flame Barrier FRB-WT series, 3M® Flame Barrier FRB-NT series (e.g., FRB-BK, FRB-NT Laminate, FRB-NC Laminate, or FRB-NC series) (3M, St. Paul, Minnesotas) can be used.

[0046] Each of the insulating layers 16 may have a thermal conductivity of less than or equal to any one of 0.05, 0.045, 0.040, 0.035, 0.030, 0.025, 0.020, 0.015, or 0.010 Watts per meter Kelvin (W / m K), or between any two (e.g., less than or equal to 0.025 W / m K), and / or a thermal conductivity of less than or equal to 0.30, 0.20, 0.15, 0.125, 0.10, 0.09, 0.08, 0.07, 0.06, or 0.05 millimeters per second (mm 2 / s) or between any two (for example, 0.15 mm 2 / s or less or 0.10 mm 2 / s or less). As used herein, thermal conductivity and thermal diffusivity are each measured at 25° C. In addition, each of the insulating layers 16 may be heat resistant and / or have a low coefficient of thermal expansion so that the laminate 100 can withstand heating during use and expansion in applications where the laminate is subject to severe space constraints. For example, each of the insulating layers 16 may have a decomposition temperature of any one or more of, or between any two of, 400, 425, 450, 475, 500, 525, 550, 575, or 600° C. (e.g., 450° C. or more), and / or a coefficient of thermal expansion (e.g., in at least one direction) of any one or less of, or between any two of, 40, 35, 30, 25, 20, 15, 10, or 5 μm / m·K (e.g., 35 μm / m·K or less).

[0047] To achieve such properties, at least one (up to and including each) of the insulating layers 16 may include a layer of polymeric aerogel. The amount of polymeric aerogel may be at least 90% by weight of an organic polymer, such as polyimide, polyaramid, polyurethane, polyurea, and / or polyester (e.g., polyimide). Each polymeric aerogel layer may have micropores, mesopores, and / or macropores. Any one or more of 10%, 25%, 50%, 75%, or 95% of the pore volume of each aerogel layer, or between any two, may be composed of micropores, mesopores, and / or macropores (e.g., micropores, mesopores, micropores and mesopores, or macropores). The mean pore size and / or median pore size of each aerogel layer can be any one or more of 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 800, 1,000, 2,000, 3,000, 4,000, or 5,000 nm, or between any two (e.g., the mean pore size can be 100-500 nm and the median pore size can be 250-600 nm). The materials and fabrication process for the layers of polymeric aerogel are described in further detail below.

[0048] In some embodiments, for at least one (e.g., each) of the insulation layers 16, the aerogel layer can include reinforcing fibers, which can be dispersed throughout the aerogel layer (e.g., as aligned (e.g., woven) fibers or chopped fibers or discontinuous fibers that are not arranged in a sheet) or embedded in the aerogel layer (e.g., as a woven, nonwoven, or unidirectional sheet of fibers), optionally such that the volume of the fibers is any one or more of 0.1%, 10%, 20%, 30%, 40%, or 50% of the volume of the aerogel layer, or between any two. However, the aerogel layer need not include fibers (e.g., to promote flexibility).

[0049] Suitable fibers include glass fibers, carbon fibers, aramid fibers, thermoplastic fibers, thermoset fibers, ceramic fibers, basalt fibers, rock wool fibers, steel fibers, cellulose fibers, etc. The fibers used for reinforcement have an average filament cross-sectional area of ​​7, 15, 30, 60, 100, 200, 300, 400, 500, 600, 700, or 800 μm. 2 or between any two of; for example, for fibers having a circular cross-section, the average diameter of the fibers can be any one or more of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 μm, or between any two (e.g., 5-24 μm, such as 10-20 μm or 12-15 μm).

[0050] Non-limiting examples of thermoplastic polymers that may be used for the polymeric reinforcing fibers include polyethylene terephthalate (PET), polycarbonate (PC), polybutylene terephthalate (PBT), poly(1,4-cyclohexylidenecyclohexane-1,4-dicarboxylate) (PCCD), glycol modified polycyclohexyl terephthalate (PCTG), poly(phenylene oxide) (PPO), polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polymethyl methacrylate (PMMA), polyethyleneimine or polyetherimide (PEI), and and derivatives thereof, thermoplastic elastomers (TPE), terephthalic acid (TPA) elastomers, poly(cyclohexanedimethylene terephthalate) (PCT), polyethylene naphthalate (PEN), polyamide (PA), polysulfone sulfonate (PSS), sulfonate of polysulfone, polyether ether ketone (PEEK), polyether ketone (PEKK), acrylonitrile butyldiene styrene (ABS), polyphenylene sulfide (PPS), copolymers thereof, polyesters or derivatives thereof, polyamides or derivatives thereof (e.g., nylon), or mixtures thereof.

[0051] Non-limiting examples of thermoplastic polymers that may be used as materials for the polymeric reinforcing fibers include unsaturated polyester resins, polyurethanes, polyoxybenzyl methylene glycol anhydrides (e.g., Bakelite), urea formaldehyde, diallyl phthalate, epoxy resins, epoxy vinyl esters, polyimides, cyanate esters of polycyanurates, dicyclopentadiene, phenols, benzoxazines, copolymers thereof, or mixtures thereof.

[0052] Each of the insulation layers 16 may include a layer of polymeric aerogel, although in other embodiments, at least one (up to and including each) of the insulation layers may be any suitable insulating material, such as a layer of fiber. At least one (up to and including each) of the insulation layers 16 may also include a layer of fiber laminated to the layer of polymeric aerogel, optionally such that the layer of fiber is disposed closer to the front surface 12 of the laminate 100 than the layer of aerogel. The fibers of the fiber layer may be any of those previously described for the aerogel fiber reinforcement (e.g., glass fiber and / or basalt fiber) and may be arranged in a variety of fibrous structures. For example, the fibers may form a fiber matrix, such as a felt, batting lofty batting, mat, woven fabric, or nonwoven fabric. The fibers may be oriented in one direction or in all directions.

[0053] In some embodiments, the fibers used as reinforcement in the aerogel layer or fiber layer are 5 μm or less. 2 ~40,000μm 2 and / or an average length of 20 mm to 100 mm.

[0054] To enable use of the laminate 100 in applications having tight space constraints, each of the insulating layers 16 (e.g., aerogel layers) can be relatively thin. For example, the thickness 26 (FIG. 1A) of at least one (e.g., each) of the insulating layers 16 can be equal to or less than any one of 50, 25, 20, 15, 10, 5, 4, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.15, 0.1, or 0.05 mm, or between any two (e.g., 0.10-0.20 mm, such as 0.165 mm).

[0055] When the laminate 100 includes multiple insulation layers 16 and / or flame retardant layers 18, the laminate may include multiple adhesive layers (e.g., adhesive layers 20, 22, and 24), with the second adhesive layer 22 defining at least a portion of the second surface 14 to allow for adhesion to the surface 10 (e.g., a substrate) as described above. The remaining adhesive layers (e.g., adhesive layer 24) may bond the insulation layer 16, the flame retardant layer 18, or a combination of insulation and flame retardant layers. To do so, each of the adhesive layers may be disposed between and in contact with adjacent ones of the other laminate layers (e.g., between two of the insulation layers 16 and / or between one of the insulation layers and a flame retardant layer). As an example, two insulation layers may be bonded together and bonded to a flame retardant layer. In another example, a stack of a first flame retardant layer (e.g., 18), a first insulation layer (e.g., 16), a second flame retardant layer, and a second insulation layer may be bonded together with adhesive layers. 1B, adhesive layer 20 is disposed between and in contact with flame retardant layer 18 and one of the insulation layers 16, and adhesive layer 24 is disposed between and in contact with two of the insulation layers. To promote adhesion without adding substantial thickness to laminate 100, the thickness 34 of at least one (e.g., each) of the adhesive layers (e.g., adhesive layers 20, 22, and 24) can be less than or equal to any one of 5.0, 4.5, 4.0, 3.5, 3.0, 2.5, 2.0, 1.5, or 1.0 mm, or between any two (e.g., between 1.5 and 3.5 mm).

[0056] At least one, including up to each of the adhesive layers, may include a pressure-sensitive adhesive, such as those including silicone, epoxy, acrylic, phenolic, cyanate ester, epoxy resin, and / or rubber. Such pressure-sensitive adhesives, when used for the second adhesive layer 22, may allow the laminate 100 to be quickly applied to the surface 10 (e.g., by simply pressing the laminate 100 against the surface) for its thermal protection. However, at least one of the adhesive layers may include a different type of adhesive, such as a fluoropolymer film, a polyimide film, and a B-stage epoxy; examples include commercially available adhesives such as FEP Film, Pyralux® HT, and Pyralux® GPL from DuPont™, and TSU510S-A from Toyochem Co., LTD. (Tokyo, Japan). With such other adhesives, adhesion can be achieved by stacking the layers of laminate 100 (e.g., 16 and 24, optionally flame retardant layer 18) and optionally applying heat and / or pressure to the stack (e.g., with a press) such that the temperature exceeds the glass transition temperature of the adhesive layers. In some embodiments having multiple adhesive layers, some of the adhesive layers (e.g., the second adhesive layer) can include a pressure sensitive adhesive and others (e.g., other than the second adhesive layer) can include another type of adhesive such as those listed above.

[0057] The composition of adhesive layers 20, 22, or 24 may mitigate the risk of delamination, such as by heat resistance. For example, at least one of adhesive layers 20, 22, and 24 (e.g., each) may have a melting or decomposition temperature of any one or more of, or between any two of, 350, 375, 400, 425, 450, 500, 550, or 600° C. In addition, at least one of adhesive layers 20, 22, and 24 (e.g., each) may have a glass transition or melting temperature of any one or more of, or between any two of, 100, 150, 175, 200, 225, 250, or 275° C.

[0058] The foregoing configuration allows the laminate 100 to provide heat and flame protection in high temperature and flammable environments. For example, the thermal diffusivity of the laminate 100 may be 0.15, 0.125, 0.10, 0.09, 0.08, 0.07, 0.06, 0.05, or 0.04 mm 2 / s, or between any two (for example, 0.10 mm 2 / s or less, for example, 0.075 mm 2 / s or less), thereby reducing the propagation of heat therethrough. The flammability rating of the laminate 100 may meet the requirements of UL 94. For example, the laminate may be capable of inhibiting the spread of flame at temperatures in excess of 500° C. for at least five minutes so as to resist combustion. The laminate may have a UL94 5VB or UL94 5VA rating.

[0059] Additionally, while the total thickness of the laminate 100 (shown as 30 in FIGS. 1A and 1B) can be 25.4 mm or less, the laminate can advantageously be relatively thin as previously discussed, e.g., 25.4, 20, 15, 10, 5, 4, 3, or 2 mm or less, or between any two (e.g., 10 mm or less or 0.3 mm or less). Such thinness can enable the laminate 100 to be used in small spaces, such as those common in vehicles such as electric or hybrid vehicles and / or electronic components, while still providing the aforementioned heat and flame protection. Thus, the laminate 100 can provide better heat and flame protection in size-constrained applications than traditional insulating / flame retardant materials that may not fit the size constraints or may sacrifice heat or flame protection to fit the size constraints.

[0060] 2, shown is a second laminate 200 substantially similar to laminate 100, with the primary exception that laminate 200 includes a liner layer 32. As shown, laminate 200 has not yet been attached to substrate surface 10. To protect second adhesive layer 22 prior to attachment to substrate surface 10 (e.g., against contaminants that may impair its adhesive properties), liner layer 32 may be removably disposed on second adhesive layer 22 such that at least a portion (e.g., at least a majority, including up to all) of rear surface 14 of laminate 200 is defined by the liner layer. Liner layer 32 may include, for example, a polymeric film or a paper sheet, and may be removed from second adhesive layer 22, for example, by peeling it from laminate 200.

[0061] Referring to FIG. 4, shown is a laminate 400 substantially similar to laminate 100, with the primary exception that laminate 400 includes a heat spreading layer 62. Laminate 400 includes one heat spreading layer 62 disposed between flame retardant layer 18 and aerogel layer 16. Nonetheless, other laminates of the present invention may include any suitable number of heat spreading layers (e.g., 62), which may be disposed in any suitable location within the laminate. Additionally, in laminate 400, heat spreading layer 62 is attached to both flame retardant layer 18 and aerogel layer 16 via adhesive layers 20 and 22, respectively, although no adhesive layer is required. Also, as with any laminate of the present invention, laminate 400 may include an adhesive layer 24 for adhering the laminate to a substrate, which may optionally be protected by a liner layer (e.g., 32) prior to adhering as described above.

[0062] The heat spreading layer 62 may include a thermally conductive material, such as a metal (e.g., copper, aluminum, molybdenum, tungsten, rhenium, tantalum, niobium, stainless steel, nickel, or alloys thereof), graphite, etc. In particular, the heat spreading layer 62 may include at least 90% by weight of a thermally conductive material, such as at least 90% by weight of metal, or at least 90% by weight of graphite. The heat spreading layer 60 may have a thermal conductivity of at least 15 W / m·K, preferably between 15 W / m·K and 2,500 W / m·K. Also, they may have a melting point or decomposition temperature of at least 500° C., preferably a melting temperature of at least 1,300° C., at least 1,600° C., at least 1,900° C., at least 2,200° C., at least 2,400° C., at least 2,700° C., at least 3,000° C., or at least 3,300° C. (e.g., and less than 3,800° C. or less than 3,600° C.). Generally, such heat spreading layers can diffuse heat from the environment along the laminate, thereby reducing the occurrence of hot spots along the lower layers of the laminate, and the associated burning or charring of the lower layers. The thickness 64 of the heat spreading layer 62 can be greater than any one of, or between any two of (e.g., 0.001 mm to 4 mm or 0.01 mm to 0.05 mm) the following: 0.001, 0.002, 0.004, 0.006, 0.008, 0.01, 0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, and 0.40 mm.

[0063] Referring now to FIG. 5, the laminate (e.g., 100, 200, 300, or 400) can be flexible. Illustratively, such a laminate can be placed in a roll 34 having an inside diameter 36 of less than or equal to any one of, or between any two of, 10 cm, 8 cm, 5 cm, 4 cm, 2 cm, 1 cm, 8 mm, 5 mm, 4 mm, 2 mm, or 1 mm without undergoing permanent deformation. Such flexibility can be provided by the materials of the insulation layer, the flame retardant adhesive layer, and other (if present) layers of the laminate and / or the relatively small thicknesses of those layers (e.g., as described above), even if not to the level of this example. When in the roll 34, a portion of the front surface 12 of the laminate can face a portion of its rear surface 14.

[0064] In some embodiments, the laminate may protect a device or substrate from temperatures exceeding 500°C. For example, the laminate 100-400 may be positioned relative to the device such that the front surface having the flame retardant layer is positioned farther from the device than the rear surface (e.g., rear surface 14) of the laminate. When exposed to temperatures of greater than 500°C to 1,500°C for 1 to 90 minutes (preferably at least 5 minutes), the temperature of the device does not exceed 500°C during that period. The exposure temperature may be in the range of 500°C to 1500°C or 700°C to 1200°C, or 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, 1500°C, or any range or value therebetween. Of course, the laminates of the present invention are also suitable for use in applications involving exposure to lower temperatures (e.g., up to 100°C, 200°C, 300°C, or 400°C) and / or for shorter periods of time (e.g., up to 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 40, 50, or 60 seconds) of any of the aforementioned temperatures.

[0065] Devices in which such thermal protection is advantageous include, for example, batteries (e.g., lithium ion batteries), bus bars, and electric or hybrid vehicles or electrical components, including batteries and electric motors, that are particularly exposed to high temperature environments. The surface 10 to which the laminate 100 is attached can be the surface of a battery, such as a lithium ion battery. The surface 10 can also be a bus bar or a non-conductive material.

[0066] For example, referring to FIG. 6 , shown is a battery 66 including battery cells 68. The cells 68 can be grouped into battery modules 70, and the modules can be assembled into a battery pack 72. The battery 66 can further include a battery housing or box 74. To isolate the cells 68, modules 70, and / or packs 72 from vibrations and / or to account for expansion / contraction of the cells, modules, and / or packs, the battery 66 can also include one or more compression pads 76, which can be disposed between the cells, between the modules, between the pack and the box 74, etc. The compression pads 76 can include, for example, a compressible material such as foam. The battery 66 can be included in a vehicle 78, such as the automobile shown. The vehicle 78 can otherwise be, for example, an automotive vehicle (e.g., an internal combustion engine vehicle, an electric vehicle, a hybrid electric vehicle), an aircraft (e.g., an airplane, a jet aircraft, a helicopter, an unmanned aerial vehicle, or an electric vertical take-off and landing (eVTOL) aircraft), a train, a motorcycle, a watercraft, a spacecraft, etc.

[0067] However, such batteries 66 are susceptible to thermal runaway events and / or exposure to other high temperature environments. To protect the battery 66, the vehicle 78 in which the battery is located, and / or the vehicle's occupants, one or more laminates of the present invention may be implemented. Illustratively, one of the laminates of the present invention may be disposed on an interior and / or exterior surface of at least one of the cells 68, modules 70, packs 72, compression pads 76, and / or boxes 74.

[0068] As another example, referring to Figures 7A and 7B, shown is a cable 80. The cable 80 may have a length 82 and a width or diameter 84, where the length is greater than the width (e.g., the length is 10 times or more the width). In particular, the diameter 84 may be 0.0003 inches to 10 inches, preferably 0.001 inches to 1 inch. The cable 80 may, but need not be, electrically conductive. The cable may be included in a vehicle (e.g., as described above), a missile, a rocket, a cannon, a manned aircraft, an unmanned aircraft, a ground vehicle, a sea vehicle, or a spacecraft. Such cables may be exposed to high temperatures, which the laminates of the invention may be used to mitigate. For example, the cable 80 may include one or more of the laminates of the invention (e.g., shown as 100 in Figure 7B) forming at least a portion of the exterior surface of the cable.

[0069] Non-limiting examples of articles of manufacture that may include the laminates of the present invention, in addition to those mentioned above, include vehicles, trucks, trailers, trains, rail cars, aircraft, spacecraft, body panels or parts for any of the above, bridges, pipelines, pipes, piping, boats, ships, storage vessels, storage tanks, furniture, windows, doors, handrails, functional or decorative building parts, pipe railings, electrical components, conduits, beverage containers, food containers, foils, batteries (e.g., electric vehicle batteries, battery systems, battery casings), and battery bus bars.

[0070] B. Polymer aerogel layer material The layers of the polymer aerogel can include organic materials, inorganic materials, or mixtures thereof. Organic aerogels can be made from polyacrylates, polystyrenes, polyacrylonitriles, polyurethanes, polyureas, polyimides, polyamides, polyaramids, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehyde, resorcinol formaldehyde, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, agarose, and the like. In certain embodiments, the aerogel is a polyimide aerogel.

[0071] Polyimides are a type of polymer that have many desirable properties. Polyimide polymers contain nitrogen atoms in the polymer backbone, where the nitrogen atoms are linked to two carbonyl carbons, somewhat stabilized by adjacent carbonyl groups. The carbonyl group contains a carbon, called the carbonyl carbon, which is double-bonded to an oxygen atom. Polyimides are usually thought of as AA-BB type polymers, since two different classes of monomers are usually used to produce polyimide polymers. Polyimides can also be prepared from AB type monomers. For example, aminodicarboxylic acid monomers can be polymerized to form AB type polyimides. Monoamines and / or monoanhydrides can be used as end-capping agents, if desired.

[0072] One class of polyimide monomers is usually diamines, or diamine monomers. It should be understood that diamine monomers can also be diisocyanates, and isocyanates can be substituted for amines in this description, where appropriate. As known to those skilled in the art, there are other types of monomers that can be used in place of diamine monomers. The other types of monomers are called acid monomers, and are usually in the form of dianhydrides. In this description, the term "diacid monomers" is defined to include dianhydrides, tetraesters, diester acids, tetracarboxylic acids, or trimethylsilyl esters, all of which can be reacted with diamines to produce polyimide polymers. Dianhydrides should be understood to be tetraesters, diester acids, tetracarboxylic acids, or trimethylsilyl esters, which can be substituted where appropriate. As known to those skilled in the art, there are other types of monomers that can be used in place of diacid monomers.

[0073] Since one diacid monomer has two anhydride groups, a different diamino monomer can react with each anhydride group, and thus the diacid monomer can be located between two different diamino monomers. The diamine monomer contains two amine functional groups; therefore, after the first amine functional group is linked to one diacid monomer, the second amine functional group is still available to link to another diacid monomer, which then links to another diamine monomer, and so on. In this way, the polymer backbone is formed. The resulting polycondensation reaction product forms a polyamic acid.

[0074] Polyimide polymers are usually formed from two different types of monomers, and different variants of each type of monomer can be mixed. Thus, one, two, or more diacid monomers can be included in the reaction vessel, as can one, two, or more diamino monomers. If long polymer chains are desired, the total molar amount of diacid monomers is kept approximately the same as the total molar amount of diamino monomers. Since multiple types of diamines or diacids can be used, the various monomer constituents of each polymer chain can be varied to produce polyimides with different properties. For example, a single diamine monomer AA can be reacted with two diacid comonomers B1B1 and B2B2 to produce polyimides of the general formula (AA-B1B1): x -(AA-B2B2) y where x and y are determined by the relative incorporation of B1B1 and B2B2 into the polymer backbone. Alternatively, diamine comonomers A1A1 and A2A2 can be reacted with a single diacid monomer BB to form a polymer chain of the general formula (A1A1-BB): x -(A2A2-BB) y In addition, two diamine comonomers A1A1 and A2A2 can be reacted with two diacid comonomers B1B1 and B2B2 to form a polymer chain of the general formula (A1A1-B1B1): w -(A1A1-B2B2) x -(A2A2-B1B1) y -(A2A2-B2B2) z where w, x, y, and z are determined by the relative incorporation of A1A1-B1B1, A1A1-B2B2, A2A2-B1B1, and A2A2-B2B2 into the polymer backbone. More than two diacid comonomers and / or more than two diamine comonomers can also be used. Thus, one or more diamine monomers can be polymerized with one or more diacids, and the general formula of the polymer is determined by varying the amount and type of monomers used.

[0075] There are many examples of monomers that can be used to make polymeric aerogels, including polyamic acid amide polymers. In some embodiments, the diamine monomer is a substituted or unsubstituted aromatic diamine, a substituted or unsubstituted alkyl diamine, or a diamine that can contain both aromatic and alkyl functional groups. A non-limiting list of possible diamine monomers includes 4,4'-oxydianiline (ODA), 3,4'-oxydianiline, 3,3'-oxydianiline, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, diaminobenzanilide, 3,5-diaminobenzoic acid, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 1,3-bis-(4-aminophenoxy)benzene, 1,3-bis-(3-aminophenoxy)benzene, 1,4-bis-(4-aminophenoxy)benzene, 1,4-bis-(3-aminophenoxy)benzene, 2,2-bis[4-( 4-aminophenoxy)phenyl]-hexafluoropropane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 4,4'-isopropylidenedianiline, 1-(4-aminophenoxy)-3-(3-aminophenoxy)benzene, 1-(4-aminophenoxy)-4-(3-aminophenoxy)benzene, bis-[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]sulfone, bis(4-[4-aminophenoxy]phenyl)ether, 2,2'-bis-(4-aminophenyl)-hexafluoropropane (6F-diamine), 2,2'-bis-(4-phenoxyaniline)isopropylidene, meta-phenylenediamine, para-phenylenediamine, 1,2-diaminobenzene, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,6-diaminopyridine, bis(3-aminophenyl)diethylsilane, 4,4'-diaminodiphenyldiethylsilane, benzidine, dichlorobenzidine, 3,3'-dimethoxybenzidine, 4,4'-Diaminobenzophenone, N,N-bis(4-aminophenyl)-n-butylamine, N,N-bis(4-aminophenyl)methylamine, 1,5-diaminonaphthalene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4-aminophenyl-3-aminobenzoate, N,N-bis(4-aminophenyl)aniline, bis(p-beta-amino-t-butylphenyl)ether, p-bis-2-(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,3-bis(4-aminophenoxy)benzene, m-xylenediamine, p-xylenediamine, 4,4'-diaminodiphenyl ether phosphine oxide, 4,4'-diaminodiphenyl N-methylamine, 4,4'- Diaminodiphenyl N-phenylamine, amino-terminated polydimethylsiloxane, amino-terminated polypropylene oxide, amino-terminated polybutylene oxide, 4,4'-methylenebis(2-methylcyclohexylamine), 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, and 4,4'-methylenebisbenzenamine, 2,2'-dimethylbenzidine, (also known as 4,4'-diamino-2,2'-dimethylbiphenyl (DMB)), bisaniline-p-xylidene, 4,4'-bis(4-aminophenoxy)biphenyl, 3,3'-bis(4 In certain embodiments, the diamine monomer is ODA, 2,2'-dimethylbenzidine, or both.

[0076] A non-limiting list of possible dianhydride ("diacid") monomers includes hydroquinone dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride), 2,2-bis(3,4-diphenylsulfonyl)dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride), ... dicarboxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, bis(3,4-dicarboxyphenyl)sulfoxide dianhydride, polysiloxane-containing dianhydrides, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-benzophenonetetraearboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylie(c arboxylie) dianhydride, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane, 2,6-dichloro Include naphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, phenanthrene, 8,9,10-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride and thiophene-2,3,4,5-tetracarboxylic dianhydride.In certain embodiments, the dianhydride monomer is BPDA, PMDA or both.

[0077] In some aspects, the molar ratio of anhydride to total diamine is 0.4:1 to 1.6:1, 0.5:1 to 1.5:1, 0.6:1 to 1.4:1, 0.7:1 to 1.3:1, or especially 0.8:1 to 1.2:1. In further aspects, the molar ratio of dianhydride to polyfunctional amine (e.g., triamine) is 2:1 to 140:1, 3:1 to 130:1, 4:1 to 120:1, 5:1 to 110:1, 6:1 to 100:1, 7:1 to 90:1, or especially 8:1 to 80:1. Monoanhydride groups can also be used. Non-limiting examples of monoanhydride groups include 4-amino-1,8-naphthalic anhydride, endo-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, citraconic anhydride, trans-1,2-cyclohexanedicarboxylic anhydride, 3,6-dichlorophthalic anhydride, 4,5-dichlorophthalic anhydride, tetrachlorophthalic anhydride, 3,6-difluorophthalic anhydride, 4,5-difluorophthalic anhydride, tetrafluorophthalic anhydride, maleic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, 2,2-dimethylglutaric anhydride. These include 3,3-dimethylglutaric anhydride, 2,3-dimethylmaleic anhydride, 2,2-dimethylsuccinic anhydride, 2,3-diphenylmaleic anhydride, phthalic anhydride, 3-methylglutaric anhydride, methylsuccinic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, 2,3-pyrazinedicarboxylic anhydride, or 3,4-pyridinedicarboxylic anhydride. In particular, the monoanhydride group may be phthalic anhydride.

[0078] In another embodiment, the polymer composition used to prepare the layer of the polymeric aerogel comprises a polyfunctional amine monomer having at least three primary amine functional groups. The polyfunctional amine may be a substituted or unsubstituted aliphatic polyfunctional amine, a substituted or unsubstituted aromatic polyfunctional amine, or a polyfunctional amine containing a combination of an aliphatic and two aromatic groups, or a combination of an aromatic and two aliphatic groups.A non-limiting list of possible polyfunctional amines includes propane-1,2,3-triamine, 2-aminomethylpropane-1,3-diamine, 3-(2-aminoethyl)pentane-1,5-diamine, bis(hexamethylene)triamine, N',N'-bis(2-aminoethyl)ethane-1,2-diamine, N',N'-bis(3-aminopropyl)propane-1,3-diamine, 4-(3-aminopropyl)heptane-1,7-diamine, N',N'-bis(6 ... (aminohexyl)hexane-1,6-diamine, benzene-1,3,5-triamine, cyclohexane-1,3,5-triamine, melamine, N-2-dimethyl-1,2,3-propanetriamine, diethylenetriamine, 1-methyl or 1-ethyl or 1-propyl or 1-benzyl-substituted diethylenetriamines, 1,2-dibenzyldiethylenetriamine, lauryldiethylenetriamine, N-(2-hydroxypropyl)diethylenetriamine , N,N-bis(l-methylheptyl)-N-2-dimethyl-1,2,3-propanetriamine, 2,4,6-tris(4-(4-aminophenoxy)phenyl)pyridine, N,N-dibutyl-N-2-dimethyl-l,2,3-propanetriamine, 4,4'-(2-(4-aminobenzyl)propane-1,3-diyl)dianiline, 4-((bis(4-aminobenzyl)amino)methyl)aniline, 4-(2-(bis(4-aminophenethyl)amino)ethylene Examples of suitable polyoxypropylene triamines include N,N,N',N'-tetrakis(4-aminophenyl)-1,4-phenylenediamine, polyoxypropylene triamines, octa(aminophenyl) polyhedral oligomeric silsesquioxanes, or combinations thereof. A specific example of a polyoxypropylene triamine is JEFFAMINE® T-403 from Huntsman Corporation, The Woodlands, TX USA. In certain embodiments, the aromatic polyfunctional amine may be 1,3,5-tris(4-aminophenoxy)benzene or 4,4',4''-methanetriyltrianiline.In some embodiments, the multifunctional amine contains three primary amine groups and one or more secondary and / or tertiary amine groups, for example, N',N'-bis(4-aminophenyl)benzene-1,4-diamine.

[0079] Non-limiting examples of capping agents or groups include amine, maleimide, nadimide, acetylene, biphenylene, norbornene, cycloalkyl, and N-propargyl, and those derived from reagents including 5-norbornene-2,3-dicarboxylic anhydride (nadic anhydride, NA), methylnadic anhydride, hexachloronadic anhydride, cis-4-cyclohexene-1,2-dicarboxylic anhydride, 4-amino-N-propargylphthalimide, 4-ethynylphthalic anhydride, and maleic anhydride, among others.

[0080] The characteristics or properties of the final polymer are greatly influenced by the selection of monomers used to produce the polymer. Factors to consider when selecting monomers include the properties of the final polymer, such as flexibility, thermal stability, coefficient of thermal expansion (CTE), coefficient of hydraulic expansion (CHE), and any other properties that are particularly desirable, as well as cost. In many cases, certain important properties of a polymer for a particular application can be identified. Other properties of the polymer may be less important or have a wide range of acceptable values; therefore, many different monomer combinations may be used.

[0081] In some examples, the backbone of the polymer may include a substituent. The substituent (e.g., oligomer, functional group, etc.) may be directly attached to the backbone or may be linked to the backbone through a linking group (e.g., tether or flexible tether). In other embodiments, compounds or particles may be incorporated (e.g., mixed and / or encapsulated) into the polyimide structure without being covalently attached to the polyimide structure. In some examples, the incorporation of compounds or particles may be performed during the polyamic reaction process. In some examples, the particles may aggregate, thereby producing polyimides with domains containing different concentrations of non-covalently bound compounds or particles.

[0082] Specific properties of polyimides can be influenced by incorporating certain compounds into the polyimide. The choice of monomer is one way to influence specific properties. Another way to influence properties is by adding compounds or property-modifying moieties to the polyimide.

[0083] C. Preparation of polymer aerogel layers Polymeric aerogel films that may be used in at least some of the laminates of the present invention are commercially available. Non-limiting examples of such films include Blueshift AeroZero® rolled film (available from Blueshift Materials, Inc. (Spencer, Massachusetts)) and Airloy® film (available from Aerogel Technologies, LLC), with Blueshift AeroZero® rolled film being preferred in some aspects.

[0084] Additionally, and in addition to the processes described below, polymer aerogels (such as films, stock shapes, or monoliths) can be made using methods described in WO 2014 / 189560 to Rodman et al., US 2017 / 0355829 to Sakaguchi et al., US 2018 / 078512 to Yang et al., US 2018 / 140804 to Sakaguchi et al., and US 2019 / 006184 to Irvin et al., International Application PCT / US2019 / 029191 to Ejaz et al., U.S. Patent Application Publication No. 2017 / 0121483 to Poe et al., and / or U.S. Patent No. 9,963,571 to Sakaguchi et al., all of which are incorporated by reference in their entireties.

[0085] The following provide non-limiting steps that may be used to make layers of polymeric aerogel suitable for use in the laminates of the invention. These steps may include: (1) preparation of the polymer gel, (2) optional solvent exchange, (3) drying the polymer solution to form the aerogel, and (4) bonding the polymeric aerogel film to a substrate.

[0086] 1. Polymer gel formation The first stage in the synthesis of an aerogel can be the synthesis of a polymerized gel. For example, if a polyimide aerogel is desired, at least one acid monomer can be reacted with at least one diamino monomer in a reaction solvent to produce a polyamic acid. As previously mentioned, many acid monomers and diamino monomers may be used to synthesize a polyamic acid. In one aspect, the polyamic acid is contacted with an imidization catalyst in the presence of a chemical dehydrating agent to produce a polymerized polyimide gel via an imidization reaction. "Imidization" is defined as the conversion of a polyimide precursor to an imide. Any imidization catalyst suitable for driving the conversion of a polyimide precursor to a polyimide state is suitable. Non-limiting examples of chemical imidization catalysts include pyridine, methylpyridine, quinoline, isoquinoline, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), triethylenediamine, lutidine, N-methylmorpholine, triethylamine, tripropylamine, tributylamine, other trialkylamines, 2-methylimidazole, 2-ethyl-4-methylimidazole, imidazole, other imidazoles, and combinations thereof. Any dehydrating agent suitable for use in forming imide rings from amic acid precursors is suitable for use in the methods of the present invention. Preferred dehydrating agents include at least one compound selected from the group consisting of acetic anhydride, propionic anhydride, n-butyric anhydride, benzoic anhydride, trifluoroacetic anhydride, phosphorus trichloride, and dicyclohexylcarbodiimide.

[0087] In one aspect of the invention, one or more diamino monomers and one or more polyfunctional amine monomers are premixed in one or more solvents and then one or more dianhydrides (e.g., diacid monomers) are added in successive small amounts at predetermined time increments while monitoring the viscosity. The desired viscosity of the polymerization solution can range from 50 to 20,000 cP, or particularly from 500 to 5,000 cP. Non-crosslinked aerogels can be prepared by carrying out the reaction with incremental additions of dianhydrides while monitoring the viscosity. For example, a triamine monomer (23 equivalents) can be added to the solvent to obtain a 0.0081 molar solution. A first diamine monomer (280 equivalents) can be added to the solution, followed by a second diamine monomer (280 equivalents). The dianhydrides (552 equivalents total) can then be added in successive small amounts at predetermined time increments while monitoring the viscosity. The dianhydrides can be added until the viscosity reaches 1,000 to 1,500 cP. For example, a first portion of the dianhydride can be added, the reaction can be stirred (e.g., 20 minutes), a second portion of the dianhydride can be added, and then a sample of the reaction mixture can be analyzed for viscosity. After stirring for an additional period of time (e.g., 20 minutes), a third portion of the dianhydride can be added and a sample can be taken for viscosity analysis. After further stirring for a desired period of time (e.g., 10 hours to 12 hours), the monoanhydride (96 equivalents) can be added. After reaching the target viscosity, the reaction mixture can be stirred for a desired period of time (e.g., 10 hours to 12 hours) or until the reaction is deemed complete.

[0088] The reaction temperature for gel formation can be determined by routine experimentation depending on the starting materials. In preferred embodiments, the temperature can be any one or more of 15°C, 20°C, 30°C, 35°C, 40°C, and 45°C, or between any two thereof. After a desired time (e.g., about 2 hours), the product can be isolated (e.g., filtered), and then the nitrogen-containing hydrocarbon (828 equivalents) and the dehydrating agent (1214 equivalents) can be added. The addition of the nitrogen-containing hydrocarbon and / or dehydrating agent can be done at any temperature. In some embodiments, the nitrogen-containing hydrocarbon and / or dehydrating agent is added to the solution at 20°C to 28°C (e.g., room temperature) and stirred at that temperature for a desired time. In some examples, the solution temperature is increased to 150°C after the nitrogen-containing hydrocarbon and / or dehydrating agent is added.

[0089] Reaction solvents can include dimethyl sulfoxide (DMSO), diethyl sulfoxide, N,N-dimethylformamide (DMF), N,N-diethylformamide, N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 1-methyl-2-pyrrolidinone, N-cyclohexyl-2-pyrrolidone, 1,13-dimethyl-2-imidazolidinone, diethylene glycol dimethoxy ether, o-dichlorobenzene, phenol, cresol, xylenol, catechol, butyrolactone, hexamethylphosphoramide, and mixtures thereof. Reaction solvents and other reactants can be selected based on compatibility with the materials and methods applied; that is, whether the polymerized polyamic acid amide gel is cast onto a support film, injected into a moldable part, or cast into a shape for further processing into a workpiece. In certain embodiments, the reaction solvent is DMSO.

[0090] In one non-limiting manner, the formation of macropores, as opposed to small mesopores and micropores, can be controlled primarily by controlling the polymer / solvent dynamics during gel formation. In this way, the pore structure can be controlled, and the amount and volume of macroporous, mesoporous, and microporous cells can be controlled. For example, a curing additive that reduces the solubility of the resulting polymer during polymerization, such as 1,4-diazabicyclo[2.2.2]octane, can produce a polymer gel containing more macropores compared to another curing additive that improves the solubility of the resulting polymer, such as trimethylamine. In another specific non-limiting example, when producing polyimide aerogels, the ratio of rigid amines (e.g., p-phenylenediamine (p-PDA)) to more flexible diamines (e.g., -ODA) incorporated into the polymer backbone can be increased to favor the production of macropores over small mesopores and micropores.

[0091] The polymer solution may be cast onto a cast sheet, optionally covered with a support film, for a period of time. Casting may include spin casting, gravure coating, three-roll coating, roll-on knife coating, slot-die extrusion, dip coating, Mayer rod coating, or other techniques. In one embodiment, the cast sheet is a polyethylene terephthalate (PET) cast sheet. After time, the polymerized reinforced gel is removed from the cast sheet and prepared for the solvent exchange step. In some embodiments, the cast film may be heated stepwise to high temperatures to remove the solvent and convert the amic acid functional groups in the polyamic acid to imides by a dehydration cycloreaction, also called imidization. In some examples, the polyamic acid may be converted to polyimide in solution by the addition of a chemical dehydrating agent, a catalyst, and / or heat.

[0092] In some embodiments, polyimide polymers can be produced by preparing a polyamic acid polymer in a reaction vessel, then forming the polyamic acid into a sheet or film, followed by treatment with a catalyst or heat and catalyst to convert the polyamic acid into a polyimide.

[0093] Wet gels used to prepare aerogels may be prepared by any known gel-forming technique, for example, by adjusting the pH and / or temperature of a dilute metal oxide solution to the point where gelation occurs.

[0094] 2. Optional Solvent Exchange After synthesizing the polymer gel, in certain instances, it may be desirable to perform a solvent exchange, in which the reaction solvent is replaced with a more desirable second solvent. Thus, in one embodiment, a solvent exchange can be performed in which the polymer gel is placed inside a pressure vessel and submerged in a mixture containing the reaction solvent and the second solvent. A high pressure atmosphere is then created inside the pressure vessel, which forces the second solvent into the polymer gel and replaces some of the reaction solvent. Alternatively, the solvent exchange step may be performed without the use of a high pressure environment. It may be necessary to perform multiple solvent exchanges. In some embodiments, solvent exchange is not required.

[0095] The time required to perform a solvent exchange will vary depending on the type of polymer undergoing the exchange and the reaction solvent and second solvent used. In one embodiment, each solvent exchange can take 1-168 hours, or any period therebetween, including 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, or 23, 24, 25, 50, 75, 100, 125, 150, 155, 160, 165, 166, 167, or 168 hours. In another embodiment, each solvent exchange can take approximately 1-60 minutes, or about 30 minutes. Exemplary second solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 3-methyl-2-butanol, 3,3-dimethyl-2-butanol, 2-pentanol, 3-pentanol, 2,2-dimethylpropan-1-ol, cyclohexanol, diethylene glycol, cyclohexanone, acetone, acetylacetone, 1,4-dioxane, diethyl ether, dichloromethane, trichloroethylene, chloroform, carbon tetrachloride, water, and mixtures thereof. In certain non-limiting embodiments, the second solvent may have a freezing point suitable for carrying out a supercritical or subcritical drying step. For example, at 1 atmosphere, tert-butyl alcohol has a freezing point of 25.5°C and water has a freezing point of 0°C. Alternatively, as described below, drying may be carried out without a supercritical or subcritical drying step, such as by evaporative drying techniques.

[0096] The temperature and pressure used in the solvent exchange step may be varied. The duration of the solvent exchange step can be adjusted by performing the solvent exchange at various temperatures or atmospheric pressures, or both, provided that the pressure and temperature within the pressure vessel do not cause either the first solvent or the second solvent to leave the liquid phase and become a gas, vapor, solid, or supercritical fluid. In general, higher pressures and / or temperatures decrease the amount of time required to perform the solvent exchange, and lower temperatures and / or pressures increase the amount of time required to perform the solvent exchange.

[0097] 3. Cooling and drying In one embodiment, after solvent exchange, the polymerized gel can be exposed to supercritical drying. In this example, the solvent in the gel can be removed by supercritical CO2 extraction.

[0098] In another embodiment, after the solvent exchange, the polymerized gel can be exposed to subcritical drying. In this example, the gel can be cooled below the freezing point of the second solvent and subjected to a freeze-drying or lyophilization process to produce an aerogel. For example, if the second solvent is water, the polymerized gel can be cooled below 0°C. After cooling, the polymerized gel can be subjected to a vacuum for a period of time to sublimate the second solvent.

[0099] In yet another embodiment, after the solvent exchange, the polymerized gel can be exposed to subcritical drying, optionally with heating, after most of the second solvent has been removed by sublimation. In this example, the partially dried gel material is heated to a temperature close to or above the boiling point of the second solvent for a period of time. The period can range from a few hours to a few days, with a typical period being about 4 hours. During the sublimation step, a portion of the second solvent present in the polymerized gel is removed, leaving a gel that may have macropores, mesopores, or micropores, or any combination thereof or all of such pore sizes. After the sublimation step is complete, or nearly complete, an aerogel is formed.

[0100] In yet another embodiment, after solvent exchange, the polymerized gel can be dried under ambient conditions, for example, by removing the solvent under a flow of gas (e.g., air, anhydrous gas, inert gas (e.g., nitrogen (N2) gas), etc.). Additionally, passive drying techniques can be used, such as simply exposing the gel to ambient conditions without an airflow.

[0101] Once cooled or dried, the films and stock shapes can be configured for use in the laminates of the present invention. For example, the films or stock shapes can be machined (e.g., by cutting or grinding) into the desired shape, such as square, rectangular, circular, triangular, irregular, random, etc. Also, as previously described, the films or stock shapes can be attached to a support material, such as with an adhesive. In an alternative embodiment, the support material can be incorporated into the matrix of the polymer aerogel, as described below.

[0102] 4. Incorporation of a reinforcing layer into the polymer aerogel matrix In addition to the above-mentioned method regarding the use of adhesives to bond the polymer aerogel to the support material, any embodiment of the present invention can include the incorporation of a support material into the polymer matrix to create a reinforced polymer aerogel without the use of adhesives. Of note, during the manufacture of non-reinforced polymer aerogels, a reinforced support film can be used as a carrier to support the gelled film during processing. During unwinding, the gelled film can be irreversibly pressed into the carrier film. Pressing the gelled film into the carrier film can provide substantial durability improvements. In another example, the polymer solution can be cast into the reinforcing or support material during the solution casting step described above.

[0103] Substrate selection and direct casting may allow for optimization (e.g., minimization) of the thickness of the resulting reinforced aerogel material. This process may also be extended to the production of fiber-reinforced polymer aerogels, with internally reinforced polyimide aerogels being provided as an example. The process may include (a) forming a polyamic acid solution from a mixture of dianhydride and diamine monomers in a polar solvent such as DMSO, DMAc, NMP, or DMF; (b) contacting the polyamic acid solution with the chemical curing and dehydrating agents listed above to initiate chemical imidization; (c) casting and infiltrating the polyamic acid solution onto a fiber support prior to gelation; (d) allowing the catalytic polyamic acid solution to gel around and within the fiber support during chemical imidization; (e) optionally performing a solvent exchange that may facilitate drying; and (f) removing the fugitive liquid phase contained within the gel by supercritical, subcritical, or ambient drying to obtain an internally reinforced aerogel.

[0104] D. Non-Limiting Aspects of the Invention The present invention can include the following non-limiting aspects.

[0105] Aspect 1: A laminate including a flame retardant layer having a flammability rating in accordance with at least one Plastic Flammability Standard and an aerogel layer, the laminate having opposing front and rear surfaces; the flame retardant layer defining at least a majority of the front surface; and the laminate having a thickness of 25.4 millimeters (mm) or less.

[0106] Aspect 2: The laminate of aspect 1, wherein the thickness of the laminate is 10 mm or less, preferably 5 mm or less, more preferably 2 mm or less, or even more preferably 0.3 mm to 2 mm.

[0107] Aspect 3: The laminate of any one of Aspects 1 or 2, wherein the flame-retardant layer has a thickness of 0.05 mm to 0.8 mm.

[0108] Aspect 4: The laminate of any one of aspects 1 to 3, wherein the flame retardant layer is not electrically insulating.

[0109] Aspect 5: The laminate of any one of aspects 1 to 3, wherein the flame-retardant layer is electrically insulating.

[0110] Aspect 6: The laminate of any one of Aspects 1 to 5, wherein the plastic flammability standard is UL94 5VA or UL94 5VB, and the flammability rating of the flame retardant layer complies with UL94 5VA or UL94 5VB.

[0111] Aspect 7. The laminate of any one of aspects 1 to 6, wherein the flammability rating of the laminate complies with the Plastic Flammability Standard, preferably UL94 5VB, more preferably UL94 5VA.

[0112] Aspect 8. The laminate of any one of aspects 1 to 7, wherein the flame retardant layer comprises fibers.

[0113] Aspect 9. The laminate of aspect 8, wherein the fibers are nonwoven fibers.

[0114] Aspect 10: The laminate of aspect 8, wherein the fibers are woven fibers.

[0115] Aspect 11. The laminate of any one of aspects 1-10, wherein the flame retardant layer comprises one or more of a metal hydroxide, an organic phosphate, an alumina hydroxide, an inorganic filler, and / or a metal oxide.

[0116] Aspect 12. The laminate of any one of aspects 1 to 11, wherein the flame retardant layer comprises a silicate.

[0117] Aspect 13. The laminate of aspect 12, wherein the silicate comprises mica, and the flame retardant layer preferably comprises at least 90% by weight of the mica.

[0118] Aspect 14. The laminate of any one of aspects 1 to 13, wherein the flame retardant layer comprises a ceramic, and preferably the flame retardant layer comprises at least 90% by weight of the ceramic.

[0119] Aspect 15. The laminate of aspect 14, wherein the ceramic comprises a metal oxide or a non-metal oxide or a combination thereof.

[0120] Aspect 16: The laminate of aspect 15, wherein the ceramic comprises alumina, beryllia, ceria, zirconia, a carbide, a boride, a nitride, or a silicide, or any combination thereof.

[0121] Aspect 17: The laminate of any one of aspects 1 to 16, wherein the flame retardant layer is halogen-free.

[0122] Aspect 18. The laminate of any one of Aspects 1 to 17, wherein the aerogel layer has a thickness between 0.05 mm and 0.254 mm.

[0123] Aspect 19: The laminate of any one of aspects 1 to 18, wherein the aerogel layer is a polymeric aerogel layer.

[0124] Aspect 20. The laminate of any one of aspects 1 to 19, wherein the polymer aerogel layer comprises at least 50% by weight, preferably at least 80% by weight, or more preferably at least 90% by weight polyimide.

[0125] Aspect 21: The laminate of any one of Aspects 1 to 20, wherein the aerogel layer has a decomposition temperature of 400°C or higher, preferably 400°C to 600°C.

[0126] Aspect 22: The laminate of any one of Aspects 1-21, comprising one or more adhesive layers bonded to the aerogel layer.

[0127] Aspect 23: The laminate of Aspect 22, wherein a first of the adhesive layers is disposed between the flame retardant layer and the aerogel layer.

[0128] Aspect 24: The laminate of Aspect 23, wherein the first adhesive layer has a melting or decomposition temperature greater than 500° C.

[0129] Aspect 25: The laminate of Aspect 23 or 24, wherein at least a portion of the rear surface is defined by a second of the adhesive layers, or a liner layer removably disposed on the second adhesive layer.

[0130] Aspect 26: The laminate of any one of Aspects 22-25, wherein each of the adhesive layers comprises a pressure sensitive adhesive.

[0131] Aspect 27: The laminate of any one of aspects 22-26, wherein each of the adhesive layers comprises a silicone adhesive compound and / or an epoxy compound.

[0132] Aspect 28: The laminate of any one of aspects 1-27, wherein any one, any combination, or all of the flame retardant layer, the aerogel layer, and the adhesive layer are perforated.

[0133] Aspect 29: The laminate of any one of Aspects 1 to 28, wherein when attached to a substrate, the laminate is capable of maintaining a temperature of the substrate at or below 500° C. when the front surface of the laminate is exposed to a temperature in excess of 500° C., preferably from 500° C. to 1,500° C., or more preferably from 700° C. to 1,200° C., for from 1 minute to 90 minutes, preferably for at least 5 minutes.

[0134] Aspect 30: The laminate of any one of aspects 1 to 29, wherein the laminate is disposed in a roll shape such that a portion of the front surface of the laminate faces a portion of the rear surface of the laminate.

[0135] Aspect 31: The laminate of any one of Aspects 1 to 30, further comprising a heat spreading layer.

[0136] Aspect 32. The laminate of Aspect 31, wherein the heat spreading layer comprises a metal having a thermal conductivity of at least 15 W / m·K, preferably from 15 W / m·K to 2,500 W / m·K.

[0137] Aspect 33. The laminate of aspect 32, wherein the metal comprises copper, aluminum, molybdenum, tungsten, rhenium, tantalum, niobium, stainless steel, nickel, or an alloy thereof.

[0138] Aspect 34. The laminate of aspect 32 or 33, wherein the heat spreading layer comprises at least 90% by weight of the metal.

[0139] Aspect 35. The laminate of Aspect 31, wherein the heat spreading layer comprises graphite.

[0140] Aspect 36: The laminate of Aspect 35, wherein the heat spreading layer comprises at least 90% by weight of the graphite.

[0141] Aspect 37: The laminate of any one of Aspects 31 to 36, wherein the heat dissipation layer has a thickness of 0.001 mm to 0.4 mm, preferably 0.01 mm to 0.05 mm.

[0142] Aspect 38. The laminate of any one of aspects 31 to 37, wherein the heat dispersion layer is disposed between the flame retardant layer and the aerogel layer.

[0143] Aspect 39: The laminate of Aspect 38, comprising a first adhesive layer disposed between the flame retardant layer and the heat distribution layer, and a second adhesive layer disposed between the heat distribution layer and the aerogel layer.

[0144] Aspect 40: The laminate of Aspect 39, wherein the first adhesive layer is in direct contact with the flame retardant layer and the heat spreading layer, and the second adhesive layer is in direct contact with the heat spreading layer and the aerogel layer.

[0145] Aspect 41: The laminate of Aspect 39 or 40, further comprising a third adhesive layer and a liner layer, the third adhesive layer being disposed between the aerogel layer and the liner layer.

[0146] Aspect 42: The laminate of aspect 41, wherein the third adhesive layer is in direct contact with the aerogel layer and the liner layer.

[0147] Aspect 43: The laminate of any one of Aspects 39-42, wherein the first, second, and / or third adhesive layer has a melting or decomposition temperature greater than 500° C.; comprises a pressure sensitive adhesive; and / or comprises a silicone adhesive compound and / or an epoxy compound.

[0148] Aspect 44: The laminate of any one of aspects 31-43, wherein any one, any combination, or all of the flame retardant layer, the heat dispersion layer, the aerogel layer, and the first, second, and third adhesive layers are perforated.

[0149] Aspect 45: The laminate of any one of aspects 1 to 44, further comprising a reinforcing layer.

[0150] Aspect 46: The laminate of aspect 45, wherein the reinforcing layer is attached to at least a portion of the flame retardant layer.

[0151] Aspect 47: The laminate of aspect 45 or 46, wherein the reinforcing layer is included within at least a portion of the volume of the flame retardant layer.

[0152] Aspect 48. The laminate of any one of aspects 45-47, wherein the reinforcing layer comprises fibers.

[0153] Aspect 49: The laminate of Aspect 48, wherein the fibers comprise glass fibers, carbon fibers, aramid fibers, thermoplastic fibers, thermoset fibers, ceramic fibers, basalt fibers, rock wool fibers, steel fibers, cellulosic fibers, or any combination thereof.

[0154] Aspect 50: The laminate of aspect 48 or 49, wherein the fibers are nonwoven fibers or woven fibers.

[0155] Aspect 51: An apparatus comprising one or more of the laminates of any one of Aspects 1-50, wherein a first of the laminates is bonded such that a front surface of the first laminate is positioned farther from the apparatus than a rear surface of the first laminate.

[0156] Aspect 52: The device of aspect 51, which is a battery.

[0157] Aspect 53: The apparatus of Aspect 52, wherein the battery is included in a vehicle, the vehicle including one or more wheels; and one or more electric motors, each configured to rotate at least one of the wheels; and the battery is in electrical communication with at least one of the electric motors.

[0158] Aspect 54: The apparatus of Aspect 52 or 53, further comprising a busbar in electrical communication with the battery; and wherein the one or more stacks include two or more stacks, a second of the stacks being coupled to the busbar such that a front side of the second stack is positioned farther from the busbar than a rear side of the second stack.

[0159] Aspect 55: The device of any one of Aspects 52 to 54, wherein the battery is a lithium ion battery.

[0160] Aspect 56: The device of aspect 51, which is a bus bar.

[0161] Aspect 57: The device of Aspect 51, which is a compression pad, a battery cell, a battery module, a battery pack, or a battery box.

[0162] Aspect 58: The device of Aspect 57, which is a compression pad, the compression pad comprising a compressible material.

[0163] Aspect 59: The device of Aspect 58, wherein the compressible material comprises foam.

[0164] Aspect 60: The device of aspect 58 or 59, wherein the compression pad is disposed between the first battery cell and the second battery cell.

[0165] Aspect 61: The device of Aspect 57, which is a battery cell.

[0166] Aspect 62: The device of Aspect 57, which is a battery module including at least two battery cells, and one or more of the laminates are disposed between the two battery cells.

[0167] Aspect 63: The device of Aspect 57, wherein the device is a battery pack including at least two battery modules, and one or more of the laminates are disposed between the two battery modules.

[0168] Aspect 64: The apparatus of aspect 57, which is a battery box including an exterior surface, an interior surface, and an interior volume.

[0169] Aspect 65: The device of Aspect 64, wherein one or more of the laminates cover at least a portion of the outer surface, at least a portion of the inner surface, or both.

[0170] Aspect 66: The apparatus of Aspect 64 or 65, wherein the internal volume is configured to contain the compression pad, the battery cell, the battery module, or the battery pack.

[0171] Aspect 67: The apparatus of Aspect 66, wherein the internal volume includes the compression pad, the battery cell, the battery module, the battery pack, or any combination thereof.

[0172] Aspect 68: The apparatus of any one of Aspects 57 to 67, wherein the compression pad, the battery cell, the battery module, the battery pack, or the battery box is included in a vehicle, the vehicle including one or more electric motors.

[0173] Aspect 69: The apparatus of Aspect 68, wherein the vehicle is an automobile, an aircraft, a train, a motorcycle, a ship, or a spacecraft.

[0174] Aspect 70: The device of Aspect 51, which is a cable.

[0175] Aspect 71: The apparatus of Aspect 70, wherein the cable has a length and a width, the length being greater than the width.

[0176] Aspect 72: The apparatus of aspect 70 or 71, wherein the cable is conductive.

[0177] Aspect 73: The apparatus of any one of Aspects 70-72, wherein the cable has a diameter of 0.0003 inches to 10 inches, preferably 0.001 inches to 1 inch.

[0178] Aspect 74: The apparatus of any one of Aspects 70-73, wherein the cable is included in a missile, rocket, artillery piece, manned aerial vehicle, unmanned aerial vehicle, ground vehicle, sea vehicle, or spacecraft.

[0179] Aspect 75: The apparatus of Aspect 74, wherein the vehicle is a spacecraft or an aircraft.

[0180] Aspect 76: The apparatus of any one of Aspects 51 to 75, wherein the one or more laminates are capable of maintaining a temperature of the apparatus at or below 500°C when the front surface of the laminate is exposed to a temperature greater than 500°C, preferably between 500°C and 1,500°C, or more preferably between 700°C and 1,200°C, for between 1 minute and 90 minutes, preferably at least 5 minutes.

[0181] Aspect 77: A method of thermally protecting a device of any one of aspects 51-76, comprising bonding the laminate of any one of aspects 1-50 to the device.

[0182] Aspect 78: The method of Aspect 77, wherein the stack is positioned relative to the device such that the front surface of the stack is positioned farther from the device than the rear surface of the stack.

[0183] Aspect 79: The method of Aspect 78, wherein the front surface of the laminate is exposed to a temperature of greater than 500° C. to 1,500° C. for a period of 1 minute to 90 minutes, preferably at least 5 minutes, and the temperature of the apparatus does not exceed 500° C. during that period.

[0184] Aspect 80: The method of Aspect 78, wherein the front surface of the laminate is exposed to a temperature of 700°C to 1,200°C for a period of 1 minute to 90 minutes, preferably at least 5 minutes, and the temperature of the apparatus does not exceed 500°C during that period.

[0185] Aspect 81: The laminate of any one of Aspects 1 to 50, wherein the flame retardant layer includes a first flame retardant layer and a second flame retardant layer, the first and second flame retardant layers being disposed on opposing sides of the aerogel layer. EXAMPLES

[0186] The present invention will be described in detail by way of specific examples.The following examples are provided for illustrative purposes only and are not intended to limit the present invention in any manner.Those skilled in the art will easily recognize various non-critical parameters that can be changed or modified to obtain essentially the same results.

[0187] Example 1 (Flame and Thermal Barrier Laminate Testing) Materials. 12" x 1.6" x 0.2" copper bars were obtained from McMaster Carr. The AeroZero (AZ) film used (6.5 mil) was from Blueshift Materials Inc. and the flame retardant barrier material used was 3M FRB WT145 (5.8 mil) from 3M. Laminate test specimens were assembled using a pressure sensitive silicone adhesive, SA6101LR, from FLEXcon.

[0188] Test Setup. Flame and thermal barrier sample effectiveness testing was performed using a bare copper rod as the test substrate. The copper rod was fixed horizontally to a support. A thermocouple was attached using Kapton tape to secure it to the center of the copper rod. The test sample was wrapped around the copper rod prior to exposure to flame.

[0189] The test specimen was wrapped around 2 inches of a 12 inch copper rod with the tip of the thermocouple directly contacting the copper rod directly below the test specimen. The test specimen was attached to the copper rod using a silicone pressure sensitive adhesive. A flame source (Bunsen burner) with a flame temperature set at 700°C was positioned 1.5 inches from the test specimen with the flame in direct contact with the horizontally positioned test specimen. Temperatures from the thermocouple were recorded at 30 second intervals for 10 minutes.

[0190] The test configuration is shown in Figure 8. As shown, the test setup 400 included a copper bar 40, test specimens 42, 44, a thermocouple 46, and a flame source 48. The layups of the flame and thermal barrier test specimens 42, 44 are shown in Figure 9. Each included one or more AeroZero aerogel layers as the thermal insulation layer 16, with adhesive layers 20, 22 attaching the aerogel layers directly to the copper bar 40 and the flame retardant layer 18. The flame retardant layer 18 faced the flame source 48. Several specimens were tested and their specific layups are shown in Table 1.

[0191] Table 1: Flame and thermal barrier test specimen layup TIFF2025503894000002.tif46136

[0192] The thermal profiles of the tested samples are shown in Figure 10. For each sample, the temperature of the copper bar after 5 and 10 minutes of the sample being exposed to the flame is shown in Table 2. These temperatures were compared to the control sample, i.e. a copper bar without a barrier. The test showed that when one or two insulation layers (here AeroZero film) were combined with a flame retardant layer (here FRM WT-145), the temperature of the copper bar was significantly reduced, thus demonstrating a surprising synergy between the insulation and flame retardant layers.

[0193] (Table 2) Temperature of copper rod during sample exposure to flame TIFF2025503894000003.tif41166

[0194] Examples 2 to 7 (Flame and Thermal Barrier Laminate Testing) 1000°C Flame Test Setup. Further testing of the flame and thermal barrier samples was performed using test setup 500, shown in FIG. 11. Test setup 500 was substantially similar to test setup 400, with the following exceptions: Here, the flame was 3 inches high, 2 inches wide, had a temperature of 1,000°C ± 30°C, and the base of the flame was positioned 2.5 inches away from the test sample 44. Additionally, some tests were performed without a test substrate, while others were performed with a test substrate comprising an 8 inch by 8 inch plate of aluminum, steel, and carbon fiber composite. In the tests using the test substrate, instead of two samples 42, 44, only one sample 44 was bonded to the flame-facing side of the test substrate. Finally, two thermocouples, 46a and 46b, were used. Thermocouple 46a was in direct contact with the flame to measure the flame temperature, and thermocouple 46b was placed on the laminate test sample (if no test substrate was used) or on the side of the test substrate not facing the flame (i.e., "cold") All thermal profiles described in Examples 2-7 are based on the temperature recorded by thermocouple 46b.

[0195] Example 2 Flame and thermal barrier laminate test specimens having the layups shown in Table 3 were exposed to a 1,000°C flame for 600 seconds (10 minutes). The laminate test specimens were not adhered to the test substrate. In this example, a laminate having only a flame retardant layer ("FRB") was compared to a laminate combining an FRB with a thermal insulation layer. The FRB tested was a type FRB NT381 manufactured by 3M.

[0196] Table 3: Flame and thermal barrier test specimen layup TIFF2025503894000004.tif31166

[0197] The thermal profiles of the samples in Table 3 are shown in Figure 12. As shown, the laminates containing the FRB and the insulating layer exhibited both a lower initial heating rate and a lower temperature after 5 minutes (312°C vs. 341°C) than the laminates containing only the FRB.

[0198] Example 3 Flame and thermal barrier laminate test specimens having the layups shown in Table 4 were exposed to a 1,000°C flame for 25 minutes. The laminate test specimens were not adhered to the test substrate. In this example, one of the specimens included an additional heat spreading layer (a 0.05 mm thick graphite layer) placed between the FRB facing the flame and one of the insulation layers.

[0199] Table 4: Flame and thermal barrier test specimen layup TIFF2025503894000005.tif31166

[0200] The thermal profiles of the samples in Table 4 are shown in Figure 13. This data shows that adding a heat spreader layer between the FRB facing the flame and the insulation layer further reduces the temperature of the cold side of the laminate. The primary heating rate of the laminate with the heat spreader layer was similar to that of the laminate without the heat spreader layer for about the first 3 minutes, but after 3 minutes, the laminate with the heat spreader layer was superior to the laminate without the heat spreader layer, including in terms of heating rate. These improvements are quantified in Table 5, which shows the laminate cold side temperatures at 5, 10, and 25 minutes of sample exposure to the flame.

[0201] Table 5: Temperature of the cold side of the laminate during sample exposure to flame TIFF2025503894000006.tif31166

[0202] Example 4 Flame and thermal barrier laminate test specimens of three different thicknesses (0.57 mm, 0.70 mm, and 1.17 mm) were bonded to 8 inch by 8 inch low carbon steel plates of 0.7 mm thickness and exposed to a flame at 1,000° C. for 600 seconds (10 minutes). The laminate test specimen layups are shown in Table 6.

[0203] Table 6: Flame and thermal barrier test specimen layups TIFF2025503894000007.tif33166

[0204] The thermal profiles of the samples in Table 6, along with that of a control ("No FRB") consisting of a steel plate with no laminate attached, are shown in Figure 14. As the data shows, both the primary heating rate (measured within the first 200 seconds) and the maximum temperature (measured at 600 seconds) of the cold side of the substrate decreased with increasing laminate thickness. In particular, for both the 0.70 mm and 1.17 mm thick laminates, the maximum temperature of the cold side of the substrate remained below 350°C during the 600 seconds (10 minutes) of flame exposure.

[0205] Example 5 Flame and thermal barrier laminate test specimens, including those with and without a 0.05 mm thick heat spreading graphite layer, were bonded to 1.0 mm thick 8 in. x 8 in. carbon fiber composite plates and exposed to a 1000° C. flame for 25 minutes. The laminate test specimen layups are shown in Table 7.

[0206] Table 7. Flame and thermal barrier test specimen layups TIFF2025503894000008.tif31166

[0207] The thermal profiles of the laminates in Table 7 are shown in Figure 15, along with the thermal profile of a control ("No FRB") consisting of a carbon fiber composite plate with no laminate attached. Without the protective laminate, the carbon fiber composite plate began to burn within 10 seconds of exposure to the flame and produced a large amount of smoke. The temperature of the cold side of the carbon fiber composite plate rose rapidly and reached 200°C within 40 seconds. The test was stopped due to the production of a large amount of smoke and the decomposition of the carbon fiber composite plate. When protected with a flame and thermal barrier laminate that did not include a heat spreading layer, the primary heating rate was significantly reduced: it took about 2 minutes for the cold side of the carbon fiber composite plate to reach 200°C. Also, the maximum temperature of the cold side of the carbon fiber composite plate was 355°C after 10 minutes of flame exposure and did not increase any further during the 25 minute test period.

[0208] The flame and thermal barrier laminates including the heat spreading layer showed improved performance with respect to both the primary heating rate and the maximum temperature of the cold side of the carbon fiber composite plate. In particular, the primary heating rate shifted slightly to the right, reaching 200°C after 2.8 minutes, and the maximum temperature of the cold side of the carbon fiber composite plate was 333°C during the 25 minute flame exposure. These improvements are further quantified in Table 8, which shows the substrate cold side temperatures at 5, 10, and 25 minutes of sample exposure to the flame.

[0209] Table 8: Substrate cold side temperature during sample exposure to flame TIFF2025503894000009.tif31166

[0210] In addition, as shown in FIG. 16, for both of the laminates in Table 7, no burn-through of the carbon fiber composite plate was observed during testing.

[0211] Example 6 A 1.17 mm thick FRB / AeroZero / AeroZero / FRB flame and thermal barrier laminate from Table 3 was bonded to an 8 inch by 8 inch aluminum sheet having a thickness of 0.025 mm (1 mil) and exposed to a 1,000° C. flame for 25 minutes. The thermal profile of this laminate is shown in FIG. 17. As shown, the thermal profile includes a gradual increase in the aluminum sheet temperature, reaching a maximum of 325° C. during the 25 minute test: well below the melting point of aluminum. In fact, no burn-through of the aluminum sheet was observed during the test, which is shown in FIG. 18.

[0212] Example 7 Several flame and thermal barrier laminates were tested for thermal conductivity according to ASTM C518: "Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus". The instrument used was a Fox 50 heat flow meter manufactured by TA instruments. The layup, thermal conductivity, and density of the laminates tested are listed in Table 9.

[0213] Table 9. Flame and Thermal Barrier Test Sample Properties TIFF2025503894000010.tif68128

[0214] The foregoing specification and examples provide a complete description of the structure and use of the exemplary embodiments. Although certain embodiments have been described above in some detail or in connection with one or more individual embodiments, those skilled in the art may make many modifications to the disclosed embodiments without departing from the scope of the present invention. Thus, it is not intended that the various exemplary embodiments of the apparatus and method be limited to the particular forms disclosed. Rather, they include all modifications and alternatives that fall within the scope of the claims, and embodiments other than those shown may include some or all of the features of the illustrated embodiments. For example, elements may be omitted or combined in a unitary structure and / or connections may be substituted. Furthermore, where appropriate, aspects of any of the embodiments described above may be combined with aspects of any other of the embodiments described above to form further embodiments having equivalent or different characteristics and / or functions and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or to several embodiments.

[0215] The claims are not intended to, and should not be construed as including, means-plus-function or step-plus-function limitations, unless such limitations are expressly recited in a given claim using the words "means" or "step," respectively.

Claims

1. a flame-retardant layer having a flammability rating in accordance with at least one plastic flammability standard; Aerogel layer and A laminate comprising: the laminate having opposing front and rear surfaces; the flame-retardant layer defines at least a majority of the front surface; and A laminate having a thickness of 25.4 millimeters (mm) or less.

2. 2. The laminate of claim 1, wherein the thickness of the laminate is 10 mm or less, preferably 5 mm or less, more preferably 2 mm or less, or even more preferably 0.3 mm to 2 mm.

3. 2. The laminate according to claim 1, wherein the flame retardant layer has a thickness of 0.05 mm to 0.8 mm.

4. 2. The laminate of claim 1, wherein the plastic flammability standard is UL94 5VA or UL94 5VB, and the flammability rating of the flame retardant layer complies with UL94 5VA or UL94 5VB.

5. 2. The laminate of claim 1, wherein the flammability rating of the laminate complies with the plastic flammability standard, preferably UL94 5VB, more preferably UL94 5VA.

6. The laminate of claim 1 , wherein the flame retardant layer comprises one or more of a metal hydroxide, an organic phosphate, an alumina hydroxide, an inorganic filler, and / or a metal oxide.

7. 2. The laminate of claim 1, wherein the flame retardant layer comprises a silicate, and the flame retardant layer preferably comprises at least 90% by weight of the silicate.

8. 10. The laminate of claim 1, wherein the flame retardant layer comprises a ceramic, and preferably comprises at least 90% by weight of the ceramic.

9. 10. The laminate of claim 1, wherein the aerogel layer comprises at least 50% by weight, preferably at least 80% by weight, or more preferably at least 90% by weight of polyimide.

10. 10. The laminate of claim 1, comprising one or more adhesive layers coupled to the aerogel layer, the adhesive layers comprising a first adhesive layer disposed between the flame retardant layer and the aerogel layer.

11. The laminate of claim 10 , wherein at least the first of the adhesive layers comprises a pressure sensitive adhesive.

12. 10. The laminate of claim 1, wherein when attached to a substrate, the temperature of the substrate is capable of being maintained at or below 500°C when the front surface of the laminate is exposed to a temperature greater than 500°C, preferably between 500°C and 1,500°C, or more preferably between 700°C and 1,200°C, for a period of between 1 minute and 90 minutes, preferably at least 5 minutes.

13. 10. The laminate of claim 1, further comprising a heat spreading layer.

14. 14. The laminate of claim 13, wherein the heat spreading layer comprises a metal having a thermal conductivity of at least 15 W / m·K, preferably between 15 W / m·K and 2,500 W / m·K.

15. 15. The laminate of claim 14, wherein the metal comprises copper, aluminum, molybdenum, tungsten, rhenium, tantalum, niobium, stainless steel, nickel, or an alloy thereof.

16. 15. The laminate of claim 14, wherein the heat spreading layer comprises at least 90% by weight of the metal.

17. 14. The laminate of claim 13, wherein the heat spreading layer comprises graphite, preferably at least 90% by weight of said graphite.

18. 15. The laminate of claim 14, wherein the heat spreading layer is disposed between the flame retardant layer and the aerogel layer.

19. 19. A device comprising one or more stacks according to any one of claims 1 to 18, wherein a first of the stacks is bonded such that the front surface of the first stack is positioned further from the device than the rear surface of the first stack.

20. 20. The device of claim 19, wherein the device is a compression pad, a battery cell, a battery module, a battery pack, or a battery box.

21. 20. The device of claim 19, wherein the device is a conductive cable.

22. 19. The laminate of any one of claims 1 to 18, wherein the flame retardant layer comprises a first flame retardant layer and a second flame retardant layer, the first and second flame retardant layers being disposed on opposite sides of the aerogel layer.

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