Conductive composite and method for manufacturing the same

Abstract

To provide a conductive composite material having sufficient properties such as breaking elongation, tensile strength and thermal stability even when produced at a high particle filling rate, and to provide a method for producing the conductive composite material.SOLUTION: A conductive composite (2) includes a first layer of elastomeric polymer (4), a layer of conductive paste (6) on the first layer of elastomeric polymer, and a second layer of elastomeric polymer (8) on the layer of conductive paste. A reinforcing mesh (10) is provided in contact with the layer of conductive paste.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to conductive composites and methods for making the same. [Background technology]

[0002] Conductive composites broadly include any composite that has high electrical or thermal conductivity. These conductive composites have applications in a wide range of fields, such as telecommunications, power generation and distribution, defense, aeronautics, machinery, and many others.

[0003] Conductive composites are generally manufactured and / or have the properties of a polymer material by incorporating solid conductive particles into it. In order to achieve this, that is, to realize the percolation phenomenon, a high loading is required. To achieve this, the polymer must be packed with particles at a high density, typically exceeding 45% by volume. Such particle packings typically require rigid polymers. This results in conductive films and coatings made with such particle packings exhibiting properties such as elongation at break, tensile strength, and thermal stability that are insufficient or unsuitable for use.

[0004] Therefore, those skilled in the art of conductive composites continue to research and develop. Summary of the Invention

[0005] In one embodiment, the conductive composite comprises a first layer of elastic polymer, a layer of conductive paste on the first layer of elastic polymer, and a second layer of elastic polymer on the layer of conductive paste, with a reinforcing mesh in contact with the layer of conductive paste.

[0006] In another embodiment, a method for making a conductive composite includes forming a first layer of elastic polymer, forming a layer of conductive paste reinforced with a reinforcing mesh on the first layer of elastic polymer, and forming a second layer of elastic polymer on the layer of conductive paste.

[0007] Other embodiments of the conductive composites and methods for making conductive composites of the present disclosure will become apparent from the following detailed description, the accompanying drawings, and the claims. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of an exemplary conductive composite according to an exemplary embodiment of the present description; [Figure 2] 2 is a perspective cross-sectional view of the exemplary conductive composite shown in FIG. 1 taken along lines AA and BB. [Figure 3A-3C] 3A-3C are perspective views illustrating steps for manufacturing the exemplary conductive composite of FIGS. 1 and 2. [Figure 4] FIG. 1 is a flow diagram of an aircraft production and service method. [Figure 5] FIG. 1 is a block diagram of an aircraft. DETAILED DESCRIPTION OF THE INVENTION

[0009] As shown in FIGS. 1 and 2, the conductive composite 2 includes a first layer of elastic polymer 4, a layer of conductive paste 6 on the first layer of elastic polymer 4, a second layer of elastic polymer 8 on the layer of conductive paste 6, and a reinforcement layer 8 in contact with the layer of conductive paste 6. and a mesh 10.

[0010] An elastic polymer is a polymer that exhibits elasticity at high strain levels. In one aspect, the elastic polymers described herein have an elongation to break of greater than about 50%. In another aspect, the elastic polymers described herein have an elongation to break of greater than about 100%. In yet another aspect, the elastic polymers described herein have an elongation to break of greater than about 200%. Elongation to break is a value that represents the percentage of length that a material can extend to when subjected to a tensile force before breaking. Elongation to break is expressed as a percentage of the original length.

[0011] In one aspect, the elastic polymers described herein are electrical insulators. In one aspect, the elastic polymers described herein have a conductivity of about 1×10 -8 In another aspect, the elastic polymers described herein are electrical insulators with electrical conductivities of less than about 1×10 -9 In yet another aspect, the elastomeric polymers described herein are electrical insulators with electrical conductivities of less than about 1×10 -10 S It is an electrical insulator with a dielectric strength of less than 1 / m.

[0012] The first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 can include at least one of a thermoplastic polymer, a thermosetting polymer, and a combination thereof. In one aspect, elastomeric polymers suitable for the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 have a viscosity of about 1,000 cP to about 100,000 cP under typical processing conditions. In another aspect, elastomeric polymers suitable for the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 have a viscosity of about 1,000 cP to about 25,000 cP under typical processing conditions. In yet another aspect, the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 have a viscosity of about 25,000 cP to about 50,000 cP under typical processing conditions. In yet another aspect, elastomeric polymers suitable for the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 have a viscosity of about 50,000 cP to about 75,000 cP under typical processing conditions. In yet another aspect, suitable elastomeric polymers for the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 have a viscosity of about 75,000 cP to about 100,000 cP under typical processing conditions. In particular embodiments, suitable thermoplastic elastomers for use have a viscosity of about 1,000 cP to about 50,000 cP under typical processing conditions. As used herein, the term "typical processing conditions" includes temperatures of about room temperature (about 25°C) to about 400°C, temperatures of about room temperature to about 200°C, and temperatures of about room temperature to about 100°C. Techniques for measuring viscosity include viscometers, rheometers, or other suitable viscosity testing devices. Such thermoplastic elastomers are suitable for fabricating flexible materials.

[0013] Suitable elastomeric polymers for the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 include at least one of thermoplastic polymers, thermosetting polymers, and combinations thereof. For example, suitable elastomeric polymers for the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 include siloxane, fluorosiloxane, perfluoropolyether, polybutadiene, polyester, polycarbonate, polyurethane, polyurea, polyurethaneurea, epoxy, acrylate, natural rubber, butyl rubber, polyacrylonitrile, ethylene propylene diene monomer (EPDM) rubber, or combinations thereof. The first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 may be made from the same polymer composition or different polymer compositions.

[0014] In the context of this description, a paste refers to any highly viscous fluid. The pastes described herein do not harden or solidify to a solid state; rather, the pastes described herein maintain a highly viscous fluid state. In one aspect, the pastes described herein are materials with viscosities ranging from about 2,000 cP to about 1,000,000 cP. In another aspect, the pastes described herein are materials with viscosities ranging from about 2,000 cP to about 500,000 cP. In yet another aspect, the pastes described herein are materials with viscosities ranging from about 2,000 cP to about 100,000 cP. It is a fee.

[0015] A conductive paste is a paste that has the property of conducting an electric current. In one aspect, the conductive paste described herein has a conductivity of about 1×10 1 S / m paste. On the other hand, The conductive paste described herein has a conductivity of about 1×10 2 It is a paste of S / m. In another aspect, the conductive paste described herein has a conductivity of about 1×10 3 S / m paste In yet another aspect, the conductive paste described herein has a conductivity of about 1×10 4 S In yet another aspect, the conductive paste described herein has a conductivity of about 1×10 5 The conductive paste (6) layer is homogeneous and The surface may also be heterogeneous.

[0016] In one aspect, the conductive paste includes a metal or metal alloy having a melting temperature (e.g., melting point) of less than about 60°C. In one aspect, the melting temperature (e.g., melting point) of the metal or metal alloy is less than about 50°C. In another aspect, the melting temperature (e.g., melting point) of the metal or metal alloy is less than about 40°C. In yet another aspect, the melting temperature (e.g., melting point) of the metal or metal alloy is less than about 30°C. In yet another aspect, the melting temperature (e.g., melting point) of the metal or metal alloy is less than about 25°C. In yet another aspect, the melting temperature (e.g., melting point) of the metal or metal alloy is less than about 20°C. The conductive paste described herein is not limited to those including a metal or metal alloy. For example, the conductive paste described herein may include a conductive polymer having a melting temperature (e.g., melting point) of less than 60°C instead of a metal or metal alloy.

[0017] The metal or metal alloy contained in the conductive paste having a melting temperature (e.g., melting point) of less than about 60°C can include any metal or metal alloy having a melting temperature of less than about 60°C. In one aspect, the metal or metal alloy includes at least one of gallium, mercury, indium, tin, bismuth, phosphorus, lead, zinc, cadmium, antimony, and combinations thereof. Examples of suitable metals include gallium and mercury. Examples of suitable alloys include alloys including gallium, mercury, indium, tin, bismuth, phosphorus, lead, zinc, cadmium, antimony, and combinations thereof. In certain embodiments, the alloy includes at least about 50% by weight of gallium, bismuth, indium, mercury, or combinations thereof. In certain embodiments, the melting temperature of the alloy can be adjusted by including tin, phosphorus, lead, zinc, cadmium, antimony, or combinations thereof. In one embodiment, the alloy used in the conductive composite of the present disclosure comprises indium and about 50% to about 97% gallium by weight. In another embodiment, the low melting point alloy used to form the conductive composite of the present disclosure comprises about 15% to about 30% indium by weight, about 55% to about 80% gallium by weight, and at least one metal selected from tin and zinc. The weight percentages refer to the weight percentage of each component in the metal or metal alloy as a percentage of the total weight of the metal or metal alloy. Suitable gallium alloys are available from Indium Corporation. Examples of suitable alloys include Indalloy 46L, Indalloy 51, Indalloy 60, Indalloy 77, Indalloy 14, Indalloy 15, Indalloy 117, Indalloy 16, Indalloy 17, Indalloy 136, and Indalloy 19.

[0018] In one aspect, the layer of conductive paste includes a thickener. When a thickener is used, it is typically used in combination with a metal or alloy having a melting temperature of less than about 60° C., and thus the thickener is a component of the layer of conductive paste.

[0019] The thickener may be, for example, at least one of an organic thickener, an inorganic thickener, and a combination thereof. When the thickener comprises an organic thickener, the organic thickener can comprise, for example, at least one of maltose, carbon, and combinations thereof. When the thickener comprises an inorganic thickener, the inorganic thickener can comprise, for example, silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, or the like. and combinations thereof.

[0020] In certain embodiments, the thickener has an average aspect ratio ranging from 1 to about 2. Low aspect ratio thickeners are, for example, in powder form. Low aspect ratio thickeners can have average maximum dimensions ranging, for example, from about 0.1 μm to about 500 μm, such as from about 50 μm to about 150 μm. In other embodiments, the thickener has an average aspect ratio greater than about 2, for example, from about 2 to about 2,000. High aspect ratio thickeners are, for example, composed of rod- or wire-shaped particles. High aspect ratio thickeners can have average maximum dimensions ranging, for example, from about 0.1 mm to about 10 mm.

[0021] The thickener used functions as a viscosity modifier and helps resist or minimize the flow of the metal or metal alloy in the conductive paste layer. The thickener used may be an inorganic or organic material. The thickener does not dissolve the metal or metal alloy or form a solution of the metal or metal alloy, but rather remains in a solid state when mixed with the metal or metal alloy and becomes wetted by the metal or metal alloy. The thickener used is typically particulate, e.g., rod-shaped, wire-shaped, substantially spherical particles, or a mixture thereof, and the particle size determines how easily it can be homogenized with the metal or metal alloy to form a paste. Typically, thickeners with a larger surface area are better thickeners than those with a smaller surface area. The combination of thickener and metal or metal alloy is selected to provide the appropriate wetting properties of the thickener and the appropriate rheology or elastic modulus of the paste. The particle size and amount are selected so that the paste composition has a tan delta value of greater than about 1. The viscosity is selected to obtain a paste that behaves more like a liquid than like a solid, thereby ensuring flexibility of the final composite.

[0022] The thickener may be conductive or non-conductive, and if the thickener is conductive, it can increase the conductivity of the conductive composite 2, or it can reduce the amount of conductive paste 6 while maintaining the same level of conductivity.

[0023] In certain embodiments, the thickener comprises particles of an inorganic thickener, e.g., rod-shaped or wire-shaped, having an average aspect ratio of greater than about 2. That is, each particle has a length at least about twice its width. The average aspect ratio can be measured using a microscope.

[0024] In other embodiments, the thickener comprises inorganic thickener particles having an average aspect ratio of less than about 2, e.g., substantially spherical particles. That is, the length of each particle is at most about twice its width. In certain embodiments, the thickener comprises inorganic thickener particles that are substantially spherical and have an average particle size of about 0.1 μm to about 500 μm (about 100 nm to about 500,000 nm). Particles in this size range provide adequate surface area to function as a thickener when mixed with a metal or metal alloy to form a paste. In certain embodiments, the thickener comprises substantially spherical particles of an inorganic thickener having an average particle size of about 1 μm to about 25 μm, or about 25 μm to about 50 μm, or about 50 μm to about 75 μm, or about 75 μm to about 100 μm, or about 100 μm to about 150 μm, or about 150 μm to about 200 μm, or about 200 μm to about 250 μm, or about 250 μm to about 300 μm, or about 300 μm to about 350 μm, or about 350 μm to about 400 μm, or about 450 μm to about 500 μm. In other embodiments, the thickener comprises substantially spherical particles of an inorganic thickener having an average particle size of about 50 μm. In certain embodiments, the inorganic thickener particles have an average particle size of from about 0.1 μm to about 5 μm.

[0025] In one embodiment, the thickener is an inorganic thickener composed of rods or wires having an average aspect ratio greater than about 2 and a length of about 0.01 mm to about 10 mm. In specific embodiments, the length of each rod comprising the inorganic thickener is about 0.01 mm to about 0.5 mm, or about 0.05 mm to about 10 mm, or about 0.01 mm to about 10 mm, or about 0.01 mm to about 0.1 mm, or about 0.1 mm to about 1 mm, or about 1 mm to about 5 mm, or about 5 mm to about 10 mm. The use of rod- or wire-shaped conductive particles contributes more to the conductivity of the final composite than generally spherical conductive particles. The overall conductivity can be adjusted by either the amount of metal alloy or the amount of thickener.

[0026] In certain embodiments, the inorganic thickener is a powder having particles that are a mixture of rods or wires and substantially spherical particles, or a mixture of rods, wires, and substantially spherical particles.

[0027] In certain embodiments, the thickener comprises particles of an organic thickener having an average particle size of about 0.1 μm to about 500 μm. In certain embodiments, the thickener comprises particles of an organic thickener having an average particle size of about 1 μm to about 25 μm, or about 25 μm to about 50 μm, or about 50 μm to about 75 μm, or about 75 μm to about 100 μm, or about 100 μm to about 150 μm, or about 150 μm to about 200 μm, or about 200 μm to about 250 μm, or about 250 μm to about 300 μm, or about 300 μm to about 350 μm, or about 350 μm to about 400 μm, or about 450 μm to about 500 μm. In other embodiments, the thickener comprises particles of an organic thickener having an average particle size of about 50 μm to about 150 μm. In certain embodiments, the organic thickener has an average particle size of from about 0.1 μm to about 5 μm.

[0028] In embodiments where the paste contains a thickener, the thickener is used in an amount to provide the appropriate viscosity and / or to tailor the conductive properties of the paste and the final composite. The concentration of inorganic thickener in the paste may vary depending on the paste composition. The concentration of the organic thickener in the paste is suitably in the range of about 0.1% to about 20% by weight of the paste composition. The concentration of the organic thickener in the paste is suitably in the range of about 0.1% to about 40% by weight of the paste composition.

[0029] On a volume basis, the amount of thickener in the paste composition is suitably in the range of about 5% to about 50% of the volume of the paste. In certain embodiments, the amount of thickener is suitably in the range of about 5% to about 10%, or about 5% to about 15%, or about 10% to about 20%, or about 15% to about 25%, or about 20% to about 30%, or about 25% to about 35%, or about 30% to about 45% of the volume of the paste composition. These amounts are suitable for producing a paste having a tan delta value greater than 1, i.e., behaving more like a liquid than like a solid. This ensures flexibility of the final composite.

[0030] As described above, when a powder containing rod-shaped or wire-shaped particles is used as a thickener, the amount of thickener can be reduced. In the case of a rod-shaped or wire-shaped thickener, the amount of thickener in the paste is suitably in the range of about 2% to about 40% by volume of the paste. In certain embodiments, the amount of thickener is suitably in the range of about 2% to about 5%, or about 5% to about 10%, or about 10% to about 15%, or about 15% to about 20%, or about 20% to about 25%, or about 25% to about 30%, or about 30% to about 40% by volume of the paste composition.

[0031] According to the disclosed conductive composite, the content of solid conductive particles in the paste is increased. That is, suitable conductivity can be achieved without the requirement for particle packing greater than 45% by volume. However, in certain embodiments, particle packing greater than about 45% by volume may be employed for metal particles when the amount of metal present in the liquid phase is insufficient to form the desired level of electrical connection between the metal particles. Thus, particle packing levels in the paste can be about 45% by volume, e.g., from about 45% to about 80% by volume, as desired.

[0032] In certain embodiments, the thickener used in preparing the conductive composite is an organic thickener. Suitable organic thickeners include compounds with a melting temperature above about 60°C, which is a temperature that prevents the thickener from melting with the alloy before or during the preparation of the conductive composite. Examples of such compounds include maltol, phenol, naphthalene, 1-naphthol, 2-naphthol, 4-naphthol, and carbon, such as graphite and carbon black. If the organic thickener is a compound with a phenolic hydroxy group, the compound may react with the isocyanate group of a diisocyanate or polyisocyanate via the hydroxyl group, but the reaction rate is slower than the urea-forming reaction. The appropriate use of such compounds can adjust the properties of the final thickener. Alternatively, the organic thickener may be graphite or carbon particles.

[0033] In certain embodiments, the thickener is a single inorganic thickener or a combination of inorganic thickeners. Suitable inorganic thickeners include, for example, metal oxides such as titanium dioxide, zinc oxide, and nickel oxide; metals or metal alloys having a melting temperature above about 60°C; or ceramic materials. The metal or metal alloy is selected to have a melting temperature above about 60°C to avoid melting of the thickener before or during fabrication of the conductive composite. Suitable metals or metal alloys include silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, and combinations thereof.

[0034] The thickener may be a mixture of at least one organic thickener and at least one inorganic thickener, which may be used together to adjust the rheology or modulus of the paste.

[0035] In certain embodiments, the thickener comprises a powder of rod-shaped particles, wire-shaped particles, substantially spherical particles, or mixtures thereof, where the rod-shaped, wire-shaped, and substantially spherical particles include metals or metal alloys such as silver, copper, brass, nickel, stainless steel, steel, aluminum, carbon, coated carbon, titanium, tungsten, tin, zinc, and combinations thereof, metal oxides of nickel, ceramic materials, and combinations thereof. The substantially spherical particles have an average particle size of about 0.1 μm to about 500 μm (about 100 nm to about 500,000 nm), and the rod-shaped and wire-shaped particles have a length of about 0.01 mm to about 10 mm.

[0036] In one aspect, the layer of conductive paste includes a compatibilizer. The compatibilizer can include, for example, at least one of an organic compatibilizer, an inorganic compatibilizer, and a combination thereof. When the compatibilizer includes an organic compatibilizer, the organic compatibilizer can include, for example, a surfactant such as an ionic surfactant, a nonionic surfactant, and a combination thereof. When the compatibilizer includes an inorganic compatibilizer, the inorganic compatibilizer can include, for example, metal nanoparticles.

[0037] By using a compatibilizer, the processability (e.g., fluidity, ease of application, etc.) of the paste can be improved. Without wishing to be bound by theory, it is believed that when a compatibilizer is mixed with a low-melting-point metal or metal alloy, a compatibilizer adheres to the surfaces of particles or droplets of the low-melting-point metal or metal alloy. It is believed that a coating of the compatibilizer is formed, which reduces the surface energy of the low melting point metal or metal alloy, and, without wishing to be bound by theory, the compatibilizer forms a single or multiple layer coating on the droplets of the low melting point metal or metal alloy, which reduces or prevents oxidation of the metal or metal alloy, but does not form a shell as occurs with the use of acids.

[0038] In certain embodiments, the compatibilizers described are used to thicken the paste, i.e., to increase the viscosity of the paste.

[0039] In addition, if the paste has already oxidized, it can be reactivated by adding a compatibilizer. As used herein, "reactivation" refers to the process of adding additional compatibilizer to a mixture of a compatibilizer and a low-melting-point metal or metal alloy in a separated state and applying appropriate shear conditions, as described below, to restore the separated mixture to a homogeneous paste.

[0040] As described elsewhere herein, in embodiments where the paste includes particles of thickener, the compatibilizer of the present disclosure is believed to penetrate into the pores or voids between the particles of the thickener. As the compatibilizer penetrates the pores, it creates capillary pressure that holds the liquid metal or metal alloy between the particles, thereby binding the liquid metal or metal alloy to the thickener.

[0041] In certain embodiments, pastes used to prepare conductive composites include a low-melting point metal or metal alloy and a compatibilizer, with the weight ratio of the metal or metal alloy to the compatibilizer being about 5:1 to about 50:1, or about 10:1 to about 30:1, or about 15:1 to about 25:1, or about 20:1 to about 25:1. Thus, the amount of compatibilizer corresponds to a range of about 2% to about 20% by weight of the low-melting point metal or metal alloy. A particularly useful range of compatibilizer is about 4% to about 10% by weight, where weight percent represents the weight of the compatibilizer relative to the total weight of the paste. Phase separation should be avoided. At higher levels of compatibilizer, phase separation may occur, but this can be addressed using thickeners, as described elsewhere herein.

[0042] In certain embodiments, the compatibilizer comprises inorganic particles, such as, for example, metal nanoparticles, having an average particle size in any major linear dimension of less than about 100 nm, or less than about 90 nm, or less than about 80 nm, or less than about 70 nm, or less than about 60 nm, or less than about 50 nm, or less than about 40 nm, or less than about 30 nm, or less than about 20 nm. The particle sizes described may be measured, for example, by a Coulter Counter or a Masonry Counter. Measurements can be performed using a Multisizer. Suitable nanoparticles are made of metals that are insoluble, i.e., do not dissolve, in low-melting-point metals or metal alloys. Suitable metals for nanoparticles include those in which the solubility of gallium in the metal is less than about 5 mol% at room temperature. Suitable metals for the compatibilizer nanoparticles described include, for example, silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, and combinations thereof.

[0043] In certain embodiments, the compatibilizer is a nonionic amphiphilic compound or a mixture of nonionic amphiphilic compounds. Suitable nonionic amphiphilic compounds include fatty alcohol alkoxylates including fatty alcohol ethoxylates, alkylphenol alkoxylates including alkylphenol ethoxylates, fatty acid alkoxylates including fatty acid ethoxylates, alkoxylated amines including ethoxylated amines, fatty acid amides, polyoxyethylene-polyoxypropylene copolymers, fatty acid esters of polyhydroxy compounds, glycerol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, alkyl polyglucosides, fatty amine oxides, sulfoxides, organic phosphine oxides, and mixtures thereof.

[0044] In certain embodiments, the compatibilizer is an ionic compound. Suitable ionic amphiphilic compounds include anionic compounds and cationic compounds. Representative anionic compounds include alkyl sulfates, alkyl ether sulfates, alkyl sulfonates, alkyl ether sulfonates, alkyl phosphates, and alkyl carboxylates. Representative cationic compounds include quaternary ammonium compounds, monoalkylammonium salts, dialkylammonium salts, and trialkylammonium salts.

[0045] The choice and amount of anionic compound (or mixture thereof) and / or cationic compound (or mixture thereof) used to prepare the conductive paste layer depends on the elastomeric polymer used to prepare the conductive composite. The type and amount of anionic or cationic compound are selected so as not to cause degradation or depolymerization of the elastomeric polymer.

[0046] In certain embodiments, the compatibilizer is a surfactant.

[0047] In certain embodiments, the compatibilizer is a nonionic amphiphilic compound or a mixture of multiple nonionic amphiphilic compounds. Alkylphenol ethoxylates are particularly useful as nonionic amphiphilic compounds. Representative examples of alkylphenol ethoxylates include octylphenol ethoxylate, such as Triton® X-100 (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether having an average of 9.5 ethylene oxide units) and nonylphenol ethoxylate.

[0048] Other useful nonionic amphiphilic compounds include poloxamers, which are triblock copolymers of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO). For example, PLURONIC is a suitable nonionic amphiphilic compound.

[0049] The conductive composites described herein may include additional materials that impart other properties to the conductive composite. In one aspect, the conductive composite includes an additive that enhances thermal oxidative stability. When the conductive composite includes an additive that enhances thermal oxidative stability, the additive can include, for example, at least one of phosphates, iron oxides, phenols, antioxidants, metal passivators, and combinations thereof. A thermal oxidative stabilizer is a material or additive that enhances thermal oxidative stability. The thermal oxidative stabilizer can be included in the paste composition prior to fabrication of the conductive composite or added to the elastomeric polymer layer. Depending on the desired properties of the conductive composite and the environment in which the conductive composite will be used, phosphates, iron oxides, phenolic antioxidants, metal passivators, or combinations thereof can be used as the thermal oxidative stabilizer. The addition of a thermal oxidative stabilizer to the conductive composites of the present disclosure can extend the operating temperature range of the conductive composite. Suitable metal passivators include nitrates such as nitric acid, citrates such as citric acid, tungstates, molybdates, chromates, and mixtures thereof.

[0050] The paste can be prepared, for example, by mixing the low melting point metal or metal alloy, the compatibilizer, and any optional ingredients in a centrifugal planetary mixer or by shear mixing. The prepared paste can be stored and used at a later date.

[0051] In certain embodiments, the paste compositions of the present disclosure are useful for preparing conductive composites, and have a loss modulus (G") higher than a storage modulus (G'), i.e., a tan delta value greater than 1. Thus, the paste compositions of the present disclosure are useful for preparing conductive composites, as solids. The paste compositions of the present disclosure exhibit more liquid-like behavior than shear behavior as measured in accordance with ASTM D7175 using a dynamic shear rheometer. When the viscosity is increased, the viscosity is about 500 cP to about 100,000 cP at 1 Hz.

[0052] The thickness of each layer of the conductive composite 2 can be adjusted as needed to achieve desired properties in the final product. In one aspect, as shown in FIG. 2, the first layer of elastomeric polymer 4 has a first thickness 14. The second layer of elastomeric polymer 8 has a second thickness 12. The first thickness 14 and the second thickness 12 each range from about 0.01 mm to about 100 mm. In another aspect, the first thickness 14 and the second thickness 12 each range from about 0.1 mm to about 10 mm. For example, the first thickness 14 and the second thickness 12 each are about 1 mm. The first thickness 14 can be the same as or different from the second thickness 12. The layer of conductive fluorofluid has a third thickness 16, which is a thickness that is greater than or equal to the first thickness 14 and the second thickness 12. The third thickness 16 may be equal to or less than the thickness of at least one of the first thickness 14 and the second thickness 12. Alternatively, the third thickness 16 may be greater than the thickness of at least one of the first thickness 14 and the second thickness 12. In one aspect, the third thickness 16 is smaller than the combined thickness of the first thickness 14 and the second thickness 12. In another aspect, the third thickness 16 is smaller than the thickness of at least one of the first thickness 14 and the second thickness 12. For example, the first thickness 14 and the second thickness 12 are each about 1 mm, and the third thickness 16 is less than about 1 mm. The total thickness of the conductive composite 2 is, for example, within a range of about 0.03 mm to about 200 mm. In one aspect, the total thickness of the conductive composite 2 is, for example, within a range of about 0.1 mm to about 100 mm. In another aspect, the total thickness of the conductive composite 2 is, for example, within a range of about 0.5 mm to about 10 mm.

[0053] The conductive composite 2 may include one or more additional layers of elastic polymer and one or more additional layers of conductive paste. For example, the conductive composite may include three layers of elastic polymer and two layers of conductive paste, for a total of five layers.

[0054] In one aspect, the conductive composite 2 may be in the form of a laminate in which a continuous layer of conductive paste 6 is sandwiched between a first layer of elastic polymer 4 and a second layer of elastic polymer 8. The continuous layer of conductive paste 6 may be flat or curved. In one example, the length of the continuous layer of conductive paste 6 is sufficiently greater than the thickness of the continuous layer of conductive paste 6. In one aspect, the length of the continuous layer of conductive paste 6 is at least 5 times the thickness of the continuous layer of conductive paste 6. In another aspect, the length of the continuous layer of conductive paste 6 is at least 20 times the thickness of the continuous layer of conductive paste 6. In yet another aspect, the length of the continuous layer of conductive paste 6 is at least 50 times the thickness of the continuous layer of conductive paste 6. In another example, the length and width of the continuous layer of conductive paste 6 are sufficiently greater than the thickness of the continuous layer of conductive paste 6. In one aspect, the length and width of the continuous layer of conductive paste 6 are at least 5 times the thickness of the continuous layer of conductive paste 6. In another aspect, the length and width of the continuous layer of conductive paste 6 is at least 20 times the thickness of the continuous layer of conductive paste 6. In yet another aspect, the length and width of the continuous layer of conductive paste 6 is at least 50 times the thickness of the continuous layer of conductive paste 6.

[0055] The conductive composite 2 may be sealed at its edges around the layer of conductive paste 6 in some manner. In one aspect, the edges of the conductive composite 2 are sealed by contacting the first layer of elastic polymer 4 with the second layer of elastic polymer 8. For example, the first layer of elastic polymer 4 and the second layer of elastic polymer 8 are separated by a layer of conductive paste 6, but at the edges of the conductive composite 2 around the layer of conductive paste 6, the first layer of elastic polymer 4 and the second layer of elastic polymer 8 are in direct contact with each other. When cured, the second layer of elastic polymer 8 can bond to the first layer of elastic polymer 4 to form an effective encapsulation structure. The conductive composite 2 may be sealed around the layer of conductive paste. The edge length 18 in the first layer of elastic polymer 4 and the elastic polymer 8 In one aspect, the end length 18 is greater than at least one of the first thickness 14 and the second thickness 12.

[0056] The layer of conductive paste 6 described herein can impart conductivity to the conductive composite 2 without adding rigidity, and the high viscosity of the conductive paste layer prevents leakage of the conductive paste during coating or use. The description further includes a reinforcing mesh 10 in contact with the layer of conductive paste 6, as shown in Figures 2 and 3B. The reinforcing mesh 10 in contact with the layer of conductive paste 6 adjusts the flow characteristics, further reducing the possibility of leakage of the conductive paste 6, and can more reliably hold the conductive paste 6 inside the conductive composite 2.

[0057] The reinforcing mesh 10 may be freely movable relative to the first layer of elastomeric polymer 4 and the second layer of elastomeric polymer 8 so as not to impair the elasticity of the conductive composite 2. Alternatively, the reinforcing mesh 10 may be attached to either the first layer of elastomeric polymer 4 or the second layer of elastomeric polymer 8 to provide additional structural integrity.

[0058] The reinforcing mesh 10 may be conductive or non-conductive. If the reinforcing mesh 10 is conductive, the conductivity of the final conductive composite 2 may be increased. Alternatively, if the reinforcing mesh 10 is conductive, the amount of conductive paste 6 may be reduced while maintaining the same level of conductivity. Reducing the amount of conductive paste 6 in the conductive composite 2 further reduces the possibility of leakage of the conductive paste 6 and more reliably retains the conductive paste within the conductive composite 2. In one aspect, the conductive mesh has a thickness of about 1×10 3 In another aspect, the conductive mesh has a conductivity of more than S / m. The conductivity of is approximately 1×10 4 In yet another aspect, the conductive mesh The conductivity of is approximately 1×105 It is over S / m.

[0059] In one aspect, the reinforcing mesh 10 is a continuous layer of reinforcing mesh and is in contact with the continuous layer of conductive paste 6. In one example, the length of the continuous layer of reinforcing mesh is sufficiently greater than the thickness of the continuous layer of reinforcing mesh. In one aspect, the length of the continuous layer of reinforcing mesh is at least 5 times the thickness of the continuous layer of reinforcing mesh. In another aspect, the length of the continuous layer of reinforcing mesh is at least 20 times the thickness of the continuous layer of reinforcing mesh. In yet another aspect, the length of the continuous layer of reinforcing mesh is at least 50 times the thickness of the continuous layer of reinforcing mesh. In another example, the length and width of the continuous layer of reinforcing mesh are sufficiently greater than the thickness of the continuous layer of reinforcing mesh. In one aspect, the length and width of the continuous layer of reinforcing mesh are at least 5 times the thickness of the continuous layer of reinforcing mesh. In another aspect, the length and width of the continuous layer of reinforcing mesh are at least 20 times the thickness of the continuous layer of reinforcing mesh. In yet another aspect, the length and width of the continuous layer of reinforcing mesh are at least 50 times the thickness of the continuous layer of reinforcing mesh. The length and width of the reinforcing mesh 10 may be greater than, the same as, or smaller than the continuous layer of conductive paste 6 .

[0060] Additionally, the conductive composite 2 may be a laminate structure in which a continuous layer of conductive paste 6 and a continuous layer of reinforcing mesh 10 are sandwiched between a first layer of elastic polymer 4 and a second layer of elastic polymer 8, and such a laminate structure allows the continuous layer of conductive paste 6 and the continuous layer of reinforcing mesh 10 to be placed at the same time.

[0061] The reinforcing mesh 10 may be, for example, a knit fabric, a woven fabric, or the like. The fabric may be a non-conductive fabric, a conductive fabric, or a combination thereof. If the fabric is conductive, it can improve the conductivity of the final conductive composite 2. It can be increased.

[0062] Examples of non-conductive fabrics include polyether-polyurea copolymers, latex, polyparaphenylene terephthalamide, aramid, nylon, polyester, and combinations thereof, although any fabric may be used that is chemically suitable for use with the conductive paste 6. Non-conductive fabrics can be made conductive by coating them with a conductive material.

[0063] Conductive fabrics include, for example, conductive filaments, coated non-conductive fabrics, and combinations thereof. Examples of conductive filaments include silver filaments, copper filaments, brass filaments, nickel filaments, stainless steel filaments, steel filaments, aluminum filaments, carbon filaments, coated carbon filaments, titanium filaments, tungsten filaments, tin filaments, zinc filaments, and combinations thereof. Examples of coated non-conductive fabrics include metal-coated polyether-polyurea copolymers, metal-coated latex, metal-coated polyparaphenylene terephthalamide, metal-coated aramid, metal-coated nylon, metal-coated polyester, carbon-coated polyether-polyurea copolymers, carbon-coated latex, carbon-coated polyparaphenylene terephthalamide, carbon-coated aramid, carbon-coated nylon, carbon-coated polyester, and combinations thereof.

[0064] In certain embodiments, the conductive composite 2 described herein has a minimum sheet resistance of less than about 100 Ω / □. The sheet resistance of a particular conductive composite depends on its end use. For example, when used to shield electronic components from electromagnetic radiation, e.g., to minimize electromagnetic interference that can adversely affect or damage sensitive electronic components, a minimum sheet resistance of less than about 100 Ω / □ is desirable for the conductive composite. Sheet resistance can be measured using a four-point probe.

[0065] In certain embodiments, the conductive composite 2 described herein exhibits an elongation to break of about 10% or greater. In other embodiments, the conductive composite 2 described herein exhibits an elongation to break of about 25% or greater. In yet other embodiments, the conductive composite 2 described herein exhibits an elongation to break of about 50% or greater. Elongation to break is a value that represents the percentage of length that a material can extend to when subjected to a tensile force before breaking. Elongation to break is expressed as a percentage of the original length.

[0066] In certain embodiments, the conductive composite 2 described herein exhibits a tensile strength of about 3 MPa or greater.

[0067] In certain embodiments, the conductive composite 2 described herein has a density of less than about 7 g / mL, less than about 6 g / mL, less than about 5 g / mL, or less than about 4 g / mL. In certain embodiments, the conductive composite has a density between about 2 g / mL and about 10 g / mL. In other embodiments, the conductive composite has a density between about 10 g / mL and about 20 g / mL. In still other embodiments, the conductive composite has a density between about 1 g / mL and about 5 g / mL, or between about 3 g / mL and about 8 g / mL. This parameter can be easily measured by determining the mass of a known volume or measuring the volume of water displaced by a known mass.

[0068] In certain embodiments, the conductive composite 2 described herein has a maximum bulk conductivity of about 5×10 at 20° C. 5 S / m.

[0069] In certain embodiments, the conductive composite is flexible. The conductive composite has a tensile strength of about 3 MPa or greater. In certain embodiments, the conductive composite is flexible and exhibits a tensile strength of about 3 MPa or greater.

[0070] The present disclosure also provides products, items, and structures including a substrate laminated with a layer of the conductive composite of the present disclosure. These products, items, and structures can be constructed by heating the thermoplastic or thermoset conductive composite of the present disclosure and disposing it on a substrate. In certain embodiments, the conductive composite is an aircraft component, such as part or all of at least one of an aircraft wing and fuselage. In certain embodiments, the conductive composite is at least one of a seal and a gasket.

[0071] 3A, 3B, and 3C, the conductive composite 2 of the present disclosure can be made by forming a first layer of elastic polymer 4 (see FIG. 3A) and then forming a layer of conductive paste 6 (see FIG. 3B) on the first layer of elastic polymer 4. Before or after forming the layer of conductive paste 6, the layer of conductive paste 6 is reinforced with a reinforcing mesh 10. Then, a second layer of elastic polymer 8 is formed on the layer of conductive paste 6 (see FIG. 3C).

[0072] In one aspect, forming the first layer of elastomeric polymer includes curing the first layer of elastomeric polymer. Curing the first layer of elastomeric polymer can include curing the first layer of elastomeric polymer.

[0073] In certain embodiments, forming the conductive paste layer includes mixing a metal or metal alloy having a melting temperature of less than about 60° C. with a thickener. In other embodiments, forming the conductive paste layer includes mixing a metal or metal alloy having a melting temperature of less than about 60° C. with a thickener and a compatibilizer. In other embodiments, forming the conductive paste layer includes mixing a metal or metal alloy having a melting temperature of less than about 60° C. with a thickener, a thermo-oxidative stability enhancing additive, and, if necessary, a compatibilizer. In one aspect, forming the conductive paste layer includes preparing the conductive paste using shear mixing. Shear mixing is performed at a rotational speed ranging from about 25 rpm to about 2,000 rpm, e.g., from about 25 rpm to about 125 rpm. In another aspect, forming the conductive paste layer includes impregnating the reinforcing mesh 10 with the conductive paste.

[0074] In certain embodiments, forming the second layer of elastomeric polymer includes curing the second layer of elastomeric polymer. Curing the second layer of elastomeric polymer can include bonding the second layer of elastomeric polymer to the first layer of elastomeric polymer.

[0075] The described method may include trimming the conductive composite around the layer of conductive paste after forming the second layer of elastic polymer, hi one aspect, the trimming is performed to leave an edge length around the layer of conductive paste.

[0076] Illustratively, the conductive composite of the present disclosure may be formed by applying a layer of conductive paste to the surface of a cured or semi-cured first elastomeric polymer, followed by a layer of a second elastomeric polymer thereon.

[0077] In another example, the conductive composite of the present disclosure is formed by spreading a conductive paste on a non-stick surface, applying an uncured elastomeric polymer over the paste, and then curing the elastomeric polymer. The conductive composite can then be easily removed from the non-stick surface by peeling it off. After removal, if necessary or desired, a layer of cured or uncured elastomeric polymer may be added to the conductive paste and cured as needed to form a sandwich or laminate structure.

[0078] The laminate composite of the present disclosure can be formed by applying a layer of conductive paste to a surface of a first elastomeric polymer, and then overlaying the conductive paste layer with a layer of a second elastomeric polymer, which can be the same polymer as the first elastomeric polymer or a different polymer. The addition of the second elastomeric polymer layer can encapsulate the conductive paste layer.

[0079] Laminated composites of the present disclosure can also be formed by spreading a conductive paste onto a non-stick surface, applying an uncured elastomeric polymer over the paste, and then curing the elastomeric polymer. The conductive composite can then be easily removed from the non-stick surface by peeling it away from the non-stick surface. Optionally, if desired, a second elastomeric polymer (which may be the same or a different polymer than the first elastomeric polymer) can be applied over the conductive paste layer. The addition of the second elastomeric polymer layer can seal the conductive paste layer.

[0080] The non-stick surface may be any suitable non-stick material, examples of which include polytetrafluoroethylene, anodized aluminum, ceramic materials, and enameled cast iron.

[0081] The present disclosure also provides products, items, and structures that include a substrate having a layer of conductive composite deposited thereon, and in certain embodiments, provides a flexible conductive composite. Such products, items, and structures can be constructed by heating a thermoplastic or thermoset conductive composite of the present disclosure and disposing it on a substrate.

[0082] The conductive paste composition can be prepared by mixing a low-melting-point metal or metal alloy with a compatibilizer and thoroughly mixing the mixture to form a homogeneous paste. The mixing process can be performed using a shear mixer at a rotation speed of about 25 rpm to about 2,500 rpm. In certain embodiments, the shear mixing to prepare the paste composition is performed at a rotation speed of about 25 rpm to about 125 rpm, or about 125 rpm to about 250 rpm, or about 250 rpm to about 400 rpm, or about 400 rpm to about 700 rpm, or about 700 rpm to about 1,500 rpm, or about 1,500 rpm to about 2,500 rpm. Alternatively, the mixing process can be performed using a planetary mixer. The prepared paste can be stored for later use.

[0083] Additionally, the elastic polymer layer may be treated on the surface facing the conductive paste layer to improve wettability with the liquid metal. Such treatments include ultraviolet treatment, plasma treatment, or corona discharge treatment. Additionally, the elastic polymer layer may be coated with a surfactant on the surface facing the conductive paste layer to improve wettability.

[0084] The following describes examples in which experiments were conducted to demonstrate other features and properties of the conductive composites described herein. [Example]

[0085] Preparation of conductive paste: 4.93 g of nonionic surfactant (Triton X100) was added to 49.63 g of liquid gallium alloy metal, and the mixture was mixed at 2,300 rpm for 2 minutes to form a smooth paste. A soft, flowable paste was obtained.

[0086] Preparation of Impregnated Reinforcing Mesh: The prepared fluid conductive paste was spread with a paint brush to impregnate the silver knit.

[0087] Conductive composite laminate preparation: Liquid silicone rubber NuSil R21-2615 This is a two-component, clear silicone system that can be rapidly thermally cured by mixing Part A and Part B in a 1:1 ratio. For the experiment, equal parts were weighed into a Flacktek mixer container and mixed at 2,300 rpm for approximately 1 minute. The resulting homogeneous resin was poured onto a panel with a Mylar release film and formed into a 30-mil thick film using a glass rod. An impregnated silver braided reinforcing mesh was then placed on top of the NuSil film, and the remaining NuSil mixture was poured over the reinforcing mesh and spread evenly using a glass rod. The top panel, Mylar release side down, was placed on top of the resin, and a vent sheet was placed over the panel. After installing a vacuum connector inside the vacuum bag, the bag was sealed and a 0.5-inch slit was made through which a vacuum hose could be connected. After sealing the system, the vacuum pump was immediately started to maintain a negative pressure of -25 inches Hg. The entire vacuum bag system was placed on a 60°C hot plate for a rapid heat cure of approximately 40 minutes. After 1 hour, the conductive composite was removed from the system. The resulting composite had a thickness of approximately 0.05 inches. [Example]

[0088] Preparation of conductive paste: 4.93 g of a nonionic surfactant (Triton X100) was added to 49.63 g of gallium alloy liquid metal and mixed at 2,300 rpm for 2 minutes to obtain a smooth, fluid paste.

[0089] Preparation of Impregnated Reinforcing Mesh: The prepared fluid conductive paste was spread with a paint brush and allowed to penetrate the Chloroban fabric.

[0090] Conductive composite laminate preparation: Liquid silicone rubber NuSil R21-2615 This is a two-component, clear silicone system that can be rapidly thermally cured by mixing Part A and Part B in a 1:1 ratio. For the experiment, equal parts were weighed into a Flacktek mixer container and mixed at 2,300 rpm for approximately 1 minute. The resulting homogeneous resin was poured onto a panel with a Mylar release film and formed into a 30-mil thick film using a glass rod. An impregnated reinforcing mesh (Chloroban fabric) was then placed on top of the NuSil film, and the remaining NuSil mixture was poured onto the fabric and spread evenly using a glass rod. The top panel, Mylar release side down, was placed on top of the resin, and a vent sheet was placed over the panel. After installing a vacuum connector inside the vacuum bag, the bag was sealed and a 0.5-inch slit was made through which a vacuum hose could be connected. After sealing the installed system, the vacuum pump was immediately started and maintained at a negative pressure of -25 inches Hg. The entire vacuum bag system was placed on a 60°C hot plate for a rapid heat cure of approximately 40 minutes. After 1 hour, the conductive composite was removed from the system. The resulting composite had a thickness of approximately 0.03 inches.

[0091] Table 1 shows the mechanical properties of Example 1 of the present description. Measurements were made before and after aging in air at 100° C. for 50 d. [Table 1]

[0092] Table 2 shows the electrical conductivity properties of Examples 1 and 2 described herein. [Table 2]

[0093] Embodiments of the present disclosure may be described with reference to aircraft manufacturing and service method 1000 shown in Figure 4 and aircraft 1002 shown in Figure 5. As a pre-production step, aircraft manufacturing and service method 1000 includes specification and design 1004 of aircraft 1002 and material procurement 1006. During production, manufacturing of parts and subassemblies for aircraft 1002 1008 and system integration 1010. The aircraft 1002 then undergoes, for example, certification and delivery 1012 and enters service 1014. While in service, the aircraft 1002 undergoes a routine maintenance and service schedule 1016, which may include modifications, reconfigurations, retrofits, etc.

[0094] Each step of method 1000 may be performed or carried out by a system integrator, a third party, and / or an operator (e.g., a customer). Note that a system integrator may include, but is not limited to, any number of aircraft manufacturers and major system subcontractors. A third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers. An operator may include, but is not limited to, an airline, a leasing company, a military entity, a service provider, or a third party. It may also be a service organization.

[0095] The conductive composites of the present disclosure may be employed at any one or more stages in a method of manufacture and use 1000, including specification and design 1004 of the aircraft 1002, material procurement 1006, component and subassembly manufacturing 1008, system integration 1010, certification and delivery 1012, aircraft entry into service 1014, and routine maintenance and service 1016.

[0096] 5 , the aircraft 1002 produced by the exemplary method 1000 includes an airframe 1018 with a number of systems 1020 and an interior 1022. Examples of the number of systems 1020 include one or more of a propulsion system 1024, an electrical system 1026, a hydraulic system 1028, and an environmental system 1030, as well as any number of other systems. The conductive composites of the present disclosure may be employed in any of the systems of the aircraft 1002 described above. [Note]

[0097] Furthermore, the present disclosure also encompasses embodiments according to the following appendices.

[0098] 1. A first layer of elastomeric polymer (4), a layer of conductive paste (6) on the first layer of elastic polymer (4); a second layer of elastic polymer (8) on said layer of conductive paste (6); A conductive composite (2) comprising: a reinforcing mesh (10) in contact with the layer of conductive paste (6).

[0099] 2. The conductive composite (2) of claim 1, wherein the layer of conductive paste (6) comprises a metal or metal alloy having a melting temperature of less than about 60°C and a thickener.

[0100] 3. The conductive composite (2) of claim 2, wherein the metal or metal alloy comprises at least one of gallium, mercury, indium, tin, bismuth, phosphorus, lead, zinc, cadmium, antimony, and combinations thereof.

[0101] 4. The conductive composite (2) according to claim 2 or 3, wherein the thickener comprises at least one of an organic thickener, an inorganic thickener, and a combination thereof.

[0102] 5. The conductive composite (2) according to any one of Appendices 2 to 4, wherein the thickener comprises an organic thickener, and the organic thickener comprises at least one of maltose, carbon, and combinations thereof.

[0103] 6. The conductive composite (2) according to any one of Appendices 2 to 4, wherein the thickener comprises an inorganic thickener, and the inorganic thickener comprises at least one of silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, and combinations thereof.

[0104] 7. The conductive composite (2) according to any one of Appendices 2 to 6, wherein the thickener has an average aspect ratio in the range of 1 to about 2.

[0105] 8. The conductive composite (2) according to any one of Appendices 2 to 7, wherein the thickener has an average aspect ratio in the range of 1 to 2 and an average largest dimension in the range of about 0.1 μm to about 500 μm.

[0106] 9. The conductive composite (2) according to any one of Appendices 2 to 8, wherein the thickener has an average aspect ratio in the range of 1 to about 2 and an average maximum dimension in the range of about 50 μm to about 150 μm.

[0107] 10. The conductive composite (2) according to any one of claims 2 to 6, wherein the thickener has an average aspect ratio of greater than about 2.

[0108] 11. The conductive composite (2) according to any one of Appendices 2 to 6, wherein the thickener has an average aspect ratio in the range of about 2 to about 2,000.

[0109] 12. The conductive composite (2) according to any one of Appendices 2 to 6, wherein the thickener has an average aspect ratio in the range of about 2 to about 2,000 and an average maximum dimension in the range of about 0.1 mm to about 10 mm.

[0110] 13. The conductive composite (2) according to any one of appendices 1 to 12, wherein the layer of conductive paste (6) further comprises a compatibilizer.

[0111] 14. The conductive composite (2) according to any one of Appendices 1 to 13, wherein the layer of conductive paste (6) further comprises a compatibilizer, and the compatibilizer comprises at least one of an organic compatibilizer, an inorganic compatibilizer, and a combination thereof.

[0112] 15. The conductive composite (2) according to any one of Appendices 1 to 14, wherein the layer of the conductive paste (6) further comprises an organic compatibilizer, and the organic compatibilizer comprises a surfactant.

[0113] 16. The conductive composite (2) according to any one of Appendices 1 to 15, wherein the layer of the conductive paste (6) further comprises an organic compatibilizer, and the organic compatibilizer comprises at least one of an ionic surfactant, a non-ionic surfactant, and a combination thereof.

[0114] 17. The conductive composite (2) according to any one of appendices 1 to 16, further comprising an additive that enhances thermo-oxidative stability.

[0115] 18. The conductive composite (2) according to any one of Appendices 1 to 17, further comprising an additive that enhances thermal oxidative stability, the additive comprising at least one of a phosphate, an iron oxide, a phenol, an antioxidant, a metal passivator, and combinations thereof.

[0116] 19. The conductive composite (2) of any one of claims 1 to 18, wherein the first layer of elastic polymer (4) comprises at least one of a thermoplastic polymer, a thermosetting polymer, and combinations thereof.

[0117] 20. The conductive composite (2) of any one of claims 1 to 19, wherein the first layer of elastomeric polymer (4) comprises at least one of siloxane, fluorosiloxane, perfluoropolyether, polybutadiene, polyester, polycarbonate, polyurethane, polyurea, polyurethaneurea, epoxy, acrylate, natural rubber, butyl rubber, polyacrylonitrile, ethylene propylene diene monomer (EPDM) rubber, and combinations thereof.

[0118] 21. The conductive composite (2) of any one of claims 1 to 20, wherein the second layer of elastic polymer (8) comprises at least one of a thermoplastic polymer, a thermosetting polymer, and combinations thereof.

[0119] 22. The conductive composite (2) of any one of Appendices 1 to 21, wherein the second layer of elastomeric polymer (8) comprises at least one of siloxane, fluorosiloxane, perfluoropolyether, polybutadiene, polyester, polycarbonate, polyurethane, polyurea, polyurethaneurea, epoxy, acrylate, natural rubber, butyl rubber, polyacrylonitrile, ethylene propylene diene monomer (EPDM) rubber, and combinations thereof.

[0120] 23. The conductive composite (2) according to any one of appendices 1 to 22, wherein the first layer of elastic polymer (4) has a thickness in the range of about 0.01 mm to about 100 mm.

[0121] 24. The conductive composite (2) according to any one of appendices 1 to 23, wherein the first layer of elastic polymer (4) has a thickness in the range of about 0.1 mm to about 10 mm.

[0122] 25. The second layer of the elastic polymer (8) has a thickness in the range of about 0.01 mm to about 100 mm. The conductive composite material (2) according to any one of Appendices 1 to 24, having a thickness of

[0123] 26. The conductive composite (2) according to any one of appendices 1 to 25, wherein the second layer of elastic polymer (8) has a thickness in the range of about 0.1 mm to about 10 mm.

[0124] 27. A conductive composite (2) according to claim 1, wherein the thickness of the layer of conductive paste is at least one of the thickness of the first layer of the elastic polymer (4) or the thickness of the second layer of the elastic polymer (8) or less.

[0125] 28. A conductive composite (2) according to claim 1, wherein the thickness of the layer of conductive paste is at least one of: greater than the thickness of the first layer of the elastic polymer (4) or greater than the thickness of the second layer of the elastic polymer (8).

[0126] 29. A conductive composite (2) according to claim 1, wherein the thickness of the layer of conductive paste is greater than the combined thickness of the first layer of elastic polymer (4) and the second layer of elastic polymer (8).

[0127] 30. The conductive composite (2) according to any one of appendices 1 to 29, wherein the layer of conductive paste (6) is homogeneous.

[0128] 31. The conductive composite (2) according to any one of appendices 1 to 29, wherein the layer of conductive paste (6) is heterogeneous.

[0129] 32. The conductive composite (2) according to any one of claims 1 to 31, wherein the reinforcing mesh (10) comprises a fabric.

[0130] 33. The conductive composite (2) of any one of claims 1 to 33, wherein the reinforcing mesh (10) comprises at least one of a knitted fabric, a woven fabric, and a combination thereof.

[0131] 34. The conductive composite (2) of any one of claims 1 to 34, wherein the reinforcing mesh (10) comprises at least one of a non-conductive fabric, a conductive fabric, and a combination thereof.

[0132] 35. The conductive composite (2) of any one of Appendices 1 to 34, wherein the reinforcing mesh (10) comprises a non-conductive fabric, the non-conductive fabric comprising at least one of polyether-polyurea copolymer, latex, polyparaphenylene terephthalamide, aramid, nylon, polyester, and combinations thereof.

[0133] 36. The conductive composite (2) of any one of Appendices 1 to 34, wherein the reinforcing mesh (10) comprises a conductive fabric, the conductive fabric comprising at least one of conductive filaments, coated non-conductive fabric, and combinations thereof.

[0134] 37. Any of clauses 1-34, wherein the reinforcing mesh (10) comprises a conductive fabric, the conductive fabric comprising conductive filaments, the conductive filaments comprising at least one of silver filaments, copper filaments, brass filaments, nickel filaments, stainless steel filaments, steel filaments, aluminum filaments, carbon filaments, coated carbon filaments, titanium filaments, tungsten filaments, tin filaments, zinc filaments, and combinations thereof. The conductive composite material (2) described above.

[0135] 38. The conductive composite (2) according to any one of Appendices 1 to 34, wherein the reinforcing mesh (10) comprises a conductive fabric, the conductive fabric comprising a coated non-conductive fabric, the coated non-conductive fabric comprising at least one of metal-coated polyether-polyurea copolymer, metal-coated latex, metal-coated polyparaphenylene terephthalamide, metal-coated aramid, metal-coated nylon, metal-coated polyester, carbon-coated polyether-polyurea copolymer, carbon-coated latex, carbon-coated polyparaphenylene terephthalamide, carbon-coated aramid, carbon-coated nylon, carbon-coated polyester, and combinations thereof.

[0136] 39. The conductive composite (2) according to any one of appendices 1 to 38, wherein the conductive composite (2) exhibits a minimum sheet resistance of less than about 100 Ω / □.

[0137] 40. The conductive composite (2) according to any one of Appendices 1 to 39, wherein the conductive composite (2) exhibits a breaking elongation of about 10% or more.

[0138] 41. The conductive composite (2) according to any one of Appendices 1 to 40, wherein the conductive composite (2) exhibits a breaking elongation of about 15% or more.

[0139] 42. The conductive composite (2) according to any one of appendices 1 to 40, wherein the conductive composite (2) exhibits a breaking elongation of about 50% or more.

[0140] 43. The conductive composite (2) according to any one of Appendices 1 to 42, wherein the conductive composite (2) exhibits a tensile strength of about 3 MPa or more.

[0141] 44. The conductive composite (2) according to any one of Appendices 1 to 43, wherein the conductive composite (2) has a density of less than about 7 g / mL.

[0142] 45. The conductive composite (2) according to any one of Appendices 1 to 44, wherein the conductive composite (2) has a density of less than about 6 g / mL.

[0143] 46. ​​The conductive composite (2) according to any one of Appendices 1 to 45, wherein the conductive composite (2) has a density of less than about 5 g / mL.

[0144] 47. The conductive composite (2) according to any one of Appendices 1 to 46, wherein the conductive composite (2) has a density of less than about 4 g / mL.

[0145] 48. The conductive composite (2) according to any one of Appendices 1 to 47, wherein the conductive paste has a loss modulus (G") higher than a storage modulus (G').

[0146] 49. The conductive composite (2) according to any one of appendices 1 to 48, which is part of an aircraft.

[0147] 50. The conductive composite (2) according to any one of appendices 1 to 49, which is at least a part of at least one of an aircraft wing and fuselage.

[0148] 51. The conductive composite (2) according to any one of appendices 1 to 49, which is at least one of a seal and a gasket.

[0149] 52. A method for making a conductive composite, comprising: forming a first layer of an elastomeric polymer; forming a layer of conductive paste reinforced with a reinforcing mesh on the first layer of resilient polymer; forming a second layer of a resilient polymer over the layer of conductive paste.

[0150] 53. The method of claim 52, wherein forming the first layer of elastomeric polymer includes curing the first layer of elastomeric polymer.

[0151] 54. The method of claim 52 or 53, wherein the step of forming the layer of conductive paste includes mixing a thickener with a metal or metal alloy having a melting temperature of less than about 60°C.

[0152] 55. The method of any of claims 52-54, wherein the step of forming the layer of conductive paste includes mixing a metal or metal alloy having a melting temperature of less than about 60°C with a thickener and a compatibilizer.

[0153] 56. The method of any of claims 52-55, wherein the step of forming the layer of conductive paste includes mixing a metal or metal alloy having a melting temperature of less than about 60°C with a thickener and an additive that enhances thermal oxidative stability.

[0154] 57. The method of any of claims 52-56, wherein the step of forming the layer of conductive paste includes preparing the conductive paste using shear mixing.

[0155] 58. The method of any of claims 52 to 57, wherein the step of forming the conductive paste layer includes preparing the conductive paste using shear mixing, and the shear mixing is performed at a rotational speed in the range of about 25 rpm to about 2,000 rpm.

[0156] 59. A method according to any one of claims 52 to 58, wherein the step of forming the conductive paste layer includes preparing the conductive paste using shear mixing, and the shear mixing is performed at a rotational speed in the range of about 25 rpm to 125 rpm.

[0157] 60. The method of any one of claims 52 to 59, wherein the step of forming the layer of conductive paste includes impregnating the reinforcing mesh with the layer of conductive paste.

[0158] 61. The method of any one of claims 52-60, wherein forming the second layer of elastomeric polymer includes curing the second layer of elastomeric polymer.

[0159] 62. The method of claim 61, wherein the step of curing the second layer of elastomeric polymer includes bonding the second layer of elastomeric polymer to the first layer of elastomeric polymer.

[0160] 63. The method of any one of claims 52 to 62, wherein the first layer of elastomeric polymer and the second layer of elastomeric polymer encapsulate the layer of conductive paste.

[0161] 64. The method of any of claims 52-63, further comprising trimming the conductive composite around the layer of conductive paste.

[0162] 65. Trimming the conductive composite around the layer of conductive paste. 65. The method according to any one of appendices 52 to 64, wherein the step is carried out so as to leave a peripheral edge length of the conductive paste layer.

[0163] 66. The method of any one of appendixes 65-66, wherein the end length is greater than or equal to at least one of the thickness of the first layer of elastic polymer and the thickness of the second layer of elastic polymer.

[0164] While the conductive composites and methods for making conductive composites of the present disclosure have been shown and described in various embodiments, modifications will occur to those skilled in the art upon reading this specification, and the present disclosure is intended to include all such modifications and is limited only by the scope of the claims.

Claims

1. a first layer of an elastomeric polymer; a layer of conductive paste on the first layer of elastomeric polymer; a second layer of elastomeric polymer on the layer of conductive paste; a reinforcing mesh in contact with the layer of conductive paste.

2. 10. The conductive composite of claim 1, wherein the layer of conductive paste comprises a metal or metal alloy having a melting temperature of less than about 60°C and a thickener.

3. 3. The conductive composite of claim 2, wherein the metal or metal alloy comprises at least one of gallium, mercury, indium, tin, bismuth, phosphorus, lead, zinc, cadmium, antimony, and combinations thereof.

4. 4. The conductive composite of claim 2 or 3, wherein the thickener comprises at least one of an organic thickener, an inorganic thickener, and a combination thereof.

5. 5. The conductive composite of claim 2, wherein the thickener has an average aspect ratio in the range of 1 to 2 and an average largest dimension in the range of about 0.1 μm to about 500 μm.

6. 5. The conductive composite of claim 2, wherein the thickener has an average aspect ratio in the range of about 2 to about 2,000 and an average largest dimension in the range of about 0.1 mm to about 10 mm.

7. 10. The conductive composite of claim 1, wherein the layer of conductive paste further comprises a compatibilizer, the compatibilizer comprising at least one of an organic compatibilizer, an inorganic compatibilizer, and combinations thereof.

8. 10. The conductive composite of claim 1, further comprising a thermo-oxidative stability enhancing additive, said additive comprising at least one of a phosphate, an iron oxide, a phenol, an antioxidant, a metal passivator, and combinations thereof.

9. The conductive composite of claim 1 , wherein the first layer of elastic polymer comprises at least one of a thermoplastic polymer, a thermoset polymer, and combinations thereof.

10. The conductive composite of claim 1 , wherein the second layer of elastic polymer comprises at least one of a thermoplastic polymer, a thermoset polymer, and combinations thereof.

11. The conductive composite of claim 1 , wherein the reinforcing mesh comprises at least one of a knitted fabric, a woven fabric, and combinations thereof.

12. 10. The conductive composite of claim 1, wherein the reinforcing mesh comprises a conductive fabric, the conductive fabric comprising at least one of a conductive filament, a coated non-conductive fabric, and combinations thereof.

13. 10. The conductive composite of claim 1, which is part of an aircraft.

14. 10. The conductive composite of claim 1, wherein the conductive composite is at least a portion of at least one of an aircraft wing, fuselage, seal, and gasket.

15. 1. A method for making a conductive composite, comprising: forming a first layer of an elastomeric polymer; forming a layer of conductive paste reinforced with a reinforcing mesh on the first layer of resilient polymer; forming a second layer of a resilient polymer over the layer of conductive paste.

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