Conductive composite materials and methods of making conductive composite materials

Abstract

The present invention relates to a conductive composite material and a method for manufacturing the conductive composite material. The conductive composite material includes a first elastic polymer layer, a conductive paste layer on the first elastic polymer layer, and a second elastic polymer layer on the conductive paste layer. A reinforcing mesh contacts the conductive paste layer.

Description

Technical Field

[0001] The present application relates to a conductive composite material and a method for manufacturing the conductive composite material, belonging to the technical field of conductive composite materials. Background Art

[0002] Broadly defined, a conductive composite is any composite material that exhibits significant electrical or thermal conductivity. Such conductive composites have a wide range of uses in fields such as telecommunications, power generation and distribution, defense, aerospace, medicine, and other areas.

[0003] Conductive composite materials are typically made by combining polymeric materials with solid conductive particles and / or their properties are achieved by combining polymeric materials with solid conductive particles. To achieve sufficient conductivity, i.e., to achieve percolation, high particle loadings, typically exceeding 45% by volume, are typically required. Polymers used at these particle loading levels are typically rigid materials. Consequently, these particle loading levels result in conductive films and coatings having properties such as elongation at break, tensile strength, and thermal stability that make them unsuitable or difficult to use.

[0004] Therefore, those skilled in the art continue to conduct research and development in the field of conductive composite materials. Summary of the Invention

[0005] In one embodiment, the conductive composite material includes a first elastic polymer layer, a conductive paste layer on the first elastic polymer layer, and a second elastic polymer layer on the conductive paste layer; the reinforcement mesh is in contact with the conductive paste layer.

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

[0007] Other embodiments of the disclosed conductive composites and methods for making the conductive composites will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view of an exemplary conductive composite material according to an exemplary embodiment of the present specification.

[0009] Figure 2 It is taken along lines AA and BB Figure 1 A cross-sectional perspective view of an exemplary conductive composite material.

[0010] Figures 3A to 3C is shown for manufacturing Figure 1 and 2 A perspective view of the steps of an exemplary conductive composite material.

[0011] Figure 4 It is a flow chart of the aircraft manufacturing and maintenance methods.

[0012] Figure 5 This is a block diagram of the aircraft. DETAILED DESCRIPTION

[0013] like Figure 1 and 2 As shown, the conductive composite material 2 includes a first elastic polymer layer 4 , a conductive paste layer 6 on the first elastic polymer layer 4 , a second elastic polymer layer 8 on the conductive paste layer 6 , and a reinforcing mesh 10 in contact with the conductive paste layer 6 .

[0014] An elastomeric polymer is a polymer that exhibits elasticity at high strain levels. In one aspect, an elastomeric polymer of the present disclosure is a polymer that exhibits an elongation at break greater than about 50%. In another aspect, an elastomeric polymer of the present disclosure is a polymer that exhibits an elongation at break greater than about 100%. In yet another aspect, an elastomeric polymer of the present disclosure is a polymer that exhibits an elongation at break greater than about 200%. Elongation at break is measured as the percentage of strain to which a material breaks when a tensile force is applied. Elongation at break is expressed as a percentage of the original length.

[0015] In one aspect, the elastic polymer of the present description is an electrical insulator. In one aspect, the elastic polymer of the present description has an electrical conductivity of less than about 1×10 -8 S / m electrical insulator. On the other hand, the elastic polymer of the present description has an electrical conductivity of less than about 1×10 -9 In another aspect, the elastic polymer of the present disclosure has an electrical conductivity of less than about 1×10 -10 S / m electrical insulator.

[0016] The first elastic polymer layer 4 and the second elastic polymer layer 8 may comprise at least one of a thermoplastic polymer, a thermosetting polymer, and combinations thereof. In one aspect, suitable elastic polymers for the first elastic polymer layer 4 and the second elastic polymer layer 8 have a viscosity of about 1000 to about 100,000 cP under typical processing conditions. In another aspect, suitable elastic polymers for the first elastic polymer layer 4 and the second elastic polymer layer 8 have a viscosity of about 1000 to about 25,000 cP under typical processing conditions. In yet another aspect, suitable elastic polymers for the first elastic polymer layer 4 and the second elastic polymer layer 8 have a viscosity of about 25,000 to about 50,000 cP under typical processing conditions. In another aspect, suitable elastic polymers for the first elastic polymer layer 4 and the second elastic polymer layer 8 have a viscosity of about 50,000 to about 75,000 cP under typical processing conditions. In another aspect, suitable elastic polymers for the first elastic polymer layer 4 and the second elastic polymer layer 8 have a viscosity of about 75,000 to about 100,000 cP under typical processing conditions. In certain examples, suitable thermoplastic elastomers used herein have a viscosity of about 1000 to about 50,000 cP under typical processing conditions. As used herein, the term "typical processing conditions" includes temperatures from about room temperature (about 25° C.) to about 400° C., from about room temperature to about 200° C., or from about room temperature to about 100° C. Measurement techniques for measuring viscosity may include a viscometer, a rheometer, or other suitable viscosity testing equipment. Such thermoplastic elastomers are convenient for manufacturing flexible materials.

[0017] Suitable elastic polymers for the first elastic polymer layer 4 and the second elastic polymer layer 8 include thermoplastic elastic polymers, thermosetting elastic polymers, and combinations thereof. For example, suitable elastic polymers for the first elastic polymer layer 4 and the second elastic polymer layer 8 include silicones, fluorosilicone, perfluoropolyether, polybutadiene, polyester, polycarbonate, polyurethane, polyurea, polyurethane-urea, epoxy resin, acrylate, natural rubber, butyl rubber, polyacrylonitrile, ethylene-propylene-diene monomer (EPDM) rubber, or combinations thereof. The first elastic polymer layer 4 and the second elastic polymer layer 8 can be formed from the same or different polymer compositions.

[0018] In the context of this specification, a slurry is any high viscosity fluid. The slurry of this specification is not solidified or hardened into a solid state. Instead, the slurry of this specification maintains a high viscosity fluid state. In one aspect, the slurry of this specification is a material having a viscosity in the range of about 2,000 to about 1,000,000 cP. On the other hand, the slurry of this specification is a material having a viscosity in the range of about 2,000 to about 500,000 cP. In yet another aspect, the slurry of this specification is a material having a viscosity in the range of about 2,000 to about 100,000 cP.

[0019] The conductive paste is a paste capable of carrying an electric current. In one aspect, the conductive paste of the present disclosure has an electrical conductivity greater than about 1×10 1 On the other hand, the conductive paste of the present disclosure has a conductivity greater than about 1×10 2 In another aspect, the conductive paste of the present disclosure has a conductivity greater than about 1×10 3 In another aspect, the conductive paste of the present disclosure has a conductivity greater than about 1×10 4 In another aspect, the conductive paste of the present disclosure has a conductivity greater than about 1×10 5 The conductive paste layer 6 may be uniform or heterogeneous.

[0020] On the one hand, the conductive paste comprises a metal or alloy having a melting temperature (e.g., melting point) lower than about 60°C. In one aspect, the metal or alloy has a melting temperature (e.g., melting point) lower than about 50°C. On the other hand, the metal or alloy has a melting temperature (e.g., melting point) lower than about 40°C. On another hand, the metal or alloy has a melting temperature (e.g., melting point) lower than about 30°C. On another hand, the metal or alloy has a melting temperature (e.g., melting point) lower than about 25°C. On another hand, the metal or alloy has a melting temperature (e.g., melting point) lower than about 20°C. The conductive paste of the present specification is not limited to comprising a metal or alloy. For example, the conductive paste of the present specification may include a conductive polymer instead of a metal or alloy having a melting temperature (e.g., melting point) lower than about 60°C.

[0021] The metal or alloy having a melting temperature below about 60°C of the conductive paste can include any metal or alloy having a melting temperature below about 60°C. In one aspect, the metal or alloy includes at least one of gallium, mercury, indium, tin, bismuth, phosphorus, lead, zinc, cadmium, antimony, and combinations thereof. Suitable metals include, for example, gallium and mercury. Suitable alloys include, for example, alloys formed from gallium, mercury, indium, tin, bismuth, phosphorus, lead, zinc, cadmium, antimony, and combinations thereof. In certain examples, the alloy comprises at least about 50% by weight of gallium, bismuth, indium, mercury, or combinations thereof. In certain examples, tin, phosphorus, lead, zinc, cadmium, antimony, or combinations thereof may be included to modify the melting temperature of the alloy. In one example, the alloy used in the conductive composite material disclosed herein is an alloy comprising indium and about 50% to about 97% by weight of gallium. In another example, the low-melting-point alloy used to form the conductive composite material disclosed herein is an alloy comprising about 15% to about 30% by weight of indium, about 55% to about 80% by weight of gallium, and at least one metal selected from tin and zinc. Weight percent refers to the amount by weight of the corresponding component of a metal or alloy based on the total weight of the metal or alloy. Suitable gallium alloys are commercially available from Indium Corporation. Exemplary 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.

[0022] In one aspect, the conductive paste layer includes a thickener. When used, the thickener is typically combined with a metal or alloy having a melting temperature below about 60°C and thus becomes a component of the conductive paste layer.

[0023] The thickener may include, for example, at least one of an organic thickener, an inorganic thickener, and combinations thereof. When the thickener includes an organic thickener, the organic thickener may include, for example, at least one of maltose, carbon, and combinations thereof. When the thickener includes an inorganic thickener, the inorganic thickener may include, for example, at least one of silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, and combinations thereof.

[0024] In some instances, the average aspect ratio of the thickener is in the range of 1 to about 2. Low aspect ratio thickeners can take the form of, for example, a powder. Low aspect ratio thickeners can have, for example, an average maximum dimension in the range of about 0.1 μm to about 500 μm, such as in the range of about 50 μm to about 150 μm. In other instances, the average aspect ratio of the thickener is greater than about 2, for example in the range of about 2 to about 2000. High aspect ratio thickeners can take the form of, for example, a rod or wire. High aspect ratio thickeners can have, for example, an average maximum dimension in the range of about 0.1 mm to about 10 mm.

[0025] The thickeners used herein act as viscosity modifiers and can help to hinder or minimize the flow of the metal or alloy within the conductive paste layer. The thickeners used herein can be inorganic or organic materials. Thickeners do not dissolve the metal or alloy or otherwise form a solution with the metal or alloy; they remain solid when mixed with the metal or alloy but are wetted by the metal or alloy. Thickeners are typically used as particles, such as rods, wire-shaped particles, substantially spherical particles, or a mixture thereof, and the particle size determines the ease with which the powder and the metal or alloy are homogenized to form a slurry. Generally, thickeners with a higher surface area will be better thickeners than agents with a lower surface area. The combination of thickener and metal or alloy is selected to achieve appropriate wetting of the thickener and the rheology or modulus of the slurry. The particle size and amount are selected to produce a slurry composition with a tan δ value greater than about 1, i.e., a slurry that behaves more like a liquid than a solid, thereby making the resulting composite material flexible.

[0026] The thickener may be conductive or non-conductive. Conductive thickeners increase the conductivity of the resulting conductive composite material 2 or can reduce the amount of conductive paste 6 required to achieve the same conductivity.

[0027] In certain examples, the thickener includes particles (eg, rods or wires) of an inorganic thickener having an average aspect ratio greater than about 2 (ie, wherein the length is at least about twice the width). The average aspect ratio can be measured using a microscope.

[0028] In other examples, the thickener comprises particles (e.g., substantially spherical particles) of an inorganic thickener having an average aspect ratio of less than about 2 (i.e., wherein the length is at most about twice the width). In certain examples, the thickener comprises substantially spherical particles of an inorganic thickener having 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 have a suitable surface area to be used as a thickener to form a slurry with a metal or alloy. In certain instances, 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 instances, the thickener comprises substantially spherical particles of an inorganic thickener having an average particle size of about 50 μm to about 150 μm. In certain instances, the particles of the inorganic thickener have an average particle size of about 0.1 μm to about 5 μm.

[0029] In one example, the thickener is an inorganic thickener having an average aspect ratio greater than about 2 and comprises rods or wires having a length of about 0.01 mm to about 10 mm. In certain examples, the rods of the inorganic thickener have a length of 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 10 mm, or about 0.01 mm to about 0.1 mm, or about 0.1 mm to about 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 conductive rods or wires contributes to a greater conductivity of the final composite material than that of substantially spherical conductive particles. The overall conductivity is adjustable by adjusting the amount of metal or alloy or the amount of thickener.

[0030] In certain examples, the inorganic thickener includes 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.

[0031] In some instances, the thickener comprises particles of an organic thickener having an average particle size of about 0.1 μm to about 500 μm. In some instances, 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 instances, the thickener comprises particles of an organic thickener having an average particle size of about 50 μm to about 150 μm. In certain examples, the particles of the organic thickener have an average size of about 0.1 μm to about 5 μm.

[0032] In instances where the slurry further comprises a thickener, the thickener may be used in an amount to produce an appropriate viscosity and / or adjust the conductive properties of the slurry and the resulting composite material. Suitable concentrations of inorganic thickeners in the slurry range from about 0.1% to about 20% by weight of the slurry composition. Suitable concentrations of organic thickeners in the slurry range from about 0.1% to about 40% by weight of the slurry composition.

[0033] A suitable volume-based amount of the thickener in the slurry composition is from about 5% to about 50% of the slurry volume. In certain instances, the amount of the thickener is from about 5% to about 10%, or from about 5% to about 15%, or from about 10% to about 20%, or from about 15% to about 25%, or from about 20% to about 30%, or from about 25% to about 35%, or from about 30% to about 45% of the slurry composition volume. Such amounts are convenient for producing a slurry composition having a tan delta value greater than 1 (i.e., the slurry behaves more like a liquid than a solid, thereby making the resulting composite material flexible).

[0034] As described above, when a powder having rod or wire-shaped particles is used as a thickener, the amount of thickener can be reduced. A suitable amount of rod or wire thickener in the slurry is from about 2% to about 40% by volume of the slurry. In certain instances, the amount of thickener is from about 2% to about 5%, or from about 5% to about 10%, or from about 10% to about 15%, or from about 15% to about 20%, or from about 20% to about 25%, or from about 25% to about 30%, or from about 30% to about 40% by volume of the slurry composition.

[0035] Suitable electrical conductivity can be achieved in the conductive composites disclosed herein without requiring a large amount of solid conductive particles in the slurry, i.e., a loading of such particles greater than about 45% by volume. However, in certain instances, if insufficient metal is present in the liquid phase to form the desired level of electrical connectivity between the metal particles, a loading of metal particles greater than about 45% by volume can be employed in the slurry. Thus, particle loading levels higher than about 45% by volume (e.g., from about 45% by volume to about 80% by volume) can be used in the slurry when desired.

[0036] In some instances, the thickener used to prepare the conductive composite is an organic thickener. Suitable organic thickeners include compounds having a melting temperature above about 60°C (i.e., a temperature that would prevent the thickener from melting the alloy, i.e., before or during the production of the conductive composite). Examples of these compounds include maltitol, phenol, naphthalene, 1-naphthol, 2-naphthol, 4-pyridone, and carbon (including, for example, graphite and carbon black). If the organic thickener is a compound having a phenolic hydroxyl group, the compound can react with the isocyanate group of a diisocyanate or polyisocyanate via the hydroxyl group, but the reaction will be slower than a urethane or urea-forming reaction. When used appropriately, these compounds can be used to modify the properties of the resulting thickener. Alternatively, the organic thickener can be graphite or carbon particles.

[0037] In certain examples, the thickener is an inorganic thickener or a combination of inorganic thickeners. Suitable inorganic thickeners include metal oxides, such as titanium dioxide, zinc oxide, nickel oxide, metals or alloys having a melting temperature greater than about 60°C, or ceramic materials. The metal or alloy is selected to have a melting temperature greater than about 60°C to prevent the thickener from melting before or during the fabrication of the conductive composite. Suitable metals or alloys include silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, and combinations thereof.

[0038] The thickener may be a mixture of at least one organic thickener and at least one inorganic thickener. A mixture of organic and inorganic thickeners may be used to modify the rheology or modulus of the slurry.

[0039] In certain examples, the thickener comprises a powder having particles in the shape of rods, wires, substantially spherical particles, or mixtures thereof, and the rods, wires, and substantially spherical particles comprise metals or alloys of silver, copper, brass, nickel, stainless steel, steel, aluminum, carbon, coated carbon, titanium, tungsten, tin, zinc, and combinations thereof, metal oxides of nickel, ceramics, and combinations thereof, wherein the substantially spherical particles have an average particle size of about 0.1 μm to about 500 μm (from about 100 nm to about 500,000 nm), and the rods and wires have a length of about 0.01 mm to about 10 mm.

[0040] In one aspect, the conductive paste layer includes a compatibilizer. The compatibilizer may include, for example, at least one of an organic compatibilizer, an inorganic compatibilizer, and combinations thereof. When the compatibilizer includes an organic compatibilizer, the organic compatibilizer may include, for example, a surfactant, such as an ionic surfactant, a nonionic surfactant, and combinations thereof. When the compatibilizer includes an inorganic compatibilizer, the inorganic compatibilizer may include, for example, metal nanoparticles.

[0041] The compatibilizers used herein improve the processability (e.g., fluidity, ease of application) of the slurry. Without wishing to be bound by theory, it is believed that the mixing of the compatibilizer with the low-melting-point metal or alloy produces a coating of the compatibilizer on the surface of the particles or droplets of the low-melting-point metal or alloy, which results in a reduction in the surface energy of the low-melting-point metal or alloy. Furthermore, without wishing to be bound by theory, it is believed that the compatibilizer forms a monolayer or multilayer on the low-melting-point metal or alloy droplets and reduces or prevents oxidation of the metal or alloy, but it does not produce a shell of the type caused by the use of an acid.

[0042] In certain examples, the compatibilizers used herein may also be used to thicken the slurry, ie, to increase the viscosity of the slurry.

[0043] Additionally, if oxidation occurs, a compatibilizer can be added to reactivate the slurry. As used herein, "reactivation" means that a mixture of compatibilizer and low melting point metal or alloy that has been separated can be returned to the form of a homogeneous slurry by adding additional compatibilizer to the separated mixture and subjecting the mixture to appropriate shear conditions as described below.

[0044] In instances where the slurry includes particles of a thickener, as discussed elsewhere herein, it is believed that the disclosed compatibilizers allow for penetration into the pores or voids formed between the particles of the thickener. The process of penetration into the pores incorporates the liquid metal or alloy into the thickener by generating capillary pressure that holds the liquid metal or alloy between the particles.

[0045] In certain examples, the slurry used to form the conductive composite material comprises a low-melting-point metal or alloy and a compatibilizer in a weight ratio of the low-melting-point metal or alloy to the compatibilizer of 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, expressed as a percentage of the low-melting-point metal or alloy, is about 2 wt% to about 20 wt%. Particularly useful amounts of compatibilizer are about 4 wt% to about 10 wt%. The weight percentage refers to the amount of compatibilizer by weight relative to the total weight of the slurry. Phase separation is to be avoided. At higher levels of compatibilizer, phase separation may occur, and this can be addressed using thickeners of the type disclosed elsewhere herein.

[0046] In some instances, the compatibilizer includes inorganic (e.g., metal) nanoparticles having an average particle size 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 size mentioned herein can be measured using, for example, a Coulter Counter or a Multisizer. Suitable nanoparticles include metals that are insoluble in low-melting-point metals or alloys (i.e., insoluble). Suitable metals for use as nanoparticles are those metals in which gallium has a solubility of less than about 5 mol% in the metal at room temperature. Examples of suitable metals used as nanoparticle compatibilizers herein include metals or alloys of silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, and combinations thereof.

[0047] In certain instances, 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 polyols, glycerol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, alkyl polyglucosides, fatty amine oxides, sulfoxides, organic phosphine oxides, and mixtures thereof.

[0048] In some instances, the compatibilizer is an ionic compound. Suitable ionic amphiphilic compounds include anionic compounds and cationic compounds. Representative anionic compounds are alkyl sulfates, alkyl ether sulfates, alkyl sulfonates, alkyl ether sulfonates, alkyl phosphates, and alkyl carboxylates. Representative cationic compounds are quaternary ammonium compounds, monoalkyl ammonium salts, dialkyl ammonium salts, and trialkyl ammonium salts.

[0049] The selection of the specific anionic compound (or mixture thereof) or cationic compound (or mixture thereof) and the amount thereof for forming the conductive paste layer will be determined by the specific elastomeric polymer used to make the conductive composite. The type and amount of the anionic or cationic compound is selected to avoid degradation or depolymerization of the elastomeric polymer.

[0050] In certain instances, the compatibilizer is a surfactant.

[0051] In certain embodiments, the compatibilizer is a nonionic amphiphilic compound or a mixture of such compounds. Particularly useful nonionic amphiphilic compounds are alkylphenol ethoxylates. Representative alkylphenol ethoxylates are octylphenol ethoxylates, such as Triton TMX-100 (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether with an average of 9.5 ethylene oxide units) and nonylphenol ethoxylate.

[0052] Other particularly useful nonionic amphiphilic compounds are poloxamers, which are triblock copolymers of poly(ethylene oxide)poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO). For example, PLURONIC nonionic amphiphilic compounds are suitable.

[0053] The conductive composites of the present disclosure may also include additional materials that impart other properties to the conductive composite. In one aspect, the conductive composite includes an additive that increases thermal oxidative stability. When the conductive composite includes an additive that increases thermal oxidative stability, the additive may include, for example, at least one of phosphates, iron oxides, phenolic resins, antioxidants, metal passivators, and combinations thereof. A thermal oxidative stabilizer is a material or additive that increases thermal oxidative stability. The thermal oxidative stabilizer may be incorporated into the slurry composition or added to the elastomeric polymer layer prior to forming the conductive composite. Depending on the desired properties of the conductive composite and the environment in which the conductive composite will be used, the thermal oxidative stabilizer may be a phosphate, iron oxide, phenolic antioxidant, metal passivator, or a combination thereof. Adding a thermal oxidative stabilizer to the conductive composites disclosed herein extends the operating temperature of the conductive composite. Suitable metal passivators include nitrates such as nitric acid, citrates such as citric acid, tungstates, molybdates, chromates, and mixtures thereof.

[0054] The slurry can be prepared by mixing the low melting point metal or alloy, the compatibilizer, and any optional components, for example, using a centrifugal planetary mixer or shear mixing capability. The resulting slurry can be stored for future use.

[0055] In certain examples, the loss modulus (G") of the slurry composition disclosed herein and used to prepare the conductive composite material can be greater than the storage modulus (G'), i.e., the slurry composition has a tan delta value greater than 1. Thus, the slurry composition of the present disclosure behaves more like a liquid than a solid. When measured using a dynamic shear rheometer according to ASTM D7175, the slurry composition of the present disclosure has a viscosity of about 500 to about 100,000 cP at 1 Hz.

[0056] The thickness of each layer of the conductive composite material 2 can be adjusted as needed to achieve the desired properties of the final product. Figure 2As shown, first elastic polymer layer 4 has a first thickness 14, and second elastic polymer layer 8 has a second thickness 12. First thickness 14 and second thickness 12 can each be from about 0.01 mm to about 100 mm. In another aspect, first thickness 14 and second thickness 12 can each be from about 0.1 mm to about 10 mm. For example, first thickness 14 and second thickness 12 can each be about 1 mm. First thickness 14 can be the same as or different from second thickness 12. The conductive fluorinated fluid layer has a third thickness 16, which can be less than or equal to at least one of first thickness 14 and second thickness 12. Alternatively, third thickness 16 can be greater than at least one of first thickness 14 and second thickness 12. In one aspect, third thickness 16 is less than the sum of first thickness 14 and second thickness 12. In another aspect, third thickness 16 is less than at least one of first thickness 14 and second thickness 12. For example, first thickness 14 and second thickness 12 can be about 1 mm, and third thickness 16 can be less than about 1 mm. The total thickness of conductive composite material 2 can range from about 0.03 mm to about 200 mm. In one aspect, the total thickness of the conductive composite material 2 can be in a range of about 0.1 mm to about 100 mm. In another aspect, the total thickness of the conductive composite material 2 can be in a range of about 0.5 mm to about 10 mm.

[0057] The conductive composite material 2 may comprise one or more additional elastic polymer layers and one or more additional conductive paste layers. For example, the conductive composite material may comprise a total of five layers, ie three elastic polymer layers alternating with two conductive paste layers.

[0058] In one aspect, the conductive composite material 2 is in the form of a laminate, wherein a continuous conductive paste layer 6 is sandwiched between a first elastic polymer layer 4 and a second elastic polymer layer 8. The continuous conductive paste layer 6 can be flat or curved. In one embodiment, the length of the continuous conductive paste layer 6 is substantially greater than the thickness of the continuous conductive paste layer 6. In one aspect, the length of the continuous conductive paste layer 6 is at least five times the thickness of the continuous conductive paste layer 6. In another aspect, the length of the continuous conductive paste layer 6 is at least twenty times the thickness of the continuous conductive paste layer 6. In yet another aspect, the length of the continuous conductive paste layer 6 is at least fifty times the thickness of the continuous conductive paste layer 6. In another embodiment, the length and width of the continuous conductive paste layer 6 are substantially greater than the thickness of the continuous conductive paste layer 6. In one aspect, the length and width of the continuous conductive paste layer 6 are at least five times the thickness of the continuous conductive paste layer 6. In another aspect, the length and width of the continuous conductive paste layer 6 are at least twenty times the thickness of the continuous conductive paste layer 6. In yet another aspect, the length and width of the continuous conductive paste layer 6 are at least 50 times greater than the thickness of the continuous conductive paste layer 6 .

[0059] The edge of the conductive composite material 2 surrounding the conductive paste layer 6 can be sealed in any manner. In one aspect, the edge of the conductive composite material 2 can be sealed by contact of the second elastic polymer layer 8 with the first elastic polymer layer 4. For example, the first elastic polymer layer 4 and the second elastic polymer layer 8 can be separated by the conductive paste layer 6, except at the edge of the conductive composite material 2 surrounding the conductive paste layer 6 where the first elastic polymer layer 4 and the second elastic polymer layer 8 contact each other. The second elastic polymer layer 8 can be capable of curing to the first elastic polymer layer 4 to form an effective seal. The edge length 18 of the edge of the conductive composite material 2 surrounding the conductive paste layer prevents overstressing the bond between the first elastic polymer layer 4 and the second elastic polymer layer 8. In one aspect, the edge length 18 is greater than at least one of the first thickness 14 and the second thickness 12.

[0060] The conductive paste layer 6 of the present specification provides conductivity to the conductive composite material 2 without requiring rigidity, and the high viscosity of the conductive paste layer suppresses leakage of the conductive paste during coating or use. Figure 2 and 3B As shown, the present invention further includes a reinforcing mesh 10 in contact with the conductive paste layer 6. The reinforcing mesh 10 in contact with the conductive paste layer 6 changes the flow properties of the conductive paste 6 to further reduce the possibility of leaching and better retain the conductive paste 6 within the conductive composite material 2.

[0061] Reinforcement mesh 10 may be free to move relative to first elastic polymer layer 4 and second elastic polymer layer 8 to avoid reducing the elasticity of conductive composite material 2, or reinforcement mesh 10 may be attached to one of first elastic polymer layer 4 and second elastic polymer layer 8 to provide additional structural integrity.

[0062] The reinforcing mesh 10 can be conductive or non-conductive. The conductive reinforcing mesh 10 increases the conductivity of the resulting conductive composite material 2, or the reinforcing mesh 10 can reduce the amount of conductive paste 6 required to achieve the same conductivity. Reducing the amount of conductive paste 6 in the conductive composite material 2 can further reduce the likelihood of leaching and better retain the conductive paste 6 within the conductive composite material 2. In one aspect, the conductivity of the conductive mesh is greater than about 1×10 3 S / m. On the other hand, the conductivity of the conductive network is greater than about 1×10 4 In another aspect, the electrical conductivity of the conductive mesh is greater than about 1×10 5 S / m.

[0063] In one aspect, the reinforcement mesh 10 is a continuous reinforcement mesh layer in contact with the continuous conductive paste layer 6. In one expression, the length of the continuous reinforcement mesh layer is substantially greater than the thickness of the continuous reinforcement mesh layer. In one aspect, the length of the continuous reinforcement mesh layer is at least five times the thickness of the continuous reinforcement mesh layer. In another aspect, the length of the continuous reinforcement mesh layer is at least twenty times the thickness of the continuous reinforcement mesh layer. In yet another aspect, the length of the continuous reinforcement mesh layer is at least fifty times the thickness of the continuous reinforcement mesh layer. In another expression, the length and width of the continuous reinforcement mesh layer are substantially greater than the thickness of the continuous reinforcement mesh layer. In one aspect, the length and width of the continuous reinforcement mesh layer are at least five times the thickness of the continuous reinforcement mesh layer. In another aspect, the length and width of the continuous reinforcement mesh layer are at least twenty times the thickness of the continuous reinforcement mesh layer. In yet another aspect, the length and width of the continuous reinforcement mesh layer are at least fifty times the thickness of the continuous reinforcement mesh layer. The reinforcement mesh 10 may have a length and width greater than, equal to, or less than the length and width of the continuous conductive paste layer 6.

[0064] Additionally, if the conductive composite material 2 is in the form of a laminate, the laminate configuration enables the continuous conductive paste layer 6 and the continuous reinforcing mesh layer 10 to be co-positioned, wherein the continuous conductive paste layer 6 and the continuous reinforcing mesh layer 10 are sandwiched between the first elastic polymer layer 4 and the second elastic polymer layer 8.

[0065] The reinforcing mesh 10 can be or include a fabric, such as a knitted fabric, a woven fabric, or a combination thereof. The fabric can be a non-conductive fabric, a conductive fabric, or a combination thereof. The conductive fabric increases the conductivity of the resulting conductive composite material 2.

[0066] The non-conductive fabric can be or include, for example, polyether-polyurea copolymer, latex, polyparaphenylene terephthalamide, aramid, nylon, polyester, or a combination thereof. However, any fabric chemically suitable for use with the conductive paste 6 can be used. The non-conductive fabric can be coated with a conductive material to produce a conductive fabric.

[0067] The conductive fabric may include or be formed from conductive filaments, coated non-conductive fabrics, or combinations thereof. Exemplary 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. Exemplary coated non-conductive fabrics include metal-coated polyether-polyurea copolymers, metal-coated latex, metal-coated poly(p-phenylene terephthalamide), metal-coated aramid, metal-coated nylon, metal-coated polyester, carbon-coated polyether-polyurea copolymers, carbon-coated latex, carbon-coated poly(p-phenylene terephthalamide), carbon-coated aramid, carbon-coated nylon, carbon-coated polyester, and combinations thereof.

[0068] In certain examples, the conductive composite material 2 of the present disclosure exhibits a minimum sheet resistance of less than about 100 Ω / □. The sheet resistance of a particular conductive composite material will depend on the end use application. For example, when the conductive composite material is used to shield the electrical component from electromagnetic radiation, a minimum sheet resistance of less than about 100 Ω / □ is preferred, e.g., to minimize electromagnetic interference that could damage or harm sensitive electronic devices. Sheet resistivity can be determined using a four-point probe.

[0069] In some examples, the conductive composite material 2 of the present specification exhibits an elongation at break of greater than or equal to about 10%. In other examples, the conductive composite material 2 of the present specification exhibits an elongation at break of greater than or equal to about 25%. In still other examples, the conductive composite material 2 of the present specification exhibits an elongation at break of greater than or equal to about 50%. Elongation at break is measured as the percentage of strain to which a material breaks when a tensile force is applied. Elongation at break is expressed as a percentage of the original length.

[0070] In certain examples, the conductive composite material 2 of the present description exhibits a tensile strength greater than or equal to about 3 MPa.

[0071] In some examples, the conductive composite material 2 of the present disclosure 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 some examples, the conductive composite material has a density between about 2 g / mL and about 10 g / mL. In other examples, the conductive composite material has a density between about 10 g / mL and about 20 g / mL. In other examples, the conductive composite material 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.

[0072] In certain examples, the conductive composite material 2 of the present specification exhibits a conductivity of about 5×10 5 Maximum bulk conductivity in S / m.

[0073] In some instances, the conductive composite material is flexible. In some instances, the conductive composite material has a tensile strength greater than or equal to about 3 MPa. In some instances, the conductive composite material is flexible and has a tensile strength greater than or equal to about 3 MPa.

[0074] The present disclosure also provides products, articles, and structures that include a substrate carrying a layer of the conductive composite material disclosed herein. Such products, articles, and structures can be manufactured by heating a thermoplastic or thermoset conductive composite material as disclosed herein and applying it to a substrate. In certain examples, the conductive composite material can be a portion of an aircraft, such as all or a portion of at least one of a wing and a fuselage of the aircraft. In certain examples, the conductive composite material can be at least one of a seal and a gasket.

[0075] like Figure 3A 、 3B As shown in FIG. 3C , the conductive composite material 2 of the present disclosure can be formed by forming a first elastic polymer layer 4 (see FIG. Figure 3A ) and forming a conductive paste layer 6 on the first elastic polymer layer 4 (see Figure 3B ) to manufacture. Before or after forming the conductive paste layer 6, the conductive paste layer 6 is reinforced with a reinforcing mesh 10. Then, a second elastic polymer layer 8 (see Figure 3C ).

[0076] In one aspect, the step of forming the first elastic polymer layer comprises curing the first elastic polymer layer.The step of curing the first elastic polymer layer may comprise curing the first elastic polymer layer.

[0077] In some instances, the step of forming the conductive paste layer includes mixing a metal or alloy having a melting temperature of less than about 60°C with a thickener. In other instances, the step of forming the conductive paste layer includes mixing a metal or alloy having a melting temperature of less than about 60°C with a thickener and a compatibilizer. In other instances, the step of forming the conductive paste layer includes mixing a metal or alloy having a melting temperature of less than about 60°C, a thickener, and an additive for improving thermal oxidative stability, and optionally a compatibilizer. In one aspect, the step of forming the conductive paste layer includes mixing the conductive paste using shear mixing. The shear mixing can be performed at a rotational speed of about 25 to about 2000 rpm, such as about 25 to about 125 rpm. In another aspect, the step of forming the conductive paste layer includes infiltrating the reinforcing mesh 10 with the conductive paste.

[0078] In some examples, forming the second elastic polymer layer includes curing the second elastic polymer layer. Curing the second elastic polymer layer may include bonding the second elastic polymer layer to the first elastic polymer layer.

[0079] After forming the second elastic polymer layer, the method of the present disclosure can include trimming the conductive composite material around the conductive paste layer. In one aspect, the trimming step leaves an edge length around the conductive paste layer.

[0080] As an example, the conductive composite material of the present disclosure can be made by laminating a conductive paste onto the surface of a first cured or partially cured elastomeric polymer and by laminating a second elastomeric polymer thereon.

[0081] In another example, the conductive composite material of the present disclosure can be manufactured by spreading a conductive slurry onto a non-stick surface, applying an uncured elastomeric polymer onto the slurry, and then curing the elastomeric polymer. The conductive composite material can then be conveniently removed from the non-stick surface by peeling the conductive composite material from the non-stick surface. After removal from the non-stick surface, and if necessary or desired, additional layers of cured or uncured elastomeric polymer can be added to the conductive slurry and cured, if necessary, to create a sandwich or laminate structure.

[0082] The laminated composite material of the present disclosure can be manufactured by laminating a conductive paste onto the surface of a first elastic polymer and applying a second elastic polymer layer on the conductive paste layer. The second elastic polymer can be the same as or different from the first elastic polymer. Adding the second elastic polymer layer will encapsulate the conductive paste layer.

[0083] The laminated conductive composite of the present disclosure can also be made 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 conveniently removed from the non-stick surface by peeling the conductive composite from the non-stick surface. If desired, a second elastomeric polymer (which may be the same or different from the first elastomeric polymer) can optionally be applied over the conductive paste layer. Adding the second elastomeric polymer layer will encapsulate the conductive paste layer.

[0084] The non-stick surface can be any suitable non-stick material. Examples of suitable non-stick materials include polytetrafluoroethylene, anodized aluminum, ceramic, and enameled cast iron.

[0085] The present disclosure also provides products, articles, and structures that include a substrate carrying a layer of the conductive composite material disclosed herein, and in certain examples, provides a flexible conductive composite material as disclosed herein. Such products, articles, and structures can be made by heating a thermoplastic or thermoset conductive composite material as disclosed herein and applying it to a substrate.

[0086] The conductive paste composition can be prepared by combining a low melting point metal or alloy with a compatibilizer and thoroughly mixing the resulting mixture to form a uniform slurry. Mixing can be accomplished in a shear mixer at about 25 to about 2500 rpm. In some instances, the shear mixing used to form the slurry composition is performed at about 25 to about 125 rpm, or about 125 to about 250 rpm, or about 250 to about 400 rpm, or about 400 to about 700 rpm, or about 700 to about 1500 rpm, or about 1500 to about 2500 rpm. Alternatively, a centrifugal planetary mixer can be used for mixing. The resulting slurry can be stored for future use.

[0087] Additionally, the surface of the elastic polymer layer facing the conductive paste layer can be treated to improve wetting of the liquid metal. This can include ultraviolet treatment, plasma treatment, or corona discharge treatment. Additionally, a surfactant can be applied to the elastic polymer layer facing the conductive paste layer to improve wetting.

[0088] The following experimental examples illustrate additional features and properties of the conductive composite materials of the present description.

[0089] Example 1

[0090] Conductive paste was prepared by adding 4.93 g of non-ionic surfactant (Triton X100) to 49.63 g of gallium alloy liquid metal and mixing at 2300 rpm for 2 minutes to form a smooth and flowable paste.

[0091] Preparation of the Wetted Reinforcement Mesh: A flowable conductive paste was spread into the silver braid using a paint brush.

[0092] Preparation of Laminated Conductive Composites: NuSil R21-2615 liquid silicone rubber is a two-part, translucent silicone system with a 1:1 Part A to Part B mix ratio that allows for rapid heat curing. Equal parts were weighed into a Flacktek container and mixed at 2300 rpm for 1 minute. The resulting homogenous resin was poured on top of the panel with Mylar release film and a 30 mil thick film was cast using a glass rod. The impregnated reinforcement mesh (silver braid) was placed on top of the NuSil film and the remaining NuSil mixture was poured on top of the reinforcement mesh and evenly spread using a glass rod. The top panel (Mylar release film side down) was placed on top of the resin and the breather sheet on top of the panel. A vacuum connector was placed inside the vacuum bag before sealing, a 0.5 inch slit was cut in the vacuum bag, and the vacuum hose was connected through the slit. Once the system was sealed and the pressure was maintained at -25 inches Hg, the vacuum pump was turned on. The entire vacuum bagging system was placed on top of a 60°C hot spot for rapid thermal curing for approximately 40 minutes. The conductive composite was removed from the system after 1 hour. The thickness of the composite was approximately 0.05".

[0093] Example 2

[0094] Preparation of conductive paste: 4.93 g of non-ionic surfactant (Triton X100) was added to 49.63 g of gallium alloy liquid metal and mixed at 2300 rpm for 2 minutes to form a smooth and flowable conductive paste.

[0095] Preparation of the impregnated reinforcement mesh: A flowable conductive slurry was spread into the Chloroban fabric using a paint brush.

[0096] Preparation of Laminated Conductive Composites: Nusil R21-2615 liquid silicone rubber is a two-part, translucent silicone system with a 1:1 Part A to Part B mix ratio that allows for rapid heat curing. Equal parts were weighed, introduced into a Flacktek container, and mixed at 2300 rpm for 1 minute. The resulting homogenous resin was poured on top of the panel with Mylar release film, and a 30 mil thick film was cast using a glass rod. The impregnated reinforcement mesh (Chloroban) was placed on top of the NuSil film, and the remaining NuSil mixture was poured on top of the fabric and evenly spread using a glass rod. The top panel (Mylar release film side facing down) was placed on top of the resin and the breather sheet on top of the panel. A vacuum connector was placed inside the vacuum bag before sealing, a 0.5 inch slit was cut in the vacuum bag, and the vacuum hose was connected through the slit. Once the system was sealed and the pressure was maintained at -25 inches Hg, the vacuum pump was turned on. The entire vacuum bagging system was placed on top of a 60°C hot spot for rapid thermal curing for approximately 40 minutes. The conductive composite was removed from the system after 1 hour. The resulting composite had a thickness of approximately 0.03".

[0097] Table 1 shows the mechanical properties of Example 1 of the present specification, which was tested before and after aging in air at 100° C. for 50 days.

[0098] Table 1

[0099]

[0100] Table 2 shows the conductive properties of Examples 1 and 2 of the present specification.

[0101] Table 2

[0102]

[0103] Examples of the present disclosure can be combined with Figure 4 Aircraft manufacturing and service method 1000 is shown and Figure 5 A depiction of aircraft 1002 is shown. During pre-production, aircraft manufacturing and service method 1000 may include specification and design 1004 of aircraft 1002 and material procurement 1006. During production, component / subassembly manufacturing 1008 and system integration 1010 of aircraft 1002 takes place. Thereafter, aircraft 1002 may undergo certification and delivery 1012 for entry into service 1014. While in service with a customer, aircraft 1002 may be scheduled for routine maintenance and service 1016, which may also include modification, reconfiguration, refurbishment, and the like.

[0104] Each process of method 1000 may be performed or executed by a system integrator, a third party, and / or an operator (e.g., a customer). For purposes of this description, 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; and an operator may include, but is not limited to, an airline, a leasing company, a military entity, a maintenance organization, etc.

[0105] Conductive composite materials of the present disclosure may be employed during any one or more of the stages of aircraft manufacturing and service method 1000 , including specification and design 1004 of aircraft 1002 , material procurement 1006 , component / subassembly manufacturing 1008 , system integration 1010 , certification and delivery 1012 , aircraft placement into service 1014 , and routine care and maintenance 1016 .

[0106] like Figure 5 As shown, an aircraft 1002 produced by exemplary method 1000 may include an airframe 1018 having a plurality of systems 1020 and an interior 1022. Examples of plurality of systems 1020 may include one or more of a propulsion system 1024, an electrical system 1026, a hydraulic system 1028, and an environmental system 1030. Any number of other systems may be included. The conductive composite materials disclosed herein may be used in any system of aircraft 1002.

[0107] In addition, the present disclosure includes the following embodiments:

[0108] 1. A conductive composite material (2), comprising:

[0109] a first elastic polymer layer (4);

[0110] a conductive paste layer (6) on the first elastic polymer layer (4);

[0111] a second elastic polymer layer (8) on the conductive paste layer (6); and

[0112] A reinforcing mesh (10) in contact with the conductive paste layer (6).

[0113] 2. The conductive composite material (2) according to clause 1, wherein the conductive paste layer (6) comprises a metal or alloy having a melting temperature below about 60°C, and a thickener.

[0114] 3. The conductive composite material (2) according to clause 2, wherein the metal or alloy comprises at least one of gallium, mercury, indium, tin, bismuth, phosphorus, lead, zinc, cadmium, antimony and combinations thereof.

[0115] 4. The conductive composite material (2) according to clause 2 or 3, wherein the thickener comprises at least one of an organic thickener, an inorganic thickener, and a combination thereof.

[0116] 5. The conductive composite (2) according to any one of clauses 2 to 4, wherein the thickener comprises an organic thickener, wherein the organic thickener comprises at least one of maltose, carbon, and combinations thereof.

[0117] 6. The conductive composite (2) of any one of clauses 2 to 4, wherein the thickener comprises an inorganic thickener, wherein the inorganic thickener comprises at least one of silver, copper, brass, bronze, nickel, stainless steel, carbon, coated carbon, titanium, tungsten, and combinations thereof.

[0118] 7. The conductive composite material (2) according to any one of clauses 2 to 6, wherein the thickener has an average aspect ratio in the range of 1 to about 2.

[0119] 8. The conductive composite (2) according to any one of clauses 2 to 7, wherein the thickener has an average aspect ratio in the range of 1 to 2 and an average maximum dimension in the range of about 0.1 μm to about 500 μm.

[0120] 9. The conductive composite (2) according to any one of clauses 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.

[0121] 10. The conductive composite (2) of any one of clauses 2 to 6, wherein the thickener has an average aspect ratio greater than about 2.

[0122] 11. The conductive composite (2) of any one of clauses 2 to 6, wherein the thickener has an average aspect ratio in the range of about 2 to about 2000.

[0123] 12. The conductive composite (2) of any one of clauses 2 to 6, wherein the thickener has an average aspect ratio in the range of about 2 to about 2000 and an average maximum dimension in the range of about 0.1 mm to about 10 mm.

[0124] 13. The conductive composite material (2) according to any one of clauses 1 to 12, wherein the conductive paste layer (6) further comprises a compatibilizer.

[0125] 14. The conductive composite material (2) according to any one of clauses 1 to 13, wherein the conductive paste layer (6) further comprises a compatibilizer, and wherein the compatibilizer comprises at least one of an organic compatibilizer, an inorganic compatibilizer, and a combination thereof.

[0126] 15. The conductive composite (2) according to any one of clauses 1 to 14, wherein the conductive paste layer (6) further comprises an organic compatibilizer, and wherein the organic compatibilizer comprises a surfactant.

[0127] 16. The conductive composite material (2) according to any one of clauses 1 to 15, wherein the conductive paste layer (6) further comprises an organic compatibilizer, and wherein the organic compatibilizer comprises at least one of an ionic surfactant, a nonionic surfactant, and a combination thereof.

[0128] 17. The conductive composite material (2) according to any one of clauses 1 to 16, further comprising an additive for increasing thermo-oxidative stability.

[0129] 18. The conductive composite material (2) according to any one of clauses 1 to 17, further comprising an additive for increasing thermo-oxidative stability, wherein the additive comprises at least one of phosphates, iron oxides, phenols, antioxidants, metal passivators and combinations thereof.

[0130] 19. The conductive composite material (2) according to any one of clauses 1 to 18, wherein the first elastic polymer layer (4) comprises at least one of a thermoplastic polymer, a thermosetting polymer and combinations thereof.

[0131] 20. A conductive composite material (2) according to any one of clauses 1 to 19, wherein the first elastic polymer layer (4) comprises at least one of silicone, fluorosilicone, perfluoropolyether, polybutadiene, polyester, polycarbonate, polyurethane, polyurea, polyurethane-urea, epoxy resin, acrylate, natural rubber, butyl rubber, polyacrylonitrile, ethylene-propylene-diene monomer (EPDM) rubber and combinations thereof.

[0132] 21. The conductive composite material (2) according to any one of clauses 1 to 20, wherein the second elastic polymer layer (8) comprises at least one of a thermoplastic polymer, a thermosetting polymer and combinations thereof.

[0133] 22. A conductive composite material (2) according to any one of clauses 1 to 21, wherein the second layer of elastomeric polymer (8) comprises at least one of silicone, fluorosilicone, perfluoropolyether, polybutadiene, polyester, polycarbonate, polyurethane, polyurea, polyurethane-urea, epoxy resin, acrylate, natural rubber, butyl rubber, polyacrylonitrile, ethylene-propylene-diene monomer (EPDM) rubber and combinations thereof.

[0134] 23. The conductive composite material (2) according to any one of clauses 1 to 22, wherein the thickness of the first elastic polymer layer (4) is in the range of about 0.01 mm to about 100 mm.

[0135] 24. The conductive composite material (2) according to any one of clauses 1 to 23, wherein the thickness of the first elastic polymer layer (4) is in the range from about 0.1 mm to about 10 mm.

[0136] 25. The conductive composite material (2) according to any one of clauses 1 to 24, wherein the thickness of the second elastic polymer layer (8) is in the range of about 0.01 mm to about 100 mm.

[0137] 26. The conductive composite material (2) according to any one of clauses 1 to 25, wherein the thickness of the second elastic polymer layer (8) is in the range of about 0.1 mm to about 10 mm.

[0138] 27. The conductive composite material (2) according to clause 1, wherein the thickness of the conductive paste layer is less than or equal to at least one of the thickness of the first elastic polymer layer (4) and the thickness of the second elastic polymer layer (8).

[0139] 28. The conductive composite material (2) of Clause 1, wherein the thickness of the conductive paste layer is greater than at least one of the thickness of the first elastic polymer layer (4) and the thickness of the second elastic polymer layer (8).

[0140] 29. The conductive composite material (2) according to clause 1, wherein the thickness of the conductive paste layer is greater than the sum of the thickness of the first elastic polymer layer (4) and the thickness of the second elastic polymer layer (8).

[0141] 30. The conductive composite material (2) according to any one of clauses 1 to 29, wherein the conductive paste layer (6) is homogeneous.

[0142] 31. The conductive composite material (2) according to any one of clauses 1 to 29, wherein the conductive paste layer (6) is non-homogeneous.

[0143] 32. A conductive composite material (2) according to any one of clauses 1 to 31, wherein the reinforcing web (10) comprises a fabric.

[0144] 33. The conductive composite material (2) according to any one of clauses 1 to 33, wherein the reinforcing mesh (10) comprises at least one of a knitted fabric, a woven fabric, and combinations thereof.

[0145] 34. The conductive composite material (2) according to any one of clauses 1 to 34, wherein the reinforcing web (10) comprises at least one of a non-conductive fabric, a conductive fabric, and combinations thereof.

[0146] 35. A conductive composite material (2) according to any one of clauses 1 to 34, wherein the reinforcing mesh (10) comprises a non-conductive fabric comprising at least one of polyether-polyurea copolymer, latex, polyparaphenylene terephthalamide, aromatic polyamide, nylon, polyester and combinations thereof.

[0147] 36. A conductive composite material (2) according to any one of clauses 1 to 34, wherein the reinforcing web (10) comprises a conductive fabric comprising at least one of conductive filaments, a coated non-conductive fabric, and combinations thereof.

[0148] 37. A conductive composite material (2) according to any one of clauses 1 to 34, wherein the reinforcing mesh (10) comprises a conductive fabric comprising conductive filaments, wherein the conductive filaments comprise 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.

[0149] 38. A conductive composite material (2) as described in any of clauses 1 to 34, wherein the reinforcing mesh (10) comprises a conductive fabric, the conductive fabric comprising a coated non-conductive fabric, wherein the coated non-conductive fabric comprises at least one of metal-coated polyether-polyurea copolymer, metal-coated latex, metal-coated polyparaphenylene terephthalamide, metal-coated aromatic polyamide, metal-coated nylon, metal-coated polyester, carbon-coated polyether-polyurea copolymer, carbon-coated latex, carbon-coated polyparaphenylene terephthalamide, carbon-coated aromatic polyamide, carbon-coated nylon, carbon-coated polyester and combinations thereof.

[0150] 39. The conductive composite material (2) according to any one of clauses 1 to 38, wherein the conductive composite material (2) exhibits a minimum sheet resistance of less than about 100 Ω / □.

[0151] 40. The conductive composite material (2) according to any one of clauses 1 to 39, wherein the conductive composite material (2) exhibits an elongation at break greater than or equal to about 10%.

[0152] 41. The conductive composite material (2) according to any one of clauses 1 to 40, wherein the conductive composite material (2) exhibits an elongation at break greater than or equal to about 15%.

[0153] 42. The conductive composite material (2) according to any one of clauses 1 to 40, wherein the conductive composite material (2) exhibits an elongation at break greater than or equal to about 50%.

[0154] 43. The conductive composite material (2) according to any one of clauses 1 to 42, wherein the conductive composite material (2) exhibits a tensile strength greater than or equal to about 3 MPa.

[0155] 44. The conductive composite material (2) according to any one of clauses 1 to 43, wherein the conductive composite material (2) has a density of less than about 7 g / mL.

[0156] 45. The conductive composite material (2) according to any one of clauses 1 to 44, wherein the conductive composite material (2) has a density of less than about 6 g / mL.

[0157] 46. ​​The conductive composite material (2) according to any one of clauses 1 to 45, wherein the conductive composite material (2) has a density of less than about 5 g / mL.

[0158] 47. The conductive composite material (2) according to any one of clauses 1 to 46, wherein the conductive composite material (2) has a density of less than about 4 g / mL.

[0159] 48. A conductive composite material (2) according to any one of clauses 1 to 47, wherein the loss modulus (G") of the conductive paste is greater than the storage modulus (G').

[0160] 49. The conductive composite material (2) according to any one of clauses 1 to 48, which is part of an aircraft.

[0161] 50. The conductive composite material (2) according to any one of clauses 1 to 49, being at least a part of at least one of a wing and a fuselage of an aircraft.

[0162] 51. The conductive composite material (2) according to any one of clauses 1 to 49, which is at least one of a seal and a gasket.

[0163] 52. A method for making a conductive composite material, the method comprising:

[0164] forming a first elastic polymer layer;

[0165] forming a conductive paste layer on the first elastic polymer layer, wherein the conductive paste layer is reinforced with a reinforcing mesh; and

[0166] A second elastic polymer layer is formed on the conductive paste layer.

[0167] 53. The method of clause 52, wherein the step of forming the first elastic polymer layer comprises curing the first elastic polymer layer.

[0168] 54. The method of clause 52 or 53, wherein the step of forming the conductive paste layer comprises mixing a metal or alloy having a melting temperature below about 60°C with a thickener.

[0169] 55. The method of any one of clauses 52 to 54, wherein the step of forming the conductive paste layer comprises mixing a metal or alloy having a melting temperature below about 60°C, a thickener, and a compatibilizer.

[0170] 56. The method of any one of clauses 52 to 55, wherein the step of forming the conductive paste layer comprises mixing a metal or alloy having a melting temperature below about 60°C, a thickener, and an additive for increasing thermo-oxidative stability.

[0171] 57. The method of any one of clauses 52 to 56, wherein forming the conductive paste layer comprises compounding the conductive paste using shear mixing.

[0172] 58. The method of any one of clauses 52 to 57, wherein forming the conductive paste layer comprises mixing the conductive paste using shear mixing, wherein the shear mixing is performed at a rotation speed of about 25 rpm to about 2000 rpm.

[0173] 59. The method of any one of clauses 52 to 58, wherein forming the conductive paste layer comprises mixing the conductive paste using shear mixing, wherein the shear mixing is performed at a rotation speed of about 25 rpm to 125 rpm.

[0174] 60. The method according to any one of clauses 52 to 59, wherein the step of forming the conductive paste layer comprises infiltrating the reinforcing mesh (10) with the conductive paste layer.

[0175] 61. The method of any of clauses 52 to 60, wherein the step of forming the second elastic polymer layer comprises curing the second elastic polymer layer.

[0176] 62. The method of clause 61, wherein curing the second elastic polymer layer comprises bonding the second elastic polymer layer to the first elastic polymer layer.

[0177] 63. The method of any one of clauses 52 to 62, wherein the first and second elastic polymer layers encapsulate the conductive paste layer.

[0178] 64. The method of any of clauses 52 to 63, further comprising trimming the conductive composite material surrounding the conductive paste layer.

[0179] 65. The method of any one of clauses 52 to 64, wherein the step of trimming the conductive composite material around the conductive paste layer leaves an edge length around the conductive paste layer.

[0180] 66. The method of any of clauses 65 to 66, wherein the edge length is greater than or equal to at least one of the thickness of the first elastic polymer layer and the thickness of the second elastic polymer layer.

[0181] Although various embodiments of the disclosed conductive composite and method for making the conductive composite have been shown and described, modifications may occur to those skilled in the art upon reading this specification. The present application includes such modifications and is limited only by the scope of the claims.

Claims

1. A conductive composite material comprising: a first elastic polymer layer; a conductive paste layer on the first elastic polymer layer; a second elastic polymer layer on the conductive paste layer; and a reinforcing mesh in contact with the conductive paste layer, The slurry is a material having a viscosity ranging from 2,000 cP to 1,000,000 cP.

2. The conductive composite material according to claim 1, wherein The conductive paste layer includes a metal or alloy having a melting temperature lower than 60° C., and a thickener.

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

4. The conductive composite material according to claim 2 or 3, wherein: The thickener includes at least one of an organic thickener, an inorganic thickener, and a combination thereof.

5. The conductive composite material according to claim 2 or 3, wherein: The thickener has an average aspect ratio in the range of 1 to 2 and an average maximum dimension in the range of 0.1 μm to 500 μm.

6. The conductive composite material according to claim 2 or 3, wherein: The thickener has an average aspect ratio in the range of 2 to 2000 and an average maximum dimension in the range of 0.1 mm to 10 mm.

7. The conductive composite material according to claim 1, wherein The conductive paste layer further includes a compatibilizer, wherein the compatibilizer includes at least one of an organic compatibilizer, an inorganic compatibilizer, and a combination thereof.

8. The conductive composite material according to claim 1, further comprising an additive for increasing thermo-oxidative stability, wherein The additive comprises at least one of phosphates, iron oxides, phenols, antioxidants, metal passivators, and combinations thereof.

9. The conductive composite material according to claim 1, wherein The first elastic polymer layer comprises at least one of a thermoplastic polymer, a thermosetting polymer, and combinations thereof.

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

11. The conductive composite material according to claim 1, wherein The reinforcing mesh includes at least one of a knitted fabric, a woven fabric, and a combination thereof.

12. The conductive composite material according to claim 1, wherein The reinforcement mesh includes a conductive fabric comprising at least one of conductive filaments, a coated non-conductive fabric, and combinations thereof.

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

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

15. A method for making a conductive composite material, the method comprising: forming a first elastic polymer layer; forming a conductive paste layer on the first elastic polymer layer, wherein the conductive paste layer is reinforced with a reinforcing mesh; and forming a second elastic polymer layer on the conductive paste layer, The slurry is a material having a viscosity ranging from 2,000 cP to 1,000,000 cP.

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