Aerogel composition for thermal insulation

Abstract

The thermal control member contains a mixture of a) silica aerogel particles having a particle size in the range of 0.1 mm to 5 mm and b) hydrophobic silica-containing particles having at least 30 methanol values and a particle size D50 of 100 microns or less. In this mixture, the particle size distribution of the silica-containing particles has at least two peaks. The silica aerogel particles and the hydrophobic silica-containing particles are present in a ratio of 1:99 to 99:1, and the thermal control member has a thermal conductivity at 25 °C of 5 to 30 mW / m·K and a thickness of 0.1 to 10 mm.

Description

[Technical Field]

[0001] The present invention relates to an aerogel blend composition for thermal insulation, and more particularly to an aerogel blend composition for thermal insulation of multi-cell rechargeable batteries. [Background technology]

[0002] Aerogel particles can have very low density, high porosity, and small pore size. Aerogels, especially silica aerogels, are useful as insulating materials due to their low density and low thermal conductivity. Aerogels can be formed by removing solvents from hydrogels, such as by supercritical drying techniques or by methods combining solvent substitution and atmospheric pressure drying. Silica aerogels are typically hydrophilic, but can be made hydrophobic by the use of specific treatment agents.

[0003] In its broadest sense, i.e., "a gel having air as a dispersion medium," aerogels are produced by drying a suitable gel. When used in this sense, the term "aerogel" includes aerogels in the narrow sense, such as xerogels and cryogels. If the temperature at which the liquid is removed from the gel is above the critical temperature and the pressure is above the critical pressure, the gel is called an aerogel in the narrow sense. In contrast, if the liquid is removed from the gel below critical, for example, with the formation of a gas-liquid interface phase, the resulting gel is often called a xerogel. It should be noted that the gel according to the present invention is an aerogel in the sense that it is a gel having air as a dispersion medium.

[0004] Insulating materials are used in a variety of applications to provide an insulating layer. For example, insulating materials or thermal control components in the form of panels or blankets are used in applications including, but not limited to, construction, refrigerators, material handling (e.g., for insulating pipes), and rechargeable batteries. These insulating materials may contain aerogels and / or other particles to hinder heat conduction, suppress heat loss due to infrared radiation, and provide other desirable properties. In addition, these insulating materials may have additional components such as glass fibers to provide additional functions such as mechanical integrity and flame retardancy.

[0005] The components of the thermal control member that provide non-insulating properties reduce the degree of insulation provided by the article. Therefore, it is desirable to have a thermal control member that incorporates insulating particles to compensate for the influence of other components on the thermal properties. [Overview of the project]

[0006] The thermal control member comprises a) a mixture of silica aerogel particles having a particle size in the range of 0.1 mm to 5 mm, and b) hydrophobic silica-containing particles having a methanol value of at least 30 and a particle size D50 of 100 microns or less, wherein the particle size distribution of the silica-containing particles has at least two peaks. The silica aerogel particles and hydrophobic silica-containing particles are present in a ratio of 1:99 to 99:1, and the thermal control member has a thermal conductivity of 5 to 30 mW / m·K at 25°C and a maximum thickness of 10 mm.

[0007] Hydrophobic silica-containing particles can be selected from the group consisting of silica aerogel, fumed silica, silicon-treated carbon black, silica-coated carbon black, fumed mixed metal oxides, precipitated silica, silica-carbon black composite particles, rice husk silica, and sol-gel silica. For example, hydrophobic silica-containing particles can be selected from the group consisting of silica aerogel, fumed silica, and sol-gel silica. Hydrophobic silica-containing particles may be hydrophobized with a silicone fluid, cyclic siloxane, hydrophobized silane, functionalized silane, or silazane. Hydrophobic silica-containing particles are 30-550 m 2 / g, preferably 30-250m 2 These may be hydrophobic fumed silica particles having a surface area of ​​ / g.

[0008] Hydrophobized silanes are R 4-n SiX n (wherein n is 1 to 3, each R is independently selected from the group consisting of hydrogen, C1 to C30 branched and linear alkyl or alkenyl groups, C3 to C18 haloalkyl groups, C3 to C10 cycloalkyl groups, and C6 to C14 aromatic groups, and each X is independently a C1 to C18 branched or linear alkoxy group or a halo). The functionalized silane may contain at least one functional group selected from the group consisting of acrylate, methacrylate, amino, anhydride, epoxy, halogen, hydroxyl, sulfur, vinyl, isocyanate, and combinations thereof. The particle size D50 of the hydrophobic silica-containing particles may be 0.1 microns to 100 microns.

[0009] The mixture may further contain fibers. The fibers may be glass fibers, ceramic fibers, synthetic polymer fibers, carbon fibers, natural polymer fibers, mineral wool, or a mixture of two or more of these. The fibers may be blackened or coated with metal.

[0010] An opacifying agent can be incorporated into at least a portion of the silica aerogel present in the thermal control member. At least a portion of the silica aerogel may be coated or impregnated with a heat-absorbing material. The mixture may further contain one or more components selected from the group consisting of fibers, opacifying agents, fire retardants, heat-absorbing materials, phase change materials, binders, defoamers, dispersants, emulsifiers, surfactants, and flocculants.

[0011] The thermal control member may further include a sheet or mat containing silicone, polyvinylidene fluoride, chlorinated polyethylene, aramid fiber, or aramid aerogel. The thermal control member may further include an envelope for enclosing the mixture. The thermal control member may be in the form of a blanket or press pad. The thermal control member may meet the specifications of UL94 V0.

[0012] Please understand that both the general description above and the detailed description below are merely illustrative and descriptive, and further illustrate the claimed invention. [Modes for carrying out the invention]

[0013] The thermal control member comprises a) a mixture of silica aerogel particles having a particle size in the range of 0.1 mm to 5 mm, and b) hydrophobic silica-containing particles having a methanol value of at least 30 and a particle size D50 of 100 microns or less, wherein the particle size distribution of the silica-containing particles has at least two peaks. The silica aerogel particles and hydrophobic silica-containing particles are present in a ratio of 1:99 to 99:1, and the thermal control member has a thermal conductivity of 5 to 30 mW / m·K at 25°C and a maximum thickness of 10 mm.

[0014] Any type of silica aerogel particles can be used in the mixture. The aerogel can be formed as described in U.S. Patent No. 7,470,725. Suitable aerogels can be made from water glass or organic materials such as TEOS and TMOS. To reduce the effect of radiation on thermal conductivity, IR opacifiers such as carbon black, alumina, graphite, titanium dioxide, iron oxide, silicon carbide, zirconium dioxide, or mixtures thereof can be incorporated into the aerogel particles. Aerogel particles are available from various suppliers, including Cabot Corporation's ENOVA and ENTERA brands, and JIOS Aerogel's AEROVA brand.

[0015] The silica aerogel of component a) may have particle sizes ranging from 0.1 mm to 5 mm, for example, 0.1 mm to 4 mm, 0.1 mm to 1.5 mm, 0.5 mm to 4 mm, or 1 mm to 4 mm. The aerogel may have a narrow or broad particle size distribution and may be in the form of a crushed powder. The particle size can be measured by sieving.

[0016] Various hydrophobic silica aerogels can be used. Hydrophobic silica aerogels are aerogels that exhibit a water contact angle greater than 90 degrees. Examples include, but are not limited to, aerogels commercially available from Cabot Corporation. Specific commercially available types include, but are not limited to, ENOVA® brand aerogels, ENTERA brand aerogels, and P100 and P200 aerogels available from Cabot Corporation. Since the aerogel is preferably pre-formed before the assembly of the aerogel-containing envelope, any desired aerogel structure, morphology, or other properties can be selected, and these properties may be inherently present in the final product. Aerogel particles are also commercially available as mixtures with opacifying agents such as carbon black.

[0017] In some embodiments, aerogel particles having a porosity higher than about 60% and a density of less than about 0.4 g / cc can be used. In other embodiments, the aerogel particles may have a density of about 0.05 to about 0.15 g / cc. The thermal conductivity of the aerogel particles may be less than about 40 mW / m·K, less than about 25 mW / m·K, or about 12 mW / m·K to about 18 mW / m·K, or less. To reduce flammability, for example, the aerogel particles may be low-calorie aerogels, such as those having a calorie content of less than 10 MJ / kg, less than 8 MJ / kg, less than 7 MJ / kg, or less than 6 MJ / kg. The aerogel particles may be present in an amount of 10% to 90% by weight based on the total dry weight of the mixture. This amount may be 20% to 80% by weight, 30% to 70% by weight, 40% to 70% by weight, 50% to 90% by weight, 60% to 90% by weight, 10% to 30% by weight, 10% to 40% by weight, or any range based on any two values ​​listed herein.

[0018] The hydrophobic silica-containing particles may be a second silica aerogel or hydrophobic silicon-treated carbon black, silica-coated carbon black, silica-carbon black composite particles, fumed silica, fumed mixed metal oxide, hydrophobic precipitated silica, rice husk silica, or sol-gel silica. Preferably, the hydrophobic silica-containing particles are a second silica aerogel or hydrophobic fumed silica. Infrared absorption capacity can be introduced to the thermal control member using hydrophobic silicon-treated carbon black, silica-coated carbon black, silica-carbon black composite particles, or titania-containing mixed metal oxide. The methanol value of the hydrophobic silica-containing particles may be at least 30, for example, at least 35, at least 40, at least 50, at least 60, or at least 70, or 35-80. The methanol value can be measured using a Rhesca Wet-101P powder wettability tester (Rhesca Co. Ltd.) according to the manufacturer's instructions, using 60 mL of starting solution, a stirring speed of 300 rpm, and a methanol flow rate of 2 mL / min. Before adding the sample, degas the starting solution by stirring at 1000 rpm for at least 5 minutes. Measurement is typically performed using 0.1 g of the sample in a 30% methanol starting solution. However, depending on the hydrophobicity of the sample, a more or less hydrophobic starting solution can be used. The test is performed by titrating the starting solution with methanol. The methanol value is the amount of methanol in the solution when the sample, which was initially on top of the starting solution, begins to wet or settle in the solution, and can be automatically calculated by the instrument. Alternatively, the threshold methanol value of a powder can be determined by carefully pouring the sample onto the surface of a methanol-aqueous solution with a known methanol concentration. If the sample does not wet in the solution, the methanol value of the sample is higher than the methanol concentration in the solution.

[0019] The hydrophobic silica-containing particles have a smaller particle size than the silica aerogel, preferably 100 microns or less, for example, a particle size D50 (by volume) of 0.1 to 95 microns, 1 to 90 microns, 5 to 20 microns, 10 to 30 microns, 20 to 40 microns, or 30 to 60 microns, 40 to 70 microns, 60 to 80 microns, or 70 to 100 microns. For example, the second silica aerogel can be crushed, classified, and / or crushed to yield aerogel particles having a smaller size than the (first) silica aerogel particles. Exemplary silica aerogel particles for use as the second silica aerogel include, but are not limited to, Cabot Corporation's TLD201 and TLD203 silica aerogels. Silica aerogel particles and hydrophobic silica-containing particles can exist in mass ratios of 1:99 to 99:1, for example, 80:20 to 20:80, 35:65 to 65:35, 40:60 to 60:40, or 45:65 to 65:45.

[0020] If the hydrophobic silica-containing particles are a second silica aerogel, the aerogel may be of the same or a different type or composition as the (first) silica aerogel, except that it should have different particle sizes as described above. For example, the second silica aerogel may be from the same or a different manufacturer as the first aerogel, or may have the same or a different additives as the first aerogel.

[0021] Alternatively, or in addition, the hydrophobic silica-containing particles may be hydrophobic fumed silica or calcined silica. Fumed silica typically has a particle diameter of 2 to 20 nm and is formed from the gas phase. In one manufacturing process, silica (usually sand) is evaporated at about 2000°C and cooled to form anhydrous amorphous silica particles. Alternatively, silica can be sublimated at about 1500°C in the presence of a reducing agent (e.g., coke) to form SiO, which can then be oxidized to form particulate silica. Other methods for producing fumed silica include, for example, oxidation of SiCl4 at high temperature, or combustion of SiCl4 in the presence of methane or hydrogen.

[0022] A well-established process for producing fumed metal oxides involves hydrolysis of a suitable feedstock vapor (e.g., aluminum chloride for fumed alumina, silicon tetrachloride for fumed silica) in a hydrogen and oxygen flame. The combustion process forms substantially spherical molten particles, and the particle diameter can be varied by controlling process parameters. These molten spheres, called primary particles, collide with each other at their contact points and fuse together to form branched three-dimensional chain aggregates. Aggregate formation is considered irreversible as a result of the fusion between primary particles. During cooling and collection, aggregates may undergo further collisions, resulting in some mechanical entanglement that can lead to the formation of agglomerates. These agglomerates are considered to be loosely bound by van der Waals forces and can be reversed, i.e., deagglomerated, by suitable dispersion in a suitable medium, or by milling, for example in a jet mill or hammer mill.

[0023] For example, alternative methods for producing calcined silica particles have been developed, as described in U.S. Patents 4,755,368, 6551567, and 6,702,994, U.S. Patent Application Publication 20110244387, Mueller, et al., "Nanoparticle synthesis at high production rates by flame spray pyrolysis," Chemical Engineering Science, 58:1969 (2003), Naito, et al., "New Submicron Silica Produced by the Fumed Process," published in NIP 28: International Conference on Digital Printing Technologies and Digital Fabrication 2012, 2012, pp. 179-182, and Kodas and Hampden-Smith, Aerosol Processing of Materials, Wiley-VCH, 1998 (all of which are incorporated by reference). Other methods for preparing calcined silica particles are known.

[0024] In some embodiments, the calcined silica for use in the thermal control members described herein is 30-550 m 2 / g, for example, 75-150, 150-250, 250-350, or 350-400m 2has a BET surface area such as / g. As used herein, the particle size of the calcined silica refers to the size of the agglomerate. Particle size can be measured using a Malvern Mastersizer 3000 equipped with an Aero S dry powder accessory module. The sample is conveyed at a constant speed into a compressed air stream operated at a compressed air supply pressure of 0.05 MPa (0.5 bar). Appropriate feed rate and laser obscuration are maintained throughout the analysis to obtain an acceptable signal-to-noise ratio that provides reliable data. Those skilled in the art will recognize that different fine particles may require different appropriate feed rates and laser obscuration values. Suitable obscuration for fumed silica is typically in the range of 0.4 to 3.0%. The D50 of fumed silica is typically 5 to 40 microns, but may be smaller when the fumed silica is milled. Any hydrophobic fumed silica having a D50 of 100 microns or less can be used.

[0025] Both hydrophilic fumed silica and hydrophobic fumed silica that can be surface treated for use in the embodiments presented herein are commercially available. Non-limiting examples of fumed silica include CAB-O-SIL fumed silica available from Cabot Corporation, HDK fumed silica products available from Wacker Chemie AG, and AEROSIL fumed silica available from Evonik Industries (Essen, Germany).

[0026] Alternatively, or in addition, silica-containing particles containing other materials can also be used. For example, silica-coated carbon black can be used. Exemplary silica-coated carbon blacks are those described in U.S. Patent No. 6,541,113, U.S. Patent No. 6,197,274, and U.S. Patent No. 9,598,560 (all of which are incorporated herein by reference). Silicon-treated carbon black having a silica phase and a carbon phase can also be used. Methods for producing and surface treating various types of silicon-treated carbon black are specified in U.S. Patent Nos. 7,199,176; 6,709,506; 6,686,409; 6,534,569; 6,469,089; 6,448,309; 6,364,944; 6,323,273; 6,211,279; 6,169,129; 6,057,387; 6,028,137; 6,008,272; 5,977, These are described in Patent Nos. 213; 5,948,835; 5,919,841; 5,904,762; 5,877,238; 5,869,550; 5,863,323; 5,830,930; 5,749,950; 5,747,562; 5,622,557; and 6,929,783; and U.S. Patent Application Publication No. 2002 / 0027110 (all of which are incorporated herein by reference in their entirety). Carbon black-silica composite particles, such as those described in U.S. Patent No. 10800925 (whose entirety is incorporated herein by reference), may also be used. Co-fumed silica particles, such as silica-titania or silica-alumina mixed oxides, may also be used. Exemplary hydrophilic and hydrophobic mixed oxides are disclosed in U.S. Patent Nos. 5,424,258, 6,197,469, 7,083,769, U.S. Patent Publication No. 20100016490, U.S. Patent Publication No. 20050239921, 6,328,944, 4,297,143, and 7,897,256 (all of which are incorporated herein by reference).Any of these silica-containing materials, which are no longer hydrophobic, can be surface-treated in the same manner as fumed silica or precipitated silica as described below.

[0027] Precipitated metal oxide particles can be manufactured using conventional techniques, often by coagulating the desired particles from an aqueous medium under the influence of high salt concentrations, acids, or other coagulants. The metal oxide particles are filtered, washed, dried, and separated from the residue of other reaction products by conventional techniques known to those skilled in the art. The precipitated particles are often aggregated in the sense that numerous primary particles agglomerate together to form somewhat spherical aggregated clusters. Non-limiting examples of commercially available precipitated metal oxides include the Hi-Sil® product from PPG Industries, Inc. and the SIPERNAT® product available from Degussa Corporation.

[0028] Sol-gel metal oxide particles, sometimes called colloidal metal oxide particles, are often unaggregated and individually discrete (primary) particles, typically spherical or nearly spherical, but can also have other shapes (e.g., shapes with roughly elliptical, square, or rectangular cross-sections). Sol-gel metal oxides are commercially available or can be prepared by known methods from various starting materials (e.g., wet-process type metal oxides). Sol-gel metal oxide particles are typically produced in a similar manner to precipitated metal oxide particles (i.e., condensed from an aqueous medium), but remain dispersed in a liquid medium (often water alone, or water with a co-solvent and / or stabilizer). Metal oxide particles can be prepared, for example, from silicic acid derived from an alkali silicate solution with a pH of about 9–about 11. The silicate anions undergo polymerization to produce discrete silica particles with the desired average particle size in the form of an aqueous dispersion. Typically, metal oxide starting materials are available as sols. Sols are metal oxides dispersed in a suitable solvent, which is almost always water alone or water containing a co-solvent and / or stabilizer. See, for example, Stoeber, et al., "Controlled Growth of Monodisperse Silica Spheres in the Micron Size Range," Journal of Colloid and Interface Science, 26, 1968, pp. 62-69; Akitoshi Yoshida, Silica Nucleation, Polymerization, and Growth Preparation of Monodispersed Sols, in Colloidal Silica Fundamentals and Applications, pp. 47-56 (HEBergna & WORoberts, eds., CRC Press: Boca Raton, Florida, 2006); and Iler, RK, The Chemistry of Silica, p. 866 (John Wiley & Sons: New York, 1979).Non-limiting examples of commercially available sol-gel metal oxides suitable for use in the present invention include Nissan Chemical's SNOWTEX® products, WRGrace&Co.'s LUDOXY® products, Nyacol Nanotechnologies, Inc.'s NexSil® and NexSil A® series products, Fuso Chemical's Quartron® products, and AkzoNobel's Levasil® products.

[0029] Sol-gel metal oxide particles can have a primary particle size of about 5 to about 100 nm, for example, about 5 to about 10 nm, about 10 to about 20 nm, about 20 nm to about 30 nm, about 30 to about 50 nm, or about 50 to about 70 nm. The metal oxide particles may be spherical or non-spherical. For example, the aspect ratio of the metal oxide particles may be about 1.5 to about 3, for example, about 1.5 to about 1.8, about 1.8 to about 2.1, about 2.1 to about 2.5, about 2.5 to about 2.8, or about 2.8 to about 3. The particle size can be measured by dynamic light scattering.

[0030] Hydrophobic rice husk silica can also be used. Rice husk silica is obtained from rice husks and can be produced by acid extraction followed by combustion, sedimentation, or a sol-gel method. Hydrophobic rice husk silica may also be in the form of an aerogel, as described in Chinese Patent Application Publication No. 101348255, European Patent No. 1689676, or International Publication No. 2022117618. Hydrophobic rice husk silica can also be prepared by calcination, or by other methods known to those skilled in the art, as described in Chinese Patent Application Publication No. 102583403 or Chinese Patent Application Publication No. 1880384.

[0031] In certain embodiments, hydrophobic silica-containing particles can be produced by treating hydrophilic particulate silica, such as fumed silica, precipitated silica, or sol-gel silica, with a surface treatment agent known to those skilled in the art. The silica treatment agent can be any suitable silica treatment agent and can be covalently bonded to the surface of the silica particles or exist as a non-covalent coating. Typically, the silica treatment agent bonds to the silica either covalently or non-covalently. Often, the silica treatment agent can be a silicone fluid, such as an unfunctionalized or functionalized silicone fluid, a cyclic siloxane, a hydrophobic silane, a functionalized silane, a silazane, or, for example, another silica treatment agent known in the art.

[0032] In certain embodiments, the silica treatment agent includes a hydrophobic silane. For example, the silica treatment agent is of formula R 4-n SiX n(wherein n is 1 to 3, each R is independently selected from the group consisting of hydrogen, C1 to C30 branched and linear alkyl or alkenyl groups, C3 to C18 haloalkyl groups, C3 to C10 cycloalkyl groups, and C6 to C14 aromatic groups, and each X is independently a C1 to C18 branched or linear alkoxy group or halo) compound. In certain embodiments, the silica treatment agent comprises a functionalized silane. The functionalized silane may contain at least one functional group selected from the group consisting of acrylates, methacrylates, aminos, anhydrides, epoxys, halogens, hydroxyls, sulfurs, vinyls, isocyanates, and combinations thereof. In certain embodiments, the silica treatment agent comprises a silazane, for example, the silica treatment agent may be a cyclic silazane such as hexamethyldisilazane, octamethyltrisilazane, or one disclosed in U.S. Patent No. 5,989,768. Treatment of fumed silica can also result in a reversal of the particle charge, for example, from negative to positive. In various embodiments of this specification, preferred hydrophobic treatment agents for silica to be used as hydrophobic silica-containing particles include, but are not limited to, siloxane compounds including hexamethyldisilazane, alkyltrialkoxysilane and alkyldialkoxysilane, e.g., octamethyltrimethoxysilane, hexamethyldisiloxane, dimethyldichlorosilane, and cyclic siloxanes, silicone fluids, and siloxane polymers including polydimethylsiloxane, as well as functionalized siloxane polymers such as monofunctional and bifunctional hydroxyl-terminated PDMS and dimethylsiloxane copolymers including methylhydrosiloxane and / or methylhydroxylsiloxane meres.

[0033] Hydrophilic particulate silica can be surface-treated using any suitable method known to those skilled in the art. For example, sol-gel silica can be surface-treated using techniques such as those described in U.S. Patents 7,811,540, 8,202,502, 8,435,474, 8,455,165, 1,040,7571, and 8,895,145 (all of which are incorporated by reference). Dry silica particles can be surface-treated using wet or dry techniques known to those skilled in the art. For example, a dry treatment method may include stirring or mixing a metal oxide and a hydrophobic agent in a fluidized bed reactor. Alternatively, a wet treatment method may include dispersing a metal oxide in a solvent to form a metal oxide slurry and adding a hydrophobic agent to the slurry to modify the metal oxide surface with the hydrophobic agent. In addition, the charge-modified metal oxide can be prepared using a batch or continuous process, in which case the dry metal oxide is thoroughly mixed and brought into contact with a liquid or vapor hydrophobic agent. In a preferred embodiment, the mixture is then held for a certain period of time at a temperature sufficient to modify the surface properties of the metal oxide.

[0034] A mixture of silica aerogel and hydrophobic silica-containing particles may be used in combination with or in conjunction with one or more types of fibers. The fibers can provide strength and mechanical elasticity, reduce flammability, and help prevent particle sedimentation after installation. The fibers may be natural fibers, synthetic fibers, or both. Glass fibers and ceramic fibers can be used. The fibers may be of uniform length or a mixture of fibers of different lengths.

[0035] Glass and ceramic fibers that can be used in various embodiments of this specification may consist of various inorganic oxides such as SiO2, Al2O3, B2O3, Na2O, K2O, CaO, and MgO. Detailed fibers may include one, two, three, four, or more of these oxides. In some embodiments, the fibers may be glass fibers such as borosilicate (B fibers) and calcium aluminoborosilicate (E fibers), which can be obtained from Lauscha Fiber International, and / or silica-based fibers (Q fibers), which can be obtained from Johns Manville, for example. Other types of fibers that can be used in specific embodiments include, but are not limited to, synthetic non-carbon fibers, mineral wool, wollastonite, carbon fibers, ceramics, cellulose, cotton, polyvinyl alcohol (PVA), polybenzimidazole, polyaramid, acrylic, phenol, polypropylene, other types of polyolefins, or organic fibers such as aramid fibers, nylon fibers, or thermoplastic fibers. The fibers may also be coated with metallized polyester fibers such as aluminum. Mixtures of two or more types of fibers may also be used.

[0036] The length and diameter of the fibers can be varied depending on the specific application. In some embodiments, two or more different types of fibers can be used so that the fiber length distribution exhibits a bimodal or multimodal distribution. The fiber length may be in the range of 0.5 cm to 50 cm or more, for example, 0.5 to 2 cm, 1 to 15 cm, or 0.5 to 5 cm. The fibers may have a thickness of 1 nm or less to 1 mm or more, for example, 1 nm to 100 nm, 100 nm to 1000 nm, 1 micron to 10 microns, 10 microns to 50 microns, or 50 microns to 1 mm. It is understood that the diameter of the fibers does not have to be uniform. The aspect ratio (length:diameter) of the fibers may be at least 100:1, for example, 1000:1 to 10000:1. The fibers can be in any configuration known to those skilled in the art. For example, the fibers may be in the form of chopped fibers, microfibers, woven fibers, or nonwoven fibers.

[0037] The fibers can have any cross-sectional shape. They may be circular, polygonal, trilobal, pentalobal, octalobal, strip-shaped, or shaped like a fir tree or dumbbell. The fibers may have a diameter that is uniform or varies along their length. In some embodiments, hollow fibers can be used. Furthermore, the fiber material may be smooth or crimped, curled or straight. In certain embodiments, the fibers can be modified with additives, such as antistatic agents like carbon black. The fibers may also contain IR opacifiers such as carbon black, titanium dioxide, alumina, iron oxide, or zirconium dioxide, silicon carbide, and mixtures thereof, to reduce the effect of radiation on thermal conductivity.

[0038] In addition to containing an IR opacifier, the effect of radiation on thermal conductivity can be further reduced by using blackened fibers such as polyester fibers blackened with carbon black or simply carbon fibers. The mechanical strength of the thermal control member may also be affected by the length and distribution of fibers in the composition. To reduce the increase in thermal conductivity caused by the added fibers, the proportion (by weight) of fibers may be maintained at the lowest concentration required to achieve the desired mechanical strength. The amount of fibers used may be 1% to 99%, for example, 5% to 95%, 10% to 90%, 20% to 30%, 30% to 40%, 40% to 50%, 50% to 60%, 60% to 70%, 70% to 80%, or 80% to 90% of the total components of the thermal control member, depending on the density, diameter, and length of the fibers. In certain embodiments, the fibers may constitute more than 1% by weight, more than 3% by weight, more than 5% by weight, or more than 10% by weight of the thermal control member. In other embodiments, the fibers may constitute less than 5% by weight, less than 3% by weight, or less than 1% by weight of the thermal control member. The thermal conductivity of the fibers may be about 0.01 to about 1 W / m·K, preferably less than about 1 W / m·K.

[0039] Alternatively, or in addition, to reduce radiant heat transfer, opacifiers such as infrared opacifiers may be used in combination with the mixture. IR opacifiers are materials that reduce infrared transmission and include, for example, carbon black, mica, alumina, graphite, titanium dioxide, rutile sand, iron oxide, silicon carbide (SiC), graphite, or zirconium dioxide. Different types of suitable titanium dioxide include, for example, Tipure® (DuPont) and Altiris® (Huntsman). IR opacifiers can be used individually or as a mixture of two or more compounds. IR opacifiers can be added in amounts that yield a target level of IR transmission reduction in the thermal control member. These levels may be, for example, 2% to 150%, 5% to 100%, or 10% to 40% of the opacifier, based on the weight of the mixture of silica aerogel and hydrophobic silica-containing particles. By using two or more opacifiers with different average particle sizes and / or compositions in a single embodiment, a wider range of IR wavelengths can be covered.

[0040] In some embodiments, the thermal control member may include a flame retardant or fire retardant. In some embodiments, the concentration of the fire retardant and / or flame retardant may be in the range of 0.1% to 5.0% by weight, 0.2% to 2.0% by weight, and 0.3% to 1.5% by weight relative to the mass of the thermal control member. The flame retardant may be, for example, an alkali oxide, an alkaline earth metal oxide, an aluminum trihydrate, magnesium hydroxide, antimony oxide, titanium dioxide, rutile sand, a melamine compound, a phosphate compound, or a halogen compound. In certain embodiments, the titanium dioxide particles may have a diameter of about 1.18 μm, 0.9 to 1.3 μm, 0.8 to 1.4 μm, or 0.5 to 4.0 μm, and in certain embodiments, the particle size distribution may have a d50 of about 1.0 μm ± 0.01 μm, ± 0.02 μm, or ± 0.05 μm. Examples of halogenated flame retardants include brominated flame retardants (BFRs), such as organic bromine compounds containing polymeric organic bromine compounds. In some other embodiments, the flame retardant has a structure with a high ratio of heteroatoms to carbon atoms. For example, in some embodiments, the heteroatom:carbon atom ratio may be greater than 0.5:1, greater than 1:1, or greater than 2:1, and in certain embodiments, the heteroatoms may be nitrogen and / or sulfur. The flame retardant and / or fire retardant can be incorporated into a thermal control member at a concentration sufficient to suppress flammability or to meet specifications such as UL94-V0. Alternatively, or in addition, embodiments of the thermal control member may exhibit a calorie content of, for example, less than 10 MJ / kg, less than 8 MJ / kg, less than 5 MJ / kg, less than 3 MJ / kg, less than 2 MJ / kg, or less than 1 MJ / kg, for example, 0.5 MJ / kg or 1 MJ / kg to 5 MJ / kg. The flame retardant or fire retardant may be incorporated into a mixture of silica aerogel and hydrophobic silica-containing particles.

[0041] Alternatively, or in addition, the thermal control member may further include a heat-absorbing material. Such a material helps the thermal control member function not only as an insulator that slows heat transfer, but also as a thermal capacitor that can store thermal energy. Examples of such heat-absorbing materials include aluminum hydroxide and others known to those skilled in the art. Alternatively, or in addition, the heat-absorbing material may include a phase-change material that stores heat by undergoing a thermodynamic phase transition. The heat-absorbing material may be incorporated into a mixture of silica aerogel and hydrophobic silica-containing particles, or it may be attached to the surface of aerogel particles in the mixture, or it may be impregnated into the pores of aerogel particles.

[0042] Alternatively, or in addition, the thermal control member may include additional sheet-like materials to improve mechanical integrity, heat resistance, mechanical elasticity, and / or other properties. Examples include, but are not limited to, silicone-based materials, polyvinylidene fluoride, chlorinated polyethylene, aramid materials such as Kevlar (e.g., aramid fiber woven mats), and Kevlar nanofiber aerogels, such as those described in Lyu, et al., ACS Nano 2019, 13, 2236-2245. Kevlar or other aramid fiber woven mats may be impregnated with shear viscosity-concentrating fluids, such as those described in U.S. Patent No. 7,825,045 (the contents of which are incorporated herein by reference).

[0043] Alternatively, or in addition, the mixture of silica aerogel and hydrophobic silica-containing particles may further contain a binder. Suitable binders include silicone, polyvinyl alcohol, polyvinylidene fluoride, polyethylene terephthalate, polybutylene terephthalate, acrylate polymers, and other heat-resistant and / or flame-retardant polymers known to those skilled in the art. The binder can help prevent widespread dispersion or dissipation of the silica aerogel, hydrophobic silica-containing particles, and other particulate components of the thermal control member in the event of a catastrophic failure or explosion of an insulated article, such as a battery. Binders such as polyvinyl alcohol can also bind additives such as carbon black to the aerogel particles to reduce dust scattering during assembly. The binder may be mixed with some or all of the components of the mixture, including any additives incorporated into the mixture, using an impeller or other suitable apparatus known to those skilled in the art. Preferably, the binder ensures that the aerogel blanket is non-flammable according to UL94 or other flammability test methods.

[0044] Alternatively, or in addition, the mixture of silica aerogel and hydrophobic silica-containing particles may further contain processing aids. The appropriate processing aids depend on the manufacturing method and form of the thermal control member. Suitable processing aids include, but are not limited to, defoamers, surfactants, dispersants, and emulsifiers.

[0045] In some embodiments, the mixture is enclosed within an envelope. The envelope may function to prevent dust scattering, help maintain the shape of the thermal control member, facilitate the operation or installation of the thermal control member, and / or perform other useful functions known to those skilled in the art. The material forming the envelope is preferably a flame-retardant and / or heat-resistant polymer. Exemplary polymers include silicone, polyvinylidene fluoride (PVDF), chlorinated polyethylene, and other similar polymers known to those skilled in the art. Alternatively, or in addition, the envelope material may include reinforcing fibers, such as aramid fibers, to impart fracture resistance. The reinforcing material may be used in combination with other polymers, or the entire envelope may be formed from such a polymer, for example, a woven fabric of aramid fibers.

[0046] The thermal control article may take any form known to those skilled in the art. For example, a fiber-containing blanket or pad may be made using techniques such as those described in, for example, U.S. Patent No. 9,399,864, U.S. Patent Application Publication No. 20210363699, International Publication No. 2022024085, Chinese Patent Application Publication No. 112759353, U.S. Patent No. 11274044, Chinese Patent Application Publication No. 112681009, Chinese Patent Application Publication No. 113943171, Chinese Patent Application Publication No. 110093783, Chinese Patent Application Publication No. 112681009, Japanese Patent Publication No. 2015048543, and / or U.S. Patent Application Publication No. 20200295328 (all of which are incorporated herein by reference). In one embodiment, such as described in U.S. Patent No. 9,399,864, an aqueous slurry is prepared using a mixture of silica aerogel, hydrophobic silica-containing particles, glass fibers, and other desired components of the blanket or pad (e.g., binders, opacifiers, fire retardants, defoamers, etc.). A charged compound or other emulsifier or dispersant is added to the slurry to create an emulsion, which is then coagulated with a flocculant. The resulting flocs are collected on a scrim or belt and dewatered. An air-lay process can also be used, in which the silica aerogel, hydrophobic silica-containing particles, fibers, and other desired components (e.g., opacifiers, fire retardants, etc.) are combined with air and then deposited on an air-permeable scrim. In these embodiments, the fibers may be polymer fibers that can be melted to bind the blanket or pad together, or a silicone or other binder may be sprayed or otherwise attached to one or both sides of the blanket or pad and activated by heating to bind these components together. Exemplary air-ray methods that can be adapted to manufacture blankets or pads according to embodiments of this specification include, but are not limited to, those disclosed in U.S. Patent No. 4,083,913, U.S. Patent Application Publication No. 2004192136, and U.S. Patent No. 6,479,416 (the contents of which are incorporated herein by reference).

[0047] In another embodiment, the mixture, binder, and any other desired components, such as glass fibers, are filled into a mold and pressed into a pad, for example, as described in European Patent No. 3835262 (the entire contents of which are incorporated herein by reference). It may be necessary to heat or otherwise activate the polymer binder in the mold. Alternatively, or in addition, the mixture, binder, and other components may be compounded into a paste and extruded, for example, as described in European Patent No. 3835262 and International Publication No. 2020228998 (the entire contents of which are incorporated herein by reference). Alternatively, or in addition, the mixture may be incorporated into or combined with a polymer foam, as described in International Publication No. 2020211320, Japanese Patent Application Publication No. 2020019925, and / or U.S. Patent No. 10640629 (all contents of which are incorporated herein by reference).

[0048] Alternatively, the mixture and any other desired components may be used to fill an envelope or other cavity using techniques such as those described in Chinese Patent Application Publication No. 113785431, Chinese Patent Application Publication No. 110544809, Japanese Patent Publication No. 2012145204, and / or U.S. Patent Application Publication No. 20210332932 (all of which are incorporated herein by reference). Another preferred technique is to fill an envelope or bag with the mixture in an envelope or bag held in a suitably separated mold. The mold is compressed manually, for example, using a clamp, and then preferably evacuated. For thinner envelopes, it may be desirable to use aerogel with a smaller diameter to facilitate free flow throughout the bag. Alternatively, the required mass of material to produce a desired mass density in an envelope or pouch of a particular volume may be simply filled into the envelope without using a mold. The envelope can then be compressed with rollers to uniformly distribute the mixture throughout the bag. In a preferred embodiment, for example, a film or sheet of polyethylene terephthalate or silicone is placed in a mold on a vibrating table, a mixture is filled into the mold having a cavity, and a portion of the film or sheet is stretched over the cavity. The mold is vibrated and the mixture is packed in by compressing it to 8-12 psi using a plate. A top sheet (or film) large enough to cover the cavity and the stretched portion is placed on top, sealing three sides of the stretched portion with the top sheet. Air is expelled from the resulting envelope, and the fourth side is sealed. In practice, certain components such as fibers and binders may not be necessary if the envelope provides the desired mechanical support. In fact, in some embodiments, it may be desirable to have only an aerogel in the envelope together with any optional opacifier and / or hydrophobic silica-containing particles.

[0049] The thermal control member may be manufactured in a substantially planar or flat form for insertion between cells of a rechargeable battery, such as a lithium-ion battery. The evacuated envelope may be slightly thinner than the space in which the envelope is installed. Once installed, the envelope can be poked to release the vacuum, thereby expanding until it is under compression. As the battery expands and contracts, the thermal control member also expands and contracts freely. Alternatively, or in addition, the envelope does not have to be manufactured as a flat or sheet-like object, but may be manufactured in a specific shape. For example, the thermal control article may be molded to be positioned around a specific component within a battery or other device, and may have a more complex shape.

[0050] In some embodiments, the thermally controlled article includes additional sheet-like material to improve mechanical integrity, heat resistance, mechanical elasticity, and / or other properties. Examples include, but are not limited to, silicone-based materials, polyvinylidene fluoride, chlorinated polyethylene, aramid materials such as Kevlar (e.g., aramid fiber woven mats), and Kevlar nanofiber aerogels, such as those described in Lyu, et al., ACS Nano 2019, 13, 2236-2245. Kevlar or other aramid fiber woven mats may be impregnated with shear viscosity-concentrating fluids, such as those described in U.S. Patent No. 7,825,045 (the contents of which are incorporated herein by reference).

[0051] In some cases, an envelope can be used to serve a purpose such as preventing dust dispersion, helping to maintain the shape of the heat-controlled article, and facilitating its operation or installation. The material forming the envelope is preferably a flame-retardant and / or heat-resistant polymer material, including, for example, silicone, polyvinylidene fluoride (PVDF), chlorinated polyethylene, and other similar polymers known to those skilled in the art. Alternatively, or in addition, the envelope material may include reinforcing fibers, such as aramid fibers, to impart fracture resistance. The reinforcing material may be used in combination with other polymers, or the entire envelope may be formed from such a polymer, for example, a woven fabric of aramid fibers.

[0052] The thermal control member may have a thickness of 0.1 to 10 mm, for example, 0.5 to 8 mm, 1 to 5 mm, or 1.5 to 3 mm. In some embodiments, at least a portion of the components are compressed, for example, between rollers or platens, during the assembly of the thermal control member to reduce the thickness of the final article.

[0053] The thermal control member can exhibit excellent thermal stability. For example, the thermal control member may shrink by less than 2% after aging at 650°C in accordance with ASTM-C356. The thermal conductivity of the thermal control member at 25°C in accordance with the test method ASTM C518 may be less than 30 mW / m·K, preferably less than 25 mW / m·K, more preferably less than 20 mW / m·K, for example, 5 mW / m·K to 20 mW / m·K or 8 mW / m·K to 15 mW / m·K or 15 mW / m·K to 25 mW / m·K.

[0054] Thermally controlled articles may possess flexibility, a property that can be measured according to ASTM C1101 or another suitable technique. Manual bending tests can be particularly useful in the initial screening stages of products.

[0055] In a particular implementation, the thermally controlled article is a blanket having a non-flammable flammability rating in accordance with UL94-V0.

[0056] The present invention will be further illustrated by the following embodiments, which are intended to be essentially illustrative. [Examples]

[0057] Example 1 Vacuum bags (VAC-Master) were cut and resealed using an impulse sealer to form bags defining an 8-inch x 8-inch square opening. Insulating pads were prepared by combining the components listed in Table 1 in either a Flacktek DAC600 Speedmixer (glass fiber-free formulation) or a high-speed stainless steel Waring blender (glass fiber-containing formulation). The glass fiber was 6mm E-glass chopped fiber with a diameter of 6 microns from Lauscha Fiber International. A total of 10.53 g of material was used for each pad. Any mixture was a 50 / 50 mixture by mass. Various particles are listed in Table 2 below, and the particles are manufactured by Cabot Corporation. All have a trimethylsilyl group on their surface. The resulting mixtures were spread uniformly using a spatula in resized vacuum bags until the bag thickness reached the thickness shown in Table 1. The bag was sealed with a VAC-Master VP320 according to the manufacturer's instructions, with the air removed from the bag, the vacuum time set to 20 seconds, the sealing time set to 1.2 seconds, and the cooling time set to 2 seconds. Thermal conductivity and thickness were measured using a Lasercomp™ FOX200 (Waters / TA Instruments) in accordance with ASTM C518. "Vacuum" refers to the measurement at 25°C (15°C on the low-temperature side and 35°C on the high-temperature side) for a prepared sample compressed between two plates at a pressure of approximately 1 psi. "Pop" refers to a hole made in the bag to allow air to pass through the bag; however, the compression of the sample is not released, the amount of air that can enter the bag is limited, and the pressure rises above 1 psi. "No vacuum" means that the compression of the bag is partially released after "popping," allowing the air pressure inside the bag to equalize, leaving the bag compressed at a pressure of approximately 1 psi. [Table 1] [Table 2] Example 2 Nonwoven blankets containing aerogel particles and combinations of different particles (Table 3) were manufactured by a wet-laid process as described below. Process water was prepared by dispersing Barlox 12 dispersant (45 mL), Nalco 7768 rheology modifier (135 mL), and Foamkill 830F defoamer (15 mL) in 75 L of water. 3.8 g of 6 micron diameter microglass fibers (Johns Manville), 1.0 g of 1 / 4 inch chopped glass fibers, 15.6 g of Novacryl PSR 300 binder, the aerogels, silica, and opacifiers listed in Table 3 were added to a WARING heavy-duty blender. Approximately 1 L of the process water prepared above was added to the blender. The mixture in the blender was mixed at high shear (2000 rpm) for 30 seconds to form a slurry, and the slurry was then transferred to a 15-gallon slurry tank filled with 28 L of process water. To destabilize the slurry system, two drops (10 mL) of Percol flocculant were added to the slurry to generate flocs. After flocculation, the drain at the bottom of the slurry tank was opened, and the supernatant was drained through the scrim. The flocs were held in place by the scrim and were uniformly distributed throughout the scrim. Next, the scrim was passed under vacuum to remove excess water from the aerogel flocs. Example 2A was passed through a roll press to reduce the thickness of the blanket. All blankets were placed in a drying oven at 170°C for approximately 30 minutes. [Table 3]

[0058] Example 3 A bag open at one end (VacMaster Vacuum Chamber Pouch, approximately 150 mm × 200 mm, with walls 3 mil (0.76 mm) thick) was placed into a mold having a 5 mm gap. The mold was prepared by clamping two pieces of 3 / 4 inch (19 mm) plywood each approximately 9.5 inches (24.1 cm) square on both sides together with spacers (two paint stirrers) to form a cavity of appropriate size. ENTERA EV5200 aerogel was filled into the bag using vibration and tamping of the mold employed to ensure complete filling of the bag. The filled bag was manually compressed under a load of approximately 5 psi, then evacuated using a Vacmaster VP320 meat packer until a vacuum of approximately 90% was achieved. The evacuated pouch had a particle density of approximately 110 kg / m 3 . Thermal conductivity and thickness were measured as described above, and were found to be 15.96 mW / m·K and 6 mm, respectively.

[0059] Example 4 A bag of the same design as in Example 3 was filled with a predetermined weight of ENTERA EV5200 aerogel. The desired weight was the weight required to achieve a final density of 110 kg / m 3 in a 150 mm × 200 mm × 4 mm pouch. Then, to maintain the filled bag at the desired thickness of approximately 5 mm, the bag was manually compressed by a roller using two rails. The roller was rolled back and forth until the aerogel appeared to be uniformly dispersed. The pack was then placed into a Vacmaster VP320 meat packer, evacuated, and then tested for thermal conductivity and thickness in the same manner as in Example 1. The initial thickness was 3.8 mm initially, and increased to 4.1 mm after the vacuum was released. The thermal conductivity was measured to be 16.30 mW / m·K.

[0060] Example 5 Dispersant (Jeffamine M2070 dispersant, Huntsman), Nalclear 71605 rheology modifier (Nalco), and Foamkill™ 830 defoamer (Crucible Chemical) were dispersed in water, and 2 liters of white (process) aqueous concentrate were prepared using a WARING benchtop heavy-duty blender according to the formulations in Table 5. Mixing was performed at high shear for 10 seconds to form process water. Ceramic fibers (Fiberfrax® 7001 C5 ceramic fibers, Unifrax, high-purity coarsely cut product with an average fiber diameter of 1.5-2.5 microns and a fiber content (fiber index) of 45-55% as measured by conical elutriation), P200 aerogel particles (Cabot Corporation), fumed silica (all CAB-O-SIL brand from Cabot Corporation, as shown in Table 4, properties are described in Table 4, D50 all 5-20 microns), 44 micron rutile titania sand (Loudwolf), F600 6 micron silicon carbide (Sturbridge Metallurgical Services), and aluminum trihydrate (ATH, Sigma Aldrich) were added to a WARING heavy-duty blender in the amounts listed in Table 5. The mixture in the blender was mixed at high shear (15000 rpm) for 20 seconds to form a paste-like dispersion. An acrylic binder (Novacryl PSR 300, Synthomer) and a silicone binder (Dowsil HV 496 resin, Dow) were added to a blender and mixed under high shear for a further 20 seconds to prepare a slurry. To destabilize the slurry system, a flocculant (Sigma Aldrich polydiallyldimethylammonium chloride (PDADMAC), 30% solution) was added to the slurry to generate flocs. Typically, 4-5 grams of flocculant (shown in Table 5) were added to the dispersion until a dense flocculant layer formed on top.

[0061] After flocculation, the slurry was discharged through a single-layer wet-lay forming wire to produce a 30cm x 30cm blanket sheet. The blanket and forming wire were then vacuumed to remove excess water from the aerogel floc. The sample was then passed through a roll press to squeeze out some of the water and compress the various components into a more compact form. All blankets were placed in a 120°C drying oven for approximately 20 minutes.

[0062] The blanket was evaluated for several properties. Thermal conductivity and thickness were measured using a LaserComp Heat Flow Meter instrument in accordance with ASTM C518. The sample was also evaluated according to the UL94 flammability standard. The results are shown in Table 6, demonstrating that surface treatment can improve thermal conductivity without compromising flammability. [Table 4] [Table 5] * Comparative Example [Table 6] [Table 7]

[0063] Example 6 The blanket is approximately 86m 2 CAB-O-SIL TG-6110G silica has a BET surface area of ​​1 / g, a D50 of 9 microns, a methanol wettability of 65-70, and trimethylsilyl groups on its surface, and approximately 35m 2 The blanket is prepared as described in Example 5 using polydimethylsiloxane-surface-treated CAB-O-SIL TG5180 silica, which has a BET surface area of ​​1 / g, a D50 of 5-40 microns, and a methanol wettability higher than 70. The resulting blanket is expected to have a thermal conductivity of 20-30 and an UL94 rating of V0.

[0064] The above description of preferred embodiments of the present invention is presented for illustrative and explanatory purposes only. It is not intended to be exhaustive or to limit the invention to the exact forms disclosed. Modified and altered forms can be considered in light of the above art or obtained from the practice of the invention. The embodiments have been selected and described to illustrate the principles of the invention and their practical application, enabling those skilled in the art to utilize the invention in various embodiments and with various modifications suitable for specific intended uses. The scope of the invention is intended to be defined by the claims and equivalents appended herein. The following embodiments can be cited as examples of the present invention. (Note 1) a) A thermal control member comprising a mixture of silica aerogel particles having a particle size in the range of 0.1 mm to 5 mm, and b) hydrophobic silica-containing particles having a methanol value of at least 30 and a particle size D50 of 100 microns or less, wherein the particle size distribution of the silica-containing particles has at least two peaks. The silica aerogel particles and the hydrophobic silica-containing particles are present in a ratio of 1:99 to 99:1. A thermal control member having a thermal conductivity of approximately 5 to 30 mW / m·K at 25°C and a thickness of 0.1 to 10 mm. (Note 2) The thermal control member as described in Appendix 1, wherein the hydrophobic silica-containing particles are selected from the group consisting of silica aerogel, fumed silica, silicon-treated carbon black, silica-coated carbon black, fumed mixed metal oxide, precipitated silica, silica-carbon black composite particles, rice husk silica, and sol-gel silica. (Note 3) The thermal control member according to Appendix 1 or 2, wherein the hydrophobic silica-containing particles are selected from the group consisting of silica aerogel, fumed silica, precipitated silica, and sol-gel silica. (Note 4) The thermal control member according to any one of the appendices 1 to 3, wherein the hydrophobic silica-containing particles are hydrophobized with a silicone fluid, a cyclic siloxane, a hydrophobized silane, a functionalized silane, or a silazane. (Note 5) The hydrophobic silica-containing particles are 30-550 m 2 / g, preferably 30-250m 2 A thermal control member as described in any one of the appendices 1 to 4, which is a hydrophobic fumed silica particle having a surface area of ​​ / g. (Note 6) The hydrophobic silane is R 4-n SiX n A thermal control member according to any one of the appendices 1 to 5, wherein n is 1 to 3, each R is independently selected from the group consisting of hydrogen, C1 to C30 branched and linear alkyl or alkenyl groups, C3 to C18 haloalkyl groups, C3 to C10 cycloalkyl groups, and C6 to C14 aromatic groups, and each X is independently a C1 to C18 branched or linear alkoxy group or a halo. (Note 7) The thermal control member according to any one of the appendices 1 to 6, wherein the functionalized silane comprises at least one functional group selected from the group consisting of acrylate, methacrylate, amino, anhydride, epoxy, halogen, hydroxyl, sulfur, vinyl, isocyanate, and combinations thereof. (Note 8) The thermal control member according to any one of the appendices 1 to 7, wherein the particle size D50 of the hydrophobic silica-containing particles is 0.1 microns to 100 microns. (Note 9) The thermal control member according to any one of the appendices 1 to 8, wherein the mixture further comprises fibers. (Note 10) The thermal control member according to any one of the appendices 1 to 9, wherein the fiber is glass fiber, ceramic fiber, synthetic polymer fiber, carbon fiber, natural polymer fiber, mineral wool, or a mixture of two or more of these. (Note 11) The thermal control member according to any one of the appendices 1 to 10, wherein the aforementioned fibers are blackened or coated with metal. (Note 12) The thermal control member according to any one of the appendices 1 to 11, wherein an opacifying agent is incorporated into at least a portion of the silica aerogel present in the thermal control member. (Note 13) The thermal control member according to any one of the appendices 1 to 12, wherein at least a portion of the silica aerogel is coated or impregnated with a heat-absorbing material. (Note 14) The thermal control member according to any one of the appendices 1 to 13, wherein the mixture further comprises one or more components selected from the group consisting of fibers, opacifiers, fire retardants, heat-absorbing materials, phase change materials, binders, defoamers, dispersants, emulsifiers, surfactants, and flocculants. (Note 15) A thermal control member according to any one of the appendices 1 to 14, further comprising a sheet or mat containing silicone, polyvinylidene fluoride, chlorinated polyethylene, aramid fiber, or aramid aerogel. (Note 16) A thermal control member according to any one of the appendices 1 to 15, further comprising an envelope for enclosing the aforementioned mixture. (Note 17) The thermal control member according to any one of the appendices 1 to 16, wherein the thermal control member is in the form of a blanket or a press pad. (Note 18) The thermal control member is a thermal control member as described in any one of the appendices 1 to 17, which satisfies the specifications of UL94 V0.

Claims

1. a) A thermal control member comprising a mixture of silica aerogel particles having a particle size in the range of 0.1 mm to 5 mm, and b) hydrophobic silica-containing particles having a methanol value of at least 30 and a particle size D50 of 100 microns or less, wherein the particle size distribution of the hydrophobic silica-containing particles has at least two peaks. The hydrophobic silica-containing particles are selected from the group consisting of fumed silica, silicon-treated carbon black, silica-coated carbon black, fumed mixed metal oxides, precipitated silica, silica-carbon black composite particles, rice husk silica, and sol-gel silica. The silica aerogel particles and the hydrophobic silica-containing particles are present in a ratio of 1:99 to 99:

1. A thermal control member having a thermal conductivity of 5 to 30 mW / m·K at 25°C and a thickness of 0.1 to 10 mm.

2. The thermal control member according to claim 1, wherein the hydrophobic silica-containing particles are selected from the group consisting of fumed silica, precipitated silica, and sol-gel silica.

3. The thermal control member according to claim 1 or 2, wherein the hydrophobic silica-containing particles are hydrophobized with a silicone fluid, a cyclic siloxane, a hydrophobized silane, a functionalized silane, or a silazane.

4. The hydrophobic silica-containing particles are 30 to 550 m 2 The thermal control member according to claim 1 or 2, which is a hydrophobic fumed silica particle having a surface area of ​​ / g.

5. The hydrophobic silane is R 4-n Six n The thermal control member according to claim 3, wherein n is 1 to 3, each R is independently selected from the group consisting of hydrogen, C1 to C30 branched and linear alkyl or alkenyl groups, C3 to C18 haloalkyl groups, C3 to C10 cycloalkyl groups, and C6 to C14 aromatic groups, and each X is independently a C1 to C18 branched or linear alkoxy group or a halo.

6. The thermal control member according to claim 3, wherein the functionalized silane comprises at least one functional group selected from the group consisting of acrylate, methacrylate, amino, anhydride, epoxy, halogen, hydroxyl, sulfur, vinyl, isocyanate, and combinations thereof.

7. The thermal control member according to claim 1 or 2, wherein the particle size D50 of the hydrophobic silica-containing particles is 0.1 microns to 100 microns.

8. The heat control member according to claim 1 or 2, wherein the mixture further comprises fibers.

9. The thermal control member according to claim 8, wherein the fiber is glass fiber, ceramic fiber, synthetic polymer fiber, carbon fiber, natural polymer fiber, mineral wool, or a mixture of two or more of these.

10. The thermal control member according to claim 8, wherein the fibers are blackened or coated with metal.

11. The thermal control member according to claim 1 or 2, wherein at least a portion of the silica aerogel particles present in the thermal control member incorporates an opacifying agent.

12. The thermal control member according to claim 1 or 2, wherein at least a portion of the silica aerogel particles is coated or impregnated with a heat-absorbing material.

13. The thermal control member according to claim 1 or 2, wherein the mixture further comprises one or more components selected from the group consisting of fibers, opacifiers, fire retardants, heat-absorbing materials, phase change materials, binders, defoamers, dispersants, emulsifiers, surfactants, and flocculants.

14. The thermal control member according to claim 1 or 2, further comprising a sheet or mat containing silicone, polyvinylidene fluoride, chlorinated polyethylene, aramid fiber, or aramid aerogel.

15. The thermal control member according to claim 1 or 2, further comprising an envelope for enclosing the mixture.

16. The heat control member according to claim 1 or 2, wherein the heat control member is in the form of a blanket or a press pad.

17. The thermal control member according to claim 1 or 2, wherein the thermal control member satisfies the specifications of UL94 V0.

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