Inorganic fiber composite material, battery pack cover, battery pack, electric mobility

Abstract

Provided is an inorganic fiber composite material that not only has flame resistance or flame screening properties but also has particle bombardment resistance such that the inorganic fiber composite material can withstand particles ejected from a battery module.　This inorganic fiber composite material is characterized by comprising a sheet-form inorganic fiber molded article and also comprising a particle-bombardment-resistant layer on at least one side of the inorganic fiber molded article, the inorganic fiber composite material having the performance indicated below. <Particle bombardment resistance> The performance of the inorganic fiber composite material does not allow penetration when particles having a grain size of F36 (JIS R 6001-1 and JIS R 6001-2) are ejected for 20 seconds using a sand blaster that is set to a nozzle diameter of 8 mm and an air pressure of 0.48 MPa, the distance from the nozzle to a test piece being 350 mm.

Description

Technical Field

[0001] The present invention relates to an inorganic fiber composite material excellent in fire resistance and flame shielding properties, and particularly to an inorganic fiber composite material suitable for covering a battery used in an electric vehicle (EV) or the like.

Background Art

[0002] In recent years, hybrid vehicles equipped with both a battery and a gasoline engine have become commonly seen on the streets. Also, electric vehicles (EVs) driven only by a battery are expected to spread in the future. The batteries of these vehicles, for example, consist of a plurality of battery modules and a battery pack that houses them. The battery module is composed of a plurality of battery cells, and the battery pack is composed of a battery pack tray that houses a plurality of battery modules and a battery pack cover that covers the tray (see, for example, Patent Document 1 below).

[0003] The batteries mounted in vehicles may catch fire due to a collision accident, battery deterioration, or thermal runaway due to abnormal charging. When a fire breaks out, it is required by national and manufacturer standards to delay the spread of fire to the interior of the passenger compartment as much as possible in order to give the driver and other passengers time to escape.

[0004] For example, Patent Document 1 below discloses that an in-vehicle battery container (battery pack) is produced using a laminate in which a non-combustible or flame-retardant fiber layer such as glass fiber is provided on one surface of a synthetic resin plate.

Prior Art Documents

Patent Documents

[0005] [[ID=三十二]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Currently, lithium-ion batteries, which are prone to thermal runaway, are the dominant type of battery used in electric vehicles (EVs). To extend driving range, there is a trend towards further increasing the energy density of batteries. Consequently, the thermal runaway reaction of batteries tends to become more severe. When a lithium-ion battery experiences thermal runaway, not only does the electrolyte ignite, but oxide particles of Li, Ni, Mn, Co, and other materials used in the battery's positive and negative electrodes, as well as graphite particles, may also be ejected.

[0007] Even if the battery pack covering the battery module has fire-resistant or flame-blocking properties, ejected particles can erode the battery pack, creating holes from which flames may erupt, potentially impairing its flame-blocking capabilities. As energy density is expected to increase in the future, battery packs that enclose such batteries will need not only fire resistance and flame protection, but also particle impact resistance to withstand ejected particles.

[0008] Therefore, the object of the present invention is to provide an inorganic fiber composite material that not only has fire resistance and flame-blocking properties, but also particle impact resistance that can withstand particles ejected from a battery module. [Means for solving the problem]

[0009] The gist of this invention is as follows:

[0010] [1] A sheet-like inorganic fiber molded body comprising a particle impact resistant layer on at least one side of the inorganic fiber molded body. An inorganic fiber composite material wherein the bulk density of the inorganic fiber composite material is 0.100 g / cm³. 3 More than 0.500g / cm 3 The following and An inorganic fiber composite material characterized by having the following properties. <Particle impact resistance> The test material was tested using a sandblaster with a nozzle diameter of 8 mm, a distance of 350 mm from the nozzle to the test piece, and an air pressure of 0.48 MPa. The test material was tested for its ability to withstand the discharge of F36 particle size (JIS R6001-1 and JIS R6001-2) for 20 seconds without penetration.

[0011] [2] The inorganic fiber molded article has a basis weight of 1500 g / m². 2 The following, and with a bulk density of 0.1 g / cm³ 3 The inorganic fiber composite material according to [1], characterized in that it is as described above.

[0012] [3] The inorganic fiber composite material according to [1] or [2], characterized in that the inorganic fiber molded body is a needle blanket containing alumina / silica fibers.

[0013] [4] The inorganic fiber composite material according to any one of [1] to [3], characterized in that the thickness of the inorganic fiber molded body exceeds 50% of the total thickness of the inorganic fiber composite material.

[0014] [5] The inorganic fiber composite material according to any one of [1] to [4], characterized in that the particle impact resistant layer has a mass of 70% or less of the mass of the inorganic fiber molded body.

[0015] [6] The inorganic fiber composite material according to any one of [1] to [5], characterized in that the particle impact resistant layer is provided on both sides of the inorganic fiber molded body, and the total mass of the particle impact resistant layer is 140% or less of the mass of the inorganic fiber molded body.

[0016] [7] The inorganic fiber composite material according to any one of [1] to [6], characterized in that the thickness of the particle impact resistant layer is 0.1% or more and 50% or less of the thickness of the inorganic fiber molded body.

[0017] [8] The inorganic fiber composite material according to any one of [1] to [7], characterized in that the particle impact resistant layer is electrically insulating.

[0018] [9] The inorganic fiber composite material according to claims [1] to [8], characterized in that the particle impact resistant layer comprises at least an inorganic material.

[0019]

[10] The inorganic fiber composite material according to [1] to [9], characterized in that the particle impact resistant layer is directly fixed to the inorganic fiber molded body.

[0020]

[11] The inorganic fiber composite material according to any one of [1] to

[10] , characterized in that the particle impact resistant layer is bonded to the inorganic fiber molded body.

[0021]

[12] The inorganic fiber composite material according to any one of [1] to

[10] , characterized in that the particle impact resistant layer is sutured to the inorganic fiber molded body with thread.

[0022]

[13] The inorganic fiber composite material according to any one of [1] to

[10] , characterized in that the particle impact resistant layer and the inorganic fiber molded body are fixed by adhesive tape.

[0023]

[14] The inorganic fiber composite material according to any one of [1] to

[10] , characterized in that the particle impact resistant layer is in the form of a bag, and an inorganic fiber molded body is enclosed therein.

[0024]

[15] The inorganic fiber composite material according to any one of [1] to

[14] , characterized in that the particle impact resistant layer is an inorganic fiber woven fabric.

[0025]

[16] The inorganic fiber composite material according to

[15] , characterized in that the inorganic fiber woven fabric is a glass fiber woven fabric.

[0026]

[17] The inorganic fiber composite material according to

[15] , characterized in that the inorganic fiber woven fabric is a basalt fiber woven fabric.

[0027]

[18] The inorganic fiber composite material according to any one of [1] to

[10] , characterized in that the particle impact resistant layer is formed by impregnating an inorganic fiber molded body with an organic binder to bond the fibers together.

[0028]

[19] A battery pack cover using an inorganic fiber composite material as described in any of [1] to

[18] , wherein the particle impact-resistant layer side of the inorganic fiber composite material is positioned facing the battery side.

[0029] A battery pack characterized by having a battery pack cover

[20]

[19] .

[0030] An electric mobility device characterized by having a battery pack

[21]

[20] . [Modes for carrying out the invention]

[0031] An embodiment of the inorganic fiber composite material of the present invention will be described below. However, the present invention is not limited to this embodiment.

[0032] An inorganic fiber composite material according to one embodiment of the present invention comprises a sheet-like inorganic fiber molded body, and is characterized by having a particle impact resistant layer on at least one side of the inorganic fiber molded body, thereby having particle impact resistant properties. In this invention, particle impact resistance refers to the ability to withstand a 20-second discharge of F36 particle size (JIS R6001-1 and JIS R6001-2) using a sandblaster set to a nozzle diameter of 8 mm, a distance of 350 mm from the nozzle to the test piece, and an air pressure of 0.48 MPa. Further details will be provided later.

[0033] (Inorganic fiber molded material) The inorganic fiber molded article is a sheet-like fiber aggregate having a predetermined thickness, and may be a nonwoven fabric or a woven fabric.

[0034] <Material> The inorganic fibers are not particularly limited, and examples include single or composite fibers such as silica, alumina / silica, zirconia, spinel, and titania containing these. The inorganic fibers are preferably alumina / silica-based fibers, and particularly preferably crystalline alumina / silica-based fibers. The composition ratio (mass ratio) of alumina / silica in the alumina / silica-based fibers is preferably in the range of 60 to 95 / 40 to 5, more preferably in the range of 70 to 84 / 30 to 16, and particularly preferably in the range of 70 to 76 / 30 to 24.

[0035] <Average fiber length> The inorganic fibers are preferably fibers having an average fiber length of 1.0 mm or more, more preferably 2.0 mm or more, and still more preferably 3.0 mm or more. The upper limit is not particularly limited, but is preferably 3.0×10 3 mm or less, more preferably 1.0×10 3 mm or less. The average fiber length of the inorganic fibers is the average value of 300 fibers measured by microscopic observation.

[0036] <Average fiber diameter> The average fiber diameter of the inorganic fibers is preferably 3 μm to 10 μm, particularly 5 μm to 8μm. The average fiber diameter is the average value of 100 fibers measured by microscopic observation. If the average fiber length and average fiber diameter of the inorganic fibers are within the above ranges, it is preferable because the inorganic fiber molded body has high tensile strength. It is also preferable from the viewpoint of suppressing the amount of dust floating in the air.

[0037] <Grammage> The grammage (mass per unit area) of the inorganic fiber molded body is preferably 1500 g / m 2 or less, more preferably 1200 g / m 2 or less, and particularly preferably 900 g / m 2 or less. If the grammage is within the above range, the thickness of the inorganic fiber molded body can be suppressed, and it can be stored in a limited space. It is also preferable from the viewpoint of reducing the vehicle body weight when used for electric mobility. Furthermore, while there is no particular limit to the basis weight, it is preferably 1 g / m². 2 Above, a comfortable 10g / m 2 In particular, 100 g / m² is preferred. 2 That's all. If the basis weight is within the above range, the flame-retardant performance can be further improved in terms of the amount of fiber per unit area.

[0038] <Bulk density> The bulk density of the inorganic fiber molded body is preferably 0.100 g / cm³. 3 More preferably 0.125 g / cm³ 3 In particular, 0.130 g / cm³ is preferred. 3 That's all. Furthermore, while there is no particular upper limit to the bulk density, it is preferably 0.200 g / cm³. 3 More preferably, 0.190 g / cm³ 3 The following is particularly preferred: 0.180 g / cm³ 3 The following applies: If the bulk density is within the above range, the amount of fiber per unit volume is sufficient, so flame-retardant properties can be achieved, which is also preferable from the viewpoint of reducing vehicle weight when used in electric mobility.

[0039] <Thickness> The thickness of the inorganic fiber molded article is preferably more than 50.0% of the total thickness of the inorganic fiber composite material, more preferably 55.0% or more, and particularly preferably 60.0% or more. While not particularly limited, it is also preferable that the thickness be 99.5% or less. Furthermore, the thickness of the inorganic fiber composite material is preferably 0.5 mm to 15.0 mm, more preferably 12.0 mm or less, and particularly preferably 10.0 mm or less. By keeping the thickness within the above range, sufficient flame-retardant performance can be achieved while keeping the battery pack compact.

[0040] The basis weight, bulk density, and thickness of the inorganic fiber molded body can be measured, for example, by the measurement method shown in the following example, and can also be adjusted by changing the amount of fiber per unit area when folding and laminating the inorganic fiber aggregates that constitute the inorganic fiber molded body.

[0041] <Tensile strength> The tensile strength of the inorganic fiber molded article is preferably as high as possible, preferably 1 N / 25 mm or higher, more preferably 10 N / 25 mm or higher, and particularly preferably 20 N / 25 mm or higher. By keeping the tensile strength within the above range, handling performance during processing can be improved. The tensile strength of an inorganic fiber molded article can be measured, for example, by the method shown in the following example.

[0042] <Needle penetration mark density> It is preferable that the inorganic fiber molded body has needle penetration marks, and the unit area (1 cm²) of the mat surface of the inorganic fiber molded body is 2 The number of needle penetration marks per square centimeter (needle penetration mark density) is preferably 35 marks / cm² as an average value across the entire mat surface. 2 More preferably, 32 pieces / cm 2 The following applies: The number of needle penetration marks can be determined by shining visible light on the matte surface of an inorganic fiber molded body. The amount of transmitted light at the needle penetration marks is greater than the amount of transmitted light in areas other than the needle penetration marks. Therefore, the transmitted light is observed as light spots on the delamination surface, and the number of light spots due to transmission to the delamination surface can be counted. The matte surface refers to the surface perpendicular to the thickness direction of the inorganic fiber molded body.

[0043] (Method for manufacturing inorganic fiber molded articles) Inorganic fiber molded articles can be manufactured by a method comprising the steps of obtaining a mat-like aggregate of inorganic fiber precursors by a sol-gel method, applying a needling treatment to the obtained mat-like aggregate of inorganic fiber precursors, and firing the needled mat-like aggregate of inorganic fiber precursors to form an inorganic fiber molded article. However, inorganic fiber molded articles may be manufactured by other methods.

[0044] The following describes an example of a method for manufacturing this inorganic fiber molded article, using the method for manufacturing an alumina / silica-based fiber molded article as an example. However, the inorganic fiber molded article of the present invention is not limited in any way to an alumina / silica-based fiber molded article, and as mentioned above, it may be a molded article made of silica, zirconia, spinel, titania, or composite fibers thereof.

[0045] <Spinning Process> To produce a mat-like aggregate of alumina / silica fibers by the sol-gel method, first, a spinning solution containing basic aluminum chloride, a silicon compound, an organic polymer as a thickener, and water is spun by the blowing method to obtain an aggregate of alumina / silica fiber precursors.

[0046] <<Preparation of spinning solution>> Basic aluminum chloride; Al(OH) 3-x Cl x This can be prepared, for example, by dissolving metallic aluminum in hydrochloric acid or an aqueous solution of aluminum chloride. The value of x in the above chemical formula is usually 0.45 to 0.54, preferably 0.5 to 0.53. While silica sol is preferably used as the silicon compound, other water-soluble silicon compounds such as tetraethyl silicate and water-soluble siloxane derivatives can also be used. Suitable organic polymers include, for example, water-soluble polymer compounds such as polyvinyl alcohol, polyethylene glycol, and polyacrylamide. Their degree of polymerization is typically 1000 to 3000.

[0047] The spinning solution preferably has a ratio of aluminum derived from basic aluminum chloride to silicon derived from silicon compounds, which is typically 99:1 to 65:35, preferably 99:1 to 70:30, when converted to a weight ratio of Al2O3 to SiO2, with an aluminum concentration of 170 g / L to 210 g / L and an organic polymer concentration of 20 to 50 g / L.

[0048] If the amount of silicon compounds in the spinning solution is less than the above range, the alumina constituting the short fibers is more likely to become α-alumina, and the short fibers are more likely to become brittle due to the coarsening of the alumina particles. On the other hand, if the amount of silicon compounds in the spinning solution is more than the above range, the amount of silica (SiO2) produced together with mullite (3Al2O3·2SiO2) increases, and the heat resistance tends to decrease.

[0049] If the aluminum concentration in the spinning solution is less than 170 g / L or the organic polymer concentration is less than 20 g / L, in either case, an appropriate viscosity of the spinning solution cannot be obtained, and the fiber diameter of the resulting alumina / silica-based fibers will be small. In other words, as a result of too much free water in the spinning solution, the drying rate during spinning by the blowing method is slow, the stretching proceeds excessively, the fiber diameter of the spun precursor fibers changes, and short fibers with a predetermined average fiber diameter and a sharp fiber diameter distribution cannot be obtained. Moreover, if the aluminum concentration is less than 170 g / L, productivity decreases. On the other hand, if the aluminum concentration exceeds 210 g / L or the organic polymer concentration exceeds 50 g / L, in either case, the viscosity is too high to become a spinning solution. The preferred concentration of aluminum in the spinning solution is 180 g / L to 200 g / L, and the preferred concentration of organic polymer is 30 g / L to 40 g / L.

[0050] The above spinning solution is prepared by adding an amount of silicon compound and an organic polymer in the above Al2O3:SiO2 ratio to an aqueous solution of basic aluminum chloride, and concentrating it so that the concentrations of aluminum and organic polymer fall within the above range.

[0051] ≪Blowing≫ Spinning (fibrillation of the spinning solution) is usually carried out by a blowing method, in which the spinning solution is supplied into a high-speed spinning airflow, thereby obtaining an alumina short fiber precursor. There are no particular restrictions on the structure of the spinning nozzle used in the above spinning process, but a structure in which the airflow blown out from the air nozzle and the spinning solution flow pushed out from the spinning solution supply nozzle are parallel flows, and moreover, the parallel flow of air is sufficiently rectified to come into contact with the spinning solution, is preferred, for example, as described in Japanese Patent Publication No. 2602460.

[0052] Furthermore, during spinning, it is preferable that, first, sufficiently stretched fibers are formed from the spinning solution under conditions where the evaporation of moisture and the decomposition of the spinning solution are suppressed, and then these fibers are dried quickly. To achieve this, it is preferable to change the atmosphere from a state that suppresses the evaporation of moisture to a state that promotes the evaporation of moisture during the process from when the fibers are formed from the spinning solution until they reach the fiber collector.

[0053] Alumina / silica fiber precursors can be collected and accumulated using an accumulation device that has a structure in which an endless wire mesh belt is set up approximately perpendicular to the spinning airflow, and the spinning airflow containing the alumina / silica fiber precursors is made to collide with the endless belt while it is rotating, thereby recovering them as a continuous sheet-like accumulation (thin layer sheet) of alumina / silica fiber precursors.

[0054] The basis weight of this thin sheet is preferably 10 g / m². 2 ~200g / m 2 Particularly preferred is 30 g / m 2 ~100g / m 2 This is the extent of it, but it is not limited to this.

[0055] The thin sheets recovered from the above-mentioned accumulation device can be further laminated. Specifically, for example, an aggregate of inorganic fiber precursors (thin sheets) can be continuously drawn out and sent to a folding device, where they can be folded to a predetermined width and stacked while being continuously moved in a direction perpendicular to the folding direction to form a laminated aggregate of inorganic fiber precursors (laminated sheet). By laminating the thin sheets in this way, the basis weight (weight) of the laminated sheet becomes uniform throughout the entire sheet. As the above-mentioned folding device, the one described in Japanese Patent Application Publication No. 2000-80547 can be used.

[0056] <Needling aid or friction reducer application process> Needling aids or anti-friction agents are applied to the sheet surface of a thin sheet or laminated sheet of alumina / silica-based inorganic fiber precursor obtained by spinning, as needed. It is preferable to apply the needling aid or anti-friction agent to both sheet surfaces.

[0057] As a needling aid, any agent that has the effect of strengthening the filaments near the mat surface of the inorganic fiber precursor aggregate can be used, and various coating agents, such as acrylic polymer coating agents, can be used.

[0058] As a friction reducer, surfactants or emulsions that reduce friction between the needle and the fiber can be used. Needling aids and friction reducers are applied by coating (wet coating) the solution or dispersion.

[0059] <Needling process> A laminated sheet of alumina / silica-based inorganic fiber precursors obtained by spinning is, if necessary, impregnated with a needling aid and / or an anti-friction agent, and then subjected to a needling process in which a barbed needle is inserted and removed from the laminated sheet. The needling process may be performed from only one side of the laminated sheet or from both sides. Preferably, it is performed from both sides.

[0060] The needle is preferably inserted and withdrawn perpendicular to the sheet surface of the laminated sheet. The needle is inserted deeper than the center in the thickness direction of the laminated sheet. The needle may also be inserted so as to penetrate the laminated sheet in the thickness direction.

[0061] In this way, needle marks are formed on the inorganic fiber molded body by the needling process. That is, when a needling process is performed in which a barbed needle is inserted into and removed from a laminated sheet, at least some of the fibers are extended in the approximate thickness direction by the needle at the locations where the needle was inserted and removed. As a result, needle marks are formed on the surface of the inorganic fiber molded body. Within the inorganic fiber molded body that has undergone the needling process, the strands of inorganic fibers that extend in the approximate thickness direction are called warp strands.

[0062] Needling is performed to adjust the bulk density and peel strength of an inorganic fiber molded body by forming warp threads.

[0063] The needle marks may penetrate the inorganic fiber molded body, or they may penetrate from one mat surface and extend without reaching the other mat surface.

[0064] <Firing Process> The inorganic fiber molded body is preferably a sintered body obtained by sintering a needling-treated inorganic fiber precursor. Sintering is usually carried out at a temperature of 900°C or higher, preferably 1000 to 1300°C. A sintering temperature of 900°C or higher is preferable because it allows for sufficient crystallization, resulting in alumina / silica-based fibers with excellent strength. A sintering temperature of 1300°C or lower is also preferable because it prevents excessive grain growth of the fiber crystals, resulting in alumina / silica-based fibers with moderate strength.

[0065] (Particle impact resistant layer) The particle impact resistant layer is a layer provided to make it difficult for solid particles contained in the positive electrode, negative electrode, current collector, etc. of a battery, such as oxide particles of lithium (Li), nickel (Ni), cobalt (Co), manganese (Mn), and metal particles such as copper (Cu), to penetrate when they collide with it. It is preferably formed from inorganic materials such as glass fibers, basalt fibers, or silica fibers. In addition to inorganic materials, it may also contain organic resins or organic fibers.

[0066] <Material> The particle impact resistant layer is preferably made of an inorganic fiber woven fabric formed by weaving fibers made of the above-mentioned inorganic material, which is preferable from the viewpoint of handling properties when used as a composite material and the ability to suppress the amount of dust generated from the inorganic fiber molded body that floats in the air. Examples of inorganic fiber fabrics include glass fiber fabrics, basalt fiber fabrics, and silica fiber fabrics. Basalt refers to basalt rock. The glass fiber woven fabric preferably has a thickness of 0.01 mm or more and a tensile strength of 1000 N / 25 mm or more. Specific examples of glass fiber woven fabrics include "H201F" manufactured by Unitika Ltd. Although basalt fiber woven fabric has lower tensile strength than glass fiber woven fabric, it has excellent heat resistance, with a heat resistance temperature of approximately 1200°C. Specific examples of basalt fiber woven fabrics include BASALTEX's "BAS350S". Although silica fiber woven fabric has lower tensile strength than glass fiber woven fabric, it has excellent heat resistance, with a heat resistance temperature of approximately 1000°C. Specific examples of silica fiber woven fabrics include "SILIGLASS BCC-665AD" manufactured by Nippon Muki Co., Ltd.

[0067] Furthermore, the particle impact resistant layer may include an inorganic fiber molded body to which an organic or inorganic binder is impregnated, preferably with a thickness of 0.01 mm or more and a tensile strength of 10 N / 25 mm or more. The binder can be impregnated by spraying or the like, and binders made of acrylic latex or alumina sol can be used. The inorganic fiber molded body used in the particle impact resistant layer can be the inorganic fiber molded body described above. The binder can be impregnated, for example, by applying a binder solution (in which the binder is dispersed in a solvent or dispersion medium) to an inorganic fiber molded body to impregnate it, and then removing the solvent by drying.

[0068] Furthermore, the weaving method for inorganic fiber fabrics is not particularly limited; for example, plain weave, twill weave, satin weave, etc., are all acceptable.

[0069] <Mass> When the particle impact-resistant layer is provided on one side of the inorganic fiber molded body, it is preferably 70% or less, more preferably 60% or less, and particularly preferably 50% or less, relative to the mass of the inorganic fiber molded body. Furthermore, when particle impact resistant layers are provided on both sides of the inorganic fiber molded body, the total mass of the particle impact resistant layers used in the inorganic fiber composite material is preferably 140% or less, more preferably 120% or less, and particularly preferably 100% or less, relative to the mass of the inorganic fiber molded body. If the mass is within the above range, it will have sufficient resistance to particle impact and, when used in electric mobility, will be preferable in terms of reducing the vehicle's weight. The lower limit is not particularly limited, but is preferably 1% or more, more preferably 5% or more, and especially preferably 10% or more. By keeping the mass within the above range, sufficient resistance to particle impact can be achieved.

[0070] <Basic weight> The basis weight (mass per unit area) of the particle impact-resistant layer is preferably 10 g / m². 2 ~2000g / m 2 , more comfortably 20g / m 2 ~1500g / m 2 , particularly preferably 30 g / m 2 ~1000g / m 2 That is the case.

[0071] <Bulk density> The bulk density of the particle impact-resistant layer is preferably as high as possible, and there is no particular upper limit, but it is preferably 0.1 g / cm³. 3 More preferably 0.2 g / cm³ 3 In particular, 0.3 g / cm³ is preferred. 3 That's all. By keeping the bulk density within the above range, sufficient resistance to particle impact can be achieved.

[0072] <Thickness> The thickness of the particle impact resistant layer is preferably 0.1% to 50.0%, more preferably 1.0% to 45.0%, and particularly preferably 2.0% to 40.0% of the thickness of the inorganic fiber molded body. By setting the thickness within the above range, it becomes possible to insert it into the limited gap between the battery module and the battery pack cover. More specifically, it is preferably 0.01mm to 5.0mm, more preferably 0.05mm to 4.0mm, and particularly preferably 0.1mm to 3.0mm. By setting the thickness within the above range, sufficient particle impact resistance can be achieved, improving handling performance during processing.

[0073] <Tensile strength> The tensile strength of the particle impact resistant layer is preferably as high as possible, preferably 0.01 kN / 25 mm or higher, more preferably 0.05 kN / 25 mm or higher, and particularly preferably 0.1 kN / 25 mm or higher. By keeping the tensile strength within the above range, sufficient resistance to particle impact can be achieved. The tensile strength of the particle impact resistant layer can be measured, for example, using a tensile testing machine.

[0074] <Electrical insulation> The particle impact resistant layer is preferably electrically insulating. Electrical insulation means that it does not conduct electricity easily; for example, the electrical resistance value is preferably 10Ω or more, more preferably 100Ω or more, and particularly preferably 1000Ω or more. By making the particle impact resistant layer electrically insulating, it is possible to prevent an external short circuit of the battery even if the battery electrodes are unintentionally touched.

[0075] (Laminated structure) Inorganic fiber composite materials are preferably configured as a two-layer structure with a particle impact-resistant layer on one side of the inorganic fiber molded body, but they may also be configured as a three-layer structure with particle impact-resistant layers on both sides. Furthermore, other layers besides the inorganic fiber molded body and particle impact-resistant layers, such as a layer with electromagnetic wave shielding properties, may be laminated to form a three-layer, four-layer, or other laminated structure. A configuration in the range of 2 to 7 layers is preferred, and a configuration in the range of 3 to 5 layers is more preferred. When laminating other layers, the particle impact resistant layer may be provided on one side of the inorganic fiber molded body and the other layer on the other side, or the other layer may be provided between the inorganic fiber molded body and the particle impact resistant layer. From the viewpoint of handling during work, it is preferable that the particle impact resistant layer is directly fixed to the inorganic fiber molded body.

[0076] Inorganic fiber composite materials can be fixed by, for example, bonding each layer with organic or inorganic adhesives or binders, or by suturing them together with threads made of glass fibers or polyester fibers. They may also be fixed with adhesive tape coated with adhesive such as double-sided tape, or with jigs such as tag pins, staples, binder clips, paper clips, safety pins, spring clamps, C-clamps, snap hooks, bolts and nuts, or clip buttons. Furthermore, they may be fixed by enclosing the inorganic fiber molded body in a particle impact-resistant layer processed into a bag shape, without resorting to any of these methods. Organic or inorganic adhesives and binders can be silicone-based or epoxy resin-based adhesives, or binders made of acrylic latex or alumina sol. Specifically, products such as "ThreeBond 1530C" manufactured by ThreeBond Corporation can be used. The yarn can be made from glass fibers, polyester fibers, or other materials; specifically, Unitika Ltd.'s "G37 1 / 2" can be used. The tape can use acrylic adhesives, and specifically, products such as Nitto Denko Corporation's "Super Strong Double-Sided Tape J0960" and Teraoka Seisakusho's "Waterproof Adhesive Tape for Confidential Applications" can be used. Furthermore, as a means of processing the particle impact-resistant layer into a bag shape, the edges of two overlapping impact-resistant layers can be sewn together using the aforementioned thread, adhered with the aforementioned adhesive tape, or secured with tag pins or staples.

[0077] The overall thickness of the inorganic fiber composite material is not particularly limited, but is preferably 1.0 mm to 10.0 mm, more preferably 1.2 mm to 9.5 mm, and particularly preferably 1.5 mm to 9.0 mm. Within the above range, sufficient flame-retardant and particle impact-resistant properties can be achieved, while also allowing for a compact battery pack size. Inorganic fiber composite materials can be used in various shapes, but they are preferably in sheet form. For example, they can be made into rectangular sheets with a length of 10 mm to 5000 mm and a width of 10 mm to 2000 mm.

[0078] The basis weight (mass per unit area) of the inorganic fiber composite material is not particularly limited, but is preferably 5000 g / m². 2 Below is a more comfortable 3000 g / m². 2 The following is particularly preferred: 1500 g / m² 2 The following applies. If the basis weight is within the above range, it is preferable from the viewpoint of reducing the vehicle's weight. Furthermore, while there is no particular limit to the basis weight, it is preferably 10 g / m². 2 Above, a comfortable 50g / m 2 In particular, 100 g / m² is preferred. 2 That concludes the explanation. If the basis weight is within the above range, it is preferable from the viewpoint of the amount of fiber per unit area and the durability against particles ejected when thermal runaway occurs.

[0079] The overall bulk density of the inorganic fiber composite material is not particularly limited, but is preferably 0.100 g / cm³. 3 More preferably 0.125 g / cm³ 3 In particular, 0.130 g / cm³ is preferred. 3 That concludes the explanation. The above range is preferable from the viewpoint of durability against particles ejected during thermal runaway. Furthermore, while there is no particular upper limit to the bulk density, it is preferably 0.500 g / cm³. 3 More precisely, 0.400 g / cm³ 3 The following is particularly preferred: 0.300 g / cm³ 3 The following applies. If the basis weight is within the above range, it is preferable from the viewpoint of reducing the vehicle's weight.

[0080] (Particle cracking resistance) Inorganic fiber composite materials possess particle impact resistance. In this invention, particle impact resistance refers to the ability to withstand the discharge of F36 particle size particles (JIS R6001-1 and JIS R6001-2) onto a test specimen for 20 seconds using a sandblaster set to a nozzle diameter of 8 mm, a distance of 350 mm from the nozzle to the test specimen, and an air pressure of 0.48 MPa, without penetration. For example, a test specimen cut to a length of 150 mm and a width of 100 mm can be used.

[0081] A sandblaster is a device that can eject particles such as abrasives, and conventionally known models can be used. Specifically, the "Sandblaster EA127BK" manufactured by ESCO Corporation can be used.

[0082] The particles used in this process can be, for example, particles made of aluminum oxide, and a particle size of F36 (JIS R6001-1 and JIS R6001-2) can be used.

[0083] Whether or not the test specimen has been penetrated is determined by visual inspection; if the view opposite can be seen through the specimen, it is considered to have penetrated.

[0084] (Application) Inorganic fiber composite materials can be used in a variety of applications, but for example, they can be used in battery packs that cover battery modules, and are particularly suitable for use as covers for battery packs. In this case, it is preferable to position the inorganic fiber composite material so that the particle impact-resistant layer faces the battery and covers the safety valve. Inorganic fiber composite materials can be used with cylindrical, prismatic, or pouch-type battery cells, but they are preferable for prismatic cells, which have a higher electrical density. If battery packs made of inorganic fiber composite materials are installed in electric vehicles, hybrid vehicles, electric motorcycles, ships, trains, and other electric mobility devices, they can block flames and prevent the initial spread of fire even if the battery overheats and catches fire.

[0085] When inorganic fiber composite materials are used in battery packs, they can be laminated onto a base material, and this base material can be, for example, a metal base material or a reinforced resin base material. From the viewpoint of flame resistance, a metal base material is preferred, and suitable materials include aluminum, aluminum alloys, magnesium, magnesium alloys, titanium, titanium alloys, iron, and stainless steel.

[0086] (effect) The inorganic fiber composite material of the present invention has fire resistance and flame-shielding properties because it is made by laminating inorganic fiber molded bodies. Furthermore, because it also has a particle impact-resistant layer, it has particle impact resistance that can withstand, for example, particles ejected from a battery module without being penetrated. Therefore, it can withstand the impact of particles ejected when lithium-ion batteries or the like experience thermal runaway, thus preventing holes from forming and the spread of fire. From this viewpoint, it can be suitably used as a cover for a battery pack. [Examples]

[0087] An embodiment of the inorganic fiber composite material of the present invention is described below. However, the present invention is not limited to this embodiment.

[0088] Examples 1 to 20 and Comparative Examples 1 and 2 shown below were prepared.

[0089] [Example 1] <Inorganic fiber molded product> To an aqueous solution of basic aluminum chloride (aluminum content 165 g / L, Al / Cl = 1.8 (atomic ratio)), silica sol was added so that the final alumina fiber composition would be Al2O3:SiO2 = 72:28 (mass ratio). After adding polyvinyl alcohol, the solution was concentrated to prepare a spinning solution with a viscosity of 70 poise (25°C) and an alumina-silica content of approximately 35% by mass.

[0090] The above spinning solution was spun using the blowing method. As the spinning nozzle, a spinning nozzle with the same structure as that described in Figure 6 of Japanese Patent Publication No. 2602460 was used. Furthermore, for cotton collection, an endless belt made of wire mesh was set approximately perpendicular to the spinning airflow, and the cotton was collected as a continuous sheet (thin sheet) using an accumulation device with a structure that caused the spinning airflow containing alumina / silica-based fiber precursors to collide with the endless belt while it was rotating.

[0091] The thin sheets recovered from the accumulation device were coated with an anti-friction agent by spray, then continuously drawn out and sent to a folding device. There, they were folded to a predetermined width and stacked, while being continuously moved in a direction perpendicular to the folding direction to form laminated sheets. The folding device used was one with a structure similar to that described in Japanese Patent Publication No. 2000-80547.

[0092] The basis weight can be changed by varying the number of times the fiber precursor is folded using the stacking device.

[0093] The mat-like aggregates of alumina / silica fiber precursors obtained by spinning were subjected to needling treatment using needles. Needling was performed by punching using a needle punching machine. Needling was performed on both sides. When needling the laminated sheets of inorganic fiber precursors, the needles were used to penetrate from one side to the other, and the needling was performed so that a predetermined needle penetration mark density was achieved after firing, and an average of 5 barbs per needle penetrated the other side.

[0094] Afterward, it is fired at 1200°C, resulting in a basis weight of 600g / m². 2 (Thickness 4.7mm, bulk density 0.128g / cm³) 3 ), needle penetration mark density 13.7 marks / cm 2 An inorganic fiber molded body consisting of crystalline alumina / silica fibers was obtained. Sintering was performed in an electric furnace, heating to 1200°C at a rate of 5°C / min, holding at 1200°C for 30 minutes, and then allowing to cool naturally. This inorganic fiber molded material was cut out using a die to a length of 150 mm and a width of 100 mm.

[0095] The composition ratio of this crystalline alumina / silica fiber was alumina / silica = 72 / 28 (mass ratio). The average fiber diameter (average of 100 fibers) of the crystalline alumina / silica fiber, measured by microscopic observation of the inorganic fiber blanket, was 5.5 μm, and the average fiber length (average of 300 fibers) was 3 mm.

[0096] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 0.2 mm and a basis weight of 204 g / m². 2 Bulk density 1,200 g / cm³ 3 Glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H201F") was cut to the same size as the inorganic fiber molded body and used.

[0097] (Inorganic fiber composite material) An inorganic fiber composite material of Example 1 was prepared by applying adhesive (ThreeBond 1530C, manufactured by ThreeBond Corporation) to the four corners of one side of an inorganic fiber molded body, and then attaching a particle impact resistant layer on top of it.

[0098] [Example 2] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0099] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 1.2 mm and a basis weight of 1669 g / m². 2 Bulk density 1.415 g / cm³ 3 Glass fiber woven fabric (Unitika Ltd.'s "S018F" fabric) was cut to the same size as the inorganic fiber molded body and used.

[0100] (Inorganic fiber composite material) An inorganic fiber composite material of Example 1 was prepared by applying adhesive (ThreeBond 1530C, manufactured by ThreeBond Corporation) to the four corners of one side of an inorganic fiber molded body, and then attaching a particle impact resistant layer on top of it.

[0101] [Example 3] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0102] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 0.10 mm and a basis weight of 110 g / m². 2 Bulk density 1,100 g / cm³ 3 Glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H105F") was cut to the same size as the inorganic fiber molded body and used.

[0103] (Inorganic fiber composite material) An inorganic fiber composite material of Example 3 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0104] [Example 4] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0105] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 0.26 mm and a basis weight of 313 g / m². 2 Bulk density 1.204 g / cm³ 3 Glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H320F") was cut to the same size as the inorganic fiber molded body and used.

[0106] (Inorganic fiber composite material) An inorganic fiber composite material of Example 4 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0107] [Example 5] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0108] (Particle impact resistant layer) As the particle impact resistant layer, the same layer used in Example 1 was used, with a thickness of 0.2 mm and a basis weight of 204 g / m². 2 Bulk density 1,200 g / cm³ 3 The glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H201F") and the 0.26 mm thick, 313 g / m² basis weight fabric used in Example 4 were used. 2 Bulk density 1.204 g / cm³ 3 Glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H320F") was cut to the same size as the inorganic fiber molded body and used.

[0109] (Inorganic fiber composite material) An inorganic fiber composite material of Example 5 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0110] [Example 6] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0111] (Particle impact resistant layer) As a particle impact-resistant layer, two pieces of the glass fiber woven fabric used in Example 3 (Unitika Ltd.'s "Nama-ki Cloth H105F") were cut to the same size as the inorganic fiber molded body and used.

[0112] (Inorganic fiber composite material) Two particle impact-resistant layers were laminated onto one side of an inorganic fiber molded body, and the four sides were secured with spring clamps to produce the inorganic fiber composite material of Example 6.

[0113] [Example 7] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0114] (Particle impact resistant layer) As a particle impact resistant layer, two pieces of the glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H320F") used in Example 4 were cut to the same size as the inorganic fiber molded body and used.

[0115] (Inorganic fiber composite material) Two particle impact-resistant layers were laminated onto one side of an inorganic fiber molded body, and the four sides were secured with spring clamps to produce the inorganic fiber composite material of Example 7.

[0116] [Example 8] (Inorganic fiber molded material) In Example 1, the basis weight was 900 g / m². 2 (Thickness 5.6mm, bulk density 0.161g / cm³) 3 ), needle penetration mark density 15.1 marks / cm 2 An inorganic fiber molded body was prepared to be a crystalline alumina / silica-based fiber, and this inorganic fiber molded body was cut out using a die to a length of 150 mm and a width of 100 mm for use. The composition ratio of this crystalline alumina / silica fiber was alumina / silica = 72 / 28 (mass ratio). The average fiber diameter (average of 100 fibers) of the crystalline alumina / silica fiber, measured by microscopic observation of the inorganic fiber blanket, was 5.5 μm, and the average fiber length (average of 300 fibers) was 3 mm.

[0117] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 0.14 mm and a basis weight of 154 g / m². 2 Bulk density 1,100 g / cm³ 3 Glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H155F") was cut to the same size as the inorganic fiber molded body and used.

[0118] (Inorganic fiber composite material) An inorganic fiber composite material of Example 8 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0119] [Example 9] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 8 was used.

[0120] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 1.20 mm and a basis weight of 1669 g / m². 2 Bulk density 1.391 g / cm³ 3 Glass fiber woven fabric (Unitika Ltd.'s "S018F" fabric) was cut to the same size as the inorganic fiber molded body and used.

[0121] (Inorganic fiber composite material) An inorganic fiber composite material of Example 9 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0122] [Example 10] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0123] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 0.59 mm and a basis weight of 350 g / m². 2 Bulk density 0.593 g / cm³ 3 Basalt fiber woven fabric (BASALTEX CO., LTD. "BAS350A") was cut to the same size as the inorganic fiber molded body and used.

[0124] (Inorganic fiber composite material) An inorganic fiber composite material of Example 10 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0125] [Example 11] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 8 was used.

[0126] (Particle impact resistant layer) As a particle impact resistant layer, the basalt fiber woven fabric (BASALTEX CO., LTD. "BAS350A") used in Example 10 was cut to the same size as the inorganic fiber molded body and used.

[0127] (Inorganic fiber composite material) An inorganic fiber composite material of Example 11 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0128] [Example 12] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0129] (Particle impact resistant layer) As a particle impact-resistant layer, silica fiber woven fabric ("SILIGLASS BCS-665AD" from Nippon Muki Co., Ltd.) was cut to the same size as the inorganic fiber molded body and used.

[0130] (Inorganic fiber composite material) An inorganic fiber composite material of Example 12 was fabricated by laminating a particle impact-resistant layer onto one side of an inorganic fiber molded body and securing all four sides with spring clamps.

[0131] [Example 13] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was cut out and used.

[0132] (Particle impact resistant layer) For the inorganic fiber molded body prepared in Example 1, an organic binder dispersion (LTX852 manufactured by Nippon Zeon Co., Ltd., hereinafter referred to as "binder liquid") was added in a solid weight equivalent to 1 m³. 2 After uniformly spraying the material at a rate of 54g per unit area, it was dried at a constant temperature of 135°C for 15 minutes. This impregnated the fibers with an organic binder, resulting in a particle impact-resistant layer that bonded the fibers together.

[0133] (Inorganic fiber composite material) An inorganic fiber composite material of Example 13 was fabricated by laminating a particle impact-resistant layer, in which the fibers were bound together with the organic binder, onto one side of the inorganic fiber molded body, and securing all four sides with spring clamps.

[0134] [Example 14] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0135] (Particle impact resistant layer) As a particle impact-resistant layer, the glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H320F") used in Example 4 was cut to the same size as the inorganic fiber molded body and used.

[0136] (Inorganic fiber composite material) Apply adhesive (ThreeBond 1530C, manufactured by ThreeBond Corporation) to one side of the inorganic fiber molded body. 2 The material was applied in an amount of 200g per unit area, a particle impact-resistant layer was attached on top, and it was dried for 24 hours to produce the inorganic fiber composite material of Example 14.

[0137] [Example 15] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0138] (Particle impact resistant layer) As the particle impact resistant layer, the glass fiber woven fabric used in Example 4 (Unitika Ltd.'s "H320F raw fabric cloth") was used.

[0139] (Inorganic fiber composite material) For the inorganic fiber molded body, the binder liquid is applied in terms of solid weight, up to 1 m³. 2 After uniformly spraying the material to a density of 320g per sheet, the glass fiber woven fabric was laminated, and the laminated layers were sandwiched between two sheets of perforated metal to achieve a thickness of 2.7mm. The layers were then dried at a constant temperature of 135°C for 30 minutes. This resulted in the creation of an inorganic fiber composite material, Example 15, in which an inorganic fiber molded body and a particle impact-resistant layer were bonded together with an organic binder.

[0140] [Example 16] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0141] (Particle impact resistant layer) As a particle impact-resistant layer, the glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H320F") used in Example 4 was cut to the same size as the inorganic fiber molded body and used.

[0142] (Inorganic fiber composite material) An inorganic fiber composite material of Example 16 was fabricated by laminating a particle impact resistant layer on one side of an inorganic fiber molded body and sewing it in an X-shape along the diagonal using a thread made of glass fiber (Unitika Ltd.'s "G37 1 / 2").

[0143] [Example 17] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0144] (Particle impact resistant layer) As a particle impact resistant layer, it has a thickness of 0.26 mm and a basis weight of 313 g / m². 2 Bulk density 1.204 g / cm³ 3 Two pieces of glass fiber woven fabric (Unitika Ltd.'s "Sealing Cloth M320F") were cut to the same size as the inorganic fiber molded body and used.

[0145] (Inorganic fiber composite material) An inorganic fiber molded body was placed between two particle impact-resistant layers, and plastic H-shaped tag pins (web thickness 0.4 mm, web length 7.0 mm, short side flange length 6.7 mm, long side flange length 7.8 mm) were driven along the edges using a tag gun to produce the inorganic fiber composite material of Example 17.

[0146] [Example 18] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0147] (Particle impact resistant layer) As a particle impact resistant layer, the glass fiber woven fabric (Unitika Ltd.'s "Nama-ki Cloth H105F") used in Example 3 was cut to be slightly larger than the inorganic fiber molded body, and the two pieces were stacked together and then sewn together along the edges with polyester fiber thread to form a bag.

[0148] (Inorganic fiber composite material) An inorganic fiber composite material of Example 18 was fabricated in which an inorganic fiber molded body was enclosed in a bag formed by sewing three sides of a particle impact-resistant layer together, and the opening of the remaining side of the bag was sewn shut with a thread made of polyester fiber, thereby enclosing the inorganic fiber molded body in a bag-shaped particle impact-resistant layer.

[0149] [Example 19] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0150] (Particle impact resistant layer) As a particle impact resistant layer, the glass fiber woven fabric (Unitika Ltd.'s "Sealing Cloth M320F") used in Example 17 was cut to approximately twice the size of the inorganic fiber molded body and used.

[0151] (Inorganic fiber composite material) An inorganic fiber composite material of Example 19 was fabricated by folding a particle impact-resistant layer in half, placing an inorganic fiber molded body inside, and securing three sides of the particle impact-resistant layer with adhesive tape (Teraoka Seisakusho's "Airtight Waterproof Adhesive Tape"), thereby enclosing the inorganic fiber molded body in a bag-like particle impact-resistant layer.

[0152] [Example 20] (Inorganic fiber molded material) As the inorganic fiber molded body, the inorganic fiber molded body prepared in Example 1 was used.

[0153] (Particle impact resistant layer) As a particle impact resistant layer, the glass fiber woven fabric (Unitika Ltd.'s "Sealing Cloth M320F") used in Example 17 was cut to a size more than twice the area of ​​the inorganic fiber molded body and used.

[0154] (Inorganic fiber composite material) An inorganic fiber composite material of Example 20 was fabricated in which an inorganic fiber molded body was enclosed in a bag-shaped particle impact-resistant layer. An inorganic fiber molded body was placed in the center of the particle impact-resistant layer, and each of the opposing pair of sides of the particle impact-resistant layer was folded back to enclose it so that the ends overlapped, and each of the other pair of sides was folded over by a certain width, and adhesive tape (Teraoka Seisakusho's "Waterproof Adhesive Tape") was applied in an H shape to secure the ends of the folded sides, thereby enclosing the inorganic fiber molded body in the particle impact-resistant layer.

[0155] [Comparative Example 1] The inorganic fiber molded body prepared in Example 1 was used. This inorganic fiber molded body was cut out using a die to a length of 150 mm and a width of 100 mm, and this was designated as Comparative Example 1.

[0156] [Comparative Example 2] As an inorganic fiber molded body, the inorganic fiber molded body prepared in Example 8 was cut out using a die to a length of 150 mm and a width of 100 mm, and this was used as Comparative Example 2.

[0157] [Physical properties] The physical properties of the inorganic fiber molded body and the glass fiber woven fabric used in the particle impact-resistant layer were measured as follows.

[0158] <Basic weight> The basis weight was calculated by dividing the mass measured by a weighing scale by the area of ​​the sample.

[0159] <Bulk density> Bulk density was calculated by dividing the basis weight by the thickness.

[0160] <Thickness> The thickness was measured using a digital dial gauge. The measured load is 4.9 kPa (50 g / cm²). 2 The minimum measurement scale is 0.01 mm. Five thickness measurements were taken at random points on the test specimen, and the average of the five measurements was calculated.

[0161] <Tensile strength> The tensile strength was measured using a tensile testing machine. Inorganic fiber molded material and glass fiber woven fabric were cut using a die to a size of 25 x 100 mm for the parallel section (effective section) and 25 x 160 mm for the overall size. These were then mounted on a tensile testing machine and pulled at a speed of 25 mm / min, and the maximum value of the load was measured as the tensile strength.

[0162] <Needle penetration mark density> The inorganic fiber molded body is peeled from the center of its thickness, and the unit area (1 cm²) of one of the peeled surfaces is measured. 2 The number of needle penetration marks per unit area (1 cm²) of the other delamination surface. 2 The average number of needle penetration marks per unit area was defined as the needle penetration mark density. Note that areas with warp threads were counted as needle penetration marks. In reality, when visible light is shone on one side of an inorganic fiber molded body, the amount of transmitted light at the needle penetration marks is greater than the amount of transmitted light in areas other than the needle penetration marks, so transmitted light is observed on the delamination surface. By counting the number of light spots and warp threads due to transmission to this delamination surface, the total number of needle penetration marks per unit area can be counted.

[0163] The physical properties of the inorganic fiber composite materials of Examples 1 to 20 and the inorganic fiber molded articles of Comparative Examples 1 and 2 are shown in Tables 1 and 2 below.

[0164] [Table 1]

[0165] [Table 2]

[0166] [test] The following particle impact resistance tests were conducted using Examples 1-20 and Comparative Examples 1 and 2.

[0167] <Particle impact resistance> Particle impact resistance was measured by setting a sandblaster (ESCO Corporation's "Sandblaster EA127BK") as follows and ejecting particles of particle size F36 (JIS R6001-1 and JIS R6001-2) (see below) onto a test piece for 20 seconds or more. [Sandblaster settings] Nozzle diameter 8mm Distance from nozzle to test specimen: 350 mm Air pressure 0.48 MPa 〔particle〕 We used "Abrasive Alumina Grains" manufactured by Riken Corundum Co., Ltd.

[0168] <Rating> In the particle impact resistance test, the time it took for the test piece to be penetrated was measured. If penetration occurred in less than 20 seconds, it was evaluated as "penetration," and if it took 20 seconds or more, it was evaluated as "no penetration."

[0169] <Result> The test results are shown in Table 3 below.

[0170] [Table 3]

[0171] The test results showed that Examples 1-20 required more than 20 seconds to penetrate, possessed particle impact resistance, and could withstand the ejected particles even if the battery overheated, maintaining their subsequent fire resistance and flame-blocking performance. Furthermore, it was found that in Examples 18-20, which have particle impact-resistant layers on both sides, the inorganic fiber molded body is not exposed, making it easier to handle and improving the adhesive properties of the back surface. In contrast, Comparative Examples 1 and 2 were found to have low particle impact resistance, and were damaged by particles ejected when the battery overheated, thus failing to maintain fire resistance and flame-blocking performance.

Claims

1. An inorganic fiber composite material comprising a sheet-like inorganic fiber molded body and a particle impact resistant layer on at least one side of the inorganic fiber molded body, wherein the bulk density of the inorganic fiber composite material is 0.100 g / cm³ or more and 0.500 g / cm³ or less, and the material has the following properties. <Particle impact resistance> The performance was demonstrated when a sandblaster with a nozzle diameter of 8 mm, a distance of 350 mm from the nozzle to the test piece, and an air pressure of 0.48 MPa was used, and particle size F36 (JIS R6001-1 and JIS R6001-2) was discharged for 20 seconds without penetration.

2. The inorganic fiber molded article has a basis weight of 1500 g / m². ２ The following, and with a bulk density of 0.1 g / cm³ ３ The inorganic fiber composite material according to claim 1, characterized in that it is as described above.

3. The inorganic fiber composite material according to claim 1, characterized in that the inorganic fiber molded body is a needle blanket containing alumina / silica-based fibers.

4. The inorganic fiber composite material according to claim 1, characterized in that the thickness of the inorganic fiber molded body exceeds 50% of the total thickness of the inorganic fiber composite material.

5. The inorganic fiber composite material according to claim 1, characterized in that the particle impact-resistant layer has a mass of 70% or less of the mass of the inorganic fiber molded body.

6. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer is provided on both sides of the inorganic fiber molded body, and the total mass of the particle impact resistant layer is 140% or less of the mass of the inorganic fiber molded body.

7. The inorganic fiber composite material according to claim 1, characterized in that the thickness of the particle impact-resistant layer is 0.1% or more and 50% or less of the thickness of the inorganic fiber molded body.

8. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer is electrically insulating.

9. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer includes at least an inorganic material.

10. The inorganic fiber composite material according to claim 1, characterized in that the particle impact-resistant layer is directly fixed to the inorganic fiber molded body.

11. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer is bonded to the inorganic fiber molded body.

12. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer is stitched to the inorganic fiber molded body with thread.

13. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer is fixed to the inorganic fiber molded body by adhesive tape.

14. The inorganic fiber composite material according to claim 1, characterized in that the particle impact-resistant layer is in the form of a bag, and an inorganic fiber molded body is enclosed therein.

15. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer is an inorganic fiber woven fabric.

16. The inorganic fiber composite material according to claim 15, characterized in that the inorganic fiber woven fabric is a glass fiber woven fabric.

17. The inorganic fiber composite material according to claim 15, characterized in that the inorganic fiber woven fabric is a basalt fiber woven fabric.

18. The inorganic fiber composite material according to claim 1, characterized in that the particle impact resistant layer is formed by impregnating an inorganic fiber molded body with an organic binder to bond the fibers together.

19. A battery pack cover using an inorganic fiber composite material according to any one of claims 1 to 18, wherein the particle impact-resistant layer side of the inorganic fiber composite material is positioned facing the battery side.

20. A battery pack characterized by having the battery pack cover of claim 19.

21. An electric mobility device characterized by comprising the battery pack of claim 20.

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