Fire spread suppression material

Abstract

Provided is a fire-retardant material that has superior fire-retardant performance compared to known fire-retardant materials. [Solution] The fire spread retardant material comprises a metal plate and a fabric containing flame-retardant fibers as constituent fibers, and has a laminate with a laminated structure of the fabric-the metal plate-the fabric-the metal plate-the fabric, and the total thickness of the metal plates in the laminate is greater than 18 μm and less than 300 μm.

Description

[Technical Field]

[0001] The present invention relates to a fire-retardant material. [Background technology]

[0002] In battery packs such as lithium-ion batteries, a short circuit can cause a cell to heat up to 900°C in a few minutes, resulting in the cell catching fire. To prevent the spread of fire to adjacent cells, fire-retardant material is typically installed between each cell, which has a heat insulating effect and therefore exhibits fire-retardant properties.

[0003] For example, Patent Document 1 (JP 2023-58123 A) describes a "fire-retardant material in which a laminate including a metal plate and / or a carbon plate and a fabric, and a flame-retardant liquid are sealed in a film bag" (Claim 1). Patent Document 1 describes that the number of layers made of metal plate and / or carbon plate in the laminate can be, for example, 1 to 4 layers, preferably 1 layer, and the number of layers made of fabric can be, for example, 1 to 4 layers, preferably 2 layers (paragraph 0022). In particular, it describes that the fire-retardant material preferably includes a laminate in which fabric is superimposed on each of the main surfaces of a metal plate and / or a carbon plate (paragraph 0023). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-58123 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a fire-spread-retardant material that has superior fire-spread-retardant performance compared to known fire-spread-retardant materials. Specifically, an object of the present invention is to provide a fire-spread-retardant material that can delay the transfer of heat released from a ignited cell to adjacent cells in an electrochemical device having multiple cells, such as a battery. [Means for solving the problem]

[0006] This invention relates to the following inventions: [1] A metal plate and a fabric containing flame-retardant fibers as constituent fibers, A fire-retardant material having a laminate including a laminated structure of the fabric, the metal plate, the fabric, the metal plate, and the fabric, A fire-retardant material in which the total thickness of the metal plates in the laminate is greater than 18 μm and less than 300 μm. [2] The fabric contains adhesive fibers as constituent fibers, The fire retardant material of [1], wherein the metal plate and the fabric are bonded together by the adhesive fiber. [3] The fire retardant material of [1], wherein the fabric is present on both main surfaces of the laminate, and the fabric on both main surfaces contains inorganic particles. [4] A fire retardant material for a battery pack, comprising any one of the fire retardants described in [1] to [3]. [Effects of the Invention]

[0007] According to the fire spread retardant material of [1] of the present invention, a laminate having a specific laminated structure, namely, fabric-metal plate-fabric-metal plate-fabric, and by adjusting the total thickness of the metal plates in the laminate to a specific range, namely, greater than 18 μm and less than 300 μm, a fire spread retardant material can be provided that has excellent fire spread retardant performance and flexibility that allows for excellent conformability when inserted into a battery. The laminate has a portion having a fabric-metal plate-fabric-metal plate-fabric stacking configuration, and the total thickness of the metal plates in the laminate is greater than 18 μm, thereby realizing a fire-spread-retardant material that is highly heat-resistant and has excellent fire-spread-retardant performance. Furthermore, the total thickness of the metal plates in the laminate is less than 300 μm, thereby realizing a fire-spread-retardant material that has excellent flexibility and conforms well when inserted into a battery. The fabric contains flame-retardant fibers, so that even when the fire-retardant material is exposed to flames or heat, the fabric is prevented from unintentionally deforming, melting, or burning, and heat resistance is maintained, making it possible to provide a fire-retardant material with excellent fire-retardant performance.

[0008] According to the fire-spread-retardant material of [2], which is one of the preferred embodiments of the present invention, adhesive fibers are included as constituent fibers of the fabric, eliminating the need for a binder and allowing the fabric to have many voids. This allows for many air spaces, making it difficult for fire to spread, and providing a fire-spread-retardant material with excellent fire-spread-retardant performance. Furthermore, because the metal plate and the fabric are bonded together, heat received by the fabric can be uniformly conducted to the metal plate (and similarly, heat received by the metal plate can be uniformly conducted to the fabric). This prevents unintended deformation, melting, or combustion of the fabric, and maintains heat resistance, allowing for the provision of a fire-spread-retardant material with excellent fire-spread-retardant performance.

[0009] According to the fire-spread-retardant material of [3], which is one of the preferred embodiments of the present invention, the fabric containing inorganic particles is present on both main surfaces of the laminate, and therefore the fire-spread-retardant material has main surfaces with excellent heat insulation properties, making it possible to provide a fire-spread-retardant material with improved fire-spread-retardant performance.

[0010] The fire-retardant material for batteries according to the present invention [4] contains any one of the fire-retardant materials according to the above [1] to [3], and therefore can provide a battery pack with excellent fire-retardant performance. DETAILED DESCRIPTION OF THE INVENTION

[0011] The fire-spread suppressing material of the present invention comprises a metal plate and a fabric containing flame-retardant fibers in its constituent fibers, and has a specific laminated structure portion, namely a laminate comprising the fabric - the metal plate - the fabric - the metal plate - the fabric, wherein the total thickness of the metal plates in the laminate is greater than 18 μm and less than 300 μm.

[0012] The metal plate used in the present invention can be made of a metal that is stable at temperatures expected during use of a battery pack equipped with a fire-retardant material (e.g., −40 to 80°C) and has high thermal conductivity. Examples of metal plates include aluminum plates, copper plates, gold plates, silver plates, brass plates, iron plates, and stainless steel plates. These metal plates may be subjected to rust prevention treatments such as painting, wet plating, dry plating, thermal spraying, lamination, and oxidation treatment.

[0013] The size and shape of the metal plates can be determined appropriately depending on the conditions under which the fire-spread-retardant material is used. The total thickness of the metal plates is greater than 18 μm and less than 300 μm. When the total thickness of the metal plates in the laminate is greater than 18 μm, a fire-spread-retardant material with excellent fire-spread-retardant performance can be realized. When the total thickness of the metal plates in the laminate is less than 300 μm, a fire-spread-retardant material with excellent flexibility for conformability when inserted into a battery can be realized. To realize a fire-spread suppression material with superior fire-spread suppression performance, preferably, the lower limit of the total thickness of the metal plates can be 20 μm or more, 50 μm or more, or 100 μm or more. Furthermore, in order to realize a fire-spread suppressing material with even better flexibility for conformability when placed in a battery, preferably the upper limit of the total thickness of the metal plates can be 250 μm or less, 200 μm or less, or 150 μm or less. It is also possible to use a metal plate coated with a filler having high thermal conductivity (for example, graphene, carbon nanotubes, etc.) to increase thermal conductivity.

[0014] The fabric used in this invention can be a fiber sheet containing flame-retardant fibers in its constituent fibers, such as nonwoven fabrics, woven fabrics, knitted fabrics, fiber webs, etc. The fabric is preferably a fiber web or nonwoven fabric having a structure in which a fiber layer in which fibers are oriented in one direction (for example, a direction parallel to the conveying direction) is laminated with a fiber layer in which fibers are oriented in a direction different from the aforementioned direction. Specific examples include a cross-lay web in which unidirectional webs are laminated so that the fiber orientations are different, or a nonwoven fabric prepared using such a fiber web, or a criss-cross web in which unidirectional webs and cross-lay webs are laminated, or a nonwoven fabric prepared using such a fiber web. Alternatively, a random web without a specific fiber orientation, or a nonwoven fabric prepared using such a fiber web, is preferred. By using a fabric having such a fiber orientation, even when the fire-retardant material is exposed to flame or heat, heat can be efficiently transferred from the fabric to the entire metal plate. As a result, unintended deformation, melting, or combustion of the fabric is prevented, and heat resistance can be maintained, which is preferable because a fire-retardant material with excellent fire-retardant performance can be provided.

[0015] As the fabric, a nonwoven fabric is preferred because it has gaps between the fibers and is excellent in heat insulation. The manner in which the constituent fibers of the nonwoven fabric are integrated with each other can be appropriately adjusted, and may be an embodiment in which the constituent fibers are integrated by simply entanglement without bonding (specific examples include hydroentangled nonwoven fabrics and needle-punched nonwoven fabrics), an embodiment in which the constituent fibers are integrated by bonding with a binder or the like, or an embodiment in which some or all of the adhesive fibers contained in the constituent fibers are melted and the constituent fibers are integrated by fiber bonding. In particular, the absence of a binder or the like can prevent unintended deterioration of fire spread suppression performance. Therefore, it is preferable to use a nonwoven fabric in which the constituent fibers are integrated by simply entanglement without bonding, or a nonwoven fabric in which the constituent fibers are integrated by fiber bonding. In particular, if some or all of the adhesive fibers contained in the fabric melt and the constituent fibers bond together to form a single unit, the fabric can have many voids. This allows for a large air layer, making it difficult for fire to spread, and thus providing a fire-inhibiting material with excellent fire-spread suppression performance, which is preferable. Furthermore, if the metal plate and the fabric are also bonded together by this fiber bonding, the heat received by the fabric can be uniformly transferred to the metal plate. Therefore, unintended deformation, melting, or combustion of the fabric is prevented, and heat resistance can be maintained, thus providing a fire-inhibiting material with excellent fire-spread suppression performance, which is preferable.

[0016] The characteristics of the aforementioned fabric, such as its weight and thickness, can be appropriately adjusted to provide a fire-spread suppression material with superior fire-spread suppression performance. 2 The mass per square meter is 10-500 g / m². 2 Preferably, it is 20-250 g / m 2 It is more preferable that the thickness of the fabric is 0.05 to 10 mm, and more preferably 0.1 to 1.5 mm. In this invention, the thickness (for example, the thickness of a fabric, metal plate, or laminate) refers to the arithmetic mean of five thicknesses measured using a thickness measuring instrument (Dial Thickness Gauge 0.01 mm Type H, manufactured by Ozaki Seisakusho Co., Ltd.).

[0017] The type of fiber constituting the fabric can be selected as appropriate, but flame-retardant fibers (flame-retardant fibers) are used so that the fabric is less susceptible to fire spread, thereby providing a fire-retardant material with excellent fire-retardant performance. The term "flame-retardant fiber" as used herein refers to a fiber composed of resins or inorganic components that have an LOI (Limited Index of Intake) of 26 or higher, as determined based on JIS K7201. Furthermore, to provide a flame-spread suppression material with superior fire-spread suppression performance, it is preferable that the fibers constituting the fabric be flame-retardant fibers composed solely of the aforementioned resins and inorganic components. The type of flame-retardant fiber is not limited, and examples that can be used include acrylic fibers such as oxidized acrylic fibers, polyphenylene sulfide (PPS) fibers, aramid fibers, flame-retardant viscose fibers, flame-retardant polyester fibers, inorganic fibers, etc. The fabric may contain fibers other than flame-retardant fibers as constituent fibers. The fineness and fiber length of the constituent fibers, such as the flame-retardant fibers, contained in the fabric are not particularly limited, but the fineness is preferably 0.1 to 15 dtex, more preferably 0.5 to 10 dtex, and the fiber length is preferably 10 to 100 mm, more preferably 20 to 80 mm.

[0018] The number of layers made of metal plates or layers made of fabric is not limited in a laminate containing a metal plate and a fabric, as long as the laminate has a laminate structure of fabric-metal plate-fabric-metal plate-fabric. The number of layers made of metal plates can be, for example, 1 to 4, preferably 1, and the number of layers made of fabric can be, for example, 1 to 4. Note that a layer made of fabric means a layer made of fabric. Therefore, a portion formed by stacking fabrics (for example, a portion formed by two overlapping fabrics) is considered to have one layer of fabric. Similarly, a layer made of metal plate means a layer made of metal plate. Therefore, a portion formed by stacking metal plates (for example, a portion formed by two overlapping metal plates) is considered to have one layer of metal plate.

[0019] The lamination mode is adjusted appropriately, and the laminate may be one in which one or more sheets of fabric are superimposed on each of the two main surfaces of a metal plate. However, the laminate may be one in which both main surfaces of a metal plate are wrapped with fabric once or multiple times, or one in which both main surfaces of a metal plate are sandwiched between fabrics. In this case, the laminate is one in which one or more sheets of fabric are superimposed on each of the two main surfaces of a metal plate. In particular, it is preferable that the fire-spread-retardant material includes a laminate in which fabric is superimposed on each of the two main surfaces of a metal plate, since this makes it possible to provide a fire-spread-retardant material with even more excellent fire-spread-retardant performance.

[0020] The fire-spread suppressing material of the present invention has the fabric present on both main surfaces of the laminate, and it is preferable that the fabric on both main surfaces contains inorganic particles. The inorganic particles are stable at the temperature expected when a battery pack equipped with the fire-spread suppressing material is used (e.g., -40 to 80°C), and are preferably non-combustible particles. Therefore, they can be evenly or unevenly distributed within the fabric, insulating the heat applied to the fire-spread suppressing material and suppressing the overall temperature rise of the fire-spread suppressing material. The type of inorganic particles is not particularly limited, but it is preferable to use particles with low thermal conductivity or high specific heat. Examples of particles with low thermal conductivity include silica particles and silica aerogel particles. Examples of particles with high specific heat include metal oxide particles such as aluminum hydroxide particles. The inorganic particles may be solid inorganic particles or hollow inorganic particles. The average particle size of the inorganic particles that can be used in the present invention can be appropriately selected, and for example, inorganic particles with an average particle size of 0.01 μm to 2.0 mm can be used.

[0021] The amount of inorganic particles contained in the fabric can be 0 to 80 parts by mass, 0.3 to 70 parts by mass, or 0.75 to 60 parts by mass per 100 parts by mass of fabric. The method of impregnating the fabric with inorganic particles can be appropriately selected, and methods such as impregnating the fabric with a dispersion of inorganic particles or coating one main surface of the fabric with the dispersion can be employed. It is preferable that a larger amount of inorganic particles is supported in the fire-spread suppressor to provide a fire-spread suppressor with better heat insulation properties. Furthermore, it is preferable that the fire-spread suppressor has a structure in which a larger amount of inorganic particles are present on the main surface side closer to the heat source, thereby providing a fire-spread suppressor with better heat insulation properties.

[0022] The fire spread suppressant according to the present invention can be used on its own, but it may also be used as a fire spread suppressant laminated with other components. Other components that can be used include non-porous films, porous films, or foams that are breathable or non-breathable, in addition to the fabrics and metal plates according to the present invention.

[0023] The fire-spread suppressing material of the present invention can be used in a manner in which it is sealed in a film bag. The manner in which it is sealed can be selected as appropriate, but for example, it can be sealed in a laminated film bag made of laminated organic resin film, or the surface can be laminated or packaged with organic resin film.

[0024] The fire-retardant material of the present invention is not limited to the following, but may be, for example: (1) A process of preparing a metal plate and a fabric containing flame-retardant fibers in its constituent fibers; (2) laminating the metal plate and the fabric to prepare a laminate having a laminated structure of fabric-metal plate-fabric-metal plate-fabric; The composition can be produced by a production method including the steps of:

[0025] One preferred embodiment of the present invention is a fire-spread suppressing material in which the fabric contains adhesive fibers as constituent fibers, and is not limited to the following, but for example, instead of step (1), (1') A process of preparing a metal plate and a fabric containing flame-retardant fibers and adhesive fibers in its constituent fibers; and, following the step (1') and the step (2), (3') A step of heating the laminate to melt the adhesive fibers, thereby bonding the constituent fibers together and integrating them, and bonding the fabric to the metal plate with the melted adhesive fibers; The composition can be produced by a production method including the steps of:

[0026] The heating temperature and heating time in the heat treatment of step (3') can be appropriately determined depending on the adhesive fiber used, but typically, it is heated at 160°C for 0.1 hours and then cooled. [Example]

[0027] The present invention will be specifically described below with reference to examples, but these examples are not intended to limit the scope of the present invention.

[0028] The fire spread suppression performance of the fire spread suppression material of the present invention was evaluated by the method described below. (Evaluation of fire spread suppression performance (burner test)) The ambient temperature for the measurement was set to 20-25°C, and the temperatures of the fire-suppressing material and thermocouples A and B used in the measurement were also set to 20-25°C before starting the following measurements. (1) The fire spread suppressant was installed upright so that one of its main surfaces was parallel to the direction of gravity. (2) Thermocouple A was installed at the center of one of the main surfaces of the fire-retardant material, and thermocouple B was installed at the center of the other main surface of the fire-retardant material. Thermocouple A was 6 mm away from one of the main surfaces of the fire-retardant material, and thermocouple B was in contact with the other main surface of the fire-retardant material. (3) A burner was installed so that the flame could act perpendicularly to the center of one of the main surfaces of the fire-spread suppression material. (4) A flame was emitted from the burner and directed perpendicularly to the center of one of the main surfaces of the fire-retardant material. The burner was brought close to the fire-retardant material so that the temperature measured by thermocouple A, which was installed between the burner and the fire-retardant material, reached 900°C. (5) A flame was applied perpendicularly to the center of one of the main surfaces of the fire retardant material, and the temperature measured by thermocouple B 10 minutes after the temperature measured by thermocouple A reached 900°C (i.e., the temperature at the center of the other main surface of the fire retardant material at that time) was confirmed. In addition, the lower the temperature of the fire-spread-retardant material measured at thermocouple B after 10 minutes, the higher the heat insulating effect and the more excellent the fire-spread-retardant performance, and the more likely the fire-spread-retardant material is to be evaluated.

[0029] As is evident from the findings disclosed in Figure 1 of "Thermal Runaway Mechanism and High-Safety Technology of Lithium-Ion Batteries (Surface Technology, Vol. 70, No. 6, pp. 301-307, Mukai Takashi, Sakai Tetsuo, Yanagida Masahiro)," in order to prevent decomposition of the positive electrode and suppress thermal runaway, the cells of a battery pack must be insulated to prevent temperatures exceeding 300°C. Based on this finding, in the present invention, if the temperature measured by Thermocouple B, which is located between the fire-retardant material and the point where the flame (heat source) acts, is 300°C or lower 10 minutes later, the fire-retardant material is deemed to have excellent fire-retardant performance and is marked with a "◯" in the table. On the other hand, if the temperature measured by Thermocouple B 10 minutes later is higher than 300°C, the fire-retardant material is deemed to have poor fire-retardant performance and is marked with an "X" in the table.

[0030] Next, the embrittlement of the fire-spread suppression material after being subjected to the above-mentioned (evaluation of fire-spread suppression performance (burner test)) was evaluated using the evaluation method described below. (Confirmation of embrittlement after burner test) In the (evaluation of fire spread suppression performance (burner test)), the fire spread suppression material used for the test was collected 10 minutes after the temperature measured by thermocouple A reached 900°C. The collected fire spread suppression material was allowed to cool, and the center of the main surface on one side that had been exposed to the flame was visually inspected. Upon inspection, it was determined that the fire-spread suppressant material in which the center of one of the main surfaces was burned and a through-hole had formed was embrittlement and easily combustible. Fire-spread suppressants with such physical properties were marked with an "×" in the table. On the other hand, fire-spread suppressants in which the center of one of the main surfaces was not burned and there were no through holes in the fire-spread suppressant were evaluated as being less prone to embrittlement and less prone to burning. Fire-spread suppressants with such physical properties were marked with a "○" in the table. The embrittlement of fire-retardant materials occurs when thermal energy is difficult to dissipate from the area of ​​the material that is exposed to flame. Therefore, fire-retardant materials that are evaluated as being difficult to embrittle and burn are thought to have been able to conduct heat evenly from the fabric to the metal plate (and similarly, from the metal plate to the fabric).

[0031] Furthermore, the flexibility of the fire spread suppression material was evaluated using the evaluation method described below. (Evaluation of flexibility) A rectangular sample (long side: 80 mm, short side: 10 mm) was taken from the fire retardant material. The sample was subjected to the measurement method described in 9.1 Bending stress of JIS K7171:2022 "Plastics - Determination of bending properties" to determine the bending stress (unit: MPa / 80 mm). The obtained bending stress was then converted to N units (unit: N / 80 mm), and the obtained value was used as the bending load (unit: N / 80 mm) of the fire retardant material. Fire spread suppressants with a bending load of 4.4 N / 80 mm or higher required significant force to bend, making it difficult to insert and fill them between the cells of a battery pack. Therefore, these were evaluated as fire spread suppressants lacking flexibility. Fire spread suppressants with such physical properties are marked with an "×" in the table. On the other hand, fire-retardant materials with a bending load of less than 4.4 N / 80 mm did not require a strong force to bend, and were easy to insert and fill between the cells of the battery pack. Therefore, they were evaluated as fire-retardant materials with excellent flexibility. Fire-retardant materials with such physical properties are marked with a "○" in the table.

[0032] Example 1 (Prepare the fabric) A unidirectional web was prepared by feeding 90% by mass of flame-retardant oxidized acrylic fiber (fineness: 2.2 dtex, fiber length: 51 mm, LOI value: 50-60) and core-sheath adhesive fiber (fineness: 1.7 dtex, fiber length: 38 mm) with a core of polypropylene resin and a sheath of modified polyethylene resin into a carding machine, and the unidirectional web was then folded over to prepare a crosslay web. Next, a crisscrosslay web was prepared by laminating a unidirectional web and a crosslay web. Then, by subjecting this crisscrosslay web to a water-jet entanglement device, a water-jet entangled nonwoven fabric (thickness: 0.9 mm, basis weight: 80 g / m²) was formed. 2 ) was prepared. The prepared fiber-bonded nonwoven fabric was punched out to prepare rectangular fabric pieces (thickness: 0.9 mm, length: 150 mm, width: 100 mm).

[0033] (Preparing the metal plate) Rectangular aluminum plates (length: 150 mm, width: 100 mm) of different thicknesses were prepared: 9 μm, 12 μm, 35 μm, and 60 μm.

[0034] (Comparative Example 1) A rectangular piece of fabric and an aluminum plate were layered in the following order: one rectangular piece of fabric - one aluminum plate (thickness: 12 μm) - one rectangular piece of fabric (three-layer structure). This layered structure was then supplied to Reliant, and only the sheath portion of the core-sheath adhesive fibers was melted. This process bonded the constituent fibers together, creating a unified structure, and the sheath portion also bonded the rectangular fabric to the aluminum plate. In this way, a fire spread suppression material (three-layer structure, thickness: 0.9 mm, basis weight: 193 g / m²) was created. 2 ) was prepared.

[0035] (Comparative Example 2) A fire retardant material (three-layer structure, thickness: 0.9 mm, basis weight: 255.7 g / m) was prepared in the same manner as in Comparative Example 1, except that an aluminum plate of a different thickness (thickness: 35 μm) was used instead of the aluminum plate (thickness: 12 μm). 2 ) was prepared.

[0036] Example 1 A rectangular piece of fabric and an aluminum plate were layered in the following order: one rectangular piece of fabric - one aluminum plate (thickness: 12 μm) - one rectangular piece of fabric - one aluminum plate (thickness: 12 μm) - one rectangular piece of fabric (five-layer structure). This layered structure was then supplied to Reliant, and only the sheath portion of the core-sheath adhesive fibers was melted. This process bonded the constituent fibers together, creating a unified structure, and the sheath portion also bonded the rectangular fabric to the aluminum plate. In this way, a fire spread suppression material (five-layer structure, thickness: 1.2 mm, basis weight: 306 g / m²) was created. 2 ) was prepared.

[0037] (Comparative Example 3) The rectangular fabric and aluminum plate were stacked in the following order (five-layer structure): one rectangular fabric - one aluminum plate (9 μm) - one rectangular fabric - one aluminum plate (9 μm) - one rectangular fabric, and then supplied to Reliant. Only the sheath of the core-sheath adhesive fiber was melted. This resulted in the constituent fibers being bonded together and the rectangular fabric being bonded to the aluminum plate by the sheath. In this way, a fire retardant (three-layer structure, thickness: 1.2 mm, basis weight: 289.6 g / m) was produced. 2 ) was prepared.

[0038] [Table 1]

[0039] The fire-retardant material of Comparative Example 1 reached a high temperature after 10 minutes in the burner test, and was embrittled and prone to combustion. Therefore, it was evaluated as a fire-retardant material with poor fire-retardant performance. Furthermore, in order to realize a fire-spread-retardant material with excellent fire-spread-retardant performance, an attempt was made to create Comparative Example 2 (metal plate thickness: 35 μm) in which the metal plate was thicker than that of Comparative Example 1 (metal plate thickness: 12 μm). However, the fire-spread-retardant material of Comparative Example 2 also reached a high temperature after 10 minutes as measured in the burner test, and was embrittled and prone to combustion. Therefore, it was evaluated as a fire-spread-retardant material with poor fire-spread-retardant performance.

[0040] In contrast, the fire-spread-retardant material of Example 1, although the metal plate was thinner than the fire-spread-retardant material of Comparative Example 2, reached a lower temperature after 10 minutes in the burner test than Comparative Example 2 (and Comparative Example 1). Furthermore, it was not embrittled and was difficult to burn. Therefore, it was evaluated as a fire-spread-retardant material with excellent fire-spread-retardant performance. The reason for this is thought to be that the fire-spread-retardant material of Example 1 has a laminated structure according to the present invention (a laminated structure of fabric-metal plate-fabric-metal plate-fabric).

[0041] On the other hand, the fire-spread-retardant material of Comparative Example 3, in contrast to Example 1, had a laminated structure according to the present invention, but the temperature reached after 10 minutes measured in the burner test was high, and the material was embrittled and prone to combustion. Therefore, it was evaluated as a fire-spread-retardant material with poor fire-spread-retardant performance. From these comparison results, it was revealed that in order to realize a fire-spread-retardant material with excellent fire-spread-retardant performance, the total thickness of the metal plates in the laminate having the laminated structure must be greater than 18 μm.

[0042] (Preparing the film) A PET / EVA film (laminate film) with a thickness of 100 μm (length: 155 mm, width: 105 mm) was prepared.

[0043] Example 2 The rectangular fabric and aluminum plate were laminated in the following order (five-layer structure): one rectangular fabric, one aluminum plate (60 μm), one rectangular fabric, one aluminum plate (35 μm), and one rectangular fabric. The laminate was then sandwiched between PET / EVA films and fed to the Reliant, where only the sheath of the core-sheath adhesive fiber was melted. This bonded the constituent fibers together and integrated them, and the sheath also bonded the rectangular fabric to the aluminum plate. The laminate with a five-layer structure prepared in this way is sealed by heat sealing all four sides, and the fire-spread suppressant (five-layer structure, thickness: 1.2 mm, basis weight: 717.7 g / m²) is enclosed in a film bag. 2 ) was prepared.

[0044] Example 3 The rectangular fabric and aluminum plate were laminated in the following order (five-layer structure): one rectangular fabric, one aluminum plate (60 μm), one rectangular fabric, one aluminum plate (60 μm), and one rectangular fabric. The laminate was then sandwiched between PET / EVA films and fed to the Reliant furnace, where only the sheath of the core-sheath adhesive fiber was melted. This bonded the constituent fibers together and integrated them, and the sheath also bonded the rectangular fabric to the aluminum plate. The four sides of the five-layer laminate thus prepared were heat-sealed to seal the laminate, and the fire retardant material (five-layer structure, thickness: 1.2 mm, basis weight: 787 g / m) enclosed in a film bag was placed on the laminate. 2 ) was prepared.

[0045] [Table 2]

[0046] The fire-retardant materials of Examples 2 and 3 were all evaluated as fire-retardant materials with excellent fire-retardant performance.

[0047] (Loading of inorganic particles onto fabric) The fiber-bonded nonwoven fabric was impregnated with a dispersion of silica particles in water. After that, it was dried to remove the water, and the fiber-bonded nonwoven fabric had a weight of 80 g / m 2 Heat insulating paint nonwoven fabric (basis weight: 160g / m) carrying silica particles 2 ) was prepared. The prepared heat insulating coating nonwoven fabric was punched out to prepare rectangular heat insulating coating fabrics (thickness: 1.2 mm, length: 150 mm, width: 100 mm).

[0048] Example 4 A rectangular piece of fabric, an aluminum plate, and a rectangular piece of heat-insulating painted fabric were laminated in the following order (five-layer structure): one piece of rectangular heat-insulating painted fabric - one piece of aluminum plate (35 μm) - one piece of rectangular fabric - one piece of aluminum plate (35 μm) - one piece of rectangular heat-insulating painted fabric. The layers were then sandwiched between PET / EVA films and subjected to Reliant, where only the sheath portion of the core-sheath adhesive fibers was melted. This bonded the constituent fibers together, creating a unified structure, and the sheath portion bonded the rectangular fabric and rectangular heat-insulating painted fabric to the aluminum plate. The four sides of the five-layer laminate thus prepared were heat-sealed to seal the laminate, and the fire retardant material (five-layer structure, thickness: 1.1 mm, basis weight: 808.4 g / m) enclosed in a film bag was placed on the laminate. 2 ) was prepared.

[0049] Example 5 A rectangular fabric, an aluminum plate, and a rectangular insulating fabric were layered in the following order (five-layer structure): one rectangular insulating fabric, one aluminum plate (60 μm), one rectangular fabric, one aluminum plate (60 μm), and one rectangular insulating fabric. The resulting structure was then sandwiched between PET / EVA films and fed to the Reliant furnace, where only the sheath of the core-sheath adhesive fiber was melted. This bonded the constituent fibers together and integrated them, and the sheath also bonded the rectangular fabric and the rectangular insulating fabric to the aluminum plate. The four sides of the five-layer laminate thus prepared were heat-sealed to seal the laminate, and the fire retardant material (five-layer structure, thickness: 1.2 mm, basis weight: 947 g / m) enclosed in a film bag was placed on the laminate. 2 ) was prepared.

[0050] Example 6 A rectangular fabric, an aluminum plate, and a rectangular insulating fabric were layered in the following order (nine layers): one rectangular insulating fabric, one aluminum plate (60 μm), one rectangular fabric, one aluminum plate (60 μm), one rectangular fabric, one aluminum plate (60 μm), one rectangular fabric, one aluminum plate (60 μm), and another rectangular insulating fabric. The resulting structure was then sandwiched between PET / EVA films and fed to a Reliant furnace, where only the sheath of the core-sheath adhesive fiber was melted. This bonded the constituent fibers together and integrated them, and the sheath also bonded the rectangular fabric and the rectangular insulating fabric to the aluminum plate. The four sides of the nine-layer laminate thus prepared were heat-sealed to seal the laminate, and the fire retardant material (nine-layer structure, thickness: 2.1 mm, basis weight: 1437 g / m) enclosed in a film bag was placed on the laminate. 2 ) was prepared.

[0051] Comparative Example 4 The rectangular fabric, aluminum plate, and rectangular insulating fabric were layered in the following order (1 rectangular insulating fabric - 1 aluminum plate (60μm) - 1 rectangular fabric - 1 aluminum plate (60μm) - 1 rectangular fabric - 1 aluminum plate (60μm) - 1 rectangular fabric - 1 aluminum plate (60μm) - 1 rectangular fabric - 1 aluminum plate (60μm) - 1 rectangular insulating fabric (1 rectangular insulating fabric) (an eleven-layer structure), then sandwiched between PET / EVA films and fed to the Reliant, where only the sheath of the core-sheath adhesive fiber was melted. This bonded the constituent fibers together and integrated them, and the sheath also bonded the rectangular fabric and rectangular insulating fabric to the aluminum plate. The laminate having a 11-layer structure prepared in this way is sealed by heat sealing all four sides, and the fire-spread suppressant (11-layer structure, thickness: 2.6 mm, basis weight: 1682 g / m²) is enclosed in a film bag. 2 ) was prepared.

[0052] [Table 3]

[0053] The fire-spread-retardant materials of Examples 4 to 6 and Comparative Example 4 were all evaluated as having excellent fire-spread-retardant performance. However, the fire-spread-retardant material of Comparative Example 4 was evaluated as having inferior flexibility compared to Examples 4 to 6. This comparison result revealed that in order to achieve a fire-spread-retardant material with excellent flexibility, the total thickness of the metal plates in the laminate must be less than 300 μm. [Industrial Applicability]

[0054] The fire-spread suppressing material of the present invention can be used in technical fields where it is necessary to block flames, such as battery packs including lithium-ion batteries, as well as heating appliances, building materials, clothing, and camping equipment. It can also be used as a heat dissipation material.

Claims

1. The device has a metal plate and a fabric containing flame-retardant fibers as constituent fibers, A fire-retardant material having a laminated body including a laminated structure of the fabric, the metal plate, the fabric, the metal plate, and the fabric, A fire-retardant material in which the total thickness of the metal plates in the laminate is greater than 18 μm and less than 300 μm.

2. The fabric contains adhesive fibers as constituent fibers, The fire-retardant material according to claim 1 , wherein the metal plate and the fabric are bonded together by the adhesive fibers.

3. The fire-retardant material according to claim 1 , wherein the fabric is present on both main surfaces of the laminate, and the fabric on both main surfaces contains inorganic particles.

4. A fire-retardant material for a battery pack, comprising the fire-retardant material according to any one of claims 1 to 3.

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