Resin molded body and method for manufacturing the same

Abstract

To provide a resin composition which can suppress melting, deformation and fluidization due to jet of high temperature gas and flame, a resin molding using the same, and a method for producing a resin composition.SOLUTION: A resin composition contains, with respect to 100 pts.mass of the whole resin composition, 59 pts.mass or more and 88 pts.mass or less of a thermoplastic resin, 1 pts.mass or more and 18 pts.mass or less of carbon fibers, and 0.3 pts.mass or more and 7 pts.mass or less of a silane coupling agent, wherein the carbon fibers are isotropic pitch-based carbon fibers.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention provides a fire-resistant resin composition. Things Resin molded body and resin used Molded body This relates to a method for producing the above. [Background technology]

[0002] In recent years, in order to reduce the weight of various devices, the exterior bodies of components that were previously made of metal are increasingly being made of resin materials. For example, the exterior bodies of lithium-ion secondary batteries (hereinafter sometimes referred to as "batteries") are increasingly being made of resin materials to reduce weight. For this reason, resin materials with excellent formability, such as the ability to be molded to fit the outer shape of the object to be molded, are being sought.

[0003] On the other hand, as batteries that use resin materials become smaller and have higher energy densities (energy densities of 300Wh / kg or more), there is a risk that they may become too hot due to heat generation depending on how they are used. For this reason, safety in batteries and battery packs is becoming more important. However, improving safety (fire resistance) can sometimes result in poor moldability, so there is a demand for both safety and moldability.

[0004] For example, lithium-ion secondary batteries may experience thermal runaway if they are overcharged or overdischarged, or if an unexpected shock causes an internal or external short circuit. When thermal runaway occurs, a lithium-ion secondary battery generates gas, increasing the battery's internal pressure. Because this situation could lead to the explosion of the outer casing due to the increased internal pressure, these batteries are equipped with vent holes or safety valves to release the gas.

[0005] However, when a lithium-ion secondary battery experiences thermal runaway, high-temperature flames and high-temperature, high-pressure gases are ejected from the gas vent holes and safety valves, with temperatures sometimes reaching a maximum of 999°C, raising concerns that this could cause deformation or melting of the resin material.In addition, if a lithium-ion secondary battery is exposed to an external flame in the event of a car fire, the external heat could cause high-temperature, high-pressure flames to be ejected from the lithium-ion secondary battery, potentially causing secondary damage to the crew and surrounding components.

[0006] As an example of a resin material that can suppress deformation and melting due to such flames and high-temperature gas ejection while improving moldability, Patent Document 1 discloses a resin molding material that improves warpage of molded products by adding specific fibers. Furthermore, Patent Document 2 discloses a polyphenylene sulfide resin composition containing carbon fibers that have been pretreated with a silane coupling agent. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-119405 [Patent Document 2] Japanese Patent Application Publication No. 06-49362 Summary of the Invention [Problem to be solved by the invention]

[0008] However, with the recent trend toward higher energy densities in batteries, the flame output generated during thermal runaway has become significantly larger. It is said that when lithium-ion secondary batteries, which have rapidly become widespread in recent years, ignite, the flame reaches approximately 1000°C. Even the product safety standard (UL standard) established by the Underwriters Laboratories of the United States only evaluates melting and deformation due to flame using a flame with an output of 500 W. Therefore, even the resin compositions disclosed in Patent Documents 1 and 2 may not be able to achieve both moldability, melting, and fluidization under conditions where the flame temperature exceeds 1000°C.

[0009] On the other hand, resin compositions that have been blended with halogen-based flame retardants to enhance their flame retardancy may generate harmful substances such as halogen-containing gases when burned, so there is a demand for flame-retardant resin compositions that do not contain halogen-based materials.

[0010] The present invention has been made in view of the above background, and provides a resin composition that can suppress melting, deformation, and fluidization due to the injection of high-temperature gas or flame, and also has good moldability. Things Resin molded body and resin used Molded body The object of the present invention is to provide a method for producing the above-mentioned compound. [Means for solving the problem]

[0011] The inventors have discovered that by using a resin composition made from a material containing a thermoplastic resin, carbon fiber, and a silane coupling agent, setting the content ratio of these components within a specific range, and selectively using isotropic pitch-based carbon fiber as the carbon fiber, it is possible to suppress the amount of melt deformation when exposed to a flame of 1000°C or higher, and also to achieve good moldability.

[0012] In order to solve the above problems, the present invention proposes the following means. That is, the resin composition of the present invention is characterized in that it contains, relative to 100 parts by mass of the entire resin composition, 59 parts by mass or more and 88 parts by mass or less of thermoplastic resin, 1 part by mass or more and 18 parts by mass or less of carbon fiber, and 0.3 parts by mass or more and 7 parts by mass or less of silane coupling agent, and the carbon fiber is an isotropic pitch-based carbon fiber.

[0013] According to the present invention, when the entire resin composition is taken as 100 parts by mass, the resin composition contains 59 parts by mass or more and 88 parts by mass or less of thermoplastic resin, 1 part by mass or more and 18 parts by mass or less of carbon fiber, and 0.3 parts by mass or more and 7 parts by mass or less of silane coupling agent, and by using isotropic pitch-based carbon fiber as the carbon fiber, it is possible to obtain a resin composition that has improved resistance to melt deformation and can suppress melt deformation and fluidization even when exposed to flames of, for example, about 1000°C.

[0014] In the present invention, the thermoplastic resin may contain at least one of polyphenylene sulfide, polyamide, polybutylene terephthalate, modified polyphenylene ether, and polycarbonate.

[0015] In the present invention, the silane coupling agent may be at least one of an organosilicon compound and a siloxane compound.

[0016] In the present invention, the organosilicon compound may be at least one of an amine-based silane coupling agent and an epoxy-based silane coupling agent.

[0017] In the present invention, the thermoplastic resin may further contain glass fibers in an amount of 3 parts by mass or more and 35 parts by mass or less relative to 100 parts by mass of the thermoplastic resin.

[0018] The resin molded article of the present invention is a resin molded article obtained by molding the resin composition described in each of the above items.

[0019] In the present invention, the protective film may be attached to the outer periphery of one or more lithium ion secondary battery cells having a safety valve or a vent hole so as to cover at least the safety valve or the vent hole.

[0020] The method for producing a resin composition of the present invention is a method for producing a resin composition as described in each of the above items, and is a method for producing a resin composition as described in any one of claims 1 to 4, characterized in that it comprises a silane coupling agent addition step in which the entire amount of the silane coupling agent is dropped into a portion of the thermoplastic resin separated from 100 parts by mass of the thermoplastic resin in a range of 4 parts by mass to 77 parts by mass to obtain a portion of the thermoplastic resin to which the silane coupling agent has been added, a first mixing step in which 23 parts by mass to 96 parts by mass of the remaining thermoplastic resin is added and mixed with the portion of the thermoplastic resin to which the silane coupling agent has been added to obtain an intermediate mixture in which the silane coupling agent and the entire amount of the thermoplastic resin are mixed, and a second mixing step in which the entire amount of the carbon fiber is added to the intermediate mixture and further mixed to obtain the resin composition. [Effects of the Invention]

[0021] As described above, according to the present invention, a resin composition capable of suppressing melting, deformation, and fluidization due to the injection of high-temperature gas or flame is provided. Things Resin molded body and resin used Molded body It is possible to provide a method for producing the above-mentioned [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view of a lithium ion secondary battery cell to which a resin molded article according to one embodiment of the present invention is attached. [Figure 2] FIG. 2 is a perspective view showing a resin molded body according to one embodiment of the present invention and a lithium ion secondary battery cell to which the resin molded body is attached. [Figure 3] FIG. 3 is a perspective view of a lithium ion secondary battery cell to which the resin molded body of FIG. 2 is attached. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] A resin composition according to one embodiment of the present invention and a resin molded article using the same will be described in detail below with reference to the drawings as appropriate. The drawings used in the following description may show characteristic portions enlarged for the sake of clarity, and the dimensional ratios of each component may differ from the actual ratios. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. The present invention can be implemented by making appropriate changes within the scope of its effects.

[0024] (Resin composition) A resin composition according to one embodiment of the present invention is composed of a mixture of a thermoplastic resin, carbon fiber, and a silane coupling agent, and may further contain glass fiber as required. The resin composition of this embodiment contains, relative to 100 parts by mass of the entire resin composition, 59 parts by mass or more and 88 parts by mass or less of thermoplastic resin, 1 part by mass or more and 18 parts by mass or less of carbon fiber, and 0.3 parts by mass or more and 7 parts by mass or less of silane coupling agent. Furthermore, the thermoplastic resin may further contain glass fibers in an amount of 3 parts by mass or more and 35 parts by mass or less relative to 100 parts by mass of the thermoplastic resin.

[0025] Examples of thermoplastic resins used in the resin composition include polyphenylene sulfide (PPS), polyamide 6 (PA6), polybutylene terephthalate (PBT), modified polyphenylene ether (mPPE), polycarbonate (PC), and polypropylene (PP), either alone or in combination.

[0026] Among these, PPS is particularly preferred as a thermoplastic resin due to its high melting point (278°C) and glass transition temperature (92 to 126°C). PPS, a thermoplastic resin suitable for resin compositions, can be either an oxidatively crosslinked PPS, which has been heat-treated in the presence of oxygen to increase its melt viscosity, or a linear PPS, which has been polymerized to increase its molecular weight while maintaining its linear structure by adding lithium chloride, an organic acid salt, water, or the like. It is also possible to use a mixture of an oxidatively crosslinked PPS and a linear PPS.

[0027] As the carbon fiber, among pitch-based carbon fibers using pitch, isotropic pitch-based carbon fiber having optical isotropy is used. By using isotropic pitch-based carbon fiber, the deformation resistance of the resin composition can be improved. Specific examples of the shape of the isotropic pitch-based carbon fibers used in the resin composition include a single fiber diameter of 1 to 20 μm, an average fiber length of 0.01 to 10 mm, and an aspect ratio of about 1.5 to 1,300.

[0028] The silane coupling agent contained in the resin composition can prevent the resin composition from melting and dropping during combustion. The silane coupling agent contained in the resin composition may be, for example, at least one of an organic silicon compound and a siloxane compound.The silane coupling agent may be at least one of an amine-based silane coupling agent and an epoxy-based silane coupling agent.Comparing the amine-based silane coupling agent and the epoxy-based silane coupling agent, the amine-based silane coupling agent having an amino terminal is more preferred.

[0029] Examples of amine-based silane coupling agents include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine.

[0030] Examples of epoxy-based silane coupling agents include 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0031] Furthermore, various silane coupling agents such as acrylic (e.g., 3-acryloxypropyltrimethoxysilane), vinyl, methacrylic, styryl, ureido, isocyanate, isocyanurate, and mercapto silane coupling agents can also be used as the silane coupling agent contained in the resin composition.

[0032] In addition to the above-mentioned amine-based silane coupling agents, epoxy-based silane coupling agents, and liquid silane coupling agents such as acrylic, vinyl, methacrylic, styryl, ureido, isocyanate, isocyanurate, and mercapto-based agents, solid silane coupling agents can also be used as the silane coupling agent.

[0033] An example of a solid silane coupling agent is X-12-1273ES (manufactured by Shin-Etsu Chemical Co., Ltd.). When comparing liquid silane coupling agents with solid silane coupling agents, liquid silane coupling agents are superior in that they have functional groups and are reactive (in principle, high effectiveness can be expected), while solid silane coupling agents are superior in that they are easy to handle.

[0034] When the resin composition contains glass fibers, the glass fibers used may be either filaments (long fibers: glass fibers) or staples (short fibers: glass wool).

[0035] The resin composition of this embodiment may further contain a fluororesin. Examples of fluororesins include polytetrafluoroethylene (PTFE). It is preferable to use PTFE in a powder state. For example, PTFE has an average particle size of 10 to 30 μm and a specific surface area measured by the BET method of 0.5 to 5 m. 2 / g of PTFE powder can be used. The fluororesin may be contained in an amount of 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the thermoplastic resin. Examples of fluororesins include PTFE, PFA, and FEP.

[0036] The resin composition may further contain carbon black as a colorant, polyolefin wax or stearyl alcohol as a mold release agent, and hydrotalcite or zinc carbonate as a mold corrosion inhibitor.

[0037] The resin composition of this embodiment contains, relative to 100 parts by mass of the entire resin composition, 59 parts by mass or more and 88 parts by mass or less of thermoplastic resin, 1 part by mass or more and 18 parts by mass or less of carbon fiber, and 0.3 parts by mass or more and 7 parts by mass or less of silane coupling agent, and by using isotropic pitch-based carbon fiber as the carbon fiber, it is possible to suppress melting deformation and fluidization, for example, even when coming into contact with a flame of about 1000°C.

[0038] (Method of producing resin composition) Next, an example of a method for producing the resin composition of this embodiment will be described. When producing the resin composition of this embodiment, first, the above-described thermoplastic resin is prepared, and then, when the total amount of the thermoplastic resin is taken as 100 parts by mass, an amount of the thermoplastic resin corresponding to a range of 4 parts by mass to 77 parts by mass is separated.

[0039] Next, the entire amount of the silane coupling agent constituting the resin composition is gradually added dropwise to the set-aside portion of the thermoplastic resin (silane coupling agent addition step), thereby obtaining a portion of the thermoplastic resin to which the silane coupling agent has been added.

[0040] Next, 23 parts by mass or more and 96 parts by mass or less of the remaining thermoplastic resin that has been set aside is added to the portion of the thermoplastic resin to which the silane coupling agent has been added, and dry blended to obtain an intermediate mixture in which the silane coupling agent and the entire amount of the thermoplastic resin are mixed (first mixing step).

[0041] Furthermore, materials other than the isotropic pitch-based carbon fiber constituting the resin composition are added to the intermediate mixture obtained in the first mixing step, and further dry blended. Then, using a twin-screw extruder, while again adding the entire amount of the isotropic pitch-based carbon fiber constituting the resin composition with a feeder, for example, the kneading temperature is controlled to 270°C or more and 300°C or less, the screw rotation speed is controlled to 100 rpm or more and 300 rpm or less, and the kneading time is controlled to 30 minutes or more and 60 minutes or less, thereby forming a pellet-shaped resin composition. (Second mixing process) .

[0042] The resin composition thus obtained can be molded by a known molding method such as extrusion molding using an extruder, press molding using a press, or injection molding using an injection molding machine to produce a resin molded article.

[0043] As described above, dry blending is important in the method for producing a resin composition. That is, by first separating a portion of the thermoplastic resin, dropping the silane coupling agent thereto, and then adding and blending the remaining thermoplastic resin in this order, the silane coupling agent can be uniformly dispersed in the thermoplastic resin, loss can be reduced, and the function of suppressing flow and deformation due to flames can be improved.

[0044] (Resin molded body) FIG. 1 is a perspective view of a lithium ion secondary battery cell to which a resin molded article according to one embodiment of the present invention is attached. This lithium ion secondary battery cell 1 is a rectangular battery cell, and a positive electrode terminal 3 and a negative electrode terminal 4 are provided on the top surface of an outer can 2, which is a battery container, with a safety valve 5 provided between them.

[0045] The safety valve 5 operates when the lithium-ion secondary battery cell 1 experiences thermal runaway and the internal pressure rises, and ejects high-temperature, high-pressure gas to prevent the outer can 2 from bursting.

[0046] If thermal runaway occurs in the lithium-ion secondary battery cell 1, there is a risk of it catching fire due to overheating, and if the high-temperature, high-pressure gas ejected from the safety valve 5 spreads over a wide area at once, it will be difficult to prevent the fire from spreading and causing damage.

[0047] Therefore, in this embodiment, as shown in Figures 2, 3, and Figure 4, which is a cross-sectional view taken along line AA in Figure 3, a flexible sheet-like resin molded body 6 is attached to the outer periphery of the lithium-ion secondary battery cell 1 via an insulating sheet 7 so as to cover at least the safety valve 5. Note that if the resin molded body 6 is made of an insulating material or if insulation is not required, the insulating sheet 7 need not be used.

[0048] In this embodiment, the insulating sheet 7 and the sheet-shaped resin molding 6 are both rectangular and of approximately the same size, and are attached so as to cover the top surface of the rectangular parallelepiped lithium ion secondary battery cell 1, including the safety valve 5, and also to cover the upper parts of the front and back surfaces (the left and right surfaces in Figure 4).

[0049] Lead wires (not shown) connected to the positive electrode terminal 3 and the negative electrode terminal 4 of the lithium ion secondary battery cell 1 are drawn out using the side surfaces not covered by the insulating sheet 7 and the resin molded body 6 .

[0050] The lithium-ion secondary battery cell 1 with the insulating sheet 7 and the sheet-like resin molded body 6 attached thereto is housed in an exterior case (not shown). Inside the exterior case, the resin molded body 6, which covers the upper front and rear surfaces of the lithium-ion secondary battery cell 1, is held in place by being pressed by the inner wall surface of the exterior case.

[0051] Furthermore, the thickness of the part of the resin molded body 6 that covers the safety valve 5, in this embodiment, the resin molded body 6 is in the form of a sheet of uniform thickness, and the thickness of this sheet-like resin molded body 6 may be 0.5 mm or more and 10.0 mm or less, preferably 0.7 mm or more and 5 mm or less, and more preferably 1.0 mm or more and 2 mm or less.

[0052] If this thickness is less than 0.5 mm, there is a concern that the high-temperature, high-pressure gas ejected from the safety valve 5 will create through-holes in the resin molding 6, and that the high-temperature, high-pressure gas will eject from the through-holes, causing fire and burn damage to components outside the lithium-ion secondary battery cells 1 covered by the insulating sheet 7 and the sheet-like resin molding 6. There is also a concern that the through-holes will act as a supply port for air (oxygen), which may cause fire to spread and burn damage to the lithium-ion secondary battery cells 1 themselves covered by the insulating sheet 7 and the sheet-like resin molding 6.

[0053] If the thickness of the sheet-shaped resin molding 6 exceeds 10.0 mm, high-temperature and high-pressure gas can be blocked, i.e., no through holes are formed, but the resin molding 6 becomes large and the molding process becomes complicated. Also, it becomes difficult to accommodate the resin molding 6 in an existing exterior case that accommodates lithium-ion secondary battery cells 1.

[0054] The surface hardness of the resin molded body 6 is preferably 50 or more as measured with a type D durometer using a 2 mm thick sheet of resin molded body in accordance with JIS K7215. If this surface hardness is less than 50, there is a concern that the high-temperature, high-pressure gas ejected from the safety valve 5 (particularly due to the influence of the pressure (ejection force)) may damage the resin molded body 6 or cause a through hole. The upper limit of this surface hardness is 90 as the appropriate upper limit in the above standard, but it may exceed 90 as long as it is within the moldable range. Note that a general measuring device can measure up to about 100, and the surface hardness of the resin molded body 6 displayed on the measuring device may be 100 or less.

[0055] As described above, the resin molded body 6 of this embodiment is formed using the above-mentioned resin composition so as to cover the safety valve 5 of the lithium-ion secondary battery cell 1. Therefore, even if the lithium-ion secondary battery experiences thermal runaway, the high-temperature, high-pressure gas ejected from the safety valve 5 will not cause a through hole to be formed in the resin molded body 6, and the spread of fire and burn damage caused by the ejection of high-temperature, high-pressure gas can be suppressed. [Example]

[0056] (Deformation resistance evaluation) Hereinafter, for evaluation of deformation resistance (fire resistance), samples (resin compositions) of Invention Example 1 and Comparative Examples 1 to 3, which were made by varying the types of carbon fibers contained in the resin compositions, were prepared. The composition ratios common to the samples of Inventive Example 1 and Comparative Examples 1 to 3 are as follows: Thermoplastic resin (polyphenylene sulfide resin (PPS)): 70.4% by mass Silane coupling agent (3-aminopropyltriethoxysilane): 0.70% by mass Carbon fiber: (see next section) 7.00% by mass Glass fiber: 20.00% by mass Release agent: (PE520: Clariant Chemicals, polyethylene wax) 0.40% by mass Corrosion inhibitor: (zinc carbonate (ZnCO3)) 0.70% by mass Colorant: (BP880: carbon black manufactured by Cabot Japan Co., Ltd.) 0.80% by mass The total of the above is 100% by mass

[0057] [Invention Example 1] As the carbon fiber, OGC360 (DonaCarbo: manufactured by Osaka Gas Chemicals Co., Ltd.), an isotropic pitch-based carbon fiber, was used, with an average fiber length of 360 μm and an average fiber diameter of 11 μm. [Comparative Example 1] As the carbon fiber, MCC6000 (Dialead: manufactured by Mitsubishi Chemical Corporation), an anisotropic pitch-based carbon fiber, with an average fiber length of 6000 μm and an average fiber diameter of 11 μm, was used. [Comparative Example 2] As the carbon fiber, MCC200 (Dialead: manufactured by Mitsubishi Chemical Corporation), an anisotropic pitch-based carbon fiber, with an average fiber length of 179 μm and an average fiber diameter of 11 μm, was used. [Comparative Example 3] As the carbon fiber, MCC50 (Dialead: manufactured by Mitsubishi Chemical Corporation), an anisotropic pitch-based carbon fiber, with an average fiber length of 58 μm and an average fiber diameter of 11 μm, was used.

[0058] The deformation resistance test was carried out for each of the resin compositions of Invention Example 1 and Comparative Examples 1 to 3 by fixing a 5580W burner facing vertically downward, preparing a resin composition (each sample) measuring 100mm x 120mm x 2mm, and placing each sample horizontally on the floor at a position 170mm from the burner nozzle.The burner was then ignited and the flame was applied to each sample.

[0059] Distance between sample and burner nozzle: 170 mm Local exhaust by draft Heating power: 5580W Temperature: 20℃ Humidity: 75%RH Weather: Sunny The test was terminated when part of the sample melted and fell to the floor. These test methods were performed twice for each sample. Table 1 shows the time (seconds) required for each sample to deform 10 mm.

[0060] [Table 1]

[0061] The evaluation of deformation resistance shown in Figure 5 and Table 1 confirmed that the use of isotropic pitch-based carbon fibers as the carbon fibers contained in the resin composition significantly delayed thermal deformation compared to the conventional example in which anisotropic pitch-based carbon fibers were used. Therefore, according to this embodiment, a resin composition can be realized that can suppress melting, deformation, and fluidization due to the injection of high-temperature gas or flame.

[0062] In the above-described evaluation of deformation resistance, each sample contained a mold corrosion inhibitor, a mold release agent, and a colorant, but these corrosion inhibitors, mold release agents, and colorants are not essential components of the resin composition constituting the resin molded article of the present invention. Even without these corrosion inhibitors, mold release agents, and colorants, a resin molded article having excellent deformation resistance can be obtained.

[0063] Furthermore, the contents of the corrosion inhibitor, release agent, and colorant in the above-described deformation resistance evaluation are merely examples, and the contents of the corrosion inhibitor, release agent, and colorant can be increased or decreased to any amount as needed, and are not limited to any particular amount. [Explanation of symbols]

[0064] 1...Lithium-ion secondary battery cell 2...Outer can 3...Positive terminal 4...Negative terminal 5...Safety valve 6...Resin molded body 7...Insulation sheet

Claims

1. A resin molded product made from a resin composition containing, relative to 100 parts by mass of the entire resin composition, 59 parts by mass or more and 88 parts by mass or less of polyphenylene sulfide as a thermoplastic resin, 1 part by mass or more and 18 parts by mass or less of carbon fiber, 0.3 parts by mass or more and 7 parts by mass or less of a silane coupling agent, and 3 parts by mass or more and 35 parts by mass or less of glass fiber, wherein the carbon fiber is an isotropic pitch-based carbon fiber, A resin molded article characterized by being attached to the outer periphery of one or more lithium ion secondary battery cells having a safety valve or a vent hole so as to cover at least the safety valve or the vent hole.

2. 2. The resin molded article according to claim 1, wherein the silane coupling agent is at least one of an organosilicon compound and a siloxane compound.

3. 3. The resin molded article according to claim 2, wherein the organosilicon compound is at least one of an amine-based silane coupling agent and an epoxy-based silane coupling agent.

4. A method for producing the resin molded article according to any one of claims 1 to 3, a silane coupling agent addition step in which the entire amount of the silane coupling agent is dropped onto a portion of the thermoplastic resin separated from 100 parts by mass of the thermoplastic resin in a range of 4 parts by mass to 77 parts by mass, thereby obtaining a portion of the thermoplastic resin to which the silane coupling agent has been added; a first mixing step of adding 23 parts by mass or more and 96 parts by mass or less of the remaining thermoplastic resin to the part of the thermoplastic resin to which the silane coupling agent has been added and mixing them to obtain an intermediate mixture in which the silane coupling agent and the entire amount of the thermoplastic resin are mixed; a second mixing step of adding all of the carbon fibers and all of the glass fibers to the intermediate mixture and further mixing them to obtain the resin composition; a step of molding the resin composition to obtain the resin molded body; A method for producing a resin molded article, comprising:

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