JP2024060540A - Integrated molded body and battery pack using the same - Google Patents

Abstract

To provide an integrally molded body having a high flame-proofing property and strength.SOLUTION: There is provided an integrally molded body made of multiple parts, comprising: a fiber-reinforced resin member (1) in which an inorganic fiber material (X) and a resin composition (A) are integrated; and a fiber-reinforced resin member (2) in which an inorganic fiber material (Y) and a resin composition (B) are integrated. An elongation of the inorganic fiber material (Y) at a maximum load is smaller than an elongation of the inorganic fiber material (X) at a maximum load. At least one of the resin composition (A) and the resin composition (B) contains a thermally expandable flame retardant.SELECTED DRAWING: None

Description

The present invention relates to an integrally molded body and a battery pack using the same.

In recent years, research and development of electric and hybrid vehicles has been promoted as part of environmental measures, and the development of high-energy density batteries and weight reduction are being actively promoted in order to improve the driving range. Such high-energy density batteries are at risk of catching fire in the event of an accident, so as a safety measure for passengers, the housing material must have high flame retardancy, and therefore, in many cases, metal materials such as iron are used in combination with fire-resistant materials.
However, metal materials have the drawback of being heavy, and when fire-resistant materials are used in combination, issues arise regarding workability and increased costs due to the increased number of parts. Therefore, attempts are being made to use resins, which have the potential to achieve both weight reduction and flame resistance. Currently, in order to create a sustainable society, emphasis is being placed on reducing carbon dioxide emissions and recyclability. Many thermosetting materials have high flame retardancy and are common as composite materials, but in terms of recyclability, thermoplastic resin materials are advantageous.

In a battery, for example, an internal short circuit may cause the electrolyte to decompose and vaporize, generating gas, which may lead to an abnormal rise in internal pressure. In such a case, the exhaust valve installed in the battery may open, and the vaporized electrolyte or the battery's internal components that have become hot may be ejected with force in a short period of time accompanied by flames, which may cause a so-called thermal runaway. The ejected material is a high-temperature, high-velocity powder-mixed fluid accompanied by flames, which may cause a major thermal problem that may spread to the battery, connected devices, and surrounding areas.
Additionally, China has announced a safety standard called GB 38031-2020 "Safety Requirements for Electric Vehicle Power Batteries," which requires a warning to be issued five minutes before the battery experiences thermal runaway. However, it is believed that this can be achieved by using housing materials that provide flame protection for more than five minutes after the battery ignites.

To address these issues, for example, Patent Document 1 proposes adding a brominated flame retardant or an antimony oxide compound to a carbon fiber reinforced polypropylene resin, but the additives used therein have a problem in terms of their persistence in living organisms.
In response to this, Patent Document 2 proposes a flame-retardant polyolefin-based composition in which a polyolefin-based resin contains a (poly)phosphate compound, as a technology for making polypropylene-based resin flame-retardant while taking into consideration bioretention.
Moreover, Patent Document 3 proposes a flame-retardant resin composition comprising a polypropylene resin, long glass fibers, and a phosphate compound.

JP 2014-62189 A JP 2013-119575 A JP 2011-88970 A

As mentioned above, conventional technology has many shortcomings in resinification, which has the potential to achieve both lightweight and flame-resistant properties in high-energy density batteries. Specifically, there is a demand for molded bodies that combine higher flame resistance and strength.

The present invention has been made to solve the above problems, and aims to provide an integrally molded body with high flame-resistant properties and strength. Another aim of the present invention is to provide a battery pack with superior flame-resistant properties and strength that can delay the spread of fire to automobile interior components when thermal runaway of the battery occurs and a flame breaks out.

In order to solve the above-mentioned problems, the present inventors discovered that an integrally molded body comprising at least a fiber-reinforced resin member formed by integrating a specific inorganic fiber material with a resin composition and a fiber-reinforced resin member formed by integrating a specific inorganic fiber material with a resin composition and containing a thermally expandable flame retardant can solve the above-mentioned problems, and based on these findings, they have completed the present invention.
That is, the present invention provides the following [1] to [15].
[1] An integrally molded body consisting of a plurality of members, comprising at least a fiber-reinforced resin member (1) in which an inorganic fiber material (X) and a resin composition (A) are integrated, and a fiber-reinforced resin member (2) in which an inorganic fiber material (Y) and a resin composition (B) are integrated, wherein the elongation of the inorganic fiber material (Y) at maximum load is smaller than the elongation of the inorganic fiber material (X) at maximum load, and at least one of the resin compositions (A) and (B) contains a thermally expandable flame retardant.
[2] The integrally molded body according to the above [1], wherein the inorganic fiber material (Y) has an elongation of 5% or less at maximum load.
[3] The integrally molded body according to the above [1] or [2], wherein the inorganic fiber material (X) has an elongation of more than 5% at maximum load.
[4] The integrally molded body according to any one of the above [1] to [3], wherein the inorganic fiber material (X) is an inorganic fiber nonwoven fabric.
[5] The integrally molded body according to any one of the above [1] to [4], wherein the inorganic fiber material (Y) is an inorganic fiber woven fabric.
[6] The integrally molded body according to any one of the above [1] to [5], wherein the resin constituting the resin compositions (A) and (B) includes a thermoplastic resin.
[7] The integrally molded body according to any one of the above [1] to [6], wherein the thermally expandable flame retardant is a phosphorus-based flame retardant.
[8] The integrally molded body according to any one of the above [1] to [7], wherein the resin composition (A) and/or (B) containing the thermally expandable flame retardant further contains a dispersant.
[9] The integrally molded body according to the above [8], wherein the dispersant is a copolymer of an α-olefin and an unsaturated carboxylic acid.
[10] The integrally molded body according to the above [8] or [9], wherein the content of the dispersant per 100 parts by mass of the thermally expandable flame retardant is more than 0 and not more than 25 parts by mass.
[11] The integrally molded body according to any one of the above [4] to [10], wherein the inorganic fibers constituting the inorganic fiber nonwoven fabric are at least one selected from glass fibers, ceramic fibers, metal fibers, and metal oxide fibers.
[12] The integrally molded body according to any one of the above [5] to [11], wherein the inorganic fibers constituting the inorganic fiber fabric are at least one selected from glass fibers, ceramic fibers, metal fibers, and metal oxide fibers.
[13] The integrally molded body according to any one of [6] to [12] above, wherein the thermoplastic resin is a polypropylene-based resin and the content of the polypropylene-based resin is 15 to 80 mass% based on the total weight.
[14] The integrally molded body according to any one of [1] to [13] above, wherein the content of the thermally expandable flame retardant is 1 to 30 mass% based on the total weight.
[15] A battery pack comprising: a plurality of battery cells each having a discharge valve that opens when the internal pressure exceeds a set pressure; and a battery housing incorporating the battery cells, wherein the battery housing is made of the integrally molded body described in any one of [1] to [14] above, and the fiber reinforced resin member (2) is partially disposed in a position facing the discharge outlet of the discharge valve of the battery cell.

The present invention can provide an integrally molded body with high flame-resistance and strength. It can also provide a battery pack with superior flame-resistance and strength that can delay the spread of fire to automobile interior components when thermal runaway occurs in the battery and a flame breaks out.

1 is a schematic diagram showing one embodiment of an integrally molded body of the present invention. FIG. 4 is a schematic view showing another embodiment of the integrally molded body of the present invention. FIG. 1 is a conceptual diagram illustrating a battery pack according to the present invention.

The following describes in detail the embodiments of the present invention, but the following description is merely an example of an embodiment of the present invention, and the present invention is not limited to these contents in any way.

[Integral molding]
The integrally molded product of the present invention is composed of a plurality of members, and includes at least a fiber-reinforced resin member (1) in which an inorganic fiber material (X) and a resin composition (A) are integrated, and a fiber-reinforced resin member (2) in which an inorganic fiber material (Y) and a resin composition (B) are integrated. It is essential that the elongation of the inorganic fiber material (Y) at maximum load is smaller than the elongation of the inorganic fiber material (X) at maximum load, and that at least one of the resin compositions (A) and (B) contains a thermally expandable flame retardant.
A specific layer structure may be a laminated embodiment in which a fiber-reinforced resin member (1) (11 in FIG. 1) in which an inorganic fiber material (X) such as an inorganic fiber nonwoven fabric is integrated with a resin composition (A) and a fiber-reinforced resin member (2) (12 in FIG. 1) in which an inorganic fiber material (Y) such as an inorganic fiber woven fabric is integrated with a resin composition (B) are laminated as shown in FIG. 2. In addition, the fiber-reinforced resin member (2) may be partially disposed.

In the present invention, it is preferable that the fiber reinforced resin member (2) is partially disposed as shown in Fig. 2. By partially disposing the fiber reinforced resin member (2), the content of the fiber reinforced resin member (1) in the integrally molded body is increased, and the moldability of the integrally molded body is improved. On the other hand, in a battery pack described later in detail, the fiber reinforced resin member (2) is disposed in a manner facing the exhaust valve of the battery cell, so that the function of the fiber reinforced resin member (2), i.e., the function of flameproofing and strength, can be fully exhibited.
The ratio of the area of the fiber reinforced resin member (2) to the fiber reinforced resin member (1) in the integrally molded body of the present invention can be appropriately set according to the requirements according to the application of the integrally molded body, and may be, for example, 5% or more, 10% or more, or 30% or more. It may also be 100% or less, 80% or less, or 50% or less. If it is equal to or more than the lower limit, the influence of the ejection accompanied by a flame ejected from the exhaust valve can be effectively suppressed, while if it is equal to or less than the upper limit, the molding processability of the integrally molded body can be improved.

<Resin composition (A) and resin composition (B)>
The resin compositions (A) and (B) constituting the integrally molded article of the present invention are not particularly limited, but are preferably thermoplastic resins in terms of achieving the effects of the present invention.
The thermoplastic resin is not particularly limited, and examples thereof include polyolefin resin, polycarbonate resin, polyester resin, acrylonitrile styrene resin, ABS resin, polyamide resin, modified polyphenylene oxide, etc. Among these, polyolefin resin is preferred in the present invention. These may be used alone or in combination of two or more. For example, the (a) thermoplastic resin may be a composite resin of two or more of the above thermoplastic resins.
The resins constituting the resin compositions (A) and (B) may be the same or different, but it is preferable to use the same resin from the viewpoint of ease of production. Therefore, it is preferable that both of the resins constituting the resin compositions (A) and (B) are polyolefin resins.

The polyolefin resin is not particularly limited, and examples thereof include the resins described below. The polyester resin is not particularly limited, and examples thereof include polybutylene terephthalate. The polyamide resin is not particularly limited, and examples thereof include nylon 66 and nylon 6.
Among them, the present invention is particularly useful when the thermoplastic resin (a) contains at least a polyolefin resin. In the present invention, the term "polyolefin resin" refers to a resin in which the proportion of olefin units or cycloolefin units is 90 mol % or more relative to 100 mol % of all structural units constituting the resin.
The proportion of olefin units or cycloolefin units relative to 100 mol % of all structural units constituting the polyolefin resin is preferably 95 mol % or more, and particularly preferably 98 mol % or more.

Examples of polyolefin resins include α-olefin polymers such as polyethylene, polypropylene, polybutene, poly(3-methyl-1-butene), poly(3-methyl-1-pentene), and poly(4-methyl-1-pentene); α-olefin copolymers such as ethylene-propylene block or random copolymers, α-olefin-propylene block or random copolymers having 4 or more carbon atoms, ethylene-methyl methacrylate copolymers, and ethylene-vinyl acetate copolymers; and cycloolefin polymers such as polycyclohexene and polycyclopentene. Examples of polyethylene include low-density polyethylene, linear low-density polyethylene, and high-density polyethylene. Examples of polypropylene include isotactic polypropylene, syndiotactic polypropylene, hemiisotactic polypropylene, and stereoblock polypropylene. In the α-olefin-propylene block or random copolymers having 4 or more carbon atoms, examples of the α-olefins having 4 or more carbon atoms include butene, 3-methyl-1-butene, 3-methyl-1-pentene, and 4-methyl-1-pentene. These polyolefin resins may be used alone or in combination of two or more.
Of the above olefin resins, polypropylene resin (hereinafter sometimes referred to as "PP resin") is particularly preferred.

(Melt Flow Rate (MFR))
The melt flow rate (hereinafter sometimes abbreviated as MFR) (230°C, 2.16 kg load) of the thermoplastic resin (a) used in the present invention is preferably 40 to 500 g/10 min. If the MFR is 40 g/10 min or more, for example, no chipping occurs when obtaining a molded body by stamping molding, and the processability does not decrease. Also, if it is 500 g/10 min or less, no burrs are generated in the production of an integrally molded body. From the above viewpoints, the MFR is preferably 50 to 400 g/10 min, more preferably 60 to 400 g/10 min, and more preferably 70 to 300 g/10 min.
The MFR of the (a) thermoplastic resin can be adjusted, for example, by controlling the hydrogen concentration during polymerization.
The MFR is a value measured in accordance with JIS K7210.

((a) Thermoplastic Resin Content)
Hereinafter, examples of suitable thermoplastic resin compositions will be described as examples of the resin compositions in the present invention. Resin composition (A) may be described as thermoplastic resin composition (A), and resin composition (B) may be described as thermoplastic resin composition (B).
The content of the thermoplastic resin (a) in the integrally molded body of the present invention is not particularly limited, but it is preferably contained in the thermoplastic resin compositions (A) and (B) in an amount of 15 to 80 mass% each. When the content of the thermoplastic resin (a) is 15 mass% or more, the molding processability is particularly good, and the molding of the integrally molded body is easy. On the other hand, when the content of the thermoplastic resin (a) is 80 mass% or less, a sufficient amount of flame retardant, dispersant, and inorganic fiber can be contained, and good flame insulation can be obtained. From the above viewpoints, the content of the thermoplastic resin (a) in the thermoplastic resin compositions (A) and (B) is preferably 35 to 70 mass%, more preferably 40 to 60 mass%.

<(a-1) Polypropylene Resin>
The thermoplastic resin (a) used in the integrally molded article of the present invention preferably contains a polypropylene-based resin. Examples of the polypropylene-based resin include a propylene homopolymer and a propylene-α-olefin copolymer. Here, the propylene-α-olefin copolymer may be either a random copolymer or a block copolymer.

(α-Olefin)
Examples of the α-olefin constituting the copolymer include ethylene, 1-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, and 1-octene. One of these may be copolymerized with propylene, or two or more may be copolymerized with propylene. Among them, from the viewpoint of improving the impact strength of the integrally molded body, ethylene or 1-butene, which have a large effect, are preferred, and ethylene is the most preferred.

(Propylene-ethylene random copolymer)
In the case of a random copolymer of propylene and ethylene, it preferably contains 90 to 99.5% by mass, more preferably 92 to 99% by mass, of propylene units and preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass of ethylene units. When the ethylene units are equal to or more than the lower limit, sufficient impact strength of the integrally molded body is obtained, and when the ethylene units are equal to or less than the upper limit, sufficient rigidity is maintained.
The contents of propylene units and ethylene units in the random copolymer of propylene and ethylene can be adjusted by controlling the composition ratio of propylene and ethylene during polymerization of the random copolymer of propylene and ethylene.
The propylene content of the random copolymer of propylene and ethylene is a value measured using a cross fractionation device, FT-IR, or the like, and the measurement conditions and the like may be, for example, those described in JP-A-2008-189893.

(Melt Flow Rate (MFR))
The MFR (230°C, 2.16 kg load) of the polypropylene resin (a-1) used in the present invention is preferably 40 to 500 g/10 min. If the MFR is 40 g/10 min or more, no chipping occurs when obtaining an integrally molded body by stamping molding or the like, and the processability does not decrease. If the MFR is 500 g/10 min or less, no burrs are generated in the production of a sheet used to prepare an integrally molded body. From the above viewpoints, the MFR is preferably 50 to 400 g/10 min, more preferably 60 to 400 g/10 min, and more preferably 70 to 300 g/10 min.
The MFR of the (a-1) polypropylene resin (propylene homopolymer) can be adjusted by controlling the hydrogen concentration during polymerization.
The MFR is a value measured in accordance with JIS K7210.

((a-1) Content of polypropylene resin)
The content of the polypropylene resin (a-1) in the integrally molded body of the present invention is not particularly limited, but is preferably 15 to 80% by mass. If the content of the polypropylene resin is 15% by mass or more, the molding processability is sufficient, and the molding of the integrally molded body is easy. On the other hand, if it is 80% by mass or less, the content of the flame retardant, dispersant, and inorganic fiber is sufficient, and sufficient flame insulation is obtained. From the above viewpoints, the content of the polypropylene resin in the integrally molded body is more preferably 35 to 70% by mass, and even more preferably 40 to 60% by mass.

<Modified polyolefin resin>
The integrally molded article of the present invention can further contain a modified polyolefin resin in addition to the polypropylene resin. Specific examples of the modified polyolefin resin include acid-modified polyolefin resins and hydroxy-modified polyolefin resins, and these can be used alone or in combination.
The types of acid-modified polyolefin resins and hydroxy-modified polyolefin resins used as the modified polyolefin resins are not particularly limited, and may be any of the conventionally known resins.

(Acid-modified polyolefin resin)
Examples of acid-modified polyolefin resins include those obtained by graft copolymerizing polyolefins such as polyethylene, polypropylene, ethylene-α-olefin copolymers, ethylene-α-olefin-non-conjugated diene compound copolymers (such as EPDM), and ethylene-aromatic monovinyl compound-conjugated diene compound copolymer elastomers with unsaturated carboxylic acids such as maleic acid or maleic anhydride, thereby chemically modifying the polyolefins.
The graft copolymerization is carried out, for example, by reacting the polyolefin with an unsaturated carboxylic acid in a suitable solvent using a radical generator such as benzoyl peroxide. The unsaturated carboxylic acid or its derivative component can also be introduced into the polymer chain by random or block copolymerization with a polyolefin monomer.

Examples of unsaturated carboxylic acids used for modification include compounds having a carboxyl group, such as maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid, and a polymerizable double bond into which a functional group, such as a hydroxyl group or an amino group, has been introduced as necessary.
Derivatives of unsaturated carboxylic acids include their acid anhydrides, esters, amides, imides, metal salts, etc., and specific examples thereof include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, etc. Of these, maleic anhydride is preferred.

Preferred acid-modified polyolefin resins include those modified by graft polymerization of maleic anhydride to an olefin polymer having ethylene and/or propylene as the main polymer unit, and those modified by copolymerization of an olefin mainly consisting of ethylene and/or propylene with maleic anhydride. Specific examples include a combination of polyethylene/maleic anhydride grafted ethylene-butene-1 copolymer, or a combination of polypropylene/maleic anhydride grafted polypropylene.

(Hydroxy-modified polyolefin resin)
The hydroxy-modified polyolefin resin is a modified polyolefin resin containing a hydroxyl group. The hydroxy-modified polyolefin resin may have a hydroxyl group at an appropriate site, for example, at the end of the main chain or on a side chain.
Examples of the olefin resin constituting the hydroxy-modified polyolefin resin include homopolymers or copolymers of α-olefins such as ethylene, propylene, butene, 4-methylpentene-1, hexene, octene, nonene, decene, and dodecene, and copolymers of the above-mentioned α-olefins with copolymerizable monomers.
Examples of preferred hydroxy-modified polyolefin resins include hydroxy-modified polyethylene resins such as low-, medium- or high-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene, ethylene-(meth)acrylic acid ester copolymers, and ethylene-vinyl acetate copolymers; and hydroxy-modified polypropylene resins such as polypropylene homopolymers such as isotactic polypropylene, random copolymers of propylene and α-olefins (e.g., ethylene, butene, hexane, etc.), propylene-α-olefin block copolymers, and hydroxy-modified poly(4-methylpentene-1).

<(b) Thermally Expandable Flame Retardant>
At least one of the resin compositions (A) and (B) constituting the integrally molded body of the present invention contains a thermally expandable flame retardant. That is, the thermally expandable flame retardant may be contained only in the resin composition (A), or may be contained only in the resin composition (B). Also, the thermally expandable flame retardant may be contained in both the resin composition (A) and the resin composition (B). In the integrally molded body of the present invention, it is preferable that the resin composition (B) contains a thermally expandable flame retardant, and it is more preferable that both the resin composition (A) and the resin composition (B) contain a thermally expandable flame retardant.
(b) A thermally expandable flame retardant is a flame retardant that suppresses the combustion of a material by forming an intumescent surface layer that prevents the diffusion of radiant heat from the combustion source and combustion gases and smoke from the burning material to the outside.

Among the thermally expandable flame retardants, phosphorus-based flame retardants are preferred, and examples thereof include salts of (poly)phosphoric acid and nitrogen compounds (hereinafter also referred to as "compound (b1)"). Specific examples thereof include ammonium salts and amine salts of (poly)phosphoric acid, such as ammonium polyphosphate, melamine polyphosphate, piperazine polyphosphate, ammonium pyrophosphate, melamine pyrophosphate, and piperazine pyrophosphate.
Examples of the nitrogen compounds include ammonia, melamine, piperazine, and other nitrogen compounds. Examples of the other nitrogen compounds include, for example, N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-diethylethylenediamine, amine, 1,2-propanediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, trans-2,5-dimethylpiperazine, 1,4-bis(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, acetoguanamine, benzoguanamine, acrylguanamine, 2 ,4-diamino-6-nonyl-1,3,5-triazine, 2,4-diamino-6-hydroxy-1,3,5-triazine, 2-amino-4,6-dihydroxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino 1,3-hexylene dimelamine, ...

<Other flame retardants>
As described above, the integrally molded body of the present invention is characterized by including a thermally expandable flame retardant, but other flame retardants may be used in addition to the thermally expandable flame retardant. The other flame retardants are not particularly limited, and conventionally used flame retardants can be used.
Specifically, for example, phosphorus-based flame retardants other than the above-mentioned thermally expandable flame retardants, bromine-based flame retardants, antimony-based flame retardants, etc. Among them, phosphorus-based flame retardants are preferred from the viewpoint of improving flame-shielding properties.

(Phosphorus-based flame retardant)
The phosphorus-based flame retardant is a phosphorus compound, i.e., a compound containing a phosphorus atom in the molecule, and exerts a flame retardant effect by forming char when the resin composition is burned.
The phosphorus-based flame retardant may be a known one, and examples thereof include (poly)phosphates, (poly)phosphate esters, etc. Here, "(poly)phosphates" refers to phosphates or polyphosphates, and "(poly)phosphate esters" refers to phosphate esters or polyphosphate esters.
The phosphorus-based flame retardant is preferably solid at 80°C.

As the phosphorus-based flame retardant, (poly)phosphates are preferred in terms of flame retardancy.
Examples of (poly)phosphates include ammonium polyphosphate, melamine polyphosphate, piperazine polyphosphate, piperazine orthophosphate, melamine pyrophosphate, piperazine pyrophosphate, melamine polyphosphate, melamine orthophosphate, calcium phosphate, and magnesium phosphate.
In the above examples, compounds in which melamine or piperazine is replaced with other nitrogen compounds can also be used. These (poly)phosphates may be used alone or in combination of two or more.

Commercially available phosphorus-based flame retardants include Adeka STAB FP-2100J, FP-2200, and FP-2500S (manufactured by ADEKA Corporation).

(Brominated flame retardants)
Examples of bromine-based flame retardants include decabromodiphenyl ether, tetrabromobisphenol A, tetrabromobisphenol S, 1,2-bis(2',3',4',5',6'-pentabromophenyl)ethane, 1,2-bis(2,4,6-tribromophenoxy)ethane, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, 2,6-dibromophenol, 2,4-dibromophenol, Examples of the polybrominated polystyrene include brominated polystyrene, ethylene bistetrabromophthalimide, hexabromocyclododecane, hexabromobenzene, pentabromobenzyl acrylate, 2,2-bis[4'(2'',3''-dibromopropoxy)-3',5'-dibromophenyl]-propane, bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]sulfone, and tris(2,3-dibromopropyl)isocyanurate.

(Antimony-based flame retardant)
Examples of antimony-based flame retardants include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium pyroantimonate, antimony trichloride, antimony trisulfide, antimony oxychloride, antimony perchloropentane dichloride, and potassium antimonate, with antimony trioxide and antimony pentoxide being particularly preferred.

Among the above flame retardants, phosphorus-based flame retardants are preferred because they are non-bioresistent and have excellent flame retardancy, and non-halogen flame retardants are preferred from the environmental standpoint.
The flame retardants may be used alone or in combination of two or more.

((b) Content of thermally expandable flame retardant)
The content of the thermally expandable flame retardant in the integrally molded body of the present invention is not particularly limited, but is preferably in the range of 1 to 30 mass%. When the content is 1 mass% or more, good flame retardancy can be imparted to the integrally molded body, and good flame shielding properties can be obtained. On the other hand, when the content of the flame retardant is 30 mass% or less, the thermoplastic resin can be contained in a sufficient content ratio, so that the molding processability is improved. From the above viewpoints, the content of the thermally expandable flame retardant in the integrally molded body is more preferably in the range of 1 to 25 mass%, and even more preferably in the range of 3 to 20 mass%.
<(c) Dispersant>
Of the resin compositions (A) and (B) according to the present invention, the resin composition containing the thermally expandable flame retardant preferably further contains a dispersant.
The (c) dispersant is not particularly limited as long as it can disperse the (b) thermally expandable flame retardant in the (a) thermoplastic resin, but a polymer dispersant can be suitably used in terms of compatibility with the (a) thermoplastic resin. Preferably, a polymer dispersant capable of dispersing the (b) thermally expandable flame retardant in the (a-1) polypropylene resin can be used. As the polymer dispersant, a polymer dispersant having a functional group is preferred, and from the viewpoint of dispersion stability, a polymer dispersant having a functional group such as a carboxyl group, a phosphoric acid group, a sulfonic acid group, a primary, secondary or tertiary amino group, a quaternary ammonium base, a group derived from a nitrogen-containing heterocycle such as pyridine, pyrimidine or pyrazine is preferred.
In the present invention, a polymer dispersant having a carboxyl group is preferred, and in particular, when a phosphorus-based flame retardant suitable as a flame retardant is used, a copolymer of an α-olefin and an unsaturated carboxylic acid is preferred. By using such a dispersant, the dispersibility of the phosphorus-based thermally expandable flame retardant can be improved, and the content of the thermally expandable flame retardant can be reduced.

(Copolymer of α-olefin and unsaturated carboxylic acid)
In the "copolymer of α-olefin and unsaturated carboxylic acid" according to the present invention (hereinafter referred to as "copolymer (c1)"), the proportion of α-olefin units in the total of 100 mol % of α-olefin units and unsaturated carboxylic acid units is preferably 20 mol % or more and 80 mol % or less.
In the copolymer (c1), the ratio of the α-olefin units to the total amount of the α-olefin units and the unsaturated carboxylic acid units is more preferably 30 mol % or more, and more preferably 70 mol % or less. If the ratio of the α-olefins is equal to or more than the lower limit, the compatibility with the polyolefin resin is better, and if it is equal to or less than the upper limit, the compatibility with the (b) thermally expandable flame retardant is better.

In the copolymer (c1), the α-olefin is preferably an α-olefin having 5 or more carbon atoms, and more preferably an α-olefin having 10 to 80 carbon atoms. If the α-olefin has 5 or more carbon atoms, it tends to have better compatibility with the thermoplastic resin (a), and if it has 80 or less carbon atoms, it is advantageous in terms of raw material costs. From the above viewpoints, it is even more preferable that the α-olefin has 12 to 70 carbon atoms, and particularly preferably 18 to 60 carbon atoms.

In the copolymer (c1), examples of the unsaturated carboxylic acid include (meth)acrylic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, glutaconic acid, norbornane-5-ene-2,3-dicarboxylic acid, and esters, anhydrides, imides, etc. of these unsaturated carboxylic acids. Note that "(meth)acrylic acid" refers to acrylic acid or methacrylic acid.
Specific examples of the ester, anhydride or imide of an unsaturated carboxylic acid include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and glycidyl (meth)acrylate; dicarboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic acid anhydride; maleimide compounds such as maleimide, N-ethylmaleimide, and N-phenylmaleimide. These may be used alone or in combination of two or more.
Among the above, esters and dicarboxylic anhydrides are preferred from the viewpoint of copolymerization reactivity, and among these, dicarboxylic anhydrides are preferred, with maleic anhydride being particularly preferred, from the viewpoint of compatibility with thermally expandable phosphorus-based flame retardants suitable as flame retardants.

The weight average molecular weight of the copolymer (c1) is preferably 2,000 or more, more preferably 3,000 or more, and is preferably 50,000 or less, more preferably 30,000 or less. When the weight average molecular weight of the copolymer (c1) is within the above range, the dispersibility of the flame retardant (b) is more excellent.
The weight average molecular weight of the copolymer (c1) is a value calculated as standard polystyrene by dissolving the copolymer (c1) in tetrahydrofuran (THF) and measuring the result by gel permeation chromatography.

Commercially available copolymers (c1) include Ricorb CE2 (Clariant Japan Co., Ltd.) and Diacalna 30M (Mitsubishi Chemical Co., Ltd.).

The content of the dispersant (c) relative to 100 parts by mass of the thermally expandable flame retardant (b) in the integrally molded body of the present invention is in the range of more than 0 and not more than 25 parts by mass, and preferably in the range of 0.01 to 10 parts by mass.
According to the study by the inventors, the flame-proofing property of the integrally molded body can be significantly improved by uniformly dispersing the thermally expandable flame retardant in the inorganic fibers constituting the integrally molded body with the thermoplastic resin as the matrix resin. Although the detailed mechanism is unclear, the inventors speculate as follows. That is, when the thermally expandable flame retardant is uniformly dispersed in the resin between the inorganic fibers, the char formed by the thermally expandable flame retardant coming into contact with the flame is fixed in the gaps between the inorganic fibers. Furthermore, the size of the char formed by expansion upon contact with the flame is restricted by the gaps between the inorganic fibers, so that the size of the char formed becomes uniform. It is believed that the combination of the fixing effect of the char by the inorganic fibers and the uniformity of the char size results in the formation of a dense char, which significantly improves the flame-proofing property of the integrally molded body. Based on these findings, the inventors have found that by setting the ratio of the content of the dispersant to the thermally expandable flame retardant to a specific range, the thermally expandable flame retardant can be controlled to be uniformly present in the resin between the inorganic fibers, and the flame-proofing property of the integrally molded body can be significantly improved.
For the above reasons, when the content of the dispersant (c) is more than 0, the dispersibility of the flame retardant (b) is sufficient, and sufficient flame-shielding properties can be imparted to the integrally molded body. On the other hand, when the content is 25 parts by mass or less, the physical properties of the integrally molded body are sufficient. From the same viewpoint, the content of the dispersant (c) is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 1 part by mass or more, and particularly preferably 2 parts by mass or more. On the other hand, the upper limit value is more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less.

In addition, the ratio of the (c) dispersant to the total of 100 parts by mass of the (a) thermoplastic resin and the (b) thermally expandable flame retardant is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more. On the other hand, it is preferably 10 parts by mass or less, more preferably 5.0 parts by mass or less, even more preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1.0 parts by mass or less. If the ratio of the (c) dispersant is equal to or greater than the lower limit, the (b) thermally expandable flame retardant is better dispersed, and the flame retardant, physical properties, and appearance of the obtained integrally molded body are better. If the ratio of the (c) dispersant is equal to or less than the upper limit, the effect of the (c) dispersant on the flame retardant of the integrally molded body can be further suppressed. In particular, the ratio of the dispersant (c) to the total of 100 parts by mass of the polyolefin resin and the thermally expandable flame retardant (b) is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more. On the other hand, it is preferably 10 parts by mass or less, more preferably 5.0 parts by mass or less, even more preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1.0 parts by mass or less.

For inorganic fibers described in detail below, the ratio of the (c) dispersant to 100 parts by mass of the inorganic fibers is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more. On the other hand, it is preferably 10 parts by mass or less, more preferably 5.0 parts by mass or less, and even more preferably 2.0 parts by mass or less. If the ratio of the (c) dispersant is equal to or greater than the lower limit, the flame-resistant properties, physical properties, and appearance of the obtained integrally molded body will be improved. If the ratio of the (c) dispersant is equal to or less than the upper limit, the effect of the (c) dispersant on the flame-resistant properties of the integrally molded body can be further suppressed.

<Inorganic fiber material (X)>
The integrally molded body of the present invention comprises a fiber-reinforced resin member (1) in which an inorganic fiber material (X) and a resin composition (A) are integrated. The inorganic fiber material (X) used in the fiber-reinforced composite material of the present invention is an inorganic fiber organization in which a plurality of inorganic fibers are aggregated and a fixed or amorphous organization form is maintained. The inorganic fiber material (X) is characterized in that its elongation at maximum load is greater than that of the inorganic fiber material (Y). Since the fiber-reinforced resin member (1) contains the inorganic fiber material (X), the permeability of the resin composition is relatively high, and the fiber-reinforced resin member (1) exhibits high heat resistance. In addition, when the resin composition (A) contains a thermally expandable flame retardant, it also has high heat resistance and flame-shielding functions.
The elongation at maximum load of the inorganic fiber material (X) is not particularly limited as long as it is greater than that of the inorganic fiber material (Y), but is preferably greater than 5%. In this case, the impregnation of the resin composition is improved, and the heat resistance and flame shielding properties can be improved. From the same viewpoint, the elongation may be 7% or more, 9% or more, or 10% or more. The upper limit is usually 30%.
A specific example of an inorganic fiber material having the above-mentioned elongation is an inorganic fiber nonwoven fabric. Various fibers can be used as the fibers used in the inorganic fiber nonwoven fabric, and examples of the fibers include glass fiber, rock wool, alumina fiber, silica alumina fiber, and other metal oxide fibers, potassium titanate fiber, calcium silicate (wollastonite) fiber, ceramic fiber, such as ceramic fiber, carbon fiber, and metal fiber. These inorganic fibers may be used alone or in combination of two or more.
Of the above inorganic fibers, at least one selected from glass fibers and alumina fibers is preferred from the viewpoints of flame resistance and processability.
The inorganic fibers may contain two or more inorganic fibers having different melting temperatures. As a combination of two or more inorganic fibers having different melting temperatures, at least one of the fibers is preferably a glass fiber, and the other one or more fibers is preferably a combination of one or more inorganic fibers selected from the group consisting of alumina fiber, silica fiber, alkaline earth silicate fiber (biosoluble), and carbon fiber. By containing two or more inorganic fibers having different melting temperatures, it is possible to effectively prevent the deterioration of the flame-shielding function.
The inorganic fibers used in the present invention may be used in combination with a sizing agent or a surface treatment agent, such as compounds having a functional group, such as epoxy compounds, silane compounds, and titanate compounds.

The inorganic fibers preferably have an average fiber diameter of 3 to 25 μm, and an average fiber length of 0.1 mm or more, more preferably 1 mm or more, and even more preferably 5 mm or more.
As for the average fiber diameter and the average fiber length, the preferred ranges vary depending on the type of inorganic material constituting the inorganic fibers, and specific preferred ranges will be described later.
The fiber diameter can be measured using a scanning electron microscope or the like, and the average fiber diameter can be obtained by, for example, measuring the fiber diameters of 10 randomly selected fibers and calculating the average value. The fiber length can be measured using a ruler, calipers, or the like from an image enlarged by a microscope or the like as necessary, and the average fiber length can be obtained by, for example, measuring the fiber lengths of 10 randomly selected fibers and calculating the average value.

The total content of inorganic fibers in the integrally molded body of the present invention is preferably 1 to 80% by mass. When the total content of inorganic fibers is 1% by mass or more, the strength, rigidity, and impact resistance of the integrally molded body are good. When the total content of inorganic fibers is 80% by mass or less, the manufacture and processing of the integrally molded body are easy. When the total content of inorganic fibers is 80% by mass or less, the specific gravity of the integrally molded body is light, and the weight reduction effect as a metal substitute is remarkable.
From the above viewpoints, the total content of the inorganic fibers in the integrally molded body is more preferably 3 to 60 mass%, further preferably 10 to 50 mass%, and particularly preferably 30 to 45 mass%. The total content of the inorganic fibers in the integrally molded body is the sum of the contents of the inorganic fiber material (X) and the inorganic fiber material (Y) described below.
The content of the inorganic fiber material (X) in the integrally molded body of the present invention is preferably 1 to 50% by mass. When the total content of the inorganic fibers is 1% by mass or more, the strength, rigidity, and impact resistance of the integrally molded body are good. Furthermore, when the total content of the inorganic fibers is 50% by mass or less, the manufacture and processing of the integrally molded body are easy. From the above viewpoints, the total content of the inorganic fibers in the integrally molded body is more preferably 3 to 40% by mass, even more preferably 5 to 30% by mass, and particularly preferably 10 to 25% by mass.

(Glass fiber)
One of the inorganic fibers suitable for the integrally molded body of the present invention is glass fiber. The glass fiber may be, for example, a long fiber having an average fiber length of 30 mm or more, or a fiber having a short average fiber length (chopped strands). From the viewpoints of flame retardancy, rigidity, impact resistance, etc., it is preferable to use glass fiber having a long average fiber length.
More specifically, the average fiber length is preferably 5 mm or more. When the average fiber length is 5 mm or more, the strength and impact resistance of the integrally molded body are good. From the above viewpoints, the average fiber length of the glass fiber is preferably 5 mm or more, and more preferably 30 mm or more.
For example, when using pellets produced by the pultrusion method using glass fibers, the length of the pellets is the fiber length of the glass fibers, and is a maximum of about 20 mm. In a swirl mat system using long glass fibers, the length of the glass fibers in the roving used for production is the maximum fiber length, which can be as long as 17,000 m (17 km), but when cut to fit the size of the integrally molded body, the cut length is the maximum fiber length.

The average fiber diameter of the glass fibers is preferably in the range of 9 to 25 μm. When the average fiber diameter is 9 μm or more, the rigidity and impact resistance of the integrally molded body are sufficient, while when the average fiber diameter is 25 μm or less, the strength of the integrally molded body is good. From the above viewpoints, the average fiber diameter of the glass fibers is more preferably in the range of 10 to 15 μm.
The average fiber diameter and average fiber length of the glass fibers can be measured by the above-mentioned method.

There are no particular limitations on the material of the glass fiber used in the present invention, and it may be any of alkali-free glass, low-alkali glass, and alkali-containing glass, and any of the various compositions that have been used conventionally as glass fibers can be used.

(Alumina fiber)
One of the inorganic fibers suitable for the integrally molded body of the present invention is alumina fiber. Alumina fiber is usually a fiber made of alumina and silica, and in the integrally molded body of the present invention, the alumina/silica composition ratio (mass ratio) of the alumina fiber is preferably in the range of 65/35 to 98/2, which is called a mullite composition, or a high alumina composition, more preferably in the range of 70/30 to 95/5, and particularly preferably in the range of 70/30 to 74/26.

The average fiber diameter of the alumina fibers is preferably in the range of 3 to 25 μm, and it is preferable that the alumina fibers are substantially free of fibers with a fiber diameter of 3 μm or less. Here, "substantially free of fibers with a fiber diameter of 3 μm or less" means that the amount of fibers with a fiber diameter of 3 μm or less is 0.1 mass % or less of the total inorganic fiber mass.
The average fiber diameter of the alumina fibers is more preferably 5 to 8 μm. If the average fiber diameter of the inorganic fibers is too large, the repulsive force and toughness of the mat-like inorganic fiber assembly layer will decrease, while if the average fiber diameter is too small, the amount of dust suspended in the air will increase, and the probability of containing inorganic fibers having a fiber diameter of 3 μm or less will increase.
The alumina fibers have an average fiber length of preferably 5 mm or more, more preferably 30 mm or more, and even more preferably 50 mm or more. Also, the average fiber length and average fiber diameter of the alumina fibers are preferably 3.0×10 mm or less, and more preferably 1.0×10 mm or less. When the average fiber length and average fiber diameter of the alumina fibers are within these ranges, the strength and impact resistance of the integrally molded body are good.

(Carbon fiber)
The suitable range for carbon fiber is similar to that for glass fiber.

<Inorganic fiber material (Y)>
The integrally molded body of the present invention includes a fiber-reinforced resin member (2) in which an inorganic fiber material (Y) and a resin composition (B) are integrated. The inorganic fiber material (Y) used in the fiber-reinforced composite material of the present invention is an inorganic fiber structure in which a plurality of inorganic fibers are aggregated to maintain a fixed or amorphous structure. The inorganic fiber material (Y) is characterized in that its elongation at maximum load is smaller than that of the inorganic fiber material (X). This ensures flame-proofing and strength when the fiber-reinforced resin member (2) is formed together with the thermoplastic resin composition (B). This is thought to be because the inorganic fiber material (Y) is appropriately impregnated and integrated with the thermoplastic resin composition (X), thereby improving mechanical strength, and the phosphorus-based flame retardant contained in the thermoplastic resin composition (X) forms dense char in the gaps in the fiber structure of the inorganic fiber material (Y), thereby simultaneously exerting flame-proofing and strength against shock waves when exposed to flame. As a result, the fiber-reinforced resin member (2) in which the inorganic fiber material (Y) and the resin composition (B) are integrated has high strength even against high-temperature and high-velocity powder-mixed fluid in the event of thermal runaway, and serves to suppress damage to the integrally molded body of the present invention.

The elongation of the inorganic fiber material (Y) at maximum load is not particularly limited as long as it is smaller than that of the inorganic fiber material (X), but it is preferably 5% or less. In this case, the flame-proofing property and strength of the integrally molded body can be improved. From the same viewpoint, the elongation may be 4% or less, 3% or less, or 2% or less. On the other hand, from the viewpoint of improving moldability, it is preferably 0.1% or more.

A specific example of an inorganic fiber material having the above-mentioned elongation is an inorganic fiber woven fabric.
The inorganic fiber fabric is a fabric composed of warp and weft threads made of inorganic fibers. The weave is not particularly limited and may be any of plain weave, twill weave, satin weave, etc. It is preferable that the gaps between the warp fiber bundles constituting the fabric and the gaps between the weft bundles are each 0.5 mm or less. When the gaps are 0.5 mm or less, high flame blocking properties are obtained.
The inorganic fibers constituting the inorganic fiber woven fabric may be the same as those in the inorganic fiber nonwoven fabric, and the preferred ranges are also the same. The preferred ranges of the average fiber diameter and average fiber length of the inorganic fibers are also the same.
The fibers constituting the inorganic fiber woven fabric and the fibers constituting the inorganic nonwoven fabric may be the same or different.

The content of the inorganic fiber material (Y) in the integrally molded body of the present invention is preferably 1 to 80% by mass. When the content of the inorganic fiber fabric is 1% by mass or more, the strength, rigidity, and impact resistance of the fiber-reinforced resin member (2) are sufficient, and when it is 80% by mass or less, it is preferable in terms of manufacturing and processing the integrally molded body. In addition, when the content of the inorganic fiber fabric is 80% by mass or less, the specific gravity of the integrally molded body is lightened, and the weight reduction effect as a metal substitute is remarkable.
From the above viewpoints, the content of the inorganic fiber material (Y) in the integrally molded body of the present invention is more preferably 3 to 60 mass%, even more preferably 10 to 50 mass%, and particularly preferably 30 to 45 mass%.

<Optionally Added Ingredients>
In addition to the above-mentioned components, any additive components may be blended into the integrally molded body of the present invention for the purpose of further improving the effects of the present invention or imparting other effects, within a range that does not significantly impair the effects of the present invention.
Specific examples of the additives include colorants such as pigments, light stabilizers such as hindered amines, ultraviolet absorbers such as benzotriazoles, nucleating agents such as sorbitols, antioxidants such as phenols and phosphorus, antistatic agents such as nonionic surfactants, neutralizing agents such as inorganic compounds, antibacterial and antifungal agents such as thiazoles, flame retardants and flame retardant assistants such as halogen compounds and lignophenols, plasticizers, dispersants such as organic metal salts, lubricants such as fatty acid amides, metal deactivators such as nitrogen compounds, polyolefin resins other than the polypropylene resins, thermoplastic resins such as polyamide resins and polyester resins, and elastomers (rubber components) such as olefin elastomers and styrene elastomers.
These optional components may be used in combination of two or more kinds.

Colorants such as inorganic or organic pigments are effective in imparting or improving the colored appearance, appearance, texture, commercial value, weather resistance, durability, etc. of polypropylene resin compositions and molded articles thereof.
Specific examples of inorganic pigments include carbon black such as furnace carbon and ketjen carbon; titanium oxide; iron oxide (e.g., red iron oxide); chromic acid (e.g., yellow lead); molybdic acid; selenide sulfide; and ferrocyanide. Specific examples of organic pigments include azo pigments such as sparingly soluble azo lake, soluble azo lake, insoluble azo chelate, condensed azo chelate, and other azo chelates; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; threne pigments such as anthraquinone, perinone, perylene, and thioindigo; dye lake; quinacridone; dioxazine; and isoindolinone. In order to achieve a metallic or pearlescent look, aluminum flakes and pearl pigments can be added. Dyes can also be added.

Light stabilizers and ultraviolet absorbers, for example, hindered amine compounds, benzotriazoles, benzophenones, and salicylates, are effective in imparting or improving the weather resistance, durability, and the like of polypropylene resin compositions and molded articles thereof, and are effective in further improving weather discoloration resistance.
Specific examples of the hindered amine compound include a condensation product of dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine; poly[[6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]]; tetrakis(2,2,6,6-tetramethyl-4-piperidyl)1,2,3,4-butane tetracarboxylate; tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)1,2,3,4-butane tetracarboxylate; bis(1,2,2,6,6-pentamethoxy) 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole;2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole;2-hydroxy-4-methoxybenzophenone;2-hydroxy-4-n-octoxybenzophenone; and the like. Examples of the salicylate-based compounds include 4-t-butylphenyl salicylate; 2,4-di-t-butylphenyl 3',5'-di-t-butyl-4'-hydroxybenzoate; and the like.
Here, the method of using the light stabilizer and the ultraviolet absorber in combination is preferable because it has a large effect of improving weather resistance, durability, weather discoloration resistance, and the like.

As the antioxidant, for example, a phenol-based, phosphorus-based or sulfur-based antioxidant is effective in imparting or improving heat resistance, processing stability, heat aging resistance, etc. to a polypropylene resin composition and a molded article thereof.
Furthermore, antistatic agents such as nonionic and cationic antistatic agents are effective in imparting and improving antistatic properties to polypropylene resin compositions and molded articles thereof.

Examples of olefin-based elastomers include ethylene-α-olefin copolymer elastomers such as ethylene-propylene copolymer elastomer (EPR), ethylene-butene copolymer elastomer (EBR), ethylene-hexene copolymer elastomer (EHR), and ethylene-octene copolymer elastomer (EOR); ethylene-α-olefin-diene terpolymer elastomers such as ethylene-propylene-ethylidenenorbornene copolymer, ethylene-propylene-butadiene copolymer, and ethylene-propylene-isoprene copolymer; and styrene-butadiene-styrene triblock copolymer elastomer (SBS).
Examples of the styrene-based elastomer include styrene-based elastomers such as styrene-isoprene-styrene triblock copolymer elastomer (SIS), styrene-ethylene-butylene copolymer elastomer (SEB), styrene-ethylene-propylene copolymer elastomer (SEP), styrene-ethylene-butylene-styrene copolymer elastomer (SEBS), styrene-ethylene-butylene-ethylene copolymer elastomer (SEBC), hydrogenated styrene-butadiene elastomer (HSBR), styrene-ethylene-propylene-styrene copolymer elastomer (SEPS), styrene-ethylene-ethylene-propylene-styrene copolymer elastomer (SEEPS), styrene-butadiene-butylene-styrene copolymer elastomer (SBBS), partially hydrogenated styrene-isoprene-styrene copolymer elastomer, and partially hydrogenated styrene-isoprene-butadiene-styrene copolymer elastomer, as well as hydrogenated polymer-based elastomers such as ethylene-ethylene-butylene-ethylene copolymer elastomer (CEBC).
Among these, the use of an ethylene-octene copolymer elastomer (EOR) and/or an ethylene-butene copolymer elastomer (EBR) is preferred since it is easy to impart appropriate flexibility and the like to the polypropylene resin composition of the present invention and a molded article thereof, and they tend to have excellent impact resistance.

<Method for producing resin compositions (A) and (B)>
The resin compositions (A) and (B) according to the present invention are resin compositions for producing the integrally molded article of the present invention, and contain (a) a resin such as a thermoplastic resin, a modified polyolefin resin added as necessary, (b) a thermally expandable flame retardant, and (c) a dispersant. Optionally added components may also be blended. In the thermoplastic resin compositions (A) and (B), when the thermoplastic resin (a) is a polypropylene resin (a-1), the composition may be referred to as a polypropylene resin composition (hereinafter, sometimes referred to as a "PP composition").
The thermoplastic resin compositions (A) and (B) or the PP composition can be produced by a conventional method, and can be produced by blending, mixing, and melt-kneading the above-mentioned components.
The mixing is carried out using a mixer such as a tumbler, a V blender, or a ribbon blender, and the melt kneading is carried out using equipment such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll mixer, a Brabender plastograph, or a kneader, and the materials are melt kneaded and granulated.

<Method of manufacturing a sheet for manufacturing an integrally molded body>
Regarding the sheet for producing the integrally molded body of the present invention, the manufacturing method thereof is not particularly limited, but it is preferable to produce it by impregnating a mat made of inorganic fibers (hereinafter sometimes referred to as "inorganic fiber mat") with the above-mentioned thermoplastic resin composition or PP composition. In the present invention, there are a fiber reinforced resin member (1) using an inorganic fiber material (X) and a fiber reinforced resin member (2) using an inorganic fiber material (Y), but both are manufactured by the same method, and here, the inorganic fiber material (X) and the inorganic fiber material (Y) are collectively referred to as an inorganic fiber mat.
Methods of impregnation include a method of applying the thermoplastic composition or the PP composition to the inorganic fiber mat, and a method of preparing a sheet of the thermoplastic resin composition or the PP composition (hereinafter sometimes referred to as a "thermoplastic resin sheet" or a "PP sheet"), laminating the thermoplastic resin sheet or the PP sheet on the inorganic fiber mat, and heating and melting the same to impregnate the inorganic fiber mat.
In the present invention, from the viewpoint of the impregnation of the resin into the fibers in the sheet for producing the integrally molded body, a method of laminating a thermoplastic resin sheet or a PP sheet on an inorganic fiber mat and heating and melting it is preferable. In particular, the integrally molded body can be obtained by laminating the inorganic fiber mat between two thermoplastic resin sheets or PP sheets, thereafter heating and pressing the laminate, and then cooling and solidifying it.
The thickness of the thermoplastic resin sheet or PP sheet is not particularly limited as long as it allows good impregnation of the fiber mat.

(Inorganic fiber mat)
The form of the inorganic fibers used in the method for producing a sheet for producing an integrally molded body is not particularly limited, and various forms can be used, but it is preferable that the inorganic fibers are formed into a mat or sheet shape.
More specifically, a mat formed from glass fibers (hereinafter referred to as a "glass fiber mat") and a mat formed from metal oxide fibers such as alumina fibers (hereinafter referred to as a "metal oxide mat") are preferred.

The basis weight (mass per unit area) of the inorganic fiber mat is not particularly limited and is appropriately determined depending on the application, but is preferably 300 g/m ² or more, more preferably more than 800 g/m ² , and more preferably more than 1500 g/m ^2. The basis weight of the inorganic fiber mat is not particularly limited, but is preferably 5000 g/m ² or less, more preferably 4500 g/m ² or less, even more preferably 4000 g/m ² or less, and particularly preferably 3500 g/m ² or less.

The basis weight per unit area of the inorganic fiber mat can be set within the above range by adjusting the amount of fiber per unit area when the inorganic fiber aggregates that make up the inorganic fiber mat are stacked using a folding device. The inorganic fiber mat of the present invention may be composed of multiple inorganic fiber mats bonded together or may be composed of a single material, but is preferably composed of a single material in terms of handling properties and peel strength at the adhesive interface.

(fiberglass mat)
The form of the glass fiber mat used in the present invention includes felt and blanket processed with short fiber glass wool, chopped strand mat processed with continuous glass fiber, swirl (spiral) mat of continuous glass fiber, unidirectionally aligned mat, etc. Among these, the use of a glass fiber mat obtained by needle punching a swirl (spiral) mat of continuous glass fiber is particularly preferable because the stampable sheet has excellent strength and impact resistance.

(Metal oxide fiber mat)
The metal oxide fiber mat according to the present invention is a mat that is made of metal oxide fibers such as alumina fibers and that has been subjected to a needling treatment.

In the method of laminating a thermoplastic resin sheet or a PP sheet on an inorganic fiber mat and heating and melting it, the heating temperature is preferably 170 to 300° C. When the heating temperature is 170° C. or higher, the fluidity of the polypropylene resin is sufficient, and the inorganic fiber mat can be sufficiently impregnated with the PP composition, and suitable fiber reinforced resin members (1) and (2) can be obtained. On the other hand, when the heating temperature is 300° C. or lower, the thermoplastic resin composition or the PP composition does not deteriorate.
Furthermore, the pressurizing pressure is preferably 0.1 to 1 MPa. When the pressurizing pressure is 0.1 MPa or more, the inorganic fiber mat can be sufficiently impregnated with the thermoplastic resin composition or the PP composition, and the fiber reinforced resin member (1) and the fiber reinforced resin member (2) can be obtained. On the other hand, when the pressurizing pressure is 1 MPa or less, the thermoplastic resin composition or the PP composition flows, and no burrs are generated.
The cooling temperature is not particularly limited as long as it is equal to or lower than the freezing point of the thermoplastic resin in the thermoplastic resin composition or the PP composition, but if the cooling temperature is equal to or lower than 80° C., the obtained fiber reinforced resin member (1) and fiber reinforced resin member (2) will not be deformed when taken out. From the above viewpoints, the cooling temperature is preferably room temperature to 80° C.

Methods for obtaining the fiber-reinforced resin member (1) and the fiber-reinforced resin member (2) by heating and pressurizing the above-mentioned laminate and cooling the laminate include a method for press-molding the laminate in a mold equipped with a heating device, and a lamination process in which the laminate is heated and pressurized by passing it between two pairs of rollers equipped with a heating device. In particular, the lamination process is preferable because it allows continuous production and has good productivity.

<Thickness of fiber reinforced resin member>
The thickness of the fiber reinforced resin member of the present invention is usually 1 to 10 mm, preferably 2 to 5 mm. When the thickness of the fiber reinforced resin member is 1 mm or more, the fiber reinforced resin member is easy to manufacture, while when the thickness of the fiber reinforced resin member is 10 mm or less, long-term preheating is not required when processing the fiber reinforced resin member by stamping molding or the like, and good molding processability is obtained.
The thickness ratio of the fiber-reinforced members (A) and (B) can be appropriately determined depending on the required physical properties.

<Integral molding>
The fiber-reinforced resin member of the present invention can be molded into a desired shape by stamping according to a conventional method to obtain an integrally molded body made of the fiber-reinforced resin member. Specifically, the fiber-reinforced resin members (1) and (2) are prepared in advance, and the fiber-reinforced resin member (2) is placed over the entire surface or at a desired location during stamping to obtain an integrally molded body.

(Application)
The applications of the integrally molded article of the present invention include, for example, various parts in the industrial field such as automobile parts and electrical and electronic equipment parts. In particular, since it has excellent strength, rigidity, and electrical conductivity, and is also excellent in processability, it can be suitably used for applications requiring a good balance of these performances, such as various housings and cases such as battery cases.

[battery pack]
The present invention also provides a battery pack equipped with the battery housing made of the above-mentioned integrally molded body.
The battery pack of the present invention will be described with reference to FIG.

3 is a conceptual diagram showing a battery pack of the present invention. The battery pack 20 of the present invention includes a battery module which is an assembly of a plurality of battery cells (single batteries) 21, and a battery housing for storing these. The battery housing has an undercase 23 for storing the battery module, and a cover material made of the integrally molded body 10 of the present invention. The battery cell 21 includes a discharge valve 22 which opens when the internal pressure exceeds a set pressure.
The battery pack of the present invention is characterized in that a fiber reinforced member (2) 12 is partially disposed at a position facing the discharge port of the discharge valve of the battery cell 21. By disposing the fiber reinforced member (2) 12 at a position facing the discharge port of the discharge valve 22 in this manner, thermal damage due to high-temperature ejected material can be prevented, and safety can be improved.

The battery used in the battery pack of the present invention is not particularly limited. Examples include secondary batteries such as lithium ion batteries, nickel-metal hydride batteries, lithium-sulfur batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, sodium-sulfur batteries, lead-acid batteries, and air batteries. Of these, lithium ion batteries are preferred.

<Battery housing structure>
The thickness of the battery housing in the battery pack 20 of the present invention is not particularly limited, but is preferably 0.5 mm or more, more preferably 1.0 mm or more, and even more preferably 2.0 mm or more. If it is equal to or more than the above lower limit, it is preferable in terms of moldability, mechanical strength, and flame resistance. In addition, the thickness of the battery housing is preferably 10 mm or less, more preferably 8 mm or less, and particularly preferably 6 mm or less. If it is equal to or less than the above upper limit, it is preferable in terms of the size of the space in which it is installed, the weight reduction, and moldability.

<Battery housing manufacturing method>
The battery housing of the present invention can be manufactured by various methods, but press molding is preferred from the viewpoint of productivity. In the press molding, it is preferable to prepare a sheet for forming the integrally molded body of the present invention, stack a plurality of sheets, and press mold the stacked sheets.

The first aspect of the present invention will be described in detail below using examples, but the present invention is not limited to these examples.
(Evaluation method)
1. Evaluation of flame barrier properties For the sheets for forming molded bodies prepared in each Example and Comparative Example, a flame from a burner at 1300°C was applied from one surface, and after 15 minutes, the flame was evaluated based on whether it penetrated. The distance from the burner nozzle to the sample was 160 mm. The flame surface was set to 1200°C. The flame surface temperature was confirmed with a thermocouple thermometer.
In the above flame-proofing evaluation, the temperature of the surface (back surface) opposite to the surface exposed to the burner flame of the test piece was measured with a non-contact radiation thermometer (FT-H50K manufactured by Keyence Corporation). The measurement area was φ35 mm. The center of the measurement area was visually set to be directly above the position of the burner flame. Table 1 shows the maximum temperature (°C) of the back surface up to 600 seconds and the elapsed time (seconds) when the back surface temperature first reached 500°C.

(Materials used)
1. Polypropylene resin (component a)
"Novatec PP SA06GA" (melt flow rate: 60 g/10 min) manufactured by Japan Polypropylene Corporation was used.

2. Thermally expandable flame retardant (component b)
Phosphorus-based flame retardant composition (ADEKA CORPORATION, Adeka STAB FP-2500S, containing 50 to 60 mass% piperazine pyrophosphate, 35 to 45 mass% melamine pyrophosphate, and 3 to 6 mass% zinc oxide based on the total mass of the phosphorus-based flame retardant composition)

3. Dispersant (component c)
α-Olefin/maleic anhydride copolymer (Mitsubishi Chemical Corporation, Diacalna 30M, weight average molecular weight 7,800).

4. Fiber 4-1 Glass fiber mat (inorganic fiber material (X))
A glass fiber mat (elongation at maximum load: 11%) was used, which was needle-punched from a swirl mat (basis weight 880 g/m ² ) made from continuous glass fibers (fiber diameter 23 μm) of roving.
The elongation of the glass fiber mat at maximum load was measured by the following method.
(Elongation at maximum load)
A sample piece of glass fiber mat measuring 250 mm x 25 mm was prepared. Both ends of the sample were fixed with chucks using an AUTOGRAPH "AG-10TA" (manufactured by Shimadzu Corporation). The test was carried out in tension mode at a speed of 200 mm/min. The displacement and load values were measured, and the sample elongation (strain) at the maximum load was calculated.
4-2 Glass fiber fabric (inorganic fiber material (Y))
A glass fiber fabric (weight per unit area: 600 g/m ² , elongation at maximum load: 1.0%) was used.
The elongation was calculated in the same manner as for the glass fiber mat described above.

Preparation Example 1 (Preparation of PP Composition)
The above components a, b, and c were mixed in proportions of 68 mass %, 30 mass %, and 2 mass %, respectively, and melt-kneaded (230° C.) to prepare pellets of a polypropylene resin composition (PP composition).

Comparative Preparation Example 1
Pellets of a polypropylene resin composition (PP composition) were prepared in the same manner as in Preparation Example 1, except that the components b and c were not used.

Production Example 1
The pellets of the PP composition granulated in Preparation Example 1 were put into an extruder, melted, and then extruded into a sheet. The extruded sheet-like PP (hereinafter sometimes referred to as "PP sheet") and a glass fiber mat (nonwoven fabric) were laminated with the PP sheet as the outermost layer and the glass fiber mat (nonwoven fabric) being supplied between them, and then heated and pressed at 230°C for 4 minutes while applying a pressure of 0.3 MPa using a laminator, and then cooled and solidified to obtain a resin sheet (thickness: 3.8 mm). The PP sheet was impregnated into the glass fiber mat to obtain an integrated sheet (fiber reinforced resin member (1)). The weight ratio of the PP sheet to the glass fiber mat was PP sheet:glass fiber mat=6:4. Hereinafter, this is referred to as sheet A. The composition of sheet A is shown in Table 1.

Production Example 2
A sheet (fiber reinforced resin member (1)) was obtained in the same manner as in Production Example 1, except that the pellets of the PP composition granulated in Comparative Preparation Example 1 were used instead of the pellets of the PP composition granulated in Preparation Example 1. The weight ratio of the PP sheet to the glass fiber mat was PP sheet:glass fiber mat=6:4. Hereinafter, this will be referred to as Sheet B. The composition of Sheet B is shown in Table 1.

Production Example 3
The pellets of the PP composition granulated in Preparation Example 1 were put into an extruder, melted, and then extruded into a sheet to obtain an extruded sheet-like PP sheet. A glass fiber fabric was laminated on both sides so as to sandwich the PP sheet, to obtain a laminate. Furthermore, a PP sheet 21 was laminated on both sides so as to sandwich the laminate, so as to be the outermost layer. Next, the laminate was heated and pressed at 230° C. for 6 minutes while applying a pressure of 0.3 MPa using a laminator, and then cooled and solidified to obtain a fiber-reinforced composite material (thickness: 1.5 mm). A sheet (fiber-reinforced resin member (2)) having an integrated layer was obtained, in which a part of the PP sheet was impregnated with the glass fiber fabric. The weight ratio of the PP sheet to the glass fiber fabric was PP sheet:glass fiber fabric=3:7. Hereinafter, this is referred to as sheet C. The composition of sheet C is shown in Table 1.

Production Example 4
A sheet (fiber reinforced resin member (2)) was obtained in the same manner as in Production Example 3, except that in Production Example 3, pellets of the PP composition granulated in Comparative Preparation Example 1 were used instead of the pellets of the PP composition granulated in Preparation Example 1. The weight ratio of the PP sheet to the glass fiber fabric was PP sheet:glass fiber fabric=3:7. Hereinafter, this will be referred to as Sheet D. The composition of Sheet D is shown in Table 1.

Example 1
The above-mentioned sheet A (fiber reinforced resin member (1)) and sheet C (fiber reinforced resin member (2)) were heated to a material temperature of 210 ° C., and the fiber reinforced resin member (2) was placed in a mold so that the area ratio of the fiber reinforced resin member (2) to the fiber reinforced resin member (1) was 1: 1 (fiber reinforced resin member (2): fiber reinforced resin member (1)). The fiber reinforced resin member (2) was placed on top of the fiber reinforced resin member (1) 11 at a surface pressure of 200 kg / cm ² for 60 seconds, and an integrally molded body 10 in which the fiber reinforced resin member (2) 12 was entirely disposed on the fiber reinforced resin member (1) 11 as shown in FIG. 1 was obtained. The thickness of the integrally molded body was 2.5 mm. A flame-shielding test was performed on the surface of the sheet A side of the obtained integrally molded body. The results of the evaluation by the above method are shown in Table 2.

Example 2
The evaluation was carried out in the same manner as in Example 1, except that the flame-proofing test was carried out on the surface of the obtained integrally molded body on the side of sheet C. The thickness of the integrally molded body was 2.5 mm. The results of the evaluation by the above method are shown in Table 2.

Example 3
The above-mentioned sheet B (fiber reinforced resin member (1)) and sheet C (fiber reinforced resin member (2)) were heated to a material temperature of 210 ° C., and the fiber reinforced resin member (2) was placed in a mold so that the area ratio of the fiber reinforced resin member (2) to the fiber reinforced resin member (1) was 1: 1 (fiber reinforced resin member (2): fiber reinforced resin member (1)). The fiber reinforced resin member (2) was placed on top of the fiber reinforced resin member (1) 11 at a surface pressure of 200 kg / cm ² for 60 seconds, and an integrally molded body 10 in which the fiber reinforced resin member (2) 12 was entirely disposed on the fiber reinforced resin member (1) 11 as shown in FIG. 1 was obtained. The thickness of the integrally molded body was 2.5 mm. A flame-shielding test was performed on the surface of the sheet B side of the obtained integrally molded body. The results of the evaluation by the above method are shown in Table 2.

Example 4
Evaluation was performed in the same manner as in Example 3, except that a flame-proofing test was performed on the surface of the obtained integrally molded body on the side of sheet C. The thickness of the integrally molded body was 2.5 mm. The results of the evaluation by the above method are shown in Table 2.

Example 5
The above-mentioned sheet A (fiber reinforced resin member (1)) and sheet D (fiber reinforced resin member (2)) were heated to a material temperature of 210 ° C., and the fiber reinforced resin member (2) was placed on top of the fiber reinforced resin member (1) so that the area ratio of the fiber reinforced resin member (2) was 1:1 (fiber reinforced resin member (2): fiber reinforced resin member (1)). The fiber reinforced resin member (2) was placed on top of the fiber reinforced resin member (1) 11 at a surface pressure of 200 kg / cm ² for 60 seconds, and an integrally molded body 10 in which the fiber reinforced resin member (2) 12 was entirely disposed on the fiber reinforced resin member (1) 11 as shown in FIG. 1 was obtained. The thickness of the integrally molded body was 2.5 mm. A flame-shielding test was performed on the surface of the sheet A side of the obtained integrally molded body. The results of the evaluation by the above method are shown in Table 2.

Example 6
The evaluation was carried out in the same manner as in Example 5, except that the flame-proofing test was carried out on the surface of the obtained integrally molded body on the side of sheet D. The thickness of the integrally molded body was 2.5 mm. The results of the evaluation by the above method are shown in Table 2.

Comparative Example 1
The above-mentioned sheet B (fiber reinforced resin member (1)) and sheet D (fiber reinforced resin member (2)) were heated to a material temperature of 210°C, and the fiber reinforced resin member (2) was superimposed on the fiber reinforced resin member (1) so that the area ratio of the fiber reinforced resin member (2) to the fiber reinforced resin member (1) was 1:1 (fiber reinforced resin member (2): fiber reinforced resin member (1)), and press molded to obtain an integrally molded body 10 in which the fiber reinforced resin member (2) 12 is entirely disposed on the fiber reinforced resin member (1) 11 as shown in FIG. 1. A flame-proofing test was performed on the surface of the sheet B side of the obtained integrally molded body. The results of the evaluation by the above method are shown in Table 2.

Comparative Example 2
Except for carrying out a flame-proofing test on the surface of the obtained integrally molded body on the side of sheet D, evaluation was carried out in the same manner as in Comparative Example 1. The results of evaluation by the above-mentioned method are shown in Table 2.

As shown in Examples 1 to 6, the integrally molded body of the present invention has excellent flame-blocking properties, and the flame was blocked even after 15 minutes. On the other hand, the flame penetrated to the back surface of Comparative Example 1 at 140 seconds and Comparative Example 2 at 106 seconds.

The integrally molded body of the present invention has high flame resistance and strength. Therefore, it is useful as a material for various industrial parts that require high safety, such as aircraft, ships, automobile parts, electrical and electronic equipment parts, and building materials. In particular, it can be suitably used for various battery housings and cases that have traditionally been made of metal, and is expected to contribute to the safety of automobiles, as well as improve energy efficiency and reduce _CO2 emissions by reducing weight.
In particular, the battery pack using the integrally molded body of the present invention can improve safety by preventing thermal damage caused by high-temperature ejection due to the function of the fiber-reinforced resin member (2), and also ensures flame resistance and heat resistance due to the functions of the fiber-reinforced resin members (1) and (2). Furthermore, when the fiber-reinforced member (2) is partially provided, the function of the fiber-reinforced member (1) is fully exerted, and it is expected that the molding processability will also be excellent.

10 Integral molded body 11 Fiber reinforced resin member (1)
12 Fiber reinforced resin member (2)
20 Battery pack 21 Battery cell 22 Discharge valve 23 Undercase

Claims (15)

An integrally molded body consisting of a plurality of members,
The present invention includes at least a fiber-reinforced resin member (1) in which an inorganic fiber material (X) and a resin composition (A) are integrated together, and a fiber-reinforced resin member (2) in which an inorganic fiber material (Y) and a resin composition (B) are integrated together,
the elongation of the inorganic fiber material (Y) at maximum load is smaller than the elongation of the inorganic fiber material (X) at maximum load;
At least one of the resin composition (A) and the resin composition (B) contains a thermally expandable flame retardant. The integrally molded body according to claim 1, wherein the inorganic fiber material (Y) has an elongation of 5% or less at maximum load. The integrally molded body according to claim 1, wherein the inorganic fiber material (X) has an elongation of more than 5% at maximum load. The integrally molded body according to claim 1, wherein the inorganic fiber material (X) is an inorganic fiber nonwoven fabric. The integrally molded body according to claim 1, wherein the inorganic fiber material (Y) is an inorganic fiber fabric. The integrally molded body according to claim 1, wherein the resins constituting the resin compositions (A) and (B) include a thermoplastic resin. The integrally molded body according to claim 1, wherein the thermally expandable flame retardant is a phosphorus-based flame retardant. The integrally molded body according to claim 1, wherein the resin composition (A) and/or (B) containing the thermally expandable flame retardant further contains a dispersant. The integrally molded body according to claim 8, wherein the dispersant is a copolymer of an α-olefin and an unsaturated carboxylic acid. The integrally molded body according to claim 8, wherein the content of the dispersant per 100 parts by mass of the thermally expandable flame retardant is more than 0 and not more than 25 parts by mass. The integrally molded body according to claim 4, wherein the inorganic fibers constituting the inorganic fiber nonwoven fabric are at least one type selected from glass fibers, ceramic fibers, metal fibers, and metal oxide fibers. The integrally molded body according to claim 5, wherein the inorganic fibers constituting the inorganic fiber fabric are at least one type selected from glass fibers, ceramic fibers, metal fibers, and metal oxide fibers. The integrally molded body according to claim 6, wherein the thermoplastic resin is a polypropylene-based resin, and the content of the polypropylene-based resin is 15 to 80 mass% based on the total weight. The integrally molded body according to claim 1, wherein the content of the thermally expandable flame retardant is 1 to 30 mass % based on the total weight. A plurality of battery cells each having a discharge valve that opens when the internal pressure exceeds a set pressure;
a battery housing that houses the battery cell;
The battery housing is made of the integrally molded body according to any one of claims 1 to 14,
The fiber reinforced resin member (2) is partially disposed at a position facing a discharge port of a discharge valve of the battery cell.