Laminate

Abstract

A laminate provided with a layer (A) in which inorganic fibers (Y) and a thermoplastic resin composition (X) are integrated, and a layer (B) having a higher thermal conductivity in the thickness direction than the layer (A), the thermoplastic resin composition (X) containing a thermoplastic resin (a) and a thermally expandable flame retardant (b1). The present invention can provide a laminate having high flame shielding properties.

Description

Technical Field

[0001] The present invention relates to a laminate, and more particularly to a laminate having flame barrier properties. Background Art

[0002] In recent years, as part of environmental protection measures, research and development of electric vehicles and hybrid vehicles are being promoted, and high-energy-density battery development and lightweighting are being actively promoted to increase the cruising range. Such high-energy-density batteries have the potential to catch fire due to accidents. As a safety measure for passengers, the shell material needs to have high flame shielding properties. Therefore, in many cases, metal materials such as iron and refractory materials are used in combination.

[0003] However, metal materials have the disadvantage of being heavy, and when used in combination with refractory materials, processability and increased costs due to the increase in the number of parts become problems. Therefore, attempts have been made to make resins that can take into account both lightweight and flame shielding properties. Currently, in a society oriented towards sustainable development, the suppression of carbon dioxide and recyclability are gradually gaining attention. Thermosetting materials often have high flame retardancy and are very common as composite materials, but from the perspective of recyclability, thermoplastic resin raw materials are advantageous.

[0004] In addition, China has issued safety standards such as GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles", which stipulates that a warning must be issued 5 minutes before the battery's thermal runaway. It can be assumed that this can also be achieved through the shell material that shields the flame for more than 5 minutes after the battery catches fire.

[0005] To address these problems, for example, Patent Document 1 proposes a material in which a bromine-based flame retardant or an antimony oxide compound is added to a carbon fiber-reinforced polypropylene resin. However, the additives used here have a problem in terms of biopersistence.

[0006] In contrast, Patent Document 2 proposes a flame-retardant polyolefin composition containing a (poly)phosphate compound in a polyolefin resin as a technique for flame-retarding a polypropylene resin in consideration of biopersistence.

[0007] In addition, Patent Document 3 proposes a flame-retardant resin composition comprising long glass fibers and a phosphate compound contained in a polypropylene resin.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2014-62189

[0011] Patent Document 2: Japanese Patent Application Publication No. 2013-119575

[0012] Patent Document 3: Japanese Patent Application Publication No. 2011-88970 Summary of the invention

[0013] Problems to be solved by the invention

[0014] As described above, the prior art has many deficiencies in terms of resinization that can achieve both lightweight and flame barrier properties for batteries with high energy density. Specifically, higher flame barrier properties are required.

[0015] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a laminate having high flame barrier properties.

[0016] Solutions to the problem

[0017] The present inventors have conducted intensive studies to solve the above-mentioned problems and have found that a laminate comprising a layer (A) in which a thermoplastic resin composition (X) and an inorganic fiber (Y) are integrated, and a layer (B) having a higher thermal conductivity in the thickness direction than that of the layer (A) can solve the above-mentioned problems, and based on these findings, the present invention has been completed.

[0018] That is, the present invention provides the following [1] to

[16] . It should be noted that the aspects described in the following [1] to

[16] may be described as the first aspect.

[0019] [1] A laminate comprising:

[0020] A layer (A) in which a thermoplastic resin composition (X) and an inorganic fiber (Y) are integrated, and

[0021] The thermal conductivity of layer (B) in the thickness direction is higher than that of layer (A).

[0022] The thermoplastic resin composition (X) comprises a thermoplastic resin (a) and a heat-expandable flame retardant (b1).

[0023] [2] The laminate according to [1] above, wherein

[0024] The thermal conductivity of the laminate measured in the thickness direction is 0.32 W / mK or more.

[0025] [3] The laminate according to [1] or [2] above, wherein

[0026] The thermal conductivity of the layer (B) measured in the thickness direction is 10 W / mK to 400 W / mK.

[0027] [4] The laminate according to any one of [1] to [3] above, wherein

[0028] The above-mentioned layer (B) is a metal layer.

[0029] [5] The laminate according to [4] above, wherein

[0030] The thickness of the metal layer is 0.05-2.0 mm.

[0031] [6] The laminate according to any one of [1] to [5] above, wherein

[0032] The thermoplastic resin composition (X) contains a polypropylene-based resin.

[0033] [7] The laminate according to any one of [1] to [6] above, wherein

[0034] The thermoplastic resin composition (X) comprises a copolymer of an α-olefin and an unsaturated carboxylic acid.

[0035] [8] The laminate according to any one of [1] to [7] above, wherein

[0036] The heat-expandable flame retardant (b1) contains a phosphorus-based flame retardant.

[0037] [9] The laminate according to [8] above, wherein

[0038] The phosphorus-based flame retardant includes a compound having a melamine structure or a piperazine structure.

[0039]

[10] The laminate according to any one of [1] to [9] above, wherein

[0040] The inorganic fibers (Y) include glass fibers.

[0041]

[11] The laminate according to any one of [1] to

[10] above, wherein the inorganic fibers (Y) are impregnated with the thermoplastic resin composition for mat (X).

[0042]

[12] The laminate according to any one of [1] to

[11] above, wherein

[0043] The thermoplastic resin composition (X) contains zinc oxide.

[0044]

[13] A method for manufacturing a laminate, comprising:

[0045] A step of impregnating a mat composed of inorganic fibers (Y) with a thermoplastic resin composition (X) to produce an integrated layer (A), and a step of laminating a layer (B) having a higher thermal conductivity in the thickness direction than the layer (A) on the integrated layer (A).

[0046]

[14] The method for producing a laminate according to

[13] above, wherein:

[0047] In the step of producing the integrated layer (A), a mat composed of inorganic fibers (Y) and a resin sheet composed of the thermoplastic resin composition (X) are stacked and hot-pressed.

[0048]

[15] The method for producing a laminate according to

[13] or

[14] , wherein:

[0049] The above-mentioned layer (B) is a metal layer.

[0050]

[16] A housing or a frame using the laminate according to any one of [1] to

[12] above.

[0051] In addition, the stampable sheet described in any one of the following [1'] to [11'] is also one of the aspects of the present invention. This aspect may be described as the second aspect.

[0052] Furthermore, a laminate including a layer formed by molding the above-mentioned punchable sheet and a metal layer is also one of the aspects of the present invention (corresponding to the following [12'] to [22']).

[0053] [1'] A punchable sheet comprising a thermoplastic resin composition (X) and an inorganic fiber (Y),

[0054] The thermoplastic resin composition (X) contains a heat-expandable flame retardant (b1), and the inorganic fibers (Y) contain glass fibers.

[0055] [2'] The punchable sheet according to [1'] above, wherein:

[0056] The heat-expandable flame retardant (b1) contains a phosphorus-based flame retardant.

[0057] [3'] The punchable sheet according to [2'] above, wherein:

[0058] The phosphorus-based flame retardant includes a compound having a melamine structure or a piperazine structure.

[0059] [4'] The punchable sheet according to any one of [1'] to [3'] above, which is formed by impregnating the thermoplastic resin composition (X) for mats formed of the inorganic fibers (Y).

[0060] [5'] The punchable sheet according to any one of [1'] to [4'] above, wherein

[0061] The thermoplastic resin composition (X) contains zinc oxide.

[0062] [6'] The punchable sheet according to any one of [1'] to [5'] above, wherein

[0063] The above-mentioned thermoplastic resin composition (X) contains a thermoplastic resin (a) and a flame retardant or flame retardant auxiliary (b2) different from the heat-expandable flame retardant (b1), and the decomposition temperature of the flame retardant or flame retardant auxiliary (b2) is higher than the thermal expansion starting temperature of the heat-expandable flame retardant (b1) by 10°C or more.

[0064] [7'] The punchable sheet according to [6'] above, wherein:

[0065] The flame retardant or flame retardant auxiliary (b2) is a non-thermal expansion flame retardant or a non-thermal expansion flame retardant auxiliary (b2').

[0066] [8'] The punchable sheet according to [7'] above, wherein:

[0067] The non-heat-expandable flame retardant or the non-heat-expandable flame retardant auxiliary (b2') contains a metal hydroxide.

[0068] [9'] The punchable sheet according to any one of [6'] to [8'] above, wherein:

[0069] The flame retardant or flame retardant auxiliary (b2) is a fluorine-based anti-dripping agent.

[0070] [10'] The punchable sheet according to any one of [1'] to [9'] above, wherein:

[0071] The thermoplastic resin composition (X) comprises a copolymer of an α-olefin and an unsaturated carboxylic acid.

[0072] [11'] The punchable sheet according to any one of [6'] to [10'] above, wherein:

[0073] The thermoplastic resin (a) includes a polypropylene-based resin.

[0074] [12'] A laminate comprising:

[0075] A layer formed by forming a punchable sheet as described in any one of [1'] to [11'], and

[0076] Metal layer.

[0077] [13'] The laminate according to [12'] above, wherein

[0078] The thermal conductivity of the laminate measured in the thickness direction is 0.32 W / mK or more.

[0079] [14'] A laminated body comprising:

[0080] A layer (A) in which a thermoplastic resin composition (X) and an inorganic fiber (Y) are integrated, and

[0081] The thermal conductivity of layer (B) in the thickness direction is higher than that of layer (A).

[0082] The thermoplastic resin composition (X) comprises a thermoplastic resin (a) and a heat-expandable flame retardant (b1).

[0083] [15'] The laminate according to [14'] above, wherein

[0084] The thermal conductivity of the laminate measured in the thickness direction is 0.32 W / mK or more.

[0085] [16'] The laminate according to [14'] or [15'] above, wherein

[0086] The thermal conductivity of the layer (B) measured in the thickness direction is 10 W / mK to 400 W / mK.

[0087] [17'] The laminate according to any one of [14'] to [16'] above, wherein

[0088] The above-mentioned layer (B) is a metal layer.

[0089] [18'] The laminate according to any one of [14'] to [17'] above, wherein

[0090] The thermoplastic resin composition (X) contains a polypropylene-based resin.

[0091] [19'] The laminate according to any one of [14'] to [18'] above, wherein

[0092] The thermoplastic resin composition (X) comprises a copolymer of an α-olefin and an unsaturated carboxylic acid.

[0093] [20'] The laminate according to any one of [14'] to [19'] above, wherein

[0094] The thermally expandable flame retardant (b1) contains a phosphorus-based flame retardant.

[0095] [21'] The laminate according to [20'] above, wherein

[0096] The phosphorus-based flame retardant includes a compound having a melamine structure or a piperazine structure.

[0097] [22'] The laminate according to any one of [14'] to [21'] above, wherein

[0098] The inorganic fibers (Y) include glass fibers.

[0099] Effects of the Invention

[0100] According to the present invention, a laminate having high flame barrier properties can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Figure 1 Schematic diagram showing the punchable sheet used in Example 1.

[0102] Explanation of symbols

[0103] 10 stamping sheets

[0104] 11PP sheet

[0105] 12 Fiberglass Mat

[0106] 13PP sheet DETAILED DESCRIPTION

[0107] Hereinafter, an embodiment (first embodiment) of the present invention will be described in detail. However, the following description is an example of the embodiment of the present invention, and the present invention is not limited to these contents at all.

[0108] [Laminated body]

[0109] The laminate of the present invention is characterized in that it comprises: a layer (A) formed by integrating a thermoplastic resin composition (X) and an inorganic fiber (Y), and a layer (B) having a higher thermal conductivity in the thickness direction than that of the layer (A). Here, the layer (A) is a layer formed by integrating the thermoplastic resin composition (X) and the inorganic fiber (Y). Integration means that the thermoplastic resin composition (X) and the inorganic fiber (Y) form a structure, for example, the following modes (1) to (4) can be cited.

[0110] Examples include (1) a layer obtained by extrusion molding or injection molding a composition in which the inorganic fibers (Y) are dispersed in a thermoplastic resin composition (X).

[0111] Examples include (2) a state in which a layer formed of a thermoplastic resin composition (X) and a layer formed of inorganic fibers (Y) are stacked and bonded. As a form of the bonded state, for example, a state in which a layer formed of a thermoplastic resin composition (X) and a layer formed of inorganic fibers (Y) are bonded together by an adhesive or the like.

[0112] Examples include (3) a state in which the thermoplastic resin composition (X) is impregnated with the inorganic fibers (Y), preferably a mat formed of the inorganic fibers (Y) (hereinafter sometimes referred to as "inorganic fiber mat"), and the thermoplastic resin composition (X) is present in the gaps of the mesh structure formed by the inorganic fibers. Here, the degree of impregnation of the thermoplastic resin composition (X) may be a state in which the inorganic fiber mat is impregnated in its entirety or in a portion thereof.

[0113] The method (4) may be a method of producing a laminate by laminating an inorganic fiber (Y), preferably an inorganic fiber mat, and a resin sheet formed of a thermoplastic resin composition (X), and hot pressing the laminate, so that at least a portion of the thermoplastic resin sheet is melt-impregnated into the inorganic fiber mat, and the thermoplastic resin sheet and the inorganic fiber mat are fused. Here, the thermoplastic resin sheet may be completely melt-impregnated into the inorganic fiber mat, or may be partially melt-impregnated into the thermoplastic resin composition on one side of the thermoplastic resin sheet in contact with the inorganic fiber mat, and the thermoplastic resin sheet may remain on the surface.

[0114] As described above, the laminate of the present invention has: layer (A), and layer (B) having a higher thermal conductivity in the thickness direction than layer (A). For the laminate of the present invention having such a layer structure, the thermal conductivity measured in the thickness direction of the laminate is preferably 0.32W / mK or more. Generally speaking, it is generally believed that the thermal conductivity of materials requiring flame shielding and heat insulation is as small as possible. However, the inventors of the present invention have conceived the following mechanism: by intentionally making the thermal conductivity in the thickness direction of the laminate larger than usual, the heat provided by contacting the flame can be efficiently transported to the opposite side of the flame contact surface, and the temperature rise on the back side of the flame contact surface can be suppressed by heat dissipation. From this viewpoint, if the thermal conductivity is 0.32W / mK or more, for example, when the laminate contacts the flame, the heat can be dissipated to the back side, which can slow down the rate of temperature rise. From the above viewpoints, the thermal conductivity measured in the thickness direction of the laminate of the present invention is more preferably 0.35W / mK or more, and further preferably 0.36W / mK or more.

[0115] The upper limit of the thermal conductivity of the laminate of the present invention is not particularly limited as long as it is within the range in which the effect of the present invention is exerted. For example, the thermal conductivity is preferably 0.70 W / mK or less. When the thermal conductivity is 0.70 W / mK or less, molding becomes easy. From the above viewpoints, the thermal conductivity is more preferably 0.60 W / mK or less, and further preferably 0.50 W / mK or less.

[0116] The laminate of the present invention can efficiently dissipate the heat of layer (A) and can suppress the temperature rise on the back side of layer (A). From the above viewpoints, the difference in thermal conductivity between layer (A) and layer (B) is preferably 10 W / mK or more, more preferably 20 W / mK or more, and further preferably 50 W / mK or more. The difference in thermal conductivity between the above-mentioned layer (A) and layer (B) has no upper limit and is usually 300 W / mK or less.

[0117] The thermal conductivity of layer (A) in the thickness direction is preferably 0.20 W / mK to 0.31 W / mK, and preferably 0.25 W / mK to 0.31 W / mK. The thermal conductivity of layer (B) in the thickness direction is preferably 10 W / mK to 400 m / mK, and preferably 50 W / mK to 250 W / mK.

[0118] It should be noted that the back surface here refers to the surface on the opposite side to the flame contact surface.

[0119] <Stamping Sheet>

[0120] When manufacturing the laminate of the present invention, as a method for forming a layer (A) in which a thermoplastic resin composition (X) and an inorganic fiber (Y) are integrated, a punchable sheet can be used. The punchable sheet uses a sheet comprising a thermoplastic resin composition (X) and an inorganic fiber (Y), and integrating the thermoplastic resin composition (X) and the inorganic fiber (Y). Regarding integration, as mentioned above, it means that the thermoplastic resin composition (X) and the inorganic fiber (Y) form a structure, and the same is true for the punchable sheet. As an integration method, the above-mentioned methods (1) to (4) can be exemplified, and as a method for manufacturing a punchable sheet, the above-mentioned (4) can be appropriately cited. The method for manufacturing a punchable sheet will be described in detail later.

[0121] [Thermoplastic resin composition (X)]

[0122] The thermoplastic resin (hereinafter referred to as thermoplastic resin (a)) constituting the thermoplastic resin composition (X) of the present invention will be described in detail below.

[0123] <Thermoplastic resin (a)>

[0124] Thermoplastic resin (a) is not particularly limited, and polyolefin resin, polycarbonate resin, polyester resin, acrylonitrile styrene resin, ABS resin, polyamide resin, modified polyphenylene ether, etc. can be cited. Among them, polyolefin resin is preferred in the present invention. It should be noted that they can be used alone or in combination. For example, thermoplastic resin (a) can be a composite resin of two or more thermoplastic resins among the above.

[0125] The polyolefin resin is not particularly limited, and the resins described below can be cited. The polyester resin is not particularly limited, and an example thereof is polybutylene terephthalate. The polyamide resin is not particularly limited, and an example thereof is nylon 66 and nylon 6.

[0126] The present invention is particularly useful when at least a polyolefin resin is included as the thermoplastic resin (a). It should be noted that in the present invention, "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 constituent units constituting the resin.

[0127] The proportion of the olefin unit or the cycloolefin unit relative to 100 mol % of all the structural units constituting the polyolefin resin is preferably 95 mol % or more, particularly preferably 98 mol % or more.

[0128] Examples of polyolefin resins include polyethylene, polypropylene, polybutene, poly(3-methyl-1-butene), poly(3-methyl-1-pentene), poly(4-methyl-1-pentene) and other α-olefin polymers; ethylene-propylene block or random copolymers, α-olefin-propylene block or random copolymers having 4 or more carbon atoms, ethylene-methyl methacrylate copolymers, ethylene-vinyl acetate copolymers and other α-olefin copolymers; polycyclohexene, polycyclopentene and other cycloolefin polymers. 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. Examples of α-olefins having 4 or more carbon atoms in α-olefin-propylene block or random copolymers 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.

[0129] Among the above-mentioned olefin resins, polypropylene-based resins (hereinafter sometimes referred to as “PP resins”) are particularly preferred.

[0130] (Melt Flow Rate (MFR))

[0131] The melt flow rate (hereinafter sometimes referred to 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 minutes. When the MFR is 40 g / 10 minutes or more, no defects will occur during the stamping of the punchable sheet, and the processability will not be reduced. In addition, when it is 500 g / 10 minutes or less, no burrs will be generated during the manufacture of the punchable sheet. From the above viewpoints, the MFR is preferably 50 to 400 g / 10 minutes, more preferably 60 to 400 g / 10 minutes, and more preferably 70 to 300 g / 10 minutes.

[0132] The MFR of the thermoplastic resin (a) can be adjusted by, for example, controlling the hydrogen concentration during polymerization.

[0133] In addition, MFR is a value measured according to JIS K7210.

[0134] (Content of Thermoplastic Resin (a))

[0135] The content of the thermoplastic resin (a) in the layer (A) of the laminate of the present invention is not particularly limited, and is preferably 15 to 80% by mass. When the content of the thermoplastic resin is 15% by mass or more, the molding processability becomes particularly good. On the other hand, when it is 80% by mass or less, a flame retardant, a dispersant and an inorganic fiber can be contained in sufficient amounts to obtain good flame shielding properties. From the above viewpoints, the content of the thermoplastic resin in the layer (A) is preferably 35 to 70% by mass, more preferably 40 to 60% by mass.

[0136] <Polypropylene resin (a-1)>

[0137] The thermoplastic resin (a) used as the layer (A) of the laminate of the present invention preferably comprises a polypropylene resin. Examples of the polypropylene resin include propylene homopolymers and propylene-α-olefin copolymers. The propylene-α-olefin copolymer may be any of a random copolymer and a block copolymer.

[0138] (α-Olefins)

[0139] As the α-olefin constituting the above-mentioned copolymer, for example, ethylene, 1-butene, 2-methyl-1-propylene, 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, 1-octene, etc. can be mentioned. These can be copolymerized with propylene using one kind, and in addition, two or more kinds can be copolymerized with propylene. Among them, from the viewpoint of improving the impact resistance of layer (A), ethylene or 1-butene having a large effect is preferred, and ethylene is most preferred.

[0140] (Propylene-ethylene random copolymer)

[0141] In the case of a random copolymer of propylene and ethylene, it is preferably 90 to 99.5 mass %, more preferably 92 to 99 mass %, of propylene units, and it is preferably 0.5 to 10 mass %, more preferably 1 to 8 mass % of ethylene units. When the ethylene units are above the above lower limit, sufficient impact strength of layer (A) can be obtained, and when it is below the above upper limit, sufficient rigidity can be maintained.

[0142] 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 to ethylene during the polymerization of the random copolymer of propylene and ethylene.

[0143] The propylene content of the random copolymer of propylene and ethylene is a value measured using a cross-classifier, FT-IR or the like, and the measurement conditions and the like may be determined by the method described in, for example, JP-A-2008-189893.

[0144] (Melt Flow Rate (MFR))

[0145] The melt flow rate (hereinafter sometimes referred to as 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 minutes. When the MFR is 40 g / 10 minutes or more, no defects will occur during the stamping of the punchable sheet for forming layer (A), and the processability will not be reduced. In addition, when it is 500 g / 10 minutes or less, no burrs will be generated in the manufacture of the punchable sheet for forming layer (A). From the above viewpoints, the MFR is preferably 50 to 400 g / 10 minutes, more preferably 60 to 400 g / 10 minutes, and more preferably 70 to 300 g / 10 minutes.

[0146] The MFR of the (A-1) polypropylene-based resin (propylene homopolymer) can be adjusted by controlling the hydrogen concentration during polymerization.

[0147] In addition, MFR is a value measured according to JIS K7210.

[0148] (Content of polypropylene resin (a-1))

[0149] The content of the polypropylene resin (a-1) in the layer (A) of the laminate of the present invention is not particularly limited, and is preferably 15 to 80% by mass. When the content of the polypropylene resin is 15% by mass or more, the molding processability becomes sufficient, and the molding of the punchable sheet for forming the layer (A) becomes easy. On the other hand, when it is 80% by mass or less, the content of the flame retardant, the dispersant and the inorganic fiber becomes sufficient, and sufficient flame shielding properties can be obtained. From the above viewpoints, the content of the polypropylene resin in the layer (A) is more preferably 35 to 70% by mass, and further preferably 40 to 60% by mass.

[0150] <Modified polyolefin resin>

[0151] The layer (A) of the present invention may contain a modified polyolefin resin in addition to the above-mentioned polypropylene resin. Specific examples of the modified polyolefin resin include acid-modified polyolefin resins and hydroxy-modified polyolefin resins, which may be used alone or in combination.

[0152] It should be noted that the types of the acid-modified polyolefin-based resin and the hydroxy-modified polyolefin-based resin used as the modified polyolefin-based resin are not particularly limited, and any conventionally known modified polyolefin-based resin may be used.

[0153] (Acid-modified polyolefin resin)

[0154] Examples of acid-modified polyolefin resins include resins obtained by graft copolymerizing and chemically modifying polyolefins such as polyethylene, polypropylene, ethylene-α-olefin copolymers, ethylene-α-olefin-non-conjugated diene compound copolymers (EPDM, etc.), and ethylene-aromatic monovinyl compound-conjugated diene compound copolymer elastomers using unsaturated carboxylic acids such as maleic acid or maleic anhydride.

[0155] The graft copolymerization can be carried out by reacting the polyolefin with an unsaturated carboxylic acid in a suitable solvent using a free radical generator such as benzoyl peroxide. In addition, 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.

[0156] Examples of the unsaturated carboxylic acid used for modification include compounds having a polymerizable double bond into which a carboxyl group and, if necessary, a hydroxyl group, an amino group or the like are introduced, such as maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid.

[0157] Derivatives of unsaturated carboxylic acids include 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. Among them, maleic anhydride is preferred.

[0158] Preferred acid-modified polyolefin resins include resins modified by grafting maleic anhydride with an olefin polymer having ethylene and / or propylene as main polymer constituent units, resins modified by copolymerizing an olefin having ethylene and / or propylene as main components with maleic anhydride, etc. Specifically, combinations of polyethylene / maleic anhydride grafted ethylene-butene-1 copolymers, or combinations of polypropylene / maleic anhydride grafted polypropylene, etc. may be mentioned.

[0159] (Hydroxy-modified polyolefin resin)

[0160] The hydroxy-modified polyolefin resin is a modified polyolefin resin containing a hydroxy group. The hydroxy-modified polyolefin resin may have a hydroxy group at an appropriate position, for example, at the terminal of the main chain or at a side chain.

[0161] Examples of the olefin resin constituting the hydroxy-modified polyolefin resin include single products or copolymers of α-olefins such as ethylene, propylene, butene, 4-methylpentene-1, hexene, octene, nonene, decene, and dodecene, and copolymers of the above α-olefins and copolymerizable monomers.

[0162] Preferred hydroxy-modified polyolefin resins include, for example, low-density, medium-density or high-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene, ethylene-(methyl)acrylate copolymers, ethylene-vinyl acetate copolymers and other hydroxy-modified polyethylene resins, polypropylene homopolymers such as isotactic polypropylene, random copolymers of propylene and α-olefins (such as ethylene, butene, hexane, etc.), propylene-α-olefin block copolymers, and hydroxy-modified polypropylene resins such as hydroxy-modified poly(4-methylpentene-1).

[0163] <Thermal expansion flame retardant (b1)>

[0164] The layer (A) of the laminate of the present invention is characterized in that the thermoplastic resin composition (X) contains a heat-expandable flame retardant (b1).

[0165] The heat-expandable flame retardant is a flame retardant that suppresses the combustion of materials by forming a surface expansion layer (intumescent) that prevents the diffusion of radiant heat from a combustion source, combustion gas, smoke, etc. from the combustion product to the outside.

[0166] Among the heat-expandable flame retardants, phosphorus-based flame retardants are preferred, and examples thereof include salts of (poly)phosphoric acid and nitrogen compounds, and specifically, ammonium salts and amine salts of (poly)phosphoric acid such as ammonium polyphosphate, melamine polyphosphate, piperazine polyphosphate, ammonium pyrophosphate, melamine pyrophosphate, and piperazine pyrophosphate.

[0167] Among them, compounds having a melamine structure or a piperazine structure are particularly preferred.

[0168] In addition, examples of nitrogen compounds include ammonia, melamine, piperazine, and other nitrogen compounds. Examples of other nitrogen compounds include 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, 1,2-propanediol, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-diethylethylenediamine, 1,2-propanediol, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-diethylethylenediamine, 1,2-propanediol, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-diethylethylenediamine, 1,2-propanediol, N,N'-dimethylethylenediamine, N ... diamine, 1,3-propylenediamine, 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, acrylic guanamine, 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-6-mercapto-1,3 ,5-triazine, 2-amino-4,6-dimercapto-1,3,5-triazine, cyanuric acid diamide, benzoguanamine, acetoguanamine, o-phthaloguanamine, melamine isocyanurate, butylene diguanamine, norbornene diguanamine, methylene diguanamine, ethylene dimelamine, trimethylene dimelamine, tetramethylene dimelamine, hexamethylene dimelamine, 1,3-hexamethylene dimelamine, etc.

[0169] As heat-expandable flame retardants other than the above, expandable graphite can be mentioned.

[0170] As the content of expandable graphite in the thermoplastic resin composition (X), it is preferably 1 to 20% by mass. When the content of graphite is 1% by mass or more, the thermal conductivity of layer (A) can be improved. In addition, when the content of graphite is 20% by mass or less, the graphite can be suppressed from falling off the stampable sheet for forming layer (A). From the above viewpoints, the content of graphite is more preferably 3 to 10% by mass.

[0171] (Content of heat-expandable flame retardant (b1))

[0172] The content of the heat-expandable flame retardant (b1) in the layer (A) of the present invention is not particularly limited, and as the content in the thermoplastic resin composition (X), it is preferably in the range of 1 to 30% by mass. When it is 1% by mass or more, it is possible to impart good flame retardancy to the layer (A) and obtain good flame shielding properties. On the other hand, when the flame retardant is 30% by mass or less, it is possible to contain the thermoplastic resin with a sufficient content ratio, so that the molding processability becomes better. From the above viewpoints, the content of the flame retardant in the thermoplastic resin composition (X) is more preferably in the range of 1 to 25% by mass, and further preferably in the range of 3 to 20% by mass.

[0173] <Flame retardant or flame retardant auxiliary (b2)>

[0174] Preferably, in layer (A) of the laminate of the present invention, the thermoplastic resin composition (X) contains, in addition to the above-mentioned heat-expandable flame retardant (b1), a flame retardant or flame retardant aid (b2) different from the heat-expandable flame retardant (b1), and the decomposition temperature of the flame retardant or flame retardant aid (b2) is higher than the thermal expansion starting temperature of the heat-expandable flame retardant (b1) by at least 10°C.

[0175] By making the decomposition temperature of the flame retardant or flame retardant auxiliary (b2) higher than the thermal expansion starting temperature of the heat-expandable flame retardant (b1) by more than 10°C, even if the temperature further rises after the thermal expansion of the heat-expandable flame retardant (b1) starts to exert flame shielding and heat insulation effects, the flame retardant or flame retardant auxiliary (b2) can still exert its effect, thereby being able to suppress further combustion.

[0176] From the above viewpoints, the decomposition temperature of the flame retardant or flame retardant auxiliary (b2) is more preferably 20°C or more higher than the thermal expansion starting temperature of the flame retardant (b1), and further preferably 30°C or more higher.

[0177] It should be noted that the flame retardant or flame retardant auxiliary (b2) is not particularly limited as long as it is different from the heat-expandable flame retardant (b1) and has a decomposition temperature that is 10°C or higher than the thermal expansion starting temperature of the heat-expandable flame retardant (b1). Among them, the non-heat-expandable flame retardant or non-heat-expandable flame retardant auxiliary (b2') described later is preferred.

[0178] <Non-thermal expansion flame retardant or non-thermal expansion flame retardant auxiliary (b2')>

[0179] It is preferred that the thermoplastic resin composition (X) of the present invention further contains a non-thermally expandable flame retardant or a non-thermally expandable flame retardant auxiliary (b2') in addition to the above-mentioned heat-expandable flame retardant (b1).

[0180] Preferred examples of the non-heat-expandable flame retardant or non-heat-expandable flame retardant aid (b2') include metal hydroxides and polytetrafluoroethylene, which may be used alone or in combination of two or more.

[0181] (Metal Hydroxide)

[0182] The metal hydroxide is not particularly limited as long as it can absorb thermal energy by decomposing hydroxyl groups, and specifically, inorganic metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide are preferred. One or more metal hydroxides may be used.

[0183] Among the inorganic metal hydroxides, trivalent metal hydroxides and alkaline earth metal hydroxides, particularly magnesium hydroxide (decomposition temperature 350° C.), aluminum hydroxide (decomposition temperature 200° C.), and calcium hydroxide (decomposition temperature 580° C.) are suitable. Among them, magnesium hydroxide is preferred because it is excellent in obtaining the effects of the present invention.

[0184] The average particle size of the metal hydroxide is not particularly limited, but is generally 0.1 to 15 μm, preferably 0.2 to 10 μm, more preferably 0.3 to 5 μm, and particularly preferably 0.5 to 2 μm. When the particle size of the metal hydroxide is within the above range, the dispersibility of the metal hydroxide in the thermoplastic resin composition (X) is improved, and flame retardancy is more easily exhibited.

[0185] The content of the metal hydroxide in the thermoplastic resin composition (X) is preferably in the range of 10 to 60% by mass, and more preferably in the range of 15 to 40% by mass. When it is above the lower limit, the flame retardant effect of the metal hydroxide can be fully exerted. On the other hand, when it is below the upper limit, metal agglomeration does not occur, so it is preferred.

[0186] (Polytetrafluoroethylene)

[0187] Polytetrafluoroethylene is a fluorine-based anti-drip agent having the function of an anti-drip agent, and the function as an anti-drip agent is to improve the drip resistance and flame retardancy of the layer (A) in the laminate of the present invention when it burns.

[0188] Polytetrafluoroethylene can be obtained by emulsion polymerization of tetrafluoroethylene monomer using fluorinated surfactant. It should be noted that, during emulsion polymerization, fluorinated olefins such as hexafluoropropylene, chlorotrifluoroethylene, fluoroalkylethylene and perfluoroalkyl vinyl ether and (meth) acrylic acid fluorinated alkyl esters such as perfluoroalkyl esters of (meth) acrylic acid can be used as copolymerization components within the scope of not damaging the characteristics of polytetrafluoroethylene. Other monomers copolymerized with tetrafluoroethylene can be used within the scope of not damaging the characteristics of polytetrafluoroethylene, and are preferably less than 10% by mass in 100% by mass of polytetrafluoroethylene.

[0189] The weight average molecular weight (Mw) of polytetrafluoroethylene is preferably 1,000,000 to 50,000,000, more preferably 3,000,000 to 30,000,000. When Mw is more than 1,000,000, the drip resistance is improved when the laminate of the present invention burns, and the flame retardancy becomes good. On the other hand, when Mw is less than 50,000,000, the dispersibility of polytetrafluoroethylene is excellent, and the processability of the laminate can be maintained.

[0190] It should be noted that the decomposition temperature of polytetrafluoroethylene depends on the weight average molecular weight, and is approximately 500 to 600° C. when the Mw is within the above range.

[0191] The content of polytetrafluoroethylene in the thermoplastic resin composition (X) is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and further preferably 0.1 to 3% by mass. By setting the polytetrafluoroethylene content to 0.01% by mass or more, drip resistance during combustion can be imparted. In addition, by setting it to 10% by mass or less, the processability of the laminate is maintained.

[0192] <Other flame retardants>

[0193] As described above, the thermoplastic resin composition (X) of the present invention preferably contains a heat-expandable flame retardant (b1), a flame retardant (b2) having a decomposition temperature that is 10° C. or higher, preferably 20° C. or higher, than the thermal expansion starting temperature of the heat-expandable flame retardant (b1), and a non-heat-expandable flame retardant (b2′), but may also contain flame retardants other than these flame retardants.

[0194] There are no particular limitations on other flame retardants, and any flame retardant that has been used conventionally can be used.

[0195] Specific examples include phosphorus-based flame retardants other than the above-mentioned heat-expandable flame retardant (b1), bromine-based flame retardants, antimony-based flame retardants, etc. Among them, phosphorus-based flame retardants are preferred from the viewpoint of improving flame barrier properties.

[0196] (Phosphorus flame retardant)

[0197] The phosphorus-based flame retardant is a phosphorus compound, that is, a compound containing a phosphorus atom in a molecule. The phosphorus-based flame retardant forms a char when the resin composition is burned, thereby exhibiting a flame retardant effect.

[0198] The phosphorus flame retardant may be a known phosphorus flame retardant, for example, (poly)phosphate, (poly)phosphate ester, etc. Here, "(poly)phosphate" means a phosphate or a polyphosphate, and "(poly)phosphate ester" means a phosphate ester or a polyphosphate ester.

[0199] It should be noted that the phosphorus-based flame retardant is preferably solid at 80°C.

[0200] As the phosphorus-based flame retardant, (poly)phosphate is preferred from the viewpoint of flame retardancy.

[0201] Examples of the (poly)phosphate include ammonium polyphosphate salts, melamine polyphosphate salts, piperazine polyphosphate salts, piperazine orthophosphate salts, melamine pyrophosphate salts, piperazine pyrophosphate salts, melamine polyphosphate salts, melamine orthophosphate salts, calcium phosphate, and magnesium phosphate.

[0202] In the above examples, compounds obtained by replacing melamine or piperazine with other nitrogen compounds can also be used in the same manner. These (poly)phosphates may be used alone or in combination of two or more.

[0203] Examples of commercially available phosphorus flame retardants include ADK STAB FP-2100J, FP-2200, and FP-2500S (manufactured by ADEKA Corporation).

[0204] (Brominated flame retardants)

[0205] Examples of the bromine-based flame retardant 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, brominated polystyrene, ethylenebistetrabromophthalimide, 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.

[0206] (Antimony flame retardant)

[0207] Examples of the antimony flame retardant include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium pyroantimonate, antimony trichloride, antimony trisulfide, antimony oxychloride, antimony dichloride perchloropentane, and potassium antimonate. Antimony trioxide and antimony pentoxide are particularly preferred.

[0208] Among the flame retardants, phosphorus flame retardants are preferred from the perspective of no bioresidue and excellent flame retardancy, and halogen-free flame retardants are preferred from the perspective of environmental protection. In addition, intumescent flame retardants are preferred from the perspective of improving the flame shielding properties of the punchable sheet obtained.

[0209] In addition, the above flame retardants may be used alone or in combination of two or more.

[0210] (Metal Oxide)

[0211] The thermoplastic resin composition (X) of the present invention preferably contains a metal oxide. The metal oxide has a function as a flame retardant aid. Specifically, cadmium oxide, zinc oxide, cuprous oxide, cupric oxide, ferrous oxide, ferric oxide, cobalt oxide, manganese oxide, molybdenum oxide, tin oxide and titanium oxide can be cited, among which zinc oxide is particularly preferred because of its good effect.

[0212] The content of the metal oxide is preferably in the range of 0.01 to 20 parts by mass, more preferably in the range of 0.5 to 10 parts by mass, and further preferably in the range of 1 to 5 parts by mass, relative to 100 parts by mass of the flame retardant containing the above-mentioned heat-expandable flame retardant (b1). When it is in the above range, the effect as a flame retardant auxiliary can be fully exerted.

[0213] <Copolymer of α-olefin and unsaturated carboxylic acid>

[0214] It is preferred that the thermoplastic resin composition (X) of the present invention further contains a copolymer of an α-olefin and an unsaturated carboxylic acid.

[0215] By using the copolymer, the dispersibility of the flame retardant including the heat-expandable flame retardant (b1) can be improved, and the content of the heat-expandable flame retardant and the like can be reduced.

[0216] The ratio of the α-olefin unit in the total of 100 mol % of the α-olefin unit and the unsaturated carboxylic acid unit in the "copolymer of α-olefin and unsaturated carboxylic acid" (hereinafter referred to as "copolymer (c1)") of the present invention is preferably 20 mol % to 80 mol %.

[0217] In the copolymer (c1), the ratio of the α-olefin unit to the total amount of the α-olefin unit and the unsaturated carboxylic acid unit is more preferably 30 mol% or more, and on the other hand, it is more preferably 70 mol% or less. When the ratio of the α-olefin is above the above lower limit, the compatibility with the thermoplastic resin (a) such as the polyolefin resin becomes better, and when it is below the above upper limit, the compatibility with the heat-expandable flame retardant (b1) becomes better.

[0218] 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 or more and 80 or less carbon atoms. When the carbon number of the α-olefin is 5 or more, there is a tendency for the compatibility with the thermoplastic resin (a) to become better, and when it is 80 or less, it is advantageous from the perspective of raw material cost. From the above viewpoints, the carbon number of the α-olefin is more preferably 12 or more and 70 or less, and particularly preferably 18 or more and 60 or less.

[0219] In the copolymer (c1), unsaturated carboxylic acids include, for example, (meth)acrylic acid, maleic acid, methylmaleic acid, fumaric acid, methylfumaric acid, tetrahydrophthalic acid, itaconic acid, crotonic acid, isocrotonic acid, glutaconic acid, norbornyl-5-ene-2,3-dicarboxylic acid, and esters, anhydrides, and imides of these unsaturated carboxylic acids. It should be noted that "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0220] Specific examples of esters, anhydrides or imides of unsaturated carboxylic acids include (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and glycidyl (meth)acrylate; dicarboxylic anhydrides such as maleic anhydride, itaconic anhydride, citraconic anhydride, and 5-norbornene-2,3-dicarboxylic anhydride; maleimide compounds such as maleimide, N-ethylmaleimide, and N-phenylmaleimide, etc. These may be used alone or in combination of two or more.

[0221] Among the above, esters and dicarboxylic anhydrides are preferred from the viewpoint of copolymerization reactivity. Among them, dicarboxylic anhydrides are preferred from the viewpoint of compatibility with phosphorus-based flame retardants suitable as flame retardants, and maleic anhydride is particularly preferred.

[0222] The weight average molecular weight of the copolymer (c1) is preferably 2000 or more, more preferably 3000 or more, and is preferably 50000 or less, more preferably 30000 or less. When the weight average molecular weight of the copolymer (c1) is within the above range, the dispersibility of the heat expandable flame retardant (b1) becomes more excellent.

[0223] The weight average molecular weight of the copolymer (c1) is a value calculated in terms of standard polystyrene obtained by dissolving the copolymer (c1) in tetrahydrofuran (THF) and measuring the result by gel permeation chromatography.

[0224] Examples of commercially available products of the copolymer (c1) include Licolub CE2 (manufactured by CLARIANT JAPAN) and DIACARNA 30M (manufactured by Mitsubishi Chemical Corporation).

[0225] The content of the copolymer (c1) in the laminate of the present invention is greater than 0 and 25 parts by mass or less, preferably 0.01 to 10 parts by mass, based on 100 parts by mass of the flame retardant including the heat-expandable flame retardant (b1).

[0226] According to the research of the present inventors, the flame shielding property of layer (A) can be significantly improved by using thermoplastic resin as matrix resin and uniformly dispersing flame retardant and present in inorganic fibers (Y) constituting layer (A). The detailed mechanism is not clear, but the present inventors speculate as follows. That is, in the case where the flame retardant is uniformly dispersed in the resin between inorganic fibers, the char formed by the contact of the phosphorus flame retardant with the flame is fixed in the gap between the inorganic fibers. Furthermore, the size of the char formed by the expansion when contacting the flame is limited by the gap between the inorganic fibers, thereby, the size of the char formed becomes uniform. It can be considered that by combining the fixing effect of the char based on inorganic fibers with the homogenization of the size of the char, a dense char can be formed, which significantly improves the flame shielding property of layer (A). Based on these insights, the present inventors found that by setting the ratio of the content of the dispersant to the flame retardant to a specific range, it is possible to control the flame retardant to be uniformly present in the resin between the inorganic fibers, which can significantly improve the flame shielding property of layer (A).

[0227] Based on the above reasons, when the content of (c1) copolymer is greater than 0, the dispersibility of the heat-expandable flame retardant (b1) becomes sufficient, and sufficient flame shielding properties can be given to layer (A). On the other hand, when it is less than 25 parts by mass, the physical properties of layer (A) become sufficient. From the same point of view, the content of (c1) copolymer is preferably more than 0.01 parts by mass, more preferably more than 0.1 parts by mass, further preferably more than 1 part by mass, and particularly preferably more than 2 parts by mass. On the other hand, about the upper limit value, it is more preferably less than 20 parts by mass, more preferably less than 15 parts by mass, further more preferably less than 10 parts by mass, further more preferably less than 5 parts by mass, and particularly preferably less than 3 parts by mass.

[0228] In addition, the ratio of (c1) copolymer to the total of 100 parts by mass of the flame retardant containing the (a) thermoplastic resin and the heat-expandable flame retardant (b1) is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and further 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, further preferably 2.0 parts by mass or less, further preferably 1.5 parts by mass or less, and further preferably 1.0 parts by mass or less. When the ratio of (c1) copolymer is above the above lower limit, the heat-expandable flame retardant (b1) is more well dispersed, and the flame shielding property, physical properties, and appearance of the obtained molded body of the obtained laminate become better. When the ratio of (c1) copolymer is below the above upper limit, the influence of the (c1) copolymer on the flame shielding property of layer (A) can be further suppressed. In particular, the ratio of the copolymer (c1) to the total of 100 parts by mass of the polyolefin resin and the flame retardant including the heat-expandable flame retardant (b1) is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and further 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, further preferably 2.0 parts by mass or less, further preferably 1.5 parts by mass or less, and further preferably 1.0 parts by mass or less.

[0229] In addition, for the (Y) inorganic fiber described in detail below, the ratio of the (c1) copolymer to 100 parts by mass of the (Y) inorganic fiber is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and further 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 further preferably 2.0 parts by mass or less. When the ratio of the (c1) copolymer is above the above lower limit, the flame shielding properties, physical properties of the obtained laminate, and the appearance of the obtained molded body become better. When the ratio of the (c1) copolymer is below the above upper limit, the influence of the (c1) copolymer on the flame shielding properties of the laminate can be further suppressed.

[0230] <(Y) Inorganic fiber>

[0231] The layer (A) of the present invention contains (Y) inorganic fibers. As the (Y) inorganic fibers, various fibers can be used, for example: glass fibers, rock wool, alumina fibers, metal oxide fibers such as silica alumina fibers, potassium titanate fibers, calcium silicate (wollastonite) fibers, ceramic fibers such as ceramic fibers, carbon fibers, metal fibers, etc. These inorganic fibers can be used alone or in combination of two or more.

[0232] Among the above-mentioned inorganic fibers, from the viewpoint of flame shielding properties and processability, at least one selected from glass fibers and alumina fibers is preferred, and glass fibers are particularly preferred.

[0233] As (Y) inorganic fiber, two or more inorganic fibers having different melting temperatures may be included. As a combination of two or more inorganic fibers having different melting temperatures, it is preferred that at least one of the inorganic fibers is glass fiber and the other one or more inorganic fibers are selected from alumina fiber, silica fiber, alkaline earth silicate fiber (biosoluble) and carbon fiber. By including two or more inorganic fibers having different melting temperatures, it is possible to effectively prevent the flame shielding function from being reduced.

[0234] In addition, the inorganic fibers used in the present invention may be used in combination with a sizing agent or a surface treatment agent. Examples of such sizing agents or surface treatment agents include compounds having functional groups such as epoxy compounds, silane compounds, and titanate compounds.

[0235] The average fiber diameter of the inorganic fibers is preferably 3 to 25 μm, and the average fiber length is preferably 0.1 mm or more, more preferably 1 mm or more, and even more preferably 5 mm or more.

[0236] It should be noted that the suitable ranges of the average fiber diameter and the average fiber length vary depending on the type of inorganic material constituting the inorganic fibers, and the specific suitable ranges will be described later.

[0237] In addition, the fiber diameter can be measured using a scanning electron microscope, etc., and the average fiber diameter can be obtained by, for example, randomly measuring the fiber diameters of 10 fibers and calculating the average value. In addition, the fiber length can be measured using a ruler, a vernier caliper, etc. from an image magnified by a microscope as needed, and the average fiber length can be obtained by, for example, randomly measuring the fiber lengths of 10 fibers and calculating the average value.

[0238] In addition, since the suitable ranges of the average fiber diameter and the average fiber length differ depending on the type of inorganic material constituting the inorganic fiber, the specific suitable ranges will be described later.

[0239] The content of inorganic fiber in layer (A) of the present invention is 1~80 mass %. When the content of inorganic fiber is less than 1 mass %, the strength, rigidity and impact resistance of the punchable sheet are sometimes reduced. If it is greater than 80 mass %, there is a hidden danger that the manufacture and processing of the punchable sheet become obviously difficult. In addition, if the content of inorganic fiber is greater than 80 mass %, the specific gravity of the laminate becomes heavier, and therefore, the lightweight effect as a metal substitute becomes smaller, and is therefore not preferred.

[0240] From the above viewpoints, the content of the (D) inorganic fibers in the layer (A) is more preferably 3 to 60% by mass, further preferably 10 to 50% by mass, and particularly preferably 30 to 45% by mass.

[0241] (Fiberglass)

[0242] As one of the (Y) inorganic fibers suitable for the punchable sheet of the present invention, glass fibers can be cited. As glass fibers, for example, long fibers with an average fiber length of more than 30 mm can be used, or fibers with a short average fiber length (chopped strands) can be used. From the viewpoints of flame shielding, rigidity, impact resistance, etc., glass fibers with a long average fiber length are preferably used.

[0243] More specifically, as the average fiber length, it is preferably 5 mm or more. When the average fiber length is 5 mm or more, the strength and impact resistance of the punchable sheet become good. From the above viewpoints, the average fiber length of the glass fiber is preferably 5 mm or more, more preferably 30 mm or more.

[0244] It should be noted that there is no particular upper limit on the average fiber length of the glass fiber. For example, in the case of particles produced by using glass fibers through pultrusion, the length of the particles becomes the fiber length of the glass fibers, so the maximum is about 20 mm. In addition, in swirl mats using long glass fibers, the length of the glass fibers in the roving used for production becomes the maximum fiber length, so it will reach about 17,000 m (17 km), but when cut according to the size of the punchable sheet, the length after cutting becomes the maximum fiber length.

[0245] In addition, the average fiber diameter of the glass fiber 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 laminate become sufficient, and on the other hand, when the average fiber diameter is 25 μm or less, the strength of the punchable sheet becomes good. From the above viewpoints, the average fiber diameter of the glass fiber is more preferably in the range of 10 to 15 μm.

[0246] In addition, the average fiber diameter and the average fiber length of the glass fiber can be measured by the above-mentioned method.

[0247] The material of the glass fiber used in the present invention is not particularly limited, and may be any of alkali-free glass, low-alkali glass, and alkali-containing glass, and materials of various compositions conventionally used as glass fibers may be used.

[0248] (Alumina Fiber)

[0249] As one of the (D) inorganic fibers suitable for the laminate of the present invention, alumina fibers can be cited. Alumina fibers are generally fibers formed of alumina and silica, and in the punchable sheet of the present invention, the composition ratio (mass ratio) of alumina / silica of the alumina fibers 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.

[0250] The average fiber diameter of the alumina fibers is preferably in the range of 3 to 25 μm, and preferably substantially no fibers with a fiber diameter of 3 μm or less are included. Here, substantially no fibers with a fiber diameter of 3 μm or less means that fibers with a fiber diameter of 3 μm or less account for less than 0.1% by mass of the total inorganic fiber mass.

[0251] In addition, the average fiber diameter of the alumina fiber is more preferably 5 to 8 μm. If the average fiber diameter of the inorganic fiber is too thick, the resilience and toughness of the mat-shaped inorganic fiber assembly layer will decrease. On the contrary, if it is too thin, the amount of dust floating in the air will increase, and the probability of containing inorganic fibers with a fiber diameter of 3 μm or less will increase.

[0252] The alumina fibers preferably have an average fiber length of 5 mm or more, more preferably 30 mm or more, and even more preferably 50 mm or more. 3 mm or less, more preferably 1.0×10 3 When the average fiber length and average fiber diameter of the alumina fibers are within this range, the strength and impact resistance of the laminated body become good.

[0253] (Carbon Fiber)

[0254] The suitable range of carbon fiber is also the same as that of glass fiber.

[0255] <Optional Additives>

[0256] In addition to the above-mentioned components, the layer (A) of the laminate of the present invention may further contain any additional components 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.

[0257] Specifically, the colorants include 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 / antifungal agents such as thiazoles, halogen compounds, flame retardants / flame retardant aids such as lignophenol, plasticizers, dispersants such as organic metal salts, lubricants such as fatty acid amides, metal deactivators such as nitrogen compounds, thermoplastic resins such as polyolefin resins other than the above-mentioned polypropylene resins, polyamide resins, and polyester resins, and elastomers (rubber components) such as olefin elastomers and styrene elastomers.

[0258] These optional additional components may be used in combination of two or more.

[0259] Colorants such as inorganic and organic pigments are effective for imparting or improving the colored appearance, aesthetics, feel, commercial value, weather resistance, durability, etc. of the polypropylene resin composition and its molded article.

[0260] As specific examples, inorganic pigments include carbon black such as furnace carbon and ketjen carbon; titanium oxide; iron oxide (red iron, etc.); chromic acid (chrome yellow, etc.); molybdic acid; selenium sulfide; ferrocyanide, etc., and organic pigments include azo pigments such as poorly soluble azo lakes, soluble azo lakes, insoluble azo chelates; condensed azo chelates; other azo chelates; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; threne pigments such as anthraquinone, perinone, perylene, and thioindigo; dye lakes; quinacridones; diazine; Oxazine; isoindolinone, etc. In addition, in order to make a metallic style or a pearl style, aluminum flakes and pearl pigments may be contained. In addition, dyes may also be contained.

[0261] Light stabilizers and ultraviolet absorbers, such as hindered amine compounds, benzotriazoles, benzophenones, salicylates, etc., are effective in imparting and improving the weather resistance and durability of polypropylene resin compositions and their molded products, and are effective in further improving weather resistance and discoloration.

[0262] As specific examples, hindered amine compounds include condensates 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]]; 1,2,3,4-butanetetracarboxylic acid tetra(2,2,6,6-tetramethyl-4-piperidyl) ester; 1,2,3,4-butanetetracarboxylic acid tetra(1,2,2,6,6-pentamethyl-4-piperidyl) ester; decanetetracarboxylic acid tetra(1,2,2,6,6-pentamethyl-4-piperidyl) ester; Examples of the benzotriazoles include 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole. Examples of the benzophenones include 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octyloxybenzophenone. Examples of the salicylic acid esters include 4-tert-butylphenyl salicylate and 2,4-di-tert-butylphenyl 3',5'-di-tert-butyl-4'-hydroxybenzoate.

[0263] Here, a method of using the above-mentioned light stabilizer and ultraviolet absorber in combination is preferred because it has a significant effect of improving weather resistance, durability, weather resistance and discoloration.

[0264] As antioxidants, for example, phenolic, phosphorus, and sulfur antioxidants are effective for imparting or improving heat resistance stability, processing stability, heat aging resistance, and the like of polypropylene resin compositions and molded articles thereof.

[0265] In addition, as the antistatic agent, for example, nonionic, cationic or other antistatic agents are effective for imparting or improving the antistatic property of the polypropylene resin composition and its molded article.

[0266] As olefin elastomers, for example, there can be mentioned: ethylene / α-olefin copolymer elastomers such as ethylene / propylene copolymer elastomer (EPR), ethylene-butene copolymer elastomer (EBR), ethylene / hexene copolymer elastomer (EHR), ethylene / octene copolymer elastomer (EOR); ethylene / α-olefin / diene terpolymer elastomers such as ethylene / propylene / ethylidene norbornene copolymer, ethylene / propylene / butadiene copolymer, ethylene / propylene / isoprene copolymer; styrene / butadiene / styrene triblock copolymer elastomer (SBS), etc.

[0267] In addition, examples of styrene-based elastomers include styrene / isoprene / styrene triblock copolymer elastomers (SIS), styrene-ethylene / butylene copolymer elastomers (SEB), styrene-ethylene / propylene copolymer elastomers (SEP), styrene-ethylene / butylene-styrene copolymer elastomers (SEBS), styrene-ethylene / butylene-ethylene copolymer elastomers (SEBC), hydrogenated styrene / butadiene elastomers (HSBR), styrene-ethylene / propylene-styrene copolymer elastomers (SEPS), styrene-ethylene / ethylene / propylene-styrene copolymer elastomers (SEEPS), styrene-butadiene / butylene-styrene copolymer elastomers (SBBS), partially hydrogenated styrene-isoprene-styrene copolymer elastomers, partially hydrogenated styrene-isoprene / butadiene-styrene copolymer elastomers and the like, and hydrogenated polymer-based elastomers such as ethylene-ethylene / butylene-ethylene copolymer elastomers (CEBC) and the like.

[0268] Among them, when an ethylene-octene copolymer elastomer (EOR) and / or an ethylene-butene copolymer elastomer (EBR) is used, it is preferred for the polypropylene-based resin composition of the present invention and its molded article because it is easy to impart appropriate flexibility and tends to have excellent impact resistance.

[0269] <Method for producing thermoplastic resin composition (X)>

[0270] As described above, the thermoplastic resin composition (X) of the present invention contains (a) a thermoplastic resin, a modified polyolefin resin added as needed, a flame retardant including a heat-expandable flame retardant (b1), and a copolymer (c1) added as needed. In addition, any additional components may be further formulated. In the above-mentioned thermoplastic resin composition (X), when the thermoplastic resin (a) is a polypropylene resin (a-1), it is sometimes specifically referred to as a polypropylene resin composition (hereinafter sometimes described as a "PP composition").

[0271] As a method for producing the thermoplastic resin composition (X) or the PP composition, a conventionally known method can be utilized, and the composition can be produced by blending the above-mentioned components, mixing, and melt-kneading.

[0272] Mixing can be performed using a mixer such as a tumbler, a V mixer, or a ribbon mixer, and melt kneading can be performed using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll mixer, a Brabender mixer, a kneader, or the like to perform melt kneading and granulation.

[0273] <Method for producing punchable sheet>

[0274] When producing the laminate of the present invention, a punchable sheet may be used in order to form a layer (A) in which the thermoplastic resin composition (X) and the inorganic fibers (Y) are integrated.

[0275] The method for producing the punchable sheet is not particularly limited, but preferably, the sheet is produced by impregnating the thermoplastic resin composition (X) or PP composition into a mat (inorganic fiber mat) formed of (Y) inorganic fibers. As the impregnation method, there are the following methods: a method of applying the thermoplastic composition or PP composition to the inorganic fiber mat (Y); a method of pre-making a sheet of the thermoplastic resin composition or PP composition (hereinafter sometimes referred to as a "thermoplastic resin sheet" or "PP sheet"), laminating the thermoplastic resin sheet or PP sheet on the inorganic fiber mat, heating it, melting it, and impregnating it, etc.

[0276] In the present invention, from the viewpoint of impregnation of the resin of the punchable sheet into the fibers, a method of laminating a thermoplastic resin sheet or a PP sheet on an inorganic fiber mat, heating and melting the sheet is preferred. In particular, the sheet can be obtained by laminating the sheet so that the inorganic fiber mat is located between two thermoplastic resin sheets or PP sheets, then heating and pressurizing the laminate, and then cooling and solidifying the laminate.

[0277] Here, the thickness of the thermoplastic resin sheet or the PP sheet is not particularly limited as long as it is within a range that allows the fiber mat to be impregnated satisfactorily.

[0278] (Inorganic fiber mat)

[0279] The form of the inorganic fibers used in the method for producing the punchable sheet is not particularly limited, and various forms of inorganic fibers can be used. However, inorganic fibers in a mat or sheet form are preferred.

[0280] More specifically, a mat formed of glass fibers (hereinafter referred to as “glass fiber mat”) or a mat formed of metal oxide fibers represented by alumina fibers (hereinafter referred to as “metal oxide mat”) is preferred.

[0281] The weight per unit area (mass per unit area) of the inorganic fiber mat is not particularly limited and can be appropriately determined according to the intended use, but is preferably 300 g / m 2 More than 800 g / m 2 , more preferably greater than 1500g / m 2 In addition, the weight per unit area of ​​the inorganic fiber mat is not particularly limited, but is preferably 5000 g / m 2 Below, more preferably 4500g / m 2 Below, more preferably 4000g / m 2 Below, particularly preferably 3500g / m 2 the following.

[0282] By adjusting the average fiber amount per unit area when stacking the inorganic fiber aggregates constituting the inorganic fiber mat using a folding device, the average unit area weight per unit area of ​​the inorganic fiber mat (weight per unit area) can be set to the above range. In addition, the inorganic fiber mat of the present invention can be a structure formed by bonding multiple inorganic fiber mats or a single structure. From the perspective of handleability and peel strength at the bonding interface, a single structure is preferred.

[0283] (Fiberglass Mat)

[0284] As the form of the glass fiber mat used in the present invention, there can be mentioned felts and blankets obtained by processing short fiber glass wool, chopped strand mats obtained by processing continuous glass fibers, eddy current (swirl-shaped) mats of continuous glass fibers, unidirectionally drawn mats, etc. Among them, when a glass fiber mat obtained by needle-punching a eddy current (swirl-shaped) mat of continuous glass fibers is used, it is particularly preferred because the strength and impact resistance of the punched sheet are excellent.

[0285] (Metal Oxide Fiber Mat)

[0286] The metal oxide fiber mat of the present invention is a mat composed of metal oxide fibers such as alumina fibers and subjected to a needle punching treatment.

[0287] In the method of laminating a thermoplastic resin sheet or a PP sheet on an inorganic fiber mat, 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 PP composition can be fully impregnated into the inorganic fiber mat, and a suitable punchable sheet 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.

[0288] In addition, the pressurization pressure is preferably 0.1 to 1 MPa. When the pressurization pressure is 0.1 MPa or more, the thermoplastic resin composition or PP composition can be fully impregnated into the inorganic fiber mat, and a suitable punchable sheet can be obtained. On the other hand, by setting it to 1 MPa or less, the thermoplastic resin composition or PP composition flows and does not generate burrs.

[0289] In addition, the cooling temperature is not particularly limited as long as it is below the solidification point of the thermoplastic resin in the thermoplastic resin composition or the PP composition. When the cooling temperature is 80° C. or below, the obtained punchable sheet will not be deformed when taken out. From the above viewpoints, the cooling temperature is preferably room temperature to 80° C.

[0290] As methods for obtaining a punchable sheet by heating, pressurizing and cooling the above-mentioned laminate, there are the following methods: a method of press-molding the laminate in a mold with a heating device; and a lamination process in which the laminate is heated and pressurized by passing it between two pairs of rollers with a heating device. In particular, the lamination process is preferred because it can be produced continuously and therefore has good productivity.

[0291] <Thickness of stampable sheets>

[0292] The thickness of the punchable sheet that can be suitably used in the manufacture of the laminate of the present invention is usually 1 to 10 mm, preferably 2 to 5 mm. When the thickness of the punchable sheet is 1 mm or more, the manufacture of the punchable sheet is easy. On the other hand, when the thickness of the punchable sheet is 10 mm or less, when the punchable sheet is processed by punching molding, etc., long-term preheating is not required, and good molding processability can be obtained.

[0293] <Layer (B)>

[0294] The laminate of the present invention comprises a layer (B) having a higher thermal conductivity in the thickness direction than the layer (A). The layer (B) is not particularly limited as long as it has a higher thermal conductivity in the thickness direction than the layer (A), but is preferably a metal layer of a high thermal conductivity material.

[0295] <Metal layer>

[0296] The metal layer has a high thermal conductivity, and thus heat dissipation from the laminate of the present invention is easily achieved, and the temperature of the back surface of the layer (A) of the laminate can be kept low.

[0297] As the material of the metal layer, various steel materials, stainless steel materials, titanium materials, or aluminum materials (including aluminum alloys) can be cited from the aspect of thermal conductivity. As for the thickness of the metal layer, there is no particular limitation as long as it is within the range of exerting the effect of the present invention, and it is preferably in the range of 0.05 to 2.0 mm, and more preferably in the range of 0.1 to 1.0 mm.

[0298] The laminate of the present invention also preferably has an adhesive layer between the layer (A) and the layer (B), i.e., the metal layer, of the laminate. As the adhesive layer, a commercially available adhesive film or the like can be used, preferably an adhesive layer formed of a thermoplastic resin. Such an adhesive layer can be formed, for example, by placing a commercially available hot melt film or the like between the above-mentioned stampable sheet for forming the layer (A) and the metal layer and heating and pressurizing. As a method other than the above-mentioned hot melt film, a method of bonding the layer (A) and the layer (B) of the laminate via an existing well-known double-sided adhesive tape can be cited.

[0299] The thickness of the adhesive layer is not particularly limited as long as it is within the range that can exert the effects of the present invention. In the case of a hot melt film, the thickness is preferably in the range of 10 to 50 μm, more preferably in the range of 20 to 40 μm. In the case of a double-sided adhesive tape, the thickness is preferably in the range of 0.025 to 2 mm.

[0300] In addition, as a method of laminating the layer (A) and the layer (B), that is, the metal layer, of the laminate, it is not necessary to interpose an adhesive layer.

[0301] (use)

[0302] As the use of the laminate of the present invention, for example, various parts in industrial fields such as automobile parts and electrical and electronic equipment parts can be cited. In particular, since the laminate has excellent strength, rigidity, conductivity, and processability, it can be suitably used in applications that require these properties to be more highly balanced, such as various housings and frames such as battery cases.

[0303] The battery is not particularly limited, and examples thereof include secondary batteries such as lithium ion batteries, nickel / hydrogen batteries, lithium / sulfur batteries, nickel / cadmium batteries, nickel / iron batteries, nickel / zinc batteries, sodium / sulfur batteries, lead storage batteries, and air batteries. Among them, lithium ion batteries are preferred, and in particular, the punchable sheet or laminate of the present invention can be suitably used as a battery case for suppressing thermal runaway of lithium ion batteries.

[0304] Example

[0305] Hereinafter, the present invention will be described in detail using Examples, but the present invention is not limited to these Examples.

[0306] 1. Evaluation of flame shielding properties

[0307] For the sheets prepared in each example and comparative example, one surface was exposed to the flame of a burner at 1300°C, and the flame was evaluated for penetration after 15 minutes. The distance from the burner nozzle to the sample was set to 160 mm. The flame surface was set to 1200°C. The flame surface temperature was confirmed by a thermocouple thermometer.

[0308] 2. Evaluation of thermal insulation

[0309] In the flame shielding evaluation described in 1. above, the temperature of the surface (back side) opposite to the surface in contact with the flame of the burner of the test piece was measured by a non-contact radiation thermometer ("FT-H50K" manufactured by Keyence). The measurement area is φ35mm. The center of the measurement area was set by visual observation in a manner near the position directly above the flame of the burner. Table 1 shows the highest temperature (°C) reached on the back side until 600 seconds have passed.

[0310] 3. Evaluation of thermal conductivity

[0311] The thermal conductivity was measured using a steady-state thermal conductivity measuring device (GH-1 manufactured by ULVAC-RIKO) according to a method in accordance with ASTM E1530. The measurement conditions are shown below.

[0312] Measuring temperature: 30℃ (temperature difference between upper and lower parts: 24℃)

[0313] Measurement sample size: 50 mm square

[0314] Measurement direction: Thickness direction (resin side is placed on the upper surface, metal plate is placed on the lower surface)

[0315] (Materials used)

[0316] 1. Polypropylene resin (component a)

[0317] “NOVATEC PP SA06GA” (melt flow rate: 60 g / 10 minutes) manufactured by Japan Polypropylene Co., Ltd. was used.

[0318] 2. Thermal expansion flame retardant (component b1)

[0319] The phosphorus-based flame retardant composition (ADK STAB FP-2500S manufactured by ADEKA Corporation, containing 50-60% by mass of piperazine pyrophosphate, 35-45% by mass of melamine pyrophosphate, and 3-6% by mass of zinc oxide) is used.

[0320] 3. Copolymer (component C)

[0321] α-Olein / maleic anhydride copolymer (manufactured by Mitsubishi Chemical Corporation, DIACANNA 30M, weight average molecular weight 7800).

[0322] 4. Metal hydroxide flame retardant (component d)

[0323] Magnesium hydroxide (particle size 4μm)

[0324] 5. Fluorine anti-drip agent (component e)

[0325] Mitsubishi Chemical Corporation METABLEN (registered trademark) A-type grade name "MZX-4" (PP / A-3000 = 80 / 20 masterbatch) ※PTFE masterbatch

[0326] 6. Glass fiber mat (Y component)

[0327] A vortex mat (weight per unit area 880 g / m2) made of continuous roving glass fiber (fiber diameter 23 μm) was used. 2 ) is a glass fiber mat obtained by needle punching.

[0328] 7. Material of metal layer

[0329] Metal plate 1: Iron plate (equivalent to SPCC) 0.3mm

[0330] Metal plate 2: Aluminum plate (A1100) 0.3mm

[0331] Metal plate 3: Copper plate (C1100) 0.3mm

[0332] Metal plate 4: Stainless steel plate (SUS304) 0.3mm

[0333] 8. Adhesive layer material

[0334] Adhesive film 1: Hot melt film "KuranBeter (registered trademark) P-6700" manufactured by Kurabo Co., Ltd., thickness 30 μm

[0335] Preparation Example 1 (Preparation of PP composition 1)

[0336] The above-mentioned component a, component b1, component b2, and component c were melt-kneaded (230° C.) in a ratio of 68 mass %, 30 mass %, and 2 mass %, to prepare pellets of a polypropylene resin composition (resin composition (X)).

[0337] Preparation Example 2 (Preparation of PP composition 2-1)

[0338] A polypropylene resin composition (resin composition (Y1)) was prepared by melt kneading (230° C.) the component a at a ratio of 48% by mass, the component b at 20% by mass, the component c at 2% by mass, and the component d at 30% by mass.

[0339] Preparation Example 3 (Preparation of PP composition 2-2)

[0340] A polypropylene resin composition (resin composition (Y2)) was prepared by melt kneading (230° C.) at a ratio of 58% by mass of the component a, 20% by mass of the component b, 2% by mass of the component c, and 20% by mass of the component d.

[0341] Preparation Example 4 (Preparation of PP composition 2-3)

[0342] A polypropylene resin composition (resin composition (Y3)) was prepared by melt kneading (230° C.) 58% by mass of the component a, 10% by mass of the component b, 2% by mass of the component c, and 30% by mass of the component d.

[0343] Preparation Example 5 (Preparation of PP composition 3-1)

[0344] A polypropylene resin composition (resin composition (Z1)) was prepared by melt kneading (230° C.) at a ratio of 77.8% by mass of the component a, 20% by mass of the component b, 2% by mass of the component c, and 0.2% by mass of the component e.

[0345] Preparation Example 6 (Preparation of PP composition 3-2)

[0346] A polypropylene resin composition (resin composition (Z2)) was prepared by melt kneading (230° C.) at a ratio of 82.8% by mass of the component a, 15% by mass of the component b, 2% by mass of the component c, and 0.2% by mass of the component e.

[0347] Comparative Preparation Example 1

[0348] In Preparation Example 1, pellets of a polypropylene-based resin composition (PP composition) were prepared in the same manner as in Preparation Example 1, except that the component b1 and the component c were not used.

[0349] Example 1 (First Embodiment)

[0350] The method for producing the resin sheet (punchable sheet 10) for forming the layer (A) in the laminate of the present invention is as follows: Figure 1 It should be noted that Figure 1 The layer structure before the glass fiber mat is impregnated with the thermoplastic resin composition is shown.

[0351] The pellets of the resin composition (X) granulated in Preparation Example 1 were fed into an extruder, melted, and extruded into a sheet, and the extruded sheet-like thermoplastic resin composition (X) (hereinafter referred to as "sheet X") was Figure 1 11), and laminated by inserting glass fiber mat 12 from both sides. Next, laminate sheet X ( Figure 1 13), while applying a pressure of 0.3 MPa using a laminator, heating and pressing at 230°C for 4 minutes, and then cooling and solidifying it, thereby obtaining a resin sheet (punchable sheet, thickness; 2.5 mm) (refer to Figure 1 The resin composition in the sheet X was impregnated into the glass fiber mat to obtain an integrated resin sheet (a punchable sheet, described as an "integrated sheet" in Table 1).

[0352] Next, the integrated sheet and the metal plate 1 were laminated with the adhesive film 1 interposed therebetween, and heated and pressed at 230° C. for 90 seconds to obtain a laminated body in which the sheet and the metal plate 1 were bonded. The results of the evaluations performed by the above methods are shown in Table 1.

[0353] Example 2 (First Embodiment)

[0354] A laminated body in which the integration sheet and the metal plate 2 were bonded was obtained in the same manner as in Example 1 except that the metal plate 2 was used instead of the metal plate 1. Table 1 shows the composition and the results of the evaluation by the above-mentioned methods.

[0355] Example 3

[0356] A sheet in which the glass fiber mat and the resin composition (X) were integrated was obtained in the same manner as in Example 1.

[0357] Next, a laminated body was obtained by laminating the above-mentioned sheet and the metal plate 3. Table 1 shows the results of the evaluations performed by the above-mentioned methods.

[0358] Example 4

[0359] A laminated body in which the sheet and the metal plate 4 were laminated was obtained in the same manner as in Example 3 except that the metal plate 4 was used as the metal plate instead of the metal plate 3. Table 1 shows the results of the evaluations performed by the above methods.

[0360] Comparative Example 1

[0361] Table 1 shows the results of the evaluation using only the resin sheet (integrated sheet, punchable sheet) produced in Example 1.

[0362] Example 5 (Second Embodiment)

[0363] The evaluation was performed by the above method using the resin sheet (punchable sheet, thickness: 2.5 mm) produced in Example 1. The results are shown in Table 2.

[0364] Example 6 (Second embodiment)

[0365] A punchable sheet (thickness: 2.5 mm) was obtained in the same manner as in Example 1 except that the resin composition (Y1) prepared in Preparation Example 2 was used instead of the resin composition (X) granulated in Preparation Example 1. The resin composition (Y1) was impregnated with a glass fiber mat to obtain an integrated sheet. The results obtained by the evaluation method described above are shown in Table 2.

[0366] Example 7 (Second Embodiment)

[0367] A punchable sheet (thickness: 2.5 mm) was obtained in the same manner as in Example 1 except that the resin composition (Y2) prepared in Preparation Example 3 was used instead of the pellets of the resin composition (X) granulated in Preparation Example 1. The resin composition (Y2) was impregnated with a glass fiber mat to obtain an integrated sheet. The results obtained by the evaluation method described above are shown in Table 2.

[0368] Example 8 (Second embodiment)

[0369] A punchable sheet (thickness: 2.5 mm) was obtained in the same manner as in Example 1 except that the resin composition (Y3) prepared in Preparation Example 4 was used instead of the pellets of the resin composition (X) granulated in Preparation Example 1. The resin composition (Y3) was impregnated with a glass fiber mat to obtain an integrated sheet. The results obtained by the evaluation method described above are shown in Table 2.

[0370] Example 9 (Second Embodiment)

[0371] A punchable sheet (thickness: 2.5 mm) was obtained in the same manner as in Example 1 except that the resin composition (Z1) prepared in Preparation Example 5 was used instead of the pellets of the resin composition (X) granulated in Preparation Example 1. The resin composition (Z1) was impregnated with a glass fiber mat to obtain an integrated sheet. The results obtained by the evaluation method described above are shown in Table 2.

[0372] Example 10 (Second Embodiment)

[0373] A punchable sheet (thickness: 2.5 mm) was obtained in the same manner as in Example 1 except that the resin composition (Z2) prepared in Preparation Example 6 was used instead of the pellets of the resin composition (X) granulated in Preparation Example 1. The resin composition (Z2) was impregnated with a glass fiber mat to obtain an integrated sheet. The results obtained by the evaluation method described above are shown in Table 2.

[0374] Comparative Example 2

[0375] In Example 1, a sheet was obtained in the same manner as in 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 composition and evaluation results are shown in Table 2.

[0376]

[0377]

[0378] As shown in Examples 1 to 4 as the first embodiment, the flame shielding property of the laminate of the present invention is excellent, and the flame is shielded even after 600 seconds (10 minutes). In addition, the rise in the highest temperature reached on the back side until 600 seconds (10 minutes) is less than 300°C, and it has excellent thermal insulation. In contrast, in Comparative Example 1, the effect of suppressing the rise in the highest temperature reached on the back side is low, and the thermal insulation is poor.

[0379] In addition, in Examples 5 to 10 as the second mode, as shown in Table 2, the flame shielding property of the punchable sheet as one mode of the present invention is excellent, and the flame is shielded even after 15 minutes. In addition, the back temperature rise at 600 seconds (10 minutes) is suppressed, and the heat insulation is excellent. In contrast, in Comparative Example 2, the flame penetrates to the back in about 140 seconds.

[0380] Industrial Applicability

[0381] The laminate of the present invention has high flame shielding and heat insulation properties, and is therefore useful as a material for various industrial parts requiring high safety, such as aircraft, ships, automobile parts, electrical and electronic equipment parts, and building materials. In particular, it can be suitably used in various housings and frames of batteries that have conventionally used metals, contributing to the safety of automobiles, and can be expected to improve energy efficiency and reduce CO2 emissions due to lightweighting.

Claims

1. A laminate comprising: A layer (A) in which a thermoplastic resin composition (X) and an inorganic fiber (Y) are integrated, and The thermal conductivity of layer (B) in the thickness direction is higher than that of layer (A). The thermoplastic resin composition (X) comprises a thermoplastic resin (a) and a heat-expandable flame retardant (b1).

2. The laminate according to claim 1, wherein The thermal conductivity of the laminate measured in the thickness direction is 0.32 W / mK or more.

3. The laminate according to claim 1 or 2, wherein: The thermal conductivity of the layer (B) measured in the thickness direction is 10 W / mK to 400 W / mK.

4. The laminate according to claim 1 or 2, wherein: The layer (B) is a metal layer.

5. The laminate according to claim 4, wherein The thickness of the metal layer is 0.05-2.0 mm.

6. The laminate according to claim 1 or 2, wherein: The thermoplastic resin composition (X) contains a polypropylene-based resin.

7. The laminate according to claim 1 or 2, wherein: The thermoplastic resin composition (X) comprises a copolymer of an α-olefin and an unsaturated carboxylic acid.

8. The laminate according to claim 1 or 2, wherein: The heat-expandable flame retardant (b1) includes a phosphorus-based flame retardant.

9. The laminate according to claim 8, wherein The phosphorus-based flame retardant includes a compound having a melamine structure or a piperazine structure.

10. The laminate according to claim 1 or 2, wherein: The inorganic fibers (Y) include glass fibers.

11. The laminate according to claim 1 or 2, wherein the mat composed of the inorganic fibers (Y) is impregnated with the thermoplastic resin composition (X).

12. The laminate according to claim 1 or 2, wherein: The thermoplastic resin composition (X) contains zinc oxide.

13. A method for producing a laminate, comprising: A step of impregnating a mat composed of inorganic fibers (Y) with a thermoplastic resin composition (X) to produce an integrated layer (A), A step of laminating a layer (B) having a higher thermal conductivity in the thickness direction than the layer (A) on the integrated layer (A).

14. The method for producing a laminate according to claim 13, wherein: In the step of producing the integrated layer (A), a mat composed of inorganic fibers (Y) and a resin sheet composed of the thermoplastic resin composition (X) are stacked and hot-pressed.

15. The method for producing a laminate according to claim 13 or 14, wherein: The layer (B) is a metal layer.

16. A casing or a frame using the laminate according to claim 1 or 2.

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