Laminate comprising metal layer and resin layer, and method for producing same

Abstract

This laminate is obtained by laminating a resin layer and a metal layer 102, wherein the metal layer has holes 104 and bent portions 105, within the resin layer, extending from the circumferential edge of the holes toward the outside in the radial direction of the holes.

Description

Laminated body of metal layer and resin layer and method for producing the same

[0001] The present invention relates to a laminated body of a metal layer and a resin layer, and a method for producing the same.

[0002] Regarding the technology of shielding an electric field using metal and resin, various studies have been made in the past. In Patent Document 1, unevenness is formed on the mold for forming the back surface of the outer plate, an aluminum foil and SMC (Sheet Molding Compound) are stacked and set on the mold, and a method for forming an electromagnetic shielding resin outer plate in which the aluminum foil is joined to the resin by heating and pressing is described.

[0003] Patent Document 2 relates to a method for forming a body that shields electromagnetic waves by laminating a resin and a metal sheet. In particular, it includes a step of preparing metal sheets having different laminated regions and fixing them to a mold, and a step of setting a base material in the mold and performing insert molding. Further, it is characterized by a step of laminating a hot melt layer on the metal sheet and forming it while heating, and a step of preparing a protective layer.

[0004] Japanese Patent Application Laid-Open No. 4-110278, Japanese Patent Application Laid-Open No. 2022-144867

[0005] However, in the electromagnetic shielding resin outer plate described in Patent Document 1, a large number of holes are formed in the aluminum foil so that the resin protrudes to the back side of the holes during molding, and the bonding strength between the aluminum foil and the resin layer is only improved by this anchor effect, and the bonding strength is not sufficient.

[0006] In the electromagnetic wave shielding body described in Patent Document 2, since a hot melt layer is provided to bond the resin and the metal, the number of man-hours for bonding increases. Also, the weight of the electromagnetic wave shielding body increases by the amount of the hot melt layer. Therefore, an object of the present invention is to provide a laminated body in which the bonding strength between the metal layer and the resin layer is sufficiently ensured.

[0007] As a result of diligent research, the present inventors have found that the above problems can be solved by the following means, and have arrived at the present invention. 1. A laminate comprising a resin layer and a metal layer, wherein the metal layer has a hole and a bend portion extending from the periphery of the hole toward the interior of the resin layer. 2. The laminate according to 1, wherein the metal layer has a main body portion other than the bend portion, and when the laminate is viewed from the metal layer side and an orthographic projection is observed, the boundary between the main body portion and the hole is the periphery. 3. The laminate according to either 1 or 2, wherein the thickness of the metal layer is 0.03 mm or more and less than 1 mm, and the diameter of the maximum inscribed circle of the hole is greater than 0.1 mm. 4. The laminate according to any one of 1 to 3, wherein a plurality of bend portions extending from the periphery of one of the holes. 5. 1. The laminate according to any one of 1 to 4, wherein the laminate has a top surface portion and an upright surface portion, and the metal layer of the top surface portion has at least one of the holes. 6. The laminate according to any one of 1 to 5, wherein the bend portion is bent from the planar side of the laminate on the metal layer side toward the interior of the resin layer, and resin is present between the bend portion and the planar side of the metal layer. 7. The laminate according to any one of 1 to 6, wherein the resin layer contains reinforcing fibers. 8. The laminate according to any one of 1 to 7, wherein the metal layer shields at least one of an electric field or a magnetic field. 9. The laminate according to any one of 1 to 8, further comprising a sealing material for blocking the holes. 10. A method for manufacturing the laminate according to any one of 1 to 8, comprising laminating a resin material to be the resin layer and a metal plate to be the metal layer, and press molding them using an upper molding die and a lower molding die, wherein the laminate is manufactured by following steps 101 to 301. Step 101: A hole with a barb that will become the bend portion is made in the metal plate. Step 201: With the barb facing the resin material, the metal plate and the resin material are placed into the lower molding mold. Step 301: The upper molding mold is closed, the metal plate and the resin material are integrally molded, and the barb is bent radially outward from the hole to form the bend portion.

[0008] The laminate of the present invention has a metal layer with a hole and a bend portion that extends radially outward from the periphery of the hole within the resin layer, allowing for highly reproducible bonding between the resin layer and the metal layer. Furthermore, by using the "reverse" created when making a hole in the metal plate as the bend portion and laminating the metal layer and resin layer by integral molding, the adhesive layer and bonding process can be omitted. Moreover, by utilizing the "reverse" as the bend portion, the process of removing the "reverse," which was originally considered unnecessary, can be omitted, and since the "reverse" is not removed, waste is also reduced.

[0009] Schematic diagram of the laminate of the present invention. Schematic cross-sectional view of the laminate of the present invention. Enlarged view of the area around hole 104. Schematic cross-sectional view of the metal layer (main body and bend portion) of the present invention. Exploded perspective view of the battery box. Schematic diagram of the laminate with a hat-shaped cross-section. Forming by placing only metal plates in a mold. Forming by laminating metal plates and resin material into a single unit. Forming by placing only metal plates in a mold. Forming by laminating metal plates and resin material into a single unit. Perspective view showing that multiple burrs 109 are provided in the burred hole 204 provided in the metal plate. Created by process 101. An example of evaluating electric field shielding performance in which the electric field is not shielded at all in the region between 0.1 MHz (1.00E+05) and 1 GHz (1.00E+09) (the region indicated by the arrow 801 in Figure 9A). Examples of evaluation of electric field shielding performance, showing an electric field shielding performance of approximately 20 dB in the region between 0.1 MHz and 1 GHz. Examples of evaluation of electric field shielding performance, showing an electric field shielding performance of approximately 33 dB in the region between 0.1 MHz and 1 GHz. Evaluation of the electromagnetic wave shielding performance of the metal layer used in Example 1. Evaluation of the electromagnetic wave shielding performance of the metal layer used in Example 2. Evaluation of the electromagnetic wave shielding performance of the metal layer used in Example 3. Evaluation of the electromagnetic wave shielding performance of the metal layer used in Example 4.

[0010] The embodiments of the present invention will be described below, but the present invention is not limited thereto.

[0011] [Metal Plate] The laminate of the present invention is preferably manufactured by laminating a resin layer and a metal plate and press molding using an upper molding die and a lower molding die (sometimes collectively referred to as upper and lower molding dies). In other words, the metal layer is preferably obtained by molding a metal plate.

[0012] There are no particular limitations on the type of metal sheet that will become a metal layer after forming. Examples include pure aluminum, aluminum alloys containing magnesium (Mg), copper (Cu), zinc (Zn), silicon (Si), manganese (Mn), etc., pure copper, copper alloys containing nickel (Ni), tin (Sn), zinc (Zn), aluminum (Al), lead (Pb), phosphorus (P), etc., and pure magnesium, magnesium alloys containing aluminum (Al), zinc (Zn), manganese (Mn), zirconium (Zr), etc. Aluminum, aluminum alloys, copper, and copper alloys are particularly preferred. In this specification, the metal sheet is in its pre-forming state and will become a metal layer after forming. The elongation at break of the metal sheet is preferably 5% or more and less than 80%. Here, the elongation at break of the metal sheet is the elongation at break of the metal sheet that will become a metal layer when measured by the tensile test method for metallic materials specified in JIS Z2241:2011. The elongation at break of the metal sheet is measured with respect to the thickness of the metal sheet used. For example, when using a metal plate with a thickness of 0.2 mm, the elongation at break of the 0.2 mm thick metal plate is measured. Specifically, a test specimen with a length of 120 mm and a width of 20 mm (parallel section) is prepared from the 0.2 mm thick metal plate, and a tensile test is performed until the specimen breaks, with the original gauge length Lo = 80 mm. When the final gauge length of the specimen after breakage is denoted as Lu, the permanent elongation after breakage (Lu - Lo) is expressed as a percentage of the original gauge length Lo, and this is called the elongation at break. If the elongation at break of the metal layer is 5% or more and less than 80%, the metal layer after molding by the mold is less likely to break.

[0013] [Metal layer: Shielding of electric or magnetic fields] 1. It is preferable that the metal layer shields at least one of the electric or magnetic fields. It is preferable that the shielding of the electric or magnetic field by the metal layer is 10 decibels or more in at least a part of the region between 0 MHz and 3000 MHz. It is more preferable that the shielding of the electric or magnetic field is 20 decibels or more, and even more preferable that it is 30 decibels or more. Here, the shielding can be expressed as 10 times (decibels) the common logarithm of the ratio of the power of the electromagnetic wave before passing through the shielding layer to the power of the electromagnetic wave after passing through the shielding layer.

[0014] The preferred range for each shielding region is that in at least 50% of the region between 0 MHz and 3000 MHz, the shielding of the electric or magnetic field is preferably 10 decibels or more. More preferably, the shielding of the electric or magnetic field is 20 decibels or more, and even more preferably 30 decibels or more. "In at least 50% of the region between 0 MHz and 3000 MHz" means that the shielding region may be continuous or discontinuous within the region between 0 MHz and 3000 MHz.

[0015] As for the preferred range for each shielding region, it is preferable that the shielding of the electric or magnetic field is 10 decibels or more in all regions from 0 MHz to 3000 MHz. It is more preferable that the shielding of the electric or magnetic field is 20 decibels or more, and even more preferable that it is 30 decibels or more.

[0016] 2. The following describes more preferable shielding properties. The metal layer shields at least one of the electric field or magnetic field, and it is preferable that the shielding of the electric field or magnetic field is 10 decibels or more in at least a portion of the region between 0 MHz and 100 MHz. It is more preferable that the shielding of the electric field or magnetic field is 20 decibels or more, and even more preferable that it is 30 decibels or more.

[0017] The preferred range for each shielding region is that in at least 50% of the region between 0 MHz and 100 MHz, the shielding of the electric or magnetic field is preferably 10 decibels or more. More preferably, the shielding of the electric or magnetic field is 20 decibels or more, and even more preferably 30 decibels or more. "In at least 50% of the region between 0 MHz and 100 MHz" means that the shielding region between 0 MHz and 100 MHz may be continuous or discontinuous.

[0018] The preferred range for each shielding region is that the shielding of the electric or magnetic field is 10 decibels or more in all regions from 0 MHz to 100 MHz. It is more preferable that the shielding of the electric or magnetic field is 20 decibels or more, and even more preferable that it is 30 decibels or more.

[0019] Figures 9A to 9C illustrate the field shielding performance. The horizontal axis represents frequency (Hz), and the vertical axis represents field shielding performance (dB). For example, in Figure 9A, in the region between 0.1 MHz (1.00E+05) and 1 GHz (1.00E+09) (the region indicated by the 801 arrow in Figure 9A), the field is not shielded at all. In the region between 0.1 MHz and 1 GHz in Figure 9B, a field shielding performance of approximately 20 dB is shown. In the region between 0.1 MHz and 1 GHz in Figure 9C, a field shielding performance of approximately 33 dB is shown.

[0020] [Thickness of the metal layer] In the laminate of the present invention, there are no particular limitations on the thickness of the metal layer, but it is preferably 0.03 mm or more and 1 mm or less, more preferably 0.05 mm or more and 0.5 mm or less, even more preferably 0.1 mm or more and 0.4 mm or less, and even more preferably 0.1 mm or more and 0.3 mm or less. A metal layer thickness exceeding 0.03 mm is preferable because it allows the bend portion to sufficiently penetrate the resin layer. The thickness of the metal layer can be measured using the average thickness of 10 points.

[0021] From the viewpoint of electric field shielding performance, in order to achieve an electric field shielding performance of 60 dB or more in the region between 0.1 MHz and 1 GHz, the thickness of the metal layer is preferably at least 0.2 mm, and more preferably 0.5 mm or more.

[0022] [Ratio of metal layer to resin layer] There are no particular limitations on the volume ratio Vx of the resin layer and the volume ratio Vy of the metal layer, but Vx:Vy is preferably 99:1 to 60:40, more preferably 98:2 to 66:34, and even more preferably 95:5 to 80:20. Within this range, the shielding layer does not become too thick, and moldability is good.

[0023] [Pores in the Metal Layer] 1. Overview The laminate of the present invention comprises a resin layer and a metal layer, the metal layer having pores, and the metal layer extends toward the interior of the resin layer, with bends formed from the periphery of the pores. Figure 1 is a schematic perspective view showing a laminate 101 according to an embodiment of the present invention, and Figure 2A is a schematic cross-sectional view taken along the line IIA-IIA in Figure 1. The laminate 101 has a metal layer 102 and a resin layer 103.

[0024] 2. Bend Section 2.1. Extending from the Periphery As shown in Figure 2A, the metal layer 102 has a bend section 105 extending from the periphery of the hole 104 toward the interior of the resin layer 103. Figure 2B is an enlarged view of section IIB in Figure 2A. The periphery 106 of the hole 104 refers to the area around the hole 104 made in the metal layer 102. Figure 3 is a schematic cross-section showing the bend section 105 of the metal layer 102 and the main body 107 other than the bend section 105. As shown in Figure 3, the periphery 106 of the hole 104 refers to the point where the main body 107 of the metal layer 102 begins to bend. In other words, the end of the bend section 105 and the periphery 106 of the hole 104 are different, and the bend section 105 is formed continuously from the periphery 106 of the hole 104. In other words, when the laminate 101 is viewed from the metal layer 102 side and observed in orthographic projection, the boundary between the main body 107 and the hole 104 becomes the periphery. Viewing the laminate 101 from the metal layer 102 side means viewing it from the top to the bottom of the Z-axis plane of the paper.

[0025] 2.2. In this embodiment, the metal layer 102, which extends radially outward from the hole within the resin layer, extends radially outward from the hole 104 within the resin layer 103, with a bent portion 105 formed from the periphery of the hole 104. As shown in Figures 2A, 2B, and 3, the bent portion 105 has a fishhook shape and bites into the resin layer 103. As a result, the metal layer 102 is fixed to the resin layer 103, making it difficult for displacement to occur. Unlike the invention that simply makes many holes in a metal plate and improves the bonding strength between the metal layer and the resin layer by an anchoring effect by causing the resin to protrude to the back side of the holes during molding, this embodiment can significantly improve the bonding strength. Furthermore, although the metal layer 102 is more prone to stretching due to the difference in linear expansion between the metal layer 102 and the resin layer 103, as in this embodiment, the bend portion 105 bites into the resin layer 103, so even if the metal layer 102 stretches more than the resin layer 103, the main body portion 107 only lifts slightly, and the metal layer 102 does not peel off.

[0026] 2.3 Multiple Bends It is preferable to form multiple bends 105 from the periphery 106 of a single hole 104. The bends 105 extend downward in the plane of the Z-axis as shown in Figures 1, 2A, 2B, and 3, and further extend radially outward from the hole in the XY plane as shown in Figures 1, 2A, 2B, and 3. This improves the bonding strength between the resin layer 103 and the metal layer 102, making it less likely for displacement to occur regardless of the direction from which force is applied. In order to form multiple bends 105 from the periphery 106 of a single hole 104, it is preferable to provide multiple barbs on the periphery 106 of the burred hole 204 when providing the burred hole 204 in the metal plate 102. Figure 8 illustrates a drawing in which a burred hole 204 and barbs 109 are provided from the periphery of the burred hole 204. The burr 109 shown in Figure 8 is preferably created by the process 101 described later. The burred hole 204 is a hole made in the metal plate that will become the metal layer 102, and when the metal plate becomes the metal layer 102, it becomes a hole 104 in the metal layer 102.

[0027] 2.4 The resin bend portion 105 between the bend portion and the flat surface on the metal layer side of the laminate is preferably bent from the flat surface 110 on the metal layer 102 side of the laminate 101 toward the interior of the resin layer 103, with resin 108 present between the bend portion 105 and the flat surface 110. Figure 2B illustrates the resin 108 between the bend portion 105 and the flat surface 110. The resin 108 forms an undercut, which further increases the bonding strength of the metal plate 102.

[0028] 3. Number, arrangement, and area ratio of holes The metal layer 102 has holes 104. There are no particular limitations on the number, arrangement, and area ratio of holes 104 provided in the metal layer 102, but in order to provide an electric field shielding performance of 60 dB or more in the region of 0.1 MHz to 1 GHz, it is preferable to satisfy the following (1) and (2). (1) The distance (pitch) between holes 104 is preferably 15 mm to 60 mm, and more preferably 20 mm to 60 mm. (2) There are no particular limitations on the shape of the holes 104, and they may be polygonal, circular, or elliptical. Among these, circular is preferred. (3) There are no particular limitations on the size of the holes 104, but the diameter of the maximum inscribed circle of the hole 104 is preferably 0.1 mm or more, more preferably 0.5 mm to 5 mm, and even more preferably 0.5 mm to 4 mm. If the shape of the hole 104 is circular, the diameter of the largest inscribed circle of the hole 104 is equal to the diameter of the hole 104. The number of holes 104 depends on the size of the hole 104, but if the holes 104 are small and few in number, the electric field shielding performance is excellent, but the bonding force between the resin layer and the metal layer is weak. If the holes 104 are large and many in number, the shielding performance of the electric field or magnetic field decreases, but the bonding force becomes stronger.

[0029] [Sealing the Holes] It is preferable to seal the holes 104 with a sealing material (not shown). The sealing material is for preventing gas leakage and is intended to block gas from escaping from the holes 104. There are no particular limitations on the sealing material, but the following sealing materials can be listed: (1) Silicone sealant: Excellent weather resistance and water resistance, used for bonding glass, metal, plastic, etc. (2) Acrylic sealant: Paintable, suitable for repairing gaps and cracks in interiors. (3) Polyurethane sealant: Has high adhesive strength and elasticity, used for sealing the exterior walls and roofs of buildings. (4) Butyl sealant: Has high waterproofness, suitable for sealing window frames and door frames. (5) Epoxy sealant: Becomes very strong after curing, used for repairing and reinforcing structures.

[0030] [Regarding adhesive layers and other fastenings] In order to increase the bonding strength between the metal layer 102 and the resin layer 103 of the laminate 101 by the holes 104 and vents 105 described above, it is preferable not to provide an adhesive layer between the metal layer 102 and the resin layer 103. Similarly, it is preferable not to provide any other fastening members that fasten the metal layer 102 and the resin layer 103.

[0031] [Resin Layer] 1. Thermoplastic Resin When the resin contained in the resin layer 103 is a thermoplastic resin, the type is not particularly limited, and one having a desired softening point or melting point can be appropriately selected and used. As the above thermoplastic resin, one with a softening point in the range of 180°C to 350°C is usually used, but it is not limited to this.

[0032] Examples of thermoplastic resins include polyolefin resins, polystyrene resins, polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyethernitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyetherketone resins, thermoplastic urethane resins, fluoropolymer resins, thermoplastic polybenzimidazole resins, and the like.

[0033] The thermoplastic resin used in the resin layer 103 may be of one type or two or more types. Examples of using two or more thermoplastic resins in combination include, but are not limited to, using thermoplastic resins with different softening points or melting points, or using thermoplastic resins with different average molecular weights. When using thermoplastic resins, it is more preferable to use polyolefin resin, and even more preferable to use polypropylene resin.

[0034] 2. Thermosetting resin The resin used in the resin layer 103 may be a thermosetting resin. When using a thermosetting resin, it is preferable that it be an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, or a phenolic resin. One type of resin may be used alone, or two or more types may be used in combination.

[0035] Furthermore, if the resin layer 103 contains reinforcing fibers as described later, a sheet molding compound containing reinforcing fibers (sometimes called SMC) may be used. Due to its high moldability, sheet molding compounds can be easily molded even into complex shapes. Sheet molding compounds have higher fluidity and formability compared to continuous fibers, making it easy to create ribs and bosses.

[0036] 3. Other additives: The resin layer 103 may contain various fibrous or non-fibrous fillers of organic or inorganic fibers, flame retardants, UV inhibitors, stabilizers, mold release agents, pigments, softeners, plasticizers, surfactants, etc., to the extent that it does not impair the objectives of the present invention. When a thermosetting resin is used, it may also contain thickeners, curing agents, polymerization initiators, polymerization inhibitors, etc. Additives may be used individually or in combination of two or more.

[0037] [Resin layer containing reinforcing fibers: Reinforcing fibers] The resin layer 103 preferably contains reinforcing fibers. In this specification, the reinforcing fibers are preferably at least one selected from the group consisting of carbon fibers, aramid fibers, and glass fibers. More preferably, the reinforcing fibers are carbon fibers or glass fibers. The reinforcing fibers when the resin layer contains reinforcing fibers will be described below.

[0038] [Reinforcement Fiber: Carbon Fiber] 1. General Carbon Fibers When using carbon fibers, polyacrylonitrile (PAN) carbon fibers, petroleum / coal pitch carbon fibers, rayon carbon fibers, cellulose carbon fibers, lignin carbon fibers, phenolic carbon fibers, etc. are generally known, but in the present invention, any of these carbon fibers can be suitably used. Among them, in the present invention, it is preferable to use polyacrylonitrile (PAN) carbon fibers because they have excellent tensile strength. As a PAN carbon fiber, for example, Teijin Limited's carbon fiber "Tenax" (registered trademark) STS40-24KS (average fiber diameter 7 μm) can be used.

[0039] 2. The carbon fibers used in the carbon fiber sizing agent resin layer 103 may have a sizing agent attached to their surface. When using carbon fibers with a sizing agent attached, the type of sizing agent can be appropriately selected according to the type of carbon fiber and the type of resin, and is not particularly limited.

[0040] [Reinforcement Fiber: Glass Fiber] The case where the reinforcement fiber used in the resin layer 103 is glass fiber will be explained below. 1. Glass Fibers in General Any glass fiber that is generally referred to as glass fiber may be used in the resin layer 103. The glass composition is not particularly limited to A glass, C glass, E glass, etc., and may contain components such as TiO2, SO3, P2O5 depending on the case. As a glass fiber, for example, Nitto Boseki's glass fiber E-glass RS240QR-483 (count: 2400g / 1000m) can be used.

[0041] 2. The glass fiber used in the sizing agent resin layer 103 of the glass fiber may have a sizing agent attached to its surface. When using glass fibers with a sizing agent attached, the type of the sizing agent can be appropriately selected according to the type of glass fiber and the type of resin, and is not particularly limited. The glass fiber is preferably used which has been pretreated with a conventionally known coupling agent such as an organic silane-based compound, an organic titanium-based compound, an organic borane-based compound, and an epoxy-based compound.

[0042] [Reinforcing fiber: fiber length] The reinforcing fiber is preferably a discontinuous fiber. When using discontinuous fibers, the formability is improved compared to a fiber-reinforced plastic using only continuous fibers, and it becomes easier to create a complex resin layer. Since the weight average fiber length of the reinforcing fiber does not change before and after molding, by examining the weight average fiber length of the reinforcing fiber in the resin layer, the weight average fiber length Lw of the reinforcing fiber contained in the resin material can be known.

[0043] The weight average fiber length Lw of the reinforcing fiber is preferably 1 mm or more, and more preferably 3 mm or more. The weight average fiber length Lw of the reinforcing fiber is more preferably 3 mm or more and 100 mm or less, more preferably 3 mm or more and 80 mm or less, and still more preferably 5 mm or more and 60 mm or less. If the weight average fiber length Lw of the reinforcing fiber is 100 mm or less, when the resin material is press-molded for production, the fluidity of the resin material is less likely to decrease, and it is easy to create a desired shape. Also, when the weight average fiber length Lw is 1 mm or more, the mechanical strength of the obtained resin layer is less likely to decrease, which is preferable.

[0044] The weight average fiber length Lw and the number average fiber length Ln of the reinforcing fiber are obtained by the following formulas (1) and (2). In the resin layer formed by injection molding, the weight average fiber length of the reinforcing fiber is about 0.1 to 0.3 mm. Therefore, when the weight average fiber length of the reinforcing fiber is 1 mm or more and 100 mm or less, it is preferable to create the resin layer by press molding.

[0045] In the resin layer 103, discontinuous reinforcing fibers having different fiber lengths may be used in combination. In other words, the discontinuous reinforcing fibers used in the resin layer 103 may have a single peak in the distribution of the weight average fiber length, or may have a plurality of peaks.

[0046] [Resin layer containing reinforcing fibers: number average fiber length Ln and weight average fiber length Lw of reinforcing fibers] Generally, when the fiber length of each reinforcing fiber is Li, the number average fiber length Ln and the weight average fiber length Lw are obtained by the following formulas (1) and (2). The units of the number average fiber length Ln and the weight average fiber length Lw are mm.

[0047] Here, "I" indicates the number of the measured reinforcing fibers.

[0048] When the fiber length is a constant length, the number average fiber length and the weight average fiber length are the same value. The extraction of the reinforcing fibers from the resin layer can be performed, for example, by subjecting them to a heat treatment at about 500 ° C for 1 hour to remove the resin in the furnace.

[0049] The average fiber length can be obtained, for example, by measuring the fiber lengths of 100 fibers randomly extracted from the resin layer to the unit of 1 mm using a vernier caliper or the like and based on formula (1) or formula (2).

[0050] When short fibers that cannot be measured with a vernier caliper are included, after removing the resin, the obtained reinforcing fibers are put into water containing a surfactant and sufficiently stirred by ultrasonic vibration. The stirred dispersion is randomly sampled with a measuring spoon to obtain an evaluation sample, and it is advisable to measure the lengths of 3000 fibers with an image analyzer Luzex AP manufactured by Nireco Corporation. Using the measured values of the fiber lengths, the number average fiber length Ln and the weight average fiber length Lw can be obtained in the same manner as in the above formulas (1) and (2).

[0051] [Resin layer containing reinforcing fibers: Fiber volume ratio of reinforcing fibers] There are no particular limitations on the fiber volume ratio Vf of reinforcing fibers, but 20 to 70% is preferred, 25 to 60% is more preferred, and 30 to 55% is even more preferred. The fiber volume ratio (Vf, unit: volume %) is the ratio of the volume of reinforcing fibers to the total volume of the resin layer, which includes not only the reinforcing fibers and resin but also other additives.

[0052] While there are no specific methods for analyzing the volume ratio of reinforcing fibers, it is recommended to measure it as follows: Cut a sample from the resin layer, burn off the resin in a furnace at 500°C for 1 hour, and weigh the sample before and after treatment to calculate the mass of the reinforcing fibers, resin, and other additives. Next, use the specific gravity of each component to calculate the volume ratio of reinforcing fibers to resin: Vf = 100 × volume of reinforcing fibers / (volume of reinforcing fibers + volume of resin + volume of other additives)

[0053] [Resin layer containing reinforcing fibers: Reinforcing fibers dispersed in the in-plane direction] The reinforcing fibers used in the resin layer 103 are discontinuous fibers and are preferably dispersed in the in-plane direction of the resin layer. Furthermore, in order to disperse in the in-plane direction in the resin layer, it is preferable to disperse the reinforcing fibers contained in the resin material in the in-plane direction. Dispersion of reinforcing fibers in the in-plane direction means that the fiber axes of the reinforcing fibers are oriented in the in-plane direction. It is preferable that the angle that the fiber axes of the reinforcing fibers make with the in-plane direction is 45° or less.

[0054] 1. In-plane direction: The in-plane direction refers to an undefined direction of parallel planes perpendicular to the thickness direction of the resin material or resin layer. The resin material is preferably in the form of a plate.

[0055] 2. Randomly dispersed in two dimensions: It is preferable that the reinforcing fibers are randomly dispersed in two dimensions in the in-plane direction. In regions where the resin material is press-molded without flowing, the shape of the reinforcing fibers is largely maintained before and after molding. Therefore, it is also preferable that the reinforcing fibers contained in the non-flowing region of the molded resin layer are similarly randomly dispersed in two dimensions in the in-plane direction.

[0056] Here, "randomly dispersed in two dimensions" means that the reinforcing fibers are oriented in a disordered manner within the in-plane direction of the resin material or resin layer, rather than in a specific direction such as one direction, and are arranged within the sheet surface without exhibiting a specific orientation overall. The resin material or resin layer obtained using these two-dimensionally randomly dispersed discontinuous fibers is substantially isotropic, without anisotropy within the plane.

[0057] The degree of two-dimensional random orientation is evaluated by determining the ratio of the tensile moduli in two mutually orthogonal directions. If the ratio (Eδ) obtained by dividing the larger of the measured tensile moduli in any direction of the resin material or resin layer, and in a direction orthogonal thereto, by the smaller, is 5 or less, more preferably 2 or less, and even more preferably 1.5 or less, then the reinforcing fibers can be evaluated as being dispersed randomly in two dimensions.

[0058] If the resin contained in the resin layer 103 is a thermoplastic resin and the resin layer 103 is three-dimensionally shaped including a curved surface, a good method for evaluating the two-dimensional random dispersion in the in-plane direction is to heat the resin layer 103 above its softening temperature to return it to a flat plate shape and then solidify it. After that, by cutting out a test piece and determining the tensile modulus, the random dispersion state in the two-dimensional direction can be confirmed.

[0059] [Modification] 1. Top surface and vertical surface The laminate of the present invention may have a top surface and a vertical surface. Specifically, it is preferable to have at least one planar surface having at least one thickness (plate thickness), and the cross-sectional shape may be T-shaped, L-shaped, U-shaped, hat-shaped (sometimes called a hat shape), or a three-dimensional shape including these, and it may also have an uneven shape (e.g., ribs, bosses). It is preferable that the structure manufactured by the laminate of this modification has a shape that includes a portion with a hat-shaped cross-section.

[0060] Figure 5 is a schematic cross-sectional view showing a laminate 501 according to this modified example. As shown in Figure 5, the laminate 501 has a metal layer 502 and a resin layer 503. The laminate in Figure 5 has a top surface portion 504 and a vertical surface portion 505, and the top surface portion 504 and the vertical surface portion 505 are connected to form a corner portion 506. The resin layer 503 preferably contains reinforcing fibers and resin. In Figure 5, the hole 507 is provided in the top surface portion 504, but the hole 507 may also be provided in the vertical surface portion 505.

[0061] When creating a laminated body 501 with a hat-shaped cross-section, having a top surface 504 and vertical surfaces 505 surrounding the top surface 504, using a metal plate, the vertical surfaces 505 become slightly thinner than the top surface 504 due to being stretched by the molding die. The thickness of the metal layer can be measured using the average thickness of 10 points.

[0062] 2. The perforated laminate 501 has a top surface portion 504 and a vertical surface portion 505, and it is preferable that the metal layer of the top surface portion 504 has at least one hole 507. Immediately after the hole 507 is made in the metal plate as a material, the bend portion 508 does not take on a fishhook shape, but tends to take on a shape closer to an L. When the fishhook-shaped bend portion 508 is formed by pressing the resin material and the metal plate together after the hole 507 has been made in the metal plate, the bend portion 508 can be easily formed by designing the hole 507 to be located in the top surface portion 504. Although the present invention does not negate the possibility of making a hole in the vertical surface portion 505, the top surface portion 504 is more suitable than the vertical surface portion 505 for forming a fishhook-shaped bend portion 508 when press-molding the laminate 501 with a hat-shaped cross-section.

[0063] [Laminate: Battery Tray and Battery Cover] A vehicle structure may be created from the laminate 501 of this modified example. A specific example of a vehicle structure is the components of a battery box. The components of the battery box are preferably located in the lower part of the vehicle body. Figure 4 is an exploded perspective view of a battery box 401 using the laminate 501 of this modified example. The battery box 401 comprises a battery cover 402, a battery 403, a temperature control system (cooling mechanism) 404, a battery tray 405, a reinforcing frame 406, and an energy absorbing member 407. The laminate of this embodiment can be used for the battery cover 402 and the battery tray 405. The battery 403 is housed in the battery box 401 which comprises the battery tray 405 and the battery cover 402.

[0064] [Battery Box and Metal Layer as Shielding Layer] Preferably, the metal layer 502 is a shielding layer that shields at least one of an electric field or a magnetic field. The following describes the case where the components of the battery box are used as a vehicle structure. The battery tray 405 is for the vehicle drive and is for mounting the battery 403 for vehicle drive. The battery cover 402 covers the battery 403. In order to shield electromagnetic waves generated from the battery 403, it is preferable that the battery box 401 is equipped with a shielding layer that shields an electric field or a magnetic field. By using the battery cover 402 and battery tray 405 made from the laminate 501 of this modified example, the metal layer 502 functions as a shielding layer. Therefore, electromagnetic waves radiated from the battery 403 can be shielded to prevent radiation and leakage to the outside, and sufficient electromagnetic shielding performance can be ensured for the battery box, making it possible to suppress adverse effects on the vehicle's control system and the human body due to electromagnetic waves, for example.

[0065] [Manufacturing Method: Integral Molding] 1. Overview The laminate 501 in this modified example is a laminate of a resin layer 503 and a metal layer 502. A laminate is formed by integrally molding a resin material and a metal plate. Integral molding means that these are molded continuously without seams, and are not formed by joining separate components. Such integral molding allows the molded body to be created in a single molding process, which can preferably be achieved by press molding. Because it is created by integral molding, separate parts can be processed as a single part, making it possible to reduce the unit cost of the part. In addition, the number of assembly steps is reduced, and the reduction in the number of parts makes it possible to reduce inventory costs.

[0066] 2. Conventional challenges that do not involve laminated construction When metal sheets are shaped separately without using integral molding, the irregularities of the mold (irregularities for shaping the metal sheet) tend to cause the metal sheets, especially at the corners, to tear. This is because the metal sheets (e.g., aluminum foil) stretch more than the elongation at break at the corners. Areas prone to tearing are shown as α in Figure 6A and γ in Figure 7A. In order to improve yield, conventionally, it was necessary to reinforce the areas shown as α in Figure 6A and γ in Figure 7A by applying cushioning or reinforcing materials such as masking tape to prevent tearing.

[0067] 3. Effects of integral molding (i) On the other hand, when the resin layer and the metal layer are integrally molded, the role of the cushioning material can be replaced by the resin material. This is a synergistic effect of integral molding of the metal plate and the resin material, and the corners of the mold do not come into contact with the metal plate, making it less likely to tear. For example, when molding only the metal plate 602 without laminating the resin material as shown in Figure 6A, it is necessary to provide a gentle curve at the corner α of the mold so that the corner α does not tear the metal plate 602. On the other hand, when the resin material 603 is placed in the lower mold and the metal plate 602 is laminated on top of the resin material 603 to integrally mold the metal plate 602 and the resin material 603 as shown in Figure 6B, the resin material 603 acts as a cushioning material, so the metal plate 602 is less likely to tear, and it is not necessary to provide a gentle curve at the corner β of the lower mold. The same can be said for Figures 7A and 7B. For example, if the metal plate 602 is molded using only the metal plate 602 without laminating resin material as shown in Figure 7A, a gentle curve must be provided at the corner γ of the upper mold to prevent it from tearing the metal plate 602. On the other hand, if the metal plate 602 is placed in the lower mold and the resin material 603 is laminated on top of the metal plate 602 to integrally mold the metal plate 602 and the resin material 603 as shown in Figure 7B, the resin material 603 acts as a buffer, making the metal plate 602 less likely to tear, and there is no need to provide a gentle curve at the corner δ of the upper mold.

[0068] 4. Effects of integral molding (ii) When the resin contained in the resin material is a thermoplastic resin and cold press molding is used, as shown in Figure 7B, if the metal plate 602 is placed in the lower mold and the resin material 603 is laminated so as to be in contact with the upper mold, the resin material 603 is not cooled to the mold temperature until just before it comes into contact with the upper mold. Therefore, it becomes easier to impart ribs and bosses to the resin material 603, and the design quality is also improved.

[0069] 5. Effects of integral molding (iii) The metal layer 502 is embedded in the resin layer 503, and it is preferable that the surface of the resin layer 503 and the surface of the metal layer 502 are aligned. In this case, there is no step between the surface of the resin layer 503 and the surface of the metal layer 502, resulting in a flat shape. The portion of the metal layer 502 that is embedded in the resin layer 503 may be the top surface 504 or the vertical surface 505 of the laminate 501. Since the end of the metal layer 502 is embedded in the resin of the resin layer 503 during integral molding, chipping of the end of the metal layer 502 can also be reduced. A part of the metal layer 502 may be embedded in the resin layer 503, or most of the metal layer 502 may be embedded in the resin layer 503.

[0070] [Manufacturing Method: Press Molding] 1. Overview The laminate of the present invention is preferably manufactured by laminating a resin material that will become a resin layer 503 and a metal plate that will become a metal layer 502, and then press molding them using upper and lower molding dies. More specifically, when the resin material is a thermoplastic resin, the resin material and the metal plate are heated, the heated resin material and the metal plate are stacked on top of each other, and the laminate is manufactured by pressing them simultaneously in a molding die to form an integrally molded body.

[0071] The present invention does not have particular limitations on the method for manufacturing the laminate, but it is preferable to laminate a resin material that will become the resin layer and a metal plate that will become the metal layer, press-form them using an upper mold and a lower mold, and manufacture the laminate through steps 101 to 301. Step 101: A burred hole is made in the metal plate so as to leave a burr that will become the bend portion 508. Step 201: With the burr facing the resin material, the metal plate and the resin material are placed into the lower mold. Step 301: The upper mold is closed and the metal plate and the resin material are integrally molded.

[0072] 2. When placing the metal plate and resin material into the mold, there are no particular restrictions on how the metal plate and resin material are stacked, but it is best to stack them when they are roughly the same size. If you want to partially shield the electric field, you can make the metal plate smaller and place it in a specific area.

[0073] 3. Lamination Order of Resin Material and Metal Plate There are no particular limitations on the lamination order of resin material and metal plate, but when the resin material is a thermoplastic resin and cold press molding is performed, laminating the resin material so that it is in contact with the upper mold improves the design of the resin layer and makes it easier to mold complex uneven shapes (ribs, bosses, etc.). This is because the resin material (which is relatively hot) is not cooled by the upper mold (which is relatively cold) until just before the molding pressure is applied. When the resin material is laminated so that it is in contact with the upper mold, the metal plate is in contact with the lower mold, so the resin material is not cooled by the lower mold (which is relatively cold), and it is easier to transfer the mirror surface of the upper mold.

[0074] From the perspective of the corners of the mold, if you want to integrally mold the corner β of the lower mold in Figure 6B while keeping it relatively sharp rather than having a gentle curve, you can laminate the resin material and metal plate so that the resin material is in contact with the lower mold. Conversely, if you want to integrally mold the corner δ of the upper mold in Figure 7B while keeping it relatively sharp rather than having a gentle curve, you can laminate the resin and metal plate so that the resin material is in contact with the upper mold.

[0075] 4. Hot Press Molding and Cold Press Molding In the present invention, it is preferable to press mold the metal sheet to form a metal layer and the resin material (preferably a resin material containing reinforcing fibers) to form a resin layer (preferably a resin layer containing reinforcing fibers). As the press molding method (sometimes called compression molding) in the present invention, molding methods such as hot press molding and cold press molding can be used.

[0076] 4.1 When using a thermoplastic resin as the resin material for cold press molding, cold press molding is preferred. In the cold press molding method, for example, a resin material heated to a first predetermined temperature and a metal plate are placed in a mold set to a second predetermined temperature, and then pressurized and cooled. The metal plate does not necessarily need to be heated, but in some cases it is better to heat it to improve the adhesion strength with the resin material. Specifically, if the thermoplastic resin contained in the resin material is crystalline, the first predetermined temperature is above the melting point, and the second predetermined temperature is below the melting point. If the thermoplastic resin is amorphous, the first predetermined temperature is above the glass transition temperature, and the second predetermined temperature is below the glass transition temperature. That is, the cold press method includes at least the following steps A-1) to A-2). Step A-1) A step of heating the thermoplastic resin to a temperature above the melting point and below the decomposition temperature if it is crystalline, or above the glass transition temperature and below the decomposition temperature if it is amorphous. Step A-2) A step in which the resin heated in step A-1) and the metal plate are placed in a mold whose temperature is controlled to be below the melting point if the thermoplastic resin is crystalline, or below the glass transition temperature if it is amorphous, and then pressurized.

[0077] By performing these steps, the molding of the resin material and metal plate can be completed (a laminate can be manufactured). The above steps must be performed in the order shown above, but other steps may be included between each step. Other steps include, for example, a forming step before step A-2), in which the resin material is pre-formed to the shape of the cavity of the mold using a different forming die than the mold used in step A-2). The shape of at least one of the resin material or the metal plate may be a shape developed from the three-dimensional shape of the laminate to be manufactured by reverse molding analysis using a computer.

[0078] 4.2 Hot Press Molding The hot press molding method involves, for example, placing a resin material into a mold, increasing the temperature of the mold to a first predetermined temperature while applying pressure, and then cooling the mold to a second predetermined temperature. The metal plate does not necessarily need to be heated, but heating it may be beneficial to improve the adhesion strength with the resin material. Specifically, if the thermoplastic resin constituting the resin material is crystalline, the first predetermined temperature is above the melting point, and the second predetermined temperature is below the melting point. If the thermoplastic resin contained in the resin material is amorphous, the first predetermined temperature is above the glass transition temperature, and the second predetermined temperature is below the glass transition temperature. Hot press molding preferably includes at least the following steps B-1) to B-4). B-1) A step of placing the resin material and the metal plate in the mold (lower mold). B-2) A step (first pressing step) in which the mold is heated and pressurized to a temperature above the melting point of the thermoplastic resin but below the thermal decomposition temperature if the thermoplastic resin is crystalline, or to a temperature above the glass transition temperature of the thermoplastic resin but below the thermal decomposition temperature if the thermoplastic resin is amorphous. B-3) A step (second pressing step) in which the mold is pressurized in one or more stages, such that the pressure in the final stage is between 1.2 and 100 times the pressure in the first pressing step. B-4) A step in which the mold temperature is adjusted to be below the melting point if the thermoplastic resin is crystalline, or below the glass transition temperature if the thermoplastic resin is amorphous. By performing these steps, a laminate can be created.

[0079] 5. Common aspects of cold press molding and hot press molding Steps A-2) and B-3) are steps in which pressure is applied to the resin material and metal plate to obtain a resin layer of the desired shape. There are no particular limitations on the molding pressure at this time, but it is preferable to keep it as low as possible within the range in which the desired structural shape can be obtained. Specifically, it is preferable that the molding pressure be less than 30 MPa relative to the projected area of ​​the mold cavity, more preferably 20 MPa or less, and even more preferably 10 MPa or less. When the molding pressure is less than 30 MPa, it is preferable because it does not require capital investment or maintenance costs for the press machine. Also, naturally, various steps may be inserted between the above steps during compression molding, for example, vacuum compression molding, which is compression molding while under vacuum, may be used.

[0080] 6. Flap and bend before and after press forming As mentioned above, in process 101, a metal plate is prepared and a burr hole 204 is provided so as to leave a flap 109. A burr hole is a hole made in the metal plate, which is the material of the laminate, and becomes a hole 104 in the metal layer when the laminate is formed.

[0081] There are no particular limitations on how the burred holes 204 are made, but punching is preferred over drilling. For example, using a punching tool with a sharp tip allows for the formation of burred holes 204 with crown-shaped burrs (barbs 109) as shown in Figure 8. This is because the material around the burred hole 204 is deformed by the punching tool.

[0082] Immediately after creating the burr-filled hole 204 in the metal plate material, the barb 109 does not take on a fishhook shape, but tends to be closer to an L-shape. It is preferable to create the fishhook-shaped bend portion 105 by pressing the resin material and the metal plate together after creating the burr-filled hole 204. There are no particular limitations on the molding pressure when creating the fishhook-shaped bend portion 105 from the barb 109; any pressure within the above-mentioned range is acceptable. Furthermore, it is preferable that the burr-filled hole 204 is below a certain size, as this prevents the bend portion 105 that bites into the resin material from becoming too large. The size of the burr-filled hole 204 is preferably 5 mm or less in diameter, and more preferably 3 mm or less in diameter.

[0083] 7. If the resin contained in the other resin layer 103 is a thermoplastic resin, the metal plate can be easily attached to the resin, either on top of or below the resin, by providing recesses in the resin material before molding for hooking the metal plate.

[0084] [Manufacturing Method: RTM Molding] 1. The laminate of the present invention can also be manufactured using RTM molding (Resin Transfer Molding). In recent years, the development of resins with fast curing speeds has progressed, and RTM molding has contributed to the mass production of large composite products. When the resin layer is a resin layer containing reinforcing fibers, for example, a woven fabric base material using reinforcing fibers such as glass fibers or carbon fibers is first placed in the mold in a dry fabric state without resin. At this time, a metal plate is placed on top of the woven fabric base material in a dry fabric state, and the mold is closed. After that, a thermosetting resin such as epoxy resin with good fluidity (easily permeates the fibers) is filled in. It is preferable to heat the mold once the resin has spread throughout to promote the curing of the epoxy resin. Even with this method, a laminate in which the resin layer and the metal layer are integrally molded can be created.

[0085] 2. Barbs and bends before and after RTM molding Even with RTM molding, it is preferable to adjust the molding die so that the barbs can be bent into a hook-shaped bend by the closing pressure of the mold.

[0086] 1. Materials: • Metal plate: Commercially available aluminum plate, UACJ A1050-O. • Polypropylene resin: Novatec PP BC03C (sometimes abbreviated as PP) manufactured by Nippon Polypropylene Co., Ltd. • Glass fiber E-glass RS240QR-483 manufactured by Nitto Boseki Co., Ltd. with a sizing agent attached. (Sometimes abbreviated as GF).

[0087] 2. Preparation of Resin Materials A resin material containing reinforcing fibers was used as the resin material. As the glass fiber, Nitto Boseki Co., Ltd.'s glass fiber E-glass RS240QR-483 was cut to a fiber length of 20 mm. Polypropylene resin (Novatec® PP BC03C manufactured by Nippon Polypropylene Co., Ltd.) was used as the resin.

[0088] A composite composition of glass fibers and polypropylene resin, in which glass fibers are oriented randomly in two dimensions, was prepared based on the method described in U.S. Patent No. 8,946,342. Specifically, a unidirectional, continuously moving permeable support having a suction mechanism at its bottom was installed. While suction was being applied by the suction mechanism, the glass fibers and polypropylene resin were blown onto the upper part of the permeable support using compressed air from a tapered tube positioned above the permeable support, thereby creating a composite product in which the glass fibers and polypropylene resin were mixed. The obtained composite composition was heated in a press device heated to 250°C at 2.0 MPa for 20 minutes to produce a resin material with an average thickness of 3 mm and dimensions of 300 mm x 300 mm.

[0089] [Example 1] 1. Drilling holes in an aluminum plate A 0.1 mm thick aluminum plate measuring 300 mm x 300 mm was prepared, and nine holes were drilled at 100 mm intervals (10,000 mm) using a 1 mm diameter drilling tool. ２ One burred hole was provided per piece. The burred holes were crown-shaped, and there were four burrs (barbs). 2. The integrally molded resin material was heated to 220°C using an infrared heater. Then, the resin material and the aluminum plate were laminated so that the resin material was in contact with the lower mold and the metal plate was in contact with the upper mold, and placed on the mold. The upper mold was lowered, and the resin material and metal plate were pressed simultaneously at a press pressure of 10 MPa (1 second from the start of pressurization to reach 10 MPa) for 1 minute to produce a laminate with a top surface, a vertical surface, and a corner formed by connecting the top surface and the vertical surface.

[0090] [Example 2-6] Diameter of burred holes and number of burred holes per 10,000 mm ２ The laminate was prepared in the same manner as in Example 1, except that the following was changed as shown in Table 1. [Examples 7-12] Thickness of metal plate, diameter of burr holes, and number of burr holes per 10,000 mm ２A laminate was prepared in the same manner as in Example 1, except that the specifications were changed as shown in Table 1. [Example 13] A laminate was prepared in the same manner as in Example 3, except that the thickness of the metal plate was changed as shown. [Example 14] A laminate was prepared in the same manner as in Example 9, except that the shape of the burred hole was made square. The results are shown in Table 2. Since the burred hole was square, the diameter of the burred hole was measured as the diameter of the largest inscribed circle.

[0091] [Comparative Example 1] A laminate was prepared in the same manner as in Example 7, without providing holes. [Comparative Example 2] A laminate was prepared in the same manner as in Example 9, without providing vents, and with burr-free, perfectly circular holes.

[0092] [Example 15] A laminate was prepared in the same manner as in Example 3, except that the thickness of the metal plate was 0.012 mm. [Example 16] A laminate was prepared in the same manner as in Example 3, except that the diameter of the burred hole was 0.1 mm. [Example 17] A laminate was prepared in the same manner as in Example 3, except that the thickness of the metal plate was 1.0 mm.

[0093] Evaluation (1) Electromagnetic wave shielding performance Test pieces (flat plates) measuring 150 mm x 150 mm were sampled from the laminates obtained in Examples 1 to 17 and Comparative Examples 1 to 2, and the field shielding performance for electromagnetic waves (frequency 1 MHz to 10 MHz, 10 MHz to 100 MHz, 100 MHz to 1 GHz) was measured using a network analyzer (Keysight Technologies) and a KEC method measuring device (JSE). A larger value indicates better field shielding performance.

[0094] Figures 10A to 10D show the evaluation of the electromagnetic shielding properties of the metal layers used in Examples 1 to 4. Figure 10B shows the evaluation of the electromagnetic shielding properties of the metal layer used in Example 2.

[0095] (2) Bonding Strength (90-degree Peel Strength) The laminates obtained in Examples 1, 3, 5, 7, 9, 11, 13-17 and Comparative Examples 1-2 were tested using an INSTRON 5982 type at a test speed of 5 mm / min, by pulling the metal layer against the resin layer at a 90-degree angle and over a length of 100 mm. In Examples 2, 4, 6, 8, 10, and 12, it was difficult to separate the resin layer and the metal layer, so the bonding strength was not measured. In 90-degree peel strength tests, the average value of the measured strength is generally used for evaluation, but in this case, in order to verify the effect of the holes fixing the metal layer and the resin layer, the maximum load measured during the test was used as the evaluation value. Good: Load 3.0 N or more Bad: Load less than 3.0 N

[0096] (3) Formability of metal sheets Commercially available aluminum sheets (UACJ A1050-150) used for the metal layers in Examples 1, 3, 5, 7, 9, 11, 13-17 and Comparative Examples 1-2 were prepared and cut to 200 mm x 200 mm. In Examples 2, 4, 6, 8, 10, and 12, the formability of the metal sheets was not evaluated because it was difficult to cut the metal sheets. The cut metal sheets were fitted into a frame, a semicircular pressing jig with a diameter of φ150 mm was set in the INSTRON 5982, and the sheets were pressed at a speed of 5 mm / min. The length of the metal sheets before and after pressing (before and after forming) was measured to evaluate how long it took for the metal sheets to break. Excellent: Fracture occurs at 150% or more of the original metal sheet length. Good: Fracture occurs at 105% or more but less than 150% of the original metal sheet length. Bad: Fracture occurs at less than 105% of the original metal sheet length.

[0097] (4) Tensile Test of Resin Layers Tensile test specimens were cut from the laminates of Examples 1, 3, 5, 7, 9, 11, 13-17 and Comparative Examples 1-2, with a hole placed in the center. The metal layer was removed from the cut tensile test specimens, and only the resin layer was isolated and subjected to a tensile test according to JIS K7164 (2005). In Examples 2, 4, 6, 8, 10, and 12, it was difficult to isolate only the resin layer, so a tensile test of the resin layer was not performed. The tensile strength of the resin layer in a state not integrally molded with the metal layer was used as the reference value, and the rate of decrease in tensile strength from the reference value was evaluated as follows: Good: Decrease in tensile strength is within 10% of the reference value Bad: Decrease in tensile strength is more than 10% of the reference value The results are shown in Tables 1 and 2.

[0098]

[0099]

[0100] The laminate of the present invention can be used in various applications, such as structural components for automobiles with complex shapes, where shielding from at least one of an electric field or a magnetic field is required.

Claims

1. A laminate comprising a resin layer and a metal layer, wherein the metal layer has a hole and a bent portion extending radially outward from the hole within the resin layer from the periphery of the hole.

2. The laminate according to claim 1, wherein the metal layer has a main body portion other than the bend portion, and when the laminate is viewed from the metal layer side and an orthographic projection is observed, the boundary between the main body portion and the hole is the periphery.

3. The laminate according to any one of claims 1 or 2, wherein the thickness of the metal layer is 0.03 mm or more and less than 1 mm, and the diameter of the largest inscribed circle of the hole is greater than 0.1 mm.

4. The laminate according to any one of claims 1 to 3, having a plurality of bends extending from the periphery of one of the holes.

5. The laminate according to any one of claims 1 to 4, wherein the laminate has a top surface portion and an upright surface portion, and the metal layer of the top surface portion has at least one of the holes.

6. The laminate according to any one of claims 1 to 5, wherein the bent portion is bent from the planar side of the laminate on the metal layer side toward the interior of the resin layer, and resin is present between the bent portion and the planar side on the metal layer side.

7. The laminate according to any one of claims 1 to 6, wherein the resin layer includes reinforcing fibers.

8. The laminate according to any one of claims 1 to 7, wherein the metal layer shields at least one of an electric field or a magnetic field.

9. The laminate according to any one of claims 1 to 8, further comprising a sealing material for blocking the holes.

10. A method for manufacturing a laminate according to any one of claims 1 to 8, comprising laminating a resin material to be the resin layer and a metal plate to be the metal layer, and press molding them using an upper mold and a lower mold, the method comprising the following steps 101 to 301. Step 101: A hole with a barb that will become the bend portion is made in the metal plate. Step 201: With the barb facing the resin material, the metal plate and the resin material are placed into the lower molding mold. Step 301: The upper molding mold is closed, the metal plate and the resin material are integrally molded, and the barb is bent radially outward from the hole to form the bend portion.

Images