Method for molding metal-resin composite material, metal-resin composite part and method for manufacturing the same

Abstract

To provide a method for molding a metal-resin composite material that can suppress springback.SOLUTION: In a method for molding a metal-resin composite material that has a laminated structure in which metal layers and resin layers are alternately laminated, and the laminated structure is asymmetrical, the metal-resin composite material is divided into parts (a) and (b) at half of whole layer thickness, and a total layer thickness of the resin layer in part (a) is Tra, the total layer thickness of the metal layer in part (a) is Tma, the total layer thickness of the resin layer in part (b) is Trb, and the total layer thickness of the metal layer in part (b) is Tmb. If Tma / Tra>Tmb / Trb, molding is performed with the part (a) side placed on a surface to which pressing force is applied. If Tma / Tra<Tmb / Trb, molding is performed by placing the part (b) side on the surface to which pressing force is applied. If Tma / Tra=Tmb / Trb, molding is performed by arranging the side on which the metal layer is located on the surface layer or the side close to the metal layer in the surface layer of the part (a) or (b) on the surface to which pressing force is applied.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a method for molding a metal-resin composite material, a metal-resin composite part, and a method for manufacturing the same. [Background technology]

[0002] In recent years, with growing interest in environmental issues, environmentally friendly vehicles equipped with secondary batteries, such as electric vehicles and hybrid vehicles, have become increasingly popular. Many of these environmentally friendly vehicles use a system in which direct current (DC) generated by the onboard secondary battery is converted to alternating current via an inverter, and the necessary power is then supplied to an AC motor to generate driving force. As a result, electromagnetic waves are generated due to the switching operation of the inverter. Since electromagnetic waves can interfere with on-board sensors, a countermeasure has been taken to shield electromagnetic waves by housing the inverter, or the inverter together with the battery and motor, in a housing made of aluminum plate material with a specified coating on the surface (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-285002 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, materials used for electromagnetic wave shielding have been required to be lightweight and to be able to be formed into complex shapes (particularly, to be able to be formed into molds with complex shapes). However, the aluminum sheet material described in Patent Document 1 cannot be said to fully meet these requirements. On the other hand, methods to meet the above requirements include using an Al vapor-deposited film in which aluminum is vapor-deposited on a resin film, and applying electroless plating to a material with good formability. However, although the method using an Al vapor-deposited film is inexpensive and has good formability, the vapor-deposited Al layer has a small thickness and lower conductivity than copper foil, etc., resulting in an insufficient electromagnetic wave shielding effect. In addition, the method of applying electroless plating to a material with good formability has a problem of being expensive and insufficient electromagnetic wave shielding effect because it is difficult to increase the thickness of the plated layer.

[0005] Therefore, the inventors focused on metal-resin composite materials in which metal layers and resin layers are laminated, and attempted to solve the above-mentioned requirements while ensuring the electromagnetic wave shielding effect by optimizing the configurations of the metal layers and resin layers. However, although metal-resin composite materials have a good electromagnetic wave shielding effect, they have the problem that springback is likely to occur in the bent portion (flange portion) during molding (for example, bulging or drawing), making it difficult to obtain the desired dimensional accuracy.

[0006] The embodiments of the present invention have been made to solve the above problems, and have an object to provide a method for molding a metal-resin composite material that can suppress springback. Another object of the embodiments of the present invention is to provide a metal-resin composite part with high dimensional accuracy and a method for manufacturing the same. [Means for solving the problem]

[0007] As a result of intensive research conducted by the inventors to solve the above problems, based on the knowledge that the layer structure of a metal-resin composite material and the direction in which a pressing force is applied during molding are related to the occurrence of springback, the inventors discovered that the springback suppression effect can be improved by molding a metal-resin composite material having a specific layer structure while applying a pressing force in a specific direction, and have thus completed an embodiment of the present invention.

[0008] That is, an embodiment of the present invention is a method for molding a metal-resin composite material having a laminated structure in which metal layers and resin layers are alternately laminated, and the laminated structure is asymmetric, comprising: The resin layer is a PET resin layer, Dividing the metal-resin composite material into part a and part b at a position half of the total layer thickness of the metal-resin composite material, and defining the total layer thickness of the resin layers existing in part a as Tra, the total layer thickness of the metal layers existing in part a as Tma, the total layer thickness of the resin layers existing in part b as Trb, and the total layer thickness of the metal layers existing in part b as Tmb. When Tma / Tra > Tmb / Trb, performing molding with part a disposed on the side where the pressing force is applied. When Tma / Tra < Tmb / Trb, performing molding with part b disposed on the side where the pressing force is applied. When Tma / Tra = Tmb / Trb, performing molding with either part a or part b, specifically, the side where the metal layer is located on the surface layer or the side closer to the metal layer, disposed on the side where the pressing force is applied. This is a method for molding a metal-resin composite material. Moreover, an embodiment of the present invention is a method for molding a metal-resin composite material having a laminated structure in which a metal layer and a resin layer are alternately laminated and the laminated structure is asymmetric, The metal-resin composite material has two or more of the metal layers, The metal-resin composite material is divided into part a and part b at a position half of the total layer thickness of the metal-resin composite material. Let the total layer thickness of the resin layer present in part a be Tra, the total layer thickness of the metal layer present in part a be Tma, the total layer thickness of the resin layer present in part b be Trb, and the total layer thickness of the metal layer present in part b be Tmb. When Tma / Tra > Tmb / Trb, perform molding with part a arranged on the surface to which the pressing force is applied. When Tma / Tra < Tmb / Trb, perform molding with part b arranged on the surface to which the pressing force is applied. When Tma / Tra = Tmb / Trb, perform molding with the side where the metal layer is located in the surface layer or the side close to the metal layer in part a or part b arranged on the surface to which the pressing force is applied. This is a method for molding a metal-resin composite material.

[0009] In addition, an embodiment of the present invention is a method for manufacturing a metal-resin composite component, which includes the above method for molding a metal-resin composite material. [[ID=_{27}]]

[0010] Furthermore, an embodiment of the present invention is a metal-resin composite component formed from a metal-resin composite material having a laminated structure in which metal layers and resin layers are alternately laminated, and the laminated structure is asymmetric, comprising: The resin layer is a PET resin layer, Divide it into part a and part b at the position of half of the total layer thickness of the metal resin composite material, and define the total layer thickness of the resin layer existing in part a as Tra, the total layer thickness of the metal layer existing in part a as Tma, the total layer thickness of the resin layer existing in part b as Trb, and the total layer thickness of the metal layer existing in part b as Tmb. When Tma / Tra > Tmb / Trb, part a is arranged on the surface to which the pressing force is applied. When Tma / Tra < Tmb / Trb, part b is arranged on the surface to which the pressing force is applied. When Tma / Tra = Tmb / Trb, on the surface to which the pressing force is applied, the side where the metal layer is located on the surface layer or the side closer to the metal layer among part a or part b is arranged, which is a metal resin composite part. Moreover, an embodiment of the present invention is a metal-resin composite part formed from a metal-resin composite material having a laminated structure in which a metal layer and a resin layer are alternately laminated and the laminated structure is asymmetric. The metal-resin composite material has two or more of the metal layers, The metal-resin composite material is divided into part a and part b at a position half of the total layer thickness of the metal-resin composite material. Let the total layer thickness of the resin layer present in part a be Tra, the total layer thickness of the metal layer present in part a be Tma, the total layer thickness of the resin layer present in part b be Trb, and the total layer thickness of the metal layer present in part b be Tmb. When Tma / Tra > Tmb / Trb, part a is arranged on the surface to which the pressing force is applied. When Tma / Tra < Tmb / Trb, part b is arranged on the surface to which the pressing force is applied. When Tma / Tra = Tmb / Trb, the side where the metal layer is located in the surface layer or the side close to the metal layer in part a or part b is arranged on the surface to which the pressing force is applied. This is a metal-resin composite part.

Advantages of the Invention

[0011] According to the embodiment of the present invention, a molding method of a metal resin composite material capable of suppressing springback can be provided. Moreover, according to the embodiment of the present invention, a metal resin composite part with high dimensional accuracy and a manufacturing method thereof can be provided.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0013] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention should not be construed as being limited to these embodiments, and various modifications and improvements can be made based on the knowledge of those skilled in the art without departing from the gist of the present invention. The multiple components disclosed in the embodiments can be appropriately combined to form various inventions. For example, some components may be omitted from all the components shown in the embodiments, or components from different embodiments may be appropriately combined.

[0014] In the method for molding a metal resin composite material according to an embodiment of the present invention, molding is performed by applying a pressing force from a specific direction depending on the type of layered structure of the metal resin composite material. A metal-resin composite material has a laminated structure in which metal layers and resin layers are alternately laminated, and has an electromagnetic wave shielding effect, so it can be used as an electromagnetic wave shielding material.

[0015] The number of layers in the laminated structure of the metal-resin composite material is not particularly limited as long as it is 2 or more, but is preferably 2 to 15 layers, more preferably 2 to 10 layers, and even more preferably 2 to 8 layers. Examples of the laminated structure include a two-layer structure of metal layer / resin layer, a three-layer structure of resin layer / metal layer / resin layer or metal layer / resin layer / metal layer, and a four-layer structure of resin layer / metal layer / resin layer / metal layer or metal layer / resin layer / metal layer / resin layer. The laminate structure of a metal-resin composite material is asymmetric. When the number of layers of the metal-resin composite material is even, the laminate structure is asymmetric. On the other hand, when the number of layers of the metal-resin composite material is odd (excluding 1), the laminate structure can be asymmetric or symmetric. An example of a symmetric laminate structure is when the first and third layers of a three-layer structure have the same thickness. Another example of an asymmetric laminate structure is when the first and third layers of a three-layer structure have different thicknesses. In addition, the laminated structure of the metal resin composite material preferably has two or more metal layers. By adopting such a configuration, the reflection surface of electromagnetic waves increases, so that the electromagnetic wave shielding effect can be improved.

[0016] The molding method of the metal resin composite material according to the embodiment of the present invention is performed as follows. In the laminated structure of the metal resin composite material, it is divided into two parts, a part and a b part, at the position of half of the total layer thickness of the metal resin composite material. Then, let the total layer thickness of the resin layers existing in the a part be Tra, the total layer thickness of the metal layers existing in the a part be Tma, the total layer thickness of the resin layers existing in the b part be Trb, and the total layer thickness of the metal layers existing in the b part be Tmb. Then, according to each of the following cases (1) to (3), the application direction of the pressing force is determined and molding is performed. (1) When Tma / Tra > Tmb / Trb, molding is performed by arranging the a part side on the surface to which the pressing force is applied. (2) When Tma / Tra < Tmb / Trb, molding is performed by arranging the b part side on the surface to which the pressing force is applied. (3) When Tma / Tra = Tmb / Trb, molding is performed by arranging, on the surface to which the pressing force is applied, the side where the metal layer is located on the surface layer or the side close to the metal layer among the a part or the b part. By performing molding while applying the pressing force as described above, the occurrence of springback can be suppressed.

[0017] Here, a cross-sectional view of the metal resin composite material corresponding to the case of (1) is shown in FIG. 1. FIG. 1 is a cross-sectional view of a metal resin composite material having a two-layer structure of a metal layer 10 / resin layer 20. When the metal resin composite material is divided into an a part and a b part at the position of half of the total layer thickness, Tra, Tma, and Trb can be determined as shown in FIG. 1. In the metal resin composite material of FIG. 1, since it has a two-layer structure, Tmb is zero, but if it has a laminated structure of three or more layers, Tmb can be set to be greater than zero. Since the metal resin composite material of FIG. 1 satisfies the relationship of Tma / Tra > Tmb / Trb, molding is performed by arranging the a part side on the surface to which the pressing force F is applied.

[0018] Next, a cross-sectional view of the metal-resin composite material corresponding to the case of (2) is shown in FIG. 2. FIG. 2 is a cross-sectional view of a metal-resin composite material having a three-layer structure of metal layer 10 / resin layer 20 / metal layer 10. When the metal-resin composite material is divided into part a and part b at the position of half of the total layer thickness, Tra, Tma, Tmb, and Trb can be determined as shown in FIG. 2. In the metal-resin composite material of FIG. 2, the thicknesses of the two metal layers 10 are different, and the thickness of the metal layer 10 in part b is set to be larger than the thickness of the metal layer 10 in part a. Since the metal-resin composite material of FIG. 2 satisfies the relationship of Tma / Tra < Tmb / Trb, molding is performed by arranging the b part side on the surface to which the pressing force F is applied.

[0019] Next, a cross-sectional view of the metal-resin composite material corresponding to the case of (3) is shown in FIG. 3. FIG. 3 is a cross-sectional view of a metal-resin composite material having a four-layer structure of metal layer 10 / resin layer 20 / metal layer 10 / resin layer 20. When the metal-resin composite material is divided into part a and part b at the position of half of the total layer thickness, Tra, Tma, Tmb, and Trb can be determined as shown in FIG. 3. In the metal-resin composite material of FIG. 3, the thicknesses of the two metal layers 10 and the two resin layers 20 are the same, respectively. Since the metal-resin composite material of FIG. 3 satisfies the relationship of Tma / Tra = Tmb / Trb and the metal layer 10 is located on the surface layer of part a, molding is performed by arranging the a part side on the surface to which the pressing force F is applied.

[0020] The molding method of the metal-resin composite material is not particularly limited as long as it is a method capable of applying the pressing force F to a predetermined surface, and a method known in the art can be used. Examples of the molding method include drawing, bulging, bending, pneumatic molding, etc. Among these, drawing, which has good processability for complex shapes, is preferred. When the molding method is drawing, the pressing force F is applied by a punch. Here, as an example, a method of applying a pressing force F in drawing will be described with reference to FIG. 4. When the surface to which the pressing force F is applied is the part a side of the metal resin composite material, the part a side of the metal resin composite material is placed on the surface that comes into contact with the punch 30 that applies the pressing force F. Then, by pressing the punch 30 in the thickness direction of the metal resin composite material to form it, a molded body (metal resin composite part) having a predetermined shape can be obtained. Although not shown, the metal resin composite material is placed in a die, and the peripheral edge is fixed by a blank holder, and then formed by the punch 30. Furthermore, molding of the metal-resin composite material can be carried out at room temperature or in a warm state, but even when molding is carried out at room temperature, the occurrence of springback can be suppressed. The magnitude of the pressing force F is not particularly limited and may be adjusted appropriately depending on the molding method used, the thickness of the metal-resin composite material, and the like.

[0021] It is preferable that the metal resin composite material has a metal layer 10 disposed on the surface to which the pressing force F is applied. With this configuration, when the metal resin composite material is molded to produce an electromagnetic wave shielding housing, the inner surface of the electromagnetic wave shielding housing becomes the metal layer 10, making it easy to ground.

[0022] The material of the metal layer 10 is not particularly limited, and various metals can be used. Among them, metals with excellent conductivity can be used from the viewpoint of enhancing the electromagnetic wave shielding effect against AC magnetic fields and AC electric fields. Specifically, the conductivity of the metal used for the metal layer 10 is preferably 1.0×10 6 S / m (value at 20°C, same below) or more, preferably 10.0×10 6 S / m or more, more preferably 30.0 × 10 6 S / m or more, most preferably 50.0×10 6 S / m or more. Such highly conductive metals have a conductivity of approximately 9.9 x 10 6 S / m of iron, conductivity is about 14.5 x 10 6 S / m of nickel, conductivity is approximately 39.6 x 10 6 S / m of aluminum, conductivity is approximately 58.0 x 106 S / m of copper, conductivity is approximately 61.4 x 10 6 Examples of suitable metals include silver with a conductivity of 0.15 S / m. Among these, aluminum or copper is preferred in terms of practicality, taking into consideration both conductivity and cost. An alloy of the above-mentioned metals may also be used for the metal layer 10. When a plurality of metal layers 10 are present in the metal-resin composite material, the plurality of metal layers 10 may be the same or different.

[0023] The surface of the metal layer 10 may be formed with various surface treatment layers for the purpose of improving adhesion promotion, environmental resistance, heat resistance, rust prevention, and the like. For example, to improve the environmental resistance and heat resistance required when the metal surface is the outermost layer, an Au plating layer, an Ag plating layer, an Sn plating layer, a Ni plating layer, a Zn plating layer, an Sn alloy plating layer (such as an Sn-Ag layer, an Sn-Ni layer, or an Sn-Cu layer), a chromate treatment layer, or the like can be formed on the surface of the metal layer 10. These treatment layers can be single or multiple. Among these treatment layers, an Sn plating layer or an Sn alloy plating layer is preferred from a cost perspective. Furthermore, in order to improve the adhesion between the metal layer 10 and the resin layer 20, a chromate-treated layer, a roughened layer, a Ni-plated layer, or the like may be formed on the surface of the metal layer 10. These treatment layers may be formed singly or in combination. Among these treatment layers, the roughened layer is preferred because it is highly effective in improving adhesion. Furthermore, in order to improve the electromagnetic wave shielding effect against DC magnetic fields, a layer with high relative magnetic permeability may be provided on the surface of the metal layer 10. Examples of the layer with high relative magnetic permeability include an Fe-Ni alloy plating layer and a Ni plating layer.

[0024] When a copper foil layer is used as the metal layer 10, it is preferable that the purity be high in order to improve the electromagnetic wave shielding effect. The purity of the copper foil used for the copper foil layer is preferably 99.5% by mass or more, and more preferably 99.8% by mass or more. The copper foil may be a rolled copper foil, an electrolytic copper foil, or a metallized copper foil, but a rolled copper foil is preferred because of its excellent flexibility and formability. When alloy elements are added to the copper foil to form a copper alloy foil, the total content of these elements and unavoidable impurities should be less than 0.5 mass%. In particular, it is preferable for the copper foil to contain a total of 200 to 2000 mass ppm of at least one element selected from the group consisting of Sn, Mn, Cr, Zn, Zr, Mg, Ni, Si, and Ag, because this improves elongation compared to pure copper foil of the same thickness.

[0025] The thickness of the metal layer 10 is not particularly limited, but is preferably 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, even more preferably 25 μm or more, and particularly preferably 30 μm or more per layer. By making the thickness of the metal layer 10 10 μm or more, it is possible to ensure a sufficient electromagnetic wave shielding effect. Furthermore, the thickness of the metal layer 10 is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 45 μm or less, and particularly preferably 40 μm or less per layer. By making the thickness of the metal layer 10 100 μm or less, it is possible to prevent a decrease in moldability. When a plurality of metal layers 10 are present in the metal-resin composite material, the thicknesses of the plurality of metal layers 10 may be the same or different.

[0026] The material of the resin layer 20 is not particularly limited, and various resins can be used. Examples of resins include PET (polyethylene terephthalate) resin, PEN (polyethylene naphthalate) resin, PI (polyimide) resin, PC (polycarbonate) resin, PE (polyethylene) resin, and PP (polypropylene) resin. Since these resins all have relatively large springback, when these resins are used and a molding method according to the present disclosure is applied, springback can be effectively suppressed. Furthermore, among the above-mentioned resins, inexpensive PET resin is preferred. When a plurality of resin layers 20 are present in the metal-resin composite material, the plurality of resin layers 20 may be the same or different.

[0027] The thickness of the resin layer 20 is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, and particularly preferably 40 μm or more per layer. By making the thickness of the resin layer 20 10 μm or more, the strength of the housing can be ensured when a housing is manufactured from the metal-resin composite material. Furthermore, the thickness of the resin layer 20 is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less per layer. Furthermore, by making the thickness of the resin layer 20 300 μm or less, deterioration in moldability can be suppressed. When a plurality of resin layers 20 are present in the metal-resin composite material, the thicknesses of the plurality of resin layers 20 may be the same or different, but are preferably the same.

[0028] The resin layer 20 can be formed using a resin film, but may also be formed by directly applying a resin material onto the metal layer 10 and curing it. When a resin film is used as the resin layer 20, the method for bonding the metal layer 10 and the resin film is not particularly limited, and any method known in the art can be used. For example, the metal layer 10 and the resin film may be bonded by thermocompression bonding, or the metal layer 10 and the resin film may be bonded using an adhesive. However, since resin films such as PET resin films are difficult to bond to the metal layer 10 by thermocompression bonding, it is preferable to bond them using an adhesive.

[0029] The adhesive is not particularly limited, and known adhesives such as thermoplastic adhesives and thermosetting adhesives can be used. Among them, thermosetting adhesives are chemically stable, and therefore can make the adhesive portion less susceptible to changes over time. Here, the thermoplastic adhesive refers to an adhesive whose main component is a thermoplastic resin that softens when heated and hardens when cooled. Examples of the thermoplastic resin include, but are not limited to, polyvinyl acetate, vinyl acetate-vinyl chloride copolymer, polyvinyl butyral, α-olefin resin, cellulose resin, acrylic resin, vinyl chloride resin, and polyvinyl acetal. These may be used alone or in combination of two or more. Furthermore, a thermosetting adhesive refers to an adhesive whose main component is a thermosetting resin that hardens when heated. Examples of thermosetting resins include, but are not limited to, urea resin, melamine resin, phenolic resin, resorcinol resin, epoxy resin, structural acrylic resin, polyester resin, and polyurethane resin. These may be used alone or in combination of two or more.

[0030] The total layer thickness of the metal-resin composite material is not particularly limited, but is preferably 110 to 800 μm, more preferably 150 to 700 μm, even more preferably 200 to 600 μm, and particularly preferably 250 to 500 μm. By making the total layer thickness of the metal-resin composite material 110 μm or more, the strength of the housing can be ensured when a housing is manufactured from the metal-resin composite material. Furthermore, by making the total layer thickness of the metal-resin composite material 800 μm or less, deterioration in moldability can be suppressed.

[0031] The method for molding a metal resin composite material according to an embodiment of the present invention can be used in a method for manufacturing a metal resin composite part. Therefore, the method for manufacturing a metal resin composite part includes the method for molding a metal resin composite material according to an embodiment of the present invention. Here, in this specification, the term "metal-resin composite part" refers to a part obtained by molding a metal-resin composite material into a predetermined shape. Examples of metal-resin composite parts include, but are not limited to, various parts that require electromagnetic wave shielding properties. Among these, the metal-resin composite part is preferably an electromagnetic wave shielding housing.

[0032] The metal resin composite part according to the embodiment of the present invention manufactured as described above has a laminated structure in which a metal layer 10 and a resin layer 20 are alternately laminated, and is formed from a metal resin composite material in which the laminated structure is asymmetric. Further, the metal resin composite part according to the embodiment of the present invention is divided into a part a and a part b at a position half of the total layer thickness of the metal resin composite material, and the total layer thickness of the resin layer 20 present in the part a is Tra, the total layer thickness of the metal layer 10 present in the part a is Tma, the total layer thickness of the resin layer 20 present in the part b is Trb, and the total layer thickness of the metal layer 10 present in the part b is Tmb. When set as, it has any one of the following structures (1) to (3). (1) When Tma / Tra > Tmb / Trb, the a - part side is arranged on the surface to which the pressing force F is applied. (2) When Tma / Tra < Tmb / Trb, the b - part side is arranged on the surface to which the pressing force F is applied. (3) When Tma / Tra = Tmb / Trb, on the surface to which the pressing force F is applied, the side where the metal layer 10 is located in the surface layer or the side closer to the metal layer 10 among the a - part or the b - part is arranged. By adopting the above - mentioned structure, the occurrence of springback during the molding of the metal resin composite material can be suppressed, so that the dimensional accuracy of the metal resin composite part can be improved.

[0033] Note that since the details of the metal resin composite material forming the metal resin composite part are as described above, the description is omitted.

Example

[0034] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited by these examples.

[0035] <Production of Metal Resin Composite Material A> A two-layer metal resin composite material A (hereinafter, this laminated structure may be abbreviated as "Cu / PET") was fabricated by laminating rolled copper foil (thickness 17 μm) with a roughened surface layer and a PET resin film (thickness 100 μm). A thermosetting adhesive was used to bond the rolled copper foil and the PET resin film. In this metal resin composite material A, the rolled copper foil side is designated as part a, and the PET resin film side is designated as part b.

[0036] <Preparation of metal-resin composite material B> A two-layer metal resin composite material B (hereinafter, this laminated structure may be abbreviated as "Cu / PET") was fabricated by laminating rolled copper foil (thickness 18 μm) with a roughened surface layer and a PET resin film (thickness 100 μm). A thermosetting adhesive was used to bond the rolled copper foil and the PET resin film. In this metal resin composite material B, the rolled copper foil side is designated as part a, and the PET resin film side is designated as part b.

[0037] <Preparation of metal-resin composite material C> A two-layer metal resin composite material C (hereinafter, this laminated structure may be abbreviated as "Cu / PET") was fabricated by laminating rolled copper foil (35 μm thick) with a roughened surface layer and a PET resin film (100 μm thick). A thermosetting adhesive was used to bond the rolled copper foil and the PET resin film. In this metal resin composite material C, the rolled copper foil side is designated as part a, and the PET resin film side is designated as part b.

[0038] <Preparation of metal-resin composite material D> A six-layer metal resin composite material D (hereinafter, this laminate structure may be abbreviated as "Cu / PET / Cu / PET / Cu / PET") was fabricated by alternately laminating three rolled copper foils (18 μm thick) with roughened layers on their surfaces and three PET resin films (100 μm thick). A thermosetting adhesive was used to bond the rolled copper foils and the PET resin films. In this metal resin composite material D, the rolled copper foil side exposed on the surface is referred to as "side a," and the PET resin film side exposed on the surface is referred to as "side b."

[0039] <Preparation of metal-resin composite material E> A six-layer metal-resin composite material E (hereinafter, this laminate structure may be abbreviated as "Cu / PET / Cu / PET / Cu / PET") was fabricated by alternately laminating three rolled copper foils (18 μm thick) with roughened layers on their surfaces and three PET resin films (50 μm thick). A thermosetting adhesive was used to bond the rolled copper foils and the PET resin films. In this metal-resin composite material E, the rolled copper foil side exposed on the surface is referred to as part a, and the PET resin film side exposed on the surface is referred to as part b.

[0040] <Preparation of metal-resin composite material F> A four-layer metal resin composite material F (hereinafter, this laminate structure may be abbreviated as "Cu / PET / Cu / PET") was fabricated by alternately laminating two rolled copper foils (35 μm thick) with roughened layers on their surfaces and two PET resin films (50 μm thick). A thermosetting adhesive was used to bond the rolled copper foils and the PET resin films. In this metal resin composite material F, the rolled copper foil side exposed on the surface is referred to as part a, and the PET resin film side exposed on the surface is referred to as part b.

[0041] Table 1 shows the values ​​of Tma / Tra and Tmb / Trb calculated from the laminate structures of the metal resin composite materials A to F produced as described above. Furthermore, the above metal resin composite materials A to F were subjected to the following evaluations.

[0042] <Moldability> The above metal resin composite materials A to F were drawn into a rectangular tube shape with a 90° flange. The drawing was performed twice for each of the metal resin composite materials A to F, with the side of part a and the side of part b positioned on the surface to which the pressing force was applied by the punch. In this evaluation, when comparing the results of the molding processability by the molding method using the same type of metal resin composite material, the molding method with a smaller springback in the flange portion is represented by ○, and the molding method with a larger springback is represented by ×. For example, as shown in Fig. 5, in the metal resin composite material A, the molded product (metal resin composite part) of Example 1 formed with the a-side disposed on the surface to which the pressing force is applied by the punch has a significantly smaller springback in the flange portion than the molded product of Comparative Example 1 formed with the b-side disposed on the surface to which the pressing force is applied. Therefore, the processing moldability of the molded product of Example 1 was evaluated as ○, and the processing moldability of the molded product of Comparative Example 1 was evaluated as ×, respectively.

[0043] <W bending test> Test pieces with a width of 10 mm × a length of 60 mm were cut out from the above metal resin composite materials A to F. For this test piece, at room temperature, a 90° W bending process was performed at a processing speed of 900 mm / min, a bending radius of 0 mm, a load of 2 kN, and a holding time of 2 seconds at the bottom dead center. In the bending portion (central portion) that becomes the peak of the W-bent test piece, the angle of the bent portion was measured, and the deviation from 90° (90° - measured angle), that is, the magnitude of the springback was determined. The above evaluation results are shown in Table 1.

[0044]

Table 1

[0045] As shown in Table 1, for the metal resin composite material A, Tma / Tra > Tmb / Trb. Therefore, compared with the case of molding with the b-side disposed on the surface to which the pressing force is applied (Comparative Example 1), the case of molding with the a-side disposed on the surface to which the pressing force is applied (Example 1) had better molding processability and results of the W bending test. For the metal resin composite material B, since Tma / Tra > Tmb / Trb, compared with the case of molding with the b-side disposed on the surface to which the pressing force is applied (Comparative Example 2), the case of molding with the a-side disposed on the surface to which the pressing force is applied (Example 2) had better molding processability and results of the W bending test. Since metal resin composite material C had Tma / Tra > Tmb / Trb, the molding processability and the results of the W-bend test were better when it was molded with part a placed on the surface to which the pressing force was applied (Example 3) than when it was molded with part b placed on the surface to which the pressing force was applied (Comparative Example 3).

[0046] Since metal resin composite material D had Tma / Tra > Tmb / Trb, the molding processability and results of the W-bend test were better when it was molded with part a placed on the surface to which the pressing force was applied (Example 4) than when it was molded with part b placed on the surface to which the pressing force was applied (Comparative Example 4). Since the metal-resin composite material E had Tma / Tra > Tmb / Trb, the molding processability and the results of the W-bend test were better when the metal-resin composite material E was molded with the a-side part on the pressing force application surface (Example 5) than when the metal-resin composite material E was molded with the b-side part on the pressing force application surface (Comparative Example 5). In the metal-resin composite material E, Tma / Tra = Tmb / Trb, and the metal layer was located on the surface of the a-section. Therefore, compared to the case where the b-section was placed on the pressing force application surface and molding was performed, the case where the a-section was placed on the pressing force application surface and molding was performed (Example 6) had better moldability and results in the W-bend test.

[0047] As can be seen from the above results, the present invention provides a method for molding a metal-resin composite material that can suppress springback. Also, the present invention provides a metal-resin composite part with high dimensional accuracy and a method for manufacturing the same. [Explanation of symbols]

[0048] 10 metal layer 20 Resin layer 30 punches

Claims

1. A method for molding a metal resin composite material having a laminated structure in which metal layers and resin layers are alternately laminated, wherein the laminated structure is asymmetric, comprising: the resin layer is a PET resin layer, The metal-resin composite material is divided into an a-section and a b-section at a position halfway through the entire layer thickness, and the total layer thickness of the resin layers present in the a-section is defined as Tra, the total layer thickness of the metal layers present in the a-section is defined as Tma, the total layer thickness of the resin layers present in the b-section is defined as Trb, and the total layer thickness of the metal layers present in the b-section is defined as Tmb, When Tma / Tra>Tmb / Trb, molding is performed by placing the part a side on the surface to which the pressing force is applied, When Tma / Tra<Tmb / Trb, molding is performed by placing the part b on the surface to which the pressing force is applied, A molding method for a metal-resin composite material, in which, when Tma / Tra = Tmb / Trb, the side to which a pressing force is applied is the side of the a part or the b part on which the metal layer is located as a surface layer or the side closest to the metal layer, and molding is performed.

2. A method for molding a metal resin composite material as described in claim 1, wherein the metal resin composite material has two or more metal layers.

3. A method for molding a metal-resin composite material having a laminate structure in which metal layers and resin layers are alternately laminated, the laminate structure being asymmetric, comprising: The metal-resin composite material has two or more of the metal layers, The metal-resin composite material is divided into an a-section and a b-section at a position halfway through the entire layer thickness, and the total layer thickness of the resin layers present in the a-section is defined as Tra, the total layer thickness of the metal layers present in the a-section is defined as Tma, the total layer thickness of the resin layers present in the b-section is defined as Trb, and the total layer thickness of the metal layers present in the b-section is defined as Tmb, When Tma / Tra>Tmb / Trb, molding is performed by placing the part a side on the surface to which the pressing force is applied, When Tma / Tra<Tmb / Trb, molding is performed by placing the part b on the surface to which the pressing force is applied, A molding method for a metal-resin composite material, in which, when Tma / Tra = Tmb / Trb, the side to which a pressing force is applied is the side of the a part or the b part on which the metal layer is located as a surface layer or the side closest to the metal layer, and molding is performed.

4. A method for molding a metal resin composite material described in any one of claims 1 to 3, wherein the molding is performed at room temperature.

5. The method for molding a metal-resin composite material according to any one of claims 1 to 4, wherein the molding is performed by drawing.

6. The method for molding a metal resin composite material according to any one of claims 1 to 5, wherein the metal layer is a copper foil layer.

7. The method for molding a metal resin composite material according to any one of claims 1 to 6, wherein the thickness of one of the metal layers is 10 to 50 µm.

8. The method for molding a metal resin composite material according to any one of claims 1 to 7, wherein the thickness of one of the resin layers is 20 to 200 µm.

9. The method for molding a metal resin composite material according to any one of claims 1 to 8, wherein the metal layer is disposed on a surface to which the pressing force is applied.

10. The method for molding a metal resin composite material according to any one of claims 1 to 9, wherein the metal layer and the resin layer are bonded together with an adhesive.

11. A method for producing a metal-resin composite part, comprising the method for molding a metal-resin composite material according to any one of claims 1 to 10.

12. A metal-resin composite part formed from a metal-resin composite material having a laminate structure in which metal layers and resin layers are alternately laminated, the laminate structure being asymmetric, the resin layer is a PET resin layer, The metal-resin composite material is divided into an a-section and a b-section at a position halfway through the entire layer thickness, and the total layer thickness of the resin layers present in the a-section is defined as Tra, the total layer thickness of the metal layers present in the a-section is defined as Tma, the total layer thickness of the resin layers present in the b-section is defined as Trb, and the total layer thickness of the metal layers present in the b-section is defined as Tmb, When Tma / Tra>Tmb / Trb, the a-part side is disposed on the surface to which the pressing force is applied, When Tma / Tra<Tmb / Trb, the portion b is disposed on the surface to which the pressing force is applied, A metal-resin composite part in which, when Tma / Tra = Tmb / Trb, the side of the a part or the b part on which the metal layer is located as a surface layer or the side closest to the metal layer is arranged on the surface to which the pressing force is applied.

13. A metal resin composite part as described in Claim 12, wherein the metal resin composite material has two or more of the metal layers.

14. A metal-resin composite part formed from a metal-resin composite material having a laminate structure in which metal layers and resin layers are alternately laminated, the laminate structure being asymmetric, The metal-resin composite material has two or more of the metal layers, The metal-resin composite material is divided into an a-section and a b-section at a position halfway through the entire layer thickness, and the total layer thickness of the resin layers present in the a-section is defined as Tra, the total layer thickness of the metal layers present in the a-section is defined as Tma, the total layer thickness of the resin layers present in the b-section is defined as Trb, and the total layer thickness of the metal layers present in the b-section is defined as Tmb, When Tma / Tra>Tmb / Trb, the a-part side is disposed on the surface to which the pressing force is applied, When Tma / Tra<Tmb / Trb, the portion b is disposed on the surface to which the pressing force is applied, A metal-resin composite part in which, when Tma / Tra = Tmb / Trb, the side of the a part or the b part on which the metal layer is located as a surface layer or the side closest to the metal layer is arranged on the surface to which the pressing force is applied.

15. The metal-resin composite part according to any one of claims 12 to 14, wherein the metal layer is a copper foil layer.

16. The metal resin composite part according to any one of claims 12 to 15, wherein a thickness of one of the metal layers is 10 to 50 µm.

17. The metal-resin composite part according to any one of claims 12 to 16, wherein one of the resin layers has a thickness of 20 to 200 µm.

18. The metal-resin composite part according to any one of claims 12 to 17, wherein the metal layer is disposed on a surface to which the pressing force is applied.

19. The metal-resin composite part according to any one of claims 12 to 18, wherein the metal layer and the resin layer are bonded together with an adhesive.

20. The metal-resin composite part according to any one of claims 12 to 19, which is an electromagnetic wave shielding housing.

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