Stacked structure and object detection structure

Abstract

To provide a laminated structure with an excellent appearance, and an object detecting structure comprising the same.SOLUTION: A laminated structure includes, in the following order: an outer member having a concave portion; a metal layer; and an inner member having a convex portion that is fitted with the concave portion to form a fitting portion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a laminated structure and an object detection structure.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2003-019765 discloses a metallic paint coating film in which a primer coating film and a metal layer are coated on a substrate in this order, and a clear coating film is coated on the metal layer, and the metallic paint coating film is used for automobile parts.

Summary of the Invention

Problems to be Solved by the Invention

[0003] By the way, in recent automobiles, the progress of safety devices has been remarkable. For example, the installation of an automatic collision avoidance system has become common. The automatic collision avoidance system automatically applies brakes using image data from an in-vehicle camera and relative distance information from an object by a millimeter-wave radar.

[0004] The transmitter and receiver of the millimeter-wave radar constituting the automatic collision avoidance system are preferably arranged at the center in the front of the automobile. Generally, an emblem of the automobile is arranged at the center in the front of the automobile. Therefore, it is desirable to arrange the transmitter and receiver of the millimeter-wave radar on the rear side of the emblem of the automobile. For example, the metallic paint coating film described in Japanese Patent Application Laid-Open No. 2003-019765 can be assumed to be used for the emblem of the automobile.

[0005] For automobile emblems and the like, a laminated structure in which a plurality of members such as an inner member and an outer member are laminated is used. Generally, the laminated structure is manufactured by insert molding for the purpose of eliminating gaps between members and reducing the transmission attenuation amount. However, the metal layer is damaged due to high temperature, high pressure, etc. in insert molding, and the deterioration of the appearance of the laminated structure becomes a problem, and there is a risk of impairing the designability of the product. In addition, in consideration of damage to the metal layer, a protective film or the like is provided on the inner member or the outer member, but there are problems in terms of manufacturing cost and productivity.

[0006] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a laminated structure excellent in appearance and an object detection structure including the same.

Means for Solving the Problems

[0007] The specific means for achieving the object are as follows. <1> A laminated structure including, in this order, an outer member having a concave portion, a metal layer, and an inner member having a convex portion that fits into the concave portion to form a fitting portion. <2> The laminated structure according to <1>, having a region surrounded by the fitting portion. <3> The laminated structure according to <1> or <2>, wherein the fitting portion is provided within 3 mm from the outer peripheral end of the laminated structure. <4> The laminated structure according to any one of <1> to <3>, wherein the metal layer includes a silver particle layer. <5> The laminated structure according to any one of <1> to <4>, wherein the metal layer has a sea-island structure in which metal particles are scattered in an island shape. <6> The laminated structure according to any one of <1> to <5>, used as an exterior member of a moving body. <7> An object detection structure including the laminated structure according to any one of <1> to <6> and a millimeter-wave radar that irradiates millimeter waves toward the laminated structure.

Advantages of the Invention

[0008] According to one aspect of the present disclosure, it is possible to provide a laminated structure excellent in appearance and an object detection structure including the same.

Brief Description of the Drawings

[0009]

Figure 1

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Mode for Carrying Out the Invention

[0010] Hereinafter, the embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values and their ranges, which do not limit the present disclosure.

[0011] In the numerical range indicated by "~" in the present disclosure, the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another stepwise described numerical range. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In the present disclosure, each component may contain a plurality of corresponding substances. In the present disclosure, the particles corresponding to each component may contain a plurality of types of particles. In the present disclosure, the terms "layer" or "film" include not only the case where the layer or film is formed over the entire region where it exists, but also the case where it is formed only in a part of the region when observing the region where the layer or film exists. In the present disclosure, the thickness of each layer refers to the arithmetic mean value obtained by preparing a test piece from a measurement object using a microtome or the like and measuring the thickness at any five locations with an electron microscope. In the present disclosure, "(meth)acrylic" is a term used in a concept that includes both acrylic and methacrylic. In the present disclosure, the term "step" includes not only a step independent from other steps, but also the step even if it cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0012] <Laminated structure> The laminated structure of the present disclosure includes, in this order, an outer member having a concave portion, a metal layer, and an inner member having a convex portion that fits into the concave portion to form a fitting portion.

[0013] The laminated structure of the present disclosure has excellent appearance. The reason is speculated as follows. The laminated structure of the present disclosure can be manufactured without using insert molding as described later. Therefore, damage to the metal layer in the manufacturing process is small, and it is speculated that the laminated structure including the metal layer has excellent appearance.

[0014] In each of the aforementioned members, the difference between the value of the relative permittivity of the member having the maximum relative permittivity and the value of the relative permittivity of the member having the minimum relative permittivity is preferably 1.0 or less, more preferably 0.5 or less, and even more preferably 0.3 or less from the viewpoint of reducing the transmission attenuation amount of millimeter waves. Note that the lower limit of the aforementioned difference is not particularly limited. In the present disclosure, the relative permittivity all means the value at 77 GHz.

[0015] Examples of the uses of the laminated structure of the present disclosure include, for example, exterior members, and more specifically, exterior members of moving bodies. Examples of moving bodies include automobiles such as four-wheel automobiles and two-wheel motorcycles, trains, trucks, ships, airplanes, bicycles, carts, trunks with casters, robots, drones, and electronic devices.

[0016] Examples of exterior members include automobile parts such as emblems, bumpers, and grills.

[0017] An example of the laminated structure of the present disclosure will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic top view showing an example of the laminated structure 10, and FIG. 2 is a schematic cross-sectional view taken along line A-A of the laminated structure 10 shown in FIG. 1. As shown in FIG. 2, the laminated structure 10 includes an outer member 1 having a concave portion 1A, a metal layer 2, and an inner member 3 having a convex portion 3A that fits into the concave portion 1A to form a fitting portion, in this order. Further, as indicated by the arrow in FIG. 2, millimeter waves pass through the laminated structure 10. In FIG. 1, the fitting portion 4 where the concave portion 1A and the convex portion 3A fit together is indicated by a dotted line. Further, in FIG. 2, the width of the convex and concave portions forming the fitting portion is indicated by the symbol l, and the height of the fitting portion is indicated by the symbol h.

[0018] As shown in FIG. 1, the laminated structure 10 preferably has a region (hereinafter also referred to as a specific region) surrounded by the outer peripheral end portion of the fitting portion 4. Although FIG. 1 shows a specific region along the shape of the laminated structure 10, it is not limited thereto and may not be along the shape. By the laminated structure having a specific region, the airtightness between the outer member and the inner member is improved, and there is a tendency to suppress the deterioration of the metal layer and the like in the specific region over time. The laminated structure 10 is not limited to the form shown in FIG. 1. As shown in FIG. 4, it may not have a specific region, and the fitting portion 24 may be arranged substantially parallel to the length direction or the width direction. In FIG. 4, the laminated structure is indicated by the reference numeral 30, the outer member is indicated by the reference numeral 21, and the fitting portion is indicated by the reference numeral 24.

[0019] The inner peripheral end portion of the fitting portion is preferably provided at a position within 3 mm from the outer peripheral end portion of the laminated structure. In the present disclosure, the outer peripheral end portion of the laminated structure means the end portion of either the outer member or the member with a smaller area among the outer members. In FIG. 3, the distance between the inner peripheral end portion of the fitting portion and the outer peripheral end portion of the laminated structure is indicated by d.

[0020] From the viewpoints of airtightness and the strength of the fitting portion, the width l of the convex portion and the concave portion forming the fitting portion is preferably 0.5 mm to 2.0 mm, and more preferably 1.0 mm to 1.5 mm. Also, from the viewpoints of airtightness and the strength of the fitting portion, the height h of the fitting portion is preferably 0.1 mm to 1.0 mm, and more preferably 0.3 mm to 0.8 mm.

[0021] Hereinafter, each member constituting the laminated structure of the present disclosure will be described.

[0022] (Outer member) The laminated structure of the present disclosure includes an outer member having a concave portion. The shape of the concave portion is not particularly limited, and as shown in FIG. 1, the cross section may be substantially rectangular.

[0023] The outer member can contain one type or two or more types of resin materials. Examples of the resin material contained in the outer member include thermosetting resins and thermoplastic resins.

[0024] Thermoplastic resins include polyethylene, polypropylene, polycarbonate (PC), polystyrene, polyvinyl chloride, vinyl polymers, polyesters, polyamides, acrylonitrile-butadiene-styrene copolymer resins (ABS resins), (meth)acrylic resins, acrylonitrile-ethylene-propylene-diene-styrene copolymer resins (AES resins), thermoplastic elastomers, and the like. Among them, the thermoplastic resin is preferably at least one resin selected from the group consisting of polycarbonate, ABS resin, (meth)acrylic resin, and AES resin. The (meth)acrylic resin preferably includes a polymethyl methacrylate (PMMA) resin.

[0025] Thermosetting resins include silicone resins, urethane resins, melamine resins, epoxy resins, phenolic resins, urea resins, and the like.

[0026] The resin material is preferably selected from the group consisting of PC, ABS resin, (meth)acrylic resin, and AES resin, and polycarbonate is particularly preferred. Among the resin materials, polypropylene has a low specific gravity, is easy to process, has high tensile strength, impact strength, and compression strength, and is also excellent in weather resistance and heat resistance. Among plastic materials, ABS resin is relatively easy to surface-treat, so it is easy to apply painting or the like after molding. It is excellent in chemical resistance and rigidity, and also has good impact resistance, heat resistance, and cold resistance. Among plastic materials, PC has high impact resistance, excellent weather resistance and heat resistance, and also has good transparency. In addition, polycarbonate is easy to process, is relatively light among plastic materials, and is a strong material.

[0027] Within the range that does not impair the characteristics of the laminated structure of the present disclosure, the outer member may contain additives such as inorganic particles, colorants, and ultraviolet absorbers.

[0028] The wavelength of the laser irradiated on the outer member varies depending on the laser irradiation device used, etc. For example, the laser transmittance of the outer member is preferably 30% or more, more preferably 60% or more, and even more preferably 90% or more. As the laser, for example, a laser having a wavelength of 800 nm to 1100 nm can be used.

[0029] The relative permittivity of the outer member at 77 GHz may be 2.5 to 3.0, may be 2.5 to 2.9, or may be 2.5 to 2.8.

[0030] From the viewpoint of radio wave permeability such as millimeter waves, the dielectric tangent of the outer member is preferably 0.010 or less. The lower limit of the dielectric tangent is not particularly limited.

[0031] The thickness of the outer member can be appropriately designed according to the use of the laminated structure. The shape of the outer member is not particularly limited either.

[0032] (Inner member) The laminated structure of the present disclosure includes a convex portion that fits into the concave portion of the outer member and includes an inner member facing the outer member. The shape of the convex portion in the fitting portion is not particularly limited, but preferably has a shape along the shape of the concave portion.

[0033] The inner member can contain one or more resin materials. Examples of the resin material contained in the inner member include thermosetting resins and thermoplastic resins. Since the thermosetting resin and the thermoplastic resin are as described above, the description is omitted here. Also, since the preferable resin materials are the same as those of the outer member, the description is omitted here.

[0034] Within a range that does not impair the characteristics of the laminated structure of the present disclosure, the inner member may contain additives such as inorganic particles, colorants, and ultraviolet absorbers.

[0035] The wavelength of the laser irradiated on the inner member varies depending on the laser irradiation device used, etc. For example, the laser transmittance of the inner member is preferably 30% or less, and more preferably 10% or less.

[0036] The relative permittivity of the inner member at 77 GHz may be 2.5 to 3.0, may be 2.5 to 2.9, or may be 2.5 to 2.8.

[0037] From the viewpoint of radio wave permeability such as millimeter waves, the dielectric loss tangent of the inner member is preferably 0.010 or less. The lower limit of the dielectric loss tangent is not particularly limited.

[0038] The thickness of the inner member can be appropriately designed according to the use of the laminated structure. The shape of the inner member is not particularly limited.

[0039] (Metal layer) The laminated structure of the present disclosure includes a metal layer between the outer member and the inner member.

[0040] The metal layer may be, for example, a metal particle layer containing metal particles, or a silver particle layer containing silver particles. Further, the metal particle layer may have an island structure in which the metal particles are scattered in an island shape.

[0041] The thickness of the metal layer is not particularly limited, and is preferably about 30 nm to 200 nm.

[0042] When the metal layer is a silver particle layer, when observing the cross section in the thickness direction of the silver particle layer, the ratio of silver particles in the silver particle layer is preferably 70% or less, and more preferably 60% to 65%. When the ratio of silver particles in the silver particle layer is 70% or less, the permeability of the millimeter wave radar tends to be further improved.

[0043] The ratio of silver particles in the silver particle layer refers to the value measured as follows. Take a transmission electron micrograph at a magnification of 300,000 for a cross-section in the thickness direction of the silver particle layer in the laminated structure. Determine a center line passing through the center in the thickness direction of the obtained silver particle layer in the electron micrograph. Next, obtain the length of the portion where the center line and the silver particles overlap. Define the percentage of the value obtained by dividing the length of the portion where the center line and the silver particles overlap by the total length of the center line as the ratio of the silver particles in the silver particle layer.

[0044] The surface resistivity of the silver particle layer is preferably 10 7 Ω / □ or more, and more preferably 5×10 7 Ω / □ or more. Thereby, it is likely that an appropriate gap is formed between the silver particles constituting the silver particle layer, and the laminated structure of the present disclosure tends to have excellent millimeter-wave permeability. The upper limit of the surface resistivity of the silver particle layer is not particularly limited. The surface resistivity of the silver particle layer refers to the value measured according to JIS K6911:2006.

[0045] (Undercoat layer) From the viewpoint of improving the adhesion between the outer member or the inner member and the silver particle layer, and from the viewpoint of forming a smooth surface on the outer member or the inner member, an undercoat layer may be provided between the outer member or the inner member and the silver particle layer.

[0046] For forming the undercoat layer, a fluororesin paint, a polyester resin paint, an epoxy resin paint, a melamine resin paint, a silicone resin paint, an acrylic silicone resin paint, an acrylic urethane resin paint, etc. may be used, and it is preferable to use an acrylic silicone resin paint or an acrylic urethane resin paint. The acrylic silicone resin paint is excellent in adhesion to the outer member or the inner member, has high gloss retention and color retention properties, and is also excellent in chemical resistance, oil resistance and water resistance. The acrylic urethane resin paint has a soft coating film, excellent adhesion, and is also excellent in durability, weather resistance and chemical resistance. These resin paints may be used alone or in combination of two or more.

[0047] The thickness of the undercoat layer is not particularly limited, and from the viewpoint of ensuring a smooth surface, it is preferably about 5 μm to 25 μm.

[0048] In order to enhance the adhesion between the undercoat layer and the outer member or the inner member, a primer layer may be provided between the undercoat layer and the outer member or the inner member.

[0049] (Topcoat layer) For the purpose of protecting the silver particle layer, a topcoat layer may be provided on the silver particle layer. The topcoat layer is a layer provided on the outermost surface of the ornament, and the silver particle layer is easily protected by the topcoat layer. The topcoat layer preferably has transparency that does not conceal the silver particle layer, and may be colorless clear (colorless and transparent) or colored color clear (colored and transparent).

[0050] For forming the topcoat layer, a resin paint can be used, and a thermosetting resin may also be used. Examples of the thermosetting resin include fluororesin paint, polyester resin paint, epoxy resin paint, melamine resin paint, silicone resin paint, acrylic silicone resin paint, acrylic urethane resin paint, etc. It is preferable to use acrylic silicone resin paint or acrylic urethane resin paint. Acrylic silicone resin paint is excellent in adhesion to the outer member or the inner member, gloss retention, color retention, chemical resistance, oil resistance, and water resistance. Acrylic urethane resin paint has a soft coating film, excellent adhesion, and is also excellent in durability, weather resistance, and chemical resistance. These resin paints may be used alone or in combination of two or more.

[0051] The thickness of the topcoat layer is not particularly limited, and it is preferably about 20 μm to 40 μm. When the thickness of the topcoat layer is 20 μm or more, the silver particle layer tends to be sufficiently protected, and when it is 40 μm or less, cracks, peeling, poor adhesion, etc. due to changes over time are less likely to occur.

[0052] The laminated structure of the present disclosure may include components other than the outer member, the inner member, and the metal layer. For example, other members may be provided on at least one of the outer side of the outer member and the outer side of the inner member.

[0053] (Method for manufacturing a laminated structure) The method for manufacturing the above-described laminated structure will be described with reference to FIGS. 4 to 6. The above-described laminated structure can be manufactured by a method for manufacturing a laminated structure including a step of preparing an outer member 31 having a concave portion 31A (FIG. 4), a step of preparing an inner member 32 having a convex portion 32A (FIG. 4), a step of inserting the convex portion 32A of the inner member 32 into the concave portion 31A of the outer member 31 (FIG. 5), and a step of heating and melting the convex portion 32A of the inner member 32 by a laser or the like and fitting it into the concave portion 31A of the outer member 31 to form a fitting portion 34 (FIG. 6). In FIG. 6, the arrow indicates a laser, and it is irradiated in the direction of the arrow. In the method for manufacturing the above-described laminated structure, a metal layer may be formed on the surface having the concave portion of the outer member or the surface having the convex portion of the inner member. FIG. 4 shows an outer member provided with a metal layer. Further, the method for manufacturing the laminated structure of the present disclosure may include a step of forming a metal layer on at least one surface of the outer member and the inner member.

[0054] Hereinafter, each step constituting the method for manufacturing the laminated structure will be described.

[0055] (Step of preparing an outer member and step of preparing an inner member) Commercially available outer members and inner members may be used, or they may be manufactured by a conventionally known method. For example, the outer member and the inner member can be manufactured by injection molding a composition containing the above-described resin material or the like.

[0056] The convex portion of the inner member preferably needs to be sized so that it can be inserted into the concave portion of the outer member. The ratio of the width l2 of the convex portion to the width l1 of the concave portion (l2 / l1) shown in FIG. 4 is preferably 0.9 or less, and more preferably 0.7 or less. From the viewpoints of airtightness and the strength of the fitting portion, l is preferably 0.7 mm to 2.0 mm, and more preferably 1.0 mm to 1.5 mm. From the viewpoints of airtightness and the strength of the fitting portion, l2 is preferably 0.5 mm to 1.8 mm, and more preferably 0.8 mm to 1.2 mm.

[0057] (Step of inserting the convex portion into the concave portion) The manufacturing method of the laminated structure includes a step of inserting the convex portion into the concave portion.

[0058] (Step of forming the fitting portion) The manufacturing method of the laminated structure includes a step of heating and melting the convex portion of the inner member and fitting it with the concave portion of the outer member to form a fitting portion. By heating and melting the convex portion, the convex portion is deformed into a shape that fits with the concave portion, and a fitting portion is formed.

[0059] The method of heating and melting the convex portion is not particularly limited, but it is preferably performed by laser irradiation. By performing the heating and melting of the convex portion by laser irradiation, the heating area can be controlled, and damage to the inner member around the heated and melted convex portion can be reduced. When the laser transmittance of the outer member is 90% or more and the laser transmittance of the inner member is 30% or less, it is preferable to perform laser irradiation from the surface on the outer member side.

[0060] (Step of forming the metal layer) The manufacturing method of the laminated structure can include a step of forming a metal layer on at least one surface of the outer member and the inner member. Also, in the above-described outer member preparation step and inner member preparation step, a metal layer may be formed on one surface of the prepared outer member and inner member. The metal layer may be a metal particle layer or a silver particle layer as described above.

[0061] The silver particle layer may be formed by a silver mirror reaction. Further, the silver particles contained in the silver particle layer may include silver particles deposited by the silver mirror reaction (deposited silver particles). Furthermore, the silver particle layer may exhibit an island structure in which silver particles are scattered in an island shape. The formation of the silver particle layer by the silver mirror reaction is carried out by applying two liquids, an aqueous solution of a water-soluble silver salt and a reducing agent aqueous solution containing a reducing agent and a strong alkali component, on the surface of the outer member, on the surface of the inner member, or on the surface of an undercoat layer described later (hereinafter, these surfaces may be collectively referred to as the "silver mirror reaction treatment surface"). As a result, an oxidation-reduction reaction occurs to generate silver particles, and a silver particle layer is formed.

[0062] (Step of forming an undercoat layer) The method for manufacturing the laminated structure may include a step of forming an undercoat layer. The method for forming the undercoat layer is not particularly limited, and it can be formed by applying the above-described paint or the like to the surface of the outer member or the like and drying it.

[0063] (Step of forming a topcoat layer) The method for manufacturing the laminated structure may include a step of forming a topcoat layer. The method for forming the topcoat layer is not particularly limited, and it can be formed by applying the above-described paint or the like to the surface of the metal layer and drying it.

[0064] <Object detection structure> The object detection structure of the present disclosure includes the aforementioned laminated structure of the present disclosure and a millimeter-wave radar that irradiates millimeter waves toward the laminated structure. Since the laminated structure of the present disclosure can reduce the transmission attenuation amount of millimeter waves, the object detection structure of the present disclosure is excellent in the transmission and reception performance of the millimeter-wave radar.

[0065] In addition, the laminated structure of the present disclosure may be combined with a radar that transmits and receives radio waves other than millimeter waves.

Example

[0066] Hereinafter, examples of the present disclosure will be described, but the present disclosure is not limited to the following examples.

[0067] <Example 1> (Preparation of outer member) A polycarbonate (PC) substrate (relative permittivity 2.8 and dielectric loss tangent 0.008 at 77 GHz) having an elliptical shape with a length of 119 mm and a width of 165 mm and a general part thickness of 4.2 mm shown in FIG. 7 was prepared as an outer member. Note that the general part refers to the part indicated by reference numeral H1 in FIG. 7. The outer member used in Example 1 has a part with a thinner plate thickness than the general part, and by forming a metal layer on the above part, when viewed from the surface opposite to the metal layer formation surface, the above part appears to be lifted. As shown in FIG. 7, the outer member 41 has a concave portion 41A along the outer peripheral end portion on one surface, and the width L1 of the concave portion is 1.2 mm. In addition, when the laser transmittance of the outer member at a wavelength of 1070 nm was measured, it was 92%.

[0068] (Preparation of inner member) A polycarbonate (PC) substrate (relative permittivity 2.8 and dielectric loss tangent 0.008 at 77 GHz) having an elliptical shape with a length of 119 mm and a width of 165 mm and a general part thickness of 2.5 mm shown in FIG. 8 was prepared as an inner member. Note that the general part refers to the part indicated by reference numeral H2 in FIG. 8, and is face-to-face with the general part of the outer part. The inner member used in Example 1 has a portion with a greater plate thickness than the general portion. As shown in FIG. 8, the inner member 43 has a convex portion 43A along the outer peripheral end on one surface, and the width L2 of the concave portion was 0.8 mm. Also, when measuring the laser transmittance of the inner member at a wavelength of 1070 nm, it was 0%.

[0069] (Formation of the metal layer) Using a two-fluid spray gun, two liquids, MSPS-Ag (trade name) and MSPS-Do (trade name) manufactured by Mitsubishi Paper Mills Limited, were applied inside the position where the concave portion of the outer member that forms the fitting portion with the inner member is provided, to form a silver particle layer 42 by a silver mirror reaction (see FIG. 9). Next, in order to remove the moisture on the surface of the silver particle layer, compressed air (air blow) was blown, and then it was dried in a drying oven set at 45°C for 30 minutes.

[0070] (Step of inserting the convex portion into the concave portion) As described above, the outer member with an undercoat layer and a metal layer formed on the surface having the concave portion and the inner member were faced each other, and the convex portion of the inner member was inserted into the concave portion of the outer member.

[0071] (Step of forming the fitting portion) Using VL-W1A00 manufactured by Panasonic, a laser with a wavelength of 1070 nm was irradiated from the surface of the outer member to the convex portion inserted into the concave portion, and while pressing the outer member toward the inner member side, the convex portion was heated and melted to be fitted with the concave portion, thereby forming a fitting portion and obtaining a laminated structure. In the laminated structure, the fitting portion is formed along the shape of the laminated structure (i.e., the elliptical shape) to form a specific region. Also, the distance d between the inner peripheral end of the fitting portion and the outer peripheral end of the laminated structure is 1.2 mm. When visually observing the appearance of the fitting portion, no damage due to laser irradiation was observed, and it had a good appearance.

[0072] <Comparative Example 1> A laminated structure was manufactured by insert molding. Specifically, it is as follows. In the same manner as in Example 1, an outer member having no concave portion and provided with a metal layer was prepared. The above outer member was placed in a mold, and heat-melted polycarbonate was injected into the mold to mold an inner member on the outer member, thereby obtaining a laminated structure. In the laminated structure, the inner member and the outer member were joined over the entire surface, and the appearance of the joined portion was good.

[0073] -Appearance evaluation- In the above Examples and Comparative Examples, laminated structures were manufactured, observed visually, and evaluated based on the following evaluation criteria. The results are shown in Table 1. (Evaluation results) A: It was confirmed that the laminated structure had a high gloss and an excellent appearance. B: The laminated structure was inferior in gloss, and there was room for improvement in its appearance.

[0074]

Table 1

[0075] As shown in Table 1, it was found that the laminated structure of Example 1 was superior in appearance compared to the laminated structure of Comparative Example 1.

[0076] The disclosure of Japanese Patent Application No. 2021-015926 filed on February 3, 2021 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually described as being incorporated by reference.

Claims

1. A laminated structure including, in this order, an outer member having a concave portion, a metal layer, and an inner member having a convex portion that fits into the concave portion to form a fitting portion. The laminated structure in which the fitting portion exists inside the center side rather than the outer peripheral end portion of the laminated structure, and only the fitting portion is fused.

2. The laminated structure according to claim 1, having a region surrounded by the fitting portion.

3. The laminated structure according to claim 1 or claim 2, in which the fitting portion is provided within 3 mm from the outer peripheral end portion of the laminated structure.

4. The laminated structure according to any one of claims 1 to 3, in which the metal layer includes a silver particle layer.

5. The laminated structure according to any one of claims 1 to 4, in which the metal layer has an island structure in which metal particles are scattered in an island shape.

6. The laminated structure according to any one of claims 1 to 5, used as an exterior member of a moving body.

7. The laminated structure according to any one of claims 1 to 6, and A millimeter-wave radar that irradiates millimeter waves toward the laminated structure. An object detection structure including the same.

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