Metallic decorative laminate and urethane adhesive

Abstract

The present invention provides a metallic decorative sheet, a metallic molded body, an injection molded body, a method for manufacturing a metallic decorative sheet, a method for manufacturing a metallic molded body, a method for manufacturing an injection molded body, and a urethane-based adhesive, all of which can satisfy hydrolysis resistance without impairing design and moldability, and can improve the appearance defects of metallic molded products caused by washout. [Solution] A metallic decorative sheet comprising, in order, a first polycarbonate film layer, a first adhesive layer, a metal layer holding film layer having a metal layer on at least one side, a second adhesive layer, and a second polycarbonate film layer, wherein the first adhesive layer and the second adhesive layer are cured products of a specific urethane-based adhesive.

Description

Technical Field

[0001] The present invention relates to a metallic decorative laminate, a metallic molded body, an injection molded body, a method for manufacturing a metallic decorative laminate, a method for manufacturing a metallic molded body, a method for manufacturing an injection molded body, and a urethane-based adhesive.

Background Art

[0002] In molding a resin molded body, a manufacturing method is known in which a metallic decorative laminate is inserted into a mold and molten resin is injected into the mold. The resin molded body manufactured by this manufacturing method can add a high-class metallic design simultaneously with molding. In addition, since it can achieve process reduction, low cost, weight reduction, etc., it is used for various applications such as interior and exterior parts of automobiles.

[0003] Examples of the metallic decorative laminate used for such a metallic molded body include those having a transparent or translucent surface film layer, an adhesive layer, a metallic layer holding laminate layer having a metallic layer on at least one side, an adhesive layer, and a base film layer in this order (Patent Document 1).

[0004] Also, a metallic molded body having a high-class feeling and a sharpness equivalent to that when using glass is known by injection molding a transparent polycarbonate resin as an injection molding resin on the surface side of a metallic decorative laminate (Patent Document 2). By using polycarbonate resin in this way, weight reduction and safety at the time of collision can be achieved simultaneously compared with the case of using glass.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present invention is to provide a metallic decorative laminate, a metallic molded article, an injection molded article, a method for manufacturing a metallic decorative laminate, a method for manufacturing a metallic molded article, a method for manufacturing an injection molded article, and a urethane adhesive that can improve the appearance defects of metallic molded articles caused by washout without impairing design and moldability, and that also satisfy hydrolysis resistance. [Means for solving the problem]

[0007] As a result of diligent research to solve the above-mentioned problems, the inventors provide the following [1] to [7]. [1] A metal layer laminate comprising a first polycarbonate layer, a first adhesive layer, a metal layer, a second adhesive layer, and a second polycarbonate layer in this order, wherein the first and second adhesive layers contain a reaction product of a polyester diol, a polycarbonate diol, and an aliphatic isocyanate, a carbodiimide, and a silane coupling agent having an epoxy group, and the content of the structure derived from the polyester diol in the first and second adhesive layers is 13.80 parts by mass or more and 14. A metallic decorative laminate comprising 25 parts by mass or less, wherein the content of the structure derived from the polycarbonate diol is 0.75 parts by mass or more and 1.20 parts by mass or less, the content of the structure derived from the aliphatic isocyanate is 3.20 parts by mass or more and 4.00 parts by mass or less, the content of the structure derived from the carbodiimide is 0.08 parts by mass or more and 0.20 parts by mass or less, and the content of the structure derived from the silane coupling agent is 0.50 parts by mass or more and 0.80 parts by mass or less. [2] A metallic molded body comprising a molded body of the metallic decorative laminate described in [1]. [3] An injection-molded article comprising an injection-molded resin layer on the surface of the first polycarbonate layer and / or the surface of the second polycarbonate layer of the metallic-looking molded article described in [2]. [4] A method for manufacturing a metallic decorative laminate according to [1], comprising: applying the urethane adhesive to the first polycarbonate layer and / or the metal layer laminate, drying the urethane adhesive, and then bonding the first polycarbonate layer and the metal layer laminate via the adhesive; and applying the urethane adhesive to the metal layer laminate and / or the second polycarbonate layer, drying the urethane adhesive, and then bonding the metal layer laminate and the second polycarbonate layer by bonding them together. [5] A method for manufacturing a metallic molded article, comprising a molding step of bringing a metallic decorative laminate described in [1], having a surface temperature of 150°C or more and 200°C or less, into close contact with a mold to obtain a molded article of a laminate having metallic decoration. [6] A method for manufacturing an injection-molded article, comprising an injection molding step of using an injection molding die to inject resin between the surface of the first polycarbonate layer and / or the surface of the second polycarbonate layer of the metallic-looking molded article obtained by the method for manufacturing a metallic-looking molded article described in [5] and the injection molding die to form a resin layer, thereby obtaining an injection-molded article in which the metallic-looking molded article and the resin layer are integrated. [7] A urethane adhesive containing a polyester diol, a polycarbonate diol, an aliphatic isocyanate, a carbodiimide, and a silane coupling agent having an epoxy group, wherein the content of the structure derived from the polyester diol is 13.80 parts by mass or more and 14.25 parts by mass or less, the content of the structure derived from the polycarbonate diol is 0.75 parts by mass or more and 1.20 parts by mass or less, the content of the structure derived from the aliphatic isocyanate is 3.20 parts by mass or more and 4.00 parts by mass or less, the content of the structure derived from the carbodiimide is 0.08 parts by mass or more and 0.20 parts by mass or less, and the content of the structure derived from the silane coupling agent is 0.50 parts by mass or more and 0.80 parts by mass or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a metallic decorative laminate, a metallic molded article, an injection molded article, a method for manufacturing a metallic decorative laminate, a method for manufacturing a metallic molded article, a method for manufacturing an injection molded article, and a urethane-based adhesive that can improve the appearance defects of metallic molded articles caused by washout without impairing design and moldability, and that also satisfy hydrolysis resistance. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view of a metallic decorative laminate (A) according to one embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view showing a metallic decorative laminate (B) according to one embodiment of the present invention. [Figure 3] These are a front view ((A)) and side views ((B), (C)) showing the dimensions of the injection-molded articles manufactured in the example. [Figure 4] This is a schematic diagram of an injection-molded product with washout (A) and an injection-molded product without washout (B). [Modes for carrying out the invention]

[0010] The aforementioned conventionally known metallic-looking molded products used the same polycarbonate resin as the injection resin as the surface film layer of the metallic-looking decorative laminate, in order to obtain adhesion with the injection resin. More specifically, the layer structure consisted of a transparent polycarbonate layer, an adhesive layer, a metal layer-holding laminate layer having a metal layer on at least one side, an adhesive layer, and a base film layer, in that order.

[0011] However, when using polycarbonate resin, the molding temperature becomes high, ranging from 300°C to 320°C. As a result, in the case of conventional metallic decorative laminates, the uncured adhesive inside the metallic decorative laminate melts (washout) near the injection gate during injection molding, and this melting results in a poor appearance of the metallic molded product.

[0012] Furthermore, metallic decorative laminates used for the interior and exterior of vehicles are increasingly required to have high resistance to hydrolysis (hereinafter referred to as hydrolysis resistance). Conventionally, a hydrolysis test was conducted to confirm that the required characteristics were met, in which the metallic decorative laminate was left standing for 10 days under conditions of 50°C and 95% RH relative humidity. After this hydrolysis test, it was required that no abnormalities such as peeling were observed in the adhesive layer within the metallic decorative laminate.

[0013] However, metallic decorative laminates are increasingly required to have even higher hydrolysis resistance. The hydrolysis resistance test, which is used to confirm that these required characteristics are met, has also had to be changed to one in which the metallic decorative laminate is left standing for 72 hours under conditions of 90°C and 95% RH relative humidity. It is required that no abnormalities such as delamination of the adhesive layer of the metallic decorative laminate are observed before and after the hydrolysis resistance test. Conventional metallic decorative laminates, when subjected to hydrolysis resistance tests under these conditions, undergo hydrolysis of the adhesive layer between the surface film layer and the metal layer-holding laminate layer within the metallic decorative laminate layer, causing delamination and preventing them from passing the hydrolysis resistance test. As described above, metallic decorative laminates are required to have higher hydrolysis resistance, and improvements to metallic decorative laminates were needed so that they could pass even the new hydrolysis resistance test that serves as an indicator of this higher resistance.

[0014] As described later, the metallic decorative laminate of this disclosure has a specific layer structure, and by further setting the first adhesive layer and the second adhesive layer to specific compositions, it is possible to obtain a metallic decorative laminate that can improve the appearance defects of metallic molded products due to washout without impairing design and moldability, and that satisfies hydrolysis resistance.

[0015] In addition, it is possible to provide intermediate laminates, multilayer laminates, decorative laminates, and metallic articles, which are composed of the metallic decorative laminate, as well as a method for manufacturing the intermediate laminate and a method for manufacturing the decorative laminate.

[0016] Hereinafter, the metallic decorative laminate, metallic molded body, injection molded body, method for manufacturing a metallic decorative laminate, method for manufacturing a metallic molded body, method for manufacturing an injection molded body, and urethane-based adhesive according to the present invention will be described. Note that the present invention is not limited to the following examples.

[0017] In the present disclosure, the thickness direction 100 means the lamination direction of the metallic decorative laminate or metallic article as illustrated in FIG. 1, and the width direction 110 is a direction different from the thickness direction and means a direction perpendicular to the longitudinal direction 120 of the metallic decorative laminate or metallic article. For example, when manufacturing the intermediate laminate described later by roll-to-roll, the longitudinal direction 120 corresponds to the flow direction (MD: machine direction), and the width direction 110 corresponds to TD (transverse direction) perpendicular to MD.

[0018] Hereinafter, embodiments of the present disclosure (hereinafter sometimes referred to as "the present embodiments") will be described. In the present disclosure, the numerical values related to "above", "below", "~", etc. in the description of the numerical range are numerical values that can be arbitrarily combined.

[0019] In addition, the defined provisions that are considered preferable can be arbitrarily adopted. That is, one defined provision that is considered preferable can be adopted in combination with one or more other defined provisions that are considered preferable. A combination of preferable ones can be said to be more preferable.

[0020] [Metallic Decorative Laminate] The metallic decorative laminate of the present embodiment is required to include, in this order, a metal layer laminate 1 including a first polycarbonate layer 10, a first adhesive layer 20, and a metal layer 30, a second adhesive layer 50, and a second polycarbonate layer 60 in this order. Details of each layer will be described later.

[0021] The metallic decorative laminate of this embodiment can be used to decorate resin parts and metal parts such as bumpers for automobiles (hereinafter also simply referred to as "articles") by film decoration methods such as insert molding and overlay molding. Furthermore, the multi-layer laminate including the metallic decorative laminate may be used to decorate the surface of an article via an adhesive layer or bonding layer, and can be used as a surface layer in the exterior of an automobile, such as pillars, door moldings, roof moldings, entire door surfaces, and entire roof surfaces. In addition, the metallic decorative laminate of this embodiment exhibits an excellent metallic design and has excellent hydrolysis resistance, making it suitable for outdoor use. Furthermore, it has excellent chemical resistance, making it suitable for use in decorating four-wheeled vehicles, two-wheeled vehicles, pumps, etc., where lubricating oil is used.

[0022] Furthermore, as will be described in more detail later, the metallic decorative laminate of this embodiment is preferable because it is easy to manufacture and therefore has excellent mass-producibility.

[0023] In this embodiment, the layer thickness of the metallic decorative laminate is preferably 200 μm or more, more preferably 230 μm or more, even more preferably 250 μm or more, and even more preferably 280 μm or more, in order to improve design and hydrolysis resistance. In order to improve moldability and appearance defects, it is preferably 500 μm or less, more preferably 400 μm or less, even more preferably 360 μm or less, and even more preferably 320 μm or less. In some cases, the metallic layer is irradiated with light from the first polycarbonate layer side of the metallic decorative laminate using a YAG laser or the like to burn off the metal layer and create the design. In such cases, it is preferable to reduce the layer thickness of the first polycarbonate layer, so it is preferable to set a low upper limit for the layer thickness of the metallic decorative laminate.

[0024] To balance the improvement of design, moldability, appearance defects, and hydrolysis resistance, the particle size is preferably 200 μm to 500 μm, more preferably 230 μm to 400 μm, even more preferably 250 μm to 360 μm, and even more preferably 280 μm to 320 μm.

[0025] In this disclosure, "design appeal" means the property that an article exhibits a metallic design when the metallic decorative laminate of this disclosure is used in the article.

[0026] In this disclosure, "formability" refers to the ease of manufacturing a metallic-looking article using the metallic-looking decorative laminate of this disclosure. Formability can be improved by increasing the layer thickness to suppress tearing during molding, or by decreasing the layer thickness to decorate even the fine details of the article. For example, it can be evaluated by the method described in the examples.

[0027] In this disclosure, "improvement of appearance defects" primarily refers to suppressing the melting (washout) of uncured adhesive within the metallic decorative laminate near the injection gate during injection molding to manufacture an injection-molded product using the metallic decorative laminate of this disclosure, which can result in a defective appearance of the metallic molded product.

[0028] The layer thickness of the metallic decorative laminate in this embodiment can be adjusted by the layer thickness of the constituent layers.

[0029] The metallic decorative laminate of this embodiment may include only a first polycarbonate layer, a first adhesive layer, a metal layer laminate including a metal layer, a second adhesive layer, and a second polycarbonate layer, but may also include other resin layers as described later.

[0030] When the metallic decorative laminate of this embodiment is installed on an article to form a metallic molded body as described later, it is preferable that the first polycarbonate layer is located on the article side, and the second polycarbonate layer is located on the outermost surface side of the metallic molded body.

[0031] <Laminated metal layers> The metal layer laminate 1 of this embodiment preferably includes a metal layer and a metal layer retaining layer that holds the metal layer. The metal layer may be on one side of the metal layer retaining layer or on both sides, but it is preferable to have the metal layer on only one side of the metal layer retaining layer in order to achieve aesthetic appeal while being easy to manufacture.

[0032] More specifically, the metallic decorative laminate (A)2 of this embodiment preferably includes, in order from the first polycarbonate layer 10, a first adhesive layer 20, a metal layer 30, a metal layer holding layer 40, a second adhesive layer 50, and a second polycarbonate layer 60, and may further include other layers as described later. The metallic decorative laminate (B)3 of this embodiment preferably includes, in order from the first polycarbonate layer 10, a first adhesive layer 20, a metal layer holding layer 40, a metal layer 30, a second adhesive layer 50, and a second polycarbonate layer 60, and may further include other layers as described later.

[0033] The metallic decorative laminate of this embodiment can be illustrated, for example, by the following laminate configuration from the article side. The symbol " / " represents the boundary between each layer. (1) First polycarbonate layer 10 / First adhesive layer 20 / Metal layer 30 / Metal layer holding layer 40 / Second adhesive layer 50 / Second polycarbonate layer 60 (2) First polycarbonate layer 10 / First adhesive layer 20 / Metal layer holding layer 40 / Metal layer 30 / Second adhesive layer 50 / Second polycarbonate layer 60 (3) First polycarbonate layer 10 / First adhesive layer 20 / Metal layer 30 / Metal layer holding layer 40 / Second adhesive layer 50 / Design layer / Second polycarbonate layer 60 (4) First polycarbonate layer 10 / First adhesive layer 20 / Metal layer holding layer 40 / Metal layer 30 / Second adhesive layer 50 / Design layer / Second polycarbonate layer 60 The aforementioned design layer is preferably constructed by laminating the design layer by printing or by laminating metal foil.

[0034] (Metal layer retention layer) As the metal layer retaining layer 40, an existing resin sheet can be used. For example, a sheet containing polycarbonate polyurethane and a silicone surfactant can be used. Furthermore, it is preferable that the mass ratio of polycarbonate polyurethane to silicone surfactant is 2.5 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of polycarbonate polyurethane.

[0035] Furthermore, the polycarbonate polyurethane may also contain a reaction product of isocyanate, a linear hydrocarbon polyol that does not contain cyclohexane, and a polyol that contains cyclohexane. Preferably, the amount of the linear hydrocarbon polyol that does not contain cyclohexane is 0.60 parts by mass or more and 0.80 parts by mass or less per 1.00 parts by mass of isocyanate, and the amount of the polyol that contains cyclohexane is 0.70 parts by mass or more and 0.90 parts by mass or less.

[0036] By using the aforementioned polycarbonate-based polyurethane as the metal layer holding layer, the tackiness can be reduced. In some cases, the metal layer holding layer may be wound up as an intermediate before forming the metal layer, and even in this case, the reduced tackiness makes it easier to wind up the metal layer holding layer.

[0037] The metal layer retaining layer can be formed by applying a mixture containing polycarbonate polyurethane and a silicone surfactant to the release resin layer and drying it. By adjusting the ratio of isocyanate, cyclohexane-free linear hydrocarbon polyol, and cyclohexane-containing polyol of the polycarbonate polyurethane to an appropriate range, even when the metal layer retaining layer is thinly applied to the release resin layer to a dry film thickness of approximately 10 μm to 25 μm, repelling is suppressed, and a film of uniform thickness can be formed.

[0038] Furthermore, a uniform metal layer can be formed by adjusting the ratio of isocyanate in the polycarbonate polyurethane, linear hydrocarbon polyols that do not contain cyclohexane, and polyols that contain cyclohexane within an appropriate range. That is, if the ratio of isocyanate in the polycarbonate polyurethane, linear hydrocarbon polyols that do not contain cyclohexane, and polyols that contain cyclohexane is outside the aforementioned range, blocking may occur in the formed metal layer holding layer. In other words, when the metal layer holding layer is unfolded before the metal layer is deposited, static electricity is generated, the voltage of the metal layer holding layer increases, and a uniform metal layer may not be formed, or discharge marks may be formed in the metal layer.

[0039] Furthermore, it is preferable that the 100% tensile stress of the metal layer holding layer at 100°C is 3N or less, and the elongation at break of the metal layer holding layer at 100°C is 210% or more.

[0040] Here, tensile stress and elongation at break can be measured according to JIS K 7127. Specifically, tensile stress can be measured as follows: First, a film with a width of 10 mm and a length of 150 mm for the metal layer holding layer is used as the sample for measurement, and two parallel gauge marks are made 50 mm apart in the center of the sample. Then, the stress when this sample is stretched to 100% (i.e., the distance between the gauge marks is stretched to 100 mm) is measured and taken as the 100% tensile stress. Elongation at break is the value that shows the length at break relative to the length before stretching when the film with the metal layer holding layer is stretched longitudinally until it breaks. For example, a film with a width of 10 mm and a length of 150 mm can be used as a sample for measuring elongation at break.

[0041] Because the tensile stress and elongation at break of the metal layer holding layer are within the aforementioned range, the formability of the metallic decorative laminate manufactured using such a metal layer laminate is good, and delamination due to the metal layer laminate attempting to return to its original shape after molding can be suppressed.

[0042] Furthermore, the metal layer retaining layer may also preferably contain carbodiimide, preferably in an amount of 10 to 25 parts by mass of carbodiimide per 100 parts by mass of polycarbonate polyurethane. This improves the hydrolysis resistance of the metallic decorative laminate produced using such a metal layer laminate, thereby suppressing clouding and other issues.

[0043] Furthermore, in the metal layer holding layer, cyclohexyl isocyanate can be used as the isocyanate, and 4,4'methylenebis(cyclohexyl isocyanate) can be suitably used. Also, as the linear hydrocarbon polyol that does not contain cyclohexane, n-pentanedimethanol carbonate and n-heptanedimethanol carbonate can be used, and n-hexanedimethanol carbonate can be suitably used. Also, as the polyol that contains cyclohexane, cyclohexanediethanol carbonate can be used, and cyclohexanedimethanol carbonate can be suitably used.

[0044] Furthermore, it is preferable that the metal layer holding layer has an average thickness of 10 μm or more and 25 μm or less, and that its thickness is within the range of average thickness - 0.5 μm or average thickness + 0.5 μm or less.

[0045] By setting the thickness of the metal layer holding layer within the aforementioned range, the winding length of the metal layer holding layer can be increased, thereby increasing the production volume per batch. Furthermore, by setting the thickness of the metal layer holding layer within the aforementioned range, the occurrence of defects such as wrinkles and breakage in subsequent processes using the metal layer holding layer can be suppressed, improving the handling of the metal layer laminate. In addition, by setting the thickness of the metal layer holding layer within the aforementioned range, the tensile stress of the metal layer holding layer can be sufficiently reduced, improving the moldability of the decorative sheet using the metal layer laminate.

[0046] Furthermore, it is preferable that the thickness of the metal layer holding layer is within the range of average thickness - 0.5 μm or more and average thickness + 0.5 μm or less. In other words, by forming the metal layer holding layer with a uniform thickness, a metal layer laminate with stable quality and a metallic decorative laminate with stable quality manufactured using the metal layer laminate can be obtained.

[0047] Furthermore, it is preferable that the metal layer holding layer has a total light transmittance of 90% or more and a haze of 1.3% or less. By setting the light transmittance and haze within these ranges, the transparency of the metallic decorative laminate manufactured using the metal layer laminate is increased, and the metallic decorative laminate can be sufficiently given a metallic design, thereby obtaining the desired design. The total light transmittance can be set to the desired level by appropriately adjusting the material and thickness of the metal layer holding layer.

[0048] The metal layer retaining layer described above can be formed, for example, using a polycarbonate-based polyurethane dispersion (aqueous polycarbonate-based polyurethane dispersion) obtained by dispersing polyurethane resin in an aqueous solvent such as water. As the polyurethane dispersion, for example, polyurethane dispersions UW5002, UW5502 (manufactured by Ube Industries, Ltd.), etc. can be used.

[0049] Furthermore, the metal layer retaining layer may use a single polyurethane resin, or it may use a mixture of two or more polyurethane resins having different structures. For example, polyurethane dispersions such as UW5002 and UW5502 (manufactured by Ube Industries) can be mixed and used so that the metal layer retaining layer has the aforementioned physical properties.

[0050] Furthermore, the metal layer retaining layer may be subjected to matte finish, etching, hairline finish, or the like to impart a desired design. The metal layer retaining layer may also contain pigments or dyes to obtain a desired color tone.

[0051] Furthermore, the metal layer retaining layer may also contain additives such as stabilizers, ultraviolet absorbers, lubricants, flame retardants, and antistatic agents, in addition to the materials mentioned above. (metal layer) The aforementioned metal layer is held in a metal layer holding layer, and by manufacturing a metallic decorative laminate using a metal layer laminate, a metallic design can be imparted to the metallic decorative laminate.

[0052] The metal layer may be a uniform layer, or it may be a layered structure in which metal island structures are continuously present. The sea structure becomes the first adhesive layer or the second adhesive layer. The metal layer is preferable because, having a sea-island structure in which metal particles are separated from each other and have gaps, it is possible to prevent whitening and maintain metallic luster even when deep drawing three-dimensional molding is performed.

[0053] The amount of metal per unit area and the thickness of the metal layer can be adjusted depending on the conditions during the manufacturing of the metal layer. Further details will be provided later.

[0054] The thickness of the metal layer is not particularly limited as long as the desired design can be achieved, but it is preferably 5 nm to 100 nm, more preferably 10 nm to 80 nm, even more preferably 20 nm to 70 nm, and even more preferably 40 nm to 60 nm. A metal layer thickness above the lower limit is preferable because it results in a uniform layer and produces an excellent metallic design. Furthermore, keeping the metal layer thickness below the upper limit is preferable because it allows for sufficient design quality while keeping manufacturing costs down.

[0055] Furthermore, the metallic-look decorative laminate exhibits its metallic design when ambient light is reflected by the metal layer. Therefore, the metallic design will not be visible when there is no ambient light, such as at night, or when ambient light is weak. For this reason, one method involves placing a backlight on the side of the metallic-look decorative laminate to reveal the design through transmitted light from the backlight. To achieve this effect, it is preferable to make the metal layer thin, preferably in the range of 5 nm to 50 nm.

[0056] Furthermore, the metals constituting the metal layer are not particularly limited as long as they produce the intended design, and can be appropriately selected according to the desired design characteristics. Preferably, the metals constituting the metal layer are a combination of one or more metals or alloys that can impart sufficient metallic luster to the metallic decorative laminate and have excellent malleability. Specifically, it is preferable to use one or more selected from the group consisting of aluminum, indium, chromium, zinc, gallium, nickel, tin, silver, gold, silicon, chromium, titanium, platinum, palladium, nickel, stainless steel, and Hastelloy®, and alloys thereof.

[0057] Furthermore, the metal layer can be formed, for example, by depositing the aforementioned metal onto a metal layer holding layer. Alternatively, the metal layer can be formed by methods such as sputtering or ion plating.

[0058] Furthermore, the width dimension of the metal layer laminate in this embodiment is not particularly limited and can be any width that can be manufactured industrially, for example, 1000 mm or more and 2000 mm or less is preferred. In addition, by using the polycarbonate-based polyurethane described above in the metal layer holding layer, it is possible to form a metal layer holding layer with a stable and uniform thickness, which is preferable for the industrial manufacture of the metal layer laminate.

[0059] For example, when transporting or storing a metal layer laminate as an intermediate for a metallic decorative laminate, a protective film may be further laminated on the metal layer side of the metal layer laminate to prevent dirt and scratches, and a release resin layer may be further laminated on the side of the metal layer holding layer opposite to the metal layer.

[0060] Furthermore, by using the polycarbonate-based polyurethane in the metal layer holding layer, a uniform metal layer holding layer can be formed. In addition, blocking of the metal layer holding layer can be suppressed by suppressing the generation of static electricity in the metal layer holding layer. As a result, defects such as discharge marks in the metal layer are suppressed, and a metal layer with a uniform thickness can be formed in the metal layer holding layer. Moreover, by manufacturing a metallic decorative laminate using such a metal layer laminate, a metallic decorative laminate with the same design quality as a conventional decorative sheet using modified polyethylene terephthalate can be obtained.

[0061] The metal layer laminate may be arranged such that the metal layer is laminated on the first adhesive layer side of the metal layer holding layer, as shown in the metallic decorative laminate A in Figure 1, or the metal layer is laminated on the second polycarbonate layer side of the metal layer holding layer, as shown in the metallic decorative laminate B in Figure 2.

[0062] <First polycarbonate layer> The first polycarbonate layer is the bottom layer (article side in the injection-molded product) of the metallic decorative laminate. Preferably, the first polycarbonate layer can withstand the temperature when decorating using the metallic decorative laminate. As described above, the metallic decorative laminate exhibits a metallic design due to the reflection of external light from the metal layer, so the requirements for transparency and color tone of the first polycarbonate layer, which is on the article side of the metal layer, are small. However, if a viewer observing the article recognizes its color, the transparency and color tone may be adjusted as appropriate.

[0063] Considering the impact on color tone and transparency, the raw materials for forming the first polycarbonate layer can be appropriately selected from polycarbonate resin depending on the application, taking into account factors such as heat resistance to molding temperatures, compatibility with injection molding resins in insert injection molding, and compatibility with extruded resins in extrusion lamination.

[0064] For example, when high transparency is required, a first polycarbonate layer made from polycarbonate resin, which has excellent transparency and high injection adhesion, can be used.

[0065] The thickness of the first polycarbonate layer can be a thickness typical for decorative sheets, but it is preferable to set it to be above the lower limit in order to suppress the occurrence of defects such as wrinkles when laminating with the metal layer laminate, and it is preferable to set it to be below the upper limit in order to suppress the fracture of the metallic decorative laminate during molding and to improve the moldability of the metallic decorative laminate, preferably 20 μm or more and 500 μm or less, more preferably 50 μm or more and 300 μm or less, even more preferably 80 μm or more and 200 μm or less, and even more preferably 100 μm or more and 150 μm or less.

[0066] <First adhesive layer> The aforementioned first adhesive layer is a layer that adheres the metal layer laminate to the first polycarbonate layer.

[0067] The first adhesive layer must contain a reaction product of a polyester diol, a polycarbonate diol, and an aliphatic isocyanate, a carbodiimide, and a silane coupling agent having an epoxy group. Each component will be described later.

[0068] For example, a first adhesive layer can be formed by applying the urethane-based adhesive described below to a metal layer laminate and / or a first polycarbonate layer, and then curing it. The urethane-based adhesive is a useful adhesive considering its transparency, adhesive properties, and heat resistance to withstand the temperatures during molding. As an indicator of transparency, for example, light transmittance and haze can be used.

[0069] The method for forming the first adhesive layer with a urethane-based adhesive is not particularly limited. For example, the first adhesive layer can be formed by applying an appropriate amount using known means such as a gravure coater, reverse coater, knife coater, or roll coater, and drying it as necessary.

[0070] Furthermore, the thickness of the first adhesive layer can be a typical thickness for a metallic decorative laminate. A thinner layer is preferable to improve moldability and appearance defects, a thicker layer is preferable to improve hydrolysis resistance, preferably 1 μm to 30 μm, more preferably 3 μm to 25 μm, even more preferably 5 μm to 20 μm, even more preferably 7 μm to 15 μm, and most preferably 8 μm to 12 μm. In some cases, the metallic decorative laminate is made to reveal its design by irradiating the metal layer with light from a YAG laser or the like from the first polycarbonate layer side to burn off the metal layer, and in such cases, it is preferable to make the thickness of the first polycarbonate layer thinner.

[0071] <Second adhesive layer> The aforementioned second adhesive layer is a layer that adheres the second polycarbonate layer to the metal layer laminate.

[0072] The second adhesive layer must contain a reaction product of a polyester diol, a polycarbonate diol, and an aliphatic isocyanate, a carbodiimide, and a silane coupling agent having an epoxy group. Each component will be described later.

[0073] For example, a second adhesive layer can be formed by applying a urethane-based adhesive, as described later, to the metal layer laminate and / or the second polycarbonate layer. Urethane-based adhesives are useful adhesives considering transparency, adhesion, and heat resistance to withstand molding temperatures. Transparency can be measured by indicators such as light transmittance and haze. The adhesive used for the second adhesive layer may be the same adhesive used for the first adhesive layer.

[0074] The method for forming the second adhesive layer with the adhesive is not particularly limited. For example, the second adhesive layer can be formed by applying an appropriate amount using known means such as a gravure coater, reverse coater, knife coater, or roll coater, and drying it as necessary.

[0075] Furthermore, the thickness of the second adhesive layer can be a typical thickness for a metallic decorative laminate. A thinner layer is preferable for improving moldability and appearance defects, while a thicker layer is preferable for improving hydrolysis resistance. A thickness of 1 μm to 30 μm is preferred, 3 μm to 25 μm is more preferred, 5 μm to 20 μm is even more preferred, 7 μm to 15 μm is even more preferred, and 8 μm to 12 μm is most preferable. The second adhesive layer may have the same thickness as the first adhesive layer.

[0076] The first and second adhesive layers are preferably cured products of a urethane-based adhesive. The first and second adhesive layers may also be formed by curing a urethane-based adhesive of the same composition. Furthermore, the first and second adhesive layers may be formed under the same conditions regarding the amount of urethane-based adhesive applied and the curing conditions.

[0077] <Second polycarbonate layer> The second polycarbonate layer is positioned as the uppermost layer of the metallic decorative laminate (on the side opposite the article in the injection-molded product, and on the viewer's side). Preferably, the second polycarbonate layer is transparent so that the observer can see the reflected light from the metal layer and can withstand the temperatures during the decorative process using the metallic decorative laminate. It is also preferable that it serves as a protective layer to protect the metal layer laminate.

[0078] The second polycarbonate layer may contain various dyes and pigments to adjust its transparency and color tone, and may also be dyed with dyes. Furthermore, the second polycarbonate layer may have a desired print applied to it beforehand. In this case, the print may be applied to the surface of the second polycarbonate layer that comes into contact with the outside, but it is preferable to print on the surface opposite to the surface that comes into contact with the outside, which is the surface that comes into contact with the second adhesive layer, as this can improve the durability of the print.

[0079] As the material for the second polycarbonate layer, a polycarbonate-based resin with excellent processability, heat resistance and moldability to molding temperatures, transparency, impact resistance, and high adhesion can be appropriately selected.

[0080] The thickness of the second polycarbonate layer can be a thickness typical for decorative sheets, but it is preferable to set it to be above the lower limit in order to suppress the occurrence of defects such as wrinkles when laminating with the metal layer laminate, and it is preferable to set it to be below the upper limit in order to suppress the fracture of the metallic decorative laminate during molding and to improve the moldability of the metallic decorative laminate, preferably 20 μm or more and 500 μm or less, more preferably 50 μm or more and 300 μm or less, even more preferably 80 μm or more and 200 μm or less, and even more preferably 100 μm or more and 150 μm or less.

[0081] (Urethane-based adhesive) The first adhesive layer and the second adhesive layer contain a reaction product of a polyester diol, a polycarbonate diol, and an aliphatic isocyanate, a carbodiimide, and a silane coupling agent having an epoxy group, in an amount of 13.80 parts by mass or more and 14.25 parts by mass or less, wherein the content of the structure derived from the polycarbonate diol is 0.75 parts by mass or more and 1.20 parts by mass or less, the content of the structure derived from the aliphatic isocyanate is 3.20 parts by mass or more and 4.00 parts by mass or less, the content of the structure derived from the carbodiimide is 0.08 parts by mass or more and 0.20 parts by mass or less, and the content of the structure derived from the silane coupling agent is 0.50 parts by mass or more and 0.80 parts by mass or less. Further details will be explained in the [Urethane Adhesive] section.

[0082] The metallic decorative laminate of this embodiment preferably exhibits good hydrolysis resistance. The specific conditions for the hydrolysis resistance test to evaluate hydrolysis resistance are to leave the metallic decorative laminate standing for 72 hours under conditions of a temperature of 90°C and a relative humidity of 95%RH.

[0083] Furthermore, indicators of good hydrolysis resistance are that, before and after the hydrolysis test, the total light transmittance of the metallic decorative laminate is 10% to 20%, the haze is 5.5% or less, and the peel strength of the first and second adhesive layers, as measured by a 180-degree peel test based on JIS K 6854-2, is 20 N / 25 mm or more.

[0084] By having a total light transmittance of 10% to 20%, the metallic decorative laminate achieves sufficient metallic design aesthetics. At the same time, when lighting is turned on from the back of the metallic decorative laminate, it has the advantage of allowing light rays emitted from the lighting to pass through the metallic decorative laminate. Due to this function, in bright daytime environments when the lighting is not turned on, the appearance of the metallic decorative laminate is a metallic design, and in dark nighttime environments, it is possible to make it visible by turning on lighting from the back of the metallic decorative laminate to allow light to pass through. A total light transmittance of 10% or more is preferable because the light rays are not blocked by the metallic decorative laminate, and sufficient light emission is obtained. Furthermore, a total light transmittance of 20% or less is preferable because when light rays are transmitted, the unevenness of the metal deposition in the metal layer is not visible, resulting in excellent design aesthetics.

[0085] Next, when the haze is 5.5% or less, the degree of light diffusion transmitted through the metallic decorative laminate is low, resulting in no cloudiness or opacity on the sheet, thus satisfying excellent metallic design properties. A haze of 5.5% or less is preferable because the degree of light diffusion transmitted through the metallic decorative laminate does not affect the cloudiness or opacity of the sheet, thus satisfying metallic design properties. Furthermore, since cloudiness and opacity of the sheet are suppressed as the haze decreases, the lower limit is not particularly limited.

[0086] Furthermore, a peel force of 20 N / 25 mm or more for the first adhesive layer 20 and the second adhesive layer 50, as measured by a 180-degree peel test based on JIS K 6854-2, serves as an indicator that the first adhesive layer 20 and the second adhesive layer 50 have not undergone hydrolysis, thus maintaining their peel strength and adhesion. In other words, if the peel force is 20 N / 25 mm or more, it can be said that delamination of the adhesive layer due to hydrolysis will not occur. Alternatively, there is no particular upper limit to the peel force, but in the 180-degree peel test, if the peel force is too strong, the adhesive layer will break, so the breakage of the adhesive layer can be considered the upper limit.

[0087] In this embodiment, it is preferable that no cracks occur when the metallic decorative laminate is stretched to 200%. While the metallic decorative laminate may be used without stretching, it may also be formed into a desired shape and processed into a metallic molded body as described later, and the metallic decorative laminate may be stretched during the molding process. The absence of cracks when stretched to 200% serves as an indicator that no cracks will occur in the stretched portion when the metallic decorative laminate is stretched by the molding process. In other words, if no cracks occur when stretched to 200%, there is no need to worry about cracks occurring in the stretched portion of the metallic molded body.

[0088] Preferably, the first adhesive layer and the second adhesive layer of the metallic decorative laminate do not melt at temperatures of 300°C to 320°C.

[0089] When manufacturing a metallic injection-molded article using the aforementioned metallic decorative laminate, for example, polycarbonate resin is melted and injected between the surface of the first polycarbonate layer and / or the surface of the second polycarbonate layer and the injection mold to form a resin layer. The molding temperature of the polycarbonate resin during injection molding is high, ranging from 300°C to 320°C. Therefore, if the first and second adhesive layers melt at a temperature between 300°C and 320°C, washout occurs, resulting in a poor appearance of the metallic injection-molded article.

[0090] In this context, washout specifically refers to the phenomenon in which at least one of the first and second adhesive layers melts due to the heat of the polycarbonate resin during injection molding, resulting in the disappearance of the metal layer on the surface of the metallic injection-molded body near the mold gate.

[0091] However, if the first and second adhesive layers do not melt at temperatures between 300°C and 320°C, washout will not occur, thus preventing defects in the appearance of the metallic injection-molded article caused by washout.

[0092] [Metallic-looking molded body] The metallic-looking molded body of this embodiment comprises a molded body of the metallic-looking decorative laminate (300A or 300B). The metallic-looking decorative laminate is as described above and will not be described further.

[0093] The aforementioned metallic-looking molded body is manufactured, for example, from the metallic-looking decorative laminate by the manufacturing method described later, and is molded into a desired shape according to its purpose. For example, it can be used in the casings and decorative parts of personal computers, TVs, and home appliances, as well as in the casings and decorative parts of pachinko machines, pachislot machines, and game machines, or in general applications such as carry-on bags and suitcases, and can provide metallic-looking decorative and design features in place of plating or metal materials.

[0094] In addition to the above-described configuration, the metallic-looking molded body may also have other configurations. For example, to keep the surface of the protective layer or base layer clean and prevent dirt from adhering until the metallic-looking molded body is used, release paper, protective film, etc., can be provided on the surface of the protective layer or base layer.

[0095] Metallic molded bodies, when combined with backlighting, can sometimes be used to create decorative or aesthetically pleasing designs by transmitting light through the metal layer. In such cases, the metallic molded body is required to be transparent. As previously mentioned, the light transmittance and haze, which are indicators of transparency, will not be explained further.

[0096] [Injection molded product] The injection-molded article of this embodiment comprises an injection-molded resin layer on the surface of the first polycarbonate layer and / or the surface of the second polycarbonate layer of the metallic-looking molded article of this embodiment. The injection-molded article can be further processed and used for the casings and decorative parts of personal computers, TVs, and home appliances, such as smartphone and mobile phone casings, automobile door mirror housings, front grilles, door handles, center wheel caps, emblems, ornaments, garnishes, lamp reflectors, center consoles, and instrument panels. The metallic-looking molded article is as described above and will not be described further.

[0097] The thickness of the resin layer is not particularly limited, but can be, for example, between 100 μm and 20 mm. Furthermore, a thermoplastic resin such as polycarbonate can be used as the resin.

[0098] [Method for manufacturing metallic decorative laminates] The manufacturing method for the metallic decorative laminate of this embodiment includes a first bonding step and a second bonding step, which will be described later. An example of the manufacturing method for the metallic decorative laminate is described below. Note that the metallic decorative laminate (B)3 can be manufactured by referring to the manufacturing method for the metallic decorative laminate (A)2.

[0099] The manufacturing method for the decorative sheet of this embodiment comprises: a first laminate formation step, in which a mixture containing an aqueous polycarbonate-based polyurethane dispersion and a silicone-based surfactant is deposited on the surface of a release resin layer so that the dry film thickness is an average of 10 μm to 25 μm, thereby obtaining a first laminate in which a release resin layer and a metal layer retaining layer are laminated; an unwinding step, in which the winding of the first laminate is unwinded; and a deposition step, in which a metal layer is deposited onto the metal layer retaining layer after the unwinding step, thereby obtaining a second laminate including a metal layer laminate comprising a metal layer retaining layer and a metal layer. The unwinding step and the deposition step are usually performed continuously.

[0100] The manufacturing method for the decorative sheet 300A will be described below in the following order: first laminate formation process, disassembly process, vapor deposition process, first bonding process, and second bonding process.

[0101] (First laminate formation process) In the first laminate formation step, a mixture containing an aqueous polycarbonate-based polyurethane dispersion and a silicone-based surfactant is formed into a film such that the average dry film thickness is 10 μm or more and 25 μm or less. Specifically, the mixture is applied to a release resin layer using a die coater, for example, and dried to form the metal layer retaining layer 40. This forms the metal layer retaining layer 40 without stretching, and the first laminate is obtained.

[0102] By including a silicone-based surfactant in the mixture of raw materials for the metal layer retaining layer 40, when the metal layer retaining layer 40 is formed by casting, the wettability is improved, repulsion during the formation of the metal layer retaining layer 40 is suppressed, and the metal layer retaining layer 40 can be formed uniformly.

[0103] Furthermore, the mixture may also contain carbodiimide. If the solvent resistance of the metal layer retaining layer 40 is insufficient, the metal layer retaining layer 40 may whiten when the urethane adhesive is applied, and the glossiness of the metallic decorative laminate (A) 2 may decrease. By including carbodiimide in the mixture of raw materials for the metal layer retaining layer 40, the solvent resistance of the metal layer retaining layer 40 can be improved and whitening can be suppressed, even when the urethane adhesive contains a solvent.

[0104] The mixture of raw materials for the metal layer retaining layer 40 may further contain water. The inclusion of water in the mixture improves the volatility of the solvent and reduces the viscosity of the raw material mixture, thereby suppressing foaming of the raw material mixture. It also suppresses blocking of the metal layer retaining layer 40.

[0105] Furthermore, in order to obtain a uniform metal layer holding layer 40 film in the first laminate formation step, each raw material may be subjected to filter filtration beforehand when preparing the mixture of raw materials. As the filter used for filter filtration, for example, a filter with a pore size of 1 μm can be used, and the material of the filter can be selected in various ways according to each raw material.

[0106] Furthermore, the drying process after coating the raw material mixture can be carried out under conditions such that solvents and other substances contained in the raw material mixture are sufficiently removed and the metal layer retaining layer 40 film is formed. For example, it can be done at a temperature of about 150°C for about 3 minutes.

[0107] The size of the release resin layer is not particularly limited; for example, considering industrial manufacturing, the width can be 1000 mm or more and 2000 mm or less, and the length can be 300 m or more and 500 m or less. Such a release resin layer is usually in a wound state (winding), and the first laminate is obtained by unwinding this winding, applying a mixture of raw materials for the metal layer holding layer, and then drying it.

[0108] (Unraveling process) Since the first laminate is usually manufactured in a long, continuous length, it is wound up along with the formation of the metal layer holding layer 40 and stored in a wound state before the formation of the metal layer 30. The unwinding process is a process of unwinding such a wound of the first laminate prior to the formation of the metal layer 30.

[0109] (vapor deposition process) The deposition process involves depositing the metal layer 30 onto the metal layer holding layer 40 after the disintegration process. The deposition process yields a metal layer laminate 1 comprising the metal layer holding layer 40 and the metal layer 30.

[0110] Furthermore, the metal layer laminate comprising the metal layer laminate 1 may be distributed or stored as an intermediate for the metallic decorative laminate (A) 2 or the metallic decorative laminate (B) 3.

[0111] (1st adhesion process) The first bonding step involves applying a urethane-based adhesive to the first polycarbonate layer 10 and / or the metal layer laminate 1, allowing the urethane-based adhesive to dry, and then bonding the first polycarbonate layer 10 and the metal layer laminate 1 together.

[0112] In manufacturing the metallic decorative laminate (A) 2, after the vapor deposition process, a urethane-based adhesive is applied to the metal layer 30 of the second laminate comprising the first polycarbonate layer 10 and / or the metal layer laminate 1, and after drying, the metal layer 30 and the first polycarbonate layer 10 are bonded together. This bonding also forms the first adhesive layer 20.

[0113] In other words, in the first bonding step, a urethane-based adhesive is applied to at least one of the metal layer 30 and the first polycarbonate layer 10 of the metal layer laminate 1, or it may be applied to one or both.

[0114] Furthermore, when manufacturing the metallic decorative laminate (B) 3, after the vapor deposition process, a urethane-based adhesive is applied to the metal layer holding layer 40 of the second laminate comprising the first polycarbonate layer 10 and / or the metal layer laminate 1, and after drying, the metal layer holding layer 40 and the first polycarbonate layer 10 are bonded together. This bonding also forms the first adhesive layer 20.

[0115] In other words, in the first bonding step, a urethane-based adhesive is applied to at least one of the metal layer holding layer 40 and the first polycarbonate layer 10 of the metal layer laminate 1, or it may be applied to one or both.

[0116] (Second adhesion process) The second bonding step involves applying a urethane-based adhesive to the metal layer laminate 1 and / or the second polycarbonate layer 60, allowing the urethane-based adhesive to dry, and then bonding the metal layer laminate 1 and the second polycarbonate layer 60 together.

[0117] In manufacturing the metallic decorative laminate (A) 2, after the vapor deposition process, a urethane-based adhesive is applied to the second polycarbonate layer 60 and / or the metal layer holding layer 40 of the second laminate comprising the metal layer laminate 1, and after drying, the metal layer holding layer 40 and the second polycarbonate layer 60 are bonded together. This bonding also forms the second adhesive layer 50.

[0118] In other words, in the second bonding step, the urethane adhesive is applied to at least one of the metal layer holding layer 40 and the second polycarbonate layer 60 of the metal layer laminate 1, or it may be applied to one or both.

[0119] Furthermore, when manufacturing the metallic decorative laminate (B) 3, after the vapor deposition process, a urethane-based adhesive is applied to the metal layer 30 of the second laminate comprising the second polycarbonate layer 60 and / or the metal layer laminate 1, and after drying, the metal layer 30 and the second polycarbonate layer 60 are bonded together. This bonding also forms the second adhesive layer 50.

[0120] In other words, in the second bonding step, a urethane-based adhesive is applied to at least one of the metal layer 30 and the second polycarbonate layer 60 of the metal layer laminate 1, or it may be applied to one or both.

[0121] The order of these bonding processes is not particularly limited; the first bonding process may be performed first, followed by the second bonding process, or the second bonding process may be performed first, followed by the first bonding process, or the first and second bonding processes may be performed in parallel.

[0122] Furthermore, in the manufacturing method of the decorative sheet of this embodiment, a roll of a laminate (first laminate) of a release resin layer and a metal layer holding layer 40 was used, but the metal layer 30 may be laminated without rolling up the first laminate.

[0123] [Method for manufacturing metallic molded products] The method for manufacturing a metallic-looking molded body according to this embodiment includes a molding step of bringing the metallic-looking decorative laminate of this embodiment, which has a surface temperature of 150°C or more and 200°C or less, into close contact with a mold to obtain a molded body of the metallic-looking decorative laminate.

[0124] (molding process) To thermoform a metallic decorative laminate, the surface temperature of the metallic decorative laminate must be between 150°C and 200°C. This prevents drawdown and whitening during molding, thus ensuring good formability. A surface temperature of 150°C or higher prevents the metallic decorative laminate from softening sufficiently, thus avoiding the difficulty of processing and molding caused by drawdown and deformation. Conversely, a surface temperature of 200°C or lower prevents the metallic decorative laminate from becoming too soft and difficult to mold, or from becoming prone to whitening.

[0125] The shape of the mold used to press the metallic decorative laminate can be any shape to enable the formation of the metallic molded body into the desired shape. For example, molds such as male and female molds with a brass surface chrome-plated can be used. Furthermore, the mold temperature can be set to any temperature considering the control of the surface temperature of the metallic decorative laminate and the control of the cooling conditions of the metallic molded body after the molding process.

[0126] As a method for pressing the metallic decorative laminate against a mold, any method can be adopted considering ease of molding and cost, such as straight molding using a female mold, drape molding using a male mold, or plug-assisted molding using a plug (auxiliary mold). In addition, vacuum forming, which sucks the metallic decorative laminate into the mold, or compressed air forming, which uses compressed air pressure to press the metallic decorative laminate against the mold, can be employed. For example, by pressing the metallic decorative laminate against the mold using vacuum and / or compressed air, the adhesion between the metallic decorative laminate and the mold is improved, allowing for processing into more precise shapes.

[0127] (Clamping process) The manufacturing method for the metallic-looking molded body of this embodiment may include a clamping step to clamp the metallic-looking decorative laminate before the molding step. This step allows the metallic-looking decorative laminate to be adjusted and fixed so that it does not sag during molding. Clamping can be performed, for example, by using multiple gripping means capable of gripping both sides of the metallic-looking decorative laminate, for example, by gripping both ends of the metallic-looking decorative laminate. Gripping of the metallic-looking decorative laminate is not limited to both ends, but any part of the metallic-looking decorative laminate can be gripped. Normally, when continuously producing metallic-looking molded bodies, both ends in the width direction of the metallic-looking decorative laminate can be gripped. Also, when batch producing metallic-looking molded bodies using rectangular pieces cut from the metallic-looking decorative laminate to a predetermined length, the ends of all four sides can be gripped with upper and lower frames.

[0128] (Heating process) Furthermore, a method for manufacturing a metallic-looking molded article according to one embodiment of the present invention may include a heating step of heating the metallic-looking decorative laminate after the clamping step. For example, after clamping the metallic-looking decorative laminate at room temperature and adjusting it so that it does not sag, a plurality of heaters or the like can be used as heating means, with these heaters placed above and below the metallic-looking decorative laminate to simultaneously and uniformly heat both sides of the metallic-looking decorative laminate. This heating step makes it possible to control the surface temperature of the metallic-looking decorative laminate to be between 150°C and 200°C.

[0129] (Other processes) The method for manufacturing a metallic-looking molded body may include other steps in addition to the steps described above. For example, a bonding step may be included in which a protective film or the like is attached to the surface of the protective layer or base layer to maintain the surface of the protective layer or base layer in a clean state and prevent contamination until the metallic-looking molded body is processed in the next step. Furthermore, after inserting the metallic-looking molded body into an injection molding die, insert injection molding is performed by injecting resin, and the surface of the injection-molded product can be decorated.

[0130] [Method for manufacturing injection-molded articles] The method for manufacturing an injection-molded article according to this embodiment includes an injection molding step in which, using an injection mold, resin is injected between the surface of the first polycarbonate layer 10 and / or the surface of the second polycarbonate layer 60 of the metallic-looking molded article obtained by the method for manufacturing a metallic-looking molded article according to this embodiment and the injection mold to form a resin layer, thereby obtaining an injection-molded article in which the metallic-looking molded article and the resin layer are integrated. The metallic-looking molded article is as described above and will not be described further.

[0131] The injection molding process can be carried out using a general injection molding machine. Polycarbonate, a thermoplastic resin, can be used as the resin. The polycarbonate can be melted and injected between the surface of the first polycarbonate layer 10 and / or the surface of the second polycarbonate layer 60 and the injection molding die to form a resin layer.

[0132] Furthermore, the method for manufacturing an injection-molded article may include a trimming step in which the metallic-looking molded article is trimmed to an arbitrary shape before the injection molding step, a cooling step in which the molded article is cooled after the injection molding step, and a removal step in which the molded article is removed from the injection molding die after the cooling step.

[0133] [Urethane-based adhesive] The urethane adhesive of this embodiment is a urethane adhesive for a metallic decorative laminate used in this embodiment, and the urethane adhesive is a reaction product of a polyester diol, a polycarbonate diol, and an aliphatic isocyanate, and contains a carbodiimide and a silane coupling agent having an epoxy group.

[0134] Typically, urethane adhesives used for metallic-looking laminates consist only of a polyester diol as the main component, an aliphatic isocyanate as the curing agent, and a solvent to dissolve them. Such urethane adhesives exhibit adhesion by reacting the polyester diol and aliphatic isocyanate to form urethane bonds. However, as mentioned above, these adhesives fail to pass hydrolysis tests under more stringent conditions and do not satisfy the hydrolysis resistance requirements. Furthermore, when polycarbonate resin is used as the resin for injection-molded articles, defects in the appearance of metallic-looking molded products occur due to adhesive washout.

[0135] Therefore, in this embodiment, the main component is changed from solely a polyester diol to a combination of a polyester diol and a polycarbonate diol, with a portion of the polyester diol being replaced by a polycarbonate diol. Furthermore, by increasing the amount of aliphatic isocyanate, the heat resistance of the first and second adhesive layers can be improved. As a result, washout can be prevented, and defects in the appearance of the metallic-looking molded product can be prevented.

[0136] The urethane adhesive of this embodiment uses a combination of polyester diol and polycarbonate diol, increases the amount of aliphatic isocyanate, and also incorporates carbodiimide and a silane coupling agent. As a result, it was able to pass the hydrolysis test under more stringent test conditions, and the adhesive strength improved after the hydrolysis test compared to before the test. Furthermore, the increase in haze value due to the hydrolysis test was suppressed, and excellent metallic appearance was achieved before and after the hydrolysis test.

[0137] In order to satisfy the above-mentioned effect of preventing washout and hydrolysis resistance, it is important that the polyester diol, polycarbonate diol, aliphatic isocyanate, carbodiimide, and silane coupling agent are compatible, and the content ratio of each of these components is also important. The urethane adhesive of this embodiment must have a content of 13.80 parts by mass or more and 14.25 parts by mass or less of the structure derived from the polyester diol, a content of 0.75 parts by mass or more and 1.20 parts by mass or less of the structure derived from the polycarbonate diol, a content of 3.20 parts by mass or more and 4.00 parts by mass or less of the structure derived from the aliphatic isocyanate, a content of 0.08 parts by mass or more and 0.20 parts by mass or less of the structure derived from the carbodiimide, and a content of 0.50 parts by mass or more and 0.80 parts by mass or less of the structure derived from the silane coupling agent.

[0138] Polyester diols have the advantage of excellent adhesion between urethane-based adhesives containing them and other layers, but they may have poor heat resistance and hydrolysis resistance. Similarly, adhesive layers containing polycarbonate diols have the advantage of excellent chemical resistance, hydrolysis resistance, and heat resistance, but there are concerns about reduced adhesion. The aforementioned content was determined by optimizing the balance between adhesion, hydrolysis resistance, and heat resistance. Note that a high amount of polyester diols results in poor heat resistance and hydrolysis resistance, while a high amount of polycarbonate diols results in reduced adhesion.

[0139] In this disclosure, "structure derived from ~" means including each component used in the manufacture of the urethane adhesive and the resulting reactions thereof, and also includes units derived from each component contained in the polymer. This is substantially synonymous with the amount of each component used in the manufacture of the urethane adhesive. Here, "substantially" means excluding the amount removed during the manufacturing process.

[0140] The following describes the preferred amounts of each component relative to 13.80 parts by mass or more and 14.25 parts by mass or less of the structure derived from polyester diols.

[0141] Furthermore, a washout prevention effect can be observed by using a structure derived from polycarbonate diols in an amount of 0.75 parts by mass or more. However, if the amount exceeds 1.2 parts by mass, the adhesive layer using it may have a whitish appearance, and the viscosity of the adhesive may increase, making it difficult to handle. Therefore, the polycarbonate diol should be used in the above mass ratio between 0.75 parts by mass and 1.20 parts by mass.

[0142] Furthermore, the amount of structure derived from aliphatic isocyanates can be determined based on a calculation method that assumes equal amounts of isocyanate groups and hydroxyl groups in general urethane resins. That is, it can be optimized according to the total OH value (mg / KOHg) of polyester diols and polycarbonate diols and the NCO content of the aliphatic isocyanate. If the amount of structure derived from aliphatic isocyanates is too small, sufficient urethane bonds may not be formed, and the adhesive performance may not be satisfactory. On the other hand, if the amount of structure derived from aliphatic isocyanates is too large, the water and isocyanate will react more easily, causing brushing and clouding of the adhesive layer, which may result in an increase in haze value and defects in total light transmittance as a metallic decorative laminate.

[0143] In the above mass ratio, an improvement in hydrolysis resistance can be obtained by setting the amount of the structure derived from carbodiimide to 0.08 parts by mass or more and 0.20 parts by mass or less. If the amount of the structure derived from carbodiimide is less than 0.08 parts by mass, the improvement in hydrolysis resistance may be insufficient, and the improvement in hydrolysis resistance does not increase even if it exceeds 0.20 parts by mass, so it is sufficient to set the upper limit at 0.20 parts by mass.

[0144] As the carbodiimide, a commercially available solution can be used, and a carbodiimide containing 0% to 0.50% by mass of NCO groups can be used.

[0145] In the above mass ratio, by setting the amount of structure derived from the silane coupling agent to 0.50 parts by mass or more and 0.80 parts by mass or less, hydrolysis resistance can be satisfied when used in combination with carbodiimide, and the product can pass hydrolysis tests under more stringent test conditions. A sufficient improvement in hydrolysis resistance can be obtained by setting the amount of structure derived from the silane coupling agent to 0.50 parts by mass or more. Furthermore, if the amount of structure derived from the silane coupling agent is 0.8 parts by mass or less, aggregation and whitening of the silane coupling agent can be suppressed, and an increase in haze value and defects in total light transmittance can be suppressed as a metallic decorative laminate.

[0146] As a silane coupling agent, one having an epoxy group as an organic functional group can be used. For example, 3-glycidoxypropyltrimethoxysilane can be used.

[0147] Furthermore, there is an example of use where a light is turned on from the back of the metallic decorative laminate, and the light rays emitted from the light are transmitted through the metallic decorative laminate. In this example, when the light is not turned on in a bright daytime environment, the appearance of the metallic decorative laminate will be the metallic design of the metal layer, and in a dark nighttime environment, when the light is turned on from the back of the metallic decorative laminate, it will have a design that combines the metal layer and the transmitted light. [Examples]

[0148] The present invention will be described in more detail below using examples. However, the present invention is not limited in any way to the following examples.

[0149] (Evaluation method) [Evaluation of metallic-looking decorative laminates] 1. Adhesive layer thickness (Adhesive layer thickness in Tables 4-7) The thickness of the adhesive layer was measured by slicing the cross-section of the metallic decorative laminate using a microtome and observing the thickness with a microscope. The thickness of the first and second adhesive layers were the same.

[0150] 2. Appearance Evaluation The appearance of the metallic-look laminate was visually inspected to evaluate for any defects such as brightness, unevenness, and fading. If there were no defects such as brightness, unevenness, or fading, it was marked as "A," indicating a pass. If there were defects such as brightness, unevenness, or fading, it was marked as "B," indicating a fail.

[0151] 3.Optical properties The total light transmittance and haze value were measured for the manufactured metallic decorative laminates before and after the hydrolysis test. A light transmittance of 10% to 20% or higher and a haze of 5.5% or lower were judged as passing, while all other cases were judged as failing.

[0152] Total light transmittance and haze were measured using a Haze Meter NDH 7000SPII (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7105.

[0153] The hydrolysis test involved placing the metallic decorative laminate in a constant temperature and humidity chamber at 90°C and 95% RH for 72 hours. After the hydrolysis test, the metallic decorative laminate was removed from the chamber and left to stand at 25°C for 1 hour before measuring the total light transmittance and haze value. In Tables 4-7, "Optical Properties" refers to the values ​​before the hydrolysis test, and "Optical Properties After Hydrolysis" refers to the values ​​after the hydrolysis test.

[0154] 4. Adhesion The adhesion of the adhesive layer of the manufactured metallic decorative laminate was evaluated before and after the hydrolysis test using a 180-degree peel test based on JIS K 6854-2. Specifically, when testing the adhesion of the adhesive layer between the polycarbonate layer and the metal layer holding layer, a test specimen was prepared by making cuts in the metallic decorative laminate so that the polycarbonate layer and the metal layer holding layer could be clamped by the upper and lower chucks, respectively, and the peel test was performed. Similarly, when testing the adhesion of the adhesive layer between the polycarbonate layer and the metal layer, a test specimen was prepared by making cuts in the metallic decorative laminate so that the polycarbonate layer and the metal layer could be clamped by the upper and lower chucks, respectively, and the peel test was performed. A peel force of 20 N / 25 mm or more between the first and second adhesive layers was considered acceptable, while a peel force of less than 20 N / 25 mm was considered unacceptable.

[0155] The hydrolysis test involved placing the metallic decorative laminate in a constant temperature and humidity chamber at 90°C and 95% RH for 72 hours. After the hydrolysis test, the test specimen was removed from the chamber and left to stand at 25°C for 1 hour. The adhesion of the metallic decorative laminate was then evaluated using a 180° peel test based on JIS K 6854-2. In Tables 4-7, "Adhesion" refers to the value before the hydrolysis test, and "Adhesion after Hydrolysis" refers to the value after the hydrolysis test.

[0156] [Evaluation of injection-molded products] 5. Evaluation of Optical Properties The total light transmittance and haze value of the manufactured injection-molded articles were measured before and after the hydrolysis test. Articles were judged to pass if the light transmittance was 10% to 20% or higher and the haze was 5.5% or lower; otherwise, they were judged to fail.

[0157] Total light transmittance and haze were measured using a Haze Meter NDH 7000SPII (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7105.

[0158] The hydrolysis test involved placing the injection-molded body in a constant temperature and humidity chamber at 90°C and 95% RH for 72 hours. After the hydrolysis test, the injection-molded body was removed from the chamber and left to stand at 25°C for 1 hour before measuring the total light transmittance and haze value. In Tables 4-7, "Optical Properties of Injection Molded Body" refers to the values ​​before the hydrolysis test, and "Optical Properties of Injection Molded Body After Hydrolysis" refers to the values ​​after the hydrolysis test.

[0159] 6. Appearance evaluation of injection-molded products. The appearance of the metallic decorative laminate at the corners and edges of the injection-molded product was visually observed. Due to preform molding and injection molding, the metallic decorative laminate at the corners and edges was stretched to a degree equivalent to 200% of its original stretch. The metal layer holding layer, the first polycarbonate layer, and the second polycarbonate layer of the metallic decorative laminate are easily stretched, and therefore no abnormalities were observed in these layers at the corners and edges of the injection-molded product. However, because the first and second adhesive layers use adhesives that crosslink by urethane bonding, depending on the adhesive formulation, the stretch may not be sufficient, and as a result, cracks may occur at the corners and edges of the injection-molded product due to inability to withstand the stretch, causing the appearance to become cloudy. Since injection-molded products exhibiting such cloudiness are considered defective, the presence or absence of cloudiness was visually evaluated in this evaluation. Products without cloudiness and without abnormalities were rated A, meaning they passed, and products with cloudiness or obvious cracks were rated B, meaning they failed. <Checking whether or not the garment has been washed out> The appearance of the injection-molded bodies near the gate was visually inspected to check for the presence or absence of washout. Figure 3 shows schematic diagrams of an injection-molded body 1100 without washout (Figure 4(A)) and an injection-molded body 1200 with washout (Figure 4(B)). The portions protruding from the injection-molded bodies 1100 and 1200 are the gate portions 1110 and 1210, where the polycarbonate injected into the mold solidified inside the gate. Figures 4(A) and (B) schematically show the gate portions 1110 and 1210 and parts of the injection-molded bodies 1100 and 1200 around them. In the injection-molded body 1200, a washout portion 1220 was observed near the gate portion 1210, where the metallic decorative laminate had dissolved and chipped off in an elliptical shape (Figure 4(B)). On the other hand, no abnormalities such as washout were observed in the metallic decorative laminate of the injection-molded body 1100, even around the gate portion 1110 (Figure 4(A)). Note that the shape of the washout is not limited to an elliptical shape like the washout portion 1220, but can take on various shapes. In this evaluation, as shown in Figure 3(A), injection-molded body 1100 in which no abnormalities were observed in the metallic decorative laminate around the gate portion 1110 was designated as A, meaning it passed, while injection-molded body 1200 in which the metallic decorative laminate around the gate portion 1210 was dissolved and chipped was designated as B, meaning it failed.

[0160] The evaluation results for each are shown in Tables 3 to 7. In Tables 3 to 7, the column for PU-PC shows the peel strength of the adhesive layer between the metal layer holding layer and the polycarbonate layer, and the column for PC-In shows the peel strength of the adhesive layer between the polycarbonate layer and the metal layer.

[0161] [Manufacturing of metallic-looking decorative laminates] <Manufacturing of polycarbonate layers> A 125 μm thick film was created by extruding polycarbonate resin (S2000, manufactured by Mitsubishi Engineering Plastics Co., Ltd.). This film was cut to A3 size (297 mm x 420 mm) and used as the film for the first and second polycarbonate layers.

[0162] <Manufacturing of Metal Layer Laminates> A mixture containing polycarbonate polyurethane and a silicone surfactant was obtained by mixing 21 parts of aqueous polyurethane dispersion (UW5002 (manufactured by Ube Industries)), 9 parts of aqueous polyurethane dispersion (UW5502 (manufactured by Ube Industries)), 0.3 parts of silicone surfactant (BYK-345 (manufactured by BYK)), and 6 parts of water. This mixture was applied to a release resin layer (PET film (G2000 (manufactured by Toyobo)) and dried at 150°C for 3 minutes. After drying, the release resin layer was peeled off to produce a metal layer retaining layer with a dry thickness of 20 μm. Indium was deposited onto this metal layer retaining layer by vacuum deposition to form a metal layer with a thickness of 50 nm, and a metal layer laminate was produced. This metal layer laminate was cut to A3 size (297 mm x 420 mm) and used as the metal layer laminate.

[0163] <Bonding of polycarbonate layer and metal layer laminate> A urethane-based adhesive for metallic decorative laminates was used, which consisted of a main component comprising a mixture of polyester diol, polycarbonate diol, carbodiimide, a silane coupling agent having an epoxy group, and ethyl acetate (EtAC), and a curing agent consisting of an aliphatic isocyanate.

[0164] Here, TM-K51 (manufactured by Toyo Morton Co., Ltd.) was used as the polyester diol, Duranol T5652 (manufactured by Asahi Kasei Corporation) was used as the polycarbonate diol, CAT-RT85 (manufactured by Toyo Morton Co., Ltd.) was used as the aliphatic isocyanate, Carbodilite V-07 (manufactured by Nisshinbo Chemical Co., Ltd.) was used as the carbodiimide, and KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the silane coupling agent having an epoxy group (indicated as "silane coupling agent" in the table).

[0165] Tables 1-3 show the formulations of urethane-based adhesives for metallic decorative laminates in Examples 1-7 and Comparative Examples 1-11.

[0166] [Table 1]

[0167] [Table 2]

[0168] [Table 3]

[0169] A urethane-based adhesive was applied to the surface of the metal layer of the metal layer laminate using a bar coater so that the dry film thickness of the first adhesive layer was approximately 10 μm. After drying the coated material at 60°C for 1 minute, the coated material was laminated with the metal layer and the polycarbonate layer. On the surface of the metal layer holding layer of this laminated metal layer laminate, a urethane-based adhesive was applied using a bar coater so that the dry film thickness of the second adhesive layer was approximately 10 μm. After drying the coated material at 60°C for 1 minute, the coated material was laminated with the metal layer holding layer and the polycarbonate layer, and then cured at 30°C for 10 days to obtain a metallic decorative laminate.

[0170] Lamination was performed using a die laminating machine (EXCELAMII-355Q, manufactured by GMP), with the temperature of the pressure roll on the polycarbonate layer side set to 130°C and the sheet feed speed set to 0.3 m / min.

[0171] Based on the above, metallic decorative laminates of Examples 1-7 and Comparative Examples 1-11 were manufactured. Note that Examples 1-7 and Comparative Examples 1-11 differed in the formulation of the urethane adhesive, but all other conditions were the same. Furthermore, in Examples 1-7 and Comparative Examples 1-11, the first polycarbonate layer and the second polycarbonate layer used the same polycarbonate layer, meaning there was no difference in the film, and the first adhesive layer and the second adhesive layer used the same urethane adhesive, meaning there was no difference in the adhesive.

[0172] [Manufacturing of metallic-looking molded products] Using a compression molding machine, the metallic decorative laminate was clamped, and then, with a pre-shaping temperature of 200°C and a compressed air pressure of 6 bar, the metallic decorative laminate was pre-formed to fit the mold for injection molding. Unnecessary parts that protruded from the mold were trimmed to obtain a metallic molded product.

[0173] [Manufacturing of injection-molded products] A metallic-looking molded body was inserted into the mold of an injection molding machine, and polycarbonate (Yupilon S-2000R535, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) was injected by insert injection molding to create an injection-molded body with dimensions of 104 mm × 78.5 mm × 9.3 mm, a wall thickness of 3 mm, and a radius of curvature of 5 mm at the corners and edges. The injection resin temperature for the polycarbonate during injection molding was 300°C. Figure 2 shows a front view and a side view of the manufactured injection-molded body 1000. Figure 2(A) is a front view of the injection-molded body 1000, Figure 2(B) is a side view of the injection-molded body 1000 viewed from the X direction of Figure 2(A), and Figure 2(C) is a side view of the injection-molded body 1000 viewed from the Y direction of Figure 2(A).

[0174] [Table 4]

[0175] [Table 5]

[0176] [Table 6]

[0177] [Table 7]

[0178] [result] The results of Examples 1-7 shown in Tables 4 and 5 indicate that the visual appearance was good and the design requirements were met. There were no problems in the molding of the metallic-looking molded articles and injection-molded articles, and no clouding, cracks, or washout occurred, indicating good moldability. Furthermore, there were no abnormalities in total light transmittance or haze values ​​before and after the hydrolysis test, which is a condition that causes problems in existing products, and adhesion was also good. In fact, adhesion performance improved after the hydrolysis test.

[0179] Specifically, it was confirmed that by having a structure content of 13.8 parts by mass or more and 14.25 parts by mass or less derived from the polyester diol used, a structure content of 0.75 parts by mass or more and 1.2 parts by mass or less derived from the polycarbonate diol used, a structure content of 3.2 parts by mass or more and 4.0 parts by mass or less derived from the aliphatic isocyanate used, a structure content of 0.08 parts by mass or more and 0.2 parts by mass or less derived from the carbodiimide used, and a structure content of 0.5 parts by mass or more and 0.8 parts by mass or less derived from the silane coupling agent used, it is possible to satisfy hydrolysis resistance without impairing design and moldability, and to improve the appearance defects of metallic molded products caused by washout.

[0180] The results from Comparative Examples 1 to 11 shown in Tables 6 and 7 indicate that the absence of polycarbonate diols resulted in washout (Comparative Examples 1 and 5). The absence of carbodiimide reduced optical properties and adhesion after hydrolysis testing (Comparative Examples 1, 7, and 8). Furthermore, a high amount of carbodiimide reduced adhesion after hydrolysis testing (Comparative Example 4). The absence or insufficient amount of epoxy group-containing silane coupling agent reduced adhesion after hydrolysis testing (Comparative Examples 1 to 4 and 6). A high amount of aliphatic isocyanate resulted in poor appearance with cracks or clouding at the corners and edges of the injection-molded article, and also reduced adhesion after hydrolysis testing (Comparative Examples 9 to 11).

[0181] [summary] From the above, it has become clear that the present invention can provide a metallic decorative laminate, a metallic molded article, an injection molded article, a method for manufacturing a metallic decorative laminate, a method for manufacturing a metallic molded article, a method for manufacturing an injection molded article, and a urethane-based adhesive, which can satisfy hydrolysis resistance without impairing design and moldability, and can improve the appearance defects of metallic molded articles caused by washout.Therefore, the present invention has been found to be industrially useful. [Explanation of Symbols]

[0182] 1: Metal layer laminate 2: Metallic decorative laminate (A) 3: Metallic decorative laminate (B) 10: First polycarbonate layer 20: 1st adhesive layer 30: Metal layer 40: Metal layer retention layer 50:Second adhesive layer 60: Second polycarbonate layer 100: Thickness direction 110: Width direction 120: Longitudinal direction 1000: Injection molded body 1100: Injection molded body 1110: Gate section 1200: Injection molded body 1210: Gate section 1220: Washout section

Claims

1. First polycarbonate layer, a first adhesive layer; Metal layer laminate containing a metal layer, Second adhesive layer and, The second polycarbonate layer is included in this order, The first adhesive layer and the second adhesive layer contain a reaction product of a polyester diol, a polycarbonate diol, and an aliphatic isocyanate, a carbodiimide, and a silane coupling agent having an epoxy group. A metallic decorative laminate wherein the content of the structure derived from the polyester diol in the first adhesive layer and the second adhesive layer is 13.8 parts by mass or more and 14.25 parts by mass or less, the content of the structure derived from the polycarbonate diol is 0.75 parts by mass or more and 1.2 parts by mass or less, the content of the structure derived from the aliphatic isocyanate is 3.20 parts by mass or more and 4.00 parts by mass or less, the content of the structure derived from the carbodiimide is 0.08 parts by mass or more and 0.20 parts by mass or less, and the content of the structure derived from the silane coupling agent is 0.50 parts by mass or more and 0.80 parts by mass or less.

2. Before and after a hydrolysis test in which a metallic decorative laminate was left standing for 72 hours under conditions of 90°C and 95% relative humidity, The total light transmittance is between 10% and 20% for both. The haze levels were both below 5.5%. The metallic decorative laminate according to claim 1, wherein the peel strength of the first adhesive layer and the second adhesive layer, as determined by a 180-degree peel test based on JIS K 6854-2, is 20 N / 25 mm or more.

3. A metallic molded body comprising a molded body of a metallic decorative laminate as described in claim 1 or 2.

4. An injection-molded article comprising an injection-molded resin layer on the surface of the first polycarbonate layer and / or the surface of the second polycarbonate layer of the metallic-looking molded article according to claim 3.

5. Applying a urethane-based adhesive to the first polycarbonate layer and / or the metal layer laminate, drying the urethane-based adhesive, and then bonding the first polycarbonate layer and the metal layer laminate via the first adhesive layer, The process involves applying a urethane-based adhesive to the metal layer laminate and / or the second polycarbonate layer, allowing the urethane-based adhesive to dry, and then bonding the metal layer laminate and the second polycarbonate layer together via the second adhesive layer. A method for manufacturing a metallic decorative laminate according to claim 1 or 2, including the method described above.

6. A method for manufacturing a metallic molded body, comprising a molding step of bringing a metallic decorative laminate according to claim 1 or 2, having a surface temperature of 150°C or more and 200°C or less, into close contact with a mold to obtain a molded laminate having metallic decoration.

7. A method for manufacturing an injection-molded article, comprising an injection molding step of using an injection molding die to inject resin between the surface of the first polycarbonate layer and / or the surface of the second polycarbonate layer of the metallic-looking molded article obtained by the method for manufacturing a metallic-looking molded article according to claim 6 and the injection molding die to form a resin layer, thereby obtaining an injection-molded article in which the metallic-looking molded article and the resin layer are integrated.

8. A urethane adhesive containing a polyester diol, a polycarbonate diol, an aliphatic isocyanate, a carbodiimide, and a silane coupling agent having an epoxy group, wherein the content of the structure derived from the polyester diol is 13.80 parts by mass or more and 14.25 parts by mass or less, the content of the structure derived from the polycarbonate diol is 0.75 parts by mass or more and 1.20 parts by mass or less, the content of the structure derived from the aliphatic isocyanate is 3.20 parts by mass or more and 4.00 parts by mass or less, the content of the structure derived from the carbodiimide is 0.08 parts by mass or more and 0.20 parts by mass or less, and the content of the structure derived from the silane coupling agent is 0.50 parts by mass or more and 0.80 parts by mass or less.

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