Metallic-look decorative laminate

Abstract

The present invention aims to provide a metallic decorative laminate having excellent moldability, excellent millimeter-wave transmittance, scratch resistance, and design properties, as well as a multilayer laminate and a metallic article containing the said metallic decorative laminate. The present invention relates to a metallic decorative laminate comprising a surface layer, a metal layer, and a base layer in that order, wherein the surface layer contains a polyurethane resin and the base layer contains a polycarbonate resin; a multilayer laminate further comprising a surface protective layer on the side of the surface layer of the metallic decorative laminate opposite to the metal layer; and a metallic article comprising the metallic decorative laminate.

Description

Technical Field

[0001] The present invention relates to a metallic decorative laminate, a multilayer laminate, and a metallic article.

Background Art

[0002] In order to improve the designability of a molded body, a metallic luster (hereinafter also referred to as a metallic design) has been imparted to the surface of the molded body. For imparting a metallic luster, metal plating has been performed since ancient times (Patent Document 1).

[0003] As a method of imparting a metallic design to an article, a method using a metallic decorative film having a metal vapor deposition layer is also known (Patent Document 2). Since the metallic decorative film having a metal vapor deposition layer has a metal layer in its structure, external light is reflected by the metal layer (hereinafter referred to as metal layer reflected light), and is recognized as a metallic design by an observer.

[0004] As another method, an electromagnetic wave transmissive bright coating resin product having a bright coating film using a flat bright material made of aluminum is also known (Patent Document 3).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a metallic decorative laminate having excellent moldability, excellent millimeter wave transmissivity, scratch resistance, and designability, and a multilayer laminate and a metallic article including the metallic decorative laminate. [Means for solving the problem]

[0007] As a result of diligent research to solve the above problems, the inventors provide the following [1] to [3]. [1] A metallic decorative laminate comprising a surface layer, a metal layer, and a base layer in that order, wherein the surface layer contains a polyurethane resin and the base layer contains a polycarbonate resin. [2] A multilayer laminate comprising a metallic decorative laminate as described in [1], further including a surface protective layer on the side opposite to the metal layer of the surface layer. [3] A metallic article, including the metallic decorative laminate described in [1]. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a metallic decorative laminate having excellent moldability, excellent millimeter-wave transmittance, scratch resistance, and design properties, as well as a multilayer laminate and a metallic article containing the metallic decorative laminate. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an example of a metallic decorative laminate according to this embodiment. [Figure 2] This is a conceptual diagram illustrating the reflected light from the metal layer in this embodiment. [Figure 3] This is a schematic diagram illustrating a metal layer. [Modes for carrying out the invention]

[0010] Patent Document 1 describes an invention relating to a plated synthetic resin component for vehicles that exhibits a metallic luster when plated. However, metal plating has problems such as a complex process and high manufacturing costs, as well as the generation of wastewater which puts a burden on the environment. In addition, it was difficult to apply a uniform and beautiful plating film when the surface of the molded body had an uneven shape.

[0011] Sensors such as millimeter-wave radar are used to detect obstacles around vehicles such as automobiles. Millimeter-wave radar is a device that measures the distance to an obstacle by irradiating it with radio waves with a wavelength of 1 to 10 mm, measuring the time it takes for the waves to reflect back from the obstacle, and so on. Millimeter-wave radar is less affected by weather conditions such as rain and fog, and can detect obstacles at a distance, so it has been adopted by many automobile manufacturers. For automobiles, the millimeter-wave band in the 76 to 77 GHz range is used, and the millimeter-wave radar device itself is mounted, for example, behind the bumpers or emblems on the front and rear of the automobile body, and the millimeter waves are emitted from the device through the bumpers or emblems to the obstacle. Normally, automobile bumpers and emblems are manufactured by molding resins such as polypropylene or polycarbonate and then painting them, but in the case of automobiles with metallic paint on the body, the bumpers are also required to have a metallic appearance and millimeter-wave transparency (hereinafter referred to as "millimeter-wave transparency").

[0012] In the case of metal plating, millimeter waves cannot be transmitted, so it cannot be used for the metallic decorative components of bumpers and emblems as described above.

[0013] For this reason, decorative films having a metal vapor deposition layer (Patent Document 2) and decorative films having a glossy coating using a flat, glossy material made of aluminum (Patent Document 3) have been developed, but there is a need for improvement in their moldability. Furthermore, there has been a strong demand for the development of a metallic-looking decorative laminate that satisfies the requirements for scratch resistance.

[0014] In contrast, the metallic decorative laminate of this disclosure provides a metallic decorative laminate that exhibits excellent formability and a superior metallic design, as well as a multilayer laminate and a metallic article including the metallic decorative laminate.

[0015] The following describes the metallic-looking laminates, multilayer laminates, and metallic-looking articles according to the present invention. However, the present invention is not limited to the following examples.

[0016] In the present disclosure, the thickness direction 100 refers to the stacking direction of the metallic decorative laminate or the metallic article, as illustrated in FIG. 1. 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 the metallic article. For example, when manufacturing the metallic decorative laminate in a roll-to-roll manner, 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.

[0017] Hereinafter, embodiments of the present disclosure (hereinafter sometimes referred to as "the present embodiments") will be described. In the present disclosure, numerical values related to descriptions of numerical ranges such as "above", "below", "~", etc. are numerical values that can be arbitrarily combined.

[0018] Also, 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. Combinations of preferable ones can be said to be more preferable.

[0019] 〔Metallic Decorative Laminate〕 The metallic decorative laminate of the present embodiment includes a surface layer, a metal layer, and a base material layer in this order, and it is required that the surface layer contains a polyurethane-based resin and the base material layer contains a polycarbonate-based resin.

[0020] The metallic decorative laminate of the present embodiment can be used, for example, to decorate resin parts and metal parts such as automotive bumpers (hereinafter also simply referred to as "articles") by film decoration methods such as insert molding and overlay molding using a multilayer laminate including the metallic decorative laminate. Further, the metallic decorative laminate may be used to decorate the surface of an article via an adhesive layer or an adhesive bond layer, and can be used as the surface layer of the metallic article described later. Also, the metallic decorative laminate of the present embodiment exhibits an excellent metallic design and is excellent in scratch resistance and weather resistance, and thus is preferable for outdoor use.

[0021] Furthermore, as shown in Figure 2, the metallic decorative laminate 1 of this embodiment reflects ambient light 5 with the metal layer 30, and the observer 4 sees the reflected light 6 from the metal layer, thus perceiving it as having a metallic luster. Naturally, as ambient light 5 decreases, such as at night, the observer 4 will no longer be able to perceive the metallic luster. As a result, the metallic article loses its aesthetic appeal.

[0022] However, in this embodiment, if a light source 7 is placed on the side opposite to the observer 4 and the illumination light 8 is shone onto the metallic decorative laminate 1, the observer 4 can see the light transmitted through the laminate 9, so that the metallic article can exhibit its design even in the absence of ambient light 5.

[0023] In this disclosure, "design appeal" refers to the property that a metallic-looking article using the metallic-looking decorative laminate of this disclosure exhibits a metallic-looking design appeal due to the reflected light 6 of the metal layer, and the property that exhibits a design appeal due to the transmitted light 9 of the laminate. Design appeal is obtained by appropriately setting the total light transmittance and the reflectance of the specular reflection component described below.

[0024] The layer thickness of the metallic decorative laminate in this embodiment can be adjusted as appropriate according to the required specifications. To improve at least one of the aesthetic properties, scratch resistance, and weather resistance, it is preferable to have a thickness of 50 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, and still more preferably 200 μm or more. To improve at least one of millimeter-wave transmittance and moldability, it is preferable to have a thickness of 1000 μm or less, more preferably 800 μm or less, even more preferably 600 μm or less, and still more preferably 500 μm or less.

[0025] To achieve this balance, the particle size is preferably 50 μm to 1000 μm, more preferably 100 μm to 800 μm, even more preferably 150 μm to 600 μm, and even more preferably 200 μm to 500 μm.

[0026] In this disclosure, "scratch resistance" means the property of suppressing the occurrence of scratches, etc., and can be evaluated, for example, by the method described in the examples.

[0027] In this disclosure, "weather resistance" means the property of being resistant to deformation, discoloration, deterioration, etc., when used outdoors, and can be evaluated, for example, by the method described in the examples.

[0028] In this disclosure, "formability" refers to the ease of manufacturing when producing 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.

[0029] In this embodiment, the metallic decorative laminate preferably has a total light transmittance of 30% or less of light irradiated from the surface layer side, and a specular reflectance of 20% or more of light irradiated from the base layer side. This is preferable because it allows the design to be expressed by ambient light 5 and the design to be expressed by irradiated light 8. Furthermore, by setting the total light transmittance and reflectance within the above range, when the metallic article is made as described later, the observer 4 will not be able to see the article with the metallic decorative laminate through the metallic decorative laminate, thus suppressing the influence of the article on the design of the metallic article, which is preferable.

[0030] The total light transmittance and reflectance of the metallic decorative laminate of this embodiment can be set to a desired range by adjusting the total light transmittance and refractive index of the surface layer and / or the base layer, but it is more preferable to adjust them by setting the metal layer to a specific metal type and its thickness to a specific range. Since the millimeter-wave transmittance has a trade-off relationship with the reflectance, it is preferable to adjust the metal type and thickness of the metal layer.

[0031] In this embodiment, the total light transmittance of the metallic decorative laminate irradiated from the surface layer side is preferably set to a high lower limit in order to bring out the metallic design with ambient light 5, and to improve the millimeter-wave transmittance, it is preferable to set to a low upper limit. To satisfy these requirements, it is preferable to balance the total light transmittance of the metallic decorative laminate irradiated from the surface layer side and the reflectance of the specular reflection component of the light irradiated from the substrate layer side of this embodiment.

[0032] In this embodiment, it is preferable that the total light transmittance of the metallic decorative laminate irradiated from the surface layer side is 30% or less, and the reflectance of the specular reflection component of the light irradiated from the substrate layer side is 20% or more.

[0033] The total light transmittance is preferably 1% to 30%, more preferably 5% to 25%, even more preferably 7% to 23%, even more preferably 8% to 18%, and particularly preferably 10% to 16%.

[0034] The reflectance is preferably 20% to 70%, more preferably 30% to 65%, even more preferably 38% to 63%, even more preferably 40% to 60%, and particularly preferably 45% to 55%.

[0035] The total light transmittance of light irradiated from the surface layer side and the reflectance of the specular reflection component of light irradiated from the substrate layer side can be measured, for example, by the method described in the examples.

[0036] The total light transmittance of light irradiated from the surface layer and the reflectance of the specular reflection component of light irradiated from the substrate layer can also be adjusted by the thickness and material of other layers, if those layers are included, and by the type and amount of dye added, if the metallic decorative laminate further contains dyes.

[0037] The metallic decorative laminate of this embodiment may include only the surface layer, metal layer, and base layer described later, in that order, but may also further include the adhesive layer and / or other layers described later, and may further include an adhesive layer between the metal layer and the base layer.

[0038] When the metallic decorative laminate of this embodiment is installed on an article to form a metallic article as described later, it is preferable that the base layer is on the article side, the surface layer is on the observer side, and the surface layer is the outermost surface of the metallic article.

[0039] <Metal layer> The metal layer included in the metallic decorative laminate of this embodiment is not particularly limited as long as it is a layer formed of a metal that exhibits excellent design properties and excellent millimeter-wave transmittance through the reflected light 6 of the metal layer and / or transmitted light 9 of the laminate. The metal may be a single metal or an alloy. From the perspective of design properties, a metal that can impart sufficient metallic luster to the metallic decorative laminate is preferred, and from the perspective of formability, a metal with excellent malleability is preferred. The metal is preferably 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.

[0040] Among these metals, indium, tin, or alloys thereof are particularly preferred when performing deep drawing for three-dimensional molding. In particular, using indium or an indium alloy is preferable because, when used to create a metallic-looking article, it conforms to various shapes of the molded body while exhibiting excellent design properties. It is also preferable that the metal layer contains indium.

[0041] Furthermore, it is more preferable if the metal layer consists of high-purity indium of 99.9% or more, as this allows for deep drawing and application to the formation of molded articles with extremely small radii of curvature. When forming conventional deep-drawn molded articles, aluminum, zinc, gallium, nickel, tin, silver, gold, silicon, chromium, titanium, platinum, palladium, nickel, stainless steel, and / or Hastelloy may be used as a mixture with indium, or these metals may be used as alloys with indium. In particular, indium or tin combined with these metals or indium-tin alloys is preferable because it exhibits excellent design properties.

[0042] The metal layer may be a uniform layer, or it may be a layered structure with a continuous arrangement of metal island structures. Figure 3 is a schematic diagram showing that metal is vacuum-deposited onto the surface layer 10 to form metal island structures 31, which then continuously form a metal layer 30 on a plane. The sea structure during vacuum deposition is the surface layer 10 where no metal is attached. It is preferable that the metal layer has a sea-island structure in which metal particles are separated from each other and have gaps, as this prevents whitening and maintains metallic luster even when deep drawing is performed to form a three-dimensional object. Figure 3 shows a state in which an adhesive layer 50 is further formed on the metal layer 30.

[0043] The thickness of the metal layer is not particularly limited, but a larger lower limit is preferable for the expression of design properties due to the reflected light of the metal layer, and a thickness of 5 nm or more is preferable, more preferably 10 nm or more, even more preferably 20 nm or more, and even more preferably 30 nm or more, in order to reduce the fading of the metal layer over time. A smaller upper limit is preferable for the expression of design properties due to the transmitted light of the laminate 9 and for improving millimeter-wave transmittance, a thickness of 200 nm or less is preferable, more preferably 150 nm or less, even more preferably 120 nm or less, and even more preferably 100 nm or less.

[0044] To balance the aforementioned effects, the wavelength is preferably 5 nm to 200 nm, more preferably 10 nm to 150 nm, even more preferably 20 nm to 120 nm, and even more preferably 30 nm to 100 nm.

[0045] 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.

[0046] <Surface layer> The aforementioned surface layer must contain a polyurethane resin.

[0047] The surface layer is preferably a layer that is on the observer's side of the metal layer when the article is made to resemble a metal. The surface layer is preferably transparent so that the metal layer is visible, has scratch resistance and weather resistance, and can withstand the temperatures when the article is formed to resemble a metal. The total light transmittance, as a guideline for transparency, is preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more. There is no particular upper limit as long as the design is aesthetically pleasing, but it is preferably 100% or less, although it is generally 96% or less.

[0048] The surface layer may contain various dyes and pigments to adjust transparency and color tone, and may also be dyed with dyes. Furthermore, the surface layer may have a desired print applied beforehand. Polycarbonate resin is a flame-retardant resin and has high transparency, so it does not interfere with the expression of the design by the metal layer. In addition, it has excellent scratch resistance, and degradation by UV light and oxygen is suppressed, and deterioration of the design due to yellowing etc. is suppressed, so it is preferable.

[0049] As will be explained in more detail later, the surface layer can be obtained by laminating it on the protective layer described later, and then laminating a metal layer on top of it, and it serves to hold the metal layer in place.

[0050] The thickness of the surface layer can be a thickness typical for decorative sheets, but to improve scratch resistance and suppress the occurrence of defects such as wrinkles during lamination, it is preferable to have a thickness of at least the lower limit, to suppress fracture of the metallic decorative laminate during molding and to improve the formability of the metallic decorative laminate, and is preferably 20 μm to 500 μm, more preferably 50 μm to 300 μm, even more preferably 80 μm to 200 μm, and even more preferably 100 μm to 150 μm.

[0051] The polyurethane resin is preferably a polycarbonate-based polyurethane resin.

[0052] <<Polycarbonate-based polyurethane resin>> The aforementioned polycarbonate-based polyurethane is a reaction product of a polycarbonate-based polyol and a polyisocyanate compound, and is a resin with a carbonate group as its main backbone, where the polycarbonate exhibits flame retardancy and the polyurethane exhibits hardness.

[0053] The polycarbonate-based polyurethane resin is preferably a cured product containing thermosetting polycarbonate-based polyurethane and carbodiimide, and more preferably contains a silicone-based surfactant.

[0054] (Thermosetting polycarbonate-based polyurethane) This is a polyurethane that polymerizes and hardens upon heating. For example, it is a dried and cured product obtained by the evaporation of the solvent in a thermosetting polycarbonate-based polyurethane dispersion and further polymerization and hardening upon heating.

[0055] (Carbodiimide) It is preferable to include carbodiimide in polycarbonate-based polyurethane resin because it can improve the weather resistance of the polycarbonate-based polyurethane resin.

[0056] Furthermore, including carbodiimide can improve the chemical resistance of polycarbonate-based polyurethane resins.

[0057] As the carbodiimide, it is preferable to use one that is compatible with thermosetting polycarbonate-based polyurethane. Using a carbodiimide compatible with both resins is preferable because it improves the total light transmittance of the metallic decorative laminate. As such a compatible carbodiimide, for example, a polycarbodiimide having carbodiimide groups in its molecule can be used.

[0058] As the mixture of thermosetting polycarbonate polyurethane and carbodiimide dries and hardens to form the surface layer, the metallic decorative laminate will have superior design, scratch resistance, weather resistance, millimeter-wave transmittance, and moldability, at least two of these properties.

[0059] (Mass ratio of polyurethane to carbodiimide) If the amount of carbodiimide is too small, the effect of improving chemical resistance such as alkali resistance may not be achieved, and if the amount of carbodiimide is too large, it may inhibit the properties of polyurethane and reduce chemical resistance such as alkali resistance. From the above viewpoint, it is preferable that the amount of carbodiimide be 0.30 parts by mass or more and 0.95 parts by mass or less, and more preferably 0.40 parts by mass or more and 0.90 parts by mass or less, per 10 parts by mass of the total resin components of the thermosetting polycarbonate polyurethane.

[0060] When the aforementioned surface layer is used as the outermost surface of a metallic decorative laminate, the surface may be given various patterns by embossing or other processes as needed, or a matte finish may be given by creating fine irregularities. Alternatively, a hairline finish may be applied to give a hairline-like design.

[0061] <Base material layer> The aforementioned substrate layer must contain a polycarbonate resin. It is sufficient that it contains a polycarbonate resin; generally available polycarbonate resin films can be used.

[0062] The base material layer may be in direct contact with the metal layer, or it may be bonded to the metal layer via an adhesive layer as described later.

[0063] Furthermore, the thickness of the base layer may be any thickness typical for a metallic decorative laminate. In order to suppress the occurrence of defects such as wrinkles during film formation and to suppress the breakage of the metallic decorative laminate during the molding process of the metallic article, it is preferably 10 μm to 1000 μm, more preferably 50 μm to 700 μm, even more preferably 100 μm to 500 μm, and even more preferably 150 μm to 300 μm.

[0064] The substrate layer is preferably highly transparent from the viewpoint of millimeter-wave transmittance. As a guideline for transparency, the total light transmittance is preferably 85% or higher, more preferably 88% or higher, and even more preferably 90% or higher. There is no particular upper limit as long as the design is aesthetically pleasing, but it is preferably 100% or less, although it is generally 96% or less.

[0065] <<Other layers>> The aforementioned metallic decorative laminate may further include other layers.

[0066] The aforementioned other layers may include, as necessary, an adhesive layer, a transparent resin layer, a primer layer, and the like.

[0067] The aforementioned other layers are preferably highly transparent from the viewpoint of millimeter-wave transmittance. As a guideline for transparency, the total light transmittance is preferably 85% or higher, more preferably 88% or higher, and even more preferably 90% or higher. There is no particular upper limit as long as the design is aesthetically pleasing, but it is preferably 100% or less, although it is generally 96% or less.

[0068] <<adhesive layer>> The adhesive layer is a layer containing a resin component that exhibits adhesive properties.

[0069] Preferably, the adhesive layer is a layer that exists between the metal layer and the substrate layer and is used to bond them together.

[0070] The adhesive layer may contain a dye. By including a dye, the color shift that occurs when light from the light source 7 shown in Figure 2 passes through the metal layer can be corrected.

[0071] The adhesive layer contains a resin component that exhibits adhesion, and it is preferable to use an adhesive that has excellent adhesion to the metal layer and the substrate layer. Examples of such adhesives include one or more resins selected from polyurethane, polyvinyl acetate, ethylene vinyl acetate copolymer, polyvinyl alcohol, epoxy, and silicone resins. For example, considering aesthetics, weather resistance, transparency, adhesion, and heat resistance to withstand molding temperatures, a polyurethane adhesive can be used.

[0072] The aforementioned urethane adhesive is a reaction product of a polyester diol, a polycarbonate diol, and an aliphatic isocyanate, and preferably contains a carbodiimide and a silane coupling agent having an epoxy group.

[0073] The method for forming the adhesive layer is not particularly limited. For example, the adhesive layer can be formed by applying an appropriate amount to the metal layer and / or substrate layer using a solvent as appropriate, or as an emulsion, by known means such as a gravure coater, reverse coater, knife coater, or roll coater, and drying as necessary.

[0074] The thickness of the adhesive layer can be a typical thickness for a metallic decorative laminate. For example, it is preferably 1 μm to 20 μm, more preferably 2 μm to 8 μm, and even more preferably 3 μm to 7 μm, considering aesthetics, weather resistance, adhesion, drying time, cost, etc.

[0075] (dye) The aforementioned surface layer, base layer, and / or other layers may contain pigments to the extent that the metallic decorative laminate exhibits the desired metallic design. The pigments are not particularly limited and may be dyes or pigments, inorganic compounds or organic compounds, natural pigments or synthetic pigments, as long as they absorb visible light. Synthetic pigments are particularly preferred when used outdoors and weather resistance is required. More specifically, preferred examples include inorganic pigments such as titanium white, zinc oxide, iron oxide, vermilion, ultramarine, cobalt blue, titanium yellow, lead yellow, and carbon black; organic pigments (including dyes) such as isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, induthlene blue RS, and aniline black; metallic pigments such as aluminum and brass; and pearlescent pigments made from foil powders such as titanium dioxide-coated mica and basic lead carbonate. Since the layers containing the pigments need to transmit the reflected light 6 from the metal layer, the coloring must be transparent.

[0076] The total pigment content in each layer may be determined as needed, but it is preferable that it be 3.0% by mass or less in each layer.

[0077] (Layer structure of metallic decorative laminate) Specific examples of the layered structure of a metallic decorative laminate include (1) and (2) below. Note that " / " indicates the boundary between each layer. Also, the right side of Figure 2 represents the observer 4 side, and the left side represents the light source 7 side. (1) Base layer / metal layer / surface layer (2) Base layer / adhesive layer / metal layer / surface layer

[0078] [Multilayer laminate] The multilayer laminate of this embodiment requires that a surface protection layer be further included on the side opposite to the metal layer of the surface layer of the metallic decorative laminate. Furthermore, it may be included on the side opposite to the metal layer of the base material of the metallic decorative laminate. If a release layer, as described later, is present between the base material layer and the surface protection layer, the adhesive layer may be included between the base material layer and the release layer.

[0079] <Surface protective layer> The aforementioned surface protection layer is a layer for protecting the surface of the metallic decorative laminate from dirt, scratches, etc., during storage and transportation. General-purpose films such as urethane resin, polyester resin, acrylic resin, acrylic urethane resin, and vinyl chloride-vinyl acetate copolymer resin can be used. When forming a surface layer on the surface protection layer, it is preferable to use ordinary polyethylene terephthalate resin (PET resin), such as APET resin or MPET resin. The thickness of the surface protection layer can be appropriately selected according to the requirements.

[0080] The multilayer laminate may further have a release layer between the metallic decorative laminate and the protective layer. The release layer in this disclosure is a layer provided to peel the protective layer from the metallic decorative laminate and is peeled off from the metallic decorative laminate together with the protective layer. A release agent is used in the release layer to improve its peelability. Preferred release agents include melamine resin-based release agents, silicone-based release agents, fluororesin-based release agents, cellulose resin-based release agents, urea resin-based release agents, polyolefin resin-based release agents, paraffin-based release agents, acrylic resin-based release agents, and composite release agents thereof, with silicone-based release agents being more preferred.

[0081] (Layer structure of a multilayer laminate) Specific examples of the lamination configuration of a multilayer laminate include (1) to (3) below. Note that " / " indicates the boundary between each layer. Also, the right side represents the observer 4 side in Figure 2, and the left side represents the light source 7 side. To clarify the direction of the metallic-finish laminate, "(substrate layer side)" and "(surface layer side)" are indicated. (1) Protective layer / (Substrate layer side) Metallic decorative laminate (Surface layer side) / Protective layer (2) (Base layer side) Metallic decorative laminate (Surface layer side) / Protective layer (3) Protective layer / (Substrate layer side) Metallic decorative laminate (Surface layer side)

[0082] [Metal-like articles] The metallic-looking article of this embodiment must include the metallic-looking decorative laminate.

[0083] The metallic articles of this embodiment are manufactured using the metallic decorative laminate by, for example, the manufacturing method described later, and are molded into a desired shape according to their purpose. For example, they 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 decorative and design features in place of plating or metal materials.

[0084] In particular, the metallic decorative laminate of this embodiment not only imparts a metallic design to an article, but also imparts chemical resistance and weather resistance to the article. In this disclosure, "article" refers to a precursor of a metallic article, which becomes a metallic article by being decorated with the decorative laminate.

[0085] The metallic-looking article of this embodiment may have other configurations in addition to the above-described configuration. For example, in order to keep the surface of the protective layer and base layer clean and prevent dirt from adhering until the metallic-looking article of this embodiment is used, a release paper or protective film may be included on the surface of the protective layer and base layer as a protective layer.

[0086] [Method for manufacturing a metallic-looking decorative laminate] The following describes, but is not limited to, the manufacturing method of the metallic decorative laminate.

[0087] The method for manufacturing the metallic decorative laminate preferably includes forming a surface layer on a protective layer, forming a metal layer on the surface layer, forming an adhesive layer on the metal layer, and adhering a base layer to the adhesive layer.

[0088] After applying a release agent to the protective layer as needed, a coating liquid for forming the surface layer is applied, dried, and then solidified to form the surface layer.

[0089] A metal layer is formed on the obtained surface layer. Methods for forming such a metal layer include vacuum deposition, sputtering, or ion plating, and the metal layer can be formed using conventional methods such as vacuum application technology.

[0090] The metal layer can be formed, for example, by vacuum deposition. This process is 1.33 × 10⁻⁶ -3 Pa or more 1.33×10 -2 Under pressure conditions below Pa, a surface layer along a roll with a temperature between -5°C and 5°C is exposed to an indium vapor stream to form a metal layer by depositing indium onto the surface layer. Indium is vaporized from an evaporation source crucible to generate an indium vapor stream. In this state, the indium vapor stream adheres to the surface of the surface layer, and the indium is cooled to form the metal layer. The thickness of the metal layer can be controlled by controlling the temperature of the vapor source crucible, the pressure inside the vacuum deposition apparatus, and the exposure time of the surface layer to indium vapor. The metal layer forms an indium island structure on the surface layer.

[0091] A coating liquid for forming an adhesive layer is applied to the metal layer, and after drying, it is bonded to a substrate layer (or the substrate layer and the adhesive layer if a protective layer is present) as needed. This bonding forms an adhesive layer between the metal layer and the substrate layer.

[0092] If necessary, the protective layer can be peeled off to produce the metallic decorative laminate of this embodiment. The coating liquid for forming the surface layer, the coating liquid for forming the adhesive layer, and the release agent may further contain the resin component, other components, and solvents mentioned above.

[0093] The aforementioned solvent can be any solvent that is generally used in the field in question. Possible solvents include polar solvents such as ester solvents, ether solvents, and ketone solvents; nonpolar solvents such as hydrocarbon solvents and aromatic solvents; and alcoholic solvents such as methanol, ethanol, and isopropyl alcohol. However, polar solvents such as ester solvents, ether solvents, and ketone solvents are preferred.

[0094] The coating can be applied to the substrate using known means such as a gravure coater, reverse coater, die coater, knife coater, or roll coater.

[0095] [Method for manufacturing metallic articles] A metallic-looking article using the aforementioned metallic-looking decorative laminate can be manufactured, for example, by the following method.

[0096] For example, the method for manufacturing the metallic article includes a molding step of bringing the metallic decorative laminate, whose surface temperature is 150°C or more and 200°C or less, into close contact with a mold to obtain a metallic article containing the metallic decorative laminate.

[0097] (molding process) To thermoform a metallic decorative laminate, setting the surface temperature of the metallic decorative laminate between 150°C and 200°C prevents drawdown and whitening during molding, thus satisfying good formability. A surface temperature of 150°C or higher allows the metallic decorative laminate to soften sufficiently, and the drawdown phenomenon causes it to sag and deform, facilitating processing and molding. Furthermore, a surface temperature of 200°C or lower prevents the metallic decorative laminate from becoming too soft and difficult to mold, and also prevents whitening from occurring.

[0098] The shape of the mold used to press the metallic decorative laminate can be any shape that allows the metallic article to be molded 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 that takes into account the control of the surface temperature of the metallic decorative laminate and the control of the cooling conditions of the metallic article after the molding process.

[0099] 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.

[0100] (Clamping process) The present invention's method for manufacturing a metallic-looking article may include a clamping step before the molding step, in which the metallic-looking decorative laminate is clamped. 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, such as 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. Typically, when continuously producing metallic-looking articles, both ends in the width direction of the metallic-looking decorative laminate can be gripped. Furthermore, when batch producing metallic-looking articles using rectangular pieces of metallic-looking decorative laminate cut to a predetermined length, the ends of all four sides can be gripped with upper and lower frames.

[0101] (Heating process) Furthermore, a method for manufacturing a metallic-looking 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 loosen, 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.

[0102] (Other processes) The manufacturing method for metallic articles 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 surface layer or base layer to maintain the surface of the metallic article in a clean state and prevent contamination until it is processed in the next step. Furthermore, after inserting the metallic article into an injection molding die, insert injection molding is performed by injecting resin, and the surface of the injection-molded article can be decorated.

[0103] Injection molding can be performed using a general-purpose injection molding machine. Polycarbonate, a thermoplastic resin, can be used as the resin. The polycarbonate can be melted and injected between the surface layer and the injection mold to form a resin layer.

[0104] Furthermore, the method for manufacturing an injection-molded article may include a trimming step in which a metallic-looking article is trimmed to an arbitrary shape before the injection molding step, a cooling step in which the molded product is cooled after the injection molding step, and a removal step in which the molded product is removed from the injection molding die after the cooling step.

[0105] The metallic decorative laminate of this embodiment, as well as the multilayer laminate and metallic article including the metallic decorative laminate, are preferably as described below [1] to [6]. [1] Surface layer and, Metal layer, The base layer and the following are included in this order: The aforementioned surface layer contains a polyurethane resin, A metallic decorative laminate in which the base layer contains a polycarbonate resin. [2] The metallic decorative laminate according to [1], further comprising an adhesive layer between the metal layer and the base material layer. [3] The metallic decorative laminate according to [1] or [2], wherein the metal layer contains indium. [4] A metallic decorative laminate according to any one of [1] to [3], wherein the total light transmittance of light irradiated from the surface layer side is 30% or less, and the reflectance of the specular reflection component of light irradiated from the substrate layer side is 20% or more. [5] A multilayer laminate comprising a metallic decorative laminate according to any one of [1] to [4], further including a surface protective layer on the side opposite to the metal layer of the surface layer. [6] A metallic-looking article comprising a metallic-looking decorative laminate as described in any one of [1] to [4]. [Examples]

[0106] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited in any way to the following examples.

[0107] (Evaluation method) 1.Total light transmittance The total light transmittance of the metallic decorative laminate was measured using a spectrophotometer (Hitachi High-Tech Science Corporation, UH4150) with light at a measurement wavelength of 380 nm to 780 nm, in accordance with JIS K7375:2008. The measured values ​​include a measurement error of 2% or less.

[0108] 2. Reflectance of the specular reflection component (specular reflectance) The specular reflectance of a metallic decorative laminate was measured by irradiating it with light of wavelengths from 380 nm to 700 nm using a Konica Minolta CM3600A from the substrate layer side. The measured values ​​include a measurement error of 10% or less.

[0109] 3. Evaluation of scratch resistance The surface of the surface layer of the metallic decorative laminate was used as the test surface, and gauze (manufactured by Hakujuji Co., Ltd., corresponding to Kanakin No. 3) was wrapped around a 15mm diameter terminal according to the conditions of European automotive standard TL226. The attached material was pressed against the surface layer 10 with a load of 900g, and the pressed gauze was moved back and forth 2000 times at a stroke of 10cm and 60 back-and-forth movements per minute.

[0110] The total light transmittance was measured using the metallic decorative laminate treated with the aforementioned gauze, and the scratch resistance was evaluated as follows based on the difference in total light transmittance before and after treatment with the gauze. Table 2 shows the values ​​of total light transmittance after treatment with the gauze. A: The difference in total light transmittance before and after treatment with gauze is less than 1 point (pass). B: The difference is between 1 point and less than 3 points (fail). C: The difference mentioned above is 3 points or more (fail).

[0111] 4. Heat cycle test (heat cycle) The samples were subjected to a cycle test by placing them in an environment with varying temperatures according to the following cycles. After the cycle test, an adhesion test was performed using the method described below. It was confirmed that there were no changes in appearance and no defects such as sheet peeling. The evaluation was categorized as A to C below. A: If there was no delamination of the grid (0 / 100), and the presence or absence of surface changes such as clouding was checked through visual evaluation, the material was considered to have very good heat cycle resistance if there were no surface changes. B: Heat cycle resistance was defined as the absence of delamination of the grid (0 / 100) and only slight surface changes being observed. C: Heat cycle resistance was deemed to be lacking if there was delamination of the grid pattern or if significant surface changes were observed.

[0112] The heat cycle was performed as follows: -30°C (7.5 hours) → 25°C (0.5 hours) → 80°C (15.5 hours) → 25°C (0.5 hours) → -30°C (7.5 hours) → 25°C (0.5 hours) → 50°C·95%RH (15.5 hours) → 25°C (0.5 hours), and this cycle was repeated 8 times.

[0113] The adhesion test was conducted based on the grid test of JIS K 5600. Nichiban tape cut into 100 grids at 2 mm intervals was used.

[0114] 5. Millimeter wave transmission The millimeter-wave transmission attenuation at a frequency of 76.5 GHz in a metallic decorative laminate was measured using a KEYCOM RAS (SM5899). The metallic decorative laminate was set in the apparatus so that millimeter waves were transmitted from the base layer side of the metal layer. Measurements were performed 250 times, and the average of the absolute values ​​of the 250 measurements was taken as the transmission attenuation (dB). Millimeter-wave transmittance was evaluated using the following A to C criteria. A: 2dB or less is excellent. B: Less than 5dB - A level that does not pose any practical problems. C: 5.00 dB or higher - Insufficient millimeter-wave transmission.

[0115] 6. Evaluation of design aesthetics The metallic decorative laminates obtained in the examples and comparative examples were observed visually from the surface layer side for reflected light, and the transmitted light from the substrate layer side was also observed visually from the surface layer side. The aesthetic appeal was evaluated as A or C below. A: It exhibits excellent design. C: The intended design aesthetic has not been achieved.

[0116] 7. Evaluation of moldability For each example and comparative example, the metallic-looking articles created using the metallic-looking decorative laminates were evaluated as having A or C in terms of moldability by visual inspection of the presence or absence of clouding in the stretched portion of the laminate (200% stretched before stretching) at the corner of the mold after the molding process. A: No clouding is observed, and no cracks or tears are seen. C: Cloudiness is observed, or cracks or tears have occurred.

[0117] (Materials used) 1. Protective layer and surface layer A protective layer (PET film G2000 (manufactured by Toyobo Co., Ltd.), layer thickness: 50 μm) was coated with a surface layer forming solution (a surface layer forming solution was obtained by mixing 21 g of aqueous polyurethane dispersion (UW5002 (manufactured by UBE Corporation)), 9 g of aqueous polyurethane dispersion (UW5502 (manufactured by UBE Corporation)), 0.3 g of silicone-based surfactant (BYK-345 (manufactured by BYK Corporation)), and 6 g of water). The solution was then dried at 150°C for 3 minutes to obtain a protective layer having a surface layer (layer thickness: 20 μm).

[0118] 2. Polycarbonate film (base layer) PC-11FU (Waverock Advanced Technology Co., Ltd.) Layer thickness: 500μm

[0119] 3.Coating liquid for adhesive layer formation Main ingredient: TM-K51 (manufactured by Toyo Morton Co., Ltd.), polyol component 14.25g Hardener: CAT-RT85 (manufactured by Toyo Morton Co., Ltd.), 3.21g in isocyanate equivalent Polycarbonate diol: T5652 (Asahi Kasei Corporation), 0.75g Adhesion modifier: KBM403 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.50g Carbodiimide: V-07 (manufactured by Nisshinbo Chemical Co., Ltd.), 0.17g Solvent: Ethyl acetate, 11g

[0120] (Example 1) Indium was deposited onto the surface layer of the protective layer having the aforementioned surface layer by vacuum deposition to perform a dry coating with a light transmittance of 12%. The adhesive layer forming coating liquid was applied to the resulting metal layer using a die coater to a dry film thickness of approximately 10 μm. After drying the coated material at 80°C for 2 minutes, the metal layer and the polycarbonate film were laminated together. The material was then cured at room temperature for 5 days and at 40°C for 5 days. After that, the protective PET layer was peeled off to produce a metallic decorative laminate (1). The layer structure is shown in Table 1.

[0121] Using the aforementioned metallic decorative laminate (1), a compression molding machine was used to clamp the metallic decorative laminate (1) to a test mold so that the base material layer of the metallic decorative laminate (1) faced the article side. Then, with a pre-forming temperature of 200°C and a compressed air pressure of 6 bar, the metallic decorative laminate (1) was preformed to fit the mold for injection molding. Unnecessary parts that protruded from the mold were trimmed off to produce a metallic article (1) with the surface layer being the outermost surface.

[0122] The manufactured metallic decorative laminate (1) and metallic article (1) were evaluated for total light transmittance, specular reflectance, scratch resistance, heat cycle test, millimeter wave transmittance, design evaluation, and moldability evaluation, and the results are shown in Table 2 along with the comparative examples.

[0123] (Comparative Example 1) Using the metallic decorative laminate (1) manufactured in Example 1, a metallic article (2) was produced with a polycarbonate film as the surface layer, and the outermost surface being a polycarbonate film. The layer configuration is shown in Table 1.

[0124] (Comparative Example 2) In Example 1, the protective layer having the surface layer was made using the PET film, and indium was deposited onto the surface layer of the PET film by vacuum deposition to perform a dry coating with a light transmittance of 16%. The adhesive layer forming solution was applied to the resulting metal layer with a die coater to a dry film thickness of approximately 10 μm, and after drying the coated material at 80°C for 2 minutes, the metal layer and the polycarbonate film were laminated together. Thereafter, the material was cured at room temperature for 5 days and at 40°C for 5 days to produce a metallic decorative laminate (2). The layer structure is shown in Table 1.

[0125] Using the aforementioned metallic decorative laminate (2), a compression molding machine was used to clamp the metallic decorative laminate (2) to a test mold so that the polycarbonate film of the metallic decorative laminate (2) would face the article side. Then, with a pre-forming temperature of 200°C and a compressed air pressure of 6 bar, the metallic decorative laminate (2) was preformed to fit the mold for injection molding. Unnecessary parts that protruded from the mold were trimmed off to produce a metallic article (3) with the aforementioned surface layer as the outermost surface.

[0126] [Table 1]

[0127] [Table 2]

[0128] Based on the results of Example 1 shown in Table 2, the metallic decorative laminate of the present disclosure and the metallic decorative laminate using the same The article was found to have excellent moldability, superior millimeter-wave transmission, scratch resistance, and aesthetic appeal.

[0129] In contrast, the metallic decorative laminates of Comparative Examples 1 and 2, and the metallic articles using them, were found to be significantly inferior in terms of scratch resistance.

[0130] (Example 2) In the same manner as in Example 1, a metallic decorative laminate (2) was manufactured, except that 2.0 parts by mass of black pigment (MHI Black #C004 (manufactured by Mikuni Pigment Co., Ltd.)) was added to the adhesive layer forming coating liquid when the adhesive layer forming coating liquid was 100 parts by mass. Furthermore, a metallic article (2) was manufactured using the metallic decorative laminate (2).

[0131] These materials were found to possess excellent scratch resistance and moldability, similar to the aforementioned metallic decorative laminate (1) and metallic article (1). Furthermore, unlike the metallic decorative laminate (1), it was confirmed that a metallic black design was produced.

[0132] (Example 3) A primer layer was further formed on the surface layer of the protective layer having the surface layer used in Example 1. Indium was deposited on the primer layer by vacuum deposition in the same manner as in Example 1 to form a metal layer. A metallic decorative laminate (3) was then manufactured in the same manner as in Example 1. A metallic article (3) was then manufactured using the metallic decorative laminate (3).

[0133] The metallic decorative laminate (3) showed even better results than the metallic decorative laminate (1) in the heat cycle test. [Industrial applicability]

[0134] The metallic decorative laminates and metallic articles of this embodiment have excellent formability, superior millimeter-wave transmittance, scratch resistance, and design appeal, making them suitable for use in automobiles, home appliances, information terminals, and the like. [Explanation of Symbols]

[0135] 1: Metallic decorative laminate 2: Metal laminate 3: Multilayer laminate 4: Observer 5: Outdoor light 6: Metal layer reflected light 7:Light source 8: Irradiation light 9: Transmitted light from the laminate 10: Surface layer 30: Metal layer 31: Metal island structure 50: Adhesive layer 60: Base material layer 70:Protective layer 71:Protective layer 100: Thickness direction 110: Width direction 120: Longitudinal direction

Claims

1. The surface layer and Metal layer, The base layer and the following are included in this order: The aforementioned surface layer contains a polyurethane resin, The aforementioned substrate layer contains a polycarbonate resin, A metallic decorative laminate in which the total light transmittance of light irradiated from the surface layer side is 30% or less.

2. The metallic decorative laminate according to claim 1, further comprising an adhesive layer between the metal layer and the substrate layer.

3. The metallic decorative laminate according to claim 1 or 2, wherein the metal layer contains indium.

4. The metallic decorative laminate according to claim 1 or 2, wherein the reflectance of the specular reflection component of light irradiated from the substrate layer side is 20% or more.

5. The metallic decorative laminate according to claim 1 or 2, wherein the thickness of the base layer is 10 μm or more and 1000 μm or less.

6. The metallic decorative laminate according to claim 1 or 2, wherein the polyurethane resin is a polycarbonate-based polyurethane resin.

7. A multilayer laminate comprising a metallic decorative laminate according to claim 1 or 2, further including a surface protective layer on the side of the surface layer opposite to the metal layer.

8. A metallic article comprising a metallic decorative laminate according to claim 1 or 2.

Images