Metallic decorative sheet and metallic decorative molded body including the same

Abstract

Provided are a metal tone decorative sheet having an excellent metallic luster and electromagnetic wave transmission properties, and a metal tone decorative molded body provided with the decorative sheet. A metal tone decorative sheet having a metal layer on a substrate layer, wherein: the metal layer has a plurality of island parts containing metal, and a sea part located between the island parts; the island parts are shaped as convex quadrilaterals in cross-sectional view; one side of the quadrilaterals face the substrate layer; and when the length of the substrate-layer-side side of the island parts is represented by x[nm] and the length of the side of the island parts on the opposite side from the substrate layer is represented by y[nm], 0 ≤ x - y ≤ 80 is satisfied.

Description

[Technical field]

[0001] The present invention relates to a metallic decorative sheet and a metallic decorative molded article including the same. [Background technology]

[0002] Conventionally, in order to improve the design of a molded product, a metallic luster has been imparted to the surface of the molded product. As a means for imparting a metallic luster, a method is known in which a decorative sheet having a metallic luster is placed in a mold, and a resin is injection-molded into the mold to adhere a metal vapor deposition sheet to the molded product (for example, Patent Document 1).

[0003] In particular, decorative sheets with vapor-deposited films of indium or tin can transmit electromagnetic waves with radar wavelengths such as millimeter waves. Taking advantage of this property, the decorative film is applied to emblems of vehicles equipped with collision prevention radar, handles equipped with sensors for locking and unlocking vehicle doors, and the like (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5809768 [Patent Document 2] Patent No. 2016-65297 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] In Patent Document 2, the average area of ​​the deposited indium particles is specified so that the indium deposition film has a desired hue from the viewpoint of the viewer's visual sense. However, no consideration is given to the metallic luster. For this reason, it is difficult to obtain the desired metallic luster.

[0006] An object of the present invention is to provide a metallic decorative sheet having a desired metallic luster and a metallic decorative molded body including the decorative sheet. **Means for Solving the Problems**

[0007] As a result of studies by the inventors of the present application, in a metal layer having a so-called "sea-island structure" including a plurality of island portions and a sea portion between the island portions, the cross-section of the island portion becomes a convex quadrilateral such as a rectangle or a trapezoid. Further, it has been found that the reflectance of the metallic decorative sheet changes greatly depending on the difference between the length of the side on the base material layer side and the length of the side opposite to the base material layer, and thus it is necessary to appropriately control the shape of the island portion.

[0008] That is, in order to solve the above problems, the present invention provides the following [1] to [8]. [1] A metallic decorative sheet having a metal layer on a base material layer, wherein the metal layer includes a plurality of island portions containing a metal and a sea portion located between the island portions, and the island portions are convex quadrilaterals when viewed in cross-section. One side of the quadrilateral faces the base material layer, and when the length of the side of the island portion on the base material layer side is x [nm] and the length of the side of the island portion opposite to the base material layer is y [nm], 0 ≦ x - y ≦ 80. A metallic decorative sheet. [2] The metallic decorative sheet according to [1], having a reflectance of 60% or more at a wavelength of 550 nm. [3] Further including an adhesive layer on the metal layer side opposite to the base material layer, a part of the adhesive layer is filled in the sea portion, and the x [nm] and the y [nm] satisfy 0 <x - y ≦ 80 nm. The metallic decorative sheet according to [1] or [2]. [4] The metallic decorative sheet according to [3], wherein the x [nm] and the y [nm] satisfy 10 ≦ x - y ≦ 80 nm. [5] The metallic decorative sheet according to any one of [1] to [4], wherein the area ratio of the sea portion when the metal layer is viewed in plan is 10% or more and 25% or less. [6] The metallic decorative sheet according to any one of [1] to [5], wherein, assuming that each of the island portions is circular, and the size of the island portions is defined as the average diameter calculated from the area of ​​each of the island portions, the size is 100 nm or more and 300 nm or less. [7] The metallic decorative sheet according to any one of [1] to [6], wherein the metal layer contains indium or tin.

[0009] [8] A metallic decorative formed body comprising the metallic decorative sheet according to any one of [1] to [7] and an adherend. Effect of the Invention

[0010] According to the present invention, it is possible to obtain a metallic decorative sheet having a desired metallic luster, and a metallic decorated molded body including the decorative sheet. [Brief description of the drawings]

[0011] [Figure 1] 1 is a scanning electron microscope photograph of a cross section of the metallic decorative sheet of Example 1. [Diagram 2] 1 is a scanning electron microscope photograph of the metal layer surface of the metallic decorative sheet of Example 1. [Diagram 3] 11 is a diagram for explaining a cross-sectional shape of an island portion. FIG. [Figure 4] 13 is a diagram for explaining lengths x and y of the sides of the island portion. FIG. [Diagram 5] FIG. 2 is a schematic diagram of a Gravello test device for evaluating the chipping resistance of the decorated molded bodies obtained in the Examples and Comparative Examples. [Figure 6] 1 is a scanning electron microscope photograph of a cross section of the metallic decorative sheet of Comparative Example 1. [Figure 7] FIG. 13 is a diagram for explaining a thin-line model used in the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The metallic decorative sheet and metallic decorative molded article of the present invention will be described in detail below. In this specification, the numerical range of "AA to BB" means "AA or more and BB or less".

[0013] [Metallic decorative sheet] The metallic decorative sheet of the present invention is a metallic decorative sheet having a metal layer on a base layer, the metal layer having a plurality of island portions containing metal and a sea portion located between the island portions, the island portions being convex quadrangles when viewed in cross section, one side of the quadrangle facing the base layer, the length of the side of the island portion on the base layer side being x [nm], and the length of the side of the island portion opposite the base layer being y [nm], where 0≦xy≦80.

[0014] The metal layer in the metallic decorative sheet of the present invention has an "island-sea structure" having a plurality of islands containing metal and a sea portion located between the islands. An example is the structure shown in FIG. 2, in which a plurality of islands are densely packed and the islands are separated by the sea portion. The structure shown in FIG. 2 can be seen when the metallic decorative sheet is observed from the metal layer side with a scanning electron microscope. The metallic layer having the island-sea structure can provide a metallic decorative sheet with a metallic gloss.

[0015] [Cross-sectional shape of island part] In the present invention, the cross-sectional shape of the island portion can be confirmed from an electron microscope image. First, the metallic decorative sheet is embedded in a resin. The resin is used to fix the metallic decorative sheet and obtain a sharp cross section when cutting the metallic decorative sheet in the lamination direction for cross-sectional observation. For example, a thermosetting resin made of a mixture of epoxy phenol novolac and imidazole can be used as the resin.

[0016] Next, the metallic decorative sheet provided with the resin layer is cut in the lamination direction (a direction substantially perpendicular to the plane of the base layer). The cut surface is observed with an electron microscope under the following conditions to obtain an image. <Cross-section observation conditions> Equipment: Scanning electron microscope Observation conditions Acceleration voltage: 3 kV Emission current: 10μA Pixel size: 0.9~1.0nm Working distance: 3.5mm Magnification: 50,000x Gradation: 8-bit

[0017] FIG. 1 is an example of an image obtained by observing, with an electron microscope, a cross section of a two-layer metallic decorative sheet in which a metal layer is formed on a base layer. In the present invention, the metal layer has a rectangular shape with the island portion being convex when viewed in cross section. Usually, the corners of the island portion on the side opposite the substrate layer are observed as curved surfaces. Also, the edges of the corners may be observed to be higher than the center of the island portion. In such cases, the shape is also referred to as a "rectangle" in the present invention as an approximation.

[0018] FIG. 3 shows an example of a suitable shape of the island portion when viewed in cross section. The island portion A has a rectangular cross section. One side a of the rectangular island portion A is located on the substrate layer side and faces the substrate layer. In FIG. 3, the entire side a contacts the substrate layer. In addition, when another layer (e.g., a primer layer) is formed between the substrate layer and the metal layer as described later, the entire side a contacts the layer adjacent to the metal layer among the layers.

[0019] The cross section of the island B is a trapezoid. One side b of the trapezoid island B is located on the substrate layer side and faces the substrate layer. In FIG. 3, the entire side b contacts the substrate layer. In addition, when another layer (e.g., a primer layer) is formed between the substrate layer and the metal layer as described later, the entire side b contacts the layer adjacent to the metal layer among the layers. In the present invention, the island B is preferably a trapezoid in shape in which the extension lines of the two oblique sides intersect on the metal layer side. In addition, the island B is preferably shaped such that when a perpendicular line is drawn from the end opposite the substrate layer to the substrate layer side, the perpendicular line intersects with the side b in both of the two oblique sides (see FIG. 3).

[0020] The cross section of the island C is a rectangle in which none of the opposing sides are parallel. One side c is located on the substrate layer side and faces the substrate layer. In FIG. 3, side c is in contact with the substrate layer as a whole. Note that, as described below, when another layer (e.g., a primer layer) is formed between the substrate layer and the metal layer, side c is in contact with the layer adjacent to the metal layer among the layers. In addition, it is preferable that the island C has a shape such that, when a perpendicular line is drawn from the end opposite the substrate layer to the substrate layer side, the perpendicular line intersects with side c on both of the two oblique sides (see FIG. 3).

[0021] Here, the sides (sides a, b, and c in FIG. 3) that come into contact with the base layer (or the layer between the base layer and the metal layer) are referred to as "sides on the base layer side". For each island in the cross-sectional image obtained by the above-mentioned means, the length x [nm] of the side on the base material layer side and the length y [nm] of the side opposite the base material layer are calculated. The lengths x and y are calculated according to the definitions shown in Fig. 4. Fig. 4 shows the case of an island shape with curved corners. The length x of the side on the base layer side corresponds to the distance between both ends where the island portion and the base layer are in contact. The length y of the side on the opposite side to the base layer is calculated by the following methods (i) to (iii). (i) In the cross-sectional image, a line is drawn that overlaps with the extending direction of the center part of the island on the side opposite to the base material layer and is longer than the center part. The extending direction of the center part of the island is the extending direction of the side opposite to the base material layer in the case of islands A to C in FIG. 3. (ii) In the cross-sectional image, the starting points where the island separates from the line in both end regions of the island are defined as "corners." (iii) The distance between the corners on the line is defined as the "side opposite to the base layer," and its length y is measured on the image.

[0022] If the island has a shape in which the periphery of the corner is higher than the center of the island, calculation is performed using the following methods (iv) to (vi) based on the same concept as in FIG. (iv) In the cross-sectional image, a line is drawn that overlaps with the central portion of the island portion (corresponding to the flat portion) on the side opposite to the base layer and is longer than the central portion. (v) In the cross-sectional image, the intersections of the line and the slopes of the island in both end regions of the island are defined as "corners." (vi) The distance between the corners on the line is defined as the "side opposite to the base layer," and its length y is measured on the image.

[0023] In the present invention, the side length x [nm] and the side length y [nm] of the island portion satisfy the relationship of formula (1). 0≦xy≦80 …(1) The relationship 0≦xy includes cases where the cross section of the island is rectangular. Furthermore, when the cross section of the island is a trapezoid or a square as shown in Fig. 3, this means that the side on the base layer side is longer. In other words, when viewed stereoscopically, the island has a columnar or frustum shape with the bottom surface in contact with the base layer. The relationship of xy≦80 means that the cross section of the island is a trapezoid or a rectangle as shown in FIG. 3, and the difference between the lengths of the upper and lower bases is small (closer to a rectangle). A large xy means that the side of the island opposite to the base layer is short, and the island is closer to a triangle when the metal layer is viewed in cross section. In the case of such a shape, when the metal layer is viewed in plan, the area of ​​the (peripheral part) corresponding to the slope of the side of the frustum-shaped island becomes large. This peripheral part is thinner than the center part of the island, so incident light may be transmitted through it. The larger the area of ​​the peripheral part, the greater the amount of transmitted light. Therefore, the larger xy, the lower the reflectance tends to be. The cross-sectional shape of the island is in the relationship of formula (1), and thus a metallic decorative sheet having a desired reflectance is obtained. Considering the reflectance, xy is preferably 60 nm or less, and more preferably 40 nm or less. It is particularly preferable that the cross section of the island is close to a rectangle (i.e., xy is close to 0 nm).

[0024] Furthermore, the lower limit of xy is preferably larger than 0, more preferably 5 nm or more, and particularly preferably 10 nm or more. When xy is in the above range, the side of the cross section of the island portion becomes an oblique side. Therefore, as described later, when forming an adhesive layer on the metal layer for adhesion to the adherend, the resin for the adhesive layer is easily filled between the island portions (sea portion), and the interlayer adhesion between the metal layer and the adhesive layer is improved. When a metallic decorative molded body in which a metallic decorative sheet and an adherend are attached with an adhesive layer is used for the exterior of a vehicle body such as an automobile, peeling of the surface layer (also called chipping) due to flying stones while the vehicle body is running may occur. By improving the interlayer adhesion between the metal layer and the adhesive layer, chipping can be suppressed. In particular, by satisfying 10 nm≦xy, chipping resistance can be further improved.

[0025] The difference (xy) between the length x of the side of the island on the substrate layer side and the length y of the side opposite the substrate layer can be adjusted by changing the wettability of the metal layer with the surface on which the metal layer is formed, as well as the deposition time of the metal layer and the substrate temperature during deposition. For example, to make the cross-sectional shape of the island closer to a rectangle, the metal layer is formed on a surface that has poor wettability with the metal layer. On the other hand, the better the wettability with the metal layer, the larger xy becomes. Examples of the surface on which the metal layer is formed include a substrate layer and a primer layer, as described below. In the present invention, the wettability can be changed and the difference in length (xy) between the island portions can be adjusted according to the material of the metal layer by changing the material of the substrate layer and the primer layer, or by subjecting the surface on which the metal layer is formed to a physical or chemical surface treatment.

[0026] In the present invention, the difference in length (xy) is calculated for each island portion. For each island portion that can be confirmed in the observed cross-sectional image, the lengths x and y are measured and the difference in length (xy) is calculated. Furthermore, cross-sectional observation is performed on 20 points within the plane of the metal layer of the metallic decorative sheet, and the difference in length (xy) is calculated. It is preferable that the average of the obtained length differences satisfies formula (1).

[0027] [Reflectance of metallic decorative sheet] The metallic decorative sheet of the present invention preferably has a reflectance of 60% or more. By making the reflectance 60% or more, it is possible to obtain a metallic decorative sheet having a reflectance equivalent to that of a film having a known metallic luster such as chrome plating. The reflectance is preferably 61% or more, more preferably 62% or more. In the present invention, the reflectance is a value when light having a wavelength of 550 nm is incident from the base layer side at an incident angle of 5 degrees. The reflectance can be measured using a spectrophotometer.

[0028] [Example of layer structure of metallic decorative sheet] Specific examples of the metallic decorative sheet include the following structures (1) to (8), in which " / " indicates the boundary between layers. (1) Base material layer / metal layer / adhesive layer (2) Base layer / metal layer / adhesive layer / peeling layer (3) Base layer / primer layer / metal layer / adhesive layer (4) Base layer / primer layer / metal layer / adhesive layer / peeling layer (5) Base layer / metal layer / adhesive layer / backer layer (6) Base layer / primer layer / metal layer / adhesive layer / backer layer (7) Base layer / metal layer / adhesive layer / backer layer / adhesive layer (8) Base layer / primer layer / metal layer / adhesive layer / backer layer / adhesive layer The structure of each layer will be described in detail below.

[0029] <Base material layer> The substrate layer serves as a support for the metallic decorative sheet. In addition, the substrate layer is preferably disposed on the outermost side when the decorative molding is formed. Therefore, the substrate layer serves to impart scratch resistance to the metallic decorative sheet and the metallic decorative molding. In this case, it is preferable that the substrate layer has transparency from the viewpoint of being able to visually confirm the metal layer.

[0030] As the base layer, it is preferable to use a plastic film containing a resin such as a polyolefin resin such as polyethylene or polypropylene, a vinyl resin such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, or ethylene-vinyl alcohol copolymer, a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, or polybutylene terephthalate, an acrylic resin such as polymethyl (meth)acrylate or polyethyl (meth)acrylate, a styrene resin such as polystyrene, a polyamide resin represented by nylon 6 or nylon 66, or an ABS resin (acrylonitrile-styrene-butadiene copolymer resin). Among these, it has excellent weather resistance and moldability, and has a low refractive index, making it highly transparent. Acrylic resins are suitable because scratches are less noticeable. In addition, when an indium vapor deposition film or a tin vapor deposition film is directly formed on a base layer as a metal layer, selecting an acrylic resin or an olefin resin for the base layer makes it easier for the islands of the metal layer to satisfy formula (1).

[0031] The resin component forming the base layer may be one type or a mixture of two or more types. The base layer may be formed of a single layer film of these resins, or may be formed of a multilayer film of the same or different resins, but is preferably formed of a single layer film. In the present invention, "(meth)acrylic" is a general term for "acrylic" and "methacrylic", and other similar substances with (meth) attached have the same meaning.

[0032] The substrate layer may be subjected to physical or chemical surface treatment such as oxidation or roughening on one or both sides as necessary in order to adjust the adhesion and wettability with the metal layer and the primer layer described later. Examples of the oxidation method performed as the surface treatment of the substrate layer include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone ultraviolet treatment. Examples of the roughening method performed as the surface treatment of the substrate layer include sandblasting and solvent treatment. These surface treatments are appropriately selected depending on the type of resin component constituting the substrate layer, but from the viewpoint of effect and operability, a corona discharge treatment is preferably used. When an indium vapor deposition film is directly formed on the substrate layer as the metal layer, the island part of the metal layer can easily satisfy formula (1) by performing the surface treatment in this way.

[0033] The substrate layer preferably has a haze according to JIS K7136:2000 of 5% or less, more preferably 3% or less, and even more preferably 1% or less. Furthermore, the substrate layer preferably has a visible light transmittance according to JIS K7361-1:1997 of 85% or more, and more preferably 90% or more.

[0034] The thickness of the base layer is appropriately set depending on the application of the metallic decorative sheet, but is usually about 50 to 250 μm, preferably about 60 to 150 μm, and more preferably about 70 to 125 μm. When the thickness of the base layer is within the above range, the metallic decorative sheet can be provided with even more excellent three-dimensional formability, designability, and the like.

[0035] <Primer layer> The primer layer is a layer that is provided as needed for the purposes of improving adhesion between the metal layer and a layer adjacent to the metal layer (e.g., a substrate layer) and suppressing deterioration of the metal layer due to components (e.g., chlorine components) contained in a layer adjacent to the metal layer. Furthermore, when the primer layer is used as a base for forming a metal layer by vapor deposition, the primer layer affects the cross-sectional shape of the island portion (particularly the values ​​of x and y) due to its wettability with the metal layer.

[0036] As the resin for the primer layer, resins such as acrylic resins, polyurethane resins, acrylic-urethane copolymer resins, and polyester resins can be used. From the viewpoint of easily satisfying formula (1) and improving adhesion to the metal layer, it is preferable that the primer layer contains an acrylic resin, a mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin, or an acrylic polyol and an isocyanate. In addition, by using these resins, the island part is easily formed into a frustum shape, and as described later, the resin for the adhesive layer is easily filled in the sea part, and further, the resin for the adhesive layer and the primer layer are well adhered to each other, so that the chipping resistance can be improved. In consideration of good adhesion to the metal layer and the adhesive layer, it is particularly preferable that the primer layer material contains an acrylic polyol and an isocyanate. The primer layer may contain additives such as an ultraviolet absorber and a light stabilizer.

[0037] The thickness of the primer layer is not particularly limited, but is usually about 0.5 to 2.5 μm, and preferably about 1 to 2 μm.

[0038] <Metal layer> The metal layer is provided on the base layer and provides the metallic luster to the metallic decorative sheet. The metal layer of the present invention has a sea-island structure having a plurality of islands containing metal and a sea portion located between the islands, as shown in Fig. 2. The metal layer having a sea-island structure can easily improve radio wave transmission. The metal layer of the present invention preferably has electromagnetic wave transparency that allows electromagnetic waves of radar wavelengths to pass through. Specifically, the transmittance of electromagnetic waves with a frequency of 76.5 GHz is preferably 90% or more, more preferably 93% or more. Also, the transmittance of electromagnetic waves with a frequency of 100 kHz is preferably 93% or more, more preferably 95% or more.

[0039] In the present invention, from the viewpoint of facilitating the formation of a sea-island structure by vapor deposition, the metal layer preferably contains at least one of indium, tin, gold, and an alloy thereof. The metal layer more preferably contains a metal having a melting point of 240° C. or less, and more preferably contains indium or tin. Among these, indium has a low melting point and therefore tends to easily form a sea-island structure. In addition, a metal layer made of indium is also preferable in that it has excellent metallic luster and good weather resistance.

[0040] The reason why a metal layer containing indium or tin is likely to form a sea-island structure is presumed to be as follows. When a metal with a relatively low melting point is used to form a film by vapor deposition, it takes a relatively long time for the metal that has reached the substrate surface to solidify. The higher the substrate temperature during vapor deposition, the longer the time until solidification. For this reason, it is considered that the metal before solidification moves on the substrate surface, collides with other metals, and combines to form islands. It is considered that the islands then grow by absorbing metal that has reached the substrate surface while repeating collisions and combinations, thereby forming a sea-island structure. In particular, indium and tin have extremely low melting points of 156°C and 232°C, respectively. For this reason, it is considered that the solidification rate on the substrate surface is slow and the above-mentioned collisions and combinations occur frequently, making it easier to form a sea-island structure.

[0041] xy can be adjusted by changing the wettability between the metal layer and the surface on which the metal layer is formed, as well as the deposition time of the metal layer and the substrate temperature during deposition. The effects of the wettability with the base and the deposition time on the cross-sectional shape of the island portion are presumed to be as follows. If the wettability between the metal layer and the base surface is too high, the metal solidifies as islands with a small contact angle with the base layer in the early stages of deposition, i.e. islands with a large xy. As the deposition time increases and the film thickness increases, the islands grow so that the length y increases relatively more than the length x, but it is thought that the shape of the islands in the early stages has an influence and the difference in length xy is unlikely to become small. For this reason, it is thought that if the wettability is too high, it tends to be difficult for the islands of the metal layer to satisfy formula (1). On the other hand, when the wettability with the metal layer is relatively low, the metal solidifies as an island with a large contact angle with the underlayer in the initial stage of deposition. In other words, it is thought that since an island with a nearly rectangular shape is likely to be formed in the initial stage of deposition, the length difference xy is likely to be relatively small. For this reason, when the wettability with the metal layer is relatively low, there is a tendency to easily obtain an island that satisfies formula (1). Even if the length difference xy does not satisfy formula (1) in the initial stage of deposition, if an island with a relatively small length is formed, by extending the deposition time, the island will grow so that the length y increases relatively more than the length x, and the length difference xy will become relatively small, and formula (1) may be satisfied.

[0042] In the present invention, the surface free energy of the substrate layer and the primer layer on which the metal layer is to be formed is 40 mJ / m 2 More preferably, 41 mJ / m 2 More preferably, it is 56 mJ / m or more. 2 It is preferable that the concentration is less than 55 mJ / m 2 In particular, when the metal layer contains indium or tin, the surface free energy is 42 mJ / m or less. 2 More preferably, 44 mJ / m 2 More preferably, it is 54 mJ / m or more. 2 It is preferable that the concentration is less than 52 mJ / m 2 By setting the surface free energy of the surfaces of the base layer and the primer layer on which the metal layer is formed to fall within the above range, the wettability with the metal layer is appropriately adjusted, and the difference in length (xy) of the island portions tends to satisfy formula (1).

[0043] Methods for forming the metal layer include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma CVD using plasma and catalytic chemical vapor deposition (Cat-CVD) in which a material gas is catalytically decomposed using a heated catalyst. Among these, vacuum deposition is preferred because it can be used with any material. That is, physical vapor deposition films are preferred as metal layers, and vacuum deposition films are more preferred.

[0044] From the viewpoints of metallic luster and moldability, each island portion is preferably formed to have a thickness of 30 to 100 nm, and more preferably 40 to 80 nm. The thickness of each island can be adjusted, for example, by the deposition time, that is, by increasing the deposition time, the thickness of each island can be increased.

[0045] In the metal layer of the present invention, the area ratio of the sea part in plan view is preferably 10% or more and 25% or less. The larger the area ratio of the sea part, the larger the interval between adjacent island parts. By setting the area ratio of the sea part to be 10% or more and 25% or less, it is possible to improve the electromagnetic wave transmittance and to easily obtain a metallic decorative sheet with a high reflectance (60% or more).

[0046] In addition, when a metallic decorative sheet is bonded by injection molding or a decorative molding sheet is attached to a molding to produce a metallic decorative molding, deformation due to the sheet conforming to a three-dimensional curved surface and shrinkage due to heat occur. At this time, the island parts may come into contact with each other during molding of the metallic decorative molding, causing the metallic decorative sheet to whiten. From the viewpoint of suppressing whitening, the area ratio of the sea part is preferably 10% or more, and more preferably 12% or more. On the other hand, if the area ratio of the sea part is too large, it becomes difficult to make the reflectance of the metallic decorative sheet 60% (it becomes difficult to obtain a metallic luster). From this viewpoint, the area ratio of the sea part is preferably 25% or less, and more preferably 23% or less.

[0047] In the present invention, the area ratio (%) of the sea portion can be determined by the following method. First, the surface of the metal layer is observed with an electron microscope under the following conditions to obtain an image. Equipment: Scanning electron microscope Observation conditions Acceleration voltage: 5 kV Emission current: 10μA Pixel size: 9.5~10.0nm Working distance: 15mm Magnification: 10,000x Gradation: 8-bit

[0048] From the image obtained under the above conditions, 800,000 to 900,000 pixels were cut out. The cut-out image was binarized based on Otsu's method. The ratio of the sea area to the entire cut-out image was taken as the sea area ratio (%) of that part. This process was performed on 20 parts of the image, and the average value of the 20 parts was taken as the sea area ratio (%) of the metal layer.

[0049] In the metal layer of the present invention, assuming that each island is circular and the average diameter calculated from the area of ​​each island is defined as the "island size," the island size is preferably 100 nm to 300 nm. The "island size" defined in this way corresponds to the length x of the side of the island on the substrate layer side when viewed in cross section. When the size of the island portion as defined above is 100 nm, the island portion is more likely to satisfy formula (1). In addition, it is easier to obtain a high reflectance (60% or more). As a result, a metallic decorative sheet with excellent metallic luster can be obtained. Furthermore, by setting the size of the island portion to 125 nm or more, more preferably 160 nm or more, it is easier to obtain a metallic decorative sheet in which a metal layer with a higher reflectance is formed. On the other hand, if the size of the island portion is too large, the electromagnetic wave transmittance at radar wavelengths is likely to decrease. From this viewpoint, the size of the island portion is preferably 300 nm or less, and more preferably 275 nm or less.

[0050] The area of ​​each island can be calculated using the following method. First, an electron microscope image of the metal layer surface is obtained under the same conditions as those for calculating the area ratio of the sea portion, and the image is subjected to binarization processing.

[0051] Next, a square frame that can hold 50 to 100 islands is placed on the photograph. The length of one side of the frame is L [nm]. "L" represents the actual size on the sample, and can be calculated, for example, based on the pixel size or scale bar of the SEM photograph. Next, count the number of islands (n1) that are entirely contained within the frame, the number of islands (n2) that are recognized as existing within the frame with 1 / 2 or more and less than 1 of the island's area, and the number of islands (n3) that are recognized as existing within the frame with less than 1 / 2 of the island's area. Based on the counted n1, n2, and n3, "n" shown in the following formula (i) is assumed to be the number of islands existing within the frame. n = n1 + (3n2 + n3) / 4 (i) Next, the total area of ​​the islands in the frame is calculated, and the total area is expressed as "S [nm 2 ]". And, S[nm 2 ] and the number (n) of islands in the frame calculated by formula (i), “a” in the following formula (ii) is calculated as the area [nm 2 ] is assumed. a = S / n (ii)

[0052] As shown in the electron microscope photograph of Figure 2, the islands have an indefinite shape. For this reason, in this specification, when calculating the island size, each island is assumed to be circular. The diameter of an island assumed to be circular is defined as the "island size." In this specification, the area a [nm 2 The island size d [nm] is calculated from the above equation (iii). The average value of "d" at 20 locations is defined as the island size D [nm] in this specification. d=(4a / π) 1 / 2 (iii)

[0053] The area ratio of the sea parts and the size of the island parts can be adjusted by the deposition time, the substrate temperature during deposition, the material of the substrate layer, the material of the primer layer described below, etc. Specifically, by extending the deposition time, the size of the island parts can be increased while the area ratio of the sea parts can be reduced.

[0054] <Adhesive layer> The metallic decorative sheet of the present invention may have an adhesive layer to adhere the substrate layer on which the metal layer is formed to the adherend. In this case, the adhesive layer is provided on the surface of the metal layer opposite the substrate. The adhesive layer is formed so that the resin for the adhesive layer penetrates between adjacent island portions (sea portion). The substrate layer or primer layer that penetrates the sea portion comes into contact with the resin for the adhesive layer and adheres well, thereby improving chipping resistance.

[0055] The adhesive layer is preferably made of a heat-sensitive or pressure-sensitive resin, in other words, the adhesive layer is preferably a so-called heat-sensitive adhesive layer or pressure-sensitive adhesive layer.

[0056] The resin used in the adhesive layer is preferably a general-purpose acrylic resin, urethane resin, polyester resin, silicone resin, vinyl chloride resin, vinyl acetate resin, or a mixture or copolymer of two or more of these. From the viewpoint of adhesive strength, acrylic resin is more preferable. In the case of a heat-sensitive adhesive layer, the thickness is preferably 0.5 to 3 μm, and more preferably 0.5 to 1.5 μm, and in the case of a pressure-sensitive adhesive, the thickness is preferably 20 to 100 μm, and more preferably 30 to 60 μm.

[0057] The glass transition temperature Tg of the adhesive layer is preferably from 0 to 30°C, more preferably from 5 to 28°C, and further preferably from 10 to 26°C. By setting the glass transition temperature to 0°C or higher, it is easy to improve resistance to chipping (chipping resistance), and also to improve heat resistance, which makes it easy to prevent the surface smoothness of the decorative molding from decreasing. Furthermore, by setting the glass transition temperature to 30°C or lower, it is easy to prevent the chipping resistance from decreasing due to a decrease in adhesion. Furthermore, when the glass transition temperature is 0 to 30°C, it is easy to balance the chipping resistance of the decorative molding and the surface smoothness of the metallic decorative sheet at high temperatures.

[0058] <Release layer> The metallic decorative sheet may have a release layer on the surface of the adhesive layer opposite the substrate for the purpose of protecting the adhesive layer. The release layer is easily peelable from the adhesive layer when the decorated molded product is produced by a vacuum molding method. The release layer preferably contains a release agent to improve the releasability. For example, the release layer may be a layer containing a release agent and a binder resin. As the release agent, a melamine resin-based release agent, a silicone-based release agent, a fluororesin-based release agent, a cellulose resin-based release agent, a urea resin-based release agent, a polyolefin resin-based release agent, a paraffin-based release agent, an acrylic resin-based release agent, and a composite release agent thereof are preferable. Among these, a silicone-based release agent is particularly preferable. As the binder resin, a thermoplastic resin is preferably used, and examples thereof include an acrylic resin, a polyester resin, a cellulose derivative resin, a polyvinyl acetal resin, a polyvinyl butyral resin, a vinyl chloride-vinyl acetate copolymer, and a chlorinated polyolefin resin. The release layer can be formed by applying and drying an ink prepared by dissolving or dispersing the above-mentioned release agent and binder resin together with necessary additives in an appropriate solvent using a known method such as gravure coating, roll coating, comma coating, gravure printing, screen printing, or gravure reverse roll coating.

[0059] Alternatively, the release layer may be a release film having a release layer containing the above-mentioned release agent provided on one side of a known resin film such as a polyester film.

[0060] <Backer layer> The metallic decorative sheet may have a backer layer on the inner layer side of the metal layer (the side opposite the base layer across the metal layer). The backer layer has the role of improving the strength of the metallic decorative sheet and maintaining the shape of the metallic decorative molding formed from the metallic decorative sheet.

[0061] The thickness of the backing layer is not particularly limited and may be appropriately selected within the range of, for example, 0.1 to 10 mm. A plurality of backing layers may be laminated on the inner layer side of the metal layer.

[0062] The backer layer may be transparent, but is preferably achromatic (gray, black) other than white, more preferably black, in order to suppress surface reflection of the backer layer. The backer layer preferably contains a pigment to make it achromatic. The pigment in the backer layer may be a black pigment alone or a mixture of a black pigment and another pigment (such as a white pigment).

[0063] Examples of the binder resin of the backer layer include polyolefin resins such as polyethylene, polypropylene, polybutene, polymethylpentene, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, and olefin-based thermoplastic elastomer, ABS (acrylonitrile-butadiene-styrene copolymer) resin, styrene resin, vinyl chloride resin, acrylic resin, and polycarbonate resin. Among these binder resins, it is preferable to contain ABS resin from the viewpoint of suppressing cracks during molding. The proportion of ABS resin to the total binder resin of the backer layer is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0064] If necessary, any additives such as light stabilizers such as ultraviolet absorbers, plasticizers, fillers, antioxidants, lubricants, and antistatic agents may be added to the backing layer.

[0065] The backer layer preferably has a thermal shrinkage rate of 1.0% or less, more preferably 0.5% or less, and even more preferably 0.1% or less, when heated for 30 minutes at 75° C. By reducing the thermal shrinkage rate of the backer layer, it is possible to easily suppress the deterioration of metallic luster caused by the backer layer.

[0066] <Other layers> The metallic decorative sheet may have layers other than those exemplified above, as long as they do not significantly affect the reflectance.

[0067] [Metallic decorative molding] The metallic decorative molded article of the present invention is formed by integrating an adherend with the metallic decorative sheet of the present invention. When the metallic decorative sheet has an adhesive layer, the adhesive layer is located on the adherend side.

[0068] <Adherend> The adherend used for the metallic decorated molded article of the metallic decorated sheet of the present invention is not particularly limited, and examples thereof include molded articles made of glass, ceramics, resin, and the like. The adherend may be one that has been molded in advance into the shape of the molded article, or may be formed into the shape of the molded article during decorative molding by vacuum molding, insert molding, or the like. The thickness of the adherend is not particularly limited, but is usually 1 mm or more, and preferably 1 to 10 mm.

[0069] [Method of manufacturing metallic decorative moldings] For example, a metallic decorated molded article can be produced by vacuum forming including the following steps (y1) to (y2). (y1) A laminate is prepared by attaching the adhesive layer side of the metallic decorative sheet to an adherend. (y2) The laminate is placed with the adherend side facing the mold and vacuum molded. EXAMPLES

[0070] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples in any way.

[0071] 1. Measurement and Evaluation The metallic decorative sheets and metallic molded articles obtained in the examples and comparative examples were subjected to the following measurements and evaluations. The results are shown in Table 1.

[0072] 1-1. Electron microscope observation of the cross section of an indium evaporated film Observation sheets were cut out from the metallic decorative sheets of the examples and comparative examples, embedded in a thermosetting resin consisting of a mixture of epoxyphenol novolac and imidazole, and the resin was cured to prepare observation samples. The observation samples were cut in the lamination direction of the metallic decorative sheets. The cross sections of the observation samples were observed with an electron microscope under the following conditions to obtain cross-sectional images. Equipment: Scanning electron microscope (Hitachi High-Technologies Corporation, S-4800) Observation conditions Acceleration voltage: 3 kV Emission current: 10μA Pixel size: 0.9~1.0nm Working distance: 3.5mm Magnification: 50,000x

[0073] 1-2. Measuring the length of the island From the electron microscope cross-sectional image obtained in 1-1 above, the length x of the side on the base material layer side of each island and the length y of the side opposite the base material layer were measured according to the definitions explained above. The length difference xy was calculated from the obtained lengths x and y. x, y, and xy were obtained for each of the 10 island points in the image. The average length difference xy is shown in Table 1.

[0074] 1-3. Electron microscope observation of the surface of an indium evaporated film A sheet piece for observation was cut out separately from each of the metallic decorative sheets of the examples and the comparative examples, and the surface of the indium vapor deposition film was observed with an electron microscope to obtain an image. The observation conditions are described below. Equipment: Scanning electron microscope (Hitachi High-Technologies Corporation, SU8040) Observation conditions Acceleration voltage: 5 kV Emission current: 10μA Pixel size: 9.5~10.0nm Working distance: 15mm Magnification: 10,000x Gradation: 8-bit

[0075] 1-4. Calculation of sea area ratio 800,000 pixels were cut out from the electron microscope images of the metallic decorative sheets of the examples and comparative examples obtained under the conditions described in 1-3 above. The cut-out images were binarized based on Otsu's method, and the area ratio (%) of the sea area was calculated for each image. The results are shown in Table 1.

[0076] 1-5.Reflectance measurement Samples were cut out from the metallic decorative sheets of the examples and comparative examples, and a spectrophotometer (manufactured by JASCO Corporation, product name: V-670) was used to direct measurement light at an incident angle of 5 degrees onto the sample from the base layer (PMMA) side, and the reflectance of the sample at a wavelength of 550 nm was measured. The reflectance (wavelength 550 nm) of samples cut out from 10 locations on each sheet was measured, and the average value was taken as the reflectance (%) of the metallic decorative sheet. The results are shown in Table 1.

[0077] 1-6. Chipping resistance The chipping resistance test was performed by a Gravello test in accordance with the standard number SAE J-400, standard name Test for Chip Resistance of Surface Coatings. FIG. 5 is a schematic diagram of a Gravello test device for evaluating the chipping resistance of the metallic decorative molded body obtained in the examples and comparative examples. Using the Gravello test device 200, the metallic decorative molded body 100 obtained in the examples and comparative examples on a test support 220 (material: ceramic) was irradiated with No. 7 crushed stone 210 (100 g) at -20°C from a position perpendicular to the metallic decorative molded body 100 at a distance of 350 mm at an injection pressure of 0.4 MPa for 1 second, and the peeling condition of the film of the metallic decorative molded body 100 was confirmed. The evaluation criteria are as follows. <Evaluation criteria> A: Visual inspection revealed no peeling of the film. B: Visual observation revealed almost no peeling of the film. C: Visual inspection revealed peeling of the film. 1-7. Surface free energy measurement The contact angle of the primer layer surface obtained in the examples and comparative examples was measured by the sessile drop method using a contact angle meter Drop Master 500 (manufactured by Kyowa Interface Science Co., Ltd.). Water and diiodomethane (2 μL each) were used as test liquids. The test environment was 23° C. and relative humidity 50%. The surface free energy was calculated using the following formulas (A) and (B) obtained by combining Owens' equation and Young's equation. (1+cosθ)×(γ L / 2)=(γ S d ×γ L d ) 1 / 2 +(γ S p ×γ L p ) 1 / 2 …(A) Gamma S =γ S d +γ S p …(B) θ: contact angle Gamma S: Surface free energy of the measurement surface Gamma L : Surface free energy of the test liquid Gamma S d : Dispersion component of surface free energy of the measurement surface Gamma L d : Dispersion component of surface free energy of test liquid Gamma S p : Polar component of surface free energy of the measurement surface Gamma L p : Polar component of surface free energy of test liquid γ of water and diiodomethane L , γ L d , γ L p The values ​​are as follows: <Water> Gamma L =72.8mJ / m 2 , γ L d =21.8mJ / m 2 , γ L p =51.0mJ / m 2 <Diiodomethane> Gamma L =50.8mJ / m 2 , γ L d =48.3mJ / m 2 , γ L p =2.5mJ / m 2 The contact angles θ and γ obtained by the above measurement for water and diiodomethane, respectively L , γ L d , γ L p The surface free energy of the primer layer (measurement surface) was calculated by introducing the values ​​of into the formulas (A) and (B) and solving the simultaneous equations. The calculation was performed using the software (FAMAS) attached to the contact angle meter. The results are shown in Table 1.

[0078] 2. Manufacturing metallic decorative sheets [Example 1] A primer layer-forming coating solution 1 having the following formulation was prepared. The primer layer forming coating solution 1 was applied onto a substrate layer of PMMA (manufactured by S-Carbo Sheet Co., Ltd., product name "Technoloy Film S001G", width 1 m, thickness 125 μm) and dried to form a primer layer with a thickness of 2 μm. An indium vapor deposition film was formed on the primer layer formed under the vapor deposition conditions shown in Table 1 to obtain a metallic decorative sheet of Example 1. The vapor deposition was performed using a vapor deposition device of the resistance heating vapor deposition type (manufactured by ULVAC, Inc., EX-200). The pressure inside the chamber at the start of vapor deposition was 1.0×10 -3 It was Pa. <Primer layer forming coating liquid 1> Acrylic polyol (manufactured by Arakawa Chemical Industries, product name Aracoat DA105) 100 parts by weight Isocyanate compound (Arakawa Chemical Industries, product name Aracoat CL102H) 9 parts by weight Solvent (manufactured by Showa Ink Industries Co., Ltd., product name: Chemical X-NT Solvent) appropriate amount

[0079] [Example 2] A primer layer-forming coating solution 2 having the following formulation was prepared. The primer layer-forming coating solution 2 was applied to the same substrate layer as in Example 1, and dried to form a primer layer having a thickness of 2 μm. An indium vapor deposition film was formed on the primer layer under the vapor deposition conditions shown in Table 1 to obtain a metallic decorative sheet of Example 2. <Primer layer forming coating liquid 2> Polyester resin (Showa Ink Industrial Co., Ltd., product name SIVM HS) 100 parts by weight Isocyanate compound (manufactured by Showa Ink Industries Co., Ltd., product name OP No. 81) 5.0 parts by mass Solvent (manufactured by Showa Ink Industries Co., Ltd., product name: Chemical X-NT Solvent) appropriate amount

[0080] [Example 3] A primer layer-forming coating solution 3 having the following formulation was prepared. The primer layer-forming coating solution 3 was applied to the same substrate layer as in Example 1, and dried to form a primer layer having a thickness of 2 μm. An indium vapor deposition film was formed on the primer layer under the vapor deposition conditions shown in Table 1 to obtain a metallic decorative sheet of Example 3. <Primer layer forming coating liquid 3> Acrylic resin and vinyl chloride-vinyl acetate copolymer resin (Showa Ink Industrial Co., Ltd., "KAX(NT) Medium") Solvent (manufactured by Showa Ink Industries Co., Ltd., product name: Chemical X-NT Solvent) appropriate amount

[0081] [Example 4] A primer layer-forming coating solution 4 having the following formulation was prepared. The primer layer-forming coating liquid 4 was applied onto the same substrate layer as in Example 1 and dried to form a primer layer having a thickness of 2 μm. Next, the surface of the primer layer was subjected to a corona treatment using a corona treatment device equipped with a feeding / winding device under the conditions of an output of 100 W, a substrate-electrode distance of 1.5 mm, and a substrate conveying speed of 20 m / min. Next, an indium vapor deposition film was formed on the primer layer that had been subjected to the corona treatment under the vapor deposition conditions shown in Table 1, thereby obtaining a metallic decorative sheet of Example 4. <Primer layer forming coating liquid 4> Vinyl fluorine resin 100 parts by weight Isocyanate compound (Arakawa Chemical Industries, product name Aracoat CL102H) 5.0 parts by mass Solvent (manufactured by Showa Ink Industries Co., Ltd., product name: Chemical X-NT Solvent) appropriate amount

[0082] [Comparative Example 1] The primer layer-forming coating solution 1 was applied to the same substrate layer as in Example 1, and dried to form a primer layer having a thickness of 2 μm. An indium vapor deposition film was formed on the primer layer thus formed under the vapor deposition conditions shown in Table 1, to obtain a metallic decorative sheet of Comparative Example 1.

[0083] [Comparative Example 2] Except for the fact that the surface of the primer layer was subjected to a corona treatment before forming an indium vapor deposition film, a metallic decorative sheet of Comparative Example 2 was obtained by the same process as in Example 2. The corona treatment was performed using a corona treatment device equipped with a feeding / winding device under the conditions of an output of 100 W, a substrate-electrode distance of 1.5 mm, and a substrate conveying speed of 20 m / min.

[0084] 3. Preparation of metallic decorative moldings 100 parts by mass of an acrylic pressure-sensitive adhesive (manufactured by Soken Chemical Industries, Ltd., product name: SK Dyne 2094, solid content 25% by mass) was mixed with 0.27 parts by mass of an epoxy crosslinking agent (manufactured by Soken Chemical Industries, Ltd., product name: E-AX, solid content 5% by mass) to obtain a composition for adhesive layer. The composition for adhesive layer was applied to the release-treated surface of a 38 μm-thick polyester film (manufactured by Toyobo Co., Ltd., product name: E7304, width 1 m) that had been silicone-treated for release, so that the thickness after drying was 40 μm, and then dried to form a pressure-sensitive adhesive sheet (a sheet with a pressure-sensitive adhesive layer formed thereon).

[0085] A pressure-sensitive adhesive sheet was placed on the metal layer of each of the metallic decorative sheets of the Examples and Comparative Examples with the adhesive layer facing the metal layer, and the sheets were bonded under conditions of a nip pressure of 0.4 MPa and a line speed of 1.0 m / min.

[0086] Next, for each of the Examples and Comparative Examples, the polyester film was peeled off and attached to a 3 mm thick transparent ABS plate via the adhesive layer side. A mold of the desired shape was prepared, and the ABS side was placed facing the mold and vacuum molded (ABS plate reached temperature 160°C) to obtain the metallic decorative molded bodies of the Examples and Comparative Examples.

[0087] 4.Results [Table 1]

[0088] In Examples 1 to 4, an indium vapor deposition film was formed in which the difference in length xy was 0 nm to 80 nm, resulting in a metallic decorative sheet with high reflectance. In particular, Examples 1 to 3 had good chipping resistance. This is believed to be because the adhesive layer composition was sufficiently permeated between the island parts (sea part), ensuring good adhesion between the metal layer and the adhesive layer, and between the primer layer and the adhesive layer. On the other hand, in Comparative Example 1 and Comparative Example 2, the length difference xy was large at 85 nm and 90 nm, respectively, and the cross-sectional shape of the island was trapezoidal, resulting in a metallic decorative sheet with low reflectance. In Comparative Example 1 and Comparative Example 2, the length difference xy was large, which resulted in a gentle slope of the side surface of the island, making it easy for the adhesive layer composition to penetrate between the island portions, and ensuring good adhesion between the adhesive layer and the primer layer, resulting in good chipping resistance.

[0089] A cross-sectional electron microscope image of the metallic decorative sheet of Example 1 is shown in Fig. 1. A cross-sectional electron microscope image of the metallic decorative sheet of Comparative Example 1 is shown in Fig. 6. Comparing Fig. 1 and Fig. 6, it can be seen that the indium vapor deposition film of Example 1 has a cross-sectional shape closer to a rectangle. Comparative Example 1 and Example 1 are experimental examples in which a metal layer was formed on the same primer layer with different deposition times. Example 1 has a smaller difference in length xy and a lower area ratio of the sea portion compared to Comparative Example 1. From this, it is considered that as the film thickness increases, the island portions grow such that the increase in length y is greater than the increase in length x.

[0090] Comparing Examples 1 to 4 with Comparative Example 2, it can be seen that the surface free energy is lower in the Examples, and the length difference xy is smaller. Also, among the Examples, there is a tendency that the lower the surface free energy, the smaller the length difference xy. Generally, the wettability with the metal layer tends to increase by performing a corona treatment. Example 4 is an example in which the wettability with the metal layer is improved by performing a corona treatment on the surface of the primer layer, and an island portion in which the length difference xy satisfies formula (1) is formed. On the other hand, in Comparative Example 2, the surface free energy becomes too large compared to Example 2 due to the corona treatment, and the wettability with the metal layer becomes too high, so that the length difference xy does not satisfy formula (1).

[0091] [Example 5] For the thin-line model shown in Figure 7, the reflectance (%) of the metallic decorative sheet at a wavelength of 550 nm was calculated by simulation based on the Rigorous Coupled Wave Analysis (RCWA) method when the size of the island (length x, y) and the area ratio of the sea were changed.

[0092] In the simulation, the sea-island structure was simplified to one dimension. In the above simulation, the layer structure of the metallic decorative sheet was a substrate layer (PMMA) / metal layer (indium vapor deposition film). Figure 7 shows the length x of the side of the island on the substrate layer side, and the length y of the side opposite the substrate layer. The light-emitting surface was placed on the substrate layer side, and it was set that light was incident on the substrate layer at an incident angle of 5°.

[0093] In the model in Fig. 7, the length x of the side of the island on the substrate layer side corresponds to the size of the island. In Fig. 7, the cross section of the island is shown as a trapezoid, but the difference in length xy being 0 means that the cross section of the island is rectangular.

[0094] The parameters used in the calculation are shown below. Optical constants of the base layer: n=1.49, k=0 Base layer thickness: 1.0 μm Optical constants of metal layer: n=1.0556, k=4.9524 Metal layer thickness: 50nm Island size: 100nm~300nm xy values: 0nm~100nm Sea area ratio: 10-25%

[0095] Tables 2 to 5 show the simulation results of the reflectance when the length x and the length difference xy are changed for the area ratios of the sea portion of 10%, 15%, 20%, and 25%, respectively.

[0096] [Table 2]

[0097] [Table 3]

[0098] [Table 4]

[0099] [Table 5]

[0100] As is clear from Tables 2 to 5, regardless of the area ratio of the sea portion, for the same island size (length x), the smaller the difference in length xy, the more likely it is that a high reflectance of 60% or more can be obtained. Also, the larger the island size, the higher the reflectance tends to be. From the results of Tables 2 to 5, it is clear that a desired reflectance can be obtained by changing the length difference xy at any area ratio of the sea portion. In particular, by setting the length difference xy within the range of 0 nm to 80 nm, a metallic decorative sheet with high reflectance can be obtained. In addition, it is clear that a high reflectance can be obtained by making the length difference xy smaller even when the area ratio of the sea portion is relatively large.

[0101] 100 Molded body 200 Clavero Test Equipment 210 Crushed Stone 220 Test Support

Claims

1. A metallic decorative sheet having a metal layer on a base layer, the metal layer has a plurality of island portions containing a metal and a sea portion located between the island portions, The metal layer contains a metal having a melting point of 240° C. or less, The island portion has a convex quadrangle when viewed in cross section, and one side of the quadrangle faces the base layer, The metallic decorative sheet, wherein 0≦x−y≦80, is satisfied when the length of the side of the island portion on the base layer side is x [nm] and the length of the side of the island portion on the opposite side to the base layer is y [nm].

2. The metallic decorative sheet according to claim 1 , which has a reflectance of 60% or more at a wavelength of 550 nm.

3. Further comprising an adhesive layer on the metal layer side opposite the base layer, A part of the adhesive layer is filled in the sea portion, The metallic decorative sheet according to claim 1 or 2, wherein the x [nm] and the y [nm] satisfy 0 < x - y ≦ 80 nm.

4. The metallic decorative sheet according to claim 3, wherein the x [nm] and the y [nm] satisfy 10≦x−y≦80 nm.

5. The metallic decorative sheet according to any one of claims 1 to 4, wherein an area ratio of a sea portion when the metal layer is viewed in a plane is 10% or more and 25% or less.

6. The metallic decorative sheet according to any one of claims 1 to 5, wherein, assuming that each of the island portions is circular, and the average diameter calculated from the area of ​​each of the island portions is defined as the size of the island portions, the size is 100 nm or more and 300 nm or less.

7. The metallic decorative sheet according to any one of claims 1 to 6, wherein the metal layer contains indium or tin.

8. A metallic decorative molding comprising the metallic decorative sheet according to any one of claims 1 to 7 and an adherend.

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