JP2021104616A - Metal decorative sheet, and metal decorative molding and display device using the same, and manufacturing method of metal decorative sheet - Google Patents

Abstract

To provide a metal decorative sheet having light transmittance while suppressing chipping.SOLUTION: A metal decorative sheet having a base layer, a metal layer and an adhesive layer in this order, in which the metal layer has a plurality of islands including a metal and a sea portion located between the islands, in which the sea portion has a filling portion in which the adhesive layer is filled in the thickness direction and an unfilled portion in which the adhesive layer is not filled, a ratio of the thickness of the filling portion to the thickness per one of the sea portions is 10% or larger and smaller than 100%.SELECTED DRAWING: Figure 1

Description

The present invention relates to a metal-like decorative sheet, a metal-like decorative molded body and a display device using the same, and a method for manufacturing the metal-like decorative sheet.

Conventionally, a metal-like decorative sheet and a metal-like decorative molded body using the metal-like decorative sheet are known. Further, by arranging the light source on the back side of the metal-like decorative sheet and the metal-like decorative molded body, the metal-like decorative sheet and the metal-like decorative molded body have a metallic-like design when the light source is turned off. It has also been proposed that when the light source is turned on, the transmitted light from the light source causes the design to be different from that when the light source is turned off.
For example, in Patent Document 1, by using a metal thin film layer, a decorative sheet and decorative resin molding that produce a metallic design when the light source is turned off and an excellent design by the transmitted light from the light source when the light source is turned on. The product is disclosed.

Further, in order to enhance the design of an adherend such as a resin molded body by using a decorative sheet having a metallic luster, a means for imparting a metallic luster to the surface of the adherend has been proposed. In particular, a vacuum forming method or an injection molding method has been used for decorating an adherend having a complicated surface shape such as a three-dimensional curved surface.
For example, in the case of the vacuum forming method, the decorative film is adhered by stretching the decorative film while heating and softening it, depressurizing the space on the adherend side of the decorative film, and pressurizing the space on the opposite side as necessary. While forming along the three-dimensional three-dimensional shape of the surface of the body, they are bonded together using an adhesive or the like.

Japanese Unexamined Patent Publication No. 2017-189983

When the metallic decorative molded body is provided with a light source on the back surface, the expression of an excellent design by the transmitted light when the light source is lit can be realized by setting the visible light transmittance high. However, since it is necessary to set a high visible light reflectance in order to exhibit a high-quality metallic luster when the light source is turned off, it is usually designed to lower the visible light transmittance by that amount. Against this background, there is a demand for the design of a metallic decorative sheet that has sufficient light transmission and can exhibit a high-quality metallic luster when the light source is turned off.

Further, when a metal-like decorative molded body in which a metal-like decorative sheet and an adherend are attached with an adhesive layer is used for the exterior of a vehicle body such as an automobile, the adhesion strength with the adherend is not sufficient. Therefore, it has been found that there is a problem that the surface layer is peeled off (also referred to as chipping) due to flying stones or the like while the vehicle body is traveling.

As a result of diligent studies, the present inventors have used a metal-like decorative sheet having sufficient light transmission while suppressing chipping by combining the metal layer and the adhesive layer in a specific configuration, and the metal-like decorative sheet. We have found that it can be used as a metal-like decorative molded body and a display device, and have completed the present invention.

The present invention provides the following [1] to [8].
[1] A metal-like decorative sheet having a base material layer, a metal layer, and an adhesive layer in this order, and the metal layer has a plurality of islands containing metal and a sea portion located between the islands. The sea portion has a filled portion filled with the adhesive layer and a non-filled portion not filled with the adhesive layer in the thickness direction, and the ratio of the thickness of the filled portion to the thickness per sea portion. Is a metal-like decorative sheet that is 10% or more and less than 100%.
[2] The metal-like decorative sheet according to [1], wherein the ratio of the thickness of the filling portion to the thickness of one sea portion is 10% or more and 80% or less.
[3] The metallic decorative sheet according to [1] or [2], wherein the thickness per island is 30 to 100 nm.
[4] The metal-like decorative sheet according to any one of [1] to [3], wherein the metal layer contains indium or tin.
[5] The metal-like decorative sheet according to any one of [1] to [4], which has a release layer on the side of the adhesive layer opposite to the metal layer.
[6] A metal-like decorative molded body having the metal-like decorative sheet according to any one of [1] to [5] and an adherend.
[7] A display device having the metal-like decorative molded article according to [6] on the front surface of a light source.
[8] Adhesion on the release layer to the surface of the metal-like sheet having a metal layer having a plurality of islands containing metal and a sea portion located between the islands on the base material layer on the metal layer side. It has a laminating process of laminating the adhesive surfaces of the adhesive sheet with layers,
In the thickness direction of the sea portion, there is a filled portion in which the adhesive layer is filled and a non-filled portion in which the adhesive layer is not filled, and the ratio of the thickness of the filled portion to the thickness per sea portion is 10%. As described above, a method for manufacturing a metallic decorative sheet, wherein the laminating step is performed so as to be less than 100%.

According to the present invention, a metal-like decorative sheet having sufficient light transmission while suppressing chipping, a metal-like decorative molded body and display device using the same, and a method for manufacturing the metal-like decorative sheet are provided. Can be provided.

It is sectional drawing which shows one Embodiment of the metal-like decorative sheet of this invention. It is an SEM photograph of the metal layer in one Embodiment of the metal-like decorative sheet of this invention. It is a top view which showed the dimension by enlarging the metal-like decorative sheet shown in FIG. It is sectional drawing which shows one Embodiment of the metal-like decorative molded article of this invention. It is sectional drawing which shows one Embodiment of the display device of this invention. It is a schematic diagram of the Grabello test apparatus for evaluating the chipping resistance.

Hereinafter, embodiments of the present invention will be described. In addition, in this specification, AA to BB mean that it is AA or more and BB or less.

[Metallic decoration sheet]
The metallic decorative sheet of the present invention has a base material layer, a metal layer, and an adhesive layer in this order, and the metal layer includes a plurality of islands containing metal and a sea portion located between the islands. The sea portion has a filled portion filled with the adhesive layer and a non-filled portion not filled with the adhesive layer in the thickness direction, and the thickness of the filled portion relative to the thickness per sea portion. The ratio of is 10% or more and less than 100%.

FIG. 1 is a cross-sectional view showing an embodiment of the metallic decorative sheet of the present invention.
The metal-like decorative sheet 100 of FIG. 1 has a base material layer 110, a metal layer 120, and an adhesive layer 130 in this order. Further, the metal layer 120 of the metal-like decorative sheet of FIG. 1 has a sea-island structure having a plurality of island portions 121 containing metal and a sea portion 122 located between the island portions 121. The sea portion 122 has a filled portion 122a in which the adhesive layer is filled and a non-filled portion 122b in which the adhesive layer is not filled in the thickness direction, and the ratio of the thickness of the filled portion to the thickness per sea portion is 10% or more. , Less than 100%.

The metal-like decorative sheet of the present invention may have a base material layer 110, a metal layer 120, and an adhesive layer 130 in this order, and a primer layer 140, a release layer, etc., which will be described later, may be provided between or on the surface of these layers. It may have other layers.

<Example of layer structure of metallic decorative sheet>
Specific examples of the metallic decorative sheet include the following configurations (1) to (8). In addition, "/" means the boundary of each layer.
(1) Base material layer / Metal layer / Adhesive layer (2) Base material layer / Metal layer / Adhesive layer / Peeling layer (3) Base material layer / Primer layer / Metal layer / Adhesive layer (4) Base material layer / Primer Layer / Metal layer / Adhesive layer / Peeling layer (5) Base material layer / Metal layer / Adhesive layer / Backer layer (6) Base material layer / Primer layer / Metal layer / Adhesive layer / Backer layer (7) Base material layer / Metal layer / adhesive layer / backer layer / second adhesive layer (8) Base material layer / primer layer / metal layer / adhesive layer / backer layer / second adhesive layer

<Base layer>
In the decorative sheet of the present invention, the base material layer preferably has a role as a support for the metallic decorative sheet. Further, the base material layer is preferably arranged on the outermost layer side, and in that case, it has a role of imparting scratch resistance to the metal-like decorative sheet. As the base material layer, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, vinyl resins such as ethylene-vinyl alcohol copolymer, polyethylene terephthalate, and the like. Represented by polyester resins such as polyethylene naphthalate and polybutylene terephthalate, acrylic resins such as methyl poly (meth) acrylate and ethyl poly (meth) acrylate, styrene resins such as polystyrene, nylon 6 or nylon 66, etc. It is preferable to use a plastic film containing a resin such as a polyamide resin or an ABS resin (acrylonitrile-styrene-butadiene copolymer resin).
Among these, an acrylic resin film which is excellent in weather resistance and moldability, has excellent transparency due to its low refractive index, and is inconspicuous in scratches is preferable.
As the resin component forming the base material layer, only one type may be used, or two or more types may be mixed and used. Further, the base material layer may be formed of a single-layer film of these resins, or may be formed of a multi-layer film made 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 "methacryl", and other similar substances with (meth) have the same meaning.

The base material layer is subjected to physical or chemical surface treatment such as an oxidation method or an unevenness method on one or both sides, if necessary, in order to improve the adhesion to the metal layer, the primer layer described later, and the like. May be. Examples of the oxidation method performed as the surface treatment of the base material layer include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone ultraviolet treatment method and the like. Further, examples of the unevenness method performed as the surface treatment of the base material layer include a sandblast method and a solvent treatment method. These surface treatments are appropriately selected according to the type of resin component constituting the base material layer, and from the viewpoint of effect, operability, and the like, a corona discharge treatment method is preferable.

In a general decorative sheet, a colorant or the like is added to the base material layer for the purpose of concealing the discoloration caused by the resin burning when the molding resin layer is formed by injection molding. It is often colored by plastic or painted to adjust the color. Although these treatments may be performed in the present invention as well, from the viewpoint of adjusting the visible light transmittance of the metallic decorative sheet to a predetermined value, the group is highly transparent without being excessively colored or painted. It is desirable to use a material layer.

The base layer has a haze of JIS K7136: 2000 of preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less.
Further, the base material layer preferably has a visible light transmittance of JIS K7361-1: 1997 of 85% or more, and more preferably 90% or more.

The thickness of the base material layer is appropriately set according to the use of the metallic decorative sheet, and 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 material layer is within the above range, the metal-like decorative sheet can be provided with even better three-dimensional moldability, designability, and the like.

<Metal layer>
The metal layer is a layer provided on the base material layer to impart metallic luster to the metallic decorative sheet. In the present invention, for example, as shown in FIG. 2, the metal layer is formed so as to have a sea-island structure having a plurality of islands containing metal and a sea portion located between the islands.
In the present invention, the metal layer preferably has sufficient light transmission. That is, in the metal layer, when light is irradiated from the light source on the base material layer side to the metal-like decorative sheet of the present invention, at least a part of the irradiated light passes through the metal layer, and the metal layer It is preferable that the surface can recognize the design property due to the transmitted light. Further, it is preferable that the metal layer can exhibit a high-quality metallic luster when the light source is turned off. In order for the metal layer to have sufficient light transmission and to exhibit a high-quality metallic luster when the light source is turned off, the metal layer has islands and seas, and the adhesive layer has an adhesive layer with respect to the thickness of the seas. It is important that the ratio of the thickness of the filled portion is less than 100%. For example, a solid metal layer having no islands and seas can be imparted with light transmission by reducing the thickness of the metal layer, but it is difficult to exhibit a high-quality metallic luster when the light source is turned off. be. Further, as will be described later, even if the metal layer has an island portion and a sea portion, if the ratio of the thickness of the filling portion of the adhesive layer to the thickness of the sea portion is 100%, the light transmission is insufficient. Become.

The metal forming the metal layer is not particularly limited as long as it is a metal that can impart a metallic luster when the light source is turned off and a design due to transmitted light from the light source when the light source is turned on. , Nickel, copper, silver, gold, platinum, zinc, alloys containing at least one of these, and metal oxides thereof. Among these, tin, indium and gold are preferably mentioned from the viewpoint that the above-mentioned sea-island structure can be easily obtained. Indium is particularly preferable because it has excellent metallic luster and good weather resistance. Furthermore, since indium has a low melting point, indium tends to have the above-mentioned sea-island structure in particular. Therefore, when the metal layer is indium, it is effective in that a metallic luster is given when the light source is turned off, and a design due to the transmitted light from the light source is easily given when the light source is turned on.

As a method for forming the metal layer, a physical vapor deposition method (PVD) such as a vacuum vapor deposition method, a sputtering method, or an ion plating method, plasma CVD using plasma, or contact heat of a material gas using a heating catalyst is used. Examples thereof include a chemical vapor deposition method (CVD) such as a catalytic chemical vapor deposition method (Cat-CVD) for decomposition. Among these, the vacuum vapor deposition method, which can process any material, is preferable. That is, as the metal layer, a physical vapor deposition film is preferable, and among them, a vacuum deposition film is preferable.

From the viewpoint of metallic luster and moldability, the thickness H1 per island is preferably formed to be 30 to 100 nm, more preferably 40 to 80 nm.

The thickness H1 per island can be adjusted, for example, by the time of vapor deposition (the longer the vapor deposition time, the greater the thickness H1 per island).

In the present invention, assuming that each of the islands of the metal layer is circular, the size of the islands is 75 nm when the average value of the diameters calculated from the area of each island is defined as the "size of the islands". It is preferably 400 nm or more and 400 nm or less.
When the size of the island is 75 nm or more, the metallic luster is excellent, and the design of the metallic decorative sheet can be easily improved.
On the other hand, when the size of the island portion is 400 nm or less, the density of the island portion of the metal layer does not become too high, and the metallic luster after molding tends to be excellent.
The size of the island portion is more preferably 160 nm or more and 350 nm or less, and further preferably 200 nm or more and 300 nm or less.

In this specification, the size of the island is calculated by the following method.
First, the surface of the metal layer is observed with a scanning electron microscope (SEM) to acquire an image. The observation conditions are preferably as follows.
<Observation conditions>
Acceleration voltage: 5kV
Emission current: 10 μA
Pixel size: 9.5 to 10.0 nm
Working distance: 15mm
Observation magnification: 10,000 times Gradation: 8 bits

Next, 800,000 to 900,000 pixels are cut out from the image obtained by the observation under the above conditions. The cut out image is binarized based on Otsu's method (Otsu's method).
Next, a square frame containing 50 or more and 100 or less islands is superimposed on the photograph taken. Let the length of one side of the frame be L [nm]. “L” represents the actual size on the sample, and can be calculated based on, for example, the pixel size or scale bar of the SEM photograph.
Next, the number of islands including the whole in the frame (n ₁ ), the number of islands in which it is recognized that 1/2 or more and less than 1 of the area of the island is present in the frame (n ₂ ), the said. Count _{the number of islands (n 3} ) where less than half of the area of the island is found to exist within the frame. Based on the counted n ₁ , n ₂ and n ₃ , "n" represented by the following formula (i) is fictitious as the number of islands existing in the frame.
n = n ₁ + (3n ₂ + n ₃ ) / 4 (i)
Next, the total area of the islands in the frame (the total area of the areas recognized as islands by the binarization process) is calculated, and the total area is set to "S [nm ² ]".
Then, based on S [nm ² ] and the number of islands (n) in the frame calculated by the formula (i), "a" represented by the following formula (ii) is added to one island in the frame. It is assumed to be the area around [nm ^2].
a = S / n (ii)
Since the islands have an amorphous shape as shown in the electron micrograph of FIG. 2, each island is assumed to be circular in calculating the island size in the present specification. The diameter of the island, which is assumed to be circular, is defined as the "size of the island".
In the present specification, the size d [nm] of the island portion is calculated from the formula (iii) from ^{the area a [nm 2} ] per island portion at 20 locations. Then, the average value of "d" at 20 points is defined as the island size D [nm] in the present specification.
d = (4a / π) ^1/2 (iii)

The size of the islands can be adjusted, for example, by the time of deposition (the size increases as the time of deposition increases).

<Adhesive layer>
The metallic decorative sheet has an adhesive layer on the surface of the metal layer opposite to the base material layer. The adhesive layer in the present invention is a layer for adhering a base material layer or a metal layer to an adherend. The adhesive layer is preferably composed 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. Further, the adhesive layer is more preferably a pressure-sensitive adhesive layer from the viewpoint that the ratio of the thickness of the filled portion to the thickness per sea portion can be easily adjusted. Further, the adhesive layer is preferably in direct contact with the metal layer from the viewpoint that the ratio of the thickness of the filled portion to the thickness per sea portion can be easily adjusted.

In the present invention, the ratio of the thickness of the filled portion to the thickness of one sea portion is 10% or more and less than 100%.
When the ratio of the thickness of the filled portion to the thickness of one sea portion is less than 10%, the adhesive force between the metal layer and the adhesive layer tends to be small, so that it is difficult to suppress chipping.
On the other hand, when the ratio of the thickness of the filled portion to the thickness of one sea portion is 100%, the light transmission becomes insufficient, and for example, it becomes difficult to improve the design when the light source is lit.
The ratio of the thickness of the filled portion to the thickness of one sea portion is preferably 10% to 80%, more preferably 15% to 80%.

FIG. 3 is a plan view showing the dimensions of the metal-like decorative sheet shown in FIG. 1 in an enlarged manner.
In the present specification, the ratio of the thickness H3 of the filling portion 122a to the thickness H2 per sea portion is "(thickness H3 of the filling portion 122a / thickness H2 per sea portion) x 100 (%)". The thickness H2 per sea portion is represented by the average of the thicknesses H1 and H1'per islands on both sides of the target sea portion ((H1 + H1') / 2).
Further, the thickness H3 of the filling portion 122a is preferably calculated in the same manner as the thickness per island portion described above.
The ratio of the thickness of the filled portion to the thickness per sea portion (sometimes referred to as “filling rate” in the present specification) is, for example, the nip pressure, line speed, and adhesive layer when the adhesive layers are bonded together. (When the nip pressure is increased, the filling rate tends to increase. When the line speed is decreased, the filling rate tends to increase. Also, the elastic modulus of the adhesive layer tends to increase. The smaller the value, the larger the filling rate tends to be.)
In order to adjust the ratio of the thickness of the filled portion to the thickness of one sea portion, the nip pressure is preferably 0.4 to 3.0 MPa, more preferably 0.4 to 2.7 MPa. The line speed is preferably 0.1 to 1.5 m / min, more preferably 0.3 to 1.0 m / min. The elastic modulus of the adhesive layer ^{is preferably 1.0 × 10 5 to} 1.0 × 10 ⁸ N / m ² at 23 ° C., and 1.0 × 10 ^{6 to} 1.0 × 10 ⁷ N. It is more preferably / m ^2.

The thickness H1 per island, the thickness H2 per sea, and the thickness H3 of the filling portion 122a are the average values of the values at 20 locations measured from the cross-sectional image taken by SEM. Calculate from. Further, the observation by SEM is carried out after sufficiently acclimatizing the vapor-deposited film in an environment having a temperature of 23 ° C. ± 5 ° C. and a humidity of 40 to 65%. Further, the acceleration voltage at the time of SEM shooting is in the range of 1 to 5 kV, and the pixel size of the image is 0.9 to 1.0 nm.

As the resin used for the adhesive layer, a general-purpose acrylic resin, urethane resin, polyester resin, silicone resin, vinyl chloride resin or vinyl acetate resin, or a mixture or copolymer of two or more of these is used. It is preferable to use it. From the viewpoint of adhesive strength, an acrylic resin is more preferable.
The thickness of the adhesive layer is preferably 20 to 100 μm, more preferably 30 to 70 μm. By setting the thickness of the adhesive layer to 20 μm or more, it is possible to easily improve the adhesion with the metal layer, and by setting the thickness to 100 μm or less, it is possible to easily prevent the surface hardness of the metal-like decorative sheet from being lowered.

From the viewpoint of reducing the interfacial reflectance between the adherend made of the transparent resin and the adhesive layer, the refractive index of the adhesive layer is preferably 1.4 to 1.6.

The glass transition temperature Tg of the adhesive layer is preferably 0 to 30 ° C, more preferably 5 to 28 ° C, and even more preferably 10 to 26 ° C.
By setting the glass transition temperature to 0 ° C. or higher, resistance to chipping (chipping resistance) can be easily improved, heat resistance is improved, and deterioration of the surface smoothness of the decorative molded product is suppressed. It will be easier to do. Further, by setting the glass transition temperature to 30 ° C. or lower, it becomes easy to suppress a decrease in chipping resistance due to a decrease in adhesion. Further, when the glass transition temperature is in this range (0 to 30 ° C.), it becomes easy to balance the chipping resistance of the decorative molded product with the smoothness of the surface of the metallic decorative sheet at a high temperature.

<Unfilled part>
The unfilled portion indicates a portion of the sea portion of the metal layer in which the adhesive layer is not filled. Examples of the non-filled portion include various materials such as gas such as air and nitrogen, liquid such as water, and solid such as resin.
The refractive index of the material of the unfilled portion is preferably 1.0 to 1.3.
Further, the unfilled portion is preferably formed of gas, and more preferably formed of air.

<Primer layer>
The primer layer is a layer provided as necessary for the purpose of improving the adhesion between the metal layer and the layer adjacent to the metal layer, and as a base when the metal layer is formed by thin film deposition. The primer layer is provided between the base material layer and the metal layer, for example, and in that case, the adhesion between the base material layer and the metal layer can be improved. The material forming the primer layer is not particularly limited as long as it can improve the adhesion between these layers, but for example, an acrylic resin, a polyurethane resin, an acrylic-urethane copolymer resin, a polyester resin, or the like. Resin can be mentioned. For example, when the base material layer contains an acrylic resin, the primer layer preferably contains an acrylic resin.

The thickness of the primer layer is not particularly limited, but is usually about 0.5 to 2.5 μm, preferably about 1 to 2 μm. The primer layer may contain additives such as an ultraviolet absorber and a light stabilizer.

<Peeling layer>
The metallic decorative sheet may have a release layer on the side of the adhesive layer opposite to the metal layer. The release layer in the present invention is a layer for protecting the adhesive layer of the decorative film. The peeling layer is preferably one that can be easily peeled from the adhesive layer before or after molding. A mold release agent is used for the release layer in order to improve the release property. Examples of the release agent include a melamine resin release agent, a silicone release agent, a fluorine resin release agent, a cellulose resin release agent, a urea resin release agent, a polyolefin resin release agent, and a paraffin release agent. Mold release agents such as mold agents, acrylic resin-based mold release agents, and composite mold release agents thereof are preferable. Of these, a silicone-based release agent is particularly preferable.

The release layer in the present invention can be formed by using the above-mentioned mold release agent and a binder resin. As the binder resin, it is preferable to use a thermoplastic resin, for example, 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. And so on. The release layer is an ink prepared by dissolving or dispersing the above-mentioned mold release agent and binder resin with necessary additives in an appropriate solvent, and gravure coating method, roll coating method, comma coating method, and gravure printing. It can be formed by coating and drying by a known means such as a method, a screen printing method, and a gravure reverse roll coating method.

In the present invention, as the release layer, a release film in which a release layer containing the above-mentioned release agent is provided on one side of a known resin film such as a polyester film may be used.

<Backer layer>
The metallic decorative sheet may have a backer layer on the side opposite to the metal layer of the adhesive layer.
The backer layer has, for example, a role of increasing the strength of the metal-like decorative sheet and the metal-like decorative molded body and maintaining the shape of the molded body.

The backer layer is preferably made of a plastic film. The plastic film of the backer layer may be the same as the plastic film exemplified in the base material layer.
The thickness of the backer layer is preferably 100 μm or more and less than 1000 μm, and more preferably 150 μm or more and 500 μm or less.

<Second adhesive layer>
When the metallic decorative sheet has a backer layer, it may have a second adhesive layer on the side opposite to the adhesive layer of the backer layer.
The second adhesive layer has a role of improving the adhesion with the adherend, for example. The second adhesive layer can be formed from the same resin as the resin used for the above-mentioned adhesive layer.
The thickness of the second adhesive layer is preferably 20 μm or more and 100 μm or less, and more preferably 30 μm or more and 70 μm or less.

<Other layers>
The metallic decorative sheet may have a layer other than those exemplified above.

<Visible light transmittance>
The metal-like decorative sheet preferably has an average spectral transmittance of more than 5.0% and preferably 5.5% or more at a wavelength of 380 to 780 nm. If the visible light transmittance is too high, the high-quality metallic luster when the light source is turned off tends to decrease. Therefore, the visible light transmittance of the metallic decorative sheet is preferably 10.0% or less.

[Manufacturing method of metallic decorative sheet]
In the method for producing a metallic decorative sheet of the present invention, the metallic decorative sheet has some of the above-mentioned layers, and the filled portion and the unfilled portion of the sea portion of the metal layer have a predetermined relationship. There is no particular limitation.
When the release layer is provided, the metal-like decorative sheet can be manufactured as follows.
One embodiment of the method for producing a metallic decorative sheet of the present invention has a metallic layer having a plurality of islands containing metal and a sea portion located between the islands on a base material layer. It has a laminating step of laminating the adhesive surface of the adhesive sheet having the adhesive layer on the release layer on the surface of the sheet on the metal layer side.
In the thickness direction of the sea portion, there is a filled portion in which the adhesive layer is filled and a non-filled portion in which the adhesive layer is not filled, and the ratio of the thickness of the filled portion to the thickness per sea portion is 10%. As described above, the laminating step is performed so as to be less than 100%.

In the above manufacturing method, the metallic sheet can be obtained, for example, by forming a metal layer having a plurality of islands containing metal and a sea portion located between the islands on a base material layer. can.
Further, in the above manufacturing method, the adhesive sheet can be obtained by a step of forming an adhesive layer on a release layer such as a release film, for example.

[Metallic decorative molded body]
FIG. 4 is a cross-sectional view showing an embodiment of the metallic decorative molded article of the present invention. The metallic decorative molded body 200 of the present invention is formed by integrating the adherend 210 with the metallic decorative sheet 100 of the present invention. That is, the metal-like decorative molded body 200 of the present invention is at least the metal-like decorative molded body 200 in which the adherend 210 and the metal-like decorative sheet 100 of the present invention are laminated, and the metal-like decorative molded body 200 is metal-adjusted. The metal-like decorative sheet 100 is laminated so that the adhesive layer 130 of the decorative sheet 100 is located on the adherend side 210. The metallic decorative molded article of the present invention has at least an adherend 210, an adhesive layer 130, a metal layer 120 and a base material layer 110, and if necessary, the above-mentioned primers as shown in the figure. At least one layer, such as layer 140, may be further provided.

<Subject>
The adherend used for the metal-like decorative molded body of the metal-like decorative sheet of the present invention is not particularly limited, and examples thereof include a molded body made of glass, ceramics, resin, or the like.
The adherend may be one that has been molded into the shape of the molded body in advance, or may be the shape of the molded body at the time of decorative molding such as vacuum forming or insert molding.
The thickness of the adherend is not particularly limited, but is usually 1 mm or more, preferably 1 to 10 mm.
It is possible to color by blending a colorant or the like, or to apply paint to adjust the color, but from the viewpoint of adjusting the visible light transmittance of the metal-like decorative sheet to a predetermined value, It is desirable to use a highly transparent adherend without excessive coloring or painting.

The adherend preferably has a haze of JIS K7136: 2000 of 5.0% or less, more preferably 3.0% or less, and even more preferably 2.0% or less.
Further, the adherend preferably has a visible light transmittance of JIS K7361-1: 1997 of 80% or more, and more preferably 85% or more.

[Manufacturing method of metallic decorative molded article]
For example, a metal-like decorative molded body can be manufactured by vacuum forming having the following steps (y1) to (y2).
(Y1) A laminated body is produced in which the surface of the metallic decorative sheet on the adhesive layer side and the adherend are adhered to each other.
(Y2) The surface of the laminated body on the adherend side is arranged toward the mold and vacuum formed.

[Display device]
FIG. 5 is a cross-sectional view showing an embodiment of the display device of the present invention. The display device 300 shown in FIG. 5 has a light source 310 and a metallic decorative molded body 200 on the front surface of the light source 310. Such a display device 300 is used, for example, as an interior member or an exterior member of a moving body such as a vehicle such as an automobile or a railroad, an aircraft, a ship, or a spacecraft. Among them, it is preferably used for automobile exterior backlit products such as automobile backlit type blinkers, B pillars, side visors, brake lamps, and garnishes, which require strong transmitted light intensity from the light source 310. In the illustrated example, the display device 300 is shown in a flat plate shape, but may have a curved shape.

<Light source>
The light source 310 is an element that emits electromagnetic waves such as visible light, infrared light, and radio waves, and is arranged on the back side of the metal-like decorative molded body 200. The light source 310 is preferably an element that emits visible light.
The type of the light source 310 is not particularly limited.
Examples of elements whose light source emits visible light include LEDs, fluorescent lamps, light bulbs, halogen lamps, decharge lamps, OLEDs, laser diodes, liquid crystal displays, plasma displays, organic EL displays, and the like. , Fluorescent lamps, light bulbs, halogen lamps, decharge lamps, OLEDs, laser diodes are preferable. Further, when the light source is an element that emits visible light, the light source may be monochromatic or multicolored. Further, when the light source is an element that emits visible light, the light source may display information. The information to be displayed may be a still image or a moving image.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to the embodiments described in the examples.

1. 1. Measurement and Evaluation Various characteristics (chipping resistance, visible light transmittance) related to the metallized molded article obtained in Examples and Comparative Examples were evaluated according to the following procedure. The results are shown in Table 1.

1-1. Chipping resistance The chipping resistance test was carried out by a gravure test in accordance with standard number SAE J-400, standard name Test for Chip Response of Surface Coatings. FIG. 6 is a schematic view of a gravure test apparatus for evaluating the chipping resistance of the decorative molded product obtained in Examples and Comparative Examples. Using the Grabello test apparatus 400, at -20 ° C, No. 7 crushed stone 410 (100 g) was added to the metal-like decorative molded body 200 obtained in Examples and Comparative Examples on the test support 420 (material: ceramic). After irradiating the metal-like decorative molded body 200 in the vertical direction at a distance of 350 mm at an injection pressure of 0.4 MPa for 1 second, the degree of peeling of the film of the metal-like decorative molded body 200 was confirmed. The evaluation criteria are as follows.
<Evaluation criteria>
A: Visually observe, there is no peeling of the film.
B: Visually observed, there is almost no peeling of the film.
C: Visually observed, the film is peeled off.

1-2. Visible light transmittance The visible light transmittance (measurement wavelength: 380 to 780 nm) of the metal-like decorative molded body sheet is measured using a spectrophotometer (trade name V-670 manufactured by JASCO Corporation) (light incident surface). Was on the polyester film side). When the visible light transmittance is 5.5% or more, it can be said that the light transmittance is good and the design when the light source is lit is significantly excellent (A evaluation). Further, if the visible light transmittance is more than 5.0% and less than 5.5%, the light transmittance is within the permissible range, and it can be said that the design is excellent when the light source is lit (B evaluation). Further, when the visible light transmittance is 5.0% or less, the light transmittance is not sufficient, and it can be said that the design is slightly inferior when the light source is lit (C evaluation).

2. Preparation of Metal-like Decorative Sheet and Metal-like Decorative Mold [Example 1]
A coating liquid for forming a primer layer containing an acrylic polyol and an isocyanate-based curing agent was applied onto an acrylic film having a thickness of 125 μm and dried to form a primer layer having a thickness of 2 μm.

Next, a metal layer made of indium (In) was formed on the primer layer by a vacuum deposition method so as to have a thickness of 50 nm. By SEM observation, it was confirmed that the formed metal layer had a sea-island structure.

Next, an epoxy-based cross-linking agent (manufactured by Soken Kagaku Co., Ltd., trade name: E-AX) was added to 100 parts by mass of an acrylic pressure-sensitive adhesive (manufactured by Soken Kagaku Co., Ltd., trade name: SK Dyne 2094, solid content 25% by mass). , 0.27 parts by mass of solid content) was mixed to obtain a composition for an adhesive layer. The composition for the adhesive layer is applied to the release-treated surface of a polyester film (manufactured by Toyobo Co., Ltd., trade name: E7304) having a thickness of 38 μm that has been subjected to silicone peeling treatment so that the thickness after drying is 40 μm, and the adhesive is pressure-sensitive. A layer (pressure sensitive adhesive layer) was formed. Then, an adhesive layer was bonded onto the metal layer under the conditions of a nip pressure of 0.4 MPa and a line speed of 1.0 m / min to obtain a metal-like decorative sheet of Example 1. From the cross-sectional SEM image of the obtained metallic decorative sheet, the ratio (filling rate) of the thickness of the filled portion to the thickness of one sea portion was calculated.

Next, it was attached to a plate-shaped transparent ABS having a thickness of 3 mm via the adhesive layer side of the metallic decorative sheet. A mold having a desired molding shape was prepared, the surface on the ABS side was arranged toward the mold, and vacuum forming was performed (ABS plate reaching temperature 160 ° C.) to obtain a metal-like decorative molded product of Example 1.

[Example 2]
A metal-like decorative molded article of Example 2 was obtained in the same manner as in Example 1 except that the adhesive layer was bonded onto the metal layer at a nip pressure of 1.0 MPa and a line speed of 1.0 m / min.

[Example 3]
A metal-like decorative molded article of Example 3 was obtained in the same manner as in Example 1 except that a metal layer made of tin (Sn) was formed to have a thickness of 50 nm by a vacuum vapor deposition method.

[Example 4]
A metal-like decorative molded article of Example 4 was obtained in the same manner as in Example 1 except that the adhesive layer was bonded onto the metal layer at a nip pressure of 2.0 MPa and a line speed of 0.3 m / min.

[Example 5]
A metal-like decorative molded article of Example 5 was obtained in the same manner as in Example 1 except that the adhesive layer was bonded onto the metal layer at a nip pressure of 2.7 MPa and a line speed of 0.3 m / min.

[Example 6]
A metal-like decorative molded article of Example 6 was obtained in the same manner as in Example 1 except that the adhesive layer was bonded onto the metal layer at a nip pressure of 2.0 MPa and a line speed of 1.0 m / min.

[Comparative Example 1]
A metal-like decorative molded article of Comparative Example 1 was obtained in the same manner as in Example 1 except that the adhesive layer was bonded onto the metal layer at a nip pressure of 0.4 MPa and a line speed of 3.0 m / min.

[Comparative Example 2]
A metal-like decorative molded article of Comparative Example 2 was obtained in the same manner as in Example 1 except that the adhesive layer was bonded onto the metal layer at a nip pressure of 2.7 MPa and a line speed of 0.1 m / min.

From the results in Table 1, it can be confirmed that the metal-like decorative sheet of the example has good light transmission while suppressing chipping, and is excellent in design when the light source is lit.

100: Metal-like decorative sheet 110: Base material layer 120: Metal layer 121: Island part 122: Sea part 122a: Filled part 122b: Unfilled part 130: Adhesive layer 140: Primer layer 200: Metal-like decorative molded body 210: Adhesion 300: Display 310: Light source 400: Clavero test device 410: Crushed stone 420: Test support

Claims (8)

A metal-like decorative sheet having a base material layer, a metal layer, and an adhesive layer in this order.
The metal layer has a plurality of islands containing metal and a sea portion located between the islands.
The sea portion has a filled portion in which the adhesive layer is filled and a non-filled portion in which the adhesive layer is not filled in the thickness direction.
A metal-like decorative sheet in which the ratio of the thickness of the filling portion to the thickness of one sea portion is 10% or more and less than 100%. The metallic decorative sheet according to claim 1, wherein the ratio of the thickness of the filled portion to the thickness of one sea portion is 10% or more and 80% or less. The metal-like decorative sheet according to claim 1 or 2, wherein the thickness of each island is 30 to 100 nm. The metal-like decorative sheet according to any one of claims 1 to 3, wherein the metal layer contains indium or tin. The metal-like decorative sheet according to any one of claims 1 to 4, which has a release layer on the side of the adhesive layer opposite to the metal layer. A metal-like decorative molded body having the metal-like decorative sheet according to any one of claims 1 to 5 and an adherend. A display device having the metallic decorative molded article according to claim 6 on the front surface of the light source. An adhesive layer is provided on the release layer on the surface of the metal-like sheet having a metal layer having a plurality of islands containing metal and a sea portion located between the islands on the base material layer on the metal layer side. It has a laminating process to laminate the adhesive surface of the adhesive sheet,
In the thickness direction of the sea portion, there is a filled portion in which the adhesive layer is filled and a non-filled portion in which the adhesive layer is not filled, and the ratio of the thickness of the filled portion to the thickness per sea portion is 10%. As described above, a method for manufacturing a metallic decorative sheet, wherein the laminating step is performed so as to be less than 100%.

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