JP7319078B2 - Electromagnetic wave permeable metallic luster article - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electromagnetic wave transparent metallic luster article.

BACKGROUND ART Conventionally, members having electromagnetic wave permeability and metallic luster have been suitably used for devices that transmit and receive electromagnetic waves because they have both a luxurious appearance derived from the metallic luster and electromagnetic wave permeability.
For example, there is a demand for metallic lustrous articles having both brilliance and electromagnetic wave permeability, such as front grills and emblems, which are decorative cover members for millimeter-wave radars mounted on the front part of automobiles.

Millimeter-wave radar transmits electromagnetic waves in the millimeter-wave band (frequency of about 77 GHz, wavelength of about 4 mm) in front of the vehicle, receives reflected waves from the target, measures and analyzes the reflected waves, It can measure the distance, target direction, and size.
The measurement results can be used for inter-vehicle distance measurement, automatic speed adjustment, automatic brake adjustment, and the like.
The front portion of the automobile where such a millimeter wave radar is installed is, so to speak, the face of the automobile, and is a portion that has a great impact on the user. However, if metal is used for the front portion of the automobile, the transmission and reception of electromagnetic waves by the millimeter-wave radar is substantially impossible or interferes. Therefore, in order not to impair the function of the millimeter wave radar and not to impair the design of the automobile, there is a need for a metallic luster article having both luster and electromagnetic wave permeability.

This kind of metallic glossy article is used not only for millimeter wave radar but also for various devices that require communication, such as door handles of automobiles equipped with smart keys, in-vehicle communication devices, mobile phones, electronic devices such as personal computers, etc. is expected to be applied. Furthermore, in recent years, with the development of IoT technology, it is expected to be applied in a wide range of fields, such as household appliances such as refrigerators and household appliances, where communication has not been performed in the past.

With respect to members with metallic luster, Japanese Patent Application Laid-Open No. 2007-144988 (Patent Document 1) discloses a resin product containing a metal coating made of chromium (Cr) or indium (In). This resin product comprises a resin substrate, an inorganic undercoat film containing an inorganic compound formed on the resin substrate, and a glittering and discontinuous film formed on the inorganic undercoat film by a physical vapor deposition method. The structure includes a metallic coating of chromium (Cr) or indium (In). As an inorganic base film, Patent Document 1 describes (a) a thin film of a metal compound, for example, a titanium compound such as titanium oxide (TiO, TiO ₂ , Ti ₃ O ₅ etc.); silicon oxide (SiO, SiO ₂ etc.), nitriding silicon compounds such as silicon ( _{Si3N4 , etc. )} ; aluminum compounds such as aluminum _oxide ( _Al2O3 ); iron compounds such as iron oxide ( _Fe2O3 ); selenium compounds such as selenium oxide (CeO); Zircon compounds such as zircon (ZrO); zinc compounds such as zinc sulfide ( _ZnS ); A coating made of an inorganic paint is used.

On the other hand, in Japanese Patent Application Laid-Open No. 2009-298006 (Patent Document 2), not only chromium (Cr) or indium (In), but also aluminum (Al), silver (Ag), and nickel (Ni) are formed as metal films. An electromagnetic wave transparent photoluminescent resin product is disclosed.
Japanese Patent Application Laid-Open No. 2010-5999 (Patent Document 3) discloses that a metal film layer is formed on a base material sheet, and the base material sheet is subjected to heat treatment while applying tension, thereby forming an electromagnetic wave transparent metal having cracks. A method for manufacturing a membrane decorating sheet is described.

JP 2007-144988 A Japanese Patent Application Laid-Open No. 2009-298006 JP-A-2010-5999

Since the metal layer in such a metallic luster article is configured as a metal layer including a plurality of portions that are discontinuous to each other in at least a portion such as an island structure in order to ensure electromagnetic wave permeability, the surface area wide and therefore prone to oxidation.
However, when the metal layer is oxidized, it loses its metallic luster. Therefore, an article with metallic luster in which oxidation of the metal layer is suppressed has been desired.
The present invention has been made in view of the above, and an object thereof is to provide an electromagnetic wave transmitting metallic luster article in which oxidation of the metal layer is suppressed.

The present inventors have made intensive studies to solve the above problems, and as a result, have found that the above problems can be solved by an electromagnetic wave transmitting metallic glossy article having a barrier layer.

One aspect of the present invention comprises a base, a metal layer formed on the base, and a barrier layer formed on a surface of the metal layer opposite to the base, wherein the metal layer comprises: The present invention relates to an electromagnetic wave transmitting metallic lustrous article including a plurality of portions that are at least partially discontinuous with each other.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, it is preferable to further include an indium oxide-containing layer between the substrate and the metal layer.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the indium oxide-containing layer is preferably provided in a continuous state.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the indium oxide-containing layer contains indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), or indium zinc oxide (IZO). preferably included.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the indium oxide-containing layer preferably has a thickness of 1 nm to 1000 nm.

One aspect of the electromagnetic wave transmitting metallic luster article of the present invention preferably further comprises a barrier layer formed between the metal layer and the substrate.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the barrier layer is composed of at least one oxide, nitride, carbide, oxynitride, oxycarbide, nitride carbide, and oxynitride carbide of at least one of metals and semimetals. It preferably contains at least one selected from the group consisting of:

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the barrier layer preferably contains at least one selected from the group consisting of AZO, ITO, AlO _x and SiO ₂ .

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the thickness of the metal layer is preferably 10 nm to 100 nm.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the ratio of the thickness of the metal layer to the thickness of the indium oxide-containing layer (thickness of the metal layer/thickness of the indium oxide-containing layer) is 0. 0.02 to 100.

One aspect of the electromagnetic wave transmitting metallic luster article of the present invention preferably has a sheet resistance of 100Ω/□ or more.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the plurality of portions may be formed in an island shape.

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the metal layer is aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), silver (Ag), or an alloy thereof. It is preferable that

In one aspect of the electromagnetic wave transmitting metallic luster article of the present invention, the substrate is preferably a substrate film, a resin molding substrate, a glass substrate, or an article to be imparted with metallic luster.

According to the present invention, it is possible to provide an electromagnetic wave transmitting metallic luster member in which oxidation of the metal layer is suppressed.

FIG. 1 is a schematic cross-sectional view of an electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of an electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 3 is an electron micrograph of the metal layer of the electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of an electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of an electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 6 is a schematic cross-sectional view of an electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of an electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 8 is a diagram for explaining a method for measuring the film thickness of the metal layer of the electromagnetic wave transmitting metallic luster article according to one embodiment of the present invention. FIG. 9 is a diagram showing a transmission electron micrograph (TEM image) of a cross section of a metal layer in one embodiment of the present invention.

One preferred embodiment of the present invention will be described below with reference to the accompanying drawings. In the following, only preferred embodiments of the present invention are shown for convenience of explanation, but of course, this is not intended to limit the present invention.

<1. Basic configuration>
FIG. 1 shows a schematic cross-sectional view of an electromagnetic wave transmitting metallic luster article (hereinafter referred to as "metallic luster article") 1 according to one embodiment of the present invention, and FIG. 3 shows a metallic luster article according to one embodiment of the present invention. 1 shows an electron micrograph (SEM image) of the metal layer of No. 1. FIG. Further, FIG. 9 shows a transmission electron micrograph (TEM image) of a cross section of the metal layer 12 having an island-like structure in one embodiment of the present invention.

A metallic luster article 1 includes a substrate 10 and a metal layer 12 formed on the substrate 10 . Moreover, it further includes a barrier layer 13 formed on the surface of the metal layer opposite to the substrate side.

A metal layer 12 is formed over the substrate 10 . Metal layer 12 includes a plurality of portions 12a. These portions 12a of the metal layer 12 are at least partially discontinuous, in other words, at least partially separated by gaps 12b. Since it is separated by the gap 12b, the sheet resistance of the article with metallic luster is increased and the interaction with radio waves is reduced, so that the radio waves can be transmitted. Each of these portions 12a may be an aggregate of sputtered particles formed by vapor deposition, sputtering, or the like of metal.

The term "discontinuous state" as used in this specification means a state in which they are separated from each other by the gap 12b and, as a result, are electrically insulated from each other. By being electrically insulated, the sheet resistance of the article with metallic luster is increased, and the desired electromagnetic wave permeability can be obtained. That is, according to the metal layer 12 formed in a discontinuous state, it is easy to obtain sufficient luster, and it is also possible to secure electromagnetic wave permeability. The form of discontinuity is not particularly limited, and includes, for example, an island structure, a crack structure, and the like. As shown in FIG. 3, the "island structure" means that the metal particles are independent from each other, and the particles are spread in a state that they are slightly separated from each other or partially in contact with each other. It is a structure.

A crack structure is a structure in which a metal thin film is divided by cracks.
The metal layer 12 having a crack structure can be formed, for example, by providing a metal thin film layer on a substrate film and bending and stretching the metal thin film layer to generate cracks in the metal thin film layer. At this time, the metal layer 12 having a crack structure can be easily formed by providing a brittle layer made of a material having poor stretchability, that is, being easily cracked by stretching, between the base film and the metal thin film layer. .

As described above, the mode in which the metal layer 12 becomes discontinuous is not particularly limited, but from the viewpoint of productivity, an island-like structure is preferable.

The electromagnetic wave transmittance of the metallic glossy article 1 can be evaluated, for example, by the amount of radio wave transmission attenuation. In the metallic glossy article 1, the radio wave transmission attenuation in the centimeter wave band (5 GHz) measured by the method described in the Examples column is preferably 10 [-dB] or less, and is 5 [-dB] or less. is more preferable, and 2 [-dB] or less is even more preferable. If it is larger than 10 [-dB], there is a problem that 90% or more of radio waves are cut off. There is a correlation between the radio wave transmission attenuation in the centimeter wave band (5 GHz) and the radio wave transmission attenuation in the millimeter wave radar frequency band (76 to 80 GHz). A metallic glossy article having excellent electromagnetic wave permeability in the wave band also has excellent electromagnetic wave permeability in the frequency band of millimeter wave radar.

The sheet resistance of the metallic glossy article 1 also has a correlation with the electromagnetic wave permeability. The sheet resistance of the metallic glossy article 1 is preferably 100 Ω/□ or more, and in this case, the radio wave transmission attenuation in the centimeter wave band (5 GHz) is about 10 to 0.01 [-dB]. The sheet resistance of the article with metallic luster is more preferably 200Ω/□ or more, and even more preferably 600Ω/□ or more. Moreover, it is particularly preferably 1000Ω/□ or more.
The sheet resistance of the metallic glossy article 1 can be measured by an eddy current measurement method according to JIS-Z2316-1:2014.

The radio wave transmission attenuation and sheet resistance of the metallic glossy article 1 are affected by the material, thickness, etc. of the metal layer 12 . In addition, when the metallic luster article 1 is provided with the indium oxide-containing layer 11 , it is also affected by the material, thickness, etc. of the indium oxide-containing layer 11 .

<2. Substrate>
Examples of the base 10 include resin, glass, and ceramics from the viewpoint of electromagnetic wave permeability.
The substrate 10 may be a substrate film, a resin molding substrate, a glass substrate, or an article to be imparted with metallic luster.
More specifically, the base film includes, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, polyamide, polyvinyl chloride, polycarbonate (PC), cycloolefin polymer (COP), polystyrene , polypropylene (PP), polyethylene, polycycloolefin, polyurethane, acrylic (PMMA), ABS, and other homopolymers or copolymers.

These members do not affect the brilliance or electromagnetic wave permeability. However, from the viewpoint of forming the indium oxide-containing layer 11 and the metal layer 12 later, it is preferable that the material can withstand high temperatures such as vapor deposition and sputtering. Acrylic, polycarbonate, cycloolefin polymer, ABS, polypropylene, polyurethane are preferred. Among them, polyethylene terephthalate, cycloolefin polymer, polycarbonate, and acrylic are preferable because they have a good balance between heat resistance and cost.

The base film may be a single layer film or a laminated film. The thickness is preferably, for example, about 6 μm to 250 μm from the viewpoint of ease of processing. In order to strengthen the adhesive force with the indium oxide-containing layer 11 and the metal layer 12, plasma treatment, easy-adhesion treatment, or the like may be performed.
When the substrate 10 is a substrate film, the metal layer 12 may be provided on at least a portion of the substrate film, and may be provided on only one side of the substrate film or may be provided on both sides.

It should be noted here that the base film is only one example of an object (substrate 10) on which the metal layer 12 can be formed. The substrate 10 includes, in addition to the substrate film as described above, a resin molding substrate, a glass substrate, and the article itself to which metallic luster is to be imparted. Examples of resin molding substrates and articles to which metallic luster is to be imparted include structural parts for vehicles, articles mounted on vehicles, housings for electronic equipment, housings for home appliances, structural parts, machine parts, and various automobiles. electronic equipment, furniture, household goods such as kitchen utensils, medical equipment, building material parts, other structural parts and exterior parts.

The metal layer 12 can be formed on any of these substrates, and may be formed on a portion of the surface of the substrate or on the entire surface of the substrate. In this case, the substrate 10 to which the metal layer 12 is to be applied preferably satisfies the same materials and conditions as those of the base film.

<3. Indium oxide-containing layer>
In addition, the electromagnetic wave transmitting metallic luster article 1 according to one embodiment may further include an indium oxide-containing layer 11 between the substrate 10 and the metal layer 12, as shown in FIG. The indium oxide-containing layer 11 may be provided directly on the surface of the substrate 10 or may be provided indirectly via a protective film or the like provided on the surface of the substrate 10 . The indium oxide-containing layer 11 is preferably provided continuously on the surface of the substrate 10 to which metallic luster is to be imparted, in other words, without any gaps. By being provided in a continuous state, it is possible to improve the smoothness and corrosion resistance of the indium oxide-containing layer 11, and thus the metal layer 12 and the electromagnetic wave transmitting metallic luster article 1, and the indium oxide-containing layer 11 can be made to have in-plane variations. It is also easy to form a film without

Thus, further providing an indium oxide-containing layer 11 between the substrate 10 and the metal layer 12, that is, forming the indium oxide-containing layer 11 on the substrate 10 and forming the metal layer 12 thereon. According to this method, the metal layer 12 can be easily formed in a discontinuous state, which is preferable. Although the details of the mechanism are not necessarily clear, when sputtered particles from metal vapor deposition or sputtering form a thin film on a substrate, the surface diffusivity of the particles on the substrate affects the shape of the thin film. It is considered that a discontinuous structure is easily formed when the temperature is high, the wettability of the metal layer to the substrate is low, and the melting point of the material of the metal layer is low. By providing the indium oxide-containing layer on the substrate, it is believed that the surface diffusibility of the metal particles on the surface is promoted, making it easier to grow the metal layer in a discontinuous state.

As the indium oxide-containing layer 11, indium oxide (In ₂ O ₃ ) itself can be used, or metal inclusions such as indium tin oxide (ITO) and indium zinc oxide (IZO) can be used. You can also However, ITO and IZO containing the second metal are more preferable in terms of high discharge stability in the sputtering process. By using these indium oxide-containing layers 11, a continuous film can be formed along the surface of the substrate. For example, an island-shaped discontinuous structure can be easily formed, which is preferable. Furthermore, as will be described later, in this case, the metal layer contains not only chromium (Cr) or indium (In), but also aluminum, which is usually difficult to form a discontinuous structure and difficult to apply to this application. Easier to include various metals.

The content ratio (content ratio = (SnO ₂ /(In ₂ O ₃ +SnO ₂ )) × 100), which is the mass ratio of tin oxide (SnO ₂ ) contained in ITO, is not particularly limited. .5 wt% to 30 wt%, more preferably 3 wt% to 10 wt%. Also, the content rate (content rate=(ZnO/(In ₂ O ₃ +ZnO))×100), which is the mass ratio of zinc oxide (ZnO) contained in IZO, is, for example, 2 wt % to 20 wt %. The thickness of the indium oxide-containing layer 11 is usually preferably 1000 nm or less, more preferably 50 nm or less, and even more preferably 20 nm or less, from the viewpoints of sheet resistance, radio wave transmission attenuation, and productivity. On the other hand, the thickness is preferably 1 nm or more in order to facilitate the discontinuity of the laminated metal layer 12, and more preferably 2 nm or more, and 5 nm or more in order to ensure the discontinuity. is more preferable.

<4. Metal layer>
It is desirable that the metal layer 12 has a relatively low melting point as well as being capable of exhibiting sufficient luster. This is because the metal layer 12 is preferably formed by thin film growth using sputtering. For this reason, a metal having a melting point of about 1000° C. or less is suitable for the metal layer 12, and examples thereof include aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), silver (Ag ) and an alloy containing the metal as a main component. In particular, Al and alloys thereof are preferred because of their brilliance, stability, price, and the like. Moreover, when using an aluminum alloy, it is preferable to make aluminum content into 50 mass % or more.

The thickness of the metal layer 12 is usually preferably 10 nm or more so as to exhibit sufficient brightness, while it is usually preferably 100 nm or less from the viewpoint of sheet resistance and radio wave transmission attenuation. For example, 15 nm to 70 nm is preferable, and 15 nm to 50 nm is more preferable. This thickness is also suitable for forming a uniform film with good productivity, and the appearance of the resin molded product, which is the final product, is also good. Note that the thickness of the metal layer 12 can be measured, for example, as follows.
(Method for measuring thickness of metal layer)
First, as shown in FIG. 8, a square region 3 having a side of 5 cm is appropriately extracted from the metallic luster article, and the center lines A and B of the vertical and horizontal sides of the square region 3 are respectively divided into quarters. A total of five obtained points "a" to "e" are selected as measurement points.
Next, a cross-sectional image (transmission electron micrograph (TEM image)) as shown in FIG. 9 is measured at each of the selected measurement points, and from the obtained TEM image, a field of view containing five or more metal parts 12a Extract corner regions.
The thickness of the metal layer in each viewing angle region is obtained by dividing the total cross-sectional area of the metal layer in the viewing angle region extracted at each of the five measurement locations by the width of the viewing angle region, and at each of the five measurement locations, Let the average value of the thickness of the metal layer in each viewing angle region be the thickness of the metal layer.

Also, for the same reason, the ratio of the thickness of the metal layer 12 to the thickness of the indium oxide-containing layer 11 (thickness of the metal layer 12/thickness of the indium oxide-containing layer 11) is in the range of 0.1 to 100. Preferably, the range of 0.3 to 35 is more preferred.

The equivalent circle diameter of the portion 12a of the metal layer 12 is not particularly limited, but is usually about 10 to 1000 nm. Also, the distance between the portions 12a is not particularly limited, but is usually about 10 to 1000 nm.

<5. Barrier layer>
The metallic luster article 1 comprises a barrier layer 13 on the surface of the metal layer 12 opposite to the substrate 10 side, as shown in FIGS. The barrier layer 13 only needs to be laminated on the metal layer 12, and does not necessarily have to completely fill the gap 12b.
The barrier layer is a layer for suppressing oxidation (corrosion) of the metal layer 12 . The barrier layer contains at least one selected from the group consisting of oxides, nitrides, carbides, oxynitrides, oxycarbides, nitride carbides, and oxynitride carbides of at least one of metals and semimetals. Examples of metals that can be used include aluminum, titanium, indium, and magnesium, and examples of metalloids that can be used include silicon, bismuth, and germanium.
Specifically, for example, ZnO+Al ₂ O ₃ (AZO), indium zinc oxide (IZO), indium tin oxide (ITO), silicon oxycarbonitride film (SiOCN), silicon oxynitride film (SiON), silicon nitride film (SiN ), SiO _x , AlO _x , AlON, TiO _x and the like can be used. Among them, it is preferable to use at least one selected from the group consisting of AZO, ITO, AlO _X and SiO ₂ .
In order to improve the performance of the barrier layer to suppress the oxidation (corrosion) of the metal layer 12 (hereinafter also referred to as “barrier property”), carbon atoms that make the network structure (mesh-like structure) in the barrier layer dense. , preferably containing nitrogen. In order to further improve transparency, it is preferable to contain oxygen. That is, the barrier layer preferably contains at least one carbide oxynitride of a metal and a metalloid.

Moreover, in order to improve barrier properties, it is preferable that the barrier layer is difficult to permeate water vapor. The degree of water vapor permeation of the barrier layer can be evaluated by various methods. In order to improve barrier properties, the water vapor permeation amount is preferably 5 g/m ² ·day or less, more preferably 3 g/m ² ·day or less, and 2 g/m ² ·day or less. is more preferred.

Although the thickness of the barrier layer 13 is not particularly limited, it is preferably 1 nm or more, more preferably 5 nm or more, and even more preferably 10 nm or more in order to improve barrier properties. In order to improve the electromagnetic wave permeability and the metallic luster of the appearance, the thickness is preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less.

In order to further suppress oxidation (corrosion) of the metal layer 12, a barrier layer may be further provided between the metal layer and the substrate as shown in FIGS.
When the article with metallic luster 1 has an indium oxide-containing layer, a barrier layer may be provided between the indium oxide-containing layer and the metal layer as shown in FIG. A barrier layer may be provided on the opposite side of the layer. Moreover, as shown in FIG. 7, both of them may be provided.

In addition to the metal layer, the indium oxide-containing layer, and the barrier layer described above, the article with metallic luster may include other layers depending on the application.
Other layers include an optical adjustment layer (color adjustment layer) such as a high refractive material for adjusting appearance such as color, and a protective layer (scratch resistant layer) for improving durability such as scratch resistance. , an easy adhesion layer, a hard coat layer, an antireflection layer, a light extraction layer, an antiglare layer, and the like.

<6. Production of metallic luster article>
An example of the method for manufacturing the article with metallic luster 1 will be described. Although not specifically described, a substrate other than the substrate film 10 can also be manufactured in the same manner.

For forming the metal layer 12 on the substrate 10, for example, a method such as vacuum deposition or sputtering can be used.

When the indium oxide-containing layer 11 is formed on the substrate 10, the indium oxide-containing layer 11 is formed prior to the formation of the metal layer 12 by vacuum deposition, sputtering, ion plating, or the like. However, sputtering is preferable because the thickness can be strictly controlled even in a large area.

The barrier layer is formed by a vacuum dry process such as evaporation, sputtering, or chemical vapor deposition (CVD). This makes it possible to obtain a very dense barrier layer with high barrier properties. Among these, the vapor deposition method is preferable. This is because the vapor deposition method is a process with a very high film formation speed and a high productivity process, so that the production efficiency is good. Particularly preferred is formation using a vapor deposition method utilizing arc discharge plasma. Arc discharge plasmas have been found to have very high electron densities, unlike the commonly used glow discharge plasmas. By using arc discharge plasma in the vapor deposition method, reactivity can be increased and a very dense barrier layer can be formed.

Arc discharge plasma can be formed by, for example, a pressure gradient plasma gun, a DC discharge plasma generator, a high frequency discharge plasma generator, etc. Among them, the pressure that can stably generate high-density plasma even during deposition is Preferably, a gradient plasma gun is used.

When the indium oxide-containing layer 11 is provided between the substrate 10 and the metal layer 12, the indium oxide-containing layer 11 and the metal layer 12 are brought into direct contact without any other layer such as the barrier layer 13 intervening. is preferred.

<7. Uses of Metallic Lustrous Articles and Metal Thin Films>
Since the metallic lustrous article 1 and the metallic thin film of the present embodiment have electromagnetic wave permeability, they are preferably used for devices, articles, and parts thereof that transmit and receive electromagnetic waves. For example, structural parts for vehicles, articles mounted on vehicles, housings for electronic devices, housings for home appliances, structural parts, machine parts, various automobile parts, electronic device parts, furniture, household goods such as kitchen utensils , medical equipment, building material parts, other structural parts and exterior parts.
More specifically, for vehicles, instrument panels, console boxes, door knobs, door trims, shift levers, pedals, glove boxes, bumpers, bonnets, fenders, trunks, doors, roofs, pillars, seats, steering wheels , ECU boxes, electrical components, engine peripheral parts, drive system/gear peripheral parts, intake/exhaust system parts, cooling system parts, and the like.
More specifically, as electronic equipment and home appliances, refrigerators, washing machines, vacuum cleaners, microwave ovens, air conditioners, lighting equipment, electric water heaters, televisions, clocks, ventilation fans, projectors, speakers, personal computers, mobile phones, etc. , smart phones, digital cameras, tablet PCs, portable music players, portable game machines, battery chargers, electronic information devices such as batteries, and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. Metallic glossy articles of Examples 1 to 10 and Comparative Example 1 were prepared, and the water vapor permeation amount, radio wave transmission attenuation (-dB), sheet resistance, 20° glossiness, and reflectance of the barrier layer were measured. A substrate film was used as the substrate 10 .
The details of the evaluation method are as follows.

(1) Amount of Water Vapor Permeation of Barrier Layer Using a water vapor permeability measuring device PERMATRAN-W Model 3/33 manufactured by MOCON, the water vapor permeability of a single barrier film was evaluated in an environment of 40° C. and 90% RH.

(2) Radio Wave Transmission Attenuation The radio wave transmission attenuation at 5 GHz was evaluated using a waveguide method measurement evaluation jig and a vector network analyzer MS4644B (Anritsu Corporation).

(3) Sheet resistance Using a non-contact resistance measuring device NC-80MAP (measurement upper limit: 3000 Ω / □) manufactured by Napson, in accordance with JIS-Z2316, a laminate of a metal layer and an indium oxide-containing layer is measured by an eddy current measurement method. The sheet resistance was measured as

(4) 20° Glossiness The 20° glossiness of the article with metallic luster was measured according to JIS Z 8741 (1997 edition). Specifically, the measurement was performed using PG-IIM (20° gloss measurement, manufactured by Nippon Denshoku Industries Co., Ltd.). The 20° glossiness was measured on the surface facing the metal layer.
The 20° glossiness is preferably 900 or more, more preferably 1100 or more, and particularly preferably 1300 or more. If it is less than 900, there is a problem that the luster is inferior and a metallic appearance cannot be obtained.

(5) Reflectance 0° reflectance at a wavelength of 550 nm was measured using a Hitachi spectrophotometer U-4100.
Then, the article with metallic luster was left under conditions of 60° C. and 95% RH, and the reflectance was similarly measured after 250 hours and 500 hours.
Also, the ratio of the reflectance after 500 hours to the initial reflectance (reflectance retention rate after 500 hours) was determined.

[Comparative Example 1]
A PET film (thickness: 125 µm, width: 340 mm) manufactured by Mitsubishi Plastics, Inc. was used as the base film.
First, a 5 nm thick ITO layer was directly formed on the substrate film along the surface thereof using DC magnetron sputtering. The temperature of the base film when forming the ITO layer was set to 130°C. The content of tin oxide (SnO ₂ ) contained in ITO (content=(SnO ₂ /(In ₂ O ₃ +SnO ₂ ))×100) is 10 wt %.

Then, alternating current sputtering (AC: 40 kHz) was used to form a 30 nm thick aluminum (Al) layer on the ITO layer to obtain a metallic luster article without a barrier layer. The obtained aluminum layer was a discontinuous layer. The temperature of the substrate film when forming the Al layer was set to 130°C.

[Examples 1 to 4]
Barrier layers of various thicknesses made of AZO were formed by DC magnetron sputtering on the aluminum layer of the metallic luster article without a barrier layer obtained in the same manner as in Comparative Example 1. An article with metallic luster was obtained. The temperature of the base film when forming the barrier layer was set to 130°C. AZO used was AZO-low n manufactured by Mitsubishi Materials. The thickness of the barrier layer was measured by the same method as the method for measuring the thickness of the metal layer.

[Example 5]
An article with metallic luster of Example 5 was obtained in the same manner as in Example 2, except that a barrier layer made of ITO was formed. The content of tin oxide (SnO ₂ ) contained in ITO (content=(SnO ₂ /(In ₂ O ₃ +SnO ₂ ))×100) was 30 wt %.

[Examples 6 and 7]
RF (13.6 MHz) power supply sputtering was used to form a barrier layer of AlO _x with various thicknesses on the aluminum layer of the metallic luster article without a barrier layer obtained in the same manner as in Comparative Example 1, Metallic luster articles of Examples 6 and 7 were obtained. The temperature of the base film when forming the barrier layer was set to room temperature.

[Examples 8 to 10]
RF (13.6 MHz) power supply sputtering was used to form a barrier layer made of _SiO2 of various thicknesses on the aluminum layer of the metallic luster article without a barrier layer obtained in the same manner as in Comparative Example 1, Metallic luster articles of Examples 8-10 were obtained. The temperature of the base film when forming the barrier layer was set to room temperature.

The results are shown in Table 1 below.

The articles with metallic luster of Examples 1 to 10 all had higher reflectance retention after 500 hours than the article with metallic luster of Comparative Example 1, which did not have a barrier layer. That is, the metallic lustrous articles of Examples 1 to 10 were able to suppress the oxidation (corrosion) of the aluminum layer as compared with the metallic lustrous article of Comparative Example 1, which did not have a barrier layer.

As for metals other than aluminum (Al) used in the above examples, metals with relatively low melting points such as zinc (Zn), lead (Pb), copper (Cu), and silver (Ag) It is believed that a discontinuous structure can be formed in a similar manner.

The present invention is not limited to the above-described embodiments, and can be embodied with appropriate modifications without departing from the gist of the invention.

INDUSTRIAL APPLICABILITY The metallic luster article according to the present invention can be used for devices, articles, and parts thereof that transmit and receive electromagnetic waves. For example, structural parts for vehicles, articles mounted on vehicles, housings for electronic devices, housings for home appliances, structural parts, machine parts, various automobile parts, electronic device parts, furniture, household goods such as kitchen utensils , medical equipment, building material parts, other structural parts and exterior parts, etc., where both good design and electromagnetic wave permeability are required.

Reference Signs List 1 metallic lustrous article 10 substrate 11 indium oxide-containing layer 12 metal layer 12a portion 12b gap 13 barrier layer

Claims (13)

a base, a metal layer formed on the base, and a barrier layer formed on a surface of the metal layer opposite to the base,
The metal layer includes a plurality of portions that are discontinuous at least in part,
The electromagnetic wave transmitting metallic luster article , wherein the thickness of the metal layer is greater than 20 nm and less than or equal to 100 nm . 2. The electromagnetic wave transmitting metallic luster article according to claim 1, further comprising an indium oxide-containing layer between said substrate and said metal layer. 3. The electromagnetic wave transmitting metallic luster article according to claim 2, wherein said indium oxide-containing layer is provided in a continuous state. 4. The electromagnetic wave transmitting metallic luster according to claim 2 or ₃ , wherein the indium oxide-containing layer contains any one of indium oxide ( _In2O3 ), indium tin oxide (ITO), or indium zinc oxide (IZO). Goods. The electromagnetic wave transmitting metallic luster article according to any one of claims 2 to 4, wherein the indium oxide-containing layer has a thickness of 1 nm to 1000 nm. The electromagnetic wave transmitting metallic glossy article according to any one of claims 1 to 5, further comprising a barrier layer formed between said metal layer and said substrate. The barrier layer comprises at least one selected from the group consisting of at least one oxide, nitride, carbide, oxynitride, oxycarbide, nitride carbide and oxynitride carbide of at least one metal and semimetal. 7. The electromagnetic wave transmitting metallic luster article according to any one of 6. The electromagnetic wave transmitting metallic luster article according to any one of claims 1 to 7, wherein the barrier layer contains at least one selected from the group consisting of AZO, ITO, AlO _x and SiO ₂ . 6. The ratio of the thickness of the metal layer to the thickness of the indium oxide-containing layer (thickness of the metal layer/thickness of the indium oxide-containing layer) is 0.02 to 100. 2. The electromagnetic wave transmitting metallic luster article according to item 1. The electromagnetic wave transmitting metallic luster article according to any one of claims 1 to 9, which has a sheet resistance of 100Ω/□ or more. The electromagnetic wave transmitting metallic luster article according to any one of claims 1 to 10, wherein the plurality of portions are formed like islands. 12. The metal layer according to any one of claims 1 to 11 , wherein the metal layer is aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), silver (Ag), or an alloy thereof. An electromagnetic wave transparent metallic luster article as described. The electromagnetic wave transmitting metallic glossy article according to any one of claims 1 to 12, wherein the substrate is a substrate film, a resin molding substrate, a glass substrate, or an article to which metallic luster is to be imparted. .

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