WO2019208488A1

WO2019208488A1 - Electromagnetic wave transmissive metal luster article

Info

Publication number: WO2019208488A1
Application number: PCT/JP2019/017002
Authority: WO
Inventors: 将治有本; 幸大宮本; 秀行米澤; 孝洋中井; 太一渡邉; 暁雷陳; 正義片桐
Original assignee: 日東電工株式会社
Priority date: 2018-04-23
Filing date: 2019-04-22
Publication date: 2019-10-31

Abstract

The present invention relates to an electromagnetic wave transmissive metal luster article (1) provided with: a base member (10); and a metal layer (12) formed on the base member (10). The metal layer (12) includes a plurality of portions (12a) at least partially discontinuous to each other. The metal layer (12) has a reflection haze of 15 HU or less.

Description

Electromagnetically transparent metallic luster articles

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

2. Description of the Related Art Conventionally, members having electromagnetic wave transparency and metallic luster have been suitably used for devices that transmit and receive electromagnetic waves because they have both a high-quality appearance derived from the metallic luster and electromagnetic wave transparency.
For example, there is a need for a metallic luster article that combines both luster and electromagnetic wave transmission, in which a cover member of a millimeter wave radar mounted on the front part of an automobile such as a front grill and an emblem is decorated.

Millimeter wave radar transmits millimeter wave electromagnetic waves (frequency: about 77 GHz, wavelength: about 4 mm) to the front of the car, receives reflected waves from the target, and measures and analyzes the reflected waves. The distance, target direction, and size can be measured.
The measurement result can be used for inter-vehicle measurement, automatic speed adjustment, automatic brake adjustment, and the like.
Since the front part of the automobile in which such a millimeter wave radar is arranged is a so-called automobile face and is a part that gives a large impact to the user, it is preferable to produce a high-class feeling with a metallic glossy front decoration. However, when metal is used for the front part of an automobile, transmission / reception of electromagnetic waves by the millimeter wave radar is substantially impossible or obstructed. Therefore, in order not to impair the design of the automobile without hindering the function of the millimeter wave radar, there is a need for a metallic luster article having both glitter and electromagnetic wave transparency.

This kind of metallic luster article is not only a millimeter wave radar but also various devices that require communication, for example, automobile door handles with smart keys, in-vehicle communication devices, mobile phones, electronic devices such as personal computers, etc. The application of is expected. Furthermore, in recent years, with the development of IoT technology, application in a wide range of fields such as household appliances such as refrigerators, daily life equipment, etc., which has not been conventionally performed, is expected.

Regarding a metallic luster member, Japanese Unexamined Patent Publication No. 2007-144988 (Patent Document 1) discloses a resin product including a metal coating made of chromium (Cr) or indium (In). This resin product includes a resin base material, an inorganic base film containing an inorganic compound formed on the resin base material, and glitter and discontinuity formed on the inorganic base film by physical vapor deposition. A metal film made of chromium (Cr) or indium (In) having a structure is included. As an inorganic base film, in Patent Document 1, (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 (Si ₃ N ₄ etc.); aluminum compounds such as aluminum oxide (Al ₂ O ₃ ); iron compounds such as iron oxide (Fe ₂ O ₃ ); selenium compounds such as selenium oxide (CeO); oxidation Zircon compounds such as zircon (ZrO); zinc compounds such as zinc sulfide (ZnS), etc. (b) coating films of inorganic paints such as silicon and amorphous TiO _z (and other metal compounds exemplified above) as main components An inorganic coating film is used.

On the other hand, Japanese Unexamined Patent Publication No. 2009-298006 (Patent Document 2) describes not only chromium (Cr) or indium (In) but also aluminum (Al), silver (Ag), nickel (Ni) as a metal film. An electromagnetic wave transmissive bright resin product that can be formed as is disclosed.
Japanese Patent Application Laid-Open No. 2010-5999 (Patent Document 3) discloses an electromagnetic wave transmission property in which a metal film layer is formed on a base material sheet, and cracks are generated by performing heat treatment while applying tension to the base material sheet. A method for producing a metal film decorative sheet is described.
Japanese Patent No. 4601262 (Patent Document 4) describes a cover panel in which a decorative layer having a metal coloring portion by a metal thin film layer having a discontinuous film structure is laminated on a transparent resin molded product. ing.

Japanese Unexamined Patent Publication No. 2007-144988 Japanese Unexamined Patent Publication No. 2009-298006 Japanese Unexamined Patent Publication No. 2010-5999 Japanese Patent No. 4601262

However, the metal film in the prior art has a problem that the thin film does not have sufficient glitter and the thick film is inferior in electromagnetic wave permeability, and an article having both electromagnetic wave permeability and higher glitter is desired.
The present invention was made to solve these problems in the prior art, and an object of the present invention is to provide an electromagnetic wave transmissive metallic luster article having both excellent electromagnetic wave permeability and high luster and having an excellent metal appearance. And

As a result of intensive studies to solve the above-mentioned problems, the present inventors usually have a discontinuous structure, for example, a metal layer made of other metals such as aluminum (Al) has a discontinuous structure, and It has been found that by setting the reflection haze of the metal layer to 15 HU or less, both electromagnetic wave transparency and high glitter can be achieved, and an excellent metal appearance can be obtained, and the present invention has been completed.

One aspect of the present invention includes a base and a metal layer formed on the base,
The metal layer includes a plurality of portions at least partially discontinuous with each other,
The present invention relates to an electromagnetic wave transmissive metallic luster article in which the metal layer has a reflection haze of 15 HU or less.

In one aspect of the electromagnetic wave transmissive metallic luster article of the present invention, it is preferable that an arithmetic average surface roughness Ra of at least a surface of the substrate on which the metal layer is formed is 11 nm or less.

In one aspect of the electromagnetic wave transmissive metallic luster article of the present invention, it is preferable that the maximum height roughness Rz of the surface of the metal layer is 250 nm or less.

In one aspect of the electromagnetic wave transmissive metallic luster article of the present invention, it is preferable that an indium oxide-containing layer is further provided between the base and the metal layer.

In one aspect of the electromagnetic wave transmissive 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 transmissive metallic luster article of the present invention, the indium oxide-containing layer is made of either indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), or indium zinc oxide (IZO). It is preferable to include.

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

In one aspect of the electromagnetic wave transmissive metallic luster article of the present invention, the thickness of the metal layer is preferably 15 nm to 100 nm.

In one aspect of the electromagnetic wave transmissive 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 (the thickness of the metal layer / the thickness of the indium oxide-containing layer) is 0. .02 to 100 may be used.

In one aspect of the electromagnetic wave transmissive metallic luster article of the present invention, the sheet resistance may be 100Ω / □ or more.

In one aspect of the electromagnetic wave transmissive 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 transmissive metallic luster article of the present invention, the metal layer is made of 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 transmissive metallic glossy article of the present invention, the substrate is preferably any one of a base film, a resin molded article base, a glass base, or an article to be provided with a metallic luster.

According to the present invention, it is possible to provide an electromagnetic wave transmitting metallic glossy article having both excellent electromagnetic wave permeability and high luster and having an excellent metal appearance.

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

Hereinafter, a preferred embodiment of the present invention will be described 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, the present invention is not intended to be limited thereto.

<1. Basic configuration>
FIG. 1 shows a schematic cross-sectional view of an electromagnetic wave transmissive metallic luster article (hereinafter referred to as “metallic luster article”) 1 according to an embodiment of the present invention, and FIG. 3 illustrates a discontinuous structure of a metal layer. The electron micrograph (SEM image) of the surface of a metallic luster article is shown. FIG. 5 shows a transmission electron micrograph (TEM image) of a cross-sectional view of the island-shaped metal layer 12 in one embodiment of the present invention.

The metallic luster article 1 includes a base 10 and a metal layer 12 formed on the base 10.

The metal layer 12 is formed on the substrate 10. The metal layer 12 includes a plurality of portions 12a. The plurality of portions 12a in the metal layer 12 are discontinuous from each other at least in part, in other words, at least partially separated by the gap 12b. Since they are separated by the gap 12b, the sheet resistance of the plurality of portions 12a is increased and the interaction with radio waves is reduced, so that 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.

In addition, the “discontinuous state” referred to in the present 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 increases, and the desired electromagnetic wave permeability can be obtained. That is, according to the metal layer 12 formed in a discontinuous state, sufficient glitter can be easily obtained, and electromagnetic wave permeability can be secured. A discontinuous form is not specifically limited, For example, an island-like structure, a crack structure, etc. are contained. Here, the “island-like structure” means that metal particles are independent from each other as shown in FIG. 3, and the particles are spread in a state of being slightly separated or partially in contact with each other. Means a structure.

The crack structure is a structure in which a metal thin film is divided by a crack.
The metal layer 12 having a crack structure can be formed, for example, by providing a metal thin film layer on a base film and bending and stretching it to cause a crack 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 between the base film and the metal thin film layer. .

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

The electromagnetic wave permeability of the metallic luster article 1 can be evaluated by, for example, the amount of radio wave transmission attenuation.
Note that there is a correlation between the radio wave transmission attenuation in the microwave band (5 GHz) and the radio wave transmission attenuation in the millimeter wave radar frequency band (76 to 80 GHz). A metallic luster article excellent in electromagnetic wave transmission in the wave band is also excellent in electromagnetic wave transmission in the frequency band of the millimeter wave radar.
The radio wave transmission attenuation in the microwave band (5 GHz) is preferably 10 [−dB] or less, more preferably 5 [−dB] or less, and even more preferably 2 [−dB] or less. . If it is larger than 10 [-dB], there is a problem that 90% or more of radio waves are blocked.

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

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

The 20 ° glossiness of the metallic luster article is preferably 900 or more, and more preferably 1200 or more. If it is less than 900, there is a problem that the metallic appearance cannot be obtained due to inferior luster.
The 20 ° glossiness of a metallic luster article can be measured using an appearance analyzer Rhopoint IQ-S manufactured by RHOPOINT INSTRUMENTS. The 20 ° glossiness of a metallic luster article can be measured by the method described in the examples.

<2. Base>
In the electromagnetic wave transmissive metallic glossy article according to the present embodiment, the arithmetic average surface roughness Ra of at least the surface of the substrate 10 on which the metal layer 12 is formed (hereinafter sometimes simply referred to as the arithmetic average surface roughness of the substrate) Ra is 11 nm or less. Preferably there is. By setting the arithmetic average surface roughness Ra of the substrate to 11 nm or less, the metal layer 12 of the obtained electromagnetic wave transmissive metallic luster article becomes smooth, the reflection haze is reduced, and it becomes easy to obtain an excellent metallic appearance with specularity. .
The arithmetic average surface roughness Ra of the substrate 10 can be measured by the method described in the examples. The arithmetic average surface roughness Ra of the substrate 10 is from the viewpoint of transportability. The thickness is preferably 0.1 nm or more, and preferably 11 nm or less in order to exhibit more excellent specularity. For example, the thickness is more preferably 0.1 nm to 5 nm, and particularly preferably 0.1 nm to 3 nm.
The arithmetic average surface roughness Ra of the substrate can be measured according to JIS B 0601: 1994.

The maximum height roughness Rz (hereinafter simply referred to as the maximum height roughness Rz of the substrate) of at least the surface of the substrate 10 on which the metal layer 12 is formed is preferably 200 nm or less. By setting the maximum height roughness Rz of the substrate to 200 nm or less, the metal layer 12 of the obtained electromagnetic wave transmissive metallic luster article becomes smoother, the reflection haze is reduced, and an excellent metallic appearance with specularity can be obtained more. It becomes easy.
The maximum height roughness Rz of the substrate is preferably 10 nm or more from the viewpoint of transportability, and is preferably 200 nm or less in order to exhibit more excellent specularity. For example, it is more preferably 150 nm or less, and further preferably 100 nm or less.
The maximum height roughness Rz of the substrate can be measured by the method described in Examples.

Examples of the substrate 10 include resins, glasses, and ceramics from the viewpoint of electromagnetic wave transmission.
The substrate 10 may be any of a substrate film, a resin molded substrate, a glass substrate, or an article to which a metallic luster is to be imparted.
More specifically, as the base film, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, polyamide, polyvinyl chloride, polycarbonate (PC), cycloolefin polymer (COP), polystyrene A transparent film made of a homopolymer or copolymer such as polypropylene (PP), polyethylene, polycycloolefin, polyurethane, acrylic (PMMA), or ABS can be used.

These members do not affect the glitter and electromagnetic wave transmission. However, from the viewpoint of forming the indium oxide-containing layer 11 and the metal layer 12 later, it is preferably one that can withstand high temperatures such as vapor deposition and sputtering. Therefore, among the above materials, for example, polyethylene terephthalate, polyethylene naphthalate, Acrylic, polycarbonate, cycloolefin polymer, ABS, polypropylene and polyurethane are preferred. Of these, polyethylene terephthalate, cycloolefin polymer, polycarbonate, and acrylic are preferable because of a good balance between heat resistance and cost.

The base film may be a single layer film or a laminated film, and may have a hard coat layer. In view of ease of processing, the thickness of the base film is preferably about 6 μm to 250 μm, for example. In order to strengthen the adhesion to the indium oxide-containing layer 11 and the metal layer 12, plasma treatment, easy adhesion treatment, or the like may be performed. Moreover, it is preferable that it does not contain a particle.
When the base 10 is a base film, the metal layer 12 may be provided on at least a part of the base film, may be provided only on one side of the base film, or may be provided on both sides.

The hard coat layer preferably contains a resin component.
Examples of the resin component include a curable resin, a thermoplastic resin (for example, a polyolefin resin), and preferably a curable resin.
The hard coat layer may contain particles, but from the viewpoint of adjusting the arithmetic average surface roughness Ra and the maximum height roughness Rz of the substrate, the hard coat layer preferably contains no particles.

Here, it should be noted that the base film is only an example of an object (substrate 10) on which the metal layer 12 can be formed. In addition to the base film as described above, the base 10 includes a resin molded product base, a glass base, and an article itself to which a metallic luster is to be imparted. Examples of articles that should be provided with a resin-molded base material and metallic luster include, for example, vehicle structural parts, vehicle-mounted products, electronic equipment casings, home appliance casings, structural parts, mechanical parts, and various automobiles. Parts, electronic equipment parts, furniture, household goods such as kitchenware, medical equipment, building material parts, other structural parts and exterior parts.

The metal layer 12 can be formed on all of these substrates, and may be formed on a part 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>
Moreover, the electromagnetic wave permeable metallic luster article 1 according to the embodiment may further include an indium oxide-containing layer 11 between the base 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 indirectly through a protective film or the like provided on the surface of the substrate 10. The indium oxide-containing layer 11 is preferably provided in a continuous state on the surface of the substrate 10 to be provided with a metallic luster, in other words, without a gap. By being provided in a continuous state, 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 can be improved. It is also easy to form a film.

Thus, the indium oxide-containing layer 11 is further provided between the base 10 and the metal layer 12, that is, the indium oxide-containing layer 11 is formed on the base 10, and the metal layer 12 is formed thereon. Is preferable because the metal layer 12 can be easily formed in a discontinuous state. The details of the mechanism are not always clear, but when sputtered particles formed by metal deposition or sputtering form a thin film on the substrate, the surface diffusivity of the particles on the substrate affects the shape of the thin film. It is considered that the discontinuous structure is more easily formed when the temperature of the metal layer is higher, the wettability of the metal layer to the substrate is lower, and the melting point of the material of the metal layer is lower. By providing the indium oxide-containing layer on the substrate, it is considered that the surface diffusibility of the metal particles on the surface is promoted and the metal layer can be easily grown in a discontinuous state.

As the indium oxide-containing layer 11, indium oxide (In ₂ O ₃ ) itself can be used. For example, a metal-containing material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is used. You can also However, ITO or IZO containing the second metal is more preferable in terms of high discharge stability in the sputtering process. By using these indium oxide-containing layers 11, a film in a continuous state can be formed along the surface of the substrate. In this case, a metal layer laminated on the indium oxide-containing layer is For example, it is preferable because an island-like discontinuous structure is easily obtained. Furthermore, as will be described later, in this case, not only chromium (Cr) or indium (In) but also a discontinuous structure is usually difficult to be applied to the metal layer. It becomes easy to include various metals.

The content ratio (content ratio = (SnO ₂ / (In ₂ O ₃ + SnO ₂ )) × 100) which is a mass ratio of tin oxide (SnO ₂ ) contained in ITO is not particularly limited. 0.5 wt% to 30 wt%, more preferably 3 wt% to 10 wt%. The content ratio (content ratio = (ZnO / (In ₂ O ₃ + ZnO)) × 100), which is a 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 still more preferably 20 nm or less, from the viewpoints of sheet resistance, electromagnetic wave permeability, and productivity. On the other hand, in order to facilitate the discontinuous state of the metal layer 12 to be laminated, the thickness is preferably 1 nm or more, and in order to easily facilitate the discontinuous state, it is more preferably 2 nm or more, and 5 nm or more. More preferably.

<4. Metal layer>
The metal layer 12 is formed on the substrate and includes a plurality of portions which are discontinuous with each other at least partially, and the reflection haze of the metal layer is 15 HU or less.
When the metal layer 12 is in a continuous state on the substrate, sufficient radiance can be obtained, but the radio wave transmission attenuation amount becomes very large, and therefore electromagnetic wave transmission cannot be ensured.

The details of the mechanism by which the metal layer 12 becomes discontinuous on the substrate are not necessarily clear, but are estimated to be as follows. That is, in the thin film formation process of the metal layer 12, the ease of forming the discontinuous structure is related to the surface diffusion on the substrate to which the metal layer 12 is applied, the temperature of the substrate is high, and the metal layer with respect to the substrate The lower the melting point of the material of the metal layer, the easier it is to form a discontinuous structure. Therefore, for metals other than aluminum (Al) used in particular in the following examples, for metals with relatively low melting points such as zinc (Zn), lead (Pb), copper (Cu), and silver (Ag), It is considered that a discontinuous structure can be formed by a similar method.

The reflective haze of the metal layer 12 is 15 HU or less, preferably 13 HU or less, more preferably 10 HU or less, and even more preferably 5 HU or less in order to exhibit more excellent specularity. There is no limitation in particular in the lower limit of the reflection haze of the metal layer 12, For example, what is necessary is just 0.1 HU or more.
Here, the reflection haze is an index representing the degree of haze on the surface of the high gloss sample, which is effective for evaluation of, for example, a metallic gloss finish, a high gloss finish of automobile paint, and other high gloss non-metallic surfaces. The haze of a surface state that cannot be expressed can be evaluated.

By setting the reflection haze of the metal layer to 15 HU or less, diffuse reflection is suppressed, regular reflection is performed in the visible light region, and specular reflection increases. As a result, excellent specularity can be obtained, and an electromagnetic wave-transmitting metallic luster article having an excellent metal appearance can be obtained while achieving both electromagnetic wave transmission and high glitter.
The reflection haze of the metal layer 12 can be set to the above range by adjusting the arithmetic average surface roughness Ra of the metal layer 12, the maximum height roughness Rz of the metal layer 12, and the like.
The reflection haze in the present invention is a value measured in accordance with ISO 13803 by using the appearance analyzer RHOPOINT INSTRUMENTS, and the incident point and the light receiving part of the metallic glossy article in contact with the metallic layer side of the metallic glossy article.
The reflection haze can be measured by the method described in the Examples column.

The arithmetic average surface roughness Ra of the metal layer 12 is preferably 0.1 nm or more from the viewpoint of transportability, and preferably 5 nm or less in order to exhibit more excellent specularity. For example, the thickness is more preferably 0.1 nm to 3 nm or less, and further preferably 0.1 nm to 1 nm or less.
The arithmetic average surface roughness Ra of the metal layer 12 can be measured according to JIS B 0601: 1994.

The arithmetic average surface roughness Ra of the metal layer 12 is the arithmetic average surface roughness Ra of the substrate 10, the maximum height roughness Rz of the substrate 10, the maximum height roughness Rz of the metal layer 12, and the average of the plurality of portions 12a. By adjusting the particle size or the like, the above range can be obtained, whereby diffuse reflection is suppressed, regular reflection is performed in the visible light region, and specular reflection is further increased.

Further, the maximum height roughness Rz of the metal layer 12 is preferably 0.1 nm or more, and more preferably 10 nm or more, from the viewpoint of transportability. Moreover, in order to exhibit the more excellent mirror surface property, it is preferable that it is 250 nm or less, It is more preferable that it is 200 nm or less, It is still more preferable that it is 100 nm or less.
The maximum height roughness Rz of the metal layer 12 can be measured by the method described in Examples.

Here, the average particle diameter of the plurality of portions 12a means the average value of the equivalent circle diameters of the plurality of portions 12a. The equivalent circle diameter of the portion 12a is the diameter of a perfect circle corresponding to the area of the portion 12a.
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. The distance between the portions 12a is not particularly limited, but is usually about 10 to 1000 nm.

It is desirable that the metal layer 12 has a relatively low melting point as well as sufficient glitter. 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 as the metal layer 12. For example, aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), silver (Ag) It is preferable that at least one kind of metal selected from the above and an alloy containing the metal as a main component are included. In particular, Al and alloys thereof are preferable for the reasons such as the luster and stability of the substance and the price. Moreover, when using an aluminum alloy, it is preferable that aluminum content shall be 50 mass% or more.

The thickness of the metal layer 12 is usually preferably 10 nm or more so as to exhibit sufficient glitter, and from the viewpoint of productivity, it is usually preferably 100 nm or less. For example, 15 nm to 100 nm is preferable, 15 nm to 80 nm is more preferable, 15 nm to 70 nm is further preferable, 15 nm to 60 nm is still more preferable, 15 nm to 50 nm is particularly preferable, and 15 nm to 40 nm is most preferable. In addition, the thickness of the metal layer 12 can be measured by the method as described in the column of an Example.

For the same reason, the ratio of the thickness of the metal layer to the thickness of the indium oxide-containing layer (the thickness of the metal layer / the thickness of the indium oxide-containing layer) is preferably in the range of 0.1 to 100. A range of 3 to 35 is more preferable.

The sheet resistance of the metal layer is preferably 100Ω / □ or more. In this case, the electromagnetic wave permeability is about 10 to 0.01 [-dB] at a wavelength of 5 GHz. More preferably, it is 1000Ω / □ or more.

When the indium oxide-containing layer is further provided, the sheet resistance as a laminate of the metal layer and the indium oxide-containing layer is preferably 100Ω / □ or more. In this case, the electromagnetic wave permeability is about 10 to 0.01 [-dB] at a wavelength of 5 GHz. More preferably, it is 1000Ω / □ or more. The value of the sheet resistance is greatly influenced not only by the material and thickness of the metal layer but also by the material and thickness of the indium oxide-containing layer that is the underlayer. Therefore, when providing an indium oxide content layer, it is necessary to set in consideration of a relation with an indium oxide content layer.
The metallic luster article of the present embodiment may include other layers in addition to the above-described metal layer and indium oxide-containing layer depending on the application. Other layers include an optical adjustment layer (color adjustment layer) such as a highly refractive material for adjusting the appearance such as color, and a protective layer (abrasion resistance) for improving durability such as moisture resistance and scratch resistance. Property layer), barrier layer (corrosion prevention layer), easy adhesion layer, hard coat layer, antireflection layer, light extraction layer, antiglare layer and the like.

<5. Production of metallic luster articles>
An example of the manufacturing method of the metallic luster article 1 will be described. Although not specifically described, the same method can be used when a substrate other than the substrate film is used.

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

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

In addition, when providing the indium oxide containing layer 11 between the base | substrate 10 and the metal layer 12, it is preferable to contact directly between an indium oxide containing layer 11 and the metal layer 12 without interposing another layer.

<6. Metal thin film>
The metal thin film according to the present embodiment is a metal thin film formed on a substrate, and the metal thin film has a thickness of 15 nm to 100 nm and is at least partially discontinuous from each other. The metal layer has a reflection haze of 15 HU or less.
The metal layer 12 described above can be formed to a thickness of 15 nm to 100 nm, and only this can be used as a metal thin film. For example, a metal layer 12 is formed by sputtering on an indium oxide-containing layer 11 laminated on a substrate such as a substrate film to obtain a film with a metal thin film. Separately from this, an adhesive is applied onto the substrate to produce a substrate with an adhesive layer. A film with a metal thin film is formed by laminating a film with a metal thin film and a substrate with an adhesive layer so that the metal layer 12 and the adhesive layer are in contact with each other and sufficiently adhering them. The metal layer (metal thin film) 12 present on the outermost surface of the substrate can be transferred to the outermost surface of the substrate with the adhesive layer.
The above description can be used as it is for the substrate and the metal layer.

<7. Use of metallic luster articles and metal thin films>
Since the metallic luster article and the metal thin film of the present embodiment have electromagnetic wave permeability, it is preferable to use the metallic luster article and the metal thin film for an apparatus and an article that transmit and receive electromagnetic waves, and parts thereof. For example, use for household goods such as structural parts for vehicles, on-vehicle equipment, housing for electronic equipment, housing for home appliances, structural parts, mechanical parts, various automotive parts, electronic equipment parts, furniture, kitchenware, etc. , Medical equipment, building material parts, other structural parts and exterior parts.
More specifically, in the case of 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 components, drive system / gear peripheral components, intake / exhaust system components, cooling system components, and the like.
More specifically, electronic devices and home appliances include refrigerators, washing machines, vacuum cleaners, microwave ovens, air conditioners, lighting equipment, electric water heaters, TVs, clocks, ventilation fans, projectors, speakers, and other home appliances, personal computers, mobile phones Electronic information devices such as smartphones, digital cameras, tablet PCs, portable music players, portable game machines, chargers, and batteries.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. A metallic luster article is prepared, the thickness of the substrate (substrate), the thickness of the metal layer, the reflection haze, the arithmetic average surface roughness Ra and the maximum height roughness Rz of the substrate, the arithmetic average surface roughness Ra and the maximum of the metal layer The height roughness Rz, sheet resistance, glossiness and the like were evaluated. Note that a base film was used as the substrate 10.
Sheet resistance is an evaluation relating to electromagnetic wave transmission. A larger radio wave transmission attenuation value is preferable.
Details of the evaluation method are as follows.

(1) Film thickness evaluation method First, as shown in FIG. 4, a square region 3 having a side of 5 cm is appropriately extracted from a metallic luster article, and center lines A and B of the vertical and horizontal sides of the square region 3 are respectively extracted. A total of five points “a” to “e” obtained by dividing each of these into four equal parts were selected as measurement points.
Next, a cross-sectional image (transmission electron micrograph (TEM image)) as shown in FIG. 5 is measured at each selected measurement location, and five or more metal portions 12a are included from the obtained TEM image. The viewing angle region was extracted.
The total cross-sectional area of the metal layer in the viewing angle region extracted at each of the five measurement positions divided by the lateral width of the viewing angle region is defined as the thickness of the metal layer in each viewing angle region. The average value of the thickness of the metal layer in each viewing angle region was defined as the thickness (nm) of the metal layer.

(2) Reflection haze Using an appearance analyzer RHOPOINT INSTRUMENTS Rhopoint IQ-S, the incident and light receiving parts of the apparatus are brought into contact with the metal layer side of the metallic glossy article and conform to ISO 13803. The reflection haze of the metal layer was measured. Moreover, in order to suppress back surface reflection in the case of a measurement, it measured by sticking a black light shielding tape on the base | substrate side opposite to the surface in which the metal layer is formed.

(Evaluation criteria for reflection haze)
15HU or less: ○ (good)
Over 15HU: × (defect)

(3) Arithmetic average surface roughness Ra and maximum height roughness Rz of the substrate
The base film of the substrate was fixed on a smooth base so as not to bend, and an optical surface texture measuring machine ZYGO New View 7300 manufactured by Zygo Co., Ltd. was used in accordance with JIS B 0633, and the following examples and comparisons were performed. As the smoothness before film formation of the example, the arithmetic average surface roughness Ra and the maximum height roughness Rz of the substrate were measured.
Measurement magnification: Objective lens x 10x Zoom x 1x
Measurement range: 520 μm × 700 μm

(4) Arithmetic average surface roughness Ra and maximum height roughness Rz of the metal layer
The arithmetic average surface roughness Ra and the maximum height roughness Rz of the metal layers of the metallic luster articles of Examples and Comparative Examples are the average arithmetic surface roughness Ra and the maximum height roughness Rz of the substrate as smoothness after film formation. It measured similarly.

(5) Sheet resistance The sheet resistance as a laminate of the metal layer and the indium oxide-containing layer was measured by an eddy current measurement method using a non-contact type resistance measuring device NC-80MAP manufactured by Napson, in accordance with JIS-Z2316. Depending on the value of the obtained sheet resistance, the glossiness of the metallic luster article was judged according to the following criteria.

(Evaluation criteria for sheet resistance)
Less than 1000Ω / □: x (defect)
1000Ω / □ or more: ○ (good)

(6) Glossiness at 20 ° The measurement was performed using an appearance analyzer Rhopoint IQ-S manufactured by RHOPOINT INSTRUMENTS. In addition, the measurement of 20 degree glossiness was performed with respect to the surface by the side of a metal layer. Depending on the value of the 20 ° glossiness obtained, the 20 ° glossiness of the metallic glossy article was judged according to the following criteria. Moreover, in order to suppress back surface reflection in the case of a measurement, it measured by sticking a black light shielding tape on the base | substrate side opposite to the surface in which the metal layer is formed.

(Evaluation criteria for 20 ° glossiness)
Less than 900: x (defect)
900 to less than 1200: △ (somewhat bad)
1200 or more: ○ (good)

(7) Comprehensive evaluation In the evaluation of (2), (5) and (6), those that were all good were evaluated as ◯ (good), and those that contained one defect were evaluated as x (defective).

[Example 1]
As the base film, a PET film (thickness 50 μm) on which a hard coat layer containing no particles was formed was used.
First, an ITO layer having a thickness of 5 nm was directly formed on the surface of the base film 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 rate = (SnO ₂ / (In ₂ O ₃ + SnO ₂ )) × 100) is 10 wt%.

Next, an aluminum (Al) layer having a thickness of 35 nm was formed on the ITO layer by using alternating current sputtering (AC: 40 kHz) to obtain a metallic luster article (metal thin film). The obtained aluminum layer was a discontinuous layer. The temperature of the base film when forming the Al layer was set to 130 ° C.

[Example 2]
The base film in Example 1 was changed to the particle-containing PET film shown in Table 1 to obtain a metallic luster article (metal thin film). Other conditions are the same as in the first embodiment. The obtained aluminum layer was a discontinuous layer.

[Example 3]
The base film in Example 1 was changed to the black pigment-containing PET film shown in Table 1 to obtain a metallic luster article (metal thin film). Other conditions are the same as in the first embodiment. The obtained aluminum layer was a discontinuous layer.

[Comparative Example 1]
The base film in Example 1 was changed to the PET film shown in Table 1 to obtain a metallic luster article (metal thin film). Other conditions are the same as in the first embodiment. The obtained aluminum layer was a discontinuous layer.

[Comparative Example 2]
The base film in Example 1 was changed to the PET film shown in Table 1, and a metallic luster article (metal thin film) was obtained on this surface. Other conditions are the same as in the first embodiment. The obtained aluminum layer was a discontinuous layer.

[Comparative Example 3]
The base film in Example 1 was changed to the black pigment-containing PET film shown in Table 1 to obtain a metallic luster article (metal thin film). Other conditions are the same as in the first embodiment. The obtained aluminum layer was a discontinuous layer.

Table 1 below shows the evaluation results.

As is clear from Table 1, in Example 1, the aluminum layer includes a plurality of portions 12a formed in a discontinuous state, so that the sheet resistance is 3000 or more, and good electromagnetic wave transmission results are obtained. It was. Moreover, since the reflection haze of the metal layer was 0 HU, good results were obtained for the glossiness. As a result, the overall evaluation for Example 1 was “◯”, and a metal glossy article having a good metal appearance and a metal thin film having both electromagnetic wave permeability and glossiness were obtained.
In Examples 2 and 3, as in Example 1, the sheet resistance was 3000 or more, the electromagnetic wave permeability and the reflection haze were 0 HU, and good results were obtained. As a result, the overall evaluation for Examples 2 and 3 was “◯”, and a metallic luster article with a good metallic appearance and a metal thin film having both electromagnetic wave permeability and glossiness were obtained.
On the other hand, the metallic luster articles of Comparative Examples 1 to 3 were inferior to the metallic appearance as compared with Example 1 in that the maximum height roughness Rz of the metal layer was large, the glossiness was small and the reflection haze was high.

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

The present invention is not limited to the above-described embodiments, and can be modified and embodied as appropriate without departing from the spirit of the invention.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications may be made to the above-described embodiments without departing from the scope of the present invention. And substitutions can be added.
This application is based on a Japanese patent application filed on April 23, 2018 (Japanese Patent Application No. 2018-082655) and a Japanese patent application filed on April 22, 2019 (Japanese Patent Application No. 2019-080645). The contents are incorporated by reference into this application.

The metallic luster article according to the present invention can be used for devices and articles for transmitting and receiving electromagnetic waves, and parts thereof. For example, applications for household goods such as structural parts for vehicles, vehicle-mounted products, housings for electronic devices, housings for home appliances, structural components, mechanical parts, various automotive parts, electronic device parts, furniture, kitchenware, etc. It can also be used for various applications that require both design and electromagnetic wave transmission properties, such as medical equipment, building material parts, other structural parts and exterior parts.

DESCRIPTION OF SYMBOLS 1 Metal luster article 10 Base | substrate 11 Indium oxide containing layer 12 Metal layer 12a Part 12b Gap

Claims

A substrate and a metal layer formed on the substrate;
The metal layer includes a plurality of portions at least partially discontinuous with each other,
An electromagnetic wave transmissive metallic luster article, wherein the reflective haze of the metal layer is 15 HU or less.
2. The electromagnetically transparent metallic glossy article according to claim 1, wherein an arithmetic average surface roughness Ra of at least the surface of the substrate on which the metal layer is formed is 11 nm or less.
The electromagnetic wave transmissive metallic luster article according to claim 1, wherein the maximum height roughness Rz of the surface of the metal layer is 250 nm or less.
The electromagnetically transparent metallic glossy article according to any one of claims 1 to 3, further comprising an indium oxide-containing layer between the substrate and the metal layer.
The electromagnetically transparent metal glossy article according to claim 4, wherein the indium oxide-containing layer is provided in a continuous state.
The electromagnetic wave-transmitting metallic luster according to claim 4 or 5, wherein the indium oxide-containing layer includes any one of indium oxide (In 2 O 3 ), indium tin oxide (ITO), or indium zinc oxide (IZO). Goods.
The electromagnetically transparent metallic glossy article according to any one of claims 3 to 6, wherein the indium oxide-containing layer has a thickness of 1 nm to 1000 nm.
The electromagnetically transparent metallic glossy article according to any one of claims 1 to 7, wherein the metal layer has a thickness of 15 nm to 100 nm.
The ratio of the thickness of the metal layer to the thickness of the indium oxide-containing layer (the thickness of the metal layer / the thickness of the indium oxide-containing layer) is 0.02 to 100. 2. An electromagnetic wave transparent metallic luster article according to item 1.
The electromagnetically transparent metallic glossy article according to any one of claims 1 to 8, wherein the sheet resistance is 100Ω / □ or more.
The electromagnetically transparent metal glossy article according to any one of claims 1 to 10, wherein the plurality of portions are formed in an island shape.
The metal layer is any one of aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), silver (Ag), or an alloy thereof. The electromagnetically transparent metallic luster article described.
The electromagnetic wave transmissive metallic glossy article according to any one of claims 1 to 12, wherein the substrate is any one of a base film, a resin molded article base, a glass base, or an article to be provided with metallic luster. .