阅读说明：本技术 电波透过性金属光泽构件、使用该构件的物品、及其制造方法 (Radio wave-permeable metallic luster member, article using same, and method for producing same ) 是由 陈晓雷 待永广宣 西尾创 渡边太一 中井孝洋 于 2019-01-11 设计创作，主要内容包括：本发明的目的在于,提供不仅铬(Cr)或铟(In)、例如铝(Al)等其它金属也以金属层的形式形成于由各种各样的材料制成的连续面的容易制造的电波透过性金属光泽构件、及使用该构件的物品。另外,目的在于,不仅可以将铬或铟、也可以将例如铝等其它金属以金属层的形式容易地形成于由各种各样的材料制成的连续面的、电波透过性金属光泽构件或使用了该电波透过性金属光泽构件的物品的制造方法。该构件具备具有电波透过性的基体、和直接形成于基体的连续面的铝层。铝层具有包含相互不连续的多个分离区段的不连续区域。(The present invention aims to provide a radio wave-transparent metallic luster member which is easily manufactured and In which not only chromium (Cr) or indium (In), but also other metals such as aluminum (Al) are formed as a metal layer on a continuous surface made of various materials, and an article using the member. Further, the present invention is directed to a radio wave transmissive metallic luster member in which not only chromium or indium but also other metals such as aluminum can be easily formed as a metal layer on a continuous surface made of various materials, and a method for manufacturing an article using the same. The member includes a base having radio wave permeability and an aluminum layer directly formed on a continuous surface of the base. The aluminum layer has a discontinuous region including a plurality of separated sections that are discontinuous with each other.)

1. A radio wave-transmitting metallic luster member is provided with:

a substrate having radio wave permeability, and

an aluminum layer formed directly on the continuous surface of the substrate,

the aluminum layer has a discontinuous region including a plurality of separated sections that are discontinuous from one another.

2. The radio wave transmissive metallic luster member according to claim 1, wherein,

the aluminum layer has a sheet resistance of 90 [ omega ]/□ or more.

3. A radio wave-transmitting metallic luster member is provided with:

a substrate having radio wave permeability, and

an aluminum layer formed directly on the continuous surface of the substrate,

the sheet resistance of the radio wave-transmitting metallic luster member is 90 Ω/□ or more.

4. The electric wave transmissive metallic luster member according to any one of claims 1 to 3, wherein,

the continuous surface is formed of a dielectric resin material or a glass material.

5. The radio wave transmissive metallic luster member according to claim 4, wherein,

the dielectric resin material includes any of polyester, polyolefin, acrylic polymer, and polycarbonate.

6. The electric wave transmissive metallic luster member according to any one of claims 1 to 3, wherein,

the continuous surface is formed using an indium oxide-containing material.

7. The electric wave transmissive metallic luster member according to any one of claims 1 to 6, wherein,

the substrate is a film, a resin molded article, a glass article, or an article itself to be imparted with metallic luster.

8. The electric wave transmissive metallic luster member according to any one of claims 1 to 7, wherein,

the maximum thickness of the aluminum layer is 15-80 nm.

9. The electric wave transmissive metallic luster member according to any one of claims 1 to 8, wherein,

the aluminum layer has a radio wave transmission attenuation of 10dB or less.

10. The electric wave transmissive metallic luster member according to any one of claims 1 to 9, wherein,

the aluminum layer is any of aluminum (Al) or an alloy of aluminum (Al).

11. The radio wave transmissive metallic luster member according to claim 10, wherein,

the aluminum (Al) alloy has an aluminum content of 50% or more in all metal components.

12. The electric wave transmissive metallic luster member according to any one of claims 1 to 11, wherein,

the aluminum is provided on an inner surface of a transparent frame formed by a continuous surface of the base.

13. An article using the radio wave-permeable metallic luster member according to any one of claims 1 to 12.

14. The article of claim 13, wherein,

the article is a communication device.

15. A method for manufacturing an electric wave transmissive metallic luster member or an article using the same, comprising:

a step of directly forming an aluminum layer having a discontinuous region including a plurality of separated sections which are discontinuous with each other on a substrate having radio wave permeability by using AC sputtering.

16. A method for manufacturing an electric wave transmissive metallic luster member or an article using the same, comprising:

and a step of directly forming an aluminum layer on a substrate having radio wave permeability by AC sputtering so that the sheet resistance becomes 90 Ω/□ or more.

17. The radio wave-permeable metallic luster member or the method for manufacturing an article using the same according to claim 15 or 16, wherein,

the aluminum layer is directly formed on the continuous surface of the substrate.

18. The radio wave-permeable metallic luster member or the method for manufacturing an article using the same according to claim 17, wherein,

the continuous surface is formed of a dielectric resin material or a glass material.

19. The radio wave-permeable metallic luster member or the method for manufacturing an article using the same according to claim 17, wherein,

the continuous surface is formed using an indium oxide-containing material.

20. The manufacturing method according to any one of claims 15 to 19,

the AC sputtering is performed under a pressure of 1.5Pa or more.

21. The manufacturing method according to any one of claims 15 to 20,

the temperature of the substrate when AC sputtering is performed is 20 ℃ or higher.

Technical Field

The present invention relates to a radio wave-permeable metallic luster member, an article using the same, and a method for producing the same.

Background

For example, in order to decorate a cover member of a millimeter wave radar mounted on a front portion of an automobile such as a front grille and a emblem, a metallic luster member having both a glittering property and a radio wave permeability is demanded.

The millimeter wave radar transmits and receives electromagnetic waves in a millimeter wave band (having a frequency of about 77GHz and a wavelength of about 4mm) to the front of the automobile and receives reflected waves from a target, and by measuring and analyzing the reflected waves, it is possible to measure the distance to the target and the direction and size of the target. The measurement results can be used for inter-vehicle distance measurement, automatic speed adjustment, automatic brake adjustment and the like. The front part of the automobile on which such a millimeter wave radar is disposed is a part of the automobile, which gives a user a deep impression, and therefore, it is preferable to present a high-grade feeling or the like with a front trim having a metallic luster feeling. However, when metal is used for the front part of the automobile, transmission and reception of electromagnetic waves by the millimeter wave radar are practically impossible or hindered. Therefore, in order to prevent the millimeter wave radar from interfering with the operation and to prevent the appearance of the automobile from being impaired, a metallic luster member having both a glittering property and a radio wave transmitting property is required.

Such a metallic luster member is expected to be applied not only to millimeter-wave radars but also to various devices requiring communication, for example, electronic devices such as automobile door handles, in-vehicle communication devices, mobile phones, and personal computers provided with smart locks. In recent years, with the development of the IoT technology, it is expected to be applied to a wide range of fields such as home electric appliances and living equipment, such as refrigerators, which do not perform communication at present.

As for the metallic luster member, japanese patent application laid-open No. 2007-144988 (patent document 1) discloses a resin product including a metal coating film made of chromium (Cr) or indium (In). The resin product comprises: the metal coating film is characterized by comprising a resin base material, an inorganic base film containing an inorganic compound and formed on the resin base material, and a metal coating film which is formed on the inorganic base film by a physical vapor deposition method and is provided with brightness and a discontinuous structure and is composed of chromium (Cr) or indium (In). As the inorganic base film, patent document 1 uses: (a) films of metal compounds, e.g. titanium oxide (TiO )₂、Ti₃O₅Etc.) titanium compounds, silicon oxide (SiO )₂Etc.), silicon nitride (Si)₃N₄Etc.), silicon compounds, aluminum oxide (Al)₂O₃) Aluminum compound, iron oxide (Fe)₂O₃) Iron compounds such as selenium oxide (CeO), zirconium compounds such as zirconium oxide (ZrO), zinc compounds such as zinc sulfide (ZnS), and the like; (b) coating films of inorganic coatings, e.g. with silicon, amorphous TiO₂And the like (and the metal compounds exemplified above) as a main component. However, this resin product uses only chromium (Cr) or indium (In) as the metal coating, and cannot use aluminum (Al), for example, which is relatively more excellent In price and brightness, as the metal coating.

On the other hand, japanese laid-open patent publication No. 2009-298006 (patent document 2) discloses an electromagnetic wave transmissive bright resin product which can be formed of not only chromium (Cr) or indium (In) but also aluminum (Al), silver (Ag), and nickel (Ni) as a metal film. These metal films are formed by providing a base film having a discontinuous structure, but in order to form the base film as a discontinuous layer, the inclination angle of the sputtering base material must be set to 0 ° or 70 °, which causes a problem of manufacturing trouble due to such a limitation. Further, according to patent document 2, for example, zinc (Zn), lead (Pb), copper (Cu), or an alloy thereof cannot be formed as a metal film.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide a radio wave transmissive metallic luster member which is easily manufactured and which is formed as a metal layer on a continuous surface made of various materials, not only of chromium (Cr) or indium (In), but also of other metals such as aluminum (Al), and an article using the same. Another object of the present invention is to provide a radio wave-transparent metallic luster member In which not only chromium (Cr) or indium (In) but also other metals such as aluminum (Al) can be formed as a metal layer on a continuous surface made of various materials, and a method for producing an article using the same.

Means for solving the problems

The present inventors have conducted intensive studies in order to solve the above problems, and as a result, have found that other metals, such as aluminum (Al), which are generally difficult to form a discontinuous structure, can be made to exhibit a discontinuous structure on a continuous surface made of various materials by using AC (alternating current) sputtering, thereby completing the present invention.

In order to solve the above problems, a radio wave-permeable metallic luster member according to one embodiment of the present invention includes: the aluminum-based radio wave-transmitting substrate comprises a radio wave-transmitting substrate and an aluminum layer directly formed on a continuous surface of the substrate, wherein the aluminum layer comprises a discontinuous region comprising a plurality of discontinuous separation sections.

According to the radio wave-permeable metallic luster member of this aspect, it is possible to provide a radio wave-permeable metallic luster member that is easy to manufacture, In which not only chromium (Cr) or indium (In), but also aluminum (Al), for example, is formed as a metal layer on a continuous surface made of various materials.

In the radio wave transmitting metallic luster member according to the above aspect, the aluminum layer preferably has a sheet resistance of 90 Ω/□ or more.

In order to solve the above problem, another aspect of the present invention provides a radio wave-permeable metallic luster member including: the aluminum layer is directly formed on the continuous surface of the substrate, wherein the sheet resistance of the radio wave permeable metallic luster member is 90 omega/□ or more.

According to the radio wave-permeable metallic luster member of this aspect, it is possible to provide a radio wave-permeable metallic luster member that is easy to manufacture, In which not only chromium (Cr) or indium (In), but also aluminum (Al), for example, is formed as a metal layer on a continuous surface made of various materials.

In the radio wave transmissive metallic luster member according to the above aspect, the continuous surface may be formed of a dielectric resin material or a glass material. The dielectric resin material may include any of polyester, polyolefin, acrylic polymer, and polycarbonate.

In the radio wave-transmitting metallic luster member according to the above aspect, the continuous surface may be formed using an indium oxide-containing material.

In the radio wave transmissive metallic luster member of the above aspect, the substrate may be a film, a resin molded article, a glass product, or an article itself to be provided with a metallic luster.

In the radio wave transmitting metallic luster member according to the above aspect, the aluminum layer preferably has a maximum thickness of 15 to 80 nm.

In the radio wave-transmitting metallic luster member according to the above aspect, the aluminum layer preferably has a radio wave transmission attenuation of 10dB or less.

In the radio wave transmitting metallic luster member according to the above aspect, the aluminum layer may be any of aluminum (Al) and an alloy of aluminum (Al). Here, the aluminum (Al) content ratio in all the metal components in the aluminum (Al) alloy is preferably 50% or more.

In the radio wave-transmitting metallic luster member according to the above aspect, the aluminum may be provided on an inner surface of a transparent frame formed by a continuous surface of the base body.

A radio wave-permeable metallic luster member according to an aspect of the present invention or a method for manufacturing an article using the same includes: and a step of directly forming an aluminum layer having a discontinuous region including a plurality of discrete segments which are discontinuous with each other on a substrate having radio wave permeability by using AC sputtering.

Another aspect of the present invention provides a method for manufacturing a radio wave-transmissive metallic luster member or an article using the same, including: and a step of directly forming an aluminum layer on a substrate having radio wave permeability by AC sputtering so that the sheet resistance becomes 90 Ω/□ or more.

According to the radio wave-transmissive metallic luster member or the method for manufacturing an article using the same of these aspects, not only chromium (Cr) or indium (In), but also other metals such as aluminum (Al) can be easily formed as a metal layer on a continuous surface made of various materials.

In the method for producing a radio wave-transmitting metallic luster member according to the above aspect, the aluminum layer may be formed directly on the continuous surface of the base. Here, the continuous surface may be formed of a dielectric resin material or a glass material, or may be formed of an indium oxide-containing material.

In the method for producing a radio wave-transparent metallic luster member according to the above aspect, the AC sputtering is preferably performed at a pressure of 1.5Pa or more.

In the method for producing a radio wave-transparent metallic luster member according to the above aspect, the temperature of the base body when the AC sputtering is performed is preferably 20 ℃.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there are provided a radio wave-transparent metallic luster member that can be easily manufactured, In which the surface on which the metal layer is to be formed may be a continuous surface, and not only chromium (Cr) or indium (In) but also other metals such as aluminum (Al) may be used as the metal layer, an article using the member, and a manufacturing method thereof.

Drawings

Fig. 1(a) and (b) are schematic cross-sectional views of a radio wave-transmitting metallic luster member according to an embodiment of the invention.

Fig. 2(a) and (b) show electron micrographs of the surface of the radio wave transmissive metallic luster member according to the embodiment of the invention.

Fig. 3 is a diagram illustrating a method for measuring the thickness of the metal layer in the examples and comparative examples.

Fig. 4 is an image of a cross section in a partial region of fig. 2 (b).

Description of the symbols

1 metallic luster Member

3 metallic film

10 base material film

10a continuous surface

11 base layer (with indium oxide layer)

11a continuous surface

12 metal layer

Detailed Description

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. For convenience of explanation, only the preferred embodiments of the present invention are shown, but the present invention is obviously not limited thereto.

< 1. basic constitution >

Fig. 1(a) and (b) are schematic cross-sectional views of radio wave-transmissive metallic luster members (hereinafter, referred to as "metallic luster members") 1 and 1A according to one embodiment of the present invention, respectively. Including these and other figures, like or corresponding elements are designated with the same reference numerals.

Both the metallic luster members 1, 1A include: a substrate 10 having radio wave permeability, and a metal layer 12 directly formed on the continuous surfaces 10a, 11a of the substrate 10. The difference between the metallic luster member 1 and the metallic luster member 1A is that, unlike the metallic luster member 1, the base layer 11 is provided on the base 10 in the metallic luster member 1A. The base layer 11 is provided to reduce wettability between the metal layer 12 and the substrate 10, and the provision of such a base layer 11 makes the metal layer 12 easily discontinuous. Since the base layer 11 is provided, unlike the continuous surface 10a in the metallic luster member 1, the continuous surface 11A in the metallic luster member 1A cannot be formed by the surface 10a of the base 10 itself, and is precisely formed by the surface 11A of the base layer 11 provided on the base 10. Although the base layer 11 is thin in film form and therefore may have discontinuous portions 11b, even if such discontinuous portions 11b are formed, the base layer 11 is thin and has a thickness of about 10nm or less, and therefore the metal layer 12 is not discontinuous by these discontinuous portions 11 b. In other words, it can be understood that: even if the base layer 11 has the discontinuous portion 11b, the base 10 substantially forms the continuous surface 11a in relation to the metal layer 12 even though the base layer 11 is included. Thus, the term "continuous surface of the substrate" in the present specification means a continuous surface 11a including the base layer in addition to the continuous surface 10a of the substrate itself. As described above, in any of the metallic luster members 1 and 1A, since the metal layer 12 is directly formed on the continuous surfaces 10a and 11A of the base 10, the smoothness and corrosion resistance thereof are greatly improved, and the metal layer 12 is easily arranged in the surface without unevenness.

< 2. matrix >

< 2-1. article constituting substrate >

The substrate 10 needs to have radio wave permeability, and may be, for example: a film, a resin molded article, a glass article, and an article itself to be imparted with metallic luster.

When the substrate 10 is a film, the film is formed of a material such as a homopolymer or a copolymer of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, polyamide, polyimide, nylon, polyvinyl chloride, Polycarbonate (PC), cycloolefin polymer (COP), polystyrene, polypropylene (PP), Polyethylene (PE), polycycloolefin, polyurethane, acrylic (PMMA), ABS, or the like. These materials do not affect the brightness and the radio wave permeability. These films are preferably transparent. Further, from the viewpoint of forming the metal layer 12 later, a material that can withstand high temperatures at the time of sputtering is preferable, and among the above materials, for example, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, a cycloolefin polymer, polypropylene, polyurethane, acrylic, and ABS are preferable. Among them, polyethylene terephthalate, cycloolefin polymer, polycarbonate, and acrylic are preferable because of a good balance between heat resistance and cost. The substrate 10 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 and the like.

When the substrate 10 is a glass product, for example, soda lime glass, alkali-free glass, chemically strengthened glass, or the like can be used, but the substrate is not limited thereto.

When the substrate 10 is a resin molded product, for example, the following may be used: ABS, PC, PMMA, PP, PE, polyphthalamide (PPA), Polyoxymethylene (POM), polybutylene terephthalate (PBT), but not limited thereto.

As the substrate 10, an article itself to be imparted with metallic luster may be formed, for example, by using the substrate 10, a car emblem of an automobile, a car door handle provided with a smart lock, a housing of a communication device such as a mobile phone or a personal computer, or a housing of a refrigerator. When a housing of a communication device or the like is transparent, the metal layer 12 may be provided on an outer surface or an inner surface of the housing. However, the article to be provided with metallic luster preferably satisfies the same material and conditions as those in the case where the substrate is a film, a glass product, or a resin molded product.

< 2-2. continuous surface of substrate >

The continuous surface 10a of the substrate 10 may be formed of, for example, a dielectric resin material or a glass material, and the continuous surface 11a of the substrate 10 may be formed of, for example, any one of a dielectric resin material, a glass material, and an indium oxide-containing material. The entire regions of the continuous surfaces 10a, 11a are not necessarily formed of any of these materials, and the partial regions and other regions may be formed of different materials, respectively. In addition, only part of the continuous surfaces 10a and 11a may be formed of these materials.

As the dielectric resin material, for example: polyesters, polyolefins, acrylic polymers, polycarbonates. The dielectric resin material also contains Al₂O₃、SiO₂、Nb₂O₃、TiO₂And dielectric metal oxide materials such as AlN and SiN, and dielectric metal nitride materials such as AlN and SiN, on a resin molded article such as a film. For example, as shown in fig. 1(a), when the substrate 10 is a resin molded article, the continuous surface 10a of the substrate 10 is formed of these materials, whereby the continuous surface 10a can be formed of the article itself to be imparted with metallic luster. In other words, the metal layer 12 may be directly formed on the substrate 10.

As the glass material, for example, alkali-free glass can be used. For example, as shown in fig. 1(a), when the substrate 10 is a glass product, the continuous surface 10a can be formed by the article itself to be imparted with metallic luster by forming the continuous surface 10a of the substrate 10 from these materials. In other words, the metal layer 12 may be directly formed on the substrate 10.

As the indium oxide-containing material, for example, indium oxide (In) can be used₂O₃) As such, a metal-containing substance such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO) may be used. However, ITO and IZO containing the second metal are more preferable in terms of high discharge stability in the sputtering step. Tin (Sn) In ITO to In₂O₃The content of (b) is not particularly limited, but is, for example, 2.5 to 30 wt%, more preferably 3 to 10 wt%, and zinc oxide (ZnO) In IZO is In relation to In₂O₃The content of (B) is, for example, 2 to 20 wt%. As shown in fig. 1(b), these indium oxide-containing materials are provided as the underlayer 11 in order to reduce the wettability between the metal layer 12 and the substrate 10, and therefore can substantially form the continuous surface 11a of the substrate 10. However, when the continuous surface 11a is formed of a dielectric resin material, the continuous surface of the base 10 cannot be formed by the article itself to be imparted with metallic luster11 a. The indium oxide-containing layer 11 as the underlayer 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 thickness of the indium oxide-containing layer 11 is usually 100nm or less, more preferably 50nm or less, and still more preferably 20nm or less from the viewpoint of sheet resistance, radio wave permeability, and productivity. On the other hand, the metal layer 12 to be laminated is preferably 1nm or more in order to be discontinuous, and more preferably 2nm or more, and even more preferably 5nm or more in order to reliably form the discontinuous state.

< 3. Metal layer >

< 3-1. Structure of Metal layer

The metal layer 12 is provided on the continuous surfaces 10a and 11a of the substrate 10 by AC sputtering such as MF-AC sputtering using an intermediate frequency region of 40kHz, for example. By imparting the metal layer 12 by AC sputtering, the metal layer 12 can be formed in a mutually discontinuous state in at least partial regions of the continuous surfaces 10a, 11a, further in other words, a discontinuous region including a plurality of separated sections 12a separated by gaps 12 b. Since the separation section is separated by the gap 12b, the sheet resistance in the separation section 12a increases and the radio wave transmission attenuation decreases, and as a result, the interaction with the electromagnetic wave decreases, and the electromagnetic wave can be transmitted. These separate sections 12a are each aggregates of sputtered particles formed by AC sputtering of metal. The detailed mechanism of the discontinuity of the metal layer 12 on the continuous surfaces 10a and 11a is not clear, but is assumed to be as follows. That is, in the thin film forming process of the metal layer 12, the ease of formation of the discontinuous structure is related to surface diffusion on the member to be provided with the metal layer 12 (the member forming the continuous surfaces 10a and 11a in the present invention), and when the temperature of the member to be provided is high, the wettability of the metal layer with respect to the member to be provided is small, and the melting point of the material of the metal layer is low, the discontinuous structure is easily formed. Therefore, in the following examples, the discontinuous structure can be formed by the same method for metals other than aluminum (Al), that is, metals having relatively low melting points such as zinc (Zn), lead (Pb), copper (Cu), and silver (Ag). In the present specification, the term "discontinuous state" refers to a state in which the gaps 12b are separated from each other and, as a result, are electrically insulated from each other. By the electrical insulation, the sheet resistance becomes large, and desired radio wave permeability is obtained. The discontinuous form is not particularly limited, and includes, for example, islands, cracks, and the like. The "island-like" refers to a structure in which the particles as the sputtering particle assembly are independent of each other and the particles are laid in a state of being slightly separated from each other or partially in contact with each other, as shown in fig. 1 (b).

< 3-2. Material of Metal layer >

It is obvious that the metal layer 12 is desired to exhibit sufficient brightness and to have a low melting point. The metal layer 12 is formed by thin film growth using sputtering. From this point of view, as the metal layer 12, a metal having a melting point of about 1000 ℃ or less is suitable, and for example, any kind of metal selected from at least one of aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), and silver (Ag), and an alloy containing the metal as a main component is preferably contained. In particular, aluminum and its alloys are preferable in view of the brightness, stability, price, and the like of the material. The aluminum content of the aluminum alloy in the entire metal components in the alloy is preferably 50% or more, more preferably 60% or more, and still more preferably 75% or more.

< 3-2-1. case where the continuous surface is formed of the substrate itself >

As shown in fig. 1(a), when the continuous surface is formed by the surface 10a of the substrate 10 itself and the metal layer 12 is directly formed on the continuous surface 10a, the thickness of the metal layer 12 is preferably 15nm or more in order to exhibit sufficient brightness, and is preferably 80nm or less in view of sheet resistance and radio wave transmittance. For example, it is preferably 20nm to 75nm, more preferably 25nm to 70 nm. This thickness is also suitable for forming a uniform film with good productivity, and the appearance of a resin molded article as a final product is also good.

In order to exhibit sufficient radio wave permeability, the sheet resistance of the metal layer 12 is preferably 100 to 100000 Ω/□. In this case, the radio wave transmission attenuation is about 10 to 0.01 < -dB > at a wavelength of 1 GHz. Further preferably 1000 to 50000 omega/□.

< 3-2-2. case where the continuous surface is formed of a substrate layer

As shown in fig. 1(b), when the continuous surface 11a is formed of the surface of the underlying layer 11 and the metal layer 12 is directly formed on the continuous surface 11a of the substrate 10, the thickness of the metal layer 12 is preferably 20nm or more in order to exhibit sufficient brightness, and is preferably 100nm or less in view of sheet resistance and radio wave transmittance. For example, it is preferably 20nm to 100nm, more preferably 30nm to 70 nm. The preferable value is larger than the above-mentioned value < 3-2-1 > because the wettability between the metal layer 12 and the substrate 10 is reduced by providing the base layer 11, and the metal layer 12 is likely to form a discontinuous layer, thereby making it possible to realize a thick film. Since the base layer 11 is a film-like layer, it does not substantially affect the brightness, sheet resistance, and the like. This thickness is also suitable for forming a uniform film with good productivity, and the appearance of a resin molded article as a final product is also good.

For the same reason, for example, when the underlayer 11 is an indium oxide-containing layer, 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 preferably in the range of 0.1 to 100, and more preferably in the range of 0.3 to 35.

Further, the sheet resistance of the laminate of the metal layer 12 and the base layer 11 is preferably 100 to 100000 Ω/□. In this case, the radio wave transmittance is about 10 to 0.01 < -dB > at a wavelength of 1 GHz. More preferably 1000 to 50000 omega/□.

< 4. method for producing metallic luster member

An example of the method for producing the metallic lustrous member 1, 1A will be explained.

< 4-1. case where the continuous surface is formed of the substrate itself >

As shown in fig. 1(a), when the continuous surface 10a is formed of the surface of the substrate 10 itself and the metal layer 12 is directly formed on the continuous surface 10a, the metal layer 12 is directly formed on the continuous surface 10a by AC sputtering without going through the step of forming the continuous surface 10 a.

< 4-2. case where the continuous surface is formed of a substrate layer >

As shown in fig. 1(b), when the continuous surface 11a is formed of the base layer 11 and the metal layer 12 is directly formed on the continuous surface 11a, at least 2 steps are required.

(1) Process for Forming indium oxide-containing layer

An indium oxide-containing layer 11 is formed on the base 10. The indium oxide containing layer 11 can be formed by vacuum evaporation, sputtering, ion plating, or the like. However, sputtering is preferable because the thickness can be strictly controlled even in a large area.

(2) Process for laminating Metal layers

Next, the metal layer 12 is directly laminated on the continuous surface 11a formed of the indium oxide containing layer 11. The lamination of the metal layer 12 utilizes AC sputtering. It is preferable that the indium oxide-containing layer 11 and the metal layer 12 are in direct contact without interposing another layer therebetween, but another layer may be interposed as long as the surface diffusion mechanism of the metal layer 12 on the indium oxide-containing layer 11 described above is ensured.

< 5. examples and comparative examples >

< 5-1. case where the continuous surface is formed of the substrate itself >

In examples and comparative examples, various samples were prepared using films as the substrate 10. The prepared samples were evaluated for sheet resistance, radio wave transmission attenuation, and glossiness. The sheet resistance and the radio wave transmission attenuation are evaluations related to the radio wave transmission, and the glossiness is an evaluation related to the glitter. Preferably, the larger the values of the glossiness and the sheet resistance, the better the value of the radio wave transmission attenuation.

Details of the evaluation method are as follows.

(1) Sheet resistance

The sheet resistance of the metal layer was measured by an eddy current measurement method in accordance with JIS-Z2316 using a non-contact resistance measuring device NC-80MAP manufactured by Napson K.K.

The sheet resistance is required to be 90 Ω/□ or more, preferably 200 Ω/□ or more, more preferably 250 Ω/□ or more, and further preferably 600 Ω/□ or more. When the ratio is less than 90 Ω/□, there is a problem that sufficient radio wave transmittance cannot be obtained.

(2) Attenuation of radio wave transmission

The radio wave transmission attenuation at 1GHz was evaluated by using a KEC method measurement and evaluation tool and a spectrum analyzer CXA signalAnalyzer NA9000A manufactured by Agilent K.K. Since the electromagnetic wave permeability in the frequency band (76 to 80GHz) of the millimeter wave radar and the electromagnetic wave permeability in the microwave frequency band (1GHz) have a correlation and show relatively similar values, the electromagnetic wave permeability in the microwave frequency band (1GHz) (that is, the microwave electric field transmission attenuation) is used as an index in this evaluation.

The microwave electric field transmission attenuation is required to be 10 < -dB or less, preferably 5 < -dB or less, and more preferably 2 < -dB or less. If it is 10-dB or more, there is a problem that 90% or more of the electric wave is blocked.

(3) Degree of gloss

The 20 ℃ specular gloss of the metal layer was measured according to JIS-Z8741 using a portable gloss meter PG-II M manufactured by Nippon Denshoku industries Co., Ltd. The glossiness was correlated with the visible light reflectance used in < 5-2 > below, and substantially the same evaluation was possible, but the glossiness excellent in quantitative expression of metallic gloss was used here.

In order to have sufficient glossiness, the glossiness needs to be 500 or more, preferably 750 or more, and more preferably 1000 or more. When the gloss is less than 500, the gloss is lowered, and the appearance is not excellent.

(4) Thickness of the metal layer

In the examples and comparative examples, the average value of the thicknesses of the separated segments 12a is set as the thickness of the metal layer, taking into account the variation in the metal layer, more specifically, the variation in the thicknesses between the separated segments 12a shown in fig. 1. Hereinafter, this average value is referred to as "maximum thickness" for convenience. The thickness of each separation section 12a is set to be the thickness at the thickest point in the vertical direction from the base (corresponding to the continuous surfaces 10a and 11a in fig. 1).

Fig. 2 shows an example of an electron micrograph (SEM image) of the surface of the radio wave transmissive metallic luster member. The image size in the SEM image of FIG. 2(a) was 1.16. mu. m.times.0.85. mu.m, and the image size in the SEM image of FIG. 2(b) was 1.16. mu. m.times.0.85. mu.m. When the maximum thickness is calculated, first, a square area 3 having one side of 5cm as shown in fig. 3 is appropriately selected from the metal layer appearing on the surface of the radio wave-transparent metallic luster member shown in fig. 2, the center lines A, B of the vertical and horizontal sides of the square area 3 are equally divided into 4 parts, and the obtained points "a" to "e" at 5 positions in total are selected as the measurement positions.

Next, a viewing angle region including about 5 separation sections 12a is extracted from the cross-sectional image (transmission electron micrograph (TEM image)) shown in fig. 4 of each selected measurement position.

The thicknesses of about 5 separated segments 12a, that is, about 25 separated segments 12a (5 × 5 positions) in each of the measurement positions of the total 5 positions were determined, and the average value of the thicknesses was defined as the "maximum thickness".

The evaluation results are shown in table 1 below.

[ Table 1]

[ example 1]

As a film (hereinafter referred to as "base film") used as the substrate 10, a PET film (thickness 125 μm) manufactured by mitsubishi resin corporation was prepared. In addition, the metal layer uses an aluminum layer. An aluminum (Al) layer having a maximum thickness of 20nm was directly formed on the continuous surface of the base film by AC sputtering (MF-AC sputtering using a middle frequency region of 40 kHz) to obtain a metallic luster member (hereinafter referred to as "metallic film"). The temperature of the substrate film when the Al layer was formed was set to 130 ℃, and the pressure of argon (Ar) gas in the chamber in which the substrate film was housed was set to 2 Pa.

In the configuration of example 1, the continuous surface of the base film exhibited high smoothness and corrosion resistance, while the continuous surface included a plurality of separated sections 12a in which the aluminum layer was formed in a discontinuous state, and therefore, the sheet resistance thereof was a large value, and the radio wave transmission attenuation exhibited relatively good results. For convenience, in table 1, as a result of "evaluation" of the radio wave transmission attenuation amount, the case where the radio wave transmission attenuation amount is less than 2-dB is represented by "excellent", the case where the radio wave transmission attenuation amount is 2-dB or more and less than 5-dB is represented by "o", the case where the radio wave transmission attenuation amount is 5-dB or more and less than 10-dB is represented by "Δ", and the case where the radio wave transmission attenuation amount is 10-dB or more is represented by "x".

In addition, in the configuration of example 1, as for the glitter, a practical result that can be sufficiently endured was also obtained. For convenience, in table 1, as a result of "evaluation" of the glossiness, the case where the glossiness is 1000 or more is indicated by "excellent", the case where the glossiness is 750 or more and less than 1000 is indicated by "o", the case where the glossiness is 500 or more and less than 750 is indicated by "Δ", and the case where the glossiness is less than 500 is indicated by "x". Further, as "comprehensive evaluation" of radio wave permeability and luminosity, if "x" is given in any evaluation, it is assumed that "x" is given, and in addition, it is assumed that "o". As a result, in example 1, a metallic glossy member or a metallic film having both good radio wave transmittance and good glitter was obtained, which was evaluated as "o".

[ example 2] to [ example 6]

In examples 2 to 6, the maximum thickness of the aluminum layer formed on the continuous surface of the base film was increased stepwise so as to be larger than that of example 1. In examples 4 to 6, the pressure of argon gas was set to a value higher than that in example 1. Other conditions were the same as in example 1.

The sheet resistance was a large value exceeding 3k Ω/□ in examples 2 to 4 as in example 1, but in examples 5 and 6, although it was not as large as in examples 2 to 4, a practically sufficient value was obtained. In examples 5 and 6, the reason why the sheet resistance became lower than that in example 1 was that the deposition amount of aluminum increased and the discontinuous region decreased. The radio wave transmission attenuation values in examples 2 to 6 were all equal to or higher than those in example 1. On the other hand, it is needless to say that the results of examples 2 to 6 are higher than those of example 1.

Fig. 2(a) shows an SEM image of the surface of the metallic luster member (metal film) obtained in example 6.

[ example 7] to [ example 11]

In each of examples 7 to 11, the maximum thickness of the aluminum layer formed on the continuous surface was set to be the same as that in example 2, and the sputtering conditions other than the temperature of the base material film were made uniform. The temperature of the substrate film was set to be lower than that of example 2. In examples 7 to 11, the material of the base film was changed. In example 7, polyethylene terephthalate (PET film made by Mitsubishi chemical corporation, thickness 125 μm) was used, In example 8, acrylic (PMMA made by Mitsubishi chemical corporation, thickness 125 μm) was used, In example 9, polycarbonate (PC made by Sumitomo chemical corporation, thickness 125 μm) was used, In example 10, alkali-free glass (thickness 400 μm made by Corning corporation) was used, and In example 11, ITO/PET (tin (Sn) In ITO was used as In)₂O₃The content of (B) was 10 wt%, and the film thickness was 5 nm). Thus, in examples 7 to 11, although the material of the base film was changed, in examples 7 to 11, the radio wave permeability and the brightness were at least equal to or higher than those of examples 1 to 6, respectively. From the results of examples 7 to 11, it was found that a metallic luster member or a metallic film having both radio wave transparency and luster can be obtained regardless of the material of the base film.

Comparative examples 1 to 2

In contrast to comparative example 1, in which the maximum thickness of the aluminum layer formed on the continuous surface of the base film was set to be smaller than those of examples 1 to 11, in comparative example 2, the maximum thickness was set to be larger than those of examples 1 to 11. The pressure of the argon gas was set to a value lower than those of examples 1 to 11. The other conditions were the same as in examples 1 to 6.

In comparative example 1, the aluminum layer was thin, and therefore, good results were obtained with respect to sheet resistance and radio wave transmission attenuation, but insufficient results were obtained with respect to glossiness. On the other hand, in comparative example 2, the aluminum layer was thick, and therefore, sufficient results were obtained with respect to the glossiness, but the values of the sheet resistance and the radio wave transmission attenuation were deteriorated, and the practical use could not be tolerated.

Comparative example 3

The conditions other than the method of sputtering and the pressure of argon gas were the same as those in example 2. The pressure of argon gas was set to a value lower than those of examples 1 to 11 in the same manner as in comparative examples 1 and 2. As a method of sputtering, DC sputtering is used here. The DC sputtering apparatus used was the same as that used in example 1, and only the power supply was changed to a DC system. In this case, both the radio wave permeability and the brightness are insufficient.

Comparative example 4

As a film forming method, vacuum deposition is used here. More specifically, a substrate was placed in a chamber and evacuated to 10 degrees centigrade using a high vacuum evaporation apparatus EX-550 manufactured by ULVAC^-4After Pa, aluminum was deposited at a rate of 1nm/sec for 30nm by resistance heating. In this case, both the radio wave permeability and the brightness are insufficient.

< 5-2. case where the continuous surface is formed of a substrate layer >

In examples and comparative examples, various samples were prepared using films as the substrate 10. The prepared samples were evaluated for sheet resistance, radio wave transmission attenuation, and visible light reflectance. Here, the sheet resistance and the radio wave transmission attenuation are evaluations related to the radio wave transmittance, and the visible light reflectance is an evaluation related to the luminosity. The larger the values of the visible light reflectance and the sheet resistance are, the better the value of the radio wave transmission attenuation is.

Details of the evaluation method are as follows.

(1) Sheet resistance

The measurement was carried out in the same manner as in the above "< 5-1 > (1)".

The sheet resistance is required to be 90 Ω/□ or more, preferably 200 Ω/□ or more, more preferably 250 Ω/□ or more, and further preferably 600 Ω/□ or more. When the ratio is less than 90 Ω/□, there is a problem that sufficient radio wave transmittance cannot be obtained.

(2) Attenuation of radio wave transmission

Measurement and evaluation were carried out in the same manner as in the above-mentioned "< 5-1 > (2)". More specifically, since the electromagnetic wave transmittance in the millimeter wave radar range (76 to 80GHz) and the electromagnetic wave transmittance in the microwave range (1GHz) have a correlation and show relatively close values, the electromagnetic wave transmittance in the microwave range (1GHz) (that is, the microwave electric field transmission attenuation) is used as an index in this evaluation.

The microwave electric field transmission attenuation is required to be 10 < -dB or less, preferably 5 < -dB or less, and more preferably 2 < -dB or less. If it is 10-dB or more, there is a problem that 90% or more of the electromagnetic wave is blocked.

(3) Reflectance of visible light

The reflectance at a measurement wavelength of 550nm was measured using a spectrophotometer U4100 manufactured by Hitachi High-Technologies. The reflectance of the Al deposition mirror surface was set as 100% as a standard.

In order to have sufficient brightness, the visible light reflectance needs to be 20% or more, preferably 40% or more, and more preferably 50% or more. When the visible light reflectance is less than 20%, the brightness is lowered and the appearance is poor.

(4) Thickness of the metal layer

"maximum thickness" was measured in the same manner as in "< 5-1 > (4)" described above.

The evaluation results are shown in table 2 below.

[ Table 2]

[ example 12]

A PET film (thickness: 125 μm) manufactured by Mitsubishi resin corporation was used as a base film.

First, an ITO layer having a thickness of 50nm was directly formed thereon along the surface of the substrate film by DC magnetron sputtering. Shape ofThe temperature of the substrate film in forming the ITO layer was set to 130 ℃. In ITO, In contrast to In₂O₃Contains 10 wt% of Sn.

Next, an aluminum (Al) layer having a maximum thickness of 50nm was formed on the ITO layer by AC sputtering (MF-AC sputtering using a middle frequency region of 40 kHz) to obtain a metallic luster member (metal film). The temperature of the substrate film when the Al layer was formed was set to 130 ℃, and the pressure of argon (Ar) gas in the chamber in which the substrate film was housed was set to 0.22 Pa.

Fig. 2(b) is an SEM image of the surface of the metallic luster member (metal film) obtained as a result of these treatments, and fig. 4 is a sectional image of a partial region of fig. 2(b), the image size being 1.16 μm × 0.85 μm. It is considered that the same cross section as that obtained in example 1 and the like was obtained.

As is clear from these figures, in the present example, the ITO layer of the metallic luster member was provided in a continuous state along the surface of the base film, and therefore had high smoothness and corrosion resistance, while the aluminum layer included a plurality of portions 12a formed discontinuously by being laminated on the ITO layer, and therefore had a sheet resistance of 260 Ω/□, and had an electromagnetic wave transmission attenuation of 4.5[ -dB ] at a wavelength of 1GHz, and good results were obtained for the electromagnetic wave transmission. In Table 1, for convenience, as a result of "evaluation" of the electromagnetic wave transmission attenuation, the case where the electromagnetic wave transmission attenuation is smaller than 2 < -dB is represented by "excellent", the case where the electromagnetic wave transmission attenuation is 2 < -dB or more and smaller than 5 < -dB is represented by "O", the case where the electromagnetic wave transmission attenuation is 5 < -dB or more and smaller than 10 < -dB is represented by "Δ", and the case where the electromagnetic wave transmission attenuation is 10 < -dB or more is represented by "X".

In addition, the visible light reflectance of the metallic luster member was 56%, and good results were obtained with respect to the glitter. For convenience, in table 1, as a result of "evaluation" of the visible light reflectance, a case where the visible light reflectance is greater than 50% is represented by "excellent", a case where the visible light reflectance is 50% or less and greater than 40% is represented by "o", a case where the visible light reflectance is 40% or less and greater than 20% is represented by "Δ", and a case where the visible light reflectance is 20% or less is represented by "x". Further, as the "comprehensive evaluation" of the electromagnetic wave transmittance and the luminosity, the same evaluation result is shown in the case where both are the same evaluation result, and the inferior evaluation result is shown in the case where one is inferior to the other. As a result, example 11 was evaluated as "o" in its entirety, and a metallic glossy member or a metallic film having both good electromagnetic wave permeability and good glitter was obtained.

[ example 13] to [ example 15]

In examples 13 and 14, the maximum thickness of the aluminum layer laminated on the ITO layer was changed to be thinner than that in example 12, while in example 15, the maximum thickness was changed to be thicker than that in example 12, and other conditions were the same as in example 12.

In this case, the sheet resistance and the electromagnetic wave transmission attenuation were the same as those of examples 13 to 15, and the same values and results as those of example 12 were obtained. On the other hand, regarding the visible light reflectance, the results of examples 13 and 14 in which the maximum thickness of the aluminum layer was thinner than that of example 12 were slightly inferior, but in example 15, the results were better than those of example 12. However, examples 13 and 14 can sufficiently withstand practical use.

[ example 16] to [ example 17]

The thickness of the ITO layer was set to be thinner than that of example 12, and other conditions were the same as example 12.

In this case, the sheet resistance and the electromagnetic wave transmission attenuation were better in examples 16 to 19 than in example 12. In examples 16 to 19, the same values and results as in example 12 were obtained for the visible light reflectance. According to these embodiments, the thickness of the ITO layer can be reduced, and the material cost can be suppressed by reducing the thickness of the ITO layer.

Examples 20 to 23