Patent Description:
A metallic lustrous member having both lustrousness and electromagnetic wave transmissibility is needed, for example, to decorate a cover member of a millimeter-wave radar mounted to a front component such as a front grille or an emblem at a front end of an automotive vehicle.

The millimeter-wave radar is configured to transmit an electromagnetic wave having a millimeter waveband (frequency: about <NUM>, wavelength: about <NUM>) forwardly with respect to the vehicle, and receive and analyze a reflected wave from a target so as to measure a distance or a direction with respect to the target, or the size of the target. A result of the measurement can be utilized for inter-vehicle distance measurement, automatic vehicle speed adjustment, automatic brake adjustment, etc. The front component of the vehicle to which the millimeter-wave radar is mounted is a portion constituting, so to say, the face of the vehicle, and having a great impact on a user. Thus, it is preferable to create a high-class appearance by a metallic lustrous front decoration. However, if the front component of the vehicle is made of a metal material, it will substantially preclude or hinder the millimeter-wave radar from emitting and receiving an electromagnetic wave. Therefore, in order to prevent hindering of the function of the millimeter-wave radar without spoiling an aesthetic appearance of the vehicle, there is a need for a metallic lustrous member having both lustrousness and electromagnetic wave transmissibility.

In addition to application to millimeter-wave radars, this type of metallic lustrous member is expected to be applied to various other devices requiring signal transmitting-receiving, e.g., a door handle module of an automotive vehicle using a smart key, in-vehicle communication devices, and electronic devices such as a mobile phone and a personal computer. Further, in recent years, along with development in IoT technologies, the metallic lustrous member is also expected to be applied to a wide range of fields, e.g., home or daily-life appliances such as a refrigerator, in which signal transmitting-receiving has heretofore not been performed.

With regard to the metallic lustrous member, in <CIT> (Patent Document <NUM>), there is disclosed a resin product comprising a metal coating or film made of chromium (Cr) or indium (In). This resin product comprises: a resin substrate; an inorganic underlying film (inorganic undercoating) containing an inorganic compound and formed on the resin substrate; and the metal film made of chromium (Cr) or indium (In), wherein the metal film is formed on the inorganic underlying film by a physical vapor deposition process to have a lustrous and discontinuous structure. In the Patent Document <NUM>, the inorganic underlying film is composed of (a) a thin film of a metal compound such as: a titanium compound including titanium oxide (TiO, TiO<NUM>, Ti<NUM>O<NUM>, etc.); a silicon compound including silicon oxide (SiO, SiO<NUM>, etc.) or silicon nitride (Si<NUM>N<NUM>, etc.); an aluminum compound including aluminum oxide (Al<NUM>O<NUM>); an iron compound including iron oxide (Fe<NUM>O<NUM>); a selenium compound including selenium oxide (CeO); a zircon compound including zircon oxide (ZrO); or a zinc compound including zinc sulfide (ZnS), or (b) a coating film made of an inorganic coating material, e.g., a coating film made of an inorganic coating material comprising a primary component consisting of silicon, amorphousTiO<NUM> or the like (additionally, any of the metal compounds exemplified above). However, this resin product is based on the assumption of using only chromium (Cr) or indium (In) as a material for the metal film. In other words, a metal superior to chromium and indium in terms of cost and lustrousness, such as aluminum (Al), cannot be used as a material for the metal film.

Further, in <CIT> (Patent Document <NUM>), there is disclosed a lustrous resin product with electromagnetic wave transmissibility, comprising a metal film which may be formed of not only chromium (Cr) or indium (In) but also aluminum (Al), silver (Ag) or nickel (Ni). In the Patent Document <NUM>, an underlying film having a discontinuous structure is provided, and then the metal film is formed on each of a plurality of discontinuous portions of the underlying film. However, due to restrictions, such as a requirement that an inclination angle of a substrate during sputtering must be set to <NUM>° or <NUM>° to form the underlying film in a discontinuous layer, there is a problem of complexity in production process. Further, in the Patent Document <NUM>, it is impossible to form the metal film, using zinc (Zn), lead (Pb) or copper (Cu), or an alloy thereof. Documents <CIT> and <CIT> disclose coated articles comprising a substrate and an indium oxide layer thereon further coated by a metallic discontinuous layer.

The present invention has been made to solve the above conventional problems, and an object thereof is to provide a metallic lustrous member with electromagnetic wave transmissibility, which is capable of being easily produced, even when using, as a material for a metal layer thereof, not only chromium (Cr) or indium (In) but also any of some other metals such as aluminum (Al). It is another object of the present invention to provide a metallic lustrous member with electromagnetic wave transmissibility, which is capable of using, as a material for a metal layer thereof, zinc (Zn), lead (Pb) or copper (Cu), or an alloy thereof, in addition to aluminum (Al) or silver (Ag).

As a result of diligent studies for solving the above problems, the present inventors found that, by using an indium oxide-containing layer as an underlying layer, it becomes possible to form, into a discontinuous structure, a metal layer made of not only chromium (Cr) or indium (In) but also any of some other metals such as aluminum (Al), which normally has difficulty in being formed into a discontinuous structure, and have reached accomplishment of the present invention.

In order to solve the above problems, , there is provided a metallic lustrous member with electromagnetic wave transmissibility, which comprises an indium oxide-containing layer provided along a surface of a substrate, and a metal layer laminated on the indium oxide-containing layer, wherein the metal layer includes, in at least part thereof, a plurality of portions which are in a discontinuous state.

In the metallic lustrous member with electromagnetic wave transmissibility, according to the present invention, by using the indium oxide-containing layer as an underlying layer, it becomes possible to form, into a discontinuous structure, even a metal layer made of a metal such as aluminum (Al) which normally has difficulty in being formed into a discontinuous structure, and thereby a sheet resistance thereof can be increased to improve electromagnetic wave transmissibility. In this way, it becomes possible to provide a metallic lustrous member with electromagnetic wave transmissibility, which is capable of being easily produced, using, as a material for the metal layer, not only chromium (Cr), indium (In) but also any of some other metals such as aluminum (Al). It also becomes possible to provide a metallic lustrous member with electromagnetic wave transmissibility, using, as a material for the metal layer, silver (Ag), zinc (Zn), lead (Pb) or copper (Cu), or an alloy thereof, in addition to aluminum (Al).

Preferably, in the metallic lustrous member with electromagnetic wave transmissibility, according to the present invention, the indium oxide-containing layer is provided in a continuous state. By providing the indium oxide-containing layer in a continuous state, it is possible to improve smoothness and corrosion resistance, and to facilitate forming the indium oxide-containing layer without any in-plane variation.

Here, the substrate may be one selected from the group consisting of a substrate film, a resin molded substrate, a glass substrate, and an article body to be imparted with metallic luster.

In the metallic lustrous member with electromagnetic wave transmissibility, according to the present invention, the indium oxide-containing layer may be made of one selected from the group consisting of indium oxide (In<NUM>O<NUM>), indium tin oxide (ITO) and indium zinc oxide (IZO).

In the metallic lustrous member with electromagnetic wave transmissibility, according to the present invention, the indium oxide-containing layer has a thickness of <NUM> to <NUM>. In the metallic lustrous member with electromagnetic wave transmissibility, according to the present invention, the metal layer has a thickness of <NUM> to <NUM>. Preferably, in the metallic lustrous member with electromagnetic wave transmissibility, according to the present invention, a 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 from <NUM> to <NUM>.

Preferably, in the metallic lustrous member with electromagnetic wave transmissibility, according to the first aspect of the present invention, a laminate of the metal layer and the indium oxide-containing layer has a sheet resistance of <NUM> to <NUM>,<NUM>Ω/□.

In the metallic lustrous member with electromagnetic wave transmissibility, according to the present invention, each of the portions may be formed in an island shape.

In the metallic lustrous member with electromagnetic wave transmissibility, according to the first aspect of the present invention, the metal layer may be made of one selected from the group consisting of aluminum (Al) and alloys thereof.

According to a second aspect outside the scope of the present invention, there is provided an article which uses the substrate film, the resin molded substrate or the glass substrate, or an article in which the member is provided on the article body to be imparted with metallic luster.

According to a third aspect outside the scope of the present invention, there is provided a metal thin film which is provided along a surface of a substrate, wherein the metal thin film has a thickness of <NUM> to <NUM>, and includes, in at least part thereof, a plurality of island-shaped portions which are in a discontinuous state.

The metal thin film may be formed in a transferable manner. In this case, the metal thin film can be easily provided on any of various article bodies.

The present invention can provide a metallic lustrous member with electromagnetic wave transmissibility, which is capable of being easily produced, even when using, as a material for a metal layer thereof, not only chromium (Cr) or indium (In) but also any of some other metals such as aluminum (Al). The present invention can also provide a metallic lustrous member with electromagnetic wave transmissibility, which is capable of using, as a material for a metal layer thereof, silver (Ag), zinc (Zn), lead (Pb) or copper (Cu), or an alloy thereof, in addition to aluminum (Al).

With reference to the accompanying drawings, a preferred embodiment of the present invention will now be described. Although only the preferred embodiment of the present invention will be shown in the following for the sake of convenience of explanation, it should be understood that the present invention is not limited thereto.

<FIG> is a schematic sectional view depicting a metallic lustrous member with electromagnetic wave transmissibility (hereinafter referred to as "metallic lustrous member") <NUM> according to one embodiment of the present invention, and an electromagnetic wave-transmissive metal film (hereinafter referred to as "metal film") <NUM> using the metallic lustrous member , and <FIG> is an electron microscope photograph (SEM image) presenting a surface of the metallic lustrous member <NUM> according to this embodiment. Here, an image size of the electron microscope photograph is <NUM> × <NUM>.

The metallic lustrous member <NUM> comprises an indium oxide-containing layer <NUM> containing at least indium oxide and serving as an underlying layer, and a metal layer <NUM> laminated on the indium oxide-containing layer <NUM>. The metal film <NUM> comprises the metallic lustrous member <NUM>, and a substrate film <NUM>. The indium oxide-containing layer <NUM> is provided on a surface of the substrate film <NUM> to be imparted with metallic luster. The indium oxide-containing layer <NUM> may be provided directly on the surface of the substrate film <NUM>, or may be provided indirectly on the surface of the substrate film <NUM> through a protective film or the like provided on the surface of the substrate film <NUM>. Preferably, the indium oxide-containing layer <NUM> is provided on the surface of the substrate film <NUM> to be imparted with metallic luster, in a continuous state, i.e., without any gap therebetween. By providing the indium oxide-containing layer <NUM> in a continuous state, it is possible to improve smoothness and corrosion resistance of the indium oxide-containing layer <NUM> and thus improve smoothness and corrosion resistance of the metallic lustrous member <NUM> and the metal film <NUM>, and to facilitate forming the indium oxide-containing layer <NUM> without any in-plane variation.

The metal layer <NUM> is laminated on the indium oxide-containing layer <NUM>. The metal layer <NUM> includes a plurality of portions 12a. In a state in which the metal layer <NUM> is laminated on the indium oxide-containing layer <NUM>, in at least part of the metal layer <NUM>, the portions 12a are in a discontinuous state, i.e., in at least part of the metal layer <NUM>, the portions 12a are separated from each other by a gap 12b. Because the portions 12a are separated from each other by the gap 12b, a sheet resistance in the portions 12a is increased, so that an interaction of the portions 12a with the electromagnetic wave is weakened to allow electromagnetic waves to be transmitted through the metal layer <NUM>. Each of the portions 12a is an aggregate of sputtered particles formed by subjecting a metal to vapor deposition, sputtering or the like. When the sputtered particles form a thin film on a substrate such as the substrate film <NUM>, surface diffusibility of the particles on the substrate exerts an influence on the shape of the thin film. As a result of diligent researches, the present inventors have succeeded in allowing the metal layer to grow in a discontinuous state by providing the indium oxide-containing layer on the substrate to promote the surface diffusibility of the metal layer. Here, as used in this specification, the term "discontinuous state" means a state in which the portions 12a are separated from each other by the gap 12b, and therefore electrically insulated from each other. As a result of the electrical insulation, the sheet resistance is increased, so that it becomes possible to obtain a desirable electromagnetic wave transmissibility. The configuration of the discontinuity is not particularly limited. For example, it may include an island-shaped configuration and a cracked configuration. Here, the term "island shape" means a structure in which the particles as the aggregate of the sputtered particles are independent of each other, and laid on the indium oxide-containing layer <NUM> in slightly spaced-apart relation to each other or in partially contact relation with each other, as presented in <FIG>.

As the substrate film <NUM>, it is possible to use a transparent film made of a homopolymer or copolymer of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, polyamide, polyvinyl chloride, polycarbonate (PC), cycloolefin polymer (COP), polystyrene, polypropylene (PP), polyethylene, polycycloolefin, polyurethane, polymethylmethacrylate (PMMA), or ABS. Such a transparent film has no influence on lustrousness and electromagnetic wave transmissibility. However, from a viewpoint of subsequently forming the indium oxide-containing layer <NUM> and the metal layer <NUM> thereon, it is desirable that the transparent film is capable of withstanding high temperatures during vapor deposition, sputtering or the like. Thus, among the above materials, e.g., polyethylene terephthalate, polyethylene naphthalate, polymethylmethacrylate, polycarbonate, cycloolefin polymer, ABS, polypropylene, and polyurethane are preferable. Among them, polyethylene terephthalate, cycloolefin polymer, polycarbonate and polymethylmethacrylate are particularly preferable, because they have a good balance between heat resistance and cost. The substrate film <NUM> may be a single-layer film or may be a laminate film. From a viewpoint of processability and the like, the thickness thereof is preferably from about <NUM> to <NUM>. With a view to enhancing adhesion with the indium oxide-containing layer <NUM>, it may be subjected to plasma treatment or easy-adhesion treatment.

It should be noted here that the substrate film <NUM> is merely one example of an object on which the metallic lustrous member <NUM> according to the present invention can be provided (this object will hereinafter be referred to as "substrate"). In addition to the substrate film <NUM>, the substrate includes a resin molded substrate, a glass substrate, and an article body to be imparted with metallic luster. Examples of the resin molded substrate include a resin substrate for an emblem of an automotive vehicle. Examples of the article body to be imparted with metallic luster includes a body of a door knob of an automotive vehicle using a smart key, and a housing (outer casing) of a mobile phone, a personal computer, a refrigerator or the like. The metallic lustrous member <NUM> according to the present invention can be provided on any of the above substrates. In this case, the substrate to be provided with the metallic lustrous member <NUM> preferably has the similar material to that of or satisfies the similar requirements to those of the above substrate film <NUM>.

As a material for the indium oxide-containing layer <NUM>, it is possible to use indium oxide (In<NUM>O<NUM>) itself, or a metal-containing substance such as indium tin oxide (ITO) or indium zinc oxide (IZO). Among them, ITO and IZO containing the second metal are more preferable in that they have high discharge stability in a sputtering process. By using the indium oxide-containing layer <NUM>, it becomes possible to form a continuous film along the surface of the substrate. In this case, it also becomes possible to laminate the metal layer on the indium oxide-containing layer, in e.g., an island-shaped discontinuous structure. Further, in this case, as a material for the metal layer, it becomes possible to use not only chromium (Cr) or indium (In) but also any of some other metals such as aluminum, which have been hardly used as the material because they normally have difficulty in being formed into a discontinuous structure, as described in more detail later. The content rate by weight of tin (Sn) to In<NUM>O<NUM> in ITO is not particularly limited. For example, it may be from <NUM> wt% to <NUM> wt%, preferably from <NUM> wt% to <NUM> wt%. Further, for example, the content rate by weight of zinc oxide (ZnO) to In<NUM>O<NUM> in IZO is may be from <NUM> wt% to <NUM> wt%. From a viewpoint of sheet resistance, electromagnetic wave transmissibility and productivity, the thickness of the indium oxide-containing layer <NUM> is generally preferably <NUM> or less, more preferably <NUM> or less, still more preferably <NUM> or less. On the other hand, from a viewpoint of laminating the metal layer <NUM> in a discontinuous state, the thickness of the indium oxide-containing layer <NUM> is preferably <NUM> or more, and, from a viewpoint of reliably obtaining the discontinuous state, it is more preferably <NUM> or more.

The metal layer <NUM> is essentially capable of bringing out sufficient lustrousness. Further, it is desirable that the melting point thereof is relatively low. This is because the metal layer <NUM> is created through thin-film growth using sputtering. For this reason, a metal having a melting point of about <NUM> or less is suitable as a material for the metal layer <NUM>. In the invention, the metal layer <NUM> is made of at least one metal selected from the group consisting of aluminum (Al), and optionally zinc (Zn), lead (Pb), copper (Cu) and silver (Ag).

With a view to allowing the metal layer <NUM> to bring out sufficient lustrousness, the thickness of the metal layer <NUM> is generally <NUM> or more. On the other hand, from a viewpoint of sheet resistance and electromagnetic wave transmissibility, the thickness of the metal layer <NUM> is generally <NUM> or less. Thus, for example, the thickness of the metal layer <NUM> is from <NUM> to <NUM>, more preferably from <NUM> to <NUM>. This thickness range is suited to forming a uniform film with good productivity, and can provide good appearance of a resin molded article as a final product.

Further, for the similar reasons, 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 from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

Further, it is preferable that a laminate of the metal layer and the indium oxide-containing layer has a sheet resistance of <NUM> to <NUM>,<NUM>Ω/□. In this case, the electromagnetic wave transmissibility of the laminate at a wavelength of <NUM> is from about <NUM> to <NUM> [- dB]. More preferably, the sheet resistance is from <NUM>,<NUM> to <NUM>,<NUM>Ω/□. The value of the sheet resistance is largely influenced by not only the material and thickness of the metal layer but also the material and thickness of the indium oxide-containing layer serving as an underlying layer. Therefore, the value of the sheet resistance needs to be set while taking into account the relationship with the indium oxide-containing layer.

If the metal layer <NUM> is formed directly on the substrate without providing the indium oxide-containing layer <NUM>, the metal layer <NUM> is formed on the substrate <NUM> in a continuous state. In this case, although sufficient lustrousness can be obtained, the sheet resistance becomes significantly small, so that it is impossible to ensure the electromagnetic wave transmissibility. Differently, in the case where the metal layer <NUM> is laminated on the indium oxide-containing layer <NUM> formed on the substrate, the metal layer <NUM> is formed, in a discontinuous state, e.g., on the indium oxide-containing layer <NUM> formed in a continuous state, so that it is of course possible to obtain sufficient lustrousness and also possible to ensure the electromagnetic wave transmissibility. Although details of a mechanism causing the metal layer <NUM> to become a discontinuous state on the indium oxide-containing layer <NUM> is not exactly clear, it is inferred as follows. That is, in a thin film forming process for the metal layer <NUM>, easiness in forming a discontinuous structure of the metal layer <NUM> is relevant to surface diffusibility of the metal layer <NUM> on a to-be-coated member (in this embodiment, the indium oxide-containing layer <NUM>) to be coated with the metal layer <NUM>. Specifically, the discontinuous structure is more likely to be formed under the condition that: the temperature of the to-be-coated member is higher; the wettability of the metal layer with respect to the to-be-coated member is smaller; and the melting point of the metal layer is lower. Therefore, in regard to some metals other than aluminum (Al) used particularly in the following Examples, such as zinc (Zn), lead (Pb), copper (Cu) and silver (Ag) each having a relatively low melting point, the discontinuous structure is considered to be able to be formed in the similar manner.

One example of a production method for the metallic lustrous member <NUM> will be described by taking an example in which the substrate film <NUM> is used as the substrate, i.e., the metal film <NUM> is produced. Although not particularly described, a metallic lustrous member using the substrate other than the substrate film <NUM> can also be produced by the similar method.

The indium oxide-containing layer <NUM> is formed onto the substrate film <NUM>. The indium oxide-containing layer <NUM> can be formed by vacuum deposition, sputtering, ion plating or the like. Among them, sputtering is preferable, from a viewpoint of being capable of strictly controlling the thickness of the indium oxide-containing layer <NUM> even when it has a relatively large area.

Subsequently, the metal later <NUM> is laminated to the indium oxide-containing layer <NUM>. In this case, for example, sputtering can be used. Preferably, the metal layer <NUM> is laminated such that it comes into direct contact with the indium oxide-containing layer <NUM> without interposing any additional layer therebetween. However, as long as the above mechanism based on surface diffusibility of the metal layer <NUM> on the indium oxide-containing layer <NUM> effectively functions, an additional layer may be interposed therebetween.

The present invention will be more specifically described below by taking inventive examples and comparative examples. Various samples of the metal film <NUM> were prepared, and evaluated in terms of sheet resistance, electromagnetic wave transmission attenuation amount, and visible light reflectance. The sheet resistance and the electromagnetic wave transmission attenuation amount are evaluation indexes of the electromagnetic wave transmissibility, and the visible light reflectance is an evaluation index of the lustrousness. A larger value of each of the visible light reflectance and the sheet resistance is more desirable, and a smaller value of the electromagnetic wave transmission attenuation amount is more desirable.

Details of evaluation methods are as follows.

The sheet resistance was measured by an eddy-current measurement method in accordance with JIS-Z2316, using a non-contact type resistance measuring device NC-80MAP manufactured by Napson Corporation.

This sheet resistance needs to be equal to or greater than <NUM>Ω/□, preferably equal to or greater than <NUM>Ω/□, more preferably equal to or greater than <NUM>Ω/□. If the sheet resistance is less than <NUM>Ω/□, there is a problem that a sufficient electromagnetic wave transmissibility cannot be obtained.

An electromagnetic wave transmission attenuation amount at <NUM> was evaluated using a KEC method measurement and evaluation jig, and a spectral analyzer CXA signal Analyzer NA9000A manufactured by Agilent technologies Inc. An electromagnetic wave transmissibility in a frequency band (<NUM> to <NUM>) of a millimeter-wave radar is correlated with an electromagnetic wave transmissibility in a microwave band (<NUM>), and thus they exhibit relatively close values. Thus, in this evaluation, the electromagnetic wave transmissibility, i.e., microwave electric field transmission attenuation amount, in the microwave microwave band (<NUM>), was used as an index.

This microwave electric field transmission attenuation amount needs to be equal to or less than <NUM> [- dB], preferably, equal to or less than <NUM> [- dB], more preferably equal to or less than <NUM> [- dB]. If the electromagnetic wave transmission attenuation amount is equal to or greater than <NUM> [- dB], there is a problem that <NUM>% or more of an electromagnetic wave is shielded.

A reflectance at a measurement wavelength of <NUM> was measured using a spectrophotometer U4100 manufactured by Hitachi High Technologies Co. As a reference value, the reflectance of an Al-deposited mirror was defined as a reflectance of <NUM>%.

In order to have a sufficient lustrousness, the visible light reflectance need to be equal to or greater than <NUM>%, preferably equal to or greater than <NUM>%, more preferably equal to or greater than <NUM>%. If the visible light reflectance is less than <NUM>%, there is a problem that the lustrousness significantly deteriorates, resulting in failing to ensure excellent external appearance.

A result of the evaluations is presented in the following Table <NUM>.

A PET film (thickness: <NUM>) manufactured by Mitsubishi Plastics, Inc. was used as a substrate film
First of all, using DC magnetron sputtering, a <NUM>-thick ITO layer was formed directly on a surface of the substrate film to extend along a surface of the substrate film. The temperature of the substrate film during formation of the ITO layer was set at <NUM>. The ITO is a composition obtained by adding Sn to In<NUM>O<NUM> in an amount of <NUM> wt%.

Subsequently, using AC sputtering (AC: <NUM>), a <NUM>-thick aluminum (Al) layer was formed on the ITO layer to obtain a metallic lustrous member (metal film). The temperature of the substrate film during formation of the Al layer was set at <NUM>.

<FIG> is an electron microscope photograph (SEM image) of a surface of the metallic lustrous member (metal film) obtained as a result of the above process, and <FIG> is an image of a cut surface in a partial region of <FIG>. Here, an image size of the electron microscope photograph in <FIG> is <NUM> × <NUM>.

In Inventive Example <NUM>, as is evident from these figures, the ITO layer of the metallic lustrous member is provided along the surface of the substrate film in a continuous state, so that high smoothness and corrosion resistance could be obtained, and, on the other hand, the aluminum layer laminated on the ITO layer includes a plurality of portions 12a formed in a discontinuous state, so that the sheet resistance was <NUM>Ω/□, and the electromagnetic wave transmission attenuation amount at a wavelength of <NUM> was <NUM> [- dB], i.e., in terms of the electromagnetic wave transmissibility, a good result could be obtained. In Table <NUM>, with regard to a result of "evaluation" of the electromagnetic wave transmission attenuation amount, when the electromagnetic wave transmission attenuation amount is less than <NUM> [-dB], the electromagnetic wave transmissibility was evaluated as "⊚", and, when the electromagnetic wave transmission attenuation amount is from <NUM> [- dB] to less than <NUM> [- dB], the electromagnetic wave transmissibility was evaluated as "O". Further, when the electromagnetic wave transmission attenuation amount is from <NUM> [- dB] to less than <NUM> [-dB], the electromagnetic wave transmissibility was evaluated as "Δ", and, when the electromagnetic wave transmission attenuation amount is <NUM> [- dB] or more, the electromagnetic wave transmissibility was evaluated as "×".

Further, the visible light reflectance of the metallic lustrous member was <NUM>%, i.e., in terms of the visible light reflectance, a good result could be obtained. For the sake of simplicity, in Table <NUM>, with regard to a result of "evaluation" of the visible light reflectance, when the visible light reflectance is greater than <NUM>%, the lustrousness was evaluated as "⊚", and, when the visible light reflectance is from <NUM>% to greater than <NUM>%, the lustrousness was evaluated as "O". Further, when the visible light reflectance is from <NUM>% to greater than <NUM>%, the lustrousness was evaluated as "Δ", and, when the visible light reflectance is <NUM>% or less, the lustrousness was evaluated as "×". Further, with respect to "comprehensive evaluation" of the electromagnetic wave transmissibility and the lustrousness, when the two properties have the same evaluation, the same evaluation is indicated in the field, and, when the evaluation of one of the properties is worse than that of the other property, the worse evaluation is indicated in the field. As a result, in Inventive Example <NUM>, the comprehensive evaluation was "○", i.e., a good metallic lustrous member or metal film having both the electromagnetic wave transmissibility and the lustrousness could be obtained.

In Inventive Examples <NUM> and <NUM>, the thickness of the aluminum layer laminated on the ITO layer was changed to a smaller value than that in Inventive Example <NUM>. On the other hand, in Inventive Example <NUM>, the thickness was changed to a larger value than that in Inventive Example <NUM>. The remaining conditions were the same as those in Inventive Example <NUM>.

As a result of the measurements, with respect to the sheet resistance and the electromagnetic wave transmission attenuation amount, similar values and evaluations to those in Inventive Example <NUM> could be obtained in each of Inventive Examples <NUM> to <NUM>. On the other hand, with respect to the visible light reflectance, in each of Inventive Examples <NUM> and <NUM> in which the thickness of the aluminum layer is smaller than that in Inventive Example <NUM>, a value was slightly inferior to that in Inventive Example <NUM>, whereas, in Inventive Example <NUM>, a better value than that in Inventive Example <NUM> could be obtained. However, even in Inventive Examples <NUM> and <NUM>, it is possible to ensure sufficient practicality.

The thickness of the ITO layer was changed to a smaller value than that in Inventive Example <NUM>. The remaining conditions were the same as those in Inventive Example <NUM>.

As a result of the measurements, with respect to the sheet resistance and the electromagnetic wave transmission attenuation amount, better values than those in Inventive Example <NUM> could be obtained in each of Inventive Examples <NUM> to <NUM>. Further, with respect to the visible light reflectance, a similar value and evaluation to those in Inventive Example <NUM> could be obtained in each of Inventive Examples <NUM> to <NUM>. From these Inventive Examples, it has become apparent that the thickness of the ITO layer may be reduced, i.e., that a material cost can be reduced by reducing the thickness of the ITO layer.

In Inventive Example <NUM>, the content rate of Sn in the ITO layer was changed to a larger value than that in Inventive Example <NUM>. On the other hand, in Inventive Examples <NUM> to <NUM>, the content rate was changed to a smaller value than that in Inventive Example <NUM>. Here, in Inventive Example <NUM>, the content rate of Sn in the ITO layer is set to zero. Thus, to be exact, this layer is not an ITO layer but an indium oxide (In<NUM>O<NUM>) layer. Further, in Inventive Example <NUM>, the thickness of the aluminum layer was set to <NUM>. The remaining conditions were the same as those in Inventive Example <NUM>.

As a result of the measurements, with respect to the sheet resistance and the electromagnetic wave transmission attenuation amount, similar values to those in Inventive Example <NUM> could be obtained in each of Inventive Examples <NUM> to <NUM>, and values in Inventive Example <NUM> were slightly inferior to those in Inventive Example <NUM>. On the other hand, with respect to the visible light reflectance, in each of Inventive Examples <NUM> to <NUM>, a similar value and evaluation to those in Inventive Example <NUM> could be obtained, whereas a value in Inventive Example <NUM> was slightly inferior to that in Inventive Example <NUM>. From these results, it has become apparent that the ITO layer preferable contains Sn.

As a material for the indium oxide-containing layer, IZO obtained by adding ZnO to indium oxide was used, instead of ITO. ZnO is added to In<NUM>O<NUM> in an amount of <NUM> wt%. The remaining conditions were the same as those in Inventive Example <NUM>.

As a result of the measurements, with respect to the sheet resistance and the electromagnetic wave transmission attenuation amount, values in Inventive Example <NUM> were slightly inferior to those in Inventive Example <NUM>. On the other hand, with respect to the visible light reflectance, a similar value and evaluation to those in Inventive Example <NUM> could be obtained. It has become apparent that, even using IZO to which ZnO is added, sufficient practicality can be ensured, although the comprehensive example in Inventive Example <NUM> is inferior to that in Inventive Example <NUM>.

The thickness of the aluminum layer laminated on the ITO layer was changed to a larger value than that in Inventive Example <NUM>. The remaining conditions were the same as those in Inventive Example <NUM>.

As a result of the measurements, with respect to the visible light reflectance, due to the increase in thickness, a better value than that in Inventive Example <NUM> could be obtained. On the other hand, with respect to the sheet resistance and the electromagnetic wave transmission attenuation amount, values in Comparative Example <NUM> were significantly inferior to those in Inventive Example <NUM>, and evaluated as impractical.

The aluminum layer was formed directly on the substrate film without providing any ITO layer. The remaining conditions were the same as those in Inventive Example <NUM>.

As a result of the measurements, with respect to the visible light reflectance, a similar value and evaluation to those in Inventive Example <NUM> could be obtained. On the other hand, with respect to the sheet resistance and the electromagnetic wave transmission attenuation amount, values in Comparative Example <NUM> were significantly inferior to those in Inventive Example <NUM>, and evaluated as impractical.

The metal layer <NUM> formed in the metallic lustrous member <NUM> has a small thickness of about <NUM> to <NUM>, and can be used by itself as a metal thin film. For example, the metal layer <NUM> may be formed on the indium oxide-containing layer <NUM> laminated on a substrate such as the substrate film <NUM> by sputtering to obtain a film. Further, separately from this, an adhesive is applied onto a substrate to produce an adhesive layer-attached substrate. Then, the film is laminated to the adhesive layer-attached substrate, such that the metal layer <NUM> comes in contact with the adhesive layer. In this way, the metal layer (metal thin film) <NUM> which has been located on the outermost surface side of the film can be transferred to the outermost surface side of the adhesive layer-attached substrate, by separating the film and the substrate from each other, after fully having contacted them.

Claim 1:
A metallic lustrous member (<NUM>) with electromagnetic wave transmissibility, comprising an indium oxide-containing layer (<NUM>) provided on a surface of a substrate in a continuous state, and
a metal layer (<NUM>) laminated on the indium oxide-containing layer, wherein the metal layer includes, in at least part thereof, a plurality of portions (12a) which are separate and electrically insulated from each other;
wherein the metal layer has a thickness of <NUM> to <NUM> and is formed of aluminum (Al) and optionally one of the following: zinc (Zn), lead (Pb), copper (Cu) or silver (Ag) and alloys thereof;
the indium oxide-containing layer has a thickness of <NUM> to <NUM> and is made of one selected from the group consisting of indium oxide (In<NUM>O<NUM>), indium tin oxide (ITO) and indium zinc oxide (IZO);
the laminate of the metal layer and the indium oxide-containing layer has a sheet resistance of equal to or greater than <NUM> Q/o; and
the metallic lustrous member has an electromagnetic wave transmission attenuation amount at <NUM> of equal to or less than <NUM> [-dB] and a visible light reflectance of equal to or greater than <NUM>%.