JP7281382B2 - Indium-evaporated retention film, metal-tone multilayer film, manufacturing method for indium-deposited retention film, manufacturing method for metal-tone multilayer film, and emblem - Google Patents

Description

The present invention relates to an indium-deposited retaining film, a metallic multilayer film, a method for manufacturing an indium-deposited retaining film, a method for manufacturing a metallic multilayer film, and an emblem.

Sensors such as millimeter wave radars are used to detect obstacles around vehicles such as motorcycles and automobiles. A millimeter-wave radar is a device that measures the distance to an obstacle by irradiating an obstacle with radio waves with a wavelength of 1 to 10 mm and measuring the time it takes for the radio wave to return from the obstacle. Millimeter-wave radar is less affected by weather conditions such as rain and fog, and can detect distant obstacles, so many automobile manufacturers have introduced it.

Millimeter-wave radar for automobiles uses a millimeter-wave band in the range of 76 to 77 GHz. passes through the emblem from the main body of the device and illuminates the obstacle.

For example, as a bright decorative molding for use in the beam path of a radar device that can be used for such an emblem, Patent Document 1 discloses a substrate made of a transparent resin layer and a colored primer layer (undercoat) provided on the back surface of the substrate. coating layer) and a metal layer consisting of one or more layers of an indium layer, an indium alloy layer, a tin layer, and a tin alloy layer provided on the back surface of the primer layer (undercoat layer). A decorative molding is disclosed.

JP-A-2006-264593

Emblems with metallic luster are used from the point of view of decorativeness, and the emblem behind which the millimeter-wave radar device body is installed has a metallic luster that is visible in addition to the transparency of the millimeter-wave band. Reflectivity in the visible range is required. Transmittance in the millimeter wave band and reflectivity in the visible range can be said to be contradictory properties, but recently, automobile manufacturers and others require higher performance for these properties as a condition for adopting emblems. There is

For example, the performance of a metallic multilayer film that can be applied as an emblem material is a millimeter wave transmission attenuation of -1.0 dB as a measure of transmittance in the millimeter wave band, and a measure of reflectivity in the visible region. It is required that the total light transmittance is 1.3% to 30% or less.

However, conventional metallic multilayer films could not meet such high performance in terms of transmittance in the millimeter wave band and reflectance in the visible region.

In view of the above problems, the present invention provides an indium-deposited holding film, a metallic-tone multilayer film, and a method for producing an indium-deposited holding film, which are capable of achieving higher performance in terms of transmittance in the millimeter wave band and reflectance in the visible region. , a method for producing a metallic multilayer film, and an emblem.

In order to solve the above-mentioned problems, an indium-deposited holding film of the present invention is an indium-deposited holding film comprising an indium-deposited layer and a holding film layer holding the indium-deposited layer, wherein the indium-deposited layer comprises: The holding film layer has a sea-island structure in which indium is scattered in an island shape, and the island-like indium is 150×10 ⁶ on the surface of the indium deposition layer in the direction perpendicular to the direction in which the indium is deposited. particles/cm ² or more, the total length of the perimeter of the island-shaped indium on the surface is 100×10 ⁶ μm/cm ² or more, and the millimeter wave transmission attenuation of the indium-deposited holding film is , within −1.0 dB, and the total light transmittance of the indium deposition holding film is 1.3% to 30%.

On the surface, the area of the island-shaped indium may be 0.01 μm ² to 0.4 μm ² .

The holding film layer may be a polyethylene terephthalate-based resin layer having a thickness of 5 μm to 50 μm.

In order to solve the above problems, the metallic multilayer film of the present invention comprises, in order, a base film layer, an indium vapor deposited layer laminated on the base film layer, and a holding film layer holding the indium vapor deposited layer. A metallic multilayer film comprising the above-described indium-deposited holding film of the present invention and a protective film layer laminated with the holding film layer, wherein the millimeter wave transmission attenuation of the metallic multilayer film is - It is within 1.0 dB, and the total light transmittance of the metallic multilayer film is 1.3% to 30%.

The base film layer may be a polycarbonate resin layer having a thickness of 50 μm to 1000 μm, and the protective film layer may be a polycarbonate resin layer having a thickness of 50 μm to 200 μm.

The metallic multilayer film of the present invention comprises a first polyurethane-based adhesive layer that bonds the base film layer and the indium-deposited layer, and a second polyurethane-based adhesive layer that bonds the holding film layer and the protective film layer. You may prepare.

Further, in order to solve the above problems, a method for producing an indium-deposited holding film of the present invention is the above-described method for producing an indium-deposited holding film of the present ^invention , wherein Under a pressure condition of ×10 ^-2 Pa, the holding film layer along a roll with a temperature of -5°C to 5°C is exposed to an indium vapor stream to form the indium deposition layer on the holding film layer. a vapor deposition step; a measuring step of measuring the total light transmittance of a laminate of the indium vapor-deposited layer and the holding film layer obtained by the vapor deposition step; and a total light transmittance of the laminate obtained by the measuring step. and a control step of controlling the formation rate of the indium deposition layer so that the indium vapor deposition layer is 1.3% to 30%.

Further, in order to solve the above problems, the method for producing a metallic multilayer film of the present invention provides the indium vapor-deposited layer of the indium-deposited holding film obtained by the method for producing the indium-deposited holding film of the present invention, A first lamination step of laminating the base film layer, and a second lamination step of laminating the holding film layer of the indium-deposited holding film, and the protective film layer.

Moreover, in order to solve the above problems, the emblem of the present invention comprises the metallic multilayer film of the present invention.

INDUSTRIAL APPLICABILITY According to the present invention, an indium-deposited retention film, a metallic-tone multilayer film, a method for producing an indium-deposited retention film, and a metallic-tone multilayer, which can satisfy higher performance in terms of transmittance in the millimeter wave band and reflectance in the visible region. A film manufacturing method and an emblem can be provided.

1 is a schematic diagram showing a cross-sectional side view of an embodiment of a metallic multilayer film 100 of the present invention; FIG. 4 is an SEM image of a side cross-section of an indium deposition layer 20. FIG. 4 is an SEM image of the surface of the indium deposition layer 20 of Example 2 taken from a direction parallel to the direction in which indium is deposited. 1 is a schematic diagram of a vacuum deposition apparatus 200; FIG. FIG. 4 is a schematic diagram showing an example of the manufacturing process of the emblem 300; 4 is an SEM image of the surface of the indium deposition layer of Comparative Example 2 taken in a direction parallel to the direction in which indium is deposited.

BEST MODE FOR CARRYING OUT THE INVENTION An indium-deposited retaining film, a metallic multilayer film, a method for manufacturing an indium-deposited retaining film, a method for manufacturing a metallic multilayer film, and an emblem according to the present invention will be described below with reference to the drawings. In addition, the present invention is not limited to the following examples.

FIG. 1 shows a side cross section of a metallic multilayer film 100 as a schematic diagram of one embodiment of the metallic multilayer film of the present invention. The metallic multilayer film 100 is composed of a base film layer 10, an indium-deposited holding film layer 70, and a protective film layer 40, which are laminated in this order. The indium-deposited holding film layer 70 includes the indium-deposited layer 20 and the holding film layer 30 holding the indium-deposited layer 20 .

[Indium deposition holding film layer 70]
The millimeter wave transmission attenuation of the indium deposition holding film layer 70 is within -1.0 dB. If the millimeter wave transmission attenuation amount is within -1.0 dB, the millimeter wave band transmittance is extremely excellent. Therefore, for example, when a radio wave emitted by the main body of a millimeter-wave radar passes through the indium-deposited holding film layer 70, or when the irradiated radio wave is reflected by an obstacle and passes through the indium-deposited holding film layer 70, Attenuation of millimeter waves can be kept low. As a result, even when the indium-deposited holding film layer 70 is arranged on the irradiation path and the reflection path of the millimeter wave, the detection sensitivity of the millimeter wave radar to radio waves can be maintained at a high level.

Ideally, the upper limit of the millimeter wave transmission attenuation amount is 0 dB, but at present, the upper limit is about -0.2 dB. If the millimeter wave transmission attenuation is lower than -1.0 dB, the radio wave detection sensitivity of the millimeter wave radar is at a high level when the indium deposition holding film layer is arranged on the millimeter wave irradiation path and the reflection path. It may not be possible to maintain

In addition, the total light transmittance of the indium deposition holding film layer 70 is 30% or less. If the total light transmittance is 30% or less, the metallic luster of the indium-deposited holding film layer 70 can be visually recognized, and decorativeness and design can be satisfied. Although it is preferable that the total light transmittance is lower, it may become difficult to satisfy the transmission performance in the millimeter waveband, and the lower limit of the total light transmittance is currently 1.3%.

In addition, if the total light transmittance exceeds 30%, the visibility of the metallic luster is affected, and there is a possibility that the decorativeness and design are not satisfied.

<Indium deposition layer 20>
The indium deposition layer 20 included in the indium deposition holding film layer 70 is a layer formed by depositing indium, and has the same decorativeness and design as those of the plated parts used for decorative parts and parts made of metal materials. It is a layer capable of imparting sufficient metallic luster to the indium-evaporated holding film layer 70 and the metallic multilayer film 100 so as to impart a

In addition, forming a layer by vapor deposition of indium is advantageous when three-dimensional molding with deep drawing and an extremely small radius of curvature is performed. When used as a material for a decorative molded product, it is possible to impart decorativeness and design to the brilliant decorative molded product while following various shapes of the brilliant decorative molded product.

(Thickness of indium deposition layer 20)
The thickness of the indium deposited layer 20 is preferably 15 nm to 130 nm in consideration of decorativeness and design. If the thickness of the indium-deposited layer 20 is less than 15 nm, the metal-tone multilayer film 100 including the indium-deposited holding film layer 70 may not be provided with sufficient metallic luster, and the decorativeness and design may not be satisfied. There is On the other hand, if the thickness of the indium vapor deposition layer 20 exceeds 130 nm, the effect on decorativeness and design is saturated, and furthermore, the manufacturing cost of the metallic multilayer film 100 including the indium vapor deposition holding film layer 70 increases. In addition, there is a risk that an indium vapor deposition layer that cannot transmit millimeter waves may be formed because a sea-island structure is not formed. Note that, depending on the configuration of the metallic multilayer film 100 including the indium-deposited holding film layer 70 and the backlight, light may be transmitted through the indium-deposited layer 20 to produce decorativeness and design. In such a case, if the thickness of the indium deposition layer 20 is 15 nm to 50 nm, decorativeness and design can be satisfied. Normally, the thickness of the indium vapor deposition layer 20 is about 50 nm. For example, in the case of the light transmitting metallic multilayer film 100 including the indium vapor deposition holding film layer 70, the thickness of the indium vapor deposition layer 20 is about 25 nm. can be set to

FIG. 2 shows an SEM image of a side cross-section of the indium deposition layer 20 . In FIG. 2, a side cross-section of the holding film layer 30, the indium deposition layer 20, and the first polyurethane-based adhesive layer 50 laminated in this order from the bottom is photographed. The evaporated indium particles collide with the surface of the holding film layer 30 , and the indium deposition layer 20 adheres to the holding film layer 30 in a flattened shape. In addition, the region indicated by symbol A is a region between indium particles and other indium particles (hereinafter sometimes referred to as "region A"), but as in region A on the right side of FIG. The holding film layer 30 may be exposed without adhering, or may be integrated with adjacent indium particles to form recesses, as shown in region A on the left side of FIG.

Therefore, the thickness of the indium vapor deposition layer 20 is not constant, but in this specification, the thickness of the indium vapor deposition layer 20 is the distance L between the surface 31 of the holding film layer 30 and the surface 21 of the flattened indium particles and In particular, the indium deposition layer 20 is an important layer for imparting excellent decorativeness and design, and is preferably a uniform and thin layer.

(Sea-island structure of indium deposition layer 20)
The metallic multilayer film 100 including the indium deposition holding film layer 70 imparts excellent decorativeness and design, and also transmits radio waves in the range of 3.90 to 3.95 mm in wavelength and 76 to 77 GHz in frequency. It is required to have radio wave transparency to In particular, the indium-deposited layer 20 is an important layer for satisfying the excellent decorativeness and design of the metallic multilayer film 100 including the indium-deposited support film layer 70, and also has excellent radio wave transparency. is also an important layer.

Therefore, the indium-deposited layer 20 included in the indium-deposited holding film layer 70 has a sea-island structure in which the holding film layer 30 is dotted with islands of indium. It is important to have an islands-in-the-sea structure with islands and seas where the retention film layer 30 is exposed without indium particles adhering and where the islands are spaced apart from each other.

In order to specifically explain the sea-island structure, FIG. 3 shows an SEM image of the surface of the indium deposition layer 20 photographed from a direction parallel to the direction in which indium is deposited. The surface of the indium deposited layer 20 shown in FIG. 3 is the surface in the direction perpendicular to the direction in which indium is deposited. In FIG. 3, the entire circumference is surrounded by the sea portion S, and the portions that are island-shaped without being integrated with the adjacent indium particles are the island portions I, and there are a plurality of island portions.

Here, 150×10 ⁶ pieces/cm ² or more of island-shaped indium (that is, island portion I) exist on the surface of the indium vapor deposition layer 20 in the direction perpendicular to the indium vapor deposition direction. Furthermore, on the surface, the total length of the perimeter of the island-shaped indium (that is, the length of the sea portion S surrounding the island portion I and surrounding the island portion I) is 100×10 ⁶ μm/cm ² or more. be.

The number of island portions I per 1 cm ² of the surface of the indium deposition layer 20 and the length of the perimeter of the island portions I satisfy the above conditions, while maintaining the properties of imparting excellent decorativeness and design. In particular, it has excellent transmittance of radio waves in the range of wavelength 3.90-3.95 mm and frequency 76-77 GHz. As a result, the millimeter-wave transmission attenuation of the metallic multilayer film 100 including the indium-deposited holding film layer 70 can be suppressed to within -1.0 dB, and the total light transmittance can be within the range of 1.3% or more. .

If the above conditions are not met, the sea portion S through which millimeter waves can easily pass is reduced, or the length of the sea portion S surrounding the island portion I is shortened. may become less viable. In addition, the fact that the island portion I is small means that the integration with the adjacent indium particles proceeds to form a continuous layer of indium, and this continuous layer has conductivity and absorbs millimeter waves. This reduces the transmittance of millimeter waves. On the other hand, even if the above conditions are satisfied, if the total light transmittance exceeds 30%, there is a possibility that the properties of imparting decorativeness and designability may deteriorate.

Since the indium vapor deposition layer 20 has a sea-island structure that satisfies the above conditions, whitening phenomenon and the like can be prevented and metallic luster can be maintained even when three-dimensional deep drawing is performed. Designability can be imparted. Furthermore, it can have a radio wave transmittance that satisfactorily transmits radio waves having a wavelength of 3.90 to 3.95 mm and a frequency of 76 to 77 GHz.

In addition, by setting the area of the island-shaped indium on the surface to be 0.01 μm ² to 0.4 μm 2 , the number of island portions I per 1 ^{cm 2 of} the surface of the indium vapor deposition layer 20 and the circumference of the island portions I The length satisfies the above conditions. As a result, while maintaining the properties of imparting excellent decorativeness and design, it is particularly excellent in the transparency of radio waves in the wavelength range of 3.90 to 3.95 mm and the frequency of 76 to 77 GHz. The millimeter wave transmission attenuation of the metallic multilayer film 100 including the layer 70 can be suppressed within -1.0 dB.

The area of the island-shaped indium can be calculated by observing it with a SEM. Area may not be specified. Therefore, it is not necessarily a necessary condition that the area of the indium islands is 0.01 μm ² to 0.4 μm ² .

<Retaining film layer 30>
The holding film layer 30 included in the indium-deposited holding film layer 70 is a film that holds the indium-deposited layer 20 on one side thereof. The retention film layer 30 includes, for example, a transparent thermoplastic resin such as modified polyethylene terephthalate having a melting point of 230.degree. C. to 250.degree. As for the melting point of the holding film layer 30, the melting temperature specified by using a differential scanning calorimeter (DSC) in compliance with JIS K 7121, for example, can be used as the melting point.

There is no problem with the total light transmittance of the holding film layer 30 as long as the indium vapor deposition layer 20 can be visually recognized. be able to. More preferably, the total light transmittance of the holding film layer 30 is 88% or more, so that decorativeness and design similar to those of metal materials can be satisfied. If the total light transmittance is less than 85%, the visibility of the indium deposition layer 20 may deteriorate, and there is a risk that decorativeness and design will not be satisfied. Further, even if the total light transmittance is 100%, there is no problem with transparency. The upper limit of the total light transmittance of the holding film layer 30 is generally about 99%.

As for the haze of the holding film layer 30, there is no problem if the indium deposition layer 20 is visible, but the lower limit of the haze of the holding film layer 30 is generally 0.1%. Moreover, when the haze is more than 80%, the visibility of the indium vapor deposition layer 20 may be lowered due to diffusion of light, and decorativeness and design may not be satisfied.

By controlling the total light transmittance and haze described above and appropriately adjusting the transparency of the holding film layer 30, desired decorativeness and designability can be achieved while satisfying the millimeter wave transmittance of the metallic multilayer film 100. can be given.

When a metallic multilayer film 100 having an indium-deposited holding film layer 70 is used to heat and mold a brightly decorated molded product, the holding film layer 30 has a melting point of 230° C. to 250° C., such as modified polyethylene terephthalate. By using a thermoplastic resin, the heat resistance of the metal-tone multilayer film 100 is improved, and the range of temperatures at which the metal-tone multilayer film 100 can be molded and exhibits plasticity is widened. As a result, the temperature control of the metallic multilayer film 100 becomes easier, the formability improves, and a good yield can be maintained. In the case of modified polyethylene terephthalate having a melting point of less than 230° C., the temperature range from the temperature at which the metal-like multilayer film 100 exhibits moldable plasticity to the time when whitening occurs may be very narrow. The temperature range can be very narrow. The upper limit of the melting point of the modified polyethylene terephthalate used as the holding film layer 30 is generally 250°C.

A thermoplastic resin such as modified polyethylene terephthalate used for the holding film layer 30 may have crystallinity. A thermoplastic resin having crystallinity is suitable for the holding film layer 30 for vapor-depositing indium because it is a thin film, has high thickness accuracy, and has rigidity and slipperiness. Thermoplastic resins that do not have crystallinity soften or harden according to temperature changes. Therefore, when it is used for the holding film layer 30, the indium in the indium deposited layer 20 may migrate due to heating, causing a whitening phenomenon or the like.

In the case of a thermoplastic resin such as modified polyethylene terephthalate, the holding film layer 30 is a film that softens and draws down when heated, and the temperature is between the temperature at which the film recovers from drawdown and the temperature at which it starts to sag due to melting. The difference may be 95°C to 120°C.

Drawdown is a phenomenon in which a film or sheet softens and sags during thermoforming. It is very difficult to mold a metallic multilayer film in a state in which drawdown occurs, and molding in this state may cause tearing or wrinkling of the metallic multilayer film.

When a thermoplastic resin such as modified polyethylene terephthalate is used as the holding film layer 30, if it is heated to, for example, a softening point or higher after drawing down, the thermal motion of the resin molecules becomes intense, causing thermal contraction and tension. become a state. The temperature of the holding film layer 30 in this state is defined as the temperature recovered from the drawdown. When the temperature of the holding film layer 30 recovered from the drawdown rises further, the holding film layer 30 melts and begins to droop. The temperature at which this sagging starts is slightly lower than the melting point of the holding film layer 30, and when the holding film layer 30 reaches the melting point, holes may form, making it difficult to maintain the film shape.

The temperature difference between the temperature at which the holding film layer 30 recovers from drawdown and the temperature at which it begins to sag due to melting is 95° C. to 120° C. When the metal-tone multilayer film 100 is obtained by combining with, etc., the range of temperature at which plasticity capable of forming a glittering decorative molded product is exhibited is widened. As a result, the temperature control of the metallic multilayer film 100 becomes easier, the formability improves, and a good yield can be maintained. That is, when the temperature difference is increased, the range of temperatures at which the metal-like multilayer film 100 can be easily molded is widened, so that it can be easily processed into a brightly decorated molded product.

When the temperature difference is less than 95° C., the temperature range from the temperature at which the metal-tone multilayer film 100 including the indium-deposited holding film layer 70 exhibits moldable plasticity to the point at which the whitening phenomenon or the like occurs becomes narrow. Therefore, there is a possibility that the temperature range in which molding is possible is narrowed, and temperature control and deformation processing become difficult, which may make molding difficult or cause whitening. Although the temperature difference may be larger than 120° C., the upper limit of the temperature difference is 120° C. for the holding film layer 30 .

As the thermoplastic resin, modified polyethylene terephthalate, polyester resin and/or polyolefin resin can be used. Low-density polyethylene resin, polypropylene resin, cyclic olefin resin, or the like can be used as the polyolefin resin. Polypropylene resins include, but are not limited to, homopolymers, block copolymers, random copolymers, and the like. As the thermoplastic resin, acrylic resin, fluororesin, polyurethane resin, copolymers thereof, alloys, and the like can be used.

In particular, a polyester-based resin that has excellent adhesion to the indium deposition layer 20 can be used. In addition, the polyester-based resin can sufficiently impart metallic luster to the indium deposition layer 20, and therefore can satisfy decorativeness and designability equivalent to those of metal materials. In addition, since the polyester-based resin is excellent in handleability, for example, in the case of manufacturing the metallic multilayer film 100 using the holding film layer 30, wrinkles may be generated when the holding film layer 30 and other layers are laminated. can be prevented from occurring. Further, if the polyester-based resin is used, it is possible to prevent the occurrence of unevenness in the indium deposition layer 20 due to excessive elongation of the holding film layer 30 . Usual polyethylene terephthalate resins such as amorphous polyethylene terephthalate (“APET”) resin and modified polyethylene terephthalate (MPET) resin can be used as the polyester resin. Focusing on moldability, a modified polyethylene terephthalate (MPET) resin can be used, particularly in terms of its compatibility with deep-drawn moldings.

Moreover, by using MPET resin as the thermoplastic resin, the metallic luster of the metallic multilayer film 100 provided with the indium-deposited holding film layer 70 is particularly vivid, and the decorativeness and design can be fully satisfied. In the case of manufacturing a bright decorative molded product using the metallic multilayer film 100 having the indium vapor-deposited holding film layer 70, if MPET resin is used, even corners with a very small radius of curvature in the bright decorative molded product , whitening phenomenon, etc. can be prevented.

The MPET resin can be obtained by polymerizing ethylene glycol and terephthalic acid as basic monomers and then dehydrating and condensing them with a modifying monomer to form an ester bond. Examples of modifying monomers include 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, isophthalic acid, and 2,6-naphthalene dicarboxylic acid. In particular, by using neopentyl glycol as a modifying monomer, the melting point is high, and the temperature difference between the temperature at which drawdown is recovered and the temperature at which sagging starts due to melting can be increased, and biaxial stretching treatment can be performed. Since the crystallization of the film is suppressed even when the film is formed, the formability is excellent. Therefore, when the holding film layer 30 is applied to the metallic multilayer film 100, the temperature control of the metallic multilayer film 100 becomes easier, the moldability improves, and a good yield can be maintained. Furthermore, it can have excellent metal vapor deposition properties, light resistance, and chemical resistance, and in particular, the metallic luster of the metallic multilayer film 100 is vivid. In addition, in the case of producing a brightly decorated molded product using the metallic multilayer film 100, it is possible to prevent the occurrence of a whitening phenomenon and the like even at corners with extremely small curvature radii in the brightly decorated molded product. It is easy to make the thickness of the film thinner than the general one. Therefore, it is possible to have the effect of improving productivity and reducing manufacturing costs, and it is also possible to easily impart metallic luster to the surface of a complicated shape, enhancing decorativeness and design. be able to.

The ratio of the modifying monomer can be any ratio so as to impart a modifying effect without impairing the properties of polyethylene terephthalate. For example, by setting the ratio of the entire modifying monomer in MPET to 5 mol % to 50 mol %, it becomes easier to control the temperature of the metallic multilayer film 100 including the indium-deposited holding film layer 70, and the moldability is improved. good yield can be maintained. Also, the mixing ratio of various modifying monomers can be arbitrarily set so that the modification effect can be imparted without impairing the properties of polyethylene terephthalate. For example, as the diol component, ethylene glycol and neopentyl glycol are mixed at a mass ratio of 95:5 to 50:50, and as the carboxylic acid component, terephthalic acid and isophthalic acid are mixed at a mass ratio of 95:5 to 50:50. As a ratio, it can be modified. Also, only neopentyl glycol can be modified. The mixing ratio of the diol component and the carboxylic acid component can be arbitrarily determined so that the number of hydroxyl groups and carboxyl groups are the same.

As the thermoplastic resin that can be used for the holding film layer 30, it is possible to obtain, for example, those in the form of pellets or flakes. Then, the holding film layer 30 can be obtained by biaxially stretching the thermoplastic resin into a film by a calendering method, an extrusion method, or another known method.

The holding film layer 30 may contain additives such as stabilizers, ultraviolet absorbers, lubricants, flame retardants, pigments and dyes in addition to thermoplastic resins.

By reducing the thickness of the holding film layer 30, it is possible to increase the winding length per roll, thereby achieving high productivity and sufficient low cost effects. For example, the thickness of the holding film layer 30 can be 100 μm or less, more preferably 40 μm or less, and even more preferably 25 μm or less, in consideration of higher productivity and lower costs. The lower limit of the thickness of the holding film layer 30 is not particularly limited as long as it is sufficient for holding the indium deposited layer 20 and handling for forming the metallic multilayer film 100 . For example, the thickness of the retention film layer 30 can be 3 μm or more, more preferably 5 μm or more.

(Polyethylene terephthalate resin layer)
In particular, in the case of a metallic multilayer film 100 having an indium-deposited holding film layer 70 used as an emblem material, the holding film layer 30 is preferably a polyethylene terephthalate-based resin layer having a thickness of 5 μm to 50 μm.

Examples of polyethylene terephthalate-based resins include resin compositions containing polyethylene terephthalate as a main component, including APET and MPET described above. A polyethylene terephthalate-based resin layer is a layer formed of such a polyethylene terephthalate-based resin.

The retention film layer 30 may have a sandmatted, etched and/or hairlined surface. These processes may improve the holding effect of the indium deposited layer 20, and can express a desired design such as a matte finish. For example, a desired design can be obtained by performing these processes on the surface of the holding film layer 30 that holds the indium deposited layer 20 .

[Metallic multilayer film 100]
The millimeter wave transmission attenuation of the metallic multilayer film 100 is within -1.0 dB. If the millimeter wave transmission attenuation amount is within -1.0 dB, the millimeter wave band transmittance is extremely excellent. Therefore, for example, when a radio wave emitted by a millimeter-wave radar device body passes through the metallic multilayer film 100, or when the emitted radio wave is reflected by an obstacle and passes through the metallic multilayer film 100, the millimeter wave attenuation can be kept low. As a result, even when the metallic multilayer film 100 is arranged on the irradiation path and the reflection path of the millimeter wave, the detection sensitivity of the millimeter wave radar to radio waves can be maintained at a high level.

Ideally, the upper limit of the millimeter wave transmission attenuation amount is 0 dB, but at present, the upper limit is about -0.2 dB. If the millimeter wave transmission attenuation is lower than -1.0 dB, the radio wave detection sensitivity of the millimeter wave radar will be at a high level when the metallic multilayer film is placed on the millimeter wave irradiation path and reflection path. It may not be possible to maintain

Further, the total light transmittance of the metallic multilayer film 100 is 30% or less. If the total light transmittance is 30% or less, the metallic luster of the metallic multilayer film 100 can be visually recognized, and decorativeness and design can be satisfied. Although it is preferable that the total light transmittance is lower, it may become difficult to satisfy the transmission performance in the millimeter waveband, and the lower limit of the total light transmittance is currently 1.3%.

In addition, if the total light transmittance exceeds 30%, the visibility of the metallic luster is affected, and there is a possibility that the decorativeness and design are not satisfied.

<Base film layer 10>
The base film layer 10 is the bottommost layer of the metallic multilayer film 100, and is resistant to the temperatures used to manufacture bright decorative moldings such as emblems. In addition, when used for glittering decorative moldings that do not require transparency, there is usually no particular requirement for color such as transparency, transparency, and the like. However, the color tone of the base film layer may affect the color tone of the metallic luster on the surface of the glitter decorative molding. In addition, depending on the structure of the bright decorative molding and the backlight, there are cases where light is transmitted through the metal layer to produce decorativeness and design. In this case, the base film layer is also transparent. requested.

As a measure of transparency, total light transmittance and haze are important. If the total light transmittance is 85% or more, light can be transmitted through the indium vapor-deposited layer 20 to produce decorativeness and design, and the total light transmittance is more preferably 88% or more. If the total light transmittance is less than 85%, there is a risk that decorativeness and design will not be satisfied.

Further, there is no problem with the haze as long as the indium deposition layer 20 can satisfy the decorativeness and design, and the lower limit of the haze is generally 0.1%. If the haze is more than 80%, the light is diffused, so that the indium vapor deposition layer 20 is insufficient for transmitting the light, and the decorativeness and design may not be satisfied.

By appropriately adjusting the transparency of the base film layer 10 by controlling the total light transmittance and haze, the metallic multilayer film 100 can achieve desired decorativeness and design while satisfying millimeter wave transmittance. can be given.

As the base film layer 10, polyvinyl chloride, polyolefin, polystyrene, polyacrylic, polyurethane, polyamide, Considering the heat resistance to the temperature when molding into bright decorative moldings from resins such as polycarbonate and acrylonitrile-butadiene-styrene copolymers, compatibility with injection molding resins in insert injection molding, etc. The material for layer 10 can be selected accordingly.

The thickness of the base film layer 10 may be a general thickness for the metallic multilayer film 100, for example, 50 μm to 1000 μm. If the thickness of the base film layer 10 is less than 50 μm, defects such as wrinkles are likely to occur when the base film layer 10 and the indium vapor deposition layer 20 are joined by the first polyurethane-based adhesive layer 50, which will be described later. In addition, the metal-tone multilayer film 100 may be easily broken during the molding process of the glitter decoration molding. On the other hand, if the thickness of the base film layer 10 exceeds 1000 μm, there is a risk that the moldability of the glitter decorative molded product will deteriorate.

(Polycarbonate resin layer)
In particular, in the case of the metallic multilayer film 100 used as the material for the emblem, the base film layer 10 preferably has a thickness of 50 μm to 1000 μm and is a polycarbonate-based resin layer with high injection adhesion.

In addition, as a polycarbonate-based resin, a resin composition whose main component is polycarbonate can be mentioned. Polycarbonate-based resins include those produced from bisphenol A synthesized from bisphenol and acetone by an interfacial polymerization method, transesterification method, pyridine method, etc., and bisphenol A and dicarboxylic acid derivatives such as tere(iso)phthalic acid dichloride. and polyester carbonates obtained by copolymerization with and derivatives of bisphenol A, for example, those obtained by polymerization of tetramethylbisphenol A and the like. A polycarbonate-based resin layer is a layer formed of such a polycarbonate-based resin. As the polycarbonate-based resin layer, a transparent layer or a black layer can be appropriately used.

<Indium deposition holding film 70>
The indium-deposited holding film 70 included in the metal-tone multilayer film 100 is as described in the section [Indium-deposited holding film 70], and the description thereof is omitted here.

<Protective film layer 40>
The protective film layer 40 is the uppermost layer of the metal-tone multilayer film 100, has transparency so that the indium deposition layer 20 can be seen, and can withstand the temperature used when molding a brightly decorated molded product. is.

There is no problem with the total light transmittance of the protective film layer 40 as long as the indium vapor deposition layer 20 can be visually recognized. be able to. More preferably, when the protective film layer 40 has a total light transmittance of 88% or more, it can satisfy the same decorativeness and design as those of the metal material. If the total light transmittance is less than 85%, the visibility of the indium deposition layer 20 may deteriorate, and there is a risk that decorativeness and design will not be satisfied. Further, even if the total light transmittance is 100%, there is no problem with transparency. In addition, the upper limit of the total light transmittance of the protective film layer 40 is generally about 99%.

As for the haze of the protective film layer 40, there is no problem if the indium deposition layer 20 is visible, but the lower limit of the haze of the protective film layer 40 is generally 0.1%. Moreover, when the haze is more than 80%, the visibility of the indium vapor deposition layer 20 may be lowered due to diffusion of light, and decorativeness and design may not be satisfied.

By controlling the total light transmittance and haze described above and appropriately adjusting the transparency of the protective film layer 40, desired decorativeness and designability can be achieved while satisfying millimeter wave transmittance for the metallic multilayer film 100. can be given.

The protective film layer 40 may contain various dyes, pigments, etc. in order to adjust transparency, color tone, etc., and may be dyed with a dye. Furthermore, the protective film layer 40 may be printed in advance as desired. In this case, the protective film layer 40 can be printed on the surface in contact with the outside, but on the surface opposite to the surface in contact with the outside, for example, the surface in contact with the second polyurethane adhesive layer 60 described later. By being printed, the durability of printing can be improved.

Examples of materials for the protective film layer 40 include resins such as polyvinyl chloride-based, polyolefin-based, polystyrene-based, polyacrylic-based, polyurethane-based, polyamide-based, polycarbonate-based, and fluorine-based resins. A material for the protective film layer 40 can be appropriately selected from these resins in consideration of transparency, heat resistance to the temperature at the time of molding, economic efficiency, and the like.

For example, the protective film layer 40 is made of an acrylic resin film such as polymethyl methacrylate (PMMA) as the surface of the glitter decorative molded product in terms of obtaining a molded product with excellent expressiveness and scratch resistance. can be used as In this case, excellent moldability can be obtained in molding a glittering decorative molding. In addition, it becomes unnecessary to provide a hard coat layer on the surface of the brightly decorated molded article after molding, which makes it possible to reduce the cost. Furthermore, even when applied to a molding with a large draw, high scratch resistance can be obtained on the entire surface of the glitter decorative molding.

In addition to the above effects of using an acrylic resin film, if it is desired to impart excellent weather resistance to a molded product at the same time, an alloy film of a fluorine resin and an acrylic resin, or a fluorine resin film This can be addressed by using a two-layer film or the like consisting of a layer and an acrylic resin layer.

However, when such an alloy film is used, the adhesiveness may be inferior, and if high adhesiveness is desired, an alloy film layer of a fluororesin containing a large amount of fluororesin and an acrylic resin may be used. Alternatively, a composite alloy film comprising an alloy film layer of a fluororesin having a low fluororesin content and an acrylic resin can be used. In this composite alloy film, by providing the second polyurethane-based adhesive layer 60 on the side of the alloy film layer of the fluorine-based resin having a low fluorine-based resin component and the acrylic resin, good adhesion of the acrylic resin and fluorine-based adhesive are obtained. The excellent weather resistance of the resin can also be obtained. Moreover, when an acrylic resin film is used as the protective film layer, high scratch resistance can be obtained.

Polycarbonate-based resins are excellent in transparency, heat resistance, impact resistance, and moldability, and can be used as a material for the protective film layer 40 because of their high adhesiveness.

The thickness of the protective film layer 40 is usually preferably 10 μm or more, and more preferably 25 μm or more in consideration of handleability. On the other hand, considering formability, flexibility and economy, the thickness of the protective film layer 40 is preferably 300 μm or less. Generally, a thickness of protective film layer 40 between 75 μm and 125 μm can be used.

(Polycarbonate resin layer)
In particular, in the case of the metallic multilayer film 100 used as the material for the emblem, the protective film layer 40 preferably has a thickness of 50 μm to 200 μm and is a polycarbonate-based resin layer with high injection adhesion.

In addition, as a polycarbonate-based resin, a resin composition whose main component is polycarbonate can be mentioned. Polycarbonate-based resins include those produced from bisphenol A synthesized from bisphenol and acetone by an interfacial polymerization method, transesterification method, pyridine method, etc., and bisphenol A and dicarboxylic acid derivatives such as tere(iso)phthalic acid dichloride. and polyester carbonates obtained by copolymerization with and derivatives of bisphenol A, for example, those obtained by polymerization of tetramethylbisphenol A and the like. A polycarbonate-based resin layer is a layer formed of such a polycarbonate-based resin.

(Polyurethane adhesive layer)
The metallic multilayer film 100 comprises a first polyurethane-based adhesive layer 50 that bonds the base film layer 10 and the indium-deposited layer 20, and a second polyurethane-based adhesive layer 60 that bonds the holding film layer 30 and the protective film layer 40. may be provided (Fig. 1).

(First polyurethane adhesive layer 50)
The first polyurethane-based adhesive layer 50 can be formed by applying a polyurethane-based adhesive to the indium deposited layer 20 and/or the base film layer 10 . The polyurethane-based adhesive has excellent adhesiveness to the indium deposited layer 20 and the base film layer 10, and can satisfy transparency, adhesiveness, and heat resistance that can withstand molding temperatures. Since the total light transmittance and haze as indicators of transparency are as described above, descriptions thereof are omitted. When using a polyurethane-based adhesive, the indium deposition layer 20 and/or the base film may be formed by using an appropriate solvent or as an emulsion by known means such as a gravure coater, a die coater, a reverse coater, a knife coater, and a roll coater. An appropriate amount is applied to the layer 10 and dried if necessary to form the first polyurethane-based adhesive layer 50 .

The thickness of the first polyurethane-based adhesive layer 50 may be a general thickness for the metallic multilayer film 100 . For example, the thickness can be 1 μm to 20 μm, and the thickness can be 2 μm to 8 μm considering adhesiveness, drying time, cost, and the like.

(Second polyurethane adhesive layer 60)
The second polyurethane-based adhesive layer 60 can be formed by applying a polyurethane-based adhesive to the protective film layer 40 and/or the holding film layer 30 . The second polyurethane-based adhesive layer 60 may be colored, and may contain various dyes, pigments and/or dyes in order to adjust the transparency, color tone, etc. of the second polyurethane-based adhesive layer 60, and may contain metal powder. , metal foil powder and/or mica, and the like.

The polyurethane-based adhesive has excellent adhesiveness with the protective film layer 40 and the holding film layer 30, and also has transparency and adhesiveness that allow the indium deposition layer 20 to be visually recognized, heat resistance that can withstand the temperature during molding, and outdoor use. It is possible to satisfy the weather resistance etc. that can withstand the use used in. Since the total light transmittance and haze as indicators of transparency are as described above, descriptions thereof are omitted. When using a polyurethane-based adhesive, it is applied to the protective film layer 40 and/or the holding film layer 30 using a suitable solvent or as an emulsion by known means such as a gravure coater, a reverse coater, a knife coater, and a roll coater. By applying an appropriate amount and drying if necessary, the second polyurethane adhesive layer 60 can be formed.

Also, the thickness of the second polyurethane-based adhesive layer 60 can be a general thickness for the metallic multilayer film 100 . For example, the thickness can be 1 μm to 20 μm, and the thickness can be 2 μm to 8 μm considering adhesiveness, transparency, drying time, cost, and the like.

Examples of polyurethane-based adhesives include two-component curable solution type adhesives, non-solvent type adhesives, and wet-curing type adhesives in which the main agent is polyester polyol or polyether polyol and the curing agent is isocyanate. . These adhesives can be used as appropriate to form a polyurethane-based adhesive layer.

(Other configurations)
The metallic multilayer film 100 may have further configurations in addition to the above configurations. For example, the surfaces of the protective film layer 40 and the base film layer 10 are maintained in a clean state and are prevented from being soiled until a bright decorative molding such as an emblem is manufactured using the metallic multilayer film 100. Therefore, a protective film or the like that can be easily peeled off can be provided on the surfaces of the protective film layer 40 and the base film layer 10 .

Although the metallic multilayer film 100 of the present invention is useful as a material for emblems, it is not limited to this, and a front grill that requires higher performance in terms of millimeter waveband transmittance and visible range reflectance. , door mirrors, headlamp reflectors, rear lamp reflectors, garnishes, and bumper moldings.

[Manufacturing method of indium deposition holding film 70]
The indium deposition layer 20 described above is formed by a so-called vacuum deposition method, and the indium deposition holding film 70 is manufactured. A method for manufacturing the indium-deposited holding film 70 by the vacuum deposition method will be described below with reference to the schematic diagram of the vacuum deposition apparatus 200 shown in FIG.

(Vacuum vapor deposition device 200)
The vacuum deposition apparatus 200 has an upper chamber 220 and a lower chamber 230 separated by a partition wall 210 . In the upper chamber 220, a delivery roll 240 from which the holding film 30a to be vapor-deposited is delivered, a take-up roll 250 from which the vapor-deposited holding film 30b is taken up, and the holding film 30a sent from the delivery roll 240 are cooled. The upper part of the cooling roll 260 is disposed for depositing the vapor-deposited holding film 30b to the take-up roll 250. As shown in FIG. The lower chamber 230 is provided with a lower portion of the cooling roll 260 separated by a partition wall 210 and an evaporation source crucible 270 for containing indium. is generated, and this vapor flow adheres to the surface of the holding film cooled by the cooling roll 260 . The upper chamber 220 and the lower chamber 230 are decompressed by pumps (not shown) through openings 221 and 231, respectively.

In particular, the manufacturing method of the indium vapor-deposited holding film 70 of the present invention requires the following vapor deposition process, measurement process, and control process.

<Vapor deposition process>
In this process, under pressure conditions of 1.33×10 ⁻³ Pa to 1.33×10 ⁻² Pa, the holding film layer along the roll at a temperature of −5° C. to 5° C. is exposed to an indium vapor stream. and forming an indium deposition layer on the holding film layer. In the vacuum deposition apparatus 200, the internal pressure of the lower chamber 230 is controlled to 1.33×10 ^-3 Pa to 1.33×10 ^-2 Pa, and the temperature of the cooling roll 260 is -5°C to 5°C. to control. Then, indium is vaporized from the evaporation source crucible 270 to generate an indium vapor flow in the lower chamber 230 . In this state, the holding film 30a is fed from the supply roll 240 to the cooling roll 260, cooled to −5° C. to 5° C., and further introduced into the lower chamber 230. FIG. The vapor flow of indium adheres to the surface of the holding film 30a that has entered the lower chamber 230, and the indium is cooled to form the indium deposition layer 20. As shown in FIG.

In this step, by controlling the pressure conditions from 2.0×10 ⁻² Pa to 1.33×10 ⁻² Pa, it is possible to more strictly control the vapor deposition of indium, and have a sea-island structure. An indium deposition layer 20 having a more uniform film thickness can be obtained.

<Measurement process>
This step is a step of measuring the total light transmittance of the laminate of the indium vapor-deposited layer and the holding film layer obtained by the vapor deposition process. In the vacuum deposition apparatus 200, the holding film 30b (laminated body of the indium vapor deposition layer 20 and the holding film layer 30) deposited by the vapor deposition process is sent from the cooling roll 260 to the winding roll 250, and the winding roll 250 be wound up. For example, by placing the transmittance measuring device 280 between the cooling roll 260 and the take-up roll 250, the total light transmittance of the holding film 30b can be measured.

<Control process>
This step is a step of controlling the formation rate of the indium deposition layer so that the total light transmittance of the laminate obtained by the measurement step is 1.3% to 30%. In the vacuum deposition apparatus 200, when the total light transmittance of the holding film 30b measured by the transmittance measuring device 280 is 1.3% to 30%, the pressure condition of the lower chamber 230, the temperature of the cooling roll 260, The vacuum vapor deposition apparatus 200 is controlled so that vapor deposition conditions such as the feeding speed for feeding the holding film 30 a to the lower chamber 230 and the temperature of indium in the vapor source crucible 270 can be maintained. On the other hand, when the total light transmittance of the holding film 30b is not 1.3% to 30%, the vapor deposition conditions are appropriately controlled so that the total light transmittance is 1.3% to 30%. . For example, the feeding speed of the holding film 30a can be mainly controlled, and other conditions can be fixed so that the total light transmittance is a predetermined value in the range of 1.3% to 30%. A sensor constantly monitors the total light transmittance so that the thickness of the indium deposited layer can achieve the desired design and effect, and this data can be fed back to control the feed speed.

The upper chamber 220 is operated under pressure conditions of 1.33×10 ⁻² Pa to 1.33×10 ⁻¹ Pa, preferably 6.67×10 ⁻¹ Pa to 4.00×10 ⁻¹ Pa. By controlling the vapor deposition of indium, it becomes possible to more strictly control the vapor deposition of indium, and the indium vapor deposition layer 20 having a sea-island structure and a more uniform film thickness can be obtained.

[Method for producing metallic multilayer film 100]
An example of a method for producing the metallic multilayer film 100 described above will be described below.

(First lamination step)
This step is a step of laminating the indium vapor deposited layer 20 of the indium vapor deposited holding film 70 obtained by the manufacturing method of the indium vapor deposited holding film 70 of the present invention and the base film layer 10 . For example, by applying a polyurethane-based adhesive to the indium-deposited layer 20 and/or the base film layer 10, the indium-deposited layer 20 and the base film layer 10 can be laminated via the first polyurethane-based adhesive layer 50. . Alternatively, the holding film layer 30 and the base film layer 10 may be laminated.

(Second lamination step)
This step is a step of laminating the holding film layer 30 of the indium-deposited holding film 70 and the protective film layer 40 . For example, by applying a polyurethane adhesive to the protective film layer 40 and/or the holding film layer 30, the holding film layer 30 and the protective film layer 40 can be laminated via the second polyurethane adhesive layer 60. . Also, the indium deposition layer 20 and the protective film layer 40 may be laminated.

The order of the first lamination step and the second lamination step is not particularly limited, and the second lamination step may be performed after the first lamination step, or the first lamination step may be performed after the second lamination step. can be done. Further, for example, a mode is also possible in which a polyurethane adhesive is applied to the indium deposition layer 20 and the holding film layer 30, and the base film layer 10 and the protective film layer 40 are laminated at the same time. The steps can be performed simultaneously.

(Other processes)
The method for producing the metallic multilayer film 100 of the present invention may include further steps in addition to the steps described above. For example, a step of laminating an easily peelable protective film or the like on the surface of the protective film layer 40 or the base film layer 10 can be provided. By this process, the surfaces of the protective film layer 40 and the base film layer 10 can be kept clean and can be prevented from being soiled.

[emblem]
The emblem of the present invention is an emblem provided with the metallic multilayer film of the present invention. An example of the emblem manufacturing method of the present invention will be described below with reference to schematic diagrams showing an example of the manufacturing process of the emblem 300 shown in FIG.

<Example of manufacturing method of emblem 300>
A pattern layer 310 is formed by printing on the surface of the protective film layer 40 of the metallic multilayer film 100 of FIG. The printing method is not particularly limited. For example, screen printing may be used when the metallic multilayer film 100 is a sheet film, and gravure printing may be used when the metallic multilayer film 100 is roll-shaped.

After printing the pattern layer 310, the metal-tone multilayer film 100 is preformed into the shape of the emblem 300 (FIG. 5(b)). Next, the excess peripheral portion is trimmed according to the shape of the emblem 300 (FIG. 5(c)). Then, a black polycarbonate-based resin layer 320 is formed by injection molding on the surface of the base film layer 10 of the metallic multilayer film 100 (FIG. 5(d)). In addition, a transparent and colorless polycarbonate resin layer 330 is formed on the surfaces of the protective film layer 40 and pattern layer 310 by injection molding in order to protect these surfaces and improve their appearance (FIG. 5(e)). Furthermore, the surface of the polycarbonate resin layer 330 is coated with acrylic silicone resin clear paint to form a top coat layer 340 having a thickness of 5 μm to 10 μm (FIG. 5(f)), and the emblem 300 is manufactured.

Hereinafter, the present invention will be described more specifically using examples. However, the present invention is by no means limited to the following examples.

[Manufacturing of Indium Vapor Deposited Holding Film 70]
Using the vacuum deposition apparatus 200, the indium deposition layer 20 was deposited on the holding film 30a. First, the holding film 30 a was attached to the delivery roll 240 and connected to the take-up roll 250 via the cooling roll 260 . Next, using a vacuum pump, the pressure in the upper chamber 220 is adjusted to 1.33×10 ⁻² to 1.33×10 ⁻¹ Pa, and the pressure in the lower chamber 230 is adjusted to 1.33×10 ⁻³ to 1.33×10 −3 Pa. .33×10 ⁻² Pa. Then, the indium in the evaporation source crucible 270 in the lower chamber 230 is gradually heated by the high-frequency induction heating coil, and after the indium reaches its evaporation temperature of 2100° C. to 2200° C., the holding film 30a is transferred to the feeding roll 240. It is wound around a take-up roll 250 along a cooling roll 260 cooled from -5° C. to 5° C., and in a lower chamber 230, the holding film 30a is exposed to an indium vapor flow to vapor-deposit indium. An indium deposition layer 20 was formed on the surface.

The indium deposition layer 20 was formed while the holding film 30a was run from the feeding roll 240 to the take-up roll 250 at a constant speed. Further, the total light transmittance of the vapor-deposited holding film 30b was continuously measured by the transmittance measuring device 280 before being wound up on the take-up roll 250, and the total light transmittance of the holding film 30b The traveling speed of the holding film 30a was adjusted so as to obtain a predetermined value in each of 1 to 6 and Comparative Examples 1 to 3.

As the holding film 30a, a polyethylene terephthalate resin film (Teleflex FT-3 manufactured by Teijin Film Solution Co., Ltd.) having a thickness of 25 μm was used.

[Formation of metallic multilayer film 100]
A polyurethane adhesive was applied to the base film layer 10 to adhere the indium deposition layer 20 of the indium deposition holding film 70 to the base film layer 10 . A polyurethane adhesive was applied to the protective film layer 40 to bond the protective film layer 40 to the protective film layer 30 of the indium-deposited holding film 70 . As described above, a metallic multilayer film 100 was formed.

As the base film layer 10, a 125 μm-thick polycarbonate resin film (Shinetech PC11U manufactured by Shine Techno Co., Ltd.) was used. As the protective film layer 40, a 125 μm-thick polycarbonate-based resin film (Shinetech PC11U manufactured by Shine Techno Co., Ltd.) was used. In addition, as the polyurethane adhesive, a mixture of 18 parts by weight of the main agent (Vylon UR1700 manufactured by Toyobo Co., Ltd.), 12 parts by weight of the curing agent (Duranate TPA-100 manufactured by Asahi Kasei Corporation), and 11 parts by weight of ethyl acetate was used. The thickness of each of the polyurethane-based adhesive layer 50 and the second polyurethane-based adhesive layer 60 was set to 2.5 μm.

[Evaluation of sea-island structure]
Using a scanning electron microscope (SEM), an image of the surface of the indium deposition layer 20 is taken in a direction perpendicular to the direction in which indium is deposited. was calculated.

(Number of island portions I)
The number of island portions I (pieces/cm ² ) was calculated by counting the number of island portions I in an SEM image with a magnification of 30,000 and dividing the count by the area of the SEM image.

(Area of island portion I)
Of the island portions I in the SEM image with a magnification of 50,000 times, the island portion I with the largest area and the island portion I with the smallest area were selected visually, and the areas of these island portions I were measured by Tamaya Measurement System Co., Ltd. was measured using a digital planimeter PLANIX5 manufactured by

(Total Peripheral Length of Island Part I)
Using a map measure (kilby meter) manufactured by Myzox Co., Ltd., measure the total extension distance of the sea portion S that is the outer periphery of the island portion I in the SEM image at a magnification of 30,000 times, and divide by the area of the SEM image. The total length (μm/cm ² ) of the perimeter of the island portion I was calculated. In addition, in measuring the total extension distance of the sea portion S, the distance is measured only once for the sea portion S, which is shared by two or more island portions I as an outer circumference because the island portions I are adjacent to each other. not measured.

[Measurement of film thickness of indium deposition layer 20]
A side cross-sectional image of the metallic multilayer film 100 was taken using a scanning electron microscope (SEM). The distance L between the surface 31 of the holding film layer 30 and the surface 21 of the flattened indium particles was measured, and the longest distance L was defined as the film thickness of the indium deposition layer 20 .

[Measurement of total light transmittance]
Using a transmittance meter, the total light transmittance of the metallic multilayer film 100 was measured.

[Measurement of millimeter wave transmission attenuation]
Using KEYCOM's RAS (SM5899), the millimeter wave transmission attenuation of a millimeter wave with a frequency of 76.5 GHz in the metallic multilayer film 100 was measured. The metal-tone multilayer film 100 was set in the apparatus so that millimeter waves would pass from the base film layer 10 to the protective film layer 40 . The measurement was performed 250 times only in one direction from the base film layer 10 to the protective film layer 40, and the average value of the 250 measurements was taken as the millimeter wave transmission attenuation.

[Evaluation of visibility]
The appearance of the metallic multilayer film 100 was visually observed. "○" indicates that there is no problem with the visibility of the metallic luster and the appearance satisfies the decorativeness and design. It was evaluated as "x".

Table 1 shows the evaluation results. SEM images of the surface of the indium deposition layer 20 of the metallic multilayer film 100 in Example 2 and Comparative Example 2 are shown in FIGS. 3 and 6, respectively. In addition, Example 1 is the evaluation result of the indium deposition holding film, and Examples 2 to 6 and Comparative Examples 1 to 3 are the evaluation result of the metallic multilayer film. The metallic multilayer film of Example 2 is a film produced using the indium-deposited holding film of Example 1.

The SEM images of the indium vapor deposited layers of Example 6 and Comparative Example 1 were blurred due to the magnification and resolution of the SEM images. However, even when the SEM image is blurred, the presence of the island portion I and the sea portion S can be recognized by observation of the SEM image, and the island portion I of Example 6 and Comparative Example 1 is It was confirmed that the island portion I was smaller than the island portions I of Nos. 1 to 5, and all were less than 0.01 μm ² . That is, in the indium deposition layers of Example 6 and Comparative Example 1 in Table 1, the number and area of the island portions I, and the total length of the outer circumference were unmeasurable. It was visually confirmed that the number of island portions I was large and the total length of the outer periphery was long.

From the results of Example 1, it was found that the holding film layer had a sea-island indium vapor-deposited layer in which indium was scattered like islands, and the number of island portions I was 150 × 10 ⁶ /cm ² or more. The indium-deposited holding film having a total of 100×10 ⁶ μm/cm ² or more has a millimeter wave transmission attenuation of −1.0 dB or less, a total light transmittance of 1.3% to 30%, and excellent visibility. was also good (Table 1).

The metallic multilayer film of Example 2 using such an indium-deposited holding film of Example 1 exhibited substantially the same millimeter wave transmission attenuation and total light transmittance as those of Example 1 (Table 1). . That is, the base film layer, the protective film layer and the polyurethane adhesive hardly affected the millimeter wave transmission attenuation and the total light transmittance of the indium-deposited holding film.

Further, from the results of Examples 2 to 6, it was found that the holding film layer had a sea-island structure indium vapor deposition layer in which indium was scattered like islands, and the number of island portions I was 150 × 10 ⁶ /cm ² or more, and the outer circumference was A metallic multilayer film using an indium-deposited holding film with a total length of 100×10 ⁶ μm/cm ² or more has a millimeter wave transmission attenuation of −1.0 dB or less and a total light transmittance of was 1.3% to 30%, and the visibility was also good (Table 1).

On the other hand, the metallic multilayer film of Comparative Example 1 has a millimeter wave transmission attenuation amount of -1.0 dB or less, but has a high total light transmittance of 38%, and has a problem in the visibility of the metallic luster. The appearance was unsatisfactory in terms of design.

In the case of Comparative Examples 2 and 3, in the vapor deposition layer of indium, the vapor deposition process progressed integration with the adjacent indium particles to form a continuous layer of indium. The length of the sea portion S surrounding the island portion I was shortened, and the total length of the outer perimeter also decreased. As a result, the continuous layer of indium absorbs millimeter waves, resulting in a reduction in millimeter wave transmission performance.

3 and 6, the indium vapor-deposited layers of Examples 1 and 2 have a sea-island structure in which indium is scattered like islands, while the indium vapor-deposited layer of Comparative Example 2 has a It was confirmed that a continuous layer of indium was formed as a result of integration with adjacent indium particles, making it difficult for millimeter waves to pass through.

[summary]
As described above, according to the present invention, an indium-deposited holding film, a metal-tone multilayer film, and a method for manufacturing an indium-deposited holding film, which can satisfy higher performances in terms of transmittance in the millimeter wave band and reflectance in the visible region. It is clear and industrially useful that a method for producing a metal-like multilayer film and an emblem can be provided.

REFERENCE SIGNS LIST 10 base film layer 20 indium-deposited layer 21 surface 30 retention film layer 30a retention film 30b vapor-deposited retention film 31 surface 40 protective film layer 50 first polyurethane-based adhesive layer 60 second polyurethane-based adhesive layer 70 indium-deposited retention film 100 metal Control multilayer film 200 vacuum deposition device 210 partition wall 220 upper chamber 221 opening 230 lower chamber 231 opening 240 delivery roll 250 take-up roll 260 cooling roll 270 evaporation source crucible 280 transmittance measuring device 300 emblem 310 pattern layer 320 polycarbonate resin layer 330 Polycarbonate resin layer 340 Top coat layer A Region I Island portion L Distance S Sea portion

Claims (9)

an indium deposition layer;
An indium-deposited holding film comprising a holding film layer that holds the indium-deposited layer,
The indium vapor-deposited layer has a sea-island structure in which the holding film layer is dotted with islands of indium,
150×10 ⁶ pieces/cm ² or more of the island-shaped indium are present on the surface of the indium vapor-deposited layer in the direction perpendicular to the direction in which the indium is vapor-deposited;
In the surface, the total length of the outer periphery of the island-shaped indium is 100×10 ⁶ μm/cm ² or more,
The millimeter wave transmission attenuation amount of the indium deposition holding film is within -1.0 dB,
The total light transmittance of the indium-deposited retention film is 1.3% to 30%.
Indium-deposited retention film. 2. The indium-deposited holding film according to claim 1, wherein the area of the island-shaped indium on the surface is 0.01 μm ² to 0.4 μm ² . 3. The indium-deposited holding film according to claim 1, wherein said holding film layer is a polyethylene terephthalate-based resin layer having a thickness of 5 μm to 50 μm. in turn,
a base film layer;
The indium deposition holding film according to any one of claims 1 to 3, comprising an indium deposition layer laminated with the base film layer, and a holding film layer holding the indium deposition layer;
A metallic multilayer film laminated with a protective film layer laminated with the holding film layer,
The millimeter wave transmission attenuation amount of the metallic multilayer film is within -1.0 dB,
The total light transmittance of the metallic multilayer film is 1.3% to 30%.
Metallic multilayer film. The base film layer is a polycarbonate-based resin layer having a thickness of 50 μm to 1000 μm,
5. The metallic multilayer film according to claim 4, wherein the protective film layer is a polycarbonate resin layer having a thickness of 50 μm to 200 μm. a first polyurethane-based adhesive layer that joins the base film layer and the indium deposition layer;
6. The metallic multilayer film according to claim 4, further comprising a second polyurethane-based adhesive layer that bonds the holding film layer and the protective film layer. A method for producing an indium-deposited holding film according to any one of claims 1 to 3,
exposing the retaining film layer along a roll at a temperature of -5°C to 5°C to an indium vapor stream under a pressure condition of 1.33×10 ^-3 Pa to 1.33×10 ^-2 Pa; a vapor deposition step of forming the indium vapor deposition layer on the holding film layer;
a measuring step of measuring the total light transmittance of the laminate of the indium vapor-deposited layer and the holding film layer obtained by the vapor deposition step;
a control step of controlling the formation rate of the indium deposition layer so that the total light transmittance of the laminate obtained by the measurement step is 1.3% to 30%;
A method of making an indium-deposited retention film, comprising: a first lamination step of laminating the indium vapor-deposited layer of the indium vapor-deposited holding film obtained by the manufacturing method of the indium vapor-deposited holding film according to claim 7 and the base film layer;
a second lamination step of laminating the holding film layer of the indium-deposited holding film and the protective film layer;
The method for producing a metallic multilayer film according to any one of claims 4 to 6, comprising An emblem comprising the metallic multilayer film according to any one of claims 4 to 6.

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