Metallic color film

Abstract

To provide a metallic color film with excellent insulating properties. [Solution] A metallic color film comprising a substrate, a color adjustment layer, and a metal layer in that order, wherein the color adjustment layer contains Si, the metal layer contains In or Sn, and the average film thickness of the metal layer is 20-37 nm.

Description

Technical Field

[0001] The present invention relates to a metallic color film. More specifically, the present invention relates to a metallic color film having excellent insulation properties.

Background Art

[0002] Conventionally, decorative members for realizing a specific hue have been developed (for example, Patent Document 1). Patent Document 1 discloses a decorative member including a light reflection layer and a light absorption layer provided on the light reflection layer and containing Si.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the decorative member described in Patent Document 1 has poor insulation properties.

[0005] The present invention has been made in view of such conventional inventions, and an object thereof is to provide a metallic color film having excellent insulation properties.

Means for Solving the Problems

[0006] As a result of intensive studies, the present inventors have found that by providing a color tone adjustment layer containing Si and a metal layer containing In or Sn and having a predetermined average film thickness on a substrate, a metallic color film capable of exhibiting excellent insulation properties can be obtained, and thus completed the present invention. That is, the metallic color film of the present invention for solving the above problems mainly includes the following configurations.

[0007] (1) A metallic color film comprising a substrate, a color adjustment layer, and a metal layer in this order, wherein the color adjustment layer contains Si, the metal layer contains In or Sn, and the average film thickness of the metal layer is 20 to 37 nm.

[0008] With this configuration, the metallic color film has excellent insulating properties.

[0009] (2) The metallic color film according to (1), wherein the average thickness of the color adjustment layer is 2.9 to 100 nm.

[0010] With this configuration, the metallic color film can have any desired color and also has excellent insulating properties.

[0011] (3) The metallic color film according to (1) or (2), wherein a* and b* in the L*a*b* color space of the reflected light of the color adjustment layer on the side opposite to the metal layer satisfy the following formula. (a* 2 +b* 2 ) 1 / 2 ≥ 5

[0012] With this configuration, the metallic color film can have any desired color and also has excellent insulating properties. [Effects of the Invention]

[0013] According to the present invention, a metallic color film having excellent insulating properties can be provided. [Modes for carrying out the invention]

[0014] <Metallic Color Film> A metallic color film according to one embodiment of the present invention is a film comprising a substrate, a color adjustment layer, and a metal layer in that order. The color adjustment layer contains Si. The metal layer contains In or Sn. The average film thickness of the metal layer is 20 to 37 nm. Each of these will be described below.

[0015] (base material) The substrate is not particularly limited. Preferably, the substrate is a highly light-transmitting substrate. For example, the substrate may consist of poly(meth)acrylic acid esters such as polymethyl methacrylate (PMMA), polycarbonate, polyethylene terephthalate (PET), polyethylene, polypropylene, polyvinyl chloride, polyimide, polystyrene, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethylene naphthalate (PEN), cycloolefin polymer (COP), etc.

[0016] The thickness of the substrate is not particularly limited. For example, the thickness of the substrate is preferably 2 μm or more, more preferably 4 μm or more, and even more preferably 12 μm or more. Furthermore, the thickness of the substrate is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 125 μm or less. By having the substrate thickness within the above range, the film can be made lighter and have excellent flexibility.

[0017] The substrate may be one which has been subjected to a desired surface treatment. The surface treatment is not particularly limited. Furthermore, the surface treatment may be applied to the surface of the substrate on which the color adjustment layer is formed and on the surface opposite to the surface on which the color adjustment layer is formed. Surface treatments performed on the surface on which the color adjustment layer is formed include matte finish, satin finish, embossing, hairline finish, and various coatings (fluorine finish to provide stain resistance, hard coat finish to provide scratch resistance, antistatic finish to provide antistatic properties, transfer finish to provide transferability, lift-off finish to create partial design elements, etc.). On the other hand, surface treatments performed on the surface opposite to the surface on which the color adjustment layer is formed include matte finish, satin finish, embossing, hairline finish, and various coatings (fluorine finish to provide stain resistance, hard coat finish to provide scratch resistance, antistatic finish to provide antistatic properties, adhesive finish to provide tackiness, etc.). These surface treatments may be performed individually or in combination of two or more types.

[0018] In addition, the base material may be subjected to various surface treatments. The surface treatment is not particularly limited. For example, the surface treatment may be corona treatment, plasma treatment, ion bombardment treatment, ion implantation treatment, or the like. Thereby, the adhesion of the base material to the layer formed thereon can be improved.

[0019] The base material may be a base material having an anchor layer formed thereon in order to improve the adhesion to the color tone adjustment layer described later. In this case, the base material is composed of a base sheet made of the above material and an anchor layer formed on the base sheet.

[0020] The anchor layer is not particularly limited. For example, the anchor layer may be a raw material having good adhesion to the base sheet and good adhesion to the color tone adjustment layer, such as an acrylic resin, a nitrocellulose resin, a polyurethane resin, a polyester resin, a styrene-maleic acid resin, a chlorinated PP resin, a melamine resin, a urea resin, a vinyl chloride resin, a vinyl acetate resin, a siloxane resin, an epoxy resin, or the like.

[0021] The anchor layer may be provided with a design property by adding a coloring agent or a metallic pigment. For example, by blending a coloring agent, the laminated film is likely to exhibit a more vivid color appearance. The type and content of the coloring agent can be appropriately adjusted according to the desired metallic appearance. In addition, the anchor layer may be provided with functions such as an antistatic effect by blending an antistatic agent or the like.

[0022] The method for forming the anchor layer is not particularly limited. For example, the anchor layer is formed by an anchor layer forming step of forming an anchor layer on the base sheet, and can be formed by a blade coating method, a bar coating method, a gravure coating method, a reverse roll coating method, a die coating method, screen printing, or the like.

[0023] (Color tone adjustment layer) The color adjustment layer is a layer provided on the substrate. This allows the observer to observe the hue of the metal layer from the substrate side and see the hue that has been adjusted by the color adjustment layer.

[0024] The color adjustment layer contains Si. The color adjustment layer consists substantially of Si. The purity of Si in the color adjustment layer is preferably 90% by mass or more, more preferably 95% by mass or more, and may be substantially 100% by mass. By having a Si purity within the above range, the metallic color film tends to exhibit vivid metallic coloration. In this embodiment, the color adjustment layer may contain impurities that are unavoidably present, and it may also contain other components as long as they do not hinder the effects of this embodiment.

[0025] The average film thickness of the color adjustment layer is preferably 2.9 nm or more, and more preferably 3.9 nm or more. Furthermore, the average film thickness of the color adjustment layer is preferably 100 nm or less, more preferably 50 nm or less, even more preferably 40 nm or less, and particularly preferably 30 nm or less. By having the average film thickness of the color adjustment layer within the above range, the metallic color film can easily achieve any color (for example, gold, dark reddish-purple metallic, purple metallic, reddish-purple metallic, bluish-purple metallic, light blue metallic, green metallic, pink metallic, red metallic, blue metallic, brown metallic, etc.). In addition, the metallic color film has excellent insulating properties. In this embodiment, the average film thickness of the color adjustment layer can be measured by quantitative analysis using a calibration curve method with an X-ray fluorescence measuring device (for example, an XRF manufactured by Rigaku Corporation).

[0026] The method for forming the color adjustment layer is not particularly limited. For example, the color adjustment layer can be formed by appropriately using conventionally known techniques such as physical deposition methods like vacuum deposition, sputtering, and ion plating, or chemical deposition methods. Among these, the color adjustment layer in this embodiment is preferably formed by sputtering.

[0027] (metal layer) The metallic layer is a layer provided on the color adjustment layer and contains In or Sn.

[0028] The metal constituting the metal layer contains either In or Sn. This makes the metal layer more likely to form a discontinuous film, and the metallic color film has superior insulating properties. Furthermore, the metallic color film of this embodiment can exhibit any metallic hue. In this embodiment, a "discontinuous film" refers to a film having a structure in which multiple island-like portions are arranged with fine gaps between them.

[0029] When the metal layer contains In, the purity of In is preferably 90% by mass or higher, more preferably 95% by mass or higher, and may be substantially 100% by mass. Having In purity within the above range makes it easier for the metallic color film to develop vivid metallic colors. In this embodiment, the metal layer may contain impurities that are unavoidably present, and other components may be included as long as they do not hinder the effects of this embodiment. Examples of other components include Sn.

[0030] When the metal layer contains Sn, the purity of Sn is preferably 90% by mass or higher, more preferably 95% by mass or higher, and may be substantially 100% by mass. A purity of Sn within the above range makes it easier for the metallic color film to develop vivid metallic colors. In this embodiment, the metal layer may contain impurities that are unavoidably present, and other components may be included as long as they do not hinder the effects of this embodiment. Examples of other components include In.

[0031] The average thickness of the metal layer may be 20 nm or more, preferably 22 nm or more, more preferably 24 nm or more, and even more preferably 26 nm or more. Furthermore, the average thickness of the metal layer may be 37 nm or less, preferably 36 nm or less, and more preferably 35 nm or less. If the average thickness of the metal layer is less than 20 nm, the metallic color film will have poor metallic properties and will not easily produce vivid metallic colors. Also, if the average thickness of the metal layer exceeds 37 nm, the metallic color film will have poor insulating properties. By having the average thickness of the metal layer within the above range, the metallic color film is more likely to produce vivid metallic colors. Furthermore, the metallic color film is more likely to exhibit excellent insulating properties. In this embodiment, the average thickness of the metal layer can be measured by quantitative analysis using a calibration curve method with an X-ray fluorescence analyzer (for example, an XRF manufactured by Rigaku Corporation).

[0032] The method for forming the metal layer is not particularly limited. For example, the metal layer can be formed by appropriately using conventionally known techniques such as physical deposition methods like vacuum deposition, sputtering, and ion plating, or chemical deposition methods.

[0033] The metallic color film of this embodiment may have other layers in addition to the base material, color adjustment layer, and metal layer, as appropriate. These other layers may be, for example, a rust-preventive layer, a scratch-resistant layer, an adhesive layer, and the like.

[0034] • Rust-preventive layer The rust-preventive layer is preferably provided to prevent corrosion of the metal layer and the color adjustment layer. In the metallic color film of this embodiment, the rust-preventive layer is preferably provided on the metal layer.

[0035] The rust-preventive layer is not particularly limited. For example, the rust-preventive layer may be composed of acrylic resin, nitrocellulose resin, polyurethane resin, polyester resin, styrene-maleic acid resin, chlorinated PP resin, melamine resin, urea resin, vinyl chloride resin, vinyl acetate resin, siloxane resin, or epoxy resin. In this case, the rust-preventive layer is preferably formed by a wet coating method.

[0036] The average thickness of the anti-corrosion layer formed by the wet coating method is not particularly limited. For example, the average thickness of the anti-corrosion layer is preferably 20 nm or more, and more preferably 30 nm or more. Furthermore, the average thickness of the anti-corrosion layer is preferably 5 μm or less, and more preferably 2 μm or less. When the average thickness of the anti-corrosion layer is within the above range, the metallic color film is protected from corrosion while easily developing a vivid metallic color. In this embodiment, the average thickness of the anti-corrosion layer can be measured by calculating the optical thickness equivalent value using an ultraviolet-visible-near-infrared spectrophotometer (for example, UV3600, manufactured by Shimadzu Corporation).

[0037] According to this embodiment, the metallic color film is a metallic-looking chromatic film that can exhibit metallic colors. In this embodiment, it is preferable that the metallic color film satisfies the following formula (1) in terms of optical reflectance characteristic values ​​(a* value, b* value) in the L*a*b* color space. This allows the metallic color film of this embodiment to be more clearly distinguished from a metallic-looking achromatic film. Furthermore, the metallic color film has any desired color and excellent insulating properties. (a* 2 +b* 2 ) 1 / 2 ≧ 5 Equation (1)

[0038] The metallic color film of this embodiment can easily achieve any color (for example, gold, dark reddish-purple metallic, purple metallic, reddish-purple metallic, bluish-purple metallic, light blue metallic, green metallic, pink metallic, red metallic, blue metallic, brown metallic, etc.).

[0039] For example, if the metallic color film of this embodiment exhibits a gold-like coloration, it is preferable that a* and b* in the L*a*b* color space of the reflected light of the color adjustment layer on the side opposite to the metal layer satisfy the following conditions (1) to (2). (1) Absolute value of reflection a* < Absolute value of reflection b* (2) Reflectance b* value ≥ 5

[0040] Furthermore, if the metallic color film of this embodiment exhibits a blue metallic color, it is preferable that a* and b* in the L*a*b* color space of the reflected light of the color adjustment layer on the side opposite to the metal layer satisfy the following conditions (3) to (4). (3) Absolute value of reflection a* < Absolute value of reflection b* (4) Reflection b* value ≤ -5

[0041] Furthermore, if the metallic color film of this embodiment exhibits a reddish metallic color, it is preferable that a* and b* in the L*a*b* color space of the reflected light of the color adjustment layer on the side opposite to the metal layer satisfy the following conditions (5) to (6). (5) Absolute value of reflection a* > Absolute value of reflection b* (6) Reflection a* value ≥ 5

[0042] Furthermore, if the metallic color film of this embodiment exhibits a green metallic color, it is preferable that a* and b* in the L*a*b* color space of the reflected light of the color adjustment layer on the side opposite to the metal layer satisfy the following conditions (7) to (8). (7) Absolute value of reflection a* > Absolute value of reflection b* (8) Reflection a* value ≤ -5 [Examples]

[0043] The present invention will be described more specifically below with reference to examples. The present invention is not limited in any way to these examples.

[0044] <Example 1> A substrate (PET film, 50 μm thick) was prepared, and a color adjustment layer made of Si was formed on the substrate by sputtering. The sputtering conditions were as follows: A Si target material (99.9% purity by mass) was used as the target, and the deposition pressure with Ar gas introduced was 0.2 Pa. The average thickness of the resulting color adjustment layer was 4.8 nm. Next, a metallic color film was fabricated by forming a metal layer made of In on the color adjustment layer by vacuum deposition. The vacuum deposition conditions were as follows: In (99.9% purity by mass) was used as the deposition material, and the film was deposited by resistance heating deposition. The deposition pressure was 0.03 Pa. The average thickness of the resulting metal layer was 24 nm.

[0045] <Examples 2-20, Comparative Examples 1-26> A metallic color film was obtained using the same method as in Example 1, except that the average film thickness of the color adjustment layer, the material of the metal layer, and the average film thickness were changed as shown in Table 1. In Table 1, a "-" for the color adjustment layer indicates that the color adjustment layer was not provided.

[0046] [Table 1]

[0047] The metallic color films obtained in Examples 1-20 and Comparative Examples 1-26 were evaluated for their optical properties, visual color, and insulating properties using the following evaluation methods. The results are shown in Table 1.

[0048] <Optical Properties Evaluation> The optical properties (a*, b*, and L* values) and total reflectance (Y value) of the reflected light from the color adjustment layer on the side opposite the metal layer were determined using a UV-Vis-Near Infrared Spectrophotometer (UV3600, Shimadzu Corporation) in the wavelength range of 300 nm to 800 nm. This was done by first measuring the baseline using a standard white plate made of barium sulfate, and then measuring the total reflectance spectrum of each metallic color film. In this process, light was incident from the substrate side, and the reflected light was measured.

[0049] <Visual color evaluation> The color of the metallic color film was observed and evaluated visually from the substrate side.

[0050] <Insulation evaluation> Each metallic color film was cut to a size of 5cm x 5cm to prepare samples. The samples were placed in a microwave oven (RE-T2-W6, manufactured by Sharp Corporation) and treated at 500W for 10 seconds. The insulating properties were then evaluated according to the following evaluation criteria. (Evaluation Criteria) ○: No sparks occurred during processing, and no thermal deformation was observed in the film after processing. ×: Sparks occurred during processing, or thermal deformation was observed in the film after processing.

[0051] As shown in Table 1, the metallic color films of Examples 1 to 20 of the present invention exhibit vivid metallic colors and excellent insulating properties.

Claims

1. The substrate, the color adjustment layer, and the metal layer are provided in this order. The aforementioned color adjustment layer contains Si, The aforementioned metal layer comprises In or Sn, The average thickness of the metal layer is 20 to 37 nm. A metallic color film in which a* and b* in the L*a*b* color space of the reflected light of the color adjustment layer on the side opposite to the metal layer satisfies the following formula. (a* 2 + b* 2 ) 1 / 2 ≧ 14.1

2. The metallic color film according to claim 1, wherein the average film thickness of the color adjustment layer is 2.9 to 100 nm.

Images