JP2013037040A - Colored product and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a colored product with an optical evaporated multilayer film capable of easily forming black or darkish coloring on the back face of a transparent base material (a base plate), and a manufacturing method thereof.SOLUTION: The colored product includes an optical evaporated multilayer film on the back side of a transparent base material 21 and is colored. The optical evaporated multilayer film includes: a reflectance attenuation film 27 formed of a dielectric material; and a light-absorbing film 25 and a concealing film 29 that are formed on the inside and the outside of the reflectance attenuation film 27 and formed of the same type or different types of metal materials. Generally, a projective film 31 is provided on the outer face side of the concealing film 29.

Description

  The present invention relates to a colored product colored with a deposited optical multilayer film on the back surface of a transparent substrate and a method for producing the same, and is particularly suitable for a dark colored product. Here, a cover body 13 having a transparent window 13a in a personal digital assistant (PDA) 11 as shown in FIG. 1 will be described as an example of the colored product.

  In the present specification and claims, “refractive index” means a value measured at 25 ° C. using a sodium D line.

  In PDA, from the standpoint of reducing the thickness and weight of PDA, for example, development of a design in which a liquid crystal panel 15 is directly attached to the back surface of a cover body 13 formed of a transparent substrate as shown in FIG. Has come to be requested.

  In such a case, it is usually necessary to form a colored frame portion made of the concealed colored layer 17 on the back surface of the peripheral portion of the cover body 13.

  And the coloring in the frame part of the cover body 13 was formed by painting or printing.

  However, in order to secure a hiding power (non-transmissibility) in painting or printing, a hiding colored layer 17 having a thickness of at least 2 to 8 μm is required.

  Therefore, a gap (air layer) 19 of 2 to 8 μm is generated between the back surface of the cover body 13 and the surface of the liquid crystal panel 15 at the display site. The air gap (air layer) 19 is liable to adversely affect the visibility of the display part (for example, image distortion), and when an impact force is applied to the display part of the cover body 13 from the outside, there is a possibility that cracks or the like may occur. There is (particularly when the cover body 13 is formed of a transparent base material having poor impact resistance).

  Therefore, if the concealed colored layer 17A is formed of a vapor-deposited optical multilayer film, it can be considered that the gap of the gap 19A is remarkably reduced as shown in FIG. This is because, in the case of a vapor-deposited optical multilayer film, the total film thickness is usually 100 to 300 nm (0.1 to 0.3 μm), and at most 500 nm (0.5 μm).

  Further, the coloring of the frame portion of the cover body 13 is preferably black or dark, and needs to be concealed without being affected by the background color. However, it has been considered difficult for those skilled in the art to form a color satisfying such a requirement with a vapor-deposited optical multilayer film for the following reasons.

  1) A dark tone can be obtained to a certain extent by forming a vapor-deposited optical multilayer film with a dielectric that is a metal oxide, such as an antireflection film, to reduce the reflectance. However, each dielectric layer forming the vapor-deposited optical multilayer film is basically colorless and transparent, and therefore lacks the back hiding property and is affected by the background color.

  2) Although it is conceivable to combine a metal film in order to improve the concealing property, the metal vapor deposited film basically has a high reflectance, so it becomes metallic (silver color) by reflected light and does not look black.

  Although not affecting the patentability of the present invention, in Patent Document 1, as in the present invention, an optical multi-layer system (deposition optical multi-layer) having a metal layer and a colorless (transparent) dielectric layer as described below is provided. Membranes) have been proposed (see claims, etc.). However, unlike the present invention, it is not planned to be directly vapor-deposited and applied directly to a transparent substrate as a product. A multilayer vapor-deposited film is formed on a peelable support, and after peeling, mainly a pigment As a desirable mode (see paragraphs 0058, 0059, etc.).

"An optical multilayer system comprising a metal layer and a plurality of layers applied on both sides and one side thereof,
(A) (i) a colorless dielectric layer of a material having a refractive index n of 1.8 or less, and (ii) a single layer pack comprising a colorless dielectric layer of a material having a refractive index n exceeding 1.8, and ( B) An optical multilayer system comprising a selective or non-selective absorbing layer, wherein none of the layers (A) and (B) completely surrounds the metal layer. "

JP 2003-131029 A

  In view of the above, the present invention is a colored product provided with a vapor deposition optical multilayer film that has a back surface concealing property and can easily form black or dark color on the back surface of a transparent substrate (substrate). And it aims at providing the manufacturing method.

  As a result of diligent development efforts to solve the above problems (problems), the present inventor has come up with a colored product having the following configuration (see FIG. 3).

A colored product colored with a deposited optical multilayer film on the back surface of the transparent substrate 21,
The deposited optical multilayer film is
A reflectance attenuating film 27 formed of a dielectric material, and a light absorbing film 25 and a concealing film 29 respectively formed of the same or different metal materials are provided inside and outside with the reflectance attenuating film 27 interposed therebetween. It is characterized by that.

  It has been found that the above configuration makes it possible to easily form a dark tone (particularly black) coloration on a transparent substrate with a vapor-deposited optical multilayer film.

  The reason is estimated as follows (see FIG. 3).

  Visible light is absorbed by the light-transmitting light absorbing film 25 formed of a metal material on the back surface of the transparent base material 21 and passes through the reflectance attenuating film 27, so that the color tone is dark (black) tone. Further, visible light that has passed through the reflectance attenuating film 27 is slightly reflected by the concealment film 29, but the reflected light is attenuated by the reflectance attenuating film 27 and is a light absorbing film 25 in front of the reflectance attenuating film. Absorbed in. For this reason, the color tone does not become a metallic tone (silver color), but is absorbed over the entire visible light wavelength range and becomes a black tone. Accordingly, it is possible to form a dark tone or black color with a background hiding property on the back surface of the transparent substrate 21.

  In this way, it is possible to form dark coloration on the transparent substrate by the vapor-deposited optical multilayer film, and the colored product of the present invention can be applied to a see-through window of a PDA or the like to improve the design. Even if liquid crystal or the like is directly attached to the back surface of the cover body, which is a colored product in this way, a gap is hardly formed between the liquid crystal surface and the back surface of the cover body. And cracks at the time of impact) do not occur.

  The reflectivity attenuating film 27 may be a multilayer composed of two or more of a high refractive index dielectric layer and a low refractive index dielectric layer, but has a refractive index of 1.8 or less (preferably 1.5 or less). It is desirable that the low refractive index dielectric layer is a single layer. The lower refractive index relatively increases the light absorption. In addition, the single layer contributes to the thinning of the deposited optical multilayer film (the concealed colored layer).

  In the colored product having the above-described configuration, a single-layer or multi-layer color tone imparting film 23 for imparting a color tone is formed on the inner side of the light absorbing film and in contact with the back surface of the transparent base material. It is desirable to have a configuration. This is because the dielectric material has better adhesion to a transparent substrate (particularly transparent plastic) than the metal material.

  It is desirable that the color tone imparting film 23 is composed of two types, a high refractive index film 23a and a low refractive index film 23b. This is because the degree of freedom of color tone increases.

  In the colored product having the above configuration, it is desirable to form the protective film 31 in contact with the outer surface of the masking film 29. This is for the purpose of preventing oxidation and imparting scratch resistance to the light absorption film formed of a metal material.

The protective film 31 may be of a silicone resin type, but from the viewpoint of improving the work efficiency of the concealed colored layer forming step, silicon oxide or SiO that can be formed with the same apparatus as that for forming the assembled thin film of the interference multilayer film ₂ , It is desirable to form with the vapor deposition film of SiO or those complex oxides. Furthermore, it is desirable that the light absorbing film and the concealing film are made of any metal material of Cr, In, Ni, Fe, Ti, Sn and Al.

  Of these metal materials, Cr is particularly desirable. This is because the film-forming property is excellent and the durability is also excellent. When the light absorbing film and the concealing film are formed of Cr, each film thickness is, for example, a light absorbing film: 3 to 12 nm (desirably 5 to 10 nm), and a concealing film: 50 to 80 nm (desirably 60 to 70 nm). To do.

  In the colored product having each configuration described above, the transparent substrate preferably has a light transmittance of 80% or more (more preferably 90% or more). This is from the viewpoint of the visibility of the non-colored portion.

  The transparent substrate is preferably formed of a polyacrylic (methacrylic) resin, polycarbonate, PET, or a laminate thereof.

  And it is desirable to design a vapor deposition optical multilayer film so that the total reflectance of all the layers containing the said transparent base material of colored products may be 20% or less (desirably 15% or less). Darker coloring becomes easier.

  And the vapor deposition optical multilayer film in each said colored product is formed by physical vapor deposition (PVD). PVD may be any of vacuum vapor deposition (resistance heating or electron beam heating), sputtering, or ion plating, and is appropriately selected depending on the material of the transparent substrate and the vapor deposition film.

It is a top view which shows an example of the cover body of PDA to which this invention is applied. FIG. 2 is a model cross-sectional view of a conventional example (A) and an example of the present invention (B) at the part 2-2 in FIG. It is sectional drawing which shows an example of the film | membrane structure of the vapor deposition optical multilayer film of this invention. It is theory explanatory drawing of the dark tone coloring of this invention.

  As shown in FIG. 3, the film configuration of the vapor deposition optical multilayer film of the present embodiment includes a color tone imparting film 23, a light absorption film 25, a reflectance attenuating film 27, a concealing film 29, and a transparent substrate (substrate) 21. The protective film 31 is formed in contact with each other. Hereinafter, each membrane element will be described.

(1) Transparent substrate 21:
The transparent substrate may be 1) an organic transparent substrate or 2) an inorganic transparent substrate. Usually, the following organic transparent substrate is used from the viewpoint of weight reduction, moldability, workability, and the like. A transparent substrate having a light transmittance (visible average) of 80% or more, desirably 85% or more, and more desirably 90% or more is used. In addition, the numerical value after the material name of an organic transparent base material is a light transmittance and a refractive index (25 degreeC). The form of the transparent substrate is not limited to a plate material or a molded product, and may be a flexible film or sheet. The thickness of the transparent substrate is 50 μm to 10 mm (for example, 0.5 to 1 mm in the case of a PDA cover).

<Organic transparent substrate>
Polymethyl methacrylate (PMMA): 92%, 1.49,
Styrene acrylonitrile (SAN): 90%, 1.57,
Polycarbonate (PC): 89%, 1.58,
Polystyrene (PS): 88%, 1.59
Polyethylene terephthalate (PET): 90%, 1.52
(2) Color tone imparting film 23:
The color tone imparting film 23 is for imparting a color tone (hue) by laminating one set or two or more sets of thin films formed of two or more kinds of dielectric materials.

  In general, the thin film is composed of a high refractive index film 23a and a low refractive index film 23b. As shown in the figure, the high refractive index film 23 a is formed so as to be in contact with the transparent base material 21, but the low refractive index film 23 b may be formed so as to be in contact with the transparent base material 21.

  The number of repetitions of the assembled thin film is 1 or 2. This is because in the present invention, it is desirable to make the concealed colored layer as thin as possible.

  Each film thickness varies depending on the color tone required for the interference multilayer film, and is appropriately set from a range of 50 to 150 nm. Usually, the optical film thickness is set to be λ / 4. It can also be set to λ / 2 and λ / 8 as appropriate.

For example, in the case of a combination of high refractive index film / low refractive index film = ZrO ₂ (n: 2.0) / SiO ₂ (n: 1.5), the color tone is λ (center wavelength) = 460 nm blue In the case of a system, λ / 4 = 125 nm. Then, the film thickness of ZrO ₂ is 74 nm / 2 = 37 nm, and the film thickness of SiO ₂ is 15 nm / 1.5 = 10 nm.

  As the dielectric material for forming the high / low refractive index film, the following materials can be preferably used. Table 1 shows the film formation vacuum degree, the heating temperature, and the refractive index of each dielectric material.

1) Dielectric material with high refractive index Zirconia (ZrO ₂ ), Alumina (Al ₂ O ₃ ), Titania (TiO ₂ ), Tantalum pentoxide (Ta ₂ O ₅ ), Dichromium trioxide (Cr ₂ O ₃ ) Or ITO (Indium Tin oxide)
2) Dielectric material having a low refractive index Silicon dioxide (SiO ₂ ), silicon monoxide (SiO), or a composite oxide thereof.

Of the high-refractive-index film dielectric materials, a high-refractive-index material (for example, ZrO ₂ ) and a low-refractive-index material (Al ₂ O ₃ ) can be combined to form a combined thin film.

（３）光吸収膜２５：
光吸収膜２５は、光吸収性を有する金属材料により形成され、可視光の略全波長域において光吸収作用を発揮し、色調を黒色化（ダーク調化）に寄与するとともに、隠蔽膜からの反射光を吸収して色調がメタリック調（シルバー色）になるのを阻止するものである。

(3) Light absorption film 25:
The light absorption film 25 is formed of a light-absorbing metal material, exhibits a light absorption effect in substantially the entire wavelength range of visible light, contributes to blackening (darkening) the color tone, and from the masking film. It absorbs the reflected light and prevents the color tone from becoming metallic (silver).

  As the metal material having light absorptivity, those shown in Table 2 can be suitably used. Table 2 shows the degree of film formation vacuum, heating temperature, and refractive index of each metal material. Tables 3-1 to 3-5 show the refractive index and absorption coefficient of each metal material at each wavelength of Cr.

そして、この光吸収膜２５の厚さは、金属材料および光吸収膜に要求される光吸収度により異なる。

The thickness of the light absorption film 25 differs depending on the light absorption required for the metal material and the light absorption film.

  For example, when the light absorption film is formed of Cr, the thickness is set to 3 to 12 nm (preferably 5 to 8 nm). When the film thickness of the light absorption film is too thin, it is difficult to sufficiently absorb the metal reflected light from the masking film, and it becomes difficult to obtain a dark toning (particularly black) coloring due to the silver color.

  On the other hand, if the film thickness is too thick, the reflected light of the light absorption film itself is manifested, and it tends to be metallic (silver color).

  If a metal having a large light absorption coefficient, such as Sn, is used, the film thickness of the light absorption film may be relatively thin.

(4) Reflectance attenuation film 27:
Similar to the above, it is formed of a dielectric material, and the dielectric material is desirably a low refractive index dielectric thin film. That is, it is desirable to use the aforementioned low refractive index dielectric material, for example, SiO ₂ , SiO, or a composite oxide thereof. This is because the reflectance is smaller than that of a high refractive index material.

The film thickness of the reflectance attenuating film 27 varies depending on the dielectric material used. For example, when using a dielectric material having a low refractive index (1.8 or less, preferably 1.5 or less) of the above silica-based (SiO ₂ , SiO or a composite oxide thereof), 40 to 130 nm (preferably 60-100 nm). If the film thickness of the reflectivity attenuating film is too thick, cracks are likely to occur, and if it is too thin, the attenuation rate of the reflected light from the concealing film 29 is lowered, and a silver color is likely to occur. That is, it becomes difficult to obtain a dark tone, particularly black.

(5) Concealment film 29:
The shielding film is also formed of the same or different metal as the absorbing thin film. From the viewpoint of the deposition efficiency of the deposited film, it is desirable to use the same kind of metal. The concealment film 29 needs to conceal the background color, and therefore needs to have a predetermined thickness or more. For example, it is 40 to 90 nm (desirably 50 to 70 nm). However, as the thickness of the masking film increases, the metal reflectivity increases, and again, the color becomes silver and it becomes difficult to color in a dark tone.

(4) Protective film 31:
It is not inevitable that the metal forming the masking film has high hardness, sufficient scratch resistance, and is difficult to be oxidized (for example, Ti or Al). However, it is inevitable if the scratch resistance is insufficient or the oxidation resistance is insufficient.

The film thickness of the protective film 31 is preferably as thin as possible within a range that provides a protective action. Although it differs depending on the metal type, in the case of a SiO ₂ film, the thickness is appropriately set from the range of 5 to 150 nm.

  In addition, the protective film 31 can also be formed in a non-colored part from the viewpoint of substrate protection.

  The vapor deposition optical multilayer film is usually one of physical vapor deposition methods (PVD), and is formed by vacuum vapor deposition (resistance heating) capable of forming a film at a low temperature. When the transparent substrate has heat resistance, PVD such as sputtering or ion plating may be used.

  In the case of vacuum deposition, for example, the film formation start vacuum degree is 0.9 mPa, electron beam evaporation, and the substrate temperature during film formation is 60 ± 30 ° C.

  The PDA see-through window molded product (cover body) has been described above as an example, but the colored product of the present invention is similar to the PDA in that various electronic products having an EL lighting display screen, and a store show. Application to windows and the like can also be expected.

  Hereinafter, the present invention will be described more specifically based on examples.

  On the back of the PMMA molded product (22mm x 46mm x 1mmt) (organic transparent base material) for the transparent window of the PDA, with the film thickness design shown in Table 4, a color tone imparting film (2 layers), a light absorbing film (single layer) A reflectance attenuation film (single layer), a concealing film (single layer), and a protective film were sequentially formed by vacuum deposition under the conditions shown in Tables 1 and 2 (see FIG. 3).

こうして製造した成形品（着色製品）は、表示するような各色調のダーク調着色が得られることが確認できた。

It was confirmed that the molded product (colored product) produced in this way was able to obtain dark coloration of each color tone as displayed.

  The technical scope of the present invention covers various aspects within the scope of the claims, and is not limited to the above-described embodiments or examples.

DESCRIPTION OF SYMBOLS 21 Transparent base material 23 Color tone provision film | membrane 25 Light absorption film | membrane 27 Reflectivity attenuating film | membrane 29 Shielding film | membrane 31 Protective film

Claims (10)

A colored product colored with a deposited optical multilayer film on the back surface of the transparent substrate,
The deposited optical multilayer film is
A reflectance attenuating film formed of a dielectric material, and a light absorbing film and a concealing film formed of the same or different metal material inside and outside the reflectance attenuating film.
A colored product characterized by that. The colored product according to claim 1, wherein the reflectance attenuation film is formed of a dielectric material (referred to as a low refractive index dielectric material) having a refractive index (n _D ) of 1.8 or less.   Furthermore, a single-layer or multi-layer color tone imparting thin film for imparting a color tone formed of a dielectric material is provided on the inner side of the light absorption film in contact with the back surface of the transparent substrate. Item 1. A colored product according to item 1.   The colored product according to any one of claims 1 to 3, further comprising a protective film on an outer surface side of the masking film. The reflectance attenuating film and the protective film are formed of SiO ₂ , SiO or a composite oxide thereof, and the light absorption film and the concealing film are any of Cr, In, Ni, Fe, Ti, Sn, and Al. The colored product according to claim 4, wherein the colored product is formed of rim.   6. The colored product according to claim 5, wherein the light absorption film and the masking film are made of Cr, the light absorption film is 3 to 12 nm, and the masking film is 40 to 90 nm.   The colored product according to any one of claims 1 to 6, wherein the transparent substrate has a light transmittance of 80% or more.   The colored product according to claim 7, wherein the transparent base material is a monolayer made of polyacryl (methacrylic) resin, polycarbonate, PET, or a laminate thereof.   The colored product according to any one of claims 1 to 8, wherein the total reflectance of all layers including the transparent substrate is 20% or less.   A method for producing a colored product according to any one of claims 1 to 9, wherein all the layers of the vapor-deposited optical multilayer film are formed by physical vapor deposition (PVD). .

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