JP4376474B2 - Transparent conductive film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transparent conductive film used for a transparent touch panel, a transparent electrode member for an electrochromic element, and the like mounted on various portable terminal devices / OA devices.
[0002]
[Prior art]
Since personal digital assistants (PDAs) and portable information terminals such as sub-notebook computers have a general structure that emphasizes portability and ease of use, they are input on a display device such as a liquid crystal display. A resistive film type transparent touch panel is often used as a device. In some cases, an electrochromic element is disposed on the display for the purpose of adjusting the contrast of the display image in an environment with high illuminance such as when used outdoors.
The touch panel is an insulating microdot spacer formed on a transparent conductive layer using a transparent conductive film having a transparent conductive layer formed on one side and a transparent conductive glass or film having a transparent conductive layer formed on one side as an electrode material. In this case, the transparent conductive layer is opposed to the switch structure, and the input is released by pressing or sliding on the film with a finger or a pen, and is recognized as an XY coordinate.
[0003]
In addition, the electrochromic device includes a transparent conductive film in which a light control layer made of a metal oxide film is formed on a transparent conductive material and another transparent conductive film, and the light control layer and the transparent conductive layer are connected via an electrolyte layer. It is a light control element made to oppose, and it can change an element transmittance | permeability by controlling an absorption coefficient by applying a slight voltage between electrodes.
Touch panels and electrochromic elements placed on the display are as convenient as this, but on the other hand, as the display and other devices become more colored, higher definition, and more diverse, communication, images, brightness, color temperature, contrast There has been a demand for not changing as much as possible.
In other words, the optical characteristics of the touch panel and the electrochromic element in the transparent state are as follows: (1) The transmittance is almost as high as 100%, (2) The reflectance from the outermost surface is as low as possible, (3) There is a demand not only to have high transmittance only at a limited wavelength but also to have little chromatic dispersion of transmittance in the visible region.
[0004]
The display turns white when all three primary colors of red, blue, and green are emitted, but white appears to be white, and it is desired not to be red or blue.
It is desirable that the white color on the display coincides with the white point (X0 = 0.333, Y0 = 0.333) on the CIE (International Lighting Commission) chromaticity coordinates as an object color, or is infinitely close. Here, the object colors of the touch panel arranged on the display or the chromic element in the decolored state represent each object color by CIE chromaticity coordinate values (X1, Y1), which are expressed as white point coordinate values (X0, If the value divided by Y0) is defined as whiteness, whiteness (X1 / X0, Y1 / Y0) is required to be close to 1 for both X1 / X0 and Y1 / Y0.
[0005]
However, the transparent conductive film used for a transparent touch panel or an electrochromic element has reflection due to a difference in refractive index at each interface between the transparent conductive layer and the air layer, and the transparent conductive layer and the electrolyte layer. Further, although a hard coat layer or the like may be formed, reflection due to the difference in refractive index occurs also at the interface between the surface layer and the air layer on the opposite surface of the transparent conductive layer. As a result, there is a problem that the image brightness of the display is lowered, and in the case of a touch panel disposed on the reflective liquid crystal, the efficiency of capturing light from the outside is lowered. In addition, since the transparent conductive layer generally has a refractive index of around 2.0, there is a problem that a relatively large wavelength dispersion occurs in the reflectance in the visible light region, and the whiteness is deteriorated.
[0006]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a transparent conductive film having good optical characteristics, which has high transmittance, low reflectance, and whiteness, which is suitable for touch panels and electrochromic elements.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention first forms a photocurable transparent resin layer on both sides of a transparent film (1) as shown in FIG. 1, and a metal oxide is formed on one transparent resin layer (21). A composite comprising a metal oxide-based transparent conductive layer (2) through an undercoat layer (20) comprising, and containing at least two kinds of metal elements on the other transparent resin layer (11) Provided is a transparent conductive film having a low reflective layer (10) comprising a laminate of a metal oxide layer and a SiO ₂ layer.
[0010]
In order to further improve the adhesion between the transparent resin layer (21) and the undercoat layer (20) and / or between the other transparent resin layer (11) and the low reflective layer (10), silicon is used. A transparent conductive film characterized in that a metal layer made of an alloy of one or more metal elements selected from the group consisting of tin, zinc, nickel, hafnium and zirconium is formed therebetween To do.
[0011]
Moreover, the said transparent resin layer (11) and / or the said transparent resin layer (21) provide the transparent conductive film characterized by having an unevenness | corrugation in the surface which does not contact the said transparent film (1).
Also provided is a transparent conductive film characterized in that a conductive surface is patterned by laser processing in processing.
[0012]
In addition, as an application, a transparent conductive film characterized by being used for an analog touch panel for pen input is provided.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. First, as the transparent film substrate used in the present invention, various plastic films having transparency can be used. Specifically, polyethylene terephthalate (PET), polyethersulfone (PES), polyetheretherketone (PEEK). ), Polycarbonate (PC), polypropylene (PP), polyamide (PA), polyacryl (PAC), norbornene-based thermoplastic transparent resin, or a laminate thereof. As the thickness of the film base, one having a thickness of 20 to 500 μm is usually used.
[0014]
The transparent resin layer is formed on both sides of the transparent film. As the transparent resin, a photocurable silicone resin, acrylic resin, cellulose resin, melamine resin, urethane resin, or the like is used. Usually formed by a coating method, the layer thickness is several μm, and a curing method by heat may be used. The shape may be multi-layered and is generally a flat plate shape, but there are also cases where the resin is mixed and dispersed with silica or an organic resin filler to give unevenness. In the case of a touch panel, even when there is a gap between the transparent conductive layer and the transparent conductive layer facing each other, fine irregularities on the surface act to prevent the generation of Newton rings. The shape is preferably 0.05 to 2 μm and has a maximum height of 0.6 to 3 μm in the evaluation of the center line surface roughness.
[0015]
The low reflection layer (10) is formed on the transparent resin layer (11). In order to reduce the reflectance while ensuring the whiteness, the low-reflection layer (10) is formed by alternately laminating a layer having a large refractive index and a layer having a small refractive index, and the material of the layer, the lamination structure, and the layer thickness. Is set optimally. The low reflection layer (10) of the present invention comprises a laminate of a composite metal oxide layer containing at least two kinds of metal elements and a SiO ₂ layer. The low reflection layer is formed on the transparent resin layer (11), transparent resin layer (11) / composite metal oxide layer (13) / SiO ₂ layer (14), or transparent resin layer (11) / composite metal oxide layer ( 13) / SiO ₂ layer (14) / complex metal oxide layer (15) / SiO ₂ layer (16).
The degree of whiteness is improved by laminating the laminate of the composite metal oxide layer and the SiO ₂ layer. Further, if necessary, an antifouling property can be imparted to the outermost surface by forming a fluoroalkylsilane-based resin layer on the outermost SiO ₂ layer with a thickness of several tens of millimeters by a coating method or a vacuum deposition method. .
[0016]
The composite metal oxide layers (13) and (15) are made of a material selected from the group consisting of silicon, tin, zinc, nickel, hafnium, zirconium, and titanium, and are made of an alloy of these metal elements or a composite oxide. It can be formed by sputtering using a target or pellets, or CVD using a gas. The refractive index of the composite metal oxide layer can be controlled by the composition ratio of the metal element in the target as the starting material and the pellet, or the flow rate ratio of the introduced gas.
[0017]
As for the metal atomic ratio of the composite metal oxide layers (13) and (15), Sn / (Si + Sn) is 40 to 90% in the silicon oxide-tin oxide system, and Zn / (Si) in the zinc oxide-silicon oxide system. + Zn) is 40 to 90%, Ni / (Si + Ni) is 40 to 90% in the nickel oxide-silicon oxide system, and Hf / (Si + Hf) is 40 to 90% in the hafnium oxide-silicon oxide system, Zr / (Si + Zr) is 40 to 90% in the zirconium oxide-silicon oxide system, Zr / (Sn + Zr) is 10 to 80% in the tin oxide-zirconium oxide system, and Sn / (in the tin oxide-zinc oxide system. Zn + Sn) is 20-90%, Ti / (Sn + Ti) is 30-90% in the tin oxide-titanium oxide system, Ti / (Zn + Ti) is 10-90% in the zinc oxide-titanium oxide system, In the zinc oxide-zirconium oxide system, it is preferable that Zr / (Zn + Zr) is selected in the range of 10 to 50% and the refractive index is between 1.6 and 2.3. Yes.
[0018]
The undercoat layer (20) is formed on the transparent resin layer (21). The undercoat layer (20) is formed of a composite metal oxide layer containing at least two kinds of metal elements and an SiO ₂ layer on the transparent resin layer (21) in order to improve the permeability while ensuring the whiteness. a laminated body formed in the configuration of the transparent resin layer (21) / composite metal oxide layer (23) / SiO ₂ layer (24) / transparent conductive layer (2). In order to improve the transmittance by providing layers having different refractive indexes, the transparency is improved when the composite metal oxide layer (23) is formed rather than when the composite metal oxide layer (23) is not formed in the above-described configuration. .
[0019]
The composite metal oxide layer (23) can be formed by using a material selected from the group of silicon, tin, zinc, nickel, hafnium, and zirconium by the same manufacturing method as the composite oxide layers (13) and (15). .
[0020]
As for the metal atomic ratio of the composite metal oxide layer (23), Sn / (Si + Sn) is 10 to 90% in the silicon oxide-tin oxide system, and Zn / (Si + Zn) is in the zinc oxide-silicon oxide system. 10-90%, Ni / (Si + Ni) is 10-90% in nickel oxide-silicon oxide system, Hf / (Si + Hf) is 10-90% in hafnium oxide-silicon oxide system, zirconium oxide-silicon oxide In the system, Zr / (Si + Zr) is preferably selected in the range of 10 to 90%, and the refractive index is preferably in the range of 1.6 to 1.9.
[0021]
The transparent conductive layer (2) is formed on the undercoat layer (20). Although it is a formation method of a transparent conductive film, as a general system for forming a transparent conductive film on a film substrate, a sputtering method, a vacuum deposition method, a PVD method such as an ion plating method, or a CVD method, a coating method, There are printing methods. As the material for forming the transparent conductive film, indium-tin composite oxide (ITO), indium oxide, antimony-added tin oxide, fluorine-added tin oxide, aluminum-added zinc oxide, gallium-added zinc oxide, silicon-added zinc oxide, or oxide Zinc-tin oxide-based, indium oxide-tin oxide-based, zinc oxide-indium oxide-magnesium oxide-based metal oxide, or the like can be used.
[0022]
Single or two or more kinds of metal elements between the transparent resin layer (2) and the undercoat layer (20) and / or between the other transparent resin layer (11) and the low reflection layer (10) When the metal layers (12) and (22) made of the above alloy are formed, the adhesion is increased and the durability is improved. For the metal layers (12) and (22), a metal selected from the group of silicon, tin, zinc, nickel, hafnium, and zirconium is used and formed by a vacuum thinning technique such as sputtering. This is because the layer thickness is preferably in the range of 10 to 50 mm, and if it is thinner than 10 mm, the adhesion effect is small, and if it exceeds 50 mm, the transmittance decreases.
[0023]
【Example】
(Example 1)
An acrylic photocurable transparent resin layer was applied to both sides of a transparent polyethylene terephthalate (PET) having a thickness of 188 μm. Thereafter, a composite metal oxide layer (13) / SiO ₂ layer (14) / composite metal oxide layer (15) / SiO ₂ layer (16) are sequentially formed on one side of the transparent resin layer (11) by sputtering. did. The composite metal oxide layers (13) and (15) were made of a compound of silicon oxide and zirconium oxide, and the ratio of Zr and Si was adjusted so that the refractive index was 1.9.
The composite metal oxide layer (13) was 250 mm, and the composite metal oxide layer (15) was 850 mm. The SiO ₂ layer (14) was 250 mm thick, and the SiO ₂ layer (16) was 900 mm thick.
[0024]
On the other transparent resin layer (21), a composite metal oxide layer (23) / SiO ₂ layer (24) / transparent conductive layer (2) were sequentially formed by sputtering. The composite metal oxide layer (23) was made of a compound of silicon oxide and zirconium oxide, had a thickness of 700 mm, and the ratio of Zr and Si was adjusted so that the refractive index was 1.7. The SiO ₂ layer (24) was 250 Å thick, and the transparent conductive layer (2) was made of indium-tin composite oxide (ITO) with a thickness of 300 Å to form 310 ohm / □.
The total light transmittance of the film was 94.3%, which was good. In addition, the object color measured using an instantaneous multi-photometry system (model number MCPD300) manufactured by Otsuka Electronics Co., Ltd. on a standard white plate is CIE chromaticity coordinates (X = 0.321, Y = 0.325), and white. The degree was good (0.964, 0.976).
[0025]
(Example 2)
Instead of transparent polyethylene terephthalate (PET) having a film thickness of 188 μm used in Example 1, Arton film (“Arton”) manufactured by JSR Corporation, which is a 188 μm-thick norbornene-based thermoplastic transparent resin, is a registered trademark of the company. ) Was used, and everything else was performed in the same manner as in Example 1. As a result, the total light transmittance and the whiteness were almost the same as in Example 1 and were good.
[0026]
(Comparative Example 1)
The same acrylic photocurable transparent resin layer as in Example 1 was applied to both sides of 188 μm thick transparent polyethylene terephthalate (PET). Thereafter, an indium-tin composite oxide (ITO) was formed to a thickness of 300 mm on one side of the transparent resin layer (11) to form 350 ohm / □. This transparent conductive film has a total light transmittance of 87.0%, CIE chromaticity coordinate values measured on a standard white plate (X = 0.305, Y = 0.321), and a total light transmittance as well. The whiteness was also significantly different from the film of Example 1.
[0027]
(Example 3)
A touch panel was prepared by combining the film of Example 1 and glass with fluorine-added tin oxide transparent conductive film (product number PS03) manufactured by Asahi Glass Co., Ltd. This touch panel has a total light transmittance of 89.5%, CIE chromaticity coordinate values measured on a standard white plate (X = 0.328, Y = 0.317), and has both a total light transmittance and a whiteness. It was good.
[0028]
(Example 4)
A touch panel was prepared by combining the film of Example 1 with glass with fluorine-containing tin oxide transparent conductive film (part number PN02) manufactured by Asahi Glass Co., Ltd. This touch panel has a total light transmittance of 88.0%, CIE chromaticity coordinate values measured on a standard white plate (X = 0.316, Y = 0.327), and has both a total light transmittance and a whiteness. It was good.
[0029]
(Comparative Example 2)
A touch panel was produced by combining the film of Comparative Example 1 with the glass with fluorine-added tin oxide transparent conductive film (product number PS03) manufactured by Asahi Glass Co., Ltd. used in Example 3. The CIE chromaticity coordinate values of this touch panel measured on a standard white plate were (X = 0.512, Y = 0.315), and the whiteness was low.
[0030]
(Comparative Example 3)
A touch panel was prepared by combining the film of Comparative Example 1 and the glass with fluorine-added tin oxide transparent conductive film (product number PN02) manufactured by Asahi Glass Co., Ltd. used in Example 4. The CIE chromaticity coordinate values of the touch panel measured on a standard white plate were (X = 0.302, Y = 0.317), and the whiteness was low.
[0031]
(Example 5)
The film of Example 1 was fixed to a moving table, and patterned by irradiating with a YAG laser. The patterning conditions were set to a laser oscillation output of 23 W, a laser oscillation pulse frequency of 3 KHz, and a table moving speed of 1026 mm / S. One pitch movement amount per pulse is calculated from the table moving speed and the laser oscillation pulse frequency, and is 0.342 mm. In this case, the portion with the wide irradiation width is 0.45 mm, but when the distance between the circles which are the narrow portions and the intersection of the circles is calculated, it is about 0.292 mm. When thin line patterning was performed with the table moving distance as a straight line of 30 cm, the conductive surface was within a range of 0.45 mm to 0.41 mm at a wide irradiation width and 0.32 mm to 0.28 mm at a narrow irradiation width. It was peeled continuously. In terms of appearance, there was no bulge or dent exceeding 1 μm caused by melting of the underlying film, and no microcracks were generated on the conductive surface. Electrically, the insulation resistance when DC 25 volts was applied was 100 MΩ or more. Even after 120 hours had passed at a temperature of 60 ° C. and a humidity of 90%, the appearance and insulation resistance did not change and were good.
[0032]
【The invention's effect】
The present invention is implemented in the form as described above, and with the colorization, high definition, and diversification of communication of the display, the touch panel arranged on the display and the electrochromic element in the transparent state are images, luminance, It is possible to meet the requirement that the color temperature and contrast are not changed as much as possible. That is, it is possible to provide a transparent conductive film having high transmittance and low reflectance and good optical characteristics secured in the visible light region.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the basic configuration of the present invention. FIG. 2 (a), (b) is an explanatory diagram showing an example of a low reflection layer. FIG. 3 is an explanatory diagram showing an example of an undercoat layer. FIG. 4 is an explanatory diagram showing an example of a metal layer.
1: Transparent film 2: Transparent conductive layer 10: Low reflection layer 11: Transparent resin layer 12: Metal layer 13: Composite metal oxide layer 14: SiO ₂ layer 15: Composite metal oxide layer 16: SiO ₂ layer 20: Under Coat layer 21: Transparent resin layer 22: Metal layer 23: Composite metal oxide layer 24: SiO ₂ layer

Claims (4)

A material selected from the group consisting of silicon, tin, zinc, nickel, hafnium, and zirconium is formed on one transparent resin layer (21) of the transparent film (1) having a photocurable transparent resin layer formed on both sides. It has a metal oxide transparent conductive layer (2) through the used undercoat layer (20), and on the other transparent resin layer (11), silicon, tin, zinc, nickel, hafnium, zirconium In the transparent conductive film having a low reflective layer (10) composed of a laminate of a composite metal oxide layer containing at least two kinds of metal elements selected from the group of and a SiO ₂ layer ,
A metal comprising an alloy of one or more metal elements selected from the group consisting of silicon, tin, zinc, nickel, hafnium, and zirconium between the transparent resin layer (21) and the undercoat layer (20). A transparent conductive film, wherein a layer (22) is formed. A material selected from the group consisting of silicon, tin, zinc, nickel, hafnium, and zirconium is formed on one transparent resin layer (21) of the transparent film (1) having a photocurable transparent resin layer formed on both sides. It has a metal oxide transparent conductive layer (2) through the used undercoat layer (20), and on the other transparent resin layer (11), silicon, tin, zinc, nickel, hafnium, zirconium In the transparent conductive film having a low reflective layer (10) composed of a laminate of a composite metal oxide layer containing at least two kinds of metal elements selected from the group of and a SiO ₂ layer,
Between the transparent resin layer (11) and the low reflection layer (10), from an alloy of one or more metal elements selected from the group of silicon, tin, zinc, nickel, hafnium, zirconium A transparent conductive film, wherein a metal layer (12) is formed. A material selected from the group consisting of silicon, tin, zinc, nickel, hafnium, and zirconium is formed on one transparent resin layer (21) of the transparent film (1) having a photocurable transparent resin layer formed on both sides. It has a metal oxide transparent conductive layer (2) through the used undercoat layer (20), and on the other transparent resin layer (11), silicon, tin, zinc, nickel, hafnium, zirconium In the transparent conductive film having a low reflective layer (10) composed of a laminate of a composite metal oxide layer containing at least two kinds of metal elements selected from the group of and a SiO ₂ layer,
Between the transparent resin layer (21) and the undercoat layer (20), a metal layer made of silicon alone or an alloy of silicon and a metal element selected from the group consisting of tin, zinc, nickel, hafnium, and zirconium. (22) is formed, The transparent conductive film characterized by the above-mentioned. A material selected from the group consisting of silicon, tin, zinc, nickel, hafnium, and zirconium is formed on one transparent resin layer (21) of the transparent film (1) having a photocurable transparent resin layer formed on both sides. It has a metal oxide transparent conductive layer (2) through the used undercoat layer (20), and on the other transparent resin layer (11), silicon, tin, zinc, nickel, hafnium, zirconium In the transparent conductive film having a low reflective layer (10) composed of a laminate of a composite metal oxide layer containing at least two kinds of metal elements selected from the group of and a SiO ₂ layer,
Between the transparent resin layer (11) and the low reflection layer (10), it is made of silicon alone or an alloy of silicon and a metal element selected from the group consisting of tin, zinc, nickel, hafnium and zirconium. A transparent conductive film, wherein a metal layer (12) is formed.

Images