JP5849566B2 - Substrate with transparent layer - Google Patents

Description

  The present invention relates to a substrate with a transparent layer in which a transparent layer is formed on the substrate.

A substrate with a transparent layer in which a plurality of transparent layers are laminated on a substrate is used for imparting various functions to members such as flat panel displays (liquid crystal displays, electroluminescence displays, plasma displays, touch panels, etc.) and solar cells. It has been.
The functions of the transparent layer include, for example, an electrical function such as a transparent electrode function and an electromagnetic wave shielding function, a physical damage protection function such as scratch prevention and scattering prevention, or antireflection, color correction, ultraviolet ray cut, and infrared ray cut. There are optical functions such as It is important that the transparent layer having such functionality is not visually recognized (invisibility).

In particular, when a transparent layer having a certain function is partially present in the plane of the substrate, the boundary line with or without the transparent layer is seen, and invisibility is hardly achieved. As an example in this case, the case where an electrode function and an electromagnetic wave shielding function are provided by a transparent layer can be mentioned. That is, invisibility is often a problem when the transparent layer is patterned.
The degree of optical transparency of the substrate with a transparent layer is mainly determined by the refractive index and the absorptivity of the transparent layer, the medium of the space, and the functional layer additionally provided in the transparent layer. Therefore, in order to control the transparency, it is conceivable to perform optical design based on the refractive index and the absorptance of the transparent layer, the substrate, the spatial medium, the functional layer, etc., and determine their configuration.

However, since the transparent layer and the medium of the space are determined according to the use of the transparent layer, it is practically impossible to change these constituent materials in order to control the transparency of the substrate with the transparent layer. Therefore, the transparency of the transparent layer is controlled by optical design without changing the material.
For example, the conditions during film formation of the transparent conductive layer are changed so that the transparent conductive layer (transparent layer having a conductive function) has a predetermined refractive index and absorption characteristics based on optical design (for example, See Patent Documents 1 and 2 below). However, when the configuration of the transparent conductive layer itself is changed, there is a problem that both optical characteristics and conductive characteristics change.

  On the other hand, using the optical interference effect, improving the transparency of the entire transparent conductive layer made of a thin film laminate has been studied and implemented (see Patent Document 3 below). In this case, there is no need to change the configuration of the transparent conductive layer itself. Further, according to the invention described in Patent Document 3, it is possible to improve the transparency, but since the manufacturing is complicated, the cost increases.

International Publication WO00 / 063924 Japanese Patent Laid-Open No. 11-48387 JP2009-032548

  An object of the present invention is to provide a substrate with a transparent layer, which is low in production cost and excellent in invisibility of the transparent layer.

In order to solve the above-described problem, the substrate with a transparent layer of the present invention is formed by laminating first and second transparent layers adjacent to each other on at least one surface of the substrate, and the refractive index of the first transparent layer ( The ratio (R2 / R1) of R1) to the refractive index (R2) of the second transparent layer is 0.9 or more and 1.1 or less. Thereby, since the reflection between a 1st transparent layer and a 2nd transparent layer is suppressed, the invisibility of a 1st transparent layer and a 2nd transparent layer becomes favorable.
For the refractive indexes R1 and R2, for example, values at a wavelength of 550 nm are used.
In the substrate with a transparent layer of one embodiment of the present invention, the first transparent layer is a transparent conductive layer having conductivity.
In the substrate with a transparent layer of one embodiment of the present invention, the first transparent layer is patterned. Thereby, the invisibility of the patterned 1st transparent layer becomes favorable.

In the substrate with a transparent layer of one embodiment of the present invention, the transparent conductive layer contains a conductive filler.
In the substrate with a transparent layer of one embodiment of the present invention, the substrate is a plastic film or a glass substrate.
In the substrate with a transparent layer of one embodiment of the present invention, the ratio (R2 / R1) of the average refractive index (R1) of the transparent conductive layer to the average refractive index (R2) of the second transparent layer is 0.9 or more and 1 .1 or less, and the transparent conductive layer is patterned. Thereby, since the reflection between a transparent conductive layer and the 2nd transparent layer adjacent to this is suppressed, the invisibility of the patterned transparent conductive layer becomes favorable.

In the substrate with a transparent layer of one embodiment of the present invention, another substrate is bonded to the surface of the substrate on which the transparent layer is formed and / or the surface on which the transparent layer is not formed.
For example, by attaching a substrate with a transparent conductive layer to another transparent substrate via an adhesive or a pressure-sensitive adhesive, it is possible to add transparent conductivity to a substrate that is usually difficult to form a transparent conductive layer.
The substrate with a transparent layer of the present invention can constitute an electronic device such as a touch panel.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing cost is low and the board | substrate with a transparent layer excellent in the invisibility of the transparent layer is provided.
Since the board | substrate with a transparent layer of this invention is excellent in invisibility, it can be used conveniently for a liquid crystal display, an electroluminescent display, a plasma display, a touch panel, a solar cell, etc. In particular, it can be suitably used as a transparent electrode function and / or an electromagnetic shielding material.

It is sectional drawing which shows an example of the board | substrate with a transparent layer of this invention. It is sectional drawing which shows an example of the board | substrate with a transparent layer of this invention. It is sectional drawing which shows an example of the board | substrate with a transparent layer of this invention. It is sectional drawing which shows an example of the board | substrate with a transparent layer of this invention. It is a schematic block diagram which shows an example of the coating device which can manufacture the board | substrate with a transparent layer of this invention.

Hereinafter, embodiments of the substrate with a transparent layer of the present invention will be described.
In the substrate with a transparent layer shown in FIG. 1, a transparent conductive layer (first transparent layer) 2 and a transparent adjacent layer (second transparent layer) 3 adjacent thereto are provided on one surface of the transparent substrate 1. The transparent conductive layer 2 and the transparent adjacent layer 3 are formed in this order from the substrate 1 side. The ratio of the refractive index of the transparent conductive layer 2 (R1) and the refractive index of the transparent adjacent layer 3 (R 2) (R2 / R1) is 0.9 to 1.1.

In the substrate with a transparent layer shown in FIG. 2, a transparent conductive layer (first transparent layer) 2 and a transparent adjacent layer (second transparent layer) 3 adjacent to the transparent conductive layer (first transparent layer) 3 are formed on one surface of the transparent substrate 1. The transparent conductive layer 2 and the transparent adjacent layer 3 are formed in this order from the substrate 1 side. The ratio of the refractive index of the transparent conductive layer 2 (R1) and the refractive index of the transparent adjacent layer 3 (R 2) (R2 / R1) is 0.9 to 1.1. An antireflection layer 4 is formed on the other surface of the transparent substrate 1.

In the substrate with a transparent layer shown in FIG. 3, a patterned transparent conductive layer (first transparent layer) 21 and a transparent adjacent layer (second transparent layer) adjacent thereto are formed on one surface of the transparent substrate 1. 3 are formed in the order of the transparent conductive layer 21 and the transparent adjacent layer 3 from the substrate 1 side. A part of the transparent adjacent layer 3 is not adjacent to the patterned transparent conductive layer 21 but exists on the substrate 1. That is, in this example, the transparent conductive layer 21 is partially present in the plane of the substrate 1. The ratio (R2 / R1) of the refractive index (R1) of the transparent conductive layer 21 and the refractive index (R 2 ) of the transparent adjacent layer 3 is 0.9 or more and 1.1 or less.

In the substrate with a transparent layer shown in FIG. 4, a patterned transparent conductive layer (first transparent layer) 21 and a transparent adjacent layer (second transparent layer) adjacent thereto are formed on one surface of the transparent substrate 1. 3 are formed in the order of the transparent adjacent layer 3 and the transparent conductive layer 21 from the substrate 1 side. In this example, the transparent conductive layer 21 is partially present in the plane of the substrate 1. The ratio (R2 / R1) of the refractive index (R1) of the transparent conductive layer 21 and the refractive index (R 2 ) of the transparent adjacent layer 3 is 0.9 or more and 1.1 or less.

The second transparent layer (transparent adjacent layer) may be formed by any film forming method such as wet coating or dry coating.
Examples of dry coating include vacuum deposition processes such as vacuum vapor deposition, physical vapor deposition such as sputtering, and plasma CVD. In particular, in order to form a thin film with uniform film quality over a large area, A sputtering method which is stable and the thin film becomes dense is desirable. Particularly preferably, the laminate is continuously formed using a known roll-to-roll method.

  When the second transparent layer is formed by dry coating, the ratio of the refractive index (R1) of the first transparent layer to the refractive index (R2) of the second transparent layer (R2 / R1) is 0. It is appropriately prepared so as to be 9 or more and 1.1 or less. For example, examples of the material having a low refractive index include magnesium oxide, silicon dioxide, magnesium fluoride, calcium fluoride, cerium fluoride, and aluminum fluoride. In addition, examples of the material having a high refractive index include titanium oxide, zirconium oxide, zinc sulfide, tantalum oxide, zinc oxide, indium oxide, niobium oxide, and tantalum oxide. By using one or more of these materials in combination, the refractive index (R2) of the second transparent layer can be adjusted.

When forming a 2nd transparent layer by wet coating, the process of apply | coating a 2nd transparent layer formation coating liquid on a board | substrate, forming a coating film, and drying the coating film and removing a solvent are performed. Further, when the second transparent layer forming material is provided with curability, it includes a step of appropriately curing with a curing method such as heat or ionizing radiation.
When the second transparent layer is formed by wet coating, the ratio (R2 / R1) of the refractive index (R1) of the transparent layer to the refractive index (R2) of the second transparent layer is 0.9 or more and 1.1 or less. As a method for achieving this, there are a method of mixing binders having different refractive indexes, a method of dispersing solid and / or gas particles having different refractive indexes, and the like.

  Examples of the material to be used include a photocurable resin such as a monomer or a crosslinkable oligomer having a trifunctional or higher functional acrylate as a main component. Trifunctional or higher acrylate monomers include trimethylolpropane triacrylate, isocyanuric acid EO-modified triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate , Ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, polyester acrylate and the like. In addition to the above resin, the refractive index (R2) of the second transparent layer can be adjusted by mixing known binders having different refractive indexes.

In addition to the resin, inorganic fine particles such as zirconium oxide, titanium oxide, and hollow silica can be dispersed in the resin to adjust the refractive index of the resin.
The solvent is not particularly limited as long as it dissolves and disperses the resin and the like. Specifically, ethanol, isopropyl alcohol, isobutyl alcohol, benzene, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl Examples include cellosolve acetate and propylene glycol monomethyl ether acetate. These solvents may be used alone or in combination of two or more.

An additive called a surface conditioner may be added to the coating liquid for forming the second transparent layer in order to prevent the occurrence of coating film defects such as so-called repellency and unevenness. Surface modifiers are also called leveling agents, antifoaming agents, interfacial tension modifiers, and surface tension modifiers, depending on their function, all of which work to keep the surface tension of the coating film formed constant or to reduce it. Is provided.
Examples of additives that are usually used as surface conditioners include silicone additives, fluorine additives, acrylic additives, and the like. As the silicone-based additive, a derivative having polydimethylsiloxane as a basic structure and having a modified side chain of the polydimethylsiloxane structure is used. For example, polyether-modified dimethylsiloxane is used as a silicone additive. Further, as the fluorine-based additive, a compound having a perfluoroalkyl group is used.

  In addition to the surface conditioning agent described above, other functional additives may be added to the coating liquid. However, it is preferable that these additives do not impair the transparency of the formed transparent layer. As the functional additive, an ultraviolet absorber, an infrared absorber, a water repellent, an adhesion improver, a stabilizer, and the like can be used, thereby giving the formed second transparent layer a function, Moreover, durability can be improved.

  The coating method on the substrate is dip coating method, spin coating method, flow coating method, spray coating method, roll coating method, gravure roll coating method, air doctor coating method, blade coating method, wire doctor coating method, knife coating method, A reverse coating method, a transfer roll coating method, a bar coating method, a micro gravure coating method, a kiss coating method, a cast coating method, a slot orifice coating method, a calendar coating method, a die coating method, or the like can be used.

  In FIG. 5, the schematic diagram of the coating device was shown as an example. The coating apparatus has a structure in which a die head 50 and a coating liquid tank 52 are connected by a pipe 51, and a coating liquid for forming a transparent layer in the coating liquid tank 52 is fed into the die head 50 by a liquid feeding pump 53. The coating liquid fed to the die head 50 discharges the coating liquid from the slit gap, and a coating film is formed on the substrate 1. By using the roll-type substrate 1 and the rotating roll 55, a coating film can be continuously formed on the substrate by a roll-to-roll method.

The coating liquid is applied, and the coating film formed on the substrate is dried to remove the solvent.
Examples of the drying means include heating, air blowing, and hot air. It is also possible to remove the solvent by natural drying.
When the second transparent layer forming material has thermosetting property, it is cured by applying heat for curing simultaneously with or subsequent to the removal of the solvent and / or separately by applying heat in a subsequent process. Can do.

  When the second transparent layer forming material has ionizing radiation curability, ultraviolet rays and electron beams can be used as the ionizing radiation. In the case of ultraviolet curing, a light source such as a high pressure mercury lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a carbon arc, or a xenon arc can be used. In the case of electron beam curing, electron beams emitted from various electron beam accelerators such as cockloftwald type, bandegraph type, resonant transformer type, insulated core transformer type, linear type, dynamitron type, and high frequency type can be used. . The electron beam preferably has an energy of 50 to 1000 KeV. An electron beam having an energy of 100 to 300 KeV is more preferable.

The film forming method of the first transparent layer may be any film forming method such as wet coating or dry coating, similarly to the method of forming the second transparent layer described above.
Although the function of a 1st transparent layer (transparent functional layer) is not limited, The transparent conductive layer which has electroconductivity is mentioned as an example of a 1st transparent layer.
When the first transparent layer is a transparent conductive layer, the material constituting the transparent conductive layer is indium oxide, zinc oxide, tin oxide, or two or three kinds of mixed oxides thereof, In addition, other additives may be used, and various materials can be used depending on the purpose and application. Although not particularly limited, it is preferable to use indium tin oxide (ITO).

In addition, conductive polymers such as polyacetylene, polydiacetylene, polyaniline, polyparaphenylene, polyparaphenylenevinylene, polythiophene, polyethylenedioxythiophene, polyfuran, polypyrrole, polyphenylene sulfide, polypyridylvinylene, and polyazine can also be used.
As the substrate, a glass substrate, a plastic film, or the like can be used. The plastic film only needs to have appropriate transparency and mechanical strength. For example, polyethylene terephthalate (PET), triacetyl cellulose (TAC), diacetyl cellulose, acetyl cellulose butyrate, polyethylene naphthalate (PEN), cycloolefin polymer, polyimide, polyethersulfone (PES), polymethyl methacrylate (PMMA), A film such as polycarbonate (PC) can be used. Among them, when a hard coat film is provided on the front surface of the liquid crystal display device, triacetyl cellulose (TAC) is preferably used because it has no optical anisotropy, and when not used on the front surface of the liquid crystal display device, polyethylene terephthalate (PET) is used. It is excellent in the balance of mechanical strength, heat resistance, cost, etc., and is preferably used.
Since the board | substrate with a transparent layer of this invention is manufactured by the above, a manufacturing cost becomes low compared with the invention described in patent document 3. FIG.

Examples of the present invention are shown below. In this example, a substrate with a transparent layer having the structure shown in FIG. 3 was produced.
[Example 1]
As the substrate 1, a polyethylene terephthalate (PET) film (“U46” manufactured by Toray Industries, Inc.) having a thickness of 125 μm was used. First, an ITO (refractive index 2.05: indium oxide 90%, tin oxide 10%) film with a thickness of 20 nm was formed on the substrate 1 by a dual magnetron sputtering (DMS) method. The surface resistivity of this ITO film was 450Ω / □.

Next, a resist pattern was applied on the ITO film by screen printing and dried at 100 ° C. for 15 minutes. As a resist, “ARES SPR-081” manufactured by Kansai Paint Co., Ltd. was used. After drying the resist, the substrate 1 was immersed in a 1% by mass hydrochloric acid solution at room temperature for 15 minutes to dissolve the portion of the ITO film where no resist pattern was present.
Next, the substrate 1 was immersed in a 2% by mass aqueous sodium hydroxide solution at room temperature for 5 minutes to peel off the resist pattern. As a result, a patterned transparent conductive layer (ITO film) 21 was formed on the substrate 1.

Next, as the second transparent layer 3, an ultraviolet curable hard coating agent in which titanium oxide is dispersed (“TYT series” manufactured by Toyo Ink Co., Ltd .: refractive index 1.85) is applied by spin coating, and 70 ° C. And dried for 1 minute, and then cured with a high-pressure mercury lamp to form a thickness of 700 nm. In this example, the refractive index ratio (R2 / R1) is 1.85 / 2.05 = 0.90.
The substrate with a transparent layer thus obtained has a patterned transparent conductive layer (ITO film) 21. When confirmed with a three-wavelength fluorescent lamp, the patterned transparent conductive layer (ITO film) 21 is visually recognized. could not.

[Example 2]
As the second transparent layer 3, tin oxide (refractive index: 2.00) was formed with a thickness of 600 nm by a dual magnetron sputtering (DMS) method. Except this, it carried out similarly to Example 1, and obtained the board | substrate with a transparent layer. In this example, the refractive index ratio (R2 / R1) is 2.00 / 2.05 = 0.98.

  The substrate with a transparent layer thus obtained has a patterned transparent conductive layer (ITO film) 21. When confirmed with a three-wavelength fluorescent lamp, the patterned transparent conductive layer (ITO film) 21 is visually recognized. could not.

[Example 3]
As the second transparent layer 3, niobium oxide (refractive index 2.30) was formed with a thickness of 600 nm by a dual magnetron sputtering (DMS) method. Except this, it carried out similarly to Example 1, and obtained the board | substrate with a transparent layer. In this example, the refractive index ratio (R2 / R1) is 2.25 / 2.05 = 1.10.

  The substrate with a transparent layer thus obtained has a patterned transparent conductive layer (ITO film) 21. When confirmed with a three-wavelength fluorescent lamp, the patterned transparent conductive layer (ITO film) 21 is visually recognized. could not.

[Comparative Example 1]
As the second transparent layer 3, an ultraviolet curable hard coating agent in which zirconium oxide was dispersed (“KZ6661” manufactured by JSR Corporation: refractive index 1.65) was applied by spin coating and dried at 70 ° C. for 1 minute. Then, it hardened | cured with the high pressure mercury lamp and formed in thickness 650nm. Except this, it carried out similarly to Example 1, and obtained the board | substrate with a transparent layer. In this example, the refractive index ratio (R2 / R1) is 1.65 / 2.05 = 0.80.
When the substrate with a transparent layer thus obtained was confirmed with a three-wavelength fluorescent lamp, the patterned transparent conductive layer (ITO film) 21 was visible.

[Comparative Example 2]
As the second transparent layer 3, titanium oxide (refractive index: 2.45) was formed with a thickness of 600 nm by a dual magnetron sputtering (DMS) method. Except this, it carried out similarly to Example 1, and obtained the board | substrate with a transparent layer. In this example, the refractive index ratio (R2 / R1) is 2.45 / 2.05 = 1.20.
When the substrate with a transparent layer thus obtained was confirmed with a three-wavelength fluorescent lamp, the patterned transparent conductive layer (ITO film) 21 was visible.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 1st transparent layer 21 1st patterned transparent layer 3 2nd transparent layer 4 Antireflection layer 50 Die head 52 Coating liquid tank 51 Piping 53 Liquid feeding pump 52 Coating liquid tank 55 Rotating roll

Claims (8)

First and second transparent layers adjacent to each other are laminated on at least one surface of the substrate,
The first transparent layer is a transparent conductive layer having conductivity,
The second transparent layer is a layer made of tin oxide or niobium oxide,
With a transparent layer, wherein the ratio (R2 / R1) of the refractive index (R1) of the first transparent layer and the refractive index (R2) of the second transparent layer is 0.9 or more and 1.1 or less substrate.   The substrate with a transparent layer according to claim 1, wherein the first transparent layer is patterned. With a transparent layer substrate according to claim 1, wherein the transparent conductive layer containing a conductive filler.   The substrate with a transparent layer according to claim 1, wherein the substrate is a plastic film or a glass substrate. The ratio (R2 / R1) of the average refractive index (R1) of the transparent conductive layer to the average refractive index (R2) of the second transparent layer is 0.9 or more and 1.1 or less, and the transparent conductive layer is patterned. The substrate with a transparent layer according to claim 3 . With a transparent layer substrate according to any one of claims 1 to 5 which another substrate is bonded to the transparent layer surface and / or the transparent layer is formed it is not formed in the substrate . The electronic device which has a board | substrate with a transparent layer described in any one of Claims 1-6 . The touch panel which has a board | substrate with a transparent layer described in any one of Claims 1-6 .

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