JP2016091455A - Transparent conductor and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductor in which a sensing pattern as well as a transparent conductive layer remaining in a non-conductive part can hardly be visually recognized.SOLUTION: There is provided a transparent conductor 100 including a transparent substrate 10, transparent conductive layer 16, and an optical adjustment layer 11 between the transparent substrate 10 and transparent conductive layer 16. The optical adjustment layer 11 has a first optical adjustment layer 13, second optical adjustment layer 14, and third optical adjustment layer 15 from the transparent substrate 10 side, and when the refractive indices of the first optical adjustment layer 13, second optical adjustment layer 14, and third optical adjustment layer 15 are n1, n2, and n3, respectively, the following formulas (1), (2), and (3) are satisfied. (1) 1.7≤n3≤2.2, (2) n3-n2≥0.1, and (3) n1-n2≥0.1.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a transparent conductor and a touch panel using the same.

  Transparent electrodes are used in display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescence panel (organic EL, inorganic EL), a touch panel, and an electrochromic element. Such a transparent electrode is normally comprised by the transparent conductor which has a base material and the transparent conductive layer produced on the base material. The transparent conductor can also be used as a transparent electromagnetic wave shielding film.

  A touch panel (also referred to as a touch switch or a flat switch) is an information input device disposed on a display surface such as a liquid crystal device. Touch panels are widely used in electronic devices such as smartphones, car navigation systems, personal computers, ticket vending machines, and bank ATM terminals.

  The touch panel can detect the position when a finger, a touch pen, or the like touches or approaches the instruction image displayed in the image display area. Thus, the information corresponding to the instruction image can be input. There are several methods for detecting the position of the touch panel, and among them, a resistive film method and a capacitance method are mainly used.

  In the case of the capacitance method, the transparent conductive layer of the transparent conductor is processed into a predetermined sensing pattern by etching for sensing. That is, the conductive part which has a transparent conductive layer, and the non-conductive part which does not have a transparent conductive layer are formed in the transparent conductor used for a touch panel by an etching. Therefore, in the projected capacitive touch panel, there is an inherent situation that a sensing pattern is easily recognized due to a difference in optical characteristics between the conductive part and the non-conductive part (for example, Patent Document 1).

JP 2010-15861 A

  When processing into a sensing pattern, whether or not etching has been performed can be determined based on whether or not the etched portion has conductivity. However, in the determination based on the presence or absence of conductivity, it may be determined that there is no transparent conductive layer even if a small amount of the transparent conductive layer remains in the etched portion. The reason for this determination is that the transparent conductive layer may remain in an island shape. When the transparent conductive layer remains in an island shape, the nonconductive portion does not have conductivity. However, since the reflectance is different between the portion where the transparent conductive layer remains and the portion where the transparent conductive layer does not remain, there arises a problem that the transparent conductive layer remaining in an island shape is easily visually recognized. Therefore, it is necessary to completely remove the transparent conductive layer by etching so that the island-shaped transparent conductive layer does not remain in the non-conductive portion.

  However, the etching rate of a normal transparent conductive layer such as ITO varies greatly depending on the crystallinity caused by the difference in crystal grain size. For example, since the crystallinity of the transparent conductive layer changes due to a slight difference in the film formation conditions of the transparent conductive layer, the etching time required to completely remove the transparent conductive layer also changes. In order to make it difficult to recognize a minute amount of the transparent conductive layer remaining in the non-conductive portion, it is necessary to lengthen the etching time of the transparent conductive layer in consideration of a change in film forming conditions. However, when the etching time is lengthened, productivity is lowered. Note that Patent Document 1 does not show any problem or the like when a trace amount of the conductive layer remains in the non-conductive portion, and does not show any solution. For this reason, even when the etching conditions vary somewhat and a small amount of the transparent conductive layer remains in the non-conductive portion, a technique that makes it difficult to visually recognize the transparent conductive layer itself and the sensing pattern remaining in the non-conductive portion. There is a need to establish.

  The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a transparent conductor in which not only a sensing pattern but also a transparent conductive layer remaining in a non-conductive portion is hardly visible. Moreover, it is an object of the present disclosure to provide a touch panel in which not only a sensing pattern but also a transparent conductive layer remaining in a non-conductive portion is hardly visible by using the transparent conductor as described above.

In the present disclosure, a transparent conductor including a transparent substrate, a transparent conductive layer, and an optical adjustment layer between the transparent substrate and the transparent conductive layer, the optical adjustment layer from the transparent substrate side, 1 optical adjustment layer, second optical adjustment layer, and third optical adjustment layer, and the refractive indexes of the first optical adjustment layer, the second optical adjustment layer, and the third optical adjustment layer, respectively. , N1, n2 and n3, a transparent conductor satisfying the following formula (1), formula (2) and formula (3) is provided.
1.7 ≦ n3 ≦ 2.2 (1)
n3-n2 ≧ 0.1 (2)
n1-n2 ≧ 0.1 (3)

  The transparent conductor of this indication is provided with the optical adjustment layer which has the 1st optical adjustment layer, the 2nd optical adjustment layer, and the 3rd optical adjustment layer from the transparent substrate side. By having the third optical adjustment layer satisfying the formula (1) between the second optical adjustment layer and the transparent conductive layer, the difference in refractive index between the transparent conductive layer and the third optical adjustment layer is sufficiently increased. Can be small. Moreover, in addition to the said Formula (1), since Formula (2) and Formula (3) are satisfy | filled, it can be made difficult to visually recognize the trace amount transparent conductive layer which remains in a nonelectroconductive part after an etching.

  Moreover, by satisfy | filling Formula (2) and (3), the difference in the reflectance of an electroconductive part and a nonelectroconductive part is reduced, and it can make it difficult to visually recognize a sensing pattern.

  In some embodiments, it is preferable that the third optical adjustment layer contains silicon nitride or silicon nitride and silicon oxide, and the transparent conductive layer contains indium oxide. Thereby, the difference in refractive index between the third optical adjustment layer and the transparent conductor can be further reduced. Therefore, it is possible to make the trace amount of the transparent conductive layer remaining in the non-conductive portion after etching more difficult to visually recognize.

  In some embodiments, the third optical adjustment layer preferably has a thickness of 2-15 nm. As a result, not only the sensing pattern, but also a small amount of the transparent conductive layer remaining after etching can be made more difficult to visually recognize.

In some embodiments, the transparent conductive layer preferably has a thickness of 10-30 nm. Thereby, the resistance value can be stabilized and the total light transmittance can be increased. In some other embodiments, it is preferable to satisfy the following formula (4) when the refractive index of the transparent conductive layer is n4. As a result, it is possible to make it difficult to visually recognize a minute amount of the transparent conductive layer remaining in the non-conductive portion after etching.
−0.3 ≦ n4-n3 ≦ 0.3 (4)

  In this indication, it is a touch panel which has a sensor film on a panel board, and a sensor film is provided with the above-mentioned transparent conductor. Since such a touch panel has the above-described transparent conductor as a sensor film, not only the sensing pattern but also a small amount of the transparent conductive layer remaining after etching can be hardly visually recognized.

  According to the present disclosure, it is possible to provide a transparent conductor in which not only a sensing pattern but also a transparent conductive layer remaining in a non-conductive portion is hardly visually recognized. In addition, in the present disclosure, by using the transparent conductor as described above, it is possible to provide a touch panel in which not only the sensing pattern but also the transparent conductive layer remaining in the non-conductive portion is hardly visually recognized.

FIG. 1 is a cross-sectional view schematically showing one embodiment of a transparent conductor. FIG. 2 is a photograph of a scanning electron microscope image (magnified at 30,000) showing an enlarged non-conductive portion after etching. FIG. 3 is a schematic cross-sectional view showing an enlarged part of the cross section of the touch panel. 4 (A) and 4 (B) are plan views of a sensor film constituting the touch panel. FIG. 5 is a cross-sectional view schematically showing another embodiment of the transparent conductor of the present invention.

  Preferred embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted in some cases.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of a transparent conductor. The transparent conductor 100 includes a film-like transparent substrate 10 and a transparent conductive layer 16, and an optical adjustment layer 11 including a plurality of layers having different compositions between the transparent substrate 10 and the transparent conductive layer 16. The optical adjustment layer 11 has a structure in which a first optical adjustment layer 13, a second optical adjustment layer 14, and a third optical adjustment layer 15 are laminated from the transparent substrate 10 toward the transparent conductive layer 16. .

(Transparent substrate 10)
The transparent substrate 10 is, for example, a flexible organic resin film or organic resin sheet. “Transparent” in the present specification means that visible light is transmitted, and the light may be scattered to some extent. Regarding the degree of light scattering, the required level varies depending on the use of the transparent conductor 100. What has light scattering generally referred to as translucent is also included in the concept of “transparency” in this specification. The degree of light scattering is preferably small, and the transparency is preferably high. The total light transmittance of the entire transparent conductor 100 is, for example, 86% or more, and preferably 89% or more.

  As the transparent substrate 10, an organic resin film having flexibility is suitable. Examples of the resin film include polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films such as polyethylene and polypropylene, polycarbonate films, acrylic films, norbornene films, polyarylate films, polyether sulfone films, A diacetyl cellulose film, a triacetyl cellulose film, etc. are mentioned. Of these, polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are preferable.

  The transparent substrate 10 is preferably thicker from the viewpoint of rigidity. On the other hand, the transparent substrate 10 is preferably thin from the viewpoint of thinning the transparent conductor 100. From such a viewpoint, the thickness of the transparent substrate 10 is, for example, 10 to 130 μm. The refractive index of the transparent substrate is, for example, 1.50 to 1.70 from the viewpoint of making a transparent conductor excellent in optical characteristics. The refractive index in this specification is a value measured under the conditions of λ = 633 nm and a temperature of 20 ° C.

  The transparent substrate 10 may be subjected to at least one surface treatment selected from the group consisting of corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, and ozone treatment. .

  The thickness of each layer constituting the transparent conductor 100 can be measured by the following procedure. The transparent conductor 100 is cut by a focused ion beam device (FIB, Focused Ion Beam) to obtain a cross section. The cross section is observed using a transmission electron microscope (TEM), and the thickness of each layer is measured. The measurement is preferably performed at 10 or more arbitrarily selected positions, and the average value is obtained. As a method for obtaining the cross section, a microtome may be used as an apparatus other than the focused ion beam apparatus. A scanning electron microscope (SEM) may be used as a method for measuring the thickness. It is also possible to measure the film thickness using a fluorescent X-ray apparatus.

  On the transparent substrate 10, an optical adjustment layer 11 composed of a plurality of layers having different compositions is laminated. The optical adjustment layer 11 is provided with a first optical adjustment layer 13, a second optical adjustment layer 14, and a third optical adjustment layer 15 in this order from the transparent substrate 10 side. The optical adjustment layer 11, that is, the first optical adjustment layer 13, the second optical adjustment layer 14, and the third optical adjustment layer 15 reduce the reflectance of the surface of the transparent conductive layer 16 due to optical interference, and reduce the total light. A layer for increasing the transmittance is formed. In addition, the first optical adjustment layer 13, the second optical adjustment layer 14, and the third optical adjustment layer 15 suppress optical differences due to the presence or absence of the transparent conductive layer 16. The optical adjustment layer 11 has a function of making it difficult to recognize the transparent conductive layer and the sensing pattern remaining in the non-conductive portion, and also has a function of improving the visibility of displayed images and the like.

The first optical adjustment layer 13, the second optical adjustment layer 14, and the third optical adjustment layer 15 satisfy the following relational expressions (1), (2), and (3). In the formulas (1), (2), and (3), n1, n2, and n3 represent the refractive indexes of the first optical adjustment layer 13, the second optical adjustment layer 14, and the third optical adjustment layer 15, respectively. Show.
1.7 ≦ n3 ≦ 2.2 (1)
n3-n2 ≧ 0.1 (2)
n1-n2 ≧ 0.1 (3)

  Since the third optical adjustment layer 15 satisfies the expression (1), the difference in refractive index between the transparent conductive layer 16 and the third optical adjustment layer 15 can be sufficiently reduced. Therefore, it is possible to make it difficult to visually recognize a small amount of the transparent conductive layer remaining in the non-conductive portion. From the same viewpoint, the lower limit of n3 is preferably 1.8. From the same viewpoint, the upper limit of n3 is preferably 2.1.

  n3 and n2 satisfy the relationship of Expression (2). Thereby, the difference in reflectance between the conductive portion and the non-conductive portion is reduced, and the sensing pattern can be made difficult to visually recognize. From the viewpoint of making the sensing pattern more difficult to visually recognize, the lower limit of n3-n2 is preferably 0.2, and more preferably 0.3. Although there is no restriction | limiting in particular in the upper limit of n3-n2, when this refractive index difference becomes large, since a reflectance will become high, it exists in the tendency for the transmittance | permeability to fall. From such a viewpoint, the upper limit of n3-n2 may be 0.7 or 0.6, for example.

  n1 and n2 satisfy the relationship of Expression (3). Thereby, the difference in reflectance between the conductive portion and the non-conductive portion is reduced, and the sensing pattern can be made difficult to visually recognize. The lower limit of n1-n2 is preferably 0.2 from the viewpoint of making it difficult to visually recognize a trace amount of the transparent conductive layer 16 remaining after etching. Although there is no restriction | limiting in particular in the upper limit of n1-n2, When this refractive index difference becomes large, since a reflectance will become high, it exists in the tendency for the transmittance | permeability to fall. From such a viewpoint, the upper limit of n1-n2 may be 0.8 or 0.5, for example.

n1, n2, and n3 preferably satisfy the following formula (5). Thereby, it is possible to further make it difficult to visually recognize a small amount of the transparent conductive layer remaining in the non-conductive portion after the etching.
n3>n1> n2 (5)

(First optical adjustment layer 13)
The first optical adjustment layer 13 contains, for example, a cured resin obtained by curing the resin composition with energy rays. The resin composition preferably contains at least one selected from a thermosetting resin composition, an ultraviolet curable resin composition, and an electron beam curable resin composition. The thermosetting resin composition may include at least one selected from an epoxy resin, a phenoxy resin, and a melamine resin.

  A resin composition is a composition containing the sclerosing | hardenable compound which has energy-beam reactive groups, such as a (meth) acryloyl group and a vinyl group, for example. Note that the notation of (meth) acryloyl group includes at least one of acryloyl group and methacryloyl group. The curable compound preferably contains a polyfunctional monomer or oligomer containing 2 or more, preferably 3 or more energy ray reactive groups in one molecule.

  The curable compound preferably contains an acrylic monomer. Specific examples of acrylic monomers include 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, ethylene oxide-modified bisphenol A di (meth) acrylate, and trimethylolpropane tri (meth). Acrylate, trimethylolpropane ethylene oxide modified tri (meth) acrylate, trimethylolpropane propylene oxide modified tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) Acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate, and 3- (meth) acryloyloxy Riserinmono (meth) acrylate. However, it is not necessarily limited to these. For example, urethane-modified acrylate and epoxy-modified acrylate are also included.

  As the curable compound, a compound having a vinyl group may be used. Examples of the compound having a vinyl group include ethylene glycol divinyl ether, pentaerythritol divinyl ether, 1,6-hexanediol divinyl ether, trimethylolpropane divinyl ether, ethylene oxide-modified hydroquinone divinyl ether, ethylene oxide-modified bisphenol A divinyl ether, Examples include pentaerythritol trivinyl ether, dipentaerythritol hexavinyl ether, and ditrimethylolpropane polyvinyl ether. However, it is not necessarily limited to these.

  The resin composition contains a photopolymerization initiator when the curable compound is cured by ultraviolet rays. Various photopolymerization initiators can be used. For example, it may be appropriately selected from known compounds such as acetophenone, benzoin, benzophenone, and thioxanthone. More specifically, Darocur 1173, Irgacure 651, Irgacure 184, Irgacure 907 (above trade name, manufactured by Ciba Specialty Chemicals) and KAYACURE DETX-S (trade name, manufactured by Nippon Kayaku Co., Ltd.) can be mentioned. .

  The photopolymerization initiator may be about 0.01 to 20% by weight or about 0.5 to 5% by weight with respect to the weight of the curable compound. The resin composition may be a known composition obtained by adding a photopolymerization initiator to an acrylic monomer. Examples of the acrylic monomer added with a photopolymerization initiator include SD-318 (trade name, manufactured by Dainippon Ink & Chemicals, Inc.) and XNR5535 (trade name, Nagase Sangyo), which are ultraviolet curable resins. Etc.).

  When a resin composition that cures with energy rays is used, the resin composition can be cured by irradiation with energy rays such as ultraviolet rays. Accordingly, it is preferable to use such a resin composition from the viewpoint of the manufacturing process.

The resin composition may contain metal oxide fine particles. Examples of the metal oxide fine particles include titanium oxide (TiO ₂ , refractive index: 2.35), zirconium oxide (ZrO ₂ , refractive index: 2.05), cerium oxide (CeO ₂ , refractive index: 2.30), Niobium oxide (Nb ₂ O ₃ , refractive index: 2.15), antimony oxide (Sb ₂ O ₃ , refractive index: 2.10), tantalum oxide (Ta ₂ O ₅ , refractive index: 2.10), and these And a combination of two or more.

  A resin composition in which such fine particles are dispersed in a curable compound is applied onto the transparent substrate 10 and cured to thereby cure the first optical adjustment layer 13 containing a cured resin and fine metal oxide particles. Can also be produced. The fine particles may be, for example, 5 to 500 parts by weight or 20 to 200 parts by weight with respect to 100 parts by weight of the curable compound. As the content of the fine particles decreases, the refractive index of the first optical adjustment layer 13 tends to decrease.

  The average particle diameter of the fine particles is smaller than the thickness of the first optical adjustment layer 13, and may be 100 nm or less or 20 nm or less from the viewpoint of ensuring sufficient transparency. On the other hand, the average particle diameter of the fine particles may be 5 nm or more, or 10 nm or more from the viewpoint of production of the colloidal solution. When organic fine particles and / or inorganic fine particles are used, the total amount of organic fine particles and inorganic fine particles may be, for example, 5 to 500 parts by weight or 20 to 200 parts by weight with respect to 100 parts by weight of the curable compound. May be.

  The first optical adjustment layer 13 is a resin composition solution or a dispersion liquid in which fine particles are dispersed in a resin composition, which is applied onto one surface of the transparent substrate 10 and dried to cure the resin composition. Can be produced. Application | coating in this case can be performed by a well-known method. Examples of the coating method include an extrusion nozzle method, a blade method, a knife method, a bar coating method, a kiss coating method, a kiss reverse method, a gravure roll method, a dip method, a reverse roll method, a direct roll method, a curtain method, and a squeeze method. Etc.

The refractive index (n1) of the first optical adjustment layer 13 may be, for example, 1.55 to 1.90 or 1.60 to 1.80. If the refractive index of the first optical adjustment layer 13 is too low, the total light transmittance at the portion (conductive portion) where the transparent conductive layer is present in the sensing pattern tends to decrease. On the other hand, when the sensing pattern is formed when the refractive index of the first optical adjustment layer 13 is too high, the b ^* value of the transmitted light in the portion where the transparent conductive layer 16 is removed (non-conductive portion) is small on the negative side. Tend to be. That is, a color difference tends to occur in the transmitted light depending on the sensing pattern.

  The thickness of the first optical adjustment layer 13 is, for example, 10 to 2000 nm. If the first optical adjustment layer 13 becomes too thin, the production of the first optical adjustment layer 13 by application tends to be difficult. In addition, the transmittance tends to decrease as the reflectivity of the conductive portion increases. On the other hand, if the first optical adjustment layer 13 becomes too thick, the warp of the transparent conductor 100 tends to increase.

As a resin composition for producing the first optical adjustment layer 13, for example, TYT80 (trade name, refractive index: titanium oxide (TiO ₂ ) dispersed in an acrylic energy ray curable resin composition. 1.80, manufactured by Toyo Ink Co., Ltd.), TYZ70 (trade name, refractive index: 1.70, Toyo Ink (ZrO ₂ ) dispersed in an acrylic energy ray-curable resin composition) And TYZ74 (trade name, refractive index: 1.74, manufactured by Toyo Ink Co., Ltd.). A resin composition containing a polymer having a high refractive index may be used. Examples of the high refractive index polymer include UR-101 (trade name, refractive index: 1.70, manufactured by Nissan Chemical Industries).

  The first optical adjustment layer 13 can be formed by applying the above-described resin composition on the transparent substrate 10 and drying it, followed by curing with ultraviolet irradiation. The coating method at this time can be performed by a known method. Examples of the coating method include an extrusion nozzle method, a blade method, a knife method, a bar coating method, a kiss coating method, a kiss reverse method, a gravure roll method, a dip method, a reverse roll method, a direct roll method, a curtain method, and a squeeze method. Etc.

  The first optical adjustment layer 13 may have a function of suppressing the occurrence of warpage (curl) of the transparent conductor 100. The composition of each optical adjustment layer is, for example, that a cut surface obtained by cutting the transparent conductor 100 using a focused ion beam device (FIB) is a transmission electron microscope (TEM) or a scanning electron microscope ( It can be determined by analyzing using an energy dispersive X-ray spectrometer (EDS) attached to the SEM.

(Second optical adjustment layer 14)
The second optical adjustment layer 14 can be composed of a layer made of an inorganic oxide and / or a layer made of a cured resin obtained by curing the resin composition with energy rays.

  The refractive index (n2) of the second optical adjustment layer 14 is smaller than n1 and n3, and may be, for example, 1.40 to 1.65 or 1.45 to 1.55. From the viewpoint of optical characteristics, the refractive index (n2) is preferably low. However, low refractive index materials are usually expensive. For this reason, if the refractive index (n2) becomes too low, the material cost tends to increase. From such a viewpoint, the refractive index (n2) is preferably set in the above-described range.

  The thickness of the second optical adjustment layer 14 may be 5 to 80 nm, 10 to 70 nm, or 15 to 60 nm. When the second optical adjustment layer 14 becomes too thin, the reflectance increases and the transmittance tends to decrease. On the other hand, if the second optical adjustment layer 14 becomes too thick, the difference in reflectance between the conductive portion and the non-conductive portion when the sensing pattern is formed tends to increase, and the sensing pattern tends to be easily recognized.

When the 2nd optical adjustment layer 14 has a layer which consists of resin hardened | cured materials, it can form by the same method using the resin composition similar to the case where the 1st optical adjustment layer 13 is formed. Examples of the resin composition include TYZ60 (trade name, refractive index: 1.60, manufactured by Toyo Ink Co., Ltd.) in which zirconium oxide (ZrO ₂ ) is dispersed in an acrylic energy ray-curable resin composition. And SD-318 (trade name, refractive index: 1.48, manufactured by Toyo Ink Co., Ltd.).

  The second optical adjustment layer 14 can be formed by applying the above-described resin composition on the first optical adjustment layer 13 and drying it, followed by curing by irradiation with ultraviolet rays. The coating method at this time can be performed by a known method. Examples of the coating method include an extrusion nozzle method, a blade method, a knife method, a bar coating method, a kiss coating method, a kiss reverse method, a gravure roll method, a dip method, a reverse roll method, a direct roll method, a curtain method, and a squeeze method. Etc.

When the second optical adjustment layer 14 has a layer made of an inorganic oxide, the inorganic oxide preferably contains silicon oxide (SiO ₂ , refractive index: 1.46). The layer made of an inorganic oxide can be manufactured by a vacuum film forming method such as a vacuum evaporation method, a sputtering method, an ion plating method, or a CVD method. Among these, the sputtering method is preferable in that the film forming chamber can be reduced in size.

  In the sputtering method, the second optical adjustment layer 14 can be formed on the first optical adjustment layer 13 by a reactive sputtering method using an oxide target and a reactive gas.

The second optical adjustment layer 14 may contain the following trace components in addition to the inorganic oxide. Examples of the trace component include lithium fluoride (LiF, refractive index: 1.36), magnesium fluoride (MgF, refractive index: 1.38), calcium fluoride (CaF ₂ , refractive index: 1.4), And cerium fluoride (CeF, refractive index: 1.63). The content of silicon oxide in the layer made of an inorganic oxide is, for example, 90 mol% or more and 95 mol% or more. Further, the second optical adjustment layer 14 may be a mixture of nitrogen oxide and silicon oxide. The content of silicon nitride can be adjusted by changing the reactive gas in the reactive sputtering method.

(Third optical adjustment layer 15)
The third optical adjustment layer 15 may be a layer composed of an inorganic compound. Examples of inorganic compounds include silicon nitride (Si ₃ N ₄ , refractive index: 2.00), silicon oxide (SiO ₂ , refractive index: 1.46), titanium oxide (TiO ₂ , refractive index: 2.35), and oxidation. Zirconium (ZrO, refractive index: 2.05), cerium oxide (CeO ₂ , refractive index: 2.30), niobium oxide (Nb ₂ O ₅ , refractive index: 2.30), antimony oxide (Sb ₂ O ₅ refraction) And at least one selected from tantalum oxide (Ta ₂ O ₃ , refractive index: 2.10), and zinc oxide (ZnO ₂ , refractive index: 2.00). The refractive index of the third optical adjustment layer 15 can be adjusted by changing the mixing ratio of the inorganic oxide. For example, the refractive index of the third optical adjustment layer 15 in the case of containing silicon nitride and silicon oxide is, for example, in the range of 1.7 to 2.0 by changing the mixing ratio of silicon nitride and silicon oxide. Can do.

  Of the inorganic oxides, silicon nitride or a combination of silicon nitride and silicon oxide is preferably contained. When the inorganic oxide is silicon nitride and silicon oxide, the molar ratio of silicon nitride to the total of silicon nitride and silicon oxide may be 30 mol% or more, 40 mol% or more, or 50 mol% or more. It may be. The ratio of silicon nitride and silicon oxide can be adjusted by changing the composition of the reactive gas in the reactive sputtering method. From the viewpoint of increasing the refractive index (n3) of the third optical adjustment layer 15, the third optical adjustment layer 15 may contain titanium oxide.

  The third optical adjustment layer 15 can be produced by a vacuum film forming method such as a vacuum deposition method, a sputtering method, an ion plating method, or a CVD method. Among these, the sputtering method is preferable in that the film forming chamber can be reduced in size. The sputtering method is particularly preferable when there are a plurality of layers to be formed.

  In the sputtering method, the third optical adjustment layer 15 can be formed on the second optical adjustment layer 14 by a reactive sputtering method using an oxide target, a metal or metalloid target, and a reactive gas. . The reactive sputtering method is a method of forming a metal or metalloid oxide or nitride film by adding a reactive gas such as oxygen or nitrogen to an inert gas such as argon gas. The reactive sputtering method using a metal or metalloid target can increase the deposition rate as compared with the case of using an oxide target.

  The thickness of the 3rd optical adjustment layer 15 becomes like this. Preferably it is 1-20 nm, More preferably, it is 2-15 nm, More preferably, it is 5-12 nm. If the third optical adjustment layer 15 becomes too thick, the reflectance tends to be too high and the warp of the transparent conductor 100 may occur.

(Transparent conductive layer 16)
The transparent conductive layer 16 is a thin film made of a metal (or metalloid) oxide. Examples of the oxide include tin oxide, indium oxide, zinc oxide, titanium oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. It is done. Of these, the transparent conductive layer 16 preferably contains indium oxide or an indium-tin composite oxide. The content of tin oxide in the indium-tin composite oxide is, for example, 3 to 12% by weight. The refractive index of indium-tin composite oxide is usually around 2.00, and the refractive index of indium oxide is usually 1.9 to 2.1.

  The transparent conductive layer 16 is provided on the third optical adjustment layer 15. The transparent conductive layer 16 may cover the entire one surface of the third optical adjustment layer 15 or may cover only a part thereof. That is, the transparent conductive layer 16 may be patterned so as to cover a part of the one surface. The transparent conductive layer 16 can be formed by forming a film by a vacuum film formation method such as a vacuum deposition method, a sputtering method, an ion plating method, or a CVD method, and then performing a crystallization process. Of the above-described film forming methods, the sputtering method is preferable because the film forming chamber can be downsized. Since the transparent conductor 100 has a plurality of layers produced by a vacuum film forming method, the sputtering method is particularly preferable. The transparent conductive layer 16 is formed by heating and crystallizing after film formation. The heating conditions in this case are usually performed at a heating temperature of 140 ° C. and a heating time of about 90 minutes.

  From the viewpoint of the resistance value and the total light transmittance, the thickness of the transparent conductive layer 16 is, for example, 10 to 50 nm, and preferably 10 to 30 nm. If the transparent conductive layer 16 is too thin, it does not become dense and the resistance value tends to be unstable. On the other hand, if the transparent conductive layer 16 is too thick, the total light transmittance tends to be low.

The refractive index (n4) of the transparent conductive layer 16 is, for example, 1.4 to 2.4, and preferably 1.7 to 2.2. When the transparent conductive layer 16 having such a refractive index is adjacent to the third optical adjustment layer 15, the difference n4-n3 is reduced. For this reason, even if a small amount of the transparent conductive layer 16 remains in the non-conductive portion after the etching, it is difficult to visually recognize the remaining portion. From the same viewpoint, n3 and n4 preferably satisfy the following formula (4), and more preferably satisfy the following formula (6).
−0.3 ≦ n4-n3 ≦ 0.3 (4)
−0.2 ≦ n4-n3 ≦ 0.2 (6)

  The surface resistance value of the transparent conductive layer 16 is preferably low, and may be, for example, 300Ω / □ (300Ω / sq.) Or less, or 50 to 300Ω / □.

  The thickness of the transparent conductor 100 may be, for example, 200 μm or less, 130 μm or less, or 115 μm or less. Even if the thickness of the transparent conductor 100 is reduced, it is possible to make it difficult to visually recognize the minute amount of the transparent conductive layer 16 remaining in the non-conductive portion after the sensing pattern and etching.

  Etching of the transparent conductive layer 16 in the transparent conductor 100 is performed using a normal acidic etching solution such as hydrochloric acid after covering portions of the sensor electrodes 16a and 16b (see FIG. 4) serving as conductive portions with a resist. it can. The transparent conductive layer 16 is soluble in an acidic etching solution such as hydrochloric acid, while the third optical adjustment layer 15 is preferably insoluble in an acidic etching solution such as hydrochloric acid, that is, stable. .

  FIG. 2 is a photograph of a scanning electron microscope image (magnified 30,000) showing an example of the non-conductive portion after etching. In FIG. 2, the transparent conductive layer 16 remains in an island shape in the non-conductive portion after etching. Thus, even if the transparent conductive layer 16 remains in an island shape in the non-conductive portion, the transparent conductor 100 can make it difficult to visually recognize the remaining transparent conductive layer 16.

  FIG. 3 is a schematic cross-sectional view showing an enlarged part of a cross section of a touch panel 200 including a pair of sensor films. 4A and 4B are plan views of sensor films 100a and 100b using the transparent conductor 100 described above. The touch panel 200 includes a pair of sensor films 100 a and 100 b that are disposed to face each other via the optical glue 18. The touch panel 200 can calculate the touch position of the contact body as a coordinate position (horizontal position and vertical position) on a two-dimensional coordinate (XY coordinate) plane parallel to the panel board 70 serving as a screen. It is configured.

  Specifically, the touch panel 200 includes a sensor film 100a for longitudinal position detection (hereinafter referred to as “sensor film for Y”) and a sensor for position detection in the lateral direction, which are bonded together via the optical glue 18. A film 100b (hereinafter referred to as "sensor film for X"). On the lower surface side of the X sensor film 100b, a spacer 92 is provided between the X sensor film 100b and the panel plate 70 of the display device.

  A cover glass 19 is provided on the upper surface side (the side opposite to the panel plate 70 side) of the Y sensor film 100 a via an optical glue 17. That is, the touch panel 200 has a laminated structure in which the X sensor film 100b, the Y sensor film 100a, and the cover glass 19 are laminated in this order on the panel board 70 from the panel board 70 side.

  The Y sensor film 100a for detecting the vertical position and the X sensor film 100b for detecting the horizontal position are constituted by the transparent conductor 100 described above. The Y sensor film 100a and the X sensor film 100b have a sensor electrode 16a and a sensor electrode 16b, which are conductive portions, so as to face the cover glass 19.

  The sensor electrode 16 a is composed of the transparent conductive layer 16. As shown in FIG. 4A, a plurality of sensor electrodes 16a extend in the vertical direction (y direction) so that the touch position in the vertical direction (y direction) can be detected. The plurality of sensor electrodes 16a are arranged in parallel to each other along the vertical direction (y direction). One end of the sensor electrode 16a is connected to the electrode 80 on the driving IC side via a conductor line 50 formed of silver paste.

  The sensor electrode 16 b is composed of the transparent conductive layer 16. As shown in FIG. 4B, a plurality of sensor electrodes 16b extend in the horizontal direction (x direction) so that the touch position in the horizontal direction (x direction) can be detected. The plurality of sensor electrodes 16b are arranged in parallel to each other along the horizontal direction (x direction). One end of the sensor electrode 16b is connected to the electrode 80 on the driving IC side via a conductor line 50 formed of silver paste.

  When the Y sensor film 100a and the X sensor film 100b are viewed from the stacking direction of the Y sensor film 100a and the X sensor film 100b, the optical glue 18 is arranged so that the sensor electrodes 16a and 16b are orthogonal to each other. Are overlaid. A cover glass 19 is provided on the opposite side of the Y sensor film 100 a from the X sensor film 100 b side via an optical glue 17. As the optical glues 17, 18, the cover glass 19, and the panel plate 70, ordinary ones can be used.

  The conductor line 50 and the electrode 80 in FIGS. 4A and 4B are made of a conductive material such as metal (for example, Ag). The conductor line 50 and the electrode 80 are patterned by, for example, screen printing. The transparent substrate 10 also has a function as a protective film that covers the surface of the touch panel 200.

  The shape and number of the sensor electrodes 16a and 16b in the sensor films 100a and 100b are not limited to the forms shown in FIGS. For example, the detection accuracy of the touch position may be increased by increasing the number of sensor electrodes 16a and 16b.

  On the opposite side of the X sensor film 100b to the Y sensor film 100a side, a panel plate 70 is provided via a spacer 92. The spacer 92 can be provided at a position corresponding to the shape of the sensor electrodes 16a and 16b and a position surrounding the entire sensor electrodes 16a and 16b. The spacer 92 may be formed of a light-transmitting material, for example, PET (polyethylene terephthalate) resin. One end of the spacer 92 is bonded to the lower surface of the X sensor film 100b by an optical glue or an adhesive 90 having translucency such as acrylic or epoxy. The other end of the spacer 92 is bonded to the panel plate 70 of the display device with an adhesive 90. Thus, by arranging the X sensor film 100b and the panel plate 70 to face each other via the spacer 92, a gap S can be formed between the X sensor film 100b and the panel plate 70 of the display device. .

  A control unit (IC) is electrically connected to the electrode 80. The capacitance changes of the sensor electrodes 16a and 16b caused by the capacitance change between the fingertip and the Y sensor film 100a of the touch panel 200 are measured. The control unit can calculate the touch position of the contact body as a coordinate position (intersection of the position in the X-axis direction and the position in the Y-axis direction) based on the measurement result. In addition to the above, various known methods can be adopted as the sensor electrode driving method and the coordinate position calculation method.

  The touch panel 200 can be manufactured by the following procedure. After preparing the transparent conductor 100, the transparent conductive layer 16 is etched and patterned. Specifically, a resist material is applied to the surface of the transparent conductive layer 16 by spin coating using a photolithography technique. Thereafter, pre-baking may be performed to improve adhesion. Subsequently, a resist pattern is formed by arranging and exposing a mask pattern and developing with a developer. The formation of the resist pattern is not limited to photolithography, and can be formed by screen printing or the like. As the etchant, an inorganic acid-based etchant can be used. For example, a hydrochloric acid-based etching solution is suitable.

  Next, the transparent conductor 100 on which the resist pattern is formed is immersed in an acidic etching solution, and the transparent conductive layer 16 in a portion where the resist pattern is not formed is dissolved and removed. Thereafter, the resist is removed to obtain the Y sensor film 100a on which the sensor electrode 16a is formed and the X sensor film 100b on which the sensor electrode 16b is formed.

  Subsequently, for example, a metal paste such as a silver alloy paste is applied to form the conductor line 50 and the electrode 80. In this way, the control unit and the sensor electrodes 16a and 16b are electrically connected. Next, the Y sensor film 100a and the X sensor film 100b are bonded using the optical glue 18 so that the sensor electrodes 16a and 16b face in the same direction. In this case, the sensor electrodes 16a and 16b are bonded so as to be orthogonal to each other when viewed from the stacking direction of the Y sensor film 100a and the X sensor film 100b. Then, the cover glass 19 and the Y sensor film 100 a are bonded together using the optical glue 17. In this way, the touch panel 200 can be manufactured.

  Since the touch panel 200 uses the transparent conductor 100 as the Y sensor film 100a and the X sensor film 100b, the touch panel 200 can be sufficiently thinned. Even if the thickness is reduced in this manner, the sensing patterns of the Y sensor film 100a and the X sensor film 100b and the trace amount of the transparent conductive layer remaining after etching can be made sufficiently difficult to visually recognize. In addition, it is not necessary to use the transparent conductor 100 for both the Y sensor film 100a and the X sensor film 100b, and either one may use another transparent conductor. Even with such a touch panel, not only the sensing pattern but also a small amount of the transparent conductive layer remaining after etching can be made difficult to visually recognize.

  FIG. 5 is a schematic cross-sectional view showing another embodiment of the transparent conductor of the present invention. The transparent conductor 101 is different from the transparent conductor 100 in that the optical adjustment layer 11a includes a fourth optical adjustment layer 40 between the second optical adjustment layer 14 and the third optical adjustment layer 15. Is different. Other configurations are the same as those of the transparent conductor 100.

The range of the refractive index (n5) of the fourth optical adjustment layer 40 is the same as that of n2, and may be, for example, 1.40 to 1.65, or 1.45 to 1.55. . n5 preferably satisfies the following formula (7), formula (8), and formula (9).
n1-n5 ≧ 0.1 (7)
-0.1 <n2-n5 <0.1 (8)
n3-n5 ≧ 0.1 (9)

  The fourth optical adjustment layer 40 may be made of the same material as that of the second optical adjustment layer 14. For example, the fourth optical adjustment layer 40 may be composed of a layer made of an inorganic oxide and / or a layer made of a cured resin obtained by curing a resin composition with energy rays. Among these, it is preferable that one of the second optical adjustment layer 14 and the fourth optical adjustment layer 40 is made of a cured resin and the other is made of an inorganic oxide. In this way, by combining the cured resin easily increasing the layer thickness and the inorganic oxide having an easy layer thickness accuracy, the thickness of the entire optical adjustment layer 11a and the transparent conductor 101 can be accurately controlled. The sensing pattern can be made more difficult to visually recognize.

  More preferably, the second optical adjustment layer 14 is a layer made of a cured resin, and the fourth optical adjustment layer 40 is a layer made of an inorganic oxide. Thereby, it is possible to make it difficult to visually recognize the sensing pattern by accurately controlling the thickness of the entire optical adjustment layer 11a and the transparent conductor 101, and to improve the productivity at a higher level. The thickness of the fourth optical adjustment layer 40 may be 5 to 80 nm, 10 to 70 nm, or 15 to 60 nm as the sum of the thickness of the second optical adjustment layer 14. Good.

  By using the above-described transparent conductors 100 and 101, a device in which a minute amount of the transparent conductive layer 16 remaining in the sensing pattern and the non-conductive portion is difficult to be visually recognized can be manufactured. For this reason, the transparent conductors 100 and 101 of the above embodiments can be suitably used for touch panels. However, the application is not limited to the touch panel. For example, the transparent conductive layer is processed into a predetermined shape, and the portion having the transparent conductive layer (conductive portion) and the portion having no transparent conductive layer (non-conductive) In various display devices such as liquid crystal display (LCD), plasma display panel (PDP), electroluminescence panel (organic EL, inorganic EL), electrochromic element, and electronic paper, for transparent electrodes, It can be used for antistatic and electromagnetic shielding. It can also be used as an antenna.

  As mentioned above, although suitable embodiment was described, a transparent conductor and a touch panel are not limited to the above-mentioned embodiment. For example, the transparent conductor may include a hard coat layer adjacent to the transparent substrate 10 or may include a pair of hard coat layers so as to sandwich the transparent substrate 10. The hard coat layer may be provided to prevent scratches on the transparent conductor. The hard coat layer contains a cured resin obtained by curing the resin composition. Moreover, in order to improve the mechanical strength of a transparent conductor, you may provide a protective film.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Example 1]
A transparent conductor 100 as shown in FIG. 1 was produced. The transparent conductor has a laminated structure in which the transparent substrate 10, the first optical adjustment layer 13, the second optical adjustment layer 14, the third optical adjustment layer 15, and the transparent conductive layer 16 are laminated in this order. doing. The transparent conductor 100 having such a structure was produced as follows.

  A polyethylene terephthalate film having a thickness of 50 μm (manufactured by Teijin DuPont Films, product number: KEL-86w) was prepared. This PET film was used as the transparent substrate 10. The refractive index of the transparent substrate 10 was 1.60.

<Preparation of the first optical adjustment layer 13>
TYZ70 (trade name, manufactured by Toyo Ink Co., Ltd.) containing zirconium oxide (ZrO ₂ ) was diluted with propylene glycol monomethyl ether (PGMA) as a solvent to prepare a coating material. The obtained paint was used as a paint for producing the first optical adjustment layer 13.

On the transparent base material 10, the coating material for 1st optical adjustment layer 13 preparation was apply | coated by the roll toe roll system, and the coating film was produced. After removing the solvent in the coating film in a drying oven set at 80 ° C., the coating film was cured by irradiating with an ultraviolet ray having an integrated light amount of 400 mJ / cm ² using a UV processing apparatus. In this way, the first optical adjustment layer 13 was produced on the transparent substrate 10. The refractive index (n1) and thickness of the first optical adjustment layer 13 were as shown in Table 1.

<Preparation of Second Optical Adjustment Layer 14>
On the 1st optical adjustment layer 13, the 2nd optical adjustment layer 14 was produced. Specifically, SD-318 (trade name, manufactured by DIC Corporation, acrylic resin) was diluted with a solvent to prepare a coating material. On the 1st optical adjustment layer 13, this coating material was apply | coated by the roll-to-roll system, and the coating film was produced. After removing the solvent in the coating film in a drying furnace set at 80 ° C., the coating film is cured by irradiating the coating film with ultraviolet rays with an integrated light amount of 400 mJ / cm ² using a UV processing apparatus, and the second optical adjustment layer 14 Formed. The refractive index (n2) and thickness of the second optical adjustment layer 14 were as shown in Table 1.

<Preparation of Third Optical Adjustment Layer 15>
On the 2nd optical adjustment layer 14, the 3rd optical adjustment layer 15 was produced using sputtering method. Specifically, a silicon target doped with boron is used to form a film in a mixed atmosphere composed of 80% by volume of argon gas, 5% by volume of oxygen gas, and 15% by volume of nitrogen gas, and from silicon nitride and silicon oxide. A third optical adjustment layer 15 was produced. The refractive index (n3) of the third optical adjustment layer 15 was as shown in Table 1. From the refractive index value, the molar ratio of silicon nitride (SiN) to silicon oxide (SiO ₂ ) in the third optical adjustment layer 15 was 60:40.

<Preparation of transparent conductive layer 16>
A transparent conductive layer 16 was produced on the third optical adjustment layer 15 by sputtering. Specifically, using a target obtained by adding 5% by weight of tin oxide to indium oxide, a film was formed in a mixed atmosphere consisting of 98% by volume of argon gas and 2% by volume of oxygen gas. A transparent conductive layer 16 made of the composite oxide was prepared. Thereafter, the laminate was heated in an oven at 140 ° C. for 90 minutes to produce a transparent conductor 100. The transparent conductive layer 16 had a thickness of 21 nm and a refractive index (n4) of 2.00.

<Evaluation of each layer>
The thickness of each layer shown in Tables 1 to 5 was measured by the following procedure. The produced transparent conductor 100 was cut by a focused ion beam device (FIB, Focused Ion Beam). The cut surface was observed using a transmission electron microscope (TEM), and the thickness of each layer was measured.

  The refractive index of the PET film (transparent substrate 10) was measured using an optical film thickness measuring device (trade name: ETA-RT, manufactured by STEAG ETA-Optik). On the other hand, the refractive indexes of the first optical adjustment layer 13, the second optical adjustment layer 14, the third optical adjustment layer 15, and the transparent conductive layer 16 were measured by separately preparing a refractive index measurement film. Specifically, it is applied onto a silicon wafer to form a film, and using an ellipsometer (trade name: DHA-OLX, manufactured by Mizoji Optical Co., Ltd.), the film (layer) at λ = 633 nm at 20 ° C. The refractive index was measured.

<Evaluation of reflectance>
A part of the transparent conductive layer 16 in the transparent conductor 100 was covered with a mask, and the other part of the transparent conductive layer 16 was removed using an etching solution (Chromat IT (trade name), manufactured by Fuji Giken Kogyo Co., Ltd.). In order to evaluate the influence of the remaining amount of the transparent conductive layer 16, the sample (1) in which the transparent conductive layer 16 is completely removed by etching and the sample in which the transparent conductive layer 16 is etched to leave a small amount of the transparent conductive layer 16 remain. (2) and a sample (3) before etching the transparent conductive layer 16 were prepared. The reflectances of samples (1), (2), and (3) were measured with a spectrophotometer (CM-5 (trade name), manufactured by Konica Minolta). The average values of the reflectances of the samples (1), (2), and (3) at wavelengths of 450 to 650 nm are shown in Table 1 as reflectances (1), (2), and (3), respectively.

  Sample (2) was prepared as follows. Etching of the transparent conductor 100 was performed in increments of 20 seconds from 40 seconds to 120 seconds. Every 20 seconds, the electrical resistance of the transparent conductor 100 was measured using a card high tester (trade name, manufactured by Hioki Electric Co., Ltd.). When the electrical resistance is plotted on the vertical axis with the etching time on the horizontal axis, the sample at the point when the electrical resistance exceeds the measurement range and overloads (the electrical resistance is overloaded and the etching time is the shortest) (2).

[Example 2]
In the production of the third optical adjustment layer 15, a boron-doped silicon target was used to form a film in a mixed atmosphere composed of 80% by volume of argon gas, 2% by volume of oxygen gas, and 18% by volume of nitrogen gas, A transparent conductor 100 was produced in the same manner as in Example 1 except that the third optical adjustment layer 15 made of silicon nitride and silicon oxide was produced. Each evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
In the production of the third optical adjustment layer 15, using a boron-doped silicon target, a film was formed in a mixed atmosphere composed of 80% by volume of argon gas and 20% by volume of nitrogen gas, and a third layer made of silicon nitride. A transparent conductor 100 was produced in the same manner as in Example 1 except that the optical adjustment layer 15 was produced. Each evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
In the preparation of the third optical adjustment layer 15, using a target consisting of _TiO 2 (50 wt%) _ZnO 2 (50 wt%) and, was deposited in an argon gas atmosphere, and an oxide of titanium oxide, zinc A transparent conductor 100 was produced in the same manner as in Example 1 except that the third optical adjustment layer 15 was produced. Each evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
In the production of the third optical adjustment layer 15, a silicon target doped with boron is used to form a film in a mixed atmosphere consisting of 85% by volume of argon gas and 15% by volume of oxygen gas, and a third layer made of silicon oxide. A transparent conductor was produced in the same manner as in Example 1 except that the optical adjustment layer 15 was produced. Each evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
Example 1 except that in the production of the third optical adjustment layer 15, a target made of TiO ₂ was used to form a film in an argon gas atmosphere to produce a third optical adjustment layer made of titanium oxide. A transparent conductor 100 was produced in the same manner as described above. Each evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

  Table 1 shows the values of “reflectance (3) −reflectivity (1)” and “reflectivity (2) —reflectivity (1)” (hereinafter these values are collectively referred to as “ "Reflectance difference"). As the absolute value of the difference in reflectance is smaller, the transparent conductive layer and the sensing pattern remaining after etching can be made less visible.

  As shown in Table 1, it was confirmed that the transparent conductor of each example had a sufficiently small absolute value of reflectance difference of less than 1.0. On the other hand, the transparent conductor of each comparative example has an absolute value of a difference of reflectance (3) −reflectance (1) of 1.0 or more, and it was confirmed that the sensing pattern is easily visible. In addition, the transparent conductor of Comparative Example 1 has an absolute value of reflectance (2) −reflectance (1) of 0.7 or more, and a small amount of the transparent conductive layer remaining after etching is more visible than each example. It was confirmed that it was easy to be done.

[Example 5]
A first optical adjustment layer 13 was produced in the same manner as in Example 3. On this, the 2nd optical adjustment layer 14 was formed using sputtering method. Specifically, using a boron-doped silicon target, a second atmosphere composed of silicon nitride and silicon oxide in a mixed atmosphere composed of 80% by volume of argon gas, 10% by volume of oxygen gas, and 10% by volume of nitrogen gas. The optical adjustment layer 14 (refractive index: 1.60) was produced.

  In the same manner as in Example 3, the third optical adjustment layer 15 and the transparent conductive layer 16 were produced, and the transparent conductor 100 was produced. Each evaluation was performed in the same manner as in Example 3. The results are shown in Table 2. For comparison, the results of Example 3 are also shown in Table 2.

[Comparative Example 3]
Except for forming the second optical adjustment layer 14 made of silicon nitride by forming a film in a mixed atmosphere composed of 80% by volume of argon gas and 20% by volume of nitrogen gas using a silicon target doped with boron. A transparent conductor was produced in the same manner as in Example 5. Each evaluation was performed in the same manner as in Example 5. The results are shown in Table 2.

  As shown in Table 2, in Comparative Example 3 in which the values of n3-n2 and n1-n2 are smaller than a predetermined value, the absolute value of the difference in reflectance may be 1.0 or more, and the sensing pattern is easily visible. It was confirmed.

[Examples 6 to 11]
The transparent conductor 100 of Examples 6-11 was produced like Example 3 except having adjusted the time of sputtering and having changed the thickness of the 3rd optical adjustment layer 15 as shown in Table 3. did. Then, each layer and the transparent conductor were evaluated in the same manner as in Example 3. The evaluation results are shown in Table 3. For comparison, the results of Example 3 are also shown in Table 3.

[Comparative Example 4]
A transparent conductor of Comparative Example 4 was produced in the same manner as in Example 3 except that the third optical adjustment layer 15 was not produced. Then, in the same manner as in Example 1, each layer and the transparent conductor were evaluated. The evaluation results are shown in Table 3.

  As shown in Table 3, the absolute value of the difference in reflectance could be made less than 1.0 by providing the third optical adjustment layer 15. On the other hand, in Comparative Example 4 in which the third optical adjustment layer 15 is not provided, the absolute value of reflectance (3) −reflectance (1) is 1.0 or more, and it has been confirmed that the sensing pattern is easily visible. . Further, the transparent conductor of Comparative Example 4 has an absolute value of reflectance (2) -reflectance (1) of 0.8, and a small amount of the transparent conductive layer remaining after etching is more visible than in each example. It was confirmed that it was easy.

[Example 12]
A transparent conductor 100 was produced in the same manner as in Example 3 except that the coating amount of the paint was adjusted so that the thickness of the second optical adjustment layer 14 was 55 nm. Then, each layer and the transparent conductor were evaluated in the same manner as in Example 3. The evaluation results are shown in Table 4. For comparison, the results of Example 3 are also shown in Table 4.

[Comparative Example 5]
A transparent conductor was produced in the same manner as in Example 3 except that the second optical adjustment layer 14 was not produced. Then, each layer and the transparent conductor were evaluated in the same manner as in Example 3. The evaluation results are shown in Table 4.

  As shown in Table 4, even when the thickness of the second optical adjustment layer 14 was changed, the absolute value of the difference in reflectance could be made less than 1.0 (Example 12). On the other hand, in Comparative Example 5 in which the second optical adjustment layer 14 was not provided, the absolute value of reflectance (3) −reflectance (1) was 1.0 or more, and it was confirmed that the sensing pattern was easily visible. .

[Example 13]
Implementation was performed except that the coating amount of the paint was adjusted so that the thickness of the second optical adjustment layer 14 was as shown in Table 5 and that the first optical adjustment layer 13 was produced as follows. A transparent conductor 100 was produced in the same manner as in Example 3. Then, each layer and the transparent conductor were evaluated in the same manner as in Example 3. The evaluation results are shown in Table 5.

The first optical adjustment layer 13 was produced as follows. Specifically, TYZ74 (trade name, manufactured by Toyo Ink Co., Ltd., acrylic resin) containing zirconium oxide (ZrO ₂ ) was diluted with a solvent to prepare a coating material. On the transparent base material 10, this coating material was apply | coated by the roll to roll system, and the coating film was produced. After removing the solvent in the coating film in a drying furnace set at 80 ° C., the coating film is cured by irradiating the coating film with ultraviolet rays having an integrated light amount of 400 mJ / cm ² using a UV processing apparatus, and the first optical adjustment layer 13 is then cured. Formed.

[Comparative Example 6]
A transparent conductor was produced in the same manner as in Example 13 except that the third optical adjustment layer 15 was not produced. Then, each layer and the transparent conductor were evaluated in the same manner as in Example 3. The evaluation results are shown in Table 5.

  As shown in Table 5, it was confirmed that even when the thickness of the first optical adjustment layer 13 was increased, the absolute value of the difference in reflectance could be made less than 1.0 (Example 13). In Comparative Example 6 in which the third optical adjustment layer 15 was not provided, the absolute value of the difference in reflectance was 1.0 or more, and it was confirmed that the transparent conductive layer and the sensing pattern remaining after etching were easily visible. It was.

  A transparent conductor in which the transparent conductive layer remaining in the non-conductive portion is hardly visible is provided. In addition, a touch panel is provided in which the transparent conductive layer remaining in the non-conductive portion is hardly visible.

  DESCRIPTION OF SYMBOLS 10 ... Transparent base material, 11 ... Optical adjustment layer, 13 ... 1st optical adjustment layer, 14 ... 2nd optical adjustment layer, 15 ... 3rd optical adjustment layer, 16 ... Transparent conductive layer, 16a, 16b ... Sensor Electrode, 17, 18 ... Optical glue, 19 ... Cover glass, 50 ... Conductor line, 70 ... Panel plate, 80 ... Electrode, 90 ... Adhesive, 92 ... Spacer, 100, 101 ... Transparent conductor, 100a ... Sensor for Y Film, 100b ... Sensor film for X, 200 ... Touch panel.

Claims (6)

A transparent conductor comprising a transparent substrate, a transparent conductive layer, and an optical adjustment layer between the transparent substrate and the transparent conductive layer,
The optical adjustment layer has a first optical adjustment layer, a second optical adjustment layer, and a third optical adjustment layer from the transparent substrate side,
When the refractive indexes of the first optical adjustment layer, the second optical adjustment layer, and the third optical adjustment layer are n1, n2, and n3, respectively, the following formulas (1) and (2) And a transparent conductor satisfying the formula (3).
1.7 ≦ n3 ≦ 2.2 (1)
n3-n2 ≧ 0.1 (2)
n1-n2 ≧ 0.1 (3)   The transparent conductor according to claim 1, wherein the third optical adjustment layer contains silicon nitride or silicon nitride and silicon oxide, and the transparent conductive layer contains indium oxide.   The transparent conductor according to claim 1 or 2, wherein the third optical adjustment layer has a thickness of 2 to 15 nm.   The transparent conductor according to claim 1, wherein the transparent conductive layer has a thickness of 10 to 30 nm. The transparent conductor as described in any one of Claims 1-4 which satisfy | fills following formula (4) when the refractive index of the said transparent conductive layer is set to n4.
−0.3 ≦ n4-n3 ≦ 0.3 (4) A touch panel having a sensor film on a panel board,
The touch panel with which the said sensor film is comprised with the transparent conductor as described in any one of Claims 1-5.