JP5287201B2 - Transparent conductive laminated film - Google Patents

Description

  The present invention relates to a transparent conductive film in which a composition-graded thin film layer and a transparent conductive thin film layer are laminated in this order on at least one surface of a substrate made of a transparent plastic film. In particular, when used as a patterned electrode film such as a capacitive touch panel, the difference in optical properties between the portion having the transparent conductive thin film layer and the removed portion is small, so that the transparent conductive film that can improve visibility It is about.

  A transparent conductive film obtained by laminating a transparent thin film with low resistance on a substrate made of a transparent plastic film is used for applications utilizing the conductivity, for example, a liquid crystal display or electroluminescence (EL may be abbreviated as EL). ) Widely used in electrical and electronic fields such as flat panel displays such as displays and transparent electrodes of resistive touch panels.

  In recent years, an increasing number of cases where a capacitive touch panel is mounted on a mobile device such as a mobile phone or a portable music terminal. Such a capacitive touch panel has a configuration in which a dielectric layer is laminated on a patterned conductor, and is touched with a finger or the like to be grounded via the capacitance of the human body. At this time, a change occurs in the resistance value between the patterning electrode and the ground point, and the position input is recognized. However, when a conventional transparent conductive film is used, the difference in optical characteristics between the portion having the transparent conductive thin film layer and the removed portion is large, so that patterning is emphasized and placed on the front surface of a display body such as a liquid crystal display. There has been a problem that the visibility is lowered when it is done.

In order to improve the transmittance or color of the transparent conductive film, a method of using light interference by laminating layers having different refractive indexes used in antireflection processing or the like has been proposed. That is, a method of using optical interference by providing layers having different refractive indexes between a transparent conductive thin film layer and a base film has been proposed (Patent Documents 1 to 3).
Japanese Patent Laid-Open No. 11-286066 Japanese Patent No. 3626624 JP 2006-346878 A

  However, although these transparent conductive films described in Patent Documents 1 to 3 can improve the visibility as a transparent conductive film, when the transparent conductive thin film layer is patterned, there is no portion with the transparent conductive thin film. It is not considered to reduce the difference in optical characteristics between the portions, and the patterned portions are emphasized.

  That is, in view of the above-mentioned conventional problems, the object of the present invention is to visually recognize when used in a liquid crystal display or the like by reducing the difference in optical characteristics between the portion having the transparent conductive thin film layer and the removed portion. An object of the present invention is to provide a transparent conductive laminated film that has good properties and does not emphasize patterning.

This invention is made | formed in view of the above situations, Comprising: The transparent conductive lamination which was able to solve said subject consists of the following structures.
1. A transparent conductive laminated film in which a composition gradient thin film layer and a transparent conductive thin film layer are provided in this order on at least one surface of a substrate made of a transparent plastic film, the composition gradient thin film layer having a thickness of 20 to 500 nm, The refractive index of the inclined thin film layer varies in the thickness direction, the maximum value of the refractive index is 1.70 or more (refractive index of the transparent conductive thin film layer +0.30) or less, and the minimum value of the refractive index is 1.30 or more. 1. A transparent conductive laminated film, which is 1.65 or less.
2. 1. The composition gradient thin film layer is an inorganic thin film layer comprising at least one element selected from Mg, Si, and Al and at least two elements selected from O, N, C, and F. The transparent conductive laminated film described in 1.
3. 1. The refractive index of the composition gradient thin film layer continuously decreases from the base material to the transparent conductive thin film layer side. Or 2. The transparent conductive laminated film described in 1.
4). 1. The transparent conductive thin film layer is composed of a metal oxide thin film containing indium. ~ 3. The transparent electroconductive laminated film in any one.
5. Transparent conductive thin film measured in a state where a biaxially oriented polyethylene terephthalate film having an acrylic adhesive layer having a refractive index of 1.52 is laminated on the transparent conductive thin film layer side of the transparent conductive laminated film patterned with the transparent conductive thin film layer 1. The reflectance of the part which has a layer, and the part which does not have a transparent conductive thin film layer satisfy | fill the following (1), (2), and (3) Formula. ~ 4. The transparent conductive laminated film according to any one of the above.
0 ≦ | R1-R0 | ≦ 1.0 (1)
R1 ≦ 5.0 (2)
R0 ≦ 5.0 (3)
(R1: reflectivity of a film having a transparent conductive thin film layer, R0: reflectivity of a film having a transparent conductive thin film layer)
6). 1. ~ 5. A dielectric layer having a refractive index of 1.40 or more and 1.70 or less is laminated on the transparent conductive thin film layer side of the transparent conductive thin film obtained by patterning the transparent conductive thin film layer of any one of the transparent conductive laminated films A transparent conductive laminated film with a dielectric layer.

  The transparent conductive laminated film of the present invention has a configuration in which a composition gradient thin film layer and a transparent conductive thin film layer are laminated in this order on at least one surface of a substrate made of a transparent plastic film, and the transparent conductive thin film layer is patterned. In this case, since the difference in optical characteristics between the portion having the transparent conductive thin film layer and the portion not having the transparent conductive thin film layer is small, the patterning of the transparent conductive thin film layer cannot be seen even if it is arranged on the front surface of the display body such as a liquid crystal display. Reduction can be suppressed.

The transparent conductive laminated film of this invention has the structure which laminated | stacked the composition inclination thin film layer and the transparent conductive thin film layer in this order on the at least single side | surface of the base material which consists of a transparent plastic film.
Furthermore, it is a transparent conductive laminated film characterized by laminating a dielectric layer on the transparent conductive thin film layer side of the transparent conductive laminated film obtained by patterning the transparent conductive thin film layer of the transparent conductive laminated film.
Hereinafter, each layer will be described in detail.

(Base material made of transparent plastic film)
The substrate made of a transparent plastic film used in the present invention is formed by forming an organic polymer into a film by melt extrusion or solution extrusion into a film, and if necessary, stretching in the longitudinal direction and / or the width direction, A film that has been fixed and heat-relaxed. Organic polymers include polyethylene, polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyimide, polyamideimide, polyethersulfane, polyetheretherketone , Polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyether imide, polyphenylene sulfide, polyphenylene oxide, polystyrene, syndiotactic polystyrene, norbornene-based polymer, and the like.

  Among these organic polymers, polyethylene terephthalate, polypropylene terephthalate, polyethylene-2,6-naphthalate, syndiotactic polystyrene, norbornene polymer, polycarbonate, polyarylate and the like are preferable. These organic polymers may be copolymerized with a small amount of other organic polymer monomers, or may be blended with other organic polymers.

  It is preferable that the thickness of the base material which consists of a transparent plastic film used by this invention is 10-300 micrometers, More preferably, it is 70-260 micrometers. If the thickness of the plastic film is less than 10 μm, the mechanical strength is insufficient, and handling in the pattern forming process of the transparent conductive thin film becomes difficult, which is not preferable. On the other hand, if the thickness exceeds 300 μm, the thickness of the touch panel becomes too thick, which is not suitable for mobile devices.

  The substrate made of a transparent plastic film used in the present invention is a range that does not impair the purpose of the present invention, such as corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, ozone treatment, etc. A surface activation treatment may be performed.

  In addition, the base material made of the transparent plastic film used in the present invention is mainly a curable resin for the purpose of improving adhesion to the composition gradient thin film layer, imparting chemical resistance, and preventing precipitation of low molecular weight substances such as oligomers. You may provide the hardened | cured material layer made into a structural component.

  The curable resin is not particularly limited as long as it is a resin that is cured by application of energy such as heating, ultraviolet irradiation, electron beam irradiation, etc., and silicone resin, acrylic resin, methacrylic resin, epoxy resin, melamine resin, polyester resin, urethane Resin etc. are mentioned. From the viewpoint of productivity, a curable resin containing an ultraviolet curable resin as a main component is preferable.

  Examples of such ultraviolet curable resins are synthesized from polyfunctional acrylate resins such as acrylic acid or methacrylic acid ester of polyhydric alcohol, diisocyanate, polyhydric alcohol and hydroxyalkyl ester of acrylic acid or methacrylic acid. Such polyfunctional urethane acrylate resins can be mentioned. If necessary, a monofunctional monomer such as vinyl pyrrolidone, methyl methacrylate, or styrene can be added to these polyfunctional resins for copolymerization.

  In order to improve the adhesion between the composition gradient thin film layer and the cured product layer, it is effective to further treat the cured product layer. Specific methods include a discharge treatment method that irradiates glow discharge or corona discharge, a method of increasing carbonyl group, carboxyl group, hydroxyl group, a chemical treatment method of treating with acid or alkali, and an amino group. And a method of increasing polar groups such as a hydroxyl group and a carbonyl group.

  The ultraviolet curable resin is usually used by adding a photopolymerization initiator. As the photopolymerization initiator, known compounds that absorb ultraviolet rays and generate radicals can be used without any particular limitation. Examples of such photopolymerization initiators include various benzoins, phenyl ketones, and benzophenones. And the like. The addition amount of the photopolymerization initiator is preferably 1 to 5 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin.

  The concentration of the resin component in the coating solution can be appropriately selected in consideration of the viscosity according to the coating method. For example, the proportion of the total amount of the ultraviolet curable resin and the photopolymerization initiator in the coating solution is usually 20 to 80% by mass. Moreover, you may add other well-known additives, for example, leveling agents, such as a silicone type surfactant and a fluorine type surfactant, to this coating liquid as needed.

  In the present invention, the prepared coating solution is coated on a substrate made of a transparent plastic film. The coating method is not particularly limited, and conventionally known methods such as a bar coating method, a gravure coating method, and a reverse coating method can be used.

  Moreover, it is preferable that the thickness of a hardened | cured material layer is the range of 0.1-15 micrometers, More preferably, it is 0.5-10 micrometers, Most preferably, it is 1-8 micrometers. When the thickness of the cured product layer is less than 0.1 μm, it becomes difficult to form a sufficiently cross-linked structure, so that chemical resistance is likely to be lowered, and adhesion due to low molecular weight such as oligomer is also liable to occur. . On the other hand, when the thickness of the cured product layer exceeds 15 μm, the productivity tends to decrease.

(Composition gradient thin film layer)
The composition gradient thin film layer in the present invention is an inorganic thin film, for example, an inorganic thin film layer comprising at least one element selected from Mg, Si, and Al and at least two elements selected from O, N, C, and F. Is mentioned. In the composition gradient thin film layer, the composition of each element constituting the thin film layer in the thickness direction changes in a gradient manner. By changing the composition of the composition gradient thin film layer in the thickness direction, the refractive index of the composition gradient thin film layer continuously decreases from the base material to the transparent conductive thin film layer side.

  The maximum value of the refractive index of the composition gradient thin film layer in the present invention (hereinafter also referred to as the maximum refractive index) is 1.70 or more (refractive index of the transparent conductive thin film layer +0.30) or less. Preferably, it is not more than (the value of the refractive index of the transparent conductive thin film layer). More preferably (refractive index of transparent conductive thin film layer -0.10) or less. When the maximum refractive index of the composition gradient thin film layer exceeds (refractive index of the transparent conductive thin film layer + 0.30), although the difference in reflectance at the presence or absence of the transparent conductive thin film layer decreases, the absolute value of the reflectance is It becomes large and visibility decreases. On the other hand, the minimum value of the refractive index (hereinafter also referred to as the minimum refractive index) in the composition gradient thin film layer is 1.30 or more and 1.65 or less. When the minimum refractive index in the composition gradient thin film layer is less than 1.30, a porous film is formed. Therefore, when a transparent conductive thin film is laminated, the electrical characteristics of the transparent conductive thin film layer are deteriorated. In addition, when the minimum refractive index in the composition gradient thin film layer exceeds 1.65, the reflectance difference in the presence / absence portion of the transparent conductive thin film layer decreases, but the absolute value of the reflectance increases and the visibility decreases. To do.

  The difference between the maximum refractive index and the minimum refractive index of the composition gradient thin film layer is preferably 0.10 or more and 0.80 or less. Preferably they are 0.15 or more and 0.70 or less, More preferably, they are 0.20 or more and 0.60 or less. When the difference between the maximum refractive index and the minimum refractive index of the composition gradient thin film layer is less than 0.10, it is difficult to reduce the reflectance difference in the presence or absence of the transparent conductive thin film layer. On the other hand, when the difference between the maximum refractive index and the minimum refractive index of the composition gradient thin film layer exceeds 0.80, the absolute value of the reflectance increases and the visibility decreases.

  Specific materials for the composition gradient thin film layer include an inorganic thin film composed of Si, O, and N elements, an inorganic thin film composed of Al, O, and N elements, and an inorganic thin film composed of a composite oxide thereof. Further, these inorganic thin films may contain C element as long as the optical properties are not impaired.

  The thickness of the composition gradient thin film layer is 20 to 500 nm, and preferably 20 to 250 nm. When the film thickness is less than 20 nm, it is difficult to change the composition continuously. On the other hand, when the film thickness exceeds 500 nm, the stress of the composition gradient thin film layer increases, and cracks are likely to occur in the transparent conductive thin film layer.

  The composition gradient thin film layer in the present invention can be formed by a film forming method such as a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, or a spray method. Depending on the required film thickness, the above method can be used as appropriate, but the sputtering method is preferred from the viewpoint of reducing variations in film thickness.

  For example, when producing a composition gradient thin film layer composed of three elements of Si, O, and N by sputtering, sputtering is performed while continuously changing the flow ratio of nitrogen and oxygen using a silicon (silicon) target. Is mentioned. At this time, it is preferable to perform the monitoring while monitoring the ratio of nitrogen and oxygen in the film forming atmosphere.

(Transparent conductive thin film layer)
Examples of the transparent conductive thin film in the present invention include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. . Of these, indium-tin composite oxides are preferable from the viewpoints of environmental stability and circuit processability.
In the present invention, a transparent conductive thin film layer is laminated, and the surface resistance value of the transparent conductive laminated film is preferably 50 to 2000 Ω / □, more preferably 100 to 1500 Ω / □. Can be used for touch panels. When the surface resistance value is less than 50Ω / □ or exceeds 2000Ω / □, the position recognition accuracy of the touch panel is deteriorated, which is not preferable.

  The thickness of the transparent conductive thin film is preferably in the range of 4 to 30 nm, more preferably 10 to 25 nm. When the film thickness of the transparent conductive thin film is less than 4 nm, it is difficult to form a continuous thin film, and it is difficult to obtain good conductivity. On the other hand, when the film thickness of the transparent conductive thin film is larger than 30 nm, when the transparent conductive thin film layer is patterned, it becomes difficult to make the optical characteristics of the portion having the transparent conductive thin film layer close to the portion not having the transparent conductive thin film layer.

  The layer structure of the transparent conductive thin film may be a single layer structure or a laminated structure of two or more layers. In the case of a transparent conductive thin film having a laminated structure of two or more layers, the metal oxides constituting each layer may be the same or different.

As a method for forming a transparent conductive thin film in the present invention, a vacuum vapor deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, and the like are known. Can be used as appropriate.
For example, in the case of the sputtering method, a normal sputtering method using an oxide target, a reactive sputtering method using a metal target, or the like is used. At this time, oxygen, nitrogen, or the like may be introduced as a reactive gas, or means such as ozone addition, plasma irradiation, or ion assist may be used in combination. In addition, a bias such as direct current, alternating current, and high frequency may be applied to the substrate as long as the object of the present invention is not impaired.

(Dielectric layer (protective layer) having a refractive index of 1.40 to 1.70)
In the present invention, a dielectric layer having a refractive index of 1.40 or more and 1.70 or less is a protective layer that is laminated to protect a transparent conductive thin film when a transparent conductive laminated film is used as a display member. This layer has both the purpose of increasing the capacitance change when touched with a finger or the like and improving the position input accuracy.
The dielectric layer having a refractive index of 1.40 to 1.70 or less, for _example, transparent metal oxide such as SiO 2, _Al 2 _{O 3} and composite metal oxides such as _SiO 2 _-Al 2 _{O 3,} acrylic, An organic material made of silicone or polyester resin is used.

(Optical characteristics of transparent conductive laminated film)
In the present invention, after patterning the transparent conductive thin film layer of the transparent conductive laminated film, in a state where a dielectric layer having a refractive index of 1.40 or more and 1.70 or less is laminated on the transparent conductive thin film layer side, It is important that the difference in optical properties between the portion having the transparent conductive thin film layer and the portion not having the transparent conductive thin film layer and that the reflectance is not too large. An acrylic adhesive layer having a refractive index of 1.52 is provided on the transparent conductive thin film side. The reflectance of a portion having a transparent conductive thin film layer and a portion having no transparent conductive thin film layer measured in a state where a biaxially oriented polyethylene terephthalate film having A4340 (thickness: 188 μm, manufactured by Toyobo Co., Ltd.) is bonded as a protective film It is preferable that the value satisfies the following formulas (1), (2), and (3).
0 ≦ | R1-R0 | ≦ 1.0 (1)
R1 ≦ 5.0 (2)
R0 ≦ 5.0 (3)
(R1: reflectivity of the film having a transparent conductive thin film layer,
R0: Reflectance of the film of the portion having no transparent conductive thin film layer)

(Transparent conductive laminated film with dielectric layer)
The transparent conductive laminated film with a dielectric layer of the present invention has the above refractive index on the transparent conductive thin film layer side of the transparent conductive laminated film obtained by patterning the transparent conductive thin film layer of the transparent conductive laminated film of the present invention. Is a transparent conductive laminated film with a dielectric layer in which dielectric layers of 1.40 to 1.70 are laminated.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples. In addition, the performance of the transparent conductive laminated film was measured by the following method.

(1) Reflectance In the integrating sphere measurement mode of Hitachi spectrophotometer U3500, the incident angle of the measurement light to the sample is set to 10 degrees, and a light shielding layer is applied to the back side of the transparent conductive laminated film sample using a commercially available black spray. The reflectance at a wavelength of 550 nm was measured in a state where there was no back surface reflection of the sample and no light was incident from the back surface side.
R1 and R0 in the formulas (1), (2) and (3) are printed on the transparent conductive laminated film with an etching resist, immersed in 1N hydrochloric acid, and further alkali (1N-sodium hydroxide aqueous solution). ) A 5 × 5 cm pattern was formed by immersion. A biaxially oriented polyethylene terephthalate film (A4340 manufactured by Toyobo Co., Ltd., thickness 188 μm) having an acrylic adhesive layer with a refractive index of 1.52 was bonded to the transparent conductive thin film side of the patterned transparent conductive laminated film as a protective film. The reflectance values of the portion having the transparent conductive thin film layer and the portion having no transparent conductive thin film layer measured in the state were measured.

(2) Surface resistance value Based on JIS-K7194, the surface resistance value of the transparent conductive thin film layer of a transparent conductive laminated film was measured by the 4-terminal method. As a measuring instrument, Lotest AMCP-T400 manufactured by Mitsubishi Oil Chemical Co., Ltd. was used.

(3) Visibility evaluation After an etching resist was printed on the transparent conductive laminated film, it was immersed in 1N hydrochloric acid, and further a 1 × 3 cm pattern was formed by immersion in an alkali (1N-sodium hydroxide aqueous solution). A biaxially oriented polyethylene terephthalate (hereinafter abbreviated as PET) film (A4340 manufactured by Toyobo Co., Ltd., thickness 188 μm) having an acrylic adhesive layer having a refractive index of 1.52 on the transparent conductive thin film side was bonded as a protective film. Using FMV-BIBLOLOOX T70M / T manufactured by Fujitsu Ltd., the screen was displayed in white, and a film on which a protective film was bonded was placed in front of it, and the appearance of patterning was evaluated from various angles.
○: Patterning is hardly seen.
Δ: Patterning is slightly visible.
X: Patterning is visible.

(4) Film thickness of composition gradient thin film layer and transparent conductive thin film layer A film sample piece obtained by laminating a composition gradient thin film layer and a transparent conductive thin film layer is cut into a size of 1 mm × 10 mm and embedded in an epoxy resin for an electron microscope. did. This was fixed to a sample holder of an ultramicrotome, and a cross-sectional thin section parallel to the short side of the embedded sample piece was produced. Next, in a section where the thin film of this section is not significantly damaged, a transmission electron microscope (manufactured by JEOL, JEM-2010) is used to obtain a photograph at an acceleration voltage of 200 kV and a bright field at an observation magnification of 10,000 times. The film thickness was determined from the photograph taken.

(5) Refractive index of the thin film layer used for the composition gradient thin film layer and the transparent conductive thin film layer The thin film layer used for the composition gradient thin film layer and the transparent conductive thin film layer were produced on glass (corning 7059) under the same film formation conditions. The sample was measured for refractive index at 550 nm using a spectroscopic ellipsometer (FE-5000, manufactured by Otsuka Electronics Co., Ltd.).

(6) Resistance between edge portions of transparent conductive thin film after patterning After etching resist is printed on the transparent conductive laminated film, it is immersed in 1N hydrochloric acid and further immersed in alkali (1N-sodium hydroxide aqueous solution). A pattern of 3 cm was formed. The resistance between the end portions (2.6 cm) of the pattern thus produced was measured.

[Example 1]
A mixed solvent of toluene / MEK (80/20: mass ratio) as a solvent was added to 100 parts by mass of a photopolymerization initiator-containing ultraviolet curable acrylic resin (manufactured by Dainichi Seika Kogyo Co., Ltd., Seika Beam EXF-01J). Was added so as to be 50% by mass, and stirred to dissolve uniformly to prepare a coating solution.

The prepared coating solution was applied to a biaxially oriented transparent PET film (Toyobo Co., Ltd., A4340, thickness 188 μm) having an easy-adhesion layer on both sides using a Meyer bar so that the coating thickness was 5 μm. . After drying at 80 ° C. for 1 minute, the coating film was cured by irradiating with ultraviolet rays (light quantity: 300 mJ / cm ² ) using an ultraviolet ray irradiation device (UB042-5AM-W type, manufactured by Eye Graphics Co., Ltd.). . Next, after a coating film was similarly provided on the opposite surface, a heat treatment was performed at 180 ° C. for 1 minute to reduce volatile components.

  Moreover, in order to expose the biaxially oriented transparent PET film on which the cured product layer was laminated in a vacuum, a rewinding process was performed in a vacuum chamber. The pressure at this time was 0.002 Pa, and the exposure time was 20 minutes. The temperature of the center roll was 40 ° C.

Next, a film composed of silicon (Si), oxygen (O), and nitrogen (N) elements was formed as a composition gradient thin film layer on the cured product layer. At this time, the pressure before sputtering was 0.0001 Pa, silicon was used as a target, and DC power was applied. Further, Ar gas was introduced as a discharge gas. The film was formed using a DC magnetron sputtering method in an atmosphere of 0.4 Pa while gradually decreasing the ratio of N ₂ and O ₂ gas (N ₂ / O ₂ ) with the film formation time. The center roll temperature was 0 ° C. and sputtering was performed.

  In addition, while constantly monitoring the nitrogen and oxygen partial pressure in the atmosphere with a sputter process monitor (manufactured by LEYBOLD INFICON, XPR2), a nitrogen and oxygen gas flowmeter is used so that the nitrogen and oxygen ratio in the thin film becomes a predetermined ratio Back to the foot. As described above, a composition gradient thin film layer made of Si, O, and N elements having a maximum refractive index of 1.95, a minimum refractive index of 1.48, and a thickness of 52 nm was deposited.

Next, a transparent conductive thin film made of indium-tin composite oxide was formed on the composition gradient thin film layer. At this time, the pressure before sputtering and 0.0001 Pa, indium oxide tin oxide as a target containing 10 mass% (Sumitomo Metal Mining Co., density 7.1 g / cm ³⁾ used to, the 2W / cm ² DC Power was applied. Further, Ar gas was flowed at 130 sccm and O ₂ gas was flowed at a flow velocity at which the surface resistance value was minimized, and a film was formed by DC magnetron sputtering in an atmosphere of 0.4 Pa. The center roll temperature was 10 ° C. and sputtering was performed.

  Also, while constantly monitoring the oxygen partial pressure of the atmosphere with a sputtering process monitor (manufactured by LEYBOLD INFICON, XPR2), an oxygen gas flow meter and a DC are provided so that the degree of oxidation in the indium-tin composite oxide thin film becomes constant I went back to power. As described above, a transparent conductive thin film made of an indium-tin composite oxide having a thickness of 20 nm and a refractive index of 1.99 was deposited.

[Example 2]
A transparent conductive laminated film was produced in the same manner as in Example 1 except that the target was changed from silicon to aluminum. In this manner, a composition gradient thin film layer composed of Al, O, and N elements having a maximum refractive index of 1.98, a minimum refractive index of 1.65, and a thickness of 59 nm was deposited.

Example 3
A transparent conductive laminated film was produced in the same manner as in Example 1 except that the target was changed to silicon-aluminum (30:70). In this manner, a composition gradient thin film layer composed of Si, Al, O, and N elements having a maximum refractive index of 1.96, a minimum refractive index of 1.55, and a thickness of 59 nm was deposited.

[Comparative Example 1]
A transparent conductive laminated film was produced in the same manner as in Example 1 except that the composition gradient thin film layer was not provided.

[Comparative Example 2]
A transparent conductive laminated film was produced in the same manner as in Example 1 except that the thickness of the composition gradient thin film layer was changed to 700 nm.

[Comparative Example 3]
A transparent conductive laminated film was produced in the same manner as in Example 1 except that the thickness of the composition gradient thin film layer was 15 nm.

[Comparative Example 4]
When producing the composition gradient thin film layer, two targets of silicon and titanium (Ti) were used as targets. Ar gas was introduced as a discharge gas, O ₂ gas was introduced as a reactive gas, and a film was formed using an AC magnetron sputtering method in an atmosphere of 0.4 Pa. Moreover, the center roll temperature was 0 degreeC, and the composition inclination thin film layer which the composition inclined in the thickness direction was produced by conveying a film along a center roll. As described above, a composition gradient thin film layer made of Ti, Si, and O elements having a maximum refractive index of 2.35, a minimum refractive index of 1.48, and a thickness of 41 nm was deposited. A transparent conductive laminated film was produced in the same manner as in Example 1 except for the composition gradient thin film layer.

From the results of Table 1, the transparent conductive laminated films described in Examples 1 to 3 that satisfy the scope of the present invention are not emphasized even when the transparent conductive thin film layer is patterned. When used in the front of a display body such as a liquid crystal display, it was excellent in visibility.
On the other hand, the transparent conductive laminated film according to Comparative Examples 1 to 4 in which the refractive index of the composition gradient thin film layer is not appropriate or the film thickness is not appropriate is visible because the difference between the patterned portion and the non-patterned portion is visible. Inferior.

  The transparent conductive laminated film of the present invention has a small difference in optical properties between the patterned portion and the non-patterned portion of the transparent conductive thin film layer, and has excellent visibility when placed on the front surface of a display body such as a liquid crystal display. It is particularly suitable as an electrode film for a capacitive touch panel.

It is explanatory drawing of the transparent conductive laminated film of this invention.

Explanation of symbols

10: Transparent conductive film 11: Transparent plastic film (base material)
12: Hardened material layer 13: Composition gradient thin film layer 14: Transparent conductive thin film layer 20: Dielectric layer

Claims (6)

  A transparent conductive laminated film in which a composition gradient thin film layer and a transparent conductive thin film layer are provided in this order on at least one surface of a substrate made of a transparent plastic film, the composition gradient thin film layer having a thickness of 20 to 500 nm, The refractive index of the inclined thin film layer varies in the thickness direction, the maximum value of the refractive index is 1.70 or more (refractive index of the transparent conductive thin film layer +0.30) or less, and the minimum value of the refractive index is 1.30 or more. 1. A transparent conductive laminated film, which is 1.65 or less.   The composition gradient thin film layer is an inorganic thin film layer composed of at least one element selected from Mg, Si, and Al and at least two elements selected from O, N, C, and F. Transparent conductive laminated film.   The transparent conductive laminated film according to claim 1 or 2, wherein the refractive index of the composition gradient thin film layer continuously decreases from the base material to the transparent conductive thin film layer side.   The transparent conductive laminated film according to claim 1, wherein the transparent conductive thin film layer comprises a metal oxide thin film containing indium. Transparent conductive thin film measured in a state where a biaxially oriented polyethylene terephthalate film having an acrylic adhesive layer having a refractive index of 1.52 is laminated on the transparent conductive thin film layer side of the transparent conductive laminated film patterned with the transparent conductive thin film layer The reflectance of the part which has a layer, and the part which does not have a transparent conductive thin film layer satisfy | fills following (1), (2), and (3) Formula, The one in any one of Claims 1-4 characterized by the above-mentioned. Transparent conductive laminated film.
0 ≦ | R1-R0 | ≦ 1.0 (1)
R1 ≦ 5.0 (2)
R0 ≦ 5.0 (3)
(R1: reflectivity of a film having a transparent conductive thin film layer, R0: reflectivity of a film having a transparent conductive thin film layer)   The refractive index is 1.40 or more and 1.70 or less on the transparent conductive thin film layer side of the transparent conductive laminated film obtained by patterning the transparent conductive thin film layer of the transparent conductive laminated film according to claim 1. A transparent conductive laminated film with a dielectric layer, wherein a dielectric layer is laminated.