JPWO2014115770A1 - Transparent conductive substrate and method for producing the same - Google Patents

Abstract

The object is to provide a transparent conductive film in which a transparent conductive film having a two-layer structure formed into a single layer is formed on a transparent film substrate, and further manufacturing a single layer of a two-layer transparent conductive film laminate Provide a method. A transparent conductive substrate in which a single layer and a crystalline transparent conductive film made of indium oxide containing an oxide of at least one or more kinds of 2 to 6 metal elements are formed on one side or both sides of a transparent substrate. The transparent conductive film is sequentially formed as two layers of a first amorphous transparent conductive film and a second amorphous transparent conductive film, and then the obtained transparent conductive film stack is heat-treated. The first amorphous transparent conductive film is different from the second amorphous transparent conductive film in that the total weight ratio of the oxides of 2 to 6-valent metal elements is different from that of the second amorphous transparent conductive film. The transparent conductive base material is characterized in that the total weight ratio of the oxides of 2 to 6 metal elements in the transparent conductive film is 16% by weight or less.

Description

  The present invention relates to a transparent conductive base material having a crystalline low-resistance transparent conductive film used for a capacitive touch panel, and a manufacturing method for forming a transparent conductive film by a sputtering method.

  Since the transparent conductive film has high conductivity and high transmittance in the visible light region, it is used for flat panel displays, solar cell electrodes, and the like. In particular, in recent years, capacitive touch panels have become widespread for smartphones and tablet PCs, and the usage is increasing in those applications.

  Capacitive touch panels can be broadly classified into those using a glass substrate and those using a film substrate when distinguished by the substrate. Among these, the film capacitive touch panel using a film base material is not only excellent in flexibility and workability, but also light in weight when enlarged, and excellent in impact resistance. Demand growth is remarkable. Under such circumstances, development of transparent conductive films suitable for film capacitive touch panels has been actively promoted.

  Many of the transparent conductive films used for the capacitive touch panel are not limited to film base materials, but are ITO (Indium-Tin-Oxide) films in which tin is added to indium oxide. Since a capacitive touch panel is required to have high visibility, it is necessary to make the ITO film, which is a transparent electrode, an extremely thin film. At the same time, the ITO film is required to exhibit a low electrical resistance while being an extremely thin film. For film capacitive touch panels, the thickness of the ITO film is set to 20 to 30 nm, and it is required to achieve a lower surface resistance value at that thickness, and it is proposed to provide a refractive index buffer on the surface. (See Patent Document 3). In the case of a device having a size larger than that of a smartphone, such as a tablet PC, a lower electric resistance tends to be required. In addition to this, the ITO film is required to be a crystalline film. In order to ensure the high environmental resistance and durability of the film capacitive touch panel, the ITO film is advantageously a crystalline film with less change in surface resistance over time.

  In many cases, a PET film having low heat resistance is used as the film substrate. Since the PET film has a glass transition temperature of about 80 ° C., generally, a hard coat layer made of an acrylic organic material or the like is formed on both surfaces thereof, and the heat resistance temperature is increased to about 150 ° C. for use. Therefore, in the method for producing an ITO crystal film, an amorphous film formed by sputtering is generally crystallized by heat treatment, but it is necessary to keep the heating temperature at 150 ° C. or less in the film formation and heat treatment.

  It is known that the ITO crystal film generally exhibits the lowest resistance when tin oxide is 10% by weight. However, in the capacitive touch panel, an ITO crystal film containing 10% by weight of tin oxide is not used. The reason is that the crystallization start temperature of the ITO film becomes higher as the amount of tin oxide increases. When the weight ratio of tin oxide is increased to 10% by weight, the PET film should be crystallized at a heat resistant temperature of 150 ° C. I can't. At the same time, crystallization becomes difficult as the film thickness decreases.

  As a method for solving the difficulty of crystallization of the ITO film, it has been proposed to provide a transparent conductive thin film having a two-layer structure on a film substrate.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-244771) discloses a thin film made of an indium-tin composite oxide having a small ratio of tin oxide from the film substrate side, and an indium / tin composite oxide having a large ratio of tin oxide on the thin film. It has been proposed to provide a thin film of material.

  Patent Document 2 (Japanese Patent Laid-Open No. 2012-1114070) discloses a transparent film for the purpose of providing a transparent conductive film having a transparent conductive thin film capable of shortening the crystallization time by the heat treatment described above. The transparent conductive film which has the transparent conductive thin film laminated body which consists of a specific transparent conductive thin film of at least 2 layers is described in the at least one surface of a base material. Each of the transparent conductive thin films is a crystalline film of an indium composite oxide containing indium oxide or an oxide of a tetravalent metal element, and on the surface side of the transparent conductive thin film laminate, The first transparent conductive thin film has a first transparent conductive thin film having an indium oxide or tetravalent metal element oxide ratio of more than 0 and not more than 6% by weight, from the surface side of the transparent conductive thin film laminate. Following the thin film, it has been proposed to have a second transparent conductive thin film in which the ratio of the oxide of the tetravalent metal element is larger than that of the first transparent conductive thin film.

  However, in any patent document, the total film thickness of the transparent conductive laminated film is limited to 20 to 30 nm as described above, and although less than half of the film thickness, There has been a problem that a thin film made of indium-tin composite oxide with a relatively small ratio of tin oxide having a relatively high surface resistance or a thin film with a small ratio of indium oxide or an oxide of a tetravalent metal element is occupied. Furthermore, there is a problem that the interface of the laminated film composed of at least two layers becomes a factor of high resistance.

  A thin film made of an amorphous indium composite oxide is formed by sputtering using an oxide sintered body (see Patent Document 4), but the interface of the transparent conductive laminated film can be eliminated. A method has not yet been found.

  Under such circumstances, on the premise of a manufacturing process in which an amorphous transparent conductive laminated film formed by sputtering is heat-treated and crystallized, it is sufficiently crystallized at a heating temperature of 150 ° C. or less even if the film thickness is thin. There has been a need for a single-layer transparent conductive film having a low resistance and a manufacturing method for obtaining the same.

JP 2006-244771 A JP 2012-1114070 A JP 2013-186530 A JP 2007-55841 A

  Therefore, the present invention aims to provide a transparent conductive base material having a transparent conductive film that is crystalline and has a low resistance used for a capacitive touch panel, and a manufacturing method for forming the transparent conductive film by a sputtering method. And

  As a result of intensive studies to solve the problems of the prior art described above, the present inventors have found that in Patent Documents 1 and 2, an indium-tin composite with a small proportion of tin oxide that is easy to crystallize but does not have a sufficiently low surface resistance value. A thin film made of an oxide or a thin film with a small proportion of oxide of indium oxide or tetravalent metal element (hereinafter referred to as thin film A) and an indium-tin composite with a large proportion of tin oxide that is difficult to crystallize but has a sufficiently low surface resistance The effect of the surface resistance value of the thin film A not being sufficiently low because it has a two-layer laminated structure combining a thin film made of an oxide or a thin film with a high proportion of oxide of a tetravalent metal element (hereinafter referred to as a thin film B), In addition, it has been found that a sufficiently low resistance cannot be obtained as a whole due to the influence of the interface between the thin film A and the thin film B. In order to solve these problems, long-distance diffusion of constituent element ions at the interface of the laminate is likely to occur by forming a two-layer amorphous transparent conductive film laminate on the substrate under specific conditions. And then heat-treating to form a single-layered two-layer structure, so that even when the film thickness is thin, it is sufficiently crystallized at a heating temperature of 150 ° C. or less, and a low-resistance transparent conductive laminated film can be obtained. The present invention has been completed.

That is, according to the first invention of the present invention, a single layer made of indium oxide or indium oxide containing an oxide of at least one kind of divalent to hexavalent metal element on one or both surfaces of a transparent substrate. And a transparent conductive substrate on which a crystalline transparent conductive film is formed,
The transparent conductive film is sequentially formed as two layers of a first amorphous transparent conductive film and a second amorphous transparent conductive film, and then the obtained transparent conductive film laminate is heat-treated. Formed,
The first amorphous transparent conductive film is different from the second amorphous transparent conductive film in that the total weight ratio of the oxides of divalent to hexavalent metal elements represented by the following formula (A) is A transparent conductive substrate is provided, wherein the total weight ratio of oxides of 2 to 6 metal elements in the crystalline transparent conductive film is 16% by weight or less.
{Total weight of oxide of 2 to 6 metal elements / (weight of indium oxide + total weight of oxide of 2 to 6 metal elements)} × 100 (%) Formula (A)

  According to the second invention of the present invention, in the first invention, the oxide of the divalent to hexavalent metal element is any one of zinc oxide, gallium oxide, tin oxide, titanium oxide, or tungsten oxide. A transparent conductive substrate is provided.

According to a third aspect of the present invention, in the first aspect, the first amorphous transparent conductive film is indium oxide represented by the following formula (B), or at least one or more types It consists of indium oxide containing 10% by weight or less of an oxide of a tetravalent metal element in a total weight ratio,
In addition, the second amorphous transparent conductive film contains an oxide of a tetravalent metal element in a total weight ratio that is greater than the total weight ratio of the first transparent conductive film and is 25% by weight or less. Consists of
Furthermore, the transparent conductive substrate which is a single layer and is crystalline contains at least one or more kinds of tetravalent metal element oxides in a total weight ratio of 5 to 16% by weight. Provided.
{Total weight of oxide of tetravalent metal element / (weight of indium oxide + total weight of oxide of at least one tetravalent metal element)} × 100 (%) Formula (B)

According to a fourth aspect of the present invention, in the first aspect, the first amorphous transparent conductive film is indium oxide represented by the following formula (B), or at least one or more types Comprising indium oxide containing a tetravalent metal element oxide in a total weight ratio of 25% by weight or less,
In addition, the second amorphous transparent conductive film contains an oxide of a tetravalent metal element in a total weight ratio that is less than the total weight ratio of the first transparent conductive film and is 10% by weight or less. Consists of
Furthermore, the transparent conductive substrate which is a single layer and is crystalline contains at least one or more kinds of tetravalent metal element oxides in a total weight ratio of 5 to 16% by weight. Provided.
{Total weight of oxide of tetravalent metal element / (weight of indium oxide + total weight of oxide of at least one tetravalent metal element)} × 100 (%) Formula (B)

  According to a fifth aspect of the present invention, there is provided the transparent conductive substrate according to the third or fourth aspect, wherein the tetravalent metal element oxide is tin oxide or titanium oxide. Provided.

  According to a sixth invention of the present invention, in any one of the first to fifth inventions, the total film thickness of the single-layer and crystalline transparent conductive film is 35 nm or less. A functional substrate is provided.

  According to the seventh invention of the present invention, in any one of the first to fifth inventions, the total film thickness of the single-layered crystalline transparent conductive film is 35 nm or less, and the first or second non-conductive film There is provided a transparent conductive substrate characterized in that the film thickness of at least one of the crystalline transparent conductive films is 10 nm or more.

  According to an eighth aspect of the present invention, in any one of the first to fifth aspects, the transparent substrate is a resin film. A transparent conductive substrate is provided.

  Furthermore, according to a ninth invention of the present invention, in any one of the third to fifth inventions, each of the first and second amorphous transparent conductive films is an oxide of a tetravalent metal element. The tin oxide is contained in an amount of 3% by weight or more, the total film thickness of the single-layer and crystalline transparent conductive film is 25 nm or less, and the surface resistance value is 125 Ω / □ or less. A transparent conductive substrate according to any one of the above is provided.

On the other hand, according to the tenth invention of the present invention, in any one of the first to ninth inventions, two layers of the first and second amorphous transparent conductive films are formed on one side or both sides of the transparent substrate. From the first step of sequentially forming the transparent conductive film laminate made of the above by sputtering film formation, and the second step of obtaining a single layer and a crystalline transparent conductive film by heat-treating the obtained transparent conductive film laminate A method for producing a transparent conductive substrate comprising:
In the first step, the oxygen partial pressure of the first amorphous transparent conductive film with respect to the optimum oxygen partial pressure of the first amorphous transparent conductive film, and the second amorphous transparent conductive film The average ratio of the oxygen partial pressure of the second amorphous transparent conductive film to the optimum oxygen partial pressure of the first and second amorphous transparent conductive films is 18% or more, and oxygen in the sputtering film formation of the first and second amorphous transparent conductive films At least one of the partial pressures is lower than the optimum oxygen partial pressure, and the oxygen partial pressure in sputtering deposition of the first amorphous transparent conductive film is sputtering deposition of the second amorphous transparent conductive film Equal to or greater than the partial pressure of oxygen in
In the second production process, a method for producing a transparent conductive substrate is provided, wherein the transparent conductive film laminate is formed into a single layer by heat treatment in an oxidizing atmosphere.

  According to the eleventh aspect of the present invention, in the tenth aspect, in the first manufacturing step, the oxygen partial pressure in the sputtering film formation of the first and second amorphous transparent conductive films is In either case, the oxygen partial pressure is lower than the optimum oxygen partial pressure, and the oxygen partial pressure in the sputtering film formation of the first amorphous transparent conductive film is higher than the oxygen partial pressure in the film formation of the second amorphous transparent conductive film. A method for producing the characteristic transparent conductive substrate is provided.

  According to a twelfth aspect of the present invention, in the tenth aspect, in the first step, in the first step, the first amorphous structure with respect to the optimum oxygen partial pressure of the first amorphous transparent conductive film The average ratio of the oxygen partial pressure of the transparent conductive film and the oxygen partial pressure of the second amorphous transparent conductive film to the optimum oxygen partial pressure of the second amorphous transparent conductive film is 18 to 91% Thus, there is provided a method for producing a transparent conductive substrate, characterized by performing sputtering film formation.

  Furthermore, according to the thirteenth invention of the present invention, in the tenth invention, the transparent conductivity characterized in that, in the second step, the volume ratio of oxygen in the heat treatment atmosphere is 20 to 100%. A method of manufacturing a substrate is provided.

  In the present invention, a thin film made of an indium-tin composite oxide with a small ratio of tin oxide that is easy to crystallize but does not have a sufficiently low surface resistance, and an indium / tin compound with a large ratio of tin oxide that has a sufficiently low surface resistance but is difficult to crystallize. A thin film made of a tin composite oxide or a thin film with a high proportion of oxide of a tetravalent metal element is formed under specific conditions, formed into a two-layer laminate, and then heat-treated to form a single layer. It becomes possible to eliminate the adverse effect of the interface, and as a result, a crystalline transparent conductive film exhibiting a sufficiently low resistance can be obtained.

  Moreover, since the transparent conductive film laminate having the two-layer structure can be formed into a single layer by a relatively low temperature heat treatment, the transparent conductive film manufacturing method of the present invention is a capacitive touch panel using a resin film as a base material. The present invention can be preferably applied to the production of

FIG. 1 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 9 is a schematic cross-sectional view showing a transparent conductive substrate according to an embodiment of the present invention. FIG. 10 is a graph showing the relationship between oxygen partial pressure and specific resistance in the sputtering film formation of a transparent conductive film made of indium oxide (containing 7.5% by weight of tin oxide). FIG. 11 is a photograph showing a cross-sectional TEM image of the transparent conductive film of Example 2. FIG. 12 is a photograph of electron diffraction of the transparent conductive film of Example 2. FIG. 13 is a graph showing the relationship between the film thickness direction of the transparent conductive film of Example 2 and the tin oxide content. FIG. 14 is a photograph showing a cross-sectional TEM image of the transparent conductive film of Comparative Example 5. FIG. 15 is a photograph of electron diffraction near the surface of the transparent conductive film of Comparative Example 5. FIG. 16 is a photograph of electron diffraction near the interface with the undercoat of the transparent conductive film of Comparative Example 5. FIG. 17 is a photograph of a cross-sectional TEM image of the transparent conductive film of Example 19. FIG. 18 is a photograph of electron diffraction of the transparent conductive film of Example 19. FIG. 19 is a graph showing the relationship between the film thickness direction of the transparent conductive film of Example 19 and the tin oxide content.

  Embodiments of the transparent conductive substrate and the method for producing the same according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to this.

1. Transparent conductive substrate The transparent conductive substrate of the present invention is composed of indium oxide or indium oxide containing at least one oxide of 2 to 6 metal elements on one or both sides of a transparent substrate. A transparent conductive substrate on which a single-layer and crystalline transparent conductive film is formed,
The transparent conductive film is sequentially formed as two layers of a first amorphous transparent conductive film and a second amorphous transparent conductive film, and then the obtained transparent conductive film laminate is heat-treated. Formed,
The first amorphous transparent conductive film is different from the second amorphous transparent conductive film in that the total weight ratio of the oxides of divalent to hexavalent metal elements represented by the following formula (A) is The total weight ratio of oxides of 2 to 6 metal elements in the crystalline transparent conductive film is 16% by weight or less.
{Total weight of oxide of 2 to 6 metal elements / (weight of indium oxide + total weight of oxide of 2 to 6 metal elements)} × 100 (%) Formula (A)

  As described above, in the conventional transparent conductive substrate, as in Patent Documents 1 and 2, a thin film of indium / tin composite oxide with a small proportion of tin oxide that is easily crystallized but does not have a sufficiently low surface resistance value, or oxidation An amorphous thin film (thin film A) with a small proportion of oxide of indium or tetravalent metal element and an indium-tin composite oxide with a large proportion of tin oxide that is difficult to crystallize but has a sufficiently low surface resistance High-quality thin films or amorphous thin films (thin film B) with a large proportion of oxides of tetravalent metal elements are combined. However, with such a two-layer structure, a sufficiently low resistance is obtained as a whole due to the influence of the thin film A that is easily crystallized but the surface resistance value is not sufficiently low, and the influence of the interface between the thin film A and the thin film B. I can't. Such a two-layered amorphous laminated structure is in a state where diffusion over a relatively long distance hardly occurs in crystallization to an indium oxide phase even if heat treatment is performed, and it is considered difficult to form a single layer. .

  Therefore, in the present invention, by forming a two-layer amorphous transparent conductive film laminate on a substrate under specific conditions, long-distance diffusion of constituent element ions at the laminate interface is likely to occur, The two-layer structure is made into a single layer by heat treatment, and thereby, even if the film thickness is thin, it is sufficiently crystallized at a heating temperature of 150 ° C. or less, and a low resistance transparent conductive laminated film is obtained.

  Next, preferable embodiment of the transparent conductive base material of this invention is described based on FIG. 1 and FIG. In the present invention, as shown in FIG. 1, a first amorphous transparent conductive film (21) and a second amorphous transparent film are sequentially formed on one or both surfaces of a transparent substrate (1). A transparent conductive film having a single layer and a low crystalline surface resistance as shown in FIG. 2, obtained by heat-treating an amorphous transparent conductive film laminate (2) comprising two conductive film layers (22). It is the transparent conductive film (11) in which the film | membrane (3) was formed.

  The amorphous transparent conductive film laminate (2) is composed of two layers of a first amorphous transparent conductive film (21) and a second amorphous transparent conductive film (22). All are made of indium oxide or indium oxide containing at least one oxide of 2 to 6 metal elements. The oxide of the divalent to hexavalent metal element is preferably at least one selected from the group consisting of zinc oxide, gallium oxide, tin oxide, titanium oxide, niobium oxide and tungsten oxide. In addition, the first amorphous transparent conductive film (21) and the second amorphous transparent conductive film (22) are represented by the formula (A) of an oxide of at least one or more kinds of 2 to 6 metal elements. It is preferable that the total weight ratios indicated by are different from each other.

  The single layer and crystalline transparent conductive film (3) comprises at least one or more kinds of oxides of 2 to 6 valent metal elements in a weight ratio represented by the formula (A) of more than 0% by weight and not more than 16% by weight. And more preferably 5 to 12% by weight. The total weight ratio of the oxides of at least one or more 2-6 valent metal elements contained in the single-layer and crystalline transparent conductive film (3) is the same as that of the first amorphous transparent conductive film (21) and the first transparent conductive film (21). It is determined by the value based on the film thickness and the total weight ratio (formula (A)) of each of the two amorphous transparent conductive films (22). The total weight ratio (formula (A)) of the oxides of at least one or more kinds of 2-6 hexavalent metal elements contained in the single layer and crystalline transparent conductive film (3) is a viewpoint that a low surface resistance value can be obtained. From more than 0% by weight and not more than 16% by weight, preferably 5 to 12% by weight. The film thickness of the single-layer and crystalline transparent conductive film (3) is preferably 35 nm or less, and more preferably 25 nm or less, considering the improvement in the visibility of the film capacitive touch panel.

  The two-layer amorphous transparent conductive film laminate is transformed into a single-layer and crystalline transparent conductive film by heat treatment. For example, the thin film structure is observed with a cross-sectional TEM image, and lattice fringes continue from the surface of the transparent conductive film to the interface with the underlying layer (such as an undercoat layer described later), and the transparent conductive film laminate 2 is formed. This is determined by not confirming the interface between the layers.

  Since the transparent conductive film after the heat treatment of the present invention is a polycrystal, if the two-layer state is maintained even after the heat treatment, the lattice stripes in the cross-sectional TEM image are not continuous, and the transparent conductive film laminate described above This is confirmed because the two-layer amorphous transparent conductive film interface constituting the film remains. The composition of the oxide of the 2-6 hexavalent metal element of the single layer and crystalline transparent conductive film is discontinuous at the interface between the two amorphous transparent conductive films constituting the transparent conductive film laminate. There may be. In particular, the total weight ratio of the oxides of at least one or more 2-6 valent metal elements contained in the first amorphous transparent conductive film and the second amorphous transparent conductive film (formula (A)) When the difference in the amount exceeds 6% by weight, discontinuity tends to occur, but the reduction of the surface resistance value, which is an object of the present invention, is achieved. In the case where the total weight ratio of the oxides of at least one or more 2-6 valent metal elements contained in either the first or second amorphous transparent conductive film is 2% by weight or less, It is more preferable that the composition of the oxide is continuously changed, and it is more preferable that the oxide is in a state close to homogenization.

Although it does not restrict | limit especially as said transparent base material (1), A non-alkali glass substrate, a synthetic quartz substrate, a resin substrate, a resin film substrate, etc. are mentioned. In applications that do not require transparency, various opaque substrates such as a silicon substrate, a metal plate such as stainless steel, a foil, or a polyimide film can be used. In particular, in applications that require transparency, a transparent film substrate (4) is preferable, and various resin films having transparency can be used.
For example, as a resin film, polyester resin, acetate resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, (meth) acrylic resin, polyvinyl chloride resin, poly Examples thereof include vinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and the like. Of these, polyester resins, polycarbonate resins, and polyolefin resins are particularly preferable. An acrylic hard coat layer may be appropriately formed on the surface of these resin films.

  In the present invention, among oxides of 2 to 6 metal elements contained in the transparent conductive film, oxides of tetravalent metal elements are preferable.

Next, another preferred embodiment of the present invention will be described with reference to FIGS. In the present invention, as shown in FIG. 4, the single-layered and crystalline transparent conductive film (6) formed on one or both sides of the transparent film base (4) is at least one tetravalent metal element. A transparent conductive film (12) containing 16% by weight or less of the above oxide in the total weight ratio represented by the formula (B).
{Total weight of oxide of tetravalent metal element / (weight of indium oxide + total weight of oxide of at least one tetravalent metal element)} × 100 (%) Formula (B)

  Here, the single-layer and crystalline transparent conductive film (6) once forms the amorphous transparent conductive film laminate (5) composed of two layers in FIG. 3 and heat-treats it under predetermined conditions. Can be obtained.

  In this case, in FIG. 3, the first amorphous transparent conductive film (51) constituting the two-layer amorphous transparent conductive film laminate (5) is composed of indium oxide or at least one or more kinds. The total weight ratio of the tetravalent metal element oxide is 10% by weight or less, and the oxide is preferably made of indium oxide containing 1 to 6% by weight of the tetravalent metal element oxide. Similarly, the second amorphous transparent conductive film (52) comprises at least one or more tetravalent metal element oxides in a total weight ratio (formula (B)) in the first amorphous transparent conductive film. It is preferably made of indium oxide containing more than 25% by weight exceeding the total weight ratio of the conductive film. The oxide of the tetravalent metal element is preferably either tin oxide or titanium oxide.

The single-layer and crystalline transparent conductive film (6) preferably contains at least one oxide of a tetravalent metal element in an amount of 16% by weight or less in terms of the total weight ratio represented by (Formula (B)). The total weight ratio of the oxides of at least one tetravalent metal element contained in the single-layer crystalline transparent conductive film (6) (formula (B)) is the first amorphous transparent conductive film ( 51) and the thickness of each of the second amorphous transparent conductive films (52) and a value based on the total weight ratio (formula (B)). The total weight ratio of the oxides of at least one tetravalent metal element (formula (B)) contained in the single-layer and crystalline transparent conductive film (6) is from the viewpoint that a low surface resistance value can be obtained. It is preferable that it is 16 weight% or less, More preferably, it is 5-12 weight%.
Further, the film thickness of the single-layered and crystalline transparent conductive film (6) is preferably 35 nm or less, more preferably 25 nm or less, considering the improvement in the visibility of the film capacitive touch panel. Furthermore, from the viewpoint of ease of crystallization, the film thickness of the first amorphous transparent conductive film (51) is more preferably 10 nm or more.

  Furthermore, another preferred embodiment of the present invention will be described with reference to FIGS.

In the present invention, as shown in FIG. 6, the single-layered and crystalline transparent conductive film (8) formed on one side or both sides of the transparent film base (4) is at least one tetravalent metal element. This is a transparent conductive film (13) containing 16% by weight or less of the above oxide in a total weight ratio represented by (formula (B)).
Here, the single layer and crystalline transparent conductive film (8) once forms the amorphous transparent conductive film laminate (7) having two layers in FIG. 5 and heat-treats it under predetermined conditions. Can be obtained.

  In this case, in FIG. 5, the first amorphous transparent conductive film (71) constituting the two-layer amorphous transparent conductive film laminate (7) has at least one tetravalent metal element. The total weight ratio (formula (B)) of the oxide is preferably indium oxide containing 25% by weight or less exceeding the total weight ratio of the second amorphous transparent conductive film (72) described below. Similarly, the second amorphous transparent conductive film (72) is made of indium oxide or an oxide of at least one tetravalent metal element in a total weight ratio represented by (formula (B)) of 10%. Indium oxide containing 1 to 6% by weight is preferable. The oxide of the tetravalent metal element is preferably selected from tin oxide or titanium oxide.

The single-layer and crystalline transparent conductive film (8) preferably contains 16% by weight or less of the oxide of at least one tetravalent metal element in the total weight ratio represented by the formula (B). The total weight ratio of the oxides of at least one tetravalent metal element contained in the single-layer and crystalline transparent conductive film (8) (formula (B)) is the first amorphous transparent conductive film ( 71) and a value based on the respective film thicknesses and the total weight ratio of the second amorphous transparent conductive film (72). The total weight ratio of the oxides of at least one tetravalent metal element (formula (B)) contained in the single layer and crystalline transparent conductive film (8) is that a low surface resistance value can be obtained. It is preferable that it is 25 weight% or less, More preferably, it is 5-12 weight%.
Further, the film thickness of the single-layer and crystalline transparent conductive film (8) is preferably 35 nm or less, more preferably 25 nm or less, considering the improvement in the visibility of the film capacitive touch panel. Furthermore, from the viewpoint of easy crystallization, the thickness of the second amorphous transparent conductive film (72) is preferably 10 nm or more.

  Moreover, you may form a single layer and a crystalline transparent conductive film on the single side | surface or both surfaces of the transparent film base material of FIGS. 1-6 through an undercoat layer. FIG. 7 shows a case where an amorphous transparent conductive film laminate (2) comprising two layers is formed on one side of a transparent film substrate (1) through an undercoat layer (9) as in FIG. ing. When this is heat-treated under predetermined conditions, as shown in FIG. 8, a single layer and crystalline transparent conductive film (6) is formed on one side of the transparent film substrate (1) as in FIG. 9).

  The thickness of the transparent film substrate (4) is preferably in the range of 2 to 200 μm, more preferably in the range of 2 to 120 μm, and more preferably 2 in the usage of the capacitive touch panel. It is preferable that it is -100micrometer. When the thickness of the transparent film substrate (4) is less than 2 μm, the mechanical strength as a film is insufficient, and the transparent film substrate (4) is rolled to form a transparent conductive film laminate (2, 5 or 7) In addition, the operation of continuously forming the undercoat layer (9) and the pressure-sensitive adhesive layer (10 in FIG. 9) may be difficult.

  The transparent substrate (1) or transparent film substrate (4) is subjected to an etching treatment or undercoating treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, etc. on the surface in advance. A transparent substrate (1) or a transparent film substrate (4) of an amorphous transparent conductive film laminate (2, 5 or 7) or an undercoat layer (9) comprising two layers provided thereon ) May be improved. In addition, before providing the two-layer amorphous transparent conductive film laminate (2, 5 or 7) or the undercoat layer (9), if necessary, dust removal and cleaning can be performed by solvent cleaning or ultrasonic cleaning. May be.

The arithmetic average roughness Ra of the transparent substrate (1) or the transparent film substrate (4) is 1.0 nm or less on the surface on which the transparent conductive film laminate (2, 5, or 7) is formed. Preferably, it is 0.7 nm or less, more preferably 0.6 nm or less, and particularly preferably 0.5 nm or less.
By reducing the surface roughness, the transparent conductive film laminate (2, 5 or 7) can be crystallized by heating for a relatively short time, and the crystallized single-layer and crystalline transparent conductive film (3, 6 or 8) can be low resistance. The lower limit of the arithmetic average roughness Ra of the transparent substrate surface is not particularly limited, but is preferably 0.1 nm or more from the viewpoint of imparting winding property when the substrate is wound into a roll. More preferably, it is 2 nm or more.

  In general, a filler or the like is added to the resin film for the purpose of avoiding deterioration in transportability and handling properties due to static electricity. For this reason, the arithmetic average roughness Ra of the surface often becomes higher than 1 nm. Therefore, for the purpose of setting the surface roughness of the transparent film substrate (4) within the above range, the amorphous transparent conductive thin film laminate (2, 5 or 7) of the transparent film substrate (4) is used. It is preferable that an undercoat layer (9) is formed on the surface on the side on which is formed. Thereby, the surface unevenness | corrugation of a transparent film base material (4) is relieve | moderated, and surface roughness can be made small.

  As the content of the oxide of the 2-6 hexavalent metal element increases, the amorphous transparent conductive thin film becomes difficult to crystallize, but as described above, the transparent film substrate (4) having a predetermined surface roughness. In the case of using, crystallization can be performed at a relatively low temperature or a short-time heat treatment.

The undercoat layer (9) shown in FIGS. 7 and 8 can be formed of an inorganic material, an organic material, or a mixture of an inorganic material and an organic material.
As the inorganic substance, for example, silicon oxide, magnesium fluoride, aluminum oxide and the like are preferably used. Examples of organic substances include organic substances such as acrylic resins, urethane resins, melamine resins, alkyd resins, and siloxane polymers. In particular, as the organic substance, it is desirable to use a thermosetting resin made of a mixture of a melamine resin, an alkyd resin, and an organosilane condensate.
The undercoat layer (9) can be formed using the above materials by a dry process such as a vacuum deposition method, a sputtering method, or an ion plating method, or a wet process (coating method). The undercoat layer (9) may be a single layer or a plurality of layers of two or more layers. In general, the thickness of the undercoat layer (9) (in the case of a plurality of layers, the thickness of each layer) is preferably 300 nm or less.

An adhesive layer can be provided on the other surface of the transparent substrate (1) or the transparent film substrate (4). In FIG. 9, an example which provided the transparent adhesive layer (10) and the transparent adhesive layer (10) in the surface of the one side of the transparent film base material (4) of FIG. 4 is shown.
The transparent pressure-sensitive adhesive layer (10) can be used without particular limitation as long as it has transparency. Specifically, for example, acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy systems, fluorine systems, natural rubbers, rubbers such as synthetic rubbers, etc. Those having the above polymer as a base polymer can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used from the viewpoint that it is excellent in optical transparency, exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is excellent in weather resistance and heat resistance.

The transparent pressure-sensitive adhesive layer (10) is scratch resistant to the transparent conductive film laminate (6) provided on one surface of the transparent substrate (1) or the transparent film substrate (4) due to its cushioning effect. And a touch point characteristic for touch panels, so-called pen input durability and surface pressure durability.
From the viewpoint of better exhibiting this function, it is desirable to set the elastic modulus of the transparent pressure-sensitive adhesive layer (10) in the range of 1 to 100 N / cm ² and the thickness in the range of 1 μm or more, usually 5 to 100 μm. When the thickness of the transparent pressure-sensitive adhesive layer (10) is less than 1 μm, the cushioning effect cannot be expected. Therefore, scratch resistance of the transparent conductive thin film laminate (2, 5 or 7) and pen input durability for touch panel use In addition, it tends to be difficult to improve surface pressure durability. On the other hand, if it is too thick, not only the transparency is impaired, but it is difficult to obtain good results in terms of formation of the transparent pressure-sensitive adhesive layer (10), bonding workability, and cost.

2. The manufacturing method of a transparent conductive base material The transparent conductive base material manufacturing method of this invention is transparent which consists of two layers of the 1st and 2nd amorphous transparent conductive film on the single side | surface or both surfaces of a transparent base material. It consists of a first step of sequentially forming the conductive film laminate by sputtering film formation and a second step of obtaining a single-layer and crystalline transparent conductive film by heat-treating the obtained transparent conductive film laminate.

2-1. First step (sputtering film formation)
The first step is a step of once forming a two-layer amorphous transparent conductive film laminate by sputtering on one or both sides of a transparent substrate.

  As a sputtering method to be applied, a DC magnetron sputtering method is preferable. From the viewpoint of realizing high-speed stable film formation, a dual magnetron sputtering method is also preferable. In addition, various magnetron sputtering methods such as a pulse magnetron sputtering method, an RF + DC magnetron sputtering method, and an RF magnetron sputtering method may be employed.

The target used for sputtering film formation is preferably an oxide sintered body target as exemplified in Patent Document 4. Metal or alloy targets are possible, but productivity and controllability are poor.
The oxide sintered compact target is oxidized according to the composition of the single layer and crystalline transparent conductive film obtained after the heat treatment, that is, the composition of the two layers of amorphous transparent conductive film constituting the transparent conductive film laminate. Indium oxide containing indium or an oxide of at least one or more divalent to hexavalent metal elements is selected. Moreover, when each oxide sintered compact target contains the oxide of a 2-6 hexavalent metal element, the content is suitably controlled according to each composition of the target two-layer amorphous transparent conductive film. Is done.

Sputtering film formation using a sintered oxide target must be performed in a sputtering apparatus chamber that has been evacuated until a high vacuum level is reached. When a film is formed in a low vacuum chamber, the remaining water molecules have an adverse effect.
Water molecules in the atmosphere at the time of sputtering film formation act to terminate dangling bonds in an amorphous film containing indium oxide as a main component, and thus prevent crystal growth of the indium oxide phase. For this reason, it is preferable that the partial pressure of water in the film forming atmosphere is small. The partial pressure of water in the sputtering film formation is preferably 0.1% or less, more preferably 0.07% or less with respect to the partial pressure of the argon gas. The specific value of the partial pressure of water is preferably 2 × 10 ⁻⁴ Pa or less, more preferably 1.5 × 10 ⁻⁴ Pa or less, and 1 × 10 ⁻⁴ Pa or less. Is preferred. In order to set the moisture pressure in the film formation to the above range, the inside of the sputtering apparatus chamber is set to 2 × 10 ⁻⁴ Pa or less, preferably 1.5 × so that the partial pressure of water is in the above range before starting the film formation. It is preferable to evacuate to 10 ⁻⁴ Pa or less, more preferably 1 × 10 ⁻⁴ Pa or less, and to make an atmosphere in which impurities such as moisture in the apparatus and organic gas generated from the substrate are removed.

The substrate temperature in the sputtering film formation preferably exceeds 100 ° C. By making the substrate temperature higher than 100 ° C., even an amorphous film made of indium oxide having a large oxide content of divalent to hexavalent metal is crystallized into an indium oxide phase in a heat treatment step described later. Is easily promoted, and a single-layer and crystalline transparent conductive film is obtained.
Furthermore, when the transparent conductive film laminate comprising two layers is heated and crystallized, from the viewpoint of forming a single-layer and crystalline transparent conductive film exhibiting low surface resistance, the substrate temperature is 120 More preferably, it is 130 degreeC or more, It is more preferable that it is 130 degreeC or more, It is especially preferable that it is 140 degreeC or more. The substrate temperature is preferably 250 ° C. or lower, but from the viewpoint of suppressing thermal damage to the transparent film substrate, 200 ° C. or lower is preferable, 180 ° C. or lower is more preferable, and 170 ° C. or lower is more preferable. A temperature of not higher than ° C is particularly preferred.

  Sputtering film formation using an oxide sintered compact target is performed by reactive sputtering in which a rare gas and an oxygen gas, which are inert gases, and preferably a sputtering gas composed of an argon gas and an oxygen gas is introduced. However, depending on the case, sputtering film formation in which only argon gas is introduced may be performed.

In the first step of the present invention, it is important to appropriately control the oxygen partial pressure of the sputtering gas.
Here, the relationship between the specific resistance of each of the first and second amorphous transparent conductive films and the oxygen partial pressure will be described with reference to FIG. FIG. 10 shows a change in specific resistance with respect to oxygen partial pressure of a transparent conductive film (hereinafter referred to as ITO 7.5) made of indium oxide containing 7.5% by weight of tin oxide having a thickness of 30 nm. In the sputtering film formation, the ratio of the DC output to the sputtering target area, that is, the DC power density is about 1.1 W / cm ² .

It can be seen that the specific resistance of ITO 7.5 shows a minimum value at an oxygen partial pressure of 6.9 × 10 ⁻³ Pa. Accordingly, in the present invention, the oxygen partial pressure at which the specific resistance of the amorphous transparent conductive film shows a minimum value is defined as “optimal oxygen partial pressure”. Further, when the oxygen partial pressure is less than the optimum oxygen partial pressure, the specific resistance increases as the oxygen partial pressure decreases. This region is defined as an “oxygen partial pressure insufficient region”. On the other hand, since the specific resistance increases as the oxygen partial pressure increases when the optimum oxygen partial pressure is exceeded, this region is defined as an “oxygen partial pressure excess region”. In general, in the manufacturing process of the transparent conductive film, the film is mostly formed in an optimum oxygen partial pressure or a slightly oxygen partial pressure excess region. The reason is to achieve both low specific resistance and high transmittance.

The “optimal oxygen partial pressure” tends to shift to a higher oxygen partial pressure side as the amount of tin oxide in ITO increases. However, the shift is performed under a film forming condition of about 1.1 W / cm ² with a low DC power density. Is not so noticeable. However, when the DC power density exceeds that, the shift becomes clear when the DC power density is about 3.4 W / cm ² , for example.

On the other hand, in the present invention, at least one of the oxygen partial pressures in the sputtering film formation of the first and second amorphous transparent conductive films is lower than the optimum oxygen partial pressure, and the first It is preferable that the oxygen partial pressure in the sputtering film formation of the amorphous transparent conductive film is equal to or higher than the oxygen partial pressure in the sputtering film formation of the second amorphous transparent conductive film.
More preferably, the oxygen partial pressure in the sputtering film formation of the first and second amorphous transparent conductive films is lower than the optimum oxygen partial pressure, and the first amorphous transparent conductive film The oxygen partial pressure in the sputtering film formation is larger than the oxygen partial pressure in the sputtering film formation of the second amorphous transparent conductive film.

  Furthermore, the average ratio of the oxygen partial pressure to the optimum oxygen partial pressure of the first amorphous transparent conductive film and the oxygen partial pressure to the optimum oxygen partial pressure of the second amorphous transparent conductive film is 18 to 91%. Sputtering film formation is preferably performed so as to be, more preferably 18 to 72%, and even more preferably when the average ratio is set to 18 to 56%. The average ratio of the oxygen partial pressure is the ratio of the oxygen partial pressure to the optimum oxygen partial pressure of the first amorphous transparent conductive film, and the optimum oxygen partial pressure of the second amorphous transparent conductive film. Means the arithmetic mean of the oxygen partial pressure ratios.

In the first step of the present invention, at least one of the oxygen partial pressures in the sputtering film formation of the first and second amorphous transparent conductive films is lower than the optimum oxygen partial pressure, and The oxygen partial pressure when the first amorphous transparent conductive film is formed by sputtering is equal to or higher than the oxygen partial pressure when the second amorphous transparent conductive film is formed by sputtering. Set and form sputtering film.
This is characterized by sputtering film formation in an oxygen partial pressure deficient region, unlike the manufacturing process of the general transparent conductive film exemplified in FIG. Taking ITO 7.5 as an example, for example, the oxygen partial pressure for forming the first amorphous transparent conductive film (ITO 7.5) is 6.3 × 10 ⁻³ Pa (about 91% of the optimum oxygen partial pressure). When set to, the oxygen partial pressure when forming the second amorphous transparent conductive film is set to be lower than 6.3 × 10 ⁻³ Pa and lower than the optimum oxygen partial pressure.
Furthermore, in the present invention, it is preferable to set the oxygen partial pressure of the first amorphous transparent conductive film to be the same as or higher than the oxygen partial pressure of the second amorphous transparent conductive film. The ratio of the oxygen partial pressure of the second amorphous transparent conductive film to the oxygen partial pressure of the first amorphous transparent conductive film is more preferably 85% or less.

  In this way, by forming a two-layer amorphous transparent conductive film laminate in an oxygen partial pressure deficient region, the state in which the oxygen content of the transparent conductive film laminate is significantly reduced is unbalanced. Can be obtained. Subsequently, when the transparent conductive film stack is heat-treated in an oxidizing atmosphere, for example, an atmosphere having an oxygen volume ratio of 20 to 100% in a second manufacturing process described later, the oxygen partial pressure inside and outside the transparent conductive film stack is determined. The oxygen difference is increased, and oxygen diffusion is activated even at a low heat treatment temperature of 200 ° C. or less particularly in a transparent film substrate. In connection with this, it is guessed that the spreading | diffusion of the 2-6 hexavalent metal element which comprises an oxide, especially tetravalent tin and titanium activates.

  Further, in the first step, the first and second amorphous transparent conductive films constituting the transparent conductive film laminate are optimally used for the first and second amorphous transparent conductive films. Sputtering is preferably performed by setting the average ratio to 18 to 91% with respect to the oxygen partial pressure, more preferably 18 to 72%, and particularly preferably 18 to 56%. This makes it possible to crystallize the single-layer and crystalline transparent conductive film formed on the transparent substrate of the present invention at a lower temperature or in a shorter time, or to lower the surface resistance.

Further, another embodiment of the present invention will be described in detail. In this embodiment, in the first step, the first amorphous transparent conductive film constituting the transparent conductive film laminated body is set to an optimum oxygen partial pressure of the first amorphous transparent conductive film. Sputter deposition is performed at an oxygen partial pressure of 60 to 122%, and the second amorphous transparent conductive film layer is formed with respect to the optimum oxygen partial pressure of the second amorphous transparent conductive film. It is preferable to set the oxygen partial pressure to 22 to 65% and perform the sputtering film formation. The oxygen partial pressure of the first amorphous transparent conductive film is set to 60 to 122% with respect to the optimum oxygen partial pressure. The ratio of 100% or more is preferably when the ratio of the DC power to the target area in sputtering film formation, that is, the DC power density is 1.4 W / cm ² or less.
In the present invention, the ratio of the first amorphous transparent conductive film to the optimum oxygen partial pressure and the second amorphous transparent conductive film are promoted for promoting the formation of a single layer of the transparent conductive film laminate. It is preferable that the film is formed by sputtering so that the difference from the ratio to the optimum oxygen partial pressure is 3% or more, more preferably 5% or more, and further more preferably 10% or more. Preferably, it is 30% or more.

  Further, in the present invention, in order to crystallize a single-layer and crystalline transparent conductive film formed on a transparent substrate at a low temperature or in a short time, or to further reduce the surface resistance, It is effective to form the second amorphous transparent conductive film located on the surface side in the oxygen partial pressure insufficient region.

  As described above, by setting the oxygen content of the two-layer amorphous transparent conductive film laminate to a significantly reduced state, diffusion of oxygen is activated, and the oxide is formed together with the 2-6 valences. Although diffusion of metal elements, particularly tin and titanium, is activated, in the present invention, the oxygen content of only the second amorphous transparent conductive film located on the surface side of the transparent conductive film laminate is reduced. In some cases, a more remarkable effect can be obtained.

2-2. Second step (heat treatment)
Next, the transparent conductive film laminated body in the present invention is heat-treated in an oxidizing atmosphere, particularly an atmosphere containing oxygen, in the second step.
It is preferable to set the volume ratio of oxygen contained in the heat treatment atmosphere to 20 to 100%. The oxygen volume ratio is more preferably set to 20 to 80%. This lower limit of 20% refers to the atmospheric atmosphere. That is, an atmosphere having a higher oxygen volume ratio than the air atmosphere is preferable. Therefore, in the second step, the two-layer amorphous transparent conductive film stack formed in the predetermined oxygen partial pressure deficient region in the first step is heat-treated in an atmosphere having a relatively high oxygen ratio. Thus, a single-layer and crystalline transparent conductive film can be obtained.

  It is preferable that the temperature of heat processing is the range of the heat resistance of a transparent base material. From the viewpoint of reducing the thermal load in the production process, 250 ° C. or lower is preferable. Moreover, from a viewpoint of suppressing the thermal damage to a transparent film base material, 100-200 degreeC is preferable, 120-150 degreeC is more preferable, and 130-150 degreeC is further more preferable. Although it depends on the type of the substrate, the time is 30 to 120 minutes for a resin film.

  Preferred embodiments of the present invention will be described below as examples, but the present invention is not limited to the examples.

1. Sample Preparation Conditions Sample preparation conditions in the examples of the present invention and comparative examples will be described in detail below.

<Film formation>
The amorphous transparent conductive film is formed using a general batch-type sputtering apparatus or a winding-type sputtering apparatus with a DC power of sputtering per target area, that is, a DC power density of 1.1 W / cm ² ( It implemented as Examples 1-12 and 21-25, Comparative Examples 1-7) or 3.4 w / cm < ² > (Examples 13-20).

<Heat treatment>
The heat treatment is performed in an atmosphere of air (oxygen volume ratio 20%), oxygen (oxygen volume ratio 100%) or nitrogen (oxygen volume ratio 0%) using a heat circulation oven or a heat treatment furnace capable of controlling the atmosphere, and the temperature is set. It was carried out at 150 ° C. with the time controlled to 30 to 120 minutes. Table 1 summarizes the details of the sample preparation conditions.

2. Measurement method The transparent conductive substrates obtained in Examples and Comparative Examples were evaluated by the following methods. Table 2 shows the evaluation results.

<Film thickness>
The film thickness of the undercoat layer and the transparent conductive film was measured by a stylus method using a surface shape measuring device Alpha-Step IQ manufactured by Tencor.

<Surface resistance value and specific resistance value>
The surface resistance value and the specific resistance value of the transparent conductive film were measured by a 4-terminal 4-probe method using a resistivity meter Loresta EP MCP-T360 manufactured by Mitsubishi Analitech.

<Crystallization>
The presence or absence of crystallization of the transparent conductive film was confirmed by thin film X-ray diffraction measurement using X-Pert PRO made by Panalical.

<Single layer>
As for the formation of a single layer of the transparent conductive film, the cross-sectional structure of the transparent conductive film after heat treatment is observed with a TEM using a transmission electron microscope apparatus HF-2200 (TEM) manufactured by Hitachi High-Tech. It confirmed with the presence or absence of the interface originating in the electrically conductive film laminated body. At the same time, the composition distribution in the thickness direction of the transparent conductive film crystallized by heat treatment was examined using a NORAN EDS apparatus VANTAGE.

Example 1
As a transparent film substrate, a polyethylene terephthalate film (trade name: 50KBCHABB, hereinafter referred to as PET film) having a thickness of 50 μm and having hard coat (hereinafter referred to as HC) layers formed on both surfaces made by Kimoto was used. A silicon oxide film was formed as an undercoat layer on one surface of the film base so as to have a thickness of 30 nm.

On the undercoat layer, a thin film made of indium oxide containing 2% by weight of tin oxide as a first amorphous transparent conductive film, and tin oxide 7% as a second amorphous transparent conductive film in order. A thin film (ITO 7.5) made of indium oxide containing 0.5 wt% was formed by sputtering to form a two-layer amorphous transparent conductive film laminate.
Prior to the formation of the above-described two-layer amorphous transparent conductive film laminate, the optimum oxygen partial pressures of the first and second amorphous transparent conductive films were examined. In 1 W / cm < ² >, all were 6.9 * 10 < ^-3 > Pa. The total gas pressure of the sputtering gas composed of a mixed gas of argon and oxygen was 0.3 Pa.

Therefore, in this example, the oxygen partial pressures for forming the first and second amorphous transparent conductive films were the same, and the oxygen partial pressure deficient region was 2.1 × 10 ⁻³ Pa. These oxygen partial pressures are 30% in average ratio with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.

The temperature of the film substrate is stably maintained at 150 ° C., and the ultimate vacuum in the sputtering apparatus chamber is at least 1.0 to 2.0 × 10 ⁻⁴ Pa or less. After confirmation, a film was formed by introducing a sputtering gas composed of argon and oxygen so as to achieve one of the above oxygen partial pressures. The first and second amorphous transparent conductive films are adjusted to have a film thickness of 10 nm and 12 nm, respectively, and the total film thickness of the two-layer amorphous transparent conductive film stack is 22 nm. It was.

A transparent film substrate in which an amorphous transparent conductive film laminate composed of two layers is formed on the undercoat layer, that is, the transparent conductive substrate is taken out from the sputtering apparatus chamber, and then heated in a hot air circulation oven. An atmospheric heat treatment at 150 ° C. was performed for 60 minutes. The oxygen volume ratio in the atmosphere is 20%.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Examples 2 to 4)
In Example 1, the oxygen partial pressures for forming the first and second amorphous transparent conductive films were the same and were set to 2.1 × 10 ⁻³ Pa in the oxygen partial pressure insufficient region. The pressure was set to 3.0 × 10 ⁻³ Pa (Example 2), 4.5 × 10 ⁻³ Pa (Example 3), and 6.3 × 10 ⁻³ Pa (Example 4). A transparent conductive substrate was produced in the same manner as in Example 1. These oxygen partial pressures are 43%, 65%, and 91% in average ratios when the first and second amorphous transparent conductive films are both at the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Examples 5 and 6)
When forming the first amorphous transparent conductive film, the oxygen partial pressure is set to an optimum oxygen partial pressure of 6.9 × 10 ⁻³ Pa (Examples 5 and 6), and the second amorphous transparent conductive film is used. Example 1 except that the oxygen partial pressure was changed to 1.5 × 10 ⁻³ Pa (Example 5) and 3.0 × 10 ⁻³ Pa (Example 6) in the oxygen partial pressure deficient region. A transparent conductive substrate was prepared.
The oxygen partial pressure of the first amorphous transparent conductive film is 100% (Examples 5 and 6) with respect to the optimum oxygen partial pressure. The oxygen partial pressure is 22% (Example 5) and 43% (Example 6) with respect to the optimum oxygen partial pressure, and both the first and second amorphous transparent conductive films are at the optimum oxygen partial pressure. For some cases, the average ratio is 61% and 72%.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Examples 7 to 9)
The first amorphous transparent conductive film is formed into a thin film made of indium oxide containing 7.5% by weight of tin oxide having a thickness of 12 nm, and the second amorphous transparent conductive film is oxidized to a thickness of 10 nm. A thin film made of indium oxide containing 2% by weight of tin was used, and a transparent conductive substrate was produced in the same manner as in Example 1.
That is, the first amorphous transparent conductive film and the second amorphous transparent conductive film were made upside down in the first to fourth embodiments, and the oxygen of the first amorphous transparent conductive film The optimum partial pressure of oxygen is 6.9 × 10 ⁻³ Pa (Examples 7 and 8), and the oxygen partial pressure excess region is 8.4 × 10 ⁻³ Pa (Example 9). Except that the oxygen partial pressure of the transparent conductive film was 1.5 × 10 ⁻³ Pa (Example 7) and 3.0 × 10 ⁻³ Pa (Examples 8 and 9) in the oxygen partial pressure deficient region, A transparent conductive substrate was produced in the same manner as in Example 1.
The oxygen partial pressure of the first amorphous transparent conductive film is 100% (Examples 7 and 8) and 122% (Example 9) with respect to the optimum oxygen partial pressure. The oxygen partial pressure of the amorphous transparent conductive film is 22% (Example 7) and 43% (Examples 8 and 9) with respect to the optimum oxygen partial pressure. The average ratio is 61%, 72%, and 83% with respect to the case where the transparent conductive film has an optimal oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Examples 10 and 11)
The first amorphous transparent conductive film is formed into a thin film made of indium oxide containing 3.3% by weight of tin oxide with a thickness of 15 nm, and the second amorphous transparent conductive film is oxidized with a thickness of 10 nm. The thin film was made of indium oxide containing 10% by weight of tin.
When the optimum oxygen partial pressure of the second amorphous transparent conductive film was examined, it was 6.9 × 10 ⁻³ Pa at a DC power density of 1.1 W / cm ² . The oxygen partial pressure of the first amorphous transparent conductive film was 3.0 × 10 ⁻³ Pa (Example 10) in the oxygen partial pressure deficient region and the optimum oxygen partial pressure 6.9 × 10 ⁻³ Pa (implemented). Example 11), except that the oxygen partial pressure of the second amorphous transparent conductive film was changed to 3.0 × 10 ⁻³ Pa (Examples 10 and 11) in the oxygen partial pressure insufficient region. A transparent conductive substrate was prepared in the same manner as in 1.
The oxygen partial pressure of the first amorphous transparent conductive film is 43% (Example 10) and 100% (Example 11) with respect to the optimum oxygen partial pressure. The oxygen partial pressure of the transparent conductive film is 43% (Examples 10 and 11) with respect to the optimum oxygen partial pressure, and both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure. The average ratio is 43% and 72%.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 12)
The first amorphous transparent conductive film is a thin film made of indium oxide containing 10% by weight of tin oxide having a thickness of 10 nm. The second amorphous transparent conductive film is made of tin oxide having a thickness of 15 nm. The oxygen partial pressure of the first amorphous transparent conductive film is changed to a thin film made of indium oxide containing 3.3 wt%, and the optimal partial pressure of oxygen is 6.9 × 10 ⁻³ Pa, the second A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4 except that the oxygen partial pressure of the amorphous transparent conductive film was changed to 3.0 × 10 ⁻³ Pa in the oxygen partial pressure deficient region. .
The oxygen partial pressure of the first amorphous transparent conductive film is 100% of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. The average ratio is 72% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 13)
The first amorphous transparent conductive film is made of indium oxide containing 21% by weight of tin oxide having a thickness of 20 nm, and the second amorphous transparent conductive film is made of indium oxide having a thickness of 15 nm. A transparent conductive substrate was produced in the same manner as in Examples 1 to 4 except that the thin film was changed to a thin film and the DC power density was changed to 3.4 W / cm ² .
When the optimum oxygen partial pressures of the first and second amorphous transparent conductive films were examined, they were 1.5 × 10 ⁻² Pa and 9.0 × 10 ⁻³ Pa, respectively. The oxygen partial pressure of the first amorphous transparent conductive film is 60% with respect to the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is with respect to the optimum oxygen partial pressure. 30%, and the average ratio is 45% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 14)
The first amorphous transparent conductive film is made of indium oxide containing 25% by weight of tin oxide having a thickness of 20 nm, the second amorphous transparent conductive film is made of tin oxide having a thickness of 15 nm. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4, except that the thin film was made of indium oxide containing 3.3 wt%, and the DC power density was changed to 3.4 W / cm ² .
When the optimum oxygen partial pressures of the first and second amorphous transparent conductive films were examined, they were 1.5 × 10 ⁻² Pa and 9.0 × 10 ⁻³ Pa, respectively. The oxygen partial pressure of the first amorphous transparent conductive film is 60% with respect to the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is with respect to the optimum oxygen partial pressure. 30%, and the average ratio is 45% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 15)
The first amorphous transparent conductive film is a thin film made of indium oxide containing 10% by weight of tin oxide having a thickness of 10 nm. The second amorphous transparent conductive film is made of tin oxide having a thickness of 20 nm. A transparent conductive substrate was produced in the same manner as in Examples 1 to 4, except that the thin film was made of indium oxide containing 7.5% by weight, and the DC power density was changed to 3.4 W / cm ² .
When the optimum oxygen partial pressures of the first and second amorphous transparent conductive films were examined, both were 1.5 × 10 ⁻² Pa. The oxygen partial pressure of the first amorphous transparent conductive film is 60% of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 50% with respect to the partial pressure, and the average ratio is 55% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 16)
The first amorphous transparent conductive film is formed into a thin film made of indium oxide containing 7.5% by weight of tin oxide having a thickness of 10 nm, and the second amorphous transparent conductive film is oxidized to a thickness of 20 nm. Implemented except that it was changed to a thin film composed of indium oxide containing 7.5% by weight of tin, that is, a film configuration having the same composition as that of Example 15 and that the DC power density was changed to 3.4 W / cm ^2. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4.
The oxygen partial pressure of the first amorphous transparent conductive film is 60% of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 50% with respect to the partial pressure, and the average ratio is 55% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 17)
The first amorphous transparent conductive film is a thin film made of indium oxide containing 10% by weight of tin oxide having a thickness of 10 nm. The second amorphous transparent conductive film is made of tin oxide having a thickness of 25 nm. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4 except that the direct current power density was changed to 3.4 W / cm ² in a thin film made of indium oxide containing 10% by weight.
The oxygen partial pressure of the first amorphous transparent conductive film is 60% of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 50% with respect to the partial pressure, and the average ratio is 55% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 18)
The first amorphous transparent conductive film is a thin film made of indium oxide containing 10% by weight of tin oxide having a thickness of 10 nm. The second amorphous transparent conductive film is made of tin oxide having a thickness of 15 nm. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4, except that the thin film was made of indium oxide containing 3.3 wt%, and the DC power density was changed to 3.4 W / cm ² .
The optimum oxygen partial pressures of the first and second amorphous transparent conductive films were 1.5 × 10 ⁻² Pa and 9.0 × 10 ⁻³ Pa, respectively, as described in Examples 14 and 15. It was. The oxygen partial pressure of the first amorphous transparent conductive film is 40% of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 33% with respect to the partial pressure, and the average ratio is 37% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 19)
The first amorphous transparent conductive film is made of indium oxide containing 10% by weight of tin oxide having a thickness of 15 nm, the second amorphous transparent conductive film is made of tin oxide having a thickness of 10 nm. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4, except that the thin film was made of indium oxide containing 3.3 wt%, and the DC power density was changed to 3.4 W / cm ² .
Since only the film thickness configuration of Example 18 was changed, the optimum oxygen partial pressures of the first and second amorphous transparent conductive films were 1.5 × 10 ⁻² Pa and 9.0 × 10 respectively. ^-3 Pa. Similar to Example 18, the oxygen partial pressure of the first amorphous transparent conductive film was 40% of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film was Is 33% with respect to the optimum oxygen partial pressure, and 37% in average ratio with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 20)
The first amorphous transparent conductive film is a thin film made of indium oxide containing 10% by weight of tin oxide having a thickness of 10 nm. The second amorphous transparent conductive film is made of tin oxide having a thickness of 15 nm. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4, except that the thin film was made of indium oxide containing 3.3 wt%, and the DC power density was changed to 3.4 W / cm ² .
The optimal oxygen partial pressures of the first and second amorphous transparent conductive films are 1.5 × 10 ⁻² Pa and 9.0 × 10 ⁻³ Pa, respectively, as in Example 18. The oxygen partial pressure of the first amorphous transparent conductive film is 20% with respect to the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. The average ratio is 17% with respect to the case where the first and second amorphous transparent conductive films are both at the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 21)
The first amorphous transparent conductive film is a thin film made of indium oxide containing 12% by weight of tin oxide having a thickness of 10 nm. The second amorphous transparent conductive film is made of titanium oxide having a thickness of 15 nm. A transparent conductive substrate was produced in the same manner as in Examples 1 to 4 except that the thin film was made of indium oxide containing 1% by weight.
When the optimum oxygen partial pressure of the first and second amorphous transparent conductive films was examined, it was found to be 8.1 × 10 ⁻³ Pa at a DC power density of 1.1 W / cm ² . The oxygen partial pressure of the first amorphous transparent conductive film is 70% with respect to the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 41% with respect to the partial pressure, and the average ratio is 56% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 22)
The first amorphous transparent conductive film is made of indium oxide containing 12% by weight of tin oxide having a thickness of 10 nm, and the second amorphous transparent conductive film is made of gallium oxide having a thickness of 15 nm. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4 except that the thin film was made of indium oxide containing 1.5% by weight.
The optimum oxygen partial pressure of the first amorphous transparent conductive film at a DC power density of 1.1 W / cm ² is 8.1 × 10 ⁻³ Pa, which is the same as in Example 21, and the ^second amorphous transparent conductive film When the optimum oxygen partial pressure of the conductive film was examined, it was 7.5 × 10 ⁻³ Pa. The oxygen partial pressure of the first amorphous transparent conductive film is 70% with respect to the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 40% with respect to the partial pressure, and the average ratio is 55% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 23)
The first amorphous transparent conductive film is a thin film made of indium oxide containing 12% by weight of tin oxide having a thickness of 10 nm, and the second amorphous transparent conductive film is made of tungsten oxide having a thickness of 15 nm. A transparent conductive substrate was produced in the same manner as in Examples 1 to 4 except that the thin film was made of indium oxide containing 1% by weight.
The optimum oxygen partial pressure of the first amorphous transparent conductive film at a DC power density of 1.1 W / cm ² is 8.1 × 10 ⁻³ Pa, which is the same as in Example 21, and the ^second amorphous transparent conductive film When the optimum oxygen partial pressure of the conductive film was examined, it was 6.0 × 10 ⁻³ Pa. The oxygen partial pressure of the first amorphous transparent conductive film is 70% with respect to the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 35% with respect to the partial pressure, and the average ratio is 53% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 24)
The first amorphous transparent conductive film is made of a thin film made of indium oxide containing 12% by weight of tin oxide having a thickness of 10 nm, the second amorphous transparent conductive film is made of zinc oxide having a thickness of 15 nm. A transparent conductive substrate was prepared in the same manner as in Examples 1 to 4, except that the thin film was made of indium oxide and contained 1% by weight.
The optimum oxygen partial pressure of the first amorphous transparent conductive film at a DC power density of 1.1 W / cm ² is 8.1 × 10 ⁻³ Pa, which is the same as in Example 21, and the ^second amorphous transparent conductive film When the optimum oxygen partial pressure of the conductive film was examined, it was 7.5 × 10 ⁻³ Pa. The oxygen partial pressure of the first amorphous transparent conductive film is 70% with respect to the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 40% with respect to the partial pressure, and the average ratio is 55% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Example 25)
A transparent conductive substrate was produced in exactly the same manner as in Example 8, except that the atmosphere and time for heat treatment of the obtained amorphous transparent conductive film laminate were changed to oxygen and 30 minutes. In this case, the oxygen volume ratio of the heat treatment atmosphere is 100%.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Comparative Examples 1-4)
The oxygen partial pressure of the first amorphous transparent conductive film is set to 6.0 × 10 ⁻⁴ Pa (Comparative Example 1) in the region where oxygen partial pressure is insufficient, and the optimal oxygen partial pressure is 6.9 × 10 ⁻³ Pa (Comparative Example). 2), 8.4 × 10 ⁻³ Pa (Comparative Example 3) and 9.0 × 10 ⁻³ Pa (Comparative Example 4) in the oxygen partial pressure excess region, oxygen content of the second amorphous transparent conductive film The pressure was 6.0 × 10 ⁻⁴ Pa (Comparative Example 1) in the oxygen partial pressure deficient region, the optimal oxygen partial pressure 6.9 × 10 ⁻³ Pa (Comparative Example 2), and the oxygen partial pressure excessive region 8.4 ×. A transparent conductive substrate was produced in the same production process as in Examples 1 to 4 except that the pressure was changed to 10 ⁻³ Pa (Comparative Examples 3 and 4).
In this case, the DC power density was 1.1 W / cm ^{2 under the} same conditions as in Examples 1 to 4. The oxygen partial pressure of the first amorphous transparent conductive film is 9% (Comparative Example 1), 100% (Comparative Example 2), 122% (Comparative Example 3) with respect to the optimum oxygen partial pressure. And the oxygen partial pressure of the second amorphous transparent conductive film is 9% (Comparative Example 1), 100% (Comparative Example 2), 122% (Comparative Examples 3 and 4), and 9%, 100%, 122%, and 126 in average ratios when the first and second amorphous transparent conductive films are both at the optimum oxygen partial pressure. %.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Comparative Example 5)
The first amorphous transparent conductive film is made of indium oxide containing 2% by weight of tin oxide having a thickness of 15 nm, the second amorphous transparent conductive film is made of tin oxide having a thickness of 10 nm. A transparent conductive substrate was prepared by changing to a thin film made of indium oxide containing 40% by weight.
In this case, the DC power density was 1.1 W / cm ^{2 under the} same conditions as in Examples 1 to 4. Prior to the formation of the two-layer amorphous transparent conductive film laminate, the optimum oxygen partial pressure of the second amorphous transparent conductive film was examined. As a result, 1.2 × 10 ⁻² Pa was obtained. Met. Accordingly, the oxygen partial pressure of the first amorphous transparent conductive film is 6.9 × 10 ⁻³ Pa of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is oxygen It was set to 9.0 × 10 ⁻³ Pa in the partial pressure insufficient region. A transparent conductive substrate was produced in the same manner as in Example 1 except for the conditions described above. The oxygen partial pressure of the first amorphous transparent conductive film is 100% of the optimum oxygen partial pressure, and the oxygen partial pressure of the second amorphous transparent conductive film is the optimum oxygen partial pressure. It is 75% with respect to the partial pressure, and the average ratio is 88% with respect to the case where both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Comparative Example 6)
A transparent conductive substrate was produced in the same manner as in Example 1 except that the atmosphere for heat treatment of the obtained amorphous transparent conductive film laminate was changed to nitrogen. In this case, the oxygen volume ratio in the heat treatment atmosphere is 0%.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

(Comparative Example 7)
A transparent conductive substrate was produced in exactly the same manner as in Example 1, except that the oxygen partial pressure of the second amorphous transparent conductive film was changed to 3.0 × 10 ⁻³ Pa. The oxygen partial pressure of the second amorphous transparent conductive film is 43% of the optimum oxygen partial pressure, and both the first and second amorphous transparent conductive films have the optimum oxygen partial pressure. The average ratio is 37%.
The film thickness, surface resistance value and specific resistance value, and presence / absence of crystallization of the transparent conductive substrate thus obtained were examined, and the results are shown in Tables 1 and 2.

3. Evaluation As can be seen from the results shown in Table 2, in Examples 1 to 25, crystallization was confirmed after heat treatment of the two-layer amorphous transparent conductive film laminate, but Comparative Examples 1 to 4 and 6 In 7 and 7, no crystallization was confirmed. Under either condition, the heat treatment time is 30 minutes or 60 minutes, but since it was not crystallized in Comparative Examples 1-4, 6 and 7, short-range diffusion of each ion shifted from the lattice position of the indium oxide phase Indicates that this did not happen. Therefore, it was determined that the monolayering that required relatively long-distance diffusion did not occur in Comparative Examples 1-4, 6, and 7. Further, in Comparative Example 5, crystallization of only one layer of the first amorphous transparent conductive film having a low tin oxide content in the two-layer amorphous transparent conductive film laminate was confirmed. .

In Table 1, in Examples 1 to 12 and Comparative Examples 1 to 4, at least one of the two amorphous transparent conductive films constituting the transparent conductive film laminate includes tetravalent tin oxide. Sputtered film formation under the conditions of indium oxide to be used, tin oxide content of the two-layer amorphous transparent conductive film being in the range of 0 to 10% by weight, and DC power density of 1.1 W / cm ² It is common to implement. The difference between Examples 1 to 12 and Comparative Examples 1 to 4 is that the oxygen partial pressure in the case of forming a two-layer amorphous transparent conductive film by sputtering is different.
In Examples 1 to 12, the oxygen partial pressure of the first amorphous transparent conductive film with respect to the optimum oxygen partial pressure of the first amorphous transparent conductive film and the second amorphous transparent conductive film The average ratio of the oxygen partial pressure of the second amorphous transparent conductive film to the oxygen partial pressure is in the range of 30 to 91%. For this reason, in Examples 1-12, it crystallized also by the heat processing in the atmosphere for 60 minutes and 150 degreeC, and the low surface resistance value suitable for an electrostatic capacitance type touch panel use etc. is obtained.

On the other hand, in the comparative example 1, the said average ratio was not in the range of 30 to 91%, but was a low condition of 9%. For this reason, it is not crystallized even by atmospheric heat treatment at 150 ° C. for 60 minutes, and the surface resistance value is high.
On the other hand, in Comparative Examples 2 to 4, unlike Examples 1 to 12, the average ratio is a high condition of 100% or more, which exceeds the above range. For this reason, it is not crystallized even by atmospheric heat treatment at 150 ° C. for 60 minutes, and the surface resistance value is high.

In Examples 13 and 14, the content of one tetravalent tin oxide of the two amorphous transparent conductive films constituting the transparent conductive film laminate is 21 wt% or 25 wt%. Sputtered film was formed under the condition of DC power density of 3.4 W / cm ² and crystallized sufficiently after atmospheric heat treatment at 150 ° C. for 60 minutes, resulting in a low surface resistance value suitable for capacitive touch panel applications. It has been.
On the other hand, in Comparative Example 5, the content of one tetravalent tin oxide of the two amorphous transparent conductive films constituting the transparent conductive film laminate is 40% by weight, and 25% by weight. Over. For this reason, it is not crystallized even by atmospheric heat treatment at 150 ° C. for 60 minutes, and the surface resistance value is high.

In Examples 15 to 20, the tin oxide content of the two amorphous transparent conductive films constituting the transparent conductive film laminate was 3.3 to 10% by weight, and the DC power density was 3.4 W / cm. Sputtering film formation is performed under the conditions of ² . In particular, in Examples 18 and 19, in the sputtering film formation, the ratio of the oxygen partial pressure of the first amorphous transparent conductive film to the optimum oxygen partial pressure of the first amorphous transparent conductive film is 60 to 122. By setting the ratio of the oxygen partial pressure of each layer of the second amorphous transparent conductive film to 60% within the range of 30% within the range of 22% to 65%, It has been crystallized sufficiently by atmospheric heat treatment, and a surface resistance value of 110 Ω / □ or less is obtained, and a low surface resistance value optimal for a capacitive touch panel application has been obtained.

  In Examples 21 to 24, one of the two amorphous transparent conductive films constituting the transparent conductive film laminate was not tetravalent tin oxide, but tetravalent titanium oxide, trivalent gallium oxide, Hexavalent tungsten oxide or divalent zinc oxide is used. Sputtered film formation was performed under the same conditions as in Examples 1 to 12, followed by sufficient heat crystallization at 150 ° C. for 60 minutes to obtain a low surface resistance value suitable for capacitive touch panel applications. ing.

In Example 25, after sputtering film formation under the same conditions as in Example 8, heat treatment was performed at 150 ° C. in an oxygen atmosphere. As a result, it has been sufficiently crystallized in an atmospheric heat treatment time of 30 minutes, and a low surface resistance value suitable for capacitive touch panel applications and the like has been obtained.
In contrast, in Comparative Example 6, as in Example 25, after sputtering film formation under the same conditions as in Example 8, heat treatment was performed at 150 ° C. in a nitrogen atmosphere. Since the volume ratio of oxygen contained in the heat treatment atmosphere is 0%, it is not crystallized and has a high surface resistance.
In Comparative Example 7, when the oxygen partial pressure of the second amorphous transparent conductive film is higher than the oxygen partial pressure of the first amorphous transparent conductive film, it is not crystallized and the surface resistance The value is high.

About Examples 1-25, the cross-sectional structure | tissue of the transparent conductive film after heat processing was observed by TEM. As a result, in all of Examples 1 to 25, the interface of the laminate did not exist and was formed into a single layer.
In the cross-sectional TEM image of the transparent conductive film after the heat treatment of Example 2 shown in FIG. 11, it is confirmed that the lattice stripes have reached the interface with the undercoat layer from the transparent conductive film surface, so that the single layer is formed. Is done. Further, as a result of examining the composition distribution in the film thickness direction of the cross section of the transparent conductive film after the heat treatment of Example 2 by EDS analysis shown in FIG. Since the composition in the vicinity of the average content is taken, it is considered that the composition is close to monolayering.
In the cross-sectional TEM image of the transparent conductive film after heat treatment of Example 19 shown in FIG. 17, as in Example 2, the lattice stripes reach the interface with the undercoat layer from the surface of the transparent conductive film. A state of stratification is confirmed. Further, as a result of examining the composition distribution in the film thickness direction of the cross section of the transparent conductive film after the heat treatment of Example 2 by EDS analysis shown in FIG. It was confirmed that there was a concentration gradient.

On the other hand, about Comparative Examples 1-7, although the same TEM observation was implemented, it was not crystallizing or it remained with two layers.
In the cross-sectional TEM image of the transparent conductive film after the heat treatment of Comparative Example 5 shown in FIG. 14, the thin film made of indium oxide containing 2% by weight of tin oxide formed as the first amorphous transparent conductive film is crystallized. However, it is observed that the thin film made of indium oxide containing 40% by weight of tin oxide formed as the second amorphous transparent conductive film is not crystallized and is amorphous. And the interface of two layers exists clearly.
From the above, the transparent conductive base material of the present invention has a single layer and a crystalline structure formed by the heat treatment under the predetermined conditions by the production method of the present invention. It is clear that a transparent conductive film is formed.

  The transparent conductive base material of the present invention can be used for a capacitive touch panel for smartphones and tablet PCs since a high-quality transparent conductive film having crystallinity and low resistance is formed on the base material.

DESCRIPTION OF SYMBOLS 1 Amorphous transparent electrically conductive film laminated body 3, 6, 8 which consists of 2 layers of transparent base materials 2, 5, 7 Single layer and crystalline transparent conductive film 4 Transparent film base material 9 Undercoat layer 10 Adhesive Layers 11-14 Transparent conductive films 21, 51, 71 First amorphous transparent conductive film 22, 52, 72 Second amorphous transparent conductive film

Claims (13)

Transparent conductive in which a single-layer and crystalline transparent conductive film made of indium oxide or indium oxide containing at least one oxide of 2 to 6 metal elements is formed on one side or both sides of a transparent substrate An adhesive substrate,
The transparent conductive film is sequentially formed as two layers of a first amorphous transparent conductive film and a second amorphous transparent conductive film, and then the obtained transparent conductive film laminate is heat-treated. Formed,
The first amorphous transparent conductive film is different from the second amorphous transparent conductive film in that the total weight ratio of the oxides of divalent to hexavalent metal elements represented by the following formula (A) is A transparent conductive substrate, wherein a total weight ratio of oxides of 2 to 6 metal elements in a crystalline transparent conductive film is 16% by weight or less.
{Total weight of oxide of 2 to 6 metal elements / (weight of indium oxide + total weight of oxide of 2 to 6 metal elements)} × 100 (%) Formula (A)   2. The transparent conductive substrate according to claim 1, wherein the oxide of the 2 to 6 valent metal element is any one of zinc oxide, gallium oxide, tin oxide, titanium oxide, and tungsten oxide. The first amorphous transparent conductive film contains indium oxide represented by the following formula (B) or an oxide containing at least one tetravalent metal element oxide in a total weight ratio of 10% by weight or less. Made of indium,
In addition, the second amorphous transparent conductive film contains an oxide of a tetravalent metal element in a total weight ratio that is greater than the total weight ratio of the first transparent conductive film and is 25% by weight or less. Consists of
Furthermore, the single-layered and transparent transparent conductive film contains 5 to 16% by weight of an oxide of at least one tetravalent metal element in a total weight ratio. Transparent conductive substrate.
{Total weight of oxide of tetravalent metal element / (weight of indium oxide + total weight of oxide of tetravalent metal element)} × 100 (%) Formula (B) The first amorphous transparent conductive film contains indium oxide represented by the following formula (B) or an oxide containing at least one tetravalent metal element oxide in a total weight ratio of 25% by weight or less. Made of indium,
In addition, the second amorphous transparent conductive film contains an oxide of a tetravalent metal element in a total weight ratio that is less than the total weight ratio of the first transparent conductive film and is 10% by weight or less. Consists of
Furthermore, the single-layered and transparent transparent conductive film contains 5 to 16% by weight of an oxide of at least one tetravalent metal element in a total weight ratio. Transparent conductive substrate.
{Total weight of oxide of tetravalent metal element / (weight of indium oxide + total weight of oxide of tetravalent metal element)} × 100 (%) Formula (B)   The transparent conductive substrate according to claim 3 or 4, wherein the oxide of a tetravalent metal element is a group consisting of tin oxide and titanium oxide.   The transparent conductive base material according to claim 1, wherein the total film thickness of the single-layer and crystalline transparent conductive film is 35 nm or less.   The total film thickness of the single-layer and crystalline transparent conductive film is 35 nm or less, and the film thickness of at least one of the first or second amorphous transparent conductive film is 10 nm or more. The transparent conductive base material in any one of Claims 1-5.   The transparent conductive substrate according to claim 1, wherein the transparent substrate is a resin film.   Each of the first and second amorphous transparent conductive films contains 3% by weight or more of tin oxide as an oxide of a tetravalent metal element, and the total film thickness of the single-layer and crystalline transparent conductive film The transparent conductive base material according to claim 3, wherein the surface resistance value is 125 Ω / □ or less. A first step of sequentially forming a transparent conductive film laminate composed of two layers of a first and a second amorphous transparent conductive film on one side or both sides of a transparent substrate by sputtering film formation, and obtained The method for producing a transparent conductive substrate according to any one of claims 1 to 9, comprising a second step of obtaining a single-layer and crystalline transparent conductive film by heat-treating the transparent conductive film laminate,
In the first step, the oxygen partial pressure of the first amorphous transparent conductive film with respect to the optimum oxygen partial pressure of the first amorphous transparent conductive film, and the second amorphous transparent conductive film The average ratio of the oxygen partial pressure of the second amorphous transparent conductive film to the optimum oxygen partial pressure of the first and second amorphous transparent conductive films is 18% or more, and oxygen in the sputtering film formation of the first and second amorphous transparent conductive films At least one of the partial pressures is lower than the optimum oxygen partial pressure, and the oxygen partial pressure in sputtering deposition of the first amorphous transparent conductive film is sputtering deposition of the second amorphous transparent conductive film Equal to or greater than the partial pressure of oxygen in
In the second manufacturing step, the transparent conductive film laminate is formed into a single layer by performing a heat treatment in an oxidizing atmosphere.   In the first step, the oxygen partial pressure in sputtering deposition of the first and second amorphous transparent conductive films is both lower than the optimum oxygen partial pressure, and the first amorphous transparent conductive film The method for producing a transparent conductive substrate according to claim 10, wherein an oxygen partial pressure in the sputtering film formation is higher than an oxygen partial pressure in forming the second amorphous transparent conductive film.   In the first step, the oxygen partial pressure of the first amorphous transparent conductive film with respect to the optimum oxygen partial pressure of the first amorphous transparent conductive film, and the second amorphous transparent conductive film 11. The transparent film according to claim 10, wherein the sputtering is performed so that an average ratio of an oxygen partial pressure of the second amorphous transparent conductive film to an optimal oxygen partial pressure of 18 to 91% is 18 to 91%. A method for producing a conductive substrate.   In the said 2nd process, the volume ratio of the oxygen in heat processing atmosphere shall be 20-100%, The manufacturing method of the transparent conductive base material of Claim 10 characterized by the above-mentioned.

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