Transparent conductive thin film

Abstract

The objective is to provide a transparent conductive film that exhibits excellent pen sliding durability, pen pressure resistance, and high precision when used in touch panels. The solution is a transparent conductive film comprising an indium-tin composite oxide transparent conductive film deposited on one side of a transparent plastic film substrate. The indium-tin composite oxide transparent conductive film has a crystal grain size of 10–100 nm, a crystallinity of 20–80%, contains 0.5–10% by mass of tin oxide, and a thickness of 10–30 nm. When the three-dimensional surface roughness SRa of the indium-tin composite oxide transparent conductive film is taken as X, X is 1–100 nm. Furthermore, when the three-dimensional surface roughness SRa of the transparent plastic film substrate on the opposite side to the transparent conductive film is taken as Y, (X³+Y³)¹ / ³ is less than 140 nm.

Description

Technical Field

[0001] This invention relates to a transparent conductive film having a transparent conductive film having a crystalline indium-tin composite oxide layer deposited on a transparent plastic film substrate, and particularly to a transparent conductive film with excellent pen sliding durability, pen pressure resistance, and high precision when used in resistive touch panels. Prior Technology

[0002] Transparent conductive films, which have a transparent and low-resistance thin film deposited on a transparent plastic substrate, are widely used in applications that utilize their conductivity, such as flat panel displays like liquid crystal displays or electroluminescent (EL) displays, or as transparent electrodes for touch panels, and are used in the electrical and electronic fields.

[0003] Resistive film touch panels consist of a fixed electrode with a transparent conductive film coated on a glass or plastic substrate and a movable electrode (film electrode) with a transparent conductive film coated on a plastic film, which are then stacked on top of a display. Pressing the film electrode with a finger or stylus causes the transparent conductive films of the fixed electrode and the film electrode to come into contact, thus providing input for position recognition of the touch panel. Compared to a finger, a stylus usually applies more force to the touch panel. If the stylus is used continuously to input into the touch panel, the transparent conductive film on the film electrode side will be damaged by cracking, peeling, or abrasion. Furthermore, if the touch panel is struck violently with a stylus, or if very strong force is applied to the touch panel, exceeding the force expected for normal use, the transparent conductive film will be damaged by cracking or peeling. To solve these problems, a transparent conductive film that balances excellent pen sliding durability and excellent pen pressure durability is desired. Furthermore, the image on the touch panel also requires high resolution.

[0004] As a means to improve pen sliding durability, there is a method to make the transparent conductive film on the thin film electrode side crystalline (for example, see Patent Document 1). However, conventional transparent conductive films achieve excellent pen sliding durability by controlling the crystallinity of indium-tin composite oxides. However, conventional transparent conductive films are insufficient when performing the pen pressure durability test described later. [Previous Technical Documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2004-071171 Summary of the Invention

[0006] [The problem the invention aims to solve] The purpose of this invention is to provide a transparent conductive film that, in view of the aforementioned problems, exhibits excellent pen sliding durability and pen pressure durability when used in touch panels, and further provides a high-resolution image. [Methods used to solve problems]

[0007] The present invention was made in view of the above-described situation, and the transparent conductive film of the present invention, which can solve the above-described problems, comprises the following structure. 1. A transparent conductive film, comprising a transparent conductive film having an indium-tin composite oxide transparent conductive film deposited on one side of a transparent plastic film substrate, wherein the ON resistance of the transparent conductive film is 10kΩ or less in the following pen sliding durability test, the increase rate of the surface resistance value of the transparent conductive film is 1.5 or less in the following pen pressure test, and furthermore, the total image clarity transmitted by the transparent conductive film with comb widths of 0.125mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm is 250% or more and less than 500%; (Pen sliding durability test method) Using the transparent conductive film of the present invention as one panel, and a transparent conductive film containing an indium-tin composite oxide film (tin oxide content: 10% by mass) with a thickness of 20 nm formed on a glass substrate by sputtering, as another panel; the two panels are arranged with the transparent conductive films facing each other, separated by epoxy resin beads with a diameter of 30 μm, and the film-side panel and the glass-side panel are attached with double-sided tape with a thickness of 170 μm to create a touch panel; then, a load of 2.5 N is applied to a pen made of polyacetal (tip shape: 0.8 mmR), and a linear sliding test of 180,000 reciprocations is performed on the touch panel; in this test, the load of the pen is applied to the transparent conductive film surface of the present invention; The sliding distance was set to 30mm and the sliding speed to 180mm / second. After this sliding durability test, the ON resistance (resistance value when the movable electrode (thin film electrode) is in contact with the fixed electrode) was measured when the sliding part was pressed with a pen load of 0.8N. (Pen weight pressure test method) A transparent conductive film of the present invention, cut into 50mm × 50mm pieces, is used as one panel. A transparent conductive film containing an indium-tin composite oxide film (tin oxide content: 10% by mass) with a thickness of 20nm formed by sputtering on a glass substrate is used as another panel. The two panels are arranged with the transparent conductive films facing each other and separated by epoxy resin beads with a diameter of 30μm. The film-side panel and the glass-side panel are attached with double-sided tape with a thickness adjusted to 120μm to create a touch panel. A pen made of polyacetal (with a tip shape of 0.8mmR) is used to apply a load of 35N at a position 2.0mm from the edge of the double-sided tape and slides it in a straight line 10 times (5 round trips) parallel to the double-sided tape. In this test, the load of the pen is applied to the transparent conductive film surface of the present invention. The sliding distance is set to 30mm and the sliding speed is set to 20mm / second. Sliding is performed at the position without epoxy resin beads. After sliding, the transparent conductive film is removed, and the surface resistance at any 5 points of the sliding part is measured (4-terminal method), and the average value is calculated. When measuring the surface resistance, the 4 terminals are arranged in a direction perpendicular to the sliding part, so that the sliding part is positioned between the 2nd and 3rd terminals. The average surface resistance value of the sliding part is divided by the surface resistance value of the non-sliding part (measured by 4-terminal method), and the increase rate of the surface resistance value is calculated. 2. The transparent conductive film as described in section 1 above, wherein the crystal grain size of the transparent conductive film of indium-tin composite oxide is 10~100nm, the crystallinity of the transparent conductive film of indium-tin composite oxide is 20~80%, the transparent conductive film of indium-tin composite oxide contains 0.5~10% by mass of tin oxide, the thickness of the transparent conductive film of indium-tin composite oxide is 10~30nm, and when the three-dimensional surface roughness SRa of the transparent conductive film of indium-tin composite oxide is taken as X, X is 1~100nm. Furthermore, when the three-dimensional surface roughness SRa of the transparent plastic film substrate opposite to the transparent conductive film side is taken as Y, (X3+Y3)1 / 3 is less than 140nm. 3. The transparent conductive film described in 1 or 2 above, wherein even if an adhesion test (JIS K5600-5-6:1999) is performed on the surface of the transparent conductive film, the transparent conductive film does not peel off, and when a bending resistance test (JIS K5600-5-1:1999) is performed on the transparent conductive film side of the indium-tin composite oxide of the transparent conductive film, the diameter of the mandrel that cracks or peels off is less than 20 mm when the bending part is observed with a 10x magnifying glass. 4. The transparent conductive film as described in any one of items 1 to 3 above, wherein the thickness of the transparent conductive film is 100~250μm. 5. The transparent conductive film as described in any one of items 1 to 4 above, wherein a curable resin layer is present between the transparent conductive film of indium-tin composite oxide and the transparent plastic film substrate. [Effects of the Invention]

[0008] According to the present invention, a transparent conductive film is provided that combines excellent pen sliding durability and excellent pen pressure resistance, thereby providing a high-resolution image. The resulting transparent conductive film is highly suitable for use in resistive touch panels and the like. Simple Explanation of the Diagram

[0009] Figure 1 is a schematic diagram showing an example (1) of the longest part of the crystal grain in the present invention. Figure 2 is a schematic diagram showing another example (2) of the longest part of the crystal grain in the present invention. Figure 3 is a schematic diagram showing another example (3) of the longest part of the crystal grain in the present invention. Figure 4 is a schematic diagram showing another example (4) of the longest part of the crystal grain in the present invention. Figure 5 is a schematic diagram illustrating the position of the central roller in an example of a sputtering apparatus suitable for use in this invention. Implementation

[0010] [The form in which the invention is carried out] The transparent conductive film of the present invention is a transparent conductive film in which an indium-tin composite oxide transparent conductive film is deposited on one side of a transparent plastic film substrate. Preferably, the transparent conductive film has an ON resistance of less than 10kΩ in the following pen sliding durability test, and the surface resistance of the transparent conductive film has an increase rate of less than 1.5 in the following pen pressure test, and the total image clarity of the transparent conductive film with comb widths of 0.125mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm is more than 250% and less than 500%. (Pen sliding durability test) Using the transparent conductive film of the present invention as one panel, and a transparent conductive film containing an indium-tin composite oxide film (tin oxide content: 10% by mass) with a thickness of 20 nm formed by sputtering on a glass substrate as another panel; the two panels are arranged with the transparent conductive films facing each other and separated by epoxy resin beads with a diameter of 30 μm, and the film-side panel and the glass-side panel are attached with double-sided tape with a thickness of 170 μm to create a touch panel; then, a 2.5 N load is applied to a pen made of polyacetal (tip shape: 0.8 mmR), and a linear sliding test of 180,000 reciprocations is performed on the touch panel; in this test, the load of the pen is applied to the transparent conductive film surface of the present invention; the sliding distance is set to 30 mm, and the sliding speed is set to 180 mm / s; after this sliding durability test, the ON resistance (resistance value when the movable electrode (film electrode) is in contact with the fixed electrode) is measured when the pen load of 0.8 N is pressed on the sliding part. (Pen weight pressure test) One panel uses a transparent conductive film of the present invention cut into 50mm × 50mm pieces, and the other panel uses a transparent conductive film containing an indium-tin composite oxide film (tin oxide content: 10% by mass) with a thickness of 20nm formed by sputtering on a glass substrate. The two panels are arranged with the transparent conductive films facing each other, separated by epoxy resin beads with a diameter of 30μm. A double-sided adhesive tape with a thickness adjusted to 120μm is used to attach the film-side panel and the glass-side panel to create a touch panel. A 35N load is applied using a polyacetal pen (with a tip shape of 0.8mmR) at a position 2.0mm from the edge of the double-sided adhesive tape, parallel to the tape. Ten linear sliding operations (five round trips) were performed. In this test, a pen load was applied to the transparent conductive film surface of the present invention. The sliding distance was set to 30 mm and the sliding speed was set to 20 mm / s. However, the sliding was performed at a position without epoxy resin beads. After sliding, the transparent conductive film was removed, and the surface resistance at any five points of the sliding part was measured (4-terminal method), and the average value was calculated. When measuring the surface resistance, four terminals were arranged in a direction perpendicular to the sliding part, so that the sliding part came to the position between the second and third terminals. The average surface resistance value of the sliding part was divided by the surface resistance value of the non-sliding part (measured by the 4-terminal method), and the increase rate of the surface resistance value was calculated.

[0011] The transparent conductive film of this invention exhibits excellent pen sliding durability and pen pressure resistance. Pen sliding durability and pen pressure resistance are opposite properties. First, let's explain pen sliding durability. The transparent conductive film of indium-tin composite oxide with excellent pen sliding durability has high crystallinity and large crystal grain size. We will explain crystallinity and crystal grain size. The portion with a circular or polygonal shape observed under a transmission electron microscope is defined as the crystallization (=crystal grain) of the transparent conductive film, and the portion outside of this is defined as amorphous. High crystallinity means a high proportion of crystals. Large crystal grain size means a large circular or polygonal area observed under a transmission electron microscope. The transparent conductive film with high crystallinity has a high proportion of hard crystals, and the strain around the crystal grains is greater due to the larger crystal grain size, thus the transparent conductive film becomes harder, resulting in excellent pen sliding durability. Next, let's explain pen pressure resistance. Transparent conductive films of indium-tin composite oxides with excellent pen-weight pressure resistance must have low crystallinity, small crystal grain size, and low three-dimensional surface roughness. Three-dimensional surface roughness will be explained later, but firstly, transparent conductive films with low crystallinity have a higher proportion of soft amorphous material and smaller crystal grain size, resulting in less strain around the crystal grains. Therefore, even when subjected to load, the transparent conductive film is less prone to cracking, leading to excellent pen-weight pressure resistance. As mentioned earlier, pen sliding durability and pen-weight pressure resistance are opposite properties. Through review, it was discovered that by controlling the crystallinity and crystal grain size of the transparent conductive film, both pen sliding durability and pen-weight pressure resistance can be achieved. A transparent conductive film that achieves both pen sliding durability and pen-weight pressure resistance will be explained.

[0012] If the ON resistance of the transparent conductive film in the pen sliding durability test of this invention is 10kΩ or less, then even with continuous pen input to the touch panel, it is more suitable for suppressing cracks, peeling, and wear of the transparent conductive film. In one sample, the ON resistance can be 9.5kΩ or less, preferably 5kΩ or less. For example, the ON resistance can be 3kΩ or less, 1.5kΩ or less, preferably 1kΩ or less. If the ON resistance is 0kΩ, the pen sliding durability is excellent; as long as it is this invention, the ON resistance can also be 0kΩ. The ON resistance can be, for example, 3kΩ or more, or 5kΩ or more. Because the ON resistance is within such a range, even with continuous pen input to the touch panel, cracks, peeling, and wear are suppressed in the transparent conductive film. In a single sample, the upper and lower limits can be appropriately combined.

[0013] In this invention, the increase rate of surface resistivity of the transparent conductive film in the pen weight pressure test should preferably be 1.5 or less. Due to this characteristic, even when subjected to forces exceeding those typically expected, cracking and peeling of the transparent conductive film can be suppressed. More preferably, the increase rate of surface resistivity is 1.2 or less, and most preferably 1.0 (no increase). Here, the increase rate of the surface resistivity of the transparent conductive film of the present invention is preferably 1.0 or higher.

[0014] In a single sample, the ON resistance of the transparent conductive film in the pen sliding durability test is 0.05kΩ to 9.5kΩ, and the increase rate of the surface resistance of the transparent conductive film in the pen pressure (durability) test is 1.0 to 1.5. As mentioned above, pen sliding durability and pen pressure durability are typically opposite properties. In this invention, both durability properties are well balanced within a certain range. Furthermore, even with continuous pen input to the touch panel, cracking, peeling, and abrasion are suppressed in the transparent conductive film, and excellent durability is exhibited against the loads caused by pen sliding and pen pressure. Moreover, the numerical range can be selected from the ranges and values ​​described in this specification.

[0015] In this invention, a high-resolution image is ideally provided when the total image clarity of the transparent conductive film with comb widths of 0.125mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm is 250% or more and less than 500%. A higher total image clarity indicates higher image sharpness, i.e., superior high resolution. Preferably, the total image clarity of the transparent conductive film is 300% or more. Even more preferably, the total image clarity of the transparent conductive film is 400% or more. Furthermore, the term "comb width" in this instruction manual refers to the optical comb width according to JIS-K7105.

[0016] The transparent conductive film of this invention is an indium-tin composite oxide transparent conductive film with a preferably crystal grain size of 10-100 nm and a preferably crystallinity of 20-80%. If the crystal grain size of the indium-tin composite oxide transparent conductive film is 10 nm or more, the transparent conductive film becomes moderately hardened due to the strain around the crystal grains, resulting in excellent pen sliding durability, and is therefore preferred. More preferably, the crystal grain size of the indium-tin composite oxide transparent conductive film is 30 nm or more. On the other hand, if the crystal grain size of the transparent conductive film of indium-tin composite oxide is less than 100 nm, the transparent conductive film will not become too stiff due to the strain around the crystal grains, thus exhibiting excellent durability under heavy pressure, making it more suitable. The crystal grain size of the transparent conductive film of indium-tin composite oxide is preferably less than 90 nm. In a single sample, the crystal grain size of the transparent conductive film of indium-tin composite oxide is 30 nm to 95 nm, for example, 40 nm to 90 nm. If the crystallinity of the transparent conductive film of indium-tin composite oxide is 20% or higher, it becomes moderately hard due to the presence of hard crystals, resulting in excellent pen sliding durability, making it a more desirable material. Ideally, the crystallinity of the transparent conductive film of indium-tin composite oxide should be 25% or higher. On the other hand, if the crystallinity of the transparent conductive film of indium-tin composite oxide is 80% or lower, the amount of hard crystals present is high, but the transparent conductive film is not excessively hard, thus resulting in excellent pen durability under heavy pressure, making it a more desirable material. In a single sample, the crystallinity of the transparent conductive film of indium-tin composite oxide is 25% to 78%, for example, 25% to 76%.

[0017] In this invention, the transparent conductive film uses the three-dimensional surface roughness SRa of the transparent conductive film as X, where X is preferably 1~100 nm. If X is 1~100 nm, the surface protrusions of the transparent conductive film are small, thus reducing the deformation of the surface protrusions during pen weight pressure tests, thereby suppressing cracking of the transparent conductive film. Furthermore, the presence of some surface protrusions in the transparent conductive film also helps maintain the film's rollability, making it more suitable. X is more preferably 1~80 nm. X is particularly preferably 1~65 nm.

[0018] The transparent conductive film in the present invention is constructed of indium-tin complex oxide, preferably one comprising more than 0.5 mass % or less than 10 mass % of antimony oxide. Tin oxide in the indium-tin complex oxide is equivalent to being an impurity for indium oxide. The melting point of the indium-tin complex oxide increases by resorting to impurities containing manganese oxide. That is, the impurities containing antimony oxide will act in a direction that hinders crystallization, making it an important factor with strong correlation with crystallinity such as crystal particle size or degree of crystallinity. If more than 0.5% by mass of tin oxide is contained, the surface resistance of a transparent conductive thin film will become a practical standard and be more desirable. The content of tin oxide is more preferably 1 mass % or more, and the extra optimal is 2 mass % or more. If the content of manganese oxide is less than 10% by mass, crystallization after conditioning into the semicrystalline state described later becomes easy to occur, and pen sliding durability becomes good, and is preferable. The content of manganese oxide is more preferably less than 8 mass %, especially less than 6 mass %, and extra preferably less than 4 mass %. Furthermore, the surface resistance of the transparent conductive thin film of the present invention is preferably 50~900Ω / □ and more preferably 50~600Ω / □.

[0019] The thickness of the transparent conductive film in the present invention is preferably 10 nm or more and 30 nm or less. The thickness of the transparent conductive film, which is an important factor in strong correlation with crystallinity such as crystal grain size or degree of crystallinity. If the thickness of the transparent conductive film is more than 10nm, the amorphous will not be too much in the transparent conductive film, easily giving a moderate crystal grain size and degree of crystallization that become the semicrystalline state described later, and as a result, it is more advisable to maintain the durability of pen sliding. The thickness of the transparent conductive film is preferably 13nm or more, especially 16nm or more. Also, if the thickness of the transparent conductive film is less than 30nm, the crystal particle size of the transparent conductive film will not be too large, the degree of crystallization will not be too high, it is easy to maintain a semicrystalline state, which can maintain the durability of pen weight pressurization and is more appropriate. Preferably below 28nm, especially below 25nm.

[0020] In this invention, the transparent conductive film uses the three-dimensional surface roughness SRa on the opposite side of the transparent conductive film on the transparent plastic film substrate as Y. If (X3+Y3)1 / 3 is less than 140nm, then the sum of the transmitted image clarity of the transparent conductive film with comb widths of 0.125mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm is more than 250% and less than 500%, thus providing a more ideal high-resolution image. The smaller the value of ((X3+Y3)1 / 3), the smaller the unevenness on both sides of the transparent conductive film. Therefore, it is confirmed and utilized that the incident light of the transparent conductive film tends to be more direct, resulting in higher image clarity. (X3+Y3)1 / 3 is preferably below 120nm, and even more preferably below 70nm. If (X3+Y3)1 / 3 is above 1nm, there will be some surface protrusions in the transparent conductive film, which can maintain the film's rollability and is therefore more suitable.

[0021] The transparent conductive film in this invention is preferably one that does not peel off even when an adhesion test (JIS K5600-5-6:1999) is performed on the surface of the transparent conductive film. A transparent conductive film that does not peel off during the adhesion test is preferable because the transparent conductive film is tightly bonded to a transparent plastic substrate or a hardened resin layer, etc., in contact with the transparent conductive film. Therefore, even with continuous pen input to the touch panel, cracks, peeling, and abrasion can be suppressed in the transparent conductive film. Furthermore, even when subjected to forces exceeding those typically expected for use, cracks and peeling can be suppressed in the transparent conductive film, making it more suitable.

[0022] The transparent conductive film of this invention is preferably subjected to a bending resistance test (JIS K5600-5-1:1999) on the transparent conductive film side. When observing the bent portion with a 10x magnifying glass, the diameter of the mandrel that cracks or peels off is less than 20 mm. If the mandrel diameter is less than 20 mm, the layer in contact with the transparent conductive film will not crack during the pen weight pressure test, and there will be no cracks in the transparent conductive film, which is therefore preferable. More preferably, it is less than 18 mm. In a single-state sample, the bending resistance test value can be 1 mm or more, for example, 8 mm or more, or 10 mm or more. Also, in a single-state sample, the bending resistance test value can be 13 mm or more, or 15 mm or more. Within this range, the layer in contact with the transparent conductive film will not break during the pen pressure test, and there will be no cracks in the transparent conductive film, which is therefore more suitable. Furthermore, a transparent conductive film that combines excellent pen sliding durability with excellent pen pressure durability can be provided.

[0023] The thickness of the transparent conductive film substrate in this invention is preferably in the range of 100-250 μm, more preferably 130-220 μm. If the thickness of the plastic film is 100 μm or more, mechanical strength can be maintained, resulting in less deformation during pen input, especially for use in touch panels, and excellent pen sliding durability and pen pressure resistance. On the other hand, if the thickness is 250 μm or less, it is less necessary to increase the load required to position the film at the pen input location when using it in a touch panel.

[0024] The transparent conductive film of this invention preferably has a hardened resin layer between the transparent conductive film and the plastic film substrate. Because of the hardened resin layer, the adhesion of the transparent conductive film is increased or the force applied to the transparent conductive film is dispersed. Therefore, in pen sliding tests, cracks, peeling, and wear of the transparent conductive film can be suppressed. Furthermore, in pen pressure tests, cracks and peeling of the transparent conductive film can be suppressed, making it more suitable.

[0025] The transparent conductive film of this invention has a crystallinity that is neither too high nor too low (such crystallinity is defined as semi-crystalline or semi-crystalline). It is very difficult to stably make a transparent conductive film semi-crystalline. This is because the semi-crystalline state is the state where the rapid phase change from amorphous to crystalline stops. Therefore, sensitive to parameters related to crystallinity, namely the amount of water in the film-forming environment, and especially very sensitive to hydrogen-containing gases, even a slight decrease in the amount of hydrogen-containing gas or water in the film-forming environment will result in almost complete crystallinity (high crystallinity); conversely, even a slight increase in the amount of hydrogen-containing gas or water in the film-forming environment will result in amorphousness (low crystallinity).

[0026] There are no particular limitations on the manufacturing method for obtaining the transparent conductive film of the present invention, but the following manufacturing method can be preferred as an example. Sputtering is a preferred method for forming a transparent conductive film of crystalline indium-tin composite oxide on at least one side of a transparent plastic film substrate. For high-productivity manufacturing of transparent conductive films, a roller sputtering apparatus is preferred, which supplies a film roll and, after film formation, winds it into a roll shape. Alternatively, a method can be employed where a hydrogen-containing gas (hydrogen, ammonia, a hydrogen + argon mixture, etc., any gas containing hydrogen atoms is not particularly limited, except for water) is introduced into the film-forming environment using a mass flow controller. The film temperature during sputtering is then set below 0°C. A sintering target containing 0.5–10% by mass of indium-tin composite oxide is used, and the thickness of the transparent conductive film of the indium-tin composite oxide is adjusted to be 10–30 nm. The transparent conductive film is formed on a transparent plastic film with a three-dimensional surface roughness SRa of 1–100 nm. In the film-forming environment during sputtering, a gas system containing hydrogen atoms has the effect of hindering the crystallization of the transparent conductive film. When hydrogen gas flows in the film-forming environment, the ideal value (hydrogen flow rate) ÷ (inert gas flow rate + hydrogen flow rate) × 100 (sometimes only recorded as hydrogen concentration) is 0.01% to 3.00%. For example, the hydrogen concentration can be 0.01% to 2.00%, or 0.01% to 1.00%. Because the hydrogen concentration is within such a range, it can help lead to good results in either the pen sliding durability test ON resistance value or the pen pressure durability test. Furthermore, examples of inert gases include helium, neon, argon, krypton, and xenon. When using hydrogen-containing gases other than hydrogen, the amount of hydrogen atoms in the hydrogen-containing gas can be converted into the amount of hydrogen molecules for calculation. When the hydrogen-containing gas is precisely flowed using a mass flow controller in the film-forming environment, the gas outlet is configured perpendicular to the length direction of the film roll to uniformly spray the hydrogen-containing gas. This prevents the formation of a transparent conductive film with a mixture of highly crystalline and less crystalline portions, and easily yields a uniformly semi-crystalline transparent conductive film. Therefore, it is suitable to obtain a transparent conductive film that possesses both excellent pen sliding durability and pen pressure resistance. It is known that a high water content in the film-forming environment reduces the crystallinity of the transparent conductive film; therefore, the amount of water in the film-forming environment is also an important factor. When using a gas containing hydrogen atoms, the midpoint (the midpoint between the maximum and minimum values) of the ratio of water pressure to inert gas in the film-forming environment during sputtering of the film roll is controlled between 1.0 × 10⁻⁴ and 2.0 × 10⁻³. Furthermore, if the difference between the maximum and minimum values ​​of the ratio of water pressure to inert gas in the film-forming environment during sputtering is less than 1.0 × 10⁻³ from the start to the end of film formation, the uniformity of crystallinity of the transparent conductive film can be maintained along the entire length of the film. Therefore, in addition to rotary pumps, turbomolecular pumps, and cryogenic pumps, which are more suitable as exhaust devices for sputtering machines, the following bombardment steps and the limitation of the height difference of the unevenness of the end face of the film roll can also be addressed by setting the method to reduce the amount of water released from the film during the formation of the transparent conductive film and to release water in a way that is uniform along the entire length of the film. This would make it more suitable to reduce the amount of water released from the film and to release water in a way that is uniform along the entire length of the film. However, the central value of the moisture pressure relative to the inert gas ratio also depends somewhat on the tin oxide content or the thickness of the transparent conductive film in the indium-tin composite oxide transparent conductive film. When the amount of tin oxide added in the indium-tin composite oxide transparent conductive film is high or the transparent conductive film is thin, it is advisable to set the central value of the moisture pressure relative to the inert gas ratio at the lower end of the aforementioned range. Conversely, when the tin oxide content in the indium-tin composite oxide transparent conductive film is low or the transparent conductive film is thick, it is advisable to set the central value of the moisture pressure relative to the inert gas ratio at the higher end of the aforementioned range. Preferably, the film temperature during sputtering is set to below 0°C to form a transparent conductive film on a transparent plastic film. The film temperature during film formation is replaced by the set temperature of the temperature control machine used to regulate the temperature of the central roller that the traveling film contacts. Here, Figure 5 shows a schematic diagram of an example of a sputtering apparatus suitable for use in the present invention, in which the traveling film 1 travels by partially contacting the surface of the central roller 2. An indium-tin composite oxide film is deposited and laminated on the surface of the film 1 that travels on the central roller 2 by setting an indium-tin sputtering target 4 through a chimney 3. The central roller 2 is temperature-controlled by a temperature controller (not shown).If the film temperature is below 0°C, the release of impurity gases such as water and organic gases from the film, which cause changes in the crystallinity of the transparent conductive film, can be suppressed, making it easier to achieve uniform crystallinity of the transparent conductive film from the start to the end of film formation. When using a hydrogen-containing gas, the midpoint (the middle of the maximum and minimum values) of the ratio of water pressure to inert gas in the film-forming environment during sputtering is preferably 1.0 × 10⁻⁴ to 2.0 × 10⁻³. If the ratio of water pressure to inert gas in the film-forming environment during sputtering is within the aforementioned range, the hydrogen-containing gas effectively hinders the crystallinity of the transparent conductive film. Furthermore, to achieve practical levels of surface resistivity and total light transmittance of the transparent conductive film, oxygen should be added during sputtering. This manufacturing method aims to minimize the influence of water, a factor causing changes in the crystallinity of the transparent conductive film, and primarily focuses on controlling crystallinity using a hydrogen-containing gas.

[0027] In controlling the amount of water during the formation of indium-tin composite oxide films on plastic films, observing the actual amount of water during film formation is superior to observing the ultimate vacuum for the following two reasons.

[0028] Regarding the first reason, if the film is formed by sputtering and is a plastic film, the film is heated and moisture is released from the film. Therefore, the amount of water in the film-forming environment increases, which is more than the amount of water when measuring the ultimate vacuum. Thus, the amount of water during film formation is more accurate than the ultimate vacuum.

[0029] The second reason concerns the apparatus used for feeding large quantities of transparent plastic film. In such an apparatus, the film is fed in the form of a film roll. If the film is fed into the vacuum chamber as a roll, the water in the outer layer of the roll easily escapes, but the water in the inner layer is difficult to escape. When measuring the ultimate vacuum, the film roll stops, but during film formation, the film roll moves, so the inner layer of the film roll, which contains more water, is rolled out, thus increasing the amount of water in the film formation environment, even more than when measuring the ultimate vacuum. In this invention, when controlling the amount of water in the film formation environment, it is better controlled by observing the ratio of water pressure to inert gas in the film formation environment during sputtering.

[0030] Before forming the transparent conductive film, it is advisable to subject the film to a bombardment step. The bombardment step involves applying a voltage to a mixture of an inert gas (such as argon) or a reactive gas (such as oxygen) and an inert gas to generate plasma. Specifically, it is preferable to bombard the film using an SUS target or similar method via RF sputtering. Because the film is exposed to the plasma during the bombardment step, water or organic components are released from the film. This release of water or organic components during the formation of the transparent conductive film reduces the likelihood of achieving uniform crystallinity from the start to the end of film formation. Furthermore, since the layers in contact with the transparent conductive film are activated by the bombardment step, the adhesion of the transparent conductive film is improved, thus enhancing pen sliding durability or pen pressure resistance.

[0031] The film roll used for forming transparent conductive films is tied to the end face of the roll, and the height difference between the most convex and the most concave part is preferably less than 10 mm. If it is less than 10 mm, the unevenness of the release of water or organic components from the end face of the film is reduced when the film roll is put into the sputtering device. Therefore, the crystallinity of the transparent conductive film is more easily homogenized from the beginning to the end of film formation.

[0032] In a method for forming a transparent conductive film of crystalline indium-tin composite oxide on at least one side of a transparent plastic film substrate, oxygen is preferably introduced during sputtering. If oxygen is introduced during sputtering, the adverse conditions caused by oxygen deficiency in the transparent conductive film of the indium-tin composite oxide disappear, the surface resistance of the transparent conductive film is low, and the total light transmittance is high, which is preferable. Therefore, in order to make the surface resistance and total light transmittance of the transparent conductive film reach a practical level, oxygen is preferably introduced during sputtering. Furthermore, the total light transmittance of the transparent conductive film of the present invention is preferably 70-95%.

[0033] The transparent conductive film of this invention is formed by depositing an indium-tin composite oxide transparent conductive film on a transparent plastic film substrate, and then subjecting it to a heat treatment at 80-200°C for 0.1-12 hours in an oxygen-containing environment. If the temperature is above 80°C, it is easier to slightly increase the crystallinity to achieve a semi-crystalline state, thus improving pen sliding durability. If the temperature is below 200°C, it is better to ensure the planarity of the transparent plastic film.

[0034] <Transparent Plastic Film Substrate> The transparent plastic film substrate used in this invention is formed by melt extrusion or solution extrusion of organic polymers into a film shape. Depending on the need, the film is stretched, cooled, and heat-set in the length and / or width directions. Examples of organic polymers include polyethylene, polypropylene, polyethylene terephthalate, polyethylene 2,6-naphthalenedicarboxylate, polyethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyimide, polyamide-imide, polyethersulfone, polyetheretherketone, polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, polyphenylene sulfide, polyphenylene ether, polystyrene, para-polystyrene, and norbornene polymers.

[0035] Among these organic polymers, polyethylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalenedicarboxylate, para-polystyrene, norbornene polymers, polycarbonate, and polyarylates are preferred. Furthermore, these organic polymers can also be copolymerized in small amounts with monomers of other organic polymers, or blended with other organic polymers.

[0036] The transparent plastic film substrate used in this invention can be subjected to surface activation treatments such as corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, and ozone treatment, without impairing the purpose of this invention.

[0037] If a curable resin layer is coated onto a transparent plastic film substrate, the transparent conductive film can strongly bond with the curable resin layer or disperse the force applied to the transparent conductive film. Therefore, it is more effective in suppressing cracks, peeling, and abrasion in pen sliding tests, and also in suppressing cracks and peeling in pen pressure tests. Furthermore, if the surface of the curable resin layer is made uneven before forming the transparent conductive film, the actual contact area between the transparent conductive film and the glass is reduced during the pen sliding test. This improves the sliding properties between the glass surface and the transparent conductive film, enhances pen sliding durability, and may also improve the film roll winding performance or Newton's ring resistance. However, if the unevenness is too large, the deformation of the surface protrusions during the pen pressure test will be greater, potentially causing cracks in the transparent conductive film. Therefore, when the three-dimensional surface roughness SRa of the transparent conductive film is taken as X, X is preferably 1~100 nm. Furthermore, the curable resin layer can also be coated on both sides of the transparent plastic film substrate. When the three-dimensional surface roughness SRa of the curable resin layer on the side opposite to the side forming the transparent conductive film is taken as Y, Y is preferably 1~139 nm. The details of the curable resin layer are described below.

[0038] Furthermore, the aforementioned curing resin, which is more suitable for use in this invention, is not particularly limited as long as it is a resin that is cured by the application of energy such as heating, ultraviolet radiation, or electron beam irradiation. Examples include polysiloxane resin, acrylic resin, methacrylic resin, epoxy resin, melamine resin, polyester resin, and urethane resin. From a production point of view, it is preferable to use an ultraviolet curing resin as the main component.

[0039] Examples of such UV-curable resins include multifunctional acrylate resins such as acrylic or methacrylate resins made from polyols, and multifunctional urethane acrylate resins synthesized from diisocyanates, polyols, and hydroxyalkyl esters of acrylic or methacrylates. If desired, monofunctional monomers, such as vinylpyrrolidone, methyl methacrylate, and styrene, can be added to these multifunctional resins to copolymerize them.

[0040] Furthermore, in order to improve the adhesion between the transparent conductive film and the curing resin layer, it is effective to treat the surface of the curing resin layer using the methods described below. Specific methods include discharge treatment methods such as glow discharge or corona discharge to increase carbonyl, carboxyl, and hydroxyl groups, and chemical treatment methods such as acid or alkali treatment to increase polar groups such as amine, hydroxyl, and carbonyl groups.

[0041] UV-curable resins are typically used with the addition of photopolymerization initiators. Well-known compounds that absorb ultraviolet light and generate free radicals can be used as photopolymerization initiators without particular restriction; examples of such initiators include various benzoin derivatives, phenyl ketones, and diphenyl ketones. The amount of photopolymerization initiator added is typically 1 to 5 parts by weight per 100 parts by weight of the UV-curable resin.

[0042] Furthermore, in the curing resin layer of the present invention, in addition to the curing resin as the main component, inorganic or organic particles are preferably also used. By dispersing the inorganic or organic particles in the curing resin, unevenness can be formed on the surface of the curing resin, thereby improving the surface roughness over a wide area.

[0043] Examples of the aforementioned inorganic particles include silicon dioxide. Examples of the aforementioned organic particles include polyester resins, polyolefin resins, polystyrene resins, and polyamide resins.

[0044] In addition to inorganic or organic particles, it is preferable to use a resin immiscible with the curing resin in addition to the main component curing resin. By using a small amount of the immiscible curing resin in the curing resin, phase separation can occur in the curing resin, dispersing the immiscible resin into particles. These dispersed particles of the immiscible resin can create unevenness on the surface of the curing resin, increasing the surface roughness over a wide area.

[0045] Examples of immiscible resins include polyester resins, polyolefin resins, polystyrene resins, and polyamide resins.

[0046] This section illustrates, as an example, the blending ratio of inorganic particles in the curing resin layer directly beneath the transparent conductive film. For every 100 parts by weight of the UV-curing resin, preferably 0.1 to 20 parts by weight of inorganic particles, more preferably 0.1 to 15 parts by weight, and most preferably 0.1 to 12 parts by weight. If the amount of inorganic particles incorporated is 0.1 to 20 parts by mass per 100 parts by mass of UV-curable resin, the protrusions formed on the surface of the cured resin layer will not be too small, effectively imparting three-dimensional surface roughness. During pen weight pressure test, the deformation of the surface protrusions will be reduced, thus inhibiting the occurrence of cracks in the transparent conductive film and providing a high-precision image. Furthermore, since there will be some surface protrusions in the transparent conductive film, the film rollability is also maintained, which is more suitable.

[0047] This section illustrates, as an example, the blending ratio of inorganic particles used in a curing resin layer on the opposite side from the side forming the transparent conductive film. For every 100 parts by weight of the UV-curing resin, preferably 0.1 to 25 parts by weight of inorganic particles, more preferably 0.1 to 15 parts by weight, and most preferably 0.1 to 12 parts by weight. If the amount of inorganic particles incorporated is 0.1 to 25 parts by mass per 100 parts by mass of UV-curable resin, the protrusions formed on the surface of the cured resin layer will not be too small, which can effectively impart three-dimensional surface roughness and provide a high-precision image. Furthermore, since there will be some surface protrusions in the transparent conductive film, the film rollability can also be maintained, which is more suitable.

[0048] The aforementioned UV-curable resin, photopolymerization initiator, and inorganic or organic particles, or resins immiscible with UV-curable resin, are each dissolved in a common solvent to prepare the coating solution. There are no particular restrictions on the solvent used; for example, alcohol solvents such as ethanol and isopropanol, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as dibutyl ether and ethylene glycol monoethyl ether, ketone solvents such as methyl isobutyl ketone and cyclohexanone, and aromatic hydrocarbon solvents such as toluene, xylene, and solvent oils can be used alone or in combination.

[0049] The concentration of the resin components in the coating solution can be appropriately selected considering factors such as the viscosity required for the coating method. For example, the combined percentage of UV-curable resin, photopolymerization initiator, and high molecular weight polyester resin in the coating solution is typically 20-80% by mass. Furthermore, other well-known additives, such as polysiloxane leveling agents, can be added to the coating solution as needed.

[0050] In this invention, the prepared coating liquid is applied to a transparent plastic film substrate. There are no particular limitations on the coating method; conventional methods such as bar coating, gravure coating, and reverse coating can be used.

[0051] The coating solution is evaporated to remove the solvent in the next drying step. In this step, the uniformly dissolved high molecular weight polyester resin in the coating solution is converted into particles and precipitated into the UV-curable resin. After the coating film is dried, the UV-curable resin is cross-linked and cured by irradiating the plastic film with ultraviolet light, forming a cured resin layer. In this curing step, the high molecular weight polyester resin particles are fixed in the hardened coating layer, and protrusions are formed on the surface of the cured resin layer, increasing the surface roughness over a wide area.

[0052] Furthermore, the thickness of the curing resin layer is preferably in the range of 0.1 to 15 μm, more preferably in the range of 0.5 to 10 μm, and particularly preferably in the range of 1 to 8 μm. A thickness of 0.1 μm or more in the curing resin layer is preferable for the formation of sufficient protrusions. On the other hand, a thickness of 15 μm or less is preferable for good productivity. [Example]

[0053] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples at all. Furthermore, the various measurements and evaluations in the examples are performed by the methods described below. (1) Total light transmittance According to JIS-K7136-1:1997, the total light transmittance was measured using NDH-2000 manufactured by Nippon Denshoku Kogyo Co., Ltd.

[0054] (2) Surface resistivity The determination was performed according to JIS-K7194:1994 using a four-terminal method. The measuring instrument used was a Lotesta AX MCP-T370 manufactured by Mitsubishi Chemical Analysis Technology Co., Ltd.

[0055] (3) Average surface roughness SRa of the three-dimensional center plane The three-dimensional center surface average surface roughness SRa is specified in ISO 25178. It is calculated using a three-dimensional surface shape measuring device, VertScan (manufactured by Mitsubishi Kagaku Systems Co., Ltd., R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560nm, objective lens 10x)). Five measurements are taken, and their average value is calculated. Here, the first decimal place in nm is rounded. The three-dimensional surface roughness SRa of the transparent conductive film is considered X, and the three-dimensional surface roughness SRa of the transparent plastic film substrate on the opposite side to the transparent conductive film is considered Y.

[0056] (4) Crystal grain size Cut a 1mm × 10mm section from a sample of a thin film with a layer of transparent conductive film, with the conductive film facing out, and attach it to a suitable resin block. After trimming, use a standard ultrathin microtome to prepare an ultrathin section that is roughly parallel to the surface of the film. The section was observed using a transmission electron microscope (JEOL, JEM-2010). The conductive film surface without significant damage was selected and photographed at an accelerating voltage of 200 kV and a direct magnification of 40,000. In crystal grains observed under a transmission electron microscope, the longest portion of all crystal grains is measured, and the average of these measurements is taken as the crystal grain diameter. Here, Figures 1-4 show examples related to the method for determining the longest portion of a crystal grain during measurement. That is, the longest portion is determined by the length of the straight line that maximizes the measurement of the diameter of each crystal grain.

[0057] (5) Thickness of the transparent conductive film (film thickness) A 1mm × 10mm section was cut from a thin film sample with a layer of transparent conductive film and embedded in epoxy resin for electron microscopy. This section was then fixed in the sample holder of an ultramicrotome, and a thin section parallel to the short side of the embedded sample sample was prepared. Next, at a region of the thin film in this section without significant damage, a transmission electron microscope (JEOL Corporation, JEM-2010) was used to take photographs at an accelerating voltage of 200kV, a bright field of view, and a magnification of 10,000x. The film thickness was determined from the obtained photographs.

[0058] (6) Pen sliding durability test Using the transparent conductive film of this invention as one panel, and a transparent conductive film containing an indium-tin composite oxide film (tin oxide content: 10% by mass) with a thickness of 20 nm formed by sputtering on a glass substrate as another panel, a touch panel is fabricated by placing the two panels facing each other and separating them with epoxy resin beads of 30 μm diameter. Next, a 5.0 N load is applied to a polyacetal pen (tip shape: 0.8 mmR), and a linear sliding test of 180,000 reciprocations is performed on the touch panel. In this test, the pen load is applied to the transparent conductive film surface of this invention. The sliding distance is set to 30 mm, and the sliding speed is set to 180 mm / s. After this sliding durability test, the ON resistance (resistance value when the movable electrode (film electrode) contacts the fixed electrode) is measured when the sliding part is pressed with a pen load of 0.8 N. The ON resistance is preferably 10 kΩ or less. Furthermore, in the comparative examples, the films of each comparative example were used instead of the transparent conductive film of the present invention.

[0059] (7) Pen weight pressure test A transparent conductive film of the present invention, cut into 50mm × 50mm pieces, was used as one panel. Another panel consisted of a transparent conductive film containing an indium-tin composite oxide film (tin oxide content: 10% by mass) with a thickness of 20nm formed on a glass substrate by sputtering. The two panels were arranged with the transparent conductive films facing each other, separated by epoxy resin beads with a diameter of 30μm. Double-sided adhesive tape with a thickness adjusted to 120μm was used to attach the film-side panel and the glass-side panel to create a touch panel. A polyacetal pen (with a tip shape of 0.8mmR) was used to apply a 35N load at a position 2.0mm from the edge of the double-sided adhesive tape, and the pen was used to perform 10 linear slides (5 round trips) parallel to the tape. In this test, the load of the pen was applied to the transparent conductive film surface of the present invention. The sliding distance was set to 30mm, and the sliding speed was set to 20mm / second. However, the sliding was performed at a position without epoxy resin beads. After sliding, the transparent conductive film is removed, and the surface resistance at any five points on the sliding part is measured (using the four-terminal method), and the average value is calculated. When measuring the surface resistance, the four terminals are arranged perpendicular to the sliding part, with the sliding part positioned between the second and third terminals. The average surface resistance value of the sliding part is divided by the surface resistance value of the non-sliding part (measured using the four-terminal method), and the increase rate of the surface resistance value is calculated. Furthermore, in the comparative examples, the films of each comparative example were used instead of the transparent conductive film of the present invention.

[0060] (8) Determination of the tin oxide content in the transparent conductive film Cut a sample (approximately 15 cm²) and place it in a quartz Erlenmeyer flask. Add 20 ml of 6 mol / L hydrochloric acid and seal the flask with a thin film to prevent acid evaporation. Leave the flask at room temperature for 9 days with occasional shaking to allow the transparent conductive film to dissolve. Remove the remaining film and use the hydrochloric acid containing the dissolved film as the assay solution. The In and Sn concentrations in the solution were determined using an ICP-based luminescence analyzer (manufacturer: RIGAKU, model: CIROS-120 EOP) via calibration curve analysis. The wavelengths selected for each element were those with high sensitivity and no interference. The standard solutions were prepared by diluting commercially available In and Sn standard solutions.

[0061] (9) Adhesion test Implemented in accordance with JIS K5600-5-6:1999.

[0062] (10) Bending resistance test Implemented in accordance with JIS K5600-5-1:1999. However, if no cracking or spalling occurs up to 13mm in diameter of the mandrel, the bending resistance test is not performed for any diameter above that, and all diameters are recorded as 13mm.

[0063] (11) Through image clarity test According to JIS-K7105, the transmitted image clarity of transparent conductive films with comb widths of 0.125mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm was measured, and the sum of the transmitted image clarity for each comb width was calculated. The measuring instrument used was the SUGA ICM-1T image clarity measuring instrument.

[0064] The transparent plastic film substrate used in the examples and comparative examples was a biaxially aligned transparent PET film (Toyobo Co., Ltd. A4340, thickness listed in Table 1) with easy-adhesion layers on both sides. As a curing resin layer, 100 parts by weight of an acrylic resin (Dai Nippon Sei Chemical Co., Ltd., Seikabeam (registered trademark) EXF-01J) containing a photopolymerization initiator was mixed with the amount of silicon dioxide particles (Nissan Chemical Co., Ltd., Snowtex ZL) listed in Table 1. A toluene / MEK (8 / 2: mass ratio) mixed solvent was added at a solids concentration of 50% by mass, and the mixture was stirred until uniformly dissolved to prepare a coating solution (hereinafter referred to as coating solution A). The prepared coating solution was applied using a Mayer rod to a film thickness of 5 μm. After drying at 80°C for 1 minute, the coating is cured by irradiation with ultraviolet light (300 mJ / cm²) using an ultraviolet irradiation device (EYEGRAPHICS, UB042-5AM-W type). The cured resin layer is applied to both sides of the transparent plastic substrate.

[0065] (Examples 1-8) The leveling system of each embodiment is based on the conditions shown in Table 1 and is implemented as follows. A thin film was placed in a vacuum chamber and the vacuum was evacuated to 1.5 × 10⁻⁴ Pa. Then, after the oxygen was introduced, argon as an inert gas and hydrogen as a hydrogen-containing gas at the concentrations listed in Table 1 were introduced to bring the total pressure to 0.6 Pa. For sintering targets of indium-tin composite oxides or indium oxide sintering targets without tin oxide, a transparent conductive film is formed by DC magnetron sputtering with an applied power density of 3 W / cm². The film thickness is controlled by changing the speed at which the film passes over the target. Furthermore, the ratio of moisture pressure to inert gas in the film-forming environment during sputtering is measured using a gas analyzer (INFICON Transpector XPR3). In each embodiment, to adjust the ratio of moisture pressure to inert gas in the film-forming environment during sputtering, as shown in Table 1, the presence or absence of the bombardment step, the unevenness of the film roll end face, and the temperature of the temperature control medium of the temperature controller controlling the temperature of the central roller that contacts the film during travel are adjusted. The temperature exactly midway between the maximum and minimum temperatures from the start to the end of film formation on the film roll is recorded as the center value in Table 1. The thin film with a transparent conductive film layer was measured after undergoing the heat treatment described in Table 1. Table 1 shows the measurement results.

[0066] (Comparative Examples 1-9) Transparent conductive films were prepared under the same conditions as in Example 1, as described in Table 1, and evaluated. However, Comparative Example 7 did not include a curing resin layer. In Comparative Example 8, the thickness of the curing resin coating was adjusted to 20 μm. The results are shown in Table 2.

[0067] [Table 1A] Hydrogen concentration (%) (*1) (Moisture partial pressure / Argon partial pressure) central value (Moisture partial pressure / argon partial pressure) Difference between maximum and minimum values Oxygen flow rate / Argon flow rate Temperature control machine core temperature (°C) bombardment steps (*2) The end face of the film roll Concave and convex height difference (mm) The transparent conductive film contains Tin oxide content (quality%) Film thickness (nm) Heat treatment condition Example 1 0.01 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty one 165℃ 75 minutes Example 2 3 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty one 165℃ 75 minutes Example 3 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty one 165℃ 75 minutes Example 4 0.05 4.2×10⁻⁴ 2.8×10⁻⁴ 0.081667 -12 have 0 1 12 180℃ 75 minutes Example 5 0.05 1.9×10⁻³ 8.0×10-4 0.081667 0 have 9 10 30 150℃ 60 minutes Example 6 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty one 165℃ 75 minutes Example 7 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty one 165℃ 75 minutes Example 8 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty one 165℃ 75 minutes (*1) The hydrogen concentration is the value of hydrogen gas ÷ (argon + hydrogen gas) × 100. (*2) In the bombardment step, SUS (stainless steel) is used as the target and RF sputtering is performed at 0.5W / cm2.

[0068] [Table 1B] Full-light Transmission rate (%) surface resistance (Ω / □) Through the sum of image clarity (%) Adhesion test Bending resistance test (mm) Transparent plastic substrate thickness (μm) Inorganic particle addition amount of the curing resin layer directly beneath the transparent conductive film (wt%) X (nm) Inorganic particle addition amount of the curing resin layer on the opposite side of the transparent conductive film (wt%) Y (nm) (X³ + Y³)¹ / ³ (nm) Crystal grain size (nm) Degree of crystallinity (%) Pen glide durability Test ON resistor (kΩ) Pen weight pressure Durability test Example 1 87.5 562 440 No peeling 17 188 10 55 0.1 1 55 92 73 0.1 1.4 Example 2 86.9 452 430 No peeling 17 188 10 55 5 30 58 13 twenty one 9.2 1.0 Example 3 87.1 510 430 No peeling 17 188 10 55 5 30 58 61 60 0.4 1.0 Example 4 88.3 880 430 No peeling 17 188 10 55 5 30 58 15 20 9.0 1.0 Example 5 86.8 430 430 No peeling 17 188 10 55 5 30 58 95 75 0.1 1.4 Example 6 87.1 510 250 No peeling 17 188 20 100 twenty two 120 140 52 50 0.8 1.4 Example 7 87.1 510 493 No peeling 19 250 0.1 1 1 8 8 61 60 0.2 1.0 Example 8 87.1 510 410 No peeling 15 100 12 65 5 30 67 61 60 8.0 1.2

[0069] [Table 2A] Hydrogen concentration (%) (*1) (Moisture partial pressure / Argon partial pressure) central value (Moisture partial pressure / argon partial pressure) Maximum and minimum values difference Oxygen flow rate / Argon flow rate Temperature control machine core temperature (°C) bombardment steps (*2) The end face of the film roll Concave and convex height difference (mm) The transparent conductive film contains Tin oxide content (quality%) Film thickness (nm) Heat treatment condition Comparative Example 1 0 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 0 twenty one 165℃ 75 minutes Comparative Example 2 3.5 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 0 twenty one 165℃ 75 minutes Comparative Example 3 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 0 twenty four 165℃ 75 minutes Comparative Example 4 0.05 2.2×10⁻³ 1.2×10⁻³ 0.081667 2 none 12 11 9 180℃ 75 minutes Comparative Example 5 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 32 165℃ 75 minutes Comparative Example 6 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty four 165℃ 75 minutes Comparative Example 7 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty four 165℃ 75 minutes Comparative Example 8 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 31 165℃ 75 minutes Comparative Example 9 0.05 9.0×10-4 3.5×10⁻⁴ 0.081667 -12 have 5 3 twenty one 165℃ 75 minutes (*1) The hydrogen concentration is the value of hydrogen gas ÷ (argon + hydrogen gas) × 100. (*2) In the bombardment step, SUS (stainless steel) is used as the target and RF sputtering is performed at 0.5W / cm2.

[0070] [Table 2B] Full-light Transmission rate (%) surface resistance (Ω / □) Through the sum of image clarity (%) Adhesion test Bending resistance test (mm) Transparent plastic substrate thickness (μm) Inorganic particle addition amount of the curing resin layer directly beneath the transparent conductive film (wt%) X (nm) Inorganic particle addition amount of the curing resin layer on the opposite side of the transparent conductive film (wt%) Y (nm) (X³ + Y³)¹ / ³ (nm) Crystal grain size (nm) Degree of crystallinity (%) Pen glide durability Test ON resistor (kΩ) Pen weight pressure Durability test Comparative Example 1 87.1 950 430 No peeling 17 188 10 55 5 30 58 120 100 0.1 9.0 Comparative Example 2 86.7 423 430 No peeling 17 188 10 55 5 30 58 5 2 15 1.0 Comparative Example 3 87.1 630 430 No peeling 17 188 10 55 5 30 58 110 88 0.2 6.0 Comparative Example 4 86.5 412 430 No peeling 17 75 10 55 5 30 58 8 18 13 1.5 Comparative Example 5 87.1 510 430 No peeling 17 188 10 55 5 30 58 160 100 0.1 8.0 Comparative Example 6 87.1 510 238 No peeling 17 188 twenty two 120 twenty two 120 151 61 82 0.4 1.9 Comparative Example 7 87.1 510 474 No peeling 13 188 No hardened resin layer 0 5 30 30 61 82 0.4 1.9 Comparative Example 8 87.1 510 493 No peeling 20 188 0.1 1 1 8 8 155 100 0.4 2.1 Comparative Example 9 87.1 510 220 No peeling 17 188 20 100 26 145 159 52 50 0.8 1.4

[0071] As described in Tables 1A and 1B, the transparent conductive films described in Examples 1-8 exhibit excellent pen sliding durability, pen pressure resistance, and high precision, possessing all of these characteristics. However, as described in Table 2, Comparative Examples 1-9 do not fully meet the requirements for pen sliding durability, pen pressure resistance, and high precision. [Potential for industrial application]

[0072] As described above, according to the present invention, a transparent conductive film with excellent pen sliding durability, pen pressure resistance, and high precision can be produced, which is of great use in resistive film touch panels, etc.

[0073] 1: film 2: Central Roller 3: Chimney 4: Targets for indium-tin composite oxides

Claims

1. A transparent conductive film comprising a transparent conductive film having an indium-tin composite oxide transparent conductive film deposited on one side and a curable resin layer deposited on the other side of a transparent plastic film substrate, wherein the indium-tin composite oxide transparent conductive film has a crystal grain size of 10-100 nm, a crystallinity of 20-80%, contains 0.5-10% by mass of tin oxide, and a thickness of 10-30 nm; wherein the three-dimensional surface roughness SRa of the indium-tin composite oxide transparent conductive film is taken as X, and X is 1-100 nm; furthermore, wherein the three-dimensional surface roughness SRa of the curable resin layer on the opposite side of the transparent plastic film substrate is taken as Y, and (X3+Y3)1 / 3 is less than 140 nm.

2. The transparent conductive film of claim 1, wherein even if an adhesion test (JIS K5600-5-6:1999) is performed on the surface of the transparent conductive film, the transparent conductive film does not peel off, and when a bending resistance test (JIS K5600-5-1:1999) is performed on the transparent conductive film side of the indium-tin composite oxide of the transparent conductive film, the diameter of the mandrel that cracks or peels off when observed with a 10x magnifying glass is less than 20mm.

3. The transparent conductive film as claimed in claim 1 or 2, wherein the thickness of the transparent conductive film is 100 to 250 μm.

4. The transparent conductive film of claim 1 or 2, wherein a curable resin layer is present between the transparent conductive film of indium-tin composite oxide and the transparent plastic film substrate.

5. The transparent conductive film of claim 3, wherein a curable resin layer is present between the transparent conductive film of indium-tin composite oxide and the transparent plastic film substrate.

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