Transparent conductive film

Abstract

A transparent conductive film comprising a transparent conductive film of an indium-tin composite oxide laminated on at least one surface of a transparent plastic film substrate, wherein the transparent conductive film has an on-resistance of 10 kΩ or less as determined by a pen sliding durability test, an increase rate of surface resistance of 1.5 or less as determined by a pen weight pressure test, and an environmental stability evaluation value ES of 1.5 or less. 60 The environmental stability evaluation value ES is 0.5 or more and 1.5 or less. 90 It is 0.5 or more and 1.5 or less.

Description

Technical Field

[0001] The present invention relates to a transparent conductive film comprising a transparent conductive film of a crystalline indium-tin composite oxide laminated on a transparent plastic film substrate. In particular, the present invention relates to a transparent conductive film having excellent pen sliding durability, pen heavy pressure durability, and environmental stability when used in a resistive film touch panel. Background Art

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

[0003] Resistive film touch panels combine a fixed electrode (a transparent conductive film coated on a glass or plastic substrate) with a movable electrode (a membrane electrode) (a transparent conductive film coated on a plastic film). These electrodes are stacked on top of the display. Pressing the membrane electrode with a finger or pen causes the fixed electrode and the membrane electrode's transparent conductive film to come into contact, providing input for position recognition on the touch panel.

[0004] For example, as a means of improving the pen sliding durability, there is a method of making the transparent conductive thin film on the membrane electrode side crystalline (see Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-071171 Summary of the Invention

[0008] -Problems to be solved by the invention-

[0009] The conventional transparent conductive film described in Patent Document 1 attempts to improve pen sliding durability by controlling the crystallinity of indium-tin composite oxide. However, the conventional transparent conductive film is insufficient in the pen weight pressure durability test described below. Furthermore, the applications of resistive film touch panels have diversified in recent years, leading to demands for further improvement in pen sliding durability.

[0010] Compared to fingers, pens often apply greater force to touch panels. Continuous pen input can cause damage to the transparent conductive film on the membrane electrode side, such as cracks, peeling, and abrasion. Furthermore, if a touch panel is struck violently with a pen or input is performed with extreme force, applying forces greater than those typically assumed can also cause cracks, peeling, and other damage to the transparent conductive film.

[0011] To address these issues, there is a strong demand for transparent conductive films that combine excellent pen sliding durability with excellent pen weight pressure durability. Furthermore, there is a strong demand for transparent conductive films that can operate smoothly as resistive touch panels even in harsh environments such as high temperature, high humidity, and high temperature conditions.

[0012] In view of the above-mentioned conventional problems, an object of the present invention is to provide a transparent conductive film having excellent pen sliding durability and excellent pen weight pressure durability when used in a touch panel, and further having excellent environmental stability.

[0013] -Methods for solving the problem-

[0014] The present invention has been made in view of the above-mentioned circumstances, and the transparent conductive film of the present invention that can solve the above-mentioned problems has the following structure.

[0015] [1] A transparent conductive film comprising a transparent conductive film of an indium-tin composite oxide laminated on at least one surface of a transparent plastic film substrate, wherein the transparent conductive film has an on-resistance of 10 kΩ or less as measured by the following pen sliding durability test.

[0016] The rate of increase in the surface resistance of the transparent conductive film in the following pen weight pressure test is 1.5 or less.

[0017] The environmental stability evaluation value ES shown in the following formula 1 is 60 is greater than or equal to 0.5 and less than or equal to 1.5, and the environmental stability evaluation value ES shown in the following formula 2 90 It is 0.5 or more and 1.5 or less.

[0018] (Pen sliding durability test method)

[0019] The transparent conductive film of the present invention was used as one panel, and a transparent conductive film composed of an indium-tin composite oxide thin film (tin oxide content: 10% by mass) was used as the other panel. The indium-tin composite oxide thin film was formed on a glass substrate by sputtering and had a thickness of 20 nm. The two panels were arranged with epoxy beads of 30 μm in diameter so that the transparent conductive films faced each other. The film-side panel and the glass-side panel were adhered with double-sided tape of 170 μm thickness to produce a touch panel. Next, a load of 2.5 N was applied to a polyacetal pen (tip shape: 0.8 mmR), and a linear sliding test of 180,000 reciprocating strokes was performed on the touch panel. In this test, the load of the pen was applied to the transparent conductive film surface of the present invention.

[0020] The sliding distance at this time was 30 mm and the sliding speed was 180 mm / s. After the sliding durability test, the on-resistance (resistance value when the movable electrode (membrane electrode) and the fixed electrode are in contact) was measured when the sliding portion was pressed with a pen load of 0.8 N.

[0021] (Pen weight pressure test method)

[0022] The transparent conductive film of the present invention, cut into 50 mm x 50 mm pieces, was used as one panel, and a transparent conductive film composed of an indium-tin composite oxide film (tin oxide content: 10% by mass) was used as the other panel. The indium-tin composite oxide film was formed on a glass substrate by sputtering and had a thickness of 20 nm. The two panels were arranged with epoxy beads of 30 μm in diameter so that the transparent conductive films were opposite each other. The panel on the film side was attached to the panel on the glass side using double-sided tape adjusted to a thickness of 120 μm to produce a touch panel. A polyacetal pen (with a front end shape of 0.8 mmR) was used to apply a load of 35 N to a position 2.0 mm from the end of the double-sided tape, and a linear slide was performed 10 times (5 reciprocating times) parallel to the double-sided tape. In this test, the load of the pen was applied to the transparent conductive film surface of the present invention. The sliding distance at this time was 30 mm and the sliding speed was 20 mm / s. Sliding was performed at a position without epoxy beads. After sliding, remove the transparent conductive film and measure the surface resistance at five random locations on the sliding surface (4-probe method). The average value is calculated. When measuring the surface resistance, four probes are arranged perpendicular to the sliding surface, with the sliding surface positioned between the second and third probes. The average surface resistance value of the sliding surface is divided by the surface resistance value of the unslid surface (measured using the 4-probe method) to calculate the rate of increase in surface resistance.

[0023] (Environmental stability evaluation)

[0024] The transparent conductive film roll was cut into 100 mm pieces in the machine direction (MD) and the cut film was heat-treated at 165° C. for 75 minutes.

[0025] The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the heat-treated transparent conductive film are defined as R1S, and the average surface resistance values ​​of two points in the central region of the transparent conductive film are defined as R C S, the average value of the surface resistance values ​​of two points in the second end region located on the side opposite to the first end region is defined as R2S.

[0026] Next, the heat-treated transparent conductive film was further treated at 60°C and 95% RH for 240 hours under high temperature and high humidity conditions. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film treated at 60°C and 95% RH for 240 hours were defined as R1aE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film were defined as R C aE, and the average value of the surface resistance values ​​at two points in the second end region located on the side opposite to the first end region is defined as R2aE.

[0027] The transparent conductive film that had been heat-treated at 165°C for 75 minutes was further treated at 90°C for 240 hours. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film after treatment at 90°C for 240 hours was defined as R1bE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film was defined as R C bE, the average value of the surface resistance values ​​at two points in the second end region located on the side opposite to the first end region is defined as R2bE.

[0028] The value shown in the following formula 1 is defined as the environmental stability evaluation value ES 60 ,

[0029] The value shown in the following formula 2 is defined as the environmental stability evaluation value ES 90

[0030] [(R1aE / R1S)+(R C aE / R C S)+(R2aE / R2S)] / 3 (Formula 1)

[0031] [(R1bE / R1S)+(R C bE / R C S)+(R2bE / R2S)] / 3 (Formula 2)

[0032] [2] In one embodiment, the transparent conductive film of the present invention has a crystallite size of 10 to 100 nm, a crystallinity of 20 to 80%, and contains 0.5 to 10% by mass of tin oxide.

[0033] [3] In the transparent conductive film described in [1] or [2] above, the thickness of the transparent conductive film of the indium-tin composite oxide of the transparent conductive film of the present invention is 10 to 30 nm, the three-dimensional surface roughness SRa of the transparent conductive film of the indium-tin composite oxide is 1 to 100 nm, and the thickness distribution of the transparent conductive film in the width (TD) direction is less than 5%.

[0034] (Evaluation of Thickness Distribution in the Width (TD) Direction of the Transparent Conductive Film)

[0035] A transparent conductive film roll was cut into 50 mm sections in the longitudinal direction (MD). The thickness of the cut film was measured every 50 mm in the width direction (TD) from the extreme end. The thickness was measured until the opposite extreme end. The thickness distribution of the transparent conductive film was calculated using Equation 3.

[0036] Furthermore, the distance between the opposite end portion and the measurement location one point before the end portion may be less than 50 mm.

[0037] [(maximum value of the thickness of the transparent conductive film) - (minimum value of the thickness of the transparent conductive film)] ÷ (maximum value of the thickness of the transparent conductive film) × 100 (Formula 3)

[0038] [4] In one embodiment, the transparent conductive film of the present invention does not peel off even when an adhesion test (JIS K5600-5-6: 1999) is performed on the surface of the transparent conductive film.

[0039] The transparent conductive film side of the indium-tin composite oxide transparent conductive film was subjected to a bending resistance test (JIS K5600-5-1: 1999). When the bent portion was observed with a 10x magnifying glass, the mandrel diameter at which cracks or peeling occurred was less than 20 mm.

[0040] [5] In one embodiment, the transparent conductive film of the present invention has a thickness of 100 to 250 μm.

[0041] [6] In one embodiment, the transparent conductive film of the present invention has a curable resin layer between the transparent conductive film of indium-tin composite oxide and the transparent plastic film substrate.

[0042] -Effects of the Invention-

[0043] According to the present invention, both excellent pen sliding durability and excellent pen weight pressure durability are achieved, and excellent environmental stability is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram showing an example (part 1) of the longest portion of a crystal grain in the present invention.

[0045] Figure 2This is a schematic diagram showing another example (Part 2) of the longest portion of a crystal grain in the present invention.

[0046] Figure 3 This is a schematic diagram showing another example (part 3) of the longest portion of a crystal grain in the present invention.

[0047] Figure 4 This is a schematic diagram showing another example (fourth) of the longest portion of a crystal grain in the present invention.

[0048] Figure 5 This is a schematic diagram for explaining the position of a center roller in an example of a sputtering device preferably used in the present invention.

[0049] Figure 6 This is a schematic diagram showing an example of a test piece used for evaluation of environmental stability. DETAILED DESCRIPTION

[0050] The transparent conductive film of the present invention is a transparent conductive film in which a transparent conductive film of an indium-tin composite oxide is laminated on at least one surface of a transparent plastic film substrate. The transparent conductive film has an on-resistance of 10 kΩ or less as determined by the following pen sliding durability test.

[0051] The rate of increase in the surface resistance of the transparent conductive film in the pen weight pressure test described below is 1.5 or less.

[0052] The environmental stability evaluation value ES shown in the following formula 1 is 60 is greater than or equal to 0.5 and less than or equal to 1.5, and the environmental stability evaluation value ES shown in the following formula 2 90 It is 0.5 or more and 1.5 or less.

[0053] (Environmental stability evaluation)

[0054] The transparent conductive film roll was cut into 100 mm pieces in the machine direction (MD) and the cut film was heat-treated at 165° C. for 75 minutes.

[0055] The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the heat-treated transparent conductive film are defined as R1S, and the average surface resistance values ​​of two points in the central region of the transparent conductive film are defined as R C S, the average value of the surface resistance values ​​of two points in the second end region located on the opposite side to the first end region is defined as R2S.

[0056] Next, the heat-treated transparent conductive film was further treated at 60°C and 95% RH for 240 hours under high temperature and high humidity conditions. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film treated at 60°C and 95% RH for 240 hours were defined as R1aE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film were defined as R C aE, and the average value of the surface resistance values ​​at two points in the second end region located on the side opposite to the first end region is defined as R2aE.

[0057] The transparent conductive film that had been heat-treated at 165°C for 75 minutes was further treated at 90°C for 240 hours. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film after treatment at 90°C for 240 hours was defined as R1bE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film was defined as R C bE, the average surface resistance value of two points in the second end region opposite to the first end region is defined as R2bE. The value shown in the following formula 1 is defined as the environmental stability evaluation value ES 60 , the value shown in the following formula 2 is set as the environmental stability evaluation value ES 90 .

[0058] [(R1aE / R1S)+(R C aE / R C S)+(R2aE / R2S)] / 3 (Formula 1)

[0059] [(R1bE / R1S)+(R C bE / R C S)+(R2bE / R2S)] / 3 (Formula 2)

[0060] The transparent conductive film of the present invention exhibits excellent pen sliding durability and pen weight pressure durability. Furthermore, it has excellent environmental stability. The resulting transparent conductive film is extremely useful in applications such as resistive touch panels.

[0061] Pen sliding durability and pen weight pressure durability are opposite properties. First, the pen sliding durability is described. The transparent conductive film of indium-tin composite oxide with excellent pen sliding durability requires the transparent conductive film to have high crystallinity and large grain size, and then the three-dimensional surface roughness of the transparent conductive film is small. The three-dimensional surface roughness will be described later, and first the crystallinity and grain size will be described. The portion with circular or polygonal areas observed under a transmission electron microscope is defined as crystals (= grains) of the transparent conductive film, and the other portions are defined as amorphous. High crystallinity means a high proportion of crystals. A large grain size means that the circular or polygonal area observed under a transmission electron microscope is large. The transparent conductive film with high crystallinity has a high proportion of hard crystals, a large strain around the grains with large grain size, etc., so the transparent conductive film becomes hard and has excellent pen sliding durability.

[0062] According to the present invention, the transparent conductive film of the present invention disposed on the membrane electrode side can suppress damage such as cracking, peeling, and wear even when input is continuously performed on the touch panel using a pen.

[0063] Of course, the present invention can also achieve excellent sliding durability in finger input on a touch panel.

[0064] Next, we will explain durability against heavy pen pressure. Transparent conductive films made of indium-tin composite oxide, which exhibit excellent durability against heavy pen pressure, have low crystallinity and small grain size. This low crystallinity results in a high proportion of soft amorphous materials and reduced strain around the small grains. Consequently, even when a load is applied to the transparent conductive film, cracks are less likely to form, resulting in excellent durability against heavy pen pressure.

[0065] Compared to fingers, a pen often applies a stronger force to a touch panel. According to the present invention, even with pen input, the transparent conductive film of the present invention, which is located on the membrane electrode side, exhibits excellent durability against pen pressure. This allows the transparent conductive film to suppress damage such as cracking, peeling, and abrasion even when continuous pen input is applied to the touch panel.

[0066] Of course, the present invention can also have excellent heavy pressure durability in finger input on the touch panel.

[0067] As described above, it is known that pen sliding durability and pen weight pressure durability are contradictory properties. As a result of research, it was found that by controlling the crystallinity and grain size of the transparent conductive film, it is possible to achieve both pen sliding durability and pen weight pressure durability.

[0068] Furthermore, the present invention can provide a transparent conductive film having excellent environmental stability, and is particularly useful for applications such as resistive film touch panels.

[0069] Hereinafter, a transparent conductive film will be described that can achieve both durability against pen sliding and durability against pen weight pressure, and further has excellent environmental stability.

[0070] (Pen sliding durability test method)

[0071] The transparent conductive film of the present invention was used as one panel, and the other panel was a transparent conductive film composed of an indium-tin composite oxide thin film (tin oxide content: 10% by mass) formed on a glass substrate by sputtering and having a thickness of 20 nm. The two panels were arranged with epoxy beads having a diameter of 30 μm between them so that the transparent conductive films faced each other. The film-side panel and the glass-side panel were attached using a double-sided tape with a thickness of 170 μm to produce a touch panel. Next, a polyacetal pen (tip shape: 0.8 mmR) was applied with a load of 2.5 N, and a linear sliding test was performed on the touch panel with 180,000 reciprocating strokes. In this test, the pen load was applied to the transparent conductive film surface of the present invention.

[0072] The sliding distance at this time was 30 mm and the sliding speed was 180 mm / s. After the sliding durability test, the on-resistance (resistance value when the movable electrode (membrane electrode) and the fixed electrode are in contact) was measured when the sliding portion was pressed with a pen load of 0.8 N.

[0073] In the present invention, if the on-resistance of the transparent conductive film is 10 kΩ or less as determined by a pen sliding durability test, cracking, peeling, and wear of the transparent conductive film can be suppressed even with continuous pen input on the touch panel, which is preferable. In one embodiment, the on-resistance can be 9.5 kΩ or less, more preferably 5 kΩ or less. For example, the on-resistance can be 3 kΩ or less, 1.5 kΩ or less, and preferably 1 kΩ or less.

[0074] The on-resistance is preferably a smaller value, for example, 5 kΩ or more, or 3 kΩ or more. In one embodiment, it is 0 kΩ or more, for example, 0.05 kΩ or more.

[0075] By setting the on-resistance within such a range, even when input is continuously performed on the touch panel using a pen, cracks, peeling, abrasion, etc. on the transparent conductive film can be suppressed.

[0076] In one embodiment, these upper limits and lower limits may be appropriately combined.

[0077] (Pen weight pressure test method)

[0078] The transparent conductive film of the present invention, cut into 50mm x 50mm pieces, was used as one panel, and a transparent conductive film composed of an indium-tin composite oxide thin film (tin oxide content: 10% by mass) was used as the other panel. The indium-tin composite oxide thin film was formed on a glass substrate by sputtering and had a thickness of 20nm. The two panels were arranged with epoxy beads of 30μm in diameter so that the transparent conductive films faced each other. The panel on the film side was attached to the panel on the glass side using double-sided tape adjusted to a thickness of 120μm to produce a touch panel. A polyacetal pen (with a tip shape of 0.8mmR) was used to apply a load of 35N to a position 2.0mm from the end of the double-sided tape, and a linear slide was performed 10 times (5 reciprocating times) parallel to the double-sided tape. In this test, the load of the pen was applied to the surface of the transparent conductive film of the present invention. The sliding distance at this time was 30mm, and the sliding speed was 20mm / second. The slide was performed at a position without epoxy beads. After sliding, remove the transparent conductive film and measure the surface resistance at five random locations on the sliding surface (4-probe method). The average value is calculated. To measure the surface resistance, four probes are aligned perpendicular to the sliding surface, with the sliding surface positioned between the second and third probes. The average surface resistance value of the sliding surface is divided by the surface resistance value of the unslid surface (measured using the 4-probe method) to calculate the rate of increase in surface resistance.

[0079] In the present invention, the rate of increase in the surface resistance of the transparent conductive film, as measured by a pen weight pressure test, is preferably 1.5 or less. This characteristic prevents cracking and peeling of the transparent conductive film, even when subjected to a force greater than that normally assumed. More preferably, the rate of increase in the surface resistance is 1.2 or less, and particularly preferably 1.0 (no increase).

[0080] Here, the rate of increase in the surface resistance value of the transparent conductive film according to the present invention is preferably 1.0 or more.

[0081] In one embodiment, the on-resistance of the transparent conductive film based on a pen sliding durability test is greater than or equal to 0.05 and less than or equal to 9.5, and the rate of increase in the surface resistance value of the transparent conductive film based on a pen weight pressure (durability) test is greater than or equal to 1.0 and less than or equal to 1.5.

[0082] As mentioned above, pen sliding durability and pen weight pressure durability are generally contradictory properties. The present invention achieves a balanced balance between these two durability characteristics within this range. Furthermore, even with continuous pen input on the touch panel, cracking, peeling, and wear of the transparent conductive film can be suppressed. Furthermore, excellent durability can be demonstrated against loads caused by pen sliding and pen weight pressure. Furthermore, the numerical range can be selected from the ranges and values ​​described in this specification.

[0083] The transparent conductive film of the present invention preferably does not peel even when subjected to an adhesion test (JIS K5600-5-6:1999) on the transparent conductive film surface. A transparent conductive film that does not peel in an adhesion test is preferably a transparent conductive film that is in close contact with layers in contact with the transparent conductive film, such as the transparent plastic substrate and the curable resin layer, and thus is preferably a transparent conductive film that is prevented from cracking, peeling, or abrading even when input is continuously made to the touch panel using a pen. Furthermore, even when a force greater than that assumed for normal use is applied, cracking, peeling, or the like is prevented from occurring.

[0084] The transparent conductive film of the present invention preferably has an indium-tin composite oxide crystallite size of 10 to 100 nm and a crystallinity of 20 to 80%. A crystallite size of 10 nm or greater is preferred because the film is moderately hardened due to strain around the crystallite grains, resulting in excellent pen-slip durability. More preferably, the crystallite size of the indium-tin composite oxide is 30 nm or greater.

[0085] On the other hand, if the crystallite size of the transparent conductive film of indium-tin composite oxide is 100 nm or less, the transparent conductive film will not be too hard due to strain around the crystallite of the transparent conductive film, thus having excellent durability against heavy pen pressure, which is preferred. More preferably, the crystallite size of the transparent conductive film of indium-tin composite oxide is 90 nm or less.

[0086] In one embodiment, the crystal size of the transparent conductive film of indium-tin composite oxide is 10 nm to 95 nm, for example, 30 nm to 90 nm, for example, 40 nm to 80 nm.

[0087] For example, in the grain size observed under a transmission electron microscope, the longest part of all the grains is measured, and the average value of the measured values ​​is taken as the grain size. Figures 1 to 4 hereinafter shows an example of a method for identifying the longest portion of a crystal grain when measuring the longest portion of the crystal grain.

[0088] A transparent conductive film made of an indium-tin composite oxide with a crystallinity of 20% or higher is preferred because the film is moderately hard due to the presence of hard crystals, resulting in excellent pen-sliding durability. A transparent conductive film made of an indium-tin composite oxide with a crystallinity of 25% or higher is more preferred. On the other hand, a transparent conductive film made of an indium-tin composite oxide with a crystallinity of 80% or lower is preferred because the film contains a large amount of hard crystals but is not excessively hard, resulting in excellent pen-weight pressure durability.

[0089] In one embodiment, the crystallinity of the transparent conductive film of the indium-tin composite oxide is 25% or more and 78% or less, for example, 25% or more and 76% or less.

[0090] The transparent conductive film of the present invention preferably has a three-dimensional surface roughness SRa of 1 to 100 nm. A three-dimensional surface roughness SRa of 1 to 100 nm reduces surface protrusions, resulting in less deformation of the surface protrusions during a pen weight pressure test, which suppresses cracking of the transparent conductive film. Furthermore, even with a small amount of surface protrusions on the transparent conductive film, rollability of the film is maintained, which is preferred. A more preferred three-dimensional surface roughness SRa of 1 to 80 nm is further preferred. A three-dimensional surface roughness SRa of 1 to 65 nm is even more preferred.

[0091] The transparent conductive film of the present invention is composed of an indium-tin composite oxide, preferably containing 0.5% to 10% by mass of tin oxide. Tin oxide in the indium-tin composite oxide acts as an impurity for indium oxide. The presence of tin oxide as an impurity increases the melting point of the indium-tin composite oxide. Specifically, since the presence of tin oxide as an impurity acts to inhibit crystallization, it is an important factor that is strongly correlated with crystallinity properties such as grain size and crystallinity. A tin oxide content of 0.5% or more by mass is preferred, as the surface resistance of the transparent conductive film is at a practical level. A tin oxide content of 1% or more by mass is more preferred, and 2% or more by mass is particularly preferred. A tin oxide content of 10% or less by mass facilitates crystallization while maintaining the semi-crystalline state described below, resulting in improved pen-sliding durability. The tin oxide content is more preferably 8% or less by mass, further preferably 6% or less by mass, and particularly preferably 4% or less by mass. Furthermore, the surface resistance of the transparent conductive film of the present invention is preferably 50 to 900 Ω / sq, and more preferably 50 to 600 Ω / sq.

[0092] In the present invention, the thickness of the transparent conductive film is preferably not less than 10 nm and not more than 30 nm. The thickness of the transparent conductive film is an important factor that has a strong correlation with crystallinity such as grain size and crystallinity. If the thickness of the transparent conductive film is not less than 10 nm, the transparent conductive film will not be too amorphous, and it is easy to give the appropriate grain size and crystallinity to become a semi-crystalline state described later, and as a result, the pen sliding durability is maintained, which is preferred. It is more preferred that the thickness of the transparent conductive film is not less than 13 nm, and more preferably not less than 16 nm. In addition, if the thickness of the transparent conductive film is not more than 30 nm, the grain size of the transparent conductive film will not be too large, the crystallinity will not be too high, and it is easy to maintain a semi-crystalline state, and the pen weight pressure durability is maintained, which is preferred. It is more preferred that it is not more than 28 nm, and even more preferably not more than 25 nm.

[0093] The transparent conductive film of the present invention preferably has a mandrel diameter of less than 20 mm, which causes cracking or peeling when the bent portion is observed under a 10x magnifying glass in a bending resistance test (JIS K5600-5-1:1999) on the transparent conductive film side. A mandrel diameter of less than 20 mm is preferred because it prevents cracking in the layer in contact with the transparent conductive film during a pen-weight pressure test, and prevents cracks from forming in the transparent conductive film. More preferably, it is 18 mm or less. In one embodiment, the value in the bending resistance test is, for example, 15 mm or greater, 8 mm or greater, and preferably 1 mm or greater.

[0094] The transparent plastic film substrate of the transparent conductive film in the present invention preferably has a thickness of 100 to 250 μm, more preferably 130 to 220 μm. A plastic film thickness of 100 μm or greater is preferred because it maintains mechanical strength, minimizes deformation during pen input, and exhibits excellent resistance to pen sliding and pen weight pressure when used in touch panels. On the other hand, a thickness of 250 μm or less eliminates the need for significantly increased loads for positioning with pen input when used in touch panels.

[0095] The transparent conductive film in the present invention preferably has a curable resin layer between the transparent conductive film of indium-tin composite oxide and the plastic film substrate.

[0096] The presence of the curable resin layer can increase the adhesion of the transparent conductive film and disperse the force applied to the transparent conductive film, thereby suppressing cracks, peeling, wear, etc. on the transparent conductive film in the pen sliding test. Furthermore, it can suppress cracks, peeling, etc. on the transparent conductive film in the pen weight pressure test, and is therefore preferred.

[0097] The crystallinity of the transparent conductive film in the present invention is either too high or too low (such crystallinity is referred to as semi-crystalline or semi-crystalline). It is very difficult to stabilize the transparent conductive film and make it semi-crystalline. The reason is that the state in which the film is stopped midway during the rapid phase transition from amorphous to crystalline is semi-crystalline. Therefore, the film is sensitive to the water content in the film-forming atmosphere, a parameter related to crystallinity, and is particularly sensitive to the gas containing hydrogen atoms. Even if the gas containing hydrogen atoms or the water content in the film-forming atmosphere is slightly low, the film becomes almost completely crystalline (high crystallinity). On the contrary, if the gas containing hydrogen atoms or the water content in the film-forming atmosphere is slightly high, the film becomes amorphous (low crystallinity).

[0098] The transparent conductive film of the present invention is a transparent conductive film in which a transparent conductive film of an indium-tin composite oxide is laminated on at least one surface of a transparent plastic film substrate, wherein the environmental stability evaluation value ES represented by the following formula 1 is: 60 is greater than or equal to 0.5 and less than or equal to 1.5, and the environmental stability evaluation value ES shown in the following formula 2 90 It is 0.5 or more and 1.5 or less.

[0099] (Environmental stability evaluation)

[0100] The transparent conductive film roll was cut into 100 mm pieces in the machine direction (MD) and the cut film was heat-treated at 165° C. for 75 minutes.

[0101] The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the heat-treated transparent conductive film are defined as R1S, and the average surface resistance values ​​of two points in the central region of the transparent conductive film are defined as R c S, the average value of the surface resistance values ​​of two points in the second end region located on the side opposite to the first end region is defined as R2S.

[0102] Next, the heat-treated transparent conductive film was further treated at 60°C and 95% RH for 240 hours under high temperature and high humidity conditions. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film treated at 60°C and 95% RH for 240 hours were defined as R1aE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film were defined as R C aE, and the average value of the surface resistance values ​​at two points in the second end region located on the side opposite to the first end region is defined as R2aE.

[0103] In addition, the transparent conductive film that had been heat-treated at 165°C for 75 minutes was further treated at 90°C for 240 hours. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film after treatment at 90°C for 240 hours were set to R1bE, the average surface resistance values ​​of two points in the central region of the transparent conductive film were set to RCbE, and the average surface resistance values ​​of two points in the second end region located on the side opposite to the first end region were set to R2bE. The value shown in the following formula 1 was set to the environmental stability evaluation value ES 60 , the value shown in the following formula 2 is set as the environmental stability evaluation value ES 90 .

[0104] [(R1aE / R1S)+(R C aE / R C S)+(R2aE / R2S)] / 3 (Formula 1)

[0105] [(R1bE / R1S)+(R C bE / R C S)+(R2bE / R2S)] / 3 (Formula 2)

[0106] For example, environmental stability evaluation can also be based on Figure 6 The determination was carried out in the manner shown. Figure 6 In FIG. 5 , two “black circles” represent two points in the first end region along the longitudinal (MD) direction, and the average value of the surface resistance values ​​of the two points can be measured as R1S.

[0107] Likewise, in Figure 6 In the figure, the “black triangles” represent two points in the central region of the transparent conductive film, and the average surface resistance value at the two points is defined as R C S, can be measured.

[0108] In addition, Figure 6 In the figure, two "black squares" represent two points in the second end region located on the opposite side to the first end region along the longitudinal (MD) direction, and the average surface resistance value of the two points can be measured as R2S.

[0109] Figure 6 The measurement positions shown are merely examples, and two points in the first end region can be selected within the range assumed by common technical knowledge. Other measurement positions can also be appropriately selected in the same manner. Figure 6 The measurement position was evaluated at different positions.

[0110] In the transparent conductive film of the present invention, the environmental stability evaluation value ES shown in Formula 1 is60 is greater than or equal to 0.5 and less than or equal to 1.5, and the environmental stability evaluation value ES shown in the following formula 2 90 Since the ratio is 0.5 or more and 1.5 or less, the characteristics required for a touch panel, such as accurate input characteristics, can be satisfied even in severe environments such as high temperature and high humidity conditions (60°C and 95% RH) and high temperature conditions (90°C).

[0111] In particular, the present invention exhibits excellent physical properties even under high-temperature, high-humidity conditions (60°C, 95% RH) and high-temperature conditions (90°C). Therefore, even in enclosed spaces such as the interior of vehicles, such as during high temperatures and humidity during the rainy season, or during very high temperatures during summer, it can meet the characteristics required of a touch panel, such as accurate input characteristics. Furthermore, the transparent conductive film of the present invention has environmental stability evaluation values ​​represented by equations 1 and 2 within the aforementioned ranges, making it preferable for resistive touch panels to operate smoothly even in such harsh environments.

[0112] In one embodiment, the value shown in Formula 1 is set as the environmental stability evaluation value ES 60 The environmental stability evaluation value ES shown in Formula 1 is 1.5 or less, 1.3 or less, and preferably 1.2 or less. 60 It is 0.5 or more, can be 0.7 or more, and preferably 0.8 or more. In one embodiment, these upper limits and lower limits may be appropriately combined.

[0113] By making the environmental stability evaluation value ES 60 Within this range, the transparent conductive film of the present invention can meet the properties required for touch panels, such as accurate input characteristics and durability, even in harsh environments such as high temperature and high humidity (60°C and 95% RH). Furthermore, it can enable such resistive touch panels to operate without any problems, which is preferable.

[0114] In one embodiment, the value shown in Formula 2 is set as the environmental stability evaluation value ES 90 The environmental stability evaluation value ES shown in Formula 2 is 1.5 or less, 1.45 or less, and preferably 1.4 or less. 90 It is 0.5 or more, can be 0.7 or more, and preferably 0.8 or more. In one embodiment, these upper limits and lower limits may be appropriately combined.

[0115] By making the environmental stability evaluation value ES 60Within this range, the transparent conductive film of the present invention can meet the characteristics required for touch panels, such as accurate input characteristics and durability, even in harsh environments such as high temperatures (90°C). Furthermore, it can enable such resistive touch panels to operate without problems, which is preferable.

[0116] The transparent conductive film of the present invention is semi-crystalline in a state where the transparent conductive film stops during a rapid phase transition from amorphous to crystalline.

[0117] The present inventors have successfully made the transparent conductive film semi-crystalline and maintained uniform semi-crystallinity over the entire surface of the transparent conductive film. As a result, even after exposure to high temperature and high humidity conditions (60°C and 95% RH) for 240 hours, the deterioration of the semi-crystallinity can be suppressed. Furthermore, even after exposure to high temperature conditions (90°C) for 240 hours, the deterioration of the semi-crystallinity can be suppressed. As a result, the environmental stability evaluation value ES can be reduced to 100%. 60 and environmental stability evaluation value ES 90 All the results were 0.5 or more and 1.5 or less, and significant effects were also achieved in the pen sliding durability test and the pen weight pressure test.

[0118] The transparent conductive film of the present invention is semi-crystalline. The semi-crystalline state in the present invention is a state where a rapid phase transition from amorphous to crystalline is stopped midway.

[0119] The present inventors have succeeded in making the transparent conductive film semi-crystalline and maintaining uniform semi-crystallinity across the entire surface of the transparent conductive film. As a result, they have discovered that by making the transparent conductive film semi-crystalline as described in the present invention and making the thickness distribution in the width (TD) direction of the transparent conductive film more uniform, the environmental stability evaluation value ES can be improved. 60 and environmental stability evaluation value ES 90 Satisfy the given conditions.

[0120] The thickness distribution of the transparent conductive film of the present invention in the width (TD) direction is preferably 5% or less. The thickness distribution of the transparent conductive film in the width (TD) direction can be evaluated by the following method.

[0121] (Evaluation of Thickness Distribution in the Width (TD) Direction of the Transparent Conductive Film)

[0122] A transparent conductive film roll was cut into 50 mm sections in the longitudinal direction (MD). The thickness of the cut film was measured every 50 mm in the transverse direction (TD) from the extreme end. The thickness was measured until the opposite extreme end. The thickness distribution of the transparent conductive film was calculated using Equation 3.

[0123] {(maximum value of the thickness of the transparent conductive film) - (minimum value of the thickness of the transparent conductive film)} ÷ (maximum value of the thickness of the transparent conductive film) × 100 (Formula 3)

[0124] In addition, the distance between the opposite end portion and the point in front of the point may be less than 50 mm.

[0125] When the thickness distribution in the width (TD) direction of the transparent conductive film of the present invention is large, the environmental stability evaluation value ES 60 and environmental stability evaluation value ES 90 Easy to change. The reasons are as follows. In order to manufacture a transparent conductive film with high productivity, it is preferred to use a roll-to-roll sputtering device. If a film roll (transparent plastic film substrate) with a large thickness distribution in the width (TD) direction is placed in a roll-to-roll sputtering device, water and organic gases fall off unevenly with respect to the width (TD) direction of the film in the film roll. In other words, when a transparent conductive film is formed on the film, the amount of water and organic gas released from the film in the width (TD) direction of the film is different. In addition, if there is a lot of water and organic gas, the defects and hydroxyl groups in the transparent conductive film increase, which may cause changes in semi-crystallinity. As a result, if the thickness distribution in the width (TD) direction is large, the uniformity of the semi-crystallinity of the transparent conductive film in the width (TD) direction of the film is lost, and then the defects and hydroxyl groups increase, and the environmental stability evaluation value ES 60 and environmental stability evaluation value ES 90 Easy to change.

[0126] However, the effects of the present invention cannot be achieved simply by including the thickness distribution of the transparent conductive film in the width (TD) direction within a given range. In other words, the present invention also includes the evaluation results of the pen sliding durability test, the evaluation results of the pen weight pressure durability test, and the evaluation results of the environmental stability test within the scope of the present invention, thereby achieving a higher degree of various effects.

[0127] If the thickness distribution of the transparent conductive film of the present invention in the width (TD) direction is 5% or less, water and / or organic gas will be uniformly removed from the film roll in the width (TD) direction of the film in the film roll in a sputtering device, such as a roll-to-roll sputtering device. As a result, the semi-crystallinity becomes more uniform, and defects and hydroxyl groups are reduced, and the environmental stability evaluation value ES is reduced. 60 and environmental stability evaluation value ES 90 It satisfies the given conditions and is therefore preferred.

[0128] The thickness distribution in the width (TD) direction of the transparent conductive film is preferably as small as possible, and is, for example, 3% or more, or 1% or more, and preferably 0% or more. In one embodiment, these upper and lower limits may be appropriately combined.

[0129] The production method for obtaining the transparent conductive film of the present invention is not particularly limited, and for example, the following production methods can be preferably exemplified.

[0130] Sputtering is a preferred method for forming a transparent conductive film of a crystalline indium-tin composite oxide on at least one surface of a transparent plastic film substrate. To produce the transparent conductive film with high productivity, a so-called roller sputtering apparatus is preferably used, which is a shape in which a film roll is supplied and the film roll is wound after film formation. In the film-forming atmosphere, a gas containing hydrogen atoms (not specifically limited to any gas containing hydrogen atoms, such as hydrogen, ammonia, or a hydrogen + argon mixed gas, excluding water) is introduced into a mass flow controller in the amount described below. Furthermore, the film temperature during sputtering is set to below 0°C. A sintered target of an indium-tin composite oxide containing 0.5 to 10% by mass of tin oxide is used, and the thickness of the transparent conductive film of the indium-tin composite oxide is adjusted to 10 to 30 nm. The transparent conductive film is formed on a transparent plastic film having a three-dimensional surface roughness SRa of 1 to 100 nm. The gas containing hydrogen atoms in the film-forming atmosphere during sputtering has the effect of hindering the crystallization of the transparent conductive film. When hydrogen gas is passed through the film formation atmosphere, the value (hydrogen gas flow rate) ÷ (inert gas flow rate + hydrogen gas flow rate) × 100 (sometimes simply expressed as hydrogen concentration) is preferably 0.01 to 3.00%. The hydrogen concentration is, for example, 0.01% to 2.00%, or 0.01% to 1.00%.

[0131] By setting the hydrogen concentration within such a range, it is possible to contribute to obtaining good results in, for example, the on-resistance value of a pen sliding durability test and the pen weight pressing durability test.

[0132] In addition, as inert gases, helium, neon, argon, krypton, xenon, etc. can be mentioned. When the hydrogen concentration is 0.01 to 3.00%, the transparent conductive film becomes semi-crystalline, so it is preferred. When a gas containing hydrogen atoms other than hydrogen is used, the amount of hydrogen (= hydrogen molecules) can be converted from the amount of hydrogen atoms included in the gas containing hydrogen atoms. When the gas containing hydrogen atoms is precisely flowed in the film-forming atmosphere by a mass flow controller, by configuring the gas outlet so that the gas containing hydrogen atoms can be evenly blown in a direction perpendicular to the length direction of the film roller, it is easy to obtain a transparent conductive film that is difficult to be a mixture of a high-crystalline part and a low-crystalline part, and a uniform semi-crystalline transparent conductive film, so that a transparent conductive film with both excellent pen sliding durability and pen weight pressure durability can be appropriately obtained. It is known that if there is too much water in the film-forming atmosphere, the crystallinity of the transparent conductive film decreases, so the amount of water in the film-forming atmosphere is also an important factor.

[0133] When water and organic gas generated from the film are generated unevenly within the film surface, the semi-crystallinity of the transparent conductive film becomes uneven, and defects and hydroxyl groups increase, resulting in an environmental stability evaluation value ES. 60 and environmental stability evaluation value ES 90 As a countermeasure in the manufacturing method, it is preferable to continuously form at least two or more transparent conductive films on a film roll.

[0134] In one embodiment, the transparent conductive film precursor is formed to a thickness of 35 to 65% of the total thickness of the transparent conductive film. In the present invention, the transparent conductive film precursor obtained under such conditions is referred to as a seed layer.

[0135] Furthermore, when a gas containing hydrogen atoms is used in the formation of the seed layer, it is preferred to control the central value X of the ratio of the water partial pressure to the inert gas in the film forming atmosphere during sputtering onto the film roller (water partial pressure / inert gas partial pressure), that is, the value between the maximum and minimum values ​​of the above ratio, to 1.00×10-3~4.80×10-3.

[0136] The precursor of the transparent conductive film is formed into a film until the thickness of the precursor of the transparent conductive film is 35 to 65% of the total thickness of the transparent conductive film, that is, the transparent conductive film is formed on the substrate film by forming a film seed layer, thereby being able to fully suppress the generation of water and organic gas from the film, and being able to fully reduce the unevenness of the amount of water and / or organic gas generated from various locations within the surface of the film.

[0137] In addition, when using a gas containing hydrogen atoms, by controlling X to 1.00×10 -3 ~4.80×10 -3 The seed layer serves as a seed layer for growing a highly uniform semi-crystalline transparent conductive film within the film surface of the present invention. The seed layer may be a single layer or two or more layers.

[0138] While not intended to be construed as being limited to a particular theory, the present invention suppresses the decrease in crystallinity of the transparent conductive film, which can occur when a large amount of water and organic gas is generated from the film, and can maintain the desired semi-crystalline state. As a result, the increase in defects and hydroxyl groups in the transparent conductive film, which can cause deterioration under high temperature, high humidity, and high temperature, can be suppressed. The environmental stability evaluation value ES is estimated to be 60 and environmental stability evaluation value ES 90 Satisfy the given conditions.

[0139] In the present invention, for example, as a countermeasure based on the manufacturing method, it is preferred to continuously form at least two layers of transparent conductive films on a film roll. When the transparent conductive film is formed until the thickness of the transparent conductive film becomes 35% to 65% of the total thickness of the transparent conductive film, and further, when a gas containing hydrogen atoms is used, it is preferred to control the central value X (the value between the maximum and minimum values) of the partial pressure ratio of water to the inert gas in the film forming atmosphere during sputtering onto the film roll to be 1.00×10 -3 ~4.80×10 -3 By forming the transparent conductive film (seed layer) to a thickness of 35 to 65% of the total thickness of the transparent conductive film, the transparent conductive film is formed on the film, thereby sufficiently suppressing the generation of water and organic gas from the film. As a result, the increase of defects, hydroxyl groups, etc. in the transparent conductive film, which are the cause of deterioration under high temperature, high humidity, and high temperature, can be sufficiently reduced. In addition, when using a gas containing hydrogen atoms, by controlling X to 1.00×10 -3 ~4.80×10 -3 , becoming a seed layer for growing a semi-crystalline transparent conductive film with fewer defects, hydroxyl groups, etc. The seed layer may be a single layer or two or more layers. Next, when a transparent conductive film is formed on the seed layer until the thickness of the transparent conductive film reaches the target total thickness of the transparent conductive film, and further when a gas containing hydrogen atoms is used, it is preferred that the central value Y of the ratio of the partial pressure of water to the inert gas in the film-forming atmosphere during sputtering of the seed layer (partial pressure of water / partial pressure of inert gas), that is, the value between the maximum and minimum values ​​of the above ratio, is controlled to 0.15×10 -3 ~0.90×10 -3 .

[0140] Furthermore, the average Z of X and Y is preferably controlled to be between 0.58×10⁻³ and 2.80×10⁻³. The transparent conductive film may be a single layer or two or more layers above the seed layer. This results in a semicrystalline transparent conductive film with high in-plane uniformity. Furthermore, a semicrystalline transparent conductive film with high in-plane uniformity is obtained, resulting in a low surface resistance distribution.

[0141] Furthermore, regarding Z, if the difference between the maximum value and the minimum value from the start of film formation to the end of film formation is 1.00×10 -3The crystallinity uniformity of the transparent conductive film is maintained throughout the entire length of the film. For example, in addition to the rotary pumps, turbomolecular pumps, and cryogenic pumps commonly used as exhaust devices for sputtering machines, it is preferable to reduce the amount of water released from the film during film formation, such as during the bombardment process described below, by defining the height difference of the unevenness of the film roller end surface described below, or by attaching a protective film with low water absorption to the surface opposite to the surface on which the transparent conductive film is formed. This reduces the need for precise control of the water content, thereby ensuring a uniform amount of water released throughout the entire length of the film. Z also depends on the tin oxide content in the transparent conductive film of the indium-tin composite oxide and the thickness of the transparent conductive film. When the amount of tin oxide added to the transparent conductive film of the indium-tin composite oxide is high or the transparent conductive film is thin, Z is preferably set lower within the aforementioned range. Conversely, when the tin oxide content in the transparent conductive film of the indium-tin composite oxide is low or the transparent conductive film is thick, Z, which is the central value of the partial pressure of water relative to the inert gas, is preferably set higher within the aforementioned range.

[0142] The transparent conductive film is preferably formed on the transparent plastic film with the film temperature during sputtering being set to 0° C. or lower. The film temperature during film formation is replaced by the set temperature of a temperature controller that regulates the temperature of a center roller in contact with the traveling film.

[0143] Here, Figure 5 A schematic diagram showing an example of a sputtering device preferably used in the present invention, in which the film 1 traveling partially contacts the surface of the center roller 2 while traveling. An indium-tin sputtering target 4 is set via a chimney 3, and a thin film of indium-tin composite oxide is accumulated and stacked on the surface of the film 1 traveling on the center roller 2. Each target is separated by a separator 5. The center 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 gas from the film that disperses the crystallinity of the transparent conductive film can be suppressed, so that the crystallinity of the transparent conductive film from the beginning to the end of film formation is easily uniformed, which is preferred. When using a gas containing hydrogen atoms, the average Z of X and Y is preferably 0.58×10 -3 ~2.80×10 -3 When Z is within the above range, the crystallinity of the transparent conductive film is effectively inhibited by the gas containing hydrogen atoms, which is preferred. Furthermore, in order to achieve practical levels of surface resistance and total light transmittance of the transparent conductive film, it is preferred to add oxygen during sputtering. This manufacturing method primarily controls the crystallinity by minimizing the influence of water, a major factor that disrupts the crystallinity of the transparent conductive film, by utilizing a hydrogen-containing gas.

[0144] In controlling the moisture content when forming an indium-tin composite oxide film on a plastic film, it is preferable to actually observe the moisture content during film formation rather than to observe the achieved vacuum level for the following two reasons.

[0145] The first reason is that when a film is formed on a plastic film by sputtering, the film is heated and moisture is released from the film, so the moisture content in the film-forming atmosphere increases, which is greater than the moisture content measured when the vacuum degree is reached. Therefore, the moisture content at the time of film formation is more accurate than that expressed by the vacuum degree reached.

[0146] The second reason is the case of an apparatus that feeds a large amount 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 a vacuum tank as a roll, the water on the outer layer of the roll will easily fall off, but the water on the inner layer of the roll will be difficult to fall off. This is because the film roll stops when measuring the vacuum degree reached, but the film roll moves during film formation, so the inner layer of the film roll containing a large amount of water is rolled out, and thus the moisture content in the film-forming atmosphere increases, compared to the moisture content when the vacuum degree reached is measured. In the present invention, when controlling the moisture content in the film-forming atmosphere, it is possible to better cope with it by observing the ratio of the water pressure of the film-forming atmosphere during sputtering to the inert gas.

[0147] It is preferred that before forming the transparent conductive film, the film be subjected to a bombardment process. The so-called bombardment process refers to a process in which a voltage is applied to discharge and plasma is generated in a state where only an inert gas such as argon or a mixed gas of a reactive gas such as oxygen and an inert gas flows. Specifically, it is preferred to bond the film by RF sputtering using a SUS target or the like. Since the film is exposed to the plasma by the bombardment process, water and organic components are released from the film. When the transparent conductive film is formed, the water and organic components released from the film are reduced, so that the crystallinity of the transparent conductive film from the beginning to the end of film formation is easily uniformed, and the defective portion of the transparent conductive film of the transparent conductive thin film can be reduced, and the hydroxyl group and the like are reduced, so it is preferred. In addition, since the layer to which the transparent conductive film is connected is activated by the bombardment process, the adhesion of the transparent conductive film is improved, so the pen sliding durability and the pen weight pressure durability are improved, so it is preferred.

[0148] The height difference between the most convex and concave parts of the film roll end surface used to form the transparent conductive film is preferably 10 mm or less. A height difference of 10 mm or less reduces the unevenness in the release of water and organic components from the film end surface when the film roll is placed in a sputtering device. This facilitates uniform crystallinity of the transparent conductive film from the start to the end of film formation, reduces defects in the transparent conductive film, and reduces hydroxyl groups, etc., making this a preferred feature.

[0149] In the film (transparent plastic film substrate) for forming the transparent conductive film, it is preferred to attach a protective film with low water absorption to the opposite side of the surface on which the transparent conductive film is formed. By attaching a protective film with low water absorption, it is difficult to release gases such as water from the film substrate. As a result, the unevenness in the release of gases such as water is reduced, so that the crystallinity of the transparent conductive film from the beginning to the end of film formation is easily uniform, and the crystallinity within the surface of the transparent conductive film of the transparent conductive film is easily uniform, which is preferred. As the substrate for the protective film with low water absorption, polyethylene, polypropylene, cycloolefin, etc. are preferred.

[0150] In a method for forming a transparent conductive film of a crystalline indium-tin composite oxide on at least one surface of a transparent plastic film substrate, it is preferred to introduce oxygen gas during sputtering. Introducing oxygen gas during sputtering prevents problems caused by oxygen deficiency in the transparent conductive film of the indium-tin composite oxide, thereby reducing the surface resistance of the transparent conductive film and increasing the total light transmittance. Therefore, in order to achieve practical levels of surface resistance and total light transmittance of the transparent conductive film, it is preferred to introduce oxygen gas during sputtering. Furthermore, the total light transmittance of the transparent conductive film of the present invention is preferably 70 to 95%.

[0151] The transparent conductive film of the present invention is preferably formed by laminating a transparent conductive film of an indium-tin composite oxide on a transparent plastic film substrate, and then heat-treating it in an oxygen-containing atmosphere at 80 to 200°C for 0.1 to 12 hours. A temperature of 80°C or higher facilitates slightly increasing the crystallinity to achieve a semi-crystalline state, thereby improving pen-slip durability, which is preferred. A temperature of 200°C or lower is preferred to ensure the planarity of the transparent plastic film.

[0152] <Transparent plastic film substrate>

[0153] The transparent plastic film substrate used in the present invention refers to a film obtained by melt-extruding an organic polymer in a film form or extruding a solution, and stretching it in the longitudinal direction and / or the width direction as needed, cooling it, and heat-setting it. Examples of the organic polymer include polyethylene, polypropylene, polyethylene terephthalate, polyethylene 2,6-naphthalate, polytrimethylene 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, syndiotactic polystyrene, and norbornene-based polymers.

[0154] Among these organic polymers, preferred are polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalate, syndiotactic polystyrene, norbornene polymers, polycarbonate, polyarylate, etc. In addition, these organic polymers may be copolymerized with a small amount of monomers of other organic polymers, or may be blended with other organic polymers.

[0155] The transparent plastic film substrate used in the present invention may be subjected to surface activation treatment such as corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, or ozone treatment, within the scope of not impairing the purpose of the present invention.

[0156] Coating a curable resin layer on a transparent plastic film substrate allows the transparent conductive film to adhere firmly to the curable resin layer, dispersing the forces applied to the transparent conductive film. This is preferable because cracking, peeling, and abrasion of the transparent conductive film during a pen slide test are suppressed. Furthermore, cracking and peeling of the transparent conductive film during a pen weight pressure test are suppressed. Furthermore, forming the transparent conductive film on a curable resin layer with a surface having irregularities reduces the actual contact area between the transparent conductive film and the glass during a pen slide test. This improves the sliding properties between the glass surface and the transparent conductive film, enhances pen slide durability, and can be expected to improve film rollability and anti-Newton ring properties. However, excessive irregularities increase the deformation of the surface protrusions during a pen weight pressure test, potentially causing cracks in the transparent conductive film. Therefore, the three-dimensional surface roughness SRa of the transparent conductive film is preferably 1 to 100 nm. Details of the curable resin layer are described below.

[0157] Furthermore, the curable resin preferably used in the present invention is not particularly limited as long as it is a resin that cures by application of energy such as heating, ultraviolet irradiation, or electron beam irradiation, and examples thereof include silicone resins, acrylic resins, methacrylic resins, epoxy resins, melamine resins, polyester resins, and polyurethane resins. From the viewpoint of productivity, it is preferred to use an ultraviolet curable resin as the main component.

[0158] Examples of such ultraviolet curable resins include polyfunctional acrylate resins such as polyol acrylic acid or methacrylic acid esters, and polyfunctional urethane acrylate resins synthesized from diisocyanates, polyols, and hydroxyalkyl acrylates or methacrylates. If necessary, monofunctional monomers such as vinyl pyrrolidone, methyl methacrylate, and styrene may be added to these polyfunctional resins for copolymerization.

[0159] Furthermore, to improve the adhesion between the transparent conductive film and the curable resin layer, it is effective to treat the surface of the curable resin layer using the following methods. Specific methods include discharge treatment using glow light or corona discharge to increase carbonyl, carboxyl, or hydroxyl groups; and chemical treatment using acids or bases to increase polar groups such as amino, hydroxyl, and carbonyl groups.

[0160] Ultraviolet-curable resins are typically used with the addition of a photopolymerization initiator. Known compounds that absorb ultraviolet light and generate free radicals can be used as photopolymerization initiators without particular limitation. Examples of such photopolymerization initiators include various benzoins, phenyl ketones, and benzophenones. The amount of photopolymerization initiator added is typically preferably 1 to 5 parts by mass per 100 parts by mass of the ultraviolet-curable resin.

[0161] Furthermore, in the present invention, in addition to the curable resin as the main component, inorganic particles and organic particles are preferably used in the curable resin layer. By dispersing the inorganic particles and organic particles in the curable resin, it is possible to form unevenness on the surface of the curable resin, thereby improving the surface roughness over a wide area.

[0162] Examples of the inorganic particles include silica, and examples of the organic particles include polyester resins, polyolefin resins, polystyrene resins, and polyamide resins.

[0163] In addition to inorganic and organic particles, it is also preferable to use a resin that is incompatible with the curable resin in addition to the curable resin as a main component. By adding a small amount of this incompatible resin to the curable resin matrix, phase separation can be induced within the curable resin, dispersing the incompatible resin into particles. These dispersed particles of the incompatible resin can create irregularities on the curable resin surface, improving surface roughness over a wide area.

[0164] Examples of the incompatible resin include polyester resin, polyolefin resin, polystyrene resin, and polyamide resin.

[0165] Here, as an example, the mixing ratio when using inorganic particles in the curable resin layer is shown: 0.1 to 20 parts by mass of inorganic particles per 100 parts by mass of ultraviolet curable resin is preferred, 0.1 to 15 parts by mass is more preferred, and 0.1 to 12 parts by mass is particularly preferred.

[0166] If the amount of the inorganic particles added is 0.1 to 20 parts by mass per 100 parts by mass of the ultraviolet curing resin, the protrusions formed on the surface of the curing resin layer are too small, which can effectively impart three-dimensional surface roughness. When a pen weight pressure test is performed, the deformation of the surface protrusions becomes smaller, which inhibits the occurrence of cracks in the transparent conductive film. Furthermore, since there are a few surface protrusions on the transparent conductive film, the film rollability can also be maintained, which is preferred.

[0167] The UV-curable resin, photopolymerization initiator, and inorganic particles, organic particles, and non-compatible resins of the UV-curable resin are dissolved in a common solvent to prepare a coating liquid. The solvent used is not particularly limited. For example, alcohol solvents such as ethanol and isopropyl alcohol, 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 naphtha can be used alone or in combination. The greater the amount of solvent added to dissolve the UV-curable resin, photopolymerization initiator, and non-compatible resins of the inorganic particles, organic particles, and UV-curable resin, in other words, the lower the solids concentration, the smaller the thickness distribution of the cured resin layer, which is preferred.

[0168] The concentration of the resin component in the coating liquid can be appropriately selected in consideration of the viscosity and other factors depending on the coating method. For example, the combined amount of the UV-curable resin, photopolymerization initiator, and high-molecular-weight polyester resin in the coating liquid is typically 20 to 80% by mass. Furthermore, other known additives, such as silicone-based leveling agents, may be added to the coating liquid as needed.

[0169] In the present invention, the prepared coating liquid is applied to a transparent plastic film substrate. The coating method is not particularly limited, and conventionally known methods such as bar coating, gravure coating, and reverse coating can be used.

[0170] After application, the coating liquid undergoes a subsequent drying process, where the solvent is evaporated. During this process, the high-molecular-weight polyester resin, uniformly dissolved in the coating liquid, forms particles that precipitate within the UV-curable resin. After the coating is dried, the plastic film is irradiated with ultraviolet light, causing the UV-curable resin to crosslink and cure, forming a curable resin layer. During this curing process, the high-molecular-weight polyester resin particles become fixed within the hard coat layer, forming protrusions on the surface of the curable resin layer, increasing the surface roughness over a wide area.

[0171] The thickness of the curable resin layer is preferably in the range of 0.1 to 15 μm. A range of 0.5 to 10 μm is more preferred, and a range of 1 to 8 μm is particularly preferred. A curable resin layer thickness of 0.1 μm or greater is preferred for sufficient protrusion formation. On the other hand, a thickness of 15 μm or less is preferred for improved productivity. Furthermore, the thickness distribution of the curable resin layer is preferably 5% or less.

[0172] Example

[0173] Hereinafter, the present invention will be described in further detail with reference to Examples, but the present invention is not limited to these Examples. In addition, various measurements and evaluations in the Examples were performed by the following methods.

[0174] (1) Total light transmittance

[0175] The total light transmittance was measured using NDH-2000 manufactured by Nippon Denshoku Industries, Ltd. in accordance with JIS-K7361-1:1997.

[0176] (2) Surface resistance

[0177] The measurement was performed using a four-probe method in accordance with JIS-K7194: 1994. As the measuring instrument, Lotesta AX MCP-T370 manufactured by Mitsubishi Chemical Analytech Co., Ltd. was used.

[0178] (3) Average surface roughness SRa of the three-dimensional center plane

[0179] The three-dimensional center-plane average surface roughness (SRa) is specified in ISO 25178 and was determined using a three-dimensional surface profilometer (R5500H-M100, manufactured by Ryoka Systems Co., Ltd.) (measurement conditions: wave mode, measurement wavelength 560 nm, 10x objective lens). Five measurements were taken, and the average was calculated. Data in nm units were rounded to the first decimal place.

[0180] (4) Grain size

[0181] A film sample with a transparent conductive thin film layer was cut into a size of 1 mm x 10 mm and attached to the top surface of a suitable resin block with the conductive film facing outward. After trimming, ultrathin sections roughly parallel to the film surface were prepared using a standard ultramicrotome.

[0182] The section was observed using a transmission electron microscope (JEM-2010 manufactured by JEOL), and a portion of the surface of the conductive film without significant damage was selected and photographed at an accelerating voltage of 200 kV and a magnification of 40,000.

[0183] In the crystal grains observed under a transmission electron microscope, the longest part of all the crystal grains was measured, and the average value of the measured values ​​was taken as the crystal grain size. Figures 1 to 4 An example of a method for identifying the longest portion when measuring the longest portion of a crystal grain is shown in FIG. That is, the longest portion is identified based on the length of a straight line that can maximally measure the grain size of each crystal grain.

[0184] (5) Thickness of transparent conductive film (film thickness)

[0185] A film sample laminated with a transparent conductive thin film layer was cut into a size of 1 mm x 10 mm and embedded in epoxy resin for electron microscopy. This was fixed to the sample holder of an ultramicrotome, and thin sections were prepared with cross sections parallel to the short sides of the embedded sample. Next, a transmission electron microscope (JEOL, JEM-2010) was used to photograph a portion of the film without significant damage at an accelerating voltage of 200 kV and a bright field magnification of 10,000. The film thickness was determined from the resulting photographs.

[0186] (6) Pen sliding durability test

[0187] The transparent conductive film of the present invention was used as one panel, and a transparent conductive film composed of an indium-tin composite oxide thin film (tin oxide content: 10% by mass) was used as the other panel. The indium-tin composite oxide thin film was formed on a glass substrate by sputtering and had a thickness of 20 nm. The two panels were arranged so that the transparent conductive films faced each other with epoxy beads of 30 μm in diameter between them to produce a touch panel. Next, a load of 2.5 N was applied to a polyacetal pen (tip shape: 0.8 mmR), and a linear sliding test of 180,000 reciprocating strokes was performed on the touch panel. In this test, the pen load was applied to the transparent conductive film surface of the present invention. The sliding distance at this time was 30 mm, and the sliding speed was 180 mm / s. After the sliding durability test, the on-resistance (the resistance value when the movable electrode (membrane electrode) contacts the fixed electrode) was measured when the sliding part was pressed with a pen load of 0.8 N. The on-resistance is preferably 10 kΩ or less.

[0188] In addition, in the comparative examples, the film in each comparative example was used instead of the transparent conductive film according to the present invention.

[0189] (7) Pen weight pressure test

[0190] The transparent conductive film of the present invention was cut into 50 mm x 50 mm pieces and used as one panel. As the other panel, a transparent conductive film composed of an indium-tin composite oxide thin film (tin oxide content: 10% by mass) was used. The indium-tin composite oxide thin film was formed on a glass substrate by sputtering and had a thickness of 20 nm. The two panels were arranged with epoxy beads of 30 μm in diameter so that the transparent conductive films faced each other. The film-side panel and the glass-side panel were attached using double-sided tape adjusted to a thickness of 120 μm to produce a touch panel. A polyacetal pen (with a tip shape of 0.8 mmR) was used to apply a load of 35 N to a position 2.0 mm from the end of the double-sided tape. The pen was then slid linearly 10 times (5 reciprocating times) parallel to the double-sided tape. In this test, the pen load was applied to the surface of the transparent conductive film of the present invention. The sliding distance at this time was 30 mm and the sliding speed was 20 mm / s. The sliding was performed at a position without epoxy beads. After sliding, remove the transparent conductive film and measure the surface resistance at five random locations on the sliding surface (4-probe method). The average value is calculated. To measure the surface resistance, four probes are aligned perpendicular to the sliding surface, with the sliding surface positioned between the second and third probes. The average surface resistance value of the sliding surface is divided by the surface resistance value of the unslid surface (measured using the 4-probe method) to calculate the rate of increase in surface resistance.

[0191] In addition, in the comparative examples, the film in each comparative example was used instead of the transparent conductive film according to the present invention.

[0192] (8) Measurement of the Content of Tin Oxide in the Transparent Conductive Film

[0193] Cut the sample (about 15cm 2 ), add 20 ml of 6 mol / l hydrochloric acid to a quartz conical flask, and seal the film without volatilization of the acid. Leave it for 9 days while shaking it frequently at room temperature to dissolve the transparent conductive film. Take out the residual film, and use the hydrochloric acid in which the transparent conductive film is dissolved as the measurement liquid. In and Sn in the dissolved liquid are determined by the calibration curve method using an ICP emission analyzer (manufacturer name: Rigaku, device model: CIROS-120EOP). The measurement wavelength of each element is selected to have no interference and high sensitivity. In addition, the standard solution is used by diluting the commercially available standard solution of In and Sn.

[0194] (9) Adhesion test

[0195] Implemented in accordance with JIS K5600-5-6:1999.

[0196] (10) Bending resistance test

[0197] The test was conducted in accordance with JIS K5600-5-1: 1999. However, if cracking or peeling did not occur up to a mandrel diameter of 13 mm, the above bending resistance test was not performed and all the diameters were recorded as 13 mm.

[0198] (11) Environmental stability evaluation

[0199] The transparent conductive film roll was cut into 100 mm pieces in the machine direction (MD) and the cut film was heat-treated at 165° C. for 75 minutes.

[0200] The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the heat-treated transparent conductive film are defined as R1S, and the average surface resistance values ​​of two points in the central region of the transparent conductive film are defined as R C S, the average value of the surface resistance values ​​of two points in the second end region located on the side opposite to the first end region is defined as R2S.

[0201] Next, the heat-treated transparent conductive film was further treated at 60°C and 95% RH for 240 hours under high temperature and high humidity conditions. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film treated at 60°C and 95% RH for 240 hours were defined as R1aE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film were defined as R C aE, and the average value of the surface resistance values ​​at two points in the second end region located on the side opposite to the first end region is defined as R2aE.

[0202] The transparent conductive film that had been heat-treated at 165°C for 75 minutes was further treated at 90°C for 240 hours. The average surface resistance values ​​of two points in the first end region along the longitudinal direction (MD) of the transparent conductive film after treatment at 90°C for 240 hours was defined as R1bE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film was defined as R C bE, the average surface resistance value of two points in the second end region opposite to the first end region is defined as R2bE. The value shown in the following formula 1 is defined as the environmental stability evaluation value ES 60 , the value shown in the following formula 2 is set as the environmental stability evaluation value ES 90 , calculate the values.

[0203] [(R1aE / R1S)+(R C aE / R C S)+(R2aE / R2S)] / 3 (Formula 1)

[0204] [(R1bE / R1S)+(R c bE / R C S)+(R2bE / R2S)] / 3 (Formula 2)

[0205] In addition, the environmental stability evaluation is based on Figure 6 The determination was carried out in the manner shown. Figure 6 In the figure, the two "black circles" represent two points in the first end region along the length (MD) direction, the "black triangle" represents two points in the central region of the transparent conductive film, and the "black quadrilateral" represents two points in the second end region along the length (MD) direction, which is located on the opposite side of the first end region.

[0206] (12) Evaluation of Thickness Distribution in the Width (TD) Direction of the Transparent Conductive Film

[0207] A transparent conductive film roll was cut into 50 mm sections in the longitudinal direction (MD). The thickness of the cut film was measured every 50 mm in the TD direction, from the extreme end to the opposite extreme end. The thickness distribution of the transparent conductive film was calculated using Equation 3. However, the distance between the opposite extreme end and the point immediately before this point may be less than 50 mm.

[0208] The thickness of the transparent conductive film was measured with a micrometer.

[0209] [(maximum value of the thickness of the transparent conductive film) - (minimum value of the thickness of the transparent conductive film)] ÷ (maximum value of the thickness of the transparent conductive film) × 100 (Formula 3)

[0210] The transparent plastic film substrate used in the Examples and Comparative Examples was a biaxially oriented transparent PET film (A4340, manufactured by Toyobo Co., Ltd., thickness shown in Table 1) with an adhesive layer on both sides. The amount of silica particles (SNOWTEXZL, manufactured by Nissan Chemical Co., Ltd.) listed in Table 1 was mixed with 100 parts by mass of an acrylic resin containing a photopolymerization initiator (SEIKA Beam (registered trademark) EXF-01J, manufactured by Dainichi Seika Industries) as the curable resin layer. A toluene / MEK (8 / 2 mass ratio) mixture was added to the solid concentrations listed in Tables 1 and 2, and stirred to uniformly dissolve the mixture, thereby preparing a coating solution (hereinafter referred to as coating solution A). The prepared coating solution was applied using a Meyer bar so that the average thickness of the coating film at five random points was 5 μm. After drying at 80°C for 1 minute, the film was irradiated with ultraviolet light (light intensity: 300 mJ / cm) using an ultraviolet irradiation device (manufactured by EYEGRAPHICS, UB042-5AM-W model). 2 ) to cure the coating. In addition, the curable resin layer is provided on both sides of the transparent plastic substrate.

[0211] (Examples 1 to 8)

[0212] Each example level was carried out as follows under the conditions shown in Table 1.

[0213] Place the membrane in the vacuum tank and evacuate to 1.5×10 -4 Pa. Next, after the oxygen was introduced, argon gas as an inert gas and hydrogen gas as a hydrogen-containing gas were introduced at the concentrations shown in Table 1 to adjust the total pressure to 0.6 Pa.

[0214] At 4.5W / cm 2 Power is supplied to a sintered target of indium-tin composite oxide or a sintered target of indium oxide without tin oxide, and a seed layer is formed by a DC magnetron sputtering method, followed by a transparent conductive film. The film thickness is controlled by changing the speed at which the film passes over the target. In addition, the ratio of the water partial pressure to the inert gas in the film-forming atmosphere during sputtering is measured using a gas analyzer (manufactured by INF Conductive Co., Ltd., luggage XPR3). In each embodiment level, in order to adjust the ratio X, Y and the average Z of X and Y of the water partial pressure to the inert gas in the film-forming atmosphere during sputtering, as shown in Table 1, the presence or absence of a bombardment process, the presence or absence of a protective film, the height difference of the end face of the film roller, and the temperature of the heat medium of the temperature controller that controls the temperature of the center roller where the film contacts the movement are adjusted. The temperature exactly halfway between the maximum and minimum values ​​of the temperature from the start of film formation on the film roller to the end of film formation is recorded as the center value in Table 1.

[0215] The transparent conductive film was formed and laminated, and then subjected to the heat treatment described in Table 1A, and then measured. The measurement results are shown in Table 1B.

[0216] (Comparative Examples 1 to 11)

[0217] Under the conditions described in Table 1, transparent conductive films were produced and evaluated in the same manner as in Example 1. In Comparative Example 7, no curable resin layer was provided. In Comparative Example 8, the thickness of the curable resin layer was adjusted to 20 μm. The film formation conditions are shown in Table 2A, and the results are shown in Table 2B.

[0218] [Table 1A]

[0219]

[0220] [Table 1B]

[0221]

[0222] [Table 2A]

[0223]

[0224] [Table 2B]

[0225]

[0226] As shown in Table 1B, the transparent conductive films described in Examples 1 to 8 exhibited excellent pen sliding durability and pen weight pressure durability, possessing both properties. Furthermore, they performed well under both high-temperature and high-humidity conditions and high-temperature conditions, demonstrating excellent environmental stability.

[0227] However, as shown in Table 2B, Comparative Examples 1 to 11 could not achieve both pen sliding durability and pen weight pressing durability. Furthermore, they could not have excellent environmental stability.

[0228] -Industrial availability-

[0229] As described above, according to the present invention, a transparent conductive film having excellent pen sliding durability, pen weight pressure durability, and environmental stability can be produced, which is extremely useful for applications such as resistive film touch panels.

[0230] -Explanation of symbols-

[0231] 1. Membrane

[0232] 2. Center roller

[0233] 3. Chimney

[0234] 4. Indium-tin composite oxide target

[0235] 5. Chamber.

Claims

1. A transparent conductive film, A transparent conductive film of indium-tin composite oxide is laminated on at least one surface of a transparent plastic film substrate, wherein the transparent conductive film has an on-resistance of 10 kΩ or less as determined by the following pen sliding durability test. The rate of increase in the surface resistance of the transparent conductive film in the following pen weight pressure test is 1.5 or less. The environmental stability evaluation value ES shown in the following formula 1 is 60 is greater than or equal to 0.5 and less than or equal to 1.5, and the environmental stability evaluation value ES shown in the following formula 2 90 is greater than or equal to 0.5 and less than or equal to 1.5, In the pen sliding durability test method, The transparent conductive film is used as one panel, and a transparent conductive film composed of an indium-tin composite oxide thin film is used as the other panel. The indium-tin composite oxide thin film is formed on a glass substrate by sputtering and has a thickness of 20 nm. The tin oxide content is 10% by mass. The two panels were arranged with epoxy beads of 30 μm in diameter interposed therebetween so that the transparent conductive films faced each other, and the film-side panel and the glass-side panel were adhered with a double-sided tape of 170 μm thickness to produce a touch panel. Next, a linear sliding test was conducted on the touch panel with a polyacetal pen having a tip shape of 0.8 mmR and a load of 2.5 N applied to the transparent conductive film surface. The sliding distance at this time is 30mm and the sliding speed is 180mm / second. After the sliding durability test, the on-resistance when the sliding portion was pressed with a pen load of 0.8 N was measured. This on-resistance is the resistance value when the movable electrode, i.e., the membrane electrode, contacts the fixed electrode. In the pen weight pressure test method, The transparent conductive film cut into 50 mm × 50 mm was used as one panel, and a transparent conductive film composed of an indium-tin composite oxide thin film was used as the other panel. The indium-tin composite oxide thin film was formed on a glass substrate by sputtering and had a thickness of 20 nm. The tin oxide content was 10% by mass. The two panels were placed with epoxy beads of 30 μm in diameter interposed therebetween so that the transparent conductive films faced each other. The film-side panel and the glass-side panel were attached using double-sided tape adjusted to a thickness of 120 μm to produce a touch panel. A load of 35 N was applied to a position 2.0 mm from the end of the double-sided tape using a polyacetal pen. The pen was slid parallel to the double-sided tape 10 times, i.e., 5 times back and forth. In this test, the pen load was applied to the transparent conductive film surface. The sliding distance at this time is 30mm and the sliding speed is 20mm / second. Slide the film at a location without epoxy beads. After sliding, remove the transparent conductive film and measure the surface resistance at 5 random locations on the sliding portion using a 4-probe method. Calculate the average value. When measuring the surface resistance, four terminals are arranged perpendicular to the sliding portion so that the sliding portion comes between the second and third terminals. The average surface resistance value of the sliding portion is divided by the surface resistance value of the non-sliding portion measured using the four-terminal method to calculate the rate of increase in the surface resistance value. In the environmental stability evaluation, The transparent conductive film roll was cut into 100 mm lengths in the MD direction, and the cut film was heat-treated at 165° C. for 75 minutes. The average surface resistance values ​​of two points in the first end region along the longitudinal direction MD of the heat-treated transparent conductive film are defined as R1S, and the average surface resistance values ​​of two points in the central region of the transparent conductive film are defined as R C S, the average of the surface resistance values ​​of two points in the second end region located on the side opposite to the first end region is defined as R2S, Next, the heat-treated transparent conductive film was further treated at 60°C and 95% RH for 240 hours under high temperature and high humidity conditions. The average surface resistance values ​​of two points in the first end region of the transparent conductive film after treatment at 60°C and 95% RH for 240 hours are defined as R1aE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film are defined as R C aE, the average of the surface resistance values ​​of two points in the second end region located on the side opposite to the first end region is defined as R2aE, Furthermore, the transparent conductive film that had been heat-treated at 165° C. for 75 minutes was further treated at 90° C. for 240 hours. The average surface resistance values ​​of two points in the first end region along the longitudinal direction MD of the transparent conductive film after treatment at 90° C. for 240 hours are defined as R1bE, and the average surface resistance values ​​of two points in the central region of the transparent conductive film are defined as R C bE, the average of the surface resistance values ​​of two points in the second end region located on the side opposite to the first end region is defined as R2bE, The value shown in the following formula 1 is defined as the environmental stability evaluation value ES 60 , The value shown in the following formula 2 is defined as the environmental stability evaluation value ES 90 : [(R1aE / R1S)+(R C aE / R C S) + (R2aE / R2S)] / 3 (Formula 1) [(R1bE / R1S) + (R C bE / R C S) + (R2bE / R2S)] / 3 (Equation 2), The transparent conductive film of the indium-tin composite oxide has a crystallite size of 10 to 100 nm, a crystallinity of 20 to 80%, and contains 0.5 to 10% by mass of tin oxide. The transparent conductive film of indium-tin composite oxide has a thickness of 10 to 30 nm, a three-dimensional surface roughness SRa of 1 to 100 nm, and a thickness distribution in the width TD direction of the transparent conductive film of 5% or less.

2. The transparent conductive film according to claim 1, wherein In the evaluation of the thickness distribution in the width TD direction of the transparent conductive film, The transparent conductive film roll was cut into 50 mm lengths in the longitudinal direction (MD). The thickness of the cut film was measured every 50 mm in the width direction (TD) from the extreme end. The thickness was measured until the opposite extreme end. The thickness distribution of the transparent conductive film was calculated using Equation 3. [(maximum value of the thickness of the transparent conductive film)−(minimum value of the thickness of the transparent conductive film)]÷(maximum value of the thickness of the transparent conductive film)×100 (Formula 3).

3. The transparent conductive film according to claim 1 or 2, wherein: Even when the adhesion test (JIS K5600-5-6: 1999) was performed on the surface of the transparent conductive film, the transparent conductive film did not peel off. The transparent conductive film side of the indium-tin composite oxide transparent conductive film was subjected to a bending resistance test (JIS K5600-5-1:1999). When the bent portion was observed with a 10x magnifying glass, the mandrel diameter at which cracks or peeling occurred was less than 20 mm.

4. The transparent conductive film according to claim 1 or 2, wherein: The thickness of the transparent conductive film is 100 to 250 μm.

5. The transparent conductive film according to claim 1 or 2, wherein: A curable resin layer is provided between the transparent conductive film of indium-tin composite oxide and the transparent plastic film substrate.

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