Transparent conductive film

Abstract

To provide a transparent conductive film having excellent suitable input intensity and input stability.SOLUTION: There is provided a transparent conductive film in which a transparent conductive film of indium-tin complex oxide is laminated on at least one face of a transparent plastic film substrate. An input start load is larger than 15 g and 25 g or less, and a voltage loss time is 0.00 milliseconds or more and 0.40 milliseconds or less. It is preferable that film bending resistance (BR) is 0.38 N cm or more and 0.90 N cm or less, an average (AVSp) of the maximum ridge height Sp of a conductive face satisfy the following formula (2-1). 4.7×BR-3.6≤AVSp<4.7×BR-1.8 ... formula (2-1) (in the formula, BR denotes the film bending resistance (N cm), AVSp denotes the average maximum ridge height (μm)SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transparent conductive film in which a transparent conductive film of indium-tin composite oxide is laminated on a transparent plastic film substrate. [Background technology]

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

[0003] A resistive touch panel combines a fixed electrode, which is a glass or plastic substrate coated with a transparent conductive thin film, with a movable electrode (called a film electrode), which is a plastic film coated with a transparent conductive thin film. These are used by overlapping them on top of the display. When a finger or pen presses on the film electrode (this is called input), the transparent conductive thin films of the fixed electrode and the film electrode come into contact, and the input position is recognized.

[0004] Patent Document 1 discloses a transparent conductive laminate for touch panels, in which a transparent conductive film mainly composed of substantially crystalline indium oxide is laminated on at least one surface of a polymer film. It is stated that the writing durability is improved by crystallizing the indium oxide. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2004-071171 [Overview of the project] [Problems that the invention aims to solve]

[0006] Touch panels require properties (pen friction durability) that prevent cracking, peeling, or wear of the transparent conductive film even when continuously input with a pen. Furthermore, touch panels require an appropriate range of input strength (optimal input strength). For example, with resistive touch panels, when pressing the film electrode with a finger or pen to bring the transparent conductive thin film of the fixed electrode and the film electrode into contact, the hand or sleeve of clothing may accidentally touch the touch panel, or the user may accidentally touch the touch panel with a pen or other object when hesitating about where to touch. It is desirable to minimize input due to such unintended contact with the touch panel (error prevention). However, improving error prevention tends to reduce comfortable input. Comfortable input means that when inputting with a pen or finger on a resistive touch panel, input can be made without consciously applying strong force. A balance between error prevention and comfortable input is required.

[0007] Furthermore, touch panels require excellent input stability, meaning that input to the touch panel remains stable from the moment a pen or other object touches it until it is lifted. For example, they should be able to reduce the blurring of characters that can occur when typing characters continuously (speed typing), and ensure that the strokes of characters do not blur (stroke input performance). In the technology described in Patent Document 1, pen sliding durability could not be improved if indium oxide was not crystallized. Furthermore, conventional transparent conductive films, including those described in Patent Document 1, did not adequately provide suitable input strength (prevention of incorrect input, comfortable input) or input stability (fast writing, smooth stroke input).

[0008] Therefore, an object of the present invention is to provide a transparent conductive film with excellent appropriate input strength and input stability. A further preferred object of the present invention is to provide a transparent conductive film that also has pen sliding durability. [Means for solving the problem]

[0009] The present invention has been made in view of the above circumstances, and the transparent conductive film of the present invention, which is able to solve the above problems, has the following configuration. [1] A transparent conductive film in which a transparent conductive film of indium-tin composite oxide is laminated on at least one surface of a transparent plastic film substrate, The input starting load determined by test method 1 is greater than 15g and 25g or less. A transparent conductive film having a voltage loss time of 0.00 milliseconds or more and 0.40 milliseconds or less, as determined by test method 2. [Test Method 1] A 20nm thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) is formed on one side of a glass substrate. On the surface of this thin film, epoxy resin dot spacers (60μm x 60μm x 5μm high) are formed in a square grid pattern at 4mm intervals to form a panel. An evaluation panel is fabricated by layering transparent conductive films on the conductive film side of this panel, with an adhesive rectangular frame 105μm thick and with an inner circumference of 190mm x 135mm, so that the conductive films face each other. From the transparent conductive film side of this evaluation panel, the center of the four-point grid of dot spacers is pressed with a hemispherical polyacetal pen with a radius of 0.8mm at its tip, and the pressure at which the resistance value begins to stabilize is defined as the input starting load. [Test Method 2] The evaluation panel is connected to a 6V constant voltage power supply, and a pen with a hemispherical tip with a radius of 0.8 mm is used to press the center of the four-point grid of the dot spacer from the transparent conductive film side with a load of 50 gf at intervals of 5 times / second. The time from when the pen begins to lift off the transparent conductive film and the voltage decreases from 6V to when the voltage returns to 5V is measured and defined as the voltage loss time. [2] The film stiffness (BR) determined by test method 3 is 0.38 N·cm or more and 0.90 N·cm or less. The average (AVSp) of the maximum peak height Sp of the conductive surface determined by test method 4 satisfies the following equations (2-1) and (2-2): The transparent conductive film described in [1] in which the contact area ratio (CA) obtained by Test Method 5 satisfies the following formula (2-3). 4.7×BR - 3.6 ≤ AVSp < 4.7×BR - 1.8 … Formula (2-1) 0.005 ≤ AVSp ≤ 12.000 … Formula (2-2) CA ≥ 32.6×BR + 17.2 … Formula (2-3) (In the formula, BR is the film stiffness (N·cm), AVSp is the average maximum peak height (μm), and CA is the contact area ratio (%)) [Test Method 3] Place a 20 mm × 250 mm transparent conductive film test piece with the transparent conductive film facing up on a horizontal table, protrude the test piece 230 mm in length from the edge of the table, and determine the stiffness (BR) based on the following formula. Stiffness (BR (N·cm)) = g × a × b × L 4 / (8 × δ × 10 11 ) (In the formula, g is 9.81 (acceleration due to gravity; m / s 2 ), a is 20 (length of the short side of the test piece; mm), b represents the specific gravity of the test piece (g / cm 3 ), L is 230 (length of the long side of the test piece protruding outside the horizontal table; mm), and δ represents the difference in height between the tip of the test piece and the height of the table (cm)) [Test Method 4] Determine a total of 5 measurement points at 3 points at 1 cm intervals in the MD direction and 2 points symmetrically in the TD direction at 1 cm intervals from the center on the conductive surface of the transparent conductive film, measure the maximum peak height Sp (conforming to ISO 25178) due to surface roughness at each location, and take the average value as the average maximum peak height (AVSp) (μm). [[ID=***]] [Test Method 5] For the conductive surface of a transparent conductive film, the average height Rc (μm), maximum peak height Rp (μm), and average length Rsm (μm) are measured based on line roughness. The arithmetic mean height Ra (μm) based on line roughness is measured at locations that satisfy at least one of equations (X1) and (X2) and equation (X3). The average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) are determined using a 3D surface shape measuring device, BurtScan (manufactured by Ryoka Systems, R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560nm, objective lens 50x)). The determination of the maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) follows the provisions of JIS B 0601-2001. The measurement length for the arithmetic mean height Ra (μm) shall be between 100 μm and 200 μm. Rp-Rc-Ra≦0.20…Formula (X1) (Rp-Rc) / Ra≦5.0…Formula (X2) Rsm≦30…Formula (X3) The objective lens of the aforementioned 3D surface shape measuring device, BartScan, was changed to 10x magnification, and the particle analysis function in the same measuring device was used to determine the arithmetic mean height Ra(μm) from the average surface - 15 × 10 -3 The sample is sliced ​​in a planar direction at a height of (μm) - average height Rc(μm), and the sum of the cross-sectional areas is calculated. The contact area ratio (CA) (%) is calculated by dividing the sum of the cross-sectional areas by the area of ​​the measurement field and multiplying the result by 100. [3] The maximum value MXSp of the maximum peak height Sp determined by the above test method 4 is greater than 1.0 times and less than or equal to 1.4 times the average maximum peak height AVSp, and, The transparent conductive film according to [2], wherein the minimum value MNSp of the maximum peak height Sp determined by the test method 4 is 0.6 times or more and 1.0 times or less of the average maximum peak height AVSp. [4] A transparent conductive film according to any one of [1] to [3], wherein the thickness of the transparent conductive film is 10 nm or more and 100 nm or less. [5] A transparent conductive film according to any one of [1] to [4], wherein the concentration of tin oxide contained in the transparent conductive film is 0.5% by mass or more and 40% by mass or less. [6] A curable resin layer is provided between a transparent conductive film and a transparent plastic film substrate. Furthermore, the transparent conductive film according to any one of [1] to [5] has a functional layer on the side of the transparent plastic substrate opposite to the transparent conductive film. [7] A transparent conductive film according to any one of [1] to [6], having an easy-adhesion layer on at least one side of a transparent plastic film substrate. [8] The transparent conductive film according to [7], wherein the easy-adhesion layer is disposed at least one of the positions between the transparent plastic film substrate and the curable resin layer, or between the transparent plastic substrate and the functional layer. [9] A transparent conductive film as described in any of [1] to [8], wherein the ON resistance determined by test method 6 is 10 kΩ or less. [Test Method 6] An evaluation panel is created by layering a panel plate, on which a 20 nm thick indium-tin composite oxide conductive film (tin oxide content: 10 mass%) is formed on one side of a glass substrate, with a transparent conductive film, and epoxy beads with a diameter of 30 μm, so that the conductive films face each other. The transparent conductive film side of this evaluation panel is slid with a hemispherical polyacetal pen with a radius of 0.8 mm at its tip, while applying a load of 2.5 N (50,000 reciprocating cycles, sliding distance 30 mm, sliding speed 180 mm / sec). After sliding, the resistance (ON resistance) is measured when the sliding part is held down with a pen load of 0.8 N and electrically connected.

[10] A transparent conductive film as described in any of [1] to [9], wherein, in an adhesion test on the surface of the transparent conductive film in accordance with JIS K5600-5-6:1999, the remaining area ratio of the transparent conductive film is 95% or more. [Effects of the Invention]

[0010] According to the present invention, a transparent conductive film with excellent appropriate input strength and input stability can be provided. Furthermore, according to the present invention, preferably, a transparent conductive film with pen sliding durability can also be provided. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic side view showing an example of the transparent conductive film of the present invention. [Figure 2] Figure 2 is a schematic side view showing another example of the transparent conductive film of the present invention. [Figure 3] Figure 3 is a schematic side view showing yet another example of the transparent conductive film of the present invention. [Figure 4] Figure 4 is a schematic side view showing another example of the transparent conductive film of the present invention. [Figure 5] Figure 5 is a conceptual diagram showing the relationship between voltage and time in one aspect of the present invention. [Figure 6] Figure 6 is a schematic diagram of an apparatus showing an example of the film deposition method of the present invention. [Figure 7] Figure 7 is a schematic plan view partially enlarged to illustrate the input start load measurement method in the present invention. [Figure 8] Figure 8 is a schematic plan view of a partially enlarged section illustrating the pen sliding durability measurement method in the present invention. [Figure 9] Figure 9 is a schematic plan view illustrating the pen sliding durability measurement method in the present invention. [Modes for carrying out the invention]

[0012] 1. Transparent conductive film The transparent conductive film of the present invention has a transparent conductive film of indium-tin composite oxide laminated on at least one surface of a transparent plastic film substrate. Because it has a transparent conductive film on its surface, it can be widely used in electrical and electronic applications, such as flat panel displays like liquid crystal displays and electroluminescent (EL) displays, and as transparent electrodes for touch panels, taking advantage of its conductivity. The specific layer configuration of the transparent conductive film can be set as appropriate; for example, the configurations shown in the schematic side views of Figures 1, 2, 3, and 4 are examples.

[0013] The transparent conductive film in Figure 1 has a transparent conductive film 5 formed on one side of a transparent plastic film substrate 7 via a curable resin layer 6, and a functional layer 8 formed on the opposite side of the transparent plastic film substrate 7. Forming the curable resin layer 6 between the transparent conductive film 5 and the transparent plastic film substrate 7 prevents monomers and oligomers from precipitation from the transparent plastic film substrate 7 onto the transparent conductive film 5. The transparent conductive film of the present invention has improved appropriate input strength and input stability through control of the input start load and voltage loss time, as described later, and the appropriate input strength and input stability are further improved by blocking the precipitation of oligomers. In addition, the transparency and visibility of the transparent conductive film can be further improved by preventing the precipitation of monomers and oligomers with the curable resin layer 6 and the functional layer 8. Furthermore, the rigidity of the transparent conductive film can be adjusted by having the curable resin layer 6 and / or the functional layer 8, as described later. Note that the curable resin layer 6 and / or the functional layer 8 are not necessarily required depending on the rigidity of the transparent plastic film substrate.

[0014] In one embodiment, the transparent conductive film of the present invention has an easy-adhesion layer laminated on at least one side of a transparent plastic film substrate. For example, as shown in Figure 2, the curable resin layer 6 and the transparent plastic film substrate 7 may be bonded together with the easy-adhesion layer 9. As shown in Figure 3, the functional layer 8 and the transparent plastic film substrate 7 may be bonded together with the easy-adhesion layer 9. As shown in Figure 4, the curable resin layer 6 and the functional layer 8 may each be bonded together with the transparent plastic film substrate 7 with the easy-adhesion layer 9. The presence of the easy-adhesion layer 9 further effectively suppresses the peeling of the curable resin layer 6 and / or the functional layer 8 from the transparent plastic film substrate 7 by external force.

[0015] The transparent conductive film of the present invention is characterized in that the input starting load determined by test method 1 is greater than 15g and 25g or less (Feature 1). By keeping the input starting load below a predetermined value, comfortable input can be improved.

[0016] [Test Method 1] A 20nm thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) is formed on one side of a glass substrate, and epoxy resin dot spacers (60μm x 60μm x 5μm high) are formed on the surface of this thin film in a square grid pattern at 4mm intervals to form a panel. An adhesive rectangular frame with a thickness of 105μm and an inner circumference of 190mm x 135mm is sandwiched between these panels, and a transparent conductive film is layered on top of it so that the conductive films face each other to create an evaluation panel. From the transparent conductive film side of this evaluation panel, the center of the four-point grid of dot spacers is pressed with a hemispherical polyacetal pen with a radius of 0.8mm at its tip, and the pressure at which the resistance value begins to stabilize is defined as the input starting load. Here, "stable resistance value" means ,flat This means that the resistance value fluctuates within a range of ±5% of the average value.

[0017] Furthermore, the transparent conductive film is characterized by having a voltage loss time of 0.00 milliseconds or more and 0.40 milliseconds or less, as determined by test method 2 (characteristic 2). Having a voltage loss time within a predetermined range allows for a longer electrically stable contact time. By setting the input start load within a predetermined range, the ability to prevent incorrect inputs can be enhanced, and by setting the voltage loss time within a predetermined range, input stability such as stroke stability and speed writing can be improved. While the reason for this improved input stability should not be limited to a specific theory, it is thought to be because the electrically stable contact time can be extended, and electrically unstable contact conditions can be reduced. As a result, the time of unstable input is shortened, preventing, for example, blurring of characters when writing continuously and reducing blurring during speed writing. Also, for example, in touch panels, it can solve problems such as blurring or failure to display characters on the touch panel during strokes. Therefore, it makes it possible to vividly draw characters and pictures on resistive touch panels. For example, it can even reproduce the strokes of characters as if written with a brush. A transparent conductive film possessing Feature 1 (input start load) and Feature 2 (voltage loss time) is extremely useful for applications such as resistive touch panels.

[0018] The voltage loss time is preferably 0.39 milliseconds or less, more preferably 0.35 milliseconds or less, and even more preferably 0.30 milliseconds or less, with shorter being preferable. The voltage loss time may also be 0.01 milliseconds or more, for example, 0.02 milliseconds or more. In other words, the voltage loss time is preferably 0.01 to 0.39 milliseconds, more preferably 0.01 to 0.35 milliseconds, and even more preferably 0.02 to 0.30 milliseconds.

[0019] [Test Method 2] The evaluation panel is connected to a 6V constant voltage power supply, and a pen with a hemispherical tip with a radius of 0.8 mm is used to press the center of the four-point grid of the dot spacer from the transparent conductive film side with a load of 50 gf at intervals of 5 times / second. The time from when the pen begins to lift off the transparent conductive film and the voltage decreases from 6V is measured until the voltage reaches 5V, and this time is defined as the voltage loss time. For example, Figure 5 is a conceptual diagram showing the relationship between voltage and time in one embodiment of the present invention, where the horizontal axis 13 is the time axis, the vertical axis 14 is the voltage, and the voltage loss time 15 is measured.

[0020] The transparent conductive film preferably has an ON resistance of 10kΩ or less, as determined by test method 6 (feature 3). The lower the ON resistance, the higher the pen sliding durability. The ON resistance is preferably 8kΩ or less, more preferably 5kΩ or less, even more preferably 3kΩ or less, and particularly preferably 1.0kΩ or less. The ON resistance may also be, for example, 0.1kΩ or more, 2kΩ or more, or 4kΩ or more. That is, the ON resistance is preferably 0.1 to 10kΩ, more preferably 0.1 to 8kΩ, even more preferably 0.1 to 5kΩ, even more preferably 0.1 to 3kΩ, and particularly preferably 0.1 to 1kΩ. It may also be 2 to 10kΩ, 2 to 8kΩ, 2 to 5kΩ, 2 to 3kΩ, 4 to 10kΩ, 4 to 8kΩ, or 4 to 5kΩ. [Test Method 6] An evaluation panel is created by layering a panel plate, on which a 20 nm thick indium-tin composite oxide conductive film (tin oxide content: 10 mass%) is formed on one side of a glass substrate, with a transparent conductive film, and epoxy beads with a diameter of 30 μm, so that the conductive films face each other. The transparent conductive film side of this evaluation panel is slid with a hemispherical polyacetal pen with a radius of 0.8 mm at its tip, while applying a load of 2.5 N (50,000 reciprocating cycles, sliding distance 30 mm, sliding speed 180 mm / sec). After sliding, the resistance (ON resistance) is measured when the sliding part is held down with a pen load of 0.8 N and electrically connected.

[0021] The transparent conductive film preferably has a film stiffness / softness (BR) of 0.38 N·cm or more and 0.90 N·cm or less, as determined by test method 3. By setting the film stiffness / softness (BR) to a predetermined value or higher, the input starting load can be set to a predetermined value or higher. Also, by setting the film stiffness / softness (BR) to a predetermined value or lower, the ON resistance can be set to a predetermined value or lower. Note that reducing the film stiffness / softness (BR) is also useful for reducing the input starting load. The film stiffness / softness (BR) is more preferably 0.42 N·cm or higher, and even more preferably 0.46 N·cm or higher. Furthermore, it is more preferably 0.80 N·cm or less, even more preferably 0.70 N·cm or less, and particularly preferably 0.60 N·cm or less. In other words, the film stiffness / softness (BR) is more preferably 0.42 to 0.80 N·cm, even more preferably 0.42 to 0.70 N·cm, and particularly preferably 0.46 to 0.60 N·cm.

[0022] [Test Method 3] A 20mm x 250mm transparent conductive film test specimen is placed on a horizontal table with the transparent conductive film facing upwards, and the specimen is allowed to protrude 230mm from the edge of the table. The rigidity (BR) is then determined based on the following formula. Note that the rigidity value will change if the transparent conductive film is facing downwards. Bending resistance (BR(N cm))=g×a×b×L 4 / (8×δ×10 11 ) (In the formula, g is 9.81 (gravitational acceleration; m / s²) 2where a is 20 (the length of the short side of the test piece; mm), and b is the specific gravity of the test piece (g / cm 3 ), L is 230 (the length of the long side of the test piece extending outside the horizontal platform; mm), and δ represents the difference (cm) between the height of the tip of the test piece and the height of the platform)

[0023] The transparent conductive film preferably satisfies the following formula (2-1) for the average (AVSp) of the maximum peak height Sp of the conductive surface obtained by Test Method 4. The input start load is governed by two parameters, the film stiffness (BR) and the average maximum peak height (AVSp). By setting the average maximum peak height (AVSp) to a predetermined value or more obtained from the film stiffness (BR), the input start load can be set to a predetermined value or less. Also, by setting the average maximum peak height (AVSp) to a predetermined value or less, the input start load can be set to a predetermined value or more, and in some cases, the voltage loss time can be adjusted to a more preferable range. 4.7×BR - 3.6 ≦ AVSp < 4.7×BR - 1.8... Formula (2-1) (In the formula, BR is the film stiffness (N·cm), and AVSp is the average maximum peak height (μm)) [Test Method 4] On the conductive surface of the transparent conductive film, determine a total of five measurement points, three points at 1 cm intervals in the MD direction and two points symmetrically in the TD direction at 1 cm intervals from the center. Measure the maximum peak height Sp (conforming to ISO 25178) due to the surface roughness at each location, and take the average value as the average maximum peak height (AVSp) (μm).

[0024] Regarding the relationship of the inequality sign on the left side of Formula (2-1), it is more preferable that 4.7×BR - 3.5 ≦ AVSp, and even more preferable that 4.7×BR - 3.4 ≦ AVSp. Regarding the relationship of the inequality sign on the right side of Formula (2-1), it is more preferable that AVSp < 4.7×BR - 1.9, and even more preferable that AVSp < 4.7×BR - 2.0. That is, it is more preferable that 4.7×BR - 3.5 ≦ AVSp < 4.7×BR - 1.9, and even more preferable that 4.7×BR - 3.4 ≦ AVSp < 4.7×BR - 2.0.

[0025] The transparent conductive film preferably has an average maximum peak height (AVSp) that satisfies the following formula (2-2). When the average maximum peak height (AVSp) is above a predetermined value, the transparent conductive film can be wound into a roll without any problems. The average maximum peak height (AVSp) is more preferably 0.010 (μm) or more, and even more preferably 0.020 (μm) or more. Furthermore, by setting the average maximum peak height (AVSp) to below a predetermined value, unintended electrical contact can be prevented more effectively. 0.005≦AVSp≦12.000 …Formula (2-2) (In the formula, AVSp is the average maximum peak height (μm)) In other words, AVSp is more preferably 0.010 to 12.000 μm, and even more preferably 0.020 to 12.000 μm.

[0026] The transparent conductive film preferably satisfies the following equation (2-3) when the contact area ratio (CA) determined by test method 5 is set to a predetermined value or higher. This is because a larger contact area ratio (CA) increases the stability of electrical contact between conductive layers, thus allowing for more time to be gained before the contact area becomes unstable when a pen or finger moves away from the transparent conductive film of the resistive touch panel. Furthermore, the reason why equation (2-3) increases the contact area ratio (CA) as the rigidity / softness (BR) increases is that a larger rigidity / softness (BR) increases the speed at which a pen or finger moves away from the transparent conductive film of the resistive touch panel, thus requiring the use of a transparent conductive film with a large contact area ratio (CA). CA≧32.6×BR+17.2 …Formula (2-3) (In the formula, BR is the film stiffness (N·cm) and CA is the contact area ratio (%))

[0027] [Test Method 5] The average height Rc (μm), maximum peak height Rp (μm), and average length Rsm (μm) are measured on the conductive surface of the transparent conductive film based on line roughness. The arithmetic mean height Ra (μm) based on line roughness is measured at locations that satisfy at least one of equations (X1) and (X2) and equation (X3). The average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) are determined using a 3D surface shape measuring device, BurtScan (manufactured by Ryoka Systems, R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 50x)). The determination of the maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) follows the provisions of JIS B 0601-2001. The measurement length for the arithmetic mean height Ra (μm) shall be between 100 μm and 200 μm. Rp-Rc-Ra≦0.20…Formula (X1) (Rp-Rc) / Ra≦5.0…Formula (X2) Rsm≦30…Formula (X3) The objective lens of the aforementioned 3D surface shape measuring device, BartScan, was changed to 10x magnification, and the particle analysis function in the same measuring device was used to determine the arithmetic mean height Ra(μm) - 15 × 10 from the mean plane (a 3D representation of the mean line). -3 The sample is sliced ​​in a planar direction at a height of (μm) - average height Rc(μm), and the sum of the cross-sectional areas is calculated. The contact area ratio (CA) (%) is calculated by dividing the sum of the cross-sectional areas by the area of ​​the measurement field and multiplying the result by 100.

[0028] In the aforementioned test method 5, "arithmetic mean height Ra(μm) - 15 × 10 -3 The reason for considering "(μm)" is as follows: The majority of the transparent conductive film in contact with the transparent conductive glass consists of protrusions of the average height of the transparent conductive film. Since it is difficult to accurately calculate the contact area with these average height protrusions, as an alternative index, a height slightly smaller than the average height of the aforementioned protrusions (= 15 × 10⁻¹⁰⁻¹ -3The cross-sectional area of ​​the transparent conductive film side of the transparent conductive film at a height lower than (μm) was used (note that this height is based on a point where the average height Rc (μm) is lower than the average plane). Here, if the arithmetic mean roughness Ra of JIS B 0601-2001 is used as the average height of the protrusions on the transparent conductive film, the arithmetic mean roughness Ra will be larger than the actual average height of the protrusions on the transparent conductive film due to the influence of coarse protrusions, which are few in number but very tall on the transparent conductive film side of the transparent conductive film, which is undesirable. Therefore, in order to eliminate the influence of coarse protrusions, the arithmetic mean height Ra (μm) was measured at a location that satisfies at least one of equations (X1) and (X2) and equation (X3).

[0029] The relationship between CA and BR shown in equation (2-3) is more preferably CA ≥ 32.6 × BR + 17.5, and even more preferably CA ≥ 32.6 × BR + 18.0.

[0030] The transparent conductive film is preferably such that the maximum value MXSp of the maximum peak height Sp determined by the test method 4 is greater than 1.0 and less than or equal to 1.4 times (more preferably greater than 1.0 and less than or equal to 1.40 times) the average maximum peak height AVSp. Setting the maximum value MXSp to less than or equal to a predetermined value is preferable because it makes the in-plane distribution of high protrusions in the transparent conductive film uniform, allowing touch panel input operations to be performed with the same input starting load at any location. More preferably it is 1.3 times or less, and even more preferably 1.2 times or less.

[0031] The transparent conductive film is preferably such that the minimum value MNSp of the maximum peak height Sp determined by the test method 4 is 0.6 times or more and 1.0 times or less (more preferably 0.60 times or more and 1.0 times or less) the average maximum peak height AVSp. Setting the minimum value MNSp to a predetermined value or higher is preferable because it makes the in-plane distribution of high protrusions in the transparent conductive film uniform, allowing touch panel input with the same input starting load at any location. More preferably it is 0.7 times or more, and even more preferably 0.8 times or more. Furthermore, by setting both the maximum value MXSp and the minimum value MNSp within a predetermined range, the variation in the input starting load can be reduced to less than ±5% of the average value. Moreover, it is possible to prevent variations in the input starting load between products.

[0032] The total light transmittance of the transparent conductive film is, for example, 70% to 95%, preferably 80% to 95%, and more preferably 85% to 90%.

[0033] 2. Transparent conductive film The transparent conductive film of the transparent conductive film is made of indium-tin composite oxide. The tin oxide concentration in the transparent conductive film is preferably 0.5% by mass or more and 40% by mass or less. When tin oxide is contained at 0.5% by mass or more, the surface resistance of the transparent conductive film becomes at a practical level, which is preferable. Furthermore, by setting the tin oxide concentration to 40% by mass or less, the tin oxide concentration in the transparent conductive film of the transparent conductive film can be brought closer to the tin oxide concentration in the transparent conductive glass substrate for touch panels. The closer the tin oxide concentrations of the transparent conductive film and the transparent conductive film of the glass substrate are, the easier it is for the two transparent conductive films to make electrical contact, resulting in even better appropriate input strength and input stability. The tin oxide concentration of the transparent conductive film is more preferably 25% by mass or less, even more preferably 20% by mass or less, particularly preferably 18% by mass or less, more preferably 1% by mass or more, and even more preferably 2% by mass or more. That is, the tin oxide concentration is more preferably 1 to 25% by mass, even more preferably 1 to 20% by mass, and particularly preferably 2 to 18% by mass.

[0034] The tin oxide concentration in the transparent conductive glass substrate for touch panels is generally 10% by mass. The difference between the tin oxide concentration of the transparent conductive film and the tin oxide concentration of the glass substrate is, for example, 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less.

[0035] The crystallinity of the transparent conductive film may be 0% to 100%, preferably 10% to 100%, and more preferably 50% to 100%. The higher the crystallinity, the better the pen-rubbing properties.

[0036] The surface resistance of the transparent conductive film is, for example, 50 Ω / □ to 900 Ω / □, preferably 50 Ω / □ to 700 Ω / □, and more preferably 70 Ω / □ to 500 Ω / □.

[0037] The thickness of the transparent conductive film is preferably 10 nm or more and 100 nm or less. When the thickness of the transparent conductive film is 10 nm or more, the entire transparent conductive film adheres to the transparent plastic film substrate or the curable resin layer described later, the film quality of the transparent conductive film stabilizes, and the surface resistance value tends to stabilize and fall within a desirable range. It is also effective in reducing the ON resistance determined by test method 6. More preferably, the thickness of the transparent conductive film is 13 nm or more, and even more preferably 16 nm or more. Furthermore, when the thickness of the transparent conductive film is 100 nm or less, the crystal grain size and degree of crystallinity of the transparent conductive film become appropriate, and the total light transmittance becomes at a practical level, which is preferable. More preferably, it is 50 nm or less, even more preferably 30 nm or less, and particularly preferably 25 nm or less. In other words, the thickness of the transparent conductive film is more preferably 13 to 50 nm, even more preferably 16 to 30 nm, and particularly preferably 16 to 25 nm.

[0038] In an adhesion test on the surface of the transparent conductive film in accordance with JIS K5600-5-6:1999, it is preferable that the remaining area ratio of the transparent conductive film is 95% or more, more preferably 99% or more, and particularly preferably 99.5% or more. When the remaining area ratio of the transparent conductive film in the adhesion test is within the above range, the transparent conductive film adheres tightly to the layers in contact with it, such as the transparent plastic film substrate or the curable resin layer described later. This suppresses cracking, peeling, and abrasion of the transparent conductive film even when continuously inputting with a pen on a touch panel, and furthermore, it is preferable that cracking and peeling of the transparent conductive film are suppressed even when a force stronger than that expected for normal use is applied.

[0039] The method for forming the transparent conductive film is not particularly limited, but a preferred method is to form a transparent conductive film of indium-tin composite oxide on at least one surface of a transparent plastic film substrate 7 (hereinafter referred to as the film to be treated), which may have a curable resin layer 6 formed on its surface, by sputtering. In order to manufacture the transparent conductive film with high productivity, it is preferable to use a so-called roll-type sputtering apparatus that supplies the film to be treated from a film roll and, after film formation, winds it up into the shape of a film roll.

[0040] Figure 6 is a schematic diagram of an example of a film deposition section in a roll-type sputtering apparatus. In this illustrated example, a film to be processed 1, fed from a film roll (not shown), travels while partially contacting the surface of a center roll 2. An indium-tin sputtering target 4 is placed in a chimney 3 having an opening toward the contact area between the film to be processed 1 and the center roll 2, and a thin film of indium-tin composite oxide is deposited and laminated on the surface of the film to be processed 1 as it travels on the center roll 2. The temperature of the center roll 2 can be controlled by a temperature controller (not shown).

[0041] It is preferable to use a sintered target made of indium-tin composite oxide as the target. To improve production efficiency, multiple sintered targets made of indium-tin composite oxide may be installed in the direction of film flow.

[0042] To form the film-forming atmosphere, it is preferable to flow oxygen gas, an inert gas (such as argon gas), etc., using a mass flow controller as needed. Adding oxygen gas allows for more appropriate surface resistance and total light transmittance of the transparent conductive film. The flow rate ratio (volume ratio) (oxygen gas / inert gas) of oxygen gas to inert gas is, for example, 0.005 or more, preferably 0.010 or more, more preferably 0.020 or more, and for example, 0.15 or less, preferably 0.1 or less, more preferably 0.07 or less, and even more preferably 0.05 or less. That is, the flow rate ratio (volume ratio) (oxygen gas / inert gas) of oxygen gas to inert gas is, for example, 0.005 to 0.15, preferably 0.010 to 0.1, more preferably 0.020 to 0.07, and even more preferably 0.020 to 0.05. Furthermore, a hydrogen atom-containing gas (such as hydrogen, ammonia, or a hydrogen-argon mixture; any gas containing hydrogen atoms is acceptable, except for water) may be flowed through the film deposition atmosphere, using a mass flow controller as needed.

[0043] The central value (the value midway between the maximum and minimum) of the ratio of water pressure to inert gas (water pressure / inert gas partial pressure) in a film deposition atmosphere is, for example, 7.00 × 10⁻⁶. -3 The following is preferably 5.00 × 10 -3 More preferably, 3.00 × 10 -3The following applies: The less water there is in the deposition atmosphere, the more appropriate the quality of the transparent conductive film becomes, the more likely the surface resistance value is to be at a desirable level, and the more reliable the crystallization becomes. Incidentally, while it is possible to control the amount of water based on the desired vacuum level, it is preferable to measure the amount of water (water pressure) during deposition for the following two reasons. Firstly, when a film is deposited on a plastic film by sputtering, the film is heated and water is released from the film. The effect of this released water is not reflected in the desired vacuum level. Secondly, the effect of water in the center of the roll when depositing a film wound from a film roll is not reflected in the desired vacuum level. When a film roll is held in a vacuum chamber, water easily escapes from the outer layer of the roll, but water does not easily escape from the inner layer of the roll. When the desired vacuum level is measured, the film is stopped moving, but during deposition, the film moves and the inner layer of the film roll, which contains a lot of water, is wound out, so the amount of water in the deposition atmosphere increases and becomes higher than the amount of water when the desired vacuum level is measured.

[0044] For a film roll used to form a transparent conductive film, the height difference between the most convex and most concave points at the roll end face is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 4 mm or less. If it is 10 mm or less, when the film roll is fed into the sputtering apparatus, water and organic components will not be easily released from the film end face, resulting in a better quality transparent conductive film.

[0045] It is desirable to pass the film to be treated through a bombardment process before depositing the transparent conductive film. The bombardment process involves applying a voltage and discharging a discharge while flowing only an inert gas such as argon, or a mixture of a reactive gas such as oxygen and an inert gas, to generate plasma. Specifically, it is desirable to bombard the film by RF sputtering using a SUS target or similar. Because the film is exposed to plasma during the bombardment process, water and organic components are released from the film, reducing the amount of water and organic components released from the film when the transparent conductive film is deposited, resulting in a better film quality for the transparent conductive film. In addition, the bombardment process activates the layer in contact with the transparent conductive film, improving the adhesion of the transparent conductive film and further enhancing its pen sliding durability.

[0046] It is desirable to attach a protective film with low water absorption to the side of the film to be treated 1 opposite to the side on which the transparent conductive film is formed. By attaching the protective film, gases such as water are less likely to be released from the film to be treated 1, and the film quality of the transparent conductive film is improved. Examples of the substrate for the protective film include olefins such as polyethylene, polypropylene, and cycloolefin.

[0047] During film formation, the film to be treated 1 is cooled to, for example, 0°C or below, preferably -5°C or below. Cooling the film to be treated 1 suppresses the release of impurities such as water and organic gases from the film, and ensures that the film quality of the transparent conductive film is appropriate. The film temperature during film formation can be substituted by the set temperature of the temperature controller that adjusts the temperature of the center roll in contact with the running film.

[0048] The sputtering apparatus is preferably equipped with an exhaust system such as a rotary pump, turbomolecular pump, or cryopump. The amount of moisture in the film deposition atmosphere can be controlled by the exhaust system.

[0049] It is desirable to deposit and laminate a transparent conductive film of indium-tin composite oxide onto the film to be treated, and then heat-treat it in an oxygen-containing atmosphere at a temperature of 80°C to 200°C for 0.1 hours to 12 hours. Heating above 80°C can enhance the crystallinity of the transparent conductive film, further improving pen sliding durability. Heating below 200°C ensures the flatness of the transparent plastic film.

[0050] 3. Transparent plastic film substrate The transparent plastic film substrate used in the present invention is a film obtained by melt-extruding or solution-extruding an organic polymer into a film, and then stretching, cooling, and heat-fixing it in the longitudinal and / or widthwise directions as necessary. Examples of the organic polymer include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, and polybutylene terephthalate; polyamides such as nylon 6, nylon 4, nylon 66, and nylon 12; polyimide, polyamide-imide, polyethersulfan, polyetheretherketone, polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, polyphenylene sulfide, polyphenylene oxide, polystyrene, syndiotactic polystyrene, norbornene-based polymers, and the like.

[0051] Among these organic polymers, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, syndiotactic polystyrene, norbornene-based polymers, polycarbonate, and polyarylate are preferred. Furthermore, these organic polymers may be copolymerized in small amounts with monomers of other organic polymers, or blended with other organic polymers.

[0052] A transparent plastic film substrate may be subjected to surface activation treatments such as corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, or ozone treatment, to the extent that it does not impair the objectives of the present invention.

[0053] The thickness of the transparent plastic film substrate is preferably in the range of 125 μm to 280 μm, and more preferably 150 μm to 250 μm. The thicker the transparent plastic film substrate, the easier it is for the film's rigidity (BR) to increase, and the easier it is for the average maximum peak height (AVSp) to satisfy the right-hand side of equation (2-1). Furthermore, a thickness of 125 μm or more of the transparent plastic film substrate is preferable because it maintains mechanical strength, resulting in good prevention of erroneous input, especially when used in touch panels, and also because it exhibits less deformation under pen input and has excellent pen sliding durability. On the other hand, a thickness of 280 μm or less is preferable because it maintains appropriate input strength and excellent input stability when used in touch panels.

[0054] 4.Curing resin layer The curable resin layer is formed, for example, between a transparent plastic film substrate and a transparent conductive film, and serves as the underlayer for the transparent conductive film. It is also preferable because it can block monomers and oligomers generated from the transparent plastic film substrate from precipitation on the transparent conductive film, thus not hindering the comfortable input performance of the touch panel. Furthermore, it is preferable because the transparent conductive film adheres strongly to the curable resin layer by an easy-adhesion layer, and the force applied to the transparent conductive film can be dispersed, thereby suppressing cracks, peeling, and abrasion of the transparent conductive film in pen sliding durability tests.

[0055] The resin used in the curable resin layer is not particularly limited as long as it is a resin that hardens by applying energy such as heating, ultraviolet irradiation, or electron beam irradiation, or by using a curing agent. Examples include silicone resins, acrylic resins, methacrylic resins, epoxy resins, melamine resins, polyester resins, and urethane resins. These may be used individually or in combination of two or more types. From the viewpoint of productivity, it is preferable to use an ultraviolet-curable resin as the main component.

[0056] Examples of UV-curable resins include polyfunctional acrylate resins such as polyhydric alcohols, acrylic acid or methacrylic acid esters, and polyfunctional urethane acrylate resins synthesized from diisocyanates, polyhydric alcohols, and hydroxyalkyl esters of acrylic acid or methacrylic acid. If necessary, these polyfunctional resins can be copolymerized by adding monofunctional monomers, such as vinylpyrrolidone, methyl methacrylate, or styrene.

[0057] The curable resin layer preferably contains a curing reaction initiator at least before curing. The curing reaction initiator can be selected according to the type of curing of the curable resin, and examples include thermal polymerization initiators, radical polymerization initiators such as photopolymerization initiators, and curing agents, with photopolymerization initiators being preferred. The amount of curing reaction initiator is, for example, 1 to 5 parts by mass per 100 parts by mass of the curable resin.

[0058] Any known compound that absorbs ultraviolet light and generates radicals can be used as a photopolymerization initiator without particular limitations, such as various benzoins, phenyl ketones, and benzophenones.

[0059] The curable resin layer preferably contains particles. The particles can create irregularities on the surface of the curable resin layer. Therefore, when particles are included, the contact area ratio CA generally decreases from 100%, while the control of the average maximum peak height AVSp becomes easier. Increasing the amount of particles may also decrease the stiffness BR, and it is possible to adjust the stiffness BR by changing the amount of particles. Furthermore, various properties such as pen sliding durability, anti-Newton ring properties, and film winding properties can be expressed more effectively by the particles. Note that when the amount of particles with a relatively large particle size (for example, particle A described later) is small and the amount of particles with a relatively small particle size (for example, particle B described later, used in combination with particle A) is large, the contact area ratio CA tends to be larger and the average maximum peak height AVSp tends to be larger compared to adding particles of the same particle size.

[0060] Examples of the aforementioned particles include inorganic particles and organic particles, with inorganic particles being preferred. Examples of inorganic particles include silica particles. Examples of organic particles include particles made of polyester resin, polyolefin resin, polystyrene resin, polyamide resin, etc. The particles may consist of one type or two or more types.

[0061] The number-average particle diameter of the aforementioned particles is, for example, 0.01 μm or more and 10 μm or less, preferably 0.03 μm or more and 5 μm or less, more preferably 0.05 μm or more and 3 μm or less, and particularly preferably 0.05 μm or more and 1.8 μm or less. The larger the average particle diameter, the larger the average maximum peak height AVSp of the transparent conductive layer can be. In addition to increasing the average particle diameter, the average maximum peak height can also be increased by increasing the resin concentration (solid content concentration) in the coating solution of the curable resin described later, or by reducing the thickness of the curable resin layer.

[0062] Furthermore, the standard deviation of the particle size is, for example, 20% or less of the average particle size, preferably 10% or less of the average particle size, and more preferably 5% or less of the average particle size. The smaller the standard deviation of the particle size, the larger the contact area ratio CA of the transparent conductive film can be.

[0063] In one embodiment, it is preferable to use only one type of particle B having a number-average particle diameter of 0.01 μm or more and less than 1.0 μm. In another embodiment, it is preferable to use in combination a particle A having a number-average particle diameter of 0.4 μm or more and 1.8 μm or less, which is larger than the number-average particle diameter of particle B, and a particle B having a number-average particle diameter of 0.01 μm or more and less than 1.0 μm. The average particle size of particle B is preferably 0.05 μm or more. If the average maximum peak height AVSp becomes large (for example, 0.6 μm or more), the contact area ratio CA may become too small, but by using two types of particles, A and B, the contact area ratio can be made appropriate. Note that if the average maximum peak height AVSp is greater than or equal to the right-hand side of equation (2-1) (4.7 × BR - 1.8), the contact area ratio CA will become too small even if two types of particles, A and B, are used, so it is necessary to keep the average maximum peak height AVSp below the right-hand side of equation (2-1).

[0064] When one type of particle B is included, the amount of particle B in the cured resin layer is, for example, 0.1% by mass or more and 25% by mass or less, preferably 0.5% by mass or more and 18% by mass or less, based on 100% by mass of the solid content of the cured resin layer. Furthermore, when two types of particles, A and B, are present, the amount of particle A in the curable resin layer is, for example, 0.1% to 5% by mass relative to 100% by mass of the solid content of the curable resin layer. The amount of particle B in the curable resin layer is preferably greater than the amount of particle A relative to 100% by mass of the solid content of the curable resin layer, for example, more than 5% by mass and 30% or less by mass, preferably 6% to 15% by mass.

[0065] By adjusting the particle size and quantity as described above, the average maximum peak height AVSp of the transparent conductive layer can be made to satisfy equation (2-1) while preventing the contact area ratio CV from becoming too small. The rigidity BR of the film can also be adjusted. As a result, the input starting load can be controlled within an appropriate range, the voltage loss time can be shortened, and appropriate input strength and input stability can be achieved.

[0066] The thickness of the cured resin layer is preferably in the range of 0.1 μm to 15 μm. More preferably in the range of 0.5 μm to 10 μm, and particularly preferably in the range of 1 μm to 8 μm. When the thickness of the cured resin layer is 0.1 μm or more, sufficient protrusions are formed, which is preferable. On the other hand, if it is 15 μm or less, productivity is good, which is preferable. Also, a thicker cured resin layer tends to increase the rigidity BR of the transparent conductive film.

[0067] The curable resin layer may contain a resin that is incompatible with the curable resin (hereinafter sometimes simply referred to as an incompatible resin). The dispersion of the incompatible resin within the curable resin layer can create irregularities on its surface, thereby improving surface roughness over a wide area. Examples of incompatible resins include polyester resins, polyolefin resins, polystyrene resins, and polyamide resins.

[0068] The curable resin layer is formed by liquefying the curable resin before curing and applying it to the lamination target (transparent plastic film substrate, easy-adhesive layer, etc.) and curing it. The coating may contain, in addition to the curable resin, a curing reaction initiator (such as a thermal polymerization initiator, a photopolymerization initiator, or other radical polymerization initiator, and a curing agent; preferably a photopolymerization initiator), particles, resins incompatible with the curable resin, solvents, etc. Furthermore, other known additives, such as silicone-based leveling agents, may be added to the coating liquid as needed. There are no particular restrictions on the solvent used; for example, alcohol-based solvents such as ethyl alcohol and isopropyl alcohol, ester-based solvents such as ethyl acetate and butyl acetate, ether-based solvents such as dibutyl ether and ethylene glycol monoethyl ether, ketone-based solvents such as methyl isobutyl ketone and cyclohexanone, and aromatic hydrocarbon solvents such as toluene, xylene, and solvent naphtha can be used individually or in combination.

[0069] The concentration of the curable resin in the coating solution (referred to as the solid content concentration) can be appropriately selected considering the viscosity and other factors according to the coating method. The solid content concentration is, for example, 35% by mass or more and 58% by mass or less, preferably 42% by mass or more and 55% by mass or less. When the solid content concentration is high and the thickness of the curable resin layer is thin (for example, 4.0 μm or less), the average maximum peak height of the curable resin layer tends to increase according to the relationship in equation (2-1), and the contact area ratio CA tends to decrease. However, when the solid content concentration exceeds 58% by mass (for example, when it is between 58% by mass and 65% by mass), even if the thickness of the curable resin layer is 4.0 μm or less, if particles A and particles B are used in combination, and the particle diameter of particle A is 0.80 μm or less, and the amount of particle A is 4% by mass or less relative to 100% by mass of the solid content of the curable resin layer, it becomes easier to set the average maximum peak height and the contact area ratio CA in terms of equation (2-1) within an appropriate range.

[0070] The method for coating the aforementioned coating solution onto the object to be laminated is not particularly limited, and known methods such as bar coating, gravure coating, and reverse coating can be used. In the next drying step, the solvent in the coated coating solution is evaporated and removed. If an incompatible resin (such as polyester resin) is dissolved in the coating solution, the incompatible resin precipitates as particles in the UV-curable resin during this drying step. After drying the coating film, a curable resin layer can be formed by performing an appropriate treatment (e.g., UV irradiation) according to the type of curing.

[0071] The coating surface to be laminated may be subjected to an adhesion-enhancing treatment for the curable resin layer before application of the coating solution, if necessary. Examples of adhesion-enhancing treatments include discharge treatment methods that irradiate with glow or corona discharge to increase carbonyl groups, carboxyl groups, and hydroxyl groups, and chemical treatment methods that treat with acids or alkalis to increase polar groups such as amino groups, hydroxyl groups, and carbonyl groups.

[0072] As described above, adjusting various factors is necessary to set the average maximum peak height AVSp within a predetermined range and the contact area ratio CA within a predetermined range. While the details are as described above, a general overview can be provided by utilizing the following relationship. Basically, the absolute value of the average maximum peak height AVSp tends to increase when the particle size is large, the solid content concentration is high, or the resin layer is thin. The average maximum peak height AVSp that satisfies equation (2-1) varies depending on the stiffness BP, and the smaller the stiffness BP, the smaller the average maximum peak height AVSp. Also, basically, as the average maximum peak height AVSp increases, the contact area ratio CA decreases. However, if two types of average particle sizes, large and small, are used as the average particle size added to the resin layer, and the amount of large particles added is reduced, the average maximum peak height AVSp will be high and the contact area ratio CV will be high. When using two types of particles, the less large particles added, the greater the influence of the average particle size of the small particles on the contact area ratio CA.

[0073] 5. Functional Layer The functional layer is preferably the same as the curable resin layer, except that it is formed on the opposite side of the transparent plastic film substrate. The description of the curable resin layer applies entirely to the functional layer, except for the description of particle size and quantity. Laminating the functional layer onto the transparent plastic film substrate prevents the precipitation of monomers and oligomers from the transparent plastic film substrate, thereby suppressing a decrease in the visibility of the transparent conductive film. It also allows for adjustment of the rigidity BR of the transparent conductive film. Furthermore, having a functional layer on the transparent plastic film substrate is preferable because it makes it less susceptible to scratches caused by input with a pen or other writing instrument.

[0074] When particles (particle C) are incorporated into the functional layer, the number-average particle diameter of particle C is, for example, 0.01 μm or more and 10 μm or less, preferably 0.1 μm or more and 7 μm or less, and more preferably 1 μm or more and 5 μm or less. The amount of particle C is preferably 0.1 parts by mass to 60 parts by mass, more preferably 0.3 parts by mass to 40 parts by mass, and even more preferably 0.5 parts by mass to 30 parts by mass, per 100 parts by mass of curable resin in the functional layer. The rigidity BR of the transparent conductive film can be adjusted by the amount of particle C. In addition, surface protrusions can be formed on the functional layer by particle C, and the film's windability can also be maintained.

[0075] In an adhesion test on the surface of the functional layer in accordance with JIS K5600-5-6:1999, it is preferable that the remaining area ratio of the functional layer is 95% or more, more preferably 99% or more, and particularly preferably 99.5% or more. When the remaining area ratio of the functional layer in the adhesion test is within the above range, the transparent conductive film is preferably such that the transparent plastic film substrate and the functional layer are in close contact, and even when continuous input is made with a pen on a touch panel, appearance defects such as cracks, peeling, and abrasion of the functional layer are suppressed. Furthermore, even when a force stronger than that expected for normal use is applied, cracks, peeling, etc. of the functional layer are suppressed, which is preferable.

[0076] When a transparent conductive film has a functional layer and a cured resin layer, it is preferable that the thickness of the functional layer and the cured resin layer are the same, and that the absolute value of the difference in thickness between the functional layer and the cured resin layer has the following relationship. 0.1 μm ≤ |Thickness of cured resin layer - Thickness of functional layer| ≤ 3 μm By creating a difference in thickness between the functional layer and the cured resin layer, it may be possible to adjust the rigidity BR of the transparent conductive film. Furthermore, various properties such as pen sliding durability can be expressed more effectively. In addition, the appropriate input strength can be further improved. Furthermore, it is preferable that the particle mass per unit volume of the cured resin layer and the particle mass per unit volume of the functional layer are different.

[0077] 6.Easy adhesive layer The easy-adhesion layer is preferably formed from a composition containing a urethane resin, a crosslinking agent, and a polyester resin. As the crosslinking agent, a blocked isocyanate is preferred, a trifunctional or more functional blocked isocyanate is more preferred, and a tetrafunctional or more functional blocked isocyanate is particularly preferred. The thickness of the easy-adhesion layer is preferably 0.001 μm to 2.00 μm.

[0078] This application claims the benefit of priority based on Japanese Patent Application No. 2021-103501, filed on 22 June 2021. The entire specification of Japanese Patent Application No. 2021-103501, filed on 22 June 2021, is incorporated herein by reference. [Examples]

[0079] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples. The various measurements and evaluations in the examples were performed by the methods described below.

[0080] 1. Measurement and Evaluation (1) Average particle size of silica particles The particles in the cross-section of a transparent conductive film were observed using a scanning electron microscope (KEYENCE VE-8800). Fifty particles were randomly selected, and their particle sizes were observed. Next, the observed 50 particles were divided into 0.020 μm intervals, and the total number of particles in each interval was determined. A histogram was created with the number of particles on the vertical axis and the particle size in 0.020 μm intervals on the horizontal axis. For particles whose particle size falls within ±30% of the absolute value of the center value of the particle size interval where the maximum value of the normal distribution peak in the histogram is obtained, the average number of observed particle sizes was defined as the average particle size. For example, if there are two normal distribution peaks in the histogram, it indicates that two types of particles have been added, and the average particle sizes of the two types were calculated using the same method as described above.

[0081] (2) Thickness of the curing resin layer, thickness of the functional layer The thickness of the cured resin layer was determined by observing a cross-section of the transparent conductive film with a scanning electron microscope (Keyence VE-8800), observing five arbitrary points, and using the average value as the thickness. The same method was used for determining the thickness of the functional layer.

[0082] (3) Content of tin oxide contained in the transparent conductive film Cut out the sample (approximately 15 cm) 2 The transparent conductive film was placed in a quartz Erlenmeyer flask, 20 ml of 6 mol / l hydrochloric acid was added, and the flask was sealed with a film to prevent acid evaporation. It was left at room temperature for 9 days, occasionally agitated, to dissolve the transparent conductive film. The remaining film was removed, and the hydrochloric acid in which the transparent conductive film had dissolved was used as the measurement solution. The In and Sn in the solution were determined using the calibration curve method with an ICP emission spectrometer (manufacturer: Rigaku, instrument model: CIROS-120 EOP). The measurement wavelengths for each element were selected to be interference-free and highly sensitive. In addition, commercially available In and Sn standard solutions were diluted and used as standard solutions.

[0083] (4) Transparent conductive film thickness A film sample piece with a laminated transparent conductive film was cut to a size of 1 mm × 10 mm and embedded in epoxy resin for electron microscopy. This was fixed in the sample holder of an ultramicrotome, and thin cross-sectional sections parallel to the short side of the embedded sample piece were prepared. Next, in areas of these sections where there was no significant damage to the thin film, photographs were taken using a transmission electron microscope (JEOL, JEM-2010) at an acceleration voltage of 200 kV, bright-field, and a magnification of 10,000x, and the film thickness was determined from the resulting photographs.

[0084] (5) Crystallinity of transparent conductive film A film sample with a laminated transparent conductive film was cut to a size of 1 mm x 10 mm and attached to the top surface of a suitable resin block with the conductive film side facing outwards. After trimming, ultrathin sections nearly parallel to the film surface were prepared using a general ultramicrotome technique. These sections were observed with a transmission electron microscope (JEOL, JEM-2010), and portions of the conductive thin film surface without significant damage were selected. Photographs were taken at an acceleration voltage of 200 kV and a direct magnification of 40,000x. To evaluate the crystallinity of the transparent conductive film, the proportion of crystal grains observed under the transmission electron microscope, i.e., the degree of crystallinity, was observed.

[0085] (6) Total light transmittance (%) In accordance with JIS-K7361-1:1997, the total light transmittance was measured using the NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd. (7) Surface resistance Measurements were performed using the four-terminal method in accordance with JIS-K7194:1994. The measuring instrument used was a Lotesta AX MCP-T370 manufactured by Mitsubishi Chemical Analytec Co., Ltd.

[0086] (8) Adhesion test The tests were conducted in accordance with JIS K5600-5-6:1999. The results in the table below show adhesion as a percentage of the remaining surface area. The maximum value of the remaining surface area is 100%. In the table, the closer the remaining surface area percentage in the adhesion test is to 100%, the smaller the peeled area.

[0087] (9) Rigidity (BR) (Test Method 3) A 20mm x 250mm test specimen was taken from the transparent conductive film and placed on a smooth, horizontal platform with the transparent conductive film facing upwards. Only the 20mm x 20mm portion of the test specimen was placed on the platform, with the 20mm x 230mm portion extending horizontally from the edge of the platform. A weight was placed on the 20mm x 20mm portion of the test specimen, and the weight and size of the weight were selected to ensure there was no gap between the test specimen and the platform. Next, the difference (δ) between the height of the platform and the height of the leading edge of the film was measured using a scale. The rigidity was calculated by substituting the values ​​into the following formula. Bending resistance BR (N cm)=g×a×b×L 4 / (8×δ×10 11 ) (In the formula, g is 9.81 (gravitational acceleration; m / s²) 2 ) where a is 20 (length of the shorter side of the test specimen; mm), and b is the specific gravity of the test specimen (g / cm³). 3 (This indicates that L is 230 (length of the longer side of the specimen extending outside the horizontal table; mm), and δ is the difference (cm) between the height of the specimen tip and the height of the table.) The specific gravity b mentioned above was measured using the following method. A transparent conductive film was cut into 5.0 cm squares, and the total thickness was measured at 10 different points using a micrometer to 3 significant figures. The average thickness (t: μm) was then calculated. The weight (w: g) of the 5.0 cm square sample was measured to 4 significant figures using an automatic balance, and the specific gravity was calculated using the following formula. The specific gravity was rounded to 2 significant figures. Specific gravity b(g / cm 3 ) = w / (5.0 × 5.0 × t × 10 -4 )

[0088] (10) Maximum peak height (Sp), average maximum peak height AVSp (μm) (Test method 4) The maximum surface roughness (Sp) (ISO) was measured at five points on the conductive surface of a transparent conductive film, and its arithmetic mean was defined as the average maximum surface roughness (AVSp). The five points were selected as follows: First, an arbitrary point A was chosen. Next, two points were selected, one above and one below A in the longitudinal (MD) direction of the film. Finally, two points were selected, one to the left and one to the right in the width (TD) direction of the film. The maximum surface roughness (Sp) (ISO) was determined according to ISO 25178 using a 3D surface shape measuring device, BurtScan (manufactured by Ryoka Systems, R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 10x)). Values ​​less than 1 nm were rounded.

[0089] (11) Maximum upper displacement ratio (MXSp / AVSp), Maximum lower displacement ratio (MNSp / AVSp) The ratio of the maximum value MXSp to the average value AVSp of the maximum peak height Sp obtained by the above test method 4 was defined as the upper displacement ratio of the maximum peak height (MXSp / AVSp). Furthermore, the ratio of the minimum value MNSp to the average value AVSp of the maximum peak height Sp obtained by the above-mentioned test method 4 (MNSp / AVSp) was defined as the displacement rate below the maximum peak height.

[0090] (12) Contact area ratio CA (%), average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), arithmetic mean height Ra (μm) (Test method 5) The average height Rc (μm), maximum peak height Rp (μm), and average length Rsm (μm) were measured for the conductive surface of a transparent conductive film based on line roughness. The arithmetic mean height Ra (μm) based on line roughness was measured at locations satisfying at least one of equations (X1) and (X2) and equation (X3). The average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) were determined using a 3D surface shape measuring device, BurtScan (manufactured by Ryoka Systems, R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 50x)). The determination of the maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) was carried out in accordance with the provisions of JIS B 0601-2001. The measurement length for the arithmetic mean height Ra (μm) was set to between 100 μm and 200 μm. Rp-Rc-Ra≦0.20…Formula (X1) (Rp-Rc) / Ra≦5.0…Formula (X2) The objective lens of the aforementioned 3D surface shape measuring device, BartScan, was changed to 10x magnification, and the particle analysis function in the same measuring device was used to determine the arithmetic mean height Ra(μm) from the average surface - 15 × 10 -3 The sample was sliced ​​in a planar direction at a height of (μm) - average height Rc(μm), and the sum of the cross-sectional areas was calculated. The contact area ratio (CA) (%) was calculated by dividing the sum of the cross-sectional areas by the area of ​​the measurement field of view and multiplying the result by 100.

[0091] (13) Measurement of input start load (Test method 1) As shown in Figure 6, a transparent conductive film was formed on the curable resin layer of the laminated film (film to be treated) 1 on the center roll 2 by sputtering from the target 4 inside the chimney 3. The target 4 used was either an indium-tin composite oxide sintered target or an indium oxide sintered target that does not contain tin oxide, at a rate of 3 W / cm². 2 A transparent conductive film was deposited by DC magnetron sputtering using a power density of [value missing]. The film thickness was controlled by changing the speed at which the film passed over the target. A 20 nm thick indium-tin composite oxide conductive film (tin oxide content: 10 mass%) was formed on one side of a glass substrate (size: 232 mm x 151 mm) by sputtering. Specifically, a 1.1 mm thick glass substrate (size: 232 mm x 151 mm) was placed in a vacuum chamber, and 1.5 × 10⁻¹⁰ -4 The system was evacuated to Pa. Next, oxygen was introduced, followed by argon, to bring the total pressure to 0.6 Pa. The flow rate ratio of oxygen to argon was set to 0.033. A sintered target of indium-tin composite oxide (tin oxide content: 10 mass%) was used, with a pressure of 3 W / cm². 2 Power was applied at a power density of 0.5m, and a 20nm thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) was deposited on one side of a glass substrate by DC magnetron sputtering. The glass substrate after deposition was heated in air at 230°C for 1 hour. Dot spacers (60μm x 60μm x 5μm) of epoxy resin (manufactured by Toyobo Co., Ltd., product name: CR-102C-23) were formed on the surface of the conductive film formed on one side of the glass substrate in a square grid pattern at a pitch of 4mm (ITO glass substrate). Double-sided tape (thickness: 105μm, width: 6mm) was applied to the transparent conductive film side so that a rectangle of 190mm x 135mm could be formed starting from one of the four corners of the ITO glass substrate. A transparent conductive film (size: 220mm x 135mm) obtained in the example or comparative example was attached to double-sided tape applied to an ITO glass substrate, and the conductive films were laminated so that they faced each other. At this time, one short side of the transparent conductive film was made to protrude from the ITO glass substrate (evaluation panel). The ITO glass substrate and transparent conductive film of the obtained evaluation panel were connected with a tester. A load was applied from the transparent conductive film side using a polyacetal pen (manufactured by Toray Plastics Precision Co., Ltd., product name: TPS(registered trademark) POM(NC), tip shape: 0.8mmR), and the load value at which the resistance measured by the tester stabilized was used as the input starting load. The position 12 where the pen applied load was the central area of ​​the four dot spacers 11 arranged in a grid pattern on the ITO glass substrate 10, as shown in the enlarged section of Figure 7. The input starting load was measured at three arbitrary points at least 50 mm away from the double-sided tape, and the average value was taken. The value was rounded to the first decimal place. Furthermore, another evaluation panel was prepared using the same method as described above, and the input starting load was determined. When the two input starting loads were rounded to the first decimal place, if they matched, the input starting load was evaluated as stable, and one value is shown in Table 6. On the other hand, if the two input starting loads did not match, two results are shown in Table 6.

[0092] (14) Measurement of voltage loss time (Test method 2) A constant voltage power supply is connected to the evaluation panel created using the input start load measurement. Next, a recorder (Keyence GR-7000) capable of measuring the voltage between the ITO glass substrate and the transparent conductive film is connected. Here, the recorder is used to observe the time change of the voltage. Next, 6V is applied to the constant voltage power supply, and the recorder starts measuring the voltage in 0.02 millisecond increments. Next, a load of 50g is applied from the transparent conductive film side using a polyacetal pen (Toray Plastics Precision Co., Ltd., product name: TPS(registered trademark) POM(NC), tip shape: 0.8mmR) at a rate of 5 times per second. The position where the load is applied with the pen is near the center of the evaluation panel, in the central area of ​​the four dot spacers arranged in a grid. The time change data of the voltage when the load is applied to the transparent conductive film with the pen is retrieved from the recorder. Starting from the point when the pen begins to move away from the transparent conductive film and the voltage decreases from 6V, the time until the voltage reaches 5V is measured and recorded as the voltage loss time (see Figure 5).

[0093] (15) Appropriate input strength test (prevention of input errors, comfortable input) Resistive touch panels were fabricated using the transparent conductive films obtained in the examples and comparative examples. Input strength was investigated using a polyacetal pen (manufactured by Toray Plastics Precision Co., Ltd., product name: TPS(registered trademark) POM(NC), tip shape: 0.8mmR). (Prevention of input errors) ○...Insufficient input when touching the touchscreen while unsure of what to do. ×...Increased input occurs when touching the touchscreen while unsure of what to do. (Comfortable input) ○...It can be entered without consciously applying strong force. △...The behavior is unstable. ×...In some cases, you may not be able to input unless you consciously apply strong force.

[0094] (16) Input stability (stability of strokes, speed of writing) A resistive touch panel was fabricated using the transparent conductive films obtained in the examples and comparative examples. Input stability was investigated using a polyacetal pen. (Payment stability) ○...When typing characters, the strokes are less likely to become blurred. ×...When typing characters, the strokes tend to become blurry. (shorthand) ○...When entering characters continuously, the characters are less likely to become blurred or smudged. ×...When entering characters continuously, the characters are prone to blurring or smudging.

[0095] (17) Pen sliding durability (Test method 6) A transparent conductive film was used as one panel plate, and for the other panel plate, a 20 nm thick indium-tin composite oxide thin film (tin oxide content: 10 mass%) was formed on one side of a glass substrate by sputtering. Specifically, in the manufacturing of the other panel plate, a 1.1 mm thick glass substrate (size: 5 cm × 6 cm) was placed in a vacuum chamber, and 1.5 × 10 -4 The system was evacuated to Pa. Next, oxygen was introduced, followed by argon, to bring the total pressure to 0.6 Pa. The flow rate ratio of oxygen to argon was set to 0.033. A sintered target of indium-tin composite oxide (tin oxide content: 10 mass%) was used, with a pressure of 3 W / cm². 2Power was applied at a power density of 0.5°C, and an indium-tin composite oxide conductive film with a thickness of 20 nm (tin oxide content: 10% by mass) was deposited on one side of a glass substrate by DC magnetron sputtering. The glass substrate after deposition was heated in air at 230°C for 1 hour. On the surface of the conductive film formed on one side of the glass substrate, epoxy resin beads (manufactured by Toyobo Co., Ltd., product name: CR-102C-23) (diameter 30 μm) were formed in a square lattice pattern at a pitch of 4 mm, as shown in Figure 8 (ITO glass substrate). The transparent conductive film (size: 5 cm × 6 cm) obtained in the example or comparative example and the ITO glass substrate were stacked so that the transparent conductive films faced each other. When stacking, as shown in Figure 9, the transparent conductive film 20 and the ITO glass substrate 10 were aligned so that their longitudinal directions were perpendicular to each other, with their respective ends 16 aligned, and one longitudinal end 18 of the transparent conductive film 20 and one longitudinal end 17 of the ITO glass substrate 10 protruding from the overlapping surface 19, and the protruding parts 17 and 18 were connected to the tester, respectively. Next, a load of 2.5N was applied to a polyacetal pen (manufactured by Toray Plastics Precision Co., Ltd., product name: TPS(registered trademark) POM(NC), tip shape: 0.8mmR), and a linear sliding test of 50,000 reciprocations was performed on the touch panel. The sliding distance at this time was 30 mm, and the sliding speed was 180 mm / second. The sliding position 21 was between the dot spacers 11 arranged in a grid pattern on the surface of the ITO glass substrate 10, as shown in the partially enlarged view of Figure 8. After this sliding durability test, the ON resistance (the resistance value when the movable electrode (film electrode) and the fixed electrode are in contact) was measured when the sliding part was pressed with a pen load of 0.8N. An ON resistance of 10kΩ or less is more desirable.

[0096] 2. Laminated film In the Examples section, a laminated film consisting of the following transparent plastic film substrate, curable resin layer, and functional layer was used. (1) Substrate (transparent plastic film substrate): Biaxially oriented transparent PET film with easy-adhesion layers on both sides (manufactured by Toyobo Co., Ltd., A4380, thickness is shown in Table 1).

[0097] (2) Curable resin layer: 100 parts by mass (solids) of acrylic resin containing a photopolymerization initiator (manufactured by Dainichi Seika Kogyo Co., Ltd., Seika Beam® EXF-01J) was mixed with silica particles (particles A and B) with the number-average particle size listed in Table 1 in the amounts listed in Table 1. Note that the amount of particles added listed in Table 1 is the amount relative to 100% by mass of the solids content of the resin. A mixed solvent of toluene / methyl ethyl ketone (MEK) (8 / 2: mass ratio) was added to the solids content to the value shown in Table 1, and the mixture was stirred to uniformly disperse and prepare a coating solution (coating solution A). Coating solution A, which was prepared so that the thickness of the coating film was the value shown in Table 1, was applied to one side of a transparent plastic film substrate using a Meyer bar. After drying at 80°C for 1 minute, ultraviolet light was irradiated using an ultraviolet irradiation device (manufactured by I-Graphics Co., Ltd., UB042-5AM-W type) (light intensity: 300 mJ / cm²). 2 The coating was then cured.

[0098] (3) Functional layer: 100 parts by mass (solids) of acrylic resin containing a photopolymerization initiator (manufactured by Dainichi Seika Kogyo Co., Ltd., Seika Beam® EXF-01J) was mixed with silica particles (particle C) with the number-average particle size listed in Table 2 in the amount listed in Table 2. Note that the amount of particles added listed in Table 2 is the amount relative to 100% by mass of the solids content of the resin. A mixed solvent of toluene / MEK (8 / 2: mass ratio) was added as a solvent to the solids content value shown in Table 2, and the mixture was stirred to uniformly disperse and prepare a coating solution (coating solution C). Coating solution C, which was prepared to have a coating thickness of the value shown in Table 2, was applied to the side of the transparent plastic film substrate opposite to the curable resin layer using a Meyer bar. After drying at 80°C for 1 minute, ultraviolet light was irradiated using an ultraviolet irradiation device (manufactured by I-Graphics Co., Ltd., UB042-5AM-W type) (light intensity: 300 mJ / cm²). 2 The coating was then cured.

[0099] Examples 1-8 The laminated film is placed in the vacuum chamber, 1.5 × 10 -4 The system was evacuated to Pa. Next, oxygen was introduced, followed by argon, to bring the total pressure to 0.6 Pa. The flow rate ratio of oxygen to argon is shown in Table 3. As shown in Figure 6, a transparent conductive film was formed on the curable resin layer of the laminated film (film to be treated) 1 on the center roll 2 by sputtering from the target 4 inside the chimney 3. The target 4 used was either an indium-tin composite oxide sintered target or an indium oxide sintered target that does not contain tin oxide, at a rate of 3 W / cm². 2 A transparent conductive film was deposited by DC magnetron sputtering using a power density of [value missing]. The film thickness was controlled by changing the speed at which the film passed over the target. Furthermore, the ratio of water content to argon in the film deposition atmosphere during sputtering was measured using a gas analyzer (Inficon, Transspector XPR3) and is shown in Table 3. As shown in Table 3, this water content ratio was adjusted by the presence or absence of a bombardment process, the presence or absence of a protective film, the difference in the unevenness of the film roll end face, and the temperature of the heating medium in the temperature controller that controls the temperature of the center roll in which the film is in contact. In the bombardment process, SUS (stainless steel) was used as the target and the pressure was 0.5 W / cm². 2 RF sputtering was performed. The amount of gas introduced for RF sputtering was the same as the amount of gas described in the example introduced into the vacuum apparatus. When using a protective film, a polyethylene film with a thickness of 65 μm was used. An acrylic adhesive was applied to one side of the protective film. The protective film was attached to the side of the laminated film opposite to the side on which the transparent conductive film was formed. The temperature of the heating medium was set to the value shown in Table 3, which is the temperature exactly in the middle of the maximum and minimum temperatures from the start to the end of film formation on the film roll. A transparent conductive film was obtained by subjecting a film laminated with a transparent conductive film to the heat treatment shown in Table 3. The obtained transparent conductive films were evaluated for their thickness, crystallinity, total light transmittance (%), surface resistance (Ω / □), adhesion to the transparent conductive film, and adhesion to the functional layer. The results are shown in Table 4.

[0100] For the obtained transparent conductive film, the rigidity (BR), average maximum peak height (AVSp), contact area ratio (CA), upper maximum peak height displacement ratio (MXSp / AVSp), and lower maximum peak height displacement ratio (MNSp / AVSp) were determined. The results are shown in Table 5.

[0101] The obtained transparent conductive film was subjected to the following tests: input start load, voltage loss time, appropriate input strength test (prevention of incorrect input, comfortable input), input stability (stroke stability, speed writing), and pen sliding durability. The results are shown in Table 6.

[0102] Comparative Examples 1-8 A transparent conductive film was prepared in the same manner as in Examples 1 to 8, except that a laminated film prepared under the conditions shown in Tables 1 and 2 was used to form a transparent conductive film under the conditions shown in Table 3. The properties of the obtained film are shown in Tables 4 to 6.

[0103] [Table 1]

[0104] [Table 2]

[0105] [Table 3]

[0106] [Table 4]

[0107] [Table 5]

[0108] [Table 6] [Industrial applicability]

[0109] Transparent conductive films can be widely used in electrical and electronic applications, such as in flat panel displays like liquid crystal displays and electroluminescent (EL) displays, and as transparent electrodes for touch panels. [Explanation of symbols]

[0110] 1. Film to be treated 2 Center Roll 3 Chimney 4 Targets 5 Transparent conductive film 6 Curing resin layer 7. Transparent plastic film substrate 8 Functional Layers 9 Easy adhesive layer 10 ITO glass substrates 11 Dot Spacers 12. Position where the pen applies pressure. 13 hours 14 Voltage 15. Voltage loss time 16 ends 17, 18 Overhang 19 Overlapping surfaces 20 Transparent conductive film 21 Sliding position

Claims

1. A transparent conductive film comprising a transparent conductive film of indium-tin composite oxide laminated on at least one surface of a transparent plastic film substrate, and a curable resin layer containing at least particles B with a number average particle diameter of 0.01 μm or more and less than 1.0 μm, between the transparent plastic film substrate and the transparent conductive film, The film stiffness (BR) determined by test method 3 is 0.38 N·cm or more and 0.90 N·cm or less. The average of the maximum peak height Sp of the conductive surface determined by test method 4 (AVSp) satisfies the following equations (2-1) and (2-2), A transparent conductive film whose contact area ratio (CA) determined by test method 5 satisfies the following formula (2-3). 4.7 × BR - 3.6 ≤ AVSp < 4.7 × BR - 1.8 ...Formula (2-1) 0.005≦AVSp≦12.000...Formula (2-2) CA≧32.6×BR+17.2…Formula (2-3) (In the formula, BR is the film stiffness (N·cm), AVSp is the average maximum peak height (μm), and CA is the contact area ratio (%).) [Test Method 3] A 20 mm x 250 mm transparent conductive film test specimen is placed on a horizontal table with the transparent conductive film facing upwards, and the specimen is allowed to protrude 230 mm from the edge of the table. The rigidity / softness (BR) is then determined based on the following formula. Bending resistance (BR (N cm)) =g×a×b×L 4 / (8×δ×10 11 ) (In the formula, g is 9.81 (gravitational acceleration; m / s²) 2 ) where a is 20 (length of the short side of the test piece; mm), and b is the specific gravity of the test piece (g / cm³). 3 (This indicates that L is 230 (length of the longer side of the specimen extending outside the horizontal table; mm), and δ is the difference (cm) between the height of the specimen tip and the height of the table.) [Test Method 4] On the conductive surface of the transparent conductive film, five measurement points are determined: three points in the MD direction at 1 cm intervals, and two points symmetrically in the TD direction at 1 cm intervals from the center. At each point, the maximum peak height Sp (according to ISO 25178) due to surface roughness is measured, and the average value is defined as the average maximum peak height (AVSp) (μm). [Test Method 5] The average height Rc (μm), maximum peak height Rp (μm), and average length Rsm (μm) are measured for the conductive surface of the transparent conductive film based on line roughness. The arithmetic mean height Ra (μm) based on line roughness is measured at locations that satisfy at least one of equations (X1) and (X2) and equation (X3). The average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) are determined using a three-dimensional surface shape measuring device, BurtScan (manufactured by Ryoka Systems, R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 50x)). The determination of the maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) follows the provisions of JIS B 0601-2001. The measurement length for the arithmetic mean height Ra (μm) shall be between 100 μm and 200 μm. Rp - Rc - Ra ≤ 0.20 …Equation (X1) (Rp-Rc) / Ra≦5.0...Formula (X2) Rsm≦30...Formula (X3) The objective lens of the aforementioned three-dimensional surface shape measuring device, BartScan, was changed to 10x magnification, and the particle analysis function in the same measuring device was used to determine the arithmetic mean height Ra (μm) from the average surface - 15 × 10 -3 The material is sliced ​​in a planar direction at a height equal to (μm) - average height Rc (μm), and the sum of the cross-sectional areas is calculated. The contact area ratio (CA) (%) is calculated by dividing the sum of the cross-sectional areas by the area of ​​the measurement field of view and multiplying the result by 100.

2. The maximum value MXSp of the maximum peak height Sp determined by the above test method 4 is greater than 1.0 times and less than or equal to 1.4 times the average maximum peak height AVSp, and The transparent conductive film according to claim 1, wherein the minimum value MNSp of the maximum peak height Sp determined by the test method 4 is 0.6 times or more and 1.0 times or less of the average maximum peak height AVSp.

3. The transparent conductive film according to claim 1, wherein the thickness of the transparent conductive film is 10 nm or more and 100 nm or less.

4. The transparent conductive film according to any one of claims 1 to 3, wherein the concentration of tin oxide contained in the transparent conductive film is 0.5% by mass or more and 40% by mass or less.

5. A transparent conductive film according to any one of claims 1 to 3, having a functional layer on the side of the transparent conductive film of the transparent plastic film substrate.

6. The transparent conductive film according to claim 5, wherein the functional layer comprises a curable resin layer containing particles C having a number average particle diameter of 0.01 to 10 μm.

7. A transparent conductive film according to any one of claims 1 to 3, having an easy-adhesion layer on at least one side of a transparent plastic film substrate.

8. A transparent plastic film substrate has an easy-adhesion layer on at least one side. The transparent conductive film according to claim 5, wherein the easy-adhesion layer is disposed at least one of the positions between the transparent plastic film substrate and the curable resin layer, or between the transparent plastic film substrate and the functional layer.

9. A transparent conductive film according to any one of claims 1 to 3, wherein the ON resistance determined by test method 6 is 10 kΩ or less. [Test Method 6] An evaluation panel is created by layering a panel plate, on which a 20 nm thick indium-tin composite oxide conductive film (tin oxide content: 10 mass%) is formed on one side of a glass substrate, with a transparent conductive film, and epoxy beads with a diameter of 30 μm, so that the conductive films face each other. The transparent conductive film side of this evaluation panel is slid with a pen made of polyacetal with a hemispherical tip of radius 0.8 mm while applying a load of 2.5 N (50,000 reciprocating cycles, sliding distance 30 mm, sliding speed 180 mm / second). After sliding, the resistance (ON resistance) is measured when the sliding part is held down with a pen load of 0.8 N and electrically connected.

10. A transparent conductive film according to any one of claims 1 to 3, wherein, in an adhesion test on the surface of the transparent conductive film in accordance with JIS K5600-5-6:1999, the remaining area ratio of the transparent conductive film is 95% or more.

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