WO2023157563A1 - Transparent conductive film - Google Patents

Abstract

Provided is a transparent conductive film having excellent lightsome input, input stability, and clarity.　The transparent conductive film, in which a transparent conductive film of an indium-tin composite oxide is laminated on at least one surface of a transparent plastic film substrate, has: an input starting load of 3-15 g; a voltage loss time of 0.00-0.40 milliseconds; and a total sum of five types of transmission image clarity of 400-500%, as measured using each of five types of optical combs which have a 0.125 mm width, 0.25 mm width, 0.5 mm width, 1 mm width, and 2 mm width, respectively.

Description

transparent conductive film

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.

Transparent conductive films, which are made by laminating a transparent and low-resistance thin film on a transparent plastic substrate, are used in applications that make use of their conductivity, such as flat panel displays such as liquid crystal displays and electroluminescence (EL) displays. It is widely used in the electrical and electronic fields as a transparent electrode for touch panels, etc.

A resistive touch panel is a combination of a fixed electrode made by coating a transparent conductive thin film on a glass or plastic substrate and a movable electrode (called a film electrode) made by coating a transparent conductive thin film on a plastic film. It is used superimposed on the upper side of the display body. When the film electrode is pressed with a finger or pen (referred to as input), the fixed electrode and the transparent conductive thin film of the film electrode come into contact with each other, and the input position is recognized.

Patent Document 1 discloses a transparent conductive laminate for a touch panel, in which a transparent conductive film mainly composed of substantially crystalline indium oxide is laminated on at least one surface of a polymer film. Writing durability is improved by crystallizing indium oxide.

Japanese Patent Application Laid-Open No. 2004-071171

A touch panel is required to have characteristics (pen sliding durability) that do not cause cracks, peeling, or abrasion of the transparent conductive film even when continuous input is made with a pen.
In addition, the touch panel is required to be light and easy to input. The nimble input means that input can be made even by lightly touching the resistive touch panel with a pen, finger, or the like.

Further, the touch panel is required to have excellent input stability, that is, the input to the touch panel must be stable from the time the touch panel is touched with a pen or the like until the touch panel is removed. For example, it is required to be able to reduce blurring of characters that may occur when characters are input continuously (stenography stability), and to be excellent in not blurring the stroked portion of characters (stroke stability). Moreover, the clearness of a touch panel is desired. If the touch panel has high clarity, there are advantages such as being able to see images clearly, and being able to see the touch panel clearly in black when the display is turned off, creating a sense of luxury.
In the technique of Patent Document 1, pen sliding durability could not be improved when indium oxide was not crystallized. In addition, conventional transparent conductive films, including those disclosed in Patent Document 1, are not sufficient in light input performance, input stability (stenography stability, wiping stability), clearness, and the like.

Accordingly, an object of the present invention is to provide a transparent conductive film that is excellent in light input performance, input stability, and clearness. A preferred object of the present invention is to provide a transparent conductive film which also has pen sliding durability. A preferred object of the present invention also includes an erroneous reaction prevention property.

The present invention has been made in view of the above circumstances, and the transparent conductive film of the present invention, which has solved 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 start load determined by test method 1 is 3 g or more and 15 g or less,
The voltage loss time determined by test method 2 is 0.00 ms or more and 0.40 ms or less,
Each of the five types of transmission measured in accordance with JIS K7374 with an image clarity measuring instrument using five types of optical combs of 0.125 mm width, 0.25 mm width, 0.5 mm width, 1 mm width, or 2 mm width. A transparent conductive film having a total image definition of 400 to 500%.
[Test method 1]
A 20 nm-thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) was formed on one side of a glass substrate, and dot spacers (length 60 µm x width 60 µm x height 5 µm) were formed on the surface of the thin film. A panel plate is formed by forming a square lattice with a pitch of 4 mm. On the conductive film side of this panel plate, while sandwiching an adhesive rectangular frame having a thickness of 105 μm and an inner circumference of 190 mm×135 mm, transparent conductive films were laminated so that the conductive films face each other to prepare an evaluation panel. do. From the transparent conductive film side of this evaluation panel, the center of the four-point lattice of the dot spacer is pressed with a pen made of hemispherical polyacetal with a tip radius of 0.8 mm, and the pressure when the resistance value starts to stabilize is measured. Input starting load.
[Test method 2]
The evaluation panel is connected to a 6 V constant voltage power supply, and a pen whose tip is a hemisphere with a radius of 0.8 mm is used to apply a load of 50 gf to the center of the four-point lattice of the dot spacer from the transparent conductive film side 5 times / second. Press at intervals of . Starting when the pen begins to separate from the transparent conductive film and the voltage decreases from 6 V, the time until the voltage reaches 5 V is measured and defined as the voltage loss time.
[2]
The film bending resistance (BR) determined by test method 3 is 0.23 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 formulas (2-1) and (2-2),
The contact area ratio (CA) determined by test method 5 satisfies the following formula (2-3),
The transparent conductive film according to [1], having an arithmetic mean height Sa (according to ISO 25178) of 1 to 55 nm.
AVSp≧4.7×BR−1.8 Formula (2-1)
0.005≦AVSp≦12.000 Expression (2-2)
CA≧32.6×BR+17.2 Expression (2-3)
(Wherein, BR is the film bending resistance (N cm), AVSp is the average maximum peak height (μm), and CA is the contact area ratio (%))
[Test method 3]
A 20 mm × 250 mm transparent conductive film test piece is placed on a horizontal table with the transparent conductive film facing up, the test piece is protruded from the end of the table with a length of 230 mm, and the bending resistance (BR ).
Bending resistance (BR (N cm)) = g x a x b x L ⁴ / (8 x δ x 10 ¹¹ )
(In the formula, a is 9.81 (gravitational acceleration; m/s ² ), b is the specific gravity (g/cm ³ ) of the test piece, and L is 230 (the weight of the test piece outside the horizontal table. The length of the long side; mm), and δ indicates the difference (cm) between the height of the tip of the test piece and the height of the table)
[Test method 4]
On the conductive surface of the transparent conductive film, 3 points at 1 cm intervals in the MD direction and 2 points symmetrically in the TD direction from the center are determined, a total of 5 measurement points, and the maximum peak height Sp due to surface roughness at each point (according to ISO 25178), and the average value is defined as the average maximum peak height (AVSp) (μm).
[Test method 5]
The average height Rc (μm), the maximum peak height Rp (μm), and the average length Rsm (μm) are measured according to the line roughness of the conductive surface of the transparent conductive film, and the formulas (X1) and (X2) are obtained. The arithmetic mean height Ra (μm) based on the line roughness is measured at a place satisfying at least one of and formula (X3). Note that the average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) were measured , R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 50x)). Maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) are determined according to JIS B 0601-2001. The measurement length of the arithmetic mean height Ra (μm) is 100 μm or more and 200 μm or less.
Rp−Rc−Ra≦0.20 Formula (X1)
(Rp−Rc)/Ra≦5.0 Formula (X2)
Rsm≦30 Expression (X3)
The objective lens of the three-dimensional surface profile measurement device Vertscan was changed to 10 times, and the particle analysis in the same measurement device was used to determine the "arithmetic mean height Ra (μm) -15 × 10 ^-3 (μm) from the average surface. -Average height Rc (μm)” is used as a threshold value to slice in the plane direction, and the sum of cross-sectional areas is obtained. The contact area ratio (CA) (%) is obtained by multiplying the value obtained by dividing the sum of the cross-sectional areas by the area of the measurement visual field and multiplying by 100.
[3]
The maximum value MXSp of the maximum peak height Sp determined by the test method 4 is more than 1.0 times and 1.4 times or less than 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 Test Method 4 is 0.6 to 1.0 times the average maximum peak height AVSp.
[4]
The transparent conductive film according to any one of [1] to [3], wherein the transparent conductive film has a thickness of 10 nm or more and 100 nm or less.
[5]
The 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]
Having a curable resin layer between the transparent conductive film and the transparent plastic film substrate,
The transparent conductive film according to any one of [1] to [5], further comprising a functional layer on the opposite side of the transparent plastic substrate to the transparent conductive film.
[7]
The transparent conductive film according to any one of [1] to [6], which has an easy-adhesion layer on at least one side of the transparent plastic film substrate.
[8]
The transparent conductive film according to [7], wherein the easy-adhesion layer is disposed at least either between the transparent plastic film substrate and the curable resin layer or between the transparent plastic substrate and the functional layer. .
[9]
The transparent conductive film according to any one of [1] to [8], which has an ON resistance of 10 kΩ or less as determined by Test Method 6.
[Test method 6]
A panel plate having a 20 nm-thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) formed on one side of a glass substrate and a transparent conductive film are stacked so that the conductive films face each other. to create an evaluation panel. The transparent conductive film side of this evaluation panel is slid while applying a load of 2.5 N with a pen having a hemispherical polyacetal tip with a radius of 0.8 mm (50,000 reciprocations, sliding distance 30 mm, sliding speed 180 mm/sec). After sliding, the center of the sliding portion is pressed with a pen load of 0.8 N to measure the resistance (ON resistance) when electrically connected.
[10]
According to any one of [1] to [9], the remaining area ratio of the transparent conductive film is 95% or more in an adhesion test according to JIS K5600-5-6:1999 on the surface of the transparent conductive film. Transparent conductive film.

According to the present invention, it is possible to provide a transparent conductive film that is excellent in light input performance, input stability, and clearness. In addition, according to the present invention, it is possible to provide a transparent conductive film having pen sliding durability, erroneous reaction prevention, etc., if desired.

FIG. 1 is a schematic side view showing an example of the transparent conductive film of the present invention. FIG. 2 is a schematic side view showing another example of the transparent conductive film of the present invention. FIG. 3 is a schematic side view showing still another example of the transparent conductive film of the present invention. FIG. 4 is a schematic side view showing another example of the transparent conductive film of the present invention. FIG. 5 is a conceptual diagram showing the relationship between voltage and time in one embodiment of the present invention. FIG. 6 is a schematic diagram of an apparatus showing an example of the film forming method of the present invention. FIG. 7 is a schematic plan view for explaining the input start load measuring method according to the present invention.

1. Transparent Conductive Film The transparent conductive film of the present invention is obtained by laminating a transparent conductive film of indium-tin composite oxide on at least one surface of a transparent plastic film substrate. By having a transparent conductive film on the surface, applications that utilize its conductivity, such as flat panel displays such as liquid crystal displays and electroluminescence (EL) displays, transparent electrodes for touch panels, etc., are used in the electric and electronic fields. It can be used for a wide range of purposes. A specific layer structure of the transparent conductive film can be appropriately set, and examples thereof include the structures shown in schematic side views of FIGS. 1, 2, 3, and 4.

In the transparent conductive film of FIG. 1, a transparent conductive film 5 is formed on one side of a transparent plastic film substrate 7 via a curable resin layer 6, and a functional layer 8 is formed on the opposite side of the transparent plastic film substrate 7. ing. By forming the curable resin layer 6 between the transparent conductive film 5 and the transparent plastic film substrate 7 , it is possible to block the precipitation of monomers and oligomers from the transparent plastic film substrate 7 onto the transparent conductive film 5 . The transparent conductive film of the present invention can improve the input intensity characteristics (such as prevention of false reactions, quick input, etc.), input stability and clearness by controlling the input start load, voltage loss time, and transmission image definition, which will be described later. Oligomer precipitation blocks further improve input strength characteristics (misreaction prevention, light input, etc.), input stability, and clearness. Further, by preventing deposition of monomers and oligomers by the curable resin layer 6 and the functional layer 8, the transparency (clearness) and visibility of the transparent conductive film can be further enhanced. Further, by including the curable resin layer 6 and/or the functional layer 8, the bending resistance of the transparent conductive film, which will be described later, can be adjusted. The curable resin layer 6 and/or the functional layer 8 may not necessarily be required depending on the rigidity of the transparent plastic film substrate.

In one aspect, the transparent conductive film of the present invention has an easily adhesive layer laminated on at least one side of a transparent plastic film substrate. For example, as shown in FIG. 2, the curable resin layer 6 and the transparent plastic film substrate 7 may be adhered with an easy-adhesive layer 9 . As shown in FIG. 3 , the functional layer 8 and the transparent plastic film substrate 7 may be adhered with an easy-adhesive layer 9 . As shown in FIG. 4 , each of the curable resin layer 6 and the functional layer 8 and the transparent plastic film substrate 7 may be adhered to each other with an easy-adhesive layer 9 . The easy-adhesive layer 9 can more effectively prevent the curable resin layer 6 and/or the functional layer 8 from peeling off from the transparent plastic film substrate 7 due to an external force.

The transparent conductive film of the present invention is characterized (characteristic 1) in that the input starting load determined by test method 1 is 3 g or more and 15 g or less. By setting the input start load to a predetermined value or less, it is possible to improve the nimble input performance. By setting the input start load to a predetermined value or more, it is possible to improve the prevention of erroneous reactions of the touch panel.
The input start load may be 4 g or more, 5 g or more, or 6 g or more, and may be 14 g or less, 13 g or less, or 12 g or less.

[Test method 1]
A 20 nm-thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) was formed on one side of a glass substrate, and dot spacers (length 60 µm x width 60 µm x height 5 µm) were formed on the surface of the thin film. A panel plate is formed by forming a square lattice with a pitch of 4 mm. On the conductive film side of this panel plate, while sandwiching an adhesive rectangular frame having a thickness of 105 μm and an inner circumference of 190 mm×135 mm, transparent conductive films were laminated so that the conductive films face each other to prepare an evaluation panel. do. From the transparent conductive film side of this evaluation panel, the center of the four-point lattice of the dot spacer is pressed with a pen made of hemispherical polyacetal with a tip radius of 0.8 mm, and the pressure when the resistance value starts to stabilize is measured. Input starting load. Here, "stable resistance value" means a state in which the resistance value fluctuates within a range of ±5%.

The transparent conductive film also has a feature (feature 2) in that the voltage loss time determined by test method 2 is 0.00 ms or more and 0.40 ms or less. By keeping the voltage loss time within the predetermined range, the electrically stable contact time can be made longer. By setting the input start load to a predetermined value or less, it is possible to improve the light input performance, and by setting the voltage loss time to a predetermined range, it is possible to improve the input stability such as wiping stability and stenography stability. . The reason why such an input stability effect is produced should not be interpreted as being limited to a specific theory, but the electrically stable contact time can be extended and the electrically unstable contact state can be further reduced. This is probably because it is possible. As a result, the time during which the input is unstable can be shortened, and for example, blurring of characters can be prevented when characters are written continuously, and blurring of characters during stenography can be reduced. Also, for example, in a touch panel, it is possible to solve the problem that the characters displayed on the touch panel are faint or not displayed when character payment is performed. Therefore, it is possible to vividly draw characters and pictures that you want to express on the resistive touch panel. For example, it is possible to express the scribbles of characters that are expressed with a brush.

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, and the shorter the better. Also, the voltage loss time may be 0.01 milliseconds or longer, for example, 0.02 milliseconds or longer.

[Test method 2]
The evaluation panel is connected to a 6 V constant voltage power supply, and a pen whose tip is a hemisphere with a radius of 0.8 mm is used to apply a load of 50 gf to the center of the four-point lattice of the dot spacer from the transparent conductive film side 5 times / second. Press at intervals of . Starting when the pen begins to separate from the transparent conductive film and the voltage decreases from 6 V, the time until the voltage reaches 5 V is measured and defined as the voltage loss time. For example, FIG. 5 is a conceptual diagram showing the relationship between voltage and time in one aspect of the present invention, in which the horizontal axis 13 is the time axis and the vertical axis 14 is the voltage, and the voltage loss time 15 is measured. .

In addition, the transparent conductive film was measured according to JIS K7374 with an image clarity measuring instrument using five types of optical combs of 0.125 mm width, 0.25 mm width, 0.5 mm width, 1 mm width, or 2 mm width. There is also a feature (feature 4) in that the sum of the measured five types of transmitted image definition is 400 to 500%. The clearness of the touch panel is excellent because the sum of the transmitted image clarity is within the predetermined range. The sum of transmission image definition is preferably 430 to 500%, more preferably 450 to 500%, still more preferably 460 to 500%, the higher the better.

The transparent conductive film preferably has an ON resistance of 10 kΩ or less as determined by test method 6 (feature 3). Pen sliding durability can be improved, so that ON resistance is small. The ON resistance is preferably 8 kΩ or less, more preferably 5 kΩ or less, still more preferably 3 kΩ or less, and particularly preferably 1.0 kΩ or less. The ON resistance may be, for example, 0.1 kΩ or more, 2 kΩ or more, or 4 kΩ or more.
[Test method 6]
A panel plate having a 20 nm-thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) formed on one side of a glass substrate and a transparent conductive film are stacked so that the conductive films face each other. to create an evaluation panel. The transparent conductive film side of this evaluation panel is slid while applying a load of 2.5 N with a pen having a hemispherical polyacetal tip with a radius of 0.8 mm (50,000 reciprocations, sliding distance 30 mm, sliding speed 180 mm/sec). After sliding, the center of the sliding portion is pressed with a pen load of 0.8 N to measure the resistance (ON resistance) when electrically connected.
A transparent conductive film having feature 1 (input start load), feature 2 (voltage loss time), and feature 4 (clearness) is extremely useful for applications such as resistive touch panels.

The transparent conductive film preferably has a film bending resistance (BR) determined by test method 3 of 0.23 N·cm or more and 0.90 N·cm or less. Also, by setting the film bending resistance (BR) to a predetermined value or less, the ON resistance can be set to a predetermined value or less. Reducing the film bending resistance (BR) is also useful for reducing the input starting load. The film bending resistance (BR) is more preferably 0.27 N·cm or more, and still more preferably 0.30 N·cm or more. Also, it is more preferably 0.80 N·cm or less, still more preferably 0.70 N·cm or less, and particularly preferably 0.60 N·cm or less.

[Test method 3]
A 20 mm × 250 mm transparent conductive film test piece is placed on a horizontal table with the transparent conductive film facing up, the test piece is protruded from the end of the table with a length of 230 mm, and the bending resistance (BR ). Note that the bending resistance value changes when the transparent conductive film is placed downward.
Bending resistance (BR (N cm)) = g x a x b x L ⁴ / (8 x δ x 10 ¹¹ )
(In the formula, a is 9.81 (gravitational acceleration; m/s ² ), b is the specific gravity (g/cm ³ ) of the test piece, and L is 230 (the weight of the test piece outside the horizontal table. The length of the long side; mm), and δ indicates the difference (cm) between the height of the tip of the test piece and the height of the table)

In the transparent conductive film, the average (AVSp) of the maximum peak height Sp of the conductive surface determined by Test Method 4 preferably satisfies the following formula (2-1). The input starting load is governed by two parameters, the film bending resistance (BR) and the average maximum peak height (AVSp). By setting , the input start load can be set to a predetermined value or less.
AVSp≧4.7×BR−1.8 Formula (2-1)
(Wherein, BR is film bending resistance (N cm), AVSp is average maximum peak height (μm))
[Test method 4]
On the conductive surface of the transparent conductive film, 3 points at 1 cm intervals in the MD direction and 2 points symmetrically in the TD direction from the center are determined, a total of 5 measurement points, and the maximum peak height Sp due to surface roughness at each point (according to ISO 25178), and the average value is defined as the average maximum peak height (AVSp) (μm).

The relationship of the inequality sign on the right side of formula (2-1) is more preferably AVSp≧4.7×BR-1.7, more preferably AVSp≧4.7×BR-1.6, AVSp≧4.7×BR−1.5 is even more preferred, and AVSp≧4.7×BR−1.4 is particularly preferred. Although the upper limit of AVSp is not limited by the relationship with BR, the effect of the present invention can be achieved even when AVSp≤4.7*BR+10 or AVSp≤4.7*BR+3, for example.

The average maximum peak height (AVSp) of the transparent conductive film preferably satisfies the following formula (2-2). When the average maximum peak height (AVSp) is equal to or greater than a predetermined value, the transparent conductive film can be wound into a roll without any trouble. The average maximum peak height (AVSp) is more preferably 0.010 (μm) or more, still more preferably 0.020 (μm) or more. Also, by setting the average maximum peak height (AVSp) to a predetermined value or less, unintended electrical contact can be more appropriately prevented. The average maximum peak height (AVSp) is more preferably 10.000 (μm) or less, still more preferably 5.000 (μm) or less.
0.005≦AVSp≦12.000 Expression (2-2)
(In the formula, AVSp is the average maximum peak height (μm))

The transparent conductive film preferably has a contact area ratio (CA) determined by test method 5 that satisfies the following formula (2-3). By setting the contact area ratio (CA) to a predetermined value or more, the voltage loss time can be set to a predetermined value or less. Since the greater the contact area ratio (CA), the more stable the electrical contact between the conductive layers, the electrical contact becomes unstable when the pen or finger moves away from the transparent conductive film of the resistive touch panel. It is thought that this is because it is possible to earn time until the contact area becomes equal. In addition, in the formula (2-3), the contact area ratio (CA) increases as the bending resistance (BR) increases. This is because it is necessary to use a transparent conductive film with a large contact area ratio (CA) because the speed of separation from the transparent conductive film of the touch panel increases.
CA≧32.6×BR+17.2 Expression (2-3)
(In the formula, BR is film bending resistance (N cm) and CA is contact area ratio (%))

[Test method 5]
The average height Rc (μm), the maximum peak height Rp (μm), and the average length Rsm (μm) are measured according to the line roughness of the conductive surface of the transparent conductive film, and the formulas (X1) and (X2) are obtained. The arithmetic mean height Ra (μm) based on the line roughness is measured at a place satisfying at least one of and formula (X3). Note that the average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) were obtained , R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 50x)). Maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) are determined according to JIS B 0601-2001. The measurement length of the arithmetic mean height Ra (μm) is 100 μm or more and 200 μm or less.
Rp−Rc−Ra≦0.20 Formula (X1)
(Rp−Rc)/Ra≦5.0 Formula (X2)
Rsm≦30 Expression (X3)
The objective lens of the three-dimensional surface profile measurement device Vertscan was changed to 10 times, and the particle analysis in the same measurement device was used to calculate the arithmetic mean height Ra (μm )−15×10 ⁻³ (μm)−average height Rc (μm)” is sliced in the plane direction, and the sum of cross-sectional areas is obtained. The contact area ratio (CA) (%) is obtained by multiplying the value obtained by dividing the sum of the cross-sectional areas by the area of the measurement visual field and multiplying by 100.

The reason why “arithmetic mean height Ra (μm)−15×10 ⁻³ (μm)” is taken into account in test method 5 is as follows. Most of the transparent conductive film in contact with the transparent conductive glass are protrusions of average height on the transparent conductive film. Since it is difficult to accurately calculate the contact area with the protrusions of this average height, as an alternative index, a height slightly smaller than the average height of the protrusions (= than the average height of the transparent conductive film 15 × 10 ^-3 (μm) low height) using the cross-sectional area of the transparent conductive film side of the transparent conductive film (this height is the average height Rc (μm) lower than the average surface height as a reference). Here, when the arithmetic mean roughness Ra of JIS B 0601-2001 is used as the average height of the protrusions of the transparent conductive film, the number on the transparent conductive film side of the transparent conductive film is small, but the height is very large. The arithmetic mean roughness Ra is larger than the actual average height of the protrusions of the transparent conductive film due to the influence of the large coarse protrusions, which is not preferable. Therefore, in order to eliminate the influence of coarse protrusions, the arithmetic mean height Ra (μm) was measured at a location satisfying at least one of formulas (X1) and (X2) and formula (X3).

The relationship between CA and BR represented by formula (2-3) is more preferably CA≧32.6×BR+17.5, more preferably CA≧32.6×BR+18.0, and CA≧ 32.6×BR+19.0 is even more preferable, and CA≧32.6×BR+30 is particularly preferable. Although the upper limit of CA is not particularly limited in relation to BR, the effects of the present invention can be obtained even when CA≦32.6×BR+85 or CA≦32.6×BR+65, for example.

The transparent conductive film preferably has an arithmetic mean height Sa (according to ISO 25178) of 1 to 55 nm. By setting the arithmetic average height Sa to a predetermined value or less, the size and the number of surface protrusions are reduced, so that light scattering is reduced, the sum of transmitted image clarity is increased, and clearness is improved. By setting the arithmetic mean height Sa to a predetermined value or more, it is possible to realize the effective size and number of surface protrusions for maintaining the film windability. The arithmetic mean height Sa is more preferably 3 nm or more, still more preferably 5 nm or more, more preferably 50 nm or less, and even more preferably 45 nm or less.

In the transparent conductive film, the maximum value MXSp of the maximum peak height Sp determined by Test Method 4 is preferably more than 1.0 times and 1.4 times or less as large as the average maximum peak height AVSp. By setting the maximum value MXSp to a predetermined value or less, the in-plane distribution of tall projections of the transparent conductive film becomes uniform, and input operation of the touch panel can be performed with the same input start load at any location, which is preferable. It is more preferably 1.3 times or less, still more preferably 1.2 times or less.

In the transparent conductive film, the minimum value MNSp of the maximum peak height Sp determined by Test Method 4 is preferably 0.6 to 1.0 times the average maximum peak height AVSp. By setting the minimum value MNSp to a predetermined value or more, the in-plane distribution of the tall projections of the transparent conductive film becomes uniform, and it is possible to perform input on the touch panel with the same input start load at any location, which is preferable. It is more preferably 0.7 times or more, and still more preferably 0.8 times or more.
Further, by setting both the maximum value MXSp and the minimum value MNSp within a predetermined range, the variation in input start load can be reduced to less than ±5%.

The total light transmittance of the transparent conductive film is, for example, 70% or more and 95% or less, preferably 80% or more and 95% or less, more preferably 85% or more and 90% or less.

2. Transparent Conductive Film The transparent conductive film of the transparent conductive film is made of indium-tin composite oxide. The concentration of tin oxide contained in the transparent conductive film is preferably 0.5% by mass or more and 40% by mass or less. When the tin oxide content is 0.5% by mass or more, the surface resistance of the transparent conductive film is at a practical level, which is preferable. Further, by setting the tin oxide concentration to 40% by mass or less, the tin oxide concentration contained in the transparent conductive film of the transparent conductive film can be brought close to the tin oxide concentration contained in the transparent conductive glass substrate for a touch panel. The closer the tin oxide concentration of the transparent conductive film and the transparent conductive film on the glass substrate is, the easier it is for the two transparent conductive films to come into electrical contact, which improves input strength characteristics (misreaction prevention, light input, etc.) and input stability. becomes even better. The tin oxide concentration of the transparent conductive film is more preferably 25% by mass or less, more preferably 20% by mass or less, particularly preferably 18% by mass or less, more preferably 1% by mass or more, and still more preferably 2% by mass. That's it.

The concentration of tin oxide contained 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, more preferably 10% by mass or less.

The crystallinity of the transparent conductive film may be 0% or more and 100% or less, preferably 10% or more and 100% or less, more preferably 50% or more and 100% or less. The higher the degree of crystallinity, the better the pen slidability.

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

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 base material or the curable resin layer described later, and the film quality of the transparent conductive film is stabilized and the surface resistance value is stabilized. It tends to be in the preferred 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, still more preferably 16 nm or more. Further, when the thickness of the transparent conductive film is 100 nm or less, the crystal grain size and crystallinity of the transparent conductive film become appropriate, and the total light transmittance becomes a practical level, which is preferable. It is more preferably 50 nm or less, still more preferably 30 nm or less, and particularly preferably 25 nm or less.

In an adhesion test according to JIS K5600-5-6:1999 on the surface of the transparent conductive film, the residual area ratio of the transparent conductive film is preferably 95% or more, more preferably 99% or more, and particularly Preferably it is 99.5% or more. When the residual area ratio of the transparent conductive film is within the above range in the adhesion test, the transparent conductive film is transparent to layers in contact with the transparent conductive film, such as a transparent plastic film substrate and a curable resin layer described later. The conductive film adheres tightly, preventing cracks, peeling, and abrasion of the transparent conductive film even when continuous input is made with a pen on the touch panel. On the other hand, it is preferable because cracks, peeling, etc. can be suppressed.

The method for forming the transparent conductive film is not particularly limited. A method of forming a transparent conductive film of an indium-tin composite oxide by a sputtering method is preferred. In order to produce a transparent conductive film with high productivity, it is preferable to use a so-called roll sputtering apparatus in which a film to be treated is supplied from a film roll, and after film formation, it is wound up into the shape of a film roll.

FIG. 6 is an apparatus schematic diagram showing an example of a film forming method in a roll type sputtering apparatus. In this illustrated example, a film to be processed 1 delivered from a film roll (not shown) is traveling while partially contacting the surface of the center roll 2 . An indium-tin sputtering target 4 is placed in a chimney 3 having an opening toward the contact portion of the film 1 to be processed and the center roll 2, and the indium-tin sputtering target 4 is placed on the surface of the film 1 to be processed running on the center roll 2. Thin films of composite oxides are deposited and laminated. The temperature of the center roll 2 can be controlled by a temperature controller (not shown).

As for the target, it is preferable to use a sintered target of indium-tin composite oxide. In order to improve production efficiency, a plurality of sintering targets of indium-tin composite oxide may be placed in the film flow direction.

For forming the film-forming atmosphere, it is preferable to flow oxygen gas, inert gas (such as argon gas), etc., while using a mass flow controller as necessary. By adding oxygen gas, the surface resistance and total light transmittance of the transparent conductive film can be made more appropriate. The flow ratio (volume ratio) of oxygen gas and inert gas (oxygen gas/inert gas) is, for example, 0.005 or more, preferably 0.010 or more, more preferably 0.020 or more. 0.15 or less, preferably 0.1 or less, more preferably 0.07 or less, still more preferably 0.05 or less. In addition, the film-forming atmosphere is not particularly limited as long as it contains a hydrogen atom, such as a hydrogen atom-containing gas (hydrogen, ammonia, hydrogen + argon mixed gas, etc.), while using a mass flow controller as necessary. , except for water).

The median value (intermediate value between the maximum value and the minimum value) of the ratio of the water pressure to the inert gas in the film formation atmosphere (water pressure/inert gas partial pressure) is, for example, 7.00×10 ⁻³ or less, It is preferably 5.00×10 ⁻³ or less, more preferably 3.00×10 ⁻³ or less. The less water in the film-forming atmosphere, the more appropriate the film quality of the transparent conductive film, the more likely the surface resistance value becomes a favorable value, and the higher the certainty of crystallization. By the way, it is conceivable to control the water content based on the degree of ultimate vacuum, but it is preferable to measure the water content (water pressure) during film formation for the following two reasons. First, sputtering onto a plastic film heats the film and releases moisture from the film. The ultimate vacuum does not reflect the effect of this amount of released water. Secondly, the degree of vacuum attainment does not reflect the effect of moisture in the center of the roll when the film is unwound from the film roll. When the film roll is held in a vacuum chamber, the water in the outer layer of the roll is easily removed, but the water in the inner layer of the roll is difficult to remove. When the ultimate vacuum is measured, the film is not running, but when the film is formed, the inner layer of the film roll, which contains a lot of water, is unwound. increases, and the water content increases when the ultimate vacuum is measured. The median value of the water pressure ratio (water pressure/inert gas partial pressure) may be 0.3×10 ⁻³ or more.

The film roll for forming the transparent conductive film preferably has a height difference of 10 mm or less between the most convex portion and the most concave portion on the end surface of the roll, more preferably 8 mm or less, and still more preferably 4 mm or less. be. If the thickness is 10 mm or less, water and organic components are less likely to be released from the film end surface when the film roll is put into the sputtering apparatus, and the film quality of the transparent conductive film is improved. The height difference may be 1 mm or more.

It is desirable to pass the film to be treated through a bombardment process before forming the transparent conductive film.
The bombardment process is to generate plasma by applying a voltage to generate a discharge while only an inert gas such as argon gas or a mixed gas of a reactive gas such as oxygen and an inert gas is flowing. . Specifically, it is desirable to bombard the film by RF sputtering with a SUS target or the like. Since the film is exposed to plasma in the bombardment process, water and organic components are released from the film, and the amount of water and organic components released from the film when forming the transparent conductive film is reduced, resulting in good film quality of the transparent conductive film. Become. In addition, since the layer in contact with the transparent conductive film is activated by the bombardment process, the adhesion of the transparent conductive film is improved, and the pen sliding durability is further improved.

It is desirable that the film 1 to be treated has a protective film with a low water absorption rate attached to the surface opposite to the surface on which the transparent conductive film is formed. By attaching the protective film, it becomes difficult for gases such as water to be released from the film 1 to be treated, and the film quality of the transparent conductive film is improved. Examples of base materials for the protective film include olefins such as polyethylene, polypropylene, and cycloolefin.

At the time of film formation, the film 1 to be processed is cooled to, for example, 0°C or lower, preferably -5°C or lower. By cooling the film 1 to be processed, the release of impurities such as water and organic gas from the film can be suppressed, and the film quality of the transparent conductive film can be made appropriate. The film temperature during film formation can be substituted with the set temperature of the temperature controller that adjusts the temperature of the center roll that the running film contacts (if there are multiple set temperatures, the value between the maximum and minimum values). is. The film temperature may be -20°C or higher.

The sputtering apparatus preferably has an exhaust device such as a rotary pump, turbomolecular pump, or cryopump. The amount of moisture in the film-forming atmosphere can be controlled by the exhaust device.

After depositing and laminating a transparent conductive film of indium-tin composite oxide on the film to be processed, heat treatment is performed at 80° C. or more and 200° C. or less for 0.1 hour or more and 12 hours or less in an atmosphere containing oxygen. is desirable. By setting the temperature to 80° C. or higher, the crystallinity of the transparent conductive film can be improved, and the pen sliding durability can be further improved. By setting the temperature to 200° C. or lower, the flatness of the transparent plastic film can be secured. The temperature is preferably 100° C. or higher and 180° C. or lower, more preferably 120° C. or higher and 170° C. or lower. The time is preferably 0.3 hours or more and 6 hours or less, more preferably 0.5 hours or more and 2 hours or less.

3. Transparent plastic film substrate The transparent plastic film substrate used in the present invention is obtained by subjecting an organic polymer to a film by melt extrusion or solution extrusion, stretching in the longitudinal direction and/or the width direction, cooling, heating, if necessary. It is a fixed film. 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; nylon 6, nylon 4, nylon 66, nylon 12 and the like. Polyamides; polyimide, polyamideimide, polyethersulfane, polyetheretherketone, polycarbonate, polyarylate, cellulose propionate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, polyphenylene sulfide, polyphenylene oxide, polystyrene , syndiotactic polystyrene, and norbornene-based polymers.

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

The transparent plastic film substrate may be subjected to surface activation treatment such as corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, ozone treatment, etc., within a range that does not impair the purpose of the present invention. .

The thickness of the transparent plastic film substrate is preferably in the range of 100 µm or more and 240 µm or less, more preferably 120 µm or more and 220 µm or less. The thinner the plastic film, the lower the bending resistance (BR) of the film, and the easier it is for the average maximum peak height (AVSp) to satisfy the formula (2-1). Further, when the thickness of the plastic film is 100 μm or more, the mechanical strength is maintained, so deformation due to pen input when used in a touch panel is small, and pen sliding durability is excellent, which is preferable. On the other hand, when the thickness is 240 μm or less, it is preferable because when used in a touch panel, light input performance and excellent input stability can be maintained.

4. Curable Resin Layer The curable resin layer is formed, for example, between the transparent plastic film substrate and the transparent conductive film, and serves as a base layer for the transparent conductive film. Moreover, since it can block the deposition of monomers and oligomers generated from the transparent plastic film base material on the transparent conductive film, it is preferable because it does not interfere with the comfortable input performance of the touch panel. Furthermore, the transparent conductive film can be strongly adhered to the curable resin layer by the easy-adhesion layer, etc., and the force applied to the transparent conductive film can be dispersed. It is preferable because peeling, wear and the like can be suppressed.

The resin of the curable resin layer is not particularly limited as long as it is cured by applying energy such as heating, ultraviolet irradiation, electron beam irradiation, or by a curing agent. resins, melamine-based resins, polyester-based resins, urethane-based resins, etc., and these may be used alone or in combination of two or more. From the viewpoint of productivity, it is preferable to use an ultraviolet curable resin as a main component.

Examples of UV-curable resins include polyfunctional acrylate resins such as acrylic acid or methacrylic acid esters of polyhydric alcohols, diisocyanates, polyhydric alcohols, and hydroxyalkyl esters of acrylic acid or methacrylic acid. and polyfunctional urethane acrylate resins. If necessary, a monofunctional monomer such as vinylpyrrolidone, methyl methacrylate, or styrene can be added to these polyfunctional resins for copolymerization.

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 includes radical polymerization initiators such as thermal polymerization initiators and photopolymerization initiators, curing agents, etc. Photopolymerization initiators are preferred. The amount of the curing reaction initiator is, for example, 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the curable resin.

As the photopolymerization initiator, any known compound that absorbs ultraviolet rays and generates radicals can be used without particular limitation. Examples include various benzoins, phenylketones, and benzophenones.

The curable resin layer preferably contains particles. The particles can form unevenness on the surface of the curable resin layer. Therefore, when particles are included, the contact area ratio CA basically decreases from 100%, while the control of the average maximum peak height AVSp and the average arithmetic height Sa becomes easier. Also, increasing the amount of particles may lower the bending resistance BR, and it is also possible to adjust the bending resistance BR with the amount of particles. Furthermore, various properties such as pen sliding durability, anti-Newton ring properties, and film winding properties can be more effectively exhibited by the particles.

Examples of the particles include inorganic particles and organic particles. Examples of inorganic particles include silica particles. Examples of organic particles include particles made of polyester resins, polyolefin resins, polystyrene resins, polyamide resins, acrylic resins, and the like. The particles may be of one type or two or more types.

In addition, it is preferable to use monodisperse particles as the particles. By using monodisperse particles as particles having a relatively large particle diameter (for example, particles A described later), even if the total amount of particles added to the curable resin layer is small, the average maximum peak height AVSp can be increased, the average arithmetic height Sa tends to be decreased. Therefore, the use of monodisperse particles as the particles A is effective in achieving both input strength characteristics (erroneous reaction prevention, smooth input, etc.) and clearness. Moreover, there is a tendency that the upper displacement rate and the lower displacement rate of the maximum peak height Sp, which will be described later, can be set to values close to 1.0 times. Monodisperse particles may be used for particles having a relatively small particle size (for example, particles B used in combination with particles A, which will be described later).

Among the particles, the number average particle diameter of particles A having a relatively large particle diameter (even if there is only one type of number average particle diameter, the number average particle diameter is defined as particle A) is, for example, 2 μm or more and 11 μm or less, preferably 2 μm or more. It is 6 μm or less, more preferably 2 μm or more and 5 μm or less. The larger the average particle size, the larger the average maximum peak height AVSp of the transparent conductive layer, the larger the average arithmetic height Sa, and the smaller the value of the contact area ratio CA.
Even if the number average particle diameter of the particles A is 11 μm or less (for example, about 10 μm), the average arithmetic height Sa may become too large when it is sufficiently large relative to the thickness of the curable resin layer. In this case, the average arithmetic height Sa can be reduced by further reducing the number average particle diameter of the particles A or by reducing the amount of the particles A added.
Even if the number average particle diameter of the particles A is 2 μm or more (for example, about 3 μm), the average maximum peak height AVSp may become too small when the difference from the thickness of the curable resin layer is small. In this case, the average maximum peak height AVSp can be increased by increasing the difference between the number average particle diameter of the particles A and the thickness of the curable resin layer.

The standard deviation of the particle size is, for example, 20% or less of the number average particle size, preferably 10% or less of the number average particle size, more preferably 5% or less of the number average particle size. A smaller standard deviation of the particle diameter is preferable because both the upper variation rate and the lower variation rate of the maximum peak height Sp of the transparent conductive film approach 1.0 times.
As the particles A, inorganic particles are acceptable, but organic particles are preferable, and acrylic resin particles are more preferable.

The optimum amount of the particles A in the curable resin layer is, for example, 0.1% by mass or more and 30% by mass or less, preferably 5% by mass or more and 25% by mass with respect to 100% by mass of the solid content of the cured resin layer. It is below. When the amount of the particles A is large, the value of the contact area ratio CA tends to decrease and the average arithmetic height Sa tends to increase. Also, when the thickness of the curable resin layer is large, the optimum addition amount tends to be large. Also, when the density of the curable resin layer is high, the optimum addition amount tends to be small.

In one aspect, in addition to the particles, it is preferable to use particles B having a number average particle diameter of 0.01 μm or more and 1.0 μm or less. Particles B may be of two or more types. If the particle size of the particles B is 0.01 μm or more, small unevenness can be formed on the transparent conductive layer. Since it is possible to prevent sticking (sticking), it is possible to prevent a decrease in accuracy of the touch panel input position, which is preferable. If the particle diameter of the particles B is 1.0 μm or less, the contact area ratio CA tends to be increased, which is preferable.
When the particles B are contained, the amount of the particles B in the curable resin layer is, for example, 0.1% by mass or more and 25% by mass or less, preferably 0.1% by mass or more, and preferably 0.1% by mass or less, based on 100% by mass of the solid content of the cured resin layer. It is 5 mass % or more and 18 mass % or less. When the amount of particles B is large, the value of the contact area ratio CA tends to decrease, and the average arithmetic height Sa tends to increase.
The standard deviation of the particle size of the particles B is, for example, 20% or less of the number average particle size, preferably 10% or less of the average particle size.
As the particles B, organic particles are acceptable, but inorganic particles are preferable, and silica particles are more preferable.

As particles A, monodisperse particles having a size (number average particle diameter) larger than the thickness of the curable resin layer are used and particles B are not included, or particles A having a size (number average particle size) larger than the thickness of the curable resin layer It is preferred to contain particles B using monodisperse particles of large diameter. It is preferable because the average maximum peak height AVSp can be easily controlled by the difference between the size of the particles A (number average particle diameter) and the thickness of the curable resin layer. However, the size (number average particle size) of the particles A is preferably 7 times or less the thickness of the curable resin layer. If the size (number average particle diameter) of the particles A is 7 times or less as large as the thickness of the curable resin layer, the particles tend to be prevented from coming off, which is preferable. The ratio of the number average particle diameter of the particles A to the thickness of the curable resin layer is preferably 1.1 to 6.0, more preferably 1.2 to 5.0.

The thickness of the curable resin layer is preferably in the range of 0.1 µm or more and 10 µm or less. It is more preferably in the range of 0.2 μm or more and 7 μm or less, and particularly preferably in the range of 0.3 μm or more and 5 μm or less. When the thickness of the curable resin layer is 0.1 μm or more, it is preferable because sufficient protrusions can be formed and the added particles can be prevented from coming off. In addition, when the curable resin layer is thick, it tends to increase the bending resistance BR of the transparent conductive film. On the other hand, if it is 10 μm or less, it is preferable because the productivity is good and the average maximum peak height AVSp can be set to an appropriate value.

By adjusting the size and amount of the particles and the thickness of the curable resin layer as described above, while the average maximum peak height AVSp of the transparent conductive layer satisfies the formula (2-1), the contact area ratio CV and the transmission It is possible to prevent the sum of image sharpness from becoming too small. Also, the bending resistance BR and the average arithmetic height Sa of the film can be adjusted. Therefore, the input start load can be controlled to be small, the voltage loss time can be shortened, the sum of transmission image definition can be increased, and light input, input stability, and clearness can be achieved.

The curable resin layer may contain a resin that is incompatible with the curable resin (hereinafter sometimes simply referred to as an incompatible resin). By dispersing the incompatible resin in the curable resin layer, unevenness can be formed on the surface of the curable resin layer, and the surface roughness in a wide area can be improved. Examples of non-compatible resins include polyester resins, polyolefin resins, polystyrene resins, polyamide resins, and the like.

The curable resin layer is formed by liquefying the curable resin before curing, applying it to the layering target (transparent plastic film substrate, easy adhesive layer, etc.) and curing. In addition to the curable resin, the coated material includes a curing reaction initiator (a thermal polymerization initiator, a radical polymerization initiator such as a photopolymerization initiator, a curing agent, etc., preferably a photopolymerization initiator), particles, and a curable resin. It may contain incompatible resins, solvents, and the like. If necessary, other known additives such as a silicone-based leveling agent may be added to this coating liquid. The solvent to be used is not particularly limited, and examples thereof include alcohol solvents such as ethyl alcohol and isopropyl alcohol, ester solvents such as ethyl acetate and butyl acetate, and dibutyl ether and ethylene glycol monoethyl ether. Ether-based solvents, ketone-based solvents such as methyl isobutyl ketone and cyclohexanone, and aromatic hydrocarbon-based solvents such as toluene, xylene, solvent naphtha, and the like can be used singly or in combination.

The concentration of the curable resin in the coating liquid (referred to as the solid content concentration) can be appropriately selected in consideration of the viscosity, etc. 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, the average maximum peak height AVSp tends to increase, the average arithmetic height Sa tends to increase, and the contact area ratio CA tends to decrease.

The method of coating the object to be laminated with the coating liquid is not particularly limited, and known methods such as bar coating, gravure coating, and reverse coating can be used, for example. In the coating liquid coated, the solvent is removed by evaporation in the next drying step. When an incompatible resin (such as a polyester resin) is dissolved in the coating liquid, the incompatible resin becomes particles and precipitates in the ultraviolet curable resin in this drying step. After drying the coating film, a curable resin layer can be formed by performing an appropriate treatment (for example, ultraviolet irradiation) according to the type of curing.

The coating surface to be laminated may be treated to improve the adhesion of the curable resin layer, if necessary, before the coating liquid is applied. Examples of adhesion improvement treatment include discharge treatment in which glow or corona discharge is applied to increase carbonyl groups, carboxyl groups, and hydroxyl groups, and acid or alkali treatment to increase polar groups such as amino groups, hydroxyl groups, and carbonyl groups. A chemical treatment method, etc., to be treated can be mentioned.

As described above, in order to set the average maximum peak height AVSp, the contact area ratio CA, and the average arithmetic height Sa within the predetermined ranges, it is necessary to adjust various factors. The details are as described above, but to summarize without elaborating, the following relationships can be used for adjustment. That is, basically, when the particle diameter is large, the solid content concentration is high, or the thickness of the resin layer is thin, the absolute value of the average maximum peak height AVSp and the average arithmetic height Sa tend to increase. The average maximum peak height AVSp that satisfies the formula (2-1) varies depending on the bending resistance BP, and the smaller the bending resistance BP, the smaller the average maximum peak height AVSp. Also, basically, as the average maximum peak height AVSp and the average arithmetic height Sa increase, the contact area ratio CA decreases. However, when two types of large and small average particle sizes are used as the average particle size to be added to the resin layer, monodisperse particles are used as the large particles, and the amount of large particles added is reduced, the average maximum peak height AVSp is high and the contact area ratio CV is low. and the average arithmetic height Sa becomes lower. When two types of large and small particles are used, the smaller the amount of large particles added, the greater the influence of the average particle size and amount of small particles on the contact area ratio CA and average arithmetic height Sa.

5. Functional Layer The functional layer is preferably basically the same as the curable resin layer except that it is formed on the opposite side of the transparent plastic film substrate. All (including type of curable resin layer, thickness of curable resin layer, solids concentration of curable resin layer, type of particles, etc.) apply to the functional layer except for the description of thickness and amount. By laminating the functional layer on the transparent plastic film substrate, precipitation of monomers and oligomers from the transparent plastic film substrate can be prevented, and deterioration of the visibility of the transparent conductive film can be suppressed. Moreover, the bending resistance BR of the transparent conductive film can be adjusted. In addition, it is preferable that the transparent plastic film base material has a functional layer, because it is less likely to be scratched due to input with a pen or the like.

In order to improve clearness, it is preferred that the functional layer basically does not contain particles. However, particles (particles C) may be added to the functional layer for the purpose of adjusting the bending resistance BR of the transparent conductive film and maintaining film windability. When particles are added, the number average particle diameter of the particles C is, for example, 0.01 μm or more and 1.0 μm or less, preferably 0.01 μm or more and 0.8 μm or less, more preferably 0.01 μm or more and 0.8 μm or less. 5 μm or less.
The content of the particles C is preferably 0.1 parts by mass or more and 50 parts by mass or less, more preferably 0.3 parts by mass or more and 30 parts by mass or less, and still more preferably 0 parts by mass, per 100 parts by mass of the curable resin in the functional layer. .5 mass parts or more and 20 mass parts or less. Depending on the amount of particles C, the bending resistance BR of the transparent conductive film can be adjusted. In addition, the particles C can form surface protrusions on the functional layer, and the film windability can be maintained.
The particles C can be selected from the same types as the particles of the curable resin layer, and may be organic particles, but inorganic particles are preferred, and silica particles are more preferred.

In an adhesion test according to JIS K5600-5-6:1999 on the surface of the functional layer, the residual area ratio of the functional layer is preferably 95% or more, more preferably 99% or more, and particularly preferably 99.5% or more. In the adhesion test, the residual area ratio of the functional layer is within the above range, so that the transparent conductive film adheres to the transparent plastic film base and the functional layer, and even if continuous input is made with a pen on the touch panel, the functional layer does not. On the other hand, appearance defects such as cracks, peeling, and wear are suppressed, and even if a force stronger than expected for normal use is applied, cracks, peeling, etc. are suppressed in the functional layer, which is preferable.

When the transparent conductive film has a functional layer and a cured resin layer, the functional layer and the cured resin layer preferably have the same thickness, and the absolute value of the difference in thickness between the functional layer and the cured resin layer satisfies the following relationship: It is preferable to have
0.1 μm≦|Thickness of cured resin layer−Thickness of functional layer|≦3 μm
By providing a thickness difference between the functional layer and the cured resin layer, it may be possible to adjust the bending resistance BR of the transparent conductive film. In addition, various properties such as pen sliding durability can be more effectively exhibited. Furthermore, input strength characteristics (erroneous reaction prevention, smooth input characteristics, etc.) can be further improved. The thickness difference (absolute value) may be 2 μm or less.
Moreover, 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.

6. Easy-Adhesive Layer The easy-adhesive layer is preferably formed from a composition containing a urethane resin, a cross-linking agent, and a polyester resin. The cross-linking agent is preferably a blocked isocyanate, more preferably a tri- or more functional blocked isocyanate, and particularly preferably a tetra- or more functional blocked isocyanate. The thickness of the easy-adhesion layer is preferably 0.001 μm or more and 2.00 μm or less.

This application claims the benefit of priority based on Japanese Patent Application No. 2022-021557 filed on February 15, 2022. The entire contents of the specification of Japanese Patent Application No. 2022-021557 filed on February 15, 2022 are incorporated herein by reference.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited by these examples. Various measurement evaluations in the examples were performed by the following methods.

1. Measurement evaluation (1) Average particle size of silica particles and acrylic particles Randomly select three observation sites from each cross section of the curable resin layer or functional layer of the transparent conductive film, and examine the particles at each observation site with a scanning electron microscope. (manufactured by KEYENCE CORPORATION, VE-8800), 50 particles were randomly extracted from each observation point, and the particle diameter of each was observed. Next, the particle diameter (equivalent circle diameter) of the observed 50 particles was divided into sections of 0.020 μm, and the total number of particles contained in each section was obtained. A histogram of particle size in 0.020 μm intervals was generated. From the histogram, the number average of observed particle diameters was taken as the average particle diameter for particles having particle diameters within ±30% of the absolute value of the central value of the particle diameter interval taking the peak value of the normal distribution. For example, when there are two peaks in the normal distribution in the histogram, it indicates that two types of particles are added, and the average particle size of the two types was calculated by the same method as described above. The average particle size of the curable resin layer at three locations was further averaged, and the average particle size of the curable resin layer and the average particle size of the functional layer at three locations were further averaged to obtain the average particle size of the functional layer. .

(2) Thickness of curable resin layer and thickness of functional layer The thickness of the curable resin layer is obtained by observing the cross section of the transparent conductive film with a scanning electron microscope (manufactured by Keyence Corporation, VE-8800) (5000 times). , 5 arbitrary points were observed, and the average value thereof was used as the thickness. A similar method was adopted for the thickness of the functional layer.

(3) Content of Tin Oxide in Transparent Conductive Film A sample was cut (approximately 15 cm ² ) and placed in a quartz Erlenmeyer flask, 20 ml of 6 mol/l hydrochloric acid was added, and the film was sealed to prevent volatilization of the acid. . The transparent conductive film was dissolved by allowing it to stand at room temperature for 9 days with occasional shaking. The remaining film was taken out, and hydrochloric acid in which the transparent conductive film was dissolved was used as a measuring solution. In and Sn in the solution were determined by calibration curve method using an ICP emission spectrometer (manufacturer: Rigaku, device type: CIROS-120 EOP). As the measurement wavelength for each element, a wavelength with no interference and high sensitivity was selected. In addition, standard solutions of commercially available In and Sn were diluted and used.

(4) Thickness of Transparent Conductive Film A sample piece of film laminated with a transparent conductive thin film layer was cut into a size of 1 mm×10 mm and embedded in an epoxy resin for electron microscopes. The epoxy resin has a trade name of "Epon812" (Nacalai Tesque Co., Ltd.) as a main agent, a trade name of "MNA" (Nacalai Tesque Co., Ltd.) as a curing agent, and a trade name of "DNP-30" (Nacalai Tesque Co., Ltd.) as an accelerator. Company), which was mixed at a volume ratio of main agent:curing agent:accelerator=100:89:1.5 and cured at 60° C. for 12 hours. A sample piece encapsulated in epoxy resin was fixed to a sample holder of an ultramicrotome, and a cross-sectional slice parallel to the short side of the embedded sample piece was prepared. Then, a transmission electron microscope (manufactured by JEOL, JEM-2010) is used to photograph a portion of the section where the thin film is not significantly damaged at an acceleration voltage of 200 kV and a bright field with an observation magnification of 10,000 times. The film thickness was obtained from the obtained photograph.

(5) Crystallinity of Transparent Conductive Film A film sample piece laminated with a transparent conductive film was cut into a size of 1 mm×10 mm and adhered to the upper surface of a suitable resin block with the conductive film surface facing outward. The resin block has a product name of "Epon812" (Nacalai Tesque Co., Ltd.) as the main agent, a product name of "MNA" (Nacalai Tesque Co., Ltd.) as the curing agent, and a product name of "DNP-30" (Nacalai Tesque Co., Ltd.) as the accelerator. Company), which was prepared by mixing the main agent:curing agent:accelerator=100:89:1.5 by volume and curing at 60° C. for 12 hours. After trimming the sample piece attached to the resin block, an ultra-thin section approximately parallel to the film surface was made by a common ultramicrotome technique. This section was observed with a transmission electron microscope (JEM-2010, manufactured by JEOL), and the conductive thin film surface portion without significant damage was selected and photographed at an acceleration voltage of 200 kV and a direct magnification of 40,000. As the crystallinity evaluation of the transparent conductive film, the ratio of crystal grains observed under a transmission electron microscope, that is, the degree of crystallinity was observed.

(6) Total light transmittance (%)
Total light transmittance was measured according to JIS-K7361-1:1997 using NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd.

(7) Surface resistance Measured by the four-probe method in accordance with JIS-K7194:1994. Lotesta AX MCP-T370 manufactured by Mitsubishi Chemical Analytech Co., Ltd. was used as the measuring instrument.

(8) Adhesion test It was carried out in accordance with JIS K5600-5-6:1999. The results in the table below show the adhesion as a residual area ratio (%). The maximum value of the residual area ratio is 100%. The closer the residual area ratio in the adhesion test in the table is to 100%, the smaller the peeled area.

(9) Bending resistance (BR) (test method 3)
A test piece of 20 mm×250 mm was taken from the transparent conductive film, and the test piece was placed on a horizontal table with a smooth surface so that the transparent conductive film faced upward. Only a 20 mm×20 mm portion from one end of the test piece was placed on a horizontal stand, and a 20 mm×230 mm portion was projected horizontally from the end of the stand. A weight was placed on a 20 mm×20 mm portion of the test piece, and the weight and size of the weight were selected so as not to create a gap between the test piece and the horizontal table. Next, the difference (.delta.) between the height of the horizontal stage and the height of the leading edge of the film was read on the scale. The bending resistance was calculated by substituting numerical values into the following formula.
Bending resistance BR (N cm) = g x a x b x L ⁴ / (8 x δ x 10 ¹¹ )
(In the formula, a is 9.81 (gravitational acceleration; m/s ² ), b is the specific gravity (g/cm ³ ) of the test piece, and L is 230 (the weight of the test piece outside the horizontal table. The length of the long side; mm), and δ indicates the difference (cm) between the height of the tip of the test piece and the height of the table)
The above specific gravity b was measured by the following method.
The transparent conductive film was cut into a square of 5.0 cm on each side, and the total thickness was measured at 10 different locations using a micrometer with three significant digits, and the average value (t: μm) of the thickness was obtained. The weight (w:g) of a sample cut into a square of 5.0 cm square was measured using an automatic top-pan balance with 4 significant digits, and the specific gravity was obtained from the following equation. The specific gravity was rounded to two significant digits.
Specific gravity b (g/cm ³ )=w/(5.0×5.0×t×10 ⁻⁴ )

(10) Maximum peak height (Sp), average maximum peak height AVSp (μm) (test method 4)
The maximum peak height (Sp) (ISO; surface roughness) was measured at 5 points from the conductive surface of the transparent conductive film, and the arithmetic mean value was defined as the average maximum peak height (AVSp). As for how to select five points, an arbitrary one point A is first selected. Next, two points in total, one point each at 1 cm upstream and downstream of A in the longitudinal (MD) direction of the film, are selected. Next, two points in total, one point on each side of 1 cm in the width (TD) direction of the film with respect to A, are selected. The maximum peak height (Sp) (ISO; surface roughness) is specified in ISO25178, and is a three-dimensional surface profile measuring device Vertscan (manufactured by Ryoka Systems Co., Ltd., R5500H-M100 (measurement conditions: wave mode, measurement It was obtained using a wavelength of 560 nm and an objective lens of 10 times)). Values less than 1 nm were rounded off.

(11) Maximum peak height upper displacement ratio (MXSp/AVSp), maximum peak height lower displacement ratio (MNSp/AVSp)
The ratio between the maximum value MXSp and the average value AVSp of the maximum peak height Sp obtained by the test method 4 was taken as the maximum peak height upper displacement rate (MXSp/AVSp).
Also, the ratio (MNSp/AVSp) of the minimum value MNSp and the average value AVSp of the maximum peak height Sp determined by test method 4 was taken as the maximum peak height downward displacement rate.

(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), the maximum peak height Rp (μm), and the average length Rsm (μm) are measured according to the line roughness of the conductive surface of the transparent conductive film, and the formulas (X1) and (X2) are obtained. Arithmetic mean height Ra (μm) based on line roughness was measured at a location satisfying at least one of and formula (X3). Note that the average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) were obtained , R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 50x)). The maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) were determined according to JIS B 0601-2001. The measurement length of the arithmetic mean height Ra (μm) was 100 μm or more and 200 μm or less.
Rp−Rc−Ra≦0.20 Formula (X1)
(Rp−Rc)/Ra≦5.0 Formula (X2)
Rsm≦30 Expression (X3)
The objective lens of the three-dimensional surface profile measurement device Vertscan was changed to 10 times, and the particle analysis in the same measurement device was used to determine the "arithmetic mean height Ra (μm) -15 × 10 ^-3 (μm) from the average surface. -Average height Rc (μm)” was sliced in the plane direction using the height as a threshold, and the sum of cross-sectional areas was obtained. The contact area ratio (CA) (%) was obtained by multiplying the value obtained by dividing the total cross-sectional area by the area of the measurement field and multiplying it by 100.

(13) Input start load measurement (test method 1)
After setting a glass substrate (size: 232 mm×151 mm) in a sputtering apparatus, the pressure was evacuated to 1.5×10 ⁻⁴ Pa. Next, after introducing 10 mPa of oxygen, argon was introduced to make the total pressure 0.6 Pa. Using an indium-tin composite oxide sintering target, power is applied at a power density of 3 W/cm ² , and a 20 nm-thick indium-tin composite oxide conductive film (oxidized tin content: 10% by weight). Next, on the surface of the conductive film, dot spacers (length 60 μm × width 60 μm × height 5 μm) of UV curable resin (trade name “CR-103C-1” (manufactured by Toyobo Co., Ltd.)) are placed in a square grid pattern at a pitch of 4 mm. (ITO glass substrate). Double-sided tape (trade name: #741 (manufactured by Ebisu Kasei Kogyo Co., Ltd.)) is applied to the transparent conductive film side so that a rectangle of 190 mm x 135 mm can be formed starting from one of the four corners of the ITO glass substrate. (thickness: 105 μm, width: 6 mm) was pasted. The adhered double-faced tape forms an adhesive rectangular frame having a thickness of 105 μm and an inner circumference of 190 mm×135 mm. A transparent conductive film (size: 220 mm × 135 mm) obtained in Examples or Comparative Examples was pasted on a rectangular frame (double-sided tape) attached to an ITO glass substrate without tension. It laminated|stacked so that it might face each other. At this time, one short side of the transparent conductive film protruded from the ITO glass substrate (evaluation panel).
The ITO glass substrate and the transparent conductive film of the obtained evaluation panel were connected with a tester. Load is applied from the transparent conductive film side with a polyacetal pen (trade name “TPS (registered trademark) POM (NC)” manufactured by Toray Plastics Precision Co., Ltd., tip shape: 0.8 mmR) and measured with a tester. The load value when the measured resistance value stabilized (that is, when the fluctuation of the resistance value fell within the range of ±5%) was taken as the input start load.
The position 12 where the load was applied by the pen was the central region of the four dot spacers 11 arranged in a lattice on the surface of the ITO glass substrate 10 as shown in FIG. Also, the input start load was measured at arbitrary three points at a distance of 50 mm or more from the double-sided tape, and the average value was taken. The first decimal place was rounded off.

(14) Voltage loss time measurement (test method 2)
A constant-voltage power supply is connected to the evaluation panel prepared in the input start load measurement. Next, a recorder (GR-7000 manufactured by Keyence Corporation) capable of measuring the voltage between the ITO glass substrate and the transparent conductive film is connected. Here, the recorder is used to observe changes in voltage over time. Next, 6 V is applied to the constant-voltage power source, and the recorder starts measuring the voltage in units of 0.02 milliseconds. Next, from the transparent conductive film side, a polyacetal pen (trade name “TPS (registered trademark) POM (NC)” manufactured by Toray Plastics Precision Co., Ltd., tip shape: 0.8 mmR) was applied five times per second ( A load of 50 g is applied at a pace of one stroke of 30 mm). The position where the load is applied by the pen is the center area of the four dot spacers arranged in a lattice. Take out the data of the time change of the voltage when a load is applied to the transparent conductive film with a pen from the recorder. Starting when the pen started to separate from the transparent conductive film and the voltage decreased from 6 V, the time until the voltage reached 5 V was measured and recorded as the voltage loss time (see FIG. 5). Three measurements were averaged.

(15) Input strength test (erroneous reaction prevention/quick input)
A resistive touch panel was produced using the transparent conductive films obtained in Examples and Comparative Examples. Specifically, first, a glass substrate (size: 232 mm×151 mm) was placed in a sputtering apparatus and then evacuated to 1.5×10 ⁻⁴ Pa. Next, after introducing 10 mPa of oxygen, argon was introduced to make the total pressure 0.6 Pa. Using an indium-tin composite oxide sintering target, power is applied at a power density of 3 W/cm ² , and a 20 nm-thick indium-tin composite oxide conductive film (oxidized tin content: 10% by weight). Next, on the surface of the conductive film, dot spacers (circular (length 30 μm × width 30 μm) × height 4 μm) of UV curable resin (trade name “CR-103C-1” (manufactured by Toyobo Co., Ltd.)) are placed at a pitch of 4 mm. It was formed in the shape of a square lattice (ITO glass substrate). Double-sided tape (trade name: #741 (manufactured by Ebisu Kasei Kogyo Co., Ltd.)) is applied to the transparent conductive film side so that a rectangle of 190 mm x 135 mm can be formed starting from one of the four corners of the ITO glass substrate. (thickness: 105 μm, width: 6 mm) was pasted. The adhered double-faced tape forms an adhesive rectangular frame having a thickness of 105 μm and an inner circumference of 190 mm×135 mm. A transparent conductive film (size: 220 mm × 135 mm) obtained in Examples or Comparative Examples was pasted on a rectangular frame (double-sided tape) attached to an ITO glass substrate without tension. It laminated|stacked so that it might face each other. At this time, one short side of the transparent conductive film protruded from the ITO glass substrate. Two X-coordinate positioning wirings were attached to the ITO glass substrate, and two Y-coordinate positioning wirings were attached to the transparent conductive film to form a four-wire analog resistive touch panel.
A polyacetal pen (trade name “TPS (registered trademark) POM (NC)” manufactured by Toray Plastics Precision Co., Ltd., tip shape: 0.8 mmR) was used to examine the input strength.
(misreaction prevention)
○: Even if the pen slightly touches the touch panel (load of about 1 to 2 g), no input is made to the touch panel.
x: When the pen slightly touches the touch panel (load of about 1 to 2 g), an input may be made to the touch panel.
(Light input)
○: Input can be made with a light touch force (load of about 3 to 15 g), that is, without intentionally applying a strong force.
x: Input is not possible with a light touch force (load of about 3 to 15 g), that is, unless a strong force is intentionally applied.

(16) Input stability (payment stability, stenography stability)
Using the transparent conductive films obtained in Examples and Comparative Examples, the same touch panel as the 4-wire analog type resistive touch panel used in (15) Input strength test (erroneous reaction prevention / light input) Created. A polyacetal pen (trade name “TPS (registered trademark) POM (NC)” manufactured by Toray Plastics Precision Co., Ltd., tip shape: 0.8 mmR) was used to examine input stability.
(payment stability)
◯: When characters are input, the printed portion is less likely to be blurred.
×: When characters are input, the printed portion is easily blurred.
(shorthand)
◯: Characters are less likely to be blurred when characters are input continuously.
x: Characters are easily blurred when characters are input continuously.

(17) Pen sliding durability (test method 6)
After setting a glass substrate (size: 60 mm×50 mm) in a sputtering apparatus, the vacuum was drawn down to 1.5×10 ⁻⁴ Pa. Next, after introducing 10 mPa of oxygen, argon was introduced to make the total pressure 0.6 Pa. Using an indium-tin composite oxide sintering target, power is applied at a power density of 3 W/cm ² , and a 20 nm-thick indium-tin composite oxide conductive film (oxidized tin content: 10% by weight). Double-sided tape (trade name "No. 500", manufactured by Nitto Denko Co., Ltd.) (thickness: 170 μm, width 5 mm). The adhered double-faced tape forms an adhesive rectangular frame having a thickness of 170 μm and an inner circumference of 40 mm×40 mm. A transparent conductive film of the transparent conductive film (size: 60 mm × 50 mm) obtained in Examples or Comparative Examples is pasted without tension on a rectangular frame (double-sided tape) attached to an ITO glass substrate. It laminated|stacked so that it might face each other. At this time, the transparent conductive film was made to protrude from the ITO glass substrate (evaluation panel).
The ITO glass substrate and the transparent conductive film of the obtained evaluation panel were connected with a tester. Next, a polyacetal pen (trade name “TPS (registered trademark) POM (NC)”, manufactured by Toray Plastics Precision Co., Ltd., tip shape: 0.8 mmR) was applied with a load of 2.5 N, and a straight line of 50,000 reciprocations was applied. A sliding test was performed on the touch panel. The sliding point was near the center of the evaluation panel. The sliding distance at this time was 30 mm, and the sliding speed was 180 mm/sec. After this sliding durability test, the ON resistance (resistance value when the movable electrode (film electrode) and the fixed electrode are in contact) was measured when the center of the sliding portion was pressed with a pen load of 0.8N. More preferably, the ON resistance is 10 kΩ or less.

(18) Sum of transmission image clarity An image clarity measuring instrument (Suga Co., Ltd.) using an optical comb of 0.125 mm width, 0.25 mm width, 0.5 mm width, 1 mm width, or 2 mm width for a transparent conductive film It was measured according to JIS K7374 with an image clarity measuring instrument ICM-1T manufactured by Test Instruments. The sum of transmitted image sharpness for each optical comb was calculated.

(19) Average arithmetic height Sa
The transparent conductive layer side of the transparent conductive film is measured using a three-dimensional surface profile measurement device Vert Scan (R5500H-M100 manufactured by Ryoka Systems Co., Ltd. (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 10 times)). The average arithmetic height Sa was determined according to ISO 25178. The number of measurements was set to 5, and their average value was obtained. Here, the first decimal place in nm units was rounded off.

2. Laminate Film In the section of Examples, a laminate film composed of the following transparent plastic film substrate, curable resin layer, and functional layer was used.
(1) Substrates Substrate 1 (transparent plastic film substrate): A biaxially oriented transparent PET film having easy-adhesion layers on both sides (manufactured by Toyobo Co., Ltd., A4380, thickness is shown in Table 1). (Examples 1 to 8 and Comparative Examples 1, 2, 3, 6, and 7 correspond)
Substrate 2 (transparent plastic film substrate): A biaxially oriented transparent PET film having an easy-adhesion layer on one side and no easy-adhesion layer on the other side (manufactured by Toyobo Co., Ltd., A4180, the thickness is shown in Table 1). ). (Comparative Examples 4 and 5 correspond)
Base material 3 (transparent plastic film base material): Bemcot obtained by immersing the easy-adhesive surface of a biaxially oriented transparent PET film (manufactured by Toyobo Co., Ltd., A4180, thickness is shown in Table 1) having no easy-adhesive layer on one side in methyl ethyl ketone. (manufactured by Asahi Kasei Corporation) to remove the easily adhesive layer. (Comparative Example 8 corresponds)

(2) Curable resin layer Photopolymerization initiator-containing acrylic resin (manufactured by Dainichiseika Kogyo Co., Ltd., Seika Beam (registered trademark) EXF-01J) 100 parts by mass, particles having a number average particle diameter described in Table 1 (particles A and particles B) were blended in the amounts shown in Table 1. As the particles A, monodispersed acrylic particles or polydispersed acrylic particles were used. As the particles B, monodispersed silica particles were used. A mixed solvent of toluene/methyl ethyl ketone (MEK) (8/2: mass ratio) was added so that the solid content concentration was the value shown in Table 1, and the coating liquid was uniformly dissolved by stirring to prepare a coating liquid (coating liquid A). . Coating solution A prepared so that the thickness of the coating film would be 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, the coating film was cured by irradiating ultraviolet rays (light amount: 300 mJ/cm ² ) using an ultraviolet irradiation device (manufactured by Eye Graphics, UB042-5AM-W type). .

(3) Functional layer In 100 parts by mass of a photopolymerization initiator-containing acrylic resin (manufactured by Dainichiseika Kogyo Co., Ltd., Seika Beam (registered trademark) EXF-01J), silica particles having a number average particle diameter shown in Table 2 (particles C ) was blended in the amounts shown in Table 2. A mixed solvent of toluene/MEK (8/2: mass ratio) was added as a solvent so that the solid content concentration became the value shown in Table 2, and the mixture was uniformly dissolved by stirring to prepare a coating liquid (coating liquid C). Coating solution C, which was prepared so that the thickness of the coating film was the value shown in Table 2, was applied to the surface of the transparent plastic film substrate opposite to the curable resin layer using a Meyer bar. After drying at 80° C. for 1 minute, the coating film was cured by irradiating ultraviolet rays (light amount: 300 mJ/cm ² ) using an ultraviolet irradiation device (manufactured by Eye Graphics, UB042-5AM-W type). .

Examples 1-8
The laminated film was placed in a vacuum chamber and evacuated to 1.5×10 ⁻⁴ Pa. Next, after introducing oxygen, argon was introduced to make the total pressure 0.6 Pa. Table 3 shows the flow ratios of oxygen and argon.
As shown in FIG. 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 in the chimney 3 . A sintered target of indium-tin composite oxide (the concentration of tin oxide is shown in Table 3. The balance is indium oxide) was used as the target 4, and power was supplied at a power density of 3 W/cm ² to perform DC magnetron sputtering. A transparent conductive film was formed by the method. Film thickness was controlled by varying the speed at which the film passed over the target.
In addition, the ratio of water pressure to argon in the film forming atmosphere during sputtering was measured using a gas analyzer (Transpector XPR3, manufactured by INFICON), and is shown in Table 3. As shown in Table 3, the moisture ratio is determined by the presence or absence of a bombardment process, the presence or absence of a protective film, the height difference between the unevenness of the film roll end surface, and the temperature controller that controls the temperature of the center roll on which the film travels in contact. It was regulated by adjusting the temperature of the heating medium. In the bombardment process, RF sputtering was performed using SUS (stainless steel) as a target at 0.5 W/cm ² . The amount of gas introduced in RF sputtering was the same as the amount of gas introduced into the vacuum apparatus described in the examples. When using the 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. A protective film was attached to the surface of the laminated film opposite to the surface on which the transparent conductive film was formed. As for the temperature of the hot medium, the temperature described in Table 3 was taken as the temperature right in the middle between the maximum and minimum temperatures from the start of film formation on the film roll to the end of film formation.
A transparent conductive film was obtained by subjecting the film laminated with the transparent conductive film to the heat treatment shown in Table 3.
Regarding the obtained transparent conductive film, the thickness of the transparent conductive film, the crystallinity, the total light transmittance (%), the surface resistance (Ω/□), the adhesion to the transparent conductive film, the adhesion to the functional layer evaluated. Table 4 shows the results.

For the obtained transparent conductive film, bending resistance (BR), average maximum peak height (AVSp), contact area ratio (CA), maximum peak height upper displacement ratio (MXSp/AVSp), maximum peak height lower displacement ratio (MNSp/AVSp) was determined. Table 5 shows the results.

Sum of input start load, voltage loss time, input strength test (erroneous reaction prevention, light input), input stability (wiping stability, stenography stability), and transmission image clarity for the obtained transparent conductive film , and pen sliding durability. Table 6 shows the results.

Comparative Examples 1-8
Transparent conductive films were prepared in the same manner as in Examples 1 to 8, except that the laminate films prepared under the conditions shown in Tables 1 and 2 were used and the transparent conductive films were formed under the conditions shown in Table 3. In Comparative Example 6, an indium oxide sintered target containing no tin oxide was used as the target 4 instead of the indium-tin composite oxide sintered target. Various properties of the obtained films are shown in Tables 4 to 6.

Transparent conductive films can be widely used in electrical and electronic fields, such as flat panel displays such as liquid crystal displays and electroluminescence (EL) displays, and transparent electrodes for touch panels.

REFERENCE SIGNS LIST 1 film to be processed 2 center roll 3 chimney 4 target 5 transparent conductive film 6 curable resin layer 7 transparent plastic film substrate 8 functional layer 9 easy-adhesive layer 10 ITO glass substrate 11 dot spacer 12 position to apply load with pen 13 hours 14 voltage 15 voltage loss time

Claims (10)

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 start load determined by test method 1 is 3 g or more and 15 g or less,
   The voltage loss time determined by test method 2 is 0.00 ms or more and 0.40 ms or less,
   Each of the five types of transmission measured in accordance with JIS K7374 with an image clarity measuring instrument using five types of optical combs of 0.125 mm width, 0.25 mm width, 0.5 mm width, 1 mm width, or 2 mm width. A transparent conductive film having a total image definition of 400 to 500%.
   [Test method 1]
   A 20 nm-thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) was formed on one side of a glass substrate, and dot spacers (length 60 µm x width 60 µm x height 5 µm) were formed on the surface of the thin film. A panel plate is formed by forming a square lattice with a pitch of 4 mm. On the conductive film side of this panel plate, while sandwiching an adhesive rectangular frame having a thickness of 105 μm and an inner circumference of 190 mm×135 mm, transparent conductive films were laminated so that the conductive films face each other to prepare an evaluation panel. do. From the transparent conductive film side of this evaluation panel, the center of the four-point lattice of the dot spacer is pressed with a pen made of hemispherical polyacetal with a tip radius of 0.8 mm, and the pressure when the resistance value starts to stabilize is measured. Input starting load.
   [Test method 2]
   The evaluation panel is connected to a 6 V constant voltage power supply, and a pen whose tip is a hemisphere with a radius of 0.8 mm is used to apply a load of 50 gf to the center of the four-point lattice of the dot spacer from the transparent conductive film side 5 times / second. Press at intervals of . Starting when the pen begins to separate from the transparent conductive film and the voltage decreases from 6 V, the time until the voltage reaches 5 V is measured and defined as the voltage loss time.
2. The film bending resistance (BR) determined by test method 3 is 0.23 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 formulas (2-1) and (2-2),
   The contact area ratio (CA) determined by test method 5 satisfies the following formula (2-3),
   2. The transparent conductive film according to claim 1, wherein the arithmetic mean height Sa (according to ISO 25178) satisfies 1 to 55 nm.
   AVSp≧4.7×BR−1.8 Formula (2-1)
   0.005≦AVSp≦12.000 Expression (2-2)
   CA≧32.6×BR+17.2 Expression (2-3)
   (Wherein, BR is the film bending resistance (N cm), AVSp is the average maximum peak height (μm), and CA is the contact area ratio (%))
   [Test method 3]
   A 20 mm × 250 mm transparent conductive film test piece is placed on a horizontal table with the transparent conductive film facing up, the test piece is protruded from the end of the table with a length of 230 mm, and the bending resistance (BR ).
   Bending resistance (BR (N cm)) = g x a x b x L ⁴ / (8 x δ x 10 ¹¹ )
   (In the formula, a is 9.81 (gravitational acceleration; m/s ² ), b is the specific gravity (g/cm ³ ) of the test piece, and L is 230 (the weight of the test piece outside the horizontal table. The length of the long side; mm), and δ indicates the difference (cm) between the height of the tip of the test piece and the height of the table)
   [Test method 4]
   On the conductive surface of the transparent conductive film, 3 points at 1 cm intervals in the MD direction and 2 points symmetrically in the TD direction from the center are determined, a total of 5 measurement points, and the maximum peak height Sp due to surface roughness at each point (according to ISO 25178), and the average value is defined as the average maximum peak height (AVSp) (μm).
   [Test method 5]
   The average height Rc (μm), the maximum peak height Rp (μm), and the average length Rsm (μm) are measured according to the line roughness of the conductive surface of the transparent conductive film, and the formulas (X1) and (X2) are obtained. The arithmetic mean height Ra (μm) based on the line roughness is measured at a place satisfying at least one of and formula (X3). Note that the average height Rc (μm), maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) were measured , R5500H-M100 (measurement conditions: wave mode, measurement wavelength 560 nm, objective lens 50x)). Maximum peak height Rp (μm), average length Rsm (μm), and arithmetic mean height Ra (μm) are determined according to JIS B 0601-2001. The measurement length of the arithmetic mean height Ra (μm) is 100 μm or more and 200 μm or less.
   Rp−Rc−Ra≦0.20 Formula (X1)
   (Rp−Rc)/Ra≦5.0 Formula (X2)
   Rsm≦30 Expression (X3)
   The objective lens of the three-dimensional surface profile measurement device Vertscan was changed to 10 times, and the particle analysis in the same measurement device was used to determine the "arithmetic mean height Ra (μm) -15 × 10 ^-3 (μm) from the average surface. -Average height Rc (μm)” is used as a threshold value to slice in the plane direction, and the sum of cross-sectional areas is obtained. The contact area ratio (CA) (%) is obtained by multiplying the value obtained by dividing the sum of the cross-sectional areas by the area of the measurement visual field and multiplying by 100.
3. The maximum value MXSp of the maximum peak height Sp determined by the test method 4 is more than 1.0 times and 1.4 times or less than the average maximum peak height AVSp, and
   3. The transparent conductive film according to claim 2, wherein the minimum value MNSp of the maximum peak height Sp obtained by the test method 4 is 0.6 times or more and 1.0 times or less as large as the average maximum peak height AVSp.
4. The transparent conductive film according to claim 1 or 2, wherein the transparent conductive film has a thickness of 10 nm or more and 100 nm or less.
5. The transparent conductive film according to claim 1 or 2, 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. Having a curable resin layer between the transparent conductive film and the transparent plastic film substrate,
   3. The transparent conductive film according to claim 1, further comprising a functional layer on the opposite side of the transparent plastic substrate to the transparent conductive film.
7. The transparent conductive film according to claim 1 or 2, which has an easy-adhesion layer on at least one side of the transparent plastic film substrate.
8. 8. The transparent conductive film according to claim 7, wherein the easy-adhesion layer is arranged at least one position between the transparent plastic film substrate and the curable resin layer or between the transparent plastic substrate and the functional layer. .
9. 3. The transparent conductive film according to claim 1, wherein the ON resistance determined by test method 6 is 10 k[Omega] or less.
   [Test method 6]
   A panel plate having a 20 nm-thick indium-tin composite oxide conductive film (tin oxide content: 10% by mass) formed on one side of a glass substrate and a transparent conductive film are stacked so that the conductive films face each other. to create an evaluation panel. The transparent conductive film side of this evaluation panel is slid while applying a load of 2.5 N with a pen having a hemispherical polyacetal tip with a radius of 0.8 mm (50,000 reciprocations, sliding distance 30 mm, sliding speed 180 mm/sec). After sliding, the center of the sliding portion is pressed with a pen load of 0.8 N to measure the resistance (ON resistance) when electrically connected.
10. The transparent conductive film according to claim 1 or 2, wherein the transparent conductive film has a residual area ratio of 95% or more in an adhesion test according to JIS K5600-5-6:1999 on the surface of the transparent conductive film.

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