TWI813867B - Transparent Conductive Film - Google Patents

Abstract

The present invention provides a transparent conductive film that is excellent in pen sliding durability and pen heavy pressure durability when used in a touch panel. The transparent conductive film of the present invention is a transparent conductive film with an indium-tin composite oxide layered on at least one area of a transparent plastic film base material, and is a transparent conductive film obtained by a pen sliding durability test The ON resistance of the transparent conductive film is 10 kΩ or less, and the increase rate of the surface resistance value of the transparent conductive film obtained from the pen weight test is 1.5 or less.

Description

Transparent conductive membrane

The present invention relates to a transparent conductive film formed by laminating a transparent conductive film of crystalline indium-tin composite oxide on a transparent plastic film base material. In particular, it relates to a resistive film touch panel. A transparent conductive diaphragm with excellent pen sliding durability and heavy pressure durability.

A transparent conductive film formed by laminating a transparent and low-resistance thin film on a transparent plastic base material is widely used in applications that utilize the conductivity of the transparent conductive film, such as liquid crystal displays or EL (Electroluminescent; They are widely used in electrical and electronic fields such as flat panel displays such as electroluminescent displays or transparent electrodes of touch panels.

Resistive film touch panels are composed of a fixed electrode coated with a transparent conductive film on a glass or plastic substrate and a movable electrode (also known as a diaphragm electrode) coated with a transparent conductive film on a plastic film. It is used by superimposing it on the upper side of the display body. Pressing the diaphragm electrode with a finger or a pen makes the fixed electrode and the transparent conductive film of the diaphragm electrode contact each other, which becomes an input for identifying the position of the touch panel. Compared with fingers, pens exert stronger force on touch panels in most cases. If input is continued on the touch panel with a pen, the transparent conductive film on the diaphragm electrode side may be damaged such as cracking, peeling, or abrasion. In addition, if a force exceeding the normal expected use is applied to the touch panel, such as strongly tapping the touch panel with a pen or inputting with a very strong force, the transparent conductive film may crack or peel. Waiting for destruction. In order to solve these problems, a transparent conductive film having both excellent pen sliding durability and excellent pen heavy pressure durability is desired.

As a method of improving the pen sliding durability, there is a method of making the transparent conductive film on the diaphragm electrode side crystalline (see, for example, Patent Document 1). However, conventional transparent conductive films have achieved a transparent conductive film with excellent pen sliding durability by controlling the crystallinity of indium-tin composite oxide. However, if the conventional transparent conductive film is subjected to the pen weight pressure durability test described below, the pen weight pressure durability is insufficient.

[Prior technical literature]

[Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2004-071171.

In view of the above-mentioned conventional problems, an object of the present invention is to provide a transparent conductive film that is excellent in pen sliding durability when used in a touch panel and is also excellent in pen heavy pressure durability.

The present invention was made in view of the above-described situation, and the transparent conductive film of the present invention that can solve the above-mentioned problems has the following structure.

1. A transparent conductive film, which is formed by layering a transparent conductive film of indium-tin composite oxide on at least one area of a transparent plastic film base material, and is obtained by the following pen sliding durability test The ON resistance of the transparent conductive film of the transparent conductive film is 10 kΩ or less, and the increase rate of the surface resistance value of the transparent conductive film of the transparent conductive film is obtained from the following pen load test. 1.5 or less.

[Pen sliding durability test method]

The transparent conductive film of the present invention is used as one of the panel plates, and an indium-tin composite oxide film (tin oxide content: 10 mass%) with a thickness of 20 nm is formed on a glass substrate by a sputtering method. The transparent conductive film is used as another panel board. The aforementioned two panel plates are arranged with transparent conductive films facing each other through epoxy beads with a diameter of 30 μm, and a double-sided tape with a thickness of 170 μm is used to attach the panel plate on the film side to the glass side. Panel boards are used to make touch panels. Then, a load of 2.5N was applied to the pen made of polyacetal (top shape: 0.8mmR), and the touch panel was subjected to a linear sliding test of 180,000 back and forth times. In this test, a pen load was applied to the surface of the transparent conductive film of the present invention.

At this time, the sliding distance is set to 30mm and the sliding speed is set to 180mm/s. After the sliding durability test, the on-resistance (the resistance value when the movable electrode (diaphragm electrode) comes into contact with the fixed electrode) is measured when the sliding part is pressed with a pen load of 0.8N.

[Pen weight and pressure test method]

The transparent conductive film of the present invention cut into 50mm×50mm was used as one of the panel plates, and an indium-tin composite oxide film (tin oxide) with a thickness of 20nm was formed on the glass substrate by sputtering. A transparent conductive film composed of 10% by mass) was used as another panel board. The two panel plates are arranged facing each other with transparent conductive films through epoxy beads with a diameter of 30 μm, and a double-sided tape with a thickness adjusted to 120 μm is used to attach the panel plate on the diaphragm side to the panel plate. Use the panel on the glass side to make the touch panel. Use a polyacetal pen (top shape 0.8mmR) to apply a load of 35N at a position 2.0mm away from one end of the double-sided tape, and slide it linearly 10 times (5 times back and forth) parallel to the double-sided tape. In this test, a pen load was applied to the surface of the transparent conductive film of the present invention. At this time, the sliding distance is set to 30mm and the sliding speed is set to 20mm/s. Slide where there are no epoxy beads. After sliding, remove the transparent conductive film and measure the surface resistance (four) of any five places on the sliding part. Terminal method), get the average value. When measuring the surface resistance, arrange the four terminals in a direction perpendicular to the sliding part so that the sliding part comes between the second terminal and the third terminal. Divide the average surface resistance value of the sliding part by the surface resistance value of the unsliding part (measured by the four-terminal method) to calculate the increase rate of the surface resistance value.

2. The transparent conductive film as described in item 1 above, wherein the crystal grain size of the transparent conductive film of the indium-tin composite oxide is 10 nm to 100 nm, and the crystallinity of the transparent conductive film of the indium-tin composite oxide is is 20% to 80%, the transparent conductive film of the indium-tin composite oxide contains 0.5 mass% to 10 mass% tin oxide, the thickness of the transparent conductive film of the indium-tin composite oxide is 10nm to 30nm, indium- The three-dimensional surface roughness SRa of the transparent conductive film of the tin composite oxide is 1 nm to 100 nm.

3. The transparent conductive film as described in the above 1 or 2, that is, the adhesion test (JIS (Japanese Industrial Standards; Japanese Industrial Standards) K5600-5-6: 1999) is performed on the surface of the transparent conductive film, The transparent conductive film still does not peel off. Conduct a bending resistance test (JIS K5600-5-1: 1999) on the transparent conductive film side of the indium-tin composite oxide of the transparent conductive film. Observe the bending with a 10x magnifying glass. The diameter of the mandrel when cracking or peeling occurs is less than 20mm.

4. The transparent conductive film as described in any one of items 1 to 3 above, wherein the thickness of the transparent conductive film is 100 μm to 250 μm.

5. The transparent conductive film according to any one of the above 1 to 4, wherein there is a curable resin layer between the transparent conductive film of the indium-tin composite oxide and the transparent plastic film base material.

According to the present invention, it is possible to provide a transparent conductive film that has both excellent pen sliding durability and excellent pen heavy pressure durability. The obtained transparent conductive film is extremely useful in applications such as resistive film touch panels.

1: membrane

2: Center roller

3: flue

4: Indium-tin composite oxide target

[Fig. 1] is a schematic diagram showing one example (Example 1) of the longest portion of a crystal grain in the present invention.

[Fig. 2] is a schematic diagram showing another example (Example 2) of the longest portion of a crystal grain in the present invention.

[Fig. 3] is a schematic diagram showing another example (Example 3) of the longest portion of the crystal grain in the present invention.

[Fig. 4] is a schematic diagram showing another example (Example 4) of the longest portion of the crystal grain in the present invention.

[Fig. 5] is a schematic diagram for explaining the position of the center roller in one example of the sputtering device that can be preferably used in the present invention.

The transparent conductive film of the present invention is formed by layering a transparent conductive film of indium-tin composite oxide on at least one area of a transparent plastic film base material, and the transparency obtained by the following pen sliding durability test The on-resistance of the transparent conductive film of the conductive film is 10 kΩ or less, and the increase rate of the surface resistance value of the transparent conductive film of the transparent conductive film obtained from the following pen load test is 1.5 or less.

[Pen sliding durability test]

The transparent conductive film of the present invention is used as one of the panel plates, and an indium-tin composite oxide film (tin oxide content: 10 mass%) with a thickness of 20 nm is formed on a glass substrate by a sputtering method. The transparent conductive film is used as another panel board. The two panel plates are arranged facing each other with transparent conductive films through epoxy beads with a diameter of 30 μm, and a double-sided tape with a thickness of 170 μm is used to attach the panel plate on the film side to the glass side. Panel boards are used to make touch panels. Then, a polyacetal pen (top shape: 0.8mmR) was used to apply a load of 2.5N, and the touch panel was subjected to a linear sliding test of 180,000 back and forth times. In this test, a pen load was applied to the surface of the transparent conductive film of the present invention. At this time, the sliding distance is set to 30mm and the sliding speed is set to 180mm/s. Resistant to this sliding After the durability test, the on-resistance (resistance value when the movable electrode (diaphragm electrode) is in contact with the fixed electrode) is measured when the sliding part is pressed with a pen load of 0.8N.

[Pen weight pressure test]

A transparent conductive film obtained by cutting the transparent conductive film of the present invention into 50 mm × 50 mm is used as one of the panel plates, and an indium-tin layer with a thickness of 20 nm is formed on a glass substrate by sputtering. A transparent conductive film composed of a composite oxide film (tin oxide content: 10% by mass) was used as another panel board. The two panel plates are arranged facing each other with transparent conductive films through epoxy beads with a diameter of 30 μm, and a double-sided tape with a thickness adjusted to 120 μm is used to attach the panel plate and glass on the film side The side panel uses a board to make a touch panel. Use a polyacetal pen (top shape 0.8mmR) to apply a load of 35N at a position 2.0mm away from one end of the double-sided tape, and slide it linearly 10 times (5 times back and forth) parallel to the double-sided tape. In this test, a pen load was applied to the surface of the transparent conductive film of the present invention. At this time, the sliding distance is set to 30mm and the sliding speed is set to 20mm/s. Among them, slide in the position where there are no epoxy beads. After sliding, remove the transparent conductive film, measure the surface resistance at any five places on the sliding part (four-terminal method), and obtain the average value. When measuring the surface resistance, arrange the four terminals in a direction perpendicular to the sliding part so that the sliding part comes between the second terminal and the third terminal. Divide the average surface resistance value of the sliding part by the surface resistance value of the unsliding part (measured by the four-terminal method) to calculate the increase rate of the surface resistance value.

The transparent conductive film of the present invention has excellent pen sliding durability and pen heavy pressure durability. Pen sliding durability and pen heavy pressure durability are in conflict with each other. First, the pen sliding durability will be explained. The transparent conductive film of indium-tin composite oxide with excellent pen sliding durability requires a high degree of crystallinity and a large grain size of the transparent conductive film, and the three-dimensional surface roughness of the transparent conductive film is small. The three-dimensional surface roughness will be explained below. First, the crystallinity and grain size will be explained. under a transmission electron microscope The observed portion having a circular or polygonal shape is defined as crystals (that is, crystal grains) of the transparent conductive film, and the other portions are defined as amorphous. The so-called high crystallinity means that the ratio of crystallization is high. The so-called large crystal grain size means a large circular or polygonal area observed under a transmission electron microscope. A transparent conductive film with a high degree of crystallinity has a high ratio of hard crystals, and a transparent conductive film with a large crystal grain size has an increased strain around the crystal grains, so the transparent conductive film becomes hard and has excellent pen sliding durability. This goes on to illustrate the durability of the pen under heavy pressure. The transparent conductive film of the indium-tin composite oxide that has excellent durability under heavy pressure is a transparent conductive film with low crystallinity and small grain size. A transparent conductive film with low crystallinity has a high ratio of soft amorphous materials, and a transparent conductive film with a small crystal grain size has reduced strain around the crystal grains, so even if a load is applied to the transparent conductive film, cracks are less likely to occur. etc., the pen has excellent durability under heavy pressure. As described above, it was found that the pen sliding durability and the pen heavy pressure durability have contradictory properties. As a result of the research, the following invention was reached: By controlling the crystallinity and grain size of the transparent conductive film, it is possible to achieve both pen sliding durability and pen heavy pressure durability. A transparent conductive film having a transparent conductive film that has both pen sliding durability and pen heavy pressure durability will be described.

In the present invention, if the on-resistance of the transparent conductive film of the transparent conductive film obtained by the pen sliding durability test is 10 kΩ or less, even if the pen is used for continuous input to the touch panel, the turtle of the transparent conductive film Cracks, peeling, wear, etc. are still suppressed, so it is better. In one aspect, the on-resistance can be below 9.5 kΩ, and more preferably below 5 kΩ. The on-resistance may be, for example, 3 kΩ or less, 1.5 kΩ or less, and preferably 1 kΩ or less. If the on-resistance is 0 kΩ, the pen sliding durability will be very excellent. According to the present invention, the on-resistance may be 0 kΩ. The on-resistance may be, for example, 3 kΩ or more, or 5 kΩ or more.

When the on-resistance is within this range, even if continuous input is made to the touch panel with a pen, cracks, peeling, abrasion, etc. of the transparent conductive film are suppressed.

In one of the aspects, these upper and lower limits may also be appropriately combined.

In the present invention, it is preferable that the increase rate of the surface resistance value of the transparent conductive film of the transparent conductive film obtained by the pen heavy pressure test is 1.5 or less. By having such characteristics, for example, even if a strong force exceeding the intended normal use is applied, cracking, peeling, etc. of the transparent conductive film can be suppressed. More preferably, the increase rate of the surface resistance value is 1.2 or less, and particularly preferably 1.0 (no increase).

Here, the increase rate of the surface resistance value of the transparent conductive film of the present invention is preferably 1.0 or more.

In one aspect, the on-resistance of the transparent conductive film of the transparent conductive film obtained by the pen sliding durability test is 0.05 or more and 9.5 or less, and the on-resistance of the transparent conductive film obtained by the pen heavy pressure (durability) test is The increase rate of the surface resistance value of the transparent conductive film of the transparent conductive film is 1.0 or more and 1.5 or less.

As mentioned above, pen sliding durability and pen heavy pressure durability generally have conflicting properties. In the present invention, it is possible to have these two durability properties in a good balance within this range. In addition, even if the touch panel is continuously input with a pen, cracks, peeling, abrasion, etc. of the transparent conductive film can be suppressed, and excellent performance can be displayed against loads caused by pen sliding and heavy pen pressure. Durability. In addition, the range and value described in this specification can be selected as a numerical range.

It is preferable that the transparent conductive film of the present invention does not peel off even when the adhesion test (JIS K5600-5-6: 1999) is performed on the transparent conductive film surface. The transparent conductive film that does not peel off during the adhesion test is a transparent conductive film that is in close contact with a layer such as a transparent plastic base material or a cured resin layer that is in contact with the transparent conductive film. Therefore, even if a pen is used to touch the touch panel It is preferable that cracks, peeling, abrasion, etc. of the transparent conductive film are suppressed by continuous input. Furthermore, even if a force exceeding the intended normal use is applied, cracks, peeling, etc. of the transparent conductive film are suppressed.

The transparent conductive film of the present invention is preferably a transparent conductive film of indium-tin composite oxide with a crystal grain size of 10 nm to 100 nm, and a crystallinity of the transparent conductive film of indium-tin composite oxide with a crystallinity of 20%. to 80%. If the crystal grain size of the transparent conductive film of the indium-tin composite oxide is 10 nm or more, the transparent conductive film becomes moderately hard due to strain around the crystal grains of the transparent conductive film, so the pen sliding durability is excellent, and therefore it is relatively good. More preferably, the crystal grain size of the transparent conductive film of the indium-tin composite oxide is 30 nm or more.

On the other hand, if the crystal grain size of the transparent conductive film of the indium-tin composite oxide is 100 nm or less, the strain around the crystal grains of the transparent conductive film will not cause the transparent conductive film to become too hard, so the pen will be heavy. It is preferred because it has excellent pressurization durability. More preferably, the crystal grain size of the transparent conductive film of the indium-tin composite oxide is 90 nm or less.

In one aspect, the crystal grain size of the transparent conductive film of the indium-tin composite oxide is from 30 nm to 95 nm, for example, from 40 nm to 90 nm.

It is preferable that the crystallinity of the transparent conductive film of the indium-tin composite oxide is 20% or more because the hard crystals occupying the transparent conductive film are moderately hardened and the pen sliding durability is excellent. More preferably, the crystallinity of the transparent conductive film of the indium-tin composite oxide is 25% or more. On the other hand, if the crystallinity of the transparent conductive film of the indium-tin composite oxide is 80% or less, the transparent conductive film will not become too hard even though the content of hard crystals is high, so the pen will not become too hard under heavy pressure. Excellent, therefore better.

In one aspect, the crystallinity of the transparent conductive film of the indium-tin composite oxide is from 25% to 78%, for example, from 25% to 76%.

The transparent conductive film of the present invention preferably has a three-dimensional surface roughness SRa of 1 nm to 100 nm. If the three-dimensional surface roughness SRa of the transparent conductive film is 1nm to 100nm, the surface protrusions of the transparent conductive film are small, so the deformation of the surface protrusions during the pen weight test becomes smaller and the occurrence of cracks in the transparent conductive film is suppressed. Furthermore, it is preferable to have slight surface protrusions on the transparent conductive film, so that the rollability of the film sheet can be maintained. More preferably, the three-dimensional surface roughness SRa of the transparent conductive film is 1 nm to 80 nm. Furthermore, it is preferable that the three-dimensional surface roughness SRa of the transparent conductive film is 1 nm to 65 nm.

The transparent conductive film of the present invention is preferably composed of indium-tin composite oxide and contains 0.5 mass% or more and 10 mass% or less tin oxide. Tin oxide in the indium-tin composite oxide is equivalent to an impurity for indium oxide. Due to the inclusion of tin oxide impurities, the melting point of the indium-tin composite oxide increases. That is, the inclusion of tin oxide impurities acts in the direction of inhibiting crystallization, and is therefore an important factor strongly related to crystallinity such as crystal grain size and crystallinity. If the tin oxide content is 0.5% by mass or more, the surface resistance of the transparent conductive film becomes a practical level, which is preferable. Furthermore, the tin oxide content is preferably 1% by mass or more, more preferably 2% by mass or more. When the content of tin oxide is 10% by mass or less, crystallization after adjusting to a semi-crystalline state described below is likely to occur, and the pen sliding durability becomes good, which is preferable. The content rate of tin oxide is more preferably 8 mass% or less, further preferably 6 mass% or less, and particularly preferably 4 mass% or less. Furthermore, the surface resistance of the transparent conductive film of the present invention is preferably 50Ω/□ to 900Ω/□, more preferably 50 to Ω/□600Ω/□.

In the present invention, the thickness of the transparent conductive film is preferably from 10 nm to 30 nm. The thickness of the transparent conductive film is an important factor that is strongly related to crystallinity such as crystal grain size and crystallinity. If the thickness of the transparent conductive film is 10 nm or more, the amorphous film will not be too much in the transparent conductive film, and it is easy to provide an appropriate crystal grain size and crystallinity to create a semi-crystalline state described later. As a result, pen sliding durability is maintained and is preferable. . More preferably, the thickness of the transparent conductive film is 13 nm or more, more preferably 16 nm or more. In addition, if the thickness of the transparent conductive film is 30 nm or less, the crystal grain size of the transparent conductive film will not become too large, the crystallinity will not become too high, and the semi-crystalline state will be easily maintained, and the pen weight durability will be maintained. And better. More preferably, it is 28 nm or less, and still more preferably, it is 25 nm or less.

The transparent conductive film of the present invention is preferably subjected to a bending resistance test (JIS K5600-5-1: 1999) on the transparent conductive film side of the transparent conductive film. When observing the bent portion with a 10x magnifying glass, the The diameter of the mandrel that is cracked or peeled is less than 20mm. If the diameter of the mandrel is less than 20mm, add more weight to the sutra pen. During the pressure test, the layer in contact with the transparent conductive film does not break, and the transparent conductive film does not crack, so it is preferable. Preferably, it is below 18mm.

In one aspect, the value of the bending resistance test may be above 1 mm, for example, above 8 mm or above 10 mm. In addition, in one of the aspects, the value of the bending resistance test is 13 mm or more, and may be 15 mm or more.

This range is preferable because the layer in contact with the transparent conductive film will not be broken during the pen heavy pressure test and the transparent conductive film will not be cracked.

In addition, it is possible to provide a transparent conductive film that has both excellent pen sliding durability and excellent pen heavy pressure durability.

The transparent conductive film of the present invention is preferably a transparent plastic film base material with a thickness in the range of 100 μm to 250 μm, more preferably 130 μm to 220 μm. If the thickness of the plastic film is 100 μm or more, the mechanical strength is maintained, and the deformation for pen input is small, especially when used in a touch panel, and the pen sliding durability and pen heavy pressure durability are excellent, so it is preferable. On the other hand, if the thickness is 250 μm or less, it is preferable because there is no need to particularly increase the load for positioning by pen input when used in a touch panel.

The transparent conductive film of the present invention preferably has a hardening resin layer between the transparent conductive film and the plastic film base material. By having a hardened resin layer, the adhesive force of the transparent conductive film can be increased or the force applied to the transparent conductive film can be dispersed, so cracks, peeling, abrasion, etc. of the transparent conductive film in the pen sliding test are reduced. It is preferable because it suppresses cracking, peeling, etc. of the transparent conductive film during the heavy pressure test of the pen.

The crystallinity of the transparent conductive film of the present invention is not too high and not too low (such crystallinity is called semi-crystalline or semi-crystalline). It is very difficult to stably make a transparent conductive film into a semi-crystalline system. The reason is that the state that stops midway during the rapid phase transition from amorphous to crystalline is semi-crystalline. Therefore, it is sensitive to the amount of water in the film-forming atmosphere, which is a parameter related to crystallinity, and is particularly sensitive to gas containing hydrogen atoms. If the amount of gas or water containing hydrogen atoms in the film-forming atmosphere is slightly smaller, it will almost become Complete crystallinity (high crystallinity). On the contrary, if the amount of gas or water containing hydrogen atoms in the film-forming atmosphere is slightly too much, it will become amorphous (low crystallinity).

The manufacturing method for obtaining the transparent conductive film of the present invention is not particularly limited. For example, the following manufacturing method can be preferably exemplified.

As a method for forming a transparent conductive film of crystalline indium-tin composite oxide on at least one side of the transparent plastic film base material, sputtering can be preferably used. In order to produce a transparent conductive film with high productivity, it is preferable to use a so-called roll sputtering device that supplies a film roll and winds it into the shape of the film roll after film formation. It can be preferably used: in the film-forming atmosphere, use a mass flow controller to introduce a gas containing hydrogen atoms (as long as it is hydrogen, ammonia, hydrogen + argon mixed gas, etc.) in the amount described below. The gas of hydrogen atoms is not particularly limited (excluding water), and the film temperature during sputtering is set to below 0°C, and an indium-tin composite oxide containing 0.5% to 10% by mass of tin oxide is used. The sintered target is adjusted so that the thickness of the transparent conductive film of the indium-tin composite oxide is 10 nm to 30 nm, and the three-dimensional surface roughness SRa of the transparent conductive film of the indium-tin composite oxide is 1 nm to 100 nm. A transparent conductive film is formed on the transparent plastic film. In the film-forming atmosphere during sputtering, gas containing hydrogen atoms has the effect of hindering the crystallization of the transparent conductive film. When hydrogen gas flows in the film-forming atmosphere, the value of (hydrogen gas flow rate) ÷ (inert gas flow rate + hydrogen gas flow rate) × 100 (sometimes described only as hydrogen concentration) is preferably 0.01% to 3.00%. The hydrogen concentration may be, for example, 0.01% or more and 2.00% or more, or 0.01% or more and 1.00% or less.

By having the hydrogen concentration within this range, it can help to derive good results in, for example, the pen sliding durability test and the pen heavy pressure durability test.

Examples of the inert gas include helium gas, neon gas, argon gas, krypton gas, xenon gas, and the like. If it is 0.01% to 3.00%, the transparent conductive film can be made semi-crystalline, which is preferable. When using a hydrogen atom-containing gas other than hydrogen, it can be calculated by converting the hydrogen atom weight contained in the hydrogen atom-containing gas into the hydrogen gas (i.e., hydrogen molecule) amount. When the gas containing hydrogen atoms is precisely flowed by the mass flow controller in the film-forming atmosphere, the gas containing hydrogen atoms can be sprayed uniformly in a direction perpendicular to the length direction of the film roller. When the gas ejection port is provided, the transparent conductive film is less likely to be mixed with highly crystalline parts or low crystallinity parts, and it is easy to obtain a uniform semi-crystalline transparent conductive film, so it is possible to better obtain both. Transparent conductive diaphragm with excellent pen sliding durability and pen heavy pressure durability. It is known that if there is a lot of water in the film-forming atmosphere, the crystallinity of the transparent conductive film decreases, so the moisture content in the film-forming atmosphere is also an important factor. When a gas containing hydrogen atoms is used, the central value (the middle value between the maximum value and the minimum value) of the ratio of the water pressure of the film-forming atmosphere to the inert gas when the film roll is sputtered is controlled to 1.0×10 ^-4 to 2.0×10 ^-3 , and furthermore, regarding the ratio of the water pressure of the film-forming atmosphere to the inert gas during sputtering, if the difference between the maximum value and the minimum value from the beginning of the film formation to the end of the film formation is 1.0×10 ^-3 or less, the uniformity of the crystallinity of the transparent conductive film is maintained throughout the entire length of the diaphragm. Therefore, in addition to the rotary pump, turbomolecular pump, and freezing pump that are often used as exhaust devices for sputtering machines, In addition, the following bombarding step, the following limitation of the height difference of the unevenness of the film roll end surface, etc. are carried out to reduce the amount of moisture released from the film when forming the transparent conductive film throughout the entire length of the film. It is better to release a uniform amount of water, which eliminates the need for precise control of the amount of water. Among them, the central value of the ratio of the water pressure to the inert gas also slightly depends on the content rate of tin oxide in the transparent conductive film of the indium-tin composite oxide or the thickness of the transparent conductive film. When the amount of tin oxide added to the transparent conductive film of the indium-tin composite oxide is large or when the transparent conductive film is thin, it is preferable to set the central value of the ratio of the water pressure to the inert gas within the aforementioned range. Medium is set to low. On the other hand, when the content rate of tin oxide in the transparent conductive film of the indium-tin composite oxide is small or the transparent conductive film is thick, it is preferable to set the central value of the ratio of the water pressure to the inert gas to Set to high in the aforementioned range. It is preferable to set the film temperature during sputtering to below 0°C, and to form a transparent conductive film on the transparent plastic film. The temperature of the film during film formation is replaced by the set temperature of the temperature regulator. The temperature regulator adjusts the temperature of the center roller in contact with the traveling film. Here, FIG. 5 shows a schematic diagram of one example of a sputtering device that can be preferably used in the present invention. The traveling diaphragm 1 partially contacts the surface of the center roller 2 while traveling. An indium-tin sputtering target 4 is provided via a chimney 3, and a thin film of indium-tin composite oxide is deposited on the surface of the film 1 traveling on the center roller 2. The temperature of the center roller 2 is controlled by a temperature regulator (not shown). If the film temperature is 0°C or lower, it is possible to suppress the release of impurity gases such as water and organic gases from the film that causes uneven crystallinity of the transparent conductive film, so the transparent conductive film from the beginning to the end of the film formation can be suppressed. The crystallinity of the film is easy to become uniform, so it is preferred. When a gas containing hydrogen atoms is used, it is preferable that the central value (the middle value between the maximum value and the minimum value) of the ratio of the water pressure of the film-forming atmosphere to the inert gas during sputtering is 1.0×10 ^-4 to 2.0×10 ^-3 . It is preferable that the ratio of the water pressure of the film-forming atmosphere to the inert gas during sputtering is within the above range because the gas containing hydrogen atoms effectively inhibits the crystallinity of the transparent conductive film. In addition, in order to set the surface resistance and total light transmittance of the transparent conductive film to practical levels, it is preferable to add oxygen during sputtering. The manufacturing method mainly focuses on controlling the crystallinity by using hydrogen-containing gas to eliminate as much as possible the influence of crystallinity caused by water, which causes uneven crystallinity of the transparent conductive film.

For the following two reasons, in order to control the moisture content when the indium-tin composite oxide is formed on the plastic film, it is better to actually observe the moisture content during the film formation than to observe the vacuum degree.

As the first reason for the above, if a plastic diaphragm is formed by sputtering, the diaphragm is heated and moisture is released from the diaphragm. Therefore, the amount of moisture in the film-forming atmosphere increases, and is higher than that measured when the vacuum degree is reached. The specified moisture content increases, so it is more accurate to express it in terms of the moisture content during film formation than to express it in terms of the degree of vacuum reached.

The second reason for the above is that at this time, a device using a large amount of transparent plastic film is used. The reason is that this device puts the film in the form of a film roller. If the film sheet is made into a roller and put into a vacuum tank, although water easily escapes from the outer layer of the roller, it is difficult for water to escape from the inner layer of the roller. When the measurement reaches the vacuum degree, although the film roller stops, the film roller moves forward during film formation, so the inner layer of the film roller containing a large amount of water is rolled out, so the moisture content in the film forming atmosphere increases. Compared with the measurement reaching the vacuum degree, The moisture content increases even more under vacuum. In the present invention, when controlling the moisture content in the film-forming atmosphere, a better response can be achieved by observing the ratio of the water pressure of the film-forming atmosphere to the inert gas during sputtering.

It is preferable to subject the film to an impact step before forming the transparent conductive film. The so-called impact step refers to applying a voltage to discharge and generate plasma 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 preferable to impact the diaphragm by RF (Radio Frequency; radio frequency) sputtering using a SUS (Stainless Steel; stainless steel) target or the like. The diaphragm is exposed to plasma through the impact step, so water or organic components are released from the diaphragm. When the transparent conductive film is formed, the water or organic components released from the diaphragm are reduced, so from the beginning of film formation to the completion of It is preferable because the crystallinity of the transparent conductive film until the completion of the film can easily become uniform. In addition, it is preferable that the layer in contact with the transparent conductive film is activated by the impact step, so that the adhesion of the transparent conductive film is improved, and therefore the sliding durability of the pen or the durability of the pen under heavy pressure are improved.

The film roller used to form the transparent conductive film is preferably located on the end surface of the roller, and the height difference between the most protruding part and the most concave part is 10 mm or less. If it is 10 mm or less, when the film roll is put into the sputtering device, the deviation in the way water or organic components are released from the end surface of the film becomes smaller, so the transparent conductivity from the beginning to the end of the film formation It is preferable because the crystallinity of the film can be easily made uniform.

In the method of forming a transparent conductive film of crystalline indium-tin composite oxide on at least one side of a transparent plastic film base material, it is preferable to introduce oxygen during sputtering. If oxygen is introduced during sputtering, there will be no disadvantages caused by oxygen deficiency in the transparent conductive film of the indium-tin composite oxide. The surface resistance of the transparent conductive film will be low, and the total light transmittance will be high. Better. Therefore, in order to increase the surface resistance and total light transmittance of the transparent conductive film to practical levels, it is preferable to introduce oxygen during sputtering. Furthermore, the total light transmittance of the transparent conductive film of the present invention is preferably 70% to 95%.

The transparent conductive film of the present invention is preferably formed by forming a transparent conductive film laminated with an indium-tin composite oxide on a transparent plastic film base material, and then performing the process in an oxygen-containing atmosphere at 80°C to 200°C. It takes 0.1 hour to 12 hours of heat treatment. If it is 80° C. or higher, it is easier to perform a process of slightly increasing the crystallinity in order to bring it into a semi-crystalline state, and the pen sliding durability is improved, which is preferable. If it is below 200°C, it is better to ensure the flatness of the transparent plastic film.

[Transparent plastic film base material]

The transparent plastic film base material used in the present invention is obtained by melt-extruding or solution-extruding organic polymers in the form of a film sheet, and then stretching, cooling, and heat-fixing in the length direction and/or width direction as needed. Diaphragms, as organic polymers, include: polyethylene, polypropylene, polyethylene terephthalate, polyethylene 2,6-naphthalate, polytrimethylene terephthalate, polyparaphenylene Butylene dicarboxylate, nylon 6, nylon 4, nylon 66, nylon 12, polyamide, polyamide, polyether ether ketone, polyether ether ketone, polycarbonate, polyacrylate, cellulose propylene acid ester, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyetherimide, polyphenylene sulfide, polyphenylene ether, polystyrene, syndiotactic polystyrene, norbornene-based polymers, etc.

Among these organic polymers, preferred are polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalate, and syndiotactic Polystyrene, norborneol Ethylene polymers, polycarbonate, polyacrylate, etc. In addition, these organic polymers can also copolymerize a small amount of monomers of other organic polymers, or be doped with other organic polymers.

The transparent plastic film base material used in the present invention can also be subjected to corona discharge treatment, glow discharge treatment, flame treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, ozone treatment, etc. Treatment and other surface activation treatments.

If a cured resin layer is coated on a transparent plastic film base material, the transparent conductive film can be strongly adhered to the cured resin layer, or the force applied to the transparent conductive film can be dispersed, so the transparency in the pen sliding test It is preferable because cracks, peeling, abrasion, etc. of the conductive film are suppressed, and cracks, peeling, etc. of the transparent conductive film in the pen heavy pressure test are suppressed. In addition, if the surface of the curable resin layer is concave and convex and a transparent conductive film is formed, the actual contact area between the transparent conductive film and the glass during the pen sliding test is reduced, so the sliding properties of the glass surface and the transparent conductive film are reduced. It becomes better and the pen sliding durability is improved, or the rollability of the film roller can be improved, or anti-Newton-ring (anti-Newton-ring) properties can be expected. However, if the unevenness is too large, the surface protrusions during the pen heavy pressure test will be reduced. The amount of deformation becomes large and cracks occur in the transparent conductive film, which is undesirable. Therefore, as the surface unevenness, the three-dimensional surface roughness SRa of the transparent conductive film is preferably 1 nm to 100 nm. The curable resin layer will be described in detail below.

In addition, the aforementioned curable resin preferably used in the present invention is not particularly limited as long as it is cured by energy application such as heating, ultraviolet irradiation, electron beam irradiation, etc. Examples include: silicone resin, acrylic resin Resin, methacrylic resin, epoxy resin, melamine resin, polyester resin, urethane resin, etc. From the viewpoint of productivity, it is preferable to use ultraviolet curable resin as the main component.

Examples of such ultraviolet curable resins include polyfunctional acrylate resins such as acrylic or methacrylic esters of polyols; hydroxyalkyl resins made of diisocyanates, polyols, and acrylic or methacrylic acid esters; Synthesize polyfunctional acrylic urethane resin, etc. If necessary, monofunctional monomers such as vinylpyrrolidone, methyl methacrylate, styrene, etc. can be added to these polyfunctional resins for copolymerization.

In addition, in order to improve the adhesion between the transparent conductive film and the curable resin layer, it is effective to treat the surface of the curable resin layer by the method described below. Specific methods include: a discharge treatment method of irradiating glow or corona discharge to increase carbonyl groups, carboxyl groups, and hydroxyl groups; a chemical treatment method of treating with acid or alkali to increase polar groups such as amine groups, hydroxyl groups, and carbonyl groups, etc. .

Ultraviolet curing resin is usually used by adding a photopolymerization initiator. As the photopolymerization initiator, well-known compounds that absorb ultraviolet rays and generate free radicals can be used without particular limitation. Examples of such photopolymerization initiators include various benzoins, phenyl ketones, and benzophenones. wait. The addition amount of the photopolymerization initiator is preferably 1 to 5 parts by mass per 100 parts by mass of the ultraviolet curable resin.

In addition, in the present invention, in the curable resin layer, it is preferable to use inorganic particles or organic particles in addition to the curable resin as the main component. By dispersing inorganic particles or organic particles in the curable resin, unevenness can be formed on the surface of the curable resin, thereby improving surface roughness in a wide area.

Examples of the inorganic particles include silica and the like. Examples of the organic particles include polyester resin, polyolefin resin, polystyrene resin, polyamide resin, and the like.

It is also preferable to use a resin incompatible with the curable resin in addition to the inorganic particles or organic particles in addition to the curable resin as the main component. By using a small amount in combination with the base The curable resin is a non-miscible resin, and phase separation can occur in the curable resin, causing the non-miscible resin to be dispersed in the form of particles. The dispersed particles of the immiscible resin can form unevenness on the surface of the hardened resin, thereby improving the surface roughness in a wide area.

Examples of the immiscible resin include polyester resin, polyolefin resin, polystyrene resin, polyamide resin, and the like.

As one example, the blending ratio of inorganic particles used in the curable resin layer is shown here. The inorganic particles are preferably 0.1 to 20 parts by mass per 100 parts by mass of the ultraviolet curable resin, more preferably 0.1 to 15 parts by mass, and particularly preferably 0.1 to 12 parts by mass.

If the blending amount of the aforementioned inorganic particles is 0.1 to 20 parts by mass per 100 parts by mass of the ultraviolet curable resin, the convex portions formed on the surface of the curable resin layer will not be too small, and three-dimensional surface roughness can be effectively imparted. , the amount of deformation of the surface protrusions during the pen heavy pressure test became smaller and the cracks produced in the transparent conductive film were suppressed. Furthermore, the transparent conductive film has slight surface protrusions, so the film rollability can also be maintained. Therefore it is better.

The aforementioned ultraviolet curable resin, photopolymerization initiator, and inorganic particles or organic particles or resins that are incompatible with the ultraviolet curable resin are respectively dissolved in a common solvent to prepare a coating liquid. The solvent used is not particularly limited. For example, the following solvents can be used alone or in mixture: alcohol solvents such as ethanol, isopropyl alcohol, etc.; ester solvents such as ethyl acetate, butyl acetate, etc.; Ether-based solvents such as butyl ether and ethylene glycol monoethyl ether; ketone-based solvents such as methyl isobutyl ketone, cyclohexanone, etc.; aromatic hydrocarbon-based solvents such as toluene, xylene, solvent naphtha, etc. Solvents, etc.

The concentration of the resin component in the coating liquid can be appropriately selected taking into account the viscosity corresponding to the coating method. For example, a combination of ultraviolet curing resin, photopolymerization initiator and high molecular weight polyester resin The proportion measured in the coating liquid is usually 20 mass% to 80 mass%. In addition, other well-known additives, such as silicone leveling agents, may be added to the coating liquid as needed.

In the present invention, the prepared coating liquid is coated on a transparent plastic film base material. The coating method is not particularly limited, and conventionally known methods such as bar coating, gravure coating, and reverse coating can be used.

The solvent of the applied coating liquid is evaporated and removed in the subsequent drying step. In this step, the high molecular weight polyester resin uniformly dissolved in the coating liquid becomes particles and precipitates in the ultraviolet curable resin. By drying the coating film and then irradiating the plastic film with ultraviolet rays, the ultraviolet curable resin is cross-linked and hardened to form a curable resin layer. In this hardening step, particles of high molecular weight polyester resin are fixed in the hard coat layer and protrusions are formed on the surface of the hardened resin layer to improve the surface roughness in a wide area.

In addition, the thickness of the curable resin layer is preferably in the range of 0.1 μm to 15 μm. More preferably, it is in the range of 0.5 to 10 μm, and particularly preferably in the range of 1 μm to 8 μm. When the thickness of the curable resin layer is 0.1 μm or more, it is preferable to form sufficient protrusions. On the other hand, if it is 15 μm or less, productivity is good and is preferable.

[Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these examples in any way. In addition, various measurement evaluations in the Examples were performed by the following methods.

(1) Total light transmittance

According to JIS-K7136-1:1997, the total light transmittance was measured using NDH-2000 manufactured by Nippon Denshoku Industries Co., Ltd.

(2)Surface resistance value

Measurement was performed using the four-terminal method in accordance with JIS-K7194:1994. The measuring machine uses Lotesta AX MCP-T370 manufactured by Mitsubishi Chemical Analytech Co., Ltd.

(3) Three-dimensional center surface average surface roughness SRa

The three-dimensional center plane average surface roughness SRa is specified by ISO (International Standard Organization; International Organization for Standardization) 25178, using a three-dimensional surface shape measuring device VertScan (manufactured by Mitsubishi Chemical System), R5500H-M100 (measurement conditions: wave (wave) mode, measuring wavelength 560nm, objective lens 10x)), obtain the three-dimensional center plane average surface roughness SRa. The number of measurements was set to 5, and the average value was calculated. Here, the nanometer (nm) unit is rounded off to the first decimal place.

(4)Granule size

Cut the film test piece laminated with the transparent conductive film layer into a size of 1 mm × 10 mm, and attach it to the upper surface of an appropriate resin block with the conductive film surface facing outward. After the attached article is trimmed, ultrathin slices almost parallel to the surface of the membrane are made using a conventional ultramicrotome technique.

The slice was observed using a transmission electron microscope (JEM-2010, manufactured by JEOL Corporation), and the surface portion of the conductive film without obvious damage was selected to take photos at an accelerating voltage of 200 kV and a direct magnification of 40,000 times.

Among the crystal grains observed under a transmission electron microscope, the longest part of all crystal grains was measured, and the average value of these measured values was taken as the crystal grain size. Here, an example related to the identification method of the longest part when measuring the longest part of a crystal grain is shown in FIG. 1 to FIG. 4 . That is, the longest part is determined by the length of the straight line that can best measure the particle diameter of each crystal grain.

(5) Thickness of transparent conductive film (film thickness)

The film test piece laminated with the transparent conductive film layer was cut into a size of 1 mm × 10 mm and embedded in epoxy resin for electron microscopy. The embedded article is fixed to the sample holder of the ultramicrotome, and a cross-sectional thin section parallel to the short side of the embedded sample is made. Then, a transmission electron microscope (manufactured by JEOL, JEM-2010) was used to take pictures of the parts of the sliced film that had no obvious damage, with an acceleration voltage of 200 kV, a bright field, and an observation magnification of 10,000 times. According to the obtained Calculate the film thickness from the photo.

(6) Pen sliding durability test

The transparent conductive film of the present invention is used as one of the panel plates, and an indium-tin composite oxide film (tin oxide content: 10 mass%) with a thickness of 20 nm is formed on a glass substrate by a sputtering method. The transparent conductive film is used as another panel board. The two panel plates were arranged with transparent conductive films facing each other through epoxy beads with a diameter of 30 μm, to produce a touch panel. Then, a load of 5.0N was applied to the pen made of polyacetal (top shape: 0.8mmR), and the touch panel was subjected to a linear sliding test of 180,000 back and forth times. In this test, a pen load was applied to the surface of the transparent conductive film of the present invention. At this time, the sliding distance is set to 30mm and the sliding speed is set to 180mm/s. After the sliding durability test, the on-resistance (the resistance value when the movable electrode (diaphragm electrode) comes into contact with the fixed electrode) is measured when the sliding part is pressed with a pen load of 0.8N. The on-resistance is preferably 10kΩ or less.

Furthermore, in the comparative examples, the film sheet in each comparative example was used instead of the transparent conductive film sheet of the present invention.

(7) Pen weight pressure test

A transparent conductive film obtained by cutting the transparent conductive film of the present invention into 50 mm × 50 mm is used as one of the panel plates, and an indium-tin layer with a thickness of 20 nm is formed on a glass substrate by sputtering. A transparent conductive film composed of a composite oxide film (tin oxide content: 10% by mass) is used as another A panel uses a board. The two panel plates are arranged with transparent conductive films facing each other through epoxy beads with a diameter of 30 μm, and a double-sided tape with a thickness adjusted to 120 μm is used to attach the panel plate on the diaphragm side. Use the panel with the glass side panel to make the touch panel. Use a polyacetal pen (top shape 0.8mmR) to apply a load of 35N at a position 2.0mm away from one end of the double-sided tape, and slide it in a straight line 10 times (5 times back and forth) parallel to the double-sided tape. In this test, a pen load was applied to the surface of the transparent conductive film of the present invention. At this time, the sliding distance is set to 30mm and the sliding speed is set to 20mm/s. Among them, slide in the position where there are no epoxy beads. After sliding, remove the transparent conductive film, measure the surface resistance at any five places on the sliding part (four-terminal method), and obtain the average value. When measuring the surface resistance, arrange the four terminals in a direction perpendicular to the sliding part so that the sliding part comes between the second terminal and the third terminal. Divide the average surface resistance value of the sliding part by the surface resistance value of the unsliding part (measured by the four-terminal method) to calculate the increase rate of the surface resistance value.

Furthermore, in the comparative examples, the films in each comparative example were used instead of the transparent conductive films of the present invention.

(8) Measurement of tin oxide content in the transparent conductive film

A sample (approximately 15 cm ² ) was cut out and placed in a quartz Erlenmeyer flask, 20 ml of 6 mol/l hydrochloric acid was added, and a diaphragm was sealed to prevent the acid from volatilizing. Leave it at room temperature for 9 days while shaking frequently to dissolve the transparent conductive film. The remaining film piece was taken out, and hydrochloric acid in which the transparent conductive film was dissolved was used as a measurement solution. In and Sn in the solution were determined by the calibration curve method using an ICP (Inductive Coupled Plasma) luminescence analyzer (manufacturer name: Rigaku, device model: CIROS-120 EOP). The measurement wavelength of each element is a wavelength with no interference and high sensitivity. In addition, the standard solution is diluted with commercially available standard solutions of In and Sn.

(9) Adhesion test

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

(10)Bending resistance test

Implemented in accordance with JIS K5600-5-1:1999. Among them, if no cracking or peeling occurs before the mandrel diameter reaches 13mm, no further bending resistance test will be performed, and all values will be recorded as 13mm.

The transparent plastic film base material used in the Examples and Comparative Examples is a biaxially aligned transparent PET (Polyethylene terephthalate; polyethylene terephthalate) film with easily adhesive layers on both sides (manufactured by Toyobo Co., Ltd., A4340, thickness Recorded in Table 1). To 100 parts by mass of an acrylic resin containing a photopolymerization initiator (Seikabeam (registered trademark) EXF-01J manufactured by Dainichi Seika Industrial Co., Ltd.) as a curable resin layer, silica was prepared in an amount described in Table 1 To the particles (Snowtex ZL manufactured by Nissan Chemical Co., Ltd.), a mixed solvent of toluene/MEK (mass ratio: 8/2) as a solvent was added so that the solid concentration became 50% by mass, and stirred to uniformly dissolve, and a coating liquid was prepared. (Hereinafter, this coating liquid will be referred to as coating liquid A). The prepared coating liquid was applied using a Mayer Rod so that the thickness of the coating film became 5 μm. After drying at 80° C. for 1 minute, ultraviolet rays (light quantity: 300 mJ/cm ² ) were irradiated using an ultraviolet irradiation device (UB042-5AM-W type manufactured by Eyegraphics) to harden the coating film. In addition, the hardening resin layer is provided on both sides of the transparent plastic base material.

[Example 1 to Example 8]

Each example level was implemented in the following manner based on the conditions shown in Table 1.

Put the diaphragm into the vacuum tank and evacuate it until it reaches 1.5×10 ^-4 Pa. Next, after introducing oxygen, argon gas as an inert gas and hydrogen gas as a hydrogen-containing gas were introduced at the concentrations listed in Table 1, and the total pressure was set to 0.6 Pa.

Apply power to a sintered target of indium-tin composite oxide or an indium oxide sintered target that does not contain tin oxide at a power density of 3W/ ^cm2 , and form a transparent conductive film by DC (Direct Current; DC) magnetron sputtering method. . The film thickness is controlled by changing the speed at which the diaphragm passes over the target. In addition, the ratio of the water pressure of the film-forming atmosphere to the inert gas during sputtering was measured using a gas analyzer (Transpector XPR3, manufactured by Inficon). In each example level, in order to adjust the ratio of the water pressure of the film-forming atmosphere to the inert gas during sputtering, as recorded in Table 1, the presence or absence of the impact step, the unevenness of the end face of the film roller, and the impact on the film were adjusted. The temperature of the temperature medium of the temperature regulating machine is controlled by the temperature of the moving central roller. The temperature corresponding to the middle point between the maximum value and the minimum value of the temperature from the start of film formation to the end of film formation on the film roll was recorded in Table 1 as the center value.

The film sheet on which the transparent conductive film was laminated was subjected to the heat treatment described in Table 1 and then measured. The measurement results are shown in Table 1.

[Comparative Example 1 to Comparative Example 8]

Under the conditions described in Table 1, a transparent conductive film was produced and evaluated in the same manner as in Example 1. Among them, Comparative Example 7 does not provide a curable resin layer. Among them, Comparative Example 8 was adjusted so that the thickness of the coating film of the curable resin layer became 20 μm. The results are shown in Table 2.

The amount of gas introduced in RF sputtering is the same as the amount of gas introduced into the vacuum device described in the Example.

The amount of gas introduced in RF sputtering is the same as the amount of gas introduced into the vacuum device described in the Example.

As described in Table 1A and Table 1B, the transparent conductive films described in Examples 1 to 8 are excellent in pen sliding durability and pen heavy pressure durability, and have both characteristics. However, as shown in Table 2, Comparative Examples 1 to 8 were unable to achieve both pen sliding durability and pen heavy pressure durability.

[Industrial Availability]

As described above, according to the present invention, a transparent conductive film excellent in pen sliding durability and pen heavy pressure durability can be produced. This transparent conductive film is extremely useful in applications such as resistive film type touch panels.

Claims (8)

A transparent conductive film, which is formed by layering a transparent conductive film of indium-tin composite oxide on at least one area of a transparent plastic film base material, and the transparent conductive film obtained by the following pen sliding durability test The on-resistance of the transparent conductive film of the transparent conductive film is less than 10kΩ, and the increase rate of the surface resistance value of the transparent conductive film of the transparent conductive film obtained from the following pen load test is less than 1.5; the aforementioned indium - The crystal grain size of the transparent conductive film of the tin composite oxide is 10 nm to 100 nm, the crystallinity of the transparent conductive film of the aforementioned indium-tin composite oxide is 20% to 80%, and the transparency of the aforementioned indium-tin composite oxide is The conductive film contains 0.5 mass% to 10 mass% tin oxide, and the thickness of the transparent conductive film of the above-mentioned indium-tin composite oxide is 10nm to 30nm; pen sliding durability test method: using the above-mentioned transparent conductive film as one of One panel plate, and a transparent conductive film composed of an indium-tin composite oxide film with a thickness of 20 nm and a tin oxide content of 10 mass% formed on a glass substrate by a sputtering method is used as the other panel plate ; Arrange the above two panel plates with transparent conductive films facing each other through epoxy beads with a diameter of 30 μm, and use double-sided tape with a thickness of 170 μm to attach the panel plate on the diaphragm side to the glass side The touch panel is made from a panel board; then, a load of 2.5N is applied to a polyacetal pen with a shape of 0.8mmR at the top, and the touch panel is subjected to a linear sliding test of 180,000 times; in the aforementioned straight line In the sliding test, a pen load is applied to the surface of the transparent conductive film; at this time, the sliding distance is set to 30mm and the sliding speed is set to 180mm/s; after the aforementioned sliding durability test, the pen load of 0.8N is used to press the sliding part. When the on-resistance is reached, the above-mentioned on-resistance is the resistance value when the diaphragm electrode, that is, the movable electrode is in contact with the fixed electrode; the pen weight test method: use the above-mentioned transparent conductive diaphragm cut into 50mm×50mm as the A panel plate is formed by sputtering on a glass substrate with a thickness of 20 nm and an oxidized A transparent conductive film composed of an indium-tin composite oxide film with a tin content of 10% by mass was used as another panel plate; the two panel plates were opposed to each other with a transparent conductive film with a diameter of 30 μm. The epoxy beads are configured, and a double-sided tape with a thickness adjusted to 120 μm is used to attach the panel plate on the diaphragm side and the panel plate on the glass side to make a touch panel; the shape of the top is 0.8 mmR polycondensation tape Apply a load of 35N to an aldehyde-made pen at a position 2.0 mm from one end of the double-sided tape, and slide it back and forth 5 times, that is, 10 times in a straight line, parallel to the double-sided tape. In the above test, the pen was applied to the side of the transparent conductive film. The load; at this time, the sliding distance is set to 30mm, and the sliding speed is set to 20mm/s; slide at a position where there are no epoxy beads; after sliding, remove the transparent conductive film, and use the four-terminal method to measure the sliding part Take the surface resistance at any five places and get the average value; when measuring the surface resistance, arrange the four terminals in a direction perpendicular to the sliding part, so that the sliding part comes between the second terminal and the third terminal; move the sliding part The average surface resistance value was divided by the surface resistance value of the non-sliding part measured by the four-terminal method to calculate the increase rate of the surface resistance value. The transparent conductive film according to claim 1, wherein the three-dimensional surface roughness SRa of the transparent conductive film of the indium-tin composite oxide is 1 nm to 100 nm. The transparent conductive film according to claim 1 or 2, wherein the transparent conductive film does not peel off even if the adhesion test (JIS K5600-5-6: 1999) is performed on the surface of the transparent conductive film. The bending resistance test (JIS K5600-5-1: 1999) is conducted on the transparent conductive film side of the indium-tin composite oxide of the flexible diaphragm. When the bending part is observed with a 10x magnifying glass, the diameter of the mandrel that causes cracking or peeling is less than 20mm. The transparent conductive film as described in claim 1 or 2, wherein the thickness of the transparent conductive film is 100 μm to 250 μm. The transparent conductive film as described in claim 3, wherein the thickness of the transparent conductive film is 100 μm to 250 μm. The transparent conductive film according to claim 1 or 2, wherein there is a hardening resin layer between the transparent conductive film of the indium-tin composite oxide and the transparent plastic film base material. The transparent conductive film according to claim 3, wherein there is a hardening resin layer between the transparent conductive film of the indium-tin composite oxide and the transparent plastic film base material. The transparent conductive film according to claim 4, wherein there is a hardening resin layer between the transparent conductive film of the indium-tin composite oxide and the transparent plastic film base material.

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