WO2023042843A1

WO2023042843A1 - Transparent conductive film

Info

Publication number: WO2023042843A1
Application number: PCT/JP2022/034346
Authority: WO
Inventors: 泰介鴉田; 望藤野
Original assignee: 日東電工株式会社
Priority date: 2021-09-17
Filing date: 2022-09-14
Publication date: 2023-03-23
Also published as: CN117099169A; JP7419609B2; JPWO2023042843A1

Abstract

A transparent conductive film (1) is provided with a base material (2) and an amorphous transparent conductive layer (3) in this order when observed toward one side in the thickness direction. The base material (2) has a second thermal shrinkage percentage HS2 that is smaller than a first thermal shrinkage percentage HS1 determined in a first direction orthogonal to the thickness direction and is a thermal shrinkage percentage determined in a second direction orthogonal to the thickness direction and the first direction. The second thermal shrinkage percentage HS2 of the base material (2) is 0.00% or less. The amorphous transparent conductive layer (3) contains a rare gas of an element having a larger atomic number than that of argon. The density of the amorphous transparent conductive layer (3) is more than 7.27 g/cm3.

Description

transparent conductive film

The present invention relates to transparent conductive films.

A transparent conductive film is known in which a substrate and a transparent conductive layer containing krypton are sequentially provided on one side in the thickness direction (see, for example, Patent Document 1 below).

In the transparent conductive film of Patent Document 1, the transparent conductive layer has a low specific resistance.

JP-A-05-334924

When the transparent conductive layer is amorphous, the amorphous transparent conductive layer is converted to a crystalline transparent conductive layer by heating (amorphous transparent conductive layer) depending on the application and purpose of the transparent conductive film. crystallization of the conductive layer). Since the transparent conductive layer is fragile compared to the base material, there is a problem that the transparent conductive layer is easily damaged by the above heating.

The inventors of the present invention have studied damage to the amorphous transparent conductive layer and obtained the following findings.

The amorphous transparent conductive layer containing krypton shrinks in the planar direction due to the heating described above. The plane direction is perpendicular to the thickness direction.

On the other hand, depending on the application and purpose of the transparent conductive film, it may be desirable to provide the transparent conductive film with a substrate that expands (expands) when heated.

In a transparent conductive film comprising the above-described substrate that can be stretched by heating and the above-described amorphous transparent conductive layer containing krypton, during the crystallization of the amorphous transparent conductive layer, the substrate is stretched while the non-crystalline conductive layer is stretched. The crystalline transparent conductive layer shrinks. Then, the contraction direction of the amorphous transparent conductive layer is opposite to the stretching direction of the base material, and a large stress is applied to the amorphous transparent conductive layer. Damage becomes obvious.

The inventors have found that damage to the amorphous transparent conductive layer can be suppressed by increasing the density of the amorphous transparent conductive layer to over 7.27 g/cm ³ .

The present invention provides a transparent conductive film in which damage to the amorphous transparent conductive layer is suppressed during crystallization of the amorphous transparent conductive layer while including a stretchable base material. I will provide a.

In the present invention (1), a substrate and an amorphous transparent conductive layer are provided in order toward one side in the thickness direction, and the substrate undergoes first heat shrinkage in a first direction perpendicular to the thickness direction. a second thermal contraction rate HS2 lower than the rate HS1, the second thermal contraction rate HS2 in a second direction orthogonal to the thickness direction and the first direction, and the second thermal contraction rate of the base material; HS2 is 0.00% or less, the amorphous transparent conductive layer contains a noble gas having an atomic number larger than that of argon, and the density of the amorphous transparent conductive layer is 7.27 g/cm ³ . including a transparent conductive film.

Since the second heat shrinkage rate HS2 of the base material is 0.00% or less, the transparent conductive film has a base material that can be stretched during the crystallization of the amorphous transparent conductive layer.

On the other hand, since the density of the amorphous transparent conductive layer exceeds 7.27 g/cm ³ , damage during crystallization of the amorphous transparent conductive layer can be suppressed.

In the present invention (2), the transparent conductive film has a third heat shrinkage rate HS3 in the first direction and a fourth heat shrinkage rate HS4 lower than the third heat shrinkage rate HS3, and 4 heat shrinkage rate HS4, wherein the fourth heat shrinkage rate HS4 is less than 0.04%, the transparent conductive film according to (1).

In the present invention (3), the value obtained by subtracting the second heat shrinkage rate HS2 of the substrate from the fourth heat shrinkage rate HS4 of the transparent conductive film (HS4-HS2) is 0.00% or more, It contains the transparent conductive film according to (2), which is 0.10% or less.

The transparent conductive film of the present invention includes a base material that can be stretched during the crystallization of the amorphous transparent conductive layer, while suppressing damage to the amorphous transparent conductive layer during the crystallization of the amorphous transparent conductive layer. be.

1 is a plan view of one embodiment of the transparent conductive film of the present invention; FIG. FIG. 2 is a cross-sectional view of the transparent conductive film in FIG. 1;

1. Transparent conductive film 1
A transparent conductive film 1 that is an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. This transparent conductive film 1 extends in a direction orthogonal to the thickness direction. The direction perpendicular to the thickness direction includes a first direction and a second direction. The second direction is orthogonal to the first direction. In this embodiment, the transparent conductive film 1 extends in the first direction. The transparent conductive film 1 may be a roll body (not shown) elongated in the first direction.

1.1 Layer Configuration of Transparent Conductive Film 1 The transparent conductive film 1 includes a substrate 2 and an amorphous transparent conductive layer 3 in order toward one side in the thickness direction. That is, in this transparent conductive film 1, the substrate 2 and the amorphous transparent conductive layer 3 are arranged in order toward one side in the thickness direction. In this embodiment, the transparent conductive film 1 includes only the base material 2 and the amorphous transparent conductive layer 3 .

1.2 Substrate 2
In this embodiment, the substrate 2 forms the other surface of the transparent conductive film 1 in the thickness direction. The base material 2 improves the mechanical strength of the transparent conductive film 1 . The base material 2 extends in the first direction.

1.2.1 First Thermal Shrinkage Rate HS1 and Second Thermal Shrinkage Rate HS2 of Base Material 2
The substrate 2 has a first thermal contraction rate HS1 in the first direction and a second thermal contraction rate HS2 in the second direction. The second heat shrinkage rate HS2 is lower than the first heat shrinkage rate HS1. The first direction in the first thermal contraction rate HS1 is the direction that gives the substrate 2 the highest thermal contraction rate. In this embodiment, the first direction is the longitudinal direction of the substrate 2 . The second direction is orthogonal to the first direction. The second direction is the width direction of the substrate 2 .

The first thermal shrinkage rate HS1 is the degree of shrinkage in the first direction after heating the base material 2 at 160°C for 1 hour. The first thermal contraction rate HS1 is obtained by the following formula.

First thermal contraction rate HS1=[length of base material 2 in first direction before heating−length of base material 2 in first direction after heating]/[length of base material 2 in first direction before heating ] x 100 (%)

The second thermal shrinkage rate HS2 is the degree of shrinkage in the second direction after heating the base material 2 at 160°C for 1 hour. The second thermal contraction rate HS2 is obtained by the following formula.

Second thermal shrinkage rate HS2 = [length of base material 2 in second direction before heating - length of base material 2 in second direction after heating]/[length of base material 2 in second direction before heating ] x 100 (%)

The first heat shrinkage rate HS1 is, for example, over 0.00%, preferably 0.10% or more, more preferably 0.20% or more, and still more preferably 0.30% or more. That is, in the present embodiment, the base material 2 shrinks in the first direction when heated. The upper limit of the first heat shrinkage rate HS1 is not limited. The upper limit of the first heat shrinkage rate HS1 is, for example, 2.00%, or, for example, 1.00%.

On the other hand, the second heat shrinkage rate HS2 is 0.00% or less. That is, the substrate 2 stretches or does not change dimensions (neither stretches nor shrinks) in the second direction when heated. Preferably, the substrate 2 stretches in the second direction when heated. Therefore, the transparent conductive film 1 can be preferably provided with the base material 2 that can be stretched in the second direction, depending on the application and purpose.

The second heat shrinkage rate HS2 is preferably -0.01% or less, more preferably -0.02% or less, even more preferably -0.03% or less, and particularly preferably -0.04% or less. , most preferably -0.05% or less.

The second heat shrinkage rate HS2 is, for example, -0.20% or more, preferably -0.10% or more.

The first heat shrinkage rate HS1 and the second heat shrinkage rate HS2 of the substrate 2 are obtained by removing the amorphous transparent conductive layer 3 from the transparent conductive film 1 and heating the remaining substrate 2. .

1.2.2 Layer Configuration of Base Material 2 In the present embodiment, the base material 2 includes a base sheet 21 and a functional layer 20 in order in the thickness direction. In this embodiment, the functional layer 20 is a multilayer. The functional layer 20 contacts one side and the other side of the base sheet 21 in the thickness direction. The functional layer 20 preferably comprises an optical adjustment layer 22 and a hard coat layer 23 . In this embodiment, the substrate 2 preferably includes an optical adjustment layer 22, a substrate sheet 21, and a hard coat layer 23 in order toward the other side in the thickness direction.

1.2.2.1 Base sheet 21
The base sheet 21 has flexibility. Examples of the base sheet 21 include a resin film. The resin in the resin film is not limited. Examples of resins include polyester resins, acrylic resins, olefin resins, polycarbonate resins, polyethersulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, cellulose resins, polystyrene resins, and norbornene resins. From the viewpoint of transparency and mechanical strength, the resin is preferably a polyester resin. Polyester resins include, for example, polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate, preferably PET.

The thickness of the base sheet 21 is preferably 1 µm or more, more preferably 10 µm or more, and even more preferably 30 µm or more. The thickness of the base sheet 21 is preferably 300 μm or less, more preferably 200 μm or less, still more preferably 150 μm or less, and particularly preferably 100 μm or less. The ratio of the thickness of the base sheet 21 to the thickness of the base 2 is, for example, 80% or more, preferably 95% or more, and is, for example, 100% or less, preferably 99% or less.

1.2.2.2 Optical adjustment layer 22
The optical adjustment layer 22 makes the pattern shape of the amorphous transparent conductive layer 3 (or the crystalline transparent conductive layer 30 described later) less visible. The optical adjustment layer 22 is arranged on one side of the base sheet 21 in the thickness direction. The optical adjustment layer 22 contacts one side of the base sheet 21 in the thickness direction. The optical adjustment layer 22 is, for example, a cured layer of a curable composition (first curable composition) containing a curable resin. Examples of curable resins include acrylic resins, urethane resins, amide resins, silicone resins, epoxy resins, and melamine resins. In this embodiment, the cured product layer preferably does not contain particles. The refractive index of the optical adjustment layer 22 is, for example, 1.40 or more, preferably 1.55 or more, and for example, 1.80 or less, preferably 1.70 or less. The thickness of the optical adjustment layer 22 is, for example, 5 nm or more, preferably 10 nm or more, and is, for example, 200 nm or less, preferably 100 nm or less. The ratio of the thickness of the optical adjustment layer 22 to the thickness of the substrate 2 is, for example, 0.01% or more, preferably 0.1% or more, and is, for example, 2% or less, preferably 1% or less. be.

1.2.2.3 Hard coat layer 23
The hard coat layer 23 makes it difficult for scratches to form on one surface of the amorphous transparent conductive layer 3 in the thickness direction when the transparent conductive film 1 is wound into a roll body. The hard coat layer 23 is arranged on the other side of the base sheet 21 in the thickness direction. The hard coat layer 23 contacts the other surface of the base sheet 21 in the thickness direction. The hard coat layer 23 is, for example, a cured layer of a curable composition (second curable composition) containing particles and a curable resin. Particles include, for example, oxide particles, glass particles, and organic particles. Examples of oxide particles include silica particles, alumina particles, titania particles, zirconia particles, calcium oxide particles, tin oxide particles, indium oxide particles, cadmium oxide particles, and antimony oxide particles. Materials for the organic particles include, for example, polymethylmethacrylate particles, polystyrene particles, polyurethane particles, acrylic-styrene copolymer particles, benzoguanamine particles, melamine particles, and polycarbonate particles. The curable resin includes the curable resin contained in the first curable composition. The thickness of the hard coat layer 23 is, for example, 0.1 μm or more, preferably 0.5 μm or more, and is, for example, 10 μm or less, preferably 3 μm or less. The ratio of the thickness of the hard coat layer 23 to the thickness of the base material 2 is, for example, 0.1% or more, preferably 2% or more, and is, for example, 10% or less, preferably 5% or less.

The thickness of the functional layer 20 is, for example, 0.15 μm or more and, for example, 3.5 μm or less. The thickness of the functional layer 20 is the total thickness of the optical adjustment layer 22 and hard coat layer 23 . The ratio of the thickness of the functional layer 20 to the thickness of the base sheet 21 is, for example, 0.01 or more, preferably 0.02 or more, and is, for example, 0.10 or less, preferably 0.05 or less. be. The ratio of the thickness of the functional layer 20 to the thickness of the base material 2 is, for example, 1% or more, preferably 2% or more, and is, for example, 10% or less, preferably 5% or less.

1.2.3 Thickness of base material 2 More preferably, it is 100 μm or less. The thickness of the base material 2 is the total thickness of the base material sheet 21 , the optical adjustment layer 22 and the hard coat layer 23 .

1.2.4 Physical properties other than heat shrinkage of the substrate 2 The total light transmittance of the substrate 2 is, for example, 75% or more, preferably 80% or more, more preferably 85% or more, and more preferably 90% or more. The upper limit of the total light transmittance of the substrate 2 is not limited. The upper limit of the total light transmittance of the substrate 2 is, for example, 100%. The total light transmittance of the substrate 2 is obtained based on JIS K 7375-2008. The total light transmittance of the following members is obtained based on the same method as above.

A commercially available product can be used for the base material 2 . Commercially available products include, for example, GF-50JBN (Mitsubishi Chemical Co.).

1.3 Amorphous transparent conductive layer 3
In this embodiment, the amorphous transparent conductive layer 3 forms one surface of the transparent conductive film 1 in the thickness direction. The amorphous transparent conductive layer 3 is arranged on one side of the substrate 2 in the thickness direction. The amorphous transparent conductive layer 3 is in contact with one surface of the substrate 2 in the thickness direction. In this embodiment, the amorphous transparent conductive layer 3 contacts one surface of the optical adjustment layer 22 (functional layer 20) in the thickness direction.

1.3.1 Thermal Shrinkage of Amorphous Transparent Conductive Layer 3 The thermal shrinkage of the amorphous transparent conductive layer 3 in the second direction exceeds, for example, 0.00%. That is, the amorphous transparent conductive layer 3 shrinks due to heating in the second direction, for example.

1.3.2 Density of Amorphous Transparent Conductive Layer 3 The density of the amorphous transparent conductive layer 3 exceeds 7.27 g/cm ³ .

On the other hand, if the density of the amorphous transparent conductive layer 3 is 7.27 g/cm ³ or less, the amorphous transparent conductive layer 3 is not sufficiently dense. , the amount of shrinkage of the transparent conductive layer 3 increases, and damage to the amorphous transparent conductive layer 3 cannot be suppressed. Specifically, the crystalline transparent conductive layer 30 is cracked.

On the other hand, in the present invention, since the density of the amorphous transparent conductive layer 3 exceeds 7.27 g/cm ³ , the amorphous transparent conductive layer 3 is sufficiently dense. In the crystallization of , the amount of shrinkage of the transparent conductive layer 3 is reduced, and as a result, damage to the amorphous transparent conductive layer 3 is suppressed. Specifically, it prevents the crystalline transparent conductive layer 30 from being cracked.

The density of the amorphous transparent conductive layer 3 is preferably 7.28 g/cm ³ or more, more preferably 7.30 g/cm ³ or more, still more preferably 7.35 g/cm ³ or more, and particularly preferably 7.38 g/cm ³ or more, most preferably 7.39 g/cm ³ or more, and more preferably 7.40 g/cm ³ or more.

The upper limit of the density of the amorphous transparent conductive layer 3 is not limited. The upper limit of the density of the amorphous transparent conductive layer 3 is, for example, 8.00 g/cm ³ , further 7.75 g/cm ³ .

The density of the amorphous transparent conductive layer 3 is adjusted, for example, by the method of forming the amorphous transparent conductive layer 3 and its conditions. When forming the amorphous transparent conductive layer 3 by sputtering, preferably, the pressure of the film forming gas is lowered and/or the film forming temperature is increased.

The density of the amorphous transparent conductive layer 3 is obtained using the X-ray reflectance method.

1.3.3 Material, Thickness and Other Physical Properties of Amorphous Transparent Conductive Layer 3 Examples of materials for the amorphous transparent conductive layer 3 include metal oxides. The metal oxide contains at least one metal selected from the group consisting of In, Sn, Zn, Ga, Sb, Nb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd and W . Specifically, the material of the amorphous transparent conductive layer 3 is preferably indium zinc composite oxide (IZO), indium gallium zinc composite oxide (IGZO), indium gallium composite oxide (IGO), indium tin Composite oxides (ITO) and antimony-tin composite oxides (ATO) are included, and indium-tin composite oxides (ITO) are preferred from the viewpoint of improving crack resistance.

The content of tin oxide (SnO ₂ ) in the indium tin composite oxide is, for example, 0.5% by mass or more, preferably 3% by mass or more, more preferably 6% by mass or more. , less than 50% by mass, preferably 25% by mass or less, more preferably 15% by mass or less.

The amorphous transparent conductive layer 3 contains a rare gas with an atomic number greater than that of argon. In this embodiment, the amorphous transparent conductive layer 3 preferably contains a noble gas with an atomic number greater than that of argon and does not contain argon.

In the first step described later, when the sputtering gas contains argon, a large amount of argon is taken into the amorphous transparent conductive layer 3 . In contrast, in the present embodiment in which the sputtering gas contains a rare gas with an atomic number greater than that of argon and does not contain argon, the amorphous transparent conductive layer 3 is suppressed from taking in a large amount of sputtering gas. Therefore, the amorphous transparent conductive layer 3 becomes dense, and as a result, the density of the amorphous transparent conductive layer 3 increases.

Specifically, the amorphous transparent conductive layer 3 is a metal oxide containing a rare gas with an atomic number greater than that of argon. That is, the amorphous transparent conductive layer 3 is a composition in which a metal oxide is mixed with a noble gas having an atomic number greater than that of argon.

Rare gases with atomic numbers greater than argon include, for example, krypton, xenon, and radon. These can be used alone or in combination. The noble gas having an atomic number greater than that of argon is preferably krypton and xenon, and more preferably krypton (Kr) from the viewpoint of obtaining low cost and excellent electrical conductivity.

The method for identifying noble gases is not limited. higher atomic number than argon in the amorphous transparent conductive layer 3, for example by Rutherford Backscattering Spectrometry, secondary ion mass spectrometry, laser resonance ionization mass spectrometry and/or X-ray fluorescence spectrometry Noble gases are identified.

The content of the rare gas having an atomic number greater than that of argon in the amorphous transparent conductive layer 3 is, for example, 0.0001 atom % or more, preferably 0.001 atom % or more, or, for example, 1.0 atom %. 0.7 atom% or less, more preferably 0.5 atom% or less, even more preferably 0.3 atom% or less, particularly preferably 0.2 atom% or less, most preferably 0.15 atom% % or less. If the content of the rare gas having an atomic number greater than that of argon in the amorphous transparent conductive layer 3 is within the above range, the amorphous transparent conductive layer 3 can be made dense.

The lower limit of the above content is a ratio corresponding to when the presence of a noble gas with an atomic number greater than that of argon can be confirmed by a fluorescent X-ray spectrometer, and is at least 0.0001 atomic % or more.

The thickness of the amorphous transparent conductive layer 3 is, for example, 15 nm or more, preferably 35 nm or more, more preferably 50 nm or more, even more preferably 75 nm or more, even more preferably 100 nm or more, particularly preferably 120 nm or more. is. The thickness of the amorphous transparent conductive layer 3 is, for example, 500 nm or less, preferably 300 nm or less, more preferably 200 nm or less.

The total light transmittance of the amorphous transparent conductive layer 3 is, for example, 75% or higher, preferably 80% or higher, more preferably 85% or higher, still more preferably 90% or higher. The upper limit of the total light transmittance of the amorphous transparent conductive layer 3 is not limited. The upper limit of the total light transmittance of the amorphous transparent conductive layer 3 is, for example, 100%.

The specific resistance of the amorphous transparent conductive layer 3 is, for example, 7.0×10 ⁻⁴ Ω·cm or less, preferably 6.0×10 ⁻⁴ Ω·cm or less, more preferably 5.5×10 Ω·cm or less. ⁻⁴ Ω·cm or less, more preferably 5.0×10 ⁻⁴ Ω·cm or less, and for example, 1×10 ⁻⁴ Ω·cm or more, preferably 2×10 ⁻⁴ Ω·cm above, and more preferably above 3.0×10 ⁻⁴ Ω·cm. A specific resistance is measured by the four-probe method.

1.4 Third Thermal Shrinkage Rate HS3 and Fourth Thermal Shrinkage Rate HS4 of Transparent Conductive Film 1
The transparent conductive film 1 has a third heat shrinkage rate HS3 in the first direction and a fourth heat shrinkage rate HS4 in the second direction. The fourth thermal contraction rate HS4 is lower than the third thermal contraction rate HS3.

Note that in the present embodiment, the first direction in the third thermal shrinkage rate HS3 is the direction that gives the transparent conductive film 1 the highest thermal shrinkage rate. In this embodiment, the first direction is the longitudinal direction of the transparent conductive film 1 .

In this embodiment, the third thermal shrinkage rate HS3 is the degree of shrinkage in the first direction after the transparent conductive film 1 is heated at 160° C. for 1 hour. The third heat shrinkage rate HS3 is obtained by the following formula.
Third heat shrinkage rate HS3 = [length of the transparent conductive film 1 in the first direction before heating - length of the transparent conductive film 1 in the first direction after heating] / [transparency in the first direction before heating Length of conductive film 1] × 100 (%)

In the present embodiment, the fourth thermal shrinkage rate HS4 is the degree of shrinkage in the second direction after heating the transparent conductive film 1 at 160°C for 1 hour. The fourth thermal contraction rate HS4 is obtained by the following formula.

Fourth heat shrinkage rate HS4 = [length of the transparent conductive film 1 in the second direction before heating - length of the transparent conductive film 1 in the second direction after heating] / [transparency in the second direction before heating Length of conductive film 1] × 100 (%)

The third heat shrinkage rate HS3 is, for example, over 0.00%, preferably 0.10%, more preferably 0.15% or more, and even more preferably 0.20% or more. That is, in the present embodiment, the transparent conductive film 1 shrinks in the first direction when heated. The upper limit of the third heat shrinkage rate HS3 is not limited. The upper limit of the third heat shrinkage rate HS3 is, for example, 2.00% or, for example, 1.00%.

The fourth heat shrinkage rate HS4 is, for example, 0.10% or less, preferably 0.05% or less, more preferably 0.04% or less, still more preferably 0.03% or less, particularly preferably 0 0.00% or less, most preferably less than 0.00%, more preferably -0.01% or less. The fourth heat shrinkage rate HS4 is, for example, -0.20% or more, preferably -0.10% or more. If the fourth thermal contraction rate HS4 is below the above upper limit and above the above lower limit, the difference (HS4-HS2) can be set to 0.00% or a small positive number, and thus the amorphous transparent conductive layer 3 Damage during crystallization can be effectively suppressed.

The fourth thermal contraction rate HS4 is adjusted, for example, by the method of forming the amorphous transparent conductive layer 3 and its conditions. When forming the amorphous transparent conductive layer 3 by sputtering, preferably, the pressure of the film forming gas is lowered and/or the film forming temperature is increased.

The value (HS4-HS2) obtained by subtracting the second heat shrinkage rate HS2 of the substrate 2 from the fourth heat shrinkage rate HS4 of the transparent conductive film 1 is, for example, 0.00% or more, preferably 0.00%. excess, more preferably 0.01% or more, and for example, 0.20% or less, preferably 0.10% or less, more preferably 0.07% or less, further preferably 0.05% % or less. If the above value (HS4-HS2) is equal to or more than the above lower limit and equal to or less than the upper limit, the amount of shrinkage of the amorphous transparent conductive layer 3 in the second direction during heating and the amount of shrinkage of the substrate 2 in the second direction during heating are The difference from the amount of stretching can be reduced, so that the stress applied to the amorphous transparent conductive layer 3 can be reduced, and damage to the amorphous transparent conductive layer 3 during crystallization can be effectively suppressed.

1.5 Thickness of Transparent Conductive Film 1 and Other Physical Properties It is preferably 200 μm or less, more preferably 100 μm or less.

The total light transmittance of the transparent conductive film 1 is, for example, 75% or more, preferably 80% or more, and is, for example, 100% or less.

1.6 Method for Manufacturing Transparent Conductive Film 1 In this method, for example, each layer is arranged by a roll-to-roll method. The MD direction and the TD direction in the roll-to-roll method correspond to the first direction and the second direction, respectively.

First, a long base material 2 is prepared. Specifically, each of the first curable composition and the second curable composition is applied to each of one surface and the other surface of the long base sheet 21 . After that, the curable resin in each of the first curable composition and the second curable composition is cured by heat or ultraviolet irradiation. Thereby, the optical adjustment layer 22 and the hard coat layer 23 are formed on one side and the other side of the base sheet 21, respectively. The base material 2 is prepared by this. The base material 2 has the above-described first thermal contraction rate HS1 and second thermal contraction rate HS2.

After that, the amorphous transparent conductive layer 3 is formed on one surface of the substrate 2 in the thickness direction. For example, sputtering, preferably reactive sputtering, is performed.

A sputtering apparatus is used for sputtering. The sputtering device includes a film-forming roll. A film-forming roll is equipped with a temperature control apparatus. The temperature adjusting device can adjust the temperature of the film forming roll. Since the film-forming roll can contact the base material 2, the temperature of the base material 2 can be adjusted.

In sputtering (preferably, reactive sputtering), the above metal oxide (sintered body) is used as a target. The surface temperature of the film-forming roll corresponds to the film-forming temperature in sputtering. The film formation temperature is, for example, 0° C. or higher, preferably 10° C. or higher, more preferably 20° C. or higher, still more preferably 30° C. or higher, particularly preferably 40° C. or higher, further preferably 50° C. or higher. is preferably 60° C. or higher. If the film-forming temperature is equal to or higher than the above-described lower limit, a (dense) amorphous transparent conductive layer 3 having a desired density can be formed.

The upper limit of the film formation temperature is, for example, 100°C, preferably 80°C. If the deposition temperature is equal to or lower than the upper limit described above, the crystallization speed of the amorphous transparent conductive layer 3 can be increased.

　Sputtering gases include noble gases with higher atomic numbers than argon. Noble gases having atomic numbers greater than argon include, for example, krypton, xenon, and radon, preferably krypton (Kr). The sputtering gas preferably does not contain argon. A sputtering gas may be mixed with a reactive gas. Reactive gases include, for example, oxygen. The ratio of the introduction amount of the reactive gas to the total introduction amount of the sputtering gas and the reactive gas is, for example, 0.1 flow % or more, preferably 0.5 flow % or more, and, for example, 5 flow % or less. , preferably 3 flow % or less.

The atmospheric pressure in the sputtering apparatus is, for example, 1.0 Pa or less, preferably 0.8 Pa or less, more preferably 0.5 Pa or less, still more preferably 0.3 Pa or less, and for example, 0.01 Pa or more. , preferably 0.05 Pa or more. If the atmospheric pressure in the sputtering apparatus is equal to or lower than the upper limit described above, the (dense) amorphous transparent conductive layer 3 having a desired density can be formed.

Thus, the transparent conductive film 1 including the substrate 2 and the amorphous transparent conductive layer 3 is manufactured.

After that, the amorphous transparent conductive layer 3 can be converted into a crystalline one depending on the application and purpose, and a crystalline transparent conductive layer 30 can be formed as indicated by the parenthesized symbols in FIG.

To convert the amorphous transparent conductive layer 3 to crystalline, the transparent conductive film 1 including the amorphous transparent conductive layer 3 is heated.

The heating temperature is, for example, 80° C. or higher, preferably 110° C. or higher, more preferably 130° C. or higher, particularly preferably 150° C. or higher, and for example, 200° C. or lower, preferably It is 180° C. or lower, more preferably 175° C. or lower, still more preferably 170° C. or lower. The heating time is, for example, 1 minute or longer, preferably 3 minutes or longer, more preferably 5 minutes or longer, and is, for example, 5 hours or shorter, preferably 3 hours or shorter, more preferably 2 hours or shorter. be. Heating is performed, for example, under an air atmosphere.

The crystallinity of the transparent conductive layer can be measured, for example, by immersing the transparent conductive layer in hydrochloric acid (20° C., concentration 5% by mass) for 15 minutes, then washing with water and drying. It is judged by measuring the terminal resistance between the degrees. In the amorphous transparent conductive layer 3 after immersion, washing with water, and drying, when the resistance between terminals (resistance between two terminals) for 15 mm is 10 kΩ or less, the transparent conductive layer is crystalline (that is, the crystalline transparent conductive layer 30), while the transparent conductive layer 3 is amorphous (that is, amorphous transparent conductive layer 3) when the above resistance exceeds 10 kΩ.

The density of the crystalline transparent conductive layer 30 is, for example, 6.50 g/cm ³ or more, preferably 6.60 g/cm ³ or more, more preferably 6.70 g/cm ³ or more, more preferably 6.80 g. /cm ³ or more, preferably 6.90 g/cm ³ or more, preferably 7.00 g/cm ³ or more, preferably 7.10 g/cm ³ or more, preferably 7.20 g/cm ³ or more. , or, for example, 8.0 g/cm ³ or less. If the density of the crystalline transparent conductive layer 30 is equal to or higher than the above lower limit, damage to the dense crystalline transparent conductive layer 30 is suppressed.

The total light transmittance of the crystalline transparent conductive layer 30 is, for example, 75% or higher, preferably 80% or higher, more preferably 85% or higher, and even more preferably 90% or higher. The upper limit of the total light transmittance of the crystalline transparent conductive layer 30 is not limited. The upper limit of the total light transmittance of the crystal transparent conductive layer 30 is, for example, 100%.

The specific resistance of the crystalline transparent conductive layer 30 is, for example, 5.0×10 ⁻⁴ Ω·cm or less, preferably 2.5×10 ⁻⁴ Ω·cm or less, more preferably 2.4×10 ⁻⁴ Ω·cm or less, more preferably 2.0×10 ⁻⁴ Ω·cm or less, and even more preferably 1.8×10 −4 Ω·cm or less, and for example, 0.1×10 ⁻⁴ Ω·cm or more, preferably 0.5×10 ⁻⁴ Ω·cm or more, more preferably 1.0×10 ⁻⁴ Ω·cm or more. A specific resistance is measured by the four-probe method.

1.7 Uses of Transparent Conductive Film 1 The transparent conductive film 1 is used for articles, for example. Articles include optical articles. More specifically, examples of articles include touch sensors, electromagnetic wave shields, light control elements, photoelectric conversion elements, heat ray control members, light-transmitting antenna members, light-transmitting heater members, image display devices, and lighting.

2. Effects of an Embodiment In this transparent conductive film 1, the second thermal shrinkage rate HS2 of the substrate 2 is 0.00% or less. It comprises a substrate 2 which can be stretched upon crystallization. Therefore, the transparent conductive film 1 can be suitably used in fields where the extension of the substrate 2 is allowed.

On the other hand, since the density of the amorphous transparent conductive layer 3 exceeds 7.27 g/cm ³ , damage during crystallization of the amorphous transparent conductive layer 3 can be suppressed.

Also, if the fourth thermal shrinkage rate HS4 of the transparent conductive film 1 is less than 0.00%, damage during crystallization of the amorphous transparent conductive layer 3 can be effectively suppressed.

Furthermore, the value obtained by subtracting the second heat shrinkage rate HS2 of the substrate 2 from the fourth heat shrinkage rate HS4 of the transparent conductive film 1 (HS4-HS2) is 0.00% or more and 0.10% or less. For example, the difference between the shrinkage amount of the transparent conductive film 1 in the second direction during heating in the crystallization of the amorphous transparent conductive layer 3 and the shrinkage amount of the substrate 2 in the second direction during heating can be reduced.
Therefore, the stress applied to the amorphous transparent conductive layer 3 can be reduced, and the damage during crystallization of the amorphous transparent conductive layer 3 can be effectively suppressed.

3. Modifications In each modification below, the same reference numerals are given to the same members and steps as in the above-described embodiment, and detailed description thereof will be omitted. Moreover, each modification can have the same effects as the one embodiment, unless otherwise specified. Furthermore, one embodiment and modifications can be combined as appropriate.

When the transparent conductive film 1 is not unwound from the roll body and the MD direction and the TD direction are unknown, the first direction is the direction in which the heat shrinkage rate is maximized by heating. The second direction is orthogonal to the first direction and the thickness direction. As a result, the first direction and the second direction are specified, and as a result, the third heat shrinkage rate HS3 and the fourth heat shrinkage rate HS4 of the transparent conductive film 1 and the first heat shrinkage rate HS1 and the second heat shrinkage rate HS1 of the base material 2 are specified. 2 the heat shrinkage rate HS2 is determined.

In a modified example, although not shown, the functional layer 20 is arranged on one side or the other side of the base sheet 21 in the thickness direction. The functional layer 20 may be either one of a hard coat layer and an optical adjustment layer. That is, one or more functional layers 20 are arranged on one side and/or the other side of the base sheet 21 in the thickness direction.

The present invention will be described more specifically below by showing examples. It should be noted that the present invention is by no means limited to the examples. In addition, specific numerical values such as the mixing ratio (content ratio), physical property values, and parameters used in the following description are the corresponding mixing ratios ( content ratio), physical properties, parameters, etc. can.

<Example 1>
A long base material 2 was prepared. Specifically, a base sheet 21 made of PET, an optical adjustment layer 22 arranged on one side of the base 2 in the thickness direction, and a hard coat layer 23 arranged on the other side of the base 2 in the thickness direction. A roll body of the base material 2 (manufactured by Mitsubishi Chemical Corporation, product name: GF-50JBN) with a thickness of 52 μm was prepared.

An amorphous transparent conductive layer 3 with a thickness of 145 nm was formed on one surface of the substrate 2 by reactive sputtering. In the reactive sputtering method, the roll body described above is set in a DC magnetron sputtering apparatus, and the amorphous transparent conductive layer 3 is continuously formed on one side of the base material 2 while unrolling the base material 2 from the roll body in the MD direction. The transparent conductive film 1 was wound on a roll body.

Sputtering conditions are as follows. A sintered body of indium oxide and tin oxide was used as a target. The tin oxide concentration in the sintered body was 10% by mass. A DC power supply was used to apply voltage to the target. The horizontal magnetic field strength on the target was set to 90 mT. The film formation temperature was 30°C. The film-forming temperature is the surface temperature of the film-forming roll, which is the same as the temperature of the substrate 2 . Further, the inside of the film forming chamber in the DC magnetron sputtering apparatus was evacuated until the final degree of vacuum in the film forming chamber reached 0.9×10 ⁻⁴ Pa, and the substrate 2 was degassed. After that, Kr as a sputtering gas and oxygen as a reactive gas were introduced into the film forming chamber, and the atmospheric pressure in the film forming chamber was set to 0.2 Pa. The ratio of the oxygen introduction amount to the total introduction amount of Kr and oxygen introduced into the film forming chamber was about 3.1 flow rate %.

<Examples 2 to 3 and Comparative Examples 1 to 2>
A transparent conductive film 1 was produced in the same manner as in Example 1. However, the pressure in the film forming chamber or the film forming temperature was changed as shown in Table 1.

<Evaluation>
The following items were evaluated for the transparent conductive film 1 of each example and each comparative example.

(1) Third Thermal Shrinkage Rate HS3 and Fourth Thermal Shrinkage Rate HS4 of Transparent Conductive Film 1
The transparent conductive film 1 immediately after production was cut into a size of 10 cm×10 cm (see the phantom lines in FIG. 1). The dimensions of the transparent conductive film 1 in the first direction (MD direction) and the second direction (TD direction) were measured with a planar biaxial device (QV ACCEL606-PRO manufactured by Mitutoyo).

After that, the transparent conductive film 1 was heated in a hot air oven at 160°C for 1 hour, and then allowed to stand until it returned to normal temperature. As a result, the amorphous transparent conductive layer 3 was converted to crystalline. After that, the dimensions of the first direction (MD direction) and the second direction (TD direction) of the transparent conductive film 1 were measured. Then, the third heat shrinkage rate HS3 and the fourth heat shrinkage rate HS4 of the transparent conductive film 1 were obtained. The results are listed in Table 1.

(2) First Thermal Shrinkage Rate HS1 and Second Thermal Shrinkage Rate HS2 of Base Material 2
A transparent conductive film 1 immediately after production was cut into a size of 10 cm×10 cm. After that, the amorphous transparent conductive layer 3 was removed from the transparent conductive film 1 . Specifically, the transparent conductive film 1 was immersed in hydrochloric acid (20° C., concentration 5% by mass) for 30 minutes, then washed with water and dried. Thus, a base material 2 was obtained.

After that, the dimensions of the substrate 2 in the first direction (MD direction) and the second direction (TD direction) were measured with a flat biaxial device (QV ACCEL606-PRO manufactured by Mitutoyo). After that, the substrate 2 was heated in a hot air oven at 160° C. for 1 hour, and then allowed to stand until it returned to normal temperature. As a result, the amorphous transparent conductive layer 3 was converted to crystalline. After that, the dimensions of the substrate 2 in the first direction (MD direction) and the second direction (TD direction) were measured. Then, the first thermal contraction rate HS1 and the second thermal contraction rate HS2 of the base material 2 were obtained. The results are listed in Table 1.

(3) Density of Amorphous Transparent Conductive Layer 3 The density of the amorphous transparent conductive layer 3 was determined using an X-ray reflectance method. Specifically, using a horizontal X-ray diffractometer (trade name "SmartLab", manufactured by Rigaku Corporation), analysis software (software name "SmartLab StudioII") "XRR-Vibration analysis/fitting" is used, Fitting between the X-ray reflectance curve obtained by the measurement and the theoretical profile was performed in the range of 2θ=0.5 to 1.0 deg. In the fitting, the quasi-Newton method and residual type |Δ(LogI)|(I: X-ray intensity) were used.

<Measurement conditions>
・Parallel beam optical arrangement ・Light source: CuKα ray (wavelength: 1.54059 Å)
・Incident side slit system: Solar slit OPEN
・Incident slit: 0.050 mm
・Light receiving side slit system: Solar slit 5.0deg
・Light receiving slit: 0.050 mm
・ Detector: Multidimensional pixel detector Hypix-3000
・Output: 45kV, 200mA
・Measurement speed: 0.1°/min ・Measurement range: 0° to 1.5°
・Scan axis: 2θ/ω
・Step interval: 0.008°
The results are listed in Table 1.

(4) Evaluation of crack resistance Each of (i) the first heating test and (ii) the second heating test was performed.

(i) First Heating Test The transparent conductive film 1 was unwound from the roll immediately after production and cut into a size of 50 cm×5 cm. Both short sides of the cut out transparent conductive film 1 were fixed with a heat-resistant tape, and heated in a hot air oven at 160° C. for 1 hour in the atmosphere.

After that, the transparent conductive film 1 was cut into 10 sheets. The size of each transparent conductive film 1 is 5 cm×5 cm. Of the ten transparent conductive films 1, the number of transparent conductive films 1 in which cracks were observed was counted. Cracks were observed under a microscope.

(ii) Second heating test The transparent conductive film 1 immediately after forming the amorphous transparent conductive layer 3 and before being wound on a roll body was continuously transported under vacuum without being wound. While being brought into contact with a heating roll (temperature: 160° C.), it was heated for about 5 minutes. After that, the transparent conductive film 1 was cut into a size of 50 cm×5 cm.

Then, the crack resistance was evaluated as follows.

Excellent: In both (i) the first heating test and (ii) the second heating test, cracks were observed in the crystalline transparent conductive layer 30 of 5 or less of the 10 transparent conductive films 1. .
Good: (i) In the first heating test, cracks were observed in the crystalline transparent conductive layers 30 of 5 or less of the 10 transparent conductive films 1 . On the other hand, (ii) in the second heating test, cracks were observed in the crystalline transparent conductive layers 30 of 6 or more of the 10 transparent conductive films 1 .
Poor: In both (i) the first heating test and (ii) the second heating test, cracks were observed in the crystalline transparent conductive layer 30 of 6 or more of the 10 transparent conductive films 1.

The results are listed in Table 1.

(5) [Confirmation of Kr in Amorphous Transparent Conductive Layer 3]
It was confirmed as follows that the amorphous transparent conductive layer 3 in each of Examples 1 to 3 and Comparative Examples 1 and 2 contained Kr.

First, using a scanning fluorescent X-ray analyzer (trade name "ZSX PrimusIV", manufactured by Rigaku), the fluorescent X-ray analysis measurement was repeated 5 times under the following measurement conditions, and the average value of each scanning angle was calculated. and an X-ray spectrum was created. Then, it was confirmed that the produced X-ray spectrum had a peak near the scanning angle of 28.2°.

<Measurement conditions>
Spectrum; Kr-KA
Measurement diameter: 30mm
Atmosphere: Vacuum Target: Rh
Tube voltage: 50kV
Tube current: 60mA
Primary filter: Ni40
Scanning angle (deg): 27.0 to 29.5
Step (deg): 0.020
Speed (deg/min): 0.75
Attenuator: 1/1
Slit: S2
Analysis crystal: LiF (200)
Detector: SC
PHA: 100-300

(6) [Confirmation of Ar in Amorphous Transparent Conductive Layer 3]
It was confirmed by Rutherford backscattering spectroscopy (RBS) that none of the amorphous transparent conductive layers 3 in Examples 1 to 3 and Comparative Examples 1 to 2 contained Ar.

Specifically, four elements, In + Sn (in Rutherford backscattering spectroscopy, it is difficult to separate In and Sn, so the sum of the two elements was evaluated), O, and Ar were measured as elements to be detected. to confirm the presence of Ar in the transparent conductive layer. The equipment used and the measurement conditions are as follows.

<Equipment used>
Pelletron 3SDH (manufactured by National Electrostatics Corporation)

<Measurement conditions>
Incident ions: 4He++
Incident energy: 2300 keV
Incident angle: 0deg
Scattering angle: 160deg
Sample current: 6nA
Beam diameter: 2mmφ
In-plane rotation: None Irradiation: 75 μC

Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an illustration and should not be construed as limiting. Variations of the invention that are obvious to those skilled in the art are included in the following claims.

The transparent conductive film is used for optical articles.

1 transparent conductive film 2 substrate 3 amorphous transparent conductive layer HS1 first heat shrinkage rate of substrate in first direction HS2 first heat shrinkage rate of substrate in second direction HS3 transparent conductive film in first direction First heat shrinkage rate HS4 of the first heat shrinkage rate of the transparent conductive film in the second direction

Claims

A substrate and an amorphous transparent conductive layer are provided in order toward one side in the thickness direction,
The base material has a second thermal contraction rate HS2 lower than the first thermal contraction rate HS1 in the first direction perpendicular to the thickness direction, and the second thermal contraction rate HS2 in the second direction perpendicular to the thickness direction and the first direction. 2 has a heat shrinkage rate HS2,
The second heat shrinkage rate HS2 of the base material is 0.00% or less,
The amorphous transparent conductive layer contains a rare gas having an atomic number greater than that of argon,
A transparent conductive film, wherein the density of the amorphous transparent conductive layer exceeds 7.27 g/cm 3 .
The transparent conductive film has a third heat shrinkage rate HS3 in the first direction and a fourth heat shrinkage rate HS4 lower than the third heat shrinkage rate HS3 and a fourth heat shrinkage rate HS4 in the second direction. have
The transparent conductive film according to claim 1, wherein the fourth heat shrinkage rate HS4 is less than 0.04%.
The value obtained by subtracting the second heat shrinkage rate HS2 of the substrate from the fourth heat shrinkage rate HS4 of the transparent conductive film (HS4-HS2) is 0.00% or more and 0.10% or less. 3. The transparent conductive film of claim 2.