JP7409872B2 - Light-transparent laminates, touch sensors and image display devices - Google Patents

Description

The present invention relates to a light-transmitting laminate, a touch sensor, and an image display device.

Conventionally, transparent conductive films are known to be used for optical applications such as touch sensors.

For example, a transparent conductor film has been proposed that has a transparent substrate, a first refractive index adjusting layer group, a transparent metal layer, and a second refractive index adjusting layer group in this order (for example, see Patent Document 1 below). . The first refractive index adjusting layer group includes a first high refractive index layer and an anti-sulfuration layer in this order. The second refractive index adjusting layer group includes a second high refractive index layer and a third high refractive index layer in this order.

Specifically, Patent Document 1 discloses a transparent substrate made of polyethylene terephthalate, a first high refractive index layer made of ZnSSiO ₂ , an anti-sulfuration layer made of IGZO, a transparent metal layer made of Ag, and a first layer made of IGZO. A transparent conductor film is disclosed that includes two high refractive index layers and a third high refractive index layer made of ITO in this order. In the transparent conductor film of Patent Document 1, the first refractive index adjusting layer group, the transparent metal layer, and the second refractive index adjusting layer group are all patterned into the same electrode shape in plan view. .

In the transparent conductor film described in Patent Document 1, discoloration caused by corrosion of Ag on the end face of the patterned transparent metal layer is suppressed by Zn contained in the anti-sulfuration layer and the second high refractive index layer. be able to.

Japanese Patent Application Publication No. 2016-81318

However, electrodes made of transparent conductive films are required to have a suppressed rate of change in resistance in a high temperature and high humidity atmosphere, that is, to have excellent heat and humidity resistance.

However, the transparent conductor film described in Patent Document 1 cannot satisfy the above requirements.

The present invention provides a light-transmitting laminate in which a light-transmitting conductive layer has excellent heat and moisture resistance while suppressing discoloration of a metal layer, and a touch sensor and an image display device equipped with the same.

The present invention (1) includes a light-transmitting member and a light-transmitting conductive layer in order toward one side in the thickness direction, and the light-transmitting conductive layer includes a first inorganic oxide layer, a metal layer, a second inorganic oxide layer in order toward one side in the thickness direction, and the second inorganic oxide layer has a first region containing indium and zinc and a second region not containing zinc in the thickness direction. The light-transmitting laminate includes a light-transmitting laminate which is arranged in order toward one side, and in which the number of moles of zinc in the first region is smaller than the number of moles of indium.

The present invention (2) comprises a light-transmitting conductive layer and a transfer base material in order toward one side in the thickness direction, and the light-transmitting conductive layer includes a first inorganic oxide layer, a metal layer, a second inorganic oxide layer in order toward one side in the thickness direction, and the second inorganic oxide layer has a first region containing indium and zinc and a second region not containing zinc in the thickness direction. The light-transmitting laminate includes a light-transmitting laminate which is arranged in order toward one side, and in which the number of moles of zinc in the first region is smaller than the number of moles of indium.

The present invention (3) includes the light-transmitting laminate according to (1) or (2), wherein the number of moles of zinc per 100 moles of indium in the first region is 10 moles or more and 30 moles or less. .

The present invention (4) provides the method according to any one of (1) to (3), wherein the ratio of the thickness of the second region to the thickness of the first region is 0.3 or more and 5 or less. Contains a light-transmitting laminate.

The present invention (5) includes the light-transmitting laminate according to any one of (1) to (4), wherein the second region contains indium and tin.

The present invention (6) includes the light-transmitting laminate according to any one of (1) to (5), wherein the second region contains indium-tin oxide.

The present invention (7) includes the light-transmitting laminate according to any one of (1) to (6), wherein the first region contains indium-zinc oxide.

The present invention (8) includes the light-transmitting laminate according to any one of (1) to (7), wherein the first inorganic oxide layer contains indium and zinc.

The present invention (9) includes the light-transmitting laminate according to any one of (1) to (8), wherein the first inorganic oxide layer contains indium-zinc oxide.

The present invention (10) includes the light-transmitting laminate according to any one of (1) to (9), wherein the metal layer contains silver.

The present invention (11) includes the light-transmitting laminate according to any one of (1) to (10), wherein the light-transmitting conductive layer is patterned.

The present invention (12) includes a touch sensor including the light-transmissive laminate described in (11).

The present invention (13) includes an image display device including the touch sensor described in (12).

In the light-transmissive laminate of the present invention, even if the metal layer is patterned and its end face is exposed and the material of the metal layer becomes corroded, the material contained in the first region corresponding to the metal layer is Zinc can suppress discoloration of the metal layer.

Further, in this light-transmitting laminate, the light-transmitting conductive layer has a first region containing indium and zinc and a second region not containing zinc in order toward one side in the thickness direction, and the second region does not contain zinc. The number of moles of zinc in one region is smaller than the number of moles of indium.

Therefore, the second region can suppress a change in resistance of the light-transmitting conductive layer due to a reaction between zinc and water contained in the first region.

As a result, in this light-transmitting laminate, discoloration of the metal layer can be suppressed, and the light-transmitting conductive layer has excellent heat and moisture resistance.

In the touch sensor and image display device of the present invention, discoloration of the patterned metal layer can be suppressed, and the patterned light-transmitting conductive layer has excellent heat and moisture resistance.

FIG. 1 shows a cross-sectional view of a light-transmissive film that is an embodiment of the light-transparent laminate of the present invention. 2A to 2C are cross-sectional views of the process of forming wiring by patterning the light-transparent conductive layer of the light-transparent film shown in FIG. FIG. 2B shows a step of etching and patterning the light-transmitting conductive layer exposed from the etching resist, and FIG. 2C shows a step of peeling off the etching resist and attaching the light-transmitting protection via the first pressure-sensitive adhesive member. The process of attaching a member to a light-transmitting film is shown. FIG. 3 shows a cross-sectional view of a modification of the light-transmissive film shown in FIG. 1 (an embodiment without a protective layer). FIG. 4 shows a cross-sectional view of a modified example of the light-transmitting film shown in FIG. 1 (an aspect in which the divisions of the first layer and the second layer are unclear). FIG. 5A shows a cross-sectional view of a light-transparent conductive layer with a transfer base material and a light-transparent base film with a protective layer in a modified example of the light-transparent laminate of the present invention. FIG. 5B shows a step of attaching a light-transparent conductive layer with a transfer base material to a light-transparent base film with a protective layer. 6A to 6E are a plan view and a cross-sectional view illustrating the evaluation of "change in wiring resistance" in the example, and FIG. 6B is a plan view of etching and patterning the light-transmitting conductive layer exposed from the etching resist, and peeling off the etching resist; FIG. 6C is a plan view of arranging the second pressure-sensitive adhesive member; A plan view of placing the paste, FIG. 6E, shows a cross-sectional view taken along line XX of FIG. 6D.

<One embodiment>
A light-transmitting film, which is an embodiment of the light-transmitting laminate of the present invention, will be described with reference to FIG. 1.

As shown in FIG. 1, the light-transmitting film 1 has one side and the other side facing each other in the thickness direction, and has a substantially film (sheet) shape extending in a plane direction perpendicular to the thickness direction.

The light-transmitting film 1 includes a light-transmitting base film 2, a protective layer 9, and a light-transmitting conductive layer 3 in this order toward one side in the thickness direction. Specifically, the light-transmitting film 1 includes a light-transmitting base film 2, a protective layer 9 disposed on one surface in the thickness direction, and a light-transmitting conductive layer 3 disposed on one surface in the thickness direction. Equipped with.

The light-transmitting base film 2 is a transparent base film, and supports the light-transmitting conductive layer 3 via the protective layer 9. The light-transmitting base film 2 has one side and the other side facing each other in the thickness direction, and has a film shape extending in the plane direction.

The material of the light-transmitting base film 2 is not particularly limited as long as it has light-transmitting properties (or transparency). Examples of materials for the light-transmissive base film 2 include resins (including polymers). Examples of the resin include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; (meth)acrylic resins (acrylic resins and/or methacrylic resins) such as polymethacrylate; for example, polyethylene, polypropylene; , olefin resins such as cycloolefin polymers (COP), e.g. polycarbonate resins, e.g. polyethersulfone resins, e.g. polyarylate resins, e.g. melamine resins, e.g. polyamide resins, e.g. polyimide resins, e.g. cellulose resins, Examples include polystyrene resins, such as norbornene resins. These resins can be used alone or in combination of two or more. Preferably, PET is used from the viewpoint of ensuring excellent mechanical properties. Preferably, COP is used from the viewpoint of ensuring excellent isotropy.

The total light transmittance (JIS K 7375-2008) of the light-transmitting base film 2 is, for example, 80% or more, preferably 85% or more.

The thickness of the light-transmitting base film 2 is not particularly limited, and is, for example, 2 μm or more, preferably 20 μm or more, and, for example, 300 μm or less, preferably 200 μm or less. The thickness of the light-transmitting base film 2 is measured using, for example, a film thickness meter.

The protective layer 9 is a light-transmissive protective layer (or a transparent protective layer), and protects one side of the light-transparent base film 2 in the thickness direction. Specifically, the protective layer 9 is disposed on one entire surface of the light-transmissive base film 2 in the thickness direction. More specifically, the protective layer 9 is in contact with one surface of the light-transmissive base film 2 in the thickness direction. The protective layer 9 has a film shape extending in the plane direction.

The material of the protective layer 9 is not particularly limited as long as it has light transmittance (or transparency) and can protect the light transmitting conductive layer 3. Examples of the material for the protective layer 9 include resins, such as curable resins such as ultraviolet curable resins and thermosetting resins, and thermoplastic resins, preferably. , curable resins, more preferably ultraviolet curable resins. Examples of the ultraviolet curable resin include acrylic resin and silicone resin. The property of the curable resin is preferably a cured product (C stage state), and the protective layer 9 is configured as a cured resin layer.

The total light transmittance (JIS K 7375-2008) of the protective layer 9 is, for example, 80% or more, preferably 85% or more.

The thickness of the protective layer 9 is, for example, 0.2 μm or more, preferably 1 μm or more, and is, for example, 50 μm or less, preferably 10 μm or less. The ratio of the thickness of the protective layer 9 to the thickness of the light-transmitting base film 2 is, for example, 0.01 or more, preferably 0.02 or more, and is, for example, 0.2 or less, preferably 0. .1 or less. The thickness of the protective layer 9 is measured by cross-sectional observation using a transmission electron microscope. The thickness of the light-transmitting conductive layer 3 (metal layer 5, first layer 7, and second layer 8, respectively), which will be described later, is measured by the same method as that for the protective layer 9.

The protective layer 9 and the light-transmitting base film 2 constitute a light-transmitting base film 10 with a protective layer, which is an example of a light-transmitting member including the protective layer 9 and the light-transmitting base film 2.

The light-transmitting conductive layer 3 is disposed on one side of the light-transmitting base film 2 in the thickness direction with a protective layer 9 interposed therebetween. Specifically, the light-transmitting conductive layer 3 is disposed on the entire surface of the protective layer 9 in the thickness direction. More specifically, the light-transmitting conductive layer 3 is in contact with one surface of the protective layer 9 in the thickness direction. The light-transmitting conductive layer 3 has a film shape extending in the plane direction.

Specifically, the light-transmitting conductive layer 3 includes a first inorganic oxide layer 4, a metal layer 5, and a second inorganic oxide layer 6 in this order toward one side in the thickness direction.

The first inorganic oxide layer 4 is located on the other side of the light-transmissive conductive layer 3 . The first inorganic oxide layer 4 is disposed on one entire surface of the protective layer 9 in the thickness direction. More specifically, the first inorganic oxide layer 4 is in contact with one surface of the protective layer 9 in the thickness direction. The first inorganic oxide layer 4 has a film shape extending in the plane direction.

The material of the first inorganic oxide layer 4 is not particularly limited as long as it is an inorganic oxide, and examples thereof include In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Pd, Examples include metal oxides containing at least one metal selected from the group consisting of W, preferably metal oxides containing at least two metals selected from the above group.

As a material for the first inorganic oxide layer 4, it ensures excellent light transmittance (transparency) and conductivity of the light-transmissive conductive layer 3, while suppressing discoloration caused by corrosion of the metal layer 5, which will be described next. In view of this, metal oxides containing In (indium) and Zn (zinc) are preferred, and indium-zinc oxide (IZO) is more preferred. Specific examples of IZO include a sintered body of indium oxide and zinc oxide.

In the case where the material of the first inorganic oxide layer 4 is a metal oxide containing In and Zn (specifically, IZO), the molar ratio of Zn to In is not particularly limited, and is preferably as described below. This is the same as the molar ratio in the first layer 7 (the number of moles of zinc per 100 moles of indium is, for example, 20 moles or more and 30 moles or less).

The thickness of the first inorganic oxide layer 4 is, for example, 3 nm or more, preferably 20 nm or more, more preferably 30 nm or more, and also, for example, 100 nm or less, preferably 60 nm or less, more preferably 50 nm or less. It is. The ratio of the thickness of the first inorganic oxide layer 4 to the thickness of the light-transmitting conductive layer 3 (thickness of the first inorganic oxide layer 4/thickness of the light-transmitting conductive layer 3) is, for example, 0.2 or more, It is preferably 0.4 or more, and is, for example, 0.6 or less, preferably 0.5 or less.

The metal layer 5 includes a first inorganic oxide layer 4 and a second inorganic oxide layer 6 (specifically, a first inorganic oxide layer 4 and a first layer 7, preferably a first inorganic oxide layer 4, Together with the first layer 7 and the second layer 8), it is a conductive layer that imparts conductivity to the light-transmissive conductive layer 3. Further, the metal layer 5 is also a resistivity-lowering layer that reduces the resistivity of the light-transmissive conductive layer 3.

The metal layer 5 is disposed over one entire surface of the first inorganic oxide layer 4 in the thickness direction. Specifically, the metal layer 5 is in contact with one surface of the first inorganic oxide layer 4 in the thickness direction. The metal layer 5 has a film shape extending in the plane direction.

The material of the metal layer 5 is not particularly limited, and includes, for example, Ti, Si, Nb, In, Sn, Au, Ag, Cu, Al, Co, Cr, Ni, Pb, Pd, Pt, Cu, Ge, Ru. , Nd, Mg, Ca, Na, W, Zr, Ta, and Hf, or an alloy containing two or more metals. The material for the metal layer 5 is preferably a metal or alloy different from the metal contained in the first inorganic oxide layer 4. The material for the metal layer 5 is more preferably a metal containing silver (including an alloy) from the viewpoint of reducing specific resistance, more preferably silver or a silver alloy, and particularly preferably silver. Examples include alloys.

Note that, as described later, metals containing silver are easily corroded depending on the environment, and therefore, the metal layer 5 is likely to be discolored. However, in this light-transmitting film 1, the zinc contained in the first layer 7 adjacent to the metal layer 5 (more specifically, the zinc contained preferably in the first inorganic oxide layer 4 and the first The above-mentioned discoloration can be suppressed by pseudo-corrosion protection (described in detail later) of zinc contained in layer 7.

The silver alloy contains silver as a main component and other metals as subcomponents, and its composition is not limited. Examples of the composition of the silver alloy include Ag-Pd alloy, Ag-Pd-Cu alloy, Ag-Pd-Cu-Ge alloy, Ag-Cu-Au alloy, Ag-Cu alloy, Ag-Cu-Sn alloy, Ag -Ru-Cu alloy, Ag-Ru-Au alloy, Ag-Pd alloy, Ag-Nd alloy, Ag-Mg alloy, Ag-Ca alloy, Ag-Na alloy, etc.

The content of silver in the silver alloy is, for example, 80% by mass or more, preferably 85% by mass or more, more preferably 90% by mass or more, still more preferably 95.0% by mass or more, and, for example, It is 99.9% by mass or less. The content ratio of other metals in the silver alloy is the remainder of the content ratio of silver described above.

The thickness of the metal layer 5 is, for example, 1 nm or more, preferably 5 nm or more, and is, for example, 30 nm or less, preferably 20 nm or less, more preferably 10 nm or less.
The ratio of the thickness of the metal layer 5 to the thickness of the first inorganic oxide layer 4 (thickness of the metal layer 5/thickness of the first inorganic oxide layer 4) is, for example, 0.05 or more, preferably 0.1. or more, and is also, for example, 0.5 or less, preferably 0.4 or less.

The second inorganic oxide layer 6 is disposed on one entire surface of the metal layer 5 in the thickness direction. Specifically, the second inorganic oxide layer 6 is in contact with one surface of the metal layer 5 in the thickness direction. The second inorganic oxide layer 6 has a film shape extending in the plane direction. More specifically, the second inorganic oxide layer 6 has one surface 21 and the other surface 22 facing each other in the thickness direction. One side 21 and the other side 22 are arranged at intervals in the thickness direction.

The other surface 22 of the second inorganic oxide layer 6 is in contact with one surface of the metal layer 5 in the thickness direction. On the other hand, one surface 21 of the second inorganic oxide layer 6 is exposed toward one side in the thickness direction.

The second inorganic oxide layer 6 has a first layer 7 divided into a first region 31 extending from the other surface 22 toward one side in the thickness direction, and a second region 31 extending from the one surface 21 toward the other side in the thickness direction. The second layer 8 is divided into 32 sections.

Specifically, the second inorganic oxide layer 6 includes only the first layer 7 located on the other side in the thickness direction (the other side region) and the second layer 8 located on the one side in the thickness direction (the one side region). has.

Further, in the second inorganic oxide layer 6, a first layer 7 and a second layer 8 are divided in order toward one side in the thickness direction, and specifically, the second inorganic oxide layer 6 is It does not include an intermediate layer formed between the layer 7 and the second layer 8. That is, the second inorganic oxide layer 6 includes only the first layer 7 and the second layer 8 in order toward one side in the thickness direction. In other words, the second inorganic oxide layer 6 has only the first region 31 and the second region 32 in order toward one side in the thickness direction.

The first layer 7 is disposed on one entire surface of the metal layer 5 in the thickness direction. Specifically, the first layer 7 is in contact with one surface of the metal layer 5 in the thickness direction. The first layer 7 has a film shape extending in the plane direction. The first layer 7 has substantially the same thickness over the surface direction. The first layer 7 includes the other surface 22 of the second inorganic oxide layer 6 . Note that one surface of the first layer 7 is in contact with the second layer 8.

The material of the first layer 7 contains In (indium) and Zn (zinc). Specifically, the material for the first layer 7 is selected from the viewpoint of suppressing discoloration caused by corrosion of the metal layer 5 while ensuring excellent light transmittance (transparency) and conductivity of the light-transmitting conductive layer 3. Examples include metal oxides containing In (indium) and Zn (zinc), preferably indium-zinc oxide (IZO). Specific examples of IZO include a sintered body of indium oxide and zinc oxide.

In the first layer 7, the number of moles of zinc is smaller than the number of moles of indium.

Conversely, if the number of moles of zinc in the first layer 7 is greater than the number of moles of indium, the zinc contained in the first layer 7 will be sufficiently inhibited from reacting with water and producing zinc hydroxide. Therefore, the change in resistance of the light-transmitting conductive layer 3 increases.

Specifically, in the first layer 7 (specifically, in a metal oxide containing In and Zn), the number of moles of zinc per 100 moles of indium is, for example, less than 100 moles, preferably 75 moles or less, More preferably 50 mol or less, still more preferably 45 mol or less, particularly preferably 40 mol or less, particularly preferably 35 mol or less, most preferably 30 mol or less, and, for example, 1 mol or more, Preferably, the amount is 5 mol or more, more preferably 10 mol or more, still more preferably 15 mol or more, particularly preferably 18 mol or more, particularly preferably 20 mol or more.

If the number of moles of zinc per 100 moles of indium is below the upper limit and above the lower limit described above, discoloration of the metal layer 5 due to corrosion can be effectively suppressed.

As for the number of moles of zinc per 100 moles of indium, when the first layer 7 is formed by sputtering, which will be described later, the number of moles of zinc in a target whose number of moles is known in advance can be directly applied.

The thickness of the first layer 7 is not particularly limited, and is, for example, 3 nm or more, preferably 8 nm or more, more preferably 10 nm or more, particularly preferably 12 nm or more, most preferably 15 nm or more, and, for example, , 100 nm or less, preferably 60 nm or less, more preferably 50 nm or less. The ratio of the thickness of the first layer 7 to the thickness of the second inorganic oxide layer 6 is, for example, 0.2 or more, preferably 0.3 or more, and is, for example, 0.9 or less, preferably, It is 0.8 or less, more preferably 0.7 or less, still more preferably 0.6 or less. Note that the thickness of the first layer 7 is adjusted so that the thickness ratio (thickness of the second layer 8/thickness of the first layer 7) with the second layer 8 (described later) is within a desired range.

The second layer 8 is located on one side of the light-transmissive conductive layer 3 . The second layer 8 is disposed on one entire surface of the first layer 7 in the thickness direction. Specifically, the second layer 8 is in contact with one surface of the first layer 7 in the thickness direction. The second layer 8 has a film shape extending in the plane direction. The second layer 8 has substantially the same thickness across the surface. The second layer 8 includes one side 21 of the second inorganic oxide layer 6 . Note that the other surface of the second layer 8 is in contact with the first layer 7.

The material of the second layer 8 does not contain zinc.

On the contrary, if the material of the second layer 8 contains zinc, the zinc of the second layer 8 will react with water together with the zinc contained in the first layer 7, and zinc hydroxide will be generated. This cannot be suppressed sufficiently, and as a result, the change in resistance of the light-transmitting conductive layer 3 increases.

Specifically, the material of the second layer 8 includes inorganic oxides that do not contain zinc, preferably In, Sn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Pd. , W, and at least one metal (excluding Zn) selected from the group consisting of W. Preferably, at least two metals (excluding Zn) selected from the above group are included. Examples include metal oxides containing

The material of the second layer 8 preferably contains In (indium) and Sn (tin), from the viewpoint of ensuring excellent light transmittance (transparency) and electrical conductivity of the light-transmissive conductive layer 3. Specific examples include metal oxides containing In (indium) and Sn (tin), and more preferably indium-tin oxide (ITO). Specific examples of ITO include a sintered body of indium oxide and tin oxide.

If the material of the second layer 8 is ITO, the rate of change in resistance of the light-transmitting conductive layer 3 due to zinc contained in the first layer 7 can be further suppressed.

The mass of tin oxide (SnO ₂ ) contained in ITO is, for example, 0.5% by mass or more, preferably 3% by mass or more, based on the total mass of tin oxide and indium oxide (In ₂ O ₃ ). , more preferably 6% by mass or more, further preferably 8% by mass or more, particularly preferably 10% by mass or more, and, for example, 35% by mass or less, preferably 20% by mass or less, more preferably , 15% by mass or less, more preferably 13% by mass or less. The mass content of indium oxide (In ₂ O ₃ ) is the remainder of the mass content of tin oxide (SnO ₂ ).

The thickness of the second layer 8 is, for example, 5 nm or more, preferably 8 nm or more, more preferably 10 nm or more, particularly preferably 12 nm or more, most preferably 15 nm or more, and, for example, 100 nm or less, preferably is 60 nm or less, more preferably 50 nm or less.

The ratio of the thickness of the second layer 8 to the thickness of the first layer 7 (thickness of the second layer 8/thickness of the first layer 7) is, for example, 0.1 or more, preferably 0.3 or more, more preferably is 0.6 or more, and is, for example, 10 or less, preferably 5 or less, more preferably 2.5 or less.

If the ratio of the thickness of the second layer 8 to the thickness of the first layer 7 is equal to or greater than the above-mentioned lower limit, the rate of change in resistance of the light-transmitting conductive layer 3 due to zinc contained in the first layer 7 can be further reduced. This can be further suppressed.

If the ratio of the thickness of the second layer 8 to the thickness of the first layer 7 is below the above-mentioned upper limit, corrosion of the metal layer 5 at the end face of the wiring 23 (on which the light-transmitting conductive layer 3 is patterned) will occur. The resulting discoloration can be effectively suppressed by Zn contained in the first layer 7.

The thickness of the second inorganic oxide layer 6 is the sum of the thickness of the first layer 7 and the thickness of the second layer 8, and is the distance between the other surface 22 and the one surface 21. The ratio of the thickness of the second inorganic oxide layer 6 to the thickness of the light-transmitting conductive layer 3 (thickness of the second inorganic oxide layer 6/thickness of the light-transmitting conductive layer 3) is, for example, 0.2 or more, It is preferably 0.4 or more, and is, for example, 0.6 or less, preferably 0.5 or less. Note that the thickness of the second inorganic oxide layer 6 is the same as the thickness of the first inorganic oxide layer 4.

The total light transmittance (JIS K 7375-2008) of the light-transmitting conductive layer 3 is, for example, 80% or more, preferably 85% or more.

The thickness of the light-transmitting conductive layer 3 is, for example, 40 nm or more, preferably 60 nm or more, and is, for example, 150 nm or less, preferably 100 nm or less.

Next, a method for manufacturing the light-transmitting film 1 will be explained.

In this method, for example, a roll-to-roll method is used.

In this method, first, a light-transmitting base film 2 is prepared, and then a protective layer 9, a first inorganic oxide layer 4, a metal layer 5, A first layer 7 and a second layer 8 are formed in this order. In addition, when the roll-to-roll method is used, a roll-shaped light-transmitting base film 2 (or a roll of light-transmitting base film 2) is prepared, and this is rolled out in the longitudinal direction. Meanwhile, each of the above-mentioned layers is formed in order, and then a roll-shaped light-transmitting film 1 (or a roll of light-transmitting film 1) is obtained.

The protective layer 9 is formed, for example, by a wet layer forming method such as coating. Specifically, it is formed by applying a resin composition containing the material of the protective layer 9 to one side of the light-transmitting base film 2 in the thickness direction, and then drying it.

The first inorganic oxide layer 4 is formed, for example, by a dry thin film forming method such as sputtering. Note that when forming the first inorganic oxide layer 4 by sputtering, the other surface of the light-transmitting base film 2 is cooled.

The method of forming the metal layer 5, the first layer 7, and the second layer 8 is the same as the method of forming the first inorganic oxide layer 4 described above.

Note that each of the protective layer 9, first inorganic oxide layer 4, metal layer 5, first layer 7, and second layer 8 can also be formed by a roll-to-roll method.

Note that the light-transmitting conductive layer 3 may or may not be crystallized. That is, the light-transmitting conductive layer 3 may be either a crystallized light-transmitting conductive layer or an amorphous light-transmitting conductive layer.

Thereafter, as shown in FIG. 2C, when the light-transmitting film 1 is included in the touch sensor 25, the light-transmitting conductive layer 3 of the light-transmitting film 1 is formed on the wiring 23 by patterning such as etching. be done.

Specifically, as shown in FIG. 2A, a dry film resist 15 (imaginary line) to an etching resist 11 is formed on one side 21 of the light-transmitting conductive layer 3, and then, as shown in FIG. 2B, etching resist 11 is formed. The light-transmitting conductive layer 3 exposed from the resist 11 is patterned by etching. Thereby, the wiring 23 is formed from the light-transmissive conductive layer 3. The layer structure of the wiring 23 is similar to that of the light-transmissive conductive layer 3. Thereafter, as shown in FIG. 2C, the etching resist 11 is peeled off from the wiring 23.

As shown by the imaginary line in FIG. 2C, the touch sensor 25 includes a light-transmissive film 1 having wiring 23, a first pressure-sensitive adhesive member 16, and a light-transparent protection member 26.

The first pressure-sensitive adhesive member 16 covers one side and a side surface of the wiring 23 and one side of the light-transmitting base film 2 exposed from the wiring 23. The first pressure-sensitive adhesive member 16 includes a first pressure-sensitive adhesive layer 24 made of a known pressure-sensitive adhesive.

The light-transmitting protection member 26 is pressure-sensitively bonded to the light-transmitting film 1 via the first pressure-sensitive adhesive member 16, and includes, for example, a cover glass extending in the surface direction.

This touch sensor 25 is provided in an image display device (not shown) or the like.

In this light-transmitting film 1, as shown in FIG. 2C, even if the end face of the metal layer 5 in the wiring 23 is exposed and the material of the wiring 23 is corroded, the metal layer 5 5 is in contact with the first pressure-sensitive adhesive member 16, and even if the light-transmitting film 1 on which the first pressure-sensitive adhesive member 16 is provided is exposed to a high temperature and high humidity environment, the first layer adjacent to the metal layer 5 Zinc contained in No. 7 can be preferentially corroded (sacrificially protected) over the above-mentioned materials (preferably silver). Therefore, discoloration caused by corrosion of the metal layer 5 can be suppressed.

Further, in this light-transmitting film 1, the light-transmitting conductive layer 3 is divided into a first layer 7 divided into a first region 31 containing indium and zinc, and a second region 32 not containing zinc. In the first layer 7 (first region 31), the number of moles of zinc is smaller than the number of moles of indium.

Here, when the zinc contained in the first layer 7 reacts with water, zinc hydroxide is generated. This zinc hydroxide is presumed to be a factor that increases the change in resistance of the light-transmitting conductive layer 3. Moreover, the increase in the change in resistance described above occurs even if the number of moles of zinc in the first layer 7 is greater than the number of moles of indium.

However, in the light-transmitting film 1 of this embodiment, the second layer 8 can suppress the formation of zinc hydroxide in the first layer 7, and therefore suppress the change in resistance of the light-transparent conductive layer 3. I can do it.

As a result, in this light-transmitting film 1, discoloration due to corrosion of the wiring 23 (patterned light-transmitting conductive layer 3) can be suppressed, and the heat and moisture resistance of the light-transmitting conductive layer 3 is excellent.

Further, in the touch sensor 25 and the image display device (not shown) including the touch sensor 25, discoloration due to corrosion of the wiring 23 can be suppressed, and the wiring 23 has excellent heat and moisture resistance.

Modification Next, a modification of one embodiment will be described. In each of the following modified examples, the same reference numerals are given to the same members and steps as in the above-described embodiment, and detailed explanation thereof will be omitted. Moreover, each modification can be combined as appropriate. Furthermore, each modification can produce the same effects as the one embodiment except as otherwise specified.

In one embodiment, as shown in FIG. 1, the light-transmissive film 1 includes a protective layer 9, but other layers than the protective layer 9, such as an optical adjustment layer, an anti-blocking layer, a hard coat layer, etc. It is possible to include a functional layer, and furthermore, for example, as shown in FIG. 3, the light-transmitting film 1 can be configured without the protective layer 9.

As shown in FIG. 3, the light-transmitting film 1 of this modification includes a light-transmitting base film 2 and a light-transmitting conductive layer 3 in order toward one side in the thickness direction. Specifically, the light-transmitting film 1 preferably includes only the light-transmitting base film 2 and the light-transmitting conductive layer 3.

The light-transmitting conductive layer 3 is directly disposed on one surface of the light-transmitting base film 2 in the thickness direction. Specifically, the first inorganic oxide layer 4 is in contact with one entire surface of the light-transmissive base film 2 in the thickness direction.

In one embodiment, the second inorganic oxide layer 6 includes a first layer 7 and a second layer 8, as shown in FIG. It is clearly observed by

On the other hand, the second inorganic oxide layer 6 does not clearly have the first layer 7 and the second layer 8 shown in FIG. It is possible to include only the first region 31 and the second region 32 in order toward one side in the thickness direction without clearly observing the interface between them.

The first region 31 has the other surface 22 . The material constituting the first region 31 is the same as the material of the first layer 7.

The second region 32 has one side 21 . The material constituting the second region 32 is the same as the material of the second layer 8.

The first region 31 and the second region 32 are identified by the presence or absence of zinc (Zn) by X-ray photoelectron spectroscopy.

In the second inorganic oxide layer 6, the region where Zn exists is the first region 31, and the region where Zn does not exist is the second region 32. Two regions 32 are identified and their thicknesses determined. Note that the thickness of the first region 31 is the same as the thickness of the first layer 7. The thickness of the second region 32 is similar to the thickness of the second layer 8. Furthermore, the ratio of the thickness of the second region 32 to the thickness of the first region 31 is similar to the ratio of the thickness of the second layer 8 to the thickness of the first layer 7 described above.

In the embodiment described above, the light-transmitting film 1 is included in the touch sensor 25 and used as a touch sensor, but for example, although not shown, it can also be used as an infrared reflecting member or an electromagnetic wave shielding member. .

As shown in FIG. 5A, the light-transmitting conductive layer 30 with a transfer base material, which is a modification of the light-transparent film 1 of one embodiment, has a thickness of Prepare in order toward one side.

The transparent conductive layer 3 is patterned in advance into the wiring 23, for example, as shown by the solid line in FIG. 5A.

The transfer base material 20 is described in, for example, Japanese Patent Application Publication No. 2019-31041. Note that the transfer base material 20 may or may not have light transmittance. Further, a peeling layer (not shown) may be provided on one side of the transfer base material 20 in the thickness direction.

As shown by the arrow in FIG. 5A and FIG. 5B, the light-transmitting conductive layer 30 with a transfer base material is attached to one side in the thickness direction of the light-transmitting base film 10 with a protective layer. At this time, the first inorganic oxide layer 4 of the light-transmitting conductive layer 3 comes into contact with one surface of the transfer base material 20 in the thickness direction.

Thereafter, as shown by the arrow in FIG. 5B, the transfer base material 20 is peeled off from the light-transmitting conductive layer 3. If a peeling layer is present, the peeling layer and the transfer base material 20 are peeled off from the light-transmitting conductive layer 3. In this way, the light-transmitting film 1 shown in FIG. 1 is manufactured.

In addition, as shown by the imaginary line in FIG. 5A, the light-transmitting conductive layer 3 that has not been patterned yet is patterned after being transferred to the light-transmitting base film 10 with a protective layer, as shown in FIG. 2C. Wiring 23 can also be formed.

In one embodiment, the second inorganic oxide layer 6 has only the first region 31 and the second region 32, but for example, although not shown, there may be a region of another component between them. Specifically, the second inorganic oxide layer 6 may include another layer between the first layer 7 and the second layer 8.

Examples and Comparative Examples are shown below to further specifically explain the present invention. Note that the present invention is not limited to the Examples and Comparative Examples. In addition, the specific numerical values such as compounding ratios (ratios), physical property values, parameters, etc. used in the following descriptions are the corresponding compounding ratios (ratios) described in the above "Details of Carrying Out the Invention". ), physical property values, parameters, etc., the upper limit (as "less than" or "less than")

(a defined numerical value) or a lower limit (a numerical value defined as "greater than" or "exceeding").

Example 1
(Preparation of light-transparent base film and formation of protective layer)
First, a light-transmitting base film 2 made of a long polyethylene terephthalate (PET) film was prepared in the form of a roll.

Next, a coating solution containing an ultraviolet curable resin made of acrylic resin is applied to one side in the thickness direction of the light-transmissive base film 2 and cured by ultraviolet irradiation to form a protective layer composed of a cured resin layer. 9 was formed. Thereby, as shown in FIG. 1, a light-transmissive base film 10 with a protective layer was obtained in the form of a roll, which included a light-transmissive base film 2 and a protective layer 9 in this order toward one side in the thickness direction.

(Formation of first inorganic oxide layer)
Next, the protective layer-attached light-transmitting base film 10 was placed in a vacuum sputtering device, left to stand, and evacuated until the atmospheric pressure before being conveyed reached 4×10 ⁻³ Pa (degassing treatment).

Next, the first inorganic oxide layer 4 made of IZO was formed on one side in the thickness direction of the protective layer 9 by sputtering while the protective layer-attached light-transmissive base film 10 was rolled out in the longitudinal direction.

Specifically, in a vacuum atmosphere of 0.2 Pa introducing Ar and O ₂ (flow rate ratio: Ar:O ₂ =100:1.4), indium oxide and oxide were mixed using a direct current (DC) power supply. An IZO target made of a sintered body with zinc (molar ratio In:Zn=100:21) was sputtered.

Note that when forming the first inorganic oxide layer 4 by sputtering, the other surface of the protective layer-attached light-transmitting base film 10 (specifically, the other surface of the light-transmitting base film 2) is -5 The protective layer-attached light-transmitting base film 2 was cooled by contacting it with a cooling roll at .degree.

(Formation of metal layer)
A metal layer 5 made of a silver alloy was formed on one surface of the first inorganic oxide layer 4 in the thickness direction by sputtering.

Specifically, an Ag alloy target (manufactured by Mitsubishi Materials Corporation, product number: "No. 317") was sputtered using a direct current (DC) power source as a power source in a vacuum atmosphere of 0.4 Pa with Ar introduced.

(Formation of first layer)
A first layer 7 made of IZO was formed on one side of the metal layer 5 in the thickness direction by sputtering.

Specifically, in a vacuum atmosphere of 0.2 Pa introducing Ar and O ₂ (flow rate ratio: Ar:O ₂ =100:1.4), indium oxide and oxide were mixed using a direct current (DC) power supply. An IZO target made of a sintered body with zinc (molar ratio In:Zn=100:21) was sputtered.

(Formation of second layer)
A second layer 8 made of ITO was formed on one surface of the first layer 7 in the thickness direction by sputtering.

Specifically _{, 88} mass% of An ITO target made of a sintered body of indium oxide and 12% by mass of tin oxide was sputtered.

As a result, a second inorganic oxide layer 6 consisting of a first layer 7 defined in a first region 31 and a second layer 8 defined in a second region 32 was formed.

As a result, a light-transmissive film 1 was obtained in which a protective layer 9, a first inorganic oxide layer 4, a metal layer 5, and a second inorganic oxide layer 6 were formed in this order on a light-transparent base film 2. Ta.

Examples 2 to 6
A light transmitting film 1 was obtained by processing in the same manner as in Example 1, except that the thicknesses of the first layer 7 and the second layer 8 were changed according to Table 1.

Comparative example 1
A light transmitting film 1 was obtained in the same manner as in Example 6 except that the first layer 7 was not formed. That is, the second inorganic oxide layer 6 was formed only from the second layer 8 made of ITO and containing no Zn. Note that the second layer 8 is in contact with one side of the metal layer 5.

Comparative example 2
A light transmitting film 1 was obtained in the same manner as in Example 6 except that the second layer 8 was not formed. That is, the second inorganic oxide layer 6 was formed only from the first layer 7 made of IZO containing In and Zn. Note that one surface of the first layer 7 is exposed toward one side in the thickness direction.

Comparative example 3
Except that the first layer 7 made of IGZO was formed by sputtering an IGZO target made of a sintered body of indium oxide, gallium oxide, and zinc oxide (molar ratio In:Ga:Zn=100:100:100). A light transmitting film 1 was obtained in the same manner as in Example 6.

(measurement)
Regarding the light transmitting film 1 of each Example and each Comparative Example, the following items were measured. The results are listed in Table 1.

(1) Thickness The thickness of each of the protective layer 9, first inorganic oxide layer 4, metal layer 5, first layer 7, and second layer 8 was measured using a transmission electron microscope (H-7650 manufactured by Hitachi, Ltd.). It was measured by cross-sectional observation.

Further, the thickness of the light-transmitting base film 2 was measured using a film thickness meter (digital dial gauge DG-205 manufactured by Peacock).

(2) Corrosivity of light-transmitting conductive layer (evaluation of discoloration caused by corrosion of wiring)
As shown by the imaginary line in FIG. 2A, a photosensitive dry film resist 15 (DFR) (trade name "RY3310", manufactured by Hitachi Chemical Co., Ltd.) is placed on one entire surface of the light-transmitting conductive layer 3 in the thickness direction, and then The dry film resist 15 was exposed to light through a photomask (not shown), and then developed to form an etching resist 11 having a pattern corresponding to the wiring 23, as shown by the solid line in FIG. 2A. . Thereafter, the light-transmitting conductive layer 3 exposed from the etching resist 11 was etched by immersing it in an etching solution heated to 40°C (ADEKA CHELMICA SET-500, manufactured by ADEKA Co., Ltd.) for 30 seconds, and washing with water. As shown in 2B, a patterned wiring 23 (patterned with the light-transmitting conductive layer 3) having a width of 100 μm was formed. Thereafter, the etching resist 11 was peeled off by immersing it in a 2.5% by mass sodium carbonate solution at 25° C. as shown by the solid line in FIG. 2C, followed by washing with water and drying.

Next, a first pressure-sensitive adhesive member 16 (manufactured by Nitto Denko Corporation, product number: "CS9904U") is provided with a first pressure-sensitive adhesive layer 24 (imaginary line) whose one side and the other side are covered with a separator (not shown). Next, after peeling one separator (not shown) from the other side of the first pressure-sensitive adhesive layer 24, the other side of the first pressure-sensitive adhesive layer 24 is attached to one side of the wiring 23 in the thickness direction and the other side of the first pressure-sensitive adhesive layer 24. They were bonded together so as to cover all the side surfaces and one surface of the protective layer 9 exposed from the wiring 23.

Subsequently, the light-transmitting film 1 to which the first pressure-sensitive adhesive member 16 (first pressure-sensitive adhesive layer 24) was attached was exposed for 500 hours in an environment of 85° C. and 85% relative humidity.

Thereafter, the corrosivity of the wiring 23 was evaluated by the following method.

The wiring 23 in the light-transmitting film 1 after being exposed in the above environment was observed with an optical microscope from one side in the thickness direction through the first pressure-sensitive adhesive layer 24 over a length of 2 cm. Corrosion from both end faces in the width direction was evaluated according to the following criteria.
◎: The total width of the width of the wiring 23 that changes in color from one end surface in the width direction toward the inside in the width direction and the width that changes in color from the other end surface in the width direction toward the inside in the width direction is 20 μm or less.
〇: The total width of the discoloration described above is more than 20 μm and less than 30 μm.
×: The total width of the discoloration described above exceeds 30 μm.

(3) Change in wiring resistance (heat and humidity resistance of light-transmitting conductive layer)
As shown in FIG. 6A, one surface 21 of the second inorganic oxide layer 6 (one surface in the thickness direction of the light-transmitting conductive layer 3) has a length (longitudinal length) of 60 mm and a width (width direction length). Etching resist (masking tape) 11 made of 6 mm polyimide was applied without bubbles or wrinkles, immersed in etching solution (ADEKA CHELMICA SET-500, manufactured by ADEKA Co., Ltd.) heated to 40°C for 30 seconds, and then washed with water. By doing so, the portion of the light-transmissive conductive layer 3 exposed from the etching resist 11 was etched. As a result, a patterned wiring 23 (patterned with the light-transmitting conductive layer 3) having a length of 60 mm and a width of 6 mm was formed. Thereafter, as shown in FIG. 6B, the etching resist 11 was peeled off, washed with water again, and dried.

Next, a second pressure-sensitive adhesive member 12 (manufactured by Nitto Denko Corporation, product number : "CS9904U") is prepared, and then, after peeling one separator (not shown) from the other side of the second pressure-sensitive adhesive layer 17, the other side of the second pressure-sensitive adhesive layer 17 is attached with the above-mentioned wiring. As shown in FIG. 6C, the light-transmitting base film 2 was pasted on one side in the thickness direction so as to cover the film 23. Specifically, the second pressure-sensitive adhesive member 12 was attached to the central portion of the wiring 23 in the longitudinal direction so that both ends 13 (10 mm long portions) of the wiring 23 were exposed from the second pressure-sensitive adhesive member 12. .

Next, as shown in FIGS. 6D and 6E, a silver paste 14 was applied to one side of each end portion 13 of the wiring 23 in the thickness direction. At this time, the silver paste 14 was applied only to one side 21 of both ends 13 so as not to reach the side surfaces (widthwise side and longitudinal side) of both ends 13. Thereafter, the silver paste 14 was heated at 130° C. for 30 minutes to dry it. In this way, a specimen for resistance measurement was prepared.

Subsequently, the resistance (initial resistance R ₀ ) between the silver paste 14 corresponding to both ends 13 was measured using a resistance value tester.

Thereafter, the resistance measurement specimen was exposed to an environment of 85° C. and 85% relative humidity for 500 hours, and the resistance (resistance R ₅₀₀ ) of this resistance measurement specimen was determined.

Then, the ratio (R ₅₀₀ /R ₀ ) of the resistance R ₅₀₀ after exposure to the initial resistance R ₀ was determined and evaluated in five grades (A to E) based on the following criteria.
A: 0.95≦R ₅₀₀ /R ₀ ≦1.05
B: 0.85≦ _R500 / _R0 <0.95, or 1.05< _R500 / _R0 ≦1.15
C: 0.80≦ _R500 / _R0 <0.85, or 1.15< _R500 / _R0 ≦1.20
D: 0.75≦ _R500 / _R0 <0.80, or 1.20< _R500 / _R0 ≦1.25
E: 0.75>R ₅₀₀ /R ₀ or 1.25<R ₅₀₀ /R ₀
In this evaluation, evaluation A means that the rate of change in resistance of the wiring 23 (light-transparent conductive layer 3) is small and the heat resistance and moisture resistance are the best, while evaluation E means that the wiring 23 (light-transparent conductive layer 3) The rate of change in resistance is large, meaning that it has the lowest heat and moisture resistance.

Note that although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be interpreted in a limiting manner. Variations of the invention that are obvious to those skilled in the relevant art are within the scope of the following claims.

The light-transmissive film is included in the touch sensor.

1 Light-transparent film 2 Light-transparent base film 3 Light-transparent conductive layer 4 First inorganic oxide layer 5 Metal layer 6 Second inorganic oxide layer 7 First layer 8 Second layer 10 Light-transparent with protective layer Base film 20 Transfer base material 25 Touch sensor 30 Light-transparent conductive layer with transfer base material 31 First area 32 Second area

Claims (13)

A light-transmitting member and a light-transmitting conductive layer are provided in order toward one side in the thickness direction,
The light-transmissive conductive layer is
comprising a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer in order toward one side in the thickness direction,
The second inorganic oxide layer is
a first region containing indium and zinc;
and a second region not containing zinc in order toward one side in the thickness direction,
A light-transmitting laminate, wherein the number of moles of zinc in the first region is smaller than the number of moles of indium. A light-transmitting conductive layer and a transfer base material are provided in order toward one side in the thickness direction,
The light-transmissive conductive layer is
comprising a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer in order toward one side in the thickness direction,
The second inorganic oxide layer is
a first region containing indium and zinc;
and a second region not containing zinc in order toward one side in the thickness direction,
A light-transmitting laminate, wherein the number of moles of zinc in the first region is smaller than the number of moles of indium. The light-transmitting laminate according to claim 1, wherein in the first region, the number of moles of zinc per 100 moles of indium is 10 moles or more and 30 moles or less. The light-transmitting laminate according to claim 1, wherein the ratio of the thickness of the second region to the thickness of the first region is 0.3 or more and 5 or less. The light-transmitting laminate according to claim 1, wherein the second region contains indium and tin. The light-transmitting laminate according to claim 1, wherein the second region contains indium-tin oxide. The light-transmitting laminate according to claim 1, wherein the first region contains indium-zinc oxide. The light-transmitting laminate according to claim 1, wherein the first inorganic oxide layer contains indium and zinc. The light-transmitting laminate according to claim 1, wherein the first inorganic oxide layer contains indium-zinc oxide. The light-transmitting laminate according to claim 1, wherein the metal layer contains silver. The light-transmitting laminate according to claim 1, wherein the light-transmitting conductive layer is patterned. A touch sensor comprising the light-transmissive laminate according to claim 11. An image display device comprising the touch sensor according to claim 12.

Images