WO2017170760A1 - Translucent film - Google Patents

Abstract

A translucent film is provided with a transparent base material and a light transmissive conductive layer in sequence. The light transmissive conductive layer is provided with a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer in sequence from the transparent base material. The first inorganic oxide layer does not contain crystal grains, and the second inorganic oxide layer does contain crystal grains.

Description

Light transmissive film

The present invention relates to a light transmissive film, and more particularly to a light transmissive film suitably used for optical applications.

Conventionally, it is known that a light transmissive film such as a transparent conductive film provided with a transparent conductive layer is used for optical applications such as a touch panel.

For example, a transparent conductive film has been proposed in which a conductive layer in which a transparent oxide thin film, a silver-based thin film, and a transparent oxide thin film are sequentially formed is laminated on a glass substrate (see, for example, Patent Document 1). In the transparent conductive film of Patent Document 1, the two transparent oxide conductive films are both formed from a mixed oxide containing indium oxide.

Japanese Patent Laid-Open No. 9-176837

In Patent Document 1, since a silver-based thin film is interposed between two transparent oxide conductive films, the resistance is excellent. In addition, since the conductive layer has a three-layer structure of a transparent oxide thin film, a silver-based thin film, and a transparent oxide thin film, visibility of the patterned conductive layer (wiring pattern) is suppressed when the conductive layer is patterned. be able to.

However, the silver-based thin film is vulnerable to wet heat, and even if the upper and lower surfaces of the silver-based thin film are covered with the transparent oxide thin film, the silver-based thin film is corroded and discolored. Therefore, the appearance of the transparent conductive film becomes poor.

An object of the present invention is to provide a light-transmitting film that is excellent in low resistance and transparency and excellent in wet heat durability.

This invention [1] is equipped with a transparent base material and a transparent conductive layer in order, and the transparent conductive layer includes a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer. In order from the transparent substrate, the first inorganic oxide layer does not contain crystal grains, and the second inorganic oxide layer contains a light-transmitting film containing crystal grains.

The present invention [2] includes the light transmissive film according to [1], wherein the metal layer is a silver layer or a silver alloy layer.

In the present invention [3], both the first inorganic oxide layer and the second inorganic oxide layer include the light transmissive film according to [1] or [2] containing indium oxide. .

The present invention [4] is any one of [1] to [3], wherein each of the first inorganic oxide layer and the second inorganic oxide layer contains an indium tin composite oxide. Includes light transmissive film.

The light transmission film according to any one of [1] to [4], wherein the second inorganic oxide layer is a semi-crystalline film having an amorphous part and a crystalline part. Is included.

The present invention [6] is the light according to any one of [1] to [5], wherein the second inorganic oxide layer contains crystal grains that do not penetrate the second inorganic oxide layer in the thickness direction. Includes permeable film.

The present invention [7] includes the light transmissive film according to any one of [1] to [6], wherein the light transmissive conductive layer has a pattern shape.

This invention [8] contains the light transmissive film as described in [7] further provided with the adhesive layer provided in the surface on the opposite side of the said light transmissive conductive layer with respect to the said transparent base material.

According to the light transmissive film of the present invention, it is excellent in low resistance and transparency, and is excellent in wet heat durability, so that appearance defects due to wet heat can be suppressed.

FIG. 1 shows a cross-sectional view of the light transmissive film of the first embodiment. 2A and 2B are partially enlarged views of the light transmissive film shown in FIG. 1, FIG. 2A is a schematic view when the second inorganic oxide layer is a complete crystal film, and FIG. The schematic diagram in case 2 inorganic oxide layers are semi-crystalline films | membranes is shown. FIG. 3 shows a cross-sectional view of the light transmissive film shown in FIG. 1 when the light transmissive conductive layer has a pattern shape. FIG. 4 shows a cross-sectional view of the light transmissive film of the second embodiment. FIG. 5 is a modification of the light transmissive film of the first embodiment, and shows a cross-sectional view of the light transmissive film in which the first inorganic oxide layer is directly disposed on the upper surface of the transparent substrate. FIG. 6 is a modification of the light transmissive film of the first embodiment, and shows a cross-sectional view of the light transmissive film in which the optical adjustment layer is interposed between the protective layer and the first inorganic oxide layer.

[First Embodiment]
With reference to FIG. 1, the light transmissive film 1 of 1st Embodiment of this invention is demonstrated.

In FIG. 1, the vertical direction of the paper is the vertical direction (thickness direction, first direction), the upper side of the paper is the upper side (one side in the thickness direction, the first direction), and the lower side of the paper is the lower side (thickness direction). The other side, the other side in the first direction). In FIG. 1, the left-right direction on the paper surface is the left-right direction (width direction, second direction orthogonal to the first direction), the left side on the paper surface is the left side (second side in the second direction), and the right side on the paper surface is the right side (the other side in the second direction). ). In FIG. 1, the paper thickness direction is the front-rear direction (a third direction orthogonal to the first direction and the second direction), the front side of the paper is the front side (the third direction one side), and the back side of the paper surface is the rear side (the third direction). The other side). Specifically, it conforms to the direction arrow in each figure.

1. Light transmissive film The light transmissive film 1 has a film shape (including a sheet shape) having a predetermined thickness, and extends in a predetermined direction (front and rear direction and left and right direction, that is, a surface direction) orthogonal to the thickness direction. A flat upper surface and a flat lower surface (two main surfaces). The light transmissive film 1 is, for example, one component such as a touch panel substrate, an infrared reflection substrate, or a light control panel provided in an optical device (for example, an image display device or a light control device). is not. That is, the light transmissive film 1 is a component for producing an optical device or the like, and does not include an image display element such as an LCD module or a light source such as an LED, and is a device that can be distributed and used industrially. is there. The light transmissive film 1 is a film that transmits visible light, and includes a transparent conductive film.

Specifically, as shown in FIG. 1, the light transmissive film 1 of the first embodiment includes a light transmissive laminate including a transparent substrate 2, a protective layer 3, and a light transmissive conductive layer 4 in order. It is a film. That is, the light transmissive film 1 includes a transparent substrate 2, a protective layer 3 disposed on the upper side of the transparent substrate 2, and a light transmissive conductive layer 4 disposed on the upper side of the protective layer 3. Preferably, the light transmissive film 1 includes only the transparent substrate 2, the protective layer 3, and the light transmissive conductive layer 4. Hereinafter, each layer will be described in detail.

2. Transparent substrate The transparent substrate 2 is the lowermost layer of the light transmissive film 1 and is a support material that ensures the mechanical strength of the light transmissive film 1. The transparent substrate 2 supports the light transmissive conductive layer 4 together with the protective layer 3.

The transparent substrate 2 is made of, for example, a polymer film.

The polymer film has transparency and flexibility. Examples of the material of the polymer film include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate, for example, (meth) acrylic resins (acrylic resin and / or methacrylic resin) such as polymethacrylate, And olefin resins such as polyethylene, polypropylene, and cycloolefin polymers such as polycarbonate resin, polyether sulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, polystyrene resin, norbornene resin, and the like. These polymer films can be used alone or in combination of two or more. From the viewpoint of transparency, heat resistance, mechanical properties and the like, preferably, olefin resin, polyester resin, and the like are mentioned, and more preferably, cycloolefin polymer, PET, and the like are mentioned.

The thickness of the transparent substrate 2 is, for example, 2 μm or more, preferably 20 μm or more, and for example, 300 μm or less, preferably 200 μm or less, more preferably 150 μm or less.

The transparent substrate 2 preferably contains a small amount of water from the viewpoint of maintaining the amorphous nature of the first inorganic oxide layer 5. That is, in the transparent substrate 2, the polymer film preferably contains water.

3. Protective layer The protective layer 3 is a scratch protective layer for making it difficult to cause scratches on the upper surface of the light-transmitting conductive layer 4 (that is, to obtain excellent scratch resistance). Further, as shown in FIG. 3, the protective layer 3 is different from the non-pattern part 9 and the pattern part 10 after the light-transmitting conductive layer 4 is formed in a pattern shape such as a wiring pattern in a later process. It is also an optical adjustment layer that adjusts the optical properties of the light transmissive film 1 so as not to be recognized (that is, to suppress the visual recognition of the wiring pattern).

The protective layer 3 has a film shape (including a sheet shape), and is disposed on the entire upper surface of the transparent substrate 2 so as to be in contact with the upper surface of the transparent substrate 2.

The protective layer 3 is formed from a resin composition.

Resin composition contains, for example, resin, particles and the like. The resin composition preferably contains a resin, and more preferably consists only of a resin.

Examples of the resin include a curable resin, a thermoplastic resin (for example, a polyolefin resin), and preferably a curable resin.

Examples of the curable resin include an active energy ray-curable resin that is cured by irradiation with active energy rays (specifically, ultraviolet rays, electron beams, etc.), for example, a thermosetting resin that is cured by heating, and the like. Preferably, an active energy ray curable resin is used.

Examples of the active energy ray-curable resin include a polymer having a functional group having a polymerizable carbon-carbon double bond in the molecule. Examples of such a functional group include a vinyl group and a (meth) acryloyl group (methacryloyl group and / or acryloyl group).

Examples of the active energy ray-curable resin include (meth) acrylic resin (acrylic resin and / or methacrylic resin) containing a functional group in the side chain.

These resins can be used alone or in combination of two or more.

Examples of the particles include inorganic particles and organic particles. Examples of the inorganic particles include silica particles, for example, metal oxide particles made of zirconium oxide, titanium oxide, and the like, for example, carbonate particles such as calcium carbonate. Examples of the organic particles include crosslinked acrylic resin particles.

The thickness of the protective layer 3 is, for example, 0.1 μm or more, preferably 1 μm or more, and for example, 10 μm or less, preferably 5 μm or less. The thickness of the protective layer 3 is measured by, for example, cross-sectional observation with a transmission electron microscope (TEM).

4). Light-transmissive conductive layer The light-transmissive conductive layer 4 is a conductive layer, and as shown in FIG. 3, is a conductive layer that is formed in a wiring pattern in a later step to form the pattern portion 10. . The light transmissive conductive layer 4 is also a transparent conductive layer.

As shown in FIG. 1, the light transmissive conductive layer 4 is the uppermost layer of the light transmissive film 1 and has a film shape (including a sheet shape). It arrange | positions so that the upper surface of the layer 3 may be contacted.

The light transmissive conductive layer 4 includes a first inorganic oxide layer 5, a metal layer 6, and a second inorganic oxide layer 7 in order. That is, the light transmissive conductive layer 4 includes a first inorganic oxide layer 5 disposed above the protective layer 3, a metal layer 6 disposed above the first inorganic oxide layer 5, and the metal layer 6. And a second inorganic oxide layer 7 disposed on the upper side. The light transmissive conductive layer 4 is preferably composed of only the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7.

5. First inorganic oxide layer In the first inorganic oxide layer 5, hydrogen derived from water contained in the transparent substrate 2 and carbon derived from organic substances contained in the protective layer 3 enter the metal layer 6. This is a barrier layer that prevents this. Furthermore, the 1st inorganic oxide layer 5 suppresses the visible light reflectance of the metal layer 6 with the 2nd inorganic oxide layer 7 mentioned later, and improves the visible light transmittance of the transparent conductive layer 4 It is also an optical adjustment layer. The first inorganic oxide layer 5 is preferably a conductive layer that imparts conductivity to the light-transmissive conductive layer 4 together with the metal layer 6 described later, and more preferably a transparent conductive layer.

The first inorganic oxide layer 5 is the lowermost layer in the light transmissive conductive layer 4 and has a film shape (including a sheet shape). The first inorganic oxide layer 5 is formed on the entire upper surface of the protective layer 3 and on the upper surface of the protective layer 3. It is arranged to come into contact.

As the inorganic oxide forming the first inorganic oxide layer 5, for example, In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W, Fe, Examples thereof include metal oxides formed from at least one metal selected from the group consisting of Pb, Ni, Nb, and Cr. If necessary, the metal oxide can be further doped with a metal atom shown in the above group.

The inorganic oxide is preferably an oxide containing indium oxide (indium oxide-containing oxide) from the viewpoint of reducing the surface resistance value and ensuring excellent transparency.

The oxide containing indium oxide may contain only indium (In) as a metal element, or may contain (semi) metal elements other than indium (In). In the indium oxide-containing oxide, the main metal element is preferably indium (In). The indium oxide-containing oxide whose main metal element is indium has an excellent barrier function and easily suppresses corrosion of the metal layer 6 due to the influence of water or the like.

The indium oxide-containing oxide can further improve conductivity, transparency, and durability by containing one or more (semi) metal elements as impurity elements. The ratio of the number of contained impurity metal elements to the number of main metal element In atoms in the first inorganic oxide layer 5 (the number of impurity metal element atoms / the number of In atoms) is, for example, less than 0.50, Preferably, it is 0.40 or less, more preferably 0.30 or less, and further preferably 0.20 or less. For example, 0.01 or more, preferably 0.05 or more, more preferably 0. 10 or more. Thereby, the inorganic oxide layer excellent in transparency and wet heat durability is obtained.

Specific examples of the indium oxide-containing oxide include, for example, indium zinc composite oxide (IZO), indium gallium composite oxide (IGO), indium gallium zinc composite oxide (IGZO), and indium tin composite oxide (ITO). More preferably, indium tin composite oxide (ITO) is used. “ITO” in this specification may be a complex oxide containing at least indium (In) and tin (Sn), and may contain additional components other than these. As an additional component, metal elements other than In and Sn are mentioned, for example, For example, the metal element shown by the said group, and these combination are mentioned. The content of the additional component is not particularly limited, but is, for example, 5% by mass or less.

The content of tin oxide (SnO ₂ ) contained in ITO is, for example, 0.5% by mass or more, preferably 3% by mass or more with respect to the total amount of tin oxide and indium oxide (In ₂ O ₃ ). More preferably, it is 6% by mass or more, more 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, and more preferably 13% by mass or less. The content of indium oxide (In ₂ O ₃ ) is the remainder of the content of tin oxide (SnO ₂ ). By adjusting the content of tin oxide (SnO ₂ ) contained in ITO within the above range, the crystallinity of the ITO film can be adjusted. In particular, by increasing the content of tin oxide in the ITO film, complete crystallization of the ITO film due to heating can be suppressed and a semi-crystalline film can be obtained.

The atomic number ratio Sn / In of Sn to In contained in ITO is, for example, 0.004 or more, preferably 0.02 or more, more preferably 0.03 or more, and further preferably 0.04 or more. Particularly preferably, it is 0.05 or more, and for example, 0.4 or less, preferably 0.3 or less, more preferably 0.2 or less, and still more preferably 0.10 or less. The atomic ratio of Sn to In can be determined by X-ray photoelectron spectroscopy (ESCA: Electron Spectroscopy for Chemical Analysis). By setting the atomic ratio of In and Sn within the above range, it is easy to obtain a film quality excellent in environmental reliability.

The first inorganic oxide layer 5 does not contain crystal grains. That is, the first inorganic oxide layer 5 is amorphous. Thereby, the wettability of the surface of the 1st inorganic oxide layer 5 can be improved, and the metal layer 6 mentioned later can be more reliably formed into a thin and uniform film on the upper surface of the first inorganic oxide layer 5. Therefore, the film quality of the light transmissive conductive layer 4 can be improved, and the wet heat durability can be improved.

In the present invention, “does not contain crystal grains” means that the first inorganic oxide layer 5 is observed by using a cross-sectional TEM image at 200,000 times in a plane direction (left-right direction) perpendicular to the thickness direction. Or, in the range of 500 nm, the crystal grains are not observed.

The content ratio of the inorganic oxide in the first inorganic oxide layer 5 is, for example, 95% by mass or more, preferably 98% by mass or more, more preferably 99% by mass or more, and for example, 100% by mass or less. It is.

The thickness T1 of the first inorganic oxide layer 5 is, for example, 5 nm or more, preferably 20 nm or more, more preferably 30 nm or more, and for example, 100 nm or less, preferably 60 nm or less, more preferably 50 nm. It is as follows. When the thickness T1 of the first inorganic oxide layer 5 is in the above range, the visible light transmittance of the light transmissive conductive layer 4 can be easily adjusted to a high level. The thickness T1 of the first inorganic oxide layer 5 is measured by, for example, cross-sectional observation with a transmission electron microscope (TEM).

6). Metal Layer The metal layer 6 is a conductive layer that imparts conductivity to the light transmissive conductive layer 4 together with the first inorganic oxide layer 5 and the second inorganic oxide layer 7. The metal layer 6 is also a low resistance layer that reduces the surface resistance value of the light transmissive conductive layer 4. The metal layer 6 is also preferably an infrared reflecting layer for imparting a high infrared reflectance (particularly, an average reflectance of near infrared rays).

The metal layer 6 has a film shape (including a sheet shape), and is disposed on the upper surface of the first inorganic oxide layer 5 so as to be in contact with the upper surface of the first inorganic oxide layer 5.

The metal forming the metal layer 6 is not limited as long as it has a low surface resistance. For example, Ti, Si, Nb, In, Zn, Sn, Au, Ag, Cu, Al, Co, Cr, Ni, It consists of one metal selected from the group consisting of Pb, Pd, Pt, Cu, Ge, Ru, Nd, Mg, Ca, Na, W, Zr, Ta, and Hf, or two or more thereof Examples include alloys containing metals.

The metal is preferably silver (Ag) or a silver alloy, more preferably a silver alloy. If the metal is silver or a silver alloy, the resistance value of the light-transmitting conductive layer 4 can be reduced, and in addition, the light transmittance has a particularly high average reflectance in the near-infrared region (wavelength 850 to 2500 nm). The conductive layer 4 is obtained, and can be suitably applied to an image quality display device used outdoors.

Silver alloys contain silver as a main component and other metals as subcomponents. The metal element of the accessory component is not limited. Examples of the silver alloy include an Ag—Cu alloy, an Ag—Pd alloy, an Ag—Pd—Cu alloy, an Ag—Pd—Cu—Ge alloy, an Ag—Cu—Au alloy, an Ag—Cu—In alloy, and an Ag—Cu. -Sn alloy, Ag-Ru-Cu alloy, Ag-Ru-Au alloy, Ag-Nd alloy, Ag-Mg alloy, Ag-Ca alloy, Ag-Na alloy, Ag-Ni alloy, Ag-Ti alloy, Ag- In alloys, Ag—Sn alloys, and the like can be given. From the viewpoint of wet heat durability, the silver alloy is preferably an Ag—Cu alloy, an Ag—Cu—In alloy, an Ag—Cu—Sn alloy, an Ag—Pd alloy, or an Ag—Pd—Cu alloy.

The silver content in the silver alloy is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and for example, 99.9% by mass or less. The content ratio of the other metals in the silver alloy is the balance of the silver content ratio described above.

From the viewpoint of increasing the transmittance of the light-transmissive conductive layer 4, the thickness T3 of the metal layer 6 is, for example, 1 nm or more, preferably 5 nm or more, and, for example, 20 nm or less, preferably 10 nm or less. The thickness T3 of the metal layer 6 is measured by, for example, cross-sectional observation with a transmission electron microscope (TEM).

7). Second Inorganic Oxide Layer The second inorganic oxide layer 7 is a barrier layer that prevents external oxygen, moisture, etc. from entering the metal layer 6, and in particular, a barrier that suppresses discoloration of the metal layer 6 due to wet heat. Is a layer. The second inorganic oxide layer 7 is also an optical adjustment layer for suppressing the visible light reflectance of the metal layer 6 and improving the visible light transmittance of the light transmissive conductive layer 4. The second inorganic oxide layer 7 is preferably a conductive layer that imparts conductivity to the light-transmitting conductive layer 4 together with the metal layer 6, and more preferably a transparent conductive layer.

The second inorganic oxide layer 7 is the uppermost layer in the light-transmissive conductive layer 4 and has a film shape (including a sheet shape). The second inorganic oxide layer 7 is formed on the entire upper surface of the metal layer 6 and on the upper surface of the metal layer 6. It is arranged to come into contact.

Examples of the inorganic oxide forming the second inorganic oxide layer 7 include the inorganic oxides exemplified in the first inorganic oxide layer 5, preferably an oxide containing indium oxide, and more preferably a main metal. An indium oxide-containing oxide whose element is indium (In) is used, and ITO is more preferable.

The inorganic oxide forming the second inorganic oxide layer 7 may be the same as or different from the inorganic oxide forming the first inorganic oxide layer 5, but preferably from the viewpoint of etching property and wet heat durability. , The same inorganic oxide as the first inorganic oxide layer 5.

When the second inorganic oxide layer 7 is made of an oxide containing indium oxide, the ratio of the number of contained impurity metal elements to the number of atoms of the main metal element In in the second inorganic oxide layer 7 (the number of atoms of the impurity metal element) / The number of atoms of In) is equal to or more (for example, 0.001 or more) than the “number of impurities metal element / the number of atoms of In” in the first inorganic oxide layer 5.

When the second inorganic oxide layer 7 is made of ITO, the content of tin oxide (SnO ₂ ) contained in the ITO and the atomic ratio of Sn to In are the same as those of the first inorganic oxide layer 5.

When both the first inorganic oxide layer 5 and the second inorganic oxide layer 7 are made of ITO, the content of tin oxide (SnO ₂ ) contained in the second inorganic oxide layer 7 is preferably It is the same or more (for example, 0.1 mass% or more) than the content of tin oxide (SnO ₂ ) contained in one inorganic oxide layer 5. The Sn atomic ratio Sn / In with respect to In contained in the second inorganic oxide layer 7 is preferably the same as or equal to the Sn atomic ratio with respect to In contained in the first inorganic oxide layer 5. This is the above (specifically, 0.001 or more). Since the second inorganic oxide layer 7 is easily oxidized in contact with the atmosphere and is more easily crystallized than the first inorganic oxide layer 5, the content of tin oxide (SnO ₂ ) in the second inorganic oxide layer 7 Alternatively, the crystallinity of the second inorganic oxide layer 7 can be easily controlled by setting the atomic ratio of Sn to In to be equal to or higher than that of the first inorganic oxide layer 5.

The content ratio of the inorganic oxide in the second inorganic oxide layer 7 is, for example, 95% by mass or more, preferably 98% by mass or more, more preferably 99% by mass or more, and for example, 100% by mass or less. It is.

The second inorganic oxide layer 7 contains crystal grains 11 (see FIG. 2A or FIG. 2B). Thereby, since the crystal structure of the crystal grains 11 is stable and hardly permeates water, it is possible to prevent water from the outside from entering the metal layer 6 through the second inorganic oxide layer 7. . Therefore, the wet heat durability of the light transmissive conductive layer 4 can be improved.

Specifically, the second inorganic oxide layer 7 is a crystal film. As the crystal film, for example, as shown in FIG. 2A, in a side cross-sectional view (particularly, a cross-sectional TEM image), it may be a complete crystal film containing crystal grains 11 continuously in the entire plane direction. As shown in FIG. 2B, it may be a semi-crystalline film containing an amorphous portion 12 (a portion not crystallized) and a crystalline portion 13 (that is, a portion made of crystal grains 11). From the viewpoint of being able to contain the second crystal grains 11b to be described later and further improving the wet heat durability, a semi-crystalline film is preferable.

In the present invention, “containing crystal grains” means that the second inorganic oxide layer 7 is at least one in the range of 500 nm in the plane direction when observed using a cross-sectional TEM image at 200,000 times magnification. It means having the above crystal grains 11. In the above range, the number of crystal grains 11 is preferably 2 or more, more preferably 3 or more, still more preferably 5 or more, and preferably 50 or less, more preferably 40 or less, and still more preferably. Has 30 or less crystal grains 11.

Further, when the upper surface of the second inorganic oxide layer 7 is observed with a planar TEM image at a magnification of 100,000, the area ratio occupied by the crystal grains 11 is, for example, 5% or more, preferably 10% or more. More preferably, it is 20% or more, for example, 100% or less, preferably 90% or less, more preferably 80% or less, further preferably 70% or less, particularly preferably 60% or less. is there.

In addition, when calculating the area ratio which a crystal grain occupies by a plane TEM image, the cross-sectional TEM image of the 1st inorganic oxide layer 5 is confirmed on the above-mentioned conditions, and a crystal grain exists in the 1st inorganic oxide layer 5 After confirming that it does not, a planar TEM image will be observed. It may be difficult to determine which of the first inorganic oxide layer 5 and the second inorganic oxide layer 7 is a crystal grain by using only a planar TEM image. Therefore, in this invention, after confirming that a crystal grain does not exist in the 1st inorganic oxide layer 5 by a cross-sectional TEM image, the crystal grain 11 of the 2nd inorganic oxide layer 7 is observed by observing a plane TEM image. Judge that it is observable.

The size of the crystal grains 11 included in the second inorganic oxide layer 7 is, for example, 3 nm or more, preferably 5 nm or more, more preferably 10 nm or more, for example, 200 nm or less, preferably 100 nm or less, more Preferably, it is 80 nm or less, More preferably, it is 50 nm or less. Within the observation area of the second inorganic oxide layer 7, crystal grains other than the above range may be included, but the area ratio is preferably 30% or less, more preferably 20% or less. More preferably, all the crystal grains 11 included in the second inorganic oxide layer 7 are crystal grains having a size in the above range. The size of the crystal grains 11 is the maximum value of the length that each crystal grain 11 can take when the second inorganic oxide layer 7 is observed using a cross-sectional TEM image at 200,000 times.

The size of the largest crystal grain 11 (maximum crystal grain) among the crystal grains 11 included in the second inorganic oxide layer 7 is, for example, 10 nm or more, preferably 20 nm or more, and, for example, 200 nm or less. The thickness is preferably 100 nm or less.

The shape of the crystal grains is not limited, and examples thereof include a substantially triangular shape in cross section and a substantially rectangular shape in cross section.

Examples of the crystal grains 11 include a first crystal grain 11a that penetrates the second inorganic oxide layer 7 in the thickness direction and a second crystal grain 11b that does not penetrate the second inorganic oxide layer 7 in the thickness direction.

The first crystal grain 11 a is a crystal grain grown so that its upper end is exposed from the upper surface of the second inorganic oxide layer 7 and its lower end is exposed from the lower surface of the second inorganic oxide layer 7. The length in the thickness direction of the first crystal grain 11 a is the same as the thickness of the second inorganic oxide layer 7.

The second crystal grain 11b is a crystal grain grown so that at least one end of the upper end and the lower end thereof is not exposed from the surface (upper surface or lower surface) of the second inorganic oxide layer 7. The second crystal grain 11b is preferably formed such that its upper end is exposed from the upper surface of the second inorganic oxide layer 7 and its lower end is not exposed from the lower surface of the second inorganic oxide layer 7. .

The average length of the second crystal grains 11b in the thickness direction is shorter than the thickness (T2) of the second inorganic oxide layer 7, and is, for example, 98% with respect to 100% of the thickness of the second inorganic oxide layer 7. % Or less, preferably 90% or less, more preferably 80% or less, and for example, 5% or more, preferably 10% or more, more preferably 20% or more.

The second inorganic oxide layer 7 preferably has second crystal grains 11b. Thereby, since the grain boundary of the crystal grain 11 does not penetrate in the thickness direction, water can be prevented from passing through the second inorganic oxide layer 7 in the thickness direction along the grain boundary.

The number of the first crystal grains 11a is, for example, 0 or more, preferably 1 or more, and for example, 30 or less, preferably 10 or less.

The number of the second crystal grains 11b is preferably larger than the number of the first crystal grains 11a, specifically, preferably 1 or more, more preferably 2 or more, and further preferably 3 or more, Moreover, Preferably it is 50 or less, More preferably, it is 40 or less, More preferably, it is 30 or less.

The thickness T2 of the second inorganic oxide layer 7 is, for example, 5 nm or more, preferably 20 nm or more, more preferably 30 nm or more, and for example, 100 nm or less, preferably 60 nm or less, more preferably 50 nm. It is as follows. When the thickness T2 of the second inorganic oxide layer 7 is in the above range, the visible light transmittance of the light transmissive conductive layer 4 can be easily adjusted to a high level. The thickness T2 of the second inorganic oxide layer 7 is measured by, for example, cross-sectional observation with a transmission electron microscope (TEM).

The ratio (T2 / T1) of the thickness T2 of the second inorganic oxide layer 7 to the thickness T1 of the first inorganic oxide layer 5 is, for example, 0.5 or more, preferably 0.75 or more, 1.5 or less, preferably 1.25 or less. If the ratio (T2 / T1) is not less than the above lower limit and not more than the above upper limit, the deterioration of the metal layer 6 can be further suppressed even in a wet heat environment.

The ratio (T2 / T3) of the thickness T2 of the second inorganic oxide layer 7 to the thickness T3 of the metal layer 6 is, for example, 2.0 or more, preferably 3.0 or more, and for example, 10 or less. Preferably, it is 8.0 or less.

The thickness of the light-transmitting conductive layer 4, that is, the total thickness of the first inorganic oxide layer 5, the metal layer 6 and the second inorganic oxide layer 7 is, for example, 20 nm or more, preferably 40 nm or more. Is 60 nm or more, more preferably 80 nm or more, and for example, 150 nm or less, preferably 120 nm or less, more preferably 100 nm or less.

Further, the light transmissive conductive layer 4 may be patterned as shown in FIG. That is, the light transmissive conductive layer 4 can have a pattern shape such as a wiring pattern.

The pattern shape has a non-pattern part 9 and a pattern part 10. The pattern part 10 is formed in a stripe shape or the like. For example, the pattern part 10 extends in the front-rear direction, and a plurality of pattern parts 10 are arranged in the left-right direction at intervals (non-pattern part 9). The non-pattern part 9 is partitioned from the side surface of the adjacent pattern part 10 and the upper surface of the protective layer 3. The width L of each pattern unit 10 is, for example, not less than 1 μm and not more than 3000 μm. The interval S between adjacent pattern portions 10 (that is, the width of the non-pattern portion 9) is, for example, 1 μm or more and 3000 μm or less.

8). Next, a method for producing the light transmissive film 1 will be described.

In order to manufacture the light transmissive film 1, for example, the protective layer 3, the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7 are formed on the transparent substrate 2. Arrange (stack) in the above order.

In this method, as shown in FIG. 1, first, a transparent substrate 2 is prepared.

The amount of water in the transparent substrate 2 (polymer film) to be prepared is not limited, but is, for example, 10 μg / cm ² or more, preferably 15 μg / cm ² or more, and, for example, 200 μg / cm ² or less, preferably Is 170 μg / cm ² or less. If the moisture content is equal to or greater than the lower limit described above, a hydrogen atom or the like is added to the first inorganic oxide layer 5 to suppress the first inorganic oxide layer 5 from being crystallized by heating, which will be described later. It is easy to maintain the amorphous nature of the inorganic oxide layer 5. Moreover, if the amount of moisture is not more than the above upper limit, the second inorganic oxide layer 7 containing the crystal grains 11 can be reliably obtained by a heating step or the like. The amount of water in the transparent substrate 2 is measured according to JIS K 7251 (2002) Method B-water vaporization method.

The content of water contained in the transparent substrate 2 (polymer film) with respect to the transparent substrate 2 is, for example, 0.05% by mass or more, preferably 0.1% by mass or more. For example, it is 1.5% by mass or less, preferably 1.0% by mass or less, and more preferably 0.5% by mass or less.

Note that part or all of the water described above is released to the outside in the degassing process described later.

Next, the resin composition is disposed on the upper surface of the transparent substrate 2 by, for example, wet processing.

Specifically, first, the resin composition is applied to the upper surface of the transparent substrate 2. Thereafter, when the resin composition contains an active energy ray-curable resin, the active energy ray is irradiated.

Thereby, a film-shaped protective layer 3 is formed on the entire upper surface of the transparent substrate 2. That is, the transparent base material 14 with a protective layer provided with the transparent base material 2 and the protective layer 3 is obtained.

Thereafter, the transparent substrate 14 with a protective layer is degassed as necessary.

In order to degas the transparent substrate 14 with a protective layer, the transparent substrate 14 with a protective layer is, for example, 1 × 10 ⁻¹ Pa or less, preferably 1 × 10 ⁻² Pa or less, Leave in a vacuum atmosphere of × 10 ^-6 Pa or higher. The degassing process is performed using, for example, an exhaust device (specifically, a turbo molecular pump or the like) provided in a dry apparatus.

By this degassing treatment, a part of the water contained in the transparent substrate 2 and a part of the organic substance contained in the protective layer 3 are released to the outside.

Next, the light transmissive conductive layer 4 is disposed on the upper surface of the protective layer 3 by, for example, a dry method.

Specifically, each of the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7 is sequentially disposed by a dry method.

Examples of the dry method include a vacuum deposition method, a sputtering method, and an ion plating method. Preferably, a sputtering method is used. Specifically, a magnetron sputtering method can be mentioned.

Examples of the gas used in the sputtering method include an inert gas such as Ar. Moreover, reactive gas, such as oxygen, can be used together as needed. When the reactive gas is used in combination, the flow rate ratio of the reactive gas is not particularly limited, and is a ratio of the reactive gas flow rate to the inert gas flow rate, for example, 0.1 / 100 or more, preferably 1/100 or more, and for example, 5/100 or less.

Specifically, in the formation of the first inorganic oxide layer 5, an inert gas and a reactive gas are preferably used in combination as the gas. In forming the metal layer 6, an inert gas is preferably used alone as the gas. In forming the second inorganic oxide layer 7, an inert gas and a reactive gas are preferably used in combination as the gas.

When the first inorganic oxide layer 5 and the second inorganic oxide layer 7 contain indium oxide, the resistance behavior of each layer varies depending on the amount of reactive gas introduced, and the amount of reactive gas introduced (x In the graph of (axis) -surface resistance value (y-axis), a parabola that protrudes downward is drawn. At this time, the amount of the reactive gas contained in the first inorganic oxide layer 5 and the second inorganic oxide layer 7 is an introduction amount in which the resistance value is near the minimum value (that is, the inflection point of the parabola). Specifically, it is preferable that the introduction amount is ± 20% so that the resistance value becomes the minimum value.

When employing the sputtering method, examples of the target material include the above-described inorganic oxides or metals constituting each layer.

There is no limitation in the power supply used by sputtering method, For example, DC power supply, MF / AC power supply, and RF power supply are used individually or together, Preferably, DC power supply is mentioned.

Also preferably, when the first inorganic oxide layer 5 is formed by a sputtering method, the transparent substrate 2 (and the protective layer 3) is cooled. Specifically, the transparent substrate 2 (and the protective layer 3) is cooled by bringing the lower surface of the transparent substrate 2 into contact with a cooling device (for example, a cooling roll). Thereby, when the first inorganic oxide layer 5 is formed, a large amount of water contained in the transparent substrate 2 and the organic matter contained in the protective layer 3 are released by heat of vapor deposition caused by sputtering, and the like. It can suppress that water is excessively contained in the first inorganic oxide layer 5. The cooling temperature is, for example, −30 ° C. or more, preferably −10 ° C. or more, and for example, 60 ° C. or less, preferably 40 ° C. or less, more preferably 30 ° C. or less, and further preferably 20 ° C. Hereinafter, it is particularly preferably less than 0 ° C. Preferably, the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7 are all formed by sputtering while cooling in the above temperature range. Thereby, aggregation of the metal layer 6 and excessive oxidation of the second inorganic oxide layer 7 can be suppressed.

Thereby, the light-transmitting conductive layer 4 in which the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7 are formed in this order is formed on the protective layer 3, and the light-transmitting conductive layer is formed. A laminate is obtained. At this time, both of the first inorganic oxide layer 5 and the second inorganic oxide layer 7 immediately after film formation (for example, within 24 hours after the formation of the light-transmitting conductive layer laminate) contain crystal grains 11. Absent.

Next, a crystallization step for generating crystal grains 11 in the second inorganic oxide layer 7 is performed. The crystallization process is not limited as long as the crystal grains 11 can be formed. For example, a heating process can be mentioned. That is, the light transmissive conductive layer laminate is heated.

The heating process is not only performed for the purpose of generating the crystal grains 11 but also accompanying the curl removal of the light transmissive conductive layer laminate and the dry formation of the silver paste wiring. Heating may be used.

The heating temperature can be appropriately set, for example, 30 ° C. or higher, preferably 40 ° C. or higher, more preferably 80 ° C. or higher, and for example, 180 ° C. or lower, preferably 150 ° C. or lower.

The heating time is not limited and is set according to the heating temperature. For example, it is 1 minute or more, preferably 10 minutes or more, more preferably 30 minutes or more, and for example, 4000 hours or less, preferably Is less than 100 hours.

The heating may be performed in any of an air atmosphere, an inert atmosphere, and a vacuum, but is preferably performed in an air atmosphere from the viewpoint of facilitating crystallization.

In this heating step, the second inorganic oxide layer 7 is crystallized, and crystal grains 11 exist in the second inorganic oxide layer 7. In particular, the second inorganic oxide layer 7 includes water from the transparent substrate 2 and the protective layer 3 in which the metal layer 6 interposed between the transparent substrate 2 and the second inorganic oxide layer 7 inhibits crystallization. The second inorganic oxide layer 7 can be easily crystallized because it is easy to take in oxygen necessary for crystallization by being exposed to the organic matter from and being exposed during the heating step. Note that the first inorganic oxide layer 5 is greatly influenced by water and organic matter, and is difficult to take up oxygen, so that the growth of the crystal grains 11 is inhibited and the amorphousness is maintained.

Thereby, as shown in FIG. 1, the transparent substrate 2, the protective layer 3, and the light-transmissive conductive layer 4 (the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7). In order, the light-transmitting film 1 in which only the second inorganic oxide layer 7 contains crystal grains 11 is obtained.

The surface resistance value of the light-transmitting conductive layer 4 is, for example, 40Ω / □ or less, preferably 30Ω / □ or less, more preferably 20Ω / □ or less, and further preferably 15Ω / □ or less. 1Ω / □ or more, preferably 1Ω / □ or more, more preferably 5Ω / □ or more.

The specific resistance of the light-transmitting conductive layer 4 is, for example, 2.5 × 10 ⁻⁴ Ω · cm or less, preferably 2.0 × 10 ⁻⁴ Ω · cm or less, more preferably 1.1 × 10 ^{− 4} Ω · cm or less, for example, 0.01 × 10 ⁻⁴ Ω · cm or more, preferably 0.1 × 10 ⁻⁴ Ω · cm or more, more preferably 0.5 × 10 ^−4. Ω · cm or more.

The specific resistance of the light transmissive conductive layer 4 includes the thickness of the light transmissive conductive layer 4 (the total thickness of the first inorganic oxide layer, the metal layer 6 and the second inorganic oxide layer 7) and the light transmissive conductive layer 4. It is calculated using the surface resistance value.

The light-transmitting conductive layer 4 preferably has a high near-infrared (wavelength 850 to 2500 nm) average reflectance, for example, a metal layer 6 (for example, containing silver or a silver alloy) having a high reflectance in the near-infrared region. A metal layer 6). The light transmissive conductive layer 4 has a high near-infrared reflectance as compared with, for example, a transparent inorganic oxide made of a conductive oxide (for example, ITO), and can efficiently block heat rays such as sunlight. . Therefore, the present invention can also be suitably applied to an image display device used in an environment where the panel temperature is likely to rise (for example, outdoors). The average reflectance of the near-infrared ray (wavelength 850 to 2500 nm) of the light-transmissive conductive layer 4 is, for example, 10% or more, preferably 20% or more, more preferably 50% or more, and for example, 95% Hereinafter, it is preferably 90% or less.

Since the light transmissive film 1 includes the light transmissive conductive layer 4 including the optical adjustment layers (the first inorganic oxide layer 5 and the second inorganic oxide layer 7) on the upper surface and the lower surface of the metal layer 6, the light transmissive film 1. Even if the conductive layer 4 includes a metal layer 6 having a generally high visible light reflectivity (specifically, for example, a metal layer 6 having a reflectivity of 15% or more and further 30% or more at a wavelength of 550 nm). High visible light transmittance can be realized. The visible light transmittance of the light transmissive film 1 is, for example, 60% or more, preferably 80% or more, more preferably 85% or more, and for example, 95% or less.

The total thickness of the light transmissive film 1 is, for example, 2 μm or more, preferably 20 μm or more, and for example, 300 μm or less, preferably 200 μm or less, more preferably 150 μm or less.

Next, when forming a pattern shape on the light transmissive conductive layer 4, the light transmissive conductive layer 4 is patterned by etching.

Specifically, first, the photosensitive film is disposed on the entire upper surface of the second inorganic oxide layer 7, and then exposed through a photomask having a pattern corresponding to the non-pattern part 9 and the pattern part 10, Then, the photosensitive film corresponding to the non-pattern part 9 is removed by developing. Thereby, an etching resist having the same pattern as the pattern portion is formed on the upper surface of the light-transmitting conductive layer 4 to be the pattern portion 10. Thereafter, the light transmissive conductive layer 4 exposed from the etching resist is etched using an etchant. Examples of the etching solution include acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, succinic acid, phosphoric acid, and mixed acids thereof.

Thereafter, the etching resist is removed from the upper surface of the second inorganic oxide layer 7 by, for example, peeling.

Thereby, as shown in FIG. 3, the light transmissive film 1 (patterning light transmissive film) provided with the transparent base material 2, the protective layer 3, and the light transmissive conductive layer 4 having a pattern shape in order is obtained. It is done.

In addition, the above-described manufacturing method can be performed by a roll-to-roll method. Moreover, a part or all can also be implemented by a batch system.

Thereafter, the light transmissive film 1 is provided in an optical device, for example. Examples of the optical device include an image display device and a light control device.

When the light transmissive film 1 is provided in an image display device (specifically, an image display device having an image display element such as an LCD module), the light transmissive film 1 is used as a base material for a touch panel, for example. . Examples of the touch panel format include various systems such as an optical system, an ultrasonic system, a capacitive system, and a resistive film system, and the touch panel is particularly preferably used for a capacitive touch panel.

Moreover, the light transmissive film 1 can be used as, for example, a near-infrared reflecting base material. For example, by providing the image display device with the light transmissive film 1 having a high average reflectance (for example, 10% or more) of near infrared rays having a wavelength of 850 to 2500 nm, the image display device can be suitably applied to an image quality display device for outdoor use. The light transmissive film 1 can also be provided in an image display device as a light transmissive conductive layer laminated polarizing film in which a polarizer such as a polarizing film or a polarizing plate is bonded via an adhesive layer or an adhesive layer.

Further, when the light transmissive film 1 is provided in a light control device (specifically, a light control device having a light source such as an LED), the light transmissive film 1 is provided as a light control film, for example.

9. Effects According to the light transmissive film 1 of the first embodiment, the light transmissive conductive layer 4 includes the first inorganic oxide layer 5 not containing the crystal grains 11, the metal layer 6, and the crystal grains 11. A second inorganic oxide layer 7 is provided in order. For this reason, water in the atmosphere can be prevented from passing through the second inorganic oxide layer 7 in the thickness direction and entering the metal layer 6. Moreover, the wettability of the 1st inorganic oxide layer 5 is favorable, and the metal layer 6 and the 2nd inorganic oxide layer 7 can be formed into a thin and uniform film on the upper surface of the first inorganic oxide layer 5. Therefore, the film quality of the light transmissive conductive layer 4 is good. Therefore, it is excellent in wet heat durability. That is, corrosion and discoloration of the metal layer 6 can be suppressed, and appearance defects due to wet heat can be suppressed.

Moreover, since the light-transmissive conductive layer 4 has the metal layer 6 interposed between the first inorganic oxide layer 5 and the second inorganic oxide layer 7, the surface resistance value can be lowered.

Furthermore, since the light transmissive conductive layer 4 has a three-layer structure of the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7, the transparency is excellent. As a result, when the light transmissive conductive layer 4 is patterned, the visual recognition of the wiring pattern can be suppressed.

Moreover, in the light transmissive film 1, if the metal layer 6 is a silver layer or a silver alloy layer, the resistance can be further reduced, and the average reflectance of near infrared rays is high, so that heat rays such as sunlight can be reduced. Can be cut off efficiently.

Further, in the light transmissive film 1, when both the first inorganic oxide layer 5 and the second inorganic oxide layer 7 contain indium tin composite oxide, the wet heat durability is further improved. Moreover, it is excellent in transparency and the visual recognition of a wiring pattern can be suppressed effectively.

Further, in the light transmissive film 1, if the second inorganic oxide layer 7 is a semi-crystalline film having an amorphous portion 12 and a crystalline portion 13, the wet heat durability is further improved.

Further, in the light transmissive film 1, if the second inorganic oxide layer 7 contains the second crystal grains 11 b that do not penetrate the second inorganic oxide layer 7 in the thickness direction, water is contained in the second inorganic oxide layer 7. Can be further suppressed from passing through the grain boundary in the thickness direction and entering the metal layer 6. Therefore, the wet heat durability is further improved.

In particular, in the case of a three-layer structure in which the metal layer 6 is contained between the first inorganic oxide layer 5 and the second inorganic oxide layer 7, the metal layer 6 is relatively aggregated and corroded (discolored). It is easy to cause appearance failure and resistance failure. For this reason, in the second inorganic oxide layer 7, the more the first crystal grains 11 a are, the easier it is for water to enter the metal layer 6, and the wet heat durability may be difficult to improve. On the other hand, in the second inorganic oxide layer 7, the more the second crystal grains 11b, the more effectively water can be prevented from entering the vicinity of the metal layer 6 and the wet heat durability can be further improved.

On the other hand, for example, when the light-transmitting conductive layer 4 has a two-layer structure of the first inorganic oxide layer 5 and the second inorganic oxide layer 7 in which the metal layer 6 is not interposed as in the prior art. In addition, since the inorganic oxide layers are in contact with each other, the appearance defect associated with the aggregation of the metal layer 6 as described above cannot occur. Therefore, in such a case, the second inorganic oxide layer 7 may have a large amount of the first crystal grains 11a penetrating in the thickness direction, but rather has the maximum crystallization characteristics (such as low resistance). From the viewpoint of limiting, the second inorganic oxide layer 7 is preferably a complete crystal film.

Moreover, in the light transmissive film 1, if the light transmissive conductive layer 4 has a pattern shape, it can be suitably used as, for example, a touch panel substrate or a near infrared reflecting substrate. In particular, the light-transmitting conductive layer 4 (wiring pattern) having a pattern shape is excellent in wet heat durability against water entering in the thickness direction, and therefore, corrosion and discoloration of the upper surface of the metal layer 6 can be reliably suppressed. it can.

[Second Embodiment]
With reference to FIG. 4, the light transmissive film 1 of 2nd Embodiment is demonstrated. Note that in the second embodiment, the same members and steps as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

Specifically, as shown in FIG. 4, the light transmissive film 1 of the second embodiment includes, in order, a transparent substrate 2, a protective layer 3, a light transmissive conductive layer 4, and an adhesive layer 15. Is a light transmissive laminated film. That is, the light transmissive film 1 includes a transparent base material 2, a protective layer 3 disposed above the transparent base material 2, a light transmissive conductive layer 4 disposed above the protective layer 3, and a light transmissive property. And an adhesive layer 15 provided on the upper side of the conductive layer 4. Preferably, the light transmissive film 1 includes only the transparent substrate 2, the protective layer 3, the light transmissive conductive layer 4, and the pressure-sensitive adhesive layer 15.

The light transmissive conductive layer 4 has a pattern shape. That is, the light transmissive conductive layer 4 includes a non-pattern part 9 and a pattern part 10.

The pressure-sensitive adhesive layer 15 is used to fix the transparent protective layer and the light transmissive film 1 when a transparent protective layer is disposed on the light transmissive conductive layer 4 side of the light transmissive film 1 to produce an optical device. It is an adhesive layer. The pressure-sensitive adhesive layer 15 is also a protective layer for preventing the light transmissive conductive layer 4 from being directly exposed to the atmosphere.

The pressure-sensitive adhesive layer 15 has a film shape (including a sheet shape), and is disposed on the upper side of the light-transmitting conductive layer 4 (the side opposite to the transparent base material 2). Specifically, the pressure-sensitive adhesive layer 15 covers the upper surface and the side surface of the light transmissive conductive layer 4 and the upper surface of the protective layer 3 exposed from the light transmissive conductive layer 4. The transparent conductive layer 4 is disposed on the upper side.

The pressure-sensitive adhesive layer 15 is prepared from a pressure-sensitive adhesive composition.

The adhesive composition contains, for example, an adhesive resin.

Examples of the adhesive resin include acrylic resin, rubber (such as butyl rubber), silicone resin, polyester resin, polyurethane, polyamide, epoxy resin, vinyl alkyl ether resin, and fluorine resin, preferably from the viewpoint of adhesiveness. And acrylic resin.

The pressure-sensitive adhesive composition preferably contains a benzotriazole-based compound. When the pressure-sensitive adhesive layer 15 contains a benzotriazole-based compound, the wet heat durability on the side surface of the patterned light-transmitting conductive layer 4 can be further improved.

Examples of the benzotriazole compounds include benzotriazole compounds described in JP 2014-177612 A. Preferably, 1,2,3-benzotriazole, 5-methylbenzotriazole, 1- [N, N-bis (2-ethylhexyl) aminomethyl] benzotriazole, 1- [N, N-bis (2-ethylhexyl) Aminomethyl] methylbenzotriazole and the like.

The pressure-sensitive adhesive composition is, for example, an additive such as a filler, an antioxidant, a softener, a thixotropic agent, a lubricant, a pigment, a scorch inhibitor, a stabilizer, an ultraviolet absorber, a colorant, an antifungal agent, and a flame retardant. Can also be contained in an appropriate ratio.

The thickness T4 of the pressure-sensitive adhesive layer 15 is, for example, 2 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and for example, 200 μm or less, preferably 100 μm or less, more preferably 70 μm or less. .

For the pressure-sensitive adhesive layer 15, the pressure-sensitive adhesive composition is disposed on the upper surface of the light-transmitting conductive layer 4 by, for example, wet processing.

Specifically, first, the pressure-sensitive adhesive composition is applied to the upper surface of the patterned light-transmitting conductive layer 4 and the upper surface of the protective layer 3 of the non-patterned portion 9. Thereafter, the pressure-sensitive adhesive composition is dried by heating, or the pressure-sensitive adhesive composition is cured by irradiation with active energy rays.

In order to arrange the pressure-sensitive adhesive layer 15, first, the pressure-sensitive adhesive layer 15 is arranged on a release base material to produce a base material with a pressure-sensitive adhesive layer, and then the pressure-sensitive adhesive layer is used by using the base material with the pressure-sensitive adhesive layer. It is also possible to transfer the layer 15 to the light transmissive conductive layer 4.

Thereby, as shown in FIG. 4, a light transmissive film 1 including a transparent base material 2, a protective layer 3, a light transmissive conductive layer 4 having a pattern shape, and an adhesive layer 15 in order is obtained.

The light transmissive film 1 of the second embodiment also has the same effects as the light transmissive film 1 of the first embodiment.

In addition, since the light transmissive film 1 further includes the pressure-sensitive adhesive layer 15 provided on the upper surface of the light transmissive conductive layer 4, the amount of water that can enter the light transmissive conductive layer 4 is reduced, Excellent wet heat durability. Moreover, in the light-transmitting conductive layer 4 having a pattern shape (such as a wiring pattern), the side surface of the pattern can be protected, and the wet heat durability on the side surface is excellent. Specifically, corrosion and discoloration on the side surface of the metal layer 6 can be reliably suppressed, and the performance (conductivity, etc.) of the wiring pattern can be more reliably maintained.

[Modification]
In the modified example, the same members and steps as those in the first embodiment and the second embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

In the above embodiment, for example, as shown in FIGS. 1 and 4, the light transmissive conductive layer 4 is provided on the transparent base material 2. The light transmissive conductive layer 4 can also be provided. That is, the light transmissive film 1 can include the protective layer 3 and the light transmissive conductive layer 4 in order on both the upper and lower sides of the transparent substrate 2.

In the above embodiment, for example, as shown in FIGS. 1 and 4, the protective layer 3 is interposed between the transparent substrate 2 and the first inorganic oxide layer 5. However, for example, as shown in FIG. 5, the first inorganic oxide layer 5 can be disposed directly on the upper surface of the transparent substrate 2. That is, the light transmissive film 1 includes a transparent substrate 2, a first inorganic oxide layer 5, a metal layer 6, and a second inorganic oxide layer 7 in this order. On the other hand, the light transmissive film 1 does not include the protective layer 3.

In the above embodiment, for example, as shown in FIGS. 1 and 4, the first inorganic oxide layer 5 is directly disposed on the upper surface of the protective layer 3. However, for example, as shown in FIG. 6, the optical adjustment layer 16 may be interposed between the protective layer 3 and the first inorganic oxide layer 5.

The optical adjustment layer 16 is an optical adjustment layer (second optical adjustment layer) that adjusts the optical properties of the light transmissive film 1 so as to suppress the visual recognition of the wiring pattern in the light transmissive conductive layer 4 together with the protective layer 3. is there. The optical adjustment layer 16 has a film shape (including a sheet shape) and is disposed on the entire upper surface of the protective layer 3 so as to be in contact with the upper surface of the protective layer 3. The optical adjustment layer 16 has predetermined optical properties, and is prepared, for example, from an inorganic material such as an oxide or fluoride, or a resin composition such as an acrylic resin or a melamine resin. The optical adjustment layer 16 may be a single layer or a multilayer having different compositions. The thickness of the optical adjustment layer 16 is 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and for example, 500 nm or less, preferably 200 nm or less, more preferably 50 nm or less, still more preferably, 25 nm or less.

In the above embodiment, as shown in FIG. 1, the light transmissive conductive layer 4 includes only the first inorganic oxide layer 5, the metal layer 6, and the second inorganic oxide layer 7. However, for example, although not shown, a second metal layer and a third inorganic oxide layer can be arranged in order on the upper surface of the second inorganic oxide layer 7, and further, the third inorganic oxide A third metal layer and a fourth inorganic oxide layer can also be disposed on the upper surface of the layer.

Moreover, although not shown in figure, functional layers, such as an antifouling layer, adhesion | attachment, a water repellent layer, an antireflection layer, an oligomer prevention layer, can also be arrange | positioned on the upper surface and / or lower surface of the 1st transparent base material 2, for example. . The functional layer preferably contains the above-described resin composition. Such a functional layer is appropriately selected according to a required function.

In the method for producing the light transmissive film 1, patterning is performed after the heating step. However, for example, the heating step can be performed after patterning. Moreover, although the 2nd inorganic oxide layer 7 is crystallized by the heating process, the 2nd inorganic oxide layer 7 can also be crystallized by exposing for several months or more in an atmospheric condition, for example.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, this invention is not limited to an Example and a comparative example at all. In addition, specific numerical values such as a blending ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned “Mode for Carrying Out the Invention”, and a blending ratio corresponding to them ( Substituting the upper limit value (numerical value defined as “less than” or “less than”) or the lower limit value (number defined as “greater than” or “exceeded”) such as content ratio), physical property values, parameters, etc. be able to.

Example 1
(Preparation of film substrate and formation of protective layer)
First, a transparent substrate made of a long polyethylene terephthalate (PET) film and having a thickness of 50 μm was prepared. In addition, the water content in the prepared transparent base material was 19 microgram / cm < ² >, and content with respect to the transparent base material of water was also 0.27 mass%.

Next, an ultraviolet curable resin made of an acrylic resin was applied to the upper surface of the transparent substrate, and cured by ultraviolet irradiation to form a protective layer made of a cured resin layer and having a thickness of 2 μm. Thereby, the transparent base material roll with a protective layer provided with a transparent base material and a protective layer was obtained.

(Formation of first inorganic oxide layer)
Next, the transparent substrate roll with a protective layer was installed in a vacuum sputtering apparatus, and was evacuated until the atmospheric pressure when not transported was 2 × 10 ⁻³ Pa (degassing treatment). At this time, a part of the transparent substrate with a protective layer was transported without introducing the sputtering gas (Ar and O ₂ ), and it was confirmed that the atmospheric pressure increased to 1 × 10 ⁻² Pa. Thereby, it was confirmed that a sufficient amount of gas remained in the transparent substrate roll with a protective layer.

Next, a first inorganic oxide layer made of an indium tin oxide layer and having a thickness of 40 nm was formed on the upper surface of the cured resin layer while feeding the transparent substrate roll with a protective layer by sputtering.

Specifically, under a vacuum atmosphere of atmospheric pressure 0.2 Pa into which Ar and O ₂ were introduced (flow rate ratio: Ar: O ₂ = 100: 3.8), using a direct current (DC) power source, An ITO target made of a sintered body of tin oxide and 88% by mass of indium oxide was sputtered.

When the first inorganic oxide layer is formed by sputtering, the lower surface of the transparent substrate roll with a protective layer (specifically, the lower surface of the transparent substrate) is brought into contact with a −5 ° C. cooling roll for protection. The layered transparent substrate roll was cooled.

(Formation of metal layer)
A metal layer made of an Ag alloy and having a thickness of 8 nm was formed on the upper surface of the first inorganic oxide layer 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 at a pressure of 0.4 Pa into which Ar was introduced.

(Formation of second inorganic oxide layer)
A second inorganic oxide layer made of ITO and having a thickness of 38 nm was formed on the upper surface of the metal layer by sputtering.

Specifically, under a vacuum atmosphere of atmospheric pressure 0.2 Pa into which Ar and O ₂ were introduced (flow rate ratio: Ar: O ₂ = 100: 4.0), using a direct current (DC) power source, An ITO target made of a sintered body of tin oxide and 88% by mass of indium oxide was sputtered.

Thereafter, a heating step was performed under conditions of 80 ° C. and 12 hours in an air atmosphere. Thereby, the second inorganic oxide layer was crystallized.

Thereby, a light-transmitting film in which a protective layer, a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer were formed in this order on a transparent substrate was obtained.

Example 2
Sputtering an ITO target made of a sintered body of 3% by mass of tin oxide and 97% by mass of indium oxide with a flow ratio of Ar and O ₂ of Ar: O ₂ = 100: 3.1 A light transmissive film was obtained in the same manner as in Example 1 except that two inorganic oxide layers were formed.

Comparative Example 1
A light transmissive film was obtained in the same manner as in Example 1 except that the thickness of each layer was changed to the thickness described in Table 1 and the heating step was not performed in the formation of the second inorganic oxide layer.

Comparative Example 2
The flow ratio of Ar and O ₂ at the time of sputtering was Ar: O ₂ = 100: 1.0, the thickness of each layer was changed to the thickness described in Table 1, and light transmittance was achieved without forming a metal layer. A light-transmitting film was obtained in the same manner as in Example 1 except that a conductive layer was formed and then a heating process was performed at 140 ° C. for 1 hour in an air atmosphere.

(Measurement)
(1) Thickness The thicknesses of the protective layer, the first inorganic oxide layer, the metal layer, and the second inorganic oxide were measured by cross-sectional observation using a transmission electron microscope (manufactured by Hitachi, “HF-2000”). The thickness of the base material was measured using a film thickness meter (Digital Dial Gauge DG-205 manufactured by Peacock). The results are shown in Table 1.

(2) Observation of crystal grains by cross-sectional TEM Cross-sections of the first inorganic oxide layer and the second inorganic oxide layer using a transmission electron microscope (manufactured by Hitachi, “HF-2000”, magnification 200,000 times) Was observed. The number of crystal grains per plane direction distance of 500 nm in the cross-sectional view at that time was counted. Moreover, the length of the largest crystal grain of the crystal grain produced in the inorganic oxide layer was measured. The results are shown in Table 1.

(3) Observation of crystal grains by planar TEM In the light transmissive films of Examples and Comparative Examples in which the crystal grains were confirmed by cross-sectional TEM, a transmission electron microscope (“H-7650” manufactured by Hitachi, Ltd.) was used. The top surface of the second inorganic oxide layer was observed to obtain a planar image with a magnification of 100,000. Next, the ratio of the area of the crystal grains (the crystallized portion) to the area of the entire second inorganic oxide layer was measured. The results are shown in Table 1. In Example 1, the number of second crystal grains was larger than the number of first crystal grains.

(4) Wet heat durability The light transmissive film of each example and each comparative example was cut into a size of 10 cm × 10 cm, and an adhesive layer (“CS9904U” manufactured by Nitto Denko Corporation) was formed on the light transmissive conductive layer. After being bonded to a glass substrate, the substrate was left for 240 hours at 60 ° C. and 95% RH. Thereafter, the upper surface of the light transmissive conductive layer at the center 8 cm × 8 cm portion was visually observed.

At this time, the appearance was evaluated based on the following criteria.
A: White point defects (aggregation, corrosion sites) are not observed (0).
◯: White point defects are more than 0 and 5 or less.
X: There are more than 5 white point defects.

(5) Surface resistance of light transmissive conductive layer The surface resistance value of the light transmissive conductive layer was measured according to the four-probe method of JIS K7194 (1994). The results are shown in Table 1.

(6) Visible Light Transmittance Using a haze meter (manufactured by Suga Test Instruments Co., Ltd., device name “HGM-2DP”), the total light transmittance was measured to obtain the visible light transmittance, and the results are shown in Table 1.

(7) Near-infrared reflection characteristics The average reflectance of the near-infrared rays (wavelength 850 to 2500 nm) of the light transmissive films of Examples 1 and 2 was measured and found to be 58%. From this, it turns out that the light transmissive film of an Example has a favorable near-infrared reflective characteristic.

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 limited manner. Variations of the present invention that are apparent to one of ordinary skill in the art are within the scope of the following claims.

The light transmissive film of the present invention can be applied to various industrial products, and can be suitably used for optical devices such as image display devices and light control devices, for example.

DESCRIPTION OF SYMBOLS 1 Light transmissive film 2 Transparent base material 4 Light transmissive conductive layer 5 1st inorganic oxide layer 6 Metal layer 7 2nd inorganic oxide layer 11 Crystal grain 12 Amorphous part 13 Crystalline part 15 Adhesive layer

Claims (8)

1. A transparent base material and a light-transmitting conductive layer are provided in order,
   The light-transmitting conductive layer includes a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer in order from the transparent substrate,
   The first inorganic oxide layer does not contain crystal grains,
   The light transmissive film, wherein the second inorganic oxide layer contains crystal grains.
2. The light transmissive film according to claim 1, wherein the metal layer is a silver layer or a silver alloy layer.
3. 2. The light transmissive film according to claim 1, wherein each of the first inorganic oxide layer and the second inorganic oxide layer contains indium oxide.
4. 2. The light transmissive film according to claim 1, wherein each of the first inorganic oxide layer and the second inorganic oxide layer contains an indium tin composite oxide.
5. The light transmissive film according to claim 1, wherein the second inorganic oxide layer is a semi-crystalline film having an amorphous part and a crystalline part.
6. The light transmissive film according to claim 1, wherein the second inorganic oxide layer contains crystal grains that do not penetrate the second inorganic oxide layer in the thickness direction.
7. The light transmissive film according to claim 1, wherein the light transmissive conductive layer has a pattern shape.
8. The light transmissive film according to claim 7, further comprising a pressure-sensitive adhesive layer provided on a surface opposite to the light transmissive conductive layer with respect to the transparent substrate.

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