Anti-reflective film

Abstract

To provide an anti-reflective film with a wide wavelength range and low reflectivity. [Solution] The anti-reflective film 1 comprises a transparent base film 2, an intermediate layer 3, and an anti-reflective layer 4, arranged sequentially on one side in the thickness direction. The refractive index when light with a wavelength of 550 nm is incident on the intermediate layer 3 is 1.7 or more and 1.9 or less. The anti-reflective layer 4 includes two or more laminates 10, each comprising a high refractive index layer 41 and a low refractive index layer 42. The refractive index when light with a wavelength of 550 nm is incident on the high refractive index layer 41 is greater than 2.50 and 2.80 or less.

Description

[Technical Field]

[0001] This invention relates to an anti-reflective film. [Background technology]

[0002] In image display devices such as liquid crystal displays and organic EL displays, an anti-reflective film is placed on the outermost surface of the display screen to prevent reflection of ambient light. Such an anti-reflective film comprises a transparent substrate film and an anti-reflective layer including a high refractive index layer and a low refractive index layer.

[0003] As such, it has been proposed that high anti-reflective performance can be achieved over a wide wavelength range from the ultraviolet to the infrared region by forming an intermediate refractive index material between a transparent substrate film and an anti-reflective layer (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2003-248103 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the anti-reflective films mentioned above have an average reflectance (reflectance Y) of only about 0.5% in the wavelength range of 350 to 800 nm, which is insufficient to adequately prevent reflection of ambient light in image display devices such as liquid crystal displays and organic EL displays. On the other hand, anti-reflective films are desirable to have an even lower reflectance Y over a wider wavelength range.

[0006] The present invention aims to provide an anti-reflective film with a wide wavelength range and low reflectivity. [Means for solving the problem]

[0007] The present invention [1] includes a transparent substrate film, an intermediate layer, and an antireflection layer in this order toward one side in the thickness direction, wherein the refractive index when light with a wavelength of 550 nm is incident on the intermediate layer is 1.7 or more and 1.9 or less, and the antireflection layer includes two or more laminates each including a high refractive index layer and a low refractive index layer, and the refractive index when light with a wavelength of 550 nm is incident on the high refractive index layer exceeds 2.50 and is 2.80 or less, and the antireflection film is included.

[0008] The present invention [2] includes the antireflection film according to [1], wherein the high refractive index layer includes a crystal in which a diffraction spot group of Ti2O3 appears in an electron diffraction image observed with a transmission electron microscope.

[0009] The present invention [3] includes the antireflection film according to [1], wherein the intermediate layer includes an inorganic oxide.

[0010] The present invention [4] includes the antireflection film according to any one of [1] to [3], wherein when light with a wavelength of 38~780 nm is incident on the antireflection film, the reflectance Y in the CIE-XYZ color system of the reflected light is 0.4% or less, and the wavelength band where the spectral reflectance is 1% or less is 280 nm or more.

Effects of the Invention

[0011] The antireflection film of the present invention includes a transparent substrate film, an intermediate layer, and an antireflection layer in this order toward one side in the thickness direction, wherein the refractive index when light with a wavelength of 550 nm is incident on the intermediate layer is 1.7 or more and 1.9 or less, and the antireflection layer includes two or more laminates each composed of a high refractive index layer and a low refractive index layer, and the refractive index when light with a wavelength of 550 nm is incident on the high refractive index layer exceeds 2.50 and is 2.80 or less. Therefore, in a wide wavelength band, the reflectance Y of the antireflection film can be lowered.

Brief Description of the Drawings

[0012] [Figure 1] FIG. 1 shows a cross-sectional view of an embodiment of the antireflection film of the present invention. [Figure 2] Figure 2 shows the manufacturing method of the antireflection film shown in Figure 1. Figure 2A shows the step of preparing a transparent resin film, Figure 2B shows the step of forming a cured resin layer on the transparent resin film, Figure 2C shows the step of forming an intermediate layer on the cured resin layer, Figure 2D shows the step of forming an antireflection layer on the intermediate layer, and Figure 2E shows the step of forming an antifouling layer on the antireflection layer. [Figure 3] Figure 3 shows a cross-sectional view of an embodiment of a modified example of the antireflection film shown in Figure 1.

Embodiments for Carrying Out the Invention

[0013] 1. Antireflection Film Referring to Figure 1, an embodiment of the antireflection film of the present invention will be described.

[0014] The antireflection film 1 has a film shape (including a sheet shape) with a predetermined thickness as shown in Figure 1. Further, the antireflection film 1 extends in a plane direction orthogonal to the thickness direction, and one surface in the thickness direction and the other surface in the thickness direction of the antireflection film are flat.

[0015] The antireflection film 1 includes a transparent base film 2, an intermediate layer 3, and an antireflection layer 4 in this order toward one side in the thickness direction. The antireflection film 1 may further include an antifouling layer 5 on one side in the thickness direction of the antireflection layer 4. Specifically, as shown in Figure 1, the antireflection film 1 includes a transparent base film 2, an intermediate layer 3 disposed on one surface in the thickness direction of the transparent base film 2, an antireflection layer 4 disposed on one surface in the thickness direction of the intermediate layer 3, and an antifouling layer 5 disposed on one surface in the thickness direction of the antireflection layer 4.

[0016] <Transparent Base Film> The transparent base film 2 is the bottom layer of the anti-reflective film 1. The transparent base film 2 is a transparent, flexible resin film. The transparent base film 2 also comprises, for example, a transparent resin film 21 and a cured resin layer 22 disposed on one side of the transparent resin film 21 in the thickness direction. Preferably, the transparent base film 2 consists of a transparent resin film 21 and a cured resin layer 22 disposed on one side of the transparent resin film 21 in the thickness direction.

[0017] Examples of materials for the transparent resin film 21 include cellulose resin, polyester resin, (meth)acrylic resin (acrylic resin and / or methacrylic resin), olefin resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, polystyrene resin, norbornene resin, and polyvinyl alcohol resin. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include polyethylene, polypropylene, and cycloolefin polymer (COP). Examples of cellulose resins include triacetylcellulose (TAC). The materials for the transparent resin film 21 can be used individually or in combination of two or more types.

[0018] The transparent resin film 21 can be, for example, a cellulose resin film, from the viewpoint of transparency, heat resistance, and mechanical strength. Preferably, a triacetylcellulose film is used.

[0019] The total light transmittance (JIS K-7105) of the transparent resin film 21 is, for example, 80% or more, preferably 85% or more, more preferably 88% or more, even more preferably 90% or more, and also, for example, 100% or less.

[0020] The thickness of the transparent resin film 21 is not particularly limited, but from the viewpoint of strength and handling, for example, it is 5 μm or more, preferably 10 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, particularly preferably 50 μm or more, and for example, 300 μm or less, preferably 250 μm or less, more preferably 200 μm or less, even more preferably 170 μm or less, particularly preferably 150 μm or less.

[0021] The thickness of the transparent resin film 21 can be measured, for example, using a film thickness gauge.

[0022] The cured resin layer 22 improves the mechanical properties of the anti-reflective film 1. The cured resin layer 22 is in contact with one side of the transparent resin film 21 in the thickness direction.

[0023] Examples of the cured resin layer 22 include a hard coat layer and an anti-blocking layer. The hard coat layer, for example, makes it difficult for scratches to form on the exposed surface of the transparent resin film 21. The anti-blocking layer, for example, when the anti-reflective film 1 is laminated in the thickness direction, provides anti-blocking properties to the surfaces of each of the multiple anti-reflective films 1 that come into contact with each other.

[0024] The cured resin layer 22 is, for example, a cured product of a curable resin composition. Specifically, the cured resin layer 22 can be formed by applying a curable resin composition to one side in the thickness direction of the transparent resin film 21, and then curing it after drying as necessary.

[0025] The curable resin composition contains a curable resin. Examples of curable resins include polyester resin, acrylic urethane resin, acrylic resin (excluding acrylic urethane resin), urethane resin (excluding acrylic urethane resin), amide resin, silicone resin, epoxy resin, and melamine resin. Acrylic urethane resin is preferred. The curable resin can be used alone or in combination of two or more types.

[0026] Furthermore, examples of curable resin compositions include ultraviolet-curable resin compositions and thermosetting resin compositions. From the viewpoint of manufacturing efficiency, ultraviolet-curable resin compositions are preferably used as curable resin compositions. A specific example of an ultraviolet-curable resin composition is the hard coat layer forming composition described in Japanese Patent Application Publication No. 2016-179686.

[0027] The curable resin composition preferably contains fine particles in the curable resin layer 22, from the viewpoint of adjusting hardness, surface roughness, refractive index, and providing anti-glare properties. Examples of fine particles include inorganic particles and organic particles. Inorganic particles are preferred. Examples of inorganic particles include inorganic oxide particles. Examples of materials for inorganic oxide particles include silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. Silica is preferred. Examples of materials for organic particles include polymethyl methacrylate, polystyrene, polyurethane, acrylic-styrene copolymer, benzoguanamine, melamine, and polycarbonate.

[0028] The thickness of the cured resin layer 22 is, for example, 1 μm or more, preferably 2 μm or more, more preferably 5 μm or more, and also, for example, 15 μm or less, preferably 12 μm or less, more preferably 10 μm or less.

[0029] If the thickness of the cured resin layer 22 is greater than or equal to the lower limit value, the cured resin layer 22 can be easily formed and its functions can be fully expressed. Also, if the thickness of the cured resin layer is less than or equal to the upper limit value, the anti-reflective film 1 can be made thinner.

[0030] One side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction may be surface-modified to improve adhesion with the intermediate layer 3, which will be described later. Preferably, the surface is surface-modified. Examples of surface modification treatments include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, saponification treatment, and treatment with a coupling agent. Preferably, plasma treatment is used. In other words, one side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction is preferably a plasma-treated surface.

[0031] The total light transmittance (JIS K-7105) of the transparent substrate film 2 is, for example, 80% or more, preferably 85% or more, more preferably 88% or more, even more preferably 90% or more, and also, for example, 100% or less.

[0032] The thickness of the transparent substrate film 2 is not particularly limited, but from the viewpoint of strength and handling, it is, for example, 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and also, for example, 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less.

[0033] <Middle class> The intermediate layer 3 adjusts the difference in refractive index between the transparent substrate film 2 and the anti-reflective layer 4. The intermediate layer 3 is a dry coating layer or a wet coating layer, preferably a dry coating layer, and more preferably a sputtered layer. The intermediate layer 3 is positioned on one side in the thickness direction of the transparent substrate film 2 and on the other side in the thickness direction of the anti-reflective layer 4. Specifically, as shown in Figure 1, the intermediate layer 3 is positioned on one side in the thickness direction of the transparent substrate film 2 (one side in the thickness direction of the cured resin layer 22). In other words, the intermediate layer 3 is in contact with the transparent substrate film 2 (cured resin layer 22).

[0034] For the intermediate layer 3, examples of materials include inorganic materials in the case of a dry coating layer, and a mixture of organic materials and inorganic fine particles in the case of a wet coating layer.

[0035] Examples of inorganic materials include metals, alloys containing two or more metals, metalloids, and oxides of these metals.

[0036] Examples of metals include nickel, chromium, indium, aluminum, tin, gold, silver, platinum, zinc, titanium, tungsten, zirconium, and palladium.

[0037] Silicon is an example of a metalloid.

[0038] Examples of metal oxides include zinc-containing oxides, indium-containing oxides, and antimony-containing oxides. An example of a zinc-containing oxide is aluminum-zinc-silicon composite oxide (Al-Zn-SiO2). x Examples of indium-containing oxides include indium-tin composite oxide (ITO), indium-zinc composite oxide (IZO), indium-gallium composite oxide (IGO), and indium-gallium-zinc composite oxide (IGZO). An example of an antimony-containing oxide is antimony-tin composite oxide (ATO).

[0039] Examples of mixtures of organic materials and inorganic fine particles include a binder resin and inorganic fine particles dispersed in the binder resin.

[0040] Examples of binder resins include cured products of UV-curable resins. Examples of UV-curable resins include epoxy resins, acrylic urethane resins, acrylic resins (excluding acrylic urethane resins), and urethane resins (excluding acrylic urethane resins).

[0041] Examples of inorganic nanoparticles include metal oxide nanoparticles. Examples of metal oxides include zirconium oxide, aluminum oxide, titanium oxide, and silicon oxide. The type and amount of metal oxide nanoparticles are adjusted so that the refractive index when light with a wavelength of 550 nm is incident on the resulting intermediate layer 3 falls within the range described later.

[0042] The ratio of inorganic fine particles to the total amount of binder resin and inorganic fine particles dispersed in the binder resin is, for example, 10% by mass or more, preferably 20% by mass or more. Alternatively, it is, for example, 90% by mass or less, preferably 80% by mass or less. If the amount of inorganic fine particles is too high, the mechanical properties of the resulting anti-reflective film 1 may be insufficient. Conversely, if the amount of inorganic fine particles is too low, the desired reflectance Y may not be obtained.

[0043] Preferably, the material for the intermediate layer 3 is an inorganic oxide. More preferably, an oxide containing at least one element selected from the group consisting of silicon, zinc, aluminum, tin, titanium, indium, and zirconium is used. From the viewpoint of forming the anti-reflective layer 4 without damaging the surface of the cured resin layer 22 by a sputtering method using a HiPIMS power supply described later, an aluminum-zinc-silicon composite oxide (Al-Zn-SiO2) is even more preferably used. x ) are examples. In other words, the intermediate layer 3 contains an inorganic oxide, preferably Al-Zn-SiO x It is a layer.

[0044] Al-Zn-SiO x In this case, the proportion of aluminum oxide to the total amount of aluminum oxide, zinc oxide, and silicon oxide is, for example, 1% by mass or more, preferably 1.5% by mass or more, and more preferably 2% by mass or more. Alternatively, for example, it may be 10% by mass or less, preferably 7% by mass or less, and more preferably 5% by mass or less. If the proportion of aluminum oxide is within the above range, the refractive index when light with a wavelength of 550 nm is incident on the intermediate layer 3 can be adjusted to within the range described later.

[0045] Al-Zn-SiO xIn this case, the ratio of zinc oxide to the total amount of aluminum oxide, zinc oxide, and silicon oxide is, for example, 10% by mass or more, preferably 15% by mass or more, and more preferably 18% by mass or more. Alternatively, for example, it may be 30% by mass or less, preferably 25% by mass or less, and more preferably 22% by mass or less. If the ratio of zinc oxide is within the above range, the refractive index when light with a wavelength of 550 nm is incident on the intermediate layer 3 can be adjusted to within the range described later.

[0046] The refractive index when light with a wavelength of 550 nm is incident on the intermediate layer 3 is a value between the refractive index of the transparent substrate film 2 and the refractive index of the anti-reflective layer 4, and is 1.7 or higher, preferably 1.75 or higher. Also, it is 1.9 or lower, preferably 1.8 or lower. By adjusting the refractive index when light with a wavelength of 550 nm is incident on the intermediate layer 3 to within the above range, the reflectance Y of the anti-reflective film 1 can be lowered over a wide wavelength band.

[0047] The hardness (surface hardness H) of the surface of the intermediate layer 3 at 25°C, measured by nanoindentation, is, for example, 1.05 GPa or higher, preferably 1.1 GPa or higher, more preferably 1.15 GPa or higher, even more preferably 1.2 GPa or higher, and particularly preferably 1.25 GPa or higher. Alternatively, it may be 30 GPa or lower, preferably 20 GPa or lower, and more preferably 15 GPa or lower. If the surface hardness H is within the above range, the anti-reflective layer 4 can be formed on the surface of the cured resin layer 22 without damaging it by sputtering using a HiPIMS power supply, as described later.

[0048] The nanoindentation method will be carried out in accordance with ISO 14577. Furthermore, the same method as in Examples 1 to 4 of Japanese Patent Publication No. 2023-013412 will be employed.

[0049] The thickness of the intermediate layer 3 is, for example, 60 nm or more, preferably 70 nm or more, more preferably 80 nm or more, even more preferably 85 nm or more, and also, for example, 110 nm or less, preferably 100 nm or less, more preferably 95 nm or less, even more preferably 90 nm or less.

[0050] If the thickness of the intermediate layer 3 is within the above range, the anti-reflective layer 4 can be formed on the surface of the cured resin layer 22 without damaging it by sputtering using the HiPIMS power supply described later.

[0051] <Anti-reflection layer> The anti-reflective layer 4 suppresses the reflection intensity of ambient light. The anti-reflective layer 4 is a dry coating layer, preferably a sputtered layer. The anti-reflective layer 4 is positioned on one side in the thickness direction of the intermediate layer 3. In other words, the anti-reflective layer 4 is in contact with the intermediate layer 3.

[0052] The anti-reflective layer 4 includes a laminate comprising a high refractive index layer 41 with a relatively high refractive index and a low refractive index layer 42 with a relatively low refractive index. In the anti-reflective layer 4, the reflection intensity of ambient light is suppressed by interference between reflected light at multiple interfaces in multiple thin layers (high refractive index layer 41 and low refractive index layer 42). Furthermore, in the anti-reflective layer 4, interference that suppresses reflection intensity can be achieved by adjusting the optical film thickness (product of refractive index and thickness) of each thin layer. In addition, the uppermost layer of the anti-reflective layer 4 (the layer on the outermost side in the thickness direction) is preferably the low refractive index layer 42.

[0053] The anti-reflective layer 4 includes two or more laminates 10, each comprising a high refractive index layer 41 and a low refractive index layer 42.

[0054] The anti-reflective layer 4 preferably comprises two laminates 10. Specifically, as shown in Figure 1, the anti-reflective layer 4 comprises a first laminate 10a having a first high refractive index layer 41a (first layer) and a first low refractive index layer 42a (second layer), and a second laminate 10b having a second high refractive index layer 41b (third layer) and a second low refractive index layer 42b (fourth layer).

[0055] More specifically, as shown in Figure 1, the first laminate 10a is placed on one side in the thickness direction of the intermediate layer 3, and the second laminate 10b is placed on one side in the thickness direction of the first laminate 10a.

[0056] In detail, as shown in Figure 1, the first high refractive index layer 41a (first layer) is in contact with the intermediate layer 3. The first low refractive index layer 42a (second layer) is in contact with the first high refractive index layer 41a (first layer). The second high refractive index layer 41b (third layer) is in contact with the first low refractive index layer 42a (second layer). The second low refractive index layer 42b (fourth layer) is in contact with the second high refractive index layer 41b (third layer). The uppermost layer of the anti-reflective layer 4 (the outermost layer in the thickness direction) is preferably the second low refractive index layer 42b (fourth layer).

[0057] The anti-reflective layer 4 includes two or more laminates 10, each comprising a high refractive index layer 41 and a low refractive index layer 42, thereby lowering the reflectance Y of the anti-reflective film 1 over a wide wavelength range.

[0058] The high refractive index layer 41 is a crystalline layer. The high refractive index layer 41 may also contain amorphous regions. Preferably, the high refractive index layer 41 is a layer that does not contain amorphous regions and contains only crystalline regions. The amorphous regions can be identified, for example, by observing the plane direction of the high refractive index layer 41 with a transmission electron microscope.

[0059] The high refractive index layer 41 contains titanium (Ti) oxide. Specifically, the high refractive index layer 41 contains crystals in which a group of Ti2O3 diffraction spots appears in the electron diffraction pattern observed with a transmission electron microscope. In addition to crystals in which a group of Ti2O3 diffraction spots appears, the high refractive index layer 41 may also contain crystals in which other groups of diffraction spots other than Ti2O3 appear. Specifically, the high refractive index layer 41 may contain crystals in which rutile-type TiO2, anatase-type TiO2, brookite-type TiO2, and TiO diffraction spots appear. Preferably, in the high refractive index layer 41, only the group of Ti2O3 diffraction spots appears in the electron diffraction pattern observed with a transmission electron microscope, and no other groups of diffraction spots other than Ti2O3 appear. The crystal structure contained in the high refractive index layer 41 is identified in detail by the analysis of the electron diffraction pattern, as described later.

[0060] The high refractive index layer 41 contains crystals that produce a group of Ti2O3 diffraction spots in the electron diffraction pattern observed with a transmission electron microscope, so that the refractive index when light with a wavelength of 550 nm is incident on the high refractive index layer 41 falls within the range described later.

[0061] Examples of materials for the low refractive index layer 42 include silicon oxide and magnesium fluoride. Silicon oxide is preferred. In other words, the low refractive index layer 42 is preferably a silicon oxide layer. The uppermost layer (the outermost layer in the thickness direction) of the anti-reflective layer 4 is preferably a silicon oxide layer. The silicon oxide layer is a layer made of silicon oxide.

[0062] As described above, the high refractive index layer 41 is a layer with a relatively high refractive index, and the low refractive index layer 42 is a layer with a relatively low refractive index. Specifically, when light with a wavelength of 550 nm is incident on the high refractive index layer 41, the refractive index is greater than 2.50, preferably greater than 2.54, and 2.80 or less, preferably 2.60 or less. When light with a wavelength of 550 nm is incident on the low refractive index layer 42, the refractive index is 1.5 or less. Furthermore, when light with a wavelength of 550 nm is incident on the layer containing the crystal in which the Ti2O3 diffraction spot group appears in the electron diffraction pattern observed with a transmission electron microscope, the refractive index is 2.55. Also, if the high refractive index layer 41 is a layer made of niobium oxide (niobium oxide layer), the refractive index when light with a wavelength of 550 nm is incident on the niobium oxide layer is 2.44. Furthermore, when light with a wavelength of 550 nm is incident on the silicon oxide layer, the refractive index is 1.46. The refractive index of each of the above-mentioned layers when light with a wavelength of 550 nm is incident on them can be determined by measuring the refractive index as described later.

[0063] If the refractive index when light with a wavelength of 550 nm is incident on the high refractive index layer 41 is within the above range, the reflectance Y of the anti-reflective film 1 can be lowered over a wide wavelength band.

[0064] The difference (refractive index difference) between the refractive index when light with a wavelength of 550 nm is incident on the high refractive index layer 41 and the refractive index when light with a wavelength of 550 nm is incident on the low refractive index layer 42 is, for example, 0.87 or more, preferably 0.98 or more, more preferably 1.00 or more, and even more preferably 1.09 or more. If the refractive index difference is within the above range, the reflectance Y of the anti-reflective film 1 can be lowered over a wide wavelength band.

[0065] The thickness of the first high refractive index layer 41a (first layer) is, for example, 10 nm or more, preferably 15 nm or more, more preferably 20 nm or more, even more preferably 25 nm or more, and also, for example, 100 nm or less, preferably 50 nm or less, more preferably 40 nm or less, even more preferably 30 nm or less.

[0066] The thickness of the second high refractive index layer 41b (third layer) is, for example, 10 nm or more, preferably 15 nm or more, more preferably 20 nm or more, even more preferably 25 nm or more, and also, for example, 110 nm or less, preferably 50 nm or less, more preferably 40 nm or less, and even more preferably 30 nm or less.

[0067] The total thickness of the high refractive index layer 41 is, for example, 20 nm or more, preferably 30 nm or more, more preferably 40 nm or more, even more preferably 50 nm or more, and also, for example, 130 nm or less, preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less.

[0068] The thickness of the first low refractive index layer 42a (second layer) is, for example, 10 nm or more, preferably 15 nm or more, more preferably 20 nm or more, even more preferably 25 nm or more, and also, for example, 100 nm or less, preferably 50 nm or less, more preferably 40 nm or less, even more preferably 30 nm or less.

[0069] The thickness of the second low refractive index layer 42b (fourth layer) is, for example, 70 nm or more, preferably 80 nm or more, more preferably 90 nm or more, and also, for example, 130 nm or less, preferably 120 nm or less, more preferably 110 nm or less, and even more preferably 105 nm or less.

[0070] The total thickness of the low refractive index layer 42 is, for example, 100 nm or more, preferably 110 nm or more, more preferably 120 nm or more, even more preferably 125 nm or more, and also, for example, 150 nm or less, preferably 140 nm or less, more preferably 135 nm or less, even more preferably 130 nm or less.

[0071] The optical film thickness (product of refractive index and thickness) of the first high refractive index layer 41a (first layer) and the optical film thickness of the second high refractive index layer 41b (third layer) are, for example, 20 nm or more. Also, for example, they are 100 nm or less.

[0072] The optical film thickness of the first low refractive index layer 42a (second layer) is, for example, 30 nm or more, and for example, 50 nm or less. The optical film thickness of the second low refractive index layer 42b (fourth layer) is, for example, 120 nm or more, and for example, 160 nm or less.

[0073] The total thickness of the anti-reflective layer 4 is, for example, 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, even more preferably 180 nm or more, and also, for example, 300 nm or less, preferably 250 nm or less, more preferably 220 nm or less, even more preferably 200 nm or less.

[0074] If the total thickness of the anti-reflective layer 4 is greater than or equal to the lower limit above, the reflection intensity of ambient light can be suppressed. If the total thickness of the anti-reflective layer 4 is less than or equal to the upper limit above, cracking of the anti-reflective layer 4 can be suppressed.

[0075] The ratio of the thickness of the high refractive index layer 41 (total thickness) to the total thickness of the anti-reflective layer 4 is, for example, 10% or more, preferably 15% or more, more preferably 20% or more, even more preferably 25% or more, and also, for example, 60% or less, preferably 50% or less, and more preferably 35% or less.

[0076] The ratio of the thickness of the low refractive index layer 42 (total thickness) to the total thickness of the anti-reflective layer 4 is, for example, 40% or more, preferably 50% or more, more preferably 60% or more, even more preferably 65% ​​or more, and also, for example, 85% or less, preferably 80% or less, and more preferably 75% or less.

[0077] In other words, the thickness (total thickness) of the high refractive index layer 41 is preferably thinner than the thickness (total thickness) of the low refractive index layer 42.

[0078] One surface of the anti-reflective layer 4 in the thickness direction (the surface on which the anti-fouling layer 5 is placed) may be surface-modified. Preferably, it is surface-treated. Examples of surface modification treatments include corona treatment, plasma treatment, ozone treatment, primer treatment, and coupling agent treatment. Preferably, plasma treatment is used. Examples of plasma treatments include plasma treatment by glow discharge, plasma treatment by a low-inductance antenna, and plasma treatment by atmospheric pressure plasma. Preferably, plasma treatment by a low-inductance antenna and plasma treatment by atmospheric pressure plasma are used, and more preferably, plasma treatment by atmospheric pressure plasma is used. In other words, one surface of the anti-reflective layer 4 in the thickness direction is preferably a plasma-treated surface, and more preferably, a plasma-treated surface by atmospheric pressure plasma.

[0079] The surface roughness Ra (arithmetic mean surface roughness) of one side in the thickness direction of the anti-reflective layer 4 (the side on which the anti-fouling layer 5 is placed) is, for example, 0.5 nm or more, preferably 0.8 nm or more, and for example, 10 nm or less, preferably 8 nm or less.

[0080] The surface roughness Ra can be determined, for example, from an observation image of 1 μm square by an AFM (atomic force microscope).

[0081] <Antifouling layer> The antifouling layer 5 has an antifouling function. The antifouling function of the antifouling layer 5 includes a function of suppressing the adhesion of contaminants such as fingerprints to the film exposed surface when the antireflection film 1 is used, and a function of making it easier to remove the adhered contaminants.

[0082] The antifouling layer 5 is a dry coating layer, preferably a vacuum deposition layer. The antifouling layer 5 is disposed on one side in the thickness direction of the antireflection layer 4. That is, the antifouling layer 5 is in contact with the antireflection layer 4.

[0083] Examples of the material of the antifouling layer 5 include fluorine group-containing organic compounds. As the fluorine group-containing organic compound, preferably, an alkoxysilane compound having a perfluoropolyether group is used. Examples of the alkoxysilane compound having a perfluoropolyether group include a compound represented by the following general formula (1). R 1 -R 2 -X-(CH2) m -Si(OR 3 )3(1) In the general formula (1), R 1 represents a linear or branched fluorinated alkyl group (the number of carbon atoms is, for example, 1 or more and 20 or less) in which one or more hydrogen atoms in the alkyl group are substituted with fluorine atoms, preferably a perfluoroalkyl group in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms.

[0084] R 2This represents a structure containing at least one repeating perfluoropolyether (PFPE) group, preferably a structure containing two repeating PFPE groups. Examples of repeating PFPE groups include repeating linear PFPE groups and repeating branched PFPE groups. Examples of repeating linear PFPE groups include -(OC n F 2n ) p Examples of structures represented by - (where n is an integer between 1 and 20, and p is an integer between 1 and 50; the same applies hereafter) include -(OC(CF3)2) p -A structure represented by -(OCF2CF(CF3)CF2) p Examples of structures represented by - include a repeating structure of a linear PFPE group, and more preferably a repeating structure of -(OCF2) p -and-(OC2F4) p - are listed.

[0085] R 3 This represents an alkyl group having 1 to 4 carbon atoms, preferably a methyl group.

[0086] X represents an ether group, a carbonyl group, an amino group, or an amide group, preferably an ether group.

[0087] m represents an integer greater than or equal to 1. Preferably, m represents an integer less than or equal to 20, more preferably less than or equal to 10, and even more preferably less than or equal to 5.

[0088] Preferably, the compound shown in the following general formula (2) is used as the alkoxysilane compound having a perfluoropolyether group. CF3-(OCF2) q -(OC2F4) r -O-(CH2)3-Si(OCH3)3(2) In general formula (2), q represents an integer between 1 and 50, and r represents an integer between 1 and 50.

[0089] Furthermore, the alkoxysilane compounds having a perfluoropolyether group may be used alone or in combination of two or more types.

[0090] If the material of the antifouling layer 5 contains an alkoxysilane compound having a perfluoropolyether group, and the antifouling layer 5 is a dry coating layer (preferably a vacuum deposition layer), then a high bonding strength of the antifouling layer 5 to the anti-reflective layer 4 can be ensured. Therefore, the peel resistance of the antifouling layer 5 can be ensured, which helps maintain the antifouling function of the antifouling layer 5.

[0091] The water contact angle (pure water contact angle) of the surface of the antifouling layer 5 is, for example, 110° or more, preferably 111° or more, more preferably 112° or more, and even more preferably 113° or more. If the water contact angle on the surface is above the above lower limit, high antifouling performance can be achieved in the antifouling layer 5. The water contact angle is, for example, 130° or less. The water contact angle is determined by forming a water droplet (pure water droplet) with a diameter of 2 mm or less on the surface (exposed surface) of the antifouling layer 5 and measuring the contact angle of the water droplet with respect to the surface.

[0092] The thickness of the anti-fouling layer 5 is, for example, 1 nm or more, preferably 3 nm or more, more preferably 5 nm or more, and even more preferably 7 nm or more. Alternatively, it may be 20 nm or less, preferably 15 nm or less, and more preferably 10 nm or less.

[0093] It is preferable that the difference in refractive index between the antifouling layer 5 and the layer in contact with it is small. Specifically, when the antifouling layer 5 and the low refractive index layer 42 (silicon oxide layer) are in contact, the refractive index when light with a wavelength of 550 nm is incident on the antifouling layer 5 is, for example, 1.6 or less, preferably 1.55 or less, and more preferably 1.5 or less.

[0094] The surface roughness Ra (arithmetic mean surface roughness) of one side (exposed surface) in the thickness direction of the antifouling layer 5 is, for example, 1 nm or more, preferably 2 nm or more, and for example, 10 nm or less, preferably 8 nm or less, and more preferably 6 nm or less.

[0095] The surface roughness Ra can be determined, for example, from a 1 μm square observation image obtained using an AFM (atomic force microscope).

[0096] <Effects and Effects> When light with a wavelength of 380 to 780 nm is incident on the anti-reflective film 1, the wavelength range in which the spectral reflectance of the anti-reflective film 1 becomes 1% or less is 280 nm or higher, preferably 320 nm or higher, and more preferably 350 nm or higher.

[0097] The spectral reflectance of the anti-reflective film 1 is determined by spectral reflectance evaluation, which will be described later.

[0098] When light with a wavelength of 380 to 780 nm is incident on the anti-reflective film 1, the reflectance Y of the reflected light in the CIE-XYZ color system is 0.4% or less, preferably 0.3% or less, and more preferably 0.25% or less.

[0099] The reflectance Y of the anti-reflective film 1 is determined by the calculation of reflectance Y described later.

[0100] When light with a wavelength of 380 to 780 nm is incident on the anti-reflective film 1, the value of a* in the CIE-Lab color system, obtained based on the CIE-XYZ color system of the reflected light, is, for example, 5 or less, preferably 4 or less, and more preferably 3 or less.

[0101] The value of a* for anti-reflective film 1 is determined by the calculation formulas (3) to (5) described later for the reflective hue.

[0102] The thickness of the anti-reflective film 1 is, for example, 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, and also, for example, 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less.

[0103] 2. Method for manufacturing anti-reflective film An embodiment of the method for manufacturing the anti-reflective film of the present invention will be described with reference to Figures 2A to 2E.

[0104] A method for manufacturing the anti-reflective film 1 includes, for example, a preparation step of preparing a transparent resin film 21 (Figure 2A), a cured resin layer formation step of forming a cured resin layer 22 on the transparent resin film 21 (Figure 2B), an intermediate layer formation step of forming an intermediate layer 3 on the cured resin layer 22 (Figure 2C), an anti-reflective layer formation step of forming an anti-reflective layer 4 on the intermediate layer 3 (Figure 2D), and an anti-fouling layer formation step of forming an anti-fouling layer 5 on the anti-reflective layer 4 (Figure 2E).

[0105] <Preparation Steps> In the preparation step, a transparent resin film 21 is prepared as shown in Figure 2A.

[0106] <Cured resin layer formation process> In the cured resin layer formation process, as shown in Figure 2B, a cured resin layer 22 is formed on one side of the transparent resin film 21 in the thickness direction. Specifically, the above-mentioned curable resin composition is applied to one side of the transparent resin film 21 in the thickness direction to form a coating film, and then this coating film is cured to form the cured resin layer 22.

[0107] The curable resin composition may further contain a photopolymerization initiator, a leveling agent, and a solvent (diluent).

[0108] If the curable resin composition contains a solvent, the coating on the transparent resin film 21 is dried after the curable resin composition is applied.

[0109] The drying temperature is, for example, 50°C to 120°C. The drying time is, for example, 10 seconds to 10 minutes.

[0110] When the curable resin composition includes an ultraviolet-curable resin, the coating on the transparent resin film 21 is cured by ultraviolet irradiation. Examples of ultraviolet irradiation light sources include high-pressure mercury lamps and LED lights. Preferably, a high-pressure mercury lamp is used. The cumulative amount of ultraviolet irradiation is, for example, 100 mJ / cm². 2 ~500mJ / cm 2 That is the case.

[0111] In this way, a transparent substrate film 2 is obtained having a cured resin layer 22 on one side in the thickness direction of the transparent resin film 21.

[0112] <Intermediate layer formation process> In the intermediate layer formation process, as shown in Figure 2C, the material for the intermediate layer 3 described above is deposited on one side in the thickness direction of the transparent substrate film 2 (cured resin layer 22) to form the intermediate layer 3.

[0113] Methods for forming the intermediate layer 3 include dry coating and wet coating. Examples of dry coating methods include vacuum deposition, sputtering, and ion plating. Sputtering is preferred. Examples of wet coating methods include gravure coating, reverse coating, and die coating.

[0114] Examples of sputtering methods include two-electrode sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering. Preferably, reactive sputtering using the magnetron sputtering method is used.

[0115] In the sputtering method, a sputtering deposition apparatus capable of performing the film deposition process in a roll-to-roll manner can be used. In the intermediate layer formation process, when using a roll-to-roll sputtering deposition apparatus, the transparent substrate film 2, which serves as the work film W, is moved from the feed roll to the winding roll of the sputtering deposition apparatus, and the material for the intermediate layer 3 is deposited on one side in the thickness direction of the transparent substrate film 2 to form the intermediate layer 3. The travel speed of the work film W (transparent substrate film 2) is, for example, 0.1 to 10.0 m / min.

[0116] In the sputtering method, specifically, a sputtering gas (inert gas) is introduced into the deposition chamber under vacuum conditions, and a negative voltage is applied to a target made of the aforementioned intermediate layer 3 material inside the deposition chamber. This generates a glow discharge, ionizing the gas atoms, and these gas ions collide with the target surface at high speed, ejecting the target material from the target surface. The ejected target material is then deposited on one side in the thickness direction of the work film W (transparent substrate film 2). As the target material, a sintered body of the aforementioned intermediate layer 3 material is used. Examples of sintered bodies of the intermediate layer 3 material include sintered bodies of aluminum oxide, zinc oxide, and silicon oxide.

[0117] Examples of sputtering gases include argon, krypton, xenon, and mixtures thereof, with argon being preferred. In reactive sputtering, for example, oxygen as a reactive gas is introduced into the deposition chamber in addition to the sputtering gas. That is, the intermediate layer 3 is deposited in the presence of an inert gas and oxygen gas.

[0118] The achievable vacuum level in the deposition chamber is, for example, 1.0 × 10⁻⁶. -4 It is below Pa.

[0119] In the reactive sputtering method, the volume ratio of oxygen gas to the total volume of sputtering gas and oxygen gas (reactive gas) introduced into the deposition chamber is, for example, 0.01% to 30% by volume, preferably 0.1% to 20% by volume, more preferably 1% to 10% by volume, and even more preferably 2% to 5% by volume.

[0120] The film formation temperature (the temperature of the transparent substrate film 2 when the intermediate layer 3 is formed) is, for example, -50.0°C to 30.0°C, preferably -30.0°C to 20.0°C, more preferably -20.0°C to 10.0°C, and even more preferably -15.0°C to 0.0°C.

[0121] The atmospheric pressure inside the deposition chamber (the atmospheric pressure inside the deposition chamber when sputtering gas and oxygen are introduced) is, for example, 0.01 Pa to 5.0 Pa, preferably 0.05 Pa to 3.0 Pa, more preferably 0.10 Pa to 1.0 Pa, and even more preferably 0.15 Pa to 0.80 Pa.

[0122] Examples of power supplies for applying voltage to the target include DC power supplies, AC power supplies, MF power supplies, and RF power supplies. An MFAC power supply, which combines an MF power supply and an AC power supply, may also be used. Preferably, an MFAC power supply is used.

[0123] The discharge power is, for example, 1kW to 20kW, preferably 3kW to 10kW.

[0124] The horizontal magnetic field strength above the target is, for example, 10 mT to 100 mT.

[0125] In the wet coating method, a coating liquid (varnish) containing the material for the intermediate layer 3 is applied to one side in the thickness direction of the transparent substrate film 2 to form a coating film, and then the intermediate layer 3 is formed by drying and curing this coating film. Examples of materials for the intermediate layer 3 include a mixture of organic materials and inorganic fine particles, and more specifically, a binder resin and inorganic fine particles dispersed in the binder resin.

[0126] The drying temperature is, for example, 60°C to 120°C. The drying time is, for example, 10 to 60 minutes.

[0127] The coating on the transparent substrate film 2 after drying is cured by ultraviolet irradiation. Examples of ultraviolet irradiation light sources include high-pressure mercury lamps and LED lights. Preferably, high-pressure mercury lamps are used. The cumulative irradiation amount of ultraviolet light is, for example, 100 mJ / cm². 2 ~500mJ / cm 2 That is the case.

[0128] As described above, an intermediate layer 3 is formed on one side of the transparent substrate film 2 in the thickness direction.

[0129] By forming an intermediate layer 3 on one side in the thickness direction of the transparent substrate film 2 (cured resin layer 22), an anti-reflective layer 4 can be formed without damaging the surface of the cured resin layer 22 by a sputtering method using a HiPIMS power supply, as described later.

[0130] Furthermore, one side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction may be plasma-treated before the intermediate layer formation process. A roll-to-roll sputtering deposition apparatus can be used for the plasma treatment. In other words, the plasma treatment and the formation of the intermediate layer 3 can be carried out continuously.

[0131] Examples of plasma treatments include plasma treatment by glow discharge, plasma treatment by a low-inductance antenna, and plasma treatment by atmospheric pressure plasma. Plasma treatment by glow discharge is preferred. The following conditions can be adjusted as appropriate depending on the plasma treatment method.

[0132] Specifically, under vacuum conditions, a sputtering gas (inert gas) and / or a reactive gas are introduced into the plasma processing chamber of the sputtering deposition apparatus, and a voltage is applied to generate plasma, thereby plasma-treating one side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction.

[0133] Examples of sputtering gases used in plasma processing include nitrogen, argon, krypton, xenon, and mixtures thereof. Examples of reactive gases used in plasma processing include oxygen.

[0134] The achievable vacuum level in the plasma processing chamber is, for example, 1.0 × 10⁻⁶. -4 It is below Pa.

[0135] The atmospheric pressure inside the plasma processing chamber (the atmospheric pressure inside the plasma processing chamber when sputtering gas and / or reactive gas are introduced) is, for example, 0.01 Pa to 5.0 Pa, preferably 0.05 Pa to 3.0 Pa, more preferably 0.10 Pa to 1.0 Pa, and even more preferably 0.15 Pa to 0.80 Pa.

[0136] The discharge power in the plasma processing chamber is, for example, 0.01 kW to 10 kW, preferably 0.05 kW to 5 kW.

[0137] <Anti-reflection layer formation process> In the anti-reflective layer formation process, as shown in Figure 2D, an anti-reflective layer 4 is formed on one side of the intermediate layer 3 in the thickness direction.

[0138] One method for forming the anti-reflective layer 4 is a dry coating method. Examples of dry coating methods include vacuum deposition, sputtering, and ion plating. Sputtering is preferred.

[0139] Examples of sputtering methods include two-electrode sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering. Preferably, reactive sputtering using the magnetron sputtering method is used.

[0140] In the sputtering method, a sputtering deposition apparatus capable of performing the film deposition process in a roll-to-roll manner can be used. When using a roll-to-roll sputtering deposition apparatus in the anti-reflective layer formation process, a transparent substrate film 2 with an intermediate layer 3, which serves as the work film W, is moved from the feed roll to the winding roll of the sputtering deposition apparatus, and the laminate material (specifically, titanium oxide and silicon oxide) is sequentially deposited on one side in the thickness direction of the intermediate layer 3 to form a laminate. The travel speed of the work film W (transparent substrate film 2 with intermediate layer 3) is, for example, 0.1 to 10.0 m / min.

[0141] In the sputtering method used in the anti-reflective layer formation process, a sputtering deposition apparatus is preferably used that has multiple deposition chambers arranged sequentially along the travel path of the work film W (transparent substrate film 2 having an intermediate layer 3), and the first to fourth layers are formed in order.

[0142] In the sputtering method, specifically, a sputtering gas (inert gas) is introduced into the deposition chamber of the sputtering deposition apparatus under vacuum conditions, while a negative voltage is applied to a target made of the anti-reflective layer 4 material described above inside the deposition chamber. This generates a glow discharge, ionizing the gas atoms, and these gas ions collide with the target surface at high speed, ejecting the target material from the target surface, and depositing the ejected target material sequentially in the thickness direction.

[0143] Examples of sputtering gases include argon, krypton, xenon, and mixtures thereof, with argon being preferred. In reactive sputtering, for example, oxygen is introduced into the deposition chamber as a reactive gas in addition to the sputtering gas.

[0144] In the deposition of the first layer, titanium is used as the target material.

[0145] In the deposition of the first layer, the achievable vacuum level in the deposition chamber before sputtering and the atmospheric pressure in the deposition chamber (atmospheric pressure in the deposition chamber when sputtering gas and / or oxygen are introduced) are the same as those in the intermediate layer formation process described above.

[0146] In the deposition of the first layer, the volume ratio of oxygen gas to the total volume of sputtering gas and oxygen gas (reactive gas) introduced into the deposition chamber is, for example, 0.1% to 30% by volume, preferably 1% to 20% by volume, and more preferably 5% to 10% by volume.

[0147] In the deposition of the first layer, the deposition temperature (temperature of the roll supporting the transparent substrate film 2) is, for example, 50.0°C to 200°C, preferably 55°C to 180°C, more preferably 60°C to 150°C, and even more preferably 80°C to 120°C.

[0148] In the deposition of the first layer, power supplies for applying voltage to the target include, for example, DC power supplies, AC power supplies, MF power supplies, RF power supplies, and high-power impulse magnetron sputtering (HiPIMS) power supplies. The power supply may be a combination of an MF power supply and an AC power supply, or an MFAC power supply may be used. A HiPIMS power supply is preferred.

[0149] In the sputtering method using a HiPIMS power supply, a high-density plasma can be generated by applying a voltage to the target at a predetermined frequency and pulse width. This high-density plasma ionizes gas atoms, causing the gas ions to collide with the target surface at high speed, ejecting the target material from the target surface, and then depositing the ejected target material sequentially in the thickness direction.

[0150] By using a sputtering method with a HiPIMS power supply, a layer containing crystals in which a group of Ti2O3 diffraction spots appear in the electron diffraction pattern observed with a transmission electron microscope can be obtained. Furthermore, an anti-reflective layer 4 can be deposited without damaging the surface of the cured resin layer 22.

[0151] When depositing the first layer using a HiPIMS power supply, the discharge voltage is, for example, 1000V to 2000V, preferably 1500V to 1800V. If the discharge voltage is within the above range, a layer containing crystals in which a group of Ti2O3 diffraction spots appears in the electron diffraction pattern observed with a transmission electron microscope can be obtained.

[0152] When using the HiPIMS power supply during the deposition of the first layer, the frequency is, for example, 150Hz to 300Hz, preferably 200Hz to 250Hz. If the frequency is within the above range, a layer containing crystals in which a group of Ti2O3 diffraction spots appears in the electron diffraction pattern observed with a transmission electron microscope can be obtained.

[0153] When using the HiPIMS power supply during the deposition of the first layer, the pulse width is, for example, 10 μs to 100 μs, preferably 20 μs to 50 μs. If the pulse width is within the above range, a layer containing crystals in which a group of Ti2O3 diffraction spots appears in the electron diffraction pattern observed with a transmission electron microscope can be obtained.

[0154] During the deposition of the first layer, the horizontal magnetic field strength on the target is the same as that used in the intermediate layer formation process described above.

[0155] In the deposition of the second layer, silicon is used as the target material.

[0156] In the deposition of the second layer, the achievable vacuum level in the deposition chamber before sputtering and the atmospheric pressure in the deposition chamber (atmospheric pressure in the deposition chamber when sputtering gas and / or oxygen are introduced) are the same as those in the intermediate layer formation process described above.

[0157] In the deposition of the second layer, the volume ratio of oxygen gas to the total volume of sputtering gas and oxygen gas (reactive gas) introduced into the deposition chamber is, for example, 5% to 50% by volume, preferably 10% to 40% by volume, and more preferably 20% to 35% by volume.

[0158] In the deposition of the second layer, the deposition temperature (temperature of the roll supporting the transparent substrate film 2) is, for example, 50.0°C to 200°C, preferably 55°C to 180°C, more preferably 60°C to 150°C, and even more preferably 80°C to 120°C.

[0159] In the deposition of the second layer, power supplies for applying voltage to the target include, for example, DC power supplies, AC power supplies, MF power supplies, RF power supplies, and high-power impulse magnetron sputtering (HiPIMS) power supplies. The power supply may be a combination of an MF power supply and an AC power supply, or an MFAC power supply may be used. Preferably, an MFAC power supply is used.

[0160] When using an MFAC power supply during the deposition of the second layer, the discharge power is, for example, 10kW to 100kW, preferably 20kW to 50kW.

[0161] During the deposition of the second layer, the horizontal magnetic field strength on the target is the same as in the intermediate layer formation process described above.

[0162] The third layer is deposited under the same conditions as the first layer described above.

[0163] The fourth layer is deposited under the same conditions as the second layer described above.

[0164] As described above, an anti-reflective layer 4 is formed on one side of the intermediate layer 3 in the thickness direction.

[0165] Furthermore, after the anti-reflective layer formation process, one side of the anti-reflective layer 4 in the thickness direction may be plasma-treated. Plasma treatment may be performed using a roll-to-roll sputtering deposition apparatus or a direct-type atmospheric pressure plasma surface treatment apparatus. When a roll-to-roll sputtering deposition apparatus is used for plasma treatment, the formation of the anti-reflective layer 4 and the plasma treatment can be performed continuously.

[0166] Examples of plasma treatment methods include plasma treatment using glow discharge, plasma treatment using a low-inductance antenna, and plasma treatment using atmospheric pressure plasma. Depending on the plasma treatment method, the following conditions can be adjusted as appropriate.

[0167] Specifically, in the case of plasma processing by glow discharge and plasma processing by a low-inductance antenna, a voltage is applied while introducing a sputtering gas (inert gas) and / or a reactive gas under vacuum conditions into the plasma processing chamber of the sputtering deposition apparatus, generating plasma and plasma processing one side in the thickness direction of the anti-reflective layer 4. The running speed of the work film W (transparent substrate film 2 comprising the anti-reflective layer 4 and the intermediate layer 3) is, for example, 0.1 to 10.0 m / min.

[0168] Furthermore, in the case of plasma treatment using atmospheric pressure plasma, for example, plasma treatment can be performed using a direct-type atmospheric pressure plasma surface treatment apparatus. The direct-type atmospheric pressure plasma surface treatment apparatus comprises a plasma treatment chamber, a flat discharge electrode connected to an AC power supply within the plasma treatment chamber, and a flat ground electrode positioned opposite the discharge electrode at a distance within the plasma treatment chamber and grounded. In the direct-type atmospheric pressure plasma surface treatment apparatus, an inert gas and / or reactive gas are introduced into the plasma treatment chamber under atmospheric pressure, a voltage is applied, plasma is generated, and one side in the thickness direction of the anti-reflective layer 4 is plasma treated. The running speed of the work film W (transparent substrate film 2 comprising the anti-reflective layer 4 and the intermediate layer 3) (the speed at which the ground electrode moves) is, for example, 0.1 to 10.0 m / min.

[0169] Examples of sputtering gases used in plasma processing include nitrogen, argon, krypton, xenon, and mixtures thereof. Examples of reactive gases used in plasma processing include oxygen.

[0170] The achievable vacuum level in the plasma processing chamber is, for example, 1.0 × 10⁻⁶. -4The pressure is below Pa. Note that plasma treatment using atmospheric pressure plasma is performed under atmospheric pressure.

[0171] The atmospheric pressure inside the plasma processing chamber (the atmospheric pressure inside the plasma processing chamber when sputtering gas and / or reactive gas are introduced) is, for example, 0.01 Pa to 5.0 Pa, preferably 0.05 Pa to 3.0 Pa, more preferably 0.10 Pa to 1.0 Pa, and even more preferably 0.15 Pa to 0.80 Pa. Plasma processing using atmospheric pressure plasma is carried out under atmospheric pressure.

[0172] The discharge power in the plasma processing chamber is adjusted as appropriate depending on the plasma processing method, and is, for example, 0.1 kW to 30 kW, preferably 0.2 kW to 10 kW.

[0173] <Stain-resistant layer formation process> In the antifouling layer formation process, as shown in Figure 2E, the antifouling layer 5 is formed on one side in the thickness direction of the antireflective layer 4.

[0174] Methods for forming the antifouling layer 5 include, for example, a dry coating method and a wet coating method. Preferably, from the viewpoint of production efficiency, a dry coating method is preferred. Examples of dry coating methods include vacuum deposition, sputtering, and CVD, with vacuum deposition being preferred. Examples of wet coating methods include coating methods.

[0175] In the vacuum deposition method, the material of the antifouling layer 5 described above is dried and solidified, and then used as the deposition source.

[0176] The deposition temperature is, for example, 150°C to 500°C, preferably 200°C to 300°C.

[0177] For example, the achievable vacuum level in the deposition chamber during vapor deposition is 1.0 × 10⁻⁶. -4 It is below Pa.

[0178] In this way, an anti-fouling layer 5 is formed on one side of the anti-reflective layer 4 in the thickness direction.

[0179] In this manner, the anti-reflective film 1 is manufactured.

[0180] 3. Variant <Examples of anti-reflective film> In Figure 1, the transparent substrate film 2 consists of a transparent resin film 21 and a cured resin layer 22 arranged on one side of the transparent resin film 21 in the thickness direction, but is not limited to this.

[0181] In other words, the transparent substrate film 2 may consist only of the transparent resin film 21. Furthermore, the cured resin layer 22 may be arranged on both sides of the transparent resin film 21, one side in the thickness direction and the other side.

[0182] Furthermore, in Figure 1, the anti-reflective layer 4 is a laminate consisting of a first high refractive index layer 41a, a first low refractive index layer 42a, a second high refractive index layer 41b, and a second low refractive index layer 42b, but is not limited to this.

[0183] In other words, the anti-reflective layer 4 is not particularly limited as long as it includes two or more laminates 10 each comprising a high refractive index layer 41 and a low refractive index layer 42. Specifically, the number of layers and the layering order of the anti-reflective layer 4 are not particularly limited.

[0184] In other words, the anti-reflective layer 4 may include, for example, three or more laminates 10 each comprising a high refractive index layer 41 and a low refractive index layer 42.

[0185] Furthermore, the anti-reflective layer 4 may, for example, have a low refractive index layer 42 arranged on one side in the thickness direction of the intermediate layer 3, and a high refractive index layer 41 arranged on one side in the thickness direction of the low refractive index layer 42. Specifically, the first low refractive index layer 42a may be in contact with the intermediate layer 3, the first high refractive index layer 41a may be in contact with the first low refractive index layer 42a, the second low refractive index layer 42b may be in contact with the first high refractive index layer 41a, and the second high refractive index layer 41b may be in contact with the second low refractive index layer 42b.

[0186] Furthermore, in Figure 1, the anti-reflective film 1 includes an anti-fouling layer 5, but is not limited to this.

[0187] In other words, the anti-reflective film 1 does not necessarily have to include the anti-fouling layer 5, as shown in Figure 3, for example. [Examples]

[0188] The present invention will be further described below with reference to examples, comparative examples, and reference examples. However, the present invention is not limited to the examples, comparative examples, and reference examples. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical properties, and parameters used in the following description may be replaced with the upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than") of the corresponding blending ratios (content ratios), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above.

[0189] Example 1 <Manufacturing of anti-reflective film> An anti-reflective film was fabricated as shown below.

[0190] [Fabrication of transparent substrate films] A mixture was prepared by mixing 100 parts by mass of a butyl acetate solution of UV-curable acrylic urethane resin (product name: Luxidia 17-806, solids content: 80% by mass, manufactured by DIC Corporation), 5 parts by mass of a photopolymerization initiator (product name: IRGACURE 906, manufactured by BASF Corporation), and 0.01 parts by mass of a leveling agent (product name: GRANDIC PC4100, manufactured by DIC Corporation). Subsequently, the solids content of the mixture was adjusted to 36% by mass by adding a mixed solvent of cyclopentanone (CPN) and propylene glycol monomethyl ether (PGM) (mass ratio of CPN to PGM: 45:55) to obtain a curable resin composition. This curable resin composition was applied to one side in the thickness direction of an 80 μm thick triacetylcellulose (TAC) film (product name: KC8UA, manufactured by Konica Minolta Advanced Layer Corporation) so that the thickness after drying was 7 μm, and it was dried at 90°C for 1 minute. Subsequently, a high-pressure mercury lamp was used to obtain a wavelength of 365 nm and an integrated light intensity of 300 mJ / cm². 2 The coating layer was cured by irradiation with ultraviolet light to form a cured resin layer. In this way, a transparent substrate film having a cured resin layer on a transparent resin film was obtained.

[0191] [Formation of the intermediate layer] First, one side of the transparent substrate film in the thickness direction (one side in the thickness direction of the cured resin layer) was plasma-treated. A roll-to-roll sputtering deposition system was used for the plasma treatment. The achievable vacuum in the plasma treatment chamber of the sputtering deposition system was 1.0 × 10⁻⁶. -4 After evacuating the chamber to a vacuum of 0.5 Pa, argon was introduced as a sputtering gas (inert gas) into the plasma treatment chamber. The atmospheric pressure in the plasma treatment chamber was set to 0.5 Pa, and the discharge power was set to 0.15 kW. While transporting the transparent substrate film, one side of the cured resin layer in the thickness direction was treated with a glow discharge plasma.

[0192] Next, by reactive sputtering, an 86 nm thick layer of Al-Si-ZnO is applied to one side of the transparent substrate film in the thickness direction (one side in the thickness direction of the cured resin layer). xA layer (intermediate layer) was formed. A roll-to-roll sputter deposition system was used to form the intermediate layer. The details of the sputter deposition conditions used for forming the intermediate layer are shown below.

[0193] The maximum vacuum level achieved in the deposition chamber of the sputter deposition apparatus is 1.0 × 10⁻⁶. -4 After evacuating the chamber to a vacuum of 0.2 Pa, argon as the sputtering gas and oxygen as the reactive gas were introduced into the deposition chamber, and the atmospheric pressure inside the chamber was set to 0.2 Pa. The volume ratio of argon gas to oxygen gas was introduced into the deposition chamber to 100:4. The target of the sputtering apparatus was a sintered body of aluminum oxide, zinc oxide, and silicon oxide, containing aluminum oxide, silicon oxide, and zinc oxide in a mass ratio of 3:20:77. An MFAC power supply was used to apply voltage to the target, with a discharge power of 6.0 kW, and the deposition temperature (temperature of the roll supporting the transparent substrate film on which the intermediate layer is formed) was set to -5°C.

[0194] In this way, an intermediate layer was formed on one side of the transparent substrate film in the thickness direction (one side of the cured resin layer in the thickness direction).

[0195] [Formation of anti-reflective layer] Next, a laminate (anti-reflective layer) was formed on one side of the thickness direction of the intermediate layer by reactive sputtering, with a titanium oxide layer (1st layer), a silicon oxide layer (2nd layer), a titanium oxide layer (3rd layer), and a silicon oxide layer (4th layer) arranged sequentially toward one side in the thickness direction. A roll-to-roll magnetron sputtering apparatus was used to form the anti-reflective layer. Details of the sputtering conditions used to form the anti-reflective layer are shown below.

[0196] In the deposition of the first layer, the achievable vacuum level in the deposition chamber of the sputter deposition apparatus is 1.0 × 10⁻⁶. -4After evacuating the chamber to a vacuum of 0.2 Pa, argon (as a sputtering gas, or inert gas) and oxygen (as a reactive gas) were introduced into the deposition chamber, and the atmospheric pressure inside the chamber was set to 0.2 Pa. The volume ratio of argon to oxygen gases introduced into the deposition chamber was 100:8. Titanium was used as the target for the sputtering apparatus. A HiPIMS power supply (product name: TruPlasma Highpulse 4002 G2, manufactured by TRUMPF) was used as the power supply for applying voltage to the target, with a discharge voltage of 1700V, a frequency of 210Hz, a pulse width of 35us, and a deposition temperature (the temperature of the roll supporting the transparent substrate film with an intermediate layer on which the anti-reflective layer is formed) of 100°C.

[0197] In the deposition of the second layer, the achievable vacuum level in the deposition chamber of the sputter deposition apparatus is 1.0 × 10⁻⁶. -4 After evacuating the chamber to a vacuum of 0.2 Pa, argon (as a sputtering gas, or inert gas) and oxygen (as a reactive gas) were introduced into the deposition chamber, and the atmospheric pressure inside the chamber was set to 0.2 Pa. The volume ratio of argon to oxygen gases introduced into the deposition chamber was 100:30. Silicon was used as the target for the sputtering apparatus. An MFAC power supply was used to apply voltage to the target, with a discharge power of 25 kW, and the deposition temperature (the temperature of the transparent substrate film with an intermediate layer on which the anti-reflective layer is formed) was set to 100°C.

[0198] For the deposition of the third layer, the same conditions as those used for the deposition of the first layer were applied.

[0199] For the deposition of the fourth layer, the same conditions as those used for the deposition of the second layer were applied.

[0200] In this way, a laminate (anti-reflective layer) is formed on one side in the thickness direction of the intermediate layer, with a titanium oxide layer (1st layer), a silicon oxide layer (2nd layer), a titanium oxide layer (3rd layer), and a silicon oxide layer (4th layer) arranged in order toward one side in the thickness direction.

[0201] [Formation of a stain-resistant layer] Subsequently, an 8 nm thick antifouling layer was formed on one side of the anti-reflective layer in the thickness direction (one side of the silicon oxide layer (fourth layer) in the thickness direction) using vacuum deposition. During the deposition of the antifouling layer, the vacuum level achieved in the vacuum deposition chamber was 1.0 × 10⁻⁶. -4 After evacuating the crucible to a vacuum of Pa, antifouling material A (product name: SHIN-ETSU SUBELYN KY1903-1, active ingredient: alkoxysilane compound having a perfluoropolyether group, manufactured by Shin-Etsu Chemical Co., Ltd.) was placed in the crucible and heated under vacuum. The crucible was preheated beforehand, and antifouling material A was dried before being used for film formation. The heating temperature during film formation was 260°C.

[0202] Specifically, the active ingredient in the antifouling layer material A is a compound having a perfluoropolyether skeleton represented by the chemical formula (1) described above.

[0203] In this way, an antifouling layer was formed on one side in the thickness direction of the anti-reflective layer (one side in the thickness direction of the silicon oxide layer (fourth layer)).

[0204] The anti-reflective film was formed in the manner described above.

[0205] Comparative Example 1 The anti-reflective film of Comparative Example 1 was fabricated in the same manner as the anti-reflective film of Example 1, except that niobium was used as the target of the sputtering apparatus for the deposition of the first and third layers, an MFAC power supply was used as the power supply for applying voltage to the target, the discharge power was set to 25 kW, and the deposition temperature (the temperature of the transparent substrate film with an intermediate layer on which the anti-reflective layer is formed) was set to 100°C.

[0206] Comparative Example 2 In the deposition of the first and third layers, an MFAC power supply was used as the power source for applying voltage to the target, with a discharge power of 25 kW, and the deposition temperature (temperature of the transparent substrate film with an intermediate layer on which the anti-reflective layer is formed) was set to 100°C. Except for these other conditions, the anti-reflective film of Comparative Example 2 was fabricated in the same manner as the anti-reflective film of Example 1.

[0207] Comparative Example 3 The anti-reflective film of Comparative Example 3 was prepared in the same manner as the anti-reflective film of Comparative Example 1, except that an intermediate layer was not formed.

[0208] Comparative Example 4 The procedure was carried out in the same manner as the anti-reflective film of Example 1, except that an intermediate layer was not formed.

[0209] Comparative Example 5 The anti-reflective film of Comparative Example 5 was prepared in the same manner as the anti-reflective film of Comparative Example 1, except that the third and fourth layers were not formed.

[0210] Comparative Example 6 The anti-reflective film of Comparative Example 6 was prepared in the same manner as the anti-reflective film of Comparative Example 2, except that the third and fourth layers were not formed.

[0211] Comparative Example 7 The anti-reflective film of Comparative Example 7 was prepared in the same manner as the anti-reflective film of Example 1, except that the third and fourth layers were not formed.

[0212] <Rating> [Measuring the refractive index] The anti-reflective films obtained in each example and comparative example were measured using a spectroscopic ellipsometer (product name: RC2, JAWoollam Japan). After measurement, the refractive index was determined by fitting the measured spectra of the polarization analysis parameters ψ and Δ with the simulation spectra calculated from the optical model. As the optical model, a laminated structure consisting of a film, an intermediate layer, a titanium oxide layer, a silicon oxide layer, a titanium oxide layer, and a silicon oxide layer was set up, and each layer was fitted using Cauchy's dispersion formula, and the refractive index (n) when light with a wavelength of 550 nm was incident on each layer was measured. The results are shown in Table 1.

[0213] [Spectral reflectance evaluation] The anti-reflective films obtained in the examples and comparative examples were cut into 50 mm squares to serve as evaluation samples. The spectral reflectance (wavelength: 380-780 nm, incident angle: 5°) of the evaluation samples, which were attached to a black acrylic plate via adhesive, was measured using a spectrophotometer (product name: UH-4150, Hitachi High-Tech Corporation). The wavelength range (unit: nm) in which the obtained spectral reflectance was 1% or less was determined. The results are shown in Table 1.

[0214] [Calculation of reflectance Y] Using the spectral reflectances at wavelengths of 380-780 nm measured above, and the relative spectral distribution of the CIE standard illuminant D65, the luminous reflectance (reflectance Y) of the object color due to reflection in the XYZ color system defined in JIS Z 8701 was calculated.

[0215] [Reflection Hue] Based on the XYZ color system obtained from the reflected hue, a* and b* in the CIE-Lab color system were determined by conversion using the following formulas (1) to (3). The results are shown in Table 1.

number

number

number

[0216] [Analysis of electron diffraction patterns] For the anti-reflective layers of the anti-reflective films obtained in each example and comparative example, cross-sections were prepared at specified locations using the FIB microsampling method, and the cross-sections were observed with an FE-TEM (product name: JEM-2800, manufactured by JEOL Corporation). The thickness (d) of each layer from the first to the fourth layer was measured. Subsequently, electron diffraction patterns were obtained from the cross-sections of the titanium oxide layers (first and third layers). The constituent layers of the titanium oxide layers (first and third layers) were then analyzed based on the interplanar spacing of the electron diffraction spots and the interplanar spacing on the ICDD data, and the presence or absence of Ti2O3 diffraction patterns was investigated. The results are shown in Table 1.

[0217] [Table 1] [Explanation of Symbols]

[0218] 1. Anti-reflective film 2 Transparent base film 3. Middle Class 4 Anti-reflection layer 5. Anti-fouling layer 10 Laminate 10a First Laminate 10b Second layer 21 Transparent resin film 22 Cured resin layer 41 High refractive index layer 41a First high refractive index layer 41b Second high refractive index layer 42 Low refractive index layer 42a First low refractive index layer 42b Second low refractive index layer

Claims

1. A transparent base film, an intermediate layer, and an anti-reflective layer are arranged in order toward one side in the thickness direction. The refractive index when light with a wavelength of 550 nm is incident on the aforementioned intermediate layer is 1.7 or higher and 1.9 or lower. The anti-reflective layer comprises two or more laminates having a high refractive index layer and a low refractive index layer. An anti-reflective film in which the refractive index when light with a wavelength of 550 nm is incident on the high refractive index layer is greater than 2.50 and less than or equal to 2.

80.

2. The aforementioned high refractive index layer is observed in the electron diffraction pattern using a transmission electron microscope, and Ti ２ O ３ The anti-reflective film according to claim 1, comprising a crystal in which a group of diffraction spots appears.

3. The anti-reflective film according to claim 1, wherein the intermediate layer contains an inorganic oxide.

4. When light with a wavelength of 380 to 780 nm is incident on the aforementioned anti-reflective film, the reflectance Y of the reflected light in the CIE-XYZ color system is 0.4% or less. The anti-reflective film according to any one of claims 1 to 3, wherein the wavelength band in which the spectral reflectance is 1% or less is 280 nm or longer.

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