Anti-reflection film

Abstract

The invention relates to an antireflection film. An antireflection film (1) is provided with a transparent substrate film (2), an intermediate layer (3), and an antireflection layer (4) in this order toward one side in the thickness direction. The refractive index when light having a wavelength of 550 nm is incident on the intermediate layer (3) is 1.7-1.9. The anti-reflection layer (4) includes two or more laminates (10) each having a high refractive index layer (41) and a low refractive index layer (42). The refractive index when light having 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 antireflective films. Background Technology

[0002] To prevent glare from reflected external light, an anti-reflective film is applied to the outermost surface of the display screen in image display devices such as liquid crystal displays (LCDs) and organic EL displays (OLEDs). 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 an antireflective film, it is proposed to achieve high antireflective performance in a wide wavelength band from the ultraviolet region to the infrared region by forming an intermediate refractive index material between a transparent substrate film and an antireflective layer (see, for example, Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2003-248103

[0007] However, the average reflectivity (reflectivity Y) of the aforementioned anti-reflective film in the wavelength range of 350 to 800 nm is only about 0.5%, which cannot adequately prevent glare from reflected external light in image display devices such as liquid crystal displays and organic EL displays.

[0008] On the other hand, in antireflective films, it is desirable to further reduce the reflectivity Y across a wide wavelength band. Summary of the Invention

[0009] This invention provides an antireflective film with a wide wavelength band and low reflectivity.

[0010] The present invention [1] includes an anti-reflective film, which comprises, in sequence on one side facing the thickness direction: a transparent substrate film, an intermediate layer and an anti-reflective layer, such that the refractive index of light with a wavelength of 550 nm incident on the intermediate layer is 1.7 or more and 1.9 or less, and the anti-reflective layer comprises two or more laminates having a high refractive index layer and a low refractive index layer, such that the refractive index of light with a wavelength of 550 nm incident on the high refractive index layer is greater than 2.50 and 2.80 or less.

[0011] The present invention [2] includes the antireflective film described in [1], wherein the high refractive index layer comprises crystals in which diffraction spots of Ti2O3 appear in electron beam diffraction images observed using a transmission electron microscope.

[0012] The present invention [3] includes the antireflective film described in [1], wherein the intermediate layer comprises an inorganic oxide.

[0013] The present invention [4] includes any one of [1] to [3], wherein when light with a wavelength of 380 to 780 nm is incident on the antireflective film, the reflectivity Y of the reflected light in the CIE-XYZ color system is 0.4% or less, and the wavelength band with a spectral reflectivity of 1% or less is 280 nm or more.

[0014] Invention Effects

[0015] The antireflective film of the present invention comprises, on one side facing the thickness direction, a transparent substrate film, an intermediate layer, and an antireflective layer, wherein the refractive index of light with a wavelength of 550 nm incident on the intermediate layer is 1.7 or higher and 1.9 or lower, and the antireflective layer comprises two or more laminates consisting of a high refractive index layer and a low refractive index layer, wherein the refractive index of light with a wavelength of 550 nm incident on the high refractive index layer is greater than 2.50 and 2.80 or lower. Therefore, the reflectivity Y of the antireflective film can be reduced over a wide wavelength band. Attached Figure Description

[0016] Figure 1 A cross-sectional view showing one embodiment of the antireflective film of the present invention.

[0017] Figures 2A-2E express Figure 1 The manufacturing method of the anti-reflective film shown. Figure 2A This indicates the process of preparing a transparent resin film. Figure 2B This refers to the process of forming a cured resin layer on a transparent resin film. Figure 2C This indicates the process of forming an intermediate layer on top of the cured resin layer. Figure 2D This indicates the process of forming an anti-reflective layer on the intermediate layer. Figure 2E This refers to the process of forming an anti-fouling layer on top of the anti-reflective layer.

[0018] Figure 3 express Figure 1 A cross-sectional view of one embodiment of a modified example of the antireflective film shown.

[0019] Explanation of reference numerals in the attached figures

[0020] 1: Anti-reflective film; 2: Transparent substrate film; 3: Intermediate layer; 4: Anti-reflective layer; 5: Anti-fouling layer; 10: Laminate; 10a: First laminate; 10b: Second laminate; 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. Detailed Implementation

[0021] 1. Anti-reflective film

[0022] Reference Figure 1An embodiment of the antireflective film of the present invention will be described.

[0023] like Figure 1 As shown, the antireflective film 1 has a film shape (including a sheet shape) with a specified thickness. Furthermore, the antireflective film 1 extends in a plane direction orthogonal to the thickness direction, and one side of the antireflective film 1 in the thickness direction and the other side in the thickness direction are flat.

[0024] The antireflective film 1 comprises, sequentially on the thickness-direction side: a transparent substrate film 2, an intermediate layer 3, and an antireflective layer 4. The antireflective film 1 may further comprise an antifouling layer 5 on the thickness-direction side of the antireflective layer 4. Specifically, as... Figure 1 As shown, the antireflective film 1 includes: a transparent substrate film 2; an intermediate layer 3 disposed on one side of the transparent substrate film 2 in the thickness direction; an antireflective layer 4 disposed on one side of the intermediate layer 3 in the thickness direction; and an antifouling layer 5 disposed on one side of the antireflective layer 4 in the thickness direction.

[0025] <Transparent substrate film>

[0026] The transparent substrate film 2 is the bottom layer of the antireflective film 1. The transparent substrate film 2 is a transparent, flexible resin film. Furthermore, the transparent substrate film 2 may include, 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. The transparent substrate film 2 is preferably composed 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.

[0027] Examples of materials that can be used 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 cyclic olefin polymers (COP). Examples of cellulose resins include: cellulose triacetate (TAC). The materials used for the transparent resin film 21 can be used alone or in combination of two or more.

[0028] From the perspectives of transparency, heat resistance, and mechanical strength, transparent resin films 21 can be exemplified by, for example, cellulose resin films. Cellulose triacetate films are preferred.

[0029] The total light transmittance (JISK-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, for example, 100% or less.

[0030] The thickness of the transparent resin film 21 is not particularly limited, but from the viewpoint of strength and operability, it is, for example, 5 μm or more, preferably 10 μm or more, more preferably 20 μm or more, further preferably 30 μm or more, especially preferably 50 μm or more. In addition, it is, for example, 300 μm or less, preferably 250 μm or less, more preferably 200 μm or less, further preferably 170 μm or less, especially preferably 150 μm or less.

[0031] It should be noted that the thickness of the transparent resin film 21 can be measured, for example, using a film thickness gauge.

[0032] The cured resin layer 22 improves the mechanical properties of the antireflective film 1. The cured resin layer 22 is in contact with one side of the transparent resin film 21 in the thickness direction.

[0033] Examples of curable resin layers 22 include hard coatings and anti-adhesion layers. Hard coatings, for example, prevent scratches from forming on the exposed surface of the transparent resin film 21. Anti-adhesion layers, for example, impart anti-adhesion properties to the surfaces of multiple anti-reflective films 1 in contact with each other when the anti-reflective films 1 are stacked in the thickness direction.

[0034] 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 coating a curable resin composition onto one side of the transparent resin film 21 in the thickness direction, drying it as needed, and then curing it.

[0035] The curable resin composition contains a curable resin. Examples of curable resins include: polyester resins, urethane acrylate resins, acrylic resins (excluding urethane acrylate resins), urethane resins (excluding urethane acrylate resins), amide resins, silicone resins, epoxy resins, and melamine resins. Uramel acrylate resins are preferably included. The curable resin can be used alone or in combination of two or more.

[0036] Furthermore, examples of curable resin compositions include, for instance, UV-curable resin compositions and thermosetting resin compositions. From the viewpoint of manufacturing efficiency, UV-curable resin compositions are preferred. A specific example of a UV-curable resin composition is the hard coating forming composition disclosed in Japanese Patent Application Publication No. 2016-179686.

[0037] From the viewpoint of adjusting the hardness, surface roughness, refractive index, and imparting anti-glare properties of the cured resin layer 22, the curable resin composition preferably contains microparticles. Examples of microparticles include inorganic and organic particles. Inorganic particles are preferred. Examples of inorganic particles include inorganic oxide particles. Examples of materials that are inorganic oxide particles include: silica, alumina, titanium dioxide, zirconium oxide, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. Silica is preferred. Examples of materials that are organic particles include: polymethyl methacrylate, polystyrene, polyurethane, acrylic / styrene copolymer, benzoguanamine, melamine, and polycarbonate.

[0038] 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 furthermore, for example, 15 μm or less, preferably 12 μm or less, more preferably 10 μm or less.

[0039] If the thickness of the cured resin layer 22 is above or above the aforementioned lower limit, the cured resin layer 22 can be easily formed, and its function can be fully realized. Furthermore, if the thickness of the cured resin layer is below or below the aforementioned upper limit, the antireflective film 1 can be thinned.

[0040] From the viewpoint of improving the adhesion with the intermediate layer 3 described later, one side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction may also be surface-modified. Surface modification treatment is preferred. Examples of surface modification treatments include: corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, saponification treatment, and treatment using coupling agents. Plasma treatment is preferred. That is, the side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction is preferably a plasma-treated surface.

[0041] The total light transmittance (JISK-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, for example, 100% or less.

[0042] The thickness of the transparent substrate film 2 is not particularly limited, but from the viewpoint of strength and operability, it is, for example, 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and, for example, 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less.

[0043] <Intermediate Layer>

[0044] Intermediate layer 3 adjusts the refractive index difference between transparent substrate film 2 and antireflective layer 4. Intermediate layer 3 is a dry coating layer or a wet coating layer, preferably a dry coating layer, and more preferably a sputtered layer. Intermediate layer 3 is disposed on one side of the thickness direction of transparent substrate film 2 and on the other side of the thickness direction of antireflective layer 4. Specifically, as follows... Figure 1 As shown, the intermediate layer 3 is disposed on one side of the transparent substrate film 2 in the thickness direction (the side of the cured resin layer 22 in the thickness direction). That is, the intermediate layer 3 is in contact with the transparent substrate film 2 (cured resin layer 22).

[0045] As the material for intermediate layer 3, inorganic materials can be used in the case of dry coating, while a mixture of organic materials and inorganic particles can be used in the case of wet coating.

[0046] Examples of inorganic materials include: metals, alloys containing two or more metals, metalloids, and oxides of these metals.

[0047] Examples of metals that can be listed include: nickel, chromium, indium, aluminum, tin, gold, silver, platinum, zinc, titanium, tungsten, zirconium, and palladium.

[0048] As a quasi-metal, silicon is an example that can be cited.

[0049] Examples of metal oxides include zinc-containing oxides, indium-containing oxides, and antimony-containing oxides. Examples of zinc-containing oxides include aluminum-zinc-silicon composite oxides (Al-Zn-SiO₂). x Examples of indium-containing oxides include indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), and indium gallium zinc oxide (IGZO). Examples of antimony-containing oxides include antimony tin oxide (ATO).

[0050] As a mixture of organic materials and inorganic particles, examples include adhesive resins and inorganic particles dispersed in adhesive resins.

[0051] Examples of UV-curable resins that can be used as adhesives include cured products of UV-curable resins. Examples of UV-curable resins include epoxy resins, urethane acrylate resins, acrylic resins (excluding urethane acrylate resins), and urethane resins (excluding urethane acrylate resins).

[0052] Inorganic particles, for example, can be metal oxide particles. Examples of metal oxides include zirconium oxide, aluminum oxide, titanium oxide, and silicon oxide. The type and amount of metal oxide particles are adjusted so that the refractive index of the resulting intermediate layer 3 when light with a wavelength of 550 nm is incident on it is within the range described later.

[0053] The proportion of inorganic microparticles relative to the total amount of the binder resin and the inorganic microparticles dispersed in the binder resin is, for example, 10% by mass or more, preferably 20% by mass or more. Furthermore, it is, for example, 90% by mass or less, preferably 80% by mass or less. If the amount of inorganic microparticles is too high, the mechanical properties of the resulting antireflective film 1 may be insufficient. Furthermore, if the amount of inorganic microparticles is too low, the desired reflectivity Y may not be obtained.

[0054] As the material for the intermediate layer 3, inorganic oxides are preferred. More preferably, oxides comprising at least one element selected from the group consisting of silicon, zinc, aluminum, tin, titanium, indium, and zirconium are preferred. From the viewpoint that the antireflective layer 4 can be formed without damaging the surface of the cured resin layer 22 by sputtering using a HiPIMS power supply as described later, aluminum-zinc-silicon composite oxide (Al-Zn-SiO2) is even more preferred. x That is to say, the intermediate layer 3 contains inorganic oxides, preferably Al-Zn-SiO. x layer.

[0055] In Al-Zn-SiO x In this process, the proportion of alumina relative to the total amount of alumina, 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. Furthermore, it is, for example, 10% by mass or less, preferably 7% by mass or less, and more preferably 5% by mass or less. If the proportion of alumina 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 the range described later.

[0056] In Al-Zn-SiO x In this process, the proportion of zinc oxide relative 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. Furthermore, it is, for example, 30% by mass or less, preferably 25% by mass or less, and more preferably 22% by mass or less. If the proportion 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 the range described later.

[0057] 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 antireflective layer 4, which is 1.7 or higher, preferably 1.75 or higher. Furthermore, 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 the above range, the reflectivity Y of the antireflective film 1 can be reduced over a wide wavelength band.

[0058] The surface hardness (surface hardness H) of the intermediate layer 3, measured by nanoindentation at 25°C, is, for example, 1.05 GPa or more, preferably 1.1 GPa or more, more preferably 1.15 GPa or more, even more preferably 1.2 GPa or more, and particularly preferably 1.25 GPa or more. Furthermore, it is, for example, 30 GPa or less, preferably 20 GPa or less, and more preferably 15 GPa or less. If the surface hardness H is within the above range, the antireflective layer 4 can be formed without damaging the surface of the cured resin layer 22 by sputtering using a HiPIMS power supply, as described later.

[0059] The nanoindentation method was performed according to ISO 14577. Furthermore, the nanoindentation method employed was the same as that described in Examples 1-4 of Japanese Patent Application Publication No. 2023-013412.

[0060] 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, and even more preferably 85 nm or more. In addition, it is, for example, 110 nm or less, preferably 100 nm or less, more preferably 95 nm or less, and even more preferably 90 nm or less.

[0061] If the thickness of the intermediate layer 3 is within the above range, the anti-reflective layer 4 can be formed without damaging the surface of the cured resin layer 22 by sputtering using a HiPIMS power supply as described later.

[0062] <Anti-reflective layer>

[0063] The anti-reflective layer 4 suppresses the intensity of external light reflection. The anti-reflective layer 4 is a dry-coated layer, preferably a sputtered layer. The anti-reflective layer 4 is disposed on one side of the intermediate layer 3 in the thickness direction. That is, the anti-reflective layer 4 is in contact with the intermediate layer 3.

[0064] The antireflective layer 4 comprises a stack of layers, wherein the stack includes 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 antireflective layer 4, the intensity of external light reflection is suppressed through interference between reflected light at multiple interfaces of the multiple thin layers (high refractive index layer 41 and low refractive index layer 42). Furthermore, in the antireflective layer 4, the interference effect of suppressing reflection intensity can be achieved by adjusting the optical film thickness (the product of refractive index and thickness) of each thin layer. Moreover, the uppermost layer of the antireflective layer 4 (the layer furthest to one side in the thickness direction) is preferably the low refractive index layer 42.

[0065] The anti-reflective layer 4 comprises two or more laminates 10 having a high refractive index layer 41 and a low refractive index layer 42.

[0066] The antireflective layer 4 preferably comprises two laminates 10. Specifically, as follows: Figure 1As shown, the anti-reflective layer 4 comprises: a first stack 10a having a first high refractive index layer 41a (first layer) and a first low refractive index layer 42a (second layer); and a second stack 10b having a second high refractive index layer 41b (third layer) and a second low refractive index layer 42b (fourth layer).

[0067] More specifically, such as Figure 1 As shown, the first laminate 10a is disposed on one side of the intermediate layer 3 in the thickness direction, and the second laminate 10b is disposed on one side of the first laminate 10a in the thickness direction.

[0068] In detail, such as Figure 1 As shown, 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 (the layer furthest to one side in the thickness direction) of the antireflective layer 4 is preferably the second low refractive index layer 42b (fourth layer).

[0069] By including two or more laminates 10 with high refractive index layers 41 and low refractive index layers 42, the reflectivity Y of the antireflective film 1 can be reduced in a wide wavelength band.

[0070] The high refractive index layer 41 is a crystalline layer. The high refractive index layer 41 may also include amorphous regions. Preferably, the high refractive index layer 41 is a layer that includes only crystalline regions and excludes amorphous regions. It should be noted that amorphous regions can be identified, for example, by observing the planar orientation of the high refractive index layer 41 using a transmission electron microscope.

[0071] The high-refractive-index layer 41 comprises an oxide of titanium (Ti). Specifically, the high-refractive-index layer 41 comprises crystals exhibiting diffraction spot groups of Ti₂O₃ in electron beam diffraction images observed using a transmission electron microscope. In addition to crystals exhibiting diffraction spot groups of Ti₂O₃, the high-refractive-index layer 41 may also comprise crystals exhibiting diffraction spot groups other than Ti₂O₃. Specifically, the high-refractive-index layer 41 may also comprise crystals exhibiting diffraction spot groups of rutile-type TiO₂, anatase-type TiO₂, brookite-type TiO₂, and TiO. Preferably, in the high-refractive-index layer 41, only diffraction spot groups of Ti₂O₃ appear in electron beam diffraction images observed using a transmission electron microscope, and no diffraction spot groups other than Ti₂O₃ appear. The crystal structure contained in the high-refractive-index layer 41 will be identified in detail by the analysis of the electron beam diffraction images described later.

[0072] The high refractive index layer 41 contains a crystal in which Ti2O3 diffraction spots appear in electron beam diffraction images observed using a transmission electron microscope, such that the refractive index of light with a wavelength of 550 nm incident on the high refractive index layer 41 is within the range described later.

[0073] Materials used for the low refractive index layer 42 include, for example, silicon oxide and magnesium fluoride. Silicon oxide is preferred. That is, the low refractive index layer 42 is preferably a silicon oxide layer. The uppermost layer (the layer furthest to one side in the thickness direction) of the antireflective layer 4 is preferably a silicon oxide layer. It should be noted that the silicon oxide layer is a layer formed of silicon oxide.

[0074] 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, the refractive index of the high-refractive-index layer 41 when light with a wavelength of 550 nm is incident on it is greater than 2.50, preferably greater than 2.54, and is less than 2.80, preferably less than 2.60. Furthermore, the refractive index of the low-refractive-index layer 42 when light with a wavelength of 550 nm is incident on it is less than 1.5. It should be noted that the refractive index of the layer containing diffraction spots of Ti₂O₃ in an electron beam diffraction image observed using a transmission electron microscope is 2.55 when light with a wavelength of 550 nm is incident on it. Furthermore, when the high-refractive-index layer 41 is a layer formed of niobium oxide (niobium oxide layer), the refractive index of the niobium oxide layer when light with a wavelength of 550 nm is incident on it is 2.44. Furthermore, the refractive index of the silicon oxide layer when light with a wavelength of 550 nm is incident on it is 1.46. The refractive index of light with a wavelength of 550 nm incident on each layer is determined by the refractive index measurement described later.

[0075] If the refractive index of light with a wavelength of 550nm is within the above range when incident on the high refractive index layer 41, the reflectivity Y of the antireflective film 1 can be reduced in a wide wavelength band.

[0076] The difference between the refractive index of light with a wavelength of 550 nm incident on the high refractive index layer 41 and the refractive index of light with a wavelength of 550 nm incident on the low refractive index layer 42 (refractive index difference) 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 reflectivity Y of the antireflective film 1 can be reduced over a wide wavelength band.

[0077] 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, and even more preferably 25 nm or more. In addition, it is, for example, 100 nm or less, preferably 50 nm or less, more preferably 40 nm or less, and even more preferably 30 nm or less.

[0078] 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, and even more preferably 25 nm or more. In addition, it is, 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.

[0079] 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, and even more preferably 50 nm or more. In addition, it is, 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.

[0080] 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, and even more preferably 25 nm or more. In addition, it is, for example, 100 nm or less, preferably 50 nm or less, more preferably 40 nm or less, and even more preferably 30 nm or less.

[0081] 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 furthermore, 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.

[0082] 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, and even more preferably 125 nm or more. In addition, it is, for example, 150 nm or less, preferably 140 nm or less, more preferably 135 nm or less, and even more preferably 130 nm or less.

[0083] 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. In addition, they are, for example, 100 nm or less.

[0084] The optical film thickness of the first low-refractive-index layer 42a (second layer) is, for example, 30 nm or more, and also, 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 also, for example, 160 nm or less.

[0085] The total thickness of the antireflective layer 4 is, for example, 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, and even more preferably 180 nm or more. In addition, it is, for example, 300 nm or less, preferably 250 nm or less, more preferably 220 nm or less, and even more preferably 200 nm or less.

[0086] If the total thickness of the anti-reflective layer 4 is above the lower limit mentioned above, the intensity of external light reflection can be suppressed. If the total thickness of the anti-reflective layer 4 is below the upper limit mentioned above, the cracking of the anti-reflective layer 4 can be suppressed.

[0087] The ratio of the thickness (total thickness) of the high refractive index layer 41 to the total thickness of the antireflective layer 4 is, for example, 10% or more, preferably 15% or more, more preferably 20% or more, and even more preferably 25% or more. In addition, it is, for example, 60% or less, preferably 50% or less, and more preferably 35% or less.

[0088] The ratio of the thickness (total thickness) of the low refractive index layer 42 to the total thickness of the antireflective layer 4 is, for example, 40% or more, preferably 50% or more, more preferably 60% or more, and even more preferably 65% ​​or more. In addition, it is, for example, 85% or less, preferably 80% or less, and more preferably 75% or less.

[0089] That is, 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.

[0090] The thickness-direction side of the antireflective layer 4 (the side for which the antifouling layer 5 is disposed) may also undergo surface modification treatment. Surface treatment is preferred. Examples of surface modification treatments include: corona treatment, plasma treatment, ozone treatment, primer treatment, and coupling agent treatment. Plasma treatment is preferred. Examples of plasma treatments include: plasma treatment based on glow discharge, plasma treatment based on low-inductance antennas, and plasma treatment based on atmospheric pressure plasma. Plasma treatment based on low-inductance antennas and plasma treatment based on atmospheric pressure plasma are preferred, and plasma treatment based on atmospheric pressure plasma is more preferred. That is, the thickness-direction side of the antireflective layer 4 is preferably a plasma-treated surface, and more preferably a plasma-treated surface based on atmospheric pressure plasma.

[0091] The surface roughness Ra (arithmetic mean surface roughness) of the side of the antireflective layer 4 in the thickness direction (the side on which the antifouling layer 5 is disposed) is, for example, 0.5 nm or more, preferably 0.8 nm or more, and furthermore, for example, 10 nm or less, preferably 8 nm or less.

[0092] It should be noted that the surface roughness Ra can be calculated, for example, from a 1 μm square observation image obtained using AFM (atomic force microscopy).

[0093] <Anti-fouling layer>

[0094] The anti-fouling layer 5 has an anti-fouling function. The anti-fouling function of the anti-fouling layer 5 includes: inhibiting the adhesion of contaminants such as oils from the hands to the exposed surface of the film when using the anti-reflective film 1, and making it easy to remove the attached contaminants.

[0095] The antifouling layer 5 is a dry coating layer, preferably a vacuum evaporation layer. The antifouling layer 5 is disposed on one side of the antireflective layer 4 in the thickness direction. That is, the antifouling layer 5 is in contact with the antireflective layer 4.

[0096] As a material for the antifouling layer 5, examples include fluorinated organic compounds. As a fluorinated organic compound, alkoxysilane compounds having a perfluoropolyether group are preferred. As an alkoxysilane compound having a perfluoropolyether group, examples include compounds represented by the following general formula (1).

[0097] R 1 -R 2 -X- (CH2) m -Si(OR) 3 3 (1)

[0098] In general formula (1), R 1 A fluoroalkyl group (with a carbon number of, for example, 1 or more and 20 or less) is defined as a straight-chain or branched alkyl group in which one or more hydrogen atoms of the alkyl group are replaced by fluorine atoms. Preferably, a perfluoroalkyl group is defined as a alkyl group in which all hydrogen atoms of the alkyl group are replaced by fluorine atoms.

[0099] R 2 The structure represents a repeating structure containing at least one perfluoropolyether (PFPE) group, preferably a structure containing two repeating PFPE groups. Examples of repeating PFPE groups include repeating structures with linear PFPE groups and repeating structures with branched PFPE groups. Examples of repeating structures with linear PFPE groups include –(OC…) n F 2n ) p - The structure shown (n represents an integer greater than 1 and less than 20, p represents an integer greater than 1 and less than 50. The same applies below). A repeating structure as a branched PFPE base, for example, can be enumerated as -(OC(CF3)2). p - The structure shown and - (OCF2CF(CF3)CF2) p The structure shown is shown in the figure. As a repeating structure of the PFPE group, a repeating structure of a linear PFPE group is preferred, and a repeating structure of (OCF2) is more preferred. p - and - (OC2F4) p -.

[0100] R 3 The alkyl group has 1 or more but less than 4 carbon atoms, and preferably methyl.

[0101] X represents an ether group, carbonyl group, amino group, or amide group, preferably an ether group.

[0102] m represents an integer greater than or equal to 1. Furthermore, m preferably represents an integer less than or equal to 20, more preferably an integer less than or equal to 10, and even more preferably an integer less than or equal to 5.

[0103] As an alkoxysilane compound having a perfluoropolyether group, the compound shown in the following general formula (2) is preferred.

[0104] CF3-(OCF2) q - (OC2F4) r -O-(CH2)3-Si(OCH3)3 (2)

[0105] In general formula (2), q represents an integer greater than 1 and less than 50, and r represents an integer greater than 1 and less than 50.

[0106] Furthermore, alkoxysilane compounds with perfluoropolyether groups can be used alone or in combination with two or more.

[0107] As long as the material of the antifouling layer 5 contains an alkoxysilane compound with a perfluoropolyether group, and the antifouling layer 5 is a dry coating layer (preferably a vacuum evaporation layer), a high adhesion between the antifouling layer 5 and the antireflective 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.

[0108] 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 of the surface is above the lower limit mentioned above, 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 relative to the surface.

[0109] The thickness of the antifouling 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. Furthermore, it is, for example, 20 nm or less, preferably 15 nm or less, and more preferably 10 nm or less.

[0110] The difference in refractive index between the antifouling layer 5 and the layer in contact with it is preferably small. Specifically, when the antifouling layer 5 is in contact with the low refractive index layer 42 (silicon oxide layer), 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.

[0111] The surface roughness Ra (arithmetic mean surface roughness) of the side (exposed surface) of the antifouling layer 5 in the thickness direction is, for example, 1 nm or more, preferably 2 nm or more, and furthermore, for example, 10 nm or less, preferably 8 nm or less, and more preferably 6 nm or less.

[0112] It should be noted that the surface roughness Ra can be calculated, for example, from a 1 μm square observation image obtained using AFM (atomic force microscopy).

[0113] <Effects>

[0114] When light with a wavelength of 380 to 780 nm is incident on the antireflective film 1, the wavelength band with a spectral reflectance of less than 1% of the antireflective film 1 is 280 nm or more, preferably 320 nm or more, and more preferably 350 nm or more.

[0115] The spectral reflectance of the antireflective film 1 is determined by the spectral reflectance evaluation described later.

[0116] When light with a wavelength of 380 to 780 nm is incident on the antireflective 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.

[0117] The reflectivity Y of the antireflective film 1 is obtained by the calculation of reflectivity Y described later.

[0118] When light with a wavelength of 380 to 780 nm is incident on the antireflective 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.

[0119] The value of a* of the antireflective film 1 is obtained by calculation formulas (3) to (5) in the reflection hue section described later.

[0120] The thickness of the antireflective film 1 is, for example, 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, and even more preferably 50 μm or more. In addition, it is, for example, 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less.

[0121] 2. Manufacturing method of antireflective film

[0122] Reference Figures 2A-2E An embodiment of the method for manufacturing the antireflective film of the present invention will be described.

[0123] The manufacturing method of the antireflective film 1 includes, for example, a preparation step, preparing a transparent resin film 21 ( Figure 2A); Curing resin layer formation process, forming a cured resin layer 22 on the transparent resin film 21 ( Figure 2B ); intermediate layer forming process, intermediate layer 3 is formed on cured resin layer 22 ( Figure 2C ); Anti-reflective layer forming process, forming anti-reflective layer 4 on intermediate layer 3 ( Figure 2D ); and the antifouling layer forming process, forming an antifouling layer 5 on the antireflective layer 4 ( ); Figure 2E ).

[0124] <Preparation Process>

[0125] In the preparation process, such as Figure 2A As shown, prepare a transparent resin film 21.

[0126] <Curing Resin Layer Formation Process>

[0127] In the process of forming the cured resin layer, such as Figure 2B As shown, 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 coated on one side of the transparent resin film 21 in the thickness direction, and after forming a coating film, the coating film is cured to form the cured resin layer 22.

[0128] The curable resin composition may further include a photopolymerization initiator, a leveling agent, and a solvent (diluent).

[0129] When the curable resin composition contains a solvent, the coating on the transparent resin film 21 is dried after the curable resin composition is applied.

[0130] The drying temperature is, for example, 50°C to 120°C. The drying time is, for example, 10 seconds to 10 minutes.

[0131] When the curable resin composition contains a UV-curable resin, the coating on the transparent resin film 21 is cured by UV irradiation. Examples of UV irradiation sources include high-pressure mercury lamps and LED lamps. High-pressure mercury lamps are preferred. The cumulative UV irradiation intensity is, for example, 100 mJ / cm². 2 ~500mJ / cm 2 .

[0132] As described above, a transparent substrate film 2 having a cured resin layer 22 on one side of the transparent resin film 21 in the thickness direction is obtained.

[0133] <Intermediate Layer Formation Process>

[0134] In the intermediate layer formation process, such as Figure 2C As shown, the material of the intermediate layer 3 is formed on one side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction to form the intermediate layer 3.

[0135] Methods for forming the intermediate layer 3 include dry coating and wet coating. Examples of dry coating methods include vacuum evaporation, sputtering, and ion plating. Sputtering is preferred. Examples of wet coating methods include gravure coating, reverse coating, and die coating.

[0136] Examples of sputtering methods include diode sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering. Reactive sputtering using magnetron sputtering is a preferred example.

[0137] In sputtering, a sputtering film-forming apparatus capable of performing film-forming processes in a roll-to-roll manner can be used. In the intermediate layer formation process, when using a roll-to-roll sputtering film-forming apparatus, the transparent substrate film 2, serving as the working film W, is moved from the feed roller of the sputtering film-forming apparatus to the take-up roller, and the material of the intermediate layer 3 is formed on the thickness-direction side of the transparent substrate film 2, thus forming the intermediate layer 3. The travel speed of the working film W (transparent substrate film 2) is, for example, 0.1 to 10.0 m / min.

[0138] In the sputtering process, specifically, a sputtering gas (an inert gas) is introduced into the film-forming chamber under vacuum conditions, and a negative voltage is applied to the target formed from the aforementioned intermediate layer 3 material within the film-forming chamber. This generates a glow discharge, ionizing the gas atoms. 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 of the working film W (transparent substrate film 2) in the thickness direction. The target material is a sintered body of the aforementioned intermediate layer 3 material. Examples of sintered bodies of the intermediate layer 3 material include sintered bodies of alumina, zinc oxide, and silicon oxide.

[0139] Examples of sputtering gases include argon, krypton, xenon, and mixtures thereof, with argon being the preferred example. In reactive sputtering, for example, oxygen, as a reactive gas, is also introduced into the film-forming chamber in addition to the sputtering gas. That is, the intermediate layer 3 is formed in the presence of an inert gas and oxygen.

[0140] The ultimate vacuum degree in the film-forming chamber is, for example, 1.0 × 10⁻⁶. －4 Below Pa.

[0141] In reactive sputtering, the volume of oxygen introduced into the film-forming chamber is, for example, 0.01 vol% to 30 vol% relative to the total volume of sputtering gas and oxygen (reactive gas), preferably 0.1 vol% to 20 vol%, more preferably 1 vol% to 10 vol%, and even more preferably 2 vol% to 5 vol%.

[0142] The film-forming temperature (the temperature of the transparent substrate film 2 when forming the intermediate layer 3) 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.

[0143] The pressure in the film-forming chamber (the pressure in the film-forming 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.

[0144] Examples of power sources for applying voltage to a target include DC power supplies, AC power supplies, MF power supplies, and RF power supplies. An MFAC power supply, which combines MF and AC power supplies, can also be used. An MFAC power supply is preferred as a power source.

[0145] The discharge power is, for example, 1kW to 20kW, preferably 3kW to 10kW.

[0146] The horizontal magnetic field strength on the target is, for example, 10mT to 100mT.

[0147] In the wet coating method, a coating liquid (varnish) containing the material of the intermediate layer 3 is applied to one side of the transparent substrate film 2 in the thickness direction. After the coating film is formed, the coating film is dried and cured, thereby forming the intermediate layer 3. As the material of the intermediate layer 3, a mixture of organic materials and inorganic particles can be listed. More specifically, an adhesive resin and inorganic particles dispersed in the adhesive resin can be listed.

[0148] The drying temperature is, for example, 60°C to 120°C. The drying time is, for example, 10 minutes to 60 minutes.

[0149] The coating on the dried transparent substrate film 2 is cured by ultraviolet (UV) irradiation. Examples of UV light sources include high-pressure mercury lamps and LED lamps. High-pressure mercury lamps are preferred. The cumulative UV irradiation intensity is, for example, 100 mJ / cm². 2 ~500mJ / cm 2 .

[0150] As described above, an intermediate layer 3 is formed on one side of the transparent substrate film 2 in the thickness direction.

[0151] By forming an intermediate layer 3 on one side of the thickness direction of the transparent substrate film 2 (cured resin layer 22), the anti-reflective layer 4 can be formed without damaging the surface of the cured resin layer 22 by sputtering using a HiPIMS power supply, as described later.

[0152] It should be noted that plasma treatment can be performed on one side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction before the intermediate layer formation process. A roll-to-roll sputtering apparatus can be used for plasma treatment. That is, plasma treatment and the formation of the intermediate layer 3 can be performed continuously.

[0153] Examples of plasma processing include: plasma processing based on glow discharge, plasma processing based on low-inductance antennas, and plasma processing based on atmospheric pressure plasma.

[0154] Plasma processing based on glow discharge is a preferred example. Depending on the plasma processing method, the following conditions can be adjusted appropriately.

[0155] Specifically, sputtering gas (inert gas) and / or reactive gas are introduced into the plasma treatment chamber of the sputtering film forming apparatus under vacuum conditions, and a voltage is applied to generate plasma, thereby performing plasma treatment on one side of the transparent substrate film 2 (cured resin layer 22) in the thickness direction.

[0156] Examples of sputtering gases used in plasma processing include nitrogen, argon, krypton, xenon, and mixtures thereof. Additionally, examples of reactive gases used in plasma processing include oxygen.

[0157] The ultimate vacuum level inside the plasma processing chamber is, for example, 1.0 × 10⁻⁶. －4 Below Pa.

[0158] The pressure inside the plasma processing chamber (the 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.

[0159] The discharge power in the plasma processing chamber is, for example, 0.01kW to 10kW, preferably 0.05kW to 5kW.

[0160] <Anti-reflective layer formation process>

[0161] In the process of forming the anti-reflective layer, such as Figure 2D As shown, an anti-reflective layer 4 is formed on one side of the thickness direction of the intermediate layer 3.

[0162] As a method for forming the antireflective layer 4, dry coating is an example. Examples of dry coating methods include vacuum evaporation, sputtering, and ion plating. Sputtering is a preferred method.

[0163] Examples of sputtering methods include diode sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering. Reactive sputtering using magnetron sputtering is a preferred example.

[0164] In sputtering, a sputtering film-forming apparatus capable of performing film-forming processes in a roll-to-roll manner can be used. In the antireflective layer formation process, when using a roll-to-roll sputtering film-forming apparatus, a transparent substrate film 2 having an intermediate layer 3, serving as the working film W, is moved from the feed roller of the sputtering film-forming apparatus to the take-up roller, and the materials of the laminate (specifically, titanium oxide and silicon oxide) are sequentially deposited on one side in the thickness direction of the intermediate layer 3 to form a laminate. The travel speed of the working film W (the transparent substrate film 2 having the intermediate layer 3) is, for example, 0.1 to 10.0 m / min.

[0165] It should be noted that in the sputtering method of the antireflective layer formation process, it is preferable to use a sputtering film forming apparatus having multiple film forming chambers arranged sequentially along the travel path of the working film W (a transparent substrate film 2 having an intermediate layer 3) to form the first to fourth layers sequentially.

[0166] In the sputtering method, specifically, a sputtering gas (inert gas) is introduced into the film-forming chamber of the sputtering film-forming apparatus under vacuum conditions, and a negative voltage is applied to the target formed by the material of the aforementioned anti-reflective layer 4 within the film-forming chamber. This generates a glow discharge, ionizing the gas atoms, causing the gas ions to collide with the target surface at high speed, ejecting the target material from the target surface, and causing the ejected target material to be deposited sequentially in the thickness direction.

[0167] Examples of sputtering gases include argon, krypton, xenon, and mixtures thereof, with argon being a preferred example. In reactive sputtering, oxygen, as a reactive gas, is also introduced into the film-forming chamber, in addition to the sputtering gas.

[0168] In the first layer of film formation, titanium is used as the target material.

[0169] In the first layer film formation, the ultimate vacuum degree in the film formation chamber before sputtering film formation and the gas pressure in the film formation chamber (the gas pressure in the film formation chamber when sputtering gas and / or oxygen are introduced) are the same as those in the intermediate layer formation process described above.

[0170] In the formation of the first layer, the volume of oxygen introduced into the film-forming chamber is, for example, 0.1% to 30% of the total volume of sputtering gas and oxygen (reactive gas), preferably 1% to 20% of the total volume, and more preferably 5% to 10% of the total volume.

[0171] In the film formation of the first layer, the film formation temperature (the temperature of the roller 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.

[0172] In the deposition of the first layer, the power source for applying voltage to the target can be, for example, a DC power source, an AC power source, an MF power source, an RF power source, and a high-power pulsed magnetron sputtering (HiPIMS) power source. An MF power source and an AC power source, or an MFAC power source, can be used as the power source. A HiPIMS power source is preferred.

[0173] In sputtering using a HiPIMS power supply, specifically, a high-density plasma is generated by applying a voltage to the target at a specified 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.

[0174] By using a sputtering method with a HiPIMS power supply, a layer containing a group of diffraction spots of Ti2O3 appearing in an electron beam diffraction image observed using a transmission electron microscope can be obtained. Furthermore, the antireflective layer 4 can be formed without damaging the surface of the cured resin layer 22.

[0175] In the formation of the first layer, the discharge voltage used when using a HiPIMS power supply is, for example, 1000V to 2000V, preferably 1500V to 1800V. If the discharge voltage is within the above range, a layer containing crystals with diffraction spot groups of Ti2O3 appearing in the electron beam diffraction image observed using a transmission electron microscope can be obtained.

[0176] In the formation of the first layer, the frequency used when using the HiPIMS power supply is, for example, 150Hz to 300Hz, preferably 200Hz to 250Hz. If the frequency is within the above range, a layer containing crystals that exhibit Ti2O3 diffraction spot groups in the electron beam diffraction image observed using a transmission electron microscope can be obtained.

[0177] In the formation of the first layer, the pulse width when using the HiPIMS power supply 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 a crystal containing diffraction spot groups of Ti2O3 appearing in the electron beam diffraction image observed using a transmission electron microscope can be obtained.

[0178] In the formation of the first layer, the horizontal magnetic field strength on the target is the same as that in the intermediate layer formation process described above.

[0179] In the second layer of film formation, silicon is used as the target material.

[0180] In the second layer film formation, the ultimate vacuum degree in the film formation chamber before sputtering film formation and the gas pressure in the film formation chamber (the gas pressure in the film formation chamber when sputtering gas and / or oxygen are introduced) are the same as those in the intermediate layer formation process described above.

[0181] In the second layer of film formation, the volume of oxygen introduced into the film formation chamber is, for example, 5% to 50% of the total volume of sputtering gas and oxygen (reactive gas), preferably 10% to 40% of the total volume, and more preferably 20% to 35% of the total volume.

[0182] In the second layer of film formation, the film formation temperature (the temperature of the roller 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.

[0183] In the deposition of the second layer, the power source for applying voltage to the target can be, for example, a DC power source, an AC power source, an MF power source, an RF power source, and a high-power pulsed magnetron sputtering (HiPIMS) power source. An MF power source and an AC power source, or an MFAC power source, can be used as the power source. An MFAC power source is preferred.

[0184] In the second layer of film formation, the discharge power when using an MFAC power supply is, for example, 10kW to 100kW, preferably 20kW to 50kW.

[0185] In the formation of the second layer, the horizontal magnetic field strength on the target is the same as that in the intermediate layer formation process described above.

[0186] The third layer is formed under the same conditions as the first layer described above.

[0187] The fourth layer is formed under the same conditions as the second layer described above.

[0188] As described above, an anti-reflective layer 4 is formed on one side of the intermediate layer 3 in the thickness direction.

[0189] It should be noted that plasma treatment can also be performed on one side of the antireflective layer 4 in the thickness direction after the antireflective layer formation process. Plasma treatment can be performed using a roll-to-roll sputtering apparatus or a direct-type atmospheric pressure plasma surface treatment apparatus. When using a roll-to-roll sputtering apparatus for plasma treatment, the formation of the antireflective layer 4 and the plasma treatment can be carried out continuously.

[0190] Examples of plasma processing methods include: plasma processing based on glow discharge, plasma processing based on low-inductance antennas, and plasma processing based on atmospheric pressure plasma. The following conditions can be adjusted appropriately depending on the plasma processing method.

[0191] Specifically, in the cases of plasma processing based on glow discharge and plasma processing based on low-inductance antenna, sputtering gas (inert gas) and / or reactive gas are introduced into the plasma processing chamber of the sputtering film deposition apparatus under vacuum conditions, and a voltage is applied to generate plasma, thereby performing plasma processing on one side of the antireflective layer 4 in the thickness direction. It should be noted that the travel speed of the working film W (the transparent substrate film 2 having the antireflective layer 4 and the intermediate layer 3) is, for example, 0.1 to 10.0 m / min.

[0192] Furthermore, in the case of plasma treatment based on atmospheric pressure plasma, plasma treatment can be performed, for example, using a direct atmospheric pressure plasma surface treatment apparatus. The direct atmospheric pressure plasma surface treatment apparatus includes: a plasma treatment chamber; a flat discharge electrode connected to an AC power source within the plasma treatment chamber; and a flat grounding electrode, disposed opposite the discharge electrode at a distance from it within the plasma treatment chamber, and grounded. In the direct atmospheric pressure plasma surface treatment apparatus, an inert gas and / or a reactive gas is introduced into the plasma treatment chamber at atmospheric pressure, and a voltage is applied to generate plasma, thereby performing plasma treatment on one side of the antireflective layer 4 in the thickness direction. It should be noted that the travel speed of the working film W (the transparent substrate film 2 having the antireflective layer 4 and the intermediate layer 3) (the moving speed of the grounding electrode) is, for example, 0.1 to 10.0 m / min.

[0193] Examples of sputtering gases used in plasma processing include nitrogen, argon, krypton, xenon, and mixtures thereof. Additionally, examples of reactive gases used in plasma processing include oxygen.

[0194] The ultimate vacuum level inside the plasma processing chamber is, for example, 1.0 × 10⁻⁶. －4 Below Pa. It should be noted that plasma treatment based on atmospheric pressure plasma is carried out at atmospheric pressure.

[0195] The pressure inside the plasma processing chamber (the 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. It should be noted that plasma processing based on atmospheric pressure plasma is performed at atmospheric pressure.

[0196] The discharge power in the plasma treatment chamber is adjusted appropriately according to the plasma treatment method, for example, from 0.1kW to 30kW, preferably from 0.2kW to 10kW.

[0197] <Antifouling layer formation process>

[0198] In the process of forming the antifouling layer, such as Figure 2E As shown, an anti-fouling layer 5 is formed on one side of the anti-reflective layer 4 in the thickness direction.

[0199] Methods for forming the antifouling layer 5 include, for example, dry coating and wet coating. From the viewpoint of production efficiency, dry coating is preferred. Examples of dry coating methods include vacuum evaporation, sputtering, and CVD, with vacuum evaporation being the most preferred. Examples of wet coating methods include coating.

[0200] In the vacuum evaporation method, the material of the above-mentioned antifouling layer 5 is dried, and the solidified material is used as the evaporation source.

[0201] The vapor deposition temperature is, for example, 150°C to 500°C, preferably 200°C to 300°C.

[0202] The ultimate vacuum level in the film-forming chamber during vapor deposition is, for example, 1.0 × 10⁻⁶. －4 Below Pa.

[0203] As described above, an anti-fouling layer 5 is formed on one side of the anti-reflective layer 4 in the thickness direction.

[0204] As described above, an antireflective film 1 is manufactured.

[0205] 3. Variations

[0206] <Examples of variations of antireflective film>

[0207] exist Figure 1 In the transparent substrate film 2, the structure is composed of, but is not limited to, 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.

[0208] That is to say, the transparent substrate film 2 may also be composed solely of the transparent resin film 21. Furthermore, the cured resin layer 22 may be disposed on both sides of the transparent resin film 21 in the thickness direction.

[0209] In addition, Figure 1 In the process, the anti-reflective layer 4 is a stack composed 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.

[0210] In other words, there are no particular limitations on the anti-reflective layer 4 as long as it comprises two or more laminates 10 having a high refractive index layer 41 and a low refractive index layer 42. Specifically, there are no particular limitations on the number of layers or the stacking order of the anti-reflective layer 4.

[0211] That is, the anti-reflective layer 4 may also include, for example, three or more laminates 10 having a high refractive index layer 41 and a low refractive index layer 42.

[0212] Furthermore, regarding the anti-reflective layer 4, for example, a low-refractive-index layer 42 can be disposed on one side of the intermediate layer 3 in the thickness direction, and a high-refractive-index layer 41 can be disposed on one side of the low-refractive-index layer 42 in the thickness direction. Specifically, the first low-refractive-index layer 42a can be connected to the intermediate layer 3, the first high-refractive-index layer 41a can be connected to the first low-refractive-index layer 42a, the second low-refractive-index layer 42b can be connected to the first high-refractive-index layer 41a, and the second high-refractive-index layer 41b can be connected to the second low-refractive-index layer 42b.

[0213] In addition, Figure 1 In this process, the anti-reflective film 1 has an anti-fouling layer 5, but is not limited to this.

[0214] That is to say, such as Figure 3 As shown, the anti-reflective film 1 may, for example, not have an anti-fouling layer 5.

[0215] Example

[0216] The following examples, comparative examples, and reference examples further illustrate the present invention in detail. It should be noted that the present invention is not limited to any particular example, comparative example, or reference example. Furthermore, the specific values ​​of proportions (including proportions), physical property values, parameters, etc., used in the following description can be replaced by the upper limits (defined as values ​​"below" or "less than") or lower limits (defined as values ​​"above" or "greater than") of the corresponding proportions (including proportions), physical property values, parameters, etc., described in the above-described "Specific Embodiments".

[0217] Example 1

[0218] <Production of Anti-reflective Film>

[0219] Make the anti-reflective film as shown below.

[0220] [Fabrication of transparent substrate film]

[0221] A mixture was prepared by mixing 100 parts by weight of a butyl acetate solution of a UV-curable urethane acrylate resin (trade name: LUXYDIR 17-806, solids concentration: 80% by mass, manufactured by DIC), 5 parts by weight of a photopolymerization initiator (trade name: IRGACURE906, manufactured by BASF), and 0.01 parts by weight of a leveling agent (trade name: GRANDIC PC4100, manufactured by DIC). Then, a mixed solvent of cyclopentanone (CPN) and propylene glycol monomethyl ether (PGM) (CPN to PGM mass ratio: 45:55) was added to adjust the solids concentration of the mixture to 36% by mass, thus obtaining a curable resin composition. This curable resin composition was coated onto one side of an 80 μm thick cellulose triacetate (TAC) film (trade name: KC8UA, manufactured by Konica Minolta Advanced Layers) with a dried thickness of 7 μm, and dried at 90°C for 1 minute. Then, irradiate with a high-pressure mercury lamp at a wavelength of 365nm and a cumulative light intensity of 300mJ / cm. 2 The ultraviolet light causes the coating layer to cure, forming a cured resin layer. This results in a transparent substrate film with a cured resin layer on top of a transparent resin film.

[0222] [Formation of the intermediate layer]

[0223] First, plasma treatment is performed on one side of the transparent substrate film in the thickness direction (the side with the cured resin layer in the thickness direction). A roll-to-roll sputtering apparatus is used for plasma treatment. Vacuum degassing is performed until the ultimate vacuum level in the plasma treatment chamber of the sputtering apparatus reaches 1.0 × 10⁻⁶. －4 After Pa, argon as a sputtering gas (inert gas) is introduced into the plasma treatment chamber. The pressure in the plasma treatment chamber is set to 0.5 Pa, and the discharge power is set to 0.15 kW. While conveying the transparent substrate film, plasma treatment is performed on one side of the thickness direction of the cured resin layer through glow discharge.

[0224] Next, an Al-Si-ZnO layer with a thickness of 86 nm was formed on one side of the transparent substrate film (the side of the cured resin layer) using reactive sputtering. x Intermediate layer. A roll-to-roll sputtering apparatus is used to form the intermediate layer. Details of the sputtering conditions used to form the intermediate layer are shown below.

[0225] Vacuum exhaust is performed until the ultimate vacuum level in the film-forming chamber of the sputtering film-forming apparatus reaches 1.0 × 10⁻⁶. －4After Pa, argon as the sputtering gas and oxygen as the reactive gas are introduced into the film-forming chamber, and the pressure in the film-forming chamber is set to 0.2 Pa. It should be noted that argon and oxygen are introduced into the film-forming chamber in a volume ratio of 100:4. Furthermore, as the target for the sputtering apparatus, a sintered body of alumina, zinc oxide, and silicon oxide is used, containing alumina, silicon oxide, and zinc oxide in a mass ratio of 3:20:77. As the power source for applying voltage to the target, an MFAC power supply is used, with the discharge power set to 6.0 kW, and the film-forming temperature (the temperature of the roller supporting the transparent substrate film for the formation of the intermediate layer) set to -5°C.

[0226] In this way, an intermediate layer is formed on one side of the transparent substrate film in the thickness direction (the side of the cured resin layer in the thickness direction).

[0227] [Formation of the anti-reflective layer]

[0228] Next, an antireflective layer is formed on one side of the intermediate layer in the thickness direction using reactive sputtering. The antireflective layer comprises, in sequence on the thickness-direction side: a titanium oxide layer (first layer), a silicon oxide layer (second layer), a titanium oxide layer (third layer), and a silicon oxide layer (fourth layer). A roll-to-roll magnetron sputtering apparatus is used to form the antireflective layer. Details of the sputtering conditions used to form the antireflective layer are shown below.

[0229] In the first layer of film formation, vacuum degassing is performed until the ultimate vacuum level in the film formation chamber of the sputtering film formation apparatus reaches 1.0 × 10⁻⁶. －4 After Pa, argon (a non-reactive gas) and oxygen (a reactive gas) are introduced into the film-forming chamber, and the pressure inside the chamber is set to 0.2 Pa. It should be noted that argon and oxygen are introduced into the film-forming chamber in a volume ratio of 100:8. Furthermore, titanium is used as the target for the sputtering apparatus. A HiPIMS power supply (product name: TruPlasma Highpulse 4002 G2, manufactured by TRUMPF) is used as the power source for applying voltage to the target. The discharge voltage is set to 1700V, the frequency to 210Hz, the pulse width to 35µs, and the film-forming temperature (the temperature of the roller supporting the transparent substrate film with the intermediate layer for forming the anti-reflective layer) to 100°C.

[0230] In the second layer of film formation, vacuum degassing is performed until the ultimate vacuum level in the film formation chamber of the sputtering film formation apparatus reaches 1.0 × 10⁻⁶. －4After Pa, argon (a non-reactive gas) and oxygen (a reactive gas) are introduced into the film-forming chamber, and the pressure inside the chamber is set to 0.2 Pa. It should be noted that argon and oxygen are introduced into the film-forming chamber in a volume ratio of 100:30. Furthermore, silicon is used as the target for the sputtering apparatus. An MFAC power supply is used as the power source for applying voltage to the target, with the discharge power set to 25 kW and the film-forming temperature (the temperature of the transparent substrate film containing the intermediate layer for forming the anti-reflective layer) set to 100 °C.

[0231] In the formation of the third layer, the same conditions as those for the formation of the first layer are set.

[0232] In the formation of the fourth layer, the same conditions as those for the formation of the second layer are set.

[0233] Thus, a laminate (anti-reflective layer) is formed on one side of the thickness direction of the intermediate layer, wherein the laminate (anti-reflective layer) comprises, in sequence on the side facing the thickness direction: a titanium oxide layer (first layer), a silicon oxide layer (second layer), a titanium oxide layer (third layer), and a silicon oxide layer (fourth layer).

[0234] [Formation of the antifouling layer]

[0235] Then, an 8 nm thick antifouling layer is formed on one side of the antireflective layer (the side of the silicon oxide layer (fourth layer) in the thickness direction) using vacuum evaporation. During the formation of the antifouling layer, vacuum degassing is performed until the ultimate vacuum level of the vacuum evaporation chamber reaches 1.0 × 10⁻⁶. －4 After Pa, antifouling layer material A (trade name: SHIN-ETSU SUBELYNKY 1903-1, active ingredient: alkoxysilane compound with perfluoropolyether group, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) is added into the crucible, and the crucible is heated under vacuum. It should be noted that the crucible is preheated beforehand, and antifouling layer material A is dried before being used for film formation. The heating temperature for film formation is set to 260℃.

[0236] It should be noted that the effective component in the antifouling layer material A is, specifically, the compound with a perfluoropolyether skeleton shown in the above chemical formula (1).

[0237] Thus, an anti-fouling layer is formed on one side of the thickness direction of the anti-reflective layer (the side of the thickness direction of the silicon oxide layer (fourth layer)).

[0238] As described above, an anti-reflective film is formed.

[0239] Comparative Example 1

[0240] In the formation of the first and third layers, niobium was used as the target of the sputtering apparatus, an MFAC power supply was used as the power source for applying voltage to the target, the discharge power was set to 25kW, and the film formation temperature (the temperature of the transparent substrate film with the intermediate layer for forming the antireflective layer) was set to 100°C. Otherwise, the antireflective film of Comparative Example 1 was produced in the same manner as the antireflective film of Example 1.

[0241] Comparative Example 2

[0242] In the formation of the first and third layers, an MFAC power supply was used as the power source for applying voltage to the target, the discharge power was set to 25kW, and the film formation temperature (the temperature of the transparent substrate film with the intermediate layer for forming the antireflective layer) was set to 100°C. Otherwise, the antireflective film of Comparative Example 2 was produced in the same manner as the antireflective film of Example 1.

[0243] Comparative Example 3

[0244] No intermediate layer is formed. Otherwise, the antireflective film of Comparative Example 3 is made in the same manner as the antireflective film of Comparative Example 1.

[0245] Comparative Example 4

[0246] No intermediate layer is formed; otherwise, it is implemented in the same manner as the antireflective film of Example 1.

[0247] Comparative Example 5

[0248] The third and fourth layers are not formed. Otherwise, the antireflective film of Comparative Example 5 is made in the same manner as the antireflective film of Comparative Example 1.

[0249] Comparative Example 6

[0250] No third or fourth layer is formed. Otherwise, the antireflective film of Comparative Example 6 is made in the same manner as the antireflective film of Comparative Example 2.

[0251] Comparative Example 7

[0252] No third or fourth layer is formed. Otherwise, the antireflective film of Comparative Example 7 is produced in the same manner as the antireflective film of Example 1.

[0253] <Evaluation>

[0254] [Determination of Refractive Index]

[0255] The antireflective films obtained in each example and comparative example were measured using a spectroscopic ellipsometry (product name: RC2, manufactured by JAWoollam Japan). After measurement, the refractive index was determined by fitting the measured spectra of polarization resolution parameters ψ and Δ with the simulated spectra calculated based on the optical model. As an optical model, a stacked structure consisting of a film, an intermediate layer, a titanium oxide layer, a silicon oxide layer, another titanium oxide layer, and a silicon oxide layer was set. The Cauchy dispersion formula was used to fit each layer, and the refractive index (n) when light with a wavelength of 550 nm is incident on each layer was measured. The results are shown in Table 1.

[0256] [Evaluation of Spectral Reflectance]

[0257] The antireflective films obtained in the examples and comparative examples were cut into 50 mm squares as evaluation samples. The spectral reflectance (wavelength: 380–780 nm, incident angle: 5°) of the evaluation samples, which were adhered to a black acrylic sheet with adhesive, was measured using a spectrophotometer (product name: UH-4150, manufactured by HITACHI HIGH TECH). The wavelength bands (unit: nm) with a spectral reflectance of less than 1% were determined. The results are shown in Table 1.

[0258] [Calculation of reflectivity Y]

[0259] Using the spectral reflectance of wavelengths from 380 to 780 nm as measured above and the relative spectral distribution of the CIE standard irradiation body D65, the light reflectance ratio (reflectance Y) of the object color caused by reflection in the XYZ color system specified in JIS Z 8701 was calculated.

[0260] [Reflected Hue]

[0261] Based on the XYZ color system obtained through reflected hue, a* and b* in the CIE-Lab color system are obtained by using the following formulas (1) to (3). The results are shown in Table 1.

[0262]

[0263]

[0264]

[0265] [Analysis of electron beam diffraction images]

[0266] Regarding the antireflective layers in the antireflective films obtained in each embodiment and comparative example, cross-sections of designated locations were prepared using the FIB microsampling method. The cross-sections were observed using an FE-TEM (product name: JEM-2800, manufactured by JEOL Corporation), and the thickness (d) of each layer from the first to the fourth layer was measured. Then, electron beam diffraction images were obtained from the cross-sections of the titanium oxide layers (first and third layers). Based on the interplanar spacing of the electron beam diffraction spots and the interplanar spacing in the ICDD data, the constituent layers of the titanium oxide layers (first and third layers) were analyzed, and the presence or absence of Ti2O3 diffraction patterns was investigated. The results are shown in Table 1.

[0267]

[0268] It should be noted that the above-described invention is provided as an example of an embodiment of the present invention, but it is merely an example and not a limiting interpretation. Modifications of the invention that are apparent to those skilled in the art are included in the claims.

[0269] Industrial availability

[0270] The anti-reflective film of the present invention can be used, for example, as a film disposed on the outermost surface of the display screen in image display devices such as liquid crystal displays and organic EL displays.

Claims

1. An antireflective film, comprising, sequentially on one side facing the thickness direction: a transparent substrate film, an intermediate layer, and an antireflective layer. The refractive index of the intermediate layer is greater than 1.7 and less than 1.9 when light with a wavelength of 550 nm is incident on it. The anti-reflective layer comprises two or more layers having a high refractive index layer and a low refractive index layer. The refractive index of the high refractive index layer is greater than 2.50 and less than 2.80 when light with a wavelength of 550 nm is incident on it.

2. The antireflective film according to claim 1, wherein, The high refractive index layer comprises a group of Ti2O3 diffraction spots that appear in electron beam diffraction images observed using a transmission electron microscope.

3. The antireflective film according to claim 1, wherein, The intermediate layer contains inorganic oxides.

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

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