Anti-reflective film

Abstract

The present invention provides an anti-reflective film with high adhesion between the base film and the anti-reflective layer, and excellent anti-reflective performance. [Solution] The anti-reflective film 1 comprises a base film 2, an adhesion layer 3, and an anti-reflective layer 4, arranged sequentially toward one side in the thickness direction. The anti-reflective layer 4 comprises a high refractive index layer 41 and a low refractive index layer 42. The maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film 1 is 0.1 μm or more. In a cross-sectional view of the anti-reflective film 1 in the thickness direction, the ratio of the second interface length at the interface between the high refractive index layer 41 and the low refractive index layer 42 to the first interface length at the interface between the base film 2 and the adhesion layer 3 is 1.06 or more.

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. As such an anti-reflective film, an anti-reflective film has been proposed that comprises a base film, a hard coat (HC) layer, a primer layer, and an anti-reflective layer in this order in the thickness direction (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 7515646 [Overview of the project] [Problems that the invention aims to solve]

[0004] In the anti-reflective film described in Patent Document 1, the HC layer contains microparticles with a particle diameter of 1 μm or more and nanoparticles with a particle diameter of 100 nm or less. As a result, the HC layer has surface irregularities on the primer layer side. The anchoring effect due to the surface irregularities of the HC layer and the physicochemical interaction between the nanoparticles and the primer layer improve the adhesion between the substrate film and the anti-reflective layer.

[0005] However, in the anti-reflective film described in Patent Document 1, the adhesion between the microparticles that form the surface irregularities and the primer layer is low, and peeling is particularly likely to occur in the convex portions on the surface where the microparticles are present.

[0006] The present invention aims to provide an anti-reflective film that exhibits high adhesion between the base film and the anti-reflective layer and has excellent anti-reflective performance. [Means for solving the problem]

[0007] The present invention [1] includes an anti-reflective film comprising a base film, an adhesion layer, and an anti-reflective layer in order toward one side in the thickness direction, wherein the anti-reflective layer comprises a high refractive index layer and a low refractive index layer, the maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film is 0.1 μm or more, and in a cross-sectional view of the anti-reflective film in the thickness direction, the ratio of the second interface length at the interface between the high refractive index layer and the low refractive index layer to the first interface length at the interface between the base film and the adhesion layer is 1.06 or more.

[0008] The present invention [2] includes the anti-reflective film described in [1], wherein the ratio is 1.35 or less.

[0009] The present invention [3] includes an anti-reflective film according to [1] or [2], further comprising an anti-fouling layer on one side in the thickness direction of the anti-reflective layer. [Effects of the Invention]

[0010] The anti-reflective film of the present invention has a maximum surface roughness Rz of 0.1 μm or more on one side of the exposed surface in the thickness direction of the anti-reflective film, and a ratio of the second interface length at the interface between the high refractive index layer and the low refractive index layer to the first interface length at the interface between the base film and the adhesion layer is 1.06 or more. Such an anti-reflective film has high adhesion between the base film and the anti-reflective layer and good anti-reflective performance. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 shows a cross-sectional view of a first embodiment of the anti-reflective film of the present invention. [Figure 2] Figure 2 is an enlarged view of Figure 1, showing the convex and concave portions in the cured resin layer of the anti-reflective film of the present invention. [Figure 3] Figure 3 shows a cross-sectional view of a second embodiment of the anti-reflective film of the present invention. [Figure 4] Figs. 4A to 4D show the method for manufacturing the antireflection film shown in Fig. 3. Fig. 4A shows the step of preparing the base film, Fig. 4B shows the step of forming the adhesion layer on one surface in the thickness direction of the base film, Fig. 4C shows the step of forming the antireflection layer on one side in the thickness direction of the base film, and Fig. 4D shows the step of forming the antifouling layer on one side in the thickness direction of the base film. [Figure 5] Fig. 5 is a schematic configuration diagram of an apparatus for carrying out the plasma treatment step and the film forming step in an example of the method for manufacturing the antireflection film shown in Fig. 3. [Figure 6] Fig. 6 is a perspective view showing the positional relationship between the low inductance antenna and the base film in the plasma treatment chamber shown in Fig. 5. [Figure 7] Fig. 7 is a cross-sectional view showing the positional relationship between the low inductance antenna and the base film in the plasma treatment chamber shown in Fig. 5. [Figure 8] Fig. 8 is a schematic diagram of an observation image of the cross-section of the antireflection film in Example 1. [Figure 9] Fig. 9 is a schematic diagram of an observation image of the cross-section of the antireflection film in Comparative Example 3.

Embodiments for Carrying Out the Invention

[0012] 1. Antireflection Film Referring to Fig. 1, the first embodiment of the antireflection film of the present invention will be described.

[0013] As shown in Fig. 1, the antireflection film 1 has a film shape (including a sheet shape) having a predetermined thickness. Further, the antireflection film 1 extends in the plane direction orthogonal to the thickness direction, and one surface and the other surface in the thickness direction of the antireflection film 1 are flat.

[0014] The anti-reflective film 1 comprises a base film 2, an adhesion layer 3, and an anti-reflective layer 4, arranged in order toward one side in the thickness direction. Specifically, as shown in Figure 1, the anti-reflective film 1 comprises a base film 2, an adhesion layer 3 disposed on one side of the base film 2 in the thickness direction, and an anti-reflective layer 4 disposed on one side of the adhesion layer 3 in the thickness direction.

[0015] <Base film> The base film 2 is a transparent, flexible film. The base film 2 is the bottom layer of the anti-reflective film 1.

[0016] The base film 2 comprises, for example, a transparent resin film 21 and a cured resin layer 22 in the thickness direction. Preferably, the base film 2 consists of a transparent resin film 21 and a cured resin layer 22. The base film 2 has a first surface 2a on one side in the thickness direction of the cured resin layer 22 and a second surface 2b on the other side in the thickness direction of the transparent resin film 21. In the first embodiment, the base film 2 can be a commercially available triacetylcellulose (TAC) film in the form of a long roll. For example, a long roll of high anti-glare AG base material (transparent resin film 21 with cured resin layer 22, product names: PFN60 0005NF and PF21-125, manufactured by Daicel Corporation) can be used.

[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 material for the transparent resin film 21 is, for example, cellulose resin, preferably TAC, from the viewpoint of transparency, heat resistance, and mechanical strength. In other words, the transparent resin film 21 is a TAC layer. The TAC layer is a layer made of TAC.

[0019] The thickness of the transparent resin film 21 is, for example, 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, and also, for example, 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less.

[0020] The cured resin layer 22 improves the mechanical properties of the anti-reflective film 1. The cured resin layer 22 is positioned on one side in the thickness direction of the transparent resin film 21 and on the other side in the thickness direction of the adhesion layer 3. Specifically, as shown in Figure 1, the cured resin layer 22 is positioned on one side in the thickness direction of the transparent resin film 21. In other words, the cured resin layer 22 is in contact with the transparent resin film 21.

[0021] The cured resin layer 22 is not particularly limited as long as it is a resin layer, preferably a resin layer having anti-glare properties. Examples of the cured resin layer 22 include a hard coat layer and an anti-blocking layer. The hard coat layer makes it difficult for scratches to form on the exposed surface of the transparent resin film 21. The anti-blocking layer provides anti-blocking properties to the surfaces of each of the multiple anti-reflective films 1 that come into contact with each other, such as when the anti-reflective films 1 are laminated in the thickness direction.

[0022] The cured resin layer 22 is a cured product of a curable resin composition containing 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. These curable resins may be used individually or in combination of two or more types. From the viewpoint of ensuring the hardness of the cured resin layer 22, the curable resin is preferably at least one selected from the group consisting of acrylic urethane resin and acrylic resin.

[0023] Examples of curable resins include UV-curable resins and thermosetting resins. Preferably, the curable resin is a UV-curable resin. When the curable resin is a UV-curable resin, it can be cured without high-temperature heating, thus improving the manufacturing efficiency of the anti-reflective film 1.

[0024] The cured resin layer 22 may contain nanoparticles with an average particle size of less than 1 μm and microparticles with an average particle size of 1 μm or more, to the extent that they do not affect the anti-glare properties of the anti-reflective film 1 and the adhesion between the substrate film 2 and the anti-reflective layer 4. Preferably, the cured resin layer 22 contains nanoparticles but does not contain microparticles. More preferably, the cured resin layer 22 does not contain nanoparticles or microparticles.

[0025] In a cross-sectional view of the anti-reflective film 1 in the thickness direction, the cured resin layer 22, as shown in Figure 2, although not shown in Figure 1, microscopically, includes a region that protrudes relatively to one side in the thickness direction relative to the surface direction (convex portion 22a) and a region that is relatively flat with respect to the surface direction (recessed portion 22b). Preferably, one surface in the thickness direction and the other surface in the thickness direction of the cured resin layer 22 are flat.

[0026] 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.

[0027] One surface in the thickness direction of the base film 2 (cured resin layer 22) may be surface modified. Preferably, it is surface modified. 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 is used. More preferably, treatment by inductively coupled plasma using an oxygen-containing gas generated by applying high-frequency power to a low-inductance antenna (oxygen-LIAICP treatment) is used. In other words, one surface in the thickness direction of the base film 2 (cured resin layer 22) is preferably a plasma-treated surface, more preferably a plasma-treated surface by a low-inductance antenna, and even more preferably an oxygen-LIAICP treated surface.

[0028] If one side of the base film 2 (cured resin layer 22) in the thickness direction is an oxygen-LIAICP treated surface, the adhesion between the base film 2 and the anti-reflective layer 4 described later can be increased, and glare can be suppressed by scattering ambient light on the surface of the base film 2.

[0029] The total light transmittance (JIS K-7105) of the base 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.

[0030] The thickness of the base film 2 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 150 μm or less, particularly preferably 130 μm or less.

[0031] <Close-up layer> The adhesion layer 3 ensures adhesion between the base film 2 and the anti-reflective layer 4. The adhesion layer 3 is positioned on one side in the thickness direction of the base film 2 and on the other side in the thickness direction of the anti-reflective layer 4. Specifically, as shown in Figure 1, the adhesion layer 3 is positioned on one side in the thickness direction of the base film 2 (one side in the thickness direction of the cured resin layer 22). In other words, the adhesion layer 3 is in contact with the base film 2 (cured resin layer 22).

[0032] The adhesion layer 3 is a dry coating layer, preferably a sputtered layer.

[0033] Examples of materials for the adhesion layer 3 include metals such as nickel, chromium, indium, aluminum, tin, gold, silver, platinum, zinc, titanium, tungsten, zirconium, and palladium; alloys of two or more of these metals; metalloids such as silicon; and one or more oxides thereof.

[0034] Examples of oxides include indium-containing conductive oxides, antimony-containing conductive oxides, and zinc-containing conductive oxides. Examples of indium-containing conductive 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 conductive oxide is antimony-tin composite oxide (ATO). An example of a zinc-containing conductive oxide is zinc-aluminum composite oxide (AZO).

[0035] The material for the adhesion layer 3 is preferably an oxide containing at least one element selected from the group consisting of indium, aluminum, tin, titanium, zirconium, and silicon. From the viewpoint of adhesion to the substrate film 2 and adhesion to the anti-reflective layer 4, the material for the adhesion layer 3 is preferably an indium-containing conductive oxide, more preferably ITO. In other words, the adhesion layer 3 is preferably an indium-containing conductive oxide layer, more preferably an ITO layer.

[0036] In ITO used as the material for the adhesion layer 3, the content of tin oxide relative to the total amount of indium oxide and tin oxide is, for example, 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, and also, for example, 30% by mass or less, preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0037] The thickness of the adhesion layer 3 is, for example, 0.1 nm or more, preferably 1 nm or more, more preferably 2 nm or more, even more preferably 3 nm or more, and also, for example, 20 nm or less, preferably 15 nm or less, more preferably 10 nm or less, even more preferably 6 nm or less.

[0038] If the thickness of the adhesion layer 3 is equal to or greater than the lower limit value mentioned above, the adhesion force between it and the base film 2, and the adhesion force between it and the anti-reflective layer 4 can be ensured.

[0039] <Anti-reflection layer> The anti-reflective layer 4 suppresses the reflection intensity of ambient light through interference between reflected light at the interfaces of multiple thin layers. Furthermore, by adjusting the optical film thickness (product of refractive index and thickness) of each thin layer, an interference effect that suppresses reflection intensity is achieved. The anti-reflective layer 4 is positioned on one side in the thickness direction of the adhesion layer 3. Specifically, as shown in Figure 1, the anti-reflective layer 4 is positioned on one side in the thickness direction of the adhesion layer 3. In other words, the anti-reflective layer 4 is in contact with the adhesion layer 3.

[0040] The anti-reflective layer 4 includes a laminate 10 comprising a high refractive index layer 41 and a low refractive index layer 42. Preferably, the outermost layer in the thickness direction of the anti-reflective layer 4 is the low refractive index layer 42.

[0041] 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. Preferably, the anti-reflective layer 4 includes two laminates 10 each comprising a high refractive index layer 41 and a low refractive index layer 42.

[0042] Specifically, as shown in Figure 1, the anti-reflective layer 4 includes a first laminate 10a comprising a first high refractive index layer 41a and a first low refractive index layer 42a, and a second laminate 10b comprising a second high refractive index layer 41b and a second low refractive index layer 42b.

[0043] More specifically, as shown in Figure 1, the first laminate 10a is arranged on one side in the thickness direction of the adhesion layer 3, and the second laminate 10b is arranged on one side in the thickness direction of the first laminate 10a.

[0044] In other words, the first high refractive index layer 41a is in contact with the adhesion layer 3. The first low refractive index layer 42a is in contact with the first high refractive index layer 41a. The second high refractive index layer 41b is in contact with the first low refractive index layer 42a. The second low refractive index layer 42b is in contact with the second high refractive index layer 41b.

[0045] In the anti-reflective film 1 of the first embodiment, the outermost layer in the thickness direction of the anti-reflective layer 4 is preferably the second low refractive index layer 42b. Therefore, in the anti-reflective film 1, the second low refractive index layer 42b is exposed on one side in the thickness direction. That is, the exposed surface on one side in the thickness direction of the anti-reflective film 1 is the one side in the thickness direction of the second low refractive index layer 42b.

[0046] When 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 reflectivity of the anti-reflective film 1 can be reduced over a wide wavelength range.

[0047] Examples of materials for the high refractive index layer 41 include niobium oxide, titanium oxide layer, zirconium oxide, indium tin composite oxide (ITO), and antimony tin composite oxide (ATO). Niobium oxide is preferred. In other words, the high refractive index layer 41 is preferably a niobium oxide layer. The niobium oxide layer is a layer made of niobium oxide.

[0048] 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 silicon oxide layer is a layer made of silicon oxide. That is, the outermost layer in the thickness direction of the anti-reflective layer 4 is preferably a silicon oxide layer.

[0049] The high refractive index layer 41 is a layer with a relatively high refractive index. Specifically, the refractive index of the high refractive index layer 41 at a wavelength of 550 nm is 1.9 or higher. The refractive index of the niobium oxide layer at a wavelength of 550 nm is 2.33.

[0050] The low refractive index layer 42 is a layer with a relatively small refractive index. Specifically, the refractive index of the low refractive index layer 42 at a wavelength of 550 nm is 1.6 or less. The refractive index of the silicon oxide layer at a wavelength of 550 nm is 1.46.

[0051] The thickness of the first high refractive index layer 41a is, for example, 1 nm or more, preferably 3 nm or more, more preferably 5 nm or more, even more preferably 10 nm or more, and also, for example, 50 nm or less, preferably 30 nm or less, more preferably 25 nm or less, even more preferably 20 nm or less.

[0052] The thickness of the second high refractive index layer 41b is, for example, 30 nm or more, preferably 50 nm or more, more preferably 70 nm or more, even more preferably 90 nm or more, and also, for example, 250 nm or less, preferably 200 nm or less, more preferably 150 nm or less, even more preferably 120 nm or less.

[0053] When the anti-reflective layer 4 comprises a first laminate 10a and a second laminate 10b, preferably the thickness of the first high refractive index layer 41a is thinner than the thickness of the second high refractive index layer 41b.

[0054] The thickness of the first low refractive index layer 42a is, for example, 15 nm or more, preferably 20 nm or more, more preferably 25 nm or more, and also, for example, 45 nm or less, preferably 40 nm or less, more preferably 35 nm or less.

[0055] The thickness of the second low refractive index layer 42b is, for example, 30 nm or more, preferably 50 nm or more, more preferably 70 nm or more, and also, for example, 150 nm or less, preferably 130 nm or less, more preferably 110 nm or less, and even more preferably 90 nm or less.

[0056] When the anti-reflective layer 4 comprises a first laminate 10a and a second laminate 10b, preferably the thickness of the first low refractive index layer 42a is thinner than the thickness of the second low refractive index layer 42b.

[0057] The optical film thickness (product of refractive index and thickness) of the first high refractive index layer 41a is, for example, 20 nm or more, and for example, 40 nm or less. The optical film thickness of the second high refractive index layer 41b is, for example, 200 nm or more, and for example, 300 nm or less.

[0058] The optical film thickness of the first low refractive index layer 42a 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 is, for example, 100 nm or more, and for example, 140 nm or less.

[0059] The total thickness of the anti-reflective layer 4 is, for example, 50 nm or more, preferably 100 nm or more, more preferably 150 nm or more, even more preferably 200 nm or more, and also, for example, 700 nm or less, preferably 500 nm or less, more preferably 300 nm or less, even more preferably 250 nm or less.

[0060] 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.

[0061] The thickness of the anti-reflective film 1 is, for example, 5 μm or more, preferably 10 μm or more, more preferably 30 μm or more, even more preferably 50 μm or more, and also, for example, 150 μm or less, preferably 120 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less.

[0062] The maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film 1 is 0.1 μm or more, preferably 0.4 μm or more, more preferably 1.0 μm or more, and even more preferably 1.5 μm or more. Alternatively, it may be 4.5 μm or less, preferably 3.9 μm or less, more preferably 3.5 μm or less, and even more preferably 3.0 μm or less.

[0063] The arithmetic mean roughness Ra of the exposed surface on one side in the thickness direction of the anti-reflective film 1 is 0.02 μm or more, preferably 0.08 μm or more, more preferably 0.15 μm or more, and even more preferably 0.2 μm or more. It is also 2.0 μm or less, preferably 1.0 μm or less, more preferably 0.8 μm or less, and even more preferably 0.7 μm or less.

[0064] The maximum roughness Rz and the arithmetic mean roughness Ra can be measured, for example, by surface shape measurement as described later.

[0065] If the maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film 1 is within the above range, then surface irregularities are formed on one side in the thickness direction of the base film 2. In other words, glare can be suppressed by scattering ambient light on the surface of the base film 2.

[0066] In a cross-sectional view of the anti-reflective film 1 in the thickness direction, the anti-reflective film 1 has an interface (first interface) between the base film 2 and the adhesion layer 3, and also an interface (second interface) between the high refractive index layer 41 and the low refractive index layer 42. The first interface and the second interface consist of irregularities on the order of nanometers. In a cross-sectional view of the anti-reflective film 1 in the thickness direction, the ratio (L2 / L1) of the second interface length L2 at the interface between the high refractive index layer 41 and the low refractive index layer 42 (second interface) to the first interface length L1 at the interface between the base film 2 and the adhesion layer 3 (first interface) is 1.06 or more, preferably 1.09 or more, and more preferably 1.12 or more. It is also 1.35 or less, preferably 1.28 or less, and more preferably 1.20 or less.

[0067] When the ratio (L2 / L1) is greater than or equal to the lower limit, the adhesion between the base film 2 and the anti-reflective layer 4 can be increased. Furthermore, when the ratio (L2 / L1) is less than or equal to the upper limit, glare can be suppressed by scattering ambient light in the anti-reflective layer 4.

[0068] The first interface length L1 and the second interface length L2 are determined by measuring the ratio of the interface lengths, as described later.

[0069] 2. Second Embodiment of Anti-Reflective Film A second embodiment of the anti-reflective film of the present invention will be described with reference to Figure 3.

[0070] The anti-reflective film 1 may further include an anti-fouling layer 5 on one side in the thickness direction of the anti-reflective layer 4. Specifically, as shown in Figure 3, the anti-reflective film 1 may include a base film 2, an adhesive layer 3 disposed on one side in the thickness direction of the base film 2, an anti-reflective layer 4 disposed on one side in the thickness direction of the adhesive layer 3, and an anti-fouling layer 5 disposed on one side in the thickness direction of the anti-reflective layer 4.

[0071] In the anti-reflective film 1 of the second embodiment, the outermost layer in the thickness direction of the anti-reflective layer 4 is the anti-fouling layer 5. Therefore, in the anti-reflective film 1, the anti-fouling layer 5 is exposed on one side in the thickness direction. In other words, the exposed surface on one side in the thickness direction of the anti-reflective film 1 is the one side in the thickness direction of the anti-fouling layer 5.

[0072] <Stain-resistant layer> The antifouling layer 5 suppresses the adhesion of contaminants such as hand grease to the exposed surface of the anti-reflective film 1 and makes it easier to remove contaminants. The antifouling layer 5 is a dry coating layer, preferably a vacuum-deposited layer. The antifouling layer 5 is arranged on one side in the thickness direction of the anti-reflective layer 4 (specifically, the second low refractive index layer 42b). In other words, the antifouling layer 5 is in contact with the anti-reflective layer 4 (specifically, the second low refractive index layer 42b).

[0073] Examples of materials for the antifouling layer 5 include organic compounds containing fluorine groups. Preferably, the organic compound containing fluorine groups is an alkoxysilane compound having a perfluoropolyether group. Examples of alkoxysilane compounds having a perfluoropolyether group include compounds represented by the following general formula (1). R 1 -R 2 -X-(CH2) m -Si(OR 3 )3(1) In general formula (1), R 1represents a linear or branched alkyl fluoride group (with carbon atoms, for example, 1 or more and 20 or less) in which one or more hydrogen atoms in the alkyl group are substituted by fluorine atoms, and preferably represents a perfluoroalkyl group in which all hydrogen atoms of the alkyl group are substituted by fluorine atoms.

[0074] R 2 represents a structure containing at least one repeating structure of a perfluoropolyether (PFPE) group, and preferably represents a structure containing two repeating structures of a PFPE group. Examples of the repeating structure of the PFPE group include the repeating structure of a linear PFPE group and the repeating structure of a branched PFPE group. Examples of the repeating structure of the linear PFPE group include, for example, a structure represented by -(OC n F 2n ) p - (where n represents an integer of 1 or more and 20 or less, and p represents an integer of 1 or more and 50 or less. The same applies hereinafter). Examples of the repeating structure of the branched PFPE group include, for example, a structure represented by -(OC(CF3)2) p - and a structure represented by -(OCF2CF(CF3)CF2) p -. The repeating structure of the PFPE group preferably includes the repeating structure of a linear PFPE group, and more preferably includes -(OCF2) p - and -(OC2F4) p -.

[0075] R 3 represents an alkyl group having 1 or more and 4 or less carbon atoms, and preferably represents a methyl group.

[0076] X represents an ether group, a carbonyl group, an amino group, or an amide group, and preferably represents an ether group.

[0077] m represents an integer of 1 or more. Also, m preferably represents an integer of 20 or less, more preferably 10 or less, and even more preferably 5 or less.

[0078] Examples of alkoxysilane compounds having a perfluoropolyether group include the compounds shown in the following general formula (2). 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.

[0079] Furthermore, the alkoxysilane compounds having a perfluoropolyether group may be used alone or in combination of two or more types.

[0080] 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.

[0081] 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.

[0082] The thickness of the antifouling layer 5 is, for example, 1 nm or more, preferably 3 nm or more, more preferably 4 nm or more, and even more preferably 6 nm or more. Alternatively, it may be 20 nm or less, preferably 15 nm or less, and more preferably 10 nm or less.

[0083] It is preferable that the refractive index of the antifouling layer 5 is small compared to the refractive index of the layer in contact with the antifouling layer 5. Specifically, when the antifouling layer 5 is in contact with the low refractive index layer 42 (silicon oxide layer), the refractive index of the antifouling layer 5 is, for example, 1.6 or less, preferably 1.55 or less, and more preferably 1.5 or less.

[0084] 3. Variations of anti-reflective film In Figure 1, the anti-reflective layer 4 includes, but is not limited to, two laminates 10, each comprising a high refractive index layer 41 and a low refractive index layer 42.

[0085] In other words, the anti-reflective layer 4 is not particularly limited as long as it includes at least one laminate 10 comprising a high refractive index layer 41 and a low refractive index layer 42. Specifically, the number of layers in the laminate 10 and the stacking order of the high refractive index layer 41 and the low refractive index layer 42 are not particularly limited.

[0086] 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.

[0087] 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 adhesion 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 adhesion 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.

[0088] 4. Method for manufacturing anti-reflective film Referring to Figures 4A to 4D, a second embodiment of the method for manufacturing the anti-reflective film 1 of the present invention will be described.

[0089] A method for manufacturing the anti-reflective film 1 includes, for example, a preparation step of preparing a base film 2 (Figure 4A), a plasma treatment step of plasma treatment of one surface of the base film 2 in the thickness direction, and a film formation step of forming an adhesion layer 3, an anti-reflective layer 4, and an anti-fouling layer 5 in that order on one side of the base film 2 in the thickness direction (Figures 4B, 4C, and 4D).

[0090] In the preparation step, the base film 2 is prepared as shown in Figure 4A. In this embodiment, a long roll of base film 2 is prepared. Specifically, the base film 2 is wound so that the first surface 2a faces inward in the radial direction of the roll.

[0091] In this embodiment, using the apparatus Y shown in Figure 5, the plasma treatment process and the film deposition process are sequentially carried out in a roll-to-roll manner while the substrate film 2 is transported as the work film W in a reduced-pressure atmosphere (roll-to-roll process).

[0092] The apparatus Y comprises a feed chamber R1, a connection chamber C1, a plasma processing chamber C2, a connection chamber C3, a film deposition chamber C4 (first film deposition chamber), a connection chamber C5, a film deposition chamber C6 (second film deposition chamber), and a winding chamber R2. The feed chamber R1, connection chamber C1, plasma processing chamber C2, connection chamber C3, film deposition chamber C4 (first film deposition chamber), connection chamber C5, film deposition chamber C6 (second film deposition chamber), and winding chamber R2 are arranged in this order and are in communication with each other.

[0093] The dispensing chamber R1 is equipped with a dispensing roller 51 for dispensing the work film W, and a predetermined number of guide rollers G for guiding the work film W. A roll of long base film 2 is attached to the dispensing roller 51 as the work film W.

[0094] The connection chamber C1 is located after the feed chamber R1 and before the plasma processing chamber C2 in the direction of travel of the work film W. The connection chamber C1 is equipped with a predetermined number of guide rollers G for guiding the work film W. The connection chamber C1 is connected to a vacuum pump (not shown) and its chamber pressure can be adjusted. When the apparatus Y is in operation, the pressure in the connection chamber C1 is maintained at a predetermined pressure between the pressure in the feed chamber R1 and the pressure in the plasma processing chamber C2. This ensures a differential pressure between the feed chamber R1 and the plasma processing chamber C2.

[0095] Plasma processing chamber C2 is located between connection chamber C1 and connection chamber C3 in the direction of travel of the work film W. Plasma processing chamber C2 is equipped with a first line L10 with a flow control valve for introducing gas into the chamber. The plasma processing process is carried out in plasma processing chamber C2.

[0096] In this embodiment, the plasma processing chamber C2 is equipped with a plurality of low-inductance antennas (LIAs) 71. An LIA is an antenna having a low inductance of 7.5 μH or less and generating inductively coupled plasma by the application of high-frequency power. In this embodiment, the LIAs 71 are supported by mounting fixtures 72 as shown in Figures 5 and 6, and are placed inside the plasma processing chamber C2, covered by a cover block 73 (omitted in Figure 6) (the case where there are 4 LIAs 71 is illustrated as an example).

[0097] As shown in Figure 6, multiple LIA71s are arranged in alignment so as to be aligned in the direction of travel of the base film 2 and in a direction perpendicular to the direction of travel (the width direction of the base film 2). The mounting fixture 72 is a vacuum flange. As shown in Figure 7, the LIA71s are fixed to the mounting fixture 72 via a field-through 74. As shown in Figure 5, the mounting fixture 72 is assembled into an opening 75 provided in the wall of the plasma processing chamber C2. Specifically, the mounting fixture 72 is assembled to the opening 75 with a sealing member (not shown) sandwiched between it and the wall of the plasma processing chamber C2. Outside the plasma processing chamber C2, the LIA71s are electrically connected to a high-frequency power supply (RF power supply) via an impedance matcher. Such LIA71s are formed of a conductor. Examples of conductors include copper and silver, with copper being preferred. The LIA71s may be covered with an insulator. Examples of insulators include glass and quartz.

[0098] As shown in Figure 7, the cover block 73 comprises a block body 73A and a plurality of partition plates 73B. The block body 73A has a plurality of storage spaces 73a. One LIA 71 is housed in each storage space 73a. The partition plates 73B are arranged to close the storage spaces 73a. The inside of the storage spaces 73a is a sealed space. In the cover block 73, the block body 73A is made of aluminum, for example. Examples of aluminum include aluminum A5052. The partition plates 73B are made of an insulating material. Examples of insulating materials include quartz and glass. The separation distance d' between the substrate film 2 that travels inside the plasma processing chamber C2 and the cover block 73 is, for example, 80 to 120 mm. With such a cover block 73, damage and contamination of the LIA 71 due to plasma processing can be avoided without excessively reducing the plasma conversion efficiency due to the power applied to the LIA 71, and damage to the substrate film 2 being plasma processed can be suppressed.

[0099] As shown in Figure 6, in this embodiment, the LIA71 has an open-loop shape. If the LIA71 has an open-loop shape, the inductance of the LIA71 can be reduced. Therefore, the open-loop LIA71 can suppress the increase in voltage due to an increase in the power applied to the LIA71. This can suppress abnormal discharge during plasma processing, which will be described later. By suppressing abnormal discharge, damage to the substrate film 2 being plasma processed can be suppressed. Specifically, the LIA71 has a U-shape with two free ends. For each LIA71, the two free ends are fixed to the mounting fixture 72 so that they are aligned in the width direction of the substrate film 2. In addition, in this embodiment, the LIA71 has an extension portion 71a on the side opposite to the two free ends. The extension portion 71a extends parallel to the substrate film 2 passing through the plasma processing chamber C2. The extension portion 71a extends in the width direction of the substrate film 2. Each extension 71a may extend in the direction of travel of the base film 2 (and four LIA71 may be arranged in this manner). The length of the extension 71a is, for example, 50 to 150 mm (Figure 6 illustrates an example where the length of the extension 71a is the same as the maximum length d2 of the LIA71, which will be described later). The LIA71 may be in a coil shape instead of an open loop shape.

[0100] The LIA 71 extends from the mounting fixture 72 toward the base film 2. Preferably, the LIA 71 extends perpendicular to the mounting fixture 72. The extension length d1 of the LIA 71 from the mounting fixture 72 is, for example, 30 to 150 mm. The maximum length d2 of the LIA 71 in the planar direction of the base film 2 is, for example, 50 to 150 mm. The separation distance d3 (shown in Figure 7) between the LIA 71 and the base film 2 is, for example, 50 to 200 mm. Preferably, the extension length d1 and the separation distance d3 are the same. The ratio of the separation distance d3 to the extension length d1 (d3 / d1) is, for example, 0.5 to 3.5. The number of LIA 71 (number of rows) arranged spaced apart in the running direction of the base film 2 may be 1, 2 or 3, or 4 or more if necessary, depending on the running speed of the base film 2 (i.e., plasma processing time). In the direction of travel of the base film 2, the distance d4 between the centers of adjacent LIA71 is, for example, 100 to 500 mm. In the width direction of the base film 2, the distance d5 between the centers of adjacent LIA71 is, for example, 100 to 500 mm. By adjusting the distance d5 between centers, the plasma current density in the width direction of the base film 2, as described later, can be uniformly controlled. It is preferable that the distances d4 and d5 between centers are the same. The ratio of the distance d5 to the distance d4 (d5 / d4) is, for example, 0.5 to 2.0. Preferably, the center points of the extensions 71a of the four LIA71 form a square with vertices. Such a set of LIA71 can generate high-density plasma. As the LIA71, for example, a high-frequency antenna for plasma generation described in Japanese Patent Application Publication No. 2013-258153 may be used.

[0101] In this embodiment, the plasma processing chamber C2 further includes a transport roller 53. The transport roller 53 is the main guide roller for transporting the work film W within the plasma processing chamber C2. The transport roller 53 has a temperature control function that allows heating or cooling of the work film W. In other words, the transport roller 53 is a transport roller with a temperature control function. When the apparatus Y is in operation, the transport roller 53 transports the base film 2 while in contact with the second surface 2b of the base film 2. The LIA 71 is positioned opposite the transport roller 53. With the apparatus Y equipped with such a plasma processing chamber C2, in the plasma processing process, plasma processing can be performed on the base film 2 while cooling or heating the base film 2 with the temperature control function transport roller 53 that contacts the base film 2. By controlling the temperature of the base film 2, thermal deformation of the base film 2 can be suppressed, and the influence of thermal deformation on the transport of the base film 2 can be suppressed.

[0102] The connection chamber C3 is positioned after the plasma processing chamber C2 and before the film deposition chamber C4 in the direction of travel of the work film W. The connection chamber C3 is equipped with a predetermined number of guide rollers G for guiding the work film W. The connection chamber C3 is connected to a vacuum pump (not shown) and can adjust the pressure inside the chamber. When the apparatus Y is in operation, the pressure inside the connection chamber C3 is maintained at a predetermined pressure between the pressure inside the plasma processing chamber C2 and the pressure inside the film deposition chamber C4. This ensures a differential pressure between the plasma processing chamber C2 and the film deposition chamber C4.

[0103] The deposition chamber C4 is located next to the connection chamber C3 in the direction of travel of the work film W. The deposition chamber C4 is also connected to a vacuum pump (not shown) and can adjust the vacuum level inside the chamber to a predetermined level. In the deposition chamber C4, the deposition process of the adhesion layer 3 and the first high refractive index layer 41a to the second low refractive index layer 42b is carried out.

[0104] In this embodiment, the deposition chamber C4 is a sputter deposition chamber. The deposition chamber C4 comprises a deposition roller 54 and a plurality of sputter chambers 60 (sputter chambers 60a to 60e) (the case where there are 5 sputter chambers 60 is illustrated as an example). The deposition roller 54 is the main guide roller for transporting the work film W within the deposition chamber C4. The deposition roller 54 has a temperature control function that allows heating or cooling of the work film W. That is, the deposition roller 54 is a deposition roller with a temperature control function. The sputter chambers 60 are partitioned spaces within the deposition chamber C4. The plurality of sputter chambers 60 are arranged along the circumferential direction of the deposition roller 54. Each sputter chamber 60 opens toward the deposition roller 54. A cathode 61 is provided inside the sputter chamber 60. A target (not shown) as a deposition material supply is placed on the cathode 61. The target is placed on the target so as to face the deposition roller 54. Each sputtering chamber 60 is equipped with a power supply (not shown) for applying voltage to the target to generate a glow discharge. Examples of power supplies include DC power supplies, AC power supplies, MF power supplies, RF power supplies, and MF-AC power supplies. An MF-AC power supply is an AC power supply with a frequency band of several kHz to several MHz. Each sputtering chamber 60 is connected to a necessary number of second lines (not shown) with flow control valves for introducing gas into the chamber. The deposition chamber C4 is also equipped with a predetermined number of guide rollers G for guiding the work film W.

[0105] The connection chamber C5 is located between the connection chamber C4 and the film deposition chamber C6 in the direction of travel of the work film W. The connection chamber C5 is equipped with a predetermined number of guide rollers G for guiding the work film W.

[0106] The deposition chamber C6 is located between the connection chamber C5 and the winding chamber R2 in the direction of travel of the work film W. In this embodiment, the deposition chamber C6 is a vacuum deposition chamber. The deposition chamber C6 includes a material holding section 62 and a deposition amount adjustment valve (not shown) whose opening degree can be controlled. The deposition chamber C6 is connected to a vacuum pump (not shown) and the chamber pressure can be adjusted. The deposition chamber C6 is equipped with a predetermined number of guide rollers G for guiding the work film W. The deposition process of the antifouling layer 5 is carried out in the deposition chamber C6.

[0107] In the material holding section 62, a film deposition material supply material (not shown), which is the material for the antifouling layer 5, is arranged facing the work film W being transported within the film deposition chamber C6. The material holding section 62 may have a built-in resistance heating means, a built-in high-frequency induction heating means, or an electron beam heating means as a means for heating the film deposition material supply material.

[0108] The winding chamber R2 is equipped with a winding roller 52 for winding the work film W, and a predetermined number of guide rollers G for guiding the work film W.

[0109] The plasma treatment process and the film deposition process are carried out sequentially using the apparatus Y described above. Specifically, the process is as follows:

[0110] The work film W is unfurled from the unfurling chamber R1. After being unfurled from the unfurling chamber R1, the work film W sequentially passes through the connection chamber C1, plasma processing chamber C2, connection chamber C3, film deposition chamber C4, connection chamber C5, and film deposition chamber C6, and is wound up in the winding chamber R2. The travel speed of the work film W is, for example, 0.5 m / min or more, and for example, 5 m / min or less. Furthermore, the entire line from the unfurling chamber R1 to the winding chamber R2 is kept under a reduced pressure atmosphere without being exposed to the atmosphere along the way. The reduced pressure atmosphere is preferably a vacuum. A vacuum is, for example, a reduced pressure atmosphere of 7 Pa or less.

[0111] In plasma treatment chamber C2, the plasma treatment process is carried out. In the plasma treatment process, the first surface 2a of the substrate film 2 is subjected to plasma treatment under a reduced-pressure atmosphere in plasma treatment chamber C2 (chamber). In this embodiment, the plasma treatment is performed by inductively coupled plasma of an oxygen-containing gas generated by applying high-frequency power to LIA71 (oxygen-LIAICP treatment). Specifically, it is as follows:

[0112] During plasma processing, oxygen is supplied to the plasma processing chamber C2 via the first line L10. In addition to oxygen, an inert gas may be supplied to the plasma processing chamber C2. Examples of inert gases include argon, krypton, and xenon. The gas in the plasma processing chamber C2 may also contain other gases besides the inert gas. Examples of other gases include nitrogen, hydrogen, and water vapor. The oxygen concentration of the gas (oxygen-containing gas) in the plasma processing chamber C2 is, for example, 30% by volume or more, preferably 50% by volume or more, more preferably 80% by volume or more, even more preferably 90% by volume or more, particularly preferably 95% by volume or more, and especially preferably 100% by volume. When the oxygen concentration is above the above lower limit, a high-density oxygen plasma can be generated. This is useful for creating nanometer-order fine irregularities on the first surface 2a of the substrate film 2 and for high activation by cleaning the first surface 2a.

[0113] The pressure inside the plasma processing chamber C2 during plasma processing (first pressure) is, for example, 0.1 Pa or more, preferably 0.2 Pa or more, more preferably 0.3 Pa or more, and also, for example, 7 Pa or less, preferably 5 Pa or less, more preferably 3 Pa or less. When the first pressure is above the lower limit, a plasma environment with sufficient density for surface modification treatment of the first surface 2a of the substrate film 2 can be formed inside the plasma processing chamber C2 during plasma processing. When the first pressure is below the upper limit, thermal damage to the first surface 2a caused by excessively high-density plasma can be suppressed during plasma processing, and excessive roughening of the first surface 2a can also be suppressed. Suppression of excessive roughening helps to suppress a decrease in the mechanical strength of the first surface 2a. The first pressure can be adjusted by the amount of oxygen gas supplied into the plasma processing chamber C2.

[0114] The frequency of the high-frequency power applied to LIA71 during plasma processing is, for example, 1 MHz or higher, preferably 5 MHz or higher, more preferably 10 MHz or higher, and also, for example, 100 MHz or lower, preferably 80 MHz or lower, more preferably 60 MHz or lower. When the frequency is above the lower limit, the plasma discharge can be stabilized while increasing the plasma current density during plasma processing. When the frequency is below the upper limit, the antenna potential can be suppressed, and therefore, damage to the substrate film 2 by the plasma can be suppressed. The high-frequency power is, for example, 0.1 kW or higher, preferably 0.3 kW or higher, more preferably 1.0 kW or higher, and also, for example, 10 kW or lower, preferably 8 kW or lower, more preferably 6 kW or lower. When the high-frequency power is above the lower limit, a high-density plasma environment can be formed in the plasma processing chamber C2 during plasma processing by inductively coupled plasma. When the high-frequency power is below the upper limit, excessive damage to the substrate by the plasma can be suppressed.

[0115] In the plasma treatment process, the plasma current density at the intermediate position between LIA71 and the substrate film 2 is, for example, 1.0 mA / cm². 3 Preferably, 2.0 mA / cm² 3More preferably, 2.5 mA / cm² 3 In addition, for example, 10mA / cm 3 Preferably, 8 mA / cm 3 More preferably, 4 mA / cm 3 The following is true: Plasma processing using inductive coupling with a low-inductance antenna can achieve a higher plasma current density than the capacitive coupling method described above (for example, a plasma density approximately 100 times higher can be achieved). When the plasma current density is above the lower limit, sufficient plasma-induced oxygen particles can be secured in the plasma processing chamber C2 during plasma processing, and the first surface 2a of the substrate film 2 can be appropriately surface-modified. When the plasma current density is below the upper limit, damage to the first surface 2a by excessively high-density plasma-induced oxygen particles can be suppressed during plasma processing. Methods for adjusting the plasma current density include, for example, adjusting the amount of oxygen gas introduced into the plasma processing chamber C2, adjusting the frequency of the high-frequency power in the high-frequency power supply, and adjusting the magnitude of the applied power.

[0116] In the film deposition process, first, in the film deposition chamber C4, following the plasma treatment process, an adhesion layer 3 is formed on the first surface 2a of the substrate film 2 by sputtering under a reduced pressure atmosphere. The reduced pressure atmosphere is preferably a vacuum.

[0117] In the sputtering method, a sputtering gas (inert gas) is introduced into each sputtering chamber 60 via a second line, while a negative voltage is applied to the target (film deposition material) placed on the cathode 61 within the sputtering chamber 60. This generates a glow discharge, ionizing the gas atoms, which then collide with the target surface at high speed, ejecting the target material from the target surface and depositing it onto the work film W. Examples of sputtering gases include argon, krypton, and xenon.

[0118] When the film deposition material is an oxide, the sputtering method may be a reactive sputtering method. In the reactive sputtering method, oxygen (reactive gas) is introduced into the sputtering chamber 60 in addition to the sputtering gas. The oxygen is introduced into the sputtering chamber 60 via another second line. The amount of oxygen introduced per 100 parts by volume of argon from sputtering chamber 60a to sputtering chamber 60e is, for example, 2% by volume or more, preferably 3% by volume or more, more preferably 4% by volume or more, and also, for example, 45% by volume or less, preferably 40% by volume or less, more preferably 35% by volume or less. In the reactive sputtering method, the target is, for example, an oxide that forms each layer.

[0119] In the sputtering method, the pressure in the sputtering chamber 60 (second pressure) is, for example, 0.1 to 5.0 Pa, depending on the type of layer to be formed. The film deposition temperature (temperature of the work film W, which is temperature-controlled by the film deposition roller 54) is, for example, -10°C to 150°C. The discharge power is, for example, 5 kW or more, preferably 8 kW or more, more preferably 10 kW or more, and also, for example, 40 kW or less, preferably 35 kW or less, more preferably 30 kW or less.

[0120] In the film deposition process, first, an adhesion layer 3 is formed on one side in the thickness direction of the substrate film 2 by sputtering in sputtering chamber 60a (see Figure 4B). When forming an ITO layer as the adhesion layer 3, an ITO target is used as the target placed on the cathode 61 in sputtering chamber 60a. Then, reactive sputtering is performed while introducing argon and oxygen into sputtering chamber 60a (similarly, reactive sputtering is performed in the following sputtering methods in sputtering chambers 60b to 60e).

[0121] Next, a first high refractive index layer 41a is formed on one side in the thickness direction of the adhesion layer 3 by sputtering in the sputtering chamber 60b. When forming an Nb2O5 layer as the first high refractive index layer 41a, an Nb target is used as the target placed on the cathode 61 in the sputtering chamber 60b.

[0122] Next, a first low refractive index layer 42a is formed on one side in the thickness direction of the first high refractive index layer 41a by sputtering in the sputtering chamber 60c. When forming an SiO2 layer as the first low refractive index layer 42a, a Si target is used as the target placed on the cathode 61 in the sputtering chamber 60c.

[0123] Next, a second high refractive index layer 41b is formed on one side in the thickness direction of the first low refractive index layer 42a by sputtering in the sputtering chamber 60d. When forming an Nb2O5 layer as the second high refractive index layer 41b, an Nb target is used as the target placed on the cathode 61 in the sputtering chamber 60d.

[0124] Next, a second low refractive index layer 42b is formed on one side in the thickness direction of the second high refractive index layer 41b by sputtering in the sputtering chamber 60e. When forming an SiO2 layer as the second low refractive index layer 42b, a Si target is used as the target placed on the cathode 61 in the sputtering chamber 60e (see Figure 4C).

[0125] In the film deposition process, an antifouling layer 5 is further formed in the deposition chamber C6 (see Figure 4D). In this step, the antifouling layer 5 is formed on one side in the thickness direction of the second low refractive index layer 42b of the work film W by vacuum deposition as a dry coating method in the deposition chamber C6. Specifically, with the deposition chamber C6 reduced to a vacuum by operating a vacuum pump, the deposition material supply material (not shown) placed in the material holding section 62 is heated to a predetermined temperature, and the vacuum deposition method is performed.

[0126] In apparatus Y, after the plasma treatment process and the film formation process, the anti-reflective film 1, which is the work film W, enters the winding chamber R2 and is wound up by the winding roller 52.

[0127] The anti-reflective film 1 of the present invention is manufactured as described above.

[0128] (Effects and Benefits) The anti-reflective film 1 produced as described above has a ratio of the second interface length at the interface between the high refractive index layer 41 and the low refractive index layer 42 to the first interface length at the interface between the base film 2 and the adhesion layer 3 of 1.06 or more, and the maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film 1 is 0.1 μm or more. As a result, when a sliding test is performed on the anti-reflective layer 4 using cloth or the like under ultraviolet irradiation, peeling of the anti-reflective layer 4 from the base film 2 can be suppressed (i.e., the adhesion between the base film 2 and the anti-reflective layer 4 is high), and furthermore, it has excellent anti-reflective performance. [Examples]

[0129] 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.

[0130] [Example 1] The anti-reflective film of Example 1 was prepared as shown below.

[0131] First, a long roll of high-glare-resistant AG substrate (product name: PFN60 0005NF, manufactured by Daicel Corporation) (AG1) was prepared as a substrate film comprising a transparent resin film and a cured resin layer. The substrate film used in Example 1 has a transparent resin film of TAC and does not contain microparticles in the cured resin layer.

[0132] Next, while conveying the substrate film in a roll-to-roll manner under vacuum, a plasma treatment process and a subsequent film deposition process were carried out on the substrate film (roll-to-roll process). For the plasma treatment process and the film deposition process, an apparatus (first apparatus) capable of performing a roll-to-roll process on the work film was used. The first apparatus comprises a feeding chamber, a plasma treatment chamber (first plasma treatment chamber), a first film deposition chamber, a second film deposition chamber, and a winding chamber. The feeding chamber, the first plasma treatment chamber, the first film deposition chamber, the second film deposition chamber, and the winding chamber are arranged in this order and are in communication with each other. The feeding chamber is equipped with a feeding roller. A roll of the substrate film described above was set on the feeding roller as the work film. The first plasma treatment chamber is equipped with a transport roller with a temperature control function (transport roller 53 in Figure 5) and four low-inductance antennas (LIA71 in Figures 6 and 7) covered with a cover block (cover block 73 in Figure 7), as shown in Figures 6 and 7. Each low-inductance antenna has an extension (extension 71a in Figure 6) parallel to the substrate film. For the four low-inductance antennas, the extension length d1 is 88 mm, the maximum length d2 (length of the extension) is 100 mm, the separation distance d3 is 112 mm, the center-to-center distance d4 is 290 mm, and the center-to-center distance d5 is 280 mm (Figures 6 and 7). Each low-inductance antenna is electrically connected to a high-frequency power supply (RF power supply, frequency 13.56 MHz) via an impedance matching device outside the first plasma processing chamber. The separation distance d' between the substrate film and the cover block running inside the first plasma processing chamber is 100 mm. The first deposition chamber is a sputter deposition chamber and comprises a deposition roller (deposition roller 54 in Figure 5) and the first to fifth sputter chambers (sputter chambers 60a to 60e in Figure 5). Each sputter chamber is a partitioned space within the first deposition chamber. The first to fifth sputtering chambers are arranged in this order along the circumferential direction of the film deposition roller and in the direction of travel of the substrate film. Each sputtering chamber is equipped with a cathode positioned opposite the film deposition roller. Each sputtering chamber is connected to a second line (not shown) with the necessary number of flow control valves for introducing gas into the chamber.The second deposition chamber is a vacuum deposition chamber and is equipped with a material holding section (material holding section 62 in Figure 5). The winding chamber is equipped with winding rollers.

[0133] In the roll-to-roll process, the first plasma treatment chamber subjected the surface (first surface) of the cured resin layer of the substrate film to plasma treatment (plasma treatment step). The substrate film travel speed (film travel speed) was set to 1.0 m / min. The temperature of the temperature-controlled transport roller was set to -8°C. The plasma treatment conditions were as follows:

[0134] The ultimate vacuum level in the first plasma processing chamber is 1.0 × 10⁻⁶ -4 After evacuating the apparatus to a vacuum of Pa, oxygen was introduced into the first plasma processing chamber, and the pressure inside the first plasma processing chamber was set to 1.5 Pa. By applying a high-frequency power of 2 kW to four low-inductance antennas using a high-frequency power supply, an inductively coupled plasma of oxygen-containing gas was formed around the antennas (this plasma treated the surface (first surface) of the cured resin layer of the substrate film). The plasma current density at the intermediate position between the low-inductance antennas and the substrate film was 1.3 mA / cm². 3 The plasma current density was measured using a Langmuir probe for plasma measurement.

[0135] In the first deposition chamber, an adhesion layer, a first high refractive index layer, a first low refractive index layer, a second high refractive index layer, and a second low refractive index layer were sequentially formed on the substrate film after plasma treatment. Specifically, while the substrate film was being transported and cooled by the deposition roll in the first deposition chamber, an adhesion layer was formed on the cured resin layer of the substrate film in the first sputtering chamber, a first high refractive index layer was formed on the adhesion layer in the second sputtering chamber, a first low refractive index layer was formed on the first high refractive index layer in the third sputtering chamber, a second high refractive index layer was formed on the first low refractive index layer in the fourth sputtering chamber, and a second low refractive index layer was formed on the second high refractive index layer in the fifth sputtering chamber. The deposition temperature (temperature of the deposition roll) was -8°C. More specifically, it is as follows.

[0136] In the first sputtering chamber, a 4 nm thick ITO layer was formed as an adhesion layer using reactive sputtering. In this process, the vacuum level achieved in the first deposition chamber was 1.0 × 10⁻⁶. -4 After evacuating to a vacuum of Pa, argon as an inert gas and oxygen as a reactive gas were introduced into the first sputtering chamber, and the pressure inside the first sputtering chamber was set to 0.2 Pa. The amount of oxygen introduced per 100 volumes of argon into the first sputtering chamber was 10 volumes. A sintered body of indium oxide and tin oxide (ITO with a tin oxide concentration of 10 mass%) was used as the target. An MF-AC power supply was used to apply voltage to the target (the same was used in the second to fifth sputtering chambers described later). The discharge power was set to 4.3 kW.

[0137] In the second sputtering chamber, a 14 nm thick Nb2O5 layer (refractive index 2.33) was formed as the first high refractive index layer using reactive sputtering. In this process, after the first deposition chamber was evacuated as described above, argon as an inert gas and oxygen as a reactive gas were introduced into the second sputtering chamber, and the pressure in the second sputtering chamber was set to 0.5 Pa. The amount of oxygen introduced per 100 volumes of argon into the second sputtering chamber was 5 volumes. An Nb target was used as the target. The discharge power was 13 kW.

[0138] In the third sputtering chamber, a 28 nm thick SiO2 layer (refractive index 1.46) was formed as the first low refractive index layer using reactive sputtering. In this process, after the first deposition chamber was evacuated as described above, argon as an inert gas and oxygen as a reactive gas were introduced into the third sputtering chamber, and the pressure in the third sputtering chamber was set to 0.2 Pa. The amount of oxygen introduced per 100 volumes of argon into the third sputtering chamber was 30 volumes. A Si target was used as the target. The discharge power was set to 25 kW.

[0139] In the fourth sputtering chamber, a 105 nm thick Nb2O5 layer (refractive index 2.33) was formed as the second high refractive index layer using reactive sputtering. In this process, after the first deposition chamber was evacuated as described above, argon as an inert gas and oxygen as a reactive gas were introduced into the fourth sputtering chamber, and the pressure in the fourth sputtering chamber was set to 0.5 Pa. The amount of oxygen introduced per 100 volumes of argon into the fourth sputtering chamber was 13 volumes. An Nb target was used as the target. The discharge power was 27.5 kW.

[0140] In the fifth sputtering chamber, an 84 nm thick SiO2 layer (refractive index 1.46) was formed as the second low refractive index layer using reactive sputtering. In this process, after the first deposition chamber was evacuated as described above, argon as an inert gas and oxygen as a reactive gas were introduced into the fifth sputtering chamber, and the pressure inside the fifth sputtering chamber was set to 0.2 Pa. The amount of oxygen introduced per 100 volumes of argon into the fifth sputtering chamber was 30 volumes. A Si target was used as the target. The discharge power was 20.5 kW.

[0141] In the second deposition chamber, an antifouling layer was formed on the second low refractive index layer. Specifically, an 8 nm thick antifouling layer was formed on the second low refractive index layer by vacuum deposition using a perfluoropolyether group-containing alkoxysilane compound as the deposition source. The deposition source was the solid content obtained by drying the perfluoropolyether group-containing alkoxysilane compound represented by the above general formula (2) (trade name: KY1903-1, solid content concentration 20% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.). The heating temperature of the deposition source in the vacuum deposition method was set to 260°C.

[0142] As described above, the anti-reflective film of Example 1 was fabricated. The anti-reflective film of Example 1 comprises a base film with a cured resin layer, an adhesion layer on the cured resin layer, an anti-reflective layer (first high refractive index layer / first low refractive index layer / second high refractive index layer / second low refractive index layer) on the adhesion layer, and an anti-fouling layer on the anti-reflective layer. The surface of the cured resin layer of the base film of the anti-reflective film of Example 1 is plasma treated. This plasma treatment is an inductively coupled plasma treatment using an oxygen-containing gas generated by applying high-frequency power to a low-inductance antenna (oxygen-LIAICP treatment).

[0143] [Example 2] The anti-reflective film of Example 2 was prepared in the same manner as in Example 1, except that a long roll of high-anti-glare AG substrate (product name: PF21-125, manufactured by Daicel Corporation) (AG2) was prepared as the base film. The base film used in Example 2 is a transparent resin film of TAC and does not contain microparticles in the cured resin layer.

[0144] [Comparative Example 1] First, a base film was prepared, the same as in Example 1.

[0145] Next, under vacuum, the substrate film was transported using a roll-to-roll method while a plasma treatment process and a subsequent film deposition process were carried out on the substrate film (roll-to-roll process). For the plasma treatment and film deposition processes, a device (second device) capable of performing a roll-to-roll process on the work film was used. The second device has the same configuration as the first device, except that it is equipped with a second plasma treatment chamber instead of the first plasma treatment chamber. The second plasma treatment chamber is equipped with a pair of planar electrodes for plasma generation, namely a cathode electrode and an anode electrode (both rectangular electrodes made of SUS304). The pair of planar electrodes are spaced 50 mm apart and arranged parallel to the substrate film passing through the second plasma treatment chamber. The anode electrode is positioned 35 mm away from the substrate film passing through the plasma treatment chamber and is grounded outside the plasma treatment chamber. The cathode electrode is positioned opposite the surface of the cured resin layer of the substrate film and is electrically connected to a high-frequency power supply (RF power supply, frequency 13.56 MHz) via an impedance matching device. Each electrode facing the base film has a length of 110 mm in the film travel direction and a length of 430 mm in the width direction.

[0146] In the roll-to-roll process, the surface (first surface) of the cured resin layer of the substrate film was plasma-treated (bombardment treatment) in the second plasma treatment chamber. The substrate film travel speed (film travel speed) was set to 1.0 m / min. The plasma treatment conditions were as follows:

[0147] The ultimate vacuum level in the second plasma processing chamber is 1.0 × 10⁻⁶ -4 After evacuating the apparatus to a vacuum of 0.5 Pa, argon was introduced into the second plasma processing chamber, and the pressure inside the second plasma processing chamber was set to 0.5 Pa. By applying 500 W of power from a high-frequency power supply between the planar electrodes, a capacitively coupled plasma (CCP) was generated. Under this plasma environment, bombardment treatment with argon ions was performed on the surface of the cured resin layer of the substrate film.

[0148] In the first deposition chamber, layers from the adhesion layer to the second low refractive index layer were sequentially formed on the substrate film after plasma treatment, in the same manner as described above for Example 1.

[0149] In the second deposition chamber, an antifouling layer was formed on the second low refractive index layer, similar to the method described above for Example 1.

[0150] As described above, the anti-reflective film of Comparative Example 1 was prepared. The base film of the anti-reflective film of Comparative Example 1 has a plasma-treated surface of the cured resin layer. This plasma treatment is a capacitively coupled plasma treatment (Ar-BB treatment) using argon-containing gas, which is generated by applying power between planar electrodes.

[0151] [Comparative Example 2] The anti-reflective film of Comparative Example 2 was prepared in the same manner as in Comparative Example 1, except that AG3 was used as the base film. The base film used in Comparative Example 2 contains microparticles in the cured resin layer.

[0152] A 60% by mass dispersion of colloidal silica (nanoparticles) with an average primary particle size of 40 nm was added to a urethane acrylate-based photocurable resin composition (product name: Beamset 577, manufactured by Arakawa Chemical Industries, Ltd.) such that the amount of silica was 40 parts by mass per 100 parts by mass of the resin component. To 100 parts by mass of the solid content of this solution, 5.0 parts by mass of silicone particles (product name: Tospar 130, average particle size 3.0 μm, refractive index 1.43, true specific gravity 1.32, manufactured by Momentive Performance Materials Japan), 2.0 parts by mass of organic smectite as a thixotropy agent (product name: Smecton SAN, manufactured by Kunimine Industries Co., Ltd.), 3.0 parts by mass of a photopolymerization initiator (product name: OMNIRAD907, manufactured by IGM Resins), and 0.15 parts by mass of a silicone-based leveling agent (product name: Polyflow LE303, solid content concentration 40% by mass, manufactured by Kyoeisha Chemical Co., Ltd.) were mixed and diluted with ethyl acetate to prepare a curable resin composition with a solid content concentration of 30% by mass.

[0153] The above curable resin composition was applied to a 60 μm thick triacetylcellulose (TAC) film (product name: Fujitac TG60UL, manufactured by Fujifilm Corporation) using a comma coater (registered trademark), and heated at 60°C for 1 minute. Afterward, a high-pressure mercury lamp was used to apply an integrated light intensity of 300 mJ / cm². 2 The coated layer was cured by irradiating it with ultraviolet light to form a 6.0 μm thick anti-glare cured resin layer.

[0154] [Comparative Example 3] The anti-reflective film of Comparative Example 3 was prepared in the same manner as in Example 1, except that the same base film as in Comparative Example 2 was used.

[0155] [Comparative Example 4] The anti-reflective film of Comparative Example 4 was prepared in the same manner as in Comparative Example 1, except that Clear HC1 was used as the base film. The base film used in Comparative Example 4 does not contain microparticles in the cured resin layer.

[0156] A curable resin composition with a solid content of 42% was prepared by mixing 83 parts by mass of an acrylic monomer composition containing nanosilica particles (product name: NC035HS, solid content concentration 60% by mass, manufactured by Arakawa Chemical Industries, Ltd.), 17 parts by mass of a UV-curable polyfunctional urethane acrylate (product name: Beamset 580, solid content concentration 70% by mass, manufactured by Arakawa Chemical Industries, Ltd.), 1.5 parts by mass of a photopolymerization initiator (product name: OMNIRAD127D, manufactured by IGM Resins, Inc.), 0.15 parts by mass of a silicone-based leveling agent (product name: Polyflow LE303, solid content concentration 40% by mass, manufactured by Kyoeisha Chemical Co., Ltd.), and butyl acetate.

[0157] The above curable resin composition was applied to an 80 μm thick TAC film (product name: Fujitac TG60UL, manufactured by Fujifilm Corporation) using a comma coater (registered trademark), and heated at 80°C for 3 minutes. Afterward, a high-pressure mercury lamp was used to apply an integrated light intensity of 200 mJ / cm². 2 The coated layer was cured by irradiating it with ultraviolet light to form a 5.0 μm thick anti-glare cured resin layer.

[0158] [Comparative Example 5] A comparative anti-reflective film for Comparative Example 5 was prepared in the same manner as in Example 1, except that Clear HC2 was used as the base film. The base film used in Comparative Example 5 does not contain microparticles in the cured resin layer.

[0159] A mixture was prepared by mixing 100 parts by mass (based on solid content) of a butyl acetate solution of UV-curable acrylic urethane resin (product name: Luxidia 17-806, solid content concentration 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). A mixed solution of cyclopentanone (CPN) and propylene glycol monomethyl ether (PGM) (mass ratio of CPM to PGM: 45:55) was added to the mixture to prepare a curable resin composition with a solid content concentration of 36%.

[0160] The above curable resin composition was applied to a 40 μm thick TAC film (product name: KC4UY, manufactured by Konica Minolta Advanced Layer Co., Ltd.) using a comma coater (registered trademark), and heated at 90°C for 1 minute. Subsequently, a high-pressure mercury lamp was used to apply an integrated light intensity of 300 mJ / cm². 2 The coated layer was cured by irradiating it with ultraviolet light to form an anti-glare cured resin layer with a thickness of 7.0 μm.

[0161] [Comparative Example 6] The anti-reflective film of Comparative Example 6 was prepared in the same manner as in Example 1, except for the following:

[0162] In the plasma treatment process, argon was introduced instead of oxygen into the first plasma treatment chamber to perform the treatment. This plasma treatment is an inductively coupled plasma treatment (Ar-LIAICP treatment) using argon-containing gas generated by applying high-frequency power to a low-inductance antenna.

[0163] <Measuring the ratio of interface lengths> For each of the anti-reflective films in Examples 1-2 and Comparative Examples 1-6, the ratio of the second interface length L2 at the interface between the high-refractive-index layer and the low-refractive-index layer to the first interface length L1 at the interface between the base film and the adhesion layer was measured in a cross-sectional view in the thickness direction. Specifically, the results are as follows:

[0164] First, a sample for cross-sectional observation of the anti-reflective film was prepared using the FIB microsampling method. For the FIB microsampling method, an FIB device (product name: FB2200, manufactured by Hitachi) was used, and the acceleration voltage was set to 10kV. Next, the cross-section of the sample was observed using FE-TEM. For this observation, an FE-TEM device (product name: JEM-2800, manufactured by JEOL) was used, and the acceleration voltage was set to 200kV. Figure 8 schematically shows the observed image of the cross-section of the sample from Example 1. In the observed image from Example 1, the cured resin layer 22 of the base film 2, the adhesion layer 3, the first high refractive index layer 41a as the first high refractive index layer, the first low refractive index layer 42a as the first low refractive index layer, the second high refractive index layer 41b as the second high refractive index layer, and the second low refractive index layer 42b as the second low refractive index layer were observed. Figure 9 schematically shows the observed image of the cross-section of the sample from Comparative Example 3. In the observation image of Comparative Example 3, the cured resin layer 22' of the base film 2', the adhesion layer 3', the first high refractive index layer 41a', the first low refractive index layer 42a', the second high refractive index layer 41b', and the second low refractive index layer 42b' were observed. Next, the observation image was analyzed using the image processing software ImageJ. This allowed us to determine the first interface length L1 (thick line in Figures 8 and 9) at the interface between the base film 2 (2') and the adhesion layer 3 (3') in the 274 nm image width range of the observation image (cross-sectional view), and the second interface length L2 (thick line in Figures 8 and 9) at the interface between the first high refractive index layer 41a (41a') and the first low refractive index layer 42a (42a'). Then, the ratio of the second interface length L2 to the first interface length L1 (L2 / L1) was calculated. The above measurements were performed in two fields of view: the convex portion 22a and the concave portion 22b of the cured resin layer 22(22'). The values ​​are shown in Table 1.

[0165] <Adhesion evaluation> The adhesion of the anti-reflective layer was investigated by performing the following UV+IPA sliding tests (Test 1 and Test 2) on each of the anti-reflective films in Examples 1-2 and Comparative Examples 1-6.

[0166] UV + IPA sliding test Exam 1: First, the base film side of the anti-reflective film was fixed to the glass plate. Next, the anti-reflective layer of the anti-reflective film on the glass plate was subjected to an irradiation intensity (integrated illuminance from 290nm to 450nm) of 150mW / cm² at a temperature of 85°C, relative humidity of 45%, and an irradiation intensity of 150mW / cm². 2 Under these conditions, the sample was exposed to light for 32.5 hours (accelerated weathering test). This test was performed using an accelerated weathering tester (product name: iSuper UV Tester SUV-W161, manufactured by Iwasaki Electric Co., Ltd.).

[0167] Second Exam: A polyester wiper (product name: Anticon Gold, manufactured by Sanplatec) was slid across the surface of an anti-reflective film while isopropyl alcohol was continuously dropped at a rate of 2 mL / min. The wiper contact surface was 20 mm x 20 mm, the load was 1.5 kg / 20 mm square, the sliding speed was 50 mm / second, and 10 reciprocating motions were performed. Next, the surface was observed using a 20x optical microscope to check for any peeling. A result of "good" was given if no peeling occurred at all, "poor" if peeling occurred partially, such as on raised areas, and "severely poor" if the peeling rate was 80% or more. The results are shown in Table 1.

[0168] <Surface shape measurement> Each anti-reflective film obtained using the above procedure was cut to a size of 5 cm x 5 cm to prepare a sample for measurement. Next, a 1.3 mm thick slide glass (product name: MICRO SLIDE GLASS, 45 mm x 50 mm, manufactured by MATSUNAMI Co., Ltd.) was bonded to the main surface (the surface without the anti-reflective layer) of the base film side of the sample for measurement, via a 20 μm thick acrylic adhesive layer. Then, using a stylus-type surface roughness measuring instrument (product name: SurfCorder ET4000, manufactured by Kosaka Laboratory Co., Ltd.) equipped with a diamond tip (radius of curvature R=2 μm), the surface shape of the antifouling layer surface of the sample (specifically, the main surface of the antifouling layer opposite to the anti-reflective layer) was measured in a certain direction under the conditions of a scanning speed of 0.1 mm / second and a measurement length of 4 mm. The obtained measurement data was analyzed using a program attached to the measuring instrument, and the maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film was determined from the roughness curve obtained through a wide-area filter with a cutoff value of 0.8 mm, in accordance with JIS B0601:2001. The results are shown in Table 1.

[0169] <Reflection> To obtain evaluation samples, a 1 mm thick black acrylic resin plate was bonded to the main surface (the side without the anti-reflective layer) of each anti-reflective film obtained using the above procedure, via a 20 μm thick acrylic adhesive layer. Next, in a darkroom with an illuminance of 1000 Lx (equivalent to a typical office environment using a display), a three-wavelength fluorescent lamp placed 50 cm directly above the anti-reflective film of the evaluation sample was turned on. The surface of the anti-reflective film was then visually observed, and the presence or absence of reflection from the fluorescent tube was checked according to the following criteria. If no reflection from the fluorescent tube was observed, it was evaluated as case A (reflection of external light reflection is suppressed), and if reflection from the fluorescent tube was observed, it was evaluated as case B or C (reflection of external light reflection is not suppressed). The results are shown in Table 1. A: The outline of the fluorescent tube cannot be seen on the surface of the anti-reflective film. B: The outline of the fluorescent tube can be faintly seen on the surface of the anti-reflective film. C: The outline of the fluorescent tube can be clearly seen on the surface of the anti-reflective film.

[0170] <Consideration> In the anti-reflective films of Examples 1 and 2, the ratio of the second interface length L2 to the first interface length L1 (L2 / L1) is 1.06 or greater in both the convex and concave portions of the cured resin layer, and the maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film is 0.1 μm or greater. Therefore, the adhesion between the base film and the anti-reflective layer in the anti-reflective film is high, and it has good anti-reflective performance. Accordingly, in the anti-reflective film of the present invention, by having L2 / L1 of 1.06 or greater in both the convex and concave portions, the adhesion between the base film and the anti-reflective layer in the anti-reflective film can be increased.

[0171] In the anti-reflective films of Comparative Examples 1-3 and 6, the ratio of the second interface length L2 to the first interface length L1 (L2 / L1) is less than 1.06 in both the convex and concave portions of the cured resin layer. Therefore, the adhesion between the base film and the anti-reflective layer in the anti-reflective films is poor.

[0172] In the anti-reflective film of Comparative Example 5, the maximum surface roughness Rz on one side of the exposed surface in the thickness direction of the anti-reflective film is less than 0.1 μm. Therefore, the anti-reflective performance of the anti-reflective film is inferior.

[0173] In the anti-reflective film of Comparative Example 4, the ratio of the second interface length L2 to the first interface length L1 (L2 / L1) is less than 1.06 in both the convex and concave portions of the cured resin layer, and the maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film is less than 0.1 μm. Therefore, the anti-reflective performance of the anti-reflective film is inferior.

[0174] [Table 1] [Explanation of Symbols]

[0175] 1. Anti-reflective film 2. Base film 3. Adhesion layer 4 Anti-reflection layer 5. Anti-fouling layer 10 Laminate 21 Transparent resin film 22 Cured resin layer 41 High refractive index layer 42 Low refractive index layer L1 1st interface length L2 2nd interface length

Claims

1. An anti-reflective film comprising a base film, an adhesion layer, and an anti-reflective layer in order toward one side in the thickness direction, The anti-reflective layer comprises a high refractive index layer and a low refractive index layer. The maximum roughness Rz of the exposed surface on one side in the thickness direction of the anti-reflective film is 0.1 μm or more. An anti-reflective film in which, in a cross-sectional view in the thickness direction of the anti-reflective film, the ratio of the second interface length at the interface between the high refractive index layer and the low refractive index layer to the first interface length at the interface between the base film and the adhesion layer is 1.06 or more.

2. The anti-reflective film according to claim 1, wherein the ratio is 1.35 or less.

3. The anti-reflective film according to claim 1 or 2, further comprising an anti-fouling layer on one side in the thickness direction of the anti-reflective layer.

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