Anti-reflective film and eye shields

Abstract

By suppressing the deformation of the micro-textured structure due to water absorption, it achieves both anti-fog and anti-reflective functions. [Solution] An anti-reflective film 1 is provided, comprising an optical functional layer 11 made of resin, the optical functional layer 11 having a fine uneven structure 12 including protrusions 13 or recesses 14 arranged at a pitch less than or equal to the wavelength of visible light, the indentation modulus of the optical functional layer 11 being 45 MPa or more, the water absorption rate of the optical functional layer 11 being 11% by mass or more, and the water contact angle of the surface of the optical functional layer 11 being 65° or more.

Description

Technical Field

[0001] The present invention relates to an antireflection film and an eye shield.

Background Art

[0002] Base materials constituting medical eye shields, industrial protective glasses, camera cover glasses, etc. are required to have an antifogging function and an antireflection function. As techniques for imparting an antifogging function, a technique of heating the surface of the base material, a technique of laminating a hydrophilic film on the surface of the base material, and a technique of laminating a water-absorbent film on the surface of the base material have been proposed. The technique of heating the surface of the base material exhibits an antifogging function by heating and evaporating fine water droplets adhering to the surface of the base material. The technique of laminating a hydrophilic film on the surface of the base material exhibits an antifogging function by spreading fine water droplets with the hydrophilic film to form a thin water film. The technique of laminating a water-absorbent film on the surface of the base material exhibits an antifogging function by absorbing fine water droplets with the water-absorbent film.

[0003] Among the above techniques for imparting an antifogging function, the technique of heating the surface of the base material has problems such as the apparatus becoming large and being inapplicable to eye shields, protective glasses, and camera cover glasses. Further, in the technique of laminating a hydrophilic film on the surface of the base material, as the time of contact with high-humidity outside air becomes longer, the thickness of the water film increases. Then, there is a problem that the water film becomes large water droplets and falls off from the hydrophilic film.

[0004] Therefore, as a technique for imparting an antifogging function to base materials constituting medical eye shields, industrial protective glasses, camera cover glasses, etc., a technique of laminating a water-absorbent film has been studied. As a technique of laminating a water-absorbent film, for example, Patent Document 1 discloses a technique of applying a film made of polyurethane having an oxyethylene group and having a water absorption rate of 15% by weight or more and 30% by weight or less to a glass base material.

[0005] On the other hand, as a technology for providing anti-reflective properties, for example, Patent Document 2 discloses a technology for providing a film having a micro-rough structure on its surface, in which multiple minute protrusions are arranged in a row, to the surface of a substrate. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 4992894 [Patent Document 2] Patent No. 6391935 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In order to achieve both anti-fogging and anti-reflective properties, it is conceivable to form the fine uneven structure described in Patent Document 2 using the material with a high water absorption rate described in Patent Document 1.

[0008] However, if a micro-textured structure is formed using a material with a high water absorption rate, the protrusions of the micro-textured structure will swell and soften and collapse when the structure absorbs water. This results in a physical deformation of the micro-textured structure, which impairs its anti-reflective function.

[0009] Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to provide an anti-reflective film and an eye shield that can suppress deformation of the fine uneven structure due to water absorption and achieve both anti-fogging and anti-reflective functions. [Means for solving the problem]

[0010] To solve the above problems, according to one aspect of the present invention, It has an optical functional layer made of resin, The optical functional layer has a fine uneven structure including protrusions or recesses arranged at a pitch less than or equal to the wavelength of visible light. The indentation modulus of the optical functional layer is 45 MPa or higher. The water absorption rate of the optical functional layer is 11% by mass or more. An anti-reflective film is provided in which the water contact angle of the surface of the optical functional layer is 65° or more.

[0011] The resin forming the optical functional layer may consist of a cured product of an uncured resin composition. The uncured resin composition may also contain silicone having acrylic functional groups.

[0012] The Martens hardness of the optical functional layer may be 3 MPa or higher.

[0013] The resin forming the optical functional layer may consist of a cured product of an uncured resin composition. The uncured resin composition may contain an acrylate monomer having one or both of an ethylene oxide group and an acrylamide group.

[0014] The number of repeating units of the ethylene oxide group in the acrylate monomer having the ethylene oxide group may be 4 or more and 20 or less.

[0015] The content of the acrylate monomer having an ethylene oxide group in the uncured resin composition may be 90% by mass or less.

[0016] The content of acrylate monomers having acrylamide groups in the uncured resin composition may be 50% by mass or less.

[0017] The resin forming the optical functional layer may consist of a cured product of an uncured resin composition. The uncured resin composition may contain polyfunctional acrylate monomers.

[0018] The content of polyfunctional acrylate monomer in the uncured resin composition may be 10% by mass or more.

[0019] Further comprising a substrate, The optical functional layer may be provided on the substrate.

[0020] The optical functional layer may have an anti-fogging function.

[0021] In order to solve the above problems, according to an aspect of the present invention, An eye shield including the anti-reflection film described above is provided.

Effect of the Invention

[0022] As described above, according to the present invention, it is possible to suppress deformation of the fine uneven structure due to water absorption and achieve both an anti-fogging function and an anti-reflection function.

Brief Description of the Drawings

[0023] [Figure 1] It is a cross-sectional view schematically showing an anti-reflection film according to an embodiment of the present invention. [Figure 2] It is a flowchart showing a procedure for calculating the water absorption rate according to the embodiment. [[ID=XXX]] [Figure 3] It is a perspective view schematically showing a master disk according to the embodiment. [Figure 4] It is a schematic diagram showing the configuration of a transfer device for manufacturing a transfer using the master disk according to the embodiment.

Modes for Carrying Out the Invention

[0024] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0025] [1. Configuration of Anti-Reflection Film] First, with reference to Figure 1, the configuration of the anti-reflective film 1 according to one embodiment of the present invention will be described. Figure 1 is a schematic cross-sectional view showing the anti-reflective film 1 according to this embodiment.

[0026] As shown in Figure 1, the anti-reflective film 1 comprises, for example, a substrate 10 and an optical functional layer 11. The optical functional layer 11 is provided on the substrate 10. The optical functional layer 11 has a fine uneven structure 12 on its surface. The fine uneven structure 12 has a plurality of fine protrusions 13 or recesses 14 arranged at a pitch of visible light wavelength (for example, 380 nm or more and 830 nm or less).

[0027] The base material 10 constitutes the base material of the anti-reflective film 1. The base material 10 is, for example, a flexible film-like base material. Therefore, the entire anti-reflective film 1 is also flexible. The base material 10 may be, for example, a flat film as shown in Figure 1, or a curved or corrugated film. The planar shape (XY plane), size, and thickness (Z direction) of the base material 10 are not particularly limited, but are preferably adjusted as appropriate depending on the application of the anti-reflective film 1.

[0028] The base material 10 is formed of, for example, a transparent material, preferably a transparent organic material. The base material 10 is preferably formed of a resin material with excellent light transmittance, and in particular, a resin material with excellent visible light transmittance. "Transparent" means that the transmittance of light having wavelengths belonging to the visible light range (for example, 380 nm or more and 830 nm or less) is high, and for example, the visible light transmittance may be 70% or more, preferably 90% or more. The visible light transmittance can be measured by a spectrophotometer. The measurement results can be used to calculate the transmittance from wavelengths of 380 nm to 900 nm according to JIS R 3106:1998, and the visible light transmittance can be calculated as the average of the transmittances in these wavelength ranges.

[0029] Examples of organic resins for the substrate 10 include polyethylene terephthalate (PET), polycarbonate, polymethyl methacrylate, triacetylcellulose (TAC), cyclic olefin polymer (COP), or cyclic olefin copolymer (COC).

[0030] Furthermore, the substrate 10 may be formed from an inorganic material with excellent visible light transmittance. For example, the substrate 10 may be formed from a transparent glass material such as quartz glass, soda-lime glass, or lead glass.

[0031] The optical functional layer 11 is a layer laminated on the substrate 10. The optical functional layer 11 is made of resin. The material of the optical functional layer 11 will be described in detail later. A micro-textured structure 12 having fine irregularities (protrusions 13 and recesses 14) is formed on the surface of the optical functional layer 11.

[0032] The micro-textured structure 12 may be, for example, a structure having nano-order fine irregularities formed on the surface of the substrate 10 (a so-called moth-eye structure). The pitch (average period) of the irregularities of the micro-textured structure 12 is less than or equal to the wavelength of visible light (for example, 380 nm or more and 830 nm or less). The micro-textured structure 12 has the function of preventing light reflection on the surface of the anti-reflective film 1 (anti-reflective function). By providing such a micro-textured structure 12, the anti-reflective film 1 will have an anti-reflective function.

[0033] The micro-textured surface 12 is provided on at least one surface of the substrate 10. In the example shown in Figure 1, the micro-textured surface 12 is provided only on one surface of the substrate 10 (i.e., surface 10A). However, the example is not limited to this, and for example, the micro-textured surface 12 may be provided on both surfaces of the substrate 10 (i.e., surface 10A and back surface 10B).

[0034] The micro-textured structure 12 has a plurality of protrusions 13 and a plurality of recesses 14. The protrusions 13 are projection-like structures that protrude perpendicularly from the surface of the substrate 10. The recesses 14 are the recessed portions between adjacent protrusions 13. The size and arrangement pitch of the protrusions 13 are, for example, on the order of nanometers (tens of nanometers or more and hundreds of nanometers or less).

[0035] In order to exhibit the anti-reflective function of visible light, etc., by the micro-textured structure 12, the protrusions (protrusions 13 and recesses 14) of the micro-textured structure 12 are arranged on the surface of the substrate 10 at a pitch less than or equal to the wavelength of visible light. In other words, the pitch of the multiple protrusions 13 constituting the micro-textured structure 12 is less than or equal to the wavelength of visible light. For example, if the wavelength range of visible light (i.e., the visible light range) is, for example, 380 nm or more and 830 nm or less, then the pitch is 380 nm or less.

[0036] In the micro-textured structure 12, the average distance between adjacent protrusions 13, 13 is preferably 5 nm or more and 1000 nm or less, more preferably 10 nm or more and 500 nm, and even more preferably 50 nm or more and 300 nm. Also, in the micro-textured structure 12, the average distance between adjacent recesses 14, 14 is preferably 5 nm or more and 1000 nm or less, more preferably 10 nm or more and 500 nm, and even more preferably 50 nm or more and 300 nm. This improves the anti-reflective function of the optical functional layer 11.

[0037] Furthermore, in the fine uneven structure 12, the average height of the protrusions 13 is preferably 1 nm or more and 1000 nm or less, more preferably 5 nm or more and 500 nm or less, even more preferably 10 nm or more and 300 nm or less, and particularly preferably 50 nm or more and 300 nm or less. This improves the transferability and peelability of the master disc in the transfer process described later, and improves the production efficiency of the optical functional layer 11. It also improves the anti-reflective function of the optical functional layer 11.

[0038] By providing a micro-rough structure 12 consisting of multiple protrusions 13 arranged at the minute pitch described above on the surface of the optical functional layer 11, a moth-eye structure with excellent visible light anti-reflection properties can be formed on the surface of the anti-reflective film 1. This creates an effective refractive index gradient at the interface between the optical functional layer 11 and the outside air. Therefore, light (visible light, etc.) incident on the surface of the anti-reflective film 1 and passing through the micro-rough structure 12 is gently refracted, and surface reflection is suppressed.

[0039] Furthermore, the micro-textured structure 12 according to this embodiment is preferably arranged in a hexagonal lattice pattern on the surface of the substrate 10 (on the XY plane) with a plurality of protrusions 13 arranged at the vertices and center of a hexagon. This allows for the arrangement of numerous protrusions 13 to densely fill the surface of the substrate 10 (on the XY plane), thereby improving the anti-reflective function as a moth-eye structure. However, the plurality of protrusions 13 of the micro-textured structure 12 are not limited to the hexagonal lattice pattern described above, and may be regularly arranged in other forms, such as a square lattice, rectangular lattice, or triangular lattice. Alternatively, the plurality of protrusions 13 may be irregularly arranged on the surface of the substrate 10. For example, the plurality of protrusions 13 may be irregularly arranged at positions that are randomly shifted from the reference position within a predetermined range of variation, while still being based on the various lattice-like arrangements described above.

[0040] Furthermore, as shown in Figure 1, the fine uneven structure 12 may be formed only on one surface (surface 10A) of the substrate 10, and not on the other surface (back surface 10B). This suppresses the reflection of incident light on surface 10A of the substrate 10, and suppresses the reflection of incident light on one surface of the anti-reflective film 1.

[0041] Furthermore, although not shown in the figures, if a fine uneven structure 12 is formed on both surfaces of the substrate 10 (front surface 10A and back surface 10B), the reflection of incident and outgoing light on the front surface 10A and back surface 10B of the substrate 10 can be suppressed. Although not shown in the figures, the fine uneven structure 12 may be provided on one surface of the substrate 10, and a multilayer anti-reflective coating may be provided on the other surface.

[0042] Furthermore, the anti-reflective film 1 according to this embodiment does not necessarily have a base material 10. In other words, the anti-reflective film 1 may consist only of the optical functional layer 11.

[0043] Furthermore, it is preferable that the optical functional layer 11 according to this embodiment has an anti-fogging function in addition to the anti-reflective function described above.

[0044] [2. Characteristics of the Optical Functional Layer] Next, the characteristics of the optical functional layer 11 according to this embodiment will be described. The optical functional layer 11 according to this embodiment has the following characteristics (A), characteristics (B), and characteristics (C). Furthermore, it is preferable that the optical functional layer 11 according to this embodiment has the following characteristics (D) and characteristics (E) in addition to characteristics (A), characteristics (B), and characteristics (C).

[0045] (A) Compression modulus The indentation modulus according to this embodiment is calculated by the Oliver & Pharr method based on a curve fitted to the maximum load in the range of 40% to 98% of the unloading curve obtained by pressing a Vickers indenter against the surface of the optical functional layer 11 using an indentation tester. In this embodiment, the indentation modulus is calculated based on the unloading curve obtained under the conditions of a load of 0.5 mN / 10 seconds, holding time of 10 seconds, and unloading of 0.5 mN / 10 seconds. The indentation tester is, for example, a nanoindentation tester manufactured by Anton Paar, product name "Hit 300".

[0046] The indentation modulus of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is 45 MPa or more, preferably 100 MPa or more, more preferably 150 MPa or more, and even more preferably 200 MPa or more. If the indentation modulus of the optical functional layer 11 is less than 45 MPa, when the optical functional layer 11 absorbs water, the protrusions 13 of the micro-textured structure 12 swell and soften and collapse. As a result, the micro-textured structure 12 is physically deformed, and the anti-reflective function of the micro-textured structure 12 is impaired. In addition, because the micro-textured structure 12 is deformed, the transparency of the optical functional layer 11 decreases. Since the indentation modulus of the optical functional layer 11 according to this embodiment is 45 MPa or more, deformation of the micro-textured structure 12 due to water absorption can be suppressed. Therefore, the decrease in the anti-reflective function of the optical functional layer 11 can be suppressed, and the decrease in transparency can also be suppressed.

[0047] Furthermore, the indentation modulus of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is, for example, 5000 MPa or less, preferably 4000 MPa or less, more preferably 3500 MPa or less, and even more preferably 1000 MPa or less. If the indentation modulus of the optical functional layer 11 exceeds 5000 MPa, cracks will occur in the optical functional layer 11 after transfer. Since the indentation modulus of the optical functional layer 11 according to this embodiment is 5000 MPa or less, it is possible to avoid the situation in which cracks occur in the optical functional layer 11 after transfer.

[0048] Furthermore, the indentation modulus of the optical functional layer 11 according to this embodiment may be the indentation modulus measured by the measurement method specified in ISO 14577. In other words, the indentation modulus of the optical functional layer 11 according to this embodiment obtained by the measurement method specified in ISO 14577 may be 45 MPa or more and 5000 MPa or less.

[0049] (B) Water absorption rate The water absorption rate according to this embodiment is calculated by the procedure shown in Figure 2. Figure 2 is a flowchart showing the procedure for calculating the water absorption rate according to this embodiment. As shown in Figure 2, first, in step S1, the optical functional layer 11 is exposed to an environment of 23°C and 50% RH for 24 hours or more. Next, in step S12, the mass M1 of the optical functional layer 11 is measured. Subsequently, in step S14, the optical functional layer 11 is immersed in distilled water at 23°C for 24 hours or more. Then, in step S16, the optical functional layer 11 is removed from the distilled water and any moisture adhering to the surface is removed. Subsequently, in step S18, the mass M2 of the optical functional layer 11 is measured. Finally, in step S20, the water absorption rate of the optical functional layer 11 is calculated using the following formula (A). Water absorption rate [mass%] = (mass M2 - mass M1) / mass M1 × 100 ...Formula (A)

[0050] The water absorption rate of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is 11% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more. If the water absorption rate of the optical functional layer 11 is less than 11% by mass, the anti-fogging function of the optical functional layer 11 will be reduced. Since the water absorption rate of the optical functional layer 11 according to this embodiment is 11% by mass or more, it is possible to exhibit the anti-fogging function.

[0051] Furthermore, the water absorption rate of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less. If the water absorption rate of the optical functional layer 11 exceeds 50% by mass, the optical functional layer 11 itself will whiten (become cloudy) when it absorbs water, and the transparency of the optical functional layer 11 will decrease. Since the water absorption rate of the optical functional layer 11 according to this embodiment is 50% by mass or less, whitening of the optical functional layer 11 itself when it absorbs water can be prevented. Therefore, a decrease in the transparency of the optical functional layer 11 can be prevented.

[0052] (C) Water contact angle The water contact angle according to this embodiment is measured using a contact angle meter and the droplet method under the following conditions. Amount of water added: 1.0 μL Measurement temperature: 25℃ Based on the measurement taken 10 seconds after dropping water onto the surface of the optical functional layer 11, the water contact angle of the optical functional layer 11 is calculated using the θ / 2 method.

[0053] The contact angle meter in question is, for example, the "Contact Angle Meter DMe-700" manufactured by Kyowa Interface Chemical Co., Ltd.

[0054] The water contact angle of the surface of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is 65° or more, preferably 80° or more, more preferably 100° or more, and even more preferably 120° or more. When the optical functional layer 11 absorbs water, the protrusions 13 of the micro-textured structure 12 may swell and soften and collapse. If the water contact angle of the surface of the optical functional layer 11 is less than 65°, when the collapsed protrusions 13 come into contact with each other, they will stick together, and even if water is removed from the optical functional layer 11 and the swelling subsides, the physical deformation of the micro-textured structure 12 will be maintained, thus impairing the anti-reflective function of the micro-textured structure 12. In addition, because the micro-textured structure 12 deforms, the transparency of the optical functional layer 11 decreases. The water contact angle of the surface of the optical functional layer 11 according to this embodiment is 65° or more. Therefore, even if the protrusions 13 of the fine uneven structure 12 swell and soften and collapse due to water absorption by the optical functional layer 11, and the protrusions 13 come into contact with each other, sticking of the protrusions 13 can be prevented. As a result, when the water is removed and the swelling subsides, the optical functional layer 11 according to this embodiment can restore the fine uneven structure 12 to its original shape. Consequently, a decrease in the anti-reflective function of the optical functional layer 11 can be suppressed, and a decrease in transparency can also be suppressed.

[0055] The water contact angle of the surface of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is preferably 150° or less. This makes it possible to manufacture the optical functional layer 11 according to this embodiment at low cost and efficiently.

[0056] In this embodiment, the water contact angle of the surface of the optical functional layer 11 may be the water contact angle measured by the measurement method specified in JIS R 3257 (1999). In other words, the water contact angle of the surface of the optical functional layer 11 obtained by the measurement method specified in JIS R 3257 (1999) may be 65° or more and 150° or less.

[0057] (D) Martens hardness In this embodiment, the Martens hardness is calculated by dividing the test load applied when a Vickers indenter is pressed against the surface of the optical functional layer 11 using an indentation tester by the surface area into which the Vickers indenter penetrates the optical functional layer 11. The test load is, for example, the maximum test load. In this embodiment, the Martens hardness is calculated based on the conditions of a load of 0.5 mN / 10 seconds, a holding time of 10 seconds, and an unloading time of 0.5 mN / 10 seconds. The indentation tester is, for example, an Anton Paar nanoindentation tester, product name "Hit 300".

[0058] The Martens hardness of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is, for example, 3 MPa or more, preferably 5 MPa or more, more preferably 10 MPa or more, and even more preferably 15 MPa or more. If the Martens hardness of the optical functional layer 11 is less than 3 MPa, when the optical functional layer 11 absorbs water, the protrusions 13 of the micro-textured structure 12 swell and soften and collapse. As a result, the micro-textured structure 12 is physically deformed, and the anti-reflective function of the micro-textured structure 12 is impaired. In addition, because the micro-textured structure 12 is deformed, the transparency of the optical functional layer 11 decreases. Since the Martens hardness of the optical functional layer 11 according to this embodiment is 3 MPa or more, deformation of the micro-textured structure 12 due to water absorption can be suppressed. Therefore, the decrease in the anti-reflective function of the optical functional layer 11 can be suppressed, and the decrease in transparency can also be suppressed.

[0059] Furthermore, the Martens hardness of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is, for example, 200 MPa or less, preferably 170 MPa or less, more preferably 150 MPa or less, even more preferably 140 MPa or less, and particularly preferably 100 MPa or less. If the Martens hardness of the optical functional layer 11 exceeds 200 MPa, cracks will occur in the optical functional layer 11 after transfer. Since the Martens hardness of the optical functional layer 11 according to this embodiment is 200 MPa or less, it is possible to avoid the situation in which cracks occur in the optical functional layer 11 after transfer.

[0060] In this embodiment, the Martens hardness of the optical functional layer 11 may be the Martens hardness measured by the measurement method specified in ISO 14577. In other words, the Martens hardness of the optical functional layer 11 obtained by the measurement method specified in ISO 14577 may be 3 MPa or more and 200 MPa or less.

[0061] (E) Thickness The thickness (Z direction) of the optical functional layer 11 according to this embodiment is, for example, 2 μm or more, preferably 4 μm or more, and more preferably 8 μm or more. If the thickness (layer thickness) of the optical functional layer 11 is less than 2 μm, defects will occur if foreign matter is mixed in during the transfer process. Also, if the thickness of the optical functional layer 11 is less than 2 μm, the anti-fogging function of the optical functional layer 11 will be reduced. Since the thickness of the optical functional layer 11 according to this embodiment is 2 μm or more, the occurrence of defects can be prevented even if foreign matter is mixed in during the transfer process. Also, since the thickness of the optical functional layer 11 according to this embodiment is 2 μm or more, the reduction in the anti-fogging function can be suppressed.

[0062] Furthermore, the thickness of the optical functional layer 11 according to this embodiment, obtained by the calculation method, is, for example, 20 μm or less, preferably 15 μm or less, and more preferably 10 μm or less. If the thickness of the optical functional layer 11 exceeds 20 μm, the curl of the optical functional layer 11 may increase or the optical functional layer 11 may crack due to shrinkage of the optical functional layer 11 during the curing process described later. Since the thickness of the optical functional layer 11 according to this embodiment is less than 20 μm, the curl of the optical functional layer 11 due to shrinkage can be reduced, and the situation in which the optical functional layer 11 cracks can be avoided.

[0063] [3. Composition of the uncured resin composition forming the optical functional layer] Next, the composition of the resin forming the optical functional layer 11 according to this embodiment will be described. Preferably, the resin forming the optical functional layer 11 according to this embodiment consists of a cured product of an uncured resin composition.

[0064] The uncured resin composition preferably contains silicone having acrylic functional groups. This allows the silicone having acrylic functional groups to segregate on the surface of the fine uneven structure 12 of the optical functional layer 11 during the transfer process. As a result, it is possible to improve the water contact angle of the surface of the fine uneven structure 12 of the optical functional layer 11. Furthermore, it is possible to improve the release properties of the optical functional layer 11 from the master disc during the transfer process.

[0065] Furthermore, the uncured resin composition may contain an acrylate monomer having one or both of ethylene oxide groups and acrylamide groups. This can improve the water absorption rate of the cured product of the uncured resin composition. In other words, by including an acrylate monomer having one or both of ethylene oxide groups and acrylamide groups in the uncured resin composition, the water absorption rate of the optical functional layer 11 can be improved.

[0066] Furthermore, the uncured resin composition may contain a polyfunctional acrylate monomer. This can improve the indentation modulus of the cured product of the uncured resin composition. In other words, by including a polyfunctional acrylate monomer in the uncured resin composition, the indentation modulus of the optical functional layer 11 can be improved.

[0067] [3.1. Acrylate monomers having an ethylene oxide group] The acrylate monomer having an ethylene oxide group is, for example, one or more selected from the group consisting of polyethylene glycol monoacrylate shown in formula (1) below, polyethylene glycol diacrylate shown in formula (2) below, trimethylolpropane EO-modified triacrylate shown in formula (3) below, pentaerythritol EO-modified tetraacrylate shown in formula (4) below, dipentaerythritol EO-modified polyacrylate shown in formula (5) below, and glycerin EO-modified triacrylate shown in formula (6) below, and preferably trimethylolpropane EO-modified triacrylate shown in formula (3) below. "EO" represents ethylene oxide. The acrylate monomer shown in formula (1) below can be obtained, for example, from NOF Corporation. The acrylate monomers shown in formulas (2) to (6) below can be obtained, for example, from Shin Nakamura Chemical Industry Co., Ltd.

[0068] [ka] /

[0069] [ka] /

[0070] In formulas (3), (4), and (6) above, R represents an ethylene oxide group. In formula (5) above, X represents an ethylene oxide group.

[0071] The repeating units of the ethylene oxide group in the acrylate monomer having an ethylene oxide group may be 4 or more and 20 or less. For example, one or more selected from the group consisting of a, b, c, d, e, f, n, m, l, and k in formulas (1) to (6) above may be 4 or more and 20 or less. If the repeating units of the ethylene oxide group in the acrylate monomer are less than 4, the water absorption rate of the optical functional layer 11 will decrease. On the other hand, if the repeating units of the ethylene oxide group in the acrylate monomer exceed 20, the indentation modulus of the optical functional layer 11 will decrease. By setting the repeating units of the ethylene oxide group in the acrylate monomer having an ethylene oxide group to 4 or more and 20 or less, it is possible to achieve both a high water absorption rate and a high indentation modulus in the optical functional layer 11.

[0072] Furthermore, the content of acrylate monomers having ethylene oxide groups in the uncured resin composition is, for example, 90% by mass or less, preferably 70% by mass or less, and more preferably 60% by mass or less. If the content of acrylate monomers having ethylene oxide groups in the uncured resin composition exceeds 90% by mass, the optical functional layer 11 itself will whiten when it absorbs water, and the transparency of the optical functional layer 11 will decrease. Therefore, by keeping the content of acrylate monomers having ethylene oxide groups in the uncured resin composition at 90% by mass or less, whitening of the optical functional layer 11 itself when it absorbs water can be prevented. Thus, a decrease in the transparency of the optical functional layer 11 can be prevented.

[0073] Furthermore, the content of acrylate monomers having ethylene oxide groups in the uncured resin composition is, for example, greater than 0% by mass, preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more. The higher the content of acrylate monomers having ethylene oxide groups in the uncured resin composition, the greater the water absorption rate of the optical functional layer 11, but the lower the indentation modulus. Therefore, by having a content of acrylate monomers having ethylene oxide groups in the uncured resin composition greater than 0% by mass, it is possible to achieve both a high water absorption rate and a high indentation modulus in the optical functional layer 11.

[0074] [3.2. Acrylate monomers having an acrylamide group] Acrylate monomers having an acrylamide group are, for example, monofunctional acrylamide monomers. Acrylate monomers having an acrylamide group are, for example, one or more selected from the group consisting of N,N-dimethylacrylamide shown in formula (7) below, N,N-diethylacrylamide shown in formula (8) below, acryloylmorpholine shown in formula (9) below, and N-(2-hydroxyethyl)acrylamide shown in formula (10) below, and preferably N,N-dimethylacrylamide shown in formula (7) below. Acrylate monomers shown in formulas (7) to (10) below can be obtained, for example, from KJ Chemicals Co., Ltd.

[0075] [ka] /

[0076] The content of acrylate monomers having acrylamide groups in the uncured resin composition is, for example, 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. If the content of acrylate monomers having acrylamide groups in the uncured resin composition exceeds 50% by mass, the crosslinking density of the cured product (resin after curing) decreases, and the scratch resistance and abrasion resistance of the fine uneven structure 12 of the optical functional layer 11 decreases. Therefore, by keeping the content of acrylate monomers having acrylamide groups in the uncured resin composition at 50% by mass or less, the scratch resistance and abrasion resistance of the optical functional layer 11 can be improved.

[0077] Furthermore, the content of acrylate monomers having acrylamide groups in the uncured resin composition is, for example, greater than 0% by mass, preferably 5% by mass or more, and more preferably 10% by mass or more. The higher the content of acrylate monomers having acrylamide groups in the uncured resin composition, the greater the water absorption rate of the optical functional layer 11. Therefore, by increasing the content of acrylate monomers having acrylamide groups in the uncured resin composition above 0% by mass, the water absorption rate of the optical functional layer 11 can be increased.

[0078] [3.3. Polyfunctional acrylate monomers] A polyfunctional acrylate monomer is, for example, one or more selected from the group consisting of difunctional acrylate monomers, trifunctional acrylate monomers, tetrafunctional acrylate monomers, pentafunctional acrylate monomers, and hexafunctional acrylate monomers. The polyfunctional acrylate monomer is, for example, one or more selected from the group consisting of trimethylolpropane triacrylate shown in formula (11) below, pentaerythritol triacrylate shown in formula (12) below, pentaerythritol tetraacrylate shown in formula (13) below, dipentaerythritol hexaacrylate shown in formula (14) below, tricyclodecanedimethanol diacrylate shown in formula (15) below, and hexanediol diacrylate shown in formula (16) below. Preferably, it is one or more selected from the group consisting of pentaerythritol triacrylate shown in formula (12) below, pentaerythritol tetraacrylate shown in formula (13) below, and tricyclodecanedimethanol diacrylate shown in formula (15) below. The acrylate monomers shown in formulas (11) to (16) below can be obtained, for example, from Shin Nakamura Chemical Industry Co., Ltd.

[0079] [ka] /

[0080] Furthermore, the content of polyfunctional acrylate monomers in the uncured resin composition is, for example, 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. If the content of polyfunctional acrylate monomers in the uncured resin composition is less than 10% by mass, the indentation modulus of the optical functional layer 11 will decrease. Therefore, by having a content of polyfunctional acrylate monomers of 10% by mass or more in the uncured resin composition, the indentation modulus of the optical functional layer 11 can be improved.

[0081] Furthermore, the content of polyfunctional acrylate monomers in the uncured resin composition is, for example, 60% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. If the content of polyfunctional acrylate monomers in the uncured resin composition exceeds 60% by mass, the water absorption rate of the optical functional layer 11 will decrease. Therefore, by keeping the content of polyfunctional acrylate monomers in the uncured resin composition at 60% by mass or less, a decrease in the water absorption rate of the optical functional layer 11 can be prevented.

[0082] [3.4. Silicone having acrylic functional groups] Silicones having acrylic functional groups include, for example, one or both of the following: acrylic group-containing polyester-modified polydimethylsiloxane and acrylic group-containing polyether-modified polydimethylsiloxane.

[0083] Furthermore, the content of silicone having acrylic functional groups in the uncured resin composition is, for example, 0.1% by mass or more, preferably 1% by mass or more, and more preferably 3% by mass or more, when the total of acrylate monomers having one or both of ethylene oxide groups and acrylamide groups, and polyfunctional acrylate monomers is taken as 100% by mass. If the content of silicone having acrylic functional groups in the uncured resin composition is less than 0.1% by mass, the release properties of the optical functional layer 11 from the master disc in the transfer process will decrease. Therefore, by having a content of silicone having acrylic functional groups in the uncured resin composition of 0.1% by mass or more, the release properties of the optical functional layer 11 from the master disc in the transfer process can be improved. Also, if the content of silicone having acrylic functional groups in the uncured resin composition is less than 0.1% by mass, the silicone having acrylic functional groups will hardly segregate on the surface of the fine uneven structure 12 of the optical functional layer 11 in the transfer process. Therefore, by ensuring that the content of silicone having acrylic functional groups in the uncured resin composition is 0.1% by mass or more, the silicone having acrylic functional groups can be efficiently segregated onto the surface of the fine uneven structure 12 of the optical functional layer 11 during the transfer process. This makes it possible to improve the water contact angle of the surface of the fine uneven structure 12 of the optical functional layer 11.

[0084] Furthermore, the content of silicone having acrylic functional groups in the uncured resin composition is, for example, 10% by mass or less, preferably 7% by mass or less, and more preferably 5% by mass or less, when the total of acrylate monomers having one or both of ethylene oxide groups and acrylamide groups, and polyfunctional acrylate monomers is taken as 100% by mass. If the content of silicone having acrylic functional groups in the uncured resin composition exceeds 10% by mass, the water absorption rate of the optical functional layer 11 will decrease. Therefore, by keeping the content of silicone having acrylic functional groups in the uncured resin composition at 10% by mass or less, a decrease in the water absorption rate of the optical functional layer 11 can be prevented.

[0085] [3.5. Other Ingredients] The uncured resin composition may further contain a photopolymerization initiator. The photopolymerization initiator is, for example, an α-hydroxyacetophenone-based photopolymerization initiator. As a photopolymerization initiator, for example, the product name "Omnirad 127" manufactured by IGM Resins BV can be used.

[0086] Furthermore, the uncured resin composition may contain other components (additives) to improve adhesion to the substrate 10, adjust the viscosity of the uncured resin composition, and so on. Examples of other components include antioxidants, phosphors, plasticizers, ultraviolet absorbers, defoamers, thixotropes, polymerization inhibitors, release agents, and metal oxide particles.

[0087] [4. Original Recording Composition] Next, with reference to Figure 3, the master disc 100 used to form the fine uneven structure 12 of the anti-reflective film 1 according to this embodiment will be described. Figure 3 is a schematic perspective view showing the master disc 100 according to this embodiment.

[0088] The master disc 100 is a mold for transferring a fine uneven structure 120 onto the surface of a transfer material (for example, the anti-reflective film 1 according to this embodiment) by a roll-to-roll imprinting method. From the viewpoint of efficiently producing the transfer material, the master disc 100 is preferably a roll-shaped master disc having a cylindrical or columnar shape, but it may also be a flat master disc. If the master disc 100 is a roll-shaped master disc, the fine uneven structure 120 of the master disc 100 can be seamlessly transferred to the substrate of the transfer material by the roll-to-roll method. This makes it possible to manufacture transfer materials with the fine uneven structure 120 of the master disc 100 transferred onto them with high production efficiency.

[0089] As shown in Figure 3, the master disc 100 comprises a roll-shaped base material 110 and a fine uneven structure 120 formed on the outer surface of the base material 110.

[0090] The base material 110 is, for example, a roll-shaped member that serves as the base material for a roll master. The shape of the base material 110 may be a hollow cylindrical shape as shown in Figure 3, or it may be a solid cylindrical shape without any internal cavities. The material of the base material 110 is not particularly limited, and quartz glass (SiO2) such as fused quartz glass or synthetic quartz glass, or metals such as stainless steel can be used. The size of the base material 110 is not particularly limited, but for example, the length in the direction of the central axis 110a of the base material 110 (hereinafter sometimes referred to as the axial direction) may be 100 mm or more, and the outer diameter of the base material 110 may be 50 mm or more and 300 mm or less. In addition, the radial thickness of a cylindrical base material 110 may be 2 mm or more and 50 mm or less.

[0091] The micro-textured structure 120 is a micro-textured pattern formed on the outer surface of the master disc 100. The micro-textured structure 120 comprises a plurality of micro-recesses 122 arranged at a predetermined pitch and a plurality of micro-protrusions 123 provided between two adjacent recesses 122. The micro-textured structure 120 of the master disc 100 has an inverted shape of the micro-textured structure of the transfer material (for example, the micro-textured structure 12 of the anti-reflective film 1). For example, the shape of the recesses 122 of the micro-textured structure 120 of the master disc 100 is an inverted shape of the protrusions 13 (see Figure 1) of the micro-textured structure 12 of the anti-reflective film 1. Similarly, the shape of the protrusions 123 of the micro-textured structure 120 of the master disc 100 is an inverted shape of the recesses 14 (see Figure 1) of the micro-textured structure 12 of the anti-reflective film 1. Furthermore, the pitch (circumferential dot pitch) of the recesses 122 of the micro-textured structure 120 of the master disc 100 is the same as the pitch of the protrusions 13 of the micro-textured structure 12 of the anti-reflective film 1.

[0092] Furthermore, in this embodiment, it is preferable that a release layer containing a fluoropolymer is formed on the surface of the fine uneven structure 120 of the master disc 100. For example, the release layer may be formed by applying a fluoropolymer coating agent to the surface of the fine uneven structure 120 of the master disc 100 and then performing a heat treatment. Examples of fluoropolymer coating agents that can be used include "Novec® 1720" manufactured by 3M Japan Ltd., "Optool DSX-F" manufactured by Daikin Industries, Ltd., "Fluorosurf® FG-5080" or "Fluorosurf® NL-1" manufactured by Fluorotechnology Ltd. The heat treatment is, for example, a process of heating at 100°C for 30 minutes.

[0093] By forming a release layer containing a fluoropolymer on the surface of the fine uneven structure 120 of the master disc 100, the surface energy of the fine uneven structure 120 of the master disc 100 can be lowered. This allows for suitable segregation of silicone having acrylic functional groups on the surface of the fine uneven structure 12 of the optical functional layer 11 during the transfer process.

[0094] A master disc 100 with such a configuration is provided in a roll-to-roll imprint transfer apparatus, for example, the transfer apparatus 300 shown in Figure 4. The master disc 100 can be used to manufacture a transfer product (for example, an anti-reflective film 1 according to this embodiment) on which the fine uneven structure 120 formed on the outer surface of the master disc 100 has been transferred. For example, the fine uneven structure 120 on the outer surface of the master disc 100 can be continuously transferred to the resin layer on the surface of the anti-reflective film 1, thereby forming the fine uneven structure 12 on the surface of the anti-reflective film 1 with high precision and efficiency.

[0095] [5. Method for manufacturing the transfer] Next, with reference to Figure 4, a method for efficiently manufacturing a transfer material such as an anti-reflective film 1 according to this embodiment using a transfer apparatus 300 equipped with a master disc 100 will be described. Figure 4 is a schematic diagram showing the configuration of a transfer apparatus 300 for manufacturing a transfer material using the master disc 100 according to this embodiment.

[0096] As shown in Figure 4, the transfer device 300 is a roll-to-roll type imprint transfer device. The transfer device 300 transfers the fine uneven structure 120 of the master disc 100 to the resin layer of the object to be transferred using a roll-to-roll method. This makes it possible to continuously manufacture transferred objects that have the fine uneven structure 120 formed on the outer surface of the master disc 100 transferred onto them.

[0097] As shown in Figure 4, the transfer apparatus 300 comprises a master disc 100, a substrate supply roll 301, a winding roll 302, guide rolls 303 and 304, a nip roll 305, a peeling roll 306, a coating device 307, and a light source 309.

[0098] The substrate supply roll 301 is, for example, a roll on which a film-like substrate 311 is wound. The winding roll 302 is a roll for winding the film-like substrate 331 which has a resin layer 312 onto which the fine uneven structure 120 has been transferred. Guide rolls 303 and 304 are rolls for conveying the film-like substrate 311 before and after the transfer. The nip roll 305 is a roll for pressing the film-like substrate 311 with the resin layer 312 laminated onto it against the master plate 100. The peeling roll 306 is a roll for peeling the film-like substrate 311, on which the fine uneven structure 120 has been transferred to the resin layer 312, from the master plate 100.

[0099] The film-like substrate 311 may be the same substrate as the substrate 10 of the anti-reflective film 1 according to the present embodiment (see Figure 1), or it may be a different substrate from the substrate 10. In the latter case, the anti-reflective film 1 may be manufactured by attaching the substrate 311 having a resin layer 312 onto which the fine uneven structure 120 has been transferred using the transfer apparatus 300 of Figure 4 to the surface of the substrate 10 of the anti-reflective film 1 (see Figure 1). For example, in this embodiment, the anti-reflective film 1 having the fine uneven structure 12 is constructed by attaching the film-like substrate 311 having the resin layer 312 onto which the fine uneven structure 120 has been transferred (see Figure 4) to the surface of the substrate 10 of the anti-reflective film 1 (see Figure 1).

[0100] The coating apparatus 307 includes a coating means such as a coater and coats the uncured photocurable resin composition onto the film-like substrate 311 to form a resin layer 312. The coating apparatus 307 may be, for example, a gravure coater, a wire bar coater, or a die coater. The light source 309 is a light source that emits light of a wavelength capable of curing the photocurable resin composition, and may be, for example, an ultraviolet lamp.

[0101] The uncured photocurable resin composition is the uncured resin composition described above, which hardens when irradiated with light of a predetermined wavelength.

[0102] Next, a method for producing a transfer product using the above-described transfer apparatus 300 will be explained.

[0103] First, a film-like substrate 311 is continuously fed from the substrate supply roll 301 and conveyed by the guide roll 303. Next, a photocurable resin composition is applied to the surface of the fed substrate 311 by the coating device 307, and an uncured resin layer 312 is laminated on the surface of the substrate 311.

[0104] Furthermore, the uncured resin layer 312 laminated on the surface of the substrate 311 is pressed against the outer surface of the master disc 100 by the nip roll 305. This transfers the fine uneven structure 120 formed on the outer surface of the master disc 100 to the uncured resin layer 312 (transfer step). At this time, the release layer formed on the surface of the fine uneven structure 120 of the master disc 100 causes silicone having acrylic functional groups to segregate onto the surface of the resin layer 312. Subsequently, the resin layer 312 to which the fine uneven structure 120 has been transferred is irradiated with light, such as ultraviolet light, from the light source 309 (curing step). This cures the uncured resin layer 312 and stabilizes the shape of the uneven pattern transferred to the cured resin layer 312. In addition, silicone having acrylic functional groups is segregated onto the surface of the cured resin layer 312 (fine uneven structure 12 of the optical functional layer 11).

[0105] Next, the substrate 311 on which the hardened resin layer 312 is laminated is peeled off from the outer surface of the master disc 100 by the peeling roll 306. As a result, a micro-textured structure 12 having the inverse shape of the micro-textured structure 120 of the master disc 100 is formed on the resin layer 312. After that, the substrate 311 peeled off from the master disc 100 is conveyed via the guide roll 304 and wound onto the winding roll 302.

[0106] In this way, using a roll-to-roll transfer apparatus 300, a transfer product (for example, the anti-reflective film 1 according to this embodiment) on which the fine uneven structure 120 formed on the master disc 100 has been transferred can be continuously manufactured. This makes it possible to manufacture a large quantity of transfer products on which the fine uneven structure 120 has been transferred with high precision, efficiently and at low cost.

[0107] [6. Examples of anti-reflective film applications] Next, we will describe an example of the application of the anti-reflective film 1 according to this embodiment.

[0108] As described above, the anti-reflective film 1 has excellent anti-reflective and anti-fogging properties. For this reason, the anti-reflective film 1 can be suitably applied to medical eye shields, medical face shields, industrial protective glasses, corrective glasses, sunglasses, swimming goggles, full-face helmets, smartphone cameras, camera cover glass for security cameras, displays such as in-car displays, vehicle windshields (e.g., the front of in-car cameras), in-car head-up displays, dust covers, refrigerator glass doors, VR goggle displays, VR goggle optics, VR goggle covers, and the surface of solar cells.

[0109] [7. Summary] The anti-reflective film 1 according to this embodiment has been described above.According to this embodiment, an anti-reflective film 1 is provided which comprises an optical functional layer 11 made of resin, the optical functional layer 11 has a fine uneven structure 12 including protrusions 13 or recesses 14 arranged at a pitch of less than or equal to the wavelength of visible light, the indentation modulus of the optical functional layer 11 is 45 MPa or more, the water absorption rate of the optical functional layer 11 is 11 mass% or more, and the water contact angle of the surface of the optical functional layer 11 is 65° or more.As a result, the anti-reflective film 1 according to this embodiment can suppress deformation of the fine uneven structure 12 due to water absorption and achieve both anti-fogging and anti-reflective functions.Therefore, the anti-reflective film 1 according to this embodiment can have anti-reflective function, high transparency, and anti-fogging function.

[0110] Furthermore, in this embodiment, the resin forming the optical functional layer 11 may consist of a cured product of an uncured resin composition, and the uncured resin composition may contain silicone having acrylic functional groups. This allows the silicone having acrylic functional groups to be segregated on the surface of the fine uneven structure 12 of the optical functional layer 11 during the transfer process. As a result, the anti-reflective film 1 according to this embodiment can improve the water contact angle of the surface of the fine uneven structure 12 of the optical functional layer 11.

[0111] Furthermore, in this embodiment, the Martens hardness of the optical functional layer 11 is preferably 3 MPa or higher. This allows the anti-reflective film 1 according to this embodiment to further suppress deformation of the fine uneven structure 12 due to water absorption.

[0112] Furthermore, in this embodiment, the resin forming the optical functional layer 11 may consist of a cured product of an uncured resin composition, and the uncured resin composition may contain an acrylate monomer having one or both of an ethylene oxide group and an acrylamide group. This allows the anti-reflective film 1 according to this embodiment to further improve the water absorption rate of the optical functional layer 11. Therefore, the anti-reflective film 1 according to this embodiment can exhibit a high anti-fogging function.

[0113] Furthermore, in this embodiment, the number of repeating units of the ethylene oxide group in the acrylate monomer having the ethylene oxide group may be 4 or more and 20 or less. As a result, the anti-reflective film 1 according to this embodiment can achieve both a high water absorption rate and a high indentation modulus in the optical functional layer 11. Therefore, the anti-reflective film 1 according to this embodiment can exhibit high anti-fogging function and high anti-reflective function.

[0114] Furthermore, in this embodiment, the content of acrylate monomers having ethylene oxide groups in the uncured resin composition may be 90% by mass or less. This prevents the anti-reflective film 1 according to this embodiment from whitening of the optical functional layer 11 itself when it absorbs water. Therefore, it is possible to prevent a decrease in the transparency of the optical functional layer 11.

[0115] Furthermore, in this embodiment, the content of acrylate monomers having acrylamide groups in the uncured resin composition may be 50% by mass or less. This allows the anti-reflective film 1 according to this embodiment to improve the scratch resistance and abrasion resistance of the optical functional layer 11.

[0116] Furthermore, in this embodiment, the resin forming the optical functional layer 11 may consist of a cured product of an uncured resin composition, and the uncured resin composition may contain a polyfunctional acrylate monomer. This allows the anti-reflective film 1 according to this embodiment to further improve the indentation modulus of the optical functional layer 11. Therefore, the anti-reflective film 1 according to this embodiment can further suppress deformation of the fine uneven structure 12 due to water absorption.

[0117] Furthermore, in this embodiment, the content of polyfunctional acrylate monomer in the uncured resin composition may be 10% by mass or more. This allows the anti-reflective film 1 according to this embodiment to further improve the indentation modulus of the optical functional layer 11.

[0118] Furthermore, in this embodiment, a base material 10 may be provided, and the optical functional layer 11 may be provided on the base material 10. This improves the ease of handling of the anti-reflective film 1 according to this embodiment.

[0119] Furthermore, in this embodiment, the optical functional layer 11 may also have an anti-fogging function. As a result, the anti-reflective film 1 according to this embodiment can be suitably applied to medical eye shields, industrial safety glasses, camera cover glass, and the like.

[0120] Furthermore, according to this embodiment, an eye shield equipped with an anti-reflective film 1 is provided. This makes it possible to provide an eye shield that has both anti-reflective and anti-fog functions. [Examples]

[0121] Next, an anti-reflective film according to an embodiment of the present invention will be described. It should be noted that the following embodiments are merely examples to demonstrate the effects and feasibility of the anti-reflective film according to the present invention, and the present invention is not limited to these embodiments.

[0122] Anti-reflective films 1 of Examples 1-3 and anti-reflective films of Comparative Examples 1-4 were prepared. The anti-reflective films 1 of Examples 1-3 and the anti-reflective films of Comparative Examples 1-2 differed in the number of times the master disc 100 was used, but the substrate 10, the composition of the uncured resin composition, the content of each composition in the uncured resin composition, the thickness of the optical functional layer 11, and the manufacturing method were the same. Comparative Examples 3-4 differed from Comparative Example 1 in the composition of the uncured resin composition and the content of each composition in the uncured resin composition, but the substrate 10, the thickness of the optical functional layer, the manufacturing method, and the number of times the master disc 100 was used were the same.

[0123] Polyethylene terephthalate (PET) was used as the substrate 10 for the anti-reflective films 1 in Examples 1-3 and the anti-reflective films in Comparative Examples 1-4. The thickness of the substrate 10 was 100 μm. The substrate 10 used was product name "A4360" manufactured by Toyobo Co., Ltd.

[0124] Then, a resin layer was formed by applying the uncured resin composition to the substrate 10, transferring the fine uneven structure of the flat master plate 100 to the resin layer, and curing the resin layer by irradiating it with ultraviolet light from the substrate 10 side. At this time, a metal halide lamp was used for ultraviolet irradiation, and the integrated light intensity was 200 mJ / m 2 The following was done. The pitch of the fine uneven structure of the master disc 100 was set to 200 nm, and the height of the protrusions was set to 250 nm. The arrangement of the multiple protrusions of the fine uneven structure of the master disc 100 was set to a quasi-hexagonal lattice arrangement. In addition, a release layer containing a fluoropolymer was pre-formed on the surface of the fine uneven structure 120 of the master disc 100. The release layer was formed by applying "Novec(registered trademark) 1720," a product manufactured by 3M Japan Ltd., to the surface of the fine uneven structure 120 of the master disc 100. In other words, the fine uneven structure was transferred to the resin layer using the master disc 100, which had a release layer formed on the surface of the fine uneven structure 120.

[0125] After the fine uneven structure was transferred and the hardened resin layer was released from the master disc, ultraviolet light was further irradiated from the side of the fine uneven structure 12 of the optical functional layer 11. A metal halide lamp was used for this ultraviolet irradiation, with an integrated light intensity of 500 mJ / m². 2 The thickness of the optical functional layer 11 was set to 10 μm. In this way, the anti-reflective films 1 of Examples 1 to 3 and the anti-reflective films of Comparative Examples 1 to 4 were prepared.

[0126] The following describes the composition of the uncured resin composition used to create the anti-reflective films 1 of Examples 1 to 3 and the anti-reflective films of Comparative Examples 1 to 4.

[0127] Furthermore, as the acrylate monomer having an ethylene oxide group, the trimethylolpropane EO-modified triacrylate shown in formula (3) above was used. As the trimethylolpropane EO-modified triacrylate, the product name "NK Ester AT-20E" manufactured by Shin Nakamura Chemical Industry Co., Ltd. was used.

[0128] As the acrylate monomer having an acrylamide group, N,N-dimethylacrylamide represented by formula (7) above was used. As the N,N-dimethylacrylamide, the product name "DMMA" manufactured by KJ Chemicals Co., Ltd. was used.

[0129] As the polyfunctional acrylate monomer, we used tricyclodecanedimethanol diacrylate shown in formula (15) above, or pentaerythritol triacrylate shown in formula (12) above and pentaerythritol tetraacrylate shown in formula (13) above. For tricyclodecanedimethanol diacrylate, we used the product name "NK Ester A-DCP" manufactured by Shin Nakamura Chemical Industry Co., Ltd. For pentaerythritol triacrylate and pentaerythritol tetraacrylate, we used the product name "NK Ester A-TMM-3L" manufactured by Shin Nakamura Chemical Industry Co., Ltd.

[0130] As another monomer, 2-hydroxy-3-phenoxypropyl acrylate was used. The 2-hydroxy-3-phenoxypropyl acrylate used was "Arronix M5700," a product manufactured by Toagosei Co., Ltd.

[0131] As the silicone having acrylic functional groups, an acrylic group-containing polyester-modified polydimethylsiloxane was used. The acrylic group-containing polyester-modified polydimethylsiloxane used was "BYK-UV3570," a product manufactured by BYK.

[0132] As a photopolymerization initiator, we used "Omnirad 127," a product manufactured by IGM Resins BV.

[0133] [Example 1] The uncured resin composition of Example 1 was prepared to contain trimethylolpropane EO-modified triacrylate, N,N-dimethylacrylamide, tricyclodecanedimethanol diacrylate, acrylic group-containing polyester-modified polydimethylsiloxane, and further to include 2-hydroxy-3-phenoxypropyl acrylate and a photopolymerization initiator.

[0134] The content of trimethylolpropane EO-modified triacrylate in the uncured resin composition was 56% by mass. The content of N,N-dimethylacrylamide in the uncured resin composition was 12% by mass. The content of tricyclodecanedimethanol diacrylate in the uncured resin composition was 10% by mass. The content of 2-hydroxy-3-phenoxypropyl acrylate in the uncured resin composition was 22% by mass. Furthermore, when the total of trimethylolpropane EO-modified triacrylate, N,N-dimethylacrylamide, tricyclodecanedimethanol diacrylate, and 2-hydroxy-3-phenoxypropyl acrylate is set to 100% by mass, the content of acrylic group-containing polyester-modified polydimethylsiloxane in the uncured resin composition was set to 1% by mass, and the content of the photopolymerization initiator in the uncured resin composition was set to 3% by mass.

[0135] In Example 1, a release layer was formed on the surface of the master disc 100, and then the optical functional layer 11 was created by performing the first transfer using the master disc 100 (first transfer).

[0136] [Example 2] The uncured resin composition of Example 2, and the content of each component in the uncured resin composition, are the same as in Example 1.

[0137] In Example 2, a release layer was formed on the surface of the master disc 100, and then the master disc 100 was used to perform a transfer for the 50th time (50th transfer), thereby creating the optical functional layer 11.

[0138] [Example 3] The uncured resin composition of Example 3, and the content of each component in the uncured resin composition, are the same as in Example 1.

[0139] In Example 3, a release layer was formed on the surface of the master disc 100, and then the master disc 100 was used to perform a transfer 100 times (100th transfer) to create the optical functional layer 11.

[0140] [Comparative Example 1] The uncured resin composition of Comparative Example 1, and the content of each component in the uncured resin composition, are the same as in Example 1.

[0141] In Comparative Example 1, a release layer was formed on the surface of the master disc 100, and then the master disc 100 was used for the 150th transfer (150th transfer) to create the optical functional layer 11.

[0142] [Comparative Example 2] The uncured resin composition of Comparative Example 2, and the content of each component in the uncured resin composition, are the same as in Example 1.

[0143] In Comparative Example 2, a release layer was formed on the surface of the master disc 100, and then the master disc 100 was used to perform a transfer for the 200th time (200th transfer), thereby creating the optical functional layer 11.

[0144] [Comparative Example 3] The uncured resin composition of Comparative Example 3 was prepared to contain trimethylolpropane EO-modified triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and a photopolymerization initiator. Furthermore, the uncured resin composition of Comparative Example 3 did not contain acrylate monomers having acrylamide groups or silicones having acrylic functional groups.

[0145] The content of trimethylolpropane EO-modified triacrylate in the uncured resin composition was set to 90% by mass. The content of pentaerythritol triacrylate and pentaerythritol tetraacrylate in the uncured resin composition was set to 10% by mass. Furthermore, the content of the photopolymerization initiator in the uncured resin composition was set to 3% by mass, assuming that the total of trimethylolpropane EO-modified triacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate was 100% by mass.

[0146] In Comparative Example 3, a release layer was formed on the surface of the master disc 100, and then the optical functional layer 11 was created by performing the first transfer using the master disc 100 (first transfer).

[0147] [Comparative Example 4] The uncured resin composition of Comparative Example 4 was prepared to contain trimethylolpropane EO-modified triacrylate, 2-hydroxy-3-phenoxypropyl acrylate, and a photopolymerization initiator. Furthermore, the uncured resin composition of Comparative Example 4 did not contain acrylate monomers having acrylamide groups, polyfunctional acrylate monomers, or silicones having acrylic functional groups.

[0148] The content of trimethylolpropane EO-modified triacrylate in the uncured resin composition was set to 60% by mass. The content of 2-hydroxy-3-phenoxypropyl acrylate in the uncured resin composition was set to 40% by mass. Furthermore, the content of the photopolymerization initiator in the uncured resin composition was set to 3% by mass, assuming that the total of trimethylolpropane EO-modified triacrylate and 2-hydroxy-3-phenoxypropyl acrylate was 100% by mass.

[0149] In Comparative Example 4, a release layer was formed on the surface of the master disc 100, and then the optical functional layer 11 was created by performing the first transfer using the master disc 100 (first transfer).

[0150] [Water contact angle] Table 1 shows the results of water contact angle, anti-fogging performance evaluation, and whitening evaluation for anti-reflective film 1 of Examples 1 to 3. Table 2 shows the results of water contact angle, anti-fogging performance evaluation, and whitening evaluation for anti-reflective films of Comparative Examples 1 to 4. In Tables 1 and 2, "A" indicates no fogging or no water film formation, and "C" indicates fogging or the spread of a water film.

[0151] [Table 1]

[0152] [Table 2]

[0153] The water contact angles of the surface of the micro-textured structure 12 of the anti-reflective film 1 in Examples 1 to 3, and the surface of the micro-textured structure 12 of the anti-reflective film in Comparative Examples 1 to 4 were measured. The water contact angles were measured using a contact angle meter by the droplet method under the following conditions. Amount of water added: 1.0 μL Measurement temperature: 25℃ Based on measurements taken 10 seconds after dropping water onto the surface of the optical functional layer 11 of the anti-reflective film 1 of Examples 1 to 3 and the anti-reflective film of Comparative Examples 1 to 4, the water contact angle of the surface of the optical functional layer 11 was calculated using the θ / 2 method.

[0154] For the contact angle meter, we used the "Contact Angle Meter DMe-700" manufactured by Kyowa Interface Chemical Co., Ltd.

[0155] As shown in Table 1, the water contact angle of Example 1 was 128°. The water contact angle of Example 2 was 90°. The water contact angle of Example 2 was 68°. Also, as shown in Table 2, the water contact angle of Comparative Example 1 was 51°. The water contact angle of Comparative Example 2 was 44°. From these results, it was confirmed that the water contact angle of the surface of the optical functional layer 11 decreased as the number of transfer cycles increased. Furthermore, Comparative Examples 1 and 2 had a larger number of transfer cycles compared to Examples 1 to 3. For this reason, it is presumed that in Comparative Examples 1 and 2, fluorine was detached from the release layer formed on the surface of the fine uneven structure 120 of the master disc 100, increasing the surface energy of the release layer, and thus preventing the silicone having acrylic functional groups from segregating on the surface of the fine uneven structure 12 of the optical functional layer 11 during the transfer process.

[0156] Furthermore, as shown in Table 2, the water contact angle of Comparative Example 3 was 30°. The water contact angle of Comparative Example 4 was 35°. From these results, it was confirmed that when the uncured resin composition does not contain silicone having acrylic functional groups, the water contact angle of the surface of the optical functional layer 11 is low. It is presumed that when the uncured resin composition does not contain silicone having acrylic functional groups, the silicone having acrylic functional groups is not segregated on the surface of the fine uneven structure 12 of the optical functional layer during the transfer process, resulting in a lower water contact angle of the surface of the fine uneven structure 12 of the optical functional layer 11.

[0157] [Anti-fogging performance evaluation] The anti-fogging properties of the anti-reflective films 1 of Examples 1-3 and the anti-reflective films of Comparative Examples 1-4 were evaluated. For the anti-fogging evaluation, the surface condition of the anti-reflective films 1 of Examples 1-3 and the anti-reflective films of Comparative Examples 1-4 was visually checked by blowing exhaled air from a distance of 1 cm from the mouth.

[0158] As shown in Table 1, Example 1 received an evaluation of "A". Example 2 also received an evaluation of "A". Example 3 also received an evaluation of "A". Furthermore, as shown in Table 2, Comparative Example 1 also received an evaluation of "A". Comparative Example 2 also received an evaluation of "A".

[0159] As shown in Table 2, Comparative Example 3 received an evaluation of "A". Comparative Example 4 received an evaluation of "C". Comparative Example 4 had a lower water absorption rate compared to Example 1. Therefore, it is presumed that Comparative Example 4 had lower anti-fogging properties than Example 1.

[0160] [Whitening evaluation] The anti-reflective films 1 of Examples 1-3 and the anti-reflective films of Comparative Examples 1-4 were evaluated for whitening. For the whitening evaluation, the surface condition was visually checked after the anti-fogging evaluation described above. In Tables 1 and 2, "A" indicates no whitening, i.e., the film remains transparent, and "C" indicates whitening.

[0161] As shown in Table 1, all of Examples 1 to 3 received an evaluation of "A". On the other hand, as shown in Table 2, all of Comparative Examples 1 to 5 received an evaluation of "C". Comparative Examples 1 and 2 had more transfer cycles compared to Examples 1 to 3. Therefore, it is presumed that in Comparative Examples 1 and 2, fluorine was detached from the release layer formed on the surface of the fine uneven structure 120 of the master disc 100, increasing the surface energy of the release layer, and thus preventing the silicone having acrylic functional groups from segregating on the surface of the fine uneven structure 12 of the optical functional layer 11 during the transfer process.

[0162] Furthermore, unlike Example 1, Comparative Example 3 does not contain silicone having acrylic functional groups in the uncured resin composition. Therefore, unlike Example 1, it is presumed that in Comparative Example 3, the silicone having acrylic functional groups was not segregated on the surface of the fine uneven structure 12 of the optical functional layer 11 during the transfer process, resulting in extremely low whitening resistance.

[0163] Furthermore, Comparative Example 4 has a lower indentation modulus compared to Example 1. Therefore, it is presumed that Comparative Example 4, unlike Example 1, has extremely low whitening resistance.

[0164] [Indentation modulus]

[0165] Samples for Examples 1A to 3A and Comparative Examples 1A to 4A were prepared. The samples for Examples 1A to 3A and Comparative Examples 1A to 4A differed in the composition of the uncured resin composition and the content of each component in the uncured resin composition, but the manufacturing method was the same.

[0166] A 100 μm spacer was inserted between two soda-lime glass plates, and the uncured resin composition was filled in. The resin composition was then cured by irradiation with ultraviolet light. A metal halide lamp was used for the ultraviolet irradiation, with an integrated light intensity of 2000 mJ / m². 2 This was done. In this way, samples for Examples 1A to 3A and comparative examples 1A to 4A were prepared.

[0167] The uncured resin composition of Example 1A was the same as that of Example 1. The uncured resin composition of Example 2A was the same as that of Example 2. The uncured resin composition of Example 3A was the same as that of Example 3. Furthermore, the uncured resin composition of Comparative Example 1A was the same as that of Comparative Example 1. The uncured resin composition of Comparative Example 2A was the same as that of Comparative Example 2. The uncured resin composition of Comparative Example 3A was the same as that of Comparative Example 3. The uncured resin composition of Comparative Example 4A was the same as that of Comparative Example 4.

[0168] Table 3 shows the indentation modulus and Martens hardness of the samples from Examples 1A to 3A. Table 4 shows the indentation modulus and Martens hardness of the samples from Comparative Examples 1A to 4A.

[0169] [Table 3]

[0170] [Table 4]

[0171] The indentation modulus of anti-reflective film 1 of Examples 1A to 3A and the anti-reflective film of Comparative Examples 1A to 4A were calculated.

[0172] The indentation modulus was calculated using the Oliver & Pharr method based on the unloading curve obtained by pressing a Vickers indenter against the surface of a sample using an indentation tester, fitted within a range of 40% to 98% of the maximum load. The indentation modulus was also calculated based on the unloading curve obtained under the conditions of a load of 0.5 mN / 10 seconds, holding time of 10 seconds, and unloading of 0.5 mN / 10 seconds. Anton Paar's nanoindentation tester, product name "Hit 300," was used as the indentation tester.

[0173] As shown in Table 3, the indentation modulus of Example 1A was 45 MPa. The indentation modulus of Example 2A was 45 MPa. The indentation modulus of Example 3A was 45 MPa. Also, as shown in Table 4, the indentation modulus of Comparative Example 1A was 45 MPa. The indentation modulus of Comparative Example 2A was 45 MPa.

[0174] As shown in Table 4, the indentation modulus of Comparative Example 3A was 126 MPa. The indentation modulus of Comparative Example 4A was 37 MPa.

[0175] Comparative Example 4A does not contain polyfunctional acrylate monomers in its uncured resin composition compared to Example 1A. Therefore, it is presumed that the indentation modulus of Comparative Example 4A is lower than that of Example 1A.

[0176] [Martens hardness] The Martens hardness of anti-reflective film 1 from Examples 1A to 3A and the anti-reflective films from Comparative Examples 1A to 4A were calculated.

[0177] The Martens hardness was calculated by dividing the test load applied when a Vickers indenter was pressed against the surface of the sample using an indentation tester by the surface area into which the Vickers indenter penetrated the sample. The Martens hardness was also calculated under the conditions of a load of 0.5 mN / 10 seconds, a holding time of 10 seconds, and an unloading time of 0.5 mN / 10 seconds. Anton Paar's nanoindentation tester, product name "Hit 300," was used as the indentation tester.

[0178] As shown in Table 3, the Martens hardness of Example 1A was 3 MPa. The Martens hardness of Example 2A was 3 MPa. The Martens hardness of Example 3A was 3 MPa. Also, as shown in Table 4, the Martens hardness of Comparative Example 1A was 3 MPa. The Martens hardness of Comparative Example 2A was 3 MPa.

[0179] As shown in Table 4, the Martens hardness of Comparative Example 3A was 9.5 MPa. The Martens hardness of Comparative Example 4A was 3 MPa.

[0180] [Water absorption rate] Samples for Examples 1B-3B and Comparative Examples 1B-4B were prepared. The samples for Examples 1B-3B and Comparative Examples 1B-4B differed in the composition of the uncured resin composition and the content of each component in the uncured resin composition, but the manufacturing method was the same.

[0181] A 500 μm spacer was inserted between the soda-lime glass and the silicone rubber, and the uncured resin composition was filled in. The resin composition was then cured by irradiation with ultraviolet light. A metal halide lamp was used for the ultraviolet irradiation, with an integrated light intensity of 2000 mJ / m². 2 The cured material was then cut into 50mm x 70mm sheets to create samples for Examples 1B to 3B and Comparative Examples 1B to 4B.

[0182] The uncured resin composition of Example 1B was the same as that of Example 1. The uncured resin composition of Example 2B was the same as that of Example 2. The uncured resin composition of Example 3B was the same as that of Example 3. Furthermore, the uncured resin composition of Comparative Example 1B was the same as that of Comparative Example 1. The uncured resin composition of Comparative Example 2B was the same as that of Comparative Example 2. The uncured resin composition of Comparative Example 3B was the same as that of Comparative Example 3. The uncured resin composition of Comparative Example 4B was the same as that of Comparative Example 4.

[0183] Table 5 shows the water absorption rates of the samples from Examples 1B to 3B and Comparative Examples 1B to 4B.

[0184] [Table 5]

[0185] The water absorption rates of the samples from Examples 1B to 3B and Comparative Examples 1B to 4B were calculated using the procedure shown in Figure 2 above.

[0186] As shown in Table 5, the water absorption rate of Example 1B was 19.4%. The water absorption rate of Example 2B was 19.4%. The water absorption rate of Example 3B was 19.4%. Also, as shown in Table 5, the water absorption rate of Comparative Example 1B was 19.4%. The water absorption rate of Comparative Example 2B was 19.4%.

[0187] As shown in Table 5, the water absorption rate of Comparative Example 3B was 23.7%. The water absorption rate of Comparative Example 4B was 10.5%. Comparative Example 3B has a higher content of acrylate monomers having ethylene oxide groups in the uncured resin composition compared to Example 1B. Therefore, it is presumed that the water absorption rate of Comparative Example 3B was higher than that of Example 1B.

[0188] Although preferred embodiments of the present invention have been described in detail above with reference to the attached drawings, the present invention is not limited to these examples. It is clear to any person with ordinary skill in the art to which the present invention belongs that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these are also understood to fall within the technical scope of the present invention. [Explanation of symbols]

[0189] 1. Anti-reflective film 10 Base material 100 original recordings 11 Optical functional layer 12 Fine uneven structure 13 Convex part 14 recess

Claims

1. It has an optical functional layer made of resin, The optical functional layer has a fine uneven structure including protrusions or recesses arranged at a pitch less than or equal to the wavelength of visible light. The indentation modulus of the optical functional layer is 45 MPa or more. The water absorption rate of the optical functional layer is 11% by mass or more. An anti-reflective film in which the water contact angle of the surface of the optical functional layer is 65° or more.

2. The resin forming the optical functional layer consists of a cured product of an uncured resin composition. The anti-reflective film according to claim 1, wherein the uncured resin composition comprises a silicone having an acrylic functional group.

3. The anti-reflective film according to claim 1 or 2, wherein the Martens hardness of the optical functional layer is 3 MPa or more.

4. The resin forming the optical functional layer consists of a cured product of an uncured resin composition. The anti-reflective film according to claim 1 or 2, wherein the uncured resin composition comprises an acrylate monomer having one or both of an ethylene oxide group and an acrylamide group.

5. The anti-reflective film according to claim 4, wherein the repeating units of the ethylene oxide group in the acrylate monomer having the ethylene oxide group are 4 or more and 20 or less.

6. The anti-reflective film according to claim 4, wherein the content of the acrylate monomer having an ethylene oxide group in the uncured resin composition is 90% by mass or less.

7. The anti-reflective film according to claim 4, wherein the content of acrylate monomers having acrylamide groups in the uncured resin composition is 50% by mass or less.

8. The resin forming the optical functional layer consists of a cured product of an uncured resin composition. The anti-reflective film according to claim 1 or 2, wherein the uncured resin composition comprises a polyfunctional acrylate monomer.

9. The anti-reflective film according to claim 8, wherein the content of polyfunctional acrylate monomer in the uncured resin composition is 10% by mass or more.

10. Further equipped with a base material, The optical functional layer is provided on the substrate, and is an anti-reflective film according to claim 1 or 2.

11. The optical functional layer is an anti-fogging film according to claim 1 or 2.

12. An eye shield comprising the anti-reflective film described in claim 1 or 2.

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