Anti-reflective film and resin molded article using same

Abstract

Through the present invention, it is possible to provide an anti-reflective film having a substrate layer including a thermoplastic resin, a hard coat layer that is a hardened coating film layer on at least one surface of the substrate layer, and a low-refractive-index layer having a refractive index at least 0.05 lower than the refractive index of the hard coat layer in the stated order, wherein the low-refractive-index layer has a thickness of 70-130 nm and contains a fluorine-containing leveling agent and a silicon-containing slipping agent, the surface roughness of the surface of the low-refractive-index layer is 5.0 nm or less, the intensity ratio I(Si) / I(F) of silicon and fluorine in the surface of the low-refractive-index layer is 0.8 to 3.2, and the luminous reflectance of the anti-reflective film is 3.0% or less.

Description

Anti-reflection film and resin molded product using the same

[0001] The present invention relates to an antireflection film including a substrate layer, a hard coat layer, and a low refractive index layer, and to a resin molded article using the antireflection film.

[0002] Conventionally, laminate films having a surface with low reflectance and usable as antireflection films have been known (see Patent Document 1). Laminate films with low surface reflectance are used in applications such as computer screens, television screens, plasma display panels, the surfaces of polarizing plates used in liquid crystal display devices, sunglasses lenses, prescription eyeglass lenses, camera viewfinder lenses, various instrument covers, automobile glass, train glass, in-vehicle display panels, and electronic device housings. Under these circumstances, there has been a demand for antireflection films with low luminous reflectance and excellent resistance to cloth abrasion and fingerprint wiping for the above-mentioned applications.

[0003] JP 2014-41244 A

[0004] An object of the present invention is to provide an anti-reflection film that has low luminous reflectance, and is excellent in resistance to scratches by cloth and ease of wiping off fingerprints.

[0005] As a result of extensive research aimed at solving the above-mentioned problems, the present inventors have discovered that by incorporating a specific combination of additives into a low refractive index layer having a specific film thickness, it is possible to provide an antireflection film that has low luminous reflectance and excellent resistance to cloth abrasion and ease of fingerprint wiping, and have thus completed the present invention.

[0006] That is, the present invention is as follows. <1> An antireflection film having, in this order, a substrate layer containing a thermoplastic resin, and, on at least one surface of the substrate layer, a hard coat layer which is a cured coating layer, and a low refractive index layer having a refractive index 0.05 or more lower than that of the hard coat layer, wherein the low refractive index layer has a thickness of 70 to 130 nm and contains a fluorine-containing leveling agent and a silicon-containing slip agent, the surface roughness of the low refractive index layer is 5.0 nm or less as measured with an atomic force microscope, the intensity ratio I(Si) / I(F) of silicon to fluorine on the surface of the low refractive index layer is 0.8 or more and 3.2 or less as measured with a glow discharge optical emission spectrometer, and the luminous reflectance of the antireflection film is 3.0% or less. <2> An antireflection film according to the above <1>, wherein the luminous reflectance of the antireflection film is 1.6 to 2.8%. <3> The antireflection film according to <1> or <2> above, wherein the low refractive index layer contains hollow silica. <4> The antireflection film according to <3> above, wherein the mass ratio of hollow silica to resin material contained in the low refractive index layer is 20:80 to 60:40. <5> The antireflection film according to any one of <1> to <4> above, wherein the silicon-containing slip agent is a polydimethylsiloxane-containing slip agent. <6> The antireflection film according to any one of <1> to <5> above, wherein the mass ratio of silicon-containing slip agent to fluorine-containing leveling agent contained in the low refractive index layer is 9:1 to 5:5. <7> The antireflection film according to any one of <1> to <6> above, wherein the contact angle of oleic acid on the surface of the low refractive index layer is 55° or more. <8> The antireflection film according to any one of <1> to <7> above, which is used for insert molding. <9> A resin molded product having the antireflection film according to any one of <1> to <8> above on a surface thereof.

[0007] According to the present invention, an antireflection film having low luminous reflectance and excellent resistance to abrasion by cloth and ease of wiping off fingerprints can be provided. Because of these excellent characteristics, the antireflection film of the present invention can be suitably used in applications such as display parts of computers, televisions, plasma displays, etc., surfaces of polarizing plates used in liquid crystal display devices, sunglasses lenses, prescription eyeglass lenses, camera viewfinder lenses, in-vehicle display panels, and housings for electronic devices.

[0008] 1 is a schematic diagram showing the laminate structure of the antireflection film obtained in Example 1. FIG. 2 is a photograph showing the surface roughness Ra (nm) of the low refractive index layer surface measured by atomic force microscope (AFM).

[0009] The present invention will be described in detail below. Note that the present invention is not limited to the following embodiments, and can be implemented by making any modifications within the scope of the effects of the invention.

[0010] [Anti-Reflection Film] One embodiment of the present invention is an anti-reflection film comprising a substrate layer containing a thermoplastic resin, and, on at least one side of the substrate layer, a hard coat layer (cured coating layer) and a low-refractive index layer having a refractive index at least 0.05 lower than that of the hard coat layer, in this order. The low-refractive index layer has a thickness of 70 to 130 nm and contains a fluorine-containing leveling agent and a silicon-containing slip agent. The surface roughness of the low-refractive index layer measured with an atomic force microscope is 5.0 nm or less, the intensity ratio I(Si) / I(F) of silicon to fluorine at the surface of the low-refractive index layer is 0.8 or more and 3.2 or less, measured with a glow discharge optical emission spectrometer, and the luminous reflectance of the anti-reflection film is 3.0% or less. Each layered component included in this laminated anti-reflection film is described below.

[0011] [Low Refractive Index Layer (Anti-Reflection Layer)] The low refractive index layer in the present invention has a refractive index that is 0.05 or more lower than the refractive index of the hard coat layer, preferably 0.07 or more lower, and more preferably 0.08 to 0.12 lower. A refractive index that is 0.05 or more lower than the refractive index of the hard coat layer is preferable because sufficient anti-reflection performance can be obtained. The refractive index of the low refractive index layer is preferably in the range of 1.35 to 1.44, more preferably 1.38 to 1.42, and particularly preferably 1.39 to 1.41. If the refractive index is less than 1.35, it may be difficult to obtain sufficient hardness, while if the refractive index exceeds 1.44, it may be difficult to obtain sufficient anti-reflection performance.

[0012] The film thickness of the low refractive index layer is 70 to 130 nm, preferably 80 to 120 nm, and more preferably 90 to 110 nm. If the film thickness of the low refractive index layer is less than 70 nm, the wavelength range of light for which reflection can be prevented is significantly shifted to the low wavelength side, resulting in a deterioration in luminous reflectance. If the film thickness exceeds 130 nm, the wavelength range of light for which reflection can be prevented is significantly shifted to the high wavelength side, resulting in a deterioration in luminous reflectance. The low refractive index layer is preferably disposed on the outermost side of the antireflection film in order to suppress reflection from the antireflection film.

[0013] The low refractive index layer is formed by applying a coating liquid of a composition for forming a low refractive index layer onto the hard coat layer and then curing it by ultraviolet irradiation. The coating method, curing conditions, and dilution solvent for adjusting viscosity are not particularly limited and can be selected appropriately. The composition for forming a low refractive index layer can contain, for example, a UV-curable resin, a fluorine-containing leveling agent, a silicon-containing slip agent, hollow silica fine particles, and a photopolymerization initiator.

[0014] <Ultraviolet-Curable Resin> The type of ultraviolet-curable resin forming the low refractive index layer is not particularly limited as long as it is a polyfunctional (meth)acrylate. In this type of film, the resin forming the low refractive index layer generally uses not only polyfunctional (meth)acrylates but also those made from reactive silicon compounds such as γ-acryloxypropyltrimethoxysilane as a starting material, but from the viewpoint of achieving both productivity and hardness, a composition containing an ultraviolet-curable polyfunctional (meth)acrylate as a main component is preferred.

[0015] The polyfunctional (meth)acrylate is not particularly limited, and examples thereof include (meth)acrylic derivatives of polyfunctional alcohols such as dipentaerythritol hexa(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,6-bis(3-(meth)acryloyloxy-2-hydroxypropyloxy)hexane, polyethylene glycol di(meth)acrylate, and polyurethane (meth)acrylate. In the present invention, polyurethane (meth)acrylate is particularly preferably used.

[0016] The polyfunctional (meth)acrylate may also be a fluorine-containing monomer. The fluorine-containing monomer having a structure in which fluorine atoms are introduced into the molecule as a fluorinated methylene group or a fluorinated methine group is a monomer in which almost all of the fluorine atoms are introduced into the molecule as a fluorinated methylene group or a fluorinated methine group, and any known monomer can be used as long as it is a polyfunctional monomer. That is, it may be any monomer having two or more (polyfunctional) monomers, or a mixture thereof. These fluorine-containing compounds can increase the strength and hardness of the cured film and improve the scratch resistance and abrasion resistance of the cured film surface. Among fluorine-containing compounds, fluorine-containing polyfunctional (meth)acrylates are preferred because they can form a crosslinked structure and produce cured films with high strength and hardness.

[0017] <Fluorine-containing leveling agent> The fluorine-containing leveling agent contained in the low refractive index layer can smooth the layer and impart fingerprint wiping properties, and can weaken the adhesion of fingerprints, which are lipids that adhere when touching the surface of the low refractive index layer, and improve the wiping properties of fingerprints. "Leveling" refers to the property of the paint flowing after application to form a flat and smooth coating film. Good leveling is judged when the surface of the coating film does not have many microscopic irregularities such as brush marks, yuzu peel (the texture of the surface of an orange), or undulations. The fluorine-containing leveling agents used in the present invention include C ２ ~C ７ Specific examples of suitable (meth)acrylates include Optool DAC-HP manufactured by Daikin Industries, Ltd. and Megafac RS-75 and RS-78 manufactured by DIC Corporation. In this specification, "(meth)acrylate" refers to acrylate and methacrylate.

[0018] The fluorine-containing leveling agent is preferably contained in the composition for forming a low refractive index layer in an amount of 1 to 20% by mass, more preferably 2.5 to 10% by mass. If the content is less than 1% by mass, it may not be possible to reduce the adhesion of fingerprints that are left on the surface of the low refractive index layer when touched. On the other hand, if the content exceeds 20% by mass, it may be difficult to obtain sufficient hardness and anti-reflection performance.

[0019] <Silicon-Containing Slip Agent> The silicon-containing slip agent contained in the low refractive index layer can impart scratch resistance to fabric. A slip agent is an additive that maintains the physical stability of a material when the thermoplastic resin is hot-molded, by preventing adhesion to metal surfaces, preventing adhesion between materials, improving the fluidity of the material, and reducing friction within the material or with a metal surface. Preferred examples of the silicon-containing slip agent used in the present invention include polydimethylsiloxane, and more preferably, polyether-modified polydimethylsiloxane having an acrylic group or polyester-modified polydimethylsiloxane having an acrylic group. Specific examples include BYK-UV3500, BYK-UV3530, and BYK-UV3570 manufactured by BYK Japan K.K.

[0020] The silicon-containing slip agent is preferably contained in the composition for forming the low refractive index layer in an amount of 5 to 20% by weight, more preferably 10 to 17.5% by weight. If the content is less than 5% by weight, the scratch resistance may be insufficient, while if the content is more than 20% by weight, it may be difficult to obtain sufficient hardness and anti-reflection performance.

[0021] In the present invention, the mass ratio of the silicon-containing slip agent to the fluorine-containing leveling agent contained in the low refractive index layer is preferably 9: 1 to 5: 5, and more preferably 7: 1 to 5: 5. If the mass ratio of the silicon-containing slip agent is greater than 9: 1, it may be difficult to obtain sufficient fingerprint wiping properties, while if the mass ratio of the fluorine-containing leveling agent is greater than 5: 5, it may be difficult to obtain sufficient fabric scratch resistance.

[0022] <Hollow Silica> The low refractive index layer in the present invention preferably contains hollow silica fine particles in order to lower the refractive index of the low refractive index layer. The hollow silica fine particles are silica (silicon dioxide, SiO ２ ) are formed into a nearly spherical shape and have a hollow portion within the outer shell. The average particle diameter is 10 to 100 nm, the shell thickness is approximately 1 to 60 nm, the porosity of the hollow portion is 40 to 45%, and the refractive index is low, at 1.20 to 1.29. Because the hollow portion contains air with a refractive index of 1.0, the cured film formed by curing the polyfunctional (meth)acrylate can have a low refractive index and low reflectance, and the inorganic fine particles known as silica fine particles can improve the scratch resistance and abrasion resistance of the cured film. If the porosity of the hollow portion is less than 40%, the amount of air in the hollow portion is small, making it impossible to achieve a low refractive index and low reflectance of the cured film. On the other hand, if the porosity of the hollow portion exceeds 45%, the outer shell must be made thin to increase the porosity, making its production difficult.

[0023] In addition, it is preferable that the hollow silica microparticles be modified with a silane coupling agent as necessary. This allows for an excellent effect not found in conventional (unmodified) silica microparticles or hollow silica microparticles, namely, excellent compatibility with polyfunctional (meth)acrylates. Therefore, when the modified hollow silica microparticles are mixed with polyfunctional (meth)acrylates, the aggregation of the modified hollow silica microparticles can be suppressed, and a cured film with excellent transparency and no whitening can be obtained. Furthermore, in the cured film, the polymerizable double bond of the silane coupling agent and the polymerizable double bond of the polyfunctional (meth)acrylate are copolymerized (chemically bonded) to form a strong cured film, thereby dramatically improving the scratch resistance and abrasion resistance of the cured film.

[0024] The mass ratio of hollow silica to resin material (low refractive index coating material in Example 1 described below) contained in the low refractive index layer is preferably 20:80 to 60:40, and more preferably 30:70 to 50:50. Increasing the amount of hollow silica fine particles added increases the surface irregularities, which can make it difficult to achieve both fingerprint wiping ability and scratch resistance. This is because fingerprints tend to be embedded in the surface and the particles tend to fall off.

[0025] <Other Components> The low refractive index layer may contain metal fluoride microparticles or the like to reduce the refractive index of the low refractive index layer. When metal fluoride microparticles are used, examples of the metal fluoride contained in the particles include magnesium fluoride, aluminum fluoride, calcium fluoride, and lithium fluoride. The metal fluoride microparticles are preferably in the form of particles, and their particle size (diameter) is not particularly limited, but is, for example, 10 to 200 nm, preferably 30 to 100 nm, more preferably 35 to 80 nm, and particularly preferably 45 to 65 nm. Furthermore, metal oxide microparticles (such as silica) may be contained to improve scratch resistance.

[0026] The composition for forming the low refractive index layer preferably contains a photoinitiator (photopolymerization initiator). The composition for forming the low refractive index layer may also contain a solvent.

[0027] [Hard Coat Layer] The antireflection film of the present invention has a hard coat layer between the substrate layer and the low refractive index layer. By providing the hard coat layer, the surface hardness and scratch resistance of the antireflection film are improved.

[0028] In addition, in an antireflection film having a laminate structure including a low refractive index layer, a high refractive index layer, and a hard coat layer, it is preferable that the hard coat layer is laminated between the substrate layer and the high refractive index layer. That is, it is preferable that these layers are laminated in the order of the substrate layer, the hard coat layer, the high refractive index layer, and the low refractive index layer. In an antireflection film having such a laminate structure, a high antireflection effect is realized and the surface hardness, i.e., the hardness of the surface opposite to the substrate layer, is improved.

[0029] The hard coat layer is preferably formed by a hard coat treatment performed on the surface of a substrate layer or the like. That is, the hard coat layer is preferably laminated by applying a hard coat material that can be cured by heat or active energy rays and then curing it. Examples of coating materials that can be cured using active energy rays include resin compositions composed of a single or multiple monofunctional or polyfunctional acrylate monomers or oligomers, more preferably resin compositions containing urethane acrylate oligomers. These resin compositions preferably contain a photopolymerization initiator as a curing catalyst. Examples of thermosetting resin coating materials include polyorganosiloxane-based and crosslinked acrylic-based coating materials. Such resin compositions are commercially available as hard coat agents for acrylic resins or polycarbonate resins, and can be selected appropriately taking into account suitability for the coating line. These coating materials may contain, as needed, organic solvents, as well as various stabilizers such as ultraviolet absorbers, light stabilizers, and antioxidants, as well as surfactants such as leveling agents, defoamers, thickeners, antistatic agents, and antifogging agents.

[0030] An example of a hard coat coating that is cured using active energy rays is one in which 1 to 10 parts by mass of a photopolymerization initiator is added to 100 parts by mass of a photopolymerizable resin composition obtained by mixing 40 to 95% by mass of a hexafunctional urethane acrylate oligomer and, for example, 5 to 60% by mass of a (meth)acrylate such as 2-(2-vinyloxyethoxy)ethyl (meth)acrylate [2-(2-vinyloxyethoxy)ethyl acrylate: VEEA].

[0031] The photopolymerization initiator may be any commonly known one, such as benzoin, benzophenone, benzoin ethyl ether, benzoin isopropyl ether, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, azobisisobutyronitrile, or benzoyl peroxide.

[0032] The refractive index of the hard coat layer is preferably similar to that of the substrate layer. Specifically, the hard coat layer preferably has a refractive index in the range of 1.43 to 1.65. The refractive index of the hard coat layer is more preferably 1.47 to 1.60, and even more preferably 1.49 to 1.57. The difference between the refractive index of the substrate layer and the refractive index of the hard coat layer is preferably 0.04 or less, more preferably 0.03 or less, and even more preferably 0.02 or less. In order to bring the refractive index of the hard coat layer closer to that of the substrate layer, a high refractive index component, as described below, may be added to the hard coat paint as appropriate.

[0033] The thickness of the hard coat layer is not particularly limited, but is preferably about 1 to 10 μm, more preferably about 2 to 8 μm, and even more preferably about 2 to 6 μm.

[0034] In order to reduce coating unevenness, it is preferable to use a leveling agent such as a silicone-based leveling agent or a fluorine-based leveling agent in the hard coat layer in order to reduce the surface tension of the coating film. Here, when a second cured layer is further formed on a first cured layer containing these leveling agents to improve the surface condition, the leveling agent present on the surface of the first cured layer may block the interface between the first cured layer and the second cured layer, and a bond connecting the first cured layer and the second cured layer may not be formed, resulting in poor adhesion. In addition, if the wettability of the first cured layer is low, repelling may occur when the second cured layer is applied, and the second cured layer may not be formed. Therefore, it is necessary to select an appropriate leveling agent to solve these problems.

[0035] Furthermore, if the first cured layer is not completely cured, when the second cured layer is formed, the leveling agent may be extracted by the second cured layer forming liquid and bleed out onto the second cured layer, which may affect the performance of the surface of the second cured layer.

[0036] [Substrate Layer] The substrate layer included in the anti-reflection film contains a thermoplastic resin. The type of thermoplastic resin is not particularly limited, and various resins such as polycarbonate (PC) resin, acrylic resin such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polyimide (PI), cycloolefin copolymer (COC), norbornene-containing resin, polyethersulfone, cellophane, aromatic polyamide, etc. Of these options, the thermoplastic resin of the substrate layer preferably contains at least a polycarbonate resin.

[0037] The type of polycarbonate resin contained in the substrate layer is not particularly limited as long as it contains an -[O-R-OCO]- unit (where R contains an aliphatic group, an aromatic group, or both an aliphatic group and an aromatic group, and further has a linear or branched structure) containing a carbonate bond in the molecular main chain. However, polycarbonates having a bisphenol skeleton are preferred, and polycarbonates having a bisphenol A skeleton or a bisphenol C skeleton are particularly preferred. As the polycarbonate resin, a mixture or copolymer of bisphenol A and bisphenol C may be used. The hardness of the substrate layer can be improved by using a bisphenol C-based polycarbonate resin, for example, a polycarbonate resin containing only bisphenol C, or a polycarbonate resin that is a mixture or copolymer of bisphenol C and bisphenol A. The viscosity average molecular weight of the polycarbonate resin is preferably 15,000 to 40,000, more preferably 20,000 to 35,000, and even more preferably 22,500 to 25,000.

[0038] The acrylic resin contained in the substrate layer is not particularly limited, but examples include homopolymers of various (meth)acrylic acid esters, such as polymethyl methacrylate (PMMA) and methyl methacrylate (MMA), copolymers of PMMA or MMA with one or more other monomers, and mixtures of multiple types of these resins. Examples of monomers include cyclic acid anhydride units, N-substituted maleimide units, aromatic vinyl compound units, and aliphatic vinyl compound units. Among these, (meth)acrylates containing a cyclic alkyl structure, which have low birefringence, low moisture absorption, and excellent heat resistance, are preferred. Examples of such (meth)acrylic resins include, but are not limited to, ACRYPET (manufactured by Mitsubishi Rayon), DELPET (manufactured by Asahi Kasei Chemicals), and PARAPET (manufactured by Kuraray). Using a mixture containing a polycarbonate resin and the above-mentioned acrylic resin is preferred because it can improve the hardness of the substrate layer, particularly the surface layer (the layer on the low refractive index layer side) of the substrate layer as a laminate.

[0039] The substrate layer may also contain additives other than the thermoplastic resin. For example, at least one additive selected from the group consisting of a heat stabilizer, an antioxidant, a flame retardant, a flame retardant assistant, an ultraviolet absorber, a release agent, and a colorant. Furthermore, the substrate layer may also contain additives such as an antistatic agent, a fluorescent brightener, an antifogging agent, a flow improver, a plasticizer, a dispersant, and an antibacterial agent.

[0040] The base layer preferably contains 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more of a thermoplastic resin, and the base layer preferably contains 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 75% by mass or more of a polycarbonate resin among the thermoplastic resins.

[0041] The substrate layer preferably has a refractive index in the range of 1.49 to 1.65, and more preferably about 1.49 to 1.60.

[0042] The thickness of the substrate layer is not particularly limited, but is preferably 30 to 1000 μm (1 mm), more preferably 50 to 700 μm, and particularly preferably 100 to 500 μm. The antireflection film may have two or more substrate layers, and when a plurality of substrate layers are provided, the total thickness of the substrate layers is, for example, 100 to 1000 μm, preferably about 200 to 500 μm.

[0043] Examples of substrate layers containing the above-mentioned multiple layers, i.e., substrate layers that are multilayer laminates, include the following: A layer of the above-mentioned polycarbonate resin (PC), such as bisphenol A, is laminated with an acrylic resin layer such as poly(methyl methacrylate) resin (PMMA: polymethyl acrylate and / or polymethyl methacrylate) as a surface layer (layer on the low refractive index layer side); a layer of a resin composed of a copolymer of the above-mentioned PMMA and one or more other monomers is laminated; a layer of a polycarbonate resin (PC) such as bisphenol A is laminated with a polycarbonate resin (PC) such as bisphenol C, etc. In a laminate in which a layer of a polycarbonate resin (PC) containing bisphenol A is laminated with a layer of a polycarbonate resin (PC) containing bisphenol C, for example, a layer of a polycarbonate resin containing bisphenol C is used as the surface layer. Furthermore, it is preferable to use a surface layer with high hardness, particularly one with a higher hardness than the other substrate layers.

[0044] The polycarbonate resin, which is the thermoplastic resin used in the laminate, is preferably the same as the polycarbonate resin forming the single-layer substrate layer. For example, a mixture or copolymer of bisphenol A and bisphenol C may be used. By using a bisphenol C-based polycarbonate resin, for example, a polycarbonate resin containing only bisphenol C, or a mixture or copolymer of bisphenol C and bisphenol A, the hardness of the surface layer (the layer on the low refractive index layer side) of the substrate layer, which is the laminate, can be particularly improved. To further improve the hardness, a mixture of a polycarbonate resin, for example, a bisphenol C-based polycarbonate resin, with the above-mentioned acrylic resin may be used.

[0045] [High Refractive Index Layer (Antireflection Layer)] In the antireflection film of the present invention, it is preferable to further include a high refractive index layer between the low refractive index layer and the hard coat layer to further reduce the reflectance. The high refractive index layer has a refractive index higher than that of the substrate layer and has the same antireflection function as the low refractive index layer. The high refractive index layer preferably contains a polymer of a resin material containing a fluorene-based diol, an isocyanate, and a urethane (meth)acrylate derived from a (meth)acrylate, and a (meth)acrylate. That is, the high refractive index layer is preferably a mixture of a urethane (meth)acrylate obtained by a dehydration condensation reaction of at least three components, a fluorene-based diol, an isocyanate, and a (meth)acrylate, and a (meth)acrylate.

[0046] In the above resin material, the ratio of urethane (meth)acrylate to (meth)acrylate is preferably 99:1 to 50:50 (weight ratio), more preferably 95:5 to 70:30, even more preferably 93:7 to 80:20, and particularly preferably 90:10 to 85:15.

[0047] The refractive index of the high refractive index layer is higher than that of the substrate layer, and the refractive index of the high refractive index layer is preferably 1.68 to 1.75, more preferably 1.69 to 1.74, and even more preferably about 1.70 to 1.73. The difference between the refractive index of the high refractive index layer and that of the substrate layer is preferably at least 0.09, more preferably at least 0.12, even more preferably at least 0.15, and particularly preferably at least 0.17. The difference between the refractive index of the high refractive index layer and that of the substrate layer is, for example, in the range of 0.03 to 0.70, preferably 0.10 to 0.50, and even more preferably 0.15 to 0.26. In this way, by increasing the difference between the refractive index of the high refractive index layer and that of the substrate layer, the reflectance of the surface of the antireflection film on the high refractive index layer side can be increased.

[0048] <High refractive index member> The high refractive index layer preferably contains a high refractive index member. The high refractive index member is added to increase the refractive index of the high refractive index layer. That is, by forming the high refractive index layer using a high refractive index member, the difference in refractive index between the high refractive index layer and the substrate layer can be increased, and the reflectance of the anti-reflection film can be further reduced. Examples of the high refractive index member include titanium oxide, zirconium oxide (ZrO ２ ), zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, ferric oxide, iron black, copper oxide, magnesium oxide, magnesium hydroxide, strontium titanate, yttrium oxide, hafnium oxide, niobium oxide, tantalum oxide (Ta ２ O ５ ), barium oxide, indium oxide, europium oxide, lanthanum oxide, zirconium oxide, tin oxide, and lead oxide, as well as their double oxides, such as lithium niobate, potassium niobate, lithium tantalate, and aluminum magnesium oxide (MgAl ２ O ４ ) and the like. Furthermore, rare earth oxides can be used as the high refractive index member, such as scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, and lutetium oxide. Of the many options mentioned above, zirconia (zirconium oxide) is preferred as the high refractive index member.

[0049] The high-refractive index member is preferably a particulate member. The particle size (diameter) of the particulate high-refractive index member is not particularly limited, but is, for example, 1 to 100 nm, preferably 5 to 50 nm, more preferably 7.5 to 30 nm, and particularly preferably 10 to 25 nm. Furthermore, for example, the particulate high-refractive index member preferably includes an organic layer coating as a surface treatment layer covering the outer surface of a metal oxide or the like. The organic layer coating improves the compatibility of the high-refractive index member with the resin material forming the high-refractive index layer, thereby enabling the high-refractive index member to be firmly bonded to the resin material. The surface treatment layer is preferably an organic layer coating with ultraviolet-reactive (curing) functional groups introduced onto the surface.

[0050] The high refractive index layer preferably contains the above-mentioned resin material and the high refractive index member in a weight ratio of 10:90 to 40:60, and the ratio of the above-mentioned resin material to the high refractive index member is more preferably 15:85 to 35:65, and even more preferably 20:80 to 30:70.

[0051] The thickness of the high refractive index layer is not particularly limited, but is preferably 10 to 300 nm, more preferably 30 to 250 nm, even more preferably 80 to 200 nm, and particularly preferably 130 to 170 nm.

[0052] <Other Components> The high refractive index layer or the resin material forming the high refractive index layer preferably contains at least one of a photoinitiator and a leveling agent, and particularly preferably contains a photoinitiator. In addition, the resin material may contain a solvent. Examples of the leveling agent include a fluorine-based leveling agent, an acrylic-based leveling agent, and a silicone-based leveling agent.

[0053] [Properties of Antireflection Film] <Reflectance (Luminous Reflectance)> The luminous reflectance of the surface of the antireflection film on the low refractive index layer side is 3.0% or less, preferably 1.6 to 2.8%, and more preferably 1.6 to 2.5%, as measured in accordance with JIS Z 8701. In the present invention, the luminous reflectance can be measured by the method described in the Examples below.

[0054] <Surface Roughness of Low Refractive Index Layer> The surface roughness of the low refractive index layer measured with an atomic force microscope (AFM) is 5.0 nm or less, preferably 4.5 nm or less, and more preferably 1.5 to 4.2 nm. In the present invention, the surface roughness of the low refractive index layer can be measured using the method described in the Examples below. Figure 2 shows a photograph showing the surface roughness Ra (nm) of the low refractive index layer surface measured with an atomic force microscope (AFM).

[0055] <Intensity Ratio of Silicon to Fluorine on the Surface of the Low Refractive Index Layer> The intensity ratio of silicon to fluorine on the surface of the low refractive index layer, I(Si) / I(F), measured with a glow discharge optical emission spectrometer, is 0.8 to 3.2, preferably 0.8 to 2.5, and more preferably 0.9 to 2.4. In the present invention, the intensity ratio I(Si) / I(F) can be measured using the method described in the Examples below.

[0056] <Fabric Scratch Resistance> The surface of the antireflection film on the low refractive index layer side preferably has excellent fabric scratch resistance. Specifically, a 100 g / cm ２ When the antireflection film of the present invention is reciprocated 100 times on the surface of the low refractive index layer side while applying a load of 100 times, it is preferable that no visible scratches are produced.

[0057] <Fingerprint Wiping Ease> The surface of the antireflection film on the low refractive index layer side preferably has excellent fingerprint wiping ability. Specifically, when the test described in the Examples below is carried out, it is preferable that fingerprints can be completely wiped off within five tries.

[0058] <Contact Angle of Oleic Acid> The contact angle of oleic acid on the surface of the low refractive index layer of the antireflection film is preferably 55° or more, and more preferably 58° to 75°. In the present invention, the contact angle of oleic acid can be measured by the method described in the Examples below.

[0059] [Method for manufacturing an anti-reflection film] In manufacturing an anti-reflection film, it is preferable to first form a substrate layer. In manufacturing the substrate layer, a material such as a resin composition is processed into a layer (sheet) by a conventional method. For example, extrusion molding or cast molding is used. An example of extrusion molding is a method in which pellets, flakes, or powder of a resin composition are melted and kneaded in an extruder, then extruded from a T-die or the like, and the resulting semi-molten sheet is cooled and solidified while being clamped between rolls to form a sheet.

[0060] A resin material is applied to the outer surface of one or more substrate layers and cured to form a hard coat layer or a low refractive index layer. Methods for curing the resin material include photocuring and heat curing.

[0061] [Resin Molded Article] Another embodiment of the present invention is a resin molded article having the above-described anti-reflection film on its surface. The resin molded article of the present invention can be obtained, for example, by molding a resin using an insert molding fusion method and simultaneously integrating an anti-reflection film onto the surface of the resin molded article. For example, an anti-reflection film can be held in a cavity within an injection molding mold and molten resin can be injected into the mold to obtain a resin molded article having an anti-reflection film integrated onto its surface. Examples of resin molded articles include films attached to the surfaces of computer screens, television screens, plasma display panels, etc., as well as films used on the surfaces of polarizing plates used in liquid crystal display devices, sunglass lenses, prescription eyeglass lenses, camera viewfinder lenses, various instrument covers, automobile glass, train glass, in-vehicle display panels, electronic device housings, etc.

[0062] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples and can be practiced with any modifications within the scope of the present invention.

[0063] [Example 1] A transparent substrate layer (DF02 manufactured by MGC Filsheet Co., Ltd.; total thickness: 254 μm) was used as the substrate, in which a methacrylic resin layer was laminated on a polycarbonate resin layer made of 2,2-bis(4-hydroxyphenyl)propane (bisphenol A). The refractive index of this transparent substrate layer was measured by the method described below, and was found to be 1.498.

[0064] A hard coat paint was prepared by mixing urethane acrylate UN-954 (manufactured by Negami Chemical Industrial Co., Ltd.), 5 mass% of 1-hydroxy-cyclohexyl-phenyl-ketone (Omnirad-184 manufactured by IGM Resin) as a photoinitiator, Futa-gent 681 (manufactured by Neos Corporation) as a leveling agent, and a solvent (propylene glycol monomethyl ether), and adjusting the concentration so that the solid content was 25 mass%.

[0065] To form a hard coat layer, the above-mentioned hard coat paint was applied to a dry film thickness of 3 μm, and dried at 80° C. for 2 minutes. Then, an ultraviolet curing device was used to apply an integrated light dose of 200 mJ / cm ２ The resulting hard coat film A was irradiated with ultraviolet light so that the refractive index became 1.501.

[0066] Next, a curable low refractive index coating material was prepared as follows. First, dry air was introduced into a five-necked flask equipped with a stirrer, thermometer, condenser, monomer dropping funnel, and dry air inlet tube to dry the system. Then, 58.9 parts by mass of 2,2,3,3-tetrafluoro-1,4-butanediol (C4DIOL manufactured by Exfluor Research Corporation), 279.8 parts by mass of pentaerythritol triacrylate, 0.5 parts by mass of dibutyltin laurate as a polymerization catalyst, and 500 parts by mass of methyl ethyl ketone as a solvent were added to the five-necked flask and heated to 60°C. After that, 161.3 parts by mass of isophorone diisocyanate was added and the reaction was allowed to proceed at 60-70°C. Consumption of the isocyanate residues in the reaction product was confirmed by infrared absorption spectroscopy, and the reaction was terminated to obtain a hexafunctional urethane acrylate oligomer. Furthermore, 2-(2-vinyloxyethoxy)ethyl acrylate (VEEA) was mixed with the urethane acrylate oligomer (urethane acrylate liquid) at a ratio of urethane acrylate liquid / VEEA=90 / 10 (mass %).

[0067] To the low refractive index paint thus obtained (liquid component of the resin material), hollow silica (JGC Catalysts and Chemicals Sururia 4320) was added and mixed at a ratio of hollow silica / resin material = 30 / 70 (mass%). Furthermore, 4 mass% of 1-hydroxycyclohexylphenylketone (Omnirad-184, manufactured by IGM Resin) as a photoinitiator, 17.5 mass% of BYK-UV3500 (manufactured by BYK-Chemie) as a silicon-containing slip agent, and 2.5 mass% of RS-78 (manufactured by DIC) as a fluorine-containing leveling agent were added and dissolved, and a solvent (propylene glycol monomethyl ether) was added to adjust the solids concentration to 3 mass%. The resulting low refractive index paint was designated Low Refractive Index Paint B-1. Note that the amounts of each material in the examples and comparative examples described below are all listed in mass% solids.

[0068] The low refractive index paint B-1 was applied to the above-mentioned hard coat film A so that the dry coating film would have a thickness of 100 nm, and dried at 80°C for 2 minutes. Then, the coating was cured with an ultraviolet curing device at an integrated ultraviolet light dose of 400 mJ / cm. ２In this way, a low refractive index layer having a thickness of 100 nm was formed on the outer surface of the hard coat film A, and an antireflection film C-1 was produced (see FIG. 1 : LR layer = low refractive index layer; HC layer = hard coat layer).

[0069] [Example 2] An anti-reflection film C-2 was produced in the same manner as in Example 1, except that a low refractive index paint B-2 was used, in which the concentration of the fluorine-containing leveling agent (RS-78) added in the low refractive index paint B-1 was changed to 10 mass %, and the concentration of the silicon-containing slip agent (BYK-UV3500) added was changed to 10 mass %.

[0070] [Example 3] An anti-reflection film C-3 was produced in the same manner as in Example 1, except that a low refractive index paint B-3 was used in which the ratio of hollow silica / resin material in the low refractive index paint B-1 was changed to 40 / 60 (mass%).

[0071] Example 4 An anti-reflection film C-4 was produced in the same manner as in Example 1, except that a low refractive index paint B-4 was used, in which the ratio of hollow silica / resin material in the low refractive index paint B-1 was changed to 40 / 60 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 10 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 10 mass%.

[0072] Example 5 An anti-reflection film C-5 was produced in the same manner as in Example 1, except that a low refractive index paint B-5 was used, in which the ratio of hollow silica / resin material in the low refractive index paint B-1 was changed to 40 / 60 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 10 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 5 mass%.

[0073] Example 6 An anti-reflection film C-6 was produced in the same manner as in Example 1, except that a low refractive index paint B-6 was used, in which the ratio of hollow silica / resin material in the low refractive index paint B-1 was changed to 40 / 60 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 20 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 10 mass%.

[0074] [Example 7] Anti-reflection film C-7 was produced in the same manner as in Example 1, except that low refractive index paint B-7 was used, in which the ratio of hollow silica / resin material in low refractive index paint B-1 was changed to 50 / 50 (mass%).

[0075] Example 8 An anti-reflection film C-8 was produced in the same manner as in Example 1, except that a low refractive index paint B-8 was used, in which the ratio of hollow silica / resin material in the low refractive index paint B-1 was changed to 50 / 50 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 10 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 10 mass%.

[0076] Comparative Example 1 An anti-reflection film C-9 was produced in the same manner as in Example 1, except that a low refractive index paint B-9 was used, in which the concentration of the fluorine-containing leveling agent (RS-78) added in the low refractive index paint B-1 was changed to 20 mass % and the concentration of the silicon-containing slip agent (BYK-UV3500) added was changed to 0 mass %.

[0077] Comparative Example 2 An anti-reflection film C-10 was produced in the same manner as in Example 1, except that a low refractive index paint B-10 was used, in which the addition concentration of the fluorine-containing leveling agent (RS-78) in the low refractive index paint B-1 was changed to 5 mass % and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 15 mass %.

[0078] Comparative Example 3 An antireflection film C-11 was produced in the same manner as in Example 1, except that a low refractive index coating material B-11 was used, in which the ratio of hollow silica / resin material in the low refractive index coating material B-1 was changed to 40 / 60 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 20 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 0 mass%.

[0079] Comparative Example 4 An antireflection film C-12 was produced in the same manner as in Example 1, except that a low refractive index coating material B-12 was used, in which the ratio of hollow silica / resin material in the low refractive index coating material B-1 was changed to 40 / 60 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 5 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 15 mass%.

[0080] Comparative Example 5 An antireflection film C-13 was produced in the same manner as in Example 1, except that a low refractive index coating material B-13 was used, in which the ratio of hollow silica / resin material in the low refractive index coating material B-1 was changed to 50 / 50 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 20 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 0 mass%.

[0081] Comparative Example 6 An antireflection film C-14 was produced in the same manner as in Example 1, except that a low refractive index coating material B-14 was used, in which the ratio of hollow silica / resin material in the low refractive index coating material B-1 was changed to 50 / 50 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 5 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 15 mass%.

[0082] Comparative Example 7 Antireflection film C-15 was produced in the same manner as in Example 1, except that low refractive index paint B-15 was used, in which the ratio of hollow silica / resin material in low refractive index paint B-1 was changed to 70 / 30 (mass%), the addition concentration of fluorine-containing leveling agent (RS-78) was changed to 15 mass%, and the addition concentration of silicon-containing slip agent (BYK-UV3500) was changed to 5 mass%.

[0083] Comparative Example 8 An antireflection film C-16 was produced in the same manner as in Example 1, except that a low refractive index coating material B-16 was used, in which the ratio of hollow silica / resin material in the low refractive index coating material B-1 was changed to 70 / 30 (mass%), the addition concentration of the fluorine-containing leveling agent (RS-78) was changed to 10 mass%, and the addition concentration of the silicon-containing slip agent (BYK-UV3500) was changed to 10 mass%.

[0084] Comparative Example 9 Antireflection film C-17 was produced in the same manner as in Example 1, except that low refractive index paint B-17 was used, in which the ratio of hollow silica / resin material in low refractive index paint B-1 was changed to 0 / 100 (mass%), the addition concentration of fluorine-containing leveling agent (RS-78) was changed to 10 mass%, and the addition concentration of silicon-containing slip agent (BYK-UV3500) was changed to 10 mass%.

[0085] The physical properties of the antireflection films of Examples 1 to 8 and Comparative Examples 1 to 9 thus produced were measured as follows. <Refractive Index> Using an Abbe refractometer (model: NAR-3T) manufactured by Atago Co., Ltd., the refractive index (nD) was measured at 20°C using the D line at a wavelength of 589 nm. For solutions containing a solvent, the refractive index was measured while the solvent was still present, and the refractive index of the solution from which the solvent had been removed was calculated from the measured value and the dilution ratio of the solvent.

[0086] <Surface Roughness of Low Refractive Index Layer> The surface roughness of the low refractive index layer was measured using a scanning probe microscope E-sweep (manufactured by SII NanoTechnology Inc.) under the following conditions: Cantilever: Si cantilever (manufactured by Hitachi High-Tech Science Corporation) Measurement range: 1 μm × 1 μm

[0087] <Silicon to Fluorine Intensity Ratio on the Low Refractive Index Layer Surface> Using a glow discharge optical emission analyzer GD-Profiler 2 (manufactured by Horiba, Ltd.), the surface of the low refractive index layer was measured in thermal relaxation slow pulse sputtering mode. To confirm the element ratio on the outermost surface, the silicon detection intensity I(Si) and fluorine detection intensity I(F) at the shortest sputtering time of 0.02 seconds were calculated, along with the fluorine detection intensity ratio I(Si) / I(F) calculated from the ratio. Gas type: High-purity Ne gas Electrode diameter: 4 mm Pulse frequency: 1000 Hz Number of seconds to capture: After 0.02 seconds

[0088] <Cloth abrasion resistance> Medical gauze Medigauze 4-fold (manufactured by Osaki Medical Co., Ltd.) at 100 g / cm ２ The film was reciprocated 100 times on the surface of the low refractive index layer of each of the films of the Examples and Comparative Examples with a load of 100. The presence or absence of scratches was visually determined and evaluated according to the following criteria: ◯: No scratches x: One or more scratches

[0089] <Reflectance (luminous reflectance)> Measurement was performed in accordance with JIS Z 8701 using SD7000 manufactured by Nippon Denshoku Industries Co., Ltd. In order to prevent reflection from the back surface (substrate layer side) of the film of each of the Examples and Comparative Examples, the measurement was performed after applying a black spray paint to the surface opposite the low refractive index layer and drying it.

[0090] <Fingerprint wiping ability> After dropping artificial fingerprint liquid (oleic acid) onto the surface of the sample, the artificial fingerprint liquid was spread thinly to a diameter of approximately 11 mm using a silicone pad. The artificial fingerprint liquid was passed over the sample with a 3M Japan Scotch-Brite No. 5000 cloth under a load of 500 g. The above test was repeated until the liquid was wiped off; if the liquid was completely wiped off after five tries, the sample was rated as having good fingerprint wiping ability (◯); if it took six or more tries, the sample was rated as having poor fingerprint wiping ability (×).

[0091] <Contact angle of water / oleic acid> Using an automatic contact angle meter DMo-601 (manufactured by Kyowa Interface Science Co., Ltd.), contact angles were measured using test solutions of water and oleic acid under the following conditions: Liquid volume: 2.0 μL Analysis method: θ / 2 method

[0092] The measurement results of the properties of the antireflection films of Examples 1 to 8 and Comparative Examples 1 to 9 are shown in Tables 1 and 2 below.

Claims

1. An anti-reflection film comprising a substrate layer containing a thermoplastic resin, and a hard coat layer which is a cured coating layer and a low refractive index layer having a refractive index lower than the refractive index of the hard coat layer by 0.05 or more, in this order, on at least one surface of the substrate layer, the low refractive index layer has a thickness of 70 to 130 nm and contains a fluorine-containing leveling agent and a silicon-containing slip agent; the surface roughness of the low refractive index layer measured by an atomic force microscope is 5.0 nm or less; an intensity ratio I(Si) / I(F) of silicon to fluorine at a surface of the low refractive index layer, measured by a glow discharge optical emission spectrometer, is 0.8 or more and 3.2 or less; The anti-reflection film has a luminous reflectance of 3.0% or less.

2. 2. The anti-reflection film according to claim 1, wherein the luminous reflectance of the anti-reflection film is 1.6 to 2.8%.

3. The antireflective film of claim 1 , wherein the low refractive index layer comprises hollow silica.

4. 4. The anti-reflection film according to claim 3, wherein a mass ratio of hollow silica to resin material contained in the low refractive index layer is 20:80 to 60:

40.

5. 10. The antireflective film of claim 1, wherein the silicon-containing slip agent is a polydimethylsiloxane-containing slip agent.

6. 2. The anti-reflective film according to claim 1, wherein the mass ratio of the silicon-containing slip agent to the fluorine-containing leveling agent contained in the low refractive index layer is from 9:1 to 5:

5.

7. 2. The anti-reflection film according to claim 1, wherein the contact angle of oleic acid on the surface of the low refractive index layer is 55° or more.

8. 10. The anti-reflective film of claim 1 for use in insert molding applications.

9. A resin molded product having an anti-reflection film according to claim 1 on a surface thereof.