Optical laminate, method for manufacturing the same, and use thereof

Abstract

The present invention provides an antireflection film which can suppress reflectance in a low wavelength region, can reduce light reflectance, and thus can improve the blackness of an image. To this end, the present invention provides an optical laminate in which an antiglare layer and a low-refractive layer are sequentially stacked on at least one side of a base material layer, wherein the skewness Rsk of the surface of the low-refractive layer is adjusted to be less than 0, the standard deviation σ of spectral reflectance in a wavelength range of 380 to 780 nm is adjusted to be 0.5 or less, and the light reflectance is adjusted to be 2.5 or less. The arithmetic mean roughness Ra of the surface of the low-refractive layer can be 0.01 to 0.5 μm, the maximum cross-sectional height Rt of a profile curve can be 0.1 to 1 μm, and the average length RSm of a profile curve element can be 1 to 50 μm. The haze of the optical laminate can be 30% or less, and the total light transmittance can be 90% or more. The glossiness 60° of the optical laminate can be 50% or less.

Description

[0001] This application is a divisional application of the application filed on June 11, 2021, with application number 202110651730.8 and title "Optical laminate and manufacturing method thereof and use". Technical Field

[0002] This invention relates to an optical laminate suitable for preventing reflection of external light sources on the display surface of various display devices, its manufacturing method, and its uses. Background Technology

[0003] To prevent reflections on the display surface of image display devices such as liquid crystal displays (LCDs) and organic electroluminescent displays (ELs), various low-reflection films have been proposed. For example, types with a low refractive index layer on the surface and types with layers of different refractive indices are known.

[0004] As a type of antireflective film with a low refractive index layer formed on its surface, Japanese Patent Application Publication No. 2008-3122 (Patent Document 1) discloses an antireflective film in which the surface resistivity of the low refractive index layer is 1×10⁻⁶. 10 (Ω / cm 2 Below, in addition, in L * a * b * In a color system, the reflected hue is 0 ≤ a. * ≤3 and -3≤b * ≤3.

[0005] Japanese Patent Application Publication No. 2010-2820 (Patent Document 2) discloses an antireflective film having a hard coating and an antireflective layer sequentially formed on a transparent substrate, wherein the hard coating comprises a conductive polymer, and the average light reflectance of the low refractive index layer surface is ( If the content of 0.5% or more and 1.5% or less, the surface resistivity of the low refractive index layer is 1×10⁻⁶. 10 (Ω / cm 2 )the following.

[0006] Japanese Patent No. 5846243 (Patent Document 3) discloses an optical laminate having a light-transmissive substrate and an antiglare layer provided on the light-transmissive substrate, wherein the surface of the antiglare layer has a concave-convex shape, the average inclination angle of the concave-convex portions is θa, the average roughness of the concave-convex portions is Rz, the average interval of the concave-convex portions is Sm, the ratio ψ of Rz to Sm is defined as ψ≡Rz / Sm, θa and Rz are measured with a reference length of 0.25 mm, Sm is measured with a reference length of 0.80 mm, and the optical laminate satisfies the following equations (I) and (II) at the same time: 1.2 degrees ≤ θa ≤ 2.5 degrees (I) 0.016 ≤ ψ ≤ 0.121 (II), the internal haze value of the optical laminate is 0% or more and 50% or less, and the surface haze value of the optical laminate is 0.5% or more and 4.5% or less.

[0007] Japanese Patent Application Publication No. 2014-145914 (Patent Document 4) discloses an antireflection film having a substrate, and sequentially from the substrate side, a middle refractive index layer, a high refractive index layer, and a low refractive index layer, the refractive index of the substrate is in the range of 1.45 to 1.65, the middle refractive index layer is formed by coating a middle refractive index layer-forming composition containing a binder resin and inorganic microparticles on the substrate and curing, the refractive index of the middle refractive index layer is in the range of 1.67 to 1.78, the thickness is 70 nm to 120 nm, the refractive index of the high refractive index layer is in the range of 2.00 to 2.60, the thickness is 10 nm to 25 nm, and the refractive index of the low refractive index layer is in the range of 1.35 to 1.55, the thickness is 70 nm to 120 nm.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2008-3122

[0011] Patent Document 2: Japanese Patent Application Publication No. 2010-2820

[0012] Patent Document 3: Japanese Patent No. 5846243

[0013] Patent Document 4: Japanese Patent Application Publication No. 2014-145914 SUMMARY

[0014] PROBLEMS TO BE SOLVED BY THE INVENTION

[0015] However, for types with a low-refractive-index layer on the surface, when the reflectance is measured in the visible light wavelength range, it has the characteristic that the reflectance spectrum has a minimum value near 550 nm, and the reflectance rises to about 3% on the lower wavelength side. Therefore, depending on the state of the low-refractive-index layer, the coloration can sometimes be very noticeable.

[0016] Therefore, the object of the present invention is to provide an anti-reflective film in a display device that can suppress reflectivity in low-wavelength regions, reduce light reflectivity, thereby improving the blackness of the image, as well as a method for manufacturing the same and its uses.

[0017] Problem Solving Methods

[0018] The inventors have discovered that by sequentially stacking an anti-glare layer and a low-refractive-index layer on at least one side of a substrate layer, adjusting the surface deviation Rsk of the low-refractive-index layer to less than 0, adjusting the standard deviation σ of the spectral reflectance in the wavelength range of 380~780nm to less than 0.5, and adjusting the light reflectance to less than 2.5, an anti-reflective film that can suppress reflectance in low-wavelength regions, reduce light reflectance, and thereby improve the blackness of images can be provided, thus completing the present invention.

[0019] That is, the optical laminate of the present invention comprises:

[0020] Substrate layer

[0021] An anti-glare layer laminated on at least one side of the substrate layer, and

[0022] A low-refractive-index layer with an uneven surface is stacked on top of the anti-glare layer.

[0023] The skewness Rsk of the aforementioned low-refractive-index layer surface is less than 0.

[0024] The optical laminate has a standard deviation σ of spectral reflectance of less than 0.5 in the wavelength range of 380~780nm and an optical reflectance of less than 2.5.

[0025] Regarding the aforementioned low-refractive-index layer surface, it can have the following characteristics: an arithmetic mean roughness Ra of 0.01~0.5 μm, a maximum cross-sectional height Rt of the profile curve of 0.1~1 μm, and an average length RSm of the profile curve element of 1~50 μm. Regarding the aforementioned optical laminate, it can have: a haze of 30% or less and a total light transmittance of 90% or more. The gloss 60° of the aforementioned optical laminate can be 50% or less. The aforementioned anti-glare layer can be a cured product of a curable composition containing a photocurable resin.

[0026] In the present application, a method for manufacturing the optical laminate described above is also included, the method including: providing a transfer surface of a transfer film as a molding die, forming a concavo-convex shape of an anti-glare layer in a shape reversed from the transfer surface of the anti-glare layer precursor in an anti-glare layer forming step (transfer step); and forming a low-refractive layer on the anti-glare layer in a low-refractive layer forming step.

[0027] The present application also includes a display device provided with the optical laminate described above. The display device can be a liquid crystal display device or an organic EL display.

[0028] Note that the various embodiments disclosed in the present specification can also be combined with any of the other features disclosed in the present specification.

[0029] Effects of the Invention

[0030] In the present application, an anti-glare layer and a low-refractive layer are sequentially layered on at least one side of a substrate layer, and the skewness Rsk of the surface of the low-refractive layer is adjusted to be less than 0, the standard deviation σ of the spectral reflectance in the wavelength range of 380 nm to 780 nm is adjusted to be 0.5 or less, and the light reflectance is adjusted to be 2.5 or less, so the reflectance in the low wavelength region can be suppressed, the light reflectance can be reduced, and the blackness of the image can be improved. Furthermore, on the basis of being able to balance such characteristics and anti-glare properties, coloring caused by the state of the low-refractive layer can also be suppressed, and the surface hardness can also be improved. DETAILED DESCRIPTION

[0031] [Low-refractive layer]

[0032] The optical laminate of the present application has a low-refractive layer (antireflection layer) layered on an anti-glare layer. The low-refractive layer has a surface concavo-convex shape with a skewness Rsk of less than 0. That is, the surface shape of the low-refractive layer has a negative Rsk, is a surface shape with many valleys, and has a surface shape with elongated and steep valleys (a shape with few elongated and steep peaks). For the optical laminate of the present application, unlike the existing antireflection film having a surface shape with many peaks and having an elongated and steep peak, a uniform low-refractive layer is formed across the entire concavo-convex shape in the surface concavo-convex shape with many valleys. Therefore, the optical laminate of the present application can suppress the reflectance in the low wavelength region and can also reduce the light reflectance.

[0033] The skewness Rsk (skewness) of the surface of the low-refractive layer is an index for evaluating the symmetry of the height distribution, and can be selected from the range of -10 to -0.1 or so, for example, -5 to -0.2, as long as it is less than 0. When Rsk is 0 or more, the reflectance in the low wavelength region cannot be suppressed.

[0034] The arithmetic average roughness Ra of the surface of the low-refractive-index layer is, for example, 0.01 to 0.5 μm, preferably 0.015 to 0.3 μm, further preferably 0.02 to 0.2 μm, more preferably 0.025 to 0.1 μm, and most preferably 0.03 to 0.05 μm. If Ra is too small, there is a risk that the anti-glare property will decrease, and if Ra is too large, there is a risk that the reflectance in the low-wavelength region and the light reflectance will increase.

[0035] The maximum section height Rt of the profile curve of the surface of the low-refractive-index layer is, for example, 0.1 to 1 μm, preferably 0.15 to 0.9 μm, further preferably 0.2 to 0.8 μm, more preferably 0.25 to 0.6 μm, and most preferably 0.3 to 0.4 μm. If Rt is too small, there is a risk that the anti-glare property will decrease, and if Rt is too large, there is a risk that the reflectance in the low-wavelength region and the light reflectance will increase.

[0036] The average length RSm of the profile curve elements of the surface of the low-refractive-index layer is, for example, 1 to 50 μm, preferably 3 to 30 μm, further preferably 5 to 25 μm, more preferably 10 to 20 μm, and most preferably 12 to 18 μm. If RSm is too small, there is a risk that it will be difficult to control the size of the concave-convex, and if RSm is too large, there is a risk that the anti-glare property will decrease.

[0037] Note that, in the present specification and claims, the skewness Rsk, the arithmetic average roughness Ra, the maximum section height Rt of the profile curve, and the average length RSm of the profile curve elements can be calculated from a curve obtained by measuring the concave-convex shape of the surface of the low-refractive-index layer using a non-contact surface / layer section shape measuring system [Riometer Co., Ltd., "VertScan 2.0"], and specifically, can be measured by the method described in the Examples below.

[0038] The refractive index of the low-refractive-index layer can be 1.37 or more, and is not particularly limited as long as it is smaller than the refractive index of the anti-glare layer, and is, for example, 1.37 to 1.45, preferably 1.37 to 1.4, further preferably 1.37 to 1.39, and more preferably 1.37 to 1.38. If the refractive index is too high, there is a risk that the anti-reflection property will decrease.

[0039] Note that, in the present specification and claims, the refractive index can be measured based on JIS K7142.

[0040] The thickness (average thickness) of the low-refractive-index layer is, for example, 50 to 300 nm, preferably 60 to 150 nm, further preferably 80 to 120 nm, and more preferably 90 to 110 nm.

[0041] The low refractive index layer can also be a layer formed of a low refractive index resin [e.g., a methylpentene resin, a diethylene glycol bis(allyl carbonate) resin, a polyvinylidene fluoride (PVDF), a polyvinyl fluoride (PVF), and the like fluorine resin, etc.], but from the viewpoint of mechanical properties and the like, it is preferable to be a layer formed of a cured product of a curable composition containing a curable resin, and containing a fluorine-containing compound and / or an inorganic filler having a low refractive index.

[0042] (Curable resin)

[0043] The curable resin can be any of a thermosetting resin, a photocurable resin, and from the viewpoint of productivity and the like, it is preferable to be a photocurable resin. The photocurable resin (photocurable resin precursor component) is a compound that can be cured or crosslinked by active energy rays such as ultraviolet rays, electron beams, and the like to form a resin, and can be a non-fluorine-containing photocurable resin.

[0044] The non-fluorine-containing photocurable resin contains a monomer, an oligomer (or a resin, particularly a low molecular weight resin).

[0045] As the monomer, for example, a monofunctional monomer [(meth)acrylate and the like (meth)acrylic monomer, vinyl pyrrolidone and the like vinyl monomer, isobornyl (meth)acrylate, adamantyl (meth)acrylate, and the like (meth)acrylate having a bridged cyclic hydrocarbon group, and the like], a bifunctional monomer [ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, and the like alkylene glycol di(meth)acrylate; diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyoxytetramethylene glycol di(meth)acrylate, and the like (poly)oxyalkylene glycol di(meth)acrylate; tricyclodecane dimethanol di(meth)acrylate, adamantane di(meth)acrylate, and the like di(meth)acrylate having a bridged cyclic hydrocarbon group], a trifunctional or higher polyfunctional monomer [glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylol ethane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like 3 to 6 functional monomer, and the like] and the like can be exemplified. Among these, a polyfunctional (meth)acrylate having at least 2 (meth)acryloyl groups is commonly used.

[0046] As the oligomer or resin, for example, the following can be exemplified: a (meth)acrylate of a bisphenol A-alkylene oxide adduct, an epoxy (meth)acrylate [a multifunctional epoxy (meth)acrylate having two or more (meth)acryloyl groups], a polyester (meth)acrylate [a multifunctional polyester (meth)acrylate having two or more (meth)acryloyl groups], a urethane (meth)acrylate [a multifunctional urethane (meth)acrylate having two or more (meth)acryloyl groups], a silicone (meth)acrylate [a multifunctional silicone (meth)acrylate having two or more (meth)acryloyl groups], a (meth)acrylic polymer having a polymerizable group, and the like.

[0047] These fluorine-free photocurable resins can be used alone or in combination of two or more. Among these, from the viewpoint of the mechanical properties of the antiglare layer, a multifunctional monomer of two or more functions, preferably a multifunctional monomer of three or more functions, further preferably a monomer of 3 to 6 functions [particularly a multifunctional (meth)acrylate having 3 to 6 (meth)acryloyl groups such as pentaerythritol tetra(meth)acrylate] can be used.

[0048] The fluorine-free photocurable resin preferably contains a multifunctional monomer of two or more functions (particularly a monomer of 3 to 6 functions) in an amount of 50% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more. The fluorine-free photocurable resin can also be a multifunctional monomer of two or more functions alone.

[0049] (Fluorine-containing compound and / or inorganic filler having a low refractive index)

[0050] The fluorine-containing compound includes a metal fluoride such as magnesium fluoride, a fluorine-containing photocurable resin, and the like. Among these, a fluorine-containing photocurable resin is commonly used.

[0051] The fluorine-containing photocurable resin can be a fluorinated compound of the monomer and the oligomer described above as the fluorine-free photocurable resin. As the fluorine-containing photocurable resin, for example, the following can be exemplified: a (meth)acrylic acid fluoroalkyl ester [for example, (meth)acrylic acid perfluoro-octyl ester, (meth)acrylic acid trifluoroethyl ester, and the like], a fluorinated (poly)oxyalkylene glycol di(meth)acrylate [for example, fluoroethylene glycol di(meth)acrylate, fluoropolyethylene glycol di(meth)acrylate, fluoropropylene glycol di(meth)acrylate, and the like], a fluorine-containing epoxy (meth)acrylate, a fluorine-containing urethane (meth)acrylate, and the like.

[0052] These fluorine-containing photocurable resins can be used alone or in combination of two or more. Among these, a fluoro-polyether compound having a (meth)acryloyl group, a fluorine-containing urethane (meth)acrylate, particularly a urethane (meth)acrylate containing fluorine and an ester are preferred.

[0053] As the inorganic filler of low refractive index, for example, metal compound particles such as metal oxide particles, metal nitride particles, metal sulfide particles, metal halide particles, etc. can be exemplified. As the metal of the metal compound, for example, Mg, Ca, B, Si, etc. can be exemplified.

[0054] These inorganic fillers can be used alone or in combination of two or more. Among these fillers, silica is preferred, and hollow silica is particularly preferred from the viewpoint of suppressing the increase in haze and improving transparency. The hollow silica can be the hollow silica described in Japanese Patent Application Publication No. 2001-233611, Japanese Patent Application Publication No. 2003-192994, etc.

[0055] The number average particle diameter of the above inorganic filler (particularly, hollow silica) is 100 nm or less, preferably 80 nm or less (for example, 10 to 80 nm), and further preferably about 20 to 70 nm.

[0056] The above inorganic filler can also be surface-modified with a coupling agent (titanium coupling agent, silane coupling agent).

[0057] The above curable composition can be adjusted to be of low refractive index by containing at least one of a fluorine-containing compound and an inorganic filler of low refractive index, and preferably contains a combination of a fluorine-containing compound and an inorganic filler of low refractive index from the viewpoint of excellent antireflection properties, etc.

[0058] In the case of combining a fluorine compound with the above inorganic filler, the proportion of the fluorine compound can be 0.1 parts by mass or more, for example, 0.1 to 1000 parts by mass, preferably 1 to 300 parts by mass, further preferably 3 to 100 parts by mass, and more preferably 5 to 50 parts by mass, with respect to 100 parts by mass of the above inorganic filler (particularly, hollow silica). If the proportion of the fluorine compound is too small, there is a risk that the antireflection properties will decrease.

[0059] The total proportion of the fluorine-containing compound and the above inorganic filler in the composition for forming a low refractive layer can be, for example, 1% by mass or more, and can be, for example, 5 to 90% by mass, with respect to the entire above composition.

[0060] (Curing agent)

[0061] The above curable composition can further contain a curing agent depending on the type of the curable resin. For example, for a thermosetting resin, an amine-based, a polycarboxylic acid-based, etc. curing agent can be contained, and for a photocurable resin, a photopolymerization initiator can be contained. As the photopolymerization initiator, conventional components such as acetophenone-based or propiophenone-based, benzoin-based, benzoin ether-based, benzophenone-based, thioxanthone-based, acylphosphine oxide-based, etc. can be exemplified.

[0062] The proportion of the curing agent such as photopolymerization initiator, for example, is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, and further preferably 1 to 5 parts by mass, relative to 100 parts by mass of the curable resin 100.

[0063] The curable composition can further contain a curing accelerator. In particular, the photocurable resin can contain a photocuring accelerator such as tertiary amines (dialkylamino benzoate, etc.), phosphine-based photopolymerization accelerators, and the like.

[0064] (Other components)

[0065] The curable composition described above can further contain other components in addition to the curable resin, the fluorine-containing compound, and / or the inorganic filler having a low refractive index. As the other components, conventional additives such as silane coupling agents (for example, silane coupling agents having a thiol group, etc.), leveling agents, stabilizers (antioxidants, ultraviolet absorbers, etc.), surfactants, water-soluble polymers, fillers other than the inorganic filler described above, crosslinking agents, colorants, flame retardants, lubricants, waxes, preservatives, viscosity modifiers, tackifiers, antifoaming agents, and the like can be exemplified.

[0066] The proportion of the other components, for example, is 0.01 to 100 parts by mass, preferably 0.1 to 10 parts by mass, and further preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the curable resin 100.

[0067] [Anti-glare layer]

[0068] The optical laminate of the present application can further include an anti-glare layer disposed on the lower layer of the low-refractive layer described above. The anti-glare layer can be laminated on at least one side of the substrate layer, or can be laminated on both sides, but is generally laminated on only one side from the viewpoints of workability, mechanical properties, productivity, and the like.

[0069] In the optical laminate of the present application, it is preferable that the low-refractive layer described above be formed in a substantially uniform thickness. Therefore, the anti-glare layer is also preferably provided with a surface shape substantially the same as that of the low-refractive layer. It can be presumed that, in the present application, by providing the anti-glare layer also with a surface concave-convex shape in which valleys are numerous and elongated and steep valleys are present, the reflectance and light reflectance in the low-wavelength region can be reduced for the following reasons. That is, in the case where the precursor used for forming the low-refractive layer is a liquid precursor such as the curable composition described above, when the surface shape of the anti-glare layer is a shape in which peaks are numerous and elongated and steep, the liquid precursor described above flows into the valleys, and thus the low-refractive layer becomes thin at the peak portions (particularly, near the peak top). In contrast, in the present application, the surface concave-convex shape of the anti-glare layer is a shape in which valleys are numerous and elongated and steep valleys are present, and thus the flow of the liquid precursor described above into the valleys can be suppressed, and thus a uniform low-refractive film can be formed, and the reflectance and light reflectance in the low-wavelength region can be reduced,

[0070] The skewness Rsk of the surface of the antiglare layer can be 0 or less, for example, -10 to -0.05, preferably -8 to -0.1, further preferably -5 to -0.3, more preferably -3 to -0.5, and most preferably -2 to -0.8. When Rsk is 0 or more, there is a risk that it is difficult to form a uniform low refractive index layer.

[0071] The arithmetic average roughness Ra of the surface of the antiglare layer is, for example, 0.01 to 0.5 μm, preferably 0.015 to 0.3 μm, further preferably 0.02 to 0.2 μm, more preferably 0.025 to 0.1 μm, and most preferably 0.03 to 0.05 μm.

[0072] The maximum surface height Rt of the profile curve of the surface of the antiglare layer is, for example, 0.1 to 1 μm, preferably 0.15 to 0.9 μm, further preferably 0.2 to 0.8 μm, more preferably 0.25 to 0.6 μm, and most preferably 0.3 to 0.4 μm.

[0073] The average length RSm of the profile curve elements of the surface of the antiglare layer is, for example, 1 to 50 μm, preferably 3 to 30 μm, further preferably 5 to 25 μm, more preferably 10 to 20 μm, and most preferably 12 to 18 μm.

[0074] The refractive index of the antiglare layer can be 1.53 or less, for example, 1.4 to 1.53, preferably 1.45 to 1.53, further preferably 1.48 to 1.53, and more preferably 1.5 to 1.53.

[0075] The thickness (average thickness) of the antiglare layer is, for example, 1 to 20 μm, preferably 1.5 to 10 μm, further preferably 2 to 8 μm, and more preferably 4 to 7 μm.

[0076] Note that, in the present specification and claims, the average thickness of the antiglare layer can be determined by measuring 10 arbitrary sites using an optical film thickness meter and calculating the average value.

[0077] The antiglare layer can have the characteristics of the optical laminate described later, and the material is not particularly limited. As the material constituting the antiglare layer, various transparent organic materials (thermoplastic resins, thermosetting resins, photocurable resins, etc.), inorganic materials (glass, ceramics, metals, etc.) can be selected, and from the viewpoint of improving the wettability with the antiglare layer described above, easily forming a uniform low refractive index layer by combining with the surface shape described above, a material containing a surface modifier is preferred, and from the viewpoint of also improving the mechanical properties, handleability, etc., a cured composition containing a surface modifier is particularly preferred.

[0078] (Curable resin)

[0079] The curable composition contains a curable resin, which can be any of a thermosetting resin, a photocurable resin, and the like, and is preferably a photocurable resin from the viewpoint of productivity and the like. As the photocurable resin, the photocurable resins exemplified in the item of the low-refractive layer and the like can be exemplified. The above-mentioned photocurable resin can be used alone or in combination of two or more.

[0080] Among the above-mentioned photocurable resins, a multifunctional monomer of two or more functions is preferred, and a combination of a 2- to 4-functional monomer (for example, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and the like) and a multifunctional monomer of 5 or more functions (for example, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like) is particularly preferred.

[0081] In the case where the photocurable resin is a combination of a 2- to 4-functional monomer and a multifunctional monomer of 5 or more functions, the mass ratio of the two can be selected from the range of about 1 / 99 to 90 / 10 of the former / the latter, for example, 3 / 97 to 50 / 50, further preferably 5 / 95 to 30 / 70, and more preferably 7 / 93 to 20 / 80.

[0082] (Surface adjusting agent)

[0083] The surface adjusting agent can have a surface tension reducing ability, and can be a conventional leveling agent. As the conventional leveling agent, for example, a silicone-based leveling agent, a fluorine-based leveling agent, an acetylene diol-based leveling agent, an acrylic-based leveling agent, and the like can be exemplified. These leveling agents can be used alone or in combination of two or more. Among these, from the viewpoint of improving the wettability (recoatability) of the low-refractive layer, a fluorine-containing leveling agent and / or a (meth)acrylic leveling agent is preferred.

[0084] As the fluorine-based leveling agent, a leveling agent having a fluorine aliphatic hydrocarbon skeleton is sufficient. As the fluorine aliphatic hydrocarbon skeleton, for example, fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluorotert-butane, fluoropentane, fluorohexane, and the like fluorine C 1-10 alkane, and the like can be exemplified. Among these fluorine aliphatic hydrocarbon skeletons, at least a part of the hydrogen atoms can be substituted with a fluorine atom, but a perfluoro aliphatic hydrocarbon skeleton in which all the hydrogen atoms are substituted with a fluorine atom is preferred.

[0085] Further, the fluorine aliphatic hydrocarbon skeleton can also form a polyfluoroalkylene ether skeleton as a repeating unit sandwiching an ether bond. As the fluorine aliphatic hydrocarbon group of the repeating unit, a fluorine C 1-4at least one of the alkylene groups. These fluorine-containing aliphatic hydrocarbon groups can be the same or a combination of a plurality of kinds. The number of repetitions (degree of polymerization) of the fluorine-containing alkylene ether unit can be, for example, 10 to 3000, preferably 30 to 1000, further preferably about 50 to 500.

[0086] As the fluorine-based leveling agent, a commercially available fluorine-based leveling agent can be used. As the commercially available fluorine-based leveling agent,For example, the following leveling agents can be exemplified: Optool series ("DSX", "DAC-HP") manufactured by Daikin Industries, Ltd., Surflon series ("S-242", "S-243", "S-420", "S-611", "S-651", "S-386", etc.) manufactured by AGC Seimi Chemical Co., Ltd., BYK series ("BYK-340", etc.) manufactured by BYK Japan K.K., AC series ("AC 110a", "AC 100a", etc.) manufactured by Algin Chemie, MEGAFACE series ("MEGAFACE F-114", "MEGAFACE F-410", "MEGAFACE F-444", "MEGAFACE EXP TP-2066", "MEGAFACE F-430", "MEGAFACE F-472SF", "MEGAFACE F-477", "MEGAFACE F-552", "MEGAFACE F-553", "MEGAFACE F-554", "MEGAFACE F-555", "MEGAFACE R-94", "MEGAFACE RS-72-K", "MEGAFACE RS-75", "MEGAFACE F-556", "MEGAFACE EXP TF-1367", "MEGAFACE EXP TF-1437", "MEGAFACE F-558", "MEGAFACE EXP TF-1537", etc.) manufactured by DIC Corporation, FC series ("FC-4430", "FC-4432", etc.) manufactured by Sumitomo 3M Co., Ltd., FTERGENT series ("FTERGENT 100", "FTERGENT 100C", "FTERGENT 110", "FTERGENT 150", "FTERGENT 150CH", "FTERGENT A-K", "FTERGENT 501", "FTERGENT 250", "FTERGENT 251", "FTERGENT 222F", "FTERGENT 208G", "FTERGENT 300", "FTERGENT 310", "FTERGENT 400SW", etc.) manufactured by Neos Corporation, PF series ("PF-136A", "PF-156A", "PF-151N", "PF-636", "PF-6320", "PF-656", "PF-6520", "PF-651", "PF-652", "PF-3320", etc.) manufactured by Kitamura Chemical Industry Co., Ltd., and the like.

[0087] As the (meth)acrylic leveling agent, any leveling agent having a (meth)acrylic skeleton can be used. As the (meth)acrylic skeleton, for example, a homopolymer or a copolymer of a (meth)acrylate, etc. can be exemplified. As the (meth)acrylate, for example, a (meth)acrylic acid alkyl ester such as a (meth)acrylic acid methyl ester, a (meth)acrylic acid ethyl ester, a (meth)acrylic acid butyl ester, a (meth)acrylic acid tert-butyl ester, a (meth)acrylic acid isobutyl ester, a (meth)acrylic acid hexyl ester, a (meth)acrylic acid octyl ester, a (meth)acrylic acid 2-ethylhexyl ester, etc.; a (poly)oxyalkylene glycol (meth)acrylate such as a diethylene glycol (meth)acrylate, a dipropylene glycol (meth)acrylate, a polyoxytetramethylene glycol (meth)acrylate, etc.; a polyester (meth)acrylate, etc. can be exemplified. These (meth)acrylates can be used alone or in combination of two or more. Among these, a (meth)acrylic acid C 1-10 a (meth)acrylic acid alkyl ester such as a (meth)acrylic acid alkyl ester and a (poly)oxyalkylene glycol (meth)acrylate.

[0088] As the (meth)acrylic leveling agent, a commercially available (meth)acrylic leveling agent can be used. As the commercially available (meth)acrylic leveling agent, for example, a leveling agent of the BYK series ("BYK-350", "BYK-354", "BYK-355", "BYK-356", "BYK-358N", "BYK-361N", "BYK-381", "BYK-392", "BYK-394", "BYK-399", "BYK-3440", "BYK-3441", etc.) manufactured by BYK Japan K.K., a leveling agent of the DISPARLON series ("DISPARLON 1970", "DISPARLON 230", "DISPARLON 230HF", "DISPARLON LF-1980", "DISPARLON LF-1980", "DISPARLON LF-1982", "DISPARLON LF-1983", "DISPARLON LF-1984", "DISPARLON LF-1985", "DISPARLON UVX-35", "DISPARLON UVX-36", etc.) manufactured by Nippon Shokubai Co., Ltd., etc. can be exemplified.

[0089] Among these, from the viewpoint of excellent wettability with the low refractive index layer, a (meth)acrylic leveling agent is particularly preferable.

[0090] The proportion of the surface modifier is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, further preferably 0.1 to 3 parts by mass, and more preferably 0.3 to 1 part by mass, relative to 100 parts by mass of the curable resin. When the proportion of the surface modifier is too small, there is a risk that the wettability with the low-refractive layer decreases, and when the proportion is too large, there is a risk that the mechanical properties of the antiglare layer decrease.

[0091] (Thermoplastic resin)

[0092] The curable composition described above can further contain a thermoplastic resin, in addition to the curable resin and the surface modifier, from the viewpoint of improving the mechanical properties of the antiglare layer.

[0093] As the thermoplastic resin, for example, a styrene-based resin, a (meth)acrylic polymer, an organic acid vinyl ester-based polymer, a vinyl ether-based polymer, a halogen-containing resin, a polyolefin (including alicyclic polyolefin), a polycarbonate, a polyester, a polyamide, a thermoplastic polyurethane, a polysulfone-based resin (polyether sulfone, polysulfone, etc.), a polyphenylene ether-based resin (polymer of 2,6-xylenol, etc.), a cellulose derivative (cellulose ester, cellulose carbamate, cellulose ether, etc.), a silicone resin (polydimethylsiloxane, polymethylphenylsiloxane, etc.), a rubber or elastomer (diene-based rubber such as polybutadiene or polyisoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylic rubber, urethane rubber, silicone rubber, etc.), or the like can be exemplified. These thermoplastic resins can be used alone or in combination of two or more. Among these thermoplastic resins, a cellulose ester is preferred.

[0094] As the cellulose ester, for example, cellulose acetate, cellulose triacetate, and the like; cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, and the like C 2-6 acid cellulose, and the like can be exemplified. These cellulose esters can be used alone or in combination of two or more. Among these, cellulose acetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, and the like C 2-4 acid cellulose are preferred, and cellulose acetate propionate and the like C 3-4 acid cellulose are particularly preferred.

[0095] The proportion of the thermoplastic resin is, for example, 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, further preferably 1 to 10 parts by mass, and more preferably 1.5 to 5 parts by mass, relative to 100 parts by mass of the curable resin.

[0096] (Curing agent)

[0097] The curable composition used for forming the antiglare layer can further contain the curing agent exemplified in the item of the low-refractive layer. The preferred embodiments and the proportion are also the same as those of the low-refractive layer.

[0098] (other additives)

[0099] The curable composition described above can further contain other components in addition to the curable resin, the fluorine-containing compound, and / or the inorganic filler having a low refractive index. As the other components, for example, conventional additives such as a silane coupling agent (for example, a silane coupling agent having a thiol group, etc.), a stabilizer (an antioxidant, an ultraviolet absorber, etc.), a surfactant, a water-soluble polymer, a filler, a crosslinking agent, a colorant, a flame retardant, a lubricant, a wax, a preservative, a viscosity modifier, a tackifier, an antifoaming agent, etc. can be exemplified.

[0100] The proportion of the other components is, for example, 0.01 to 100 parts by mass, preferably 0.1 to 10 parts by mass, and further preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the curable resin.

[0101] [substrate layer]

[0102] The substrate layer (light-transmissive substrate layer or transparent substrate layer) can be formed of a transparent material, and can be selected according to the use, and can be an inorganic material such as glass, but from the viewpoints of strength, moldability, etc., an organic material is often used. As the organic material, for example, cellulose ester, polyester, polyamide, polyimide, polycarbonate, (meth)acrylic polymer, etc. can be exemplified. Among these, cellulose ester, polyester, polycarbonate, etc. are often used, and cellulose derivative, polyester, polycarbonate is preferred.

[0103] As the cellulose ester, cellulose acetate such as triacetate cellulose (TAC), cellulose acetate propionate, cellulose acetate butyrate, etc. can be exemplified. 3-4 acid cellulose, etc.

[0104] As the polyester, for example, polyalkylene arylate such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc. can be exemplified.

[0105] As the polycarbonate, for example, bisphenol type polycarbonates such as bisphenol A type polycarbonate, etc. can be exemplified.

[0106] Among these, from the viewpoint of excellent balance of mechanical properties, transparency, optical isotropy, etc., cellulose acetate such as TAC, polyester such as PET, and particularly cellulose acetate is preferred.

[0107] The substrate layer can also contain the conventional additives exemplified in the anti-glare layer. The preferred embodiments and proportions are also the same as those of the anti-glare layer.

[0108] The substrate layer can also be a uniaxially or biaxially stretched film, but from the viewpoint of excellent low birefringence and optical isotropy, it can be an unstretched film.

[0109] The substrate layer can be subjected to surface treatment (e.g., corona discharge treatment, flame treatment, plasma treatment, ozone, ultraviolet irradiation treatment, etc.) or can have an easy-adhesion layer.

[0110] The thickness (average thickness) of the substrate layer is, for example, 5 to 2000 μm, preferably 15 to 1000 μm, further preferably 20 to 500 μm, and more preferably 30 to 100 μm.

[0111] [Properties of optical laminate]

[0112] The optical laminate of the present application is excellent in antireflection properties. In terms of the light reflectance of the optical laminate, it is 2.5 or less when measured from the low-refractive layer side, and from the aspect of antireflection properties, it is preferably 2.3 or less. The preferable range of the above light reflectance can be selected from the range of about 0.01 to 2.5, for example, 0.05 to 2.3, preferably 0.1 to 2.2, further preferably 0.3 to 2, and more preferably 0.5 to 1.8. When the light reflectance is too high, the visual recognition can be reduced due to the reflected light.

[0113] Note that, in the present specification and claims, the light reflectance can be measured based on JIS Z8722, and in detail, can be measured by the method described in the Examples below.

[0114] For the optical laminate of the present application, the standard deviation σ of the spectral reflectance in the wavelength range of 380 to 780 nm is 0.5 or less, and can be selected from the range of about 0.01 to 0.5, for example, 0.03 to 0.4, preferably 0.05 to 0.3, further preferably 0.08 to 0.2, and more preferably 0.1 to 0.15. When the standard deviation σ is too large, there is a risk that the reflectance in the low wavelength region becomes large, and the coloring according to the state of the low-refractive layer becomes conspicuous.

[0115] For the optical laminate of the present application, the wavelength at which the spectral reflectance shows a minimum value is, for example, 380 to 780 nm, preferably 400 to 700 nm, further preferably 450 to 650 nm, and more preferably 500 to 600 nm.

[0116] Note that, in the present specification and claims, the spectral reflectance can be measured based on JIS Z8722, and in detail, can be measured by the method described in the Examples below.

[0117] The optical laminate of the present application has a given light scattering property, and is excellent in anti-glare property. The haze of the optical laminate described above is, for example, 0.1 to 50%, preferably 1 to 30%, further preferably 3 to 20%, and more preferably 5 to 10%. If the haze is too small, there is a risk that the anti-glare property is reduced, and if the haze is too large, there is a risk that the visual recognition property is reduced.

[0118] Note that, in the present specification and claims, the haze can be measured based on JIS K7136, and in detail, can be measured according to the method described in the Examples described later.

[0119] The optical laminate of the present application is excellent in transparency. The total light transmittance of the optical laminate described above is, for example, 70% or more (for example, 70 to 100%), preferably 90 to 99%, further preferably 92 to 98%, and more preferably 93 to 97%. If the total light transmittance is too low, there is a risk that the transparency is reduced.

[0120] Note that, in the present specification and claims, the total light transmittance can be measured based on JIS K7361. In detail, it can be measured according to the method described in the Examples described later.

[0121] The optical laminate of the present application is also excellent in anti-glare property. The gloss 60° (gloss of the low-refractive layer surface) of the optical laminate described above can be 50% or less, and from the viewpoint of being able to balance the anti-glare property and the reflectance, for example, 5 to 50%, preferably 10 to 45%, further preferably 15 to 40%, and more preferably 20 to 35%. If the gloss is too large, there is a risk that the anti-glare property is reduced.

[0122] Note that, in the present specification and claims, the gloss 60° can be measured based on JIS Z8741. In detail, it can be measured according to the method described in the Examples described later.

[0123] The optical laminate of the present application is also large in hardness, and the pencil hardness can be HB or more, for example, F or more, preferably H or more, and further preferably 2H or more. If the pencil hardness is too low, in the case of being used for a cover sheet of a display device with a touch panel or the like, there is a risk that the protection function such as wear resistance is reduced.

[0124] Note that, in the present specification and claims, the pencil hardness can be measured by a method based on JIS K5600-5-4.

[0125] The optical laminate described above can be combined with a polarizing layer, a refractive index adjusting layer, an adhesive layer, and the like, which are functional layers that are conventionally used, in addition to the anti-glare layer described above and the low-refractive layer described above.

[0126] The thickness (average thickness) of the optical laminate described above is, for example, 3 to 2000 μm, preferably 5 to 1000 μm, and further preferably 10 to 500 μm.

[0127] [Method for manufacturing optical laminate]

[0128] As the method for manufacturing the optical laminate of the present application, any method can be used as long as the low-refractive layer is imparted with the surface shape described above, and a method including the following steps is preferred: a step of forming a concavo-convex shape on the antiglare layer (antiglare layer forming step); and a step of laminating the low-refractive layer on the antiglare layer (low-refractive layer forming step).

[0129] In the antiglare layer forming step, as a method of forming a concavo-convex shape on the antiglare layer, a conventional method can be used. As the conventional method, for example, a method of forming a concavo-convex shape using particles (for example, a method of forming a convex portion following the shape of the particles, etc.); a method of allowing the resin component of a curable composition containing a resin component capable of undergoing phase separation to undergo phase separation and then curing; a method of transferring using a mold having a concavo-convex shape on the surface (for example, a method based on compression molding using a roll, etc.); a method of forming a concavo-convex shape by cutting (for example, cutting using a laser, etc.); a method of forming a concavo-convex shape by polishing (for example, a sandblasting method, a bead blasting method, etc.); a method of forming a concavo-convex shape by etching, etc. can be exemplified.

[0130] Among these, from the viewpoint of productivity, etc., a method of forming a concavo-convex shape on the transfer surface of the transfer film as a molding mold, and forming a concavo-convex shape having a shape inverted from the transfer surface of the antiglare film precursor is preferred.

[0131] The concavo-convex shape of the surface of the antiglare layer of the present application is a shape inverted from the surface concavo-convex shape of the conventional antiglare film having a fine peak, and therefore, the conventional antiglare film can be used as a molding mold (transfer film).

[0132] In order to improve the peeling property from the antiglare layer, the transfer film can contain a fluorine-containing compound. As the fluorine-containing compound, the fluorine-containing compounds exemplified in the item of the low-refractive layer, the fluorine-based leveling agent exemplified in the item of the antiglare layer, etc. can be exemplified. Among these, the fluorine-based leveling agent is preferred. The proportion of the fluorine-containing compound is 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, and further preferably 1 to 3 parts by mass, with respect to 100 parts by mass of the resin component constituting the transfer film.

[0133] In order to improve the peeling property from the antiglare layer, the transfer film can further have a low-refractive layer laminated on the surface. The low-refractive layer is the same as the low-refractive layer of the optical laminate described above, and includes the preferred embodiments. This is particularly effective in the case where the transfer film does not contain a fluorine-based leveling agent.

[0134] In the transfer film, in order to form the target concavo-convex shape on the surface of the anti-glare layer as the transferred surface, the skewness Rsk of the transferred surface is, for example, 0 to 5, preferably 0 to 3, and further preferably 0 to 1.

[0135] The arithmetic average roughness Ra of the transferred surface is, for example, 0.01 to 0.5 μm, preferably 0.03 to 0.4 μm, and further preferably 0.05 to 0.3 μm.

[0136] The maximum section height Rt of the profile curve of the transferred surface is, for example, 0.1 to 3 μm, preferably 0.2 to 2 μm, and further preferably 0.3 to 1 μm.

[0137] The average length RSm of the profile curve elements of the transferred surface is, for example, 1 to 50 μm, preferably 3 to 40 μm, and further preferably 5 to 30 μm.

[0138] In the above anti-glare layer forming process (transfer process), as a method of transferring the target concavo-convex shape to the anti-glare layer precursor of the transferred surface, there is no particular limitation as long as the anti-glare layer precursor in a state of being able to follow the concavo-convex shape of the transferred surface of the transfer film is brought into contact with the transferred surface, the above precursor is solidified or cured, and then the solidified or cured anti-glare layer is peeled from the transfer film, and a conventional method can be appropriately selected depending on the type of the anti-glare layer. As a specific method, there can be a method in which the transfer film is embedded in a mold, a liquid anti-glare layer precursor is injection-molded in the mold, and then the solidified anti-glare layer is peeled from the transfer film (in-mold molding method); a method in which a liquid anti-glare layer precursor is applied (coated) to the transferred surface of the transfer film, solidified, and then the solidified anti-glare film is peeled from the transfer film (application method); a method in which a deformable anti-glare layer precursor (film-like precursor) that is not yet solidified is laminated to the transfer film, the above precursor is solidified, and then the solidified anti-glare film is peeled from the transfer film (laminating method); and the like. As the anti-glare film precursor, there can be exemplified a thermoplastic resin in a molten state, a non-solidified curable resin (or a curable composition containing a curable resin), and the like. Among these methods, the laminating method is preferred from the viewpoint of productivity and the like.

[0139] In the laminating method, as the anti-glare layer, a laminated film of a base material layer and an anti-glare layer formed of a cured product of a curable composition containing a photocurable resin laminated to at least one surface of the base material layer is preferred. In the laminating method for manufacturing such a laminated film, first, an anti-glare layer precursor can be prepared by applying a curable composition containing a photocurable resin to at least one surface of a base material layer and drying.

[0140] The above-described curable composition may contain a solvent. The solvent can be selected based on the type and solubility of the photocurable resin, and should be able to uniformly dissolve at least the solid components (e.g., photocurable resin, polymer components, photopolymerization initiator, other additives). Examples of such solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.) and ethers (diethyl ethyl ketone, methyl ethyl ketone, cyclohexanone, etc.). The solvents include alkanes, tetrahydrofurans, aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), carbon halides (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosols [methyl cellosol, ethyl cellosol, propylene glycol monomethyl ether (1-methoxy-2-propanol), etc.], acetic acid cellosols, sulfoxides (dimethyl sulfoxide, etc.), and amides (dimethylformamide, dimethylacetamide, etc.). Additionally, the solvent can be a mixture. Among these solvents, aliphatic ketones such as methyl ethyl ketone and methyl isobutyl ketone are preferred.

[0141] The concentration of the solute (photocurable resin, thermoplastic resin, curing agent, other additives) in the composition can be selected within a range that does not impair the castability, coating properties, etc., for example, 1 to 80% by mass, preferably 10 to 70% by mass, further preferably 15 to 50% by mass, and most preferably 20 to 30% by mass.

[0142] Commonly used coating methods include: roller coating, air knife coating, doctor blade coating, bar coating, reverse coating, wire-wound bar coating, corner wheel coating, dip-squeeze coating, die coating, gravure coating, micro-gravure coating, screen coating, dip coating, spray coating, and spin coating. Among these methods, wire-wound bar coating and gravure coating are frequently used. It should be noted that, depending on the requirements, the coating solution can be applied multiple times.

[0143] The solvent can be evaporated by drying after casting or coating the above composition. Drying can also be natural drying, but depending on the boiling point of the solvent, drying can be carried out at a temperature of, for example, 30~200°C, preferably 50~150°C, and more preferably 80~120°C.

[0144] The anti-glare layer precursor obtained as described above is laminated with a transfer film using a conventional laminator such as a roller laminator. In detail, by laminating the anti-glare layer precursor and the transfer film in such a way that the coating layer of the precursor formed by the curable composition is in contact with the transfer surface of the transfer film, a laminate in which the anti-glare layer precursor and the transfer film are integrally formed can be obtained.

[0145] After the obtained laminate is cured by light irradiation, the transfer film is peeled from the laminate, whereby the antiglare layer is obtained. The light irradiation can be selected according to the kind of the photocurable resin, etc., and ultraviolet rays, electron beams, etc. can be generally used. The light source is usually an ultraviolet irradiation device.

[0146] As the light source, for example, in the case of ultraviolet rays, a Deep UV lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a halogen lamp, a laser light source (helium-cadmium laser, excimer laser, etc.), or the like can be used. The amount of light irradiation (irradiation energy in terms of cumulative light amount) differs depending on the thickness of the coating film, and is, for example, 10 to 10,000 mJ / cm 2 , preferably 20 to 5,000 mJ / cm 2 , further preferably 30 to 3,000 mJ / cm 2 . The light irradiation can also be performed in an atmosphere of an unreactive gas, as needed.

[0147] In the low-refractive layer forming step, as a method of laminating the low-refractive layer, a conventional method can be used, and a method of applying and drying a coating solution obtained by dissolving or dispersing a composition for forming the low-refractive layer in a solvent can be used. In the case where the above-mentioned composition contains a photocurable resin, curing after drying can be performed by the same method as the antiglare layer. The application method also includes preferred embodiments and is the same as the antiglare layer forming step.

[0148] As the solvent, the solvent used in the above-mentioned antiglare layer forming step can be used. Among the above-mentioned solvents, an alcohol such as isopropyl alcohol (2-propanol) is preferred. The drying temperature is, for example, 30 to 200°C, preferably 50 to 120°C, further preferably 60 to 100°C.

[0149] The concentration of the solute (resin component, fluorine-containing compound, inorganic filler, etc.) in the composition can be selected from the range of about 0.1 to 50 mass% within a range not impairing the flowability, coatability, etc., and is, for example, 1 to 3 mass%, preferably 1.5 to 3 mass%, further preferably 1.8 to 3 mass%, more preferably 2 to 3 mass%, from the viewpoint of easily forming a target concavo-convex shape on the surface of the antiglare layer.

[0150] [Display device]

[0151] The optical laminate of the present application is excellent in antiglare property and antireflection property, and thus can be used as an antireflection film in various display devices such as a liquid crystal display device (LCD), an organic EL display, etc., and is particularly useful in a high-fineness LCD, an organic EL display, etc.

[0152] In detail, the LCD can be a reflective type LCD that illuminates a display unit having a liquid crystal cell using external light, or a transmissive type LCD that has a backlight unit for illuminating the display unit. In the reflective type LCD, incident light from the outside can be introduced via the display unit, and a reflection member can be used to reflect transmitted light that has passed through the display unit, thereby illuminating the display unit. In the reflective type LCD, the optical stack described above can be disposed in an optical path in front of the reflection member. For example, the optical stack described above can be disposed or layered on a front surface of the display unit (a front surface on the visible side), and in particular, on a front surface of an LCD having a collimating backlight unit and not having a prism sheet.

[0153] In the transmissive type LCD, the backlight unit can also have a light guide plate (for example, a light guide plate having a wedge-shaped cross section) for causing light from a light source (a tubular light source such as a cold cathode tube, or a point light source such as a light emitting diode) to be incident from one side and to be emitted from an emission surface on the front surface. In addition, a prism sheet can be disposed on the front surface side of the light guide plate as needed. Note that, generally, a reflection member for reflecting light from the light source toward the emission surface is disposed on the back surface of the light guide plate. In such a transmissive type LCD, the optical stack described above can be disposed in an optical path in front of the light source, for example, the optical stack described above can be disposed or layered on a front surface of the display unit.

[0154] In the organic EL display, each pixel of the organic EL includes a light emitting element that is generally formed of a cathode electrode of metal or the like / electron injection layer / electron transport layer / light emitting layer / hole transport layer / hole injection layer / anode electrode of ITO or the like / glass plate / transparent plastic plate or the like substrate. The optical stack described above can also be disposed in an optical path in the organic EL display.

[0155] Embodiments

[0156] Hereinafter, the present application will be described in more detail with reference to Examples, but the present application is not limited to these Examples. The details of the raw materials and films used in the Examples and Comparative Examples and the method of preparing the coating solution are described below, and the optical stacks obtained in the Examples and Comparative Examples were evaluated by the following methods.

[0157] [Raw materials]

[0158] Anti-glare coating agent: "TOMAX FA-3317M" manufactured by Nippon Paint Co., Ltd., 50 mass% of solid content

[0159] Haze adjustment transparent coating agent: "TOMAX FA-3317C" manufactured by Nippon Paint Co., Ltd., 50 mass% of solid content

[0160] Fluorine-containing UV reactive surface modifier: "MEGAFACE RS-75" manufactured by DIC Corporation

[0161] Dipentaerythritol hexaacrylate: "DPHA" manufactured by Dicel Ornex Corporation

[0162] Pentaerythritol tri- and tetraacrylate: "Aronix M-305" manufactured by Toagosei Corporation

[0163] Cellulose acetate propionate: "CAP-482-20" manufactured by Eastman Company, degree of acetylation = 2.5%, degree of propionylation = 46%, polystyrene-equivalent number average molecular weight = 75,000

[0164] Acrylic leveling agent: "BYK3440" manufactured by BYK Company

[0165] Photopolymerization initiator: "Omnirad 184" manufactured by IGM Resins Company

[0166] Antireflection coating solution A: "ELCOM P-5062" manufactured by Showa Denko K.K., solid content 3 mass%,

[0167] Fluorine-containing curable compound solution: "KY-1203" manufactured by Shokubai Co., Ltd., solid content 20 mass%

[0168] Antireflection coating solution B: "Opstar SB023" manufactured by Arakawa Chemical Industries, Ltd., solid content 10 mass%

[0169] [Membrane]

[0170] Transfer film A: "PF11-007F" manufactured by Dicello Corporation

[0171] Transfer film B: "PK27-100" manufactured by Dicello Corporation

[0172] PET film: "O321" manufactured by Mitsubishi Chemical Corporation, thickness 75 μm or 100 μm

[0173] TAC film: "Fuji-TAC TG60UL" manufactured by Fuji Photo Film Co., Ltd., thickness 60 μm

[0174] [Preparation of transfer coating solution for forming transfer film C]

[0175] A haze coating agent 80 parts by mass, a haze adjusting transparent coating agent 20 parts by mass for adjusting the haze of the haze coating agent, a fluorine-containing radical ultraviolet reactive surface modifier 1 part by mass, a mixed solvent of propylene glycol monomethyl ether and methyl ethyl ketone [former / latter = 70 / 30 (mass ratio)] 4.5 parts by mass were mixed to prepare a transfer coating solution.

[0176] [Preparation of a haze coating solution for forming a haze layer]

[0177] A dipentaerythritol hexaacrylate 90 parts by mass, pentaerythritol tri- and tetraacrylate 10 parts by mass, cellulose acetate propionate 2 parts by mass, an acrylic leveling agent 0.5 parts by mass, a photopolymerization initiator 2 parts by mass were dissolved in a mixed solvent of methyl ethyl ketone 170 parts by mass and methyl isobutyl ketone 170 parts by mass to prepare a haze coating solution.

[0178] [Preparation of an antireflection coating solution 1]

[0179] An antireflection coating solution A 100 parts by mass, a fluorine-containing curable compound solution 1.5 parts by mass, and isopropyl alcohol 36 parts by mass were mixed to prepare an antireflection coating solution 1.

[0180] [Preparation of an antireflection coating solution 2]

[0181] An antireflection coating solution B 100 parts by mass, methyl isobutyl ketone 317 parts by mass were mixed to prepare an antireflection coating solution 2.

[0182] [Thickness of a haze layer]

[0183] An optical film thickness meter was used to measure any 10 sites in the obtained laminate in the examples and comparative examples, and an average value was calculated.

[0184] [Surface shape]

[0185] Based on JIS B0601, a non-contact surface / layer cross-sectional shape measuring system [RiCO System Co., Ltd., "VertScan 2.0"] was used to measure the concave-convex shape of the antireflection layer surface under an objective lens of 50 times, a field of view of 253 μm x 189 μm, and based on the obtained profile curve, skewness Rsk, arithmetic average roughness Ra, maximum cross-sectional height of the profile curve Rt, and average length of profile curve elements RSm were respectively calculated.

[0186] [Haze]

[0187] Based on JIS K7136, a haze meter (Nippon Denshoku Industries Co., Ltd., "NDH5000W") was used to measure the haze of the haze antireflection film obtained in the examples and comparative examples, in a manner such that the antireflection layer surface was on the light receiver side.

[0188] [Total light transmittance]

[0189] Based on JIS K7361, the total light transmittance of the antireflection film obtained in the examples and comparative examples was measured using a haze meter ("NDH5000W" manufactured by Nippon Denshoku Industries Co., Ltd.).

[0190] [Standard deviation σ of spectral reflectance and light reflectance Y]

[0191] An adhesive surface was formed by adhering OCA (optically clear adhesive) to the surface on the side opposite to the antireflection layer in a manner so as not to affect the reflection from the back surface, and a black acrylic plate was adhered to the adhesive surface, thereby producing a measurement sample. Next, the spectral reflectance was measured for the surface of the measurement sample on the side of the antireflection layer using a reflection spectrophotometer ("U-3900H" manufactured by Hitachi High-Tech Science Corporation) based on JIS Z8722. The standard deviation σ of the spectral reflectance and the light reflectance Y were calculated from the obtained spectrum of the reflectance.

[0192] [Gloss]

[0193] Based on JIS Z8741, the 60° gloss of the antiglare film obtained in the examples and comparative examples was measured using a gloss meter ("Polygloss KT-GL0030" manufactured by TQC Corporation).

[0194] [Pencil hardness]

[0195] Based on JIS K5600-5-4, the scratch hardness based on the pencil method was measured.

[0196] Example 1 (Production of Antireflection Film)

[0197] An antiglare coating solution was applied to a PET film (thickness 75 μm) using a wire bar, and dried in an oven at 100°C for 1 minute to form a coating layer (transferred layer) in a manner so that the coating film thickness would be 6 μm. Next, a transfer film A (antiglare layer A1) was disposed so that the transferred surface would be in contact with the application surface (transferred surface) of the transfer film A, and passed through a roll laminator (manufactured by Toshiba Machine Co., Ltd.), thereby producing a laminate. Further, the transfer film A was irradiated with a cumulative light amount of 150 mJ / cm 2The transfer film A was peeled off after the irradiation of the ultraviolet rays, and an antiglare film 1 (antiglare layer A2) was produced. Next, the anti-reflection coating solution 1 was applied on the antiglare layer A2 using a wire bar coater, and dried in an oven at 80°C for 1 minute. Then, the unhardened coating layer was irradiated with ultraviolet rays of a cumulative light amount of 400 mJ / cm 2 The anti-reflection layer (low refractive index layer) Dl (thickness of about 100 nm) was formed by irradiation of ultraviolet rays of a cumulative light amount of 400 mJ / cm

[0198] Example 2 (Production of Anti-Reflection Film)

[0199] The transfer film B (antiglare layer Bl) was used instead of the transfer film A, and otherwise, the anti-reflection film 2 (antiglare layer B2, anti-reflection layer Dl) was produced in the same manner as in Example 1.

[0200] Example 3

[0201] (Production of Transfer Film C)

[0202] The transfer coating solution was applied on a PET film (thickness of 100 μm) using a wire bar, and dried in an oven at 60°C for 1 minute to form a coating layer (transfer layer) in a manner such that the coating film thickness was 6 μm. Next, the transfer layer was irradiated with ultraviolet rays of a cumulative light amount of 100 mJ / cm 2 The transfer film C was produced.

[0203] (Production of Anti-Reflection Film)

[0204] The TAC film (thickness of 60 μm) was used instead of the PET film, and the above-described transfer film C (antiglare layer Cl) was used instead of the transfer film A, and otherwise, the anti-reflection film 3 (antiglare layer C2, anti-reflection layer Dl) was produced in the same manner as in Example 1.

[0205] Example 4

[0206] The anti-reflection film 4 (antiglare layer C2, anti-reflection layer D2) was produced in the same manner as in Example 3 except that the anti-reflection coating solution 2 was used.

[0207] Comparative Examples 1 to 3

[0208] The surfaces of the transfer films A to C used in Examples 1 to 3 were subjected to corona treatment, and the anti-reflection layer was produced in the same manner as in each of the examples on the surfaces after the corona treatment, and used as a comparison.

[0209] The evaluation results of the anti-reflection films obtained in the examples and comparative examples are shown in Table 1.

[0210]

[0211] From the results of Table 1, it can be confirmed that the optical laminate of the example has lower reflectance, lower glossiness 60°, higher anti-glare property, and lower σ of spectral reflectance, and coloring caused by the state of the low refractive index layer is not apparent, as compared with the optical laminate of the comparative example.

[0212] Industrial applicability

[0213] The optical laminate of the present application can be used as an anti-reflection film used on the surface of various display devices, such as a liquid crystal display device (LCD), a cathode tube display device, an organic or inorganic electroluminescence (EL) display, a field emission display (FED), a surface electric field display (SED), a rear projection television display, and the like, and in particular, is suitable for uses requiring high-fineness images, such as a game machine, a smart phone, a personal computer (PC) (a tablet PC, a notebook or laptop PC, a desktop PC, and the like), a computer pointing device such as a pen tablet, a display device such as a television, and the like.

Claims

1. An optical laminate comprising: Substrate layer An anti-glare layer laminated on at least one side of the substrate layer, and A low-refractive-index layer with an uneven surface is stacked on top of the anti-glare layer. The anti-glare layer is a cured product of a curable composition comprising a photocurable resin and a (meth)acrylic leveling agent. The skewness Rsk of the surface of the low refractive index layer is less than 0. The optical laminate has a standard deviation σ of spectral reflectance of less than 0.5 in the wavelength range of 380~780nm, a light reflectance of 0.3~2, and a gloss of less than 50% at 60°.

2. The optical laminate according to claim 1, wherein, The arithmetic mean roughness Ra of the low refractive index layer surface is 0.01~0.5μm, the maximum cross-sectional height Rt of the profile curve is 0.1~1μm, and the average length RSm of the profile curve element is 1~50μm.

3. The optical laminate according to claim 1 or 2, wherein the haze is less than 30% and the total light transmittance is more than 90%.

4. A method for manufacturing an optical laminate, comprising the method of manufacturing the optical laminate according to any one of claims 1 to 3, the method comprising: In the anti-glare layer forming process, the transfer surface of the transfer film is used as a forming mold to form a concave-convex shape on the transfer surface of the anti-glare layer precursor. The concave-convex shape is a shape formed by reversing the transfer surface. as well as The low refractive index layer formation process involves stacking a low refractive index layer on top of the anti-glare layer.

5. A display device comprising the optical laminate according to any one of claims 1 to 3.

6. The display device according to claim 5, wherein it is a liquid crystal display device or an organic EL display.

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