Optical laminate and method for manufacturing optical laminate

Abstract

An optical laminate in which a film-like transparent substrate, a hard coat layer, an adhesion layer, an optical functional layer, and an antifouling layer are laminated in this order, the hard coat layer comprising a binder resin and a cured product of a curable resin composition containing silica particles having an average particle diameter of 100 nm or less, the antifouling layer comprises a vapor-deposited film obtained by vapor-depositing an alkoxysilane compound having a perfluoropolyether group, the adhesion layer has a thickness of 1-10 nm, and the optical functional layer comprises, in order from the adhesion layer side, a high refractive index layer of 5-50 nm, a low refractive index layer of 10-80 nm, a high refractive index layer of 20-200 nm, and a low refractive index layer of 50-200 nm. The antifouling layer has an optical thickness of 3 nm or more and 10 nm or less, the antifouling layer has a surface roughness Ra of 3 nm or more and 9 nm or less, and the residual amount of fluorine atoms in the antifouling layer by XRF after the antifouling layer is washed by irradiation with a fluorine-based solvent for 10 minutes with ultrasonic waves of 40 KHz and 240 W is 70% or more.

Description

[0001] This application is a divisional application of a Chinese patent application with the original application date of March 3, 2021, application number 202180017459.0, and invention title "Optical laminate, article, and method for manufacturing an optical laminate". Technical Field

[0002] The present invention relates to an optical laminate having an antifouling layer on its surface, an article including the optical laminate, and a method for manufacturing the optical laminate.

[0003] This application claims priority based on Japanese Patent Application No. 2020-37146 filed on March 4, 2020, Japanese Patent Application No. 2020-123316 filed on July 17, 2020, Japanese Patent Application No. 2020-151806 filed on September 10, 2020, and Japanese Patent Application No. 2021-32043 filed on March 1, 2021, and incorporates their contents herein. Background Art

[0004] For example, in flat panel displays (FPDs), touch panels, solar cells, etc., as optical laminates, various antireflection films are used to prevent reflection on the surface. Conventionally, as an antireflection film, an antireflection film having a multilayer film in which a high refractive index layer and a low refractive index layer are sequentially laminated on a transparent substrate has been proposed. On the outermost surface of such an antireflection film, an antifouling layer (surface protective layer) is usually formed for the purpose of protecting the surface and preventing fouling.

[0005] In recent years, antireflection films (optical laminates) have been widely used in touch panels of smartphones and various operating devices. Therefore, improvement in the abrasion resistance of the optical laminate has been demanded.

[0006] For example, Patent Document 1 discloses a transparent substrate laminate in which the abrasion resistance is improved by setting the fluorine content in the constituent material of the antifouling layer within a specific range.

[0007] Patent Document 2 describes a method for forming an antifouling layer, in which at least one surface of a substrate to be treated is pretreated before forming the antifouling layer, and the antifouling layer is formed on the pretreated surface. In addition, Patent Document 2 describes that the pretreatment is any one of a high-frequency discharge plasma method, an electron beam method, an ion beam method, an evaporation method, a sputtering method, an alkali treatment method, an acid treatment method, a corona treatment method, and an atmospheric pressure glow discharge plasma method.

[0008] Patent Document 3 describes a method for manufacturing an antifouling optical article, in which an antireflection film is formed on the substrate surface by evaporation, then plasma treatment is performed by introducing oxygen or argon, and then an antifouling layer is formed by vacuum evaporation of a fluorine-containing organosilicon compound.

[0009] Prior Art Documents

[0010] Patent document

[0011] Patent Document 1: International Publication No. 2019 / 078313

[0012] Patent Document 2: Japanese Patent Application Laid-Open No. 2006-175438

[0013] Patent Document 3: Japanese Patent Application Laid-Open No. 2005-301208

[0014] Patent Document 4: Japanese Patent No. 6542970 Summary of the invention

[0015] Problems to be solved by the invention

[0016] However, the transparent substrate laminate described in Patent Document 1 has the following problem: if rubbed repeatedly, the unreacted substances that contribute to wear resistance are wiped off, and high wear resistance cannot be maintained. There is a need for an optical laminate having an antifouling layer that can maintain high wear resistance even against repeated rubbing.

[0017] The present invention has been made in view of the above problems, and an object thereof is to provide an optical laminate having an antifouling layer that can maintain high wear resistance even against repeated rubbing, an article having the optical laminate, and a method for manufacturing the optical laminate.

[0018] Method for solving the problems

[0019] In order to solve the above problems, the present invention proposes the following method.

[0020] (1) The optical laminate according to the first aspect of the present invention is an optical laminate in which a transparent substrate, an adhesion layer, an optical functional layer, and an antifouling layer are laminated in this order. The antifouling layer is composed of a vapor deposition film formed by vapor-depositing an antifouling material, and the residual amount of fluorine atoms in the antifouling layer based on XRF after cleaning with ultrasonic waves of 40 KHz and 240 W for 10 minutes in a fluorine-based solvent is 70% or more.

[0021] (2) The optical laminate according to the second aspect of the present invention is an optical laminate in which a transparent substrate, an adhesion layer, an optical functional layer, and an antifouling layer are laminated in this order. The antifouling layer is composed of a vapor deposition film formed by vapor-depositing an antifouling material, and the hue change ΔE value after contacting with an aqueous sodium hydroxide solution at a liquid temperature of 55 ° C and a concentration of 0.1 mol / L for 4 hours is less than 10.

[0022] (3) The optical laminate of the third mode of the present invention is an optical laminate formed by sequentially laminating a transparent substrate, an adhesion layer, an optical functional layer, and an antifouling layer. The above-mentioned antifouling layer is composed of a vapor deposition film formed by vapor depositing an antifouling material. The above-mentioned antifouling layer has abrasion resistance, and the above-mentioned abrasion resistance is: using a friction tester with steel wool in accordance with JIS L0849, the difference in the contact angle with respect to water before friction and after the steel wool reciprocates horizontally 500 times is 1° or more and 12° or less.

[0023] (4) In the optical laminate of the above mode, the above-mentioned optical functional layer can be any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer.

[0024] (5) In the optical laminate of the above mode, the above-mentioned optical functional layer can include a low refractive index layer.

[0025] (6) In the optical laminate of the above mode, the above-mentioned optical functional layer can be composed of a laminate formed by alternately laminating a low refractive index layer and a high refractive index layer.

[0026] (7) In the optical laminate of the above mode, the above-mentioned antifouling layer can be provided in contact with the above-mentioned low refractive index layer.

[0027] (8) In the optical laminate of the above mode, the above-mentioned adhesion layer can contain an oxide of Si.

[0028] (9) In the optical laminate of the above mode, the above-mentioned adhesion layer and the above-mentioned optical functional layer can be formed by sputtering.

[0029] (10) In the optical laminate of the above mode, the above-mentioned antifouling material can contain a fluorine-based organic compound.

[0030] (11) In the optical laminate of the above mode, a hard coat layer can be further provided between the above-mentioned transparent substrate and the above-mentioned adhesion layer.

[0031] (12) The article of the fourth mode of the present invention includes the optical laminate of the above mode.

[0032] (13) The manufacturing method of the optical laminate of the fifth mode of the present invention is the manufacturing method of the optical laminate of the above mode, which has a glow discharge treatment step of surface-treating the surface of the above-mentioned optical functional layer by glow discharge and an antifouling layer forming step of forming the above-mentioned antifouling layer composed of a vapor deposition film on one side of the above-mentioned optical functional layer. The above-mentioned vapor deposition film is formed by vacuum vapor depositing an antifouling material.

[0033] (14) The manufacturing method of the optical laminate of the above-described manner may have an optical functional layer forming step of forming the above-described optical functional layer by sputtering, and the above-described optical functional layer forming step and the above-described antifouling layer forming step may be continuously performed under reduced pressure.

[0034] Advantages of the Invention

[0035] According to the present invention, there can be provided an optical laminate including an antifouling layer that can maintain high abrasion resistance even against repeated rubbing, an article including the optical laminate, and a method for manufacturing the optical laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a cross-sectional view showing an example of the optical laminate of the present embodiment.

[0037] Figure 2 is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0038] Figure 3 is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0039] Figure 4 is a schematic view showing an example of a manufacturing apparatus for explaining a method for manufacturing the optical laminate of the present embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] Hereinafter, the present embodiment will be described in detail with appropriate reference to the drawings. In the drawings used in the following description, for the sake of easy understanding of the features of the present invention, for convenience, sometimes a part that becomes a feature is enlarged and shown, and the dimensional ratios of the respective components may sometimes be different from the actual ones. The materials, dimensions, etc. exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately changed and implemented within the range in which its effects can be achieved.

[0041] [Optical Laminate]

[0042] Figure 1 is a cross-sectional view for explaining an example of the optical laminate of the present embodiment.

[0043] As Figure 1 shown, the optical laminate 101 of the present embodiment is formed by sequentially laminating a transparent substrate 11, an adhesion layer 13, an optical functional layer 14, and an antifouling layer 15.

[0044] The adhesion layer 13 is a layer that exhibits adhesion.

[0045] The optical functional layer 14 is a layer that exhibits an optical function. The optical function refers to a function of controlling reflection, transmission, and refraction, which are properties of light, and examples thereof include an antireflection function, a selective reflection function, an antiglare function, and a lens function.​​​​

[0046] The optical functional layer 14 is preferably any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer. As the antireflection layer, the selective reflection layer, and the antiglare layer, known antireflection layers, selective reflection layers, and antiglare layers can be used. The antireflection layer, the selective reflection layer, and the antiglare layer can each be a single layer or a multilayer laminate.

[0047] Figure 2 It is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0048] Figure 2 The optical laminate 102 shown is formed by laminating a transparent substrate 11, a hard coat 12, an adhesion layer 13, an optical functional layer 14, and an antifouling layer 15 in this order.

[0049] The adhesion layer 13 is a layer that exhibits adhesion.

[0050] The optical functional layer 14 is a layer that exhibits an optical function. The optical function refers to a function of controlling reflection, transmission, and refraction, which are properties of light, and examples thereof include an antireflection function, a selective reflection function, an antiglare function, and a lens function.

[0051] The optical functional layer 14 is preferably any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer. As the antireflection layer, the selective reflection layer, and the antiglare layer, known antireflection layers, selective reflection layers, and antiglare layers can be used. The antireflection layer, the selective reflection layer, and the antiglare layer can each be a single layer or a multilayer laminate.

[0052] Figure 3 It is a cross-sectional view showing another example of the optical laminate of the present embodiment.

[0053] Figure 3 The optical laminate 101 shown is provided with an antireflection layer as Figure 2 the optical functional layer 14 in the optical laminate 102 shown. As Figure 2 shown, the optical functional layer 14 (antireflection layer) is composed of a laminate in which a low refractive index layer 14b and a high refractive index layer 14a are alternately laminated. Figure 2 The optical functional layer 14 shown is laminated with a hard coat 12, an adhesion layer 13, a high refractive index layer 14a, a low refractive index layer 14b, a high refractive index layer 14a, a low refractive index layer 14b, and an antifouling layer 15 in this order from the transparent substrate 11 side. Therefore, the antifouling layer 15 is in contact with the low refractive index layer 14b of the optical functional layer 14.

[0054] The transparent substrate 11 only needs to be formed of a transparent material that can transmit light in the visible light region. For example, a plastic film is preferably used. Specific examples of the constituent materials of the plastic film include polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, and polyphenylene sulfide resins.

[0055] It should be noted that the "transparent material" referred to in the present invention means a material having a light transmittance of 80% or more in the wavelength region used within the range not impairing the effects of the present invention.

[0056] In addition, in the present embodiment, "(meth)acrylic acid" means methacrylic acid and acrylic acid.

[0057] As long as the optical properties are not significantly impaired, the transparent substrate 11 may also contain a reinforcing material, such as cellulose nanofibers, nano-silica, etc. Polyester resins, acetate resins, polycarbonate resins, and polyolefin resins are particularly preferably used. Specifically, a triacetyl cellulose (TAC) substrate is preferably used.

[0058] In addition, as the inorganic substrate, a glass film may also be used.

[0059] When the plastic film is a TAC substrate, when the hard coat 12 is formed on one side thereof, a penetration layer is formed through which a part of the components constituting the hard coat 12 penetrates. As a result, the adhesion between the transparent substrate 11 and the hard coat 12 becomes good, and the generation of interference fringes caused by the refractive index difference between the layers can be suppressed.

[0060] The transparent substrate 11 may also be a film provided with an optical function and / or a physical function. Examples of the film having an optical function and / or a physical function include a polarizing plate, a retardation compensation film, a heat ray shielding film, a transparent conductive film, a brightness enhancement film, and a barrier property improvement film.

[0061] The thickness of the transparent substrate 11 is not particularly limited. For example, it is preferably 25 μm or more. The film thickness of the transparent substrate 11 is more preferably 40 μm or more.

[0062] If the thickness of the transparent substrate 11 is 25 μm or more, the rigidity of the substrate itself can be ensured, and wrinkles are not easily generated even when stress is applied to the optical laminate 10. In addition, if the thickness of the transparent substrate 11 is 25 μm or more, even when the hard coat 12 is continuously formed on the transparent substrate 11, wrinkles are not easily generated, and there are few concerns in manufacturing, which is preferable. If the thickness of the transparent substrate 11 is 40 μm or more, wrinkles are less likely to be generated, which is preferable.

[0063] In the case of manufacturing using rollers, the thickness of the transparent substrate 11 is preferably 1,000 μm or less, more preferably 600 μm or less. When the thickness of the transparent substrate 11 is 1,000 μm or less, it is easy to wind the optical laminate 10 during manufacturing and the manufactured optical laminate 10 into a roll shape, enabling efficient manufacture of the optical laminate 10. In addition, when the thickness of the transparent substrate 11 is 1,000 μm or less, it is possible to thin and lighten the optical laminate 10. When the thickness of the transparent substrate 11 is 600 μm or less, it is possible to manufacture the optical laminate 10 more efficiently and further thin and lighten it, which is preferable.

[0064] The transparent substrate 11 may be pre-treated with etching treatments such as sputtering, corona discharge, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, etc. and / or a primer treatment on the surface. By performing these treatments in advance, the adhesion to the hard coat 12 formed on the transparent substrate 11 can be improved. In addition, it is also preferable to perform solvent cleaning, ultrasonic cleaning, etc. on the surface of the transparent substrate 11 as needed before forming the hard coat 12 on the transparent substrate 11, thereby removing dust and cleaning the surface of the transparent substrate 11 in advance.

[0065] As the hard coat 12, a known hard coat can be used. The hard coat 12 may be composed only of an adhesive resin, or may contain a filler within a range that does not impair transparency together with the adhesive resin. As the filler, a filler composed of an organic substance, a filler composed of an inorganic substance, or a filler composed of an organic substance and an inorganic substance can be used.

[0066] As the adhesive resin used in the hard coat 12, a transparent adhesive resin is preferable. For example, an ionizing radiation curable resin, a thermoplastic resin, a thermosetting resin, etc., which are resins cured by ultraviolet rays or electron rays, can be used.

[0067] Examples of the ionizing radiation curable resin used in the adhesive resin of the hard coat 12 include ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, styrene, methylstyrene, N-vinylpyrrolidone, etc.

[0068] In addition, examples of the compound of the radiation-curable resin having two or more unsaturated bonds include trimethylolpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, tripentaerythritol octa(meth)acrylate, tetrapentaerythritol deca(meth)acrylate, isocyanuric acid tri(meth)acrylate, isocyanuric acid di(meth)acrylate, polyester tri(meth)acrylate, polyester di(meth)acrylate, bisphenol di(meth)acrylate, diglycerol tetra(meth)acrylate, adamantyl di(meth)acrylate, isobornyl di(meth)acrylate, dicyclopentane di(meth)acrylate, tricyclodecane di(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate and other polyfunctional compounds. Among them, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA) and pentaerythritol tetraacrylate (PETTA) are preferably used. It should be noted that "(meth)acrylate" means methacrylate and acrylate. In addition, as the radiation-curable resin, a resin obtained by modifying the above compound with PO (propylene oxide), EO (ethylene oxide), CL (caprolactone) or the like can also be used.

[0069] Examples of the thermoplastic resin used as the binder resin of the hard coat 12 include styrene resins, (meth)acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins, cellulose derivatives, silicone resins, rubbers or elastomers. The above thermoplastic resin is preferably non-crystalline and soluble in an organic solvent (especially a common solvent capable of dissolving a variety of polymers and curable compounds). In particular, from the viewpoints of transparency and weather resistance, styrene resins, (meth)acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (such as cellulose esters) and the like are preferred.

[0070] Examples of the thermosetting resin used as the binder resin of the hard coat 12 include phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, unsaturated polyester resins, polyurethane resins, epoxy resins, amino alkyd resins, melamine-urea co-condensation resins, silicone resins, polysiloxane resins (including so-called silsesquioxanes such as cage-shaped and ladder-shaped ones) and the like.

[0071] The hard coat 12 may contain an organic resin and an inorganic material, or may be an organic-inorganic hybrid material. As an example, a material formed by the sol-gel method can be cited. As the inorganic material, silica, alumina, zirconia, and titanium dioxide can be cited. As the organic material, for example, an acrylic resin can be cited.

[0072] From the viewpoints of antiglare property, adhesion to the optical functional layer 14 described later, and anti-blocking property, various fillers can be selected for the hard coat 12 according to the use of the optical laminate 10. Specifically, for example, known substances such as silica (oxide of Si) particles, alumina (aluminum oxide) particles, and organic fine particles can be used.

[0073] The hard coat 12 may contain, for example, a binder resin and silica particles and / or alumina particles as fillers. By dispersing silica particles and / or alumina particles as fillers in the hard coat 12, fine irregularities can be formed on the surface of the hard coat 12. These silica particles and / or alumina particles may be exposed on the surface of the hard coat 12 on the side of the optical functional layer 14. In this case, the binder resin of the hard coat 12 is firmly bonded to the optical functional layer 14. Therefore, the adhesion between the hard coat 12 and the optical functional layer 14 is improved, the hardness of the hard coat 12 becomes high, and the scratch resistance of the optical laminate 10 becomes good.

[0074] The average particle diameter of the silica particles and / or alumina particles as fillers of the hard coat 12 is, for example, 800 nm or less, preferably 780 nm or less, and more preferably 100 nm or less.

[0075] From the viewpoint of improving the antiglare property of the optical laminate 10, organic fine particles can be used as the fillers contained in the hard coat 12. As the organic fine particles, for example, an acrylic resin can be cited. The particle diameter of the organic fine particles is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less.

[0076] As the fillers contained in the hard coat 12, various reinforcing materials can be used within a range that does not impair the optical properties in order to impart toughness to the hard coat 12. As the reinforcing materials, for example, cellulose nanofibers can be cited.

[0077] The thickness of the hard coat 12 is not particularly limited, and is preferably 0.5 μm or more, more preferably 1 μm or more. The thickness of the hard coat 12 is preferably 100 μm or less. When the thickness of the hard coat 12 is 0.5 μm or more, sufficient hardness can be obtained, so that scratches in manufacturing are difficult to occur. In addition, when the thickness of the hard coat 12 is 100 μm or less, thinning and weight reduction of the optical laminate 10 can be achieved. Further, when the thickness of the hard coat 12 is 100 μm or less, microcracks of the hard coat 12 generated when the optical laminate 10 is bent during manufacturing are difficult to occur, and the productivity becomes good.

[0078] The hard coat 12 may be a single layer or a layer formed by laminating a plurality of layers. Further, known functions such as ultraviolet absorption performance, antistatic performance, refractive index adjustment function, and hardness adjustment function may be imparted to the hard coat 12.

[0079] In addition, the functions imparted to the hard coat 12 may be imparted to a single hard coat or may be divided into a plurality of layers and imparted.

[0080] The adhesion layer 13 is a layer formed to improve the adhesion between the transparent substrate 11 or the hard coat 12, which is an organic film, and the optical functional layer 14, which is an inorganic film. Figure 3 In the optical laminate 10 shown, an adhesion layer 13 is provided between the hard coat 12 and the optical functional layer 14. The adhesion layer 13 has a function of adhering the hard coat 12 and the optical functional layer 14. The adhesion layer 13 is preferably composed of a metal oxide or a metal in an oxygen-deficient state. The metal oxide in an oxygen-deficient state means a metal oxide in a state where the number of oxygen atoms is insufficient compared to the stoichiometric composition. Examples of the metal oxide in an oxygen-deficient state include SiOx, ALOx, TiOx, ZrOx, CeOx, MgOx, ZnOx, TaOx, SbOx, SnOx, MnOx, etc. In addition, examples of the metal include Si, Al, Ti, Zr, Ce, Mg, Zn, Ta, Sb, Sn, Mn, In, etc. The adhesion layer 13 may be, for example, a layer in which x in SiOx is greater than 0 and less than 2.0. In addition, the adhesion layer may be formed of a mixture of a plurality of metals or metal oxides.

[0081] From the viewpoints of maintaining transparency and adhesion to the optical functional layer and obtaining good optical characteristics, the thickness of the adhesion layer is preferably more than 0 nm and 20 nm or less, and particularly preferably 1 nm or more and 10 nm or less.

[0082] The optical functional layer 14 is a laminate that exhibits an antireflection function. Figure 3The optical functional layer 14 shown is a laminate of a total of four layers in which a high refractive index layer 14a and a low refractive index layer 14b are alternately laminated in order from the adhesion layer 13 side. The number of layers of the high refractive index layer 14a and the low refractive index layer 14b is not particularly limited, and the number of layers of the high refractive index layer 14a and the low refractive index layer 14b can be set to any number of layers.

[0083] In Figure 3 In the optical laminate 10 shown, the optical functional layer 14 is composed of a laminate in which a low refractive index layer 14b and a high refractive index layer 14a are alternately laminated. Therefore, the light incident from the antifouling layer 15 side is diffused by the optical functional layer 14. Therefore, an antireflection function for preventing the light incident from the antifouling layer 15 side from being reflected in one direction can be obtained.

[0084] From the viewpoints of ease of acquisition and cost, the low refractive index layer 14b preferably contains an oxide of Si, and is preferably a layer mainly composed of SiO 2 (oxide of Si), etc. SiO 2 The single-layer film is colorless and transparent. In the present embodiment, the main component of the low refractive index layer 14b means a component contained in the low refractive index layer 14b in an amount of 50% by mass or more.

[0085] When the low refractive index layer 14b is a layer mainly composed of an oxide of Si, other elements in an amount less than 50% by mass may also be contained. The content of other elements other than the oxide of Si is preferably 10% or less. As other elements, for example, Na may be contained for the purpose of improving durability, and Zr, Al or N may be contained for the purpose of improving hardness, and Zr or Al may be contained for the purpose of improving alkali resistance.

[0086] The refractive index of the low refractive index layer 14b is preferably 1.20 to 1.60, more preferably 1.30 to 1.50. As the dielectric used for the low refractive index layer 14b, magnesium fluoride (MgF 2 , refractive index 1.38), etc. can be cited.

[0087] The refractive index of the high refractive index layer 14a is preferably 2.00 to 2.60, more preferably 2.10 to 2.45. As the dielectric used for the high refractive index layer 14a, niobium pentoxide (Nb 2 O 5 , refractive index 2.33), titanium oxide (TiO 2 , refractive index 2.33 to 2.55), tungsten oxide (WO 3 , refractive index 2.2), cerium oxide (CeO 2 , refractive index 2.2), tantalum pentoxide (Ta 2 O 5, refractive index 2.16), zinc oxide (ZnO, refractive index 2.1), indium tin oxide (ITO, refractive index 2.06), zirconium oxide (ZrO 2 , refractive index 2.2), etc.

[0088] When it is desired to impart electrical conductivity to the high refractive index layer 14a, for example, ITO or indium zinc oxide (IZO) can be selected.

[0089] The optical functional layer 14 is preferably formed, for example, of a layer composed of niobium pentoxide (Nb 2 O 5 , refractive index 2.33) as the high refractive index layer 14a, and a layer composed of SiO 2 as the low refractive index layer 14b.

[0090] The film thickness of the low refractive index layer 14b only needs to be in the range of 1 nm or more and 200 nm or less, and can be appropriately selected according to the wavelength region of the antireflection function required.

[0091] The film thickness of the high refractive index layer 14a is, for example, 1 nm or more and 200 nm or less, and can be appropriately selected according to the wavelength region of the antireflection function required.

[0092] The film thicknesses of the high refractive index layer 14a and the low refractive index layer 14b can be appropriately selected according to the design of the optical functional layer 14, respectively.

[0093] For example, starting from the adhesion layer 13 side, it can be successively a high refractive index layer 14a of 5 to 50 nm, a low refractive index layer 14b of 10 to 80 nm, a high refractive index layer 14a of 20 to 200 nm, and a low refractive index layer 14b of 50 to 200 nm.

[0094] The low refractive index layer 14b is disposed on the antifouling layer 15 side in the layer forming the optical functional layer 14. When the low refractive index layer 14b of the optical functional layer 14 is in contact with the antifouling layer 15, the antireflection performance of the optical functional layer 14 becomes good, and thus it is preferred.

[0095] The antifouling layer 15 is formed on the outermost surface of the optical functional layer 14 to prevent the optical functional layer 14 from being soiled. In addition, when the antifouling layer 15 is applied to a touch panel or the like, the loss of the optical functional layer 14 is suppressed by the abrasion resistance.

[0096] The antifouling layer 15 of the present embodiment is composed of a vapor deposition film formed by vapor depositing an antifouling material. In the present embodiment, the antifouling layer 15 is formed by vacuum vapor depositing a fluorine-based organic compound as the antifouling material on one surface of the low refractive index layer 14b constituting the optical functional layer 14. In the present embodiment, since the antifouling material contains a fluorine-based organic compound, the optical laminate 10 has better abrasion resistance and alkali resistance.

[0097] As the fluorine-based organic compound constituting the antifouling layer 15, a compound containing a fluorine-modified organic group and a reactive silyl group (such as alkoxysilane) is preferably used. As commercially available products, OPTOOL DSX (manufactured by Daikin Industries, Ltd.), KY-100 series (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be cited.

[0098] As the fluorine-based organic compound constituting the antifouling layer 15, as the fluorine-based organic compound, a compound composed of a fluorine-modified organic group and a reactive silyl group (such as alkoxysilane) is used. As the low-refractive-index layer 14b of the optical functional layer 14 in contact with the antifouling layer 15, a layer composed of SiO 2 In the case of a layer composed of, a siloxane bond is formed between the silanol group in the skeleton of the fluorine-based organic compound and SiO 2 Therefore, the adhesiveness between the optical functional layer 14 and the antifouling layer 15 becomes good, which is preferable.

[0099] The optical thickness of the antifouling layer 15 only needs to be in the range of 1 nm or more and 20 nm or less, and is preferably in the range of 3 nm or more and 10 nm or less. If the thickness of the antifouling layer 15 is 1 nm or more, when the optical laminate 10 is applied to touch panel applications and the like, sufficient abrasion resistance can be ensured. In addition, when the thickness of the antifouling layer 15 is 20 nm or less, the time required for evaporation coating can be a short time, and it can be manufactured efficiently.

[0100] The surface roughness Ra of the antifouling layer 15 varies depending on the use and configuration of the optical laminate. For example, when it is a transparent antireflection layer without an antiglare function, it is preferably 3 nm or more. The upper limit is not particularly limited. For example, from the viewpoint of scratch resistance, it is preferably 9 nm or less.

[0101] The antifouling layer 15 can contain additives such as light stabilizers, ultraviolet absorbers, colorants, antistatic agents, lubricants, leveling agents, defoaming agents, antioxidants, flame retardants, infrared absorbers, and surfactants as needed.

[0102] The antifouling layer 15 formed by evaporation coating is firmly bonded to the optical functional layer 14, with few voids and dense. Thus, the antifouling layer 15 of the present embodiment exhibits different characteristics from the antifouling layers formed by conventional methods such as coating with antifouling materials.

[0103] For example, the antifouling layer 15 of the optical laminate 10 of the present embodiment has the following characteristics.

[0104] (1) The contact angle difference with respect to water after a scratch test performed by horizontally reciprocating steel wool 500 times is 10° or less.

[0105] (2) The contact angle with respect to water after the abrasion test performed by horizontally reciprocating the steel wool 500 times is 110° or more.

[0106] (3) The contact angle with respect to water after the abrasion test performed by reciprocating the wiping cloth (non-woven fabric wiping material) 4000 times is 100° or more.

[0107] (4) The change amount (ΔE value) of the L*a*b* values shown in the following formula (2) of SCI (Specular Component Include (including specular regular reflection light), a measurement method considering the reflection color of the regular reflection light) before and after the abrasion test performed by horizontally reciprocating the steel wool 500 times is 3.0 or less.

[0108] [Equation 1]

[0109]

[0110] In formula (2), L0*, a0*, b0* are the values before the abrasion test, and L1*, a1*, b1* are the values after the abrasion test.

[0111] (5) The change amount (ΔE value) of the L*a*b* values shown in the following formula (3) of SCE (Specular Component Exclude (excluding specular regular reflection light), a measurement method not considering the reflection color of the regular reflection light) before and after the abrasion test performed by horizontally reciprocating the steel wool 500 times is 1.5 or less.

[0112] [Equation 2]

[0113]

[0114] In formula (3), L0*, a0*, b0* are the values before the abrasion test, and L1*, a1*, b1* are the values after the abrasion test.

[0115] (6) The fluorine residue rate measured by fluorescence X-ray analysis method (XRF) after immersing in a 0.1 mol / L NaOH solution (liquid temperature 55°C) for 4 hours is 70% or more.

[0116] The optical laminate 10 having the antifouling layer 15 formed by vapor deposition of the present embodiment has fewer voids and is formed densely compared with the antifouling layer formed by coating. In addition, in the optical laminate 10 of the present embodiment, the antifouling layer 15 is firmly bonded to the low refractive index layer 14b in contact with the antifouling layer 15. Therefore, the visible light transmittance of the optical laminate 10 of the present embodiment is excellent, and it can maintain high abrasion resistance for repeated friction and can also maintain high resistance to alkalinity.

[0117] [Method for manufacturing an optical laminate]

[0118] Figure 3 The optical laminate 10 of the present embodiment shown, for example, can be manufactured by the method shown below.

[0119] In the present embodiment, as an example of the method for manufacturing the optical laminate 10, the case of manufacturing the optical laminate 10 using a transparent substrate 11 wound into a roll will be described.

[0120] First, unwind the transparent substrate 11 wound into a roll. Then, apply a slurry containing a material that becomes the hard coat 12 onto the transparent substrate 11 by a known method, and cure it by a known method corresponding to the material that becomes the hard coat 12. Thereby, the hard coat 12 is formed (hard coat forming step). Then, the transparent substrate 11 having the hard coat 12 formed on its surface is wound into a roll by a known method.

[0121] Next, a bonding layer forming step of forming a bonding layer 13 on the hard coat 12 and an optical functional layer forming step of forming an optical functional layer 14 are performed. Then, an antifouling layer forming step of forming an antifouling layer 15 on the optical functional layer 14 is performed. In the present embodiment, it is preferable to perform a first surface treatment step of treating the surface of the hard coat 12 before the optical functional layer forming step, and then perform the bonding layer forming step and the optical functional layer forming step. Further, in the present embodiment, it is preferable to perform a second surface treatment step of treating the surface of the antireflection film after the optical functional layer forming step, and then perform the antifouling layer forming step.

[0122] In the method for manufacturing the optical laminate 10 of the present embodiment, the first surface treatment step, the bonding layer forming step, the optical functional layer forming step, the second surface treatment step, and the antifouling layer forming step are preferably continuously performed while maintaining the optical laminate during manufacturing under a reduced pressure state. When continuously performing the first surface treatment step, the bonding layer forming step, the optical functional layer forming step, the second surface treatment step, and the antifouling layer forming step while maintaining the optical laminate during manufacturing under a reduced pressure state, for example, as a sputtering device, a device having a thin film forming device described in Patent Document 4 can be used.

[0123] As a manufacturing apparatus that can be used in the method for manufacturing the optical laminate of the present embodiment, specifically, Figure 4 the manufacturing apparatus 20 shown can be cited.

[0124] Figure 4 The manufacturing apparatus 20 shown includes a roll unwinding device 4, a pretreatment device 2A, a sputtering device 1, a pretreatment device 2B, an evaporation device 3, and a roll winding device 5. AsFigure 4 As shown, these devices 4, 2A, 1, 2B, 3, 5 are connected in sequence. Figure 4 The manufacturing device 20 shown is a roll-to-roll manufacturing device as follows: unwind the substrate from the roll and make it continuously pass through the connected devices (in Figure 4 it is the pretreatment device 2A, sputtering device 1, pretreatment device 2B, evaporation device 3), and then wind it up, thereby continuously forming multiple layers on the substrate.

[0125] When manufacturing the optical laminate 10 using a roll-to-roll manufacturing device, the conveying speed (linear speed) of the optical laminate 10 during manufacturing can be set appropriately. The conveying speed is preferably 0.5 - 20 m / min, more preferably 0.5 - 10 m / min.

[0126] <Roll unwind device>

[0127] Figure 4 The roll unwind device 4 shown has a chamber 34 with a specified reduced-pressure atmosphere inside, one or more vacuum pumps 21 (one in Figure 4 it) for discharging the gas inside the chamber 34 to form a reduced-pressure atmosphere, and an unwind roll 23 and a guide roll 22 provided inside the chamber 34. As Figure 4 shown, the chamber 34 is connected to the chamber 31 of the sputtering device 1.

[0128] A transparent substrate 11 with a hard coat 12 formed on its surface is wound around the unwind roll 23. The unwind roll 23 supplies the transparent substrate 11 with the hard coat 12 formed on its surface to the pretreatment device 2A at a specified conveying speed.

[0129] <Pretreatment device 2A>

[0130] Figure 4 The pretreatment device 2A shown has a chamber 32 with a specified reduced-pressure atmosphere inside, a cylinder roll 26, multiple ( Figure 4 two in it) guide rolls 22, and a plasma discharge device 42. As Figure 4 shown, the cylinder roll 26, guide rolls 22, and plasma discharge device 42 are provided inside the chamber 32. As Figure 4 shown, the chamber 32 is connected to the chamber 31 of the sputtering device 1.

[0131] The cylinder roll 26 and the guide rolls 22 convey the transparent substrate 11 with the hard coat 12 formed on its surface sent from the roll unwind device 4 at a specified conveying speed, and send out the transparent substrate 11 with the surface of the hard coat 12 treated to the sputtering device 1.

[0132] As Figure 4As shown, the plasma discharge device 42 is disposed opposite to the outer peripheral surface of the cylindrical roller 26 with a predetermined gap therebetween. The plasma discharge device 42 ionizes a gas by glow discharge. As the gas, a gas that is inexpensive, inert, and does not affect optical properties is preferred. For example, argon, oxygen, nitrogen, helium, etc. can be used. As the gas, argon is preferred because it has a large mass, is chemically stable, and is easily available.

[0133] In the present embodiment, as the plasma discharge device 42, a glow discharge device that ionizes argon using high-frequency plasma is preferably used.

[0134] <Sputtering device>

[0135] Figure 4 The sputtering device 1 shown has a chamber 31 with a predetermined reduced-pressure atmosphere inside, one or more vacuum pumps 21 (two in Figure 4 ) that discharge the gas inside the chamber 31 to create a reduced-pressure atmosphere, a film-forming roller 25, a plurality of (two in Figure 4 ) guide rollers 22, and a plurality of (four in the example shown in Figure 4 ) film-forming parts 41. As shown in Figure 4 the film-forming roller 25, the guide rollers 22, and the film-forming parts 41 are provided inside the chamber 31. As shown in Figure 4 the chamber 31 is connected to the chamber 32 of the pretreatment device 2B.

[0136] The film-forming roller 25 and the guide rollers 22 convey the transparent substrate 11 formed with the surface-treated hard coating 12 sent from the pretreatment device 2A at a predetermined conveying speed, and supply the transparent substrate 11 on which the adhesion layer 13 and the optical functional layer 14 are formed on the hard coating 12 to the pretreatment device 2B.

[0137] In Figure 4 the sputtering device 1 shown, on the hard coating 12 of the transparent substrate 11 moving on the film-forming roller 25, the adhesion layer 13 is laminated by sputtering, and the high refractive index layer 14a and the low refractive index layer 14b are alternately laminated thereon to form the optical functional layer 14.

[0138] As shown in Figure 4As shown, the film forming section 41 is disposed opposite to the outer peripheral surface of the film forming roller 25 with a predetermined interval therebetween, and a plurality of film forming sections 41 are provided so as to surround the film forming roller 25. The number of film forming sections 41 is determined according to the total number of stacked layers of the adhesion layer 13, the high refractive index layer 14a and the low refractive index layer 14b that form the optical functional layer 14. When it is difficult to ensure the distance between adjacent film forming sections 41 due to the large total number of stacked layers of the adhesion layer 13 and the high refractive index layer 14a and the low refractive index layer 14b that form the optical functional layer 14, a plurality of film forming rollers 25 may be provided in the chamber 31, and the film forming sections 41 may be disposed around each film forming roller 25. When a plurality of film forming rollers 25 are provided, a guide roller 22 may be further provided as needed. Chambers 31 provided with film forming rollers 25 and film forming sections 41 may be connected. In addition, in order to easily ensure the distance between adjacent film forming sections 41, the diameter of the film forming roller 25 may be appropriately changed.

[0139] A predetermined target (not shown) is provided in each film forming section 41. A voltage is applied to the target by a known structure. In the present embodiment, a gas supply section (not shown) for supplying a predetermined reactive gas and a carrier gas to the target at a predetermined flow rate and a known magnetic field generation source (not shown) for forming a magnetic field on the surface of the target are provided near the target.

[0140] The type and flow rate of the target material and the reactive gas are appropriately determined according to the composition of the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b formed on the transparent substrate 11 through between the film forming section 41 and the film forming roller 25. For example, when forming a layer composed of SiO 2 , Si is used as the target and O 2 is used as the reactive gas. In addition, for example, when forming a layer composed of Nb 2 O 5 , Nb is used as the target and O 2 is used as the reactive gas.

[0141] In the present embodiment, from the viewpoint of increasing the film forming speed, as the sputtering method, a magnetron sputtering method is preferably used.

[0142] It should be noted that the sputtering method is not limited to the magnetron sputtering method, and a bipolar sputtering method using plasma generated by DC glow discharge or high frequency, a three-pole sputtering method with a heated cathode, etc. may also be used.

[0143] The sputtering apparatus 1 includes an optical monitor (not shown) as a measurement unit for measuring the optical characteristics after forming each layer that will become the adhesion layer 13 and the optical functional layer 14. Thereby, the quality of the formed adhesion layer 13 and optical functional layer 14 can be confirmed. When the sputtering apparatus 1 has two or more chambers, for example, it is preferable to provide an optical monitor in each chamber.

[0144] As an optical monitor (not shown), for example, an optical monitor that measures the optical characteristics in the width direction of the adhesion layer 13 and the optical functional layer 14 formed on the hard coat 12 using an optical head capable of scanning in the width direction can be cited. In the case of having such an optical monitor, for example, by measuring the peak wavelength of the reflectance as an optical characteristic and converting it into an optical thickness, the optical thickness distribution in the width direction of the adhesion layer 13 and the optical functional layer 14 can be measured. By measuring the optical characteristics using the optical monitor, the sputtering conditions can be adjusted in real time, and the optical laminate 10 having the adhesion layer 13 and the optical functional layer 14 with optimal optical characteristics can be formed.

[0145] <Pretreatment device 2B>

[0146] Figure 4 The shown pretreatment device 2B has a chamber 32 with a prescribed reduced-pressure atmosphere inside, a cylinder roll 26, a plurality of ( Figure 4 in this case, 2) guide rolls 22, and a plasma discharge device 42. As Figure 4 shown, the cylinder roll 26, the guide rolls 22, and the plasma discharge device 42 are provided inside the chamber 32. As Figure 4 shown, the chamber 32 is connected to the chamber 33 of the evaporation device 3.

[0147] The cylinder roll 26 and the guide rolls 22 convey the transparent substrate 11 having the respective layers formed up to the optical functional layer 14, which is conveyed from the sputtering device 1, at a prescribed conveyance speed, and send out the transparent substrate 11 whose surface of the optical functional layer 14 has been treated to the evaporation device 3.

[0148] As the plasma discharge device 42, for example, the same device as the pretreatment device 2A can be used.

[0149] <Evaporation device>

[0150] Figure 4 The shown evaporation device 3 has a chamber 33 with a prescribed reduced-pressure atmosphere inside, one or more vacuum pumps 21 (in Figure 4 this case, 1) that discharge the gas inside the chamber 33 to create a reduced-pressure atmosphere, a plurality of (in Figure 4 this case, 4) guide rolls 22, an evaporation source 43, and a heating device 53. As Figure 4 shown, the guide rolls 22 and the evaporation source 43 are provided inside the chamber 33. The chamber 33 is connected to the chamber 35 of the roll curling device 5.

[0151] The evaporation source 43 is disposed opposite to the transparent substrate 11 whose surface of the optical functional layer 14 has been treated and is conveyed substantially horizontally between two adjacent guide rolls 22. The evaporation source 43 supplies evaporation gas composed of the material that becomes the antifouling layer 15 onto the optical functional layer 14. The orientation of the evaporation source 43 can be set arbitrarily.

[0152] The heating device 53 heats the material for the antifouling layer 15 to the vapor pressure temperature. As the heating device 53, a device that heats by means of resistance heating, heater heating, induction heating, electron beam method, etc. can be used. In the resistance heating method, the container that houses the antifouling material for the antifouling layer 15 is used as a resistor and energized for heating. In the heater heating method, the container is heated by a heater disposed on the outer periphery of the container. In the induction heating method, the container or the antifouling material is heated from an induction coil provided outside through electromagnetic induction.

[0153] Figure 4 The vapor deposition apparatus 3 shown includes a guide plate (not shown) that guides the vapor deposition material evaporated from the vapor deposition source 43 to a specified position, a film thickness meter (not shown) that observes the thickness of the antifouling layer 15 formed by vapor deposition, a vacuum pressure gauge (not shown) that measures the pressure inside the chamber 33, and a power supply device (not shown).

[0154] The guide plate can be of any shape as long as it can guide the evaporated vapor deposition material to the desired position. The guide plate may not be provided if it is not necessary.

[0155] As the vacuum pressure gauge, for example, an ion gauge or the like can be used.

[0156] As the power supply device, for example, a high-frequency power supply or the like can be cited.

[0157] <Roll curling device>

[0158] Figure 4 The roll curling device 5 shown has a chamber 35 with a specified reduced-pressure atmosphere inside, one or more vacuum pumps 21 (one in Figure 4 this case) that discharge the gas inside the chamber 35 to create a reduced-pressure atmosphere, and a curling roll 24 and a guide roll 22 disposed inside the chamber 35.

[0159] A transparent substrate 11 (optical laminate 10) having each layer formed up to the antifouling layer 15 on its surface is wound around the curling roll 24. The curling roll 24 and the guide roll 22 curl the optical laminate 10 at a specified curling speed.

[0160] As needed, a carrier film can also be used.

[0161] As Figure 4 The vacuum pump 21 included in the manufacturing apparatus 20 shown can, for example, be a dry pump, an oil rotary pump, a turbo molecular pump, an oil diffusion pump, a cryopump, a sputter ion pump, a getter pump, etc. The vacuum pump 21 can be appropriately selected or used in combination in each of the chambers 31, 32, 33, 34, 35 to create the desired reduced-pressure state.

[0162] The vacuum pump 21 only needs to be able to maintain both the chamber 31 of the sputtering device 1 and the chamber 33 of the vapor deposition device 3 in the desired reduced pressure state, and there are no particular limitations on the installation position and number of the vacuum pumps 21 in the manufacturing device 20. In addition, in Figure 4 In the manufacturing device 20 shown, the roll unwinding device 4, the pretreatment device 2A, the sputtering device 1, the pretreatment device 2B, the vapor deposition device 3, and the roll winding device 5 are connected. Therefore, the vacuum pumps 21 can be respectively installed in the chambers 31, 32, 33, 34, 35, and can also be installed only in a part of the chambers 31, 32, 33, 34, 35 as long as both the chamber 31 of the sputtering device 1 and the chamber 33 of the vapor deposition device 3 can be maintained in the desired reduced pressure state.

[0163] Next, a method of continuously performing the first surface treatment process, the adhesion layer formation process, the optical functional layer formation process, the second surface treatment process, and the antifouling layer formation process while maintaining the optical laminate 10 being manufactured in a reduced pressure state using the Figure 4 manufacturing device 20 shown will be described.

[0164] First, in the chamber 34 of the roll unwinding device 4, a unwind roll 23 around which a transparent substrate 11 having a hard coat 12 formed on its surface is wound is provided. Then, the unwind roll 23 and the guide roll 22 are rotated, and the transparent substrate 11 having the hard coat 12 formed on its surface is sent to the pretreatment device 2A at a predetermined conveyance speed.

[0165] Next, in the chamber 32 of the pretreatment device 2A, as a pretreatment for the surface on which the adhesion layer 13 and the optical functional layer 14 are formed, the first surface treatment process is performed. In the present embodiment, the first surface treatment process is performed on the transparent substrate 11 having the hard coat 12 formed thereon.

[0166] In the first surface treatment process, the cylinder roll 26 and the guide roll 22 are rotated, and while the transparent substrate 11 having the hard coat 12 formed thereon is conveyed at a predetermined conveyance speed, the surface of the hard coat 12 traveling on the cylinder roll 26 is treated.

[0167] As a surface treatment method for the hard coat 12, for example, glow discharge treatment, plasma treatment, ion etching, alkali treatment, etc. can be used. Among them, glow discharge treatment is preferably used because it can perform large-area treatment. The glow discharge treatment can be performed, for example, at a treatment intensity of 0.1 to 10 kwh.

[0168] By performing glow discharge treatment on the surface of the hard coat 12, the surface of the hard coat 12 is roughened at the nanometer level, and substances with weak binding force present on the surface of the hard coat 12 are removed. As a result, the adhesion between the hard coat 12 and the optical functional layer 14 formed on the hard coat 12 becomes good.

[0169] Next, an adhesion layer forming step and an optical functional layer forming step are performed in the chamber 31 of the sputtering apparatus 1. Specifically, the film forming roller 25 and the guide roller 22 are rotated, and while the transparent substrate 11 having the hard coat layer 12 formed thereon is conveyed at a predetermined conveyance speed, the adhesion layer 13 and the optical functional layer 14 are formed on the hard coat layer 12 that moves on the film forming roller 25.

[0170] In the present embodiment, the adhesion layer 13 is formed by changing the material of the target provided in each film forming section 41 or the type and flow rate of the reactive gas supplied from the gas supply section and performing sputtering, and the high refractive index layer 14a and the low refractive index layer 14b are alternately laminated thereon. That is, the adhesion layer forming step and the optical functional layer forming step are continuously performed in the sputtering apparatus 1. Thereby, the adhesion layer 13 and the optical functional layer 14 as an antireflection layer are formed.

[0171] When forming the SiOx film as the adhesion layer 13, it is preferable to use a silicon target and form it by reactive sputtering using a mixed gas atmosphere of oxygen and argon.

[0172] When continuously laminating the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b by sputtering, it is also possible to change the material of the target during the film formation of the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b to perform film formation. In addition, for example, it is also possible to use one material as the target and alternately form a layer composed of the target material and a layer composed of an oxide of the target material as the adhesion layer 13, the high refractive index layer 14a, and the low refractive index layer 14b by changing the oxygen (reactive gas) flow rate during sputtering.

[0173] The pressure during sputtering for forming the adhesion layer 13 and the optical functional layer 14 varies depending on the sputtered metal, and can be 2 Pa or less, preferably 1 Pa or less, more preferably 0.6 Pa or less, and particularly preferably 0.2 Pa or less. If the pressure during sputtering is in a reduced pressure state of 1 Pa or less, the mean free path of the film forming molecules becomes longer, and the energy of the film forming molecules is laminated in a higher state, so that a dense and better film quality is obtained.

[0174] Then, by the rotation of the film forming roller 25 and the guide roller 22, the transparent substrate 11 having the adhesion layer 13 and the optical functional layer 14 formed thereon is sent out to the pretreatment apparatus 2B.

[0175] Next, in the chamber 32 of the pretreatment apparatus 2B, as a pretreatment of the surface for forming the antifouling layer 15, a second surface treatment step is performed. In the present embodiment, the transparent substrate 11 having the optical functional layer 14 formed by the optical functional layer forming step is not brought into contact with the atmosphere, and the second surface treatment step is continuously performed while maintaining the reduced pressure state.

[0176] In the second surface treatment step, while rotating the cylinder roller 26 and the guide roller 22 and conveying the transparent substrate 11 formed with each layer up to the optical functional layer 14 at a prescribed conveying speed, a discharge treatment is performed on the surface of the optical functional layer 14 traveling on the cylinder roller 26.

[0177] As a surface treatment method for the optical functional layer 14, for example, glow discharge treatment, plasma treatment, ion etching, alkali treatment, etc. can be used. Among them, glow discharge treatment is preferably used because large-area treatment can be performed.

[0178] When a discharge treatment is performed on the surface of the optical functional layer 14, the surface of the optical functional layer 14 is etched and the surface roughness of the optical functional layer 14 changes. The surface roughness Ra of the optical functional layer 14 can be controlled by setting the cumulative output during the discharge treatment within an appropriate range. In the present embodiment, the cumulative output refers to a value obtained by dividing the product of the glow discharge output irradiated on the optical functional layer 14 and the irradiation time during the discharge treatment by the unit area.

[0179] The conditions of the discharge treatment can be set appropriately. By appropriately setting the conditions of the discharge treatment, the adhesion between the optical functional layer 14 and the antifouling layer 15 formed thereon becomes good, and an optical laminate 10 with better abrasion resistance and alkali resistance can be obtained.

[0180] The surface roughness Ra of the optical functional layer 14 after the discharge treatment varies depending on the surface roughness of the hard coat 12 provided under the optical functional layer 14.

[0181] In addition, the surface roughness Ra of the optical functional layer 14 after the discharge treatment affects the surface roughness Ra of the antifouling layer 15 formed on the optical functional layer 14.

[0182] In the second surface treatment step, for example, the surface of the optical functional layer can be treated such that the change rate of the surface roughness shown by the following (Equation 1) is 1 to 25%.

[0183] Change rate of surface roughness (%) = ((Ra2 / Ra1) - 1) × 100 (%)... Equation (1)

[0184] In Equation (1), Ra1 represents the surface roughness (Ra) of the optical functional layer before treating the surface, and Ra2 represents the surface roughness (Ra) of the optical functional layer after treating the surface.

[0185] The second surface treatment step is preferably carried out in such a manner that the change rate of the surface roughness represented by (Formula 1) is 1% to 25%, more preferably 10% to 20%. When the change rate of the surface roughness represented by (Formula 1) is 1% or more, the effect of improving the adhesion between the optical functional layer 14 and the antifouling layer 15 brought about by carrying out the second surface treatment step becomes significant. In addition, if the change rate of the surface roughness represented by (Formula 1) is 25% or less, the thickness of the optical functional layer 14 is appropriate, so that an antifouling layer 15 with a uniform thickness is formed on the optical functional layer 14.

[0186] In the present embodiment, the surface roughness Ra of the surface of the optical functional layer 14 can be measured by the method shown below. Using an atomic force microscope (AFM: Atomic Force Microscope), measure the surface roughness Ra within the range of the surface area of 1 μm of the surface of the optical functional layer 14. 2 of the surface.

[0187] Then, by the rotation of the cylinder roller 26 and the guide roller 22, the transparent substrate 11 with the surface of the optical functional layer 14 treated is sent out to the evaporation device 3.

[0188] Next, an antifouling layer forming step is carried out in the chamber 33 of the evaporation device 3. In the present embodiment, the transparent substrate 11 with the surface of the optical functional layer 14 treated by the second surface treatment step is not brought into contact with the atmosphere, and the antifouling layer forming step is continuously carried out while maintaining the reduced pressure state. In the antifouling layer forming step, the guide roller 22 is rotated, and while the transparent substrate 11 with the surface of the optical functional layer 14 treated is conveyed at a predetermined conveying speed, the evaporation source 43 is evaporated on the surface of the optical functional layer 14.

[0189] In the present embodiment, for example, the antifouling material containing a fluorine-based organic compound that becomes the antifouling layer 15 is heated to the vapor pressure temperature by the heating device 53, and the obtained evaporation gas is supplied from the evaporation source 43 in a reduced pressure environment and attached to the surface-treated optical functional layer 14, and the antifouling layer 15 is formed by vacuum evaporation.

[0190] The pressure during the vacuum evaporation of the antifouling layer 15 is preferably 0.05 Pa or less, more preferably 0.01 Pa or less, and particularly preferably 0.001 Pa or less. If the pressure during the vacuum evaporation is in a reduced pressure state of 0.05 Pa or less, the mean free path of the film-forming molecules becomes longer and the evaporation energy becomes higher, so that a dense and better antifouling layer 15 can be obtained.

[0191] Through the above method, an optical laminate 10 is obtained in which an antifouling layer 15 is formed by vacuum evaporation on the adhesion layer 13 and the optical functional layer 14 formed by sputtering.

[0192] Then, by the rotation of the guide roller 22, the transparent substrate 11 (optical laminate 10) having the layers up to the antifouling layer 15 formed thereon is sent to the roll winding device 5.

[0193] Then, in the chamber 35 of the roll winding device 5, the optical laminate 10 is wound around the winding roll 24 by the rotation of the winding roll 24 and the guide roller 22.

[0194] In the present embodiment, it is preferable to continuously perform the optical functional layer forming step and the antifouling layer forming step under reduced pressure. In particular, as in the manufacturing method of the present embodiment using the manufacturing apparatus 20 shown Figure 4 when the optical laminate 10 is continuously manufactured as a wound body in a roll-to-roll manner, it is more preferable to continuously perform the optical functional layer forming step and the antifouling layer forming step online while maintaining the reduced pressure state. The term "online" means performing the antifouling layer forming step without bringing the optical functional layer 14 formed in the optical functional layer forming step into contact with the atmosphere. By continuously performing the optical functional layer forming step and the antifouling layer forming step under reduced pressure, before forming the antifouling layer 15, generation of a natural oxide film on the optical functional layer 14 formed in the optical functional layer forming step can be suppressed. In addition, it is possible to prevent contaminants such as foreign matters from adhering to the optical functional layer 14 when the roll is wound and hindering the adhesion between the optical functional layer 14 and the antifouling layer 15. Therefore, compared with the case where the transparent substrate 11 having the layers up to the optical functional layer 14 formed thereon is taken out from the chamber under reduced pressure after the optical functional layer forming step, and then is set again in the chamber and the antifouling layer forming step is performed under reduced pressure (the case of Example 4 described later), an optical laminate having good adhesion between the optical functional layer 14 and the antifouling layer 15 and excellent transparency can be obtained.

[0195] In addition, since the antifouling layer 15 of the optical laminate 10 of the present embodiment is a vapor deposition film, high abrasion resistance can be obtained compared with, for example, an antifouling film formed by a coating method. It is presumed that this is due to the following reasons. That is, in the antifouling film formed by the coating method, voids are present due to the solvent contained in the coating material. In contrast, no voids are present in the vapor deposition film due to the solvent. Therefore, it is presumed that the vapor deposition film has a higher density than the antifouling film formed by the coating method, and high abrasion resistance and alkali resistance can be obtained.

[0196] The manufacturing method of the optical laminate 10 according to the present embodiment includes an adhesion layer forming step of forming the adhesion layer 13, an optical functional layer forming step of forming the optical functional layer 14 by alternately laminating the high refractive index layer 14a and the low refractive index layer 14b, a second surface treatment step of treating the surface of the optical functional layer 14, and an antifouling layer forming step of forming the antifouling layer 15 on the surface-treated optical functional layer 14. Therefore, the adhesion between the optical functional layer 14 and the antifouling layer 15 formed on the optical functional layer 14 is good, and it becomes a material with better frictional properties and alkali resistance.

[0197] In particular, in the second surface treatment step, when the surface of the optical functional layer is treated such that the change rate of the surface roughness represented by (Formula 1) is 1 to 25%, the surface of the optical functional layer 14 changes to an appropriate roughness, and the surface is activated by etching. Therefore, the reactivity with the antifouling layer 15 formed on the optical functional layer 14 is improved, which is thus preferable.

[0198] In addition, in the manufacturing method of the optical laminate 10 according to the present embodiment, the optical laminate 10 can be continuously formed in a roll-to-roll manner, and the film thickness can be controlled with high precision. Therefore, it is preferable to form the optical functional layer 14 by sputtering in the optical functional layer forming step.

[0199] In the present embodiment, when the first surface treatment step, the optical functional layer forming step, the second surface treatment step, and the antifouling layer forming step are continuously performed while maintaining the optical laminate being manufactured under reduced pressure, as long as it does not interfere with each manufacturing step, for example, in a sputtering apparatus and an evaporation apparatus, the reduced pressure conditions in the chamber can be different.

[0200] In the present embodiment, it is preferable to measure the film formation result over time using a measuring device in any one or more of the adhesion layer forming step, the optical functional layer forming step, and the antifouling layer forming step, and feed back the result to the conditions of the manufacturing steps corresponding to the subsequent steps. Thereby, it is easy to optimize the characteristics of the entire optical laminate, and the characteristics within the plane of the optical laminate can be made uniform. In addition, the feedback of the manufacturing conditions in the same step can also be performed by the measuring device. In this case, the layer formed in this step has uniform and stable characteristics.

[0201] In the present embodiment, the case where the second surface treatment step is performed between the optical functional layer forming step and the antifouling layer forming step has been described as an example, but the second surface treatment step can be performed as needed or can be omitted. Even when the second surface treatment step is not performed, it is preferable to continuously perform the optical functional layer forming step and the antifouling layer forming step under reduced pressure.

[0202] In this embodiment, a pre-treatment device 2A, a sputtering device 1, a pre-treatment device 2B, a vapor deposition device 3, a roll unwinding device 4, and a roll winding device 5 are used. Figure 4 The manufacturing apparatus 20 shown in the figure is described by taking the case where the optical laminate 10 is continuously manufactured by the roll-to-roll method as an example, but the manufacturing apparatus for manufacturing the optical laminate 10 is not limited to Figure 4 The manufacturing apparatus 20 is shown.

[0203] For example, a production apparatus in which the roll unwinding apparatus 4, the sputtering apparatus 1, the vapor deposition apparatus 3, and the roll winding apparatus 5 are sequentially connected without including the pre-processing apparatus 2A and the pre-processing apparatus 2B may be used.

[0204] exist Figure 4 In the manufacturing apparatus 20 shown, a pretreatment chamber (not shown) for cleaning the surface of the optical function layer 14 forming the antifouling layer 15 may be provided between the chamber 33 of the vapor deposition apparatus 3 and the chamber 32 of the pretreatment apparatus 2B.

[0205] exist Figure 4 In the manufacturing apparatus 20 shown, a post-processing chamber (not shown) can be provided between the chamber 33 of the evaporation apparatus 3 and the chamber 35 of the roller winding apparatus 5, and the post-processing chamber is used to cool and / or inspect the transparent substrate 11 formed with each layer up to the anti-fouling layer 15.

[0206] exist Figure 4 In the manufacturing apparatus 20 shown, a hard coating forming device for forming a hard coating layer 12 on the surface of the transparent substrate 11 may be provided between the roll unwinding device 4 and the sputtering device 1. In this case, not only the optical functional layer 14 and the antifouling layer 15 but also the hard coating layer 12 can be continuously manufactured in a roll-to-roll manner, which is preferred.

[0207] In this embodiment, the case where a sputtering device is used to perform the optical functional layer forming process and a vapor deposition device is used to perform the anti-fouling layer forming process is described as an example, but the optical functional layer forming process and the anti-fouling layer forming process can also be performed using the same device (in one chamber) without performing the second surface treatment process.

[0208] In the optical laminate 10 of the present embodiment, various layers can be provided on the surface of the transparent substrate opposite to the surface on which the optical functional layer is formed as needed. For example, an adhesive layer for bonding with other components can also be provided. In addition, other optical films can also be provided across the adhesive layer. As other optical films, for example, films that function as polarizing films, phase difference compensation films, 1 / 2 wavelength plates, and 1 / 4 wavelength plates can be listed.

[0209] In addition, layers having functions such as antireflection, selective reflection, antiglare, polarization, phase difference compensation, viewing angle compensation or magnification, light guiding, diffusion, brightness enhancement, hue adjustment, and conductivity can also be directly formed on opposite surfaces of a transparent substrate.

[0210] In addition, the shape of the optical laminate can be a smooth shape or a shape having a moth-eye or a nanoscale concavo-convex structure exhibiting an antiglare function. Additionally, it can also be a geometric shape in the micron to millimeter range such as a lens or a prism. The shape can be formed, for example, by a combination of photolithography and etching, shape transfer, hot pressing, etc. In the present embodiment, since film formation is performed by evaporation or the like, even when the substrate has, for example, a concavo-convex shape, the concavo-convex shape can be maintained.

[0211] An article of the present embodiment is, for example, an article such as a liquid crystal display panel or an organic EL display panel in which the above-described optical laminate 10 is provided on the display surface of an image display unit. Thereby, for example, high abrasion resistance and alkali resistance can be imparted to the touch panel display units of smartphones and operating devices, and an image display device excellent in durability and suitable for practical use can be realized.

[0212] In addition, the article is not limited to an image display device. For example, as long as it is an article such as a window glass, goggles, a light-receiving surface of a solar cell, a screen of a smartphone, a display of a personal computer, an information input terminal, a tablet terminal, an AR (augmented reality) device, a VR (virtual reality) device, an electro-optical display panel, a surface of a glass table, a game machine, an operation assistance device such as an airplane or a train, a navigation system, an instrument panel, or a surface of an optical sensor to which the optical laminate 10 can be applied, it can be any article.

[0213] The embodiments of the present invention have been described above, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments or their modifications are included in the scope or gist of the invention and are included in the invention described in the claims and its equivalents.

[0214] For example, an antiglare layer can be formed instead of the hard coat 12, or any functional layer such as a soft coat having flexibility can be added as needed. They can also be laminated.

[0215] Examples

[0216] The effects of the present invention were verified.

[0217] It should be noted that the optical laminates produced in the following examples and comparative examples are an example of functioning as an antireflection film, and the gist of the present invention is not limited to these.

[0218] (Example 1)

[0219] First, a photocurable resin composition was prepared in which the content of silica particles (filler) with an average particle size of 50 nm was 28% by mass based on all the solid components of the resin composition (binder resin). As shown in Table 1, the resin composition was prepared by dissolving silica particles, acrylate, leveling agent, and a photopolymerization initiator in a solvent.

[0220] [Table 1]

[0221]

[0222] SR610: Polyethylene glycol diacrylate, average molecular weight of polyethylene glycol chain 600

[0223] CN968: 6-functional aliphatic polyurethane acrylate with a polyester backbone

[0224] Irgacure184: 1-Hydroxy-cyclohexyl-phenyl-ketone

[0225] <Hard coat forming process>

[0226] A roll-shaped TAC film with a thickness of 80 μm and a length of 3900 m was prepared as the transparent substrate 11, and the photocurable resin composition shown in Table 1 was coated on the TAC film using a gravure coater and cured by irradiating light to form a hard coat 12 with a thickness of 5 μm.

[0227] Next, in a roll-to-roll manner, the adhesion layer 13, the optical functional layer 14, and the antifouling layer 15 were successively and continuously formed on the transparent substrate 11 having the hard coat 12 by the method shown below to produce the optical laminate (antireflection film) of Example 1.

[0228] As the manufacturing apparatus, the manufacturing apparatus 20 shown in Figure 4 was used. In addition, the linear velocity was 2 m / min. The first surface treatment process, the adhesion layer forming process, the optical functional layer forming process, the second surface treatment process, and the antifouling layer forming process were continuously performed while maintaining the optical laminate during manufacturing under a reduced pressure state.

[0229] <First surface treatment process>

[0230] Next, for the hard coat 12, the glow discharge treatment was performed with a treatment intensity of 4000 W·min / m 2 .

[0231] <Adhesion layer forming process and optical functional layer forming process>

[0232] On the hard coating 12 after glow discharge treatment, in a chamber under a pressure of 1.0 Pa or less, a 5-nm-thick adhesion layer 13 composed of SiO is formed by sputtering. On the adhesion layer, an optical functional layer 14 (laminate) composed of a 15-nm-thick Nb x film (high refractive index layer), a 38-nm-thick SiO 2 O 5 film (low refractive index layer), a 30-nm-thick Nb 2 film (high refractive index layer), and a 102-nm-thick SiO 2 O 5 film (low refractive index layer) is formed. 2

[0233] <Second surface treatment process>

[0234] The surface of the optical functional layer 14 is subjected to glow discharge treatment. The cumulative output of the glow discharge treatment is 326 W·min / m 2 .

[0235] <Antifouling layer formation process>

[0236] Next, on the optical functional layer 14, an antifouling layer 15 composed of an alkoxysilane compound (KY-1901, manufactured by Shin-Etsu Chemical Co., Ltd.) having a perfluoropolyether group, which is a fluorine-containing organic compound, is formed by evaporation under the conditions of an evaporation chamber pressure of 0.01 Pa or less, an evaporation temperature of 230°C, and a linear velocity of 2.0 m / min. The optical film thickness of the obtained antifouling layer 15 is shown in Table 2.

[0237] It is wound into a roll shape to obtain the optical laminate (antireflection film) of Example 1.

[0238] [Table 2]

[0239]

[0240] (Example 2)

[0241] Except that the optical film thickness of the antifouling layer 15 is 4 nm, the same operations as in Example 1 are performed to obtain the optical laminate (antireflection film) of Example 2.

[0242] (Example 3)

[0243] Except that the optical film thickness of the antifouling layer 15 is 3 nm, the same operations as in Example 1 are performed to obtain the optical laminate (antireflection film) of Example 3.

[0244] (Example 4)

[0245] ​After proceeding to the optical functional layer formation step in the same manner as in Example 1, the TAC film having the hard coat layer 12, the adhesion layer 13, and the optical functional layer 14 formed thereon was wound and taken out from the manufacturing apparatus, and left standing in the atmosphere at a temperature of 25°C and a humidity of 55% for 30 days. Then, the TAC film having the hard coat layer 12, the adhesion layer 13, and the optical functional layer 14 formed thereon was set in the manufacturing apparatus and unwound, and the second surface treatment step and the antifouling layer formation step were carried out in the same manner as in Example 1, whereby an antifouling layer 15 was formed on the optical functional layer 14, and wound into a roll shape. Through the above steps, the optical laminate (antireflection film) of Example 4 was produced.

[0246] The optical film thickness of the antifouling layer 15 of the optical laminate of Example 4 is shown in Table 2.

[0247] (Comparative Examples 1 and 2)

[0248] After proceeding to the optical functional layer formation step in the same manner as in Example 1, the TAC film having the hard coat layer 12, the adhesion layer 13, and the optical functional layer 14 formed thereon was wound and taken out from the manufacturing apparatus, and set in a roll-to-roll coating apparatus (coater). Then, under atmospheric pressure, the TAC film having the hard coat layer 12, the adhesion layer 13, and the optical functional layer 14 formed thereon was unwound, and an antifouling agent was coated on the SiO 2 film (low refractive index layer) of the optical functional layer 14 at a linear velocity of 20 m / min using a gravure coater.

[0249] As the antifouling agent, an antifouling agent obtained by diluting an alkoxysilane compound having a perfluoropolyether group (KY-1901, manufactured by Shin-Etsu Chemical Co., Ltd.) to a concentration of 0.1 mass% using a fluorine solvent (Fluorinert FC-3283: manufactured by 3M Japan Ltd.) was used. The antifouling agent was coated so that the thickness after drying became the film thickness shown in Table 2.

[0250] (Comparative Example 3)

[0251] Except for not performing the first surface treatment step (glow discharge treatment of the surface of the hard coat layer) and the second surface treatment step (glow discharge treatment of the surface of the optical functional layer), the same operations as in Example 1 were carried out to obtain the optical laminate (antireflection film) of Comparative Example 3.

[0252] (Surface roughness Ra of the antifouling layer)

[0253] For the obtained optical laminates (antireflection films) of Examples 1 to 4 and Comparative Examples 1 to 3, the surface roughness Ra of the antifouling layer was investigated by the methods shown below. The results are shown in Table 2.

[0254] (Measurement of the surface roughness Ra of the antifouling layer)

[0255] A 50 mm × 50 mm measurement sample was cut out from the position at the center in the longitudinal direction and the center in the roll width direction of each roll with the optically laminated body coiled thereon. The surface of the sample was observed using an atomic force microscope (AFM: Atomic Force Microscope) (trade name SPA400, NanoNavi II; manufactured by Hitachi, Ltd.), and the surface roughness Ra within an area of 1 μm 2 was measured.

[0256] The surface roughness Ra of the antifouling layer is affected by the surface roughness Ra of the underlying optical functional layer. In particular, in the antifouling layer formed by vapor deposition, there are no voids caused by the solvent contained in the coating material as in the antifouling layer formed by the coating method, but it is formed densely. Therefore, compared with the antifouling layer formed by the coating method, the influence of the surface roughness Ra of the underlying optical functional layer is greater. In Examples 1 to 4, it is considered that the surface roughness of the optical functional layer increases due to glow discharge treatment, and thus the surface roughness of the antifouling layer increases due to the influence. Example 4 has a smaller surface roughness compared to Examples 1 to 3. It is considered that this is because, in Examples 1 to 3, the optical functional layer and the antifouling layer are formed without contact with the atmosphere, whereas in Example 4, the optical functional layer is in contact with the atmosphere and a natural oxide film is formed on the optical functional layer, and the roughening effect of the surface based on the glow discharge treatment is small. In addition, the difference in surface roughness between Example 1 and Comparative Example 3 is due to the presence or absence of glow discharge treatment.

[0257] In addition, the characteristics of the optical laminated bodies (antireflection films) of Examples 1 to 4 and Comparative Examples 1 to 3 were investigated respectively. The results are shown in Tables 2 to 5. The test pieces used in the characteristic measurements of Examples 1 to 4 and Comparative Examples 1 to 3 were cut out from the vicinity of the approximate center in the longitudinal direction of the roll with the optically laminated body coiled thereon.

[0258] [Table 3]

[0259]

[0260] [Table 4]

[0261]

[0262] [Table 5]

[0263]

[0264] (1) Contact angle (antifouling property)

[0265] (1-1) Contact angle measurement test with respect to pure water

[0266] Using a fully automatic contact angle meter DM-700 (manufactured by Kyowa Interface Science Co., Ltd.), the measurement was carried out by the ellipse fitting method under the following conditions. Distilled water was put into a glass syringe, and a stainless-steel needle was attached to the front end thereof, and pure water was dropped onto the optical laminates (test pieces) of Examples 1 to 4 and Comparative Examples 1 to 3.

[0267] Drop volume of pure water: 2.0 μL

[0268] Measurement temperature: 25 °C

[0269] The contact angle after 4 seconds of dropping pure water was measured at any 6 places on the surface of the test piece, and the average value thereof was taken as the pure water contact angle.

[0270] (1-2) Contact angle measurement test with respect to oleic acid, n-hexadecane, and diiodomethane (reagents)

[0271] Using a fully automatic contact angle meter DM-700 (manufactured by Kyowa Interface Science Co., Ltd.), the measurement was carried out by the ellipse fitting method under the following conditions. Each of the above reagents was put into a glass syringe, and a stainless-steel needle was attached to the front end thereof, and each reagent was dropped onto the optical laminates (test pieces) of Example 1 and Comparative Example 2, respectively.

[0272] Drop volume of each reagent: 2.0 μL

[0273] Measurement temperature: 25 °C

[0274] The contact angle after 4 seconds of dropping each reagent was measured at any 10 places on the surface of the test piece, and the average value thereof was taken as the respective contact angles of oleic acid, n-hexadecane, and diiodomethane.

[0275] (2) Fluorine content measurement test

[0276] The fluorine content (cps: count per unit time) (fluorine content before cleaning (fluorine content in the initial state)) of the optical laminates (test pieces) of Examples 1 to 4 and Comparative Examples 1 to 3 was measured.

[0277] The measurement of the fluorine content was carried out using an X-ray photoelectron spectrometer (Electron Spectroscopy for Chemical Analysis, ESCA) (PHI5000 VersaProb*eIII, manufactured by ULVAC-PHI, Inc.) and X-ray fluorescence analysis (XRF) (EDX-8000, manufactured by Shimadzu Corporation). The fluorine values (cps) obtained by the X-ray photoelectron spectrometer and X-ray fluorescence analysis were average values calculated from the results measured with n = 3 in the initial state and n = 15 after the alkali resistance test.

[0278] (3) Alkaline resistance test

[0279] Measure the optical properties of the optical laminates (test pieces) of Examples 1 to 4 and Comparative Examples 1 to 3 (samples before treatment).

[0280] Next, prepare an aqueous sodium hydroxide solution (reagent) with a concentration of 0.1 mol / L.

[0281] Then, fit a cylindrical member with an inner diameter of 38 mm to the optical laminates (test pieces) of Examples 1 to 4 and Comparative Examples 1 to 2, drop the reagent into it, and cover the upper surface opening with a glass plate. Then, after standing still at a liquid temperature of 55°C for 4 hours, wash each test piece with distilled water to obtain samples after treatment.

[0282] (3-1) Optical property measurement (hue change)

[0283] Use transparent tape to stick the back surfaces of the above-mentioned samples before treatment and after treatment to a black acrylic plate to eliminate back reflection. Then, measure the optical properties.

[0284] In the optical measurement, an integrating sphere spectrophotometer (SP-64: manufactured by X-rite Co., Ltd.) is used. Set it to a D65 light source and 10°, and calculate the change amount, i.e., the ΔE value, of the L*a*b* (based on CIE1976) values shown in the above formula (2) of the samples before treatment and after treatment based on SCI (Specular Component Include (including specular regular reflection light), a measurement method considering the reflection color of regular reflection light). It should be noted that as L0*, a0*, and b0* in the above formula (2), substitute the values of the samples before treatment, and as L1*, a1*, and b1*, substitute the values of the samples after treatment after contact with the aqueous sodium hydroxide solution.

[0285] (3-2) Test for measuring the fluorine residue amount using an alkaline solution

[0286] Operate in the same manner as the test in (2) above, use ESCA or XRF to measure the fluorine amount (cps) of the samples after treatment based on the alkaline solution, and calculate the fluorine residue rate (%) of the samples after treatment.

[0287] (4) Abrasion resistance test using steel wool

[0288] Use a friction tester type I according to JIS L0849 to make the friction body move horizontally back and forth along the surface of the optical laminates (test pieces) of Example 1 and Comparative Example 2 to obtain test pieces.

[0289] Use steel wool (No. 0000 manufactured by BONSTAR Co., Ltd.) as the friction body. The test is set with a load of 1000 g / cm 2, Stroke: 75 mm, Speed: 7 mm / s. Table 4 shows the horizontal reciprocation times of the friction body.

[0290] (4-1) Contact angle

[0291] In the same way as the test in (1-1) above, measure the contact angle of the test piece after friction, and find the difference in the contact angle of the test piece before friction and after 500 horizontal reciprocations. The test is carried out within 30 minutes after friction.

[0292] (4-2) Optical property measurement (hue change)

[0293] Operate in the same way as the test in (3-1) above, and calculate the change amount of the ΔL*a*b* value caused by SCI of the test piece before friction and after 500 horizontal reciprocations, that is, the ΔE value.

[0294] In addition, in the same way as the test in (3-1) above, calculate the change amount of the L*a*b* value shown in the above formula (3) based on SCE (Specular Component Exclude (excluding specular regular reflection light), a measurement method that does not consider the reflected color of specular reflection light) of the test piece before friction and after 500 horizontal reciprocations, that is, the ΔE value.

[0295] (5) Abrasion test using a wiping cloth (non-woven fabric wiping material)

[0296] Except for using a wiping cloth (non-woven fabric wiping material) (Bemcot Lintfree CT-8, manufactured by Asahi Kasei Corporation) as the friction body, conduct the abrasion test in the same way as the abrasion test using steel wool. The test is set with a load of 250 g / cm 2 , Stroke: 25 mm, Speed: 50 mm / s. Table 3 shows the horizontal reciprocation times of the friction body.

[0297] (5-1) Contact angle

[0298] In the same way as the test in (1-1) above, measure the contact angle of the test piece after friction, and find the difference in the contact angle of the test piece before friction and after 4000 horizontal reciprocations. The test is carried out within 30 minutes after friction.

[0299] (5-2) Fluorine residue amount measurement test

[0300] Operate in the same way as the test in (2) above, measure the fluorine amount (cps) of the processed sample after 4000 horizontal reciprocations using a wiping cloth by ESCA, and calculate the residual rate (%) of fluorine in the processed sample.

[0301] (6) Ultrasonic cleaning test

[0302] Put the fluorine-based solvent (Fluorinert FC-3283, manufactured by 3M Japan Limited) into a container, immerse the optical laminates (test pieces) of Examples 1 to 4 and Comparative Examples 1 to 3, and apply ultrasonic waves at 40 KHz and 240 W for 10 minutes using an ultrasonic cleaner (USK-5R, manufactured by ASONE Corporation). Then, rinse the test pieces with the above-mentioned fluorine-based solvent.

[0303] In the same manner as the test in (2) above, use XRF to measure the fluorine amount (cps) of the sample after ultrasonic cleaning, and calculate the residual rate (%) of fluorine in the sample after cleaning.

[0304] 〔Superiority of the antifouling layer formed by vapor deposition over the antifouling layer formed by coating〕

[0305] As shown in Tables 2 to 4, compared with Comparative Examples 1 and 2, the optical laminates of Examples 1 to 4 had a smaller contact angle difference in the abrasion test using a wiping cloth (non-woven wiping material). Compared with Comparative Examples 1 and 2, the optical laminate of Example 1 had a higher residual rate of fluorine in the abrasion test using a wiping cloth (non-woven wiping material).

[0306] Compared with Comparative Examples 1 and 2, the optical laminates of Examples 1 to 4 had less change in hue in the alkali resistance test and a higher residual rate of fluorine.

[0307] According to the results shown in Table 2, in the measurement of the contact angle showing antifouling properties, the superiority of the antifouling layer formed by vapor deposition (Example 1) was confirmed compared with the antifouling layer formed by coating (Comparative Example 2) with respect to oleic acid, n-hexadecane, and diiodomethane.

[0308] In addition, as shown in Tables 3 to 4, it was confirmed that even with an alkali solution or physical friction, Example 1 could further suppress the change in optical properties compared with Comparative Example 2.

[0309] In the wiping cloth scratch resistance test, the optical laminates of Examples 1 to 4 had a contact angle difference of 15° or less, little change, and could maintain the initial properties, which was good. In addition, in the alkali resistance test, the optical laminates of Examples 1 to 4 had a small hue change ΔE of 10 or less, which was good. In the steel wool scratch resistance test, the optical laminate of Example 1 had a contact angle difference of 15° or less, little change, and could maintain the initial properties, which was good.

[0310] In addition, according to the results shown in Table 5, in the ultrasonic cleaning test, the residual rates of fluorine in Examples 1 and 4 were both high, at 70% or more, but in Comparative Examples 1 and 2, the residual rates of fluorine were low, at 62.7% and 39.8%.

[0311] 〔Effect of glow discharge treatment〕

[0312] According to the results shown in Table 3, in the scratch resistance test of the wiping cloth, the contact angle differences of the optical laminates of Examples 1 to 4 were all 12° or less, with little change, and the initial characteristics could be maintained, which was good. However, in Comparative Example 3, the contact angle differences were all 22°, with large changes.

[0313] In addition, in the alkali resistance test, the hue changes ΔE(SCI) of the optical laminates of Examples 1 to 4 were all small, less than 10, and the fluorine residue rate was also high, 85% or more. However, in Comparative Example 3, the hue change ΔE(SCI) was large, 29.5, and the fluorine residue rate was low, 18.9%.

[0314] According to the results shown in Table 4, in the steel wool scratch resistance test, the contact angle differences of the optical laminates of Examples 1 to 3 were all 12° or less, with little change, and the hue change ΔE(SCI) was also small, 2.4 or less, and the initial characteristics could be maintained, which was good. However, in Comparative Example 3, the contact angle difference was 18°, with large changes, and the hue change ΔE(SCI) was also large, 3.9.

[0315] According to the results shown in Table 5, in the ultrasonic cleaning test, the fluorine residue rates of Examples 1 and 4 were both high, 70% or more, but the fluorine residue rate of Comparative Example 3 was low, 60.9%.

[0316] The effects of the above glow discharge treatment, that is, the improvement of abrasion resistance and alkali resistance, are the results of the following: the surface of the optical functional layer 14 is roughened to an appropriate roughness, substances with weak binding force on the surface are removed, and in addition, the surface is activated by etching, so the reactivity between the optical functional layer and the antifouling layer formed thereon is improved, and the adhesion between the optical functional layer and the antifouling layer is improved. In the alkali resistance test, it is speculated that the hue change is significantly suppressed because the intrusion of alkali components into the uppermost SiO 2 layer of the optical functional layer is prevented, and it is speculated that this is because the molecules constituting the antifouling layer are chemically bonded to the optical functional layer at a high density. Further investigation shows that the surface roughness Ra (about 5.5 nm to 8 nm) of the antifouling layers of Examples 1 to 4 may also be suitable for the high density of chemical bonds of the molecules constituting the antifouling layer.

[0317] Symbol Explanation

[0318] 10, 101, 102... optical laminate, 11... transparent substrate, 12... hard coat, 13... adhesive layer, 14... optical functional layer, 14a... high refractive index layer, 14b... low refractive index layer, 15... antifouling layer, 20... manufacturing apparatus, 1... sputtering apparatus, 2A, 2B... pretreatment apparatus, 3... evaporation apparatus, 4... roll unwinding apparatus, 5... roll winding apparatus, 20... manufacturing apparatus, 21... vacuum pump, 22... guide roller, 23... unwinding roller, 24... winding roller, 25... film forming roller, 26... cylinder roller, 31, 32, 33, 34, 35... chamber, 41... film forming section, 42... plasma discharge device, 43... evaporation source, 53... heating device.

Claims

1. An optical laminate which is an optical laminate formed by sequentially laminating a film-like transparent substrate, a hard coat layer, an adhesion layer, an optical functional layer, and an antifouling layer. The hard coat layer is composed of a cured product of an adhesive resin and a curable resin composition containing silica particles with an average particle diameter of 100 nm or less. The antifouling layer is composed of a vapor deposition film formed by vapor-depositing an alkoxysilane compound having a perfluoropolyether group. The thickness of the adhesion layer is 1 nm or more and 10 nm or less. The optical functional layer is composed of a high refractive index layer with a thickness of 5 - 50 nm, a low refractive index layer with a thickness of 10 - 80 nm, a high refractive index layer with a thickness of 20 - 200 nm, and a low refractive index layer with a thickness of 50 - 200 nm, in this order from the adhesion layer side. The optical thickness of the antifouling layer is 3 nm or more and 10 nm or less. The surface roughness Ra of the antifouling layer is 3 nm or more and 9 nm or less. The residual amount of fluorine atoms in the antifouling layer based on XRF after cleaning by irradiating ultrasonic waves at 40 KHz and 240 W for 10 minutes in a fluorine-based solvent is 70% or more.

2. An optical laminate which is an optical laminate formed by sequentially laminating a film-like transparent substrate, a hard coat layer, an adhesion layer, an optical functional layer, and an antifouling layer. The hard coat layer is composed of a cured product of an adhesive resin and a curable resin composition containing silica particles with an average particle diameter of 100 nm or less. The antifouling layer is composed of a vapor deposition film formed by vapor-depositing an alkoxysilane compound having a perfluoropolyether group. The thickness of the adhesion layer is 1 nm or more and 10 nm or less. The optical functional layer is composed of a high refractive index layer with a thickness of 5 - 50 nm, a low refractive index layer with a thickness of 10 - 80 nm, a high refractive index layer with a thickness of 20 - 200 nm, and a low refractive index layer with a thickness of 50 - 200 nm, in this order from the adhesion layer side. The optical thickness of the antifouling layer is 3 nm or more and 10 nm or less. The surface roughness Ra of the antifouling layer is 3 nm or more and 9 nm or less. The hue change ΔE value after contacting with a 0.1 mol / L aqueous sodium hydroxide solution at a liquid temperature of 55°C for 4 hours is less than 10.

3. An optical laminate which is an optical laminate formed by sequentially laminating a film-like transparent substrate, a hard coat layer, an adhesion layer, an optical functional layer, and an antifouling layer. The hard coat layer is composed of a cured product of an adhesive resin and a curable resin composition containing silica particles with an average particle diameter of 100 nm or less. The thickness of the adhesion layer is 1 nm or more and 10 nm or less. The optical functional layer is composed of a high refractive index layer with a thickness of 5 - 50 nm, a low refractive index layer with a thickness of 10 - 80 nm, a high refractive index layer with a thickness of 20 - 200 nm, and a low refractive index layer with a thickness of 50 - 200 nm, in this order from the adhesion layer side. The optical thickness of the antifouling layer is 3 nm or more and 10 nm or less. The surface roughness Ra of the antifouling layer is 3 nm or more and 9 nm or less. The antifouling layer is composed of a vapor deposition film formed by vapor-depositing an alkoxysilane compound having a perfluoropolyether group. The antifouling layer has abrasion resistance, and the abrasion resistance is as follows: Using a friction testing machine with steel wool in accordance with JIS L0849, the difference in the contact angle with respect to water before friction and after the steel wool is horizontally reciprocated 500 times is 1° or more and 12° or less.

4. The optical laminate according to any one of claims 1 to 3, wherein, the optical functional layer is any one selected from an antireflection layer, a selective reflection layer, and an antiglare layer.

5. The optical laminate according to claim 1, wherein, the antifouling layer is provided in contact with the low refractive index layer.

6. The optical laminate according to claim 1, wherein, the adhesion layer contains an oxide of Si.

7. The optical laminate according to any one of claims 1 to 6, wherein, the adhesion layer and the optical functional layer are formed by sputtering.

8. The optical laminate according to any one of claims 1 to 7, wherein, the antifouling material contains a fluorine-based organic compound.

9. An article, characterized in that, it includes the optical laminate according to any one of claims 1 to 8.

10. A method for manufacturing an optical laminate, characterized in that, it is a method for manufacturing the optical laminate according to any one of claims 1 to 8, and has: a glow discharge treatment step of subjecting the surface of the optical functional layer to surface treatment by glow discharge under reduced pressure, and an antifouling layer formation step of forming the antifouling layer composed of a vapor deposition film on one side of the optical functional layer, and the vapor deposition film is formed by vacuum-depositing an antifouling material.

11. The method for manufacturing an optical laminate according to claim 10, wherein, it has an optical functional layer formation step of forming the optical functional layer by sputtering, and the optical functional layer formation step and the antifouling layer formation step are continuously carried out under reduced pressure.

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