Optical laminate, article, and method for manufacturing optical laminate

Abstract

This optical laminate comprises: a plastic transparent substrate; a high refractive index layer disposed on the plastic transparent substrate; and a low refractive index layer disposed on the high refractive index layer. The high refractive index layer has a physical thickness of 2-10 nm, and the low refractive index layer has a physical thickness of 60-140 nm. The water vapor permeability of the optical laminate under a condition of 40°C and a relative humidity of 90% is 0.5 (g / m2 / day) or less.

Description

Optical laminate, article, and method for manufacturing an optical laminate

[0001] The present invention relates to an optical laminate, an article, and a method for manufacturing an optical laminate. This application claims priority based on Japanese Patent Application No. 2025-016666, filed in Japan on February 4, 2025, the contents of which are incorporated herein by reference.

[0002] Optical laminates, such as anti-reflective films, are installed on the outermost surface of displays in smartphones, PCs, and other devices. In recent years, displays with touch panels have become widespread, and are operated using fingers or stylus pens.

[0003] Devices equipped with displays may be used in high-humidity environments or operated by users with wet hands. Since there is a concern that the performance of the display may deteriorate when exposed to water vapor, the optical laminate installed on the outermost surface of the display is required to have a certain degree of water vapor permeability. In anti-reflective films, it is known that an anti-reflective layer is provided on a hard coat layer in which a total of four or more layers of high refractive index layers and low refractive index layers are alternately laminated (for example, Patent Document 1) as a means of suppressing water vapor permeability.

[0004] In optical laminates, another means of suppressing water vapor transmission has been proposed, which involves providing an inorganic film composed of multiple layers, including a first film and a second film, with a thickness of 20 nm or more (for example, Patent Document 2). In Patent Document 2, the first film and the second film are formed by sputtering under low pressure conditions of 0.2 Pa or less.

[0005] Japanese Patent Publication No. 2011-69995, Japanese Patent Publication No. 4269261

[0006] On the other hand, when an anti-reflective layer consisting of multiple layers is provided, as in Patent Document 1, the manufacturing time is longer, resulting in higher manufacturing costs. For this reason, anti-reflective films like the ones described above are mainly used in high-end models from a cost perspective. From the perspective of keeping the selling price of the product low, and from the perspective of using it in products in a lower price range, it is also important to reduce manufacturing costs while ensuring sufficient functionality of the product.

[0007] Although the optical laminate described in Patent Document 2 has fewer layers constituting the inorganic film compared to the anti-reflective film described in Patent Document 1, the film thickness is thick, and the pressure used to form both the first and second films is low, resulting in a poor film deposition rate and a longer manufacturing time. Therefore, it cannot be said that manufacturing costs can be sufficiently reduced.

[0008] When reducing the number of layers to suppress water vapor transmission, a low refractive index material such as SiO ２ Using a film of SiO is one possible option. ２ When using a single layer film, some degree of water vapor permeation suppression can be expected. However, if SiO is on the substrate... ２ When forming a single layer, a large thickness is required to suppress water vapor permeation. Increasing the thickness increases the risk of microcrack formation due to arcing during manufacturing, which can actually make water vapor permeation easier. This phenomenon is more pronounced with hard materials such as silicon, and there is a need to improve the water vapor permeation suppression function without excessively increasing the thickness.

[0009] This invention was made in view of the above circumstances, and aims to provide an optical laminate, an article, and a method for manufacturing an optical laminate that can reduce manufacturing costs while ensuring sufficient water vapor transmission suppression function.

[0010] To solve the above problems, the present invention provides the following means.

[0011] (1) An optical laminate according to one aspect of the present invention comprises a transparent plastic substrate, a high refractive index layer provided on the transparent plastic substrate, and a low refractive index layer provided on the high refractive index layer, wherein the physical thickness of the high refractive index layer is 2 nm or more and 10 nm or less, the physical thickness of the low refractive index layer is 60 nm or more and 140 nm or less, and the water vapor transmission rate under conditions of 40°C and 90% relative humidity is 0.5 g / m³ ２ ( / day) is less than or equal to the following.

[0012] (2) In the optical laminate described in (1) above, the total light transmittance may be 90% or more.

[0013] (3) In the optical laminate of (1) or (2) above, the high refractive index layer may contain, as a main component, one or both of oxides of Nb and Ti.

[0014] (4) In the optical laminate of (1) to (3) above, the high refractive index layer may contain, as a main component, an Nb oxide represented by NbOx.

[0015] (5) In the optical laminate of (1) to (4) above, the low refractive index layer may be composed of any one of SiO ２ , Al ２ O ３ and SiON.

[0016] (6) The optical laminate of (1) to (5) above may include the plastic transparent substrate, the high refractive index layer provided on the plastic transparent substrate, the low refractive index layer provided on the high refractive index layer, and an antifouling layer provided in contact with the low refractive index layer.

[0017] (7) The optical laminate of (1) to (6) above may consist of the plastic transparent substrate, the high refractive index layer, the low refractive index layer, and the antifouling layer.

[0018] (8) The optical laminate of (1) to (7) above further includes a middle refractive index layer composed of a composition that exhibits a refractive index between the refractive indices of the compositions contained as main components in two adjacent layers, either between the plastic transparent substrate and the high refractive index layer or between the high refractive index layer and the low refractive index layer, and may consist of the plastic transparent substrate, the high refractive index layer, the low refractive index layer, the antifouling layer, and the middle refractive index layer.

[0019] (9) In the optical laminate of (1) to (8) above, the plastic transparent substrate has a plastic film that is a TAC film or a PET film, the high refractive index layer and the low refractive index layer are sputtered films, the visual reflectance is 3% or less, the sheet resistance value on the antifouling layer side is 10 ８ Ω / □ or more, and when light with a wavelength of 380 nm or more and 780 nm or less is incident by a standard light source D65, the a ＊ value in the CIE-LAB color system of the total reflected light is -3 ≤ a ＊≤ 30, b ＊ The value is -30 ≤ b ＊ It may also be ≤ 18.

[0020] (10) In the optical laminates described in (1) to (9) above, the transparent plastic substrate may consist of the plastic film, a hard coat layer, and an adhesion layer.

[0021] (11) An article relating to one embodiment of the present invention comprises an optical laminate according to the above embodiment.

[0022] (12) In the article described in (11) above, the optical laminate may be installed on the surface of the touch panel.

[0023] (13) A method for manufacturing an optical laminate according to one aspect of the present invention comprises: a high refractive index layer formation step of forming a high refractive index layer with a physical thickness of 2 nm to 10 nm on a transparent plastic substrate by sputtering; and a low refractive index layer formation step of forming a low refractive index layer with a physical thickness of 60 nm to 140 nm on the high refractive index layer by sputtering, wherein the pressure in the high refractive index layer formation step is 0.3 Pa or more.

[0024] (14) In the method for manufacturing the optical laminate described in (13) above, the pressure may be 0.1 Pa or more in the low refractive index layer formation step.

[0025] According to the present invention, it is possible to provide an optical laminate, an article, and a method for manufacturing an optical laminate that can reduce manufacturing costs while ensuring sufficient water vapor transmission suppression function.

[0026] This is a cross-sectional view showing an example of the configuration of an optical laminate according to one embodiment of the present invention. This is a cross-sectional view showing a modified example of the optical laminate of Figure 1. This is a cross-sectional view showing another modified example of the optical laminate of Figure 1. This is a cross-sectional view showing another modified example of the optical laminate of Figure 1. This is a schematic diagram showing an example of the configuration of a manufacturing apparatus that can be used in the manufacturing method of an optical laminate according to one embodiment of the present invention. This is a perspective view showing an example of the configuration of a touch panel to which the optical laminate of the present invention is bonded. This is a graph showing the reflectance of the optical laminates of Example 4 and Comparative Example 5 for each wavelength.

[0027] The following description of this embodiment will be made in detail with reference to the drawings as appropriate. The drawings used in the following description may be enlarged for convenience in order to clearly illustrate the features of the present invention, and the dimensional ratios of each component may differ from those in reality. The materials, dimensions, etc., exemplified in the following description are examples only, and the present invention is not limited to them; it can be modified as appropriate within the scope of achieving its effects. In each figure, similar components are denoted by the same reference numerals, and their descriptions are omitted.

[0028] [Optical Laminate] Figure 1 is a cross-sectional view showing an example of the configuration of an optical laminate according to one embodiment of the present invention. The optical laminate 101 shown in Figure 1 comprises a transparent plastic substrate 10A, a high refractive index layer 21 provided on the transparent plastic substrate 10A, and a low refractive index layer 22 provided on the high refractive index layer 21. The optical laminate 101 shown in Figure 1 consists of a transparent plastic substrate 10A, a high refractive index layer 21, and a low refractive index layer 22.

[0029] In the optical laminate 101, the physical thickness of the high refractive index layer 21 is 2 nm or more and 10 nm or less, and the physical thickness of the low refractive index layer 22 is 60 nm or more and 140 nm or less. The optical laminate 101 has a water vapor transmission rate of 0.5 g / m³ under conditions of 40°C and 90% relative humidity. ２ ( / day) is less than or equal to the following.

[0030] In this embodiment, "physical thickness" can be determined by measuring the thickness at 20 points on a cross-sectional image taken using a transmission electron microscope (TEM) or scanning transmission electron microscope (STEM), and taking the average value of the 20 points. In this embodiment, "optical thickness" is the product of physical thickness and refractive index. Unless otherwise specified, "refractive index" is the refractive index for light with a wavelength of 550 nm in an atmosphere at a temperature of 25°C.

[0031] (Transparent Plastic Substrate) The transparent plastic substrate 10A is not particularly limited, but is preferably composed of a plastic film. The flexibility and thickness of the transparent plastic substrate 10A are not particularly limited, and materials with high flexibility or low flexibility can be used, and its thickness may be large or small. Examples of constituent materials of the plastic film include cellulosic resins such as triacetylcellulose, polyester 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. Compared to glass substrates, these materials have a higher water vapor permeability, and by applying them to the present invention, it is possible to significantly improve the water vapor permeability.

[0032] As the transparent plastic substrate 10A, from the viewpoint of cost-effectiveness and optical properties, a film selected from the group consisting of polyester resins, polyamide resins, polyimide resins, and cellulose resins is preferred, and a film selected from the group consisting of PET film and TAC film is more preferred.

[0033] The transparent plastic substrate 10A may contain reinforcing materials, provided that these do not significantly impair its optical properties. Examples of reinforcing materials include cellulose nanofibers and silica.

[0034] The thickness of the transparent plastic substrate 10A is not particularly limited, but for example, when manufacturing the optical laminate 101 by roll-to-roll, it is 20 to 1000 μm, preferably 30 to 300 μm, more preferably 40 to 200 μm, and may also be 50 to 150 μm. If the thickness of the transparent plastic substrate 10A is 20 μm or more, the rigidity of the substrate itself is ensured, and wrinkles are less likely to occur even when stress is applied to the optical laminate 101. Furthermore, if the thickness of the transparent plastic substrate 10A is 40 μm or more, the rigidity of the substrate itself is further ensured, and the mechanical strength of the optical laminate 101 is improved.

[0035] When manufacturing the optical laminate 101 by roll-to-roll, if the thickness of the transparent plastic substrate 10A is 1000 μm or less, the optical laminate 101 during manufacturing and the manufactured optical laminate 101 can be easily wound into a roll, allowing for efficient manufacturing of the optical laminate 101. Furthermore, if the thickness of the transparent plastic substrate 10A is 300 μm or less, it becomes possible to thin and lighten the optical laminate 101. If the thickness of the transparent plastic substrate 10A is 200 μm or less, it is preferable that the optical laminate 101 can be manufactured more efficiently, and further thinning and weight reduction is possible.

[0036] The transparent plastic substrate 10A may have been pre-treated on its surface with etching treatments such as sputtering, corona discharge, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, and / or undercoating treatments. Furthermore, if necessary, the surface of the transparent plastic substrate 10A may be cleaned and dust-free by solvent cleaning, ultrasonic cleaning, or the like.

[0037] (High refractive index layer) The high refractive index layer 21 is provided on the transparent plastic substrate 10A. In the optical laminate 101, the high refractive index layer 21 is provided in contact with the transparent plastic substrate 10A. The physical thickness of the high refractive index layer 21 is in the range of 2 nm to 10 nm, preferably 3 nm to 8 nm, and more preferably 4 nm to 7 nm. A physical thickness of 2 nm or more for the high refractive index layer 21 can sufficiently improve water vapor transmittance. A physical thickness of 10 nm or less for the high refractive index layer 21 can shorten the film formation time and reduce the amount of material used, resulting in lower manufacturing costs and suppression of deterioration of the hue of reflected light.

[0038] The high refractive index layer 21 mainly contains, for example, one or more oxides of Nb, Ti, and Ta, or Si oxynitrides, and is preferably an oxide of Nb or Ti, or both, and is more preferably an oxide of Nb from the viewpoint of film deposition rate. The main component of the high refractive index layer 21 is, for example, niobium pentoxide (Nb ２ O ５ (Refractive index 2.3), Titanium oxide (TiO) ２, refractive index 2.3 or higher and 2.5 or lower), tantalum pentoxide (Ta ２ O ５ The oxide of Nb is preferably niobium pentoxide (Nb), which has a refractive index of 2.2. ２ O ５ In addition to the above, oxygen-deficient materials represented by the general formula NbOx may be used (where x is 2.5 or less). Similarly, oxygen-deficient oxides of Ti and Ta may be used. The high refractive index layer 21 is, for example, a sputtered film of such a material. In this specification, a thin film formed by the sputtering method is referred to as a sputtered film.

[0039] The refractive index of the high refractive index layer 21 should be higher than that of the low refractive index layer 22, which will be described later. For example, it should be 2.0 or more and 3.0 or less, preferably 2.1 or more and 2.8 or less, and may also be 2.2 or more and 2.6 or less. By having the high refractive index layer 21 composed of a sputtered film of such a material, both sufficient water vapor transmission suppression function and reflectance reduction function can be ensured with the above physical thickness.

[0040] In this specification, "main component" refers to the component with the highest content, for example, with a content of 80% by mass or more. A predetermined layer being composed of a predetermined material means that the content of that material in the layer is 95% by mass or more, preferably 99% by mass or more. The refractive index of each layer can be the refractive index of the main component metal oxide of that layer. The optical thickness can be calculated as the product of the refractive index of the metal oxide contained as the main component in each layer and the thickness of each layer. Furthermore, in each layer, the content of elements not constituting the main component is less than 20% by mass, and the content of elements other than the material constituting the predetermined layer is less than 5% by mass or less than 1% by mass. Compositional analysis of each layer can be performed by X-ray electron spectroscopy (XPS).

[0041] (Low refractive index layer) The low refractive index layer 22 is provided on the high refractive index layer 21. In the optical laminate 101, the low refractive index layer 22 is provided in contact with the high refractive index layer 21. The physical thickness of the low refractive index layer 22 is 60 nm to 140 nm, preferably 80 nm to 135 nm, more preferably 90 nm to 130 nm, and may be 90 nm to 120 nm or 110 nm to 130 nm. If the physical thickness of the low refractive index layer 22 is 60 nm or more, it is considered that sufficient water vapor permeability can be achieved in combination with the high refractive index layer 21. The thinner the physical thickness of the low refractive index layer 22, the shorter the film formation time and the lower the manufacturing cost, as well as the higher the flexibility and bending resistance. Furthermore, it is considered that the effect of suppressing water vapor permeability saturates even if the physical thickness of the low refractive index layer 22 is greater than 140 nm.

[0042] The low refractive index layer 22 is composed of, for example, one of Si oxide, Al oxide, and Si oxynitride. Si oxide is, for example, SiO ２ (Refractive index 1.5). An example of an oxide of Al is Al ２ O ３ (Refractive index 1.8). Si oxynitrides include, for example, SiON (refractive index 1.5 to 2.0). These materials are expected to have water vapor transmission suppression and reflectance reduction functions, but in particular, from the viewpoint of low refractive index and low absorption of visible light, SiO ２ It is preferable that this is the case. The low refractive index layer 22 is, for example, a sputtered film of such a material.

[0043] Furthermore, even if the high refractive index layer 21 mainly contains Si oxynitride, the oxygen and nitrogen content can be adjusted to use Si oxynitride with a lower refractive index than the high refractive index layer 21 as the low refractive index layer 22. In Si oxynitride, the lower the O content and the higher the N content, the higher the refractive index.

[0044] In addition to the above materials, the low refractive index layer 22 is made of zirconia (ZrO) from the viewpoint of alkali resistance. ２ ) etc. may be added.

[0045] The refractive index of the low refractive index layer 22 is, for example, 1.2 or more and 2.0 or less, preferably 1.2 or more and 1.6 or less, and more preferably 1.3 or more and 1.5 or less.

[0046] According to the optical laminate 101 of this embodiment, by providing a thin, high refractive index layer 21 between the transparent plastic substrate 10A and the low refractive index layer 22, the water vapor permeability can be significantly improved compared to the case where a single layer of material such as that used in the low refractive index layer 22 is used. This remarkable improvement in water vapor permeability is presumed to be due to the labyrinth effect.

[0047] Furthermore, the provision of a high refractive index layer 21 and a low refractive index layer 22 provides low reflectivity in addition to the water vapor transmission suppression function. The total thickness of the high refractive index layer 21 and the low refractive index layer 22 is, for example, 65 nm or more and 145 nm or less, preferably 140 nm or less, and more preferably 135 nm or less.

[0048] As described above, the optical laminate 101 according to this embodiment has improved optical properties compared to the case where a single layer of material used for the low refractive index layer 22 is used on the substrate, by providing a thin high refractive index layer 21 together with a low refractive index layer 22. For example, the optical laminate 101 according to this embodiment has a total light transmittance of 90% or more, and it is also possible to have 92% or more or 93% or more. Furthermore, for example, the optical laminate 101 according to this embodiment has a luminous reflectance Y (SCI) of 3.5% or less, and it is also possible to have 3.0% or less, 2.5% or less or 2.0% or less.

[0049] Figure 2 is a cross-sectional view showing a modified example of the optical laminate 101 of Figure 1. The optical laminate 102 shown in Figure 2 comprises a transparent plastic substrate 10B, a high refractive index layer 21 provided on the transparent plastic substrate 10B, a low refractive index layer 22 provided on the high refractive index layer 21 in contact with the high refractive index layer 21, and an anti-fouling layer 14 provided in contact with the low refractive index layer 22. The optical laminate 102 shown in Figure 2 consists of a transparent plastic substrate 10B, a high refractive index layer 21, a low refractive index layer 22, and an anti-fouling layer 14. In the following modified examples, components similar to those in the optical laminate according to the above embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0050] The transparent plastic substrate 10B consists of a plastic film 11, a hard coat layer 12, and an adhesion layer 13, which are laminated in order from the side separated from the anti-fouling layer 14. The plastic film 11 can be the same as the plastic film that constitutes the transparent plastic substrate 10A according to the above embodiment. The transparent plastic substrate 10B includes layers made of non-plastic materials such as the adhesion layer 13, but in this embodiment, for the sake of explanation, the plastic film 11, hard coat layer 12, and adhesion layer 13 provided on the optical laminate are collectively referred to as the transparent plastic substrate. The transparent plastic substrate of the optical laminate may be composed of one or two of the following components from the above three components. That is, the transparent plastic substrate does not necessarily have to have all of the plastic film 11, hard coat layer 12, and adhesion layer 13 as essential components, and may consist of a plastic film 11 and a hard coat layer 12, a plastic film 11 and an adhesion layer 13, or a plastic film 11 alone.

[0051] (Hard coat layer) The hard coat layer 12 is a layer that is in contact with the plastic film 11. The hard coat layer 12 is not particularly limited and known materials can be used. The hard coat layer 12 may, for example, contain a binder resin and a filler. The hard coat layer 12 may also contain a leveling agent.

[0052] The binder resin is preferably transparent and can be, for example, an ultraviolet-curable resin, an ionizing radiation-curable resin, a thermoplastic resin, or a thermosetting resin.

[0053] The thickness of the hard coat layer 12 is, for example, 0.5 μm to 100 μm, preferably 1 μm to 20 μm, and more preferably 1 μm to 10 μm. If the thickness of the hard coat layer 12 is 1 μm or more, manufacturing scratches are less likely to occur. Also, if the thickness of the hard coat layer 12 is 20 μm or less, it becomes possible to make the optical laminate 100 thinner and lighter. Furthermore, if the thickness of the hard coat layer 12 is 20 μm or less, microcracks are less likely to occur in the hard coat layer 12 when the optical laminate 102 is bent during manufacturing, resulting in good productivity.

[0054] The filler contained in the hard coat layer 12 may consist of organic materials, inorganic materials, or a combination of both. Examples of inorganic fillers include metal oxide particles. The filler contained in the hard coat layer 12 can be selected from a variety of options depending on the application of the optical laminate, from the viewpoints of anti-glare properties, adhesion to other layers, and anti-blocking properties. As fillers, known materials such as silica (silicon oxide) nanoparticles, alumina (aluminum oxide) nanoparticles, and organic nanoparticles can be used.

[0055] When the filler is silica particles and / or alumina particles, the average primary particle diameter of the filler is, for example, 800 nm or less, preferably 200 nm or less, more preferably 10 nm to 100 nm, and even more preferably 10 nm to 80 nm. When the filler is organic fine particles, the average primary particle diameter of the organic fine particles is, for example, 10 μm or less, preferably 5 μm or less, and more preferably 0.5 μm to 4 μm. The average primary particle diameter of the filler can be calculated, for example, using particle diameter and particle number values ​​obtained by observation using a scanning electron microscope or a transmission electron microscope. When using a transmission electron microscope (TEM), the average primary particle diameter of the filler is obtained by photographing the filler with TEM, and for fillers confirmed on the two-dimensional image, the maximum length among the distances between two points on the contour line of the primary particles of 50 or more randomly selected fillers is taken as the particle diameter, and the average value is adopted.

[0056] (Adhesion layer) The adhesion layer 13 is provided between the hard coat layer 12, which is an organic film, and the high refractive index layer 21, which is an inorganic film, and is formed to improve adhesion.

[0057] The adhesion layer 13 is preferably made of an oxygen-deficient metal oxide or metal. An oxygen-deficient metal oxide refers to a metal oxide in which the number of oxygen atoms is insufficient compared to the stoichiometric composition. Examples of oxygen-deficient metal oxides include SiOx, AlOx, TiOx, ZrOx, CeOx, MgOx, ZnOx, TaOx, SbOx, SnOx, and MnOx. Examples of metals include Si, Al, Ti, Zr, Ce, Mg, Zn, Ta, Sb, Sn, Mn, and In. The adhesion layer 13 may, for example, be made of SiOx in which x is greater than 0 and less than 2.0. The adhesion layer may also be formed from a mixture of multiple metals or metal oxides. The adhesion layer 13 is formed, for example, by a sputtering method. The adhesion layer 13 contains an inorganic oxide as its main component, and is preferably composed of an inorganic oxide.

[0058] The thickness of the adhesion layer 13 is preferably greater than 0 nm and less than or equal to 20 nm, and particularly preferably between 1 nm and 10 nm, from the viewpoint of maintaining adhesion between the hard coat layer 12 and the high refractive index layer 21 and obtaining good optical properties. Note that if the adhesion between the hard coat layer 12 and the high refractive index layer 21 is good, the adhesion layer 13 may not necessarily be provided.

[0059] (Anti-fouling layer) The anti-fouling layer 14 is provided on the low refractive index layer 22. Furthermore, when applied to touch panels, etc., the anti-fouling layer 14 suppresses wear and tear of the low refractive index layer 22 through its abrasion resistance and scratch resistance, and also prevents fouling.

[0060] The antifouling layer 14 is, for example, a vapor-deposited film obtained by depositing an antifouling material. Known materials can be used as the antifouling material for the antifouling layer 14, and examples include fluorine compounds as well as fluorine-free silicone compositions. The antifouling layer 14 can be formed on one surface of the low refractive index layer 22 by, for example, a wet coating method such as the reverse coating method, die coating method, or gravure coating method, or a dry coating method such as the vacuum deposition method or CVD method. If the antifouling layer 14 contains a fluorine-based compound, the abrasion resistance and alkali resistance of the optical laminate 102 are further improved.

[0061] The fluorine-based compound contained in the antifouling layer 14 is, for example, a fluorine-based organic compound. A fluorine-based organic compound is, for example, a compound consisting of a fluorine-modified organic group and a reactive silyl group (for example, an alkoxysilane). Examples of commercially available products that can be used in the antifouling layer 14 include Optool DSX (manufactured by Daikin Corporation) and the KY-100 series (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0062] A compound consisting of a fluorine-modified organic group and a reactive silyl group (e.g., alkoxysilane) is used in the antifouling layer 14, and SiO is used in the low refractive index layer 22. ２ When used, the silanol group, which is the skeleton of the fluorine-based organic compound, and SiO ２ Siloxane bonds are formed between them. The siloxane bonds enhance the adhesion between the low refractive index layer 22 and the antifouling layer 14.

[0063] The optical thickness of the antifouling layer 14 is, for example, 1 nm to 20 nm, preferably 3 nm to 10 nm. If the thickness of the antifouling layer 14 is 1 nm or more, sufficient abrasion resistance can be ensured when the optical laminate 102 is applied to touch panel applications, etc. If the thickness of the antifouling layer 14 is 20 nm or less, the time required for deposition is shortened, and manufacturing can be done efficiently.

[0064] The antifouling layer 14 may contain additives such as light stabilizers, ultraviolet absorbers, colorants, antistatic agents, lubricants, leveling agents, defoamers, antioxidants, flame retardants, infrared absorbers, and surfactants, as needed.

[0065] In this embodiment, the total thickness of the sputtered film in the optical laminate 102, i.e., the sum of the physical thicknesses of the adhesion layer 13, the high refractive index layer 21, and the low refractive index layer 22 (total thickness), is, for example, 70 nm to 150 nm, preferably 80 nm to 145 nm, and more preferably 100 nm to 140 nm.

[0066] Figures 3 and 4 are cross-sectional views showing other modifications of the optical laminate of Figure 1. As shown in Figures 3 and 4, the optical laminate according to this embodiment may further include intermediate refractive index layers 25A and 25B having a refractive index intermediate between the high refractive index layer 21 and the low refractive index layer 22, between the transparent plastic substrate 10B and the high refractive index layer 21, or between the high refractive index layer 21 and the low refractive index layer 22. Here, in this embodiment, an intermediate refractive index means a refractive index of a magnitude between the two. The refractive index of the intermediate refractive index layers 25A and 25B is, for example, about 1.6 to 1.9, and a specific material may be, for example, Al ２ O ３ These include silicon oxynitride (refractive index 1.8) and silicon oxide (refractive index 1.5 to 2.5). The intermediate refractive index layer is, for example, a sputtered film of such a material. The intermediate refractive index layers 25A and 25B mainly contain inorganic oxides and are preferably composed of inorganic oxides.

[0067] The optical laminate 103 shown in Figure 3 includes a medium refractive index layer 25A between a transparent plastic substrate 10B and a high refractive index layer 21. In the optical laminate 103, an adhesion layer 13 is formed on the side of the transparent plastic substrate 10B closest to the anti-fouling layer 14. Therefore, it is preferable that the medium refractive index layer 25A has a refractive index intermediate between that of the adhesion layer 13 and the high refractive index layer 21.

[0068] Furthermore, the optical laminate 104 shown in Figure 4 includes an intermediate refractive index layer 25B between the high refractive index layer 21 and the low refractive index layer 22. The intermediate refractive index layer 25B has an intermediate refractive index between the two layers that are in contact in the stacking direction. That is, the intermediate refractive index layer 25B has a refractive index between the high refractive index layer 21 and the low refractive index layer 22.

[0069] The physical thickness of the intermediate refractive index layers 25A and 25B can be, for example, 50 nm or less. The physical thickness of the intermediate refractive index layers 25A and 25B can be, for example, 3 nm or more. By providing the intermediate refractive index layers 25A and 25B to the optical laminates 103 and 104, the manufacturing cost can be reduced by making the thickness sufficiently small, and further improvements in water vapor transmission suppression function and optical properties can be expected.

[0070] In the optical laminates 103 and 104, the total thickness of the sputtered film can be, for example, 65 nm or more and 200 nm or less.

[0071] Even with optical laminates 102, 103, and 104 as shown in Figures 2 to 4, similar to optical laminate 101, it is possible to achieve remarkably superior water vapor transmission suppression, reduced reflectivity, and improved optical properties compared to the case where a single layer of material used in the low refractive index layer 22 is used on the substrate.

[0072] [Method for Manufacturing an Optical Laminate] Next, the method for manufacturing an optical laminate according to this embodiment will be described using the method for manufacturing the optical laminate 102 according to the above embodiment as an example. The method for manufacturing an optical laminate according to this embodiment comprises a high refractive index layer formation step of forming a high refractive index layer 21 with a physical thickness of 2 nm to 10 nm on a transparent plastic substrate by sputtering, and a low refractive index layer formation step of forming a low refractive index layer 22 with a physical thickness of 60 nm to 140 nm on the high refractive index layer 21 by sputtering, wherein the pressure is 0.3 Pa or more in the high refractive index layer formation step.

[0073] In this embodiment, as an example of a method for manufacturing an optical laminate, the case in which an optical laminate 102 is manufactured using a plastic film 11 wound in a roll shape will be described. The present invention is not limited to the following example, and for example, an optical laminate may be manufactured using a batch-type manufacturing apparatus. Figure 5 is a schematic diagram showing an example of the configuration of a manufacturing apparatus that can be used in a method for manufacturing an optical laminate according to one embodiment of the present invention. First, the plastic film 11 wound in a roll shape is unwound.

[0074] (Hard Coat Layer Formation Process) Next, a material containing the material to be formed into the hard coat layer 12 is applied onto the plastic film 11 and cured by a known method corresponding to the material to be formed into the hard coat layer 12. This forms a hard coat layer 12 on the plastic film 11 (hard coat layer formation process). The material used may contain, as necessary, fillers such as metal oxide particles, one or more additives such as polymerization initiators, leveling agents, viscosity modifiers (thixotropic agents, thickeners, etc.), antistatic agents, antiblocking agents, dispersants, dispersion stabilizers, antioxidants, ultraviolet absorbers, defoamers, surfactants, and solvents capable of dissolving or dispersing these components. As a polymerization initiator, for example, a photopolymerization initiator is used. For example, an ultraviolet-curable resin composition containing metal oxide particles, a urethane (meth)acrylate oligomer, a trifunctional or more (meth)acrylate monomer, a bifunctional (meth)acrylate monomer, and a photopolymerization initiator is uniformly mixed using a stirrer such as a disper according to a conventional method.

[0075] Next, the UV-curable resin composition is applied to the substrate. The application method is not particularly limited, and known methods can be used. Known application methods include, for example, microgravure coating, wire bar coating, direct gravure coating, die coating, dip coating, spray coating, reverse roll coating, curtain coating, comma coating, knife coating, and spin coating.

[0076] Next, a hard coat layer 12 is formed by drying and photocuring the ultraviolet-curable resin composition on the substrate. The drying conditions are not particularly limited and may be natural drying or artificial drying by adjusting the drying humidity and drying time. However, when air is blown onto the paint surface during drying, it is preferable to prevent wind ripples from forming on the surface of the coating film. This is because wind ripples can worsen the appearance of the coating and cause unevenness in surface thickness. In addition to ultraviolet light, energy rays such as gamma rays, alpha rays, and electron beams can be used as light to cure the ultraviolet-curable resin composition.

[0077] Here, if the hard coat layer 12 contains metal oxide particles, it is preferable to etch the surface of the hard coat layer 12 to make the metal oxide particles protrude. The method for making the metal oxide particles protrude is not particularly limited as long as it is possible to selectively etch the resin of the hard coat layer 12, and for example, glow discharge treatment, plasma treatment, ion etching, alkali treatment, etc. can be used. Among these, it is preferable to use glow discharge treatment which can treat a large area. After that, the plastic film 11 with the hard coat layer 12 formed on its surface is wound into a roll shape by a known method.

[0078] Next, an adhesion layer forming step is performed to form an adhesion layer 13 on the hard coat layer 12, a high refractive index layer forming step is performed to form a high refractive index layer 21, and a low refractive index layer forming step is performed to form a low refractive index layer 22. After that, an antifouling layer forming step is performed to form an antifouling layer 14 on the low refractive index layer 22. In this embodiment, it is preferable to perform a first surface treatment step to treat the surface of the hard coat layer 12 before the high refractive index layer forming step, and then to perform the adhesion layer forming step, the high refractive index layer forming step, and the low refractive index layer forming step. Also, in this embodiment, it is preferable to perform a second surface treatment step to treat the surface of the low refractive index layer 22 after the low refractive index layer forming step, and then to perform the antifouling layer forming step.

[0079] A specific example of a manufacturing apparatus that can be used in the manufacturing method of the optical laminate of this embodiment is the manufacturing apparatus 50 shown in Figure 5. The manufacturing apparatus 50 shown in Figure 5 comprises a roll unwinding device 4, a pretreatment device 2A, a sputtering device 1, a pretreatment device 2B, a vapor deposition device 3, and a roll winding device 5. As shown in Figure 5, these devices 4, 2A, 1, 2B, 3, and 5 are connected in this order. The manufacturing apparatus 50 shown in Figure 5 is a roll-to-roll type manufacturing apparatus that continuously forms multiple layers on a substrate by unwinding the substrate from a roll, passing it through the connected devices (in Figure 5, the pretreatment device 2A, the sputtering device 1, the pretreatment device 2B, and the vapor deposition device 3) in succession, and then winding it up.

[0080] When manufacturing an optical laminate 102 using a roll-to-roll manufacturing apparatus, the transport speed (line speed) of the optical laminate 102 during manufacturing can be set as appropriate. The transport speed is preferably, for example, 0.5 m / min or more and 20 m / min or less, and more preferably 0.5 m / min or more and 10 m / min or less.

[0081] <Roll Unwinding Device> The roll unwinding device 4 shown in Figure 5 has a chamber 34 whose interior is kept in a predetermined reduced-pressure atmosphere, one or more vacuum pumps 51 (one in Figure 5) that discharge the gas in the chamber 34 to create a reduced-pressure atmosphere, and an unwinding roll 53 and a guide roll 52 installed in the chamber 34. As shown in Figure 5, the chamber 34 is connected to the chamber 31 of the sputtering device 1 via the pretreatment device 2A. A plastic film 11 with a hard coat layer 12 formed on its surface is wound around the unwinding roll 53. The unwinding roll 53 supplies the plastic film 11 with the hard coat layer 12 formed on its surface to the pretreatment device 2A at a predetermined transport speed.

[0082] <Pretreatment device 2A> The pretreatment device 2A shown in Figure 5 comprises a chamber 32 whose interior is kept in a predetermined reduced-pressure atmosphere, a can roll 56, a plurality (two in Figure 5) of guide rolls 52, and a plasma discharge device 42. As shown in Figure 5, the can roll 56, the guide rolls 52, and the plasma discharge device 42 are installed inside the chamber 32. As shown in Figure 5, the chamber 32 is connected to the chamber 31 of the sputtering device 1.

[0083] The can roll 56 and guide roll 52 transport the plastic film 11 with the hard coat layer 12 formed on it, which has been sent from the roll unwinding device 4, at a predetermined transport speed, and send the plastic film 11 with the hard coat layer 12 surface treated to the sputtering device 1. As shown in Figure 5, the plasma discharge device 42 is positioned opposite the outer surface of the can roll 56 at a predetermined distance apart. The plasma discharge device 42 ionizes a gas by glow discharge. The gas is preferably inexpensive, inert, and does not affect the optical properties, and for example, argon gas, oxygen gas, nitrogen gas, helium gas, etc. can be used. In this embodiment, it is preferable to use argon gas or oxygen gas as the gas.

[0084] <Sputtering Apparatus> The sputtering apparatus 1 shown in Figure 5 comprises a chamber 31 whose interior is kept under a predetermined reduced pressure atmosphere, one or more vacuum pumps 51 (two in Figure 5) that discharge the gas from the chamber 31 to create a reduced pressure atmosphere, a film deposition roll 55, a plurality of guide rolls 52 (two in Figure 4), and a plurality of film deposition units 41 (four in the example shown in Figure 5). As shown in Figure 5, the film deposition roll 55, the guide rolls 52, and the film deposition units 41 are installed inside the chamber 31. As shown in Figure 5, the chamber 31 is connected to the chamber 32 of the pretreatment apparatus 2B.

[0085] The film-forming roll 55 and guide roll 52 transport the plastic film 11 with a hard coat layer 12 formed on its surface, which has been sent from the pre-treatment device 2A, at a predetermined transport speed, and supply the plastic film 11 with an adhesion layer 13, a high refractive index layer 21, and a low refractive index layer 22 formed on the hard coat layer 12 to the pre-treatment device 2B. In the sputtering apparatus 1 shown in Figure 5, the adhesion layer 13 is laminated on the hard coat layer 12 of the plastic film 11 running on the film-forming roll 55 by sputtering, and the high refractive index layer 21 and the low refractive index layer 22 are laminated on top of that. In the sputtering method, thin films can be continuously deposited while transporting the plastic film with the hard coat layer 12 formed on it using a roll-to-roll method. In the sputtering method, film deposition is carried out while introducing an inert gas such as argon, and a reactive gas such as oxygen as needed, into the chamber. When each layer composed of oxides is formed by the sputtering method, either a method using an oxide target or reactive sputtering using a metal target can be used.

[0086] As shown in Figure 5, the film-forming sections 41 are arranged opposite the outer surface of the film-forming roll 55 at a predetermined distance apart, and multiple sections are provided to surround the film-forming roll 55.

[0087] Each film deposition section 41 is equipped with a predetermined target (not shown). A voltage is applied to the target by a known structure. In this embodiment, a gas supply section (not shown) that supplies a predetermined reactive gas and carrier gas to the target at a predetermined flow rate, and a known magnetic field source (not shown) that forms a magnetic field on the surface of the target are provided near the target.

[0088] The target material, as well as the type and flow rate of the inert gas and reactive gas, are appropriately determined according to the composition of the adhesion layer 13, high refractive index layer 21, and low refractive index layer 22 formed on the plastic film 11 by passing between the film formation section 41 and the film formation roll 55. For example, SiO ｘ When forming a layer consisting of Si, argon gas and O as the reactive gas are used. ２ Use Nb. Also, for example,２ O ５ When forming a layer consisting of Nb or niobium oxide (NbO) as the target, ｘ Using ), argon gas and O as a reactive gas ２ This is used. In this way, when depositing an inorganic oxide film by sputtering, a target of the elemental metal element in the inorganic oxide or a target of the oxide of the said metal element can be used. When forming an oxynitride of Si, elemental Si is used as the target and O is used as the reactive gas. ２ and N ２ A method using, or using Si oxide as the target and N as the reactive gas. ２ , or, O ２ and N ２ The film can be formed using the following method.

[0089] In this embodiment, from the viewpoint of increasing the film deposition rate, it is preferable to use the magnetron sputtering method as the sputtering method. However, the sputtering method is not limited to the magnetron sputtering method, and a two-electrode sputtering method that utilizes plasma generated by DC glow discharge or high frequency, or a three-electrode sputtering method that adds a hot cathode may also be used.

[0090] The sputtering apparatus 1 includes an optical monitor (not shown) as a measurement unit for measuring optical properties after the adhesion layer 13, the high refractive index layer 21, and the low refractive index layer 22 have been formed. This allows the optical properties of the formed layers to be confirmed. If the sputtering apparatus 1 has, for example, two or more chambers, it is preferable to install an optical monitor in each chamber.

[0091] An example of an optical monitor (not shown) is one that measures the optical properties in the width direction of the layers formed on the hard coat layer 12 using an optical head that can scan in the width direction. When such an optical monitor is provided, for example, the optical thickness distribution in the width direction of each layer can be measured by measuring the peak wavelength of reflectance as an optical property and converting it to optical thickness. By measuring the optical properties using the optical monitor, it is possible to form an optical laminate having an optimal high refractive index layer 21 and a low refractive index layer 22 while adjusting the sputtering conditions in real time.

[0092] <Pretreatment device 2B> The pretreatment device 2B shown in Figure 5 comprises a chamber 32 with a predetermined reduced pressure atmosphere inside, a can roll 56, a plurality (two in Figure 5) of guide rolls 52, and a plasma discharge device 42. As shown in Figure 5, the can roll 56, the guide rolls 52, and the plasma discharge device 42 are installed inside the chamber 32. As shown in Figure 5, the chamber 32 is connected to the chamber 33 of the deposition device 3.

[0093] The can roll 56 and guide roll 52 transport the plastic film 11, with each layer formed up to the low refractive index layer 22, sent from the sputtering apparatus 1, at a predetermined transport speed, and send the plastic film 11 with the surface of the low refractive index layer 22 treated to the deposition apparatus 3. As the plasma discharge apparatus 42, for example, one similar to the pretreatment apparatus 2A can be used.

[0094] <Evaporation Apparatus> The evaporation apparatus 3 shown in Figure 5 comprises a chamber 33 whose interior is kept under a predetermined reduced pressure atmosphere, one or more vacuum pumps 51 (one in Figure 5) that discharge the gas from the chamber 33 to create a reduced pressure atmosphere, a plurality of guide rolls 52 (four in Figure 5), an evaporation source 43, and a heating device 63. As shown in Figure 5, the guide rolls 52 and the evaporation source 43 are installed inside the chamber 33. The chamber 33 is connected to the chamber 35 of the roll winding device 5.

[0095] The vapor deposition source 43 is positioned opposite the plastic film 11, whose surface has been treated with a low refractive index layer 22, which is being conveyed substantially horizontally between two adjacent guide rolls 52. The vapor deposition source 43 supplies an evaporated gas consisting of the material that will become the antifouling layer 14 onto the low refractive index layer 22. The orientation of the vapor deposition source 43 can be set arbitrarily. The heating device 63 heats the material that will become the antifouling layer 14 to its vapor pressure temperature. As the heating device 63, you can use resistance heating, heater heating, induction heating, or electron beam heating. In the resistance heating method, the container containing the antifouling material that will become the antifouling layer 14 is heated by current as a resistor. In the heater heating method, the container is heated by a heater placed on the outer circumference of the container. In the induction heating method, the container or the antifouling material is heated by electromagnetic induction from an induction coil installed externally.

[0096] The deposition apparatus 3 shown in Figure 5 includes a guide plate (not shown) for guiding the deposition material evaporated by the deposition source 43 to a predetermined position, a film thickness gauge (not shown) for observing the thickness of the antifouling layer 14 formed by deposition, a vacuum pressure gauge (not shown) for measuring the pressure inside the chamber 33, and a power supply (not shown). The guide plate may have any shape as long as it can guide the evaporated deposition material to the desired position. The guide plate does not need to be provided if it is not necessary. For example, an ion gauge can be used as the vacuum pressure gauge. For example, a high-frequency power supply can be used as the power supply.

[0097] <Roll Winding Device> The roll winding device 5 shown in Figure 5 comprises a chamber 35 whose interior is kept in a predetermined reduced-pressure atmosphere, one or more vacuum pumps 51 (one in Figure 5) that discharge the gas from the chamber 35 to create a reduced-pressure atmosphere, and a winding roll 54 and a guide roll 52 installed in the chamber 35. A plastic film 11 (optical laminate 102) with each layer up to the anti-fouling layer 14 formed on its surface is wound around the winding roll 54. The winding roll 54 and the guide roll 52 wind the optical laminate 102 at a predetermined winding speed. A carrier film may also be used if necessary.

[0098] The vacuum pump 51 provided in the manufacturing apparatus 50 shown in Figure 5 can be, for example, a dry pump, an oil rotary pump, a turbomolecular pump, an oil diffusion pump, a cryopump, a sputter ion pump, or a getter pump. The vacuum pump 51 can be appropriately selected or used in combination in each of the chambers 31, 32, 33, 34, and 35 to create the desired reduced pressure state.

[0099] The vacuum pump 51 only needs to be able to maintain both the chamber 31 of the sputtering apparatus 1 and the chamber 33 of the deposition apparatus 3 in a desired reduced pressure state, and the installation location and number of vacuum pumps 51 in the manufacturing apparatus 50 are not particularly limited. In addition, in the manufacturing apparatus 50 shown in Figure 5, the roll unwinding device 4, the pretreatment device 2A, the sputtering apparatus 1, the pretreatment device 2B, the deposition apparatus 3, and the roll winding device 5 are connected. For this reason, the vacuum pump 51 may be installed in each of the chambers 31, 32, 33, 34, and 35, or it may be installed in only some of the chambers 31, 32, 33, 34, and 35, as long as it can maintain both the chamber 31 of the sputtering apparatus 1 and the chamber 33 of the deposition apparatus 3 in a desired reduced pressure state.

[0100] Next, a method for manufacturing the optical laminate 102 using the manufacturing apparatus 50 shown in Figure 5 will be described. First, an unwinding roll 53, around which a plastic film 11 with a hard coat layer 12 formed on its surface is wound, is placed in the chamber 34 of the roll unwinding device 4. Then, the unwinding roll 53 and the guide roll 52 are rotated to feed the plastic film 11 with the hard coat layer 12 formed on its surface to the pretreatment device 2A at a predetermined transport speed.

[0101] Next, a first surface treatment step is performed in the chamber 32 of the pretreatment device 2A as a pretreatment for the surface on which the adhesion layer 13 will be formed. In this embodiment, the first surface treatment step is performed on the plastic film 11 on which the hard coat layer 12 is formed. In the first surface treatment step, the can roll 56 and the guide roll 52 are rotated to transport the plastic film 11 on which the hard coat layer 12 is formed at a predetermined transport speed, and the surface of the hard coat layer 12 running on the can roll 56 is treated.

[0102] As a surface treatment method for the hard coat layer 12, for example, glow discharge treatment, plasma treatment, ion etching, and alkaline treatment can be used. Among these, glow discharge treatment is preferred because it allows for large-area treatment. Glow discharge treatment can be performed at a treatment intensity of, for example, 0.1 kWh to 10 kWh. By performing glow discharge treatment on the surface of the hard coat layer 12, the surface of the hard coat layer 12 is roughened at the nano level, and substances with weak bonding forces present on the surface of the hard coat layer 12 are removed. As a result, the adhesion between the hard coat layer 12 and sputtered films such as the adhesion layer 13 formed on the hard coat layer 12 is improved.

[0103] Next, the adhesion layer formation process, the high refractive index layer formation process, and the low refractive index layer formation process are performed in the chamber 31 of the sputtering apparatus 1. Specifically, the film formation roll 55 and the guide roll 52 are rotated to transport the plastic film 11 with the hard coat layer 12 formed on it at a predetermined transport speed, and the adhesion layer 13, the high refractive index layer 21, and the low refractive index layer 22 are formed on the hard coat layer 12 as it travels on the film formation roll 55.

[0104] In this embodiment, an adhesion layer 13 is formed by sputtering while changing the target material installed in each film-forming section 41, or the type and flow rate of the reactive gas supplied from the gas supply section, and a high refractive index layer 21 and a low refractive index layer 22 are laminated on top of it. That is, the adhesion layer formation process, the high refractive index layer formation process, and the low refractive index layer formation process are performed continuously within the sputtering apparatus 1. The pressure during film formation of the adhesion layer 13 is, for example, between 0.1 Pa and 2.0 Pa, preferably 1.1 Pa or less, more preferably 0.6 Pa or less, and particularly preferably 0.2 Pa or less. The pressure during film formation of the high refractive index layer 21 is, for example, between 0.2 Pa and 1.0 Pa, preferably 0.3 Pa and 0.6 Pa. The pressure during film formation of the low refractive index layer 22 is, for example, between 0.1 Pa and 1.0 Pa, preferably 0.2 Pa and 0.4 Pa. The number of film-forming sections 41 can be set according to the number of films to be formed. In the high refractive index layer formation process, it is preferable to form the high refractive index layer so that its physical thickness is in the range of 2 nm to 10 nm, in the range of 3 nm to 8 nm, and in the range of 4 nm to 7 nm. In this way, in the low refractive index layer formation process, it is preferable to form the low refractive index layer so that its physical thickness is in the range of 60 nm to 140 nm, in the range of 80 nm to 135 nm, and in the range of 90 nm to 130 nm. Furthermore, in the adhesion layer formation process, the high refractive index layer formation process, and the low refractive index layer formation process, it is preferable to form the film so that the sum of the physical thicknesses (total thickness) of the adhesion layer 13, the high refractive index layer 21, and the low refractive index layer 22 is, for example, 70 nm to 150 nm, in the range of 80 nm to 145 nm, and in the range of 100 nm to 140 nm.

[0105] When the adhesion layer 13, the high refractive index layer 21, and the low refractive index layer 22 are continuously laminated by sputtering, the target material may be changed during the deposition of the adhesion layer 13, the high refractive index layer 21, and the low refractive index layer 22. Alternatively, for example, one type of material may be used as the target, and by changing the oxygen (reactive gas) flow rate during sputtering, layers made of the target material and layers made of oxides of the target material may be alternately formed to form the adhesion layer 13, the high refractive index layer 21, and the low refractive index layer 22.

[0106] The sputtering pressure for the adhesion layer, high refractive index layer, and low refractive index layer is adjusted as appropriate, taking into account productivity and film quality. However, high production rates can be achieved by sputtering at the pressures described above.

[0107] Subsequently, the plastic film 11, on which the adhesion layer 13, high refractive index layer 21, and low refractive index layer 22 are formed on the hard coat layer 12, is fed to the pretreatment device 2B by the rotation of the film-forming roll 55 and guide roll 52. Next, a second surface treatment step is performed in the chamber 32 of the pretreatment device 2B as a pretreatment for the surface on which the antifouling layer 14 will be formed. In the second surface treatment step, the can roll 56 and guide roll 52 are rotated to transport the plastic film 11, on which each layer up to the low refractive index layer 22 is formed, at a predetermined transport speed, and a discharge treatment is performed on the surface of the low refractive index layer 22 as it travels on the can roll 56.

[0108] Surface treatment methods include, for example, glow discharge treatment, plasma treatment, ion etching, and alkaline treatment. Among these, glow discharge treatment is preferred because it allows for treatment of large areas.

[0109] When a discharge treatment is performed on the surface of the low refractive index layer 22, the surface of the low refractive index layer 22 is etched, and the surface state changes.

[0110] The cumulative power during glow discharge treatment is 130 W・min / m ２ More than 2000W・min / m ２The following is preferable. In this embodiment, the cumulative power is the value obtained by dividing the product of the glow discharge output and irradiation time irradiated onto the low refractive index layer 22 during the discharge process by the unit area.

[0111] Subsequently, the plastic film 11 with the treated surface of the low refractive index layer 22 is fed to the vapor deposition apparatus 3 by the rotation of the can roll 56 and guide roll 52. Next, the antifouling layer formation process is performed in the chamber 33 of the vapor deposition apparatus 3. In this embodiment, the plastic film 11 with the treated surface of the low refractive index layer 22 obtained in the second surface treatment process is continuously subjected to the antifouling layer formation process while being maintained under reduced pressure without being exposed to the atmosphere. In the antifouling layer formation process, the guide roll 52 is rotated to transport the plastic film 11 at a predetermined transport speed, and the vapor deposition source 43 is deposited on the surface of the low refractive index layer 22.

[0112] In this embodiment, for example, an antifouling material made of a fluorine-based organic compound that will become the antifouling layer 14 is heated to its vapor pressure temperature by a heating device 63, and the resulting evaporated gas is supplied from a deposition source 43 under a reduced pressure environment to adhere to the material, thereby forming the antifouling layer 14 by vacuum deposition. The pressure when performing vacuum deposition of the antifouling layer 14 is preferably 0.05 Pa or less, more preferably 0.01 Pa or less, and particularly preferably 0.001 Pa or less. When the pressure during vacuum deposition is a reduced pressure of 0.05 Pa or less, the mean free path of the film-forming molecules is longer and the deposition energy is higher, so a denser and better antifouling layer 14 can be obtained.

[0113] By the above method, an optical laminate 102 is obtained in which an antifouling layer 14 is formed by vacuum deposition on an adhesion layer 13, a high refractive index layer 21, and a low refractive index layer 22 formed by sputtering.

[0114] Subsequently, the optical laminate 102 is fed to the roll winding device 5 by the rotation of the guide roll 52. Then, within the chamber 35 of the roll winding device 5, the optical laminate 102 is wound onto the winding roll 54 by the rotation of the winding roll 54 and the guide roll 52.

[0115] In this embodiment, it is preferable to perform the adhesion layer formation process, the high refractive index layer formation process, the low refractive index layer formation process, and the antifouling layer formation process continuously under reduced pressure. In particular, when the optical laminate 102 is continuously manufactured as a roll-to-roll roll, as in the manufacturing method of this embodiment using the manufacturing apparatus 50 shown in Figure 5, it is even more preferable to perform the adhesion layer formation process, the high refractive index layer formation process, the low refractive index layer formation process, and the antifouling layer formation process continuously in line while maintaining a reduced pressure state. In line means that the antifouling layer formation process is performed without exposing the molded body formed in the adhesion layer formation process, the high refractive index layer formation process, and the low refractive index layer formation process to the atmosphere. With this formation method, the formation of a natural oxide film on the low refractive index layer 22 before the antifouling layer 14 is formed is suppressed. In addition, contamination such as foreign matter when winding the roll can be prevented from adhering to the low refractive index layer 22 and hindering the adhesion between the low refractive index layer 22 and the antifouling layer 14. Therefore, compared to the case where the plastic film 11 with each layer up to the low refractive index layer 22 formed is removed from the chamber under reduced pressure, and then placed back into the chamber to perform the antifouling layer formation process under reduced pressure, this method provides better adhesion between the low refractive index layer 22 and the antifouling layer 14, resulting in an optical laminate with superior transparency and improved production efficiency.

[0116] In this embodiment, when the first surface treatment step, the adhesion layer formation step, the high refractive index layer formation step, the low refractive index layer formation step, the second surface treatment step, and the antifouling layer formation step are carried out continuously while maintaining the optical laminate in the process of manufacturing under reduced pressure, the reduced pressure conditions in the chambers of, for example, the sputtering apparatus and the deposition apparatus may differ, as long as they do not interfere with each manufacturing step.

[0117] In this embodiment, it is preferable to measure the film formation results over time using a measuring instrument in one or more of the following steps: the adhesion layer formation step, the high refractive index layer formation step, the low refractive index layer formation step, and the anti-fouling layer formation step, and to feed back the results to the conditions of the subsequent manufacturing step. This makes it easier to optimize the characteristics of the entire optical laminate and makes the in-plane characteristics of the optical laminate uniform. It is also possible to feed back the manufacturing conditions in the same step using the measuring instrument. In this case, the layer formed in that step will have uniform and stable characteristics.

[0118] In this embodiment, the case in which the second surface treatment step is performed was described as an example, but the second surface treatment step may be performed as needed or may not be performed at all. Even when the second surface treatment step is not performed, it is preferable to perform the adhesion layer formation step, the high refractive index layer formation step, the low refractive index layer formation step and the antifouling layer formation step continuously under reduced pressure.

[0119] In the manufacturing method of this embodiment, the high refractive index layer formation process is carried out under a vacuum of 0.3 Pa to 1.0 Pa, thereby enabling the formation of the high refractive index layer 21 while achieving both good film quality and productivity. Therefore, even if the physical thickness of the high refractive index layer 21 is an extremely thin layer of 10 nm or less, by providing it between the transparent plastic substrate 10B and the low refractive index layer 22, the synergistic effect of its density and labyrinth effect results in a remarkably superior water vapor permeation suppression function compared to the case where the low refractive index layer is provided as a single layer on the transparent plastic substrate 10B. Furthermore, as the high refractive index layer 21 becomes denser, the water vapor permeability decreases and abrasion resistance improves. In addition, by ensuring that the film thickness of the antifouling layer is greater than a predetermined thickness, sufficient scratch resistance and alkali resistance can be secured.

[0120] In this embodiment, the example described was the continuous production of an optical laminate 10 using a roll-to-roll method with the manufacturing apparatus 50 shown in Figure 5, which includes a pretreatment apparatus 2A, a sputtering apparatus 1, a pretreatment apparatus 2B, a vapor deposition apparatus 3, a roll unwinding apparatus 4, and a roll winding apparatus 5. However, the manufacturing apparatus for producing the optical laminate 102 is not limited to the manufacturing apparatus 50 shown in Figure 5. For example, a manufacturing apparatus may be used that does not include the pretreatment apparatus 2A and pretreatment apparatus 2B, but in which the roll unwinding apparatus 4, the sputtering apparatus 1, the vapor deposition apparatus 3, and the roll winding apparatus 5 are connected in that order.

[0121] The manufacturing apparatus 50 shown in Figure 5 may include a pre-treatment chamber (not shown) between the chamber 33 of the vapor deposition apparatus 3 and the chamber 32 of the pre-treatment apparatus 2B for cleaning the surface of the low refractive index layer 22 on which the antifouling layer 14 is formed. The manufacturing apparatus 50 shown in Figure 5 may also include a post-treatment chamber (not shown) between the chamber 33 of the vapor deposition apparatus 3 and the chamber 35 of the roll winding apparatus 5 for cooling and / or inspecting the plastic film 11 on which each layer up to the antifouling layer 14 has been formed.

[0122] The manufacturing apparatus 50 shown in Figure 5 may include a hard coat layer forming device between the roll unwinding device 4 and the sputtering device 1 for forming a hard coat layer 12 on the surface of the plastic film 11. In this case, not only the adhesion layer 13, the high refractive index layer 21, the low refractive index layer 22, and the anti-fouling layer 14, but also the hard coat layer 12 can be manufactured continuously using a roll-to-roll method, which is preferable.

[0123] In this embodiment, the example described was that the adhesion layer formation process, the high refractive index layer formation process, and the low refractive index layer formation process are performed using a sputtering apparatus, and the antifouling layer formation process is performed using a vapor deposition apparatus. However, if the second surface treatment process is not performed, the high refractive index layer formation process, the low refractive index layer formation process, and the antifouling layer formation process may be performed in the same apparatus (in one chamber).

[0124] In the optical laminate 102 of this embodiment, various layers may be provided on the surface facing the surface on which the high refractive index layer 21 of the transparent plastic substrate 10B is formed, as needed. For example, an adhesive layer used for bonding with other members may be provided. Alternatively, another optical film may be provided via this adhesive layer. Examples of other optical films include polarizing films, phase difference compensation films, films that function as half-wave plates or quarter-wave plates.

[0125] Furthermore, a layer having functions such as anti-reflection, selective reflection, anti-glare, polarization, phase difference compensation, viewing angle compensation or expansion, light guidance, diffusion, brightness enhancement, hue adjustment, and conductivity may be directly formed on the opposing surfaces of the transparent plastic substrate 10B.

[0126] Thus, according to the optical laminate of this embodiment, by providing an extremely thin predetermined high refractive index layer 21 between the transparent plastic substrates 10A and 10B and the low refractive index layer 22, the high refractive index layer 21 is thin, making it possible to reduce manufacturing costs while ensuring sufficient water vapor transmission suppression function and good optical properties. Specifically, the optical laminate of this embodiment has a water vapor transmission rate of 0.05 (g / m³) under conditions of 40°C and 90% relative humidity. ２ / day) or more 0.5 (g / m ２ ( / day) or less, and 0.05 (g / m³) ２ / day) or more 0.25 (g / m ２ It may also be less than or equal to / day.

[0127] Furthermore, according to the optical laminate of this embodiment, the optical properties are improved by providing a high refractive index layer 21 and a low refractive index layer 22, as described above. Specifically, the optical laminate of this embodiment has, for example, a luminous reflectance Y (SCI) of 3.5% or less, preferably 3.0% or less, more preferably 2.5% or less, and even more preferably 2.0% or less. Also, the a CIE-LAB color system of the total reflected light when light with a wavelength of 380 nm to 780 nm from a standard light source D65 is incident on it. ＊ For example, if the value is -3 ≤ a ＊ ≤ 30 and 0 ≤ a ＊Preferably, ≤ 26, and 0 ≤ a ＊ It is more preferable that ≤ 12, and 0 ≤ a ＊ It is even more preferable that ≤ 10, and 0 ≤ a ＊ It is particularly preferable that the value be ≤ 8. ＊ For example, if the value is -30 ≤ b ＊ ≤ 18 and -15 ≤ b ＊ ≤ 0 or 0 ≤ b ＊ Preferably, ≤ 16, and -12 ≤ b ＊ It is more preferable that ≤ 0, and -10 ≤ b ＊ ≤ 0 or -0 ≤ b ＊ It is even more preferable that ≤ 10. When provided on the outermost surface of an image display device, etc., it is preferable that the reflected light does not easily become discolored, so the optical laminate according to this embodiment has a positive a within such predetermined range. ＊ The value of b is positive. ＊ By having a value, the color of the reflected light can be made closer to neutral when used in daylight conditions such as sunlight. In addition, the optical laminate has a positive a within a predetermined range. ＊ Value, negative b ＊ Having a value makes it difficult to perceive the color of reflected light, especially in low-light environments. Furthermore, in the optical laminate according to this embodiment, the sheet resistance value on the anti-fouling layer 14 side is, for example, 10 ８ Ω / □ or greater, and 10 ９ It is preferable that the ratio is Ω / □ or greater, and 10 １０ It is more preferable that the value is Ω / □ or greater. In this embodiment, the sheet resistance value on the antifouling layer 14 side of the optical laminate refers to the sheet resistance value measured by placing a probe on the center of the planar view of the surface on the antifouling layer side of the optical laminate. Having such a sheet resistance value makes the optical laminate suitable for a touch panel.

[0128] [Article] The article of this embodiment is, for example, a liquid crystal display panel, an organic EL display panel, etc., on which the above-mentioned optical laminate is provided on the display surface of an image display unit. Furthermore, the article is not limited to an image display device, but can be anything to which the optical laminate can be applied, such as goggles on which the optical laminate of this embodiment is provided on the surface, the light-receiving surface of a solar cell, the screen of a smartphone or the display of a personal computer, an information input terminal, a tablet terminal, an AR (augmented reality) device, a VR (virtual reality) device, an electronic display board, the surface of a glass table, amusement machines, operation support devices for aircraft or trains, navigation systems, instrument panels, the surface of an optical sensor, etc. For example, the optical laminate may be bonded to the curved surface of an article having a curved surface. Typically, the article of this embodiment is one on which the optical laminate is installed on the surface of a touch panel.

[0129] Figure 6 is a perspective view showing an example of the configuration of a touch panel to which an optical laminate is attached according to one embodiment of the present invention. The touch panel 200 shown in Figure 6 has a bezel 202 and a display unit 201 surrounded by the bezel 202. An optical laminate 100 is attached to the display unit 201 of the touch panel 200.

[0130] In the optical laminate according to the above embodiment, the layers provided on the transparent plastic substrates 10A and 10B and composed of inorganic oxides include a high refractive index layer 21 and a low refractive index layer 22. Preferably, the layers consist of a high refractive index layer 21 and a low refractive index layer 22, or a medium refractive index layer 25A, a high refractive index layer 21 and a low refractive index layer 22, or an adhesion layer 13, a high refractive index layer 21, a medium refractive index layer 25B and a low refractive index layer 22, with a configuration consisting of a high refractive index layer 21 and a low refractive index layer 22 being more preferable.

[0131] Furthermore, the upper and / or lower limits of the numerical ranges described herein can be arbitrarily combined to define a preferred range. For example, the upper and lower limits of the numerical ranges can be arbitrarily combined to define a preferred range, the upper limits of the numerical ranges can be arbitrarily combined to define a preferred range, and the lower limits of the numerical ranges can be arbitrarily combined to define a preferred range.

[0132] Furthermore, throughout this disclosure, singular expressions should be understood to include the concept of their plural form unless otherwise specified. Therefore, singular articles (for example, "a," "an," and "the" in English) should be understood to include the concept of their plural form unless otherwise specified.

[0133] Although embodiments of the present invention have been described above, 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 forms, and various omissions, substitutions, additions, and modifications can be made without departing from the spirit of the invention. For example, in an embodiment of the method for manufacturing an optical laminate, the configuration described in the embodiment of the optical laminate can be referenced. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0134] The following describes embodiments of the present invention. The optical laminates in the following embodiments are examples of optical laminates that function as optical films with water vapor transmission suppression function, and the present invention is not limited to these examples.

[0135] [Example 1] First, a transparent substrate (TAC) with a thickness of 80 μm was prepared. Then, as a hard coat layer formation step, the photocurable resin composition shown in Table 1 was applied to the transparent substrate using a bar coater, and the resin composition was photopolymerized and dried to form a hard coat layer with a physical thickness of 4 μm, and a roll-shaped resin film was prepared.

[0136]

[0137] Next, as an adhesion layer formation step, a layer of SiO with a physical thickness of 5 nm is formed on the hard coat layer. ２ An adhesion layer was formed using the following: A Si target was used, and the pressure was set to 0.2 Pa, with Ar gas and O ２ This was performed using a reactive sputtering method with a gas mixture.

[0138] Next, as a high refractive index layer formation step, a layer of Nb with a physical thickness of 6 nm is formed on the adhesion layer.２ O ５ The high refractive index layer formation process used an Nb target, a pressure of 0.5 Pa, Ar gas and O ２ This was performed using a reactive sputtering method with a gas mixture.

[0139] Next, as a low refractive index layer formation step, a SiO layer with a physical thickness of 100 nm is formed on the high refractive index layer. ２ The low refractive index layer formation process used a Si target, a pressure of 0.2 Pa, Ar gas and O ２ The process was carried out by reactive sputtering using a gas mixture. Next, as an antifouling layer formation step, an antifouling layer with an optical thickness of 5 nm was formed on the low refractive index layer, consisting of an alkoxysilane compound having a perfluoropolyether group. In this way, the optical laminate of Example 1 was fabricated, in which a hard coat layer, an adhesion layer, a high refractive index layer, a low refractive index layer, and an antifouling layer were sequentially formed on the TAC substrate.

[0140] [Examples 2 to 4] SiO2 layer with low refractive index ２ An optical laminate was fabricated using the same method as in Example 1, except that the physical thickness of the film was changed.

[0141] [Examples 5 to 7] High refractive index layer Nb ２ O ５ An optical laminate was fabricated using the same method as in Example 4, except that the physical thickness of the film was changed.

[0142] [Example 8] The transparent substrate was changed from TAC to PET (thickness 80 μm), the hard coat layer formation process was omitted, and the low refractive index layer was SiO ２ The film and its physical thickness and high refractive index layer are Nb ２ O ５ An optical laminate was fabricated using the same method as in Example 1, except that the physical thickness of the film was changed.

[0143] [Examples 9 to 11] For Examples 9 to 11, optical laminates were fabricated in the same manner as in Example 5, except that the materials and physical thickness constituting the high refractive index layer were changed, and evaluation was performed in the same manner as in Example 1. For SiON, a Si target was used, with a pressure of 0.2 Pa, Ar gas, and O２ Gas, N ２ This was performed using a reactive sputtering method with a gas mixture.

[0144] [Comparative Examples 1 to 6] In Comparative Examples 1 to 5, optical laminates were fabricated and evaluated in the same manner as in Example 9, except that a low refractive index layer with a physical thickness of 20 nm to 140 nm was provided on a transparent plastic substrate, and no layer corresponding to a high refractive index layer was provided. In Comparative Example 6, no layer corresponding to a low refractive index layer was provided on a transparent plastic substrate, and an Nb layer with a physical thickness of 30 nm was provided. ２ O ５ An optical laminate was fabricated using the same method as in Comparative Example 1, except that a special feature was added.

[0145] (Water vapor transmission rate) The optical laminates of the above examples and comparative examples have a cell area of ​​50 cm². ２ The water vapor transmission rate (WVTR) was measured in a test cell using a water vapor transmission rate measuring device (MOCON Corporation, product name: PERMATRAN-W 3 / 34G) at a temperature of 40°C and a relative humidity of 90% (g / m³). ２ The value (per day) was measured.

[0146] (Luminous Reflectance Y (SCI)) An optical laminate was cut to a size of 50 mm square to serve as an evaluation sample. The film substrate side of the evaluation sample (the side opposite to the adhesive layer formation side) was attached to the surface of a black acrylic plate via an acrylic transparent adhesive to remove back surface reflection and create a test specimen in which only surface reflection could be measured. The spectral reflectance of the total reflected light (measurement wavelength: 380 nm to 780 nm, incident angle: 8°, 2-degree field of view) was measured on the test specimen using a spectrophotometer (Hitachi High-Tech Science Corporation, product name: UH4150). The lumenable reflectance Y (SCI) of the object color due to reflection in the XYZ color system specified in JIS Z8701 was calculated using the measured spectral reflectance and the relative spectral distribution of the CIE standard illuminant D65 (standard light source D65).

[0147] (Reflected Hue) The reflected hue of total reflected light is obtained from the XYZ color system obtained in the calculation process of the luminous reflectance Y, and is converted by the following formula (1) to the chromaticity (chromatic index) a in the CIE-Lab color system. ＊ and b ＊was obtained. In the following formula (1), X, Y, and Z are the tristimulus values in the XYZ colorimetric system of the sample, and X ｎ , Y ｎ , Z ｎ are the tristimulus values of the perfect diffusing reflection surface.

[0148]

[0149] (Total light transmittance) The total light transmittance was measured using NDH5000SP (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K-7105.

[0150] (Scratch resistance) Using a friction tester type I compliant with JIS L0849, a friction body was horizontally reciprocated along the surface of the antifouling layer of the optical laminate (test piece) to obtain a test piece. Steel wool (No. 0000, manufactured by Bonsuta Co., Ltd.) was used as the friction body. The test settings were a load of 1000 g / cm ２ , a sliding distance of 50 mm, a sliding speed of 60 rpm (1 reciprocation / second), and a sliding number of 200 times (100 reciprocations). The scratch resistance test was performed by this operation. In the scratch resistance test, visual inspection was performed, and those with only discoloration or less than 3 linear scratches were evaluated as "A", and those with 3 or more linear scratches were evaluated as "B".

[0151] (Measurement of sheet resistance) The sheet resistance value of the fabricated optical laminate was measured using a resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., device name: Hi-Rester UP (MCP-HT450 type)). As the measurement conditions, the probe was applied to the center of the surface of the antifouling layer side of the optical laminate in plan view, and the measurement was performed by applying an electric current at 500 V for 10 seconds.

[0152] The conditions and results of the above Examples and Comparative Examples are summarized in Tables 2 to Table 4.

[0153]

[0154]

[0155]

[0156] As shown in Table 4, a single layer of SiO is formed on a plastic transparent substrate ２When a film was provided, it was confirmed that the greater the thickness, the higher the tendency of the water vapor permeability suppression function. Also, in Comparative Examples 1 to 5, all showed values of water vapor permeability exceeding 0.5 (g / m ２ / day). In particular, Comparative Example 5 having a single-phase SiO ２ film with the same thickness as that of the one with the largest total thickness of the high refractive index layer and the low refractive index layer among the examples had a water vapor permeability of about 0.8 (g / m ２ / day). This value is equivalent to the case where the thickness is 90 nm, and it is presumed that there is a limit to the obtained water vapor permeability when a single-layer SiO ２ film is provided on a plastic transparent substrate. As shown in Tables 2 to 4, in Examples 1 to 5 in which an ultrathin Nb ２ film was formed between the plastic transparent substrate and the SiO ２ film and the overall thickness was equivalent to that of Comparative Examples 1 to 5, all had a water vapor permeability of 0.2 or less (g / m ５ / day), and it was confirmed that significantly excellent water vapor permeability was obtained. ２ / day), and it was confirmed that significantly excellent water vapor permeability was obtained.

[0157] Incidentally, in the configuration in which a Nb ２ film and an antifouling layer that can be used as a high refractive index layer were provided in this order on an adhesion layer as in Comparative Example 6, the visual reflectance was high and antireflection performance could not be obtained. One of the reasons for this is considered to be that no other layer was interposed between the antifouling layer and the Nb ５ film, and the adhesion of these layers was insufficient. ２ O ５ film, and the adhesion of these layers was insufficient.

[0158] Also, the sheet resistance values of the optical laminate of Examples 1 to 11 and Comparative Examples 1 to 6 were all 10 １２ (Ω / □) or more, and it was confirmed that they were insulators.

[0159] (Total Reflectance Spectrum Measurement) The optical properties of the optical laminates of Example 4 and Comparative Example 5 were evaluated. Specifically, the total reflectance (SCI) spectrum was determined by measuring it using the same method as the measurement method described above for (Luminous Reflectance Y (SCI)). Figure 7 is a graph showing the reflectance of the optical laminates of Example 4 and Comparative Example 5 for each wavelength in the range of 380 nm to 780 nm.

[0160] As shown in Figure 7, the optical laminate of Comparative Example 5 had a reflectivity of approximately 4% regardless of the wavelength of the incident light from 380 nm to 780 nm. Although not shown in the figures, Comparative Examples 1 to 6 were all made of SiO, similar to Comparative Example 5. ２ Regardless of the film thickness and incident wavelength, the reflectivity was approximately 4%. In contrast, the optical laminate of Example 4 showed a slightly higher reflectivity in the short wavelength region, but exhibited a reflectivity of 3% or less at wavelengths exceeding 470 nm, such as 550 nm. It was confirmed that it showed a lower reflectivity than the comparative example at most wavelengths in the visible light region. In other words, it can be said that the optical laminate according to this embodiment also improves optical properties.

[0161] 10A, 10B: Transparent plastic substrate, 11: Plastic film, 12: Hard coat layer, 13: Adhesion layer, 14: Anti-fouling layer, 21: High refractive index layer, 22: Low refractive index layer, 25A, 25B: Medium refractive index layer, 101, 102, 103, 104: Optical laminate

Claims

1. A transparent plastic substrate, a high refractive index layer provided on the transparent plastic substrate, and a low refractive index layer provided on the high refractive index layer, wherein the physical thickness of the high refractive index layer is 2 nm or more and 10 nm or less, the physical thickness of the low refractive index layer is 60 nm or more and 140 nm or less, and the water vapor transmission rate under conditions of 40°C and 90% relative humidity is 0.5 g / m³ ２ An optical laminate that is less than or equal to / day.

2. The optical laminate according to claim 1, wherein the total light transmittance is 90% or more.

3. The optical laminate according to claim 1 or 2, wherein the high refractive index layer is mainly composed of an oxide of Nb and Ti or both.

4. The optical laminate according to claim 1 or 2, wherein the high refractive index layer is mainly composed of an Nb oxide represented by NbOx.

5. The low refractive index layer is SiO ２ Al ２ O ３ The optical laminate according to claim 1 or 2, comprising either and SiON.

6. The optical laminate according to claim 1 or 2, comprising: a transparent plastic substrate; a high refractive index layer provided on the transparent plastic substrate; a low refractive index layer provided on the high refractive index layer; and an anti-fouling layer provided in contact with the low refractive index layer.

7. The optical laminate according to claim 6, comprising the transparent plastic substrate, the high refractive index layer, the low refractive index layer, and the anti-fouling layer.

8. The optical laminate according to claim 6, further comprising a medium refractive index layer, which is made of a composition exhibiting a refractive index between the refractive indices of compositions contained as main components in the two layers in contact with the transparent plastic substrate and the high refractive index layer, and the high refractive index layer and the low refractive index layer, wherein the optical laminate comprises the transparent plastic substrate, the high refractive index layer, the low refractive index layer, the antifouling layer, and the medium refractive index layer.

9. The plastic transparent substrate has a plastic film which is a TAC film or a PET film. The high refractive index layer and the low refractive index layer are sputtered films. The visual reflectance is 3% or less. The sheet resistance value on the antifouling layer side is 10 ８ Ω / □ or more. When light with a wavelength of 380 nm or more and 780 nm or less is incident by a standard light source D65, the a ＊ value in the CIE-LAB color system of the total reflected light is -3 ≤ a ＊ ≤ 30, and the b ＊ value is -30 ≤ b ＊ ≤ 18. The optical laminate according to claim 6.

10. The optical laminate according to claim 9, wherein the transparent plastic substrate comprises the plastic film, a hard coat layer, and an adhesion layer.

11. An article comprising the optical laminate according to claim 1 or 2.

12. The article according to claim 11, wherein the optical laminate is installed on the surface of a touch panel.

13. A method for manufacturing an optical laminate, comprising: a high refractive index layer formation step of forming a high refractive index layer with a physical thickness of 2 nm to 10 nm on a transparent plastic substrate by sputtering; and a low refractive index layer formation step of forming a low refractive index layer with a physical thickness of 60 nm to 140 nm on the high refractive index layer by sputtering, wherein the pressure in the high refractive index layer formation step is 0.3 Pa or higher.

14. The method for manufacturing an optical laminate according to claim 13, wherein the pressure in the low refractive index layer formation step is 0.1 Pa or more.

15. In the high refractive index layer formation step, using an Nb target or a niobium oxide (NbOx) target as the high refractive index layer, Nb ２ O ５ Forming a low refractive index layer, and in the low refractive index layer formation step, using a Si target, the low refractive index layer is formed as SiO ２ A method for manufacturing an optical laminate according to claim 13 or 14, which forms the optical laminate.

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