Laminated bodies and methods for manufacturing laminated bodies

Abstract

The low refractive index film 10 of the present invention comprises at least a first layer 11 and a second layer 12. The first layer 11 is adjacent to the substrate 20. The low refractive index film 10 has a refractive index of 1.01 to 1.30. Each of the first layer 11 and the second layer 12 contains hollow particles 13 and an adhesive 14. The first layer 11 satisfies at least one of the conditions (I) and (II) below, for example. (I) 1000 nm in the cross-section of the first layer 11 The number density ρv1 of the voids with a cross-sectional area of ​​2 or more is 5 / μm. 2 or more 100 / μm 2 or less. (II) The ratio of the cross-sectional area of ​​the void 15 to the total cross-sectional area of ​​the first layer 11 is more than 5% and less than 70%.

Description

Technical Field

[0001] The present invention relates to a low refractive index film, a laminate, an optical element, a windproof material, and a display device. Prior Art

[0002] In the past, an anti-reflection film was known that suppresses the reflection of light from the surface of a transparent object or substrate by applying a material having a predetermined refractive index to the object. In particular, in fields or applications such as lenses or filters, windows or structural materials used in buildings, windshields for automobiles, helmets or goggles, etc., it is important to form an anti-reflection film on the surface in order to suppress the reflected light from the surface and increase the amount of light that penetrates the object or substrate. For example, the reflectivity of one surface of glass is usually about 4 to 5%. Therefore, for an object made of plate-shaped glass, the overall reflectivity considering the reflection on the front and the reflection on the back can be 8 to 10%. The reflected light from the surface of a glass lens used with a camera or other imaging device may cause undesirable phenomena such as ghosting or flare by repeatedly reflecting or refracting in the device or on other lens surfaces. Therefore, it is important to form an anti-reflection film on the surface of an object or substrate that performs functions such as light penetration or refraction to suppress the reflection of the surface.

[0003] According to the theory of light reflection, it is expected that the reflected light can be easily reduced by making the refractive index of the material constituting the anti-reflection film smaller than the refractive index of the coated substrate (ideally, the square root of the refractive index of the coated article). However, there is no material composed of a single substance with a sufficiently low refractive index. Conventionally, there are multilayer film structures in which multiple layers with different refractive indices are stacked, or structures including a film called a low refractive index film, which contains a substance that produces an effect of lowering the refractive index of hollow particles, etc., thereby lowering the refractive index of the entire film.

[0004] For example, Patent Document 1 describes an antireflection film formed by bonding hollow particles with an adhesive. The adhesive contains voids with a cross-sectional area of ​​less than 1000 nm2 and voids with a cross-sectional area of ​​1000 nm2 or more. The number of voids with a cross-sectional area of ​​1000 nm2 or more contained in the adhesive is less than 10 / μm2 relative to the cross-sectional area of ​​the adhesive 1 μm2. In the embodiment, an antireflection film is formed on a glass substrate BK7, and the refractive index of the antireflection film is 1.27.

[0005] In addition, Patent Document 2 describes an optical element having an antireflection film formed on a substrate. The antireflection film includes a low refractive index layer formed by bonding hollow microparticles having pores inside with an adhesive. The low refractive index layer is composed of a first layer as the outermost layer and a second layer adjacent to the first layer and located on the side of the substrate. The filling rate of the adhesive in the first layer is lower than the filling rate of the adhesive in the second layer. Prior Art Literature Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-108320 Patent Document 2: Japanese Patent Application Publication No. 2013-033124 Summary of the invention

[0007] [Problems to be solved by the invention] According to Patent Document 1, the quantitative state of the voids in the portion of the antireflection film located near the glass substrate BK7 is not stable. On the other hand, according to Patent Document 2, the filling rate of the binder of the second layer is high, and there is no record of the presence of voids in the second layer. Therefore, the refractive index of the second layer is likely to become higher.

[0008] Based on this situation, the techniques described in Patent Documents 1 and 2 have room for further study from the perspective of improving antireflection performance. Therefore, the present invention provides a new low refractive index film that is advantageous from the perspective of exerting higher antireflection performance. [Technical means to solve the problem]

[0009] The present invention provides a low refractive index film, which is having at least a first layer and a second layer adjacent to the first layer, and With a refractive index of 1.01 or more and 1.30 or less, Each of the first layer and the second layer contains hollow particles and a binder. The first layer has a thickness that is less than half of the thickness of the low refractive index film and less than 200 nm. The first layer has a gap that satisfies at least one of the following conditions (I) and (II): (I) the number density of the voids having a cross-sectional area of ​​1000 nm 2 or more in the cross-section of the first layer is 5 / μm 2 or more and 100 / μm 2 or less; (II) A ratio of a cross-sectional area of ​​the voids in the cross section to an area of ​​the cross section of the first layer is 5% to 70%.

[0010] In addition, the present invention provides a laminated body, The invention comprises a substrate and the low refractive index film in sequence, and The first layer is closer to the substrate than the second layer. [Effects of the Invention]

[0011] The low refractive index film is advantageous from the viewpoint of exhibiting a high antireflection performance. Simple diagram description

[0012] Fig. 1 is a cross-sectional view showing an example of a laminate of the present invention. [Fig. 2A] is a cross-sectional view showing another example of the layered product of the present invention. [Fig. 2B] is a cross-sectional view showing still another example of the layered product of the present invention. [Fig. 2C] is a cross-sectional view showing still another example of the layered product of the present invention. [Fig. 2D] is a cross-sectional view showing still another example of the layered product of the present invention. [FIG. 3] is a scanning transmission electron microscope (STEM) photograph showing a cross section of the laminate of Example 1. [Fig. 4] is a STEM photograph of a cross section of the layered product of Example 1, in which voids are colored black. Implementation

[0013] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. The following description is for illustration of the present invention, and the present invention is not limited to the following embodiments. In this specification, "anti-reflection" means having the function of preventing light from being reflected from the surface, or having the function of reducing reflection compared to the case where there is no structure for anti-reflection even if there is reflection. "Film" can be understood as a film, a coating, and a layer.

[0014] As shown in FIG. 1 , the low refractive index film 10 is a film formed along the surface of the substrate 20. The low refractive index film 10 includes a first layer 11 and a second layer 12. The first layer 11 is located near the substrate 20 in the thickness direction of the low refractive index film 10. The second layer 12 is adjacent to the first layer 11 in the thickness direction of the low refractive index film 10 and is located far from the substrate 20. The low refractive index film 10 has a refractive index of 1.01 or more and 1.30 or less. In this specification, "refractive index" refers to an absolute refractive index, such as a value measured at 25° C. using a D line of sodium. The refractive index of the low refractive index film 10 can be determined, for example, by measurement based on reflectivity spectroscopy.

[0015] "Substrate" refers to an article or part of an article coated with a low refractive index film or an anti-reflective film. "Substrate" is not limited to these, and may be, for example, optical elements such as lenses, reflectors, prisms, diffusers, flat microlens arrays, polarizing elements, diffraction gratings, holograms, light modulation elements, light deflection elements, and filters (including acousto-optical elements), solid-state imaging devices, windows or windshields of buildings or cars, light-transmitting shields such as helmets and goggles, or display devices such as displays and screens. The coated surface of the "substrate" may be a flat surface, a curved surface, or a concave-convex surface.

[0016] As shown in FIG. 1 , each of the first layer 11 and the second layer 12 contains hollow particles 13 and a binder 14. The first layer 11 has a thickness of less than half the thickness of the low refractive index film 10 and less than 200 nm. The first layer 11 has a void 15 in a manner that satisfies at least one of the following conditions (I) and (II). Furthermore, the void 15 is a space that exists inside or at the interface of the low refractive index film 10 and is not occupied by the hollow particles 13 and the binder 14. For example, the internal space of the hollow particle 13 does not belong to the void 15. For example, air exists in the void 15. (I) The number density ρv1 of the voids 15 having a cross-sectional area of ​​1000 nm 2 or more in the cross section S1 of the first layer 11 is greater than or equal to 5 / μm 2 and less than or equal to 100 / μm 2. (II) The ratio (Av1 / At1) of the cross-sectional area (Av1) of the void 15 existing in the cross-sectional area S1 to the area (At1) of the cross-sectional area S1 of the first layer 11 is 5% to 70%.

[0017] By satisfying at least one of the conditions (I) and (II) in the first layer 11, the quantitative state of the voids 15 in the first layer 11 becomes a desired state, and the first layer 11 in the low refractive index film 10 tends to have a lower refractive index. As a result, the low refractive index film 10 tends to exhibit a higher anti-reflection performance. The voids 15 can be formed inside the first layer 11 or at the interface between the low refractive index film 10 and other components.

[0018] Regarding the condition (I), "voids 15 having a cross-sectional area of ​​1000 nm 2 or more" means that the cross-sectional area of ​​one void 15 defined by the boundary between the void 15 and the material surrounding the void 15 in the cross section S1 is 1000 nm 2 or more. When the number density ρv1 is obtained, the region surrounded by a rectangle having a length (width) of 1000 nm (1 μm) along the surface of the substrate 20 and a height corresponding to the thickness d1 of the first layer 11 in the cross section of the laminate including the first layer 11 is set as the cross section S1, and the number of voids 15 having a cross-sectional area of ​​1000 nm 2 or more existing therein is counted. The number density ρv1 is obtained by dividing this number by the area At1 of the cross section S1. Furthermore, when the number density ρv1 is obtained, the voids completely included in the region of the cross section S1, the voids in which a part of the surface of the substrate or the base layer becomes a part of the boundary, and the voids only partially included in the cross section S1 are also counted. By making the number density ρv1 5 / μm 2 or more, the first layer 11 in the low refractive index film 10 is easy to have a lower refractive index. In addition, even if the difference between the expansion coefficient of the substrate 20 and the expansion coefficient of the low refractive index film 10 is large, it is easy to reduce the risk of cracks or ruptures in the low refractive index film 10 caused by temperature changes. The number density ρv1 is preferably 6 / μm 2 or more, more preferably 8 / μm 2 or more, and further preferably 10 / μm 2 or more. By making the number density ρv1 100 / μm 2 or less, the low refractive index film 10 is easy to have the required mechanical strength. In addition, it is easy to prevent the scattering of incident light such as visible light from becoming larger, and it is easy to keep the haze of the article having the low refractive index film 10 low. The number density ρv1 is preferably 99 / μm 2 or less, more preferably 90 / μm 2 or less, and further preferably 85 / μm 2 or less. The number density ρv1 can be 75 / μm 2 or less, and can also be 50 / μm 2 or less.

[0019] Regarding the condition (II), the ratio (Av1 / At1) expressed as a percentage is also referred to as the void ratio Vv1 [%]. When the void ratio Vv1 is calculated, the sum of the areas of the voids 15 having a cross-sectional area of ​​1000 nm 2 or more existing in the cross section S1 is set as Av1. Furthermore, when the sum of the areas Av1 of the voids 15 is calculated, the area of ​​the voids completely included in the region of the cross section S1 is considered, and for the voids only partially included in the region of the cross section S1, the area of ​​the portion existing in the region of the cross section S1 is considered to calculate Av1. By making the void ratio Vv1 5% or more, the first layer 11 in the low refractive index film 10 is easy to have a lower refractive index. In addition, even if the difference between the expansion coefficient of the substrate 20 and the expansion coefficient of the low refractive index film 10 is large, it is easy to reduce the risk of cracks or ruptures in the low refractive index film 10 caused by temperature changes. The void ratio Vv1 is preferably higher than 5%, more preferably 9% or more, and further preferably 10% or more. When the void ratio Vv1 is 70% or less, the low refractive index film 10 can easily have the required mechanical strength. The void ratio Vv1 is preferably lower than 70%, more preferably 65% ​​or less. The void ratio Vv1 can be 50% or less, and can also be 30% or less.

[0020] When the first layer 11 satisfies the condition (I) above, the number density ρv1 is, for example, greater than the number density ρv2 of the voids 15 having a cross-sectional area of ​​1000 nm2 or more in the cross-sectional surface S2 of the second layer 12 extending along the surface of the substrate 20. Thus, the first layer 11 in the low refractive index film 10 is more likely to have a lower refractive index. When the number density ρv2 is obtained, the number of voids 15 having a cross-sectional area of ​​1000 nm2 or more existing inside the cross-sectional surface S2 surrounded by a rectangle having a length (width) of 1000 nm (1 μm) along the surface of the substrate 20 and a height corresponding to the thickness d2 (=dt-d1) of the second layer 12 in the cross-sectional surface of the laminate including the second layer 12 is counted. The number density ρv2 is obtained by dividing this number by the area At2 of the cross-sectional surface S2. Furthermore, when the number density ρv2 is calculated, in addition to the voids completely included in the region of the cross section S2, the voids that are part of the boundary with a portion of the surface opposite to the surface in contact with the first layer 11 in the second layer 12 and the voids that are only partially included in the region of the cross section S2 are also counted. The sum of the areas of the voids 15 that exist in the cross section S2 and have a cross-sectional area of ​​1000 nm2 or more is set as Av2. When the sum of the areas of the voids 15 Av2 is calculated, the area of ​​the voids that are completely included in the region of the cross section S2 is considered, and for the voids that are only partially included in the region of the cross section S2, the area of ​​the portion that exists in the region of the cross section S2 is considered to calculate Av2.

[0021] When the first layer 11 satisfies the condition of (II) above, the ratio (Av1 / At1) is, for example, higher than the ratio (Av2 / At2). The ratio (Av2 / At2) is the ratio of the cross-sectional area Av2 of the void 15 present in the cross-section S2 of the second layer 12 to the total cross-sectional area At2 of the cross-section S2 of the second layer 12 having a length of 1000 nm extending along the surface of the substrate 20, expressed as a percentage. Thereby, it is easier for the first layer 11 in the low refractive index film 10 to have a lower refractive index more surely.

[0022] Typically, the cross-sections S1 and S2 are cross-sections formed by cutting the low refractive index film 10 along a plane parallel to the normal of the surface of the substrate 20. The cross-sections shown in the cross-sectional views or electron micrographs in the accompanying drawings belong to this type of cross-section.

[0023] The first layer 11 and the second layer 12 are distinguished by an interface surface orthogonal to the normal of the surface of the substrate 20. Typically, in the thickness direction of the low refractive index film 10, the portion closer to the substrate 20 than the interface surface belongs to the first layer 11, and the portion farther from the substrate 20 than the interface surface belongs to the second layer 12. Furthermore, this interface surface may be actual or imaginary. For example, the adhesive 14 may be in a continuous phase in the first layer 11 and the second layer 12.

[0024] The low refractive index film 10 has a thickness dt of, for example, 70 nm or more. The thickness d1 of the first layer 11 is equal to dt / 2, for example, when 70 nm ≤ dt ≤ 400 nm. Also, the thickness d1 of the first layer 11 is equal to 200 nm, for example, when 400 nm < dt. By having the first layer 11 with such a thickness satisfy at least one of the conditions of (I) and (II), it is easier for the low refractive index film 10 to exhibit higher antireflection performance more surely.

[0025] The refractive index of the low refractive index film 10 is preferably 1.05 or more and 1.28 or less, more preferably 1.10 or more and 1.25 or less.

[0026] The material of the adhesive 14 is not limited to a specific material. The material of the adhesive 14 is, for example, a material that satisfies the required characteristics from the viewpoints of environmental resistance, wear resistance, and adhesion to the substrate. Also, the material of the adhesive 14 is preferably a material having higher transparency with respect to light in the specified wavelength range used in the article provided with the low refractive index film 10. The specified wavelength range used in the article provided with the low refractive index film 10 may exist in the visible light region or the near-infrared region.

[0027] The adhesive 14 includes, for example, silica, silsesquioxane, or a mixture of silica and silsesquioxane. In this case, the wavelength range in which transparency can be ensured in the visible light region of the adhesive 14 is easily widened. In addition, the refractive index of the adhesive 14 can also be reduced to a certain extent.

[0028] The adhesive 14 may also contain a predetermined curable resin, for example, depending on the type of the substrate 20 or the performance required of the article having the low refractive index film 10. The curable resin is in liquid form when applied to the surface of the substrate 20, but is cured by heating and light irradiation after application, so that the production of the low refractive index film 10 becomes easy. Examples of the curable resin are phenol resin, epoxy resin, melamine resin, unsaturated polyester resin, polyurethane resin, polyimide resin, acrylic resin, and polysilicone resin.

[0029] When the adhesive 14 includes silicon dioxide, silsesquioxane, or a mixture of silicon dioxide and silsesquioxane, for example, at least one of 1%≦W Si≦60% and 5%≦W Sq≦90% is satisfied. W Si is the ratio of the mass of silicon dioxide contained in the adhesive 14 to the mass of the solid components of the low refractive index film 10. W Sq is the ratio of the mass of silsesquioxane contained in the adhesive 14 to the mass of the solid components of the low refractive index film 10. More preferably, at least one of 5%≦W Si≦60% and 8%≦W Sq≦80% is satisfied, and more preferably, at least one of 8%≦W Si≦30% and 10%≦W Sq≦60% is satisfied.

[0030] When the binder 14 includes silica, silsesquioxane, or a mixture of silica and silsesquioxane, for example, the condition of 5%≦Wb≦90% is satisfied. Wb is the ratio of the sum of the mass of silica and the mass of silsesquioxane contained in the binder 14 to the mass of the solid content of the low refractive index film 10. It is more desirable to satisfy the condition of 10%≦Wb≦85%, and more desirable to satisfy the condition of 20%≦Wb≦80%. The silica of the binder 14 is obtained, for example, by hydrolysis and polycondensation of a tetrafunctional alkoxysilane. The silsesquioxane in the binder 14 is obtained, for example, by hydrolysis and polycondensation of a trifunctional alkoxysilane.

[0031] The hollow particles 13 are typically particles having pores divided by shells. When the low-refractive-index film 10 contains the hollow particles 13, the refractive index of the low-refractive-index film 10 is easily lowered.

[0032] The average particle diameter de of the hollow particles 13 is not limited to a specific value. The average particle diameter de of the hollow particles 13 is, for example, 20 nm or more and 100 nm or less. Since the average particle diameter de is 20 nm or more, the pores inside the hollow particles 13 easily have a desired volume. Thereby, the refractive index of the low refractive index film 10 easily becomes low. Since the average particle diameter de is 100 nm or less, the light scattering does not easily become large. The average particle diameter de of the hollow particles 13 is, for example, the average particle diameter in the particle size distribution based on the number.

[0033] The average particle diameter de of the hollow particles 13 is preferably 25 nm or more and 90 nm or less, and more preferably 30 nm or more and 80 nm or less.

[0034] The material of the shell of the hollow particles 13 is not limited to a specific material. Examples of the material of the shell of the hollow particles 13 are inorganic compounds such as SiO2, ZrO2, and MgF2, fluorine-based compounds such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and polymers forming resins. The material of the shell of the hollow particles 13 preferably has a lower refractive index, for example, a refractive index equal to or lower than the refractive index of SiO2.

[0035] The thickness of the shell of the hollow particles 13 is not limited to a specific value. The thickness of the shell of the hollow particles 13 is, for example, 5 nm or more and 20 nm or less, and preferably 10 nm or more and 20 nm or less.

[0036] The ratio Whp [%] of the mass of the hollow particles 13 to the mass of the solid component of the low refractive index film 10 is not limited to a specific value. The ratio Whp is, for example, 5% or more and 90% or less, preferably 10% or more and 85% or less, and more preferably 20% or more and 80% or less.

[0037] The relationship between the content of the hollow particles 13 and the content of the binder 14 in the low refractive index film 10 is not limited to a specific relationship. The low refractive index film 10 satisfies, for example, the condition of 0.2 < Wb / Whp < 20. Since the condition of Wb / Whp < 20 is satisfied, the refractive index of the low refractive index film 10 easily becomes low. In addition, even if the difference between the expansion coefficient of the substrate 20 and the expansion coefficient of the low refractive index film 10 is large, cracks or breakage of the low refractive index film 10 are not easily caused by temperature changes. Since the condition of 0.2 < Wb / Whp is satisfied, the low refractive index film 10 easily has a desired mechanical strength, and thus it can be expected that breakage or peeling of the low refractive index film 10 does not easily occur.

[0038] The low refractive index film 10 preferably satisfies the condition of 0.3 < Wb / Whp < 15, more preferably satisfies the condition of 0.4 < Wb / Whp < 12, and even more preferably satisfies the condition of 0.5 < Wb / Whp < 10.

[0039] The low refractive index film 10 may also contain functional components such as a light absorber as needed. Thereby, the low refractive index film 10 can exhibit an additional function corresponding to the functional component. Examples of the light absorber are an ultraviolet absorber and an infrared absorber. The ultraviolet absorber is not limited to a specific ultraviolet absorber. Examples of the ultraviolet absorber are benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and tri -based ultraviolet absorbers. Examples of the infrared absorber are not limited to a specific infrared absorber. Examples of the infrared absorber are squarylium-based infrared absorbers, diimmonium-based infrared absorbers, cyanine-based infrared absorbers, phthalocyanine-based infrared absorbers, azo-based infrared absorbers, and phosphoric acid-metal compounds containing phosphoric acid derivatives such as phosphonic acid and phosphate esters and metal components such as copper.

[0040] As shown in FIG. 1, for example, a laminate 1a including the low refractive index film 10 can be provided. The laminate 1a includes a substrate 20 and the low refractive index film 10. In the laminate 1a, the low refractive index film 10 is formed along the surface of the substrate 20.

[0041] The low refractive index film 10 is in contact with the surface of the substrate 20, for example.

[0042] As shown in FIG. 1, in the laminate 1a, the low refractive index film 10 is formed in contact with one main surface of the substrate 20, for example. The low refractive index film 10 can also be formed in contact with both main surfaces of the substrate 20, for example.

[0043] The substrate 20 can be a plate-like member having a flat surface, a lens or the like member having a curved surface, a diffraction grating or the like member including a surface having irregularities, or a microlens array and a diffuser or the like member including a surface having fine irregularities. The substrate 20 can also be a member having a surface defined by a combination of their surfaces.

[0044] The substrate 20 is an article or a part of an article coated with a low refractive index film or an anti-reflection film, but is not limited to an article with a specific function. The substrate 20 may be, for example, a lens, a reflector, a prism, a diffuser, a flat microlens array, a polarizing element, a diffraction grating, a hologram, a light modulating element, a light deflecting element, and an optical filter and other optical elements (including acousto-optical elements), a solid-state imaging device, a window or windshield of a building or a car, a helmet, and a light-transmitting shield such as a goggles, a display device such as a display and a screen. When the low refractive index film 10 is used for anti-reflection, the light transmittance in the laminate 1a tends to be high.

[0045] As shown in FIG. 1 , the substrate 20 includes, for example, a plate-shaped substrate 21 having two main surfaces facing opposite sides. The material of the substrate 21 is not limited to a specific material. The material of the substrate 21 is, for example, glass, resin, or semiconductor materials such as silicon. Examples of glass are soda glass, borosilicate glass, aluminoborosilicate glass, fluorophosphate glass, phosphate glass, and multi-component optical glass with improved optical properties such as refractive index. Examples of resins are polyolefin resins, polycarbonate resins, polyamide resins, epoxy resins, acrylic resins, polyether resins, polyimide resins, polyurethane resins, and polysilicon resins.

[0046] The arithmetic mean roughness Ra of the surface of the substrate 20 determined according to Japanese Industrial Standard (JIS) B 0601-1994 is not limited to a specific value. The arithmetic mean roughness Ra of the surface of the substrate 20 is, for example, 0.3 nm or more and 140 nm or less. By having the arithmetic mean roughness Ra of the surface of the substrate 20 being 0.3 nm or more, the adhesion between the substrate 20 and the low refractive index film 10 is easily improved. Therefore, even if the first layer 11 has the gap 15, the low refractive index film 10 is not easily peeled off from the substrate 20. By having the arithmetic mean roughness Ra of the surface of the substrate 20 being 140 nm or less, the film thickness of the low refractive index film 10 is not easily spatially uneven, and the function that the low refractive index film 10 should play is not easily in-plane uneven. In addition, the penetration performance of effective light can be prevented from being reduced by the phenomenon of light scattering in the laminate 1a.

[0047] The arithmetic mean roughness Ra of the surface of the substrate 20 is preferably not less than 0.4 nm and not more than 100 nm, more preferably not less than 0.5 nm and not more than 50 nm, and further preferably not less than 0.5 nm and not more than 35 nm.

[0048] The arithmetic mean roughness Ra of the surface of the substrate 20 and the wavelength λ i [nm] of the incident light to the laminate 1a satisfy the relationship of Ra ≦ λ i / 4, for example. Thus, light scattering is less likely to occur in the laminate 1a. For example, when the incident light is visible light having a wavelength of 550 nm, by satisfying the relationship of Ra ≦ 550 / 4 [nm] = 137.5 nm, a decrease in transmittance due to light scattering can be prevented.

[0049] The arithmetic mean roughness Ra of the surface of the substrate 20 and the average particle size de of the hollow particles 13 satisfy the relationship of Ra≦de, for example. Thus, the hollow particles 13 are easily dispersed uniformly in the low refractive index film 10. For example, when the average particle size de of the hollow particles 13 is 50 nm, it is more desirable to satisfy the relationship of Ra≦50 nm.

[0050] The contact angle α of the water drop on the surface of the substrate 20 is not limited to a specific value. On the other hand, by adjusting the wettability of the surface of the substrate 20, the voids 15 are easily formed near the interface between the low refractive index film 10 and the substrate 20 in the low refractive index film 10.

[0051] The contact angle α of the water drop on the surface of the substrate 20 is, for example, not less than 5° and not more than 140°. When the contact angle α is not less than 5°, the liquid composition as the precursor of the low refractive index film 10 bounces on the surface of the substrate 20, and the gap 15 can be formed in the first layer 11 in a desired state. When the contact angle α is not more than 140°, the liquid composition as the precursor of the low refractive index film 10 can be prevented from excessively bouncing on the surface of the substrate 20, so that the low refractive index film 10 can easily have a desired film thickness. In addition, it is not easy to generate stripe-shaped defects and uneven film thickness in the low refractive index film 10, and it is easy to exhibit uniform characteristics within the surface of the low refractive index film 10.

[0052] The arithmetic mean roughness Ra of the surface of the substrate 20 and the contact angle α of a water drop on the surface of the substrate 20 can be adjusted, for example, by performing a predetermined surface treatment on the surface of the substrate 20. An example of a surface treatment method is a method of chemically or physically changing the surface state of the substrate 20 using a chemical treatment or a sandblasting treatment. For example, according to a method of forming fine concavoconvexities on the surface of the substrate 20, the liquid composition as a precursor of the low refractive index film 10 can easily exert a physical bonding effect such as an anchoring effect on the surface of the substrate 20. An example of a surface treatment method may also be a method of changing the chemical bonding state of the functional groups on the surface of the substrate 20, such as a corona treatment, a plasma treatment, an ultraviolet irradiation treatment, and a flame treatment. By such a method, the wettability of the liquid composition as a precursor of the low refractive index film 10 on the surface of the substrate 20 can also be adjusted. Furthermore, by applying a surface treatment agent such as a primer or a silane coupling agent, the wettability of the liquid composition as a precursor of the low refractive index film 10 on the surface of the substrate 20 can also be adjusted. In addition, the arithmetic mean roughness Ra of the surface of the substrate 20 and the contact angle α of a water drop on the surface of the substrate 20 can also be adjusted by forming the surface of the substrate 20 with predetermined layers such as a functional layer and a base layer.

[0053] The substrate 20 may also have a specified functional layer. In this case, the functional layer is, for example, a layer, film, or thin film that adjusts the transmittance and reflectivity of light, such as an anti-reflection film, a light absorbing film, and a light reflecting film. An anti-reflection film is, for example, a single-layer or multi-layer dielectric film containing inorganic materials such as SiO2, MgF2, and TiO2. An light reflecting film is, for example, a single-layer or multi-layer dielectric film containing inorganic materials such as SiO2, MgF2, and TiO2. The light reflecting film may also be a metal film. An light absorbing film is, for example, a film containing a resin containing an infrared absorber or an ultraviolet absorber. Examples of infrared absorbers are squarylium pigments, diimmonium pigments, cyanine pigments, phthalocyanine pigments, azo pigments, and complexes containing phosphorus oxides and metals such as copper. Examples of ultraviolet absorbers are diphenyl ketone pigments, benzotriazole pigments, and triphenyl ketone pigments. The functional layer may also be a layer, film, or thin film that regulates the behavior of water or oil contained in the environment, such as an anti-fog film, a water-repellent film, an oil-repellent film, and a hydrophilic film.

[0054] The low refractive index film 10 can be manufactured, for example, by applying a predetermined liquid composition on the surface of the substrate 20 to form a coating film, and curing the coating film. The liquid composition can be prepared, for example, by mixing the raw material of the binder 14 with the hollow particles 13. The above-mentioned functional components can be added to the liquid composition as needed.

[0055] The liquid composition may also contain solvent and water, for example. This makes it easy to achieve the purpose of adjusting the viscosity of the liquid composition, improving the dispersibility of the functional components in the liquid composition, or improving the solubility of the raw materials of the adhesive 14. The solvent is not limited to a specific solvent. Examples of the solvent may also be tetrahydrofuran (THF), cyclohexanone, cyclohexane, toluene, xylene, alcohols, phenols, water, glycerol, acetone, methyl ethyl ketone (MEK), diethyl ether, ethyl acetate, and mixtures thereof.

[0056] The liquid composition may also contain an acid, for example. When the raw material of the binder 14 contains alkoxysilane, the acid acts as a catalyst for the hydrolysis of the alkoxysilane. The acid is not limited to a specific acid. Examples of the acid are formic acid and hydrochloric acid.

[0057] The laminate 1a can be changed from various viewpoints. For example, the laminate 1a can also be formed as the laminate 1b shown in FIG. 2A, the laminate 1c shown in FIG. 2B, the laminate 1d shown in FIG. 2C, or the laminate 1e shown in FIG. 2D. The laminate 1b, the laminate 1c, the laminate 1d, and the laminate 1e are each constructed in the same manner as the laminate 1a except for the parts specifically described. The same symbols are given to the components of the laminate 1b, the laminate 1c, the laminate 1d, or the laminate 1e that are the same as or correspond to the components of the laminate 1a, and the detailed description is omitted. The description of the laminate 1a is also applicable to the laminate 1b, the laminate 1c, the laminate 1d, and the laminate 1e as long as there is no technical contradiction.

[0058] As shown in FIG. 2A and FIG. 2B , the substrate 20 of the laminate 1b and 1c further includes a base layer 22. The base layer 22 forms the surface of one or both main surfaces of the substrate 20. In the laminate 1b, the low refractive index film 10 is formed on the base layer 22. The base layer 22 makes it easy to adjust the surface of the substrate 20 to a state suitable for forming the low refractive index film 10. For example, it is easy to adjust the arithmetic mean roughness Ra of the surface of the substrate 20 or the contact angle α of a water drop on the surface of the substrate 20 to a desired range.

[0059] In the laminate 1c, a pair of low-refractive-index films 10 are formed on the surfaces of both main surfaces of the substrate 20. One of the pair of low-refractive-index films 10 is formed on the base layer 22.

[0060] The base layer 22 is not limited to a specific layer. The base layer 22 includes, for example, at least one of silicon dioxide and silsesquioxane. The base layer 22 may include silicon dioxide, may include silsesquioxane, or may include a mixture thereof. The base layer 22 may also include inorganic materials such as SiO2, TiO2, and MgF2. The base layer 22 may also be a multilayer film formed by laminating multiple layers of these inorganic materials. The base layer 22 may also be a layer including resins such as polyolefin resins, polycarbonate resins, polyamide resins, epoxy resins, acrylic resins, polyether resins, polyimide resins, polyurethane resins, fluorine resins, and polysilicone resins.

[0061] As shown in FIG. 2A and FIG. 2B , the surface of one main surface of the substrate 20 is formed by the base layer 22. On the other hand, the surfaces of both main surfaces of the substrate 20 may also be formed by the base layer 22. In this case, a pair of low refractive index films 10 may also be formed on the base layer 22 forming the surfaces of both main surfaces of the substrate 20.

[0062] The thickness of the base layer 22 is not limited to a specific thickness. The base layer 22 has a thickness of 5-50 nm, for example.

[0063] As shown in FIG. 2C and FIG. 2D , the substrate 20 of the laminated bodies 1d and 1e further includes a functional layer 23. The functional layer 23 forms the surface of one main surface of the substrate 20. In the laminated body 1d, the low refractive index film 10 is formed on the functional layer 23. The functional layer 23 can be used to impart the desired function to the laminated bodies 1d and 1e. In addition, the functional layer 23 can also be used to adjust the surface of the substrate 20 to a state suitable for forming the low refractive index film 10. For example, the functional layer 23 can easily adjust the arithmetic mean roughness Ra of the surface of the substrate 20 or the contact angle α of a water drop on the surface of the substrate 20 to a desired range.

[0064] In the laminate 1e, a pair of low-refractive-index films 10 are formed on the surfaces of both main surfaces of the substrate 20. One of the pair of low-refractive-index films 10 is formed on the functional layer 23.

[0065] The functional layer 23 is not limited to a specific layer as long as it has a specified function. The functional layer 23 is, for example, a layer, film, or thin film that adjusts the transmittance and reflectivity of light, such as an anti-reflection film, a light absorbing film, and a light reflecting film. The anti-reflection film is, for example, a film composed of a single layer or multiple layers of inorganic materials such as SiO2, MgF2, and TiO2. The light reflecting film may also include a film composed of a single layer or multiple layers of inorganic materials such as SiO2, MgF2, and TiO2, or a metal film composed of metal. The light absorbing film is, for example, a film containing a resin containing an infrared absorber or an ultraviolet absorber. Examples of infrared absorbers are squarylium pigments, diimmonium pigments, cyanine pigments, phthalocyanine pigments, azo pigments, and complexes containing phosphorus oxides and metals such as copper. Examples of ultraviolet absorbers are diphenyl ketone pigments, benzotriazole pigments, and triphenyl ketone pigments. The light absorbing film may also include a metal film composed of a metal.

[0066] The functional layer 23 may also be a layer, film, or thin film that adjusts the behavior of moisture or oil contained in the environment, such as an anti-fog film, a water-repellent film, an oil-repellent film, and a hydrophilic film. In other words, the laminates 1d and 1e may also include a substrate 20, at least one of an anti-fog film, a water-repellent film, an oil-repellent film, and a hydrophilic film formed on the substrate 20, and a low refractive index film 10.

[0067] As shown in FIG. 2C and FIG. 2D , the surface of one main surface of the substrate 20 is formed by the functional layer 23. On the other hand, the surfaces of both main surfaces of the substrate 20 may also be formed by the functional layer 23. In this case, the low refractive index film 10 may also be formed on the functional layer 23 forming the surfaces of both main surfaces of the substrate 20.

[0068] Various articles having the low refractive index film 10 can be provided. For example, an optical element having a surface formed by the low refractive index film 10 can be provided. In addition, a windshield material having the low refractive index film 10 can be provided. Examples of windshield materials are window glass and windshield. Furthermore, a display device having the low refractive index film 10 can also be provided. Example

[0069] The present invention is described in more detail by way of examples. The present invention is not limited to the following examples. First, the evaluation method for each example and each comparative example is described.

[0070] <Evaluation of film forming properties> The film-forming property of the low-refractive index film liquid composition of each example and each comparative example on the surface of the substrate of each example and each comparative example was evaluated. When it was confirmed that there was an uncoated portion when the low-refractive index film liquid composition was applied to the surface of the substrate, or that the thickness of the low-refractive index film was uneven, the film-forming property was evaluated as "F". On the other hand, when such a situation was not confirmed, the film-forming property was evaluated as "A". The results are shown in Table 2.

[0071] <Reflectivity, Refractive Index, and Film Thickness> Using a spectrophotometer (manufactured by Hitachi High-Technologies Corporation, product name: U-4000), the incident angle was adjusted to 12°, and the spectral reflectance of the laminated body of each embodiment and each comparative example was measured. Furthermore, the refractive index and film thickness of the low refractive index film of each embodiment and each comparative example were obtained using the optical thin film design software FilmWizard (manufactured by Scientific Computing International). The spectral reflectance, refractive index, and film thickness at the D line (wavelength 589 nm) are shown in Table 2. In addition, as a laminated body related to the measurement of spectral reflectance, the following laminated body can be used, that is, when a low refractive index film is formed on one main surface of the substrate, the main surface where the low refractive index film is not formed is made into a rough surface with a black coating on the entire surface, or is made into a matte surface, etc., so that the influence of the reflection of the main surface can be ignored. In this case, the black coating is not limited to a specific coating, and can be an ink coating, or a coating used in the optical field called an anti-glare material (flare cut). As black paint, for example, GT-1000, GT-2000, GT-7, and CS-37 manufactured by CANON Chemical Co., Ltd. can be used. The matte surface is formed by using a grinding material having a particle size of #500 (No. 500) or more. The main surface that has been processed into a matte surface can also be painted black afterwards. In the case where the laminate includes a base layer, the film thickness of the base layer is measured by reflection spectroscopy using a film thickness measurement system F20-UV manufactured by FILMETRICS before forming a low refractive index film.

[0072] <Haze> The haze was measured at three points of the laminate of each Example and each Comparative Example, separated by 1 cm, using a haze meter (manufactured by SUGA Test Instruments, product name: HZ-V3), and the average value was calculated and used as the haze of each Example and Comparative Example. The results are shown in Table 2.

[0073] <Number of voids Nv and void ratio Vv1> In order to confirm the state of voids in the low refractive index film of the laminate of each example and each comparative example, first, a thickness of 100 nm was cut along a cross-section parallel to the normal of the substrate surface using a focused ion beam device SMI3200F manufactured by Seiko Electron Nano-Technology Co., Ltd. Carbon with a thickness of 400 to 500 nm was vapor-deposited on the outermost surface to produce a specimen. For the cross-section of this specimen, a bright-field transmission observation was performed at a magnification of 250,000 times using a scanning transmission electron microscope (STEM) S-5500 manufactured by Hitachi High-Technologies Corporation, and a transmission captured image of the laminate including the low refractive index film was obtained. The acceleration voltage was 200 kV. In the transmission captured image of the laminate, white enhancement was performed to observe voids. After digitizing the obtained transmission captured image of the cross-section of the laminate with a tone value of 0 to 255, histogram equalization processing was performed to obtain an image with a fixed contrast. Thereafter, tones of 229 to 255 were regarded as voids. The number, number density, and cross-sectional area of the voids were calculated as follows. First, for the transmission captured image of the cross-section of the laminate, an image of 1000 nm (1 μm) was obtained along the direction parallel to the surface of the substrate, and the voids were specified based on the above method. Fig. 4 shows the transmission captured image of the cross-section of the laminate and the specified voids. In Fig. 4, the voids are shown in black for distinction from other parts. Subsequently, the thickness dt of the low refractive index film was measured and the thickness d1 of the first layer was obtained, and the area At1 of the cross-section S1 of the first layer was obtained by the operation of d1 × 1000. Regarding the thickness d1 of the first layer, when 70 nm ≤ dt ≤ 400 nm, d1 = dt / 2, and when 400 nm < dt, d1 = 200 nm. The number Nv1 of voids in the cross-section S1 of the first layer having a cross-sectional area of 1000 nm2 or more was counted, and the sum Av1 of the cross-sectional areas of the voids having a cross-sectional area of 1000 nm2 or more was calculated. In the same manner, the area At2 of the cross-section S2 of the second layer (=(dt - d1) × 1000) was calculated, the number Nv2 of voids in the cross-section S2 of the second layer having a cross-sectional area of 1000 nm2 or more was counted, and the sum Av2 of the cross-sectional areas of the voids having a cross-sectional area of 1000 nm2 or more was calculated. The number density ρv1 was obtained by dividing the number Nv1 of voids by the area At1. In addition, the porosity Vv1 was determined by dividing the sum Av1 of the cross-sectional areas of the voids by the area At1. In each example, etc., transmission captured images of the laminate were obtained at three points separated by 10 mm in the plane, the above parameters were respectively obtained, and the average values thereof were adopted. The values of the number Nv of voids and the area ratio Vv [%] of voids were adopted by rounding off the values below the decimal point. Regarding the above operations, etc., when necessary, they were performed using the image processing software ImageJ version 1.51 provided by the National Institutes of Health, USA.

[0074] <Abrasion resistance test> While applying a load of 50 g / cm2 to the laminate of each embodiment and each comparative example, a cotton cloth Clint manufactured by Asahi Kasei Chemicals Corporation was passed back and forth 5 times on the surface of the laminate. Thereafter, the reflectivity at the D line (wavelength = 589 nm) was measured, and the difference in reflectivity before and after the abrasion resistance test was compared. Regarding the difference in reflectivity ΔRD, the case where ΔRD / (reflectivity RD at the D line before the abrasion resistance test) ≤ 25% was evaluated as "A", and the case where ΔRD / (reflectivity RD at the D line before the abrasion resistance test) > 25% was evaluated as "F".

[0075] <Example 1> 0.6 g of tetraethoxysilane (TEOS) (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.18 g of methyltriethoxysilane (MTES) (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.82 g of 0.3 mass % formic acid (manufactured by Kishida Chemical Co., Ltd.), 3 g of sol containing hollow silica particles (manufactured by JGC Catalysts & Chemicals Co., Ltd., product name: Thrulya 4110), and 22.4 g of ethanol (manufactured by Kishida Chemical Co., Ltd.) were mixed and reacted at 35°C for 3 hours. The sol containing hollow silica particles used contained a solvent and contained 25 mass % of hollow silica as a solid content. The average particle size of the hollow silica particles in the particle size distribution based on the number was about 50 nm. The thickness of the shell formed by silica of the hollow silica particles was 10 to 20 nm. The maximum size of the internal space of the hollow silica particles is about 10 to 30 nm. The refractive index of the hollow particles is 1.25. In this way, the liquid composition for low refractive index film of Example 1 is obtained. In the liquid composition for low refractive index film of Example 1, the content of solid components derived from TEOS is 0.6% by mass in terms of silica, the content of methylsilsesquioxane (MeSq) derived from MTES is 1.6% by mass, and the content of hollow silica particles is 2.6% by mass. In the solid components of the liquid composition for low refractive index film of Example 1, on a mass basis, 13% of silica derived from TEOS, 33% of MeSq derived from MTES, and 54% of hollow silica particles are included. Furthermore, the content of hollow silica particles is determined on the assumption that the solid content of the sol containing hollow silica particles is 25% by mass and the solid content is hollow silica particles. In addition, the mass ratio of MTES added to the preparation of the liquid composition for low refractive index film in Example 1 relative to the mass ratio of TEOS is 7 / 3.

[0076] A glass substrate made of soda-lime glass (size: 40 mm × 40 mm, thickness: 1 mm, double-sided polished, refractive index: 1.52) was cleaned in ultrapure water for 15 minutes using an ultrasonic cleaner (manufactured by Emerson, Japan, model: Bransonic 5510-J-DTH, output: 135 W). Thereafter, the glass substrate was cleaned in a commercially available alkaline cleaning solution (2% dilution of Semi Clean LGL, manufactured by Yokohama Oil & Fats Industry Co., Ltd.) for 15 minutes, and then cleaned in ultrapure water for 15 minutes. Thereafter, a corona surface treatment device (manufactured by Shinko Electric Instrument Co., Ltd., model: Corona Master PS-1M) was used to perform corona treatment on the surface of the glass substrate at an output of 14 kV. The contact angle of a water droplet on the surface of the glass substrate after corona treatment was 2°. The glass substrate was stored in a clean bench with a cleanliness level of less than 100 maintained at a temperature of 23-25°C and a relative humidity of 50-60% for 12 hours. In this way, the substrate of Example 1 was prepared. As shown in Table 1, the contact angle of a water drop on the surface of the substrate of Example 1 was 32°, and the arithmetic mean roughness Ra of the surface of the substrate of Example 1 was 0.5 nm. The contact angle of the water drop was measured using a contact angle meter manufactured by ASUMI GIKEN. The arithmetic mean roughness Ra was determined based on the measurement results of an electron force microscope SPI3700 manufactured by Seiko Instruments in a cyclic contact mode in accordance with JIS B 0601-1994. This is also the same in other examples and comparative examples.

[0077] The liquid composition for the low refractive index film of Example 1 was applied to one main surface of the substrate of Example 1 by spin coating to form a coating. The coating had a good and uniform appearance. Thereafter, the substrate with the coating was placed in an oven maintained at 200°C for 10 minutes to dry the coating, thereby obtaining the low refractive index film of Example 1. Thus, a laminate of Example 1 having a substrate and a low refractive index film formed on the substrate was obtained. When the appearance of the low refractive index film of Example 1 was observed, it was found to have a uniform thickness. The surface of the substrate of the laminate of Example 1 on which the low refractive index film was not formed was ground to a matte surface, and the spectral reflectance was measured. The reflectance of the laminate of Example 1 at D line (wavelength 589 nm) was 0.53%, the film thickness of the low refractive index film of Example 1 was 121 nm, and the refractive index was 1.16. In the low refractive index film of Example 1, the masses of silica and silsesquioxane forming the binder and the hollow silica particles were assumed to be equal to the masses of the corresponding components contained in the solid components of the liquid composition of Example 1. The results are shown in Table 2.

[0078] <Example 2> The low refractive index film liquid composition of Example 2 was prepared in the same manner as Example 1 except for the following aspects. Assuming that the mass ratio of each component relative to the mass of the entire solid component of the low refractive index film liquid composition is equal to the mass ratio of each component relative to the mass of the low refractive index film, the addition amounts of TEOS, MTES, and the sol containing hollow silica particles were adjusted so that the mass ratio of each component relative to the mass of the low refractive index film became the values ​​shown in Table 2.

[0079] 0.6 g of tetraethoxysilane (TEOS) (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.18 g of methyltriethoxysilane (MTES) (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.82 g of 0.3 mass % formic acid (manufactured by Kishida Chemical Co., Ltd.), and 22.4 g of ethanol (manufactured by Kishida Chemical Co., Ltd.) were mixed and reacted at 35° C. for 3 hours. Thereafter, ethanol was added to the mixed solution, and the total solid content of silicon dioxide from TEOS and methylsilsesquioxane (MeSq) from MTES was adjusted to 3 mass %, thereby obtaining a liquid composition B for an underlayer.

[0080] On one main surface of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned in advance by alkali cleaning, the base layer liquid composition B was applied by spin coating to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer B2. The substrate of Example 2 was obtained. The thickness of the base layer B2 was 13 nm. The contact angle of a water drop on the surface of the base layer B2 was 45°, and the arithmetic mean roughness Ra of the surface of the base layer B2 was 17 nm.

[0081] The liquid composition for the low refractive index film of Example 2 was applied to the surface of the base layer B2 of the substrate of Example 2 by spin coating to form a coating film. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 2 was placed in an oven maintained at 200°C for 10 minutes to dry the coating film, thereby forming the low refractive index film of Example 2. Thus, a laminate of Example 2 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 2, the low refractive index film of Example 2 had a uniform thickness. The surface of the substrate of the laminate of Example 2 on which the low refractive index film was not formed was ground to a matte surface, and the spectral reflectance was measured. In addition, the film thickness of the base layer B2 was about 10 nm, and the refractive index was almost the same as that of the glass as the substrate, so it is believed that the base layer B2 has almost no effect on the reflectance of the laminate. According to the obtained spectral reflectance, the reflectance of the laminate at the D line is less than 0.1%, the thickness of the low refractive index film of Example 2 is 121 nm, and the calculated refractive index is 1.23. On a mass basis, the low refractive index film of Example 2 includes 23% of silica forming a binder, 57% of silsesquioxane, and 20% of hollow silica particles.

[0082] <Example 3> The low refractive index film liquid composition of Example 3 was prepared in the same manner as Example 1 except for the following aspects. Assuming that the mass ratio of each component relative to the mass of the entire solid component of the low refractive index film liquid composition is equal to the mass ratio of each component relative to the mass of the low refractive index film, the added amounts of TEOS, MTES, and the sol containing hollow silica particles were adjusted so that the mass ratio of each component relative to the mass of the low refractive index film became the values ​​shown in Table 2.

[0083] The same base layer liquid composition B as in Example 2 was applied by spin coating on both main surfaces of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned in advance by alkali cleaning to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer B3, thereby obtaining a substrate of Example 3. The thickness of the base layer B3 was 13 nm. The contact angle of a water droplet on the surface of the base layer B3 was 43°, and the arithmetic mean roughness Ra of the surface of the base layer B3 was 11 nm.

[0084] The liquid composition for the low refractive index film of Example 3 was applied to the surface of the base layer B3 of the substrate of Example 3 by spin coating to form a coating film. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 3 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating film, thereby forming the low refractive index film of Example 3. Thus, a laminate of Example 3 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 3, the low refractive index film of Example 3 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 3 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 3 at the D line was 0.25%, and the film thickness of the low refractive index film of Example 3 was 120 nm, and the refractive index was 1.19. On a mass basis, the low refractive index film in Example 3 includes 19% silica forming an adhesive, 51% silsesquioxane, and 30% hollow silica particles.

[0085] <Example 4> The low refractive index film liquid composition of Example 4 was prepared in the same manner as Example 1 except for the following aspects. Assuming that the mass ratio of each component relative to the mass of the entire solid component of the low refractive index film liquid composition is equal to the mass ratio of each component relative to the mass of the low refractive index film, the addition amounts of TEOS, MTES, and the sol containing hollow silica particles were adjusted so that the mass ratio of each component relative to the mass of the low refractive index film became the values ​​shown in Table 2.

[0086] On one main surface of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned in advance by alkali cleaning, the same base layer liquid composition B as in Example 2 was applied by spin coating to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer B4, thereby obtaining the substrate of Example 4. The thickness of the base layer B4 was 11 nm. The contact angle of a water droplet on the surface of the base layer B4 was 42°, and the arithmetic mean roughness Ra of the surface of the base layer B4 was 13 nm.

[0087] The liquid composition for the low refractive index film of Example 4 was applied to the surface of the base layer B4 of the substrate of Example 4 by spin coating to form a coating. The coating immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 4 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating to form the low refractive index film of Example 4. Thus, a laminate of Example 4 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 4, the low refractive index film of Example 4 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 4 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 4 at the D line was 0.62%, and the film thickness of the low refractive index film of Example 4 was 123 nm, and the refractive index was 1.15. On a mass basis, the low refractive index film in Example 4 includes 17% of silica forming an adhesive, 43% of silsesquioxane, and 40% of hollow silica particles.

[0088] <Example 5> The low refractive index film liquid composition of Example 5 was prepared in the same manner as Example 1 except for the following aspects. Assuming that the mass ratio of each component relative to the mass of the entire solid component of the low refractive index film liquid composition is equal to the mass ratio of each component relative to the mass of the low refractive index film, the addition amounts of TEOS, MTES, and the sol containing hollow silica particles were adjusted so that the mass ratio of each component relative to the mass of the low refractive index film became the values ​​shown in Table 2.

[0089] On one main surface of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned in advance by alkali cleaning, the same base layer liquid composition B as in Example 2 was applied by spin coating to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer B5, thereby obtaining a substrate of Example 5. The thickness of the base layer B5 was 11 nm. The contact angle of a water droplet on the surface of the base layer B5 was 44°, and the arithmetic mean roughness Ra of the surface of the base layer B5 was 16 nm.

[0090] The liquid composition for the low refractive index film of Example 5 was applied to the surface of the base layer B5 of the substrate of Example 5 by spin coating to form a coating film. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 5 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating film, thereby forming the low refractive index film of Example 5. Thus, a laminate of Example 5 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 5, the low refractive index film of Example 5 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 5 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 5 at the D line was 1.13%, and the film thickness of the low refractive index film of Example 5 was 121 nm, and the refractive index was 1.12. On a mass basis, the low refractive index film in Example 5 includes 14% silica forming an adhesive, 36% silsesquioxane, and 50% hollow silica particles.

[0091] <Example 6> The low refractive index film liquid composition of Example 6 was prepared in the same manner as Example 1 except for the following aspects. Assuming that the mass ratio of each component relative to the mass of the entire solid component of the low refractive index film liquid composition is equal to the mass ratio of each component relative to the mass of the low refractive index film, the added amounts of TEOS, MTES, and the sol containing hollow silica particles were adjusted so that the mass ratio of each component relative to the mass of the low refractive index film became the values ​​shown in Table 2.

[0092] The same base layer liquid composition B as in Example 2 was applied by spin coating on both main surfaces of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned in advance by alkali cleaning to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer B6, thereby obtaining a substrate of Example 6. The thickness of the base layer B6 was 14 nm. The contact angle of a water droplet on the surface of the base layer B6 was 41°, and the arithmetic mean roughness Ra of the surface of the base layer B6 was 12 nm.

[0093] The liquid composition for the low refractive index film of Example 6 was applied to the surface of the base layer B6 of the substrate of Example 6 by spin coating to form a coating film. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 6 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating film, thereby forming the low refractive index film of Example 6. Thus, a laminate of Example 6 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 6, the low refractive index film of Example 6 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 6 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 6 at the D line was 1.50%, and the film thickness of the low refractive index film of Example 6 was 122 nm, and the refractive index was 1.10. On a mass basis, the low refractive index film in Example 6 includes 8% of silica forming an adhesive, 22% of silsesquioxane, and 70% of hollow silica particles.

[0094] <Example 7> 97 g of ethanol was added to 3 g of n-octyltrichlorosilane (manufactured by Tokyo Chemical Industry Co., Ltd.) to obtain a liquid composition C for a base layer.

[0095] On one main surface of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned by alkali cleaning in advance, the base layer liquid composition C was applied by spin coating to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer C7, thereby obtaining the substrate of Example 7. The thickness of the base layer C7 was 13 nm. The contact angle of a water droplet on the surface of the base layer C7 was 64°, and the arithmetic mean roughness Ra of the surface of the base layer C7 was 23 nm.

[0096] The surface of the base layer C7 of the substrate of Example 7 was coated with the same liquid composition for low refractive index film as in Example 1 by spin coating to form a coating film. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 7 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating film, thereby forming a low refractive index film of Example 7. Thus, a laminate of Example 7 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 7, the low refractive index film of Example 7 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 7 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 7 at the D line was 0.45%, and the film thickness of the low refractive index film of Example 7 was 119 nm, and the refractive index was 1.17. On a mass basis, the low refractive index film in Example 7 includes 13% silica forming an adhesive, 33% silsesquioxane, and 54% hollow silica particles.

[0097] <Example 8> 97 g of ethanol was added to 3 g of 1H,1H,2H,2H-perfluorooctyltrichlorosilane (manufactured by Tokyo Chemical Industry Co., Ltd.) to obtain a liquid composition D for a base layer.

[0098] On one main surface of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned in advance by alkali cleaning, the base layer liquid composition D was applied by spin coating to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer D8, thereby obtaining a substrate of Example 8. The thickness of the base layer D8 was 11 nm. The contact angle of a water droplet on the surface of the base layer D8 was 118°, and the arithmetic mean roughness Ra of the surface of the base layer D8 was 35 nm.

[0099] The same liquid composition for low refractive index film as in Example 1 was applied to the surface of the base layer D8 of the substrate of Example 8 by spin coating to form a coating. The coating immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 8 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating to form a low refractive index film of Example 8. Thus, a laminate of Example 8 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 8, the low refractive index film of Example 8 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 8 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 8 at the D line was 0.55%, and the film thickness of the low refractive index film of Example 8 was 120 nm, and the refractive index was 1.16. On a mass basis, the low refractive index film in Example 8 includes 13% silica forming an adhesive, 33% silsesquioxane, and 54% hollow silica particles.

[0100] <Example 9> A polycarbonate (PC) substrate (manufactured by AS ONE, product number: PCC0050503, size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.59) was cleaned in ultrapure water for 15 minutes using an ultrasonic cleaner. Thereafter, the PC substrate was cleaned with a commercially available alkaline cleaning solution for 15 minutes and then cleaned in ultrapure water for 15 minutes. Subsequently, the surface of the PC substrate was corona treated for 10 minutes using a corona surface treatment device (manufactured by Shinko Electric Instrument Co., Ltd., model: Corona Master PS-1M) at an output of 14 kV using the same method and conditions as in Example 1 to obtain the substrate of Example 9. The contact angle of a water droplet on the surface of the PC substrate after the corona treatment was 19°, and the arithmetic mean roughness Ra of the surface of the PC substrate after the corona treatment was 34 nm.

[0101] The same liquid composition for low refractive index film as in Example 1 was applied to one main surface of the substrate of Example 9 by spin coating. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 9 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating film, thereby forming the low refractive index film of Example 9. Thus, a laminate of Example 9 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 9, the low refractive index film of Example 9 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 9 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 9 at the D line was 0.57%, and the film thickness of the low refractive index film of Example 9 was 122 nm, and the refractive index was 1.18. On a mass basis, the low refractive index film in Example 9 includes 13% silica forming an adhesive, 33% silsesquioxane, and 54% hollow silica particles.

[0102] <Example 10> Using an ultrasonic cleaning machine, a substrate of the same type as the PC substrate used in Example 9 was cleaned in ultrapure water for 15 minutes. Thereafter, the PC substrate was cleaned with a commercially available alkaline cleaning solution for 15 minutes, and then cleaned in ultrapure water for 15 minutes. Subsequently, corona treatment was performed in the same manner and under the same conditions as in Example 1, except that the treatment time was adjusted to 1 minute, to obtain the substrate of Example 10. The contact angle of a water drop on the surface of the PC substrate after the corona treatment was 37°, and the arithmetic mean roughness Ra of the surface of the PC substrate after the corona treatment was 27 nm.

[0103] The same liquid composition for low refractive index film as in Example 1 was applied to one main surface of the substrate of Example 10 by spin coating. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 10 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating film, thereby forming the low refractive index film of Example 10. Thus, a laminate of Example 10 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 10, the low refractive index film of Example 10 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 10 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 10 at the D line was 0.73%, and the film thickness of the low refractive index film of Example 10 was 121 nm, and the refractive index was 1.17. As shown in Table 2, based on mass, the low refractive index film in Example 10 includes 13% silica forming a binder, 33% silsesquioxane, and 54% hollow silica particles.

[0104] <Example 11> Using an ultrasonic cleaner, a substrate of the same type as the PC substrate used in Example 9 was cleaned in ultrapure water for 15 minutes. Thereafter, the PC substrate was cleaned with a commercially available alkaline cleaning solution for 15 minutes, and then cleaned in ultrapure water for 15 minutes to obtain the substrate of Example 11. The contact angle of a water droplet on the surface of the substrate of Example 11 was 71°, and the arithmetic mean roughness Ra of the surface of the substrate of Example 11 was 21 nm.

[0105] The same liquid composition for low refractive index film as in Example 1 was applied to one main surface of the substrate of Example 11 by spin coating. The coating film immediately after coating had a good and uniform appearance. Thereafter, the substrate of Example 11 was placed in an oven maintained at 200° C. for 10 minutes to dry the coating film, thereby forming the low refractive index film of Example 11. Thus, a laminate of Example 11 having a substrate and a low refractive index film formed on the substrate was obtained. According to the appearance observation of the low refractive index film of Example 11, the low refractive index film of Example 11 had a uniform thickness. After measuring the spectral reflectance of the laminate of Example 11 in the same manner as in Example 1, various parameters were calculated. The reflectance of the laminate of Example 11 at the D line was 0.84%, and the film thickness of the low refractive index film of Example 11 was 123 nm, and the refractive index was 1.16. As shown in Table 2, based on mass, the low refractive index film of Example 11 includes 13% silica forming an adhesive, 33% silsesquioxane, and 54% hollow silica particles.

[0106] <Comparative Example 1> 99.5 g of decamethylcyclopentasiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., product name KF-995) was stirred, and at the same time, 0.5 g of tetrachlorosilane (SiCl 4) manufactured by Shin-Etsu Chemical Co., Ltd. was added to the decamethylcyclopentasiloxane to prepare a base layer composition E1 having silicon dioxide as a main component. In addition, 98 g of decamethylcyclopentasiloxane was stirred, and at the same time, 2 g of heptadecafluorodecyltrichlorosilane (CF 3(CF 2) 7(CH 2) 2SiCl 3) was added to the decamethylcyclopentasiloxane to prepare a base layer composition E2.

[0107] The base layer composition E1 was applied by flow coating on one main surface of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned by alkali cleaning in advance to form a coating film, and the coating film was left to stand in a wet state for one minute. Then, the base layer composition E1 was applied by flow coating on the coating film under the same conditions, and the coating material was left to stand in a wet state for one minute. Next, the base layer composition E2 was applied by flow coating on the wet coating film of the base layer composition E1 on the surface of the glass substrate under the same conditions as the above conditions, and the coating material was left to stand in a wet state for one minute. Then, the remaining components of the base layer composition on the surface were completely washed off with ethanol, and the coating film was naturally dried to form a base layer E14, and the substrate of Comparative Example 1 was obtained. The base layer E14 has water repellency due to the effect of the base layer composition E2. In addition, it was confirmed that microparticle-shaped protrusions and columnar protrusions were formed on the surface of the base layer E14 due to the effect of the base layer composition E1. The thickness of the base layer E14 was 14 nm. The contact angle of a water drop on the surface of the base layer E14 was 157°, and the arithmetic mean roughness Ra of the surface of the base layer E14 was 43 nm.

[0108] The low refractive index film liquid composition of Comparative Example 1 was applied by spin coating on the surface of the base layer E14 of the substrate of Comparative Example 1. However, stripe-shaped coating unevenness occurred across one side of the surface of the substrate of Comparative Example 1, and a uniform film was not obtained.

[0109] <Comparative Example 2> 0.6 g of tetraethoxysilane (TEOS) (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.18 g of methyltriethoxysilane (MTES) (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.82 g of 0.3 mass % formic acid (manufactured by Kishida Chemical Co., Ltd.), 3 g of silica sol (Nissan Chemical Co., Ltd., product name: Snowtex MP-2040, average particle size: 200 nm), and 22.4 g of ethanol (manufactured by Kishida Chemical Co., Ltd.) were mixed and reacted at 35° C. for 3 hours. Ethanol was added to the mixed solution, and the total solid content of silica from tetraethoxysilane and methylsilsesquioxane (MeSq) from methyltriethoxysilane was adjusted to 5 mass %, to obtain a liquid composition F for an underlayer.

[0110] On one main surface of a glass substrate (size: 40 mm×40 mm, thickness: 1 mm, refractive index: 1.52) made of float glass and cleaned in advance by alkali cleaning, the liquid composition F for base layer was applied by spin coating to form a coating film. Then, the coating film was dried in an oven at 200° C. for 10 minutes to form a base layer F15, thereby obtaining a substrate of Comparative Example 2. The thickness of the base layer F15 was 170 nm. The contact angle of a water droplet on the surface of the base layer F15 was 52°, and the arithmetic mean roughness Ra of the surface of the base layer F15 was 150 nm.

[0111] The low refractive index film liquid composition of Comparative Example 1 was applied by spin coating to the surface of the base layer F15 of the substrate of Comparative Example 2. However, streaky coating unevenness occurred over one surface of the substrate of Comparative Example 2, and a uniform film was not obtained.

[0112] [Table 1] substrate Material Preprocessing Basal layer Save time [Hour] Surface parameters Alkali Cleaning Corona deal with [minute] type Film thickness [nm] Arithmetic mean roughness Ra[nm] Contact angle of water drop [°] Example 1 Glass ○ 10 - - 12 0.5 32 Example 2 Glass ○ - B2 13 - 17 45 Example 3 Glass 〇 - B3 13 - 11 43 Example 4 Glass 〇 - B4 11 - 13 42 Example 5 Glass 〇 - B5 11 - 16 44 Example 6 Glass 〇 - B6 14 - 12 41 Example 7 Glass 〇 - C7 13 - twenty three 64 Example 8 Glass 〇 - D8 11 - 35 118 Example 9 PC 〇 10 - - - 34 19 Example 10 PC 〇 1 - - - 27 37 Embodiment 11 PC 〇 - - - - twenty one 71 Comparative Example 1 Glass 〇 - E14 14 - 43 157 Comparative Example 2 Glass 〇 - F15 170 - 150 52

[0113] [Table 2] Example Laminated body, low refractive index film Hollow particle Adhesive Adhesive / Hollow particles Gap Optical properties Film thickness [nm] Film forming properties Wear resistance Quality Ratio Whp [quality%] Silicon dioxide mass ratio [quality%] SqF Quality Ratio [quality%] Wb [quality%] Wb / Whp ρv1 [ / μm 2] Vv1 [%] Reflectivity (Line D) [%] Refractive Index (Line D) Haze [%] Example 1 54 13 33 46 0.85 19 36 0.53 1.16 0.1 121 A A Example 2 20 twenty three 57 80 4.00 8 9 0.1≧ 1.23 0.2 121 A A Example 3 30 19 51 70 2.33 13 26 0.25 1.19 0.4 120 A A Example 4 40 17 43 60 1.50 42 42 0.62 1.15 0.3 123 A A Example 5 50 14 36 50 1.00 62 53 1.13 1.12 0.4 121 A A Example 6 70 8 twenty two 30 0.43 83 61 1.50 1.10 0.3 122 A A Example 7 54 13 33 46 0.85 18 32 0.45 1.17 0.2 119 A A Example 8 54 13 33 46 0.85 twenty four 36 0.55 1.16 0.2 120 A A Example 9 54 13 33 46 0.85 16 29 0.57 1.18 0.3 122 A A Example 10 54 13 33 46 0.85 twenty one 34 0.73 1.17 0.4 121 A A Embodiment 11 54 13 33 46 0.85 twenty three 36 0.84 1.16 0.2 123 A A Comparative Example 1 54 13 33 46 0.85 36 41 - - 0.4 121 F A Comparative Example 2 54 13 33 46 0.85 32 43 - - 5.2 120 F F

[0114] 1a, 1b, 1c, 1d, 1e: laminated body 10: Low refractive index film 11: First floor 12: Second layer 13: Hollow particles 14: Adhesive 20: Base material

Claims

1. A laminate comprising, sequentially, a substrate and a low-refractive-index film having a refractive index of 1.01 or more and 1.30 or less, wherein the low-refractive-index film comprises hollow particles, an adhesive, and voids, wherein the voids are spaces not occupied by the hollow particles and the adhesive, and the internal space of the hollow particles is not part of the voids, and the number density of the voids having a cross-sectional area of ​​1000 nm² or more in the cross-section of the low-refractive-index film is 13 / μm² or more and 100 / μm² or less.

2. As in request item 1, the layered body, wherein, The aforementioned low-refractive-index film has a first layer and a second layer sequentially from the side closest to the substrate, and the first layer has a thickness of less than half the thickness of the low-refractive-index film and less than 200 nm. The first layer has voids that satisfy at least one of the following conditions (I) and (II): (I) the number density of voids having a cross-sectional area of ​​more than 1000 nm2 in the cross-section of the first layer is less than 100 / μm2; (II) the ratio of the cross-sectional area of ​​the voids in the cross-section to the area of ​​the cross-section of the first layer is less than 70%.

3. As in request item 2, the stacked volume, wherein, The first layer satisfies the condition (I) above, and the number density of the voids with a cross-sectional area of ​​1000 nm2 or more in the cross-section of the first layer is greater than the number density of the voids with a cross-sectional area of ​​1000 nm2 or more in the cross-section of the second layer.

4. As in request item 2, the stacked volume, wherein, The first layer satisfies the conditions of (II) above, and the ratio of the cross-sectional area of ​​the void in the cross-section of the first layer to the area of ​​the cross-section of the first layer is higher than the ratio of the cross-sectional area of ​​the void in the cross-section of the second layer to the area of ​​the cross-section of the second layer.

5. As in request item 3, the stacked volume, wherein, The first layer satisfies the conditions of (II) above, and the ratio of the cross-sectional area of ​​the void in the cross-section of the first layer to the area of ​​the cross-section of the first layer is higher than the ratio of the cross-sectional area of ​​the void in the cross-section of the second layer to the area of ​​the cross-section of the second layer.

6. As in request item 1, the stacked volume, wherein, The low refractive index film has a thickness dt of 70 nm or more. When 70 nm ≦ dt ≦ 400 nm, the thickness d1 of the first layer is equal to dt / 2. When 400 nm < dt, the thickness d1 of the first layer is equal to 200 nm.

7. As in request item 1, the stacked volume, wherein, The average particle size of the hollow particles mentioned above is between 20 nm and 100 nm.

8. As in request item 1, the stacked volume, wherein, Based on mass standards, the ratio of the content of the above-mentioned adhesive to the content of the above-mentioned hollow particles is 0.2 to 20.

9. As in request item 1, the layered body, wherein, The contact angle of water droplets on the surface of the aforementioned substrate is between 5° and 140°.

10. As in request item 1, the stacked volume, wherein, The substrate has a surface layer on its surface, and the surface layer contains at least one of silicon dioxide or silsesquioxane.

11. As in request item 10, the stacked volume, wherein, The surface layer disposed on the surface of the above-mentioned substrate has a thickness of 5 to 50 nm.

12. The laminate of any one of claims 1 to 11, wherein at least one of an antifog film, a water-repellent film, an oil-repellent film, and a hydrophilic film is disposed between the substrate and the low refractive index film.

13. A method for manufacturing a laminate, which is the method for manufacturing a laminate of claim 1, comprising: depositing the low refractive index film on the surface of the substrate; and on the surface of the substrate, the arithmetic mean roughness Ra is less than or equal to the average particle size of the hollow particles, and on the surface of the substrate, the contact angle α of a water droplet is more than 5° and less than 140°.

14. A method for manufacturing a laminate as claimed in claim 13, comprising: providing a surface layer on the surface of the substrate, and providing the low refractive index film on the surface layer; wherein the arithmetic mean roughness Ra of the surface of the surface layer is less than or equal to the average particle size of the hollow particles, and the contact angle α of water droplets on the surface of the surface layer is more than 5° and less than 140°.

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