transparent laminate

Abstract

To provide a cover member also usable for a purpose other than protection of an article.SOLUTION: A cover member includes: a transparent substrate having a first principal plane and a second principal plane; and a transparent first functional layer laminated on the first principal plane of the substrate.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a transparent laminate.

Background Art

[0002] Transparent substrates such as glass plates and resin plates are used in various applications. For example, they may be used as cover members for protecting articles (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, such cover members are required not only to simply protect articles but also to have other functions. The present invention has been made to solve the above problems and aims to provide a cover member that can also be used for applications other than protecting articles.

Means for Solving the Problems

[0005] Item 1. A transparent substrate having a first main surface and a second main surface, A transparent first functional layer laminated on the first main surface of the substrate, A transparent laminate comprising:

[0006] Item 2. The transparent laminate according to Item 1, wherein the first functional layer has an anti-fogging function.

[0007] Item 3. The transparent laminate according to Item 1 or 2, wherein the surface roughness Ra of the first functional layer is 1 to 1000 nm.

[0008] Item 4. The first functional layer is A base film having a first main surface and a second main surface, An adhesive layer laminated on the second main surface of the base film, An anti-fogging layer laminated on the first main surface of the base film, Equipped with, The transparent laminate according to any one of claims 1 to 3, wherein the base film is fixed to the first main surface of the substrate via the adhesive layer.

[0009] Item 5. The first functional layer comprises an adhesive layer and an anti-fogging layer, The transparent laminate according to any one of claims 1 to 3, wherein the anti-fogging layer is fixed to the first main surface of the substrate via the adhesive layer.

[0010] Item 6. The first functional layer comprises an anti-fog layer, The transparent laminate according to any one of claims 1 to 3, wherein the anti-fogging layer is laminated on the first main surface of the substrate.

[0011] Item 7. The transparent laminate according to any one of items 4 to 6, wherein the anti-fogging layer has a moisture-absorbing layer containing a hygroscopic resin material.

[0012] Item 8. The anti-fogging layer comprises the moisture-absorbing layer and a hydrophilic layer laminated on the moisture-absorbing layer and having hydrophilic properties. The transparent laminate according to item 7, comprising,

[0013] Item 9. The transparent laminate according to Item 8, wherein the hydrophilic layer of the anti-fogging layer contains a polyether-modified dimethylsiloxane represented by the following formula (A). [ka] However, m is an integer greater than or equal to 2, and n, x, and y are independent integers greater than or equal to 1. R 1 is a hydrogen atom or a methyl group, R 2 These are alkyl groups with 1 to 3 carbon atoms.

[0014] Item 10. In the above formula (A), m is an integer between 1 and 3. n is an integer between 3 and 600. If y / (x+y) is between 0.01 and 1, A transparent laminate as described in item 9, having an average molecular weight of 3,000 to 300,000.

[0015] Item 11. The transparent laminate according to Item 7, wherein the anti-fogging layer has a hydrophilic agent dispersed in the moisture-absorbing layer.

[0016] Item 12. The transparent laminate according to Item 11, wherein the anti-fogging layer contains a solvent having a boiling point of 100°C or more and 300°C or less.

[0017] Item 13. The transparent laminate according to Item 12, wherein the solvent has an alcohol group.

[0018] Item 14. The transparent laminate according to any one of items 11 to 13, wherein the anti-fog layer has anti-fog properties after being subjected to a predetermined number of abrasions with a cloth soaked in alcohol.

[0019] Item 15. A transparent laminate according to any one of items 11 to 14, wherein the anti-fogging layer has anti-fogging properties after a prescribed constant temperature and humidity test.

[0020] Item 16. The transparent laminate according to any one of items 11 to 15, wherein the anti-fogging layer is formed by a single layer.

[0021] Item 17. A transparent laminate according to any one of items 1 to 6, wherein the first functional layer is mainly composed of an inorganic compound.

[0022] Item 18. The visible light transmittance is 85% or higher. A transparent laminate as described in item 17, wherein the visible light reflectance is 10% or less.

[0023] Item 19. The transparent laminate according to item 17 or 18, wherein the minimum transmittance in the visible light wavelength range is within 5% of the transmittance of the substrate.

[0024] Item 20. The transparent laminate according to any one of items 17 to 19, wherein the maximum reflectance in the visible light wavelength range is within 5% of the reflectance of the substrate.

[0025] Section 21. Regarding reflectance in the visible light wavelength range, A transparent laminate according to any one of items 17 to 20, satisfying the condition 1 ≤ maximum reflectance / minimum reflectance ≤ 1.5.

[0026] Item 22. The transparent laminate according to any one of items 17 to 21, wherein the first functional layer comprises inorganic fine particles and an inorganic binder.

[0027] Item 23. The transparent laminate according to Item 22, wherein the film thickness of the first functional layer is 2 times or less the particle size of the inorganic fine particles.

[0028] Item 24. The transparent laminate according to item 22 or 23, wherein the inorganic fine particles are formed of SiO2.

[0029] Item 25. The transparent laminate according to Item 24, wherein the SiO2 content in the first functional layer is 28% by mass or less.

[0030] Item 26. The transparent laminate according to any one of items 22 to 25, wherein the first functional layer contains photocatalytic nanoparticles.

[0031] Item 27. The transparent laminate according to Item 26, wherein the photocatalytic particles are formed of an oxide or oxynitride mainly composed of titanium, tungsten, or iron.

[0032] Item 28. The transparent laminate according to item 26 or 27, wherein the content of the photocatalytic particles is 40% by mass or less.

[0033] Item 29. The transparent laminate according to any one of items 26 to 28, wherein the inorganic binder content is 30% by mass or more.

[0034] Item 30. A transparent laminate according to any one of items 17 to 29, wherein the first functional layer has anti-fogging properties after being immersed in water for a predetermined time.

[0035] Item 31. The transparent laminate according to any one of items 17 to 30, wherein the first functional layer has anti-fogging properties after being subjected to a predetermined number of abrasions with a cloth soaked in alcohol.

[0036] Item 32. The transparent laminate according to any one of items 17 to 31, wherein the first functional layer has anti-fogging properties after being subjected to a predetermined number of abrasions with a cloth soaked in alcohol and then irradiated with ultraviolet light.

[0037] Item 33. A transparent laminate according to any one of items 17 to 32, wherein the first functional layer exhibits anti-fogging properties when irradiated with ultraviolet light after a prescribed constant temperature and humidity test.

[0038] Item 34. A transparent laminate according to any one of items 17 to 33, used as a cover component for a surveillance camera, which is placed outdoors.

[0039] Item 35. The transparent laminate according to item 34, wherein the surveillance camera is equipped with an ultraviolet irradiation device.

[0040] Item 36. The transparent laminate according to item 34 or 35, wherein the first functional layer is positioned to face the surveillance camera.

[0041] Item 37. The transparent laminate according to Item 34, wherein the first functional layer is positioned to face away from the surveillance camera.

[0042] Item 38. The transparent laminate according to any one of items 2 to 10, further comprising a second functional layer laminated on the first functional layer and having moisture permeability.

[0043] Section 39. The first functional layer is formed from an organic-inorganic composite material. The transparent laminate according to item 38, wherein the refractive index of the second functional layer is smaller than that of the first functional layer.

[0044] Item 40. The transparent laminate according to item 38 or 39, wherein the second functional layer is a single layer.

[0045] Item 41. The transparent laminate according to Item 40, wherein the refractive index of the second functional layer is 1.10 to 1.45.

[0046] Item 42. The transparent laminate according to Item 41, wherein when the refractive index of the first functional layer is X, the refractive index of the second functional layer is √X ± 0.1.

[0047] Item 43. The transparent laminate according to item 42, wherein the second functional layer contains hollow particles and a binder that binds the hollow particles together.

[0048] Item 44. The transparent laminate according to Item 43, wherein the refractive index of the hollow particles is 1.15 to 2.70.

[0049] Item 45. The transparent laminate according to item 43 or 44, wherein the average particle size of the hollow particles is 20 to 100 nm.

[0050] Item 46. The transparent laminate according to any one of items 43 to 45, wherein the hollow particles are selected from the group consisting of silica, magnesium fluoride, alumina, aluminosilicate, titania, and zirconia.

[0051] Item 47. The transparent laminate according to any one of items 38 to 46, wherein the second functional layer contains a solvent having a boiling point of 100°C or more and 300°C or less.

[0052] Item 48. The transparent laminate according to Item 47, wherein the solvent is mainly composed of 3-methoxy-3methyl-1-butanol.

[0053] Item 49. The second functional layer contains the solvent at a concentration of 1 ppb or more and 5 g / cm³. 3 The following contains, item 4 A transparent laminate as described in 7 or 48.

[0054] Item 50. The transparent laminate according to any one of items 43 to 49, wherein the binder contains at least one of polysilsesquioxane and silica.

[0055] Item 51. A transparent laminate according to any one of items 43 to 50, wherein the void ratio of the second functional layer is 0 to 70 vol%.

[0056] Item 52. The transparent laminate according to item 38 or 39, wherein the second functional layer comprises a first layer laminated on the first functional layer and a second layer laminated on the first layer having a lower refractive index than the first layer.

[0057] Item 53. The refractive index of the first layer is 1.35 to 1.55. The transparent laminate according to item 52, wherein the refractive index of the second layer is 1.10 to 1.25.

[0058] Item 54. The transparent laminate according to item 53, wherein the second layer contains hollow particles and a binder that binds the hollow particles together.

[0059] Item 55. The transparent laminate according to Item 54, wherein the refractive index of the hollow particles is 1.15 to 2.70.

[0060] Item 56. The transparent laminate according to item 54 or 55, wherein the average particle size of the hollow particles is 20 to 100 nm.

[0061] Item 57. The transparent laminate according to any one of items 54 to 56, wherein the hollow particles are selected from the group consisting of silica, magnesium fluoride, alumina, aluminum silicate, titania, and zirconia.

[0062] Item 58. The transparent laminate according to any one of items 54 to 57, wherein the binder contains at least one of polysilsesquioxane and silica.

[0063] Item 59. A transparent laminate according to any one of items 54 to 58, wherein the void ratio of the second layer is 0 to 70 vol%.

[0064] Item 60. A transparent laminate according to any one of items 54 to 59, wherein the first layer contains the binder of the second layer.

[0065] Item 61. A transparent laminate according to any one of items 38 to 60, wherein the flexural modulus of the second functional layer is 1 to 10 GPa.

[0066] Item 62. The transparent laminate according to any one of items 38 to 61, wherein the flexural modulus of the second functional layer overlaps with the flexural modulus of the first functional layer.

[0067] Item 63. A transparent laminate according to any one of items 38 to 62, wherein the difference between the coefficient of thermal expansion of the first functional layer and the coefficient of thermal expansion of the second functional layer is 50 ppm / °C or less.

[0068] Item 64. The transparent laminate according to Item 1, wherein the first functional layer has an anti-reflective function.

[0069] Item 65. The transparent laminate according to item 64, wherein the first functional layer is formed of a film in which an adhesive layer, a base sheet, and an anti-reflective layer are laminated in that order.

[0070] Item 66. The transparent laminate according to Item 65, wherein the refractive index of the anti-reflective layer of the first functional layer is 1.10 to 1.45.

[0071] Item 67. The transparent laminate according to item 65 or 66, wherein the anti-reflective layer of the first functional layer contains hollow particles and a binder that binds the hollow particles together.

[0072] Item 68. The transparent laminate according to Item 67, wherein the refractive index of the hollow particles is 1.15 to 2.70.

[0073] Item 69. The transparent laminate according to item 67 or 68, wherein the average particle size of the hollow particles is 20 to 100 nm.

[0074] Item 70. The transparent laminate according to any one of items 65 to 69, wherein the anti-reflective layer contains a second solvent having a boiling point greater than the boiling point of water and less than or equal to the heat resistance temperature of the substrate.

[0075] Item 71. The transparent laminate according to item 70, wherein the second solvent is mainly composed of 3-methoxy-3methyl-1-butanol.

[0076] Item 72. The first functional layer contains the second solvent at a concentration of 1 ppb or more and 5 g / cm³. 3 A transparent laminate according to item 70 or 71, containing % or less.

[0077] Item 73. The transparent laminate according to any one of items 2 to 72, wherein the substrate is glass.

[0078] Item 74. The transparent laminate according to any one of items 2 to 73, wherein the substrate is float glass manufactured by the float process, and the concentration of tin oxide on the first main surface is lower than the concentration of tin oxide on the second main surface.

[0079] Item 75. The transparent laminate according to any one of items 2 to 73, wherein the substrate is float glass manufactured by the float process, and the concentration of tin oxide on the first main surface is higher than the concentration of tin oxide on the second main surface.

[0080] Item 76. The transparent laminate according to any one of items 1 to 75, further comprising a third functional layer laminated on the second main surface of the substrate. [Effects of the Invention]

[0081] According to the present invention, since a transparent functional layer is laminated on the surface of the substrate, by giving this functional layer a function, it can be used for purposes other than protecting articles. [Brief explanation of the drawing]

[0082] [Figure 1] This is a cross-sectional view showing a first embodiment of the cover member according to the present invention. [Figure 2] It is a schematic diagram showing an example in which a cover member is provided in front of the lens of the imaging device. [Figure 3] It is a schematic diagram showing an example in which a cover member is provided in front of the lens of the imaging device housed in the housing. [Figure 4] It is a graph showing Examples 1 to 3 and the transmittance of the base material. [Figure 5] It is a graph showing Examples 1 to 3 and the reflectance of the base material. [Figure 6] It is a cross-sectional view showing a second embodiment of the cover member according to the present invention. [Figure 7] It is a cross-sectional view showing a schematic configuration of the second functional layer as an antireflection layer. [Figure 8] It is a cross-sectional view showing another example of the cover member of the second embodiment. [Figure 9] It is a cross-sectional view showing another example of the cover member of the second embodiment. [Figure 10] It is a cross-sectional view showing another example of the cover member of the second embodiment. [Figure 11] It is a graph showing the single-sided reflectance of Examples 23 and 26. [Figure 12] It shows the single-sided reflectance of 400 to 700 nm of the film on which the antireflection film of Examples 28 to 30 is formed.

Mode for Carrying Out the Invention

[0083] <A. First Embodiment> Hereinafter, a first embodiment when the transparent laminate according to the present invention is applied to a cover member will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the cover member.

[0084] <1. Outline of the Cover Member> As will be described later, the cover member according to this embodiment is positioned in front of the lens of an imaging device such as a camera to protect the lens. Specifically, as shown in Figure 1, the cover member 10 has a transparent base material 1 having a first main surface 11 and a second main surface 12, and a first functional layer 2 laminated on the first main surface 11 of the base material 1. Each member will be described in detail below.

[0085] <2. Base material> The base material 1 can be formed from a translucent resin material (organic polymer material) or a glass plate. The shape of the base material is not particularly limited and can be determined as appropriate according to various applications, such as circular, rectangular, polygonal, or irregular shapes, as described later. Specific examples will be given below.

[0086] <2-1. Resin Materials> The resin material is not particularly limited as long as it is translucent as described above, but for example, it can be made from polycarbonate (PC), acrylonitrile / styrene resin (AS), acrylonitrile / butadiene / styrene resin (ABS), methacrylic resin (PMMA), vinyl chloride (PVC), triacetylcellulose (TAC), or a material containing a combination of these.

[0087] <2-2. Glass Plate> The glass plate 1 is not particularly limited, and any known transparent glass plate can be used. For example, various glass plates such as float glass, heat-absorbing glass, clear glass, green glass, UV green glass, and soda-lime glass can be used.

[0088] Below are examples of the compositions of clear glass, heat-absorbing glass, soda-lime glass, and float glass.

[0089] <2-2-1. Clear Glass> SiO2: 70~73% by mass Al2O3:0.6~2.4% by mass CaO: 7~12% by mass MgO: 1.0~4.5% by mass R2O: 13-15% by mass (R is an alkali metal) Total iron oxide (T-Fe2O3) converted to Fe2O3: 0.08~0.14% by mass

[0090] <2-2-2. Heat-absorbing glass> The composition of heat-absorbing glass can be, for example, based on the composition of clear glass, with a ratio of total iron oxide (T-Fe2O3) converted to Fe2O3 of 0.4 to 1.3 mass%, a ratio of CeO2 of 0 to 2 mass%, a ratio of TiO2 of 0 to 0.5 mass%, and a reduction in the glass skeleton components (mainly SiO2 and Al2O3) by the amount of increase in T-Fe2O3, CeO2, and TiO2.

[0091] <2-2-3. Soda-lime glass> SiO2: 65~80% by mass Al2O3: 0~5% by mass CaO: 5~15% by mass MgO: 2% by mass or more NaO: 10~18% by mass K2O: 0~5% by mass MgO+CaO: 5~15% by mass Na2O+K2O: 10~20% by mass SO3:0.05~0.3% by mass B2O3:0~5% by mass Total iron oxide (T-Fe2O3) converted to Fe2O3: 0.02~0.03% by mass

[0092] <2-2-4. Float glass> SiO265~80% Al2O30~5% MgO 0-20% CaO 0-20% Na2O 10-20% K2O 0-5%

[0093] <2-2-4-1. High-transparency float glass> SiO2 66-72% Al2O3 2-4% MgO 8-15% CaO 1-8% Na2O 12-16% K2O 0-1% Includes, The MgO + CaO content is in the range of 12-17%. The molar ratio CaO / (MgO+CaO) is 0.1 to 0.4

[0094] The following describes the individual components that make up the composition of this float glass. (SiO2) SiO2 is the main component of the glass plate 1, and if its content is too low, the chemical durability, such as water resistance, and heat resistance of the glass will decrease. On the other hand, if the SiO2 content is too high, the viscosity of the glass plate 1 will increase at high temperatures, making melting and molding difficult. Therefore, an appropriate SiO2 content is in the range of 66 to 72 mol%, and 67 to 70 mol% is preferred.

[0095] (Al2O3) Al2O3 is a component that improves the chemical durability of glass plate 1, such as its water resistance, and further increases the surface compressive stress after chemical strengthening by facilitating the movement of alkali metal ions in the glass, as well as increasing the stress layer depth. On the other hand, if the Al2O3 content is too high, it increases the viscosity of the glass melt, increases T2 and T4, and deteriorates the clarity of the glass melt, making it difficult to manufacture high-quality glass plates. In the float process, the working temperature is when the glass viscosity is 10 4 This is the temperature at which the glass viscosity becomes dPa·s, and is hereafter referred to as T4. The melting temperature is the temperature at which the glass viscosity becomes 10 2 This is the temperature at which the temperature becomes dPa·s, and will be referred to as T2 below.

[0096] Therefore, an appropriate Al2O3 content is in the range of 1 to 4 mol%. Preferably, the Al2O3 content is 3 mol% or less, and 2 mol% or more.

[0097] (MgO) MgO is an essential component for improving the solubility of glass. To fully achieve this effect, the MgO content in this glass plate 1 is 8 mol% or higher. Furthermore, if the MgO content falls below 8 mol%, the surface compressive stress after chemical strengthening decreases, and the stress layer depth tends to become shallower. On the other hand, if the content is increased beyond the appropriate amount, the strengthening performance obtained by chemical strengthening decreases, and in particular, the depth of the surface compressive stress layer becomes rapidly shallower. While this adverse effect is least pronounced with MgO among alkaline earth metal oxides, the MgO content in this glass plate 1 is 15 mol% or less. Additionally, a high MgO content increases T2 and T4, deteriorates the clarity of the glass melt, and makes it difficult to manufacture high-quality glass plates.

[0098] Therefore, in this glass plate 1, the MgO content is in the range of 8 to 15 mol%, and preferably 12 mol% or less.

[0099] (CaO) CaO has the effect of reducing viscosity at high temperatures, but if the content is too high beyond a moderate range, the glass plate 1 becomes more prone to devitrification, and the movement of sodium ions in the glass plate 1 is inhibited. When CaO is not present, the surface compressive stress after chemical strengthening tends to decrease. On the other hand, when CaO is present in amounts exceeding 8 mol%, the surface compressive stress after chemical strengthening decreases significantly, the depth of the compressive stress layer becomes significantly shallower, and the glass plate 1 becomes more prone to devitrification.

[0100] Therefore, a CaO content in the range of 1 to 8 mol% is appropriate. Preferably, the CaO content is 7 mol% or less, and preferably 3 mol% or more.

[0101] (SrO, BaO) SrO and BaO significantly reduce the viscosity of glass plate 1, and in small amounts, the liquidus temperature T L The effect of reducing the stress is more pronounced than with CaO. However, even with the addition of very small amounts, SrO and BaO significantly hinder the movement of sodium ions in glass plate 1, greatly reducing the surface compressive stress and making the depth of the compressive stress layer considerably shallower.

[0102] Therefore, it is preferable that this glass plate 1 substantially does not contain SrO and BaO.

[0103] (RO) In this embodiment, RO represents the sum of MgO and CaO. If the RO content is too low, there will be insufficient components to reduce the viscosity of the glass plate 1, making dissolution difficult. On the other hand, if the RO content is too high, the surface compressive stress will be greatly reduced, and the depth of the compressive stress layer will become considerably shallower, as will the liquidus temperature T L It is showing a tendency to rise sharply.

[0104] Therefore, an RO content in the range of 12 to 17 mol% is appropriate. Preferably, the RO content is 14 mol% or more, and preferably 16 mol% or less.

[0105] Furthermore, when the molar ratio of CaO to RO (CaO / RO) is in the range of 0.1 to 0.4, the liquidus temperature tends to be particularly low. Therefore, a molar ratio of 0.1 to 0.4 is appropriate. Moreover, while lowering this molar ratio can improve the surface compressive stress and the depth of the compressive stress layer, it increases T2 and T4, causing them to deviate significantly from the narrow definition of SL, making it difficult to manufacture glass articles. Therefore, a molar ratio of 0.2 or higher is preferable, and 0.3 or lower is preferable.

[0106] (Na2O) Na2O is a component that increases surface compressive stress and deepens the surface compressive stress layer by substituting sodium ions with potassium ions. However, if the content is increased beyond the appropriate amount, the stress relaxation during the chemical strengthening treatment will outweigh the generation of surface compressive stress due to ion exchange during the chemical strengthening treatment, resulting in a tendency for the surface compressive stress to decrease.

[0107] On the other hand, Na₂O is a component for improving solubility and reducing T₄ and T₂. However, if the content rate of Na₂O is too high, the water resistance of the glass will be significantly reduced. In the glass sheet 1, if the content rate of Na₂O is 12 mol% or more, the effect of reducing T₄ and T₂ can be sufficiently obtained. If it exceeds 16 mol%, the reduction of the surface compressive stress due to stress relaxation becomes remarkable.

[0108] Therefore, in the glass sheet 1 of the present embodiment, the appropriate range of the content rate of Na₂O is 12 to 16 mol%. The content rate of Na₂O is preferably 13 mol% or more, and more preferably 15 mol% or less.

[0109] (K₂O) Similar to Na₂O, K₂O is a component that improves the solubility of the glass. Also, in the range where the content rate of K₂O is low, the ion exchange rate in chemical strengthening increases, and the depth of the surface compressive stress layer becomes deeper. On the other hand, it reduces the liquidus temperature T L of the glass sheet 1. Therefore, it is preferable to contain K₂O at a low content rate.

[0110] On the other hand, compared with Na₂O, K₂O has a smaller effect of reducing T₄ and T₂. However, the inclusion of a large amount of K₂O inhibits the clarification of the glass melt. Also, the surface compressive stress after chemical strengthening decreases as the content rate of K₂O increases. Therefore, the appropriate range of the content rate of K₂O is 0 to 1 mol%.

[0111] (Li₂O) Even if only a small amount of Li₂O is contained, it significantly reduces the depth of the compressive stress layer. Also, when a glass article containing Li₂O is chemically strengthened with a molten salt of potassium nitrate alone, the rate at which the molten salt deteriorates is significantly faster compared to the case of a glass article not containing Li₂O. Specifically, when repeated chemical strengthening treatment is performed with the same molten salt, the surface compressive stress formed on the glass surface decreases in a smaller number of times. Therefore, in the glass sheet 1 of the present embodiment, it may contain 1 mol% or less of Li₂O, but it is preferably substantially free of Li₂O.

[0112] (B2O3) B2O3 is a component that reduces the viscosity of glass plate 1 and improves its solubility. However, if the B2O3 content is too high, glass plate 1 becomes more prone to phase separation, reducing its water resistance. In addition, compounds formed by B2O3 and alkali metal oxides may volatilize and damage the refractory material in the glass melting chamber. Furthermore, the presence of B2O3 reduces the depth of the compressive stress layer in chemical strengthening. Therefore, a B2O3 content of 0.5 mol% or less is appropriate. In the present invention, it is more preferable that glass plate 1 substantially does not contain B2O3.

[0113] (Fe2O3) Normally, Fe is Fe 2+ or Fe 3+ In this state, it exists in the glass and acts as a coloring agent. Fe 3+ Fe is an ingredient that enhances the UV absorption performance of glass. 2+ This component enhances heat absorption performance. When glass plate 1 is used as cover glass for a display, it is desirable that the coloring is not noticeable, so a low Fe content is preferable. However, Fe is often inevitably mixed in due to industrial raw materials. Therefore, the iron oxide content, converted to Fe2O3, is preferably 0.15% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.02% by mass or less, when the entire glass plate 1 is represented as 100% by mass. In particular, the high-transmittance float glass described above can achieve high transmittance because of its low Fe content. For example, with a thickness of 0.55 mm, it is possible to achieve a transmittance of 91% or more and 100% or less for light with a wavelength of 550 nm.

[0114] (TiO2) TiO2 is a component that reduces the viscosity of the glass plate 1 and simultaneously increases the surface compressive stress due to chemical strengthening, but it can cause the glass plate 1 to have a yellowish tint. Therefore, an appropriate TiO2 content is 0 to 0.2 mass%. In addition, it is inevitably mixed in with commonly used industrial raw materials, and may be present in the glass plate 1 at a concentration of about 0.05 mass%. At this level of concentration, it does not cause discoloration of the glass, so it may be included in the glass plate 1 of this embodiment.

[0115] (ZrO2) ZrO2 can sometimes be mixed into the glass plate 1 from the refractory bricks that make up the glass melting furnace, especially when manufacturing glass plates using the float process, and its content is known to be around 0.01% by mass. On the other hand, ZrO2 is a component that improves the water resistance of glass and increases the surface compressive stress due to chemical strengthening. However, a high ZrO2 content can lead to an increase in the working temperature T4 and the liquidus temperature T4. L This can cause a rapid increase in Zr, and in the production of glass plates by the float method, precipitated Zr-containing crystals tend to remain as foreign matter in the manufactured glass. Therefore, a ZrO2 content of 0 to 0.1 mass% is appropriate.

[0116] (SO3) In the float process, sulfates such as sodium hydroxide (Na2SO4) are commonly used as clarifying agents. The sulfates decompose in the molten glass to produce gaseous components, which promote degassing of the molten glass. However, some of the gaseous components dissolve and remain in the glass plate 1 as SO3. In the glass plate 1 of the present invention, the SO3 content is preferably 0 to 0.3% by mass.

[0117] (CeO2) CeO2 is used as a clarifying agent. CeO2 generates O2 gas in the molten glass, thus contributing to degassing. On the other hand, too much CeO2 can cause the glass to turn yellow. Therefore, the CeO2 content is preferably 0 to 0.5% by mass, more preferably 0 to 0.3% by mass, and even more preferably 0 to 0.1% by mass.

[0118] (SnO2) In glass plates formed by the float process, it is known that tin diffuses from the tin bath to the surface that came into contact with the tin bath during molding, and this tin exists as SnO2. Furthermore, SnO2 mixed with the glass raw material contributes to degassing. In the glass plate 1 of the present invention, the SnO2 content is preferably 0 to 0.3% by mass.

[0119] (Other ingredients) The glass plate 1 according to this embodiment is preferably substantially composed of the components listed above. However, the glass plate 1 according to this embodiment may also contain components other than those listed above, preferably in a range where the content of each component is less than 0.1% by mass.

[0120] In addition to the aforementioned SO3 and SnO2, other permissible components include As2O5, Sb2O5, Cl, and F, which are added for the purpose of degassing molten glass. However, it is preferable not to add As2O5, Sb2O5, Cl, and F due to their significant adverse effects on the environment. Other permissible examples include ZnO, P2O5, GeO2, Ga2O3, Y2O3, and La2O3. Other components derived from industrially used raw materials are also permissible as long as they do not exceed 0.1% by mass. Since these components are added as needed or are inevitably mixed in, the glass plate 1 of this embodiment may substantially not contain these components.

[0121] (Density (specific gravity):d) Based on the above composition, in this embodiment, the density of the glass plate 1 is 2.53 g·cm³. -3 Furthermore, 2.51 g·cm -3 In some cases, the following may be 2.50g·cm -3 It can be reduced to the following levels.

[0122] In processes such as the float process, if there is a large difference in density between different glass types, the molten glass with the higher density may accumulate at the bottom of the furnace when switching between glass types, potentially hindering the transition. Currently, the density of soda-lime glass mass-produced using the float process is approximately 2.50 g·cm³. -3 Therefore, considering mass production by the float method, the density of glass plate 1 is close to the above value, specifically 2.45~2.55 g·cm³. -3 Especially 2.47-2.53 g·cm -3 Preferably, 2.47-2.50 g·cm -3 That is even more preferable.

[0123] (Modulus of elasticity: E) Chemical strengthening involving ion exchange can cause warping of the glass substrate. To suppress this warping, it is preferable that the elastic modulus of the glass plate 1 is high. According to the present invention, the elastic modulus (Young's modulus: E) of the glass plate 1 can be increased to 70 GPa or higher, and even to 72 GPa or higher.

[0124] (Thermal expansion coefficient) In particular, for the aforementioned highly transparent float glass, for example, the coefficient of thermal expansion between 50°C and 350°C is 50 × 10⁻⁶. -7 ~100×10 -7 It is possible to achieve a percentage of less than / K%.

[0125] <2-2-5. Orientation of the glass plate> In glass plates manufactured by the float process, the surface that was in contact with the molten metal is referred to as the bottom surface, and the opposite surface is referred to as the top surface. The bottom and top surfaces may be unpolished. Because the bottom surface was in contact with the molten metal, if the molten metal is tin, the concentration of tin oxide contained in the bottom surface will be greater than the concentration of tin oxide contained in the top surface.

[0126] Thus, the bottom surface has a high tin oxide concentration, which has the effect of suppressing the leaching of alkaline components contained in the glass plate. If it is desired to suppress the decrease in durability due to alkaline leaching, the first functional layer 2 described above can be laminated onto the bottom surface. On the other hand, the top surface has a low tin oxide concentration, resulting in a relatively high concentration of OSiO groups on the surface. Therefore, if it is desired to improve adhesion by utilizing the chemical bond between the OH groups of the first functional layer 2 and the surface OSiO groups, the first functional layer 2 can be laminated onto the top surface. Furthermore, if it is desired to avoid the effects of trace metals (tin), the bottom surface can be polished with an abrasive such as cerium oxide, and the first functional layer 2 can be laminated onto the bottom surface, the top surface, or both the bottom and top surfaces. Note that the above points apply not only to the first functional layer 2 but also to the other functional layers described herein.

[0127] <2-2-6. Thickness of glass plate> The thickness of the glass plate 1 is not particularly limited, but is preferably 0.2 mm or more and 10 mm or less, and more preferably 0.5 mm or more and 4 mm or less. If the thickness of the glass plate 1 is less than 0.2 mm, the rigidity may decrease, while if the thickness of the glass plate 1 is greater than 10 mm, the weight may increase. Also, as mentioned above, if the base material 1 is formed from a resin material, it can be made to the same thickness as the glass plate.

[0128] <3. 1st functional layer> The first functional layer 2 can be composed of a film having various functions. For example, a heat-shielding film (heat-reflective film) or an anti-fogging layer (or anti-fogging sheet) can be used. The heat-shielding film is a known film configured to reflect or absorb infrared rays in order to suppress the temperature rise of the imaging device. Such a film can be attached to the first main surface 11 of the substrate 1 with an adhesive, or a film having a heat-shielding function can be laminated onto the first main surface 11 by coating. Further examples of the first functional layer 2 are described below. The anti-fogging layer will be described in detail.

[0129] <3-1. Anti-fogging layer> The anti-fog layer is not particularly limited as long as it provides an anti-fog effect to the base material 1, and known types can be used. Generally, anti-fog layers include hydrophilic types that form a water film on the surface of water vapor, water-absorbing types that absorb water vapor, water-repellent and water-absorbing types that make it difficult for water droplets to condense on the surface, and water-repellent types that repel water droplets that form from water vapor, and any type of anti-fog layer can be applied. Below, as an example, an example of a water-repellent and water-absorbing type anti-fog layer will be described. [Organic-inorganic composite anti-fog layer] The organic-inorganic composite anti-fogging layer is a single-layer or multi-layer film formed on the surface of any of the functional layers. The organic-inorganic composite anti-fogging layer contains at least a water-absorbing resin, water-repellent groups, and a metal oxide component. The anti-fogging layer may further contain other functional components as needed. The water-absorbing resin can be any type of resin that can absorb and retain water. Water-repellent groups can be supplied to the anti-fogging layer from a metal compound having water-repellent groups (water-repellent group-containing metal compound). The metal oxide component can be supplied to the anti-fogging layer from a water-repellent group-containing metal compound, other metal compounds, metal oxide fine particles, etc. The following describes each component.

[0130] (Water absorbent resin) There are no particular restrictions on the water-absorbing resin, and examples include polyethylene glycol, polyether resins, polyurethane resins, starch resins, cellulose resins, acrylic resins, epoxy resins, polyester polyols, hydroxyalkylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetal resin, and polyvinyl acetate. Of these, hydroxyalkylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetal resin, polyvinyl acetate, epoxy resins, and polyurethane resins are preferred, more preferred are polyvinyl acetal resin, epoxy resins, and polyurethane resins, and particularly preferred is polyvinyl acetal resin.

[0131] Polyvinyl acetal resin can be obtained by condensing polyvinyl alcohol with an aldehyde to form an acetal. The acetalization of polyvinyl alcohol can be carried out using known methods such as precipitation using an aqueous medium in the presence of an acid catalyst, or dissolution using a solvent such as alcohol. Acetalization can also be carried out in parallel with the saponification of polyvinyl acetate. The degree of acetalization is preferably 2-40 mol%, more preferably 3-30 mol%, particularly 5-20 mol%, and in some cases 5-15 mol%. For example, the degree of acetalization can be expressed as follows: 13 It can be measured based on 1C nuclear magnetic resonance spectroscopy. Polyvinyl acetal resins with an acetalization degree within the above range are suitable for forming organic-inorganic composite anti-fogging layers with good water absorption and water resistance.

[0132] The average degree of polymerization of polyvinyl alcohol is preferably 200 to 4500, and more preferably 500 to 4500. A high average degree of polymerization is advantageous for forming an organic-inorganic composite anti-fogging layer with good water absorption and water resistance, but if the average degree of polymerization is too high, the viscosity of the solution may become too high, which may hinder film formation. The degree of saponification of polyvinyl alcohol is preferably 75 to 99.8 mol%.

[0133] Examples of aldehydes to be condensed with polyvinyl alcohol include aliphatic aldehydes such as formaldehyde, acetaldehyde, butyraldehyde, hexylcarbaldehyde, octylcarbaldehyde, and decylcarbaldehyde. Other examples include benzaldehyde; 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, and other alkyl-substituted benzaldehydes; chlorobenzaldehyde and other halogen-substituted benzaldehydes; substituted benzaldehydes in which hydrogen atoms are substituted by functional groups other than alkyl groups such as hydroxyl, alkoxy, amino, and cyano groups; and aromatic aldehydes such as naphthaldehyde and anthraldehyde, which are condensed aromatic ring aldehydes. Aromatic aldehydes with strong hydrophobicity are advantageous in forming an organic-inorganic composite anti-fogging layer with a low degree of acetalization and excellent water resistance. The use of aromatic aldehydes is also advantageous in forming highly absorbent films while retaining a large number of hydroxyl groups. It is preferable that the polyvinyl acetal resin contains an acetal structure derived from an aromatic aldehyde, particularly benzaldehyde.

[0134] Examples of epoxy resins include glycidyl ether epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, and cyclic aliphatic epoxy resins. Of these, cyclic aliphatic epoxy resins are preferred.

[0135] Examples of polyurethane resins include those composed of polyisocyanate and polyol. Acrylic polyols and polyoxyalkylene polyols are preferred as polyols.

[0136] As the cellulose resin, surface-modified TAC (triacetylcellulose) may also be used. Examples of modification methods include physical modification and chemical modification. Examples of physical modification methods include active ray irradiation, plasma treatment, and corona discharge treatment. As a chemical modification method, the acyl groups in the TAC structure may be changed to hydroxyl groups to make the surface hydrophilic (see, for example, JP 2017-57370 and JP 2017-57242). Specifically, the acyl groups in the TAC structure can be changed to hydroxyl groups by swelling the TAC with alcohol, saponification with KOH water, heat treatment, and neutralization washing. Through such saponification treatment, a surface-modified TAC with a thickness of 10 to 200 μm and a modified layer thickness of 1 to 6 μm can be obtained. The modified layer of TAC functions as an anti-fogging layer. The anti-reflective layer of the present invention may be formed on the modified layer (anti-fogging layer) of TAC. The thickness of TAC may be evaluated based on the Japanese Industrial Standard (JIS.K7130:1999. Plastics - Films and Sheets - Method for Measuring Thickness). If the modified layer is a saponified layer obtained by saponification, the thickness of the saponified layer may be determined by the following method: A sample taken from the anti-fog film is immersed in dichloromethane for 24 hours. The sample that remains undissolved after this immersion is dried, and the thickness of the dried sample is measured three times. The average of the three measured values ​​is taken as the thickness of the saponified layer (see, for example,

[0039] of JP 2017-57370).

[0137] The organic-inorganic composite anti-fogging layer mainly consists of a water-absorbing resin. In this invention, "main component" means the component with the highest mass content. The water-absorbing resin content of the organic-inorganic composite anti-fogging layer, based on weight, is preferably 50% by mass or more, more preferably 60% by mass or more, particularly preferably 65% ​​by mass or more, and 95% by mass or less, and more preferably 90% by mass or less, from the viewpoint of film hardness, water absorption, and anti-fogging properties.

[0138] (Water-repellent group) To fully obtain the above-mentioned effects of the water-repellent group, it is preferable to use a water-repellent group with high water repellency. Preferred water-repellent groups are at least one selected from (1) a chain or cyclic alkyl group having 3 to 30 carbon atoms, and (2) a chain or cyclic alkyl group having 1 to 30 carbon atoms in which at least some of the hydrogen atoms are substituted with fluorine atoms (hereinafter sometimes referred to as "fluorine-substituted alkyl group").

[0139] Regarding (1) and (2), the linear or cyclic alkyl group is preferably a linear alkyl group. The linear alkyl group may be a branched alkyl group, but a linear alkyl group is preferred. Alkyl groups with more than 30 carbon atoms may cause the anti-fogging layer to become cloudy. From the viewpoint of balancing the anti-fogging properties, strength, and appearance of the film, the number of carbon atoms in the alkyl group is preferably 20 or less, and more preferably 6 to 14. Particularly preferred alkyl groups are linear alkyl groups with 6 to 14 carbon atoms, especially 6 to 12 carbon atoms, such as n-hexyl group (6 carbon atoms), n-decyl group (10 carbon atoms), and n-dodecyl group (12 carbon atoms). Regarding (2), the fluorine-substituted alkyl group may be a group in which only some of the hydrogen atoms of a linear or cyclic alkyl group are substituted with fluorine atoms, or it may be a group in which all of the hydrogen atoms of a linear or cyclic alkyl group are substituted with fluorine atoms, such as a linear perfluoroalkyl group. Because fluorine-substituted alkyl groups have high water repellency, a sufficient effect can be obtained by adding a small amount. However, if the fluorine-substituted alkyl group is present in excessively high concentrations, it may separate from other components in the coating solution used to form the film.

[0140] (Hydrolyzable metal compounds with water-repellent groups) In order to incorporate water-repellent groups into the anti-fogging layer, it is preferable to add a metal compound having water-repellent groups (water-repellent group-containing metal compound), particularly a metal compound having water-repellent groups and hydrolyzable functional groups or halogen atoms (water-repellent group-containing hydrolyzable metal compound), or its hydrolysate, to the coating solution for forming the film. In other words, the water-repellent groups may be derived from the water-repellent group-containing hydrolyzable metal compound. As the water-repellent group-containing hydrolyzable metal compound, the water-repellent group-containing hydrolyzable silicon compound shown in the following formula (I) is preferred. R m SiY 4-m (I) Here, R is a water-repellent group, i.e., a chain or cyclic alkyl group having 1 to 30 carbon atoms in which at least some of the hydrogen atoms may be substituted with fluorine atoms; Y is a hydrolyzable functional group or halogen atom; and m is an integer from 1 to 3. The hydrolyzable functional group is, for example, at least one selected from alkoxy groups, acetoxy groups, alkenyloxy groups, and amino groups, preferably an alkoxy group, particularly an alkoxy group having 1 to 4 carbon atoms. An alkenyloxy group is, for example, an isopropenoxy group. The halogen atom is preferably chlorine. The functional groups exemplified here can also be used as "hydrolyzable functional groups" as described later. m is preferably 1 to 2.

[0141] When the compound represented by formula (I) undergoes complete hydrolysis and polycondensation, it yields the component represented by the following formula (II). R m SiO (4-m) / 2 (II) Here, R and m are as described above. After hydrolysis and polycondensation, the compound represented by formula (II) actually forms a network structure in the anti-fogging layer in which silicon atoms are bonded to each other via oxygen atoms.

[0142] Thus, the compound represented by formula (I) undergoes hydrolysis or partial hydrolysis, and at least a portion of it undergoes polycondensation to form a network structure of siloxane bonds (Si-O-Si) in which silicon atoms and oxygen atoms are alternately linked and spread three-dimensionally. Hydrophobic groups R are attached to the silicon atoms included in this network structure. In other words, the hydrophobic groups R are fixed to the siloxane bond network structure via R-Si bonds. This structure is advantageous for uniformly dispersing the hydrophobic groups R in the film. The network structure may also contain silica components supplied from silicon compounds other than the hydrophobic silicon compound containing hydrolyzable silicon compounds represented by formula (I) (e.g., tetraalkoxysilane, silane coupling agent). When a silicon compound that does not have hydrophobic groups but has hydrolyzable functional groups or halogen atoms (hydrophobic silicon compound without hydrophobic groups) is blended with a hydrophobic silicon compound containing hydrolyzable silicon compounds to form an anti-fogging layer, a network structure of siloxane bonds containing silicon atoms bonded to hydrophobic groups and silicon atoms not bonded to hydrophobic groups can be formed. With this structure, it becomes easy to independently adjust the content of water-repellent groups and metal oxide components in the anti-fogging layer.

[0143] Water-repellent groups improve anti-fogging performance by increasing the permeability of water vapor on the surface of the anti-fogging layer containing water-absorbing resin. Since water absorption and water repellency are mutually exclusive functions, water-absorbing and water-repellent materials have traditionally been applied to separate layers. However, water-repellent groups eliminate the uneven distribution of water near the surface of the anti-fogging layer, extending the time until condensation occurs and improving the anti-fogging properties of single-layer anti-fogging layers. The following explains this effect.

[0144] Water vapor that penetrates the anti-fogging layer containing water-absorbent resin forms hydrogen bonds with the hydroxyl groups of the water-absorbent resin, etc., and is retained in the form of bound water. As the amount increases, the water vapor progresses from bound water to semi-bound water, and finally to free water held in the voids within the anti-fogging layer. In the anti-fogging layer, water-repellent groups hinder the formation of hydrogen bonds and facilitate the dissociation of formed hydrogen bonds. If the water-absorbent resin content is the same, there is no difference in the number of hydrogen-bonding hydroxyl groups in the film, but water-repellent groups reduce the rate of hydrogen bond formation. Therefore, containing water-repellent groups In the anti-fogging layer, moisture is ultimately retained in the film in one of the above forms, but before being retained, it can diffuse as water vapor to the bottom of the film. Furthermore, once retained, water dissociates relatively easily and moves to the bottom of the film as water vapor. As a result, the distribution of moisture retention in the thickness direction of the film is relatively uniform from near the surface to the bottom of the film. In other words, the entire thickness direction of the anti-fogging layer can be effectively utilized to absorb water supplied to the film surface, making it difficult for water droplets to condense on the surface and resulting in high anti-fogging performance. In addition, because water droplets are less likely to condense on the surface, the anti-fogging layer that has absorbed moisture has the characteristic of being less likely to freeze even at low temperatures.

[0145] On the other hand, in anti-fogging layers that do not contain water-repellent groups, water vapor that penetrates the film is very easily retained in the form of bound water, semi-bound water, or free water. Therefore, the penetrated water vapor tends to be retained near the surface of the film. As a result, the amount of moisture in the film is extremely high near the surface and decreases rapidly as you move towards the bottom of the film. In other words, even though the bottom of the film can still absorb water, the moisture near the surface of the film becomes saturated and condenses into water droplets, resulting in limited anti-fogging properties.

[0146] When water-repellent groups are introduced into the anti-fogging layer using a hydrolyzable silicon compound containing water-repellent groups (see formula (I)), a strong siloxane bond (Si-O-Si) network structure is formed. The formation of this network structure is advantageous not only in terms of abrasion resistance but also in terms of improving hardness, water resistance, and other properties.

[0147] The water-repellent group should be added in such an amount that the water contact angle on the surface of the anti-fogging layer is 70 degrees or more, preferably 80 degrees or more, and more preferably 90 degrees or more. The water contact angle should be measured by dropping 4 mg of water droplets onto the surface of the film. In particular, when using methyl or ethyl groups, which have somewhat weak water repellency, as the water-repellent group, it is preferable to incorporate an amount of the water-repellent group into the anti-fogging layer such that the water contact angle falls within the above range. There is no particular upper limit to this water droplet contact angle, but for example, it should be 150 degrees or less, 120 degrees or less, or even 100 degrees or less. It is preferable to uniformly include the water-repellent group in the anti-fogging layer so that the water contact angle falls within the above range across all areas of the surface of the anti-fogging layer.

[0148] Furthermore, the surface of the anti-fog layer can also be made water-repellent. This suppresses the penetration of alkaline components into the anti-fog layer and protects the surface of the glass plate 1 from alkaline components.

[0149] The anti-fogging layer preferably contains water-repellent groups in an amount of 0.05 parts by mass or more, preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and 10 parts by mass or less, preferably 5 parts by mass or less, per 100 parts by mass of the water-absorbing resin.

[0150] (Inorganic oxides) The inorganic oxide is, for example, an oxide of at least one element selected from Si, Ti, Zr, Ta, Nb, Nd, La, Ce, and Sn, and includes at least an oxide of Si (silica). The organic-inorganic composite anti-fogging layer preferably contains inorganic oxide in an amount of 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, even more preferably 0.2 parts by weight or more, particularly preferably 1 part by weight or more, most preferably 5 parts by weight or more, possibly 10 parts by weight or more, and if necessary 20 parts by weight or more, also preferably 50 parts by weight or less, more preferably 45 parts by weight or less, even more preferably 40 parts by weight or less, particularly preferably 35 parts by weight or less, most preferably 33 parts by weight or less, and possibly 30 parts by weight or less, per 100 parts by weight of the water-absorbing resin. The inorganic oxide is a necessary component to ensure the strength, especially the abrasion resistance, of the organic-inorganic composite anti-fogging layer, but if its content is high, the anti-fogging properties of the organic-inorganic composite anti-fogging layer will decrease.

[0151] (Inorganic oxide fine particles) The organic-inorganic composite anti-fogging layer may further contain inorganic oxide fine particles as at least a portion of the inorganic oxide. The inorganic oxide constituting the inorganic oxide fine particles is, for example, an oxide of at least one element selected from Si, Ti, Zr, Ta, Nb, Nd, La, Ce, and Sn, and is preferably silica fine particles. Silica fine particles can be introduced into the organic-inorganic composite anti-fogging layer by adding colloidal silica, for example. Inorganic oxide fine particles have excellent ability to transmit stress applied to the organic-inorganic composite anti-fogging layer to the article supporting the organic-inorganic composite anti-fogging layer, and also have high hardness. Therefore, the addition of inorganic oxide fine particles is advantageous from the viewpoint of improving the wear resistance of the organic-inorganic composite anti-fogging layer. Furthermore, when inorganic oxide fine particles are added to the organic-inorganic composite anti-fogging layer, fine voids are formed in the areas where the fine particles are in contact with or close to the layer, and water vapor is more easily taken into the film through these voids. For this reason, the addition of inorganic oxide fine particles may also have an advantageous effect on improving anti-fogging properties. Inorganic oxide fine particles can be supplied to the organic-inorganic composite anti-fogging layer by adding pre-formed inorganic oxide fine particles to a coating solution for forming the organic-inorganic composite anti-fogging layer.

[0152] If the average particle size of inorganic oxide fine particles is too large, the organic-inorganic composite anti-fogging layer may become cloudy, and if it is too small, it will aggregate and become difficult to disperse uniformly. From this viewpoint, the average particle size of inorganic oxide fine particles is preferably 1 to 20 nm, more preferably 5 to 20 nm. Here, the average particle size of inorganic oxide fine particles is described in terms of the primary particle state. Furthermore, the average particle size of inorganic oxide fine particles is determined by measuring the particle size of 50 arbitrarily selected fine particles by observation using a scanning electron microscope and adopting the average value. If the content of inorganic oxide fine particles is too high, the water absorption capacity of the entire organic-inorganic composite anti-fogging layer will decrease, and the organic-inorganic composite anti-fogging layer may become cloudy. The inorganic oxide fine particles should preferably be added in an amount of 0 to 50 parts by weight, more preferably 2 to 30 parts by weight, even more preferably 5 to 25 parts by weight, and particularly preferably 10 to 20 parts by weight, per 100 parts by weight of the water-absorbing resin.

[0153] (Hydrolyzable metal compounds that do not have water-repellent groups) The anti-fogging layer may contain a metal oxide component derived from a hydrolyzable metal compound that does not have a water-repellent group (hydrolyzable compound without a water-repellent group). A preferred hydrolyzable metal compound without a water-repellent group is a hydrolyzable silicon compound that does not have a water-repellent group. A hydrolyzable silicon compound without a water-repellent group is, for example, at least one silicon compound selected from silicon alkoxides, chlorosilanes, acetoxysilanes, alkenyloxysilanes, and aminosilanes (provided that it does not have a water-repellent group), with silicon alkoxides without a water-repellent group being preferred. Isopropenoxysilane can be used as an example of an alkenyloxysilane.

[0154] Hydrolyzable silicon compounds that do not have a water-repellent group may be compounds shown in the following formula (III). SiY4(III) As described above, Y is a hydrolyzable functional group, preferably at least one selected from an alkoxy group, an acetoxy group, an alkenyloxy group, an amino group, and a halogen atom.

[0155] Hydrolyzable metal compounds that do not contain water-repellent groups undergo hydrolysis or partial hydrolysis, and at least a portion of them undergo polycondensation to supply a metal oxide component in which metal atoms and oxygen atoms are bonded. This component firmly bonds the metal oxide fine particles to the water-absorbing resin and can contribute to improving the abrasion resistance, hardness, water resistance, etc. of the anti-fogging layer. The amount of metal oxide component derived from hydrolyzable metal compounds that do not have water-repellent groups is preferably in the range of 0 to 40 parts by mass, preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, particularly preferably 3 to 10 parts by mass, and possibly 4 to 12 parts by mass, per 100 parts by mass of the water-absorbing resin.

[0156] A preferred example of a hydrolyzable silicon compound that does not have a water-repellent group is a tetraalkoxysilane, more specifically a tetraalkoxysilane having an alkoxy group with 1 to 4 carbon atoms. A tetraalkoxysilane is, for example, at least one selected from tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxysilane.

[0157] If the content of the metal oxide (silica) component derived from tetraalkoxysilane is excessive, the anti-fogging properties of the anti-fogging layer may decrease. This is partly because the flexibility of the anti-fogging layer decreases, limiting the swelling and shrinkage of the film due to moisture absorption and release. The metal oxide component derived from tetraalkoxysilane should be added in an amount of 0 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 3 to 10 parts by mass, per 100 parts by mass of the water-absorbing resin.

[0158] Another preferred example of a hydrolyzable silicon compound that does not have a water-repellent group is a silane coupling agent. A silane coupling agent is a silicon compound having different reactive functional groups. Preferably, some of the reactive functional groups are hydrolyzable functional groups. A silane coupling agent is, for example, a silicon compound having an epoxy group and / or an amino group and a hydrolyzable functional group. Examples of preferred silane coupling agents include glycidyloxyalkyltrialkoxysilanes and aminoalkyltrialkoxysilanes. In these silane coupling agents, it is preferable that the alkylene group directly bonded to the silicon atom has 1 to 3 carbon atoms. Although glycidyloxyalkyl groups and aminoalkyl groups contain an alkylene group, they are not water-repellent overall because they contain a hydrophilic functional group (epoxy group, amino group).

[0159] Silane coupling agents can firmly bond organic components such as water-absorbing resins with inorganic components such as metal oxide fine particles, contributing to improvements in the abrasion resistance, hardness, and water resistance of the anti-fogging layer. However, if the content of metal oxide (silica) components derived from the silane coupling agent is excessive, the anti-fogging properties of the anti-fogging layer will decrease, and in some cases, the anti-fogging layer may become cloudy. The metal oxide components derived from the silane coupling agent should be added in an amount of 0 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass, per 100 parts by mass of water-absorbing resin.

[0160] (Crosslinked structure) The anti-fogging layer may contain a crosslinked structure derived from a crosslinking agent, preferably at least one crosslinking agent selected from organoboron compounds, organotitanium compounds, and organozirconium compounds. The introduction of the crosslinked structure improves the abrasion resistance, scratch resistance, and water resistance of the anti-fogging layer. From another perspective, the introduction of the crosslinked structure facilitates the improvement of the durability of the anti-fogging layer without reducing its anti-fogging performance.

[0161] When a crosslinking structure derived from a crosslinking agent is introduced into an anti-fogging layer whose metal oxide component is silica, the anti-fogging layer may contain, along with silicon, other metal atoms, preferably boron, titanium, or zirconium.

[0162] The type of crosslinking agent is not particularly limited, as long as it can crosslink the absorbent resin used. Here, only organotitanium compounds are given as examples. Organotitanium compounds are, for example, at least one selected from titanium alkoxides, titanium chelates, and titanium acylates. Examples of titanium alkoxides are titanium tetraisopropoxide, titanium tetra-n-butoxide, and titanium tetraoctoxide. Examples of titanium chelates are titanium acetylacetonate, titanium acetate acetate, titanium octylene glycol, titanium triethanolamine, and titanium lactate. Titanium lactate This may be an ammonium salt (titanium lactate ammonium). The titanium acylate is, for example, titanium stearate. Preferred organotitanium compounds are titanium chelate compounds, particularly titanium lactate.

[0163] When the water-absorbent resin is polyvinyl acetal, the preferred crosslinking agent is an organotitanium compound, particularly titanium lactate.

[0164] (Other optional components) Other additives may be incorporated into the anti-fogging layer. Examples of additives include glycols such as glycerin and ethylene glycol, which have the function of improving anti-fogging properties. Other additives may include surfactants, leveling agents, UV absorbers, colorants, defoamers, and preservatives.

[0165] (base layer) The anti-fogging layer can be directly laminated onto each functional layer 3 and 4, or a base layer can be formed on each functional layer 3 and 4, and the anti-fogging layer can be laminated on top of that. By laminating the anti-fogging layer onto each functional layer 3 and 4 via a base layer in this way, the anti-fogging layer can be made less likely to peel off. For example, a silane coupling agent can be used for the base layer.

[0166] [Thickness] The thickness of the organic-inorganic composite anti-fog layer can be adjusted as appropriate according to the required anti-fog properties and other factors. The thickness of the organic-inorganic composite anti-fog layer is preferably 1 to 20 μm, more preferably 2 to 15 μm, even more preferably 2 to 12 μm, and particularly preferably 3 to 10 μm. A sufficient anti-fog effect can be obtained if the thickness of the anti-fog layer is 1 μm or more. On the other hand, if the anti-fog layer is too thick, the reflected image may be distorted due to uneven film thickness. Also, since the anti-fog layer is formed from a resin material as described above and has a birefringence, if it is too thick, the image may become blurred.

[0167] <3-2. Method for forming an anti-fogging layer> The method for forming the anti-fogging layer having the above-described composition is not particularly limited, but for example, it can be formed by the following method.

[0168] First, prepare the coating liquid (anti-fogging layer solution) for the organic-inorganic composite anti-fogging layer as described above. Next, apply the coating liquid to the substrate 1 using a coating machine, and then dry it in the first heating furnace.

[0169] When applying the coating solution, it is preferable to maintain the relative humidity of the atmosphere at less than 60%, and even less than 40%. Maintaining low relative humidity prevents the organic-inorganic composite anti-fogging layer from excessively absorbing moisture from the atmosphere. If a large amount of moisture is absorbed from the atmosphere, the water that remains in the matrix of the organic-inorganic composite anti-fogging layer may reduce the strength of the film.

[0170] In the first heating furnace, it is preferable to heat at a temperature of 200°C or lower, for example, 50 to 150°C. The heating time is preferably 1 to 20 minutes, and more preferably 2 to 10 minutes. This heating can also be performed multiple times. For example, heating for 3 to 5 minutes can be performed two or more times. In this way, the coating liquid is fired, and a cross-linked structure of water-absorbing resin and Si is formed. However, this is not a strong cross-linked structure formed by completely firing the coating liquid, but rather a provisionally formed anti-fogging layer.

[0171] Next, the substrate dried as described above is immersed in a water tank. This causes the anti-fogging layer on the substrate 1 to swell, and some of the crosslinking points are broken. In addition, impurities contained in the water-absorbing resin, such as Na and Cl, are removed. Furthermore, uncrosslinked water-absorbing resin compositions are also removed. The water stored in the water tank can be, for example, 10 to 80°C, more preferably 20 to 60°C, and particularly preferably 25 to 50°C. The water temperature may be below 10°C, but if it is lower than 10°C, the effect of removing alkaline components may be reduced. On the other hand, if it is higher than 80°C, a large amount of water vapor will evaporate from the water tank, which may increase the load on the equipment and working environment. From the above viewpoint, in order to maintain a relatively high effect in removing alkaline components while reducing the load on the equipment and environment, the water temperature is particularly preferably 25 to 50°C. The immersion time in the water tank can be, for example, 1 to 30 minutes, more preferably 3 to 20 minutes, and particularly preferably 3 to 10 minutes. Even when the water temperature is low and the efficiency of removing alkaline components is low, as described above, the alkaline components can be removed to a sufficient extent by increasing the immersion time. However, since a longer immersion time reduces production efficiency, it is particularly preferable to immerse the water for 3 to 10 minutes. Therefore, for example, the water can be immersed in water at 25 to 50°C for about 3 to 10 minutes. Furthermore, this water treatment can be performed multiple times. In this way, by performing the water treatment multiple times, the effects described later can be obtained even with a small tank without increasing the size of the tank.

[0172] Next, the substrate 1 is heated in a second heating furnace. In this second heating furnace, the swollen anti-fogging layer is fired, and the cross-linked structure of the remaining water-absorbing resin and Si within the anti-fogging layer is strengthened. The heating temperature in this furnace is preferably 200°C or lower, for example, 50 to 150°C, similar to the first heating furnace described above. The heating time is also longer than in the first heating furnace, preferably 3 to 60 minutes, and more preferably 5 to 30 minutes. In this way, the anti-fogging layer is sufficiently fired, and the anti-fogging layer is completed.

[0173] <3-3. Anti-fogging layer with a hydrophilic layer> The anti-fogging layer described above primarily has a moisture-absorbing function, but a hydrophilic layer can be further formed on top of this anti-fogging layer (moisture-absorbing layer). This will be explained in detail below.

[0174] This hydrophilic layer can have various configurations, but for example, it can contain a polyether-modified dimethylsiloxane represented by the following formula (A). [ka] However, m, n, x, and y are independent integers greater than or equal to 1. R 1 is a hydrogen atom or a methyl group, R 2 These are alkyl groups with 1 to 3 carbon atoms.

[0175] Furthermore, the above formula (A) can be further constructed as follows. (1) The average molecular weight of polyether-modified dimethylsiloxane can be set to 3,000 to 300,000. (2) m can be an integer of 2 or 3. In other words, the connection between the silicone main chain and its side chains and the polyether side chains is an ethylene group or a propylene group. Modified dimethylsiloxane can be obtained by adding dimethylpolysiloxane, in which some of the methyl groups in the dimethylpolysiloxane main chain are replaced with hydrogen atoms, to a polyether having vinyl groups at its terminals. (3) The degree of polymerization n of the polyether side chain can be an integer between 3 and 600. In other words, the molecular weight of polyethylene glycol will be approximately 200 to 20000 (degree of polymerization approximately 4 to 400). (4) The denaturation rate, y / (x+y), can be between 0.01 and less than 1. In other words, one or more out of 100 siloxane units are denatured, and it is also possible for all of them (excluding the ends) to be denatured.

[0176] The above-described method for forming the hydrophilic layer can be appropriately adapted from conventionally known methods. For example, polyether-modified dimethylsiloxane may be used as is, or diluted with a solvent capable of dissolving it, soaked into a cotton cloth, and then applied to the anti-fogging layer by rubbing with the cloth. Alternatively, the diluted solution may be applied to the anti-fogging layer using a spray coat, flow coat, etc., and the solvent may be evaporated and dried.

[0177] By forming such a hydrophilic layer, the following effects can be obtained. For example, when the hygroscopic anti-fog layer absorbs moisture and becomes saturated, water vapor adheres to the hydrophilic layer, but due to its hydrophilic function, a water film is formed on the surface of the hydrophilic layer. Therefore, even though a water film is formed after the anti-fog layer becomes saturated, it is possible to suppress fogging caused by water droplets.

[0178] <3-4. Anti-fogging layer with hydrophilic properties> Next, we will describe the anti-fogging layer with hydrophilic properties. While the anti-fogging layer described in section 3-3 above has a separate hydrophilic layer, the anti-fogging layer described in this section incorporates hydrophilic properties and is formed as a single layer.

[0179] This anti-fogging layer has a hydrophilic agent dispersed within the anti-fogging layer that has the aforementioned moisture-absorbing function. This improves the hydrophilicity of the surface of the anti-fogging layer. In other words, even if the water-absorbing resin mentioned above becomes saturated with water, a water film can be formed on the surface of the anti-fogging layer to maintain its anti-fogging properties. Furthermore, if a hydrophilic layer is formed separately on top of the anti-fogging layer as described above, the apparent refractive index of the hydrophilic layer will be higher than that of the anti-fogging layer, which may cause glare. On the other hand, if a hydrophilic agent is dispersed within the anti-fogging layer, glare can be suppressed. Moreover, if a hydrophilic agent is dispersed within the anti-fogging layer, even if the hydrophilic agent on the surface is removed by factors such as wiping, the hydrophilic performance can be maintained by the hydrophilic agent inside appearing on the surface. The hydrophilic agent is not particularly limited, but for example, anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants can all be used. As an anionic surfactant, for example, sodium dialkyl sulfosuccinate can be used.

[0180] The anti-fogging layer can contain a high-boiling-point solvent, for example, a solvent with a boiling point between 100°C and 300°C. This allows the solvent to be dispersed within the anti-fogging layer even if the layer is fired at a temperature above 100°C during formation. Since the hydrophilic agent dissolves in this solvent, it can be dispersed within the anti-fogging layer. However, resins containing organic materials generally have a heat resistance temperature of 300°C or less because they yellow and decompose with heat. Therefore, if a solvent with a boiling point higher than 300°C is used, firing at a temperature below 300°C may result in too much solvent remaining in the anti-fogging layer. For this reason, it is preferable that the boiling point of the solvent used here is 300°C or less. Such a solvent preferably has an alcohol group, which facilitates the dispersion of the hydrophilic agent in the solvent. Specifically, for example, propylene glycol, polyethylene glycol, triethylene glycol, or glycerin can be used.

[0181] The anti-fogging layer described above can be formed, for example, as follows. First, the above-mentioned solvent and hydrophilic agent are added to the above-mentioned coating liquid for the organic-inorganic composite anti-fogging layer to produce an anti-fogging layer solution. Then, this anti-fogging layer solution is applied to the substrate 1 by methods such as spin coating, roll coating, or spray coating. Next, after drying by air cooling, firing is performed in a heating furnace. After that, the anti-fogging layer is completed by air cooling at room temperature. Because this anti-fogging layer contains a hydrophilic agent, the anti-fogging layer can be formed by performing the coating process and the firing process once each. Therefore, the manufacturing time can be significantly reduced. The addition ratio of the high-boiling point solvent in the above-mentioned coating liquid is preferably, for example, 0.1 to 40% by mass, and the addition ratio of the hydrophilic agent is preferably, for example, 0.01 to 1.0% by mass.

[0182] <3-5. Anti-fogging layer mainly composed of inorganic compounds> <3-5-1. Composition of the anti-fog layer> Next, we will describe the anti-fogging layer, which is mainly composed of inorganic compounds. This anti-fogging layer exhibits anti-fogging performance by forming a water film on its surface under high humidity conditions due to its uneven surface. In other words, it functions as a so-called hydrophilic anti-fogging layer. Furthermore, the formation of such unevenness can reduce the apparent refractive index, thereby suppressing surface reflection.

[0183] Such anti-fogging layers can contain, for example, inorganic microparticles and inorganic binders. Furthermore, they can also contain photocatalytic microparticles. By including photocatalytic microparticles, hydrocarbons and organic contaminants deposited on the surface of the anti-fogging layer are decomposed, making it easier for a water film to form. For example, if hydrocarbons and organic contaminants accumulate on the surface of the anti-fogging layer, the contact angle increases, and when water droplets adhere, optical distortion may occur. In contrast, by adding photocatalytic particles, the contaminants on the surface are decomposed, thus suppressing the optical distortion caused by water adhesion.

[0184] Inorganic fine particles include, for example, SiO2, ZrO2, CeO2, ZnO, Al2O3, Nb2O5, It can be formed from Y2O3 and MgO. The particle size of the inorganic fine particles is preferably, for example, 1 to 500 nm, and more preferably 5 to 200 nm and 10 to 150 nm. A larger particle size of the inorganic fine particles is undesirable because it increases the haze rate.

[0185] The inorganic binder may contain a metal oxide component derived from a hydrolyzable metal compound. A preferred hydrolyzable metal compound is a hydrolyzable silicon compound that does not have a water-repellent group. A hydrolyzable silicon compound that does not have a water-repellent group is, for example, at least one silicon compound selected from silicon alkoxides, chlorosilanes, acetoxysilanes, alkenyloxysilanes, and aminosilanes (provided that it does not have a water-repellent group), with silicon alkoxides that do not have a water-repellent group being preferred. Isopropenoxysilane can be given as an example of an alkenyloxysilane.

[0186] Hydrolyzable silicon compounds that do not have a water-repellent group may be compounds shown in the following formula (III). SiY4(III) As described above, Y is a hydrolyzable functional group, preferably at least one selected from an alkoxy group, an acetoxy group, an alkenyloxy group, an amino group, and a halogen atom.

[0187] Hydrolyzable metal compounds that do not contain water-repellent groups undergo hydrolysis or partial hydrolysis, and at least a portion of them undergo polycondensation to supply metal oxide components in which metal atoms and oxygen atoms are bonded. This component can firmly bond inorganic fine particles or photocatalytic fine particles to a substrate or substrate film, or to inorganic fine particles and photocatalytic fine particles, and can contribute to improving the abrasion resistance, hardness, water resistance, etc. of the anti-fogging layer.

[0188] A preferred example of a hydrolyzable silicon compound that does not have a water-repellent group is a tetraalkoxysilane, more specifically a tetraalkoxysilane having an alkoxy group with 1 to 4 carbon atoms. A tetraalkoxysilane is, for example, at least one selected from tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxysilane.

[0189] Another preferred example of a hydrolyzable silicon compound that does not have a water-repellent group is a silane coupling agent. A silane coupling agent is a silicon compound having different reactive functional groups. Preferably, some of the reactive functional groups are hydrolyzable functional groups. A silane coupling agent is, for example, a silicon compound having an epoxy group and / or an amino group and a hydrolyzable functional group. Examples of preferred silane coupling agents include glycidyloxyalkyltrialkoxysilanes and aminoalkyltrialkoxysilanes. In these silane coupling agents, it is preferable that the alkylene group directly bonded to the silicon atom has 1 to 3 carbon atoms. Although glycidyloxyalkyl groups and aminoalkyl groups contain an alkylene group, they are not water-repellent overall because they contain a hydrophilic functional group (epoxy group, amino group).

[0190] Photocatalytic nanoparticles can be formed from oxides or oxynitrides mainly composed of titanium, tungsten, or iron, for example. The particle size of the photocatalytic nanoparticles is preferably 1 to 50 nm, and more preferably 2 to 20 nm or 5 to 10 nm.

[0191] The content of inorganic fine particles is preferably, for example, 0% to 60% by mass, more preferably 10% to 50% by mass, even more preferably 20% to 40% by mass, and particularly preferably 20% to 28% by mass. The content of inorganic binder is preferably, for example, 20% to 70% by mass, and more preferably 30% to 50% by mass. Furthermore, the content of photocatalytic fine particles is preferably, for example, 10% to 50% by mass, and even more preferably 20% to 40% by mass. Note that the anti-fogging layer may not contain inorganic fine particles, but may contain inorganic binder and photocatalytic fine particles.

[0192] The thickness of this anti-fogging layer is preferably, for example, 10 to 500 nm, and more preferably 20 to 250 nm or 50 to 200 nm. In particular, the thickness of the anti-fogging layer is preferably twice the particle size of the inorganic fine particles. This is because if the thickness of the anti-fogging layer is more than twice the particle size of the inorganic fine particles, the inorganic fine particles will overlap in the direction of the film thickness, weakening the adhesion between the inorganic fine particles, which may reduce scratch resistance.

[0193] <3-5-2. Optical properties of transparent laminates> The visible light transmittance of the cover member having the anti-fogging layer described above is preferably 85% or higher, and more preferably 88% or higher. In particular, the minimum transmittance in the visible light wavelength range is preferably within 5% of the substrate's transmittance, and more preferably within 2%. On the other hand, the visible light reflectance of the cover member is preferably 10% or less, and more preferably 7% or less. In particular, the maximum reflectance in the visible light wavelength range is preferably within 5% of the substrate's reflectance, and more preferably within 2%. Furthermore, it is preferable that the cover member satisfies the condition 1 ≤ maximum reflectance / minimum reflectance ≤ 1.5 for the reflectance in the visible light wavelength range. The reflection curve affects the color of the transparent laminate. That is, if the reflectance at a certain wavelength is high, the cover member becomes colored, which may not be acceptable depending on the application, but the color can be suppressed by satisfying the above formula. Note that the maximum reflectance / minimum reflectance can be adjusted by changing the film thickness and composition of the anti-fogging layer.

[0194] Furthermore, the haze ratio of this transparent laminate is preferably 1.0 or less, more preferably 0.5 or less, and particularly preferably 0.3 or less. This makes it suitable for use as a cover member for cameras and the like.

[0195] <3-6. Other forms of anti-fogging layers> In the example above, the anti-fog layer was directly laminated onto the base material 1, but an anti-fog sheet can also be attached. The anti-fog sheet comprises a sheet-like transparent base film, the anti-fog layer laminated on one surface of the base film, and a transparent adhesive layer laminated on the other surface of the base film. The anti-fog sheet can then be fixed by fixing the adhesive layer to the first main surface 11 of the base material 1.

[0196] The base film can be formed from a transparent resin sheet, such as polyethylene or polyethylene terephthalate. The thickness of the base film can be, for example, 75 to 100 μm. The adhesive layer can be formed from, for example, an acrylic or silicone adhesive layer.

[0197] Furthermore, it is possible to omit the use of a base film. First, a release film is prepared, and the anti-fog layer and the adhesive layer are laminated on this release film in that order. After that, the adhesive layer is attached to the first main surface 11 of the base material 1, and then the release film is removed, resulting in the adhesive layer and the anti-fog layer being laminated on the base material 1 in that order. Therefore, in this embodiment, a base film is unnecessary, and distortion caused by the base film can be eliminated. Alternatively, a protective film can be attached to the adhesive layer, and when using the product, this protective film can be removed before attaching the adhesive layer to the base material.

[0198] <3-7. Surface Roughness> The surface roughness Ra of the anti-fogging layer can be, for example, 1 to 1000 nm, and more preferably 10 to 1000 nm. By setting the surface roughness Ra to 1 nm or more, an anti-reflective effect can be obtained. In particular, the anti-reflective effect is significant in the visible light band with wavelengths of 400 to 800 nm. However, if the surface roughness Ra is greater than 1000 nm, light scattering may occur, which is undesirable.

[0199] <4.Applications> The cover member described above can be used for various purposes. For example, as shown in Figure 2, it can be used as a cover member 10 to cover the lens 51 of the imaging device 5. In this case, a bracket 6 for attaching to the lens can be appropriately attached to the cover member 10. Then, a closed space is formed in front of the lens by the cover member 10 and the bracket 6. In this case, the first main surface 11 of the base material 1 of the cover member 10 is oriented towards this closed space. Therefore, since the first functional layer 2 is laminated on the first main surface 11, fogging of the first main surface 11 due to temperature or pressure difference between the closed space and the outside can be suppressed. Thus, fogging of the cover member 10 that would interfere with imaging can be prevented.

[0200] Such imaging devices can include, for example, bullet-type and dome-type surveillance cameras, as shown in Figure 3, in which the imaging device 5 is installed inside a housing 7 and is sealed off from the outside air by the housing 7 and cover member 10. In this case, the cover member 10 is positioned in front of the lens of the imaging device 5. In such surveillance cameras, a temperature difference is created across the cover member 10 due to the heat generated from the imaging device 5 and changes in the surrounding environment. Therefore, the cover member 10 is in an environment where condensation and fogging are likely to occur.

[0201] Furthermore, imaging devices mounted on aircraft are prone to condensation due to significant changes in atmospheric pressure in the surrounding environment. For these reasons, the cover member 10 of this embodiment can be suitably used as a cover member for surveillance cameras and devices mounted on aircraft.

[0202] Furthermore, it is not limited to applications in locations with significant environmental changes as described above; for example, it can be used as a cover component for imaging devices mounted on mobile vehicles such as automobiles, or as a cover component for other general imaging devices.

[0203] In particular, the transparent laminate having an anti-fog layer mainly composed of the inorganic compounds described above is suitable for use as a cover member for various cameras, such as surveillance cameras used outdoors, because, as will be described later, it is excellent not only in anti-fog performance but also in peeling resistance, weather resistance, and water resistance of the anti-fog layer. Furthermore, if the anti-fog layer contains photocatalytic fine particles, when irradiated with ultraviolet light, organic contaminants adhering to the surface of the anti-fog layer can be decomposed, and the anti-fog performance can be restored. As such a cover member, the anti-fog layer may be laminated on any surface of the substrate. That is, it may be on either the lens side or the outer side of the camera. When the anti-fog layer is laminated on the lens side of the camera, it is preferable to provide the surveillance camera with an irradiation device that irradiates ultraviolet light toward the anti-fog layer. This allows organic contaminants adhering to the anti-fog layer to be forcibly decomposed when necessary.

[0204] <5. Others> In the example above, the first main surface 11 of the substrate 1 is facing the camera lens side of the imaging device, so the second main surface 12 is exposed to the outside air. Therefore, to prevent water droplets from adhering to the second main surface 12, a water-repellent layer or a hydrophilic layer (third functional layer) can be formed on the second main surface 12, for example. The water-repellent layer and the hydrophilic layer can be formed by coating with a known water-repellent film or hydrophilic film. This is the same in the second embodiment described later.

[0205] [Examples] (1. Anti-fogging layer made of organic-inorganic composite film) The following describes an embodiment of the first embodiment, in which an anti-fogging layer made of an organic-inorganic composite film is provided as the first functional layer. However, the present invention is not limited to the following embodiments.

[0206] As Example 1, the following cover member was fabricated. (1) Substrate: Float glass with a thickness of 1.1 mm was used. (2) First functional layer: The anti-fogging layer shown below was formed on the first main surface of the substrate.

[0207] (i) Preparation of coating liquid for anti-fogging layer A coating solution for forming an anti-fogging layer was prepared by placing a polyvinyl acetal resin-containing solution (Sekisui Chemical Co., Ltd. "Eslec KX-5", 8% solids by mass, 9 mol% degree of acetalization, containing an acetal structure derived from benzaldehyde) 62.5% by mass, n-hexyltrimethoxysilane (HTMS, Shin-Etsu Chemical Co., Ltd. "KBM-3063") 0.37% by mass, tetraethoxysilane (TEOS, Shin-Etsu Chemical Co., Ltd. "KBE-04") 1.04% by mass, alcohol solvent (Nippon Alcohol Industry Co., Ltd. "Solmix AP-7") 20.44% by mass, purified water 15.63% by mass, hydrochloric acid as an acid catalyst 0.01% by mass, and a repelling agent (Shin-Etsu Chemical Co., Ltd. "KP-341") 0.01% by mass in a glass container and stirring at room temperature (25°C) for 3 hours.

[0208] (ii) Film formation process for the anti-fogging layer First, the anti-fogging coating solution prepared as described above was applied to the substrate and passed through a 90°C heating furnace for 5 minutes. Next, the substrate was immersed in 50°C water for 10 minutes and then heated in a 110°C heating furnace for 10 minutes. In this way, the moisture-absorbing layer of the anti-fogging layer was formed.

[0209] Next, polyether-modified dimethylsiloxane (BYK-333, manufactured by BYChemie Japan Co., Ltd.) was diluted to 1 wt% with an alcohol-based solvent (Solmix AP-7, manufactured by Nippon Alcohol Sales Co., Ltd.) to prepare a coating solution. This solution was then applied to the substrate, which was tilted, using the flow-coating method to ensure the entire water-absorbing film was wet, and the substrate was allowed to dry. In this way, a hydrophilic layer was formed. The thickness of the hydrophilic layer was 10 nm.

[0210] (2. Anti-fogging layer mainly composed of inorganic compounds) Next, an example of a cover member having an anti-fogging layer mainly composed of an inorganic compound as the first functional layer will be described.

[0211] A float glass with a thickness of 1.1 mm was prepared as the base material, and an anti-fogging layer having the following composition was formed on one side thereof. The anti-fogging layer was applied by spin coating with an anti-fogging coating solution (rotation speed 3000 rpm), and then fired under the following conditions.

[0212] [Table 1]

[0213] The cover members according to Examples 1 to 11, formed as described above, were subjected to the following tests. (2-1. Anti-fog performance test) A container was filled with water at 80-100°C, and a cover component was placed 5 cm above the water surface, with the anti-fog layer facing the water surface. The following evaluation was then performed. A: A uniform water film is formed on the anti-fogging layer within 3 to 5 seconds. B: A water film forms on the anti-fogging layer within 3-5 seconds, but distortion is observed. C: The anti-fog layer fogs up within 3 seconds.

[0214] Also, after irradiating with ultraviolet rays of 60 mW / cm 2 for 10 minutes, the anti-fogging performance test was conducted again. The results are as follows.

Table 2

[0215] In Examples 4 to 6, since the content of SiO2 fine particles is small, it is considered that the anti-fogging performance is low. However, after irradiating with ultraviolet rays, since the dirt on the surface is decomposed, the same anti-fogging performance as in Examples 1 to 3 and 7 to 11 is obtained, so it is considered that it can sufficiently withstand practical use. Incidentally, the ultraviolet rays of 60 mW / cm 2 are of higher intensity than sunlight, but this was conducted as an accelerated test. Therefore, even with ultraviolet rays of 1 mW / cm 2 equivalent to sunlight, if irradiated for a long time it is considered that Examples 4 to 6 can obtain anti-fogging performance. This is the same in the tests described later.

[0216] (2-2. Abrasion test) As the cloth, Terylene manufactured by Toray Industries, Inc. impregnated with alcohol (A-10 manufactured by FUTABA CHEMICAL CO., LTD.) was prepared. This cloth was pressed against the anti-fogging layer of each example at a load of 300 g, and reciprocated 10 times at a distance of 5 cm. Then, while conducting the above-described anti-fogging performance test, it was visually confirmed whether peeling of the anti-fogging layer occurred. Also, after irradiating with ultraviolet rays of 60 mW / cm 2 for 20 minutes, the anti-fogging performance test was conducted again. The results are as follows.

Table 3

[0217] In Examples 1-3, peeling of the anti-fog layer was confirmed by abrasion testing. This is thought to be due to the high content of SiO2 fine particles. However, as in Examples 7-9, even with a high content of SiO2 fine particles, when fired at high temperatures, a strong anti-fog layer is formed with sufficient crosslinking of SiO2 fine particles, and no peeling is observed. Therefore, for example, even if the anti-fog layer is wiped to remove dirt, it was found that peeling of the anti-fog layer is prevented, especially in Examples 4-11.

[0218] Regarding anti-fogging performance, in Examples 1-6, the firing temperature was low, so organic matter contained in the SiO2 binder remained on the surface of the anti-fogging layer, resulting in a high surface contact angle and thus no anti-fogging performance. On the other hand, in Examples 7-11, the firing temperature was high, so organic matter contained in the SiO2 binder was removed from the surface by thermal decomposition, thus exhibiting anti-fogging properties. Furthermore, in such durability tests, it is thought that the adhesion of hydrocarbons to the surface of the anti-fogging layer and the presence of organic residue from the SiO2 binder on the surface of the anti-fogging layer contaminate the layer, leading to a deterioration of anti-fogging performance.

[0219] (2-3. Weather resistance test) The cover members according to each embodiment were placed in a constant temperature chamber at 80°C and 80% humidity for 48 hours. Afterward, the anti-fogging performance test described above was performed. Furthermore, the following test was conducted at 1 mW / cm². 2 The time it took for the anti-fogging performance of evaluation A to be achieved after irradiating with ultraviolet light was measured. The evaluation regarding this time is as follows: P: Less than 10 hours Q: 10-30 hours R: Longer than 30 hours The results are as follows: [Table 4]

[0220] In the anti-fogging performance test after removing the cover members from the constant temperature chamber, all of Examples 1 to 11 showed low anti-fogging performance (Evaluation C). On the other hand, after irradiation with ultraviolet light, Examples 1 to 3 and 7 to 11 showed high anti-fogging performance, but Examples 4 to 6 remained low. This is thought to be due to the high content of inorganic binder. Furthermore, according to the inventors, although details are not described in Table 4, Examples 1 to 3 showed that the higher the TiO2 fine particle content, the shorter the time it took for anti-fogging performance to appear. In other words, the time it took for anti-fogging performance to appear after ultraviolet irradiation was shorter in Examples 2 and 3 than in Example 1. Therefore, for example, when the present invention is used as a cover member for a surveillance camera, it was found that it generally shows high anti-fogging performance even in high temperature and high humidity outdoor environments if ultraviolet light is irradiated.

[0221] (2-4. Immersion Test) The cover members according to each embodiment were immersed in water (20°C ± 5°C) for 180 hours. Afterward, the anti-fogging performance test described above was performed. The results are as follows. [Table 5]

[0222] The "A, B" ratings in Examples 1-5 indicate that a portion of the anti-fogging layer has an area rated B, but all were found to possess high anti-fogging performance. Therefore, the cover member according to the present invention is considered suitable for outdoor use where it may be exposed to rainwater.

[0223] Based on the test results above, Examples 1 to 11 are all suitable for outdoor use. In particular, Examples 8 to 11 exhibit high anti-fogging performance even in harsh environments.

[0224] (2-5. Transmittance) The transmittance of the cover members and substrates of Examples 1 to 3 was measured in accordance with JIS R3106. The results are shown in Figure 4. As shown in Figure 4, Examples 1 to 3 show a transmittance of approximately 89% or more in the visible light wavelength range (approximately 380 to 780 nm). In particular, considering that the transmittance of the substrate, which is a glass plate, is approximately 91%, Examples 1 to 3 are within 2% of the transmittance of the substrate, indicating that they exhibit high transmittance.

[0225] (2-6. Reflectance) The reflectance of the cover members and substrates of Examples 1 to 3 was measured in accordance with JIS R3106. The results are shown in Figure 5. As shown in Figure 5, in the visible light wavelength range (approximately 380 to 780 nm), Examples 1 to 3 show a reflectance of approximately 6 to 8%. In particular, since the reflectance of the substrate, which is a glass plate, is approximately 8 to 9%, Examples 1 to 3 show a reflectance that is approximately 2% lower than that of the substrate, indicating a low reflectance.

[0226] (3. Anti-fogging layer with hydrophilic properties) Next, we will describe Examples 12 to 20 of cover members in which an anti-fogging layer having the hydrophilic function described above is formed as the first functional layer.

[0227] A float glass substrate with a thickness of 1.1 mm was prepared, and an anti-fogging layer was formed on one side. The anti-fogging layer was applied by spin coating using the anti-fogging coating solution described below, air-cooled for 10 minutes, and then fired in a furnace. The furnace was fired at 100°C for 30 minutes. After that, the anti-fogging layer was formed by air-cooling at room temperature. The thickness of the anti-fogging layer was approximately 10 μm.

[0228] The coating liquid for the anti-fog layer was prepared as follows. A polyvinyl acetal resin-containing solution (ESREC KX-5 manufactured by Sekisui Chemical Co., Ltd., 60.24% by mass (solid content concentration 5.0% by mass)), 20.0% by mass of a high-boiling solvent (shown in Table 6), 0.28% by mass of 3-glycidoxypropyltrimethoxysilane (GPTMS, KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) (solid content concentration 0.2% by mass), 1.04% by mass of tetraethoxysilane (TEOS, KBE-04 manufactured by Shin-Etsu Chemical Co., Ltd.) (solid content concentration 0.30% by mass), 6.32% by mass of an alcohol solvent (Solmix AP-7 manufactured by Nippon Alcohol Industry Co., Ltd.), 11.87% by mass of purified water, 0.10 - 0.40% by mass of a surfactant (Lapizole manufactured by NOF Corporation) (solid content concentration 0.10 - 0.40% by mass, see Table 6), 0.01% by mass of hydrochloric acid as an acid catalyst, 0.01% by mass of a leveling agent (KP-341 manufactured by Shin-Etsu Chemical Co., Ltd.), 0.01% by mass of a leveling agent (KP-112 manufactured by Shin-Etsu Chemical Co., Ltd.), 0.01% by mass of a leveling agent (DOWSIL 8526 Additive manufactured by Dow Chemical Japan Co., Ltd.), 0.0(1% by mass of a leveling agent (BKY-349 manufactured by BYK Chemie Japan Co., Ltd.) were placed in a glass container and stirred at room temperature (25°C) for 3 hours to prepare the coating liquid for the anti-fog layer.

[0229] As the high-boiling solvent, propylene glycol (PG), polyethylene glycol (PEG), and triethylene glycol (TEG) were used. The coating liquids for the anti-fog layer according to Examples 12 - 20 contain the following high-boiling solvents (unit: mass% of the addition ratio).

[0230]

Table 6

[0231] The following tests were conducted on the anti-fog layer formed as described above.

[0232] (3-1 Anti-fog Performance Test) Hot water at 80 to 100 °C was stored in a container, and a cover member was placed with an anti-fog layer facing the water surface at a position 5 cm from the water surface of this hot water. Then, it was inspected whether it became foggy in 10 seconds or more (anti-fog performance), whether a water film was formed within 1 second, and whether there were any problems with the appearance. In the appearance inspection, it was visually inspected whether the surface of the anti-fog layer was smooth and whether there were no distortions or streaks formed. The results are as follows, where OK indicates that there were no problems.

Table 7

[0233] From the above results, it was found that the anti-fog layers according to Examples 12 to 20 exhibited sufficient anti-fog performance.

[0234] (3-2 Abrasion test) As the cloth, Trecie manufactured by Toray Industries, Inc. impregnated with alcohol (A-10 manufactured by Futaba Chemical Co., Ltd.) was prepared. This cloth was pressed against the anti-fog layer of each example with a load of 300 g, and reciprocated 10 times over a distance of 5 cm. Then, the same anti-fog performance test as described in (3-1) above was conducted. The results are as follows.

Table 8

[0235] From the results in Table 8, after wiping, in Examples 15, 16, 18, and 20, distortions were observed on the surface of the anti-fog layer, but in other examples, the anti-fog performance was maintained.

[0236] (3-3. Weather resistance test) The cover member according to each example was placed in a thermostatic chamber at a temperature of 85 °C and a humidity of 85% for 48 hours. Then, the same anti-fog performance test as described in (3-1) above was conducted. The results are as follows.

Table 9

[0237] <B. Second Embodiment> A second embodiment in which the transparent laminate according to the present invention is applied to a cover member will be described below with reference to the drawings. Figure 6 is a cross-sectional view of the cover member according to the second embodiment.

[0238] The cover member 20 according to this embodiment differs from that of the first embodiment in that a second functional layer 3 is further laminated on the first functional layer 2 described above, while the other configurations are as described in the first embodiment. The second functional layer will now be described.

[0239] <1. Overview of the cover component> As shown in Figure 6, the cover member 20 according to this embodiment comprises a base material 1, a first functional layer 2 laminated on the first main surface 11 of the base material 1, and a second functional layer 3 laminated on the first functional layer 2. The base material 1 and the first functional layer 2 are the same as those shown in the first embodiment.

[0240] For the second functional layer 3, for example, an anti-reflective coating, an anti-glare coating, an anti-static coating, an antibacterial coating, etc., can be used. Below, we will describe an example in which an anti-fogging layer is used as the first functional layer 2 and an anti-reflective coating is used as the second functional layer 3.

[0241] The anti-fogging layer of the first functional layer 2 is not one having a hydrophilic layer on the uppermost surface as shown in the first embodiment, but rather a moisture-absorbing layer formed of, for example, an organic-inorganic composite anti-fogging layer. If an anti-reflective layer is laminated on such a moisture-absorbing anti-fogging layer, it may hinder the moisture absorption effect. Therefore, the anti-reflective layer according to this embodiment has voids inside, forming a passage for water vapor to the anti-fogging layer 2. This will be explained in detail below.

[0242] <2.Second functional layer> Figure 7 is a cross-sectional view of the second functional layer. As shown in Figure 6, the second functional layer 3 comprises hollow particles 31 and a binder 32. The hollow particles 31 are made of a material having a refractive index of 1.15 to 2.70. The binder 32 is formed of at least polysilsesquioxane and binds the hollow particles 31. In the second functional layer 3, the absorbances derived from hydrocarbon groups not directly bonded to silicon atoms, absorbances derived from the bonding between silicon atoms and non-reactive functional groups, and absorbances derived from the bonding between silicon atoms and hydroxyl groups, determined by total internal reflection (ATR) measurement using a Fourier transform infrared spectrophotometer, are denoted as Ia, Ib, and Ic, respectively. The second functional layer 3 satisfies at least one of the following conditions: Ib / Ia≧0.7 and Ib / Ic≧0.3. In this specification, Ib / Ia is also referred to as the organic-inorganic parameter (D), and Ib / Ic is also referred to as the hydrophobic parameter (H). Absorbance Ia, absorbance Ib, and absorbance Ic can be determined, for example, from absorption spectra obtained by the ATR method according to the method described in the Examples.

[0243] The organic-inorganic parameter (D) increases as the amount of hydrocarbon groups not directly bonded to silicon atoms in the binder 32 decreases. When the amount of hydrocarbon groups not directly bonded to silicon atoms in the binder 32 decreases, the Si-O-Si network in the binder 32 becomes denser, and the density of inorganic components in the binder 32 increases. As a result, the hollow particles 31 are firmly fixed by the Si-O-Si network. Therefore, if Ib / Ia ≥ 0.7 in the second functional layer 3, the hollow particles 31 are firmly fixed in the second functional layer 3, and the second functional layer 3 has properties advantageous for low refractive index coating. If the fixation of hollow particles in the film is insufficient, the mechanical strength of the film may decrease.

[0244] The hydrophobic parameter (H) increases as the number of hydroxyl groups bonded to silicon atoms in the binder 32 decreases. For example, if hydroxyl groups condense together in the raw materials of the binder 32 to develop a Si-O-Si network, the number of hydroxyl groups bonded to silicon atoms in the binder 32 decreases. If the hydrophobic parameter (H) is above a predetermined value, a dense Si-O-Si network is developed in the binder 32, and this network firmly fixes the hollow particles 31. Therefore, if Ib / Ic ≥ 0.3 in the second functional layer 3, the hollow particles 31 are firmly fixed in the second functional layer 3, and the second functional layer 3 has properties advantageous for low refractive index coating.

[0245] The second functional layer 3 preferably further satisfies the conditions Ib / Ia≧0.7 and Ib / Ic≧0.3. This ensures that the hollow particles 31 are more reliably and firmly fixed in the second functional layer 3, giving the second functional layer 3 properties advantageous for low refractive index coatings.

[0246] When silanol groups (Si-OH) are present in the binder 32, these silanol groups form hydrogen bonds with the silanol groups present on the surface of the glass plate 1, resulting in high affinity. For this reason, films with a hydrophobic parameter (H) below a predetermined value tend to adhere to the glass plate 1. To exhibit good adhesion to both substrates with hydrophilic and hydrophobic surfaces, the second functional layer 3 more preferably satisfies the condition 0.3 ≤ Ib / Ic ≤ 2.0.

[0247] In the second functional layer 3, the first absorbance, second absorbance, and third absorbance, which originate from the bond between one oxygen atom and two silicon atoms as determined by the ATR method, are denoted as Id, Ie, and If, respectively. The first absorbance Id corresponds to the first wavenumber. The second absorbance Ie corresponds to the second wavenumber which is greater than the first wavenumber. The third absorbance If corresponds to the third wavenumber which is greater than the second wavenumber. Preferably, the second functional layer 3 satisfies at least one of the following conditions: Id / Ib ≤ 60, Ie / Ib ≤ 20, and If / Ib ≤ 174. In this specification, Id / Ib is also referred to as the first network parameter (N1), Ie / Ib as the second network parameter (N2), and If / Ib as the third network parameter (N3).

[0248] The first wave frequency is, for example, 455 ± 50 cm. -1 This is the wavenumber at which the absorption spectrum maximum appears. The second wavenumber is, for example, 780 ± 50 cm⁻¹. -1 This is the wavenumber at which the maximum value of the absorption spectrum appears. The third wavenumber is, for example, 1065 ± 50 cm⁻¹. -1 This is the wavenumber at which the maximum value of the absorption spectrum appears.

[0249] The first network parameter (N1), the second network parameter (N2), and the third network parameter (N3) are larger the more oxygen atoms bonded to two silicon atoms (Si-O-Si) in the binder 32. The more the Si-O-Si network formed by the condensation of hydroxyl groups in the raw materials of the binder 32 develops, the larger the first network parameter (N1), the second network parameter (N2), and the third network parameter (N3) become. On the other hand, in order to maintain good film-forming properties, it is important to suppress the aggregation of hollow particles and maintain a uniform thickness of the coating film. To suppress the aggregation of hollow particles, it is desirable to prevent the excessive development of the Si-O-Si network. From this viewpoint, it is desirable that at least one of the following conditions be met in the second functional layer 3: N1 is 60 or less, N2 is 20 or less, and N3 is 174 or less. This allows for the successful formation of the second functional layer 3, and provides an anti-reflective structure with good anti-reflective performance due to the second functional layer 3.

[0250] The second functional layer 3 more preferably satisfies the conditions Id / Ib ≤ 60, Ie / Ib ≤ 20, and If / Ib ≤ 174.

[0251] Typically, the polysilsesquioxane of binder 32 has non-reactive functional groups bonded to silicon atoms. For the polysilsesquioxane of binder 32 to exhibit appropriate hydrophobicity, the non-reactive functional groups are, for example, hydrophobic functional groups such as alkyl groups. Preferably, the polysilsesquioxane of binder 32 is a polysilsesquioxane in which hydrocarbon groups containing 16 or fewer carbon atoms are bonded to silicon atoms as non-reactive functional groups. In this case, since the non-reactive functional groups are not bulky, a dense Si-O-Si network is easily formed.

[0252] The binder 32 may, for example, be further formed of silica. In this case, the polysilsesquioxane contained in the binder 32 readily exhibits hydrophobic properties, and the silica contained in the binder 32 readily exhibits hydrophilic properties. Therefore, by adjusting the ratio (Mp / Ms) of the amount of polysilsesquioxane to the amount of silica in the binder 32, the hydrophilicity or hydrophobicity of the second functional layer 3 can be adjusted to an appropriate level. This allows the second functional layer 3 to be appropriately formed on substrates having a hydrophilic surface, such as a glass substrate, and also on substrates having a hydrophobic surface, such as a resin. From this viewpoint, the ratio (Mp / Ms) of the amount of polysilsesquioxane to the amount of silica in the binder 32 is, for example, 3 / 7 or more, preferably 1 to 9, and more preferably 3 / 2 to 4.

[0253] The hollow particles 31 are not particularly limited as long as they have a hollow structure, but for example, they may have spherical, cylindrical, or sheet-like shapes. The hollow particles 31 have, for example, an average particle diameter (primary particle diameter) of 10 to 150 nm. This makes it easier for the hollow particles 31 to disperse uniformly in the second functional layer 3. The average particle diameter of the hollow particles 31 can be determined, for example, by taking the arithmetic mean of the particle diameters of 50 or more hollow particles 31 observed using a transmission electron microscope (TEM) or scanning electron microscope (SEM). Note that the particle diameter of each particle refers to the maximum diameter.

[0254] The hollow particles 31 preferably have an average particle diameter of 20 to 100 nm, and more preferably 30 to 70 nm. The maximum dimension of the internal space in the hollow particles 31 is, for example, 5 to 100 nm, preferably 10 to 70 nm, and more preferably 20 to 50 nm. The hollow particles 31 are preferably monodisperse particles having a coefficient of variation of 0.1 or less.

[0255] The material of the hollow particles 31 may be an inorganic or organic material, as long as it has a refractive index of 1.15 to 2.70. Preferably, the material of the hollow particles 31 has a refractive index of 1.20 to 2.00, more preferably 1.30 to 1.50, and even more preferably 1.38 to 1.46. From the viewpoint of resistance to deformation under external force, the hollow particles 31 are preferably made of an inorganic material. In this case, the hollow particles 31 are made of at least one selected from the group consisting of silica, magnesium fluoride, alumina, aluminosilicate, titania, and zirconia.

[0256] In particular, in order to provide an anti-reflective structure with high anti-reflective performance through a low refractive index coating using the second functional layer 3, the hollow particles 31 are preferably made of silica or magnesium fluoride. The refractive index of silica is 1.46, and the refractive index of magnesium fluoride is 1.38.

[0257] The structure and material of the hollow particle 31 are determined so that the hollow particle 31 has a desired refractive index. For example, the material of the hollow particle 31 and the ratio of the internal space to the total volume of the hollow particle 31 are determined so that the hollow particle 31 has a desired refractive index. The hollow particle 31 has a refractive index of, for example, 1.10 to 1.40, preferably 1.20 to 1.35, and more preferably 1.25 to 1.30. For example, in multiple types of hollow particles made of materials with different refractive indices, if the ratio of the internal space to the total volume of the hollow particle is the same, the hollow particle made of the low refractive index material will have a lower refractive index than the hollow particle made of the high refractive index material.

[0258] The refractive index of the hollow particles 31 can be measured, for example, by the immersion method (Becke line method). For example, if the hollow particles 31 are made of silica, the refractive index of the hollow particles 31 can be measured by following the procedure below: (i) Evaporate and dry the dispersion medium of the dispersion of hollow particles 31 to obtain a powder. (ii) Mix the powder obtained in (i) with various standard refractive index solutions having different refractive indices, such as Series A and Series AA manufactured by GARGILL. (iii) Determine the refractive index of the standard refractive index solution used when the mixture obtained in (ii) becomes transparent as the refractive index of the hollow particles 31.

[0259] The hollow particles 31 may be commercially available or manufactured by a predetermined method. For example, the hollow particles 31 may be manufactured by forming a shell around a core and then removing the core. For example, a shell made of silica or a shell made of magnesium fluoride may be formed around a polymer core having a particle diameter of several tens of nanometers. The polymer core is then removed by dissolving in a solvent or by combustion to obtain hollow particles 31, which are hollow silica particles or hollow magnesium fluoride particles. Alternatively, a shell made of magnesium fluoride may be formed around a silica core, and the silica core may be dissolved in an alkali. By dissolving the material, hollow magnesium fluoride particles, or hollow particles 31, can be obtained.

[0260] In the second functional layer 3, the ratio of the mass Wh of the hollow particles 31 to the mass Wb of the binder 32 (Wh / Wb) is, for example, 1 / 5 to 20, preferably 1 / 3 to 10, and more preferably 1 to 5. This makes it possible to provide an anti-reflective structure with high anti-reflective performance by using a low refractive index coating with the second functional layer 3.

[0261] The thickness of the second functional layer 3 is not particularly limited, but is determined, for example, according to the wavelength of light whose reflection should be prevented. Specifically, the thickness of the second functional layer 3 is set so that the optical film thickness (refractive index × physical film thickness) satisfies λ / 4, where λ (nm) is the wavelength of the center of the wavelength of light whose reflection should be prevented. For example, to prevent reflection of light belonging to the visible light region (practically wavelengths of 380 nm to 780 nm), if the center wavelength λ is set to λ = 550 nm and the refractive index of the low refractive index film used is 1.20, the optimal physical film thickness is 115 nm. The practically effective thickness of the second functional layer 3 for preventing reflection of visible light is 50 to 300 nm, preferably 70 to 200 nm, and more preferably 90 to 170 nm. This makes it possible to provide an anti-reflective structure with high anti-reflective performance by using a low refractive index coating with the second functional layer 3. Furthermore, to prevent reflection of light with a central wavelength of λ=850nm, which is close to the visible light region within the near-infrared region (e.g., wavelengths of 800nm ​​to 2500nm), the optimal physical film thickness is 177nm when the refractive index of the low-refractive-index film used is 1.20. The practically effective thickness of the second functional layer 3 for preventing near-infrared reflection is 80 to 350nm, preferably 130 to 250nm, and more preferably 150 to 220nm. This makes it possible to provide an anti-reflective structure with high anti-reflective performance by using a low-refractive-index coating with the second functional layer 3. When a multilayer film is used as the anti-reflective structure, a low-refractive-index layer with a film thickness of 50nm or less may be used. The physical film thickness of the low-refractive-index film is not limited to these, but its cross-section can be measured by SEM, TEM, or ellipsometer.

[0262] The second functional layer 3 has a refractive index of, for example, 1.45 or less, preferably 1.1 to 1.35. This makes it possible to provide an anti-reflective structure with high anti-reflective performance by using a low refractive index coating with the second functional layer 3. Preferably, the second functional layer 3 has a refractive index of 1.30 or less, and more preferably 1.25 or less. From the viewpoint of reducing the refractive index of the second functional layer 3, the second functional layer 3 may include an air layer (air space) in the space between the hollow particles 31 or in the binder 32. The refractive index of the second functional layer 3 can be determined, for example, by reflectance spectroscopy. By increasing the proportion of this air layer (void ratio), the refractive index of the second functional layer 3 can be reduced. The void ratio is, for example, 0 to 70 vol%, preferably 10 to 50 vol%, and more preferably 20 to 50 vol%. This point is the same for the second functional layer consisting of multiple layers, which will be described later.

[0263] The second functional layer 3 is, for example, a cured product obtained by curing a predetermined liquid composition. This liquid composition contains hollow particles, polysilsesquioxane, and a solvent. The hollow particles are made of a material having a refractive index of 1.15 to 2.70. In the cured product obtained by coating the liquid composition onto a substrate and curing the liquid composition, at least one of the following conditions is satisfied: Ib / Ia ≥ 0.7 and Ib / Ic ≥ 0.3. The solvent contained in the liquid composition is, for example, an alcohol such as ethanol, methanol, 1-propanol, 2-propanol, or water.

[0264] The solution for the second functional layer can be applied to the first functional layer, the anti-fogging layer, by various methods such as spin coating, roll coating, and spray coating. However, methods such as roll coating and spray coating require leveling of the solution between coating and firing, which takes time. As a result, the solvent may evaporate during this time, potentially leading to uneven drying. This could result in, for example, differences in refractive index or film thickness between areas where the solvent has evaporated before network formation in the heating furnace and areas where solvent remains at the time of network formation in the binder.

[0265] Therefore, when performing coating at such high temperatures, it is preferable to use a high-boiling-point solvent. This suppresses the volatilization of the solvent in the solution for the second functional layer, thereby ensuring uniform refractive index and film thickness. Furthermore, since the formation of the network in the binder occurs through dehydration condensation reactions, a firing temperature of around 100°C is preferable. Therefore, it is preferable that the boiling point of the high-boiling-point solvent be 100°C or higher. In addition, since the first functional layer contains organic resin, yellowing may occur at temperatures above 300°C. Therefore, it is desirable that the firing temperature of the second functional layer be 300°C or lower. Conversely, if a solvent with a boiling point of 300°C or higher is used, a large amount of solvent may remain after firing. As a result, the refractive index of the second functional layer may change, and the desired optical properties may not be obtained. Therefore, it is preferable that the boiling point of the high-boiling-point solvent be between 100°C and 300°C.

[0266] The high-boiling point solvent is not particularly limited, but for example, it can be mainly composed of 1-methoxy-2-propanol or 3-methoxy-3-methyl-1-butanol. Furthermore, such a high-boiling point solvent can be present in solution at concentrations of, for example, 1 ppb or more and 5 g / cm³. 3 Preferably, it contains the following amount: 3 g / cm³ 3 It is even more preferable that the following conditions apply: 1 g / cm³ 3 The following is more preferable. The reason is as follows: In the solution for the second functional layer described above, a solvent with a temperature higher than the firing temperature is added, so more than 1 ppb of solvent remains in the second functional layer even after firing. Here, 5 g / cm³ is added to the second functional layer. 3 If the above solvents are present, the remaining solvent will Since the refractive index changes, there is a risk that the optical thin film will no longer perform its function. Therefore, the solvent should be 5 g / cm³. 3The following are preferably included. The volume of the second functional layer 3 is calculated from the average value of the thickness of the second functional layer 3 measured at 10 points and the area of ​​the second functional layer 3. The amount of high-boiling point solvent is calculated by analysis using a gas chromatograph or the like. Then, from the calculated volume and amount of solvent, the concentration of high-boiling point solvent in the second functional layer 3 (g / cm³) is calculated. 3 Calculate ).

[0267] Furthermore, since organosilane compounds having fluoroalkyl groups are unnecessary in this liquid composition, phase separation is less likely to occur, and the liquid composition tends to be more homogeneous. In addition, the liquid composition has high wettability to substrates and resin substrates, making it easier to obtain an anti-reflective layer with a uniform structure using the liquid composition.

[0268] In the cured product described above, the conditions Ib / Ia≧0.7 and Ib / Ic≧0.3 are preferably further satisfied.

[0269] In the cured product described above, preferably, at least one of the following conditions is met: Id / Ib ≤ 60, Ie / Ib ≤ 20, and If / Ib ≤ 174.

[0270] In the cured product described above, more preferably, the conditions Id / Ib ≤ 60, Ie / Ib ≤ 20, and If / Ib ≤ 174 are further satisfied.

[0271] In liquid compositions, polysilsesquioxane is, for example, a polysilsesquioxane in which a hydrocarbon group containing 16 or fewer carbon atoms is bonded to a silicon atom as a non-reactive functional group.

[0272] The characteristics of the hollow particles 31 in the second functional layer 3 typically also apply to hollow particles in liquid compositions. For this reason, hollow particles in liquid compositions have, for example, an average particle diameter (primary particle diameter) of 10 to 150 nm. Furthermore, hollow particles in liquid compositions are preferably made of at least one selected from the group consisting of silica, magnesium fluoride, alumina, aluminosilicate, titania, and zirconia.

[0273] The liquid composition may contain silica in addition to hollow particles, for example.

[0274] The second functional layer 3 is formed, for example, by applying a liquid composition to the first functional layer 2 and curing the liquid composition. This forms a low refractive index layer using the second functional layer 3. By using a liquid composition, the low refractive index coating can be simplified without requiring an organosilane compound having a fluoroalkyl group.

[0275] The polysilsesquioxane in the liquid composition is formed, for example, by the hydrolysis and dehydration condensation of a trifunctional alkoxysilane contained in the raw materials of the liquid composition. Furthermore, if the liquid composition contains silica in addition to hollow particles, this silica is formed, for example, by the hydrolysis and dehydration condensation of a tetrafunctional alkoxysilane contained in the raw materials of the liquid composition. For example, a tetrafunctional alkoxysilane forms silica (SiO2) through the reactions of (Formula 1) and (Formula 2) below. a represents an alkyl group. Trifunctional alkoxysilanes are converted to polysilsesquioxane (R) by the following reactions (Equation 3) and (Equation 4). b SiO 3 / 2 ) forms R b R indicates a non-reactive functional group. c This indicates an alkyl group. Si(OR a )4 + 4H2O → Si(OH)4 + 4R a OH (Formula 1) Si(OH)4→SiO2+2H2O (Formula 2) R b Si(OR c )3 + 3H2O → R b Si(OH)3+3R c OH (Formula 3) R b Si(OH)3→R b SiO 3 / 2 +3 / 2H2O (Formula 4)

[0276] The hydrolysis catalysts included in the raw materials of the liquid composition are, for example, carboxylic acids such as formic acid and acetic acid.

[0277] <3. Adjusting the refractive index> For the second functional layer 3 to function properly as an anti-reflective layer, it is necessary to determine the refractive index of the second functional layer 3 by considering the refractive index of the first functional layer 2, which is the anti-fog layer. The refractive index of the anti-fog layer is generally 1.5 to 1.6, although this varies depending on the material. It is known that in order to lower the overall refractive index of the first functional layer 2 and the second functional layer 3, the refractive index of the second functional layer 3 should be set to the square root of the refractive index of the first functional layer 1. For example, if the refractive index of the anti-fog layer is 1.55, it is preferable to set the refractive index of the second functional layer 3 to 1.24.

[0278] As described above, the second functional layer 3 is composed of hollow particles 31, a binder 32, and an air layer. Because it contains hollow particles with air, its refractive index can be lowered. Furthermore, because it also contains an air layer, increasing its proportion (void fraction) can further reduce the refractive index. Therefore, by adjusting the proportion of hollow particles and the void fraction, the refractive index of the second functional layer 3 can be set to, for example, approximately ±0.1 of the refractive index of the first functional layer 2.

[0279] <4. Second functional layer consisting of multiple layers> In the example described above, the second functional layer 3 is formed as a single layer, but it can also be formed as two layers. For example, as shown in Figure 8, the second functional layer 3 can be composed of a first layer 301 laminated on the first functional layer 2, and a second layer 302 laminated on this first layer 301. In order to reduce the refractive index of the functional layers 2 and 3 as a whole, the refractive index of the first layer 301 is made smaller than that of the anti-fog layer 2, and furthermore, the refractive index of the second layer 302 is made smaller than that of the first layer 301. The refractive index of the first layer 301 can be, for example, 1.35 to 1.55, and the refractive index of the second layer 302 can be, for example, 1.10 to 1.25.

[0280] As an example, the second layer 302 is formed from the single-layer second functional layer 3 described above. The first layer 301 is the second layer 302 with the hollow particles 31 removed, and is a layer consisting of at least one of the binder, polysilsesquioxane and silica. The thickness of this second layer 302 can be, for example, 30 to 300 nm. Although the first layer 301 does not contain hollow particles or an air layer, water vapor passes through it because the binder 32 is porous. Therefore, even if such a first layer 301 is formed, water vapor reaches the anti-fogging layer 2 through the first layer 301 and the second layer 302. However, since water vapor does not pass through as easily as through the second layer 302, it is preferable that the thickness of the first layer 301 be thinner than that of the second layer 302.

[0281] Thus, when the second functional layer 3 is formed from multiple layers, the refractive index of each layer should be gradually decreased from the first functional layer 2 towards the outermost layer. Therefore, the second functional layer 3 can be formed from three or more layers.

[0282] <5. Physical properties of the second functional layer> If the first functional layer 2 is an anti-fogging layer, its volume may change due to moisture absorption. Since the second functional layer 3 is laminated on the first functional layer 2, it is preferable that the second functional layer 3 follows the volume change of the first functional layer 2. If the follow-up is insufficient, cracks may occur in the second functional layer 3. Therefore, for example, if the flexural modulus of the anti-fogging layer 2 is 2 to 3 GPa, the flexural modulus of the second functional layer 3 is preferably in a range that overlaps with the flexural modulus of the anti-fogging layer 2, for example, 1 to 10 GPa, and more preferably 1 to 4 GPa. In other words, polysilsesquioxane (flexural modulus of 2 to 3 GPa) exhibiting a similar flexural modulus to that of the anti-fogging layer 2 can be suitably used as the binder for the second functional layer 3.

[0283] Furthermore, since the first and second functional layers may expand and contract due to temperature changes, it is preferable that the difference in the linear thermal expansion coefficients of the first functional layer 2 and the second functional layer 3 be 30 ppm / °C. For example, the linear thermal expansion coefficient of the anti-fogging layer is 60-84 ppm / °C, while the linear thermal expansion coefficient of polysilsesquioxane is 40-70 ppm / °C, so it can be used as a binder for the second functional layer 3. In other words, even if the film volume increases or decreases due to the amount of water absorbed by the anti-fogging layer, cracks in the first functional layer 2 and the second functional layer 3 can be suppressed.

[0284] <6. Other aspects> The first functional layer 2 and the second functional layer 3 in this embodiment can be made into various forms. For example, when the second functional layer 3 is a single layer, as shown in Figure 9, the anti-fog layer 2 and the anti-reflective layer 3 are laminated on the base film 81 in that order, and then the base film 81 can be attached to the base material 1 via an adhesive layer (not shown). Similarly, when the second functional layer 3 is a multi-layer, as shown in Figure 10, the anti-fog layer 2, the first layer 301 and the second layer 302 of the anti-reflective layer are laminated on the base film 81 in that order, and then the base film 81 can be attached to the base material 1 via an adhesive layer 82. The base film 81 and the adhesive layer 82 are the same as those shown in the first embodiment.

[0285] The transparent laminate of the present invention may contain an ultraviolet absorber and / or an infrared absorber. At least one of the first functional layer, second functional layer, and third functional layer described above may contain an ultraviolet absorber and / or an infrared absorber.

[0286] Alternatively, at least one of the above-mentioned base film, adhesive layer, and anti-fogging layer may contain an ultraviolet absorber and / or an infrared absorber.

[0287] Examples of UV absorbers include benzotriazole compounds [2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, etc.], benzophenone compounds [2,2',4,4'-tetrahydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone, etc.)], and hydroxyphenyltriazine. Examples of organic substances include compounds [2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-di-t-butylphenyl)-s-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-s-triazine, 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-t-butylphenyl)-s-triazine, etc.] and cyanoacrylate compounds [ethyl-α-cyano-β,β-diphenyl acrylate, methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate, etc.]. The UV absorber may be used alone or in combination of two or more types. The UV absorber may also be at least one organic dye selected from polymethine compounds, imidazoline compounds, coumarin compounds, naphthalimide compounds, perylene compounds, azo compounds, isoindolinone compounds, quinophthalone compounds, and quinoline compounds. Among the ultraviolet absorbers, organic ultraviolet absorbers are preferred, more preferably at least one selected from benzotriazole compounds, benzophenone compounds, hydroxyphenyltriazine compounds, and cyanoacrylate compounds, and even more preferably benzophenone compounds. Benzophenone compounds are preferred because they have good solubility in alcohol-based solvents contained in the coating solution for forming an organic-inorganic composite anti-fogging film and are uniformly dispersed by the polyvinyl acetal resin.

[0288] The UV absorber preferably has hydroxyl groups, and more preferably has two or more hydroxyl groups bonded to one benzene skeleton of the UV absorber. The UV absorber is preferably added in an amount of 0.1 to 50 parts by weight, more preferably 1.0 to 40 parts by weight, and even more preferably 2 to 35 parts by weight, per 100 parts by weight of the water-absorbing resin.

[0289] Examples of infrared absorbers include organic infrared absorbers such as polymethine compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, naphthoquinone compounds, anthraquinone compounds, dithiol compounds, immonium compounds, diimonium compounds, aminium compounds, pyrylium compounds, cerylium compounds, squalylium compounds, and counterionic conjugates of benzenedithiol metal complex anions and cyanine dye cations; and inorganic infrared absorbers such as tungsten oxide, tin oxide, indium oxide, magnesium oxide, titanium oxide, chromium oxide, zirconium oxide, nickel oxide, aluminum oxide, zinc oxide, iron oxide, ammonium oxide, lead oxide, bismuth oxide, lanthanum oxide, tungsten oxide, indium tin oxide, and antimony tin oxide. Infrared absorbers may be used alone or in combination of two or more. Of the infrared absorbers, inorganic infrared absorbers are preferred, and indium tin oxide and / or antimony tin oxide are more preferred.

[0290] Indium tin oxide and / or antimony tin oxide are preferred because they have good stability in the coating solution for forming an organic-inorganic composite anti-fogging film and are uniformly dispersed by the polyvinyl acetal resin. The infrared absorber is preferably added in an amount of 0.1 to 50 parts by weight, more preferably 1.0 to 40 parts by weight, and even more preferably 2 to 35 parts by weight, per 100 parts by weight of the water-absorbing resin.

[0291] The first functional layer 2 and the second functional layer 3 do not have to be adjacent. For example, a primer layer, an absorption layer that absorbs a specific wavelength, or a modification layer may be provided between the first functional layer 2 and the second functional layer 3.

[0292] <7.Applications> The cover member according to this embodiment, like the first embodiment described above, can be used as a cover member for an imaging device installed on an aircraft such as a drone, or as a cover member for a surveillance camera. In particular, if an anti-reflective layer is formed as the second functional layer 3, it can be suitably used as a cover member for an imaging device on an aircraft, which often takes pictures outdoors where the environment changes. In particular, when an aircraft ascends rapidly, the pressure changes rapidly. As can be understood from Boyle's Law and Charles's Law, when the pressure decreases, the temperature decreases. Therefore, the transparent laminate with anti-fogging function according to the present invention can be suitably used.

[0293] [Examples] Examples 21 to 27 according to the second embodiment will be described below. However, the present invention is not limited to the following examples.

[0294] (Example 21) As Example 21, the following cover member was fabricated. (1) Substrate: Float glass with a thickness of 2.8 mm was used. (2) First functional layer: The anti-fogging layer shown in Example 1 of the first embodiment was formed on the first main surface of the substrate. However, a hydrophilic layer was not formed in this anti-fogging layer. The film thickness was 8 μm and the refractive index was 1.55. (3) Second functional layer: A single-layer anti-reflective layer as shown below was formed.

[0295] After forming the anti-fogging layer, a coating solution for the anti-reflective layer was prepared as follows. First, 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 hollow silica particle sol (manufactured by JGC Catalysts & Chemicals Co., Ltd., product name: Thru-Ria 4110, silica solids content: approximately 25 mass%), and 22.4 g of ethanol (manufactured by Kishida Chemical Co., Ltd.) were mixed and reacted at 35°C for 3 hours. In this way, a coating solution for the second functional layer according to Example 22 was obtained. In the hollow silica particle sol, the average particle diameter of the hollow silica particles was approximately 50 nm, the thickness of the silica shell was 10-20 nm, the maximum dimension of the internal space of the hollow silica particles was approximately 10-30 nm, and the refractive index of the hollow silica particles was 1.25. The solid content of this coating liquid contained 0.6% by mass of silica derived from TEOS, 1.6% by mass of polymethylsilsesquioxane derived from MTES, and 2.6% by mass of hollow silica particles. The ratio of the amount of MTES to the amount of TEOS added in the preparation of the liquid composition according to Example 1 was 7 / 3. The ratio of the weight of hollow silica particles to the total weight of the solid content of silica derived from TEOS and polymethylsilsesquioxane derived from MTES was 1.3 / 1.1.

[0296] Next, the above coating liquid was applied to the anti-fogging layer by spin coating. Immediately after application, the appearance was good and a uniform coating film was obtained. Subsequently, the coating film was dried in an oven at 200°C for 10 minutes to obtain the cover member according to Example 22.

[0297] The anti-reflective coating had a thickness of 100 nm and a refractive index of 1.24 ± 0.5. The volume ratio of the materials constituting this anti-reflective coating was as follows: 50 vol% hollow silica particles, 23 vol% binder, and 23 vol% void ratio.

[0298] (Example 22) As Example 22, the following cover component was fabricated. (1) Substrate: Float glass with a thickness of 2.8 mm was used. (2) First functional layer: The anti-fogging layer shown in Example 1 of the first embodiment was formed on the first main surface of the substrate. However, a hydrophilic layer was not formed in this anti-fogging layer. The film thickness was 8 μm and the refractive index was 1.55. (3) Second functional layer: The following two anti-reflective layers were formed.

[0299] After forming the anti-fogging layer, a coating solution for the anti-reflective layer was prepared as follows. Specifically, the coating solution for the first layer was prepared in the same manner as the coating solution in Example 21, except that a sol of hollow silica particles was not added. This coating solution was then applied to the anti-fogging layer by spin coating. Next, the coating film was dried in an oven at 200°C for 10 minutes to form the first layer. The refractive index of this first layer was 1.46 and the thickness was 90 nm.

[0300] Then, a coating solution similar to that used in Example 21 was applied to this first layer by spin coating. However, compared to the coating solution used in Example 21, the proportion of hollow silica particles and the void ratio were increased. Next, this coating film was dried in an oven at 200°C for 10 minutes to form a second layer. The refractive index of this second layer was 1.16 and the thickness was 95 nm.

[0301] (Examples 23-27) As Examples 23-27, the following cover members were fabricated. (1) Substrate: Glanova (manufactured by Nippon Sheet Glass Co., Ltd.) with a thickness of 1.1 mm was used. (2) First functional layer: The anti-fogging layer shown in Example 1 of the first embodiment was formed on the first main surface of the substrate. However, a hydrophilic layer was not formed in this anti-fogging layer. The film thickness was 8 μm and the refractive index was 1.55. (3) Second functional layer: A single-layer anti-reflective layer as shown below was formed.

[0302] After forming the anti-fogging layer, coating solutions for the anti-reflective layer were prepared with the compositions shown in Table 10 (units are in mass%). First, tetraethoxysilane (TEOS) (manufactured by Tokyo Chemical Industry Co., Ltd.), methyltriethoxysilane (MTES) (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.3 mass% formic acid (manufactured by Kishida Chemical Co., Ltd.), hollow silica particle sol (manufactured by JGC Catalysts & Chemicals Co., Ltd., product name: Thru-Ria 4110, silica solids content: approximately 25 mass%), solvent, and leveling agent were mixed and reacted at 35°C for 3 hours. In this way, coating solutions for the second functional layer according to Examples 23 to 27 were obtained. In the hollow silica particle sol, the average particle diameter of the hollow silica particles was approximately 50 nm, the thickness of the silica shell was 10 to 20 nm, the maximum dimension of the internal space of the hollow silica particles was approximately 10 to 30 nm, and the refractive index of the hollow silica particles was 1.25.

[0303] [Table 10]

[0304] The solvents, leveling agents, etc., shown in Table 10 are as follows. Of these, E to H are high-boiling point solvents with a boiling point of 100°C or higher. A: methanol B: Ethanol C:2-propanol D:1-Propanol E: 1-butanol F: 1-Methoxy-2-propanol G:3-Methoxy-3-methyl-1-butanol H:3-Methoxy-3-methyl-1-butylacetate MIBK: Methyl isobutyl ketone KP-341: Leveling agent (manufactured by Shin-Etsu Chemical Co., Ltd.) BYK-378_10%: Leveling agent (manufactured by BIC Chemie Japan Co., Ltd.)

[0305] Next, the coating solution according to Example 23 was applied to the anti-fogging layer by spin coating, and the coating solutions according to Examples 24-27 were applied by roll coating. Immediately after application, the appearance was good and a uniform coating film was obtained. Subsequently, the coating film was dried in a heating furnace at 120°C for 10 minutes to obtain the cover members according to Examples 24-27.

[0306] When the second functional layer of the cover members formed in Examples 24 to 27 was blown with exhaled breath and its anti-fogging performance was evaluated, no fogging occurred in any of them.

[0307] Next, the single-sided reflectance of Examples 23 and 26 was measured. The results are shown in Figure 11. The average visible light reflectance of Examples 23 and 26 was 0.71% and 0.31%, respectively. Although not shown in the figure, the reflectance of a cover member with only an anti-fog layer and no second functional layer was 4-5%. Therefore, it was found that the reflectance of the cover members of Examples 23 and 26 can be significantly reduced.

[0308] (Examples 28-30) As Examples 28-30, the following cover components were fabricated. First, an anti-fog film (manufactured by Fujifilm, model number: MF-600) was prepared. This film is made by laminating a TAC (triacetylcellulose) film, which has a modified layer (anti-fog layer) that exhibits anti-fog properties by modifying the surface of the TAC film, with a PET film via an adhesive layer. Specifically, a film with the following configuration was prepared: protective film (PE: 60 μm) / TAC modified layer (5 μm) / TAC (120 μm) / adhesive layer (15 μm) / PET (50 μm) / adhesive layer (25 μm) / protective film (PET: 38 μm).

[0309] Next, the protective film (PE: 60 μm) on the TAC modified layer side was peeled off, and the surface of the TAC modified layer was subjected to corona discharge treatment (Shinko Electric Instruments Co., Ltd., model: Corona Master PS-1M, 14.5 kW). The coating solution from Example 21 was applied to the corona discharge treated surface by spin coating (5000 rpm, 20 seconds, room temperature) (Example 28). The surface was treated at a firing temperature of 120°C for 10 minutes. The single-sided reflectance of the surface on which the anti-reflective layer was formed was measured using a reflectance measuring device (Olympus Corporation, model: USPM-RU III). This device allows for highly accurate spectral reflectance measurement without being affected by back-surface reflected light. The refractive index calculated from the reflectance obtained with the reflectance measuring device was 1.2382, and the film thickness was 107 nm (Table 11). Furthermore, anti-reflective layers with different film thicknesses were formed on the film by changing the spin coating rotation speed (Examples 29 and 30).

[0310] As described above, after forming an anti-reflective film on the TAC modified layer (anti-fogging layer), the protective film (PET: 38 μm) on the adhesive layer side was peeled off, and the adhesive layer side was attached to a glass substrate (manufactured by Nippon Sheet Glass Co., Ltd., product name: Glanova, thickness: 2.1 mm). In this way, the cover members according to Examples 28 to 30 were completed. Subsequently, they were evaluated as follows. [Table 11]

[0311] Figure 12 shows the single-sided reflectance of the films with the anti-reflective coatings formed in Examples 28-30 in the 400-700 nm range. The single-sided reflectance of films without the anti-reflective coating is shown as the film without the anti-reflective layer. As is clear from Figure 12, when the anti-reflective coating of the present invention is not formed, i.e., the single-sided reflectance of the anti-fogging layer (TAC modified layer) is 4% or more, whereas when the anti-reflective coating is formed on the anti-fogging layer (TAC modified layer) as in Examples 28-30, the single-sided reflectance in the 400-700 nm range is less than 1%, demonstrating a significant anti-reflective effect.

[0312] Furthermore, when exhaled breath was blown onto the anti-fog layers with the anti-reflective coatings of Examples 28-30 and their anti-fog performance was evaluated, no fogging occurred in any of the cases.

[0313] <C. Modified Example> As described above, the embodiments of the present invention have been explained. However, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit thereof. In addition, the following modified examples can be combined as appropriate.

[0314] <1> The base material 1 may be a composite material of a resin material and a glass plate, or may be a laminated glass in which an intermediate film is sandwiched between two glass plates.

[0315] <2> The base material 1 may be, for example, a mirror having an antiglare layer (or a surface subjected to antiglare treatment).

[0316] In the case of a mirror, peeling of the film may occur at the location where the user touches it, and it is often used for a long period of time. Durability against peeling of the surface film is required. Therefore, as described above, when the antifogging layer is directly applied to the mirror which is the base material, the base material (glass plate) and the antifogging layer are firmly bonded by a siloxane bond, and high durability can be expected even in long-term use.

[0317] In addition, when the mirror is used in a bathroom or a washstand, since it is a particularly high-humidity environment, high antifogging property is required. On the other hand, if the antifogging layer only has water absorption performance, when the saturation amount is exceeded, water droplets will occur on the surface of the antifogging layer, which causes fogging. Therefore, when the hydrophilic layer as described above is formed on the surface of the antifogging layer, when the moisture absorption layer is saturated, a water film will occur on the surface. Therefore, even in a high-humidity environment, it is possible to avoid the image from becoming invisible due to fogging. Here, the occurrence of a water film means that the contact angle of water becomes 20 degrees or less. In addition, not only the hydrophilic layer but also a water-repellent layer may be provided. The water-repellent layer mentioned here means a layer in which the contact angle of water becomes 90 degrees or less.

[0318] When using a mirror as the base material, it is preferable to laminate an anti-fog layer that does not have a base film such as PET as described above. Without a base film, distortion caused by the base film can be prevented. In particular, mirrors require clear image and high distortion. Furthermore, in a mirror, both incident and reflected light pass through the anti-fog layer. That is, light passes through the anti-fog layer twice, so an anti-fog layer without a base film is particularly advantageous in terms of distortion. If the thickness of the anti-fog layer is constant, such as 1 to 20 μm, the bending rigidity is 1 to 4 GPa, making it possible to handle even without a base film such as PET. Additionally, an anti-fog layer with high tensile strength is preferable.

[0319] <3> In the second embodiment described above, an example was shown in which a second functional layer, which is an anti-reflective layer, is laminated on a first functional layer. However, such an anti-reflective layer can also be directly laminated onto the substrate 1 as the first functional layer. In this case, in addition to directly laminating the first functional layer onto the substrate, a sheet material can also be prepared by laminating an adhesive layer, a base sheet, and the first functional layer in this order, and then attaching the adhesive layer to the substrate. In this case, the base sheet can be made of, for example, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, or an acrylic resin. The adhesive layer only needs to be able to fix the base sheet to the substrate 1 with sufficient strength. Specifically, an adhesive layer such as an acrylic, rubber, or methacrylic resin copolymerized with an acrylic monomer and set to a desired glass transition temperature can be used. The anti-reflective layer may contain a second solvent whose boiling point is greater than the boiling point of water and is below the heat resistance temperature of the base sheet.

[0320] Furthermore, this anti-reflective first functional layer can also be formed in two layers. That is, it can have the same configuration as the second functional layer 3 explained using Figure 8. [Explanation of Symbols]

[0321] 1 circuit board 11. First Main Surface 12 Second Main Surface 2. First functional layer 3. Second functional layer

Claims

1. A transparent substrate having a first main surface and a second main surface, A transparent first functional layer is laminated on the first main surface of the substrate, A second functional layer, which is laminated on the first functional layer and has moisture permeability, Equipped with, The first functional layer is, It has a hygroscopic anti-fogging layer containing a water-absorbing resin, a metal oxide having a water-repellent group, and inorganic fine particles made of an oxide of at least one element selected from Ti, Ta, and Nb. The aforementioned second functional layer is, It contains hollow particles and a binder that binds the hollow particles together, When the refractive index of the first functional layer is X, the refractive index of the second functional layer is √X ± 0.

1. Transparent laminate.

2. The transparent laminate according to claim 1, wherein the surface roughness Ra of the first functional layer is 1 to 1000 nm.

3. The first functional layer is, A base film having a first main surface and a second main surface, An adhesive layer laminated on the second main surface of the base film, The anti-fogging layer laminated on the first main surface of the base film, Equipped with, The transparent laminate according to claim 1 or 2, wherein the base film is fixed to the first main surface of the substrate via the adhesive layer.

4. The first functional layer comprises an adhesive layer and the anti-fogging layer, The transparent laminate according to claim 1 or 2, wherein the anti-fogging layer is fixed to the first main surface of the substrate via the adhesive layer.

5. The first functional layer comprises the anti-fogging layer, The transparent laminate according to claim 1 or 2, wherein the anti-fogging layer is laminated on the first main surface of the substrate.

6. The transparent laminate according to claim 1, wherein the refractive index of the hollow particles is 1.15 to 2.

70.

7. The transparent laminate according to claim 1 or 6, wherein the average particle size of the hollow particles is 20 to 100 nm.

8. The transparent laminate according to any one of claims 1, 6, or 7, wherein the hollow particles are selected from the group consisting of silica, magnesium fluoride, alumina, aluminosilicate, titania, and zirconia.

9. The transparent laminate according to any one of claims 1, 6 to 8, wherein the second functional layer contains a solvent having a boiling point of 100°C or more and 300°C or less.

10. The transparent laminate according to claim 9, wherein the solvent mainly comprises 3-methoxy-3methyl-1-butanol.

11. The second functional layer contains the solvent at a concentration of 1 ppb or more, or 5 g / cm³. 3 The transparent laminate according to claim 9 or 10, comprising the following:

12. The transparent laminate according to any one of claims 1, 6 to 8, wherein the binder contains at least one of polysilsesquioxane and silica.

13. The transparent laminate according to any one of claims 1, 6 to 12, wherein the void ratio of the second functional layer is 0 to 70 vol%.

14. The transparent laminate according to claim 1, wherein the second functional layer comprises a first layer laminated on the first functional layer and a second layer laminated on the first layer having a lower refractive index than the first layer.

15. The transparent laminate according to claim 1, wherein the refractive index of the hollow particles is 1.15 to 2.

70.

16. The transparent laminate according to claim 1 or 15, wherein the average particle size of the hollow particles is 20 to 100 nm.

17. The hollow particles are silica, magnesium fluoride, alumina, aluminum silicate, titanium A transparent laminate according to any one of claims 1, 15, or 16, selected from the group consisting of nia and zirconia.

18. The transparent laminate according to any one of claims 2 to 17, wherein the substrate is float glass manufactured by the float method, and the concentration of tin oxide on the first main surface is lower than the concentration of tin oxide on the second main surface.

19. The transparent laminate according to any one of claims 2 to 17, wherein the substrate is float glass manufactured by the float method, and the concentration of tin oxide on the first main surface is higher than the concentration of tin oxide on the second main surface.

20. The transparent laminate according to any one of claims 1 to 19, further comprising a third functional layer laminated on the second main surface of the substrate.

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