Optical product and method for manufacturing optical product

Abstract

The present invention provides an optical product having a film with a fine concavo-convex structure made of a material other than aluminum or its compounds, and a manufacturing method capable of easily manufacturing the optical product. The optical product (1) includes a substrate (2) and an optical film (4) formed on its film-forming surface (F). The optical film (4) has: an Al2O3 layer (12), which is an Al2O3 layer disposed on the side of the substrate (2); and a SiO2 layer (14), which is a SiO2 layer having a fine concavo-convex structure. The manufacturing method of the optical product (1) includes: a step of forming an Al-based manufacturing intermediate film, which is aluminum, an aluminum alloy, or a compound of aluminum, on the substrate (2); and a step of immersing the substrate (2) with the Al-based manufacturing intermediate film in an aqueous solution of silica. The concentration of silica in the aqueous solution is 10 mg / l or less.

Description

Technical Field

[0001] The present invention relates to an optical product formed with a film having fine irregularities and a method for producing the optical product. Background Art

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-198330) describes forming a layer of a fine concavo-convex structure of aluminum or its compound on the outermost surface of a curved substrate by vapor phase film formation and hydrothermal treatment at 60°C or higher and below the boiling temperature.

[0003] The average height of the convex parts in the concavo-convex structure is about 5 to 1000 nm (nanometers).

[0004] The density in the film (moth eye) of this fine concavoconvex structure decreases from the substrate side to the air side. As a result, the refractive index of the film gradually changes. Therefore, the film plays a role in eliminating the optical interface, or plays the same role as a low-refractive-index film. The film exhibits an anti-reflection effect through these effects and can be used as an anti-reflection film.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-198330 Summary of the invention

[0008] Problems to be solved by the invention

[0009] As described above, it is known that a fine concavo-convex structure made of aluminum or a compound thereof is formed from aluminum or a compound thereof.

[0010] However, the formation of fine concavo-convex structures made of other materials, especially silicon dioxide (SiO2), is not known.

[0011] Therefore, a main object of the present invention is to provide an optical product having a film with a fine concavo-convex structure made of a material other than aluminum or a compound thereof.

[0012] In addition, another main object of the present invention is to provide a method for manufacturing an optical product that can easily produce an optical product having a film with a fine concavo-convex structure made of a material other than aluminum or its compound.

[0013] Means for solving problems

[0014] In order to achieve the above-mentioned purpose, an optical product is provided, which comprises: a substrate; and an optical film, which is directly or indirectly formed on the film-forming surface of the above-mentioned substrate, and the above-mentioned optical film has: an Al2O3 layer, which is an Al2O3 layer arranged on the above-mentioned substrate side; and a SiO2 layer, which is a SiO2 layer having a fine concave-convex structure.

[0015] In addition, in order to achieve the above-mentioned purpose, a method for manufacturing an optical product is provided, which comprises: a process of forming an Al-based intermediate film which is aluminum, aluminum alloy or aluminum compound on a substrate; and a process of immersing the substrate with the Al-based intermediate film in an aqueous solution of silica, wherein the concentration of the silica in the aqueous solution is less than 10 mg / l.

[0016] Effects of the Invention

[0017] The main effect of the present invention is to provide an optical product having a film with a fine concavo-convex structure made of a material other than aluminum or a compound thereof.

[0018] Another major effect of the present invention is to provide a method for manufacturing an optical product that can easily produce an optical product having a film with a fine concavo-convex structure made of a material other than aluminum or its compound. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic cross-sectional view of the optical product of the present invention.

[0020] Figure 2 yes Figure 1 Schematic cross-sectional view of an intermediate in the manufacture of an optical product.

[0021] Figure 3 (A)~(F) are Figure 1 Schematic diagram of a method for manufacturing an optical product.

[0022] Figure 4 This is a graph of the single-surface reflectivity at vertical incidence in Example 1.

[0023] Figure 5 This is a graph of the transmittance at vertical incidence in Example 1.

[0024] Figure 6 This is a graph showing the reflectance of both surfaces of light at various incident angles θ in Example 1.

[0025] Figure 7 This is a graph showing the incidence angle dependency of the two-surface reflectance in Example 1.

[0026] Figure 8 This is a graph of the spectrum of characteristic X-rays in the same observation object as in Example 1.

[0027] Fig. 9 yes Figure 8 Observation image of the observation object in TEM.

[0028] Fig.10 yes Figure 8 C-Kα ray overlapping image of the observed object.

[0029] Fig.11 yes Figure 8 O-Kα ray overlapping images of the observed object.

[0030] Fig.12 yes Figure 8 Al-Kα ray overlapping images in the observed object.

[0031] Fig.13 yes Figure 8 The Si-Kα ray overlapping image in the observed object.

[0032] Fig.14 This is a graph of the single-surface reflectance at normal incidence in Examples 2 to 6.

[0033] Fig.15 is the same as in Examples 7 to 11 Fig.14 Same picture.

[0034] Fig.16 is the same as in Examples 12 to 16 Fig.14 Same picture.

[0035] Fig.17 is the same as in Examples 17 to 20 Fig.14 Same picture.

[0036] Fig.18 is the same as in Examples 21 to 26 Fig.14 Same picture.

[0037] Fig.19 is the same as in Examples 27 to 31 Fig.14 Same picture.

[0038] Fig. 20 Examples 32 to 37 and Comparative Example 1 Fig.14 Same picture.

[0039] Fig.21 This is a graph of single-surface reflectance at normal incidence in Examples 2, 7, 10, 15, and 18 in which the temperature of the solution used as the immersion destination during production is different from each other.

[0040] Fig. 22 It is a graph of the average reflectance in Examples 2, 7, 10, 15, and 18.

[0041] Fig.23 It is a graph showing the relationship between the average reflectance (vertical axis) and the silica concentration (horizontal axis) of the solution in Examples 32 to 37 and Comparative Example 1. DETAILED DESCRIPTION

[0042] Hereinafter, examples of embodiments of the present invention will be described using drawings as appropriate.

[0043] It should be noted that the present invention is not limited to the following examples.

[0044] [Composition, etc.]

[0045] like Figure 1 As shown, the optical product 1 of the present invention includes a substrate 2 and an optical film 4 formed on a film-forming surface F of the substrate 2. It should be noted that the thickness of the optical film 4 is exaggerated relative to the thickness of the substrate 2 in the drawings.

[0046] The optical product 1 is used as a light-transmitting antireflection member. That is, in the optical product 1, the optical film 4 can suppress the intensity of the reflected light R1 relative to the intensity of the incident light I1 (incident angle θ) to the optical product 1.

[0047] It should be noted that in Figure 1 , the incident light I1 is transmitted through the surface opposite to the incident surface, that is, the transmitted light I2, and the incident light I1 is reflected from the surface, that is, the reflected light R2. The optical product 1 can also be used for components other than antireflection components.

[0048] The substrate 2 is the basis for forming the optical product 1, and is in the form of a plate (substrate) in this case. The substrate 2 is light-transmissive, and the transmittance of the substrate 2 for light having a wavelength in the visible light region (here, 400 nm to 750 nm), i.e., visible light, is approximately 100%. It should be noted that the shape of the substrate 2 may be a flat plate, a curved plate, or a block or other shape other than a plate.

[0049] As the material (material) of the substrate 2, plastic is used, and polycarbonate resin (PC) as a thermosetting resin is used here. It should be noted that the material of the substrate 2 is not limited to PC, and can be, for example, polyurethane resin, thiourethane resin, episulfide resin, polyester resin, acrylic resin, polyethersulfone resin, poly-4-methylpentene-1 resin, diethylene glycol bisallyl carbonate resin, or a combination thereof. In addition, the material of the substrate 2 can be a material other than plastics such as glass.

[0050] The film-forming surface F of the substrate 2 is arranged on the front and back sides, and the optical film 4 is directly arranged on the front and back sides. It should be noted that the optical film 4 can be arranged on one of the front and back sides, or can be arranged on three or more sides in a block-shaped substrate 2 or the like. In addition, an intermediate film such as a hard coating film can be arranged between at least one of the optical films 4 and the substrate 2. In the case where such an intermediate film is provided, the optical film 4 is indirectly formed on the substrate 2.

[0051] The optical film 4 on the back side has the same configuration as that of the optical film 4 on the front side. Next, the optical film 4 on the front side will be described, and the description of the optical film 4 on the back side will be omitted as appropriate.

[0052] The optical film 4 includes an Al2O3 layer 12 made of aluminum oxide as the first layer and an SiO2 layer 14 made of silicon dioxide having a fine concavo-convex structure as the second layer, as counted from the substrate 2 side (the same applies hereinafter).

[0053] Alternatively, the optical film 4 has a first layer having a layer whose main component is Al2O3, namely, an Al2O3 layer, and a second layer having a layer whose main component is SiO2, namely, a SiO2 layer 14 having a fine concave-convex structure. In this case, the boundary between the first layer and the second layer is sometimes unclear. In addition, typically, in the first layer, the closer to the substrate 2, the higher the composition ratio of Al2O3, and the farther away from the substrate 2, the more the composition ratio of SiO2 relative to Al2O3 increases. That is, in the film thickness direction, the composition ratio of SiO2 to Al2O3 in the first layer is directly proportional to the distance from the substrate 2. The first layer has nothing to do with the distribution of the material and can be considered as a thin film layer without a fine concave-convex structure. Alternatively, the first layer can be considered as the foundation (root) of the fine concave-convex structure. Alternatively, the first layer can be considered as a thin film without a fine concave-convex structure, and the material gradually changes within the layer. In addition, the second layer can contain Al2O3 in a state where it does not become a main component. For example, the second layer can have a core (skeleton) of a fine concavo-convex structure with Al2O3 as the main component and a covering layer with SiO2 as the main component covering part or all of the core. The second layer is irrelevant to the distribution of the material and can be considered as a layer having a fine concavo-convex structure.

[0054] The height of the SiO2 layer 14 is, for example, about 1 nm to 1000 nm (nanoscale order). The fine concavoconvex structure in the SiO2 layer 14 is, for example, a fuzzy structure, a pyramid cluster structure, or a rosette structure, or a combination thereof.

[0055] [Manufacturing method, etc.]

[0056] Optical products 1 Figure 2 The intermediate manufacturing body 20 shown is manufactured. The intermediate manufacturing body 20 includes a substrate 2 and an Al-based intermediate manufacturing film 22 formed on a film forming surface F.

[0057] Here, each Al-based intermediate film 22 is made of AlN (aluminum nitride). The element ratio of Al and N in aluminum nitride may be any element ratio as long as they are stable.

[0058] It should be noted that the material (material) of the Al-based intermediate film 22 on at least one side may be aluminum, an aluminum alloy, or an aluminum compound other than AlN, for example, Al, Al2O3, AlON (aluminum oxynitride), or a combination of at least two selected from the group consisting of these and AlN. The element ratio of Al to N, the element ratio of Al to O, and the element ratio of O to N in aluminum oxynitride are the same as those of aluminum nitride. In the case where there are a plurality of Al-based intermediate films 22, the material of some of the Al-based intermediate films 22 may be different from the material of other Al-based intermediate films 22.

[0059] Aluminum alloys and aluminum compounds may be alloys or compounds with aluminum as the main component. Here, the main component may be a component that accounts for more than half of the other components in terms of weight ratio, or a component that accounts for more than half in terms of volume ratio, or a component that accounts for more than half in terms of element ratio. Such matters related to the main component are also appropriately applicable to cases other than the Al-based intermediate film 22.

[0060] Figure 3 is a schematic diagram of a method for manufacturing the optical product 1 . Figure 3 In the figure, for the sake of simplicity, the film-forming surface F is only a single surface.

[0061] for Figure 3 The film-forming surface F of the substrate 2 shown in (A) is as follows Figure 3 As shown in (B), the Al-based intermediate film 22 is formed. The Al-based intermediate film 22 is formed directly on the substrate 2 by physical vapor deposition (Physical Vapor Deposition (PVD), vacuum evaporation, sputtering, etc.). It should be noted that if the Al-based intermediate film 22 is formed on both sides of the substrate 2, the optical film 4 is formed on both sides of the substrate 2.

[0062] The following describes a case where the Al-based intermediate film 22 made of AlN is formed by DC sputtering in a DC sputtering film forming apparatus.

[0063] That is, first, a plate-shaped target made of Al is set, the film forming chamber is evacuated, and as a pretreatment, O2 gas is supplied to the film forming chamber at a predetermined flow rate (e.g., 500 ccm (cubic centimeters per minute)) from a radical source in a state of radical oxygen by applying a high-frequency voltage, and the substrate 2 is cleaned. More specifically, by irradiation with such radical oxygen, even if organic matter and the like are attached to the substrate 2, the organic matter and the like are decomposed and peeled off by the ultraviolet rays generated by the radical oxygen and the plasma. By such cleaning, the adhesion of the film formed thereafter is improved.

[0064] Then, the Al-based intermediate film 22 is sputtered under specified process conditions. Here, the Al sputtering source works together with the introduction of argon gas (Ar gas), and nitrogen gas (N2 gas) is introduced into the film forming chamber as a free radical source. It should be noted that Ar gas can also be introduced into the free radical source instead of the sputtering source or together with the sputtering source. The Ar gas can also be a substance of a rare gas other than Ar. Such a change of the Ar gas can also be appropriately performed in other film formations.

[0065] Alternatively, the intermediate film 22 made of an Al-based material such as Al 2 O 3 may be formed by vapor deposition.

[0066] In the vapor deposition of the Al-based intermediate film 22 made of Al, Al particles may be heated by electron beams (EB) in a vacuum film forming chamber.

[0067] In the vapor deposition of the Al-based intermediate film 22 made of Al 2 O 3 , O 2 gas may be introduced into the film forming chamber in a vacuum state to heat the Al particles by EB.

[0068] like Figure 3 As shown in (C), the substrate 2 with the Al-based production intermediate film 22, that is, the production intermediate 20, is immersed in the solution SL in the tank T.

[0069] The solution SL is a solution of a small amount of SiO2 (silicon dioxide) dissolved in water (H2O), in other words, a small amount of silicon dioxide in water.

[0070] In this way, Figure 3 As shown in (D), the Al-based intermediate film 22 changes into the Al2O3 layer 12, while generating the SiO2 layer 14 having a fine concavo-convex structure on the side opposite to the substrate 2. That is, the Al-based intermediate film 22 becomes the Al2O3 layer 12 and the SiO2 layer 14.

[0071] In more detail, the Al-based intermediate film 22 changes into the Al2O3 layer 12 by reacting with partial dissolution of water in the solution SL, while gradually absorbing a trace amount of SiO2 in the solution SL on the side opposite to the substrate 2, and aggregates into a fine concave-convex structure. The Al-based intermediate film 22 grows a plurality of fine villi, pyramids, cones, needles, etc. made of SiO2 in the solution SL along the film thickness direction. It should be noted that the posture (orientation) of the intermediate body 20 during immersion is not limited to Figure 3 The horizontal posture shown. In addition, the number of the production intermediates 20 to be immersed simultaneously may be more than one.

[0072] Mainly from the viewpoint of forming the SiO 2 layer 14 more effectively, the concentration of SiO 2 in the solution SL is, for example, 10 mg / l (milligrams per liter) or less, and further, 2 mg / l or less.

[0073] From the perspective of obtaining a villi-like structure in the shortest possible time, the temperature of the solution SL is 90° C. The temperature of the solution SL is, for example, 80° C. to 100° C., or 90° C. to 100° C. To achieve a temperature of 100° C. or higher, special treatment such as pressurizing water or using treatment other than water is necessary, which is laborious.

[0074] In addition, from the perspective of obtaining the Al2O3 layer 12 and the SiO2 layer 14 in the shortest possible time, the immersion time in the solution SL is, for example, 2 seconds to 10 minutes, or 5 seconds to 5 minutes, or 15 seconds to 3 minutes. When the immersion time is short, the Al2O3 layer 12 and the SiO2 layer 14 cannot be fully obtained, and when the immersion time is long, the processing time becomes longer and the efficiency becomes worse accordingly.

[0075] Afterwards, if Figure 3 As shown in (E), the substrate 2 with the Al2O3 layer 12 and the SiO2 layer 14 is taken out from the groove T and dried, thereby Figure 3 The optical product 1 is completed as shown in (F).

[0076] Example

[0077] Next, preferred embodiments of the present invention and comparative examples not belonging to the present invention are described.

[0078] It should be noted that the present invention is not limited to the following Examples. In addition, depending on how the present invention is understood, the following Examples may actually be Comparative Examples, and the following Comparative Examples may actually be Examples.

[0079] [Example 1]

[0080] 《Manufacturing etc. of Example 1》

[0081] Example 1 corresponds to the above-mentioned embodiment.

[0082] In Example 1, the Al-based intermediate film 22 made of AlN was formed on both surfaces of the PC plate-like substrate 2 with a physical film thickness of 72 nm by DC sputtering under the process conditions shown in the top row except for the row of item names in Table 1 below.

[0083] Then, the production intermediate 20 was immersed in a solution SL containing 0.06 mg / l of silica at 90° C. for 3 minutes and dried to obtain Example 1 of the optical product 1 .

[0084] In particular, the silica concentration of the solution SL is determined as follows. That is, the silica concentration of the solution SL is measured using PACKTEST silica (low concentration) manufactured by Kyoritsu RIKEN Co., Ltd. based on the blue color development principle of molybdenum blue absorption spectroscopy. The PACKTEST silica (low concentration) is capable of measuring the silica concentration in a sample within a range of 0.5 to 20 mg / l. When the silica concentration is lower than 0.5 mg / l, the solvent (H2O) of the solution SL separated as the sample is concentrated by heating and evaporation, and the volume reduction of the concentrated solution is measured, and the silica concentration of the concentrated solution is also measured. For this measured concentration, the silica concentration of the solution SL of the sample before concentration is determined by calculation taking into account the volume reduction of the solvent.

[0085]

Table 1

[0086]

[0087] 《Characteristics of Example 1, etc.》

[0088] Figure 4 This is a graph showing the single-surface reflectance of light in the visible light region and the adjacent region incident perpendicularly to the film-forming surface F of the substrate 2 of Example 1 (incident angle θ=0°).

[0089] Figure 5 It is a graph of the transmittance of light in the visible light region and adjacent regions perpendicular to the film-forming surface F of the substrate 2 of Example 1 (the ratio of the intensity of the transmitted light I2 passing through the optical film 4 on the surface, the substrate 2, and the optical film 4 on the back to the intensity of the incident light I1).

[0090] As can be seen from these graphs, in Example 1, low reflection with respect to visible light (for example, 1% or less in the entire visible light region) is achieved.

[0091] Figure 6It is a graph of the two-surface reflectance of light in the visible light region and the adjacent region (mainly the ratio of the total intensity of reflected light R1 and R2 to the intensity of incident light I1) when the incident angle θ on the film-forming surface F of the substrate 2 of Example 1 is changed in various ways.

[0092] in addition, Figure 7 This is a graph showing the incidence angle dependence of the two-side reflectance, with the horizontal axis being the incident angle θ and the vertical axis being the average value (average reflectance) of the reflectance of a specific region in the visible light region. Here, the specific region is between 420 nm and 680 nm. Below, all the various average reflectances are calculated in the specific region.

[0093] As can be seen from these graphs, in Example 1, low reflection is achieved to the same extent as vertical incidence (e.g., 2% or less in the entire visible light region) up to an incident angle of θ = 45°, and low reflection is also achieved at an average reflectance of 2% or less in the visible light region at an incident angle of θ = 50°. That is, low reflection in Example 1 is achieved at a wide range of incident angles θ (characteristics of moth eyes), and the incident angle dependency of low reflection in Example 1 can be said to be low in the range of 0° to 50°.

[0094] Furthermore, the structure and components of the optical film 4 in Example 1 were observed in the following manner.

[0095] That is, an optical film 4 was produced on one side of a PC substrate by the same production method as in Example 1, and cut into a size that can be placed in a copper sample holder by using a Ga (gallium) beam (FIB (focused ion beam) processing). In addition, in order to place the substrate with the optical film 4 in the sample holder and preserve the structure of the optical film 4, a carbon protective film was covered on the cut substrate with the optical film 4 to prepare an observation object.

[0096] The observation object is observed with a transmission electron microscope (TEM), and elemental analysis of the optical film 4 is performed by irradiating the observation object with characteristic X-rays.

[0097] Figure 8 It is a graph of the spectrum of characteristic X-rays.

[0098] Depend on Figure 8 It can be seen that the observed objects include C (carbon atom), O (oxygen atom), Cu (copper), Ga (gallium), Al (aluminum atom), and Si (silicon atom).

[0099] Among these, Cu comes from the sample holder. In addition, Ga comes from FIB processing. In addition, C comes from the protective film. Thus, the optical film 4 contains O, Al, and Si.

[0100] Fig. 9 This is a TEM observation image. Fig.10 is for Fig. 9 An image (C-Kα ray overlap image) is formed in which the concentration of a pixel becomes higher in proportion to the intensity at the position of the pixel, based on the intensity distribution of the C Kα ray. Fig.11 It is about the Kα ray of O and Fig.10 The same picture (O-Kα ray overlap image). Fig.12 It is about Al's Kα rays and Fig.10 Same picture (Al-Kα ray overlap image). Fig.13 It is about Si's Kα rays and Fig.10 Same picture (Si-Kα ray overlap image).

[0101] According to these figures, there is a layer on the substrate (occupying the horizontally long rectangular portion at the bottom of the image), and there is a fine concavo-convex structure on the layer. In addition, it can be seen that C exists in the portion other than the substrate, the layer, and the fine concavo-convex structure (equivalent to the protective film). In addition, it can be seen that O exists in the layer and the fine concavo-convex structure. In addition, it can be seen that Al exists in the layer on the substrate. In addition, it can be seen that Si exists in the fine concavo-convex structure.

[0102] Furthermore, if the above observations are appropriately compared, it can be seen that the main component of the layer on the substrate is Al oxide, and the main component of the fine concavo-convex structure is Si oxide. In addition, if other observations such as their stability are considered, it can be said that the main component of the layer on the substrate is Al2O3, and the main component of the fine concavo-convex structure is SiO2.

[0103] In addition, if the observation results of Examples 2 to 38 described below are properly considered, it can be said that due to differences in various manufacturing conditions such as the material and film thickness of the Al-based intermediate film 22, the temperature of the solution SL, etc., the Al2O3 layer on the substrate (the layer on the substrate side) and the SiO2 layer with a fine concave-convex structure (the concave-convex layer) are sometimes clearly separated as two layers, and sometimes are not strictly divided into two layers, and the composition gradually changes depending on the position in the film thickness direction (the direction perpendicular to the film).

[0104] In the latter case, the boundaries of various films are sometimes unclear. In addition, in this case, typically, in the layer on the substrate side, the closer to the substrate, the higher the composition ratio of Al2O3, and the farther away from the substrate, the higher the composition ratio of SiO2 to Al2O3. That is, in the film thickness direction, the composition ratio of SiO2 to Al2O3 is proportional to the distance from the substrate.

[0105] In addition, the concavoconvex layer may contain Al2O3 in a state where it is not a main component. For example, the concavoconvex layer may have a core (skeleton) of a fine concavoconvex structure with Al2O3 as a main component and a covering layer with SiO2 as a main component covering part or all of the core.

[0106] [Examples 2 to 37 and Comparative Example 1]

[0107] 《Manufacturing of Examples 2 to 37, etc.》

[0108] Examples 2 to 37 and Comparative Example 1 were respectively manufactured in the same manner as Example 1. However, as shown in Tables 2 to 9 below, in Examples 2 to 37 and Comparative Example 1, at least one of the silica concentration of the solution SL, the material of the Al-based intermediate film 22, the material of the substrate 2, the temperature of the solution SL, and the physical film thickness of the Al-based intermediate film 22 was different from that in Example 1.

[0109] The Al-based intermediate films 22 of Examples 2 to 37 and Comparative Example 1 were all formed by DC sputtering, and their process conditions were classified according to the various materials of the Al-based intermediate films 22, as shown in Table 1. It should be noted that in Table 1, the process conditions during evaporation are also shown as a modified example.

[0110]

Table 2

[0111] Example 1 Example 2 Example 3 Example 4 Example 5 Silica concentration (mg / L) 0.06 0.06 0.06 0.06 0.06 Al-based interlayer materials AlN AlN AlN AlN AlN Substrate material PC PC PC PC PC Solution temperature (℃) 90 95 95 95 90 Al-based intermediate film thickness (nm) 75 78.5 58.6 44.8 105.4 Average reflectivity (%) 0.5 1.31 1.38 1.43

[0112]

Table 3

[0113] Example 6 Example 7 Example 8 Example 9 Example 10 Silica concentration (mg / L) 0.06 0.06 0.06 0.06 0.06 Al-based interlayer materials AlN AlN AlN AlN AlN Substrate material PC PC PC PC PC Solution temperature (℃) 90 90 90 90 85 Al-based intermediate film thickness (nm) 90.85 78.5 58.5 44.8 78.51 Average reflectivity (%) 0.87 0.43 1.27 1.33 0.36

[0114]

Table 4

[0115] Embodiment 11 Example 12 Embodiment 13 Embodiment 14 Embodiment 15 Silica concentration (mg / L) 0.06 0.06 0.06 0.06 0.06 Al-based interlayer materials AlN AlN AlN AlN AlN Substrate material PC PC PC PC PC Solution temperature (℃) 85 85 80 80 80 Al-based intermediate film thickness (nm) 58.5 44.8 105.4 90.85 78.51 Average reflectivity (%) 1.35 1.33 1.7 1.11 0.43

[0116]

Table 5

[0117] Example 16 Embodiment 17 Embodiment 18 Embodiment 19 Embodiment 20 Silica concentration (mg / L) 0.06 0.06 0.06 0.06 0.06 Al-based interlayer materials AlN AlN AlN AlN AlN Substrate material PC PC PC PC PC Solution temperature (℃) 80 80 75 75 75 Al-based intermediate film thickness (nm) 58.5 44.8 78.5 58.5 44.82 Average reflectivity (%) 1.7 1.33 1.87 1.94 1.33

[0118]

Table 6

[0119] Embodiment 21 Embodiment 22 Embodiment 23 Embodiment 24 Embodiment 25 Silica concentration (mg / L) 0.06 0.06 0.06 0.06 0.06 Al-based interlayer materials AlN AlN <![CDATA[Al2O3]]> <![CDATA[Al2O3]]> <![CDATA[Al2O3]]> Substrate material Whiteboard Glass Whiteboard Glass Whiteboard Glass Whiteboard Glass Whiteboard Glass Solution temperature (℃) 90 90 90 98 90 Al-based intermediate film thickness (nm) 48 80 64 133 133 Average reflectivity (%) 0.046 0.21 1.04 0.45 1.79

[0120]

Table 7

[0121] Embodiment 26 Embodiment 27 Embodiment 28 Embodiment 29 Embodiment 30 Silica concentration (mg / L) 0.06 0.06 0.06 0.06 0.06 Al-based interlayer materials <![CDATA[Al2O3]]> <![CDATA[Al2O3]]> <![CDATA[Al2O3]]> Al <![CDATA[Al2O3]]> Substrate material Whiteboard Glass Whiteboard Glass Whiteboard Glass Whiteboard Glass PC Solution temperature (℃) 95 95 90 90 90 Al-based intermediate film thickness (nm) 133 198 198 10 74 Average reflectivity (%) 0.55 0.38 0.35 1.69 1.08

[0122]

Table 8

[0123] Embodiment 31 Embodiment 32 Embodiment 33 Embodiment 34 Embodiment 35 Silica concentration (mg / L) 0.06 0.003 0.06 0.5 1 Al-based interlayer materials <![CDATA[Al2O3]]> AlN AlN AlN AlN Substrate material PC PC PC PC PC Solution temperature (℃) 80 90 90 90 90 Al-based intermediate film thickness (nm) 75 78.5 78.5 78.5 78.5 Average reflectivity (%) 3.82 0.27 0.41 0.5 0.75

[0124]

Table 9

[0125] Embodiment 36 Embodiment 37 Comparative Example 1 Silica concentration (mg / L) 2 10 20 Al-based interlayer materials AlN AlN AlN Substrate material PC PC PC Solution temperature (℃) 90 90 90 Al-based intermediate film thickness (nm) 78.5 78.5 78.5 Average reflectivity (%) 1.35 4.38 9.82

[0126] 《Characteristics of Examples 2 to 37 and Comparative Example 1, etc.》

[0127] Fig.14This is a graph of single-surface reflectance when light in the visible light region and the adjacent region is perpendicularly incident in Examples 2 to 6. Fig.15 is the same as in Examples 7 to 11 Fig.14 Same picture. Fig.16 is the same as in Examples 12 to 16 Fig.14 Same picture. Fig.17 is the same as in Examples 17 to 20 Fig.14 Same picture. Fig.18 is the same as in Examples 21 to 26 Fig.14 Same picture. Fig.19 is the same as in Examples 27 to 31 Fig.14 Same picture. Fig. 20 Examples 32 to 37 and Comparative Example 1 Fig.14 Same picture.

[0128] In addition, the lowest row of each of Tables 2 to 9 shows the respective average reflectances.

[0129] As can be seen from these graphs and tables, in Comparative Example 1, the average reflectance exceeded 9% and approached 10%, and it is difficult to say that the suppression of reflection of visible light is sufficient.

[0130] On the other hand, it can be seen that in Examples 2 to 37, low reflection of visible light is achieved similarly to Example 1.

[0131] Furthermore, it was confirmed through various observations that in Examples 2 to 37, low reflection was achieved in a state with low incident angle dependence as in Example 1, and the fine concave-convex structure was made of SiO2 (a layer whose main component was SiO2), and further a layer made of Al2O3 (a layer whose main component was Al2O3) existed between the fine concave-convex structure and the substrate.

[0132] In particular, when the Al-based intermediate film 22 is AlN, the antireflection optical film 4 was formed at various physical film thicknesses of the Al-based intermediate film 22 and temperatures of the solution SL (Examples 1 to 20).

[0133] In addition, even when the Al-based intermediate film 22 is Al 2 O 3 (Examples 23 to 28, 30 to 31) or Al (Example 29), the antireflection optical film 4 is formed.

[0134] Furthermore, even when the substrate was a white plate glass, the antireflection optical film 4 was formed (Examples 21 to 29).

[0135] <<Temperature of the solution, etc. · Examples 2, 7, 10, 15, 18>>

[0136] By comparing the above Examples 2, 7, 10, 15, and 18, it is found that the characteristic changes caused by the temperature change of the solution SL.

[0137] Examples 2, 7, 10, 15, and 18 are common in the silicon dioxide concentration (0.06 mg / l), the material of the Al-based intermediate film 22 (AlN), the substrate material (PC), and the physical film thickness of the Al-based intermediate film 22 (78.5 to 78.51 nm), but are different from each other in the temperature of the solution SL, which are 95, 90, 85, 80, and 75°C, respectively.

[0138] Fig.21 It is a graph of the single-surface reflectivity at vertical incidence in Examples 2, 7, 10, 15, and 18.

[0139] Fig. 22 It is a graph of the average reflectance in Examples 2, 7, 10, 15, and 18.

[0140] As can be seen from these figures, when the temperature of the solution SL is 80° C. or higher, the single-side reflectance can be further reduced compared to when the temperature is lower than 80° C. (Example 18).

[0141] 《Silicon dioxide concentration of solution, etc.·Examples 32 to 37, Comparative Example 1》

[0142] By comparing Examples 32 to 37 and Comparative Example 1, it was found that the characteristics changed due to the change in the silica concentration of the solution SL.

[0143] Examples 32 to 37 and Comparative Example 1 are common in the material of the Al-based intermediate film 22 (AlN), the substrate material (PC), the temperature of the solution SL (90°C), and the physical film thickness (78.5nm) of the Al-based intermediate film 22. However, they are different from each other in the silica concentration of the solution SL, which are 0.003, 0.06, 0.5, 1, 2, 10, and 20 mg / l, respectively.

[0144] The silica concentration of the solution SL is adjusted by directly using extremely pure water (Example 32) or pure water of normal purity (Example 33), or by adding an appropriate amount of silica gel to the latter pure water and then stirring it thoroughly. In the former pure water and the latter pure water, a trace amount of silica is not completely eliminated and remains.

[0145] It should be noted that the silica concentration was determined as described in the description of Example 1.

[0146] Above Fig. 20 Examples 32 to 37 and Comparative Example 1 are just shown.

[0147] Fig.23It is a graph showing the relationship between the average reflectance (vertical axis) in Examples 32 to 37 and Comparative Example 1 and the silica concentration (horizontal axis) in the solution SL.

[0148] Table 10 is a table showing the relationship between the silica concentration of the solution SL in Examples 32 to 37 and Comparative Example 1 and the average reflectance.

[0149]

Table 10

[0150] Silica concentration (mg / L) 0.003 0.06 0.5 1 2 10 20 420-680nm average reflectivity (%) 0.36 0.33 0.4 0.52 0.75 3.46 15.63

[0151] According to these figures and tables, when the silica concentration of the solution SL is 10 mg / l or less, the single-side reflectivity can be further reduced compared to when it exceeds 10 mg / l (Comparative Example 1). In addition, when the silica concentration of the solution SL is 2 mg / l or less, the single-side reflectivity can be further reduced compared to when it exceeds 2 mg / l (Example 37, Comparative Example 1).

[0152] Note that, in Comparative Example 1, no change occurred in the Al-based intermediate film 22 in the solution SL, and the Al-based intermediate film 22 remained a layered AlN.

[0153] In addition, unlike the above-mentioned examples and comparative examples, as a reference example, the Al-based intermediate film 22 similar to Examples 32 to 37 and Comparative Example 1 (excluding the silica concentration of the solution SL) was immersed in tap water in which the solution SL was heated to 90° C. for 3 minutes. In this reference example, similar to Comparative Example 1, the reflectivity suppression effect was not exerted, and no change occurred in the Al-based intermediate film 22. The silica concentration of the tap water was 20 mg / l.

[0154] Summary, etc.

[0155] Examples 1 to 37 include a substrate 2 (substrate) and an optical film 4 directly formed on its film-forming surface F, the optical film 4 comprising: an Al2O3 layer 12, which is a layer made of Al2O3 and arranged on the side of the substrate 2; and a SiO2 layer 14, which is a layer made of SiO2 having a fine concave-convex structure; or include a substrate 2 (substrate) and an optical film 4 directly formed on its film-forming surface F, the optical film 4 comprising: an Al2O3 layer 12, which is a layer whose main component is Al2O3 and arranged on the side of the substrate 2; and a SiO2 layer 14, which is a layer whose main component is SiO2 having a fine concave-convex structure.

[0156] Thus, a substrate 2 (optical product 1) with an optical film 4 that exhibits an antireflection effect with low incidence angle dependency is provided.

[0157] The manufacturing method of Examples 1 to 37 comprises: a step of forming an Al-based intermediate film 22, which is aluminum, an aluminum alloy, or an aluminum compound, on a substrate 2 (substrate); and a step of immersing the substrate 2 with the Al-based intermediate film 22 in an aqueous solution of silicon dioxide (solution SL), wherein the concentration of silicon dioxide in the solution SL is 10 mg / l or less, which is different from Comparative Example 1 (20 mg / l). Thus, an optical product 1 having an optical film 4 having a fine concavo-convex structure made of SiO2 and exhibiting an antireflection effect in a state with low incidence angle dependence is obtained.

[0158] In the manufacturing methods of Examples 1 to 17 and 21 to 37, the solution SL (aqueous solution) is 80° C. to 100° C. In the manufacturing methods of Examples 1 to 37, the Al-based intermediate film 22 is at least one of Al, Al2O3, AlN and AlON. Thus, an optical product 1 having an optical film 4 exhibiting a better antireflection effect can be obtained.

[0159] Explanation of symbols

[0160] 1··Optical product, 2··Substrate, 12··Al2O3 layer, 14··SiO2 layer, 22··Al-based intermediate film, F··Film-forming surface, SL··Solution (aqueous solution).

Claims

1. A method for manufacturing an optical product, characterized in that: have: A step of forming an Al-based intermediate film, which is aluminum, an aluminum alloy, or an aluminum compound, on a substrate, wherein the film is formed by a dry process such as vacuum evaporation or sputtering; A step of dissolving a trace amount of silicon dioxide in water to obtain a silicon dioxide aqueous solution having a silicon dioxide concentration of 10 mg / l or less, and making the silicon dioxide aqueous solution 80° C. to 98° C. or 75° C.; and The step of immersing the substrate with the Al-based intermediate film in the silica aqueous solution for a period of 2 seconds to 10 minutes, During the immersion of the substrate with the Al-based interlayer film in the silica aqueous solution, the Al-based interlayer film changes into an optical film. The optical film has: An Al2O3 layer, which is a layer disposed on the substrate side and in which Al2O3 accounts for more than half by volume; and The SiO2 layer is a layer having a fine concavoconvex structure and in which SiO2 accounts for more than half of the volume ratio, The fine concavo-convex structure is formed by the adsorption of SiO2 on the Al2O3 layer transformed from the Al-based intermediate film.

2. The method for manufacturing an optical product according to claim 1, wherein: The Al-based intermediate film is at least any one of Al, Al2O3, AlN and AlON.

3. The method for manufacturing an optical product according to claim 1, wherein: The fine concavo-convex structure is at least any one of an irregular villi-like structure, an irregular pyramid group-like structure and an irregular flower socket-like structure.

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