Optical product, manufacturing method of optical product, and production intermediate film

Abstract

To provide an optical product suppressing generation of cracks irrespective of fine rugged structure and having high antireflection performance, an optical product manufacturing method capable of producing the optical product easily, and a production intermediate film used for the manufacturing method.SOLUTION: A manufacturing method of an optical product 1 includes: a production intermediate film formation step (Fig. 3(B)) of depositing a production intermediate film 22 with three or more layers on a base material 2; and an immersion step (Fig. 3(D)) of immersing the base material 2 with the production intermediate film 22 (production intermediate 20) into aqueous solution of silica at 80°C or higher and lower than 100°C. A first layer counted from the base material 2 in the production intermediate film 22 is an Al2O3 layer 31 made of Al2O3. A second layer in the production intermediate film 22 is an AlN layer 32 made of AlN. A third layer in the production intermediate film 22 is an Al2O3 layer 33 made of Al2O3. The first layer (Al2O3 layer 31) in the production intermediate film 22 has a physical film thickness of 7 nm or more and 25 nm or less.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an optical product having a film with fine irregularities formed thereon, a method for manufacturing an optical product, and a manufacturing intermediate film that can be used in the manufacturing method. [Background technology]

[0002] Patent Document 1 (Japanese Patent No. 7055494) describes a method for manufacturing an optical product, which is a substrate with a film having a fine uneven structure (moth eye), by immersing a substrate with an Al-based intermediate film in a specified silica aqueous solution. The density of such a fine uneven structure decreases from the substrate side to the air side. Therefore, the refractive index of the film gradually changes. Therefore, the film acts to eliminate optical interfaces or to act like a thin film with a low refractive index. Due to these effects, the film exhibits an anti-reflection effect and can be used as an anti-reflection film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7055494 Summary of the Invention [Problem to be solved by the invention]

[0004] There is room for further reduction in the likelihood of cracks occurring in the optical products described above. Furthermore, there is room for further improvement in the anti-reflection performance of the above-mentioned optical products.

[0005] Therefore, the main object of the present disclosure is to provide an optical product that has a fine uneven structure while further suppressing the occurrence of cracks, as well as a manufacturing method for an optical product that can easily produce such an optical product, and a manufacturing intermediate film that can be used in the manufacturing method. Furthermore, another main object of the present disclosure is to provide an optical product having a fine uneven structure with higher anti-reflection performance, a manufacturing method for an optical product that can easily produce such an optical product, and a manufacturing intermediate film that can be used in the manufacturing method. [Means for solving the problem]

[0006] This specification discloses a method for manufacturing an optical product. The optical product may include a substrate. The optical product may include an optical film disposed on a coating surface of the substrate and having a fine uneven structure. The optical film may be formed by immersing a substrate with a manufactured interlayer film having three or more layers in an aqueous silica solution at 80°C or higher and lower than 100°C. The first layer of the manufactured interlayer film, counting from the substrate side, may be an Al2O3 layer made of Al2O3. The second layer of the manufactured interlayer film may be an AlN layer made of AlN. The third layer of the manufactured interlayer film may be an Al2O3 layer made of Al2O3. The physical film thickness of the first layer of the manufactured interlayer film may be 7 nm or higher and 25 nm or lower.

[0007] This specification further discloses a first method for manufacturing an optical product. This method for manufacturing an optical product may include a manufacturing interlayer formation step of forming a manufacturing interlayer having three or more layers on a substrate. The method for manufacturing an optical product may include an immersion step of immersing the substrate with the manufacturing interlayer in an aqueous silica solution at 80°C or higher and lower than 100°C. The first layer of the manufacturing interlayer, counting from the substrate side, may be an Al2O3 layer made of Al2O3. The second layer of the manufacturing interlayer may be an AlN layer made of AlN. The third layer of the manufacturing interlayer may be an Al2O3 layer made of Al2O3. The physical film thickness of the first layer of the manufacturing interlayer may be 7 nm or higher and 25 nm or lower. This specification also discloses a second method for manufacturing an optical product. This method for manufacturing an optical product may include a first manufacturing interlayer layer forming step of forming an Al2O3 layer made of Al2O3 as a first layer of the manufacturing interlayer on the coating surface of the substrate, with a physical film thickness of 7 nm or more and 25 nm or less. The method for manufacturing an optical product may also include a second manufacturing interlayer layer forming step of forming an AlN layer made of AlN as a second layer of the manufacturing interlayer on the first Al2O3 layer. The method for manufacturing an optical product may also include a third manufacturing interlayer layer forming step of forming an Al2O3 layer made of Al2O3 as a third layer of the manufacturing interlayer on the second AlN layer. The method for manufacturing an optical product may also include an immersion step of immersing the substrate with the manufacturing interlayer in an aqueous silica solution at 80°C or more and less than 100°C.

[0008] In addition, this specification discloses a manufactured interlayer film. This manufactured interlayer film may be used to manufacture an optical film having a fine relief structure on a substrate. The manufactured interlayer film may have three or more layers. The first layer, counting from the substrate side, may be an Al2O3 layer made of Al2O3. The second layer may be an AlN layer made of AlN. The third layer may be an Al2O3 layer made of Al2O3. The physical film thickness of the first layer may be 7 nm or more and 25 nm or less. [Effects of the Invention]

[0009] The main effect of the present disclosure is to provide an optical product that has a fine uneven structure while further suppressing the occurrence of cracks, as well as a manufacturing method for an optical product that can easily produce such an optical product, and a manufacturing intermediate film that can be used in the manufacturing method. Furthermore, another main effect of the present disclosure is to provide an optical product having a fine uneven structure with higher anti-reflection performance, as well as a manufacturing method for an optical product that can easily produce such an optical product, and a manufacturing intermediate film that can be used in the manufacturing method. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of an optical product according to the present invention. [Figure 2]2 is a schematic cross-sectional view of an intermediate product in the manufacture of the optical product of FIG. 1. FIG. [Figure 3] 3(A) to 3(F) are schematic diagrams relating to a method for manufacturing the optical product of FIG. [Figure 4] FIG. 2 is a schematic top view of a manufacturing apparatus for a manufacturing intermediate product. [Figure 5] 5 is a flowchart of an example of operation of the manufacturing apparatus of FIG. 4. [Figure 6] 10 is a flowchart showing the details of step S5. [Figure 7] 1 is a graph showing the reflection spectrum of the single-side reflectance of perpendicularly incident light in Examples 1 to 5. [Figure 8] 10 is a graph showing the reflection spectrum of the single-side reflectance of perpendicularly incident light in Examples 6 to 8. [Figure 9] 10 is a graph showing the reflection spectrum of the single-side reflectance of perpendicularly incident light in Examples 9 to 11. [Figure 10] 10 is a graph showing the reflection spectrum of the single-side reflectance of perpendicularly incident light in Examples 12 and 13. [Figure 11] 1 is a graph showing the reflection spectra of the single-side reflectance of perpendicularly incident light in Comparative Examples 1 to 3. [Figure 12] 10 is a graph showing the reflection spectra of the single-side reflectance of perpendicularly incident light in Comparative Examples 4 to 6. [Figure 13] 10 is a graph showing the reflection spectra of the single-side reflectance of perpendicularly incident light in Comparative Examples 7 to 9. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, examples of embodiments according to the present disclosure will be described with reference to the accompanying drawings as appropriate. It should be noted that the present disclosure is not limited to the following examples.

[0012] As shown in FIG. 1, an optical product 1 manufactured by the manufacturing method of the present disclosure includes a substrate 2 and an optical film 4 formed on a film-forming surface F of the substrate 2. The optical product 1 is used as a light-transmitting anti-reflection member. That is, in the optical product 1, the optical film 4 suppresses the intensity of the reflected light R relative to the intensity of the incident light I (incident angle θ) on the optical product 1. The optical product 1 may be used for purposes other than anti-reflection members.

[0013] The substrate 2 is the base of the optical product 1 and is in the form of a plate in this case. The plate-shaped substrate 2 is a substrate. The substrate 2 is translucent. The transmittance of the substrate 2 for visible light, which is light having wavelengths in the visible range, is nearly 100%. The visible range here is from 420 nm (nanometers) to 680 nm. The shape of the substrate 2 may be a flat plate, a curved plate, or a shape other than a plate, such as a block. The visible range may also be other wavelength ranges. For example, the lower limit of the visible range may be any of 380, 390, 400, 410, 430, and 440 nm. The lower limit of the visible range may also be any of 650, 700, 720, 740, 760, 780, and 800 nm.

[0014] The base material 2 is made of, for example, plastic, and more specifically, a thermosetting resin such as polycarbonate resin (PC). The material of the substrate 2 is not limited to PC, but may 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. Furthermore, the material of the substrate 2 may be glass or other materials other than plastic.

[0015] The film-forming surface F of the substrate 2 is disposed on one surface, and the optical film 4 is provided directly on the film-forming surface F. The optical film 4 may be provided on both the first and second surfaces of a plate-shaped substrate 2, or on three or more surfaces of a block-shaped substrate 2, for example. An intermediate film such as a hard coat film may be provided between the optical film 4 and the substrate 2. The intermediate film may be a single-layer film having one layer, or a multilayer film having multiple layers. When such an intermediate film is provided, the optical film 4 is indirectly formed on the substrate 2.

[0016] The optical film 4 has a fine uneven structure 5. The unevenness is oriented in the direction of the film thickness. The density of the optical film 4 decreases from the substrate 2 side to the surface side. The substrate 2 side can be regarded as the film formation surface F side or the bottom side. The surface side can be regarded as the air side or the top side. The main components of the elements in the optical film 4 are Al, Si, and O. The main components here are those in which the combined amount of Al, Si, and O constitutes the majority in terms of element ratio relative to other components, and may be those that constitute the majority in terms of weight ratio or volume ratio. Such matters regarding the main components also apply appropriately to components other than the optical film 4. The element ratios of Al, Si, and O are different in the surface, middle, and lower portions of the optical film 4. The surface portion of the optical film 4 can be regarded as the air side portion, the tip side portion of the fine uneven structure 5, or the upper portion. The lower portion of the optical film 4 can be regarded as the film formation surface F side portion, or the base side portion of the fine uneven structure 5.

[0017] The thickness of the optical film 4, i.e., the height of the fine uneven structure 5, in other words, the size in the film thickness direction, is, for example, about 1 nm to 1000 nm, i.e., on the nano-size order, preferably 1 nm to 400 nm, and more preferably 5 nm to 300 nm. If the height of the fine uneven structure 5 is shorter than the wavelength of visible light, the scattering of visible light in the optical film 4 is reduced, and the optical film 4 becomes transparent. Furthermore, a certain thickness makes it easier to manufacture the optical film 4. The fine uneven structure 5 in the optical film 4 is, for example, a fluffy structure, a pyramid-group structure, a pinholder-like structure, or a combination thereof.

[0018] The optical product 1 is produced from a production intermediate 20 shown in Fig. 2. The production intermediate 20 comprises a substrate 2 and a production intermediate film 22 formed on a film-forming surface F. The manufactured intermediate film 22 is a multilayer film having three or more layers, and in Figure 2, a multilayer film with a total of three layers is shown. Each layer is an aluminum alloy or an aluminum compound. The intermediate film 22 is Al-based. The aluminum alloy may be an alloy containing aluminum as the main component. The aluminum compound may be a compound containing aluminum as the main component. The main component here may be a component that accounts for the majority by weight, volume, or elemental ratio relative to other components.

[0019] More preferably, the layer closest to the substrate 2 is the first layer, and the material of the first layer is Al2O3 (aluminum oxide), a type of aluminum compound. The first layer is an Al2O3 layer 31 made of Al2O3. The physical film thickness of the first Al2O3 layer 31 is preferably 7 nm or more and 25 nm or less, from the viewpoint of suppressing the occurrence of cracks in the optical film 4 after manufacture. The cracks may be fine. The fine cracks may include cloudiness. The material of the second layer is AlN (aluminum nitride), a type of aluminum compound. The second layer is an AlN layer 32 made of AlN. The element ratio of Al to N in aluminum nitride may be any ratio as long as it is stable. The second layer is adjacent to the first layer on the air side. The layer numbers are counted from the substrate 2 side to the air side. In addition, the material of the third layer is Al2O3. The third layer is an Al2O3 layer 33 made of Al2O3. Furthermore, a fourth layer or more may be provided. In this case, the material of the fourth layer or more may be AlN or Al2O3. The manufactured intermediate film 22 may be an alternating film of Al2O3 and AlN. Furthermore, when there are multiple manufactured intermediate films 22, the material of some of the manufactured intermediate films 22 may be different from the material of the other manufactured intermediate films 22.

[0020] Fig. 3 is a schematic diagram of a method for manufacturing the optical product of Fig. 1. In Fig. 3, the physical thickness of the optical film 4 is exaggerated relative to the physical thickness of the substrate 2. As shown in FIG. 3(B), a fabricated intermediate film 22 is formed on the film formation surface F of the substrate 2 shown in FIG. 3(A) (fabricated intermediate film formation process). The fabricated intermediate film 22 is formed directly on the substrate 2 by physical vapor deposition (PVD) or atomic layer deposition. Examples of physical vapor deposition include vacuum deposition and sputtering. If the fabricated intermediate film 22 is formed on both sides of the substrate 2, an optical film 4 is formed on both sides of the substrate 2.

[0021] The manner in which the intermediate film 22 is formed by DC sputtering in the DC sputtering film-forming apparatus 101 will be described below.

[0022] FIG. 4 is a schematic top view of the DC sputtering film formation apparatus 101. As shown in FIG. The DC sputtering film-forming apparatus 101 is a drum-type sputtering film-forming apparatus (carousel-type sputtering apparatus) and forms a production intermediate film 22 on a film-forming surface F of the substrate 2. The DC sputtering film formation apparatus 101 includes a vacuum chamber 102 as a film formation chamber, and a cylindrical drum 104 arranged in the center of the vacuum chamber 102 so as to be rotatable about its own axis. A substrate 2 as a film formation target is held on the outer cylindrical surface of the drum 104 with a film formation surface F facing outward.

[0023] A sputtering source 110 is disposed on one side of the vacuum chamber 102 . The sputtering source 110 includes a sputtering cathode 112 on which a target T is set, a pair of adhesion prevention plates 114, and a sputtering gas inlet 116 through which a sputtering gas is introduced with its flow rate appropriately adjusted. The sputtering cathode 112 is connected to an external DC power supply (not shown). The shield plate 114 is arranged to separate the target T and the portion of the drum 104 facing it from the rest of the interior of the vacuum chamber 102 . The sputtering gas inlet 116 flows the sputtering gas toward the space partitioned by the deposition shield 114 . It should be noted that one or more other sputtering sources (second sputtering source, third sputtering source, etc.) may be arranged on another side of the vacuum chamber 102. The second sputtering source, etc., may be equipped with a sputtering cathode on which a target is set, a pair of adhesion prevention plates, and a sputtering gas inlet, similar to the sputtering source 110.

[0024] Furthermore, a radical source 130 is disposed on the other side of the vacuum chamber 102 . The radical source 130 has a radical gas inlet 134 through which gas can be introduced after adjusting the flow rate using a valve 132, and a gun 136 that can generate plasma by applying voltage from an acceleration voltage power supply (not shown) and discharging. The discharge from the gun 136 is, for example, a high frequency discharge, preferably an RF (Radio Frequency) discharge. The gas introduced into the vacuum chamber 102 from the radical gas inlet 134 is radicalized by the plasma generated by the gun 136. As the substrate 2 on the drum 104 passes through this plasma, at least one of reaction and modification occurs on the film formation surface F, etc.

[0025] In addition, exhaust units 140 are provided on both sides of the radical source 130. Each exhaust unit 140 evacuates the inside of the vacuum chamber 102. The arrangement and number of at least one of the sputtering source 110, the radical source 130, and each exhaust section 140 are not limited to those described above. The current (voltage) in at least one of the sputtering source 110 and the radical source 130 may be a direct current, or a low-frequency or high-frequency alternating current.

[0026] Next, an example of the operation of the DC sputtering film formation apparatus 101, that is, an example of a method for manufacturing the intermediate film 22, will be described mainly with reference to FIG.

[0027] First, the substrate 2 is set on the drum 104, and a plate-shaped target T made of Al is also set on the drum 104 (step S1). Next, the inside of the vacuum chamber 102 is evacuated (step S2). Next, the drum 104 is rotated, and the substrate 2 held by the drum 104 is made to pass through the inside of the sputtering source 110 and the radical source 130 in sequence and repeatedly at high speed (step S3). Next, the substrate 2 is cleaned (step S4). That is, with oxygen (O2) gas being introduced from the radical gas inlet 34 of the radical source 130, a high-frequency voltage is applied to the gun 136 to generate radical oxygen, which is then irradiated onto the moving substrate 2 for a predetermined time. By irradiating the radical oxygen in this way, even if organic matter or the like is attached to the surface of the substrate 2, the organic matter or the like is decomposed and removed by the radical oxygen and ultraviolet light generated by the plasma, and the film-forming surface F of the substrate 2, etc. is cleaned. This cleaning improves the adhesion of the film to be formed later.

[0028] Subsequently, the intermediate film 22 is formed by sputtering under predetermined process conditions (step S5). FIG. 6 is a flowchart showing the details of step S5.

[0029] For example, the first Al2O3 layer 31 of the manufactured intermediate film 22 is formed as follows (step S11, manufactured intermediate film first layer formation process): That is, while the drum 104 continues to rotate, a rare gas and oxygen (O2) gas are introduced from the sputtering gas inlet 116 of the sputtering source 110, and a DC voltage is applied to the sputtering cathode 112. Discharge caused by application of a DC voltage to the sputtering cathode 112 is called DC discharge. Sputtering caused by DC discharge is called DC sputtering. The Al on the surface of the target T is sputtered out as one or more Al atoms by O2 sputtering, and these Al atoms are oxidized and deposited on the surface of the substrate 2, resulting in an Al2O3 layer 31. The rare gas is, for example, argon (Ar) gas. When O2 gas is introduced during DC discharge, the O2 becomes radicals and becomes active. Therefore, the Al2O3 layer 31 becomes a thin film made of a compound of Al and O (Al2O3). The degree of oxidation of Al can be adjusted by process conditions, etc. Sputtering that involves a reaction such as oxidation is called reactive sputtering.

[0030] Alternatively, the Al2O3 layer 31 can be formed by introducing a rare gas through the sputtering gas inlet 116 of the sputtering source 110, applying a DC voltage to the sputtering cathode 112, and operating the radical source 130 while the drum 104 continues to rotate. This type of sputtering is called the Radical Assist Sputtering method, or RAS method. The radical source 130 is operated by applying a high-frequency voltage to the gun 136 while O2 gas is introduced through the radical gas inlet 134. This operation generates oxygen radicals. When the substrate 2 passes a portion adjacent to the sputtering source 110, Al is deposited on the substrate 2, and when the substrate 2 passes a portion adjacent to the radical source 130, Al on the substrate 2 is oxidized. By repeating the deposition and oxidation of Al in this manner, a thin film made of AlO is formed on the substrate 2. Note that a rare gas may be introduced into the radical source 130 together with the O gas.

[0031] Next, the second AlN layer 32 of the intermediate film 22 is formed as follows (step S12, intermediate film second layer forming step). That is, while the drum 104 is kept rotating, a rare gas and nitrogen (N2) gas are introduced from the sputtering gas inlet 116 of the sputtering source 110, and a DC voltage is applied to the sputtering cathode 112. When N2 gas is introduced during DC discharge, N2 becomes radicals and becomes active. Therefore, the AlN layer 32 is formed by reactive sputtering, forming a compound of Al and N (AlN x; It becomes a thin film made when 0 < x < 1). The value of x can be adjusted according to process conditions and the like. The AlN layer 32 is formed on the first Al2O3 layer 31. In addition, the AlN layer 32 may be formed by the RAS method.

[0032] Subsequently, the third Al2O3 layer of the manufacturing intermediate film 22 is formed in the same manner as the first Al2O3 layer 31 (step S13, third-layer formation step of the manufacturing intermediate film). The Al2O3 layer 33 is formed on the second AlN layer 32. In addition, the formation methods of Al2O3 may be different between the first Al2O3 layer 31 and the third Al2O3 layer 33. Also, the fourth layer and subsequent layers may be formed by appropriately repeating the above.

[0033] The film thickness of each layer in the manufacturing intermediate film 22 is adjusted according to the length of the film formation time (discharge time) in view of other process conditions. That is, when the input power to the sputter cathode 112 is constant and the film formation rate, which is the physical film thickness formed per unit time, is constant, the film thickness of the manufacturing intermediate film 22 is controlled by the length of the sputtering time. Therefore, when the time corresponding to the desired film thickness has elapsed, the voltage application to the sputter cathodes 112 and 122 and the gun 136 is stopped, and the film formation of each layer is completed. Preferably, the first Al2O3 layer 31 is formed with a physical film thickness within the range of 7 nm or more and 25 nm or less.

[0034] When the formation of the manufacturing intermediate film 22 as a multilayer film is completed, the drum 104 is stopped, appropriately cooled, and then the substrate 2 with the manufacturing intermediate film 22 is taken out (step S6). In addition, one or more intermediate films may be further provided between the manufacturing intermediate film 22 and the substrate 2 by the DC sputter film formation apparatus 101 or another apparatus.

[0035] Also, one or more layers in the manufacturing intermediate film 22 may be formed by vapor deposition. In the deposition, Al granules may be heated by an electron beam (EB) in a vacuum deposition chamber, and N2 gas or the like may be introduced into the vacuum deposition chamber.

[0036] The substrate 2 with the intermediate film 22 thus formed, that is, the intermediate product 20, is immersed in the solution SL in the tank B (immersion step), as shown in FIG. 3(C). The solvent of the solution SL is, for example, water (H2O). The solution SL is preferably pure water. 3(D), the manufactured intermediate film 22 generates the optical film 4 having the fine concave-convex structure 5. That is, the manufactured intermediate film 22 becomes the optical film 4. More specifically, the intermediate film 22 is formed by growing a large number of Al-based fine fluffs, pyramids, cones, needle-like bodies, etc. in the film thickness direction in the solution SL. The posture (orientation) of the intermediate film 20 during immersion is not limited to the horizontal posture shown in Fig. 3. A plurality of intermediate films 20 may be immersed at the same time. The temperature of the solution SL is 80°C or higher here from the viewpoint of obtaining a fluffy structure or the like in as short a time as possible. The transformation of the production intermediate film 22 into a fluffy structure or the like occurs in the solution SL at 80°C or higher. The temperature of the solution SL is, for example, 80°C or higher but lower than 100°C, or 80°C or higher but lower than 99°C, or 80°C or higher but lower than 98°C, or 80°C or higher but lower than 90°C. To achieve a temperature of 100°C or higher, special treatment such as pressurization must be applied to the water, or a substance other than water must be used, which is time-consuming. 100°C can be considered the boiling temperature. Temperatures below 100°C can be considered below the boiling temperature. The temperature of the solution SL may be lower than 80°C, provided that a solution SL at 80°C or higher is applied to the production intermediate 20 at some stage. Furthermore, from the viewpoint of obtaining the optical film 4 in as short a time as possible, the immersion time in the solution SL is, for example, from 2 seconds to 20 minutes, or from 5 seconds to 10 minutes, or from 15 seconds to 5 minutes, or from 1 minute to 3 minutes. If the immersion time is too short, the optical film 4 cannot be obtained satisfactorily. On the other hand, if the immersion time is too long, the processing time becomes long and the efficiency decreases accordingly.

[0037] Furthermore, the solution SL is a solution in which a trace amount of SiO2 (silica) is dissolved in water (H2O), or in other words, an aqueous solution of a trace amount of silica. In highly pure water or water of normal purity, a trace amount of silica remains without being completely eliminated. Then, the manufacturing intermediate film 22 becomes a fine concavo-convex structure 5 of the Al-based and Si-based types. That is, the manufacturing intermediate film 22 incorporates silica and becomes the optical film 4, and the material of the optical film 4 is AlO y (0 < y < 1.5) and SiO z (0 < z < 2) mixture. More specifically, the manufacturing intermediate film 22 gradually adsorbs a trace amount of SiO2 on the side opposite to the base material 2 while changing to the Al-based type by a reaction involving partial dissolution in water in the solution SL, and collects it so as to have the fine concavo-convex structure 5. In the solution SL, the manufacturing intermediate film 22 grows a large number of fine fluff, pyramids, cones, needle-like bodies, etc. related to the above mixture in the film thickness direction. Since the concentration of SiO2 in the solution SL becomes difficult to be incorporated into the optical film 4 if it is too high, for example, it is 10 mg / l (milligrams per liter) or less, and further 2 mg / l or less.

[0038] Thereafter, as shown in FIG. 3(E), the base material 2 with the optical film 4 is taken out from the tank B and dried, so that the optical product 1 is completed as shown in FIG. 3(F). The drying is performed, for example, by blowing warm air at 80°C. By blowing warm air, drying is performed faster than in the case of natural drying. In cases where quality is emphasized over efficiency, natural drying may be performed. The temperature of the warm air may be 60°C or higher and 100°C or lower, or 70°C or higher and 90°C or lower. Also, drying may be omitted. 3(C) to 3(E) may be repeated multiple times. In this case, some tanks B (e.g., the temperature of the solution SL) may be different from others. Furthermore, the drying step in FIG. 3(E) may be omitted as appropriate. For example, a first tank, a second tank, and a third tank may be provided, each with a solution SL temperature of 60, 80, and 90°C, respectively. The manufacturing intermediate 20 may be immersed in the first tank, the second tank, the third tank, the second tank, and the first tank, respectively, for a predetermined time, and then dried after five immersions. Multiple tanks with the same solution SL temperature may also be provided. In this way, the temperature of the solution SL applied to the manufacturing intermediate 20 may be gradually increased toward 80°C or higher, which is necessary for the transformation into a fluffy structure, for example, by applying a solution SL at 60°C before applying a solution SL at 80°C. This reduces thermal shock and improves the quality of the optical film 4. Even if the temperature of the solution SL is gradually decreased, the thermal shock is also reduced and the quality of the optical film 4 is improved. The stepwise increase and decrease in the temperature of the solution SL may be omitted, or at least one of them may be performed, or both may be performed. The process of immersing in a solution SL below 80°C before immersing in a solution SL at 80°C or higher is a pre-immersion process. Furthermore, the process of immersing in a solution SL below 80°C after immersing in a solution SL at 80°C or higher is a post-immersion process. The solvent or dissolved substance in at least one of the pre-immersion process and the post-immersion process may be different from that in the immersion process, but from the viewpoint of minimizing the influence on other tanks, it is preferably the same aqueous silica solution as in the immersion process.

[0039] The optical product 1 is formed by immersing a substrate 2 with a manufactured intermediate film 22 having three or more layers in an aqueous solution of silica at a temperature of 80°C or higher but lower than 100°C. The configuration of optical product 1 may be considered to be specified by the manufacturing method related to its formation, but even if this is the case, it is considered that such specification is permissible due to the existence of so-called impossible or impractical circumstances. That is, the fine uneven structure 5 generated by such formation varies microscopically each time, even if the adjustable manufacturing conditions, such as the configuration of the manufactured intermediate film 22 and the temperature of the solution SL, are consistent. Furthermore, differences in structure or characteristics from other optical films having fine uneven structures cannot be identified by a general concept. Therefore, it is not practical to directly identify an optical product 1 having an optical film 4 having a fine uneven structure 5 by its structure or characteristics. Furthermore, in order to analyze an optical film 4 having a fine uneven structure 5, it is necessary to preserve the fine uneven structure 5 so that it can withstand analysis, and then use an extremely expensive analytical machine for a long time.Furthermore, since the characteristics of the fine uneven structure 5 vary each time, it is necessary to use many analytical machines, and it is considered that exploring the structure of the optical product 1 requires a great deal of equipment and time and is almost impossible or impractical. Therefore, even if the optical product 1 is considered to be specified by the manufacturing method related to the above formation, such specification should be permitted. [Example]

[0040] Next, examples of the present disclosure and comparative examples not belonging to the present disclosure will be described. The present disclosure is not limited to the following examples. Depending on how the present disclosure is interpreted, the following examples may essentially be comparative examples, and vice versa.

[0041] Examples 1 to 5 relating to the manufacturing method of the optical product 1 were carried out as follows, using the manufactured intermediate films 22 shown at the top of Table 1 below. The numerical values ​​in Tables 1 to 3 indicate physical film thicknesses. The units of the physical film thicknesses are nm. That is, a total of three layers of intermediate film 22 were formed on one surface of substrate 2 by sputtering. Substrate 2 in Examples 1 to 5 was a square flat plate with each side measuring 5 cm (centimeters). The material of substrate 2 in Examples 1 to 5 was PC. Substrate 2 in Examples 1 to 5 was NF-2000 manufactured by Mitsubishi Gas Chemical Company, Inc. The first and third layers of the manufactured intermediate film 22 are Al2O3 layers 31 and 33. In forming the Al2O3 layers 31 and 33, the target T is Al, and power is supplied to the sputtering source 110 and the radical source 130, and gas is supplied from the sputtering source 110 and the radical source 130. The film formation rate of the Al2O3 layers 31 and 33 at this time was 0.25 nm / sec (nanometers per second). The second layer of the production intermediate film 22 is an AlN layer 32. In forming the AlN layer 32, the target T is Al, and power is supplied to the sputtering source 110 and the radical source 130, and gas is supplied from the sputtering source 110 and the radical source 130. The film formation rate of the AlN layer 32 at this time was 0.25 nm / sec.

[0042] Next, the substrate 2 with the intermediate film 22, i.e., the intermediate film 20, was immersed in pure water at 90°C for 10 minutes. The conductivity of the pure water was 1 μS / m (microsiemens per meter) and the silica concentration was 2 mg / L or less. By immersing in this pure water, the intermediate film 22 was transformed into the optical film 4. Subsequently, the substrate 2 with the optical film 4 attached thereto was dried with hot air at 80° C. for 5 minutes.

[0043] [Table 1]

[0044] Examples 6 to 8 were carried out as follows using the manufactured interlayer film 22 shown in the upper center of Table 1. That is, a total of five layers of intermediate films 22 were formed by sputtering on one surface of the same substrate 2 as in Examples 1 to 5. The first, third and fifth layers of the manufactured intermediate film 22 are Al2O3 layers. The deposition of these layers is similar to the deposition of the Al2O3 layers in Examples 1 to 5 described above. The second and fourth layers of the intermediate film 22 are AlN layers. The deposition of these layers is similar to the deposition of the AlN layers in Examples 1 to 5 described above. The fourth AlN layer is formed on the third Al2O3 layer 31 (a manufacturing intermediate film fourth layer forming step). The fifth Al2O3 layer is formed on the fourth AlN layer (a manufacturing intermediate film fifth layer forming step). Thereafter, the production intermediate 20 was immersed and dried in the same manner as in Examples 1-5.

[0045] Examples 9 to 11 were carried out as follows using the manufactured interlayer film 22 shown in the lower center of Table 1. That is, a total of three layers of intermediate films 22 were formed by sputtering on one surface of the same substrate 2 as in Examples 1 to 5. The Al2O3 layers 31 and 33 as the first and third layers of the manufactured intermediate film 22 were formed in the same manner as the Al2O3 layers in Examples 1 to 5 described above. The AlN layer 32, which is the second layer of the intermediate film 22, is formed in the same manner as the AlN layer in Examples 1 to 5 described above. Thereafter, the production intermediate 20 was immersed and dried in the same manner as in Examples 1-5.

[0046] Examples 12 and 13 were carried out as follows using the manufactured interlayer film 22 shown at the bottom of Table 1. That is, different from Examples 1 to 11, a total of three layers of intermediate films 22 were formed by sputtering on one surface of the substrate 2. The material of the substrate 2 in Example 12 is a cyclic olefin copolymer (COC), APL5014DP manufactured by Mitsui Chemicals, Inc. The material of the substrate 2 in Example 13 is polyimide. The Al2O3 layers 31 and 33 as the first and third layers of the manufactured intermediate film 22 were formed in the same manner as the Al2O3 layers in Examples 1 to 5 described above. The AlN layer 32, which is the second layer of the intermediate film 22, is formed in the same manner as the AlN layer in Examples 1 to 5 described above. Thereafter, the production intermediate 20 was immersed and dried in the same manner as in Examples 1-5.

[0047] The physical film thickness of the first Al2O3 layer 31 in the manufactured intermediate film 22 in Examples 1 to 13 was in the range of 7 nm to 25 nm.

[0048] On the other hand, Comparative Examples 1 to 3 relating to the manufacturing method of an optical product were carried out as follows, using the manufacturing intermediate films shown in Table 2 below. The substrate 2 in all Comparative Examples was the same as in Examples 1 to 13. The Al2O3 layer and AlN layer were formed in all Comparative Examples in the same manner as in Examples 1 to 13. Furthermore, the immersion and drying of the manufacturing intermediate 20 in all Comparative Examples was the same as in Examples 1 to 13. The intermediate films manufactured in Comparative Examples 1 to 3 each had a total of two layers: the first layer was an AlN layer, and the second layer was an Al2O3 layer.

[0049] [Table 2]

[0050] Comparative Examples 4 to 8 were carried out in the same manner as Comparative Examples 1 to 3, using the interlayer films produced as shown at the top of Table 3 below. The intermediate films manufactured in Comparative Examples 4 to 8 have a total of three layers. The first and third layers are Al2O3 layers. The second layer is an AlN layer. The physical film thickness of the first layer in the intermediate films manufactured in Comparative Examples 4 to 8 is outside the range of 7 nm to 25 nm.

[0051] [Table 3]

[0052] Comparative Example 9 was carried out in the same manner as Comparative Examples 1 to 3, using the interlayer film manufactured as shown at the bottom of Table 3 below. The intermediate film manufactured in Comparative Example 9 has a total of five layers. The first, third, and fifth layers are Al2O3 layers. The second and fourth layers are AlN layers. The physical film thickness of the first layer in the intermediate film manufactured in Comparative Example 9 is not within the range of 7 nm or more and 25 nm or less.

[0053] Fig. 7 is a graph of the reflection spectra of the single-sided reflectance of light in the visible range and adjacent ranges incident at an incident angle θ = 0°, i.e., perpendicularly, to the film-forming surface F of the substrate 2 in Examples 1 to 5. As mentioned above, the visible range is 420 nm to 680 nm. Fig. 8 is a graph showing the reflection spectra of the single-sided reflectance of perpendicularly incident light in Examples 6 to 8. Fig. 9 is a graph showing the reflection spectra of the single-sided reflectance of perpendicularly incident light in Examples 9 to 11. Fig. 10 is a graph showing the reflection spectra of the single-sided reflectance of perpendicularly incident light in Examples 12 and 13. Fig. 11 is a graph showing the reflection spectra of the single-sided reflectance for perpendicularly incident light in Comparative Examples 1 to 3. Fig. 12 is a graph showing the reflection spectra of the single-sided reflectance for perpendicularly incident light in Comparative Examples 4 to 6. Fig. 13 is a graph showing the reflection spectra of the single-sided reflectance for perpendicularly incident light in Comparative Examples 7 to 9. Table 4 below shows whether cracks occurred after formation and the average reflectance (%) in the visible range for Examples 1 to 13. Table 5 below shows whether cracks occurred after formation and the average reflectance (%) in the visible range for Comparative Examples 1 to 9.

[0054] [Table 4]

[0055] [Table 5]

[0056] According to these graphs and tables, cracks were present and crack occurrence was observed in Comparative Examples 1 to 8. The physical film thickness of the first layer of the manufactured intermediate film 22 in Comparative Examples 4 to 5 and 7 to 8 was less than 7 nm. The physical film thickness of the first layer of the manufactured intermediate film 22 in Comparative Example 6 exceeded 25 nm. On the other hand, in Comparative Example 9 and Examples 1 to 13, no cracks occurred in the optical films 4 formed. Such crack suppression is due to the fact that the manufactured intermediate film 22 is a multilayer film. Also, this suppression is due to the fact that the first layer of the manufactured intermediate film 22 is an Al2O3 layer 31. Furthermore, this suppression is due to the fact that the physical film thickness of the first layer of the manufactured intermediate film 22 is 7 nm or more and 25 nm or less.

[0057] Here, one of the mechanisms by which cracks are suppressed by the manufactured intermediate film 22, which is a multilayer film, is understood to be as follows. That is, the reactions of the Al2O3 layers 31, 33 and the AlN layer 32 in the solution SL, which is an aqueous solution of a trace amount of silica, are expressed by the following formulas (1), (2-1) and (2-2). 2AlN+3H2O→Al2O3+2NH3 (1) Al2O3+3H2O→2Al(OH)3··(2-1) 2Al(OH)3→Al2O3+3H2O ···(2-2)

[0058] The reaction of formula (1) is an exothermic reaction, and the reactions of formulas (2-1) and (2-2) are endothermic reactions. Because the manufacturing intermediate film 22 includes the Al2O3 layers 31, 33 and the AlN layer 32, the magnitude of heat generation or absorption due to the reaction in the solution SL is suppressed within a predetermined range. This suppresses the influence of heat during film formation on the film formation surface F and adjacent portions of the substrate 2. This suppresses expansion or contraction of the film formation surface F during film formation, thereby suppressing cracks in the optical film 4. For example, if the endothermic reactions of formulas (2-1) and (2-2) are excessive, excessive heat absorption occurs on the deposition surface F and adjacent portions of the substrate 2, causing the deposition surface F to shrink. When the optical coating 4 is deposited in this state and then dried or otherwise processed to alleviate or remove the excessive heat absorption, the contracted deposition surface F expands to return to its original shape, exerting a force on the optical coating 4. This force can cause cracks. To prevent cracks from occurring due to this mechanism, it is sufficient to eliminate excessive heat absorption, i.e., to include the exothermic reaction of formula (1). Therefore, the presence of the AlN layer 32, which is the basis for the reaction of formula (1), in addition to the AlO layers 31 and 33, which are the basis for the reactions of formulas (2-1) and (2-2), in the manufactured intermediate film 22, is effective in preventing cracks in the optical coating 4 to be deposited.

[0059] Furthermore, the formation of the optical film 4 based on the above-described multilayer manufacturing intermediate film 22 more appropriately forms the base portion, which is the portion that serves as the base of the fine concave-convex structure 5. The base portion is at least one of the root portion and the portion below the root of the fine concave-convex structure 5, and can also be considered as a continuous portion. For example, when the physical film thickness of the first layer of the manufactured interlayer film 22 is less than 7 nm, as in Comparative Examples 4, 5, and 7, and 8, the strength of the base portion of the optical film 4 is insufficient to suppress cracking. Furthermore, when the physical film thickness of the first layer of the manufactured interlayer film 22 exceeds 25 nm, as in Comparative Example 6, relatively strong stress occurs in the base portion. The action of such stress is prevented by the support of the base portion by the substrate 2; however, when the support by the substrate 2 reaches a limit, cracks occur in order to relieve the stress. In particular, in relation to the plastic substrate 2, the stress of the optical film 4 and the stress of the plastic substrate 2 tend to be in opposite directions. Therefore, suppressing the physical film thickness of the first layer of the manufactured interlayer film 22 in order to thin the base portion of the optical film 4 may be a key point. In Comparative Example 9, although the physical film thickness of the first Al2O3 layer 31 of the manufactured intermediate film 22 is 30 nm, the manufactured intermediate film 22 has a total of five layers, and the physical film thicknesses of the second to fifth layers are each relatively small, so it is believed that cracks are suppressed. Among Examples 1 to 13, Examples 3 and 8 had the smallest physical film thickness of the first layer of the manufactured interlayer film 22 (physical film thickness: 7 nm), and no cracks occurred in them. Furthermore, among Examples 1 to 13, Example 5 had the largest physical film thickness of the first layer of the manufactured interlayer film 22 (physical film thickness: 25 nm), and no cracks occurred in them either. Furthermore, in Examples 12 and 13, in which the material of the substrate 2 was other than PC, no cracks occurred in the optical film 4.

[0060] Moreover, the average reflectance in the visible region in Comparative Examples 6 and 9 exceeds 1%. In Comparative Examples 6 and 9, the physical film thickness of the first Al2O3 layer 31 of the manufactured intermediate film 22 was relatively large at 30 nm, and it is thought that the physical film thickness of the base portion of the optical film 4 was correspondingly large, resulting in an average reflectance in the visible range exceeding 1%. On the other hand, in Comparative Examples 1 to 5, 7 to 8 and Examples 1 to 13, the average reflectance in the visible range of the formed optical film 4 is 1% or less. Such suppression of the average reflectance is due to the fact that the manufactured intermediate film 22 is a multilayer film. Also, this suppression is due to the fact that the first layer of the manufactured intermediate film 22 is an Al2O3 layer 31. Furthermore, this suppression is due to the fact that the physical film thickness of the first layer of the manufactured intermediate film 22 is 25 nm or less.

[0061] Due to these factors, the base portion, which is the base of the fine uneven structure 5, is formed more appropriately in terms of reflectance. For example, if the physical film thickness of the first layer of the intermediate film 22 exceeds 25 nm, the film thickness of the base portion may become excessive in terms of suppressing the reflectance. Among Examples 1 to 13, Example 5 had the largest physical film thickness of the first layer of the manufactured intermediate film 22 (physical film thickness: 25 nm), and its average visible reflectance was 0.89%, which was 1% or less. Furthermore, in Examples 12 and 13, in which the material of the substrate 2 was other than PC, the average visible reflectance was also 1% or less.

[0062] Furthermore, the optical film 4 corresponding to Example 1 was analyzed using a microscope or the like, and the following was found. That is, formation of the optical film 4 having the fine concavo-convex structure 5 on the base material 2 is recognized. And the base part which is the lower part of the optical film 4 is layered. The lower part of the optical film 4 is composed of a mixture of AlO y (0 < y < 1.5) and SiO z (0 < z < 2). Also, at the central part of the optical film 4, corresponding to the root part of the convex part in the fine concavo-convex structure 5, the main component of the central part of the optical film 4 is AlO y (0 < y < 1.5), and the other component of the central part of the optical film 4 is SiO z (0 < z < 2). Furthermore, at the upper part of the optical film 4, corresponding to the tip part of the convex part in the fine concavo-convex structure 5, it is composed of a mixture of AlO y (0 < y < 1.5) and SiO z (0 < z < 2). Thus, Si which does not exist in the production intermediate film 22 exists in the optical film 4. This Si is derived from the silica taken in during dipping.

[0063] In addition, due to differences in various production conditions such as the material and film thickness of the production intermediate film 22 and the temperature of the solution SL, at least any two of the upper part, central part, and lower part of the optical film 4 may be clearly separated, or may not be strictly separated. For example, the components may gradually change according to the position in the film thickness direction (the direction perpendicular to the film). In the latter case, the boundaries of various parts may be unclear. Also, in this case, typically, the component ratio of Al2O3 is high in the intermediate part, and the component ratio of SiO2 to Al2O3 increases in the upper and lower parts. Furthermore, the convex part etc. may have a core (framework) of the fine concavo-convex structure 5 mainly composed of Al2O3 and a coat mainly composed of SiO2 covering part or all of the core.

[0064] Hereinafter, Examples 1 to 13 related to the manufacturing method of the optical product 1, the optical films 4 formed in Examples 1 to 13, and the production intermediate films 22 used in Examples 1 to 13 are summarized. The optical products 1 according to Examples 1 to 13 include a substrate 2 and an optical film 4 disposed on a coating surface F of the substrate 2 and having a fine relief structure 5. The optical film 4 is formed by immersing the substrate 2 with a manufactured intermediate film 22 having three or more layers in a solution SL that is an aqueous silica solution at a temperature of 80°C or higher and lower than 100°C. The first layer of the manufactured intermediate film 22, counting from the substrate 2 side, is an Al2O3 layer 31 made of Al2O3. The second layer of the manufactured intermediate film 22 is an AlN layer 32 made of AlN. The third layer of the manufactured intermediate film 22 is an Al2O3 layer 33 made of Al2O3. The physical film thickness of the Al2O3 layer 31, which is the first layer of the manufactured intermediate film 22, is 7 nm or higher and 25 nm or lower. Therefore, the occurrence of cracks was suppressed in the optical products 1 according to Examples 1 to 13. Furthermore, the average reflectance in the visible range of the optical film 4 of the optical products 1 according to Examples 1 to 13 was 1% or less, and reflection was sufficiently suppressed. In the optical products according to Comparative Examples 1 to 8, in which a manufactured intermediate film not satisfying the above-mentioned conditions was used, cracks occurred in the optical film. Furthermore, in the optical products according to Comparative Examples 6 and 9, in which a manufactured intermediate film not satisfying the above-mentioned conditions was used, the average reflectance in the visible range of the optical film exceeded 1%.

[0065] Examples 1 to 13 include a manufacturing interlayer film forming step (FIGS. 3(B), 4, and 5) of forming a manufactured interlayer film 22 having three or more layers on a substrate 2, and an immersion step (FIG. 3(D)) of immersing the substrate 2 (manufacturing intermediate 20) with the manufactured interlayer film 22 in an aqueous silica solution at 80°C or higher and lower than 100°C. The first layer of the manufactured interlayer film 22, counting from the substrate 2 side, is an Al2O3 layer 31 made of Al2O3. The second layer of the manufactured interlayer film 22 is an AlN layer 32 made of AlN. The third layer of the manufactured interlayer film 22 is an Al2O3 layer 33 made of Al2O3. The physical film thickness of the first layer (Al2O3 layer 31) of the manufactured interlayer film 22 is 7 nm or higher and 25 nm or lower. Furthermore, Examples 1 to 13 include a first intermediate film layer formation process (step S11) for forming an Al2O3 layer 31 made of Al2O3 as the first layer of the intermediate film 22 on the film-forming surface F of the substrate 2 with a physical film thickness of 7 nm or more and 25 nm or less; a second intermediate film layer formation process (step S12) for forming an AlN layer 32 made of AlN as the second layer of the intermediate film 22 on the first Al2O3 layer 31; a third intermediate film layer formation process (step S13) for forming an Al2O3 layer 33 made of Al2O3 as the third layer of the intermediate film 22 on the second AlN layer 32; and an immersion process for immersing the substrate 2 with the intermediate film 22 attached thereto in an aqueous silica solution at a temperature of 80°C or more and less than 100°C. Therefore, in Examples 1 to 13, the occurrence of cracks was suppressed. Furthermore, in Examples 1 to 13, the average reflectance in the visible range of the formed optical film 4 was 1% or less, and reflection was sufficiently suppressed. In Comparative Examples 1 to 8, in which a manufactured interlayer film not satisfying the above conditions was used, cracks occurred in the optical film. Furthermore, in Comparative Examples 6 and 9, in which a manufactured interlayer film not satisfying the above conditions was used, the average reflectance in the visible range of the optical film exceeded 1%.

[0066] Furthermore, in Examples 1 to 13, by immersing the substrate 2 with the manufactured intermediate film 22 in an aqueous solution, the manufactured intermediate film 22 is transformed into an optical film 4, and the optical film 4 has a fine uneven structure 5. Therefore, in Examples 1 to 13, an optical film 4 with sufficiently suppressed reflection is formed. Furthermore, in Examples 1 to 13, the fine uneven structure is at least one of a fluffy structure, a pyramid-group structure, and a pinholder-shaped structure. Therefore, in Examples 1 to 13, the optical film 4 having the fine uneven structure 5 is more easily formed.

[0067] Additionally, in the immersion step of Examples 1 to 13, the substrate 2 with the manufactured interlayer film 22 is immersed for 10 minutes, which is within the range of 2 seconds to 20 minutes, thereby making it possible to more easily and efficiently form the optical film 4 having the fine relief structure 5. Furthermore, in Examples 1 to 13, the substrate 2 is made of plastic. Therefore, the optical film 4 with low reflectance is formed on the substrate 2 having stress in a state where the occurrence of cracks is suppressed.

[0068] Furthermore, in Examples 6 to 8, the manufactured intermediate film 22 has five or more layers. The fourth layer in the manufactured intermediate film 22 is an AlN layer made of AlN. The fifth layer in the manufactured intermediate film 22 is an AlO layer made of AlO. Therefore, the optical film 4 is formed in a state in which crack generation and reflection are sufficiently suppressed. Furthermore, Examples 6 to 8 include a fourth intermediate film layer forming step of forming an AlN layer made of AlN as the fourth layer of the intermediate film 22 on the third AlO layer, and a fifth intermediate film layer forming step of forming an AlO layer made of AlO on the fourth AlN layer as the fifth layer of the intermediate film, thereby forming the optical film 4 in a state where crack generation and reflection are sufficiently suppressed.

[0069] In addition, the manufactured intermediate film 22 used in Examples 1 to 13 has three or more layers. In the manufactured intermediate film 22, the first layer counting from the substrate 2 side is an Al2O3 layer 31 made of Al2O3. In the manufactured intermediate film 22, the second layer is an AlN layer 32 made of AlN. In the manufactured intermediate film 22, the third layer is an Al2O3 layer 33 made of Al2O3. The physical film thickness of the first layer, the Al2O3 layer 31, is 7 nm or more and 25 nm or less. Therefore, the manufactured intermediate films 22 according to Examples 1 to 13 can be used to form an optical film 4 in which the occurrence of cracks is suppressed, and contribute to facilitating the formation of the optical film 4. Furthermore, the manufactured intermediate films 22 according to Examples 1 to 13 can be used to form an optical film 4 in which reflection is sufficiently suppressed, and contribute to facilitating the formation of the optical film 4. [Explanation of symbols]

[0070] 1.Optical products 2...Base material 4...Optical film 5. Fine uneven structure 22·Manufacturing interlayer film 31, 33··Al2O3 layer 32··AlN layer F··Film-forming surface SL··Solution (aqueous solution)

Claims

1. A substrate; an optical film disposed on the film-forming surface of the substrate and having a fine uneven structure; It is equipped with the optical film is formed by immersing the substrate with a manufactured intermediate film having three or more layers in an aqueous silica solution at a temperature of 80°C or higher and lower than 100°C; In the manufactured intermediate film, the first layer counting from the substrate side is Al ２ O ３ Made of Al ２ O ３ layer, the second layer in the manufactured intermediate film is an AlN layer made of AlN, The third layer in the intermediate film is Al ２ O ３ Made of Al ２ O ３ layer, The physical film thickness of the first layer in the manufactured intermediate film is 7 nm or more and 25 nm or less. An optical product characterized by:

2. a manufactured interlayer film forming step of forming a manufactured interlayer film having three or more layers on a substrate; an immersion step of immersing the substrate with the manufactured interlayer film in an aqueous silica solution at a temperature of 80°C or higher and lower than 100°C; It is equipped with In the manufactured intermediate film, the first layer counting from the substrate side is Al ２ O ３ Made of Al ２ O ３ layer, the second layer in the manufactured intermediate film is an AlN layer made of AlN, The third layer in the intermediate film is Al ２ O ３ Made of Al ２ O ３ layer, The physical film thickness of the first layer in the manufactured intermediate film is 7 nm or more and 25 nm or less. A method for manufacturing an optical product, comprising:

3. On the film-forming surface of the substrate, Al is applied as the first layer of the intermediate film. ２ O ３ Made of Al ２ O ３ a first intermediate film layer formation step of forming a layer having a physical film thickness of 7 nm or more and 25 nm or less; The first layer of Al ２ O ３ a second intermediate film layer forming step of forming an AlN layer made of AlN on the layer as a second layer of the intermediate film; On the second AlN layer, an AlN layer is formed as a third layer of the intermediate film. ２ O ３ Made of Al ２ O ３ a third intermediate film layer forming step for forming a layer; an immersion step of immersing the substrate with the manufactured interlayer film in an aqueous silica solution at a temperature of 80°C or higher and lower than 100°C; Equipped with A method for manufacturing an optical product, comprising:

4. The substrate with the manufactured intermediate film is immersed in the aqueous solution, whereby the manufactured intermediate film is transformed into an optical film, The optical film has a fine uneven structure.

4. The method for manufacturing an optical product according to claim 2 or 3.

5. The fine uneven structure is at least one of a fluffy structure, a pyramidal structure, and a pinholder-like structure.

5. The method for manufacturing an optical product according to claim 4.

6. In the immersion step, the substrate with the manufactured intermediate film is immersed for 2 seconds to 20 minutes.

4. The method for manufacturing an optical product according to claim 2 or 3.

7. The substrate is made of plastic 4. The method for manufacturing an optical product according to claim 2 or 3.

8. The manufactured interlayer has five or more layers, the fourth layer in the manufacturing intermediate film is an AlN layer made of AlN, The fifth layer in the intermediate film is Al ２ O ３ Made of Al ２ O ３ Layer 3. The method for manufacturing an optical product according to claim 2.

9. Furthermore, the third layer of Al ２ O ３ a fourth intermediate film layer forming step of forming an AlN layer made of AlN on the layer as a fourth layer of the intermediate film; On the fourth AlN layer, an AlN layer is formed as a fifth layer of the intermediate film. ２ O ３ Made of Al ２ O ３ a fifth intermediate film layer forming step of forming a layer; Equipped with 4. The method for manufacturing an optical product according to claim 3.

10. A manufacturing intermediate film used in manufacturing an optical film having a fine uneven structure on a substrate, having three or more layers, The first layer counting from the substrate side is Al ２ O ３ Made of Al ２ O ３ layer, the second layer is an AlN layer made of AlN, The third layer is Al ２ O ３ Made of Al ２ O ３ layer, The physical thickness of the first layer is 7 nm or more and 25 nm or less. A manufactured interlayer film characterized by:

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