Optical products and methods for manufacturing the same

Abstract

To provide an optical product, where the anti-static performance, scratch resistance performance, and anti-reflection performance coexist at a higher level, and provide a manufacturing method for the same.SOLUTION: In an optical product 1, an optical multilayer film 4 is formed directly on one face side of a substrate 2. The optical multilayer film 4 comprises an anti-reflection part 10, and a surface layer part 12 that is located on the most air side. The surface layer part 12 includes an anti-fouling film. The anti-reflection part 10 has a plurality of low refractive index layers L made of low refractive index material, a plurality of high refractive index layers H made of high refractive index material, and an ITO layer 14 made of ITO. The high refractive index material is Si3 N4. The first layer of the anti-reflection part 10 reckoned from the substrate 2 side is a high refractive index layer H. The second layer of the anti-reflection part 10 reckoned from the substrate 2 side is the ITO layer 14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical product having an anti-reflective function that suppresses the reflection of light in a predetermined wavelength range, and to a method for manufacturing the same. [Background technology]

[0002] As a laminate for anti-reflective coatings, the one described in Japanese Patent Publication No. 2005-288712 (Patent Document 1) is known. This laminate comprises an antistatic layer such as ITO (Indium Tin Oxide) and a cured film layer formed by curing a liquid resin composition capable of forming a low refractive index layer and a high refractive index layer in a single coating step. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2005-288712 [Overview of the project] [Problems that the invention aims to solve]

[0004] This laminate has antistatic properties due to the antistatic layer and tear resistance due to the cured film. However, since there is only one low-refractive-index layer and one high-refractive-index layer, only an anti-reflective property of about 95% can be obtained.

[0005] The main objective of this disclosure is to provide an optical product in which antistatic performance, tear resistance (scratch resistance), and anti-reflective performance coexist at a higher level, and a method for manufacturing the same. [Means for solving the problem]

[0006] This specification discloses an optical product. This optical product has an optical multilayer film on at least one side of a substrate, either directly or via an interlayer. The optical multilayer film comprises an anti-reflective layer and a surface layer located on the air side. The surface layer includes an anti-fouling film. The anti-reflective layer has a plurality of low refractive index layers made of a low refractive index material, a plurality of high refractive index layers made of a high refractive index material, and an ITO layer made of ITO. The high refractive index material is Si3N4. The first layer of the anti-reflective layer, counting from the substrate side, is a high refractive index layer. The second layer of the anti-reflective layer, counting from the substrate side, is an ITO layer. Furthermore, this specification discloses a method for manufacturing optical products. In this method for manufacturing optical products, at least one of the high refractive index layer, low refractive index layer, and ITO layer of the optical product described above is formed on one side of a substrate by sputtering, either directly or via an interlayer, thereby forming an anti-reflective portion, and then a surface layer is formed. [Effects of the Invention]

[0007] The main effect of this disclosure is to provide optical products and methods for manufacturing the same in which antistatic performance, scratch resistance, and anti-reflective performance coexist at a higher level. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view of the optical product according to the present invention. [Figure 2] Figure 1 is a schematic top view of the apparatus used to manufacture the optical products. [Figure 3] This is a flowchart illustrating an example of the operation of the device shown in Figure 2. [Figure 4] This graph shows the spectral reflectance distribution in the visible and adjacent regions in Example 1. [Modes for carrying out the invention]

[0009] Examples of embodiments of the present invention will be described below. The present invention is not limited to the following embodiments.

[0010] <<Composition of optical products, etc.>> As shown in FIG. 1, the optical product 1 according to the present invention has a plate-like base material 2 and an optical multilayer film 4 formed directly on one side (film-forming surface M) thereof. Note that the base material 2 may have a shape other than a plate shape, such as a block shape. The film-forming surface M may be a flat surface or a curved surface. A plurality of film-forming surfaces M and optical multilayer films 4 may be provided, for example, on both sides of the base material 2. When a plurality of film-forming surfaces M are provided, they may have different shapes from each other. When a plurality of optical multilayer films 4 are provided, they may have the same (symmetrical with respect to the base material 2) configuration as each other, or may have different configurations from each other. Further, the optical multilayer film 4 may be formed on the film-forming surface M via an intermediate film. When a plurality of optical multilayer films 4 are provided, the intermediate films may have the same mode as each other or different modes from each other when viewed from the base material 2, including whether or not they are present. In the base material 2, the optical multilayer film 4 of the present invention and an optical film (single-layer film or optical multilayer film) not belonging to the present invention may coexist.

[0011] As long as the base material 2 is transparent (appropriately including translucent), it may be made of any material such as a resin (plastic) such as polycarbonate or glass. Preferably, it is glass containing an alkali element, more preferably strengthened glass, for example, chemically strengthened glass. Since the base material 2 made of strengthened glass has a compressive stress layer formed on its surface, even if cracks occur on the surface, the growth of the cracks is suppressed by the compressive stress, and it is more resistant to impact than a base material 2 made of ordinary (not strengthened) glass. Further, the base material 2 is preferably non-windable and preferably non-rollable. As long as the substrate is not flexible enough to be wound up unless plastic deformation occurs, the optical multilayer film 4 and the like are formed more stably, and the optical product 1 becomes more robust.

[0012] The optical multilayer film 4 is formed on the base material 2 (film-forming surface M). The optical multilayer film 4 is formed to exhibit at least an optical function, and here, it is formed to exhibit at least an antireflection function. The optical multilayer film 4 has an anti-reflective portion 10 and a surface layer portion 12. The surface layer portion 12 is formed on top of the anti-reflective portion 10 (on the opposite side from the substrate 2, the air side). The anti-reflective portion 10 may be considered as an anti-reflective film, and the surface layer portion 12 may be considered as a surface film.

[0013] The anti-reflective portion 10 is formed by alternately stacking a low refractive index layer L made of a low refractive index material and a high refractive index layer H made of a high refractive index material. The low refractive index material is silicon dioxide (SiO2). Alternatively, the low refractive index material may also be calcium fluoride (CaF2), magnesium fluoride (MgF2), or a mixture of two or more of these materials containing SiO2. The high refractive index material is silicon nitride (Si3N4). Si3N4 provides a layer with greater hardness compared to other common high refractive index materials, contributing to increased hardness of the optical multilayer film 4 and, consequently, improved scratch resistance. The refractive index of Si3N4 is approximately 1.7, and it can also be considered a medium refractive index material. Since the anti-reflective portion 10 has a Si3N4 layer made of Si3N4 as the high refractive index layer H, it is preferably formed by sputtering.

[0014] Furthermore, the anti-reflective portion 10 has an ITO layer 14 made of conductive ITO in order to provide an antistatic function. Since the refractive index of ITO is approximately 2.1 to 2.2 in the visible range (for example, the wavelength range of 400 nm to 680 nm), the ITO layer 14 can be treated as a high refractive index layer H. The ITO layer 14 is preferably formed by sputtering.

[0015] It can be determined that at least one of the anti-reflective portion 10, namely the high refractive index layer H, the low refractive index layer L, and the ITO layer 14, was formed by sputtering. For example, while it is easy to identify a high refractive index layer H made of Si3N4 formed by sputtering, directly identifying the microstructure of Si3N4 formed by sputtering is impractical, even after thoroughly observing the entire layer with an electron microscope capable of detecting atoms, and direct measurement is extremely difficult even for those skilled in the art. Therefore, it is useful to identify the high refractive index layer H as formed by sputtering, and furthermore, it is useful and easy to understand for those skilled in the art to identify the high refractive index layer H by various conditions during sputtering. The same applies to the low refractive index layer L and the ITO layer 14. Furthermore, when a radical gas (plasma gas) is introduced during sputtering, identifying the high refractive index layer H as a radical-treated (plasma-treated) layer is useful because it is difficult (and not practical) to directly identify the differences in the microstructure of the high refractive index layer H depending on whether or not radical treatment (plasma treatment) is performed. In this case, the high refractive index layer H may be further identified by various conditions, such as the conditions for introducing the radical gas (plasma gas) and the conditions of the deposition chamber. The same applies to the low refractive index layer L and the ITO layer 14.

[0016] Since the anti-reflective portion 10 has an anti-reflective function, it preferably consists of 17 or more layers, including the ITO layer 14. Because the refractive index of Si3N4 is relatively low for a high refractive index material, a relatively large number of layers are required to obtain the desired anti-reflective performance. In the optical multilayer film 4, if the layer closest to the substrate 2 (the layer closest to the substrate 2) is considered the first layer, then the first layer of the anti-reflective portion 10 is the high refractive index layer H. Since the ITO layer 14 is formed on the substrate 2 via the high refractive index layer H, the adhesion of the ITO layer 14 is greater than when the ITO layer 14 is formed directly on the substrate 2. Furthermore, in the anti-reflective section 10, the ITO layer 14 is positioned as the second layer. Although the ITO layer 14 has inferior scratch resistance compared to other layers, it is positioned as close to the substrate 2 as possible, so the ITO layer 14 is protected from external forces, improving the scratch resistance of the optical product 1. Furthermore, in the third layer and above of the antireflection portion 10, the odd-numbered layers are high refractive index layers H, and the even-numbered layers are low refractive index layers L. The outermost layer of the antireflection portion 10 (the layer adjacent to the substrate 2 side in the surface layer portion 12) is a low refractive index layer L. In the antireflection portion 10, except for the ITO layer 14, one type each of a high refractive index material (Si3N4) and a low refractive index material (SiO2) is used, so the film design is easier and the film formation cost is lower.

[0017] The surface layer portion 12 is a film disposed on the air side from the antireflection portion 10 in order to increase the surface slipperiness and impart or improve scratch resistance, and is an antifouling film (water-repellent film, oil-repellent film). In addition, the surface layer portion 12 further imparts an antifouling function to the optical product 1. The surface layer portion 12 is preferably made of an organosilicon compound, and more preferably, is a polycondensate of an organosilicon compound. By polycondensation, the film can be thickened and densified, the adhesion to the antireflection portion 10 and the surface hardness are increased, and in addition to water repellency, oil repellency is also exhibited, and a film excellent in slipperiness is easily obtained. The surface layer portion 12 is formed by a known vapor deposition method or ion sputtering method or the like. When the manufacturing methods of the antireflection portion 10 (preferably sputtering method) and the surface layer portion 12 are different, the surface layer portion 12 is formed after changing the apparatus after the formation of the antireflection portion 10. The organosilicon compound before polycondensation is preferably a compound having a silicon-containing functional group represented by -SiR y X 3-y (R is a monovalent organic group, X is a hydrolyzable group, and y is an integer from to 2). Here, as X, for example, an alkoxy group such as -OCH3, -OCH2CH3, an acyloxy group such as -OCOCH3, -ON=CR a R b and the like, a ketoxime group (R a , R b each represent a monovalent organic group), a halogen group such as -Cl, -Br, -NR c R d and the like, an amino group (R c , R d each represent a monovalent organic group), and the like. Fluorine-containing organosilicon compounds are preferred as such organosilicon compounds. Fluorine-containing organosilicon compounds are comprehensively excellent in water and oil repellency, electrical insulation, mold release properties, solvent resistance, lubricity, heat resistance, and defoaming properties. In particular, relatively large organosilicon compounds with a molecular weight of about 1,000 to 50,000 that have a perfluoroalkyl group or perfluoropolyether group in the molecule exhibit excellent lubricity.

[0018] In the optical product 1 described above, for example, the base material 2 is a lens filter base material, and the optical product is a lens filter. A typical use in this case is to attach it near the lens (in front of, above, etc.) for the purpose of protecting the lens, and a typical example of a lens is a camera lens. Lens filters, compared to eyeglass lenses, have less need for plastic lens substrates. Instead, there is a greater need to flatten the spectral reflectance distribution in the visible range with extremely low reflectance (e.g., less than 1% across the entire range or on average within the range) in order to suppress at least one of the color tinting and light reduction caused by the filter. Optical product 1 described above can be well suited to such needs. Furthermore, in optical products, including lens filters, the addition of at least one of scratch resistance and antistatic properties is desirable for at least one of the following: extending the lifespan while suppressing quality deterioration and improving maintainability by suppressing the adhesion of dust and other particles. The above-mentioned optical product 1 can well meet such needs.

[0019] <<Manufacturing equipment for optical products, etc.>> Next, an embodiment of a manufacturing apparatus capable of producing the optical product 1 described above will be explained. Furthermore, the manufacturing apparatus for the optical product 1 according to the present invention is not limited to the following forms.

[0020] Figure 2 is a schematic top view of the manufacturing apparatus 101 according to the said configuration. The manufacturing apparatus 101 is a drum-type sputtering deposition apparatus (carousel-type sputtering apparatus) that deposits an optical product 1 on one or more plate-shaped substrates 2. The manufacturing apparatus 101 comprises a vacuum chamber 102 as a film deposition chamber, and a cylindrical drum 104 positioned in the center of the vacuum chamber 102 so as to be rotatable around its own axis. A substrate 2, to be deposited on, is held on the outer cylindrical surface of the drum 104 with the film deposition surface M facing outwards.

[0021] A first sputtering source 110 is positioned on one side of the vacuum chamber 102. The first sputtering source 110 includes a sputtering cathode 112 for setting the first target T1, a pair of protective plates 114, and a sputtering gas inlet 116 through which sputtering gas is introduced after appropriate flow rate adjustment. The sputter cathode 112 is connected to an external DC power supply (not shown). The protective plate 114 is positioned to separate the first target T1 from the opposing portion of the drum 104 from the rest of the vacuum chamber 102. The sputtering gas inlet 116 directs the sputtering gas towards the space separated by the protective plate 114.

[0022] A second sputtering source 120 is located on another side of the vacuum chamber 102. The second sputtering source 120, like the first sputtering source 110, includes a sputtering cathode 122 for setting the second target T2, a pair of protective plates 124, and a sputtering gas inlet 126.

[0023] Furthermore, a radical source 130 is positioned on the other side of the vacuum chamber 102. The radical source 130 includes a radical gas inlet 134 into which gas can be introduced after adjusting the flow rate by a valve 132, and a gun 136 into which plasma can be generated when a voltage is applied by an acceleration voltage power supply (not shown). The gas introduced into the vacuum chamber 102 from the radical gas inlet 134 is radicalized by the plasma generated by the gun 136 and irradiated towards the substrate 2 in a beam shape.

[0024] In addition, exhaust units 140 are provided on both sides of the radical source 130. Each exhaust unit 140 is used to evacuate the vacuum chamber 102. Furthermore, the arrangement and number of at least one of the first sputtering source 110, the second sputtering source 120, the radical source 130, and each exhaust unit 140 are not limited to those described above. The current (voltage) in at least one of the first sputtering source 110, the second sputtering source 120, and the radical source 130 may be DC, or it may be AC ​​at low frequency or high frequency (e.g., Radio Frequency; RF).

[0025] An example of the operation of the manufacturing apparatus 101 (an example of a method for manufacturing the optical product 1) will be explained mainly based on Figure 3.

[0026] First, the substrate 2 is set in the drum 104, and silicon (Si) is set as the first target T1, and ITO is set as the second target T2 (step S1). Next, the inside of the vacuum chamber 102 is evacuated (step S2). Next, the drum 104 is rotated so that the substrate 2 held in the drum 104 passes sequentially and repeatedly at high speed inside the first sputtering source 110, the second sputtering source 120, and the radical source 130 (step S3). Next, the substrate 2 is cleaned (step S4). That is, with oxygen (O2) gas 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 such irradiation with radical oxygen, even if organic matter is attached to the surface of the substrate 2, the organic matter is decomposed and peeled off by the radical oxygen and ultraviolet light generated by the plasma, and the surface of the substrate 2 is cleaned. Such cleaning improves the adhesion of the film to be formed later.

[0027] Next, the anti-reflective portion 10 of the optical multilayer film 4 is formed (step S5). Specifically, while the rotation of the drum 104 is maintained, a noble gas (in this case, Ar gas) is introduced from the sputtering gas inlet 116 of the first sputtering source 110, and a direct current (DC) voltage is applied to the sputtering cathode 112, causing the Si on the surface of the first target T1 to be deposited onto the surface of the substrate 2 by sputtering with Ar. Furthermore, with oxygen gas (O2 gas) introduced from the radical gas inlet 134 of the radical source 130, a high-frequency voltage is applied to the gun 136 to generate radical oxygen, which is irradiated onto the moving substrate 2 on which the Si has been deposited, causing oxidation of the Si and forming the low refractive index layer L (SiO2 layer) of the anti-reflective section 10. At this time, the second sputtering source 120 is not operating. Note that a noble gas may be introduced along with the O2 gas. Similarly, while the rotation of the drum 104 is maintained, Si of the first target T1 is deposited onto the substrate 2 by sputtering, and nitrogen gas (N2 gas) is introduced from the radical gas inlet 134 of the radical source 130. A high-frequency voltage is applied to the gun 136 to generate radical nitrogen, which is irradiated onto the moving substrate 2 on which Si has been deposited, causing nitriding of the Si and forming the high refractive index layer H (Si3N4 layer) of the anti-reflective section 10. At this time, the second sputtering source 120 is not operating. In addition, a noble gas may be introduced along with the O2 gas. Furthermore, when a noble gas (in this case, Ar gas) is introduced from the sputtering gas inlet 126 of the second sputtering source 120 and a DC voltage is applied to the sputtering cathode 122, the ITO on the surface of the second target T2 is deposited onto the surface of the substrate 2 by sputtering with Ar, forming the ITO layer 14 of the anti-reflective portion 10. At this time, the first sputtering source 110 and the radical source 130 are not operating. Note that a noble gas may also be introduced from the radical source 130. The film thickness of each layer of the anti-reflective coating 10 is controlled by the length of the sputtering time, provided that the power supplied to the sputter cathodes 112 and 122 is constant and the deposition rate, which is the physical film thickness deposited per unit time, is constant. Therefore, when a 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 deposition of each layer of the anti-reflective coating 10 is completed sequentially.

[0028] Once the formation of the anti-reflective portion 10 is complete, the drum 104 is stopped, and after appropriate cooling, the substrate 2 with the anti-reflective portion 10 attached is removed (step S6). Furthermore, one or more interlayer films may be applied between the anti-reflective portion 10 and the substrate 2 by the manufacturing apparatus 101 or another apparatus.

[0029] Subsequently, in order to form a surface layer 12 on the anti-reflective portion 10 of the substrate 2 with the anti-reflective portion 10, the substrate 2 with the anti-reflective portion 10 is placed in a known deposition apparatus or ion sputtering apparatus and treated by deposition or sputtering of a deposition material (organic material) for the surface layer 12 (step S7). In this way, a substrate 2 having a surface layer 12 and an anti-reflective layer 10, i.e., an optical product 1, is obtained. [Examples]

[0030] Next, Example 1 of the present invention and Comparative Examples 1 to 9, which do not belong to the present invention, will be described with reference to the drawings as appropriate. It should be noted that the present invention is not limited to the following examples. Furthermore, depending on how the present invention is interpreted, examples may become comparative examples, and comparative examples may become examples.

[0031] ≪Base material 2 etc.≫ In these examples and comparative examples, the substrate 2 is made of chemically strengthened glass and is a standard-sized disc for use as a lens filter. Substrate 2 is common to all examples and comparative examples, with a wall thickness of 2.00 mm and a refractive index of 1.52. Substrate 2 is not dyed or otherwise treated, and is colorless and transparent.

[0032] <<Example 1, Comparative Examples 1-9: Optical Multilayer Films, etc.>> Furthermore, in Example 1 and Comparative Examples 1-9, an optical multilayer film 4 was formed on the film-forming surface M on one side of the substrate 2. The optical multilayer films 4 of Example 1 and Comparative Examples 1-9 were formed as described in Tables 1-3. In Tables 1-3, "film thickness" refers to physical film thickness (nm). Furthermore, Comparative Example 0 was formed by omitting only the surface layer 12 from Example 1. Similarly, Comparative Examples 1' to 9' were formed by omitting only the surface layer 12 from Comparative Examples 1 to 9, respectively.

[0033] [Table 1] [Table 2] [Table 3]

[0034] In Example 1, the first layer of the optical multilayer film 4 is a Si3N4 layer, and the second layer is an ITO layer 14. Furthermore, the third layer is a Si3N4 layer, and from there to the 16th layer, it exhibits an alternating structure with SiO2 layers. The first to 16th layers of the optical multilayer film 4 in Example 1 constitute the anti-reflective portion 10. The anti-reflective portion 10 of Example 1 is formed by the manufacturing apparatus 101 in a state where cleaning (step S4) has been performed, and where DC is used in the first sputtering source 110, the second sputtering source 120, and the radical source 130. The 17th layer of the optical multilayer film 4 in Example 1 is the surface layer 12, which is an antifouling film. The antifouling film was formed in this case by depositing OF-SR manufactured by Canon Optron Inc. onto the anti-reflective section 10, resulting in a physical film thickness of 4.70 nm. The refractive index of this antifouling film at a wavelength of 500 nm was 1.350.

[0035] The layer structures of Comparative Examples 1 to 3 are identical to each other. This layer structure is similar to that of Example 1. More specifically, the ITO layer 14 of Example 1 is moved to the 14th layer, the first layer is made an SiO2 layer, and the second layer onwards is arranged in the same way as the first layer onwards of Example 1, excluding the ITO layer 14, to obtain this layer structure. The anti-reflective portion 10 of Comparative Example 1 is formed by the manufacturing apparatus 101 with the cleaning (step S4) omitted and with DC current used in the first sputtering source 110 and the second sputtering source 120. The anti-reflective portion 10 of Comparative Example 2 is formed by the manufacturing apparatus 101 with the cleaning (step S4) omitted and with RF used in the first sputtering source 110 and the second sputtering source 120. The anti-reflective portion 10 of Comparative Example 3 is formed by the manufacturing apparatus 101 after cleaning (step S4) has been performed, and with DC current being used in the first sputtering source 110 and the second sputtering source 120. Each surface layer 12 in Comparative Examples 1 to 3 is formed in the same manner as the surface layer 12 in Example 1.

[0036] The layer structure of Comparative Example 4 is obtained by moving the ITO layer 14 from the 14th layer to the 5th layer in the layer structures of Comparative Examples 1 to 3. The anti-reflective portion 10 of Comparative Example 4 is formed by the manufacturing apparatus 101 after cleaning (step S4) has been performed, and with DC current being used in the first sputtering source 110 and the second sputtering source 120. The surface layer 12 of Comparative Example 4 is formed in the same manner as the surface layer 12 of Example 1.

[0037] The layer structure of Comparative Example 5 is the same as that of Comparative Example 4, but with the fifth ITO layer 14 replaced by a ten-layer structure. This ten-layer structure extends from the fifth to the fourteenth layer of Comparative Example 5. In this ten-layer structure, the fifth, seventh, ninth, eleventh, and thirteenth layers of Comparative Example 5 are ITO layers 14 with a physical thickness of 1 nm. In addition, the sixth, eighth, tenth, twelfth, and fourteenth layers of Comparative Example 5 are Si3N4 layers with a physical thickness of 5 nm. The 15th layer and beyond of Comparative Example 5 are the same as the 6th layer and beyond of Comparative Example 4. The anti-reflective portion 10 of Comparative Example 5 is formed by the manufacturing apparatus 101 after cleaning (step S4) has been performed, and with DC current being used in the first sputtering source 110 and the second sputtering source 120. The surface layer 12 of Comparative Example 5 is formed in the same manner as the surface layer 12 of Example 1.

[0038] The layer structure of Comparative Example 6 is such that the 14th ITO layer 14 in the layer structures of Comparative Examples 1 to 3 is replaced with ITON, which is ITO treated with nitrogen radicals (plasma treatment). x Made by ITON x It is formed by replacing the layer and then moving it to the 15th layer (14th layer: Si3N4 layer with a physical film thickness of 58.59 nm). ITON x The layer is formed in the manufacturing apparatus 101 when nitrogen gas (N2 gas) is introduced into the radical gas inlet 134 of the radical source 130 during ITO sputtering, a high-frequency voltage is applied to the gun 136 to generate radical nitrogen, which is then irradiated onto the moving substrate 2 on which the ITO has been deposited. Here, x is determined by at least one of the voltage, frequency, and processing time of the radical source 130 (gun 136). Cleaning (step S4) is also performed at this stage. ITON in the anti-reflective section 10 of Comparative Example 6 x The layers other than the base layer are deposited by the manufacturing apparatus 101 after cleaning (step S4), and with DC current being used in the first sputtering source 110 and the second sputtering source 120. The surface layer 12 of Comparative Example 6 is formed in the same manner as the surface layer 12 of Example 1.

[0039] The layer structure of Comparative Example 7 is the 15th layer ITON in the layer structure of Comparative Example 6. x The layer is SiITON, which is ITO that has undergone Si sputtering and nitrogen radical treatment (plasma treatment). y The layer (physical film thickness 82.72 nm) is replaced, and the 16th SiO2 layer is omitted (16th layer: anti-fouling film). SITEN yThe layer is formed in the manufacturing apparatus 101 when sputtering of ITO by the second target T2 is performed simultaneously with sputtering of Si by the first target T1, and nitrogen gas (N2 gas) is introduced from the radical gas inlet 134 of the radical source 130, and a high-frequency voltage is applied to the gun 136 to generate radical nitrogen, which is then irradiated onto the moving substrate 2 on which Si and ITO have been deposited in a mixture. Here, y is determined by at least one of the voltage, frequency, and processing time of the radical source 130 (gun 136). Cleaning (step S4) is also performed at this stage. SiITON in the anti-reflective portion 10 of Comparative Example 7 y The layers other than the base layer are deposited by the manufacturing apparatus 101 after cleaning (step S4), and with DC current being used in the first sputtering source 110 and the second sputtering source 120. The surface layer 12 of Comparative Example 7 is formed in the same manner as the surface layer 12 of Example 1.

[0040] The layer structure of Comparative Example 8 is formed by moving the 14th ITO layer 14 in the layer structures of Comparative Examples 1 to 3 to the 1st layer. Layers 2 to 14 of Comparative Example 8 correspond in order to layers 1 to 13 of Comparative Examples 1 to 3. The anti-reflective layer 10 of Comparative Example 8 is formed by the manufacturing apparatus 101 after cleaning (step S4) has been performed, and with DC current being used in the first sputtering source 110 and the second sputtering source 120. The surface layer 12 of Comparative Example 8 is formed in the same manner as the surface layer 12 of Example 1.

[0041] The layer structure of Comparative Example 9 is obtained by changing the physical film thickness of the 15th Si3N4 layer in the layer structures of Comparative Examples 1 to 3 from 10 nm to 200 nm. The anti-reflective layer 10 of Comparative Example 9 is formed by the manufacturing apparatus 101 after cleaning (step S4) has been performed, and with DC current being used in the first sputtering source 110 and the second sputtering source 120. The surface layer 12 of Comparative Example 9 is formed in the same manner as the surface layer 12 of Example 1.

[0042] ≪Anti-reflective properties, scratch resistance, antistatic properties, etc. of Example 1 and Comparative Examples 1-9≫ The anti-reflective properties of Example 1 and Comparative Examples 1-9 are shown in Table 4.

[0043] [Table 4]

[0044] Regarding anti-reflective properties (light transmittance), the spectral reflectance distribution in the visible and adjacent regions was measured for Example 1. The results are shown in Figure 4. According to Figure 4, the reflectance is 0.5% or less across the entire visible spectrum, indicating that Example 1 exhibits excellent anti-reflective properties. Comparative Examples 1-9, 0, and 1'-9' are also designed to have an anti-reflective portion 10, and therefore basically have the same spectral reflectance distribution as Example 1. However, as shown in the "Absorption" column of Table 4, in Comparative Examples 1 and 6, unlike the others, absorption of more than 1% on average occurred for incident light in the visible range, and the light transmittance was inferior to the others (○) (△). In Comparative Example 1, the ITO layer 14 etc. was formed on the uncleaned substrate 2, and it is thought that absorption occurred mainly in the microscopically more disordered ITO layer 14. Also, in Comparative Example 6, mainly ITO x It is believed that absorption occurs in the layer. On the other hand, absorption also occurs in Comparative Examples 1' and 6', similar to Comparative Examples 1 and 6. Furthermore, regarding anti-reflective properties (light transmittance), preferably, the average of the double-sided reflectance in the wavelength range of 425 nm to 625 nm is 1% or less. Also, from the viewpoint of satisfying this standard with a design that is not excessively complex, it is preferable that the number of layers of the anti-reflective portion 10, including the ITO layer 14, be 17 or more.

[0045] Furthermore, the following scratch resistance tests were conducted for each product. Specifically, sandpaper (Scotch-Brite industrial pad #3000) attached to a reciprocating arm of the scratch testing machine was pressed against the optical multilayer film 4 with a load of 200g and moved back and forth 10 times (stroke of 20mm one way). The presence or absence of scratches was then confirmed by direct visual inspection. If one or more visible scratches were observed, it was evaluated as "×", and if no visible scratches were observed, it was evaluated as "○". First, comparative examples 0, 1' to 9', which lacked the surface layer 12 (anti-fouling film), all received an evaluation of "×" and exhibited poor scratch resistance. Next, as shown in the "Scratch Resistance" column of Table 4, Example 1 and Comparative Example 6 exhibited superior scratch resistance (○), unlike the others (×). The good scratch resistance was mainly due to the arrangement of the ITO layer 14 (second layer) in Example 1, or the ITON in Comparative Example 6. x This is thought to be due to the placement of layers.

[0046] Furthermore, the resistance values ​​were measured for each material to assess its antistatic properties. Specifically, the surface resistance value (ohms per square meter; Ω / □) per unit area (here, 1 square centimeter) was measured using a surface resistance measuring instrument. The lower the resistance value, the easier it is to dissipate static electricity and the less likely it is to accumulate static charge, resulting in superior antistatic properties. Also, the resistance value is 1 × 10⁻⁶. 10 If the resistance is less than or equal to Ω / □, charged polystyrene powder will not adhere to an optical product having that resistance when brought into contact with it, and the resistance will be 1 × 10⁻⁶. 11 If the resistance is less than Ω / □, the charged polystyrene powder will almost adhere to the optical product at the moment of contact, but will immediately fall off. Therefore, in this case, the resistance value is 1 × 10 11 A value of Ω / □ or less is considered to have good antistatic properties. Therefore, Example 1 and Comparative Examples 1-4, 6, and 8-9 exhibit good antistatic performance. The inferior antistatic performance of Comparative Example 5 is thought to be due to the physical film thickness of each ITO layer 14 being too thin at 1 nm, preventing sufficient conductivity from being obtained in each ITO layer 14. Furthermore, the inferior antistatic performance of Comparative Example 7 is due to the use of SiITON compared to ITO. yThis is thought to be due to its low conductivity.

[0047] Furthermore, in Example 1, good results were obtained in all aspects: anti-reflective properties, scratch resistance, and antistatic properties.

[0048] Summary etc. Example 1 is an optical product 1 in which an optical multilayer film 4 is directly formed on one side of a substrate 2. The optical multilayer film 4 comprises an anti-reflective portion 10 and a surface layer 12 located on the air side. The surface layer 12 includes an anti-fouling film. The anti-reflective portion 10 has a plurality of low refractive index layers L made of a low refractive index material, a plurality of high refractive index layers H made of a high refractive index material, and an ITO layer 14 made of ITO. The high refractive index material is Si3N4. The first layer of the anti-reflective portion 10, counting from the substrate 2 side, is a high refractive index layer H. The second layer of the anti-reflective portion 10, counting from the substrate 2 side, is an ITO layer 14. Therefore, an optical product 1 is provided in which antistatic performance, scratch resistance, and anti-reflective performance coexist at a higher level.

[0049] Furthermore, the low refractive index material in Example 1 is SiO2. Therefore, a low refractive index material of sufficient quality can be obtained at a lower cost. Furthermore, in Example 1, the average double-sided reflectance in the wavelength range of 425 nm to 625 nm is 1% or less. Therefore, the anti-reflective performance is more sufficient.

[0050] In addition, in Example 1, the odd-numbered layers from the third layer onward of the anti-reflective portion 10 are high-refractive-index layers H, and the even-numbered layers from the fourth layer onward of the anti-reflective portion 10 are low-refractive-index layers L. Therefore, an anti-reflective portion 10 with reflection suppression function can be more easily obtained by an alternating layer of high-refractive-index layers H and low-refractive-index layers L. Furthermore, the number of layers in the anti-reflective section 10 is 16, including the ITO layer 14. Therefore, a sufficient reflection suppression function can be obtained in the anti-reflective section 10, which includes the high refractive index layer H made of Si3N4. Furthermore, the surface layer 12 is made of an organosilicon compound. Therefore, a sufficiently smooth antifouling film that contributes to improved scratch resistance can be obtained more easily. Furthermore, at least one of the high refractive index layer, the low refractive index layer, and the ITO layer 14 is formed by sputtering. Therefore, at least one of the high refractive index layer, the low refractive index layer, and the ITO layer 14 is obtained that further contributes to improving at least one of the antistatic performance, scratch resistance, and anti-reflective performance.

Claims

1. An optical product having an optical multilayer film formed directly or via an interlayer on at least one side of a substrate, The optical multilayer film comprises an anti-reflective portion and a surface layer located closest to the air. The aforementioned surface layer includes an anti-fouling film. The anti-reflective portion comprises a plurality of low refractive index layers made of a low refractive index material, a plurality of high refractive index layers made of a high refractive index material, and an ITO layer made of ITO. The aforementioned high refractive index material is Si ３ N ４ And, The first layer from the substrate side of the anti-reflective portion is the high refractive index layer. The second layer from the substrate side of the anti-reflective portion is the ITO layer. The odd-numbered layers from the third layer onwards, counting from the substrate side of the anti-reflective portion, are the high refractive index layers. The even-numbered layers from the fourth layer onwards, counting from the substrate side of the anti-reflective portion, are the low refractive index layers. The number of layers in the anti-reflective section, including the ITO layer, is 16. Optical products characterized by the following features.

2. The low refractive index material is SiO ２ That is The optical product according to feature 1.

3. The average bilateral reflectance in the wavelength range of 425 nm to 625 nm is 1% or less. The optical product according to claim 1 or 2.

4. The aforementioned surface layer is made of an organosilicon compound. The optical product according to any one of claims 1 to 3.

5. The anti-reflective portion is formed by forming at least one of the high refractive index layer, the low refractive index layer, and the ITO layer in the optical product according to any one of claims 1 to 4 on one side of the substrate, either directly or via an interlayer, by sputtering. Subsequently, the surface layer is formed A method for manufacturing optical products characterized by the following:

Images