Glass film with near-infrared shielding film, near-infrared shielding film laminate, method for producing glass film with near-infrared shielding film, and method for producing near-infrared shielding film laminate

Abstract

The present invention addresses the problem of providing: a method for efficiently producing a composite tungsten oxide film (an electrically insulating heat-ray-shielding film); and a glass film with a near-infrared-ray-shielding film obtained by the method. [Solution] A glass film (101A, 102A) with a near-infrared shielding film, characterized by comprising a glass film (101, 102) having a thickness of 200 [mu] m or less, and a near-infrared shielding film (103, 104) formed on one surface of the glass film and comprising a composite tungsten oxide having a hexagonal crystal structure represented by general formula MxWyOz, the maximum value of transmittance of the near-infrared shielding film in a visible light region having a wavelength of 380-780 nm is 5% or more, and the reflectivity of the near-infrared shielding film at a wavelength of 1400 nm is 30% or more. In addition, a near-infrared shielding film laminate (100A) obtained by bonding the near-infrared shielding film-equipped glass film to a sheet glass (100) or the like can be used in windows of automobiles or buildings requiring heat ray shielding properties and radio wave transmission properties.

Description

Technical Field

[0001] This invention relates to a glass film with a near-infrared shielding film that transmits light in the visible wavelength region and reflects and shields light in the near-infrared region, a near-infrared shielding film laminate, a method for manufacturing a glass film with a near-infrared shielding film, and a method for manufacturing a near-infrared shielding film laminate. Background Technology

[0002] Window components, such as those made of plate glass, are used in automobile windows, building windows, etc., and include a film that allows visible light to pass through while shielding near-infrared rays, which are heat rays. These window components have a near-infrared shielding film formed by dispersing infrared-absorbing material particles, such as cesium tungsten bronze, in a resin that is transparent to visible light on the surface of a transparent substrate such as plate glass. Patent Document 1 discloses an infrared-absorbing material particle dispersion in which composite tungsten oxide particles are dispersed in a medium such as resin.

[0003] However, since the near-infrared shielding film disclosed in Patent Document 1 is formed by coating a dispersion of infrared absorbing material particles, a highly sophisticated coating technique is required to ensure control of film thickness, uniformity of film thickness over a large area, and flatness.

[0004] Therefore, there are technologies that utilize sputtering or other methods to deposit near-infrared shielding materials onto glass plates to form near-infrared shielding films instead of coating methods. Patent Document 2 discloses an infrared reflective film formed by stacking multiple metal layers using different metals formed by sputtering with a dielectric layer.

[0005] However, when metal is sputtered into a film, the film exhibits conductivity, which, if used in window materials, blocks radio waves between the outside and inside. Wireless, FM radio waves operate in the Very High Frequency (VHF) band (30MHz-0.3GHz). Mobile phones and mobile communication use radio waves operate in the Ultra High Frequency (UHF) band (0.3GHz-3GHz). Particularly useful communication radio waves operate in the 0.9GHz-2.2GHz range, while those used for wireless local area networks (WLANs) operate in the 2.45GHz and 5.2GHz bands. In high-speed data communication and satellite communication, technologies for the shorter wavelength Ultra High Frequency (SHF) band (3GHz-30GHz) have been developed. Radio waves in these bands are preferably transmissive. However, infrared reflective films (thermal reflective films) using thin metal films reflect GHz and MHz band radio waves used for these signal transmissions, therefore countermeasures such as incorporating cuts in a portion of the film are necessary.

[0006] The reflectivity of radio waves in the MHz and GHz bands is closely related to the surface resistivity of the film. Generally, the higher the surface resistivity, the better the radio wave transmittance. If the surface resistivity is 10... 5 If the surface resistivity is above Ω / □, it will produce considerable transmittance in the VHF and UHF bands. 6 With a surface resistivity of Ω / □ or higher, approximately the same electromagnetic wave transmittance as float glass can be obtained across the entire VHF, UHF, and SHF frequency bands (Non-Patent Document 1). Therefore, to ensure electromagnetic signal transmittance, a surface resistivity of at least 10 Ω / □ is required. 5 Ω / □ or higher, preferably 10 6 High resistance of Ω / □ or higher (Non-Patent Document 1).

[0007] Patent Document 3, similar to Patent Document 2, discloses a composite tungsten oxide film (electrically insulating hot wire shielding film), wherein the composite tungsten oxide film is formed by sputtering, and the sheet resistance is 10. 5 The absorption rate is above Ω / □, and the absorption rate at a wavelength of 1400nm is above 35%. With the popularization of electric vehicles, the function of shielding the hot wire to reduce the air conditioning load and increase the driving range is essential. At the same time, with the increasing comfort and autonomous driving in automobiles, it is also required that the windows of automobiles have the transmittance of various sensor signals. Therefore, the composite tungsten oxide film (electrically insulating hot wire shielding film) disclosed in Patent Document 3 has attracted attention.

[0008] Here, when it is desired to use composite tungsten oxide materials such as cesium tungsten bronze as a target and obtain an electrically insulating and transparent thermally shielded film by sputtering, it is necessary to heat the substrate used as the film-forming body to above 300°C during sputtering, or to anneal it at a temperature above 300°C after sputtering to crystallize the sputtered film (composite tungsten oxide film). Therefore, a plate glass capable of withstanding the heat during sputtering or annealing is used as the substrate used as the film-forming body.

[0009] However, when using plate glass as the substrate, it is difficult to make the plate glass into a roller shape and continuously transport it by roller-to-roll. Therefore, there is a problem that the composite tungsten oxide film (electrically insulating heat-shielding film) cannot be manufactured efficiently.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: WO2005 / 037932.

[0013] Patent Document 2: Japanese Patent Application Publication No. 2006-117482.

[0014] Patent document 3: Japanese Patent No. 6540859.

[0015] Non-patent literature

[0016] Non-patent literature 1: Hiroshi Itō, Keisuke Tanaka, Yuji Yamamoto, Yasuo Hashimoto, Hiroshi Kurihara, “Improvement of TV wave reflection characteristics of high performance hot-wire reflective glass”, Television Society Technical Report, Vol. 15, pp. 15-21 (1991). Summary of the Invention

[0017] The problem that the invention aims to solve

[0018] The present invention was made in view of the problem that provides a method for efficiently manufacturing a composite tungsten oxide film (an electrically insulating hot wire shielding film) and a glass film with a near-infrared shielding film obtained by the manufacturing method.

[0019] More specifically, a method for manufacturing a glass film with a near-infrared shielding film is provided, wherein a glass film is used instead of a plate glass as the substrate, and a composite tungsten oxide film (an electrically insulating hot wire shielding film) is formed by heating or non-heating using a method such as sputtering, and then annealed after the glass film is continuously conveyed by a roller-to-roll method. Furthermore, a glass film with a near-infrared shielding film obtained by this manufacturing method is provided, and a near-infrared shielding film laminate formed by bonding the glass film with the near-infrared shielding film to a transparent substrate such as a plate glass or a polycarbonate plate is provided, as well as a method for manufacturing the same.

[0020] Methods for solving problems

[0021] That is, the first invention of the present invention is a glass film with a near-infrared shielding film, characterized in that it is a glass film with a near-infrared shielding film composed of a glass film with a thickness of less than 200 μm and a near-infrared shielding film, wherein the near-infrared shielding film is formed on at least one side of the glass film, and the near-infrared shielding film is composed of a composite tungsten oxide, wherein the composite tungsten oxide is represented by the general formula MxWyOz and has a hexagonal crystal structure, where M is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, and Ti, W is tungsten, O is oxygen, and 0.2≤x / y≤0.5, 2.5≤z / y≤3.0. The aforementioned near-infrared shielding film has a maximum transmittance of 5% or more in the visible light region with wavelengths above 380nm and below 780nm, and the aforementioned near-infrared shielding film has a reflectance of 30% or more under a wavelength of 1400nm.

[0022] Furthermore, the second invention is characterized in that, in the glass film with a near-infrared shielding film described in the first invention, the thickness of the near-infrared shielding film is 10 nm or more and 500 nm or less.

[0023] The third invention is characterized in that, in the glass film with a near-infrared shielding film described in the first or second invention, the surface resistivity of the near-infrared shielding film is 10. 5 Ω / □ and above.

[0024] The fourth invention is characterized in that, in the glass film with a near-infrared shielding film described in the first invention, a bonding layer is formed on the surface of the near-infrared shielding film.

[0025] The fifth invention is characterized in that, in the glass film with a near-infrared shielding film described in the fourth invention, the bonding layer is composed of an oxide selected from SiO2, Al2O3, ZrO2, TiO2, and HfO2.

[0026] Then, the sixth invention of the present invention is characterized in that the near-infrared shielding film laminate is composed of a transparent substrate that transmits visible light and a glass film with a near-infrared shielding film as described in the first or fourth invention, which is laminated on the transparent substrate.

[0027] The seventh invention is characterized in that, in the near-infrared shielding film laminate described in the sixth invention, the transparent substrate is composed of an inorganic material selected from glass and transparent ceramic, or an organic material selected from resin film and resin plate.

[0028] Furthermore, the eighth invention is characterized in that, in the method for manufacturing the glass film with a near-infrared shielding film described in the first invention, it comprises: The glass film unwinding process is used to unwind glass films with a thickness of less than 200μm that are wound on the unwinding roller. The film-forming process involves simultaneously conveying a glass film unwound from an unwinding roller via a roller-to-roll method, and simultaneously forming a composite tungsten oxide film, represented by the general formula MxWyOz, onto at least one surface of the glass film using a film-forming mechanism. M is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, and Ti; W is tungsten; O is oxygen; and 0.2 ≤ x / y ≤ 0.5, 2.5 ≤ z / y ≤ 3.0. The heat treatment process involves heat-treating the glass film containing composite tungsten oxide at a temperature below its strain point to form a near-infrared shielding film composed of composite tungsten oxide with a hexagonal crystal structure.

[0029] The ninth invention is characterized in that, in the method for manufacturing a glass film with a near-infrared shielding film described in the eighth invention, in the above-mentioned heat treatment process, a plurality of heat treatment mechanisms are used to sequentially heat treat the glass film with a composite tungsten oxide film, and the initial heat treatment mechanism is composed of an infrared heater that emits infrared rays with a wavelength of 1500 nm or more.

[0030] The tenth invention is characterized in that, in the method for manufacturing a glass film with a near-infrared shielding film described in the ninth invention, the aforementioned initial heat treatment mechanism is composed of a carbon heater or a SiC heater.

[0031] Furthermore, the eleventh invention is characterized in that the manufacturing method of the near-infrared shielding film laminate described in the sixth invention includes a hot pressing step, in which a glass film with a near-infrared shielding film described in the first or fourth invention is hot-pressed with a transparent substrate made of organic material described in the seventh invention.

[0032] The twelfth invention is characterized in that the method for manufacturing the near-infrared shielding film laminate described in the sixth invention includes: a surface activation step, which activates the surface of at least one of the glass film with near-infrared shielding film described in the first or fourth invention and the transparent substrate made of inorganic material described in the seventh invention; and a bonding step, which bonds the glass film with near-infrared shielding film to the transparent substrate via the activated surface.

[0033] The effects of the invention

[0034] According to the glass film with near-infrared shielding film and its manufacturing method of the present invention, since the substrate on which the near-infrared shielding film composed of a composite tungsten oxide with a hexagonal crystal structure is formed is applied, the glass film has a thickness of 200 μm or less. Therefore, the glass film is made into a roller shape and can be continuously conveyed by roller-to-roll method. Therefore, it has the effect of efficiently manufacturing a composite tungsten oxide film that functions as a heat shielding film. Attached Figure Description

[0035] Figure 1 This is an explanatory diagram of the structure of a conventional near-infrared shielding film laminate in which a plate glass 10 is used as a substrate and near-infrared shielding films 11 and 12 are formed on its two sides.

[0036] Figure 2This diagram illustrates the structure of the glass films 101A and 102A with near-infrared shielding films 103 and 104 formed on one side of the glass films 101 and 102 used as substrates, the transparent substrate 100, and the near-infrared shielding film laminate 100A of this embodiment, in which glass films 101A and 102A with near-infrared shielding films 103 and 104 are bonded to both sides of the transparent substrate 100.

[0037] Figure 3 This diagram illustrates the structure of the glass films 201A and 202A with near-infrared shielding films of this embodiment, which use glass films 201 and 202 as substrates and have near-infrared shielding films 203 and 204 and bonding layers 205 and 206 formed on one side thereon; the transparent substrate 200 with bonding layers 207 and 208 formed on both sides thereon; and the near-infrared shielding film laminate 200A of this embodiment, in which each glass film 201A and 202A with near-infrared shielding films is bonded to both sides of the transparent substrate 200 via the bonding layers 205, 206, 207, and 208.

[0038] Figure 4 This is an illustration of the structure of a roll-to-roll sputtering apparatus that continuously feeds glass film in a roll-to-roll manner to manufacture glass film with near-infrared shielding film and then winds the manufactured glass film with near-infrared shielding film into a roll shape.

[0039] Figure 5 This is an illustration of the structure of a roller-to-roll sputtering apparatus that continuously feeds glass film in a roller-to-roll manner to manufacture glass film with near-infrared shielding film and cuts (slits) the manufactured glass film with near-infrared shielding film into sheets.

[0040] Figure 6 This is a process illustration of manufacturing the near-infrared shielding film laminate 515 of this embodiment by continuously bonding long strips of glass films 501 and 502 with near-infrared shielding films to two sides of a transparent substrate 500.

[0041] Figure 7 This diagram illustrates the process of manufacturing the near-infrared shielding film laminate 606 of this embodiment by bonding the cut (slit) glass films 601 and 602 with near-infrared shielding films to the two sides of the transparent substrate 600. Detailed Implementation

[0042] The embodiments of the present invention will be described in detail below.

[0043] 1. Glass film with near-infrared shielding film

[0044] The glass film with a near-infrared shielding film of the present invention is characterized in that it is a glass film with a near-infrared shielding film composed of a glass film with a thickness of less than 200 μm and a near-infrared shielding film, wherein the near-infrared shielding film is formed on at least one side of the glass film, and the near-infrared shielding film is composed of a composite tungsten oxide, wherein the composite tungsten oxide is represented by the general formula MxWyOz (where M is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, Ti, W is tungsten, O is oxygen, 0.2≤x / y≤0.5, 2.5≤z / y≤3.0) and has a hexagonal crystal structure, wherein the near-infrared shielding film has a maximum transmittance of 5% or more in the visible light region with a wavelength of 380 nm or more and 780 nm or less, and the near-infrared shielding film has a reflectance of 30% or more under a wavelength of 1400 nm.

[0045] Hereinafter, the “(1) near-infrared shielding film”, “(2) glass film” and “(3) bonding layer” constituting the glass film with near-infrared shielding film of the present invention will be specifically described.

[0046] (1) Near-infrared shielding film

[0047] The aforementioned near-infrared shielding film is composed of composite tungsten oxide, which is necessary for forming a film with high transparency in the visible wavelength region and reflectivity in the near-infrared wavelength region.

[0048] The basic optical properties of the near-infrared shielding film composed of a composite tungsten oxide film represented by the general formula MxWyOz (where M is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, Ti, W is tungsten, O is oxygen, 0.2≤x / y≤0.5, 2.5≤z / y≤3.0) originate from the atomic configuration of tungsten (W) and oxygen (O).

[0049] Specifically, when the composite tungsten oxide constituting the near-infrared shielding film has a hexagonal crystal structure, the transmittance of the near-infrared shielding film in the visible light region is improved, and the shielding performance in the near-infrared region with wavelengths greater than 780 nm (according to the "Infrared Heating Terminology" compiled by the Japan Electrothermal Association, wavelengths 780 nm to 2000 nm, refer to JIS Z 8117 2002) is improved. Furthermore, when the composite tungsten oxide has a uniform hexagonal crystal structure, the amount of element M added relative to tungsten 1 is preferably 0.2 or more and 0.5 or less, more preferably 0.33. It can be considered that by using composite tungsten oxide as M... 0.33 In WO3, element M is disposed in all the interstices of the hexagon. From the viewpoint of obtaining a hexagonal crystal structure, element M of the composite tungsten oxide is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, and Ti, preferably selected from Rb and Cs, and further preferably selected from Cs.

[0050] Furthermore, the aforementioned near-infrared shielding film has a maximum transmittance of 5% or more in the visible light region with wavelengths of 380 nm or higher and 780 nm or lower, and a reflectance of 30% or more at a wavelength of 1400 nm. The near-infrared shielding film made of the composite tungsten oxide of this embodiment has a reflectance peak in the wavelength range of 1400 nm to 2700 nm. If the reflectance at a wavelength of 1400 nm is 30% or more, the incidence of near-infrared rays from sunlight entering through the window that contribute to rising room temperature can be reduced. Additionally, the near-infrared shielding film made of the composite tungsten oxide of this embodiment has a transmittance peak in the visible light region with wavelengths of 400 nm to 700 nm. If a glass film with a near-infrared shielding film having a maximum transmittance of 5% or more in the visible light region is used for windows, even if it is difficult to observe the interior from the outside, the outside can be visually identified from the inside.

[0051] Here, in order for the near-infrared shielding film composed of composite tungsten oxide to exhibit the aforementioned optical properties (i.e., a maximum transmittance of 5% or more in the visible light region with wavelengths above 380 nm and below 780 nm, and a reflectance of 30% or more at a wavelength of 1400 nm), the crystallinity of the composite tungsten oxide is important. To achieve crystallinity in the composite tungsten oxide, it is necessary to form the film at a temperature of 400°C or higher, or to heat-treat (anneal) a non-heat-treated film formed at a temperature below 400°C at a temperature of 400°C or higher. Alternatively, film formation at a temperature of 400°C or higher and heat treatment at a temperature of 400°C or higher can be combined.

[0052] Furthermore, in this invention, reflection (a reflectivity of 30% or more at a wavelength of 1400 nm) is utilized in the near-infrared shielding film. When light in the visible light region is transmitted while light in the near-infrared region is blocked, the near-infrared shielding film absorbs or reflects the near-infrared light, thereby blocking it. Here, if near-infrared light is absorbed, the absorbed light is converted into heat, heating the near-infrared shielding film and the glass film used as the substrate, causing thermal expansion of the glass film with the near-infrared shielding film. In the near-infrared shielding film laminate described later, when the coefficients of thermal expansion of the glass film with the near-infrared shielding film and the laminated transparent substrate that transmits visible light are not similar, the glass film with the near-infrared shielding film, which expands due to near-infrared absorption, may break. On the other hand, if the near-infrared shielding film reflects near-infrared light, the glass film with the near-infrared shielding film is heated less by near-infrared light, resulting in less thermal expansion and preventing breakage due to near-infrared irradiation.

[0053] Furthermore, the surface resistivity of the near-infrared shielding film in this embodiment is preferably 10 Ω·cm.5 Ω / □ or higher, more preferably 10 6 Ω / □ or higher. Furthermore, the thickness of the near-infrared shielding film is preferably 10 nm or more and 500 nm or less, more preferably 10 nm or more and 300 nm or less.

[0054] It should be noted that when forming the near-infrared shielding film laminate described later, if a resin film is used as a transparent substrate that transmits visible light, the thickness of the near-infrared shielding film can also be set to 10 nm or more and 250 nm or less. By thinning the thickness of the near-infrared shielding film, the crystallinity of the near-infrared shielding film can be improved, thereby further enhancing the reflectivity in the near-infrared region.

[0055] (2) Glass film

[0056] The glass film used in the glass film with near-infrared shielding film of the present invention preferably has a thickness of 10 μm or more and 200 μm or less, more preferably 10 μm or more and 100 μm or less. When the thickness of the glass film is less than 10 μm, processing becomes difficult, and if the thickness is greater than 200 μm, difficulties may arise in winding and other aspects.

[0057] There are no particular limitations on the materials used for the aforementioned glass film. For example, silicate glass, silica glass, borosilicate glass, soda-lime glass, aluminosilicate glass, chemically strengthened glass, alkali-free glass, etc., can be used.

[0058] In the manufacturing method of the glass film with near-infrared shielding film of the present invention, as described later, a heat treatment process is performed after the film-forming process of the composite tungsten oxide. Considering the deformation of the glass film, the heat treatment temperature in the heat treatment process is preferably set below the strain point. The strain point of the glass film is preferably 550°C or higher. In order to achieve a higher processing temperature in the heat treatment process, the glass film with the composite tungsten oxide film can be made of the aforementioned silicate glass, silica glass, borosilicate glass, soda-lime glass, aluminosilicate glass, chemically strengthened glass, or alkali-free glass.

[0059] Furthermore, glass films can be formed using conventional methods such as floating, rolling, slit-pull, overflow-pull, and re-pull. Among these, the overflow-pull method is preferred. Glass films formed by the overflow-pull method can be formed within a thickness range of 10 μm or more and 200 μm or less, maintaining surface smoothness.

[0060] Furthermore, when a plate glass is used as the transparent substrate of the near-infrared shielding film laminate described later, the difference in thermal expansion coefficients between the glass film and the plate glass must be within 10% of the smaller of their thermal expansion coefficients. In the near-infrared shielding film laminate, when the difference in thermal expansion coefficients between the glass film and the aforementioned plate glass is greater than 10%, the glass film sometimes breaks. The near-infrared shielding film of the present invention is characterized by a reflectivity of 30% or more at a wavelength of 1400 nm, thus shielding near-infrared rays through reflection. As a result, even when irradiated with near-infrared rays, the expansion of the glass film is minimal. On the other hand, when shielding near-infrared rays through absorption, even if the difference in thermal expansion coefficients between the glass film and the plate glass is controlled to within 5%, the glass film may still break.

[0061] (3) Bonding layer

[0062] A bonding layer can be provided on the surface of the near-infrared shielding film of the glass film with near-infrared shielding film of the present invention. When a near-infrared shielding film laminate is formed by stacking the glass film with near-infrared shielding film and a transparent substrate that transmits visible light, the bonding layer is disposed between the near-infrared shielding film and the transparent substrate to bond the two together. If the surface of the bonding layer is cleaned with an ion beam or the like and then pressed at room temperature, the glass film with near-infrared shielding film and the transparent substrate that transmits visible light can be bonded together.

[0063] The preferred bonding layer is composed of oxides selected from SiO2, Al2O3, TiO2, ZrO2, and HfO2. The surface of the bonding layer composed of these oxides is cleaned and activated by ion beam, plasma irradiation, atmospheric pressure plasma irradiation, and corona discharge, thereby enabling room temperature bonding.

[0064] Furthermore, the thickness of the bonding layer is preferably 1 nm or more and 10 nm or less, more preferably 3 nm or more and 10 nm or less. When the thickness of the bonding layer is less than 1 nm, the bonding effect cannot be expected. On the other hand, when the thickness of the bonding layer is greater than 10 nm, it may sometimes affect the heat treatment of the composite tungsten oxide and hinder the crystallization of the composite tungsten oxide.

[0065] The bonding layer can be formed by sputtering. Sputtering targets using metals or metal oxides as raw materials for forming the bonding layer can be used. To form an Al₂O₃ film, a metal Al target or an Al₂O₃ target of a metal oxide can be used; to form a TiO₂ film, a metal Ti target or a TiO₂ target of a metal oxide can be used; to form a ZrO₂ film, a metal Zr target or a ZrO₂ target of a metal oxide can be used; and to form an HfO₂ film, a metal Hf target or an HfO₂ target of a metal oxide can be used. Even with metal targets, insulating metal oxides can be obtained through reactive sputtering with introduced oxygen.

[0066] 2. Manufacturing method of glass film with near-infrared shielding film

[0067] (1) Film forming process

[0068] The near-infrared shielding film of the present invention utilizes the reflection of near-infrared rays (with a reflectivity of more than 30% under the condition of wavelength 1400nm) to shield near-infrared rays.

[0069] To obtain a near-infrared shielding film composed of composite tungsten oxide that reflects near-infrared radiation, it is preferable to deposit the film on a glass film as a substrate using magnetron sputtering, ion beam sputtering, pulsed laser deposition, or electron beam evaporation. In these film-forming methods, the composite tungsten oxide is formed as a continuous film.

[0070] In addition, if possible, heating the film to a temperature above 400°C during film formation can also help improve the crystallinity of the composite tungsten oxide.

[0071] (1-1) Film formation method using sputtering

[0072] There are no particular limitations on the target used when forming a composite tungsten oxide film (which is an untreated film if it cannot be crystallized by heat treatment). For example, a cesium composite tungsten oxide sintered target can be used.

[0073] For the composition of the target used in forming the composite tungsten oxide (unheat-treated film), for example, the molar ratio of cesium (Cs) to tungsten (W), i.e., Cs / W, is preferably 0.2 or more and 0.7 or less. This is because the composition of the target used in film formation is reflected in the molar ratio of cesium (Cs) to tungsten (W) contained in the formed film, i.e., Cs / W.

[0074] It should be noted that the crystal structure of the target does not directly affect the crystal structure of the film, therefore there are no particular limitations. Furthermore, the relative density of the target is preferably 70% or higher, and the resistivity is preferably 1 Ω. Less than cm.

[0075] There are no particular limitations on the manufacturing method of the target; for example, it can be manufactured by hot-pressing sintering cesium composite tungsten oxide powder in a vacuum or inactive environment. This is because the sintered body manufactured in this way has the strength to withstand the machining and brazing temperatures during target manufacturing, and has the conductivity to be DC sputtered.

[0076] The sputtering method described above can be used to form composite tungsten oxide (untreated film). When using sputtering as a film formation method, DC sputtering with a DC voltage or pulsed voltage applied to the target is preferred. This is because it offers high film formation speed and excellent productivity.

[0077] When forming a composite tungsten oxide (unheat-treated film) film, there are no particular limitations on the sputtering gas; for example, argon or a mixture of argon and oxygen can be used.

[0078] Whether to use argon or a mixed gas in the film-forming process can be selected based on the conditions of the next step, the "heat treatment process".

[0079] When a mixed gas is used as the sputtering gas in the film-forming process, the oxygen concentration is not particularly limited. When the oxygen concentration in the mixed gas is high, the film-forming speed decreases and the productivity decreases. Therefore, it is preferable that the oxygen concentration in the mixed gas is less than 20 vol%, and more preferably 5 vol% or more and 10 vol% or less.

[0080] When argon is used as the sputtering gas in the film formation process, it is preferable that the argon purity is 99 vol% or higher and the oxygen concentration is less than 1 vol.

[0081] Furthermore, as a specific condition for the film-forming process, the ultimate vacuum degree before target pre-sputtering and introduction of reactive gas is preferably less than 1×10⁻⁶. -4 Pa, more preferably less than 1×10 -5 Pa.

[0082] (1-2) Film formation methods using pulsed laser deposition

[0083] Pulsed Laser Deposition (PLD) involves irradiating a target material placed inside a vacuum chamber with a laser from outside. This process ablates (strips away) atoms or molecules from the target, forming a thin film on a substrate opposite the target. PLD is effective for target materials with high laser absorption.

[0084] Furthermore, pulsed laser deposition can also utilize sheet-like targets with a diameter of approximately 20 mm. Therefore, pulsed laser deposition can be appropriately applied.

[0085] Furthermore, pulsed laser deposition does not require plasma gases such as argon for sputtering. Moreover, since the target composition can be transferred to the substrate, films containing the target composition can be easily formed.

[0086] In pulsed laser deposition, the target does not require cooling because the duty cycle of the laser irradiating the target is small. Therefore, the backplate found on targets used in sputtering is not required.

[0087] Oxygen, nitrogen, carbon, etc. contained in the target are sometimes discharged during film formation, and can also be adjusted by introducing reactive gases into the film formation process.

[0088] Furthermore, as a specific condition for the film-forming process, the ultimate vacuum degree before introducing the reactive gas is preferably less than 1 × 10⁻⁶. -4 Pa, more preferably less than 1×10 -5 Pa.

[0089] (1-3) Film formation methods using electron beam evaporation

[0090] Electron beam evaporation is a method that uses 1×10 -2 A vapor deposition method in which an electron beam is irradiated onto a target to be vaporized under reduced pressure conditions below Pa, causing the target to heat and evaporate, thus forming a film on a substrate. The same target as that used in sputtering can be used.

[0091] (2) Heat treatment process

[0092] For composite tungsten oxide (untreated film) formed on the surface of a glass film by sputtering or other film-forming methods, heat treatment is performed to form a hexagonal crystalline structure. The heat treatment is carried out according to the gas environment selected during sputtering or other film-forming methods to ensure that the oxygen concentration of the near-infrared shielding film composed of composite tungsten oxide after heat treatment is within an appropriate range. The heat treatment environment is selected based on the gas used during sputtering or other film-forming methods.

[0093] When sputtering is used as the film formation method, if a mixture of argon and oxygen is used for film formation, the heat treatment of the composite tungsten oxide (untreated film) in the heat treatment process is carried out in an inactive or reducing environment at a temperature of 400°C to 900°C, preferably 400°C to 700°C, and more preferably 400°C to 650°C. Nitrogen, argon, a mixture of hydrogen and nitrogen, or a mixture of hydrogen and argon can be used as the inactive or reducing environment. When film formation is carried out in an oxygen-containing environment, if the heat treatment process is carried out in an oxidizing environment such as air or oxygen, excessive oxidation of the film occurs, oxygen vacancies decrease, the crystal structure changes, and the thermal shielding performance sometimes decreases. When the heat treatment temperature is below 400°C, the composite tungsten oxide (untreated film) is amorphous and does not crystallize, or even if it crystallizes, the hexagonal diffraction peaks in X-ray diffraction are extremely weak, resulting in low thermal shielding performance. Furthermore, the hexagonal crystal structure maintains its structure even at high temperatures above 900℃ in inactive or reducing environments. However, if the heat treatment temperature exceeds 1000℃, the reaction between the composite tungsten oxide (untreated film) and the glass film leads to film deterioration or peeling, resulting in film disappearance. Considering these factors, it is necessary to appropriately adjust the heat treatment conditions to achieve a reflectivity of over 30% at a wavelength of 1400nm.

[0094] Furthermore, the heat treatment temperature needs to take into account the strain point and glass transition temperature of the glass film, especially when heat treatment is performed at higher temperatures than the glass transition temperature, which can sometimes cause deformation of the glass film. Here, "strain point" refers to the viscosity of the heated glass at approximately 10... 13 dPa The viscosity of s is determined by the temperature at which the "strain point" is lower than the glass transition temperature. Therefore, it is preferable to perform heat treatment at a temperature below the "strain point".

[0095] 3. Near-infrared shielding film laminate

[0096] The near-infrared shielding film laminate of the present invention is composed of a transparent substrate that transmits visible light and a glass film with the aforementioned near-infrared shielding film laminated on the transparent substrate.

[0097] (1) Previous near-infrared shielding film laminate

[0098] As a substrate, the glass plate 10 is used to form near-infrared shielding films 11 and 12 composed of composite tungsten oxide on both sides of the glass plate 10 by film formation methods such as sputtering, which enables the manufacture of... Figure 1 The near-infrared shielding film laminate shown is an example. However, when plate glass 10 is used as a substrate, as described above, it is difficult to form the plate glass 10 into a roll shape and continuously convey it by roller-to-roll, thus hindering efficient manufacturing. Figure 1The near-infrared shielding film laminate shown.

[0099] In addition, near-infrared shielding films made of composite tungsten oxides require heat treatment of the composite tungsten oxides (untreated films) at temperatures above 400°C to crystallize them. Therefore, resin films cannot be used as substrates.

[0100] (2) The near-infrared shielding film laminate of the present invention

[0101] In this invention, a glass film capable of heat treatment at 400°C or higher is used instead of plate glass as the substrate. The glass film is continuously conveyed by roller-to-roll, and a composite tungsten oxide film is heated and deposited onto the glass film by methods such as sputtering, or annealing is performed after non-heating film formation, thereby efficiently obtaining the aforementioned glass film with a near-infrared shielding film.

[0102] The near-infrared shielding film laminate of the present invention is composed of a transparent substrate that transmits visible light and a glass film with a near-infrared shielding film laminated on the transparent substrate, as described above.

[0103] Here, as the constituent material of the transparent substrate that transmits visible light, inorganic materials selected from glass or transparent ceramics, and organic materials selected from transparent resin films and resin sheets such as polyethylene terephthalate (PET), polycarbonate, acrylic resin, and polystyrene resin can be used.

[0104] Furthermore, for the near-infrared shielding film laminate of this embodiment, it is preferable to attach the glass film with the near-infrared shielding film and at least one of the bonding surfaces of the transparent substrate that transmits visible light after surface activation.

[0105] Therefore, to activate the bonding surface, it is sufficient to clean at least one surface of the glass film with the near-infrared shielding film and the aforementioned transparent substrate by means of plasma irradiation or ion beam irradiation. Alternatively, it is advantageous to introduce hydroxyl groups into the bonding surface using water adsorbed on the bonding surface by plasma irradiation. Furthermore, it is also advantageous to provide the aforementioned bonding layer on the surface of the near-infrared shielding film of the glass film with the near-infrared shielding film.

[0106] As an example of a bonding method for attaching a glass film with a near-infrared shielding film to the aforementioned transparent substrate, methods such as bonding by applying pressure or bonding by heating in addition to applying pressure can be cited.

[0107] Here, when a method is used to bond a glass film with a near-infrared shielding film to the aforementioned transparent substrate using a commonly known highly transparent optical adhesive or double-sided tape, the bonding reliability of the adhesive or double-sided tape is low, and the glass film with the near-infrared shielding film may peel off from the transparent substrate during long-term use. Therefore, the above-described attachment method is used in this invention.

[0108] (2-1) Near-infrared shielding film laminate without bonding layer

[0109] Figure 2 This diagram illustrates the structure of the glass films 101A and 102A with near-infrared shielding films 103 and 104 formed on one side of the glass films 101 and 102 used as substrates, the transparent substrate 100, and the near-infrared shielding film laminate 100A of this embodiment, in which glass films 101A and 102A with near-infrared shielding films 103 and 104 are bonded to both sides of the transparent substrate 100.

[0110] like Figure 2 As shown, the glass films 101A and 102A with near-infrared shielding films of this embodiment, which have near-infrared shielding films 103 and 104 formed on one side, are bonded to the transparent substrate 100 by the above-described attachment method, thereby obtaining the near-infrared shielding film laminate 100A of this embodiment.

[0111] When polycarbonate is used in the transparent substrate 100, bonding can be performed as long as the Vicat softening temperature is 149°C or higher. Even when applying a temperature of 149°C or higher, it is preferable to expose the active surface of the bonding surface beforehand by passing it through an argon ion beam or similar means. It should be noted that the Vicat softening temperature refers to the temperature at which the thermoplastic begins to soften.

[0112] (2-2) Near-infrared shielding film laminate with bonding layer

[0113] Figure 3 This diagram illustrates the structure of the glass films 201A and 202A with near-infrared shielding films of this embodiment, which use glass films 201 and 202 as substrates and have near-infrared shielding films 203 and 204 and bonding layers 205 and 206 formed on one side thereon; the transparent substrate 200 with bonding layers 207 and 208 formed on both sides; and the near-infrared shielding film laminate 200A of this embodiment, which has the glass films 201A and 202A with near-infrared shielding films bonded to both sides of the transparent substrate 200 via the bonding layers 205, 206, 207, and 208.

[0114] like Figure 3As shown, by attaching the glass films 201A and 202A of this embodiment with near-infrared shielding films formed on one side and bonding layers 205 and 206 formed on the other side, the near-infrared shielding film laminate 200A of this embodiment can be obtained by attaching the glass films 201A and 202A with near-infrared shielding films formed on one side to a transparent substrate 200 with bonding layers 207 and 208 formed on both sides.

[0115] Preferably, the active surfaces of each bonding surface are exposed beforehand by passing an argon ion beam or similar means. As long as the bonding layers 205, 206, 207, and 208, with a thickness of approximately 1–10 nm, are made of insulators such as Al2O3, TiO2, ZrO2, or HfO2, pressure bonding at room temperature is possible. However, to obtain stable bonding strength, slight heating and pressure are preferred. Since the glass films 201A and 202A with near-infrared shielding films are thin and prone to air bubbles, it is preferable to bond them in a vacuum to a transparent substrate 200 made of glass or polycarbonate.

[0116] It should be noted that, Figure 3 The near-infrared shielding film laminate 200A shown in this embodiment has bonding layers 205, 206, 207, and 208 with thicknesses of approximately 1 to 10 nm on the glass films 201A and 202A with near-infrared shielding films and the transparent substrate (e.g., made of float glass or polycarbonate) 200, respectively. Figure 2 Similarly, the near-infrared shielding film laminate 100A shown can be pressure-heated bonded near the softening point temperature without going through the aforementioned bonding layers 205, 206, 207, and 208.

[0117] 4. Method for manufacturing a glass film with a near-infrared shielding film using a roll-to-roll sputtering apparatus

[0118] (1) Method for forming near-infrared shielding film

[0119] Next, the method for forming a near-infrared shielding film composed of composite tungsten oxide that reflects near-infrared light (with a reflectivity of more than 30% under the condition of wavelength 1400nm) will be described in detail below.

[0120] The substrate for forming the near-infrared shielding film composed of composite tungsten oxide uses a flexible strip of glass film instead of the conventional plate glass, and is continuously conveyed by roller-to-roll. Furthermore, considering mass production feasibility, sputtering is preferred for the film-forming method of the composite tungsten oxide constituting the near-infrared shielding film, and the power source can utilize DC power, intermediate frequency power, high frequency power, pulse power, high current pulse power, etc.

[0121] Composite tungsten oxides represented by the general formula MxWyOz (where M is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, and Ti, W is tungsten, O is oxygen, 0.2≤x / y≤0.5, 2.5≤z / y≤3.0) exhibit near-infrared reflectivity by forming a hexagonal crystal structure through film formation under heating conditions above 400℃ or heat treatment after film formation.

[0122] Therefore, a roll-to-roll sputtering apparatus for manufacturing a glass film with a near-infrared shielding film may have at least one of a "film forming process area" for forming a composite tungsten oxide film under heating at a temperature of 400°C or higher, or an "annealing area" for heat treating the film (non-heat-treated film) at a temperature of 400°C or higher. Alternatively, it may have both a "film forming process area" for forming a composite tungsten oxide film under heating at a temperature of 400°C or higher and an "annealing area".

[0123] In addition, in the roll-to-roll sputtering apparatus used to manufacture glass films with near-infrared shielding films, there is a "heater area" for drying the moisture on the surface of the glass film before film formation and the aforementioned "film formation process area" for forming composite tungsten oxide films.

[0124] Furthermore, if the temperature in the "film formation process area" is less than 400°C, the composite tungsten oxide film (non-heat-treated film) needs to be heat-treated (heat treatment process) in the aforementioned "annealing area".

[0125] The following uses Figure 4 and Figure 5 The roller-to-roll sputtering apparatus shown describes the process of forming a composite tungsten oxide film, represented by the general formula MxWyOz, onto a strip of glass film.

[0126] It should be noted that, in Figure 4 and Figure 5 The diagram does not include the exhaust system pump or the inlet mechanism for the reactant gases. Additionally, to remove moisture detached from the interior walls, installing a low-temperature coil or plate to cause condensation at low temperatures is effective.

[0127] (2) Roll-to-roll sputtering device for winding a glass film with a near-infrared shielding film into a roll shape

[0128] like Figure 4 As shown, the roll-to-roll sputtering apparatus for manufacturing a glass film with a near-infrared shielding film and winding it into a roll includes an unwinding area 302, a conveying area 303, a heater area 304, a conveying area 305, a surface treatment area 306, a film forming process area 307, an annealing area 308, a conveying and cooling area 309, and a winding area 310.

[0129] It should be noted that the pressure can be adjusted by setting relative slit rolls between each region and introducing argon gas or the like into each region. Furthermore, the unwinding region 302 mentioned above corresponds to the "glass film unwinding process" in the manufacturing method of the glass film with a near-infrared shielding film of the present invention.

[0130] Here, when explaining the reference numerals for each roller, "F" refers to a free roller that rotates without driving force by conveying the glass film, "T" is the shaft of the free roller or a tension roller with a tension sensor inside, and "M" is a motor-driven roller whose rotation is controlled by a motor. These roller configurations show a necessary minimum example and are not limited to these roller configurations. For ease of winding, the carrier film (liner film) 301 is usually attached to the glass film 300.

[0131] First, a glass film 300A with a carrier film is placed on a glass film unwinding roller 311 with a carrier film in the unwinding area 302. The carrier film (liner film) 301 is wound onto a carrier film winding roller 312 via a free roller 314. In order to allow the glass film 300 to pass through the roller-to-roll sputtering device, the glass film 300 is usually connected to a guide film that has been pre-passed through the conveying path and stretched.

[0132] After setting the glass membrane 300A with the carrier film, vacuum evacuation begins. Generally, a dry pump is used for rough evacuation, followed by multiple turbomolecular pumps to achieve a high vacuum. Using a cryogenic tube is effective in removing moisture.

[0133] A glass film 300A with a carrier film is peeled off from the glass film 300A via a contact roller 313, which prevents the glass film 300A from wobbling as it is unwound from the glass film unwinding roller 311 with the carrier film, in front of a free roller 314. The carrier film 301 is then wound onto a carrier film winding roller 312 as described above. The glass film 300 with the carrier film (liner) 301 peeled off enters the transport area 303 via a tension roller 315, which measures the unwinding tension. The unwinding tension is detected by the tension roller 315, and adjusted by balancing the motor-driven roller 316 with the glass film unwinding roller 311 with the carrier film.

[0134] The glass film 300, which is moved into the conveying area 303, is conveyed into the heater area 304 via the motor-driven roller 316, free rollers 317 and 318, and tension roller 319. Here, the conveying tension is detected by the tension roller 319, and the conveying tension of the heater area 304 is adjusted by the motor-driven roller 328.

[0135] The glass film 300, fed into heater region 304, passes between heaters 320, 321, 322, and 323 via free rollers 324, 325, 326, and 327, and enters conveying region 305. The aforementioned heaters need to irradiate wavelengths that absorb the glass film; for example, carbon heaters, mid-wave infrared heaters, and SiC heaters can be used. The heater temperature is maintained by using a thermocouple or other thermometer to perform proportional-integral-derivative (PID) control on the current value.

[0136] The glass film 300, which is transported into the conveying area 305, is conveyed into the surface treatment area 306 via the motor-driven roller 328, free rollers 329 and 330, and tension roller 331. Here, the conveying tension is detected by the tension roller 331, and the conveying tension of the surface treatment area 306 is adjusted by the motor-driven roller 335.

[0137] The glass film 300, transported into the surface treatment area 306, enters the film formation process area 307 via a free roller 334 and a motor-driven roller 335 in front of the surface treatment apparatuses 332 and 333. The surface treatment apparatus can use ion beams and plasma, etc.

[0138] The glass film 300, fed into the film-forming process area 307, enters the annealing area 308 via tension roller 345, free roller 346, process roller 336, free roller 347, and tension roller 348. The tension of the glass film 300 entering the process roller 336 is detected by tension roller 345 and adjusted by balancing the rotational speeds of the motor-driven roller 335 and the process roller 336. On the other hand, the tension of the glass film 300 exiting the process roller 336 is detected by tension roller 348 and adjusted by balancing the rotational speeds of the motor-driven roller 353 and the process roller 336.

[0139] Sputtering cathodes 337, 338, 339, 340, 341, 342, 343, and 344 are arranged around the process roller 336. This sputtering cathode assembly can be flat or cylindrical. Sputtering gas (argon) and the gas required for reactive sputtering (oxygen) are guided to each sputtering cathode via flow meters. The process roller 336 and the sputtering cathodes constitute the film formation process area 307.

[0140] The glass film 300, fed into the annealing zone 308, passes between heaters 349, 350, 351, and 352 via motor-driven rollers 353 and free rollers 354, 355, and 356, and enters the conveying and cooling zone 309. Heaters 349, 350, 351, and 352 constitute the annealing zone. At least heater 349 needs to irradiate the glass film with a wavelength that absorbs it; for example, a carbon heater, a mid-wave infrared heater, or a SiC heater, which emits infrared radiation with wavelengths above 1500 nm, can be used. If the composite tungsten oxide begins to crystallize, it begins to absorb near-infrared radiation, promoting crystallization and becoming a reflective film. During the absorption of near-infrared radiation, it can become a near-infrared heater with high energy density. Specifically, halogen heaters can be configured in heaters 351 and 352. The heater temperature can be maintained by PID control of the current value using a thermocouple or other thermometer to maintain the set temperature. Alternatively, the required gas can be introduced during annealing.

[0141] It should be noted that when using a roll-to-roll sputtering device to continuously perform annealing after the formation of a composite tungsten oxide film, the glass film's conveying speed is also related to the time it spends in the annealing zone 308. Therefore, a sufficient time needs to be set for the composite tungsten oxide to crystallize. Alternatively, after forming the composite tungsten oxide film on the glass film using a roll-to-roll sputtering device, it can be further annealed using other vacuum annealing devices or nitrogen / argon / reducing environment annealing devices.

[0142] Here, tension roller 357 is used to detect the conveying tension and cooling roller 360 is driven by a motor to adjust the conveying tension of the conveying cooling zone 309.

[0143] The glass film 300, which is transported into the conveying and cooling area 309, is fed into the winding area 310 via tension rollers 357, free rollers 358 and 359, and motor-driven cooling rollers 360. The motor-driven cooling rollers 360 are used to cool the glass film after film formation and annealing to prevent it from becoming too tight during cooling after winding. Depending on the needs, the number of motor-driven cooling rollers 360 may be increased to allow for slower cooling of the glass film.

[0144] The glass film 300, fed into the winding area 310, is bonded to the carrier film 364, which is unwound from the carrier film unwinding roller 362, on the free roller 365 via the tension roller 363. During winding, it is wound onto the winding roller 361 via the contact roller 366, which prevents the film from shaking. The winding tension is detected by the tension roller 363, and adjusted by the motor-driven balance between the cooling roller 360 and the winding roller 361.

[0145] (3) A roller-to-roll sputtering device that cuts (slits) glass films with near-infrared shielding films into sheets.

[0146] like Figure 5 As shown, the roll-to-roll sputtering apparatus for cutting (cutting) glass films with near-infrared shielding films into sheets includes an unwinding area 402, a conveying area 403, a heater area 404, a conveying area 405, a surface treatment area 406, a film forming process area 407, an annealing area 408, a conveying cooling area 409, a tension adjustment area 410, a differential venting area 464, and a cutting (cutting) area 467.

[0147] It should be noted that the pressure can also be adjusted by setting relative slit rollers between each area and introducing argon gas into each area. Furthermore, the reference numerals for each roller are explained: "F" is a free roller that rotates without driving force and is conveyed by the glass film; "T" is the shaft of the free roller or a tension roller with a tension sensor inside; and "M" is a motor-driven roller whose rotation is controlled by a motor. These roller configurations show an example of the necessary minimum and are not limited to these configurations. For ease of winding, the carrier film (liner film) 401 is usually bonded to the glass film 400.

[0148] First, a glass film 400A with a carrier film is placed on a glass film unwinding roller 411 with a carrier film in the unwinding area 402. The carrier film (liner film) 401 is wound onto a carrier film winding roller 412 via a free roller 414. In order to allow the glass film 400 to pass through the roller-to-roll sputtering device, the method of connecting the glass film 400 to a guide film that has been pre-passed through the conveying path and stretching it is mostly adopted.

[0149] After setting the glass membrane 400A with the carrier film as described above, vacuum evacuation begins. Generally, a dry pump is used for rough evacuation, followed by multiple turbomolecular pumps to achieve a high vacuum. Using a cryogenic tube is effective in removing moisture.

[0150] A glass film 400A with a carrier film is peeled off from the glass film 400A via a contact roller 413, which prevents the glass film 400A from wobbling as it is unwound from the glass film unwinding roller 411 with the carrier film, in front of a free roller 414. The carrier film 401 is then wound onto a carrier film winding roller 412 as described above. The glass film 400 with the carrier film (liner) 401 peeled off enters the transport area 403 via a tension roller 415, which measures the unwinding tension. The unwinding tension is detected by the tension roller 415 and adjusted by balancing the motor-driven roller 416 with the glass film unwinding roller 411 with the carrier film.

[0151] The glass film 400, which is transported into the conveying area 403, is conveyed into the heater area 404 via the motor-driven roller 416, free rollers 417 and 418, and tension roller 419. Here, the conveying tension is detected by the tension roller 419 and the conveying tension of the heater area 404 is adjusted by the motor-driven roller 428.

[0152] The glass film 400, fed into heater region 404, passes between heaters 420, 421, 422, and 423 via free rollers 424, 425, 426, and 427, and enters conveying region 405. The aforementioned heaters need to irradiate the glass film with an absorbent wavelength; for example, carbon heaters, mid-wave infrared heaters, and SiC heaters can be used. The heater temperature is maintained by PID control of the current value using thermocouples or other thermometers.

[0153] The glass film 400, which is transported into the conveying area 405, is conveyed into the surface treatment area 406 via the motor-driven roller 428, free rollers 429 and 430, and tension roller 431. Here, the conveying tension is detected by the tension roller 431, and the conveying tension of the surface treatment area 406 is adjusted by the motor-driven roller 435.

[0154] The glass film 400, fed into the surface treatment area 406, enters the film formation process area 407 in front of the surface treatment apparatuses 432 and 433 via a free roller 434 and a motor-driven roller 435. The surface treatment apparatus can use ion beams and plasma, etc.

[0155] The glass film 400, fed into the film-forming process area 407, enters the annealing area 408 via tension roller 445, free roller 446, process roller 436, free roller 447, and tension roller 448. The tension of the glass film 400 entering the process roller 436 is detected by tension roller 445 and adjusted by balancing the rotational speeds of the motor-driven roller 435 and the process roller 436. On the other hand, the tension of the glass film 400 exiting the process roller 436 is detected by tension roller 448 and adjusted by balancing the rotational speeds of the motor-driven roller 453 and the process roller 436.

[0156] Sputtering cathodes 437, 438, 439, 440, 441, 442, 443, and 444 are arranged around the process roller 436. This sputtering cathode assembly can be flat or cylindrical. Sputtering gas (argon) and the gas required for reactive sputtering (oxygen) are guided to each sputtering cathode via flow meters. The process roller 436 and the sputtering cathodes constitute the film formation process area 407.

[0157] The glass film 400, fed into the annealing zone 408, passes between heaters 449, 450, 451, and 452 via motor-driven rollers 453 and free rollers 454, 455, and 456, and enters the conveying and cooling zone 409. Heaters 449, 450, 451, and 452 constitute the annealing zone. At least heater 449 needs to irradiate the glass film with a wavelength that absorbs it; for example, a carbon heater, a mid-wave infrared heater, or a SiC heater, which emits infrared radiation with wavelengths above 1500 nm, can be used. If the composite tungsten oxide begins to crystallize, it begins to absorb near-infrared radiation, promoting crystallization and becoming a reflective film. During the absorption of near-infrared radiation, it can become a near-infrared heater with high energy density. Specifically, halogen heaters can be configured in heaters 451 and 452. The temperature of the heaters is maintained by PID control of the current value using thermocouples or other thermometers. Alternatively, the required gas can be introduced during annealing.

[0158] It should be noted that when annealing the composite tungsten oxide film continuously using a roll-to-roll sputtering device, the glass film's conveying speed is also related to the time it remains in the annealing zone 408. Therefore, it needs to be set to allow sufficient time for the composite tungsten oxide to crystallize. Alternatively, after the composite tungsten oxide film is formed on the glass film using a roll-to-roll sputtering device, it can be annealed separately using other vacuum annealing devices or nitrogen / argon / reducing environment annealing devices.

[0159] Here, the tension roller 457 is used to detect the conveying tension, and the cooling roller 460 driven by the motor is used to adjust the conveying tension of the conveying cooling zone 409.

[0160] The glass film 400, after being conveyed into the cooling zone 409, enters the tension adjustment zone 410 via the tension rollers 457, free rollers 458 and 459, and motor-driven cooling rollers 460. The motor-driven cooling rollers 460 are used to cool the film after film formation and annealing to prevent it from becoming too tight during cooling after winding. Depending on the needs, the number of motor-driven cooling rollers 460 may be increased to allow for slower cooling of the glass film.

[0161] The glass film 400, which is fed into the tension adjustment area 410, enters the differential venting area 464 via the free roller 461, the floating roller 462, and the tension roller 463. When the glass film is cut after film formation, the glass film is intermittently stopped from being transported. Therefore, at this time, the tension roller 463 is used to detect the transport tension and the position of the floating roller 462 is adjusted up and down to maintain the set tension.

[0162] The glass film 400 enters the cutting zone 467 through the core-type seals (hollow seals) 465 and 466 located before and after the differential exhaust zone 464. Film formation and conveying are stopped, and the formed glass film is clamped in these core-type seals (hollow seals) 465 and 466, so that even without opening the vacuum of the main body of the roller-to-roll sputtering device to the atmosphere, it is possible to remove the cut glass film, i.e., the glass film with the near-infrared shielding film.

[0163] The glass film 400 is held by motor-driven rollers 468 and clamping rollers 469, and is cut, for example, by a laser beam 471 irradiated from a laser device 470, into sheet-like glass films 473 with near-infrared shielding films, which are then stacked on a tray 472. A backing film may also be inserted during the stacking of the glass films 473 with near-infrared shielding films. Cutting can be performed by intermittently stopping the film, or by scanning the beam position at an angle corresponding to the conveying speed.

[0164] 5. Manufacturing method of near-infrared shielding film laminate

[0165] The near-infrared shielding film laminate of the present invention is composed of a transparent substrate that transmits visible light and a glass film with a near-infrared shielding film laminated on the transparent substrate, as described above.

[0166] Here, the aforementioned transparent substrate refers to a substrate with a visible light transmittance of 5% or higher. If the visible light transmittance of the transparent substrate is 5% or higher, then even if it is difficult to observe the interior from the outside, it is still possible to visually identify the outside from the inside.

[0167] (1) A long strip of glass film with a near-infrared shielding film

[0168] Figure 6 This is a process illustration diagram showing the process of continuously bonding long strips of glass films 501 and 502 with near-infrared shielding films to two sides of a transparent substrate 500 to manufacture a near-infrared shielding film laminate 515.

[0169] That is, both sides of the transparent substrate 500 can be activated in a vacuum using ion beam or plasma processing devices 504 and 506, and one side of the glass films 501 and 502 with near-infrared shielding films can be activated using ion beam or plasma processing devices 503 and 505; or both sides of the transparent substrate 500 can be activated in the atmosphere using atmospheric pressure plasma processing or corona treatment devices 504 and 506, and the atmospheric pressure plasma processing or corona treatment devices 503 and 505 can be activated. 5. One side of the glass films 501 and 502 with near-infrared shielding films is activated to expose each activated side. Then, the long strips of glass films 501 and 502 with near-infrared shielding films are guided to the two sides of the transparent substrate 500 by guide rollers 507, 508, 509 and 510. The glass films 501 and 502 with near-infrared shielding films are bonded to the two sides of the transparent substrate 500 by rotating hot rollers 511, 512, 513 and 514 with controlled temperature to manufacture a near-infrared shielding film laminate 515.

[0170] It should be noted that, Figure 6 The near-infrared shielding film laminate 515 shown has a structure in which glass films 501 and 502 with near-infrared shielding films are bonded to both sides of the transparent substrate 500. As long as the optical characteristics are met, it can be configured to have a structure in which a glass film with near-infrared shielding film is bonded to only one side of the transparent substrate 500.

[0171] (2) Cut (severed) glass film with near-infrared shielding film

[0172] Figure 7 This is a process illustration diagram showing the process of bonding cut (slit) glass films 601 and 602 with near-infrared shielding films to two sides of a transparent substrate 600 to manufacture a near-infrared shielding film laminate 606.

[0173] That is, the two sides of the transparent substrate 600 can be activated in a vacuum using an ion beam or plasma treatment device, and one side of the glass films 601 and 602 with near-infrared shielding films can be activated using an ion beam or plasma treatment device, or the two sides of the transparent substrate 600 can be activated in the atmosphere using an atmospheric pressure plasma treatment or corona treatment device, and the activated side of the glass films 601 and 602 with near-infrared shielding films can be activated using an atmospheric pressure plasma treatment or corona treatment device to expose each activated side, and the structure with glass films 601 and 602 with near-infrared shielding films overlapping on the two sides of the transparent substrate 600 is arranged on a hot plate 603 with controlled temperature, and the glass films 601 and 602 with near-infrared shielding films are bonded to the two sides of the transparent substrate 600 using rotating hot rollers 604 and 605 with controlled temperature and the hot plate 603 to manufacture a near-infrared shielding film laminate 606.

[0174] It should be noted that, in Figure 7 In the near-infrared shielding film laminate 606 shown, it can also be a structure in which glass films 601 and 602 with near-infrared shielding films are bonded to both sides of the transparent substrate 600. As long as the optical characteristics are met, it can be configured to have a structure in which a glass film with near-infrared shielding film is bonded to only one side of the transparent substrate 600.

[0175] Furthermore, the aforementioned near-infrared shielding film laminate, composed of a transparent substrate that transmits visible light and a glass film with a near-infrared shielding film, can be used as a transparent thermal reflective component that reflects light in the near-infrared region for applications such as windows in automobiles and buildings.

[0176] Example

[0177] The embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0178] (1) Measurement method

[0179] (1-1) Surface resistance

[0180] The surface resistivity of the membrane was measured using the Loresta-GX manufactured by Mitsubishi Chemical Co., Ltd.

[0181] (1-2) Film thickness

[0182] Film thickness was measured using an optical profilometer (NewView 6200, manufactured by Zygo Corporation, USA).

[0183] (1-3) Maximum transmittance in the visible light region and reflectance at a wavelength of 1400 nm

[0184] The optical properties of the obtained film were determined using a spectrophotometer V-670 (manufactured by JASCO Corp., Japan) to measure the transmittance and 8° incident diffusion reflectance.

[0185] Furthermore, based on the measurement results, the highest transmittance value in the visible light region (wavelength above 380nm and below 780nm) was determined.

[0186] [Examples 1-10]

[0187] (Target manufacturing process)

[0188] A cesium carbonate aqueous solution and tungsten trioxide hydrate were mixed and kneaded at a molar ratio of cesium (Cs) to tungsten (W) of Cs / W = 0.33, and then dried in the atmosphere at 100°C for 12 hours to prepare a precursor.

[0189] The above precursor was heated to 800°C in a gas flow of 5% H2 to 95% N2 and held for 1 hour, then gradually cooled to room temperature to obtain a dark blue composite tungsten oxide powder (hereinafter referred to as CsWO powder).

[0190] The CsWO powder was placed into a hot pressing device and pressed under vacuum conditions at a temperature of 950°C and a pressure of 250 kgf / cm². 2 CsWO sintered bodies were produced by sintering under the specified conditions.

[0191] The chemical analysis of the sintered body showed that the molar ratio of Cs to W, i.e., Cs / W, was 0.33.

[0192] The oxide sintered body is ground into a diameter of 20 mm and a thickness of 4 mm by mechanical processing to manufacture CsWO target sheets.

[0193] (Film forming process)

[0194] In the film-forming process, using Figure 4 The roller-to-roll sputtering device shown.

[0195] The glass film 300 has a thickness of 50μm, a width of 500mm, and a length of 100m.

[0196] Eight cathodes are arranged around the process roller 336, from the first cathode 337 to the sixth cathode 342, and the aforementioned Cs are mounted thereon for forming the near-infrared shielding film. 0.33 WO3 powder is used as a target for raw materials.

[0197] The seventh cathode 343 and the eighth cathode 344 are fitted with metal oxide targets for forming the bonding layers described in Tables 2-1 to 2-2. However, in Examples 7 to 10, no metal oxide targets were fitted. Even when using metal oxide targets to supplement insufficient oxygen during the formation of the bonding layer, the oxygen partial pressure in the film is controlled at 2 Pa.

[0198] Each target is grouped into two, and a dual magnetron sputtering method based on a 40Hz mid-frequency pulse power supply is used. By controlling the amount of inserted oxygen to ensure that the voltage or current value of the mid-frequency pulse power supply in this dual magnetron sputtering method is within a specified range, an oxide film can be obtained at a film formation rate close to that of the metal mode through a transitional mode between the metal mode (fast film formation but insufficient oxidation) and the oxide mode (slow film formation).

[0199] In addition, the temperature of the process roller 336 is controlled at 200°C by a heat medium.

[0200] Through a series of operations, the unheat-treated films and bonding layers of Examples 1 to 10 are formed into films.

[0201] (Heat treatment process)

[0202] In this embodiment, since the glass film 300 with a non-heat-treated film formed in the 3m annealing region 308 is kept for 6 minutes, the conveying speed of the glass film 300 is 0.5m / min, and the temperature in the annealing region 308 is controlled at 600°C.

[0203] Heaters 349 and 350 in annealing zone 308 are SiC heaters, while heaters 351 and 352 are halogen heaters.

[0204] After the glass film 300 with a near-infrared shielding film is cooled by the motor-driven cooling roller 360 in the annealing zone 308, it is wound onto the winding roller 361. In addition, the carrier film (liner film) 364 used when the glass film 300 with a near-infrared shielding film is wound onto the winding roller 361 is a PET film.

[0205] (Lamination process)

[0206] (1) Examples 1-6

[0207] Under the bonding conditions shown in Tables 2-1 and 2-2 (presence or absence of bonding layer, environment, surface treatment, bonding temperature, bonding pressure, one side or both sides), the film thicknesses shown in Tables 1-1 and 1-2 are applied to composite tungsten oxide (Cs) 0.33 The near-infrared shielding film laminates of Examples 1 to 6 are manufactured by bonding a glass film with a near-infrared shielding film composed of WO3 to a 3mm thick float glass (plate glass) substrate via an bonding layer.

[0208] (2) Examples 7-8

[0209] Under the bonding conditions shown in Tables 2-1 and 2-2 (presence or absence of bonding layer, environment, surface treatment, bonding temperature, bonding pressure, one side or both sides), the film thicknesses shown in Tables 1-1 and 1-2 are applied to composite tungsten oxide (Cs) 0.33 The near-infrared shielding film laminates of Examples 7-8 are manufactured by bonding a glass film with a near-infrared shielding film (WO3) to a 3mm thick float glass substrate (plate glass) without a bonding layer.

[0210] (3) Examples 9-10

[0211] Under the bonding conditions shown in Tables 2-1 and 2-2 (presence or absence of bonding layer, environment, surface treatment, bonding temperature, bonding pressure, one side or both sides), the film thicknesses shown in Tables 1-1 and 1-2 are applied to composite tungsten oxide (Cs) 0.33 The near-infrared shielding film laminates of Examples 9-10 are manufactured by bonding a glass film with a near-infrared shielding film (WO3) to a 3mm thick polycarbonate plate without a bonding layer.

[0212] (4) Optical properties and surface resistivity

[0213] The optical properties (highest transmittance in the visible wavelength region and reflectance at a wavelength of 1400 nm) and surface resistivity of the near-infrared shielding films and near-infrared shielding film laminates of Examples 1 to 10 were measured.

[0214] Record the results in Tables 2-1 to 2-2.

[0215] (evaluate)

[0216] The near-infrared shielding film laminates of Examples 1-10 were confirmed to have a maximum transmittance of 5% or more in the visible wavelength region and a reflectance of 30% or more at a wavelength of 1400 nm. Furthermore, the surface resistivity of the near-infrared shielding film has a value of 10... 5 Characteristics of Ω / □ or higher.

[0217] Furthermore, the use of the glass film with near-infrared shielding film in the near-infrared shielding film laminate of Examples 1-10 was also confirmed. Figure 4 The roller-to-roll sputtering apparatus shown is manufactured efficiently, achieving cost reduction for near-infrared shielding film laminates.

[0218] Table 1-1

[0219] Table 1-2

[0220] Table 2-1

[0221] Table 2-2

[0222] Industrial applicability

[0223] According to the method of the present invention, the substrate on which the near-infrared shielding film composed of composite tungsten oxide is formed is made of glass film with a thickness of less than 200 μm. The glass film can be made into a roller shape and continuously conveyed by roller-to-roll. Therefore, it is possible to efficiently manufacture composite tungsten oxide film that functions as a heat shielding film. Thus, it has industrial applicability for use in windows of automobiles and buildings that require heat shielding and electromagnetic wave transmittance.

[0224] Explanation of reference numerals in the attached figures

[0225] 10: Plate glass.

[0226] 11, 12: Near-infrared shielding film.

[0227] 100: Transparent substrate.

[0228] 100A: Near-infrared shielding film laminate.

[0229] 101, 102: Glass film.

[0230] 101A, 102A: Glass films with near-infrared shielding film.

[0231] 103, 104: Near-infrared shielding film.

[0232] 200: Transparent substrate.

[0233] 200A: Near-infrared shielding film laminate.

[0234] 201, 202: Glass film.

[0235] 201A, 202A: Glass film with near-infrared shielding film.

[0236] 203, 204: Near-infrared shielding film.

[0237] 205, 206: Bonding layer.

[0238] 207, 208: Bonding layer.

[0239] 300: Glass film.

[0240] 300A: Glass film with a carrier film.

[0241] 301: Carrier membrane (liner membrane).

[0242] 302: Unwinding area.

[0243] 303: Delivery area.

[0244] 304: Heater area.

[0245] 305: Transport area.

[0246] 306: Surface treated area.

[0247] 307: Film-forming process area.

[0248] 308: Annealing zone.

[0249] 309: Conveying cooling area.

[0250] 310: Winding area.

[0251] 311: Glass film unwinding roller with carrier film.

[0252] 312: Carrier film winding roller.

[0253] 313: Contact roller.

[0254] 314: Free roller.

[0255] 315: Tension roller.

[0256] 316: Motor-driven roller.

[0257] 317, 318: Free rollers.

[0258] 319: Tension roller.

[0259] 320, 321, 322, 323: Heaters.

[0260] 324, 325, 326, 327: Free rollers.

[0261] 328: Motor-driven roller.

[0262] 329, 330: Free rollers.

[0263] 331: Tension roller.

[0264] 332, 333: Surface treatment apparatus.

[0265] 334: Free roller.

[0266] 335: Motor-driven roller.

[0267] 336: Process roller.

[0268] 337, 338, 339, 340, 341, 342, 343, 344: Sputtered cathodes.

[0269] 345: Tension roller.

[0270] 346: Free roller.

[0271] 347: Free roller.

[0272] 348: Tension roller.

[0273] 349, 350, 351, 352: Heaters.

[0274] 353: Drive roller.

[0275] 354, 355, 356: Free rollers.

[0276] 357: Tension roller.

[0277] 358, 359: Free rollers.

[0278] 360: Motor drives the cooling roller.

[0279] 361: A glass film winding roller with a near-infrared shielding film and a carrier film.

[0280] 362: Carrier film unwinding roller.

[0281] 363: Tension roller.

[0282] 364: Carrier membrane.

[0283] 365: Free roller.

[0284] 366: Contact roller.

[0285] 400: Glass film.

[0286] 400A: Glass film with a carrier film.

[0287] 401: Carrier membrane (liner membrane).

[0288] 402: Unwinding area.

[0289] 403: Delivery area.

[0290] 404: Heater area.

[0291] 405: Transport area.

[0292] 406: Surface treated area.

[0293] 407: Film forming process area.

[0294] 408: Annealing zone.

[0295] 409: Conveying cooling area.

[0296] 410: Tension adjustment area.

[0297] 411: Glass roll unwinding roller with carrier film.

[0298] 412: Carrier film winding roller.

[0299] 413: Contact roller.

[0300] 414: Free roller.

[0301] 415: Tension roller.

[0302] 416: Motor-driven roller.

[0303] 417, 418: Free rollers.

[0304] 419: Tension roller.

[0305] 420, 421, 422, 423: Heaters.

[0306] 424, 425, 426, 427: Free rollers.

[0307] 428: Motor-driven roller.

[0308] 429, 430: Free rollers.

[0309] 431: Tension roller.

[0310] 432, 433: Surface treatment apparatus.

[0311] 434: Free roller.

[0312] 435: Motor-driven roller.

[0313] 436: Process roller.

[0314] 437, 438, 439, 440, 441, 442, 443, 444: Sputtered cathodes.

[0315] 445: Tension roller.

[0316] 446: Free roller.

[0317] 447: Free roller.

[0318] 448: Tension roller.

[0319] 449, 450, 451, 452: Heaters.

[0320] 453: Drive roller.

[0321] 454, 455, 456: Free rollers.

[0322] 457: Tension roller.

[0323] 458, 459: Free rollers.

[0324] 460: Motor drives the cooling roller.

[0325] 461: Free roller.

[0326] 462: Floating roller.

[0327] 463: Tension roller.

[0328] 464: Differential exhaust area.

[0329] 465, 466: Macaroni-type seals (hollow seals).

[0330] 467: Cutting (severing) area.

[0331] 468: Motor-driven roller.

[0332] 469: Clamping roller.

[0333] 470: Laser device.

[0334] 471: Laser beam.

[0335] 472: Tray.

[0336] 473: A glass film with a near-infrared shielding film cut into sheets.

[0337] 500: Transparent substrate.

[0338] 501, 502: Glass films with near-infrared shielding film.

[0339] 503, 504, 505, 506: Ion beam or plasma treatment device or atmospheric pressure plasma treatment or corona treatment device in the atmosphere.

[0340] 507, 508, 509, 510: Guide rollers.

[0341] 511, 512, 513, 514: Hot rollers.

[0342] 515: Near-infrared shielding film laminate.

[0343] 600: Transparent substrate.

[0344] 601, 602: Glass films with near-infrared shielding film.

[0345] 603: Hot plate.

[0346] 604, 605: Hot rollers.

[0347] 606: Near-infrared shielding film laminate.

Claims

1. A glass film with a near-infrared shielding film, characterized in that, The glass film with near-infrared shielding film is composed of a glass film with a thickness of less than 200 μm and a near-infrared shielding film. The near-infrared shielding film is formed on at least one side of the glass film. The near-infrared shielding film is composed of a composite tungsten oxide, which is represented by the general formula MxWyOz and has a hexagonal crystal structure. M is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, and Ti, W is tungsten, O is oxygen, and 0.2 ≤ x / y ≤ 0.5, 2.5 ≤ z / y ≤ 3.

0. The near-infrared shielding film has a maximum transmittance of 5% or more in the visible light region with wavelengths above 380nm and below 780nm, and the near-infrared shielding film has a reflectance of 30% or more at a wavelength of 1400nm.

2. The glass film with a near-infrared shielding film as described in claim 1, characterized in that, The thickness of the near-infrared shielding film is greater than 10 nm and less than 500 nm.

3. The glass film with a near-infrared shielding film as described in claim 1 or 2, characterized in that, The surface resistivity of the near-infrared shielding film is 10. 5 Ω / □ and above.

4. The glass film with a near-infrared shielding film as described in claim 1, characterized in that, A bonding layer is formed on the surface of the near-infrared shielding film.

5. The glass film with a near-infrared shielding film as described in claim 4, characterized in that, The bonding layer is composed of oxides selected from SiO2, Al2O3, ZrO2, TiO2, and HfO2.

6. A near-infrared shielding film laminate, characterized in that, The near-infrared shielding film laminate is composed of a transparent substrate that transmits visible light and a glass film with a near-infrared shielding film as described in claim 1 or 4, laminated on the transparent substrate.

7. The near-infrared shielding film laminate as described in claim 6, characterized in that, The transparent substrate is made of an inorganic material selected from glass and transparent ceramics, or of an organic material selected from resin films and resin plates.

8. A method for manufacturing a glass film with a near-infrared shielding film, which is the method for manufacturing a glass film with a near-infrared shielding film as described in claim 1, characterized in that, The manufacturing method has the following characteristics: The glass film unwinding process is used to unwind glass films with a thickness of less than 200μm that are wound on the unwinding roller. The film-forming process involves simultaneously conveying the glass film unwound from the unwinding roller via a roller-to-roll method, and simultaneously forming a composite tungsten oxide film, represented by the general formula MxWyOz, onto at least one surface of the glass film using a film-forming mechanism. M is one or more elements selected from K, Rb, Cs, Na, Sr, Ba, and Ti; W is tungsten; O is oxygen; and the following conditions apply: 0.2 ≤ x / y ≤ 0.5, 2.5 ≤ z / y ≤ 3.

0. The heat treatment process involves heat-treating the glass film containing composite tungsten oxide at a temperature below the strain point of the glass film to form a near-infrared shielding film composed of composite tungsten oxide with a hexagonal crystal structure.

9. The method for manufacturing a glass film with a near-infrared shielding film as described in claim 8, characterized in that, In the heat treatment process, a plurality of heat treatment units are used to sequentially heat treat the glass film with composite tungsten oxide film, and the initial heat treatment unit is composed of an infrared heater that emits infrared rays with a wavelength of 1500 nm or higher.

10. The method for manufacturing a glass film with a near-infrared shielding film as described in claim 9, characterized in that, The initial heat treatment mechanism consists of a carbon heater or a SiC heater.

11. A method for manufacturing a near-infrared shielding film laminate, which is the method for manufacturing the near-infrared shielding film laminate according to claim 6, characterized in that, The manufacturing method includes a hot-pressing step, in which the glass film with near-infrared shielding film as described in claim 1 or 4 is hot-pressed with the transparent substrate made of organic material as described in claim 7.

12. A method for manufacturing a near-infrared shielding film laminate, which is the method for manufacturing the near-infrared shielding film laminate as described in claim 6, characterized in that, The manufacturing method has the following characteristics: A surface activation process, wherein the surface of at least one of the glass film with near-infrared shielding film as described in claim 1 or 4 and the transparent substrate made of inorganic material as described in claim 7 is activated. as well as The bonding process involves bonding the glass film with a near-infrared shielding film to a transparent substrate via an activated surface.

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