Glass film with near-infrared blocking film, near-infrared blocking film laminate, method for manufacturing glass film with near-infrared blocking film, and method for manufacturing near-infrared blocking film laminate

Abstract

To provide: a method by which it is possible to efficiently manufacture a composite tungsten oxide film (electrically insulating heat ray blocking film); and a glass film with a near infrared blocking film obtained by the method.SOLUTION: Glass films 101A, 102A with near-infrared blocking films are characterized by comprising: glass films 101, 102 having a thickness of 200 μm or less; and near-infrared blocking films 103, 104 formed on one surface of the glass films and comprising a composite tungsten oxide having a hexagonal crystal structure represented by the general formula MxWyOz. The glass films 101A, 102A are also characterized in that: the maximum value of transmittance of the near-infrared blocking film, in a visible light region of a wavelength from 380 nm to 780 nm, is 5% or more; and the reflectance of the near-infrared blocking film at a wavelength of 1400 nm is 30% or more. Further, a near-infrared blocking film laminate 100A formed by joining the glass film with the near-infrared blocking film to a plate glass 100, or the like, can be used for a window of an automobile or a building for which heat ray blocking properties and radio wave transmissivity are required.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a glass film with a near-infrared shielding film and a near-infrared shielding film laminate that transmit light in the visible wavelength range and reflect and shield light in the near-infrared range, and to 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 members such as glass sheets provided with a film that transmits visible light and blocks near-infrared rays that become heat rays are used as windows for automobiles, windows for buildings, etc. Such window members are provided with a near-infrared shielding film on the surface of a transparent substrate such as glass sheets, in which an infrared absorbing material microparticle dispersion is disposed, in which infrared absorbing material microparticles such as cesium tungsten bronze are dispersed in a resin that is transparent to visible light. Patent Document 1 discloses an infrared absorbing material microparticle dispersion in which composite tungsten oxide particles are dispersed in a medium such as a resin.

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

[0004] Therefore, instead of the coating method, there is a technique for forming a near-infrared shielding film by forming a film of a near-infrared shielding material on a glass plate by sputtering, etc. Patent Document 2 discloses an infrared reflective film in which a plurality of metal layers made of different metals formed by sputtering and a dielectric layer are laminated.

[0005] However, when a metal is formed into a film by sputtering, the film becomes conductive, and when used as a window material, it blocks radio waves between indoors and outdoors. Radio and FM radio waves are in the VHF band (30MHz-0.3GHz). Radio waves for mobile phones and mobile communications belong to the UHF band (0.3GHz-3GHz). Particularly useful radio waves for communication are in the 0.9GHz to 2.2GHz band, and radio waves used for wireless LAN (wireless local area network) are in the 2.45GHz and 5.2GHz bands. Technology development is being carried out for the SHF band (3GHz-30GHz) with even shorter wavelengths for high-speed data communication and satellite communication. Radio waves in these frequency bands are preferably transparent. However, infrared reflective films (heat ray reflective films) made of metallic thin films reflect radio waves in the GHz and MHz bands used for these signal transmissions, so measures must be taken, such as providing a cutout in part of the film.

[0006] The reflectivity of radio waves in the MHz and GHz bands is closely related to the surface resistance of the film. In general, the higher the surface resistance, the better the radio wave transmission. 5 When the resistance exceeds Ω / □, considerable permeability occurs in the VHF and UHF bands, and the surface resistance is 10 6 If the resistance is Ω / □ or more, radio wave transmission is almost equivalent to that of float glass across the entire VHF, UHF, and SHF bands (Non-Patent Document 1). Therefore, in order to ensure radio wave signal transmission, a surface resistance of at least 10 5 Ω / □ or more, preferably 10 6 A high resistance of Ω / □ or more is required (Non-Patent Document 1).

[0007] In Patent Document 3, similar to Patent Document 2, a thin film is formed by sputtering and has a sheet resistance of 10 5A composite tungsten oxide film (electrically insulating heat shielding film) with a resistivity of Ω / □ or more and an absorptivity of 35% or more at a wavelength of 1400 nm has been disclosed. With the spread of electric vehicles, heat shielding function is becoming essential to reduce air conditioning load and increase driving range, but at the same time, with the increase in comfort inside the car and the shift to automatic driving, the car windows are also required to be transparent to various sensor signals, so the composite tungsten oxide film (electrically insulating heat shielding film) disclosed in Patent Document 3 has attracted attention.

[0008] Incidentally, when using a composite tungsten oxide material such as cesium tungsten bronze as a target to obtain the performance of an electrically insulating and transparent heat ray shielding film by sputtering deposition, it is necessary to heat the substrate on which the film is to be deposited to 300° C. or higher during sputtering deposition, or to crystallize the sputtered film (composite tungsten oxide film) by annealing the substrate at a temperature of 300° C. or higher after sputtering deposition. For this reason, plate glass that can withstand the heat during sputtering deposition and annealing is used for the substrate on which the film is to be deposited.

[0009] However, when plate glass is used as the substrate, it is difficult to roll the plate glass and transport it continuously using the roll-to-roll method, which means that a composite tungsten oxide film (electrically insulating heat ray shielding film) cannot be efficiently produced. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] WO2005 / 037932 [Patent Document 2] JP 2006-117482 A [Patent Document 3] Patent No. 6540859 [Non-patent literature]

[0011] [Non-Patent Document 1] Hiroshi Ito, Keisuke Tanaka, Yuji Yamamoto, Yasuo Hashimoto, Hiroshi Kurihara, "Improvement of TV radio wave reflection characteristics of high-performance heat reflective glass," Technical Report of the Institute of Television Engineers of Japan, Vol. 15, pp. 15-21 (1991) Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention has been made in light of these problems, and an object of the present invention is to provide a method for efficiently producing a composite tungsten oxide film (electrically insulating heat ray shielding film), and a glass film with a near-infrared shielding film obtained by this production method.

[0013] More specifically, the present invention provides a method for producing a glass film with a near-infrared shielding film, in which a glass film is used instead of a plate glass as the above-mentioned substrate, and a composite tungsten oxide film (electrically insulating heat-ray shielding film) is heated and formed on the glass film, which is continuously transported by a roll-to-roll system, by means of sputtering or the like, or is annealed after non-heating film formation; and the present invention provides a glass film with a near-infrared shielding film obtained by this production method, as well as a near-infrared shielding film laminate formed by laminating the glass film with a near-infrared shielding film to a transparent substrate, such as a plate glass or a polycarbonate plate, and a production method thereof. [Means for solving the problem]

[0014] That is, the first invention according to the present invention is: A glass film with a thickness of 200 μm or less, a near-infrared shielding film formed on at least one surface of the glass film, the near-infrared shielding film being made of a composite tungsten oxide having a hexagonal crystal structure represented by a general formula MxWyOz (wherein 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); The near-infrared shielding film is characterized in that the maximum transmittance in the visible light region of 380 nm or more and 780 nm or less is 5% or more, and the reflectance at a wavelength of 1400 nm is 30% or more.

[0015] The second aspect of the present invention is In the glass film with a near-infrared shielding film according to the first aspect of the present invention, The near-infrared shielding film has a thickness of 10 nm or more and 500 nm or less, The third invention is In the glass film with a near-infrared shielding film according to the first or second invention, The surface resistance of the near infrared shielding film is 10 5 It is characterized by being Ω / □ or more, The fourth invention is In the glass film with a near-infrared shielding film according to the first aspect of the present invention, A bonding layer is formed on a surface of the near-infrared shielding film, The fifth invention is In the glass film with a near-infrared shielding film according to the fourth aspect of the present invention, The bonding layer is characterized in that it is made of an oxide selected from SiO2, Al2O3, ZrO2, TiO2, and HfO2.

[0016] Next, the sixth aspect of the present invention is In the near infrared shielding film laminate, A transparent substrate that transmits visible light; The glass film with a near-infrared shielding film according to the first or fourth invention is laminated on the transparent substrate, The seventh invention is In the near infrared shielding film laminate according to the sixth aspect of the present invention, The transparent substrate is characterized in being made of an inorganic material selected from plate glass or transparent ceramics, or an organic material selected from a resin film or a resin plate.

[0017] Furthermore, the eighth aspect of the present invention is In the method for producing a glass film with a near-infrared shielding film according to the first aspect of the present invention, A glass film unwinding process of unwinding a glass film having a thickness of 200 μm or less wound around an unwinding roll; a film formation step of forming a composite tungsten oxide film represented by a general formula MxWyOz (wherein 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) on at least one surface of the glass film unwound from a winding roll while transporting the glass film in a roll-to-roll manner by a film formation means; a heat treatment step of heat-treating the glass film on which the composite tungsten oxide is formed at a temperature equal to or lower than the strain point of the glass film to form a near-infrared shielding film made of a composite tungsten oxide having a hexagonal crystal structure; The present invention is characterized in that The ninth invention is In the method for producing a glass film with a near-infrared shielding film according to the eighth aspect of the present invention, In the heat treatment step, the glass film on which the composite tungsten oxide is formed is sequentially heat-treated using a plurality of heat treatment means, and the first heat treatment means is composed of an infrared heater that emits infrared rays with a wavelength of 1500 nm or more; The tenth invention is In the method for producing a glass film with a near-infrared shielding film according to the ninth aspect of the present invention, The first heat treatment means is a carbon heater or a SiC heater, The eleventh aspect of the present invention is In the method for producing the near-infrared shielding film laminate according to the sixth aspect of the present invention, The method includes a thermocompression bonding step of thermocompressing a glass film with a near-infrared shielding film according to the first or fourth invention and a transparent substrate made of an organic material according to the seventh invention, The twelfth invention is In the method for producing the near-infrared shielding film laminate according to the sixth aspect of the present invention, The method is characterized by comprising a surface activation step of activating at least one surface of the glass film with a near-infrared shielding film described in the first or fourth invention and a transparent substrate made of an inorganic material described in the seventh invention, and a bonding step of bonding the glass film with a near-infrared shielding film and the transparent substrate via the activated surface. Effect of the Invention

[0018] According to the glass film with a near-infrared shielding film and the method for producing the same of the present invention, Since a glass film having a thickness of 200 μm or less is applied to the substrate on which a near-infrared shielding film made of a composite tungsten oxide having a hexagonal crystal structure is formed, the glass film can be rolled up and continuously transported by a roll-to-roll method, which has the effect of efficiently producing a composite tungsten oxide film that functions as a heat ray shielding film. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a structural explanatory diagram of a near-infrared shielding film laminate according to a conventional example in which a plate glass 10 is used as a substrate and near-infrared shielding films 11 and 12 are formed on both sides of the substrate. [Diagram 2] FIG. 1 is a schematic diagram of a near-infrared shielding film-attached glass film 101A, 102A and a transparent substrate 100 according to the present embodiment in which glass films 101, 102 are applied as base materials and near-infrared shielding films 103, 104 are formed on one side thereof, and a near-infrared shielding film laminate 100A according to the present embodiment in which the near-infrared shielding film-attached glass films 101A, 102A are bonded to both sides of the transparent substrate 100. [Diagram 3]FIG. 13 is a schematic diagram of a near-infrared shielding film-attached glass film 201A, 202A according to the present embodiment in which glass films 201, 202 are applied as base materials and near-infrared shielding films 203, 204 and bonding layers 205, 206 are formed on one side thereof; a transparent substrate 200 in which bonding layers 207, 208 are formed on both sides thereof; and a near-infrared shielding film laminate 200A according to the present embodiment in which the near-infrared shielding film-attached glass films 201A, 202A are bonded to both sides of the transparent substrate 200 via the bonding layers 205, 206, 207, 208. [Figure 4] FIG. 1 is an explanatory diagram of the configuration of a roll-to-roll sputtering apparatus in which a glass film is continuously transported by a roll-to-roll method to produce a glass film with a near-infrared shielding film, and the produced glass film with a near-infrared shielding film is wound up into a roll. [Diagram 5] FIG. 1 is an explanatory diagram of the configuration of a roll-to-roll sputtering apparatus in which a glass film is continuously transported by a roll-to-roll method to produce a glass film with a near-infrared shielding film, and the produced glass film with a near-infrared shielding film is cut into sheets. [Figure 6] FIG. 1 is an explanatory diagram of a process for producing a near-infrared shielding film laminate 515 according to this embodiment by continuously bonding long glass films 501 and 502 with a near-infrared shielding film to both sides of a transparent substrate 500. [Figure 7] FIG. 6 is an explanatory diagram of a process for producing a near-infrared shielding film laminate 606 according to this embodiment by bonding cut glass films 601 and 602 with a near-infrared shielding film to both sides of a transparent substrate 600. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described in detail.

[0021] 1. Glass film with near infrared shielding coating The glass film with a near-infrared shielding film according to the present invention is A glass film with a thickness of 200 μm or less, a near-infrared shielding film formed on at least one surface of the glass film, the near-infrared shielding film being made of a composite tungsten oxide having a hexagonal crystal structure represented by a general formula MxWyOz (wherein 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); The near-infrared shielding film is characterized in that the maximum transmittance in the visible light region of 380 nm or more and 780 nm or less is 5% or more, and the reflectance at a wavelength of 1400 nm is 30% or more.

[0022] Hereinafter, the "(1) near-infrared shielding film," "(2) glass film," and "(3) bonding layer" constituting the glass film with near-infrared shielding film according to the present invention will be specifically described.

[0023] (1) Near infrared shielding film The near-infrared shielding film must be made of a composite tungsten oxide in order to have high transparency in the visible wavelength range and reflectivity in the near-infrared wavelength range.

[0024] The basic optical properties of the near-infrared shielding film made of a composite tungsten oxide film represented by the general formula MxWyOz (wherein 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) originate from the atomic arrangement of tungsten W and oxygen O.

[0025] Specifically, when the composite tungsten oxide constituting the near-infrared shielding film has a hexagonal crystal structure, the transmission of the near-infrared shielding film in the visible light region is improved, and the shielding of the near-infrared region with a wavelength exceeding 780 nm (wavelength 780 nm to 2000 nm according to "Infrared Heating Terminology" compiled by the Japan Electric Heat Association, see JIS Z 8117 2002) is improved. When the composite tungsten oxide has a uniform hexagonal crystal structure, the amount of element M added is preferably 0.2 to 0.5 relative to 1 tungsten, and more preferably 0.33. When the composite tungsten oxide has M 0.33 It is believed that by forming WO3, the element M is placed in all of the hexagonal gaps. From the viewpoint of forming a hexagonal crystal structure, the 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 more preferably selected from Cs.

[0026] The near-infrared shielding film has a maximum transmittance of 5% or more in the visible light region of 380 nm to 780 nm, and a reflectance of 30% or more at a wavelength of 1400 nm. The near-infrared shielding film made of the composite tungsten oxide according to this embodiment has a reflectance peak in the wavelength range of 1400 nm to 2700 nm, and if the reflectance at a wavelength of 1400 nm is 30% or more, the incidence of near-infrared rays that contribute to an increase in room temperature among sunlight entering through a window can be reduced. The near-infrared shielding film made of the composite tungsten oxide according to this embodiment has a transmittance peak in the visible light region of 400 nm to 700 nm, and 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 a window, it is difficult to look inside the room from outside, but it is possible to see the outside from inside the room.

[0027] Incidentally, in order for a near-infrared shielding film made of composite tungsten oxide to exhibit the above-mentioned optical properties (i.e., a maximum transmittance of 5% or more in the visible light region of wavelengths 380 nm to 780 nm and a reflectance of 30% or more at a wavelength of 1400 nm), the crystallinity of the composite tungsten oxide is important. In order for the composite tungsten oxide to have crystallinity, it is necessary to form the film at a temperature of 400° C. or more, or to heat-treat (anneal) a non-heat-treated film formed at a temperature below 400° C. at a temperature of 400° C. or more. Of course, film formation at a temperature of 400° C. or more and heat treatment at a temperature of 400° C. or more may be used in combination.

[0028] Furthermore, in the present invention, reflection (reflectance at a wavelength of 1400 nm or more) is used in the near-infrared shielding film. When transmitting light in the visible range and shielding light in the near-infrared range, the near-infrared shielding film can shield light in the near-infrared range by absorbing or reflecting light in the near-infrared range. However, when light in the near-infrared range is absorbed, the absorbed light in the near-infrared range is converted into heat, which heats the near-infrared shielding film and the glass film that is the substrate on which the film is formed, and the glass film with the near-infrared shielding film expands thermally. In the near-infrared shielding film laminate described below, if the thermal expansion coefficients of the glass film with the near-infrared shielding film and the transparent substrate that transmits visible light to be laminated are not close to each other, the glass film with the near-infrared shielding film that expands due to absorption of near-infrared rays may be damaged. On the other hand, if the near-infrared shielding film reflects near-infrared rays, the glass film with the near-infrared shielding film is less likely to be heated by near-infrared rays and expands less due to heat, so it is not damaged by irradiation of near-infrared rays.

[0029] The surface resistance of the near-infrared shielding film according to this embodiment is 10 5 It is preferable that the resistance is Ω / □ or more, and 10 6 The thickness of the near infrared shielding film is preferably 10 nm or more and 500 nm or less, and more preferably 10 nm or more and 300 nm or less.

[0030] In addition, when forming a near-infrared shielding film laminate described later, in the case where a resin film is used as a transparent substrate that transmits visible light, the thickness of the near-infrared shielding film can be set to 10 nm or more and 250 nm or less. By reducing the thickness of the near-infrared shielding film, the crystallinity of the near-infrared shielding film can be improved, and the reflection characteristics in the near-infrared region can be further improved.

[0031] (2) Glass Film The thickness of the glass film used in the near-infrared shielding glass film according to the present invention is preferably 10 μm or more and 200 μm or less, more preferably 10 μm or more and 100 μm or less. If the thickness of the glass film is less than 10 μm, it becomes difficult to handle, and if the thickness exceeds 200 μm, it may be difficult to wind it up.

[0032] The material of the glass film is not particularly limited, and for example, silicate glass, silica glass, borosilicate glass, soda-lime glass, aluminosilicate glass, chemically strengthened glass, non-alkali glass, etc. can be used.

[0033] In the manufacturing method of the glass film with a near-infrared shielding film according to the present invention described later, a heat treatment step is performed after a composite tungsten oxide film formation step. The heat treatment temperature in the heat treatment step is desirably equal to or lower than the strain point, taking into consideration deformation of the glass film, etc. The strain point of the glass film is desirably 550° C. or higher. In order to enable a higher treatment temperature in the heat treatment step, the glass film on which the composite tungsten oxide film is formed can be made of the above-mentioned silicate glass, silica glass, borosilicate glass, soda-lime glass, aluminosilicate glass, chemically strengthened glass, or non-alkali glass.

[0034] The glass film can be obtained by forming it by a conventionally known float method, roll-out method, slot downdraw method, overflow downdraw method, redraw method, etc. Among them, it is preferable that it is formed by the overflow downdraw method. The glass film formed by the overflow downdraw method can be formed to a thickness of 10 μm or more and 200 μm or less, and can maintain the smoothness of the surface.

[0035] In addition, when a plate glass is used as the transparent substrate of the near-infrared shielding film laminate described later, the difference between the thermal expansion coefficients of the glass film and the plate glass must be within 10% of the smaller of the two thermal expansion coefficients. In the near-infrared shielding film laminate, if the difference between the thermal expansion coefficients of the glass film and the plate glass exceeds 10%, the glass film may be damaged. The near-infrared shielding film of the glass film with near-infrared shielding film according to the present invention has a reflectance of 30% or more at a wavelength of 1400 nm, and is characterized by shielding near-infrared rays by reflection. As a result, the glass film expands only slightly even when irradiated with near-infrared rays. On the other hand, when shielding near-infrared rays by absorbing near-infrared rays, the glass film will be damaged even if the difference between the thermal expansion coefficients of the glass film and the plate glass is controlled to within 5%.

[0036] (3) bonding layer A bonding layer can be provided on the surface of the near-infrared shielding film of the glass film with a near-infrared shielding film according to the present invention. When the glass film with a near-infrared shielding film and a transparent substrate that transmits visible light are laminated together to form a near-infrared shielding film laminate, the bonding layer is disposed between the near-infrared shielding film and the transparent substrate to bond them together. When the bonding layer is subjected to room temperature compression bonding after cleaning the surface with an ion beam or the like, it is possible to bond the glass film with a near-infrared shielding film to the transparent substrate that transmits visible light.

[0037] The bonding layer is preferably made of an oxide selected from SiO2, Al2O3, TiO2, ZrO2, and HfO2. The surface of the bonding layer made of these oxides is cleaned and activated by ion beam, plasma irradiation, atmospheric pressure plasma irradiation, and corona discharge, enabling room temperature bonding.

[0038] 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. If the thickness of the bonding layer is less than 1 nm, the bonding effect cannot be expected. On the other hand, if the thickness of the bonding layer exceeds 10 nm, it may affect the heat treatment of the composite tungsten oxide described above and inhibit the crystallization of the composite tungsten oxide.

[0039] The bonding layer can be formed by sputtering. A sputtering target made of metal or metal oxide can be used to form the bonding layer. When an Al2O3 film is to be formed, a metal Al target or a metal oxide Al2O3 target can be used; when a TiO2 film is to be formed, a metal Ti target or a metal oxide TiO2 target can be used; when a ZrO2 film is to be formed, a metal Zr target or a metal oxide ZrO2 target can be used; when a HfO2 film is to be formed, a metal Hf target or a metal oxide HfO2 target can be used. Even when using a metal target, an insulating metal oxide can be obtained by reactive sputtering in which oxygen is introduced.

[0040] 2. Method for manufacturing glass film with near-infrared shielding film (1) Film forming process The near-infrared shielding film of the glass film with a near-infrared shielding film according to the present invention shields near-infrared rays by utilizing reflection of near-infrared rays (reflectance at a wavelength of 1400 nm is 30% or more).

[0041] To obtain a near-infrared shielding film made of a composite tungsten oxide that reflects near-infrared rays, it is preferable to form the film on a glass film substrate by magnetron sputtering, ion beam sputtering, pulsed laser deposition, or electron beam evaporation. In these film formation methods, the composite tungsten oxide is formed as a continuous film.

[0042] If possible, it is also beneficial to heat the film to a temperature of 400° C. or higher during film formation in order to improve the crystallinity of the composite tungsten oxide.

[0043] (1-1) Film formation method using sputtering The target used when forming the composite tungsten oxide (or the unheat-treated film when crystallization by heat treatment has not been achieved) is not particularly limited, but for example, a cesium composite tungsten oxide sintered body target can be used.

[0044] The composition of the target used when forming the composite tungsten oxide film (unheat-treated film) is preferably such that, for example, Cs / W, which is the ratio of the amount of substance between cesium (Cs) and tungsten (W), is 0.2 or more and 0.7 or less. This is because the composition of the target used during film formation is reflected in Cs / W, which is the ratio of the amount of substance between cesium (Cs) and tungsten (W) contained in the formed film.

[0045] The crystal structure of the target is not particularly limited since it does not directly affect the crystal structure of the film to be formed. The target preferably has a relative density of 70% or more and a resistivity of 1 Ω·cm or less.

[0046] The method for producing the target is not particularly limited, but for example, the target can be produced by hot-press sintering the cesium-tungsten composite oxide powder in a vacuum or inert atmosphere. The sintered body produced in this way has a strength that can withstand the brazing temperature during machining and bonding in the target production, and has electrical conductivity that allows direct current sputtering.

[0047] The composite tungsten oxide (unheat-treated film) can be formed by the sputtering method described above. When the sputtering method is used as the film formation method, the direct current sputtering film formation method in which a direct current voltage or a pulse voltage is applied to the target is preferred. This is because the film formation speed is high and the productivity is excellent.

[0048] When forming the composite tungsten oxide film (unheat-treated film), the sputtering gas is not particularly limited, but for example, argon gas or a mixed gas of argon and oxygen can be used.

[0049] Whether argon gas or a mixed gas is used in the film formation process can be selected depending on the conditions of the subsequent "heat treatment process."

[0050] When a mixed gas is used as the sputtering gas in the film formation process, the oxygen concentration is not particularly limited. However, if the oxygen concentration in the mixed gas is high, the film formation rate decreases and the productivity decreases. Therefore, the oxygen concentration in the mixed gas is preferably less than 20 vol%, and more preferably 5 vol% or more and 10 vol% or less.

[0051] When argon gas is used as the sputtering gas in the film formation process, it is preferable that the purity of the argon gas is 99 vol % or more and the oxygen concentration is less than 1 vol %.

[0052] The specific conditions for the film formation process are as follows: the pre-sputtering of the target, the ultimate vacuum before the introduction of reactive gas is 1×10 -4 Pa, and more preferably 1×10 -5 Less than Pa.

[0053] (1-2) Film formation method using pulsed laser deposition In the Pulsed Laser Deposition (PLD) method, a raw material target placed inside a vacuum chamber is irradiated with laser light from outside the vacuum chamber. This process causes atoms or molecules to be peeled off (ablation) from the target, forming a thin film on the substrate facing the target. The Pulsed Laser Deposition method is effective for target materials that have a high absorption of the irradiated laser.

[0054] In addition, the pulsed laser deposition method can be used with a tablet target with a diameter of about 20 mm, so the pulsed laser deposition method can be preferably used.

[0055] In addition, the pulsed laser deposition method does not require plasma gas such as argon, which is required for sputtering. Furthermore, since it is said that the target composition can be transferred to the film on the substrate, a film of the desired composition can be easily formed.

[0056] In pulsed laser deposition, the target does not need to be cooled because the duty ratio of the laser irradiated to the target is small, and therefore the backing plate that is provided with the target used in sputtering is not required.

[0057] Oxygen, nitrogen, carbon, and the like contained in the target may be exhausted during film formation, and can be adjusted by the reactive gas introduced during film formation.

[0058] The specific conditions for the film formation process are: the ultimate vacuum before the introduction of reactive gas is 1×10 -4 Pa, and more preferably 1×10 -5 Less than Pa.

[0059] (1-3) Film formation method using electron beam evaporation The electron beam deposition method is 1×10 -2This is a deposition method in which a target to be deposited is irradiated with an electron beam under reduced pressure of less than Pa, heating and evaporating the target to form a film on a substrate. The same targets as those used in the sputtering method can be used.

[0060] (2) Heat Treatment Process A composite tungsten oxide (unheat-treated film) 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) that has been formed on the surface of a glass film by a film-forming method such as sputtering is heat-treated to form a hexagonal crystal structure. The heat treatment is performed in an atmosphere selected according to the gas used during film formation by sputtering or the like, so that the oxygen concentration of the near-infrared shielding film made of the composite tungsten oxide after the heat treatment falls within an appropriate range.

[0061] When sputtering is applied to the film forming means, if a mixed gas of argon and oxygen is used for film formation, the heat treatment of the composite tungsten oxide (unheat-treated film) in the heat treatment step is performed in an inert or reducing atmosphere at a temperature of 400°C to 900°C, preferably 400°C to 700°C, more preferably 400°C to 650°C. As the inert or reducing atmosphere, nitrogen gas, argon gas, a mixed gas of hydrogen and nitrogen, a mixed gas of hydrogen and argon, etc. can be used. When the film is formed in an atmosphere containing oxygen, if the heat treatment step is performed in an oxidizing atmosphere such as air or oxygen, the oxidation of the film may proceed excessively, the oxygen vacancies may decrease, the crystal structure may change, and the heat ray shielding performance may decrease. When the heat treatment temperature is less than 400°C, the composite tungsten oxide (unheat-treated film) remains amorphous and does not crystallize, or even if it crystallizes, the hexagonal diffraction peak in X-ray diffraction is extremely weak, and the heat ray shielding performance may be low. In addition, the hexagonal crystal structure maintains its structure even at high temperatures of 900°C or higher in an inert or reducing atmosphere, but if the heat treatment temperature is higher than 1000°C, the film will change due to a reaction between the composite tungsten oxide (unheat-treated film) and the glass film, and the film will peel off and disappear. Taking these factors into consideration, it is necessary to appropriately adjust the heat treatment conditions so that the reflectance at a wavelength of 1400 nm is 30% or higher.

[0062] In addition, the heat treatment temperature must be determined taking into consideration the strain point and glass transition point of the glass film. In particular, heat treatment at a temperature higher than the glass transition point may cause deformation of the glass film. Here, the "strain point" refers to the temperature at which the viscosity of heated glass becomes approximately 10 13 The "strain point" is the temperature that corresponds to the viscosity in dPa·s, and is a temperature lower than the glass transition point. For this reason, it is desirable to carry out heat treatment at a temperature below the "strain point."

[0063] 3. Near infrared shielding film laminate The near-infrared shielding film laminate according to the present invention is composed of a transparent substrate that transmits visible light, and the above-mentioned near-infrared shielding film-coated glass film laminated on the transparent substrate.

[0064] (1) Conventional near-infrared shielding film laminate The near-infrared shielding film laminate shown in Fig. 1 can be produced by using a plate glass 10 as a substrate and forming near-infrared shielding films 11 and 12 made of composite tungsten oxide on both sides of the plate glass 10 by a film forming means such as sputtering. However, when the plate glass 10 is used as the substrate, it is difficult to roll the plate glass 10 and continuously transport it by a roll-to-roll method as described above, and therefore it is not possible to efficiently produce the near-infrared shielding film laminate shown in Fig. 1.

[0065] Furthermore, since the near-infrared shielding film made of composite tungsten oxide needs to be heat-treated at a temperature of 400°C or higher to crystallize the composite tungsten oxide (unheat-treated film), a resin film cannot be used as the substrate.

[0066] (2) Near infrared shielding film laminate according to the present invention In the present invention, a glass film that can be heat-treated at 400°C or higher is used as a substrate instead of a plate glass, and the glass film is continuously transported by a roll-to-roll system. At the same time, a composite tungsten oxide film is thermally formed on the glass film by means of sputtering or the like, or a non-thermal film formation is followed by annealing treatment to efficiently obtain the above-mentioned glass film with a near-infrared shielding film.

[0067] As described above, the near-infrared shielding film laminate according to 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.

[0068] Here, examples of materials that can be used for the transparent substrate that transmits visible light include inorganic materials selected from plate glass or transparent ceramics, and organic materials selected from transparent resin films or resin plates such as polyethylene terephthalate (PET), polycarbonate, acrylic resin, and polystyrene resin.

[0069] In the near-infrared shielding film laminate according to this embodiment, it is preferable that at least one of the bonding surfaces of the near-infrared shielding film-attached glass film and the transparent substrate that transmits visible light is surface-activated, and then the glass film and the transparent substrate are bonded in close contact with each other.

[0070] In order to activate the bonding surface in this way, at least one of the surfaces of the glass film with a near-infrared shielding film and the transparent substrate may be cleaned by plasma irradiation, ion beam irradiation, or the like. It is also useful to introduce hydroxyl groups to the bonding surface by water adsorbed to the bonding surface by plasma irradiation. It is also useful to provide the above-mentioned bonding layer on the surface of the near-infrared shielding film of the glass film with a near-infrared shielding film.

[0071] Examples of a method for bonding the near-infrared shielding film-attached glass film to the transparent substrate include a method of bonding by applying pressure, or a method of applying heat in addition to pressure to bond the glass film to the transparent substrate.

[0072] However, when a method of bonding the glass film with a near-infrared shielding film to the transparent substrate via a commonly known adhesive or double-sided tape for optical applications with high transparency is adopted, the reliability of the bonding by the adhesive or double-sided tape is low, and there is a risk that the glass film with a near-infrared shielding film will peel off from the transparent substrate after long-term use. For this reason, the above-mentioned adhesion method is adopted in the present invention.

[0073] (2-1) Near infrared shielding film laminate having no adhesive layer FIG. 2 is a structural explanatory diagram of glass films 101A, 102A and a transparent substrate 100 according to the present embodiment in which glass films 101, 102 are applied as base materials and near-infrared shielding films 103, 104 are formed on one side thereof, and a near-infrared shielding film laminate 100A according to the present embodiment in which the glass films 101A, 102A and the near-infrared shielding film are bonded to both sides of the transparent substrate 100.

[0074] As shown in FIG. 2, the near-infrared shielding film-attached glass films 101A and 102A according to this embodiment, each having near-infrared shielding films 103 and 104 formed on one side thereof, can be bonded to a transparent substrate 100 by the adhesion method described above to obtain the near-infrared shielding film laminate 100A according to this embodiment.

[0075] When polycarbonate is used for the transparent substrate 100, bonding is possible if the Vicat softening temperature is 149° C. or higher. Even if a temperature of 149° C. or higher is applied, it is preferable to expose the bonding surface as an activated surface by argon ion beam or the like. The Vicat softening temperature is the temperature at which a thermoplastic plastic starts to soften.

[0076] (2-2) Near infrared shielding film laminate having an adhesive layer FIG. 3 is a configuration explanatory diagram of glass films 201A, 202A with near-infrared shielding film according to the present embodiment in which glass films 201, 202 are applied as base materials and near-infrared shielding films 203, 204 and bonding layers 205, 206 are formed on one side thereof, a transparent substrate 200 in which bonding layers 207, 208 are formed on both sides thereof, and a near-infrared shielding film laminate 200A according to the present embodiment in which the glass films 201A, 202A with near-infrared shielding film are bonded to both sides of the transparent substrate 200 via the bonding layers 205, 206, 207, 208.

[0077] As shown in FIG. 3, the near-infrared shielding film-attached glass films 201A and 202A according to this embodiment, in which near-infrared shielding films 203 and 204 and bonding layers 205 and 206 are formed on one side, can be bonded to a transparent substrate 200, in which bonding layers 207 and 208 are formed on both sides, by the above-mentioned adhesion method to obtain the near-infrared shielding film laminate 200A according to this embodiment.

[0078] It is desirable to expose the active surface of each bonding surface by argon ion beam or the like, and if the bonding layers 205, 206, 207, 208 having a thickness of about 1 to 10 nm are made of insulating materials such as Al2O3, TiO2, ZrO2, HfO2, etc., pressure room temperature bonding is possible. However, slight heating and pressure are preferable to obtain stable bonding strength. Since the glass films 201A and 202A with near infrared shielding film are thin and prone to air bubbles, it is preferable to bond them to the transparent substrate 200 made of glass or polycarbonate in a vacuum.

[0079] In addition, in the near-infrared shielding film laminate 200A according to this embodiment shown in FIG. 3, bonding layers 205, 206, 207, and 208 having a thickness of about 1 to 10 nm are provided on the near-infrared shielding film-attached glass films 201A and 202A and the transparent substrate (made of, for example, float glass or polycarbonate) 200, respectively. However, similar to the near-infrared shielding film laminate 100A shown in FIG. 2, pressure and heat bonding near the softening point temperature is possible without the bonding layers 205, 206, 207, and 208.

[0080] 4. Method for manufacturing glass film with near-infrared shielding film using roll-to-roll sputtering equipment (1) Method for forming near-infrared shielding film Next, a method for forming a near-infrared shielding film made of a composite tungsten oxide that reflects near-infrared rays (having a reflectance of 30% or more at a wavelength of 1400 nm) will be specifically described below.

[0081] The substrate for forming the near-infrared shielding film made of composite tungsten oxide is a flexible long glass film instead of a conventional plate glass, and is continuously transported by a roll-to-roll method. In addition, the method for forming the composite tungsten oxide constituting the near-infrared shielding film is preferably sputtering film formation in consideration of mass productivity, and the power source can be a direct current power source, a medium frequency power source, a high frequency power source, a pulse power source, a large current pulse power source, or the like.

[0082] A composite tungsten oxide represented by the general formula MxWyOz (wherein 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) exhibits the ability to reflect near-infrared light when formed into a film under heating conditions of 400°C or higher or when subjected to heat treatment after film formation, forming a hexagonal crystal structure.

[0083] For this reason, the roll-to-roll sputtering apparatus used for manufacturing a glass film with a near-infrared shielding film is equipped with at least one of a "film formation process zone" in which a composite tungsten oxide film is formed under heating at a temperature of 400°C or higher, or an "annealing zone" in which the formed film (non-heat-treated film) is subjected to heat treatment at a temperature of 400°C or higher, and may be equipped with both the "film formation process zone" in which a composite tungsten oxide film is formed under heating at a temperature of 400°C or higher, and the "annealing zone."

[0084] In addition, a roll-to-roll sputtering apparatus used for manufacturing a glass film with a near-infrared shielding film needs a "heater zone" for drying moisture on the surface of the glass film before film formation, and the above-mentioned "film formation process zone" for forming a film of a composite tungsten oxide.

[0085] Furthermore, if the temperature in the "film formation process zone" is less than 400°C, the above-mentioned "annealing zone" is required to heat treat (heat treatment process) the composite tungsten oxide film (non-heat treated film).

[0086] Hereinafter, a process for forming a composite tungsten oxide film represented by the general formula MxWyOz on a long glass film using the roll-to-roll sputtering apparatus shown in Figs. 4 and 5 will be described.

[0087] Note that exhaust pumps and reaction gas introduction mechanisms are not shown in Figures 4 and 5. To exhaust moisture desorbed from the inner walls of the chamber, it is effective to install cryocoils or cryopanels that condense moisture at low temperatures.

[0088] (2) A roll-to-roll sputtering device that winds up glass film with near-infrared shielding coating into a roll The roll-to-roll sputtering apparatus, in which the manufactured glass film with a near-infrared shielding film is wound into a roll, is equipped with an unwinding zone 302, a transport zone 303, a heater zone 304, a transport zone 305, a surface treatment zone 306, a film formation process zone 307, an annealing zone 308, a transport / cooling zone 309, and a winding zone 310, as shown in FIG. 4.

[0089] In addition, the pressure can be adjusted by providing opposing slit rolls between each zone and introducing argon gas or the like into each zone. The unwinding zone 302 corresponds to the "glass film unwinding step" in the manufacturing method of a glass film with a near-infrared shielding film according to the present invention.

[0090] Here, the symbols written on each roll will be explained as follows: "F" is a free roll that does not have a driving force and is rotated by the transport of the glass film, "T" is a tension roll equipped with a tension sensor on the axis of the free roll or inside, and "M" is a motor-driven roll whose rotation is controlled by a motor. These roll arrangements are examples of the minimum necessary roll arrangements, and are not limited to these roll arrangements. A carrier film (interleaving film) 301 is often attached to the glass film 300 to make it easier to wind it up.

[0091] First, a glass film 300A with a carrier film is set on a glass film unwinding roll 311 with a carrier film in an unwinding zone 302, and the carrier film (interleaving film) 301 is taken up on a carrier film take-up roll 312 via a free roll 314. In order to pass the glass film 300 through a roll-to-roll sputtering device, a method is often used in which the glass film 300 is connected to a passing film that has been passed through a transport route in advance and pulled.

[0092] After setting the glass film 300A with the carrier film, start evacuation. Generally, after rough evacuation with a dry pump, evacuation to high vacuum is performed with multiple turbo molecular pumps. It is effective to use a cryopipe to evacuate moisture.

[0093] The glass film 300A with a carrier film passes through a touch roll 313 for preventing the glass film 300A unwound from a glass film unwinding roll 311 with a carrier film from flapping, and at the end of a free roll 314, the carrier film (interleaving film) 301 is peeled off from the glass film 300A with a carrier film, and then the carrier film 301 is taken up by a carrier film take-up roll 312 as described above. The glass film 300 from which the carrier film (interleaving film) 301 has been peeled off enters a transport zone 303 via a tension roll 315 that measures the unwinding tension. The unwinding tension is detected by the tension roll 315, and the unwinding tension is adjusted by the balance between the motor-driven roll 316 and the glass film unwinding roll 311 with a carrier film.

[0094] The glass film 300 carried into the transport zone 303 is carried into the heater zone 304 via a motor-driven roll 316, free rolls 317 and 318, and a tension roll 319. Here, the transport tension of the heater zone 304 is adjusted by a motor-driven roll 328 based on detection of the transport tension by the tension roll 319.

[0095] The glass film 300 carried into the heater zone 304 passes between heaters 320, 321, 322, and 323 by free rolls 324, 325, 326, and 327, and enters the transport zone 305. The heater must be capable of irradiating a wavelength that is absorbed by the glass film, and for example, a carbon heater, a mid-infrared heater, a SiC heater, or the like can be used. The heater temperature can be maintained at a set temperature by PID control of the current value using a thermometer such as a thermocouple.

[0096] The glass film 300 carried into the transport zone 305 is carried into the surface treatment zone 306 via a motor-driven roll 328, free rolls 329 and 330, and a tension roll 331. Here, the transport tension in the surface treatment zone 306 is adjusted by a motor-driven roll 335 based on detection of the transport tension by the tension roll 331.

[0097] The glass film 300 carried into the surface treatment zone 306 passes in front of surface treatment devices 332 and 333 via a free roll 334 and a motor-driven roll 335 and then enters the film formation zone 307. An ion beam, plasma, or the like can be used for the surface treatment device.

[0098] The glass film 300 carried into the film formation process zone 307 enters the annealing zone 308 via a tension roll 345, a free roll 346, a process roll 336, a free roll 347, and a tension roll 348. The tension at which the glass film 300 enters the process roll 336 is detected by the tension roll 345 and adjusted by the rotation speed balance between the motor-driven roll 335 and the process roll 336, while the tension at which the glass film 300 leaves the process roll 336 is detected by the tension roll 348 and adjusted by the rotation speed balance between the motor-driven roll 353 and the process roll 336.

[0099] Sputtering cathodes 337, 338, 339, 340, 341, 342, 343, and 344 are arranged around the process roll 336. The sputtering cathodes may be flat or cylindrical. Sputtering gas (argon) and gas (oxygen) required for reactive sputtering are introduced to each sputtering cathode via a flow meter. The process roll 336 and the sputtering cathodes constitute the film formation process zone 307.

[0100] The glass film 300 carried into the annealing zone 308 passes between heaters 349, 350, 351, and 352 by a motor-driven roll 353 and free rolls 354, 355, and 356, and enters the conveying and cooling zone 309. The heaters 349, 350, 351, and 352 constitute the annealing zone. At least the heater 349 needs to irradiate wavelengths that are absorbed by the glass film, and for example, a carbon heater, a mid-infrared heater, a SiC heater, or the like, which is an infrared heater that emits infrared rays with a wavelength of 1500 nm or more, can be adopted. When the crystallization of the composite tungsten oxide starts, the composite tungsten oxide starts absorbing near-infrared rays, and the crystallization is promoted to become a reflective film, and in the process of absorbing near-infrared rays, the composite tungsten oxide can become a near-infrared heater with high energy density. Specifically, halogen heaters can be arranged for the heaters 351 and 352. The temperature of the heater can be maintained at a set temperature by PID control of the current value using a thermometer such as a thermocouple. Moreover, gases necessary for annealing may be introduced.

[0101] When the annealing treatment is performed consistently after the composite tungsten oxide film is formed using a roll-to-roll sputtering apparatus, the conveying speed of the glass film is related to the time spent in the annealing zone 308, and therefore needs to be set to a time sufficient for the composite tungsten oxide to crystallize. Of course, after the composite tungsten oxide film is formed on the glass film using the roll-to-roll sputtering apparatus, a separate annealing treatment may be performed using a separate vacuum annealing apparatus or a nitrogen / argon / reducing atmosphere annealing apparatus.

[0102] Here, the transport tension is detected by a tension roll 357 and the transport tension in the transport cooling zone 309 is adjusted by a motor-driven cooling roll 360 .

[0103] The glass film 300 conveyed into the transport cooling zone 309 passes through a tension roll 357, free rolls 358 and 359, and a motor-driven cooling roll 360, and then enters a winding zone 310. The glass film after deposition and annealing is cooled by the motor-driven cooling roll 360 in order to prevent tight winding when cooled after winding, and the number of motor-driven cooling rolls 360 may be increased as necessary to gradually cool the glass film.

[0104] The glass film 300 carried into the winding zone 310 passes through a tension roll 363, onto which a carrier film 364 unwound from a carrier film unwinding roll 362 is attached on a free roll 365, passes through a touch roll 366 that prevents the film from flapping when being wound, and is then wound around a winding roll 361. The winding tension is detected by the tension roll 363, and the winding tension is adjusted by the balance between the motor-driven cooling roll 360 and the winding roll 361.

[0105] (3) Roll-to-roll sputtering equipment in which glass film with near-infrared shielding coating is cut into sheets The roll-to-roll sputtering apparatus in which the manufactured glass film with near-infrared shielding film is cut into sheets includes an unwinding zone 402, a transport zone 403, a heater zone 404, a transport zone 405, a surface treatment zone 406, a film formation process zone 407, an annealing zone 408, a transport and cooling zone 409, a tension adjustment zone 410, a differential exhaust zone 464, and a cutting zone 467, as shown in FIG. 5.

[0106] In addition, the pressure can be adjusted by providing opposing slit rolls between each zone and introducing argon gas or the like into each zone. Regarding the symbols written on each roll, "F" is a free roll that does not have a driving force and is rotated by the transport of the glass film, "T" is a tension roll equipped with a tension sensor on the axis of the free roll or inside, and "M" is a motor-driven roll whose rotation is controlled by a motor. These roll arrangements are examples of the minimum necessary, and are not limited to these roll arrangements. A carrier film (interleaving film) 401 is often attached to the glass film 400 to make it easier to wind it up.

[0107] First, a glass film 400A with a carrier film is set on a glass film unwinding roll 411 with a carrier film in an unwinding zone 402, and the carrier film (interleaving film) 401 is taken up on a carrier film take-up roll 412 via a free roll 414. In order to pass the glass film 400 through a roll-to-roll sputtering device, a method is often used in which the glass film 400 is connected to a passing film that has been passed through a transport route in advance and pulled.

[0108] After setting the glass film 400A with the carrier film, start evacuation. Generally, after rough evacuation with a dry pump, evacuation to high vacuum is performed with multiple turbo molecular pumps. It is effective to use a cryopipe to evacuate moisture.

[0109] The glass film 400A with a carrier film passes through a touch roll 413 for preventing the glass film 400A unwound from a glass film unwinding roll 411 with a carrier film from flapping, and at the end of a free roll 414, the carrier film (interleaving film) 401 is peeled off from the glass film 400A with a carrier film, and then the carrier film 401 is taken up by a carrier film take-up roll 412 as described above. The glass film 400 from which the carrier film (interleaving film) 401 has been peeled off enters a transport zone 403 via a tension roll 415 that measures the unwinding tension. The unwinding tension is detected by the tension roll 415, and the unwinding tension is adjusted by the balance between the motor-driven roll 416 and the glass film unwinding roll 411 with a carrier film.

[0110] The glass film 400 carried into the transport zone 403 is carried into the heater zone 404 via a motor-driven roll 416, free rolls 417 and 418, and a tension roll 419. Here, the transport tension of the heater zone 404 is adjusted by a motor-driven roll 428 based on detection of the transport tension by the tension roll 419.

[0111] The glass film 400 carried into the heater zone 404 passes between heaters 420, 421, 422, and 423 by free rolls 424, 425, 426, and 427, and enters the transport zone 405. The heater must be capable of irradiating a wavelength that is absorbed by the glass film, and for example, a carbon heater, a mid-infrared heater, a SiC heater, or the like can be used. The heater temperature can be maintained at a set temperature by PID control of the current value using a thermometer such as a thermocouple.

[0112] The glass film 400 carried into the transport zone 405 is carried into the surface treatment zone 406 via a motor-driven roll 428, free rolls 429 and 430, and a tension roll 431. Here, the transport tension in the surface treatment zone 406 is adjusted by a motor-driven roll 435 based on detection of the transport tension by the tension roll 431.

[0113] The glass film 400 carried into the surface treatment zone 406 passes in front of surface treatment devices 432 and 433 via a free roll 434 and a motor-driven roll 435 and then enters the film formation zone 407. An ion beam, plasma, or the like can be used for the surface treatment device.

[0114] The glass film 400 carried into the film formation process zone 407 enters the annealing zone 408 via a tension roll 445, a free roll 446, a process roll 436, a free roll 447, and a tension roll 448. The tension at which the glass film 400 enters the process roll 436 is detected by the tension roll 445 and adjusted by the rotation speed balance between the motor-driven roll 435 and the process roll 436, while the tension at which the glass film 400 leaves the process roll 436 is detected by the tension roll 448 and adjusted by the rotation speed balance between the motor-driven roll 453 and the process roll 436.

[0115] Sputtering cathodes 437, 438, 439, 440, 441, 442, 443, and 444 are arranged around the process roll 436. The sputtering cathodes may be flat or cylindrical. Sputtering gas (argon) and gas (oxygen) required for reactive sputtering are introduced to each sputtering cathode via a flow meter. The process roll 436 and the sputtering cathodes constitute the film formation process zone 407.

[0116] The glass film 400 carried into the annealing zone 408 passes between heaters 449, 450, 451, and 452 by a motor-driven roll 453 and free rolls 454, 455, and 456, and enters the conveying and cooling zone 409. The heaters 449, 450, 451, and 452 constitute the annealing zone. At least the heater 449 needs to irradiate wavelengths that are absorbed by the glass film, and for example, a carbon heater, a mid-infrared heater, a SiC heater, or the like, which is an infrared heater that emits infrared rays with a wavelength of 1500 nm or more, can be adopted. When the crystallization of the composite tungsten oxide starts, the composite tungsten oxide starts absorbing near-infrared rays, and the crystallization is promoted to become a reflective film, and in the process of absorbing near-infrared rays, the composite tungsten oxide can become a near-infrared heater with high energy density. Specifically, halogen heaters can be arranged for the heaters 451 and 452. The temperature of the heater can be maintained at a set temperature by PID control of the current value using a thermometer such as a thermocouple. Moreover, gases necessary for annealing may be introduced.

[0117] When the annealing treatment is performed consistently after the composite tungsten oxide film is formed using a roll-to-roll sputtering apparatus, the conveying speed of the glass film is related to the time spent in the annealing zone 408, and therefore needs to be set to a time sufficient for the composite tungsten oxide to crystallize. Of course, after the composite tungsten oxide film is formed on the glass film using the roll-to-roll sputtering apparatus, a separate annealing treatment may be performed using a separate vacuum annealing apparatus or a nitrogen / argon / reducing atmosphere annealing apparatus.

[0118] Here, the transport tension is detected by a tension roll 457 and the transport tension in the transport cooling zone 409 is adjusted by a motor-driven cooling roll 460 .

[0119] The glass film 400 conveyed into the conveying and cooling zone 409 enters the tension adjustment zone 410 via a tension roll 457, free rolls 458 and 459, and a motor-driven cooling roll 460. The glass film after deposition and annealing is cooled by the motor-driven cooling roll 460 in order to prevent tight winding when cooled after winding, and the number of motor-driven cooling rolls 460 may be increased as necessary to gradually cool the glass film.

[0120] The glass film 400 carried into the tension adjustment zone 410 enters the differential exhaust zone 464 via a free roll 461, a dancer roll 462, and a tension roll 463. When cutting the glass film after deposition, the transport of the glass film is intermittently stopped, and at that time, the transport tension is detected by the tension roll 463 and the position of the dancer roll 462 is adjusted up or down to maintain the set tension.

[0121] The glass film 400 passes through macaroni packings (hollow packings) 465, 466 located before and after the differential exhaust zone 464 and enters a cutting zone 467. By stopping film formation and transportation and sandwiching the glass film after film formation between these macaroni packings (hollow packings) 465, 466, it may be possible to take out the glass film after film formation after cutting, i.e., the glass film with a near-infrared shielding film, without releasing the vacuum in the main body of the roll-to-roll sputtering apparatus to the atmosphere.

[0122] The glass film 400 is sandwiched between a motor-driven roll 468 and a nip roll 469, and is cut by, for example, a laser beam 471 irradiated from a laser device 470, and a glass film with a near-infrared shielding film 473 cut into a sheet shape is stacked on a tray 472. An interleaf film may be inserted when stacking the glass films with a near-infrared shielding film 473. The cutting may be performed by intermittently stopping the film, or the beam position may be obliquely scanned in accordance with the transport speed.

[0123] 5. Method for producing near-infrared shielding film laminate As described above, the near-infrared shielding film laminate according to the present invention is composed of a transparent substrate that transmits visible light, and the above-mentioned near-infrared shielding film-coated glass film laminated on the transparent substrate.

[0124] Here, the transparent substrate refers to a substrate having a visible light transmittance of 5% or more. If the visible light transmittance of a transparent substrate is 5% or more, it is possible to see the outside from inside the room, although it is difficult to see inside the room from outside.

[0125] (1) Long glass film with near infrared shielding coating FIG. 6 is a process explanatory diagram showing a process for producing a near-infrared shielding film laminate 515 by continuously bonding long glass films 501 and 502 with a near-infrared shielding film to both sides of a transparent substrate 500. As shown in FIG.

[0126] That is, both sides of the transparent substrate 500 are activated in a vacuum using ion beam or plasma treatment devices 504 and 506, and one side of the near-infrared shielding glass films 501 and 502 is activated using ion beam or plasma treatment devices 503 and 505; alternatively, both sides of the transparent substrate 500 are activated in the atmosphere using atmospheric pressure plasma treatment or corona treatment devices 504 and 506, and one side of the near-infrared shielding glass films 501 and 502 is activated using atmospheric pressure plasma treatment or corona treatment devices 503 and 505. One side of the glass films with near-infrared shielding film 501, 502 is subjected to an activation treatment to expose each activated side, and the long glass films with near-infrared shielding film 501, 502 are guided by guide rolls 507, 508, 509, 510 to both sides of the transparent substrate 500, and the glass films with near-infrared shielding film 501, 502 are bonded to both sides of the transparent substrate 500 by temperature-controlled rotating hot rolls 511, 512, 513, 514, thereby producing a near-infrared shielding film laminate 515.

[0127] Incidentally, the near-infrared shielding film laminate 515 shown in FIG. 6 has a structure in which glass films with near-infrared shielding film 501, 502 are bonded to both sides of a transparent substrate 500, but the near-infrared shielding film-coated glass film may be bonded to only one side of the transparent substrate 500 as long as the optical properties are satisfied.

[0128] (2) Cut glass film with near-infrared shielding coating FIG. 7 is a process explanatory diagram showing a process for manufacturing a near-infrared shielding film laminate 606 by bonding cut glass films 601 and 602 with a near-infrared shielding film to both sides of a transparent substrate 600. As shown in FIG.

[0129] That is, both sides of the transparent substrate 600 are activated in vacuum using an ion beam or plasma treatment device, and one side of the glass films with near-infrared shielding film 601, 602 are activated using an ion beam or plasma treatment device; alternatively, both sides of the transparent substrate 600 are activated in air using an atmospheric pressure plasma treatment or corona treatment device, and one side of the glass films with near-infrared shielding film 601, 602 are activated using an atmospheric pressure plasma treatment or corona treatment device to expose each activated side; and a structure in which the glass films with near-infrared shielding film 601, 602 are superimposed on both sides of the transparent substrate 600 is placed on a temperature-controlled hot plate 603, and the glass films with near-infrared shielding film 601, 602 are bonded to both sides of the transparent substrate 600 using temperature-controlled rotating hot rolls 604, 605 and the hot plate 603, thereby producing a near-infrared shielding film laminate 606.

[0130] In addition, the near-infrared shielding film laminate 606 shown in Figure 7 also has a structure in which the glass films 601 and 602 with near-infrared shielding film are bonded to both sides of the transparent substrate 600, but it may also have a structure in which the glass film with near-infrared shielding film is bonded to only one side of the transparent substrate 600 as long as the optical properties are satisfied.

[0131] The near-infrared shielding film laminate, which is 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 heat ray reflective member that reflects light in the near-infrared region in windows of automobiles and buildings, etc. EXAMPLES

[0132] EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

[0133] (1)Measurement method (1-1) Surface resistance The surface resistance of the film was measured using Loresta-GX manufactured by Mitsubishi Chemical Corporation. (1-2) Film Thickness The film thickness was measured using an optical profiler (Zygo NewView6200). (1-3) Maximum transmittance in the visible light range and reflectance at a wavelength of 1400 nm The optical properties of the obtained film were measured using a spectrophotometer V-670 (manufactured by JASCO Corp.), including transmittance and 8° incident diffuse reflectance.

[0134] From the measurement results, the maximum transmittance in the visible light range (wavelengths of 380 nm or more and 780 nm or less) was determined.

[0135] [Examples 1-10] (Target manufacturing process) A cesium carbonate aqueous solution and tungsten trioxide hydrate were mixed and kneaded in a ratio of cesium (Cs) to tungsten (W) mass ratio of Cs / W = 0.33, and then dried in air at 100°C for 12 hours to prepare a precursor.

[0136] The above precursor was heated to 800°C in a 5% by volume H2-95% by volume N2 gas flow and held for 1 hour, and then slowly cooled to room temperature to obtain a dark blue composite tungsten oxide powder (hereinafter referred to as CsWO powder).

[0137] The CsWO powder was placed in a hot press and heated in a vacuum atmosphere at a temperature of 950°C and a pressure of 250 kgf / cm. 2 The mixture was sintered under the above conditions to produce a CsWO sintered body.

[0138] As a result of chemical analysis of the composition of the sintered body, the ratio of the amounts of Cs and W, Cs / W, was 0.33.

[0139] This oxide sintered body was machined to a diameter of 20 mm and a thickness of 4 mm to prepare a CsWO target tablet.

[0140] (Film forming process) In the film formation process, a roll-to-roll sputtering device shown in FIG. 4 was used.

[0141] The glass film 300 has a thickness of 50 μm, a width of 500 mm, and a length of 100 m.

[0142] Eight cathodes are arranged around the process roll 336. The first cathode 337 to the sixth cathode 342 are used for forming the near-infrared shielding film. 0.33 A target made of WO3 powder was attached.

[0143] The seventh cathode 343 and the eighth cathode 344 were equipped with metal oxide targets for forming the bonding layer shown in Table 2. No metal oxide targets were equipped in Examples 7 to 10. Even if a metal oxide target was used during the deposition of the bonding layer, the oxygen partial pressure during the deposition was controlled to 2 Pa in order to compensate for the lack of oxygen.

[0144] A dual magnetron sputtering system using a 40Hz medium-frequency pulse power supply was used for each target in pairs. By controlling the amount of oxygen inserted so that the voltage or current value of the medium-frequency pulse power supply in this dual magnetron sputtering system was constant, it was possible to obtain an oxide film at a film formation speed close to that of the metal mode, in a transition mode between the metal mode (fast film formation speed but insufficient oxidation) and the oxide mode (slow film formation speed).

[0145] The temperature of the Procellol 336 was controlled at 200° C. by a heat medium.

[0146] Through a series of operations, the unheated films and bonding layers according to Examples 1 to 10 were formed.

[0147] (Heat treatment process) In this embodiment, the glass film 300 on which the non-heat treated film was formed was allowed to stay in the 3 m annealing zone 308 for 6 minutes, so the conveying speed of the glass film 300 was set to 0.5 m / min, and the temperature in the annealing zone 308 was controlled to 600°C.

[0148] Heaters 349 and 350 in the annealing zone 308 were SiC heaters, and heaters 351 and 352 were halogen heaters.

[0149] The glass film 300 with a near-infrared shielding film that had passed through the annealing zone 308 was cooled by passing through a motor-driven cooling roll 360, and then taken up around a take-up roll 361. In addition, a PET film was used as a carrier film (interleaving film) 364 when the glass film 300 with a near-infrared shielding film was taken up around the take-up roll 361.

[0150] (Laminating process) (1) Examples 1 to 6 The thicknesses of composite tungsten oxide films (Cs 0.33 A glass film with a near-infrared shielding film made of WO3) was bonded to a float glass (plate glass) having a substrate thickness of 3 mm via a bonding layer under the bonding conditions shown in Table 2 (presence or absence of a bonding layer, atmosphere, surface treatment, bonding temperature, bonding pressure, one-sided or both-sided), to produce the near-infrared shielding film laminate of Examples 1 to 6.

[0151] (2) Examples 7 to 8 The thicknesses of composite tungsten oxide films (Cs 0.33 A glass film with a near-infrared shielding film made of WO3) was bonded to a float glass (plate glass) having a substrate thickness of 3 mm without a bonding layer under the bonding conditions shown in Table 2 (presence or absence of a bonding layer, atmosphere, surface treatment, bonding temperature, bonding pressure, one-sided or both-sided), to produce the near-infrared shielding film laminate of Examples 7 to 8.

[0152] (3) Examples 9 to 10 The thicknesses of composite tungsten oxide films (Cs 0.33A glass film with a near-infrared shielding film made of WO3) was bonded to a polycarbonate plate having a substrate thickness of 3 mm without a bonding layer under the bonding conditions shown in Table 2 (presence or absence of a bonding layer, atmosphere, surface treatment, bonding temperature, bonding pressure, one-sided or both-sided), to produce near-infrared shielding film laminates of Examples 9 to 10.

[0153] (4) Optical properties and surface resistance The optical properties (maximum transmittance in the visible wavelength range, reflectance at a wavelength of 1400 nm) and surface resistance value of the near-infrared shielding films and near-infrared shielding film laminates according to Examples 1 to 10 were measured.

[0154] The results are shown in Table 2.

[0155] (evaluation) The near-infrared shielding film laminates according to Examples 1 to 10 have a maximum transmittance in the visible wavelength region of 5% or more and a reflectance at a wavelength of 1400 nm of 30% or more. 5 It is confirmed that it has characteristics of Ω / □ or higher.

[0156] Furthermore, the glass films with near-infrared shielding film of the near-infrared shielding film laminates according to Examples 1 to 10 are efficiently manufactured using the roll-to-roll sputtering apparatus shown in FIG. 4, and it is also confirmed that the cost of the near-infrared shielding film laminate can be reduced.

[0157] [Table 1]

[0158] [Table 2] [Industrial Applicability]

[0159] According to the method of the present invention, a glass film having a thickness of 200 μm or less is applied to a substrate on which a near-infrared shielding film made of a composite tungsten oxide is formed, and the glass film is rolled up and can be continuously transported by a roll-to-roll method. This makes it possible to efficiently produce a composite tungsten oxide film that functions as a heat ray shielding film, and the method has industrial applicability for use as windows for automobiles and buildings where heat ray shielding and radio wave transmittance are required. [Explanation of symbols]

[0160] 10: Plate glass 11, 12: Near infrared shielding film 100: Transparent substrate 100A: Near infrared shielding film laminate 101, 102: Glass film 101A, 102A: Glass film with near infrared shielding film 103, 104: Near infrared shielding film 200: Transparent substrate 200A: Near infrared shielding film laminate 201, 202: Glass film 201A, 202A: Glass film with near-infrared shielding coating 203, 204: Near infrared shielding film 205, 206: Bonding layer 207, 208: Bonding layer 300: Glass film 300A: Glass film with carrier film 301: Carrier film (interleaving film) 302: Unwinding Zone 303:Transportation Zone 304: Heater Zone 305:Transportation Zone 306: Surface treatment zone 307: Film formation process zone 308: Annealing Zone 309: Conveyor cooling zone 310: Winding zone 311: Glass film unwinding roll with carrier film 312: Carrier film winding roll 313: Touch Roll 314:Freeroll 315: Tension roll 316: Motor-driven roll 317, 318: Freeroll 319: Tension roll 320, 321, 322, 323: Heater 324, 325, 326, 327: Freeroll 328: Motor-driven roll 329, 330: Freeroll 331: Tension roll 332, 333: Surface treatment equipment 334:Freeroll 335: Motor-driven roll 336: Process roll 337, 338, 339, 340, 341, 342, 343, 344: sputtering cathodes 345: Tension roll 346:Freeroll 347:Freeroll 348: Tension roll 349, 350, 351, 352: Heater 353: Driving roll 354, 355, 356: Freeroll 357: Tension roll 358, 359: Freeroll 360: Motor-driven cooling roll 361: Glass film with near infrared shielding coating and carrier film, roll 362: Carrier film unwinding roll 363: Tension roll 364: Career Film 365:Freeroll 366: Touch Roll 400: Glass film 400A: Glass film with carrier film 401: Carrier film (interleaving film) 402: Unwinding Zone 403:Transportation Zone 404: Heater Zone 405:Transportation Zone 406: Surface treatment zone 407: Film formation process zone 408: Annealing Zone 409: Conveyor cooling zone 410: Tension adjustment zone 411: Glass roll film unwinding roll with carrier film 412: Carrier film winding roll 413: Touch Roll 414:Freeroll 415: Tension roll 416: Motor-driven roll 417, 418: Freeroll 419: Tension roll 420, 421, 422, 423: Heater 424, 425, 426, 427: Freeroll 428: Motor-driven roll 429, 430: Freeroll 431: Tension roll 432, 433: Surface treatment equipment 434:Freeroll 435: Motor-driven roll 436: Process roll 437, 438, 439, 440, 441, 442, 443, 444: Sputtering cathodes 445: Tension roll 446:Freeroll 447:Freeroll 448: Tension roll 449, 450, 451, 452: Heater 453: Driving roll 454, 455, 456: Freeroll 457: Tension roll 458, 459: Freeroll 460: Motor-driven cooling roll 461:Freeroll 462: Dancer Roll 463: Tension roll 464: Differential pumping zone 465, 466: Macaroni packing (hollow packing) 467: Cut Zone 468: Motor-driven roll 469: Nip roll 470: Laser device 471: Laser beam 472: Tray 473: Glass film with near-infrared shielding membrane cut into sheets 500: Transparent substrate 501, 502: Glass film with near infrared shielding film 503, 504, 505, 506: Ion beam or plasma treatment device, or atmospheric pressure plasma treatment or corona treatment device in the atmosphere 507, 508, 509, 510: Guide rolls 511, 512, 513, 514: Hot roll 515: Near infrared shielding film laminate 600: Transparent substrate 601, 602: Glass film with near infrared shielding coating 603: Hot plate 604, 605: Hot roll 606: Near infrared shielding film laminate

Claims

1. A glass film having a thickness of 200 μm or less; a near-infrared shielding film formed on at least one surface of the glass film, the near-infrared shielding film being made of a composite tungsten oxide having a hexagonal crystal structure represented by a general formula MxWyOz (wherein 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); A glass film with a near-infrared shielding film, characterized in that the near-infrared shielding film has a maximum transmittance of 5% or more in a visible light region having 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 at a wavelength of 1,400 nm.

2. 2. The glass film with a near-infrared shielding film according to claim 1, wherein the near-infrared shielding film has a thickness of 10 nm or more and 500 nm or less.

3. The surface resistance of the near infrared ray shielding film is 10 5 3. The glass film with a near-infrared shielding film according to claim 1, wherein the resistance of the glass film with a near-infrared shielding film is Ω / □ or more.

4. 2. The glass film with a near-infrared shielding film according to claim 1, further comprising an adhesive layer formed on a surface of the near-infrared shielding film.

5. The bonding layer is made of SiO 2 , Al 2 O 3 , ZrO 2 , TiO 2 , HfO 2 The infrared shielding film-attached glass film according to claim 4, characterized in that the glass film is composed of an oxide selected from the group consisting of:

6. A transparent substrate that transmits visible light; A near-infrared shielding film laminate comprising the transparent substrate and the glass film with a near-infrared shielding film according to claim 1 or 4 laminated thereon.

7. 7. The near-infrared shielding film laminate according to claim 6, wherein the transparent substrate is made of an inorganic material selected from plate glass or transparent ceramics, or an organic material selected from a resin film or a resin plate.

8. The method for producing a glass film with a near-infrared shielding film according to claim 1, A glass film unwinding process of unwinding a glass film having a thickness of 200 μm or less wound around an unwinding roll; a film formation step of forming a composite tungsten oxide film represented by a general formula MxWyOz (wherein 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) on at least one surface of the glass film unwound from a winding roll while transporting the glass film in a roll-to-roll manner by a film formation means; a heat treatment step of heat-treating the glass film on which the composite tungsten oxide is formed at a temperature equal to or lower than the strain point of the glass film to form a near-infrared shielding film made of a composite tungsten oxide having a hexagonal crystal structure; A method for producing a glass film with a near-infrared shielding film, comprising the steps of:

9. 9. The method for producing a glass film with a near-infrared shielding film according to claim 8, characterized in that, in the heat treatment step, the glass film on which the composite tungsten oxide is formed is sequentially heat-treated using a plurality of heat treatment means, and the first heat treatment means is composed of an infrared heater that emits infrared rays with a wavelength of 1500 nm or more.

10. The method for producing a glass film with a near-infrared shielding film according to claim 9, wherein the first heat treatment means is composed of a carbon heater or a SiC heater.

11. The method for producing the near infrared shielding film laminate according to claim 6, A method for producing a near-infrared shielding film laminate, comprising a thermocompression bonding step of thermocompression bonding a glass film with a near-infrared shielding film according to claim 1 or 4 and a transparent substrate made of the organic material according to claim 7.

12. The method for producing the near infrared shielding film laminate according to claim 6, 10. A method for producing a near-infrared shielding film laminate, comprising: a surface activation step of activating at least one surface of a glass film with a near-infrared shielding film according to claim 1 or 4 and a transparent substrate made of the inorganic material according to claim 7; and a bonding step of bonding the glass film with a near-infrared shielding film and the transparent substrate via the activated surface.

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