Glass substrate with thermal insulation film

Abstract

The present invention relates to a glass substrate (1) with a thermal insulation film, which is a glass substrate (1) with a thermal insulation film having a glass plate (11) and a thermal insulation film (12) arranged on one surface of the glass plate, wherein the glass substrate with a thermal insulation film has an electric wave transmission loss of 80 GHz below 5 dB, a transmittance of 900 nm above 15%, and an average reflectivity of 5 to 15 μm above 25%.

Description

Technical Field

[0001] The invention relates to a glass substrate with a heat insulation film.

[0002] This application claims priority based on Japanese Patent Application No. 2020-192038 filed in Japan on November 18, 2020, the contents of which are incorporated herein by reference. Background Art

[0003] With the development of ADAS (Advanced Driver-Assistance Systems) technology, more and more sensor-related devices are installed inside the car (inside the glass). Therefore, in addition to the radio wave permeability of AM, FM, TV, etc., automotive glass is also required to have light permeability of visible light cameras, millimeter wave radars, LiDar, raindrop sensors, etc.

[0004] In addition, automobile glass is also required to have high heat insulation due to the increasing demand for fuel consumption restrictions and energy saving. As radio wave penetrating heat-insulating glass, a glass article (heat-insulating glass) has been proposed, which includes a glass plate of a specified plate thickness and a film containing an infrared absorber provided on one main surface of the glass plate, and the average transmittance at a wavelength of 1000 nm is 18 to 30%, and the average transmittance at a wavelength of 1500 nm is 25 to 40% (Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2017-145162 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] However, if the transmittance in the near-infrared region near a wavelength of 1000 nm is reduced, the sensitivity of infrared sensors etc. cannot be obtained. Therefore, the glass article of Patent Document 1 has the problem of difficulty in simultaneously achieving high radio wave transmittance, high transmittance in the near-infrared region and high heat insulation.

[0010] The present invention provides a glass substrate with a heat-insulating film which can simultaneously achieve high radio wave transmittance, high transmittance in the near-infrared region, and high heat-insulating property.

[0011] Solutions to technical problems

[0012] The present invention has the following aspects.

[0013] [1] A glass substrate with a thermal insulation film, comprising a glass plate and a thermal insulation film provided on one surface of the glass plate,

[0014] The glass substrate with the heat-insulating film has an electric wave penetration loss of less than 5 dB at a frequency of 80 GHz, a transmittance of more than 15% at a wavelength of 900 nm, and an average reflectivity of more than 25% at a wavelength of 5 to 15 μm.

[0015] [2] The glass substrate with a thermal insulation film according to [1], wherein the surface resistivity of the thermal insulation film is greater than or equal to 10 Ω / sq. 9 Ω / sq or less, when the surface resistivity is set to R and the film thickness of the thermal insulation film is set to d (μm), the following formula (1) is satisfied:

[0016] R<10000exp(14.093×d)···(1).

[0017] [3] The glass substrate with a thermal insulation film according to [1] or [2], wherein the thermal insulation film has a thickness of 5 μm or less.

[0018] [4] The glass substrate with a thermal insulation film according to any one of [1] to [3], wherein the thermal insulation film contains at least one selected from metal oxide particles and conductive polymers as a conductive component.

[0019] [5] The glass substrate with a thermal insulation film according to [4], wherein the conductive polymer has an aromatic ring structure.

[0020] [6] The glass substrate with a thermal insulation film according to [4] or [5], wherein the thermal insulation film is a film having a content of the conductive component of 50% by mass or more.

[0021] [7] The glass substrate with a thermal insulation film according to any one of [1] to [6], wherein the thermal insulation film is provided on the entire surface of a region of one surface of the glass plate that is irradiated with sunlight.

[0022] [8] The glass substrate with a thermal insulation film according to any one of [1] to [7], wherein the glass plate is a vehicle window glass.

[0023] Effects of the Invention

[0024] The glass substrate with a heat-insulating film of the present invention can simultaneously achieve high radio wave transmittance, high transmittance in the near-infrared region, and high heat-insulating property. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram showing the structure of the glass substrate with a heat-insulating film according to the present embodiment. DETAILED DESCRIPTION

[0026] Hereinafter, the structure of the glass substrate with a heat-insulating film which is one embodiment to which the present invention is applied will be described.

[0027] The following definitions of terms apply throughout this specification and claims.

[0028] The thickness of the glass plate and the film thickness of the thermal insulation film are geometric thickness.

[0029] " to " indicating a numerical range includes the numerical values ​​described before and after it as the upper limit and the lower limit.

[0030] like Figure 1 As shown, the glass substrate with thermal insulation film 1 of this embodiment comprises a glass plate 11 and a thermal insulation film 12 provided on one surface of the glass plate. The glass substrate with thermal insulation film has a radio wave transmission loss of 5 dB or less at a frequency of 80 GHz, a transmittance of 15% or more at a wavelength of 900 nm, and an average reflectivity of 25% or more at a wavelength of 5 to 15 μm.

[0031] Examples of the material of the glass plate include soda-lime glass, aluminosilicate glass, alkali-free glass, and borosilicate glass, and soda-lime glass is preferred.

[0032] The glass plate may be strengthened. The strengthening method is not limited and may be physical strengthening or chemical strengthening.

[0033] The thickness of the glass plate is appropriately set according to the purpose of the glass substrate with thermal insulation film. When the glass substrate with thermal insulation film is used as a vehicle window glass, the thickness of the glass plate is preferably 2.0 to 6.0 mm, more preferably 2.5 to 5.5 mm, and further preferably 2.8 to 5.0 mm. When the thickness of the glass plate is within the above preferred range, it is easy to fully ensure the radio wave transmittance, the light transmittance in the visible light region and the near-infrared region. The thickness of the glass plate can be measured by the confocal displacement meter "Confocal IFC2461MP" ​​manufactured by Micro Epsilon. The thickness is measured at 5 randomly selected points of the glass plate, and the average value of the 5 points is taken as the thickness of the glass plate.

[0034] The thermal insulation film blocks (reflects) mid-infrared to far-infrared wavelengths of 5 to 15 μm, and has high radio wave transmittance, and high light transmittance in the visible light region and near-infrared region.

[0035] The surface resistivity of the thermal insulation film is above 10Ω / sq10 9 Ω / sq or less, when the surface resistivity is defined as R and the film thickness of the thermal insulation film is defined as d (μm), the film thickness d is within the range of 0.05 to 5 μm and preferably satisfies the following formula (1).

[0036] R<10000exp(14.093×d)···(1)

[0037] The surface resistivity of the thermal insulation film can be measured using a resistivity meter in accordance with JIS K 7194 (1994).

[0038] The surface resistivity of the thermal insulation film is 10 9 When the reflectivity is Ω / sq or less, it is easy to obtain high reflectivity in the mid-infrared region to the far-infrared region with a wavelength of 5 to 15 μm even if the film thickness of the thermal insulation film is thin.

[0039] When the surface resistivity of the thermal insulation film is 10Ω / sq or more, it is easy to ensure high radio wave penetration.

[0040] According to the research conducted by the inventors of the present application, it has been confirmed that as the surface resistivity R of the thermal insulation film increases, the film thickness d required to obtain the reflectivity in the mid-infrared region to the far-infrared region with a wavelength of 5 to 15 μm increases. 9 Even if the film thickness of Ω / sq is increased, high reflectivity in the mid-infrared region to the far-infrared region cannot be obtained. A thermal shielding film satisfying the above formula (1) can easily obtain high reflectivity in the mid-infrared region to the far-infrared region within a predetermined film thickness range.

[0041] The surface resistivity of the thermal insulation film is preferably above 10Ω / sq. 9 Ω / sq or less, more preferably 10 2 Ω / sq above 10 8 Ω / sq or less, more preferably 10 4 Ω / sq above 10 8 Ω / sq or less.

[0042] The film thickness of the thermal insulation film is preferably 5 μm or less, more preferably 1.5 μm or less, and further preferably 1 μm or less. The film thickness of the thermal insulation film is preferably 50 nm or more. The film thickness of the thermal insulation film is preferably 50 nm or more and 5 μm or less, more preferably 50 nm or more and 1.5 μm or less, and further preferably 50 nm or more and 1 μm or less. When the film thickness of the thermal insulation film is within the above range, it is easy to obtain the surface resistivity required for obtaining the reflectivity in the mid-infrared region to the far-infrared region with a wavelength of 5 to 15 μm. Furthermore, when the film thickness of the thermal insulation film is 5 μm or less, the raw materials used in forming the thermal insulation film can be reduced, and the economic efficiency is excellent.

[0043] The film thickness of the heat-insulating film can be measured using a stylus-type surface profile measuring instrument on a glass substrate with the heat-insulating film.

[0044] The thermal insulation film preferably contains at least one selected from metal oxide particles and conductive polymers as a conductive component.

[0045] Examples of the metal oxide particles include tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), composite tungsten oxide, fluorine-doped tin oxide (FTO), etc. ITO and ATO are preferred from the perspective of near infrared transmittance at a wavelength of about 1000 nm. The particle size of the metal oxide particles may be 1 to 150 nm as the average primary particle size, and more preferably 5 to 100 nm.

[0046] In addition, the average primary particle size of the metal oxide particles can be measured by a commercially available nanoparticle size measuring device: "Nanotrac Wave II" manufactured by Microtrak Co., Ltd. based on a dynamic scattering method. Specifically, a volume-based cumulative particle size distribution curve is obtained by the dynamic scattering method, and the particle size value at the time of 50% accumulation from the microparticle side in the obtained cumulative particle size distribution curve is taken as the average primary particle size.

[0047] The metal oxide particles may also chemically bond or adsorb compounds having reactive groups, compounds having hydrogen-bonding functional groups, and compounds having hydrogen atom functional groups (hereinafter, these compounds are collectively referred to as "compounds having reactive groups, etc.") on the surface. By forming bonds between particles due to the presence of compounds having reactive groups on the surface of the particles, it is easy to obtain a thermal insulation film with excellent wear resistance or scratch resistance.

[0048] Examples of the reactive group include an amino group, an epoxy group, an acryloyl group, a methacryloyl group, a vinyl group, a mercapto group, an isocyanate group, a carboxyl group, a hydroxyl group, a phenol group, a nitrile group, an imino group, a halogen group, a urea group, and an isocyanurate group.

[0049] Examples of the functional group having a hydrogen bonding property include an amino group, an epoxy group, an ether group, an isocyanate group, a carbonyl group, a carboxyl group, a hydroxyl group, a phenol group, a nitrile group, an imino group, a urea group, and an isocyanurate group.

[0050] Examples of the functional group having a hydrogen atom include an amino group, a hydroxyl group, a phenol group, a mercapto group, and a carboxyl group.

[0051] The reactive groups and functional groups of the compounds present on the surface of the particles may be different for each particle. For example, by separately including particles having a compound having an amino group on the surface and particles having an epoxy group on the surface, the particles may be bonded to each other by the reaction between the amino group and the epoxy group. Conversely, the reactive groups of the compounds present on the surface of the particles may be a single type, for example, particles having a compound having an acryloyl group on the surface may be bonded to each other by the reaction between the acryloyl groups.

[0052] In addition, it is preferred to include particles of a compound having a hydrogen-bonding functional group on the surface and particles of a compound having a hydrogen atom on the surface. In this case, the hydrogen-bonding functional group and the hydrogen atom of the hydrogen-bonding functional group form a bond between the particles.

[0053] The method for chemically bonding the compound having a reactive group, the compound having a hydrogen-bonding functional group, and the compound having a hydrogen atom functional group to the particle surface is not particularly limited, but a method using a silane coupling agent can be considered. A silane coupling agent containing any one or more of a reactive group such as an amino group or an epoxy group, a hydrogen-bonding functional group, and a hydrogen atom functional group is added to a dispersion of metal oxide particles together with an alkali component such as NaOH, KOH, and NH3 or an acid component such as sulfuric acid, nitric acid, hydrochloric acid, acetic acid, and maleic acid, and stirred, so that the silane coupling agent is bonded to the surface of the metal oxide particles and the reactive group is present on the particle surface.

[0054] The metal oxide particle surface may be entirely or partially coated with the compound having a reactive group, etc. The coverage of the compound having a reactive group, etc. relative to the total surface area of ​​the metal oxide particle is preferably 5 to 90%, more preferably 10 to 80%, and even more preferably 20 to 70%.

[0055] The coverage can be measured by observing an image using a transmission electron microscope: HT7700 manufactured by Hitachi.

[0056] When the entire surface of the metal oxide particle is coated with a compound having a reactive group, the surface resistance of the thermal insulation film may become too high if the coating layer is too thick. Therefore, the thickness of the coating layer on the surface of the metal particle is preferably 5 nm or less, more preferably 3 nm or less, and particularly preferably 1 nm or less. The thickness of the coating layer is preferably 0.1 to 5 nm, more preferably 0.3 to 3 nm, and further preferably 0.5 to 1 nm.

[0057] The thickness of the coating layer can be measured by observing an image using a transmission electron microscope: HT7700 manufactured by Hitachi.

[0058] The content of the compound having a reactive group is preferably 0.5 to 50% by mass, more preferably 1 to 30% by mass, and particularly preferably 3 to 15% by mass relative to the total mass of the metal oxide particles and the compound having a reactive group. In addition, in the case of the compound having a reactive group, its structure changes due to the reaction, but when calculating the above content, the total mass of the unit derived from the compound after the change by the reaction is used.

[0059] Conductive polymers include poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonic acid) (also referred to as PEDOT / PSS), polyacetylene, polyaniline, polypyrrole, polythiophene, and the like. From the viewpoint of air stability, those having an aromatic ring structure (PEDOT / PSS) and polythiophene are preferred.

[0060] The content of the conductive component contained in the thermal insulation film is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, and particularly preferably 90% by mass or more, relative to the total mass of the solid content of the thermal insulation film. The content of the conductive component contained in the thermal insulation film is preferably 50 to 100% by mass or more, more preferably 60 to 99% by mass or more, further preferably 70 to 98% by mass or more, and particularly preferably 90 to 97% by mass or more, relative to the total mass of the solid content of the thermal insulation film.

[0061] When a compound having a reactive group or the like is present on the surface of the metal oxide particles, the content of the conductive component is the amount of only the metal oxide particles.

[0062] When the content of the conductive component in the thermal insulation film is 50 mass % or more, the surface resistivity of the thermal insulation film can easily reach 10 9 Furthermore, if the content is 90% by mass or more, it is easy to achieve a film thickness of 10 μm or less. 9 Surface resistivity below Ω / sq.

[0063] The thermal insulation film may further contain a matrix component such as an alkoxysilane compound, an epoxy resin, an acrylic resin, or a phenolic resin within a range not impairing the effects of the present invention.

[0064] The content of the matrix component contained in the thermal insulation film is preferably less than 50% by mass, more preferably less than 40% by mass, further preferably less than 30% by mass, and particularly preferably less than 10% by mass relative to the total mass of the thermal insulation film. In the case where the matrix component is contained in the thermal insulation film, the content of the matrix component is preferably greater than 0% by mass and less than 50% by mass, more preferably 1% by mass or more and less than 40% by mass, further preferably 2% by mass or more and less than 30% by mass, and particularly preferably 3% by mass or more and less than 10% by mass relative to the total mass of the thermal insulation film. In addition, as another aspect of the present invention, the thermal insulation film preferably does not contain a matrix component.

[0065] In the case of a thermal insulation film using metal oxide particles, by combining a matrix component with the surface of the particles, a thermal insulation film with excellent wear resistance or scratch resistance can be easily obtained. The matrix component is adsorbed and chemically bonded to the surface of the metal oxide particles, thereby bonding to the surface of the particles. As a matrix component that can be chemically bonded to the surface of the metal oxide particles, a matrix component having a silanol group can be cited. In addition, the matrix component preferably has a reactive group. The reactive group in the matrix component bonded to the surface of the particle reacts to form a bond between the particles, and a thermal insulation film with excellent wear resistance and scratch resistance can be easily obtained. As reactive groups, silanol groups, hydroxyl groups, carbonyl groups, acryloyl groups, epoxy groups, etc. can be cited.

[0066] In addition to the matrix component, a component that crosslinks the metal oxide particles may also be included. As a crosslinking agent, a compound having two or more reactive functional groups in one molecule may be considered. As examples of compounds having the same reactive groups in one molecule, ethylenediamine, diethylenetriamine, etc. may be cited, and as compounds having different reactive groups in one molecule, silane coupling agents such as aminopropyltrimethoxysilane and glycidyloxypropyltrimethoxysilane may be cited.

[0067] The thermal insulation film may contain impurities (surface conditioner, particle dispersant, organic solvent, water, etc.) that are inevitably introduced during film formation.

[0068] The content of inevitable impurities contained in the thermal insulation film is preferably less than 50% by mass, more preferably less than 40% by mass, further preferably less than 30% by mass, and particularly preferably less than 10% by mass relative to the total mass of the thermal insulation film. When the thermal insulation film contains impurities, the content of the impurities is preferably greater than 0% by mass and less than 50% by mass, more preferably greater than 0% by mass and less than 40% by mass, further preferably greater than 0% by mass and less than 30% by mass, and particularly preferably greater than 0% by mass and less than 10% by mass relative to the total mass of the thermal insulation film. In addition, as another aspect of the present invention, the thermal insulation film preferably does not contain impurities.

[0069] The thermal insulation film may be a single layer or a combination (laminated) of two or more layers of different types. Specific examples include the following aspects (a) to (f).

[0070] (a) Monolayer containing one metal oxide particle

[0071] (b) Monolayer containing two or more metal oxide particles

[0072] (c) A single layer containing one conductive polymer

[0073] (d) A single layer containing two or more conductive polymers

[0074] (e) A monolayer containing at least one metal oxide particle and at least one conductive polymer

[0075] (f) Combination (lamination) of two or more layers among the layers of (a) to (e) above

[0076] The heat-insulating film is provided on one surface of the glass plate. In addition, the heat-insulating film is preferably provided on the entire surface of the area irradiated by sunlight in one surface of the glass plate. In addition, when the glass substrate with a heat-insulating film of the present embodiment is lifted and lowered in the vertical direction or slid (movable) in the horizontal direction and a part of the glass substrate with a heat-insulating film is stored in the storage part, the heat-insulating film may not be provided on the surface of the glass plate in the area stored in the storage part and the vicinity thereof.

[0077] The thermal insulation film of the glass substrate with thermal insulation film of this embodiment has high radio wave transmittance, high light transmittance in the visible light region and the near-infrared region. There is no need to set a non-thermal insulation film area (transmission area) on the surface of the glass plate, so the thermal insulation film is easy to form, and thus the productivity is excellent.

[0078] The thermal insulation film may further include a functional layer between the glass plate and the thermal insulation film as required, or may include a top layer on the surface of the thermal insulation film farthest from the glass plate, within a range not impairing the effects of the present invention.

[0079] The functional layer provided as needed is not particularly limited, and examples of the functional layer include a heat-reflecting film containing a metal nitride, a UV-cutting film containing an ultraviolet absorber, and an anti-fogging film containing a water-absorbing organic resin.

[0080] The thickness of the functional layer is preferably 1 nm to 50 μm, more preferably 5 nm to 30 μm, and particularly preferably 10 nm to 20 μm.

[0081] Top layer of protective insulation film set as needed.

[0082] Examples of the material of the top layer include silicon dioxide, titanium nitride, carbon, organic resins, and silane condensates.

[0083] The thickness of the top layer is preferably 1 to 50 nm, more preferably 1 to 20 nm, particularly preferably 1 to 10 nm.

[0084] The radio wave penetration loss of the heat-insulating film glass substrate of this embodiment at a frequency of 80 GHz is less than 5 dB, preferably less than 4 dB. It is preferably in the range of 0 to 5 dB, more preferably in the range of 0 to 4 dB, further preferably in the range of 0 to 3.5 dB, and particularly preferably in the range of 0 to 3.0 dB. When the radio wave penetration loss at a frequency of 80 GHz is less than 5 dB, it is easy to ensure the radio wave penetration required by millimeter wave radars, etc.

[0085] The radio wave transmission loss of the glass substrate with a heat shielding film can be measured by a free space method. The details of the measurement conditions will be described later in the examples.

[0086] In addition, the radio wave penetration loss of the heat-insulating film glass substrate of the present embodiment at frequencies of 80 GHz, 28 GHz and below 3.5 GHz is preferably 5 dB or less, more preferably 4 dB or less, further preferably 3.5 dB or less, and particularly preferably 3.0 dB or less. It is preferably in the range of 0 to 5 dB, more preferably in the range of 0 to 4 dB, further preferably in the range of 0 to 3.5 dB, and particularly preferably in the range of 0 to 3.0 dB. In addition, the radio wave penetration loss below 3.5 GHz can be determined, for example, by measuring the electromagnetic wave penetration loss at 2 GHz. By making the radio wave penetration loss at frequencies of 80 GHz, 28 GHz and below 3.5 GHz less than 5 dB, respectively, the radio wave penetration required by multiple information communication terminals such as millimeter wave radar, television, radio, satellite broadcasting, 5G, LTE, etc. can be simultaneously guaranteed.

[0087] In addition, the glass substrate with thermal insulation film in this embodiment is explained using the radio wave penetration loss of radio waves with frequencies below 80 GHz, 28 GHz and 3.5 GHz as an example, but is not limited to these frequency bands. It is preferred to obtain the same radio wave penetration loss as described above in the frequency band of about several hundred MHz to several tens of GHz.

[0088] The glass substrate with heat-insulating film of this embodiment preferably has a transmittance of 15% or more at a wavelength of 900nm, preferably in the range of 15 to 50%, and more preferably in the range of 20 to 40%. A transmittance of 15% or more at a wavelength of 900nm makes it easy to ensure the light transmittance in the near-infrared region required for infrared sensors and the like.

[0089] The transmittance of the glass substrate with a heat-insulating film at a wavelength of 900 nm can be measured using a spectrophotometer.

[0090] The average reflectivity of the glass substrate with a heat-insulating film of the present embodiment at a wavelength of 5 to 15 μm is 25% or more, preferably in the range of 30 to 70%, and more preferably in the range of 30 to 60%. The average reflectivity of 25% or more at a wavelength of 5 to 15 μm can ensure high reflectivity in the mid-infrared region to the far-infrared region, which is the region newly discovered by the inventors of the present application to exhibit heat-insulating properties.

[0091] The reflectivity of the glass substrate with a heat-insulating film at a wavelength of 5 to 15 μm can be measured using an infrared spectrophotometer equipped with a reflectivity measuring device. The average reflectivity at a wavelength of 5 to 15 μm can be calculated by measuring the reflectivity at a wavelength of 5 to 15 μm at every 5 nm wavelength.

[0092] The visible light transmittance of the glass substrate with heat shielding film of this embodiment is preferably 50 to 95%, more preferably 60 to 85%, and further preferably 70 to 75%. When the visible light transmittance is within the above range, the amount of transmitted light required for recognizing a transmitted image can be maintained and the heat shielding property can be improved.

[0093] The visible light transmittance of the glass substrate with a heat shielding film can be calculated according to JIS R3212 (1998) by measuring the transmittance of each wavelength with a spectrophotometer.

[0094] The glass substrate with a thermal insulation film of this embodiment can be manufactured by applying a liquid composition containing a conductive component on a glass plate, and then heating and drying the glass plate coated with the liquid composition, repeating the process once or more. In the manufacture of the glass substrate with a thermal insulation film, other processes may be included as needed. By drying, the liquid medium is removed from the liquid composition containing a conductive component, and a film containing a conductive component is formed on the surface of the glass plate.

[0095] When the conductive component includes metal oxide particles, the metal oxide particles are dispersed in a liquid medium to obtain a liquid composition prepared to an arbitrary solid content concentration. When the surface of the metal oxide particles is coated with the above-mentioned compound having a reactive group, it is preferred that the liquid composition contains a compound having a reactive group and an alkali component or an acid component.

[0096] When the conductive component includes a conductive polymer, the conductive polymer is dissolved or dispersed in a liquid medium to obtain a liquid composition prepared to an arbitrary concentration.

[0097] Examples of the liquid medium include ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and butyl acetate, alcohols such as methanol, ethanol, 1-propanol and 2-propanol, carboxylic acids such as acetic acid, nitriles such as acetonitrile, water, etc. These may be used alone or in combination of two or more.

[0098] The liquid composition may further include a matrix component such as an alkoxysilane compound, an epoxy resin, an acrylic resin, a phenolic resin, etc., within the range that does not impair the effect of the present invention. When the liquid composition includes a matrix component, the content of the matrix component in the liquid composition is preferably 50% by mass or less, more preferably 5 to 40% by mass, and further preferably 10 to 30% by mass relative to the total mass of the composition. In addition, the content of the matrix component is a solid component conversion content. In the present invention, the solid component conversion content of a component refers to the mass of the residue after removing volatile components such as water.

[0099] The liquid composition can be applied to the surface of the glass plate by conventional coating methods such as spin coating, dip coating, spray coating, flow coating, die coating, etc. Flow coating is particularly suitable for the case of a glass plate having a curved surface.

[0100] In the process of heating and drying the glass plate coated with the liquid composition, an electric furnace, a gas furnace, an infrared heating furnace, etc. can be used. The heating temperature and time can be adjusted appropriately. As the heating temperature, the range of 70 to 300° C. can be cited. In addition, as the heating time, 1 to 180 minutes can be cited.

[0101] The glass substrate with a heat insulating film according to the present embodiment can be used as heat insulating glass, for example, as a vehicle window glass.

[0102] The glass substrate with a heat-insulating film of the present embodiment can be used directly as a single plate, can be used for laminated glass, or can be used for multi-layer glass.

[0103] The laminated glass comprises a first transparent substrate, a second transparent substrate, and an intermediate film disposed between the transparent substrates. The heat-insulating film-coated glass substrate of the present invention can be used as either the first transparent substrate or the second transparent substrate.

[0104] The multilayer glass has a first transparent substrate, a second transparent substrate, and a frame-shaped spacer sandwiched between the first transparent substrate and the second transparent substrate to form a gap between the transparent substrates. The heat-insulating film-bearing glass substrate of the present invention can be used as either the first transparent substrate or the second transparent substrate.

[0105] When the glass substrate with a heat-insulating film of the present embodiment is used for laminated glass or multi-layer glass, the heat-insulating film is arranged on the inner side (the side in contact with the indoor room).

[0106] The above-described embodiment of the glass substrate with thermal insulation film has a radio wave transmission loss of 80 GHz of less than 5 dB, a transmittance of 900 nm of 15% or more, and an average reflectance of 5 to 15 μm of 25% or more. By making the transmittance of 900 nm, which is blocked to obtain the thermal insulation of the conventional thermal insulation film, greater than 15%, the transmittance of light in the near-infrared region required for infrared sensors and the like can be ensured. And by blocking (reflecting) the infrared region to the far-infrared region, which is the newly discovered thermal insulation region, the thermal insulation can be ensured. As a result, it is possible to provide a glass substrate that satisfies radio wave transmittance, transmittance in the near-infrared region, and thermal insulation at the same time.

[0107] In addition, in this embodiment, when the radio wave penetration loss at frequencies below 80 GHz, 28 GHz and 3.5 GHz of the thermal insulation film glass substrate is less than 4 dB, respectively, the radio wave penetration required by multiple information communication terminals such as millimeter wave radar, TV, radio, satellite broadcasting, 5G, LTE, etc. can be simultaneously guaranteed.

[0108] When the glass substrate with heat-insulating film of the present embodiment is used as a vehicle window glass, while maintaining heat insulation, radar sensors such as millimeter-wave radar, microwave radar, LiDAR, and raindrop sensor can function simultaneously without providing a transmission area in the area where the heat-insulating film is provided on the glass substrate. In addition, radars and sensors can be freely arranged without providing a transmission area in the area where the heat-insulating film is provided on the glass substrate.

[0109] In addition, the technical scope of the present invention is not limited to the above-mentioned embodiment, and various changes can be made within the scope that does not impair the effects of the present invention.

[0110] Example

[0111] The present invention is described in detail below by way of examples, but the present invention is not limited thereto. Examples 1 to 3 and 7 are examples, and Examples 4 to 6 are comparative examples.

[0112] (film thickness)

[0113] The film thickness (μm) of the thermal insulation film was measured for the glass substrate with the thermal insulation film using a stylus-type surface profile measuring instrument (ULVAC: Dektak150).

[0114] (Conductive component content)

[0115] Regarding the content of the conductive component contained in the thermal insulation film, when the thermal insulation film is formed using a liquid composition, the content of the conductive component relative to the total solid content contained in the prepared liquid composition is calculated.

[0116] In the case of a laminated film including two or more layers, the conductive component content when the entire laminated film is a thermal insulation film and the conductive component content when an arbitrary layer (single layer) is a thermal insulation film are calculated.

[0117] (Surface resistivity)

[0118] The surface resistivity (Ω / sq) of the glass substrate with a heat-insulating film was measured using a resistivity meter (Loresta GP manufactured by Mitsubishi Chemical Corporation) in accordance with JIS K7194 (1994).

[0119] (Radio wave penetration loss)

[0120] The radio wave transmission loss of the manufactured glass substrate with thermal insulation film was measured by a free space method.

[0121] The radio wave transmission loss was measured as follows: the antennas were placed opposite each other, and a glass substrate with a heat-insulating film was placed between them so that the direction of the opening extension and the direction of radio wave polarization were orthogonal. The case where there was no glass substrate with a heat-insulating film at an opening of 100 mm Φ was considered 0 dB, and the radio wave transmission loss for radio waves of frequencies of 2 GHz, 28 GHz, and 80 GHz was measured. In addition, the radio wave transmission loss was also measured separately for the glass plate before the heat-insulating film was formed.

[0122] (Transmittance at a wavelength of 900nm)

[0123] The transmittance (%) of the glass substrate with a heat-insulating film at a wavelength of 900 nm was measured using a spectrophotometer (U-4100 manufactured by Hitachi, Ltd.).

[0124] (Average reflectivity at wavelengths of 5 to 15 μm)

[0125] The reflectance of the glass substrate with a heat-insulating film at a wavelength of 5 to 15 μm was measured at every 5 nm wavelength using an infrared spectrophotometer (Japan Spectro Corporation: FT / IR-4600U-4100) equipped with a reflection measuring device (Japan Spectro Corporation: RF-81S), and the average value (%) was calculated.

[0126] (Visible light transmittance)

[0127] The transmittance of the glass substrate with a heat shielding film at each wavelength was measured using a spectrophotometer (manufactured by Hitachi, Ltd.: U-4100), and the visible light transmittance (Tv [%) was calculated in accordance with JIS R3212 (1998).

[0128] (Thermal insulation evaluation)

[0129] The heat insulation properties were evaluated by conducting a questionnaire survey on the burning sensation of 63 users using glass heated by a sun lamp, a ceramic heater, or a sheet heater, and irradiating the back of the hand with light having a wavelength of 0.8 to 20 μm through the glass.

[0130] The subjects used a feedback form to answer the feedback of hot and cold sensations before and after irradiation, as well as the subjective feedback of the feeling on the back of the hand caused by irradiation after irradiation.

[0131] The case where 50 or more people responded that the glass had better heat insulation than the glass without heat insulation film was rated as "A", while the case where less than 50 people responded that the glass had no better heat insulation than the glass without heat insulation film (no difference) was rated as "B".

[0132] (Wear resistance evaluation)

[0133] The wear resistance was measured using a reciprocating lateral motion tester (manufactured by KNT Co., Ltd.). A load of 500 g was applied with a flannel cloth to a wear surface of 1 cm×4 cm. The test was repeated 500 times and the appearance was visually observed. An A score was given if there were no scratches or peeling at all, and a B score was given if slight marks of friction were visible using reflected light.

[0134] (Example 1)

[0135] A liquid composition 1 obtained by diluting 5 g of an ITO dispersion (solid content concentration 20%) with 15 g of methanol was spin-coated on a 10 cm×10 cm×3.5 mmt high heat ray absorbing glass (AGC: UVFL) using a spin coater (MS-B200 manufactured by Mikasa Co., Ltd.) at a rotation speed of 100 rpm, and then dried at 150° C. for 3 minutes in an air atmosphere. Furthermore, the liquid composition 1 was spin-coated on the dried substrate under the same conditions, and the spin coating and drying were repeated 3 times in total to obtain a glass substrate with a thermal insulation film.

[0136] (Example 2)

[0137] A liquid composition 2 of poly(3,4-ethylenedioxythiophene) (PEDOT / PSS) (manufactured by Sigma-Aldrich) doped with poly(4-styrenesulfonic acid) was diluted with distilled water to a concentration of 1.3%, and was spin-coated on a 10 cm×10 cm×3.5 mmt high heat ray absorbing glass (manufactured by AGC: UVFL) using a spin coater (manufactured by Mikasa Co., Ltd.: MS-B200) at a rotation speed of 100 rpm, and then dried at 100°C in an air atmosphere for 30 minutes to obtain a glass substrate with a thermal insulation film.

[0138] (Example 3)

[0139] A glass substrate with a heat-insulating film was obtained by the same procedure as in Example 2 except that the rotation speed of the spin coating was changed from 100 rpm to 500 rpm.

[0140] (Example 4)

[0141] A high heat ray absorbing glass (manufactured by AGC: UVFL) of 10 cm×10 cm×3.5 mmt was used instead of forming a film.

[0142] (Example 5)

[0143] A 10 cm × 10 cm × 2.8 mm2 glass plate (AGC: FL) was introduced into an inline sputtering device and evacuated to a vacuum degree of 2 × 10 -6Torr or less, on the above glass plate surface, a film is formed until the total film thickness of the two layers of tin-doped zinc oxide and aluminum-doped zinc oxide reaches 43.5nm. Then, the following films are formed in sequence: silver film thickness 12.5nm, titanium 2nm, three layers in the order of aluminum-doped zinc oxide, tin-doped zinc oxide, and aluminum-doped zinc oxide with a total film thickness of 87.5nm, silver 12.5nm, titanium 2nm, two layers in the order of aluminum-doped zinc oxide and tin-doped zinc oxide with a total film thickness of 31.5nm, and titanium oxide 1nm. After film formation, the laminate is heat treated at 730°C in air for 4 minutes to obtain a glass substrate with a heat insulation film.

[0144] In addition, the content of the conductive component contained in the thermal insulation film was calculated by taking silver as the conductive component, and calculating the content in the entire laminated film and the content in a single silver layer.

[0145] (Example 6)

[0146] 2.05 g of 2,2',4,4'-tetrahydroxybenzophenone (manufactured by BASF), 5.14 g of 3-glycidyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.033 g of benzyltriethylammonium chloride (manufactured by Junsei Chemical Co., Ltd.), and 4.17 g of butyl acetate (manufactured by Junsei Chemical Co., Ltd.) were added, and the mixture was heated to 120° C. and stirred for 4 hours, and then cooled to room temperature. Next, 46.2 g of Solmix AP-1, 14.2 g of tetraethoxysilane (manufactured by Junsei Chemical Co., Ltd.), 0.87 g of SR-SEP (manufactured by Sakamoto Yakuin Kogyo Co., Ltd.), 18.4 g of pure water, 0.06 g of BYK307 (manufactured by BYK Chemical Co., Ltd.), 0.10 g of a 63% by mass aqueous nitric acid solution, and 0.012 g of maleic acid were added, and after stirring at 50° C. for 2 hours, 8.7 g of a dispersion of cesium oxide tungsten nanoparticles YMF-02A (manufactured by Sumitomo Metal Mining Co., Ltd.) was added to obtain a liquid composition 6.

[0147] The obtained liquid composition 6 was spin-coated on a 10 cm×10 cm×3.5 mmt high heat ray absorbing glass (AGC: UVFL) using a spin coater (MS-B200 manufactured by Mikasa Co., Ltd.) at a rotation speed of 50 rpm, and then dried at 200° C. for 30 minutes in an air atmosphere to obtain a glass substrate with a thermal insulation film.

[0148] (Example 7)

[0149] 5 g of ITO dispersion (solid content concentration 20%) was diluted with 15 g of methanol, and 0.14 g of 3-aminopropyltrimethoxysilane and 1.13 g of 1 mol / L NaOH aqueous solution were added and stirred to obtain surface-coated particle dispersion 1.

[0150] Similarly, 5 g of ITO dispersion (solid content concentration 20%) was diluted with 15 g of methanol, and 0.14 g of 3-glycidyloxypropyltrimethoxysilane and 1.13 g of 1 mol / L NaOH aqueous solution were added and stirred to obtain surface-coated particle dispersion 2.

[0151] The liquid composition obtained by mixing and stirring equal amounts of the surface coating dispersions 1 and 2 was formed on a 10 cm×10 cm×3.5 mmt high heat ray absorbing glass (AGC: UVFL) in the same manner as in Example 1 to obtain a glass substrate with a heat shielding film.

[0152] The obtained glass substrates with thermal insulation films of Examples 1 to 7 were subjected to measurement of the film thickness of the thermal insulation films, the content of the conductive component contained in the thermal insulation films, the surface resistivity, the radio wave transmission loss, the transmittance at a wavelength of 900 nm, the average reflectance at a wavelength of 5 to 15 μm, and the visible light transmittance (Tv), and thermal insulation evaluation. The results are shown in Table 1 below.

[0153] Table 1

[0154]

[0155] The glass substrate with thermal insulation film in Examples 1 to 3 and 7 has an electromagnetic wave transmission loss of less than 5 dB at a frequency of 80 GHz, a transmittance of more than 15% at a wavelength of 900 nm, and an average reflectivity of more than 25% at a wavelength of 5 to 15 μm. Therefore, it simultaneously meets the requirements of high electromagnetic wave penetrability, high penetrability in the near-infrared region, and high thermal insulation.

[0156] In particular, the glass substrate with a heat shielding film of Example 7 uses metal oxide particles having a compound having a reactive group on the surface as a conductive component, so that bonds are formed between the metal oxide particles through these compounds, and thus the wear resistance is excellent.

[0157] Since the glass substrate of Example 4 has no heat-insulating film, although it has radio wave transmittance and near-infrared transmittance, it cannot obtain high heat-insulating properties.

[0158] The glass substrate with thermal insulation film of Example 5 has a thermal insulation film with silver as a conductive component. Although it has thermal insulation for blocking the near-infrared region (900nm) which is one of the thermal insulation regions, it cannot obtain high radio wave permeability and high transmittance in the near-infrared region.

[0159] The glass substrate with a heat-insulating film of Example 6 has a heat-insulating film having cesium tungsten oxide as a conductive component. Although it has radio wave permeability and heat-insulating properties, it cannot obtain high permeability in the near-infrared region.

[0160] Industrial Applicability

[0161] The glass substrate with a heat-insulating film of the present invention can be used as heat-insulating glass for vehicle window glass and the like.

[0162] Explanation of symbols

[0163] 1 Glass substrate with thermal insulation film

[0164] 11 Glass Plate

[0165] 12 Thermal insulation film

Claims

1. A glass substrate with a thermal insulation film, comprising a glass plate and a thermal insulation film provided on one surface of the glass plate, in, The glass substrate with thermal insulation film has an electric wave penetration loss of less than 5 dB at a frequency of 80 GHz, a transmittance of more than 15% at a wavelength of 900 nm, and an average reflectivity of more than 25% and less than 70% at a wavelength of 5 to 15 μm.

2. The glass substrate with a thermal insulation film according to claim 1, wherein: The surface resistivity of the thermal insulation film is above 10Ω / sq. 9 Ω / sq or less, When the surface resistivity is set to R and the film thickness of the thermal insulation film is set to d (μm), the following formula (1) is satisfied: R<10000exp (14.093×d)・・・(1).

3. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: The film thickness of the thermal insulation film is less than 5 μm.

4. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: The thermal insulation film contains at least one selected from metal oxide particles and conductive polymers as a conductive component.

5. The glass substrate with a thermal insulation film according to claim 4, wherein: The conductive polymer has an aromatic ring structure.

6. The glass substrate with a thermal insulation film according to claim 4, wherein: The thermal insulation film is a film in which the content of the conductive component is 50 mass % or more.

7. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: The heat-insulating film is provided on the entire surface of a region of one surface of the glass plate that is irradiated by sunlight.

8. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: The glass plate is a vehicle window glass.

9. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: The average reflectivity is above 30%.

10. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: The average reflectivity is below 60%.

11. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: Visible light transmittance is 50-95%.

12. The glass substrate with a thermal insulation film according to claim 1 or 2, wherein: The transmittance at a wavelength of 900nm is 15-50%.

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