Glass and laminated glass

Abstract

Glass for a vehicle, comprising: a glass plate (22); a transparent area defined in the glass; and a light control element (25) which is arranged in at least a portion of an area of ​​the glass plate (22) which overlaps the transparent area in plan view and which is designed to switch the light transmission, wherein the light control element (25) a light control layer (253), a pair of conductive thin films (252, 254) surrounding the light control layer (253), wherein at least one of the pair of conductive thin films (252, 254) arranged on a vehicle outer side has a heat ray reflection function, and an energy reflectance of the transparent region is greater than or equal to 25%, a pair of light control bus bars (257) configured to supply current to the pair of conductive thin films (252, 254) so ​​as to operate the light control layer (253), and a pair of heating bus bars (256) configured to heat at least one of the pair of conductive thin films (252, 254).

Description

[Technical field]

[0001] The present invention relates to a glass and a laminated glass. [State of the art]

[0002] A vehicle has a transparent glass portion for safety purposes, allowing, for example, a passenger to view conditions outside the vehicle. Furthermore, in recent years, for the purpose of improving vehicle safety, vehicles with functions for automatically avoiding collisions with other vehicles traveling ahead or pedestrians have been developed. Such a vehicle includes, for example, a device such as a camera installed in the vehicle and transmits and receives information such as road conditions through the glass (e.g., the windshield or the like) of the vehicle.

[0003] However, in some cases, due to backlighting from sunlight or headlights of oncoming vehicles, it becomes difficult to obtain information from outside the vehicle through the transparent area. Accordingly, due to backlighting from sunlight or headlights of oncoming vehicles, in some cases, it becomes difficult for the device such as a camera to obtain information from outside the vehicle. Therefore, a technique has been proposed that uses a liquid crystal panel that can change the light transmittance for each of a plurality of divided areas, that is, can control light.In this technique, anti-glare performance is achieved by averaging the amount of incident light generated between the areas in a backlight or the like by a light controller, so that the brightness of the entire image of the device such as a camera is equalized (see, for example, Patent Document 1).

[0004] Furthermore, in the prior art, an electrochromic device developed for modulating light transmitted or reflected by furnishings such as windows, vehicle windows, or rearview mirrors (see, for example, Patent Document 2), a coated electrically heated window with an imaging device that images an object to be imaged through a viewing area of ​​the window (see, for example, Patent Document 3), and a composite window of a vehicle having a functional element (see, for example, Patent Document 4) are known. [Prior art documents][Patent documents] Patent document 1: JP H09 - 214 827 A Patent document 2: US 5,353,148 A Patent document 3: EP 1 605 729 A2 Patent document 4: DE 20 2018 102 520 U1 [Summary of the invention][Problem to be solved by the invention]

[0005] However, when a light control element is applied to the glass of a vehicle, the response speed of the light control element decreases at a low temperature (for example, at about -20 °C); therefore, any required anti-glare performance cannot be achieved at the low temperature.

[0006] The present invention has been made in view of the above points and has an object to improve the response speed of a light control element in a glass having the light control element at a low temperature. [Means of solving the problems]

[0007] The present glass is a glass for a vehicle and includes a glass panel; a transparent region defined in the glass; and a light control element disposed in at least a portion of a region of the glass panel that overlaps the transparent region in plan view, and configured to switch the light transmission. The light control element includes a light control layer; a pair of conductive thin films surrounding the light control layer, wherein at least one of the pair of conductive thin films, disposed on a vehicle exterior, has a heat ray reflection function, and an energy reflectance of the transparent region is greater than or equal to 25%; a pair of light control bus bars configured to supply current to the pair of conductive thin films so that the light control layer is driven.and a pair of heating bus bars configured to heat at least one of the pair of conductive thin films; [Effects of the invention]

[0008] According to the present invention, the response speed of a light control element in a glass having the light control element can be improved at a low temperature. [Brief description of the drawings] Fig. 1 includes diagrams showing an example of a windshield for a vehicle according to a first embodiment; Fig. 2 includes diagrams showing an example of a light control element according to the first embodiment; Fig. 3 is a plan view showing an example of a light control element according to a modified example 1 of the first embodiment; Fig. 4 is a cross-sectional view showing an example of a light control element according to a modified example 2 of the first embodiment; Fig. 5 is a diagram showing a cross-sectional structure of a laminated glass according to a comparative example; and Fig. Figure 6 is a diagram showing conditions and results of examples and comparative examples. [Mode for carrying out the invention]

[0009] Embodiments for carrying out the present invention will be described below with reference to the drawings. In the drawings, the same elements are assigned the same reference numerals, and duplicate descriptions may be omitted. Furthermore, in some of the drawings, the size and shape may be partially exaggerated to facilitate understanding of the disclosure of the present invention.

[0010] It should be noted that although a windshield for a vehicle is used as an example for description here, the present invention is not limited thereto; a glass according to the embodiments can be applied to a glass other than a windshield for a vehicle. Furthermore, although an information transmission / reception area is used as the transparent area as an example for description, it is not limited as such; the transparent area refers to an area in the glass through which light is transmitted and circumstances outside the vehicle can be recognized. Furthermore, a vehicle is typically an automobile, but generally refers to a mobile body having a glass, including a railway vehicle, a watercraft, an aircraft, and the like.

[0011] Furthermore, "top view" refers to viewing a given area of ​​a windshield in the vertical direction of the given area, and "planar shape" refers to a shape of the given area of ​​the windshield viewed in the vertical direction of the given area. Furthermore, in this specification, top and bottom refer to the Z-axis direction of a drawing, and left and right refer to the Y-axis direction of a drawing.

[0012] Furthermore, the visible light transmittance in the present invention conforms to a value specified in JIS R3108:1998.

[0013] Furthermore, the energy reflection coefficient in the present invention corresponds to a value specified in JIS R3108:1998. <Erste Ausführungsform>

[0014] The Fig. 1 comprises diagrams showing, by way of example, a windshield for a vehicle according to a first embodiment, wherein the Fig. 1(a) is a diagram schematically showing how a windshield is visually perceived from the inside of the vehicle to the outside of the vehicle (the windshield 20 is in a state where it is attached to the vehicle upward in the Z direction); and Fig. 1(b) is a cross-sectional view of the windshield 20 shown in the Fig. 1(a), sectioned in the XZ direction and viewed in the Y direction. It should be noted that in the Fig. 1(b), although for convenience a device 300 is shown together with the windshield 20, the device 300 is not an element of the windshield 20.

[0015] As it is in the Fig. 1, the windshield 20 is a laminated glass for a vehicle, which includes a glass plate 21 as a glass plate on the vehicle inside; a glass plate 22 as a glass plate on the vehicle outside; an intermediate layer 23; a shading layer 24; and a light control member 25.

[0016] In the windshield 20, the glass plate 21 and the glass plate 22 are bonded together, with the intermediate layer 23 and the light control element 25 disposed therebetween. The intermediate layer 23 may be formed from a plurality of intermediate layers. The glass plate 21, the glass plate 22, and the intermediate layer 23 will be described in more detail later.

[0017] The shading layer 24 is provided at the edge of a surface 21a of the glass panel 21 on the vehicle interior. The shading layer 24 is an opaque layer and can be formed, for example, by applying a printing ink of a predetermined color to a glass surface. The shading layer 24 is, for example, an opaque, colored (e.g., black) ceramic layer. The presence of the opaque shading layer 24 at the edge of the windshield 20 can prevent degradation of members, including an adhesive member such as a urethane for holding the edge portion of the windshield 20 to be attached to the vehicle body, an adhesive member for attaching a bracket that attaches the device 300 to the windshield 20, and the like, due to ultraviolet light.

[0018] It should be noted that in the Fig. 1(b), although the shading layer 24 is provided on the surface 21a of the glass panel 21 on the vehicle interior side, this is not limited as such. For example, the shading layer 24 may be provided on one surface of the glass panel 22 on the vehicle interior side, or may be provided on both the surface 21a of the glass panel 21 on the vehicle interior side and the surface of the glass panel 22 on the vehicle interior side.

[0019] The windshield 20 has a defined test area A, which is specified in JIS Standard R3212. Furthermore, the windshield 20 has a transparent area, here a defined information transmission / reception area 26. The test area A is positioned within an area surrounded by the shading layer 24 in plan view, and the information transmission / reception area 26 is positioned within an opening provided in the shading layer 24.

[0020] The information transmission / reception area 26 functions as an area through which the device 300 transmits and / or receives information when the device 300 is mounted on the upper edge portion or the like of the windshield 20 in the vehicle. The planar shape of the information transmission / reception area 26 is not particularly limited and may be, for example, an isosceles trapezoid. It is preferable that the information transmission / reception area 26 does not obstruct the driver's field of vision when the windshield 20 is mounted on the vehicle, and at the same time, it is positioned above the test area A, as this is advantageous in terms of information transmission and / or reception.

[0021] It should be noted that device 300 is a device for transmitting and / or receiving information, such as a camera that receives visible light and infrared light, a millimeter-wave radar, an infrared laser, or the like, and is typically a camera. In the vehicle, in addition to device 300, another device for transmitting and / or receiving information may be arranged through information transmission / reception section 26. Here, a "signal" refers to an electromagnetic wave, including millimeter waves and light, such as visible light, infrared light, and the like, and is typically visible light.

[0022] The light control element 25 is an element that is arranged over at least a portion of an area outside the test area A and overlaps the information transmission / reception area 26 between the glass plate 21 and the glass plate 22 in plan view, and can switch the light transmission of the information transmission / reception area 26. The light control element 25 can be arranged within the test area A between the glass plate 21 and the glass plate 22 in plan view as required.

[0023] Although it is advantageous for the planar shape of the light control element 25 to be, for example, a rectangular shape slightly larger than the planar shape of the information transmission / reception area 26, it may be a trapezoidal shape, a rectangular shape, a trapezoidal shape with one or more curved sides, or any other shape. The planar shape of the light control element 25 may be smaller than the planar shape of the information transmission / reception area 26.

[0024] The Fig. Fig. 2 includes diagrams showing an example of a light control element according to the first embodiment, wherein the Fig. 2(a) is a plan view schematically showing how the environment of the information transmission / reception area is visually perceived from the inside of the vehicle to the outside of the vehicle; and Fig. 2(b) is a cross-sectional view taken along a line AA in the Fig. 2(a). It should be noted that in the Fig. 2(a) an illustration of the glass plates 21 and 22, the intermediate layer 23 and the shading layer 24 is omitted. Furthermore, in the Fig. 2(a) the information transmission / reception area 26 is indicated by dashed lines for convenience.

[0025] The light control element 25 is enclosed in the intermediate layer 23 and includes a base material 251, a conductive thin film 252, a light control layer 253, a conductive thin film 254, a base material 255, heating busbar 256, and light control busbar 257.

[0026] For example, a transparent resin or glass can be used as the base materials 251 and 255. Although the thickness of the base materials 251 and 255 can be set to be greater than or equal to 5 µm and less than or equal to 500 µm, it is preferably greater than or equal to 10 µm and less than or equal to 200 µm, and more preferably greater than or equal to 50 µm and less than or equal to 150 µm.

[0027] Plastic films serving as the base materials 251 and 255 can be formed from a homopolymer or a copolymer of at least one monomer, for example, selected from a group including polyester (e.g., polyethylene terephthalate, polyethylene naphthalate, and the like), polyamide, polyether, polysulfone, polyethersulfone, polycarbonate, polyallylate, polyetherimide, polyetheretherketone, polyimide, aramid, polybutylene terephthalate, polyvinyl butyral, and polyethylvinyl acetate. As glass materials constituting the base materials 251 and 255, for example, soda-lime glass, inorganic glass such as aluminosilicate, and organic glass, and the like can be mentioned.

[0028] The conductive thin film 252 is formed on a surface of the base material 251 on the glass plate 21 side and contacts a surface of the light control layer 253 on the glass plate 22 side. The conductive thin film 254 is formed on a surface of the base material 255 on the glass plate 22 side and contacts a surface of the light control layer 253 on the glass plate 21 side. In other words, the conductive thin films 252 and 254 are a pair of conductive thin films surrounding the light control layer 253.

[0029] For example, a transparent conductive oxide (TCO) can be used as the conductive thin films 252 and 254. Examples of TCO include, but are not limited to, tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), indium-doped cadmium oxide, and the like.

[0030] A transparent conductive polymer such as poly(3,4-ethylenedioxythiophene) (PEDOT) or poly(4,4-dioctylcyclopentadithiophene) may also be suitably used as the conductive thin films 252 and 254. Furthermore, a laminated film of a metal layer and a dielectric layer, a silver nanowire, a metal mesh made of silver or copper, or the like may also be suitably used as the conductive thin films 252 and 254.

[0031] The conductive thin films 252 and 254 can be formed, for example, by sputtering, vacuum vapor deposition, or physical vapor deposition (PVD) such as ion plating. The conductive thin films 252 and 254 can be formed by chemical vapor deposition (CVD) or wet coating.

[0032] Furthermore, when applying the light control element 25 to the windshield 20, it is necessary to prevent the light control element 25 from becoming hot and degrading due to heat rays from the sun. To achieve this, for example, the light control element 25 can be used in conjunction with a heat-ray reflecting glass or a heat-ray reflecting film. In this case, it is advantageous to use a heat-ray reflecting film whose cost is relatively low, since applying a heat-ray reflecting glass only to the surroundings of the information transmission / reception area 26 results in high costs. However, when a heat-ray reflecting film is used, the addition of the heat-ray reflecting film reduces the transmittance of the windshield 20 and / or changes the color of the windshield 20 and may thereby impair the detection capability of the device 300.

[0033] In the windshield 20, the conductive thin film 252 and / or the conductive thin film 254 provided for supplying current to the light control layer 253 may be provided with a function of a heat-ray reflecting layer, instead of providing a heat-ray reflecting layer separately from the light control element 25. In this case, compared with the case of providing a heat-ray reflecting layer separately from the light control element 25, the influence of the sensing performance of the device 300 can be reduced. In other words, the change in the light control element 25 due to heat rays can be suppressed while maintaining the sensing performance of the device 300.In particular, compared with the case of providing a heat ray reflecting layer separately from the light control member 25, a reduction in visible light transmittance and a change in color of a portion of the windshield 20 with the light control member 25 enclosed in the light transmitting mode can be suppressed.

[0034] The color change is defined as the difference between the maximum and minimum transmittance values ​​at specified wavelengths (436 nm, 546 nm, and 700 nm), and is determined to be within an acceptable range if the difference between the maximum and minimum transmittance values ​​at the specified wavelengths (436 nm, 546 nm, and 700 nm) is less than or equal to 12%. It should be noted that the specified wavelengths (436 nm, 546 nm, and 700 nm) are wavelengths corresponding to blue, green, and red in the RGB colorimetric system according to the CIE (International Commission on Illumination), and that a difference in transmittance at the three wavelengths of more than 12% adversely affects the detection capability of the device 300.

[0035] It should be noted that in order to prevent the light control element 25 from becoming hot and degrading, the conductive thin film 252 and / or the conductive thin film 254 may be provided with the function of a heat-ray reflecting layer. According to the present invention, at least the conductive thin film 252 disposed on the vehicle exterior has the function of heat-ray reflection. This can effectively prevent the light control element 25 from becoming hot due to heat rays and prevent the risk of the light control element 25 being degraded. Furthermore, according to the present invention, the energy reflectance of the information transmission / reception section 26 is greater than or equal to 25%. This can effectively prevent the light control element 25 from becoming hot due to heat rays and prevent the risk of the light control element 25 being degraded.

[0036] In the case where the conductive thin film 252 and / or the conductive thin film 254 is or are provided with the function of a heat ray reflecting layer, one of the materials exemplified above may be used as the material of the conductive thin film 252 and / or the conductive thin film 254.

[0037] However, it is preferable to use, as the conductive thin film 252 and / or the conductive thin film 254, a laminated film comprising n layers (where n is an integer greater than or equal to 2) of functional layers containing a material that reflects infrared rays, and n+1 layers of dielectric layers laminated to surround the functional layers. By using a laminated film as the conductive thin film 252 and / or the conductive thin film 254, the energy reflectance of the information transmission / reception area 26 can be increased to be greater than or equal to 25%, and the effect of suppressing degradation of the light control element 25 can be enhanced.

[0038] For example, a laminated film comprising two layers of functional layers containing silver as a material for reflecting infrared rays and three layers of dielectric layers laminated to surround the functional layers; or a laminated film comprising three layers of functional layers containing silver and four layers of dielectric layers laminated to surround the functional layers may be used.

[0039] In the case of using silver as the material for reflecting infrared rays, functional layers containing silver may be formed of silver alone, or they may be formed as a metal layer or alloy layer containing silver as the main component. In the case of using silver as the main component, metal elements other than silver, such as Pd, Au, Cu, Pt, and the like, may be included. The film thickness of the functional layer or the dielectric layer can be appropriately determined depending on the total number of layers and the constituent materials of each layer, and may be set, for example, within a range of several nm to several hundred nm.

[0040] The light control layer 253 is disposed between the conductive thin film 252 and the conductive thin film 254. For the light control layer 253, for example, a suspended particle array (SPD) film can be used. A generic SPD film formed to include a polymer layer containing suspended particles that can be oriented by applying a voltage, sandwiched between two layers of electrically insulating films with transparent conductive films applied to the inner surfaces, can be used. In such an SPD film, by applying a voltage between the transparent conductive films by turning on the power switch, suspended particles in the polymer layer are oriented, and the SPD film enters a state where it has high visible light transmittance and high transparency.In a state where the power switch is off, the suspended particles in the polymer layer are not oriented, and the SPD film is in a state where it has low visible light transmittance and low transparency.

[0041] It should be noted that polymer-dispersed liquid crystals (PDLCs) can be used as the light-controlling layer 253 instead of using the SPD film. PDLCs can be prepared by mixing a prepolymer, nematic liquid crystals, and a spacer material in a specific ratio, and can then be sandwiched between two soft, transparent conductive films. The operating principles include the following: When no electric field is applied, liquid crystal droplets can be randomly distributed in the polymer material in a state where the orientators are freely oriented.In such a case, the refractive index of the liquid crystal with respect to normal light does not match that of the polymer material, causing a relatively strong light scattering effect. As a result, the PDLC film has a milky-white appearance, which is either translucent or opaque. In an electric field, the orientators of the liquid crystal droplets can be aligned along the direction of the external electric field due to the positive dielectric anisotropy. In the case where the refractive index of the liquid crystal with respect to normal light matches that of the polymer material, light can pass through the PDLC film, and thus the PDLC film has a transparent appearance. In particular, a higher voltage applied to the PDLC film makes the PDLC film more transparent.

[0042] Further, as the light control layer 253, polymer network liquid crystals (PNLC); guest-host liquid crystals; TN liquid crystals; VA liquid crystals; a photochromic, electrochromic, or electrokinetic material, or the like can be used.

[0043] Furthermore, it is more preferable to use, as the light control layer 253, a material in which the oriented particles are perpendicular to the transparent conductive film when no voltage is applied. Such a light control layer can transmit light when no electric field is applied, and once a voltage is applied, the oriented particles settle, so that light is absorbed or scattered. Such a light control mode is called a reverse mode and can be implemented with a liquid crystal material having negative dielectric anisotropy.

[0044] In the case of disposing the light control element 25 in a transparent portion of a window of a vehicle, it is more preferable to apply the light control element 25 with a reversing mode in view of the risk of separation failure caused by an impact of an accident.

[0045] The pair of heater bus bars 256 extend in the Z direction along both ends in the Y direction of a surface of the conductive thin film 252 on the glass plate 21 side and are arranged to face each other with the light control layer 253 interposed therebetween. The pair of heater bus bars 256 are electrically connected to the conductive thin film 252, so that the conductive thin film 252 is heated.

[0046] One electrode of the pair of heater bus bars 256 is, for example, a positive electrode and is connected to the positive side of a power supply, such as a battery, installed in the vehicle, by means of a lead wire or the like. Furthermore, the other electrode of the pair of heater bus bars 256 is, for example, a negative electrode and is connected to the negative side of a power supply, such as a battery, installed in the vehicle, by means of a lead wire or the like.

[0047] When power is supplied from the power source, such as a battery, to the conductive thin film 252 via the pair of heater bus bars 256, the conductive thin film 252 generates heat. The heat generated in the conductive thin film 252 heats the light control layer 253; therefore, a reduction in the response speed of the light control element 25 at a low temperature (e.g., a temperature outside the vehicle around -20°C) can be prevented, and the required anti-glare performance can be achieved even at the low temperature.

[0048] Furthermore, the heat generated in the conductive thin film 252 heats the information transmitting / receiving area 26 of the windshield 20, removes frost and fog on the surfaces of the glass plates 21 and 22 constituting the information transmitting / receiving area 26, and thereby good detection by the device 300 can be ensured.

[0049] It is preferable that the amount of heat generated in the conductive thin film 252 heated by the heater busbars 256 is greater than or equal to 600 W / m 2 Furthermore, it is preferably greater than or equal to 800 W / m 2 and more preferably greater than or equal to 1000 W / m 2 This can effectively prevent a reduction in the response speed of the light control element 25 at low temperatures; improve the ability to remove frost and fog on the surfaces of the glass plates 21 and 22 constituting the information transmission / reception area 26; and ensure even better detection of the device 300.

[0050] Furthermore, heat generation in the conductive thin film 252 can be effectively controlled by detecting the outside air temperature. For example, when the outside air temperature is higher than 5°C, the reduction in the response speed of the light control element 25 is small; therefore, the conductive thin film 252 can be controlled so that it is not heated normally, and when the outside air temperature drops below 5°C, it is heated, thus preventing a reduction in the response speed of the light control element 25. Consequently, unnecessary power consumption during high outside air temperatures can be curbed, and when the outside temperature is high, the intermediate layer 23 and the light control element 25 can be prevented from becoming excessively hot and degrading due to heat generated in the conductive thin film 252.

[0051] It should be noted that the pair of heater bus bars 256 may be electrically connected to the conductive thin film 254 instead of the conductive thin film 252. In this case, the conductive thin film 254 may be heated. Further, the pair of heater bus bars 256 may be electrically connected to the conductive thin film 252, and another pair of heater bus bars may be electrically connected to the conductive thin film 254. In this case, the conductive thin films 252 and 254 may be heated, thereby increasing the overall heat generation.

[0052] Although this is not reflected in the cross-section in the Fig. As can be seen in Figure 2(b), the pair of light control bus bars 257 extend in the Y direction along one end in the Z direction of the surface of the conductive thin film 252 on the glass plate 21 side. One of the pair of light control bus bars 257 is electrically connected to the conductive thin film 252, the other is electrically connected to the conductive thin film 254, and the conductive thin films 252 and 254 are supplied with current, so that the light control layer 253 is operated. The pair of light control bus bars 257 is independent of the pair of heater bus bars 256.

[0053] One electrode of the pair of light control bus bars 257 is, for example, a positive electrode and is connected to the positive electrode of the power supply, such as a battery, installed in the vehicle, by means of a lead wire or the like. Furthermore, the other electrode of the pair of light control bus bars 257 is, for example, a negative electrode and is connected to the negative electrode of the power supply, such as a battery, installed in the vehicle, by means of a lead wire or the like.

[0054] When a voltage is supplied to the light control layer 253 from the power source such as a battery via the pair of light control bus bars 257, the transmittance of the light control layer 253 is switched depending on the voltage.

[0055] A silver paste is preferably used for the heater bus 256 and the light control bus 257. The silver paste can be applied, for example, by a printing method such as screen printing. The heater bus 256 and the light control bus 257 can be formed by sputtering or the like from at least one metal selected from a group comprising silver, copper, tin, gold, aluminum, iron, tungsten, and chromium; an alloy containing two or more metals selected from this group; or a conductive organic polymer. Further, copper tapes, flat braided copper cables, or copper adhesive tapes containing a conductive adhesive can be used for the heater bus 256 and the light control bus 257.

[0056] The light control element 25 has a light transmission mode (a mode with high visible light transmittance) and a light absorption mode (a mode with low visible light transmittance). Although the maximum visible light transmittance of the information transmission / reception area 26 including the light control element 25 is within an acceptable range in the light transmission mode if it is greater than or equal to 40%, it is preferably greater than or equal to 50%. By setting the maximum visible light transmittance of the information transmission / reception area 26 including the light control element 25 in the light transmission mode to greater than or equal to 50%, good detection by the device 300 can be sufficiently ensured.It should be noted that the maximum visible light transmittance represents a visible light transmittance in a state where the voltage applied to the light control layer 253 is adjusted so that the visible light transmittance becomes maximum.

[0057] For example, in the case where the light control element 25 operates in the light transmission mode while being supplied with power, it is preferable to cause the maximum visible light transmittance to become greater than or equal to 50%. In this case, while being supplied with power, it is more preferable to cause the maximum visible light transmittance to become greater than or equal to 60%, and more preferable to cause the maximum visible light transmittance to become greater than or equal to 70%. Further, in the case where the light control element 25 operates in the light absorption mode while not being supplied with power, it is preferable to cause the maximum visible light transmittance to become less than 20%. Further, it is also preferable that the visible light transmittance be greater than or equal to 5%.This is because less than 5% makes it difficult to detect conditions outside the vehicle.

[0058] The light control element 25 can operate in the light transmission mode while not being supplied with power. In this case, it is only necessary to reverse the power supply / no power supply control. Further, in this case, it is preferable to cause the maximum visible light transmittance to be greater than or equal to 50%, more preferable to cause it to be greater than or equal to 60%, and even more preferable to cause it to be greater than or equal to 70%; and it is preferable to cause the minimum visible light transmittance in the light absorption mode to be greater than or equal to 5%.

[0059] By incorporating the light control element 25 into the windshield 20, the amount of light transmitted through the information transmission / reception area 26 can be adjusted depending on the amount of light incident on the information transmission / reception area 26 from outside the vehicle. For example, in the case where the amount of incident light is excessive due to direct sunlight or the headlights of an oncoming vehicle, by reducing the visible light transmittance, the amount of light transmitted through the information transmission / reception area 26 can be reduced, so that an appropriate amount of light is incident on the device 300.Further, in the case where the amount of light incident on the information transmitting region is not excessive, by changing the visible light transmittance in a low-transmitting region to a high value, the information transmitting / receiving region 26 can be adjusted to transmit a sufficient amount of light, thereby making an appropriate amount of light incident on the device.

[0060] It is preferable that the windshield 20 include a control device for measuring the amount of light incident on the information transmission / reception area 26 from outside the vehicle, so that the power supply and power removal of the light control element 25 are controlled depending on the amount of light. For example, in the case of using a light control element with high visible light transmittance while being supplied with power as the light control element 25, by using such a control device, a state in which the power is on can be maintained when the amount of incident light is not excessive, and the power can be turned off when the amount of incident light is excessive due to backlighting or the like.Consequently, the amount of light passing through the information transmission / reception area 26 can always be optimized so that an appropriate amount of light is incident on the device 300. In the case of using the light control element 25 with high visible light transmittance while not being supplied with power, the same effect can be expected by reversing the power supply / no power supply control.

[0061] The glass plate 21, the glass plate 22 and the intermediate layer 23 are described in detail.

[0062] In the windshield 20, the surface 21a of the glass plate 21 on the vehicle inside (the inner surface of the windshield 20) and a surface 22a of the glass plate 22 on the vehicle outside (the outer surface of the windshield 20) may be flat surfaces or curved surfaces.

[0063] For example, soda-lime glass, an inorganic glass such as aluminosilicate, an organic glass, or the like can be used as glass plates 21 and 22. In the case where the glass plates 21 and 22 are inorganic glass, they can be manufactured, for example, by a float process.

[0064] It is preferable that the plate thickness of the glass plate 22 positioned on the outer side of the windshield 20 be greater than or equal to 1.8 mm and less than or equal to 3 mm at the thinnest portion. When the plate thickness of the glass plate 22 is greater than or equal to 1.8 mm, the strength is sufficient in terms of resistance to impact from stones or the like; and when the thickness is less than or equal to 3 mm, the mass of the laminated glass is not excessive, and this is preferable in terms of fuel efficiency of the vehicle. The plate thickness of the glass plate 22 at the thinnest portion is preferably greater than or equal to 1.8 mm and less than or equal to 2.8 mm, and more preferably greater than or equal to 1.8 mm and less than or equal to 2.6 mm.

[0065] It is preferable that the thickness of the glass plate 21 positioned on the inside of the windshield 20 be greater than or equal to 0.3 mm and less than or equal to 2.3 mm. A thickness of the glass plate 21 greater than or equal to 0.3 mm improves handling, and a thickness less than or equal to 2.3 mm prevents the mass of the windshield 20 from becoming excessive. It should be noted that the glass plate 21 and the glass plate 22 may have a wedge-shaped cross-section.

[0066] The thickness of the glass plates 21 and 22 need not be constant at all locations and may vary from location to location if necessary. For example, one or both of the glass plates 21 and 22 may be provided with a wedge-shaped cross-sectional area in which the thickness of the upper end is greater in the vertical direction than that of the lower end when the windshield 20 is mounted on the vehicle.

[0067] In the case where the windshield 20 has a curved shape, after the glass panels 21 and 22 are formed by a float process or the like, bending is performed before bonding to the intermediate layer 23. Bending is performed by heating and softening the glass. The heating temperature of the glass during bending is approximately 550°C to 700°C.

[0068] As the intermediate layer 23 that bonds the glass plate 21 and the glass plate 22, a thermoplastic resin is often used. Examples of such thermoplastic resins include a plasticized polyvinyl acetal resin, a plasticized polyvinyl chloride resin, a saturated polyester resin, a plasticized saturated polyester resin, a polyurethane resin, a plasticized polyurethane resin, an ethylene-vinyl acetate copolymer resin, an ethylene-ethyl acrylate copolymer resin, and the like, as those conventionally used in this type of application. Furthermore, a resin composition containing a modified block copolymer hydride described in JP 6 065 221 B2 may also be suitably used.

[0069] Of these, a plasticized polyvinyl acetal resin is advantageously used because it has an excellent balance of properties, including transparency, weather resistance, strength, adhesion, penetration tolerance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. One of these thermoplastic resins can be used alone, or two or more types can be used in combination. It should be noted that "plasticized" in the above "plasticized polyvinyl acetal resin" means that it has been plasticized by adding a plasticizer. The same applies to the other plasticized resins.

[0070] As the polyvinyl acetal resin described above, there may be mentioned a polyvinyl formal resin obtained by reacting a polyvinyl alcohol (hereinafter, may be referred to as "PVA") with formaldehyde; a polyvinyl acetal resin in a narrow sense obtained by reacting PVA with acetaldehyde; and a polyvinyl butyral resin (hereinafter, may be referred to as "PVB") obtained by reacting PVA with n-butyraldehyde; and the like. In particular, PVB is recommended as suitable because it has an excellent balance of properties, including transparency, weather resistance, strength, adhesion strength, penetration tolerance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. It should be noted that one of these polyvinyl acetal resins can be used alone, or two or more types can be used in combination.However, the material constituting the intermediate layer 23 is not limited to a thermoplastic resin. Furthermore, the intermediate layer 23 may contain functional particles such as infrared absorbers, ultraviolet absorbers, luminescent agents, and the like.

[0071] It is preferable that the film thickness of the intermediate layer 23 at the thinnest portion be greater than or equal to 0.5 mm. A film thickness of the intermediate layer 23 greater than or equal to 0.5 mm provides sufficient penetration resistance required as a windshield. Further, it is preferable that the film thickness of the intermediate layer 23 at the thickest portion be greater than or equal to 3 mm. When the maximum value of the film thickness of the intermediate layer 23 is less than or equal to 3 mm, the mass of the laminated glass is not too large. The maximum value of the intermediate layer 23 is more preferably less than or equal to 2.8 mm, and even more preferably less than or equal to 2.6 mm. Further, the intermediate layer 23 may have a wedge shape in cross section.

[0072] It should be noted that the intermediate layer 23 may have three or more layers. For example, by forming the intermediate layer to have three layers and adjusting the hardness of the middle layer to a lower value than the hardness of the layers on both sides by adding a plasticizer or the like, the sound insulation performance of the laminated glass can be improved. In this case, the hardness of the layers on both sides may be identical or may be different.

[0073] To produce the intermediate layer 23, for example, the resin materials described above are appropriately selected and extruded in a heated and molten state using an extruder for molding. The extrusion conditions, such as the extrusion speed of the extruder, are uniformly adjusted. Thereafter, to form curves on the top and bottom surfaces according to the design of the windshield 20, for example, the resin film formed by the extrusion is stretched if necessary, and the intermediate layer 23 is completed.

[0074] To produce laminated glass, the interlayer 23 and the light-control element 25 are sandwiched between the glass plate 21 and the glass plate 22 to form a laminate. Then, the laminate is placed in a rubber bag, for example, and bonded in a vacuum of -65 to -100 kPa at a temperature of approximately 70 to 110°C. The heating conditions, temperature conditions, and lamination method are appropriately selected, taking into account the properties of the light-control element, for example, so that it does not degrade during the lamination process.

[0075] Furthermore, by applying a bonding treatment of heating and pressing to the laminate under conditions of, for example, 100 to 150 °C and a pressure of 0.6 to 1.3 MPa, laminated glass with even better durability can be obtained. However, in some cases, this heating and pressing process is not used, taking into account the simplification of the process and the properties of the materials incorporated into the laminated glass.

[0076] Between the glass plate 21 and the glass plate 22, in addition to the intermediate layer 23 and the light control member 25, a sheet or film and / or device having functions of light emission, visible light reflection, scattering, decoration, absorption, and the like may be provided to an extent that does not impair the effects of the present invention. Such a sheet or film and device having the above-mentioned functions can be formed directly on the main surfaces of the glass plate 21 and the glass plate 22.

[0077] As described, the windshield 20 includes the light control element 25; and the light control element 25 includes the light control layer 253, the conductive thin films 252 and 254 surrounding the light control layer 253, the light control bus bars 257 for supplying current to the conductive thin films 252 and 254 to drive the light control layer 253, and the heater bus bars 256 of the conductive thin film 252.

[0078] Consequently, the conductive thin film 252 can be heated by the heater bus 256; therefore, even when the temperature outside the vehicle decreases, the temperature of the light control layer 253 can be maintained higher than the temperature outside the vehicle. As a result, even when the temperature outside the vehicle decreases, a reduction in the response speed of the light control element 25 can be prevented, and the anti-glare performance that is present on demand can be maintained.

[0079] Furthermore, in the windshield 20, it is preferable that the conductive thin film 252 and / or the conductive thin film 254 be provided with the function of a heat-ray reflecting layer, and according to the present invention, at least the conductive thin film 252 disposed on the vehicle exterior has the function of heat-ray reflection. Therefore, even if a heat-ray reflecting layer is not provided separately from the light control element 25, the risk of the light control element 25 becoming hot due to heat rays can be reduced while maintaining the sensing capability of the device 300, and the risk of degradation of the light control element 25 can be prevented.Further, in this case, compared with the case of providing a heat ray reflecting layer separately from the light control member 25, a reduction in visible light transmittance and a change in color of a portion of the windshield 20 having the enclosed light control member 25 in the light transmission mode can be suppressed. <Modifiziertes Beispiel 1 der ersten Ausführungsform>

[0080] In a modified example 1 of the first embodiment, an example is shown in which one of the heater busbars also serves as a light control busbar. Note that in the modified example 1 of the first embodiment, descriptions of the same components as in the above-described embodiment may be omitted.

[0081] The Fig. Fig. 3 is a plan view showing an example of a light control element according to the modified example 1 of the first embodiment, and schematically showing how the environment of the information transmission / reception area is visually perceived from the inside of the vehicle to the outside of the vehicle. It should be noted that the cross-sectional structure of the light control element according to the modified example 1 of the first embodiment is similar to that in Fig. Fig. 2(b) is essentially identical, and thus the illustration is omitted.

[0082] As it is in the Fig. 3, in a windshield 20A of Modified Example 1 of the first embodiment, a light control element 25A has only a light control busbar 257 electrically connected to a conductive thin film 254. Otherwise, the light control element 25A is substantially identical to the light control element 25.

[0083] The heater bus bars 256 are electrically connected to the conductive thin film 252; therefore, when a voltage is applied between one of the heater bus bars 256 and the light control bus bar 257, the transmittance of the light control layer 253 can be switched depending on the voltage. In other words, in the light control element 25A, one of the heater bus bars 256 also serves as the light control bus bar 257.

[0084] In this way, by having one of the heater bus bars 256 serve as the light control bus bar 257, the structure of the light control element 25A can be simplified compared with the structure of the light control element 25. <Modifiziertes Beispiel 2 der ersten Ausführungsform>

[0085] In Modified Example 2 of the first embodiment, an example is shown in which a windshield is not laminated glass. Although the present example is preferred as a side glass or rear glass, it will be described in this specification as an example of a windshield. Note that in Modified Example 2 of the first embodiment, description of the same components as in the above-described embodiment may be omitted.

[0086] The Fig. Fig. 4 is a cross-sectional view showing an example of a light control element according to the modified example 2 of the first embodiment, and showing a cross section showing Fig. 2(b). It should be noted that in the modified example 2 of the first embodiment, the plan view schematically showing how the environment of the information transmission / reception area is visually perceived from the inside of the vehicle to the outside of the vehicle is the same as that in the Fig. 2(a) is essentially identical; therefore, the illustration is omitted.

[0087] As it is in the Fig. As shown in Figure 4, the windshield 20B is a glass (not laminated glass) for a vehicle, including a glass panel 22, a light control element 25, and an adhesive layer 27. The light control element 25 is adhered to a surface 22b of the glass panel 22 on the vehicle interior side by the adhesive layer 27.

[0088] The material of the adhesive layer 27 is not particularly limited as long as it has the function of adhering the light control element 25. For example, acrylic-based, acrylate-based, urethane-based, urethane acrylate-based, epoxy-based, epoxy acrylate-based, polyolefin-based, modified olefin-based, polypropylene-based, ethylene-vinyl alcohol-based, vinyl chloride-based, chloroprene rubber-based, cyanoacrylate-based, polyamide-based, polyimide-based, polystyrene-based, and polyvinyl butyral-based materials can be mentioned. The material of the adhesive layer 27 is transparent to visible light. The thickness of the adhesive layer 27 can be set, for example, to greater than or equal to 0.2 μm and less than or equal to 70 μm.

[0089] In this way, even in the case where the windshield 20B is not laminated glass, the light control element 25, which includes the heating busbars 256 for heating the conductive thin film 252 in addition to the light control busbar 257 for driving the light control layer 253, provides substantially the same effects as in the first embodiment. Furthermore, by providing the conductive thin film 252 and / or the conductive thin film 254 with the function of a heat ray reflecting layer, substantially the same effects as in the first embodiment can be obtained. <Beispiele und Vergleichsbeispiele>

[0090] The following examples and comparative examples serve to illustrate the present invention, with Examples 2 and 3 being examples of the invention. However, the present invention is not limited thereto. [Example 1]

[0091] In Example 1, a laminated glass with a light control element 25 was produced as described in Fig. 2. Specifically, a clear glass with a plate thickness of 2 mm was used as glass plates 21 and 22 and formed into flat plates measuring 150 mm × 150 mm. A PVB with a thickness of 0.38 mm was used as the interlayer 23.

[0092] An SPD-A as the light control element 25 had substantially the same structure as LCF-1103DHA (manufactured by Hitachi Chemical Co., Ltd., 30 μm thick). Specifically, the light control element 25 was fabricated by arranging a base material 251 on which a conductive thin film 252 was formed by sputtering ITO, and a base material 255 on which a conductive thin film 254 was formed by sputtering ITO, such that the conductive thin film 252 and the conductive thin film 254 enclose a light control layer 253.

[0093] The amount of heat generated in the conductive thin film 252 connected to the heater bus bars 256 was determined to be 800 W / m 2 Furthermore, the energy reflectance of a portion of the laminated glass including the light control element 25 in this structure was 6%. [Example 2]

[0094] In Example 2, Ag3 was used as the conductive thin film 252. Further, the amount of heat generated in the conductive thin film 252 connected to heater bus bars 256 was set to 1000 W / m 2set. Furthermore, the energy reflectance of a portion of the laminated glass including the light control element 25 in this structure was 35%. Apart from this, a laminated glass was manufactured in substantially the same manner as in Example 1. It should be noted that Ag3 is a laminated film in which three layers of functional layers containing silver and four layers of dielectric layers made of an oxide comprising zinc and tin as main components are alternately laminated by sputtering. [Example 3]

[0095] In Example 3, Ag2 was used as the conductive thin film 252. Further, the amount of heat generated in the conductive thin film 252 connected to heater bus bars 256 was set to 600 W / m 2set. Furthermore, the energy reflectance of a portion of the laminated glass including the light control element 25 in this structure was 25%. Apart from this, a laminated glass was manufactured in substantially the same manner as in Example 1. It should be noted that Ag2 is a laminated film in which two layers of functional layers containing silver and three layers of dielectric layers made of an oxide comprising zinc and tin as main components are alternately laminated by sputtering. [Example 4]

[0096] In Example 4, an SPD-B as the light control element 25 had substantially the same structure as LCF-1103DHA (manufactured by Hitachi Chemical Co., Ltd., 30 μm thick). Specifically, the light control element 25 was prepared by arranging a base material 251 on which a conductive thin film 252 was formed by sputtering ITO, and a base material 255 on which a conductive thin film 254 was formed by sputtering ITO, such that the conductive thin film 252 and the conductive thin film 254 enclose a light control layer 253. Apart from this, a laminated glass was prepared in substantially the same manner as in Example 1. [Comparison example 1]

[0097] In Comparative Example 1, no heating manifolds were provided. Apart from that, a laminated glass was prepared in substantially the same manner as in Example 1. [Comparison example 2]

[0098] In comparison example 2, as described in the Fig. As shown in FIG. 5, a heat-ray reflecting film 35 comprising Ag3 as a heat-ray reflecting layer 352 formed on a base material 351 was sandwiched in an intermediate layer 23 outwardly of the light-controlling element 25, thus producing a laminated glass. Furthermore, the energy reflectance of a portion of the laminated glass including the light-controlling element 25 in this structure was 35%. Apart from this, a laminated glass was produced in substantially the same manner as in Example 1. [Comparison example 3]

[0099] In Comparative Example 3, the amount of heat generated in the conductive thin film 252 connected to heater bus bars 256 was set to 500 W / m 2 Apart from that, a laminated glass was prepared in substantially the same manner as in Example 1. [Reviews]

[0100] First, a laminated glass was placed in a low-temperature environment of -20°C to evaluate the low-temperature response speed of the light-controlling element 25. The response speed is the time required to change the transmittance by 50% when switching from the light-absorption mode to the light-transmission mode, and 100 represents the difference in transmittance between the light-transmission mode and the light-absorption mode in the light-controlling element 25. It was rated as "good" if the response speed was less than 3 seconds; or "failed" if it was 3 seconds or longer.

[0101] Second, the degradation protection of the light-controlling element 25 was evaluated. Specifically, a test was conducted in which the portion of the laminated glass in which the light-controlling element 25 was enclosed was exposed to ultraviolet irradiation conditions of 180 W / m 2 (300 to 400 nm) and a blackbody temperature (BPT) of 63°C using a super xenon weatherometer for 3000 hours. After the test, the transmittance retention (the ratio of the transmittances in the light transmission mode before and after the test) of the light control element 25 in the light transmission mode was measured, and then the retention was evaluated as "excellent" if it was greater than or equal to 90%; "good" if it was greater than or equal to 80% and less than 90%; or "failed" if it was less than 80%.

[0102] Third, the visible light transmittance (Tv) in the light transmission mode of the light control element 25 was evaluated, and it was rated as "excellent" when the maximum visible light transmittance was greater than or equal to 60%; "good" when it was greater than or equal to 50% and less than 60%; "fair" when it was greater than or equal to 40% and less than 50%; or "failed" when it was less than 40%.

[0103] Fourth, the color change of the light control element 25 in the light transmission mode was evaluated. The color change is defined as the transmittance at specified wavelengths (436 nm, 546 nm, and 700 nm), and is rated as "pass" if the difference between the maximum and minimum transmittance values ​​at the specified wavelengths (436 nm, 546 nm, and 700 nm) is less than or equal to 12%, or "fail" if it is greater than 12%.

[0104] The conditions and results of the examples and comparative examples are in the Fig. 6. It should be noted that in any of the ratings, "failing" indicates an unfavorable condition. Furthermore, any of "adequate," "good," and "excellent" indicate an advantageous condition, with "good" being more favorable than "adequate" and "excellent" being more favorable than "good."

[0105] As it is in the Fig. 6, regarding the response speed at the low temperature (-20 °C) of the light control element 25, it is apparent that a decrease can be suppressed by providing the conductive thin film 252 with the heater busbars 256 and heating the conductive thin film 252 so that it has a heat quantity greater than or equal to 600 W / m 2 It should be noted that 600 W / m 2a sufficient amount of heat to remove fogging from the laminated glass and to remove frozen moisture that clings to a pane in winter.

[0106] In contrast, in Comparative Example 1, no heater bus bars were provided, and the conductive thin film 252 could not be heated; therefore, the response speed of the light control element 25 decreased at the low temperature (-20°C). Furthermore, in Comparative Example 3, although the heater bus bars were provided, the amount of heat generated in the conductive thin film 252 was less than 600 W / m 2 and was insufficient; therefore, the response speed of the light control element 25 decreased at the low temperature (-20 °C).

[0107] Regarding the degradation protection of the light control element 25, the transmittance retention in the light transmission mode of each light control element 25 was greater than or equal to 80% and was within an acceptable range. Among them, in the case of using Ag2 or Ag3 as the heat ray reflecting layer (where the energy reflectance of the portion of the laminated glass including the light control element 25 is greater than or equal to 25%), the degradation protection effect of the light control element 25 is particularly significant.

[0108] The maximum visible light transmittance in the light transmission mode of each light control element 25 was greater than or equal to 40% and within an acceptable range. Particularly, in the case where the conductive thin film 252 is Ag2, the performance in both preventing a decrease in response speed and protecting against degradation of the light control element 25 was excellent. Furthermore, the maximum visible light transmittance of the light control element 25 in the light transmission mode was ensured to be greater than or equal to 60%, and thus, this can be considered a preferable structure.

[0109] Regarding the change in color of the light control element 25 in the light transmission mode, for Examples 1 to 4 and Comparative Examples 1 and 3, it was within an allowable range. However, in Comparative Example 2, the difference in transmittance between the maximum value and the minimum value for the specified wavelengths (436 nm, 546 nm, and 700 nm) was greater than 12%; therefore, the detecting performance of the device 300 was adversely affected. In other words, in a structure in which a heat ray reflecting film is used separately from a light control element, as in Comparative Example 2, although the reduction in the response speed of the light control element 25 at the low temperature (-20 °C) could be improved, there was an adverse effect of deteriorating the detecting performance of the device 300. Therefore, the structure used in Fig. 5 is not preferred.

[0110] The preferred embodiments and the like have been described in detail above; it should be noted that the present invention is not limited to the above-described embodiments and the like. [Description of reference symbols] 20, 20A, 20B Windshield 21 glass plate 21a, 22a, 22b surface 22 glass plate 23 Intermediate layer 24 Shading layer 25, 25A light control element 26 Information transmission / reception area 27 Adhesive layer 251, 255 Base material 252, 254 Conductive thin film 253 Light control layer 256 heating manifold 257 Lighting control busbar

Claims

[1] Glass for a vehicle, comprising: a glass plate (22); a transparent area defined in the glass; and a light control element (25) which is arranged in at least a portion of an area of ​​the glass plate (22) which overlaps the transparent area in plan view and which is designed to switch the light transmission, wherein the light control element (25) a light control layer (253), a pair of conductive thin films (252, 254) surrounding the light control layer (253), wherein at least one of the pair of conductive thin films (252, 254) arranged on a vehicle outer side has a heat ray reflection function, and an energy reflectance of the transparent region is greater than or equal to 25%, a pair of light control bus bars (257) configured to supply current to the pair of conductive thin films (252, 254) so ​​as to operate the light control layer (253), and a pair of heater bus bars (256) configured to heat at least one of the pair of conductive thin films (252, 254). [2] Glass according to claim 1, wherein the transparent area is an information transmission / reception area (26) through which a device installed in the vehicle transmits and / or receives information. [3] Glass according to claim 1 or 2, wherein the light control element (25) has a light transmission mode and a light absorption mode, and wherein the maximum visible light transmittance of the transparent region comprising the light control element (25) in the light transmission mode is greater than or equal to 50%. [4] Glass according to claim 3, wherein the light control element (25) operates in the light transmission mode while not supplied with power. [5] The glass according to any one of claims 1 to 4, wherein of the pair of conductive thin films (252, 254), at least one conductive thin film (252) disposed on a vehicle exterior contains silver. [6] Glass according to one of claims 1 to 5, wherein of the pair of conductive thin films (252, 254), at least one conductive thin film (252) arranged on a vehicle outer side, n layers (where n is an integer greater than or equal to two) of functional layers containing a material that reflects infrared rays, and n + 1 layers of dielectric layers laminated to surround the functional layers. [7] Glass according to one of claims 1 to 6, wherein the pair of heating bus bars (256) are arranged to face each other. [8] Glass according to one of claims 1 to 7, wherein the pair of light control busbars (257) is independent of the pair of heating busbars (256). [9] Glass according to one of claims 1 to 7, wherein one of the pair of heating busbars (256) also serves as a light control busbar (257). [10] Glass according to one of claims 1 to 9, wherein the amount of heat generated in the conductive thin film heated by the pair of heating busbars (256) is greater than or equal to 600 W / m 2 is. [11] The glass according to any one of claims 1 to 10, wherein the light control element (25) is formed from one of TN liquid crystals, VA liquid crystals, guest-host liquid crystals, polymer-dispersed liquid crystals, polymer network liquid crystals, and a suspended particle arrangement. [12] The glass according to any one of claims 1 to 11, wherein the pair of light control bus bars (257) extends in a plan view in a direction perpendicular to an extending direction of the pair of heating bus bars (256), and the pair of light control bus bars (257) are arranged along the ends of the conductive thin film (252) of the pair of conductive thin films (252, 254), the ends being ends of the conductive thin film (252) in the extending direction of the pair of heating bus bars (256). [13] A laminated glass for a vehicle, comprising: the glass according to any one of claims 1 to 12; an intermediate layer (23); and a second glass plate (21), wherein the glass plate (22) and the second glass plate (21) are connected such that the intermediate layer (23) is arranged therebetween, and wherein the light control element (25) is enclosed in the intermediate layer (23).

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