Vehicle dimmable laminated glass

Abstract

To provide a vehicle dimmable laminated glass, in which the switching time of a dimmable layer is unlikely to increase even in a low-temperature environment.SOLUTION: A vehicle dimmable laminated glass 10 to be used for a vehicle comprises: a vehicle outer glass plate 13 disposed on the outer side of a vehicle; a vehicle inner glass plate 11 disposed on the inner side of the vehicle; a dimmable sheet 20 disposed between the vehicle outer glass plate 13 and the vehicle inner glass plate 11; a vehicle outer intermediate layer 17 provided between the vehicle outer glass plate 13 and the dimmable sheet 20; and a vehicle inner intermediate layer 15 provided between the vehicle inner glass plate 11 and the dimmable sheet 20. The dimmable sheet 20 includes: a dimmable layer 22 whose light transmittance can be adjusted by applying a voltage; and a pair of conductive layers 24 disposed to sandwich the dimmable layer 22, which apply a voltage to the dimmable layer 22 when electric power is supplied. The vehicle outer intermediate layer 17 has an infrared absorption function 18.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a light-adjusting laminated glass for vehicles.

Background Art

[0002] Conventionally, in the window glass of vehicles such as automobiles and railways, a vehicle light-adjusting laminated glass in which a light-adjusting sheet capable of changing the light transmittance by energization is enclosed in an interlayer film is known. The light-adjusting sheet is composed of a light-adjusting layer and a pair of conductive layers sandwiching the light-adjusting layer. Such a vehicle light-adjusting laminated glass ensures the privacy of passengers. For example, in the off state where no current is applied to the conductive layer, the light-adjusting layer scatters light and becomes opaque, and in the on state where current is applied to the conductive layer, the light-adjusting layer becomes transparent. As the light-adjusting layer, for example, a liquid crystal element is used (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a laminated glass for vehicles. The laminated glass for vehicles has an inner glass plate, an outer glass plate, an interlayer film located between the inner glass plate and the outer glass plate, and a light-adjusting element enclosed in the interlayer film. The light-adjusting element has a pair of base materials and a light-adjusting layer located between the pair of base materials. The interlayer film includes an inner side portion located on the inner side of the vehicle sandwiching the light-adjusting layer and an outer side portion located on the outer side of the vehicle sandwiching the light-adjusting layer. The laminated glass for vehicles disclosed in Patent Document 1 is configured to satisfy the relationship of Tout < Tin, where Tout is the light transmittance of the outer glass plate, the outer side portion of the interlayer film, and the base material disposed on the outer side sandwiching the light-adjusting layer, and Tin is the light transmittance of the inner glass plate, the inner side portion of the interlayer film, and the base material disposed on the inner side sandwiching the light-adjusting layer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, in a low-temperature environment of -10 degrees or lower, when the dimming layer switches from an energized state to a non-energized state or from a non-energized state to an energized state with respect to the energized state of the conductive layer, the switching time, which is the time for changing from a transparent state to an opaque state or from an opaque state to a transparent state, may increase, which poses a problem. The laminated glass for vehicles disclosed in Patent Document 1 does not disclose any countermeasures against this problem, and there is room for improvement.

[0006] Therefore, there is a need for a vehicle dimming laminated glass in which the switching time of the dimming layer is less likely to increase even in a low-temperature environment.

Means for Solving the Problems

[0007] One embodiment of the vehicle dimming laminated glass according to the present disclosure is a vehicle dimming laminated glass used in a vehicle, including an outer vehicle glass plate disposed on the outside of the vehicle, an inner vehicle glass plate disposed on the inside of the vehicle, a dimming sheet disposed between the outer vehicle glass plate and the inner vehicle glass plate, an outer vehicle intermediate layer provided between the outer vehicle glass plate and the dimming sheet, and an inner vehicle intermediate layer provided between the inner vehicle glass plate and the dimming sheet. The dimming sheet has a dimming layer capable of adjusting the light transmittance when a voltage is applied, and a pair of conductive layers disposed so as to sandwich the dimming layer and applying a voltage to the dimming layer when power is supplied. The outer vehicle intermediate layer has an infrared absorption function.

[0008] According to this embodiment, since the outer vehicle intermediate layer has an infrared absorption function, it is possible to suppress a part of the infrared rays of the sunlight irradiated from the outside of the vehicle to the vehicle dimming laminated glass from being emitted to the outside of the vehicle. As a result, the infrared rays are not emitted to the outside of the vehicle and remain inside the vehicle dimming laminated glass. Thereby, the heating of the dimming layer by the infrared rays is promoted, so that the temperature of the dimming layer is difficult to decrease, and the increase in the switching time for the dimming layer to change from a transparent state to an opaque state or from an opaque state to a transparent state is suppressed even in a low-temperature environment.

[0009] In one embodiment of the electrochromic laminated glass for vehicles according to the present disclosure, it is preferable that the electrochromic layer contains polymer-dispersed liquid crystal.

[0010] According to this embodiment, an electrochromic laminated glass for vehicles capable of easily switching between the transparent state and the opaque state of the electrochromic layer by switching between the non-powered state and the powered state of the conductive layer can be obtained.

[0011] In one embodiment of the electrochromic laminated glass for vehicles according to the present disclosure, it is preferable that the outer-layer intermediate layer has the infrared absorption function by an infrared absorber.

[0012] According to this embodiment, since the outer-layer intermediate layer has the infrared absorption function by an infrared absorber, an electrochromic laminated glass for vehicles with an increased switching time suppressed can be easily obtained by disposing an infrared absorber in the existing outer-layer intermediate layer.

[0013] In one embodiment of the electrochromic laminated glass for vehicles according to the present disclosure, it is preferable that the infrared absorber contains at least one of fine particles of indium tin oxide, antimony-doped tin oxide, and cesium-doped tungsten oxide.

[0014] According to this embodiment, since indium tin oxide, antimony-doped tin oxide, and cesium-doped tungsten oxide are colorless and transparent in the state of fine particles, the electrochromic laminated glass for vehicles is not colored by the infrared absorber. Moreover, since they are fine particles of indium tin oxide, antimony-doped tin oxide, and cesium-doped tungsten oxide, the surface area increases and infrared rays are effectively absorbed.

[0015] In one embodiment of the electrochromic laminated glass for vehicles according to the present disclosure, it is preferable that a Low-E film is disposed on the inner surface of the inner glass plate.

[0016] According to this embodiment, by disposing a Low-E film on the inner surface of the inner glass plate of the vehicle, at least a part of the infrared rays of sunlight is reflected by the Low-E film and returns to the dimming sheet, staying inside the vehicle's dimming laminated glass. Therefore, since the heating of the dimming layer by infrared rays is promoted, it is difficult for the temperature of the dimming layer to decrease, and it is possible to easily obtain a vehicle dimming laminated glass in which the switching time increase is suppressed. Further, since the infrared rays reaching the vehicle interior are reduced by the Low-E film, it is possible to suppress the excessive rise in the temperature of the vehicle interior and maintain the comfort of the vehicle interior.

[0017] In one embodiment of the vehicle dimming laminated glass according to the present disclosure, it is preferable that both the outer glass plate and the inner glass plate of the vehicle are colorless.

[0018] According to this embodiment, a colorless vehicle dimming laminated glass can be easily obtained.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the vehicle dimming laminated glass according to the present disclosure will be described in detail with reference to the drawings. The embodiments described below are examples for explaining the vehicle dimming laminated glass, and the vehicle dimming laminated glass is not limited to these embodiments. Therefore, the vehicle dimming laminated glass according to the present disclosure can be implemented in various forms without departing from the gist thereof.

[0021] As shown in FIG. 1, the light-adjusting laminated glass 10 according to the present embodiment (an example of a light-adjusting laminated glass for a vehicle; hereinafter, also simply referred to as laminated glass) is used, for example, for a roof glass of a vehicle. The laminated glass 10 may be used for glasses other than the roof glass of the vehicle 1, for example, rear glass, rear side glass, rear quarter glass, door glass, extra glass, front glass, etc. Note that the extra glass is a glass attached to the rear side of the vehicle 1 to improve the rear visibility of the driver of the vehicle 1.

[0022] As shown in FIG. 2, the laminated glass 10 includes a first glass plate 11 (an example of an in-vehicle side glass plate), a second glass plate 13 (an example of an outside-vehicle side glass plate), a light-adjusting sheet 20, a first intermediate layer 15 (an example of an in-vehicle side intermediate layer), and a second intermediate layer 17 (an example of an outside-vehicle side intermediate layer). The first glass plate 11 is disposed on the in-vehicle side of the vehicle 1. The second glass plate 13 faces the first glass plate 11 and is disposed on the outside-vehicle side of the vehicle 1. The light-adjusting sheet 20 is disposed between the first glass plate 11 and the second glass plate 13. The first intermediate layer 15 is disposed between the first glass plate 11 and the light-adjusting sheet 20. The second intermediate layer 17 is disposed between the second glass plate 13 and the light-adjusting sheet 20.

[0023] The laminated glass 10 is formed by laminating the first glass plate 11, the first intermediate layer 15, the light-adjusting sheet 20, the second intermediate layer 17, and the second glass plate 13, and is fixed in a state where the first intermediate layer 15, the light-adjusting sheet 20, and the second intermediate layer 17 are sandwiched between the first glass plate 11 and the second glass plate 13. The laminated glass 10 is temporarily adhered, for example, in a vacuum with the pressure controlled in the range of -100 kPa or more and -65 kPa or less and the temperature in the range of 70°C or more and 110°C or less, and then subjected to main pressure bonding in an autoclave at a pressure of, for example, 0.8 MPa or more and 1.5 MPa or less and a temperature of 100°C or more and 150°C or less to fix them to each other. These conditions are merely examples, and the heating conditions, pressure conditions, etc. are appropriately selected.

[0024] The first glass plate 11 and the second glass plate 13 are well-known glass plates, for example, common clear glass. In this embodiment, the first glass plate 11 and the second glass plate 13 are colorless and transparent. An example of the composition of clear glass is shown below.

[0025] <Clear glass> SiO2: 70% to 73% by mass Al2O3: 0.6% to 2.4% by mass CaO: 7% to 12% by mass MgO: 1.0% to 4.5% by mass R2O: 13% to 15% by mass (R is an alkali metal) Total iron oxide (T-Fe2O3) converted to Fe2O3: 0.08% to 0.14% by mass

[0026] In addition to clear glass, the first glass plate 11 and the second glass plate 13 can preferably use green glass, privacy glass, and UV cut green glass containing a predetermined amount or more of iron components. An example of the composition of privacy glass is shown below.

[0027] <Privacy glass> SiO2: 66% to 75% by mass Al2O3: 0% to 5% by mass CaO: 5% to 15% by mass MgO: 0% to 6% by mass R2O: 10% to 20% by mass (R is an alkali metal) Total iron oxide (T-Fe2O3) converted to Fe2O3: 0.5% to 2.5% by mass TiO2: 0.2% to 5% by mass Cobalt oxide (CoO) converted to CoO: 50 ppm to 500 ppm by mass Se: 0 ppm to 70 ppm by mass

[0028] The first intermediate layer 15 and the second intermediate layer 17 are formed of, for example, a thermoplastic resin. Examples of the thermoplastic resin 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, a cycloolefin polymer resin, an ionomer resin, and the like. Among these thermoplastic resins, a plasticized polyvinyl acetal resin is preferably used for the first intermediate layer 15 and the second intermediate layer 17. These thermoplastic resins may be used alone or in combination of two or more. Further, the first intermediate layer 15 includes a function as an adhesive layer for bonding the first glass plate 11 and the light control sheet 20, and the second intermediate layer 17 includes a function as an adhesive layer for bonding the second glass plate 13 and the light control sheet 20. The first intermediate layer 15 and the second intermediate layer 17 have a smaller Young's modulus than the base material 26 of the light control sheet 20 described later. Note that the materials forming the first intermediate layer 15 and the second intermediate layer 17 are not limited to thermoplastic resins.

[0029] The light control sheet 20 includes a pair of base materials 26, 26, a light control layer 22 disposed between the pair of base materials 26, 26, and a pair of conductive layers 24, 24 disposed between the light control layer 22 and each of the pair of base materials 26, 26. The light control sheet 20 may be disposed over substantially the entire surface of the laminated glass 10 or only on a part of the laminated glass 10 as required. In the present embodiment, the shape of the light control sheet 20 in plan view is substantially the same as the shape of the laminated glass 10 and is rectangular. The size of the light control sheet 20 may be smaller than the size of the laminated glass 10 with an offset or may be substantially the same as the size of the laminated glass 10.

[0030] The pair of base materials 26, 26 are both colorless and transparent resin layers. If the thickness of the base material 26 is less than 10 μm, it will be prone to wrinkling. On the other hand, if the thickness of the base material 26 exceeds 500 μm, it is not preferable from the perspective of increasing the weight of the laminated glass 10. The thickness of the base material 26 is, for example, 5 μm or more and 500 μm or less, preferably 10 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less. The material of the base material 26 is, for example, polyethylene terephthalate, polyethylene naphthalate, polyamide, or polyether.

[0031] In the dimming sheet 20, each of the pair of base materials 26, 26 supports and protects each of the pair of conductive layers 24, 24. Thereby, the handling of the dimming sheet 20 can be facilitated.

[0032] The dimming layer 22 of the present embodiment is composed of a dimming film or the like. For example, it can change the haze of the film depending on the presence or absence of energization, and create a transparent state and an opaque state. As the dimming layer 22, known ones such as polymer dispersed liquid crystal, suspended particle device, electrochromic type, and thermochromic type can be used.

[0033] The dimming layer 22 is, for example, 5 μm or more and 150 μm or less, preferably 5 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less. When the film thickness of the dimming layer 22 is 20 μm or more and 150 μm or less, the laminated glass 10 can ensure an appropriate dimming function in the dimming layer 22 while attempting to reduce the weight of the dimming layer 22.

[0034] A pair of conductive layers 24, 24 are arranged so as to sandwich the dimming layer 22, and a voltage is applied to the dimming layer 22 by supplying power. As the conductive layers 24, 24, for example, a transparent conductive oxide (TCO: Transparent Conductive Oxide) can be used. Examples of TCO include indium tin oxide (ITO: Indium Tin Oxide), aluminum-doped zinc oxide (AZO: Aluminum-doped Zinc Oxide), and indium-added cadmium oxide. Further, as the conductive layers 24, 24, transparent conductive polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT), poly(4,4-dioctylcyclopentadithiophene), a laminated film of a metal layer and a dielectric layer, silver nanowires, and metal meshes of silver or copper can be used. The conductive layers 24, 24 are not limited to these and may be formed of other materials.

[0035] The dimming layer 22 of the present embodiment is configured to be adjustable so that it becomes opaque in a non-energized state where no voltage is applied, and becomes transparent with dimming when it enters an energized state where a voltage is applied through a pair of conductive layers 24, 24. The dimming layer 22 is configured such that, for example, the total light transmittance, which is an example of the light transmittance in the non-energized state, is less than 30%, and the total light transmittance is 30% or more in the energized state. It is more preferable that the total light transmittance of the dimming layer 22 is 20% or less in the non-energized state and 40% or more in the energized state. Note that the total light transmittance of the dimming layer 22 may be adjusted not only by switching between two states of the energized state and the non-energized state, but also by changing the energization voltage stepwise so as to change in multiple steps, or by changing the energization voltage continuously so as to change continuously. Further, the dimming layer 22 may be configured to be adjustable so that it becomes transparent in the non-energized state and opaque in the energized state.

[0036] The dimming layer 22 may have a haze of 10% or more in the opaque state and less than 10% in the transparent state. It is more preferable that the dimming layer 22 has a haze of 90% or more in the opaque state and 8% or less in the transparent state.

[0037] For example, when the dimming layer 22 is configured to have a haze of 10% or less, a voltage of 30V or more is applied. With this configuration, in the laminated glass 10, the dimming layer 22 can enhance the transparency well and properly exhibit the dimming function.

[0038] 〔Infrared absorption function〕 Next, the infrared absorption function in the laminated glass 10 will be described. As described above, for example, in a low-temperature environment of -10 degrees or less, the switching time, which is the time for the dimming layer 22 to change from the transparent state (energized state to the conductive layer 24) to the opaque state (non-energized state), or from the opaque state to the transparent state, may increase. In order to suppress the increase in the switching time, it is necessary to configure the dimming layer 22 so that its temperature is not easily lowered. For this purpose, it is effective to retain as much as possible the infrared rays contained in the sunlight irradiated on the laminated glass 10 from the outside of the vehicle 1 within the laminated glass 10. By retaining the infrared rays within the laminated glass 10, the laminated glass 10 is heated by the infrared rays. For this purpose, it is necessary to suppress the amount of infrared rays in the sunlight emitted from the laminated glass 10 to the outside of the vehicle 1 and the inside (passenger compartment) of the vehicle 1.

[0039] As described above, the tin-doped indium oxide used for the conductive layer 24 has the function of absorbing and reflecting infrared rays. Therefore, a part of the infrared rays of the sunlight irradiated onto the laminated glass 10 from the outside of the vehicle 1 is absorbed by the conductive layer 24, but a part is reflected by the conductive layer 24 and released to the outside of the vehicle 1. In order to suppress this, in the present embodiment, the second intermediate layer 17 is provided with an infrared absorption function capable of absorbing infrared rays. Specifically, the infrared absorber 18 is uniformly included in the second intermediate layer 17 to provide the infrared absorption function. Further, not only this configuration but also the infrared absorber 18 may be included so as to be unevenly distributed in the second intermediate layer 17. The infrared absorber 18 in the present embodiment is configured to include at least one of fine particles of tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and cesium-doped tungsten oxide (CWO). A plurality of types of these fine particles may be included in the second intermediate layer 17. Since these fine particles have a high heat ray shielding function and are easily available, they are preferably used as the infrared absorber 18.

[0040] In addition to those listed above, examples of materials that can be used as the infrared absorber 18 include fine particles of metal oxides such as aluminum-doped tin oxide, gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), niobium-doped titanium oxide, sodium-doped tungsten oxide, cesium-doped tungsten oxide, thallium-doped tungsten oxide, rubidium-doped tungsten oxide, tin-doped zinc oxide, and silicon-doped zinc oxide, and fine particles of lanthanum hexaboride (LaB6).

[0041] By including the infrared absorber 18 in the second intermediate layer 17, the infrared rays of sunlight irradiated on the laminated glass 10 and reflected by the conductive layer 24 are absorbed by the infrared absorber 18. Therefore, the infrared rays are not emitted to the outside of the vehicle 1 and remain inside the laminated glass 10. As a result, the heating of the light control layer 22 by the infrared rays is promoted, so that the temperature of the light control layer 22 hardly decreases even in a low temperature environment, and an increase in the switching time for the light control layer 22 to change from a transparent state to an opaque state or from an opaque state to a transparent state is suppressed. Since the fine particles of tin-doped indium oxide are colorless and transparent, the laminated glass 10 is not colored even when the infrared absorber 18 is disposed in the second intermediate layer 17.

[0042] Also, in the present embodiment, the first glass plate 11 has a Low-E (Low Emissivity) film 11a on the vehicle interior side. Since the first glass plate 11 has the Low-E film 11a, at least a part of the infrared rays of sunlight irradiated on the laminated glass 10 from the outside of the vehicle 1 and transmitted through the light control sheet 20 is reflected by the Low-E film 11a and returns toward the light control sheet 20, so that it is difficult for the infrared rays to be emitted into the vehicle interior. Therefore, an increase in the temperature inside the vehicle due to infrared rays can be suppressed, and the infrared rays can be retained inside the laminated glass 10 to suppress a temperature drop of the light control layer 22. Thereby, the comfort inside the vehicle can be maintained. The Low-E film 11a is well-known and a detailed description thereof is omitted, but it is made of, for example, a metal oxide.

Example

[0043] Next, an example of the laminated glass 10 manufactured by the method described in the above embodiment will be described.

[0044] <Examples 1 and 2> The laminated glass 10 according to Examples 1 and 2 is each formed by laminating and fixing a first glass plate 11 having a Low-E film 11a, a first intermediate layer 15, a dimming sheet 20, a second intermediate layer 17 containing an infrared absorber 18, and a second glass plate 13. The difference between Example 1 and Example 2 is only that the concentration of the infrared absorber 18 in Example 2 is twice the concentration of the infrared absorber 18 in Example 1. Note that both the first glass plate 11 and the second glass plate 13 are made of clear glass. Both the first intermediate layer 15 and the second intermediate layer 17 are made of a plasticized polyvinyl acetal resin. In the dimming sheet 20, the dimming layer 22 is made of polymer-dispersed liquid crystal, the conductive layer 24 is made of tin-doped indium oxide, and the base material 26 is made of polyethylene terephthalate, respectively.

[0045] <Comparative Example 1> The laminated glass of Comparative Example 1 is different from Example 1 in that the first glass plate 11 does not have a Low-E film 11a, and has the same configuration as Example 1 otherwise.

[0046] <Comparative Example 2> The laminated glass of Comparative Example 2 is different from Examples 1 and 2 in that the second intermediate layer 17 does not contain an infrared absorber 18, and has the same configuration as Examples 1 and 2 otherwise.

[0047] <Comparative Example 3> The laminated glass of Comparative Example 3 is different from Examples 1 and 2 in that the first glass plate 11 does not have a Low-E film 11a and the second intermediate layer 17 does not have an infrared absorber 18, and has the same configuration as Examples 1 and 2 otherwise.

[0048] In the above Examples 1 and 2 and Comparative Examples 1 to 3, the direct solar radiation absorption rate (α e ), the total solar radiation transmittance (T ts) and the switching time of the dimming layer 22 when the ambient temperature around the laminated glass is -10 degrees (minus 10 degrees) was measured. The switching time of the dimming layer 22 was measured as the time taken to change from the transparent state to the opaque state and the time taken to change from the opaque state to the transparent state, and the average of these times was calculated. The numerical values of both the direct solar radiation absorption rate and the total solar radiation transmittance are determined in accordance with ISO13837:2021.

[0049] The direct solar radiation absorption rate is a value obtained by subtracting from 1 the ratio of the total value of the amount of heat transmitted through the laminated glass and released into the vehicle interior and the amount of heat released from the laminated glass to the outside of the vehicle 1 to the total amount of heat of sunlight incident on the laminated glass. The larger this value, the less infrared radiation is released from the laminated glass to the vehicle interior and the outside of the vehicle 1, indicating that more infrared radiation remains inside the laminated glass. The direct solar radiation absorption rate is preferably 80% or more.

[0050] The total solar radiation transmittance is a numerical value indicating the ratio of the total value of the amount of solar radiation transmitted through the laminated glass and the amount of solar radiation heat that was once absorbed by the laminated glass and then released into the vehicle interior to the total amount of solar radiation heat of sunlight incident on the laminated glass. The smaller this value, the less infrared radiation is transmitted through the laminated glass and released into the vehicle interior of the vehicle 1, indicating that more infrared radiation remains inside the laminated glass. The total solar radiation transmittance is preferably 25% or less.

[0051] From the perspective of responsiveness, the switching time is preferably within 1 second. The results of this measurement are shown in Table 1 below.

[0052]

Table 1

[0053] As shown in Table 1, in both Example 1 and Example 2, the direct solar radiation absorption rate is 80% or more, the total solar transmittance is 25% or less, and the switching time at -10 degrees is 1 second or less, indicating that the above preferred specifications are met. It can be seen that Example 2 had better direct solar radiation absorption rate and total solar transmittance than Example 1. This is presumably because the concentration of the infrared absorber 18 contained in the laminated glass 10 of Example 2 was twice that of the infrared absorber 18 in the laminated glass 10 of Example 1, resulting in more infrared rays remaining inside the laminated glass 10 in Example 2.

[0054] In Comparative Example 1, the direct solar radiation absorption rate was 80% or more, but the total solar transmittance was 29.1%, exceeding 25%, and the switching time at -10 degrees was 2 seconds, exceeding 1 second. This is presumably because the first glass plate 11 of the laminated glass in Comparative Example 1 did not have a Low-E film 11a, so more infrared rays were released into the passenger compartment of the vehicle 1 compared to Example 1 and Example 2, and less infrared rays remained inside the laminated glass.

[0055] In Comparative Example 2, the total solar transmittance was 25% or less, but the direct solar radiation absorption rate was 74.4%, falling below 80%, and the switching time at -10 degrees was 2 seconds, exceeding 1 second. This is presumably because the second intermediate layer 17 of the laminated glass in Comparative Example 2 did not contain an infrared absorber 18, so more infrared rays were released to the outside of the vehicle 1 compared to Example 1 and Example 2, and less infrared rays remained inside the laminated glass.

[0056] In Comparative Example 3, the direct solar radiation absorption rate was 74.4%, falling below 80%, the total solar transmittance was 29.2%, exceeding 25%, and the switching time at -10 degrees was 2 seconds, exceeding 1 second. The laminated glass in Comparative Example 3 has a first glass plate 11 without a Low-E film 11a and a second intermediate layer 17 without an infrared absorber 18. Therefore, more infrared rays were released to the outside and inside the passenger compartment of the vehicle 1 compared to Example 1 and Example 2, and less infrared rays remained inside the laminated glass compared to Comparative Example 1 and Comparative Example 2.

[0057] [Other Embodiment] (1) In the laminated glass 10 of the above embodiment, an infrared reflecting film may be further provided between the second glass plate 13 and the second intermediate layer 17. By providing the infrared reflecting film, infrared rays transmitted through the second intermediate layer 17 and transmitted to the second glass plate 13 can be reflected without being transmitted to the second glass plate 13. As a result, more infrared rays can be retained inside the laminated glass 10 than in the laminated glass 10 of the present embodiment. When the infrared reflecting film is provided, the second intermediate layer 17 may not contain the infrared absorber 18 as long as an increase in the switching time of the light control layer 22 in a low temperature environment is suppressed. Even in these cases, the second intermediate layer 17 has an infrared absorption function.

[0058] (2) In the above other embodiment (1), the infrared reflecting film was disposed at the boundary between the second intermediate layer 17 and the second glass plate 13, but the present invention is not limited to this. The infrared reflecting film may be disposed at the boundary between the second intermediate layer 17 and the base material 26 of the light control sheet 20 instead of at the boundary between the second intermediate layer 17 and the second glass plate 13. Also in this case, the second intermediate layer 17 has an infrared absorption function.

[0059] (3) In the above embodiment, the first glass plate 11 and the second glass plate 13 of the laminated glass 10 were colorless, but at least one of the first glass plate 11 and the second glass plate 13 may be dark-colored. By making at least one of the first glass plate 11 and the second glass plate 13 dark-colored, more infrared rays of sunlight can be absorbed by the laminated glass 10. The dark-colored glass plate may be, for example, the privacy glass described above or a heat ray absorbing glass plate as described below. The composition of the heat ray absorbing glass can be, for example, based on the composition of the above-mentioned clear glass, with the ratio of total iron oxide (T-Fe2O3) converted to Fe2O3 being 0.4 mass% to 1.3 mass%, the ratio of CeO2 being 0 mass% to 2 mass%, the ratio of TiO2 being 0 mass% to 0.5 mass%, and the glass skeleton components (mainly SiO2 and Al2O3) being reduced by the increase amounts of T-Fe2O3, CeO2, and TiO2.

[0060] (4) In the above embodiment, the first intermediate layer 15 and the second intermediate layer 17 were colorless, but at least one of the first intermediate layer 15 and the second intermediate layer 17 may be dark-colored. By making at least one of the first intermediate layer 15 and the second intermediate layer 17 dark-colored, the laminated glass 10 can absorb more infrared rays of sunlight. Note that the first intermediate layer 15 and the second intermediate layer 17 may have a colored portion called a shade band.

Industrial Applicability

[0061] The present disclosure can be used for a light-adjusting laminated glass for vehicles.

Explanation of Reference Numerals

[0062] 1: Vehicle 10: Light-adjusting laminated glass (light-adjusting laminated glass for vehicles) 11: First glass plate (inner glass plate of the vehicle) 11a: Low-E film 13: Second glass plate (outer glass plate of the vehicle) 15: First intermediate layer (inner intermediate layer of the vehicle) 17: Second intermediate layer (outer intermediate layer of the vehicle) 18: Infrared absorber 20: Light-adjusting sheet 22: Light-adjusting layer 24: Conductive layer

Claims

1. A light-adjusting laminated glass for vehicles used in a vehicle, comprising: an outer vehicle glass plate disposed on the outer side of the vehicle; an inner vehicle glass plate disposed on the inner side of the vehicle; a light-adjusting sheet disposed between the outer vehicle glass plate and the inner vehicle glass plate; an outer vehicle intermediate layer provided between the outer vehicle glass plate and the light-adjusting sheet; an inner vehicle intermediate layer provided between the inner vehicle glass plate and the light-adjusting sheet; wherein the light-adjusting sheet has a light-adjusting layer capable of adjusting the light transmittance when a voltage is applied, and a pair of conductive layers disposed so as to sandwich the light-adjusting layer and applying a voltage to the light-adjusting layer when power is supplied; The light-adjusting laminated glass for vehicles, wherein the outer vehicle intermediate layer has an infrared absorption function.

2. The light-adjusting laminated glass for vehicles according to Claim 1, wherein the light-adjusting layer contains polymer dispersed liquid crystal.

3. The light-adjusting laminated glass for vehicles according to Claim 1, wherein the outer vehicle intermediate layer has the infrared absorption function by an infrared absorber.

4. The light-adjusting laminated glass for vehicles according to Claim 3, wherein the infrared absorber contains at least one fine particle of tin-doped indium oxide, antimony-doped tin oxide, and cesium-doped tungsten oxide.

5. The light-adjusting laminated glass for vehicles according to any one of Claims 1 to 4, wherein a Low-E film is disposed on the inner surface of the inner vehicle glass plate.

6. The light-adjusting laminated glass for vehicles according to any one of Claims 1 to 4, wherein both the outer vehicle glass plate and the inner vehicle glass plate are colorless.

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