Laminated glass, laminated glass for vehicle, and laminated glass for vehicle roof

Abstract

Provided is laminated glass capable of suppressing reflection of interior decoration or the like even in a state in which light is shielded. A laminated glass (10) according to one embodiment of the present invention comprises a first glass plate (11), a first intermediate film (12), a PDLC-type light control film (13), a second intermediate film (14), and a second glass plate (15) in this order, the total light transmittance of the laminated glass (10) is 10% or less and the haze value is 50% or more when the PDLC-type light control film (13) is closed, and the second glass plate (15) has a low-emissivity film (16) on the surface on the opposite side from the second intermediate film (14) side. The visible light reflectance on the surface of the low-emissivity film (16) on the opposite side from the second glass plate (15) side is 0.2% or more and 3.8% or less.

Description

Technical Field

[0001] This invention relates to laminated glass, laminated glass for vehicles, and laminated glass for vehicle roofs. Background Technology

[0002] As is well known, forming a low-emissivity film on the window glass of automobiles, buildings, and ships can suppress heat transfer through the window glass. Suppressing heat transfer through the window glass improves the comfort of passengers and occupants inside automobiles, buildings, and ships. Laminated glass with a low-emissivity film formed on the interior surface suppresses the re-radiation of heat from the outside, such as sunlight, and also suppresses the loss of heat emitted by people inside to the outside, thereby suppressing heat transfer between the outside and inside through the glass.

[0003] Patent document 1 discloses a technique for forming a low-emissivity film on the indoor side of a substrate.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2015-512854 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In recent years, a technology has been developed for using dimming laminated glass in windows of buildings or vehicles. Such dimming laminated glass can be constructed by incorporating a dimming film within the laminated glass. For example, a PDLC-type dimming film can be used as the dimming film for laminated glass. In this type of laminated glass, by forming a low-emissivity film on the interior surface of the glass, both indoor comfort and privacy can be improved.

[0009] However, when laminated glass with a low-emissivity film is switched to a light-blocking state using a dimming film, the amount of light from outside is reduced. Therefore, the reflection of interior decorations and other elements onto the laminated glass becomes more noticeable.

[0010] Furthermore, when using PDLC-type dimming film as a dimming film for laminated glass, due to the working principle of PDLC-type dimming film, the laminated glass may appear grainy when viewed from the indoor side. When the graininess becomes obvious, it may produce a unique sense of discomfort (hazy discomfort).

[0011] In view of the above-mentioned technical problems, the object of the present invention is to provide laminated glass, laminated glass for vehicles, and laminated glass for vehicle roofs that can suppress the reflection of interior decorations and other elements and suppress the feeling of haziness even when the light is blocked.

[0012] Technical solutions adopted to solve technical problems

[0013] A vehicle glass panel, vehicle laminated glass, and vehicle roof laminated glass according to one embodiment of the present disclosure have the following structure.

[0014] [1] A laminated glass comprising, in sequence, a first glass plate, a first interlayer film, a PDLC-type dimming film, a second interlayer film, and a second glass plate, wherein, When the PDLC dimming film is closed, the total light transmittance of the laminated glass is below 10%, and the haze value is above 50%. The second glass plate has a low-emissivity film on the surface opposite to the second intermediate film side. The visible light reflectance of the surface of the low-emissivity film on the side opposite to the second glass plate is above 0.2% and below 3.8%.

[0015] [2] As described in [1], wherein, The low-emissivity film has a transparent conductive layer and a reflectance adjustment layer sequentially from the second glass plate side. The ratio of the thickness of the reflective adjustment layer to the thickness of the transparent conductive layer is greater than 0.47 and less than 0.70.

[0016] [3] A laminated glass comprising, in sequence, a first glass plate, a first interlayer film, a PDLC-type dimming film, a second interlayer film, and a second glass plate, wherein, When the PDLC dimming film is closed, the total light transmittance of the laminated glass is below 10%, and the haze value is above 50%. The second glass plate has a low-emissivity film on the surface opposite to the second intermediate film side. The low-emissivity film has a transparent conductive layer and a reflectance adjustment layer sequentially from the second glass plate side. The ratio of the thickness of the reflective adjustment layer to the thickness of the transparent conductive layer is greater than 0.47 and less than 0.70.

[0017] [4] The laminated glass as described in [3], wherein the visible light reflectance of the surface of the low-emissivity film on the side opposite to the second glass plate is greater than 0.2% and less than 3.8%.

[0018] [5] The laminated glass as described in any one of [2] to [4], wherein the thickness of the transparent conductive layer is above 80 nm and below 160 nm.

[0019] [6] The laminated glass as described in any one of [2] to [5], wherein the transparent conductive layer is an ITO layer, a tin oxide layer, a fluorine-doped tin oxide layer, an antimony-doped tin oxide layer, a silver layer, a zirconium nitride layer, or a titanium nitride layer.

[0020] [7] The laminated glass as described in any one of [2] to [6], wherein the reflective adjustment layer comprises an oxide or oxynitride of at least one metal selected from Ti, Nb, Ta, Zn, Al, In, Si and Zr.

[0021] [8] The laminated glass as described in any one of [2] to [7], wherein the thickness of the reflective adjustment layer is 50 nm or more and 100 nm or less.

[0022] [9] The laminated glass as described in any one of [2] to [8], wherein, The low-emissivity film also has a color correction layer. The tone correction layer is composed of multiple layers, including a first layer and a second layer sequentially from the second glass plate side. The first layer has a higher refractive index for light with a wavelength of 630 nm than the second layer.

[0023]

[10] The laminated glass as described in [9], wherein the first layer has a refractive index of 1.7 or higher and 2.5 or lower for light with a wavelength of 630 nm, and the second layer has a refractive index of 1.6 or lower for light with a wavelength of 630 nm.

[0024]

[11] The laminated glass as described in any one of [2] to

[10] , wherein the low-emissivity film further comprises a hue correction layer comprising an oxide or oxynitride of at least one metal selected from Ti, Nb, Ta, Zn, Al, In, Si and Zr.

[0025]

[12] The laminated glass as described in any one of [2] to

[11] , wherein the low-emissivity film has a hue correction layer between the surface of the second glass plate facing the low-emissivity film and the transparent conductive layer, the hue correction layer having a film thickness of more than 20 nm and less than 60 nm.

[0026]

[13] The laminated glass as described in any one of [1] to

[12] , wherein the emissivity of the low-emissivity film on the surface opposite to the second glass plate side is less than 0.3.

[0027]

[14] The laminated glass as described in any one of [2] to

[13] , wherein the low-emissivity film has an adhesion-improving layer disposed between the transparent conductive layer and the reflection-adjusting layer.

[0028]

[15] A laminated glass for vehicles, having any one of [1] to

[14] laminated glass.

[0029]

[16] A laminated glass for vehicle roof, having any one of [1] to

[14] laminated glass.

[0030] Invention Effects

[0031] According to the present invention, a laminated glass, a laminated glass for vehicles, and a laminated glass for vehicle roofs can be provided that can suppress the reflection of interior decorations and other elements and suppress the feeling of haziness even when the light is blocked. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view illustrating an example of the structure of the laminated glass according to an embodiment.

[0033] Figure 2 This is a cross-sectional view illustrating an example of a low-emissivity film provided with the laminated glass of the embodiment.

[0034] Figure 3 A cross-sectional view showing a modified example of the low-emissivity film provided in the laminated glass of the embodiment.

[0035] Figure 4 A cross-sectional view showing a modified example of the low-emissivity film provided in the laminated glass of the embodiment. Detailed Implementation

[0036] The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0037] Figure 1 This is a cross-sectional view illustrating an example of the structure of the laminated glass according to this embodiment. Figure 1 As shown, the laminated glass 10 of this embodiment sequentially comprises: a first glass plate 11, a first interlayer film 12, a PDLC type dimming film 13, a second interlayer film 14, a second glass plate 15, and a low-emissivity film 16.

[0038] The laminated glass 10 described in this embodiment can be applied, for example, to window glass in automobiles, buildings, and ships. The laminated glass 10 is suitable for vehicle laminated glass. From the viewpoint of excellent thermal insulation, the laminated glass 10 is particularly suitable for vehicle roof laminated glass, etc. Vehicle roof laminated glass is used for the roof of a vehicle. The laminated glass 10 is installed such that the side facing the first glass panel 11 faces outwards or outdoors, and the side facing the low-emissivity film 16 faces inwards or indoors. Hereinafter, "outwards or outdoors" will sometimes be simply referred to as "outer". Furthermore, "inwards or indoors" will sometimes be simply referred to as "indoors".

[0039] The PDLC-type dimming film 13 is a dimming film employing polymer-dispersed liquid crystal (PDLC). The PDLC-type dimming film 13 has a dimming function where the transmittance changes with the applied voltage. By adjusting the voltage applied to the PDLC-type dimming film 13, the transmittance of the laminated glass 10 to visible and near-infrared light can be reversibly controlled. By reducing the transmittance of the laminated glass 10 to visible and near-infrared light, heat rays from the outside to the inside can be blocked, thereby suppressing the rise in indoor temperature. Furthermore, by reducing the transmittance of the laminated glass 10 to visible light, visible light from the inside to the outside can be blocked, making it difficult to see inside from the outside. Therefore, the laminated glass 10 can regulate the indoor environment and ensure privacy.

[0040] In this embodiment, when the PDLC-type dimming film 13 is turned off, the total light transmittance of the laminated glass 10 is less than 10%, and the haze value is more than 50%. Here, "turning off the PDLC-type dimming film 13" means adjusting the parallel light transmittance of the laminated glass 10 to a minimum by adjusting the voltage applied to the PDLC-type dimming film 13. In other words, "turning off the PDLC-type dimming film 13" means adjusting the light transmitted through the laminated glass 10 to a blocked state. When the PDLC-type dimming film 13 is turned off, the haze value of the laminated glass 10 reaches its maximum.

[0041] The lower the total light transmittance of the laminated glass 10 when the PDLC dimming film 13 is turned off, the better; ideally, it should be close to 0%. From the viewpoint of regulating the indoor environment and ensuring privacy, the total light transmittance of the laminated glass 10 when the PDLC dimming film 13 is turned off is preferably below 10%, more preferably below 8%, further preferably below 6%, further preferably below 5%, particularly preferably below 3%, even more particularly preferably below 2%, extremely preferably below 1%, even more extremely preferably below 0.5%, further extremely preferably below 0.3%, particularly extremely preferably below 0.1%, and even more particularly extremely preferably below 0.05%. When it is desirable to see the outside scenery from inside the vehicle, the total light transmittance of the laminated glass 10 when the PDLC dimming film 13 is turned off can be above 0.01%. From a privacy perspective, the haze value of the laminated glass 10 when the PDLC dimming film 13 is closed is preferably 50% or higher, more preferably 60% or higher, further preferably 70% or higher, particularly preferably 80% or higher, even more preferably 85% or higher, extremely preferably 90% or higher, and particularly extremely preferably 95% or higher. Furthermore, the total light transmittance is a value measured using a spectrophotometer. The haze value is a value measured using a haze meter. The total light transmittance and haze value of the laminated glass 10 can be measured in a laboratory or when installed in a vehicle, etc.

[0042] The types of the first glass plate 11 and the second glass plate 15 are not particularly limited. The first glass plate 11 and the second glass plate 15 may be, for example, soda-lime glass, quartz glass, borosilicate glass, or alkali-free glass. From the viewpoint of ease of bending, the first glass plate 11 and the second glass plate 15 are preferably soda-lime glass.

[0043] The first glass plate 11 and the second glass plate 15 can be colorless or colored. The thickness of the first glass plate 11 and the second glass plate 15 is preferably 0.5 mm or more, more preferably 0.8 mm or more, further preferably 1.0 mm or more, particularly preferably 1.3 mm or more, and particularly more preferably 1.6 mm or more. The thickness of the first glass plate 11 and the second glass plate 15 is preferably 5.0 mm or less, more preferably 4.5 mm or less, further preferably 4.0 mm or less, particularly preferably 3.5 mm or less, and particularly more preferably 3.2 mm or less. The thickness of the first glass plate 11 and the second glass plate 15 can be the same or different from each other. Furthermore, the first glass plate 11 and the second glass plate 15 can be ultraviolet-blocking glass plates capable of blocking ultraviolet rays. An ultraviolet-blocking glass plate is a glass plate with reduced ultraviolet transmittance; for example, it can be a borosilicate glass containing a copper compound. Here, the copper compound is, for example, cuprous oxide.

[0044] The first intermediate film 12 and the second intermediate film 14 are preferably made of, for example, a transparent resin. The resin constituting the first intermediate film 12 and the second intermediate film 14 is, for example, polyvinyl butyral (PVB), polyvinyl chloride, ethylene-vinyl acetate copolymer (EVA), cyclic olefin polymers, polyurethane resins, polyvinylidene fluoride (PVDF), etc. The film thickness of the first intermediate film 12 and the second intermediate film 14 is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more. The film thickness of the first intermediate film 12 and the second intermediate film 14 is preferably 2.0 mm or less, more preferably 1.0 mm or less, and even more preferably 0.7 mm or less. Furthermore, the first intermediate film 12 and the second intermediate film 14 can be colorless or colored. The first intermediate film 12 and the second intermediate film 14 can be colored, for example, by using a resin containing a colorant such as a pigment.

[0045] The visible light reflectance on the surface of the low-emissivity film 16 opposite to the side of the second glass plate 15 (the interior side surface) is 3.8% or less. Therefore, even when the PDLC-type dimming film 13 is turned off, i.e., when the light transmitted from the side of the first glass plate 11 is small, the laminated glass 10 can suppress the absolute value of visible light reflection. Therefore, the reflection of interior decorations, etc., onto the laminated glass 10 when viewing the first glass plate 11 side from the low-emissivity film 16 side can be suppressed. In other words, the reflection of interior decorations, etc., onto the laminated glass 10 when viewing the laminated glass 10 from the interior side can be suppressed. From the viewpoint of sufficiently suppressing the reflection of interior decorations, etc., the visible light reflectance on the interior side surface of the low-emissivity film 16 is preferably 3.6% or less, more preferably 3.5% or less, further preferably 3.3% or less, particularly preferably 3.0% or less, particularly more preferably 2.8% or less, extremely preferably 2.5% or less, even more preferably 2.3% or less, further extremely preferably 2.0% or less, particularly extremely preferably 1.8% or less, and particularly extremely preferably 1.5% or less. Furthermore, from the viewpoint of suppressing discomfort caused by haze, the visible light reflectance of the indoor side surface of the low-emissivity film 16 is preferably 0.2% or more, more preferably 0.5% or more, even more preferably 0.8% or more, and particularly preferably 1.0% or more. The visible light reflectance is a value measured according to the method specified in JIS R3106.

[0046] Regarding the laminated glass 10, due to the working principle of the PDLC-type dimming film 13, the laminated glass may appear grainy when viewed from the low-emissivity film surface. When the graininess becomes noticeable, people indoors may experience discomfort. The discomfort caused by the noticeable graininess will be referred to as "hazy discomfort" below. From the viewpoint of suppressing hazy discomfort, the visible light reflectance of the surface of the low-emissivity film 16 on the side opposite to the second glass plate 15 is preferably 0.2% or more, more preferably 1.0% or more.

[0047] The laminated glass 10 may contain heat due to sunlight or other light from the outside. The low-emissivity film 16 suppresses the re-radiation of the heat contained in the laminated glass 10 into the room, thereby suppressing the rise in indoor temperature during summer and other periods. Furthermore, the low-emissivity film 16 suppresses the diffusion of heat from the room to the outside, thereby suppressing the drop in indoor temperature during winter and other periods. Therefore, the low-emissivity film 16 has an environmental regulation function that regulates the indoor environment. From the viewpoint of fully utilizing the environmental regulation function, the emissivity on the surface of the low-emissivity film 16 opposite to the side of the second glass plate 15 is preferably 0.3 or less. Herein, the emissivity is a value measured according to the measurement method specified in JIS R 1801.

[0048] The low-emissivity film 16 may include, for example, a transparent conductive layer 21, a reflection adjustment layer 22, and other layers. In this embodiment, the case where the low-emissivity film 16 includes a transparent conductive layer 21 and a reflection adjustment layer 22 will be described. Figure 2This is a cross-sectional view showing an example of the low-emissivity film provided in the laminated glass 10 of Embodiment 1. The low-emissivity film 16 provided in the laminated glass 10 of this embodiment has a transparent conductive layer 21 and a reflective adjustment layer 22 sequentially from the side of the second glass plate 15.

[0049] The transparent conductive layer 21 is preferably an ITO (Indium Tin Oxide) layer, a tin oxide layer, a fluorine-doped tin oxide layer, an antimony-doped tin oxide layer, a silver layer, a zirconium nitride layer, or a titanium nitride layer. The transparent conductive layer 21 may contain additives. When the transparent conductive layer 21 is an ITO layer, the additives may be, for example, Ga, Zn, Al, and / or Nb. When the transparent conductive layer 21 is an ITO layer, from the viewpoint of reducing resistance, the proportion of tin oxide contained in the ITO layer is preferably 5% by mass or more and 12.5% ​​by mass or less, more preferably 6.5% by mass or more and 11% by mass or less. Furthermore, the ITO layer may contain less than 50% by mass of other materials besides ITO. Other materials contained in the ITO layer may be, for example, sodium, lead, and / or iron.

[0050] From the viewpoint of achieving sufficient low-emissivity performance and obtaining necessary thermal insulation performance, the thickness of the transparent conductive layer 21 is preferably 80 nm or more, more preferably 85 nm or more, particularly preferably 90 nm or more, particularly more preferably 95 nm or more, and extremely preferably 100 nm or more. From the viewpoint of improving productivity, the thickness of the transparent conductive layer 21 is preferably 160 nm or less, more preferably 155 nm or less, and particularly preferably 150 nm or less. The refractive index of the transparent conductive layer 21 for light with a wavelength of 630 nm is preferably 1.7 or more and 1.8 or less.

[0051] The reflectivity adjustment layer 22 preferably comprises an oxide or oxynitride of at least one metal selected from Ti, Nb, Ta, Zn, Al, In, Si, and Zr, and more preferably an oxide containing Si. From the viewpoint of reducing the reflectivity of light in the visible light region, the film thickness of the reflectivity adjustment layer 22 is preferably 50 nm or more and 100 nm or less. The film thickness of the reflectivity adjustment layer 22 is preferably 55 nm or more, and more preferably 60 nm or more. The film thickness of the reflectivity adjustment layer 22 is more preferably 95 nm, particularly preferably 90 nm or less, particularly more preferably 85 nm or less, and extremely preferably 80 nm or less. From the viewpoint of achieving sufficiently low emissivity, the refractive index of the reflectivity adjustment layer 22 for light with a wavelength of 630 nm is preferably 1.7 or less, and more preferably 1.55 or less.

[0052] From the viewpoint of reducing the reflectivity and emissivity of light in the visible light region, the ratio of the thickness of the transparent conductive layer 21 to the thickness of the reflection adjustment layer 22 is preferably 0.47 or more and 0.70 or less. More preferably, the ratio is 0.48 or more, particularly preferably 0.49 or more, and even more preferably 0.50 or more. More preferably, the ratio is 0.68 or less, particularly preferably 0.65 or less, even more preferably 0.63 or less, and extremely preferably 0.60 or less.

[0053] Figure 2 The low-emissivity film 16 shown is only one example; in this embodiment, the low-emissivity film 16 may also have other structures. See below for reference. Figure 3 and Figure 4 To illustrate a variation of the low-emissivity film 16. Figure 3 and Figure 4 A cross-sectional view showing a modified example of the low-emissivity film provided in the laminated glass of the embodiment.

[0054] Figure 3 The low-emissivity film 17 shown also includes a tone correction layer 23. The tone correction layer 23 is disposed, for example, between the second glass plate 15 and the transparent conductive layer 21. The tone correction layer 23 may contain an oxide or oxynitride of at least one metal selected from Ti, Nb, Ta, Zn, Al, In, Si, and Zr. From the viewpoint of reducing the dependence of reflected light angle, the thickness of the tone correction layer 23 is preferably 20 nm or more, more preferably 25 nm or more, and particularly preferably 30 nm or more. From the viewpoint of reducing the dependence of reflected light angle, the thickness of the tone correction layer 23 is preferably 60 nm or less, more preferably 55 nm or less, and particularly preferably 50 nm or less.

[0055] The tone correction layer 23 may also be composed of multiple layers, including a first layer and a second layer sequentially from the side of the second glass plate 15. The refractive index of the first layer for light with a wavelength of 630 nm is higher than that of the second layer for light with a wavelength of 630 nm. The refractive index of the first layer for light with a wavelength of 630 nm is preferably 1.7 or higher and 2.5 or lower, more preferably 1.8 or higher and 2.3 or lower, and particularly preferably 1.8 or higher and 2.2 or lower. The refractive index of the second layer for light with a wavelength of 630 nm is preferably 1.6 or lower, more preferably 1.55 or lower.

[0056] The first layer preferably comprises an oxide or oxynitride of at least one metal selected from Ti, Nb, Ta, Zn, Al, In, Si, and Zr. More preferably, the first layer comprises ZrO2 doped with 0.1% by mass or more and 10% by mass of Si. The thickness of the first layer is preferably 3 nm or more, more preferably 5 nm or more, particularly preferably 7 nm or more, and particularly more preferably 9 nm or more. The thickness of the first layer is preferably 40 nm or less, more preferably 35 nm or less, further preferably 30 nm or less, particularly preferably 25 nm or less, particularly more preferably 23 nm or less, extremely preferably 20 nm or less, even more preferably 18 nm or less, further extremely preferably 17 nm or less, and particularly extremely preferably 15 nm or less.

[0057] The second layer is preferably composed of a material mainly composed of SiO2, SiON, or MgF2, more preferably of a material mainly composed of SiO2. The thickness of the second layer is preferably 5 nm or more, more preferably 10 nm or more. The thickness of the second layer is preferably 50 nm or less, more preferably 45 nm or less.

[0058] Figure 4 The low-emissivity film 18 shown also includes an adhesion improvement layer 24. The adhesion improvement layer 24 is disposed between the transparent conductive layer 21 and the reflection adjustment layer 22. The adhesion improvement layer 24 is preferably composed of metal oxides such as tin oxide, zinc oxide, and cerium oxide. The film thickness of the adhesion improvement layer 24 is preferably 1 nm or more and 10 nm or less.

[0059] in addition, Figure 1 The laminated glass 10 shown is only one example; in this embodiment, the laminated glass 10 may also have other structures. For example, a self-cleaning film may be provided on the surface of the first glass plate 11 opposite to the side of the first interlayer film 12. Compared with dirt adhering to the glass surface without a self-cleaning film, dirt adhering to the surface of the self-cleaning film is more easily removed by contact with water such as rainwater. The self-cleaning film may be made of, for example, titanium dioxide-based materials, silicon dioxide-based materials, or siloxane-based materials. The thickness of the self-cleaning film is, for example, 5 nm or more and 50 nm or less, preferably 10 nm or more and 40 nm or less, and more preferably 15 nm or more and 35 nm or less.

[0060] Furthermore, an infrared reflective film can be disposed between the first glass plate 11 and the PDLC-type dimming film 13 in the laminated glass 10. The infrared reflective film can be disposed between the first glass plate 11 and the first intermediate film 12, or it can be disposed inside the first intermediate film 12. The infrared reflective film selectively reflects infrared rays, thereby suppressing the rise in indoor temperature and suppressing the thermal degradation of the first intermediate film 12 and the second intermediate film 14, etc. The infrared reflective film can be composed of multiple layers. For example, the infrared reflective film can be constructed such that at least one layer of the multiple layers contains an infrared reflective material. The infrared reflective material is a material capable of reflecting infrared rays, such as transparent conductive oxides like silver (Ag), indium tin oxide, zinc oxide, fluorine-doped tin oxide, or any other suitable material capable of blocking a large amount of infrared radiation. The infrared reflective film can, for example, be constructed having a layer containing a dielectric (dielectric layer) and a layer containing Ag (Ag layer). The dielectric can be, for example, silicon nitride, titanium oxide, silicon oxynitride, tin oxide, other types of metal (alloy) oxides, or other types of metal (alloy) nitrides, etc. Examples of other types of metal oxides include zinc tin oxide, zinc aluminum oxide, nickel chromium oxide, silver oxide, and zinc oxide. The infrared reflective film can, for example, be a structure consisting of at least one pair of dielectric layers sandwiching an Ag layer. Furthermore, the infrared reflective film can contain multiple Ag layers. From the viewpoint of achieving sufficient infrared reflectivity and suppressing manufacturing costs, the infrared reflective film preferably contains two or three Ag layers. In the case of containing two Ag layers, the infrared reflective film preferably has the following structure: starting from the first glass plate 11 side, it contains multiple dielectric layers, Ag layers, multiple dielectric layers, Ag layers, and multiple dielectric layers. In the case of containing three Ag layers, the infrared reflective film preferably has the following structure: starting from the first glass plate 11 side, it contains multiple dielectric layers, Ag layers, multiple dielectric layers, Ag layers, multiple dielectric layers, Ag layers, and multiple dielectric layers. The multiple dielectric layers are layers that each contains different derivatives or layers with different composition ratios of derivatives. When two Ag layers are included, the thickness of the infrared reflective film is preferably 500 nm or less, more preferably 400 nm or less, particularly preferably 300 nm or less, and even more preferably 250 nm or less. When two Ag layers are included, the thickness of the infrared reflective film is preferably 50 nm or more, more preferably 100 nm or more, and even more preferably 150 nm or more. When three Ag layers are included, the thickness of the infrared reflective film is preferably 600 nm or less, more preferably 500 nm or less, particularly preferably 400 nm or less, and even more preferably 350 nm or less. When three Ag layers are included, the thickness of the infrared reflective film is preferably 100 nm or more, more preferably 150 nm or more, particularly preferably 200 nm or more, and even more preferably 250 nm or more.

[0061] Example

[0062] Next, embodiments of the present invention will be described.

[0063] As an example, a laminated glass sample was fabricated using the following method. Any of the following methods were used as the glass plate.

[0064] <vfl>

[0065] AGC-manufactured green glass

[0066] The VFL has a thickness of 2.0 mm. The total light transmittance of the VFL is 86%.

[0067] <fl>

[0068] AGC manufactures transparent glass.

[0069] The FL has a board thickness of 2.0 mm. The total light transmittance of the FL is 91%.

[0070] <dgl>

[0071] Privacy glass manufactured by AGC

[0072] The DGL has a thickness of 2.0 mm. The total light transmittance of the DGL is 38%.

[0073] A first layer of tone correction was formed on one surface of a glass plate (the second glass plate). In Examples 1-21, a ZrO2 layer containing Si (Si content 5% by mass: ZSO) (refractive index = 2.12 at a wavelength of 630 nm) was formed as the first layer. In Examples 22-24, a Ta2O5 layer was formed as the first layer. In Examples 25-28, a TiO2 layer was formed as the first layer.

[0074] Next, a SiO2 layer is formed on the first layer of the tone correction layer by sputtering as the second layer of the tone correction layer.

[0075] Next, an ITO layer as a transparent conductive layer is formed on the tone correction layer by sputtering. During film formation, the second glass plate is not heated. This results in an amorphous ITO layer.

[0076] Next, a SiO2 layer was formed on the ITO layer as a reflection adjustment layer by sputtering.

[0077] Then, heat the second glass plate at 650°C for 7 minutes.

[0078] Next, the first glass plate, the first intermediate film, the PDLC type dimming film, the second intermediate film, and the second glass plate are stacked together in this order to form a laminate. The PDLC type dimming film is a TGCNYO FOGLEAR GREY type (manufactured by Cloud Point Co., Ltd.). The first and second intermediate films are any of the following.

[0079] <Transparent>

[0080] S-LEC™ General-Purpose Intermediate Membrane manufactured by Sekisui Chemicals Co., Ltd.

[0081] <Gray (2%)>

[0082] S-LEC™ 7002 manufactured by Sekisui Chemicals Co., Ltd.

[0083] <Gray (5%)>

[0084] S-LEC™ 7005 manufactured by Sekisui Chemicals Co., Ltd.

[0085] <Gray (8%)>

[0086] S-LEC™ 7008 manufactured by Sekisui Chemicals Co., Ltd.

[0087] <Gray (18%)>

[0088] S-LEC™ 7018 manufactured by Sekisui Chemicals Co., Ltd.

[0089] Laminated glass samples of Examples 1 to 28 were obtained by heating the laminate to 135°C and applying pressure. Examples 1 to 3 are comparative examples, and Examples 4 to 28 are exemplary examples. The combination of the first and second glass plates, and the first and second interlayer films used in the samples of Examples 1 to 28 is shown in Table 1 below.

[0090] [Table 1]

[0091] Furthermore, the film thicknesses of each layer in the low-emissivity films of the samples in Examples 1 to 28 are shown in Table 2 below.

[0092] [Table 2]

[0093] The samples prepared in this way are measured and subjected to induction tests for evaluation.

[0094] <Measurement>

[0095] The total light transmittance was measured with the PDLC dimming film closed, according to the measurement method specified in JIS K7136. The total light transmittance was measured using a haze meter HZ-V3. The visible light reflectance on the low-emissivity film side surface of the laminated glass was measured, according to the measurement method specified in JIS R3106. The visible light reflectance was measured using a spectrophotometer U-4100 (manufactured by Hitachi High Technology Co., Ltd.). The haze value was measured with the PDLC dimming film closed, according to the measurement method specified in JIS K7136. The emissivity on the low-emissivity film side surface of the laminated glass was measured, according to the measurement method specified in JIS R1801. The emissivity was measured using a Fourier transform infrared spectrophotometer IRFressige-21 (manufactured by Shimadzu Corporation). For the haze value measurement, a haze meter HZ-V3 (manufactured by Suga Testing Machine Co., Ltd.) was used.

[0096] <Induction Test>

[0097] The following five stages were used to evaluate the hazy discomfort felt when viewing laminated glass from the indoor side with the PDLC dimming film closed.

[0098] 1: No discomfort was felt (no grainy texture could be detected)

[0099] 2: No discomfort was felt (a grainy texture could be detected)

[0100] 3: No discomfort was felt (a granular texture was clearly perceptible)

[0101] 4: I didn't feel uncomfortable, but it felt a bit unnatural.

[0102] 5: Feeling unwell

[0103] The following five stages were used to evaluate the reflection of interior decoration onto the laminated glass when the PDLC dimming film was closed and the glass was viewed from the indoor side.

[0104] 1: Unrecognized

[0105] 2: Can detect the presence of certain objects

[0106] 3: With careful observation, the interior decoration can be identified.

[0107] 4. Can normally identify interior decorations

[0108] 5: Interior trim can be clearly identified.

[0109] The glare level was evaluated by sensing the following three stages when the PDLC dimming film was turned off and the outdoor side was observed from the indoor side.

[0110] 1: It is not dazzling even when looking directly at the sun.

[0111] 2: Dazzling when looking directly at the sun, but glare is tolerable.

[0112] 3. Do not look directly at the sun; the glare must be at an unacceptable level.

[0113] The measurement results and induction test results of the samples in Examples 1 to 28 are shown in Table 3 below.

[0114] [Table 3]

[0115] The visible light reflectance of laminated glass varies with the combined film thickness of the first tone correction layer, the second tone correction layer, the transparent conductive layer, and the reflectance adjustment layer. The total light transmittance of the laminated glass with the PDLC dimming film off varies with the materials constituting the glass plate and the interlayer. As shown in Table 3, in samples 4-28, the total light transmittance of the laminated glass with the PDLC dimming film off is below 5.8%, the visible light reflectance is 0.2%–3.5%, and the haze value is above 50%. In samples 4-28, the haze discomfort is below 4, which is considered good. In samples 4-28, the reflection is below 4, which is considered good. In samples 4-28, the glare is below 2, which is considered good.

[0116] Comparison of samples in Examples 1-4 shows that when the total light transmittance of the laminated glass is below 5.8% and the visible light reflectance is above 0.2% when the PDLC dimming film is off, hazy discomfort can be suppressed. When the visible light reflectance is below 0.2%, meaning it is too low, the influence of reflected light is small when observing the surface of the low-emissivity film 16 from inside the vehicle or interior, making the graininess inherent in the PDLC dimming film directly identifiable, thus more easily causing hazy discomfort. When the visible light reflectance is above 0.2%, meaning reflected light is moderately present, the graininess of the PDLC dimming film can be moderately blocked, thus suppressing hazy discomfort. Comparison of samples in Examples 16-19 and 21 confirms that reducing visible light reflectance can further suppress reflection. Comparison of samples in Examples 3 and 16 confirms that reducing the total light transmittance of the laminated glass when the PDLC dimming film is off can further suppress glare.

[0117] The present invention has been described above with reference to the above embodiments. However, the present invention is not limited to the above embodiments. The scope of the invention of the claims in this application obviously includes various modifications, alterations and combinations that can be made by those skilled in the art.

[0118] This application claims priority based on Japanese Patent Application No. 2023-145226, filed on September 7, 2023, the entire disclosure of which is incorporated herein by reference.

[0119] Symbol Explanation

[0120] 10. Laminated glass

[0121] 11 First Glass Plate

[0122] 12 First Intermediate Membrane

[0123] 13 PDLC type dimming film

[0124] 14 Second Intermediate Membrane

[0125] 15 Second glass plate

[0126] 16, 17, 18 Low-emissivity membrane

[0127] 21 Transparent conductive layer

[0128] 22 Reflection Adjustment Layer

[0129] 23 Tone Correction Layer

[0130] 24. Adhesion Improvement Layer.< / dgl> < / fl> < / vfl>

Claims

1. A laminated glass comprising, sequentially having a first glass plate, a first interlayer film, a PDLC-type dimming film, a second interlayer film, and a second glass plate, wherein, When the PDLC dimming film is closed, the total light transmittance of the laminated glass is below 10%, and the haze value is above 50%. The second glass plate has a low-emissivity film on the surface opposite to the second intermediate film side. The visible light reflectance of the surface of the low-emissivity film on the side opposite to the second glass plate is above 0.2% and below 3.8%.

2. The laminated glass as described in claim 1, wherein, The low-emissivity film has a transparent conductive layer and a reflectance adjustment layer sequentially from the second glass plate side. The ratio of the thickness of the reflective adjustment layer to the thickness of the transparent conductive layer is greater than 0.47 and less than 0.

70.

3. A laminated glass comprising, in sequence, a first glass plate, a first interlayer film, a PDLC-type dimming film, a second interlayer film, and a second glass plate, wherein, When the PDLC dimming film is closed, the total light transmittance of the laminated glass is below 10%, and the haze value is above 50%. The second glass plate has a low-emissivity film on the surface opposite to the second intermediate film side. The low-emissivity film has a transparent conductive layer and a reflectance adjustment layer sequentially from the second glass plate side. The ratio of the thickness of the reflective adjustment layer to the thickness of the transparent conductive layer is greater than 0.47 and less than 0.

70.

4. The laminated glass as described in claim 3, wherein, The visible light reflectance of the surface of the low-emissivity film on the side opposite to the second glass plate is above 0.2% and below 3.8%.

5. The laminated glass according to any one of claims 2 to 4, wherein, The thickness of the transparent conductive layer is above 80 nm and below 160 nm.

6. The laminated glass according to any one of claims 2 to 4, wherein, The thickness of the reflection adjustment layer is above 50 nm and below 100 nm.

7. The laminated glass according to any one of claims 2 to 4, wherein, The transparent conductive layer is an ITO layer, a tin oxide layer, a fluorine-doped tin oxide layer, an antimony-doped tin oxide layer, a silver layer, a zirconium nitride layer, or a titanium nitride layer.

8. The laminated glass according to any one of claims 2 to 4, wherein, The reflection adjustment layer comprises an oxide or nitride of at least one metal selected from Ti, Nb, Ta, Zn, Al, In, Si, and Zr.

9. The laminated glass according to any one of claims 2 to 4, wherein, The low-emissivity film also has a color correction layer. The tone correction layer is composed of multiple layers, including a first layer and a second layer sequentially from the second glass plate side. The first layer has a higher refractive index for light with a wavelength of 630 nm than the second layer.

10. The laminated glass as claimed in claim 9, wherein, The first layer has a refractive index of 1.7 or higher and 2.5 or lower for light with a wavelength of 630 nm. The second layer has a refractive index of less than 1.6 for light with a wavelength of 630 nm.

11. The laminated glass according to any one of claims 2 to 4, wherein, The low-emissivity film also has a color correction layer. The hue correction layer comprises an oxide or nitride of at least one metal selected from Ti, Nb, Ta, Zn, Al, In, Si, and Zr.

12. The laminated glass according to any one of claims 2 to 4, wherein, The low-emissivity film has a hue correction layer between the surface of the second glass plate facing the low-emissivity film and the transparent conductive layer. The thickness of the tone correction layer is above 20 nm and below 60 nm.

13. The laminated glass according to any one of claims 1 to 4, wherein, The emissivity of the low-emissivity film on the surface opposite to the second glass plate is below 0.

3.

14. The laminated glass according to any one of claims 2 to 4, wherein, The low-emissivity film has an adhesion-improving layer disposed between the transparent conductive layer and the reflection adjustment layer.

15. A laminated glass for vehicles, comprising the laminated glass according to any one of claims 1 to 4.

16. A laminated glass for vehicle roof, comprising the laminated glass according to any one of claims 1 to 4.

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