Automobile window glass

Abstract

The present invention comprises: an outer glass plate having UV-absorbing capability; an inner glass plate disposed on the car interior side relative to the outer glass plate; and a resin interlayer film that bonds the outer glass plate and the inner glass plate and has at least one of UV-absorbing capability, infrared-absorbing capability, sound insulation capability, and light-dimming capability with regard to the light incident from the car exterior.

Description

Automobile window glass

[0001] The present invention relates to automobile window glass.

[0002] Automobile window glass provided on the windshield, side door, rearview mirror, roof, etc. generally needs to cut ultraviolet rays contained in sunlight incident from outside the vehicle. As a method, for example, it has been proposed to arrange an ultraviolet absorber in the interlayer film of laminated glass (for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2016-64965

[0004] However, since the interlayer film is generally formed of an organic polymer material, it may be yellowed by ultraviolet rays, or if the interlayer film contains a functional layer, its function may deteriorate. In particular, an interlayer film containing an ultraviolet absorber may be inferior in light resistance to ultraviolet rays because it absorbs ultraviolet rays.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide an automobile window glass capable of suppressing deterioration of the interlayer film due to ultraviolet rays.

[0006] Item 1. An outer glass plate having ultraviolet absorption performance, an inner glass plate provided on the inner side of the vehicle with respect to the outer glass plate, and a resin interlayer film that adheres the outer glass plate and the inner glass plate and has at least one of ultraviolet absorption performance, infrared absorption performance, sound insulation performance, and light control performance for light incident from outside the vehicle. An automobile window glass provided with

[0007] Item 2. The automobile window glass according to Item 1, wherein the Tuv (ISO9050-2003) of the outer glass plate is 40.0% or less.

[0008] Item 3. The automobile window glass according to Item 1, wherein the Tuv (ISO9050-2003) of the outer glass plate is 30.0% or less.

[0009] Item 4. The automobile window glass according to any one of Items 1 to 3, wherein the chromaticity b* in the CIE standard is 3.0 or less.

[0010] Item 5. Automotive window glass as described in any of items 1 to 3, having a CIE standard chromaticity b* of 1.5 or less.

[0011] Item 6. Automotive window glass according to any one of items 1 to 5, wherein the visible light transmittance YA, measured in accordance with JIS R3106:1998 using a CIE standard A light source, is 70.5% or more and 74.0% or more.

[0012] Item 7. Automotive window glass according to any one of items 1 to 5, wherein the visible light transmittance YA, measured in accordance with JIS R3106:1998 using a CIE standard A light source, is 71.5% or more and 74.0% or less.

[0013] Item 8. The automobile window glass according to any one of items 1 to 7, wherein the Fe2O3 content in the outer glass plate is higher than the Fe2O3 content in the inner glass plate, and the average of the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.6% by mass or more.

[0014] Item 9. The automobile window glass according to Item 8, wherein the difference between the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.15% by mass or more.

[0015] Item 10. The automobile window glass according to Item 8, wherein the difference between the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.25% by mass or more.

[0016] Item 11. The outer glass plate contains, as a base composition, t-Fe2O3: 0.60% by mass or more and 0.90% by mass or less, Fe2O3: 0.50% by mass or more and 0.60% by mass or less, Al2O3: 1.2% by mass or more and 3.0% by mass or less, CeO2: 0.4% by mass or less, and TiO2: 0.07% by mass or less, and the FeO ratio, expressed as the mass ratio of FeO to T-Fe2O3 converted to Fe2O3, is 26% or more and 30% or less, according to any one of items 1 to 10.

[0017] Item 12. The outer glass plate contains, as a base composition, t-Fe2O3: 0.60% by mass or more and 0.90% by mass or less, Fe2O3: 0.60% by mass or more and 0.70% by mass or less, Al2O3: 1.2% by mass or more and 3.0% by mass or less, CeO2: 0.8% by mass or less, and TiO2: 0.15% by mass or less, and the FeO ratio, expressed as the mass ratio of FeO to T-Fe2O3 converted to Fe2O3, is 22% or more and 28% or less, according to any one of items 1 to 10.

[0018] Item 13. Automotive window glass according to any one of items 1 to 12, wherein the Al2O3 content in the outer glass plate is 0.6% by mass or more higher than the Al2O3 content in the inner glass plate.

[0019] Item 14. A windshield using the automotive window glass described in any of items 1 to 13.

[0020] Item 15. A side window using the automotive window glass described in any of items 1 to 13.

[0021] Item 16. A roof window using any of the automotive window glass described in items 1 to 13.

[0022] Item 17. The roof window according to Item 16, wherein the difference between the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.60% by mass or more.

[0023] Item 18. The roof window according to item 16 or 17, wherein the interlayer comprises a light-adjusting layer capable of switching linear transmittance.

[0024] Item 19. The roof window according to Item 18, wherein the light-adjusting layer is a PDLC layer in which liquid crystals are dispersed in a polymer material.

[0025] Item 20. The roof window according to any one of items 16 to 18, wherein a LowE film is laminated on the inner glass plate.

[0026] According to the present invention, it is possible to suppress the degradation of the interlayer due to ultraviolet light.

[0027] This is a plan view showing one embodiment in which the automotive window glass according to the present invention is applied to a windshield. This is a cross-sectional view of Figure 1. This is a block diagram showing the schematic configuration of an in-vehicle system.

[0028] Hereinafter, an embodiment of the application of the automotive window glass according to the present invention to a windshield will be described with reference to the drawings. Figure 1 is a plan view of the windshield, and Figure 2 is a cross-sectional view of Figure 1. For the sake of convenience in the explanation, the vertical direction in Figure 1 will be referred to as "up and down," "vertical," or "vertical," and the left and right direction in Figure 1 will be referred to as "left and right." Figure 1 illustrates the windshield as seen from the inside of the vehicle. That is, the far side of Figure 1 is the outside of the vehicle, and the near side of Figure 1 is the inside of the vehicle.

[0029] This windshield is equipped with a trapezoidal laminated glass 10 and is installed on the vehicle body in an inclined position. The laminated glass 10 has an outer glass plate 11, an inner glass plate 12, and an interlayer 13 placed between them. A shielding layer 4 is laminated on the in-vehicle side surface of the inner glass plate 12, and this shielding layer 4 blocks the view from outside the vehicle. An opening 43 is formed in this shielding layer 4, and through this opening 43, the outside situation can be photographed by a camera 2 placed inside the vehicle. In other words, this opening 43 constitutes a camera window. Furthermore, a frame-shaped bracket 6 is fixed on the shielding layer 4 of the inner glass plate 12, and the camera 2 is attached to this bracket 6. Since the bracket 6 is formed in a frame shape and fixed on the shielding layer 4, the bracket 6 is not visible from outside the vehicle. The following describes each component in detail.

[0030] <1. Laminated Glass> Figure 2 is a cross-sectional view of laminated glass. As shown in the figure, this laminated glass 10 comprises an outer glass plate 11 and an inner glass plate 12, with a resin interlayer 13 placed between these glass plates 11 and 12. The following describes these components.

[0031] <1-1. Glass Plates> First, the outer glass plate 11 and the inner glass plate 12 will be explained. The outer glass plate 11 and the inner glass plate 12 can be made of, for example, heat-absorbing glass, clear glass, green glass, or UV green glass. Specifically, they can be made of glass plates having the following compositions.

[0032] As will be described later, the interlayer 13 formed of resin material may deteriorate due to ultraviolet rays incident from outside the vehicle; therefore, the outer glass plate 11 of this embodiment has ultraviolet absorbing properties. For this reason, for example, the Tuv (ISO 9050-2003) of the outer glass plate 11 is preferably 40.0% or less, and more preferably 30.0% or less.

[0033] To reduce Tuv, it is preferable to have a higher total iron oxide content (t-Fe2O3) in the outer glass plate 11, converted to Fe2O3. The t-Fe2O3 content is preferably 0.7% by mass or more, more preferably 0.8% by mass or more, and particularly preferably 0.85% by mass or more. Among these, to reduce Tuv, it is especially preferable that the Fe2O3 content be 0.50% by mass or more, and more preferably 0.50% by mass or more.

[0034] Furthermore, the inventors have confirmed that the Al2O3 content in the glass plates 11 and 12 also contributes to reducing Tuv. The Al2O3 content is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, and particularly preferably 2.0% by mass or more. The upper limit of the Al2O3 content is preferably 3.0% by mass. For example, even if the Fe2O3 content is the same, a higher Al2O3 content can reduce Tuv.

[0035] Furthermore, the glass plates 11 and 12 may contain TiO2 and CeO2, and a higher content of these can reduce Tuv. The TiO2 content is preferably, for example, 0.05% by mass or more, and more preferably 0.10% by mass or more. The CeO2 content is preferably, for example, 0.3% by mass or more, and more preferably 0.5% by mass or more.

[0036] However, if the Fe2O3 and Al2O3 content is high, the visible light transmittance will decrease. Therefore, as will be described later, depending on the combination of the outer glass plate 11 and the inner glass plate 12 when constructing laminated glass, the installation location of the window glass will be limited.

[0037] Furthermore, a higher content of Fe2O3 and Al2O3 results in a higher CIE standard chromaticity b*. For example, a higher chromaticity b* makes the glass appear yellowish, while a lower chromaticity b* makes the glass appear bluish. Since bluish tints are generally preferred for automotive windows, a lower chromaticity b* is preferable from this perspective, and therefore, a low content of Fe2O3 and Al2O3 is desirable. Such color adjustment can also be achieved by adjusting the content of TiO2 and CeO2. For example, a lower content of TiO2 and CeO2 can lower the chromaticity b*.

[0038] Furthermore, if the FeO content in the glass plates 11 and 12 is high, the infrared absorption performance will be high and the chromaticity b* will be low. Therefore, in order to lower the chromaticity b*, for example, if the total iron oxide content converted to Fe2O3 is taken as t-Fe2O3, the FeO ratio, which is expressed as the mass ratio of FeO to t-Fe2O3, is preferably 26% or more and 30%, and more preferably 28% or more and 30%. On the other hand, in order to increase the chromaticity b*, for example, if the total iron oxide content converted to Fe2O3 is taken as t-Fe2O3, the FeO ratio, which is expressed as the mass ratio of FeO to t-Fe2O3, is preferably 22% or more and 26%, and more preferably 22% or more and 25%.

[0039] Based on the above, in order to increase the ultraviolet absorption performance of the outer glass plate 11, for example, the following composition can be used. (Example 1) The base composition contains: t-Fe2O3, which is the total iron oxide content converted to Fe2O3: 0.50% by mass or more and 0.90% by mass or less (preferably 0.6% by mass or more and 0.9% by mass or less, more preferably 0.8% by mass or more and 0.9% by mass or less), Fe2O3: 0.36% by mass or more and 0.70% by mass or less (preferably 0.50% by mass or more and 0.70% by mass or less, more preferably 0.6% by mass or more and 0.70% by mass or less), Al2O3: 1.2% by mass or more and 3.0% by mass or less (preferably 1.5% by mass or more and 3.0% by mass or less, more preferably 1.8% by mass or more and 3.0% by mass or less), CeO2: 0.8% by mass or less (including 0% by mass, i.e., not contained), TiO2: 0.15% by mass or less (including 0% by mass, i.e., not contained), The FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 22% or more and 28% or less (preferably 22% or more and 26% or less).

[0040] On the other hand, the outer glass plate 11 does not have very high ultraviolet absorption performance, but in order to increase the visible light transmittance and lower the chromaticity b*, it can be composed as follows, for example. (Example 2) The base composition contains: t-Fe2O3, which is the total iron oxide content converted to Fe2O3: 0.60% by mass or more and 0.90% by mass or less (preferably 0.6% by mass or more and 0.8% by mass or less), Fe2O3: 0.42% by mass or more and 0.67% by mass or less (preferably 0.50% by mass or more and 0.60% by mass or less), Al2O3: % by mass or more and 3.0% by mass or less (preferably 1.2% by mass or more and 3.0% by mass or less), CeO2: 0.4% by mass or less (including 0% by mass, i.e., not contained), TiO2: 0.07% by mass or less (including 0% by mass, i.e., not contained), and the FeO ratio, which is expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 26% or more and 30% or less (preferably 28% or more and 30% or less).

[0041] As an outer glass plate 11, although its ultraviolet absorption performance is not very high, in order to further increase the visible light transmittance and further decrease the chromaticity b*, the following composition can be used, for example. (Example 3) The base composition contains: t-Fe2O3, which is the total iron oxide content converted to Fe2O3: 0.08% by mass or more and less than 0.30% by mass; Fe2O3: 0.08% by mass or more and 0.45% by mass or less (preferably 0.30% by mass or more and 0.45% by mass or less); Al2O3: 0% by mass or more and 3.0% by mass or less (preferably 1.2% by mass or more and 3.0% by mass or less); CeO2: 0.1% by mass or less (including 0% by mass, i.e., not contained); TiO2: 0.05% by mass or less (including 0% by mass, i.e., not contained); and the FeO ratio, which is expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 25% or more and 30% or less (preferably 28% or more and 30% or less).

[0042] To achieve high ultraviolet absorption performance and low visible light transmittance as the outer glass plate 11, the composition can be as follows, for example: (Example 4) - The total iron oxide content, t-Fe2O3 and TiO2, converted to Fe2O3, is 1.0% by mass or more and 4.0% by mass or less, - Co3O4 is 500 ppm or less, - Se is 15 ppm or more and 40 ppm or less, - The FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 20% by mass or more and 30% by mass or less

[0043] For example, by combining glass plates such as those in Examples 1 to 4 described above, laminated glass with various properties can be formed. In order to suppress the deterioration of the interlayer due to ultraviolet rays as described above, it is preferable to use the glass plate of Example 1 or Example 2 as the outer glass plate. The composition of the outer glass plate 11 described above can also be applied to the inner glass plate 12. Furthermore, although the glass of Example 4 has a low visible light transmittance, it has high ultraviolet absorption performance, so it is preferable to use it as a roof window.

[0044] The thickness of the laminated glass 10 according to the present embodiment is not particularly limited, but the total thickness of the outer glass plate 11 and the inner glass plate 12 can be, for example, 2.1 to 6 mm. From the viewpoint of weight reduction, it is preferable that the total thickness of the outer glass plate 11 and the inner glass plate 12 is 2.4 to 5.0 mm, more preferably 2.6 to 4.0 mm, and particularly preferably 2.7 to 3.2 mm. Thus, in order to reduce the weight, it is necessary to reduce the total thickness of the outer glass plate 11 and the inner glass plate 12. Therefore, the thickness of each glass plate is not particularly limited, but for example, the thickness of the outer glass plate 11 and the inner glass plate 12 can be determined as follows.

[0045] The outer glass plate 11 mainly requires durability and impact resistance against external obstacles. As an automobile windshield, impact resistance performance against flying objects such as small stones is required. On the other hand, the greater the thickness, the greater the weight, which is not preferable. From this viewpoint, the thickness of the outer glass plate 11 is preferably 1.8 to 2.3 mm, and more preferably 1.9 to 2.1 mm. Which thickness to adopt can be determined according to the use of the glass.

[0046] The thickness of the inner glass plate 12 can be the same as that of the outer glass plate 11. However, for example, in order to reduce the weight of the laminated glass 10, the thickness can be made smaller than that of the outer glass plate 11. Specifically, considering the strength of the glass, it is preferably 0.6 to 2.0 mm, preferably 0.8 to 1.6 mm, and particularly preferably 1.0 to 1.4 mm. Furthermore, it is preferably 0.8 to 1.3 mm. Regarding the inner glass plate 12 as well, which thickness to adopt can be determined according to the use of the glass.

[0047] Also, a Low-E film can be laminated on the surface of each glass plate. In particular, the Low-E film is preferably laminated on the inner surface of the glass plate, and further preferably on the inner surface of the inner glass plate 12. A clear glass laminated with such a Low-E film can be preferably used. An example of a clear glass on which it is preferable to laminate a Low-E film is shown below.

[0048] (Clear glass) - SiO₂: 70 - 73% by mass, - Al₂O₃: 0.6 - 2.4% by mass, - CaO: 7 - 12% by mass, - MgO: 1.0 - 4.5% by mass, - R₂O: 13 - 15% by mass (R is an alkali metal), - Total iron oxide (T - Fe₂O₃) converted to Fe₂O₃: 0.08 - 0.14% by mass

[0049] The Low - E film is not particularly limited as long as it does not inhibit the object of the present invention. Preferably, it is a multilayer film including a layer mainly composed of silver. Also, the Low - E film preferably consists of a multilayer formed by laminating two or more kinds of layers selected from a metal layer, a metal oxide layer, a metal nitride layer, and a metal oxynitride layer. A preferred example of the metal layer is a silver layer. Preferred examples of the metal oxide layer include a tin oxide layer, a titanium oxide layer, or a zinc oxide layer. A preferred example of the metal nitride layer is silicon nitride. A preferred example of the metal oxynitride layer is silicon oxynitride. The Low - E film 41 is preferably formed by a vacuum film - forming method such as physical vapor deposition (PVD). In particular, the sputtering method is preferred because it can form a film of a large area uniformly. For example, the Low - E film is formed on a glass plate by the sputtering method.

[0050] Also, the Low - E film more preferably consists of a multilayer formed by laminating three or more kinds of layers selected from a tin oxide layer, a silicon nitride layer, a silicon oxynitride layer, a titanium oxide layer, a zinc oxide layer, and a silver layer. Sequentially from the surface of the glass plate, (1) a tin oxide layer (first antireflection layer), a zinc oxide layer (first antireflection layer), a silver layer (metal layer), a zinc oxide layer (second antireflection layer), and a tin oxide layer (second antireflection layer), (2) a silicon nitride layer (first antireflection layer), a zinc oxide layer (first antireflection layer), a silver layer (metal layer), and a zinc oxide layer (second antireflection layer) laminated to form a three - layer or five - layer structure is most preferred.

[0051] The Low-E film contains a metal layer mainly composed of silver. The thickness of the metal layer is preferably 5 nm to 20 nm, and more preferably 10 nm to 15 nm. By having a metal layer of a predetermined thickness mainly composed of silver in the Low-E film, heat radiation can be suppressed. As a result, the thermal insulation performance of the inner glass plate 12 can be improved. Furthermore, by having a metal layer thickness of 15 nm or less, the visual impact of the Low-E film can be minimized.

[0052] Here, we will describe an example of a method for measuring the thickness of a curved glass plate (laminated glass) 1. First, the measurement positions are two locations, one above and one below, on the center line S that extends vertically from the center of the glass plate in the left-right direction. The measuring instrument is not particularly limited, but for example, a thickness gauge such as the SM-112 manufactured by Teclock Co., Ltd. can be used. When measuring, the curved surface of the glass plate is placed on a flat surface, and the edge of the glass plate is clamped with the thickness gauge and measured. Note that even if the glass plate is flat, it can be measured in the same way as when it is curved.

[0053] <1-2. Interlayer> As shown in Figure 2, the interlayer 13 comprises a transparent first adhesive layer 131 that is bonded to the outer glass plate 11, a transparent second adhesive layer 132 that is bonded to the inner glass plate 12, and a transparent functional layer 133 that is placed between these two adhesive layers 131 and 132.

[0054] The first adhesive layer 131 and the second adhesive layer 132 can be made of materials that do not affect the light (visible light) incident on the camera when taking images with the imaging device 2, and that allow light to pass through. In other words, as will be described later, the materials of the two adhesive layers 131 and 132 are selected so that the image captured by the camera, which is formed by the light passing through both adhesive layers 131 and 132, is hardly affected by distortion or other influences from the two adhesive layers 131 and 132. The two adhesive layers 131 and 132 are bonded to each glass plate 11 and 12 by fusion, and can be formed from, for example, polyvinyl butyral resin (PVB) or ethylene vinyl acetate resin (EVA). In general, the hardness of polyvinyl acetal resin can be controlled by (a) the degree of polymerization of the starting material, polyvinyl alcohol, (b) the degree of acetalization, (c) the type of plasticizer, and (d) the proportion of plasticizer added.

[0055] At least one of the adhesive layers 131, 132 may contain, for example, oxide fine particles (infrared absorbers) having a heat-cutting function. Suitable oxide fine particles include tin-doped indium oxide (ITO), antimond-doped tin oxide (ATO), and aluminum-doped zinc oxide (AZO). The content of these oxide fine particles is preferably 0.13 to 3.0 parts by weight per 100 parts by weight of the polyvinyl acetal resin constituting either adhesive layer 131, 132. At least one of the adhesive layers 131, 132 may also contain an ultraviolet absorber for absorbing ultraviolet rays. In particular, since the light-adjusting film described later is prone to degradation by ultraviolet rays, it is preferable to include an ultraviolet absorber. It is preferable that such infrared absorbers and ultraviolet absorbers are contained in the first adhesive layer 131. Furthermore, since such infrared absorbers and ultraviolet absorbers are prone to degradation by ultraviolet rays, it is preferable that the outer glass plate 11 has high ultraviolet absorption performance when using them.

[0056] Examples of UV absorbers that can be used include compounds having a malonic acid ester skeleton, compounds having an oxalic acid anilide skeleton, compounds having a benzotriazole skeleton, compounds having a benzophenone skeleton, compounds having a triazine skeleton, compounds having a benzoate skeleton, and compounds having a hindered amine skeleton. Among these, compounds having a benzotriazole skeleton (benzotriazole compounds) are preferred.

[0057] Specific examples of UV absorbers used in interlayers include the following: Benzotriazole type (1): Tinuvin 326, a compound represented by the following formula (1), where X is a chlorine atom, R21 is a methyl group, R22 is a tert-butyl group, Y1 is a hydrogen atom, and Y2 is a hydroxyl group. Trade name "Tinuvin 326", manufactured by Ciba Specialty Chemicals. Benzotriazole type (2): 2-(2,4-dihydroxyphenyl)-2H-benzotriazole

[0058] Before bonding to each glass plate 11, 12, the first adhesive layer 131 and the second adhesive layer 132 may be embossed on their surfaces to facilitate the expulsion of air when bonding to the functional layer 133 or to each glass plate 11, 12.

[0059] The thickness of the first adhesive layer 131 and the second adhesive layer 132 is not particularly limited, but is preferably 20 μm to 2.0 mm, more preferably 20 μm to 1.0 mm, and particularly preferably 50 to 100 μm. However, the thicknesses of both adhesive layers 131 and 132 may be the same or different. Furthermore, if an emboss is formed on each adhesive layer 131 and 132, it is preferable to set the thickness to 20 μm or more, taking into account the depth of the emboss, as described above. Alternatively, instead of using a sheet-like adhesive layer, the adhesive layers 131 and 132 can be formed by coating. In this case, a thin adhesive layer of 0.3 to 100 μm can be formed.

[0060] Furthermore, it is preferable that the combined thickness of both adhesive layers 131 and 132 be 0.76 mm or more. This is to ensure, for example, penetration resistance and other performance specified in JIS R3211 and R3212 for the windshield.

[0061] As the functional layer 133, various films with different functions can be used depending on the application. For example, known heat-shielding films, heat-generating films, projection films, light-emitting films, antenna films, and dimming films can be used.

[0062] To suppress the rise in temperature inside the vehicle, the heat-shielding film can employ a known infrared-reflective film that reflects infrared rays, or a film configured to absorb infrared rays. It is preferable that such a heat-shielding film be positioned on the outer glass plate 11 side in the thickness direction of the interlayer 13. That is, the first adhesive layer 131 should be thinner than the second adhesive layer 132. In this way, infrared rays can be reflected or absorbed at a position further away from the inside of the vehicle in the laminated glass. In addition to using a heat-shielding film for the functional layer 133, to provide a heat-shielding function, for example, at least one of the first adhesive layer 131 and the second adhesive layer 132 can be formed of heat-shielding PVB.

[0063] The heating film is used to remove condensation or de-icing, and can consist of multiple fine wires that generate heat when a voltage is applied, supported by a base film. The base film can be any film that is transparent to visible light, and its material is not particularly limited, but it can be made of, for example, polyethylene terephthalate, polyethylene, polymethyl methacrylate, polyvinyl chloride, polyester, polyolefin, polycarbonate, polystyrene, polypropylene, nylon, etc. In addition to generating heat with fine wires, a transparent conductive film heater composed of, for example, a thin-film silver heater or an ITO heater can also be used.

[0064] The projection film is onto which information is projected by light emitted from a head-up display device (hereinafter referred to as HUD). The projection film is not particularly limited as long as it is a film that reflects light and has a different refractive index from the two adhesive layers 131 and 132, for example, a film whose polarization can be controlled, such as a p-polarizing reflective film, a hologram film, a transparent screen with a scattering reflective system, a transparent screen with a scattering transmission system, a dimmable film with a scattering reflective system, a dimmable film with a scattering transmission system, or a dimmable film for HUDs. The size of the projection film is not particularly limited, but it is preferably larger than the area on which the information is projected. The projection film may also be supported by a base film. The base film can be the same as the one used for the heat-generating film described above. The projection film may also be the same size as the base film, or it may be smaller than the base film. In this case, it is preferable that the outer edge of the projection film is located inward from the outer edge of the base film.

[0065] Furthermore, the base film can be placed on either the outer glass plate 11 side or the inner glass plate 12 side of the projection film. Alternatively, the projection film can be sandwiched between two base films.

[0066] The light-emitting film has built-in LEDs or similar elements that emit light to display predetermined characters, shapes, or other designs.

[0067] Antenna films, like heating films, are films on which antennas such as FM, AM, DTV, and DAB are arranged on the aforementioned base film.

[0068] A dimmable film (dimmable layer) is a film that can change the visibility from outside the vehicle by switching its linear transmittance. Various types of dimmable films have been proposed, but for example, one can control the haze rate of the film by the presence or absence of electricity, creating a transparent state and an opaque state. In other words, it is a functional film that can provide privacy. For example, known types such as PDLC (Polymer Dispersed Liquid Crystal) type, SPD (Suspended Particle Device) type, electrochromic type, and thermochromic type can be used. For example, a PDLC type dimmable film can be composed of a liquid crystal layer, a pair of transparent conductive films sandwiching this liquid crystal layer, and a PET film placed on the outer surface of each transparent conductive film. The liquid crystal layer has a liquid crystal capsule formed by encapsulating a transparent polymer film and liquid crystal. Dimmable films are suitably used for roof windows.

[0069] The above is merely an example of the functional layer 133, and at least one of the above can be used. Furthermore, other functional layers may also be used, and the system is not particularly limited.

[0070] The thickness of the film constituting the functional layer 133 described above is not particularly limited, but is preferably 50 to 600 μm, more preferably 50 to 500 μm, and particularly preferably 50 to 100 μm.

[0071] Furthermore, the functional layer 133 has a rectangular through-hole (transparent region) 130 formed therein, which is positioned to correspond to the opening 43 of the shielding layer 4, which will be described later. More specifically, as shown in Figures 1 and 2, the outer edge of this through-hole 130 is located outside the outer edge of the opening 43 of the shielding layer 4, but inside the outer edge of the extended portion 42 of the shielding layer 4.

[0072] The thickness of each adhesive layer 131, 132 and functional layer 133 can be measured, for example, as follows. First, the cross-section of the windshield is magnified 175 times using a microscope (for example, a VH-5500 manufactured by Keyence Corporation) and displayed. Then, the thickness of each adhesive layer 131, 132 and functional layer 133 is identified visually and measured. In this case, in order to eliminate visual variation, the measurement is taken five times, and the average value is taken as the thickness of each adhesive layer 131, 132 and functional layer 133.

[0073] The size of each adhesive layer 131, 132 is the same as that of the outer glass plate 11 and the inner glass plate 12, but the size of the functional layer 133 can be the same as or smaller than that of both adhesive layers 131, 132. For example, the periphery of the functional layer 133 can be positioned inward from the periphery of each glass plate 11, 12, and in particular, it can be positioned so as to be hidden by the periphery 41 of the shielding layer 4, which will be described later.

[0074] The method for manufacturing the interlayer 13 is not particularly limited, but examples include a method in which a resin component such as the polyvinyl acetal resin mentioned above, a plasticizer, and other additives as needed are blended and kneaded uniformly, and then each layer is extruded and molded all at once, or a method in which two or more resin films created by this method are laminated by a pressing method, a laminating method, etc. The resin film used in the lamination method by pressing method, a laminating method, etc., before lamination may have a single-layer structure or a multi-layer structure. In addition, the interlayer 13 can be formed as a single layer, as well as as multiple layers as described above.

[0075] <1-3. Physical Properties of Laminated Glass> Next, preferred physical properties of laminated glass will be described. (1) Visible Light Transmittance YA In order to use laminated glass as a windshield or side window, the YA must be 70% or more (Article 39, Paragraph 3, Item 7 of the Notification Specifying the Details of Safety Standards for Road Vehicles), preferably 70.5% or more, and more preferably 71.5% or more. However, if the YA is too high, the ultraviolet absorption performance may decrease depending on the combination of glass plates, so it is preferable to have a YA of 74.0% or less, and more preferably 73.0% or less. To achieve this, for example, a glass plate like at least one of Example 2 or Example 3 described above can be used as either the outer glass plate 11 or the inner glass plate 12. For example, both glass plates 11 and 12 can be made of the glass plate of Example 2. Alternatively, the outer glass plate can be made of the glass plate of Example 1 or Example 2, and the inner glass plate can be made of the glass plate of Example 2 or Example 3. In general, there are no restrictions on the YA (Yield Absorption) when laminated glass is used for purposes other than windshields or side windows. Therefore, laminated glass with a YA of less than 72% can be used, for example, for roof windows, rear windows, etc. In this case, for example, glass plates like those in Examples 1 to 3 described above can be used as the outer or inner glass plate. For example, both glass plates 11 and 12 can be made from the glass plate of Example 1.

[0076] (2) CIE standard chromaticity b* As described above, since a bluish color is preferred for automotive window glass, the chromaticity b* is preferably 3.0 or less, and more preferably 1.5 or less. To achieve this, for example, a glass plate like at least one of Example 2 or Example 3 described above can be used as either the outer glass plate 11 or the inner glass plate 12.

[0077] (3) Fe2O3 content From the viewpoint of ultraviolet absorption performance, a higher Fe2O3 content is preferable, so it is preferable that the average Fe2O3 content of the outer glass plate 11 and the inner glass plate 12 is 0.45% by mass or more.

[0078] Furthermore, to prevent deterioration of the interlayer 13, the ultraviolet absorption performance of the outer glass plate 11 has a significant impact, so it is preferable that the Fe2O3 content of the outer glass plate 11 is higher than that of the inner glass plate 12. This is because if the Fe2O3 content of both glass plates 11 and 12 is high, the YA of the window glass may increase. Therefore, in order to obtain a good balance between ultraviolet absorption performance (interlayer deterioration suppression performance) and visible light transmittance, it is preferable that the difference between the Fe2O3 content of the outer glass plate 11 and the Fe2O3 content of the inner glass plate 12 be large. For example, it is preferable that this difference be 0.10% by mass or more, more preferably 0.18% by mass or more, and particularly preferably 0.25% by mass or more. To achieve this, glass plates such as those in Examples 1 to 4 described above can be appropriately combined.

[0079] (4) Al2O3 content From the viewpoint of ultraviolet absorption performance, it is preferable that the Al2O3 content be high, as described above. Therefore, it is preferable that the Al2O3 content in the outer glass plate 11 is higher than the Al2O3 content in the inner glass plate 12, for example, that the difference between the two is 0.6% by mass or more. To achieve this, glass plates such as those in Examples 1 to 3 described above can be appropriately combined.

[0080] <1-4. Others> Various functional films can be laminated onto the interior surface of the inner glass plate 12, for example, a LowE film can be laminated. Also, if you want to improve the ultraviolet absorption performance, you can laminate an ultraviolet absorbing film onto the exterior surface of the outer glass plate 11. For example, if both glass plates 11 and 12 are made of the glass plates of Example 3, or if the outer glass plate is made of the glass plate of Example 2 and the inner glass plate 12 is made of the glass plate of Example 3, you can laminate an ultraviolet absorbing film if you want to further improve the ultraviolet absorption performance.

[0081] <2. Overview of the Shielding Layer> Next, the shielding layer 4 will be described. As shown in Figure 1, the shielding layer 4 is laminated on the interior surface of the outer glass plate 11 and on the interior surface of the inner glass plate 12. Since the shielding layer 4 laminated on each of these surfaces has the same shape, the shielding layer 4 laminated on the inner glass plate 12 will be described below. More specifically, this shielding layer 4 comprises a peripheral portion 41 that is laminated along the entire circumference of the periphery of the inner glass plate 12, and a rectangular extension portion 42 that is connected to the peripheral portion 41 and extends downward from near the center of the upper edge of the inner glass plate 12. A trapezoidal opening 43 is formed at the lower end of the extension portion 42, and the photographing device 2 installed on the interior side of the vehicle can photograph the outside of the vehicle through this opening 43 and the laminated glass 10.

[0082] As shown in Figure 2, the bracket 6 described above is fixed onto the shielding layer 4. Specifically, the bracket 6 is formed in a frame shape that surrounds the opening and is fixed to the shielding layer 4 with double-sided tape, adhesive, etc. The camera device 2 is supported by this bracket 6 and is configured to photograph the outside of the vehicle through the opening 43. Although not shown in the figure, a cover is attached to the bracket 6 so that the camera device 2 is not visible from inside the vehicle.

[0083] Next, the material of the shielding layer 4 will be described. The material of the shielding layer 4 may be appropriately selected according to the embodiment, as long as it can block the view from outside the vehicle. For example, dark-colored ceramics such as black, brown, gray, or dark blue may be used.

[0084] If black ceramic is selected as the material for the shielding layer 4, for example, black ceramic is laminated onto the inner surface of the inner glass plate 12 by screen printing or the like, and the ceramic laminated together with each glass plate 11, 12 is heated. When the ceramic hardens, the shielding layer 4 is completed. Various materials can be used for the ceramic used in each shielding layer 4. For example, ceramics with the compositions shown in Table 1 below can be used for the shielding layer 4.

[0085] *1 Main components: copper oxide, chromium oxide, iron oxide, and manganese oxide *2 Main components: bismuth borosilicate, zinc borosilicate

[0086] In the example above, the shielding layer 4 is laminated on the inner surface of the outer glass plate 11 and the inner surface of the inner glass plate 12. However, for example, the shielding layer 4 can also be laminated only on the inner surface of the inner glass plate 12. Alternatively, the shielding layer 4 can also be laminated only on the inner surface of the outer glass plate 11.

[0087] <3. In-vehicle system> Next, an in-vehicle system comprising a camera 2 and an image processing device 3 will be described using Figures 2 and 3. Figure 3 illustrates the configuration of the in-vehicle system. As illustrated in Figure 3, the in-vehicle system according to this embodiment comprises the camera 2 and an image processing device 3 connected to the camera 2.

[0088] The image processing device 3 is a device that processes images acquired by the imaging device 2. For example, the image processing device 3 has a general hardware configuration, such as a storage unit 31, a control unit 32, and an input / output unit 33, all connected by a bus. However, the hardware configuration of the image processing device 3 is not limited to this example, and the specific hardware configuration of the image processing device 3 can be appropriately modified, with components being added, omitted, or added as appropriate, depending on the embodiment.

[0089] The storage unit 31 stores various data and programs used in the processing performed by the control unit 32 (not shown). The storage unit 31 may be implemented by, for example, a hard disk or by a recording medium such as a USB memory. Furthermore, the various data and programs stored in the storage unit 31 may be obtained from a recording medium such as a CD (Compact Disc) or DVD (Digital Versatile Disc). In addition, the storage unit 31 may also be called an auxiliary storage device.

[0090] As described above, the laminated glass 10 is positioned at an inclined angle to the vertical and is curved. The imaging device 2 then photographs the situation outside the vehicle through such laminated glass 10. Therefore, the images acquired by the imaging device 2 are deformed according to the orientation, shape, refractive index, optical defects, etc. of the laminated glass 10. In addition, aberrations inherent to the camera lens of the imaging device 2 are also added. Therefore, the memory unit 31 may store correction data for correcting images deformed by such aberrations of the laminated glass 10 and the camera lens.

[0091] The control unit 32 includes one or more processors, such as a microprocessor or CPU (Central Processing Unit), and peripheral circuits (ROM (Read Only Memory), RAM (Random Access Memory), interface circuits, etc.) used for processing by this processor. The ROM, RAM, etc. may also be called main memory in the sense that they are located in the address space handled by the processor within the control unit 32. The control unit 32 functions as an image processing unit 321 by executing various data and programs stored in the storage unit 31.

[0092] The image processing unit 321 processes the captured image acquired by the shooting device 2. The processing of the captured image can be appropriately selected depending on the embodiment. For example, the image processing unit 321 may recognize subjects in the captured image by analyzing the image using pattern matching or the like. In this embodiment, since the shooting device 2 captures the situation in front of the vehicle, the image processing unit 321 may further determine, based on the subject recognition, whether or not there are living beings such as humans in front of the vehicle. If a person is captured in front of the vehicle, the image processing unit 321 may output a warning message in a predetermined manner. Alternatively, for example, the image processing unit 321 may apply a predetermined processing to the captured image. The image processing unit 321 may then output the processed captured image to a display device (not shown), such as a display connected to the image processing device 3.

[0093] The input / output unit 33 is one or more interfaces for sending and receiving data with devices located outside the image processing device 3. The input / output unit 33 is, for example, an interface for connecting to a user interface, or an interface such as USB (Universal Serial Bus). In this embodiment, the image processing device 3 connects to the imaging device 2 via the input / output unit 33 and acquires images captured by the imaging device 2.

[0094] Such an image processing device 3 may be a device specifically designed for the service being provided, or it may be a general-purpose device such as a PC (Personal Computer) or a tablet terminal.

[0095] Furthermore, as described above, the imaging device 2 is attached to the bracket 6. Therefore, in this state, the attachment of the imaging device 2 to the bracket 6 and the attachment of the bracket to the first shielding layer 4 are adjusted so that the optical axis of the camera lens of the imaging device 2 passes through the opening 43. A cover, not shown in the illustration, is attached to the bracket 6 so as to cover the imaging device 2. Thus, the imaging device 2 is placed in a space enclosed by the laminated glass 10, the bracket, and the cover, so as not to be seen from inside the vehicle, and from outside the vehicle, only a part of the imaging device 2 is visible through the opening 43 by the first and second shielding layers 4 and 5. The imaging device 2 and the input / output unit 33 described above are connected by a cable, not shown in the illustration, which is pulled out from the cover and connected to the image processing device 3 located at a predetermined position inside the vehicle.

[0096] <4. Method for Manufacturing a Windshield> Next, an example of a method for manufacturing a windshield configured as described above will be explained. First, the method for manufacturing the laminated glass 10 will be explained.

[0097] First, the shielding layer 4 described above is laminated onto at least one of the flat outer glass plate 11 and the inner glass plate 12. Next, these glass plates 11 and 12 are shaped to be curved. The shaping method is not particularly limited, and known methods can be used. For example, the flat glass plates can be shaped into a curved form by passing them through a heating furnace and then pressing them with an upper and lower die. Alternatively, the flat outer glass plate and the inner glass plate can be stacked, placed on a frame-shaped mold, and passed through a heating furnace. This softens both glass plates, and they are shaped into a curved form by their own weight.

[0098] Once the outer glass plate 11 and the inner glass plate 12 are formed into a curved shape, the interlayer 13 is then sandwiched between the outer glass plate 11 and the inner glass plate 12, placed in a rubber bag, and pre-bonded at approximately 70-110°C under reduced pressure suction. The interlayer 13 is, for example, a functional layer 133 with through holes 130 sandwiched between adhesive layers 131 and 132. Other pre-bonding methods are also possible. For example, the interlayer 13 is sandwiched between the outer glass plate 11 and the inner glass plate 12 and heated in an oven at 45-65°C. Subsequently, this laminated glass is pressed with a roller at 0.45-0.55 MPa. Next, this laminated glass is heated again in an oven at 80-105°C, and then pressed again with a roller at 0.45-0.55 MPa. Thus, pre-bonding is completed.

[0099] Next, the final bonding is performed. The pre-bonded laminated glass is then bonded in an autoclave, for example, at 8 to 15 atmospheres and 100 to 150 degrees Celsius. Specifically, for example, the final bonding can be performed at 14 atmospheres and 145 degrees Celsius. In this way, the windshield according to this embodiment is manufactured.

[0100] <5. Features> In the windshield configured as described above, the outer glass plate 11 has ultraviolet absorption properties, which can suppress the deterioration of the interlayer film 13 made of resin material.

[0101] <6. Modifications> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. The following modifications can be combined as appropriate.

[0102] <6-1> In the above embodiment, the interlayer 13 is configured such that the functional layer 133 is sandwiched between the first and second adhesive layers 131 and 132. However, the adhesive layer can also be placed on only one side of the functional layer 133. In this case, the functional layer 133 will be bonded to one glass plate, and the adhesive layer will be bonded to the other glass plate.

[0103] <6-2> The shape of the shielding layer 4 is not particularly limited, and various shapes are possible. That is, it is sufficient that at least one opening 43 for photography is formed, and the shape of the opening is not particularly limited. Therefore, two or more openings may be formed.

[0104] <6-3> In the above embodiment, visible light is directed into the camera of the imaging device through the opening. However, devices other than the imaging device may be placed on the windshield of the above embodiment to acquire information from outside the vehicle. For example, devices that acquire various electromagnetic waves other than visible light, such as infrared sensors, infrared cameras, and optical beacons, may be used.

[0105] <6-4> In the above embodiment, an example of applying the automotive window glass according to the present invention to a windshield has been described, but the invention is not limited to this, and as mentioned above, it can also be applied to rear windows, side windows, roof windows, etc. In this case, a shielding layer having an opening as described above is not necessary, and a shielding layer may be provided if necessary.

[0106] The following describes embodiments of the present invention. However, the present invention is not limited to the following embodiments.

[0107] <1. Window Glass According to Examples and Comparative Examples> Below, window glass according to Examples 1 to 11 and window glass according to Comparative Examples 1 and 2 were prepared. Each window glass has an outer glass plate, an inner glass plate, and an interlayer placed between these glass plates. Here, each window glass was constructed using the following seven glass plates. Table 1 shows the composition of each glass plate (unit is mass%). Table 2 shows the physical properties of each glass plate. Each physical property is as described in the above embodiments. All glass plates have a thickness of 2 mm. However, a Low-E film is laminated on the glass surface of glass plate 8. This Low-E film is laminated in the following order from the surface side of the glass plate: a SnO2 layer (first underlayer) with a physical thickness of 25 nm, a SiO2 layer (second underlayer) with a physical thickness of 25 nm, a SnO2 layer with a physical thickness of 340 nm, and an F layer (transparent conductive layer). Laminating the Low-E film slightly increases the YA of the glass plate. Additionally, the thermal transmittance (Ttf) decreases. The units for YA and Tuv are %,

[0108] As an interlayer, a polyvinyl butyral interlayer (without coloring elements) with a thickness of 0.76 mm was prepared. This interlayer was used for all the window panes. Glass plates 1 and 2 correspond to the glass plates in Example 1 described above, glass plates 3 to 6 correspond to the glass plates in Example 2 described above, and glass plate 7 corresponds to the glass plate in Example 3 described above. Glass plate 8 corresponds to clear glass, but has a Low-E film laminated on it. Glass plate 9 corresponds to the glass plate in Example 4.

[0109] <2. Consideration of Each Glass Plate> Glass plates 1 and 2 have low Tuv values, which is thought to be due to their high Fe2O3 content. However, this has resulted in a chromaticity b* of nearly 2, making them closer to yellow than blue. In addition, glass plates 1 and 2 contain TiO2 and CeO2, which are also thought to be factors contributing to the low Tuv values.

[0110] Comparing glass plates 1 and 2, glass plate 2 has a higher Al2O3 content than glass plate 1, which is thought to be the reason for the lower Tuv value. It is also thought to be the reason for the higher chromaticity b* in glass plate 2.

[0111] Glass plates 3-7 have a lower Fe2O3 content compared to glass plates 1 and 2, which is why their Tuv values ​​are considered to be higher. Furthermore, glass plates 3-7 have a higher FeO ratio compared to glass plates 1 and 2, resulting in lower b* values.

[0112] Glass plates 4-6 differ in their Al2O3 content, and the higher the Al2O3 content, the lower the Tuv value. On the other hand, the higher the Al2O3 content, the higher the chromaticity b*.

[0113] Glass plate 7 has a low Fe2O3 content, a low TiO2 content, and no CeO2 content. As a result, its TUV is high. Therefore, its ultraviolet absorption performance is poor. On the other hand, its YA is the highest and its chromaticity b* is the lowest.

[0114] Glass plate 8 is clear glass, but because it has the lowest Fe2O3 content, it has the highest Tuv value. Glass plate 9 has a high total content of Fe2O3 and TiO2, so although it has the lowest YA, it also has the lowest Tuv value.

[0115] <3. Fabrication of Window Glass> Using the glass plates and interlayers described above, window glass according to Examples 1 to 14 and Comparative Examples 1 and 2 was fabricated as follows.

[0116] The glass plates that make up each window pane are shown in Table 3 below (the upper row shows the outer glass plate, and the lower row shows the inner glass plate). The physical properties of each window pane are shown in Table 4. The Fe2O3 difference is the value obtained by subtracting the Fe2O3 content of the inner glass plate from the Fe2O3 content of the outer glass plate. Therefore, if the Fe2O3 difference is positive, it means that the Fe2O3 content of the outer glass plate is higher than that of the inner glass plate, and if the Fe2O3 difference is negative, it means that the Fe2O3 content of the outer glass plate is lower than that of the inner glass plate. The Al2O3 difference is the value obtained by subtracting the Al2O3 content of the inner glass plate from the Al2O3 content of the outer glass plate. The Fe2O3 average is the average of the Fe2O3 content of the outer and inner glass plates. The units for YA and Tuv are %, while the units for t-Fe2O3 difference, Fe2O3 difference, Al2O3 difference, other components, t-Fe2O3 average, and Fe2O3 average are mass%.

[0117] <4. Evaluation> The window glass according to Examples 1 to 14 and Comparative Examples 1 and 2 was evaluated for visible light transmittance, deterioration of the interlayer, and color.

[0118] <4-1. Visible Light Transmittance> Visible light transmittance was evaluated as follows based on the YA of the window glass shown in Table 6: A: YA of 71.5 or higher B: YA of 70.5 or higher and less than 71.5 C: YA of 70.5 or lower

[0119] <4-2. Degradation of the Interlayer> The degradation of the interlayer was evaluated by the following test. Using an ultraviolet irradiation device (HLG-2S manufactured by Suga Test Instruments Co., Ltd.), ultraviolet light (quartz glass mercury lamp (750W)) was irradiated for 500 hours to Examples 1 to 14 and Comparative Examples 1 and 2 in accordance with JIS R3205. The appearance of Examples 1 to 14 and Comparative Examples 1 and 2 was then visually inspected and evaluated as follows (A to C). A: No deterioration of appearance was observed. B: Some yellowing was observed. C: Yellowing was observed throughout.

[0120] <4-3. Color> The window glass was placed in the window frame as a windshield, and the color was checked visually. A: It was a bluish color. B: It was a color between A and B (slightly yellowish). C: It was a yellowish color.

[0121] <4-4. Results> The results are shown in Table 5.

[0122] Comparative Examples 1 and 2 received a rating of C because the yellowing of the interlayer was significant, and the deterioration of the interlayer was easily visible. This is thought to be because glass plate 7 was used as the outer glass plate in Comparative Examples 1 and 2. Since glass plate 7 has a Tuv value exceeding 45%, it is considered to have low ultraviolet absorption performance. Therefore, it is thought that the interlayer deteriorated significantly due to ultraviolet light transmitted through the outer glass plate.

[0123] Examples 3-5, 7-10, and 13 used glass plate 5, glass plate 3, and glass plate 6 as the outer glass plate. Although not as low as glass plate 7, glass plates 5, 3, and 6 had a Tuv of approximately 33-41%, and their ultraviolet absorption performance was not too low, so it is thought that some yellowing was visible. For this reason, the evaluation was B. Examples 1, 2, 6, 11, and 12 all received an A evaluation, which is thought to be because glass plate 1 or glass plate 2 was used as the outer glass plate. Glass plates 1 and 2 both had a low Tuv of approximately 26% and high ultraviolet absorption performance, so it is thought that the deterioration of the interlayer was not visible. Example 14 used glass plate 9 as the outer glass plate, so it had the lowest Tuv and showed high ultraviolet absorption performance.

[0124] Visible light transmittance is primarily determined by the YA (Yield Absorption). As shown in Table 4, the YA of Examples 1 to 13 all exceed 70%, which is required for windshields and side windows. In particular, Examples 4 to 6 and 8 to 13 have a YA exceeding 71.5%, indicating high visible light transmittance. On the other hand, Example 14 uses a glass plate 9, resulting in a low YA, and therefore cannot be used for windshields or side windows, but it can be used, for example, as a roof window.

[0125] In particular, in Examples 5 and 10, where YA is especially high, glass plate 7 is used as the inner glass plate. Since glass plate 7 has the highest YA compared to other glass plates, it is suitable for improving the YA of window glass.

[0126] Regarding color, as mentioned above, a bluish color is often required for automobile windows, so Examples 4, 5, 8-10, and 12-14, which received an evaluation of A, can be suitably used in vehicles. Examples 4, 5, and 8-10 have a chromaticity b* of 2 or less, which is due to the use of glass plates 4-9, which have a chromaticity b* of 1 or less, as the outer and inner glass plates.

[0127] Examples 2, 3, 6, 7, and 11, which received a rating of B, have a chromaticity b* of 2 to 3 and are slightly yellowish, but not as yellowish as those with a rating of A, and can be used in vehicles. Examples 2, 3, 6, 7, and 11 either use glass plates 5 and 7 with a chromaticity b* of 1 or less for either the outer or inner glass plate, or use glass plate 3 with a chromaticity b* of 1.5 or less for both glass plates.

[0128] Example 1, which received a rating of C, has a chromaticity b* of 4 or higher and a yellowish appearance. While this is not ideal, it does not mean that it cannot be used in vehicles. Example 1 uses glass plates 1 with a chromaticity b* of 1.5 or lower for both the outer and inner glass plates, which is likely why the chromaticity b* is high.

[0129] As described above, in order to suppress the deterioration of the interlayer, the outer glass plate must have high ultraviolet absorption performance. On the other hand, for visible light transmission performance, it is required that the Fe2O3 content, which is due to ultraviolet absorption performance, be low. Considering the balance between these factors, it is preferable that the ultraviolet absorption performance of the outer glass plate is higher than that of the inner glass plate. This is because if the ultraviolet absorption performance of the inner glass plate is also high, the visible light transmission performance as window glass will be low. Therefore, from this viewpoint, Examples 6 and 11, in which both visible light transmission and interlayer deterioration are rated A, are preferred. However, considering the ultraviolet absorption performance as window glass, it is better if the average Fe2O3 content in both glass plates is high. In this respect, the average Fe2O3 content in Examples 1 to 11 is all 0.6% by mass or higher, which is preferable.

[0130] 11. Outer glass plate 12. Inner glass plate 13. Interlayer

Claims

1. Automotive window glass comprising: an outer glass plate having ultraviolet light absorption properties; an inner glass plate provided on the interior side of the vehicle from the outer glass plate; and a resin interlayer that bonds the outer glass plate and the inner glass plate and has at least one of ultraviolet light absorption properties, infrared light absorption properties, sound insulation properties, and light-regulating properties with respect to light incident from outside the vehicle.

2. The automotive window glass according to claim 1, wherein the Tuv (ISO 9050-2003) of the outer glass plate is 40.0% or less.

3. The automotive window glass according to claim 1, wherein the Tuv (ISO 9050-2003) of the outer glass plate is 30.0% or less.

4. The automotive window glass according to claim 1, wherein the chromaticity b* according to the CIE standard is 3.0 or less.

5. The automotive window glass according to claim 1, wherein the chromaticity b* according to the CIE standard is 1.5 or less.

6. The automotive window glass according to claim 1, wherein the visible light transmittance YA, measured in accordance with JIS R3106:1998 using a CIE standard A light source, is 70.5% or more and 74.0% or less.

7. The automotive window glass according to claim 1, wherein the visible light transmittance YA, measured in accordance with JIS R3106:1998 using a CIE standard A light source, is 71.5% or more and 74.0% or less.

8. The automobile window glass according to claim 1, wherein the Fe2O3 content in the outer glass plate is higher than the Fe2O3 content in the inner glass plate, and the average of the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.6% by mass or more.

9. The automobile window glass according to claim 8, wherein the difference between the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.15% by mass or more.

10. The automobile window glass according to claim 8, wherein the difference between the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.25% by mass or more.

11. The outer glass plate contains, as a base composition, t-Fe2O3: 0.60% to 0.90% by mass, Fe2O3: 0.50% to 0.60% by mass, Al2O3: 1.2% to 3.0% by mass, CeO2: 0.4% by mass or less, and TiO2: 0.07% by mass or less, with an FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3, converted to Fe2O3, being 26% to 30% or less, the automotive window glass according to claim 1.

12. The outer glass plate contains, as a base composition, t-Fe2O3: 0.60% to 0.90% by mass, Fe2O3: 0.60% to 0.70% by mass, Al2O3: 1.2% to 3.0% by mass, CeO2: 0.8% by mass or less, and TiO2: 0.15% by mass or less, with an FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3, converted to Fe2O3, being 22% to 28% or less, as described in claim 1.

13. The automotive window glass according to claim 1, wherein the Al2O3 content in the outer glass plate is 0.6% by mass or more higher than the Al2O3 content in the inner glass plate.

14. A windshield using the automobile window glass described in claim 1.

15. A side window using the automobile window glass described in claim 1.

16. A roof window using the automobile window glass described in claim 1.

17. The roof window according to claim 16, wherein the difference between the Fe2O3 content in the outer glass plate and the Fe2O3 content in the inner glass plate is 0.60% by mass or more.

18. The roof window according to claim 16, wherein the interlayer comprises a light-adjusting layer capable of switching linear transmittance.

19. The roof window according to claim 18, wherein the light-adjusting layer is a PDLC layer in which liquid crystals are dispersed in a polymer material.

20. The roof window according to claim 18, wherein a LowE film is laminated on the inner glass plate.

Images