Automotive window glass

Abstract

To provide automotive window glass that can improve infrared absorption performance without the need for an interlayer. [Solution] The automotive window glass according to the present invention comprises an outer glass plate, an inner glass plate, and an interlayer that bonded the outer glass plate and the inner glass plate and substantially has no infrared absorption properties, and has a thermal transmittance (Ttf) of 44.0% or less.

Description

Technical Field

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the ultraviolet absorption ability is a function already provided in the interlayer film. When it is provided in both the interlayer film and the inner and outer glass plates, it becomes excessive quality. On the other hand, in order to reduce the heat felt by a person riding in a passenger car, there is an example of adding an infrared absorber to the interlayer film. In this case, there is a problem that the price of the interlayer film increases and the production cost rises.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide automotive window glass capable of improving infrared absorption performance without depending on an interlayer film.

Means for Solving the Problems

[0006] Item 1. An outer glass plate, an inner glass plate, an interlayer film that adheres the outer glass plate and the inner glass plate and substantially has no infrared absorption performance, Equipped with, Automotive window glass with a thermal transmittance (Ttf) of 44.0% or less.

[0007] Item 2. The chromaticity b* of the CIE standard is 2.0 or less. Automotive window glass as described in item 1.

[0008] Item 3. The chromaticity b* of the CIE standard is 1.5 or less. Automotive window glass as described in item 1.

[0009] Item 4. The visible light transmittance YA, measured using a CIE standard A light source in accordance with JIS R3106:1998, is 72.0% or higher. Automotive window glass as described in any of items 1 to 3.

[0010] Item 5. At least one of the outer glass plate and the inner glass plate is The total iron oxide content, calculated as Fe2O3, is 0.60% by mass or more. The total amount of CeO2 and TiO2 is 0.10 mass% or less. It contains, The FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 25% or more. Automotive window glass as described in any of items 1 to 4.

[0011] Item 6. Both the outer glass plate and the inner glass plate are The total iron oxide content, calculated as Fe2O3, is 0.60% by mass or more. The total amount of CeO2 and TiO2 is 0.05% by mass or less. It contains, The FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 25% or more. Automotive window glass as described in any of items 1 to 4.

[0012] Item 7. At least one of the outer glass plate and the inner glass plate is The visible light transmittance YA is 81.5% or more and 83.5% or less, Tuv (ISO9050-2003) with respect to the hot and humid feeling transmittance is 0.5 or more, The automotive window glass according to any one of Items 1 to 6.

[0013] Item 8. Both the outer glass plate and the inner glass plate The visible light transmittance YA is 81.5% or more and 83.5% or less, Tuv (ISO9050-2003) with respect to the hot and humid feeling transmittance is 0.5 or more, The automotive window glass according to any one of Items 1 to 6.

[0014] Item 9. A windshield using the automotive window glass according to any one of Items 1 to 8.

[0015] Item 10. The windshield according to Item 9, extending up to above the driver's seat.

Advantages of the Invention

[0016] According to the present invention, the infrared absorption performance can be improved without depending on the intermediate film.

Brief Description of the Drawings

[0017] [Figure 1] It is a plan view showing an embodiment in which the automotive window glass according to the present invention is applied to a windshield. [Figure 2] It is a cross-sectional view of FIG. 1. [Figure 3] It is a block diagram showing a schematic configuration of an in-vehicle system.

Modes for Carrying Out the Invention

[0018] 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 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 inside 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.

[0019] 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 interior 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 device 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 device 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.

[0020] <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.

[0021] <1-1. Glass plate> First, the outer glass plate 11 and the inner glass plate 12 will be described. 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. Below, the required physical properties of the glass plate will be described first, followed by a description of the composition of the glass plate.

[0022] <1-1-1. Physical properties of glass plates> The physical properties of the glass plate in this embodiment will be described below.

[0023] (1) Heat sensitivity transmittance To describe the relationship between optical properties and the sensation of heat, the heat sensation transmittance was defined as follows.

[0024] (The relationship between increased skin temperature and the feeling of heat) First, the relationship between the increase in skin temperature due to incident sunlight and the perceived level of heat was evaluated. The procedure was as follows: A filter was attached to the light beam emitted from a xenon lamp (Seric XC-500E) to obtain a light source with an energy distribution equivalent to that of sunlight. A panel with a 50 mm diameter hole was placed 416 mm from this light source. The back of the subject's hand was placed on the opposite side of the light source through the hole, and the temperature of the subject's hand was measured every 3 seconds using a thermal viewer. The subject reported their perceived level of heat on a 5-point scale: (1) slightly warm, (2) warm, (3) slightly hot, (4) hot, and (5) very hot. The perceived level of heat was compiled from the results of experiments conducted on 81 subjects. As a result, there was a proportional relationship between the increase in skin temperature and the perceived level of heat, with a 0.5°C increase in skin temperature causing an increase in the perceived level of heat by approximately one step. Furthermore, it was confirmed that when the increase in skin temperature was 3.2°C or less, people did not feel "very hot".

[0025] (skin sensitivity) The degree of skin temperature increase depends on the wavelength of sunlight. This wavelength-dependent increase in skin temperature can be quantified as a coefficient (sensitivity ratio for thermal feeling; hereinafter sometimes referred to as "SRTF") at that wavelength. The SRTFs for the wavelength ranges of 300-840 nm and 840-1350 nm have been reported to be 1.43 and 1, respectively, with the value at 840-1350 nm set to 1. However, the SRTF for the 1350-2500 nm wavelength range, despite its significant impact on the sensation of heat, had not been clarified. Therefore, the SRTF for this wavelength range was determined through experiments using light in the 1350-2500 nm wavelength range, obtained by replacing the filter from the aforementioned light source. This experiment was also conducted by measuring the temperature increase on the back of the subject's hand. The SRTF for the 1350-2500 nm wavelength range was found to be 3.34. The SRTFs for wavelengths below 300 nm and above 2500 nm can be considered practically zero. Table 1 summarizes the skin sensitivity in each wavelength range.

[0026] [Table 1]

[0027] (Thermal sensation transmittance) By weighting the product of the spectral transmittance of the glass plate and the spectrum of sunlight using the skin sensitivity shown in Table 1, the actual sensation of heat felt by a person can be described more accurately using the optical properties of the glass plate. Here, "transmittance for thermal feeling (Ttf)" is defined by the following formula.

[0028]

number

[0029] Here, I sun (λ) is the spectrum of sunlight in Air mass 1.5 as defined in ISO 9845-1, T glass(λ) is the spectral transmittance of the glass plate, and SR(λ) is the skin sensitivity shown in Table 1. air (λ) is the spectral transmittance of the atmosphere, and here it is set to 1 regardless of wavelength.

[0030] The relationship between the increase in skin temperature due to sunlight transmitted through a glass plate and the heat sensation transmittance defined by the above formula was evaluated and confirmed as follows. In the evaluation apparatus described above, a glass plate or laminated glass was placed approximately midway between the light source and the back of the subject's hand, such that the normal to the glass surface and the line connecting the light source and the back of the subject's hand formed a 30-degree angle, and the increase in skin temperature was measured. The increase in skin temperature was calculated by summarizing the results of experiments conducted on 111 subjects. As a result, a good correlation was confirmed between the increase in skin temperature and the heat sensation transmittance.

[0031] Furthermore, the results of the above research showed that in order to prevent people from feeling excessively hot, window glass that causes a rise in skin temperature of 3.5°C or less should be used. In other words, the thermal transmittance (Ttf) of the glass plate or laminated glass used as window glass should be set to approximately 44% or less, preferably 43% or less, more preferably 42% or less, and even more preferably 40% or less.

[0032] A higher FeO content leads to higher infrared absorption performance, which in turn reduces the Ttf (Time to Fuel). From this perspective, the FeO content is preferably, for example, 0.2% by mass or higher. Additionally, a higher Fe2O3 content, though not as high as FeO, can also reduce the Ttf. For example, if the total iron oxide content converted to Fe2O3 is denoted as t-Fe2O3, the FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3, is preferably 25% to 30%, and more preferably 28% to 30%. This increases infrared absorption performance and lowers the Ttf.

[0033] (2) Ultraviolet transmittance 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 (ISO9050-2003) of the outer glass plate 11 is preferably 40.0% or less, and more preferably 30.0% or less.

[0034] To reduce Tuv, a higher Fe2O3 content in the outer glass plate 11 is preferable. The Fe2O3 content is preferably 0.5% by mass or more, and more preferably 0.6% by mass or more. However, since a high Fe2O3 content results in low visible light transmittance, 0.7% by mass or less is preferable.

[0035] Furthermore, the glass plates 11 and 12 may contain TiO2 and CeO2, and a higher content of these can reduce Tuv. The total content of TiO2 and CeO2 is preferably, for example, 0.05% by mass or more, more preferably 0.10% by mass or more, and particularly preferably 0.20% by mass or more.

[0036] (3) CIE standard chromaticity b* Furthermore, a higher Fe2O3 content 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 desirable from this perspective, and therefore, a lower Fe2O3 content is preferable. Such color adjustments can also be achieved by adjusting the TiO2 and CeO2 content. For example, a lower TiO2 and CeO2 content can lower the chromaticity b*.

[0037] Furthermore, if the FeO content in the glass plates 11 and 12 is high, the infrared absorption performance will increase, and the chromaticity b* will decrease. 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 25% or more and 30%, and more preferably 28% or more and 30%.

[0038] (4)Visible light transmittance YA For visible light transmittance YA measured according to JIS R3106:1998 using a CIE standard A light source, a value of 81.5% or more and 83.5% or less is preferred.

[0039] If the visible light transmittance YA is less than 81.5%, the Fe2O3 content may be too high. In this case, when laminated glass is formed using two glass plates with a visible light transmittance of less than 81.5%, the visible light transmittance YA may fall below 70%, making it unsuitable for use as a windshield. However, because the Fe2O3 content is high, the overall t-Fe2O3 will be high, resulting in a lower Ttf. In this case, it becomes difficult to reduce the Ttf while maintaining a visible light transmittance YA sufficient for use as a windshield, but it can be used as window glass where a low YA is not a problem, such as for roof windows.

[0040] In addition, other coloring components such as CoO and NiO can be included in high concentrations. However, while these can lower the visible light transmittance YA, they have little effect on lowering Ttf.

[0041] If the visible light transmittance (YA) is higher than 83.5%, the Fe2O3 content may be too low. Therefore, it may not contain enough t-Fe2O3 to reduce the Ttf (Total Tf).

[0042] (5) Tuv / Ttf As mentioned above, the preferred range for visible light transmittance YA is not wide. In other words, the preferred range for t-Fe2O3 content is also not wide. Therefore, we consider Tuv / Ttf. Tuv / Ttf is the ratio of "ease of transmission of ultraviolet light" to "ease of transmission of infrared light". In other words, it is the ratio of "infrared absorption capacity" to "ultraviolet absorption performance". Therefore, the higher this value, the more FeO can be obtained within the limited t-Fe2O3, and thus Ttf can be reduced.

[0043] For example, if the visible light transmittance YA is between 81.5% and 83.5%, and the Tuv / Ttf ratio is 0.5 or higher, the Ttf will be low, making it suitable for use as a windshield.

[0044] Furthermore, TiO2, a coloring component that absorbs ultraviolet light, significantly reduces Tuv, but at the same time reduces Ya (for example, the glass plate in Example 2 below, and glass plate 2 in the Examples). On the other hand, TiO2 has little effect on lowering Ttf, so when TiO2 is added (however, it may be unintentionally included as a trace component of the raw material), the Tuv / Ttf ratio becomes higher. In this case, it becomes difficult to reduce Ttf while having a visible light transmittance YA sufficient for use in a windshield. Therefore, the upper limit of Tuv / Ttf is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 0.9 or less.

[0045] When forming laminated glass, it is preferable to use one or more, preferably two, glass plates with a Tuv / Ttf of 0.5 or higher as described above.

[0046] Each glass plate 11, 12 can have, for example, the following composition.

[0047] (Example 1) • Fe2O3: 0.45% by mass or more and 0.60% by mass or less (preferably 0.50% by mass or more and 0.55% by mass or less) • FeO: 0.15% by mass or more and 0.30% by mass or less (preferably 0.20% by mass or more and 0.30% by mass or less) • CeO2: 0.05% 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), It contains as its base composition, The FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 20% or more and 30% or less (preferably 26% or more and 30% or less). • The total content of CeO2 and TiO2 is 0.1% by mass or less (preferably 0.05% by mass or less).

[0048] Example 1 has a high infrared absorption performance due to its high FeO content. However, its ultraviolet absorption performance is not as high as Example 2 because of its low combined CeO2 and TiO2 content. Consequently, its chromaticity b* is low.

[0049] (Example 2) • Fe2O3: 0.45% by mass or more and 0.60% by mass or less (preferably 0.55% by mass or more and 0.60% by mass or less) • FeO: 0.15% by mass or more and 0.30% by mass or less (preferably 0.2% by mass or more and 0.3% by mass or less) CeO2: 0.05% by mass or more and 0.20% by mass or less (preferably 0.07% by mass or more), • TiO2: 0.05% by mass or more and 1.0% by mass or less (preferably 0.10% by mass or 0.80% by mass or less) It contains as its base composition, The FeO ratio, expressed as the mass ratio of FeO to t-Fe2O3 converted to Fe2O3, is 20% or more and 30% or less (preferably 23% or more and 26% or less). • The total content of CeO2 and TiO2 is 0.1% by mass or more and 1.0% by mass or less (preferably 0.15% by mass or more, more preferably 0.20% by mass or more).

[0050] Example 2 exhibits high infrared absorption performance due to its high FeO content. Furthermore, its high combined CeO2 and TiO2 content results in higher ultraviolet absorption performance compared to Example 1. However, this also results in a slightly higher chromaticity b*.

[0051] For example, by combining glass plates like those in Example 1 and Example 2 described above, laminated glass with various properties can be formed. For instance, if laminated glass is constructed using at least one of Example 1 and Example 2, the infrared absorption performance is improved.

[0052] The thickness of the laminated glass 10 according to this embodiment is not particularly limited, but the sum of the thicknesses 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 sum of the thicknesses of the outer glass plate 11 and the inner glass plate 12 be 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 weight, it is necessary to reduce the sum of the thicknesses of the outer glass plate 11 and the inner glass plate 12, so the thickness of each glass plate is not particularly limited, but for example, the thicknesses of the outer glass plate 11 and the inner glass plate 12 can be determined as follows.

[0053] The outer glass plate 11 primarily needs to be durable and impact-resistant against external damage, and as a car windshield, it needs to be impact-resistant against flying objects such as pebbles. On the other hand, a greater thickness increases weight, which is undesirable. 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. The choice of thickness can be determined according to the application of the glass.

[0054] The thickness of the inner glass plate 12 can be the same as that of the outer glass plate 11, but for example, to reduce the weight of the laminated glass 10, its thickness can be made smaller than that of the outer glass plate 11. Specifically, considering the strength of the glass, a thickness of 0.6 to 2.0 mm is preferable, 0.8 to 1.6 mm is preferable, and 1.0 to 1.4 mm is particularly preferable. Furthermore, 0.8 to 1.3 mm is preferable. The thickness of the inner glass plate 12 can also be determined according to the application of the glass.

[0055] 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 horizontal 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.

[0056] <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 positioned between these two adhesive layers 131 and 132.

[0057] 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.

[0058] As described above, infrared absorption performance (infrared cutting performance) is provided by the glass plates 11 and 12, so the interlayer 13 of this embodiment does not substantially possess infrared absorption performance. For example, if oxide fine particles (infrared absorbers) are included in the adhesive layers 131, 132 or the functional layer 133, infrared absorption performance will be actively exhibited. Examples of oxide fine particles include tin-doped indium oxide (ITO), antimond-doped tin oxide (ATO), and aluminum-doped zinc oxide (AZO). However, even without using such oxide fine particles, the interlayer 13 may absorb a small amount of infrared radiation to an extent that is not practical. Therefore, saying that the interlayer 13 does not substantially possess infrared absorption performance means that the inclusion of oxide fine particles or other functions to exhibit practical infrared absorption performance is excluded, while allowing for cases where a small amount of infrared radiation is absorbed to an extent that is not practical.

[0059] The adhesive layers 131 and 132 of this embodiment can have ultraviolet absorption properties instead of infrared absorption properties. For example, at least one of the adhesive layers 131 and 132 can 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 an ultraviolet absorber be contained in the first adhesive layer 131. Furthermore, since such ultraviolet absorbers are prone to degradation by ultraviolet rays, it is preferable that the outer glass plate 11 has high ultraviolet absorption properties when using them.

[0060] 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.

[0061] Specific examples of UV absorbers used in interlayers include the following: Benzotriazole type (1): Tinuvin 326, represented by the following formula (1), where X is a chlorine atom, R 21 is a methyl group, R 22 Y is a tert-butyl group. 1 is a hydrogen atom, Y 2 A compound represented by a hydroxyl group. Trade name "Tinuvin 326", manufactured by Ciba Specialty Chemicals. Benzotriazole derivatives (2): 2-(2,4-dihydroxyphenyl)-2H-benzotriazole [ka]

[0062] The first adhesive layer 131 and the second adhesive layer 132, before being bonded to each glass plate 11 and 12, 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 and 12.

[0063] 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.

[0064] 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 characteristics specified in JIS R3211 and R3212 for the windshield.

[0065] Depending on the application, various functional films can be used for the functional layer 133. For example, known heat-shielding films, heat-generating films, projection films, light-emitting films, antenna films, and dimming films can be used.

[0066] 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.

[0067] 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-polarized 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 an enhanced reflective 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.

[0068] 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.

[0069] The light-emitting film has built-in LEDs or similar devices that emit light to display predetermined characters, shapes, or other designs.

[0070] Antenna films, like heating films, are films on which antennas for FM, AM, DTV, DAB, etc., are arranged on the aforementioned base film.

[0071] A dimmable film (dimmable layer) is a film that can change the visibility from outside a 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 example, on roof windows.

[0072] The above is an example of functional layer 133, and is not limited to these examples.

[0073] 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.

[0074] Furthermore, the functional layer 133 has a rectangular through-hole (transmissive region) 130, 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.

[0075] 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). Then, the thickness of each adhesive layer 131, 132 and functional layer 133 is identified visually and measured. In this case, 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.

[0076] 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.

[0077] 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.

[0078] <1-3. Physical Properties of Laminated Glass> Next, we will describe the desirable physical properties of laminated glass. (1)Visible light transmittance YA For laminated glass to be used as a windshield or side window, the YA (Gas Yield) must be 70.0% or higher (Article 39, Paragraph 3, Item 7 of the Notification Specifying the Details of Safety Standards for Road Vehicles), preferably 70.5% or higher, and more preferably 72.0% or higher. However, if the YA is too high, the solar radiation transmittance (Ttf) may decrease, so it is preferable that it be 75.0% or lower, and more preferably 73.0% or lower. To achieve a YA of 70% or higher, either of the glass plates described in Example 1 and Example 2 above can be used.

[0079] (2) CIE standard chromaticity b* As described above, since a bluish tint is preferred for automotive window glass, the chromaticity b* is preferably 2.0 or less, and more preferably 1.5 or less. To achieve this, for example, a glass plate like at least one of Example 1 or Example 3 described above can be used as either the outer glass plate 11 or the inner glass plate 12.

[0080] (3) Thermal sensation transmittance (Ttf) As described above, the thermal transmittance is calculated, but the thermal transmittance (Ttf) of the laminated glass should be set to approximately 44% or less, preferably 42% or less, and more preferably 40% or less. This makes it possible to prevent people from feeling excessively hot, as described above. To achieve this, for example, glass plates such as at least one of Example 1 or Example 2 described above can be used for the outer glass plate 11 and the inner glass plate 12.

[0081] <1-4. Others> Various functional films can be laminated onto the interior surface of the inner glass panel 12, for example, a Low-E film can be laminated. Furthermore, if UV absorption performance is to be enhanced, a UV-absorbing film can be laminated onto the exterior surface of the outer glass panel 11.

[0082] <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 this 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 imaging 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.

[0083] 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 imaging 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 imaging device 2 is not visible from inside the vehicle.

[0084] 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.

[0085] 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 and 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.

[0086] [Table 2] *1, Main components: copper oxide, chromium oxide, iron oxide, and manganese oxide *2, Main components: Bismuth borosilicate, zinc borosilicate

[0087] 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.

[0088] <3. In-vehicle systems> Next, an in-vehicle system comprising a camera 2 and an image processing device 3 will be described using Figures 2 and 4. Figure 4 illustrates the configuration of the in-vehicle system. As illustrated in Figure 4, the in-vehicle system according to this embodiment comprises the camera 2 and an image processing device 3 connected to the camera 2.

[0089] 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 modified as appropriate, with additions, omissions, and modifications depending on the embodiment.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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. Also, 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.

[0094] 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.

[0095] 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.

[0096] 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 in a predetermined position inside the vehicle.

[0097] <4. Method for manufacturing a windshield> Next, we will describe an example of a method for manufacturing a windshield configured as described above. First, we will describe the method for manufacturing laminated glass 10.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] <5. Features> In the windshield configured as described above, at least one of the outer glass plate 11 and the inner glass plate has infrared absorption properties, thus suppressing the feeling of temperature differences experienced by the occupants. Furthermore, since one of the glass plates 11 or 12 has infrared absorption properties, it is not necessary for the interlayer 13 to have that function. Therefore, other functions can be added to the interlayer 13.

[0102] <6. Variation> 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. Furthermore, each of the following modifications can be combined with the above embodiment as appropriate.

[0103] <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 adhere to one glass plate, and the adhesive layer will adhere to the other glass plate.

[0104] <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 or more openings 43 for imaging are formed, and the shape of the openings is not particularly limited. Therefore, two or more openings may be formed.

[0105] <6-3> In the above embodiment, visible light is allowed to enter 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.

[0106] <6-4> In the above embodiment, an example of applying the automotive window glass according to the present invention to a windshield was 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 the opening described above is not necessary, and a shielding layer may be provided if necessary. When using the window glass of the present invention as a windshield, for example, the window glass can be formed to extend above the driver's head. That is, it can be a window glass that combines a windshield and a roof window. [Examples]

[0107] The following describes embodiments of the present invention. However, the present invention is not limited to the following embodiments.

[0108] <1. Window glass relating to examples and comparative examples> In the following, window panes according to Examples 1 to 3 and window panes according to the comparative example were prepared. Each window pane has an outer glass plate, an inner glass plate, and an interlayer placed between these glass plates. Here, each window pane was constructed using the following three glass plates. Table 3 shows the composition of each glass plate (unit is mass%). Table 4 shows the physical properties of each glass plate. Each physical property is the same as that described in the above embodiments. [Table 3] [Table 4] However, Tuv refers to Tuv ISO9050-2003.

[0109] A 0.76 mm thick polyvinyl butyral interlayer (without coloring elements) was prepared as an interlayer. This interlayer was used for all the window panes. Glass plates 1 and 2 correspond to the glass plates in Examples 1 and 2 described above, respectively.

[0110] <2. Consideration of each glass plate> Comparing glass plates 1 and 2, glass plate 2 has a slightly higher FeO and Fe2O3 content than glass plate 1. As a result, the Ttf of glass plate 2 is slightly lower than that of glass plate 1, and the YA of glass plate 2 is also slightly lower than that of glass plate 1. On the other hand, the total TiO2 and CeO2 content of glass plate 2 is higher than that of glass plate 1. As a result, the Tuv of glass plate 2 is lower than that of glass plate 1, but the chromaticity b* of glass plate 2 is higher than that of glass plate 1.

[0111] Glass plate 3 has a lower Fe2O3 content than glass plates 1 and 2. As a result, the Ttf and Tuv of glass plate 3 are higher than those of glass plates 1 and 2, but the chromaticity b* is lower. This is also due to the lower total TiO2 and CeO2 content of glass plate 3. Furthermore, due to this composition, glass plate 3 has the highest YA.

[0112] Furthermore, glass plate 1 has a Tuv / Ttf ratio of 0.5 or higher, resulting in a high YA and low Ttf. On the other hand, glass plate 2 has a Tuv / Ttf ratio of less than 0.5, resulting in a low Ttf but a slightly lower YA. However, because of its low Tuv, it has high UV absorption performance.

[0113] <3. Window glass fabrication> Using the glass plates and interlayers described above, window glass according to Examples 1 to 3 and the Comparative Example was fabricated as follows.

[0114] The glass plates constituting each window pane are shown in Table 5 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. Table 6 shows the physical properties of Examples 1 to 3 and the comparative example. [Table 5] [Table 6]

[0115] <4. Evaluation> The window glass according to Examples 1-3 and the Comparative Example described above was evaluated for visible light transmittance, deterioration of the interlayer, and color.

[0116] <4-1. Visible light transparency> Visible light transmittance was evaluated as follows, based on the YA of the window glass shown in Table 6. A: YA is 72.0 or higher B:YA is less than 72.0

[0117] <4-2. Infrared (IR) Cut Performance> The following evaluation was performed using Ttf. A: 44% or less B: Higher than 44%

[0118] <4-3. Color> The evaluation was based on chromaticity b*. A: It was a bluish color (chromaticity b* was less than 1.5). B: The color was between A and B (slightly yellowish) (chromaticity b* was between 1.5 and less than 3.0). C: The color was yellowish (chromaticity b* was 3.0 or higher).

[0119] <4-4.Results> The results are shown in Table 7. [Table 7]

[0120] <4-4-1. Regarding infrared absorption performance (IR cut performance)> The comparative example has a Ttf of over 50%, indicating low IR cut performance. On the other hand, Examples 1-3 have a Ttf of 44% or less, indicating high IR cut performance.

[0121] Examples 1-3 obtained the above A rating because they used either glass plate 1 or 2 with a low Ttf.

[0122] <4-4-2. About Visible Light Transmittance> Visible light transmittance is primarily determined by the YA (Yield Absorption). As shown in Table 6, the YA of Example 1 is 72.0% or higher, making it suitable for use in windshields and side windows. However, the YA of Examples 2 and 3 both exceed the 70% required for windshields and side windows. Therefore, Examples 1 to 3 can be used as windshields and side windows.

[0123] <4-4-3. About Color> As mentioned above, since a bluish tint is often required for automobile windows, Example 1, which has an evaluation of A, can be suitably used in vehicles. In Example 1, the chromaticity b* is 2 or less, which is because glass plates 1 with a chromaticity b* of 1 or less are used as the outer and inner glass plates.

[0124] Example 3, which received a rating of B, has a chromaticity b* of 2-3 and is slightly yellowish, but not as yellowish as a rating of A, and can be used in vehicles. In Example 3, either the outer glass plate or the inner glass plate is made of glass plate 1 with a chromaticity b* of 1 or less.

[0125] Example 2, which received a rating of C, has a chromaticity b* of 3 or higher and a yellowish appearance. While this is not ideal, it does not mean that it cannot be used in vehicles. Example 2 uses glass plates 2 in which both the outer and inner glass plates have a chromaticity b* of 1.5 or higher, which is likely why the chromaticity b* is high. [Explanation of Symbols]

[0126] 11. Outer glass panel 12 Inner glass plate 13 Interlayer

Claims

1. Outer glass panel and The inner glass plate, The outer glass plate and the inner glass plate are bonded together, and an interlayer which substantially has no infrared absorption properties is bonded to them, Equipped with, Automotive window glass with a thermal transmittance (Ttf) of 44.0% or less.

2. The CIE standard chromaticity b* is 2.0 or less. Automobile window glass according to claim 1.

3. The CIE standard chromaticity b* is 1.5 or less. Automobile window glass according to claim 1.

4. The visible light transmittance YA, measured according to JIS R3106:1998 using a CIE standard A light source, is 72.0% or higher. Automobile window glass according to claim 1.

5. At least one of the outer glass plate and the inner glass plate is Fe 2 O 3 The total iron oxide content converted to t-Fe 2 O 3 0.60% by mass or more, CEO 2 and TiO 2 The total is 0.10% by mass or less. It contains, Fe 2 O 3 The t-Fe of FeO converted to 2 O 3 The FeO ratio, represented by the mass ratio to, is 25% or more. Automobile window glass according to claim 1.

6. Both the outer glass plate and the inner glass plate are Fe 2 O 3 The total iron oxide content converted to t-Fe 2 O 3 0.60% by mass or more, CEO 2 and TiO 2 The total is 0.05% by mass or less. It contains, Fe 2 O 3 The t-Fe of FeO converted to 2 O 3 The FeO ratio, expressed as a mass ratio to the total, is 25% or more. Automobile window glass according to claim 1.

7. At least one of the outer glass plate and the inner glass plate is The aforementioned visible light transmittance YA is 81.5% or more and 83.5% or less. The Tuv (ISO 9050-2003) relative to the aforementioned heat sensation transmittance is 0.5 or higher. Automobile window glass according to claim 1.

8. Both the outer glass plate and the inner glass plate are The aforementioned visible light transmittance YA is 81.5% or more and 83.5% or less. The Tuv (ISO 9050-2003) relative to the aforementioned heat sensation transmittance is 0.5 or higher. Automobile window glass according to claim 1.

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

10. The windshield according to claim 9, which extends above the driver's seat.

Images