Glass laminate for vehicle roof

Abstract

To provide a glass laminate for a vehicle roof, allowing a color tone of a colored intermediate layer to be appropriately visible from a vehicle interior.SOLUTION: A glass laminate 10 for a vehicle roof is used for at least part of a vehicle roof 2. The glass laminate 10 includes: a vehicle-exterior glass sheet 12 and a vehicle-interior glass sheet 11 as a pair of glass sheets 11 and 12; and an intermediate layer 13 disposed between the pair of glass sheets 11 and 12. The intermediate layer 13 can contain a hue conversion substance. At least the vehicle-interior glass sheet 11 of the pair of glass sheets 11 and 12 maintains a hue of the intermediate layer 13 which is visible from a vehicle interior.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a laminated glass for a vehicle roof. [Background technology]

[0002] Light-adjustable laminated glass, in which a light-adjusting section whose transmittance can be changed electrically is enclosed in an interlayer, is known for use in automobile and train windowpanes. The light-adjusting section is composed of a light-adjusting layer and a pair of conductive layers sandwiching the light-adjusting layer. To improve the privacy of passengers, such light-adjustable laminated glass, for example, scatters light and becomes like frosted glass when the light-adjusting layer is in the off state, and becomes transparent when the light-adjusting section is in the on state. For example, a liquid crystal element is used as the light-adjusting layer (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 153998 Summary of the Invention [Problem to be solved by the invention]

[0004] The light control laminated glass may be used, for example, in the roof of a vehicle. The light control laminated glass can be colored by adjusting the color tone of the light control part. The light control laminated glass has a light control part, an interior glass plate, and an exterior glass plate, and further has a support member for the light control part, an adhesive layer, etc. between the light control part and the interior glass plate, and between the light control part and the exterior glass plate as intermediate layers. Therefore, the light control laminated glass can also color these support members, adhesive layers, etc. In this way, even in the light control laminated glass colored in the intermediate layer including the light control part, when the interior glass plate is colored, the coloring of the intermediate layer may be canceled out by the coloring of the interior glass plate. Therefore, there is room for improvement in the laminated glass for vehicle roofs having a colorable intermediate layer.

[0005] Therefore, there is a demand for a laminated glass for a vehicle roof, in which the color tone of the colored intermediate layer can be properly viewed from inside the vehicle. [Means for solving the problem]

[0006] A characteristic configuration of the laminated glass for a vehicle roof according to the present invention is that it is a laminated glass for a vehicle roof used for at least a part of the roof of a vehicle, comprising a pair of glass plates, i.e., an exterior glass plate and an interior glass plate, and an intermediate layer disposed between the pair of glass plates, the intermediate layer being configured to be capable of containing a hue conversion substance, and at least the interior glass plate of the pair of glass plates maintains the hue of the intermediate layer that is visible from inside the vehicle.

[0007] According to this configuration, in the laminated glass for vehicles, at least the interior glass sheet of the pair of glass sheets maintains a hue of the intermediate layer that is visible from inside the vehicle, so that the hue of the intermediate layer is not obstructed by the interior glass sheet of the vehicle, and the laminated glass for vehicles can be used while appropriately enjoying the hue of the intermediate layer in the vehicle interior space.

[0008] Another characteristic feature is that the intermediate layer includes a dimming layer whose light transmittance can be adjusted by application of a voltage, a pair of conductive layers sandwiching the dimming layer, and a pair of supporting substrates sandwiching the pair of conductive layers.

[0009] As in the present configuration, by including a light control part in the intermediate layer, the glass plate for a vehicle roof can be colored by using one or both of the coloring by the light control layer and the coloring by the intermediate layer other than the light control part. This allows the laminated glass for a vehicle to use various coloring forms, and increases the degree of freedom in changing the color of the vehicle interior space.

[0010] Another characteristic feature is that the optical element further includes a light-shielding layer that absorbs or reflects light of wavelengths other than visible light.

[0011] If the laminated glass for vehicle roofs further comprises a light-shielding layer that absorbs or reflects light of wavelengths other than visible light as in the present configuration, the laminated glass for vehicle roofs can be provided with a heat insulating effect or a heat shielding effect. In addition, the light-shielding layer transmits visible light, so that the hue of the intermediate layer can be appropriately enjoyed and utilized in the vehicle interior space. This improves the functionality of the laminated glass for vehicle roofs.

[0012] Another characteristic feature is that the light shielding layer includes a Low-E film.

[0013] If the light-shielding layer contains a Low-E film as in the present configuration, the laminated glass for vehicle roofs can adequately exhibit the heat insulating effect or heat shielding effect due to the light-shielding layer.

[0014] Another characteristic feature is that the Low-E film included in the light-shielding layer is provided on the interior surface of the interior-facing glass sheet.

[0015] As in the present configuration, if the Low-E film contained in the light-shielding layer is provided on the interior surface of the vehicle-interior glass sheet, the Low-E film can enhance the heat insulating effect of the laminated glass for vehicle roof.

[0016] Another characteristic feature of the interior glass sheet is that, in chromaticity represented on the CIE L*a*b* chromaticity coordinate diagram, a* is -6.0 or more and 6.0 or less, and b* is -5.0 or more and 5.0 or less.

[0017] With the chromaticity of this configuration, the laminated glass for a vehicle roof can properly maintain the hue of the intermediate layer that is visible from inside the vehicle through the vehicle-interior glass plate.

[0018] Another characteristic feature is that when the photochromic layer is in a transmissive state in which it transmits visible light, the chromaticity represented on the CIE L*a*b* chromaticity coordinate diagram is such that a* is greater than or equal to -10.0 and less than or equal to 6.5, and b* is greater than or equal to -3.5 and less than or equal to 6.5.

[0019] With the chromaticity of this configuration, the laminated glass for a vehicle roof can appropriately maintain the hue of the intermediate layer that is visible from inside the vehicle by means of the pair of glass plates.

[0020] Another characteristic feature is that the glass sheet facing the vehicle interior is made of soda-lime glass containing 1.2 wt % or less of Fe2O3 in total and 0.5 wt % or less of TiO2.

[0021] When the glass sheet on the vehicle interior side is made of soda lime glass and contains a large amount of Fe2O3 or TiO2, the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram shows that a* is negative and greenish, and b* is positive and yellowish. On the other hand, if the glass sheet on the vehicle interior side is made of soda lime glass with a total amount of Fe2O3 of 1.2 wt% or less and TiO2 of 0.5 wt% or less, as in the present configuration, a* and b* are small and the color tone is suppressed. This allows the laminated glass for vehicle roof to properly maintain the hue of the intermediate layer visible from inside the vehicle. The total amount of Fe2O3 is the total amount of iron oxide when it is assumed that FeO and Fe2O3 are all present as Fe2O3, taking into account that both FeO and Fe2O3 exist as iron oxide in soda lime glass.

[0022] Another characteristic feature is that the glass sheet facing the vehicle interior is made of soda-lime glass containing 100 ppm or less of Co3O4 and 5 ppm or less of Se.

[0023] When the vehicle interior glass sheet is made of soda glass and contains a large amount of Co3O4, the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram is such that b* is more negative and greenish. When the vehicle interior glass sheet is made of soda glass and contains a large amount of Se, the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram is such that a* is more positive and reddish, and b* is more positive and yellowish. On the other hand, when the vehicle interior glass sheet has Co3O4 of 100 ppm or less and Se of 5 ppm or less, as in the present configuration, the color tone change due to a* and b* is suppressed. This allows the vehicle laminated glass to properly maintain the hue of the intermediate layer visible from inside the vehicle.

[0024] Another characteristic feature is that the pair of glass plates are made of soda-lime glass having the same composition.

[0025] When the pair of glass plates are made of soda-lime glass of the same composition as in the present configuration, a common glass plate can be used as the pair of glass plates, making it possible to easily configure a laminated glass for a vehicle roof.

[0026] Another characteristic configuration is that the interior glass plate is A color component function Fa correlated with a* and a color component function Fb correlated with b* of chromaticity represented in the CIE L*a*b* chromaticity coordinate diagram are calculated based on the total amount of Fe2O3, TiO2, Co3O4, and Se contained in the interior glass sheet. Fa = -3.5 x [total amount of Fe2O3 (wt%)] -1.5 x [TiO2 (wt%)] + 0.20 x [Se (ppm)], and Fb = [Total amount of Fe2O3 (wt%)] + 4 × [TiO2 (wt%)] - 43 × 10 -4 ×〔Co3O4(ppm)〕+0.4×10 -4 ×〔Se(ppm)〕 When we define The feature is that it is made of soda lime glass that satisfies −9≦Fa≦1 and −5≦Fb≦10.

[0027] In the chromaticity shown on the CIE L*a*b* chromaticity coordinate diagram, a* indicates a chromaticity that is reddish when it is positive and greenish when it is negative. Also, b* indicates a chromaticity that is yellowish when it is positive and blueish when it is negative. When the glass sheet on the inside of the car is made of soda glass and contains a lot of Fe2O3 or TiO2, a* increases on the negative side and becomes greenish, and b* increases on the positive side and becomes yellowish. Therefore, among the chromaticities shown on the CIE L*a*b* chromaticity coordinate diagram, the color component function Fa, which is correlated with a*, and the color component function Fb, which is correlated with b*, are proportional to a* and b*, respectively, by defining the coefficients of each component as above. Therefore, as in the present configuration, if the interior glass sheet is made of soda glass and Fa and Fb satisfy the above ranges, the interior glass sheet can have a* and b* within a predetermined range in chromaticity represented on the CIE L*a*b* chromaticity coordinate diagram, thereby allowing the vehicle laminated glass to properly maintain the hue of the intermediate layer visible from inside the vehicle. [Brief description of the drawings]

[0028] [Figure 1] FIG. 2 is a diagram showing a laminated glass for a vehicle roof arranged on the roof of a vehicle. [Diagram 2] FIG. 2 is a partial cross-sectional view of a laminated glass for a vehicle roof. [Diagram 3] FIG. 5 is a partial cross-sectional view of a laminated glass for a vehicle roof according to a second embodiment. [Figure 4] FIG. 11 is a partial cross-sectional view of a laminated glass for a vehicle roof according to a third embodiment. [Diagram 5] FIG. 11 is a partial cross-sectional view of a laminated glass for a vehicle roof according to a fourth embodiment. [Figure 6] FIG. 11 is a partial cross-sectional view of a laminated glass for a vehicle roof according to a fifth embodiment. [Figure 7] FIG. 13 is a partial cross-sectional view of a laminated glass for a vehicle roof according to a sixth embodiment. [Figure 8] FIG. 2 is a diagram showing the chromaticity of the single plate glass of the example, expressed on the CIE L*a*b* chromaticity coordinate diagram. [Figure 9] FIG. 2 is a diagram showing the chromaticity of the laminated glass of the examples on the CIE L*a*b* chromaticity coordinate diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of the laminated glass for a vehicle roof according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications are possible without departing from the scope of the present invention.

[0030] As shown in FIG. 1, a laminated glass 10 for a vehicle roof (hereinafter referred to as “laminated glass 10 ”) is disposed in a part of a roof 2 of a vehicle 1 .

[0031] [First embodiment] As shown in FIG. 2, the laminated glass 10 includes a pair of glass plates 11, 12, an intermediate layer 13, a light-adjusting layer 14, and a pair of conductive layers 15, 15. The intermediate layer 13 includes, for example, a first intermediate layer 31 (an example of an adhesive layer) that is bonded to the pair of glass plates 11, 12, a second intermediate layer 32 (an example of a support substrate) that is disposed between the first intermediate layer 31 and the light-adjusting layer 14, and the light-adjusting layer 14 and a pair of conductive layers 15, 15. The light-adjusting section 20 includes the light-adjusting layer 14, the pair of conductive layers 15, 15, and the second intermediate layer 32. The light-adjusting section 20 includes an element that can switch the light transmittance of the laminated glass 10. In addition, the intermediate layer 13 including the light-adjusting layer 14 is configured to be able to contain a color-changing substance.

[0032] The light control unit 20 is switchable between, for example, a low transmittance state and a high transmittance state. The transmittance may be switchable in multiple steps, or may be switchable steplessly (continuously). The light control unit 20 may be disposed over substantially the entire laminated glass 10, or may be disposed over only a portion of the laminated glass 10, as necessary. The planar shape of the light control unit 20 is, for example, a rectangle smaller than the planar shape of the laminated glass 10.

[0033] The dimming section 20 is covered with a first intermediate layer 31. In the dimming section 20, the second intermediate layer 32 supports the pair of conductive layers 15, 15. The first intermediate layer 31 is a buffer film having a smaller Young's modulus than the second intermediate layer 32. The first intermediate layer 31 and the second intermediate layer 32 are both formed of resin, and the pair of glass plates 11, 12 are bonded to the dimming section 20 via the first intermediate layer 31. The intermediate layer 13 including the dimming layer 14, the first intermediate layer 31, and the second intermediate layer 32 is configured to contain a hue conversion material capable of changing the hue of each.

[0034] For example, the light-adjusting layer 14 has a parallel light transmittance of less than 30% when no voltage is applied, and a parallel light transmittance of 30% or more when a voltage is applied. It is more preferable that the light-adjusting layer 14 has a parallel light transmittance of 20% or less when no voltage is applied, and a parallel light transmittance of 40% or more when a voltage is applied.

[0035] The switchable layer 14 may have a haze of 10% or more when no voltage is applied and less than 10% when a voltage is applied. More preferably, the switchable layer 14 has a haze of 20% or more when no voltage is applied and less than 8% when a voltage is applied. The switchable layer 14 may be formed to have a smaller surface area than the first intermediate layer 31 and the second intermediate layer 32, which are the intermediate layer 13.

[0036] For example, the light-controlling layer 14 formed of liquid crystal or the like is configured as a light-controlling film including a pair of conductive layers 15, 15 arranged on both sides of the light-controlling layer 14. The light-controlling layer 14 controls the haze ratio of the film by, for example, the presence or absence of electrical current, to create a transparent state and an opaque state. That is, the light-controlling layer 14 can adjust the light transmittance by applying a voltage. As the light-controlling layer 14, for example, a known type such as a PDLC (Polymer Dispersed Liquid Crystal) type or an SPD (Suspended Particle Device) type using liquid crystal, an electrochromic type, or a thermochromic type can be used.

[0037] The pair of conductive layers 15, 15 are disposed to sandwich the switchable layer 14, and when power is supplied, a voltage is applied to the switchable layer 14. The first intermediate layer 31 and the second intermediate layer 32, which are the intermediate layer 13, are disposed to sandwich the pair of conductive layers 15, 15, and have insulating properties.

[0038] The light-controlling layer 14 is opaque when no voltage is applied, and is transparent through light control when a voltage is applied via the pair of conductive layers 15, 15. The light-controlling layer 14 may be configured to be transparent when no voltage is applied, and opaque when a voltage is applied.

[0039] The light-controlling layer 14 is configured so that, for example, when the haze value is set to 10% or less, a voltage of 30 V or more is applied to it. With this configuration, the light-controlling layer 14 in the laminated glass 10 can satisfactorily increase the transparency and can properly exhibit the light-controlling function.

[0040] The thickness of the switchable layer 14 is preferably 20 μm or more and 150 μm or less. When the thickness of the switchable layer 14 is 20 μm or more and 150 μm or less, the laminated glass 10 can ensure an appropriate switchable function in the switchable layer 14 while reducing the weight of the switchable layer 14.

[0041] In this embodiment, the laminated glass 10 includes a pair of glass plates 11, 12, of which the first glass plate 11 (an example of an interior glass plate) is disposed on the interior side of the vehicle, and the second glass plate 12 (an example of an exterior glass plate) is disposed on the exterior side of the vehicle. The pair of glass plates 11, 12 are disposed so as to sandwich an intermediate layer 13. Specifically, the pair of glass plates 11, 12 face each other, and the intermediate layer 13, the light control layer 14, and a pair of conductive layers 15, 15 are positioned between the pair of glass plates 11, 12. The pair of glass plates 11, 12 are fixed together with the intermediate layer 13, the light control layer 14, etc. sandwiched therebetween.

[0042] Known glass plates can be used for the first glass plate 11 and the second glass plate 12, and they can be made of common soda-lime glass. An example of the composition of soda-lime glass is shown below.

[0043] (soda lime 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 RO: 13 to 15 mass% (R is an alkali metal) Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.08-0.14 mass%

[0044] The laminated glass 10 has a hue maintaining layer K that maintains the hue of the intermediate layer 13. In this embodiment, the hue maintaining layer K is formed by the first glass plate 11 or a pair of glass plates 11, 12. The laminated glass 10 maintains the hue of the intermediate layer 13 visible from inside the vehicle by the hue maintaining layer K formed by at least the first glass plate 11 (the glass plate on the vehicle interior side) of the pair of glass plates 11, 12. This allows the laminated glass 10 to be used while properly enjoying the hue of the intermediate layer 13 in the vehicle interior space without the hue of the intermediate layer 13 being obstructed by at least the first glass plate 11.

[0045] When the hue maintaining layer K is composed only of the first glass plate 11, it is preferable that the chromaticity of the hue maintaining layer K (first glass plate 11), calculated by observation from inside the room, in the chromaticity represented on the CIE L*a*b* chromaticity coordinate diagram conforming to IS Z8781-4 (2013), is a* between -6.0 and 6.0, and b* between -5.0 and 5.0.

[0046] In this embodiment, when the light-controlling layer 14 of the laminated glass 10 is in a transmitting state in which it transmits visible light, the hue maintaining layer K can also be formed of a pair of glass plates 11, 12. In this case, in the chromaticity represented on the CIE L*a*b* chromaticity coordinate diagram conforming to JIS Z8781-4 (2013), the chromaticity of the hue maintaining layer K (the pair of glass plates 11, 12) calculated by observation from the indoor side is preferably a* between -10.0 and 6.5, and b* between -3.5 and 6.5.

[0047] When the chromaticity of the hue maintaining layer K (the first glass plate 11 or the pair of glass plates 11, 12) is within the above range, the laminated glass 10 can properly maintain the hue of the intermediate layer 13 visible from inside the vehicle by the hue maintaining layer K.

[0048] Second Embodiment In the second embodiment, as shown in FIG. 3, the laminated glass 10 further includes a light-shielding layer 40 that has a visible light transmittance of 70% or more and absorbs or reflects light of wavelengths other than visible light. In the example shown in FIG. 3, the laminated glass 10 includes a light-shielding layer 40 on the vehicle-inside plate surface 11a of the first glass plate 11. The light-shielding layer 40 is made of a Low-E film 41. The other configurations are the same as those of the first embodiment. Here, the Low-E film 41 is made of a metal film. In order to achieve both infrared reflectance and visible light transmittance, the thickness of the Low-E film 41 (low-emissivity film) is preferably about 1 to 5000 nm, more preferably about 10 to 3000 nm. The Low-E film 41 is preferably made of a multilayer structure in which two or more layers selected from a metal layer, a metal oxide layer, a metal nitride layer, and a metal oxynitride layer are laminated. A suitable example of the metal layer is a silver layer. Suitable examples of the metal oxide layer include a tin oxide layer, a titanium oxide layer, or a zinc oxide layer. Suitable examples of the metal nitride layer include silicon nitride. Suitable examples of the metal oxynitride layer include silicon oxynitride. The light shielding layer 40 is not limited to the Low-E film 41, and may be any thin film that has a visible light transmittance of 70% or more and absorbs or reflects light of wavelengths other than visible light.

[0049] If the laminated glass 10 further includes a light-shielding layer 40 that absorbs or reflects light of wavelengths other than visible light, as in the present embodiment, the laminated glass 10 can be provided with a heat insulating effect or a heat shielding effect, thereby improving the functionality of the laminated glass 10.

[0050] Furthermore, if the light-shielding layer 40 includes the Low-E film 41, the laminated glass 10 can properly exhibit the heat insulating effect or heat shielding effect due to the light-shielding layer 40. Since the light-shielding layer 40 transmits visible light, the hue of the intermediate layer 13 can be properly utilized in the vehicle interior space. Furthermore, if the Low-E film 41 included in the light-shielding layer 40 is provided on the vehicle interior side plate surface 11a of the first glass sheet 11, the Low-E film 41 can enhance the heat insulating effect of the laminated glass 10.

[0051] Third Embodiment In the third embodiment, the second intermediate layer 32 is colored, as shown in Fig. 4. The other configurations are the same as those of the first embodiment.

[0052] As in the present embodiment, the intermediate layer 13 colors the second intermediate layer 32 other than the photochromic layer 14 of the light control section 20, so that the laminated glass 10 can color the intermediate layer 13 by using one or both of the coloring by the photochromic layer 14 and the coloring by the second intermediate layer 32 other than the photochromic layer 14. This allows the laminated glass 10 to use various coloring forms, and increases the degree of freedom in changing the color tone of the vehicle interior space.

[0053] In this embodiment, the hue maintaining layer K can be composed of only the first glass plate 11. In this case, the chromaticity of the hue maintaining layer K calculated by observation from the indoor side is preferably such that a* is -6.0 or more and 6.0 or less, and b* is -5.0 or more and 5.0 or less, in the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram conforming to JIS Z8781-4 (2013). It is more preferable that the first glass plate 11 has a* of -3.0 or more and 3.0 or less, and b* of -3.0 or more and 3.0 or less, in the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram.

[0054] When the chromaticity of the first glass plate 11 (hue maintaining layer K) is within the above range, the laminated glass 10 can properly maintain the hue of the intermediate layer 13 visible from inside the vehicle through the first glass plate 11.

[0055] [Fourth embodiment] In the fourth embodiment, the first intermediate layer 31 and the second intermediate layer 32 are colored, as shown in Fig. 5. The other configurations are the same as those of the first embodiment.

[0056] As in the present embodiment, the intermediate layer 13 colors the second intermediate layer 32 and the first intermediate layer 31 other than the photochromic layer 14 of the light control section 20, so that the laminated glass 10 can color the intermediate layer 13 by using one or both of the coloring by the photochromic layer 14 and the coloring by the first intermediate layer 31 and the second intermediate layer 32 other than the photochromic layer 14. This allows the laminated glass 10 to use various coloring forms, and increases the degree of freedom in changing the color tone of the vehicle interior space.

[0057] Fifth embodiment In the fifth embodiment, as shown in Fig. 6, the laminated glass 10 has a colored light control layer 14. The second glass sheet 12 is also colored. Therefore, in this embodiment, only the first glass sheet 11 functions as a hue maintaining layer K that maintains the hue of the intermediate layer 13. The other configurations are the same as those of the first embodiment.

[0058] In this embodiment, the hue maintaining layer K is formed by the first glass plate 11. In this manner, the laminated glass 10 can be configured such that at least the first glass plate 11 (the glass plate on the vehicle interior side) of the pair of glass plates 11, 12 maintains the hue of the intermediate layer 13 that is visible from inside the vehicle. This allows the laminated glass 10 to be used while appropriately enjoying the hue of the intermediate layer 13 in the vehicle interior space without the hue of the intermediate layer 13 being obstructed by the first glass plate 11.

[0059] Sixth Embodiment In the sixth embodiment, as shown in Fig. 7, the laminated glass 10 has a colored intermediate layer 13 formed by a single layer. In the example shown in Fig. 7, a pair of glass plates 11, 12 are configured to function as a hue maintaining layer K that maintains the hue of the intermediate layer 13. Note that in the example shown in Fig. 7, only the first glass plate 11 may function as the hue maintaining layer K.

[0060] [Example] In the following, the chromaticity of each of the glasses A to E shown in Table 1 was measured based on the CIE L*a*b* chromaticity coordinate diagram with a thickness converted to 2 mm. Glass A has a grayish color, glass B has a light greenish color, glass C is transparent, glass D has a dark greenish color, and glass E has a dark yellowish color. Here, glass A is an example of privacy glass that is placed on the side or rear of the rear seat of a vehicle.

[0061] [Table 1]

[0062] Table 1 and FIG. 8 show the metal components contained in each glass and the measurement results of chromaticity based on the CIE L*a*b* chromaticity coordinate diagram for Glass A to Glass E. The total amount of Fe2O3 is the total amount of iron oxide when it is assumed that FeO and Fe2O3 are all present as Fe2O3, taking into consideration that both FeO and Fe2O3 exist as iron oxide in soda glass. According to Table 1 and FIG. 8, Glass A, Glass C, and Glass D all had a* values ​​in the range of -6.0 to 6.0, and b* values ​​in the range of -5.0 to 5.0. On the other hand, Glass B had a* values ​​smaller than -6.0 and outside the range of -6.0 to 6.0, and b* values ​​larger than 5.0 and outside the range of -5.0 to 5.0. Furthermore, for Glass E, a* was within the range of -6.0 or more and 6.0 or less, but b* was greater than 5.0, falling outside the range of -5.0 or more and 5.0 or less. This demonstrates that for the single glass (first glass plate 11), Glass A, Glass C1, Glass C2, and Glass D are suitable for the hue maintaining layer K.

[0063] Since glass A is a privacy glass, looking at glass other than glass A, it is preferable that the hue maintaining layer K contains 100 ppm or less of CO3O4 and 5 ppm or less of Se, as in glasses C1, C2 and D.

[0064] [Laminated Glass] Next, for Glasses A to E shown in Table 1, the thickness was converted to 2 mm, and chromaticity was measured based on the CIE L*a*b* chromaticity coordinate diagram for each of the laminated glasses, in which two pieces were used for the pair of glass plates 11 and 12. Five laminated glasses, laminated glasses F to J shown in Table 2 below, were used as the laminated glasses. Note that for the intermediate layer, PVB film 7018 (manufactured by Sekisui Chemical Co., Ltd.) was used as a common intermediate layer for all of laminated glasses F to J.

[0065] [Table 2]

[0066] The measurement results of chromaticity based on the CIE L*a*b* chromaticity coordinate diagram for the laminated glass F to the laminated glass J are shown in Table 2 and FIG. 9. The laminated glass F, the laminated glass G, and the laminated glass H all had a* values ​​in the range of -10.0 to 6.5, and b* values ​​in the range of -3.5 to 6.5. On the other hand, the laminated glass I and the laminated glass J all had a* values ​​smaller than -10.0, outside the range of -10.0 to 6.5, and b* values ​​larger than 6.5, outside the range of -3.5 to 6.5. This shows that the laminated glass F, the laminated glass G, and the laminated glass H are suitable for the hue maintaining layer K for the laminated glass (the pair of glass plates 11, 12).

[0067] The first glass plate 11 may be made of soda-lime glass specified by the following color component functions Fa, Fb instead of the chromaticities a*, b* based on the CIE L*a*b* chromaticity coordinate diagram.

[0068] The color component function Fa is correlated with a* in the chromaticity shown on the CIE L*a*b* chromaticity coordinate diagram. The color component function Fa is calculated based on the total amount of Fe2O3, TiO2, and Se contained in Glasses A to E. Define Fa = -3.5 × [Fe2O3 (wt%)] -1.5 × [TiO2 (wt%)] + 0.20 × [Se (ppm)].

[0069] In addition, the color component function Fb is correlated with b* in the chromaticity shown on the CIE L*a*b* chromaticity coordinate diagram, and the color component function Fb is calculated based on the total amount of Fe2O3, TiO2, Co3O4, and Se contained in Glass A to Glass E as follows: Fb = [Total amount of Fe2O3 (wt%)] + 4 × [TiO2 (wt%)] - 43 × 10 -4 ×〔Co3O4(ppm)〕+0.4×10 ―4 × [Se(ppm)].

[0070] The first glass plate 11 is preferably made of soda-lime glass that satisfies −9≦Fa≦1 and −5≦Fb≦10 when the color component functions Fa and Fb are defined as above.

[0071] In the above embodiment, for glass C1, the color component functions Fa and Fb are: Fa=-3.5×(0.6)-1.5×(0.5)+0.20×(0)=-2.9 Fb = (0.6) + 4 × (0.5) - 43 × 10 -4 The result is (0) + 0.4 × (0) = 2.6. For glass D, the color component functions Fa and Fb are as follows: Fa=-3.5×(0.1)-1.5×(0)+0.20×(0)=-0.4 Fb = (0.1) + 4 × (0) - 43 × 10 ―4 ×(0)+0.4×10 ―4 ×〔0〕=0.1. Therefore, glass C1 and glass D satisfy −9≦Fa≦1 and −5≦Fb≦10. Similarly, glass C2 also satisfies the above formulas.

[0072] On the other hand, in the above embodiment, for glass B, the coloring component functions Fa and Fb are as follows: Fa=-3.5×(2.9)-1.5×(1.6)+0.20×(0)=-12.6 Fb = (2.9) + 4 × (1.6) - 43 × 10 -4 ×(300)+0.4×10 -4 ×(0)=8.0. In addition, for glass E, the color component functions Fa and Fb are as follows: Fa=-3.5×(1.6)-1.5×(2.7)+0.20×(30)=-3.7 Fb = (1.6) + 4 × (2.7) - 43 × 10 -4 ×(350)+0.4×10 -4 ×(30)=10.9. Therefore, glass B and glass E do not satisfy −9≦Fa≦1 and −5≦Fb≦10.

[0073] In the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram, a* indicates a chromaticity that is reddish when it is positive and greenish when it is negative. Also, b* indicates a chromaticity that is yellowish when it is positive and bluish when it is negative. When the first glass plate 11 is made of soda glass and contains a large amount of Fe2O3 or TiO2, a* increases on the negative side and becomes greenish, and b* increases on the positive side and becomes yellowish. Therefore, among the chromaticities shown in the CIE L*a*b* chromaticity coordinate diagram, the coloring component function Fa that is correlated with a* and the coloring component function Fb that is correlated with b* are proportional to a* and b*, respectively, by defining the coefficients of each component as described above. Therefore, if the first glass sheet 11 is made of soda glass and Fa and Fb fall within the above ranges, the first glass sheet 11 can have a* and b* within a predetermined range in chromaticity represented on the CIE L*a*b* chromaticity coordinate diagram, thereby enabling the laminated glass 10 to properly maintain the hue of the intermediate layer 13 visible from inside the vehicle.

[0074] [Other embodiments] (1) In the laminated glass 10, the first glass plate 11 (hue maintaining layer K) may be made of soda lime glass having a total content of Fe2O3 of 1.2 wt% or less and TiO2 of 0.5 wt% or less. When the first glass plate 11 is made of soda lime glass and contains a large amount of Fe2O3 or TiO2, in the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram, a* increases toward the negative side, resulting in greenish hues, and b* increases toward the positive side, resulting in yellowish hues. On the other hand, as in this embodiment, if the first glass plate 11 is made of soda lime glass having Fe2O3 of 1.2 wt% or less and TiO2 of 0.5 wt% or less, a* and b* are small, resulting in suppressed color tone. As a result, the laminated glass 10 can appropriately maintain the hue of the intermediate layer 13 visible from inside the vehicle.

[0075] (2) In the case of the soda glass described in (1), the first glass plate 11 (hue maintaining layer K) may further contain Co3O4 of 100 ppm or less and Se of 5 ppm or less. When the first glass plate 11 is made of soda glass and contains a large amount of Co3O4, the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram is such that b* is increased on the negative side and the color becomes greenish. When the first glass plate 11 is made of soda glass and contains a large amount of Se, the chromaticity shown in the CIE L*a*b* chromaticity coordinate diagram is such that a* is increased on the positive side and the color becomes reddish, and b* is increased on the positive side and the color becomes yellowish. On the other hand, when the first glass plate 11 (hue maintaining layer K) contains Co3O4 of 100 ppm or less and Se of 5 ppm or less as in this embodiment, the color tone change due to a* and b* is suppressed. This enables the laminated glass 10 to properly maintain the hue of the intermediate layer 13 that is visible from inside the vehicle.

[0076] (3) In the laminated glass 10, the pair of glass plates 11, 12 may be made of soda-lime glass having the same composition. If the pair of glass plates 11, 12 are made of soda-lime glass having the same composition, a common glass plate can be used as the pair of glass plates 11, 12, and therefore the laminated glass 10 can be easily constructed. [Industrial Applicability]

[0077] The present invention is widely applicable to laminated glass for vehicle roofs. [Explanation of symbols]

[0078] 1: Vehicle 2: Roof 10: Laminated glass (laminated glass for vehicle roofs) 11: First glass pane (inside glass pane) 11a: Panel surface inside the car 12: Second glass pane (outer glass pane) 13: Middle class 14: Light control layer 15: Conductive layer 31: 1st intermediate layer (adhesive layer) 32: Second intermediate layer (supporting base material) 40: Light shielding layer 41: Low-E film K: Hue maintenance layer

Claims

1. A laminated glass for a vehicle roof used for at least a part of a roof of a vehicle, comprising: A pair of glass plates, an exterior glass plate and an interior glass plate; an intermediate layer disposed between the pair of glass sheets; The intermediate layer is configured to contain a color conversion material, At least the vehicle-interior glass sheet of the pair of glass sheets maintains a hue of the intermediate layer that is visible from inside the vehicle.

2. 2. The laminated glass for a vehicle roof according to claim 1, wherein the intermediate layer includes a light control portion including a light control layer capable of adjusting light transmittance by application of a voltage, a pair of conductive layers sandwiching the light control layer, and a pair of supporting substrates sandwiching the pair of conductive layers.

3. 2. The laminated glass for vehicle roofs according to claim 1, further comprising a light-shielding layer that absorbs or reflects light of wavelengths other than visible light.

4. The laminated glass for vehicle roofs according to claim 3 , wherein the light-shielding layer includes a Low-E film.

5. 5. The laminated glass for a vehicle roof according to claim 4, wherein the Low-E film included in the light-shielding layer is provided on an interior side surface of the interior glass sheet.

6. 2. The laminated glass for a vehicle roof according to claim 1, wherein the vehicle interior glass sheet has a chromaticity represented in a CIE L*a*b* chromaticity coordinate diagram of a* being equal to or greater than −6.0 and equal to or less than 6.0, and b* being equal to or greater than −5.0 and equal to or less than 5.

0.

7. 3. The laminated glass for vehicle roofs according to claim 2, wherein, when the light control layer is in a transmitting state in which it transmits visible light, in chromaticity represented in a CIE L*a*b* chromaticity coordinate diagram, a* is −10.0 or more and 6.5 or less, and b* is −3.5 or more and 6.5 or less.

8. The glass plate on the inside of the vehicle is made of Fe. ２ O ３ The total amount of TiO is 1.2 wt% or less. ２ 8. The laminated glass for a vehicle roof according to claim 1, which is made of soda lime glass having a viscosity of 0.5 wt % or less.

9. The glass sheet on the inside of the vehicle further comprises Co. ３ O ４ 9. The laminated glass for vehicle roofs according to claim 8, which is made of soda lime glass having a Mo content of 100 ppm or less and a Se content of 5 ppm or less.

10. 8. The laminated glass for a vehicle roof according to claim 1, wherein the pair of glass sheets are made of soda-lime glass having the same composition.

11. The interior glass sheet of the vehicle is A color component function Fa correlated with a* and a color component function Fb correlated with b* of the chromaticity represented in the CIE L*a*b* chromaticity coordinate diagram are calculated by dividing the Fe ２ O ３ The total amount of TiO ２ , Co ３ O ４ , based on the amount of Se, Fa=-3.5×[Fe ２ O ３ (wt%))]−1.5×[TiO ２ (wt%) + 0.20 × [Se (ppm)], and Fb = [Fe ２ O ３ (wt%))] + 4 × [TiO ２ (wt%)] -43×10 －４ × [Co ３ O ４ (ppm)]+0.4×10 －４ ×[Se (ppm)] When we define 8. The laminated glass for a vehicle roof according to claim 1, which is made of soda lime glass that satisfies -9≦Fa≦1 and -5≦Fb≦10.

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