Laminated glass

Abstract

The present disclosure provides laminated glass capable of well propagating light inside the laminated glass provided with a light-absorbing intermediate layer. This laminated glass is provided with: a first glass plate (11) having a first main surface (21) and a second main surface (22); a second glass plate (12) having a third main surface (23) and a fourth main surface (24); a light-absorbing intermediate layer (13) disposed between the first glass plate (11) and the second glass plate (12); and a light scattering region (15) disposed closer to the fourth main surface (24) than the light-absorbing intermediate layer (13). The light scattering region (15) scatters light (31) incident from the light source toward the fourth main surface (24). The refractive index difference between the light-absorbing intermediate layer (13) and a member in contact with the light-absorbing intermediate layer (13) on the fourth main surface (24) side is 0.05 or more, the visible light reflectance measured from the fourth main surface (24) side is 15% or less, and the visible light transmittance measured from the fourth main surface (24) side in a region other than the light scattering region (15) is 30% or less.

Description

laminated glass Technical Field

[0001] This disclosure relates to laminated glass. Background Technology

[0002] Laminated glass, made by joining two panes of glass with an interlayer, is used for windows in vehicles or buildings. Recently, a technology is being developed that uses light sources such as light-emitting diodes (LEDs) to guide light into the interior of the laminated glass from its ends and uses a scattering layer on the laminated glass to extract the light.

[0003] Patent document 1 discloses a technology related to vehicle assembly glass in which LEDs are arranged on the end face of the inner glass panel of a vehicle to guide light into the laminated glass and emit light.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2017-504938 Summary of the Invention

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

[0008] As described above, a technology is being developed that uses a light source such as an LED to guide illumination light from the end of laminated glass into the interior of the laminated glass, and uses a scattering layer provided on the laminated glass to extract the light to the outside of the laminated glass. On the other hand, some laminated glasses use a light-absorbing interlayer as the interlayer to reduce the proportion of sunlight entering the vehicle from the outside. When using an LED or the like to guide illumination light into such a laminated glass with a light-absorbing interlayer, there is a problem that the introduced illumination light is absorbed by the light-absorbing interlayer, causing the illumination light to not propagate to a distance within the laminated glass.

[0009] In view of the above-mentioned technical problems, the purpose of this disclosure is to provide a laminated glass that enables light to propagate well inside the laminated glass having a light-absorbing interlayer.

[0010] means of solving technical problems

[0011] One type of laminated glass disclosed herein is as follows.

[0012] [1]

[0013] A laminated glass comprises: a first glass plate having a first main surface and a second main surface; a second glass plate having a third main surface and a fourth main surface; a light-absorbing interlayer disposed between the first glass plate and the second glass plate; and a light-scattering region disposed further from the light-absorbing interlayer than the fourth main surface, wherein the second main surface and the third main surface face each other; the light-scattering region scatters light incident from a light source toward the fourth main surface; the refractive index difference between the light-absorbing interlayer and a member in contact with the light-absorbing interlayer on the fourth main surface is 0.05 or more; the visible light reflectance measured from the fourth main surface is 15% or less; and the visible light transmittance measured from the fourth main surface in areas other than the light-scattering region is 30% or less.

[0014] [2]

[0015] As described in [1], the laminated glass wherein the component in contact with the light-absorbing interlayer on the fourth main surface is a low-refractive-index interlayer.

[0016] [3]

[0017] As described in [1], the laminated glass wherein the component in contact with the light-absorbing intermediate layer on the fourth main surface is the second glass plate.

[0018] [4]

[0019] As described in [2], the laminated glass, wherein the low refractive index interlayer comprises at least one selected from polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin and cyclic olefin polymer, or comprises an optical adhesive material based on acrylic, silicone, epoxy or urethane acrylate.

[0020] [5]

[0021] The laminated glass as described in any one of [1] to [4], wherein the light-absorbing interlayer comprises at least one selected from polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin, and cyclic olefin polymer.

[0022] [6]

[0023] The laminated glass as described in any one of [1] to [5], wherein the visible light transmittance of the light-absorbing intermediate layer is less than 30%.

[0024] [7]

[0025] Laminated glass as described in any one of [1] to [6], wherein the light-absorbing interlayer is composed of a pigmented resin material.

[0026] [8]

[0027] The laminated glass as described in any one of [1] to [7], wherein the refractive index difference at a wavelength of 630 nm is greater than 0.05.

[0028] [9]

[0029] The laminated glass as described in any one of [1] to [8], wherein the visible light transmittance of the second glass plate is above 85%.

[0030]

[10]

[0031] The laminated glass as described in any one of [1] to [9], wherein the light scattering region is formed on the surface of the third main surface of the second glass plate or the fourth main surface of the light-absorbing intermediate layer.

[0032]

[11]

[0033] The laminated glass as described in any one of [1] to

[10] , wherein the refractive index difference is less than 0.2.

[0034]

[12]

[0035] The laminated glass as described in any one of [1] to

[11] , wherein the visible light reflectance measured from the fourth main surface side is 3% or more.

[0036] Invention Effects

[0037] According to this disclosure, a laminated glass capable of allowing light to propagate well within the interior of a laminated glass having a light-absorbing interlayer can be provided. Attached Figure Description

[0038] Figure 1 is a cross-sectional view illustrating a structural example of the laminated glass in Embodiment 1.

[0039] Figure 2 is a cross-sectional view illustrating a structural example of the laminated glass in Embodiment 2.

[0040] Figure 3 is a cross-sectional view illustrating a structural example of the laminated glass in Embodiment 3. Detailed Implementation

[0041] <Summary of this disclosure>

[0042] The laminated glass disclosed herein comprises: a first glass plate having a first main surface and a second main surface; a second glass plate having a third main surface and a fourth main surface; a light-absorbing interlayer disposed between the first glass plate and the second glass plate; and a light-scattering region disposed further along the fourth main surface than the light-absorbing interlayer. The light-scattering region scatters light incident from a light source toward the fourth main surface. Furthermore, the refractive index difference between the light-absorbing interlayer and the member in contact with the light-absorbing interlayer on the fourth main surface is 0.05 or more, the visible light reflectance measured from the fourth main surface is 15% or less, and the visible light transmittance measured from the fourth main surface in areas other than the light-scattering region is 30% or less.

[0043] In one embodiment of this disclosure, the component in contact with the light-absorbing intermediate layer on the fourth principal surface is a low-refractive-index intermediate layer, and the structure in this case corresponds to the structure shown in Figures 1 and 2 of this application.

[0044] In another embodiment of this disclosure, the component in contact with the light-absorbing intermediate layer on the fourth main surface is a second glass plate, and the structure in this case corresponds to the structure shown in FIG3 of this application.

[0045] The specific structure of the laminated glass disclosed herein will be described in detail below.

[0046] <Implementation Method 1>

[0047] Figure 1 is a cross-sectional view illustrating a structural example of the laminated glass according to Embodiment 1. As shown in Figure 1, the laminated glass 1a of this embodiment includes: a first glass plate 11 having a first main surface 21 and a second main surface 22; a second glass plate 12 having a third main surface 23 and a fourth main surface 24; a light-absorbing interlayer 13 and a low-refractive-index interlayer 14 disposed between the first glass plate 11 and the second glass plate 12; and a light-scattering region 15 disposed on the fourth main surface 24 side of the low-refractive-index interlayer 14. The second main surface 22 of the first glass plate 11 and the third main surface 23 of the second glass plate 12 are disposed facing each other. Furthermore, the light-absorbing interlayer 13, the low-refractive-index interlayer 14, and the light-scattering region 15 are configured to be sandwiched between the second main surface 22 of the first glass plate 11 and the third main surface 23 of the second glass plate 12.

[0048] The laminated glass 1a of this embodiment can be used, for example, as a vehicle window. Vehicle windows include, for example, sunroofs, windshields, rear windows, side windows, and recessed windows. The laminated glass 1a is suitable for use as a sunroof, rear window, rear side window, or recessed window in a vehicle, and is particularly suitable for sunroofs.

[0049] The laminated glass 1a in this embodiment can be planar or curved. Alternatively, it can be a shape that combines both planar and curved surfaces. The first glass plate 11 and the second glass plate 12 can be flat or curved plates, but it is preferable that at least one is curved, as this makes it easier to ensure the strength of the laminated glass; more preferably, both are curved. The curved plate can be a single-curved shape that bends in one direction, or a three-dimensional shape that bends in two or more directions. For example, a three-dimensional shape can be a multi-curved shape that bends in two orthogonal directions. In the following examples, the case where both the first glass plate 11 and the second glass plate 12 are made of flat plates will be described, but the same description can also be applied when at least one is made of a curved plate.

[0050] The outer edge shape of the first glass plate 11 and the second glass plate 12 when viewed from above can be any shape, such as preferably a rectangle, trapezoid, or triangle.

[0051] The first glass panel 11 includes a first main surface 21 opposite to the light-absorbing intermediate layer 13 and a second main surface 22 opposite to the light-absorbing intermediate layer 13. The second glass panel 12 includes a third main surface 23 opposite to the low-refractive-index intermediate layer 14 and a fourth main surface 24 opposite to the low-refractive-index intermediate layer 14. For example, the first main surface 21 of the first glass panel 11 is disposed on the outer side of the vehicle, and the fourth main surface 24 of the second glass panel 12 is disposed on the inner side of the vehicle.

[0052] The first and second glass plates 11 and 12 can be made of, for example, transparent inorganic glass. The first and second glass plates 11 and 12 can be made of, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, quartz glass, etc. Alternatively, the first and second glass plates 11 and 12 can also be made of plexiglass (resin). Plexiglass can be made of, for example, polycarbonate resin, polystyrene resin, aromatic polyester resin, acrylic resin, polyester resin, polyaryl ester resin, condensation polymer of halogenated bisphenol A and ethylene glycol, urethane acrylate resin, halogenated aryl group-containing acrylic resin, etc.

[0053] The thickness of each of the first and second glass plates 11 and 12 is, for example, 0.1 mm to 10 mm. From the viewpoint of resistance to flying stone impacts, 0.3 mm to 3.0 mm is preferred, 1.1 mm to 2.6 mm is more preferred, and 1.7 mm to 2.1 mm is even more preferred. The thicknesses of the first and second glass plates 11 and 12 can be the same or different. For example, the thickness of the first glass plate 11 disposed on the outer side of the vehicle can be made thicker than the thickness of the second glass plate 12 disposed on the inner side of the vehicle. In this way, when the thickness of the first glass plate 11 disposed on the outer side of the vehicle is increased, the strength of the laminated glass 1a is improved against objects flying towards it.

[0054] The light-absorbing interlayer 13 and the low-refractive-index interlayer 14 are configured to be sandwiched between the second main surface 22 of the first glass plate 11 and the third main surface 23 of the second glass plate 12. In other words, the first glass plate 11 and the second glass plate 12 are bonded together using the light-absorbing interlayer 13 and the low-refractive-index interlayer 14. Specifically, when forming the laminated glass 1a, the first glass plate 11, the light-absorbing interlayer 13, the low-refractive-index interlayer 14, and the second glass plate 12 are sequentially stacked, and the stacked body is heated, pressurized, and pressed together to form the laminated glass 1a. The light-scattering region (scattering layer) 15 can be formed, for example, on the main surface of the low-refractive-index interlayer 14 or the main surface of the second glass plate 12, located between the low-refractive-index interlayer 14 and the second glass plate 12, or it can be disposed between the low-refractive-index interlayer 14 and the second glass plate 12 as a component independent of the low-refractive-index interlayer 14 and the second glass plate 12. The light-scattering region (scattering layer) 15 forms a pattern that scatters light. For the region 16 that does not scatter light, the low-refractive-index intermediate layer 14 is directly in contact with the third main surface 23 of the second glass plate 12. The total area of ​​the portions with the light-scattering pattern is, for example, less than 50% of the area of ​​overlap between the first glass plate 11 and the second glass plate 12 in a top view, preferably less than 40%, and more preferably less than 30%. Therefore, the adhesion between the first glass plate 11 and the second glass plate 12 can be ensured.

[0055] A light-absorbing interlayer 13 is disposed between the first glass plate 11 and the low-refractive-index interlayer 14. The light-absorbing interlayer 13 is an interlayer with light-absorbing function. By using the light-absorbing interlayer 13 as the interlayer of the laminated glass 1a, the proportion of sunlight entering the vehicle from the outside can be reduced. In other words, the light-absorbing interlayer 13 is an interlayer with light-shielding properties. The visible light transmittance of the light-absorbing interlayer 13 is preferably 30% or less, more preferably 20% or less, and even more preferably 15% or less. Furthermore, the refractive index of the light-absorbing interlayer 13 is preferably 1.30 or more and 1.50 or less, more preferably 1.35 or more and 1.45 or less. Unless otherwise stated, the refractive index is the value at 25°C. The thickness of the light-absorbing interlayer 13 is not particularly limited, but is preferably 1.60 mm or less. In addition, the thickness of the light-absorbing intermediate layer 13 is preferably 0.36 mm or more, and can be 0.50 mm or more, 0.76 mm or more, or 0.80 mm or more.

[0056] The light-absorbing intermediate layer 13 can be made of a pigmented resin material. The pigment can be a pigment or the like. The resin material constituting the light-absorbing intermediate layer 13 can be at least one selected from polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin, and cyclic olefin polymer.

[0057] A low-refractive-index interlayer 14 is disposed between the light-absorbing interlayer 13 and the light-scattering region 15 (second glass plate 12). The low-refractive-index interlayer 14 is an interlayer with a refractive index lower than that of the light-absorbing interlayer 13. The low-refractive-index interlayer 14 is usually transparent, but it can also be colored in any color. The refractive index of the low-refractive-index interlayer 14 is preferably 1.30 or higher and 1.50 or lower, more preferably 1.35 or higher and 1.45 or lower. The thickness of the low-refractive-index interlayer 14 is not particularly limited, but is preferably 1.60 mm or lower. In addition, the thickness of the low-refractive-index interlayer 14 is preferably 0.10 mm or higher, and can be 0.15 mm or higher, 0.36 mm or higher, 0.50 mm or higher, 0.76 mm or higher, or 0.80 mm or higher.

[0058] The low-refractive-index interlayer 14 can be made of, for example, a thermoplastic resin. Specifically, the low-refractive-index interlayer 14 can be made of at least one resin material selected from polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin, and cyclic olefin polymer. Alternatively, the low-refractive-index interlayer 14 can also be made of an acrylic, silicone, epoxy, or urethane acrylate optical adhesive (OCA: optically clear adhesive). The low-refractive-index interlayer 14 preferably further contains a plasticizer. As a plasticizer, for example, known compounds contained in conventional laminated glass resin films such as dihexyl adipate (DHA), triethylene glycol di-2-ethylhexanoate (3GO), tetraethylene glycol di-2-ethylhexanoate (4GO), and triethylene glycol di-2-ethylbutyrate (3GH) can be used.

[0059] The refractive index of the low-refractive-index interlayer 14 can be adjusted, for example, by changing the plasticizer content relative to the thermoplastic resin. For example, as described in Japanese Patent Application Publication No. 6-273327, various resin films with known plasticizer contents are prepared in advance, and the refractive index of the resin film is measured using an Abbe refractometer, thereby generating a calibration curve showing the relationship between the refractive index and the plasticizer content. Using this calibration curve, information needed to produce a low-refractive-index interlayer 14 with the desired refractive index can be obtained. However, adjusting the refractive index of the low-refractive-index interlayer 14 is not limited to adjusting the plasticizer dosage; it can also be achieved, for example, by changing the crystallinity of the resin contained in the low-refractive-index interlayer 14. Furthermore, when the low-refractive-index interlayer 14 is constructed using, for example, polyvinyl butyral resin, the refractive index can be reduced by increasing the proportion of acetyl groups.

[0060] The combined thickness of the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14 is preferably 0.76 mm or more and 2.00 mm or less. The light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14 may also be composed of a common resin material.

[0061] In this embodiment, the refractive index difference between the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14 is preferably 0.05 or more, more preferably 0.07 or more, and even more preferably 0.09 or more. Furthermore, the refractive index difference between the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14 is preferably 0.2 or less, more preferably 0.15 or less. If the refractive index difference exceeds 0.2, optical deformation will occur if the interface between the two layers is not highly smooth, posing significant challenges in both forming and lamination techniques. By setting the refractive index difference between the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14 to this range, the amount of light incident on the light-absorbing intermediate layer 13 from the low-refractive-index intermediate layer 14 can be reduced. This reduces the amount of light absorbed by the light-absorbing intermediate layer 13, thus allowing light to propagate further within the laminated glass.

[0062] Furthermore, in this embodiment, the refractive index difference at a wavelength of 630 nm is preferably 0.05 or higher, more preferably 0.06 or higher, even more preferably 0.07 or higher, and even more preferably 0.09 or higher. By setting the refractive index difference at a wavelength of 630 nm within this range, the effect of suppressing in-plane color changes during light guiding is achieved.

[0063] A light-scattering region 15 is disposed between the low-refractive-index interlayer 14 and the second glass plate 12. The light-scattering region 15 scatters light 31 incident from the light source toward the fourth principal surface 24. The light-scattering region 15 forms a light-scattering pattern. For the non-light-scattering region 16, the low-refractive-index interlayer 14 is directly in contact with the third principal surface 23 of the second glass plate 12. For example, the light-scattering region 15 can be disposed by forming a light-scattering pattern on the third principal surface 23 of the second glass plate 12. The light-scattering pattern can be formed by physically or chemically etching the glass plate to roughen its surface, or by printing a scattering material containing inorganic or organic particles onto the glass plate surface.

[0064] Light 31, introduced from a light source such as an LED (not shown), propagates along the in-plane direction of the laminated glass 1a at the end of the laminated glass 1a. That is, in this embodiment, since the refractive index difference between the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14 is 0.05 or greater, most of the light 31 undergoes suitable total internal reflection at the interface between the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14. Furthermore, most of the light 31 also undergoes suitable total internal reflection at the fourth principal surface 24 of the second glass plate 12. Thus, the light 31 propagates within the second glass plate 12 and the low-refractive-index intermediate layer 14. At this time, a portion of the light 31 is scattered by the light-scattering region 15 and extracted from the fourth principal surface 24 side of the laminated glass 1a.

[0065] In addition, in this embodiment, since the light source and light scattering region 15 are provided on the side of the fourth main surface 24, which is closer to the light-absorbing intermediate layer 13 than the light-absorbing intermediate layer 13, it is possible to suppress the light from being absorbed and attenuated by the light-absorbing intermediate layer 13.

[0066] In the laminated glass 1a of this embodiment, the visible light reflectance measured from the fourth main surface 24 side is preferably 15% or less, more preferably 10% or less. Furthermore, the visible light reflectance measured from the fourth main surface 24 side is preferably 3% or more, more preferably 5% or more. Here, visible light reflectance refers to the measured value at the portion where no light-scattering pattern is formed (i.e., the region 16 where light is not scattered). By setting the visible light reflectance measured from the fourth main surface 24 side to this range (i.e., reducing visible light reflectance), the user can easily see the light scattered by the light-scattering region 15.

[0068] That is, when the light-absorbing intermediate layer 13 is provided, the laminated glass 1a becomes darker, and light inside the vehicle is reflected. Therefore, it is difficult for the user to see the light emitted from the fourth main surface 24. In contrast, in this embodiment, since the visible light reflectance measured from the fourth main surface 24 side is reduced, the user can easily see the light emitted from the fourth main surface 24.

[0069] Furthermore, in the laminated glass 1a of this embodiment, the visible light transmittance measured from the fourth main surface 24 side in the region 16 outside the light scattering region 15 is preferably 30% or less, more preferably 20%. By setting the visible light transmittance measured from the fourth main surface 24 side to this range (i.e., reducing the visible light transmittance), it is possible to prevent light from the outside from entering. Therefore, the user can easily see the light emitted from the fourth main surface 24. Here, the region 16 outside the light scattering region 15 refers to the region where the light scattering region 15 (scattering layer) is not provided, and is the region where a pattern for light scattering is not formed.

[0070] Furthermore, the visible light transmittance of the second glass plate 12 is preferably 85% or higher, more preferably 90%. By setting the visible light transmittance of the second glass plate 12 to this range, it is possible to suppress the absorption and attenuation of light at the second glass plate 12. Moreover, since it is possible to suppress the attenuation of light scattered by the light scattering region 15 as it passes through the second glass plate 12, the user can easily see the light extracted from the fourth main surface 24.

[0071] <Implementation Method 2>

[0072] The structure of the laminated glass in Embodiment 2 will now be described using the cross-sectional view shown in FIG2. The laminated glass 1b of this embodiment shown in FIG2 differs from the laminated glass 1a of Embodiment 1 shown in FIG1 in the position of the light scattering region 15 and the position of the light-introducing region (i.e., the position of the light source). Other than this, since the structure is the same as that of the laminated glass 1a of Embodiment 1 shown in FIG1, the same structural elements are labeled with the same symbols and repeated descriptions are omitted as appropriate.

[0073] As shown in Figure 2, in the laminated glass 1b of this embodiment, a light-scattering region 15 is disposed between the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14. Specifically, the light-scattering region 15 is formed on the surface of the light-absorbing intermediate layer 13 on the side of the fourth principal surface 24, or on the surface of the low-refractive-index intermediate layer 14 on the side of the first principal surface 21. The light-scattering region 15 scatters light 31 incident from the light source toward the fourth principal surface 24. The light-scattering region 15 forms a pattern that scatters light, and for the region 16 that does not scatter light, the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14 are directly in contact. For example, the pattern of scattered light can be a scattering material containing inorganic or organic particles.

[0074] In the laminated glass 1b of this embodiment, light 31 is introduced into the low-refractive-index interlayer 14. The light 31 introduced into the low-refractive-index interlayer 14 propagates in the in-plane direction of the laminated glass 1b. That is, in the laminated glass 1b of this embodiment, since the refractive index difference between the light-absorbing interlayer 13 and the low-refractive-index interlayer 14 is also 0.05 or more, most of the light 31 undergoes suitable total internal reflection at the interface between the light-absorbing interlayer 13 and the low-refractive-index interlayer 14. Furthermore, since the refractive index difference between the second glass plate 12 and the low-refractive-index interlayer 14 is also 0.05 or more, most of the light 31 also undergoes suitable total internal reflection at the interface between the second glass plate 12 and the low-refractive-index interlayer 14 (i.e., the third principal surface 23). Thus, the light 31 propagates inside the low-refractive-index interlayer 14. At this time, a portion of the light 31 is scattered by the light-scattering region 15 and extracted from the fourth principal surface 24 side of the laminated glass 1b.

[0075] In the laminated glass 1b of this embodiment, the same effect as that of the laminated glass 1a of embodiment 1 can also be obtained.

[0076] Alternatively, in the laminated glass 1b shown in Figure 2, light 31 can also be guided into the second glass plate 12 (see Figure 1). In this case, the light 31 guided into the second glass plate 12 propagates inside the second glass plate 12 and the low-refractive-index interlayer 14. At this time, a portion of the light 31 is scattered by the light scattering region 15 and extracted from the fourth main surface 24 side of the laminated glass 1b.

[0077] <Implementation Method 3>

[0078] The structural example of the laminated glass of Embodiment 3 will now be described using the cross-sectional view shown in FIG3. The laminated glass 1c of Embodiment 3 shown in FIG3 differs from the laminated glass 1a of Embodiment 1 shown in FIG1 in that it does not have a low-refractive-index interlayer 14. For other structures, since they are the same as those of the laminated glass 1a of Embodiment 1 shown in FIG1, the same structural elements are labeled with the same symbols and repeated descriptions are omitted as appropriate.

[0079] As shown in Figure 3, in the laminated glass 1c of this embodiment, the light-absorbing interlayer 13 is sandwiched between the second main surface 22 of the first glass plate 11 and the third main surface 23 of the second glass plate 12. In other words, the first glass plate 11 and the second glass plate 12 are bonded together by the light-absorbing interlayer 13.

[0080] A light-scattering region 15 is disposed between the light-absorbing intermediate layer 13 and the second glass plate 12. The light-scattering region 15 scatters light 31 incident from the light source toward the fourth principal surface 24. The light-scattering region 15 forms a light-scattering pattern, and for the region 16 that does not scatter light, the light-absorbing intermediate layer 13 is directly in contact with the third principal surface 23 of the second glass plate 12. For example, the light-scattering region 15 can be disposed by forming a light-scattering pattern on the third principal surface 23 of the second glass plate 12.

[0081] In the laminated glass 1c of this embodiment, the refractive index difference between the light-absorbing interlayer 13 and the second glass plate 12 is preferably 0.05 or more, more preferably 0.07 or more, and even more preferably 0.09 or more. Furthermore, the refractive index difference between the light-absorbing interlayer 13 and the second glass plate 12 is preferably 0.2 or less, more preferably 0.15 or less. By setting the refractive index difference between the light-absorbing interlayer 13 and the second glass plate 12 within this range, the amount of light incident on the light-absorbing interlayer 13 from the second glass plate 12 can be reduced. Therefore, the amount of light absorbed by the light-absorbing interlayer 13 can be reduced, and thus light can propagate to a distance within the laminated glass.

[0082] In the laminated glass 1c of this embodiment, light 31 is introduced into the second glass plate 12. In the laminated glass 1c of this embodiment, since the refractive index difference between the light-absorbing interlayer 13 and the second glass plate 12 is 0.05 or greater, light 31 undergoes total internal reflection at the interface between the light-absorbing interlayer 13 and the second glass plate 12. Furthermore, light 31 also undergoes total internal reflection at the fourth principal surface 24 of the second glass plate 12. Thus, light 31 propagates within the second glass plate 12. At this time, a portion of the light 31 is scattered by the light-scattering region 15 and extracted from the fourth principal surface 24 side of the laminated glass 1c.

[0083] In the laminated glass 1c of this embodiment, the same effect as that of the laminated glass 1a of embodiment 1 can also be obtained.

[0084] Example

[0085] The following describes the embodiments.

[0086] Laminated glass in Examples 1 to 13 was manufactured using the method described below. Tables 1 and 2 show the structures of the laminated glass in Examples 1 to 13.

[0087] <Example 1>

[0088] As an example of laminated glass, a laminated glass having the structure shown in FIG1 was fabricated. Specifically, as the first glass plate 11, a transparent glass with a thickness of 2.0 mm (manufactured by AGC Corporation: refractive index n = 1.52) was prepared. As the light-absorbing interlayer 13, a gray interfilm with a thickness of 0.76 mm (refractive index n = 1.48) was prepared. As the low-refractive-index interlayer 14, a transparent CLEAR interfilm with a thickness of 0.02 mm (refractive index n = 1.45) was prepared. On one main surface of the low-refractive-index interlayer 14, a scattering pattern containing light-scattering particles with a thickness of 0.02 mm was pre-prepared as a light-scattering region 15 (scattering layer). The scattering pattern consists of dots with a diameter of approximately 5 mm scattered at predetermined intervals, covering a total area of ​​less than 30% of the total area of ​​the transparent interfilm. As the second glass plate 12, a high-transmittance glass with a thickness of 2.1 mm (manufactured by AGC Corporation: refractive index n = 1.52) was prepared. In addition, unless otherwise specified, the refractive index in this specification is the refractive index at a wavelength of 589 nm measured at 25°C.

[0089] Then, the first glass plate 11, the light-absorbing intermediate layer 13, the low-refractive-index intermediate layer 14 with the light-scattering region 15 (scattering layer), and the second glass plate 12 are sequentially stacked. This laminate is placed in a vacuum bag and bonded at approximately 70°C to 110°C in a vacuum with a gauge pressure of -65 kPa to -100 kPa. The bonded laminate is then subjected to heating and pressurization in an autoclave at a temperature of 100°C to 150°C and a pressure of 0.6 to 1.3 MPa to produce the laminated glass of Example 1. At this time, the light-scattering region 15 (scattering layer) is located at the interface between the low-refractive-index intermediate layer 14 and the second glass plate 12. In Example 1, a light source is placed at the end of the second glass plate 12, and light 31 is introduced into the second glass plate 12.

[0090] <Example 2>

[0091] As an example of laminated glass, a laminated glass was fabricated in which the light scattering region 15 (scattering layer) of Example 1 was disposed on the fourth main surface 24 of the second glass plate 12. Otherwise, it is the same as the laminated glass of Example 1. That is, the scattering pattern disposed on the fourth main surface 24 of the second glass plate 12 is made of the same material and pattern as the scattering pattern disposed on one main surface of the low refractive index intermediate layer 14 in Example 1.

[0092] <Example 3>

[0093] As the laminated glass of Example 3, a laminated glass having the structure shown in FIG2 was fabricated. Specifically, the same materials as in Example 1 were prepared as the first glass plate 11, the light-absorbing intermediate layer 13, the light-scattering region 15 (scattering layer), the low-refractive-index intermediate layer 14, and the second glass plate 12.

[0094] Then, the first glass plate 11, the light-absorbing intermediate layer 13, the low-refractive-index intermediate layer 14 with the light-scattering region 15 (scattering layer), and the second glass plate 12 are sequentially stacked. The laminate is placed in a vacuum bag and bonded at a temperature of approximately 70°C to 110°C in a vacuum with a gauge pressure of -65 kPa to -100 kPa. The bonded laminate is then subjected to heating and pressurization in an autoclave at a temperature of 100°C to 150°C and a pressure of 0.6 to 1.3 MPa to produce the laminated glass of Example 3. At this time, the light-scattering region 15 (scattering layer) is located at the interface between the light-absorbing intermediate layer 13 and the low-refractive-index intermediate layer 14. In Example 3, a light source is placed at the end of the low-refractive-index intermediate layer 14, and light 31 is introduced into the low-refractive-index intermediate layer 14.

[0095] <Example 4>

[0096] As the laminated glass in Example 4, a high-refractive-index, high-transmittance glass (manufactured by AGC Corporation: 2.1 mm thick) with a refractive index n = 1.58 was manufactured for the second glass plate 12. Otherwise, it is the same as the laminated glass in Example 1.

[0097] <Example 5>

[0098] As an example of laminated glass, a sample was prepared in which a light source was placed at the end of the first glass plate 11 and light was introduced into the first glass plate 11. Otherwise, it is the same as the laminated glass in Example 1.

[0099] <Example 6>

[0100] As the laminated glass of Example 6, a laminated glass with a transparent CLEAR interlayer (thickness 0.76 mm) of refractive index n = 1.50 and a low refractive index interlayer 14 was fabricated. Otherwise, it is the same as the laminated glass of Example 1.

[0101] <Example 7>

[0102] As the laminated glass of Example 7, a laminated glass in which a reflective coating was applied to the fourth main surface 24 of the laminated glass of Example 1 was fabricated. The reflective coating was SiO2 or TiO2. Otherwise, it was the same as the laminated glass of Example 1.

[0103] <Example 8>

[0104] As the laminated glass of Example 8, a laminated glass was manufactured that used gray glass (manufactured by AGC Corporation: thickness 2.0 mm: refractive index n = 1.52) instead of the first glass plate 11 (clear glass) of Example 1, and used a transparent CLEAR interlayer (thickness 0.76 mm: refractive index n = 1.48) instead of the light-absorbing interlayer 13 (gray interlayer) of Example 1. Otherwise, it was the same as the laminated glass of Example 1.

[0105] <Example 9>

[0106] As the laminated glass of Example 9, a laminated glass was fabricated in which the light scattering region 15 (scattering layer) of FIG. 3 is disposed on the fourth main surface 24 of the second glass plate 12. Specifically, the same materials as in Example 1 were prepared for the first glass plate 11, the light-absorbing intermediate layer 13, the second glass plate 12, and the light scattering region 15 (scattering layer). In Example 9, the light scattering region 15 (scattering layer) is disposed on the fourth main surface 24 of the second glass plate 12. The scattering pattern in Example 9 is the same material and pattern as the scattering pattern disposed on one main surface of the low refractive index intermediate layer 14 in Example 1.

[0107] Then, a first glass plate 11, a light-absorbing intermediate layer 13, and a second glass plate 12 with a light-scattering region 15 (scattering layer) are sequentially stacked. The laminate is placed in a vacuum bag and bonded at a temperature of approximately 70°C to 110°C in a vacuum with a gauge pressure of -65 kPa to -100 kPa. The bonded laminate is then subjected to heating and pressurization in an autoclave at a temperature of 100°C to 150°C and a pressure of 0.6 to 1.3 MPa to produce the laminated glass of Example 9. In Example 9, a light source is placed at the end of the second glass plate 12, and light 31 is introduced into the second glass plate 12.

[0108] <Example 10>

[0109] As the laminated glass of Example 10, a laminated glass was fabricated in which the light scattering region 15 (scattering layer) of Example 9 was disposed on the third main surface 23 of the second glass plate 12. Otherwise, it is the same as the laminated glass of Example 9. That is, the scattering pattern disposed on the third main surface 23 of the second glass plate 12 is made of the same material and pattern as the scattering pattern disposed on the fourth main surface 24 of the second glass plate 12 in Example 9.

[0110] <Example 11>

[0111] As an example of laminated glass, a laminated glass with a transparent interlayer (thickness 0.76 mm) having a refractive index of n = 1.47 at a wavelength of 630 nm as the interlayer 14 was fabricated. Otherwise, it is the same as the laminated glass in Example 1.

[0112] <Example 12>

[0113] As an example of laminated glass, a laminated glass with a transparent interlayer (thickness 0.76 mm) having a refractive index of n = 1.43 at a wavelength of 630 nm as the interlayer 14 was fabricated. Otherwise, it is the same as the laminated glass in Example 1.

[0114] <Example 13>

[0115] As an example of laminated glass, a laminated glass with a transparent interlayer (thickness 0.76 mm) having a refractive index of n = 1.49 at a wavelength of 630 nm as the interlayer 14 was fabricated. Otherwise, it is the same as the laminated glass in Example 1.

[0116] <Sample Evaluation>

[0117] Calculate the visible light transmittance, visible light reflectance, refractive index difference (3-point average), refractive index difference at 630nm, and transmittance of the second glass plate (calculated with 2mm) for each laminated glass fabricated as described above.

[0118] Visible light transmittance is the visible light transmittance measured from the fourth principal surface 24 side in the region 16 outside the light scattering region 15 (scattering layer). A spectrophotometer (manufactured by Hitachi, Ltd., UH4150) is used to measure the visible light transmittance. Visible light reflectance is the visible light reflectance measured from the fourth principal surface 24 side. A spectrophotometer (manufactured by Hitachi, Ltd., UH4150) is used to measure the visible light reflectance.

[0119] The refractive index difference (3-point average) was calculated by averaging the refractive indices at wavelengths of 656 nm, 589 nm, and 486 nm. Additionally, the refractive index difference at 630 nm was calculated by the difference between the refractive index of the second glass plate and the refractive index of the adjacent intermediate film. The transmittance of the second glass plate (calculated over 2 mm) was determined using a spectrophotometer.

[0120] In addition, the following evaluation was conducted as evaluation item 1.

[0121] Using a 1 lm LED as the light source, the luminance at a location 100 mm away from the light source in the in-plane direction of the laminated glass is 0.5 cd / m². 2 A score of 1.2 or higher is considered "OK". A score of 0.5 or higher is considered "NG" if the scattering pattern is not clearly visible.

[0122] In addition, as evaluation item 2, the following evaluations 1 to 4 were performed. Evaluation item 2 is the item that evaluates the effect when the refractive index difference at a wavelength of 630nm is greater than or equal to 0.05.

[0123] 1: Even when white light is used as the light source, the light is evenly distributed throughout the entire system.

[0124] 2: Even when any color of RGB is used as the light source, the light will still spread throughout the entire system.

[0125] 3: When using red as the light source, the overall effect is relatively dark.

[0126] 4: Regardless of the color used as the light source, the light cannot travel to it.

[0127] The evaluation results of the laminated glass in Examples 1 to 13 above are shown in Tables 1 and 2. In Tables 1 and 2, the "+light source" marking indicates the location of the light source. For example, the description "high-transmittance glass + light source" in the second glass column of Example 1 indicates that high-transmittance glass was used as the second glass and the light source was configured to allow light to enter the high-transmittance glass.

[0128] Table 1

[0129] Table 2

[0130] <Summary of Results>

[0131] The laminated glass in Examples 1-4 and Examples 9-13 are the laminated glass of the embodiments, and the laminated glass in Examples 5-8 are the laminated glass of the comparative examples. The evaluation results of the laminated glass in Examples 1-13 will be described in detail below.

[0132] In the laminated glass of Examples 1 to 4, the refractive index difference between the light-absorbing interlayer 13 (gray interlayer film) and the low-refractive-index interlayer 14 (transparent interlayer film) is greater than or equal to 0.05. Furthermore, the visible light transmittance measured from the fourth principal surface 24 is less than 30%, and the visible light reflectance measured from the fourth principal surface 24 is less than 15%. Therefore, light propagates well within the laminated glass, and the reflection of light from inside the vehicle onto the laminated glass is suppressed, as well as the influence of light transmitted from outside the vehicle is suppressed. Thus, the user can easily see the light emitted from the fourth principal surface 24, and therefore evaluation item 1 is "OK".

[0133] In Example 5, the light source is positioned at the end of the first glass plate 11, guiding light into it. Therefore, the light does not propagate well within the laminated glass, and evaluation item 1 is "NG". In Example 6, the refractive index difference between the light-absorbing interlayer 13 (gray interlayer film) and the low-refractive-index interlayer 14 (transparent interlayer film) is 0.02. Therefore, the light does not propagate well within the laminated glass, and evaluation item 1 is "NG".

[0134] In the laminated glass of Example 7, the refractive index difference between the light-absorbing interlayer 13 (gray interlayer film) and the low-refractive-index interlayer 14 (transparent interlayer film) is greater than 0.05. However, the light inside the carriage is reflected onto the laminated glass as a picture, reducing the visibility of the scattering pattern. Therefore, evaluation item 1 is "NG". In addition, because a reflective coating is applied to the fourth main surface 24, the visible light reflectivity is as high as 20%.

[0135] In the laminated glass of Example 8, the refractive index difference between the gray glass and the transparent interlayer is greater than 0.05, but the visible light transmittance is as high as 39%. Due to the influence of light passing through from outside the vehicle, the visibility of the scattering pattern decreases. Therefore, evaluation item 1 is "NG".

[0136] In the laminated glass of Examples 9 and 10, the refractive index difference between the light-absorbing interlayer 13 (gray interlayer film) and the second glass plate 12 (high-transmittance glass) is greater than or equal to 0.05. Furthermore, the visible light transmittance measured from the fourth main surface 24 is less than 30%, and the visible light reflectance measured from the fourth main surface 24 is less than 15%. Therefore, light propagates well within the laminated glass, and the reflection of light from inside the vehicle onto the laminated glass can be suppressed, as well as the influence of light transmitted from outside the vehicle can be suppressed. Thus, the user can easily see the light emitted from the fourth main surface 24, and therefore evaluation item 1 is "OK".

[0137] In the laminated glass of Examples 11 to 13, the refractive index difference between the light-absorbing interlayer 13 (gray interlayer film) and the low-refractive-index interlayer 14 (transparent interlayer film) is greater than or equal to 0.05. Furthermore, the visible light transmittance measured from the fourth principal surface 24 is less than 30%, and the visible light reflectance measured from the fourth principal surface 24 is less than 15%. Therefore, light propagates well within the laminated glass, and the reflection of light from inside the vehicle onto the laminated glass can be suppressed, as well as the influence of light transmitted from outside the vehicle can be suppressed. Thus, the user can easily see the light emitted from the fourth principal surface 24, and therefore evaluation item 1 is "OK".

[0138] Focusing on the refractive index difference at a wavelength of 630 nm, the refractive index difference is 0.05 in Example 11 and 0.09 in Example 12. Therefore, the evaluation of item 2 is "2" in Example 11 and "1" in Example 12, both of which are good. However, in Example 13, the refractive index difference at a wavelength of 630 nm is as low as 0.03, so the evaluation of item 2 is "3".

[0139] The present invention has been described above based on the above embodiments, but the present invention is not limited to the structure of the above embodiments, and of course also includes various modifications, alterations and combinations that can be made by those skilled in the art within the scope of the claims of this application.

[0140] This application claims priority based on Japanese Application Special Hoc 2023-171722, filed on October 3, 2023, the entire disclosure of which is incorporated herein by reference.

[0141] Symbol Explanation

[0142] 1a, 1b, 1c Laminated glass

[0143] 11 First Glass Plate

[0144] 12 Second glass plate

[0145] 13 Light-absorbing intermediate layer

[0146] 14 Low-refractive-index intermediate layer

[0147] 15 Light scattering region

[0148] 16. Areas outside the light scattering region

[0149] 21 First Main Page

[0150] 22 Second Main Face

[0151] 23 Third Main Face

[0152] 24 The Fourth Main Face

[0153] 31. Light.

Claims

1. A laminated glass comprising: a first glass plate having a first main surface and a second main surface; a second glass plate having a third main surface and a fourth main surface; a light-absorbing interlayer disposed between the first glass plate and the second glass plate; and a light-scattering region disposed further from the light-absorbing interlayer than the fourth main surface, wherein the second main surface and the third main surface face each other, the light-scattering region scatters light incident from a light source toward the fourth main surface, the refractive index difference between the light-absorbing interlayer and a member in contact with the light-absorbing interlayer on the fourth main surface is 0.05 or more, the visible light reflectance measured from the fourth main surface is 15% or less, and the visible light transmittance measured from the fourth main surface in a region other than the light-scattering region is 30% or less.

2. The laminated glass as described in claim 1, wherein, The component that is in contact with the light-absorbing intermediate layer on the fourth main surface side is a low-refractive-index intermediate layer.

3. The laminated glass as described in claim 1, wherein, The component that is in contact with the light-absorbing intermediate layer on the fourth main surface side is the second glass plate.

4. The laminated glass as described in claim 2, wherein, The low-refractive-index interlayer comprises at least one selected from polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin and cyclic olefin polymer, or comprises an optical adhesive material based on acrylic, silicone, epoxy or urethane acrylate.

5. The laminated glass as described in claim 1 or 2, wherein, The light-absorbing intermediate layer comprises at least one selected from polyvinyl butyral resin, ethylene vinyl acetate copolymer resin, polyurethane resin, ionomer resin, and cyclic olefin polymer.

6. The laminated glass as described in claim 1 or 2, wherein, The visible light transmittance of the light-absorbing intermediate layer is below 30%.

7. The laminated glass as described in claim 1 or 2, wherein, The light-absorbing intermediate layer is composed of a pigmented resin material.

8. The laminated glass as described in claim 1 or 2, wherein, The refractive index difference at a wavelength of 630nm is greater than 0.

05.

9. The laminated glass as described in claim 1 or 2, wherein, The visible light transmittance of the second glass plate is above 85%.

10. The laminated glass as claimed in claim 1 or 2, wherein, The light scattering region is formed on the surface of the third main surface of the second glass plate or the fourth main surface of the light-absorbing intermediate layer.

11. The laminated glass as claimed in claim 1 or 2, wherein, The refractive index difference is below 0.

2.

12. The laminated glass as claimed in claim 1 or 2, wherein, The visible light reflectance measured from the fourth principal surface is above 3%.

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