window glass

Abstract

This technology provides an optical component bonded via an adhesive layer that prevents delamination between the optical component and the glass, even in environments with large temperature fluctuations. [Solution] The window glass comprises a laminated glass having an outer glass plate having a first main surface and a second main surface, an inner glass plate having a third main surface and a fourth main surface, and an interlayer disposed between the second main surface and the third main surface; a light source; a long optical member bonded to the fourth main surface via an adhesive layer for guiding light from the light source to the laminated glass; and a light scattering element provided in the laminated glass or on the fourth main surface for scattering the light, wherein the shear bonding strength between the longitudinal end of the optical member and the fourth main surface is S1, and the shear bonding strength between the central part longitudinally centered above the end and the fourth main surface is S0, satisfying S1 > S0.

Description

Technical Field

[0001] The present disclosure relates to window glass.

Background Art

[0002] As a window glass including a plate-shaped glass and a light source, a configuration is known in which light from the light source is guided into the glass, scattered, and emitted from the main surface of the glass.

[0003] For example, Patent Document 1 discloses a vehicle window glass including a window glass body assembly having an outer window glass body 16 and an inner window glass body 18, and a light source 24 configured to couple light into the inner window glass body 18 that is a light guiding layer, wherein it is described that a rod-shaped input coupling element 28 that couples light from the light source 24 to the light guiding layer is fixed to the inner surface of the window glass body assembly via an adhesive layer 30 (adhesive agent layer).

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] When a window glass having the configuration described in Patent Document 1 is used in an environment with large temperature changes, the adhesive layer that bonds the optical member and the glass cannot follow the volume change (expansion and / or contraction) of the optical member, and peeling may occur between the optical member and the glass plate. When peeling occurs, light from the light source cannot be appropriately guided into the glass, and desired emission from the window glass may not be achieved.

[0006] Accordingly, an aspect of the present disclosure provides a technique capable of preventing peeling between an optical member and glass even when the optical member bonded via an adhesive layer is exposed to an environment with large temperature changes. [Means for solving the problem]

[0007] One aspect of the present disclosure is a window glass comprising: an outer glass plate having a first main surface and a second main surface; an inner glass plate having a third main surface and a fourth main surface; an interlayer disposed between the second main surface and the third main surface; a light source; a long optical member bonded to the fourth main surface via an adhesive layer for guiding light from the light source to the laminated glass; and a light scattering element provided in the laminated glass or on the fourth main surface for scattering the light, wherein the shear bonding strength between the longitudinal end of the optical member and the fourth main surface is S1, and the shear bonding strength between the central part longitudinally centered above the end and the fourth main surface is S0, such that S1 > S0. [Effects of the Invention]

[0008] According to one aspect of this disclosure, delamination between the optical component and the glass can be prevented even when the optical component bonded via an adhesive layer is exposed to an environment with large temperature changes. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view of an example of a window glass according to one embodiment of the present disclosure. [Figure 2] This is a cross-sectional view taken along line II in Figure 1. [Figure 3] This is a cross-sectional view taken along line II-II in the figure. [Figure 4] This is an enlarged view of part III of Figure 3. [Figure 5] This figure corresponds to Figure 4, showing a window glass according to another embodiment of the present disclosure. [Figure 6] This figure corresponds to Figure 4, showing a modified window pane with an end section. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their descriptions may be omitted.

[0011] <Window glass> Figure 1 shows a plan view of a window glass 100 according to one embodiment of the present disclosure. The use of the window glass of the present disclosure is not limited and may be for vehicles such as automobiles and trains or for building applications, but Figure 1 shows a window glass 100 for automobiles as an example. Figure 1 is a view of the window glass 100 for automobiles as seen from the inside of the vehicle. Figure 2 shows a cross-sectional view of line II in Figure 1, and Figure 3 shows a cross-sectional view of line II-II in Figure 2.

[0012] The window glass 100 according to this embodiment may be a roof glass, windshield, side glass, rear glass, etc., but the window glass 100 is preferably used as a roof glass.

[0013] For explanatory purposes, the drawings show coordinate axes including mutually perpendicular x, y, and z directions. Along the main surface of the window glass 100, the longitudinal direction of the window glass 100 is the y direction, the transverse direction is the x direction, and the thickness direction of the window glass 100 is the z direction. If the window glass 100 is a roof glass, the direction from the rear to the front of the vehicle when installed is the +y direction, the direction from left to right when viewed from the front of the vehicle is the +x direction, and the direction from the outside to the inside of the window glass 100 is the +z direction.

[0014] As shown in Figures 1 and 2, the window glass 100 comprises a glass 10, a light source 20, and an optical member 30 that guides light from the light source to the glass 10 and is bonded to one main surface of the glass 10 via an adhesive layer 40.

[0015] As shown in Figures 2 and 3, the glass 10 may be laminated glass. The laminated glass 10 includes an outer glass plate 11 having a first main surface F1 and a second main surface F2, an inner glass plate 12 having a third main surface F3 and a fourth main surface F4, and an interlayer 13 disposed between the second main surface F2 and the third main surface F3.

[0016] The configurations of the vehicle-exterior glass plate 11 and the vehicle-interior glass plate 12 (including the type or composition, thickness, production method and the like of the glass) may be the same or different from each other.

[0017] For the vehicle-exterior glass plate 11 and the vehicle-interior glass plate 12 (hereinafter collectively referred to simply as glass plates), inorganic glass is preferable. Examples of the inorganic glass include soda lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, and borosilicate glass. The molding method for the glass plate made of inorganic glass is not particularly limited, but it is preferable that the glass plate is molded by, for example, a float process. Further, the glass plate may be tempered glass or untempered glass.

[0018] The thicknesses of the vehicle-exterior glass plate 11 and the vehicle-interior glass plate 12 may be the same or different from each other. The thickness of the vehicle-exterior glass plate 11 may be 1.1 mm or more and 3.5 mm or less. Further, the thickness of the vehicle-interior glass plate 12 may be 0.5 mm or more and 2.3 mm or less. Furthermore, the total thickness of the laminated glass 10 may be 2.3 mm or more and 8.0 mm or less.

[0019] The material constituting the interlayer film 13 disposed between the second main surface F2 of the vehicle-exterior glass plate 11 and the third main surface F3 of the vehicle-interior glass plate 12 is not particularly limited, but a thermoplastic resin is preferable. As the material of the interlayer film 13, any thermoplastic resin conventionally used for this application may be used, and examples include plasticized polyvinyl acetal resins, plasticized polyvinyl chloride resins, saturated polyester resins, plasticized saturated polyester resins, polyurethane resins, plasticized polyurethane resins, ethylene-vinyl acetate copolymer resins, ethylene-ethyl acrylate copolymer resins, cycloolefin polymer resins, and ionomer resins. These thermoplastic resins may be used alone or in combination of two or more. Among the above, plasticized polyvinyl acetal resins, particularly polyvinyl butyral resin (PVB), are suitably used. Note that the term "plasticized" above means that the resin is plasticized by addition of a plasticizer.

[0020] The shape of the laminated glass 10, or the shapes of the outer glass plate 11 and inner glass plate 12 included in the laminated glass, is rectangular in the example shown in Figure 1, but is not limited to this shape and may be processed into various shapes. Furthermore, the laminated glass 10 may be curved so as to be convex on the outside of the vehicle. In this case, during the manufacturing process of the laminated glass 10, the outer glass plate 11 and inner glass plate 12 can be bent in one direction or two directions to a desired predetermined curvature by bending.

[0021] The laminated glass 10 may include a light-scattering layer 15 that can scatter light introduced into the laminated glass 10. The presence of the light-scattering layer 15 in the laminated glass 10 allows the introduced light to be scattered by the light-scattering layer 15 and emitted from the main surface of the window glass 100.

[0022] In the examples shown in Figures 2 and 3, the light scattering layer 15 is a pattern that scatters light. That is, light introduced from the light source 20 to the optical member 30 is introduced to the glass plate 12 via the optical member 30. A portion of the light introduced to the glass plate 12 is scattered by the scattering layer 15 and taken out to the outside of the glass plate 12, i.e., into the vehicle. The arrangement of the light scattering layer 15 is not limited to that shown, and may be provided at any position on the main surface or inside of the laminated glass 10. For example, the light scattering layer 15 may be located on the fourth main surface F4. However, in that case, it is preferable that the light scattering layer 15 is not present in the area where the optical member 30 is located, i.e., in the area where the adhesive layer 40 is located.

[0023] The light scattering layer 15 may extend over the entire surface direction (xy plane direction) of the window glass 100, but as shown in Figures 2 and 3, it may be formed discontinuously scattered across the entire window glass 100 in the surface direction. For example, the light scattering layer 15 may be formed in advance by printing on one or both surfaces of the interlayer 13 in a predetermined discontinuous pattern before the laminated glass 10 is manufactured. Alternatively, the light scattering layer 15 may be formed by printing on the fourth main surface F4. It can also be formed by roughening the surface of the glass plate 11 by lithography or chemical etching of the glass plate 12, or by printing a scattering material containing inorganic or organic fine particles onto the surface of the glass plate. As the light scattering layer 15, a layer with irregularities that enable light scattering formed on the main surface of a layer extending over the entire surface direction may be inserted into the laminated glass 10. The scattering layer can be set in various positions, but since the light guide in this configuration is the glass plate 12, it is desirable to set the scattering layer at a position in contact with the glass plate 12.

[0024] As shown in Figure 1, the laminated glass 10 may be provided with a shielding layer 18 to protect the sealant, etc., that adheres and holds the window glass 100 to the vehicle body. The shielding layer 18 will not be shown in the cross-sectional views from Figure 2 onward. The shielding layer 18 can be formed, for example, by applying a low-luminosity ceramic color paste, such as black, gray, or brownish-red, containing a fusible glass frit containing a black pigment, and firing it. The shielding layer 18 may be formed on one or more peripheries of the second main surface F2, third main surface F3, and fourth main surface F4 of the laminated glass 10, preferably on at least one periphery of the second main surface F2 and the fourth main surface F4, for example, on the periphery of the second main surface F2. By forming the shielding layer 18 on the second main surface F2, it is possible to prevent light from leaking out of the vehicle from the optical member 30. The shielding layer 18 may be provided in the peripheral region of the laminated glass 10, extending from the peripheral edge (from the end face) for a period of 10 mm to 500 mm. Furthermore, when a single laminated glass is installed across multiple openings in the vehicle body, the shielding layer 18 may also be provided in a strip-like shape extending in the x-direction, for example, as shown in Figure 1, in a portion of the main region, which is the area inside the peripheral region of the laminated glass 10, corresponding to the portion where the vehicle body frame extends. When the shielding layer 18 is set on the same plane as the optical member 30, it is provided avoiding the area where the optical member 30 is located, i.e., the area where the adhesive layer 40 is located.

[0025] The light source 20 used in this embodiment has, for example, an LED (Light Emitting Diode). The LED is, for example, a white LED. The white LED may be (A) a combination of a blue LED and a yellow phosphor, or (B) a combination of a blue LED, a green LED, and a red LED. When the light source 20 is a white LED, the correlated color temperature of the white LED is preferably 3000K to 5000K. The correlated color temperature of the light source 20 is measured in accordance with JIS Z8725:2015.

[0026] As described above, the light source 20 may have only one LED that emits light of a specific color, or it may have multiple LEDs that emit light of different colors. The multiple LEDs may be mounted on a PCB substrate or a flexible substrate, for example, and arranged at intervals along the periphery of the light guide layer 21. In that case, the light source 20 may be, for example, a long member (LED light bar) in which multiple LEDs are arranged in a straight line and the entire structure is sealed with resin. The resin used for sealing may include acrylic resin (PMMA), polycarbonate resin (PC), etc. By using multiple full-color LEDs, the position and color of illumination can be arbitrarily adjusted, increasing the freedom of design. Note that the LEDs may include OLEDs (Organic Light Emitting Diodes). In addition, the light source 20 may have a semiconductor laser (LD: Laser Diode) instead of LEDs.

[0027] The light source 20 may be located near the peripheral edge of the window glass 100, more specifically, along the edge of the plan view shape of the window glass 100. In the example shown in Figure 1, the light sources 20 are provided in the regions at both ends in the x-direction. In the example shown in Figure 1, two light sources 20 are provided at each end in the x-direction for one window glass 100, separated in the y-direction. However, the arrangement and number of light sources 20 can be appropriately determined according to the size of the window glass 100, the desired function, purpose, etc.

[0028] The optical member 30 is a member for guiding light from the light source 20 into the laminated glass 10, and is also called a prism. As shown in Figures 2 and 3, the optical member 30 is bonded to the main surface of the laminated glass 10, more specifically to the fourth main surface F4 of the laminated glass 10, via an adhesive layer 40. The presence of the optical member 30 allows the direction of light emitted from the light source 20 to be changed, enabling it to be properly guided into the laminated glass 10. The optical member 30 in this embodiment may be a member that transmits at least visible light. The refractive index of the optical member 30 is preferably 1.45 to 1.58, more preferably 1.48 to 1.55, and even more preferably 1.50 to 1.53 for light with a wavelength of 525 nm. The above refractive index is the refractive index at the central part 32 (described later) of the optical member 30.

[0029] Furthermore, it is preferable to use an optical element 30 having the following light transmittances when calculated per 1 mm thickness: The transmittance TvB for light with a wavelength of 467 nm is preferably 0.85 or higher, more preferably 0.90 or higher. The transmittance TvG for light with a wavelength of 532 nm is preferably 0.80, more preferably 0.85. The transmittance TvR for light with a wavelength of 630 nm is preferably 0.85, more preferably 0.90. The above light transmittances are the transmittances at the central part 32 (described later) of the optical element 30.

[0030] The optical component 30 may be made of resin, that is, a component made of a material mainly containing resin. Alternatively, the optical component 30 may be a resin molded body formed by extrusion molding, injection molding, etc. Examples of resins constituting the optical component 30 include acrylic resin (PMMA), polycarbonate resin (PC), polyamide resin (PA), cyclic olefin copolymer (COC), polystyrene (PS), and / or cycloolefin polymer (COP).

[0031] The optical element 30 is elongated. As shown in Figures 1 to 3, the optical element 30 is positioned on the window glass 100 such that its longitudinal direction aligns with the y-direction of the window glass 100. The aforementioned elongated light source 20 is positioned on the side of the optical element 30 closest to the peripheral edge of the window glass 100, such that the longitudinal direction of the light source 20 aligns with the longitudinal direction of the optical element 30. As shown in Figure 2, the light source 20 may be provided on the end face of the optical element 30 on the peripheral edge side of the window glass 100 by another support member (not shown). Alternatively, the light source 20 may be bonded to the optical element 30 using an adhesive or other bonding means, or it may be integrally molded together with the optical element 30.

[0032] Both the light source 20 and the optical element 30 are positioned on the fourth main surface F4 of the laminated glass 10. While it is possible to introduce light into the glass plate 12 by setting the light source on the edge of the glass plate 12, this presents challenges regarding the vehicle's watertightness and space. On the other hand, by providing the light source on the fourth main surface F4 of the glass plate 12 as in this configuration, the optical element can be laid out at any position within the glass surface, eliminating the need for a watertight structure.

[0033] As shown in Figure 2, the optical member 30 has a rectangular cross-section when cut by a plane perpendicular to the longitudinal direction, that is, it has the shape of a rectangular prism overall, but the shape of the optical member 30 is not limited to that shown. The shape of the optical member 30 is limited to the surface facing the fourth main surface F4 of the laminated glass 10 being a plane. For example, the shape of the cross-section of the optical member 30 when cut by a plane perpendicular to the longitudinal direction may be a polygon other than a quadrilateral, such as a triangle or pentagon, or it may be a partial circle or partial ellipse.

[0034] In this specification, "long" refers to a member whose length in one direction is sufficiently longer than its length in the direction perpendicular to that direction. Furthermore, a long member can be a rod-shaped, linear, strip-shaped, or any other shape. In this embodiment, the optical member 30 has a length in the y-direction in the drawing that is sufficiently longer than its length in the x-direction or z-direction. For example, the longitudinal length (y-direction length in the drawing) L of the optical member 30 may be 5 to 50 times its transverse length (x-direction length in the drawing).

[0035] The longitudinal length (y-direction length, also called the total length) L of one optical element 30 is determined according to the size, shape, etc. of the window glass 100, but is preferably 50 mm or more and 1000 mm or less, and more preferably 100 mm or more and 400 mm or less.

[0036] Furthermore, the length of one optical member 30 in the short direction (length in the x direction) is measured on the outer surface of the optical member 30, that is, the surface in contact with the adhesive layer 40 (hereinafter also referred to as the adhesive surface of the optical member 30), and is preferably 5 mm to 50 mm, more preferably 15 mm to 30 mm.

[0037] Furthermore, the thickness of the optical element 30 (length in the z-direction in the drawing) may preferably be 1 mm or more and 5 mm or less. If the thickness of the optical element 30 is not uniform in the longitudinal direction (as described later), the above thickness shall be the thickness of the central part 32.

[0038] The thickness of the adhesive layer 40 on the window glass 100 (length in the z direction in the drawing) is preferably 50 μm or more and 1,000 μm or less, more preferably 100 μm or more and 500 μm or less, and even more preferably 150 μm or more and 300 μm or less. The thickness of the adhesive layer 40 is the thickness at the central part 32 (described later) of the optical member 30.

[0039] The adhesive layer 40 is not particularly limited as long as it can bond the surface of the glass plate to the optical member 30 described above and does not hinder the introduction of light from the optical member 30 into the glass interior 10. Preferably, the adhesive layer 40 is a transparent adhesive layer that transmits at least visible light. The refractive index of the adhesive layer 40 in the window glass 100 for light with a wavelength of 525 nm may be the same as the refractive index of the optical member 30 for light with the above wavelength. That is, the refractive index of the adhesive layer 40 in the window glass 100 for light with a wavelength of 525 nm may be preferably 1.45 or more and 1.58 or less, more preferably 1.48 or more and 1.55 or less, and even more preferably 1.50 or more and 1.53. Furthermore, both the refractive index of the adhesive layer 40 and the refractive index of the optical member 30 may be preferably 1.45 or more and 1.58 or less, more preferably 1.48 or more and 1.55 or less, and even more preferably 1.50 or more and 1.53. Furthermore, the refractive index of the adhesive layer 40 and the refractive index of the optical component 30 may be different, but it is preferable that they be the same.

[0040] Furthermore, it is preferable to use an adhesive for the adhesive layer 40 that has the following light transmittances when the thickness of the adhesive layer 40 is calculated at 100 μm: The transmittance TvB for light with a wavelength of 467 nm is preferably 0.85 or higher, more preferably 0.90 or higher. The transmittance TvG for light with a wavelength of 532 nm is preferably 0.80, more preferably 0.85. The transmittance TvR for light with a wavelength of 630 nm is preferably 0.85, more preferably 0.90.

[0041] The adhesive constituting the adhesive layer 40 may be a curing type adhesive that hardens with heat, light, etc., and a photocuring type adhesive that hardens with light such as ultraviolet light is preferred. The adhesive layer 40 may be a layer formed by applying a liquid adhesive, for example, a liquid optical transparent adhesive (LOCA). Specific types of adhesives include one or more resin adhesives such as acrylate-based, silicone-based, urethane-based, urethane acrylate-based, epoxy-based, epoxy acrylate-based, acrylamide-based, and methacryamide-based adhesives. The adhesive layer 40 may also be formed by adhering a transparent resin adhesive sheet instead of using a liquid adhesive.

[0042] In the window glass 100 according to this embodiment having the configuration described above, light introduced from the light source 20 to the optical member 30 is introduced into the laminated glass 10 through the adhesive layer 40, scattered by the light scattering layer 15 in the laminated glass 10, and emitted from the main surface of the laminated glass 10, preferably the surface on the inside of the vehicle. As a result, the window glass 100 can have an illumination function that emits a predetermined light, or a display function that displays a predetermined image. When the window glass 100 is for an automobile, depending on the configuration of the light source 20 and the light scattering layer 15, it can function as an illumination device that illuminates the inside of the automobile, for example, as an electric illumination device, or as a display device that can be seen by the occupants of the automobile.

[0043] <Bonding of optical components> As explained with reference to Figures 1 to 3, in the window glass 100 according to this embodiment, a long optical member 30 is bonded to the main surface of the laminated glass 10 via an adhesive layer 40. In actual use, the window glass 100 is often exposed to environments with large temperature fluctuations, and in such environments, the optical member 30 is prone to thermal volume changes, specifically thermal expansion and / or contraction. However, the adhesive layer 40 may not be able to adequately follow the volume changes of the optical member 30, and delamination may occur between the optical member 30 and the adhesive layer 40, or between the adhesive layer 40 and the glass plate, or fracture may occur within the adhesive layer 40. In any case, delamination occurs between the optical member 30 and the laminated glass 10. When such delamination occurs, light incident on the optical member 30 from the light source 20 is not introduced into the laminated glass 10 via the adhesive layer 40, and the illumination and display functions of the window glass 100 cannot be adequately obtained. In particular, when the optical member 30 is long, the effects of volume changes tend to appear at the ends in the longitudinal direction, so the above-mentioned delamination phenomenon is likely to occur at the end 31 (Figure 3) of the optical member 30.

[0044] In contrast, in one embodiment of the present disclosure, the adhesive strength between the optical member 30 and the laminated glass 10 is not made uniform throughout, but differs at the end 31 in the longitudinal direction (y-direction in the drawing) of the long optical member 30. More specifically, in this embodiment, the adhesive strength between the end 31 of the optical member 30 and the fourth main surface F4 is greater than the adhesive strength between the central part 32 and the fourth main surface F4. Here, the above adhesive strength is at least the shear adhesive strength. Therefore, this embodiment is a window glass 100 having at least the configuration in which the shear adhesive strength S1 between the end 31 of the optical member 30 and the fourth main surface F4 is greater than the shear adhesive strength S0 between the central part 32 and the fourth main surface (i.e., S1 > S0).

[0045] In this specification, the longitudinal end portion 31 of the optical member 30 may be the portion from the end face (edge) of the optical member 30 to a position that is 1 / 25 or less of the longitudinal length L of the optical member 30 (L / 25 or less). That is, the length of the end portion 31 shown in Figure 3 may be Le = L / 25. The region of the optical member 30 other than both ends 31, 31, i.e., the region in the longitudinal direction centered above both ends 31, 31, is defined as the central portion 32. Furthermore, the end portion 31 may be the portion from the end face of the optical member to a position 5 mm or less in the longitudinal direction. That is, the length of the end portion 31 shown in Figure 3 may be Le ≤ 5 mm.

[0046] In this way, by making the shear bonding strength S1 between the end portion 31 and the fourth main surface F4 greater than the shear bonding strength S0 between the central portion 32 and the fourth main surface F4, even if the volume change (expansion and / or contraction) of the end portion 31 becomes large when affected by heat, the end portion 31 can be held in place so as not to peel off from the surface of the laminated glass 10, thereby suppressing or preventing the aforementioned delamination phenomenon between the optical member 30 and the laminated glass.

[0047] Furthermore, through diligent research by the inventors, they discovered a location where stress is likely to occur when glass and other materials with different coefficients of thermal expansion are bonded together via an adhesive layer and placed in an environment with temperature fluctuations. According to the above, the location where stress is likely to occur depends on the material, shape, and thickness of the optical material, but it was found to be near a position of L / 500 to L / 25 in the longitudinal direction from the edge of the optical material 30. Therefore, by making the portion of the optical material 30 whose structure is changed the portion up to L / 25 or less from the longitudinal edge of the optical material 30, the volume change in the portion of the optical material 30 that is prone to delamination is reduced, and delamination between the optical material 30 and the glass can be effectively prevented. In addition, since the length of the central portion 32 can be ensured to be longer, the desired function of the optical material 30 is also maintained.

[0048] The relationship between the shear bonding strength S1 at the end portion 31 and the shear bonding strength S0 at the central portion 32 (S1 > S0) only needs to be satisfied at at least one end portion 31 of the optical member 30, but it is preferable that it be satisfied at both ends 31, 31, as this can more reliably suppress the delamination phenomenon.

[0049] Figure 4 shows an enlarged view of part III of Figure 3. In the example shown in Figure 4, the adhesive layer 40 interposed between the optical member 30 and the laminated glass 10 to bond them together is different in the region of the end portion 31 and the region of the central portion 32. More specifically, the adhesive layer 40 includes a first adhesive layer 41 that bonds the end portion 31 to the laminated glass 10 and a second adhesive layer 42 that bonds the central portion 32 to the laminated glass 10. The adhesive constituting the first adhesive layer 41 has a greater adhesive strength than the adhesive constituting the second adhesive layer 42. By forming the adhesive layer 40 using two types of adhesives with different adhesive strengths, the above relationship (S1>S0), where the shear adhesive strength S1 at the end portion 31 is greater than the shear adhesive strength S0 at the central portion 32, can be obtained more reliably. This is because, when different adhesives are used, if the type of adhesive is known, the relationship between the magnitude of the adhesive strengths of the adhesive constituting the first adhesive layer 41 and the adhesive constituting the second adhesive layer 42 can be predicted or recognized from preliminary tests, etc. In other words, the adhesives constituting the first adhesive layer 41 and the adhesives constituting the second adhesive layer 42 should be selected such that the above relationship (S1 > S0) regarding the shear bonding strength at the end portion 31 and the central portion 32 is obtained.

[0050] When different adhesives are used for the first adhesive layer 41 and the second adhesive layer 42, for example, the adhesive constituting the first adhesive layer 41 can be a thermosetting adhesive, and the adhesive constituting the second adhesive layer 42 can be a UV-curing adhesive.

[0051] The shear bonding strength S0 between the central portion 32 of the optical member 30 and the fourth main surface F4 is preferably 0.1 MPa or more, more preferably 0.2 MPa or more, and even more preferably 0.3 MPa or more. Furthermore, the shear bonding strength S1 between the end portion 31 of the optical member 30 and the fourth main surface F4 is preferably 0.3 MPa or more, more preferably 0.5 MPa or more, and even more preferably 1 MPa or more. Having the shear bonding strength S1 within the above range improves the effect of suppressing the peeling phenomenon at the end portion 31 of the optical member 30.

[0052] The shear bonding strength S1 at the end portion 31 and the shear bonding strength S0 at the central portion 32 can be measured by cutting out the end portion 31 and the central portion 32 of the optical member 30 from the window glass 100, and performing a shear test on each portion, for example, in accordance with JIS 6850:1999.

[0053] Furthermore, in this embodiment, if the shear bonding strength S1 between the end portion 31 and the laminated glass 10 is greater than the shear bonding strength S0 between the central portion 32 and the laminated glass 10, it is not necessarily required to use two or more types of adhesives. In that case, the bonding surface of the end portion 31 and at least one of the region of the fourth main surface F4 of the laminated glass 10 facing the end portion 31 may be configured to improve the adhesive strength to the adhesive layer. To this end, at least one of the bonding surface of the end portion 31 and the region of the fourth main surface F4 of the laminated glass 10 facing the end portion 31 can be subjected to a surface treatment to improve the adhesive strength. When surface treatment is used, it is preferable in that it does not require preparing multiple types of adhesives, thus keeping the manufacturing process simple.

[0054] Figure 5 shows an example of a configuration in which the adhesive strength to the adhesive layer is improved for at least one of the bonding surfaces of the end portion 31 and the region of the fourth main surface F4 of the laminated glass 10 that faces the end portion 31. In the example shown in Figure 5(a), a resin primer p3 is applied to the bonding surface of the end portion 31. As a result, the adhesive strength of the bonding surface of the end portion 31 to the adhesive layer 40 is greater than the adhesive strength of the bonding surface of the central portion 32 to the adhesive layer 40.

[0055] In the example shown in Figure 5(b), a glass primer p1 is applied to the region of the fourth main surface F4 of the laminated glass 10 that faces the end portion 31. As a result, the adhesive strength of the region of the fourth main surface F4 facing the end portion 31 to the adhesive layer 40 is greater than the adhesive strength of the region facing the central portion 32 to the adhesive layer 40.

[0056] Alternatively, instead of applying a primer as described above, the adhesive strength of the adhesive layer 40 can be increased by performing a treatment to adjust at least one of the surface roughness of the adhesive surface of the end portion 31 of the optical member 30 and the surface roughness of the region of the fourth main surface F4 of the laminated glass 10 that faces the end portion 31.

[0057] Furthermore, the bonding surface of the end portion 31 may be treated with a primer or the like, and the area of ​​the fourth main surface F4 of the laminated glass 10 facing the end portion 31 may also be treated with a primer p1 or the like. In that case, the shear bonding strength between the end portion 31 and the fourth main surface F4 can be further improved. Also, even if the above-mentioned surface treatment is applied, a first adhesive layer 41 with stronger adhesive strength can be used as the adhesive layer 40 to bond the end portion 31.

[0058] Furthermore, the refractive index of light with a wavelength of 535 nm at the end portion 31 may be smaller than the refractive index of light with a wavelength of 535 nm at the central portion 32. However, in order to minimize the difference in light-guiding function between the end portion 31 and the central portion 32, it is preferable that the difference between the refractive index at the end portion 31 and the refractive index at the central portion 32 with respect to light with a wavelength of 535 nm be 0.02 or less.

[0059] The difference in the coefficient of linear expansion between the optical element 30 and the interior glass plate 12 is preferably 4.0*10 at room temperature. -4 / K or less, more preferably 1.0*10 -4 It may be less than or equal to / K. In this specification, "room temperature" is defined as 298K. The coefficient of linear expansion can be measured by thermomechanical analysis. By using a material with the above-described difference in the coefficient of linear expansion as the optical component 30, the delamination phenomenon between the optical component 30 and the laminated glass 10 can be further suppressed.

[0060] The coefficient of linear expansion of the optical element 30 is 1.0 * 10 -5 / K or more 3.0*10 -4 It may be less than or equal to / K. Also, the coefficient of linear expansion of the interior glass plate 12 is 5*10 -6 / K or more 1.0*10-5 It may be less than or equal to / K.

[0061] <Modified examples of optical components> Figure 6 shows modified shapes of the end portion 31 of the optical component 30. In all the examples shown in Figure 6, similar to the examples shown in Figure 4, the adhesive layer 40 includes a first adhesive layer 41 that adheres to the end portion 31 and a second adhesive layer 42 that adheres to the central portion 32, and the adhesive strength of the first adhesive layer 41 is greater than that of the second adhesive layer 42. Furthermore, the thickness (length in the z direction) of the end portion 31 is smaller than the thickness of the central portion 32. By making the thickness of the end portion 31 smaller than the thickness of the central portion 32, the volume of the end portion 31 is reduced, and volume changes when affected by heat are also suppressed, thus contributing to the suppression of the peeling phenomenon described above.

[0062] In the example shown in Figure 6(a), the exterior surface (adhesive surface) of the optical member 30 is flush from the central portion 32 to the end portion 31, but a step is formed on the interior surface of the optical member 30 at the boundary between the central portion 32 and the end portion 31. On the other hand, in the example shown in Figure 6(b), the interior surface of the optical member 30 is flush, but a step is formed on the exterior surface (adhesive surface) of the optical member 30 between the central portion 32 and the end portion 31. The example shown in Figure 6(a) is preferable because it avoids the hassle of applying adhesive to the step. The example shown in Figure 6(b) is preferable because it reduces inconveniences such as the interior surface of the optical member 30 catching on another member during or after installation, and it makes it easier to recognize the application area of ​​the adhesive when two types of adhesive are used to form the first adhesive layer 41 and the second adhesive layer 42.

[0063] As shown in Figure 6(c), the thickness of the end portion 31 gradually decreases toward the outer edge in the longitudinal direction (the +y direction in the drawing). The example shown in Figure 6(c) is preferable because it prevents the hassle of applying adhesive to the step and reduces inconveniences such as the step at the end portion 31 catching on another component during or after the optical component 30 is installed.

[0064] <Method of manufacturing window glass> One embodiment of this disclosure may be the window glass manufacturing method described above. For example, a window glass manufacturing method according to one embodiment may be a method for manufacturing window glass in which a laminated glass is prepared having an outer glass plate having a first main surface and a second main surface, an inner glass plate having a third main surface and a fourth main surface, and an interlayer disposed between the second main surface and the third main surface, and a long optical member that guides light from a light source to the laminated glass is attached to the optical member by bonding a long optical member to the fourth main surface via an adhesive layer, a light scattering layer that scatters the light is provided inside the laminated glass or on the fourth main surface, the shear adhesive strength between the longitudinal end of the optical member and the fourth main surface is S1, and the shear adhesive strength between the central part in the longitudinal direction, which is further from the end, and the fourth main surface is S0, and S1 > S0 is satisfied.

[0065] Although the present disclosure has been described above based on embodiments, the present disclosure is not limited to these embodiments. Furthermore, the above embodiments can be modified, altered, replaced, added, deleted, and combined in various ways within the scope of the claims, and these also fall within the technical scope of the present disclosure. [Explanation of symbols]

[0066] 10 Laminated glass 11. Exterior glass panel 12. Inner window pane 13 Interlayer 15 Light scattering layer 18 Shielding layer 20 light source 30 Optical components 31 End of optical component 32 Central part of the optical component 40 Adhesive layer 41. First adhesive layer 42 Second adhesive layer 100 window glass

Claims

1. An exterior glass panel having a first main surface and a second main surface, An interior glass panel having a third main surface and a fourth main surface, Laminated glass having an interlayer disposed between the second main surface and the third main surface, Light source and A long optical member, bonded to the fourth main surface via an adhesive layer, guides light from the light source to the laminated glass, The laminated glass or the fourth main surface is provided with a light scattering element that scatters the light, A window glass in which the shear bonding strength between the longitudinal end of the optical member and the fourth main surface is S1, and the shear bonding strength between the central part of the optical member located in the longitudinal center of the end and the fourth main surface is S0, such that S1 > S0.

2. The window glass according to claim 1, wherein the end portion is a portion extending from the end face of the optical member to a position L / 25 or less in the longitudinal direction, where L is the length of the optical member in the longitudinal direction.

3. The window glass according to claim 1 or 2, wherein the end portion extends from the end face of the optical member to a position of 50 mm or less in the longitudinal direction.

4. The window glass according to claim 1 or 2, wherein the optical member is made of resin.

5. The difference in coefficient of linear expansion between the optical element and the interior glass plate is 4.0 * 10 at room temperature. －４ The window glass according to claim 1 or 2, wherein the temperature is less than or equal to / K.

6. The window glass according to claim 1 or 2, wherein the adhesive layer is made of a transparent adhesive.

7. The window glass according to claim 1 or 2, wherein the ends are both ends in the longitudinal direction of the optical member.

8. The window glass according to claim 1 or 2, wherein S1 is 0.3 MPa or more, and S0 is 0.1 MPa or more.

9. The window glass according to claim 1 or 2, wherein the adhesive layer includes a first adhesive layer for bonding the end portion and a second adhesive layer for bonding the central portion, and the adhesive strength of the first adhesive layer is greater than the adhesive strength of the second adhesive layer.

10. The window glass according to claim 1 or 2, wherein the adhesive strength of the end surface to the adhesive layer is greater than the adhesive strength of the central surface to the adhesive layer.

11. The window glass according to claim 10, wherein a primer is applied to the adhesive surface of the end portion.

12. The window glass according to claim 1 or 2, wherein the adhesive strength to the adhesive layer in the region of the fourth main surface facing the end is greater than the adhesive strength to the adhesive layer in the region facing the central part.

13. The window glass according to claim 12, wherein a primer is applied to the end of the fourth main surface.

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