Light control laminated glass

Abstract

A light control laminated glass (10) comprises: a light control layer (14) that is capable of adjusting the transmittance of light when a voltage is applied thereto; a pair of conductive layers (15, 15) that are disposed so as to sandwich the light control layer (14) therebetween and that apply a voltage to the light control layer (14) when power is supplied thereto; intermediate layers (13) that are disposed so as to sandwich the conductive layers (15, 15) therebetween and that have insulation properties; and a pair of glass plates (11, 12) that are disposed so as to sandwich the intermediate layers (13) therebetween and that each have a first region (A) and a second region (B) which have mutually different curvatures, wherein the second region (B) includes curved regions (40) that have a smaller radius of curvature than that of the first region (A), and a short-circuit prevention part (50) for preventing a short circuit caused by contact between the pair of conductive layers (15, 15) is formed between the pair of curved regions (40, 40).

Description

Light-adjustable laminated glass

[0001] The present invention relates to light-controlling laminated glass.

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

[0003] International Publication No. 2022 / 153998

[0004] Light control laminated glass used in window glass for vehicles and the like uses a thin light control part. Furthermore, light control laminated glass may have a curved region in part to match the shape of the vehicle or the like. Therefore, if the light control part (a light control layer and a pair of conductive layers) is disposed between a pair of curved regions, wrinkles may occur in the light control part, and these wrinkles may cause the pair of conductive layers to come into contact and short-circuit. If the pair of conductive layers in the light control part are short-circuited, proper current cannot be passed from the pair of conductive layers to the light control layer, making light control impossible not only in the short-circuited portion of the pair of conductive layers but also throughout the entire light control layer.

[0005] Therefore, there is a demand for a light control laminated glass that can prevent short circuits caused by contact between a pair of conductive layers included in the light control part.

[0006] The characteristic configuration of the light control laminated glass of the present invention is that it comprises a light control layer that can adjust the light transmittance by applying a voltage, a pair of conductive layers that are arranged to sandwich the light control layer and that apply the voltage to the light control layer by supplying power, an insulating intermediate layer that is arranged to sandwich the conductive layer, and a pair of glass plates that are arranged to sandwich the intermediate layer and each have a first region and a second region with different curvatures, wherein the second region includes a curved region that has a smaller radius of curvature than the first region, and a short circuit prevention portion is formed between the pair of curved regions to prevent a short circuit due to contact between the pair of conductive layers.

[0007] In a light-control laminated glass, when a pair of glass plates are formed to have a pair of curved regions and a light-control layer and a pair of conductive layers are disposed between the pair of curved regions, the pair of conductive layers may come into contact and short-circuit. Therefore, the light-control laminated glass of the present configuration includes a pair of glass plates each having a first region and a second region with different curvatures, the second region including a curved region with a smaller radius of curvature than the first region, and a short-circuit prevention part is formed between the pair of curved regions to prevent a short circuit caused by contact between the pair of conductive layers disposed with the light-control layer sandwiched therebetween. Therefore, the presence of the short-circuit prevention part in the light-control laminated glass prevents a short circuit between the pair of conductive layers disposed between the pair of curved regions. This allows the light-control laminated glass to stably continue light control even in a shape including curved regions. As a result, the light-control laminated glass can maintain its light-control function well.

[0008] Another characteristic feature is that the short-circuit prevention section does not include the light-controlling layer and the pair of conductive layers, but is composed only of the intermediate layer and the pair of glass plates.

[0009] In this configuration, the short-circuit prevention section does not include a photochromic layer or a pair of conductive layers, but is composed only of an intermediate layer and a pair of glass plates. This prevents short circuits caused by the pair of conductive layers from occurring in the short-circuit prevention section. This allows the light-control laminated glass to continue light control stably in areas other than the short-circuit prevention section. As a result, the light-control laminated glass can properly maintain its light-control function.

[0010] Another characteristic feature is that the short-circuit prevention portion does not have the pair of conductive layers, and is composed only of the light control layer, the intermediate layer, and the pair of glass plates.

[0011] In this configuration, when the short-circuit prevention section does not have a pair of conductive layers and is composed only of a light-control layer, an intermediate layer, and a pair of glass plates, a short circuit caused by the pair of conductive layers does not occur in the short-circuit prevention section. This allows the light-control laminated glass to continuously control light in areas other than the short-circuit prevention section. As a result, the light-control laminated glass can properly maintain its light-control function.

[0012] Another characteristic feature is that the short-circuit prevention portion separates the dimming layer and the pair of conductive layers arranged between the pair of first regions from the dimming layer and the pair of conductive layers arranged between the pair of second regions so that the boundary between the first region and the second region is electrically non-conductive in a planar view.

[0013] According to this configuration, the short-circuit prevention part separates, in a plan view, the photochromic layer and the pair of conductive layers arranged between the pair of first regions from the photochromic layer and the pair of conductive layers arranged between the pair of second regions. Therefore, the photochromic layer and the pair of conductive layers in the pair of first regions and the photochromic layer and the pair of conductive layers arranged between the pair of second regions each independently exhibit photochromic functions. This allows the photochromic laminated glass to continue to independently control light using the photochromic layer arranged between the pair of first regions, even if a short circuit occurs between the pair of conductive layers in the pair of second regions, including the curved region, making photochromic control by the photochromic layer impossible. As a result, the photochromic laminated glass can properly maintain its photochromic function.

[0014] Another characteristic feature of the short-circuit prevention portion is that the film thickness of the photochromic layer arranged between a pair of the second regions is greater than the film thickness of the photochromic layer arranged between a pair of the first regions.

[0015] According to this configuration, in the pair of second regions, the presence of a photochromic layer having a thickness greater than that of the photochromic layer between the pair of first regions ensures a large distance between the pair of conductive layers. Therefore, even if wrinkles occur in the photochromic layer and the pair of conductive layers in the second region including the curved region, the pair of conductive layers are maintained spaced apart, preventing short circuits due to contact between the pair of conductive layers. This allows the photochromic laminated glass to stably continue light control by the photochromic layer even in the curved region having the short-circuit prevention portion. As a result, the photochromic laminated glass can ensure appropriate light control function.

[0016] Another characteristic feature of the short-circuit prevention portion is that an insulating member is interposed between the dimming layer and the pair of conductive layers arranged between the pair of first regions and the dimming layer and the pair of conductive layers arranged between the pair of second regions, so that the boundary between the first region and the second region is electrically non-conductive in a planar view.

[0017] According to this configuration, an insulating member is interposed between the photochromic layer and the pair of conductive layers arranged between the pair of first regions and the photochromic layer and the pair of conductive layers arranged between the pair of second regions. Therefore, the photochromic layer and the pair of conductive layers arranged between the pair of first regions and the photochromic layer and the pair of conductive layers arranged between the pair of second regions each independently exhibit photochromic functions. This allows the photochromic layer arranged between the pair of first regions to continue to independently control light even if the photochromic layer arranged between the pair of second regions becomes unable to control light due to a short circuit or other influence from the pair of conductive layers. As a result, the photochromic laminated glass can properly maintain its photochromic function.

[0018] Another characteristic feature is that the voltage applied to the light-controlling layer is 30 V or more when the haze value is set to 10% or less.

[0019] In this configuration, when a voltage of 30 V or more is applied to the dimming layer to reduce the haze value to 10% or less, the transparency of the dimming layer can be effectively increased, and the short circuit caused by high voltage is prevented by the short circuit prevention section, allowing the dimming function to be properly exerted.

[0020] Another characteristic feature is that the thickness of the light-controlling layer is 5 μm or more and 150 μm or less.

[0021] According to this configuration, the thickness of the light control layer is 5 μm or more and 150 μm or less, so the light control laminated glass can ensure the appropriate light control function of the light control layer while reducing the weight of the light control layer. Furthermore, even with such a thin light control layer, the short-circuit prevention part prevents contact between the pair of conductive layers, thereby preventing short circuits.

[0022] Another characteristic feature is that the glass plate has a three-dimensional curvature in the second region.

[0023] In this configuration, the glass sheet in the second region has a three-dimensional curvature, so the shape of the light control laminated glass can be appropriately changed to suit the installation location. Furthermore, even in glass sheets with complex shapes having three-dimensional curvature, the short-circuit prevention part prevents contact between the pair of conductive layers, thereby preventing short circuits.

[0024] Another characteristic feature is that the intermediate layer includes a support layer that supports the conductive layer, and an adhesive layer that has a Young's modulus smaller than that of the support layer.

[0025] The interlayer used in laminated glass is often made of a material with a high Young's modulus to ensure the strength of the laminated glass. However, if an interlayer with a high Young's modulus is placed on both sides of a pair of conductive layers, when the light-controlling laminated glass vibrates, the vibrations transmitted from the interlayer to the pair of conductive layers may adversely affect the light-controlling layer. Therefore, in the present configuration, the interlayer includes a support layer that supports the conductive layer and an adhesive layer with a lower Young's modulus than the support layer. With this configuration, the light-controlling layer and the pair of conductive layers are supported by the support layer, and when the light-controlling laminated glass vibrates, the vibrations transmitted from the adhesive layer to the support layer can be reduced. This allows the light-controlling laminated glass to adequately protect the light-controlling layer and the pair of conductive layers with the support layer and adhesive layer. As a result, the light-controlling laminated glass can adequately prevent the interlayer from deteriorating the function of the light-controlling layer.

[0026] Another feature is that it is located on the roof of the vehicle.

[0027] As in this configuration, by arranging the light-controlling laminated glass on the roof of the vehicle, it is possible to achieve both an open feeling inside the vehicle and privacy by controlling the light of the light-controlling laminated glass arranged on the roof.

[0028] Another characteristic feature is that at least the short circuit prevention portion is provided with a shielding film.

[0029] If the short-circuit prevention section does not have a light-controlling layer or a conductive layer, the short-circuit prevention section cannot control light. Therefore, the presence of the short-circuit prevention section may impair the appearance of the light-control laminated glass. Therefore, in this configuration, a shielding film is provided in the short-circuit prevention section. This ensures that the short-circuit prevention section is shielded from the outside by the shielding film. As a result, the light-control laminated glass can maintain a good appearance.

[0030] Another characteristic feature is that the first area is a substantially flat surface with a radius of curvature of 3000 mm or more, and the second area is a curved surface with a radius of curvature of 2000 mm or less.

[0031] According to this configuration, the first region is flat and the second region is curved, thereby enhancing the design of the vehicle. Furthermore, even in a glass plate having a curved surface with a radius of curvature of the second region of 2000 mm or less, the short-circuit prevention portion prevents contact between the pair of conductive layers, thereby preventing short circuits. Note that the above values ​​are examples of the lower and upper limits of the radius of curvature of the glass plate, and the radius of curvature of the first region is, for example, 3000 mm or more, preferably 4000 mm or more, and more preferably 5000 mm or more. Furthermore, the radius of curvature of the second region is, for example, 2000 mm or less, preferably 1000 mm or less, and more preferably 500 mm or less.

[0032] 1 is a diagram showing a light-adjusting laminated glass to be placed on the roof of a vehicle; FIG. 2 is a partial cross-sectional view of the light-adjusting laminated glass of the first embodiment; FIG. 3 is a partial cross-sectional view of the light-adjusting laminated glass of the second embodiment; FIG. 4 is a plan view of the light-adjusting laminated glass of the third embodiment; FIG. 5 is a partial cross-sectional view of the light-adjusting laminated glass of the third embodiment; FIG. 6 is a partial cross-sectional view of the light-adjusting laminated glass of the fourth embodiment; FIG. 7 is a plan view of the light-adjusting laminated glass of the fifth embodiment; FIG. 8 is a partial cross-sectional view of the light-adjusting laminated glass of the fifth embodiment; FIG. 9 is a comparative example of the light-adjusting laminated glass; FIG. 10 is a diagram showing an example of a curved shape of the light-adjusting laminated glass; FIG. 11 is a diagram showing an example of a curved shape of the light-adjusting laminated glass.

[0033] Hereinafter, embodiments of the light-controlling laminated glass according to the present invention will be described with reference to the drawings. In this embodiment, the light-controlling laminated glass will be described as a glass applied to a vehicle as an example of the light-controlling laminated glass. However, the present invention is not limited to the following embodiment, and various modifications are possible within the scope of the present invention.

[0034] As shown in Figure 1, a light control laminated glass 10 (hereinafter referred to as "laminated glass 10") is used, for example, as roof glass for a vehicle. The laminated glass 10 may also be used for glass other than the roof glass of the vehicle 1, such as rear glass, rear side glass, rear quarter glass, door glass, extra glass, or windshield. The extra glass is glass attached to the rear side of the vehicle 1 to improve rearward visibility for the driver of the vehicle 1.

[0035] 2 , the laminated glass 10 includes a pair of glass plates 11, 12, an intermediate layer 13, a light control layer 14, and a pair of conductive layers 15, 15. The intermediate layer 13 is composed of, for example, a first intermediate layer 31 (an example of an adhesive layer) that bonds to the pair of glass plates 11, 12, and a second intermediate layer 32 (an example of a support layer) that is disposed between the first intermediate layer 31 and the light control layer 14. The light control unit 20 includes the light control layer 14, the pair of conductive layers 15, 15, and the second intermediate layer 32. The light control unit 20 includes an element that can switch the light transmittance of the laminated glass 10.

[0036] The first intermediate layers (adhesive layers) 31, 31 are formed, for example, from a thermoplastic resin. Examples of thermoplastic resins 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. Of these thermoplastic resins, plasticized polyvinyl acetal resins are preferably used for the first intermediate layers (adhesive layers) 31, 31. These thermoplastic resins may be used alone or in combination of two or more. The material forming the first intermediate layers 31, 31 is not limited to thermoplastic resins. The first intermediate layers 31, 31 may contain functional particles such as infrared absorbers, ultraviolet absorbers, and luminescent agents. The first intermediate layers 31, 31 may have a colored portion called a shade band.

[0037] The second intermediate layers (support layers) 32 are transparent resin layers. The thickness of the second intermediate layers 32 is, for example, 5 μm to 500 μm, preferably 10 μm to 200 μm, and more preferably 50 μm to 150 μm. The second intermediate layers 32 are made of, for example, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyether, or the like.

[0038] The light control unit 20 is switchable, for example, between a low transmittance state and a high transmittance state. The transmittance may be switchable in multiple stages or may be switchable continuously (continuously). The light control unit 20 may be disposed over substantially the entire laminated glass 10, or may be disposed over only a portion of the laminated glass 10, as necessary. The planar shape of the light control unit 20 is, for example, a rectangle that is smaller than the planar shape of the laminated glass 10.

[0039] The dimming unit 20 is covered by a first intermediate layer 31. In the dimming unit 20, a second intermediate layer 32 is a support layer that supports the pair of conductive layers 15, 15. The first intermediate layer 31 is an adhesive layer having a smaller Young's modulus than the second intermediate layer 32 (support layer). The first intermediate layer 31 and the second intermediate layer 32 are both formed of resin, and the pair of glass plates 11, 12 are bonded to the dimming unit 20 via the first intermediate layer 31.

[0040] For example, the light-controlling layer 14 has a parallel light transmittance of less than 30% when no voltage is applied and a parallel light transmittance of 30% or more when a voltage is applied. It is more preferable that the light-controlling layer 14 has a parallel light transmittance of 20% or less when no voltage is applied and a parallel light transmittance of 40% or more when a voltage is applied.

[0041] The switchable layer 14 may have a haze of 10% or more when no voltage is applied and less than 10% when a voltage is applied. More preferably, the switchable layer 14 has a haze of 20% or more when no voltage is applied and less than 8% when a voltage is applied. The switchable layer 14 may have a smaller surface area than the intermediate layer 13 (the first intermediate layer 31 and the second intermediate layer 32).

[0042] The light-controlling layer 14 is made of a light-controlling film or the like, and for example, controls the haze ratio of the film depending on whether or not an electric current is applied, thereby creating a transparent state and an opaque state. That is, the light-controlling layer 14 can adjust the light transmittance by applying a voltage. Known types of light-controlling layers 14, such as PDLC (Polymer Dispersed Liquid Crystal) types using liquid crystals, SPD (Suspended Particle Device) types, electrochromic types, and thermochromic types, can be used. The light-controlling film is made of a light-controlling layer 14 made of, for example, a liquid crystal, and a pair of conductive layers 15, 15 arranged on both sides of the light-controlling layer 14.

[0043] The pair of conductive layers 15, 15 are disposed to sandwich the light-controlling layer 14, and a voltage is applied to the light-controlling layer 14 when power is supplied. The intermediate layers 13 (first intermediate layer 31 and second intermediate layer 32) are disposed to sandwich the pair of conductive layers 15, 15 and have insulating properties. The conductive layers 15, 15 may be made of, for example, a transparent conductive oxide (TCO). Examples of TCOs include tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), and indium-doped cadmium oxide. The conductive layers 15, 15 may also be made of transparent conductive polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT), poly(4,4-dioctylcyclopentadithiophene), a laminated film of a metal layer and a dielectric layer, silver nanowires, or a silver or copper metal mesh. The conductive layers 15, 15 are not limited to these and may be formed of other materials.

[0044] The light-controlling layer 14 is opaque when no voltage is applied, and light is controlled and the layer becomes transparent when a voltage is applied via the pair of conductive layers 15. The light-controlling layer 14 may be configured to be transparent when no voltage is applied, and opaque when a voltage is applied.

[0045] The light-controlling layer 14 is configured so that, for example, when the haze value is set to 10% or less, a voltage of 30 V or more is applied. With this configuration, the light-controlling layer 14 in the laminated glass 10 can satisfactorily enhance the transparency and appropriately exhibit the light-controlling function.

[0046] The thickness of the photochromic layer 14 is, for example, 5 μm to 150 μm, preferably 5 μm to 100 μm, and more preferably 5 μm to 50 μm. When the thickness of the photochromic layer 14 is 20 μm to 150 μm, the laminated glass 10 can ensure an appropriate photochromic function in the photochromic layer 14 while reducing the weight of the photochromic layer 14.

[0047] In this embodiment, the laminated glass 10 includes a pair of glass plates 11, 12, with the first glass plate 11 disposed on the vehicle interior side and the second glass plate 12 disposed on the vehicle exterior side. The pair of glass plates 11, 12 face each other, and an intermediate layer 13, a light-controlling layer 14, and a pair of conductive layers 15, 15 are positioned between the pair of glass plates 11, 12. The pair of glass plates 11, 12 are fixed together with the intermediate layer 13, the light-controlling layer 14, and the like sandwiched between them. During this fixing, the pair of glass plates 11, 12 sandwich the intermediate layer 13, the light-controlling layer 14, and the like to form a laminate. The laminate is fixed, for example, in a vacuum controlled to a range of -100 kPa or more and -65 kPa or less, at a temperature of 70°C or more and 110°C or less. These conditions are merely examples, and methods such as heating conditions, temperature conditions, lamination method, and vacuum thickness can be selected as appropriate.

[0048] Known glass plates can be used for the first glass plate 11 and the second glass plate 12, and they can be made of general clear glass. An example of the composition of clear glass is shown below.

[0049] (Clear glass) SiO ２ :70-73% by mass Al ２ O ３ : 0.6 to 2.4 mass% CaO: 7 to 12 mass% MgO: 1.0 to 4.5 mass% R ２ O: 13 to 15 mass% (R is an alkali metal) Fe ２ O ３ Total iron oxide (T-Fe ２ O ３): 0.08 to 0.14% by mass

[0050] In addition to clear glass, green glass containing a predetermined amount or more of iron, privacy glass, and UV-cut green glass can be suitably used for the first glass sheet 11 and the second glass sheet 12. An example of the composition of privacy glass is shown below.

[0051] (Privacy glass) SiO ２ :66-75% by mass Al ２ O ３ :0 to 5% by mass CaO: 5 to 15% by mass MgO: 0 to 6% by mass R ２ O: 10 to 20 mass% (R is an alkali metal) Fe ２ O ３ Total iron oxide (T-Fe ２ O ３ ): 0.5 to 2.5% by mass TiO ２ : 0.2 to 5 mass% Cobalt oxide (CoO) converted to CoO: 50 to 500 mass ppm Se: 0 to 70 mass ppm

[0052] The pair of glass plates 11, 12 are arranged to sandwich the intermediate layer 13, and each has a first region A and a second region B with different curvatures. In the second region B, the glass plates 11, 12 have a three-dimensional curvature. That is, in the second region B, the glass plates 11, 12 are curved not only in the longitudinal direction of the vehicle but also in the transverse direction of the vehicle.

[0053] The second region B includes a curved region 40 having a smaller radius of curvature than the first region A. In the laminated glass 10, for example, the first region A is a substantially flat surface having a radius of curvature of 3000 mm or more, and the second region B is a curved surface having a radius of curvature of 2000 mm or less. Note that the above values ​​are examples of the lower and upper limits of the radius of curvature of the glass plate, and the radius of curvature of the first region A is, for example, 3000 mm or more, preferably 4000 mm or more, and more preferably 5000 mm or more. The radius of curvature of the second region B is, for example, 2000 mm or less, preferably 1000 mm or less, and more preferably 500 mm or less.

[0054] [Comparative Example] For example, when a portion of the flat laminated glass 60A shown in the upper diagram of Fig. 9 is bent to form the laminated glass 60B shown in the lower diagram of Fig. 9, wrinkles may occur in the enclosed area C between the curved regions 40 included in the second region B. In this case, the pair of conductive layers 15, 15 may come into contact with each other and short-circuit, and when the pair of conductive layers 15, 15 are short-circuited, all light control by the light control layer 14 becomes impossible.

[0055] The mechanism by which wrinkles occur in the laminated glass 60B will be described below. When two particularly curved pieces of glass are formed as the pair of glass sheets 11, 12, the radii of curvature of the two pieces of glass differ from each other. For example, this may occur when the radius of curvature of the first glass sheet 11 is smaller than the radius of curvature of the second glass sheet 12. This difference in the radii of curvature of the pair of glass sheets 11, 12 causes misalignment of the pair of conductive layers 15, 15 sandwiched between the pair of glass sheets 11, 12, leaving shear stress after compression bonding, which exacerbates wrinkles in the dimming section 20. Furthermore, when the pair of glass sheets 11, 12 have a three-dimensional curvature, misalignment of the pair of conductive layers 15, 15 is even more likely to occur, further exacerbating wrinkles in the dimming section 20.

[0056] In the process of sandwiching and fixing the intermediate layer 13, the light control layer 14, etc. between the pair of glass plates 11, 12, wrinkles occur in the light control section 20 when the functional film follows the curved shape of the glass plates. These wrinkles are particularly likely to occur on curved surfaces with a small radius of curvature. In other words, the smaller the radius of curvature of the curved surface, the more likely it is that the second intermediate layer 32 (support layer) and the conductive layer 15, which are laminated on the curved surface, will have a mismatch between the upper and lower surfaces of the second intermediate layer 32 and the conductive layer 15 when they follow the curved shape of the glass plates 11, 12.

[0057] Furthermore, in the pair of glass plates 11, 12, the curved surface perimeter varies depending on the location in the portion with a large radius of curvature. When a planar photochromic layer 14 is inserted into the portion of the pair of glass plates 11, 12 with a large radius of curvature and an intermediate layer 13 is laminated on the photochromic layer 14, a slack portion of the intermediate layer 13 containing the photochromic layer 14 appears in the portion with different curved surface perimeters. This slack portion occurs particularly in the portion with a large gap between the perimeters of the pair of glass plates 11, 12 and the perimeter of the intermediate layer 13. The curved glass plates 11, 12 and the intermediate layer 13 with the photochromic layer 14 interposed therebetween are laminated to form a laminate. As described above, this laminate is bonded at high temperatures in a vacuum to form laminated glass. At this high temperature, the intermediate layer 13 expands and contracts, gradually relaxing the slack portion (perimeter gap) and allowing the intermediate layer 13, which was flat on the curved glass surface, to conform to the curved glass surface. However, in areas where the radius of curvature is small in the pair of glass plates 11, 12, or when the pair of glass plates 11, 12 have a three-dimensional curvature as described below, this relaxation may be insufficient, causing wrinkles, which may cause the pair of conductive layers 15, 15 to come into contact with each other, resulting in a short circuit.

[0058] The following two embodiments are exemplified as three-dimensional laminated glass. The laminated glass 61 shown in FIG. 10 is a so-called dish-shaped laminated glass in which two radii of curvature in orthogonal directions are formed on convex portions in the same direction (e.g., convex upwards). The laminated glass 62 shown in FIG. 11 is a so-called saddle-shaped laminated glass in which two radii of curvature in orthogonal directions are formed on convex portions in different directions (convex upwards and convex downwards). In the case of the dish-shaped laminated glass 61, the perimeter of the laminated glass 61 is shorter at the edges. That is, when a flat interlayer 13 is laminated between a pair of glass sheets 11 and 12, excess interlayer 13 is formed at the edges of the laminated glass 61. Therefore, wrinkles in the light control unit 20 are likely to occur at the edges of the laminated glass 61. On the other hand, in the case of the saddle-shaped laminated glass 62, the perimeter of the laminated glass 62 is shorter at the center. That is, when a flat interlayer 13 is laminated between a pair of glass sheets 11 and 12, excess interlayer 13 is formed at the center of the laminated glass 62. Therefore. Wrinkles in the light control section 20 are likely to occur in the center of the laminated glass 62. In the case of the embodiment shown in Figures 10 and 11, the wrinkles may cause the pair of conductive layers 15 to come into contact with each other, increasing the possibility of a short circuit.

[0059] Therefore, in the laminated glass 10 of this embodiment, as shown in Figure 2, a short-circuit prevention section 50 is formed between the pair of curved regions 40, 40. The short-circuit prevention section 50 is provided to prevent a short circuit caused by contact between the pair of conductive layers 15, 15. Therefore, the presence of the short-circuit prevention section 50 in the laminated glass 10 can prevent a short circuit between the pair of conductive layers 15, 15 disposed between the pair of curved regions 40, 40. This allows the laminated glass 10 to continue light control stably even in a shape that includes the curved region 40. As a result, the light control function of the laminated glass 10 can be well maintained.

[0060] In this embodiment, as shown in Fig. 2, the short-circuit prevention unit 50 does not include the light-controlling layer 14 and the pair of conductive layers 15, 15, and is composed only of the second intermediate layer 32 and the pair of glass plates 11, 12. Therefore, a short circuit due to the pair of conductive layers 15, 15 does not occur in the short-circuit prevention unit 50. This allows the laminated glass 10 to continue to control light stably in areas other than the short-circuit prevention unit 50. As a result, the light-control function of the laminated glass 10 can be properly ensured.

[0061] The short-circuit prevention unit 50 is provided with a shielding film 16. The shielding film 16 is an opaque layer, and is provided, for example, in a strip shape along the peripheral edge of the laminated glass 10 including the short-circuit prevention unit 50. The shielding film 16 is, for example, an opaque (e.g., black) colored ceramic layer. The shielding film 16 may be a colored intermediate film or colored film having light-blocking properties, or may be a combination of at least one of them with a colored ceramic layer. The colored film may be integrated with an infrared reflective film or the like.

[0062] The laminated glass 10 has an opaque shielding film 16, which can prevent ultraviolet degradation of resins such as urethane that hold the peripheral edge of the laminated glass 10 to the vehicle body. The shielding film 16 can also conceal the pair of conductive layers 15, 15 electrically connected to the light-control layer 14 and the wiring connected to the electrodes so that they are difficult to see from the outside and / or inside of the vehicle. The shielding film 16 can also reliably shield the short-circuit prevention part 50 from the outside. As a result, the laminated glass 10 can maintain a good appearance.

[0063] The shielding film 16 can be formed, for example, by applying a ceramic color paste containing a fusible glass frit containing a black pigment onto the glass plates (glass plates 11 and 12) by screen printing or the like and then firing the paste, but is not limited to this. The shielding film 16 may also be formed, for example, by applying an organic ink containing a black or dark color pigment onto the glass plates by screen printing or the like and then drying the ink.

[0064] 2 , the shielding film 16 is provided on the vehicle interior side of the first glass sheet 11 and the vehicle interior side of the second glass sheet 12. The shielding film 16 may be provided on only one of the vehicle interior side of the first glass sheet 11 and the vehicle interior side of the second glass sheet 12.

[0065] In this embodiment, as shown in Fig. 1 , a laminated glass 10 is disposed on the roof of a vehicle 1. This allows the vehicle 1 to easily achieve both an open feeling inside the vehicle and privacy by controlling the light emitted by the laminated glass 10 disposed on the roof.

[0066] It is preferable that the first region A of the laminated glass 10 be a substantially flat surface with a radius of curvature of 5000 mm or more, and the second region B be a curved surface with a radius of curvature of 2000 mm or less. In this way, the first region Aa of the laminated glass 10 is flat and the second region B is a curved surface, thereby improving the design of the vehicle.

[0067] Furthermore, in this embodiment, the intermediate layer 13 includes a second intermediate layer 32 as a support layer that supports the conductive layer 15, and a first intermediate layer 31 as an adhesive layer having a smaller Young's modulus than the support layer (second intermediate layer 32). Therefore, the light control layer 14 and the pair of conductive layers 15 are supported by the support layer (second intermediate layer 32), and when the laminated glass 10 vibrates, vibration transmitted from the adhesive layer (first intermediate layer 31) to the support layer (second intermediate layer 32) can be reduced. This allows the laminated glass 10 to adequately protect the light control layer 14 and the pair of conductive layers 15 with the first intermediate layer 31 and the second intermediate layer 32. As a result, the laminated glass 10 can adequately prevent functional deterioration of the light control layer 14 due to the intermediate layer 13. In particular, by configuring the second intermediate layer 32 as the light control section 20, the light control section 20 is easy to handle, and the laminated glass 10 can be easily manufactured by bonding the glass plates 11 and 12 to the light control section 20 via the first intermediate layer 31. Furthermore, even if the first intermediate layer 31 acting as an adhesive layer is deformed, the problem of the light-controlling layer 14 being damaged can be prevented.

[0068] 3 , in the second embodiment, the short-circuit prevention part 50 in the second region B of the laminated glass 10 is composed of a light control layer 14, an intermediate layer 13, and a pair of glass plates 11, 12. That is, in this embodiment, the short-circuit prevention part 50 does not have a pair of conductive layers 15, 15. The other configuration is the same as in the first embodiment.

[0069] In this embodiment, when the short-circuit prevention unit 50 does not include the pair of conductive layers 15, 15 and is composed only of the intermediate layer 13 and the pair of glass plates 11, 12, a short circuit due to the pair of conductive layers 15, 15 does not occur in the short-circuit prevention unit 50. Therefore, the laminated glass 10 can continue to control light stably in areas other than the short-circuit prevention unit 50. As a result, the light control function of the laminated glass 10 can be properly ensured.

[0070] 4 and 5 , in the third embodiment, the short-circuit prevention unit 50 in the second region B of the laminated glass 10 separates the light control unit 20 disposed between the pair of first regions A from the light control unit 20 disposed between the pair of second regions B so that the boundary between the first region A and the second region B is electrically non-conductive in plan view. The other configurations are the same as those in the first embodiment.

[0071] According to this embodiment, the short-circuit prevention unit 50 reduces the curvature of the light control unit 20 disposed between the pair of second regions B, thereby preventing short-circuiting between the pair of conductive layers 15B, 15B in the pair of curved regions 40. Furthermore, because the light control units 20 in the pair of first regions A are separated from the light control units 20 in the pair of second regions B, the light control layer 14A in the first region A and the light control layer 14B in the second region B can be controlled independently. Therefore, even if a short circuit occurs between the pair of conductive layers 15B, 15B in the second region B, making light control by the light control layer 14B impossible, the laminated glass 10 can continue to control light by the light control layer 14A disposed between the pair of first regions A. As a result, the laminated glass 10 can properly maintain its light control function in the specific region (first region A).

[0072] 6 , in the fourth embodiment, the short-circuit prevention part 50 in the second region B of the laminated glass 10 is configured such that the thickness T2 of the switchable layer 14B disposed between a pair of second regions B is larger than the thickness T1 of the switchable layer 14A disposed between a pair of first regions A. The other configurations are the same as those of the first embodiment.

[0073] According to this embodiment, in the pair of second regions B, the presence of the photochromic layer 14B, whose thickness T2 is greater than the thickness T1, ensures a large distance between the pair of conductive layers 15, 15. Therefore, even if wrinkles occur in the photochromic section 20 (the photochromic layer 14B and the pair of conductive layers 15, 15), the pair of conductive layers 15, 15 are maintained spaced apart, preventing short-circuiting due to contact between the pair of conductive layers 15, 15. This allows the laminated glass 10 to stably continue photochromic control using the photochromic layer 14B even in the curved region 40 having the short-circuit prevention section 50. As a result, the laminated glass 10 can appropriately maintain its photochromic function. Here, the thickness T1 is, for example, 5 μm to 150 μm, preferably 5 μm to 100 μm, and more preferably 5 μm to 50 μm. Meanwhile, the thickness T2 is, for example, 50 μm to 500 μm, preferably 30 μm to 200 μm, and more preferably 40 μm to 150 μm.

[0074] 7 and 8 , in the fifth embodiment, a short-circuit prevention part 50 in the second region B of the laminated glass 10 has an insulating member 51 made of rubber, resin, or the like interposed between the light control part 20 (the light control layer 14A and the pair of conductive layers 15A, 15A) between the pair of first regions A and the light control part 20 (the light control layer 14B and the pair of conductive layers 15B, 15B) between the pair of second regions B, so that the boundary between the first region A and the second region B is electrically non-conductive in a plan view. The other configurations are the same as those of the first embodiment.

[0075] According to this embodiment, the insulating member 51 serving as the short-circuit prevention unit 50 reduces the curvature of the switchable layer 14 and the pair of conductive layers 15B, 15B disposed between the pair of second regions B, thereby preventing short-circuiting between the pair of conductive layers 15B, 15B in the pair of curved regions 40. Furthermore, because the switchable units 20 in the pair of first regions A are separated from the switchable units 20 in the pair of second regions B, the switchable layer 14A in the first region A and the switchable layer 14B in the second region B can be controlled independently. Therefore, even if switchable light control by the switchable layer 14B becomes impossible in the second region B due to a short circuit between the pair of conductive layers 15B, 15B, the laminated glass 10 can continue to control light by the switchable layer 14A between the pair of first regions A. As a result, the laminated glass 10 can properly maintain its switchable function in the specific region (first region A).

[0076] [Other Embodiments] (1) In the above embodiment, the second region B of the laminated glass 10 is provided only on the front side in the vehicle longitudinal direction. However, the second region B may be provided on both the front and rear sides in the vehicle longitudinal direction, or only on the rear side. Alternatively, the second region B may be provided on both the left and right sides in the vehicle transverse direction, or only on one side. (2) In the above embodiment, the laminated glass 10 is used as a glass for the vehicle 1. However, the laminated glass 10 may also be used for devices other than vehicles. (3) In the above embodiment, several examples are shown in which the short-circuit prevention portion 50 is provided with a shielding film 16. However, the laminated glass 10 may be configured without providing the short-circuit prevention portion 50 with a shielding film 16.

[0077] The present invention is widely applicable to light control laminated glass.

[0078] DESCRIPTION OF SYMBOLS 10: Light control laminated glass 11: First glass plate 12: Second glass plate 13: Intermediate layer 14, 14A, 14B: Light control layer 15, 15A, 15B: Conductive layer 16: Shielding film 20: Light control portion 31: First intermediate layer (adhesive layer) 32: Second intermediate layer (support layer) 40: Curved region 50: Short circuit prevention portion 51: Insulating member A: First region B: Second region T1, T2: Film thickness

Claims

1. A light control laminated glass comprising: a light control layer capable of adjusting light transmittance by application of a voltage; a pair of conductive layers arranged to sandwich the light control layer and applying the voltage to the light control layer by supplying power; an insulating intermediate layer arranged to sandwich the conductive layer; and a pair of glass plates arranged to sandwich the intermediate layer, each having a first region and a second region with different curvatures, wherein the second region includes a curved region having a smaller radius of curvature than the first region, and a short circuit prevention part is formed between the pair of curved regions to prevent a short circuit due to contact between the pair of conductive layers.

2. The light-control laminated glass according to claim 1, wherein the short-circuit prevention section does not include the light-control layer and the pair of conductive layers, and is composed only of the intermediate layer and the pair of glass plates.

3. The light-control laminated glass according to claim 1, wherein the short-circuit prevention section does not have a pair of the conductive layers, and is composed only of the light-control layer, the intermediate layer, and the pair of the glass plates.

4. The light-control laminated glass according to claim 1, wherein the short-circuit prevention portion separates the light-control layer and the pair of conductive layers arranged between the pair of first regions from the light-control layer and the pair of conductive layers arranged between the pair of second regions so that the boundary between the first region and the second region is electrically non-conductive in a planar view.

5. The light-control laminated glass according to claim 1, wherein the short-circuit prevention section makes the thickness of the light-control layer disposed between a pair of the second regions greater than the thickness of the light-control layer disposed between a pair of the first regions.

6. The light-control laminated glass according to claim 1, wherein the short-circuit prevention section is configured by interposing an insulating member between the light-control layer and the pair of conductive layers arranged between the pair of first regions and the light-control layer and the pair of conductive layers arranged between the pair of second regions, so that the boundary between the first region and the second region is electrically non-conductive in a planar view.

7. The light control laminated glass according to any one of claims 1 to 6, wherein the voltage applied to the light control layer is 30 V or more when the haze value is set to 10% or less.

8. The light control laminated glass according to any one of claims 1 to 7, wherein the light control layer has a film thickness of 5 µm or more and 150 µm or less.

9. The light control laminated glass according to any one of claims 1 to 8, wherein in the second region, the glass plate has a three-dimensional curvature.

10. The light control laminated glass according to any one of claims 1 to 9, wherein the intermediate layer includes a support layer that supports the conductive layer, and an adhesive layer having a smaller Young's modulus than the support layer.

11. The light control laminated glass according to any one of claims 1 to 10, which is disposed on the roof of a vehicle.

12. The light control laminated glass according to claim 11, wherein at least the short circuit prevention portion is provided with a shielding film.

13. The light control laminated glass according to claim 12, wherein the first region is a substantially flat surface having a radius of curvature of 3000 mm or more, and the second region is a curved surface having a radius of curvature of 2000 mm or less.

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