Laminated glass and its manufacturing method, double-insulating glass

Abstract

This laminated glass comprises a pair of glass sheets, an intermediate film disposed between the pair of glass sheets and a light control element enclosed in the intermediate film, wherein: the light control element comprises a pair of substrates and a light control layer disposed between the pair of substrates; the rotational viscosity (γ1) at 25°C of the light control layer is not more than 2000 mPa∙s; and the thickness of the car-interior-side glass sheet, between the pair of glass sheets, is not more than 1 mm.

Description

[Technical field]

[0001] The present invention relates to a laminated glass, a method for producing the same, and insulating glass. [Background technology]

[0002] Laminated glass with an interlayer that contains a light-control element whose transmittance can be changed electrically is known for use in automobile and train windows.

[0003] For example, there is laminated glass in which a light-control element using a low-viscosity liquid crystal as a light-control layer is placed between two glass plates. In this laminated glass, a frame-shaped sealant is placed so as to surround the liquid crystal layer in order to prevent leakage of the liquid crystal material (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-141890 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a light control element using a low-viscosity light control layer is placed between two glass sheets to form laminated glass, color unevenness may occur within the surface of the light control element. In the above laminated glass, color unevenness is addressed by optimizing the thickness of the sealant, but this is not effective enough in improving color unevenness.

[0006] The present invention has been made in view of the above-mentioned points, and has an object to improve color unevenness in laminated glass in which a light control element is sealed in an interlayer film. [Means for solving the problem]

[0007] This laminated glass is Curved shapeA light control device comprising a pair of glass sheets, an interlayer film located between the pair of glass sheets, and a light control element encapsulated in the interlayer film, the light control element comprising a pair of substrates and a light control layer located between the pair of substrates, the light control layer having a rotational viscosity (γ1) of 2000 mPa s or less at 25°C, and a glass sheet on the vehicle interior side of the pair of glass sheets. teeth Plate thickness is 1mm or less Chemically strengthened glass It is. Effect of the Invention

[0008] According to one embodiment of the disclosure, color unevenness can be improved in laminated glass in which a light control element is encapsulated in an interlayer film. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a laminated glass according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view illustrating a pair of glass sheets before being formed into laminated glass. [Diagram 3] FIG. 2 is a perspective view illustrating a curved laminated glass. [Figure 4] FIG. 2 is a diagram illustrating a manufacturing process of laminated glass. [Diagram 5] FIG. 2 is a diagram illustrating a laminated glass according to a first modified example of the first embodiment. [Figure 6] FIG. 6 is a partial cross-sectional view illustrating an example of insulating glass according to a second embodiment. [Figure 7] FIG. 1 is a diagram for explaining an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiment of the present invention will be described with reference to the drawings. In each drawing, the same components are given the same reference numerals, and duplicated explanations may be omitted. In each drawing, the size and shape may be partially exaggerated to make the contents of the present invention easier to understand.

[0011] A vehicle is typically an automobile, but also refers to any moving body having glass, including trains, ships, aircraft, etc.

[0012] In addition, a plan view refers to a specified area of ​​the laminated glass viewed from the normal direction of the surface of the laminated glass facing the vehicle interior, and a planar shape refers to the shape of a specified area of ​​the laminated glass viewed from the normal direction of the surface of the laminated glass facing the vehicle interior.

[0013] First embodiment Fig. 1 is a diagram illustrating a laminated glass according to a first embodiment, and Fig. 1(a) is a schematic diagram showing a state in which the laminated glass is attached to a vehicle and is visually recognized from outside the vehicle interior, and Fig. 1(b) is a cross-sectional view taken along line AA in Fig. 1(a).

[0014] 1, a laminated glass 10 is a laminated glass for vehicles that includes a glass plate 11, a glass plate 12, an interlayer film 13, a shielding layer 14, and a light control element 15. However, the shielding layer 14 is provided as necessary.

[0015] 1, the laminated glass 10 is shown in a flat shape, but the laminated glass 10 may be curved in both the longitudinal and lateral directions. Alternatively, the laminated glass 10 may be curved only in the longitudinal direction or curved only in the lateral direction.

[0016] In addition, in FIG. 1, the laminated glass 10 is rectangular, but the planar shape of the laminated glass 10 is not limited to a rectangular shape and may be any shape including a trapezoidal shape.

[0017] The laminated glass 10 can be used, for example, as a roof glass, rear glass, rear side glass, rear quarter glass, extra glass, windshield, etc. for a vehicle. The extra glass is glass that is attached to the rear side of a vehicle to improve the rear visibility of the driver of the vehicle.

[0018] The glass plate 11 is an interior glass plate that faces the interior side of the vehicle when the laminated glass 10 is installed in the vehicle. The glass plate 12 is an exterior glass plate that faces the exterior side of the vehicle when the laminated glass 10 is installed in the vehicle. The glass plates 11 and 12 may have a predetermined curvature.

[0019] The glass plate 11 and the glass plate 12 are a pair of glass plates facing each other, and the intermediate film 13 and the light control element 15 are located between the pair of glass plates. The glass plate 11 and the glass plate 12 are fixed together with the intermediate film 13 and the light control element 15 sandwiched therebetween.

[0020] The interlayer film 13 is a film that bonds the glass plate 11 and the glass plate 12. The interlayer film 13 includes, for example, an interlayer film 131 that bonds to the glass plate 11, an interlayer film 132 that bonds to the glass plate 12, and a frame-shaped interlayer film 133 that is located between the interlayer film 131 and the interlayer film 132 and surrounds the outer periphery of the light control element 15.

[0021] However, the interlayer film 13 may have an interlayer film 131 bonded to the glass plate 11 and an interlayer film 132 bonded to the glass plate 12, and may not have the interlayer film 133. Even when the interlayer film 133 is not included, the outer periphery of the light control element 15 is surrounded by the interlayer films 131 and / or 132 during pressure bonding in the manufacturing process of the laminated glass 10.

[0022] When there is no need to particularly distinguish between the interlayer films 131, 132, and 133, they will be simply referred to as the interlayer film 13. The glass plate 11, the glass plate 12, and the interlayer film 13 will be described in detail later.

[0023] The shielding layer 14 is an opaque layer, and can be provided, for example, in a strip shape along the peripheral edge of the laminated glass 10. The shielding layer 14 is, for example, an opaque (for example, black) colored ceramic layer. The shielding layer 14 may be a colored interlayer or film having light-shielding properties, or a combination of a colored interlayer and a colored ceramic layer. The colored film may be integrated with an infrared reflective film or the like.

[0024] The presence of the opaque shielding layer 14 in the laminated glass 10 can suppress deterioration due to ultraviolet light of a resin such as urethane that holds the peripheral portion of the laminated glass 10 to the vehicle body. In addition, the electrodes and electrode extraction wiring electrically connected to the light control element 15 can be concealed so as to be difficult to see from the outside and / or inside of the vehicle.

[0025] The shielding layer 14 can be formed, for example, by applying a ceramic color paste containing a fusible glass frit containing a black pigment onto a glass plate by screen printing or the like, and then firing the paste, but is not limited thereto. The shielding layer 14 may also be formed, for example, by applying an organic ink containing a black or dark color pigment onto a glass plate by screen printing or the like, and then drying the ink.

[0026] 1, the shielding layer 14 is provided on the peripheral portion of the interior surface of the glass plate 11. However, the shielding layer 14 may be provided on the peripheral portion of the interior surface of the glass plate 12, or on both the peripheral portion of the interior surface of the glass plate 11 and the peripheral portion of the interior surface of the glass plate 12, as necessary.

[0027] The light control element 15 is an element capable of switching the light transmittance of the laminated glass 10. The light control element 15 may be disposed over substantially the entire laminated glass 10 or over only a portion of the laminated glass 10 as necessary. The planar shape of the light control element 15 is, for example, a rectangle smaller than the planar shape of the laminated glass 10. In the example of Fig. 1, the peripheral portion of the light control element 15 is positioned so as to overlap with the shielding layer 14 in a planar view.

[0028] The light control element 15 includes a base material 151, a conductive film 152, a light control layer 153, a conductive film 154, a base material 155, and a pair of electrodes 156, and is encapsulated in the intermediate film 13. That is, the light control element 15 is covered by the intermediate film 13.

[0029] The light control element 15 is, for example, in the form of a film. The thickness of the light control element 15 is, for example, 0.05 mm or more and 0.5 mm or less, and preferably 0.1 mm or more and 0.4 mm or less. Each of the pair of electrodes 156 of the light control element 15 is connected to an electrode lead-out wiring (not shown) for connecting the electrodes 156 to an external circuit.

[0030] The substrates 151 and 155 are transparent resin layers. The thickness of the substrates 151 and 155 is, for example, 5 μm or more and 500 μm or less, preferably 10 μm or more and 200 μm or less, and more preferably 50 μm or more and 150 μm or less.

[0031] The substrates 151 and 155 are, for example, any one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyamide, polyether, polysulfone, polyethersulfone, polycarbonate, polyarylate, polyetherimide, polyetheretherketone, polyimide, aramid, polybutylene terephthalate, triacetyl cellulose, polyurethane, and cycloolefin polymer.

[0032] The conductive film 152 is formed on the surface of the base material 151 facing the glass plate 12, and is in contact with the surface of the light control layer 153 facing the glass plate 11. The conductive film 154 is formed on the surface of the base material 155 facing the glass plate 11, and is in contact with the surface of the light control layer 153 facing the glass plate 12. In other words, the conductive films 152 and 154 are a pair of conductive films that sandwich the light control layer 153 therebetween.

[0033] For example, a transparent conductive oxide (TCO) can be used as the conductive films 152 and 154. Examples of TCO include, but are not limited to, tin-doped indium oxide (ITO), aluminum doped zinc oxide (AZO), and indium doped cadmium oxide.

[0034] Transparent conductive polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) or poly(4,4-dioctylcyclopentadithiophene) can also be suitably used as the conductive films 152 and 154. Furthermore, as the conductive films 152 and 154, a laminated film of a metal layer and a dielectric layer, silver nanowires, a metal mesh of silver or copper, or the like can also be suitably used.

[0035] The conductive films 152 and 154 can be formed by using, for example, a physical vapor deposition (PVD) method such as a sputtering method, a vacuum deposition method, an ion plating method, etc. The conductive films 152 and 154 may also be formed by a chemical vapor deposition (CVD) method or a wet coating method.

[0036] The light control layer 153 is located between a substrate 151 on which a conductive film 152 is formed and a substrate 155 on which a conductive film 154 is formed. The light control layer 153 is, for example, any one selected from the group consisting of guest-host liquid crystal, twisted nematic (TN) type liquid crystal, phase change (PC) type liquid crystal, super twisted nematic (STN) type liquid crystal, electrically controlled birefringence (ECB) type liquid crystal, optically compensated bend (OCB) type liquid crystal, in-place switching (IPS) type liquid crystal, vertical alignment (VA) type liquid crystal, fringe field switching (FFS) type liquid crystal, field-induced photo-reactive alignment (FPA) type liquid crystal, electrochromic, electrokinetic, organic electroluminescence (EL), and inorganic EL.

[0037] As the light control layer 153, a guest-host liquid crystal is more preferable since it is easy to realize a wide dynamic range and high-speed response.

[0038] The rotational viscosity (γ1) of the light-controlling layer 153 at 25° C. is 2000 mPa·s or less. The rotational viscosity (γ1) of the light-controlling layer 153 at 25° C. is preferably 10 mPa·s to 1000 mPa·s, more preferably 10 mPa·s to 750 mPa·s, more preferably 10 mPa·s to 500 mPa·s, and most preferably 10 mPa·s to 300 mPa·s. By setting the rotational viscosity (γ1) of the light-controlling layer 153 at 25° C. to 1000 mPa·s or less, the response speed can be made faster. In addition, by setting the rotational viscosity (γ1) of the light-controlling layer 153 at 25° C. to 10 mPa·s or more, the light-controlling layer can be made easier to manufacture. The rotational viscosity (γ1) can be measured using a parallel disk type rotational viscometer (B-type viscometer).

[0039] The guest-host liquid crystal is a liquid crystal mixed with a dichroic dye that has anisotropy in light absorption in the long and short axis directions of the molecule. The dichroic dye has a single light absorption axis and absorbs only light that vibrates in the light absorption axis direction. Therefore, the orientation of the dichroic dye can be changed in accordance with the movement of the liquid crystal due to the electric field, and the transmission state of the liquid crystal cell can be changed by controlling the direction of the light absorption axis. As the liquid crystal material, for example, materials described in International Publication No. 2019 / 138791, JP 2018-204018, Japanese Patent No. 5410031, Japanese Patent No. 4214423, and Japanese Patent No. 6117946 may be used. In addition, as the electrochromic material, for example, materials described in U.S. Patent Application No. 2014 / 0205746, U.S. Patent Application No. 2014 / 0205748, U.S. Patent No. 9,207,514, U.S. Patent No. 9,256,111, and U.S. Patent Application No. 2014 / 0272394 may be used.

[0040] The electrode 156 is disposed, for example, at a position overlapping with the shielding layer 14 in a planar view. One of the pair of electrodes 156 is electrically connected to the conductive film 152, and the other is electrically connected to the conductive film 154. Electricity is passed through the conductive films 152 and 154 to drive the light control layer 153.

[0041] One of the pair of electrodes 156 is, for example, a positive electrode, and is connected to the positive side of a power source such as a battery mounted on the vehicle via a lead wire, etc. The other of the pair of electrodes 156 is, for example, a negative electrode, and is connected to the negative side of a power source such as a battery mounted on the vehicle via a lead wire, etc.

[0042] When a voltage is supplied to the light control layer 153 from a power source such as a battery via a pair of electrodes 156, the transmittance of the light control layer 153 changes depending on the voltage. When the transmittance of the light control layer 153 is low, the total light transmittance of the laminated glass 10 is preferably 20% or less. The total light transmittance can be measured by a method in accordance with JIS K 7361-1:1997.

[0043] The material of the electrode 156 is not particularly limited as long as it is a conductive material, and examples of the material include metal materials. Examples of metal materials include gold, silver, copper, aluminum, tungsten, platinum, palladium, nickel, cobalt, titanium, iridium, zinc, magnesium, and tin. These metals may be plated, or may be formed into an alloy or a composite with resin.

[0044] From the viewpoints of cost and availability, copper ribbon, flat-braided copper wire, or FPC (Flexible Printed Circuit) can be suitably used for the electrode 156. The copper ribbon or flat-braided conductor wire may be plated with a metal other than copper.

[0045] The electrode 156 can be joined to the conductive films 152 and 154 by any of a conductive adhesive (conductive adhesive layer), an anisotropic conductive film, and solder. The electrode 156 may also be in direct contact with the conductive films 152 and 154 without using a conductive adhesive, an anisotropic conductive film, or solder. Alternatively, the electrode 156 may be formed by a printing method such as screen printing, inkjet printing, offset printing, flexographic printing, or gravure printing.

[0046] Here, the glass plate 11, the glass plate 12, and the interlayer film 13 will be described in detail.

[0047] [Glass plate] The glass plates 11 and 12 may be inorganic glass or organic glass. As the inorganic glass, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, quartz glass, etc. can be used without any particular limitation. The glass plate 12 located on the outer side of the laminated glass 10 is preferably inorganic glass from the viewpoint of scratch resistance, and is preferably soda-lime glass from the viewpoint of formability. When the glass plates 11 and 12 are soda-lime glass, clear glass, green glass containing a predetermined amount or more of iron components, and UV-cut green glass can be suitably used.

[0048] The inorganic glass may be either unstrengthened glass or tempered glass. Unstrengthened glass is obtained by forming molten glass into a plate shape and slowly cooling it. Tempered glass is obtained by forming a compressive stress layer on the surface of unstrengthened glass.

[0049] The tempered glass may be either physically tempered glass such as air-cooled tempered glass or chemically tempered glass. In the case of physically tempered glass, the glass surface can be tempered by generating a compressive stress layer on the glass surface due to the temperature difference between the glass surface and the inside of the glass by an operation other than slow cooling, such as rapidly cooling a glass sheet uniformly heated in bending from a temperature near the softening point.

[0050] In the case of chemically strengthened glass, for example, after bending, the glass surface can be strengthened by generating a compressive stress on the glass surface by an ion exchange method or the like. Glass that absorbs ultraviolet or infrared rays may be used, and further, although it is preferable that the glass is transparent, a glass plate that is colored to the extent that the transparency is not impaired may be used.

[0051] On the other hand, examples of materials for organic glass include transparent resins such as polycarbonate, acrylic resins such as polymethyl methacrylate, polyvinyl chloride, and polystyrene.

[0052] The shape of the glass plates 11 and 12 is not particularly limited to a rectangular shape, and may be processed into various shapes and curvatures. Gravity forming, press forming, roller forming, etc. are used for bending the glass plates 11 and 12. The forming method of the glass plates 11 and 12 is also not particularly limited, but for example, in the case of inorganic glass, glass plates formed by a float method or the like are preferable.

[0053] Thickness of glass plate 12 is 1 The thickness of the glass plate 12 is preferably 1.1 mm or more and 3 mm or less. If the thickness of the glass plate 12 is 1.1 mm or more, the strength of the glass plate 12 is sufficient for resistance to flying stones, and if the thickness is 3 mm or less, the mass of the laminated glass 10 is not too large, which is preferable in terms of fuel efficiency of the vehicle. is 1 More preferably, the thickness is 0.8 mm or more and 2.8 mm or less, even more preferably, the thickness is 1.8 mm or more and 2.6 mm or less, even more preferably, the thickness is 1.8 mm or more and 2.2 mm or less, even more preferably, the thickness is 1.8 mm or more and 2.0 mm or less.

[0054] The thickness of the glass plate 11 is preferably 0.3 mm or more and 1 mm or less, and more preferably 0.5 mm or more and 0.7 mm or less. When the thickness of the glass plate 11 is 0.3 mm or more, the glass plate 11 is easy to handle and there is little risk of cracking during the production of laminated glass, and when the thickness is 1 mm or less, the mass does not become too large.

[0055] Furthermore, since the thickness of the glass plate 11 is 1 mm or less, the glass plate 11 follows the residual stress generated inside the laminated glass 10 during the production of the laminated glass 10. This reduces the residual stress generated inside the laminated glass 10, and improves the color unevenness of the light control element 15. Here, the color unevenness of the light control element 15 refers to a phenomenon in which the transmittance varies greatly within the plane of the light control element 15, or a phenomenon in which a partially inoperable region occurs, caused by a film thickness deviation of the light control layer 153.

[0056] From the viewpoint of strength, the glass plate 11 having a thickness of 1 mm or less is preferably made of chemically strengthened glass.

[0057] Furthermore, the glass sheets 11 and 12 may be flat or curved. However, if the glass sheets 11 and 12 are curved and the thickness of the glass sheet 11 is not appropriate, forming two sheets of glass with particularly deep curvatures as the glass sheets 11 and 12 will result in a mismatch between the shapes of the two sheets, which will have a significant effect on the glass quality, such as residual stress after compression bonding.

[0058] However, glass quality such as residual stress can be maintained by setting the thickness of the glass sheet 11 to 0.3 mm or more and 1 mm or less. Setting the thickness of the glass sheet 11 to 0.3 mm or more and 1 mm or less is particularly effective in maintaining glass quality in glass that is deeply curved.

[0059] A coating having water repellency and ultraviolet and infrared ray blocking properties, a coating having low reflection properties and low radiation properties, or a coating having condensation prevention properties may be provided on the outer side of the glass plates 11 and / or 12. Furthermore, a coating having ultraviolet and infrared ray blocking properties, low radiation properties, visible light absorption properties, coloring properties, etc. may be provided on the side of the glass plates 11 and / or 12 that contacts the interlayer film 13. Furthermore, the surface of the glass plate 11 facing the vehicle interior may have a low radiation coating.

[0060] That is, the glass plates 11 and / or 12 may have one or more of a water-repellent layer, an ultraviolet blocking layer, an infrared reflective layer, a low reflectance layer, a low emissivity layer, a condensation prevention layer, a visible light absorbing layer, and a colored layer. Note that it is sufficient that at least one of the glass plates 11 and / or 12, the interlayer 13, and the substrates 151 and / or 155 of the light control element 15 has these layers.

[0061] When the glass sheets 11 and 12 are curved inorganic glass, the glass sheets 11 and 12 are bent after being formed by a float method and before being bonded with the interlayer film 13. The bending is performed by softening the glass by heating. The heating temperature of the glass during bending is about 550°C to 700°C.

[0062] [Interlayer] Thermoplastic resins are often used for the intermediate film 13, and examples of such thermoplastic resins include those conventionally used for this type of application, such as 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, ionomer resins, etc. Also suitable for use is a resin composition containing a modified hydrogenated block copolymer, as described in Japanese Patent No. 6065221.

[0063] Among these, plasticized polyvinyl acetal resins are preferably used because they have an excellent balance of various properties such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. These thermoplastic resins may be used alone or in combination of two or more. The term "plasticized" in the plasticized polyvinyl acetal resin means that it is plasticized by adding a plasticizer. The same applies to other plasticized resins.

[0064] However, when the light control element 15 is encapsulated in the intermediate film 13, the encapsulated material may be deteriorated by a specific plasticizer depending on the type of the encapsulated material, and in such a case, it is preferable to use a resin that does not substantially contain the plasticizer. That is, it may be preferable that the intermediate film 13 does not contain a plasticizer. Examples of resins that do not contain a plasticizer include ethylene-vinyl acetate copolymer resins.

[0065] Examples of the polyvinyl acetal resin include polyvinyl formal resin obtained by reacting polyvinyl alcohol (hereinafter, sometimes referred to as "PVA" as necessary) with formaldehyde, polyvinyl acetal resin in the narrow sense obtained by reacting PVA with acetaldehyde, and polyvinyl butyral resin (hereinafter, sometimes referred to as "PVB" as necessary) obtained by reacting PVA with n-butylaldehyde, and the like. In particular, PVB is preferred because it has an excellent balance of various properties such as transparency, weather resistance, strength, adhesive strength, penetration resistance, impact energy absorption, moisture resistance, heat insulation, and sound insulation. These polyvinyl acetal resins may be used alone or in combination of two or more kinds.

[0066] A transparent adhesive film may be used as the intermediate film 13. By using a transparent adhesive film, it is possible to prepare a laminate at room temperature, and it is more preferable to reduce the load on the light control element 15. As the transparent adhesive film, an acrylic resin, a silicone resin, a urethane acrylate resin, an epoxy resin, or the like is used.

[0067] A curable transparent resin may be used as the intermediate film 13. By using a curable transparent resin, a laminate can be produced at low temperature and pressure compared to normal laminated glass processing, and the load on the light control element 15 can be reduced, which is more preferable. As the transparent adhesive film, an acrylic resin, a silicone resin, a urethane acrylate resin, an epoxy resin, or the like is used. In addition, the curing method that can be used includes a photocuring method, a two-component curing method, a heat curing method, a moisture curing method, or the like.

[0068] However, the material forming the intermediate film 13 is not limited to a thermoplastic resin. The material forming the intermediate film 13 may be a thermoplastic resin, a transparent adhesive film, or a curable transparent resin, either singly or in combination. The intermediate film 13 may contain functional particles such as an infrared absorbing agent, an ultraviolet absorbing agent, or a luminescent agent. The intermediate film 13 may have a colored portion called a shade band.

[0069] The thickness of the interlayer film 13 is preferably 0.5 mm or more at its thinnest part. If the thickness of the interlayer film 13 at its thinnest part is 0.5 mm or more, the impact resistance required for laminated glass is sufficient. Furthermore, the thickness of the interlayer film 13 is preferably 3 mm or less at its thickest part. If the maximum thickness of the interlayer film 13 is 3 mm or less, the mass of the laminated glass does not become too large. The maximum thickness of the interlayer film 13 is more preferably 2.8 mm or less, and even more preferably 2.6 mm or less.

[0070] The interlayer film 13 may have four or more layers. For example, the sound insulation of the laminated glass 10 can be improved by forming the interlayer film from four or more layers and making the shear modulus of any layer other than the layers on both sides smaller than the shear modulus of the layers on both sides by adjusting the plasticizer or the like. In this case, the shear modulus of the layers on both sides may be the same or different.

[0071] In addition, it is preferable that the intermediate films 131, 132, and 133 included in the intermediate film 13 are all formed of the same material, but some or all of the intermediate films 131, 132, and 133 may be formed of different materials. In this case, it is preferable that the thickness of each of the intermediate films 131, 132, and 133 is 1 μm or more and 1000 μm or less.

[0072] To produce the interlayer film 13, for example, the above-mentioned resin material that will become the interlayer film is appropriately selected and extruded in a heated and molten state using an extruder. The extrusion conditions, such as the extrusion speed of the extruder, are set so as to be uniform. Thereafter, the extruded resin film is stretched as necessary to give curvature to the upper and lower sides in accordance with the design of the laminated glass, thereby completing the interlayer film 13.

[0073] [Laminated Glass] The total thickness of the laminated glass 10 is preferably 2.8 mm or more and 10 mm or less. If the total thickness of the laminated glass 10 is 2.8 mm or more, sufficient rigidity can be ensured. If the total thickness of the laminated glass 10 is 10 mm or less, sufficient transmittance can be obtained and haze can be reduced.

[0074] The plate misalignment between the glass plates 11 and 12 is preferably 1.5 mm or less, and more preferably 1 mm or less, on at least one side of the laminated glass 10. Here, the plate misalignment between the glass plates 11 and 12 refers to the amount of misalignment between the end of the glass plate 11 and the end of the glass plate 12 in a plan view.

[0075] It is preferable that the misalignment between the glass plates 11 and 12 be 1.5 mm or less along at least one side of the laminated glass 10 in order to avoid impairing the appearance. It is even more preferable that the misalignment between the glass plates 11 and 12 be 1.0 mm or less along at least one side of the laminated glass 10 in order to avoid impairing the appearance.

[0076] [Method for producing laminated glass] (Hot Bend) To manufacture the laminated glass 10, a laminate is prepared by sandwiching the interlayer 13 and the light control element 15 between glass plates 11 and 12. Then, for example, this laminate is placed in a rubber bag and pre-press-bonded at a temperature of about 50° C. to 110° C. in a vacuum with a gauge pressure of −65 kPa to −100 kPa. The heating conditions, temperature conditions, vacuum conditions, and lamination method for the pre-press-bonding are appropriately selected in consideration of the properties of the light control element 15 so as not to cause deterioration during lamination.

[0077] Furthermore, by carrying out a pressure bonding treatment in an autoclave under conditions of, for example, 80 to 150° C. and an absolute pressure of 0.6 MPa to 1.3 MPa, it is possible to obtain a laminated glass 10 with even greater durability. However, in some cases, in order to simplify the process and in consideration of the properties of the material to be filled in the laminated glass 10, this heating and pressurizing step may not be used.

[0078] In the process of preparing the laminate, a first laminate may be prepared by attaching the light control element 15 to the glass plate 12 via an intermediate film 132 which is a part of the intermediate film 13, and a glass plate 11 may be attached to the light control element 15 side of the first laminate via an intermediate film 131 which is a part of the intermediate film 13 to prepare a laminate. In this case, a transparent adhesive film may be used for the intermediate film 13, and the preliminary pressure bonding process may be performed using a roller instead of a rubber bag. The temperature conditions and vacuum conditions are appropriately selected in consideration of the properties of the intermediate film 13 and the light control element 15 so as not to deteriorate during lamination. In particular, lamination at room temperature is preferable because it minimizes the load on the light control element 15. In addition, a frame-shaped intermediate film 133 may be added between the intermediate film 131 and the intermediate film 132 to surround the outer periphery of the light control element 15.

[0079] When the laminated glass 10 has a curved shape, the glass sheets 11 and 12 may be bent by a conventionally known bending method. For example, the glass sheets 11 and 12 may be stacked on top of each other and placed in a ring-shaped mold, heated to a softening point or higher, and bent by their own weight. Alternatively, the glass sheets 11 and 12 may be press-molded individually or together in a heated state.

[0080] This method of manufacturing laminated glass, in which the glass sheets 11 and 12 that have been bent in advance are joined via the interlayer film 13 without being elastically deformed, is also called "hot bending."

[0081] In addition to the interlayer 13 and the light control element 15, a film or device having functions such as heating, infrared reflection, light emission, power generation, light control, touch panel, visible light reflection, scattering, decoration, absorption, etc. may be provided between the glass plates 11 and 12, so long as the effects of the present application are not impaired. Also, the surface of the laminated glass 10 may have a film having functions such as anti-fogging, water repellency, heat shielding, low reflection, etc. Also, the exterior surface of the glass plate 11 and the interior surface of the glass plate 12 may have a film having functions such as heat shielding, heat generation, etc.

[0082] (Cold Bend) The laminated glass 10 may include a glass sheet 12 curved into a first curved shape and a glass sheet 11 having a second shape different from the first curved shape, joined together by an interlayer film 13. In such a laminated glass 10, one or both of the two glass sheets are joined together in an elastically deformed state. Hereinafter, the manufacturing method of laminated glass in which one or both of the two glass sheets are joined together by elastically deforming them is also referred to as "cold bending".

[0083] Fig. 2 is a perspective view illustrating a pair of glass plates before being made into laminated glass, and shows the shapes of glass plate 11 and glass plate 12 before being bonded with interlayer film 13. Fig. 3 is a perspective view illustrating curved laminated glass, and shows the shape after glass plate 11 and glass plate 12 shown in Fig. 2 are bonded with interlayer film 13. Note that illustration of shielding layer 14 and light control element 15 is omitted in Fig. 3.

[0084] If the laminated glass 10 has a single curved shape (cylindrical shape), then if the cross section containing the normal to the center of gravity of the laminated glass 10 is the cross section in which the radius of curvature of the surface of the glass plate 12 facing the vehicle exterior is the largest, then in the cross section, when the bonding by the interlayer 13 is released, the surface of the glass plate 12 facing the vehicle interior will have a smaller radius of curvature than the surface of the glass plate 11 facing the vehicle exterior.

[0085] If the laminated glass 10 has a complex curved shape, then, among the cross sections including the normal to the center of gravity of the laminated glass 10, if the cross section is the section in which the radius of curvature of the surface of the glass sheet 12 facing the vehicle exterior is maximum, and the cross section perpendicular to the cross section is the longitudinal section, then in both the cross section and the longitudinal section, when the bond by the interlayer 13 is released, the surface of the glass sheet 12 facing the vehicle interior will have a smaller radius of curvature than the surface of the glass sheet 11 facing the vehicle exterior.

[0086] Thus, laminated glass 10 in which glass plate 12 curved into a first curved shape and glass plate 11 having a second shape different from the first curved shape are bonded together with interlayer film 13 has bending stress due to elastic deformation. In particular, when glass plate 11 is thinner than glass plate 12, bending stress is generated in glass plate 11 because glass plate 11 is bonded together in a state in which it is mainly elastically deformed. Bending compressive stress is generated near the ends of glass plate 11, and bending tensile stress is generated near the center of glass plate 11.

[0087] The bending compressive stress and bending tensile stress can be measured by a commercially available surface stress meter. When the glass sheet 11 is tempered glass, both residual stress and bending stress occur on the surface of the glass sheet 11 facing the vehicle interior. The residual stress is due to tempering and occurs before bonding. In this case, the bending stress can be calculated by measuring the stress value after bonding and subtracting the stress value of the glass sheet 11 in its natural state from the measured value.

[0088] For example, the glass sheet 12 may be bent by heat into a desired curved shape, and then the chemically strengthened flat glass sheet 11 may be bonded to the glass sheet 12 via the intermediate film 13. For example, the glass sheet 12 may be a complex curved shape curved in two perpendicular directions, and the glass sheet 11 may be flat. By making the first curved shape a complex curved shape, a vehicle window glass with excellent design can be produced, and various needs for vehicle design can be met. By making the second shape a flat shape, it becomes easier to form a functional film. In addition, the bending process of the glass sheet 11 can be omitted.

[0089] The manufacturing method of laminated glass in which one of two glass sheets is elastically deformed to bond them in this way provides the following advantages. That is, in the past, a method was known for obtaining a curved laminated glass 10 having a functional film, in which a functional film was formed on one or both of two flat glass sheets before forming, and then the two glass sheets were heated to near their softening points, bent, and bonded. However, with this method, the functionality of the functional film could be reduced by heating it to near the softening point of the glass sheets.

[0090] On the other hand, if a functional film is formed on a flat glass sheet 11 and then bonded to a glass sheet 12 bent into a desired shape using a cold bend, a curved laminated glass 10 can be obtained without the functional film being heated to near the softening point of the glass sheet, allowing the function of the functional film to be fully exerted.

[0091] Another method for obtaining curved laminated glass with a functional film is to bend a glass sheet into a desired curved shape and then form a functional film on the surface. However, this method is more difficult than forming a functional film on a flat glass sheet, and the process and equipment are complicated. By using cold bending, the functional film can be formed on a flat glass sheet 11, simplifying the process and equipment.

[0092] In addition, by using cold bending, the process of heating the glass sheet 11 to near its softening point and bending it can be omitted. This is particularly effective when the thickness of the glass sheet 11 is 1 mm or less, since it becomes more difficult to maintain the accuracy of bending by heating.

[0093] Furthermore, the glass sheet 11 used in cold bending may have a second curved shape different from the first curved shape. In this embodiment, the radius of curvature of the second curved shape is larger than the radius of curvature of the first curved shape. The glass sheet 11 may be bent into the second curved shape by bending through heating, or may be bent into the second curved shape during a chemical strengthening process.

[0094] Specifically, bending the glass sheet 11 during the chemical strengthening process means that the degree of chemical strengthening on the surface of the glass sheet 11 facing the vehicle exterior is greater than that on the surface of the glass sheet 11 facing the vehicle interior. This allows the glass sheet 11 to be bent so that the surface facing the vehicle exterior is convex and the surface facing the vehicle interior is concave. By bending the glass sheet 11 during the chemical strengthening process in this manner, the process of heating the glass sheet 11 to near its softening point and bending the glass sheet 11 can be omitted. Furthermore, if the glass sheet 11 is curved, the difference in the radius of curvature with the first curved shape becomes smaller, and therefore the bending stress generated during cold bending can be reduced.

[0095] The extent of chemical strengthening becomes clear, for example, by comparing the amount of Na on the vehicle exterior side of glass sheet 11 with the amount of Na on the vehicle interior side. The amount of Na on the vehicle exterior side of glass sheet 11 refers to the intensity of the Kα orbit measured by X-ray fluorescence (XRF), and refers to the amount of Na from the surface of the vehicle exterior side of glass sheet 11 to a depth of 3 μm. The same applies to the vehicle interior side of glass sheet 11.

[0096] Cold bending can be achieved by fixing a laminate of a glass plate 11, an interlayer film 13, a light control element 15, and a glass plate 12 with a temporary fixing means such as tape, and using a conventionally known preliminary pressure bonding device such as a nip roller or a rubber bag, and an autoclave.

[0097] Cold bending can be performed, for example, according to steps S1 to S3 shown in Fig. 4. Step S1 is a bending step. In step S1, a glass sheet 12 (an exterior glass sheet) is heated and bent into a desired shape.

[0098] Step S2 is a step of producing a laminate. In step S2, a flat glass sheet 11 (a glass sheet facing the vehicle interior) is prepared, and the flat glass sheet 11 and a bent glass sheet 12 are laminated with an interlayer film 13 and a light control element 15 interposed therebetween to produce a laminate.

[0099] Step S3 is a pressure bonding step. In step S3, the laminate produced in step S2 is pressurized and heated to pressure bond the glass plates 11 and 12 via the interlayer film 13, and the light control element 15 is encapsulated in the interlayer film 13. Here, the conditions for pressing and heating the laminate are, for example, a temperature of 100 to 150° C. and an absolute pressure of 0.1 to 1.5 MPa.

[0100] In the step of preparing the laminate in step S2, the first laminate may be prepared by attaching the light control element 15 to the bent glass plate 12 via the intermediate film 132 which is a part of the intermediate film 13, and the flat glass plate 11 may be attached to the light control element 15 side of the first laminate via the intermediate film 131 which is a part of the intermediate film 13 to prepare the laminate. In this case, a transparent adhesive film may be used for the intermediate film 13, and the preliminary pressure bonding step may be performed using a roller instead of a rubber bag. The temperature conditions and vacuum conditions are appropriately selected in consideration of the properties of the intermediate film 13 and the light control element 15 so as not to deteriorate during lamination. In particular, lamination at room temperature is preferable because it minimizes the load on the light control element 15. In addition, a frame-shaped intermediate film 133 may be added between the intermediate film 131 and the intermediate film 132 to surround the outer periphery of the light control element 15.

[0101] In addition, in the cold bend, a curved glass sheet 11 having a larger radius of curvature than the glass sheet 12 may be used instead of the flat glass sheet 11 .

[0102] Furthermore, in addition to the interlayer 13 and the light control element 15, a film or device having functions such as heating, infrared reflection, light emission, power generation, light control, touch panel, visible light reflection, scattering, decoration, absorption, etc. may be provided between the glass plates 11 and 12, so long as the effects of the present application are not impaired. Furthermore, the surface of the laminated glass 10 may have a film having functions such as anti-fogging, water repellency, heat shielding, low reflection, etc. Furthermore, the surface of the glass plate 11 facing the vehicle exterior and the surface of the glass plate 12 facing the vehicle interior may have a film having functions such as heat shielding, heat generation, etc.

[0103] In this manner, in the laminated glass 10, since the thickness of the glass plate 11 is 1 mm or less, the stress generated in the laminated glass 10 is alleviated, and color unevenness of the light control element 15 can be improved.

[0104] First Modification of the First Embodiment In the first modification of the first embodiment, an example of laminated glass in which the glass sheet and the light control element on the vehicle interior side are smaller than the glass sheet on the vehicle exterior side is shown. Note that in the first modification of the first embodiment, the description of the same components as those in the already described embodiments may be omitted.

[0105] Fig. 5 is a diagram illustrating a laminated glass according to Modification 1 of the first embodiment, and Fig. 5(a) is a schematic diagram showing a state in which the laminated glass is attached to a vehicle and is visually recognized from outside the vehicle interior, and Fig. 5(b) is a cross-sectional view taken along line BB in Fig. 5(a).

[0106] 5 , the glass sheet 11, interlayer film 13A, and light control element 15 on the vehicle interior side are smaller than the glass sheet 12 on the vehicle exterior side, and are disposed in a partial area of ​​the glass sheet 12. The interlayer film 13A has an interlayer film 131 bonded to the glass sheet 11, and an interlayer film 132 bonded to the glass sheet 12.

[0107] The glass plate 11, the interlayer 13A, and the light control element 15 are approximately the same in size, and in a plan view, the glass plate 12 is exposed in a strip shape on the outer periphery of the laminated portion of the glass plate 11, the interlayer 13A, and the light control element 15. The laminated glass 10A is, for example, a rear side glass.

[0108] In this way, when the light control element 15 is disposed in a partial area of ​​the glass sheet 12 on the vehicle exterior side, the glass sheet 11 and the interlayer 13A on the vehicle interior side may be made approximately the same size as the light control element 15.

[0109] Second Embodiment In the second embodiment, an example of insulating glass using the laminated glass according to the first embodiment will be described. Note that in the second embodiment, the description of the same components as those in the already described embodiments may be omitted.

[0110] Fig. 6 is a partial cross-sectional view illustrating a double-glazing unit according to the second embodiment. The double-glazing unit 20 shown in Fig. 6 has a laminated glass 10, a glass plate 21, and a frame-shaped spacer 22. When the double-glazing unit 20 is installed in a vehicle, the laminated glass 10 faces the inside of the vehicle and the glass plate 21 faces the outside of the vehicle.

[0111] The laminated glass 10 and the glass plate 21 are disposed apart with a spacer 22 sandwiched therebetween, and a hollow layer 23 is formed between the laminated glass 10 and the glass plate 21. A side surface 22a of the spacer 22 is bonded to a surface of the glass plate 12 of the laminated glass 10 facing the hollow layer 23 by a primary sealant 24a. A side surface 22b of the spacer 22 is bonded to a surface of the glass plate 21 facing the hollow layer 23 by a primary sealant 24b. Examples of the primary sealants 24a and 24b include butyl-based sealing materials.

[0112] A secondary sealant 25 is attached to the edge between the laminated glass 10 and the glass plate 21. This seals the hollow layer 23 sandwiched between the laminated glass 10 and the glass plate 21. Examples of the secondary sealant 25 include a silicone-based sealant, a polysulfide-based sealant, a polyurethane-based sealant, and a butyl-based sealant.

[0113] The spacer 22 is formed of, for example, a hollow pipe material, and a hollow portion 221 of the spacer 22 is filled with a desiccant 26 such as zeolite. The spacer 22 is also formed with a through hole 222 connecting the hollow portion 221 and the hollow layer 23, whereby the gas in the hollow layer 23 is dried by the desiccant 26. The hollow layer 23 may be filled in advance with a heat insulating gas (an inert gas such as argon gas or krypton gas) which is a functional gas. Filling the hollow layer 23 in advance with a heat insulating gas improves the heat insulating properties of the insulating glass 20.

[0114] Furthermore, a low-E (Low Emissivity) film, which is a low-emissivity film for improving heat shielding and heat insulation, may be coated on the surface of the glass plate 12 of the laminated glass 10 facing the hollow layer 23 and on the surface of the glass plate 21 facing the hollow layer 23. The glass plate 21 may be so-called float glass produced by a float method, or may be fireproof glass such as wired glass. The glass plate 21 may also be laminated glass.

[0115] In this way, the laminated glass 10 according to the first embodiment can be used to realize the insulating glass 20, which can provide excellent heat insulating and heat blocking properties.

[0116] Furthermore, when the insulating glass 20 is installed in a vehicle, the laminated glass 10 faces the inside of the vehicle, and in the laminated glass 10, the thickness of the glass sheet 11 facing the innermost side of the vehicle is 1 mm or less, and the rotational viscosity (γ1) of the light control layer 153 at 25° C. is 2000 mPa s or less. This reduces stress generated in the laminated glass 10, improving color unevenness of the light control element 15 and providing good responsiveness of the light control element 15. In other words, the insulating glass 20 provides good color unevenness and responsiveness of the light control element 15, and has excellent heat insulating performance and heat blocking performance.

[0117] The laminated glass 10 may be disposed on the vehicle exterior side, and the glass plate 21 may be disposed on the vehicle interior side to form a double-glazed glass. In this case, the glass plate 11 of the laminated glass 10 is disposed so as to be in contact with the hollow layer 23. In this case as well, the glass plate 11 of the laminated glass 10 that is the innermost side of the vehicle has a thickness of 1 mm or less, and the rotational viscosity (γ1) of the light control layer 153 at 25° C. is 2000 mPa·s or less. This reduces stress generated in the laminated glass 10, improves color unevenness of the light control element 15, and provides good responsiveness of the light control element 15. In other words, a double-glazed glass is obtained that provides good color unevenness and responsiveness of the light control element 15, and has excellent heat insulating and heat blocking performance.

[0118] In this way, the insulating glass according to the second embodiment is a insulating glass in which two glass members are arranged apart with a spacer therebetween and the peripheral edges of the two glass members are sealed with a sealant, and any one of the two glass members may be laminated glass 10. Alternatively, laminated glass 10A may be used instead of laminated glass 10.

[0119] [Example] Examples will be described below, but the present invention is not limited to these examples in any way.

[0120] (Example 1) A glass sheet (inside the vehicle) that would become the inner plate when laminated glass was prepared, and a glass sheet (outside the vehicle) that would become the outer plate were prepared (manufactured by AGC, commonly known as VFL). The dimensions of the inside glass sheet were 300 mm long x 300 mm wide x 0.7 mm thick. The dimensions of the outside glass sheet were 300 mm long x 300 mm wide x 2 mm thick.

[0121] Next, a guest-host liquid crystal was prepared as a light control element. The dimensions of the guest-host liquid crystal were 250 mm long x 250 mm wide x 0.28 mm thick.

[0122] The rotational viscosity (γ1) of the light-controlling layer of the guest-host liquid crystal was measured using a parallel disk type rotational viscometer (B-type viscometer) at a rotation speed of 20 rpm (V 20rpm ) and viscosity at a rotation speed of 2 rpm (V 2rpm ) was measured. The arithmetic mean ((V 20rpm +V 2rpm ) / 2) was defined as the rotational viscosity (γ1) (mPa s).

[0123] The rotational viscosity (γ1) of the guest-host liquid crystal light-control layer at 25°C was 100 mPa·s. Two interlayer films (Solutia Japan PVB, thickness 0.38 mm) were also prepared.

[0124] Then, a laminated glass for evaluation was produced by hot bending. Specifically, first, the glass plate on the inside of the vehicle and the glass plate on the outside of the vehicle were bent to form a desired curved shape. Next, a laminate was produced by sandwiching one interlayer film, a guest-host liquid crystal, and the other interlayer film in this order between the curved glass plate on the inside of the vehicle and the curved glass plate on the outside of the vehicle. Next, the laminate was placed in a rubber bag and bonded at a temperature of about 70 to 110°C in a vacuum with a gauge pressure of -65 kPa to -100 kPa. Then, the laminated glass for evaluation was produced by heating and pressing under conditions of a temperature of 100°C to 150°C and an absolute pressure of 0.6 MPa to 1.3 MPa.

[0125] (Example 2) A laminated glass for evaluation was produced in the same manner as in Example 1, except that the thickness of the glass sheet on the vehicle interior side was 2 mm.

[0126] (Example 3) A laminated glass for evaluation was produced in the same manner as in Example 1, except that the glass sheet on the vehicle interior side had a sheet thickness of 1 mm.

[0127] (Example 4) A laminated glass for evaluation was produced in the same manner as in Example 1, except that the glass sheet on the vehicle interior side had a sheet thickness of 0.55 mm.

[0128] (Example 5) Laminated glass for evaluation was prepared in the same manner as in Example 1, except that a liquid crystal having a rotational viscosity (γ1) of 500 mPa·s at 25°C in the light control layer was used instead of the guest-host liquid crystal, and the glass sheet on the inside of the vehicle was made 0.55 mm thick. Laminated glass for evaluation was prepared in the same manner as in Example 1, except that an electrochromic having a rotational viscosity (γ1) of 500 mPa·s at 25°C in the light control layer was used instead of the guest-host liquid crystal, and the glass sheet on the inside of the vehicle was made 0.55 mm thick.

[0129] (Example 6) Laminated glass for evaluation was prepared in the same manner as in Example 1, except that a liquid crystal having a light-controlling layer with a rotational viscosity (γ1) at 25°C of 2000 mPa·s was used instead of the guest-host liquid crystal, and the glass sheet on the vehicle interior side was made 0.55 mm thick. Laminated glass for evaluation was prepared in the same manner as in Example 1, except that an electrochromic having a light-controlling layer with a rotational viscosity (γ1) at 25°C of 2000 mPa·s was used instead of the guest-host liquid crystal, and the glass sheet on the vehicle interior side was made 0.55 mm thick.

[0130] (Example 7) Laminated glass for evaluation was prepared in the same manner as in Example 1, except that a liquid crystal having a light-controlling layer with a rotational viscosity (γ1) at 25°C of 3000 mPa·s was used instead of the guest-host liquid crystal, and the glass sheet on the vehicle interior side was made 0.55 mm thick. Laminated glass for evaluation was prepared in the same manner as in Example 1, except that an electrochromic having a light-controlling layer with a rotational viscosity (γ1) at 25°C of 3000 mPa·s was used instead of the guest-host liquid crystal, and the glass sheet on the vehicle interior side was made 0.55 mm thick.

[0131] (Example 8) A laminated glass for evaluation was produced in the same manner as in Example 1, except that the interlayer was a transparent adhesive film having a thickness of 0.125 mm (OCA8146-5 manufactured by 3M).

[0132] Specifically, a first laminate was produced by attaching a light control element to a bent glass plate on the vehicle exterior side via a transparent adhesive film, and a flat glass plate on the vehicle interior side was attached to the light control element side of the first laminate via another transparent adhesive film to produce a final laminate. Both the first laminate and the final laminate were produced by laminating them at room temperature with a roller.

[0133] (evaluation) For each of the laminated glasses for evaluation prepared in Examples 1 to 8, whether or not color unevenness occurred within the surface of the light control element was visually confirmed from the glass plate side on the vehicle interior side, and those that had color unevenness were marked with × (fail), and those that did not have color unevenness were marked with ◯ (pass). Furthermore, for those that did not have color unevenness, the quality of orange peel (uneven reflection on the substrate surface of the light control element) resulting from undulations in the substrate of the light control element was compared, and those with inconspicuous orange peel were marked with ◎.

[0134] The responsiveness was evaluated for each of the laminated glasses for evaluation produced in Examples 1 to 8. Specifically, the "response speed" was measured when the light control element was switched from ON to OFF at 0°C, and a "response speed" longer than 5 seconds was evaluated as ×, a "response speed" longer than 2 seconds and less than 5 seconds was evaluated as ◯, and a "response speed" less than 2 seconds was evaluated as ◎. Here, the "response speed" is defined as the time it takes for the transmitted light intensity to reach 80% of the maximum transmitted light change width when a laser beam with a wavelength of 543.5 nm is irradiated onto each of the laminated glasses for evaluation and the change in the transmitted light intensity is measured every 0.1 seconds.

[0135] The evaluation results of color unevenness and responsiveness are shown in Figure 7, together with the rotational viscosity (γ1) of the light-control layer at 25°C, the thickness of the glass plate on the inside of the vehicle, and the type of interlayer film.

[0136] As shown in Figure 7, regardless of the rotational viscosity (γ1) of the light-adjusting layer at 25°C, when the thickness of the glass sheet on the vehicle interior side was 1 mm or less, no color unevenness occurred within the surface of the light-adjusting element, and the evaluation result for color unevenness was pass (◯ or ◎). On the other hand, when the thickness of the glass sheet on the vehicle interior side was greater than 1 mm, color unevenness occurred within the surface of the light-adjusting element, and the evaluation result for color unevenness was fail (×).

[0137] In addition, when the superiority or inferiority of orange peel was compared for those in which no color unevenness occurred, it was confirmed that the orange peel was improved when a laminated glass was manufactured using a transparent adhesive film.

[0138] Furthermore, the evaluation result of responsiveness was passed (◯ or ◎) when the rotational viscosity (γ1) of the photochromic layer at 25°C was 2000 mPa·s or less. In particular, when the rotational viscosity (γ1) of the photochromic layer at 25°C was 500 mPa·s or less, the evaluation result of responsiveness was ◎, confirming that the responsiveness was good. On the other hand, when the rotational viscosity (γ1) of the photochromic layer at 25°C was greater than 2000 mPa·s, the evaluation result of responsiveness was failed (×).

[0139] These results suggest that if the thickness of the glass sheet on the inside of the vehicle is 1 mm or less and the rotational viscosity (γ1) of the light-control layer at 25°C is 2000 mPa s or less, then the in-plane color unevenness in the light-control element can be suppressed and good responsiveness can be obtained.

[0140] In addition, when the thickness of the glass sheet on the vehicle interior side is 1 mm or less and a transparent adhesive film is used to manufacture the laminated glass, it is possible to suppress color unevenness in the surface of the light control element and improve orange peel. This is thought to be because, when a transparent adhesive film is used to manufacture the laminated glass, pressure bonding can be performed at room temperature, so there is no difference in the shrinkage rate between the substrate of the light control element and the interlayer film due to heat, and waviness of the substrate of the light control element is reduced.

[0141] Although preferred embodiments have been described above in detail, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0142] This international application claims priority based on Japanese Patent Application No. 2019-190248, filed on October 17, 2019, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0143] 10, 10A Laminated Glass 11, 12, 21 Glass plates 13, 13A, 131, 132, 133 Intermediate film 14 Shielding layer 15 Light control element 20. Double Glazing 22 Spacer 22a, 22b Sides of spacer 22 23 Hollow layer 24a, 24b Primary sealant 25 Secondary sealing material 26 Dry material 151, 155 Base material 152, 154 Conductive film 153 dimming layer 156 Electrode 221 Hollow 222 Through hole

Claims

1. A pair of curved glass plates; an interlayer film positioned between the pair of glass sheets; A light control element is encapsulated in the intermediate film, The light control element includes a pair of substrates and a light control layer located between the pair of substrates, The light control layer has a rotational viscosity (γ1) at 25° C. of 2000 mPa·s or less, and the vehicle-side glass plate of the pair of glass plates is a chemically strengthened glass having a plate thickness of 1 mm or less.

2. 2. The laminated glass according to claim 1, wherein the light control layer has a rotational viscosity (γ1) at 25° C. of 300 mPa·s or less.

3. The laminated glass according to claim 1 or 2, wherein the light control layer is a guest-host liquid crystal.

4. 3. The laminated glass according to claim 1, wherein the light control layer is any one selected from the group consisting of TN type liquid crystal, PC type liquid crystal, STN type liquid crystal, ECB type liquid crystal, OCB type liquid crystal, IPS type liquid crystal, VA type liquid crystal, FFS type liquid crystal, FPA type liquid crystal, electrochromic, electrokinetic, organic EL, and inorganic EL.

5. The laminated glass according to claim 1 , wherein the total light transmittance is 20% or less when the light control layer has a low transmittance.

6. 6. The laminated glass according to claim 1, wherein at least one of the pair of glass plates, the interlayer film, and the pair of base materials has one or more of an infrared reflective layer, a low emissivity layer, a water repellent layer, a condensation prevention layer, and an ultraviolet blocking layer.

7. The laminated glass according to claim 1 , further comprising a low-emissivity coating on an interior surface of the interior glass sheet.

8. 8. The laminated glass according to claim 1, wherein the interior glass sheet and the light control element are smaller than the exterior glass sheet and are disposed in a partial area of ​​the exterior glass sheet.

9. 9. The laminated glass according to claim 1, wherein the interlayer film is any one selected from the group consisting of 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.

10. The laminated glass according to claim 1 , wherein the interlayer film comprises a transparent adhesive film or a curable transparent resin.

11. 11. The laminated glass according to claim 1, wherein the interlayer has a thickness of 0.5 mm or more at its thinnest portion and 3 mm or less at its thickest portion.

12. 12. The laminated glass according to claim 1, wherein the pair of base materials is any one selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyamide, polyether, polysulfone, polyethersulfone, polycarbonate, polyarylate, polyetherimide, polyetheretherketone, polyimide, aramid, polybutylene terephthalate, triacetyl cellulose, polyurethane, and cycloolefin polymer.

13. A laminated glass according to any one of claims 1 to 12, having bending stress.

14. A laminated glass described in any one of claims 1 to 13, wherein the thickness of the glass plate on the outer side of the pair of glass plates is 1.1 mm or more and 3 mm or less.

15. A laminated glass described in any one of claims 1 to 14, having a total thickness of 2.8 mm or more and 10 mm or less.

16. heating and bending the exterior glass sheet into a desired shape; laminating an interior-side glass sheet and the bent exterior-side glass sheet via an interlayer film and a light control element to produce a laminate in which the exterior-side glass sheet and the interior-side glass sheet have a curved shape; and applying pressure and heat to the laminate to pressure-bond the interior side glass sheet and the exterior side glass sheet together via the interlayer film. The light control element includes a pair of substrates and a light control layer located between the pair of substrates, The method for producing laminated glass, wherein the light control layer has a rotational viscosity (γ1) at 25° C. of 2000 mPa·s or less, and the vehicle interior glass sheet is a chemically strengthened glass having a sheet thickness of 1 mm or less.

17. 17. The method for producing laminated glass according to claim 16, wherein in the step of producing the laminate, a first laminate is produced by attaching the light control element to the bent exterior glass sheet via a first interlayer film that becomes part of the interlayer film, and then the interior glass sheet is attached to the light control element side of the first laminate via a second interlayer film that becomes part of the interlayer film, to produce the laminate.

18. 18. The method for producing laminated glass according to claim 17, wherein in the step of producing the laminate, at least one of the first interlayer film and the second interlayer film is a transparent adhesive film, and at least one of the first laminate and the laminate is produced by bonding them together using a roller.

19. The interior glass sheet before lamination has a second shape different from the curved shape of the exterior glass sheet, The method for producing laminated glass according to claim 16 , wherein, in the step of producing the laminate, at least the interior-side glass sheet of the vehicle exterior glass sheet and the vehicle interior glass sheet is elastically deformed.

20. A method for manufacturing laminated glass as described in claim 19, wherein the second shape is a curved shape having a radius of curvature larger than the radius of curvature of the exterior glass plate of the vehicle, or a flat shape.

21. A double-glazing unit comprising two glass members spaced apart from each other with a spacer therebetween, and the peripheral edges of the two glass members are sealed with a sealant, An insulating glass, wherein one of the two glass members is the laminated glass according to any one of claims 1 to 15.

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