Dimming device and method for manufacturing the same, and liquid crystal device

Abstract

To provide a liquid crystal device that can suppress the occurrence of liquid crystal unevenness. [Solution] The dimming device (10) comprises a first transparent substrate (11), a second transparent substrate (12), a dimming cell (20) disposed between the first transparent substrate (11) and the second transparent substrate (12), a first bonding layer (13) disposed between the first transparent substrate (11) and the dimming cell (20), and a second bonding layer (14) disposed between the second transparent substrate (12) and the dimming cell (20). The first bonding layer (13) and the second bonding layer (14) are bonding bodies containing non-pressure adhesive components. The first bonding layer (13) is OCR, and the second bonding layer (14) is OCA.

Description

Technical Field

[0001] The present disclosure relates to a dimming device, a method for manufacturing the same, and a liquid crystal device.

Background Art

[0002] Conventionally, a dimming member using liquid crystal, which can be used for an electronic blind or the like that controls the transmission of external light in combination with a light-transmitting member such as a window, and a dimming device using such a dimming member have been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when manufacturing a dimming device, a laminated structure including a pair of glass plates, a dimming cell located between the glass plates, and a bonding body provided between each glass plate and the dimming cell is heated under a high-pressure environment by an autoclave or the like (this pressure bonding process). Further, in order to prevent the quality of the dimming device from being impaired by a foaming phenomenon that may occur in the intermediate film of the dimming device, the above laminated structure may be heated in a vacuum environment prior to the heat treatment by an autoclave (temporary pressure bonding process and degassing process).

[0005] When the dimming cell is sandwiched between a pair of glass plates under such high temperature and high pressure, it is not easy to apply a uniform pressure over the entire surface of the dimming cell through each glass plate. If the pressure applied to the surface of the dimming cell through each glass plate becomes non-uniform, a liquid crystal accumulation, which is a phenomenon in which the liquid crystal of the dimming cell is locally unevenly distributed, may occur. The liquid crystal accumulation deteriorates the dimming performance of the dimming cell and impairs the appearance of the dimming device.

[0006] Furthermore, if the completed dimming device is exposed to a high-temperature environment, the interlayer will soften, while the substrate and liquid crystal of the dimming cell will expand slightly. As a result, the suppressive force of the interlayer holding the dimming cell will weaken, which may cause the aforementioned liquid crystal accumulation. Also, if a vertically positioned dimming device is exposed to a high-temperature environment, the liquid crystal of the dimming cell may fall due to gravity, potentially causing a localized change in the thickness of the liquid crystal layer of the liquid crystal film. In other words, gravity will increase the amount of liquid crystal towards the bottom in the vertical direction, increasing the thickness of the liquid crystal layer. In this case, the amount of liquid crystal and dye will be greater in the lower vertical portion, which may cause unevenness within the surface of the dimming component.

[0007] This embodiment provides a dimming device, a method for manufacturing the same, and a liquid crystal device that can suppress the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present, and also suppress the phenomenon in which liquid crystal is unevenly distributed downward in the vertical direction due to gravity.

[0008] Furthermore, liquid crystal devices such as dimming devices utilize a configuration that includes a pair of glass plates, liquid crystal cells placed between these glass plates, and bonding layers provided between each glass plate and liquid crystal cell.

[0009] However, if a completed liquid crystal display is exposed to a high-temperature environment, the bonding layer softens, while the substrate, liquid crystal, and bonding layer of the liquid crystal cell expand. As a result, the positional regulating force of the bonding layer that maintains the shape of the liquid crystal cell weakens, and there is a risk of liquid crystal accumulation, a phenomenon in which the liquid crystal of the liquid crystal cell is locally unevenly distributed. Liquid crystal accumulation degrades the performance of the liquid crystal cell and impairs the appearance of the liquid crystal display.

[0010] Furthermore, if a vertically positioned liquid crystal display (LCD) device is exposed to a high-temperature environment, the liquid crystal in the LCD cell may fall due to gravity, potentially causing localized changes in the thickness of the liquid crystal layer of the LCD film. In other words, gravity increases the amount of liquid crystal towards the lower vertical side of the LCD device, increasing the thickness of the liquid crystal layer. In this case, the amount of liquid crystal and dye increases in the lower vertical portion of the LCD device, potentially causing unevenness within the surface of the LCD cell.

[0011] This embodiment provides a dimming device, a method for manufacturing the same, and a liquid crystal device that can suppress the occurrence of liquid crystal accumulation even when exposed to a high-temperature environment.

[0012] Furthermore, during the manufacturing of the liquid crystal device described above, if the curing shrinkage rate of the bonding layer is large, the curing shrinkage of the bonding layer can cause unevenness in the thickness of the liquid crystal layer, such as liquid crystal accumulation, where the liquid crystal of the liquid crystal cell is locally unevenly distributed when the curing of the bonding layer is complete. This can result in localized "liquid crystal accumulation areas" that are significantly thicker than other areas, leading to unevenness in the liquid crystal layer thickness and resulting in liquid crystal irregularities.

[0013] Furthermore, if the completed liquid crystal device is exposed to a high-temperature environment, the bonding layer will soften, while the substrate, liquid crystal, and bonding layer of the liquid crystal cell will expand. As a result, the positional regulating force of the bonding layer that maintains the shape of the liquid crystal cell will weaken, which may cause unevenness in the liquid crystal.

[0014] The objective of this embodiment is to provide a liquid crystal device that can suppress the occurrence of liquid crystal unevenness. [Disclosure of the Invention]

[0015] The dimming device according to this embodiment comprises a first transparent substrate, a second transparent substrate, a dimming cell disposed between the first transparent substrate and the second transparent substrate, a first bonding layer disposed between the first transparent substrate and the dimming cell, and a second bonding layer disposed between the second transparent substrate and the dimming cell, wherein the first bonding layer and the second bonding layer are bonding bodies containing non-pressure adhesive components.

[0016] In the dimming device according to this embodiment, the first bonding layer and the second bonding layer may each be OCA.

[0017] In the dimming device according to this embodiment, an outer peripheral film may be arranged around the dimming cell, between the first bonding layer and the second bonding layer.

[0018] In the dimming device according to the present embodiment, the outer peripheral film may have a shape in which a part of the shape corresponding to the outer periphery of the dimming cell is removed.

[0019] In the dimming device according to the present embodiment, it may not include a bonding body containing a pressure-sensitive adhesive component.

[0020] In the dimming device according to the present embodiment, a third bonding layer may be disposed between the first transparent substrate and the first bonding layer.

[0021] In the dimming device according to the present embodiment, a film may be disposed between the third bonding layer and the first bonding layer.

[0022] In the dimming device according to the present embodiment, the first bonding layer may be OCR, and the second bonding layer may be OCA.

[0023] The method for manufacturing a dimming device according to the present embodiment includes a step of preparing a second transparent substrate, a step of bonding a second bonding layer onto the second transparent substrate, a step of bonding a dimming cell onto the second bonding layer, a step of bonding a first bonding layer onto the dimming cell, and a step of bonding a first transparent substrate onto the first bonding layer, and the first bonding layer and the second bonding layer are each a bonding body containing a non-pressure-sensitive adhesive component.

[0024] The method for manufacturing a dimming device according to the present embodiment includes a step of preparing a second transparent substrate, a step of bonding a second bonding layer onto the second transparent substrate, a step of bonding a dimming cell onto the second bonding layer, a step of applying a first bonding material onto the dimming cell, a step of bonding a first transparent substrate onto the first bonding material, and a step of forming a first bonding layer by curing the first bonding material, and the first bonding layer and the second bonding layer are each a bonding body containing a non-pressure-sensitive adhesive component.

[0025] According to the embodiments of this disclosure, it is possible to suppress the occurrence of liquid crystal accumulation, which is a phenomenon in which a large amount of liquid crystal is locally present, and to suppress the phenomenon in which liquid crystal is unevenly distributed downward in the vertical direction due to gravity.

[0026] The dimming device according to this embodiment comprises a first transparent substrate, a second transparent substrate, a dimming cell disposed between the first transparent substrate and the second transparent substrate, a first OCR layer disposed between the first transparent substrate and the dimming cell, and a second OCR layer disposed between the second transparent substrate and the dimming cell.

[0027] In the dimming device according to this embodiment, a third OCR layer in the shape of a picture frame is arranged between the first transparent substrate and the second transparent substrate so as to surround the dimming cell in a plan view.

[0028] In the dimming device according to this embodiment, the first OCR layer may be integrated with the third OCR layer.

[0029] In the dimming device according to this embodiment, the resin curing shrinkage rate of the first OCR layer and the second OCR layer may be 2.3% or less, preferably 2.0% or less.

[0030] In the dimming device according to this embodiment, it is not necessary to include a bonding body containing a pressure-adhesive component.

[0031] In the dimming device according to this embodiment, a first interface is formed between the first OCR layer and the dimming cell, and a second interface is formed between the second OCR layer and the dimming cell, and the second interface may be flatter than the first interface.

[0032] The method for manufacturing a dimming device according to this embodiment includes the steps of: preparing a second transparent substrate; applying a second OCR material onto the second transparent substrate; laminating a dimming cell onto the second OCR material; forming a second OCR layer by curing the second OCR material; preparing a first transparent substrate; applying a first OCR material onto the first transparent substrate; bonding the first transparent substrate to the dimming cell using the first OCR material; and forming a first OCR layer by curing the first OCR material.

[0033] The method for manufacturing a dimming device according to this embodiment includes the steps of: preparing a second transparent substrate; applying a second OCR material onto the second transparent substrate; pre-curing the second OCR material; laminating a dimming cell onto the pre-cured second OCR material; preparing a first transparent substrate; applying a first OCR material onto the first transparent substrate; laminating the first transparent substrate to the dimming cell using the first OCR material; forming a first OCR layer by curing the first OCR material and forming a second OCR layer by curing the second OCR material.

[0034] In the method for manufacturing a dimming device according to this embodiment, the process may further include a step of applying a second OCR material onto the second transparent substrate and then laminating a protective film onto the second OCR material.

[0035] According to the embodiments of this disclosure, it is possible to suppress the occurrence of liquid crystal accumulation, which is a phenomenon in which a large amount of liquid crystal is locally present, and to suppress the phenomenon in which liquid crystal is unevenly distributed downward in the vertical direction due to gravity.

[0036] This embodiment is a liquid crystal device comprising a first transparent substrate, a second transparent substrate, a liquid crystal cell disposed between the first transparent substrate and the second transparent substrate, a first bonding layer disposed between the first transparent substrate and the liquid crystal cell, and a second bonding layer disposed between the second transparent substrate and the liquid crystal cell, wherein the thickness of the first bonding layer in a first end-side region that overlaps with one end of the liquid crystal cell in a plan view is greater than the thickness of the first bonding layer in an inner region adjacent to the first end-side region and extending to the other side opposite to the one side.

[0037] In this embodiment, the liquid crystal device is such that the thickness of the first bonding layer is thickest at a position overlapping one end of the liquid crystal cell.

[0038] This embodiment is a liquid crystal device in which the thickness of the first bonding layer in the second end-side region adjacent to the inner region and extending to the other side is greater than the thickness of the first bonding layer in the inner region.

[0039] This embodiment is a liquid crystal device in which the first bonding layer is OCR and the second bonding layer is OCR or OCA.

[0040] In this embodiment, the liquid crystal device satisfies the relationship t1 / t0 ≥ 1.2, where t1 is the average layer thickness of the first end-side region located in the range of 0 mm or more and less than 80 mm from the position corresponding to the end of the liquid crystal cell over which the first end-side region overlaps, and t0 is the average layer thickness of the inner region located in the range of 80 mm or more and less than 180 mm from the position corresponding to the end of the liquid crystal cell over which the first end-side region overlaps.

[0041] According to this embodiment, it is possible to provide a liquid crystal device that can suppress the occurrence of liquid crystal accumulation even when exposed to a high-temperature environment.

[0042] This embodiment comprises a first transparent substrate, a second transparent substrate, a liquid crystal cell disposed between the first and second transparent substrates, having a liquid crystal layer and having a smaller planar size than the first and second transparent substrates, a first bonding layer disposed between the first transparent substrate and the liquid crystal cell and having a larger planar size than the liquid crystal cell, and a second bonding layer disposed between the second transparent substrate and the liquid crystal cell and having a larger planar size than the liquid crystal cell, wherein the first bonding layer is an OCR, and the cross-sectional area of ​​the liquid crystal layer along the vertical direction when the liquid crystal device is positioned vertically so that the plate surface is aligned with the direction of gravity, assuming actual usage conditions, is X(mm 2 The liquid crystal device satisfies the relationship Y≧110X-170, where Y (μm) is the thickness of the first bonding layer in the area overlapping with the liquid crystal cell.

[0043] In this embodiment, the average linear expansion coefficient of the OCR of the first bonding layer in the liquid crystal apparatus from 25°C to 85°C is 24.7(E -5 It is a liquid crystal device with a temperature of 0°C or higher.

[0044] This embodiment is a liquid crystal device comprising a third bonding layer, which is an OCR layer, located between the first bonding layer and the second bonding layer and provided around the liquid crystal cell, wherein the peripheral region of the first bonding layer located outside the liquid crystal cell and the width of the third bonding layer are 10 mm or more.

[0045] According to this embodiment, a liquid crystal device is provided that can suppress the occurrence of liquid crystal accumulation even when exposed to a high-temperature environment.

[0046] This embodiment is a liquid crystal device comprising a first transparent substrate, a second transparent substrate, a liquid crystal cell disposed between the first and second transparent substrates, a first bonding layer disposed between the first transparent substrate and the liquid crystal cell, and a second bonding layer disposed between the second transparent substrate and the liquid crystal cell, wherein the first bonding layer is OCR, and the change V from the storage modulus E1 at a normal temperature of 25°C to the storage modulus E2 at a high temperature of 85°C is 0% or more and 30% or less. However, V = 1 - (E2 / E1).

[0047] This embodiment is a liquid crystal device in which the change amount V is 2.7% or more and 22.7% or less.

[0048] This embodiment is a liquid crystal device in which the curing shrinkage rate of the first bonding layer is 2.3% or less.

[0049] This embodiment is a liquid crystal device that does not include a bonding body containing a pressure-adhesive component.

[0050] According to this embodiment, a liquid crystal device can be provided that can suppress the occurrence of liquid crystal unevenness. [Brief explanation of the drawing]

[0051] [Figure 1] Figure 1 is a perspective view showing a dimming device according to the first embodiment. [Figure 2] Figure 2 is a cross-sectional view showing a dimming device according to the first embodiment. [Figure 3] Figure 3 is an exploded perspective view showing a dimming device according to the first embodiment. [Figure 4] Figures 4(a)-(d) are cross-sectional views showing a method for manufacturing a dimming cell. [Figure 5] Figures 5(a)-(c) are cross-sectional views showing a method for manufacturing a dimming cell. [Figure 6] Figures 6(a)-(f) are cross-sectional views showing a method for manufacturing a dimming device according to the first embodiment. [Figure 7] Figure 7 is a cross-sectional view showing a first modified example of the dimming device according to the first embodiment. [Figure 8] Figure 8 is a cross-sectional view showing a second modified example of the dimming device according to the first embodiment. [Figure 9] Figures 9(a)-(d) are plan views showing modified examples of the outer film, respectively. [Figure 10] Figure 10 is a cross-sectional view showing a dimming device according to a second embodiment. [Figure 11] Figures 11(a)-(g) are cross-sectional views showing a method for manufacturing a dimming device according to a second embodiment. [Figure 12] Figure 12 is a cross-sectional view showing a dimming device according to a third embodiment. [Figure 13] Figure 13 is an exploded perspective view showing a dimming device according to a third embodiment. [Figure 14] Figures 14(a)-(h) are cross-sectional views showing a method for manufacturing a dimming device according to a third embodiment. [Figure 15] Figures 15(a)-(h) are cross-sectional views showing a method for manufacturing a dimming device according to a first modification of the third embodiment. [Figure 16] Figure 16 is a cross-sectional view showing a modified example of the third embodiment of a dimming device. [Figure 17] Figures 17(a)-(i) are cross-sectional views showing a method for manufacturing a dimming device according to a second modification of the third embodiment. [Figure 18] This is an exploded perspective view showing the configuration of the liquid crystal device 101 according to the fourth embodiment. [Figure 19] This is a cross-sectional view showing the layer configuration of the liquid crystal device 101 according to the fourth embodiment. [Figure 20] This is a cross-sectional view showing a method for manufacturing a liquid crystal device 101 according to a fourth embodiment. [Figure 21] This figure shows a comparative example liquid crystal device 101X, in which no difference in layer thickness is provided in the first bonding layer 131, in a vertical position and exposed to a high-temperature environment. [Figure 22] Figure 21 shows the liquid crystal device 101X in a plan view. [Figure 23] This figure shows the thickness distribution of the first bonding layer 131 in Example 1. [Figure 24] This figure shows the thickness distribution of the first bonding layer 131 in Example 2. [Figure 25] This figure shows the thickness distribution of the first bonding layer 131 in Comparative Example 1. [Figure 26] This diagram illustrates the first end region 131b and the inner region 131a in a plan view. [Figure 27] This figure shows the results of evaluating the occurrence of liquid crystal accumulation after exposure to the high-temperature environment described above for each of Example 1, Example 2, and Comparative Example 1. [Figure 28] This figure summarizes the results of evaluating the effect of t1 / t0 on liquid crystal accumulation. [Figure 29] This is a cross-sectional view showing the layer configuration of the liquid crystal device 101 according to the fifth embodiment. [Figure 30] This figure shows a comparative example liquid crystal device 101X, in which the thickness of the central region 131d is not set to an appropriate thickness, in a vertical position and exposed to a high-temperature environment. [Figure 31] Figure 30 shows a plan view of the liquid crystal device 101X. [Figure 32] This figure shows the results of evaluating the occurrence of liquid crystal accumulation by changing the cross-sectional area of ​​the liquid crystal layer 114 and the thickness of the first bonding layer 131. [Figure 33] This graph shows the cross-sectional area of ​​the liquid crystal layer 114 and the range in which liquid crystal accumulation is suppressed. [Figure 34] This figure shows the results of evaluating whether or not liquid crystal accumulation occurs in a high-temperature environment by changing the average linear expansion coefficient of the OCR used in the first bonding layer 131. [Figure 35] This figure shows the results of evaluating the occurrence of liquid crystal accumulation D1 by changing the peripheral region 131e of the first bonding layer 131 and the width Wa of the third bonding layer 133. [Figure 36] This is an exploded perspective view showing the configuration of the liquid crystal device 101 according to the sixth embodiment. [Figure 37] This is a cross-sectional view showing the layer configuration of the liquid crystal device 101 according to the sixth embodiment. [Figure 38] This figure shows a method for manufacturing a liquid crystal device 101 according to the sixth embodiment. [Figure 39] This figure shows the comparative example liquid crystal device 101X in a vertical position exposed to a high-temperature environment. [Figure 40] Figure 39 shows a plan view of the liquid crystal device 101X. [Modes for carrying out the invention]

[0052] (First Embodiment) The first embodiment will be described below with reference to Figures 1 to 9.

[0053] The dimming device 10 described below can be applied to various technical fields where adjustment of light transmittance is required, and its scope of application is not particularly limited. The dimming device 10 is placed, for example, in areas where light needs to be adjusted (areas where external light enters, such as windows on the front, sides, rear, or roof of buildings, such as windowpanes, showcases, indoor transparent partitions, vehicle windows, or interior partition boards of vehicles). This makes it possible to control the amount of light incident on the inside of buildings or vehicles, or to control the amount of light incident on a predetermined area inside a building or vehicle.

[0054] The dimming device 10 described below is merely an example of one embodiment. Therefore, for example, some of the elements listed below as components of the dimming device 10 may be replaced with other elements, or may not be included at all. Also, elements not listed below may be included as components of the dimming device 10. Furthermore, in the drawings, for the convenience of illustration and ease of understanding, the scale and dimensional ratios, etc., have been appropriately changed or exaggerated from those of the actual objects.

[0055] (Dimming device) Figure 1 shows a dimming device (laminated glass) 10 according to this embodiment. The dimming device 10 according to this embodiment is composed of a three-dimensional shape having a curved surface shape. In Figure 1, as an example, the dimming device 10 has a shape that is convex on one side. The dimming device 10 is not limited to this, and for example, the surface shape may be planar (i.e., flat plate), or the surface shape may be a two-dimensional shape having a curved surface shape (for example, a shape that constitutes part of a cylinder). Here, a three-dimensional shape is not a simple cylindrical surface, but a curved surface that cannot be constructed by simply deforming a plane without stretching or shrinking. A three-dimensional shape is distinguished from a two-dimensional shape (two-dimensional curved surface) that is curved two-dimensionally around a single axis, or a two-dimensional shape (two-dimensional curved surface) that is curved two-dimensionally around multiple axes that are parallel to each other with different curvatures. In other words, a three-dimensional shape is a shape made up of a surface that is partially or entirely curved around each of multiple axes that are inclined relative to each other. In this specification, "plan view" refers to the view of the dimming device 10 from a direction perpendicular to the main surface.

[0056] As shown in Figure 1, the dimming device 10 according to this embodiment comprises a first glass plate 11, a first bonding layer 13, a dimming cell 20, a second bonding layer 14, and a second glass plate 12. The first glass plate 11, the first bonding layer 13, the dimming cell 20, the second bonding layer 14, and the second glass plate 12 are stacked in this order.

[0057] Figure 2 is a cross-sectional view showing the layer configuration of the dimming device 10 according to this embodiment, and Figure 3 is an exploded perspective view showing the layer configuration of the dimming device 10 according to this embodiment. Although the dimming device 10 in this embodiment has a three-dimensional surface shape, Figures 2 and 3 show the case where the surface shape of the dimming device 10 is planar for ease of understanding.

[0058] As shown in Figure 2, the dimming device 10 comprises a first glass plate 11, a second glass plate 12, and a dimming cell 20 disposed between the first glass plate 11 and the second glass plate 12. The dimming cell 20 comprises a first laminate 21 including a first substrate 24, a first transparent electrode 25, and a first alignment layer 26, a second laminate 22 including a second substrate 27, a second transparent electrode 28, and a second alignment layer 29, and a liquid crystal layer 23 disposed between the first laminate 21 and the second laminate 22.

[0059] The first glass plate (first transparent substrate) 11 and the second glass plate (second transparent substrate) 12 are glass plates with high light transmittance, respectively, and are arranged on the front and back surfaces of the dimming device 10. The first glass plate 11 and the second glass plate 12 have a three-dimensional shape with a curved surface, and are pre-formed to have a curved shape that is convex on one side (see Figure 1). In this case, the first glass plate 11 and the second glass plate 12 are formed such that the first glass plate 11 side is convex relative to the second glass plate 12 side, but this is not limited to this, and the second glass plate 12 side may be formed such that the second glass plate 12 side is convex relative to the first glass plate 11 side. In this embodiment, the first glass plate 11 and the second glass plate 12 have a thickness of 0.5 mm or more and 4 mm or less, and as an example, glass plates with a thickness of 2 mm are used for both. The first glass plate 11 and the second glass plate 12 may be inorganic glass or resin glass. As resin glass, for example, polycarbonate, acrylic, etc. can be used. When inorganic glass is used for the first glass plate 11 and the second glass plate 12, the dimming device 10 can be made with excellent heat resistance and scratch resistance. On the other hand, when resin glass is used for the first glass plate 11 and the second glass plate 12, the dimming device 10 can be made lighter. Furthermore, the first glass plate 11 and the second glass plate 12 may be subjected to surface treatment such as a hard coat as needed. In addition, transparent resin substrates may be used instead of the first glass plate 11 and the second glass plate 12.

[0060] The first bonding layer 13 is positioned between the first glass plate 11 and the dimming cell 20, and is a component that bonds the first glass plate 11 and the dimming cell 20 together. Similarly, the second bonding layer 14 is positioned between the second glass plate 12 and the dimming cell 20, and is a component that bonds the second glass plate 12 and the dimming cell 20 together.

[0061] In this embodiment, the first bonding layer 13 and the second bonding layer 14 are each a bond containing a non-pressure adhesive component. Here, a "bond containing a non-pressure adhesive component" refers to a bond that does not require pressure to properly adhere to adjacent objects and is capable of adhering to adjacent objects to a reasonable degree under normal pressure. Examples of a "bond containing a non-pressure adhesive component" include optically transparent resins such as OCA or OCR, and curing resins (e.g., thermosetting resins, room-temperature curing resins, two-component mixed resins, ultraviolet curing resins, and electron beam curing resins).

[0062] In this embodiment, the first bonding layer 13 and the second bonding layer 14 may each be composed of OCA (Optical Clear Adhesive). The OCA is a layer produced, for example, as follows: First, a liquid curable adhesive layer composition containing a polymerizable compound is applied to a release film such as polyethylene terephthalate (PET), and this is cured using, for example, ultraviolet light (UV) to obtain an OCA sheet. The curable adhesive layer composition may be an optical adhesive such as an acrylic resin, a silicone resin, or a urethane resin. After bonding this OCA sheet to an object, the release film is peeled off to obtain a layer made of the OCA. The first bonding layer 13 and the second bonding layer 14 made of OCA each have optical transparency, and it is preferable that they also have heat resistance up to at least about 120°C, heat and humidity resistance, and weather resistance.

[0063] In this embodiment, the first bonding layer 13 directly bonds the first glass plate 11 and the dimming cell 20. The second bonding layer 14 directly bonds the second glass plate 12 and the dimming cell 20. However, the embodiment is not limited to this, and a film such as an ultraviolet (UV) cut film may be interposed between the first bonding layer 13 and the dimming cell 20, and / or between the second bonding layer 14 and the dimming cell 20.

[0064] The thicknesses of the first bonding layer 13 and the second bonding layer 14 may be appropriately selected depending on the material, etc. Specifically, the thicknesses of the first bonding layer 13 and the second bonding layer 14 may be 30 μm or more and 500 μm or less, and preferably 50 μm or more and 200 μm or less. The size of the first bonding layer 13 and the second bonding layer 14 may be the same as the size of the first glass plate 11 and the second glass plate 12, respectively, or they may be larger than the first glass plate 11 and the second glass plate 12. Furthermore, the first bonding layer 13 and the second bonding layer 14 may be made of the same material or they may be made of different materials.

[0065] As shown in Figures 2 and 3, an outer peripheral film 19 is positioned around the dimming cell 20, between the first bonding layer 13 and the second bonding layer 14. The outer peripheral film 19 is bonded to the first bonding layer 13 and the second bonding layer 14. The outer peripheral film 19 is a frame-shaped resin layer in plan view, more specifically having a square shape (a square shape with the center cut out), or a shape with a part of the square shape removed (described later). The outer peripheral film 19 may be made of any of the materials listed as materials used for the first base material 24 and the second base material 27, which will be described later, and it is preferable to use a resin film such as polyethylene terephthalate (PET). By providing the outer peripheral film 19, it is possible to prevent the side surface of the dimming cell 20 or a part thereof from being exposed to the side surface of the dimming device 10, and to suppress the intrusion of moisture, etc. from the side surface of the dimming device 10, thereby further improving the water-impermeable properties of the dimming device 10.

[0066] The outer peripheral film 19 is a layer formed in cross-sectional view on the thickness portion of the dimming cell 20 when the first bonding layer 13 and the second bonding layer 14 are larger than the dimming cell 20 (in plan view). The outer peripheral film 19 is formed to surround the dimming cell 20 in plan view and has a frame-like shape with the shape of the dimming cell 20 cut out from the shapes of the first bonding layer 13 and the second bonding layer 14. In this case, the outer peripheral film 19 is formed in the portion between the first bonding layer 13 and the second bonding layer 14, corresponding to the periphery of the dimming cell 20.

[0067] The outer circumference of the outer film 19 may be the same size as the outer circumference of the first glass plate 11 and the second glass plate 12, or it may be larger than the outer circumference of the first glass plate 11 and the second glass plate 12. The inner circumference of the outer film 19 may be the same size as the outer circumference of the dimming cell 20, or it may be larger than the outer circumference of the dimming cell 20. The width Wa of the outer film 19 (see Figure 3) is preferably greater than 0 mm and less than or equal to 1 / 4 of the glass width. The thickness of the outer film 19 may be 50 μm or more and 500 μm or less, and is preferably 200 μm or more and 300 μm or less. Alternatively, the outer film 19 may be omitted if the side surface or part thereof of the dimming cell 20 is not exposed from the side surface of the dimming device 10.

[0068] The dimming cell 20 (dimming film, liquid crystal film) is a film that can control the amount of transmitted light by changing the applied voltage. The dimming cell 20 is positioned so as to be sandwiched between the first glass plate 11 and the second glass plate 12. This dimming cell 20 has a guest-host type liquid crystal layer using a dichroic dye and is a component that changes the amount of transmitted light by an electric field applied to the liquid crystal. The dimming cell 20 comprises a film-like first laminate 21, a film-like second laminate 22, and a liquid crystal layer 23 positioned between the first laminate 21 and the second laminate 22.

[0069] As shown in Figure 2, the first laminate 21 is formed by laminating a first substrate 24, a first transparent electrode 25, and a first orientation layer 26. That is, the first substrate 24, the first transparent electrode 25, and the first orientation layer 26 are stacked in this order from the first bonding layer 13 side. The second laminate 22 is formed by laminating a second substrate 27, a second transparent electrode 28, and a second orientation layer 29. That is, the second substrate 27, the second transparent electrode 28, and the second orientation layer 29 are stacked in this order from the second bonding layer 14 side.

[0070] Furthermore, a plurality of bead spacers 31 are arranged between the first laminate 21 and the second laminate 22. The liquid crystal layer 23 is filled between the plurality of bead spacers 31 between the first laminate 21 and the second laminate 22. The plurality of bead spacers 31 may be arranged irregularly or regularly.

[0071] The dimming cell 20 changes the orientation of the liquid crystal material made of a guest host liquid crystal composition provided in the liquid crystal layer 23 by driving the first transparent electrode 25 and the second transparent electrode 28 provided in the first laminate 21 and the second laminate 22, thereby changing the amount of transmitted light.

[0072] The first substrate 24 and the second substrate 27 are made of transparent resin and can be fitted with a flexible film. It is desirable that the first substrate 24 and the second substrate 27 be transparent resin films with low optical anisotropy and a transmittance of 80% or more in the visible wavelength range (380 nm to 800 nm). Examples of materials for the transparent resin film include acetylcellulose resins such as triacetylcellulose (TAC), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene (PE), polypropylene (PP), polystyrene, polymethylpentene, and EVA, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, acrylic resins, polyurethane resins, polysulfone (PSF), polyethersulfone (PES), polycarbonate (PC), polyether (PE), polyetherketone (PEK), (meth)acronitrile, cycloolefin polymer (COP), and cycloolefin copolymer. As the material for the transparent resin film, resins such as polycarbonate, cycloolefin polymer, and polyethylene terephthalate are particularly preferred. The thickness of the transparent resin film used as the first substrate 24 and the second substrate 27 can be appropriately selected within the range in which the transparent resin film is flexible, although this depends on the material. The thickness of the first substrate 24 and the second substrate 27 may be 50 μm or more and 200 μm or less, respectively. In this embodiment, a polyethylene terephthalate film with a thickness of 125 μm is used as an example of the first substrate 24 and the second substrate 27.

[0073] The first transparent electrode 25 and the second transparent electrode 28 are each composed of a transparent conductive film laminated on the first substrate 24 and the second substrate 27 (transparent resin film), respectively. Various transparent electrode materials applicable to this type of transparent resin film can be used as the transparent conductive film, including transparent metal thin films with an oxide-based total light transmittance of 50% or more. Examples include tin oxide-based, indium oxide-based, and zinc oxide-based films.

[0074] Examples of tin oxide (SnO2)-based materials include NESA (tin oxide SnO2), ATO (Antimony Tin Oxide: antimond-doped tin oxide), and fluorine-doped tin oxide. Examples of indium oxide (In2O3)-based materials include indium oxide, ITO (Indium Tin Oxide: indium tin oxide), and IZO (Indium Zinc Oxide). Examples of zinc oxide (ZnO)-based materials include zinc oxide, AZO (aluminum-doped zinc oxide), and gallium-doped zinc oxide. In this embodiment, the transparent conductive films constituting the first transparent electrode 25 and the second transparent electrode 28 are formed of ITO.

[0075] The bead spacer 31 is a component that defines the thickness (cell gap) of the liquid crystal layer 23 excluding the outer periphery. In this embodiment, a spherical bead spacer is used as the bead spacer 31. The diameter of the bead spacer 31 may be in the range of 1 μm to 20 μm, preferably 3 μm to 15 μm. The bead spacer 31 can be made of a wide range of materials, including inorganic materials such as silica, organic materials, or a core-shell structure combining these. In addition to a spherical shape, the bead spacer may also be made of rod shapes such as cylindrical, elliptical, or polygonal prism shapes. The bead spacer 31 is manufactured from a transparent material, but the color may be adjusted by applying a colored material as needed.

[0076] In this embodiment, the bead spacer 31 is provided on the second laminate 22, but it is not limited to this, and may be provided on both the first laminate 21 and the second laminate 22, or only on the first laminate 21. Also, the bead spacer 31 is not necessarily provided. Alternatively, a columnar spacer may be used instead of the bead spacer 31, or together with the bead spacer 31.

[0077] The first orientation layer 26 and the second orientation layer 29 are components for aligning the liquid crystal molecules contained in the liquid crystal layer 23 in a desired direction. The first orientation layer 26 and the second orientation layer 29 are formed by photo-alignment layers. The photo-alignment material applicable to the photo-alignment layer can be a wide variety of materials to which photo-alignment methods can be applied, such as photodegradable, photodimerizable, and photoisomerizable materials. In this embodiment, a photodimerizable material is used. Examples of photodimerizable materials include polymers containing cinnamate, coumarin, benzylidenephthalimidine, benzylideneacetophenone, diphenylacetylene, stilbazole, uracil, quinolinone, maleimide, or cinnamyridene acetate derivatives. Among these, polymers containing cinnamate, coumarin, or both are preferred because they have good orientation-regulating power.

[0078] In addition, a rubbing orientation layer may be used instead of the photo-alignment layer. With respect to the rubbing orientation layer, the rubbing treatment may be omitted, or the rubbing treatment may be performed to create a fine linear uneven shape and produce the orientation layer. In this embodiment, the dimming cell 20 is equipped with a first orientation layer 26 and a second orientation layer 29, but it is not limited to this, and a configuration without the first orientation layer 26 and the second orientation layer 29 is also possible.

[0079] The liquid crystal layer 23 can be broadly composed of a guest-host liquid crystal composition or a dichroic dye composition. The guest-host liquid crystal composition may contain a chiral agent so that when the liquid crystal material is horizontally oriented, it is oriented in a spiral shape in the thickness direction of the liquid crystal layer 23. In addition, a sealing material 32, which is annular or frame-shaped in plan view, is arranged between the first laminate 21 and the second laminate 22 so as to surround the liquid crystal layer 23. This sealing material 32 holds the first laminate 21 and the second laminate 22 together and prevents leakage of the liquid crystal material. The sealing material 32 can be a thermosetting resin such as epoxy resin or acrylic resin, or an ultraviolet curing resin.

[0080] The dimming cell 20 is configured as normally clear, with the first alignment layer 26 and the second alignment layer 29 being vertical alignment layers with a pre-tilt alignment restricting force set in a certain direction, so that the orientation of the guest host liquid crystal composition when light is blocked becomes the same as when an electric field is applied. Alternatively, the setting when light is transmitted may be set to the state when an electric field is applied, resulting in a normally dark configuration. Here, normally dark is a structure in which the transmittance is minimized when no voltage is applied to the liquid crystal, resulting in a black screen. Normally clear is a structure in which the transmittance is maximized when no voltage is applied to the liquid crystal, resulting in a transparent screen.

[0081] In this embodiment, the dimming cell 20 is shown as an example comprising a guest-host type liquid crystal layer 23, but it is not limited to this. The dimming cell 20 may also be configured to include a liquid crystal layer 23 such as a TN (Twisted Nematic), VA (Vertical Alignment), or IPS (In-Plane-Switching) type that does not use a dichroic dye composition. When such a liquid crystal layer 23 is provided, the dimming cell can function as a dimming film by further providing linear polarizing layers on the surfaces of the first substrate 24 and the second substrate 27, respectively.

[0082] In this embodiment, as described above, a first bonding layer 13 is placed between the first glass plate 11 and the dimming cell 20, and a second bonding layer is placed between the second glass plate 12 and the dimming cell 20. The first bonding layer 13 bonds the first glass plate 11 and the dimming cell 20 to each other, and the second bonding layer 14 bonds the second glass plate 12 and the dimming cell 20 to each other. As a result, even if the dimming device 10 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the heat-resistant OCA will not soften, and the occurrence of liquid crystal accumulation, a phenomenon in which the liquid crystal of the dimming cell 20 is unevenly distributed, can be suppressed.

[0083] Preferably, the dimming device 10 does not contain a bonding body containing a pressure-bonding adhesive component. An example of a bonding body containing a pressure-bonding adhesive component is an interlayer made of PVB (polyvinyl butyral) resin. Therefore, an interlayer made of PVB resin or the like is not interposed between the first glass plate 11, the dimming cell 20, and the second glass plate 12, and it is possible to suppress the uneven distribution of liquid crystals in the dimming cell 20 due to the softening of the interlayer made of PVB resin or the like at high temperatures. Note that "a bonding body containing a pressure-bonding adhesive component" refers to a bonding body that requires pressurization (i.e., a pressure greater than normal pressure) in order to properly bond to adjacent objects. Normal pressure is ambient pressure, which is usually equal to atmospheric pressure and can be standard atmospheric pressure.

[0084] As shown in Figure 3, the dimming device 10 is connected to a dimming controller 91, and a sensor device 92 and a user operation unit 93 are connected to the dimming controller 91. The dimming controller 91 controls the dimming state of the dimming device 10, and can switch between blocking and transmitting light by the dimming device 10, or change the light transmittance in the dimming device 10. Specifically, the dimming controller 91 is connected to the external electrode substrate 35 of the dimming device 10, and by adjusting the electric field applied to the liquid crystal layer 23 of the dimming device 10 to change the orientation of liquid crystal molecules in the liquid crystal layer 23, it can switch between blocking and transmitting light by the dimming device 10, or change the light transmittance.

[0085] The dimming controller 91 can adjust the electric field applied to the liquid crystal layer 23 based on any method. The dimming controller 91 can adjust the electric field applied to the liquid crystal layer 23 in response to, for example, the measurement results of the sensor device 92 or instructions (commands) input by the user via the user operation unit 93, thereby switching between blocking and transmitting light by the dimming device 10, or changing the light transmittance. Therefore, the dimming controller 91 may automatically adjust the electric field applied to the liquid crystal layer 23 according to the measurement results of the sensor device 92, or it may be manually adjusted according to instructions from the user via the user operation unit 93. The object to be measured by the sensor device 92 is not particularly limited; for example, the brightness of the usage environment may be measured, in which case the switching between blocking and transmitting light by the dimming device 10 or the change in light transmittance will be performed according to the brightness of the usage environment. Furthermore, it is not necessarily required that both the sensor device 92 and the user operation unit 93 be connected to the dimming controller 91; only one of the sensor device 92 or the user operation unit 93 may be connected.

[0086] The external electrode substrate 35 is sandwiched between the first laminate 21 and the second laminate 22. In the region where the external electrode substrate 35 is formed, the first laminate 21 and the second laminate 22 have electrode protrusions 36 that project outward in the planar direction. The external electrode substrate 35 is embedded inside the electrode protrusions 36. As shown by the arrows in Figure 3, the external electrode substrate 35 and the electrode protrusions 36 are sandwiched between the outer peripheral film 19 and the second bonding layer 14, and protrude outward from the outer peripheral film 19 and the second bonding layer 14. However, the external electrode substrate 35 and the electrode protrusions 36 may also be sandwiched between the outer peripheral film 19 and the first bonding layer 13.

[0087] (Manufacturing method for dimmable cells) Next, the method for manufacturing the dimming cell 20 of the dimming device 10 according to this embodiment will be explained using Figures 4(a)-(d) and 5(a)-(c). Figures 4(a)-(d) and 5(a)-(c) are cross-sectional views showing the method for manufacturing the dimming cell 20 according to this embodiment.

[0088] First, as shown in Figure 4(a), a second substrate 27 supplied in a roll is prepared. Next, as shown in Figure 4(b), a second transparent electrode 28 made of, for example, ITO is formed on the second substrate 27 by sputtering using a sputtering apparatus. At this time, the transparent electrode may be patterned to form a predetermined pattern shape.

[0089] Next, as shown in Figure 4(c), a coating solution for the second orientation layer 29 is applied to the second substrate 27 on which the second transparent electrode 28 is formed, and then exposed to light to produce the second orientation layer 29. In this way, a second laminate 22 is prepared in which the second substrate 27, the second transparent electrode 28, and the second orientation layer 29 are laminated together.

[0090] Furthermore, a first laminate 21 is prepared by laminating the first substrate 24, the first transparent electrode 25, and the first orientation layer 26 in the same manner as shown in Figures 4(a)-(c).

[0091] Next, as shown in Figure 4(d), bead spacers 31 are placed on the second orientation layer 29 of the second laminate 22. In addition to wet / dry spraying, various placement methods can be widely applied to the bead spacers 31. For example, a coating liquid prepared by dispersing the bead spacers 31 together with a resin component in a solvent may be partially applied, followed by drying and firing processes to randomly place the bead spacers 31 on the second orientation layer 29 and hold them in place, making them difficult to move. Although not shown, the outer circumference of the bead spacers 31 may be covered with the second orientation layer 29. Specifically, by mixing the bead spacers 31 with the coating liquid related to the second orientation layer 29 to form the second orientation layer 29, the bead spacers 31 can be thinly covered and held by the second orientation layer 29.

[0092] Next, as shown in Figure 5(a), a sealing material 32 is applied to the second orientation layer 29 of the second laminate 22 by a dispenser or screen printing. This sealing material 32 is applied in a frame shape so as to surround the area where the liquid crystal layer 23 is to be produced.

[0093] Next, as shown in Figures 5(b) and 5(c), the second laminate 22 and the first laminate 21 are stacked on top of each other, and the liquid crystal layer 23 is placed. During this process, first, as shown in Figure 5(b), the liquid crystal constituting the liquid crystal layer 23 is dropped into the area surrounded by the sealing material 32. At this time, the liquid crystal layer 23 is inside the sealing material 32 and fills the area around the bead spacer 31.

[0094] Next, as shown in Figure 5(c), the second laminate 22 on which the liquid crystal layer 23 is placed and the pre-prepared first laminate 21 are stacked on top of each other and pressed together. After that, the sealing material 32 is partially cured by irradiation with ultraviolet light, and then heated to integrate the first laminate 21 and the second laminate 22. After that, the laminate of the first laminate 21 and the second laminate 22 produced in this way is trimmed to the desired size. Note that the sealing material 32 may be one that hardens by irradiation with ultraviolet light alone and does not require heating.

[0095] As described above, it is preferable to stack the second laminate 22 and the first laminate 21 on each other after placing the liquid crystal layer 23, but the method is not limited to this, and the liquid crystal layer 23 may be placed after stacking the second laminate 22 and the first laminate 21 on each other. Subsequently, by attaching an external electrode substrate 35 (see Figure 3) between the first laminate 21 and the second laminate 22, the dimming cell 20 according to this embodiment is obtained.

[0096] (Manufacturing method for dimming devices) Next, the method for manufacturing the dimming device 10 according to this embodiment will be described using Figures 6(a)-(f). Figures 6(a)-(f) are cross-sectional views showing the method for manufacturing the dimming device 10 according to this embodiment.

[0097] First, prepare the second glass plate 12 as shown in Figure 6(a).

[0098] Next, a second bonding layer 14 made of OCA is bonded onto the second glass plate 12. In this case, for example, an OCA sheet having the second bonding layer 14 and a release film 46 is first bonded to the second glass plate 12, and then the release film 46 is peeled off to bond the second bonding layer 14 onto the second glass plate 12. The second bonding layer 14 may be bonded to the entire area or a part of one side of the second glass plate 12.

[0099] Next, the dimming cell 20 described above is bonded onto the second bonding layer 14, and the dimming cell 20 is bonded to the second glass plate 12 by the second bonding layer 14 (Figure 6(c)). The second bonding layer 14, which is made of OCA, is a bonding body that contains a non-pressure adhesive component as described above. Therefore, the dimming cell 20 and the second glass plate 12 are bonded without pressure (i.e., under ambient pressure (usually under atmospheric pressure)). Furthermore, the second bonding layer 14 is bonded to the dimming cell 20 and the second glass plate 12 at room temperature (for example, between 10°C and 30°C).

[0100] Next, a frame-shaped outer film 19 is laminated onto the second bonding layer 14 around the dimming cell 20, and the outer film 19 is laminated to the second glass plate 12 by the second bonding layer 14 (Figure 6(d)). The outer film 19 is preferably made of a resin film such as polyethylene terephthalate (PET). The second bonding layer 14, made of OCA, is a bond containing a non-pressure adhesive component as described above. Therefore, the outer film 19 is bonded to the second glass plate 12 via the second bonding layer 14 without pressure and at room temperature.

[0101] Next, a first bonding layer 13 made of OCA is laminated onto the dimming cell 20 and the outer film 19 (Figure 6(e)). In this case, for example, an OCA sheet having the first bonding layer 13 and a release film 46 is first laminated onto the dimming cell 20 and the outer film 19, and then the release film 46 is peeled off to laminate the first bonding layer 13 onto the dimming cell 20 and the outer film 19.

[0102] Next, the first glass plate 11 is prepared and bonded onto the first bonding layer 13 (Figure 6(f)). This bonds the first glass plate 11 to the dimming cell 20 and the outer film 19 using the first bonding layer 13. The first bonding layer 13, made of OCA, is a bonding body containing a non-pressure adhesive component, as described above. Therefore, the dimming cell 20 and the outer film 19 and the first glass plate 11 are bonded without pressure (i.e., under ambient pressure (usually atmospheric pressure)). Furthermore, the first bonding layer 13 is bonded to the dimming cell 20, the outer film 19 and the first glass plate 11 at room temperature (for example, 10°C to 30°C). In this way, a dimming device 10 is obtained in which the first glass plate 11, the first bonding layer 13, the dimming cell 20, the second bonding layer 14 and the second glass plate 12 are laminated together.

[0103] As described above, according to this embodiment, a first bonding layer 13 is placed between the first glass plate 11 and the dimming cell 20, and a second bonding layer 14 is placed between the second glass plate 12 and the dimming cell 20. The first bonding layer 13 and the second bonding layer 14 are bonding bodies containing non-pressure adhesive components. Therefore, in the manufacturing process of the dimming device 10, the dimming cell 20 does not become high pressure, and the dimming device 10 can be manufactured at normal pressure. As a result, a large amount of pressure is not applied to the surface of the dimming cell 20, and liquid crystal accumulation, a phenomenon in which the liquid crystal of the dimming cell 20 is locally unevenly distributed, can be suppressed. As a result, the quality and appearance of the dimming device 10 can be improved. In contrast, as a comparative example, when a bonding body containing a pressure-adhesive component, such as a PVB interlayer, is interposed between the first glass plate 11 and the second glass plate 12, for example, a large amount of pressure is applied to the surface of the dimming cell 20 through the first glass plate 11 and the second glass plate 12 using an autoclave. If this pressure becomes uneven, there is a risk of liquid crystal accumulation occurring, which is a phenomenon in which the liquid crystals in the dimming cell 20 are locally unevenly distributed.

[0104] Furthermore, according to this embodiment, the first bonding layer 13 and the second bonding layer 14 are made of OCA, which has high heat resistance. As a result, even if the dimming device 10 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the heat-resistant OCA will not soften, and the occurrence of liquid crystal accumulation, a phenomenon in which there is a localized amount of liquid crystal in the dimming cell 20, can be reduced. In addition, when the dimming device 10 is placed vertically on a vertical wall or the like in a high-temperature environment, it is possible to suppress the part of the liquid crystal of the liquid crystal layer 23 from falling vertically downward due to gravity, and to make the amount of liquid crystal in the liquid crystal layer 23 uniform across the surface of the dimming device 10. As a result, the phenomenon of unevenness in the appearance of the dimming device 10 (gravity unevenness) can be suppressed, and the quality and appearance of the dimming device 10 can be improved.

[0105] Furthermore, according to this embodiment, the outer peripheral film 19 is formed so as to surround the dimming cell 20 in a plan view, and the outer peripheral film 19 is located between the first bonding layer 13 and the second bonding layer 14. This prevents moisture and other substances from entering the dimming device 10 from the side, and further enhances the water-impermeable properties of the dimming device 10. In addition, it is possible to suppress the separation of the first bonding layer 13 and the second bonding layer 14 in the thickness direction around the dimming cell 20. Since the outer peripheral film 19 has a uniform thickness, the spacing between the first bonding layer 13 and the second bonding layer 14 on the side of the dimming cell 20 can be made uniform. In particular, the same film substrate as the first substrate 24 and the second substrate 27 of the dimming cell 20 may be used as the outer peripheral film 19. In this case, it is possible to suppress delamination between the outer peripheral film 19 and the first substrate 24 and the second substrate 27 due to differences in physical properties (thermal expansion coefficient, hardness, etc.) between the outer peripheral film 19 and the first substrate 24 and the second substrate 27.

[0106] Furthermore, according to this embodiment, both the first bonding layer 13 and the second bonding layer 14 are made of OCA. In this case, since OCA is made of a film-like layer with high flatness, both sides of the dimming cell 20 located between the first bonding layer 13 and the second bonding layer 14 can be made flat. As a result, the thickness of the dimming cell 20 becomes uniform, and the occurrence of liquid crystal accumulation, a phenomenon in which there is a localized amount of liquid crystal on the dimming cell 20, can be reduced.

[0107] Furthermore, according to this embodiment, both the first bonding layer 13 and the second bonding layer 14 are made of OCA. Since the film thickness of OCA is uniform in plane, it is possible to suppress the pressure distribution on the surface of the dimming cell 20 while suppressing the phenomenon of unevenness occurring in the appearance of the dimming device 10.

[0108] (A modified example of a dimming device) Next, various modifications of the dimming device according to this embodiment will be described with reference to Figures 7 and 8. Figures 7 and 8 show the dimming device 10 according to modifications, respectively. In Figures 7 and 8, the same reference numerals are used for parts that are the same as those shown in Figures 1 to 6, and detailed descriptions are omitted.

[0109] (First modified example of a dimmer) Figure 7 shows a dimming device 10 according to the first modification. As shown in Figure 7, a third bonding layer 47 is positioned between the first glass plate 11 and the first bonding layer 13. The third bonding layer 47 may be composed of, for example, OCR (Optical Clear Resin). OCR is a cured product obtained by curing a liquid curable adhesive layer composition containing a polymerizable compound. Specifically, OCR is obtained by applying a liquid resin, which is a mixture of a base resin such as an acrylic resin, silicone resin, or urethane resin and an additive, to an object and then curing it using, for example, ultraviolet light (UV). In this way, the third bonding layer 47 is interposed between the first glass plate 11 and the first bonding layer 13. This allows the third bonding layer 47 to completely fill the gap between the first glass plate 11 and the first bonding layer 13 when the gap between the first glass plate 11 and the first bonding layer 13 cannot be completely filled by the first bonding layer 13 alone due to the effects of the unevenness of the dimming cell 20.

[0110] (Second variation of the dimmer) Figure 8 shows a dimming device 10 according to a second modified example. As shown in Figure 8, a third bonding layer 47 is placed between the first glass plate 11 and the first bonding layer 13. A film 48 is also placed between the third bonding layer 47 and the first bonding layer 13. The third bonding layer 47 is made of OCR (Optical Clear Resin). As the material of the film 48, any of the materials listed above as materials used for the first substrate 24 and the second substrate 27 may be used, and it is preferable to use a resin film such as polyethylene terephthalate (PET). By interposing the film 48 between the third bonding layer 47 and the first bonding layer 13 in this way, the adhesion between the first bonding layer 13 and the third bonding layer 47 can be improved.

[0111] (Variations of the outer film) Next, various modified examples of the outer perimeter film 19 will be described with reference to Figures 9(a)-(d). Figures 9(a)-(d) are plan views showing various modified examples of the outer perimeter film 19.

[0112] As shown in Figures 9(a)-(d), the outer peripheral film 19 has a shape in which a portion of the shape corresponding to the outer peripheral of the dimming cell 20 (a square shape with the center cut out) has been removed.

[0113] As shown in Figure 9(a), the outer peripheral film 19 may be composed of two L-shaped portions 19a in plan view. Each L-shaped portion 19a extends along two adjacent sides of the dimming cell 20. A gap S is formed on the outer perimeter of the dimming cell 20, between the two L-shaped portions 19a, where the outer peripheral film 19 is not present.

[0114] As shown in Figure 9(b), the outer peripheral film 19 may be composed of four rod-shaped portions 19b in plan view. Each rod-shaped portion 19b extends along one side of the dimming cell 20. Gaps S are formed near the four corners of the dimming cell 20 where the outer peripheral film 19 is not present.

[0115] As shown in Figure 9(c), the outer peripheral film 19 may consist of a portion 19c that is roughly C-shaped in plan view. The roughly C-shaped portion 19c has a shape obtained by removing a portion adjacent to one side of the dimming cell 20 from the rectangular outer peripheral film 19. A gap S is formed in this portion adjacent to one side of the dimming cell 20 where the outer peripheral film 19 is absent.

[0116] As shown in Figure 9(d), the outer peripheral film 19 may be composed of two rod-shaped portions 19d in plan view. The two rod-shaped portions 19d extend parallel to each other along a pair of opposing sides of the dimming cell 20. On the outer peripheral of the dimming cell 20, a gap S is formed where the outer peripheral film 19 is absent on a pair of sides where the two rod-shaped portions 19d are not provided.

[0117] Thus, the outer film 19 has a shape that is a part removed from the shape corresponding to the outer circumference of the dimming cell 20 (a square shape with the center cut out), thereby forming a gap S around the dimming cell 20. As a result, even if the air remaining between the dimming cell 20 and the outer film 19 expands due to thermal expansion when the dimming device 10 is placed in a high-temperature environment, this air can escape through the gap S. This prevents the expanded air from compressing the dimming cell 20 and suppresses deformation of the dimming cell 20.

[0118] (Second Embodiment) Next, a second embodiment will be described with reference to Figures 10 and 11. Figures 10 and 11 show the second embodiment. The second embodiment shown in Figures 10 and 11 differs mainly in that the first bonding layer 13B is made of OCR, while the other components are substantially the same as those of the first embodiment shown in Figures 1 to 9 described above. In Figures 10 and 11, the same reference numerals are used for parts that are the same as those shown in Figures 1 to 9, and detailed descriptions are omitted.

[0119] (Dimming device) As shown in Figure 10, the dimming device 10 according to this embodiment comprises a first glass plate 11, a first bonding layer 13B, a dimming cell 20, a second bonding layer 14, and a second glass plate 12.

[0120] In this embodiment, the first bonding layer 13B is composed of OCR (Optical Clear Resin). OCR is a cured product obtained by curing a liquid curable adhesive layer composition containing a polymerizable compound. Specifically, OCR is obtained by applying a liquid resin, which is a mixture of a base resin such as an acrylic resin, silicone resin, or urethane resin and an additive, to an object and then curing it using, for example, ultraviolet light (UV). The first bonding layer 13B, which is composed of OCR, has optical transparency and preferably also has heat resistance up to at least about 120°C, heat and humidity resistance, and weather resistance. The second bonding layer 14 is composed of OCA (Optical Clear Adhesive).

[0121] (Manufacturing method for dimming devices) Next, the method for manufacturing the dimming device 10 according to this embodiment will be described using Figures 11(a)-(g). Figures 11(a)-(g) are cross-sectional views showing the method for manufacturing the dimming device 10 according to this embodiment.

[0122] First, prepare the second glass plate 12 as shown in Figure 11(a).

[0123] Next, a second bonding layer 14 made of OCA is bonded onto the second glass plate 12 in substantially the same manner as the process shown in Figure 6(b) above (Figure 11(b)).

[0124] Next, the dimming cell 20 is laminated on the second bonding layer 14 in substantially the same manner as the process shown in Figure 6(c) above, and the dimming cell 20 is bonded to the second glass plate 12 by the second bonding layer 14 (Figure 11(c)).

[0125] Next, in substantially the same manner as the process shown in Figure 6(d) above, a frame-shaped outer film 19 is laminated on the second bonding layer 14 around the dimming cell 20, and the outer film 19 is bonded to the second glass plate 12 by the second bonding layer 14 (Figure 11(d)).

[0126] Next, an uncured liquid first bonding material 13C is applied to the dimming cell 20 and the outer film 19 (Figure 11(e)). The first bonding material 13C is an OCR material containing OCR. This OCR is a liquid curable adhesive layer composition containing a polymerizable compound, and may consist of a liquid curable adhesive layer composition obtained by mixing a base resin such as an acrylic resin, silicone resin, or urethane resin with additives. The first bonding material 13C may be applied to the entire or partial area of ​​one side of the dimming cell 20 and the outer film 19, for example, by an application nozzle 55 such as a dispenser or slit coater.

[0127] Next, the first glass plate 11 is prepared and laminated onto the first bonding material 13C, and the first glass plate 11 is bonded to the dimming cell 20 and the outer film 19 using the first bonding material 13C (Figure 11(f)). The first bonding material 13C is OCR and is a bonding body containing a non-pressure adhesive component. Therefore, the first glass plate 11 is bonded to the dimming cell 20 and the outer film 19 without being pressurized (i.e., under ambient pressure (usually atmospheric pressure)). Furthermore, the first glass plate 11 is bonded to the dimming cell 20 and the second glass plate 12 at room temperature (for example, between 10°C and 30°C).

[0128] Subsequently, the first bonding material 13C is cured by irradiating the stacked second glass plate 12, second bonding layer 14, dimming cell 20, first bonding material 13C, and first glass plate 11 with ultraviolet (UV) light (Figure 11(g)). As the first bonding material 13C hardens, the first bonding layer 13B made of OCR is formed. In this way, a dimming device 10 is obtained in which the first glass plate 11, the first bonding layer 13B, the dimming cell 20, the second bonding layer 14, and the second glass plate 12 are stacked on top of each other.

[0129] In this embodiment, a first bonding layer 13B is placed between the first glass plate 11 and the dimming cell 20, and a second bonding layer 14 is placed between the second glass plate 12 and the dimming cell 20. The first bonding layer 13B and the second bonding layer 14 are bonding bodies containing non-pressure adhesive components. As a result, the dimming cell 20 does not become high pressure during the manufacturing process of the dimming device 10, and the dimming device 10 can be manufactured at normal pressure. Therefore, no large pressure is applied to the surface of the dimming cell 20, and liquid crystal accumulation, a phenomenon in which liquid crystal of the dimming cell 20 is locally unevenly distributed, can be suppressed. As a result, the quality and appearance of the dimming device 10 can be improved.

[0130] Furthermore, according to this embodiment, the first bonding layer 13B is made of heat-resistant OCR, and the second bonding layer 14 is made of heat-resistant OCA. As a result, even if the dimming device 10 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the heat-resistant OCA and OCR will not soften, and the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the dimming cell 20, can be reduced. In addition, when the dimming device 10 is placed vertically on a vertical wall or the like in a high-temperature environment, it is possible to suppress the part of the liquid crystal of the liquid crystal layer 23 from falling vertically downward due to gravity, and to make the amount of liquid crystal in the liquid crystal layer 23 uniform across the surface of the dimming device 10. As a result, the phenomenon of unevenness in the appearance of the dimming device 10 (gravity unevenness) can be suppressed, and the quality and appearance of the dimming device 10 can be improved.

[0131] Furthermore, if the thickness distribution of the dimming cell 20 is not uniform, the OCR placed on the surface of the dimming cell 20 may not be able to follow the surface shape of the dimming cell 20. On the other hand, according to this embodiment, since the OCR constituting the first bonding layer 13B is liquid before curing, it can follow the uneven surface shape of the dimming cell 20. Since the second bonding layer 14 is made of OCR, the surface of the dimming cell 20 on the second glass plate 12 side can be horizontal. Therefore, it is possible to suppress the pressure distribution on the surface of the dimming cell 20 while forming a state without gaps (bubbles) between the dimming cell 20 and the first bonding layer 13B or the second bonding layer 14.

[0132] (Third embodiment) Next, a third embodiment will be described with reference to Figures 12 to 17. Figures 12 to 17 show the third embodiment. The third embodiment shown in Figures 12 to 17 differs mainly in that the first bonding layer 13 and the second bonding layer 14 are each composed of OCR, while the other configurations are substantially the same as those of the embodiments shown in Figures 1 to 11 described above. In Figures 12 to 17, the same reference numerals are used for parts that are the same as those in the embodiments shown in Figures 1 to 11, and detailed descriptions are omitted.

[0133] (Dimming device) Figure 12 is a cross-sectional view showing the layer configuration of the dimming device 10 according to this embodiment, and Figure 13 is an exploded perspective view showing the layer configuration of the dimming device 10 according to this embodiment. Note that the dimming device 10 in this embodiment may have a three-dimensional surface shape, but Figures 12 and 13 show the case where the surface shape of the dimming device 10 is planar for ease of understanding.

[0134] As shown in Figure 12, the dimming device 10 comprises a first glass plate 11, a first bonding layer (first OCR layer) 13, a dimming cell 20, a second bonding layer (second OCR layer) 14, and a second glass plate 12. The first glass plate 11, the first bonding layer 13, the dimming cell 20, the second bonding layer 14, and the second glass plate 12 are stacked in this order.

[0135] In this embodiment, the first bonding layer 13 and the second bonding layer 14 are each composed of OCR (Optical Clear Resin). OCR is a cured product obtained by curing a liquid curable adhesive layer composition containing a polymerizable compound. Specifically, OCR is obtained by applying a liquid resin, which is a mixture of a base resin such as an acrylic resin, silicone resin, or urethane resin and an additive, to an object and then curing it using, for example, ultraviolet light (UV). The first bonding layer 13 and the second bonding layer 14 each have optical transparency, and it is preferable that they also have heat resistance up to at least about 120°C, heat and humidity resistance, and weather resistance. However, the OCR constituting the first bonding layer 13 and the second bonding layer 14 do not necessarily have weather resistance. In this case, the dimming device 10 can be made weather-resistant by providing a weather-resistant layer on the dimming device 10. Specifically, a weather-resistant layer (IR-cut layer) may be provided on the opposite sides of the opposing faces of the first glass plate 11 and the second glass plate 12, between the first glass plate 11 and the first bonding layer 13, and / or between the second glass plate 12 and the second bonding layer 14.

[0136] In this embodiment, the first bonding layer 13 directly bonds the first glass plate 11 and the dimming cell 20. The second bonding layer 14 directly bonds the second glass plate 12 and the dimming cell 20. However, the embodiment is not limited to this, and a film such as an ultraviolet (UV) cut film may be interposed between the first glass plate 11 and the first bonding layer 13, between the first bonding layer 13 and the dimming cell 20, between the second bonding layer 14 and the dimming cell 20, and / or between the second glass plate 12 and the second bonding layer 14.

[0137] The resin curing shrinkage rate of the first bonding layer 13 and the second bonding layer 14 may be 2.3% or less, and preferably 2.0% or less. The resin curing shrinkage rate (%) can be calculated as 1 - (specific gravity of liquid resin / specific gravity of cured resin), and the specific gravity can be measured using a hydrometer. By having a resin curing shrinkage rate of 2.3% or less for the first bonding layer 13 and the second bonding layer 14, the impact on the dimming cell 20 due to curing shrinkage of the first bonding layer 13 and the second bonding layer 14 can be reduced. This reduces the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the dimming cell 20.

[0138] It is desirable that the difference between the elastic modulus at high temperature (e.g., 90°C) and the elastic modulus at room temperature (25°C) of the first bonding layer 13 and the second bonding layer 14 is small. Specifically, the elastic modulus of the first bonding layer 13 and the second bonding layer 14 measured at 25°C may be, for example, 0.08 MPa or more and 0.28 MPa or less, preferably 0.15 MPa or more and 0.23 MPa or less. The elastic modulus of the first bonding layer 13 and the second bonding layer 14 measured at 90°C may be, for example, 0.08 MPa or more and 0.28 MPa or less, preferably 0.15 MPa or more and 0.23 MPa or less. The elastic modulus can be measured using, for example, a DMA measuring device (dynamic viscoelasticity measuring device, for example, Rheogel-E4000 manufactured by UBM Co., Ltd.). In this way, the difference between the elastic modulus of the first bonding layer 13 and the second bonding layer 14 at high temperature (e.g., 90°C) and the elastic modulus at room temperature (25°C) is small. This reduces the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the dimming cell 20, even when the dimming device 10 is used in a high-temperature environment such as inside a car.

[0139] The thicknesses of the first bonding layer 13 and the second bonding layer 14 may be appropriately selected depending on the material, etc. Specifically, the thicknesses of the first bonding layer 13 and the second bonding layer 14 may be 30 μm or more and 500 μm or less, and preferably 50 μm or more and 200 μm or less. The size of the first bonding layer 13 and the second bonding layer 14 may be the same as the size of the first glass plate 11 and the second glass plate 12, respectively, or they may be larger than the first glass plate 11 and the second glass plate 12. Furthermore, the first bonding layer 13 and the second bonding layer 14 may be made of the same material or they may be made of different materials.

[0140] As shown in Figures 12 and 13, the first bonding layer 13 is integrated with the OCR layer (third OCR layer) 16. The OCR layer 16 is connected to the second bonding layer 14. The OCR layer 16 is a frame-shaped OCR (Optical Clear Resin) layer in plan view, more specifically having a square shape (a square shape with the center cut out) or a shape with a part of the square shape cut out. The OCR layer 16 is made of the same material as the first bonding layer 13 and is integrally formed with the first bonding layer 13. The OCR layer 16 may also be integrally formed with the second bonding layer 14. By providing the OCR layer 16, it is possible to prevent the side surface of the dimming cell 20 or a part thereof from being exposed to the side surface of the dimming device 10, and to suppress the intrusion of moisture, etc. from the side surface of the dimming device 10, thereby further improving the water-impermeable properties of the dimming device 10.

[0141] The OCR layer 16 is an OCR layer formed in cross-sectional view on the thickness portion of the dimming cell 20 when the first bonding layer 13 and the second bonding layer 14 are larger than the dimming cell 20 (in plan view). The OCR layer 16 is formed to surround the dimming cell 20 in plan view and has a frame-like shape with the shape of the dimming cell 20 cut out from the shapes of the first bonding layer 13 and the second bonding layer 14. In this case, the OCR layer 16 is formed between the first bonding layer 13 and the second bonding layer 14, in the portion corresponding to the periphery of the dimming cell 20.

[0142] The outer circumference of the OCR layer 16 may be the same size as the outer circumference of the first glass plate 11 and the second glass plate 12, or it may be larger than the outer circumference of the first glass plate 11 and the second glass plate 12. The inner circumference of the OCR layer 16 may be the same size as the outer circumference of the dimming cell 20, or it may be larger than the outer circumference of the dimming cell 20. The width Wa of the OCR layer 16 (see Figure 13) is preferably greater than 0 mm and less than or equal to 1 / 4 of the glass width. Alternatively, the OCR layer 16 may be omitted if the side surface or part thereof of the dimming cell 20 is not exposed from the side surface of the dimming device 10.

[0143] The first bonding layer 13, the second bonding layer 14, and the OCR layer 16 are bonded bodies containing non-pressure adhesive components. Here, "bonded bodies containing non-pressure adhesive components" refers to bonded bodies that do not require pressure to properly adhere to adjacent objects, and that can adhere to adjacent objects to a moderate degree under normal pressure.

[0144] In this embodiment, the dimming cell 20 can be the same as in the first embodiment.

[0145] In this embodiment, as described above, a first bonding layer (first OCR layer) 13 is placed between the first glass plate 11 and the dimming cell 20, and a second bonding layer (second OCR layer) 14 is placed between the second glass plate 12 and the dimming cell 20. The first bonding layer 13 bonds the first glass plate 11 and the dimming cell 20 to each other, and the second bonding layer 14 bonds the second glass plate 12 and the dimming cell 20 to each other. As a result, even if the dimming device 10 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the heat-resistant OCR will not soften, and the occurrence of liquid crystal accumulation, a phenomenon in which the liquid crystal of the dimming cell 20 is unevenly distributed, can be suppressed.

[0146] In Figure 13, the external electrode substrate 35 and the electrode protrusion 36 are sandwiched between the OCR layer 16 and the second bonding layer 14, and protrude outward from the OCR layer 16 and the second bonding layer 14. Alternatively, the external electrode substrate 35 and the electrode protrusion 36 may protrude outward only from within the OCR layer 16. In this case, a portion of the external electrode substrate 35 and the electrode protrusion 36 may be embedded in the OCR layer 16.

[0147] (Manufacturing method for dimming devices) Next, the manufacturing method (OCR coating method) of the dimming device 10 according to this embodiment will be explained using Figures 14(a)-(h). Figures 14(a)-(h) are cross-sectional views showing the manufacturing method of the dimming device 10 according to this embodiment.

[0148] First, the dimming cell 20 is manufactured in the same manner as shown in Figures 4(a)-(d) and 5(a)-(c).

[0149] Next, prepare the second glass plate 12 as shown in Figure 14(a).

[0150] Next, an uncured liquid second OCR material 14A is applied to the second glass plate 12 (Figure 14(b)). The second OCR material 14A contains OCR. This OCR is a liquid curable adhesive layer composition containing a polymerizable compound, and may consist of a liquid curable adhesive layer composition obtained by mixing a base resin such as an acrylic resin, silicone resin, or urethane resin with additives. The second OCR material 14A may be applied to the entire or partial area of ​​one side of the second glass plate 12, for example, by an application nozzle 55 such as a dispenser or slit coater.

[0151] Next, the dimming cell 20 described above is laminated onto the second OCR material 14A, and the dimming cell 20 is bonded to the second glass plate 12 by the second OCR material 14A (Figure 14(c)). The second OCR material 14A is a bonding material containing OCR, which is a non-pressure adhesive component, as described above. Therefore, the dimming cell 20 and the second glass plate 12 are bonded without pressure (i.e., under ambient pressure (usually atmospheric pressure)). Furthermore, the second OCR material 14A is bonded to the dimming cell 20 and the second glass plate 12 at room temperature (for example, between 10°C and 30°C).

[0152] Next, the second OCR material 14A is cured by irradiating the stacked second glass plate 12, second OCR material 14A, and dimming cell 20 with ultraviolet (UV) light. The curing of the second OCR material 14A forms the second bonding layer 14. This results in a laminate 30 in which the second glass plate 12, the second bonding layer 14, and the dimming cell 20 are stacked on top of each other (Figure 14(d)).

[0153] Next, prepare the first glass plate 11 (Figure 14(e)).

[0154] Next, an uncured liquid first OCR material 13A is applied to the first glass plate 11 (Figure 14(f)). The first OCR material 13A contains OCR. This OCR may be the same material as the second OCR material 14A, or it may be a different material from the second OCR material 14A. The first OCR material 13A may be applied to the entire or partial area of ​​one side of the first glass plate 11 by an application nozzle 55, for example, a dispenser or a slit coater.

[0155] Next, the laminate 30 described above is laminated onto the first OCR material 13A (Figure 14(g)). At this time, the first OCR material 13A is positioned so that it faces the dimming cell 20 side of the laminate 30. This allows the first glass plate 11 to be bonded to the dimming cell 20 of the laminate 30 using the first OCR material 13A. As described above, the first OCR material 13A is a bonding material containing OCR, which is a non-pressure adhesive component. Therefore, the dimming cell 20 of the laminate 30 and the first glass plate 11 are bonded without pressure (i.e., under ambient pressure (usually atmospheric pressure)). Furthermore, the first OCR material 13A is bonded to the dimming cell 20 and the first glass plate 11 at room temperature (for example, between 10°C and 30°C). At this time, a portion of the first OCR material 13A is on the second glass plate 12 of the laminate 30 and wraps around the dimming cell 20.

[0156] Next, the first OCR material 13A is cured by irradiating the stacked second glass plate 12, second bonding layer 14, dimming cell 20, first OCR material 13A, and first glass plate 11 with ultraviolet (UV) light. The first bonding layer 13 is formed when the first OCR material 13A hardens. In addition, an OCR layer 16 is formed by the portion of the first OCR material 13A that wraps around the dimming cell 20. In this way, a dimming device 10 is obtained in which the first glass plate 11, first bonding layer 13, dimming cell 20, second bonding layer 14, and second glass plate 12 are stacked on top of each other (Figure 14(h)).

[0157] As described above, according to this embodiment, a first bonding layer (first OCR layer) 13 is placed between the first glass plate 11 and the dimming cell 20, and a second bonding layer (second OCR layer) 14 is placed between the second glass plate 12 and the dimming cell 20. The OCR constituting the first bonding layer 13 and the second bonding layer 14 is a bonding body containing a non-pressure adhesive component. As a result, the dimming cell 20 does not become high pressure during the manufacturing process of the dimming device 10, and the dimming device 10 can be manufactured at normal pressure. Therefore, no large pressure is applied to the surface of the dimming cell 20, and liquid crystal accumulation, a phenomenon in which the liquid crystal of the dimming cell 20 is locally unevenly distributed, can be suppressed. As a result, the quality and appearance of the dimming device 10 can be improved. In contrast, as a comparative example, when a bonding body containing a pressure-adhesive component, such as a PVB interlayer, is interposed between the first glass plate 11 and the second glass plate 12, for example, a large pressure is applied to the surface of the dimming cell 20 through the first glass plate 11 and the second glass plate 12 using an autoclave. If this pressure is uneven, there is a risk of liquid crystal accumulation occurring, which is a phenomenon in which the liquid crystal of the dimming cell 20 is locally unevenly distributed.

[0158] Furthermore, according to this embodiment, the first bonding layer 13 and the second bonding layer 14 are made of highly heat-resistant OCR. As a result, even if the dimming device 10 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the highly heat-resistant OCR will not soften, and the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the dimming cell 20, can be reduced. In addition, when the dimming device 10 is placed vertically on a vertical wall or the like in a high-temperature environment, it is possible to suppress the part of the liquid crystal of the liquid crystal layer 23 from falling vertically downward due to gravity, and to make the amount of liquid crystal in the liquid crystal layer 23 uniform across the surface of the dimming device 10. As a result, the phenomenon of unevenness in the appearance of the dimming device 10 (gravity unevenness) can be suppressed, and the quality and appearance of the dimming device 10 can be improved.

[0159] Furthermore, according to this embodiment, a frame-shaped OCR layer 16 is formed so as to surround the dimming cell 20 in a plan view, and the OCR layer 16 is located between the first bonding layer 13 and the second bonding layer 14. This prevents moisture and other substances from entering the dimming device 10 from the sides, and further enhances the water-impermeable properties of the dimming device 10.

[0160] (First modified example of the manufacturing method of a dimming device) Next, a first modified example of the method for manufacturing the dimming device 10 according to this embodiment will be described using Figures 15(a)-(h). Figures 15(a)-(h) are cross-sectional views showing the first modified example of the method for manufacturing the dimming device 10.

[0161] First, prepare the second glass plate 12 as shown in Figure 15(a).

[0162] Next, in substantially the same manner as the process shown in Figure 14(b) above, the uncured liquid second OCR material 14A is applied onto the second glass plate 12 using a coating nozzle 55, such as a dispenser or slit coater (Figure 15(b)).

[0163] Next, the second OCR material 14A is partially cured by irradiating the stacked second glass plate 12 and second OCR material 14A with ultraviolet (UV) light (Figure 15(c)). Partial curing refers to a state in which the OCR is not completely cured, but the adhesiveness of the OCR is maintained to a certain extent. The amount of ultraviolet (UV) light irradiated at this time may be, for example, 50% to 80% of the amount used when the second OCR material 14A is completely cured (for example, the process shown in Figure 14(d) above). At this time, it is preferable to provide a flat jig 56 on the side of the second OCR material 14A and flatten the surface of the second OCR material 14A that faces the opposite side of the second glass plate 12.

[0164] Next, the dimming cell 20 described above is laminated onto the partially cured second OCR material 14A, and the dimming cell 20 is bonded to the second glass plate 12 using the partially cured second OCR material 14A (Figure 15(d)). This results in a laminate 30 in which the second glass plate 12, the second OCR material 14A, and the dimming cell 20 are laminated to each other.

[0165] Next, prepare the first glass plate 11 (Figure 15(e)).

[0166] Next, in substantially the same manner as the process shown in Figure 14(f) above, the uncured liquid first OCR material 13A is applied onto the first glass plate 11 using a coating nozzle 55, such as a dispenser or slit coater (Figure 15(f)).

[0167] Next, the laminate 30 described above is laminated onto the first OCR material 13A in substantially the same manner as the process shown in Figure 14(g) above (Figure 15(g)). At this time, the first OCR material 13A is positioned so that it faces the dimming cell 20 side of the laminate 30. In this way, the first glass plate 11 is bonded to the dimming cell 20 of the laminate 30 using the first OCR material 13A.

[0168] Subsequently, in substantially the same manner as the process shown in Figure 14(h) above, the first OCR material 13A is cured by irradiating the stacked second glass plate 12, second OCR material 14A, dimming cell 20, first OCR material 13A, and first glass plate 11 with ultraviolet (UV) light. The first bonding layer 13 is formed when the first OCR material 13A hardens. The second bonding layer 14 is formed when the partially hardened second OCR material 14A hardens completely. At this time, the portion of the first OCR material 13A that wraps around the dimming cell 20 forms the OCR layer 16. In this way, a dimming device 10 is obtained in which the first glass plate 11, the first bonding layer 13, the dimming cell 20, the second bonding layer 14, and the second glass plate 12 are stacked on top of each other (Figure 15(h)).

[0169] According to this modified example, after applying the second OCR material 14A onto the second glass plate 12, the second OCR material 14A is pre-cured before bonding the dimming cell 20. Then, the dimming cell 20 is bonded to the second glass plate 12 using the pre-cured second OCR material 14A. In this case, when the second OCR material 14A pre-cures, the surface irregularities of the dimming cell 20 are not transferred to the second bonding layer 14. This improves the flatness of the second bonding layer 14 and makes the interface between the dimming cell 20 and the second bonding layer 14 (the second interface S2 shown in Figure 16) flatter.

[0170] Figure 16 shows a dimming device 10 manufactured by the manufacturing method of the dimming device 10 according to this modified example. In the dimming device 10 shown in Figure 16, a first interface S1 is formed between the first bonding layer 13 and the dimming cell 20, and a second interface S2 is formed between the second bonding layer 14 and the dimming cell 20. In this case, the second interface S2 is flatter than the first interface S1. The other configurations are the same as those of the dimming device 10 described above.

[0171] Furthermore, according to this modified version, when the second OCR material 14A is pre-cured, the second OCR material 14A does not come into contact with the dimming cell 20, thus reducing the impact on the dimming cell 20 due to the curing shrinkage of the second OCR material 14A. This suppresses liquid crystal accumulation, a phenomenon in which liquid crystals in the dimming cell 20 are locally unevenly distributed, thereby improving the quality and appearance of the dimming device 10.

[0172] (Second modified example of the method for manufacturing a dimming device) Next, a second modified example of the method for manufacturing the dimming device 10 according to this embodiment will be described using Figures 17(a)-(i). Figure 17(a)-(i) is a cross-sectional view showing the second modified example of the method for manufacturing the dimming device 10.

[0173] First, prepare the second glass plate 12 as shown in Figure 17(a).

[0174] Next, in substantially the same manner as the process shown in Figure 14(b) above, the uncured liquid second OCR material 14A is applied onto the second glass plate 12 using a coating nozzle 55, such as a dispenser or slit coater (Figure 17(b)).

[0175] Next, a transparent protective film 57 is laminated onto the second OCR material 14A, and the protective film 57 is bonded to the second glass plate 12 by the second OCR material 14A (Figure 17(c)). At this time, the bonding of the protective film 57 is performed on a flat jig 56. As the protective film 57, a separator film such as a silicone-based release film or a non-silicone-based (fluorine-based, etc.) release film can be used. By laminating the protective film 57 onto the second OCR material 14A in this way, the transportability of the second glass plate 12 and the second OCR material 14A can be improved.

[0176] Next, the second OCR material 14A is partially cured by irradiating the stacked second glass plate 12, second OCR material 14A, and protective film 57 with ultraviolet light (UV) (Figure 17(d)). At this time, it is preferable to provide a flat jig 56 at least on the protective film 57 side and flatten the surface of the second OCR material 14A that faces the opposite side of the second glass plate 12.

[0177] Next, the protective film 57 is peeled off, and the dimming cell 20 described above is laminated onto the pre-cured second OCR material 14A, and the dimming cell 20 is bonded to the second glass plate 12 using the pre-cured second OCR material 14A (Figure 17(e)). This yields a laminate 30 in which the second glass plate 12, the second OCR material 14A, and the dimming cell 20 are laminated to each other. The dimming cell 20 may also be bonded to the second glass plate 12 by a roller bonding method using a roller. Alternatively, the dimming cell 20 may be bonded to the second glass plate 12 by a roller vacuum bonding method or a vacuum bonding method.

[0178] Next, prepare the first glass plate 11 (Figure 17(f)).

[0179] Next, in substantially the same manner as the process shown in Figure 14(f) above, the uncured liquid first OCR material 13A is applied onto the first glass plate 11 using a coating nozzle 55, such as a dispenser or slit coater (Figure 17(g)).

[0180] Next, in substantially the same manner as the process shown in Figure 14(g) above, the laminate 30 described above is laminated onto the first OCR material 13A, and the first glass plate 11 is bonded to the dimming cell 20 of the laminate 30 using the first OCR material 13A (Figure 17(h)).

[0181] Subsequently, in substantially the same manner as the process shown in Figure 14(h) above, ultraviolet (UV) light is irradiated onto the stacked second glass plate 12, second OCR material 14A, dimming cell 20, first OCR material 13A, and first glass plate 11. This hardens the first OCR material 13A, forming the first bonding layer 13. In addition, the second bonding layer 14 is formed by completely hardening the partially hardened second OCR material 14A. In this way, a dimming device 10 is obtained in which the second glass plate 12, first bonding layer 13, dimming cell 20, and second bonding layer 14 are stacked on top of each other (Figure 17(i)).

[0182] According to this modified example, the second OCR material 14A is applied to the second glass plate 12, a protective film 57 is bonded to the second OCR material 14A, and then the second OCR material 14A is pre-cured before bonding the dimming cell 20. After that, the protective film 57 is peeled off, and the dimming cell 20 is bonded to the second glass plate 12 using the pre-cured second OCR material 14A. In this case, when the second OCR material 14A is pre-cured, the flat surface shape of the protective film 57 is transferred to the second bonding layer 14, and the surface irregularities of the dimming cell 20 are not transferred to the second bonding layer 14. This improves the flatness of the second bonding layer 14 and makes the second interface S2 between the dimming cell 20 and the second bonding layer 14 flatter. In the manufacturing method of the dimming device 10 according to this modified example, a dimming device 10 (see Figure 16) can be obtained in which the second interface S2 between the second bonding layer 14 and the dimming cell 20 is flatter than the first interface S1 between the first bonding layer 13 and the dimming cell 20.

[0183] Furthermore, according to this modified example, when the second OCR material 14A is pre-cured, the second OCR material 14A does not come into contact with the dimming cell 20, thus reducing the impact on the dimming cell 20 due to the curing shrinkage of the second OCR material 14A. As a result, liquid crystal accumulation, a phenomenon in which liquid crystals in the dimming cell 20 are locally unevenly distributed, can be suppressed, thereby improving the quality and appearance of the dimming device 10.

[0184] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Figures 18 to 28. Figures 18 to 28 are diagrams showing the fourth embodiment.

[0185] Figure 18 is an exploded perspective view showing the configuration of the liquid crystal device 101 of this embodiment. Note that all figures shown below, including Figure 18, are schematic representations, and the size and shape of each part are exaggerated as appropriate for ease of understanding.

[0186] Furthermore, the following explanation will include specific numerical values, shapes, materials, etc., but these may be changed as appropriate. In this specification, terms that specify shapes and geometric conditions, such as parallel and orthogonal, are used not only in their strict sense but also to include states that perform similar optical functions and have an error that can be considered parallel or orthogonal. In this specification, terms such as plate, sheet, and film are used, but in general usage, they are used in the order of plate, sheet, and film in order of increasing thickness, and this specification follows that convention. However, there is no technical significance to this distinction, so these terms may be replaced as appropriate. In this specification, the sheet surface refers to the surface of each sheet that is in the planar direction when viewed as a whole sheet. The same applies to the plate surface and film surface. Planar view refers to the view from a direction perpendicular to the main surface of the dimming device. In this disclosure, transparent means that it transmits light of at least the wavelength to be used. For example, even if a material does not transmit visible light, if it transmits infrared light, it shall be treated as transparent when used for infrared applications. Furthermore, the specific numerical values ​​specified in this specification and the claims should be treated as including a general margin of error. That is, a difference of approximately ±10% is substantially negligible, and values ​​set slightly outside the specified range should be interpreted as substantially within the scope of this invention.

[0187] The liquid crystal device 101 can be applied to various technological fields where adjustment of light transmittance is required, and its scope of application is not particularly limited. The liquid crystal device 101 can be placed, for example, in areas where light control is required, such as window panes of buildings, showcases, transparent partitions indoors, vehicle windows (e.g., front, side, rear, roof windows, etc.), and partition boards inside vehicles. This makes it possible to control the amount of light incident on the inside of buildings and vehicles, or to control the amount of light incident on a predetermined area inside buildings and vehicles.

[0188] The liquid crystal device 101 according to this embodiment may be configured as a three-dimensional shape with a curved surface shape, for example, the liquid crystal device 101 may have a shape that is convex on one side. However, the liquid crystal device 101 is not limited to this, and for example, its surface shape may be planar (i.e., flat). In the following figures, including Figure 18, the surface shape is shown as planar for simplicity.

[0189] As shown in Figure 18, the liquid crystal device (laminated glass) 101 according to this embodiment comprises a first glass plate 141, a first bonding layer 131, a liquid crystal cell 110, a second bonding layer 132, and a second glass plate 142. The first glass plate 141, the first bonding layer 131, the liquid crystal cell 110, the second bonding layer 132, and the second glass plate 142 are stacked in this order. A third bonding layer 133 is also arranged on the outer periphery of the liquid crystal cell 110.

[0190] Figure 19 is a cross-sectional view showing the layer configuration of the liquid crystal device 101 according to this embodiment. As shown in Figure 19, the liquid crystal device 101 comprises a first glass plate 141, a second glass plate 142, and a liquid crystal cell 110 disposed between the first glass plate 141 and the second glass plate 142. The liquid crystal cell 110 comprises a first laminate 112 including a first substrate 121A, a first transparent electrode 122A, and a first alignment layer 123A, a second laminate 113 including a second substrate 121B, a second transparent electrode 122B, and a second alignment layer 123B, and a liquid crystal layer 114 disposed between the first laminate 112 and the second laminate 113.

[0191] The first glass plate (first transparent substrate) 141 and the second glass plate (second transparent substrate) 142 are glass plates with high light transmittance, respectively, and are arranged on the front and back surfaces of the liquid crystal device 101. In this embodiment, the first glass plate 141 and the second glass plate 142 have a thickness of 0.5 mm or more and 4 mm or less, and as an example, glass plates with a thickness of 2 mm are used for both. When inorganic glass is used as the first glass plate 141 and the second glass plate 142, a liquid crystal device 101 with excellent heat resistance and scratch resistance can be made. The first glass plate 141 and the second glass plate 142 may be subjected to surface treatment such as a hard coat as necessary. In addition, transparent resin plates (so-called resin glass) may be used instead of inorganic glass for the first glass plate (first transparent substrate) 141 and the second glass plate (second transparent substrate) 142. Examples of transparent resin plates that can be used as the first transparent substrate and the second transparent substrate include polycarbonate and acrylic. When transparent resin plates are used for the first and second transparent substrates, the liquid crystal device 101 can be made lighter.

[0192] The first bonding layer 131 is positioned between the first glass plate 141 and the liquid crystal cell 110, and is a component that bonds the first glass plate 141 and the liquid crystal cell 110 together. The first bonding layer 131 is larger in plan view than the liquid crystal cell 110. In this embodiment, the first bonding layer 131 is composed of OCR (Optical Clear Resin). OCR is a cured product obtained by curing a liquid curable adhesive layer composition containing a polymerizable compound. Specifically, OCR is obtained by applying a liquid resin, which is a mixture of a base resin such as an acrylic resin, a silicone resin, or a urethane resin, and additives, to an object, and then curing it using, for example, ultraviolet light (UV). The first bonding layer 131 has optical transparency, and it is preferable that it also has heat resistance up to at least about 120°C, humid heat resistance, and weather resistance.

[0193] The resin curing shrinkage rate of the first bonding layer 131 may be 2.3% or less, and preferably 2.0% or less. The resin curing shrinkage rate (%) can be calculated as 1 - (specific gravity of liquid resin / specific gravity of cured resin), and the specific gravity can be measured using a hydrometer. By setting the resin curing shrinkage rate of the first bonding layer 131 to 2.3% or less, the impact on the liquid crystal cell 110 due to the curing shrinkage of the first bonding layer 131 can be reduced. This reduces the occurrence of liquid crystal accumulation, a phenomenon in which there is a localized abundance of liquid crystal in the liquid crystal cell 110.

[0194] It is desirable that the first bonding layer 131 has a small difference between its elastic modulus at high temperatures (e.g., 90°C) and its elastic modulus at room temperature (25°C). Specifically, the elastic modulus of the first bonding layer 131 measured at 25°C may be, for example, 0.08 MPa or more and 0.28 MPa or less, preferably 0.15 MPa or more and 0.23 MPa or less. The elastic modulus of the first bonding layer 131 measured at 90°C may be, for example, 0.08 MPa or more and 0.28 MPa or less, preferably 0.15 MPa or more and 0.23 MPa or less. The elastic modulus can be measured using, for example, a DMA measuring device (dynamic viscoelasticity measuring device, for example, Rheogel-E4000 manufactured by UBM Co., Ltd.). In this way, the difference between the elastic modulus of the first bonding layer 131 at high temperatures (e.g., 90°C) and its elastic modulus at room temperature (25°C) is small. This makes it possible to reduce the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the liquid crystal cell 110, even when the liquid crystal device 101 is used in a high-temperature environment such as inside a car.

[0195] Here, the region that overlaps with one end of the liquid crystal cell in a plan view is called the first end-side region 131b, and the region adjacent to the first end-side region 131b and extending to the other side opposite to the first side is called the inner region 131a (see Figure 26). In the usage state in which the main surface of the liquid crystal device 101 is positioned along the direction of gravity (hereinafter also referred to as vertical positioning), it is desirable to orient the liquid crystal device 101 so that the first end-side region 131b is on the lower side in the vertical direction. Therefore, in the usage state in which the liquid crystal device 101 is positioned vertically, the "one side" is the "lower side in the vertical direction," and the "other side" is the "upper side in the vertical direction."

[0196] In this embodiment, in the area overlapping with the liquid crystal cell 110, the first end-side region 131b has a thicker layer than the inner region 131a. That is, in the area overlapping with the liquid crystal cell 110, the first bonding layer 131 has a thicker portion and a thinner portion (hereinafter also referred to as the layer thickness difference). By providing the above-mentioned layer thickness difference in the thickness of the first bonding layer 131, the strength of the first bonding layer 131 in the first end-side region 131b is increased, and the ability to maintain the shape of the liquid crystal cell 110 is enhanced. Therefore, for example, even when the liquid crystal device 101 is used in a high-temperature environment such as inside a car, the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the liquid crystal cell 110 near the first end-side region 131b, can be reduced. The preferred numerical range for the layer thickness difference of the first bonding layer 131 will be described later. In this embodiment, as shown in Figure 26, the thickness of the rectangular area located on the lower side of the first end-side region 131b is thicker than that of the inner rectangular area 131a.

[0197] The maximum thickness of the first bonding layer 131 may be appropriately selected depending on the material, etc. Specifically, the maximum thickness of the first bonding layer 131 may be 30 μm or more and 1,000 μm or less. Also, the size of the first bonding layer 131 may be the same as the first glass plate 141 and the second glass plate 142, or it may be larger than or equal to the size of the liquid crystal cell 110 and smaller than the first glass plate 141 and the second glass plate 142.

[0198] The second bonding layer 132 is positioned between the second glass plate 142 and the liquid crystal cell 110, and is a component that bonds the second glass plate 142 and the liquid crystal cell 110 together. The second bonding layer 132 is larger in plan view than the liquid crystal cell 110. In this embodiment, the second bonding layer 132 is made of OCA (Optical Clear Adhesive). The OCA is a layer made, for example, as follows: First, a liquid curable adhesive layer composition containing a polymerizable compound is applied to a release film such as polyethylene terephthalate (PET), and this is cured using, for example, ultraviolet light (UV) to obtain an OCA sheet. The above curable adhesive layer composition may be an optical adhesive such as an acrylic resin, a silicone resin, or a urethane resin. After bonding this OCA sheet to an object, the release film is peeled off to obtain a layer made of the above OCA. The second bonding layer 132, made of OCA, preferably has optical transparency and further possesses heat resistance up to at least 120°C, as well as resistance to humid heat and weathering.

[0199] The thickness of the second bonding layer 132 may be appropriately selected depending on its material and other factors. Specifically, the thickness of the second bonding layer 132 may be 30 μm or more and 500 μm or less, and preferably 50 μm or more and 200 μm or less. The size of the second bonding layer 132 may be the same as the first glass plate 141 and the second glass plate 142, or it may be larger than or equal to the size of the liquid crystal cell 110 and smaller than the first glass plate 141 and the second glass plate 142.

[0200] In this embodiment, the first bonding layer 131 directly bonds the first glass plate 141 and the liquid crystal cell 110. The second bonding layer 132 directly bonds the second glass plate 142 and the liquid crystal cell 110. However, the invention is not limited to these, and a film such as an ultraviolet (UV) cut film may be interposed between the first glass plate 141 and the first bonding layer 131, between the first bonding layer 131 and the liquid crystal cell 110, between the second bonding layer 132 and the liquid crystal cell 110, and / or between the second glass plate 142 and the second bonding layer 132.

[0201] The third bonding layer 133 is a layer formed in cross-sectional view at the thickness of the liquid crystal cell 110 when the first bonding layer 131 and the second bonding layer 132 are each larger than the liquid crystal cell 110 in plan view. As shown in Figure 19, the third bonding layer 133 is located between the first bonding layer 131 and the second bonding layer 132, and is positioned in the area corresponding to the periphery of the liquid crystal cell 110. The third bonding layer 133 is also bonded to the first bonding layer 131 and the second bonding layer 132. In plan view, the third bonding layer 133 has a frame shape, and more specifically, a rectangular shape with the center cut out. In this embodiment, the third bonding layer 133 is made of the same material as the first bonding layer 131, i.e., OCR, and is integrally formed with the first bonding layer 131. The third bonding layer 133 may also have a shape in which a part of the frame shape is cut in plan view, and may be integrally formed with the second bonding layer 132 instead of the first bonding layer. By providing the third bonding layer 133, it is possible to prevent the side surface or part thereof of the liquid crystal cell 110 from being exposed to the side surface of the liquid crystal device 101, and to suppress the intrusion of moisture and other substances from the side surface of the liquid crystal device 101, thereby further improving the water-impermeable properties of the liquid crystal device 101.

[0202] The outer circumference of the third bonding layer 133 may coincide with the outer circumferences of the first glass plate 141 and the second glass plate 142, or it may be located outside the outer circumferences of the first glass plate 141 and the second glass plate 142. Furthermore, it is preferable that the inner circumference of the third bonding layer 133 coincides with the outer circumference of the liquid crystal cell 110. The width Wa of the third bonding layer 133 (see Figure 19) is preferably greater than 0 mm and less than or equal to 1 / 4 of the glass width. Alternatively, the third bonding layer 133 may be omitted if the side surface or part thereof of the liquid crystal cell 110 is not exposed from the side surface of the liquid crystal device 101.

[0203] The first bonding layer 131, the second bonding layer 132, and the third bonding layer 133 are bonded bodies containing non-compressive adhesive components. Here, "bonded bodies containing non-compressive adhesive components" refers to bonded bodies that do not require pressurization to properly adhere to adjacent objects, and that can adhere to adjacent objects to a moderate degree under normal pressure.

[0204] In the embodiment of this disclosure, the liquid crystal cell 110 (dimmable film, liquid crystal film) is a film that can control the amount of transmitted light by changing the applied voltage. The liquid crystal cell 110 is arranged so as to be sandwiched between a first glass plate 141 and a second glass plate 142. This liquid crystal cell 110 has a guest-host type liquid crystal layer using a dichroic dye and is a component that changes the amount of transmitted light by an electric field applied to the liquid crystal. The liquid crystal cell 110 comprises a film-like first laminate 112, a film-like second laminate 113, and a liquid crystal layer 114 disposed between the first laminate 112 and the second laminate 113.

[0205] As shown in Figure 19, the first laminate 112 is formed by laminating a first substrate 121A, a first transparent electrode 122A, and a first orientation layer 123A. That is, from the first bonding layer 131 side, the first substrate 121A, the first transparent electrode 122A, and the first orientation layer 123A are stacked in this order. The second laminate 113 is formed by laminating a second substrate 121B, a second transparent electrode 122B, and a second orientation layer 123B. That is, from the second bonding layer 132 side, the second substrate 121B, the second transparent electrode 122B, and the second orientation layer 123B are stacked in this order.

[0206] Furthermore, a plurality of bead spacers 124 are arranged between the first laminate 112 and the second laminate 113. The liquid crystal layer 114 is arranged between the first laminate 112 and the second laminate 113 by filling the spaces between the plurality of bead spacers 124 with liquid crystal. The plurality of bead spacers 124 may be arranged irregularly or regularly.

[0207] The liquid crystal cell 110 changes the orientation of the liquid crystal material of the guest host liquid crystal composition in the liquid crystal layer 114 by driving the first transparent electrode 122A and the second transparent electrode 122B provided in the first laminate 112 and the second laminate 113, thereby changing the amount of transmitted light.

[0208] The first substrate 121A and the second substrate 121B are made of transparent resin and can be fitted with a flexible film. It is desirable that the first substrate 121A and the second substrate 121B be transparent resin films with low optical anisotropy and a transmittance of 80% or more in the visible wavelength range (380 nm to 800 nm). Examples of materials for the transparent resin film include acetylcellulose resins such as triacetylcellulose (TAC), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene (PE), polypropylene (PP), polystyrene, polymethylpentene, and EVA, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, acrylic resins, polyurethane resins, polysulfone (PSF), polyethersulfone (PES), polycarbonate (PC), polyether (PE), polyetherketone (PEK), (meth)acronitrile, cycloolefin polymer (COP), and cycloolefin copolymer. As the material for the transparent resin film, resins such as polycarbonate, cycloolefin polymer, and polyethylene terephthalate are particularly preferred. The thickness of the transparent resin film used as the first base material 121A and the second base material 121B can be appropriately selected within the range in which the transparent resin film is flexible, although this depends on the material. The thickness of the first base material 121A and the second base material 121B may be 50 μm or more and 200 μm or less, respectively. In this embodiment, as an example of the first base material 121A and the second base material 121B, a polyethylene terephthalate film with a thickness of 125 μm is used.

[0209] The first transparent electrode 122A and the second transparent electrode 122B are composed of transparent conductive films laminated on the first substrate 121A and the second substrate 121B (transparent resin film), respectively. Various transparent electrode materials applicable to this type of transparent resin film can be used as the transparent conductive film, including transparent metal thin films with an oxide-based total light transmittance of 50% or more. Examples include tin oxide-based, indium oxide-based, and zinc oxide-based films.

[0210] Examples of tin oxide (SnO2)-based materials include NESA (tin oxide SnO2), ATO (Antimony Tin Oxide: antimond-doped tin oxide), and fluorine-doped tin oxide. Examples of indium oxide (In2O3)-based materials include indium oxide, ITO (Indium Tin Oxide: indium tin oxide), and IZO (Indium Zinc Oxide). Examples of zinc oxide (ZnO)-based materials include zinc oxide, AZO (aluminum-doped zinc oxide), and gallium-doped zinc oxide. In this embodiment, the transparent conductive films constituting the first transparent electrode 122A and the second transparent electrode 122B are formed of ITO.

[0211] The bead spacer 124 is a component that defines the thickness (cell gap) of the liquid crystal layer 114. In this embodiment, a spherical bead spacer is used as the bead spacer 124. The diameter of the bead spacer 124 may be in the range of 1 μm to 20 μm, preferably 3 μm to 15 μm. The bead spacer 124 can be made of a wide range of materials, including inorganic materials such as silica, organic materials, or a core-shell structure combining these. In addition to a spherical shape, the bead spacer may also be made of rod shapes such as cylindrical, elliptical, or polygonal prism shapes. The bead spacer 124 is manufactured from a transparent material, but the color may be adjusted by applying a colored material as needed.

[0212] In this embodiment, the bead spacer 124 is provided on the second laminate 113, but it is not limited to this, and may be provided on both the first laminate 112 and the second laminate 113, or only on the first laminate 112. Also, the bead spacer 124 is not necessarily required. Furthermore, a columnar spacer may be used instead of the bead spacer 124, or together with the bead spacer 124.

[0213] The first orientation layer 123A and the second orientation layer 123B are components for aligning the liquid crystal molecules contained in the liquid crystal layer 114 in a desired direction. The first orientation layer 123A and the second orientation layer 123B are formed by photo-alignment layers. The photo-alignment material applicable to the photo-alignment layer can be a wide variety of materials to which photo-alignment methods can be applied, such as photodegradable, photodimerizable, and photoisomerizable materials. In this embodiment, a photodimerizable material is used. Examples of photodimerizable materials include polymers having cinnamate, coumarin, benzylidenephthalimidine, benzylideneacetophenone, diphenylacetylene, stilbazole, uracil, quinolinone, maleimide, or cinnamyridene acetate derivatives. Among these, polymers having cinnamate, coumarin, or both are preferred because they have good orientation-regulating power.

[0214] In addition, a rubbing alignment layer may be used instead of the photo-alignment layer. With respect to the rubbing alignment layer, the rubbing process may be omitted, or the rubbing process may be performed to create a fine line-like uneven shape and produce the alignment layer. In this embodiment, the liquid crystal cell 110 is provided with a first alignment layer 123A and a second alignment layer 123B, but it is not limited to this, and a configuration without the first alignment layer 123A and the second alignment layer 123B is also possible.

[0215] The liquid crystal layer 114 can be broadly composed of a guest-host liquid crystal composition or a dichroic dye composition. The guest-host liquid crystal composition may contain a chiral agent so that when the liquid crystal material is horizontally oriented, it is oriented in a spiral shape in the thickness direction of the liquid crystal layer 114. In addition, a sealing material 125, which is annular or frame-shaped in plan view, is arranged between the first laminate 112 and the second laminate 113 so as to surround the liquid crystal layer 114. This sealing material 125 holds the first laminate 112 and the second laminate 113 together and prevents leakage of the liquid crystal material. The sealing material 125 can be a thermosetting resin such as epoxy resin or acrylic resin, or an ultraviolet curing resin.

[0216] For the liquid crystal layer 114, nematic liquid crystal compounds, smectic liquid crystal compounds, and cholesteric liquid crystal compounds can be applied as liquid crystal compounds that do not have polymerizable functional groups. Examples of nematic liquid crystal compounds include biphenyl compounds, terphenyl compounds, phenylcyclohexyl compounds, biphenylcyclohexyl compounds, phenylbicyclohexyl compounds, trifluoro compounds, phenyl benzoate compounds, phenyl cyclohexylbenzoate compounds, phenyl phenyl benzoate compounds, phenyl bicyclohexylcarboxylic acid compounds, azomethine compounds, azo compounds, and azooxy compounds, stilbene compounds, tran compounds, ester compounds, bicyclohexyl compounds, phenylpyrimidine compounds, biphenylpyrimidine compounds, pyrimidine compounds, and biphenylethine compounds.

[0217] Examples of smectic liquid crystal compounds include ferroelectric polymer liquid crystal compounds such as polyacrylates, polymethacrylates, polychloroacrylates, polyoxylanes, polysiloxanes, and polyesters. Examples of cholesteric liquid crystal compounds include cholesteryl linoleates, cholesteryl oleates, cellulose, cellulose derivatives, and polypeptides.

[0218] Examples of dichroic dyes used in the guest-host method include dyes that are soluble in liquid crystals and exhibit high dichroism, such as azo, anthraquinone, quinophthalone, perylene, indigo, thioindigo, merocyanine, styryl, azomethine, and tetrazine dichroic dyes.

[0219] The liquid crystal cell 110 is configured as normally dark, with the first alignment layer 123A and the second alignment layer 123B being horizontal alignment layers with a pre-tilt alignment restricting force set in a certain direction, so that the orientation of the guest host liquid crystal composition when light is blocked is formed when there is no electric field. Alternatively, the setting for light blocking of the liquid crystal cell 110 may be configured as normally clear when an electric field is applied. Here, normally dark is a structure in which the transmittance is minimum when no voltage is applied to the liquid crystal, resulting in a black screen. Normally clear is a structure in which the transmittance is maximum when no voltage is applied to the liquid crystal, resulting in a transparent screen.

[0220] Furthermore, since it is desirable that the scenery visible through the liquid crystal cell 110 is clearly visible when light is transmitted, a low haze value during light transmission is desirable. Specifically, the haze value of the liquid crystal cell 110 during light transmission is desirable to be 30% or less, and more preferably 15% or less. In order to achieve such a low haze value, it is desirable that the liquid crystal mixture does not contain polymerizable compounds.

[0221] The liquid crystal cell 110 in this embodiment is shown as having a guest-host type liquid crystal layer 114, but is not limited to this. The liquid crystal cell 110 may also be configured to have a liquid crystal layer 114 that does not use a dichroic dye composition, such as a TN (Twisted Nematic), VA (Vertical Alignment), or IPS (In-Plane-Switching) type. When such a liquid crystal layer 114 is provided, the first substrate 121A and the second substrate 121B can be further provided with linear polarizing layers on their respective surfaces to enable them to function as a light-adjusting film.

[0222] A flexible printed circuit board 118 is arranged to provide an electrical connection between the first transparent electrode 122A and the second transparent electrode 122B and the outside. The flexible printed circuit board 118 can be connected, for example, by being positioned between the first transparent electrode 122A and the second transparent electrode 122B in an area where the liquid crystal layer 114 is not in between them. However, the flexible printed circuit board 118 may also be configured not to be positioned between the first transparent electrode 122A and the second transparent electrode 122B.

[0223] In this embodiment, as described above, a first bonding layer 131 is placed between the first glass plate 141 and the liquid crystal cell 110, and a second bonding layer 132 is placed between the second glass plate 142 and the liquid crystal cell 110. The first bonding layer 131 bonds the first glass plate 141 and the liquid crystal cell 110 to each other, and the second bonding layer 132 bonds the second glass plate 142 and the liquid crystal cell 110 to each other. As a result, even if the liquid crystal device 101 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the heat-resistant OCR and OCA will not soften, and it is expected that the occurrence of liquid crystal accumulation, a phenomenon in which the liquid crystal of the liquid crystal cell 110 is unevenly distributed, will be suppressed.

[0224] Preferably, the liquid crystal device 101 does not contain a bonding body containing a pressure-adhesive component. An example of a bonding body containing a pressure-adhesive component is an interlayer made of PVB (polyvinyl butyral) resin. Therefore, an interlayer made of PVB resin or the like is not interposed between the first glass plate 141, the liquid crystal cell 110, and the second glass plate 142, and it is possible to suppress the uneven distribution of liquid crystals in the liquid crystal cell 110 due to the softening of the interlayer made of PVB resin or the like at high temperatures. Note that "a bonding body containing a pressure-adhesive component" refers to a bonding body that requires pressurization (i.e., a pressure greater than normal pressure) in order to properly bond to adjacent objects. Normal pressure is ambient pressure, which is usually equal to atmospheric pressure and can be standard atmospheric pressure.

[0225] (Manufacturing method for dimming devices) Next, the method for manufacturing the liquid crystal device 101 according to this embodiment will be described with reference to Figure 20. Figure 20 is a cross-sectional view showing the method for manufacturing the liquid crystal device 101 according to this embodiment.

[0226] First, prepare the second glass plate 142 as shown in Figure 20(a).

[0227] Next, as shown in Figure 20(b), a second bonding layer 132 made of OCA is bonded to the second glass plate 142. In this case, for example, an OCA sheet having the second bonding layer 132 and a release film 135 is bonded to the second glass plate 142, and then the release film 135 is peeled off to bond the second bonding layer 132 to the second glass plate 142. The second bonding layer 132 may be bonded to the entire area or a portion of one side of the second glass plate 142.

[0228] Next, a liquid crystal cell 110, which has been separately manufactured, is bonded onto the second bonding layer 132, and the liquid crystal cell 110 is bonded to the second glass plate 142 by the second bonding layer 132 (Figure 20(c)). Various known methods can be used for manufacturing the liquid crystal cell 110. The second bonding layer 132, which is made of OCA, is a bonding body that contains a non-pressure adhesive component, as described above. Therefore, the liquid crystal cell 110 and the second glass plate 142 are bonded without pressure (i.e., under ambient pressure (usually atmospheric pressure)). Furthermore, the second bonding layer 132 is bonded to the liquid crystal cell 110 and the second glass plate 142 at room temperature (for example, between 10°C and 30°C).

[0229] Next, an uncured liquid first bonding material 310 is applied to the liquid crystal cell 110 and the second bonding layer 132 exposed around the liquid crystal cell 110, for forming the first bonding layer 131 and the third bonding layer 133 after curing (Figure 20(d)). The first bonding material 310 is an OCR material containing OCR. This OCR material is a liquid curable adhesive layer composition containing a polymerizable compound, and may consist of a liquid curable adhesive layer composition mixed with a base resin such as an acrylic resin, silicone resin, or urethane resin and additives. The first bonding material 310 is applied to the liquid crystal cell 110 and the entire or partial area of ​​one side of the second bonding layer 132 exposed around the liquid crystal cell 110 by an application nozzle 150 such as a dispenser or slit coater. At this time, by adjusting the amount of the first bonding material 310 applied, a region in which the thickness of the first bonding material 310 is thicker and a region in which the thickness of the first bonding material 310 is thinner than that of the thicker region are formed in the area overlapping with the liquid crystal cell 110.

[0230] Next, the first glass plate 141 is prepared and laminated onto the first bonding material 310, and the first glass plate 141 is bonded to the liquid crystal cell 110 and the second bonding layer 132 exposed around the liquid crystal cell 110 using the first bonding material 310 (Figure 20(e)). The first bonding material 310 is OCR and is a bonding body containing a non-pressure adhesive component. Therefore, the first glass plate 141 is bonded to the liquid crystal cell 110 and the second bonding layer 132 exposed around the liquid crystal cell 110 without being pressurized (i.e., under ambient pressure (usually under atmospheric pressure)). Furthermore, the first glass plate 141 is bonded to the liquid crystal cell 110 and the second glass plate 142 at room temperature (for example, between 10°C and 30°C).

[0231] Subsequently, the first bonding material 310 is cured by irradiating the stacked second glass plate 142, second bonding layer 132, liquid crystal cell 110, first bonding material 310, and first glass plate 141 with ultraviolet light (UV) (Figure 20(f)). As the first bonding material 310 hardens, the first bonding layer 131 and the third bonding layer 133, which are made of OCR, are integrally formed. In this way, a liquid crystal device 101 is obtained in which the first glass plate 141, the first bonding layer 131, the liquid crystal cell 110, the second bonding layer 132, the third bonding layer 133, and the second glass plate 142 are stacked on top of each other.

[0232] Here, we will explain the reason for providing a thickness difference in the first bonding layer 131 and the preferred numerical range for the thickness difference. Figure 21 shows a comparative example liquid crystal device 101X, in which no thickness difference is provided in the first bonding layer 131, in a vertical position and exposed to a high-temperature environment. Figure 22 is a plan view of the liquid crystal device 101X shown in Figure 21.

[0233] The liquid crystal apparatus 101X shown in Figure 21 has the same configuration as the liquid crystal apparatus 101 of the embodiment, except that there is no difference in layer thickness in the first bonding layer 131, and will be described using the same reference numerals as the liquid crystal apparatus 101. Also, in Figure 21, the first transparent electrode 122A, the first alignment layer 123A, the second transparent electrode 122B, the second alignment layer 123B, the bead spacer 124, etc. are omitted from the illustration. In addition, the direction of arrow P1 in Figure 21 is the direction of gravity.

[0234] As explained earlier, the difference between the elastic modulus of the first bonding layer 131 at high temperatures (e.g., 90°C) and at room temperature (25°C) is small. This reduces the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the liquid crystal cell 110, even when the liquid crystal device 101 is used in high-temperature environments such as inside a car. However, in high-temperature environments, the liquid crystal inside the liquid crystal cell 110 expands due to thermal expansion, acting as a force that pushes the first bonding layer 131 and the second bonding layer 132 that are in contact with the liquid crystal cell 110. If the force with which the first bonding layer 131 and the second bonding layer 132 push back against the liquid crystal cell 110 is weak, the shape of the liquid crystal cell 110 cannot be maintained, the liquid crystal cell 110 expands freely, the cell gap widens, and liquid crystal unevenness occurs. In particular, because the liquid crystal is pulled in the direction of arrow P1 by gravity, the liquid crystal may accumulate downwards, causing liquid crystal accumulation D1.

[0235] To address the phenomenon of liquid crystal accumulation D1 and the like described above, if the first bonding layer 131 and the second bonding layer 132 exert sufficient force to push back the liquid crystal cell 110 due to thermal expansion in a high-temperature environment, the shape of the liquid crystal cell 110 can be maintained. This allows the cell gap to be maintained, thereby suppressing the occurrence of liquid crystal unevenness. Here, the force pushing the liquid crystal cell 110 can be increased by increasing the thickness of the first bonding layer 131 and the second bonding layer 132. Since the first bonding layer 131 is formed using OCR, the layer thickness can be partially increased by adjusting the amount of coating. Therefore, in this embodiment, the coating distribution of OCR on the first bonding layer 131 is adjusted so that the thickness of the first bonding layer 131 in the first end region 131b is greater than the thickness of the first bonding layer 131 in the inner region 131a. This increases the force that suppresses the expansion of the liquid crystal cell 110 and has the effect of suppressing liquid crystal accumulation D1 caused by the accumulation of liquid crystal at the bottom.

[0236] Two liquid crystal devices of the embodiment and one liquid crystal device of the comparative example were created, and the presence or absence of liquid crystal accumulation in a high-temperature environment was confirmed. Figure 23 shows the distribution of the layer thickness of the first bonding layer 131 of Example 1. Figure 24 shows the distribution of the layer thickness of the first bonding layer 131 of Example 2. Figure 25 shows the distribution of the layer thickness of the first bonding layer 131 of Comparative Example 1. Figure 26 is a diagram illustrating the first end region 131b and the inner region 131a in a plan view.

[0237] In all three liquid crystal devices, Example 1, Example 2, and Comparative Example 1, the liquid crystal cell 110 is a square measuring 280 mm x 280 mm, and the layer configuration is the same as that of the liquid crystal device 101 shown in Figure 19. As shown in Figures 23 to 25, Example 1, Example 2, and Comparative Example 1 have different distributions of the layer thickness of the first bonding layer 131. In all three, the layer thickness of the first bonding layer 131 is based on 100 μm, and the first bonding layer 131 is additionally thickened in areas where the layer thickness is to be increased.

[0238] In all three liquid crystal devices (Example 1, Example 2, and Comparative Example 1), the devices were positioned vertically so that the main surface of the liquid crystal device aligned with the direction of gravity, simulating actual usage conditions. The presence or absence of liquid crystal accumulation was then checked after exposure to a high-temperature environment of 85°C for one hour.

[0239] The graphs in Figures 23 to 25 show the thickness distribution of the first bonding layer 131 in Example 1, Example 2, and Comparative Example 1, respectively, and show the thickness distribution in the cross-section cut at the position of arrow AA in Figure 26. The horizontal axis of the graphs in Figures 23 to 25 shows the distance from the position overlapping with the lower edge of the liquid crystal cell 110 (the lower side when the liquid crystal device is positioned vertically assuming actual use; the lower side of the paper in Figure 26), and the vertical axis shows the thickness of the first bonding layer 131. As shown in these figures, the first end-side region 131b is used so that it is on the lower side when the liquid crystal device is in use. In other words, the inner region 131a, which is adjacent to the first end-side region 131b and extends to the opposite side (the lower side), is provided extending to the upper side of the liquid crystal cell 110 when the liquid crystal device is in use. The layer thickness was measured using a spectroscopic interference type multilayer film thickness measuring instrument SIT10 manufactured by Keyence Corporation, without cutting the liquid crystal device.

[0240] In Example 1, the lower first end region 131b is thicker than the inner region 131a. Also in Example 1, the second end region 131c, which is adjacent to the inner region 131a and extends to the upper side, is also thicker than the inner region 131a. Furthermore, in Example 1, the thickness of the first bonding layer 131 is thickest at the position where it overlaps with the lower end of the liquid crystal cell 110.

[0241] In Example 2, only the lower first end region 131b is thicker than the inner region 131a. Also, in Example 2, the thickness of the first bonding layer 131 is thickest at the position where it overlaps with the lower end of the liquid crystal cell 110.

[0242] In Comparative Example 1, the inner region 131a is thicker than the first end region 131b. Also, in Comparative Example 1, the thickness of the first bonding layer 131 is thickest at a position that overlaps with the center of the liquid crystal cell 110.

[0243] Figure 27 shows the results of evaluating the occurrence of liquid crystal accumulation after exposure to the high-temperature environment described above for each of Example 1, Example 2, and Comparative Example 1.

[0244] In both Example 1 and Example 2, no liquid crystal accumulation was observed, and they were evaluated as "good". In contrast, in Comparative Example 1, liquid crystal accumulation was observed at the bottom, so it was evaluated as "poor". From these results, it was confirmed that by making the layer thickness of the lower first end region 131b of the first bonding layer 131 thicker than that of the inner region 131a, as in Example 1 and Example 2, liquid crystal accumulation within the liquid crystal cell 110 can be suppressed. Furthermore, from Example 1, it can be seen that if the layer thickness of the first bonding layer 131 in the lower first end region 131b is thicker than that of the first bonding layer 131 in the inner region 131a, even if there are regions other than the lower first end region 131b where the layer thickness of the first bonding layer 131 is thicker than that of the inner region 131a, it is effective in suppressing liquid crystal accumulation within the liquid crystal cell 110. In contrast, as in Comparative Example 1, when the thickness of the first end region 131b on the lower end side of the first bonding layer 131 is made thinner than that of the inner region 131a, it was confirmed that liquid crystal accumulation is more likely to occur within the liquid crystal cell 110.

[0245] Furthermore, in order to determine to what extent it is desirable to make the first end region 131b thicker than the inner region 131a, four types of samples with different layer thicknesses in the first end region 131b were prepared, and the occurrence of liquid crystal accumulation after exposure to a high-temperature environment was evaluated in the same manner as in the comparative experiment described above.

[0246] Here, t1 is defined as the average layer thickness of the first end-side region 131b located in the range of 0 mm to less than 80 mm from the position corresponding to the edge of the liquid crystal cell 110 over which the first end-side region 131b overlaps. Furthermore, t0 is defined as the average layer thickness of the inner region 131a located in the range of 80 mm to less than 180 mm from the position corresponding to the edge of the liquid crystal cell 110 over which the first end-side region 131b overlaps. The ratio of these two, t1 / t0, was used as an indicator to evaluate how much thicker the first end-side region 131b should be compared to the inner region 131a. Four values ​​of t1 / t0 were prepared: 0.8, 1.2, 1.4, and 2.5. The sample with t1 / t0 = 0.8 exhibits the same layer thickness distribution of the first bonding layer 131 as in Comparative Example 1. The other samples exhibit the same layer thickness distribution of the first bonding layer 131 as in Example 1.

[0247] Figure 28 summarizes the results of evaluating the effect of t1 / t0 on liquid crystal accumulation. As shown in Figure 28, in the sample with t1 / t0 = 0.8, liquid crystal accumulation was observed after exposure to a high-temperature environment, so it was evaluated as "× (poor)". In the other samples with t1 / t0 of 1.2 or higher, liquid crystal accumulation was not observed after exposure to a high-temperature environment, so it was evaluated as "〇 (good)". From these results, it can be said that satisfying the relationship t1 / t0 ≥ 1.2 is desirable to suppress the occurrence of liquid crystal accumulation after exposure to a high-temperature environment.

[0248] For example, when the liquid crystal device 101 is positioned vertically along the surface of the panel (standing upright), in order to effectively suppress the accumulation of liquid crystal at the bottom, the lower first end region 131b of the first bonding layer 131 should be made thicker than the inner region 131a, and t1 / t0 ≥ 1.2.

[0249] In the above example, when the vertical height is 280 mm, the range of the first end-side region 131b was defined as a distance of 0 mm or more and less than 80 mm from the position corresponding to the end of the liquid crystal cell 110. Also, when the vertical height is 280 mm, the range of the inner region 131a was defined as a distance of 80 mm or more and less than 180 mm from the position corresponding to the end of the liquid crystal cell 110 that overlaps with the first end-side region 131b. That is, the range of the inner region 131a was defined as a distance of 0 mm or more and less than 100 mm from the position adjacent to the first end-side region 131b. The position where liquid crystal accumulation occurs hardly changes whether the vertical height is higher or lower than the above 280 mm. Therefore, even in the case of liquid crystal cells 110 with different vertical heights, applying the above dimensional ranges for the range of the first end-side region 131b and the inner region 131a can effectively suppress liquid crystal accumulation.

[0250] In this embodiment, a first bonding layer 131 is placed between the first glass plate 141 and the liquid crystal cell 110, and a second bonding layer 132 is placed between the second glass plate 142 and the liquid crystal cell 110. The first bonding layer 131 and the second bonding layer 132 are bonding bodies containing non-pressure adhesive components. As a result, the liquid crystal cell 110 is not subjected to high pressure during the manufacturing process of the liquid crystal device 101, and the liquid crystal device 101 can be manufactured at normal pressure. Therefore, no large pressure is applied to the surface of the liquid crystal cell 110, and liquid crystal accumulation, a phenomenon in which the liquid crystal of the liquid crystal cell 110 is locally unevenly distributed, can be suppressed. As a result, the quality and appearance of the liquid crystal device 101 can be improved.

[0251] Furthermore, according to this embodiment, the first bonding layer 131 is made of highly heat-resistant OCR, and the second bonding layer 132 is made of highly heat-resistant OCA. As a result, even if the liquid crystal device 101 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the highly heat-resistant OCA and OCR will not soften, and the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the liquid crystal cell 110, can be reduced. In addition, when the liquid crystal device 101 is placed vertically on a vertical wall or the like in a high-temperature environment, it is possible to suppress the part of the liquid crystal of the liquid crystal layer 114 from falling vertically downward due to gravity, and to make the amount of liquid crystal in the liquid crystal layer 114 uniform across the surface of the liquid crystal device 101. As a result, the phenomenon of unevenness in the appearance of the liquid crystal device 101 (gravity unevenness) can be suppressed, and the quality and appearance of the liquid crystal device 101 can be improved.

[0252] Furthermore, according to this embodiment, the coating distribution of the OCR on the first bonding layer 131 is adjusted so that the lower first end region 131b of the first bonding layer 131 is thicker than the inner region 131a. As a result, even when the liquid crystal device 101 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the expansion of the liquid crystal cells 110 due to liquid crystal expansion is suppressed, and as a result, liquid crystal accumulation can be effectively suppressed. In addition, when the liquid crystal device 101 is placed vertically on a vertical wall or the like in a high-temperature environment, a portion of the liquid crystal in the liquid crystal layer 114 is prevented from falling vertically downward due to gravity, and the amount of liquid crystal in the liquid crystal layer 114 can be made uniform within the plane of the liquid crystal device 101. In particular, by setting t1 / t0 ≥ 1.2, the above effects can be exhibited more effectively. As a result, the occurrence of liquid crystal accumulation in the liquid crystal device 101 exposed to a high-temperature environment can be suppressed, and the quality and appearance of the liquid crystal device 101 can be improved.

[0253] (Transformed form) The embodiments described above are not limited to those described above, and various modifications and changes are possible, all of which fall within the scope of these embodiments.

[0254] (1) In this embodiment, an example in which the first bonding layer 131 and the third bonding layer 133 are OCR and the second bonding layer 132 is OCA has been described. However, the present invention is not limited to this. For example, all of the first bonding layer, the second bonding layer, and the third bonding layer may be OCR. In this case, a configuration in which a layer thickness difference is provided for the layer thickness of the second bonding layer can also be adopted, and the effect of suppressing the liquid crystal accumulation can be enhanced.

[0255] (2) In this embodiment, an example in which the liquid crystal cell 110 is a dimming cell that adjusts the light transmittance has been described. However, the present disclosure is not limited to this, and can be suitably applied to a liquid crystal device including a liquid crystal cell that performs information display.

[0256] (3) In this embodiment, an example in which the liquid crystal device 101 is square in plan view has been described. However, the present invention is not limited to this. For example, the liquid crystal device 101 may be rectangular in plan view, or may be a parallelogram, a trapezoid, or the like, and the shape in plan view can be appropriately changed.

[0257] (4) In this embodiment, an example in which the liquid crystal cell 110 is square in plan view has been described. However, the present invention is not limited to this. For example, the liquid crystal cell may be rectangular in plan view, or may be a parallelogram, a trapezoid, or the like, and the shape in plan view can be appropriately changed.

[0258] (The fifth embodiment) Next, the fifth embodiment will be described with reference to FIGS. 29 to 35. FIGS. 29 to 35 are diagrams showing the fifth embodiment. The fifth embodiment shown in FIGS. 29 to 35 mainly differs in the configurations of the first bonding layer and the liquid crystal layer. In FIGS. 29 to 35, the same parts as those in the fourth embodiment shown in FIGS. 18 to 28 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0259] As shown in FIG. 29, the liquid crystal device 101 (combined glass) according to this embodiment includes a first glass plate 141, a first bonding layer 131, a liquid crystal cell 110, a second bonding layer 132, and a second glass plate 142. The first glass plate 141, the first bonding layer 131, the liquid crystal cell 110, the second bonding layer 132, and the second glass plate 142 are laminated and arranged in this order. Further, a third bonding layer 133 is disposed on the outer peripheral portion of the liquid crystal cell 110.

[0260] In this embodiment, the first bonding layer 131 is disposed between the first glass plate 141 and the liquid crystal cell 110, and is a member that joins the first glass plate 141 and the liquid crystal cell 110 to each other. The first bonding layer 131 is larger in size in plan view than the liquid crystal cell 110. In this embodiment, the first bonding layer 131 is made of OCR (Optical Clear Resin).

[0261] As shown in FIG. 29, in this embodiment, the region of the first bonding layer 131 that overlaps the liquid crystal cell 110 is referred to as the central region 131d, and the region of the first bonding layer 131 disposed outside the liquid crystal cell 110 is referred to as the peripheral region 131e. The thickness of the central region 131d of the first bonding layer 131 needs to be set to an appropriate thickness. This point will be described later. Also, the size of the first bonding layer 131 may be the same as that of the first glass plate 141 and the second glass plate 142, or may be larger than the size of the liquid crystal cell 110 and smaller than the first glass plate 141 and the second glass plate 142.

[0262] The second bonding layer 132 is disposed between the second glass plate 142 and the liquid crystal cell 110, and is a member that joins the second glass plate 142 and the liquid crystal cell 110 to each other. The second bonding layer 132 is larger in size in plan view than the liquid crystal cell 110. In this embodiment, the second bonding layer 132 is made of OCA (Optical Clear Adhesive).

[0263] In this embodiment, the first bonding layer 131 directly bonds the first glass plate 141 and the liquid crystal cell 110. The second bonding layer 132 directly bonds the second glass plate 142 and the liquid crystal cell 110. However, the invention is not limited to this, and a film such as an ultraviolet (UV) cut film may be interposed at least at one location between the first glass plate 141 and the liquid crystal cell 110, and between the second glass plate 142 and the liquid crystal cell 110.

[0264] The outer circumference of the third bonding layer 133 may coincide with the outer circumferences of the first glass plate 141 and the second glass plate 142, or it may be located outside the outer circumferences of the first glass plate 141 and the second glass plate 142. Furthermore, it is preferable that the inner circumference of the third bonding layer 133 coincides with the outer circumference of the liquid crystal cell 110. Details regarding the peripheral region 131e of the first bonding layer 131 and the width Wa of the third bonding layer 133 (see Figure 29) will be described later.

[0265] The first bonding layer 131, the second bonding layer 132, and the third bonding layer 133 are bonded bodies containing non-compressive adhesive components. Here, "bonded bodies containing non-compressive adhesive components" refers to bonded bodies that do not require pressurization to properly adhere to adjacent objects, and that can adhere to adjacent objects to a moderate degree under normal pressure.

[0266] In this embodiment, between the first laminate 112 and the second laminate 113 of the liquid crystal cell 110, the liquid crystal layer 114 has an annular or frame-shaped sealing material 125 in plan view, surrounding the liquid crystal at its outer peripheral edge. This sealing material 125 holds the first laminate 112 and the second laminate 113 together, preventing leakage of the liquid crystal material.

[0267] The viscosity of the liquid crystal used in the liquid crystal layer 114 is preferably 40 to 110 cp at room temperature and 4 to 11 cp at 80°C, and more preferably 50 to 100 cp at room temperature and 5 to 10 cp at 80°C. The viscosity of the liquid crystal is measured using a rheometer HR2 as the measuring device, with a parallel plate, and the ShareRate is 10 to 1000 sec. -1 It is best to measure it that way.

[0268] The liquid crystal device 101 according to this embodiment can be manufactured in the same manner as in the fourth embodiment (see Figure 20).

[0269] Here, we will explain the liquid crystal accumulation that is likely to occur when a liquid crystal device is exposed to a high-temperature environment. Figure 30 shows a comparative example liquid crystal device 101X, in which the thickness of the central region 131d is not set to an appropriate thickness, placed vertically and exposed to a high-temperature environment. Figure 31 is a plan view of the liquid crystal device 101X of Figure 30.

[0270] The liquid crystal device 101X shown in Figure 30 has the same configuration as the liquid crystal device 101 of this embodiment, except that the thickness of the central region 131d is not set to an appropriate thickness and is thinner than the thickness of the central region 131d of this embodiment. Therefore, it will be described using the same reference numerals as the liquid crystal device 101. Also, in Figure 30, the first transparent electrode 122A, the first alignment layer 123A, the second transparent electrode 122B, the second alignment layer 123B, the bead spacer 124, etc. are omitted from the illustration. Also, the direction of arrow P2 in Figure 30 is the direction of gravity. Note that arranging the liquid crystal device vertically means that the main surface of the liquid crystal device is arranged along the direction of gravity.

[0271] As explained earlier, the small difference between the elastic modulus of the first bonding layer 131 at high temperatures (e.g., 90°C) and at room temperature (25°C) reduces the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the liquid crystal cell 110, even when the liquid crystal device 101 is used in a high-temperature environment such as inside a car. However, as in the comparative example liquid crystal device 101X, if there is a third bonding layer 133, which is a thicker portion, in the peripheral region 131e of the first bonding layer 131, the thermal expansion in this portion increases the expansion force as shown by arrow P1. This expansion force in the peripheral region 131e pulls the first substrate 121A in a direction that widens the gap (spacing) of the liquid crystal layer 114 near the peripheral region 131e, which can cause liquid crystal to accumulate in this area, resulting in liquid crystal accumulation D1.

[0272] Furthermore, due to the expansion force in the liquid crystal layer 114 as indicated by arrow P1, the first substrate 121A is pulled in a direction that widens the gap (spacing) in the liquid crystal layer 114, and the liquid crystal is also pulled in the direction of arrow P2 by gravity, which can cause the liquid crystal to accumulate downwards, resulting in the formation of a liquid crystal accumulation D2.

[0273] In contrast, this embodiment suppresses liquid crystal accumulation by three types of configurations, which are shown below as Configuration 1 to Configuration 3.

[0274] (Composition 1) Regarding the phenomenon of liquid crystal accumulation D1, D2, etc., if the force of the first bonding layer 131 pushing back against the liquid crystal cell 110 due to thermal expansion in a high-temperature environment is sufficient, the shape of the liquid crystal cell 110 can be maintained. This force pushing back against the liquid crystal cell 110 becomes stronger as the thickness of the first bonding layer 131 increases. Furthermore, the phenomenon of liquid crystal accumulation D1, D2, etc., is also affected by the amount of liquid crystal layer 114 in the liquid crystal cell 110. Since the amount of liquid crystal layer 114 in the liquid crystal cell 110 is proportional to the cross-sectional area of ​​the liquid crystal layer 114, it is thought that the thickness of the first bonding layer 131 necessary to suppress liquid crystal accumulation changes depending on the cross-sectional area of ​​the liquid crystal layer 114. Therefore, the presence or absence of liquid crystal accumulation was evaluated by changing the thickness of the first bonding layer 131 for multiple liquid crystal cells 110 with different cross-sectional areas of the liquid crystal layer 114. In this evaluation, the plates were arranged vertically so that the surface was aligned with the direction of gravity, simulating actual usage conditions, and the presence or absence of liquid crystal accumulation was checked after exposure to a high-temperature environment of 85°C for 1 hour.

[0275] Figure 32 shows the results of evaluating the occurrence of liquid crystal accumulation by changing the cross-sectional area of ​​the liquid crystal layer 114 and the thickness of the first bonding layer 131. In Figure 32, the thickness of the first bonding layer 131 is the thickness in the area that overlaps with the liquid crystal cell 110. Also, the liquid crystal cell gap t in Figure 32 is the distance between the first laminate 112 and the second laminate 113 shown in Figure 29. The liquid crystal cell length L in Figure 32 is the length of the liquid crystal cell 110 shown in Figure 29, and is the vertical length of the liquid crystal cell 110 when the liquid crystal device 101 is arranged vertically so that the plate surface is aligned with the direction of gravity, assuming actual usage conditions.

[0276] Here, the cross-sectional area of ​​the liquid crystal layer 114 can be calculated by t × L, and is the area enclosed by the thick line in Figure 29. Also, as explained earlier, the liquid crystal layer 114 has a sealing material 125. Therefore, the cross-sectional area of ​​the liquid crystal layer 114 in this disclosure includes the cross-sectional area of ​​the sealing material 125 in addition to the cross-sectional area of ​​the portion filled with liquid crystal. If the surface shape of the liquid crystal device 101 is curved, and the surface shape of the liquid crystal cell 110 is also curved, then the length L of the liquid crystal cell 110 is the vertical length of the liquid crystal cell 110 along the curved surface of the liquid crystal cell 110. Note that the length L of the liquid crystal cell 110 is the length of the longest straight line that connects the two opposing sides of the liquid crystal cell 110, perpendicular to at least one of the two opposing sides. In other words, the cross-sectional area of ​​the liquid crystal layer 114 used for evaluation is assumed to be the cross-section with the largest cross-sectional area in the vertical direction when the liquid crystal device 101 is arranged vertically so that the plate surface is aligned with the direction of gravity, assuming the actual usage state. In other words, when the liquid crystal cell gap t is uniform, the cross-section where the liquid crystal cell length L is longest is assumed. Also, the coefficient of linear expansion of the first bonding layer 131 used in the evaluation in Figure 32 is 30.6(E -5 The temperature is (°C), and the peripheral region of the first bonding layer 131 located outside the liquid crystal cell 110, and the width Wa of the third bonding layer 133 are 10 mm.

[0277] In Figure 32, a × (poor) rating indicates that liquid crystal accumulation occurred, while a ○ (good) rating indicates that liquid crystal accumulation did not occur. As can be seen from Figure 32, when the cross-sectional area of ​​the liquid crystal layer 114 changes, the minimum thickness of the first bonding layer 131 required to suppress liquid crystal accumulation also changes, indicating a certain relationship. Therefore, for each cross-sectional area of ​​the liquid crystal cell 110, the minimum thickness of the first bonding layer 131 required to suppress liquid crystal accumulation was selected and graphed to analyze the relationship between the two.

[0278] FIG. 33 is a graph showing the cross-sectional area of the liquid crystal layer 114 and the range for suppressing the liquid crystal accumulation. In FIG. 33, the cross-sectional area of the liquid crystal layer 114 is represented as X, and the thickness of the first bonding layer 131 in the range overlapping with the liquid crystal cell 110 is represented as Y. In FIG. 33, data near the boundary between the range where the liquid crystal accumulation can be suppressed and the range where it cannot be suppressed are extracted from the data in FIG. 32 and plotted. In FIG. 33, the plotted circles are data where the liquid crystal accumulation can be suppressed, and the plotted crosses are data where the liquid crystal accumulation cannot be suppressed. The straight line shown in this figure can be expressed by the following equation. Y = 110X - 170

[0279] Therefore, if the thickness of the first bonding layer 131 is set to be greater than or equal to the thickness Y obtained from the above equation, the liquid crystal accumulation when exposed to a high-temperature environment can be suppressed. Thus, it is preferable that the cross-sectional area X of the liquid crystal layer 114 and the thickness Y of the first bonding layer 131 satisfy the following relationship. Y ≧ 110X - 170

[0280] (Configuration 2) Also, if the linear expansion coefficients of the OCR used for the first bonding layer 131 are different, it is conceivable that the force by which the first bonding layer 131 pushes back the liquid crystal cell 110 due to thermal expansion is different in a high-temperature environment. Therefore, using a plurality of samples with different linear expansion coefficients of the OCR used for the first bonding layer 131, the presence or absence of liquid crystal accumulation in a high-temperature environment was evaluated. Also, two types of layer thicknesses of the first bonding layer 131, 100 μm and 300 μm, were used. This evaluation was carried out by arranging the plate surface vertically along the gravitational direction assuming the actual use state and checking for the presence or absence of liquid crystal accumulation after exposing it to a high-temperature environment of 85° C for 1 hour. Also, the cross-sectional area of the liquid crystal layer 114 used for this evaluation was 3.36 mm 2 and the width Wa of the peripheral region 131e of the first bonding layer 131 and the third bonding layer 133 was 10 mm.

[0281] The measurement of the average linear expansion coefficient was performed using the TMA (Thermo-mechanical Analysis) method. The measurement conditions are as follows. Measuring device: Micro Load Thermo Expansion System manufactured by Rigaku Corporation Measurement mode: constant-rate temperature rise measurement Measurement temperature range: 25℃~85℃ Heating rate: 2°C / min Measurement atmosphere: Under nitrogen Reference: Quartz glass Load capacity: 0.5g (compression load) Measurement n: 1 Measurement direction: Thickness direction of the test sample

[0282] Figure 34 shows the results of evaluating the presence or absence of liquid crystal accumulation in a high-temperature environment by changing the average linear expansion coefficient of the OCR used in the first bonding layer 131. In Figure 34, a × (poor) rating indicates that liquid crystal accumulation occurred, and a ○ (good) rating indicates that liquid crystal accumulation did not occur.

[0283] In the evaluation shown in Figure 32 above, the average coefficient of linear expansion of the OCR used for the first bonding layer 131 was 30.6(E -5 Since the result was ( / ℃), the first bonding layer 131 was evaluated as good (〇) when its thickness was 300 μm. However, from the evaluation results in Figure 34, it can be seen that even when the condition Y≧110X-170 is met, if the average coefficient of linear expansion is too small, the occurrence of liquid crystal accumulation cannot be suppressed. And, as can be seen from Figure 34, the average coefficient of linear expansion of the OCR used in the first bonding layer 131 from 25℃ to 85℃ is 24.7(E -5 A temperature of 0°C or higher is desirable to suppress the occurrence of liquid crystal buildup.

[0284] (Composition 3) As explained in Figure 30 above, the presence of the third bonding layer 133, which is a thicker portion in the peripheral region 131e of the first bonding layer 131, is a major factor in the occurrence of liquid crystal accumulation. Therefore, it may be possible to control the occurrence of liquid crystal accumulation by changing the way the peripheral region 131e expands. Accordingly, the occurrence of liquid crystal accumulation was evaluated by changing the width Wa of the peripheral region 131e of the first bonding layer 131 and the third bonding layer 133. In this evaluation, the average linear expansion coefficient of the OCR used for the first bonding layer 131 was set to 30.6(E -5The evaluation was carried out under the same conditions as in Figure 34, except that the temperature was set to / ℃ and the thickness of the first bonding layer 131 was set to 300 μm.

[0285] Figure 35 shows the results of evaluating the occurrence of liquid crystal accumulation D2 by changing the peripheral region 131e of the first bonding layer 131 and the width Wa of the third bonding layer 133. In Figure 35, a × (poor) evaluation indicates that liquid crystal accumulation D2 occurred, and a ○ (good) evaluation indicates that liquid crystal accumulation D1 and D2 did not occur. The evaluation in Figure 35 focuses on the liquid crystal accumulation D2 shown in Figure 31.

[0286] From the results in Figure 35, it can be said that in order to suppress liquid crystal accumulation that occurs inside the liquid crystal cell 110, such as liquid crystal accumulation D2, it is desirable that the peripheral region 131e of the first bonding layer 131 and the width Wa of the third bonding layer 133 be 10 mm or more. By widening the peripheral region 131e of the first bonding layer 131 and the width Wa of the third bonding layer 133, the expansion force of the first bonding layer 131 and the third bonding layer 133 on the outer periphery of the liquid crystal cell 110 increases. As a result, the warping of the first glass plate 141 and the second glass plate 142 increases, and the force pressing down on the central side of the liquid crystal cell 110 increases, which is thought to suppress the occurrence of liquid crystal accumulation D2. From the results in Figure 35, when prioritizing the suppression of liquid crystal accumulation D2, it is desirable that the peripheral region 131e of the first bonding layer 131 and the width Wa of the third bonding layer 133 be 10 mm or more.

[0287] In this embodiment, a first bonding layer 131 is placed between the first glass plate 141 and the liquid crystal cell 110, and a second bonding layer 132 is placed between the second glass plate 142 and the liquid crystal cell 110. The first bonding layer 131 and the second bonding layer 132 are bonding bodies containing non-pressure adhesive components. As a result, the liquid crystal cell 110 is not subjected to high pressure during the manufacturing process of the liquid crystal device 101, and the liquid crystal device 101 can be manufactured at normal pressure. Therefore, no large pressure is applied to the surface of the liquid crystal cell 110, and liquid crystal accumulation, a phenomenon in which the liquid crystal of the liquid crystal cell 110 is locally unevenly distributed, can be suppressed. As a result, the quality and appearance of the liquid crystal device 101 can be improved.

[0288] Furthermore, according to this embodiment, the first bonding layer 131 is made of highly heat-resistant OCR, and the second bonding layer 132 is made of highly heat-resistant OCA. As a result, even if the liquid crystal device 101 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the highly heat-resistant OCA and OCR will not soften, and the occurrence of liquid crystal accumulation, a phenomenon in which a large amount of liquid crystal is locally present in the liquid crystal cell 110, can be reduced. In addition, when the liquid crystal device 101 is placed vertically on a vertical wall or the like in a high-temperature environment, it is possible to suppress the part of the liquid crystal of the liquid crystal layer 114 from falling vertically downward due to gravity, and to make the amount of liquid crystal in the liquid crystal layer 114 uniform across the surface of the liquid crystal device 101. As a result, the phenomenon of unevenness in the appearance of the liquid crystal device 101 (gravity unevenness) can be suppressed, and the quality and appearance of the liquid crystal device 101 can be improved.

[0289] Furthermore, according to this embodiment, by ensuring that the cross-sectional area X of the liquid crystal layer 114 and the thickness Y of the first bonding layer 131 satisfy the relationship Y ≥ 110X - 170, liquid crystal accumulation can be suppressed more reliably. By designing to satisfy the above relationship, development time, which involves repeatedly prototyping and testing to find the appropriate conditions, can be significantly reduced. In addition, by setting the average linear expansion coefficient of the OCR used in the first bonding layer 131 to an appropriate value, and further setting the peripheral region 131e of the first bonding layer 131 and the width Wa of the third bonding layer 133 to appropriate dimensions, the occurrence of liquid crystal accumulation can be suppressed more effectively. As a result, the occurrence of liquid crystal accumulation in the liquid crystal device 101 exposed to high-temperature environments can be suppressed, and the quality and appearance of the liquid crystal device 101 can be improved.

[0290] (Transformed form) The embodiments described above are not limited to those described above, and various modifications and changes are possible, all of which fall within the scope of these embodiments.

[0291] (1) In this embodiment, an example was given in which the first bonding layer 131 and the third bonding layer 133 are OCR and the second bonding layer 132 is OCA. However, the embodiment is not limited to this, and for example, all of the first bonding layer, second bonding layer and third bonding layer may be OCR.

[0292] (2) In this embodiment, the liquid crystal cell 110 was described as a dimming cell that adjusts the light transmittance. However, the present disclosure is not limited to this and can be suitably applied to liquid crystal devices that include liquid crystal cells for displaying information.

[0293] (3) In this embodiment, the liquid crystal device 101 was described as being a square in plan view. However, it is not limited to this, and for example, the liquid crystal device 101 may be a rectangle, a parallelogram, a trapezoid, etc. in plan view, and the shape in plan view can be changed as appropriate.

[0294] (Sixth Embodiment) Next, a sixth embodiment will be described with reference to Figures 36 to 40. Figures 36 to 40 are diagrams showing the sixth embodiment. The sixth embodiment shown in Figures 36 to 40 mainly differs in the configuration of the first bonding layer. In Figures 36 to 40, the same reference numerals are used for parts that are the same as those in the fourth embodiment shown in Figures 18 to 28, and detailed descriptions are omitted.

[0295] Figure 36 is an exploded perspective view showing the configuration of the liquid crystal device 101 according to this embodiment. As shown in Figure 36, the liquid crystal device 101 according to this embodiment comprises a first glass plate 141, a first bonding layer 131, a liquid crystal cell 110, a second bonding layer 132, and a second glass plate 142, which are stacked in the order described above in the thickness direction.

[0296] As shown in Figure 37, in a cross-sectional view, the first bonding layer 131 is formed not only in the area overlapping with the liquid crystal cell 110 but also in the area corresponding to the periphery of the liquid crystal cell 110, and is connected to the second bonding layer 132 in this area. By shaping the first bonding layer 131 in this way, it is possible to prevent the side surface or part thereof of the liquid crystal cell 110 from being exposed to the side surface of the liquid crystal device 101, and to suppress the intrusion of moisture and other substances from the side surface of the liquid crystal device 101, thereby further improving the water-impermeable properties of the liquid crystal device 101.

[0297] In this embodiment, the first bonding layer 131 is composed of OCR (Optical Clear Resin). OCR is a cured product obtained by curing a liquid curable adhesive layer composition containing a polymerizable compound. Specifically, OCR is obtained by applying a liquid resin, which is a mixture of a base resin such as an acrylic resin, silicone resin, or urethane resin and an additive, to an object and then curing it using ultraviolet light (UV) or the like. The first bonding layer 131 is optically transparent and preferably also has heat resistance up to at least about 120°C, heat and humidity resistance, and weather resistance.

[0298] From the viewpoint of reducing liquid crystal unevenness that occurs when the liquid crystal device 101 is exposed to a high-temperature environment, it is preferable that the first bonding layer 131 has a small difference between its storage modulus at room temperature (25°C) and its storage modulus at high temperature (e.g., 85°C).

[0299] Specifically, let E1 be the storage modulus of the first bonding layer 131 at room temperature (25°C), and E2 be the storage modulus at high temperature (85°C), with the ratio of these storage moduli being E2 / E1. In this case, the change (percentage of change) V(%) from the storage modulus at room temperature to the storage modulus at high temperature is expressed by the following formula. V=1-(E2 / E1) (Formula 1)

[0300] The change in storage modulus V (%) obtained by (Equation 1) is preferably 0% or more and 30% or less. Furthermore, from the viewpoint of reducing liquid crystal unevenness that occurs when the liquid crystal device 101 is exposed to a high-temperature environment, the change V is more preferably 2.7% or more and 22.7% or less.

[0301] The storage modulus of the first bonding layer 131 can be measured using, for example, a DMA measuring device (dynamic viscoelasticity measuring device, such as the Rheogel-E4000 manufactured by UBM Co., Ltd.). The change in the storage modulus V of the first bonding layer 131 will be described in detail later.

[0302] Next, the curing shrinkage rate of the first bonding layer 131 is preferably 2.3% or less, from the viewpoint of reducing liquid crystal unevenness. The curing shrinkage rate (%) can be calculated as 1 - (specific gravity of liquid resin / specific gravity of cured resin). The specific gravity can be measured using a hydrometer. The curing shrinkage rate of this first bonding layer 131 will be described in detail later.

[0303] The thickness of the first bonding layer 131 may be appropriately selected depending on its material and other factors. Specifically, the thickness of the first bonding layer 131 in the region overlapping with the liquid crystal cell 110 in a plan view may be 30 μm or more and 1000 μm or less. Furthermore, the size of the first bonding layer 131 may be the same as the first glass plate 141 and the second glass plate 142, or it may be larger than or equal to the size of the liquid crystal cell 110 and smaller than the first glass plate 141 and the second glass plate 142.

[0304] The second bonding layer 132 is positioned between the second glass plate 142 and the liquid crystal cell 110, and is a component that bonds the second glass plate 142 and the liquid crystal cell 110 together. The second bonding layer 132 is larger in size than the liquid crystal cell 110 when viewed from above. In this embodiment, the second bonding layer 132 is made of OCA (Optical Clear Adhesive).

[0305] The second bonding layer 132, made of OCA, is optically transparent and preferably also has heat resistance up to at least 120°C, heat and humidity resistance, and weather resistance. In this embodiment, the second bonding layer 132 is described as being made of OCA, but it is not limited to this and may be made of OCR in the same way as the first bonding layer 131.

[0306] In this embodiment, the first bonding layer 131 directly bonds the first glass plate 141 and the liquid crystal cell 110. The second bonding layer 132 directly bonds the second glass plate 142 and the liquid crystal cell 110. However, the invention is not limited to these configurations, and a film, such as an ultraviolet (UV) cut film, may be interposed at least at one location between the first glass plate 141 and the liquid crystal cell 110, and between the second glass plate 142 and the liquid crystal cell 110.

[0307] In this embodiment, as described above, a first bonding layer 131 is placed between the first glass plate 141 and the liquid crystal cell 110, and a second bonding layer 132 is placed between the second glass plate 142 and the liquid crystal cell 110. The first bonding layer 131 bonds the first glass plate 141 and the liquid crystal cell 110 to each other, and the second bonding layer 132 bonds the second glass plate 142 and the liquid crystal cell 110 to each other. As a result, even if the liquid crystal device 101 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the heat-resistant OCR and OCA will not soften, suppressing phenomena such as liquid crystal accumulation, which is a phenomenon in which the liquid crystal of the liquid crystal cell 110 is unevenly distributed, and reducing liquid crystal unevenness can be expected.

[0308] It is preferable that the liquid crystal device 101 does not contain a bonding body containing a pressure-adhesive component. An example of a bonding body containing a pressure-adhesive component is an interlayer made of PVB (polyvinyl butyral) resin. A "bonding body containing a pressure-adhesive component" refers to a bonding body that requires pressurization (i.e., a pressure greater than normal pressure) to properly bond to an adjacent object. Normal pressure is the ambient pressure, which is usually equal to atmospheric pressure and can be standard atmospheric pressure. Such an interlayer made of PVB or the like may soften in a high-temperature environment, which can cause liquid crystal unevenness, such as liquid crystal accumulation where the liquid crystal of the liquid crystal cell 110 is unevenly distributed. In contrast, in the liquid crystal device 101 of this embodiment, since there is no interlayer made of PVB resin or the like between the first glass plate 141 and the liquid crystal cell 110, and between the second glass plate 142 and the liquid crystal cell 110, the above-mentioned liquid crystal unevenness can be suppressed.

[0309] (Manufacturing method for dimming devices) Next, the manufacturing method of the liquid crystal device 101 according to this embodiment will be explained with reference to Figure 38. Figure 38 is a diagram showing the manufacturing method of the liquid crystal device 101 according to this embodiment. In Figure 38, the manufacturing method is explained using a cross-sectional view of the liquid crystal device 101.

[0310] First, prepare the second glass plate 142 as shown in Figure 38(a).

[0311] Next, as shown in Figure 38(b), a second bonding layer 132 made of OCA is bonded to the second glass plate 142. In this case, for example, an OCA sheet having the second bonding layer 132 and a release film 135 is bonded to the second glass plate 142, and then the release film 135 is peeled off to bond the second bonding layer 132 to the second glass plate 142. The second bonding layer 132 may be bonded to the entire area of ​​one side of the second glass plate 142, or to a part of it.

[0312] Next, as shown in Figure 38(c), a separately manufactured liquid crystal cell 110 is bonded onto the second bonding layer 132, and the liquid crystal cell 110 is bonded to the second glass plate 142 by the second bonding layer 132. Various known methods can be used for manufacturing the liquid crystal cell 110. The second bonding layer 132, made of OCA, is a bonding body containing a non-pressure adhesive component, as described above. Therefore, the liquid crystal cell 110 and the second glass plate 142 are bonded without pressure (i.e., under ambient pressure (usually atmospheric pressure)). Furthermore, the second bonding layer 132 is bonded to the liquid crystal cell 110 and the second glass plate 142 at room temperature (for example, between 10°C and 30°C).

[0313] Next, as shown in Figure 38(d), an uncured liquid first bonding material 310 is applied to the liquid crystal cell 110. The first bonding material 310 will become the first bonding layer 131 after curing, and is an OCR material containing OCR. This OCR material is a liquid curable adhesive layer composition containing a polymerizable compound, and may consist of a liquid curable adhesive layer composition obtained by mixing a base resin such as an acrylic resin, silicone resin, or urethane resin with additives. The first bonding material 310 is applied to the entire or partial area of ​​one side of the liquid crystal cell 110, for example, by an application nozzle 150 such as a dispenser or slit coater.

[0314] Next, as shown in Figure 38(e), a first glass plate 141 is prepared, and the first glass plate 141 is laminated onto the first bonding material 310. The first glass plate 141 is then bonded to the liquid crystal cell 110 using the first bonding material 310. As mentioned above, the first bonding material 310 is an OCR material containing OCR, and is a bonding body containing a non-pressure adhesive component. Therefore, the first glass plate 141 is bonded to the liquid crystal cell 110 without being pressurized (i.e., under ambient pressure (usually atmospheric pressure)). Furthermore, the first glass plate 141 is bonded to the liquid crystal cell 110 and the second glass plate 142 at room temperature (for example, between 10°C and 30°C).

[0315] Subsequently, as shown in Figure 38(f), the first bonding material 310 is cured by irradiating the stacked second glass plate 142, second bonding layer 132, liquid crystal cell 110, first bonding material 310, and first glass plate 141 with ultraviolet light (UV). As the first bonding material 310 hardens, the first bonding layer 131 made of OCR is formed.

[0316] In this way, a liquid crystal device 101 is obtained in which the first glass plate 141, the first bonding layer 131, the liquid crystal cell 110, the second bonding layer 132, and the second glass plate 142 are stacked on top of each other.

[0317] (With respect to the change in the storage modulus V) Next, we will explain why the change V from the storage modulus E1 at room temperature (25°C) to the storage modulus E2 at high temperature (85°C) is preferably between 0% and 30%.

[0318] Figure 39 shows the comparative example liquid crystal device 101X in a vertical position exposed to a high-temperature environment. Here, vertical positioning of the liquid crystal device means arranging it so that its main surface is aligned with the direction of gravity (vertical direction). Figure 40 is a plan view of the liquid crystal device 101X shown in Figure 39.

[0319] The liquid crystal apparatus 101X shown in Figure 39 has the same configuration as the liquid crystal apparatus 101 of this embodiment, except that the change in storage modulus V is greater than 30%, and will be described using the same reference numerals as the liquid crystal apparatus 101. Also, Figure 39 shows a cross-section of the liquid crystal apparatus 101X, and the first transparent electrode 122A, the first alignment layer 123A, the second transparent electrode 122B, the second alignment layer 123B, the bead spacer 124, etc. are omitted from the illustration. In addition, the direction of arrow P1 in Figure 39 is the direction of gravity.

[0320] Under normal temperature conditions, the forces pushing against each other by the liquid crystal layer 114 and the first bonding layer 131 in the liquid crystal device 101X are balanced, and the movement of the liquid crystal is suppressed. However, when the liquid crystal device 101X is used in a high-temperature environment such as inside a car, the liquid crystal in the first bonding layer 131 and the liquid crystal layer 114 expands, and the first substrate 121A, second substrate 121B, etc., soften. As a result, the above-mentioned balance is disrupted, and the expansion of the liquid crystal layer 114 pulls the first substrate 121A in a direction that widens the gap (spacing, thickness) of the liquid crystal layer 114. In addition, since the liquid crystal is pulled by gravity in the direction of arrow P1, the liquid crystal accumulates downward, causing a liquid crystal accumulation D1 as shown in Figure 40, which may result in liquid crystal unevenness.

[0321] In contrast, in this embodiment, the change V from the storage modulus E1 at room temperature (25°C) to the storage modulus E2 at high temperature (85°C) is 0% to 30%, and more preferably, the change V is 2.7% to 22.7%. As a result, even in high-temperature environments, the balance of forces between each layer, such as the liquid crystal layer 114 and the first bonding layer 131, is maintained, and the widening of the gap in the liquid crystal layer 114 due to liquid crystal expansion can be suppressed. As a result, since the gap in the liquid crystal layer 114 is maintained, the downward movement of the liquid crystal due to gravity can be suppressed, the occurrence of liquid crystal accumulation D1 and the like can be reduced, and liquid crystal uniformity can be greatly improved.

[0322] Here, samples 1 to 6 of the first bonding layer 131, each consisting of OCR with a different change in storage modulus V, were prepared. These were then applied to the liquid crystal apparatus 101 of this embodiment, and the presence or absence of liquid crystal unevenness under high-temperature conditions was evaluated.

[0323] The measuring apparatus and conditions for the storage modulus of each sample are as follows: Measurement device: DMA measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) Measurement conditions Compression measurement Initial load, automatic static load Frequency 1Hz Strain, static load: 0.5% Temperature 25℃,85℃

[0324] Each sample measured 10 mm x 10 mm and had a thickness of 1.0 mm to 2.5 mm. Furthermore, a liquid crystal device 101 was fabricated using the first bonding layer 131 of each of the samples 1 to 6, and the presence or absence of liquid crystal unevenness was visually confirmed after being left in a high-temperature environment for 60 minutes.

[0325] In this case, in the liquid crystal apparatus 101 using the first bonding layer 131 of each sample, the thickness (gap) of the liquid crystal layer 114 is 12 μm, and the thickness of the liquid crystal cell 110 is 260 μm. Furthermore, the thickness of the first bonding layer 131 in the region corresponding to the liquid crystal cell 110 is 300 μm, the planar dimensions of the liquid crystal apparatus are 300 mm x 300 mm, and the planar dimensions of the liquid crystal cell 110 are 280 mm x 280 mm.

[0326] [Table 1]

[0327] Table 1 summarizes the change in storage modulus V for samples 1 to 6 and the presence or absence of liquid crystal unevenness under high-temperature conditions. As shown in Table 1, liquid crystal devices equipped with the first bonding layer 131 of samples 4, 5, and 6, where the change in storage modulus V is between 0% and 30%, did not exhibit liquid crystal unevenness under high-temperature conditions. On the other hand, liquid crystal devices equipped with the first bonding layer 131 of samples 1, 2, and 3, where the change in storage modulus V exceeds 30%, exhibited liquid crystal unevenness. Therefore, for the first bonding layer 131 made of OCR, the change in storage modulus V from E1 under normal temperature (25°C) to E2 under high-temperature (85°C) conditions is preferably between 0% and 30%, and more preferably between 2.7% and 22.7%.

[0328] (Regarding hardening shrinkage rate) Next, we will explain the reason for specifying the curing shrinkage rate of the first bonding layer 131.

[0329] As described above, the first bonding layer 131 is formed by OCR and is liquid in its uncured state, curing upon irradiation with ultraviolet (UV) light. If the curing shrinkage rate at this time is greater than 2.3%, the liquid crystal cells 110 in contact with the first bonding layer 131 are pulled as the first bonding layer 131 hardens, weakening the force that regulates the gap (spacing, thickness) of the liquid crystal layer 114, resulting in uneven liquid crystal formation upon completion of curing. For these reasons, the curing shrinkage rate of the first bonding layer 131 is preferably 2.3% or less.

[0330] The first bonding layers 131 of the aforementioned samples 1 to 6 were prepared and applied to the liquid crystal apparatus 101 of this embodiment, and the liquid crystal unevenness after curing of the first bonding layer 131 of each sample was evaluated. The curing shrinkage rates of samples 1 to 6 differ as follows.

[0331] Sample 1 had a curing shrinkage rate of 3.0%, Sample 2 had a curing shrinkage rate of 2.3%, Sample 3 had a curing shrinkage rate of 2.5%, Sample 4 had a curing shrinkage rate of 1.7%, Sample 5 had a curing shrinkage rate of 1.5%, and Sample 6 had a curing shrinkage rate of 0.8%.

[0332] The presence or absence of liquid crystal unevenness was visually confirmed by irradiating each sample, which consisted of OCR, with ultraviolet light to cure the first bonding layer 131, and then placing the liquid crystal device flat (positioned so that the main surface of the liquid crystal device was aligned horizontally).

[0333] [Table 2]

[0334] Table 2 summarizes the curing shrinkage rates of samples 1 to 6 and the presence or absence of liquid crystal unevenness under high-temperature conditions. In Table 2, the samples are listed from left to right in descending order of curing shrinkage rate. As shown in Table 2, no liquid crystal unevenness was observed after curing in liquid crystal devices equipped with the first bonding layer 131 of samples 2, 4, 5, and 6, which had a curing shrinkage rate of 2.3% or less. In contrast, liquid crystal unevenness was observed after curing in liquid crystal devices equipped with the first bonding layer 131 of samples 1 and 3, which had a curing shrinkage rate greater than 2.3%. Therefore, it is preferable that the curing shrinkage rate of the first bonding layer 131 made of OCR be 2.3% or less.

[0335] Based on the above, it is preferable that the first bonding layer 131 has a change amount V from the storage modulus E1 at room temperature (25°C) to the storage modulus E2 at high temperature (85°C) of 0% or more and 30% or less, and more preferably 2.7% or more and 22.7% or less. Furthermore, it is preferable that the curing shrinkage rate of the first bonding layer 131 is 2.3% or less. Liquid crystal devices equipped with the first bonding layer 131 of samples 4, 5, and 6 that satisfy the above conditions are good liquid crystal devices with suppressed liquid crystal unevenness.

[0336] As described above, according to this embodiment, a first bonding layer 131 is placed between the first glass plate 141 and the liquid crystal cell 110, and a second bonding layer 132 is placed between the second glass plate 142 and the liquid crystal cell 110. The first bonding layer 131 and the second bonding layer 132 are bonding bodies containing non-pressure adhesive components. As a result, the liquid crystal cell 110 is not subjected to high pressure during the manufacturing process of the liquid crystal device 101, and the liquid crystal device 101 can be manufactured at normal pressure. Therefore, no large pressure is applied to the surface of the liquid crystal cell 110, and liquid crystal accumulation, a phenomenon in which the liquid crystal of the liquid crystal cell 110 is locally unevenly distributed, can be suppressed. As a result, the quality and appearance of the liquid crystal device 101 can be improved.

[0337] Furthermore, according to this embodiment, the first bonding layer 131 is made of heat-resistant OCR, and the second bonding layer 132 is made of heat-resistant OCA. As a result, even if the liquid crystal device 101 is placed in a high-temperature environment such as inside a vehicle in the middle of summer, the heat-resistant OCA and OCR will not soften, and the occurrence of liquid crystal unevenness such as liquid crystal accumulation can be reduced.

[0338] Furthermore, according to this embodiment, it is the amount of change (percentage of change) from the storage modulus E1 of the first bonding layer 131 made of OCR at room temperature (25°C) to the storage modulus E2 at high temperature (85°C). Also, the amount of change V obtained by (Equation 1) above is 0% or more and 30% or less, more preferably 2.7% or more and 22.7% or less. Therefore, when the liquid crystal device 101 is placed vertically in a high-temperature environment, it is possible to suppress liquid crystal unevenness caused by a part of the liquid crystal of the liquid crystal layer 114 falling vertically downward due to gravity, and to make the amount of liquid crystal of the liquid crystal layer 114 uniform within the plane of the liquid crystal device 101. This makes it possible to improve the quality and appearance of the liquid crystal device 101.

[0339] Furthermore, according to this embodiment, the first bonding layer 131 is made of OCR and has a curing shrinkage rate of 2.3% or less, so liquid crystal unevenness such as liquid crystal accumulation that occurs when the curing of the first bonding layer 131 is completed can be reduced.

[0340] (Transformed form) The embodiments described above are not limited to those described above, and various modifications and changes are possible, all of which fall within the scope of these embodiments.

[0341] (1) In this embodiment, the liquid crystal cell 110 was described as a dimming cell that adjusts the light transmittance. However, this embodiment is not limited to this and can be suitably applied to liquid crystal devices that include liquid crystal cells that display information.

[0342] (2) In this embodiment, an example was given in which the first bonding layer 131 is OCR and the second bonding layer 132 is OCA. However, the invention is not limited to this, and for example, both the first bonding layer and the second bonding layer may be OCR. In this case, in the manufacturing process of the liquid crystal device 101, it is preferable that the second bonding layer 132 is formed by applying the OCR material to the second glass plate 142 and semi-curing it, and then laminating the liquid crystal cell 110 etc. on top of it. In this case, it is also preferable that the second bonding layer 132 made of OCR has a curing shrinkage rate of 2.3% or less, and the change in storage modulus V shown in (Equation 1) above is 0% or more and 30% or less.

[0343] It is also possible to combine the multiple components disclosed in each of the above embodiments, modified forms, and variations as needed. Alternatively, some components may be removed from all the components shown in each of the above embodiments, modified forms, and variations.

Claims

1. First transparent substrate and The second transparent substrate and A liquid crystal cell disposed between the first transparent substrate and the second transparent substrate, A first bonding layer disposed between the first transparent substrate and the liquid crystal cell, A second bonding layer disposed between the second transparent substrate and the liquid crystal cell, Equipped with, The first bonding layer is OCR, and the amount of change V from the storage modulus E1 at a normal temperature environment of 25°C to the storage modulus E2 at a high temperature environment of 85°C is 0% or more and 30% or less, in a liquid crystal device. However, V = 1 - (E2 / E1).

2. In the liquid crystal apparatus described in claim 1, A liquid crystal device in which the amount of change V is 2.7% or more and 22.7% or less.

3. In the liquid crystal apparatus according to claim 1 or claim 2, A liquid crystal apparatus in which the curing shrinkage rate of the first bonding layer is 2.3% or less.

4. In the liquid crystal apparatus according to any one of claims 1 to 3, A liquid crystal device that does not contain a bonding body containing pressure-bonding adhesive components.

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