Liquid crystal cells, liquid crystal devices

Abstract

To provide a liquid crystal cell and liquid crystal device that can suppress exudation of a liquid crystal material even when the liquid crystal device is exposed under a high-temperature environment.SOLUTION: A liquid crystal cell 10 comprises: a first laminate body 12; a second laminate body 13; a liquid crystal layer 14 that is sandwiched by the first laminate body 12 and second laminate body 13; and a seal material 25 that is provided between the first laminate body 12 and second laminate body 13, and encapsulates a liquid crystal material of the liquid crystal layer 14. The first laminate body 12 and the second laminate body 13 have: a first base material 21A and a second material 21B, respectively, each of which is made of a transparent film; and a first transparent electrode 22A and a second transparent electrode 22B that are formed in the respective base materials. Transmittance light is controlled by actuating these electrodes. An area of the liquid crystal cell 10 in a plan view is equal to or greater than 480000 mm2. In the seal material 25, 90-degree peeling adhesion strength is equal to or greater than 0.3 N / 10 mm, and shear strength is equal to or greater than 0.5 mm2, with respect to the first laminate body 12 and second laminate body 13 under an environment of 100°C.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] TECHNICAL FIELD The embodiments of the present disclosure relate to a liquid crystal cell and a liquid crystal device. [Background technology]

[0002] Conventionally, liquid crystal devices such as dimming elements using liquid crystals and dimming devices using such dimming elements have been proposed, which can be used in combination with light-transmitting elements such as windows and the like to control the transmission of external light, and which can be used in electronic blinds and the like to control the transmission of external light (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 198748 Summary of the Invention [Problem to be solved by the invention]

[0004] Such a liquid crystal device has a configuration including a pair of glass plates, a liquid crystal cell disposed between the glass plates, and a bonding layer provided between each glass plate and the liquid crystal cell.

[0005] However, if the completed liquid crystal device is exposed to a high-temperature environment, the liquid crystal material sealed in the liquid crystal cell may leak out of the liquid crystal cell or seep onto the adhesive surface of the sealing material (hereinafter referred to as "liquid crystal material seepage"). When the liquid crystal device is exposed to a high-temperature environment, the bonding layer expands due to the high temperature. This causes the liquid crystal cell to be compressed, causing the liquid crystal material to flow and compress the sealing material. If the adhesive strength of the sealing material is insufficient at this time, the sealing material may peel off or break, resulting in the above-mentioned seepage of the liquid crystal material. Seepage of the liquid crystal material is undesirable because it degrades the performance of the liquid crystal cell and also mars the appearance of the liquid crystal device.

[0006] An object of the embodiments of the present disclosure is to provide a liquid crystal cell and a liquid crystal device that can suppress exudation of liquid crystal material even when the liquid crystal device is exposed to a high-temperature environment. [Means for solving the problem]

[0007] The embodiments of the present disclosure solve the above-mentioned problems by the following solutions. Note that, for ease of understanding, the following description will be given with reference numerals corresponding to the embodiments of the present disclosure, but the present disclosure is not limited to these. The first disclosed embodiment is a liquid crystal cell comprising a first laminate (12), a second laminate (13), a liquid crystal layer (14) sandwiched between the first laminate and the second laminate, and a sealant (25) provided between the first laminate and the second laminate and sealing the liquid crystal material of the liquid crystal layer, the first laminate and the second laminate having substrates (21A, 21B) made of transparent films and electrodes (22A, 22B) formed on the substrates, and controlling transmitted light by driving the electrodes, the liquid crystal cell having an area of ​​480,000 mm in a plan view. 2 or more, and the sealing material has a 90-degree peel adhesive strength of 0.3 N / 10 mm or more and a shear strength of 0.5 N / mm or more with respect to the first laminate and the second laminate in a 100°C environment. 2 This is the liquid crystal cell (10). The second disclosed embodiment is a liquid crystal cell (10) of the first disclosed embodiment, which has a rectangular shape in plan view and a short side of 480 mm or more. A third disclosed embodiment is a liquid crystal device (1) comprising a liquid crystal cell (10) of the first or second disclosed embodiment, a first transparent substrate (41) located on one side of the liquid crystal cell, a second transparent substrate (42) located on the other side of the liquid crystal cell, a first bonding layer (31) arranged between the first transparent substrate and the liquid crystal cell, and a second bonding layer (32) arranged between the second transparent substrate and the liquid crystal cell, wherein the first bonding layer and the second bonding layer do not include a bonding body containing a pressure-bondable adhesive component. A fourth disclosed embodiment is a liquid crystal device (1) in which, in the liquid crystal device of the third disclosed embodiment, the first bonding layer (31) is OCR and the second bonding layer (32) is OCR or OCA. [Effects of the Invention]

[0008] According to the embodiments of the present disclosure, it is possible to provide a liquid crystal cell and a liquid crystal device that can suppress the exudation of the liquid crystal material even when the liquid crystal device is exposed to a high-temperature environment. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an exploded perspective view showing the configuration of a liquid crystal device 1 according to an embodiment of the present disclosure. [Figure 2] 1 is a cross-sectional view showing a layer structure of a liquid crystal device 1 (laminated glass) according to an embodiment of the present disclosure. [Figure 3] 6 is a diagram illustrating a method for producing a test piece 60 for the 90-degree peel adhesive strength of a sealing material 25. FIG. [Figure 4] 10 is a diagram illustrating a method for measuring the 90-degree peel adhesive strength of the sealing material 25. FIG. [Figure 5] 10 is a diagram illustrating a method for producing a test piece 70 for measuring the shear strength of the sealing material 25. FIG. [Figure 6] 10 is a diagram illustrating a method for measuring the shear strength of a sealing material 25. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, etc. Note that the drawings shown below, including Fig. 1, are schematic diagrams, and the size and shape of each part are appropriately exaggerated to facilitate understanding. In the following description, specific numerical values, shapes, materials, etc. are given, but these can be changed as appropriate. The specific numerical values ​​specified in the specification and claims should be treated as including a general error range. In other words, a difference of about ±10% is not substantially different, and values ​​set within a range slightly exceeding the numerical range of the present invention should be interpreted as being substantially within the scope of the present invention.

[0011] In this specification, terms specifying shapes or geometric conditions, such as parallel and orthogonal, are intended to include not only their strict meanings but also states that perform similar optical functions and have an error that can be considered as parallel or orthogonal. In this specification, the term "transparent" refers to a material that transmits at least light of the wavelength to be used. For example, even if a material does not transmit visible light, if it transmits infrared light, it will be treated as transparent when used in infrared applications.

[0012] In this specification, the terms plate, sheet, film, etc. are used, but in general, these are used in order of thickness, that is, plate, sheet, film, and so on, and this specification follows suit. However, since there is no technical significance in this distinction, these terms can be used interchangeably as appropriate. In this specification, the sheet surface refers to the surface of each sheet that is in the planar direction of the sheet when viewed as a whole. The same applies to the plate surface and film surface. In this specification and claims, unless otherwise specified, a plan view refers to a state in which the liquid crystal device is viewed from a direction perpendicular to the main surface thereof.

[0013] (Embodiment) FIG. 1 is an exploded perspective view showing the configuration of a liquid crystal device 1 according to an embodiment of the present disclosure. The liquid crystal device 1 can be applied to various technical fields that require adjustment of light transmittance, and the range of application is not particularly limited. The liquid crystal device 1 is disposed in a portion where light control is required, such as window glass of a building, a showcase, a transparent partition inside a vehicle (for example, a front, side, rear, or roof window), or a partition board inside a vehicle. This makes it possible to control the amount of light incident on the inside of a building, a vehicle, etc., or to control the amount of light incident on a predetermined area inside a building, a vehicle, etc.

[0014] The liquid crystal device 1 according to the embodiment of the present disclosure will be described by taking an example in which the surface shape is planar (i.e., flat plate-like). However, the liquid crystal device 1 is not limited to this, and the surface shape may be a three-dimensional shape having a curved shape, for example, the liquid crystal device 1 may have a shape that is convex on one side.

[0015] 1, a liquid crystal device (laminated glass) 1 according to an embodiment of the present disclosure includes a first glass plate 41, a first bonding layer 31, a liquid crystal cell 10, a second bonding layer 32, and a second glass plate 42. In the thickness direction of the liquid crystal device 1, the first glass plate 41, the first bonding layer 31, the liquid crystal cell 10, the second bonding layer 32, and the second glass plate 42 are stacked in this order.

[0016] FIG. 2 is a cross-sectional view showing the layer structure of the liquid crystal device 1 (laminated glass) according to an embodiment of the present disclosure. As shown in FIG. 2, the liquid crystal device 1 includes a first glass plate 41, a second glass plate 42, and a liquid crystal cell 10 disposed between the first glass plate 41 and the second glass plate 42. The liquid crystal cell 10 comprises a first laminate 12 including a first substrate 21A, a first transparent electrode 22A, and a first alignment layer 23A, a second laminate 13 including a second substrate 21B, a second transparent electrode 22B, and a second alignment layer 23B, and a liquid crystal layer 14 disposed between the first laminate 12 and the second laminate 13.

[0017] The first glass plate (first transparent substrate) 41 and the second glass plate (second transparent substrate) 42 are disposed on the front and rear surfaces of the liquid crystal device 1, respectively, and are plate glasses having high light transmittance. In an embodiment of the present disclosure, the first glass plate 41 and the second glass plate 42 have a thickness of 0.5 mm or more and 4 mm or less, and as an example, each is made of a 2 mm thick plate glass. When inorganic glass is used as the first glass plate 41 and the second glass plate 42, the liquid crystal device 1 can be made to have excellent heat resistance and scratch resistance. The first glass plate 41 and the second glass plate 42 may be subjected to a surface treatment such as a hard coat, as necessary.

[0018] It should be noted that transparent resin plates (so-called resin glass) may be used instead of inorganic glass for the first glass plate (first transparent substrate) 41 and the second glass plate (second transparent substrate) 42. For example, polycarbonate, acrylic, etc. may be used as the transparent resin plates used for the first transparent substrate and the second transparent substrate. When transparent resin plates are used for the first transparent substrate and the second transparent substrate, the liquid crystal device 1 can be made lighter.

[0019] The first bonding layer 31 is disposed between the first glass plate 41 and the liquid crystal cell 10, and is a member that bonds the first glass plate 41 and the liquid crystal cell 10 to each other. The first bonding layer 31 is larger in size in a planar view than the liquid crystal cell 10. However, the first bonding layer 31 may be the same size as the first glass plate 41 and the second glass plate 42 in a planar view, or may be larger than the liquid crystal cell 10 and smaller than the first glass plate 41 and the second glass plate 42.

[0020] 2, the first bonding layer 31 is formed not only in the region covering the liquid crystal cell 10 but also in the portion corresponding to the periphery of the liquid crystal cell 10, and in this portion the first bonding layer 31 is connected to the second bonding layer 32. By forming the first bonding layer 31 in this form, the side surface of the liquid crystal cell 10 or a portion thereof is prevented from being exposed to the side surface of the liquid crystal device 1, and the intrusion of moisture and the like from the side surface of the liquid crystal device 1 is suppressed, thereby further improving the water-tightness of the liquid crystal device 1.

[0021] In the embodiment of the present disclosure, the first bonding layer 31 is made 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 a liquid resin obtained by mixing a base resin such as an acrylic resin, a silicone resin, or a urethane resin with an additive, which is applied to an object and then cured using, for example, ultraviolet (UV) light. The first bonding layer 31 has optical transparency, and preferably has heat resistance up to at least about 120° C., moist heat resistance, and weather resistance. The thickness of first bonding layer 31 may be selected appropriately depending on the material thereof, etc. Specifically, the thickness of first bonding layer 31 in the region overlapping with liquid crystal cell 10 in plan view can be set to 30 μm or more and 1000 μm or less.

[0022] The second bonding layer 32 is disposed between the second glass plate 42 and the liquid crystal cell 10, and is a member that bonds the second glass plate 42 and the liquid crystal cell 10 to each other. The second bonding layer 32 is larger in size in a planar view than the liquid crystal cell 10. However, the second bonding layer 32 may be the same size as the first glass plate 41 and the second glass plate 42 in a planar view, or may be larger than the liquid crystal cell 10 and smaller than the first glass plate 41 and the second glass plate 42.

[0023] In the embodiment of the present disclosure, the second bonding layer 32 is made 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 then cured using ultraviolet (UV) light to obtain an OCA sheet. The curable adhesive layer composition may be an optical pressure-sensitive adhesive such as an acrylic resin, silicone resin, or urethane resin. After this OCA sheet is attached to an object, the release film is peeled off and removed to obtain a layer made of the OCA.

[0024] The second bonding layer 32 made of OCA has optical transparency, and preferably has heat resistance, moist heat resistance, and weather resistance up to at least about 120°C. In the embodiments of the present disclosure, the second bonding layer 32 is described as being made of OCA, but this is not limiting, and the second bonding layer 32 may be made of OCR like the first bonding layer 31, or both the first bonding layer 31 and the second bonding layer 32 may be made of OCA. Furthermore, one of the first bonding layer and the second bonding layer 32 may be made of OCA or OCR and the other may be made of PVB (polyvinyl butyral), or both may be made of PVB. The thickness of second bonding layer 32 may be selected appropriately depending on the material, etc. Specifically, the thickness of second bonding layer 32 may be 30 μm or more and 500 μm or less, and is preferably 50 μm or more and 200 μm or less.

[0025] In the embodiment of the present disclosure, the first bonding layer 31 directly bonds the first glass plate 41 and the liquid crystal cell 10, and the second bonding layer 32 directly bonds the second glass plate 42 and the liquid crystal cell 10. However, this is not limiting, and a film such as an ultraviolet (UV) cut film may be interposed at least in one location between the first glass plate 41 and the liquid crystal cell 10 and between the second glass plate 42 and the liquid crystal cell 10.

[0026] As described above, the first bonding layer 31 and the second bonding layer 32 are bonded bodies containing a non-compression adhesive component. Here, the term "bonded body containing a non-compression adhesive component" refers to a bonded body that does not require pressure to be properly bonded to an adjacent object and that can be moderately bonded to an adjacent object under normal pressure.

[0027] In the embodiment of the present disclosure, the first bonding layer 31 is a layer formed from OCR, and therefore the first glass plate 41 can be bonded to the liquid crystal cell 10 without being pressurized by the first bonding layer 31 (i.e., under environmental pressure (usually atmospheric pressure)). Furthermore, the first glass plate 41 can be bonded to the liquid crystal cell 10 at room temperature (e.g., 10°C or higher and 30°C or lower) by the first bonding layer 31. Similarly, the second bonding layer 32 is a layer formed from OCA, and therefore the second glass plate 42 can be bonded to the liquid crystal cell 10 without being pressurized by the second bonding layer 32 (i.e., under environmental pressure (usually atmospheric pressure)). Furthermore, the second glass plate 42 can be bonded to the liquid crystal cell 10 at room temperature (e.g., 10°C or higher and 30°C or lower) by the second bonding layer 32.

[0028] The liquid crystal device 1 may use an adhesive containing a pressure-bonding adhesive component as the bonding layer. An example of an adhesive containing a pressure-bonding adhesive component is an interlayer made of PVB (polyvinyl butyral). The term "an adhesive containing a pressure-bonding adhesive component" refers to an adhesive that requires pressure (i.e., pressure greater than normal pressure) to properly bond to an adjacent object. Normal pressure is environmental pressure, and is usually equal to atmospheric pressure, and may be referred to as standard atmospheric pressure. Although a bonded structure containing a pressure-bondable adhesive component, such as an interlayer made of PVB or the like, can be used as first bonding layer 31 and second bonding layer 32 in the embodiments of the present disclosure, this interlayer may soften in a high-temperature environment, causing liquid crystal accumulation. From this perspective, it is preferable to form first bonding layer 31 and second bonding layer 32 using OCA or OCR, which are the aforementioned "bonded structures containing a non-pressure-bondable adhesive component."

[0029] The liquid crystal cell 10 (light control film, liquid crystal film) is a film that can control the amount of transmitted light by changing the applied voltage. The liquid crystal cell 10 is disposed so as to be sandwiched between a first glass plate 41 and a second glass plate 42. This liquid crystal cell 10 has a guest-host type liquid crystal layer using a dichroic dye, and is a component that changes the amount of light transmitted by an electric field applied to the liquid crystal. The liquid crystal cell 10 includes a first film-like laminate 12, a second film-like laminate 13, and a liquid crystal layer 14 disposed between the first laminate 12 and the second laminate 13.

[0030] As shown in Figure 2, the first laminate 12 comprises a first substrate 21A, a first transparent electrode 22A, and a first alignment layer 23A, and is stacked in the order of first substrate 21A, first transparent electrode 22A, and first alignment layer 23A from the first bonding layer 31 side. The second laminate 13 also includes a second substrate 21B, a second transparent electrode 22B, and a second alignment layer 23B, which are stacked in the order of second substrate 21B, second transparent electrode 22B, and second alignment layer 23B from the second bonding layer 32 side.

[0031] Furthermore, a plurality of bead spacers 24 are disposed between the first laminate 12 and the second laminate 13. The liquid crystal layer 14 is disposed between the first laminate 12 and the second laminate 13 by filling liquid crystal between the plurality of bead spacers 24. The plurality of bead spacers 24 may be disposed irregularly or regularly.

[0032] The liquid crystal cell 10 changes the orientation of the liquid crystal material made of a guest-host liquid crystal composition in the liquid crystal layer 14 by driving the first transparent electrode 22A and the second transparent electrode 22B provided in the first laminate 12 and the second laminate 13, thereby changing the amount of transmitted light.

[0033] The first substrate 21A and the second substrate 21B are made of a transparent resin, and a flexible film can be used. As the first substrate 21A and the second substrate 21B, it is desirable to use a transparent resin film that has small optical anisotropy and a transmittance of 80% or more for wavelengths in the visible range (380 nm or more and 800 nm or less). Examples of materials for such transparent resin films 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, polyetherketone (PEK), (meth)acrylonitrile, cycloolefin polymer (COP), and cycloolefin copolymer. Resins such as polycarbonate, cycloolefin polymer, and polyethylene terephthalate are particularly preferred as materials for transparent resin films.

[0034] The thickness of the transparent resin films used as the first substrate 21A and the second substrate 21B may vary depending on the material, but may be selected appropriately within the range in which the transparent resin films are flexible. The thickness of each of the first substrate 21A and the second substrate 21B may be 50 μm or more and 200 μm or less. In the embodiment of the present disclosure, a polyethylene terephthalate film having a thickness of 125 μm is used as an example of the first base material 21A and the second base material 21B.

[0035] The first transparent electrode 22A and the second transparent electrode 22B are composed of transparent conductive films laminated on the first substrate 21A and the second substrate 21B (transparent resin films), respectively. As the transparent conductive film, various transparent electrode materials applicable to this type of transparent resin film can be used, including oxide-based transparent metal thin films with a total light transmittance of 50% or more, such as tin oxide-based, indium oxide-based, and zinc oxide-based.

[0036] Tin oxide (SnO2) based materials include NESA (tin oxide SnO2), ATO (antimony tin oxide), and FTO (fluorine-doped tin oxide). Indium oxide (In2O3) based materials include indium oxide, ITO (indium tin oxide), and IZO (indium zinc oxide). Zinc oxide (ZnO) based materials include zinc oxide, AZO (aluminum-doped zinc oxide), and GZO (gallium-doped zinc oxide). In the embodiment of the present disclosure, the transparent conductive films constituting the first transparent electrode 22A and the second transparent electrode 22B are formed of ITO.

[0037] The bead spacers 24 are members that define the thickness (cell gap) of the liquid crystal layer 14 excluding the outer periphery. In the embodiment of the present disclosure, spherical bead spacers are used as the bead spacers 24. The diameter of the bead spacers 24 may be 1 μm or more and 20 μm or less, and preferably 3 μm or more and 15 μm or less. The bead spacers 24 can be made of a wide range of materials, including inorganic materials such as silica, organic materials, and core-shell structures that combine these materials. In addition to the spherical shape, the bead spacers may be configured in rod shapes such as cylindrical, elliptical, polygonal, etc. Furthermore, although the bead spacers 24 are manufactured from a transparent material, a colored material may be applied as necessary to adjust the color.

[0038] In the embodiment of the present disclosure, the bead spacers 24 are provided on the second laminate 13, but this is not limited thereto, and they may be provided on both the first laminate 12 and the second laminate 13, or only on the first laminate 12. Also, the bead spacers 24 do not necessarily have to be provided. Also, instead of or together with the bead spacers 24, columnar spacers may be used.

[0039] The first alignment layer 23A and the second alignment layer 23B are members for aligning the liquid crystal molecules contained in the liquid crystal layer 14 in a desired direction. The first alignment layer 23A and the second alignment layer 23B are formed by a photo-alignment layer. As a photo-alignment material applicable to the photo-alignment layer, a wide variety of materials to which a photo-alignment technique can be applied can be used, and examples thereof include photodecomposition type, photodimerization type, and photoisomerization type. In an embodiment of the present disclosure, a photodimerization type material is used. Examples of the photodimerization type material include polymers having cinnamate, coumarin, benzylidenephthalimidine, benzylideneacetophenone, diphenylacetylene, stilbazole, uracil, quinolinone, maleimide, or a cinnamylideneacetic acid derivative. As the photodimerization type material, a polymer having one or both of cinnamate and coumarin is preferably used, in particular because of its excellent alignment control force.

[0040] Instead of the photo-alignment layer, a rubbed alignment layer may be used. The rubbed alignment layer may not be subjected to a rubbing treatment, or may be prepared by subjecting the layer to a rubbing treatment followed by a shaping treatment to form fine line-shaped irregularities. In the embodiment of the present disclosure, the liquid crystal cell 10 includes the first alignment layer 23A and the second alignment layer 23B, but is not limited to this, and may have a configuration that does not include the first alignment layer 23A and the second alignment layer 23B.

[0041] A wide variety of guest-host liquid crystal compositions and dichroic dye compositions can be used to form the liquid crystal layer 14. The guest-host liquid crystal composition may contain a chiral agent so that when the liquid crystal material is horizontally aligned, it is oriented in a helical shape in the thickness direction of the liquid crystal layer 14. In addition, a sealant 25 having a ring or frame shape in plan view is disposed between the first laminate 12 and the second laminate 13 so as to surround the liquid crystal layer 14. The sealant 25 bonds and holds the first laminate 12 and the second laminate 13 together, preventing leakage of the liquid crystal material. The sealing material 25 may be a thermosetting resin such as an epoxy resin or an acrylic resin, or an ultraviolet curable resin. The sealing material 25 can have a width of 3 to 5 mm and a thickness of 25 to 30 μm.

[0042] It is preferable that the sealing material 25 has a sufficiently high adhesive strength to the first laminate 12 and the second laminate 13 in a high-temperature (100°C) environment. Specifically, the 90-degree peel adhesive strength (so-called T-peel adhesive strength) of the sealing material 25 to the first laminate 12 and the second laminate 13 in a high-temperature (100°C) environment is 0.3 N / 10 mm or more, and the shear strength of the sealing material 25 to the first laminate 12 and the second laminate 13 in a high-temperature (100°C) environment is 0.5 N / mm or more. 2 It is preferable that the adhesive strength of the sealant 25 to the first laminate 12 and the second laminate 13 is equal to or greater than the above. When the liquid crystal device 1 is exposed to a high temperature environment, the sealant may peel off or break, and the liquid crystal material may be prevented from seeping out. Such seepage of the liquid crystal material tends to occur more easily as the area of ​​the liquid crystal cell 10 in plan view increases, and in particular, when the area of ​​the liquid crystal cell 10 in plan view is 480,000 mm 2 In the above cases, it is particularly effective from the viewpoint of suppressing the seepage of the liquid crystal material that the sealant 25 has the above adhesive strength. Note that the area of ​​the liquid crystal cell 10 in a planar view refers to the area of ​​the entire liquid crystal cell 10 in a planar view, i.e., the area of ​​the outer shape of the liquid crystal cell 10, and not the area of ​​the liquid crystal layer 14 located inside the sealing material 25 in a planar view. The methods for measuring the 90-degree peel adhesive strength (T-peel adhesive strength) and shear strength of the sealing material 25 will be described in detail later.

[0043] For the liquid crystal layer 14, a nematic liquid crystal compound, a smectic liquid crystal compound, or a cholesteric liquid crystal compound can be used as a liquid crystal compound having no polymerizable functional group. Examples of nematic liquid crystal compounds include biphenyl-based compounds, terphenyl-based compounds, phenylcyclohexyl-based compounds, biphenylcyclohexyl-based compounds, phenylbicyclohexyl-based compounds, trifluoro-based compounds, phenyl benzoate-based compounds, phenyl cyclohexylbenzoate-based compounds, phenyl phenylbenzoate-based compounds, phenyl bicyclohexylcarboxylate-based compounds, azomethine-based compounds, azo-based compounds, azooxy-based compounds, stilbene-based compounds, tolan-based compounds, ester-based compounds, bicyclohexyl-based compounds, phenylpyrimidine-based compounds, biphenylpyrimidine-based compounds, pyrimidine-based compounds, and biphenylethyne-based compounds.

[0044] Examples of smectic liquid crystal compounds include ferroelectric polymer liquid crystal compounds such as polyacrylates, polymethacrylates, polychloroacrylates, polyoxiranes, polysiloxanes, and polyesters. Examples of the cholesteric liquid crystal compound include cholesteryl linoleate, cholesteryl oleate, cellulose, cellulose derivatives, and polypeptides.

[0045] Examples of dichroic dyes used in the guest-host system include dyes that are soluble in liquid crystal and have high dichroic properties, such as azo-based, anthraquinone-based, quinophthalone-based, perylene-based, indigo-based, thioindigo-based, merocyanine-based, styryl-based, azomethine-based, and tetrazine-based dichroic dyes.

[0046] The liquid crystal cell 10 is configured as a normally dark cell, with the first alignment layer 23A and the second alignment layer 23B configured as horizontal alignment layers with a pretilt force set in a certain direction so that the guest-host liquid crystal composition is aligned in a light-blocking state when no electric field is applied. The liquid crystal cell 10 may also be configured as a normally clear cell, which is aligned in a light-blocking state when an electric field is applied. Normally dark is a structure in which the transmittance is at its minimum when no voltage is applied to the liquid crystal, resulting in a light-blocking state, whereas normally clear is a structure in which the transmittance is at its maximum when no voltage is applied to the liquid crystal, resulting in a light-transmitting state.

[0047] Furthermore, since it is desirable that the scenery or the like seen through the liquid crystal cell 10 in the light-transmitting state be clearly visible, it is desirable that the haze value in the light-transmitting state be low. Specifically, the haze value of the liquid crystal cell 10 in the light-transmitting state is desirably 30% or less, and more desirably 15% or less. To achieve such a low haze value, it is desirable that the liquid crystal mixture does not contain a polymerizable compound.

[0048] Although the liquid crystal cell 10 according to the embodiment of the present disclosure includes a guest-host liquid crystal layer 14, the present invention is not limited to this. The liquid crystal cell 10 may also include a liquid crystal layer 14 of a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, an IPS (In-Plane-Switching) mode, or the like that does not use a dichroic dye composition. When including such a liquid crystal layer 14, the liquid crystal cell 10 can function as a light control film by further providing a linear polarization layer on each of the surfaces of the first substrate 21A and the second substrate 21B.

[0049] As shown in FIG. 1, the liquid crystal cell 10 is provided with a flexible printed wiring board 18 for electrically connecting the first transparent electrode 22A and the second transparent electrode 22B to the outside. The flexible printed wiring board 18 can be connected by being sandwiched between the first transparent electrode 22A and the second transparent electrode 22B, for example, in a region where the first transparent electrode 22A and the second transparent electrode 22B do not sandwich the liquid crystal layer 14. Note that the flexible printed wiring board 18 may also be in a form where it is not sandwiched between the first transparent electrode 22A and the second transparent electrode 22B, for example.

[0050] (Regarding the adhesive strength of sealant 25) The following describes the preferred ranges of the 90-degree peel adhesive strength (T-peel adhesive strength) and shear strength of the sealing material 25 in a high-temperature (100° C.) environment. The sealing material 25 has a 90-degree peel adhesive strength (T-type peel adhesive strength) of 0.3 N / 10 mm or more in a 100°C environment, and a shear strength of 0.5 N / mm 2 This is preferable from the viewpoint of suppressing the exudation of the liquid crystal material due to breakage of the sealant 25 and peeling from the first laminate 12 and the second laminate 13 in a high temperature environment.

[0051] When the liquid crystal device 1 is exposed to a high-temperature environment, the OCR material of the second bonding layer 32 expands. Because the liquid crystal cell 10 is sandwiched between the first glass plate 41 and the second glass plate 42, the expansion of the OCR material pressurizes the liquid crystal cell 10. This causes the liquid crystal material to flow toward the outer edge of the liquid crystal layer 14 (toward the sealant 25), exerting strong pressure on the adhesive surfaces between the sealant 25 and the first laminate 12 and the second laminate 13. If the adhesive strength of the sealant 25 to the first laminate 12 and the second laminate 13 is insufficient, the sealant 25 may peel or break, causing the liquid crystal material to seep out of the adhesive surfaces between the sealant 25 and the first laminate 12 or the second laminate 13 and out of the liquid crystal cell 10. This type of liquid crystal material seepage is likely to occur when the liquid crystal cell 10 has a large planar area, which is undesirable because it can degrade the optical performance and appearance of the liquid crystal device 1.

[0052] Therefore, in particular, when the area of ​​the liquid crystal cell 10 in plan view is 480000 mm 2 When the adhesive strength of the sealing material 25 to the first laminate 12 and the second laminate 13 in a high temperature (100°C) environment exceeds 0.3 N / 10 mm or more in 90-degree peel adhesive strength and 0.5 N / mm or more in shear strength, 2 is preferable from the viewpoint of suppressing the exudation of the liquid crystal material.

[0053] As described above, in the embodiment of the present disclosure, in the liquid crystal cell 10, the sealant 25 bonds the first laminate 12 and the second laminate 13 together to seal the liquid crystal material of the liquid crystal layer 14. In the first laminate 12, a first transparent electrode 22A and a first alignment layer 23A are provided on the surface of the first substrate 21A facing the liquid crystal layer 14, and in the second laminate 13, a second transparent electrode 22B and a second alignment layer 23B are provided on the surface of the second substrate 21B facing the liquid crystal layer 14. Therefore, in an embodiment of the present disclosure, the adhesive strength of the sealing material 25 to the first laminate 12 and the second laminate 13 corresponds to the adhesive strength between the sealing material 25 and the liquid crystal side surfaces of these laminates (surfaces on which the alignment layer and electrodes are laminated).

[0054] This section explains how to measure 90-degree peel adhesive strength and shear strength. FIG. 3 is a diagram illustrating a method for producing a test piece 60 for the 90-degree peel adhesive strength of the sealing material 25. FIG. 4 is a diagram illustrating a method for measuring the 90-degree peel adhesive strength of the sealing material 25. The test piece 60 used in the 90-degree peel adhesion strength test of the sealant 25 is prepared as follows. First, as shown in Fig. 3(a), the sealant 25 is applied in a frame shape onto the surface of the second laminate 13 facing the liquid crystal layer 14 (the surface on which the second transparent electrode 22B and the second alignment layer 23B are provided) using a nozzle (not shown). At this time, the sealant 25 is applied so as to have the same width and thickness as when the liquid crystal cell 10 was manufactured.

[0055] Next, as shown in FIG. 3(b), the first laminate 12 is laminated onto the second laminate 13 and the sealant 25 to form a laminate 60A, and the sealant 25 is cured. At this time, the first laminate 12 is laminated so that the surface of the first laminate 12 facing the liquid crystal layer 14 (the surface on which the first transparent electrode 22A and the first alignment layer 23A are provided) faces the sealant 25 and second laminate 13. When viewed from the thickness direction of the laminate 60A, as shown in FIG. 3(c), the first laminate 12 is laminated over the entire surface of the second laminate 13. Next, as shown in FIG. 3(c), a test piece 60 is cut out from the laminate 60A so as to have a size and a position of the sealing material 25 corresponding to a test piece for measuring 90-degree peel adhesive strength.

[0056] As shown in Fig. 3(d), the test piece 60 has a rectangular shape in plan view. In plan view, the sealing material 25 of the test piece 60 extends parallel to the short side direction near one end of the long side direction of the test piece 60. In this case, the dimension D11 of the short side of the test piece 60 is 10 mm, and the dimension D12 from the sealing material 25 to the other short side along the long side direction of the test piece 60 is 15 mm. The width of the sealing material 25 is 3 to 5 mm, and the thickness of the sealing material 25 is 25 to 30 µm. Next, at a position D13=8 mm along the long side from the position of the sealing material 25 of this test piece 60 toward the other short side (a position D14=7 mm from the open short side), as shown in Figure 3(e), the first laminate 12 is folded upward by 90 degrees and the second laminate 13 is folded downward by 90 degrees. Using the test piece 60 in this state, the 90-degree peel adhesion strength is measured.

[0057] The 90-degree peel strength was measured as follows. First, as shown in Fig. 4, the end portions of the test piece 60 on the non-bonded side of each laminate, i.e., the side bent 90 degrees, are held by jigs 81A and 81B. The dimension D15 between the jigs 81A and 81B is 5 to 10 mm. Next, the jigs 81A and 81B are pulled in opposite directions (for example, as shown in FIG. 4, in the vertical direction with the first laminate 12 on top and the second laminate 13 on the bottom) at a speed of 10 mm / min, and the strength at which the sealing material 25 breaks is measured. This measurement was carried out using an Instron 5565 (manufactured by Instron Corporation), a tensile testing machine, with the test piece 60 and the like placed in a thermostatic chamber and the temperature of the thermostatic chamber raised to 100°C.

[0058] FIG. 5 is a diagram illustrating a method for producing a test piece 70 for measuring the shear strength of the sealing material 25. As shown in FIG. FIG. 6 is a diagram illustrating a method for measuring the shear strength of the sealing material 25. As shown in FIG. The test piece 70 used in the shear strength test of the sealing material 25 is prepared as follows. First, as shown in Fig. 5(a), the sealing material 25 is applied in a line parallel to one side (near the left side in Fig. 5(a)) of the surface of the second laminate 13 that faces the liquid crystal layer 14 (the surface on which the second transparent electrode 22B and the second alignment layer 23B are provided) using a nozzle (not shown) or the like. At this time, the sealing material 25 is applied so as to have the same width and thickness as when the liquid crystal cell 10 was manufactured.

[0059] Next, as shown in FIG. 5(b), the end of the other side of the first stack 12 (in FIG. 5(b), the end of the right side of the first stack 12) is placed on the end of the second stack 13 on which the sealant 25 is provided, and they are laminated together to form a stack 70A, and the sealant 25 is cured. At this time, the first stack 12 is laminated so that its surface on the liquid crystal layer 14 side (the surface on which the first transparent electrode 22A and the first alignment layer 23A are provided) faces the sealant 25 and the second stack 13. Also, as shown in FIG. 5(c), the first stack 12 and the second stack 13 are not laminated in a plan view except for a stacked region 71 that sandwiches the sealant 25, and the sealant 25 is located in the center of the stacked region 71 where the first stack 12 and the second stack 13 are laminated.

[0060] Thereafter, as shown in FIG. 5(c), a test piece 70 is cut out from the laminate 70A so as to have a size and a position of the sealing material corresponding to a test piece for measuring shear strength. As shown in Fig. 5(d), the test piece 70 has a rectangular shape in a plan view. The dimension D21 of the short side of the test piece 70 is 10 mm, and the dimension D22 from one end to the sealing material 25 in the long side direction of each laminate is 15 mm. The sealing material 25 is located at the center of the long side direction of the test piece 70 and is provided so as to extend parallel to the short side direction of the test piece 70. The width of the sealing material 25 is 3 to 5 mm, and the thickness of the sealing material 25 is 25 to 30 µm.

[0061] The shear strength was measured as follows. 6, both ends in the long side direction of the test piece 70 (the end of the first laminate 12 and the end of the second laminate 13) are held by jigs 81A and 81B. At this time, the dimension D23 between the jigs 81A and 81B is 15 to 20 mm. Next, the jigs 81A and 81B are pulled in opposite directions along the vertical direction (for example, first substrate 21A upward and second substrate 21B downward) at a speed of 10 mm / min, and the strength is measured when sealing material 25 breaks. This measurement was performed using an Instron 5565 (manufactured by Instron Corporation), a tensile tester, with test piece 60 and the like placed in a thermostatic chamber and the temperature of the thermostatic chamber raised to 100°C. The 90-degree peel strength and shear strength were each measured five times using five test pieces, and the average values ​​were used.

[0062] Several sealing materials 25 with different 90-degree peel adhesive strengths and shear strengths measured using the above-mentioned measurement method were prepared, and liquid crystal cells 10 and liquid crystal devices 1 of different sizes were fabricated using each sealing material 25, and the presence or absence of leakage of liquid crystal material due to peeling or damage of the sealing material 25 when the liquid crystal device 1 was exposed to a high-temperature environment was evaluated. The 90-degree peel adhesive strength and shear strength of the prepared sealing materials of Samples 1 to 5 are as follows. Sample 1: 90-degree peel strength is 0.0 N / 10 mm, shear strength is 0.2 N / mm 2 Sample 2: 90-degree peel strength is 0.0 N / 10 mm, shear strength is 0.4 N / mm 2 Sample 3: 90-degree peel strength is 0.3 N / 10 mm, shear strength is 0.5 N / mm 2 Sample 4: 90-degree peel strength is 0.3 N / 10 mm, shear strength is 0.7 N / mm 2 Sample 5: 90-degree peel strength is 0.4 N / 10 mm, shear strength is 1.7 N / mm 2

[0063] The liquid crystal cell 10 and the liquid crystal device 1 (laminated glass) have the following four sizes in plan view. Size 1: Liquid crystal cell 10 is 50mm x 50mm, liquid crystal device 1 is 60mm x 60mm Size 2: Liquid crystal cell 10 is 280mm x 280mm, liquid crystal device 1 is 300 x 300mm Size 3: Liquid crystal cell 10 is 280mm x 580mm, liquid crystal device 1 is 300mm x 600mm Size 4: Liquid crystal cell 10 is 480mm x 1000mm, liquid crystal device 1 is 500mm x 1020mm In any size, the thickness (cell gap) of the liquid crystal layer 14 is 12 μm.

[0064] Liquid crystal cells and liquid crystal devices of various sizes were prepared using each sample, and these were left standing in a high-temperature (85°C) environment (with the main surface of the liquid crystal device 1 arranged parallel to the vertical direction) for 60 minutes. Immediately after being removed from the high-temperature environment, each liquid crystal device was visually inspected to check for exudation of the liquid crystal material due to peeling or damage of the sealant 25.

[0065] [Table 1]

[0066] [Table 2]

[0067] [Table 3]

[0068] [Table 4]

[0069] [Table 5]

[0070] Table 1 shows whether or not the liquid crystal material seeped out of the sealant 25 of Sample 1. Table 2 shows whether or not the liquid crystal material seeped out of the sealant 25 of Sample 2. Table 3 shows whether or not the liquid crystal material seeped out of the sealant 25 of Sample 3. Table 4 shows whether or not the liquid crystal material seeped out of the sealant 25 of Sample 4. Table 5 shows whether or not the liquid crystal material seeped out of the sealant 25 of Sample 5.

[0071] As shown in samples 7 and 8 in Table 2, when the liquid crystal device was placed upright, the side parallel to the vertical direction, whether it was the short side or the long side, had no effect on whether the liquid crystal material leaked out due to peeling or damage of the sealing material 25. In addition, as shown in Tables 1 and 2, samples 1 and 2 have a 90-degree peel strength of less than 0.3 N / 10 mm and a shear strength of 0.5 N / mm 2 Even when a sealant 25 having an adhesive strength below the preferred range was used, when the size of the liquid crystal cell 10 and the liquid crystal device 1 (laminated glass) was small (Samples 1 to 3, 5 to 8), no exudation of the liquid crystal material due to peeling or breakage of the sealant occurred. However, when the area of ​​the liquid crystal cell 10 was 480,000 mm 2 In the cases where the liquid crystal material was eluted (samples 4 and 9), the liquid crystal material oozed out.

[0072] As shown in Tables 3, 4, and 5, samples 3, 4, and 5 have a 90-degree peel strength of 0.3 N / 10 mm or more and a shear strength of 0.5 N / mm 2 When a sealant 25 having an adhesive strength satisfying the preferred range was used, even when the area of ​​the liquid crystal cell 10 was small (Samples 10 to 12, 14 to 16, and 18 to 20), the area of ​​the liquid crystal cell 10 was 480,000 mm 2 Even when the thickness was as large as 13, 17, and 21, no exudation of the liquid crystal material occurred.

[0073] A 480mm x 1000mm liquid crystal cell 10 was fabricated using the sealant of Sample 2, whose 90° peel strength and shear strength did not satisfy the preferred ranges, and bonded to a 500mm x 1020mm second glass plate 42 with the second bonding layer 32 (a layer made of OCA). This laminated member, i.e., a state in which the first bonding layer 31 and the first glass plate 41 were not laminated and thus not a laminated glass, was fabricated. Tests were also conducted to confirm whether exudation of the liquid crystal material occurred when the laminated member was placed upright in an 85°C environment for 60 minutes and when it was placed flat in an 85°C environment for 60 minutes (with the main surface of the liquid crystal device 1 parallel to the horizontal direction). In this laminated member, i.e., when the first bonding layer 31 and the first glass plate 41 were not laminated on one side of the liquid crystal cell 10, no exudation of the liquid crystal material due to peeling or breakage of the sealant 25 occurred. Therefore, it was confirmed that the seepage of the liquid crystal material due to breakage or peeling of the sealing material is a phenomenon that occurs when the laminated glass (liquid crystal device 1) is exposed to a high temperature environment.

[0074] From the above, according to the embodiment of the present disclosure, the 90-degree peel adhesive strength of the sealant 25 of the liquid crystal cell 10 in a 100° C. environment is 0.3 N / 10 mm or more, and the shear strength is 0.5 N / mm 2 By using the sealant 25 having the above structure, it is possible to prevent the liquid crystal material from leaking out due to peeling or breakage of the sealant 25 when the liquid crystal device 1 is exposed to a high temperature (85°C) environment. 2 This is particularly effective when the above conditions are met. Furthermore, according to the embodiment of the present disclosure, the liquid crystal cell 10 has an area of ​​480,000 mm in a plan view. 2 As described above, if the shape in plan view is rectangular and the dimension of the short side is 480 mm or more, the sealing material is likely to peel off or break and leak out of the liquid crystal material in a high-temperature environment; however, by satisfying the above conditions, the leaking of the liquid crystal material can be effectively suppressed.

[0075] (Variations) The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible, and these are also within the scope of the embodiments of the present disclosure.

[0076] (1) In the embodiments of the present disclosure, the liquid crystal device 1 and the liquid crystal cell 10 are described as being rectangular in plan view. However, the liquid crystal cell 10 may be, for example, a square, a parallelogram, a trapezoid, or the like in plan view, and the shape of the liquid crystal cell 10 in plan view can be changed as appropriate.

[0077] (2) In the embodiments of the present disclosure, the liquid crystal cell 10 has been described as a light-controlling cell that adjusts light transmittance. However, the present disclosure is not limited to this, and the liquid crystal cell 10 may also be used to display information, and the present disclosure can be suitably applied to a liquid crystal device including such a liquid crystal cell 10.

[0078] The embodiments and modifications may be used in combination as appropriate, but detailed description thereof will be omitted. The embodiments of the present disclosure are not limited to the above-described embodiments. [Explanation of symbols]

[0079] 1 Liquid crystal device 10 Liquid crystal cell 12 First laminate 13 Second laminate 14 Liquid crystal layer 18 Flexible printed wiring board 21A 1st base material 21B 2nd base material 22A 1st transparent electrode 22B 2nd transparent electrode 23A First alignment layer 23B Second alignment layer 24 Bead Spacer 25 Sealing material 31 1st bonding layer 32 Second bonding layer 41 First Glass Plate 42 Second glass pane

Claims

1. A first laminate; A second laminate; a liquid crystal layer sandwiched between the first stack and the second stack; a sealant provided between the first laminate and the second laminate, the sealant sealing the liquid crystal material of the liquid crystal layer; Equipped with the first laminate and the second laminate each have a substrate made of a transparent film and an electrode formed on the substrate; A liquid crystal cell that controls transmitted light by driving the electrodes, Planar area is 480,000 mm ２ That's all, The sealing material has a 90-degree peel adhesive strength of 0.3 N / 10 mm or more and a shear strength of 0.5 N / mm or more with respect to the first laminate and the second laminate in a 100°C environment. ２ That's all. Liquid crystal cell.

2. 2. The liquid crystal cell according to claim 1, The shape in plan view is rectangular, and the short side is 480 mm or more. Liquid crystal cell.

3. A liquid crystal cell according to claim 1 or 2; a first transparent substrate located on one side of the liquid crystal cell; a second transparent substrate located on the other side of the liquid crystal cell; 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 and the second bonding layer do not contain a bonding material containing a pressure-bonding adhesive component. Liquid crystal device.

4. 4. The liquid crystal device according to claim 3, the first bonding layer is an OCR; The second bonding layer is OCR or OCA; Liquid crystal device.

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