Light control sheet and method for manufacturing light control sheet

Abstract

This light control sheet comprises: a first electrode sheet provided with a first transparent electrode layer; a second electrode sheet provided with a second transparent electrode layer; a light control layer located between the first transparent electrode layer and the second transparent electrode layer; and a sealing material. The sealing material is disposed so as to cover an end surface of the light control layer at a boundary between a light control region in which the light control layer is sandwiched between the first electrode sheet and the second electrode sheet, and a non-light control region in which the first electrode sheet is exposed from the light control layer and the second electrode sheet, and so as to extend over the light control region and the non-light control region. The sealing material is provided with a valley part linearly extending along a first direction in which an edge part of the non-light control region extends, and is provided with a first mountain part and a second mountain part that are two outlines with the valley part as a boundary therebetween in a cross section orthogonal to the first direction. The first mountain part is located between the valley part and the edge part of the non-light control region. The second mountain part is located on the inner side of the light control sheet from the valley part and so as to extend over the light control region and the non-light control region.

Description

Light-adjusting sheet and method for manufacturing the same

[0001] The present disclosure relates to a light-controlling sheet and a method for manufacturing the light-controlling sheet.

[0002] The light-controlling sheet includes a pair of electrode sheets and a light-controlling layer located between the pair of electrode sheets. Each electrode sheet includes an insulating transparent substrate and a conductive transparent electrode layer. The light-controlling layer is located between the pair of transparent electrode layers.

[0003] The light-controlling layer, for example, contains a liquid crystal composition having liquid crystal molecules. The liquid crystal molecules exhibit different alignment states between a state where no potential difference is applied between a pair of transparent electrode layers and a state where a potential difference is applied between the pair of transparent electrode layers. The light-controlling sheet changes light transmittance depending on the alignment state of the liquid crystal molecules when a voltage is applied between the pair of transparent electrode layers.

[0004] The light-adjusting sheet includes a light-adjusting region where a light-adjusting layer is sandwiched between a pair of electrode sheets, and a non-light-adjusting region where one electrode sheet is exposed from the light-adjusting layer and the other electrode sheet. The non-light-adjusting region is arranged to surround the periphery of the light-adjusting region. A sealant is provided in the non-light-adjusting region to cover the light-adjusting layer located on the edge of the light-adjusting region (see, for example, Patent Document 1). The sealant prevents deterioration of the light-adjusting layer due to moisture in the air, etc.

[0005] Japanese Patent Application Laid-Open No. 2023-070962

[0006] In order to fully ensure the sealing material's ability to prevent deterioration of the light-controlling layer, it is necessary to ensure a sufficient thickness of the sealing material. On the other hand, simply increasing the amount of sealing material to ensure the function of preventing deterioration of the light-controlling layer makes it more likely that the sealing material will protrude beyond the outer edge of the light-controlling sheet, resulting in leakage.

[0007] In one aspect, a light-controlling sheet is provided, the light-controlling sheet comprising a first electrode sheet having a first transparent electrode layer, a second electrode sheet having a second transparent electrode layer, a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer, and a sealant, wherein a portion of the light-controlling layer sandwiched between the first electrode sheet and the second electrode sheet forms a light-controlling region, and a portion of the first electrode sheet exposed from the light-controlling layer and the second electrode sheet forms a non-light-controlling region, and the sealant covers an end face of the light-controlling layer at the boundary between the light-controlling region and the non-light-controlling region, and The sealing material is arranged so as to straddle the dimming area and the non-dimming area, the non-dimming area forms an edge extending in a first direction within the dimming sheet, the sealing material has a linear valley extending in the first direction, and in a cross section perpendicular to the first direction, has a first peak and a second peak which are two outlines bounded by the valley, the first peak being located between the valley and the edge of the non-dimming area, and the second peak being located inside the dimming sheet relative to the valley and straddling the dimming area and the non-dimming area.

[0008] In another aspect, a method for manufacturing a light-controlling sheet is provided, which includes the steps of forming a light-controlling region where the light-controlling layer is sandwiched between the first electrode sheet and the second electrode sheet and a non-light-controlling region where the first electrode sheet is exposed from the light-controlling layer and the second electrode sheet in a laminate including a first electrode sheet having a first transparent electrode layer, a second electrode sheet having a second transparent electrode layer, and a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer; and a step of placing a sealant to cover the end face, wherein the step of placing the sealant includes a step of applying an uncured first sealant to a portion of the first electrode sheet that will form the non-dimming region, a step of curing the first sealant after the step of applying the first sealant, a step of applying an uncured second sealant so as to overlap the first sealant and to straddle the dimming region and the non-dimming region, and a step of curing the second sealant after the step of applying the second sealant.

[0009] FIG. 1 is a plan view of a light-adjusting unit equipped with a light-adjusting sheet. FIG. 2 is a cross-sectional view of the light-adjusting sheet taken along line 2-2 in FIG. 1. FIG. 3 is a cross-sectional view of a laminate in which the layers that form the light-adjusting sheet are stacked during the manufacturing process of the light-adjusting sheet. FIG. 4 is a cross-sectional view of a light-adjusting sheet in a state in which a first sealing material is provided in the first non-light-adjusting region during the manufacturing process of the light-adjusting sheet. FIG. 5 is a cross-sectional view of a light-adjusting sheet in a state in which a second sealing material is provided on the first sealing material so as to straddle the light-adjusting region and the first non-light-adjusting region during the manufacturing process of the light-adjusting sheet. FIG. 6 is a cross-sectional view of a light-adjusting sheet in a state in which the sealing material is divided by burrs when the sealing material is applied at once so as to straddle the light-adjusting region and the first non-light-adjusting region. FIG. 7 is a table showing the sealing process conditions and evaluation results of a test example.

[0010] An embodiment of a light-adjusting sheet will be described below with reference to FIGS. 1 to 6. As shown in FIG. 1, a light-adjusting unit 10 includes a light-adjusting sheet 11, a first wiring section 12, and a second wiring section 13. The light-adjusting sheet 11 is a sheet-like member that changes light transmittance depending on whether or not a voltage is applied. The first wiring section 12 and the second wiring section 13 apply a voltage to the light-adjusting sheet 11. The first wiring section 12 and the second wiring section 13 are, for example, flexible printed circuits (FPCs). The first wiring section 12 and the second wiring section 13 are connected to an external power source (not shown) on the outside of the light-adjusting sheet 11.

[0011] [Layer structure of light-controlling sheet 11] As shown in Fig. 2, the light-controlling sheet 11 includes a first electrode sheet 20, a second electrode sheet 30, and a light-controlling layer 40. The first electrode sheet 20 includes a first transparent substrate 21 and a first transparent electrode layer 22. The second electrode sheet 30 includes a second transparent substrate 31 and a second transparent electrode layer 32. The light-controlling layer 40 is located between the first transparent electrode layer 22 and the second transparent electrode layer 32. In the light-controlling sheet 11, the first transparent substrate 21, the first transparent electrode layer 22, the light-controlling layer 40, the second transparent electrode layer 32, and the second transparent substrate 31 are stacked in this order in the stacking direction.

[0012] The first transparent substrate 21 and the second transparent substrate 31 are optically transparent, i.e., capable of transmitting visible light, and electrically insulating. The material forming the first transparent substrate 21 and the second transparent substrate 31 is an organic polymer compound or an inorganic polymer compound. The organic polymer compound is, for example, at least one selected from the group consisting of polyethylene terephthalate, polyester, polyacrylate, polycarbonate, and polyolefin. The inorganic polymer compound is, for example, at least one selected from the group consisting of silicon dioxide, silicon oxynitride, and silicon nitride. One example of the first transparent substrate 21 and the second transparent substrate 31 is polyethylene terephthalate. For example, the first transparent substrate 21 and the second transparent substrate 31 have a thickness of 50 μm or more and 130 μm or less.

[0013] The first transparent electrode layer 22 and the second transparent electrode layer 32 are optically transparent and electrically conductive, allowing the transmission of visible light. The material forming the first transparent electrode layer 22 and the second transparent electrode layer 32 is, for example, at least one selected from the group consisting of indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, and poly(3,4-ethylenedioxythiophene). The first transparent electrode layer 22 and the second transparent electrode layer 32 are, for example, indium tin oxide. For example, the first transparent electrode layer 22 and the second transparent electrode layer 32 have a thickness of approximately 0.1 μm.

[0014] The light-controlling layer 40 has different light transmittance depending on whether or not a voltage is applied across the first transparent electrode layer 22 and the second transparent electrode layer 32. In this embodiment, when no voltage is applied across the first transparent electrode layer 22 and the second transparent electrode layer 32, the light-controlling layer 40 exhibits an opaque state with low diffuse transmittance. When a voltage is applied across the first transparent electrode layer 22 and the second transparent electrode layer 32, the light-controlling layer 40 exhibits a transparent state with higher diffuse transmittance than in the opaque state. For example, the light-controlling layer 40 has a thickness of 5 μm or more and 30 μm or less.

[0015] An example of the light-controlling layer 40 includes a transparent organic polymer layer and a liquid crystal composition. The transparent organic polymer layer defines a gap between the first transparent electrode layer 22 and the second transparent electrode layer 32. The liquid crystal composition is filled in the gap of the transparent organic polymer layer. The liquid crystal composition includes a liquid crystal compound. The liquid crystal compound is, for example, at least one selected from the group consisting of Schiff base compounds, azo compounds, azoxy compounds, biphenyl compounds, terphenyl compounds, benzoate ester compounds, tolane compounds, pyrimidine compounds, cyclohexane carboxylic acid ester compounds, phenylcyclohexane compounds, and dioxane compounds.

[0016] The type of the transparent organic polymer layer that holds the liquid crystal composition is, for example, any one selected from the group consisting of a polymer network type, a polymer dispersion type, and a capsule type. In the polymer network type, the transparent organic polymer layer has a transparent polymer network with a three-dimensional mesh structure, and holds the liquid crystal composition in the interconnected mesh-like voids. In the polymer dispersion type, the transparent organic polymer layer has a large number of isolated voids therein, and the liquid crystal composition is held in the voids dispersed in the transparent organic polymer layer. In the capsule type, the liquid crystal composition having an encapsulated shape is held in the transparent organic polymer layer. In addition to the above-mentioned liquid crystal compound, the liquid crystal composition may contain a monomer for forming the transparent organic polymer layer and a dichroic dye.

[0017] [Structure of the Peripheral Portion of the Light-Controlling Sheet 11] As shown in Fig. 1, the light-controlling sheet 11 has, as an example, a rectangular outer shape when viewed from a viewpoint opposite to the plane on which the light-controlling sheet 11 extends. The outer shape of the light-controlling sheet 11 may include curved portions. The light-controlling sheet 11 may have an outer shape that is a polygon other than a rectangle. In Fig. 1, the first electrode sheet 20 is located on the far side of the page relative to the second electrode sheet 30.

[0018] The light-adjusting sheet 11 includes a light-adjusting region 11A, a first non-light-adjusting region 11B, and a second non-light-adjusting region 11C. The light-adjusting region 11A is a region of the light-adjusting sheet 11 where light transmittance can be changed. The light-adjusting region 11A is a region where the light-adjusting layer 40 is sandwiched between the first electrode sheet 20 and the second electrode sheet 30 (see FIG. 2). In other words, the portion of the light-adjusting sheet 11 where the light-adjusting layer 40 is sandwiched between the first electrode sheet 20 and the second electrode sheet 30 forms the light-adjusting region 11A. When viewed from a perspective opposite the plane on which the light-adjusting sheet 11 extends, the light-adjusting region 11A is surrounded by the first non-light-adjusting region 11B and the second non-light-adjusting region 11C. In FIG. 1, the light-adjusting region 11A is indicated by a dot.

[0019] The first non-dimming area 11B and the second non-dimming area 11C form the outer shape of the light-adjusting sheet 11. The first non-dimming area 11B is formed by the first electrode sheet 20 exposed from the second electrode sheet 30 and the light-adjusting layer 40. In other words, the portion of the light-adjusting sheet 11 where the first electrode sheet 20 is exposed from the second electrode sheet 30 and the light-adjusting layer 40 forms the first non-dimming area 11B. The second non-dimming area 11C is formed by the second electrode sheet 30 exposed from the first electrode sheet 20 and the light-adjusting layer 40. In other words, the portion of the light-adjusting sheet 11 where the second electrode sheet 30 is exposed from the first electrode sheet 20 and the light-adjusting layer 40 forms the second non-dimming area 11C.

[0020] The first non-dimming region 11B has a first electrode surface 22S. The first electrode surface 22S is formed by a portion of the first transparent electrode layer 22 of the first electrode sheet 20 that is exposed from the second electrode sheet 30 and the dimming layer 40. In FIG. 1 , the first electrode surface 22S faces the front side of the paper. The first electrode surface 22S has a first terminal portion 22P. The first wiring portion 12 is connected to the first terminal portion 22P.

[0021] The second non-dimming region 11C has a second electrode surface 32S. The second electrode surface 32S is formed by a portion of the second transparent electrode layer 32 of the second electrode sheet 30 that is exposed from the first electrode sheet 20 and the dimming layer 40. In FIG. 1 , the second electrode surface 32S faces the back side of the page. The second electrode surface 32S has a second terminal portion 32P. The second wiring portion 13 is connected to the second terminal portion 32P.

[0022] The first non-light-adjusting region 11B forms an edge portion 11E extending along the first direction D1 in the light-adjusting sheet 11. That is, the edge portion 11E is formed by the end surface of the first electrode sheet 20 provided in the first non-light-adjusting region 11B.

[0023] As shown in Fig. 2, the dimming region 11A has a dimming end surface 11AS. The dimming end surface 11AS is located at the boundary between the dimming region 11A and the first non-dimming region 11B. That is, the dimming end surface 11AS is adjacent to the first non-dimming region 11B. The dimming end surface 11AS includes the end surface of the second electrode sheet 30 and the end surface of the dimming layer 40. The dimming end surface 11AS may be a flat surface, a curved surface, or a discontinuous surface having steps.

[0024] In the first non-dimming region 11B, the first electrode sheet 20 protrudes further outward from the dimming end surface 11AS than the dimming sheet 11. That is, in the first non-dimming region 11B, the first electrode surface 22S of the first transparent electrode layer 22 is exposed from the second electrode sheet 30 and the dimming layer 40.

[0025] The light controlling sheet 11 includes a sealing material 50. The sealing material 50 is an insulating resin having moisture absorption properties. The sealing material 50 is, for example, an ultraviolet curing resin. The sealing material 50 is formed from, for example, an epoxy resin or an acrylic resin. Note that the sealing material 50 is not shown in FIG. 1 .

[0026] The sealing material 50 covers the dimming end surface 11AS, which includes the end surface of the dimming layer 40, at the boundary between the dimming region 11A and the first non-dimming region 11B. The sealing material 50 is disposed so as to straddle the dimming region 11A and the first non-dimming region 11B. The sealing material 50 prevents the liquid crystal composition contained in the dimming layer 40 from being deteriorated by moisture in the air, etc.

[0027] The sealing material 50 contacts the first electrode surface 22S of the first non-dimming region 11B. The sealing material 50 contacts the dimming end surface 11AS. The sealing material 50 contacts the outer surface of the second transparent base material 31 of the second electrode sheet 30, which forms the outer surface of the dimming region 11A.

[0028] As an example, the sealing material 50 is arranged around the entire periphery of the dimming region 11A so as to cover the dimming layer 40 located on the end face of the dimming region 11A. Therefore, the sealing material 50 may be provided not only in the first non-dimming region 11B but also in the second non-dimming region 11C.

[0029] In a cross section perpendicular to the first direction D1 in which the edge 11E extends, the outline of the encapsulant 50 includes a first peak 51, a second peak 52, and a valley 53. The first peak 51 and the second peak 52 are two outlines bounded by the valley 53. The first peak 51 is a portion of the outline of the encapsulant 50 located between the edge 11E and the dimming end surface 11AS. The second peak 52 is a portion of the outline of the encapsulant 50 located so as to straddle the dimming region 11A and the first non-dimming region 11B.

[0030] The valleys 53 are located at the boundaries between the first peaks 51 and the second peaks 52. The valleys 53 extend linearly along the first direction D1 in the first non-light-modulating region 11B. The first peaks 51 are located on the edge 11E side of the valleys 53 within the contour of the encapsulant 50. That is, the first peaks 51 are located between the valleys 53 and the edge 11E. The second peaks 52 are located on the opposite side of the valleys 53 from the edge 11E within the contour of the encapsulant 50. That is, the second peaks 52 are located inside the light-modulating sheet 11 with respect to the valleys 53.

[0031] In the sealing material 50, the first peaks 51 and the second peaks 52 are connected at the valleys 53. A tangent to the first peaks 51 at the valleys 53 and a tangent to the second peaks 52 at the valleys 53 form an angle θ1 toward the outside of the light controlling sheet 11, i.e., toward the edge 11E. The angle θ1 is greater than or equal to 90 degrees and less than 180 degrees.

[0032] In the thickness direction of the dimming sheet 11, the height H1 from the outer surface of the second transparent substrate 31 of the second electrode sheet 30 that forms the outer surface of the dimming area 11A to the top of the second hill portion 52 is, for example, 160 μm or more.

[0033] 3 , in one example of a method for manufacturing the light-controlling sheet 11, first, a laminate 15 is prepared, which includes a first electrode sheet 20, a second electrode sheet 30, and a light-controlling layer 40 between the first electrode sheet 20 and the second electrode sheet 30. Then, the laminate 15 is cut so that the outlines of the first electrode sheet 20 and the second electrode sheet 30 match. This forms the outline of the light-controlling sheet 11, including the edge 11E.

[0034] Next, a portion of the second electrode sheet 30 is removed together with the light-controlling layer 40 that overlaps the portion using a plot cutter 60. This exposes the first electrode surface 22S and forms the light-controlling end surface 11AS in the laminate 15. Therefore, a first non-light-controlling region 11B is formed in the laminate 15.

[0035] That is, the manufacturing method of the light-adjusting sheet 11 includes a step of forming the light-adjusting region 11A and the first non-light-adjusting region 11B in the laminate 15 so that the first non-light-adjusting region 11B forms an edge portion 11E extending in the first direction D1.

[0036] A portion of the first electrode sheet 20, together with the light-controlling layer 40 overlapping the portion, is removed using a plot cutter 60 (not shown). As a result, in the laminate 15, the second electrode surface 32S is exposed and a second non-light-controlling region 11C is formed.

[0037] The manufacturing method of the light-modulating sheet 11 also includes a step of disposing a sealant 50 at the boundary between the light-modulating region 11A and the first non-light-modulating region 11B. Similarly, the sealant 50 is provided in the second non-light-modulating region 11C so as to cover the end face of the light-modulating layer 40.

[0038] 4, the step of disposing the sealing material 50 includes a step of disposing the first sealing material 50A in a portion of the first electrode sheet 20 that will form the first non-dimming region 11B. In detail, first, the uncured first sealing material 50A is applied to the first electrode surface 22S along the first direction D1.

[0039] At this time, the first sealing material 50A is applied to the first non-dimming region 11B so as not to extend beyond the edge 11E, i.e., so as not to extend outside the light controlling sheet 11. Furthermore, as an example, the first sealing material 50A is applied to the first non-dimming region 11B so as not to extend beyond the dimming end surface 11AS, i.e., so as not to extend into the dimming region 11A. The first sealing material 50A is applied to the first non-dimming region 11B so as to fill in the step between the dimming region 11A and the first non-dimming region 11B. As an example, the first sealing material 50A is applied to the first non-dimming region 11B so as to cover the entire dimming end surface 11AS in the thickness direction of the light controlling sheet 11 and to be at approximately the same height as the dimming region 11A.

[0040] The uncured first sealing material 50A is then irradiated with ultraviolet light UV1 to cure the first sealing material 50A. In a cross section perpendicular to the first direction D1, the first sealing material 50A has an outer shape that bulges upward relative to the first electrode surface 22S and toward the outside of the light controlling sheet 11.

[0041] As shown in Figure 5, the step of disposing the sealing material 50 includes a step of disposing the second sealing material 50B so as to overlap the first sealing material 50A and to straddle the light control region 11A and the first non-light control region 11B. Specifically, the uncured second sealing material 50B is applied along the first direction D1 so as to overlap the first sealing material 50A and to straddle the light control region 11A and the first non-light control region 11B. The second sealing material 50B is applied closer to the light control region 11A than the first sealing material 50A, i.e., at a position further inward on the light control sheet 11 than the first sealing material 50A. In other words, the distance from the end of the second sealing material 50B on the edge 11E side to the edge 11E is greater than the distance from the end of the first sealing material 50A on the edge 11E side to the edge 11E.

[0042] In this case, the end of the second sealing material 50B on the edge 11E side is located further inside the light controlling sheet 11 than the edge 11E, and further inside the light controlling sheet 11 than the end of the first sealing material 50A on the edge 11E side. The end of the second sealing material 50B on the edge 11E side forms a valley 53 at the boundary with the first sealing material 50A. That is, by providing the second sealing material 50B on the first sealing material 50A, the valley 53 extending linearly along the first direction D1 is formed. As an example, the valley 53 is formed at approximately the same height as the light controlling region 11A in the thickness direction of the light controlling sheet 11.

[0043] The uncured second sealing material 50B is then irradiated with ultraviolet light UV2 to cure the second sealing material 50B. In a cross section perpendicular to the first direction D1, the second sealing material 50B has an outer shape that bulges upward relative to the second electrode sheet 30 and the first sealing material 50A.

[0044] The sealing material 50 includes a first sealing material 50A and a second sealing material 50B formed by the above-described procedure. In the sealing material 50, the first sealing material 50A forms a first peak portion 51, and the second sealing material 50B forms a second peak portion 52, with the valley portion 53 as the boundary.

[0045] The sealing material 50 may have an interface 54 at the boundary between the first sealing material 50A and the second sealing material 50B. The interface 54 may be, for example, a coating formed on the surface of the first sealing material 50A when the first sealing material 50A is cured with ultraviolet light UV1. The interface 54 may also be, for example, a boundary between the first sealing material 50A and the second sealing material 50B formed due to a difference in the curing state between the first sealing material 50A and the second sealing material 50B. The sealing material 50 having the interface 54 means that the sealing material 50 is formed by a manufacturing method including a step of providing the first sealing material 50A and a step of providing the second sealing material 50B.

[0046] The above procedure is used to manufacture the light-controlling sheet 11. The first wiring portion 12 and the second wiring portion 13 may be attached to the light-controlling sheet 11 after the sealing material 50 is provided, or may be attached to the light-controlling sheet 11 before the sealing material 50 is provided.

[0047] [Operation of the embodiment] If uncured sealant 50 is applied all at once to straddle the dimming region 11A and the first non-dimming region 11B while covering the end faces of the dimming layer 40, sealing leakage, in which the sealant 50 protrudes from the edge portion 11E, is likely to occur. On the other hand, if the amount of sealant 50 is reduced so that the sealant 50 does not protrude from the edge portion 11E, the thickness of the sealant 50 at the boundary between the dimming region 11A and the first non-dimming region 11B becomes insufficient, and sealing cracks, in which the sealant 50 is separated, are likely to occur.

[0048] In this regard, in this embodiment, the sealing material 50 is applied in two stages so that the sealing material 50 has valleys 53. The sealing material 50 covers the end face of the photochromic layer 40 and is provided across the photochromic end face 11AS so as to straddle the photochromic region 11A and the first non-photochromic region 11B. More specifically, the second peaks 52 of the sealing material 50 are provided so as to straddle the photochromic region 11A and the first non-photochromic region 11B. This ensures a thickness of the sealing material 50 at the boundary between the photochromic region 11A and the first non-photochromic region 11B by the height H1 of the second peaks 52. Furthermore, the second peaks 52 of the sealing material 50 are located closer to the photochromic region 11A, which is inside the photochromic sheet 11, than the valleys 53. That is, the distance from the end of the second peak 52 on the edge 11E side to the edge 11E is greater than the distance from the end of the first peak 51 on the edge 11E side to the edge 11E. This prevents the sealing material 50 from leaking out from the edge 11E.

[0049] 6, when the plot cutter 60 cuts the second electrode sheet 30 and the light-controlling layer 40, burrs 31B may be generated on the second transparent substrate 31 near the cut surface, i.e., the light-controlling end surface 11AS. The burrs 31B rise upward as the plot cutter 60 is pulled up after cutting. The burrs 31B have a height of, for example, 30 μm or more and 80 μm or less.

[0050] In this state, if the uncured sealant 50 is applied at once across the dimming region 11A and the first non-dimming region 11B, the sealant 50 may be separated by the burr 31B. In this case, the sealant 50 is separated by the burr 31B into a portion applied to the dimming region 11A and a portion applied to the first non-dimming region 11B. In this case, minute gaps are likely to occur between the dimming end surface 11AS and the sealant 50, which may prevent the sealant 50 from fully preventing deterioration of the liquid crystal composition. On the other hand, simply increasing the amount of sealant 50 to avoid separation of the sealant 50 due to the burr 31B makes it more likely to cause seal leakage, as described above. In this regard, in this embodiment, the thickness of the sealant 50 is ensured by the second peak 52. This prevents the sealant 50 from being separated even when the burr 31B occurs, while suppressing seal leakage, which occurs when the sealant 50 protrudes from the edge 11E.

[0051] Advantages of the Embodiment (1) In this embodiment, after the first sealing material 50A is applied to the first non-dimming region 11B and cured, the second sealing material 50B is applied and cured so as to overlap the first sealing material 50A and to straddle the dimming region 11A and the first non-dimming region 11B. The sealing material 50 covering the edge of the dimming layer 40 at the boundary between the dimming region 11A and the first non-dimming region 11B is then arranged so as to straddle the dimming region 11A and the first non-dimming region 11B and to have linear valleys 53 extending in the first direction D1. The second peaks 52 ensure the thickness of the sealing material 50 at the boundary between the dimming region 11A and the first non-dimming region 11B, ensuring the sealing material 50's ability to prevent deterioration of the dimming layer 40. Furthermore, sealing leakage can be suppressed by making the distance from the end of the second peak 52 on the edge 11E side to the edge 11E greater than the distance from the end of the first peak 51 on the edge 11E side to the edge 11E. Therefore, with the above-described configuration and manufacturing method of the light-modulating sheet 11, sealing leakage can be suppressed while ensuring the function of the sealing material 50 to prevent deterioration of the light-modulating layer 40.

[0052] (2) In this embodiment, in a cross section perpendicular to the first direction D1, a tangent to the first peak portion 51 in the valley portion 53 and a tangent to the second peak portion 52 in the valley portion 53 form an angle θ1 of 90 degrees or more and less than 180 degrees toward the outside of the light controlling sheet 11, i.e., toward the edge portion 11E. For example, if a tangent to the first peak portion 51 and a tangent to the second peak portion 52 in the valley portion 53 form an angle θ1 of less than 90 degrees, the viscosity of the sealing material 50 in an uncured state may be too high, resulting in insufficient adhesion of the sealing material 50. In this regard, if the tangent to the first peak portion 51 and the tangent to the second peak portion 52 form an angle θ1 of 90 degrees or more and less than 180 degrees, the adhesion of the sealing material 50 can be ensured.

[0053] (3) In the thickness direction of the light control sheet 11, the height H1 from the outer surface of the light control region 11A to the top of the second peak 52 is preferably 160 μm or more. As a result, even if a burr 31B occurs near the light control end surface 11AS, the height H1 of the second peak 52 is sufficiently greater than the height of the burr 31B, and therefore, the burr 31B can be prevented from splitting the sealing material 50.

[0054] (4) The sealing material 50 including the first sealing material 50A, the second sealing material 50B, and the interface 54 means that the sealing material 50 is formed by a manufacturing method including a step of providing the first sealing material 50A and a step of providing the second sealing material 50B. In other words, if the sealing material 50 is the light-controlling sheet 11 including the first sealing material 50A, the second sealing material 50B, and the interface 54, the advantage of (1) above can be obtained.

[0055] [Modifications] The above embodiment can be modified as follows: The modifications can be combined within the scope of technical compatibility.

[0056] The light-controlling sheet 11 may include other functional layers, such as an ultraviolet-shielding layer, an infrared-shielding layer, an alignment layer, an adhesive layer, or a protective layer. In the light-controlling sheet 11, as long as the outer periphery of the light-controlling layer 40 is covered with the sealant 50, the light-controlling method of the light-controlling layer 40 is not limited to the polymer network type and polymer dispersion type examples described in the above embodiments. For example, the light-controlling layer 40 may be a layer that controls light using a suspended particle device (SPD) method or an electrochromic method, or may be a liquid crystal layer that does not include a transparent organic polymer layer.

[0057] The light controlling sheet 11 is not limited to a rectangular or polygonal shape, but may be a geometric shape such as a circle or an ellipse, or may be an irregular shape other than a geometric shape. The light controlling sheet 11 is not limited to a two-dimensional planar shape, but may be a curved shape such as a cylindrical shape, a spherical shape, or a wavy shape.

[0058] The material forming the first sealing material 50A and the material forming the second sealing material 50B may be different from each other. In this case, the interface 54 refers to the boundary between the material forming the first sealing material 50A and the material forming the second sealing material 50B.

[0059] The sealing material 50 may include a plurality of valleys 53. For example, the sealing material 50 may include a first valley and a second valley as the plurality of valleys 53. The first valley and the second valley extend linearly along the first direction D1 at different positions within the sealing material 50 in a cross section perpendicular to the first direction D1. In this case, the sealing material 50 may be applied in three stages so that the sealing material 50 includes the first valley and the second valley. That is, in a cross section perpendicular to the first direction D1, the outer shape of the sealing material 50 may include a third peak in addition to the first peak 51 and the second peak 52. Note that both the first valley and the second valley may be located in the first non-dimming region 11B, or one may be located in the dimming region 11A and the other may be located in the first non-dimming region 11B. That is, the third peaks may be located closer to the edge 11E than the first peaks 51, or the third peaks may be located closer to the inside of the light-adjusting sheet 11 than the second peaks 52. In other words, the distance from the edge of the third peak on the edge 11E side to the edge 11E may be shorter than the distance from the edge of the first peak 51 on the edge 11E side to the edge 11E. The distance from the edge of the third peak on the edge 11E side to the edge 11E may be longer than the distance from the edge of the second peak 52 on the edge 11E side to the edge 11E. By arranging the sealing material 50 so as to have multiple valleys 53, it is possible to ensure the thickness of the sealing material 50 at the boundary between the light-adjusting region 11A and the first non-light-adjusting region 11B while preferably preventing sealing leakage.

[0060] [Test Example: Sample Preparation Method] Below, a test example using the light controlling sheet 11 will be described. Note that the following test example is an example for explaining the advantages of the above embodiment, and does not limit the present disclosure.

[0061] In the test example, five levels of light-adjusting sheets 11 were produced: samples A1, A2, B1, B2, and B3. In the test example light-adjusting sheets 11, the width of the first non-light-adjusting region 11B was 2 mm in a cross-sectional view perpendicular to the first direction D1. An ultraviolet-curable resin was used for the encapsulant 50. A dispensing device (product name: MJET-S-2, manufactured by Musashi Engineering, Inc.) was used to apply the uncured encapsulant 50.

[0062] In the test examples, for samples A1 and A2, the sealing material 50 was formed in two stages: a first sealing material 50A corresponding to a first layer and a second sealing material 50B corresponding to a second layer. First, for samples A1 and A2, the first sealing material 50A was applied to the first non-dimming region 11B, and then the second sealing material 50B was applied from above the first sealing material 50A so as to span both the dimming region 11A and the first non-dimming region 11B.

[0063] For sample A1, the first sealing material 50A was applied to the first non-dimming region 11B under conditions of a pressure of 480 kPa, a sealing speed of 130 mm / s, and a sealing width of 2 mm. For sample A2, the first sealing material 50A was applied to the first non-dimming region 11B under conditions of a pressure of 400 kPa, a sealing speed of 170 mm / s, and a sealing width of 2 mm. That is, for samples A1 and A2, the first sealing material 50A was configured to cover the entire first electrode surface 22S located in the first non-dimming region 11B.

[0064] For sample A1, the second sealing material 50B was applied so as to straddle the dimming region 11A and the first non-dimming region 11B under conditions of a pressure of 480 kPa, a sealing speed of 130 mm / s, and a sealing width of 3.6 mm. For sample A2, the second sealing material 50B was applied so as to straddle the dimming region 11A and the first non-dimming region 11B under conditions of a pressure of 400 kPa, a sealing speed of 170 mm / s, and a sealing width of 3.6 mm.

[0065] In Samples A1 and A2, the second sealing material 50B was applied 0.4 mm from the edge 11E so that 1.6 mm of the 3.6 mm sealing width overlapped the first sealing material 50A. That is, in Samples A1 and A2, 1.6 mm of the 3.6 mm sealing width of the second sealing material 50B was located in the first non-dimming region 11B and 2 mm was located in the dimming region 11A.

[0066] In addition, in sample A2, compared to sample A1, the pressure is lower and the sealing speed is higher for both the first sealing material 50A and the second sealing material 50B, so the amount of sealing material 50 applied is smaller than that of sample A1.

[0067] In the test examples, for samples B1 to B3, the sealing material 50 was applied at once so as to straddle the dimming region 11A and the first non-dimming region 11B. For sample B1, the sealing material 50 was applied under conditions of a pressure of 480 kPa, a sealing speed of 130 mm / s, and a sealing width of 4 mm. For sample B2, the sealing material 50 was applied under conditions of a pressure of 400 kPa, a sealing speed of 170 mm / s, and a sealing width of 4 mm. For sample B3, the sealing material 50 was applied under conditions of a pressure of 480 kPa, a sealing speed of 100 mm / s, and a sealing width of 4 mm. In samples B1 to B3, of the 4 mm sealing width, 2 mm of the sealing material 50 was located in the first non-dimming region 11B and 2 mm was located in the dimming region 11A.

[0068] [Test Example: Evaluation Method] In the test example, for samples A1 and A2, the angle θ1 formed between a tangent to the first peak portion 51 in the valley portion 53 and a tangent to the second peak portion 52 in the valley portion 53 was measured. The angle θ1 was measured from an image in a cross-sectional view perpendicular to the first direction D1.

[0069] In the test examples, the presence or absence of sealing leakage / backing and sealing cracks was measured by visual inspection for samples A1, A2, and B1 to B3. Specifically, 100 sheets of each of the light-controlling sheets 11 for samples A1, A2, and B1 to B3 were produced, and then the presence or absence of sealing leakage / backing and sealing cracks was visually confirmed.

[0070] Note that "sealing leakage" refers to a state in which the sealing material 50 extends beyond the edge 11E and onto the outside of the light-adjusting sheet 11. "Reaching the back" refers to a state in which the sealing material 50 extends beyond the edge 11E and reaches the surface of the light-adjusting sheet 11 on the first transparent substrate 21 side, which is the back surface of the light-adjusting sheet 11. Note that "sealing crack" refers to a state in which the sealing material 50 located in the first non-light-adjusting region 11B and the sealing material 50 located in the light-adjusting region 11A are separated so as to be discontinuous in a cross section perpendicular to the first direction D1. For example, the state in which the sealing material 50 is separated by a burr 31B, as shown in Figure 6, is an example of a state in which a sealing crack has occurred.

[0071] In the appearance inspection, the presence or absence of seal leakage / backing and seal cracking for each level were scored from 1 to 3 points. As the inspection results for 100 sheets of light-controlling sheets 11 at each level, a seal leakage / backing occurrence rate of 0% was scored as 3 points, a seal leakage / backing occurrence rate of more than 0% but less than 5% was scored as 2 points, and a seal crack occurrence rate of 5% or more was scored as 1 point. Similarly, as the inspection results for 100 sheets of light-controlling sheets 11 at each level, a seal crack occurrence rate of 0% was scored as 3 points, a seal crack occurrence rate of more than 0% but less than 5% was scored as 2 points, and a seal crack occurrence rate of 5% or more was scored as 1 point.

[0072] In the test example, a heat resistance test was conducted on samples A1, A2, and B1 to B3. In the heat resistance test, each sample was placed in an oven at 110°C for 1,000 hours. After that, the light-controlling sheet 11 was removed from the oven and electricity was applied. The width of the area in the light-controlling region 11A where light control did not occur was measured as the thermal degradation width. The degradation width was measured in the direction from the light-controlling end surface 11AS toward the center of the light-controlling sheet 11 within the plane of the light-controlling sheet 11. As a reference standard, a degradation width of 5 mm or less was considered pass, and a degradation width of more than 5 mm was considered fail.

[0073] In this test example, the light-adjusting sheet 11 was configured so that the non-energized state was opaque, and the energized state was transparent. Before the heat resistance test, it was confirmed that each sample was in an opaque state across the entire light-adjusting region 11A when not energized, and in a transparent state across the entire light-adjusting region 11A when energized.

[0074] 7 shows the measurement results of the angle θ1 for samples A1 and A2. For sample A1, the angle θ1 was 170 degrees. For sample A2, the angle θ1 was 173 degrees.

[0075] The table shown in Figure 7 shows the results of the visual inspection of samples A1, A2, and B1 to B3. In sample B1, it was confirmed that both seal leakage / reverse wrapping and seal cracking occurred at an incidence rate of more than 0% and less than 5%. In sample B2, which had a reduced amount of sealant 50 applied compared to sample B1, no seal leakage / reverse wrapping was confirmed, but the incidence of seal cracking was higher than sample B1. In sample B3, which had a greater amount of sealant 50 applied compared to sample B1, no seal cracking was confirmed, but the incidence of seal leakage / reverse wrapping was higher than sample B1.

[0076] In contrast, neither seal leakage / reverse wrapping nor seal cracking was observed in sample A1. Furthermore, in sample A2, which had a reduced coating amount of sealant 50 compared to sample A1, seal leakage / reverse wrapping was not observed, and the rate of seal cracking was equivalent to that of sample B1. Therefore, it was confirmed that samples A1 and A2, compared to samples B1 to B3, were able to suppress seal leakage while ensuring the thickness of sealant 50 at the boundary between light control region 11A and first non-light control region 11B.

[0077] The table shown in Figure 7 shows the measurement results of the deterioration width in the heat resistance test for samples A1, A2, and B1 to B3. The deterioration width for sample A1 was 0.5 mm. The deterioration width for samples A2, B1, and B3 was 1 mm. In contrast, the deterioration width for sample B2 was 30 mm. Therefore, it was confirmed that samples A1 and A2 were able to ensure the function of the sealant 50 to prevent deterioration of the liquid crystal composition while suppressing sealing leakage compared to samples B1 to B3.

[0078] [Notes] The above embodiments and modifications lead to the following technical ideas: [Note 1] A light-controlling sheet comprising: a first electrode sheet having a first transparent electrode layer; a second electrode sheet having a second transparent electrode layer; a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer; and a sealant, wherein a portion of the light-controlling layer sandwiched between the first electrode sheet and the second electrode sheet forms a light-controlling region, and a portion of the first electrode sheet exposed from the light-controlling layer and the second electrode sheet forms a non-light-controlling region, the sealant covers an end face of the light-controlling layer at the boundary between the light-controlling region and the non-light-controlling region and is disposed so as to straddle the light-controlling region and the non-light-controlling region, and the non-light-controlling region forms an edge portion of the light-controlling sheet extending in a first direction, The sealing material includes a first sealing material arranged in a portion of the first electrode sheet that forms the non-dimming region, a second sealing material arranged so as to overlap the first sealing material and to straddle the dimming region and the non-dimming region, and an interface located at the boundary between the first sealing material and the second sealing material.

Claims

1. A light-adjusting sheet comprising: a first electrode sheet having a first transparent electrode layer; a second electrode sheet having a second transparent electrode layer; a light-adjusting layer located between the first transparent electrode layer and the second transparent electrode layer; and a sealing material; a portion of the light-adjusting layer sandwiched between the first electrode sheet and the second electrode sheet forms a light-adjusting region; a portion of the first electrode sheet exposed from the light-adjusting layer and the second electrode sheet forms a non-light-adjusting region; the sealing material covers the edge of the light-adjusting layer at the boundary between the light-adjusting region and the non-light-adjusting region and is arranged to straddle the light-adjusting region and the non-light-adjusting region; the non-light-adjusting region forms an edge portion of the light-adjusting sheet extending in a first direction; and the sealing material has a linear valley portion extending in the first direction, and in a cross section perpendicular to the first direction, has a first peak portion and a second peak portion that are two outlines bounded by the valley portion; A light-controlling sheet, wherein the first peak is located between the valley and the edge of the non-light-controlling region, and the second peak is located inside the light-controlling sheet relative to the valley and so as to straddle the light-controlling region and the non-light-controlling region.

2. A light-controlling sheet as described in claim 1, wherein in the cross section, the first peak and the second peak are connected at the valley, and a tangent to the first peak at the valley and a tangent to the second peak at the valley form an angle of 90 degrees or more and less than 180 degrees toward the outside of the light-controlling sheet.

3. The light-controlling sheet according to claim 1 or 2, wherein the valley portion is a first valley portion, and the sealing material further comprises a linear second valley portion extending in the first direction.

4. A method for manufacturing a light-controlling sheet, comprising: a laminate comprising a first electrode sheet having a first transparent electrode layer, a second electrode sheet having a second transparent electrode layer, and a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer; the method comprising: forming a light-controlling region where the light-controlling layer is sandwiched between the first electrode sheet and the second electrode sheet; and a non-light-controlling region where the first electrode sheet is exposed from the light-controlling layer and the second electrode sheet; and arranging a sealant that covers the end faces of the light-controlling layer at the boundary between the light-controlling region and the non-light-controlling region. The method for manufacturing a light-controlling sheet, wherein the step of arranging the sealing material includes the steps of applying an uncured first sealing material to a portion of the first electrode sheet that will form the non-light-controlling region, curing the first sealing material after the step of applying the first sealing material, applying an uncured second sealing material so as to overlap the first sealing material and to straddle the light-controlling region and the non-light-controlling region, and curing the second sealing material after the step of applying the second sealing material.

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