Light control sheet and method for manufacturing light control sheet

The light-controlling sheet design with a two-stage sealing material application forms peaks and valleys to ensure adequate thickness and adhesion, preventing leakage and protecting the light-controlling layer from moisture.

JP2025159580APending Publication Date: 2025-10-21TOPPAN HOLDINGS INC
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Patent Information

Application Number
JP2024062265
Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-04-08
Publication Date
2025-10-21

AI Technical Summary

Technical Problem

The challenge lies in ensuring sufficient sealing material thickness to prevent deterioration of the light-controlling layer while avoiding leakage by preventing the sealing material from protruding beyond the edges of the light-controlling sheet.

Method used

A light-controlling sheet design with a sealing material that forms peaks and valleys across the dimming and non-dimming areas, ensuring adequate thickness and adhesion without leakage, achieved through a two-stage application process.

Benefits of technology

Prevents sealing material leakage while maintaining the sealing material's ability to protect the light-controlling layer from moisture, ensuring effective adhesion and durability.

✦ Generated by Eureka AI based on patent content.

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Abstract

To provide a light control sheet capable of suppressing the leak of a sealing material protruding from an edge while obtaining the deterioration prevention function of a light control layer by the sealing material, and a method for manufacturing the light control sheet.SOLUTION: A light control sheet 11 includes a first electrode sheet 20, a second electrode sheet 30 and a light control layer 40. The light control sheet 11 includes: a light control area 11A having the light control layer 40 sandwiched between the first electrode sheet 20 and the second electrode sheet 30; a first non-light control area 11B having the first electrode sheet 20 exposed from the light control layer 40 and the second electrode sheet 30; and a sealing material 50 for covering the end surface of the light control layer 40. The sealing material 50 includes a first mountain part 51, a second mountain part 52 and a valley part 53 in a cross section orthogonal to a first direction; the first mountain part 51 is positioned on the side of the edge 11E to the valley part 53; and the second mountain part 52 is positioned on the side opposite to the edge 11E to the valley part 53 so as to straddle the light control area 11A and the first non-light control area 11B.SELECTED DRAWING: Figure 2
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Description

[Technical Field]

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

[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 has 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 so as to cover the light-adjusting layer located on the edge face 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. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-070962 Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0007] A light-controlling sheet for solving the above problems includes 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 includes a light-controlling region where the light-controlling layer is sandwiched between the first electrode sheet and the second electrode sheet, a non-light-controlling region where the first electrode sheet is exposed from the light-controlling layer and the second electrode sheet, and a light-controlling sheet that covers an end face of the light-controlling layer at the boundary between the light-controlling region and the non-light-controlling region, and and a sealing material arranged so as to straddle the dimming area and the non-dimming area, wherein the non-dimming area forms an edge portion of the dimming 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 which are two outline lines bounded by the valley portion, the first peak portion being located on the edge side of the valley portion, and the second peak portion being located on the opposite side of the valley portion to the edge and straddling the dimming area and the non-dimming area.

[0008] According to the above configuration, the second peaks of the sealing material, which are positioned across the dimming area and non-dimming area, are located closer to the dimming area, which is inside the dimming sheet, than the valleys, which ensures the thickness of the sealing material at the boundary between the dimming area and non-dimming area by the height of the second peaks, while preventing leakage of the sealing material from the edges.

[0009] In the light-controlling sheet, the first peaks and the second peaks may intersect at the valleys, and a tangent to the first peaks at the intersection and a tangent to the second peaks at the intersection may form an angle of 90 degrees or more and less than 180 degrees toward the outside of the light-controlling sheet. For example, if the tangent to the first peaks and the tangent to the second peaks at the valleys form an angle of less than 90 degrees, the viscosity of the sealing material in an uncured state may be too high, making it difficult to obtain sufficient adhesion. In this regard, if the sealing material is in a state where the tangent to the first peaks and the tangent to the second peaks form an angle of 90 degrees or more and less than 180 degrees, the adhesion of the sealing material can be ensured.

[0010] In the light-adjusting sheet, the valleys may be first valleys, and the sealing material may further include linear second valleys extending in the first direction. According to the above configuration, by arranging the sealing material so as to include multiple valleys, it is possible to ensure the thickness of the sealing material at the boundary between the light-adjusting region and the non-light-adjusting region and to effectively prevent sealing leakage.

[0011] A method for manufacturing a light-controlling sheet to solve the above problem is a method for manufacturing a light-controlling sheet that includes 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, wherein the light-controlling layer is sandwiched between the first electrode sheet and the second electrode sheet so that a non-light-controlling region of the first electrode sheet exposed from the light-controlling layer and the second electrode sheet constitutes an edge portion extending in a first direction in the light-controlling sheet; and a non-dimming region in the light-adjusting sheet, and a process of disposing a sealant that covers an edge of the light-adjusting layer at the boundary between the light-adjusting region and the non-dimming region, the process of disposing the sealant including the steps of applying an uncured first sealant to a portion of the first electrode sheet that constitutes the non-dimming region and then curing the first sealant, and applying an uncured second sealant to overlap the first sealant and straddle the light-adjusting region and the non-dimming region and then curing the second sealant. The above manufacturing method can ensure the thickness of the sealant at the boundary between the light-adjusting region and the non-dimming region while preventing leakage. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to prevent the sealing material from leaking out from the edges while ensuring the function of the sealing material to prevent deterioration of the light-control layer. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a plan view of a light-controlling unit equipped with a light-controlling sheet. [Figure 2] FIG. 2 is a cross-sectional view of the light controlling sheet taken along line 2-2 in FIG. [Figure 3] FIG. 3 is a cross-sectional view of a laminate in which the layers constituting the light-controlling sheet are stacked in the manufacturing process of the light-controlling sheet. [Figure 4] FIG. 4 is a cross-sectional view of a light controlling sheet in a state where a first sealing material is provided in a first non-light controlling region during a manufacturing process of the light controlling sheet. [Figure 5]FIG. 5 is a cross-sectional view of a light-modulating sheet in a state where a second sealing material is provided on the first sealing material so as to straddle the light-modulating region and the first non-light-modulating region in a manufacturing process of the light-modulating sheet. [Figure 6] FIG. 6 is a cross-sectional view of a light-modulating sheet in which the sealing material is divided by burrs when the sealing material is applied at once so as to straddle the light-modulating region and the first non-light-modulating region. [Figure 7] FIG. 7 is a table showing sealing process conditions and evaluation results in the test examples. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, one embodiment of the light controlling sheet will be described with reference to FIGS. As shown in FIG. 1, the light controlling unit 10 includes a light controlling sheet 11, a first wiring section 12, and a second wiring section 13. The light controlling 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 controlling sheet 11. The first wiring section 12 and the second wiring section 13 are, for example, flexible printed circuit boards (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 controlling sheet 11.

[0015] [Layer structure of light control 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.

[0016] 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.

[0017] 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.

[0018] The light-switching 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 between the first transparent electrode layer 22 and the second transparent electrode layer 32, the light-switching layer 40 exhibits an opaque state with low diffuse transmittance. On the other hand, when a voltage is applied between the first transparent electrode layer 22 and the second transparent electrode layer 32, the light-switching layer 40 exhibits a transparent state with higher diffuse transmittance than in the opaque state. For example, the light-switching layer 40 has a thickness of 5 μm or more and 30 μm or less.

[0019] 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.

[0020] 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.

[0021] [Structure of the outer periphery of the light-control sheet 11] 1, the light controlling sheet 11 has, for example, a rectangular outer shape when viewed from a viewpoint opposite to the plane on which the light controlling sheet 11 extends, but the outer shape may include curved portions or may have a polygonal outer shape. In FIG. 1, the first electrode sheet 20 is located on the far side of the page relative to the second electrode sheet 30.

[0022] The light-adjusting sheet 11 comprises 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). When viewed from a viewpoint opposite to 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.

[0023] The first non-dimming area 11B and the second non-dimming area 11C form the outer shape of the dimming sheet 11. The first non-dimming area 11B is formed by the second electrode sheet 30 and the first electrode sheet 20 exposed from the dimming layer 40. The second non-dimming area 11C is formed by the first electrode sheet 20 and the second electrode sheet 30 exposed from the dimming layer 40.

[0024] The first non-dimming region 11B has a first electrode surface 22S. The first electrode surface 22S is 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.

[0025] The second non-dimming region 11C has a second electrode surface 32S. The second electrode surface 32S is the 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.

[0026] The first non-light adjusting region 11B constitutes an edge portion 11E extending along the first direction D1 in the light adjusting sheet 11. In other words, 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.

[0027] 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.

[0028] In the first non-dimming region 11B, the first electrode sheet 20 protrudes further outward from the dimming sheet 11 than the dimming end surface 11AS. 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.

[0029] 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 curable resin. The sealing material 50 is made of, for example, an epoxy resin or an acrylic resin. Note that the sealing material 50 is not shown in FIG. 1.

[0030] 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.

[0031] 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 that forms the outer surface of the dimming region 11A.

[0032] 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.

[0033] In a cross section perpendicular to the first direction D1 in which the edge 11E extends, the contour 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 contour lines separated by the valley 53. The first peak 51 is located between the edge 11E and the dimming end surface 11AS within the contour of the encapsulant 50. The second peak 52 is located so as to straddle the dimming region 11A and the first non-dimming region 11B within the contour of the encapsulant 50.

[0034] The valley portion 53 is located at the boundary between the first peak portion 51 and the second peak portion 52. The valley portion 53 extends linearly in the first direction D1 in the first non-dimming region 11B. The first peak portion 51 is located on the edge 11E side of the contour of the sealing material 50 relative to the valley portion 53. The second peak portion 52 is located on the opposite side of the contour of the sealing material 50 from the edge 11E relative to the valley portion 53.

[0035] In the sealing material 50, the first peaks 51 and the second peaks 52 intersect 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 equal to or greater than 90 degrees and less than 180 degrees.

[0036] In the thickness direction of the light controlling sheet 11, the height H1 from the outer surface of the second transparent base material 31 of the second electrode sheet 30 that forms the outer surface of the light controlling region 11A to the top of the second mountain portion 52 is, for example, 160 μm or more.

[0037] [Method of manufacturing light controlling sheet 11] 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.

[0038] Next, a portion of the second electrode sheet 30 is removed together with the light-controlling layer 40 that overlaps the portion using a plotter cutter 60. This exposes the first electrode surface 22S and forms a light-controlling end surface 11AS in the laminate 15. Therefore, a first non-light-controlling region 11B is formed in the laminate 15.

[0039] That is, the manufacturing method of the light-controlling sheet 11 includes a step of partitioning the light-controlling region 11A and the first non-light-controlling region 11B within the light-controlling sheet 11 so that the first non-light-controlling region 11B forms an edge portion 11E extending in the first direction D1.

[0040] A portion of the first electrode sheet 20, together with the light-controlling layer 40 overlapping this portion, is removed using a plot cutter 60. As a result, in the laminate 15, the second electrode surface 32S is exposed and a second non-light-controlling region 11C is formed.

[0041] The manufacturing method of the light-modulating sheet 11 also includes a step of arranging 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.

[0042] 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 constitutes 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.

[0043] 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.

[0044] 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.

[0045] 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, that is, at a position closer to the inside of the light control sheet 11 than the first sealing material 50A.

[0046] In this case, the end of the second sealing material 50B on the edge 11E side is located closer to the light control region 11A than the edge 11E and closer to the light control region 11A 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 in the first direction D1 is formed. As an example, the valley 53 is formed at the same height as the light control region 11A in the thickness direction of the light controlling sheet 11.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] [Operation of the embodiment] If uncured sealing material 50 is applied all at once to cover the edge of the photochromic layer 40 and straddle the photochromic region 11A and the first non-photochromic region 11B, sealing leakage, in which the sealing material 50 overflows from the edge 11E, is likely to occur. On the other hand, if the amount of sealing material 50 is reduced so that the sealing material 50 does not overflow from the edge 11E, the thickness of the sealing material 50 at the boundary between the photochromic region 11A and the first non-photochromic region 11B becomes insufficient, and sealing cracks, in which the sealing material 50 is separated, are likely to occur.

[0052] 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 light control layer 40 and is provided across the light control end face 11AS so as to straddle the light control region 11A and the first non-light control region 11B. More specifically, the second peaks 52 of the sealing material 50 are provided so as to straddle the light control region 11A and the first non-light control region 11B. This ensures a thickness of the sealing material 50 at the boundary between the light control region 11A and the first non-light control 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 light control region 11A, which is inside the light control sheet 11, than the valleys 53. This prevents the sealing material 50 from leaking out from the edge 11E.

[0053] 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.

[0054] 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 divided by the burr 31B. In this case, the sealant 50 is divided 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 prevent the sealant 50 from being divided by the burr 31B easily leads to 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 divided even when the burr 31B occurs, while suppressing leakage, in which the sealant 50 protrudes from the edge 11E.

[0055] [Effects 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. As a result, the sealing material 50 covering the end face of the dimming layer 40 at the boundary between the dimming region 11A and the first non-dimming region 11B is 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, the second peaks 52 of the sealing material 50, which are positioned across the light control area 11A and the first non-light control area 11B, are located closer to the light control area 11A, which is more inside the light control sheet 11, than the valleys 53, and therefore sealing leakage can be suppressed. Therefore, with the above-described configuration and manufacturing method of the light control sheet 11, sealing leakage can be suppressed while ensuring the function of the sealing material 50 to prevent deterioration of the light control layer 40.

[0056] (2) In this embodiment, in a cross section perpendicular to the first direction D1, a tangent to the first peaks 51 in the valleys 53 and a tangent to the second peaks 52 in the valleys 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 11E. For example, if the tangent to the first peaks 51 and the tangent to the second peaks 52 in the valleys 53 form an angle θ1 less than 90 degrees, the viscosity of the sealing material 50 in an uncured state may be too high, making it difficult to obtain sufficient adhesion of the sealing material 50. In this regard, if the tangent to the first peaks 51 and the tangent to the second peaks 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.

[0057] (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 sealing material 50 can be suitably prevented from being broken by the burr 31B.

[0058] (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 the steps of providing the first sealing material 50A and 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 effect of (1) above can be obtained.

[0059] [Example of change] The above embodiment can be modified as follows: The modifications can be combined within the scope of technical compatibility.

[0060] The light-control sheet 11 may also include other functional layers such as an ultraviolet-shielding layer, an infrared-shielding layer, an alignment layer, an adhesive layer, and 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 in the above embodiments. For example, the light-controlling layer 40 may be a layer that controls light using an SPD (Suspended Particle Device) method or an electrochromic method, or may be a liquid crystal layer that does not have a transparent organic polymer layer.

[0061] 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.

[0062] 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.

[0063] The sealing material 50 may have a plurality of valleys 53. For example, the sealing material 50 may have a first valley and a second valley as the plurality of valleys 53. The first valley and the second valley extend linearly in the first direction D1 at different positions in 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 has 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 have 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 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-modulating sheet 11 than the second peaks 52. 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-modulating region 11A and the first non-light-modulating region 11B, while suitably preventing sealing leakage.

[0064] [Test example: Sample preparation method] The following describes a test example using the light controlling sheet 11. Note that the following test example is an example for explaining the effects of the above embodiment, and does not limit the present disclosure.

[0065] In the test example, five levels of light-controlling sheets 11 were produced: samples A1, A2, B1, B2, and B3. In the light-controlling sheets 11 of the test examples, the width of the first non-light-controlling region 11B was 2 mm in a cross-sectional view perpendicular to the first direction D1. An ultraviolet-curable resin was used for the sealing material 50. A dispensing device (product name: MJET-S-2, manufactured by Musashi Engineering Co., Ltd.) was used to apply the uncured sealing material 50.

[0066] 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 the first layer and a second sealing material 50B corresponding to the 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.

[0067] For Sample A1, first sealing material 50A was applied to 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, first sealing material 50A was applied to 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 electrode surface 22S located in first non-dimming region 11B was entirely covered with first sealing material 50A.

[0068] For sample A1, second sealing material 50B was applied so as to straddle light control region 11A and first non-light control 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, second sealing material 50B was applied so as to straddle light control region 11A and first non-light control 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.

[0069] 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.

[0070] 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.

[0071] In the test examples, for samples B1 to B3, the sealing material 50 was applied at once across 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.

[0072] [Test example: Evaluation method] In the test example, for samples A1 and A2, the angle θ1 formed between the tangent to the first peak portion 51 in the valley portion 53 and the 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.

[0073] In the test examples, the presence or absence of sealing leakage, backside cracks, and sealing cracks was measured by visual inspection for samples A1, A2, B1 to B3. In detail, 100 sheets of each of the light control sheets 11 for samples A1, A2, B1 to B3 were produced, and then the presence or absence of sealing leakage, backside cracks, and sealing cracks was visually confirmed.

[0074] Note that "seal leakage" refers to a state in which the sealing material 50 extends beyond the edge 11E and onto the outside of the light-controlling 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-controlling sheet 11 on the first transparent substrate 21 side, which is the back surface of the light-controlling sheet 11. Note that "seal crack" refers to a state in which, in a cross section perpendicular to the first direction D1, the sealing material 50 located in the first non-light-controlling region 11B and the sealing material 50 located in the light-controlling region 11A include a portion that is separated so that they are discontinuous. For example, the state in which the sealing material 50 is separated by a burr 31B, as shown in FIG. 6, is an example of a state in which a seal crack has occurred.

[0075] In the visual inspection, the presence or absence of seal leakage / backing and seal cracking for each level were scored from 1 to 3 points. As for the inspection results of 100 sheets of light-controlling film 11 at each level, a seal leakage / backing occurrence rate of 0% was scored as 3 points, a rate of more than 0% but less than 5% was scored as 2 points, and a rate of 5% or more was scored as 1 point. Similarly, as for the inspection results of 100 sheets of light-controlling film 11 at each level, a seal crack occurrence rate of 0% was scored as 3 points, a rate of more than 0% but less than 5% was scored as 2 points, and a rate of 5% or more was scored as 1 point.

[0076] 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, and 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 defined as the width in the direction from the light controlling end surface 11AS toward the center of the light controlling sheet 11 within the surface 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.

[0077] In this test example, the light-adjusting sheet 11 was configured so that it was opaque when not energized, and transparent when energized. 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 transparent across the entire light-adjusting region 11A when energized.

[0078] [Test example: Evaluation results] 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.

[0079] The table in Figure 7 shows the results of the visual inspection of samples A1, A2, B1 to B3. In sample B1, it was confirmed that both seal leakage / backward turning 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 / backward turning was confirmed, but the incidence rate 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 rate of seal leakage / backward turning was higher than sample B1.

[0080] 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 the dimming region 11A and the first non-dimming region 11B.

[0081] The table in FIG. 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 suppress sealing leakage while ensuring the function of the sealant 50 to prevent deterioration of the liquid crystal composition compared to samples B1 to B3.

[0082] [Note] According to the above-described embodiment and modified examples, the following technical ideas can be derived. [Appendix 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, and a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer, a light control region in which the light control layer is sandwiched between the first electrode sheet and the second electrode sheet; a non-light-control region in which the first electrode sheet is exposed from the light-control layer and the second electrode sheet; a sealing material that covers an end face of the photochromic layer at the boundary between the photochromic region and the non-photochromic region and is arranged so as to straddle the photochromic region and the non-photochromic region; The non-light-modulating region constitutes an edge portion of the light-modulating sheet extending in a first direction, The sealing material includes a first sealing material disposed in a portion of the first electrode sheet that constitutes the non-dimming region, a second sealing material disposed 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. Dimming sheet. [Explanation of symbols]

[0083] θ1…Angle D1…first direction 11...Light-adjusting sheet 11A…Dimmer area 11B…1st non-dimming area 11E…Edge 20...First electrode sheet 21...First transparent base material 22...First transparent electrode layer 22S…1st electrode surface 30...Second electrode sheet 31...Second transparent base material 32...Second transparent electrode layer 32S…Second electrode surface 40...Photochromic layer 50...Sealing material 50A…1st sealing material 50B…Second sealing material 51...First mountain section 52...Second mountain section 53... Valley 54...Interface

Claims

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; and a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer, a light-control region in which the light-control layer is sandwiched between the first electrode sheet and the second electrode sheet; a non-light-control region in which the first electrode sheet is exposed from the light-control layer and the second electrode sheet; a sealing material that covers an end face of the photochromic layer at the boundary between the photochromic region and the non-photochromic region and is arranged so as to straddle the photochromic region and the non-photochromic region; The non-light-modulating region constitutes an edge portion of the light-modulating sheet extending in a first direction, 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 which are two outlines bounded by the valley portion; the first peak portion is located on the edge portion side with respect to the valley portion, The second peak is located on the opposite side of the valley from the edge and across the dimming region and the non-dimming region. Dimming sheet.

2. the first peak and the second peak intersect at the valley, a tangent to the first peak at the intersection and a tangent to the second peak at the intersection form an angle of 90 degrees or more and less than 180 degrees toward the outside of the light controlling sheet; The light-controlling sheet according to claim 1 .

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

4. A method for manufacturing 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; and a light-controlling layer located between the first transparent electrode layer and the second transparent electrode layer, A process of dividing the light-adjusting sheet into a light-adjusting region where the light-adjusting layer is sandwiched between the first electrode sheet and the second electrode sheet and a non-light-adjusting region so that the non-light-adjusting region where the first electrode sheet is exposed from the light-adjusting layer and the second electrode sheet constitutes an edge portion extending in a first direction in the light-adjusting sheet; and a step of disposing a sealant covering an end face of the photochromic layer at a boundary between the photochromic region and the non-photochromic region, The step of arranging the sealing material includes a step of applying an uncured first sealing material to a portion of the first electrode sheet that constitutes the non-dimming region, and then curing the first sealing material; and a step of applying an uncured second sealing material so as to overlap the first sealing material and to span the dimming region and the non-dimming region, and then curing the second sealing material. A method for manufacturing light-controlling sheets.

Citation Information

Patent Citations

  • Lighting control sheet

    JP2023070962A