Light-controlling film

Abstract

To solve such problems that, in a case where a light adjusting module is arranged in a boundary between the outdoor side and the indoor side or a boundary between two spaces with a large temperature difference, a moisture content may adhere to the light adjusting module, and a variable function of the light transmissivity in the light adjusting module may be reduced when the moisture content infiltrates into the light adjustment layer.SOLUTION: In a light adjusting module, there is provided a light adjusting film in which one surface of one transparent base material on which transparent electrode layers vertically sandwiching a light adjustment layer are laminated adheres to a glass; a surface on the opposite side that does not adhere to the glass is removed to form a space at a position where a portion of the transparent base material is physically apart from the end surface of the transparent base material; a portion of the one transparent base material that does not adhere to the glass forms a penetrating space together with the transparent electrode layer at a position physically apart from the end surface of the transparent base material; a conductive part is taken out from the surface on the opposite side via the space; and the space is filled with a water-proof resin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a light control module having a light control layer that controls the light transmission state by electrical control. [Background technology]

[0002] The light control module is equipped with a light control film in which a light control layer (liquid crystal layer) is sandwiched between two transparent substrates on which transparent electrode layers are laminated, and is configured to be able to switch between an opaque state that scatters incident light and a transparent state that transmits incident light by changing the orientation state of the liquid crystal molecules contained in the liquid crystal layer using a voltage applied to the electrodes (see, for example, Patent Document 1). Here, light control film is sometimes expressed by different terms such as light control sheet or light control substrate, depending on whether the light control film is used in a flexible state or in a state in which the flexible light control film is attached to a rigid substrate to ensure thickness and rigidity. In this document, these terms will be uniformly referred to as "light control film." Furthermore, "light control module" refers to a state in which the electrode part and power supply part are included in the "light control film."

[0003] Light control modules that can switch between an opaque (or cloudy) state and a transparent state are used in a variety of applications. For example, by fixing them to a transparent and rigid substrate such as glass, they can be used in window glass, exhibition windows, partitions, etc. For example, the use of light control modules has been proposed as a facility for separating private and public spaces, as well as for windows, sunroofs, and sun visors in automobiles.

[0004] When a dimming module is placed at the boundary between indoors and outdoors or at the boundary between two spaces with a large temperature difference, moisture caused by rainwater, condensation, etc. may adhere to the dimming module. In such cases, if moisture penetrates into the dimming layer, the light transmittance adjustment function of the dimming module may be reduced.

[0005] More specifically, a dimming module is generally configured so that conductive parts such as FPCs for electrically connecting each transparent electrode layer to a power source extend from both the front and back surfaces. Therefore, when the dimming module is fixed to a transparent substrate such as glass as described above, one of the conductive parts is always located between the dimming module and the transparent substrate.

[0006] Therefore, when the dimming module is fixed to the transparent substrate, there is a risk that a gap corresponding to the thickness of the conductive part will occur between the dimming module and the transparent substrate. In other words, even if the dimming module and the transparent substrate are in close contact when fixed, external factors or factors over time can cause moisture to seep in from near the conductive part located between the dimming module and the transparent substrate, resulting in a problem of a reduction in the light transmittance variable function of the dimming module.

[0007] 3A and 3B are diagrams showing the glass-side electrode of a conventional dimming module. Fig. 3A shows a dimming module 100 bonded to glass 1. Fig. 3B is a cross-sectional view taken along the line Z-Z' of Fig. 3A, showing the configuration of the dimming module and details of how FPC 20 is connected to fourth transparent electrode layer 9 from below third transparent substrate 6.

[0008] More specifically, the third space 16 is an electrode portion that penetrates the third transparent substrate 6 and the third transparent electrode layer 7 and is formed by removing the edge 19 of the third transparent substrate 6 at a position physically separated from the edge 19, and the third conductive portion 13 indicates that an FPC 20 that connects to an external power source is inserted into the third space 16 and is connected to the fourth transparent electrode layer 9. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2020-112741 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above circumstances, and aims to provide a dimming module that reduces the phenomenon in which moisture such as rainwater or condensation penetrates the interior through the conductive part, reducing the variable light transmittance function of the dimming module. [Means for solving the problem]

[0011] The light control film of the first embodiment of the present invention has, in order from the adhesive surface that adheres to the glass, a first transparent substrate, a first transparent electrode layer, a light control layer, a second transparent electrode layer, and a second transparent substrate, a first conductive portion that electrically connects the first transparent electrode layer to an external electrode; a second conductive portion that electrically connects the second transparent electrode layer to the external power supply, the first conductive portion is taken out from a surface opposite to the adhesive surface via a first space that penetrates between the light control layer, the second transparent electrode layer, and the second transparent substrate, The second conductive portion is taken out from the surface opposite to the adhesive surface via a second space that penetrates the second transparent base material.

[0012] The light control film of the present invention is characterized in that at least one of the first space and the second space is sealed with a waterproof material.

[0013] The light control film of the present invention is characterized in that the waterproof material is physically separated from the sealing material on the edge of the light control film. [Effects of the Invention]

[0014] According to the present invention, a light control module is provided that effectively reduces the phenomenon in which moisture such as rainwater or condensation penetrates into the interior through the conductive part, reducing the variable light transmittance function of the light control module. [Brief explanation of the drawings]

[0015] [Figure 1] 10A and 10B are diagrams illustrating electrodes on the opposite side to the glass of the light control module according to the embodiment. [Figure 2]10A and 10B are diagrams illustrating a glass-side electrode of the light control module according to the embodiment. [Figure 3] FIG. 10 is a diagram showing a glass-side electrode of a conventional light control module. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dimming module of the embodiment has a configuration in which a dimming layer is sandwiched between a pair of transparent electrode layers. The vicinity of a pair of electrodes that electrically connect each transparent electrode layer to an external power source will be described with reference to separate drawings. Figure 1 shows the vicinity of the electrode on the opposite side of the glass of the dimming module in the embodiment.

[0017] FIG. 1(A) shows a dimming module 100 bonded to glass 1. FIG. 1(B) is a cross-sectional view taken along line X-X' in FIG. 1(A). The dimming module includes a first transparent substrate 2, a first transparent electrode layer 3 laminated on the first transparent substrate 2, a second transparent substrate 4, a second transparent electrode layer 5 laminated on the second transparent substrate 4, a dimming layer 10 sandwiched between the pair of transparent electrode layers 3 and 5, and a first space 14 and a first conductive portion 11 that constitute an electrode portion. The first conductive portion 11 includes an FPC 20 and solder (not shown). In FIG. 1(A), the first transparent substrate 2 is bonded to glass 1 via an adhesive 22.

[0018] In this embodiment, the first space 14 is a closed space provided within the surface of the second transparent substrate 4. The first space 14 forms a recess penetrating the second transparent substrate 4, the second transparent electrode layer 5, and the light-controlling layer 10. That is, the first transparent electrode layer 3 is exposed from the first space 14. The FPC 20 is connected to the first transparent electrode layer 3 within the first space 14. Here, the FPC 20 is flexible and extends to the first transparent electrode layer 3, following the inner wall of the first space 14. Furthermore, the connection surface of the FPC 20 with the first transparent electrode layer 3 is configured to have a larger area than the remaining region. Specifically, in this embodiment, the FPC 20 has a T-shape, with the connection surface being a wide rectangle. This ensures a large electrical connection surface between the FPC 20 and the first transparent electrode layer 3, thereby reducing heat generation due to current concentration. Furthermore, the T-shape of the FPC 20 facilitates handling of the FPC 20 when performing electrical connection within the first space 14. In other words, high-precision and reliable electrical connection is possible.

[0019] When the FPC 20 is electrically connected to the first transparent electrode layer 3, the first space 14 is filled with the waterproof material 17 without any gaps. The waterproof material 17 is also insulating and has the property of being liquid or gel-like when applied but solidifying over time. This not only improves the waterproofness around the first conductive portion 11 but also enhances protection against external pressure. Furthermore, even if the FPC 20 is displaced within the first space due to strong external traction, contact with the end face of the second transparent electrode layer 5 exposed in the first space 14 is effectively prevented because the periphery is covered with the waterproof material 17.

[0020] The entire edge of the light control module 100 is sealed with a sealant 20. This ensures that the edge of the light control layer 10 is covered and protected, and effectively prevents moisture from penetrating through the edge.

[0021] 2A and 2B are diagrams showing glass electrodes of a dimming module according to an embodiment. FIG. 2A shows a dimming module bonded to glass 1. FIG. 2B is a cross-sectional view taken along line Y-Y' in FIG. 2A. In FIG. 2, the same components as those described above are designated by the same reference numerals as in FIG. 1, and further description thereof will be omitted.

[0022] The light control module has a second space 15 that configures an electrode portion and a second conductive portion 12. The second conductive portion 12, like the first conductive portion 11, has an FPC 20, solder (not shown), and the like.

[0023] Like the first space 14, the second space 15 of this embodiment is a closed space provided within the surface of the second transparent substrate 4. However, as shown in FIG. 2(B), the second space 15 differs from the first space 14 in that it has an L-shaped cross section. More specifically, the second space 15 has an opening 15A for introducing the FPC 20 into the space and a chamber 15B with an L-shaped cross section. The second space 15 is formed, for example, by the following process. First, the second transparent substrate 4 is cut in one go from the height of the first transparent substrate 2 to the midpoint of the height of the first transparent substrate 2 using laser processing or the like. Then, a predetermined area of ​​the first transparent substrate 2, the first transparent electrode layer 3, and the light control layer 10 is removed in the direction in which the surface of the light control module expands. At this time, for convenience of processing, the second transparent substrate 4 and the second transparent electrode layer 5 laminated on the substrate 4 may be peeled back slightly as needed. This forms the L-shaped chamber 15B in which a predetermined area of ​​the second transparent electrode layer 5 is exposed.

[0024] The FPC 20 is introduced into the chamber 15B through the opening 15A. The opening 15A only needs to be wide enough to allow the T-shaped FPC to be properly introduced into the chamber 15B. However, if the width is increased more than necessary, new problems may arise, such as the filling operation with the waterproof material 17 becoming complicated or the design becoming less attractive. Therefore, it is desirable to limit the width of the opening 15A to at most the width of the portion of the FPC 20 that is located inside the chamber 15B.

[0025] The FPC 20 introduced into the chamber 15B is electrically connected to the second transparent electrode layer 5 via the solder or the like exposed in the chamber 15B. When the FPC 20 is electrically connected to the second transparent electrode layer 5, the second space 15 is filled without any gaps with the waterproof material 17. The effect of filling the entire second space 15 with the waterproof material 17 is the same as that of the first space 14 described above.

[0026] In this way, the second space 15 is sealed with the waterproof material 17 and is physically separated from the sealing material at the edge of the dimming module. This appropriately prevents the waterproof resin 17 from peeling off or being damaged together with the sealing material 18, even if, for example, expansion and contraction stress is applied to the edge of the dimming module.

[0027] As described above, the first conductive unit 11 is a member provided to supply power to the transparent electrode layer 3, which is closer to the glass surface of the pair of transparent electrode layers, in other words, the transparent electrode layer 3 farthest from the second transparent substrate 4 on the open side that is not fixed to any other substrate. The FPC 20 of the first conductive unit 11 is routed from the second transparent substrate 4 side and connected to an external power supply. The second conductive unit 12 is also extended from the second transparent substrate 4 side and connected to an external power supply. In other words, unlike conventional dimming modules, none of the conductive units are extended from the adhesive surface with the glass. Therefore, this embodiment effectively prevents a phenomenon in which moisture penetrates through gaps formed by the presence of a conductive unit at the adhesive surface between the glass 1 and the dimming module 100, resulting in a deterioration in quality.

[0028] Next, various materials and manufacturing methods used in the present invention will be described.

[0029] The transparent substrate in the present invention can be any substantially transparent flexible film substrate suitable for roll-to-roll manufacturing. Polyethylene terephthalate (PET) is preferably used, and the PET film may contain ultraviolet absorbers, stabilizers, etc.

[0030] The transparent electrode layer in the present invention can be made of any conventionally known transparent electrode material, such as indium tin oxide (ITO), a tin oxide conductive film, a zinc oxide conductive film, a polymer conductive film, etc. The transparent electrode layer can be formed by physical vapor deposition (PVD) methods such as vacuum deposition and sputtering, various chemical vapor deposition (CVD) methods, various coating methods, etc.

[0031] The light-controlling layer in the present invention is, for example, a polymer-dispersed liquid crystal (PDLC), which contains liquid crystal molecules and a polymer network made of a resin formed in a three-dimensional mesh shape, with the liquid crystal molecules held in the voids of the polymer network. The light-controlling layer may have other structures, such as a polymer-network liquid crystal (PNLC).

[0032] The liquid crystal molecules may be any conventionally known liquid crystal molecule, such as a nematic liquid crystal, a smectic liquid crystal, or a cholesteric liquid crystal. Among these, liquid crystal molecules with a high dielectric constant anisotropy and a large refractive index anisotropy are preferred, taking into consideration low-voltage operation and scattering characteristics. The liquid crystal molecules may have a functional group, such as an ethylene group, that is used in a polymerization reaction to form a polymer network.

[0033] The light-control layer can be either normal mode or reverse mode. In normal mode, the liquid crystal layer is in a transmissive state when a voltage is applied (ON) and in a scattering state when the voltage is removed (OFF). In reverse mode, the liquid crystal layer is in a transmissive state when the voltage is removed (OFF) and in a scattering state when the voltage is applied (ON).

[0034] When a reverse mode dimming layer is used in a dimming module, the dimming module has an alignment film (not shown) between each ITO and the dimming layer. The alignment film is selected to have a molecular orientation that exhibits a transparent state when the voltage is removed (OFF) depending on the alignment method of the dimming layer (TN method, VA method, IPS method, OCB method, etc.), and either a conventional horizontal alignment film or a vertical alignment film is used.

[0035] To manufacture a light-control module with a reverse-mode PDLC light-control layer, a mixture of liquid crystal and a photopolymerizable compound (monomer) is sandwiched between a pair of transparent electrode layers laminated on a transparent substrate. Then, by irradiating the liquid crystal with ultraviolet light under certain conditions, the photopolymerizable compound in the liquid crystal is converted into a polymer through photopolymerization. Through photopolymerization and cross-linking, a polymer network with countless microscopic domains (voids in the polymer) is formed in the liquid crystal.

[0036] On the other hand, when manufacturing a normal mode dimming module, instead of a transparent substrate having a transparent electrode layer and an alignment layer laminated in that order, a transparent substrate having a transparent electrode layer laminated thereon but no alignment layer laminated thereon is used, and the manufacturing process is carried out in the same manner.

[0037] The photochromic layer may contain spacers. By including spacers, it is possible to maintain a uniform thickness of the photochromic layer. The spacers are not particularly limited, but granular resin spacers, granular glass spacers, etc. can be preferably used.

[0038] As sealing materials and waterproof resins, various resin materials such as thermosetting, photosetting, moisture-curing, and anaerobic-curing types can be used in various resin systems such as epoxy resins, urethane resins, acrylic resins, vinyl acetate resins, ene-thiol resins, silicone resins, and modified polymers.

[0039] For example, when a PET film is used as the transparent substrate, a suitable method for forming a space that penetrates the transparent substrate at a position physically separated from the edge of the transparent substrate is to use a carbon dioxide laser with a wavelength of 10.63 μm (infrared), which is absorbed by PET film. By focusing the carbon dioxide laser with a focusing lens and irradiating the surface of the transparent substrate, the irradiated portion of the transparent substrate can be removed by heating, melting, decomposing, or incinerating it.

[0040] The glass used in the present invention may be any glass having high optical transparency in the visible light region, and may be inorganic or organic glass. Suitable inorganic glass includes, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, alkali-free glass, and quartz glass.

[0041] In the above embodiment, it has been explained that the FPC 20 is preferably T-shaped, but in the present invention, the FPC does not necessarily have to be T-shaped, and may be L-shaped or I-shaped. [Explanation of symbols]

[0042] 1: Glass 2: First transparent base material 3: First transparent electrode layer 4: Second transparent base material 5: Second transparent electrode layer 6: Third transparent base material 7: Third transparent electrode layer 8: Fourth transparent base material 9: Fourth transparent electrode layer 10: photochromic layer 11: First conductive part 12: Second conductive part 13: Third conductive part 14: First space 15:Second space 15A: Opening 15B: L-shaped cross section room 16: Third space 17: Waterproof material 18: Encapsulant 19. Edge (edge ​​surface) 20:FPC 21: Gap 22: Adhesive 100: Dimming module

Claims

1. The film has, in order from the bonding surface that is bonded to the glass, a first transparent substrate, a first transparent electrode layer, a light control layer, a second transparent electrode layer, and a second transparent substrate, a first conductive portion that electrically connects the first transparent electrode layer to an external power source; a second conductive portion that electrically connects the second transparent electrode layer to the external power supply, the first conductive portion is taken out from a surface opposite to the adhesive surface via a first space that penetrates between the light control layer, the second transparent electrode layer, and the second transparent substrate; the second conductive portion is taken out from the surface opposite to the adhesive surface via a second space penetrating the second transparent base material, the second space is an L-shaped space in a cross section perpendicular to the adhesive surface, the second space having a portion extending from the second transparent substrate to a portion of the first transparent substrate and a portion continuing from the portion and extending along the second transparent electrode layer, The second conductive portion is an FPC that is electrically connected to the second transparent electrode layer in a portion of the second space that extends along the second transparent electrode layer and is taken out along the second space. A light-controlling film characterized by:

2. At least one of the first space and the second space is sealed with a waterproof material. The light control film according to claim 1 .

3. The waterproof material is physically separated from the sealing material on the end surface of the light control film. The light control film according to claim 2 .

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