Lighting control film

Abstract

To aim at improvement of a degree of freedom in an electrode arrangement.SOLUTION: A lighting control film 100 includes: a first transparent conductive film; a second transparent conductive film arranged facing the first transparent conductive film in a thickness direction; a lighting control layer arranged between the first transparent conductive film and the second transparent conductive film in the thickness direction; a first electrode disposed at the first transparent conductive film; and a second electrode disposed at the second transparent conductive film. The lighting control layer has an opening at a portion other than a periphery of the lighting control film. At least one of the first electrode and the second electrode is arranged inside the opening.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a light management film. [Background technology]

[0002] BACKGROUND ART Conventionally, a light control film including a first transparent conductive film, a light control layer, and a second transparent conductive film has been known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-101206 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional light control films, electrodes are arranged on the outer periphery of the film when viewed in the thickness direction of the film. An object of the present invention is to provide a light control film that allows for greater freedom in electrode arrangement. [Means for solving the problem]

[0005] The light-control film of the present invention comprises a first transparent conductive film, a second transparent conductive film arranged opposite the first transparent conductive film in the thickness direction, a light-control layer arranged between the first transparent conductive film and the second transparent conductive film in the thickness direction, a first electrode provided on the first transparent conductive film, and a second electrode provided on the second transparent conductive film, and an opening is formed in the light-control layer in a part other than the outer periphery of the light-control film, and at least one of the first electrode and the second electrode is arranged within the opening. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a light control film that allows for improved freedom in electrode placement. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a bottom view illustrating the light control film according to the first embodiment. [Figure 2] 1 is a partial cross-sectional view illustrating a light control film according to a first embodiment. [Figure 3] FIG. 10 is a bottom view illustrating a light control film according to a second embodiment. [Figure 4] FIG. 10 is a bottom view illustrating a light control film according to a third embodiment. [Figure 5] FIG. 10 is a bottom view illustrating a light control film according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, a light control film according to an embodiment will be described with reference to the accompanying drawings. In this specification and drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[0009] [Light control film 100 according to the first embodiment] FIG. 1 is a plan view illustrating a light control film 100 according to a first embodiment. FIG. 2 is a partial cross-sectional view illustrating a light control film 100 according to a first embodiment. FIG. 2 shows a cross section taken along line II-II in FIG. 1. In addition, each figure shows arrows indicating the X-axis direction, Y-axis direction, and Z-axis direction, which intersect with each other. The Z-axis direction is along the thickness direction of the light control film 100.

[0010] The light control film 100 includes a first transparent conductive film 10, a second transparent conductive film 20, a PDLC layer 30, and an electrode section 40. The first transparent conductive film 10 and the second transparent conductive film 20 may have the same configuration or different configurations. The PDLC layer 30 is disposed between the first transparent conductive film 10 and the second transparent conductive film 20 in the Z-axis direction. The PDLC layer 30 is an example of a light control layer.

[0011] [First transparent conductive film 10] The first transparent conductive film 10 has a first surface 11 and a second surface 12 that face each other in the Z-axis direction. The second surface 12 is the surface closer to the PDLC layer 30 in the Z-axis direction. The first surface 11 is the surface farther from the PDLC layer 30 in the Z-axis direction. The thickness of the first transparent conductive film 10 is, for example, 5 μm to 200 μm, and more preferably 5 μm to 70 μm.

[0012] The surface resistance value of the first transparent conductive film 10 is, for example, preferably 0.1 Ω / □ to 1000 Ω / □, more preferably 0.5 Ω / □ to 300 Ω / □, and particularly preferably 1 Ω / □ to 200 Ω / □.

[0013] The haze value of the first transparent conductive film 10 is preferably 20% or less, more preferably 10% or less, and even more preferably 0.1% to 5%.

[0014] The total light transmittance of the first transparent conductive film 10 is preferably 30% or more, more preferably 60% or more, and particularly preferably 80% or more.

[0015] The first transparent conductive film 10 can be formed using a metal oxide such as indium tin oxide (ITO), zinc oxide (ZnO), or tin oxide (SnO). Alternatively, the first transparent conductive film 10 can be formed of a metal nanowire such as silver nanowire (AgNW), carbon nanotube (CNT), an organic conductive film, a metal layer, or a laminate thereof. The first transparent conductive film 10 can be patterned into a desired shape depending on the purpose.

[0016] [Second transparent conductive film 20] The second transparent conductive film 20 has a first surface 21 and a second surface 22 that face each other in the Z-axis direction. The first surface 21 is the surface closer to the PDLC layer 30 in the Z-axis direction. The second surface 22 is the surface farther from the PDLC layer 30 in the Z-axis direction. The thickness of the second transparent conductive film 20 is preferably 5 μm to 200 μm, and more preferably 5 μm to 70 μm.

[0017] The surface resistance value of the second transparent conductive film 20 is preferably 0.1 Ω / □ to 1000 Ω / □, more preferably 0.5 Ω / □ to 300 Ω / □, and particularly preferably 1 Ω / □ to 200 Ω / □.

[0018] The haze value of the second transparent conductive film 20 is preferably 20% or less, more preferably 10% or less, and even more preferably 0.1% to 5%.

[0019] The total light transmittance of the second transparent conductive film 20 is preferably 30% or more, more preferably 60% or more, and particularly preferably 80% or more.

[0020] The second transparent conductive film 20 can be formed using a metal oxide such as indium tin oxide (ITO), zinc oxide (ZnO), or tin oxide (SnO2). Alternatively, the first transparent conductive layer can be formed using a metal nanowire such as silver nanowire (AgNW), or carbon nanotube (CNT). The second transparent conductive layer may be formed of an organic conductive film, a metal layer, or a laminate thereof. The film can be patterned into a desired shape depending on the purpose.

[0021] As the material for forming the second transparent substrate, for example, the materials listed as the materials for forming the first transparent conductive film 10 can be used.

[0022] [PDLC layer 30] The PDLC layer 30 is disposed between the second surface 12 of the first transparent conductive film 10 and the first surface 21 of the second transparent conductive film 20 in the Z-axis direction.

[0023] The PDLC layer 30 contains a liquid crystal compound. The PDLC layer 30 containing the liquid crystal compound is formed by dispersing the liquid crystal compound in a resin matrix. In the light-controlling layer, the degree of orientation of the liquid crystal compound can be changed depending on whether or not a voltage is applied, thereby switching between a transmission mode and a scattering mode. In one embodiment, the layer is in the transmission mode when a voltage is applied, and in the scattering mode (normal mode) when no voltage is applied.

[0024] In the light control film 100 of this embodiment, when no voltage is applied, the liquid crystal compound is not oriented and is in the scattering mode, and when voltage is applied, the liquid crystal compound is oriented and is in the transmission mode. In another embodiment, the film is in the scattering mode when voltage is applied and in the transmission mode when no voltage is applied (reverse mode). In this embodiment, the liquid crystal compound is oriented when no voltage is applied, and the oriented liquid crystal compound exhibits approximately the same refractive index as the resin matrix, resulting in the transmission mode. On the other hand, when voltage is applied, the orientation of the liquid crystal compound is disrupted and the film is in the scattering mode.

[0025] Examples of the PDLC layer 30 include a light control layer containing a polymer dispersed liquid crystal and a light control layer containing a polymer network liquid crystal. A polymer dispersed liquid crystal has a structure in which the liquid crystal is phase-separated within the polymer. A polymer network liquid crystal has a structure in which the liquid crystal is dispersed in a polymer network, and the liquid crystal in the polymer network has a continuous phase.

[0026] Any suitable non-polymerizable liquid crystal compound can be used as the liquid crystal compound. Examples include nematic, smectic, and cholesteric liquid crystal compounds. It is preferable to use a nematic liquid crystal compound because it can achieve excellent transparency in the transmission mode. Examples of the nematic liquid crystal compound include biphenyl-based compounds, phenylbenzoate-based compounds, cyclohexylbenzene-based compounds, azoxybenzene-based compounds, azobenzene-based compounds, azomethine-based compounds, terphenyl-based compounds, biphenylbenzoate-based compounds, cyclohexylbiphenyl-based compounds, phenylpyridine-based compounds, cyclohexylpyrimidine-based compounds, and cholesterol-based compounds.

[0027] The content of the liquid crystal compound in the PDLC layer 30 is, for example, 30% to 70%, preferably 35% to 65%, and more preferably 40% to 60%.

[0028] The resin forming the resin matrix constituting the PDLC layer 30 can be appropriately selected depending on the light transmittance, the refractive index of the liquid crystal compound, and the like. The resin is typically an active energy ray-curable resin, and preferred examples include liquid crystal polymers, (meth)acrylic resins, silicone resins, epoxy resins, fluorine-based resins, polyester resins, and polyimide resins. The resin forming the resin matrix constituting the PDLC layer 30 may be a thermoplastic resin such as a urethane resin, polyvinyl alcohol resin, polyethylene resin, polypropylene resin, or acrylic resin. The thermoplastic resin is preferably a water-soluble or water-dispersible resin. Only one type of resin may be used for forming the polymer matrix, or two or more types may be used in combination.

[0029] The content of the resin matrix in the PDLC layer 30 is, for example, 30% to 70% by weight, preferably 35% to 65% by weight, and more preferably 40% to 60% by weight. If the content of the polymer matrix is ​​within this range, it is possible to obtain effects such as a good light control function at a moderate operating voltage, good mechanical strength, and prevention of liquid crystal leakage from the edges.

[0030] The PDLC layer 30 containing a liquid crystal compound can be formed by any appropriate method. For example, the PDLC layer 30 can be obtained by applying a light-controlling layer-forming composition to the transparent electrode layer side of one substrate to form a coating layer, laminating the other substrate on the coating layer with the transparent electrode layer facing the other substrate to form a laminate a, and curing the coating layer. In this case, the light-controlling layer-forming composition contains, for example, a monomer for forming a resin matrix (preferably, an active energy ray-curable monomer) and a liquid crystal compound.

[0031] [Electrode section 40] The electrode section 40 has a first electrode 50 and a second electrode 60. The first electrode 50 is provided on the first transparent conductive film 10, and the second electrode 60 is provided on the second transparent conductive film 20. The first electrode 50 is electrically connected to the first transparent conductive film 10, and the second electrode 60 is electrically connected to the second transparent conductive film 20.

[0032] The first electrode 50 includes a first pad 51 bonded to the second surface 12 of the first transparent conductive film 10. The second electrode 60 includes a second pad 61 bonded to the first surface 21 of the second transparent conductive film 20. The first pad 51 and the second pad 61 may be conductive metal thin films.

[0033] Opening As shown in FIG. 2, an opening 33 is formed in the PDLC layer 30. The opening 33 penetrates the PDLC layer 30 in the Z-axis direction. An opening 23 is formed in the second transparent conductive film 20. The opening 23 penetrates the second transparent conductive film 20 in the Z-axis direction. An opening 13 is formed in the first transparent conductive film 10. The opening 13 penetrates the first transparent conductive film 10 in the Z-axis direction. At least a portion of the opening 33 and the opening 23 are formed to overlap each other when viewed in the Z-axis direction. The openings 33, 23, and 13 are circular when viewed in the Z-axis direction. The shapes of the openings 33, 23, and 13 are not limited to circular, and may be rectangular or another shape.

[0034] The openings 33, 23, and 13 are formed in portions other than the outer periphery 110 of the light control film 100. The outer periphery 110 is the outer periphery (edge) in a planar view. The opening 33 is not formed in a position that overlaps with the outer periphery of the PDLC layer 30. The opening 33 is formed inside the outer periphery 110. The opening 23 is not formed in a position that overlaps with the outer periphery of the second transparent conductive film 20. The opening 23 is formed inside the outer periphery 110. The opening 13 is not formed in a position that overlaps with the outer periphery of the first transparent conductive film 10. The opening 13 is formed inside the outer periphery 110.

[0035] The first electrode 50 and the second electrode 60 are disposed in the opening 33. The first pad 51 is provided on the second surface 12 of the first transparent conductive film 10 exposed in the opening 33. The second pad 61 is provided on the first surface 21 of the second transparent conductive film 20 exposed in the opening 33.

[0036] [1st wiring 52] A first wiring 52 is connected to the first pad 51. The first wiring 52 passes through the opening 33 and the opening 23 and is led out to the outside of the light control film 100. The first wiring 52 may be welded to the first pad 51.

[0037] [Second wiring 62] A second wiring 62 is connected to the second pad 61. The second wiring 62 passes through the opening 33 and the opening 23 and is led out to the outside of the light control film 100. The second wiring 62 may be welded to the second pad 61.

[0038] [Actions and Effects of the Light Control Film 100 According to the First Embodiment] The light-controlling film 100 of the first embodiment comprises a first transparent conductive film 10, a second transparent conductive film 20 arranged opposite the first transparent conductive film 10 in the thickness direction, a PDLC layer 30 arranged between the first transparent conductive film 10 and the second transparent conductive film 20 in the thickness direction, a first electrode 50 provided on the first transparent conductive film 10, and a second electrode 60 provided on the second transparent conductive film 20, and an opening 33 is formed in the PDLC layer 30 in a portion other than the outer periphery 110 of the light-controlling film 100, and at least one of the first electrode 50 and the second electrode 60 is arranged within the opening 33.

[0039] In such a light control film 100, at least one of the first electrode 50 and the second electrode 60 is disposed in a portion other than the outer peripheral portion 110 of the light control film 100, thereby improving the degree of freedom in arranging the electrodes.

[0040] For example, in the case of a narrow bezel or when the outer periphery of the light control film 100 is exposed, it may not be possible to place an electrode on the outer periphery. In the light control film 100 according to this embodiment, at least one of the first electrode 50 and the second electrode 60 is placed in a portion other than the outer periphery 110.

[0041] [Light control film 100B according to the second embodiment] Next, a light control film 100B according to a second embodiment will be described. FIG. 3 is a bottom view illustrating the light control film 100B according to the second embodiment. The light control film 100B according to the second embodiment shown in FIG. 3 differs from the light control film 100 according to the first embodiment shown in FIG. 1 in that the light control film 100B according to the second embodiment shown in FIG. 3 includes an electrode part 40B instead of the electrode part 40. Note that in the description of the second embodiment, explanations similar to those of the first embodiment may be omitted.

[0042] The electrode section 40B of the light control film 100B has a first electrode 50 and a second electrode 60. A rectangular opening 33B is formed in the PDLC layer 30. A rectangular opening is formed in the second transparent conductive film 20. The first electrode 50 and the second electrode 60 are disposed in the rectangular opening.

[0043] The light control film 100B according to the second embodiment has the same effects as the light control film 100 according to the first embodiment. The shape of the opening where the first electrode 50 and the second electrode 60 are arranged may be rectangular. The shape of the opening may be changed depending on where the light control film 100B is arranged. The light control film 100B can be realized with improved design.

[0044] [Light control film 100C according to the third embodiment] Next, a light control film 100C according to a third embodiment will be described. FIG. 4 is a bottom view illustrating a light control film 100B according to the third embodiment. The light control film 100C according to the third embodiment shown in FIG. 4 differs from the light control film 100B according to the second embodiment shown in FIG. 3 in that the light control film 100C according to the third embodiment shown in FIG. 4 includes electrode portion 40C and electrode portion 40D instead of electrode portion 40B. Note that in the description of the third embodiment, explanations similar to those of the first and second embodiments may be omitted.

[0045] The electrode section 40C of the light control film 100C has a first electrode 50, and the electrode section 40D has a second electrode 60. The electrode section 40C and the electrode section 40D are arranged, for example, spaced apart in the X-axis direction and the Y-axis direction. The first electrode 50 and the second electrode 60 are arranged spaced apart in the X-axis direction and the Y-axis direction.

[0046] A rectangular opening (first opening) 33C and an opening (second opening) 33D are formed in the PDLC layer 30. A plurality of rectangular openings are formed in the second transparent conductive film 20. The rectangular openings 33C and 33D are spaced apart in the X-axis direction and the Y-axis direction. The first electrode 50 is disposed inside the opening 33C, and the second electrode 60 is disposed in the opening 33D.

[0047] The light control film 100C according to the third embodiment also achieves the same effects as the light control film 100 according to the above embodiment. The first electrode 50 and the second electrode 60 may be disposed in different openings 33C, 33D. The first electrode 50 and the second electrode 60 are disposed apart in the X-axis direction and the Y-axis direction. The light control film 100C has improved freedom in the arrangement of the first electrode 50 and the second electrode 60.

[0048] [Light control film 100D according to the fourth embodiment] Next, a light control film 100D according to a fourth embodiment will be described. FIG. 5 is a bottom view illustrating the light control film 100D according to the fourth embodiment. The light control film 100D according to the fourth embodiment shown in FIG. 5 differs from the light control film 100C according to the third embodiment shown in FIG. 4 in that the light control film 100D according to the fourth embodiment shown in FIG. 5 includes an electrode part 40E instead of the electrode part 40D. Note that in the description of the fourth embodiment, explanations similar to those of the first to third embodiments may be omitted.

[0049] The electrode unit 40E of the light control film 100D has a second electrode 60. The electrode unit 40C and the electrode unit 40E are arranged, for example, spaced apart in the X-axis direction and the Y-axis direction. The first electrode 50 and the second electrode 60 are arranged, for example, spaced apart in the X-axis direction and the Y-axis direction.

[0050] The electrode section 40E is formed so as to protrude outward from the PDLC layer 30 when viewed in the Z-axis direction. The electrode section 40E may be formed on the outer periphery 110 of the light control film 100D.

[0051] The light control film 100D according to the fourth embodiment also achieves the same effects as the light control film 100 according to the above embodiment. At least one of the first electrode 50 and the second electrode 60 may be formed on the outer periphery 110 of the light control film 100D. At least one of the first electrode 50 and the second electrode 60 does not have to be disposed in the opening 33C of the PDLC layer 30. In the light control film 100D, the degree of freedom in the arrangement of the first electrode 50 and the second electrode 60 is improved. The second electrode 60 may be disposed in the opening 33C, and the first electrode 50 may be disposed on the outer periphery 110.

[0052] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form.

[0053] The light control film 100 may be configured to include, for example, three or more electrodes (first electrode 50, second electrode 60). In such a configuration, at least one of the first electrode 50 and the second electrode 60 may be disposed in an opening formed in a portion other than the outer periphery 110.

[0054] The first wiring 52 and the second wiring 62 may be led out from different surfaces of the light control film 100. In the light control film 100, the opening 13 formed in the first transparent conductive film 10 and the opening 23 formed in the second transparent conductive film 20 may be located at different positions in the X-axis direction and the Y-axis direction. The first wiring 52 and the second wiring 62 may be led out in different directions from different openings. [Explanation of symbols]

[0055] 100, 100B, 100C, 100D: Light control film 10 First transparent conductive film 20 Second transparent conductive film 30 PDLC layer (light control layer) 33, 33B Opening (opening of light control layer) 33C Opening (opening of light control layer, first opening) 33D Opening (opening of photochromic layer, second opening) 40 Electrode section 50 1st electrode 51 First Pad 52 1st wiring 60 2nd electrode 61 Second Pad 62 2nd wiring XX axis direction YY axis direction ZZ axis direction (thickness direction)

Claims

1. a first transparent conductive film; a second transparent conductive film disposed opposite to the first transparent conductive film in a thickness direction; a light-controlling layer disposed between the first transparent conductive film and the second transparent conductive film in the thickness direction; a first electrode provided on the first transparent conductive film; a second electrode provided on the second transparent conductive film, The light-control layer has an opening formed in a portion other than the outer periphery of the light-control film, A light-control film in which at least one of the first electrode and the second electrode is disposed within the opening.

2. The light control film according to claim 1 , wherein both the first electrode and the second electrode are disposed within the opening.

3. a first opening and a second opening are formed in the light-controlling layer as the openings, The first electrode is formed in the first opening, The light control film according to claim 1 , wherein the second electrode is formed in the second opening.

4. The light control film according to claim 1 , wherein the opening has a circular shape when viewed in the thickness direction.

5. The light control film according to claim 1 , wherein the opening has a rectangular shape when viewed in the thickness direction.

6. the first transparent conductive film includes a first surface and a second surface that are opposite to each other in the thickness direction, the second transparent conductive film includes a first surface and a second surface that are opposite to each other in the thickness direction, the light-controlling layer is disposed between the second surface of the first transparent conductive film and the first surface of the second transparent conductive film in the thickness direction; the first electrode includes a first pad formed on the second surface of the first transparent conductive film; The light control film according to claim 1 , wherein the second electrode includes a second pad formed on the first surface of the second transparent conductive film.

7. an opening is formed in the second transparent conductive film at a position overlapping the opening in the light-controlling layer when viewed in the thickness direction; The light-controlling film of claim 1, wherein the first wiring connected to the first electrode and the second wiring connected to the second electrode pass through the opening of the light-controlling layer and the opening of the second transparent conductive film and are led out to the outside of the light-controlling film.

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