dimming window

Abstract

The dimming plate comprises: an adhesive layer attached to a transparent member; and a dimming layer attached to the transparent member TM via the adhesive layer, which has a transparent or opaque state depending on whether a voltage is applied to the dimming layer. At least one of the adhesive layer and the dimming layer contains a filter portion that absorbs a portion of the visible light spectrum. The transmittance of light in the wavelength range of 420 nm or less that penetrates the dimming window along a first direction from the dimming plate to the transparent member is 10% or less; and in light from a standard light source D65 that penetrates the dimming window along a second direction from the transparent member to the dimming plate, the yellowness YI as specified in JIS K 7373:2006 is 10 or less.

Description

[Technical Field]

[0001] This invention relates to a dimming window. [Previous Technology]

[0002] One example of a dimming sheet includes: a pair of transparent conductive films; a liquid crystal layer disposed between the transparent conductive films; and a functional layer disposed on the opposite side of the transparent conductive film from the liquid crystal layer. The dimming sheet is configured to have a relatively high haze state or a relatively low haze state depending on whether a voltage is applied to the dimming sheet. In the functional layer, the maximum transmittance in the wavelength range of 300 nm to 380 nm is 1% or less, and the yellowness YI is 0 to 10 or less. By having the functional layer described above, light degradation of the dimming sheet is suppressed, and yellowing of the dimming sheet is suppressed (see, for example, Patent Document 1 below). [Prior Art Documents] [Patent Documents]

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-45612 [Summary of the Invention]

[0004] [The problem the invention aims to solve]

[0005] Furthermore, the dimming sheet is a type of window glass used in building windows. This creates a dimming window equipped with both a dimming sheet and window glass. Regarding dimming windows, there may be instances where light from inside the building leaks out through the dimming sheet and transparent components, attracting insects to the window. Insect attraction is not only due to insects flying around the window, which detracts from its aesthetics, but also to insects that stick to the window after hitting it. Therefore, from the viewpoint of suppressing damage to the window's aesthetics, it is preferable to suppress the attraction of insects to the window. However, if suppressing insect attraction compromises the window's chroma, especially if the window has a yellowish tint, even if the attraction of insects is suppressed, the observer may still perceive the window itself as aesthetically unappealing. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the dimming window of the present invention includes a transparent member and a dimming sheet attached to the transparent member. The dimming sheet includes: an adhesive layer attached to the transparent member; and a dimming layer attached to the transparent member by means of the adhesive layer, which has a transparent state or an opaque state depending on whether a voltage is applied to the dimming layer. At least one of the adhesive layer and the dimming layer contains a filter that absorbs a portion of the visible light spectrum. The transmittance of light in the wavelength range of 420 nm or less that penetrates the dimming window along a first direction from the dimming sheet to the transparent member is 10% or less; and in the light of a standard light source D65 that penetrates the dimming window along a second direction from the transparent member to the dimming sheet, the yellowness YI as specified in JIS K 7373:2006 is 10 or less.

[0007] Insects have high visual sensitivity to the ultraviolet (UV) range. Specifically, the peak of an insect's visual sensitivity is approximately 360 nm, with a trough at approximately 250 nm and approximately 420 nm. Therefore, when the dimming sheet is attached to the exposed surface of the transparent component, the transmittance of light in the wavelength range below 420 nm that leaks from inside the house through the dimming window to the outside is less than 10%, thus inhibiting insects from being attracted to the exposed surface of the dimming window.

[0008] On the other hand, light in the wavelength range below 420nm contains blue and violet light from the visible light spectrum. Therefore, the light passing through the dimming window from inside the house to outside is prone to having a yellowish tint. Consequently, people staying inside the house may perceive the dimming window as having a yellowish tint. Regarding this point, the dimming window is constructed such that the yellowness YI of the light passing through the dimming window from outside to inside the house is 10 or less, thus suppressing the perception of a yellowish tint by people staying inside the house.

[0009] Alternatively, in the dimming window described above, when the dimming layer is in the aforementioned transparent state, the Y value of the aforementioned standard light source D65 that passes through the dimming window along the aforementioned second direction is 70% or more as specified in JIS Z 8781-1:2012.

[0010] According to the above-described dimming window, when the dimming sheet is attached to the exposed surface of the transparent member, the Y-value of the light penetrating from outside to inside through the dimming window is 70% or more. Therefore, it suppresses the situation where people staying inside the room feel that the dimming window is dark when looking at it. In addition, it suppresses the situation where it is difficult to see outside from inside the room.

[0011] Alternatively, in the aforementioned dimming window, the aforementioned adhesive layer contains an ultraviolet absorbing layer; the transmittance of light in the wavelength range below 380 nm that penetrates the aforementioned dimming window along the aforementioned second direction is 1% or less. According to this dimming window, light in the wavelength band below 380 nm incident on the dimming sheet is absorbed by the adhesive layer. This improves the lightfastness of the dimming layer.

[0012] Alternatively, in the dimming window described above, when the dimming layer is in the aforementioned transparent state and when it is in the aforementioned opaque state, the reflectivity of light in the wavelength range below 420nm incident along the aforementioned first direction into the dimming window is 10% or less.

[0013] According to the above-mentioned dimming window, when the dimming sheet is attached to the surface of the transparent member that is exposed inside the room, the reflectivity of light with high visual sensitivity of insects in the light that enters the dimming window from outside the room is low, thus further inhibiting insects from being attracted to the dimming window.

[0014] Alternatively, in the above-mentioned dimming window, the aforementioned transparent component may be formed of soda-lime glass. Alternatively, in the above-mentioned dimming window, the difference between the aforementioned yellowness YI obtained by subtracting the aforementioned yellowness YI obtained by the aforementioned dimming layer in the aforementioned opaque state from the aforementioned yellowness YI obtained by the aforementioned dimming layer in the aforementioned transparent state is 0.2 or less. According to this dimming window, since the difference in yellowness YI is 0.2 or less, it is possible to suppress the variation in the yellow tone of the dimming window caused by the difference in the state presented by the dimming layer. Alternatively, in the above-mentioned dimming window, the transmittance of light in the wavelength range of 620 nm or more incident along the aforementioned first direction into the aforementioned dimming window is 10% or less. According to this dimming window, it is easy to suppress the situation where a person staying in the room perceives the dimming window to have a yellow tone when viewing the dimming window from inside the room. Alternatively, in the above-mentioned dimming window, the aforementioned adhesive layer may be a filter portion. According to this dimming window, the adhesive layer can have both the function of attaching the dimming layer to the transparent member and the function of serving as a light filter. Alternatively, in the above-mentioned dimming window, the dimming layer may include a first transparent electrode layer, a second transparent electrode layer, and a liquid crystal layer located between the first and second transparent electrode layers; the liquid crystal layer serves as the light filter. According to this dimming window, the liquid crystal layer can have both the function of switching between a transparent state and an opaque state and the function of serving as a light filter. [Effects of the Invention]

[0015] According to the present invention, it is possible to suppress insects from being attracted by the dimming window and to suppress the yellow tone of the dimming window.

Implementation Method

[0017] [Form for implementing the invention]

[0018] Referring to Figures 1 to 22, one embodiment of the dimming window will be described. In addition, in this disclosure, the visible light band refers to the wavelength range above 380 nm and below 750 nm, and the ultraviolet region refers to the wavelength range below 380 nm.

[0019] [Structure] Referring to Figures 1 to 5, the structure of the dimming window will be described. As shown in Figure 1, the dimming window includes a dimming plate 10 and a transparent member TM. The transparent member TM is formed, for example, of soda-lime glass. Alternatively, the transparent member TM can also be formed of glass other than soda-lime glass, and is not limited to soda-lime glass. The transparent member TM can be formed, for example, of quartz glass, borosilicate glass, lead glass, fluoride glass, etc. The transparent member TM can also be formed of synthetic resin. When the transparent member TM is formed of synthetic resin, it is preferable that the transparent member TM has a gas barrier layer on the surface to which it is attached to the dimming plate 10. This suppresses the gas emitted from the transparent member TM from reaching the dimming plate 10.

[0020] The transparent component TM is installed on windows, doors, and roofs of various buildings. The transparent component TM can be flat or curved. The direction from the dimming strip 10 to the transparent component TM in the thickness direction of the dimming window is the first direction D1. The direction from the transparent component TM to the dimming strip 10 in the thickness direction of the dimming window is the second direction D2. The dimming strip 10 is attached to the interior surface of the building on one of the opposite sides of the transparent component TM. Therefore, the first direction D1 is the direction from the interior to the exterior of the building with the dimming window. In contrast, the second direction D2 is the direction from the exterior to the interior of the building with the dimming window.

[0021] The dimming sheet 10 is attached to the transparent component TM. The dimming sheet 10 includes an adhesive layer 11 and a dimming layer 12. The adhesive layer 11 is attached to the transparent component TM. The dimming layer 12 is attached to the transparent component TM via the adhesive layer 11. The dimming layer 12 has a transparent state or an opaque state depending on whether a voltage is applied to the dimming layer 12. At least one of the adhesive layer 11 and the dimming layer 12 contains a filter portion that absorbs a portion of the visible light spectrum. That is, only one of the adhesive layer 11 and the dimming layer 12 may contain a filter portion, or both the adhesive layer 11 and the dimming layer 12 may contain a filter portion.

[0022] Furthermore, the adhesive layer 11 may have a single-layer structure or a multi-layer structure. In the case where the adhesive layer 11 contains a filter element and has a single-layer structure, this layer functions as a filter element and has adhesiveness to the transparent member TM. In the case where the adhesive layer 11 contains a filter element and has a multi-layer structure, at least one layer of the adhesive layer 11 functions as a filter element. That is, only one layer of the adhesive layer 11 may function as a filter element, or two or more layers may function as filter elements. In this case, the layer functioning as a filter element and the adhesive layer may be different layers or the same layer.

[0023] The adhesive layer 11 may also contain an ultraviolet absorption layer. In the dimming window, the transmittance of light in the wavelength range below 380 nm that passes through the dimming window along the second direction D2 may be less than 1%. That is, the dimming window may be configured such that the transmittance of light in the wavelength range below 380 nm is less than 1% due to the ultraviolet absorption layer in the adhesive layer 11. In addition, the transmittance of light in the wavelength range below 380 nm that passes through the dimming window along the second direction D2 is the total transmittance. The total transmittance is measured by following the method in accordance with JIS K 7361-1:1997 "Plastic - Transparent material - Test method for total transmittance - Part 1: Single-beam method".

[0024] According to the dimming window described above, light with wavelengths below 380 nm incident on the dimming sheet 10 is absorbed by the adhesive layer 11. This improves the lightfastness of the dimming layer 12. Specifically, it suppresses the degradation of the liquid crystal layer and transparent substrate in the dimming layer 12 due to light with wavelengths below 380 nm. Furthermore, when the dimming sheet 10 is located indoors as described in this embodiment, light with wavelengths below 380 nm, i.e., ultraviolet light, is incident on the dimming sheet 10 from the second direction D2. The adhesive layer 11 is located between the transparent member TM and the dimming layer 12; therefore, light incident on the dimming sheet 10 along the second direction D2 is absorbed in the adhesive layer 11, thereby making it difficult for ultraviolet light to reach the dimming layer 12. Therefore, it is easy to suppress the degradation of the liquid crystal layer and transparent substrate contained in the dimming layer 12.

[0025] In the case where the adhesive layer 11 has a single-layer structure, this layer functions as an ultraviolet absorbing layer. In this case, the adhesive layer 11 functions as an ultraviolet absorbing component and has adhesiveness to the transparent member TM. In the case where the adhesive layer 11 has a multi-layer structure, at least one layer of the adhesive layer 11 functions as an ultraviolet absorbing layer. That is, only one layer of the adhesive layer 11 may function as a light-filtering component, or two or more layers may function as light-filtering components. In this case, the layer functioning as an ultraviolet absorbing layer and the adhesive layer may be different layers or the same layer.

[0026] In the case where the adhesive layer 11 has a single-layer structure, the adhesive layer 11 is formed of various transparent adhesives. The adhesive can be, for example, an optically clear adhesive (OCA). When the adhesive layer 11 functions as a filter, it can contain various colorants. The adhesive layer 11 may contain only one colorant or two or more colorants. When the adhesive layer 11 contains two or more colorants, it may contain a first colorant that absorbs light in a first wavelength band of the visible light band, and a second colorant that absorbs light in a second wavelength band of the visible light band that is different from the first wavelength band. The thickness of the adhesive layer 11 can be, for example, 10 μm or more and 75 μm or less. When the adhesive layer 11 is a filter as described above, it can have both the function of attaching the dimming layer 12 to the transparent member TM and the function of a filter. In addition, the adhesive layer 11 may also contain ultraviolet absorbers.

[0027] Furthermore, in the case where the adhesive layer 11 has a multilayer structure, the layer attached to the dimming layer 12 and the layer attached to the transparent member TM among the plurality of layers can be formed by the aforementioned transparent adhesive. In addition, the layer formed by the adhesive may contain an ultraviolet absorber, and layers different from those formed by the adhesive may also contain an ultraviolet absorber. Furthermore, the layer formed by the adhesive may contain the aforementioned colorant, and layers different from those formed by the adhesive may also contain a coloring agent.

[0028] Figures 2 to 4 show the structure of the dimming layer 12. As shown in Figure 2, the dimming layer 12 includes a first transparent electrode layer 21, a second transparent electrode layer 22, a liquid crystal layer 23, a first transparent substrate 24, and a second transparent substrate 25. In the thickness direction of the dimming layer 12, the liquid crystal layer 23 is located between the first transparent substrate 24 and the second transparent substrate 25. The first transparent substrate 24 supports the first transparent electrode layer 21. The second transparent substrate 25 supports the second transparent electrode layer 22. In the thickness direction of the dimming layer 12, the liquid crystal layer 23 is located between the first transparent electrode layer 21 and the second transparent electrode layer 22.

[0029] When the dimming layer 12 contains the aforementioned filter element and has the structure shown in FIG. 2, any one of the first transparent electrode layer 21, the second transparent electrode layer 22, the liquid crystal layer 23, the first transparent substrate 24, and the second transparent substrate 25 can function as a filter element. Furthermore, from the viewpoint of easily maintaining the function of each layer, it is preferable to configure at least one of the first transparent substrate 24 and the second transparent substrate 25 to function as a filter element. That is, it can be configured such that only one of the first transparent substrate 24 and the second transparent substrate 25 functions as a filter element, or it can be configured such that both the first transparent substrate 24 and the second transparent substrate 25 function as filter elements. In addition, the liquid crystal layer 23 can also be a filter element. In this case, the liquid crystal layer can have both the function of switching between a transparent state and an opaque state and the function of serving as a filter element.

[0030] The dimming layer 12 is of the normal type. That is, when a voltage is applied between the first transparent electrode layer 21 and the second transparent electrode layer 22, the dimming layer 12 is transparent. Conversely, when no voltage is applied between the first transparent electrode layer 21 and the second transparent electrode layer 22, the dimming layer 12 is opaque. The haze of the dimming layer 12 in the transparent state is lower than that in the opaque state. Furthermore, in this disclosure, the term "transparent state" refers to a state where the haze value of the dimming layer 12 is at its minimum and saturated. Conversely, the term "opaque state" refers to a state where the haze value of the dimming layer 12 is at its maximum and saturated. The haze is obtained by following the method in accordance with JIS K 7136:2000 "Plastics - Method for determining the haze of transparent materials".

[0031] The materials used to form the transparent electrode layers 21 and 22 may be, for example, any material selected from the group consisting of indium tin oxide, fluorine-doped tin oxide, tin oxide, zinc oxide, carbon nanotubes, poly(3,4-ethylenedioxythiophene), and silver. The thickness of each transparent electrode layer 21 and 22 may be, for example, 0.005 μm or more and 0.1 μm or less. This ensures proper driving of the dimming disc 10 and reduces the possibility of cracking when the dimming disc 10 flexes.

[0032] The liquid crystal layer 23 comprises a transparent resin layer and a liquid crystal composition. The resin layer contains a plurality of voids, or domains, formed within the resin layer. The liquid crystal composition fills the domains contained in the resin layer. The liquid crystal composition contains a plurality of liquid crystal molecules. An example of a liquid crystal molecule is any one selected from the group consisting of Schiff bases, azo compounds, azoxy compounds, biphenyl compounds, terphenyl compounds, benzoic acid esters, tolan compounds, pyrimidine compounds, cyclohexane carboxylic acid esters, phenylcyclohexane compounds, and dioxane compounds. The liquid crystal molecule is a positively type liquid crystal with positive dielectric anisotropy.

[0033] In addition to the liquid crystal molecules mentioned above, the liquid crystal composition system may also contain polymeric components for forming the resin layer, and dichroic pigments, etc. The polymeric components are monomers or oligomers that can polymerize under ultraviolet light. The resin layer is a polymer of the polymeric components. As described above, the polymeric components are monomers or polymers that can polymerize under ultraviolet light.

[0034] The materials forming each transparent substrate 24, 25 can be synthetic resins or inorganic compounds. Synthetic resins include, for example, polyesters, polyacrylates, polycarbonates, and polyolefins. Polyesters include, for example, polyethylene terephthalate and polyethylene naphthalate. Polyacrylates include, for example, polymethyl methacrylate. Inorganic compounds include, for example, silicon dioxide, silicon oxynitride, and silicon nitride. The thickness of each transparent substrate 24, 25 can be, for example, 16 μm or more and 250 μm or less. By having a thickness of 16 μm or more for the transparent substrates 24, 25, the processing and installation of the dimming sheet 10 is easier. By having a thickness of 250 μm or less for the transparent substrates 24, 25, the dimming sheet 10 can be manufactured using a roll-to-roll process.

[0035] As shown in FIG3, the dimming layer 12 may also include transparent electrode layers 21 and 22, liquid crystal layer 23, and a first filter portion 26 different from the transparent substrates 24 and 25. In the example shown in FIG3, the first filter portion 26 is located on the opposite side of the first transparent electrode layer 21 relative to the first transparent substrate 24.

[0036] The first filter section 26 may have a single-layer structure or a multi-layer structure. In addition, the first filter section 26 may also be located on the opposite side of the second transparent electrode layer 22 relative to the second transparent substrate 25.

[0037] The first filter section 26 is formed, for example, from a base material and a colorant. The base material may be, for example, a transparent synthetic resin. The first filter section 26 may also contain various colorants. The first filter section 26 may contain only one colorant or may contain two or more colorants. When the first filter section 26 contains two or more colorants, the first filter section 26 may contain a first colorant that absorbs light in a first wavelength band in the visible light band, and a second colorant that absorbs light in a second wavelength band in the visible light band that is different from the first wavelength band.

[0038] As shown in FIG4, the dimming layer 12 may also have a second filter 27, which is different from the first filter 26, in addition to the first filter 26 described above. In this case, the first filter 26 is located on the opposite side of the first transparent electrode layer 21 relative to the first transparent substrate 24, and the second filter 27 is located on the opposite side of the second transparent electrode layer 22 relative to the second transparent substrate 25.

[0039] As described above, the first filter section 26 may have a single-layer structure or a multi-layer structure. In addition, the second filter section 27, like the first filter section 26, may have a single-layer structure or a multi-layer structure.

[0040] The second filter section 27 is formed, for example, from a base material and a colorant. The base material may be, for example, a transparent synthetic resin. The second filter section 27 may also contain various colorants. The second filter section 27 may contain only one colorant or may contain two or more colorants. When the second filter section 27 contains two or more colorants, the second filter section 27 may contain a first colorant that absorbs light in the first wavelength band of the visible light band, and a second colorant that absorbs light in the second wavelength band of the visible light band that is different from the first wavelength band.

[0041] The wavelength band of the light absorbed by the first filter section 26 and the wavelength band of the light absorbed by the second filter section 27 may be the same or different from each other.

[0042] Furthermore, the type of the dimming layer 12 is not limited to the normal type described above, but can also be a reverse type. That is, when no voltage is applied between the first transparent electrode layer 21 and the second transparent electrode layer 22, the dimming layer 12 is transparent. Conversely, when voltage is applied between the first transparent electrode layer 21 and the second transparent electrode layer 22, the dimming layer 12 is opaque. The haze of the dimming layer 12 in the transparent state is lower than that in the opaque state.

[0043] FIG. 5 shows the structure of the opposite dimming layer 12. As shown in FIG. 5, in addition to the first transparent electrode layer 21, the second transparent electrode layer 22, the liquid crystal layer 23, the first transparent substrate 24, and the second transparent substrate 25, the dimming layer 12 also includes a first alignment layer 28 and a second alignment layer 29. In the thickness direction of the dimming layer 12, the first alignment layer 28 is located between the first transparent electrode layer 21 and the liquid crystal layer 23. In the thickness direction of the dimming layer 12, the second alignment layer 29 is located between the second transparent electrode layer 22 and the liquid crystal layer 23.

[0044] The first alignment layer 28 and the second alignment layer 29 are perpendicular alignment films. When no voltage is applied between the first transparent electrode layer 21 and the second transparent electrode layer 22, the liquid crystal molecules in the first alignment layer 28 are aligned such that the long axes of the liquid crystal molecules contained in the liquid crystal layer 23 are orthogonal to the surface of the first alignment layer 28. The liquid crystal molecules in the second alignment layer 29 are aligned such that the long axes of the liquid crystal molecules contained in the liquid crystal layer 23 are orthogonal to the surface of the second alignment layer 29.

[0045] The materials used to form each alignment layer 28, 29 are organic compounds, inorganic compounds, and mixtures of both. Organic compounds include, for example, polyimide, polyamide, polyvinyl alcohol, and cyanide compounds. Inorganic compounds include silicon oxide and zirconium oxide. Alternatively, the materials used to form alignment layers 28, 29 may also be polysilicon. Polysilicon is a compound possessing both inorganic and organic components. The thickness of each alignment layer 28, 29 may be, for example, 0.02 μm or more and 0.5 μm or less.

[0046] The liquid crystal molecules contained in the liquid crystal layer 23 are negatively charged liquid crystal molecules with negative dielectric anisotropy. Furthermore, the dimming sheet 10 may also have other functional layers besides the aforementioned adhesive layer 11 and dimming layer 12. These other functional layers may be, for example, an ultraviolet absorption layer and a hard coating layer. In the case where the dimming sheet 10 has functional layers, the functional layers may be located on the transparent substrate between the first transparent substrate 24 and the second transparent substrate 25 where the adhesive layer 11 is not provided.

[0047] [Optical Characteristics of the Dimming Window] The optical characteristics of the dimming window disclosed herein will be explained below. The dimming window satisfies the following conditions 1 and 2. (Condition 1) The transmittance of light in the wavelength range below 420 nm that passes through the dimming window along the first direction D1 is 10% or less. (Condition 2) In the light of the standard light source D65 that passes through the dimming window along the second direction D2, the yellowness YI as specified by JIS K 7373:2006 is 10 or less.

[0048] In other words, the transmittance of light in the wavelength range below 420 nm that passes through the dimming window from inside the room to outside is 10% or less. Furthermore, the transmittance is the total transmittance and is measured according to the method described in JIS K 7361-1:1997. Additionally, when the dimming layer 12 is opaque, the yellowness YI of the standard light source D65 that passes through the dimming window from outside to inside is 10 or less.

[0049] Insects have high visual sensitivity to the ultraviolet region. Specifically, the peak of the insect's visual sensitivity has a top of about 360 nm and bottoms at about 250 nm and about 420 nm. Therefore, by ensuring that the transmittance of light in the wavelength range below 420 nm in the light leaking from inside the house to outside through the dimming window is less than 10%, the insects are prevented from being attracted to the exposed surface of the house through the dimming window.

[0050] On the other hand, light in the wavelength range below 420nm contains blue and violet light from the visible light band, so the light passing through the dimming window from inside the house to outside is prone to having a yellowish tint. Therefore, people staying inside the house are likely to perceive the dimming window as having a yellowish tint when they look at it. Regarding this point, the dimming window with dimming disc 10 disclosed herein is configured such that the yellowness YI of the light passing through the dimming window from outside to inside the house is 10 or less, thus suppressing the situation where people staying inside the house perceive the dimming window as having a yellowish tint.

[0051] The standard light source D65 is specified in JIS Z 8720:2012 "Standard light for color measurement and standard light source". The yellowness YI of condition 2 is the value calculated by the calculation method specified in JIS K 7373:2006 "Plastics - Method for determining yellowness and yellowing".

[0052] It is preferable that the dimming window system satisfies at least one of the following conditions 3 to 6. That is, the dimming window system may satisfy only one of conditions 3 to 6, or it may satisfy two or more of conditions 3 to 6. (Condition 3) When the dimming layer 12 is transparent, the Y value of the standard light source D65 that passes through the dimming window along the second direction D2 is 70% or more as specified in JIS Z 8781-1:2012.

[0053] (Condition 4) When the dimming layer 12 is in a transparent state and when it is in an opaque state, the reflectivity of light in the wavelength range below 420 nm incident along the first direction D1 into the dimming window is 10% or less. (Condition 5) The difference between the yellowness YI when the dimming layer 12 is in an opaque state and the yellowness YI when the dimming layer 12 is in a transparent state is 0.2 or less. (Condition 6) The transmittance of light in the wavelength range above 620 nm incident along the first direction D1 into the dimming window is 10% or less.

[0054] By satisfying condition 3 through the dimming window, the Y-value of light penetrating from outside to inside through the dimming window is 70% or more. Therefore, the situation where people staying inside feel that the dimming window is dark when looking at it is suppressed. In addition, the situation where it is difficult to see outside from inside the house is also suppressed.

[0055] By satisfying condition 4 through the dimming window, the reflectivity of light with high visual sensitivity to insects in the light shining from outside into the dimming sheet 10 is low, thus further suppressing insects from being attracted to the dimming window. By satisfying condition 5 through the dimming window, the difference value of yellowness YI is less than 0.2, thus suppressing the variation in the yellow tone of the dimming window caused by the difference in the state presented by the dimming layer 12. By satisfying condition 6 through the dimming window, it is easy to suppress the perception of a yellow tone in the dimming window when a person staying inside views it from inside.

[0056] The Y value of condition 3 is calculated using the calculation method specified in JIS Z 8781-1:2012 "Colorimetry - Part 1: CIE Colorimetric Standard Observer's Color Matching Function". The transmittance of condition 6 is the total light transmittance and is measured according to the method described above in JIS K 7361-1:1997. In the case where the dimming window satisfies condition 1 above, the filter section of the dimming window may contain a colorant as described above. The colorant may be a colorant that has an absorption wavelength band in the wavelength range below 420 nm. The filter section may contain only one colorant or may contain two or more colorants. The colorant may, for example, be one or more selected from the group consisting of trihydric compounds, diphenyl ketone compounds, benzotriazole compounds, and cyanoacrylate compounds. That is, the filter section may contain only one of the compounds selected from this group or may contain two or more. Furthermore, when the filter contains two or more colorants, the filter may contain two or more colorants contained in compounds of the same system, or it may contain colorants contained in compounds of the first system and colorants contained in compounds of the second system different from the first system. In addition, when the dimming window satisfies condition 6 above, the filter provided by the dimming window may contain a colorant. The colorant may be a colorant having an absorption wavelength band in the wavelength range of 620 nm or higher. The filter may contain only one colorant or may contain two or more. The colorant may be, for example, a colored colorant; furthermore, a colored colorant may be, for example, a blue pigment. The blue pigment may be, for example, a monoazo blue pigment, a methine or polymethine blue pigment. Furthermore, the colorant may be, for example, an infrared absorber. Infrared absorbers can be, for example, anthocyanin compounds, phthalocyanine compounds, squartzium compounds, croconium compounds, diimmonium compounds, perylene compounds, and pyrrolopyrrole compounds. When the dimming window satisfies condition 6, the filter section of the dimming window can contain both a colorant and an infrared absorber. Furthermore, when the liquid crystal layer 23 is a filter section, the resin layer contained in the liquid crystal layer 23 can also contain the aforementioned colorants.

[0057] [Example] Referring to Figures 6 to 22 and Tables 1 to 4, the embodiments and comparative examples will be described. Figures 6, 8, 10, 12, 14, 16, 18, 20, and 22 in Figures 6 to 22 respectively show the transmittance spectrum of the dimming window. The transmittance in the transmittance spectrum is the total light transmittance. In each figure, the spectrum when the normal dimming window is opaque and the voltage applied to the dimming layer is 0V is represented by a solid line, and the spectrum when the normal dimming window is transparent and the voltage applied to the dimming layer is 40V is represented by a dashed line. Furthermore, the spectrum when the opposite dimming window is transparent and the voltage applied to the dimming layer is 0V is represented by a chain line, and the spectrum when the opposite dimming window is opaque and the voltage applied to the dimming layer is 40V is represented by a two-dot chain line.

[0058] In contrast, Figures 7, 9, 11, 13, 15, 17, 19, and 21 respectively show the transmittance spectra of the first filter portion of the dimming window. Figure 6 shows the transmittance spectra of the dimming windows of Comparative Examples 1-1 and 2-1. Figure 7 shows the transmittance spectra of the first filter portion of the dimming window of Comparative Examples 1-3 and 2-1, and Figure 8 shows the transmittance spectra of the dimming windows of Comparative Examples 1-3 and 2-1. Figure 9 shows the transmittance spectra of the first filter portion of the dimming window of Examples 1-1 and 2-2, and Figure 10 shows the transmittance spectra of the dimming windows of Examples 1-1 and 2-2.

[0059] Figure 11 shows the transmittance spectrum of the first filter portion of the dimming window in Comparative Examples 1-5 and 2-4; Figure 12 shows the transmittance spectrum of the dimming window in Comparative Examples 1-5 and 2-4; Figure 13 shows the transmittance spectrum of the first filter portion of the dimming window in Examples 1-2 and 2-3; Figure 14 shows the transmittance spectrum of the dimming window in Examples 1-2 and 2-3.

[0060] Figure 15 shows the transmittance spectrum of the first filter portion of the dimming window in Comparative Examples 1-7 and 2-6, and Figure 16 shows the transmittance spectrum of the dimming window in Comparative Examples 1-7 and 2-6. Figure 17 shows the transmittance spectrum of the first filter portion of the dimming window in Examples 1-3 and 2-4, and Figure 18 shows the transmittance spectrum of the dimming window in Examples 1-3 and 2-4.

[0061] Figure 19 shows the transmittance spectrum of the first filter portion of the dimming window in Comparative Examples 1-9 and 2-8, and Figure 20 shows the transmittance spectrum of the dimming window in Comparative Examples 1-9 and 2-8. Figure 21 shows the transmittance spectrum of the first filter portion of the dimming window in Examples 1-4 and 2-5, and Figure 22 shows the transmittance spectrum of the dimming window in Examples 1-4 and 2-5.

[0062] [Normal Type Dimming Window] Regarding the transparent component, a plate component made of soda-lime glass with a thickness of 3 mm is prepared. Furthermore, regarding the dimming sheet, a normal type dimming sheet is prepared, consisting of an adhesive layer containing an ultraviolet absorber and a dimming layer. Additionally, regarding the dimming layer, a dimming layer comprising a liquid crystal layer, a pair of transparent electrode layers, a pair of transparent substrates, an ultraviolet absorbing layer, and a hard coating layer is prepared. One of the transparent substrates is attached to the transparent component via an adhesive layer, and the aforementioned ultraviolet absorbing layer is deposited on the other transparent substrate, and a hard coating layer is deposited on the ultraviolet absorbing layer.

[0063] Furthermore, regarding the liquid crystal layer, a liquid crystal layer containing a plurality of domains and wherein the domains are filled with a liquid crystal composition is prepared. Furthermore, regarding the pair of transparent electrode layers, a transparent electrode layer formed of ITO is prepared. Furthermore, regarding the transparent substrate, a transparent substrate formed of PET is prepared.

[0064] A plurality of first filters are designed, and the optical characteristics of a normal-type dimming window having each first filter are calculated by simulation. The wavelength range absorbed by each dimming window and the lightfastness of the dimming window are as shown in Table 1 below. In addition, in the embodiments and comparative examples described below, the dimming window of Comparative Example 1-1 does not have a first filter. In contrast, the dimming windows of the comparative examples other than Comparative Example 1-1, and the dimming windows of all embodiments, have a first filter.

[0065] [Table 1] Absorption wavelength Lightfastness When opaque No yellowing Penetration rate below 1% Penetration rate below 10% ≤380nm short wavelength side Long wavelength side Comparative Example 1-1 ○ ≤405nm - ○ Comparative Examples 1-2 ○ ≦415nm - ○ Comparative Examples 1-3 ○ ≦420nm - ○ Actual example 1-1 ○ ≦420nm ≧655nm ○ Comparative Examples 1-4 ○ ≦425nm - ○ Comparative Examples 1-5 ○ ≦425nm ≧680nm ○ Actual example 1-2 ○ ≦425nm ≧640nm ○ Comparative Examples 1-6 ○ ≦430nm - ○ Comparative Examples 1-7 ○ ≦430nm ≧650nm ○ Actual example 1-3 ○ ≦430nm ≧640nm ○ Comparative Examples 1-8 ○ ≦435nm - ○ Comparative Examples 1-9 ○ ≦435nm ≧640nm ○ Actual example 1-4 ○ ≦435nm ≧625nm ○ Actual example 1-5 × ≤420nm ≥655nm ×

[0066] As shown in Table 1 above, it was confirmed that the transmittance of the dimming windows in Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-9 in the wavelength range below 380 nm was 1% or less. Therefore, in the dimming windows of Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-9, ultraviolet light is suppressed from entering the dimming window, thereby suppressing yellowing of the dimming film.

[0067] Furthermore, the dimming windows of Comparative Examples 1-2 to 1-4, 1-6, and 1-8, compared to the dimming window of Comparative Example 1-1, incorporate a first filter that absorbs only light in the short-wavelength side of the visible light band. This confirms that the dimming windows of Comparative Examples 1-2 to 1-4, 1-6, and 1-8 have a transmittance of 10% or less in the short-wavelength side of the visible light band. For example, it was confirmed that the dimming window of Comparative Example 1-3 exhibits the transmittance spectrum shown in FIG8 by having a first filter that displays the transmittance spectrum shown in FIG7.

[0068] In contrast, the dimming windows of Comparative Examples 1-5, 1-7, and 1-9, compared to the dimming window of Comparative Example 1-1, combine a first filter section that absorbs light in both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band. This confirms that the dimming windows of Comparative Examples 1-5, 1-7, and 1-9 have a transmittance of 10% or less for both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band.

[0069] For example, it was confirmed that the dimming window of Comparative Examples 1-5 displays the transmittance spectrum shown in FIG12 by having a first filter unit that displays the transmittance spectrum shown in FIG11. Furthermore, it was confirmed that the dimming window of Comparative Examples 1-7 displays the transmittance spectrum shown in FIG16 by having a first filter unit that displays the transmittance spectrum shown in FIG15. Furthermore, it was confirmed that the dimming window of Comparative Examples 1-9 displays the transmittance spectrum shown in FIG20 by having a first filter unit that displays the transmittance spectrum shown in FIG19.

[0070] On the other hand, the dimming windows of Examples 1-1 to 1-5, compared to the dimming window of Comparative Example 1-1, combine a first filter section that absorbs light in both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band. This confirms that the transmittance of the dimming windows of Examples 1-1 to 1-5 for both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band is 10% or less.

[0071] For example, it was confirmed that the dimming window of Embodiment 1-1 displays the transmittance spectrum shown in FIG10 by having a first filter unit that displays the transmittance spectrum shown in FIG9. It was confirmed that the dimming window of Embodiment 1-2 displays the transmittance spectrum shown in FIG14 by having a first filter unit that displays the transmittance spectrum shown in FIG13. It was confirmed that the dimming window of Embodiment 1-3 displays the transmittance spectrum shown in FIG18 by having a first filter unit that displays the transmittance spectrum shown in FIG17. It was confirmed that the dimming window of Embodiment 1-4 displays the transmittance spectrum shown in FIG22 by having a first filter unit that displays the transmittance spectrum shown in FIG21.

[0072] In each normal dimming window, the transmittance for light in the wavelength range below 420nm, the yellowness YI of the dimming window, the Y value of the dimming window, and the reflectance for light in the wavelength range below 420nm are as shown in Table 2 below.

[0073] [Table 2] Light penetrates (indoors → outdoors) Light penetrates (from outside to inside). Reflected light (outdoor→outdoor) When opaque When transparent When opaque When transparent When opaque When transparent 420nm Yellowness Yellowness Y value ≤420nm ≤10 ≤10 ≤10 ≤10 Comparative Example 1-1 × × 10.9 4.6 85.4 ○ ○ Comparative Examples 1-2 × × 11.8 5.6 72.6 ○ ○ Comparative Examples 1-3 ○ ○ 13.5 7.6 72.6 ○ ○ Actual example 1-1 ○ ○ 9.1 3.1 71.6 ○ ○ Comparative Examples 1-4 ○ ○ 16.1 10.4 72.6 ○ ○ Comparative Examples 1-5 ○ ○ 15.6 9.9 72.5 ○ ○ Actual example 1-2 ○ ○ 8.2 2.6 70.9 ○ ○ Comparative Examples 1-6 ○ ○ 19.8 14.5 72.5 ○ ○ Comparative Examples 1-7 ○ ○ 15.3 10.0 71.6 ○ ○ Actual example 1-3 ○ ○ 9.5 4.3 70.3 ○ ○ Comparative Examples 1-8 ○ ○ 24.9 19.9 72.5 ○ ○ Comparative Examples 1-9 ○ ○ 14.7 9.9 72.5 ○ ○ Examples 1-4 ○ ○ 8.2 3.4 68.8 ○ ○ Examples 1-5 ○ ○ 9.1 3.1 71.6 ○ ○

[0074] As shown in Table 2 above, in the dimming windows of Examples 1-1 to 1-5 and Comparative Examples 1-3 to 1-9, regardless of the state of the dimming window, the transmittance of light in the wavelength range below 420 nm is less than 10%. Therefore, insect attraction is suppressed in both the transparent and opaque states. In contrast, in the dimming windows of Comparative Examples 1-1 and 1-2, regardless of the state of the dimming window, the transmittance of light in the wavelength range below 420 nm exceeds 10%. Therefore, insects are attracted in both the transparent and opaque states.

[0075] On the other hand, in the dimming windows of Comparative Examples 1-3 to 1-9, the yellowness YI exceeds 10 when the dimming window is in an opaque state or in a transparent state. Therefore, in the dimming windows of Comparative Examples 1-3 to 1-9, a person inside the room is likely to perceive the dimming window as having a yellowish tint. In contrast, in the dimming windows of Examples 1-1 to 1-5, the yellowness YI is 10 or less regardless of the state of the dimming window. Therefore, in the dimming windows of Examples 1-1 to 1-5, the perception of a yellowish tint by a person inside the room is suppressed.

[0076] Furthermore, in the dimming windows of Examples 1-1 to 1-3 and 1-5, when the dimming window is in a transparent state, the Y-value of the standard light incident from outside into the room is 70% or more. In contrast, in the dimming window of Example 1-4, when the dimming window is in a transparent state, the Y-value of the standard light incident from outside into the room does not reach 70%. Therefore, according to the dimming windows of Examples 1-1 to 1-3 and 1-5, compared to the dimming window of Example 1-4, the perception of the dimming window being dark is reduced when a person inside the room looks at the dimming window.

[0077] In the dimming windows of Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-9, the reflectance of light entering the dimming window from outside in the wavelength range of 420 nm and below is 10% or less. Therefore, the light reflected from the dimming window is suppressed, thus attracting insects to the dimming window.

[0078] [Reverse-type dimming window] Regarding the transparent component, a plate component made of soda-lime glass with a thickness of 3 mm is prepared. Furthermore, regarding the dimming sheet, a reverse-type dimming sheet is prepared, consisting of an adhesive layer containing an ultraviolet absorber and a dimming layer. Additionally, regarding the dimming layer, a dimming layer comprising a liquid crystal layer, a pair of alignment layers, a pair of transparent electrode layers, a pair of transparent substrates, an ultraviolet absorbing layer, and a hard coating layer is prepared. One of the transparent substrates is attached to the transparent component via the adhesive layer, and the aforementioned ultraviolet absorbing layer is deposited on the other transparent substrate, and a hard coating layer is deposited on the ultraviolet absorbing layer.

[0079] Furthermore, regarding the liquid crystal layer, a liquid crystal layer comprising a plurality of regions and wherein each region is filled with a liquid crystal composition is prepared. Furthermore, regarding the pair of transparent electrode layers, a transparent electrode layer formed of ITO is prepared. Furthermore, regarding the transparent substrate, a transparent substrate formed of PET is prepared. Furthermore, regarding the pair of alignment layers, an alignment layer formed of polyimide is prepared.

[0080] A plurality of first filters were designed, and the optical characteristics of a dimming window with opposite types of each first filter were calculated by simulation. The wavelength range absorbed by each dimming window and the lightfastness of the dimming window are as shown in Table 3 below. In addition, in the embodiments and comparative examples described below, the dimming window of Comparative Example 2-1 does not have a first filter. In contrast, the dimming windows of the comparative examples other than Comparative Example 2-1, and the dimming windows of all embodiments, have a first filter.

[0081] In addition, as shown in Table 3 below, each of the opposite dimming windows has the same first filter as the first filter of one of the normal dimming windows described above.

[0082] [Table 3] The same First filter section Absorption wavelength Lightfastness When opaque No yellowing Penetration rate below 1% Penetration rate below 10% ≤380nm short wavelength side Long wavelength side Comparative Example 2-1 Comparative Example 1-1 ○ ≤405nm - ○ Comparative Example 2-2 Comparative Examples 1-2 ○ ≤415nm - ○ Example 2-1 Comparative Examples 1-3 ○ ≤420nm - ○ Example 2-2 Example 1-1 ○ ≤420nm ≥655nm ○ Comparative Examples 2-3 Comparative Examples 1-4 ○ ≤425nm - ○ Comparative Examples 2-4 Comparative Examples 1-5 ○ ≤425nm ≥680nm ○ Example 2-3 Examples 1-2 ○ ≤425nm ≥640nm ○ Comparative Examples 2-5 Comparative Examples 1-6 ○ ≤430nm - ○ Comparative Examples 2-6 Comparative Examples 1-7 ○ ≤430nm ≥650nm ○ Examples 2-4 Examples 1-3 ○ ≤430nm ≥640nm ○ Comparative Examples 2-7 Comparative Examples 1-8 ○ ≤435nm - ○ Comparative Examples 2-8 Comparative Examples 1-9 ○ ≤435nm ≥640nm ○ Examples 2-5 Examples 1-4 ○ ≤435nm ≥625nm ○ Examples 2-6 Examples 1-5 × ≤420nm ≥655nm ×

[0083] As shown in Table 3 above, it was confirmed that the transmittance of the dimming windows in Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-8 in the wavelength range below 380 nm is 1% or less. Therefore, in the dimming windows of Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-8, ultraviolet light is suppressed from entering the dimming window, thereby suppressing yellowing of the dimming film.

[0084] Furthermore, the dimming windows of Comparative Examples 2-2, 2-3, 2-5, and 2-7, compared to the dimming window of Comparative Example 2-1, incorporate a first filter section that absorbs only light in the short-wavelength side of the visible light band. This confirms that the dimming windows of Comparative Examples 2-2, 2-3, 2-5, and 2-7 have a transmittance of less than 10% for light in the short-wavelength side of the visible light band.

[0085] On the other hand, the dimming window of Example 2-1, compared to the dimming window of Comparative Example 2-1, incorporates a first filter that absorbs only light in the short-wavelength side wavelength range of the visible light band. This confirms that the dimming window of Example 2-1 has a transmittance of 10% or less for light in the short-wavelength side wavelength range of the visible light band. For example, it is confirmed that the dimming window of Example 2-1 displays the transmittance spectrum shown in FIG8 by having a first filter that displays the transmittance spectrum shown in FIG7.

[0086] In contrast, the dimming windows of Comparative Examples 2-4, 2-6, and 2-8, compared to the dimming window of Comparative Example 2-1, combine a first filter section that absorbs light in both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band. This confirms that the dimming windows of Comparative Examples 2-4, 2-6, and 2-8 have a transmittance of 10% or less for both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band.

[0087] For example, it was confirmed that the dimming window of Comparative Examples 2-4 displays the transmittance spectrum shown in FIG12 by having a first filter unit that displays the transmittance spectrum shown in FIG11. Furthermore, it was confirmed that the dimming window of Comparative Examples 2-6 displays the transmittance spectrum shown in FIG16 by having a first filter unit that displays the transmittance spectrum shown in FIG15. Furthermore, it was confirmed that the dimming window of Comparative Examples 2-8 displays the transmittance spectrum shown in FIG20 by having a first filter unit that displays the transmittance spectrum shown in FIG19.

[0088] On the other hand, the dimming windows of Examples 2-2 to 2-6, compared to the dimming window of Comparative Example 2-1, combine a first filter section that absorbs light in both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band. This confirms that the transmittance of the dimming windows of Examples 2-2 to 2-6 for both the short-wavelength side wavelength range and the long-wavelength side wavelength range of the visible light band is 10% or less.

[0089] For example, it was confirmed that the dimming window of Embodiment 2-2 displays the transmittance spectrum shown in FIG10 by having a first filter unit that displays the transmittance spectrum shown in FIG9. It was confirmed that the dimming window of Embodiment 2-3 displays the transmittance spectrum shown in FIG14 by having a first filter unit that displays the transmittance spectrum shown in FIG13. It was confirmed that the dimming window of Embodiment 2-4 displays the transmittance spectrum shown in FIG18 by having a first filter unit that displays the transmittance spectrum shown in FIG17. It was confirmed that the dimming window of Embodiment 2-5 displays the transmittance spectrum shown in FIG22 by having a first filter unit that displays the transmittance spectrum shown in FIG21.

[0090] In each type of dimming window, the transmittance for light in the wavelength range below 420nm, the yellowness YI of the dimming window, the Y value of the dimming window, and the reflectance for light in the wavelength range below 420nm are as shown in Table 4 below.

[0091] [Table 4] Light penetrates (indoors → outdoors) Light penetrates (from outside to inside). Reflected light (outdoor→outdoor) When opaque When transparent When opaque When transparent When opaque When transparent 420nm Yellowness Yellowness Y value ≤420nm ≤10 ≤10 ≤10 ≤10 Comparative Example 2-1 × × 5.4 5.2 86.5 ○ ○ Comparative Example 2-2 × × 6.4 6.2 73.5 ○ ○ Example 2-1 ○ ○ 8.3 8.1 73.5 ○ ○ Example 2-2 ○ ○ 3.9 3.7 72.6 ○ ○ Comparative Examples 2-3 ○ ○ 11.1 10.9 73.5 ○ ○ Comparative Example 2-4 ○ ○ 10.6 10.5 73.4 ○ ○ Actual example 2-3 ○ ○ 3.4 3.2 71.8 ○ ○ Comparative Example 2-5 ○ ○ 15.2 15.0 73.5 ○ ○ Comparative Example 2-6 ○ ○ 10.7 10.6 72.5 ○ ○ Actual example 2-4 ○ ○ 5.0 4.8 71.2 ○ ○ Comparative Example 2-7 ○ ○ 20.5 20.4 73.4 ○ ○ Comparative Example 2-8 ○ ○ 10.5 10.4 73.4 ○ ○ Actual example 2-5 ○ ○ 4.1 3.9 69.7 ○ ○ Examples 2-6 ○ ○ 8.3 8.1 73.5 ○ ○

[0092] As shown in Table 4 above, in the dimming windows of Examples 2-1 to 2-6 and Comparative Examples 2-3 to 2-8, regardless of the state of the dimming window, the transmittance of light in the wavelength range below 420 nm is less than 10%. Therefore, insect attraction is suppressed in both the transparent and opaque states. In contrast, in the dimming windows of Comparative Examples 2-1 and 2-2, regardless of the state of the dimming window, the transmittance of light in the wavelength range below 420 nm exceeds 10%. Therefore, insects are attracted in both the transparent and opaque states.

[0093] On the other hand, in the dimming windows of Comparative Examples 2-3 to 2-8, regardless of the state of the dimming window, the yellowness YI exceeded 10. Therefore, in the dimming windows of Comparative Examples 2-3 to 2-8, when a person inside the room looks at the dimming window, the dimming window is likely to be perceived as having a yellow tint. In contrast, in the dimming windows of Examples 2-1 to 2-6, regardless of the state of the dimming window, the yellowness YI was 10 or less. Therefore, in the dimming windows of Examples 2-1 to 2-6, the situation where a person inside the room perceives the dimming window as having a yellow tint is suppressed.

[0094] Furthermore, in the dimming windows of Examples 2-1 to 2-4 and 2-6, when the dimming window is in a transparent state, the Y-value of the standard light incident from outside into the room is 70% or more. In contrast, in the dimming window of Example 2-5, when the dimming window is in a transparent state, the Y-value of the standard light incident from outside into the room does not reach 70%. Therefore, according to the dimming windows of Examples 2-1 to 2-4 and 2-6, compared to the dimming window of Example 2-5, the perception of the dimming window being dark is reduced when a person inside the room looks at the dimming window.

[0095] In the dimming windows of Examples 2-1 to 2-6 and Comparative Examples 2-1 to 2-8, the reflectance of light entering the dimming window from outside in the wavelength range of 420 nm and below is 10% or less. Therefore, the light reflected from the dimming window is suppressed, thus attracting insects to the dimming window.

[0096] As described above, according to one embodiment of the dimming sheet, the following effects can be obtained. (1) The transmittance of light in the wavelength range below 420nm in the light leaking from inside the house to outside through the dimming window is 10% or less, thereby inhibiting insects from being attracted to the exposed surface of the dimming window.

[0097] (2) The light passing through the dimming window from inside the house to outside has a yellow tint YI of 10 or less, thus suppressing the feeling of yellow tint from the dimming window to the occupants inside the house.

[0098] (3) The Y value of the light penetrating from outside to inside through the dimming window is 70% or more, thus suppressing the situation where people staying inside feel that the dimming window is dark when they look at it. In addition, it suppresses the situation where it is difficult to see outside from inside the house.

[0099] (4) The light that insects are visually sensitive to when it shines into the dimming window 10 from outside has a low reflectivity, thus further suppressing the situation where insects are lured to the dimming window. [Simplified Explanation of the Diagram]

[0016] Figure 1 is a cross-sectional view schematically showing the structure of the dimming window. Figure 2 is a cross-sectional view schematically showing a first example of the structure of the dimming layer provided by the dimming sheet shown in Figure 1. Figure 3 is a cross-sectional view schematically showing a second example of the structure of the dimming layer provided by the dimming sheet shown in Figure 1. Figure 4 is a cross-sectional view schematically showing a third example of the structure of the dimming layer provided by the dimming sheet shown in Figure 1. Figure 5 is a cross-sectional view schematically showing a fourth example of the structure of the dimming layer provided by the dimming sheet shown in Figure 1. Figure 6 is a graph showing the transmittance spectrum of the dimming window of Comparative Example 1-1 and Comparative Example 2-1. Figure 7 is a graph showing the transmittance spectrum of the first filter portion provided by the dimming window of Comparative Example 1-3 and Example 2-1. Figure 8 is a graph showing the transmittance spectrum of the dimming window of Comparative Example 1-3 and Example 2-1. Figure 9 is a graph showing the transmittance spectrum of the first filter portion provided by the dimming window of Example 1-1 and Example 2-2. Figure 10 is a graph showing the transmittance spectra of the dimming windows of Examples 1-1 and 2-2. Figure 11 is a graph showing the transmittance spectra of the first filter portion of the dimming windows of Comparative Examples 1-5 and 2-4. Figure 12 is a graph showing the transmittance spectra of the dimming windows of Comparative Examples 1-5 and 2-4. Figure 13 is a graph showing the transmittance spectra of the first filter portion of the dimming windows of Examples 1-2 and 2-3. Figure 14 is a graph showing the transmittance spectra of the dimming windows of Examples 1-2 and 2-3. Figure 15 is a graph showing the transmittance spectra of the first filter portion of the dimming windows of Comparative Examples 1-7 and 2-6. Figure 16 is a graph showing the transmittance spectra of the dimming windows of Comparative Examples 1-7 and 2-6. Figure 17 is a graph showing the transmittance spectra of the first filter portion of the dimming windows of Examples 1-3 and 2-4. Figure 18 is a graph showing the transmittance spectra of the dimming windows of Examples 1-3 and Examples 2-4. Figure 19 is a graph showing the transmittance spectra of the first filter portion of the dimming windows of Comparative Examples 1-9 and Comparative Examples 2-8. Figure 20 is a graph showing the transmittance spectra of the dimming windows of Comparative Examples 1-9 and Comparative Examples 2-8. Figure 21 is a graph showing the transmittance spectra of the first filter portion of the dimming windows of Examples 1-4 and Examples 2-5. Figure 22 is a graph showing the transmittance spectra of the dimming windows of Examples 1-4 and Examples 2-5.

Claims

1. A dimming window comprising: a transparent member; and a dimming sheet attached to the transparent member; the dimming sheet comprising: an adhesive layer attached to the transparent member; and a dimming layer attached to the transparent member via the adhesive layer, and having a transparent or opaque state depending on whether a voltage is applied to the dimming layer; at least one of the adhesive layer and the dimming layer includes a filter portion that absorbs a portion of light in the visible light band; the transmittance of light in the wavelength range of 420 nm or less penetrating the dimming window along a first direction from the dimming sheet to the transparent member is 10% or less; and in light from a standard light source D65 penetrating the dimming window along a second direction from the transparent member to the dimming sheet, the yellowness YI as specified in JIS K 7373:2006 is 10 or less. When the aforementioned dimming layer is in the aforementioned transparent state, the Y value of the aforementioned standard light source D65 that penetrates the aforementioned dimming window along the aforementioned second direction is 70% or more as specified in JIS Z 8781-1:2012.

2. The dimming window of claim 1, wherein the aforementioned adhesive layer contains an ultraviolet absorption layer; the transmittance of light in the wavelength range below 380 nm that passes through the aforementioned dimming window along the aforementioned second direction is less than 1%.

3. The dimming window of claim 1, wherein, in both the aforementioned dimming layer being in the aforementioned transparent state and the aforementioned opaque state, the reflectivity of light in the wavelength range of 420 nm or less incident along the aforementioned first direction into the aforementioned dimming window is 10% or less.

4. The dimming window as claimed in claim 1, wherein the aforementioned transparent component is made of soda-lime glass.

5. The dimming window of claim 1, wherein the difference between the yellowness YI obtained by subtracting the yellowness YI when the dimming layer is in the aforementioned opaque state from the yellowness YI when the dimming layer is in the aforementioned transparent state is 0.2 or less.

6. The dimming window of claim 1, wherein the transmittance of light in the wavelength range of 620 nm and above incident along the first direction into the dimming window is 10% or less.

7. The dimming window as claimed in claim 1, wherein the aforementioned adhesive layer is the aforementioned filter portion.

8. The dimming window of claim 1, wherein the dimming layer comprises a first transparent electrode layer, a second transparent electrode layer, and a liquid crystal layer located between the first transparent electrode layer and the second transparent electrode layer; the liquid crystal layer is the aforementioned filter portion.

Images