Dimming sheet and method for manufacturing dimming sheet

Abstract

A dimming sheet (11) is provided with two transparent base material layers each provided with an electrode layer (14F) and an electrode layer (14B), and a dimming layer (12) located between the two transparent base material layers. The light control layer (12) is provided with a transparent resin layer that partitions the voids, a liquid crystal composition that fills the voids, and a spacer that defines the thickness of the light control layer. The external haze of each transparent base material layer in the light control sheet (11) is less than 0.1%, and the internal haze of each transparent base material layer in the light control sheet (11) is 0.1% to 2.0%. As a result, uniform visibility of the dimming sheet (11) in the plane can be obtained.

Description

Technical Field

[0001] The present disclosure relates to a light-adjusting sheet having a transparent state and an opaque state, and a method for manufacturing the light-adjusting sheet. Background Art

[0002] The dimming sheet has a transparent resin layer that divides the gaps and a liquid crystal composition that fills the gaps. The change in voltage applied to the transparent resin layer changes the orientation state of the liquid crystal compound, thereby changing the refractive index difference between the transparent resin layer and the liquid crystal composition. The dimming sheet changes from an opaque state to a transparent state by reducing the refractive index difference between the transparent resin layer and the liquid crystal composition. The dimming sheet changes from a transparent state to an opaque state by increasing the refractive index difference between the transparent resin layer and the liquid crystal composition (for example, refer to Patent Document 1). The dimming sheet has a spacer in the transparent resin layer. The spacer prevents the thickness of the transparent resin layer from becoming thinner.

[0003] The first example of the spacer contains polymethyl methacrylate resin. Polymethyl methacrylate resin can improve the durability of the liquid crystal composition by suppressing the elution of free radicals containing aromatic rings (see, for example, Patent Document 2).

[0004] The second example of the spacer has more than two peaks in the size distribution. The haze value in the opaque state and the linear transmittance in the transparent state have a trade-off relationship in which one increases while the other decreases. For example, when the haze value in the opaque state increases due to the increase in the spacer, the linear transmittance in the transparent state decreases. A dimming sheet having more than two peaks in the size distribution expands the design freedom of the dimming sheet so as to weaken the trade-off relationship (for example, refer to Patent Document 3).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-45135

[0008] Patent Document 2: Japanese Patent No. 7047885

[0009] Patent Document 3: Japanese Patent Application Publication No. 2021-009188 Summary of the invention

[0010] Technical problem to be solved by the invention

[0011] On the other hand, the structural difference between the transparent resin layer and the spacer, as well as the refractive index difference between the transparent resin layer and the spacer, contribute to the scattering of light. The scattering generated at the interface between the transparent resin layer and the spacer is different from the scattering generated at the interface between the transparent resin layer and the liquid crystal composition. The scattering generated at the interface between the transparent resin layer and the spacer makes the presence of the spacer obvious whether in a transparent state or an opaque state. In particular, when the spacers are unevenly present in the transparent resin layer, the scattering generated at the interface between the transparent resin layer and the spacer makes the collection of spacers obvious when observing the dimming sheet. Whether in the first or second example mentioned above, the presence of spacers in the structure is obvious, and uneven visibility through the dimming sheet will be generated within the surface of the dimming sheet.

[0012] Means for solving technical problems

[0013] The dimming sheet for solving the above technical problem comprises two transparent substrate layers each having an electrode layer and a dimming layer located between the two transparent substrate layers, wherein the dimming layer comprises a transparent resin layer dividing a gap, a liquid crystal composition filling the gap, and a spacer determining the thickness of the dimming layer. In the dimming sheet, the external haze of each transparent substrate layer is less than 0.1%, and the internal haze of each transparent substrate layer is greater than 0.1% and less than 2.0%.

[0014] The dimming sheet for solving the above technical problem comprises two transparent substrate layers each having an electrode layer and a dimming layer located between the two transparent substrate layers, wherein the dimming layer comprises a transparent resin layer dividing a gap, a liquid crystal composition filling the gap, and a spacer determining the thickness of the dimming layer. In the dimming sheet, the external haze of each transparent substrate layer is less than 0.1%, and the sum of the internal haze of the two transparent substrate layers is greater than 0.2% and less than 4.0%.

[0015] The method for manufacturing a dimming sheet for solving the above technical problem comprises the following steps: a step of coating a coating liquid for forming the dimming layer between the two transparent substrate layers each having an electrode layer; and a step of forming the dimming layer by curing the coating liquid, wherein the dimming layer comprises a transparent resin layer for dividing a gap, a spacer buried in the transparent resin layer, and a liquid crystal composition for filling the gap. In the method for manufacturing a dimming sheet, the external haze of each transparent substrate layer in the dimming sheet is less than 0.1%, and the internal haze of each transparent substrate layer is greater than 0.1% and less than 2.0%.

[0016] The method for manufacturing a dimming sheet for solving the above technical problem comprises the following steps: a step of coating a coating liquid for forming the dimming layer between the two transparent substrate layers each having an electrode layer; and a step of forming the dimming layer by curing the coating liquid, wherein the dimming layer comprises a transparent resin layer for dividing a gap, a spacer buried in the transparent resin layer, and a liquid crystal composition for filling the gap. In the method for manufacturing a dimming sheet, the external haze of each transparent substrate layer in the dimming sheet is less than 0.1%, and the sum of the internal haze of the two transparent substrate layers is greater than 0.2% and less than 4.0%.

[0017] The external haze of the transparent substrate layer originates from the concavo-convex existing in the surface of the transparent substrate layer. According to the above-mentioned configurations, the external haze of the transparent substrate layer is less than 0.1%. Therefore, if the surface of the transparent substrate layer is an electrode layer, the electric field acting between the two transparent substrate layers can suppress the imbalance originating from the concavo-convex. If the surface of the transparent substrate layer is an orientation layer, the imbalance in the orientation control force acting between the two transparent substrate layers can be suppressed.

[0018] The internal haze of the transparent substrate layer originates from the refractive index difference scattered inside the transparent substrate layer. According to the above-mentioned structures, the internal haze of the transparent substrate layer is 0.1% or more. Alternatively, the sum of the internal haze of the two transparent substrate layers is 0.2% or more. Therefore, the scattering generated at the interface between the transparent resin layer and the spacer is hidden in the internal scattering of the transparent substrate layer. In addition, since the internal haze of each transparent substrate layer is less than 2.0% or the sum of the internal haze of the two transparent substrate layers is less than 4.0%, the transparency of the dimming sheet is not excessively impaired. As a result, whether in a transparent state or an opaque state, the spacer can be suppressed from having obvious uneven visibility.

[0019] In addition, the dispersion of spacers in the dimming layer will lead to the uneven presence of spacers. The internal scattering of the above-mentioned transparent substrate layer preferably suppresses the uneven visibility caused by the uneven presence of spacers. When the dimming sheet is pasted on the transparent body, the adhesive layer that joins the dimming sheet to the transparent body will reduce the external haze of the transparent substrate layer in the basic whole within the surface of the dimming sheet. Alternatively, the adhesive layer that joins the dimming sheet to the transparent body will cause the external haze of the transparent substrate layer to deviate within the surface of the dimming sheet. When a UV shielding film or anti-scattering film is pasted on the dimming sheet, the adhesive layer that joins the functional film to the transparent body will also reduce the external haze of the transparent substrate layer, or cause the external haze of the transparent substrate layer to deviate.

[0020] On the other hand, the internal haze of the transparent substrate layer is not reduced by various adhesive layers, and is not easily changed by various adhesive layers. Therefore, if the internal haze of the transparent substrate layer is 0.1% or more and 2.0% or less, the above-mentioned uneven visibility can be suppressed whether the dimming sheet is pasted on the transparent body, the functional film is pasted on the dimming sheet, or the dimming sheet is used alone. In addition, if the internal haze of the transparent substrate layer is 0.2% or more and 4.0% or less, the above-mentioned uneven visibility can be suppressed whether the dimming sheet is pasted on the transparent body, the functional film is pasted on the dimming sheet, or the dimming sheet is used alone.

[0021] In the dimming sheet, each transparent substrate layer may include a supporting layer for supporting the electrode layer, the external haze of each transparent substrate layer is the external haze of the electrode layer supported by the transparent substrate layer, and the internal haze of each supporting layer is greater than 0.1% and less than 2.0%.

[0022] The manufacturing method of the above-mentioned dimming sheet may be: the formation of the above-mentioned transparent substrate layer includes the step of stacking the above-mentioned electrode layer on the supporting layer so that the external haze of each transparent substrate layer is the external haze of the above-mentioned electrode layer supported by the above-mentioned transparent substrate layer, and the internal haze of the above-mentioned supporting layer is greater than 0.1% and less than 2.0%.

[0023] As described above, the external haze of the transparent substrate layer originates from the concavo-convex existing on the surface of the transparent substrate layer. According to the above-mentioned configurations, the external haze of the electrode layer supported by the support layer is the external haze of the transparent substrate layer. Therefore, the imbalance caused by the external haze of the electrode layer in the electric field acting between the two transparent substrate layers can be suppressed.

[0024] In the dimming sheet, each supporting layer may contain particles present in the supporting layer.

[0025] According to the above configuration, the internal haze of the transparent substrate layer can be realized by the particles present in the support layer. Thus, it is also easy to adjust the internal haze of the transparent substrate layer to a desired range.

[0026] In the dimming sheet, the average particle size of the particles may be 0.8 μm or more and 5.0 μm or less. According to this configuration, the effectiveness of suppressing significant uneven visibility of the spacer is improved.

[0027] In the dimming sheet, each supporting layer may include a base layer serving as a base for the electrode layer and a substrate supporting the base layer, and each base layer may contain particles present in the base layer.

[0028] The method for producing the dimming sheet may include a step of forming the support layer by laminating a base layer for laminating the electrode layer on a substrate, wherein the base layer contains particles present in the base layer.

[0029] According to the above-mentioned configurations, the internal haze of the transparent substrate layer can be realized by the particles present in the support layer. Thus, it is also easy to adjust the internal haze of the transparent substrate layer to a desired range.

[0030] In the dimming sheet, the difference in refractive index between the base resin layer surrounding the particles and the particles may be 0.01 to 0.05. With this configuration, it is easy to reduce the internal haze of the support layer to 0.1% to 2.0%.

[0031] In the dimming sheet, the transparent base material layer may include a contact surface in contact with the dimming layer, and an arithmetic mean roughness Sa of the contact surface may be 20 nm or less.

[0032] According to the above configuration, since the arithmetic mean roughness Sa of the contact surface with the light-adjusting layer is 20 nm or less, the non-uniformity of the electric field due to the thickness variation or shape variation of the light-adjusting layer can be suppressed.

[0033] The dimming sheet may have a haze of 6% or more and 10% or less in a transparent state. According to this configuration, the uneven visibility of the spacer can be suppressed by the internal haze of the transparent substrate layer, while ensuring the transparency of the dimming sheet.

[0034] Effects of the Invention

[0035] The dimming sheet and the method for manufacturing the dimming sheet disclosed in the present invention can obtain uniform visibility through the dimming sheet within the surface of the dimming sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a structural diagram showing the layer structure of the light control sheet together with the driving unit.

[0037] Figure 2 This is a table showing the visibility evaluation results of the light control sheets of Examples. DETAILED DESCRIPTION

[0038] An embodiment of a dimming sheet and a method for manufacturing the dimming sheet will be described. Figure 1 The structure of the dimming device is described below. Figure 2 Describe the internal haze of the support layer.

[0039] The dimming sheet is pasted on a transparent substrate. The transparent substrate can be a glass body or a resin body. The transparent substrate can be an interior decoration of a building or a mobile body, or an exterior decoration of a building or a mobile body. The transparent substrate can be a window glass mounted on a mobile body such as a vehicle or an airplane, or a window glass installed in a building, or a partition arranged in a car or indoors. The surface on which the dimming sheet is pasted can be a flat surface, or a curved surface such as a cylindrical surface or a spherical surface.

[0040] The dimming sheet can be attached to one side of a transparent substrate. The dimming sheet can also be attached to the surface of a transparent substrate and the back of the transparent substrate respectively. The dimming sheet can also be overlapped on other dimming sheets via an adhesive layer. The dimming sheet can also be attached to the surface of one transparent substrate and to the back of another transparent substrate at the same time, and be sandwiched by two transparent substrates.

[0041] The driving style of the dimming sheet can be either a forward type or a reverse type. The forward dimming sheet is in an opaque state when not driven. The forward dimming sheet changes from an opaque state to a transparent state by supplying a voltage signal as a driving signal. The forward dimming sheet returns from a transparent state to an opaque state by stopping the supply of the voltage signal. The reverse dimming sheet is in a transparent state when not driven. The reverse dimming sheet changes from a transparent state to an opaque state by supplying a voltage signal. The reverse dimming sheet returns from an opaque state to a transparent state by stopping the supply of the voltage signal.

[0042] The transparent state has a lower haze than the opaque state. The transparent state has a higher linear transmittance than the opaque state. The transparent state has a lower diffuse transmittance than the opaque state. The haze of the dimming sheet in the transparent state can be more than 6% and less than 10%. The haze of the dimming sheet in the opaque state can be more than 80%. The dimming sheet can have a transparent polymer layer that divides the gaps and a liquid crystal composition that fills the gaps. The dimming sheet can be transformed from a transparent state to an opaque state by increasing the refractive index difference between the transparent polymer layer and the liquid crystal composition. The dimming sheet can be transformed from an opaque state to a transparent state by reducing the refractive index difference between the transparent polymer layer and the liquid crystal composition.

[0043] The dimming sheet has two transparent substrate layers. The two transparent substrate layers sandwich the dimming layer in such a manner that each transparent substrate layer is in contact with the dimming layer. The total haze of one transparent substrate layer is obtained by a method based on JIS K-7136. The total haze of one transparent substrate layer is the sum of the external haze of one transparent substrate layer and the internal haze of one transparent substrate layer. The external haze of the transparent substrate layer originates from the concavities and convexities existing on the surface of the transparent substrate layer. When the concavities and convexities existing on the surface of the transparent substrate layer are flattened by a material having a refractive index equal to that of the surface, the external haze of the transparent substrate layer has a small effect on the total haze of the transparent substrate layer. When the external haze of the transparent substrate layer does not affect the total haze, the total haze of the transparent substrate layer is equivalent to the internal haze of the transparent substrate layer.

[0044] The forward type dimming sheet and the reverse type dimming sheet each have two transparent substrate layers, two transparent electrode layers (hereinafter also simply referred to as electrode layers), and a dimming layer. In the following embodiments, the structure and function of the reverse type dimming sheet are mainly described, and the structure of the forward type dimming sheet that is different from that of the reverse type is noted. Furthermore, the description of the structure of the forward type dimming sheet that is repeated in the reverse type is omitted. In the following examples, the structure and evaluation results of the forward type dimming sheet are mainly described.

[0045] [Configuration of the Light Control Sheet 11]

[0046] like Figure 1 As shown, the dimming device includes a dimming sheet 11 and a driving unit 51. The dimming sheet 11 includes a dimming layer 12, a first orientation layer 13F, a second orientation layer 13B, a first electrode layer 14F, a second electrode layer 14B, a first support layer 15F, and a second support layer 15B. The first orientation layer 13F, the first electrode layer 14F, and the first support layer 15F constitute a first transparent substrate layer. The second orientation layer 13B, the second electrode layer 14B, and the second support layer 15B constitute a second transparent substrate layer. The dimming layer 12 is located between the first transparent substrate layer and the second transparent substrate layer.

[0047] The dimming layer 12 is located between the first orientation layer 13F and the second orientation layer 13B. The first dimming surface 12SF of the dimming layer 12 contacts the first orientation layer 13F. The second dimming surface 12SB of the dimming layer 12 contacts the second orientation layer 13B. The first orientation layer 13F is located between the dimming layer 12 and the first electrode layer 14F, and contacts the dimming layer 12 and the first electrode layer 14F. The second orientation layer 13B is located between the dimming layer 12 and the second electrode layer 14B, and contacts the dimming layer 12 and the second electrode layer 14B.

[0048] The first electrode layer 14F is connected to the driving unit 51 through the first connection terminal P1 and the first wiring L1. The first electrode layer 14F is located between the first alignment layer 13F and the first support layer 15F, and contacts the first alignment layer 13F and the first support layer 15F. The second electrode layer 14B is connected to the driving unit 51 through the second connection terminal P2 and the second wiring L2. The second electrode layer 14B is located between the second alignment layer 13B and the second support layer 15B, and contacts the second alignment layer 13B and the second support layer 15B.

[0049] The dimming layer 12 includes a transparent resin layer and a liquid crystal composition. The transparent resin layer divides gaps in the transparent resin layer. The gaps in the transparent resin layer are filled with the liquid crystal composition. The liquid crystal composition using the transparent resin layer is maintained in a polymer dispersion type. In addition, the liquid crystal composition using the transparent resin layer can be maintained in a form selected from a polymer network type and a capsule type. The thickness of the dimming layer 12 can be greater than 1 μm and less than 100 μm.

[0050] The polymer dispersed dimming layer 12 has a transparent resin layer that divides a plurality of isolated voids as described above. The polymer dispersed dimming layer 12 holds a liquid crystal composition in the voids dispersed in the transparent resin layer. The polymer network dimming layer 12 has a three-dimensional mesh-like void in the transparent resin layer. The polymer network dimming layer 12 holds a liquid crystal composition in the mesh-like voids that are interconnected. The capsule-type dimming layer 12 holds a liquid crystal composition in the capsule-like voids dispersed in the transparent resin layer.

[0051] The first orientation layer 13F and the second orientation layer 13B respectively control the orientation direction of the liquid crystal compound. The first orientation layer 13F and the second orientation layer 13B are respectively seen as colorless and transparent or colored and transparent. When the liquid crystal compound is vertically oriented and achieves a transparent state, the first orientation layer 13F and the second orientation layer 13B are vertical orientation films. The vertical orientation film is to make the long axis direction of the liquid crystal compound along the thickness direction of the dimming layer 12, so that the visible light is transmitted to the dimming layer 12. When the liquid crystal compound is horizontally oriented and achieves a transparent state, the first orientation layer 13F and the second orientation layer 13B are horizontal orientation films, and the dimming sheet 11 can also have a polarizing layer in such a way that the long axis direction of the liquid crystal compound becomes parallel to the extension direction of the transmission axis of the polarizing layer. The reverse dimming sheet can have two orientation layers, or two orientation layers and a polarizing layer. In addition, the forward dimming sheet can have two orientation layers and a polarizing layer, or it can not have two orientation layers and a polarizing layer.

[0052] The materials constituting the first orientation layer 13F and the second orientation layer 13B are independently organic polymer compounds or inorganic oxides. The organic polymer compound can be any one selected from polyimide, polyamide, polyvinyl alcohol, and cyanide compounds. The inorganic oxide can be any one selected from silicon oxide, zirconium oxide, and organosilicon. The thickness of the orientation layers 13F and 13B can be respectively greater than 20 nm and less than 500 nm.

[0053] The first electrode layer 14F and the second electrode layer 14B are independently seen to be colorless and transparent or colored and transparent. The materials constituting the first electrode layer 14F and the second electrode layer 14B are conductive inorganic oxides, metals, or conductive organic polymer compounds, respectively. The conductive inorganic oxide can be any one selected from indium tin oxide, fluorine-doped tin oxide, tin oxide, and zinc oxide. The metal is a nanowire of gold or silver. The conductive organic polymer compound can be any one selected from carbon nanotubes and poly (3,4-ethylenedioxythiophene). The thickness of the electrode layers 14F and 14B can be respectively greater than 5 nm and less than 100 nm.

[0054] The first support layer 15F and the second support layer 15B are respectively and independently seen to be colorless and transparent or colored and transparent. The materials constituting the first support layer 15F and the second support layer 15B are respectively organic polymer compounds or inorganic polymer compounds. The organic polymer compound can be any one selected from polyester, polyacrylate, polycarbonate, and polyolefin. The inorganic polymer compound can be any one selected from silicon oxide, silicon nitride oxide, and silicon nitride.

[0055] The first transparent substrate layer has a first contact surface that contacts the first dimming surface 12SF of the dimming layer 12. The first contact surface is a side surface of the first orientation layer 13F. In addition, as in an example of a forward type, when the first transparent substrate layer does not have the first orientation layer 13F, the first contact surface of the first transparent substrate layer may be a side surface of the first electrode layer 14F.

[0056] The second transparent substrate layer has a second contact surface that contacts the second dimming surface 12SB of the dimming layer 12. The second contact surface is a side surface of the second orientation layer 13B. In addition, as in an example of a forward type, when the second transparent substrate layer does not have the second orientation layer 13B, the second contact surface of the second transparent substrate layer can be a side surface of the second electrode layer 14B.

[0057] When it is required to improve the in-plane uniformity of the electric field of the dimming layer 12, the arithmetic mean roughness Sa of the first contact surface is preferably 1 nm or more and 20 nm or less, more preferably 10 nm or more and 20 nm or less, and further preferably 10 nm or more and 15 nm or less. In addition, the arithmetic mean roughness Sa of the second contact surface is preferably 1 nm or more and 20 nm or less, more preferably 10 nm or more and 20 nm or less, and further preferably 10 nm or more and 15 nm or less. When the thickness of the first electrode layer 14F is as thin as 5 nm or more and 100 nm or less, the arithmetic mean roughness Sa of the first support surface 151F in the first support layer 15F that contacts the first electrode layer 14F is preferably 1 nm or more and 20 nm or less, more preferably 10 nm or more and 20 nm or less, and further preferably 10 nm or more and 15 nm or less. When the thickness of the second electrode layer 14B is as thin as 5 nm to 100 nm, the arithmetic mean roughness Sa of the second support surface 151B in the second support layer 15B that contacts the second electrode layer 14B is preferably 1 nm to 20 nm, more preferably 10 nm to 20 nm, and further preferably 10 nm to 15 nm.

[0058] The driving unit 51 is connected to the first electrode layer 14F and the second electrode layer 14B, respectively. The driving unit 51 supplies a voltage signal to the first electrode layer 14F and the second electrode layer 14B. The voltage signal applies a voltage for changing the alignment state of the liquid crystal compound between the first electrode layer 14F and the second electrode layer 14B.

[0059] The driving unit 51 supplies a voltage signal to make the orientation state of the liquid crystal compound follow the electric field, thereby changing the light-adjusting sheet 11 from a transparent state to an opaque state. The driving unit 51 stops supplying the voltage signal to make the orientation state of the liquid crystal compound follow the orientation control force of the orientation layers 13F and 13B, thereby changing the light-adjusting sheet 11 from an opaque state to a transparent state.

[0060] In addition, the forward-type driving unit 51 causes the orientation state of the liquid crystal compound to follow the electric field by supplying a voltage signal, thereby changing the dimming sheet 11 from an opaque state to a transparent state. The forward-type driving unit 51 causes the orientation state of the liquid crystal compound to become a disordered state by stopping the supply of the voltage signal, thereby changing the dimming sheet 11 from a transparent state to an opaque state. When the forward-type driving unit 51 changes from an opaque state to a transparent state, the voltage applied between the first electrode layer 14F and the second electrode layer 14B can be made lower than that of the reverse-type by only the portion that does not need to resist the orientation control force. In addition, when the forward-type dimming sheet 11 changes from an opaque state to a transparent state, the thickness of the dimming layer 12 can be made thicker than that of the reverse-type by only the portion that does not need to resist the orientation control force.

[0061] [Configuration of the Light Adjusting Layer 12]

[0062] The dimming layer 12 includes a transparent resin layer, a liquid crystal composition, and a spacer. The transparent resin layer divides a plurality of gaps inside the transparent resin layer. The gaps divided in the transparent resin layer are filled with the liquid crystal composition. Each gap can be an isolated gap separated from other gaps. A part of each gap can also be connected to other gaps. The size of the gap is more than two kinds. The shape of the gap is spherical, ellipsoidal, or indefinite.

[0063] The size of the voids in the cross section of the dimming layer 12 is the diameter of a circle circumscribed to the voids in the cross section. The size of the voids in the dimming layer 12 is the average of the sizes of all voids contained in the cross section of the dimming layer 12. When the haze of the dimming sheet 11 in a transparent state is required to be reduced, the size of the voids can be further enlarged. And when the haze of the dimming sheet 11 in an opaque state is required to be increased, the size of the voids can be further reduced. The size of the voids in the dimming layer 12 can be sufficiently smaller than the size of the spacer, and can be the average particle size of the spacer or less than half of the average particle size of the spacer, or less than 1 / 4.

[0064] The transparent resin layer is a cured product of a photopolymerizable compound. The photopolymerizable compound may be an ultraviolet curable compound or an electron beam curable compound. The photopolymerizable compound is compatible with the liquid crystal composition. When it is required to improve the size controllability of the voids, the photopolymerizable compound is preferably an ultraviolet curable compound. The ultraviolet curable compound may contain a polymerizable unsaturated bond at the end of the molecular structure. Alternatively, the ultraviolet curable compound may also contain a polymerizable unsaturated bond other than the end of the molecular structure. The photopolymerizable compound is one polymerizable compound or a combination of two or more polymerizable compounds.

[0065] The ultraviolet curable compound may be at least one selected from acrylate compounds, methacrylate compounds, styrene compounds, thiol-ene compounds, and oligomers of the compounds.

[0066] The acrylate compound includes a monoacrylate compound, a diacrylate compound, a triacrylate compound, and a tetraacrylate compound. The acrylate compound may be butyl ethyl acrylate, ethylhexyl acrylate, or cyclohexyl acrylate. The methacrylate compound may be a dimethacrylate compound, a trimethacrylate compound, or a tetramethacrylate compound. The methacrylate compound may be N,N-dimethylaminoethyl methacrylate, phenoxyethyl methacrylate, methoxyethyl methacrylate, or tetrahydrofurfuryl methacrylate. The thiol compound may be 1,3-propanedithiol or 1,6-hexanedithiol. The styrene compound may be styrene or methylstyrene.

[0067] The lower limit of the content of the transparent resin layer relative to the total amount of the transparent resin layer and the liquid crystal composition may be 20% by mass, and a more preferred lower limit of the content may be 30% by mass. The upper limit of the content of the transparent resin layer relative to the total amount of the transparent resin layer and the liquid crystal composition may be 70% by mass, and a more preferred upper limit of the content may be 60% by mass.

[0068] The lower limit and upper limit of the content of the transparent resin layer are the ranges in which the liquid crystal particles formed by the liquid crystal composition are phase-separated from the cured product of the photopolymerizable compound during the curing process of the photopolymerizable compound. When the mechanical strength of the transparent resin layer is required to be improved, the lower limit of the content of the transparent resin layer is preferably high. When it is required to suppress the voltage for driving the liquid crystal compound, the upper limit of the content of the transparent resin layer is preferably low.

[0069] The liquid crystal composition contains a liquid crystal compound. It has a positive dielectric anisotropy in which the dielectric constant in the long axis direction of the liquid crystal compound is larger than the dielectric constant in the short axis direction of the liquid crystal compound. Alternatively, it has a negative dielectric anisotropy in which the dielectric constant in the long axis direction of the liquid crystal compound is lower than the dielectric constant in the short axis direction of the liquid crystal compound. The liquid crystal compound can be at least one selected from Schiff base series, azo series, azoxy series, biphenyl series, terphenyl series, benzoate series, diphenyl acetylene series, pyrimidine series, pyridazine series, cyclohexanecarboxylate series, phenylcyclohexane series, biphenylcyclohexane series, dicyanobenzene series, naphthalene series, and dioxane series.

[0070] Liquid crystal compound is a combination of one liquid crystal compound or two or more liquid crystal compounds. The liquid crystal composition may also contain dichroic pigments, defoamers, antioxidants, weathering agents, and solvents. The dichroic pigment is driven by a guest-host pattern with the liquid crystal compound as the main body and presents color. The dichroic pigment may be at least one selected from high polyiodine, azo compounds, anthraquinone compounds, naphthoquinone compounds, azomethine compounds, tetrazine compounds, quinophthalone compounds, cyanine compounds, perylene compounds, and dioxazine compounds. The dichroic pigment is a combination of one compound or two or more compounds. When it is required to improve light resistance and improve the two-color ratio, the dichroic pigment may be at least one selected from azo compounds and anthraquinone compounds, more preferably azo compounds. The weathering agent may be a light stabilizer.

[0071] The refractive index difference Δn (Δn=extraordinary refractive index ne-ordinary refractive index no) between the long axis direction and the short axis direction of the liquid crystal compound indicates the degree of intermolecular interaction in the liquid crystal compound. The refractive index difference Δn of the liquid crystal compound is the difference in refractive index under visible light with a wavelength of 650nm, which indicates the difference in the degree of scattering of visible light between when the voltage signal is supplied and when it is not supplied. When the liquid crystal compound is a combination of two or more liquid crystal compounds, the upper limit value of the refractive index difference Δn of the liquid crystal compound is the upper limit value obtained from the refractive index difference Δn of all liquid crystal compounds. The lower limit value of the refractive index difference Δn of the liquid crystal compound is the lower limit value obtained from the refractive index difference Δn of all liquid crystal compounds. When the haze difference between the transparent state and the opaque state is required to be enlarged, the lower limit value of the refractive index difference Δn is preferably high. When the haze difference between the transparent state and the opaque state is required to be enlarged, the lower limit value of the refractive index difference Δn of the liquid crystal compound is preferably 0.005, more preferably 0.01.

[0072] [Spacer]

[0073] The spacers are distributed throughout the transparent resin layer. The spacers determine the thickness of the light-adjusting layer 12 around the spacers. The spacers make the thickness of the light-adjusting layer 12 uniform. The spacers may be bead spacers. The spacers may also be photospacers obtained by exposure and development of a photoresist.

[0074] The spacer may be colorless and transparent or colored and transparent. When the liquid crystal composition contains a dichroic pigment, the color presented by the spacer is preferably the same color as the color presented by the dichroic pigment. When the color presented by the spacer is the same color as the color presented by the dichroic pigment, the depth of the color presented by the opaque dimming sheet 11 may also be increased.

[0075] The spacer may have a spherical shape or a columnar shape. The size of the spacer in the thickness direction of the dimming layer 12 may be appropriately changed according to the required thickness of the dimming layer 12. The size of the spacer in the thickness direction of the dimming layer 12 may be greater than 5 μm and less than 50 μm. When the spacer has a spherical shape, the average particle size of the spacer is, for example, greater than 5 μm and less than 50 μm. The average particle size of the spacer is obtained using a particle size distribution measuring device that uses principles such as laser scattering, resistance value change, and image analysis after shooting. The average particle size of the spacer is the number average particle size. When the spacer has a columnar shape, the average diameter of the spacer may be greater than 5 μm and less than 50 μm. When power saving of the dimming sheet 11 is required, in order to reduce the thickness of the dimming layer 12, it is preferred that the average particle size of the spacer or the average diameter of the spacer is greater than 5 μm and less than 30 μm.

[0076] The area occupancy rate of the spacer can be greater than 0.9% and less than 30.0%. The area occupancy rate of the spacer refers to the ratio of the area occupied by the spacer in the unit area relative to the unit area of ​​the dimming sheet 11. The area occupied by the spacer is obtained by observing from a viewpoint facing the first surface 11F of the dimming sheet 11 in a transparent state. An example of a unit area in the dimming sheet 11 is 1mm×1mm. The area occupied by the spacer is calculated by observing the unit area of ​​the dimming sheet 11 in a transparent state using an optical microscope. The slight refractive index difference between the spacer and the transparent resin layer makes the area corresponding to the spacer slightly whiter than the surrounding area in the image taken by the optical microscope. The area occupied by the spacer is obtained by binarizing the image obtained by using an optical microscope, and the sum of the areas of the granular areas that are slightly whiter than the surrounding area. When the spacer has a spherical shape, the granular area has a spherical shape. When the spacer has a columnar shape, the granular area has a rectangular shape.

[0077] The constituent material of the spacer may be a transparent inorganic compound with insulating properties, or may be a transparent resin with insulating properties. The transparent inorganic compound may be any one selected from silicon dioxide and aluminum oxide. The transparent resin may be at least one selected from acrylic resin, epoxy resin, phenolic resin, melamine resin, polyester, polycarbonate, polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, and acetyl cellulose. When the spacer is colored and transparent, the constituent material of the spacer may be a transparent resin in which a colored pigment is dispersed. When the spacer is dispersed in the coating liquid used to form the dimming layer 12, that is, in a liquid containing a curable compound and a liquid crystal composition, the surface of the spacer may also be subjected to a surface treatment for imparting lyophilicity to the coating liquid. When the transmittance in the transparent dimming sheet 11 is required to be increased, the total light transmittance of the constituent material of the spacer is preferably 80% or more.

[0078] The constituent material of the spacer may have a refractive index of 1.4 or more and 1.6 or less. The constituent material of the spacer has a refractive index different from the refractive index of the transparent resin constituting the light-adjusting layer 12 .

[0079] [Configuration of Support Layers 15F and 15B]

[0080] The support layers 15F and 15B may be single-layer structures. The constituent materials of the support layers 15F and 15B may be transparent resins or transparent inorganic compounds. The support layers 15F and 15B may contain particles in the layer. The constituent materials of the particles may be transparent resins or transparent inorganic compounds.

[0081] The support layers 15F and 15B may be multilayer structures. When the support layers 15F and 15B are multilayer structures, the support layers 15F and 15B respectively include a substrate and a base layer supported by the substrate. The support layer is located between the substrate and the electrode layers 14F and 14B, and is in contact with the substrate and the electrode layers 14F and 14B.

[0082] The constituent material of the substrate may be a transparent resin or a transparent inorganic compound. The substrate may contain particles in the substrate.

[0083] The constituent material of the base layer may be a transparent resin or a transparent inorganic compound. The base layer may contain particles in the base layer. The constituent material of the particles may be a transparent resin or a transparent inorganic compound. When the particles are colored and transparent, the constituent material of the particles may be a transparent resin in which a colored pigment is dispersed. The refractive index of the transparent resin constituting the base layer may be greater than 1.4 and less than 1.6, and the refractive index of the particles constituting the base layer may be greater than 1.4 and less than 1.6. The constituent material of the particles has a refractive index different from the refractive index of the transparent resin constituting the base layer. When the transmittance of the dimming sheet 11 in a transparent state is required to be increased, the total light transmittance of the constituent material of the particles is preferably greater than 80%.

[0084] The transparent resin may be at least one selected from polyester, polyacrylate, polycarbonate, polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, and acetyl cellulose. Polyester may be at least one selected from polyethylene terephthalate and polyethylene naphthalate. Polyacrylate may be at least one selected from polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, and polyethylhexyl acrylate. Polyolefin may be at least one selected from polyethylene, polypropylene, polymethylpentene, ethylene-vinyl acetate copolymer, cycloolefin polymer, and cycloolefin copolymer.

[0085] The transparent inorganic compound may be at least one selected from silicon dioxide, silicon oxynitride, and silicon nitride.

[0086] The thickness of the support layers 15F and 15B is appropriately selected in order to obtain the flexibility or transparency required by the dimming sheet 11. The thickness of the support layers 15F and 15B is appropriately selected in order to obtain the internal haze required by the transparent substrate layer. The first transparent substrate layer having the first support layer 15F, the first electrode layer 14F, and the first orientation layer 13F satisfies the following conditions 1 and 2. The second transparent substrate layer having the second support layer 15B, the second electrode layer 14B, and the second orientation layer 13B also satisfies the following conditions 1 and 2. Or the first transparent substrate layer and the second transparent substrate layer satisfy conditions 1 and 3.

[0087] (Condition 1) The external haze of each transparent base material layer is less than 0.1%.

[0088] (Condition 2) The internal haze of each transparent base material layer is 0.1% or more and 2.0% or less.

[0089] (Condition 3) The sum of the internal haze of the two transparent base material layers is 0.2% or more and 4.0% or less.

[0090] The external haze of the first transparent substrate layer originates from the unevenness of the first surface 11F, which is one side surface of the first support layer 15F. In addition, the external haze of the first transparent substrate layer originates from the unevenness of one side surface of the first orientation layer 13F in contact with the first dimming surface 12SF of the dimming layer 12. In addition, when the transparent substrate layer does not include the first orientation layer 13F as in an example of a forward type, the external haze of the transparent substrate layer including the first support layer 15F originates from the unevenness of one side surface of the first electrode layer 14F in contact with the first dimming surface 12SF of the dimming layer 12.

[0091] The external haze of the first transparent substrate layer may be 0% or more and less than 0.1%. When it is required to see the distribution of the spacers and suppress the imbalance of the electric field acting between the two transparent substrate layers, the external haze of the first transparent substrate layer is less than 1.6%, preferably 0% or more and 1.0% or less, and more preferably meets condition 1.

[0092] The external haze of the second transparent substrate layer originates from the unevenness of the second layer 11B as one side surface of the second support layer 15B. In addition, the external haze of the second transparent substrate layer originates from the unevenness of one side surface of the second orientation layer 13B in contact with the second dimming surface 12SB of the dimming layer 12. In addition, when the transparent substrate layer does not have the second orientation layer 13B as in an example of a forward type, the external haze of the transparent substrate layer including the second support layer 15B originates from the unevenness of one side surface of the second electrode layer 14B in contact with the second dimming surface 12SB of the dimming layer 12.

[0093] The external haze of the second transparent substrate layer may be 0% or more and less than 0.1%. When it is required to see the distribution of the spacers and suppress the imbalance of the electric field acting between the two transparent substrate layers, the external haze of the second transparent substrate layer is less than 1.6%, preferably 0% or more and 1.0% or less, and more preferably meets condition 1.

[0094] The internal haze of the first transparent substrate layer is the sum of the internal hazes of the layers constituting the first transparent substrate layer. The internal haze of the second transparent substrate layer is the sum of the internal hazes of the layers constituting the second transparent substrate layer. An example of the layers constituting the first transparent substrate layer is the orientation layer 13F, the electrode layer 14F, and the support layer 15F. An example of the layers constituting the second transparent substrate layer is the orientation layer 13B, the electrode layer 14B, and the support layer 15B.

[0095] When the haze stability of the dimming sheet 11 in a transparent state is required, the internal haze of each transparent substrate layer may be greater than 0.1% and less than 0.4%. When the haze stability of the dimming sheet 11 in a transparent state is required, the sum of the internal haze of the two transparent substrate layers may be greater than 0.2% and less than 0.8%. When it is required to suppress the visibility of the spacer in a transparent state, the internal haze of each transparent substrate layer may be greater than 0.4% and less than 2.0%. When it is required to suppress the visibility of the spacer in a transparent state, the sum of the internal haze of the two transparent substrate layers may be greater than 0.8% and less than 4.0%.

[0096] Internal haze originates from differences in refractive index between internal elements of a layer and structural differences between internal elements. Internal haze can be increased by increasing the amount of particles added to a layer. Internal haze can be reduced by decreasing the amount of particles added to a layer. Internal haze can be increased by increasing the crystal density. Internal haze can be reduced by reducing the crystal density.

[0097] The electrode layers 14F and 14B supply voltage signals to the dimming layer 12, respectively. The suppression of the resistance value in the electrode layers 14F and 14B can suppress the formation of a voltage gradient in the plane of the electrode layers 14F and 14B, thereby seeking to achieve in-plane uniformity of visibility. The suppression of the resistance value in the electrode layers 14F and 14B makes it possible to save power in the dimming device. On the other hand, adding particles to the electrode layers 14F and 14B in a manner that satisfies conditions 2 and 3, or increasing the crystal density of the electrode layers 14F and 14B will increase the resistance value of the electrode layers 14F and 14B. From the viewpoint of seeking in-plane uniformity of visibility and from the viewpoint of seeking to save power in the dimming device, it is preferred that the internal haze of the electrode layers 14F and 14B is zero.

[0098] The orientation layers 13F and 13B respectively exert an orientation control force on the liquid crystal compound. The increase in the orientation control force of the orientation layers 13F and 13B increases the linear transmittance in the transparent state and increases the speed of transition from the opaque state to the transparent state. On the other hand, adding particles to the orientation layers 13F and 13B in a manner that satisfies conditions 2 and 3, or increasing the crystal density of the orientation layers 13F and 13B, will reduce the orientation control force of the orientation layers 13F and 13B. From the viewpoint of increasing the linear transmittance in the transparent state and from the viewpoint of increasing the responsiveness of the state transition, it is preferred that the internal haze of the orientation layers 13F and 13B is substantially zero.

[0099] Therefore, in order to make each transparent substrate layer satisfy condition 2, it is preferred that the internal haze of the support layers 15F and 15B is 0.1% or more and 2.0% or less. When the support layers 15F and 15B respectively include a substrate and a base layer, the internal haze of each substrate may be substantially zero, and the internal haze of each base layer may be 0.1% or more and 2.0% or less.

[0100] Alternatively, in order to make the two transparent substrate layers satisfy condition 3, the sum of the internal haze of the support layers 15F and 15B is preferably 0.2% or more and 4.0% or less. When the support layers 15F and 15B respectively include a substrate and a base layer, the internal haze of each substrate may be substantially zero, and the internal haze of each base layer may be 0.2% or more and 4.0% or less.

[0101] The thickness of the base layer may be 1 μm to 10 μm, or 2 μm to 8 μm. When the particles for imparting internal haze to the base layer are present in the base layer, the base layer may include the particles and a base resin layer surrounding the particles.

[0102] The average particle size of the particles constituting the base layer may be 0.4 μm or more and 10 μm or less, or 0.8 μm or more and 5.0 μm or less. The average particle size of the particles is the arithmetic mean diameter, which is obtained by a method based on JIS Z 8828:2019. If the average particle size of the particles present in the base layer is 10 μm or less, it is easy to obtain forward scattering using Mie scattering, so that the decrease in total light transmittance caused by backward scattering can be suppressed in an opaque state. If the average particle size of the particles present in the base layer is 0.4 μm or more, it is easy to obtain an internal haze of the base layer that satisfies conditions 2 and 3.

[0103] The difference in refractive index between the base resin layer and the particles constituting the base layer may be 0.01 or more and 0.05 or less. If the difference in refractive index between the base resin layer and the particles is 0.01 or more, the thickness of the base layer for satisfying conditions 2 and 3 can be suppressed from increasing to a degree that greatly reduces the total light transmittance. If the difference in refractive index between the base resin layer and the particles is 0.05 or less, the thickness of the base layer for satisfying conditions 2 and 3 can be suppressed from decreasing to a degree that causes deviation.

[0104] In addition, the dimming sheet 11 may also have other functional layers in addition to the above layers. Other functional layers may be gas barrier layers that inhibit oxygen or moisture from penetrating into the dimming layer 12, or ultraviolet blocking layers that inhibit ultraviolet light other than a specific wavelength from penetrating into the dimming layer 12. Other functional layers may also be hard coating layers that mechanically protect the layers of the dimming sheet 11, or adhesive layers that improve the interlayer adhesion in the dimming sheet 11.

[0105] [Method for Manufacturing the Light-Controlling Sheet 11]

[0106] The method for manufacturing the dimming sheet 11 uses a coating liquid containing a photopolymerizable compound and a liquid crystal composition. The method for manufacturing the dimming sheet 11 includes a step of forming a coating film between a first transparent substrate layer and a second transparent substrate layer using the coating liquid. The first transparent substrate layer includes a first orientation layer 13F, a first electrode layer 14F, and a first support layer 15F. The second transparent substrate layer includes a second orientation layer 13B, a second electrode layer 14B, and a second support layer 15B. The coating film is formed in a manner of contacting the first orientation layer 13F and the second orientation layer 13B.

[0107] In addition, the method for manufacturing the light-adjusting sheet 11 without the first alignment layer 13F and the second alignment layer 13B is to form a finishing film between the first electrode layer 14F and the second electrode layer 14B. The finishing film is formed so as to be in contact with the first electrode layer 14F and the second electrode layer 14B.

[0108] The coating film contains a polymerization initiator for initiating polymerization of the photopolymerizable compound. The polymerization initiator may be at least one selected from a diketone compound, an acetophenone compound, a benzoin compound, a benzophenone compound, and a thioxanthone compound. The polymerization initiator may be one compound or a combination of two or more compounds. The polymerization initiator may be any one selected from benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and cyclohexyl phenyl ketone.

[0109] The manufacturing method of the dimming sheet 11 includes the following steps: by polymerizing a photopolymerizable compound in a coating film, liquid crystal particles formed by a liquid crystal composition are phase-separated from a polymer, thereby forming a transparent resin layer dividing a gap and a liquid crystal composition filling the gap. The light for polymerizing the photopolymerizable compound may be ultraviolet light or electron beam. The light irradiated to the coating film may be irradiated to the first support layer 15F, or to the second support layer 15B, or a combination of the two.

[0110] The phase separation of the liquid crystal particles formed by the liquid crystal composition is promoted by the polymerization of the photopolymerizable compound and the diffusion of the liquid crystal composition. The speed at which the photopolymerizable compound polymerizes varies with the intensity of the light irradiated to the photopolymerizable compound. The speed at which the liquid crystal composition diffuses varies with the treatment temperature during the polymerization of the photopolymerizable compound. In the phase separation of the liquid crystal composition, the intensity of the light irradiated to the photopolymerizable compound is set so that the size of the liquid crystal particles becomes the desired size, that is, so that the size of the gap becomes the desired size.

[0111] When the photopolymerizable compound polymerizes at a high speed, phase separation is promoted simultaneously in most parts of the coating film, and the size of the voids tends to become smaller. When the photopolymerizable compound polymerizes at a low speed, phase separation is promoted in a few parts of the coating film, and the size of the voids tends to become larger. During the phase separation of the liquid crystal composition, heating may be performed to promote diffusion of the liquid crystal composition.

[0112] In addition, when the supporting layers 15F and 15B respectively have a substrate and a base layer, the manufacturing method of the dimming sheet 11 forms a coating film for forming a base layer on the substrate before forming a coating film for forming the dimming layer 12. The coating film for forming the base layer contains a photopolymerizable compound, a polymerization initiator, and particles. The photopolymerizable compound is preferably a hard coating agent. The hard coating agent can be at least one selected from acrylate compounds, methacrylate compounds, styrene compounds, thiol-ene compounds, and oligomers of each compound. The particles can be at least one selected from acrylic particles, methacrylic particles, polystyrene particles, thiol-ene particles, silica particles, and aluminum oxide particles.

[0113] The base layer coating liquid for forming the base layer has particles dispersed in a liquid containing a photocurable compound and a polymerization initiator. The surface of the particles in the base layer coating liquid may be subjected to a surface treatment for imparting lyophilicity to the coating liquid.

[0114] [Example]

[0115] [Transparent substrate layer of Example 1]

[0116] The base layer coating liquid for forming the base layer is applied on the substrate to obtain support layers 15F and 15B. Next, the electrode layers 14F and 14B are formed on the support layers 15F and 15B to obtain two transparent base layers of Example 1.

[0117] Here, as a substrate, a display glass plate AN100 (product name: manufactured by AGC Corporation) with a thickness of 0.7 mm is used. The shape of the substrate is a rectangle of 100 mm×100 mm. In addition, as a base layer coating liquid, a mixture of 100 parts by weight of acrylic hard coating agent mixed and stirred with 1 part by weight of acrylic particles is used. As an acrylic hard coating agent, DeSolite (registered trademark) Z7501 (product name: manufactured by JSR Corporation) having a refractive index of 1.49 in the cured product is used. As acrylic particles, MX500 (product name: manufactured by Soken Chemical Co., Ltd.) having a refractive index of 1.50 and an average particle size of 5 μm is used. The coating film of the base layer coating liquid is dried and irradiated with ultraviolet rays, thereby obtaining a hard coating layer with a thickness of 5 μm as the base layer of Example 1.

[0118] As the electrode layers 14F and 14B, an indium oxide / tin layer with a thickness of 50 nm was used. At this time, a sintered body of indium oxide and tin oxide was used as a target, and argon gas was used as a sputtering gas, and an indium oxide / tin layer was formed on the base layer by sputtering. Furthermore, the indium oxide / tin layer was heat-treated in an ambient gas at 140°C, thereby obtaining a crystallized indium oxide / tin layer as the electrode layers 14F and 14B of Example 1. In addition, as the contact surface of Example 1, a surface on the opposite side of the back side of the contact base layer in the electrode layers 14F and 14B was obtained.

[0119] [Dimming Sheet 11 of Example 1]

[0120] First, the spacer dispersion was applied to the contact surface of one transparent substrate layer of Example 1, thereby dispersing the bead spacers on the contact surface.

[0121] Here, divinylbenzene was used as a constituent material of the bead spacer. In addition, a bead spacer having an average particle size of 25 μm was dispersed in an alcohol solvent to obtain a spacer dispersion of Example 1. Furthermore, the spacer dispersion was applied to the four corners and the center of the transparent substrate layer of Example 1 using a dropper so that the area occupancy of the spacer reached 20.0%, and the spacer dispersion was dried in an environment of 100°C.

[0122] Next, the light-adjusting layer coating liquid was applied to the contact surface where the spacers were spread, and then the coating film of the light-adjusting layer coating liquid was sandwiched between the two contact surfaces and cured by ultraviolet irradiation, thereby obtaining the light-adjusting sheet of Example 1.

[0123] Here, as the light-adjusting layer coating liquid, a polymer network type liquid crystal coating liquid KN-F-001-01 (product name: Kyushu Nanotec Optical Co., Ltd.) was used. As ultraviolet irradiation, a high-pressure mercury lamp with a wavelength cutoff below 350 nm was used, and the illumination was set to 20 mW / cm 2 , and the irradiation time was set to 30 seconds. Thus, a light-adjusting layer 12 having a thickness of 25 μm and including a transparent resin layer defining gaps, a liquid crystal composition filling the gaps, and spacers was formed.

[0124] [Example 2]

[0125] The acrylic hard coating agent of Example 1 was changed to a vinyl mixed hard coating agent having a refractive index of 1.47 in the cured product. The acrylic particles of Example 1 were changed to MX80H (product name: manufactured by Soken Chemical Co., Ltd.) having a refractive index of 1.49 and an average particle size of 0.8 μm. Furthermore, 100 parts by weight of the vinyl mixed hard coating agent was mixed with 1 part by weight of the acrylic particles to obtain a base layer coating liquid. The transparent substrate layer and the dimming sheet 11 of Example 2 were obtained in the same manner as in Example 1 except that the above-mentioned method was used.

[0126] Here, the vinyl-based mixed hard coating agent used a mixture of polymethyl methacrylate (manufactured by Kuraray Co., Ltd.) and vinyl chloride-vinyl acetate copolymer (Solbin C (registered trademark): manufactured by Nissin Chemical Co., Ltd.). In addition, the vinyl-based mixed hard coating agent used methyl ethyl ketone and toluene as solvents. Furthermore, polymethyl methacrylate: vinyl chloride-vinyl acetate copolymer: methyl ethyl ketone: toluene were mixed and stirred in a ratio of 6:4:5:5 to obtain the vinyl-based mixed hard coating agent of Example 2.

[0127] [Example 3]

[0128] The acrylic hard coating agent of Example 1 was changed to DeSolite (registered trademark) Z7528 (product name: manufactured by JSR Corporation) having a refractive index of 1.50 in the cured product. The acrylic particles of Example 1 were changed to acrylic particles TECHPOLYMER (registered trademark) MX16LA (manufactured by Sekisui Chemicals Co., Ltd.) having a refractive index of 1.55 and an average particle size of 2.5 μm. Furthermore, 1 part by weight of the acrylic particles was mixed and stirred with 100 parts by weight of the acrylic hard coating agent to obtain a base layer coating liquid. The transparent substrate layer and the dimming sheet 11 of Example 3 were obtained in the same manner as in Example 1 except that the above-mentioned method was used.

[0129] [Comparative Example 1]

[0130] The base layer was omitted from the transparent base layer of Example 1, and the electrode layer was directly formed on one side of a base material AN100 (product name: manufactured by AGC Corporation), thereby obtaining a transparent base layer of Example 2 and a light-adjusting sheet 11 .

[0131] [Comparative Example 2]

[0132] The acrylic hard coating agent of Example 1 was changed to a mixture of Opstar (registered trademark) TU4005 (product name: manufactured by JSR Corporation) and KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.). DPHA is a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate. In the acrylic hard coating agent of Comparative Example 2, 5 parts by weight of DPHA were mixed and stirred with 100 parts by weight of TU4005. The refractive index of the cured product using the acrylic hard coating agent of Comparative Example 2 was 1.60.

[0133] The acrylic particles of Example 1 were changed to MX80H (product name: Soken Chemical Co., Ltd.) having a refractive index of 1.49 and an average particle size of 0.9 μm. Furthermore, 5 parts by weight of acrylic particles were mixed and stirred with 100 parts by weight of acrylic hard coating agent to obtain a base layer coating liquid. A transparent substrate layer and a dimming sheet 11 of Comparative Example 2 were obtained in the same manner as in Example 1 except that the above-mentioned method was repeated.

[0134] [Comparative Example 3]

[0135] The acrylic hard coating agent of Example 1 was changed to a vinyl mixed hard coating agent whose cured product had a refractive index of 1.47. The acrylic particles of Example 1 were changed to MX500 (product name: Soken Chemical Co., Ltd.) having a refractive index of 1.50 and an average particle size of 5 μm. Furthermore, 100 parts by weight of the vinyl hard coating agent was mixed with 1 part by weight of the acrylic particles to obtain a base layer coating liquid, and the thickness of the hard coating layer was changed to 4 μm. The transparent substrate layer and the dimming sheet 11 of Comparative Example 3 were obtained in the same manner as in Example 1 except that the thickness of the hard coating layer was changed to 4 μm.

[0136] Here, the vinyl-based mixed hard coating agent used a mixture of polymethyl methacrylate (manufactured by Kuraray Co., Ltd.) and vinyl chloride-vinyl acetate copolymer (Solbin C (registered trademark): manufactured by Nissin Chemical Co., Ltd.). In addition, the vinyl-based mixed hard coating agent used methyl ethyl ketone and toluene as solvents. Furthermore, polymethyl methacrylate: vinyl chloride-vinyl acetate copolymer: methyl ethyl ketone: toluene were mixed and stirred in a ratio of 6:4:5:5 to obtain a vinyl-based mixed hard coating agent of Comparative Example 3.

[0137] [Evaluation of transparent substrate layer]

[0138] The total haze of the transparent base material layer was measured using a haze meter of NDH 7000SP (product name: manufactured by Nippon Denshoku Industries Co., Ltd.) and a method based on JIS K7136.

[0139] A scanning white interference microscope, VertScan R3300h Lite (manufactured by Ryoka System Co., Ltd.), was used to measure the arithmetic mean roughness Sa of the contact surface of the transparent base material layer in a rectangular shape of 1.408 mm×1.885 mm.

[0140] The display glass plate AN100 was attached to the surface of the electrode layers 14F and 14B via an acrylic non-carrier tape. Thus, the haze originating from the surface irregularities of the electrode layers 14F and 14B, i.e., the external haze, was suppressed. Furthermore, NDH 7000SP (product name: manufactured by Nippon Denshoku Industries) was used as a haze meter, and the haze of the transparent substrate layer after attaching the display glass plate was measured as the internal haze of the transparent substrate layer by a method based on JIS K7136.

[0141] [Evaluation of light-adjusting sheet 11]

[0142] The haze of the opaque light-adjusting sheet 11 was measured using a haze meter NDH 7000SP (product name: Nippon Denshoku Industries Co., Ltd.) and a method based on JIS K7136. Furthermore, a voltage signal with a frequency of 60 Hz and a voltage of 40 V was supplied between the electrode layers 14F and 14B to measure the haze of the light-adjusting sheet 11 in a transparent state.

[0143] White light was irradiated to the dimming sheet 11 from a three-wavelength fluorescent lamp 0.5 m away from the dimming sheet 11 in the normal direction of the dimming sheet 11. An observation point 0.5 m away from the dimming sheet 11 in the normal direction of the dimming sheet 11 was set on the opposite side of the three-wavelength fluorescent lamp to the dimming sheet 11. The appearance of the dimming sheet 11 was then observed to determine whether uneven distribution of the spacers was visible.

[0144] [Evaluation results]

[0145] like Figure 2 As shown, the total haze of Example 1 is 0.1%. It can be seen that the internal haze of Example 1 is 0.1%, and the external haze of Example 1 originating from the surface of the transparent substrate layer is substantially 0%, less than 0.1%. The arithmetic mean roughness Sa of the contact surface of Example 1 is 15 nm. The haze of the dimming sheet 11 in the opaque state of Example 1 is 98%, and the haze of the dimming sheet 11 in the transparent state is 6%.

[0146] The total haze of Example 2 is 0.4%. It can be seen that the internal haze of Example 2 is 0.4%, and the external haze of Example 2 originating from the surface of the transparent substrate layer is substantially 0%, less than 0.1%. The arithmetic mean roughness Sa of the contact surface of Example 2 is 11 nm. The haze of the dimming sheet 11 in the opaque state of Example 2 is 98%, and the haze of the dimming sheet 11 in the transparent state is 6%.

[0147] The total haze of Example 3 is 2.0%. It can be seen that the internal haze of Example 3 is 2.0%, and the external haze of Example 3 originating from the surface of the transparent substrate layer is substantially 0%, less than 0.1%. The arithmetic mean roughness Sa of the contact surface of Example 3 is 13 nm. The haze of the dimming sheet 11 in the opaque state of Example 3 is 98%, and the haze of the dimming sheet 11 in the transparent state is 8%.

[0148] The total haze of Comparative Example 1 is 0.0%. It can be seen that the internal haze of Comparative Example 1 is 0.0%, and the external haze originating from the surface of the transparent substrate layer of Comparative Example 1 is 0%. The arithmetic mean roughness Sa of the contact surface of Comparative Example 1 is 1 nm. The haze of the dimming sheet 11 in the opaque state of Comparative Example 1 is 98%, and the haze of the dimming sheet 11 in the transparent state is 6%. The distribution of the spacers can be seen in the transmission observation of Comparative Example 1.

[0149] The total haze of Comparative Example 2 is 4.0%. It can be seen that the internal haze of Comparative Example 2 is 4.0%, and the external haze originating from the surface of the transparent substrate layer of Comparative Example 2 is 0%. The arithmetic mean roughness Sa of the contact surface of Comparative Example 2 is 15 nm. The haze of the dimming sheet 11 in the opaque state of Comparative Example 2 is 98%, and the haze of the dimming sheet 11 in the transparent state is 11%. No spacer distribution is observed in the transmission observation of Comparative Example 2.

[0150] The total haze of Comparative Example 3 is 2.0%. It can be seen that the internal haze of Comparative Example 3 is 0.4%, and the external haze of Comparative Example 3 originating from the surface of the transparent substrate layer is 1.6%. The arithmetic mean roughness Sa of the contact surface of Comparative Example 3 is 25 nm. The haze of the dimming sheet 11 in the opaque state of Comparative Example 3 is 97%. On the other hand, as in Examples 1 to 3, when a voltage signal is supplied to the dimming sheet 11, it can be seen that the dimming sheet 11 remains in an opaque state. That is, the dimming sheet 11 is not seen to become transparent.

[0151] It can be seen that Examples 1 to 3, Comparative Examples 1, and Comparative Example 2 have external hazes that satisfy the above-mentioned condition 1, and at these levels, the supply of a voltage signal can make the transition from an opaque state to a transparent state reversible. On the other hand, it can be seen that Comparative Example 3 has a high external haze that does not satisfy the above-mentioned condition 1, and it is difficult for the supply of a voltage signal in Comparative Example 3 to transition from an opaque state to a transparent state.

[0152] It can also be seen that Examples 1 to 3 have internal hazes that satisfy the above conditions 2 and 3, and at these levels, the uneven distribution of the spacers is not visible in the transparent state. On the other hand, it can be seen that Comparative Example 2 has a low internal haze that does not satisfy the above conditions 2 and 3, and the uneven distribution of the spacers can be seen in the transparent state in Comparative Example 2.

[0153] It can be seen that Examples 1 to 3 have internal hazes that satisfy the above conditions 2 and 3, and at these levels, they show a haze of 10% or less in a transparent state. On the other hand, it can be seen that Comparative Example 3 has a high internal haze that does not satisfy the above conditions 2 and 3, and in Comparative Example 3, a haze of more than 10% is shown in a transparent state.

[0154] According to the above-described embodiment, the following effects can be obtained.

[0155] (1) Since the external haze of the transparent substrate layer is less than 0.1%, if the surface of the transparent substrate layer is the electrode layer 14F, 14B, it is possible to suppress the occurrence of imbalance in the electric field acting between the two transparent substrate layers. If the surface of the transparent substrate layer is the orientation layer 13F, 13B, it is possible to suppress the occurrence of imbalance in the orientation control force acting between the two transparent substrate layers.

[0156] (2) Since the internal haze of the transparent substrate layer is 0.1% or more, or the sum of the internal hazes of the two transparent substrate layers is 0.2% or more, the scattering generated at the interface between the transparent resin layer and the spacer is hidden in the internal scattering of the transparent substrate layer.

[0157] (3) Since the internal haze of each transparent base material layer is 2.0% or less, or the sum of the internal haze of the two transparent base material layers is 4.0% or less, the transparency of the light-adjusting sheet 11 is not excessively impaired.

[0158] (4) It is difficult to obtain a completely uniform distribution of spacers in the light-adjusting layer 12, which results in the non-uniform presence of many spacers. Internal scattering of the transparent substrate layer as described in (2) and (3) above is particularly preferred to suppress the non-uniform visibility caused by the non-uniform presence of spacers.

[0159] (5) When the dimming sheet 11 is pasted on a transparent body, the external haze of the transparent substrate layer is reduced by the adhesive layer that joins the dimming sheet to the transparent body or causes deviations due to the adhesive layer. When an ultraviolet shielding film or an anti-scattering film is pasted on the dimming sheet 11, the external haze of the transparent substrate layer is reduced by the adhesive layer that joins the functional film to the dimming sheet 11 or causes deviations. From this aspect, the internal haze of the transparent substrate layer is not reduced by various adhesive layers and is difficult to change due to various adhesive layers. As a result, the internal scattering of the transparent substrate layer such as the above (2) and (3) preferably suppresses the uneven visibility caused by the uneven presence of spacers, especially in the structure of pasting on a transparent body or pasting a functional film.

[0160] (6) When the external haze of the electrode layers 14F and 14B supported by the support layers 15F and 15B is the external haze of the transparent base material layer, it is possible to suppress the occurrence of imbalance in the electric field acting between the two transparent base material layers.

[0161] (7) Since the internal haze of the transparent base material layer is realized by the particles present in the support layers 15F and 15B, it is also easy to adjust the internal haze of the transparent base material layer to a desired range.

[0162] (8) When the average particle size of the particles in the support layers 15F and 15B is 0.8 μm or more and 5.0 μm or less, the effectiveness of suppressing uneven visibility due to the presence of spacers is improved as described in (2) and (3) above.

[0163] (9) When the difference in refractive index between the base resin layer surrounding the particles and the particles is 0.01 to 0.05, it is easy to realize the internal haze of the support layers 15F and 15B to be 0.1% to 2.0%.

[0164] (10) If the arithmetic mean roughness Sa of the contact surface of the transparent substrate layer is less than 20 nm, since the arithmetic mean roughness Sa of the contact surface with the light-adjusting layer 12 is less than 20 nm, the unevenness of the electric field caused by the thickness deviation or shape deviation of the light-adjusting layer 12 can also be suppressed.

[0165] (11) If the haze of the transparent dimming sheet 11 is 6% or more and 10% or less, it is easy to ensure the transparency of the dimming sheet 11 while suppressing the uneven visibility of the spacers due to the internal haze of the transparent base layer.

[0166] The above-mentioned embodiment can also be implemented with the following modifications.

[0167] The internal haze of the two transparent substrate layers may be different from each other. In this case, when the two transparent substrate layers satisfy conditions 1 and 3, the internal haze of one transparent substrate layer may be substantially zero.

[0168] The internal haze of one transparent base material layer may be 0.1% or more and 2.0% or less as the sum of the internal hazes of two or more layers.

[0169] The first transparent substrate layer may further include a layer having the largest internal haze among the first transparent substrate layers on the first surface 11F side facing the first electrode layer 14F. In this case, the largest internal haze may be 0.1% or more and 2.0% or less, and the internal haze of the layers other than the layer having the internal haze may be substantially zero.

[0170] The second transparent substrate layer may further include a layer having the largest internal haze among the second transparent substrate layers on the second layer 11B side facing the second electrode layer 14B. In this case, the largest internal haze may be 0.1% or more and 2.0% or less, and the internal haze of the layers other than the layer having the internal haze may be substantially zero.

[0171] The first support layer 15F may further include a first surface layer. The first surface layer includes a first surface 11F as a side surface. In this case, the internal haze of the first surface layer may be greater than 0.1% and less than 2.0%, and the internal haze of each layer other than the first surface layer constituting the first transparent substrate layer may be substantially zero.

[0172] The second support layer 15B may further include a second surface layer. The second surface layer includes a second surface 11B as a side surface. In this case, the internal haze of the second surface layer may be 0.1% or more and 2.0% or less, and the internal haze of each layer other than the second surface layer constituting the second transparent substrate layer may be substantially zero.

[0173] [Note]

[0174] The following supplementary notes are technical concepts that can be derived from the above-mentioned implementation manner and the above-mentioned examples.

[0175] [Note 1]

[0176] A dimming sheet, characterized in that:

[0177] It comprises two transparent substrate layers each having an electrode layer and a light-adjusting layer located between the two transparent substrate layers.

[0178] The light-adjusting layer includes a transparent resin layer defining gaps, a liquid crystal composition filling the gaps, and a spacer defining the thickness of the light-adjusting layer.

[0179] The external haze of each transparent substrate layer is less than 0.1%, and the internal haze of each transparent substrate layer is greater than or equal to 0.1% and less than or equal to 2.0%.

[0180] [Note 2]

[0181] A dimming sheet, characterized in that:

[0182] It comprises two transparent substrate layers each having an electrode layer and a light-adjusting layer located between the two transparent substrate layers.

[0183] The light-adjusting layer includes a transparent resin layer defining gaps, a liquid crystal composition filling the gaps, and a spacer defining the thickness of the light-adjusting layer.

[0184] The external haze of each transparent substrate layer is less than 0.1%, and the sum of the internal haze of the two transparent substrate layers is 0.2% to 4.0%.

[0185] [Note 3]

[0186] The dimming sheet according to Supplement 1 or Supplement 2, wherein:

[0187] Each transparent substrate layer includes a support layer that supports the electrode layer.

[0188] The external haze of each transparent substrate layer is the external haze of the electrode layer supported by the transparent substrate layer.

[0189] The internal haze of each support layer is 0.1% or more and 2.0% or less.

[0190] [Note 4]

[0191] The dimming sheet according to Supplement 3, wherein:

[0192] Each support layer contains particles present within the support layer.

[0193] [Note 5]

[0194] The dimming sheet according to Supplement 4, wherein:

[0195] The average particle size of the particles is 0.8 μm or more and 5.0 μm or less.

[0196] [Note 6]

[0197] The dimming sheet according to Supplement 3, wherein:

[0198] Each supporting layer includes a base layer serving as a base for the electrode layer and a substrate supporting the base layer.

[0199] Each base layer contains particles present within the base layer.

[0200] [Note 7]

[0201] The light-adjusting sheet according to any one of Supplementary Notes 4 to 6, wherein:

[0202] The difference in refractive index between the base resin layer surrounding the particles and the particles is 0.01 or more and 0.05 or less.

[0203] [Note 8]

[0204] The light-adjusting sheet according to any one of Supplementary Notes 1 to 7, wherein:

[0205] The transparent substrate layer has a contact surface in contact with the light-adjusting layer.

[0206] The arithmetic mean roughness Sa of the contact surface is 20 nm or less.

[0207] [Note 9]

[0208] The light-adjusting sheet according to any one of Supplementary Notes 1 to 8, wherein

[0209] The haze of the light control sheet in the transparent state is 6% or more and 10% or less.

[0210] [Note 10]

[0211] A method for manufacturing a dimming sheet, characterized in that:

[0212] It includes the following steps:

[0213] A step of applying a coating liquid for forming a light-adjusting layer between two transparent substrate layers each having an electrode layer; and

[0214] The step of forming the dimming layer by curing the coating liquid,

[0215] The dimming layer includes a transparent resin layer defining gaps, a spacer buried in the transparent resin layer, and a liquid crystal composition filling the gaps.

[0216] The external haze of each transparent base material layer in the dimming sheet is less than 0.1%, and the internal haze of each transparent base material layer is greater than or equal to 0.1% and less than or equal to 2.0%.

[0217] [Note 11]

[0218] A method for manufacturing a dimming sheet, characterized in that:

[0219] It includes the following steps:

[0220] A step of applying a coating liquid for forming a light-adjusting layer between two transparent substrate layers each having an electrode layer; and

[0221] The step of forming the dimming layer by curing the coating liquid,

[0222] The dimming layer includes a transparent resin layer defining gaps, a spacer buried in the transparent resin layer, and a liquid crystal composition filling the gaps.

[0223] The external haze of each transparent substrate layer in the dimming sheet is less than 0.1%, and the sum of the internal haze of the two transparent substrate layers is 0.2% to 4.0%.

[0224] [Note 12]

[0225] The method for manufacturing a dimming sheet according to Supplement 10 or Supplement 11, wherein:

[0226] The formation of the transparent substrate layer includes the step of laminating the electrode layer on the support layer so that the external haze of each transparent substrate layer becomes the external haze of the electrode layer supported by the transparent substrate layer.

[0227] The support layer has an internal haze of 0.1% or more and 2.0% or less.

[0228] [Note 13]

[0229] The method for manufacturing a dimming sheet according to Supplementary Note 12, comprising the step of forming the support layer by laminating a base layer for laminating the electrode layer on a substrate,

[0230] The base layer contains particles present in the base layer.

[0231] Explanation of symbols

[0232] P1 First connection terminal

[0233] P2 Second connection terminal

[0234] 11 Dimming Sheet

[0235] 12 Dimming Layer

[0236] 13F First orientation layer

[0237] 13B Second orientation layer

[0238] 14F First electrode layer

[0239] 14B Second electrode layer

[0240] 15F First support layer

[0241] 15B Second support layer

[0242] 51 Drive unit

Claims

1. A dimming sheet, characterized in that: It comprises two transparent substrate layers each having an electrode layer and a dimming layer located between the two transparent substrate layers. The light-adjusting layer includes a transparent resin layer defining gaps, a liquid crystal composition filling the gaps, and a spacer defining a thickness of the light-adjusting layer. The external haze of each transparent substrate layer is less than 0.1%, and the internal haze of each transparent substrate layer is greater than or equal to 0.1% and less than or equal to 2.0%.

2. A dimming sheet, characterized in that: It comprises two transparent substrate layers each having an electrode layer and a dimming layer located between the two transparent substrate layers. The light-adjusting layer includes a transparent resin layer defining gaps, a liquid crystal composition filling the gaps, and a spacer defining a thickness of the light-adjusting layer. The external haze of each transparent substrate layer is less than 0.1%, and the sum of the internal haze of the two transparent substrate layers is 0.2% to 4.0%.

3. The dimming sheet according to claim 1 or 2, wherein: Each transparent substrate layer includes a support layer that supports the electrode layer. The external haze of each transparent substrate layer is the external haze of the electrode layer supported by the transparent substrate layer. The internal haze of each support layer is 0.1% or more and 2.0% or less.

4. The dimming sheet according to claim 3, wherein: Each support layer contains particles present within the support layer.

5. The dimming sheet according to claim 4, wherein: The particles have an average particle size of 0.8 μm or more and 5.0 μm or less.

6. The dimming sheet according to claim 3, wherein: Each supporting layer includes a base layer serving as a base for the electrode layer and a substrate supporting the base layer. Each base layer contains particles present within the base layer.

7. The dimming sheet according to claim 4, wherein: The difference in refractive index between the base resin layer surrounding the particles and the particles is 0.01 or more and 0.05 or less.

8. The dimming sheet according to claim 1 or 2, wherein: Each transparent substrate layer has a contact surface in contact with the dimming layer. The arithmetic mean roughness Sa of the contact surface is 20 nm or less.

9. The dimming sheet according to claim 1 or 2, wherein: The haze of the light-adjusting sheet in a transparent state is 6% or more and 10% or less.

10. A method for manufacturing a dimming sheet, characterized in that: It contains the following steps: A step of applying a coating liquid for forming a light-adjusting layer between two transparent substrate layers each having an electrode layer; and The step of forming the dimming layer by solidifying the coating liquid, The light-adjusting layer includes a transparent resin layer defining gaps, a spacer buried in the transparent resin layer, and a liquid crystal composition filling the gaps. The external haze of each transparent substrate layer in the dimming sheet is less than 0.1%, and the internal haze of each transparent substrate layer is greater than 0.1% and less than 2.0%.

11. A method for manufacturing a dimming sheet, characterized in that: It contains the following steps: A step of applying a coating liquid for forming a light-adjusting layer between two transparent substrate layers each having an electrode layer; and The step of forming the dimming layer by solidifying the coating liquid, The light-adjusting layer includes a transparent resin layer defining gaps, a spacer buried in the transparent resin layer, and a liquid crystal composition filling the gaps. The external haze of each transparent substrate layer in the dimming sheet is less than 0.1%, and the sum of the internal haze of the two transparent substrate layers is greater than or equal to 0.2% and less than or equal to 4.0%.

12. The method for manufacturing a dimming sheet according to claim 10 or 11, wherein: The forming of the transparent substrate layer includes the step of laminating the electrode layer on the supporting layer so that the external haze of each transparent substrate layer becomes the external haze of the electrode layer supported by the transparent substrate layer. The support layer has an internal haze of 0.1% or more and 2.0% or less.

13. The method for manufacturing a dimming sheet according to claim 12, comprising the step of forming the support layer by laminating a base layer for laminating the electrode layer on a substrate, The base layer contains particles present within the base layer.

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