Electrochromic sheets, laminates, eyeglass lenses and eyeglasses

Abstract

Providing electrochromic sheets, laminates, eyeglass lenses, and eyeglasses that enable rapid color development. [Solution] An EC sheet comprising a first substrate, a second substrate, an EC element, and a sealing portion, wherein the EC element has a first transparent electrode, a second transparent electrode, and an EC layer, and the visible light transmittance of the EC sheet changes within a range including 30% when a voltage is applied, and the impedance of the EC sheet is measured under the following measurement conditions, and the internal resistance per unit area obtained from the obtained Nyquist diagram using the following formula (1) is 250 Ω / cm². 2 The following is an electrochromic sheet. Internal resistance = Resistance 1 + (Resistance 2 - Resistance 1) × 2 ... (1) (Resistance 1 is the value at the intersection of the horizontal axis of the Nyquist plot and the graph of the Nyquist plot.) Resistor 2 is the real component of the point where the imaginary component of the graph is maximized in the low-frequency region of the graph.

Description

[Technical Field]

[0001] The present invention relates to electrochromic sheets, laminates, lenses for eyeglasses, and eyeglasses. [Background technology]

[0002] Electrochromism is a phenomenon in which a redox reaction occurs when a voltage is applied, resulting in a reversible change in color. Electrochromic devices, which utilize materials exhibiting electrochromism and control color by applying voltage, are known as devices that take advantage of this phenomenon.

[0003] An electrochromic element comprises, for example, an electrochromic layer that changes color and decolorizes upon application of voltage, and a transparent electrode. The transparent electrode sandwiches the electrochromic layer and is electrically connected to the electrochromic layer. (See, for example, Patent Document 1).

[0004] Electrochromic sheets, which incorporate electrochromic elements, are used, for example, as materials for eyewear such as sunglasses and wearable devices such as smart glasses. They are also used as components for adjusting light intensity (optical filters) in window materials and imaging devices. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-167317 [Overview of the project] [Problems that the invention aims to solve]

[0006] Electrochromic sheets are required to develop color quickly upon application of voltage, while also being able to maintain their color after development. In this respect, the electrochromic sheet described in Patent Document 1 has room for improvement.

[0007] This invention has been made in view of these circumstances, and aims to provide an electrochromic sheet capable of rapid color development. It also aims to provide a laminate having such an electrochromic sheet, a lens for eyeglasses, and eyeglasses having such a lens. [Means for solving the problem]

[0008] To solve the above problems, one aspect of the present invention includes the following aspects.

[0009] [1] An electrochromic sheet comprising a first substrate, a second substrate, an electrochromic element sandwiched between the first and second substrates, and a sealing portion sandwiched between the first and second substrates and defining a colored region set between the first and second substrates, wherein the electrochromic element has a first transparent electrode provided on the first substrate side, a second transparent electrode provided on the second substrate side, and an electrochromic layer sandwiched between the first and second transparent electrodes, arranged in the colored region, and colored by the application of voltage, wherein the visible light transmittance of the electrochromic sheet changes within a range including 30% by the application of voltage, and the internal resistance per unit area obtained from the obtained Nyquist diagram by the following formula (1) is 250 Ω / cm² when the impedance of the electrochromic sheet is measured under the following measurement conditions 2 The following is an electrochromic sheet. Internal resistance (Ω / cm) 2 )=Resistance 1+(Resistance 2-Resistance 1)×2…(1) (Here, resistance 1 refers to the value at the intersection of the horizontal axis of the Nyquist plot and the graph of the Nyquist plot.) Resistor 2 refers to the real component of the point where the imaginary component of the graph is maximized in the low-frequency region of the graph. (Measurement conditions) Response frequency range: 0.1Hz to 1MHz Applied voltage conditions: Voltage and time at which the visible light transmittance reaches 30%.

[0010] [2] It has a first auxiliary electrode electrically connected to the first transparent electrode and a second auxiliary electrode electrically connected to the second transparent electrode, and the first auxiliary electrode and the second auxiliary electrode are separated in the circumferential direction of the coloring region and are arranged around the coloring region. The electrochromic sheet according to [1].

[0011] [3] The electrochromic layer has a first electrochromic layer laminated on the first transparent electrode, a second electrochromic layer laminated on the second transparent electrode, and an electrolyte layer filled between the first electrochromic layer and the second electrochromic layer. The first electrochromic layer contains a material that exhibits coloring by an oxidation reaction, and the second electrochromic layer contains a material that exhibits coloring by a reduction reaction. The electrochromic sheet according to [1] or 2.

[0012] [4] A laminate comprising the electrochromic sheet according to any one of [1] to [3] and a lens material on which the electrochromic sheet is laminated.

[0013] [5] An electrochromic part obtained by cutting the electrochromic sheet according to any one of [1] to [3], and a lens body on which the electrochromic part is laminated. A spectacle lens.

[0014] [6] A spectacle comprising the spectacle lens according to [5] and a frame for holding the spectacle lens, wherein the spectacle lens is electrically connected to the frame. [Advantages of the Invention]

[0015] According to the present invention, an electrochromic sheet capable of rapid color development can be provided. Further, a laminate having such an electrochromic sheet, a spectacle lens, and a spectacle having the spectacle lens can be provided. [Brief Description of the Drawings]

[0016] [Figure 1] Figure 1 is a perspective view showing sunglasses (glasses) using the electrochromic sheet of the embodiment as a material. [Figure 2] Figure 2 is an exploded perspective view of the electrochromic sheet 150. [Figure 3] Figure 3 is a partial cross-sectional view taken along line III-III of Figure 2. [Figure 4] Figure 4 is a plan view showing an example of the EC sheet 150. [Figure 5] Figure 5 is an example of a Nyquist diagram obtained from the AC impedance measurement results of an EC sheet with a fast coloring speed. [Figure 6] Figure 6 is an example of a Nyquist diagram obtained from the AC impedance measurement results of an EC sheet with a slow coloring speed. [Figure 7] Figure 7 is an explanatory diagram for explaining a method of manufacturing a lens using the EC sheet 150. [Figure 8] Figure 8 is a Nyquist diagram created for the EC sheets of Examples 1 to 3 and Comparative Example 1.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the electrochromic sheet, laminate, spectacle lens, and spectacles according to the present embodiment will be described with reference to FIGS. 1 to 7. In all the following drawings, for the sake of easy viewing of the drawings, the dimensions, ratios, etc. of each component are appropriately different. Further, in the following description, the term "electrochromic" may be abbreviated as "EC".

[0018] ≪Spectacles≫ Figure 1 is a perspective view showing sunglasses (glasses) using the electrochromic sheet (EC sheet) of the present embodiment as a material. Sunglasses are an example of spectacles.

[0019] In this specification, the term "glasses" refers to all devices (all types of eyewear) that are worn on the user's head in a position where the lenses are positioned in front of the user's eyes. In this definition, "glasses" includes not only ordinary glasses that correct the user's vision, but also known eyewear such as sunglasses and goggles that protect the user's eyes, and smart glasses (wearable devices) that display information on the lenses.

[0020] As shown in Figure 1, the sunglasses 100 comprises a pair of lenses 110 (eyeglass lenses) and a frame 120.

[0021] [lens] Lens 110 has visible light transmittance and can be reversibly colored and decolorized by switching the applied voltage. In this specification, "lens (eyeglass lens)" includes both those with a light-gathering function and those without a light-gathering function.

[0022] The lens 110 has an electrochromic portion 111 (EC portion 111) formed from an EC sheet, which will be described later, and a lens body 115 on which the EC portion 111 is laminated. When the user wears the sunglasses 100, the lens body 115 is on the user's side, and the EC portion 111 is on the side of the lens body 115 opposite to the user.

[0023] [Frame] The frame 120 comprises a pair of rim sections 121, a bridge section 122, a pair of temple sections 123, and a pair of nose pad sections 124. The frame 120 is worn on the user's head. The frame 120 positions the lens 110 in front of the user's eyes.

[0024] The rim portion 121 is formed in a closed annular shape. The pair of rim portions 121 correspond to the user's right and left eyes, respectively. The rim portion 121 may also be an open annular shape. Furthermore, the frame 120 may have a configuration without rim portions 121.

[0025] The bridge portion 122 connects the pair of rim portions 121 to each other. When worn on the user's head, the bridge portion 122 is positioned in front of the upper part of the user's nose.

[0026] The pair of temple sections 123 are connected to the rim section 121 at positions opposite to where the bridge section 122 is connected. When the glasses are worn on the wearer's head, the temple sections 123 are placed over the wearer's ears.

[0027] The temple portion 123 has a switch 125 and a battery 126. The switch 125 is exposed on the outer surface of the temple portion 123. The switch 125 is electrically connected to the lens 110 via wiring. The switch 125 can switch between applying a positive voltage, applying a negative voltage, and not applying any voltage to the lens 110.

[0028] The battery 126 is built into the temple portion 123. The battery 126 is electrically connected to the lens 110 via wiring.

[0029] The nose pad portion 124 is formed on each rim portion 121 at a position corresponding to the user's nose. The nose pad portion 124 comes into contact with the user's nose. The nose pad portion 124 stabilizes the wearing state of the sunglasses 100.

[0030] For example, metal materials, resin materials, etc., can be used as the constituent materials of the frame 120. The shape of the frame 120 is not limited to the illustrated example, as long as it can be worn on the user's head.

[0031] ≪Electrochromic Sheet≫ Figure 2 is an exploded perspective view of the electrochromic sheet 150 (EC sheet 150), and Figure 3 is a partial cross-sectional view along the line segment III-III in Figure 2. The EC sheet 150 is used as a material for eyeglass lenses, which will be described later.

[0032] As shown in Figures 2 and 3, the EC sheet 150 includes a first substrate 11, a second substrate 12, an electrochromic element 30 (EC element 30), and a sealing portion 40. In Figure 2, the sealing portion 40 is omitted.

[0033] The first substrate 11 and the second substrate 12 sandwich the EC element 30 and the sealing portion 40. The sealing portion 40 is positioned around the EC element 30 between the first substrate 11 and the second substrate 12, and demarcates the area between the first substrate 11 and the second substrate 12. The area demarcated by the sealing portion 40 is a colored region AR whose color changes when a voltage is applied.

[0034] [First substrate, second substrate] The first substrate 11 and the second substrate 12 are the outermost layers of the EC sheet 150. The first substrate 11 and the second substrate 12 are arranged facing each other and function as protective layers to protect the EC element 30 and the like.

[0035] The first substrate 11 and the second substrate 12 are transparent to visible light. In this specification, the term "transparent" may be used to describe the transparency of a material. The term "transparency" may also be used to describe the transparency of a material. If transparent, the first substrate and the second substrate 12 may be colorless or colored.

[0036] The first substrate 11 and the second substrate 12 contain a transparent thermoplastic resin as the main material. Examples of such resins include acrylic resins, polystyrene resins, polyethylene resins, polypropylene resins, polyester resins (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.), polycarbonate resins, polyamide resins, cycloolefin resins, vinyl chloride resins, polyacetal resins, triacetylcellulose (TAC), and the like.

[0037] The materials for the first substrate 11 and the second substrate 12 may be one of the above-mentioned resins, or two or more may be used in combination. Polycarbonate resins or polyamide resins are preferred as the materials for the first substrate 11 and the second substrate 12.

[0038] Furthermore, the materials of the first substrate 11 and the second substrate 12 may contain known fillers and additives, provided they are transparent. Also, the first substrate 11 and the second substrate 12 may be single layers or laminates.

[0039] The refractive indices of the first substrate 11 and the second substrate 12 at a wavelength of 589 nm are preferably 1.3 to 1.8, and more preferably 1.4 to 1.65. By setting the refractive indices of the first substrate 11 and the second substrate 12 within this range, the function of the electrochromic element 30 can be enhanced.

[0040] The average thickness of the first substrate 11 and the second substrate 12 is, for example, 0.05 mm or more and 10.0 mm or less, preferably 0.3 mm or more and 5.0 mm or less.

[0041] [Electrochromic element] The EC element 30 undergoes discoloration (coloring, decolorization) due to electrochromism caused by the application of voltage. The EC element 30 has a first transparent electrode 31, a second transparent electrode 32, and an electrochromic layer 35 (EC layer 35). The EC element 30 may also have a first auxiliary electrode 33 and a second auxiliary electrode 34.

[0042] (1st transparent electrode, 2nd transparent electrode) The first transparent electrode 31 is provided on the first substrate 11 side of the EC element 30 and is formed on the surface of the first substrate 11 facing the second substrate 12. The second transparent electrode 32 is provided on the second substrate 12 side of the EC element 30 and is formed on the surface of the second substrate 12 facing the first substrate 11.

[0043] In Figure 2, the first transparent electrode 31 is shown to have a protruding portion 31a in a position that overlaps with the first extraction portion 332, which will be described later, similar to the first extraction portion 332, but this portion 31a is not required. Similarly, the second transparent electrode 32 is shown to have a protruding portion 32a in a position that overlaps with the second extraction portion 342, which will be described later, similar to the second extraction portion 342, but this portion 32a is not required.

[0044] The first transparent electrode 31 and the second transparent electrode 32 are transparent. Examples of materials for the first transparent electrode 31 and the second transparent electrode 32 include oxides such as ITO, FTO (F-doped tin oxide), ATO (antitimony tin oxide), IZO (indium zinc oxide), In2O3, SnO2, Sb-containing SnO2, and Al-containing ZnO, as well as Au, Pt, Ag, Cu, or alloys containing these. One of these materials may be used for the first transparent electrode 31 and the second transparent electrode 32, or two or more may be used in combination.

[0045] The thicknesses of the first transparent electrode 31 and the second transparent electrode 32 are adjusted to ensure the necessary transparency while obtaining an electrical resistance value that allows an appropriate voltage to be applied to the EC layer 35. When ITO is used as the material for the first transparent electrode 31 and the second transparent electrode 32, the average thickness of the first transparent electrode 31 and the second transparent electrode 32 is, for example, 50 nm to 200 nm, preferably 50 nm to 150 nm, and more preferably 60 nm to 130 nm, independently of each other.

[0046] (1st auxiliary electrode, 2nd auxiliary electrode) The first auxiliary electrode 33 and the second auxiliary electrode 34 are spaced apart in the circumferential direction of the colored region AR and are positioned around the periphery of the colored region AR. As a result, the first auxiliary electrode 33 and the second auxiliary electrode 34 surround the colored region AR.

[0047] The first auxiliary electrode 33 is positioned around the colored region AR at the periphery of the first transparent electrode 31 and is electrically connected to the first transparent electrode 31. The first auxiliary electrode 33 has a strip-shaped first frame 331 and a first take-out portion 332 that protrudes from the first frame 331 to the outside of the colored region AR.

[0048] The first frame 331 surrounds a part of the EC layer 35, i.e., a part of the colored AR region. The first frame 331 is curved in plan view, but is not limited to this. When the lens 110 is assembled, the first frame 331 is positioned to surround the lens 110. The width of the first frame 331 is preferably, for example, 0.1 mm or more and 1.0 mm or less, and more preferably 0.3 mm or more and 1.0 mm or less.

[0049] The first removal section 332 is provided at one end of the first frame 331. When the lens 110 is in place, the first removal section 332 is positioned in the frame 120 near the bridge section 122 or the temple section 123.

[0050] The second auxiliary electrode 34 is positioned around the colored region AR on the peripheral surface of the second transparent electrode 32 and is electrically connected to the second transparent electrode 32. The second auxiliary electrode 34 has a strip-shaped second frame 341 and a second take-out portion 342 that protrudes from the second frame 341 to the outside of the colored region AR.

[0051] The second frame 341 surrounds a part of the EC layer 35, i.e., a part of the colored AR region. The second frame 341 is curved in plan view, but is not limited to this. When the lens 110 is assembled, the second frame 341 is positioned to surround the lens 110. The width of the second frame 341 is preferably, for example, 0.1 mm or more and 1.0 mm or less, and more preferably 0.3 mm or more and 1.0 mm or less.

[0052] The second outlet section 342 is provided at one end of the second frame 341. When the lens 110 is in place, the second outlet section 342 is positioned in the frame 120 near the bridge section 122 or the temple section 123.

[0053] The positions of the first outlet section 332 and the second outlet section 342 can be adjusted as appropriate according to the design of the lens 110 being manufactured.

[0054] As described later, when processing the EC sheet 150 into the lens 110, a through hole 40a is formed in the sealing portion 40 at a position that overlaps planarly with the first outlet portion 332, exposing the first outlet portion 332, and a conductive portion 51 is formed within the through hole 40a. The first outlet portion 332 is used as a connection point with the conductive portion 51. The formed conductive portion 51 is electrically connected to the first outlet portion 332 (first auxiliary electrode 33).

[0055] Similarly, in the sealing portion 40, a through hole is formed at a position that overlaps planarly with the second outlet portion 342, exposing the second outlet portion 342, and a conductive portion is formed within the through hole. The second outlet portion 342 is used as a connection point with the conductive portion. The formed conductive portion is electrically connected to the second outlet portion 342 (second auxiliary electrode 34).

[0056] The electrical resistance of the first auxiliary electrode 33 is lower than that of the first transparent electrode 31. Similarly, the electrical resistance of the second auxiliary electrode 34 is lower than that of the second transparent electrode 32. Examples of constituent materials for the first auxiliary electrode 33 and the second auxiliary electrode 34 include silver, aluminum, copper, chromium, and molybdenum. Conductive ink can also be used as the constituent material for the first auxiliary electrode 33 and the second auxiliary electrode 34. One of these materials may be used for the constituent materials of the first auxiliary electrode 33 and the second auxiliary electrode 34, or two or more may be used in combination. The first auxiliary electrode 33 and the second auxiliary electrode 34 can be formed by, for example, sputtering or vapor deposition. The first auxiliary electrode 33 and the second auxiliary electrode 34 can also be formed by printing using conductive ink.

[0057] The average thickness of the first auxiliary electrode 33 and the second auxiliary electrode 34 is preferably 1 nm to 300 nm, independently of each other. More preferably, the average thickness of the first auxiliary electrode 33 and the second auxiliary electrode 34 is 150 nm to 250 nm.

[0058] Figure 4 is a plan view showing an example of the EC sheet 150. As shown in Figure 4, the first auxiliary electrode 33 and the second auxiliary electrode 34 do not overlap with each other in a plan view and are located on opposite sides of the colored region AR in a plan view. Also, the first extraction section 332 does not overlap with the second transparent electrode 32, and the second extraction section 342 does not overlap with the first transparent electrode 31.

[0059] It is preferable that the difference between the total length of the first frame 331 and the total length of the second frame 341 be small, and preferably not more than twice the difference between them. For example, the total length of the first frame 331 is preferably more than 50% but less than 200% of the total length of the second frame 341, and more preferably 55% or more but 175% or less. Also, the total length of the first frame 331 is preferably 58% or more but 165% or less of the total length of the second frame 341, more preferably 61% or more but 155% or less, and even more preferably 65% ​​or more but 145% or less. Each upper limit and lower limit can be combined arbitrarily.

[0060] (Electrochromic layer) As shown in Figures 2 and 3, the EC layer 35 includes a first electrochromic layer 351 (first EC layer 351) laminated on the first transparent electrode 31, a second electrochromic layer 352 (second EC layer 352) laminated on the second transparent electrode 32, and an electrolyte layer 353 filled between the first EC layer 351 and the second EC layer 352.

[0061] (First electrochromic layer) The first EC layer 351 is a color-changing layer and mainly contains a material that is colored by an oxidation reaction. Examples of materials that are colored by an oxidation reaction include polymers of radical polymerizable compounds having a triarylamine structure, bisacridan compounds, triphenylamine, benzidine, Prussian blue type complexes, and nickel oxide, which are known materials that exhibit electrochromism and are used in EC elements.

[0062] Examples of polymers of radical polymerizable compounds having a triarylamine structure include those described in Japanese Patent Publication No. 2016-45464 and Japanese Patent Publication No. 2020-138925.

[0063] As materials that are colored by oxidation reactions, one of these may be used, or two or more may be used in combination.

[0064] The average thickness of the first EC layer 351 is preferably 0.1 μm or more and 30 μm or less. More preferably, the average thickness of the first EC layer 351 is 0.4 μm or more and 10 μm or less.

[0065] (Second electrochromic layer) The second EC layer 352 is a color-changing layer and mainly contains a material that is colored by a reduction reaction. Examples of materials that are colored by a reduction reaction include known materials that exhibit electrochromism and are used in EC elements, such as inorganic electrochromic compounds such as tungsten oxide, molybdenum oxide, iridium oxide, and titanium oxide, and organic electrochromic compounds such as viologen compounds and dipyridine compounds.

[0066] As the material that is colored by the reduction reaction, one of these may be used, or two or more may be used in combination.

[0067] The color produced by the oxidation reaction of the first EC layer 351 (color 1) and the color produced by the reduction reaction of the second EC layer 352 (color 2) may be the same hue or different hues. When color 1 and color 2 are the same hue, the maximum color intensity can be increased and the contrast can be improved. When color 1 and color 2 are different hues, the color produced by the EC element 30 will be the color obtained by mixing color 1 and color 2.

[0068] By coloring both the first EC layer 351 and the second EC layer 352, the redox pigments in both layers can be simultaneously colored. This improves the color development speed.

[0069] The average thickness of the second EC layer 352 is preferably 0.2 μm or more and 5.0 μm or less. More preferably, the average thickness of the second EC layer 352 is 1.0 μm or more and 4.0 μm or less. When the average thickness of the second EC layer 352 is 0.2 μm or more, the coloring density can be increased. When the average thickness of the second EC layer 352 is 5.0 μm or less, the manufacturing cost can be suppressed. When the average thickness of the second EC layer 352 is 5.0 μm or less, the decrease in visibility due to coloring is unlikely to occur.

[0070] (Electrolyte layer) The electrolyte layer 353 is filled between the first EC layer 351 and the second EC layer 352. The electrolyte layer 353 contains an electrolyte having ion conductivity.

[0071] Examples of the electrolyte include inorganic ion salts such as alkali metal salts and alkaline earth metal salts; supporting salts such as quaternary ammonium salts, acids, and alkalis. The counter ion (anion) of the electrolyte is halogen, thiocyanate ion (SCN - ), chlorate ion (ClO3 - ), perchlorate ion (ClO4 - ), tetrafluoroborate ion (BF4 - ), hexafluorophosphate ion (PF6 - ), trifluoromethanesulfonate ion (CF3SO3 - ), trifluoroacetate ion (CF3COO - ), and bisfluorosulfonium imide (N(SO2F)2 - ).

[0072] Specific examples of such electrolytes include LiClO4, LiBF4, LiAsF6, LiPF6, LiCF3SO3, LiCF3COO, KCl, NaClO3, NaCl, NaBF4, NaSCN, KBF4, Mg(ClO4)2, Mg(BF4)2, etc. As the electrolyte, one of these may be used, or two or more may be used in combination.

[0073] Ionic liquids can also be used as electrolyte materials. Among ionic liquids, organic ionic liquids are easy to handle because they have a molecular structure that exhibits liquid behavior over a wide temperature range, including room temperature.

[0074] The average thickness of the electrolyte layer 353 is preferably 20 μm or more and 100 μm or less. The average thickness of the electrolyte layer 353 is more preferably 30 μm or more and 80 μm or less, and even more preferably 30 μm or more and 70 μm or less.

[0075] [Sealing part] The sealing portion 40 is positioned between the first substrate 11 and the second substrate 12 and demarcates the colored region AR. The material of the sealing portion 40 is not particularly limited as long as it is a transparent insulating material. Examples of materials for the sealing portion 40 include resin materials such as acrylic resin and epoxy resin; and inorganic oxides such as silicon oxide (SiO2), silicon oxynitride (SiON), and aluminum oxide (Al2O3).

[0076] The average thickness of the sealing portion 40 is adjusted according to the average thickness of the EC element 30. The average thickness of the sealing portion 40 is preferably 20 μm to 100 μm, more preferably 30 μm to 80 μm, and even more preferably 40 μm to 60 μm.

[0077] Such an EC sheet 150 has the following effects, for example:

[0078] First, the EC sheet 150 described above is assumed to have a visible light transmittance that changes within a range including 30% when a voltage is applied. "The visible light transmittance changes within a range including 30%" means that the visible light transmittance of the EC sheet changes from a value higher than 30% to a value lower than 30%. In such an EC sheet, a visible light transmittance of 30% is achieved only when a voltage is applied.

[0079] The inventors conducted extensive research on the electrical characteristics of the EC sheet 150 in its colored state in order to achieve rapid color development. As a result, the inventors measured the AC impedance of the colored state under the following conditions, and the measured internal resistance value was 250 Ω / cm. 2 The invention was completed when it was discovered that the following EC sheet allows for rapid color development. (Measurement conditions) Response frequency range: 0.1Hz to 1MHz Applied voltage conditions: Voltage and time at which the visible light transmittance of EC sheet 150 becomes 30%.

[0080] In the above AC impedance measurement, the amplitude conditions were adjusted to obtain a Nyquist curve. For example, an amplitude of 10mV to 20mV is preferred.

[0081] Furthermore, after reaching a transmittance of 30%, the DC voltage application is stopped, and the AC impedance is measured with no voltage applied.

[0082] In this embodiment, "internal resistance value of the EC sheet" refers to the internal resistance value per unit area obtained from the Nyquist diagram obtained by measuring the impedance of the EC sheet 150 under the above measurement conditions.

[0083] Figures 5 and 6 are examples of Nyquist plots obtained from AC impedance measurements of EC sheets. Figure 5 shows the measurement results for an EC sheet with a fast color development rate, and Figure 6 shows the measurement results for an EC sheet with a slow color development rate. V1 and V2, shown in the legend, represent the voltage applied to the EC sheet.

[0084] AC impedance measurements were performed in a constant temperature bath at 25°C. The Nyquist plot is a complex plane showing the results of AC impedance measurements, where the horizontal axis represents the real component of impedance (resistance), and the vertical axis represents the imaginary component of impedance (capacitive reactance).

[0085] When performing AC impedance measurement on a circuit containing a capacitive component like an EC sheet, as shown in the graph of the Nyquist diagram in Fig. 5, a small arc is drawn in the high-frequency region (low-resistance region) (designated as symbol A in Fig. 5), and a substantially semi-circular locus is drawn in the low-frequency region (high-resistance region). At this time, in the Nyquist diagram, the real component (the real-axis intercept. Designated as symbols I1 and I2 in Fig. 5) of the point where the imaginary component of the graph is minimized in the low-frequency region corresponds to the internal resistance value of the circuit containing the capacitive component.

[0086] However, depending on the measurement conditions, the points indicated by symbols I1 and I2 in Fig. 5 may not be confirmed. Therefore, in this embodiment, the internal resistance value of the circuit containing the capacitive component shall be determined by the following formula (1). Internal resistance value (Ω / cm 2 ) = Resistance 1 + (Resistance 2 - Resistance 1) × 2 …(1) (Here, Resistance 1 refers to the value of the intersection point between the horizontal axis of the Nyquist diagram and the graph of the Nyquist diagram. Resistance 2 refers to the real component of the point where the imaginary component of the graph is maximized in the low-frequency region of the graph)

[0087] When the applied voltage for causing color development of the EC sheet is changed, the Nyquist diagram obtained by the above measurement changes, and the internal resistance value at that applied voltage is measured. In Fig. 5, the results of measurement with different applied voltages (V1, V2. However, V1 < V2) of AC voltage with the amplitude and response frequency shown in the above (measurement conditions) applied to the same EC sheet are shown.

[0088] Under the above premise, for an EC sheet with a fast color development speed, as shown in Fig. 5, the internal resistance value can be determined in the Nyquist diagram obtained by measurement, and the internal resistance value measured by applying the "voltage at which the visible light transmittance of the EC sheet becomes 30%" is 250 Ω / cm 2 is as follows.

[0089] For an EC sheet showing such an internal resistance value, it can be considered that the internal resistances of the first EC layer 351 and the second EC layer 352 are relatively small, and it is considered that the color development speed is fast.

[0090] In contrast, for EC sheets with a slow color development speed, as shown in Figure 6, the Nyquist plot obtained by measurement shows that the imaginary component diverges in the low-frequency region, and the graph does not trace a nearly semicircular trajectory. Alternatively, even if the graph does trace a nearly semicircular trajectory in the low-frequency region, the internal resistance value measured by applying the voltage at which the visible light transmittance of the EC sheet becomes 30% is 250 Ω / cm². 2 It shows a value exceeding this. In EC sheets with such high internal resistance, the color development speed is thought to be slower.

[0091] The internal resistance value obtained from the above measurement is 250 Ω / cm 2 The following is preferable: 200 Ω / cm 2 The following is more preferable, and even more preferably, 100 Ω / cm 2 The following applies: The lower limit of the internal resistance is, for example, 0.1 Ω / cm. 2 It may be greater than or equal to 1.0 Ω / cm 2 That's fine too.

[0092] The internal resistance of the EC sheet 150 is thought to be influenced by the internal resistances of the first EC layer 351 and the second EC layer 352. For example, the internal resistance of the first EC layer 351 can be reduced by making the layer thickness of the first EC layer 351 thinner and increasing the dye concentration. The internal resistance of the second EC layer 352 can also be reduced by controlling it in a similar way to the first EC layer 351.

[0093] The EC sheet 150 of this embodiment can achieve rapid color development by satisfying the above requirements.

[0094] <Laminated materials, eyeglass lenses> Figure 7 is an explanatory diagram illustrating a method for manufacturing lenses using the EC sheet 150.

[0095] First, as shown in Figure 7(a), the EC sheet 150 is bent under heating to curve it to match the curvature of the target lens. The bending process can be performed, for example, by press forming or vacuum forming.

[0096] Next, as shown in Figure 7(b), the curved EC sheet 150 is insert-molded as an insert part, and the lens material 119 is formed on the concave surface of the EC sheet 150 to obtain a laminate 160. The laminate 160 corresponds to the "laminated body" in this invention. The lens material 119 becomes the lens body 115 by processing as described later.

[0097] The lens material 119 has visible light transmittance. The material of the lens material 119 can be a thermoplastic resin known as a material for optical components.

[0098] It is preferable that the material of the lens material 119 is the same as or identical to the main material of the substrate (first substrate 11 or second substrate 12) that is in contact with the lens material 119 in the EC sheet 150, as this facilitates close contact between the EC sheet 150 and the lens material 119. Furthermore, if the substrate material and the lens material 119 material are the same as or identical to the lens material 119, the refractive index difference between the substrate and the lens material 119 can be reduced, thereby suppressing light scattering and reflection at the interface between the EC sheet 150 and the lens material 119. The refractive index difference between the substrate and the lens material 119 is preferably 0.2 or less, and more preferably 0.1 or less.

[0099] The thickness of the lens material 119 is preferably, for example, 1.5 mm or more and 20 mm or less. By setting the thickness of the lens material 119 within this range, it is possible to achieve both high strength and lightweight properties in the resulting lens.

[0100] Next, the surface of the lens material 119 is polished, the EC sheet 150 and the surface of the lens material 119 are hard-coated, and an anti-reflective treatment is performed. After that, a through hole is formed in the sealing portion 40 at a position overlapping with the first outlet portion 332 and the second outlet portion 342, through a hole exposing the first outlet portion 332 and through a hole exposing the second outlet portion 342. A conductive portion 51 that is electrically connected to the first outlet portion 331 and a conductive portion 52 that is electrically connected to the second outlet portion 341 are formed inside the through holes.

[0101] The conductive portions 51 and 52 can be formed by a conductive paste filled inside the through-hole and a conductive cylindrical member inserted inside the through-hole. In addition, any known material can be used as appropriate, as long as it is formed inside the through-hole and is electrically connectable to the first auxiliary electrode 33 (first outlet portion 332) and the second auxiliary electrode 34 (second outlet portion 342).

[0102] Next, as shown in Figure 7(c), the laminate 160 is trimmed to a shape corresponding to the rim portion 121 of the sunglasses 100 described above. At this time, the trimming around the first and second outlet portions 332 and 342 is performed, for example, using a rotating cylindrical grinding wheel G.

[0103] Through this processing, a lens 110 is obtained comprising an EC portion 111 obtained by cutting the EC sheet 150 and a lens body 115 on which the EC portion 111 is laminated (see Figure 1). In Figure 7, when cutting the laminate 160, the lens 110 is formed by cutting along the outer circumference of the first auxiliary electrode 33 and the second auxiliary electrode 34 of the EC sheet 150. The resulting lens 110 corresponds to the "eyeglass lens" in this invention.

[0104] The lens material 119 of the laminate 160 is processed into a lens body 115 by trimming along the outer circumference of the first auxiliary electrode 33 and the second auxiliary electrode 34. The lens body 115 has a protrusion 115a that is the same shape as the first outlet portion 332 and the second outlet portion 342 in a plan view.

[0105] Furthermore, if the first and second outlet portions 332 and 342 of the EC sheet 150 do not protrude outward from each auxiliary electrode, then the protruding portion 115a of the lens body 115 may be omitted.

[0106] The resulting lens 110 is combined with the frame 120 shown in Figure 1. At this time, the first outlet 332 and the second outlet 342 of the EC section 111 are electrically connected to the frame 120 via conductive parts provided therein. In this embodiment, the first outlet 332 and the second outlet 342 are electrically connected to external terminals (not shown) provided on the temple section 123 or bridge section 122 of the frame 120, and are connected to the battery 126. This will result in 100 sunglasses.

[0107] Because the auxiliary electrodes 33, 34 and sealing portion 40 of the EC sheet 150 are easily concealed, eyeglasses (sunglasses 100) to which the lens 110 is applied are preferable to those with a frame rather than those without a frame surrounding the lens (frameless). Similarly, for the same reason, eyeglasses to which the lens 110 is used are preferable to those with a frame that surrounds the entire lens rather than those with a half-rim type design.

[0108] The shape of lens 110 is not particularly restricted and can be adopted as appropriate depending on the design. For example, the lens shape can be matched to known frame shapes such as Wellington, browline, Boston, teardrop, Lexington, square, round, oval, and fox.

[0109] According to the electrochromic sheet with the above configuration, the occurrence of areas with poor color development is suppressed.

[0110] Furthermore, with laminates, eyeglass lenses, and eyeglasses having the above-described configuration, the presence of the electrochromic sheet results in a high-quality product with suppressed occurrence of areas with poor color development.

[0111] In this embodiment, sunglasses 100 are shown as an example of eyeglasses, but the invention is not limited to this. The lens 110 may be applied to goggles, for example, to protect the eyes from wind, rain, dust, chemicals, etc. Alternatively, the lens 110 may be applied to wearable devices such as smart glasses, which are worn on the user's head in a position where the lens 110 is positioned in front of the user's eyes.

[0112] Furthermore, although the EC layer 35 is provided with a first EC layer 351 and a second EC layer 352 in this embodiment, it is not limited to this configuration. The effects of the present invention can be achieved even if the EC layer 35 has only one of the first EC layer 351 and the second EC layer 352.

[0113] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but the present invention is not limited to these examples. The shapes and combinations of the constituent members shown in the above examples are merely examples, and can be modified in various ways based on design, specifications, etc., without departing from the spirit of the present invention. [Examples]

[0114] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0115] [Example 1] (Manufacturing of the electrolyte layer) The following binder resins, binder resin 2, and ionic liquid were mixed in a mass ratio of 18:7:75, and then a photopolymerization initiator was added at a concentration of 0.5% by mass relative to the total amount of binder resins 1 and 2 to prepare an electrolyte solution. Binder resin 1: Urethane acrylate (product name: UXF4002, manufactured by Nippon Kayaku Co., Ltd.) Binder resin 2: Crosslinked polymer having polymethyl methacrylate (PMMA) chains (product name: AA-6, manufactured by Toagosei Co., Ltd.) Ionic liquid 1: (EMIMFSI, ethylmethylimidazolium bisfluorosulfonimide, Kanto Chemical Co., Ltd.)

[0116] The obtained electrolyte solution was applied to the surface of a release-treated PET film (NP75C, manufactured by Panac Co., Ltd.), and then another release-treated PET film (NP75A, manufactured by Panac Co., Ltd.) was placed on top of it and UV irradiation was performed to create an electrolyte layer 353.

[0117] (Manufacturing of the first EC layer) A first transparent electrode 31 with a thickness of approximately 100 nm was formed by sputter deposition of ITO onto a 0.5 mm thick polycarbonate resin substrate (Polyca Ace, load deflection temperature 140°C, manufactured by Sumitomo Bakelite Co., Ltd.). The PC resin substrate corresponds to the first substrate 11.

[0118] A solution was prepared by mixing polyethylene glycol diacrylate (manufactured by Nippon Kayaku Co., Ltd., PEG400DA), a photoinitiator (manufactured by BASF, IRGACURE 184), a compound represented by the following formula (I) (compound I), and 2-butanone in a mass ratio of 57:3:140:800.

[0119] [ka] (In the formula, Me represents a methyl group.)

[0120] The prepared solution was spin-coated onto the first transparent electrode 31 to form a coating film. Next, under a nitrogen atmosphere, the coating film was UV-exposed through a predetermined exposure mask to selectively form a first EC layer 351 containing compound I on the first transparent electrode 31. The first EC layer 351 had a thickness of 1 μm and was patterned.

[0121] (Manufacturing of the second EC layer) A second transparent electrode 32 with a thickness of approximately 100 nm was formed by sputtering ITO onto a PC resin substrate (second substrate 12) similar to the first substrate 11.

[0122] 5.50 g of tin oxide solution (Celnax CX-S510M, manufactured by Nissan Chemical Industries, Ltd.), 1.00 g of ethylcellulose (10 cp, 10% by mass, ethanol solution), 0.50 g of tin(IV)tetra(t-butoxide), and 9.05 g of terpineol were mixed and treated with an ultrasonic homogenizer for 2 minutes, after which volatile components were removed with an evaporator to obtain a paste.

[0123] The obtained paste was screen printed onto the second transparent electrode 32 to a thickness of 2 μm, dried at 80°C, and then subjected to UV ozone treatment at 90°C for 20 minutes to form a porous tin oxide particle film.

[0124] A 1.5% by mass solution of compound (compound II) represented by the following formula (II) in 2,2,3,3-tetrafluoropropanol was spin-coated onto a tin oxide film, and the film was annealed at 80°C for 10 minutes to form a second EC layer 352 on which compound II was supported on the tin oxide film.

[0125] [ka]

[0126] (Manufacturing of EC sheets) An electrolyte layer 353 was laminated to the surface of the second EC layer 352. Subsequently, a sealing material (epoxy acrylate resin ("Photrex S-WF17," manufactured by Sekisui Material Solutions Co., Ltd.)) was applied using a dispenser to the area surrounding the sides of the second EC layer 352.

[0127] Subsequently, the first EC layer 351 of the first substrate 11 was bonded to the electrolyte layer 353, and the sealing material was spread by pressing for 60 seconds, thereby covering the sides of the first EC layer 351 and the second EC layer 352 with the sealing material. The resulting laminate was exposed to ultraviolet light (3 J / cm²). 2 After irradiation (preliminary curing), a heat curing treatment (final curing) was performed at 100°C for 1 hour to form a sealing portion, and the EC sheet of Example 1 was manufactured.

[0128] (Examples 2, 3, Comparative Example 1) Except for changing the spin-coating conditions to alter the film thickness of the first and second EC layers as shown in Table 1 below, EC sheets for Examples 2 and 3 and Comparative Example 1 were prepared in the same manner as in Example 1.

[0129] [Table 1]

[0130] AC impedance measurements were performed on the EC sheets of Examples 1-3 and Comparative Example 1 to determine the impedance per unit area. Furthermore, the color development speed was evaluated for each prepared EC sheet.

[0131] (AC impedance measurement conditions) Applied voltage: 0V Amplitude: 10mV Response frequency: 0.1Hz to 1MHz Measurement temperature: 25℃

[0132] Figure 8 shows the Nyquist plots created for the EC sheets of Examples 1-3 and Comparative Example 1. Table 2 shows the internal resistance and color development time for each EC sheet in the Examples and Comparative Examples. The internal resistance was defined as the real component (real axis intercept) of the point where the imaginary component of the graph is minimized in the low-frequency region in the Nyquist plot. The color development time is the time (in seconds) until the luminous transmittance reaches 30%.

[0133] [Table 2]

[0134] The study revealed a positive correlation between internal resistance and color development time, specifically when the internal resistance was 250 Ω / cm. 2 The following conditions were found to be preferable, as they resulted in a color development time of less than 30 seconds. [Explanation of Symbols]

[0135] 11...First substrate, 12...Second substrate, 30...Electrochromic element (EC element), 31...First transparent electrode, 32...Second transparent electrode, 33...First auxiliary electrode, 34...Second auxiliary electrode, 35...Electrochromic layer (EC layer), 40...Sealing part, 110...Lens, 111...Electrochromic part (EC part), 115...Lens body, 115a...Protruding part, 119...Lens material, 120...Frame, 150...Electrochromic sheet (EC sheet), 160...Laminate, 311, 312, 321, 322...Transparent electrode layer, 331...First frame, 331x, 341x...Other end, 332...First removal section, 341...Second frame, 342...Second removal section, 351...First electrochromic layer (First EC layer), 352...Second electrochromic layer (Second EC layer), 353...Electrolyte layer, AR...Colored area

Claims

1. First circuit board and The second circuit board and An electrochromic element sandwiched between the first substrate and the second substrate, An electrochromic sheet comprising a sealing portion sandwiched between the first substrate and the second substrate, which defines a colored region set between the first substrate and the second substrate, The electrochromic element comprises a first transparent electrode provided on the first substrate side, The second transparent electrode provided on the second substrate side, The device comprises an electrochromic layer sandwiched between the first transparent electrode and the second transparent electrode, positioned in the colored region, and colored by the application of a voltage, When a voltage is applied, the visible light transmittance of the electrochromic sheet changes within a range including 30%. The impedance of the electrochromic sheet was measured under the following measurement conditions, and the internal resistance per unit area, calculated from the obtained Nyquist plot using the following formula (1), was 250 Ω / cm². ２ The following is an electrochromic sheet. Internal resistance (Ω / cm) ２ ) = Resistance 1 + (Resistance 2 - Resistance 1) x 2 ... (1) (Here, resistance 1 refers to the value at the intersection of the horizontal axis of the Nyquist plot and the graph of the Nyquist plot.) Resistor 2 refers to the real component of the point where the imaginary component of the graph is maximized in the low-frequency region of the graph. (Measurement conditions) Response frequency range: 0.1 Hz to 1 MHz Applied voltage conditions: Voltage and time at which the visible light transmittance reaches 30%.

2. A first auxiliary electrode electrically connected to the first transparent electrode, The device comprises a second auxiliary electrode electrically connected to the second transparent electrode, The electrochromic sheet according to claim 1, wherein the first auxiliary electrode and the second auxiliary electrode are spaced apart in the circumferential direction of the colored region and are arranged around the colored region.

3. The electrochromic layer comprises a first electrochromic layer laminated on the first transparent electrode, A second electrochromic layer laminated on the second transparent electrode, The material comprises an electrolyte layer filled between the first electrochromic layer and the second electrochromic layer, The first electrochromic layer comprises a material that exhibits coloration through an oxidation reaction. The electrochromic sheet according to claim 1 or 2, wherein the second electrochromic layer comprises a material that exhibits coloration by a reduction reaction.

4. The electrochromic sheet according to claim 1 or 2, A laminate comprising a lens material on which the electrochromic sheets are laminated.

5. An electrochromic portion obtained by cutting the electrochromic sheet according to claim 1 or 2, An eyeglass lens comprising a lens body on which the electrochromic portion is laminated.

6. The eyeglass lens described in claim 5, The eyeglasses comprises a frame for holding the aforementioned eyeglass lenses, The aforementioned eyeglasses lenses are electrically connected to the frame.

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