Electrochromic sheet, laminate, eyeglass lens and eyeglasses

Abstract

To provide an electrochromic sheet, a laminate, a lens for spectacles, and spectacles capable of 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% upon application of a voltage, and the impedance of the EC sheet is measured under the following measurement conditions, and the internal resistance per unit area calculated from the obtained Nyquist diagram using the following formula (1) is 250 Ω / cm. 2 Below is the electrochromic sheet. Internal resistance = Resistor 1 + (Resistor 2 - Resistor 1) x 2…(1) (Resistance 1 is the value at the intersection of the horizontal axis of the Nyquist diagram and the graph of the Nyquist diagram. Resistor 2 is the real component of the point where the imaginary component of the graph is maximum in the low frequency region of the graph)

Description

[Technical Field]

[0001] The present invention relates to an electrochromic sheet, a laminate, an eyeglass lens, and eyeglasses. [Background technology]

[0002] Electrochromism is a phenomenon in which an applied voltage causes a redox reaction, resulting in a reversible color change. Electrochromic elements, which utilize this phenomenon and control the color by applying a voltage using electrochromic materials, are known.

[0003] An electrochromic element includes, for example, an electrochromic layer that develops or loses color when a voltage is applied, and transparent electrodes that sandwich the electrochromic layer and are electrically connected to the electrochromic layer (see, for example, Patent Document 1).

[0004] Electrochromic sheets equipped with 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 light-adjusting components (optical filters) in windows and imaging devices. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-167317 Summary of the Invention [Problem to be solved by the invention]

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

[0007] The present invention has been made in view of the above circumstances, and aims to provide an electrochromic sheet capable of rapid color development, as well as a laminate including such an electrochromic sheet, an eyeglass lens, and eyeglasses including the eyeglass lens. [Means for solving the problem]

[0008] In order 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 substrate and the second substrate, and a sealing portion sandwiched between the first substrate and the second substrate and defining a colored region set between the first substrate and the second substrate, 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 transparent electrode and the second transparent electrode, disposed in the colored region, and colored by application of a voltage; the visible light transmittance of the electrochromic sheet changes within a range including 30% by application of a voltage; and the impedance of the electrochromic sheet is measured under the following measurement conditions, and the internal resistance per unit area calculated from the obtained Nyquist diagram using the following formula (1) is 250 Ω / cm 2 Below is the 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 diagram and the graph of the Nyquist diagram. Resistor 2 is than resistor 1 low frequency of (The real component of the point in the region where the imaginary component of the graph is maximum.) (Measurement conditions) Frequency response: 0.1Hz to 1MHz range Applied voltage conditions: voltage and time at which the visible light transmittance becomes 30%

[0010] [2] An electrochromic sheet according to [1], comprising a first auxiliary electrode electrically connected to the first transparent electrode and a second auxiliary electrode electrically connected to the second transparent electrode, the first auxiliary electrode and the second auxiliary electrode being spaced apart in the circumferential direction of the colored region and being arranged around the colored region.

[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, wherein the first electrochromic layer contains a material that exhibits coloration by an oxidation reaction, and the second electrochromic layer contains a material that exhibits coloration by a reduction reaction [1], or [2] The electrochromic sheet according to claim 1.

[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] A spectacle lens comprising an electrochromic portion obtained by cutting the electrochromic sheet described in any one of [1] to [3], and a lens body on which the electrochromic portion is laminated.

[0014] [6] Eyeglasses comprising the eyeglass lens according to [5] and a frame that holds the eyeglass lens, wherein the eyeglass lens is electrically connected to the frame. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide an electrochromic sheet capable of rapid color development, a laminate including such an electrochromic sheet, an eyeglass lens, and eyeglasses including the eyeglass lens. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing sunglasses (eyeglasses) using the electrochromic sheet of the embodiment as a material. [Figure 2] FIG. 2 is an exploded perspective view of the electrochromic sheet 150. As shown in FIG. [Figure 3] FIG. 3 is a partial cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a plan view showing an example of the EC sheet 150. As shown in FIG. [Figure 5] FIG. 5 shows an example of a Nyquist diagram obtained from the AC impedance measurement results of an EC sheet with a fast color development speed. [Figure 6] FIG. 6 shows an example of a Nyquist diagram obtained from the AC impedance measurement results of an EC sheet with a slow color development speed. [Figure 7] FIG. 7 is an explanatory diagram illustrating a method for manufacturing a lens using the EC sheet 150. [Figure 8] FIG. 8 is a Nyquist diagram created for the EC sheets of Examples 1 to 3 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0017] The electrochromic sheet, laminate, eyeglass lens, and eyeglasses according to the present embodiment will be described below with reference to Figures 1 to 7. In all of the following drawings, the dimensions and proportions of each component have been appropriately changed to make the drawings easier to understand. In the following description, the term "electrochromic" may be abbreviated as "EC."

[0018] ≪Glasses≫ 1 is a perspective view showing sunglasses (eyeglasses) made from the electrochromic sheet (EC sheet) of this embodiment. Sunglasses are an example of eyeglasses.

[0019] In this specification, the term "eyeglasses" refers to any device (eyewear in general) worn on the user's head with lenses positioned in front of the user's eyes. In this definition, "eyeglasses" includes not only regular eyeglasses that correct the user's vision, but also well-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 FIG. 1, sunglasses 100 include a pair of lenses 110 (eyeglass lenses) and a frame 120.

[0021] [lens] Lens 110 is transparent to visible light and can reversibly develop or fade color by switching the voltage applied. In this specification, the term "lens (eyeglass lens)" includes both lenses with and without a light-condensing function.

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

[0023] Frame The frame 120 includes a pair of rim portions 121, a bridge portion 122, a pair of temple portions 123, and a pair of nose pad portions 124. The frame 120 is worn on the head of a user. The frame 120 positions the lenses 110 in front of the eyes of the user.

[0024] The rim portions 121 are formed in a closed ring shape. The pair of rim portions 121 correspond to the right and left eyes of the user, respectively. The rim portions 121 may be in an open ring shape. Furthermore, the frame 120 may not have the rim portions 121.

[0025] The bridge portion 122 connects the pair of rim portions 121. When worn on the user's head, the bridge portion 122 is located in front of the top of the user's nose.

[0026] The pair of temple portions 123 are connected to the rim portion 121 at positions opposite to the position where the bridge portion 122 is connected. The temple portions 123 are hooked over the user's ears when the glasses are worn on the user's head.

[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 a wire. The switch 125 can switch between applying a positive voltage, applying a negative voltage, and not applying a voltage to the lens 110, for example.

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

[0029] The nose pads 124 are formed on each rim 121 at positions corresponding to the nose of the user. The nose pads 124 come into contact with the nose of the user. The nose pads 124 stabilize the wearing state of the sunglasses 100.

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

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

[0032] 2 and 3, the EC sheet 150 has a first substrate 11, a second substrate 12, an electrochromic element 30 (EC element 30), and a sealing portion 40. In Fig. 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 disposed around the EC element 30 between the first substrate 11 and the second substrate 12, and partitions the space between the first substrate 11 and the second substrate 12. The area partitioned by the sealing portion 40 is a colored area AR whose color changes when a voltage is applied.

[0034] [First board, second board] 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 disposed opposite to each other and function as protective layers that protect the EC element 30 and the like.

[0035] The first substrate 11 and the second substrate 12 are visible light transmissive. In this specification, having visible light transmissive property may be referred to as "transparency." Visible light transmissive property may also be referred to as "transparency." If they are transparent, the first substrate 11 and the second substrate 12 may be colorless or colored.

[0036] First substrate 11 and second substrate 12 contain a transparent thermoplastic resin as a main material, such as acrylic resin, polystyrene resin, polyethylene resin, polypropylene resin, polyester resin (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.), polycarbonate resin, polyamide resin, cycloolefin resin, vinyl chloride resin, polyacetal resin, triacetyl cellulose (TAC), etc.

[0037] One of the above resins may be used, or two or more may be used in combination, as the material for the first substrate 11 and the second substrate 12. The material for the first substrate 11 and the second substrate 12 is preferably a polycarbonate-based resin or a polyamide-based resin.

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

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

[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, and preferably 0.3 mm or more and 5.0 mm or less.

[0041] [Electrochromic element] The EC element 30 changes color (coloring or decoloring) due to electrochromism caused by application of a 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] 2, the first transparent electrode 31 has a protruding portion 31a at a position overlapping a first extraction portion 332 (described later) similar to the first extraction portion 332, but this portion 31a may be absent. Similarly, the second transparent electrode 32 has a protruding portion 32a at a position overlapping a second extraction portion 342 (described later) similar to the second extraction portion 342, but this portion 32a may be absent.

[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 (antimony tin oxide), IZO (indium zinc oxide), In2O3, SnO2, Sb-containing SnO2, and Al-containing ZnO, as well as Au, Pt, Ag, Cu, and alloys containing any of these. The first transparent electrode 31 and the second transparent electrode 32 may be made of one of these materials or a combination of two or more of these materials.

[0045] The thickness of the first transparent electrode 31 and the second transparent electrode 32 is adjusted so as to ensure the necessary transparency and to obtain 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, independently set to 50 nm or more and 200 nm or less, preferably 50 nm or more and 150 nm or less, and more preferably 60 nm or more and 130 nm or less.

[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 arranged around the colored region AR, so that the first auxiliary electrode 33 and the second auxiliary electrode 34 surround the colored region AR.

[0047] The first auxiliary electrode 33 is disposed around the colored region AR on 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 body 331 and a first extraction portion 332 that protrudes from the first frame body 331 to the outside of the colored region AR.

[0048] The first frame 331 surrounds a portion of the EC layer 35, i.e., a portion of the colored region AR. The first frame 331 is curved in a plan view, but is not limited to this. When the first frame 331 is formed as the lens 110, the first frame 331 is provided in a position that surrounds the periphery of 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 extraction portion 332 is provided at one end of the first frame body 331. The first extraction portion 332 is provided at a position in the frame 120 that will be near the bridge portion 122 or the temple portion 123 when the lens 110 is formed.

[0050] The second auxiliary electrode 34 is disposed 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 body 341 and a second extraction portion 342 that protrudes from the second frame body 341 to the outside of the colored region AR.

[0051] The second frame 341 surrounds a portion of the EC layer 35, i.e., a portion of the colored region AR. The second frame 341 is curved in a plan view, but is not limited to this. When the second frame 341 is formed as the lens 110, the second frame 341 is provided in a position that surrounds the periphery of 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 extraction portion 342 is provided at one end of the second frame 341. The second extraction portion 342 is provided at a position in the frame 120 that will be near the bridge portion 122 or the temple portion 123 when the lens 110 is installed.

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

[0054] As will be described later, when the EC sheet 150 is processed into the lens 110, a through-hole 40a exposing the first extraction portion 332 is formed in the sealing portion 40 at a position overlapping the first extraction portion 332 in plan view, and a conductive portion 51 is formed in the through-hole 40a. The first extraction portion 332 is used as a connection point with the conductive portion 51. The formed conductive portion 51 is electrically connected to the first extraction portion 332 (first auxiliary electrode 33).

[0055] Similarly, a through hole exposing the second extraction portion 342 is formed in the sealing portion 40 at a position overlapping the second extraction portion 342 in plan view, and a conductive portion is formed in the through hole. The second extraction portion 342 is used as a connection point with the conductive portion. The formed conductive portion is electrically connected to the second extraction 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 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 material for the first auxiliary electrode 33 and the second auxiliary electrode 34. The first auxiliary electrode 33 and the second auxiliary electrode 34 may be made of one of these materials or a combination of two or more of these materials. 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 each of the first auxiliary electrode 33 and the second auxiliary electrode 34 is preferably 1 nm or more and 300 nm or less, and more preferably 150 nm or more and 250 nm or less.

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

[0059] The difference between the total length of the first frame 331 and the total length of the second frame 341 is preferably 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% and less than 200% of the total length of the second frame 341, and more preferably 55% to 175%. Furthermore, the total length of the first frame 331 is preferably 58% to 165% of the total length of the second frame 341, more preferably 61% to 155%, and even more preferably 65% ​​to 145%. The upper and lower limits can be combined in any manner.

[0060] (electrochromic layer) As shown in Figures 2 and 3, the EC layer 35 has a first electrochromic layer 351 (first EC layer 351) stacked on the first transparent electrode 31, a second electrochromic layer 352 (second EC layer 352) stacked 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 contains as its main material a material that changes color through oxidation. Examples of materials that change color through oxidation include known materials that exhibit electrochromism and are used in EC elements, such as polymers of radical polymerizable compounds having a triarylamine structure, bisacridan compounds, triphenylamine, benzidine, Prussian blue complexes, and nickel oxide.

[0062] Examples of polymers of radically polymerizable compounds having a triarylamine structure include those described in JP-A-2016-45464 and JP-A-2020-138925.

[0063] As the material that is colored by an oxidation reaction, one of these may be used, or two or more of them 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, and more preferably 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 contains, as its main material, a material that changes color through a reduction reaction. Examples of materials that change color through 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-based compounds and dipyridine-based compounds.

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

[0067] The color (color 1) that the first EC layer 351 acquires through an oxidation reaction and the color (color 2) that the second EC layer 352 acquires through a reduction reaction may be the same color tone or different color tones. When color 1 and color 2 have the same color tone, the maximum color density can be increased and contrast can be improved. When color 1 and color 2 have different color tones, the color that the EC element 30 acquires is 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 dyes of the first EC layer 351 and the second EC layer 352 can simultaneously develop colors, thereby improving 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. The average thickness of the second EC layer 352 is more preferably 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 color 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 reduced. When the average thickness of the second EC layer 352 is 5.0 μm or less, a 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 electrolytes include inorganic ion salts such as alkali metal salts and alkaline earth metal salts; and supporting salts such as quaternary ammonium salts, acids, and alkalis. Counterions (anions) of the electrolytes include halogens, thiocyanate ions (SCN - ), chlorate ion (ClO3 - ), perchlorate ion (ClO4 - ), tetrafluoroborate ion (BF4 - ), hexafluorophosphate ion (PF6 - ), trifluoromethanesulfonate ion (CF3SO3 - ), trifluoroacetate ion (CF3COO - ), bisfluorosulfonium imide (N(SO2F)2 - ) can be mentioned.

[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 of them may be used in combination.

[0073] Ionic liquids can also be used as electrolyte materials. Among ionic liquids, organic ionic liquids have a molecular structure that allows them to remain liquid over a wide temperature range, including room temperature, and are therefore easy to handle.

[0074] The average thickness of the electrolyte layer 353 is preferably 20 μm or more and 100 μm or less, 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 disposed between the first substrate 11 and the second substrate 12, and defines a colored area 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 (SiO), silicon oxynitride (SiON), and aluminum oxide (AlO).

[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 or more and 100 μm or less, more preferably 30 μm or more and 80 μm or less, and even more preferably 40 μm or more and 60 μm or less.

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

[0078] First, the visible light transmittance of the EC sheet 150 described above 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%. With such an EC sheet, a visible light transmittance of 30% is achieved only when a voltage is applied.

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

[0080] In the AC impedance measurement, the amplitude condition was adjusted so as to obtain a Nyquist diagram curve, and the amplitude condition is preferably, for example, 10 mV to 20 mV.

[0081] After the transmittance reaches 30%, the application of DC voltage is stopped and the AC impedance is measured in the state where no voltage is applied.

[0082] In this embodiment, the "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 diagrams obtained from the AC impedance measurement results of EC sheets. Figure 5 shows the measurement results for an EC sheet with a fast color-developing speed, and Figure 6 shows the measurement results for an EC sheet with a slow color-developing speed. V1 and V2 shown in the legend indicate the voltages applied to the EC sheet.

[0084] AC impedance measurements were performed in a thermostatic chamber at 25°C. A Nyquist diagram is a complex plane that shows the results of AC impedance measurements, and it is known that 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 an AC impedance measurement on a circuit containing a capacitive component such as 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 by reference numeral 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 (real-axis intercept; designated by reference numerals 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 designated by reference numerals I1 and I2 in Fig. 5 may not be confirmed. stomach Therefore, in the present embodiment, the internal resistance value of the circuit containing the capacitive component is 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 of the horizontal axis of the Nyquist diagram and the graph of the Nyquist diagram. Resistance 2 refers to the than resistor 1 real component of the point where the imaginary component of the graph is maximized in the of low-frequency region).)

[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 the applied voltage is measured. In Fig. 5, the results of measurements are shown for the same EC sheet with AC voltages of different applied voltages (V1, V2; where V1 < V2) having the amplitudes and response frequencies shown in the above (measurement conditions) applied.

[0088] Under the above premises, in an EC sheet with a fast color development rate, as shown in Fig. 5, the internal resistance value can be determined from 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 or less.

[0089] In an EC sheet exhibiting such an internal resistance value, the internal resistances of the first EC layer 351 and the second EC layer 352 are considered to be relatively small, and the color development speed is considered to be fast.

[0090] In contrast, for EC sheets with a slow color development speed, the imaginary component diverges in the low-frequency region in the Nyquist diagram obtained by measurement, as shown in Figure 6, and the graph does not trace a nearly semicircular locus. Even if the graph traces a nearly semicircular locus in the low-frequency region, the internal resistance measured by applying a voltage that makes the visible light transmittance of the EC sheet 30% is 250 Ω / cm. 2 It is thought that the color development speed is slower for EC sheets with such a high internal resistance.

[0091] The internal resistance value obtained by the above measurement is 250Ω / cm 2 Preferably less than 200Ω / cm 2 It is more preferable that it is equal to or less than 100 Ω / cm, and even more preferable that it is equal to or less than 100 Ω / cm 2 The lower limit of the internal resistance is, for example, 0.1 Ω / cm 2 It may be 1.0 Ω / cm or more. 2 It may be more than that.

[0092] The internal resistance value of the EC sheet 150 is considered to be affected 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 reducing the thickness of the first EC layer 351 and increasing the concentration of the dye. The internal resistance of the second EC layer 352 can also be reduced by controlling it in the same way as the first EC layer 351.

[0093] The EC sheet 150 of this embodiment satisfies the above requirements, thereby enabling rapid color development.

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

[0095] 7(a), the EC sheet 150 is first bent under heating to curve the EC sheet 150 to match the curvature of the target lens. The bending is performed by, for example, press molding or vacuum forming.

[0096] 7(b), the curved EC sheet 150 is insert-molded as an insert, and a 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 "laminate" of the present invention. The lens material 119 becomes the lens body 115 by processing as described below.

[0097] The lens material 119 has a visible light transmittance and may be made of a thermoplastic resin known as a material for optical members.

[0098] It is preferable that the material of the lens material 119 is the same as or the same as the main material of the substrate (first substrate 11 or second substrate 12) that contacts 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 materials of the substrate and the lens material 119 are the same as or the same, the difference in refractive index between the substrate and the lens material 119 can be reduced, and light scattering and reflection at the interface between the EC sheet 150 and the lens material 119 can be suppressed. The difference in refractive index 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 light weight for the obtained lens.

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

[0101] The conductive portions 51, 52 can be formed by a conductive paste filled in the through-holes or a conductive cylindrical member inserted in the through-holes. Alternatively, any known material can be used as appropriate as long as it is formed in the through-holes and can be electrically connected to the first auxiliary electrode 33 (first extraction portion 332) and the second auxiliary electrode 34 (second extraction portion 342).

[0102] 7(c), the laminate 160 is trimmed to a shape corresponding to the rim portion 121 of the above-described sunglasses 100. At this time, trimming of the peripheries of the first extraction portion 332 and the second extraction portion 342 is performed using, for example, a rotating cylindrical grindstone G.

[0103] By such processing, a lens 110 is obtained, which includes an EC portion 111 obtained by cutting the EC sheet 150 and a lens body 115 in which the EC portion 111 is laminated (see FIG. 1). In FIG. 7, when cutting the laminate 160, cutting is performed along the outer peripheries of the first auxiliary electrode 33 and the second auxiliary electrode 34 of the EC sheet 150 to obtain the lens 110. The obtained lens 110 corresponds to the "eyeglass lens" of the present invention.

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

[0105] If the first and second extraction portions 332 and 342 of the EC sheet 150 are configured not to protrude from the auxiliary electrodes to the outer periphery, the lens body 115 may not have the protrusion 115a.

[0106] The obtained lens 110 is combined with the frame 120 shown in Fig. 1. At this time, the first extraction portion 332 and the second extraction portion 342 of the EC portion 111 are electrically connected to the frame 120 via the conductive portions provided thereon. In this embodiment, the first extraction portion 332 and the second extraction portion 342 are electrically connected to external terminals (not shown) provided on the temple portion 123 or the bridge portion 122 of the frame 120, and are connected to the battery 126. This results in the sunglasses 100.

[0107] The eyeglasses (sunglasses 100) to which the lenses 110 are applied preferably have a framed design rather than a frameless design that does not have a frame surrounding the periphery of the lens, because this makes it easier to hide the auxiliary electrodes 33, 34 and the sealing portion 40 of the EC sheet 150. For the same reason, the eyeglasses to which the lenses 110 are applied preferably have a framed design that surrounds the entire periphery of the lens rather than a half-rim type design.

[0108] The shape of the lens 110 is not particularly limited and can be appropriately adopted depending on the design. For example, the lens shape can be a shape that matches known frame shapes such as Wellington, Thermont (brow), Boston, teardrop, Lexington, square, round, oval, and Fox.

[0109] According to the electrochromic sheet having the above-mentioned configuration, the occurrence of defective coloring areas is suppressed.

[0110] Furthermore, the laminate, eyeglass lens, and eyeglasses having the above-described configurations have high quality in which the occurrence of defective coloring areas is suppressed by including the electrochromic sheet.

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

[0112] In addition, in the present embodiment, the EC layer 35 includes the first EC layer 351 and the second EC layer 352, but this is not limitative. Even if the EC layer 35 includes only one of the first EC layer 351 and the second EC layer 352, the effects of the present invention can be achieved.

[0113] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on the design, specifications, etc., without departing from the spirit of the present invention. [Example]

[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] (Electrolyte layer manufacturing) The following binder resin 1, binder resin 2, and ionic liquid were mixed in a mass ratio of 18:7:75, and a photopolymerization initiator was further added in an amount of 0.5 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 Corporation), and a release-treated PET film (NP75A, manufactured by PANAC Corporation) was placed on top of it, followed by UV irradiation to produce an electrolyte layer 353.

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

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

[0119] [ka] (wherein Me represents a methyl group)

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

[0121] (Manufacturing the second EC layer) On a PC resin substrate (second substrate 12) similar to the first substrate 11, ITO was sputtered to form a film, and a second transparent electrode 32 having a thickness of approximately 100 nm was formed.

[0122] 5.50 g of tin oxide sol solution (Nissan Chemical Industries, Ltd., Celnax CX-S510M), 1.00 g of ethyl cellulose (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. The volatile components were then removed with an evaporator to obtain a paste.

[0123] The obtained paste was screen-printed on 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 mass% 2,2,3,3-tetrafluoropropanol solution of a compound represented by the following formula (II) (compound II) was spin-coated onto the tin oxide film, and annealed at 80°C for 10 minutes to form a second EC layer 352 in which compound II was supported on the tin oxide film.

[0125] [ka]

[0126] (EC sheet manufacturing) An electrolyte layer 353 was attached to the surface of the second EC layer 352. Next, a sealing material (epoxy acrylate resin ("Photolec S-WF17" manufactured by Sekisui Material Solutions Co., Ltd.) was applied using a dispenser to a position surrounding the periphery of the side surface of the second EC layer 352.

[0127] Thereafter, the first EC layer 351 of the first substrate 11 was attached to the electrolyte layer 353, and pressed for 60 seconds to spread the sealing material, thereby covering the side surfaces of the first EC layer 351 and the second EC layer 352 with the sealing material. The obtained laminate was irradiated with ultraviolet light (3 J / cm 2 ) (pre-curing), and then heat curing treatment (main curing) was carried out at 100°C for 1 hour to form sealed portions, thereby producing the EC sheet of Example 1.

[0128] (Examples 2 and 3, Comparative Example 1) The EC sheets of Examples 2 and 3 and Comparative Example 1 were produced in the same manner as in Example 1, except that the spin coating conditions were changed and the film thicknesses of the first EC layer and the second EC layer were changed as shown in Table 1 below.

[0129] [Table 1]

[0130] The impedance per unit area was determined by measuring the AC impedance of the EC sheets prepared in Examples 1 to 3 and Comparative Example 1. Furthermore, the color development speed of each of the prepared EC sheets was evaluated.

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

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

[0133] [Table 2]

[0134] As a result of the investigation, it was found that there was a positive correlation between the internal resistance and the coloring time, and that the internal resistance was 250 Ω / cm 2 It was confirmed that if the temperature is below this, the color development time is less than 30 seconds, which is preferable. [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 portion, 110...lens, 111...electrochromic portion (EC portion), 115...lens body, 115a...protrusion, 119...lens material, 120...frame, 150...electrochromic sheet (EC sheet), 160...laminated body, 311, 312, 321, 322...transparent electrode layer, 331...first frame body, 331x, 341x...other end, 332...first extraction portion, 341...second frame body, 342...second extraction portion, 351...first electrochromic layer (first EC layer), 352...second electrochromic layer (second EC layer), 353...electrolyte layer, AR...colored region

Claims

1. a first substrate; A second substrate; an electrochromic element sandwiched between the first substrate and the second substrate; a sealing portion sandwiched between the first substrate and the second substrate and defining a colored region set between the first substrate and the second substrate, The electrochromic element includes a first transparent electrode provided on the first substrate side; a second transparent electrode provided on the second substrate; an electrochromic layer that is sandwiched between the first transparent electrode and the second transparent electrode, that is disposed in the coloring region, and that is colored by application of a voltage; By applying a voltage, 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 diagram using the following formula (1) was 250 Ω / cm ２ Below is the electrochromic sheet. Internal resistance value (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 diagram and the graph of the Nyquist diagram. Resistor 2 indicates the real component of the point where the imaginary component of the graph is maximum in the lower frequency region than Resistor 1 on the graph.) (Measurement conditions) Response frequency: 0.1Hz to 1MHz range Applied voltage conditions: voltage and time at which the visible light transmittance becomes 30%

2. a first auxiliary electrode electrically connected to the first transparent electrode; 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 disposed around the colored region.

3. The electrochromic layer includes a first electrochromic layer laminated on the first transparent electrode; a second electrochromic layer laminated on the second transparent electrode; an electrolyte layer filled between the first electrochromic layer and the second electrochromic layer; the first electrochromic layer contains a material that exhibits color through an oxidation reaction; 3. The electrochromic sheet according to claim 1, wherein the second electrochromic layer contains a material that exhibits coloration through a reduction reaction.

4. The electrochromic sheet according to claim 1 or 2; and a lens material on which the electrochromic sheet is laminated.

5. an electrochromic part obtained by cutting the electrochromic sheet according to claim 1 or 2; and a lens body on which the electrochromic portion is laminated.

6. The eyeglass lens according to claim 5 ; a frame for holding the eyeglass lenses; The eyeglass lenses are electrically connected to the frame.

Images