JP7740587B1 - Electrochromic sheet, laminate, eyeglass lens, eyeglasses - Google Patents

Abstract

An electrochromic sheet is provided that can develop and fade color without delay.
[Solution] 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 first substrate has a first resin substrate and a first thermal expansion suppression layer provided on the first resin substrate, and the electrochromic element has a first transparent electrode provided on the first thermal expansion suppression layer side of the first substrate, a first auxiliary electrode arranged around the colored region, electrically connected to the first transparent electrode and including a sintered body of metal particles, 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, arranged in the colored region, and which becomes colored by the application of a voltage.
[Selected Figure] Figure 3

Description

The present invention relates to electrochromic sheets, laminates, eyeglass lenses, and eyeglasses.

Electrochromism is a phenomenon in which an oxidation-reduction reaction occurs when a voltage is applied, resulting in a reversible change in color. One known device that takes advantage of this phenomenon is an electrochromic device, which uses a material that exhibits electrochromism and controls color by applying a voltage.

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

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.

Japanese Patent Application Laid-Open No. 2017-167317

The transparent electrodes used in the configuration described in Patent Document 1 are formed using a material with high electrical conductivity and high visible light transmittance. Known transparent electrode materials include oxides such as ITO (indium tin oxide).

However, the above materials have higher electrical resistance than metal materials. As a result, in an electrochromic layer sandwiched between transparent ITO electrodes, there are areas where current flows easily and areas where it does not, which can easily lead to uneven color changes (coloring and fading) in the electrochromic layer.

The present invention was made in light of these circumstances, and aims to provide an electrochromic sheet that can develop and decolor without delay. It also aims to provide a laminate including such an electrochromic sheet, an eyeglass lens, and eyeglasses including the eyeglass lens.

To solve the above problem, the inventors investigated a configuration in which an auxiliary electrode is also used to supplement the conductivity of the transparent electrode. Auxiliary electrodes are generally formed using a metal material with lower electrical resistance than the material of the transparent electrode. During their investigation, the inventors discovered that when a resin substrate, which is more susceptible to thermal expansion than glass, is used as the substrate, the heating and baking process used to form the auxiliary electrode causes thermal expansion of the substrate, making the auxiliary electrode more susceptible to film peeling and cracking. In other words, they discovered that the auxiliary electrode may not be able to fully perform its expected functions. Based on this knowledge, the inventors conducted extensive research and completed the present invention.

To solve the above problems, one aspect of the present invention includes the following:

[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 first substrate comprises a first resin substrate and a first thermal expansion suppression layer provided on the first resin substrate, and the electrochromic element comprises a first transparent electrode provided on the first thermal expansion suppression layer side of the first substrate, a first auxiliary electrode arranged around the colored region, electrically connected to the first transparent electrode and including a sintered body of metal particles, 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, arranged in the colored region, and colored by the application of a voltage.

[2] The electrochromic sheet described in [1], wherein the second substrate further includes a second resin substrate and a second thermal expansion suppression layer provided on the second resin substrate, and the electrochromic element further includes a second auxiliary electrode disposed around the colored region, electrically connected to the second transparent electrode, and including the sintered body.

[3] The electrochromic sheet described in [2] further comprises either or both of a first electrode protective layer and a second electrode protective layer, wherein the first electrode protective layer is in contact with the first auxiliary electrode, the first auxiliary electrode is sandwiched between the first transparent electrode and the first electrode protective layer, the second electrode protective layer is in contact with the second auxiliary electrode, and the second auxiliary electrode is sandwiched between the second transparent electrode and the second electrode protective layer.

[4] An electrochromic sheet according to [2] or [3], wherein the first auxiliary electrode has a first opposing electrode portion extending along a portion of the outer periphery of the colored region, the second auxiliary electrode has a second opposing electrode portion extending along another portion of the outer periphery of the colored region, the second opposing electrode portion is on the opposite side of the colored region from the first opposing electrode portion and faces the first opposing electrode portion, and the width of the portion including at least one end of the first opposing electrode portion and the second opposing electrode portion is 0.1 mm or more and 2.0 mm or less.

[5] An electrochromic sheet according to [4], wherein the average thickness of the first auxiliary electrode and the second auxiliary electrode is 4 μm or less in a cross section of the first opposing electrode portion and the second opposing electrode portion that is 150 μm wide from the end of the colored region in the short direction.

[6] The electrochromic sheet described in any one of [2] to [5], wherein either or both of the first thermal expansion suppression layer and the second thermal expansion suppression layer are made of a curable resin containing a filler.

[7] The electrochromic sheet described in any one of [2] to [6], wherein either or both of the first auxiliary electrode and the second auxiliary electrode further contain an organic π-conjugated ligand.

[8] The electrochromic sheet described in any one of [2] to [7], wherein either or both of the first auxiliary electrode and the second auxiliary electrode have voids.

[9] An electrochromic sheet according to any one of [2] to [8], wherein either or both of the first resin substrate and the second resin substrate contain a thermoplastic resin, and the glass transition temperature of the thermoplastic resin is 200°C or lower.

[10] An electrochromic sheet according to any one of [2] to [9], wherein the first auxiliary electrode and the second auxiliary electrode are electrically connected to terminals for applying voltage independently at cross sections of the first auxiliary electrode and the second auxiliary electrode in the thickness direction.

[11] The electrochromic sheet described in any one of [1] to [10], wherein either or both of the first transparent electrode and the second transparent electrode contain indium oxide.

[12] An electrochromic sheet according to any one of [1] to [11], which has been plastically deformed.

[13] The electrochromic sheet according to any one of [1] to [12],
and a lens material on which the electrochromic sheet is laminated.

[14] An electrochromic part obtained by cutting the electrochromic sheet according to any one of [2] to [10] along the outer periphery of the first auxiliary electrode and the second auxiliary electrode;
and a lens body on which the electrochromic portion is laminated.

[15] Eyeglasses comprising the eyeglass lens described in [14] and a frame that holds the eyeglass lens, wherein the lens body is electrically connected to the frame.

The present invention provides an electrochromic sheet that can develop and decolorize without delay. It also provides a laminate including such an electrochromic sheet, an eyeglass lens, and eyeglasses including the eyeglass lens.

FIG. 1 is a perspective view showing sunglasses (eyeglasses) using the electrochromic sheet of the embodiment as a material. FIG. 2 is an exploded perspective view showing an example of the electrochromic sheet 150. As shown in FIG. Fig. 3(a) is a diagram showing an example of a partial cross section taken along line III-III in Fig. 2 (in the diagram, the arrow indicates that the contact portion between the conductive portion 52 and the terminal for applying voltage is on the upper surface of the sheet). Fig. 3(b) is a diagram showing an example of a partial cross section taken along line III-III when the electrochromic sheet 150 is processed into the lens 110 (in the diagram, the arrow indicates that the contact portion between the conductive portion 52 and the terminal for applying voltage is on the side surface of the lens). FIG. 4 is a plan view showing an example of the EC sheet 150. As shown in FIG. FIG. 5 is an explanatory diagram illustrating a method for manufacturing a lens using the EC sheet 150. 6(a) is a Nyquist diagram (display range of Z': 0Ω to 100Ω) created for the EC sheet of Example 1. FIG. 6(b) is a Nyquist diagram (display range of Z': 0Ω to 50,000Ω) created for the EC sheet of Example 1.

The electrochromic sheet, laminate, eyeglass lens, and eyeglasses according to this embodiment will be described below with reference to Figures 1 to 6. Note that in all of the following drawings, the dimensions and proportions of each component have been changed as appropriate to make the drawings easier to understand. In the following description, the term "electrochromic" may be abbreviated as "EC."

≪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.

In this specification, the term "eyeglasses" refers to any device (eyewear in general) worn on the user's head with the 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.

As shown in FIG. 1, sunglasses 100 include a pair of lenses 110 (eyeglass lenses) and a frame 120 that holds the lenses 100.

[lens]
The lens 110 is transparent to visible light and can reversibly develop or fade color by switching the application of voltage. In this specification, the term "lens (eyeglass lens)" includes both lenses having a light-condensing function and lenses having no light-condensing function.

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

[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 user's eyes.

The rim portions 121 are formed in a closed ring shape. The pair of rim portions 121 correspond to the user's right and left eyes, respectively. The rim portions 121 may also be open ring shaped. The frame 120 may also be configured without rim portions 121.

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 located in front of the top of the user's nose.

The pair of temple portions 123 are connected to the rim portion 121 at positions opposite to the position to which the bridge portion 122 is connected. The temple portions 123 are placed over the user's ears when wearing the glasses on the user's head.

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, a negative voltage, and no voltage to the lens 110, for example.

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

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 abuts against the user's nose. The nose pad portion 124 stabilizes the wearing state of the sunglasses 100.

The frame 120 can be made of, for example, a metal material, a resin material, or the like. The shape of the frame 120 is not limited to the example shown in the figure, as long as it can be worn on the user's head.

<Electrochromic Sheet>
Fig. 2 is an exploded perspective view showing an example of an electrochromic sheet 150. Fig. 3 is a diagram showing an example of 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.

As shown in Figures 2 and 3, the EC sheet 150 includes a first substrate 21, a second substrate 22, an electrochromic element 30 (EC element 30), and a sealing portion 40. The sealing portion 40 is omitted from Figure 2.

The first substrate 21 and the second substrate 22 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 21 and the second substrate 22, and separates the first substrate 21 and the second substrate 22. The region of the EC element 30 separated by the sealing portion 40 is the colored region AR, which changes color when a voltage is applied.

[First substrate, second substrate]
The first substrate 21 and the second substrate 22 are the outermost layers of the EC sheet 150. The first substrate 21 and the second substrate 22 are arranged opposite to each other, and hold the EC element 30 and the like, and also function as a protective layer that protects the EC element 30 and the like.

The first substrate 21 and the second substrate 22 are visible light transmissive. In this specification, being visible light transmissive is sometimes referred to as "transparency." Visible light transmissivity is also sometimes referred to as "transparency." If they are transparent, the first substrate 21 and the second substrate 22 may be colorless or colored.

The first substrate 21 has a first resin substrate 23 and a first thermal expansion suppression layer 24 provided on the first resin substrate.
When the electrochromic element described below has a second auxiliary electrode, the second substrate 22 preferably has a second resin substrate 26 and a second thermal expansion suppressing layer 25 provided on the second resin substrate.

In this specification, the term "provided on a resin substrate" refers to a first thermal expansion suppression layer being formed on a first resin substrate, either directly or via another layer, or a second thermal expansion suppression layer being formed on a second resin substrate, either directly or via another layer. The other layer is not particularly limited as long as it is transparent, but examples include an adhesion layer, a water vapor barrier layer, a gas barrier layer, and an optical adjustment layer.

(First Resin Substrate, Second Resin Substrate)
The first resin substrate 23 and the second resin substrate 26 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.
The first resin substrate 23 and the second resin substrate 26 may be made of one of the above resins, or a combination of two or more of them.

In particular, it is preferable that either or both of the first resin substrate 23 and the second resin substrate 26 contain a thermoplastic resin having a glass transition temperature of 200° C. or lower, and it is more preferable that both of the first resin substrate 23 and the second resin substrate 26 contain a thermoplastic resin having a glass transition temperature of 200° C. or lower. The upper limit of the glass transition temperature is more preferably 180° C. or lower, and even more preferably 160° C. or lower. When the glass transition temperature is equal to or lower than the upper limit, the thermal processability of the resin substrate is superior.
The lower limit of the glass transition temperature is not particularly limited, but is sufficient as long as it is 80° C. or higher, preferably 100° C. or higher, and more preferably 120° C. or higher. When the glass transition temperature is equal to or higher than the above lower limit, the heat resistance of the resin substrate becomes more excellent.
The above upper and lower limit values can be arbitrarily combined for the glass transition temperatures of the first resin substrate 23 and the second resin substrate 26. The thermoplastic resin having a glass transition temperature equal to or lower than the above temperature is preferably a polycarbonate-based resin, a polyester-based resin, or a polyamide-based resin.

The first resin substrate 23 and the second resin substrate 26 may contain known fillers and additives as long as they are transparent.

The first resin substrate 23 and the second resin substrate 26 may each be a single layer, or may be laminated in two or three layers.

The average thickness of the first resin substrate 23 and the second resin substrate 26 is, for example, 0.05 mm or more and 10.0 mm or less, preferably 0.1 mm or more and 5.0 mm or less.

(First Thermal Expansion Suppressing Layer, Second Thermal Expansion Suppressing Layer)
The first thermal expansion suppression layer 24 is provided on the first resin substrate 23. The first thermal expansion suppression layer 24 is less susceptible to thermal expansion than the first resin substrate 23. Therefore, deformation of the first auxiliary electrode 33 due to thermal expansion of the resin substrate 23 is suppressed when the auxiliary electrode (the first auxiliary electrode 33 or the second auxiliary electrode 34) is heated and baked or when the EC sheet is heated and bent, and peeling and cracking of the first auxiliary electrode 33 are less likely to occur.

The second thermal expansion suppression layer 25 is provided on the second resin substrate 26. The second thermal expansion suppression layer 25 is less susceptible to thermal expansion than the second resin substrate 26. Therefore, deformation of the second auxiliary electrode 34 due to thermal expansion of the second resin substrate 26 is suppressed when the auxiliary electrode is heated and baked or when the EC sheet is heated and bent, making peeling and cracking of the second auxiliary electrode 34 less likely to occur.

The first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 contain a transparent thermosetting resin or photocurable resin as a main material. Such curable resins are not particularly limited as long as they can suppress the thermal expansion of the first resin substrate 23 and the second resin substrate 26, respectively, but examples include acrylic resin, urethane resin, and epoxy resin. Resin materials with a cured resin glass transition temperature higher than that of the resin substrates on which the thermal expansion suppression layers are formed are particularly preferred. The high glass transition temperature of the cured resin effectively suppresses deformation of the auxiliary electrodes due to thermal expansion of the resin substrates during heating and baking of the auxiliary electrodes or heating and bending of the EC sheet.
The first thermal expansion suppressing layer 24 and the second thermal expansion suppressing layer 25 may be made of one of the above resins or a combination of two or more of them.

The content of the curable resin in the thermal expansion suppression layer 12 is not particularly limited, but it may be 20% by mass or more and 99.9% by mass or less, and preferably 30% by mass or more and 90% by mass or less, relative to the total amount of the thermal expansion suppression layer 12.

In particular, it is preferable that either or both of the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 be made of a curable resin containing a filler, and it is even more preferable that both the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 be made of a curable resin containing a filler.
The filler is not particularly limited as long as it is transparent. The filler material may have a smaller coefficient of linear thermal expansion than the resin substrate on which the thermal expansion suppression layer is formed, and it is preferable to select an inorganic material (oxide, nitride, metal, etc.). This is because inorganic materials have a smaller coefficient of linear thermal expansion than organic resin substrates. Specific examples of inorganic filler materials include silicon oxide, zirconia oxide, aluminum oxide, tin oxide, aluminum nitride, aluminum boride, various micas, Ag, Cu, Au, Ni, and carbon. The filler material may also have a core-shell structure consisting of multiple material structures. The filler material may be surface-treated with hydroxyl groups, acrylic groups, epoxy groups, etc., to suppress filler aggregation or improve mixability with the resin.
The filler may be in the form of a sphere, fiber, flake, hollow particle, etc., and the particle size of the filler may be from 2 nm to 500 μm, preferably from 10 nm to 10 μm. Fillers of different shapes or particle sizes may be mixed and used.

The filler content in the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 may be 1% by mass or more, and preferably 10% by mass or more and 200% by mass or less, relative to the total amount of the curable resin. By adjusting the filler content within the above numerical range, the ease of thermal expansion of the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 can be adjusted without impairing the effects of the present invention. For example, by increasing the filler content, the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 can be made less susceptible to thermal expansion. Furthermore, by reducing the filler content, the film quality of the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 can be further improved, and film defects can be further reduced.

If the material of the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 is transparent, it may contain known additives.

The first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 may each be a single layer, or may be laminated in two or three layers.

The average thickness of the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 is, for example, preferably 0.1 μm or more and 500 μm or less, more preferably 0.5 μm or more and 50 μm or less, and even more preferably 1 μm or more and 10 μm or less. When the average thickness of the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 is within the above numerical range, peeling or cracking of the sintered body is less likely to occur during heating and firing of the auxiliary electrode or heating and bending of the EC sheet. Furthermore, when the average thickness of the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25 is less than the above upper limit value, peeling or cracking of the thermal expansion suppression layer itself is less likely to occur during bending.

The refractive index of the first substrate 21 and the second substrate 22 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 21 and the second substrate 22 within this range, the functionality of the electrochromic element 30 can be improved.

By providing a thermal expansion suppression layer on the substrate, the electrochromic sheet of this embodiment is less likely to peel or crack when sintered, even when using a resin substrate that is more susceptible to thermal expansion than glass. This means that the auxiliary electrode in the electrochromic sheet of this embodiment is less likely to have high electrical resistance. This means that the range of materials that can be selected for the resin substrate can be expanded, and thermoplastic resins that are easy to process during the heating and firing of the auxiliary electrode and the heating and bending of the EC sheet can be used for the resin substrate.

[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 first auxiliary electrode 33, a second transparent electrode 32, and an electrochromic layer 35 (EC layer 35). The EC element 30 preferably has a second auxiliary electrode 34, and more preferably has either or both of a first electrode protective layer 36 and a second electrode protective layer 37.

(First transparent electrode, second transparent electrode)
The first transparent electrode 31 is provided on the first thermal expansion suppression layer 24 side of the first substrate 21 of the EC element 30, and is formed on the surface of the first substrate 21 facing the second substrate 22. The second transparent electrode 32 is provided on the second substrate 22 side of the EC element 30, and is formed on the surface of the second substrate 22 facing the first substrate 21.

In FIG. 2, the first transparent electrode 31 has a protruding portion 31a similar to the first extraction portion 332 at a position overlapping the first extraction portion 332 described below, but this portion 31a may be absent. Similarly, the second transparent electrode 32 has a protruding portion 32a similar to the second extraction portion 342 at a position overlapping the second extraction portion 342 described below, but this portion 32a may be absent.

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, F-doped tin oxide (FTO), antimony tin oxide (ATO), indium zinc oxide (IZO), In ₂ O ₃ , SnO ₂ , and Al-containing ZnO, Au, Pt, Ag, Cu, or alloys containing these, carbon, and conductive polymers. 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. Metallic materials with low transparency can be used as transparent electrodes by thinning them or forming them into a lattice shape to increase the voids.
In particular, it is preferable that either one or both of the first transparent electrode 31 and the second transparent electrode 32 contain indium oxide, as this provides superior density and transparency to the first transparent electrode 31 and the second transparent electrode 32. The inclusion of indium oxide makes it easier to protect the EC layer 35 from oxygen and water. More specifically, the auxiliary electrode containing indium oxide preferably contains ITO, IZO, ITO, or _In2O3 , and more preferably contains _ITO .
The first transparent electrode 31 and the second transparent electrode 32 may be made of the same material or different materials.

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 current to flow through 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.
The first transparent electrode 31 and the second transparent electrode 32 may be formed to have the same average thickness or different thicknesses.
Furthermore, since the first transparent electrode 31 and the second transparent electrode 32 are electrically connected to the first auxiliary electrode 31 and the second auxiliary electrode 32 arranged around the colored area AR, they are formed larger than the colored area AR and are formed to extend to the formation area of the sealing portion 40 or a part of the formation area.

(First auxiliary electrode, second auxiliary electrode)
The first auxiliary electrode 33 is disposed around the colored region AR in the peripheral portion of the first transparent electrode 31, is electrically connected to the first transparent electrode 31, and includes a sintered body of metal particles.

The first auxiliary electrode 33 includes a first opposing electrode portion 331 and a first extraction portion 332. The first opposing electrode portion 331 extends along part of the outer periphery of the colored region AR. The first opposing electrode portion 331 is formed away from the outer periphery of the colored region AR. The first extraction portion 332 protrudes from the first opposing electrode portion 331 to the outside of the colored region AR.

The first opposing electrode portion 331 surrounds a portion of the EC layer 35, i.e., a portion of the colored region AR. The first opposing electrode portion 331 is curved in a plan view, but is not limited to this. When the first opposing electrode portion 331 is formed as a lens 110, it is provided in a position that surrounds the periphery of the lens 110. The width of the first opposing electrode portion 331 is preferably, for example, 0.1 mm to 2.0 mm, and more preferably 0.3 mm to 1.0 mm.

The first extraction portion 332 is provided at one end of the first opposing electrode portion 331. When the lens 110 is formed, the first extraction portion 332 is provided in a position in the frame 120 that is near the bridge portion 122 or the temple portion 123.

When the EC element 30 has a second auxiliary electrode 34, 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. As a result, the first auxiliary electrode 33 and the second auxiliary electrode 34 surround the colored region AR.

The second auxiliary electrode 34 includes a second opposing electrode portion 341 and a second extraction portion 342. The second opposing electrode portion 341 extends along part of the outer periphery of the colored region AR. The second opposing electrode portion 341 is located on the opposite side of the colored region AR from the first opposing electrode portion 331 and faces the first opposing electrode portion 331. The second opposing electrode portion 341 is formed away from the outer periphery of the colored region AR. The second extraction portion 342 protrudes from the second opposing electrode portion 341 to the outside of the colored region AR.

The second opposing electrode portion 341 surrounds a portion of the EC layer 35, i.e., a portion of the colored region AR. The second opposing electrode portion 341 is curved in a plan view, but is not limited to this. When the second opposing electrode portion 341 is formed as a lens 110, it is provided in a position that surrounds the periphery of the lens 110. The width of the portion of the second opposing electrode portion 341 that includes at least one end is preferably, for example, 0.1 mm to 2.0 mm, and more preferably 0.3 mm to 1.0 mm.

The second extraction portion 342 is provided at one end of the second opposing electrode portion 341. When the lens 110 is formed, the second extraction portion 342 is provided in a position in the frame 120 that is near the bridge portion 122 or the temple portion 123.

The positions of the first extraction section 332 and the second extraction section 342 can be adjusted appropriately depending on the design of the lens 110 to be manufactured.

Furthermore, the first auxiliary electrode 33 is electrically connected to a terminal for applying voltage at the cross section in the thickness direction of the first auxiliary electrode 33.

For example, as shown in FIG. 3(a), 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 that overlaps the first extraction portion 332 in plan view, and a conductive portion 51 is formed within 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).

Furthermore, the second auxiliary electrode 34 is also electrically connected to a terminal for applying voltage in a cross section of the second auxiliary electrode in the thickness direction. More specifically, a through hole 40b exposing the second extraction portion 342 is similarly formed in the sealing portion 40 at a position overlapping the second extraction portion 342 in plan view, and a conductive portion 52 is formed within the through hole 40b. The second extraction portion 342 is used as a connection point with the conductive portion 52. The formed conductive portion 52 is electrically connected to the second extraction portion 342 (second auxiliary electrode 34).

Alternatively, as shown in FIG. 3(b), from the viewpoint of making the colored area AR larger, after the EC sheet 150 is processed into the lens 110, conductive portions 51 and 52 may be formed on the side surfaces of the lens 110. The formed conductive portions 51 and 52 are electrically connected to the first auxiliary electrode 33 and the second auxiliary electrode 34, respectively.

In FIG. 3(b), the connection between the conductive portion 52 and the second auxiliary electrode 34 is illustrated as a straight line, forming a substantially flat surface. However, the connection between the conductive portion 52 and the second auxiliary electrode 34 may have an uneven shape. That is, the uneven shape formed on the conductive portion 52 may interlock with the uneven shape formed on the second auxiliary electrode 34, thereby forming the connection. This ensures a wide contact area between the conductive portion 52 and the second auxiliary electrode 34 at the connection. As a result, the connection resistance of the connection can be reduced. Furthermore, in addition to the connection between the conductive portion 52 and the second auxiliary electrode 34, the connection between the conductive portion 52 and the second transparent electrode 32 and the connection between the conductive portion 52 and the sealing portion 40 may also have an uneven shape. This reduces the connection resistance of the connection and further increases the mechanical connection strength.

Like the connection between the conductive portion 52 and the second auxiliary electrode 34, the connection between the conductive portion 51 and the first auxiliary electrode 33 may have an uneven shape. That is, the aforementioned connection may be formed by the uneven shape formed on the conductive portion 51 interlocking with the uneven shape formed on the first auxiliary electrode 33. This ensures a wide contact area between the conductive portion 51 and the first auxiliary electrode 33 at the connection. As a result, the connection resistance of the connection can be reduced. Furthermore, in addition to the connection between the conductive portion 51 and the first auxiliary electrode 33, the connection between the conductive portion 51 and the first transparent electrode 31 and the connection between the conductive portion 51 and the sealing portion 40 also have an uneven shape. This reduces the connection resistance of the connection and further increases the mechanical connection strength.

In addition, at the connection portion between the conductive portion 52 and the second auxiliary electrode 34, the second transparent electrode 32, or the sealing portion 40, the uneven shape may be set only at the connection portion with the second auxiliary electrode 34, or at least at the connection portion with the second auxiliary electrode 34, or the uneven shape may be set in all layers.

Furthermore, if an uneven shape is set in all layers, the mechanical connection strength between the conductive portion 52 and each layer can be particularly increased, and the processing efficiency of the uneven shape can be further improved. Specifically, a process sequence can be adopted in which, after all layers are stacked, grooves are formed on the side of the laminate, and then the conductive portion 52 is formed to fill in the grooves. This allows the uneven shape to be processed more efficiently.

Similarly, at the connection between the conductive portion 51 and the first auxiliary electrode 33, the first transparent electrode 31, or the sealing portion 40, the uneven shape may be set only at the connection with the first auxiliary electrode 33, or at least at the connection with the first auxiliary electrode 33, or the uneven shape may be set in all layers.

Furthermore, if an uneven shape is set in all layers, the mechanical connection strength between the conductive portion 51 and each layer can be particularly increased, and the processing efficiency of the uneven shape can be further improved. Specifically, a process sequence can be adopted in which, after all layers are stacked, grooves are formed on the side of the laminate, and then the conductive portion 51 is formed to fill in the grooves. This allows the uneven shape to be processed more efficiently.

The electrical resistance of the first auxiliary electrode 33 is lower than the electrical resistance of the first transparent electrode 31. Similarly, the electrical resistance of the second auxiliary electrode 34 is lower than the electrical resistance of the second transparent electrode 32. The first auxiliary electrode 33 and the second auxiliary electrode 34 may contain a sintered body of metal particles. Examples of metal particles include particles of gold, silver, copper, aluminum, platinum, palladium, nickel, and tungsten. As the metal particles, one of these may be used, or two or more may be used in combination. Among these, silver particles or copper particles are preferred as the metal particles.

In order to further increase the efficiency of light sintering, the metal particles may contain a light absorbing material, such as indium oxide, tungsten oxide, or LaB6, which is an infrared absorbing particle.
The size of the metal particles is preferably an average particle diameter of 2 nm to 500 nm, more preferably 2 nm to 100 nm. By having the size of the metal particles within the above numerical range, sintering can be performed at a lower temperature. Note that particles of different sizes may be mixed and used as the metal particles.

In this specification, unless otherwise specified, "average particle size" means the particle size at 50% cumulative concentration (D50) of particles when the particle size distribution of particles is measured on a volume basis using a laser diffraction particle size distribution measurement method.

The first auxiliary electrode 33 and the second auxiliary electrode 34 can be formed, for example, by printing using ink containing metal particles. More specifically, they can be formed by ejecting and coating droplets of ink containing metal nanoparticles, and then sintering the metal particles.

As a coating method, inkjet or screen printing is preferred, as this provides better patterning accuracy.

The sintering method is not particularly limited as long as it can produce a sintered body of metal particles, and examples thereof include local heating methods such as plasma treatment, dielectric heating treatment, excimer light irradiation treatment, flash lamp light irradiation treatment, ultraviolet treatment, microwave treatment, infrared heater treatment, and hot air heater treatment.
Among these, it is preferable to sinter the metal particles by irradiating them with a laser. When irradiating the metal particles with a laser, it is possible to selectively heat only the metal particles by selecting a laser wavelength that is not absorbed by the resin substrate. Therefore, it is possible to further suppress thermal deformation of the resin substrate. Specifically, the wavelength of the laser is preferably an infrared wavelength or a visible light wavelength.

The electrochromic sheet of this embodiment has a thermal expansion suppression layer provided on the resin substrate, which suppresses deformation of the auxiliary electrode even when heated and fired at temperatures that tend to thermally expand the resin substrate, making peeling and cracking less likely to occur. Furthermore, even when the electrochromic sheet is heated and processed, deformation of the auxiliary electrode due to thermal expansion of the resin substrate is suppressed, making peeling and cracking less likely to occur. These factors make it possible to obtain an auxiliary electrode that is less likely to have high electrical resistance.

It is preferable that either or both of the first auxiliary electrode 33 and the second auxiliary electrode 34 further contain an organic π-conjugated ligand, and it is more preferable that both the first auxiliary electrode 33 and the second auxiliary electrode 34 further contain an organic π-conjugated ligand. By containing an organic π-conjugated ligand, the organic π-conjugated ligand forms a π-bond with the metal particle, and high conductivity is achieved due to the strong π-bond and the close proximity between the particles. Here, π-bonding refers to the parallel bonding of the π-conjugated plane of the π-conjugated molecule to the surface of the metal particle, and is a strong interaction between the organic π-orbital and the metal particle orbital that occurs when the organic π-orbital approaches the metal particle surface. Furthermore, an organic π-conjugated ligand is an organic ligand that acts on the metal particle through such a π-bond.

The organic π-conjugated ligand preferably has at least one substituent selected from the group consisting of an amino group, a mercapto group, a hydroxy group, a carboxy group, a phosphine group, a phosphonic acid group, a halogen group, an ammonium group, a sulfide group, and a selenoether group, which is coordinated to the surface of the metal particle.

When the ink containing the above-mentioned metal particles contains an organic π-conjugated ligand, it is preferable that the organic π-conjugated ligand has at least one substituent selected from the group consisting of a hydroxy group, a carboxy group, an amino group, an alkylamino group, an amide group, an imide group, a phosphonic acid group, a sulfonic acid group, a cyano group, a nitro group, and salts thereof, which is a substituent that makes the metal particles soluble in aqueous solvents and alcoholic solvents.
In addition, one or both of the first auxiliary electrode 33 and the second auxiliary electrode 34 preferably contains a binder resin to enhance adhesion to the formation surface (base). Examples of such materials include polyester and polyacrylic. The amount of binder resin added is preferably 5 mass % or less of the total amount of the auxiliary electrodes.

It is preferable that either or both of the first auxiliary electrode 33 and the second auxiliary electrode 34 have voids, and it is more preferable that both the first auxiliary electrode 33 and the second auxiliary electrode 34 have voids. Auxiliary electrodes made of sintered metal particles have voids due to the particle contact surfaces. The voids can be confirmed by SEM observation, and auxiliary electrodes in which voids of 5 μm or less can be confirmed by SEM observation are preferred.

In the electrochromic sheet of this embodiment, the auxiliary electrode has voids, which makes it easier for the auxiliary electrode to deform, making it less likely for the sintered body to peel or crack during heating and bending.

The average thickness of the first auxiliary electrode 33 and the second auxiliary electrode 34 is preferably 4 μm or less, more preferably 3 μm or less, and even more preferably 2 μm or less, independently of one another. More specifically, in a cross section of the first opposing electrode portion 331 and the second opposing electrode portion 341 that is 150 μm wide from the end of the first opposing electrode portion 331 and the second opposing electrode portion 341 on the colored region AR side in the short direction, the average thickness of the first auxiliary electrode and the second auxiliary electrode is preferably 4 μm or less, more preferably 3 μm or less, and even more preferably 2 μm or less.
The lower limit is not particularly limited, but examples include 0.01 μm or more, 0.1 μm or more, and 0.5 μm or more. More specifically, as shown in FIG. 3( b), when the conductive portions 51 and 52 are formed on the lens side surfaces, the average thickness of the first auxiliary electrode 33 and the second auxiliary electrode 34 is preferably 0.5 μm or more. An average thickness of 0.5 μm or more allows for more stable electrical connection and makes it more difficult for contact resistance to increase. The upper and lower limits can be combined in any manner.

By ensuring that the average thicknesses of the first auxiliary electrode 33 and the second auxiliary electrode 34 are within the above numerical ranges, peeling or cracking of the sintered body is less likely to occur during heating and sintering of the auxiliary electrodes or during heating and bending of the EC sheet, and the electrical resistance of the first auxiliary electrode 33 and the second auxiliary electrode 34 is less likely to increase.

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

It is preferable that the difference between the total length of the first opposing electrode portion 331 and the total length of the second opposing electrode portion 341 is small, and that the difference between them is not more than twice the total length of each other. For example, the total length of the first opposing electrode portion 331 is preferably more than 50% and less than 200% of the total length of the second opposing electrode portion 341, and more preferably 55% to 175%. Furthermore, the total length of the first opposing electrode portion 331 is preferably 58% to 165% of the total length of the second opposing electrode portion 341, more preferably 61% to 155%, and even more preferably 65% to 145%. The upper and lower limits can be combined in any manner.

The electrochromic sheet of this embodiment may be plastically deformed, since this makes it less likely for the sintered body to peel or crack at the auxiliary electrode. More specifically, the EC sheet may be partially or entirely plastically deformed during the heat bending process. The shape of the plastically deformed laminate may be convex, concave, or 3D curved.

(First electrode protective layer, second electrode protective layer)
The electrochromic sheet of this embodiment may further include either or both of a first electrode protective layer 36 and a second electrode protective layer 37. More specifically, the first electrode protective layer 36 is formed in contact with the first auxiliary electrode 33. The first auxiliary electrode 33 is sandwiched between the first transparent electrode 31 and the first electrode protective layer 36. The second electrode protective layer 37 is formed in contact with the second auxiliary electrode 34. The second auxiliary electrode 34 is sandwiched between the second transparent electrode 32 and the second electrode protective layer 37.

The first electrode protective layer 36, like the first auxiliary electrode 33, is arranged around the colored region AR on the periphery of the first transparent electrode 31 and is in contact with the first auxiliary electrode 33. The second electrode protective layer 37, like the second auxiliary electrode 34, is arranged around the colored region AR on the periphery of the second transparent electrode 32 and is in contact with the second auxiliary electrode 34. If the first electrode protective layer 36 and the second electrode protective layer 37 are conductive and transparent, the first electrode protective layer 36 and the second electrode protective layer 37 can also be formed in the colored region AR.

The first electrode protection layer 36 may or may not have a protruding portion at a position overlapping the above-mentioned first extraction portion 332, similar to the first extraction portion 332. Similarly, the second electrode protection layer 37 may or may not have a protruding portion at a position overlapping the above-mentioned second extraction portion 342, similar to the second extraction portion 342.

By forming the first electrode protective layer 36 and the second electrode protective layer 37, the auxiliary electrode can be more easily protected from oxygen, water, and the oxidation-reduction reaction of the EC layer 35. In addition, by forming the first electrode protective layer 36 and the second electrode protective layer 37, the electrical resistance of the auxiliary electrode can be further reduced.

Materials that are dense, have high barrier properties against oxygen and water, and are resistant to oxidation-reduction reactions can be used as materials for the first electrode protective layer 36 and the second electrode protective layer 37. Specific examples include inorganic oxides (silicon oxide, zirconia oxide, aluminum oxide, tin oxide, indium oxide, etc.), inorganic nitrides (silicon nitride, aluminum nitride, etc.), inorganic borides (aluminum boride, etc.), metals (Au, Pt, etc.), and carbon. These materials may be used alone or in combination.
In particular, when the first electrode protective layer 36 and the second electrode protective layer 37 are conductive and transparent, it is preferable that either or both of the first electrode protective layer 36 and the second electrode protective layer ₃₇ contain indium oxide. As the indium oxide, ITO, IZO, ITO, or _In2O3 is more preferable, and ITO is even more preferable.

The thicknesses of the first electrode protective layer 36 and the second electrode protective layer 37 are adjusted to protect the auxiliary electrode 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 electrode protective layer 36 and the second electrode protective layer 37, the average thicknesses of the first electrode protective layer 36 and the second electrode protective layer 37 are, for example, independently set to 10 nm or more and 200 nm or less, preferably 20 nm or more and 100 nm or less.

(Electrochromic Layer)
As shown in Figures 2 and 3, the EC layer 35 is formed in a three-layer structure having, for example, 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.
Alternatively, the EC layer 35 may be formed as a single layer in which the material of the first EC layer 351 , the material of the second EC layer 352 , and the material of the electrolyte layer 353 are mixed.

(First Electrochromic Layer)
The first EC layer 351 is a color-changing layer and contains, as a main material, a material that changes color from a transparent state upon oxidation. Examples of materials that change color upon 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.
The first EC layer 351 may be a polymerized polymer film or a film made of a monomolecular material. The first EC layer 351 may also have a supported particle (so-called Grätzel) structure in which an electrochromic material is adsorbed onto the surfaces of semiconductor particles or conductive particles such as titanium oxide particles and tin oxide particles.

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

As a material that is colored by an oxidation reaction, one of these may be used, or two or more may be used in combination.

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.
When the average thickness of the first EC layer 351 is equal to or greater than the lower limit, the color density can be increased. That is, the transmittance change can be increased. Furthermore, when the average thickness is equal to or less than the upper limit, the film quality of the first EC layer 351 can be made more uniform, and the manufacturing cost can be reduced.

(Second Electrochromic Layer)
The second EC layer 352 is a color-changing layer and contains, as a main material, a material that changes color from a transparent state upon reduction reaction. Examples of the material that changes color upon 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.
The second EC layer 352 may be a polymerized polymer film or a film made of a monomolecular material. The second EC layer 352 may also have a supported particle (so-called Grätzel) structure in which an electrochromic material is adsorbed onto the surfaces of semiconductor particles or conductive particles such as titanium oxide particles and tin oxide particles.

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

The color (color 1) that the first EC layer 351 is colored to by an oxidation reaction and the color (color 2) that the second EC layer 352 is colored to by a reduction reaction may be the same color tone or different color tones. When color 1 and color 2 are the same color tone, the color density can be increased and the contrast can be further improved. When color 1 and color 2 are different color tones, the color that the EC element 30 emits will be the color obtained by mixing color 1 and color 2.

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

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 equal to or greater than the above-mentioned lower limit, it is easier to increase the color density. In other words, it is easier to increase the change in transmittance. When the average thickness of the second EC layer 352 is equal to or less than the above-mentioned upper limit, the decrease in visibility due to coloring is further suppressed, and manufacturing costs can be further reduced.

(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.

Examples of the electrolyte 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. Examples of the counter ion (anion) of the electrolyte include halogen, thiocyanate ion (SCN ⁻ ), chlorate ion (ClO ₃ ⁻ ), perchlorate ion (ClO ₄ ⁻ ), tetrafluoroborate ion (BF ₄ ⁻ ), hexafluorophosphate ion (PF ₆ ⁻ ), trifluoromethanesulfonate ion (CF ₃ SO ₃ ⁻ ), trifluoroacetate ion (CF ₃ COO ⁻ ), and bisfluorosulfonium imide (N(SO ₂ F) ₂ ⁻ ).

Specific examples of such electrolytes include LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ COO, KCl, NaClO ₃ , NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg(ClO ₄ ) ₂ , Mg(BF ₄ ) ₂ , etc. As the electrolyte, one of these may be used, or two or more of them may be used in combination.
When the electrolyte is solid, it is used as an electrolyte solution dissolved in a solvent, or as a solid electrolyte membrane to which a high molecular weight polymer or a gelling agent is further added.

On the other hand, if the electrolyte is a liquid ionic liquid, it can be used as is as the electrolyte layer 353. It may also be used as a solid electrolyte membrane. Among ionic liquids, organic ionic liquids have a molecular structure that allows them to remain liquid over a wide temperature range, including room temperature, making them easy to handle.

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.

[Sealing part]
The sealing portion 40 is sandwiched between the first substrate 21 and the second substrate 22 and defines a colored region AR between the first substrate 21 and the second substrate 22. The sealing portion 40 is made of a thermosetting resin or a photocurable resin that adheres to the surfaces of the first substrate 21 and the second substrate 22. Specifically, known materials such as acrylic resin, urethane resin, and epoxy resin can be used. Furthermore, the sealing portion 40 preferably contains an inorganic filler to further reduce linear thermal expansion and oxygen and water permeability. Examples of inorganic fillers include the same inorganic fillers as those used in the first thermal expansion suppression layer 24 and the second thermal expansion suppression layer 25. Furthermore, because high transparency is not required for the sealing portion 40, an opaque filler with a large average particle size, for example, 0.2 μm or greater, can also be used.

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.

<Laminates, eyeglass lenses>
FIG. 5 is an explanatory diagram illustrating a method for manufacturing a lens using the EC sheet 150.

First, as shown in FIG. 5(a), the EC sheet 150 is bent under heat to curve it to match the curvature of the desired lens. The bending is performed, for example, by press molding or vacuum forming.

Next, as shown in Figure 5(b), the curved EC sheet 150 is insert-molded as an insert item, 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 this invention. The lens material 119 is processed as described below to become the lens body 115.

Lens material 119 is transparent to visible light. The material of lens material 119 can be a thermoplastic resin known as a material for optical components.

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 21 or second substrate 22) 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, thereby suppressing light scattering and reflection at the interface between the EC sheet 150 and the lens material 119. 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.

The thickness of the lens material 119 is preferably, for example, 1.5 mm or more and 20 mm or less. By keeping 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.

Next, the surface of the lens material 119 is polished, and the surfaces of the EC sheet 150 and 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 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 within the through-holes.

3(a) can be formed by a conductive paste filled in the through-hole or a conductive cylindrical member inserted in the through-hole. Alternatively, any known material can be used as long as it is formed in the through-hole 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).
The conductive portions 51 and 52 in the form of FIG. 3B can be easily formed by applying a conductive paste to the side surface of the trimmed lens 110 (FIG. 5C).

Next, as shown in Figure 5(c), the laminate 160 is trimmed to a shape corresponding to the rim portion 121 of the sunglasses 100 described above. At this time, trimming around the first extraction portion 332 and the second extraction portion 342 is performed using, for example, a rotating cylindrical grindstone or milling.

By this 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 Figure 1). In Figure 5, when cutting the laminate 160, cutting is performed along the outer peripheries of the first auxiliary electrode 33 and second auxiliary electrode 34 of the EC sheet 150 to obtain the lens 110. The resulting lens 110 corresponds to the "eyeglass lens" of this invention.

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 that is the same shape as the first extraction portion 332 and the second extraction portion 342 in a plan view.

Note that if the first and second extraction portions 332 and 342 of the EC sheet 150 are configured so as not to protrude from the respective auxiliary electrodes toward the outer periphery, the protrusion 115a may be omitted from the lens body 115.

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 unit 111 are electrically connected to the frame 120 via 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.

Because it is easier to hide the first auxiliary electrode 33, the second auxiliary electrode 34, and the sealing portion 40 of the EC sheet 150, it is preferable that the eyeglasses (sunglasses 100) to which the lens 110 is applied have a framed design rather than a frameless design that does not have a frame surrounding the lens. For the same reason, it is preferable that the eyeglasses to which the lens 110 is applied have a design in which the entire lens is surrounded by a frame rather than a half-rim type design.

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, Fox, etc.

The laminate, eyeglass lens, and eyeglasses configured as described above have the electrochromic sheet, resulting in high-quality products that can develop and fade color without delay.

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

In addition, in this embodiment, the EC layer 35 has a first EC layer 351 and a second EC layer 352, but this is not limited to this. 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.

The above describes preferred embodiments of the present invention with reference to the accompanying drawings, but 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.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
[Example 1]
The EC sheet 150 of Example 1 was produced by the method described below.

1. Preparation of First Substrate 21 First, a polycarbonate sheet (trade name: PC2151, manufactured by Teijin Limited) having a thickness of 0.3 mm, a square shape with one side measuring 100 mm, and a glass transition temperature of 146° C. was prepared as the first resin substrate 23.

An acid-modified epoxy urethane acrylate oligomer resin (product name: ZCR6001H, manufactured by Nippon Kayaku Co., Ltd., softening temperature after curing: 198°C), which is a curable resin material, was prepared as the main material of the first thermal expansion suppression layer 24. In addition, an inorganic particle propylene glycol monomethyl ether dispersion (product name: PGM-AC2140Y, manufactured by Nissan Chemical Co., Ltd., methacrylic surface treatment, average particle size: 10 nm to 15 nm, SiO ₂ ) was prepared as the inorganic filler to be contained in the curable resin.

An inorganic filler was added to the curable resin so that the inorganic particle content was 150% by mass relative to the total amount of curable resin. Next, a photoinitiator (product name: Omnirad TPO H, manufactured by IGM Resins B.V.) was added in an amount of 4% by mass relative to the total amount of curable resin to prepare a coating solution.

The resulting coating liquid was diluted with 2-ethoxyethanol, and then the diluted coating liquid was applied to the surface of a polycarbonate sheet using a bar coater. The coating liquid was then dried at 80°C for 5 minutes, and then cured by UV irradiation to form a first thermal expansion suppression layer 24 with an average thickness of 2 μm.

Next, the first substrate 21, in which the first thermal expansion suppression layer 24 was formed on the first resin substrate 23, was cut into the sheet shape shown in Figure 2 (minor axis 55 mm, major axis 75 mm) to obtain the first substrate 21.

2. Preparation of Electrolyte Layer 353 First, binder resin 1, binder resin 2, and ionic liquid 1 described below were prepared.
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: 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIMFS) (Kanto Chemical Co., Ltd.)

Next, binder resin 1, binder resin 2, and ionic liquid 1 were mixed in a mass ratio of binder resin 1: binder resin 2: ionic liquid 1 = 18:7:75.

Furthermore, a photopolymerization initiator (product name: IRGACURE 184, manufactured by BASF Corporation) was mixed in at 0.5% by mass relative to the total amount of binder resin 1 and binder resin 2 to prepare an electrolyte solution.

The resulting electrolyte solution was applied to the surface of a release-treated PET film (product name: NP75C, manufactured by Panac Corporation). A release-treated PET film (NP75A, manufactured by Panac Corporation) was then placed on top of the PET film coated with the electrolyte solution. The resulting two PET films were cured by UV irradiation to produce an electrolyte sheet laminated with two PET films.

Next, the obtained electrolyte sheet was cut with a Pinnacle (registered trademark) blade into an electrolyte layer shape corresponding to Fig. 2 to obtain an electrolyte layer 353. The area of the electrolyte layer 353 corresponding to the colored region AR was 1250 ^mm2 .

3. Fabrication of First Transparent Electrode 31 On the obtained first substrate 21, a first transparent electrode 31 with an ITO thickness of 130 nm was obtained using a sputtering device (manufactured by Solaris Evatec Co., Ltd.).

4. Fabrication of First Auxiliary Electrode 33 Next, a water-based Ag nanoparticle ink containing an organic π-conjugated ligand (product name: Drycure Ag-JB 0420B, manufactured by C-INK) was prepared.
The aqueous Ag nanoparticle ink was inkjet coated (using a Precision Core i1600 head-mounted machine manufactured by Epson Corporation) to an average thickness of 2 μm, and then heated and baked in an oven at 120° C. for 30 minutes to form a first auxiliary electrode 33.

5. Preparation of First EC Layer 351 Polyethylene glycol diacrylate (trade name: PEG400DA, manufactured by Nippon Kayaku Co., Ltd.), a photoinitiator (trade name: IRGACURE 184, manufactured by BASF Corporation), a compound represented by the following formula (I) (compound I), and cyclohexanone were mixed in a mass ratio of polyethylene glycol diacrylate:photoinitiator:compound I:cyclohexanone = 76:3:170:860.

(wherein Me represents a methyl group)

The resulting mixed solution was inkjet coated onto the first transparent electrode 31 to form a coating film in the region corresponding to the first EC layer 351 shown in Figure 3(b). The coating film was then exposed to UV light in a nitrogen atmosphere to obtain the first EC layer 351 containing compound I. The average thickness of the first EC layer 351 was 1 μm.

6. Preparation of Second Substrate 22 The second substrate 22 was obtained in the same manner as in the first substrate 21.

7. Preparation of Second Transparent Electrode 32 The second transparent electrode 32 was obtained in the same manner as in the preparation of the first transparent electrode 31 .

8. Preparation of Second Auxiliary Electrode 34 The second auxiliary electrode 34 was obtained in the same manner as in the first auxiliary electrode 33 .

9. Preparation of second EC layer 352 5.50 g of a tin oxide sol solution (product name: Celnax CX-S510M, manufactured by Nissan Chemical Industries, Ltd.), 1.00 g of an ethanol solution containing 10% by mass of ethyl cellulose (viscosity: 10 mPa s), 0.50 g of tin(IV) tetra(t-butoxide), and 9.05 g of terpineol were mixed. Next, the mixture was subjected to ultrasonic treatment for 2 minutes using an ultrasonic homogenizer, and then the volatile components were removed using an evaporator to obtain a paste.

The resulting paste was screen-printed on the second transparent electrode 32 in an area corresponding to the second EC layer 352 in Figure 3(b) to an average thickness of 2 μm. The screen-printed paste was then dried at 80°C and subjected to UV ozone treatment at 90°C for 20 minutes to obtain a porous tin oxide particle film.

Next, a 2,2,3,3-tetrafluoropropanol solution containing 1.5% by mass of a compound represented by the following formula (II) (Compound II) was prepared.

The 2,2,3,3-tetrafluoropropanol solution was spin-coated onto the tin oxide particle film and annealed at 80°C for 10 minutes to obtain a second EC layer 352 in which Compound II was supported on the tin oxide particle film.

10. Fabrication of EC Sheet 150 The electrolyte layer 353 was bonded to the surface of the second EC layer 352. Next, a sealing material, which is an epoxy acrylate resin (product name: 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. Next, the electrolyte layer 353 bonded to the second EC layer was bonded to the surface of the first EC layer 351.

The obtained laminate was 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. Next, as pre-curing, the obtained laminate was irradiated with ultraviolet light (3 J/cm ² ). Next, as main curing, the pre-cured laminate was subjected to a thermal curing treatment at 100°C for 1 hour to form the sealing portion 40.
By the above operations, an EC sheet of Example 1 having the arrangement shown in FIG. 4 was obtained.

(EC sheet evaluation)
1. Evaluation of Appearance of Auxiliary Electrodes The first auxiliary electrode 33 and the second auxiliary electrode 34 of the EC sheet of Example 1 were observed under a microscope, and no peeling or cracks were found.

Next, the EC sheet of Example 1 was molded into a spherical shape as shown in Figure 5(a) under conditions of a mold curvature radius of 130 mm and a mold temperature of 146°C. Microscopic observation of the first auxiliary electrode 33 and second auxiliary electrode 34 of the EC sheet of Example 1 molded into a spherical shape revealed no peeling or cracks.

2. Evaluation of Electrode Resistance An EC lens sheet was produced to evaluate the electrical resistance.
First, the EC sheet of Example 1 was cut into a lens shape as shown in Fig. 5(c). Silver paste (product name: CN7120, manufactured by Kaken Tech Co., Ltd.) was applied to the side surfaces of the obtained EC lens sheet, and then cured and dried. That is, conductive portions 51 and 52 as shown in Fig. 3(b) were formed on the first auxiliary electrode 33 and the second auxiliary electrode 34, respectively, to obtain the EC lens sheet of Example 1.

The contact resistance of the EC lens sheet of Example 1 was measured using the AC impedance method described below, and the contact resistance was determined from the point where Z'' on the Nyquist diagram was 0. As a result, as shown in Figures 6(a) and 6(b), the contact resistance was 30 Ω.

The measurement conditions for the AC impedance method are as follows:
Measurement device: modulab XM (manufactured by Solartron Analytical)
Applied voltage: 0 V
Amplitude: 10mV
Response frequency: 0.1Hz to 1MHz
Measurement temperature: 25℃

3. Evaluation of light control operation A power source was connected to the conductive portions 51 and 52 of the EC lens sheet of Example 1, and a positive voltage of 2 V was applied to the conductive portion 51. As a result, the colored area AR changed from transparent to blue. Next, the conductive portions 51 and 52 were short-circuited, and the blue color of the colored area AR disappeared. These results confirmed that the EC sheet of Example 1 has a light control function.

[Example 2]
(Production of EC sheet)
An EC sheet of Example 2 was obtained in the same manner as in the EC sheet of Example 1, except that the inkjet-coated auxiliary electrode was dried at 95°C for 30 minutes and then photo-baked with an infrared laser.
The laser light source was CW light, wavelength 940 nm, 360 W, irradiation spot size: 80 mm × 2 mm (laser light source L13920-711 manufactured by Hamamatsu Photonics K.K.,
An irradiation unit A133933-13W (manufactured by Hamamatsu Photonics KK) was used, and the scanning speed was set to 150 mm/sec.

(EC sheet evaluation)
1. Evaluation of Appearance of Auxiliary Electrodes The first auxiliary electrode 33 and the second auxiliary electrode 34 of the EC sheet of Example 2 were observed under a microscope, and no peeling or cracks were found.

Next, the EC sheet of Example 2 was molded into a spherical shape in the same manner as the EC sheet of Example 1. Microscopic observation of the first auxiliary electrode 33 and second auxiliary electrode 34 of the EC sheet of Example 1 molded into a spherical shape revealed no peeling or cracks.

2. Evaluation of Electrode Resistance Using the EC sheet of Example 1, an EC lens sheet of Example 2 was produced in the same manner as in Example 1.
Using the obtained EC lens sheet of Example 2, the contact resistance was determined in the same manner as in Example 1. As a result, the contact resistance was 30 Ω.

3. Evaluation of Light Controlling Operation The light control operation was evaluated using the EC lens sheet of Example 2 in the same manner as in Example 1. As a result, it was confirmed that the EC sheet of Example 2 had a light control function.
[Comparative Example 1]
(Production of EC sheet)
The EC sheet of Comparative Example 1 was produced in the same manner as the EC sheet of Example 1, except that the first thermal expansion suppression layer 24 and the second thermal expansion layer 25 were not formed, and the first auxiliary electrode 33 and the second auxiliary electrode 34 were formed by sputtering using a silver alloy (APC, manufactured by Furuya Metal Co., Ltd.). The silver alloy film had a thickness of 200 nm and was patterned using mask sputtering (manufactured by Solaris Evatec Co., Ltd.).

(EC sheet evaluation)
1. Evaluation of Appearance of Auxiliary Electrodes When the first auxiliary electrode 33 and the second auxiliary electrode 34 of the EC sheet of Comparative Example 1 were observed under a microscope, no peeling or cracks were found.

Next, the EC sheet of Comparative Example 1 was molded into a spherical shape in the same manner as the EC sheet of Example 1. Microscopic observation of the first auxiliary electrode 33 and second auxiliary electrode 34 of the EC sheet of Comparative Example 1 molded into a spherical shape revealed cracks.

2. Evaluation of Electrode Resistance Using the EC sheet of Comparative Example 1, an EC lens sheet of Comparative Example 1 was produced in the same manner as in Example 1.
The contact resistance was measured using the obtained EC lens sheet of Comparative Example 1 in the same manner as in Example 1, but the contact resistance was so large that normal measurement results could not be obtained.

3. Evaluation of Light Controlling Operation The light control operation was evaluated using the EC lens sheet of Comparative Example 1 in the same manner as in Example 1. As a result, it was confirmed that the electrochromic layer did not react and had no light control function.

21...first substrate, 22...second substrate, 23...first resin substrate, 24...first thermal expansion suppression layer, 25...second thermal expansion suppression layer, 26...second resin 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), 36...first electrode protection layer, 37...second electrode protection layer, 40...sealing portion, 40a, 40b...through hole, 51, 52...conductive portion, 100...sunglasses, 110...lens, 111...electrochromic portion (EC portion), 11 5...lens body, 115a...protrusion, 119...lens material, 120...frame, 121...rim portion, 122...bridge portion, 123...temple portion, 124...nose pad portion, 125...switch, 126...battery, 150...electrochromic sheet (EC sheet), 160...laminated body, 331...first opposing electrode portion, 332...first lead-out portion, 341...second opposing electrode portion, 342...second lead-out portion, 351...first electrochromic layer (first EC layer), 352...second electrochromic layer (second EC layer), 353...electrolyte layer, AR...colored region

Claims (15)

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 first substrate includes a first resin substrate and a first thermal expansion suppression layer provided on the first resin substrate;
The electrochromic element includes a first transparent electrode provided on the first thermal expansion suppressing layer side of the first substrate;
a first auxiliary electrode disposed around the colored region, electrically connected to the first transparent electrode, and including a sintered body of metal particles;
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 changes color upon application of a voltage;
Electrochromic sheet. the second substrate further includes a second resin substrate and a second thermal expansion suppression layer provided on the second resin substrate,
The electrochromic element further includes a second auxiliary electrode disposed around the colored region, electrically connected to the second transparent electrode, and including the sintered body.
The electrochromic sheet according to claim 1 . Further, the semiconductor device has either one or both of a first electrode protection layer and a second electrode protection layer,
the first electrode protection layer is in contact with the first auxiliary electrode,
the first auxiliary electrode is sandwiched between the first transparent electrode and the first electrode protection layer,
the second electrode protection layer is in contact with the second auxiliary electrode,
The electrochromic sheet according to claim 2 , wherein the second auxiliary electrode is sandwiched between the second transparent electrode and the second electrode protection layer. the first auxiliary electrode has a first opposing electrode portion extending along a part of the outer periphery of the colored region,
the second auxiliary electrode has a second opposing electrode portion extending along another part of the outer periphery of the colored region,
the second opposing electrode portion is on the opposite side of the colored region from the first opposing electrode portion and faces the first opposing electrode portion;
3. The electrochromic sheet according to claim 2, wherein a width of a portion including at least one end of the first opposing electrode portion and the second opposing electrode portion is 0.1 mm or more and 2.0 mm or less. The electrochromic sheet of claim 4, wherein the average thickness of the first auxiliary electrode and the second auxiliary electrode is 4 μm or less in a cross section of the first opposing electrode portion and the second opposing electrode portion that is 150 μm wide from the end of the colored region in the short direction. The electrochromic sheet according to claim 2, wherein either or both of the first thermal expansion suppression layer and the second thermal expansion suppression layer are made of a curable resin containing a filler. The electrochromic sheet according to claim 2, wherein either or both of the first auxiliary electrode and the second auxiliary electrode further contain an organic π-conjugated ligand. The electrochromic sheet according to claim 2, wherein either or both of the first auxiliary electrode and the second auxiliary electrode have a gap. one or both of the first resin substrate and the second resin substrate contains a thermoplastic resin;
3. The electrochromic sheet according to claim 2, wherein the glass transition temperature of the thermoplastic resin is 200° C. or lower. The electrochromic sheet of claim 2, further comprising: the first auxiliary electrode and the second auxiliary electrode, in a cross section in the thickness direction of the first auxiliary electrode and the second auxiliary electrode, each independently electrically connected to a terminal for applying a voltage. The electrochromic sheet according to claim 1 or 2, wherein either or both of the first transparent electrode and the second transparent electrode contain indium oxide. The electrochromic sheet according to claim 1 or 2, which has been plastically deformed. The electrochromic sheet according to claim 1 or 2;
and a lens material on which the electrochromic sheet is laminated. an electrochromic section obtained by cutting the electrochromic sheet according to claim 2 along the outer peripheries of the first auxiliary electrode and the second auxiliary electrode;
and a lens body on which the electrochromic portion is laminated. The eyeglass lens according to claim 14;
a frame for holding the eyeglass lenses;
The lens body is electrically connected to the frame of the eyeglasses.