JP2016045242A - Electrolytic solution composition, and optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic solution composition that can be driven with low voltage in a low temperature atmosphere and which, with low coloring, can transmit light during permeation, and an optical device using this electrolyte composition.SOLUTION: The electrolytic solution composition has the first metal compound of an Ag salt, etc., containing a first metal, a second metal compound of a Cu salt, etc., having a decoloring function for the first metal, and a support electrolyte such as Br, etc., that are dissolved in a solvent. The coagulation point of this electrolytic solution composition is -20°C or lower, and the solvent contains at least one kind of specific solvent, by 60wt% or more, comprising an organic compound having a sulfinyl group (for example, tetramethylene sulfoxide, and methyl(methylsulfinyl)methyl sulfide). In the optical device, the electrolytic solution 7 of an electrolyte layer 3 is formed with the electrolytic solution composition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrolytic solution composition and an optical device, and more specifically, an electrolytic solution composition containing an electrochromic material, and using this electrolytic solution composition, allows incident light to be switched between a reflection mode and a transmission mode. The present invention relates to a configured optical device.

  2. Description of the Related Art In recent years, research and development have been actively conducted on optical devices that use an electrochromic material that generates a redox reaction upon application of a DC voltage and that can switch incident light between a reflection mode and a transmission mode.

  For example, Patent Document 1 includes a pair of substrates, a pair of electrodes formed on opposing surfaces of the pair of substrates, and an electrochromic material and a mediator containing silver that are sandwiched between the pair of electrodes. A display device having an electrolyte layer has been proposed.

  In Patent Document 1, an electrochromic material such as an Ag salt, a mediator such as a Cu salt, and a supporting electrolyte such as a Br salt are dissolved in a solvent such as dimethyl sulfoxide (hereinafter referred to as “DMSO”) to prepare an electrolytic solution composition. Produced and composed of an electrolyte layer with this electrolyte composition, realized a reflective state having a very high reflectivity by applying a voltage of -2.5 V, and realized a transmissive state by releasing the voltage application. Trying to get a good repeatability.

  Further, in Patent Document 2, an electrolytic solution composed of a solution in which a silver salt is dissolved is disposed between a working electrode and a counter electrode, and silver is precipitated or dissolved by driving control of these electrodes, thereby coloring Alternatively, in the optical apparatus using a mixed solvent composed of DMSO and another solvent as a solvent for dissolving the silver salt, the other solvent in the mixed solvent is propylene carbonate. , Acetonitrile, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N-methylpropionamide, N-methylpyrrolidone, 2-ethoxyethanol, 2-methoxyethanol, 1,3 -Dioxolane, ethyl acetate, tetrahydrofuran, methyltetrahydrofuran, dimethoxyethane, diethoxyethane There has been proposed an optical apparatus that is a solvent selected from the group consisting of tan and γ-butyrolactone, in which the proportion of dimethyl sulfoxide in the mixed solvent is larger than the proportion of the other solvents described above.

  In Patent Document 2, a mixed solvent having a DMSO content of 50% to 60% by volume is used, and an Ag salt is used for the electrochromic material, and the Ag salt is dissolved in the mixed solvent. Accordingly, an optical device that can be stored even at a low temperature of −20 ° C. is obtained.

  Further, Patent Document 3 is configured such that a solution of Ag salt is disposed between the counter electrodes, and Ag is precipitated or dissolved by driving control of these electrodes, so that the silver is co-deposited with the dissimilar metal. An optical device is proposed.

In Patent Document 3, an Ag salt such as AgBr and CuBr ₂ as a source of eutectoid metal are dissolved in a solvent such as dimethylformamide or DMSO, and a clarifying agent (reducing agent) such as triethanolamine is used. Then, the dissolved Cu salt, that is, divalent Cu ions (colored) is reduced to monovalent Cu ions (colorless) to be colorless and transparent, thereby obtaining an optical device that can be driven at a low voltage at a low temperature. .

JP 2012-181389 A (Claims 1, 7, 8, paragraph numbers [0021] to [0034] etc.) Japanese Patent No. 3915850 (Claims 1, 3, Table 1, etc.) JP-A-9-297324 (Claim 1, paragraph numbers [0024], [0080] to [0090], etc.)

  However, in Patent Document 1, although DMSO is used as a solvent to enable driving at a low voltage of −2.5 V, this DMSO has a high freezing point of + 18 ° C. and can be driven at a low voltage at room temperature. Even in such a case, driving in a low temperature atmosphere is difficult.

  Further, in Patent Document 2, a solvent having a low freezing point, which is limitedly listed, is mixed with DMSO, and by using such a mixed solvent, it can be stored at a low temperature of −20 ° C., and can be driven in a low temperature atmosphere. Yes.

  However, when this mixed solvent is applied to the display device of Patent Document 1, the electrolytic solution exhibits a very strong initial coloration due to the interaction between the divalent Cu ions and the solvent. The incident light cannot be transmitted.

  That is, when the solvent is formed of only DMSO as in Patent Document 1, the color of Ag is erased by the neutralization of divalent Cu ions by releasing the voltage application and allowing it to stand naturally. Further, the electrolytic solution is substantially colorless and low-colored, and incident light is transmitted through the electrolytic solution. However, when a mixed solvent with the solvent listed in Patent Document 2 is used as the electrolyte solvent so that it can be driven at a low temperature, it is caused by the interaction between the divalent Cu ion and the solvent as described above. Exhibits very strong initial coloration. Therefore, the mixed solvent described in Patent Document 2 cannot be used for applications in which the electrolytic solution is required to be substantially colorless when transmitted, for example, for changing the light amount of a window.

  In Patent Document 3, the electrolyte solution contains a clearing agent in the electrolyte solution so that the electrolyte solution is colorless during transmission. However, the divalent Cu ions that are colored through the clearing agent are monovalent. Since it is made colorless by reducing to Cu ions, it is impossible to obtain repeated characteristics.

  The present invention has been made in view of such circumstances, and an electrolytic solution composition that can be driven at a low voltage in a low-temperature atmosphere and can transmit light with low coloration when transmitted, and the electrolysis An object of the present invention is to provide an optical device using the liquid composition.

  As described above, when a divalent Cu salt is added, it exists as a divalent Cu ion in the electrolytic solution, and has a function of decoloring the color of Ag when the voltage application is released and left to stand naturally. Therefore, in order to transmit light with low coloration, it is necessary to contain a metal compound having this type of decoloring function in the solvent.

  On the other hand, in consideration of various environmental conditions, in order to be able to drive at a low voltage in a sufficiently low temperature atmosphere, it is necessary to ensure driving at least at −20 ° C. or lower.

  However, DMSO used in Patent Document 1 has a high freezing point of + 18 ° C. and is difficult to drive in a low temperature atmosphere.

  Therefore, the present inventor pays attention to the sulfinyl group (—S (═O) —) as a characteristic group contained in DMSO, and uses an organic compound having a sulfinyl group and an organic compound having no sulfinyl group. In addition, when intensive studies were conducted by adjusting the composition of the electrolytic solution so that the freezing point was −20 ° C. or lower, the content of the organic compound having a sulfinyl group was set to 60 wt% or more in the electrolytic solution, Even in a low-temperature atmosphere of 20 ° C. or lower, an electrochromic material can be caused to undergo an oxidation-reduction reaction by applying a low voltage. Further, even when a metal compound having a decoloring function for the electrochromic material is contained in the electrolytic solution, It was found that the electrolyte solution can be substantially colorless and low-colored during permeation.

  The present invention has been made on the basis of such knowledge, and the electrolytic solution composition according to the present invention is decolored with respect to the first metal compound containing at least the first metal and the first metal. An electrolytic solution composition in which a second metal compound having a function and a supporting electrolyte are dissolved in a solvent, the freezing point is −20 ° C. or lower, and the solvent is composed of an organic compound having a sulfinyl group. It is characterized by containing at least 60 wt% of at least one specific solvent.

  In the electrolyte composition of the present invention, the organic compound is at least one of tetramethylene sulfoxide (hereinafter referred to as “TMSO”) and methyl (methylsulfinyl) methyl sulfide (hereinafter referred to as “FAMSO”). It is preferable to include one of them.

  TMSO and FAMSO have a very low freezing point, and the freezing point of the electrolyte composition can be easily set to -20 ° C or lower. And since it has a sulfinyl group in an organic compound, it becomes possible to implement | achieve low coloring easily combined with the effect | action of a 2nd metal compound.

  In the electrolyte composition of the present invention, the organic compound preferably contains DMSO in addition to TMSO and / or FAMSO.

  As a result, low coloring can be realized in a low temperature atmosphere, and driving at a much lower voltage is possible.

  In the electrolytic solution composition of the present invention, the solvent preferably contains any one or more of a lactone compound, a carbonate compound, and a nitrile compound.

  Accordingly, it is possible to drive at a low voltage in a low-temperature atmosphere, and it is possible to obtain an electrolytic solution composition that can transmit incident light with low coloration during transmission and has excellent voltage resistance.

  In the electrolytic solution composition of the present invention, it is preferable that the first metal compound contains an Ag compound.

  As a result, in the electrolytic solution composition, the Ag compound is reduced by an oxidation-reduction reaction caused by voltage application, and Ag is deposited.

  In the electrolytic solution composition of the present invention, the second metal compound preferably contains a Cu compound.

  As a result, when the electrolyte composition is subjected to a reverse polarity voltage (hereinafter referred to as “reverse voltage”) by reversing the polarity of the voltage from that of natural standing or metal deposition, Cu is decoloring function. To achieve the desired low coloration.

  Furthermore, in the electrolytic solution composition of the present invention, the supporting electrolyte preferably contains a halogen compound.

  The optical device according to the present invention is an optical device in which an electrolyte layer is interposed between a pair of transparent electrodes, and the electrolyte layer is formed of any one of the above-described electrolyte compositions. It is a feature.

  According to the electrolytic solution composition of the present invention, the first metal compound containing at least the first metal, the second metal compound having a decoloring function with respect to the first metal, and the supporting electrolyte are dissolved in the solvent. Since the solidification point is −20 ° C. or lower and the solvent contains 60 wt% or more of at least one specific solvent composed of an organic compound having a sulfinyl group, the electrolytic solution composition is −20 Even in a low-temperature atmosphere of less than or equal to 0 ° C., the first metal is deposited by applying a low voltage, and the first metal possessed by the second metal compound has a decoloring function for the first metal, so The metal dissolves in the solvent. As a result, a low-colored electrolytic solution composition having good permeability can be obtained without causing initial coloration due to the interaction between the second metal contained in the second metal compound and the solvent. Can do.

  Moreover, according to the optical device of the present invention, an electrolyte layer is interposed between a pair of transparent electrodes, and the electrolyte layer contains any one of the above electrolyte compositions. By applying a low-voltage atmosphere and a low voltage, the first metal is deposited on the surface of one transparent electrode to realize a reflective mode having a good reflectivity. A low-color transmission mode with good transparency can be realized. In addition, by repeating the low voltage application and the natural standing or the reverse voltage application in the electrolytic solution composition, the oxidation-reduction reaction is repeated in the electrolytic solution, so that an optical device with good repeated durability can be obtained.

It is sectional drawing which shows one Embodiment of the optical apparatus using the electrolyte solution composition which concerns on this invention. It is a figure which shows the principle of operation of the said optical apparatus, (a) has shown the reflection mode, (b) has shown the transmissive mode.

  Next, an embodiment of the present invention will be described in detail.

  FIG. 1 is a cross-sectional view schematically showing one embodiment of an optical device manufactured using the electrolytic solution composition according to the present invention.

  In this optical device, a first transparent electrode 2 is formed on the surface of a first transparent substrate 1 such as a glass substrate, and an electrolyte layer 3 is formed on the surface of the first transparent electrode 2. A second transparent electrode 4 is formed on the surface of the electrolyte layer 3, and a second transparent electrode made of the same glass substrate as the first transparent substrate 1 is formed on the surface of the second transparent electrode 4. A substrate 5 is formed.

Here, the 1st and 2nd transparent electrodes 2 and 4 are formed with the transparent conductive film. The transparent conductive film is not particularly limited as long as it has good transparency and conductivity. For example, ITO (tin doped indium oxide), ZnO, TNO (niobium doped titanium oxide), GZO (gallium doped) Zinc oxide), In ₂ O ₃ —ZnO-based materials, or the like can be used.

  The electrolyte layer 3 includes a spacer 8 that secures an interval between the first transparent electrode 2 and the second transparent electrode 4, a protective wall 6 formed on the inner peripheral surface of the spacer 8, and a protective wall 6 within the protective wall 6. It is comprised with the electrolyte solution 7 enclosed. That is, the electrolytic solution 7 is interposed between the first transparent electrode 1 and the second transparent electrode 4 in a form surrounded by the first transparent electrode 2, the protective wall 6, and the second transparent electrode 4. ing.

  Here, the protective wall 6 is not particularly limited as long as it has solvent resistance. However, it is usually preferable to use an ultraviolet curable resin that can be liquid-cured.

  Also, the spacer 8 is not particularly limited as long as it has solvent resistance. For example, a fluorine resin can be used.

  Next, the electrolytic solution composition constituting the electrolytic solution 7 will be described in detail.

  In the electrolytic solution composition, a first metal compound containing at least a first metal, a second metal compound having a decoloring function with respect to the first metal, and a supporting electrolyte are dissolved in a solvent.

Here, the first metal compound is not particularly limited as long as an oxidation-reduction reaction is caused by voltage application and the first metal is deposited on the surface of the first transparent electrode 2. Ag compounds and Bi compounds that reflect incident light with one metal can be preferably used. In particular, an Ag compound containing Ag having good reflectivity can be used more favorably. For example, Ag salts such as AgNO ₃ , AgBr, AgI, AgCl, AgCH ₃ COO, Ag complex salt alone or these may be used. Combinations can be used with preference.

The second metal compound is not particularly limited as long as it has a decoloring function with respect to the first metal at the time of natural standing by canceling voltage application or application of reverse voltage. A Cu compound is widely used as the second metal compound having the decoloring function. That is, as the second metal compound, Cu salts such as Cu (NO ₃ ) ₂ , CuBr ₂ , CuBr, CuI, CuCl ₂ , and Cu complex salts can be used alone or in combination of these.

  The supporting electrolyte is not particularly limited, but a halogen compound that causes a reduction reaction in contrast to the oxidation reaction of the first metal compound such as an Ag salt can be preferably used. Of the halogen compounds, Br salts such as NaBr, KBr, LiBr, and TBABr (tetrabutylammonium bromide) can be particularly preferably used.

  And in this electrolyte composition, the solvent composition is prepared so that a freezing point may be -20 degrees C or less, and the said solvent consists of an organic compound which has a sulfinyl group (-S (= O)-) at least. One kind of specific solvent is contained in an amount of 60 wt% or more.

  That is, in order to operate the optical device in a cold region or the like, it is necessary to be able to be easily driven even in a low temperature atmosphere of −20 ° C. or lower, and for that purpose, the freezing point of the electrolytic solution composition needs to be −20 ° C. or lower. There is.

  On the other hand, as described in Patent Document 1, the organic compound having a sulfinyl group can be driven at a low voltage of −2.5 V and has a decoloring function with respect to the first metal. By including the compound in a solvent, it is possible to realize a substantially colorless and low color at the time of transmission.

  However, even if the structural unit contains a sulfinyl group, DMSO as represented by the chemical formula (1) has a high freezing point of + 18 ° C. Therefore, even if it can be driven at a low voltage at room temperature, it solidifies at a low temperature. It cannot be driven and cannot be driven at a desired low temperature.

  Therefore, in the present embodiment, the composition is adjusted so that the freezing point of the electrolytic solution composition is −20 ° C. or lower and the organic compound containing a sulfinyl group is the main solvent.

  The organic compound as the main component of the electrolyte solvent is not particularly limited as long as it contains a sulfinyl group. However, TMSO represented by the chemical formula (2) having a freezing point of −45 ° C. or a freezing point FAMSO represented by the chemical formula (3) having a temperature of −100 ° C. or lower can be preferably used.

  If the freezing point of the electrolyte composition is −20 ° C. or lower, it is also preferable to include the above DMSO having good low voltage drivability in addition to TMSO and FAMSO, thereby further reducing low voltage drivability. Can be secured.

  In addition, the organic compound having a sulfinyl group, that is, the specific solvent is excellent in low voltage driving performance and low colorability, but the solvent may not be formed only with these specific solvents, Among them, it may be at least 60 wt% or more. That is, if the content of the specific solvent in the solvent is less than 60 wt%, the low voltage driveability and the low colorability may be lowered. Therefore, the specific solvent needs to be at least 60 wt% in the solvent.

  On the other hand, from the viewpoint of lowering the freezing point to −20 ° C. or lower and improving the voltage resistance of the electrolytic solution itself, if the content of the specific solvent in the solvent is 60 wt% or more, the solvent type does not have a sulfinyl group. It is also preferable to contain.

  The solvent having no sulfinyl group is not particularly limited as long as it has a freezing point of −20 ° C. or less and a wide potential window. For example, N-methyl-2-pyrrolidine having an amide group , Dimethylacetamide, pyridine, dimethylformamide, diethylformamide, N-ethylacetamide, tri-n-butylamine, N-ethylformamide, 1,3-dimethyl-3,4,5,6-tetrahydro-2-pyrimidinone, having a hydroxyl group Organic compounds containing methanol, ethanol, 2-propanol, 2-ethylhexanol, trimethyl phosphate having a phosphoric acid group, polyphosphoric acid, and further a lactone group, a carbonate group, a nitrile group, or the like can be used.

  In particular, lactone organic compounds having a lactone group such as γ-butyrolactone represented by chemical formula (4), γ-valerolactone represented by chemical formula (5), β-propiolactone represented by chemical formula (6), and chemical formula (7) 1,2-butylene carbonate shown, carbonate organic compound having a carbonate group such as propylene carbonate shown in chemical formula (8), acetonitrile shown in chemical formula (9), 3-methoxypropionitrile shown in chemical formula (10), chemical formula ( The nitrile organic compound having a nitrile group such as 2-methylglutaronitrile shown in 11) can be used more preferably from the viewpoint of voltage resistance.

  Next, the manufacturing method of the said electrolyte composition is explained in full detail.

  First, a solvent is prepared by the following method. That is, at least one organic compound having a sulfinyl group to be a specific solvent is prepared, and an organic compound having a freezing point of −20 ° C. or less without a sulfinyl group is prepared as necessary. And the said organic compound is weighed and prepared so that the freezing point of electrolyte solution composition may be -20 degrees C or less, and a specific solvent may be 60 wt% or more in a solvent, and electrolyte solution solvent is produced.

  The freezing point of the electrolyte composition can be easily measured by using a differential scanning calorimetry (hereinafter referred to as “DSC”) method, but in a cooled state at −20 ° C. If the liquid state is maintained, it can be inferred that it has a freezing point of −20 ° C. or lower without measuring the freezing point.

Next, a first metal compound such as an Ag salt, a second metal compound such as a Cu salt, and a supporting electrolyte such as a Br salt are prepared. Then, the first and second metal compounds, and the supporting electrolyte was added to the electrolyte solvent, thoroughly stirred in an inert gas atmosphere such as Ar atmosphere or an N ₂ atmosphere, first and second metal compounds And the supporting electrolyte are dissolved in a solvent, whereby an electrolytic solution composition is produced.

  Here, the molar concentration of the first metal compound in the electrolytic solution composition is not particularly limited as long as a desired amount of metal deposition occurs on the surface of the first transparent electrode 2 by the oxidation-reduction reaction. 5 mol / L or less is preferable, More preferably, it is 0.001-1 mol / L, More preferably, it is 0.005-0.1 mol / L.

  Further, the molar concentration of the second metal compound is not particularly limited as long as a desired decoloring function can be expressed with respect to the first metal, and can be adjusted by other component compositions. Usually, 0.001-0.02 mol / L or less is preferable, More preferably, it is 0.001-0.005 mol / L.

  Further, the molar concentration of the supporting electrolyte is not particularly limited, but is preferably about 5 times that of the first metal compound, for example, 25 mol / L or less, more preferably 0.005 to 5 mol / L, still more preferably. Is 0.025 to 0.5 mol / L.

  As described above, the present electrolytic solution composition includes at least a first metal compound such as an Ag compound containing the first metal, a second metal compound such as a Cu compound having a decoloring function with respect to the first metal, and Br. An electrolyte composition in which a supporting electrolyte such as a compound is dissolved in a solvent, wherein the freezing point is −20 ° C. or lower, and the solvent comprises at least one specific solvent composed of an organic compound having a sulfonyl group. Since it is contained at 60 wt% or more, the first metal is deposited by driving at a low voltage in a low temperature atmosphere of −20 ° C. or less, and the second metal compound has a decoloring function with respect to the first metal. When the reverse voltage is applied, the first metal is dissolved in the solvent. As a result, a low-colored electrolytic solution composition having good permeability can be obtained without causing initial coloration due to the interaction between the second metal contained in the second metal compound and the solvent. Can do.

  The optical device can be easily manufactured using the electrolytic solution composition as follows.

  First, a first transparent electrode 2 made of ITO having a thickness of 0.1 to 0.5 μm is formed on one main surface of the first transparent substrate 1 such as a glass substrate using a thin film forming method such as a sputtering method. Form. Similarly, the second transparent electrode 4 made of ITO or the like is formed on one main surface of the second transparent substrate 5.

  Next, an ultraviolet curable resin is linearly applied to the outer periphery of the surface of the first transparent electrode 2 to form a coating film. At this time, an opening is provided in a part of the coating film so that the electrolyte composition can be injected.

  Next, a spacer 8 made of fluororesin or the like having a thickness of 100 to 2000 μm is disposed on the outer peripheral portion of the coating film, and the second transparent substrate 5 on which the second transparent electrode 4 is further formed is placed on the coating film and the spacer 8. Placed on. Thereafter, this is irradiated with ultraviolet rays, and the first transparent substrate 1, the first transparent electrode 2, the coating cured film having the opening, the second transparent electrode 4, and the second transparent substrate 5 are sequentially laminated. An empty cell is produced.

  In addition, since the spacer 8 is provided in order to ensure the distance between the 1st transparent electrode 2 and the 2nd transparent electrode 5, you may remove after preparation of an empty cell.

  Next, the produced electrolytic solution composition is injected from the opening of the coating cured film, and thereafter, the opening is sealed with an ultraviolet curable resin that can be liquid-cured, whereby the protective wall 6 is produced. As a result, the electrolytic solution 7 is surrounded by the protective wall 6 and the first and second transparent electrodes 2, 4, and an optical device is manufactured.

  Next, the operation principle of this optical apparatus will be described.

  2A and 2B are diagrams schematically illustrating the operation state of the optical device. FIG. 2A illustrates a reflection mode in which incident light is reflected, and FIG. 2B illustrates a transmission mode in which incident light is transmitted. ing.

  That is, when a low voltage (for example, −2.3 to −2.7 V) is applied between the first transparent electrode 2 and the second transparent electrode 4, the electrolytic solution causes an oxidation-reduction reaction, The first metal compound is reduced, and the first metal is deposited on the surface of the first transparent electrode 2 which is the working electrode, and a metal film 9 is formed as shown in FIG. At this time, the supporting electrolyte is oxidized on the second transparent electrode 4 side which is the counter electrode of the first transparent electrode 2.

  Then, the optical device is in a reflection mode, and incident light such as sunlight is reflected by the metal film 9 as indicated by an arrow P, and the incident light does not pass through the optical device.

  On the other hand, when the voltage application is released and left as it is or when a reverse voltage is applied between the first and second transparent electrodes 2 and 4, an oxidation-reduction reaction occurs again, as shown in FIG. The metal film 9 is oxidized and dissolved in the electrolytic solution 7, and the supporting electrolyte ions generated by the second transparent electrode 4 are reduced. At this time, the second metal compound promotes the decoloring of the first metal, and initial coloration due to the interaction between the second metal ion contained in the second metal compound and the solvent does not occur. The electrolyte solution 7 is substantially colorless and low-colored.

  Then, the optical device is in a transmission mode, and incident light such as sunlight passes through the low-colored electrolyte 7 as indicated by an arrow Q.

For example, when an Ag salt such as Ag (NO ₃ ) is used as the first metal compound, a Cu salt such as CuCl ₂ is used as the second metal compound, and a Br salt such as LiBr is used as the supporting electrolyte, FIG. As shown in (a), when a low voltage is applied between the first transparent electrode 2 and the second transparent electrode 4, the chemical reaction formula (A) is shown on the first transparent electrode 2 side. Further, Ag ions in the Ag salt are reduced, and a metal film 9 made of Ag is formed on the surface of the first transparent electrode 2. Then, the optical device is in the reflection mode, and the incident light indicated by the arrow P is reflected by the metal film 9 in the mirror state. At this time, on the second transparent electrode 4 side, as shown in the chemical reaction formula (B), the Br salt is oxidized to produce Br ³⁻ .

Ag ⁺ + e ⁻ → Ag ... (A)
3Br ⁻ → Br ³ + 2e ⁻ (B)

On the other hand, as shown in FIG. 2B, when a reverse voltage is applied between the first transparent electrode 2 and the second transparent electrode 4, a chemical reaction formula is generated on the first transparent electrode 2 side. As shown in (C), Ag is oxidized and becomes Ag ions and dissolves in the electrolytic solution 7. On the second transparent electrode 4 side, as shown in the chemical reaction formula (D), Br ³⁻ is reduced to produce Br ⁻ .

Ag → Ag ⁺ + e ⁻ (C)
Br ^3- + 2e ⁻ → 3Br ⁻ ... (D)

  And since the electrolyte solution 7 contains Cu salt which has the decoloring function with respect to Ag, the electrolyte solution 7 decolorizes Ag. In addition, initial coloration due to the interaction between the divalent Cu ions and the solvent does not occur, and the color becomes substantially colorless and low coloration.

  In the optical device thus set in the transmission mode, the incident light passes through the optical device and is emitted to the outside as indicated by an arrow Q.

  Further, in FIG. 2B, even when the voltage application is released and left to stand naturally, the transmission mode can easily appear through the decoloring function of the second metal compound.

  For example, in the same manner as described above, when an Ag salt is used for the first metal compound, a Cu salt is used for the second metal compound, and a Br salt is used for the supporting electrolyte, on the first transparent electrode 2 side, the chemical reaction formula (E), As shown in (F), a redox reaction occurs between the Cu salt and Ag, Cu ions in the electrolytic solution 7 are reduced to oxidize Ag, and Ag dissolves in the electrolytic solution 7.

Cu ²⁺ + e ⁻ → Cu ⁺ (E)
Ag → Ag ⁺ + e ⁻ (F)

In the electrolytic solution 7, as shown in chemical reaction formulas (G) and (H), an oxidation-reduction reaction occurs between Br ³⁻ and Cu ⁺ generated on the second transparent electrode 4 side, and Br ^3- is reduced to Br ⁻ and Cu ⁺ is oxidized to Cu ²⁺ .

Br ^3- + 2e ⁻ → 3Br ⁻ ... (G)
Cu ⁺ → Cu ²⁺ + e ⁻ (H)

Thus, the Cu salt mediates the oxidation of Ag and the reduction of Br ^3- , whereby Cu can erase the color of Ag and realize the transmission mode.

  As described above, the optical device is an optical device in which the electrolyte layer 3 is interposed between a pair of transparent electrodes (first and second transparent electrodes 2 and 4), and the electrolyte layer 3 includes the electrolyte solution 7. Therefore, it is possible to realize a reflection mode having good reflectivity by depositing the first metal on the surface of the eleventh transparent electrode 2 by being driven at a low temperature atmosphere and a low voltage. Alternatively, a low-color transmission mode with good transparency can be realized by applying a reverse voltage.

  Further, by repeating the low voltage application and the natural standing or the reverse voltage application in the electrolytic solution composition, the oxidation-reduction reaction is repeated in the electrolytic solution, so that an optical device having good repeated durability can be obtained.

  The present invention is not limited to the above embodiment.

  For example, from the viewpoint of improving the viscosity of the electrolytic solution composition, it is also preferable to add a resin that does not decompose in a solvent and has good voltage resistance.

  Examples of such resins include acrylic resins such as polyvinyl butyral (PVB) and polymethacrylate (PMA), fluororesins such as polyvinylidene fluoride (PVDF), polyvinyl pyrrolidone (PVP), cellulose esters, and polyamides. Polycarbonates, polyepoxies, polyurethanes, polyvinyl acetal (PVA), polyacrylonitrile (PAN), or copolymers thereof can be used.

  In addition, an electrolyte composition in a polymer such as polyethylene oxide (PEO), polymethacrylate (PMA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), etc. It is also possible to form a sheet and use it as a solid electrolyte or gel electrolyte.

  It is also possible to use a polymer having a crosslinkable group. In this case, the polymer having the crosslinkable group and the electrolytic solution composition are first mixed, and then the crosslinkable group of the polymer is changed to electron beam crosslink, thermal crosslink, ultraviolet ray. Crosslinking can be performed using a crosslinking method such as crosslinking.

  Next, examples of the present invention will be specifically described.

[Preparation of electrolyte composition]
TMSO, FAMSO and DMSO are prepared as solvents having a sulfinyl group (specific solvents), and 1,2-butylene carbonate (hereinafter referred to as “1,2-BC”), γ-butyrolactone as a solvent having no sulfinyl group. (Hereinafter referred to as “GBL”).

  Next, using a DSC apparatus (Q20 manufactured by TA Instruments), the freezing point of each solvent was measured.

 That is, thermally inactive α-alumina is used as a reference material, a solvent sample and a reference material are set in a sample holder, and a DSC apparatus is set at a speed of 20 ° C./min within a range of −100 ° C. to + 20 ° C. The temperature was raised at. In this case, the reference material increases in proportion to the temperature in the apparatus. On the other hand, the solvent sample exhibits the same behavior as the reference material when no thermal change occurs, but when the thermal change occurs, it exhibits a behavior different from that of the reference material and causes an exothermic reaction. Therefore, when the temperature difference between the reference substance and the sample is plotted against time, a convex exothermic peak occurs when an exothermic reaction occurs. And the exothermic peak at the time of temperature rise was made into the freezing point of a solvent sample.

  Note that the same exothermic peak occurs when cooled from a high temperature, but overheating tends to lower the exothermic peak. Therefore, since there is a possibility that the freezing point may be lower than the actual value, the freezing point was measured by gradually increasing from −100 ° C.

  Table 1 shows the measurement results of the freezing point of each solvent.

  As apparent from Table 1, the freezing points of TMSO, GBL, and 1,2-BC were −43 to −45 ° C., and the freezing point of DMSO was + 18 ° C. In FAMSO, no exothermic peak occurred in the range of −100 ° C. to + 20 ° C., so the freezing point is considered to be −100 ° C. or lower.

  Subsequently, each of these solvents was combined, and the solvent composition was prepared so as to have a weight ratio shown in Table 2 to prepare an electrolyte solution solvent.

  The weight ratio of these electrolyte solvents was also confirmed by a thermal extraction analysis method using a gas chromatograph-mass spectrometer (GCMS) apparatus (GCMS-QP2010SE manufactured by Shimadzu Corporation).

Next, AgNO ₃ was prepared as the first metal compound, CuCl ₂ was prepared as the _second metal compound, and LiBr was prepared as the supporting electrolyte. Then, these _{concentrations, AgNO 3: 0.025mol / L,} CuCl 2: 0.005mol / L, LiBr: As will be 0.25 mol / L, was added to each solvent, further PVB resin and 3 wt% Thus, the electrolyte solution compositions of Sample Nos. 1 to 14 were produced.

The electrolytic solution composition was prepared by stirring the pot mill for 12 hours in a glove box adjusted to 40 ° C. in an inert atmosphere such as Ar gas or N ₂ gas.

[Preparation of measurement sample]

  A pair of glass substrates (first and second glass substrates) having a thickness of 1.1 mm, in which an ITO film (transparent electrode) having a thickness of 0.2 μm was formed on one main surface, was prepared. An ITO film having a specific resistance of 10 Ω · cm was used.

  Next, an epoxy-based ultraviolet curable resin is applied so as to have an opening on the outer periphery of the ITO film on the first glass substrate side to form a coating film, and fluorine having a thickness of 300 μm is formed on the outer periphery of the coating film. A resin sheet (spacer) made of resin was provided. And the 1st and 2nd glass substrate was distribute | arranged on both surfaces of the resin sheet so that the distance between ITO films | membranes might be 300 micrometers, and the empty cell was produced by irradiating an ultraviolet-ray.

  Next, the electrolyte compositions of Sample Nos. 1 to 14 were respectively injected from the openings, and then the openings were sealed with a liquid curable resin, thereby preparing measurement samples of Sample Nos. 1 to 14.

[Evaluation of measurement sample]
The measurement samples of sample numbers 1 to 14 were set to −20 ° C., and whether or not the samples were solidified was visually confirmed.

  Next, the reflection state and coloring state of each sample were confirmed.

  As for the reflection state, a digital fiber amplifier (E3X-DA11AN manufactured by OMRON Corporation) is used as a light source, and a measurement sample is irradiated with a light beam having a wavelength of 635 nm at room temperature (25 ° C.). A voltage of −2.7 V was applied, and the reflectance at that time was measured and evaluated. The reflectance was calibrated by using a reflective lens unit (E39-F3B manufactured by OMRON Corporation) and measuring the relative reflectance with the reflectance of the mirror body set to 100%.

  Then, a measurement sample having a relative reflectance of 40% or more was determined to be a non-defective product “◯”, and a measurement sample having a relative reflectance of less than 40% was determined to be a defective product “x”.

  On the other hand, the colored state was evaluated by leaving the measurement sample naturally, using the digital fiber amplifier described above as a light source, irradiating the measurement sample under the same conditions as described above, and measuring the transmittance at that time. The transmittance calibration was performed in a blank state in which nothing was sandwiched between the measurement samples.

  Then, a measurement sample having a transmittance of 75% or more was judged as a non-defective product as low-colored colorless, and a measurement sample having a transmittance of less than 75% was judged as a defective product with a colored state as colored.

  Moreover, about the sample numbers 1, 9, and 10, the DSC apparatus mentioned above was used and the freezing point was measured.

  Table 2 shows the solvent composition of each sample Nos. 1 to 14, the state at −20 ° C., the reflection state when a voltage of −2.3 V and −2.7 V is applied, the coloring state of the electrolyte, and the freezing point. Yes.

  Sample No. 11 can be driven at a low voltage of −2.3 V, and the colored state is colorless and has low colorability. However, since the solvent is formed only with DMSO having a freezing point of + 18 ° C., − It was found that the electrolytic solution composition was solidified at 20 ° C. and could not be driven at a low temperature.

  In Sample No. 12, since the solvent is formed of GBL having a freezing point of −43 ° C., the liquid is maintained even at −20 ° C. However, since GBL does not have a sulfinyl group, −2.7 V It could not be driven at a low voltage, and the colored state was dark orange due to Cu, indicating that it was inferior in low colorability.

  Sample No. 13 can be driven at a low voltage of −2.3 V, and the colored state is also colorless, and although it has low colorability, it has been found that it partially solidifies at −20 ° C. Although it contains TMSO and DMSO having a sulfinyl group as a solvent, DMSO having a freezing point of + 18 ° C. is excessively contained. Therefore, even if TMSO is contained, the electrolyte composition is not used at −20 ° C. It seems that it was partially solidified and could not be completely liquid.

  Sample No. 14 contains 50 wt% GBL having a freezing point of −43 ° C. as a solvent, so that a liquid state can be secured at −20 ° C., but this GBL does not contain a sulfinyl group, and therefore −2 It is possible to drive at a low voltage of .3V, but the transmittance is low, the color is orange, and the low colorability is poor.

  On the other hand, Sample Nos. 1 to 10 were found to have a solidification point of −20 ° C. or lower because the state at −20 ° C. was liquid. Moreover, since the organic compound having a sulfinyl group as the specific solvent is 60 wt% or more in the solvent, it can be driven at a low voltage of −2.7 V, and the colored state is colorless and low colorability can be secured, and the low temperature is low. It was found that voltage driving was possible and the coloration was low.

  In particular, it was confirmed that driving at a lower voltage of -2.3 V was possible by combining FAMSO alone or a combination of two or more specific solvents.

  It was also found that if the solvent contains at least 60 wt% of the specific solvent, it is possible to use a mixed solvent with an organic compound having a low freezing point that does not contain a sulfinyl group.

  As is clear from the measurement results of the freezing points of sample numbers 1, 9, and 10, it was also confirmed that the freezing point of the electrolytic solution composition was sufficiently lower than −20 ° C.

  It is possible to realize an electrolyte composition that can be driven at a low voltage in a low-temperature atmosphere and has low colorability, and an optical device that can repeatedly perform a desired reflection mode and transmission mode.

2 First transparent electrode 3 Electrolyte layer 4 Second transparent electrode 7 Electrolytic solution

Claims (8)

An electrolyte composition in which a first metal compound containing at least a first metal, a second metal compound having a decoloring function with respect to the first metal, and a supporting electrolyte are dissolved in a solvent,
The freezing point is −20 ° C. or lower,
And the said solvent contains 60 wt% or more of at least 1 sort (s) of specific solvent which consists of an organic compound which has a sulfinyl group, The electrolyte solution composition characterized by the above-mentioned.   The electrolytic solution composition according to claim 1, wherein the organic compound contains at least one of tetramethylene sulfoxide and methyl (methylsulfinyl) methyl sulfide.   The electrolytic solution composition according to claim 2, wherein the organic compound includes dimethyl sulfoxide.   The electrolyte solution composition according to any one of claims 1 to 3, wherein the solvent contains at least one of a lactone compound, a carbonate compound, and a nitrile compound. object.   The electrolytic solution composition according to claim 1, wherein the first metal compound includes an Ag compound.   The electrolytic solution composition according to claim 1, wherein the second metal compound contains a Cu compound.   The electrolytic solution composition according to claim 1, wherein the supporting electrolyte contains a halogen compound. An optical device in which an electrolyte layer is interposed between a pair of transparent electrodes,
The optical device comprising the electrolytic solution composition according to claim 1, wherein the electrolyte layer includes the electrolytic solution composition according to claim 1.

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