JP2012155099A - Electrochromic mirror - Google Patents

Abstract

An electrochromic mirror in which deterioration of an electrochromic film is suppressed while keeping coloring / decoloring reactivity good is provided.
The electrochromic mirror 10 includes an electrochromic film 16, conductive reflective films 18, 20, a conductive film 26, and an electrolytic solution 34 containing lithium ions, and includes a metal. A porous metal-containing film having a first conductive reflective film 18 having a hole 48 and a hole 50 penetrating in the thickness direction and having a smaller inner diameter than the hole 48 of the first conductive reflective film 18. And a second conductive reflective film 20.
[Selection] Figure 2

Description

  The present invention relates to, for example, an electrochromic mirror that is used for an outer mirror or an inner mirror for confirming the rear of a vehicle and has a reflectivity variable by applying a voltage.

The electrochromic mirror used to check the back of the vehicle is a function that reduces glare by applying a voltage in response to strong light from the back during night driving and changing the reflectivity. Have In addition, there is a mode in which the reflectance is reduced more than in the daytime by applying voltage during night driving, and in the daytime driving, the reflectance is sufficient without applying a voltage.
As an electrochromic mirror, a transparent lithium ion permeable film is provided between the electrochromic film and the reflective film, and the reflective film using a metal such as palladium undergoes a reduction reaction due to the movement of lithium ions, thereby discoloring. (For example, refer to Patent Document 1). However, the reflective film using palladium is not sufficient in reflectance, and attempts have been made to use aluminum as a metal having higher reflectance. However, the reflective film using aluminum has a problem in durability because it is easily corroded by the influence of an electrolytic solution containing lithium ions.
Therefore, as a technique with excellent reflectivity and improved durability, the surface of the first conductive reflective film that mainly reflects light is less likely to corrode as a protective layer than the first conductive reflective film. A technique for providing a second conductive reflective film containing a metal has been proposed (see, for example, Patent Document 2).

U.S. Pat. No. 3,844,636 JP 2009-8747 A

However, although the durability of the reflective film is improved, since the permeation of lithium ions is suppressed by the protective layer, there is a slight decrease in coloring and decoloring reactivity, especially at a low temperature of −30 ° C. or lower. Since there is a problem that the reactivity is significantly reduced in an atmosphere, it becomes a practical problem when used for an antiglare mirror for automobiles that can be used even in an environment below freezing point, for example, −30 ° C. or less depending on the season. Therefore, suppression of the decrease in responsiveness has been desired.
The present invention has been made in consideration of the above-described facts, and an object of the present invention is to provide an electrochromic mirror in which the deterioration of the electrochromic film is suppressed while maintaining good coloring / decoloring reactivity.

As a result of intensive studies, the inventor of the through-hole included in the metal film constituting the first conductive reflective film that mainly reflects light and the second conductive reflective film that functions as a protective layer thereof. The inventors have found that the above problems can be solved by controlling the relative relationship between the inner diameters, and have completed the present invention. That is, the configuration of the present invention is as follows.
An electrochromic mirror according to claim 1 of the present invention is provided on one side in the thickness direction of an electrochromic film colored by a reduction reaction and the electrochromic film, and transmits light transmitted through the electrochromic film. A first conductive reflective film that is a porous metal-containing film that reflects and has conductivity and has a hole penetrating in the thickness direction, and one side in the thickness direction of the first conductive reflective film. Second conductivity, which is a porous metal-containing film that is provided on the opposite side of the electrochromic film, penetrates in the thickness direction, and has a smaller inner diameter than the holes of the first conductive reflective film. A reflective film; a conductive film having conductivity provided on a side opposite to the first conductive reflective film in a thickness direction of the second conductive reflective film; Membrane and said conductivity When the voltage is applied with the conductive film being positive and the conductive reflective film or the protective film being negative, the lithium ions move to the electrochromic film side, and the electro And an electrolytic solution used for a reduction reaction of the chromic film.

In the electrochromic mirror according to the first aspect of the present invention, since the through hole having a smaller inner diameter than that in the first conductive reflective film is formed in the second conductive reflective film, the electrolyte solution In the hole effective for passage, the side wall surface of the metal (the outer peripheral surface of the hole) constituting the first conductive reflective film existing deeper than the second conductive reflective film is the second conductive reflective film. Since it is receding from the side wall surface of the through-hole, it is difficult to form a potential barrier in the through-hole. For this reason, lithium ions resulting from the formation of a potential barrier in the through-hole provided for the passage of lithium ions In the case of using two types of metals, the function of the protective layer by the second conductive reflective film is expressed while maintaining high responsiveness while maintaining high responsiveness and maintaining high responsiveness. Degradation of electrochromic film is suppressed Considered shall.
In the present invention, since the first and second conductive reflective films have fine through holes, lithium ions of the electrolytic solution are formed in each of the first conductive reflective film and the second conductive reflective film. The electrochromic film can be easily reached through the through-holes, and a reduction reaction occurs in the electrochromic film. Accordingly, since the conductive reflective film has through-holes in the thickness direction, the coloring / decoloring reactivity is further improved.

The electrochromic mirror according to the present invention described in claim 2 is the electrochromic mirror according to the present invention described in claim 1, wherein the metal contained in the second conductive reflective film is contained in the first conductive reflective film. It is a metal that is harder to corrode than a metal.
Since the second conductive reflective film functions more as a protective layer of the first conductive reflective film by using a metal that does not easily corrode for the second conductive reflective film, the durability of the electrochromic mirror is increased. Is further improved.

An electrochromic mirror according to a third aspect of the present invention is the electrochromic mirror according to the first aspect, wherein when the inner diameter of the hole penetrating in the thickness direction of the second conductive reflective film is 100, The inner diameter of the hole penetrating in the thickness direction of the first conductive reflective film is 104 or more and 120 or less.
When the inner diameter of the through hole in the second conductive reflective film is 100, the inner diameter of the through hole in the first conductive reflective film is 104 or more, so that the effect of the present invention is improved. Further, even if the inner diameter of the through hole of the first conductive reflective film is increased beyond 120, the effect is not improved, and there is a concern that the durability of the film is lowered.

  As described above, in the electrochromic mirror according to the present invention, deterioration of the electrochromic film is suppressed while maintaining good coloring / decoloring reactivity.

It is sectional drawing which shows the outline of the structural example of the electrochromic mirror of this invention. It is the schematic sectional drawing which expanded the principal part in the structural example of the electrochromic mirror shown in FIG. It is the schematic sectional drawing which expanded the principal part in the structural example of the electrochromic mirror which is a control example. It is a graph showing the time change of the coloring reflectance (%) after applying a voltage to an electrochromic mirror, and the time change of the decoloring reflectance (%) after switching a voltage to 0V after that.

FIG. 1 is a schematic sectional view showing an example of the configuration of an electrochromic mirror according to the present invention.
As shown in FIG. 1, the electrochromic mirror 10 includes a surface side substrate 12. The front-side substrate 12 includes a transparent substrate body 14 made of glass or the like. The material constituting the substrate body 14 is not particularly limited as long as it has transparency (translucency) suitable for constituting the surface of the mirror. For example, glass (inorganic glass) and resin can be mentioned.

An electrochromic film 16 is formed on one surface of the substrate body 14 in the thickness direction. The electrochromic film 16 is formed of, for example, tungsten trioxide (WO ₃ ), molybdenum trioxide (MoO ₃ ), or a mixture containing such an oxide. It is preferable that the electrochromic film 16 is formed of tungsten.
Moreover, there is no restriction | limiting in particular in the thickness of the electrochromic film | membrane 16 along the thickness direction of the substrate main body 14, For example, it can set in the range of 300 nm or more and 1000 nm or less. In the present invention, the thickness of the electrochromic film 16 is preferably 400 nm or more and 600 nm or less from the viewpoint of a decrease in reflectance.

  As a method of forming an electrochromic film on the substrate body, a method that is usually used can be applied without any particular limitation. For example, a vapor deposition method, a sputtering method, etc. can be mentioned.

A first conductive reflective film 18 is formed on the surface of the electrochromic film 16 opposite to the substrate body 14. The first conductive reflective film 18 has conductivity, and has a glossy surface on which fine voids (through holes) 48 penetrating in the thickness direction capable of transmitting lithium ions are formed. From the viewpoint of light reflectivity, the reflective film is preferably formed including a metal selected from rhodium (Rh), aluminum (Al), silver (Ag), indium (In), and the like.
The metal contained in the first conductive reflective film may be an alloy containing rhodium, aluminum, silver, and indium as long as the reflectivity is sufficient.

For example, the alloy containing silver is an alloy containing silver as a main component (50% by mass or more) and other metals, and the other metal contained in the silver alloy is preferably a metal material having high cation permeability. Specifically, rhodium (Rh), ruthenium (Ru), palladium (Pd), nickel (Ni), and the like can be given. Among them, an alloy containing palladium (Pd) is preferable. With such an embodiment, the cation permeability of the conductive reflective film is improved, and the response speed is improved.
The aluminum alloy is an alloy mainly composed of aluminum (50% by mass or more) and includes other metals. Examples of other metals included in the aluminum alloy include tungsten, tantalum, molybdenum, copper, and titanium. The corrosion resistance of aluminum is improved by using an alloy with these metals.

  The thickness of the first conductive reflective film 18 along the thickness direction of the substrate body 14 is not particularly limited, but can be set in the range of 30 nm to 200 nm, for example. In the present invention, from the viewpoint of conductivity and reflectance, the thickness of the first conductive reflective film 18 is preferably 50 nm or more and 120 nm or less, and preferably 50 nm or more and 100 nm or less.

  The first conductive reflective film 18 can be produced (deposited) by various physical or chemical vapor deposition methods. For example, a target material containing a metal (for example, rhodium, aluminum, silver, etc.) selected to be included in the first conductive reflective film is prepared, and various sputtering is performed using the target material. A conductive reflective film containing a metal can be formed on the electrochromic film.

FIG. 2 is a partially enlarged view showing aspects of the first conductive reflective film and the second conductive reflective film, which are the main parts of the present invention, in the electrochromic mirror shown in FIG. As shown in FIG. 2, the first conductive reflective film 18 is formed with a large number of fine through-holes 48 penetrating in the thickness direction. The second conductive reflective film will be described in detail below. A large number of fine through holes 50 penetrating in the thickness direction are also formed in the film 20. The through hole 48 and the through hole 50 communicate with each other. The inner diameters (inner peripheral diameters) of these through holes 48 and 50 are each preferably 20 μm or less. In particular, in the present embodiment, the inner diameter of the through hole 48 is set to 5.5 μm. . Here, the inner diameter of the through hole 50 in the second conductive reflective film needs to be smaller than the inner diameter of the through hole 48 in the first conductive reflective film. More specifically, when the inner diameter of the through hole of the second conductive reflective film is 100, the inner diameter of the through hole of the first conductive reflective film is preferably in the range of 104 to 120.
These through holes 48 and 50 are basically formed irregularly (randomly) in the first conductive reflective film 18 and the second conductive reflective film 20, respectively. However, the distance L between the centers of the adjacent through holes 48 and 50 is 10 μm. The center-to-center distance L is preferably in the range of 8 μm to 15 μm, and more preferably about 10 μm.

The through-hole 48 is exposed by applying a photomask on which the pattern of the through-hole 48 is printed on the first conductive reflective film 18 coated with the photoresist, and then removing the photoresist corresponding to the through-hole 48. The first conductive reflective film 18 is melted with an etching solution. Similarly, the through hole 50 in the second conductive reflective film is also formed by a photomask and etching.
At this time, the arrangement of the through-hole 48 and the through-hole 50 needs to be penetrated so as to overlap each other, and in order to form such a through-hole, the first conductive reflective film The through hole 48 formation position of the photomask and the formation position of the through hole 50 in the second conductive reflective film may be the same position, and only the inner diameter of the opening may be enlarged. A first conductive reflective film and a second conductive reflective film are stacked and formed, and after exposure from the second conductive reflective film side through a photomask, the second conductive reflective film is configured. Etching may be performed using a solution that hardly dissolves the metal to be dissolved and easily dissolves the metal constituting the first conductive reflective film. When the latter method is used, for example, aluminum is used as the first conductive reflective film, nickel is used as the second conductive reflective film, and a sodium hydroxide solution is used as the etching solution, which is then immersed for a predetermined time. Thus, the inner diameter of the through hole 48 formed in the first conductive reflective film can be made larger than the inner diameter of the through hole 50 formed in the second conductive reflective film.
At this time, the inner diameter of the through hole 48 formed in the first conductive reflective film can be controlled by controlling the concentration of the sodium hydroxide solution and the immersion time.

  Since the through holes 48 and 50 are fine openings having an inner diameter (diameter of the inner peripheral portion) D of 5.5 μm and 5 μm (that is, 20 μm or less), the through holes 48 and 50 are usually visually observed. The existence of can not be confirmed. For this reason, even if the through-hole 48 is formed in the first conductive reflective film, a sense of incongruity does not occur when the reflected light from the electrochromic mirror 60 is visually observed.

A second conductive reflective film 20 is formed on the surface of the first conductive reflective film 18 opposite to the electrochromic film 16. The second conductive reflective film 20 is formed so that the outer peripheral edge portion is located outside the outer peripheral edge portion of the first conductive reflective film 18. Thereby, the first conductive reflective film 18 is entirely covered with the second conductive reflective film 20 from the side opposite to the electrochromic film 16.
The second conductive reflective film 20 has a function as a protective layer with respect to the first conductive reflective film 18. The metal contained in the second conductive reflective film 20 preferably contains a metal that is less likely to corrode than the metal contained in the first conductive reflective film 18 from the viewpoint of improving durability.

That is, when the first conductive reflective film 18 is formed of aluminum (Al), silver (Ag), indium (In), or the like, the second conductive reflective film 20 is different from the first conductive reflective film 20 in the first. It is preferably formed of a metal that is less corroded than the conductive reflective film 18, such as rhodium (Rh), ruthenium (Ru), palladium (Pd), nickel (Ni), chromium (Cr), or the like.
By covering the first conductive reflective film 18 with the second conductive reflective film 20 that is resistant to corrosion of the electrolytic solution, the dissolution of the first conductive reflective film 18 is prevented, so that the electrochromic film 16 Improves durability.

An example of a preferable combination of metals contained in the first conductive reflective film and the second conductive reflective film in the case of adopting the present embodiment will be given below.
(1) First conductive reflective film: aluminum (Al), second conductive reflective film: chromium (Cr)
(2) First conductive reflective film: aluminum (Al), second conductive reflective film: nickel (Ni)
(3) First conductive reflective film: aluminum (Al), second conductive reflective film: rhodium (Rh)
(4) First conductive reflective film: aluminum (Al), second conductive reflective film: ruthenium (Ru)

  Although there is no restriction | limiting in particular in the thickness of the said 2nd electroconductive reflection film 20, For practical use, it can set in the range of 10 nm or more and 200 nm or less, for example. In the present invention, from the viewpoint of effectively suppressing degradation of the electrochromic film 16, the thickness of the second conductive reflective film 20 is preferably 20 nm or more and 80 nm or less.

Similar to the first conductive reflective film 18, the second conductive reflective film 20 can be formed (formed) by various physical or chemical vapor deposition methods. That is, by preparing a target material containing a predetermined metal selected in consideration of the relationship with the metal contained in the first conductive reflective film and performing various sputtering using the target material, the second material is obtained. The conductive reflective film 20 can be formed on the first conductive reflective film 18.
After forming the second conductive reflective film 20 on the first conductive reflective film 18, as described above, exposure is performed from the second conductive reflective film side through the photomask, and the photomask. And a through hole 48 having a relatively large inner diameter and a through hole 50 having a smaller inner diameter than the through hole 48 can be simultaneously formed by etching with a specific etching solution in consideration of solubility in these metals. That's fine.

The back side substrate 24 is provided on one side in the thickness direction of the front side substrate 12 having the above configuration so as to face the front side substrate 12. The back surface side substrate 24 includes a transparent substrate body 26 made of glass or the like. A conductive film 28 is formed on the other side in the thickness direction of the substrate body 26, that is, on the surface on the surface-side substrate 12 side. The conductive film 28 is made of a metal such as chromium (Cr) or nickel (Ni), indium tin oxide (In ₂ O ₃ : Sn, so-called “ITO”), tin oxide (SnO ₂ ), fluorine-doped tin oxide (SnO). ₂ : F), zinc oxide (ZnO ₂ ), and the like, and a mixture of these is preferable.
The conductive film 28 can be formed (deposited) by various physical or chemical vapor deposition methods, similarly to the conductive reflective films 18 and 20.

A conductive carbon film 30 is formed on the surface of the conductive film 28 on the surface side substrate 12 side. The carbon film 30 is formed including at least one selected from graphite, carbon black, and activated carbon, and preferably includes 50% by weight or more of activated carbon. By including activated carbon as the carbon material, the surface area of the electrode increases, the flow of electrons (current) becomes smoother, and the voltage loss is reduced. The activated carbon surface also serves as a suitable place for a catalyst that can easily generate hydrogen ions.
Furthermore, by including a carbon material such as graphite, the hydrogen ion absorption ability in the electrode layer can be improved, and the transfer of hydrogen ions from the electrochromic film to the electrolyte can be promoted when the application of voltage is released. . Furthermore, by including carbon black together with activated carbon and graphite, the degree of electrical contact between the main components (activated carbon, graphite, etc.) constituting the carbon electrode can be improved. A configuration having such a function is referred to as redox compensation means.
The carbon film 30 preferably further includes at least one synthetic resin material such as a phenol resin, a polyimide resin, and an acrylic resin as a binder.
Further, instead of providing the carbon film 30, a compound capable of causing a redox reaction may be added to the electrolytic solution to form a redox compensation means.

The thickness dimension of the carbon film 30 along the thickness direction of the substrate body 26 is preferably 50 μm or more.
As the method for forming the carbon film 30, for example, several types of carbon materials (for example, activated carbon, graphite, and carbon black described above) are used as appropriate binders (for example, cellulose binders such as carboxymethyl cellulose, phenol resins, polyimides). Mixed with a resin, a synthetic resin binder such as acrylic resin), and coated on the back side substrate 26 on which the conductive film 28 is formed by a known method such as a doctor blade method, and an appropriate temperature (for example, 150 ° C.). The film can be formed by heating at ~ 200 ° C.

  A predetermined gap is formed between the front surface side substrate 12 and the back surface side substrate 24 having the above configuration, and a sealing material is provided between the outer peripheral portion of the front surface side substrate 12 and the outer peripheral portion of the back surface side substrate 24. 32 is sealed. An electrolytic solution 34 is sealed in a space surrounded by the front surface side substrate 12, the back surface side substrate 24, and the sealing material 32. The electrolytic solution 34 has a solvent formed of propylene carbonate, ethylene carbonate, butylene carbonate, diethyl carbonate, γ-butyrolactone, dimethylformamide, or the like, or a mixture thereof. In particular, in the present invention, propylene carbonate is a solvent. It is preferable to be used as

In addition to the solvent, the electrolyte 34 is composed of lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium bis (trifluoromethanesulfonyl) imide. (LiN (SO ₂ CF ₃ ) ₂ ), lithium bis (pentafluoroethanesulfonyl) imide (LiN (SO ₂ C ₂ F ₅ ) ₂ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), etc., and mixtures thereof In particular, in the present invention, lithium perchlorate is preferably used as the electrolyte.

Furthermore, the conductive film 28 of the electrochromic mirror 10 having the above configuration is connected to a switch 42 that constitutes the circuit 40. The switch 42 is connected to a terminal connected in the ON state by a battery or the like mounted on the vehicle, and is connected to the positive electrode of a DC power supply 44 having a rated voltage of about 1.3V. The negative electrode of the DC power supply 44 is connected to the conductive reflective film 18. The terminal connected when the switch 42 is in the OFF state is connected to the conductive reflective film 18 without passing through the DC power supply 44, and in the OFF state, the conductive reflective film 18 and the conductive film 28 are short-circuited. Is done.
Although not shown, the negative electrode of the DC power supply 44 is connected to the protective film 36, and the terminal to which the switch 42 is connected in the OFF state is connected to the protective film 36 without passing through the DC power supply 44. In a state, the protective film 36 and the conductive film 28 may be short-circuited.

  In the electrochromic mirror 10 having the above configuration, the electrochromic film 16 is substantially transparent when the switch 42 is in an OFF state. Therefore, light incident from the opposite side of the substrate body 14 from the electrochromic film 16 is The light passes through the substrate body 14 and the electrochromic film 16 and is reflected by the conductive reflective film 18. Further, the light reflected by the conductive reflective film 18 passes through the electrochromic film 16 and the substrate body 14. In the electrochromic mirror according to the present invention, the light reflectance is not particularly limited, and can be, for example, about 55%.

On the other hand, when the switch 42 is switched to the ON state, the electrons (e ⁻ ) that have moved through the circuit 40 toward the conductive reflective film 18 enter the electrochromic film 16, and at the same time, the lithium ions ( Li ⁺ ) penetrates the protective film 36 and the conductive reflective film 18 and enters the electrochromic film 16. As a result, a reduction reaction of the following formula 1 occurs in the electrochromic film 16, and blue Li _x WO ₃ called so-called tungsten bronze is formed in the electrochromic film 16.
Li ⁺ + e ⁻ + WO ₃ → Li _x WO ₃ (Formula 1)
As a result of the electrochromic film 16 being colored in blue in this way, the reflectivity, which was about 55 percent before the electrochromic film 16 was colored, is reduced to, for example, about 7 percent.

Furthermore, when the above reduction reaction occurs, electrons (e ⁻ ) move from the carbon constituting the carbon film 30 to the DC power supply 44 side, whereby negative ions derived from the salt constituting the electrolyte, for example, Then, negative ions (ClO ₄ ⁻ ) of lithium perchlorate move to the carbon film 30 side. As a result, a compensation reaction like the following formula 2 occurs with respect to the above reduction reaction.
ClO ₄ ⁻ + C−e ⁻ → C ⁺ · ClO ₄ ⁻ (Formula 2)

Further, the carbon film 30 contains not only activated carbon but also graphite and carbon ink, whereby the carbon film 30 is imparted with sufficient conductivity and the reaction in the carbon film 30 can be accelerated.
Furthermore, the provision of the carbon film 30 can reduce the voltage applied when coloring the electrochromic film 16. For this reason, when the switch 42 is turned off and the first conductive reflective film 18 and the conductive film 28 are short-circuited, a reaction opposite to that in the above formulas 1 and 2 occurs, and the electrochromic film 16 quickly moves. Discolored.

  When the electrochromic mirror 10 as described above is used for a mirror body such as an inner mirror (room mirror) or an outer mirror (door mirror or fender mirror) for rear confirmation in a vehicle, for example, the switch 42 is maintained in an OFF state during the daytime. When the vehicle behind is turning on the headlight at night or the like, the switch 42 is turned on to color the electrochromic film 16 and reduce the reflectance. Thereby, the reflected light of a headlight can be reduced and dazzling falls.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Example 1>
An electrochromic film was formed on an 85 × 114 mm glass substrate as follows. That is, tungsten trioxide (WO ₃ ) was deposited using a commercially available vacuum deposition apparatus, and an electrochromic film 16 made of tungsten trioxide having a thickness of 500 nm was formed on the glass substrate 12.
Next, a first conductive light reflecting film 18 was formed in contact with the electrochromic film 16 obtained above. That is, in the formation of the electrochromic film 16, the first conductive reflective film 18 having a thickness of 100 nm was formed on the electrochromic film 16 using aluminum (Al) instead of tungsten trioxide (WO ₃ ). .
Next, a second conductive reflective film 20 was formed in contact with the first conductive reflective film 18 obtained above. That is, in the formation of the first conductive reflective film 18, a second layer made of chromium having a thickness of 30 nm is formed on the first conductive reflective film 16 by using chromium (Cr) instead of aluminum (Al). A conductive reflective film 20 was formed.
Photoresist is applied to the surface of the second conductive reflective film 20, and a circular pattern corresponding to the through hole 50 having a diameter (D) of 5 μm and a center-to-center distance (L) between adjacent through holes 50 of 10 μm is printed. The photoresist corresponding to the through hole 50 is removed by development, and etching is performed for 100 seconds using an etching solution containing sodium hydroxide, thereby performing the first and second conductive operations. Reflective films 18 and 20 were dissolved. As a result, a through hole 50 having an inner diameter of 5 μm is formed in the second conductive reflective film 20, and the inner diameter of the first conductive reflective film 18 that is easily dissolved by the sodium hydroxide aqueous solution is 5.5 μm (through hole When the inner diameter of 50 is 100, a through hole 48 of 110) is formed.

On the other hand, the same glass substrate as the above-mentioned front side substrate was also adopted as the back side substrate, and a conductive film 28 made of chromium (Cr) having a thickness of 200 nm was formed on the surface by vapor deposition in the same manner as described above.
Next, a carbon electrode film 30 was formed on the conductive film 28 made of chromium. That is, a carbon material composed of 10% by mass of graphite, 10% by mass of carbon black, 70% by mass of activated carbon and 10% by mass of polyimide binder is mixed with an appropriate amount of water, and the obtained mixed material is applied to the substrate surface by a doctor blade method. did. Then, it heated at 180 degreeC for 1 hour, and formed the carbon electrode film 30 about 50 micrometers thick.

A sealing material 32 made of an epoxy resin was applied to the peripheral portion of the surface of the carbon electrode film 30 thus obtained, and an electrolytic solution 34 was applied to the inside to a thickness of about 0.2 mm. As the electrolytic solution according to this example, a solution obtained by adding lithium perchlorate to propylene carbonate, which is an aprotic solvent, to a concentration of 100 mM was used.
Next, the front side substrate 12 including the electrochromic film 16, the first conductive reflective film 18, and the second conductive reflective film 20 is overlaid and sealed with the sealing material 32 to obtain the structure shown in FIG. The electrochromic mirror 10 which has was obtained.
<Comparative Example 1>
In Example 1, first, the first conductive reflective film 18 was formed, then a through hole 48 having an inner diameter of 50 μm was formed using a photomask, and then the second conductive reflective film 20 was formed. For the second conductive reflective film 20, the same operation as in the first conductive reflective film 18 was performed to form a through hole 50 having an inner diameter of 5 μm, in the same manner as in Example 1, An electrochromic mirror of Comparative Example 1 was obtained.

<Example 2>
In Example 1, an electrochromic mirror was obtained in the same manner as in Example 1 except that the metal constituting the second conductive reflective film was changed from chromium to nickel (Ni). When the through hole is formed under the same conditions, the inner diameter of the through hole 50 of the second conductive reflective film is 5 μm, and the inner diameter of the first conductive reflective film is 5.5 μm (the inner diameter of the through hole 50 is When 100, 110) through-holes 48 were formed.
<Comparative example 2>
In Example 2, first, the first conductive reflective film 18 was formed, then a through hole 48 having an inner diameter of 50 μm was formed using a photomask, and then the second conductive reflective film 20 was formed. For the second conductive reflective film 20, the same operation as in the first conductive reflective film 18 was performed to form a through hole 50 having an inner diameter of 5 μm, in the same manner as in Example 1, An electrochromic mirror of Comparative Example 2 was obtained.

<Control Example 1>
In Example 1 and Example 2, an electrochromic mirror of Comparative Example 1 was obtained in the same manner as Example 1 except that the second conductive reflective film was not formed.

<Evaluation>
(Response characteristics)
The response characteristics of the obtained electrochromic mirror were measured. The response characteristic is the time elapsed of colored reflectance (%) after applying a voltage of 1.3 V, and the time of decoloring reflectance (%) after switching the voltage to 0 V (not applied) after 90 seconds. Changes were measured. The results are shown in the graph of FIG. The reflectance is a relative evaluation with 100 before measurement. In Comparative Example 1 in which the second conductive reflective film is not provided, as shown in graph A, good response characteristics are exhibited.
The response characteristic of Comparative Example 1 is shown by a graph B, which is inferior to the response characteristic as compared with the graph A of Control Example 1, but the first conductive reflection film 18 and the second conductive reflection using the same metal. Even in the case of having the membrane 20, it can be seen that in Example 1 in which the inner diameter of the through hole is within the scope of the present invention, it has good response characteristics as shown in the graph B ′.
In Example 2 in which the metal contained in the second conductive reflective film was changed, in Comparative Example 2 in which the inner diameters of the through holes were equal, the response characteristics were inferior as shown in graph C. In Example 2 in which the inside diameter of the present invention is within the range of the present invention, it can be seen that the response characteristics are improved as shown in the graph C ′.
The results are shown in Table 1.

(Discoloration and cloudiness)
About the obtained electrochromic mirror, discoloration and white turbidity of the electrochromic film were evaluated as follows. The results are shown in Table 1.
Connect the 1.3V DC power supply so that the electroreflective film of the obtained electrochromic mirror is the negative electrode and the conductive film is the positive electrode, and repeat the switch ON / OFF 100 times. The film and the conductive reflective film were observed and evaluated according to the following evaluation criteria.
~Evaluation criteria~
○: Discoloration of the electrochromic film was not observed, and white turbidity of the conductive reflective film was not observed after 24 hours.
Δ: Discoloration of the electrochromic film was not observed, but white turbidity of the conductive reflective film was observed after 24 hours.
X: Discoloration of the electrochromic film was observed, and white turbidity of the conductive reflective film was also observed.

  From Table 1, the conductive reflective film using aluminum has a problem in durability. By forming the second conductive reflective film, corrosion is suppressed and the durability is improved. When the metal contained in the conductive reflective film and the metal contained in the second conductive reflective film are the same, the response characteristics are improved by controlling the inner diameter of the through hole to the range defined by the present invention, It can be seen that deterioration of the conductive reflective film can be suppressed while maintaining good response characteristics.

DESCRIPTION OF SYMBOLS 10 Electrochromic mirror 16 Electrochromic film | membrane 18 1st electroconductive reflective film 20 2nd electroconductive reflective film (protective film)
28 Conductive film 30 Carbon film 34 Electrolytic solution 48 50 Through hole

Claims (3)

An electrochromic film colored by a reduction reaction;
A porous metal-containing film that is provided on one side in the thickness direction of the electrochromic film, reflects light transmitted through the electrochromic film, has conductivity, and has holes penetrating in the thickness direction; 1 conductive reflective film;
The first conductive reflective film is provided on one side in the thickness direction opposite to the electrochromic film, penetrates in the thickness direction, and has an inner diameter that is larger than a hole of the first conductive reflective film. A second conductive reflective film that is a porous metal-containing film having small pores;
A conductive film having conductivity provided on the opposite side of the first conductive reflective film in the thickness direction of the second conductive reflective film;
Lithium ions are contained between the protective film and the conductive film, and the lithium ion is applied by applying a voltage with the conductive film being positive and the conductive reflective film or the protective film being negative. Moves to the electrochromic film side, and an electrolytic solution used for the reduction reaction of the electrochromic film,
Electrochromic mirror equipped with.   2. The electrochromic mirror according to claim 1, wherein the metal contained in the second conductive reflective film is a metal that is less susceptible to corrosion than the metal contained in the first conductive reflective film.   When the inner diameter of the hole penetrating in the thickness direction of the second conductive reflective film is 100, the inner diameter of the hole penetrating in the thickness direction of the first conductive reflective film is 104 to 120. The electrochromic mirror according to claim 1 or 2.

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