WO2019199011A1 - Electrochromic film - Google Patents

Abstract

The present application relates to an electrochromic film. An electrochromic film having a predetermined configuration according to one embodiment of the present application has excellent long-term driving durability and provides excellent visibility of changes in optical properties of the film.

Description

Electrochromic film

Citation with Related Applications

This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0040886 dated April 09, 2018 and Korean Patent Application No. 10-2019-0039881 dated April 05, 2019. All content disclosed in the application document is included as part of this specification.

Field of technology

The present application relates to an electrochromic film.

Electrochromic refers to a phenomenon in which the optical properties of an electrochromic active material are changed by an electrochemical oxidation or reduction reaction. The electrochromic active material may change optical properties such as intrinsic color or transmittance, for example, as a result of electron transfer or oxidation / reduction reaction occurring when a voltage is applied from the outside. The electrochromic device using the above phenomenon is largely composed of a working electrode, a counter electrode, and an electrolyte like a battery. In this case, the inorganic-based electrochromic material is generally formed in a film or film form on a transparent conductive electrode such as ITO.

Specifically, when a specific potential is applied to the electrochromic film, ions such as Li ⁺ are inserted into and / or desorbed from the electrochromic material-containing layer in the electrolyte, and at the same time, electrons traveling through an external circuit are also subjected to the electrolysis. The electron density of the electrochromic material changes as it participates in the chemical reaction in the color change material-containing layer, and as a result, the optical properties change as the color of the layer changes. In the state of the optical property change through discoloration, the state in which the light transmittance of the device is lowered is represented as colored, and the state in which the light transmittance of the device is increased is represented as bleached.

As described above, the change in the optical properties of the electrochromic device may be repeated through the change in the polarity of the voltage applied to the electrode. Therefore, even when the repetition of coloring and discoloration, that is, the driving cycle of the device increases, the degree of change in the optical properties of the device needs to be maintained without deterioration.

There is also a need for a discoloration film that allows the user to clearly see the color change of the film without distorting the color change of the discoloring material, in terms of use, aesthetic reasons, or a variety of customer preferences.

One object of the present application is to provide an electrochromic film having excellent driving characteristics, that is, excellent driving durability.

Another object of the present application is to provide an electrochromic film that can be clearly transmitted to a user without distorting the optical property change of the electrochromic material.

The above and other objects of the present application can all be solved by the present application described in detail below.

In one example of the present application, the present application relates to an electrochromic film.

The electrochromic film includes an electrochromic layer, an electrode layer, and a base layer. Specifically, the electrochromic film includes an electrochromic layer, an electrode layer, and a base layer in sequence. The electrochromic layer is a layer containing an electrochromic material capable of changing its intrinsic color by oxidation or reduction.

When coloring and decolorization of the electrochromic layer are repeated while the driving time (or driving cycle) is increased, an acidic or basic environment may be formed inside the electrochromic film. However, not all electrochromic materials have sufficient durability against acidic or basic environments. For example, when some components of the electrolyte salt (eg, Cl, F) are chemically reacted while the device is being driven, and an environment near to acid is formed, electrochromic materials including Ni, Co, or Mn may collapse. have. In addition, the layer comprising the material may also degrade. This may affect the dissolution of the electrode layer, and may cause a problem of peeling of each layer constituting the electrochromic device or the film. As a result, as the driving time increases, there is a problem that the driving durability of the device is drastically lowered.

On the other hand, since the color change that the discoloration material may have is a property inherent in the material, when the color required by the user is specified or the color used in the specific application is limited in terms of the color implemented by the discoloration film, only durability is achieved. It is difficult to select and use only discoloring materials that are known to have excellent durability.

In view of the above problems, the inventors of the present application have led to the development of an electrochromic film having excellent durability while being able to be clearly transmitted to the user without distorting the optical property change caused by the color change material. In this regard, the electrochromic film of the present application includes a protective layer having the characteristics described below in a predetermined position.

The protective layer used in the electrochromic film of the present application may include a metal oxide. More specifically, the protective layer may include at least one of Si oxide (SiO _x ) and Al oxide (AlO _x ). In the present application, the metal oxide means a case containing substantially only a metal component and an oxygen component, and is used in a meaning distinguished from a metal oxynitride. This is because the oxynitride may not satisfy the permeability (transparency) or extinction coefficient described below.

In one example, the protective layer may have a single layer form of Si oxide or a single layer form of Al oxide.

In another example, the protective layer may have a form in which a single layer of Si oxide and a single layer of Al oxide are directly contacted and stacked.

In another example, the protective layer may have a form including Si oxide and Al oxide in one layer.

The oxygen content (atomic%) in Si oxide (SiO _x ) or Al oxide (AlO _x ) included in the protective layer is not particularly limited. For example, the oxide of the protective layer may contain oxygen in a stoichiometrically stable content at a level that satisfies the characteristics described below and at the same time can have adequate adhesion with adjacent layers.

In the present application, the protective layer having the above configuration may be a layer having transparency. Specifically, the protective layer may be a layer having an extinction coefficient (k) of less than 0.1 measured at a wavelength of visible light in the range of 380 to 780 nm. The extinction coefficient k may be calculated as −λ / 4πI (dI / dx). In other words, the extinction coefficient k is a value obtained by multiplying λ / 4π by the reduction ratio dI / I of the light intensity per path unit length dx in the protective layer, for example, 1 m. Where λ is the wavelength of light. The extinction coefficient range may include both the upper limit of the maximum value of the extinction coefficient value measured in the wavelength band less than 0.1 and the case where the arithmetic mean value of the extinction coefficient value measured in each wavelength band is less than 0.1.

The extinction coefficient may also be referred to as an absorption coefficient, and is a factor that defines how strongly the composition absorbs light at a specific wavelength or estimates the transmittance of the protective layer. For example, if the extinction coefficient satisfies the above value, it can be considered transparent. In addition, when the extinction coefficient does not satisfy the above value, for example, exceeds 0.1 or increases to 0.2 or more, the light transmittance may decrease and the light absorbency or reflectivity may become strong. When the reflectivity is increased, the color change of the discoloration material may be distorted, and when the light absorbency is increased, it is difficult to visually recognize the color change of the film. That is, when the protective layer satisfies the extinction coefficient range, the protective layer may have sufficient light transmittance or transparency, and thus the change in the optical properties of the electrochromic layer may be clearly visible to the user without distortion.

In one example, the protective layer may be a layer having an extinction coefficient K _{380 of} less than 0.1 measured at a wavelength of 380 nm.

In one example, the protective layer may be a layer having an extinction coefficient (K ₄₀₀ ) measured at a wavelength of 400 nm less than 0.1.

In one example, the protective layer may be a layer having an extinction coefficient K _{550 of} less than 0.1 measured at a wavelength of 550 nm.

In one example, the protective layer may be a layer having an extinction coefficient K _{780 of} less than 0.1 measured at a wavelength of 780 nm.

In one example, the protective layer may be a layer having an extinction coefficient of "0 (= zero)". For example, the protective layer may be a layer having an extinction coefficient of 0 (= zero) measured in the range of 380 to 780 nm, specifically, in the range of 380 nm, 400 nm, 550 nm, and / or 780 nm. When the extinction coefficient value is "0", it means that the extinction coefficient is substantially zero or close to zero. For example, when the extinction coefficient of the protective layer is 0.01 or less, 0.001 or less, or 0.0001 or less. Can be.

When the protective layer satisfies the extinction coefficient and has light transmittance, a small amount of other components may be included in addition to the Si oxide and the Al oxide. For example, the protective layer may further include an oxide such as In, Ti, or Sn, in addition to Al oxide or Si oxide. In this case, the term "small amount" means that the content of components other than Al oxide (or Si oxide) is 10 wt% or less, 5 wt% or less, 1 wt% or less, 0.1 wt% or less, or 0.01 based on the total weight of the protective layer. It may mean the case that the weight% or less.

In one example, the refractive index (n) of the protective layer satisfying the extinction coefficient may be in the range of 1.50 to 2.50. The refractive index may be a refractive index measured at a visible light wavelength in the range of 380 to 780 nm. The refractive index can be calculated or measured using a known apparatus or method. For example, when the angle of light incident on the surface of the protective layer is θ ₁ , and the refractive angle of light inside the protective layer is θ ₂ , the refractive index value can be confirmed by calculating sin θ ₁ / sin θ ₂ . At this time, the reference plane (or reference line) for measuring θ ₁ and θ ₂ is the same. An electrochromic device including a protective layer that satisfies the range refractive index may have excellent visibility.

In one example, the protective layer may be a layer having a refractive index (n ₃₈₀ ) measured at 380 nm ranging from 1.50 to 2.50.

In one example, the protective layer may be a layer having a refractive index (n ₄₀₀ ) measured at 400 nm in a range of 1.50 to 2.50.

In one example, the protective layer may be a layer having a refractive index (n ₅₅₀ ) measured at 550 nm ranging from 1.50 to 2.50.

In one example, the protective layer may be a layer having a refractive index (n ₇₈₀ ) measured at 780 nm ranging from 1.50 to 2.50.

In one example, the refractive index of the protective layer measured in the wavelength range or each wavelength may be 1.55 or more, 1.60 or more, 1.65 or more, 1.70 or more, 1.75 or more, 1.80 or more, 1.85 or more, 1.90 or more, 1.95 or more, or 2.00 or more. . In addition, the upper limit of the protective layer refractive index is not particularly limited, but may be 2.50 or less, 2.45 or less, 2.40 or less, 2.35 or less, 2.30 or less, 2.25 or less, 2.20 or less, 2.10 or less, or 2.05 or less.

In order to ensure excellent visibility, the refractive index of the protective layer can be appropriately adjusted within the above range.

In one example, the thickness of the protective layer may range from 1 to 120 nm. Specifically, the protective layer is, for example, 5 nm or more, 10 nm or more, 20 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, 60 nm or more , 65 nm or more, 70 nm or more, 75 nm or more, 80 nm or more, 85 nm or more, or 90 nm or more. If the thickness is too thin, the durability of the protective layer may be lowered due to defects such as pin holes. In addition, within the above range, the thickness of the protective layer may be, for example, 115 nm or less, 110 nm or less, 105 nm or less, or 100 nm or less.

The protective layer may be formed using a known dry or wet method. For example, the protective layer may be formed by a dry method such as deposition. Alternatively, a protective layer may be formed using a wet coating method, for example, by applying a heat treatment after coating the Si oxide (and / or Al oxide) -containing coating composition in the form of particles. Given the uniformity of the layer and the extinction coefficient, it may be desirable to use deposition.

Unless stated otherwise, the configuration or properties of the above-described protective layer apply equally to the first to fourth protective layers described below.

In one example, the electrochromic film may include an electrochromic layer 130, an electrode layer 120, the base layer 110 and the first protective layer 210 in sequence (see Figure 1a). When the first protective layer is used in this position, it may be advantageous to protect the electrochromic film from breakage of the base layer and infiltration of foreign materials thereby resulting in improvement of driving durability shown in the following examples. In addition, the change in the optical properties of the electrochromic film can be clearly seen. With this stacking order, adjacent layers may directly contact each other. Alternatively, a third configuration may be interposed between adjacent layers. In order to secure interlayer adhesion and durability, adjacent layers may be preferably in direct contact with each other.

In one example, the electrochromic film may further include a second protective layer 220. Specifically, the electrochromic film may include the electrochromic layer 130, the second protective layer 220, the electrode layer 120, the base layer 110 and the first protective layer 210 in sequence (Fig. 1b). In the prior art, there has been a problem that the electrode layer is peeled from the adjacent layer while the insertion / desorption of electrolyte ions is repeated as the driving cycle increases. However, as in the present application, when the second protective layer is used at a predetermined position, the peeling problem of the electrode layer may be compensated for, and the long-term driving durability of the electrochromic film may be improved. In addition, the change in the optical properties of the electrochromic film can be clearly seen. With this stacking order, adjacent layers may directly contact each other. Alternatively, a third configuration may be interposed between adjacent layers. In order to secure interlayer adhesion and durability, adjacent layers may be preferably in direct contact with each other.

When the electrochromic film includes both the first protective layer and the second protective layer, the first protective layer and the second protective layer may include the same or different oxides.

In one example, the first protective layer and the second protective layer may include an oxide of Si. Alternatively, the first protective layer and the second protective layer may include an oxide of Al.

In another example, the first protective layer may include an oxide of Si, and the second protective layer may include an oxide of Al. Alternatively, the first protective layer may include an oxide of Al, and the second protective layer may include an oxide of Si.

In another example, the first protective layer may be a laminate of a layer containing an oxide of Si and a layer containing an oxide of Al. In addition, the second protective layer may be a laminate of a layer containing an oxide of Si and a layer containing an oxide of Al.

The kind of electrochromic material included in the electrochromic layer 130 is not particularly limited.

In one example, the electrochromic layer may include a reducing discoloration material in which coloring occurs during the reduction reaction. The kind of reducing discoloration material used for the electrochromic layer is not particularly limited. For example, oxides of one or more of Ti, Nb, Mo, Ta, and W may be used as the discoloration material, such as WO ₃ , MoO ₃ , Nb ₂ O ₅ , Ta ₂ O _5, TiO _2, and the like.

In one example, the electrochromic layer may include a material that is different in color development properties from the reducing inorganic color change material. That is, an oxidative discoloration material that is colored when oxidized may be included in the electrochromic layer. The kind of oxidative discoloration material used for the electrochromic layer is not particularly limited. For example, the oxidative discoloration material is selected from Cr, Mn, Fe, Co, Ni, Rh, and Ir, such as LiNiOx, IrO ₂ , NiO, V ₂ O ₅ , LixCoO _{2 ,} Rh ₂ O _3, or CrO _3, and the like. It may be one or more oxides. Alternatively, for example, one or more hydroxides selected from Cr, Mn, Fe, Co, Ni, Rh, and Ir may be used as the oxidative discoloration material of the electrochromic layer. Alternatively, prussian blue may be used as the oxidative discoloration material of the electrochromic layer.

In one example, the electrochromic layer may have a thickness in the range of 50 nm to 450 nm. Specifically, the thickness of the electrochromic layer may be 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, or 350 nm or more. If the thickness is satisfied, it may contain a sufficient amount of electrolyte ions that can be used for electrochromic.

The method of forming the electrochromic layer including the reducing or oxidative discoloring material is not particularly limited. For example, the electrochromic layer can be formed by a dry method such as deposition. Alternatively, the electrochromic layer may be formed by using a wet coating method, for example, by applying an electrochromic material-containing coating composition in the form of particles and then performing heat treatment. Given the uniformity of the layer, it may be desirable to use deposition.

If it has electroconductivity, the material and the shape of an electrode layer which the electrode layer 120 contains are not specifically limited.

In one example, the electrode layer may include a transparent conductive compound. The kind of the transparent conductive compound is not particularly limited, but for example, indium tin oxide (ITO), indium oxide (In ₂ O ₃ ), indium galium oxide (IGO), fluor doped tin oxide (FTO), and aluminum (AZO) doped Zinc Oxide (GZO), Galium doped Zinc Oxide (GZO), Antimony doped Tin Oxide (ATO), Indium doped Zinc Oxide (IZO), Niobium doped Titanium Oxide (NTO), Zinc Oxide (ZnO), or Cesium Tungsten Oxide (CTO) Or the like can be used as the electrode layer forming material.

In another example, the electrode layer may include a metal. In this case, the electrode layer may have a metal mesh shape. Specifically, the electrode layer may include Ag, Cu, Al, Mg, Au, Pt, W, Mo, Ti, Ni, or an alloy thereof, and may have a lattice form. However, it is not limited to the metal materials listed above.

In one example, the electrode layer may have a thickness in the range of 20 nm to 400 nm. Specifically, the electrode layer may have a thickness of, for example, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, or 60 nm or more. In addition, the electrode layer may have a thickness of, for example, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less.

In one example, the electrode layer may have a transmittance in the range of 60 to 95%. In detail, the electrode layer may have a transmittance of 60 to 95% of visible light having a wavelength in a range of 380 nm to 780 nm, more specifically, 400 nm or 550 nm. The transmittance can be measured using a known haze meter (HM).

The base layer 110 serves as a support for the electrochromic film. In order to be used as a support, the substrate layer may include a material capable of providing a predetermined rigidity, for example, glass or a polymer resin.

In one example, the substrate layer may include a polymer resin. Compared to the use of glass, polymer resins have the advantage of providing both rigidity and flexibility at the same time. Specifically, a polyester film such as polycarbonate (PC), poly (ethylene naphthalate) or PEN (polyester ethylene terephthalate), an acrylic film such as PMMA (poly (methyl methacrylate)), or PE (polyethylene) or A polyolefin film such as PP (polypropylene) may be used as the base layer material, but is not limited thereto.

In one example, the substrate layer may have a thickness in the range of 30 nm to 500 μm. Specifically, the thickness of the base layer is, for example, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, 450 nm or more, 500 nm or more, or 1 μm or more. In addition, the upper limit of the thickness of the substrate layer may be, for example, 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 50 μm or less, 10 μm or less, or 5 μm or less.

In one example, the base layer may have a transmittance in the range of 60 to 95%. Specifically, the base layer may have a transmittance of 60 to 95% of visible light having a wavelength in a range of 380 nm to 780 nm, more specifically, 400 nm or 550 nm. The transmittance can be measured using a known haze meter (HM).

In one example, the electrochromic film may further include an electrolyte layer 140, an ion storage layer 150, a counter electrode layer 160, and a counter substrate layer 170 in sequence (see FIG. 1C or 1D). . In this case, the electrolyte layer may be located on one surface opposite to one surface of the electrochromic layer facing one surface of the electrode layer. In the present application, the term "phase" or "phase" as used in connection with the interlayer stacking position is not only used when a certain structure is formed directly above another structure (but adjacent components are in contact), It means to include until the configuration of the interposition. In order to secure interlayer adhesion and durability, adjacent layers may be preferably in direct contact with each other.

The electrolyte layer 140 is configured to provide electrolyte ions involved in the electrochromic reaction. The electrolyte ion may be, for example, a monovalent cation such as H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , or Cs ⁺ .

The type of electrolyte in the present application is not particularly limited. For example, liquid electrolytes, gel polymer electrolytes or inorganic solid electrolytes can be used without limitation. In addition, the electrolyte may be used in the form of one layer or film to be laminated together with the electrode layer or the light transmitting film.

The type of electrolyte salt used in the electrolyte layer is not particularly limited, as long as it can include a compound capable of providing a monovalent cation, that is, H ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , or Cs ⁺ . For example, the electrolyte layer is LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiCl, LiBr, LiI, LiB ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , Lithium salt compounds such as CH ₃ SO ₃ Li, CF ₃ SO ₃ Li, or (CF ₃ SO ₂ ) ₂ NLi; Or sodium salt compounds such as NaClO ₄ .

In one example, the electrolyte layer may comprise a Cl or F element containing compound as the electrolyte salt. Specifically, the electrolyte layer is LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiCl, LiB ₁₀ Cl ₁₀ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , CF ₃ SO ₃ Li And (CF ₃ SO ₂ ) ₂ NLi and NaClO ₄ . Such electrolyte salts can create harsh conditions (eg, acidic conditions) during operation. However, in the present application, since a protective layer having a predetermined configuration is used, deterioration of the electrochromic material generated under acidic conditions can be suppressed.

In one example, the electrolyte may further include a carbonate compound as a solvent. Since a carbonate type compound has high dielectric constant, ionic conductivity can be improved. As a non-limiting example, a solvent such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), or ethylmethyl carbonate (EMC) may be used as the carbonate-based compound.

In another example, when the electrolyte layer comprises a gel polymer electrolyte, the electrolyte layer may be poly-vinyl sulfonic acid, poly-styrene sulfonic acid, poly-ethylene sulfonic acid (Poly-ethylene sulfonic acid), poly-2-acrylamido-2methyl-propane sulfonic acid, poly-perfluoro sulfonic acid, poly -Toluene sulfonic acid, poly-vinyl alcohol, poly-ethylene imine, poly-vinyl pyrrolidone, poly-ethylene oxide ( Poly-ethylene oxide (PEO)), poly-propylene oxide (PPO), poly- (ethylene oxide, siloxane) (PEOS), poly- (ethylene glycol, Siloxane) (poly- (ethylene glycol, siloxane)), poly- (propylene oxide, siloxane) (poly- (propylene oxide, siloxane), poly- (ethylene oxide, methyl acid), poly- (ethylene oxide, methyl methacrylate) (PEO-PMMA), poly- (ethylene oxide, acrylic acid) (PEO-PAA)), poly- (propylene glycol, methyl methacrylate) (PPG-PMMA), poly-ethylene succinate or poly-ethylene It may include a polymer such as adipate (poly-ethylene adipate). In one example, a mixture or two or more copolymers of the above listed polymers may be used as the polymer electrolyte.

Although not particularly limited, the thickness of the electrolyte layer may range from 10 μm to 200 μm.

In one example, the electrolyte layer may have a transmittance in the range of 60 to 95%. Specifically, the electrolyte layer may have a transmittance of 60 to 95% of visible light having a wavelength range of 380 nm to 780 nm, more specifically, 400 nm wavelength or 550 nm wavelength. The transmittance can be measured using a known haze meter (HM).

The ion storage layer 150 is a layer formed to balance the charge balance with the electrochromic layer during the reversible oxidation / reduction reaction for discoloration of the electrochromic material.

In one example, the ion storage layer may include an electrochromic material different in color development properties from the electrochromic material used in the electrochromic layer. For example, when the electrochromic layer includes a reducing color change material, the ion storage layer may include an oxidative color change material. And vice versa. As such, when the ion storage layer and the electrochromic layer use materials having different color development characteristics, that is, mutually complementary color change (reaction) materials, it may be advantageous to balance charge.

In one example, when the electrochromic layer includes a reducing color change material, the ion storage layer may include a color change material derived from Ni, Co, and / or Mn. Since the electrochromic film of the present application includes the protective layer, even when an oxide or hydroxide of Ni, Co, and / or Mn, which is known to be poor in long term driving durability under acidic conditions, is used as a discoloring material, It can provide excellent visibility.

In one example, when the electrochromic layer includes a reducing discoloration material, the ion storage layer may include one or more oxides selected from Ni, Co, and Mn as the oxidative discoloration material.

In another example, when the electrochromic layer includes a reducing discoloring material, the ion storage layer may include one or more hydroxides selected from Ni, Co, and Mn as the oxidative discoloring material.

In another example, when the electrochromic layer includes a reducing color change material, the ion storage layer may include at least one oxide selected from Ni, Co, and Mn; And one or more hydroxides selected from Ni, Co, and Mn.

In one example, the thickness of the ion storage layer may range from 50 to 500 nm. Specifically, the ion storage layer is 60 nm or more, 70 nm or more, 80 nm or more, 90 nm or more, 100 nm or more, 110 nm or more, 120 nm or more, 130 nm or more, 140 nm or more, 150 nm or more, 160 nm At least 170 nm, at least 180 nm, at least 190 nm, or at least 200 nm. If the thickness is satisfied, it may be advantageous to contain a sufficient amount of electrolyte ions that can be used for the electrochromic reaction and to balance the charge with the electrochromic layer. The upper limit of the thickness of the ion storage layer may be, for example, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, or 250 nm or less.

The characteristics and configurations of the counter electrode layer 160 and the counter substrate layer 170 may be the same as those of the electrode layer 120 and the substrate layer 110 described above.

In one example, the electrochromic film may further include a third protective layer on one surface opposite to one surface of the counter substrate layer facing the counter electrode layer. That is, the electrochromic film may sequentially include an ion storage layer 150, a counter electrode layer 160, a counter substrate layer 170, and a third protective layer 230 (see FIG. 1E).

With this stacking order, adjacent layers may directly contact each other. Alternatively, a third configuration may be interposed between adjacent layers. In order to secure interlayer adhesion and durability, adjacent layers may be preferably in direct contact with each other.

The configuration or characteristics associated with the third protective layer may be the same as that of the above-described protective layer (eg, the first protective layer).

In another example, the electrochromic film may further include a fourth protective layer between the ion storage layer and the counter electrode layer. In detail, the electrochromic film may include an ion storage layer 150, a fourth protective layer 240, a counter electrode layer 160, a counter substrate layer 170, and a third protective layer 230. (See FIG. 1F).

With this stacking order, adjacent layers may directly contact each other. Alternatively, a third configuration may be interposed between adjacent layers. In order to secure interlayer adhesion and durability, adjacent layers may be preferably in direct contact with each other.

The configuration or characteristics associated with the fourth protective layer may be the same as that of the above-described protective layer (eg, the second protective layer).

When the electrochromic film includes both the third protective layer and the fourth protective layer, the third protective layer and the fourth protective layer may include the same or different oxides.

In one example, the third protective layer and the fourth protective layer may include an oxide of Si. Alternatively, the third protective layer and the fourth protective layer may include an oxide of Al.

In another example, the third protective layer may include an oxide of Si, and the fourth protective layer may include an oxide of Al. Alternatively, the third protective layer may include an oxide of Al, and the fourth protective layer may include an oxide of Si.

In another example, the third protective layer may be a laminate of an oxide layer of Si and an oxide layer of Al. Further, the fourth protective layer may be a laminate of an oxide layer of Si and an oxide layer of Al.

When the electrochromic film includes all of the first to fourth protective layers, these protective layers may include the same or different oxides. For example, the first protective layer and the second protective layer may include the same oxide, and the third protective layer and the fourth protective layer may include the same oxide. Alternatively, the first protective layer and the third protective layer may include the same oxide, and the second protective layer and the fourth protective layer may include the same oxide. Alternatively, the first protective layer and the fourth protective layer may include the same oxide, and the second protective layer and the third protective layer may include the same oxide.

The electrochromic film may further include a power source. The method of electrically connecting the power source to the electrochromic film is not particularly limited and may be appropriately made by those skilled in the art.

In one example, the power source may apply a voltage of 2.0 V or less, or 1.5 V or less to the film. That is, when driving the electrochromic film having the above configuration, a voltage in the range of -2.0 to +2.0 V or a voltage in the range of -1.5 to +1.5 V may be applied. Depending on the polarity change of the applied voltage, the electrochromic film may alternately have a colored and a discolored state. For example, when the electrochromic layer includes a reducing color change material, the coloring voltage applied to the electrochromic layer may be negative polarity, and conversely, the color fading voltage may be positive polarity. The voltage which brings about coloring of a film can be called coloring voltage, and the voltage which brings about decolorization of a film can be called decoloring voltage.

In one example, the voltage applied by the power source may be a constant voltage. For example, the voltage may alternately apply voltages of -2.0 V and +2.0 V, or voltages of -1.5 V and +1.5 V to the electrochromic film.

In one example, the time for which the decolorization voltage is applied and the time for applying the coloring voltage may be 60 seconds (s) or less, respectively. For example, the time for which each voltage is applied may be 60 seconds, 50 seconds, 40 seconds or 30 seconds. In this regard, for example, assuming that each voltage is applied for 60 seconds, one cycle of discoloration and one coloration process according to the polarity change of the applied voltage is 1 cycle. The period of the cycle may be 120 seconds, which is the sum of 60 seconds of applying the coloring voltage and 60 seconds of applying the discoloring voltage.

In one example, a difference between the electrochromic film during transmission and discoloration when coloring transmittance _{(△ T = T bleached - T} colored, wherein, T _bleached is the transmittance when the electrochromic film discoloration, T _colored is when the electrochromic film colored Transmittance) can be at least 45%, at least 50%, at least 55% or at least 60%. The transmittance can be measured using known apparatus and methods. For example, known devices such as Solidspec 3700 or ellipsometers can be used to measure the transmittance of electrochromic films.

As described above, the electrochromic film including the protective layer may have excellent driving durability. For example, the electrochromic film may be a film that satisfies 45% or more of the difference (ΔT _1000'th ) of the transmittance at the time of coloration and the transmittance at the time of discoloration even after 1,000 cycles have elapsed.

In one example, the electrochromic film may be a film satisfying 90% or more or 95% or more of a driving capacity or a cycle capacity calculated by the following equation.

[expression]

Drive capacity (%) = {(△ T _1000'th ) / (△ T _1'st )} x 100

In the above formula, ΔT _1'st is the difference in transmittance between the color transmittance and the decolorization transmittance of the electrochromic film during the first cycle driving, and ΔT _1000'th means the difference in transmittance between the color transmittance and the decolorization transmission during the thousandth cycle driving. . In this case, the voltage applied during driving may be 1.5 V or less, and each time of applying the coloring voltage and the decolorizing voltage forming one cycle may be 60 seconds or less.

As described above, since the protective film of the present application including the protective layer can suppress deterioration due to decomposition or dissolution of the layer constituting the electrochromic film, a reduction ratio of ΔT _1000'th to ΔT _1'st This 10% or less can be satisfied. That is, according to the present application, an electrochromic film having excellent long term driving durability is provided.

In one example of the present application, the present application relates to a method of manufacturing an electrochromic film.

The method may include forming a first protective layer on one surface of the substrate layer, and sequentially forming an electrode layer and an electrochromic layer on the other surface of the substrate layer. The first protective layer includes at least one of Si oxide and Al oxide, and other materials included in each of the electrode layer, the electrochromic layer, and the base layer are the same as those described above with respect to the electrochromic film.

In one example, the method of forming the first protective layer on the substrate layer may be deposition. Specifically, the first protective layer may be formed by sputter deposition.

With regard to sputtering, the conditions for forming a stable thin film are not particularly limited, but for example, the sputtering deposition for forming the protective layer may be performed under a process pressure within a range of 5 to 40 mTorr and a power condition within a range of 50 to 350 W. It may be made while flowing oxygen (O ₂ ) at a predetermined flow rate.

In one example, sputtering deposition for forming the first protective layer may be performed while adjusting the flow rate of the gas to a predetermined range. Specifically, the sputtering deposition may be performed by flowing oxygen (O ₂ ) in a vacuum state and generating an argon (Ar) plasma to a metal target (Si or Al) to form a protective layer on the base layer. At this time, the flow rate of oxygen and argon or the ratio between them may be adjusted.

In one example, sputtering deposition for forming the first protective layer may be performed under a condition that the flow rate of oxygen (O ₂ ) is 5.0 sccm or more. When the flow rate of oxygen is less than the above range, the value of the extinction coefficient may exceed 0.1. For example, when the oxygen flow rate is not satisfied, the protective layer is less likely to have an extinction coefficient value of less than 0.1 at a wavelength in the range of 380 to 780 nm, specifically at a wavelength of 400 nm or 550 nm.

Specifically, the flow rate of oxygen (O ₂ ) injected into the space where the sputtering process is performed is at least 5.5 sccm, at least 6.0 sccm, at least 6.5 sccm, at least 7.0 sccm, at least 7.5 sccm, at least 8.0 sccm, at least 8.5 sccm, at least 9.0 sccm. , At least 9.5 sccm or at least 10.0 sccm. The upper limit of the flow rate is not particularly limited, but may be, for example, 20 sccm or less or 15 sccm or less.

In one example, the ratio of the injection flow rate of oxygen (O ₂ ) and argon (Ar) during the sputtering deposition for forming the first protective layer may be adjusted. Specifically, assuming that the flow rates of argon (Ar) and oxygen (O ₂ ) injected into the space where the sputtering process is performed are flow rates of A sccm and B sccm, these flow rate ratios A (Ar) / B (O ₂ ) are And may be maintained in the range of 1.5 to 7. Specifically, the flow rate ratio A (Ar) / B (O ₂ ) may be 1.6 or more, 1.7 or more or 1.8 or more, the upper limit is, for example, 6.5 or less, 6.4 or less, 6.3 or less, 6.2 or less, 6.1 or less, 6.0 or less, 5.9 or less, 5.8 or less, or 5.7 or less.

In one example, the method of forming the electrode layer is not particularly limited. For example, when the electrode layer includes a transparent conductive oxide, the electrode layer may be formed on the base layer by a deposition method. Alternatively, when the electrode layer includes a metal, the electrode layer may be formed on the base layer through thermocompression bonding to a metal film or a metal mesh electrode manufactured separately. Alternatively, the electrode layer may be formed through a predetermined etching (etching) after the metal thin film is formed.

In one example, the electrochromic layer may be formed by deposition. For example, sputter deposition can be used. The deposition conditions are not particularly limited and may be made while controlling the process conditions according to the type of electrochromic material used.

In one example, the method includes forming a first protective layer on one surface of the substrate layer, and sequentially forming an electrode layer, a second protective layer, and an electrochromic layer on the other surface of the substrate layer. It may include. The second protective layer may be formed in the same manner as the first protective layer described above.

The laminate formed by the above-described method (first protective layer / substrate layer / electrode layer / electrochromic layer or first protective layer / substrate layer / electrode layer / second protective layer / electrochromic layer) may be referred to as an upper laminate. have.

In one example, the method may further comprise manufacturing a lower laminate. For example, the lower laminate may have a stacked structure of a third protective layer / relative base layer / relative electrode layer / ion storage layer. Alternatively, the lower laminate may have, for example, a laminated structure of a third protective layer / relative base layer / relative electrode layer / fourth protective layer / ion storage layer.

In one example, the method may include forming a third protective layer on one surface of the counter substrate layer, and sequentially forming the counter electrode layer and the ion storage layer on the other surface of the counter substrate layer. have.

In one example, the method includes forming a third protective layer on one surface of the counter substrate layer, and sequentially forming a counter electrode layer, a fourth protective layer, and an ion storage layer on the other surface of the counter substrate layer. It may include the step.

The method of forming the third protective layer or the fourth protective layer included in the lower laminate may be the same as that of the first protective layer described above. In addition, the material included in each of the counter electrode layer, the ion storage layer, and the counter substrate layer, and a method of forming them may also be the same as described above.

In one example, the method may further include bonding the upper stack and the lower stack through the electrolyte layer. The bonding method may be made through, for example, known lamination and the like, and is not particularly limited. The material included in the electrolyte layer is the same as described above with respect to the electrochromic film.

According to an example of the present application, the user can clearly recognize the change in the optical characteristics, an electrochromic film excellent in driving durability can be provided.

1 schematically illustrates the structure of an electrochromic film including a protective layer according to an example of the present application.

FIG. 2 is a graph showing the extinction coefficient k and the refractive index n of the protective layers of Preparation Examples 1 to 3. FIG. The extinction coefficient k showing all zero values (consistent with the horizontal axis of the graph) in all three preparation examples is not shown in FIG. 2. In FIG. 2, the curves drawn relate to Preparation Example 3 (93.8 nm thickness), Preparation Example 2 (62.4 nm thickness), and Preparation Example 1 (36.0 nm thickness) in order from the top.

3 is a graph showing driving durability evaluation results associated with Examples and Comparative Examples.

Meaning in the drawings means as follows.

110: substrate layer

120: electrode layer

130: electrochromic layer

140: electrolyte layer

150: ion storage layer

160: counter electrode layer

170: counter substrate layer

210: first protective layer

220: second protective layer

230: third protective layer

240: fourth protective layer

Hereinafter, the present application will be described in detail through examples. However, the protection scope of the present application is not limited by the examples described below.

Experimental Example 1: Comparison of the extinction coefficient and refractive index of the protective layer

Preparation Examples 1 to 3

On the silicon wafer, a silicon oxide layer (SiOx layer) about 36 nm thick was formed. Specifically, the silicon oxide layer was formed through sputter deposition while flowing oxygen at a process pressure of about 20 mTorr and about 200 W power. At this time, the flow rate of oxygen was maintained at about 5.5 sccm, and the injection flow rate ratio (Ar / O ₂ ) of oxygen and argon was maintained at about 6.

Further, under the same conditions, deposition time was increased to form silicon oxide layers of about 62.4 nm and about 93.8 nm thickness on two different silicon wafers.

Preparation Example 4

A silicon oxide layer having a thickness of about 50 nm was prepared in the same manner, except that the flow rate of oxygen was adjusted to 3 sccm and the flow rate ratio of oxygen and argon (Ar / O ₂ ) was about 11 when forming the silicon oxide layer. Formed.

Refractive index and extinction coefficient values of the silicon oxide layers of Preparation Examples 1 to 4 were measured using an ellipsometer. The results are shown in Table 1 below.

	Thickness (nm)	Refractive Index (n 380 )	Refractive Index (n 780 )	Extinction coefficient (K 400 )	Extinction coefficient (K 550 )
Preparation Example 1	36	2.04	1.85	0	0
Preparation Example 2	62.4	2.23	1.93	0	0
Preparation Example 3	93.8	2.44	1.95	0	0
Preparation Example 4	50	2.35	3.21	1.2	1.3

Experimental Example 2: Comparison of Permeability and Driving Durability

Example 1

Preparation of the upper laminate (WO3 / ITO / PET / AlOx) : An aluminum oxide layer (AlOx, about 15 nm thick) was formed on one surface of the PET substrate, and ITO on the opposite surface of the PET substrate on which the aluminum oxide was formed. A layer (thickness about 50 nm) and a tungsten oxide layer (WO 3, thickness about 360 nm) were formed in sequence. The aluminum oxide layer was formed in the same manner as in Production Example 1 except that the target metal and the base layer were different.

Preparation of the lower laminate (NiOx / ITO / PET / AlOx): forming the other of the PET base material nickel oxide layer formed on one surface (NiOx, about 200 nm thick) and an ITO layer (about 50 nm thick), and the opposite of PET An aluminum oxide layer (AlOx, about 15 nm thick) was formed on one surface. The aluminum oxide layer was formed in the same manner as in Production Example 1 except that the target metal and the base layer were different.

Preparation of electrochromic film : An electrochromic film (AlOx / PET / ITO / NiOx / electrolyte layer / WO ₃ / ITO / PET / AlOx) was prepared by bonding an upper laminate and a lower laminate through an electrolyte layer. At this time, an electrolyte layer containing propylene carbonate (PC) and LiClO ₄ (1M) was used.

Examples 2 to 4 and Comparative Example 1

As shown in Table 2, an electrochromic film was prepared in the same manner as in Example 1, except that the protective layer material, the stacking order, and the presence or absence of the protective layer were different. The thickness of the silicon oxide (SiOx) layer was about 10 nm.

For the electrochromic films of the examples and the comparative examples, the transmittance was specified while alternately applying voltages of -1.5 V and +1.5 V at 60 second intervals, respectively. When the coloration and decolorization are performed once, each cycle is stabilized by driving about 10 cycles from the initial voltage application, and the change in the coloration and decolorization transmittance difference according to the increase in the number of cycles from subsequent cycles Was measured (see FIG. 3). And, as shown in Table 2, the difference in coloration and decolorization transmittance (ΔT _1'st ) of the first cycle after stabilization and the difference in coloration and decolorization transmittance (ΔT _1000'th ) of the thousandth cycle was recorded. The transmittance was measured using a haze meter (solidspec 3700).

	Top stack	Bottom stack	△ T 1'st	△ T 1000'th	* CycleCapacity
Example 1	WO 3 / ITO / PET / AlOx	NiOx / ITO / PET / AlOx	60	59	98
Example 2	WO 3 / ITO / PET / SiOx	NiOx / ITO / PET / SiOx	60	58	97
Example 3	WO 3 / SiOx / ITO / PET / SiOx	NiOx / SiOx / ITO / PET / SiOx	53	52	98
Example 4	WO 3 / AlOx / ITO / PET / AlOx	NiOx / AlOx / ITO / PET / AlOx	52	50	96
Comparative Example 1	WO 3 / ITO / PET	NiOx / ITO / PET	60	23	38
* Cycle capacity (%) = (△ T 1000'th / △ T 1'st ) * 100

Claims (15)

1. Electrochromic layer; An electrode layer; Base layer; And a first protective layer sequentially;

   The first protective layer is an electrochromic film comprising at least one of an oxide of Si and an oxide of Al.
2. The method of claim 1, further comprising a second protective layer comprising at least one of an oxide of Si and an oxide of Al,

   The electrochromic layer; A second protective layer; An electrode layer; Base layer; And an electrochromic film sequentially comprising a first protective layer.
3. The electrochromic film of claim 2, wherein the first protective layer and the second protective layer have an extinction coefficient of less than 0.1 measured at a wavelength of 380 nm to 780 nm.
4. The electrochromic film of claim 2, wherein the first protective layer and the second protective layer include the same or different oxides.
5. The method of claim 1, wherein the electrochromic layer comprises one of a reducing color change material and an oxidative color change material,

   The reducing discoloration material is at least one oxide selected from the group consisting of Ti, Nb, Mo, Ta and W,

   The oxidative discoloration material may include at least one oxide selected from the group consisting of Cr, Mn, Fe, Co, Ni, Rh, and Ir; At least one hydroxide selected from the group consisting of Cr, Mn, Fe, Co, Ni, Rh, and Ir; And an electrochromic film selected from Prussian blue.
6. The method of claim 5, wherein the electrolyte layer on the opposite side of one surface of the electrochromic layer facing one surface of the electrode layer; Ion storage layer; Counter electrode layer; And a counter substrate layer in sequence,

   The ion storage layer is an electrochromic film comprising a color change material that is different from the electrochromic layer color development properties.
7. The electrochromic film of claim 6, wherein the electrolyte layer includes an electrolyte salt that provides a monovalent cation, and the electrolyte salt includes an F or Cl element.
8. The electrochromic film of claim 7, wherein the ion storage layer comprises at least one oxide or hydroxide selected from Ni, Co, and Mn.
9. The electrochromic method of claim 6, further comprising a third passivation layer on one surface of the counter substrate layer facing the counter electrode layer, wherein the third passivation layer includes at least one of an oxide of Si and an oxide of Al. film.
10. The electrochromic film of claim 9, further comprising a fourth protective layer between the ion storage layer and the counter electrode layer, wherein the fourth protective layer includes at least one of an oxide of Si and an oxide of Al.
11. The electrochromic film of claim 10, wherein the third and fourth protective layers have an extinction coefficient of less than 0.1, measured at a wavelength of 380 to 780 nm.
12. The electrochromic film of claim 10, wherein the third protective layer and the fourth protective layer comprise the same or different oxides.
13. The electrochromic film of claim 3 or 11, wherein the first to fourth protective layers have a thickness in the range of 10 to 120 nm, and have a refractive index in the range of 1.50 to 2.50 for a wavelength in the range of 380 to 780 nm. .
14. The electrochromic film according to claim 1 or 6, wherein at least one of the electrode layer and the counter electrode layer contains a transparent conductive compound or a metal.
15. The electrochromic film of claim 1, wherein a cycle capacity calculated by the following formula satisfies 90% or more:

    [expression]

    Drive capacity (%) = {(△ T _1000'th ) / (△ T _1'st )} x 100

    ( _Wherein ΔT _1'st is the difference between the color transmittance and the decolorization transmittance of the electrochromic film during the first cycle driving, and ΔT _1000'th means the difference between the color transmittance and the decolorization transmittance during the thousandth cycle driving, The voltage applied during driving is 1.5 V or less, and each application time of the coloring voltage and the decolorizing voltage is 60 seconds or less.)

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