JP6985184B2 - Transparent conductive film and light control film for light control film - Google Patents

Description

The present invention relates to a transparent conductive film used for a light control film. The present invention also relates to a dimming film using the transparent conductive film.

A dimming material or the like is used for a dimming film or the like. The dimming material is used for the purpose of adjusting the transmittance or adjusting the color tone by blocking light of a specific wavelength. Dimming films are used in various fields such as interior members, building members and electronic parts.

The light control film has, for example, a structure in which a light control layer is arranged between two transparent conductive films. The transparent conductive film used for the light control film has a base film and a conductive layer on the surface of the base film. In the light control film, the conductive layers are in a state of facing each other via the light control layer. In the light control film, an electric field is applied between the conductive layers of the two transparent conductive films. The amount of light passing through the dimming film can be changed depending on whether an electric field is applied or not.

An example of a transparent conductive film used for the light control film is disclosed in Patent Document 1 below. In the transparent conductive film described in Patent Document 1, the conductive layer may be formed of ITO or the like.

WO2008 / 075772A1

In the light control film, in a method called PDLC (Polymer Dispersed Liquid Crystal), the light control layer is often formed by using a liquid crystal layer and an acrylic resin as a binder resin. The conductive layer in contact with the light control layer formed by using the acrylic resin is exposed to acidic conditions by acrylic acid or the like contained in a trace amount due to the acrylic resin. In addition, the conductive layer may be exposed to acidic conditions due to external factors other than the dimming layer.

In the conventional transparent conductive film as described in Patent Document 1, the acid resistance of the conductive layer is low, and the resistance value may increase. As a result, the dimming performance of the dimming film may deteriorate.

An object of the present invention is to provide a transparent conductive film for a light control film capable of increasing the acid resistance of the conductive layer and suppressing a change in the resistance value of the conductive layer exposed to acidic conditions. Another object of the present invention is to provide a light control film using the transparent conductive film for a light control film.

According to a broad aspect of the present invention, the transparent conductive film used for a light control film, which has a base film and a conductive layer arranged on one surface side of the base film, is said to be conductive. The layer is an indium tin oxide oxide layer, and in TOF-SIMS analysis, the ^{ratio of the intensity of InOH-} ions in the central portion in the thickness direction of the conductive layer to the total intensity of all negative ions is 0.0005 or less. , A transparent conductive film for a light control film is provided.

In certain aspects of the transparent conductive film for the light control film according to the present invention, in the TOF-SIMS analysis, the strength of the H ₃ O ⁺ ions at the surface opposite from said substrate film side of the conductive layer In ⁺ ions The ratio of to the strength of is 0.05 or less.

In a specific aspect of the transparent conductive film for a light control film according to the present invention, the surface resistance value of the conductive layer is 150 Ω / □ or less.

In a specific aspect of the transparent conductive film for a light control film according to the present invention, the total light transmittance at a wavelength of 550 nm is 88% or more, and the haze value is 1.3% or less.

In a specific aspect of the transparent conductive film for a light control film according to the present invention, the transparent conductive film for a light control film is used so that the conductive layer comes into contact with the light control layer containing an acrylic resin.

According to a broad aspect of the present invention, a dimming layer arranged between a first transparent conductive film, a second transparent conductive film, and the first transparent conductive film and the second transparent conductive film. A light control film is provided in which at least one of the first transparent conductive film and the second transparent conductive film is the above-mentioned transparent conductive film for a light control film.

In certain aspects of the light control film according to the present invention, the light control layer contains an acrylic resin.

The transparent conductive film for a light control film according to the present invention is a transparent conductive film used for a light control film, and has a base film and a conductive layer arranged on one surface side of the base film. The conductive layer is an indium tin oxide oxide layer. In the transparent conductive film for a light control film according to the present invention, in the TOF-SIMS analysis, the ^{ratio of the intensity of InOH-} ions in the central portion in the thickness direction of the conductive layer to the total intensity of all negative ions is 0.0005 or less. Is. Since the transparent conductive film for a light control film according to the present invention has the above configuration, the acid resistance of the conductive layer is enhanced to suppress the change in the resistance value of the conductive layer exposed to acidic conditions. Can be done.

FIG. 1 is a cross-sectional view showing a transparent conductive film for a light control film according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of a light control film using the transparent conductive film for light control film shown in FIG.

Hereinafter, the details of the present invention will be described.

The transparent conductive film for a light control film according to the present invention (hereinafter, may be referred to as a transparent conductive film) is used as a light control film. The transparent conductive film is transparent. Transparency also includes translucency. The transparent conductive film has, for example, light transmission. The fact that the transparent conductive film has light transmittance means that, for example, the total light transmittance at a wavelength of 550 nm is preferably 88% or more, more preferably 89% or more.

The transparent conductive film according to the present invention includes a base film and a conductive layer. The conductive layer is arranged on one surface side of the base film.

In the transparent conductive film according to the present invention, the conductive layer is an indium tin oxide oxide layer (ITO layer).

In the transparent conductive film according to the present invention, in the TOF-SIMS analysis, the ^{ratio of the strength of InOH-} ions in the central portion in the thickness direction of the conductive layer to the total strength of all negative ions (InOH ^- ion strength / total minus). The total ionic strength) is 0.0005 or less. The surface of the conductive layer opposite to the base film side is the surface on the side where the dimming layer is arranged. The surface of the conductive layer opposite to the base film side is, for example, the surface on the side in contact with the dimming layer.

Since the transparent conductive film according to the present invention has the above configuration, the conductive layer has high acid resistance, and changes in the resistance value (sheet resistance value) of the conductive layer exposed to acidic conditions can be suppressed. Can be done. As a result, deterioration of the dimming performance of the dimming film can be suppressed.

In order to suppress the change in the resistance value of the conductive layer exposed to acidic conditions, the above-mentioned strength ratio of the central portion in the thickness direction of the conductive layer, not the surface opposite to the base film side of the conductive layer, is used. It was found that it needed to be controlled. This is because even if the surface of the conductive layer exposed to acidic conditions deteriorates, the deterioration is effectively suppressed inside the conductive layer (the region including the central portion), so that the deterioration of the conductive layer as a whole is suppressed. It is thought that this is because it can be done.

In the TOF-SIMS analysis, the strength ratio in the central portion of the conductive layer in the thickness direction is measured as follows.

C60 sputtering is continuously performed at the same point on the surface of the conductive layer opposite to the base film side. If the ^{number of In +} ion detections is less than the number of Si ⁺ ions detected and the number of spatters is odd, the number of In ⁺ ions detected is the center of the number of spatters that is less than the ^{number of Si + ions detected.} From the measurement results at the (half) number of times, the strength ratio in the central portion in the thickness direction of the conductive layer is obtained. In ⁺ when sputtering the number of times the number of detection becomes less than the number of detected Si ⁺ ions of the ion is even, the center of the sputter number of detected number of In ⁺ ions becomes less than the number of detected Si ⁺ ions From the average value of the measurement results at the two times of the above, the strength ratio in the central portion in the thickness direction of the conductive layer is obtained.

^{In the TOF-SIMS analysis, the ratio of the intensity of InOH-} ions to the total intensity of all negative ions in the central portion in the thickness direction of the conductive layer is determined. From the viewpoint of further increasing the acid resistance of the conductive layer, the above ratio (total of InOH ⁻ ion strength / total negative ion strength) is preferably 0.0004 or less, more preferably 0.0003 or less, still more preferably. It is 0.0002 or less, particularly preferably 0.0001 or less. The above ratio (total of InOH ⁻ ion intensity / total negative ion intensity) is usually 0 or more.

_{In TOF-SIMS analysis, the ratio of H 3} O ⁺ ionic strength to In ⁺ ionic strength on the surface of the conductive layer opposite to the base film side _{(H 3} O ⁺ ionic strength / In ⁺ ionic strength). ). The acid resistance of the conductive layer from the viewpoint of further enhancing the _(intensity of strength / an In ⁺ ions H 3 ^{O +} ions) the ratio is preferably 0.05 or less, more preferably 0.04 or less, more preferably 0 It is 0.03 or less, particularly preferably 0.02 or less. The above ratio (H ₃ O ⁺ ionic strength / In ⁺ ionic strength) is usually 0 or more.

In the TOF-SIMS analysis, the strength ratio of the conductive layer on the surface opposite to the base film side is obtained from the measurement result in the first sputtering.

As a method of controlling the strength ratio within the above range, a method of controlling the total pressure at the time of sputtering when the conductive layer is formed by sputtering, and a method of controlling the water pressure at the time of sputtering when the conductive layer is formed by sputtering. , And a method of controlling the film forming roll (can roll) temperature at the time of RtR sputtering. The total pressure at the time of spatter can be generally controlled by adjusting the volume of the vacuum part of the apparatus, the displacement of the vacuum pump, the flow rate of gas such as Ar introduced to generate plasma, and the like. Further, the water pressure at the time of sputtering is adjusted by adjusting the vacuum holding time until the start of sputtering film formation, the pre-drying treatment method of the base film, the flow rate of gas such as Ar introduced to generate plasma, and the like. Can be controlled. Further, the temperature of the film-forming roll at the time of RtR sputtering can be controlled by adjusting the temperature of the refrigerant circulated in the film-forming roll.

The transparent conductive film is preferably used so that the conductive layer is in contact with the light control layer containing the acrylic resin. In the present invention, even if the conductive layer comes into contact with the dimming layer containing the acrylic resin, the change in the resistance value of the conductive layer can be suppressed. In the present invention, even if the conductive layer is in contact with the dimming layer that does not contain the acrylic resin, the change in the resistance value of the conductive layer can be suppressed.

The transparent conductive film is preferably an annealed transparent conductive film.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a transparent conductive film for a light control film according to an embodiment of the present invention.

The transparent conductive film 1 shown in FIG. 1 is used as a light control film.

The transparent conductive film 1 includes a base film 11 and a conductive layer 12.

The base film 11 has light transmission. The base film 11 is made of a light-transmitting material. The base film 11 has a first surface 11a and a second surface 11b. The first surface 11a and the second surface 11b face each other.

The conductive layer 12 is arranged on the first surface 11a side of the base film 11. The conductive layer 12 has light transmission. The conductive layer 12 is made of a material having high light transmittance and conductivity. The conductive layer 12 is directly laminated on the first surface 11a of the base film 11. The conductive layer does not have to be directly laminated on the first surface of the base film. For example, an undercoat layer may be arranged between the conductive layer and the base film.

In the present embodiment, in the TOF-SIMS analysis, the above ratio (total of InOH ⁻ ion strength / total negative ion strength) at the central portion in the thickness direction of the conductive layer 12 is equal to or less than the above upper limit.

Further, the transparent conductive film 1 shown in FIG. 1 may be wound in a roll shape.

From the viewpoint of further enhancing the light transmittance, the total light transmittance of the transparent conductive film at a wavelength of 550 nm is preferably 88% or more, more preferably 89% or more. The total light transmittance of the transparent conductive film at a wavelength of 550 nm is usually 100% or less.

The total light transmittance is measured based on JIS K7105 using a haze meter (“NDH-2000” manufactured by Nippon Denshoku Kogyo Co., Ltd. or an equivalent product thereof).

From the viewpoint of further enhancing the light transmittance, the haze value of the transparent conductive film is preferably 1.3% or less, more preferably 1% or less, still more preferably 0.8% or less. The haze value of the transparent conductive film is usually 0% or more.

The haze value is measured based on JIS K7136 using a haze meter (“NDH-2000” manufactured by Nippon Denshoku Kogyo Co., Ltd. or an equivalent product thereof).

Hereinafter, details of each layer constituting the transparent conductive film will be described.

(Base film)
The base film preferably has high light transmittance. Therefore, the material of the base film is not particularly limited, but for example, polyolefin, polyether sulfone, polysulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethylmethacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene na. Examples include phthalate, triacetyl cellulose, cellulose nanofibers and the like. The material of the base film may be used alone or in combination of two or more.

The thickness of the base film is preferably 5 μm or more, more preferably 20 μm or more, preferably 190 μm or less, and more preferably 125 μm or less. When the thickness of the base film is not less than the above lower limit and not more than the above upper limit, the total thickness of the light control film can be reduced and the handleability at the time of manufacturing the light control film can be improved.

The average transmittance of the base film in the visible light region having a wavelength of 380 to 780 nm is preferably 85% or more, more preferably 90% or more. The average transmittance of the base film in the visible light region having a wavelength of 380 to 780 nm is usually 100% or less.

Further, the base film may contain additives such as various stabilizers, ultraviolet absorbers, plasticizers, lubricants and colorants. The above additives may be used alone or in combination of two or more.

The substrate film may have a hardcourt layer on one or both surfaces.

The material of the hard coat layer is preferably a cured resin. The cured resin may be used alone or in combination of two or more.

Examples of the cured resin include thermosetting resins, active energy ray-curable resins such as ultraviolet curable resins, and the like. From the viewpoint of improving productivity and economy, the cured resin is preferably an ultraviolet curable resin.

The ultraviolet curable resin is preferably a resin obtained by polymerizing a photocurable monomer. The ultraviolet curable resin may be a resin obtained by polymerizing a monomer other than the photocurable monomer. The monomer other than the photocurable monomer and the photocurable monomer may be used alone or in combination of two or more.

Examples of the photocurable monomer include 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, and neo. Pentyl glycol diacrylate, 1,4-butanediol dimethacrylate, poly (butanediol) diacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, triethylene glycol diacrylate, triisopropylene glycol diacrylate, Diacrylate compounds such as polyethylene glycol diacrylate and bisphenol A dimethacrylate; triacrylate compounds such as trimethylol propanetriacrylate, trimethylol propanetrimethacrylate, pentaerythritol monohydroxytriacrylate and trimethylol propanetriethoxytriacrylate; pentaerythritol tetra Examples thereof include tetraacrylate compounds such as acrylate and di-trimethylol propanetetraacrylate; and pentaacrylate compounds such as dipentaerythritol (monohydroxy) pentaacrylate. The ultraviolet curable resin may be a polyfunctional acrylate compound having five or more functionalities. The polyfunctional acrylate compound may be used alone or in combination of two or more. Further, a photoinitiator, a photosensitizer, a leveling agent, a diluent and the like may be added to the polyfunctional acrylate compound.

The hard coat layer may contain a filler. The hard coat layer may contain the cured resin and the filler. The filler is not particularly limited, but for example, metal oxidation of silica, iron oxide, aluminum oxide, zinc oxide, titanium oxide, silicon dioxide, antimony oxide, zirconium oxide, tin oxide, cerium oxide, indium-tin oxide and the like. Material particles; and resin fine particles containing silicone, (meth) acrylic, styrene, melamine, and the like as main components can be mentioned. As the resin fine particles, resin fine particles such as crosslinked poly (meth) methyl acrylate can be used. The filler may be used alone or in combination of two or more.

(Conductive layer)
The conductive layer is formed of a conductive material having light transmission. The conductive material is ITO (indium tin oxide).

The thickness of the conductive layer is preferably 12 nm or more, more preferably 16 nm or more, still more preferably 17 nm or more, preferably 50 nm or less, more preferably 30 nm or less, still more preferably 19.9 nm or less.

When the thickness of the conductive layer is at least the above lower limit, the surface resistance value of the conductive layer of the transparent conductive film can be effectively lowered, and the conductivity can be further improved. When the thickness of the conductive layer is not more than the above upper limit, the transparent conductive film can be made even thinner.

The surface resistance value (sheet resistance value) of the conductive layer of the transparent conductive film is preferably 150 Ω / □ or less, more preferably 130 Ω / □ or less, and further preferably 100 Ω / □ or less. The surface resistance value of the conductive layer is usually 0Ω / □ or more. When the surface resistance value of the conductive layer is not more than the upper limit, the driving speed of the light control film can be improved, and unevenness of the change in color tone can be suppressed.

The surface resistance value of the conductive layer is measured on the surface side of the conductive layer opposite to the base film side, based on JIS K7194.

(Undercoat layer)
An undercoat layer may be arranged between the conductive layer and the base film. The undercoat layer is, for example, a refractive index adjusting layer. By arranging the undercoat layer, the difference in refractive index between the conductive layer and the base film (when the base film has a hard coat layer, the conductive layer and the hard coat layer) can be reduced. Therefore, the light transmittance of the transparent conductive film can be further improved.

The material of the undercoat layer is not particularly limited as long as it is a material having a refractive index adjusting function. Examples of the material of the undercoat layer include _{inorganic materials such as SiO 2} , MgF ₂ , and Al ₂ O ₃ , and organic materials such as acrylic resin, urethane resin, melamine resin, alkyd resin, and siloxane polymer.

The undercoat layer can be formed by a vacuum vapor deposition method, a sputtering method, an ion plating method or a coating method.

When the material of the undercoat layer is SiO ₂ , by adjusting the film forming process such as a sputtering method, the completely oxidized SiO ₂ layer and the partially oxidized SiO _x (0≤x <2) layer can be obtained. A laminated undercoat layer can be formed. Specifically, the degree of oxidation of Si can be adjusted by adjusting _{the O 2} partial pressure when forming the _{SiO 2} layer by the sputtering method using a Si target. Further, when the undercoat layer is a SiO _x layer, the adhesion between the conductive layer and the SiO ₂ layer and the adhesion between the base film and the SiO ₂ layer can be improved.

(Protective film)
The protective film may be arranged on the surface (on the other surface) opposite to the conductive layer side of the base film.

The protective film is preferably composed of a base film sheet and an adhesive layer.

The base film sheet preferably has high light transmittance. The material of the base film sheet is not particularly limited, but for example, polyolefin, polyether sulfone, polysulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethylmethacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene na. Examples include phthalate, triacetyl cellulose, cellulose nanofibers and the like.

The pressure-sensitive adhesive layer can be composed of, for example, a (meth) acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a urethane-based adhesive, or an epoxy-based adhesive. From the viewpoint of suppressing an increase in the adhesive force due to the heat treatment, the pressure-sensitive adhesive layer is preferably composed of a (meth) acrylic pressure-sensitive adhesive.

The (meth) acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive obtained by adding a cross-linking agent, a tackifier resin, various stabilizers, and the like to the (meth) acrylic polymer, if necessary.

The (meth) acrylic polymer is not particularly limited, but is a (meth) acrylic obtained by copolymerizing a mixed monomer containing a (meth) acrylic acid ester monomer and another copolymerizable polymerizable monomer. It is preferably a polymer.

The (meth) acrylic acid ester monomer is not particularly limited, but can be obtained by an esterification reaction between a primary or secondary alkyl alcohol having an alkyl group having 1 to 12 carbon atoms and (meth) acrylic acid (meth). Meta) Acrylic acid ester monomers are preferred. Specific examples of the (meth) acrylic acid ester monomer include ethyl (meth) acrylate, butyl (meth) acrylate, and -2-ethylhexyl (meth) acrylate. The above (meth) acrylic acid ester monomer may be used alone or in combination of two or more.

Examples of the other copolymerizable monomer such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate; Isobornyl (meth) acrylate, hydroxyalkyl (meth) acrylate, glycerin dimethacrylate, glycidyl (meth) acrylate, 2-methacryloyloxyethyl isocyanate, (meth) acrylic acid, itaconic acid, maleic anhydride, crotonic acid, malein Examples include functional monomers such as acrylic acid and fumaric acid. The other copolymerizable monomers may be used alone or in combination of two or more.

The cross-linking agent is not particularly limited, and for example, an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, a melamine-based cross-linking agent, a peroxide-based cross-linking agent, a urea-based cross-linking agent, a metal alkoxide-based cross-linking agent, and a metal chelate-based cross-linking agent. Examples thereof include agents, metal salt-based cross-linking agents, carbodiimide-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, amine-based cross-linking agents, polyfunctional acrylates and the like. The above-mentioned cross-linking agent may be used alone or in combination of two or more.

The tackifier resin is not particularly limited, but is, for example, a petroleum-based resin such as an aliphatic copolymer, an aromatic copolymer, an aliphatic / aromatic copolymer, and an alicyclic copolymer. Examples thereof include kumaron-inden-based resin; terpene-based resin; terpenephenol-based resin; rosin-based resin such as polymerized rosin; phenol-based resin; xylene-based resin and the like. The tackifier resin may be a hydrogenated resin. The pressure-sensitive adhesive resin may be used alone or in combination of two or more.

The thickness of the protective film is preferably 25 μm or more, more preferably 50 μm or more, preferably 300 μm or less, and more preferably 200 μm or less. When the thickness of the protective film is not less than the above lower limit and not more than the above upper limit, the workability of the photochromic film is excellent and the handleability at the time of manufacturing can be improved.

(Dimmable film)
The light control film according to the present invention includes a first transparent conductive film, a second transparent conductive film, and a light control layer. The dimming layer is arranged between the first transparent conductive film and the second transparent conductive film. In the light control film according to the present invention, at least one of the first transparent conductive film and the second transparent conductive film is the transparent conductive film according to the present invention. One of the first transparent conductive film and the second transparent conductive film may be the transparent conductive film according to the present invention, and both the first transparent conductive film and the second transparent conductive film may be used. , The transparent conductive film according to the present invention may be used.

FIG. 2 is a cross-sectional view showing an example of a light control film using the transparent conductive film for light control film shown in FIG.

The light control film 21 includes two transparent conductive films 1 and a light control layer 31. A dimming layer 31 is arranged between the two transparent conductive films 1. The conductive layer 12 in the transparent conductive film 1 is in contact with the dimming layer 31.

In the light control film 21, an electric field is applied between the conductive layers 12 of the two transparent conductive films 1. The amount of light passing through the light control film 21 can be changed depending on whether an electric field is applied or not.

The dimming layer may contain an acrylic resin. The dimming layer may contain liquid crystal molecules in the acrylic resin. From the viewpoint of effectively enhancing the adhesion between the conductive layer and the light control layer, the light control layer preferably contains an acrylic resin.

Hereinafter, the present invention will be described in more detail based on specific examples and comparative examples. The present invention is not limited to the following examples.

(Example 1)
Fabrication of transparent conductive film:
As a base film, a PET film having a thickness of 125 μm was prepared. An acrylic hard coat resin in which zirconia particles were dispersed was applied to one surface of the PET film to form a hard coat layer 1 having a thickness of 1.0 μm. An acrylic hard coat resin was applied to the other surface of the PET film to form a hard coat layer 2 having a thickness of 1.5 μm. In this way, a double-sided hardcourt film was obtained.

This double-sided hardcourt film was installed in a vacuum device and evacuated. After the degree of vacuum ^{reached 9.0 × 10 -4} Pa, argon gas was introduced so that the total pressure became 0.33 Pa, and the water pressure was 0. It waited until it reached 0005Pa. _{Next, a SiO x} layer (2 nm), a SiO ₂ layer (16 nm), and a SiO _x layer (2 nm) are formed in this order from the hard coat layer 1 side by the DC magnetron sputtering method, and indium tin oxide (ITO) is formed therein. ) Layers were laminated. Specifically, an ITO sintered body target in which the film forming roll (can roll) temperature of the RtR sputtering apparatus is set to -10 ° C. and SnO ₂ is 7% by weight, and a cathode having a maximum horizontal magnetic flux density of 1000 gauss on the target surface. Was used to form a conductive layer (indium tin oxide layer) having a thickness of 17 nm. Then, an annealing treatment was performed at 150 ° C. for 60 minutes in a hot air circulation oven to obtain a light-transmitting conductive film.

(Examples 2 to 4 and Comparative Examples 1 to 3)
A transparent conductive film was obtained in the same manner as in Example 1 except that the conditions for forming the conductive layer (total spatter pressure, water pressure at the time of spatter, and roll temperature) were set as shown in Table 1 below. The total spatter pressure was controlled by adjusting the argon introduction flow rate. The moisture pressure during sputtering was controlled by adjusting the vacuum holding time until the start of sputter film formation and the pre-drying treatment method (drying temperature 105 ° C.) of the double-sided hard coat film.

(evaluation)
(1) TOF-SIMS analysis Measurement was performed in the thickness direction by continuously performing C60 sputtering at the same point on the surface of the conductive layer opposite to the base film side. From ^{the measurement results at the time when the number of In +} ions detected was ^{half the number of spatters when the number of In + ions detected was less than the number of Si +} ions detected, the intensity ratio at the center of the conductive layer in the thickness direction (InOH ⁻ ion intensity / The total intensity of all negative ions) was calculated.

Furthermore, in the TOF-SIMS analysis, the measurement result in the first sputtering the surface opposite to the above-mentioned substrate film side of the conductive layer, the intensity ratio (intensity of H ₃ O ⁺ ion intensity / an In ⁺ ions) Asked.

The specific measurement conditions for TOF-SIMS are as follows.

TOF-SIMS device: ION-TOF, TOF-SIMS5 type primary ion: 209Bi ⁺¹
Ion voltage: 25kV
Ion current: 1pA
Mass range: 1-500 mass
Analysis area: 500 μm □
Charge prevention: Electron irradiation Neutralization Spatter ion: C60
Ion voltage: 20 keV
Ion current: 3nA
Spatter area: 300 μm □

(2) Evaluation of Acid Resistance 1 The transparent conductive film was immersed in 1% by weight of hydrochloric acid for 30 minutes. The rate of change in the sheet resistance value (surface resistance value of the conductive layer) before and after immersion was determined. The ratio of the sheet resistance value Rs after immersion to the sheet resistance value Rs0 before immersion should be closer to 1.0. The sheet resistance value was measured based on JIS K7194 using "Loresta AX MCP-T370" manufactured by Mitsubishi Chemical Analytech.

(3) Evaluation of Acid Resistance 2 The transparent conductive film was immersed in 5% by weight hydrochloric acid for 30 minutes. In the same manner as in the evaluation of (2) acid resistance 1 described above, the rate of change in the sheet resistance value (surface resistance value of the conductive layer) before and after immersion was determined. The ratio of the sheet resistance value Rs after immersion to the sheet resistance value Rs0 before immersion should be closer to 1.0. In addition, when the sheet resistance value Rs deteriorated significantly and the measurement result was out of the measurement range and the measurement result could not be obtained, it was described as "Measurement not possible" in Table 1.

(4) Sheet resistance value (surface resistance value of conductive layer)
The sheet resistance value (surface resistance value of the conductive layer) of the obtained transparent conductive film was measured using "Loresta AX MCP-T370" manufactured by Mitsubishi Chemical Analytech Co., Ltd. based on JIS K7194.

(5) Total light transmittance The total light transmittance of the obtained transparent conductive film at a wavelength of 550 nm was measured using a haze meter (“NDH-2000” manufactured by Nippon Denshoku Kogyo Co., Ltd.) based on JIS K7105. ..

(6) Haze value The haze value of the obtained transparent conductive film was measured using a haze meter (“NDH-2000” manufactured by Nippon Denshoku Kogyo Co., Ltd.) based on JIS K7136.

The conditions for forming the conductive layer and the results are shown in Table 1 below.

1 ... Transparent conductive film 11 ... Base film 11a ... First surface 11b ... Second surface 12 ... Conductive layer 21 ... Dimming film 31 ... Dimming layer

Claims (7)

A transparent conductive film used for dimming film.
It has a base film and a conductive layer arranged on one surface side of the base film, and the conductive layer is an indium tin oxide oxide layer.
A transparent conductive film for a light control film in which the ratio of the intensity ^{of InOH-} ions in the central portion of the conductive layer in the thickness direction to the total intensity of all negative ions is 0.0005 or less in the TOF-SIMS analysis. In TOF-SIMS analysis, and the base film side of the conductive layer the ratio to the intensity of the In ⁺ ion intensity of _H 3 ^{O +} ions at the opposite surface is 0.05 or less, according to claim 1 Transparent conductive film for dimming film. The transparent conductive film for a light control film according to claim 1 or 2, wherein the surface resistance value of the conductive layer is 150 Ω / □ or less. The total light transmittance at a wavelength of 550 nm is 88% or more, and the total light transmittance is 88% or more.
The transparent conductive film for a light control film according to any one of claims 1 to 3, wherein the haze value is 1.3% or less. The transparent conductive film for a light control film according to any one of claims 1 to 4, which is used so that the conductive layer comes into contact with the light control layer containing an acrylic resin. The first transparent conductive film and
The second transparent conductive film and
A dimming layer arranged between the first transparent conductive film and the second transparent conductive film is provided.
A light control film in which at least one of the first transparent conductive film and the second transparent conductive film is the transparent conductive film for a light control film according to any one of claims 1 to 5. The light control film according to claim 6, wherein the light control layer contains an acrylic resin.

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