JP2019040188A - Transparent conductive film for light control films, and light control film - Google Patents

Abstract

To provide a transparent conductive film for light control films that can improve adhesion between a conductive layer and a light control layer.SOLUTION: A transparent conductive film for light control films is used for a light control film. The transparent conductive film has a substrate film, and a conductive layer disposed on one surface side of the substrate film. One surface of the conductive layer, not the other surface on which the substrate film is disposed, has a contact angle to a methyl methacrylate monomer of 9° or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transparent conductive film used for a light control film. Moreover, this invention relates to the light control film using the said transparent conductive film.

  A light control material or the like is used for the light control film. The light modulating material is used for the purpose of adjusting the transmittance or adjusting the color tone by blocking light of a specific wavelength. The light control film is utilized in various fields, such as an indoor member, a building member, and an electronic component.

  For example, the light control film has a structure in which a light control layer is disposed between two transparent conductive films. The transparent conductive film used for the said light control film has a base film and a conductive layer on the surface of this base film. In the light control film, the conductive layer is opposed to 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 light control film can be changed between a state where an electric field is applied and a state where no electric field is applied.

  An example of the transparent conductive film used for the light control film is disclosed in Patent Document 1 below.

WO2008 / 075752A1

  In the conventional transparent conductive film as described in Patent Document 1, the adhesion between the conductive layer and the light control layer may be lowered. As a result, the light control performance of the light control film may deteriorate, or when the light control film is used for a long period of time, the conductive layer and the light control layer may peel off and the light control performance may be lost. .

  The objective of this invention is providing the transparent conductive film for light control films which can improve the adhesiveness of a conductive layer and a light control layer. Another object of the present invention is to provide a light control film using the transparent conductive film for light control film.

  According to a wide aspect of the present invention, there is provided a transparent conductive film used for a light control film, comprising a base film and a conductive layer disposed on one surface side of the base film, and the conductive film There is provided a transparent conductive film for a light control film having a contact angle of 9 ° or less with respect to methyl methacrylate monomer on the surface opposite to the base film side of the layer.

  On the specific situation with the transparent conductive film for light control films which concerns on this invention, the contact angle with respect to the 2-ethylhexyl methacrylate monomer of the surface on the opposite side to the said base film side of the said conductive layer is 9 degrees or less.

  According to a wide aspect of the present invention, the first transparent conductive film, the second transparent conductive film, and the light control layer disposed between the first transparent conductive film and the second transparent conductive film. A light control film is provided, wherein at least one of the first transparent conductive film and the second transparent conductive film is the above-described transparent conductive film for a light control film.

  On the specific situation with the light control film which concerns on this invention, the said light control layer contains an acrylic resin.

  ADVANTAGE OF THE INVENTION According to this invention, the transparent conductive film for light control films which can improve the adhesiveness of a conductive layer and a light control layer can be provided.

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. FIG. 3 is a photograph at the time of measurement of the contact angle with respect to methyl methacrylate monomer on the surface opposite to the base film side of the conductive layer of the transparent conductive film for light control film according to one embodiment of the present invention. FIG. 4 is a photograph at the time of measuring a contact angle with respect to methyl methacrylate monomer on the surface opposite to the base film side of the conductive layer of the conventional transparent conductive film for light control film.

  Hereinafter, the present invention will be described in detail.

  The transparent conductive film for light control films according to the present invention (hereinafter sometimes referred to as a transparent conductive film) is used as a light control film. The transparent conductive film is transparent. Translucent includes translucent. Since the transparent conductive film is transparent, it has optical transparency. The transparent conductive film has conductivity.

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

  In the transparent conductive film according to the present invention, the contact angle with respect to the methyl methacrylate monomer on the surface opposite to the base film side of the conductive layer is 9 ° or less. The surface opposite to the base film side of the conductive layer is the surface in contact with the light control layer.

  In the transparent conductive film which concerns on this invention, since said structure is provided, the adhesiveness of a conductive layer and a light control layer can be improved. As a result, problems due to peeling between the conductive layer and the light control layer can be suppressed. In addition, unevenness in light control performance is less likely to occur, and good light control performance can be obtained.

  From the viewpoint of further improving the adhesion between the conductive layer and the light control layer, the contact angle of the conductive layer with respect to the methyl methacrylate monomer on the surface opposite to the base film side is 9 ° or less, preferably 7 Or less, more preferably 5 ° or less, even more preferably 3 ° or less, particularly preferably 2 ° or less, and most preferably 1 ° or less. The contact angle with respect to the methyl methacrylate monomer on the surface opposite to the base film side of the conductive layer is usually 0 ° or more.

  From the viewpoint of further improving the adhesion between the conductive layer and the light control layer, the contact angle of the surface of the conductive layer opposite to the base film side with respect to the 2-ethylhexyl methacrylate monomer is preferably 9 ° or less, more The angle is preferably 7 ° or less, more preferably 6 ° or less, and particularly preferably 4 ° or less. The contact angle with respect to the 2-ethylhexyl methacrylate monomer on the surface opposite to the base film side of the conductive layer is usually 0 ° or more.

  The contact angle for each of the methyl methacrylate monomer and the 2-ethylhexyl methacrylate monomer can be measured using a contact angle meter (for example, “DM500” manufactured by Kyowa Interface Science Co., Ltd. or an equivalent thereof). Specifically, 1 μL of methyl methacrylate monomer or 2-ethylhexyl methacrylate monomer is dropped onto the surface of the transparent conductive film opposite to the base film side of the conductive layer. The angle formed by the methyl methacrylate monomer one second after the dropping and the surface of the conductive layer is defined as the contact angle with respect to the methyl methacrylate monomer. Further, an angle formed by the 2-ethylhexyl methacrylate monomer and the surface of the conductive layer one second after the dropping is defined as a contact angle with respect to the 2-ethylhexyl methacrylate monomer.

Examples of the method for controlling the contact angle with respect to each of the methyl methacrylate monomer and the 2-ethylhexyl methacrylate monomer within the above range include the following methods (1) to (4). (1) A method for controlling the substrate temperature during formation of the conductive layer. (2) A method of controlling the H ₂ O pressure when the conductive layer is formed by sputtering. (3) A method of controlling the annealing conditions after the formation of the conductive layer. (4) A method of performing surface treatment such as corona treatment and plasma treatment on the surface of the conductive layer.

  The transparent conductive film is preferably used such that the conductive layer is in contact with a light control layer containing an acrylic resin. In this invention, even if a conductive layer touches the light control layer containing an acrylic resin, the adhesiveness of the conductive layer of a transparent conductive film and a light control layer can be improved.

  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 for 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 transmittance. The base film 11 is made of a light transmissive material. The base film 11 has a first surface 11a and a second surface 11b. The first surface 11a and the second surface 11b are opposed to each other.

  A conductive layer 12 is disposed on the first surface 11 a side of the base film 11. The conductive layer 12 is light transmissive. 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 11 a of the base film 11. The conductive layer may not be directly laminated on the first surface of the base film. For example, an undercoat layer may be disposed between the conductive layer and the base film.

  In this embodiment, the contact angle with respect to the methyl methacrylate monomer on the surface opposite to the base film 11 side of the conductive layer 12 satisfies the above-described range.

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

  From the viewpoint of further increasing the light transmittance, the total light transmittance of the transparent conductive film at a wavelength of 550 nm is preferably 85% or more, more preferably 88% or more, still more preferably 89% or more, and particularly preferably 90%. That's it. In addition, the said total light transmittance of the said transparent conductive film is 100% or less normally. It can be said that a transparent conductive film has favorable light transmittance as the total light transmittance in wavelength 550nm of the said transparent conductive film is 85% or more.

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

  From the viewpoint of further increasing the light transmittance, the haze value of the transparent conductive film is preferably 1.3% or less, more preferably 0.8% or less, still more preferably 0.6% or less, and particularly preferably 0. .4% or less. In addition, the haze value of the said transparent conductive film is 0% or more normally.

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

  Hereinafter, the detail of each layer which comprises a transparent conductive film is demonstrated.

(Base film)
In the transparent conductive film according to the present invention, the base film may have a base film body and a hard coat layer. When the base film has the hard coat layer, the hard coat layer is laminated on the first surface of the base film body and the second surface opposite to the first surface. Preferably it is.

  The base film preferably has high light transmittance. Accordingly, the material for the base film and the material for the base film body are not particularly limited. For example, polyolefin, polyether sulfone, polyether ether ketone, polysulfone, polycarbonate, cycloolefin polymer, cycloolefin copolymer, Examples include polyarylate, polyamide, polyimide, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, triacetyl cellulose, and cellulose nanofiber. The material of the base film and the material of the base film body may be used alone or in combination.

  The thickness of the base film is preferably 5 μm or more, more preferably 20 μm or more, still more preferably 35 μm or more, preferably 190 μm or less, more preferably 125 μm or less, and even more preferably 60 μm or less. When the thickness of the substrate film is not less than the above lower limit and not more than the above upper limit, the workability of the light control film to the window and the like becomes good. Moreover, a transparent conductive film and a light control film can be made thin, improving handleability as the thickness of a base film is more than the said minimum and below the said upper limit.

  When the base film has the base film body and the hard coat layer, the thickness of the base film body is preferably 5 μm or more, more preferably 20 μm or more, still more preferably 35 μm or more, preferably It is 190 micrometers or less, More preferably, it is 125 micrometers or less, More preferably, it is 60 micrometers or less. When the thickness of the base film body is not less than the above lower limit and not more than the above upper limit, the workability of the light control film to the window or the like becomes good. Moreover, a transparent conductive film and a light control film can be made thin, improving handling property as the thickness of a base film main body is more than the said minimum and below the said upper limit.

  Moreover, the average transmittance | permeability in the visible light region of wavelength 380-780 nm of a base film becomes like this. Preferably it is 85% or more, More preferably, it is 90% or more. The average transmittance in the visible light region with a wavelength of 380 to 780 nm is usually 100% or less. It can be said that a base film has favorable light transmittance as the average transmittance | permeability in the visible light region with a wavelength of 380-780 nm of the said base film is 85% or more.

  When the base film or the base film has the base film main body and the hard coat layer, the base film main body is added with various stabilizers, ultraviolet absorbers, plasticizers, lubricants, or coloring agents. An agent may be included. Each of the above additives may be used alone or in combination.

(Conductive layer)
The conductive layer is made of a light-transmitting conductive material. As the conductive material is not particularly limited, for example, IZO (indium zinc oxide) and ITO an In-based oxide (indium tin oxide) or the like, Sn-based, such as SnO ₂ and FTO (fluorine-doped tin oxide) Oxides, Zn-based oxides such as AZO (aluminum zinc oxide) and GZO (gallium zinc oxide), aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Al ₂ O ₃ mixture, Examples include Al / LiF mixtures and metals such as gold, CuI, Ag nanowires (AgNW), carbon nanotubes (CNT), and conductive transparent polymers. The said electroconductive material may be used independently and may use multiple together.

  The conductive material is preferably a metal oxide containing In, a metal oxide containing Sn, or a metal oxide containing Zn. The conductive material is more preferably a metal oxide containing In, and more preferably ITO (indium tin oxide). By using these conductive materials, the conductivity can be further enhanced and the light transmittance can be further enhanced.

  The method for forming the conductive layer is not particularly limited, and examples thereof include physical vapor deposition (for example, vapor deposition, ion plating, sputtering) and chemical vapor deposition (for example, plasma CVD). In the present invention, the method for forming the conductive layer is preferably a sputtering method.

As a method for forming a conductive layer by sputtering, for example, a layer containing silicon oxide is formed on one surface of a base film, and then a conductive material is laminated on the layer containing silicon oxide. Then, the method of heat-processing (annealing) is mentioned. As a film forming method of the layer containing silicon oxide, the base film is placed in a vacuum apparatus, and the degree of vacuum is, for example, 1.0 × 10 ^{−6 to} 1.0 × 10 ⁻⁴ Pa. The method of sputtering on one surface of a base film is mentioned. The method for laminating the conductive material is not particularly limited. For example, the chamber pressure (total pressure) of a mixed gas of argon gas and oxygen gas is 3.0 × 10 ^{−1 to} 9.0 × 10 ^−1. A method of laminating a conductive material by a sputtering method while introducing into a vacuum apparatus so as to be Pa can be mentioned.

At this time, the H ₂ O partial pressure is preferably 1.0 × 10 ⁻⁴ Pa or more, preferably 1.0 × 10 ⁻³ Pa or less, and 4.0 × 10 ⁻⁴ Pa or less. More preferably. When the H ₂ O partial pressure is not less than the above lower limit and not more than the above upper limit, the crystallinity of the conductive layer after the annealing treatment can be improved. As a result, the contact angle with respect to each of the methyl methacrylate monomer and the 2-ethylhexyl methacrylate monomer can be easily adjusted to the above range. Further, when the H 2 _O partial pressure is less than the lower limit or more and the upper limit, it is possible to lower the sheet resistance of the transparent conductive film. When ITO is used as the conductive material, the crystallinity of the ITO layer after the annealing treatment can be enhanced when the H ₂ O partial pressure is not less than the above lower limit and not more than the above upper limit. As a result, the contact angle with respect to each of the methyl methacrylate monomer and the 2-ethylhexyl methacrylate monomer can be easily adjusted to the above range. Further, when the H 2 _O partial pressure is less than the lower limit or more and the upper limit, it is possible to lower the sheet resistance of the transparent conductive film.

The H ₂ O partial pressure can be measured using a mass spectrometer (for example, “Qulee CGM-051” manufactured by ULVAC, or an equivalent thereof) corresponding to a vacuum apparatus.

  The heat treatment (annealing treatment) is performed by performing a heat treatment at 120 to 200 ° C. for about 1 to 60 minutes using a hot air circulating oven, a hot roll, a hot press, an IR heating oven, or the like. Can do.

  When ITO is used as the conductive material, it is preferable to form the ITO layer (conductive layer) by crystallizing ITO by heat treatment (annealing treatment). For the heat treatment (annealing treatment), a hot air circulation oven, a hot roll, a hot press, an IR heating oven, or the like can be used. From the viewpoint of forming the ITO layer in a shorter time, it is preferable to use an IR heating oven. In this case, reduction of oxygen deficiency due to oxidation of the ITO layer surface, deterioration of the base film, and the like can be effectively suppressed. In addition, the said heat processing (annealing process) can be implemented by performing the heat processing for about 1 to 10 minutes at 160-200 degreeC, for example.

  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 20 nm or less, and particularly preferably 19 nm or less. When the thickness of the conductive layer is not less than the above lower limit, the sheet resistance value of the transparent conductive film can be effectively reduced, and the conductivity can be further increased. When the thickness of the conductive layer is not more than the above upper limit, a more transparent transparent conductive film can be obtained. When the thickness of the conductive layer is not more than the above upper limit, the light control layer is easily cured well, and the transparency of the light control film can be further increased.

  The average transmittance in the visible light region having a wavelength of 380 to 780 nm of the conductive layer is preferably 85% or more, more preferably 90% or more. The average transmittance in the visible light region with a wavelength of 380 to 780 nm is usually 100% or less. It can be said that the conductive layer has good light transmittance when the average transmittance in the visible light region having a wavelength of 380 to 780 nm of the conductive layer is 85% or more.

(Protective film)
The protective film may be arrange | positioned on the surface (on the other surface) opposite to the said conductive layer side of the said 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. For example, polyolefin, polyethersulfone, polysulfone, polycarbonate, cycloolefin polymer, polyarylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate. Examples include phthalate, triacetylcellulose, and cellulose nanofiber. The material of the said base film sheet may be used independently and may use multiple together.

  The pressure-sensitive adhesive layer can be composed of 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 adhesive force due to heat treatment, the adhesive layer is preferably composed of a (meth) acrylic adhesive.

  The (meth) acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive in which a crosslinking agent, a tackifier resin, various stabilizers, and the like are added to a (meth) acrylic polymer as necessary.

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

  Although it does not specifically limit as said (meth) acrylic acid ester monomer, It is obtained by esterification reaction of the primary or secondary alkyl alcohol whose carbon number of an alkyl group is 1-12, and (meth) acrylic acid ( A meth) acrylic acid ester monomer is preferred. Specific examples of the (meth) acrylic acid ester monomers include ethyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid-2-ethylhexyl. The said (meth) acrylic acid ester monomer may be used independently and may use multiple together.

  Examples of other copolymerizable polymerizable monomers include hydroxyalkyl (meth) acrylates 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 thereof include functional monomers such as acid and fumaric acid. The other copolymerizable polymerizable monomers may be used alone or in combination.

  The crosslinking agent is not particularly limited, and for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal alkoxide crosslinking agent, a metal chelate crosslinking agent. Agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents, and polyfunctional acrylates. The above crosslinking agents may be used alone or in combination.

  The tackifying resin is not particularly limited, and examples thereof include petroleum resins such as aliphatic copolymers, aromatic copolymers, aliphatic / aromatic copolymers, and alicyclic copolymers. Coumarone-indene resin; terpene resin; terpene phenol resin; rosin resin such as polymerized rosin; phenol resin; xylene resin. The tackifying resin may be a hydrogenated resin. The tackifying resins may be used alone or in combination.

  The thickness of the protective film is preferably 25 μm or more, more preferably 50 μm or more, preferably 300 μm or less, 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 handling property at the time of producing the light control film is excellent, and the occurrence of defects can be reduced.

(Light control film)
The light control film which concerns on this invention is equipped with a 1st transparent conductive film, a 2nd transparent conductive film, and a light control layer. The light control layer is disposed 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 are 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 light control layer 31 is disposed between the two transparent conductive films 1. The conductive layer 12 in the transparent conductive film 1 is in contact with the light control 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 between a state where an electric field is applied and a state where no electric field is applied.

  Examples of the light control layer method include a liquid crystal dispersion polymer method, an electrochromic method, and an SPD method.

  The light control layer may contain an acrylic resin. The light control layer preferably contains an acrylic resin. The light control layer may contain liquid crystal molecules in the acrylic resin.

  The acrylic resin is not particularly limited, and examples thereof include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate, ( Examples thereof include polymers of monomers such as 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isopropyl (meth) acrylate, and propyl (meth) acrylate. The acrylic resin may be a homopolymer of the monomer, may be a copolymer of the monomer, or may be a copolymer of the monomer and another monomer. The above acrylic resins may be used alone or in combination. “(Meth) acryl” means acrylic or methacrylic.

  From the viewpoint of enhancing the adhesion between the conductive layer and the light control layer, the peel strength of the transparent conductive film with respect to the light control layer is preferably 3.0 N / inch or more, more preferably 3.3 N / inch or more, and still more preferably. Is 3.5 N / inch or more.

  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
Production of transparent conductive film:
A PET film having a thickness of 50 μm was prepared as the base film body. After applying an acrylic hard coat resin in which zirconia particles are dispersed ("Rioduras TYZ" manufactured by Toyo Ink Co., Ltd.) on one side of the PET film, it is cured by irradiating with UV, and the first hard having a thickness of 0.8 μm A coat layer was formed. On the other side of the PET film, an acrylic hard coat resin (“Rioduras TYAB” manufactured by Toyo Ink Co., Ltd.) is applied and then cured by UV irradiation to form a second hard coat layer having a thickness of 2.0 μm. did. In this way, a base film was obtained.

This base film was placed in a vacuum apparatus and evacuated. After the degree of vacuum reaches 9.0 × 10 ⁻⁴ Pa, argon gas is introduced, and an SiO _x layer, SiO ₂ layer is formed on the surface of the first hard coat layer in an argon gas atmosphere by a DC magnetron sputtering method. A layer and a SiO _x layer were formed in this order from the first hard coat layer side, and an indium tin oxide (ITO) layer was laminated thereon. Specifically, a chamber pressure of 3.5 × 10 ⁻¹ Pa, H ₂ using an ITO sintered body target of 7 wt% SnO ₂ and a cathode having a maximum horizontal magnetic flux density of 1000 gauss on the target surface. A conductive layer (ITO layer) having a thickness of 18 nm was formed while being introduced into a vacuum apparatus with an O partial pressure of 2.72 × 10 ⁻⁴ Pa and a ratio of Ar gas to O ₂ gas of 100: 1. Then, the transparent conductive film was obtained by performing an annealing process at 170 degreeC for 5 minute (s) with IR heating type oven (Mino group company make).

Preparation of light control film:
The following components were mixed to obtain a light control layer material.

75 parts by weight of 4-butylbiphenyl-4′-carbonitrile and 75 parts by weight of 4′-hydroxy-4-biphenylcarbonitrile as liquid crystal components 20 parts by weight of 2-ethylhexyl methacrylate and 2-ethylhexyl acrylate 130 as binder resins 3 parts by weight of photopolymerization initiator (“Irgacure 184” manufactured by BASF) 1 part by weight of acrylic resin particles having a particle size of 20 μm (Micropearl, manufactured by Sekisui Chemical Co., Ltd.) as a gap material for adjusting the thickness of the light control layer

Two layers of the transparent conductive film were set on a laminator (a small laminator manufactured by Tester Sangyo Co., Ltd.) so that the conductive layer sides face each other, and the light control layer material was poured between them to perform bonding. A light control layer was formed by curing the light control layer material on the obtained laminated film with a UV lamp under conditions of 150 W / m ² and 5 minutes to obtain a light control film.

(Examples 2 to 5 and Comparative Examples 1 and 2)
The thickness of the base film body, the formation conditions of the conductive layer (H ₂ O partial pressure), the thickness of the conductive layer, and the annealing treatment conditions (heating method, heating temperature, and heating time) are set as shown in Table 1 below. Except having done, it carried out similarly to Example 1, and obtained the transparent conductive film and the light control film.

(Measurement)
(1) Contact angle with respect to methyl methacrylate monomer In the obtained transparent conductive film, the contact angle with respect to methyl methacrylate monomer was measured using a contact angle meter ("DM500" manufactured by Kyowa Interface Science Co., Ltd.). Specifically, 1 μL of methyl methacrylate monomer was dropped onto the surface of the transparent conductive film opposite to the base film side of the conductive layer. The angle formed by the methyl methacrylate monomer and the surface of the conductive layer one second after the dropping was defined as the contact angle with respect to the methyl methacrylate monomer.

(2) Contact angle with respect to 2-ethylhexyl methacrylate monomer In the obtained transparent conductive film, the contact angle with respect to 2-ethylhexyl methacrylate monomer was measured using a contact angle meter ("DM500" manufactured by Kyowa Interface Science Co., Ltd.). Specifically, 1 μL of 2-ethylhexyl methacrylate monomer was dropped onto the surface of the transparent conductive film opposite to the base film side of the conductive layer. The angle formed by 2-ethylhexyl methacrylate monomer and the surface of the conductive layer 1 second after the dropping was defined as the contact angle with respect to the 2-ethylhexyl methacrylate monomer.

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

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

(Evaluation)
(1) Peel strength The peel strength when two transparent conductive films constituting the obtained light control film were peeled in the 180 ° direction was defined as peel strength. The peel strength was determined by measuring with a tensile tester. As a tensile tester, “EZ Test” manufactured by Shimadzu Corporation was used. The light control film was cut to a width of 1 inch and measured. The peeling speed was 100 mm / min.

  The composition of the transparent conductive film, the annealing conditions and the results are shown in Table 1 below.

  At the time of measuring the contact angle of the transparent conductive films obtained in Examples 1 to 5 with respect to the methyl methacrylate monomer, an observation result similar to the photograph shown in FIG. 3 was obtained.

  Moreover, the observation result similar to the photograph shown in FIG. 4 was obtained at the time of the measurement of the contact angle with respect to the methyl methacrylate monomer of the transparent conductive film obtained in Comparative Examples 1 and 2.

DESCRIPTION OF SYMBOLS 1 ... Transparent conductive film 11 ... Base film 11a ... 1st surface 11b ... 2nd surface 12 ... Conductive layer 21 ... Light control film 31 ... Light control layer

Claims (4)

A transparent conductive film used for a light control film,
A base film, and a conductive layer disposed on one surface side of the base film,
The transparent conductive film for light control films whose contact angle with respect to the methyl methacrylate monomer of the surface on the opposite side to the said base film side of the said conductive layer is 9 degrees or less.   The transparent conductive film for light control films of Claim 1 whose contact angle with respect to the 2-ethylhexyl methacrylate monomer of the surface on the opposite side to the said base film side of the said conductive layer is 9 degrees or less. A first transparent conductive film;
A second transparent conductive film;
A light control layer disposed between the first transparent conductive film and the second transparent conductive film;
The light control film whose at least one of a said 1st transparent conductive film and a said 2nd transparent conductive film is the transparent conductive film for light control films of Claim 1 or 2. The light control film of Claim 3 in which the said light control layer contains an acrylic resin.