JP2018128595A - Dimming film, and dimming device and screen using the same - Google Patents

Abstract

Kind Code: A1 A light control film having a transparent conductive film having sufficient wettability and solvent resistance for attaching a liquid crystal, an alignment film, and a conductive paste for power supply without hydrophilization is provided. A light-modulating layer, a transparent electrode made of a transparent conductive film on both sides of the light-modulating layer, and a transparent base material are provided in this order. A light control film that can be switched between two or more types, wherein the transparent conductive film contains a conductive material and a polymerizable resin, the transparent conductive film has a pure water contact angle of 5 to 80°, and is transparent conductive. The light control film has a surface resistance value of 300 Ω/□ or less in a region of the film where a nonwoven fabric containing an organic solvent is reciprocated 10 times with a load of 200 g/cm 2 . [Selection figure] None

Description

  The present invention relates to a light control film provided with a light control layer using liquid crystal, a light control device using the light control film, and a screen.

  LCD light control film is a film that uses liquid crystal and instantly switches between “transparent” and “white turbidity” by turning the power on and off, and controls the light that passes through. Also, it has a function as a video projection screen. In addition, the white turbidity (cloudiness) of the light control film is usually called haze.

  There are two types of liquid crystal light control films (hereinafter referred to as light control films): normal mode and reverse mode. As shown in FIG. 1, the former uses a polymer liquid crystal composite film in which liquid crystal molecules are wrapped in a polymer as a light control layer (3A or 3B), and the light control layer is formed of transparent electrodes 2a and 2b made of a transparent conductive film from both sides. And has a structure sandwiched between the transparent substrates 1a and 1b. In the reverse mode, as shown in FIG. 2, alignment films 9a and 9b are further provided between the light control layer (3A or 3B) and the transparent electrodes 2a and 2b.

  There are several types of polymer liquid crystals used for the polymer liquid crystal composite film, but a typical type is called a polymer network liquid crystal (PNLC) (Patent Document 1), a high type A type called a molecular dispersed liquid crystal (PDLC: Polymer Dispersed Liquid Crystal) has been proposed (Patent Document 2).

  FIG. 3 is a schematic cross-sectional view showing the structure and behavior of a normal mode light control film 10A including a PNLC light control layer 3A. In the PNLC type, the liquid crystal molecules 5 are arranged in voids formed inside a three-dimensional network structure called a polymer network 4. FIG. 4 is a schematic cross-sectional view showing the structure and behavior of a normal mode light control film 10B including a PDLC type light control layer 3B. In the PDLC type, the liquid crystal material 7 including the liquid crystal molecules 8 is dispersedly arranged in the polymer matrix 6.

  FIGS. 3 (a) and 4 (a) show the PNLC type and PDLC type, respectively, when the AC power supply 11 is turned off. Since the liquid crystal molecules 5 and 8 are randomly arranged, the incident light 21 is high. Multiple scattering occurs at the interface between the molecule and the liquid crystal, and the scattered light 22 becomes noticeable and becomes in a high haze state and becomes white turbid. 3 (b) and 4 (b) are the PNLC type and PDLC type, respectively, when the AC power supply 11 is on, and the liquid crystal molecules 5 and 8 are aligned along the electric field, so that there is no light scattering and transparency. Low haze state.

  FIG. 5 is a schematic cross-sectional view showing the structure and behavior of a reverse mode light control film 20A including a PNLC light control layer 3A. The reverse mode light control film 20A includes alignment films 9a and 9b between the light control layer 3A and the transparent electrodes 2a and 2b on both sides of the light control layer 3A. The alignment films 9a and 9b are so-called vertical alignment films, and when no voltage is applied to the light control layer 3A (FIG. 5A), the longitudinal direction of the liquid crystal molecules 5 is the normal direction of the alignment films 9a and 9b. The liquid crystal molecules are aligned so that For this reason, when a voltage is not applied to the light control layer 3A, it becomes a low haze state and transparency becomes high. On the other hand, when a voltage is applied to the light control layer 3A (FIG. 5 (b)), the orientation of the liquid crystal molecules becomes irregular and becomes a high haze state and becomes clouded.

The structure and behavior of the reverse mode light control film 20B (FIG. 2) including the PDLC light control layer 3B are also the same as those in the case of the PNLC type in FIG.

  As a first characteristic required for a transparent conductive film to be a transparent electrode used for a light control film, a pure water contact angle is low. The lower the pure water contact angle, the better the wettability, and it will not repel the light control layer (liquid crystal) or the alignment film coated on the transparent conductive film, and the adhesion will also increase.

  On the other hand, the structure of the power feeding part in a general light control film is as shown in FIG. 7 (for example, Patent Document 3. FIG. 7 shows the case where there is no alignment film). -1, the transparent conductive film 52-1, and the light control layer 53 are cut out, and the conductive paste 61 applied on the transparent conductive film 52-2 exposed at the end of the light control film 50, and the conductive paste 61 A pin connector 62 that is crimped to the upper side is provided. The pin connector 62 includes an extension part 62a, and a lead wire 64 is connected to the extension part 62a by a solder 63 to form a wiring part. Here, as the pure water contact angle of the transparent conductive film 52-2 is lowered, the adhesiveness of the conductive paste 61 is also improved.

  In general, the power feeding portion structure as described above is formed after the light control film is configured. That is, after the light control layer is sandwiched between a pair of transparent conductive films on a transparent base material, the transparent conductive film 52-2 on one side is exposed in the manner of partially cutting off and disassembling the end portion. A conductive paste or the like is laminated on the substrate, and a wiring portion is formed thereon. Next, a power feeding portion based on the upper transparent base material 51-1 and the transparent conductive film 52-1 is similarly formed at the opposite end portion. In this way, it is possible to apply a voltage to the light control layer using the transparent electrode as the drive electrode from the power feeding portions formed on both sides.

  As described above, since the power feeding unit structure is formed by partially dismantling the light control film, first, the upper and lower one sides of the paired transparent base material and the transparent conductive film are peeled off. There is a need to. Even after the transparent substrate and the transparent conductive film on one side are peeled off, if the light control layer (liquid crystal) or alignment film that is an insulating material remains on the transparent conductive film on the opposite side, the conductivity is hindered. It is necessary to remove the liquid crystal and the alignment film with an organic solvent or the like. Then, solvent resistance is mentioned as the 2nd characteristic required for a transparent conductive film. If the solvent resistance of the transparent conductive film is low, the transparent conductive film is dissolved and detached by the solvent, and the conductivity is lowered. In addition, when the liquid crystal or the alignment film is applied, the transparent conductive film may be dissolved and separated by the solvent in the liquid crystal or the alignment coating liquid, and the conductivity may be lowered.

US Pat. No. 5,304,323 US Pat. No. 4,688,900 Japanese Utility Model Publication No. 6-37395 Japanese Patent No. 5672813 JP 2014-055323 A Japanese Patent Laying-Open No. 2015-215418

  Generally, ITO (indium tin oxide) is used as the transparent conductive film. ITO has high solvent resistance, but has a large pure water contact angle and poor wettability. Moreover, since flexibility is inferior, there also exists a problem that the use to a curved surface shape is difficult. In Patent Document 4, the contact angle of pure water is lowered by performing hydrophilic treatment such as atmospheric pressure plasma and ozone on the ITO surface, but there is a problem that the number of processes increases. In addition, a technique using a conductive polymer, a metal nanowire (Patent Document 5), or a carbon nanotube (Patent Document 6) as a transparent conductive film is also known. In this case, the contact angle with pure water is low and there is no problem with wettability. However, there was a problem that the solvent resistance was poor.

  The present invention has been made to solve the above problems, and in a light control film using a transmission-scattering light control layer such as a PNLC type or a PDLC type, a liquid crystal without performing a hydrophilic treatment, Provided are a light control film comprising a transparent conductive film having sufficient wettability, adhesion and solvent resistance to form an alignment film and a conductive paste for power feeding, and a light control device and a screen using the light control film It is intended to do.

In order to solve the above-described problem, the invention described in claim 1 includes a light control layer, a transparent electrode made of a transparent conductive film on both sides of the light control layer, and a transparent base material in this order. Comprising a light control film capable of switching two or more types of haze according to a voltage applied to the light control layer through the transparent electrode,
The transparent conductive film includes a conductive material and a polymerizable resin,
And the pure water contact angle of the transparent conductive film is 5 to 80 °,
And the transparent conductive film, in which the surface resistance of the laden nonwoven organic solvent was reciprocated 10 times at 200 g / cm ² load area has a light control film, characterized in that it is 300 [Omega / □ or less .

  The invention described in claim 2 is characterized in that the conductive material is one or more selected from a π-conjugated conductive polymer containing a dopant, metal nanowires, and carbon nanotubes. This is a light control film.

  The invention according to claim 3 is the light control film according to claim 2, wherein the π-conjugated conductive polymer containing the dopant is polythiophene-based PEDOT / PSS.

  The invention according to claim 4 is the light control film according to claim 2, wherein the metal nanowire is a silver nanowire.

  The invention described in claim 5 is the light control film according to any one of claims 1 to 4, wherein the polymerizable resin is pentaerythritol triacrylate (PETA).

  Invention of Claim 6 equips the interlayer of the said light control layer and the said transparent electrode of the surface of the both sides of the said light control layer with any one of Claims 1-5 characterized by the above-mentioned. This is a light control film.

  The invention according to claim 7 is the light control film according to any one of claims 1 to 6, wherein the organic solvent is methyl ethyl ketone (MEK).

  Invention of Claim 8 is equipped with the light control film in any one of Claims 1-7, The alternating current power supply which can apply a voltage to the said transparent electrode in this light control film, and the said alternating current to the said transparent electrode The light control device includes a switch for switching whether to apply a voltage of a power supply.

  The invention according to claim 9 comprises the light control device according to claim 8, and a transparent glass is formed on the transparent substrate on at least one surface of the light control device via a transparent adhesive layer. It is made into the screen characterized by providing.

According to the present invention, a light control layer, a transparent electrode made of a transparent conductive film on both sides of the light control layer, and a transparent base material are provided in this order, and the transparent conductive film includes a conductive material and a polymerizable resin. And the pure water contact angle of the transparent conductive film is 5 to 80 °, and the surface resistance value of the region of the transparent conductive film in which the nonwoven fabric containing the organic solvent is reciprocated 10 times at a load of 200 g / cm ² Since the light control film has a resistance of 300Ω / □ or less, it has sufficient wettability, adhesion, and solvent resistance to form a liquid crystal, an alignment film, and a conductive paste for power feeding without performing a hydrophilic treatment. The light control film provided with the transparent conductive film, the light control apparatus using this light control film, and a screen can be provided.

It is a schematic cross section which shows the layer structure of the light control film of a normal mode. It is a schematic cross section which shows the layer structure of the light control film of a reverse mode. It is a schematic cross section which shows the structure and behavior of a normal mode light control film provided with a PNLC type light control layer. (A) When power is off (b) When power is on. It is a schematic cross section which shows the structure and behavior of a normal mode light control film provided with a PDLC type light control layer. (A) When power is off (b) When power is on. It is a schematic cross section which shows the structure and behavior of a reverse mode light control film provided with a PNLC type light control layer. (A) When power is off (b) When power is on. It is a model side view which shows the structural example of the screen using the light modulation apparatus of this invention. It is a schematic cross section which shows the structure of the electric power feeding part in a general light control film.

  Hereinafter, the light control film which concerns on embodiment of this invention, the light control apparatus using the same, and a screen are demonstrated. In addition, the same code | symbol is attached | subjected about the same component unless there is a reason for convenience, and the overlapping description is abbreviate | omitted. Also, in the drawings used in the following description, in order to make the features easy to understand, the portions that become the features may be shown in an enlarged manner, and the dimensional ratios of the respective constituent elements are not the same as the actual ones.

(First embodiment)
The light control film which concerns on the 1st Embodiment of this invention is embodiment which concerns on normal mode, and the light control film (10A or 10B) has the layer structure shown in FIG. It is the same as the layer structure of the light control film. In this configuration, a voltage can be applied to the light control layer (3A or 3B) through the transparent electrodes 2a and 2b, and two or more types can be used in the direction of decreasing the haze of the light control film (10A or 10B) as the voltage is increased. Can be switched. Here, the reason for the two or more types is that by changing the effective voltage in addition to turning on and off the AC power supply, the degree of light transmission and scattering can be changed, and the haze can be changed in various ways. Because.

(Second Embodiment)
The light control film which concerns on the 2nd Embodiment of this invention is embodiment which concerns on reverse mode, and the light control film (20A or 20B) has the layer structure shown in FIG. 2, and the light control layer (3A) Or 3B) and the transparent electrodes 2a and 2b on both sides of the light control layer are provided with alignment films 9a and 9b, which are the same as the layer structure of a conventional reverse mode light control film. In this configuration, a voltage can be applied to the light control layer (3A or 3B) through the transparent electrodes 2a and 2b, and the haze of the light control film (20A or 20B) increases in two or more types as the voltage is increased. Can be switched. The reason why there are two or more types is the same as in the normal mode.

(Characteristics of transparent conductive film common to the first and second embodiments)
The transparent conductive film used as the transparent electrodes 2a and 2b used in the light control films according to the first and second embodiments of the present invention includes a conductive material and a polymerizable resin, and a pure water contact angle of the transparent conductive film. Is a surface resistance value of 300 Ω / □ or less in a region obtained by reciprocating a nonwoven fabric containing an organic solvent 10 times with a load of 200 g / cm ^{2 at a} load of 200 g / cm ² .

  The organic solvent used above is preferably a ketone solvent, an alcohol solvent, or an amide solvent. The ketone solvent is methyl ethyl ketone, the alcohol solvent is methanol, and the amide solvent is N-. Particularly preferred is methyl-2-pyrrolidone.

  In the above, “surface resistance” is an electrical resistance per unit area, and is also called “sheet resistance” or “surface resistivity”, and the unit is Ω / □ or Ω / sq. (Sq. Means square). The surface resistance can be measured with a commercially available surface resistance meter.

  The conductive material contained in the transparent conductive film used in the light control film of the present invention is a kind or plural kinds selected from a π-conjugated conductive polymer containing a dopant, a metal nanowire, and a carbon nanotube because it exhibits high conductivity. Preferably there is.

  Examples of the π-conjugated conductive polymer include polyethylene dioxythiophene, polyacetylene, polydiacetylene, polyaniline, polyparaphenylene, polyparaphenylene vinylene, polythiophene, polyfuran, polypyrrole, polyphenylene sulfide, polypyridyl vinylene, and polyazine. be able to. These conductive polymers may be used alone or in combination of two or more according to the purpose.

  The π-conjugated polymer alone does not exhibit electrical conductivity, and by adding a dopant, a positive or negative charge may be imparted to the π-conjugated polymer and may have electrical conductivity. Therefore, it is preferable to add a dopant.

  A material in which π-conjugated polymer is polyethylenedioxythiophene and polystyrenesulfonic acid is added as a dopant from the viewpoint of dispersibility, that is, a material obtained by polymerizing ethylenedioxythiophene (EDOT) monomer under polystyrenesulfonic acid (PSS) is It is called polystyrene sulfonate-doped polyethylene dioxythiophene (PEDOT / PSS) and is particularly preferable as a conductive material contained in the transparent conductive film used in the light control film of the present invention.

  In general, a metal nanowire refers to a linear structure having a metal element as a main constituent element and having a diameter from the atomic scale to the nm size. As the metal element, at least one metal selected from noble metals such as silver, iron, cobalt, copper, and tin is preferable, but it has particularly high conductivity and low reflectivity in visible light. Silver nanowires are preferred. The silver nanowire is manufactured by a polyol method, a template method, an electrochemical method, or the like.

The polymerizable resin contained in the transparent conductive film used in the light control film of the present invention has the following chemical structural formula 1.
The polymer is preferably a polymer of at least one compound having a structure represented by: In chemical structural formula 1, X represents a single bond, —O—, —COO—, —OCO—, —CONR ³ — or —NHCO—, and R ¹ and R ³ are each independently In addition, hydrogen, an arbitrary hydrogen that may be substituted with a hydroxyl group, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 1 to 18 carbon atoms, or an arbitrary hydrogen that is optionally substituted with a methyl group 6-18 aryl group, C7-18 aralkyl group, C3-18 heterocyclic group, C3-18 alicyclic hydrocarbon group, polyethylene oxide group having 2-20 polymerization degree , Selected from the group consisting of a polypropylene oxide group having a degree of polymerization of 2 to 20, and a glycidyl group, R ² represents hydrogen or methyl. R ¹ and R ³ may be bonded via ether oxygen.

Among the compounds represented by the chemical structural formula 1, pentaerythritol triacrylate (PETA) is particularly preferable. The chemical structural formula of PETA is shown below.

  The effectiveness of the pure water contact angle and the surface resistance defined by the transparent conductive film used in the light control film of the present invention, and the preferred materials of the conductive material and polymerizable resin contained in the transparent conductive film are shown in the Examples.

(Other components)
Hereinafter, elements other than the transparent conductive film constituting the light control film of the present invention will be described.
As a transparent base material, a polyethylene terephthalate film, a polycarbonate film, etc. having a film thickness of 20 μm or more and 100 μm or less in order to maintain chemical and physical strength, sufficient hardness and durability, and high transparency Is particularly preferred.

  The light control layer in the light control film of the present invention is a liquid crystal molecule disposed in a void formed inside a polymer network having a three-dimensional network structure, or a liquid crystal material dispersed in a polymer matrix. It is preferable that the liquid crystal molecule contained is included. Therefore, a PNLC-type and PDLC-type polymer liquid crystal composite film can be used as the light control layer.

  The thickness of the light control layer in the light control film of the present invention is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 25 μm or less. When the thickness of the light control layer is less than 5 μm, there is a tendency that a short circuit is likely to occur, and the lamination with the transparent conductive film tends to be difficult. When the thickness exceeds 50 μm, the responsiveness decreases.

  As the alignment film used in the second embodiment, a known material such as polyimide or polyvinyl alcohol can be used. The alignment film may be rubbed or may not be rubbed.

(Light control device of the present invention)
A light control device of the present invention includes a light control film of the present invention, and includes a power source capable of applying a voltage to a transparent electrode and a switch for switching whether to apply a voltage from the AC power source to the transparent electrode. It is an optical device. Therefore, a basic form is equivalent to the form which connected the light control film and AC power supply 11 shown in FIGS. 3-5 via a switch. The AC power source is preferably a variable power source that can change its effective voltage. This is because the degree of light transmission / scattering can be controlled and the haze can be varied in various ways as described above.

(Screen of the present invention)
The screen of this invention is a screen provided with the light control apparatus of the said this invention, and transparent glass on the transparent base material of the at least one surface of this light control apparatus through a transparent contact bonding layer. In FIG. 6, the form provided with transparent glass 42a, 42b on the transparent base material 1a, 1b of the both surfaces of the light control apparatus 30 through the transparent contact bonding layers 41a, 41b is shown.

  In the screen of the present invention, when the light control film becomes transparent by switching the power source, it becomes transparent glass and the other side of the glass can be visually recognized. In addition, when it becomes cloudy and opaque, it functions as a screen for visually recognizing the image projected on the glass. Moreover, by using a variable power source, an intermediate state between them can be created.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Contact angle, wettability, adhesion, solvent resistance (surface resistance), preparation of samples for flexibility evaluation)
Each transparent conductive film of an Example and a comparative example was formed on the PET film (film thickness 50 micrometers) as a transparent base material as follows, and the sample of each transparent conductive film was produced.

  Examples 1 to 3 and 7 and Comparative Examples 1 and 2 were prepared and evaluated for a normal mode light control film, and Examples 4 to 6 and Comparative Examples 3 and 4 were for a reverse mode light control film. Although it is preparation and evaluation, the difference between the normal mode light control film and the reverse mode light control film is only whether or not the alignment film is provided between the light control layer and the transparent electrode. Therefore, as the transparent conductive film to be a transparent electrode, Examples 1 and 4, Examples 2 and 5, Examples 3 and 6, Comparative Examples 1 and 3, and Comparative Examples 2 and 4 were produced by the same method. It is.

<Example 1 and Example 4>
In Examples 1 and 4, commercially available PEDOT / PSS was used as the conductive material, pentaerythritol triacrylate (PETA) was used as the polymerizable resin, and 1-hydroxycyclohexyl phenyl ketone (HCPK) was used as the polymerization initiator, and PEDOT / PSS: PETA : HCPK = 40 parts by weight: 57 parts by weight: After 3 parts by weight, the mixture was diluted with ethanol so that the solid content was 2.5 wt% to obtain a coating solution. The prepared coating solution is applied to the substrate by a die coating method so that the film thickness after drying is 250 nm, dried in an oven at 100 ° C. for 2 minutes, and then irradiated with ultraviolet rays (360 mJ / cm ² ) and cured. A transparent conductive film was formed to obtain a transparent conductive film.

<Example 2 and Example 5>
In Examples 2 and 5, a commercially available silver nanowire was further used as the conductive material so that PEDOT / PSS: silver nanowire: PETA: HCPK = 20 parts by weight: 20 parts by weight: 57 parts by weight: 3 parts by weight. Except for mixing, a transparent conductive film was formed in the same manner as in Example 1 to obtain a transparent conductive film.

<Example 3 and Example 6>
In Examples 3 and 6, a commercially available carbon nanotube (CNT) is used as the conductive material, and PEDOT / PSS: CNT: PETA: HCPK = 12 parts by weight: 28 parts by weight: 57 parts by weight: 3 parts by weight. A transparent conductive film was formed in the same manner as in Example 1 except that the mixture was mixed as described above to obtain a transparent conductive film.

<Example 7>
Using Mega-Face F477 (manufactured by DIC Corporation) as an additive, PEDOT / PSS: PETA: HCPK: F477 = 40 parts by weight: 57 parts by weight: 3 parts by weight: 0.01 parts by weight Except for the above, a transparent conductive film was formed in the same manner as in Example 1 to obtain a transparent conductive film.

<Comparative Examples 1 and 3>
An ITO single layer film was formed by sputtering to a thickness of 20 nm to form a transparent conductive film.

<Comparative Examples 2 and 4>
The same PEDOT / PSS coating solution as in Example 1 was prepared, applied to the substrate by a die coating method so that the film thickness after drying was 250 nm, and dried in an oven at 100 ° C. for 2 minutes to form a transparent conductive film And a transparent conductive film was obtained.

(Measurement method of contact angle)
Using a contact angle meter (CA-X type manufactured by Kyowa Interface Science Co., Ltd.), a droplet having a diameter of 1.8 mm is formed on the needle tip in a dry state (20 ° C.-65% RH), and these are formed on the surface of the sample (solid) Drops were made in contact with. The contact angle is an angle formed by a tangent to the liquid surface at a point where the solid and the liquid are in contact with the solid surface, and is defined as an angle on the side including the liquid. Distilled water was used as the liquid.

(Wetability evaluation method)
In the case of the first embodiment (normal mode), when the light control layer was applied onto the transparent conductive film and when the conductive paste was applied, the repellency was confirmed visually. In the case of the second embodiment (reverse mode), when the liquid crystal is applied on the transparent conductive film or the alignment film, when the alignment film is applied on the transparent conductive film, or when the conductive paste is applied. In addition, the repellency was confirmed visually. When repelling was not confirmed, the wettability was “good”, and when repelling was confirmed, poor wettability “×”.

(Adhesion evaluation method)
In the case of 1st Embodiment (normal mode), when the light control layer was coated on the transparent conductive film, and when the electrically conductive paste was apply | coated, the adhesiveness test was done, respectively. In the case of the second embodiment (reverse mode), when the liquid crystal is applied on the transparent conductive film or the alignment film, when the alignment film is applied on the transparent conductive film, or when the conductive paste is applied. Each was subjected to an adhesion test. The adhesion test was performed by a cross-cut peel test. The case where there was no peeling was regarded as “good” in the adhesion, and the case where there was peeling was regarded as “poor” in adhesion.

(Solvent resistance evaluation (surface resistance value measurement) method)
Except for Comparative Examples 1 and 3 in which ITO is a transparent conductive film, for Examples and Comparative Samples containing at least PEDOT / PSS as the conductive material of the transparent conductive film, methyl ethyl ketone (MEK) of the transparent conductive film is used. The surface resistance value of the region where the contained nonwoven fabric was reciprocated 10 times with a load of 200 g / cm ² was measured using a commercially available surface resistance meter (trade name: Loresta, manufactured by Mitsubishi Chemical). About the sample of Comparative Examples 1 and 3 which uses ITO as a transparent conductive film, it carried out similarly using the nonwoven fabric containing methanol.

(Measurement and evaluation method of flexibility)
It was measured by a cylindrical mandrel method using a bending tester (cylindrical mandrel bending tester, manufactured by Allgood) in accordance with JIS K5600-5-1. The measured value represents the diameter of the lower limit mandrel at which no abnormalities such as cracks and peeling are observed when observed visually and with an optical microscope. Therefore, it shows that it is excellent in a flexibility, so that a numerical value is small.

(Preparation of dimming module for voltage drive evaluation in normal mode)
Prepare two transparent conductive films obtained above, laminate a PNLC-type light control layer on the transparent conductive film side of one film, and further turn the other film so that the transparent conductive film side is the light control layer side And a light control film was produced. Moreover, the obtained light control film was cut | disconnected to 10 cm x 10 cm, one transparent conductive film of the range of 1 cm was cut off from the film both ends, and the light control layer was exposed. Next, the exposed light control layer was wiped with a nonwoven fabric impregnated with a solvent (MEK for Examples 1-3, 7 and Comparative Example 2 and methanol for Comparative Example 1), and the other transparent conductive film was exposed. I let you. Then, the electrically conductive paste was apply | coated to the exposed transparent conductive film, and the pin connector was crimped | bonded to the upper side of the electrically conductive paste. Furthermore, the light control module was produced by soldering a lead wire to the extension part of a pin connector.

(Production of dimming module for voltage drive evaluation in reverse mode)
Two pieces of each of the transparent conductive films obtained above were prepared, and polyimide having a thickness of 100 nm was applied and formed as an alignment film on the transparent conductive film of each film. Then, the PNLC type light control layer was laminated | stacked on the orientation film side of one film, and also the other film was laminated | stacked so that the orientation film side might become the light control layer side, and produced the light control film. Moreover, the obtained light control film was cut | disconnected to 10 cm x 10 cm, one transparent conductive film and alignment film of the range of 1 cm were cut off from the film both ends, and the light control layer was exposed. Next, the exposed light control layer is wiped with a nonwoven fabric impregnated with a solvent (MEK in Examples 4 to 6 and Comparative Example 4 and methanol in Comparative Example 3), and the other transparent conductive film is exposed. It was. Then, the electrically conductive paste was apply | coated to the exposed transparent conductive film, and the pin connector was crimped | bonded to the upper side of the electrically conductive paste. Furthermore, the light control module was produced by soldering a lead wire to the extension part of a pin connector.

(Voltage drive evaluation method)
A voltage of 100 V was applied to the dimming module to check whether the dimming function was driven. The case where it was driven was “◯”, and the case where it was not driven was “x”.

<Evaluation results>
Table 1 summarizes sample conditions and evaluation results. In Examples 1 to 7, even if the conductive material of the transparent conductive film is any of PEDOT / PSS, PEDOT / PSS + silver nanowire, and PEDOT / PSS + CNT, by using PETA as the polymerizable resin, pure water contact angle Was 5 to 80 °, and the wettability and adhesion of the liquid crystal and the conductive paste were good. In Examples 4 to 6 having an alignment film, the wettability and adhesion of the alignment film were also good. Since each of these parts was formed satisfactorily and the solvent resistance of the transparent conductive film was high (no increase in surface resistance value), in Examples 1 to 7, the voltage drive was also good. Moreover, in Examples 1-7, the flexibility (flexibility) was also as favorable as 10 mmphi.

  On the other hand, in Comparative Examples 1 and 3 using ITO as a transparent conductive film, although the solvent resistance is high, the contact angle of pure water is as large as 100 ° or more. The film also deteriorated in wettability and adhesion. Flexibility (flexibility) was also inferior to the examples. Further, in Comparative Examples 2 and 4 where the conductive material of the transparent conductive film is PEDOT / PSS and does not have a polymerizable resin, although the pure water contact angle is as small as 20 °, the solvent resistance is low and the conductive paste is wet. And adhesion deteriorated. From these things, in Comparative Examples 1-4, the voltage drive became defective.

  The light control film of the present invention can be applied as a window glass, an exhibition window, a partition screen, or a screen capable of blocking the visual field. Moreover, since the private space and the public space are separated, it can also be used as a sunroof or a sun visor for automobiles. It can also be applied to display applications such as display boards and projections.

1a, 1b ... transparent substrate, 2a, 2b ... transparent electrode 3A ... light control layer (PNLC type), 3B ... light control layer (PDLC type)
4 .... Polymer network, 5,8 ... Liquid crystal molecule 6 .... Polymer matrix, 7 .... Liquid crystal materials 9a, 9b ... Alignment film 10A ... Light control film (PNLC type, normal mode)
10B: Light control film (PDLC type, normal mode)
11: AC power supply, 12: Switch 20A ... Light control film (PNLC type, reverse mode)
20B ... ・ Light control film (PDLC type, reverse mode)
21... Incident light, 22... Scattered light, 23... Transmitted light 30... Dimmer, 40. Adhesive layer, 42a, 42b ... transparent glass 43 ... projector, 44 ... projection light 50 ... light control film, 51-1, 51-2 ... transparent substrate 52-1, 52-2... Transparent conductive film 53... Dimming layer 61... Conductive paste 62 62 Pin connector 62 a. ..Solder, 64 ... Lead wire

Claims (9)

A light control layer, a transparent electrode made of a transparent conductive film on both sides of the light control layer, and a transparent base material are provided in this order, and a haze is applied according to a voltage applied to the light control layer through the transparent electrode. Is a light control film that can be switched between two or more types,
The transparent conductive film includes a conductive material and a polymerizable resin,
And the pure water contact angle of the transparent conductive film is 5 to 80 °,
And the surface resistance value of the area | region which reciprocated the nonwoven fabric containing the organic solvent of the said transparent conductive film 10 times by 200 g / cm < ² > load is 300 ohms / square or less, The light control film characterized by the above-mentioned.   The light control film according to claim 1, wherein the conductive material is one or a plurality selected from a π-conjugated conductive polymer containing a dopant, metal nanowires, and carbon nanotubes.   The light control film according to claim 2, wherein the π-conjugated conductive polymer containing the dopant is polythiophene-based PEDOT / PSS.   The light control film according to claim 2, wherein the metal nanowire is a silver nanowire.   The light control film according to claim 1, wherein the polymerizable resin is pentaerythritol triacrylate (PETA).   The light control film according to claim 1, further comprising an alignment film between the light control layer and the transparent electrode on both sides of the light control layer.   The light control film according to claim 1, wherein the organic solvent is methyl ethyl ketone (MEK).   An AC power supply comprising the light control film according to claim 1 and capable of applying a voltage to the transparent electrode in the light control film, and whether to apply the voltage of the AC power supply to the transparent electrode. A dimming device comprising a switch for switching between.   A screen comprising the light control device according to claim 8, wherein a transparent glass is provided on the transparent substrate on at least one surface of the light control device via a transparent adhesive layer.