CN117944345A - Transparent conductive film and liquid crystal member - Google Patents

Transparent conductive film and liquid crystal member Download PDF

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Publication number
CN117944345A
CN117944345A CN202311372112.5A CN202311372112A CN117944345A CN 117944345 A CN117944345 A CN 117944345A CN 202311372112 A CN202311372112 A CN 202311372112A CN 117944345 A CN117944345 A CN 117944345A
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Prior art keywords
transparent conductive
liquid crystal
conductive film
conductive layer
layer
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Inventor
河野文彦
野口光贵
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Nitto Denko Corp
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Nitto Denko Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/14—Non-insulated conductors or conductive bodies characterised by their form comprising conductive layers or films on insulating-supports
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1343—Electrodes
    • G02F1/13439—Electrodes characterised by their electrical, optical, physical properties; materials therefor; method of making
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/12—Layered products comprising a layer of synthetic resin next to a fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B32B27/325—Layered products comprising a layer of synthetic resin comprising polyolefins comprising polycycloolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B32B5/028—Net structure, e.g. spaced apart filaments bonded at the crossing points
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/10—Inorganic fibres
    • B32B2262/103—Metal fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
    • B32B2307/202—Conductive
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/412—Transparent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites

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  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Nonlinear Science (AREA)
  • Dispersion Chemistry (AREA)
  • Mathematical Physics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Non-Insulated Conductors (AREA)
  • Liquid Crystal (AREA)
  • Laminated Bodies (AREA)

Abstract

Provided is a transparent conductive film which contains metal nanowires and has low moisture permeability. The transparent conductive film of the present invention comprises: the transparent conductive layer comprises metal nanowires, and a substrate and a transparent conductive layer arranged on at least one side of the substrate, wherein the moisture permeability of the substrate is below 30g/m 2 & 24h at a temperature of 65 ℃ and a humidity of 90%. In one embodiment, the base material is made of a cycloolefin resin.

Description

Transparent conductive film and liquid crystal member
Technical Field
The present invention relates to a transparent conductive film and a liquid crystal member.
Background
Conventionally, a light control film using a light scattering effect of a complex of a polymer and a liquid crystal material has been developed. In such a light control film, since the liquid crystal material is phase-separated or dispersed in the polymer matrix, the refractive index of the polymer and the liquid crystal material is matched, and the alignment of the liquid crystal material is changed by applying a voltage to the composite, whereby the transmission mode for transmitting light and the scattering mode for scattering light can be controlled. In order to realize such driving, the light control film is generally constituted by sandwiching a light control layer including the composite body between transparent conductive films.
On the other hand, as a transparent conductive film, a film having a conductive layer including metal nanowires has been studied. When such a transparent conductive film is used for the light control film, flexibility can be improved. The metal nanowires are wire-like conductive substances having a diameter of nanometer size. In a transparent conductive film made of metal nanowires, the metal nanowires form a grid, and a good conductive path is formed by a small number of metal nanowires, and openings are formed in gaps of the grid, so that high light transmittance can be achieved. Although the transparent conductive film containing the metal nanowires having excellent characteristics as described above has a problem in terms of moisture permeability, it is disadvantageous in terms of the reliability of humidification of the liquid crystal layer when applied to the liquid crystal layer typified by the light control layer.
Prior art literature
Patent literature
Patent document 1: japanese patent laid-open No. 2013-148687
Disclosure of Invention
Problems to be solved by the invention
The present invention has been made to solve the above-described problems, and a main object of the present invention is to provide a transparent conductive film containing metal nanowires and having low moisture permeability.
Means for solving the problems
The transparent conductive film of the present invention comprises: the transparent conductive layer comprises metal nanowires, and the transparent conductive layer is arranged on at least one side of the substrate, the moisture permeability of the substrate is below 30g/m 2.24 h at the temperature of 65 ℃ and the humidity of 90%.
In one embodiment, the base material is made of a cycloolefin resin.
In one embodiment, the transparent conductive layer further comprises a polymer matrix.
According to another aspect of the present invention, a liquid crystal member is provided. The liquid crystal member includes the transparent conductive film and the liquid crystal layer.
In one embodiment, transparent conductive films are disposed on both sides of the liquid crystal layer.
In one embodiment, the liquid crystal layer is a light modulation layer.
Effects of the invention
According to the embodiment of the present invention, a transparent conductive film including metal nanowires and having low moisture permeability can be provided.
Drawings
Fig. 1 is a schematic cross-sectional view of a transparent conductive film according to an embodiment of the present invention.
Fig. 2 is a schematic cross-sectional view of a liquid crystal member according to an embodiment of the present invention.
Symbol description
10. Substrate material
20. Transparent conductive layer
100. Transparent conductive film
200. Liquid crystal component
Detailed Description
Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.
A. transparent conductive film
Fig. 1 is a schematic cross-sectional view of a transparent conductive film according to an embodiment of the present invention. The transparent conductive film 100 includes a substrate 10 and a transparent conductive layer 20 disposed on at least one side of the substrate 10. The transparent conductive layer comprises metal nanowires.
The surface resistance value of the transparent conductive film is preferably 0.1 Ω/≡to 1000 Ω/≡, more preferably 0.5 Ω/≡to 300 Ω/≡, and particularly preferably 1 Ω/≡to 200 Ω/≡. The surface resistance value can be measured by using "automatic resistivity measuring system MCP-S620 type MCP-S521 type" from Mitsubishi CHEMICAL ANALYTECH.
The haze value of the transparent conductive film is preferably 20% or less, more preferably 10% or less, and still more preferably 0.1% to 5%. If the content is within this range, for example, a transparent conductive film preferable for use as a transparent electrode can be obtained.
The total light transmittance of the transparent conductive film is preferably 30% or more, more preferably 35% or more, and particularly preferably 40% or more. If the content is within this range, for example, a transparent conductive film preferable for use as a transparent electrode can be obtained.
A-1 substrate
The moisture permeability of the substrate is below 30g/m 2.24 hours at 65 ℃ and 90% humidity. If a substrate having such a low humidity range is used, the reliability of humidification of the liquid crystal layer can be improved when used in combination with the liquid crystal layer. The moisture permeability of the substrate is preferably 28g/m 2.24 hours or less, more preferably 24g/m 2.24 hours or less at a temperature of 65℃and a humidity of 90%. If the range is such, the above effect becomes remarkable. The lower the moisture permeability of the substrate, the more preferable, but the lower limit thereof is, for example, 1g/m 2.24 hours at a temperature of 65℃and a humidity of 90%. The moisture permeability can be determined according to the moisture permeability test (cup method) of JIS Z0208.
The moisture permeability of the substrate is preferably 100g/m 2.multidot.24 hours or less, more preferably 80g/m 2.multidot.24 hours or less, and still more preferably 60g/m 2.multidot.24 hours or less at a temperature of 85 ℃ and a humidity of 85%. If the range is such, the above effect becomes remarkable. The lower limit of the moisture permeability of the substrate is, for example, 2g/m 2.24 hours at a temperature of 85℃and a humidity of 85%.
Any suitable resin film may be used as the base material as long as the above-mentioned moisture permeability (at 65 ℃ C. And 90% humidity) can be obtained. The resin film is preferably a resin film having excellent transparency in addition to the above-described desired characteristics. Specific examples of the constituent materials include cycloolefin resins, polycarbonate resins, cellulose resins, polyester resins, and acrylic resins. Among them, cycloolefin resins are preferable.
The thickness of the base material is preferably 20 μm to 200. Mu.m, more preferably 30 μm to 150. Mu.m.
The total light transmittance of the base material is preferably 30% or more, more preferably 35% or more, and even more preferably 40% or more. If the content is within this range, for example, a transparent conductive film preferable for use as a transparent electrode can be obtained.
A-2 transparent conductive layer
In one embodiment, the transparent conductive layer comprises metal nanowires and a polymer matrix. When a transparent conductive layer containing metal nanowires is formed, a transparent conductive film having excellent bendability and excellent light transmittance can be obtained. The metal nanowires are protected by the polymer matrix. As a result, corrosion of the metal nanowire can be prevented, and a transparent conductive film having more excellent durability can be obtained.
The thickness of the transparent conductive layer is preferably 10nm to 1000nm, more preferably 20nm to 500nm.
The total light transmittance of the transparent conductive layer is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more.
(Metal nanowire)
The metal nanowire is a conductive substance which is made of metal, needle-like or thread-like in shape and has a nano-size diameter. The metal nanowires may be linear or curved. When a transparent conductive layer made of metal nanowires is used, the metal nanowires are formed in a grid shape, and even a small amount of metal nanowires can form a good conductive path, so that a transparent conductive film having a small resistance can be obtained. Further, the metal nanowires are formed in a grid shape, and the openings are formed in the gaps of the grid, whereby a transparent conductive film having high light transmittance can be obtained.
The ratio of the thickness d to the length L (aspect ratio: L/d) of the metal nanowire is preferably 10 to 100,000, more preferably 50 to 100,000, and particularly preferably 100 to 10,000. If metal nanowires having a large aspect ratio are used, the metal nanowires cross well, and a small amount of metal nanowires can exhibit high conductivity. As a result, a transparent conductive film having high light transmittance can be obtained. In the present specification, the term "thickness of the metal nanowire" refers to a diameter of the metal nanowire when the cross section of the metal nanowire is circular, a minor diameter of the metal nanowire when the metal nanowire is elliptical, and a longest diagonal line when the metal nanowire is polygonal. The thickness and length of the metal nanowires can be confirmed by a scanning electron microscope or a transmission electron microscope.
The thickness of the metal nanowires is preferably less than 500nm, more preferably less than 200nm, particularly preferably 10nm to 100nm, and most preferably 10nm to 50nm. If the amount is within this range, a transparent conductive layer having high light transmittance can be formed.
The length of the metal nanowire is preferably 1 μm to 1000 μm, more preferably 10 μm to 500 μm, and particularly preferably 10 μm to 100 μm. If the amount is within this range, a transparent conductive film having high conductivity can be obtained.
Any suitable metal may be used as the metal constituting the metal nanowire as long as it is a conductive metal. Examples of the metal constituting the metal nanowire include silver, gold, copper, and nickel. Further, a material obtained by subjecting these metals to plating treatment (for example, gold plating treatment) may be used. Among them, silver, copper or gold is preferable from the viewpoint of conductivity, and silver is more preferable.
As a method for producing the metal nanowire, any suitable method can be used. Examples of the method include a method of reducing silver nitrate in a solution, a method of applying a voltage or a current to a surface of a precursor from a tip of a probe, and continuously forming a metal nanowire by drawing the metal nanowire from the tip of the probe. In the method of reducing silver nitrate in a solution, silver nanowires can be synthesized by liquid phase reduction of silver salts such as silver nitrate in the presence of a polyhydric alcohol such as ethylene glycol and polyvinylpyrrolidone. Silver nanowires of uniform size can be mass produced, for example, according to the methods described in cia, y.et., chem. Mate (2002), 14, 4736-4745, xia, y.et., nanoles (2003) 3 (7), 955-960.
The transparent conductive layer containing the metal nanowires can be formed by applying a dispersion liquid in which the metal nanowires are dispersed in a solvent to the substrate, and then drying the applied layer.
Examples of the solvent include water, alcohol solvents, ketone solvents, ether solvents, hydrocarbon solvents, and aromatic solvents. From the viewpoint of reducing environmental load, water is preferably used.
The dispersion concentration of the metal nanowires in the metal nanowire dispersion is preferably 0.1 to 1 wt%. When the amount is within this range, a transparent conductive layer excellent in conductivity and light transmittance can be formed.
The metal nanowire dispersion may further contain any suitable additive according to purposes. Examples of the additive include an anticorrosive material for preventing corrosion of the metal nanowire, a surfactant for preventing aggregation of the metal nanowire, and the like. The kind, number and amount of the additives used may be appropriately set according to the purpose.
Any suitable method can be used for coating the metal nanowire dispersion. Examples of the coating method include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, relief printing, gravure printing, and gravure printing. As a drying method of the coating layer, any suitable drying method (e.g., natural drying, air drying, heat drying) may be employed. For example, in the case of heat drying, the drying temperature is typically 50 to 200 ℃, and the drying time is typically 1 to 10 minutes.
The content ratio of the metal nanowire in the transparent conductive layer is preferably 30 to 90 wt%, more preferably 45 to 80 wt%, based on the total weight of the transparent conductive layer. When the amount is in this range, a transparent conductive film excellent in conductivity and light transmittance can be obtained.
In the case where the metal nanowire is a silver nanowire, the density of the transparent conductive layer is preferably 1.3g/cm 3～10.5g/cm3, more preferably 1.5g/cm 3～3.0g/cm3. When the amount is in this range, a transparent conductive film excellent in conductivity and light transmittance can be obtained.
In one embodiment, the transparent conductive layer is patterned. As a patterning method, any suitable method may be used depending on the form of the transparent conductive layer. The pattern of the transparent conductive layer may have any suitable shape depending on the application. Examples of the pattern include those described in japanese patent application laid-open publication No. 2011-511357, japanese patent application laid-open publication No. 2010-164938, japanese patent application laid-open publication No. 2008-310550, japanese patent application laid-open publication No. 2003-511799, and japanese patent application laid-open publication No. 2010-541109. The transparent conductive layer may be patterned using any suitable method according to the form of the transparent conductive layer after being formed on the transparent substrate.
In one embodiment, the metal nanowires in the transparent conductive layer have a fusion bonded lattice structure. The metal nanowires having the fusion-bonded lattice structure are in a state in which the metal nanowires are fusion-bonded to each other through the joints. If a transparent conductive layer including metal nanowires having a fusion-bonded lattice structure is formed, a transparent conductive film having higher conductivity can be obtained without impeding transparency.
The transparent conductive layer including the metal nanowires having the above-described melt-bonded lattice structure can be formed, for example, by adding an additive for promoting melt-bonding to a metal nanowire dispersion. Examples of the additive include metal halides (e.g., liCl, csCl, naF, naCl, naBr, naI, KCl, mgCl 2、CaCl2、AlCl3, agF, etc.), inorganic acids (e.g., nitric acid, nitrous acid, sulfuric acid, etc.), organic acids (e.g., oxalic acid, citric acid, formic acid, acetic acid, lactic acid, propionic acid, butyric acid, acrylic acid, pyruvic acid, trichloroacetic acid, trifluoroacetic acid, hexane acid, octane acid, decane acid, dodecane (laur) acid, tetradecane (myristic) acid, hexadecane (palmic) acid, octadecane (stearic) acid, 2-ethylbutyric acid, 2-methylhexane acid, 2-ethylhexane acid, 2-propylpentane acid, pivalic acid, neoheptanoic acid, neononanoic acid, neodecanoic acid, etc.), silver salts (e.g., silver nitrate, silver nitrite, silver lactate, silver chloride, silver sulfate, silver oxide, silver acetate, silver chlorate, silver sulfide, etc., silver formate, silver hexane acid, silver octane acid, silver decane acid, silver dodecanoate, silver dodecane acid, silver octadecanoate, silver hexane acid, silver pivalate, silver neoheptanoic acid, silver neodecanoate, neodecanoic acid, etc.), sodium chloride, etc.), and the like (e.g., sodium chloride, etc.). Of these, metal halides are preferred, and NaCl, agF, liF, naBr, or NaF is more preferred. In one embodiment, the transparent conductive layer including the metal nanowire having the above-described melt-bonded lattice structure may be formed by coating a metal nanowire dispersion liquid including the above-described additive and then performing a heat treatment and/or a pressure treatment. The temperature of the heat treatment is, for example, 50℃to 200 ℃.
The transparent conductive layer containing the metal nanowires having the above-described fusion-bonded lattice structure may also be formed by exposing the coating layer of the metal nanowire dispersion to an acyl halide vapor. Examples of the acid halide vapor include HCl, HBr, HI and a mixture thereof.
A metal nanowire having a fusion-bonded lattice structure and a method for producing the same are described in, for example, japanese patent application laid-open No. 2015-530693. The disclosure of this publication is incorporated by reference into the present specification.
(Polymer matrix)
Any suitable polymer may be used as the polymer constituting the polymer matrix. Examples of the polymer include acrylic polymers; polyester polymers such as polyethylene terephthalate; aromatic polymers such as polystyrene, polyvinyltoluene, polyvinylxylene, polyimide, polyamide, and polyamideimide; a polyurethane polymer; an epoxy polymer; a polyolefin polymer; acrylonitrile-butadiene-styrene copolymer (ABS); cellulose; a silicon-based polymer; polyvinyl chloride; a polyacetate; polynorbornene; synthetic rubber; fluorine-based polymers, and the like. Preferably, a curable resin (preferably, an ultraviolet curable resin) composed of a polyfunctional acrylate such as pentaerythritol triacrylate (PETA), neopentyl glycol diacrylate (NPGDA), dipentaerythritol hexaacrylate (DPHA), dipentaerythritol pentaacrylate (DPPA), or trimethylolpropane triacrylate (TMPTA) is used.
The transparent conductive layer can be formed, for example, by coating a composition for forming a conductive layer containing metal nanowires on a substrate and then drying the coated layer.
The composition for forming a conductive layer may contain any suitable solvent in addition to the metal nanowires. The composition for forming a conductive layer can be prepared as a dispersion of metal nanowires. Examples of the solvent include water, alcohol solvents, ketone solvents, ether solvents, hydrocarbon solvents, and aromatic solvents. From the viewpoint of reducing environmental load, water is preferably used. The composition for forming a conductive layer may further contain any suitable additive according to the purpose. Examples of the additive include an anticorrosive material for preventing corrosion of the metal nanowire, a surfactant for preventing aggregation of the metal nanowire, and the like. The kind, number and amount of the additives used may be appropriately set according to the purpose.
The polymer matrix can be formed by applying the composition for forming a conductive layer as described above, drying the composition, applying a polymer solution (polymer composition, monomer composition) onto a layer composed of metal nanowires, and then drying or curing the applied layer of the polymer solution. The transparent conductive layer may be formed using a composition for forming a conductive layer containing a polymer constituting a polymer matrix.
The dispersion concentration of the metal nanowires in the composition for forming a conductive layer is preferably 0.05 to 1 wt%. When the amount is within this range, a transparent conductive layer excellent in conductivity and light transmittance can be formed.
Any suitable method can be used for the application method of the composition for forming a conductive layer. Examples of the coating method include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, relief printing, gravure printing, and gravure printing. As a drying method of the coating layer, any suitable drying method (e.g., natural drying, air drying, heat drying) may be employed. For example, in the case of heat drying, the drying temperature is typically 50℃to 200℃and preferably 80℃to 150 ℃. The drying time is typically 1 to 10 minutes.
The polymer solution contains a polymer constituting the polymer matrix or a precursor of the polymer (a monomer constituting the polymer).
The polymer solution may contain a solvent. Examples of the solvent contained in the polymer solution include alcohol solvents, ketone solvents, tetrahydrofuran, hydrocarbon solvents, and aromatic solvents. Preferably the solvent is volatile. The boiling point of the solvent is preferably 200 ℃ or less, more preferably 150 ℃ or less, and still more preferably 100 ℃ or less.
B. LCD component (light adjusting film)
Fig. 2 is a schematic cross-sectional view of a liquid crystal member according to an embodiment of the present invention. The liquid crystal member 200 includes a transparent conductive film 100 and a liquid crystal layer 110. In one embodiment, transparent conductive films 100 are disposed on both sides of the liquid crystal layer 110. The transparent conductive film 100 may be arranged such that the transparent conductive layer 20 becomes the liquid crystal layer 110.
The liquid crystal layer contains a liquid crystal compound. The liquid crystal layer is formed by dispersing a liquid crystal compound in a resin matrix. In one embodiment, the liquid crystal layer may be a dimming layer. In this case, the liquid crystal member may be a light adjusting film. In the light control layer, the transmission mode and the scattering mode can be switched according to whether or not a voltage is applied to change the alignment degree of the liquid crystal compound. In one embodiment, the light transmission mode is set in a state where a voltage is applied, and the light scattering mode (normal mode) is set in a state where no voltage is applied. In this embodiment, the liquid crystal compound is not aligned and becomes a scattering mode when no voltage is applied, and is aligned and becomes a transmissive mode when a voltage is applied. In another embodiment, the scattering mode is set in a state where a voltage is applied, and the transmission mode (reverse mode) is set in a state where no voltage is applied. In this embodiment, the liquid crystal compound is aligned when no voltage is applied, and the aligned liquid crystal compound exhibits substantially the same refractive index as the resin matrix, and becomes a transmissive mode. On the other hand, the alignment of the liquid crystal compound is disturbed by the application of a voltage, and the liquid crystal compound becomes a scattering mode.
Examples of the light control layer include a light control layer containing a polymer dispersed liquid crystal and a light control layer containing a polymer network type liquid crystal. The polymer dispersed liquid crystal has a structure in which the liquid crystal phase separates in the polymer. The polymer network type liquid crystal has a structure in which liquid crystals are dispersed in a polymer network, and the liquid crystals in the polymer network have a continuous phase.
As the liquid crystal compound, any suitable liquid crystal compound that is not polymeric is used. Examples thereof include nematic, smectic, and cholesteric liquid crystal compounds. Since excellent transparency can be achieved in the transmissive mode, a nematic liquid crystal compound is preferably used. Examples of the nematic liquid crystal compound include biphenyl compounds, phenyl benzoate compounds, cyclohexylbenzene compounds, azobenzene oxide compounds, azobenzene compounds, azomethine compounds, terphenyl compounds, biphenyl benzoate compounds, cyclohexylbiphenyl compounds, phenylpyridine compounds, cyclohexylpyrimidine compounds, and cholesterol compounds.
The content of the liquid crystal compound in the light control layer is, for example, 80 wt% or more, preferably 90 wt% to 99 wt%, and more preferably 92 wt% to 98 wt%.
The resin forming the resin matrix constituting the light control layer may be appropriately selected depending on the light transmittance, the refractive index of the liquid crystal compound, and the like. The resin is typically an active energy ray-curable resin, and a liquid crystal polymer, (meth) acrylic resin, silicone resin, epoxy resin, fluorine resin, polyester resin, polyimide resin, or the like can be preferably used.
The content of the resin matrix in the light control layer is 20 wt% or less, preferably 1 wt% to 10 wt%, and more preferably 2 wt% to 8 wt%.
Examples
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The measurement method of each characteristic is as follows. Unless otherwise specified, "parts" and "%" in examples and comparative examples are weight basis.
(1) Moisture permeability
The substrates used in examples and comparative examples were measured for moisture permeability at 65℃and 90% relative humidity according to JIS Z0208. The moisture permeability at a temperature of 85℃and a relative humidity of 85% was measured in the same manner.
(2) Flexibility of
The resistance value after bending the transparent conductive film was measured. An Ag paste was applied to both ends of the transparent conductive film (length 100mm×width 20 mm) in the 1 st conductive layer side in the longitudinal direction to obtain test pieces. The test piece was suspended from a stainless steel round bar (radius: rmm) so that the 1 st conductive layer was outside, and bent 180 ° along the round bar so as to be bent in the longitudinal direction. Then, weights (500 g each) were lowered via jigs at both ends in the longitudinal direction, and held in this state for 10 seconds.
After the above operation, the weight and the jig were removed, and the surface resistance value (resistance value after bending) between Ag paste portions was checked by a tester. The on-state OK is set if the rising rate of the surface resistance value is 20% or less with respect to the surface resistance value before bending, and the on-state NG is set if the rising rate exceeds 20%.
Production example 1 (Synthesis of silver nanowire and preparation of silver nanowire Dispersion)
5Ml of anhydrous ethylene glycol and 0.5ml of an anhydrous ethylene glycol solution of PtCl2 (concentration: 1.5X10 -4 mol/L) were added to a reaction vessel equipped with a stirring device at 160 ℃. After 4 minutes, 2.5ml of an anhydrous ethylene glycol solution (concentration: 0.12 mol/l) of AgNO 3 and 5ml of an anhydrous ethylene glycol solution (concentration: 0.36 mol/l) of polyvinylpyrrolidone (MW: 55000) were simultaneously added dropwise to the resulting solution over 6 minutes. After this dropwise addition, the reaction was carried out for 1 hour or more until AgNO 3 was completely reduced, thereby producing silver nanowires. Next, acetone was added to the reaction mixture containing silver nanowires obtained as described above until the volume of the reaction mixture became 5 times, and the reaction mixture was centrifuged (2000 rpm, 20 minutes) to obtain silver nanowires.
The obtained silver nanowire has a short diameter of 30 nm-40 nm, a long diameter of 30 nm-50 nm and a length of 5 μm-50 μm.
Silver nanowires were dispersed in pure water (concentration: 0.2 wt%), and pentaethylene glycol dodecyl ether (concentration: 0.1 wt%), to prepare silver nanowire dispersion I.
Example 1
(Preparation of composition for Forming transparent conductive layer (PN))
The silver nanowire dispersion was diluted with 25 parts by weight of pure water and 75 parts by weight of the above-mentioned silver nanowire dispersion to prepare a composition (PN) for forming a transparent conductive layer having a solid content concentration of 0.05% by weight.
(Preparation of monomer composition)
1 Part by weight of pentaerythritol triacrylate (trade name "Viscoat #300", manufactured by osaka organic chemical industry Co., ltd.) and 0.2 part by weight of a photopolymerization initiator (trade name "Irgacure907", manufactured by BASF Co., ltd.) were diluted with 80 parts by weight of isopropyl alcohol and 19 parts by weight of diacetone alcohol to obtain a monomer composition having a solid content of 1% by weight.
(Production of transparent conductive film)
Further, the transparent conductive film was obtained by applying the above monomer composition to a coating layer of the transparent conductive layer-forming composition (PN) and drying the same, and then drying the same at 90℃for 1 minute, and then irradiating ultraviolet rays of 300mJ/cm 2 to form a transparent conductive layer.
The obtained transparent conductive film was subjected to the above evaluation. The results are shown in table 1.
Comparative example 1
A transparent conductive film was obtained in the same manner as in example 1, except that a polyethylene terephthalate film (product name "T910E125", thickness 125 μm, manufactured by Mitsubishi Chemical company) was used instead of the cycloolefin resin film. The obtained transparent conductive film was subjected to the above evaluation. The results are shown in table 1.
Comparative example 2
(Light-transmitting substrate)
An organic-inorganic composite material containing a refractive index adjuster (trade name: OPSTAR Z7412, manufactured by Kagaku chemical Co., ltd.) as an organic-inorganic composite component, in which the refractive index of zirconia particles having a median particle diameter of 40nm as an inorganic component was 1.62, was coated on one side of a substrate (polyethylene terephthalate film, manufactured by Mitsubishi Chemical Co., ltd., product name: T910E125, thickness 125 μm) using a gravure coater, and the coating film was dried by heating at 60℃for 1 minute. Thereafter, a hardening treatment was performed by irradiating ultraviolet rays with an accumulated light amount of 250mJ/cm 2 with a high-pressure mercury lamp, thereby forming a refractive index adjusting layer having a thickness of 85nm and a refractive index of 1.62.
(Transparent conductive layer)
In a parallel flat type coiled magnetron sputtering device, a coil type magnetron sputtering device is arranged for 90:10 or 96.7:3.3 weight ratio of sintered body target containing indium oxide and tin oxide. Then, a film was formed by reactive sputtering in an atmosphere of 5.3X10 -1 Pa containing 80% of argon and 20% of oxygen, and a transparent conductive layer having a thickness of 25nm was formed on the refractive index adjusting layer.
TABLE 1

Claims (6)

1. A transparent conductive film is provided with:
Substrate and method for producing the same
A transparent conductive layer disposed on at least one side of the substrate,
The moisture permeability of the base material is below 30g/m 2.24 h at 65 ℃ and 90 percent,
The transparent conductive layer comprises metal nanowires.
2. The transparent conductive film according to claim 1, wherein the base material is composed of a cycloolefin resin.
3. The transparent conductive film of claim 1, wherein the transparent conductive layer further comprises a polymer matrix.
4. A liquid crystal member comprising the transparent conductive film according to any one of claims 1 to 3 and a liquid crystal layer.
5. The liquid crystal member according to claim 4, wherein transparent conductive films are disposed on both sides of the liquid crystal layer.
6. The liquid crystal member according to claim 4, wherein the liquid crystal layer is a dimming layer.
CN202311372112.5A 2022-10-27 2023-10-23 Transparent conductive film and liquid crystal member Pending CN117944345A (en)

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