JP2013089581A - Transparent conductive member - Google Patents

Abstract

The present invention provides a transparent conductive member having excellent transparency and conductivity and having a good appearance.
A transparent conductive member according to the present invention includes a graphene layer, a colored layer that overlaps the graphene layer, and a transparent substrate. The transparent conductive member 1 has a first region 5 composed of a region where the graphene layer 2, the colored layer 3 and the base material 4 overlap each other, and the colored layer 3 and the base material 4 overlap each other. In addition, the graphene layer 2 is formed with a second region 6 made of a non-overlapping region. L ^* difference ΔL ^* , a ^* difference Δa ^* , and b ^* difference Δb ^* between the transmission color of the first region 5 and the transmission color of the second region 6 are expressed by the following formula (1). The relationship shown in is satisfied.
{(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 ≦ 1.2 (1)
[Selection] Figure 1

Description

  The present invention relates to a transparent conductive member having both transparency and conductivity.

  A member having both transparency and conductivity (transparent conductive member) is applied to a transparent electrode, a touch panel component, and the like, and is expected to expand its application. As such a member, a member constituted by depositing ITO on a transparent base material such as a glass base material can be cited as a representative example.

  However, since indium, which is the main component of ITO, is a rare metal, there are problems regarding cost and resource depletion.

On the other hand, in recent years, a graphene sheet has been attracting attention as a material having both high transparency and conductivity. The graphene sheet is a sheet having a thickness of one atom formed by arranging carbon atoms in a hexagonal lattice structure in a planar shape by sp ² bonds, and the electrical resistance value at room temperature is 2/3 that of copper. It is a material excellent in both conductivity and durability that its current density resistance is 100 times or more that of copper.

  Patent Document 1 relates to a method for producing graphene, including a base member, a hydrophilic oxide layer formed on the base member, a hydrophobic metal catalyst layer formed on the oxide layer, and the metal catalyst layer. Preparing a graphene member including a graphene layer formed thereon, providing water to the graphene member, separating the metal catalyst layer from the oxide layer, and removing the metal catalyst layer using an etching method; Is disclosed.

JP2011-63506

  However, although graphene has high transparency, its color is blackish. Therefore, particularly when the graphene layer is patterned, there is a problem that the color of the graphene appears to be uneven in the transparent conductive member, leading to deterioration of the appearance.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide a transparent conductive member having excellent transparency and conductivity and having a good appearance.

The transparent conductive member according to the present invention includes a graphene layer, a colored layer overlapping the graphene layer, and a transparent substrate that supports the graphene layer and the colored layer,
A first region composed of a region where the graphene layer, the colored layer and the substrate overlap, and a second region composed of a region where the colored layer and the substrate overlap and the graphene layer does not overlap And are formed,
L ^* difference ΔL ^* , a ^* difference Δa ^* , and b ^* difference Δb ^* between the transmission color of the first region and the transmission color of the second region are shown in the following formula (1). Satisfy the relationship.
{(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 ≦ 1.2 (1)
In the present invention, the graphene layer is preferably interposed between the base material and the colored layer.

  In the present invention, it is also preferable that the colored layer is interposed between the graphene layer and the substrate.

  According to the present invention, it is possible to obtain a transparent conductive member that has both excellent transparency and conductivity, and that has a good visibility due to the inconspicuous color of graphene.

It is sectional drawing which shows the 1st aspect in embodiment of this invention. It is sectional drawing which shows the 2nd aspect in embodiment of this invention.

  The transparent conductive member 1 according to this embodiment includes a graphene layer 2, a colored layer 3, and a base material 4. In the transparent conductive member 1, the graphene layer 2 and the colored layer 3 overlap each other. In addition, the substrate 4 supports the graphene layer 2 and the colored layer 3.

The transparent conductive member 1 has a first region 5 composed of a region where the graphene layer 2, the colored layer 3 and the substrate 4 overlap each other, and the colored layer 3 and the substrate 4 overlap each other and the graphene layer 2 includes A second region 6 made of a non-overlapping region is formed. The relationship shown in the following formula (1) is the difference in L ^* ΔL ^* , difference in a ^* Δa ^* , and difference in b ^* Δb ^* between the transmitted color in the first region and the transmitted color in the second region. Meet. Note that L ^* , a ^* , and b ^* are coordinates in the CIE 1976 (L ^* , a ^* , b ^* ) color space.
{(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 ≦ 1.2 (1)
The transparent conductive member 1 obtained according to the present embodiment has both high transparency and high conductivity, and is expected to be applied to various uses such as transparent electrodes, touch panel components, display components, and the like.

  Furthermore, when the graphene layer 2 and the colored layer 3 are overlapped and the color difference between the first region 5 and the second region 6 is small as described above, the color of the graphene layer 2 becomes inconspicuous in the transparent conductive member 1. For this reason, deterioration of the appearance such as the patterned graphene layer 2 appearing as spots is suppressed. For this reason, the external appearance of the apparatus provided with the transparent conductive member 1 becomes good. In particular, when the transparent conductive member 1 is applied to an apparatus that displays an image such as a touch panel component or a display component, the visibility of the image is improved. Will improve.

  In FIG. 1, the 1st aspect of the transparent conductive member 1 by this embodiment is shown. In this embodiment, the substrate 4, the graphene layer 2, and the colored layer 3 have a structure that overlaps in this order. That is, the graphene layer 2 having a patterned shape is laminated on the substrate 4. Further, a colored layer 3 is laminated on the substrate 4 so as to cover the graphene layer 2. The colored layer 3 covers the graphene layer 2 and is further filled in the gaps of the graphene layer 2 on the substrate 4. Since the colored layer 3 covers the graphene layer 2 in this way, the graphene layer 2 is protected by the colored layer 3. As a result, the transparent conductive member 1 has the first region 5 formed of a region in which the base material 4, the graphene layer 2, and the colored layer 3 overlap in this order, and the colored layer 3 and the base material 4 are overlapped. The graphene layer 2 is formed with a second region 6 made of a non-overlapping region.

  Although it does not restrict | limit especially as a material of the base material 4, For example, transparent glass, such as soda-lime glass and an alkali free glass; Polyester resin, polyolefin resin, polyamide resin, epoxy resin, fluorine resin, cellulose resin, polycarbonate resin, acrylic resin For example, a transparent plastic composed of the like. The shape of the substrate 4 may be a film shape or a plate shape.

  When the substrate 4 is formed from a polyester film, as the polyester, for example, an aromatic dicarboxylic acid component such as terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4′-diphenyldicarboxylic acid, Aromatic polyesters produced by reaction with glycol components such as ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, etc. are preferred, especially polyethylene terephthalate, polyethylene-2 1,6-naphthalene dicarboxylate is preferred. Further, the polyester may be a copolyester such as the plurality of components exemplified above.

  The base material 4 may contain organic or inorganic particles. In this case, the winding property and transportability of the base material 4 are improved. Examples of such particles include calcium carbonate particles, calcium oxide particles, aluminum oxide particles, kaolin, silicon oxide particles, zinc oxide particles, crosslinked acrylic resin particles, crosslinked polystyrene resin particles, urea resin particles, melamine resin particles, and crosslinked silicone resin particles. Etc. The substrate 4 may also contain a colorant, an antistatic agent, an ultraviolet absorber, an antioxidant, a lubricant, a catalyst, other resins, and the like as long as the transparency is not impaired.

  The haze of the substrate 4 is preferably 3% or less. In this case, the visibility of an image through the transparent conductive member 1 is improved, and the haze of the substrate 4 is particularly suitable as a film for optical use. More preferably, the haze is 1.5% or less. Further, the base material may be colorless or colored.

  Although the thickness in particular of the base material 4 is not restrict | limited, When the base material 4 is a film form, it is preferable that the thickness is the range of 25 micrometers or more and 200 micrometers or less. In particular, when the thickness of the substrate 4 is 25 μm or more and 100 μm or less, the transparent conductive member 1 can be made thinner and lighter, and the occurrence of interference on the front and back of the transparent conductive member 1 is suppressed. Thermal contraction when the is heated is suppressed, and defects such as deterioration of workability due to thermal contraction of the base material 4 are suppressed.

  The substrate 4 may have a multilayer structure. For example, the substrate 4 may include a plate-like or sheet-like base portion made of transparent glass or plastic as described above, and one or more resin layers laminated on the base portion.

  The resin layer is preferably formed from a reactive curable resin composition. For example, the resin layer is preferably formed from at least one of a thermosetting resin composition and an active energy ray curable resin composition.

  The thermosetting resin composition includes, for example, thermosetting resins such as phenol resin, urea resin, diallyl phthalate resin, melamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, silicon resin, polysiloxane resin, and the like. contains. A crosslinking agent, a polymerization initiator, a curing agent, a curing accelerator, a solvent and the like may be used together with the thermosetting resin as necessary. A resin layer can be formed by applying such a thermosetting resin composition and subsequently heating and thermosetting the thermosetting resin composition.

  The active energy ray-curable resin composition preferably includes a resin having an acrylate functional group. Examples of the resin having an acrylate functional group include oligomers such as (meth) acrylates of a relatively low molecular weight polyfunctional compound, prepolymers, and the like. Examples of the polyfunctional compound include polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols. The active energy ray-curable resin composition preferably further contains a reactive diluent. Examples of reactive diluents include monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone, trimethylolpropane tri (meth) acrylate, and hexanediol (meth) acrylate. , Tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di The polyfunctional monomer of (meth) acrylate is mentioned.

  When the active energy ray curable resin composition is a photocurable resin composition such as an ultraviolet curable resin composition, the photocurable resin composition preferably contains a photopolymerization initiator. Examples of the photopolymerization initiator include acetophenones, benzophenones, α-amyloxime esters, thioxanthones, and the like. The photocurable resin composition may contain a photosensitizer in addition to the photopolymerization initiator or in place of the photopolymerization initiator. Examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone. A resin layer can be formed by applying such a photocurable resin composition and subsequently irradiating the photocurable resin composition with light such as ultraviolet rays and photocuring.

  The refractive index of the resin layer can be easily adjusted by the composition of the resin composition for forming the resin layer. Moreover, it is also preferable that the refractive index of a resin layer is adjusted by the resin layer containing the particle for refractive index adjustment, and the ratio being adjusted.

  The particle diameter of the particles for adjusting the refractive index is preferably sufficiently small, that is, the particles for adjusting the refractive index are preferably so-called ultrafine particles. In this case, the light transmittance of the resin layer is sufficiently maintained. The particle diameter of the particles for adjusting the refractive index is particularly preferably in the range of 0.5 nm to 200 nm. The particle diameter of the particles for adjusting the refractive index is the diameter of a circle (area equivalent circle) having the same area as the projected area calculated from the electron micrograph image of the particles.

  The refractive index adjusting particles are preferably particles having a relatively high refractive index, and particularly preferably particles having a refractive index of 1.6 or more. These particles are preferably metal or metal oxide particles.

  The content of the refractive index adjusting particles in the resin layer is appropriately adjusted so that the refractive index of the resin layer has an appropriate value. In particular, it is preferable to adjust so that the ratio of the refractive index adjusting particles in the resin layer is 5 to 70% by volume.

Specific examples of the particles for adjusting the refractive index include particles containing one or more oxides selected from titanium, aluminum, cerium, yttrium, zirconium, niobium, and antimony. Specific examples of the oxide include ZnO (refractive index 1.90), TiO ₂ (refractive index 2.3 to 2.7), CeO ₂ (refractive index 1.95), Sb ₂ O ₅ (refractive index 1. 71), SnO _2, ITO (refractive index 1.95), Y ₂ O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.95), ZrO ₂ (refractive index 2.05), Al ₂ O ₃ (refractive index 1.63) and the like.

It is also preferable that the resin layer has antistatic performance. In this case, charging of the transparent conductive member 1 is suppressed, and adhesion of dust to the transparent conductive member 1 is suppressed. For this purpose, the resin layer preferably contains conductive particles. The conductive particles may simultaneously function as refractive index adjusting particles. The conductive particles are preferably nanoparticles, and particularly preferably ultrafine particles having a particle size of 0.5 to 200 nm. The particle diameter of the conductive particles is also the diameter of an area equivalent circle. Examples of the material of the conductive particles include appropriate metals and metal oxides having conductivity, and specifically include oxides of one or more metals selected from indium, zinc, tin, and antimony. More specifically, indium oxide (ITO), tin oxide (SnO ₂ ), antimony / tin oxide (ATO), lead / titanium oxide (PTO), antimony oxide (Sb ₂ O ₅ ) and the like can be mentioned. .

In order to impart sufficient antistatic performance to the resin layer, it is preferable that the sheet resistance of the resin layer is 10 ¹⁵ Ω / □ or less by containing conductive particles. The lower the sheet resistance of the resin layer, the better the antistatic property. Therefore, the lower limit is not particularly set. However, since there is a limit to reducing the sheet resistance, the practical lower limit of the sheet resistance of the resin layer is 10 ⁶ Ω. / □.

  The content of the conductive particles in the resin layer is adjusted as appropriate so that the antistatic performance of the resin layer is an appropriate level, but the ratio of the conductive particles in the resin layer is particularly 5 to 70% by mass. It is preferable to adjust so.

  A resin layer may be formed from the composition containing the binder material as shown below, and the particle | grains for refractive index adjustment used as needed. When the binder material and the particles for adjusting the refractive index are used in combination, the refractive index of the resin layer is appropriately adjusted depending on the combination, the mixing ratio, and the like. This resin layer can be formed by curing the composition by subjecting the composition to treatment such as heating, humidification, ultraviolet irradiation, and electron beam irradiation according to the properties of the binder material.

  As the binder material, a polymer having a main chain of at least one of silicon alkoxide resin, saturated hydrocarbon and polyether (for example, UV curable resin composition, thermosetting resin composition, etc.), fluorine atom in the polymer chain And a resin containing a unit containing.

As a silicon alkoxide-based resin, a silicon alkoxide represented by R _m Si (OR ′) _n (R and R ′ are alkyl groups having 1 to 10 carbon atoms, m + n = 4, m and n are integers). Examples include oligomers and polymers that are hydrolyzed condensates. Specific examples of the silicon alkoxide include tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxy. Silane, tetrapentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxy Silane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, di Chill propoxysilane, dimethyl-butoxy silane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane, and the like.

  As the binder material, a reactive organosilicon compound having a plurality of groups (polymerizable double bond group or the like) that undergoes reactive crosslinking by heat or active energy rays may be used. The molecular weight of the organosilicon compound is preferably 5000 or less. Such reactive organosilicon compounds are obtained by reacting one terminal vinyl functional polysilane, both terminal vinyl functional polysilane, one terminal vinyl functional polysiloxane, both terminal vinyl functional polysiloxane, and these compounds. Examples include vinyl functional polysilanes and vinyl functional polysiloxanes. In addition to these, examples of the reactive organic silicon compound include (meth) acryloxysilane compounds such as 3- (meth) acryloxypropyltrimethoxysilane and 3- (meth) acryloxypropylmethyldimethoxysilane.

  As the particles for adjusting the refractive index, it is preferable to use particles having a relatively low refractive index. Examples of the material for adjusting the refractive index include silica, magnesium fluoride, lithium fluoride, aluminum fluoride, calcium fluoride, sodium fluoride, and the like. It is preferable that the refractive index adjusting particles include hollow particles. A hollow particle is a particle having a cavity surrounded by an outer shell. The refractive index of the hollow particles is preferably 1.20 to 1.45.

  The particles for adjusting the refractive index are preferably subjected to a surface treatment for improving the wettability with the binder material, if necessary.

  The particle diameter of the refractive index adjusting particles is preferably sufficiently small, that is, the refractive index adjusting particles are preferably so-called ultrafine particles. In this case, the light transmittance of the resin layer is sufficiently maintained. . The particle diameter of the particles for adjusting the refractive index is particularly preferably in the range of 0.5 nm to 200 nm. The particle diameter of the particles for adjusting the refractive index is the diameter of a circle (area equivalent circle) having the same area as the projected area calculated from the electron micrograph image of the particles.

  The content of the refractive index adjusting particles in the resin layer is adjusted as appropriate so that the refractive index value of the resin layer becomes an appropriate value, but in particular the ratio of the refractive index adjusting particles in the resin layer is It is preferable to adjust so that it may become 20-99 volume%.

  The composition may further contain a water and oil repellent material. As the water and oil repellent material, a general wax-based material or the like can be used.

  The graphene layer 2 is composed of a graphene sheet. The graphene layer 2 may be composed of a single-layer graphene sheet, but may be composed of a plurality of layers of graphene sheets. The graphene layer 2 is preferably composed of a graphene sheet of 1 to 300 layers, particularly preferably a graphene sheet of 1 to 15 layers.

  The graphene layer 2 is patterned. The shape, dimensions, and the like of the graphene layer 2 are set as appropriate. For example, the graphene layer 2 forms a sensing electrode composed of a plurality of pad-shaped electrodes, fine wires connecting the pad-shaped electrodes, and a lead-out line connected to the sensing electrodes. In this case, the pad-like electrode is formed to have a size of 0.5 to 2.5 mm square in plan view, for example. Further, the thin line and the lead line are formed in a range of, for example, a line width of 10 to 100 μm.

  The graphene layer 2 is formed on the substrate 4 by an appropriate method. For example, a step of preparing a metal foil, a step of forming the graphene layer 2 on the metal foil by a vapor deposition method, a step of bonding the surface of the graphene layer 2 opposite to the metal foil to the substrate 4, and a metal foil The patterned graphene layer 2 is formed on the substrate 4 by a method including the step of removing and the step of patterning the graphene layer 2.

  The metal foil is preferably composed of a metal that functions as a catalyst for forming graphene. Such metals include nickel, copper, aluminum, iron, cobalt, tungsten, and the like.

  The graphene layer 2 is formed on this metal foil. The graphene layer 2 is composed of a graphene sheet. The graphene sheet is formed by an evaporation method such as a thermal CVD method or a plasma CVD method. In this case, for example, a metal foil is arranged in the chamber, a carbon source in a gas phase is supplied into the chamber, and the carbon source is heated or plasma-treated in the chamber. As a result, the carbon source is decomposed and the carbon atoms are bonded to each other to form a hexagonal planar structure, whereby a graphene sheet is formed on the metal foil.

  The carbon source for forming the graphene sheet is not particularly limited, but carbon monoxide, methane, ethane, ethylene, ethanol, acetylene, propane, propylene, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, Examples include benzene and toluene.

When the graphene layer 2 is formed by the thermal CVD method, the temperature in the chamber, the pressure of the carbon source in the chamber, and the like are appropriately adjusted. The temperature in the chamber is adjusted to a range of 300 to 2000 ° C., for example. The pressure of the carbon source in the chamber is adjusted, for example, in the range of 1.3 × 10 ^{−4 to} 1.4 × 10 ⁴ Pa, preferably in the range of 1.3 × 10 ^{−1 to} 1.0 × 10 ⁵ Pa. It is adjusted with.

  In the case where the graphene layer 2 is formed by the thermal CVD method, it is also preferable that hydrogen is supplied into the chamber together with the carbon source. The amount of hydrogen in this case is preferably 5% by volume or more and 40% by volume or less, more preferably 10% by volume or more and 30% by volume or less, and more preferably 15% by volume or more and 25% by volume or less. It is particularly preferable if it is present.

  In joining the surface of the graphene layer 2 opposite to the metal foil to the transparent base material 4, an appropriate method can be adopted. For example, when it consists of the material which melts by heating at least the surface layer of the base material 4, the graphene layer 2 and the base material 4 can be heat-seal | fused. When the substrate 4 has a multilayer structure, the graphene layer 2 is overlaid on the resin layer while the resin layer disposed in the outermost layer of the substrate 4 is in an uncured state or a semi-cured state. The resin layer may be cured in a state, and thereby the surface of the graphene layer 2 opposite to the metal foil may be bonded to the transparent substrate 4. In this case, the resin layer in an uncured state or a semi-cured state is cured by being subjected to a treatment such as heating, humidification, ultraviolet irradiation, or electron beam irradiation according to the composition of the composition constituting the resin layer. Is done.

  After the graphene layer 2 and the substrate 4 are bonded in this way, the metal foil is removed from the graphene layer 2. Although it does not restrict | limit especially as a removal method of metal foil, For example, metal foil can be removed by performing wet etching process to the whole metal foil.

  The graphene layer 2 may be bonded to the substrate 4 by a transfer method. In this case, for example, the graphene layer 2 is first formed on the metal foil by vapor deposition or the like as described above. The graphene layer 2 is overlaid with a transfer plastic film (transfer film), and then all the metal foil is removed by etching or the like. Thereby, the member for transfer provided with the film for transfer and the graphene layer 2 piled up on it is formed. The graphene layer 2 in this transfer member is superposed on and closely adhered to the substrate 4. Furthermore, after the transfer film is heated as necessary, the transfer film is peeled off from the graphene layer 2, whereby the graphene layer 2 is transferred onto the substrate 4.

The graphene layer 2 bonded on the substrate 4 is subjected to a patterning process. For the patterning process of the graphene layer 2, a known appropriate method is adopted. For example, the graphene layer 2 is partially removed by subjecting the graphene layer 2 to dry etching treatment such as partial electron beam irradiation, laser beam irradiation, or O ₂ plasma treatment. Layer 2 can be patterned.

  The patterning process on the graphene layer 2 may be performed before the graphene layer 2 is bonded to the substrate 4. That is, the patterning process may be performed on the graphene layer 2 on the metal foil, or the patterning process may be performed on the graphene layer 2 on the transfer film. Moreover, the graphene layer 2 having a shape patterned when the graphene layer 2 is formed on the metal foil may be formed.

The colored layer 3 is a colored transparent layer. The color of the colored layer 3 is such that the L ^* difference ΔL ^* , the a ^* difference Δa ^* , and the b ^* difference Δb ^* between the transmission color of the first region 5 and the transmission color of the second region 6 are: {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 is adjusted so as to satisfy the relationship 1.2 ≦ 1.2.

  In particular, when the substrate 2 is colorless, the color of the colored layer 3 is preferably adjusted to the same color tone as the graphene layer 2. Moreover, when the base material 2 is colored, in order to correct the color of the base material 2, the color of the colored layer 3 is adjusted so that the color of the colored layer 3 and the color of the base material 2 have a complementary color relationship. It is preferable.

  The colored layer 3 preferably contains a colorant, that is, the resin composition for forming the colored layer 3 preferably contains a colorant. In this case, the colored layer 3 is colored in a desired color by the coloring material.

  Examples of the colorant include carbon black, synthetic dye, iron oxide, black titanium compound, and other metal oxides. The colored layer 3 may contain only one type of colorant or may contain multiple types of colorants. The kind of the colorant contained in the color layer 3 and the ratio of the colorant in the color layer 3 are appropriately selected according to the color, transparency, and the like required for the color layer 3. When the substrate 2 is colorless, only a black coloring material such as carbon black may be used. When the substrate 2 is colored, a colorant for color tone correction (for example, a red colorant, a blue colorant, etc.) that is complementary to the color of the substrate 2 together with a black colorant such as carbon black Etc.) are preferably used. As a colorant for color tone correction, a general colorant such as an inorganic pigment, an organic pigment, an organic dye, or a pigment can be appropriately used. Examples of inorganic pigments include cobalt compounds, iron compounds, and chromium compounds. Examples of organic pigments include azo, indolinone, quinacridone, vat, phthalocyanine, and naphthalocyanine pigments. Organic dyes and pigments include azo, azine, anthraquinone, indigoid, oxazine, quinophthalone, squalium, stilbene, triphenylmethane, naphthoquinone, pyrarozone, and polymethine colorants. Can be mentioned. Of these, organic dyes are preferably used from the viewpoint of color developability. The resin composition for forming the colored layer 3 contains a colorant according to the type, ratio, and the like of the colorant required for the colored layer 3.

  A resin composition for forming the colored layer 3 is applied on the surface of the substrate 4 on which the graphene layer 2 is formed, and then the resin composition is cured to form the colored layer 3. Is done. The thickness of the colored layer 3 is set as appropriate. In order to sufficiently increase the hardness of the colored layer 3 and to sufficiently improve the wear resistance of the colored layer 3, the thickness of the colored layer 3 is from 0.05 to 0.05. A range of 10 μm is preferable. The thickness of the colored layer 3 is a dimension between the surface of the substrate 4 and the surface of the colored layer 3.

  The colored layer 3 is preferably formed from a reactive curable resin composition containing a colorant. For example, the colored layer 3 may be formed from at least one of a thermosetting resin composition and an active energy ray curable resin composition. preferable.

  The thermosetting resin composition includes, for example, thermosetting resins such as phenol resin, urea resin, diallyl phthalate resin, melamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, silicon resin, polysiloxane resin, and the like. contains. A crosslinking agent, a polymerization initiator, a curing agent, a curing accelerator, a solvent and the like may be used together with the thermosetting resin as necessary. The colored layer 3 can be formed by applying such a thermosetting resin composition and subsequently heating and thermosetting the thermosetting resin composition.

  The active energy ray-curable resin composition preferably includes a resin having an acrylate functional group. Examples of the resin having an acrylate functional group include oligomers such as (meth) acrylates of a relatively low molecular weight polyfunctional compound, prepolymers, and the like. Examples of the polyfunctional compound include polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols. The active energy ray-curable resin composition preferably further contains a reactive diluent. Examples of reactive diluents include monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone, trimethylolpropane tri (meth) acrylate, and hexanediol (meth) acrylate. , Tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di The polyfunctional monomer of (meth) acrylate is mentioned.

  When the active energy ray curable resin composition is a photocurable resin composition such as an ultraviolet curable resin composition, the photocurable resin composition preferably contains a photopolymerization initiator. Examples of the photopolymerization initiator include acetophenones, benzophenones, α-amyloxime esters, thioxanthones, and the like. The photocurable resin composition may contain a photosensitizer in addition to the photopolymerization initiator or in place of the photopolymerization initiator. Examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone. Such a photocurable resin composition is applied, and subsequently the photocurable resin composition is irradiated with light such as ultraviolet rays to be photocured, whereby the colored layer 3 can be formed.

  The refractive index of the colored layer 3 can be easily adjusted by the composition of the resin composition for forming the colored layer 3. Moreover, it is also preferable that the refractive index of the colored layer 3 is adjusted by the colored layer 3 containing particles for adjusting the refractive index and the ratio thereof being adjusted.

  The particle diameter of the refractive index adjusting particles is preferably sufficiently small, that is, the refractive index adjusting particles are preferably so-called ultrafine particles. In this case, the light transmittance of the colored layer 3 is sufficiently maintained. . The particle diameter of the particles for adjusting the refractive index is particularly preferably in the range of 0.5 nm to 200 nm. The particle diameter of the particles for adjusting the refractive index is the diameter of a circle (area equivalent circle) having the same area as the projected area calculated from the electron micrograph image of the particles.

  The refractive index adjusting particles are preferably particles having a relatively high refractive index, and particularly preferably particles having a refractive index of 1.6 or more. These particles are preferably metal or metal oxide particles.

  The content of the refractive index adjusting particles in the colored layer 3 is appropriately adjusted so that the refractive index of the colored layer 3 has an appropriate value. In particular, it is preferable to adjust the ratio of particles for adjusting the refractive index in the colored layer 3 to 5 to 70% by volume.

Specific examples of the particles for adjusting the refractive index include particles containing one or more oxides selected from titanium, aluminum, cerium, yttrium, zirconium, niobium, and antimony. Specific examples of the oxide include ZnO (refractive index 1.90), TiO ₂ (refractive index 2.3 to 2.7), CeO ₂ (refractive index 1.95), Sb ₂ O ₅ (refractive index 1. 71), SnO _2, ITO (refractive index 1.95), Y ₂ O ₃ (refractive index 1.87), La ₂ O ₃ (refractive index 1.95), ZrO ₂ (refractive index 2.05), Al ₂ O ₃ (refractive index 1.63) and the like.

It is also preferred that the colored layer 3 has antistatic performance. In this case, charging of the transparent conductive member 1 is suppressed, and adhesion of dust to the transparent conductive member 1 is suppressed. For that purpose, it is preferable that the colored layer 3 contains conductive particles. The conductive particles may simultaneously function as refractive index adjusting particles. The conductive particles are preferably nanoparticles, and particularly preferably ultrafine particles having a particle size of 0.5 to 200 nm. The particle diameter of the conductive particles is also the diameter of an area equivalent circle. Examples of the material of the conductive particles include appropriate metals and metal oxides having conductivity, and specifically include oxides of one or more metals selected from indium, zinc, tin, and antimony. More specifically, indium oxide (ITO), tin oxide (SnO ₂ ), antimony / tin oxide (ATO), lead / titanium oxide (PTO), antimony oxide (Sb ₂ O ₅ ) and the like can be mentioned. .

In order to impart sufficient antistatic performance to the colored layer 3, it is preferable that the sheet resistance of the colored layer 3 is 10 ¹⁵ Ω / □ or less by containing conductive particles. The lower the sheet resistance of the colored layer 3 is, the more the antistatic property is improved. Therefore, the lower limit is not particularly set. However, since there is a limit to reducing the sheet resistance, the practical lower limit of the sheet resistance of the colored layer 3 is 10 ⁶ Ω / □.

  The content of the conductive particles in the colored layer 3 is adjusted as appropriate so that the antistatic performance of the colored layer 3 is at an appropriate level. In particular, the ratio of the conductive particles in the colored layer 3 is 5 to 70 mass. % Is preferably adjusted to be%.

  The colored layer 3 may be formed from a resin composition containing a coloring material and a binder material as shown below, and particles for adjusting the refractive index used as necessary. When the binder material and the particles for adjusting the refractive index are used in combination, the refractive index of the colored layer 3 is appropriately adjusted depending on the combination of the both, the blending ratio, and the like. The colored layer 3 can be formed by curing the resin composition by subjecting the resin composition to treatment such as heating, humidification, ultraviolet irradiation, and electron beam irradiation according to the properties of the binder material.

  As the binder material, a polymer having a main chain of at least one of silicon alkoxide resin, saturated hydrocarbon and polyether (for example, UV curable resin composition, thermosetting resin composition, etc.), fluorine atom in the polymer chain And a resin containing a unit containing.

As a silicon alkoxide-based resin, a silicon alkoxide represented by R _m Si (OR ′) n (R and R ′ are alkyl groups having 1 to 10 carbon atoms, m + n = 4, m and n are integers). Examples include oligomers and polymers that are hydrolyzed condensates. Specific examples of the silicon alkoxide include tetramethoxysilane, tetraethoxysilane, tetra-iso-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert-butoxy. Silane, tetrapentaethoxysilane, tetrapenta-iso-propoxysilane, tetrapenta-n-propoxysilane, tetrapenta-n-butoxysilane, tetrapenta-sec-butoxysilane, tetrapenta-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxy Silane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, di Chill propoxysilane, dimethyl-butoxy silane, methyl dimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane, and the like.

  As the binder material, a reactive organosilicon compound having a plurality of groups (polymerizable double bond group or the like) that undergoes reactive crosslinking by heat or active energy rays may be used. The molecular weight of the organosilicon compound is preferably 5000 or less. Such reactive organosilicon compounds are obtained by reacting one terminal vinyl functional polysilane, both terminal vinyl functional polysilane, one terminal vinyl functional polysiloxane, both terminal vinyl functional polysiloxane, and these compounds. Examples include vinyl functional polysilanes and vinyl functional polysiloxanes. In addition to these, examples of the reactive organic silicon compound include (meth) acryloxysilane compounds such as 3- (meth) acryloxypropyltrimethoxysilane and 3- (meth) acryloxypropylmethyldimethoxysilane.

  As the particles for adjusting the refractive index, it is preferable to use particles having a relatively low refractive index. Examples of the material for adjusting the refractive index include silica, magnesium fluoride, lithium fluoride, aluminum fluoride, calcium fluoride, sodium fluoride, and the like. It is preferable that the refractive index adjusting particles include hollow particles. A hollow particle is a particle having a cavity surrounded by an outer shell. The refractive index of the hollow particles is preferably 1.20 to 1.45.

  The particles for adjusting the refractive index are preferably subjected to a surface treatment for improving the wettability with the binder material, if necessary.

  The particle diameter of the refractive index adjusting particles is preferably sufficiently small, that is, the refractive index adjusting particles are preferably so-called ultrafine particles. In this case, the light transmittance of the colored layer 3 is sufficiently maintained. Become. The particle diameter of the particles for adjusting the refractive index is particularly preferably in the range of 0.5 nm to 200 nm. The particle diameter of the particles for adjusting the refractive index is the diameter of a circle (area equivalent circle) having the same area as the projected area calculated from the electron micrograph image of the particles.

  The content of the refractive index adjusting particles in the colored layer 3 is adjusted as appropriate so that the refractive index value of the colored layer 3 becomes an appropriate value, but in particular, the refractive index adjusting particles in the colored layer 3. It is preferable to adjust so that the ratio may become 20-99 volume%.

  The resin composition may further contain a water and oil repellent material. As the water and oil repellent material, a general wax-based material or the like can be used.

  In FIG. 2, the 2nd aspect of the transparent conductive member 1 by this embodiment is shown. In this aspect, the base material 4, the colored layer 3, and the graphene layer 2 have a structure that overlaps in this order. That is, the colored layer 3 is laminated on the base material 4, and the graphene layer 2 having a patterned shape is laminated on the surface of the colored layer 3 opposite to the base material 4. As a result, the transparent conductive member 1 has the first region 5 formed of a region in which the base material 4, the colored layer 3, and the graphene layer 2 overlap in this order, and the colored layer 3 and the base material 4 are overlapped. The graphene layer 2 is formed with a second region 6 made of a non-overlapping region.

  As the base material 4, the thing of the structure similar to a 1st aspect may be used.

The colored layer 3 is a colored transparent layer. The color of the colored layer 3 is the difference ΔL ^* between L ^* between the transmitted color of the first region 5 and the transmitted color of the second region 6 in the transparent conductive substrate 1 as in the first embodiment ^. , A ^* difference Δa ^* and b ^* difference Δb ^* are adjusted so as to satisfy the relationship {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 ≦ 1.2 Is done. The configuration of the colored layer 3 is the same as in the first embodiment.

  The colored layer 3 is formed by applying a resin composition for forming the colored layer 3 on the substrate 4 and subsequently curing the resin composition. As the composition for forming the colored layer 3, the same composition as in the first embodiment can be used. The thickness of the colored layer 3 is set as appropriate. In order to sufficiently increase the hardness of the colored layer 3 and to sufficiently improve the wear resistance of the colored layer 3, the thickness of the colored layer 3 is from 0.05 to 0.05. A range of 10 μm is preferable.

  The graphene layer 2 is comprised from a graphene sheet similarly to the case of a 1st aspect. The graphene layer 2 may be composed of a single-layer graphene sheet, but may be composed of a plurality of layers of graphene sheets. The graphene layer 2 is preferably composed of a graphene sheet of 1 to 300 layers, particularly preferably a graphene sheet of 1 to 15 layers.

  The graphene layer 2 is patterned. The shape, dimensions, and the like of the graphene layer 2 are set as appropriate. For example, the graphene layer 2 forms a sensing electrode composed of a plurality of pad-shaped electrodes, fine wires connecting the pad-shaped electrodes, and a lead-out line connected to the sensing electrodes. In this case, the pad-like electrode is formed to have a size of 0.5 to 2.5 mm square in plan view, for example. Further, the thin line and the lead line are formed in a range of, for example, a line width of 10 to 100 μm.

  The graphene layer 2 is formed on the colored layer 3 by an appropriate method. For example, a step of preparing a metal foil, a step of forming the graphene layer 2 on the metal foil by a vapor deposition method, a step of bonding the surface of the graphene layer 2 opposite to the metal foil to the colored layer 3, and a metal foil The patterned graphene layer 2 is formed on the colored layer 3 by a method including a step of removing and a patterning process on the graphene layer 2.

  The metal foil is preferably composed of a metal that functions as a catalyst for forming graphene. Such metals include nickel, copper, aluminum, iron, cobalt, tungsten, and the like. The graphene layer 2 is formed on this metal foil by the same method as in the first embodiment.

  In joining the surface of the graphene layer 2 opposite to the metal foil to the colored layer 3, an appropriate method can be adopted. For example, when the colored layer 3 is made of a material that melts when heated, the graphene layer 2 and the colored layer 3 can be heat-sealed. In addition, while the colored layer 3 is in an uncured state or a semi-cured state, the graphene layer 2 is overlaid on the colored layer 3, and the colored layer 3 is cured in this state, thereby being opposite to the metal foil of the graphene layer 2 The side surface may be joined to the colored layer 3. In this case, the colored layer 3 in an uncured state or a semi-cured state is subjected to treatment such as heating, humidification, ultraviolet irradiation, and electron beam irradiation according to the composition of the composition constituting the colored layer 3. It is cured with.

  After the graphene layer 2 and the colored layer 3 are bonded in this way, the metal foil is removed from the graphene layer 2. Although it does not restrict | limit especially as a removal method of metal foil, For example, metal foil can be removed by performing wet etching process to the whole metal foil.

  The graphene layer 2 may be bonded to the colored layer 3 by a transfer method. In this case, for example, the graphene layer 2 is first formed on the metal foil by vapor deposition or the like as described above. The graphene layer 2 is overlaid with a transfer plastic film (transfer film), and then all the metal foil is removed by etching or the like. Thereby, the member for transfer provided with the film for transfer and the graphene layer 2 piled up on it is formed. The graphene layer 2 in this transfer member is overlaid and adhered onto the colored layer 3. Furthermore, after the transfer film is heated as necessary, the transfer film is peeled off from the graphene layer 2, whereby the graphene layer 2 is transferred onto the colored layer 3.

  Subsequently, the graphene layer 2 is subjected to a patterning process. In the patterning process of the graphene layer 2, a known appropriate technique is adopted as in the case of the first aspect. Moreover, the patterning process to the graphene layer 2 may be performed before the graphene layer 2 is bonded to the colored layer 3 as in the case of the first aspect.

[Example 1]
As a base material, a PET film (made by Toray Industries, trade name Lumirror U46, thickness 125 μm) which is almost colorless but slightly yellowish was prepared.

  Further, UV curable hard coat resin (DIC Corporation, product number 7150F, solid content 62.5% by mass) 6.0 parts by mass, methyl ethyl ketone 93.1 parts by mass, carbon black (Mitsubishi Chemical Corporation, average particle size) 13 nm) A resin composition for forming a colored layer was prepared by blending 0.9 part by mass.

Moreover, 12-micrometer-thick copper foil was prepared and the graphene layer was formed on this copper foil by the thermal CVD method. At this time, the copper foil was placed in the chamber, and acetylene gas was introduced into the chamber at a constant rate of 200 sccm (3.38 × 10 ⁻² Pa · m ³ / sec), while the copper foil was heated at 400 ° C. for 20 hours. The graphene was produced | generated on copper foil by heat-processing for minutes. Subsequently, the copper foil was naturally cooled to grow graphene in a uniformly arranged state. The cooling rate was 600 ° C./min. As a result, a graphene layer was formed on the copper foil.

  The graphene layer on the copper foil was placed on and closely adhered to a transfer film (a heat release film manufactured by Nitto Denko Corporation, product name Riva Alpha No. 3195), and then all the copper foil was removed by etching. Subsequently, the graphene layer was subjected to a dry etching process using oxygen plasma, thereby patterning the graphene layer into a plurality of pad shapes having a size of 1.4 mm × 1.4 mm in plan view.

  Subsequently, the graphene layer was overlaid on the substrate, and in this state, the transfer film was heated at 120 ° C. for 5 minutes, and then the transfer film was peeled off, whereby the graphene layer was transferred onto the substrate.

Subsequently, after applying a resin composition for forming a colored layer on the surface of the substrate on which the graphene layer is formed, and further drying the resin composition by heating at 80 ° C. for 2 minutes, Furthermore, this resin composition was cured by irradiating with ultraviolet rays under a condition of 500 mJ / cm ^{2 in} a nitrogen atmosphere, thereby forming a colored layer having a thickness of 0.2 μm. Thereby, a transparent conductive member was obtained.

[Example 2]
As a base material, a PET film (made by Toray Industries, trade name Lumirror U46, thickness 125 μm) which is almost colorless but slightly yellowish was prepared.

  Also, UV curable hard coat resin (DIC Corporation, product number 7150F, solid content 62.5% by mass) 50.8 parts by mass, methyl ethyl ketone 0.6 parts by mass, carbon black (Mitsubishi Chemical Corporation, average particle size) 13nm) A resin composition for forming a colored layer was prepared by blending 48.6 parts by mass.

The resin composition is applied onto a substrate, and further dried by heating the resin composition at 80 ° C. for 2 minutes, and then the resin composition is further irradiated with ultraviolet rays at 500 mJ / cm ^2. In this way, a colored layer having a thickness of 3 μm was formed.

Moreover, 12-micrometer-thick copper foil was prepared and the graphene layer was formed on this copper foil by the thermal CVD method. At this time, the copper foil was placed in the chamber, and acetylene gas was introduced into the chamber at a constant rate of 200 sccm (3.38 × 10 ⁻² Pa · m ³ / sec), while the copper foil was heated at 400 ° C. for 20 hours. The graphene was produced | generated on copper foil by heat-processing for minutes. Subsequently, the copper foil was naturally cooled to grow graphene in a uniformly arranged state. The cooling rate was 600 ° C./min. As a result, a graphene layer was formed on the copper foil.

  The graphene layer on the copper foil was placed on and closely adhered to a transfer film (a heat release film manufactured by Nitto Denko Corporation, product name Riva Alpha No. 3195), and then all the copper foil was removed by etching. Subsequently, the graphene layer was subjected to a dry etching process using oxygen plasma, thereby patterning the graphene layer into a plurality of pad shapes having a size of 1.4 mm × 1.4 mm in plan view.

  Subsequently, the graphene layer was overlaid on the colored layer, and in this state, the transfer film was heated at 120 ° C. for 5 minutes, and then the transfer film was peeled off, whereby the graphene layer was transferred onto the colored layer. Thereby, a transparent conductive member was obtained.

[Example 3]
UV curable hard coat resin (DIC Corporation, product number 7150F, solid content 62.5% by mass) 50.8 parts by mass, methyl ethyl ketone 0.6 parts by mass, carbon black (Mitsubishi Chemical Corporation, average particle size 13 nm) The resin composition for forming a colored layer was prepared by mix | blending 48.4 mass parts and blue dye (The Hodogaya Chemical Co., Ltd. make, brand name SPLON BLUE GNH) 0.02 mass part.

  A transparent conductive member was obtained by the same method and conditions as in Example 2 except that this resin composition was used to form a colored layer. In this embodiment, in order to correct the yellowish color of the base material, a blue dye having a complementary color relationship is used.

[Comparative Example 1]
A transparent conductive member was obtained by the same method and conditions as in Example 1 except that the colored layer was not formed.

[Evaluation test]
(Transparent color)
Each of the transmission colors of the first region and the second region of the transparent conductive member obtained in each example, and each of the regions corresponding to the first region and the second region of the transparent conductive member obtained in Comparative Example 1 Based on the result of the measurement, the color of the transmitted color is measured using the CIE 1976 (L ^* , a ^* , b ^* ) color space coordinates, a spectrophotometer (model number CM-3600d) manufactured by Konica Minolta Sensing Co., Ltd. a region and the difference in L ^* between the second region [Delta] L ^*, a ^* difference .DELTA.a ^*, and b ^* calculates a difference [Delta] b ^* of further based on ^{this, ΔE = {(ΔL *)} 2 + The value of (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 was calculated.

(Visibility of graphene layer)
The transparent conductive member obtained in each Example and Comparative Example was visually observed to determine whether or not the graphene layer was easily visible.

(Pencil hardness)
The pencil hardness of the colored layer in the transparent conductive member obtained in each Example and the pencil hardness of the substrate in the transparent conductive member obtained in Comparative Example 1 were evaluated by a pencil hardness test according to JIS K5600. The criterion for the pencil hardness was that the colored layer was not damaged when it was 8 times or more out of 10 tests.

(Abrasion resistance)
A steel wool of # 0000 was placed on the colored layer in the transparent conductive member obtained in each Example and on the base material in the transparent conductive member obtained in Comparative Example 1, and about 49 kPa (500 g) was put on this steel wool. The steel wool was reciprocated 10 times at a speed of 3000 mm / min on the colored layer or the substrate while applying a load of / cm ² ). Then, the colored layer in each Example and the base material in the comparative example 1 were observed visually. The results are shown in the table below.

DESCRIPTION OF SYMBOLS 1 Transparent conductive member 2 Graphene layer 3 Colored layer 4 Base material 5 1st area | region 6 2nd area | region

Claims (3)

Comprising a graphene layer, a colored layer overlapping the graphene layer, and a transparent base material supporting the graphene layer and the colored layer,
A first region composed of a region where the graphene layer, the colored layer and the substrate overlap, and a second region composed of a region where the colored layer and the substrate overlap and the graphene layer does not overlap And are formed,
L ^* difference ΔL ^* , a ^* difference Δa ^* , and b ^* difference Δb ^* between the transmission color of the first region and the transmission color of the second region are shown in the following formula (1). Transparent conductive member that satisfies the relationship.
{(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^1/2 ≦ 1.2 (1) The transparent conductive member according to claim 1, wherein the graphene layer is interposed between the base material and the colored layer. The transparent conductive member according to claim 1, wherein the colored layer is interposed between the graphene layer and the base material.

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