JP2012009219A - Conductive material and touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive material and a touch panel which are excellent in optical transparency, conductivity, flexibility and handleability, and have an improved curling balance.SOLUTION: A conductive material comprises: a substrate; an undercoat layer and a conductive layer at least containing conductive fibers formed in this order on one surface of the substrate; and a hard coat layer on the other surface of the substrate. The average thickness of the conductive layer is 0.01-1 μm, the average thickness of the undercoat layer is 0.1-15 μm, and the average thickness of the hard coat layer is 0.5-5 μm.

Description

  The present invention relates to a conductive material and a touch panel using the conductive material.

In recent years, a touch panel is mounted on a display device such as a liquid crystal panel or electronic paper as an input device.
For example, a film having a hard coat layer on one surface and ITO on the other surface is mainly used for a resistive touch panel (see Patent Document 1). Patent Document 2 proposes a configuration in which an ITO transparent conductive film formed by an atmospheric pressure plasma method and a hard coat layer are laminated on the opposite surface with a base material interposed therebetween. However, when a film is used as a substrate, the film forming temperature during ITO film formation cannot be increased, so that the transparent conductivity is low, the ITO transparent conductive film after patterning is brittle, and the handling property is low. is there.

  For this reason, instead of the ITO transparent conductive film, attempts have been made to use silver nanowires that can be formed at a low temperature and have good transparent conductivity as a transparent conductive material. For example, Patent Document 3 proposes a configuration having a conductive layer containing metal nanowires and a hard coat layer on the opposite surface across the substrate.

  However, the characteristics of the transparent conductive film described in Patent Document 3 are still insufficient, providing a conductive material that is excellent in all of light transmittance, conductivity, flexibility, and handling properties, and has improved curl balance. This is the current situation.

Japanese Patent No. 3688136 JP 2004-13692 A JP 2009-70660 A

  An object of the present invention is to solve the above problems and achieve the following object. That is, the present invention is excellent in light transmittance, conductivity, flexibility, and handling properties, and uses a conductive material with improved curl balance and the use of the conductive material, thereby reducing the number of parts, making it thin and lightweight. An object is to provide a touch panel.

  As a result of intensive studies by the present inventors to solve the above-mentioned problems, a base material and a conductive layer containing an undercoat layer and at least conductive fibers (metal nanowires) on one surface of the base material are arranged in this order. And having a hard coat layer on the other surface of the substrate, the conductive layer has an average thickness of 0.01 μm to 1 μm, the undercoat layer has an average thickness of 0.1 μm to 15 μm, and the hard It has been found that by setting the average thickness of the coating layer to 0.5 μm to 5 μm, it is possible to provide a conductive material having excellent light transmission, conductivity, and handling properties, and excellent flexibility and curl balance. did.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A substrate, an undercoat layer on one surface of the substrate, and a conductive layer containing at least conductive fibers in this order, and a hard coat layer on the other surface of the substrate Become
The conductive layer has an average thickness of 0.01 μm to 1 μm,
The undercoat layer has an average thickness of 0.1 μm to 15 μm,
The conductive material is characterized in that an average thickness of the hard coat layer is 0.5 μm to 5 μm.
<2> The conductive material according to <1>, wherein the conductive layer has an average thickness of 0.05 μm to 0.5 μm.
<3> Any one of <1> to <2>, wherein the average thickness A of the conductive layer and the average thickness B of the hard coat layer satisfy the following formula: [(A / B) × 100] ≦ 30% The conductive material described.
<4> The average thickness C of the undercoat layer and the average thickness B of the hard coat layer satisfy any of the following formulas: <1> to <3> satisfying 60% ≦ [(C / B) × 100] The conductive material described.
<5> The conductive material according to <4>, wherein the following formula, 60% ≦ [(C / B) × 100] ≦ 150% is satisfied.
<6> The conductive material according to any one of <1> to <5>, wherein a mass ratio of components other than the conductive fiber in the conductive layer to the conductive fiber is 0.1 to 5.
<7> The conductive material according to any one of <1> to <6>, wherein the conductive fiber is a metal nanowire.
<8> The conductive material according to <7>, wherein the metal nanowire is any one of silver and an alloy of silver and a metal other than silver.
<9> The conductive material according to any one of <7> to <8>, wherein the metal nanowire has an average minor axis length of 100 nm or less and an average major axis length of 2 μm or more.
<10> The conductive material according to any one of <1> to <9>, wherein the total visible light transmittance in the conductive layer is 85% or more.
<11> The conductive material according to any one of <1> to <10>, wherein the surface resistance of the conductive layer is 0.1Ω / □ to 5,000Ω / □.
<12> A pattern forming method, wherein the conductive layer in the conductive material according to any one of <1> to <11> is exposed and developed.
<13> A touch panel using the conductive material according to any one of <1> to <11>.
<14> A display device with a touch panel function, comprising the touch panel according to <13>.

  According to the present invention, conventional problems can be solved, and a conductive material having excellent light transmittance, conductivity, flexibility, and handling property, and improved curl balance, and a component using the conductive material. A thin, lightweight touch panel can be provided with fewer points.

FIG. 1 is a schematic view showing an example of the conductive material of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a touch panel. FIG. 3 is a schematic explanatory diagram illustrating another example of the touch panel. FIG. 4 is a schematic plan view showing an example of arrangement of conductors in the touch panel shown in FIG. FIG. 5 is a schematic cross-sectional view showing still another example of the touch panel. FIG. 6 is a schematic view showing an example of the display device with a touch panel function of the present invention.

(Conductive material)
The conductive material of the present invention has a base material, an undercoat layer and a conductive layer in this order on one surface of the base material, and a hard coat layer on the other surface of the base material. The conductive material of the present invention may further have other layers such as a photosensitive layer, an antifouling layer, a UV cut layer, and an antireflection layer.

As long as the conductive material has the above configuration, the shape, structure, size and the like are not particularly limited, and can be appropriately selected according to the purpose. For example, the shape may be a film or sheet Examples of the structure include a single-layer structure and a laminated structure, and the size can be appropriately selected depending on the application.
The conductive material has flexibility and is preferably transparent, and the transparent includes colorless and transparent, colored transparent, translucent, colored translucent and the like.

  Here, FIG. 1 is a schematic view showing an example of the conductive material of the present invention. The conductive material 5 of FIG. 1 has a base material 1, an undercoat layer 2 and a conductive layer 3 in this order on one surface of the base material, and a hard coat layer 4 on the other surface of the base material 1. Have. In addition, although illustration is abbreviate | omitted, it is preferable that the conductive layer 3 in the said electrically-conductive material is patterned. Examples of the patterning include patterning performed with an existing ITO transparent conductive film, and examples include a rectangular pattern and a diamond pattern.

  In the present invention, the conductive layer has an average thickness of 0.01 μm to 1 μm, preferably 0.05 μm to 0.5 μm. If the average thickness is less than 0.01 μm, the in-plane distribution of conductivity may be non-uniform, and if it exceeds 1 μm, the transmittance may be lowered and transparency may be impaired.

  The average thickness of the undercoat layer is 0.1 μm to 15 μm, preferably 0.5 μm to 5 μm. When the average thickness of the undercoat layer is less than 0.1 μm, the effect of curl balance may not be exhibited. When the average thickness exceeds 15 μm, the undercoat layer may be curled on the contrary.

The average thickness of the hard coat layer is 0.5 μm to 5 μm, and preferably 1.0 μm to 4.0 μm. If the average thickness of the hard coat layer is less than 0.5 μm, sufficient hard coat properties may not be exhibited, and if it exceeds 5 μm, cracks may occur in the hard coat layer.
Here, the average thickness of the undercoat layer, the average thickness of the conductive layer, and the average thickness of the hard coat layer are, for example, obtained by observing the cross section of the material by microtome cutting and then SEM observation or embedding with an epoxy resin. Then, it can be measured by TEM observation of a section prepared with a microtome. The average thickness of each of these layers is an average value measured at 10 points.

  It is preferable that the average thickness A of the conductive layer and the average thickness B of the hard coat layer satisfy the following formula: [(A / B) × 100] ≦ 30%. When [(A / B) × 100] exceeds 30%, the transparency may be impaired or the hard coat performance may not be sufficiently exhibited.

The average thickness C of the undercoat layer and the average thickness B of the hard coat layer preferably satisfy the following formula: 60% ≦ [(C / B) × 100], and the following formula, 60% ≦ [(C / B) × 100] ≦ 150% is more preferable.
When [(C / B) × 100] is less than 60%, the curl balance between the conductive layer surface side and the hard coat layer side may be poor.

<Base material>
There is no restriction | limiting in particular about the shape, structure, size, etc. of the said base material, According to the objective, it can select suitably, For example, a film | membrane form, a sheet form, etc. are mentioned as said shape. Examples of the structure include a single layer structure and a laminated structure. The size can be appropriately selected according to the application.

There is no restriction | limiting in particular as said base material, According to the objective, it can select suitably, For example, a transparent substrate, a synthetic resin sheet (film), a metal substrate, a ceramic board, a semiconductor substrate which has a photoelectric conversion element, etc. Is mentioned. If necessary, the substrate can be subjected to pretreatment such as chemical treatment such as a silane coupling agent, plasma treatment, ion plating, sputtering, gas phase reaction method, vacuum deposition and the like.
Examples of the transparent glass substrate include white plate glass, blue plate glass, and silica-coated blue plate glass.
Examples of the synthetic resin sheet include a polyethylene terephthalate (PET) sheet, a polycarbonate sheet, a polyethersulfone sheet, a polyester sheet, an acrylic resin sheet, a vinyl chloride resin sheet, an aromatic polyamide resin sheet, a polyamideimide sheet, and a polyimide sheet. Is mentioned.
Examples of the metal substrate include an aluminum plate, a copper plate, a nickel plate, and a stainless plate.

The total visible light transmittance of the substrate is preferably 70% or more, more preferably 85% or more, and still more preferably 90% or more. If the total visible light transmittance is less than 70%, the transmittance may be low and may cause a problem in practical use.
In the present invention, a substrate that is colored to the extent that the object of the present invention is not hindered can also be used.

There is no restriction | limiting in particular as thickness of the said base material, Although it can select suitably according to the objective, 1 micrometer-500 micrometers are preferable, 3 micrometers-400 micrometers are more preferable, and 5 micrometers-300 micrometers are still more preferable.
If the thickness is less than 1 μm, the yield may decrease due to difficulty in handling in the coating process, and if it exceeds 500 μm, the thickness and mass may be a problem in portable applications. is there.

<Undercoat layer>
The undercoat layer contains at least a polymer, and further contains other components as necessary.

-Polymer-
The polymer is not particularly limited and may be appropriately selected depending on the intended purpose.For example, it may be a natural polymer such as gelatin, gelatin derivative, casein, agar, starch, dextran, polyvinyl alcohol, polyacrylic resin, Examples thereof include synthetic polymers such as carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, (meth) acrylic acid copolymer, and a copolymer composed of styrene / butyl acrylate / glycidyl acrylate. These may be used individually by 1 type and may use 2 or more types together.

  The other components are not particularly limited and may be appropriately selected depending on the intended purpose. For example, fillers, surfactants, antioxidants, sulfurization inhibitors, metal corrosion inhibitors, viscosity modifiers, preservatives And various other additives.

The undercoat layer can be formed by applying an undercoat layer-use cloth liquid containing the polymer and, if necessary, the other components onto a substrate and drying it.
The coating method is not particularly limited and may be appropriately selected depending on the purpose. For example, a roll coating method, a bar coating method, a dip coating method, a spin coating method, a casting method, a die coating method, a blade coating method, a bar coating method, and the like. Examples thereof include a coating method, a gravure coating method, a curtain coating method, a spray coating method, and a doctor coating method.

<Hard coat layer>
There is no restriction | limiting in particular about the shape, structure, size, etc. of the said hard-coat layer, According to the objective, it can select suitably, For example, a film | membrane form, a sheet form, etc. are mentioned as said shape. Examples of the structure include a single layer structure and a laminated structure. The size can be appropriately selected according to the application.

  The hard coat layer contains an ionizing radiation-curable polyfunctional compound and particles, and further contains other components as necessary.

-Ionizing radiation curable polyfunctional compound-
Examples of the ionizing radiation curable polyfunctional compound include ionizing radiation curable polyfunctional monomers and ionizing radiation curable polyfunctional oligomers.
Examples of the functional group of the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer include a photopolymerizable functional group, an electron beam polymerizable functional group, and a radiation polymerizable functional group. Among these, a photopolymerizable functional group is particularly preferable.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among these, a (meth) acryloyl group is particularly preferable.
As the ionizing radiation-curable polyfunctional compound, monomers described in paragraphs [0087] and [0088] of JP-A-2006-30740 can be used. Moreover, the hardening method as described in Paragraph [0089] of Unexamined-Japanese-Patent No. 2006-30740 can be used. In the case of photopolymerization, for example, the photopolymerization initiators described in paragraphs [0090] to [0093] of JP-A-2006-30740 can be used.

-Particles-
The particles are not particularly limited and may be appropriately selected according to the purpose. For example, particles of inorganic compounds such as silica particles and TiO ₂ particles; acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine Examples thereof include resin particles such as resin particles and benzoguanamine resin particles. Among these, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are particularly preferable.
The average particle size of the particles is preferably 1.0 μm to 10.0 μm, more preferably 1.5 μm to 7.0 μm.

  For the purpose of controlling the refractive index, if necessary, the hard coat layer contains a high refractive index monomer, inorganic fine particles having a size that does not cause light scattering (primary particle diameter is 10 nm to 200 nm), or both. Can be added. In addition to the effect of controlling the refractive index, the inorganic fine particles also have an effect of suppressing curing shrinkage due to a crosslinking reaction. As the inorganic fine particles, for example, a compound described as an inorganic filler in paragraph [0120] of JP-A-2006-30740 can be used.

  The hard coat layer can be formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable polyfunctional compound. For example, a coating solution containing an ionizing radiation curable polyfunctional monomer or polyfunctional oligomer is applied onto a substrate, and the ionizing radiation curable polyfunctional monomer or polyfunctional oligomer is formed by a crosslinking reaction or a polymerization reaction. be able to.

<Conductive layer>
The conductive layer contains at least conductive fibers, and contains a binder, a photosensitive compound, and other components as necessary.

[Conductive fiber]
There is no restriction | limiting in particular as a structure of the said conductive fiber, Although it can select suitably according to the objective, It is preferable that it is either a solid structure or a hollow structure.
Here, the solid structure fiber may be referred to as a wire, and the hollow structure fiber may be referred to as a tube.
A conductive fiber having an average minor axis length of 5 nm to 1,000 nm and an average major axis length of 1 μm to 100 μm may be referred to as “nanowire”.
In addition, conductive fibers having an average minor axis length of 1 nm to 1,000 nm and an average major axis length of 0.1 μm to 1,000 μm and having a hollow structure may be referred to as “nanotubes”.
The material of the conductive fiber is not particularly limited as long as it has conductivity, and can be appropriately selected according to the purpose, but is preferably at least one of metal and carbon. Especially, it is preferable that the said conductive fiber is at least any one of a metal nanowire, a metal nanotube, and a carbon nanotube.

<< Metal nanowires >>
-Material-
There is no restriction | limiting in particular as a material of the said metal nanowire, According to the objective, it can select suitably, For example, the group which consists of a 4th period, a 5th period, and a 6th period of a long periodic table (IUPAC1991) At least one metal selected from the group 2, more preferably at least one metal selected from the group 2 to group 14, the group 2, the group 8, the group 9, the group 10, the group 11, At least one metal selected from Group 12, Group 13, and Group 14 is more preferable, and it is particularly preferable that it is included as a main component.

-Metal-
Examples of the metal include copper, silver, gold, platinum, palladium, nickel, tin, cobalt, rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantel, titanium, bismuth, antimony, and lead. Or alloys thereof. Among these, silver and an alloy with silver are preferable in terms of excellent conductivity.
Examples of the metal used in the alloy with silver include platinum, osmium, palladium, and iridium. These may be used alone or in combination of two or more.

-Shape-
There is no restriction | limiting in particular as a shape of the said metal nanowire, According to the objective, it can select suitably, For example, it can take arbitrary shapes, such as a column shape, a rectangular parallelepiped shape, and the column shape from which a cross section becomes a polygon. In applications where high transparency is required, a cylindrical shape or a cross-sectional shape with rounded polygonal corners is preferable.
The cross-sectional shape of the metal nanowire can be examined by applying a metal nanowire aqueous dispersion on a substrate and observing the cross-section with a transmission electron microscope (TEM).

−Average minor axis length diameter and average major axis length−
The average minor axis length of the metal nanowire (sometimes referred to as “average minor axis diameter” or “average diameter”) is preferably 1 nm to 50 nm, more preferably 10 nm to 40 nm, and even more preferably 15 nm to 35 nm. .
When the average minor axis length is less than 1 nm, the oxidation resistance may be deteriorated and the durability may be deteriorated. When the average minor axis length is more than 50 nm, scattering due to metal nanowires occurs and sufficient transparency is obtained. There are times when you can't.
The average minor axis length of the metal nanowires was observed using 300 transmission metal microscopes (TEM; JEM-2000FX, JEM-2000FX), and the average value of the metal nanowires was determined from the average value. The average minor axis length was determined. In addition, the shortest axis length when the short axis of the metal nanowire is not circular is the shortest axis.

The average major axis length (sometimes referred to as “average length”) of the metal nanowires is preferably 1 μm to 40 μm, more preferably 3 μm to 35 μm, and even more preferably 5 μm to 30 μm.
If the average major axis length is less than 1 μm, it may be difficult to form a dense network and sufficient conductivity may not be obtained. If it exceeds 40 μm, the metal nanowires are too long and manufactured. Sometimes entangled and agglomerates may occur during the manufacturing process.
The average major axis length of the metal nanowire is observed, for example, using a transmission electron microscope (TEM; JEM-2000FX, JEM-2000FX). The average major axis length was determined. In addition, when the said metal nanowire was bent, the circle | round | yen which makes it an arc was considered and the value calculated from the radius and curvature was made into the major axis length.

-Manufacturing method-
There is no restriction | limiting in particular as a manufacturing method of the said metal nanowire, Although it may manufacture by what kind of method, a metal ion is reduce | restored, heating in the solvent which melt | dissolved the halogen compound and the dispersion additive as follows. It is preferable to manufacture by.
Moreover, as a manufacturing method of metal nanowire, Unexamined-Japanese-Patent No. 2009-215594, Unexamined-Japanese-Patent No. 2009-242880, Unexamined-Japanese-Patent No. 2009-299162, Unexamined-Japanese-Patent No. 2010-84173, Unexamined-Japanese-Patent No. 2010-86714 Etc. can be used.

The solvent is preferably a hydrophilic solvent, and examples thereof include water, alcohols, ethers, and ketones. These may be used alone or in combination of two or more.
Examples of the alcohols include methanol, ethanol, propanol, isopropanol, butanol, and ethylene glycol.
Examples of the ethers include dioxane and tetrahydrofuran.
Examples of the ketones include acetone.

As heating temperature at the time of the said heating, 250 degrees C or less is preferable, 20 to 200 degreeC is more preferable, 30 to 180 degreeC is more preferable, 40 to 170 degreeC is still more preferable.
If the heating temperature is less than 20 ° C., the lower the heating temperature, the lower the nucleation probability, and the metal nanowires become too long, so the metal nanowires are likely to be entangled, and the dispersion stability may deteriorate. When it exceeds 250 ° C., the corner of the cross section of the metal nanowire becomes steep, and the transmittance in the evaluation of the coating film may be lowered.
If necessary, the temperature may be changed during the formation process of the metal nanowires, and the monodispersity by controlling the nucleation of metal nanowires, suppressing renucleation, and promoting selective growth by changing the temperature during the process. The improvement effect can be improved.

The heating is preferably performed by adding a reducing agent.
The reducing agent is not particularly limited and can be appropriately selected from those usually used. For example, borohydride metal salt, aluminum hydride salt, alkanolamine, aliphatic amine, heterocyclic amine, Aromatic amines, aralkylamines, alcohols, organic acids, reducing sugars, sugar alcohols, sodium sulfite, hydrazine compounds, dextrin, hydroquinone, hydroxylamine, ethylene glycol, glutathione and the like can be mentioned. Among these, reducing sugars, sugar alcohols as derivatives thereof, and ethylene glycol are particularly preferable.
Examples of the borohydride metal salt include sodium borohydride and potassium borohydride.
Examples of the aluminum hydride salt include lithium aluminum hydride, potassium aluminum hydride, cesium aluminum hydride, aluminum beryllium hydride, magnesium aluminum hydride, and calcium aluminum hydride.
Examples of the alkanolamine include diethylaminoethanol, ethanolamine, propanolamine, triethanolamine, dimethylaminopropanol, and the like.
Examples of the aliphatic amine include propylamine, butylamine, dipropyleneamine, ethylenediamine, and triethylenepentamine.
Examples of the heterocyclic amine include piperidine, pyrrolidine, N-methylpyrrolidine, and morpholine.
Examples of the aromatic amine include aniline, N-methylaniline, toluidine, anisidine, and phenetidine.
Examples of the aralkylamine include benzylamine, xylenediamine, and N-methylbenzylamine.
As said alcohol, methanol, ethanol, 2-propanol etc. are mentioned, for example.
Examples of the organic acids include citric acid, malic acid, tartaric acid, citric acid, succinic acid, ascorbic acid, and salts thereof.
Examples of the reducing saccharide include glucose, galactose, mannose, fructose, sucrose, maltose, raffinose, stachyose and the like.
Examples of the sugar alcohols include sorbitol.

  Depending on the reducing agent, it may function as a dispersion additive or a solvent as a function, and can be preferably used in the same manner.

In the production of the metal nanowire, it is preferable to add a dispersion additive and a halogen compound or metal halide fine particles.
The timing of the addition of the dispersion additive and the halogen compound may be before or after the addition of the reducing agent, and may be before or after the addition of metal ions or metal halide fine particles, but is better in monodispersity. In order to obtain metal nanowires, it is preferable to add the halogen compound in two or more stages.

The dispersion additive is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an amino group-containing compound, a thiol group-containing compound, a sulfide group-containing compound, an amino acid or a derivative thereof, a peptide compound, and a polysaccharide. Synthetic polymers, gels derived from these, and the like. Among these, gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, polyalkyleneamine, partial alkyl ester of polyacrylic acid, polyvinyl pyrrolidone, and polyvinyl pyrrolidone copolymer are particularly preferable.
For the structure that can be used as the dispersion additive, for example, the description of “Encyclopedia of Pigments” (edited by Seijiro Ito, published by Asakura Shoin Co., Ltd., 2000) can be referred to.
Moreover, the shape of the metal nanowire obtained can also be changed with the kind of dispersion additive to be used.

The halogen compound is not particularly limited as long as it is a compound containing bromine, chlorine, or iodine, and can be appropriately selected according to the purpose. For example, sodium bromide, sodium chloride, sodium iodide, potassium iodide Compounds that can be used in combination with alkali halides such as potassium bromide, potassium chloride, potassium iodide and the following dispersion additives are preferred.
Some halogen compounds may function as a dispersion additive, but can be preferably used in the same manner.

  As an alternative to the halogen compound, silver halide fine particles may be used, or both a halogen compound and silver halide fine particles may be used.

  The dispersant and the halogen compound may be used in the same substance. Examples of the compound in which the dispersant and the halogen compound are used in combination include, for example, HTAB (hexadecyl-trimethylammonium bromide) containing an amino group and a bromide ion, HTAC (hexadecyl-trimethylammonium chloride) containing an amino group and a chloride ion, and an amino group. And bromide or chloride ion containing dodecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, stearyltrimethylammonium bromide, stearyltrimethylammonium chloride, decyltrimethylammonium bromide, decyltrimethylammonium chloride, dimethyldistearylammonium bromide, dimethyldistearylammonium chloride , Dilauryl dimethyl ammonium bromide, dilauryl dimethyl ammonium Umukurorido, dimethyl dipalmityl ammonium bromide, dimethyl dipalmityl ammonium chloride, and the like.

  The desalting treatment can be performed by techniques such as ultrafiltration, dialysis, gel filtration, decantation, and centrifugation after forming metal nanowires.

<< Metal Nanotubes >>
-Material-
There is no restriction | limiting in particular as a material of the said metal nanotube, What kind of metal may be sufficient, For example, the material of the above-mentioned metal nanowire etc. can be used.

-Shape-
The shape of the metal nanotube may be a single layer or a multilayer, but a single layer is preferable in terms of excellent conductivity and thermal conductivity.

-Average minor axis length, average major axis length, thickness-
The thickness of the metal nanotube (difference between the outer diameter and the inner diameter) is preferably 3 nm to 80 nm, and more preferably 3 nm to 30 nm.
When the thickness is less than 3 nm, the oxidation resistance is deteriorated and the durability may be deteriorated. When the thickness is more than 80 nm, scattering due to the metal nanotube may occur.
The average major axis length of the metal nanotube is preferably 1 μm to 40 μm, more preferably 3 μm to 35 μm, and still more preferably 5 μm to 30 μm.

-Manufacturing method-
There is no restriction | limiting in particular as a manufacturing method of the said metal nanotube, According to the objective, it can select suitably, For example, the method as described in the US application publication 2005/0056118 grade | etc., Etc. can be used.

<< Carbon nanotube >>
The carbon nanotube (CNT) is a substance in which a graphite-like carbon atomic surface (graphene sheet) is a single-layer or multilayer coaxial tube. The single-walled carbon nanotubes are called single-walled nanotubes (SWNT), the multi-walled carbon nanotubes are called multi-walled nanotubes (MWNT), and the double-walled carbon nanotubes are also called double-walled nanotubes (DWNT). In the conductive fiber used in the present invention, the carbon nanotube may be a single wall or a multilayer, but a single wall is preferable from the viewpoint of excellent conductivity and thermal conductivity.

-Manufacturing method-
The carbon nanotube production method is not particularly limited and can be appropriately selected depending on the purpose. For example, catalytic hydrogen reduction of carbon dioxide, arc discharge method, laser evaporation method, thermal CVD method, plasma CVD method, Known means such as a vapor phase growth method and a HiPco method in which carbon monoxide is reacted with an iron catalyst at a high temperature and high pressure to grow in a vapor phase can be used.
In addition, the carbon nanotubes obtained by these methods have been highly purified to remove residues such as by-products and catalytic metals by methods such as washing, centrifugation, filtration, oxidation, and chromatography. It is preferable at the point which can obtain a carbon nanotube.

-Aspect ratio-
The aspect ratio of the conductive fiber is preferably 10 or more. The aspect ratio generally means the ratio between the long side and the short side of a fibrous material (ratio of average major axis length / average minor axis length).
There is no restriction | limiting in particular as a measuring method of the said aspect ratio, According to the objective, it can select suitably, For example, the method etc. which measure with an electron microscope etc. are mentioned.
When measuring the aspect ratio of the conductive fiber with an electron microscope, it is only necessary to confirm whether the aspect ratio of the conductive fiber is 10 or more with one field of view of the electron microscope. In addition, the aspect ratio of the entire conductive fiber can be estimated by measuring the major axis length and the minor axis length of the conductive fiber separately.
In addition, when the said conductive fiber is a tube shape, the outer diameter of this tube is used as a diameter for calculating the said aspect ratio.

The aspect ratio of the conductive fiber is not particularly limited as long as it is 10 or more, and can be appropriately selected according to the purpose, but is preferably 50 to 1,000,000, and 100 to 1,000,000. More preferred.
When the aspect ratio is less than 10, network formation by the conductive fibers may not be performed and sufficient conductivity may not be obtained. When the aspect ratio exceeds 1,000,000, the conductive fibers may be formed or handled thereafter. In this case, since the conductive fibers are entangled and aggregate before film formation, a stable liquid may not be obtained.

-Ratio of conductive fibers having an aspect ratio of 10 or more-
The ratio of the conductive fibers having an aspect ratio of 10 or more is preferably 50% or more, more preferably 60% or more, and particularly preferably 75% or more in volume ratio in the total conductive composition. Hereinafter, the ratio of these conductive fibers may be referred to as “the ratio of conductive fibers”.
If the ratio of the conductive fibers is less than 50%, the conductive material contributing to the conductivity may decrease and the conductivity may decrease. At the same time, a voltage concentration may occur because a dense network cannot be formed. , Durability may be reduced. In addition, particles having a shape other than the conductive fiber are not preferable because they do not greatly contribute to conductivity and have absorption. In particular, in the case of metal, transparency may be deteriorated when plasmon absorption such as a spherical shape is strong.

  Here, the ratio of the conductive fibers is, for example, when the conductive fibers are silver nanowires, the silver nanowire aqueous dispersion is filtered to separate the silver nanowires from the other particles. The ratio of the conductive fibers can be determined by measuring the amount of silver remaining on the filter paper and the amount of silver that has passed through the filter paper using an ICP emission analyzer. By observing the conductive fibers remaining on the filter paper with a TEM, observing the short axis lengths of 300 conductive fibers and examining their distribution, the short axis length is 200 nm or less and the long axis length is It confirms that it is an electroconductive fiber whose length is 1 micrometer or more. Note that the filter paper has a short axis length of 200 nm or less in the TEM image and the longest axis of particles other than conductive fibers having a long axis length of 1 μm or more is measured, and is at least twice the longest axis. And it is preferable to use the thing of the length below the shortest length of the long axis of an electroconductive fiber.

  Here, the average minor axis length and the average major axis length of the conductive fiber can be obtained by observing a TEM image or an optical microscope image using, for example, a transmission electron microscope (TEM) or an optical microscope. In the present invention, the average minor axis length and the average major axis length of the conductive fibers are obtained by observing 300 conductive fibers with a transmission electron microscope (TEM) and obtaining the average value. is there.

<< Binder >>
The binder is an organic high molecular polymer, and at least one group (for example, carboxyl group, phosphate group) that promotes alkali solubility in a molecule (preferably a molecule having an acrylic copolymer as a main chain). , Sulfonic acid groups, etc.) can be selected appropriately from alkali-soluble resins.
Among these, those that are soluble in an organic solvent and that can be developed with a weak alkaline aqueous solution are preferable, and those that have an acid-dissociable group and become alkali-soluble when the acid-dissociable group is dissociated by the action of an acid. Particularly preferred.
Here, the acid dissociable group represents a functional group that can dissociate in the presence of an acid.

  For production of the binder, for example, a known radical polymerization method can be applied. Polymerization conditions such as temperature, pressure, type and amount of radical initiator, type of solvent, etc. when producing an alkali-soluble resin by the radical polymerization method can be easily set by those skilled in the art, and the conditions are determined experimentally. Can be determined.

The linear organic polymer is preferably a polymer having a carboxylic acid in the side chain (photosensitive resin having an acidic group).
Examples of the polymer having a carboxylic acid in the side chain include, for example, JP-A-59-44615, JP-B-54-34327, JP-B-58-12777, JP-B-54-25957, JP-A-59-53836, A methacrylic acid copolymer, an acrylic acid copolymer, an itaconic acid copolymer, a crotonic acid copolymer, a maleic acid copolymer, a partial ester, as described in JP-A-59-71048 A maleic acid copolymer, etc., an acidic cellulose derivative having a carboxylic acid in the side chain, a polymer having a hydroxyl group with an acid anhydride added, and a polymer having a (meth) acryloyl group in the side chain Polymers are also preferred.

Among these, benzyl (meth) acrylate / (meth) acrylic acid copolymers and multi-component copolymers composed of benzyl (meth) acrylate / (meth) acrylic acid / other monomers are particularly preferable.
Furthermore, a high molecular polymer having a (meth) acryloyl group in the side chain and a multi-component copolymer comprising (meth) acrylic acid / glycidyl (meth) acrylate / other monomers are also useful. The polymer can be used by mixing in an arbitrary amount.

  In addition to the above, 2-hydroxypropyl (meth) acrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer, 2-hydroxy-3-phenoxypropyl acrylate / polymethyl described in JP-A-7-140654 Methacrylate macromonomer / benzyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / methyl methacrylate / methacrylic acid copolymer, 2-hydroxyethyl methacrylate / polystyrene macromonomer / benzyl methacrylate / methacrylic acid copolymer Coalescence, etc.

  As specific structural units in the alkali-soluble resin, (meth) acrylic acid and other monomers copolymerizable with the (meth) acrylic acid are suitable.

Examples of other monomers copolymerizable with the (meth) acrylic acid include alkyl (meth) acrylates, aryl (meth) acrylates, and vinyl compounds. In these, the hydrogen atom of the alkyl group and aryl group may be substituted with a substituent.
Examples of the alkyl (meth) acrylate or aryl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and pentyl (meth). Acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, tolyl (meth) acrylate, naphthyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meta ) Acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.

Examples of the vinyl compound include styrene, α-methylstyrene, vinyl toluene, glycidyl methacrylate, acrylonitrile, vinyl acetate, N-vinyl pyrrolidone, tetrahydrofurfuryl methacrylate, polystyrene macromonomer, polymethyl methacrylate macromonomer, CH ₂ ═CR. ¹ R ² , CH ₂ = C (R ¹ ) (COOR ³ ) [wherein R ¹ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ² represents an aromatic hydrocarbon ring having 6 to 10 carbon atoms. R ³ represents an alkyl group having 1 to 8 carbon atoms or an aralkyl group having 6 to 12 carbon atoms. ] And the like. These may be used individually by 1 type and may use 2 or more types together.

The weight average molecular weight of the binder is preferably from 1,000 to 500,000, more preferably from 3,000 to 300,000, and even more preferably from 5,000 to 200,000, from the viewpoints of alkali dissolution rate, film physical properties and the like. .
Here, the weight average molecular weight is measured by gel permeation chromatography and can be determined using a standard polystyrene calibration curve.

  The content of the binder is preferably 25% by mass to 80% by mass with respect to the entire conductive layer, more preferably 30% by mass to 75% by mass, and still more preferably 40% by mass to 70% by mass. When the content is in the range, both developability and conductivity of the metal nanowire can be achieved.

-Photosensitive compound-
The said photosensitive compound means the compound which provides the function which forms an image by exposure, or gives the trigger to it. Specific examples include (1) a compound that generates acid upon exposure (photoacid generator), (2) a photosensitive quinonediazide compound, and (3) a photoradical generator. These may be used individually by 1 type and may use 2 or more types together. Moreover, a sensitizer etc. can also be used together for sensitivity adjustment.

-(1) Photoacid generator--
(1) As the photoacid generator, a photoinitiator for photocationic polymerization, a photoinitiator for radical photopolymerization, a photodecolorant for dyes, a photochromic agent, an actinic ray used for a micro resist, etc. Alternatively, known compounds that generate an acid upon irradiation with radiation and a mixture thereof can be appropriately selected and used.

  The (1) photoacid generator is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, Examples include disulfone and o-nitrobenzyl sulfonate. Among these, imide sulfonate, oxime sulfonate, and o-nitrobenzyl sulfonate, which are compounds that generate sulfonic acid, are particularly preferable.

Further, a group capable of generating an acid upon irradiation with actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the resin, such as US Pat. No. 3,849,137, German Patent No. 3914407. Description, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853 The compounds described in JP-A-63-146029, etc. can be used.
Furthermore, compounds capable of generating an acid by light described in each specification such as US Pat. No. 3,779,778 and European Patent 126,712 can also be used.

-(2) Quinonediazide compound--
The (2) quinonediazide compound can be obtained, for example, by subjecting 1,2-quinonediazidesulfonyl chlorides, hydroxy compounds, amino compounds and the like to a condensation reaction in the presence of a dehydrochlorinating agent.

The blending amount of the (1) photoacid generator and the (2) quinonediazide compound is based on the difference in dissolution rate between the exposed part and the unexposed part, and the allowable range of sensitivity, with respect to 100 parts by weight of the total amount of the binder. It is preferably 1 part by mass to 100 parts by mass, and more preferably 3 parts by mass to 80 parts by mass.
The (1) photoacid generator and the (2) quinonediazide compound may be used in combination.

In the present invention, among the (1) photoacid generators, compounds that generate sulfonic acid are preferable, and the following oxime sulfonate compounds are particularly preferable from the viewpoint of high sensitivity.

When a compound having a 1,2-naphthoquinonediazide group is used as the (2) quinonediazide compound, high sensitivity and good developability are obtained.
Among the above (2) quinonediazide compounds, the following compounds, in which D is independently a hydrogen atom or a 1,2-naphthoquinonediazide group, are preferred from the viewpoint of high sensitivity.

-(3) Photoradical generator--
The photoradical generator has a function of directly absorbing light or being photosensitized to cause a decomposition reaction or a hydrogen abstraction reaction to generate a polymerization active radical. The photo radical generator preferably has absorption in a wavelength region of 300 nm to 500 nm.

  The said photoradical generator may be used individually by 1 type, and may use 2 or more types together. The content of the photo radical generator is preferably 0.1% by mass to 50% by mass and more preferably 0.5% by mass to 30% by mass with respect to the total solid content of the coating liquid for the conductive layer. 1% by mass to 20% by mass is more preferable. In the numerical range, good sensitivity and pattern formability can be obtained.

  There is no restriction | limiting in particular as said photoradical generator, According to the objective, it can select suitably, For example, the compound group as described in Unexamined-Japanese-Patent No. 2008-268884 is mentioned. Among these, triazine compounds, acetophenone compounds, acylphosphine (oxide) compounds, oxime compounds, imidazole compounds, and benzophenone compounds are particularly preferable from the viewpoint of exposure sensitivity.

  As the photoradical generator, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1 is used from the viewpoints of exposure sensitivity and transparency. -Butanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2 , 2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, N, N-diethylaminobenzophenone, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (o-benzoyloxime)] is preferred.

In the conductive layer coating solution, a photoradical generator and a chain transfer agent may be used in combination to improve exposure sensitivity.
Examples of the chain transfer agent include N, N-dialkylaminobenzoic acid alkyl esters such as N, N-dimethylaminobenzoic acid ethyl ester, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, Heterocycles such as N-phenylmercaptobenzimidazole, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione -Functional mercapto compounds such as pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate), 1,4-bis (3-mercaptobutyryloxy) butane Etc. These may be used individually by 1 type and may use 2 or more types together.
The content of the chain transfer agent is preferably 0.01% by mass to 15% by mass, more preferably 0.1% by mass to 10% by mass with respect to the total solid content of the coating liquid for the conductive layer, and 0.5% More preferably, the content is 5% by mass to 5% by mass.

-Other ingredients-
Examples of the other components include various additives such as a crosslinking agent, a dispersing agent, a solvent, a surfactant, an antioxidant, an antisulfurizing agent, a metal corrosion inhibitor, a viscosity modifier, and an antiseptic.

-Crosslinking agent-
The crosslinking agent is a compound that forms a chemical bond by free radical or acid and heat to cure the conductive layer, and is substituted with at least one group selected from, for example, a methylol group, an alkoxymethyl group, and an acyloxymethyl group. Melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, phenol compounds or phenol ether compounds, epoxy compounds, oxetane compounds, thioepoxy compounds, isocyanate compounds, or azide compounds; methacryloyl groups or And compounds having an ethylenically unsaturated group containing an acryloyl group. Among these, an epoxy compound, an oxetane compound, and a compound having an ethylenically unsaturated group are particularly preferable in terms of film properties, heat resistance, and solvent resistance.
Moreover, the said oxetane resin can be used individually by 1 type or in mixture with an epoxy resin. In particular, when used in combination with an epoxy resin, the reactivity is high, which is preferable from the viewpoint of improving film properties.

  The content of the crosslinking agent is preferably 1 part by weight to 250 parts by weight, and more preferably 3 parts by weight to 200 parts by weight with respect to 100 parts by weight of the total amount of the binder.

-Dispersant-
The dispersant is used for preventing and dispersing the conductive fibers. The dispersant is not particularly limited as long as the conductive fibers can be dispersed, and can be appropriately selected according to the purpose. For example, commercially available low molecular pigment dispersants and polymer pigment dispersants can be used. In particular, a polymer dispersant having a property of adsorbing to conductive fibers is preferably used. For example, polyvinylpyrrolidone, BYK series (manufactured by Big Chemie), Solsperse series (manufactured by Nippon Lubrizol, etc.), Ajisper series ( Ajinomoto Co., Inc.).
As content of the said dispersing agent, 0.1 mass part-50 mass parts are preferable with respect to 100 mass parts of said binders, 0.5 mass part-40 mass parts are more preferable, and 1 mass part-30 mass parts are. Particularly preferred.
When the content is less than 0.1 parts by mass, the conductive fibers may aggregate in the dispersion, and when it exceeds 50 parts by mass, a stable liquid film cannot be formed in the coating process. Application unevenness may occur.

--Solvent--
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl lactate , 3-methoxybutanol, water, 1-methoxy-2-propanol, isopropyl acetate, methyl lactate, N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), propylene carbonate, and the like. These may be used individually by 1 type and may use 2 or more types together.

--- Metal corrosion inhibitor ---
There is no restriction | limiting in particular as said metal corrosion inhibitor, Although it can select suitably according to the objective, For example, thiols, azoles, etc. are suitable.
By containing the metal corrosion inhibitor, a further excellent rust prevention effect can be exhibited. While the metal corrosion inhibitor is dissolved in the coating liquid for the conductive layer, it is added in a state dissolved in a suitable solvent or powder, or after the conductive film is formed by the coating liquid for the conductive layer described later, this is subjected to the metal corrosion. It can be applied by dipping in an inhibitor bath.

  The mass ratio (A / B) between the total content A of components other than the conductive fibers in the conductive layer (a single content in the case of only one type) and the content B of the conductive fibers is 0. It is preferable that it is 1-5, and it is more preferable that it is 0.5-3. When the mass ratio (A / B) is less than 0.1, deterioration of optical properties such as conductivity, transmittance and haze due to aggregation of conductive fibers, mechanical strength of the conductive layer, and adhesion to the substrate. Deterioration, in particular, the quality of the pattern obtained by patterning using photolithography (faithful reproducibility of the exposure pattern) may occur. When the mass ratio (A / B) exceeds 5, there may be a decrease in conductivity due to a decrease in the number of contact points between the conductive fibers, and deterioration of optical characteristics such as haze and light transmittance.

There is no restriction | limiting in particular in the said conductive layer, Although it can select suitably according to the objective, It can form by apply | coating the composition for conductive layers on an undercoat layer.
There is no restriction | limiting in particular as a coating method of the said composition for conductive layers, According to the objective, it can select suitably, For example, the apply | coating method, the printing method, the inkjet method etc. are mentioned.
The coating method is not particularly limited and may be appropriately selected depending on the purpose. For example, a roll coating method, a bar coating method, a dip coating method, a spin coating method, a casting method, a die coating method, a blade coating method, a bar coating method, and the like. Examples thereof include a coating method, a gravure coating method, a curtain coating method, a spray coating method, and a doctor coating method.
Examples of the printing method include letterpress (letterpress) printing, stencil (screen) printing, lithographic (offset) printing, and intaglio (gravure) printing.

-Other layers-
In the present invention, when the conductive layer does not contain a photosensitive material (binder, photosensitive compound), it is preferable to have a photosensitive layer between the undercoat layer and the conductive layer or on the conductive layer.
The photosensitive layer contains at least a binder, and contains a photosensitive compound and, if necessary, other components.
There is no restriction | limiting in particular as said binder and a photosensitive compound, Although it can select suitably according to the objective, For example, the thing similar to the said conductive layer can be used.
There is no restriction | limiting in particular in the thickness of the said photosensitive layer, Although it can select suitably according to the objective, It is preferable that they are 0.01 micrometer-100 micrometers, and it is more preferable that they are 0.05 micrometer-10 micrometers.

The surface resistance of the conductive layer in the conductive material of the present invention is preferably 0.1Ω / □ to 5,000Ω / □, and more preferably 0.1Ω / □ to 1,000Ω / □. The low surface resistance itself is not harmful, but if it is less than 0.1 Ω / □, it may be difficult to obtain a conductor with high light transmittance, and if it exceeds 5,000 Ω / □, There may be a problem that disconnection due to Joule heat generated during energization is likely to occur, a voltage drop occurs upstream and downstream of the wiring, and the area used for the touch panel is limited.
Here, the surface resistance can be measured using, for example, a surface resistance meter (Loresta-GP MCP-T600, manufactured by Mitsubishi Chemical Corporation).

The total visible light transmittance of the conductive layer in the conductive material of the present invention is preferably 85% or more, and more preferably 90% or more. When the total visible light transmittance is less than 85%, the conductive pattern becomes conspicuous when used for an image display medium such as a touch panel, and the image quality is deteriorated or the power consumption is increased to compensate for the decrease in luminance. There may be negative effects such as necessity.
Here, the total visible transmittance can be measured by, for example, a self-recording spectrophotometer (UV2400-PC, manufactured by Shimadzu Corporation).

  The conductive material of the present invention has high permeability, low resistance, improved durability and flexibility, and can be easily patterned. For example, a touch panel, a display electrode, an electromagnetic wave shield, and an organic EL display It is widely applied to electrodes, electrodes for inorganic EL displays, electronic paper, electrodes for flexible displays, integrated solar cells, display elements, and other various devices. Among these, a touch panel and a display device with a touch panel function are particularly preferable.

(Pattern formation method)
The pattern forming method of the present invention exposes and develops the conductive layer in the conductive material of the present invention, and includes an exposure step and a development step, and further includes other steps as necessary. Become.

-Exposure process-
The exposure step is a step of exposing at least a conductive layer in the conductive material of the present invention.
As the exposure method, surface exposure using a photomask may be performed, or scanning exposure using a laser beam may be performed. At this time, refractive exposure using a lens or reflection exposure using a reflecting mirror may be used, and exposure methods such as contact exposure, proximity exposure, reduced projection exposure, and reflection projection exposure can be used.

-Development process-
The developing step is a step of developing at least one of the exposed portion and the non-exposed portion in the conductive layer by applying a solvent.
In the development step, when a photosensitive layer is provided between the substrate and the conductive layer, either the exposed part or the non-exposed part in the photosensitive layer is removed.

As the solvent, an alkaline solution is preferable.
The alkali contained in the alkaline solution is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tetramethylammonium hydroxide, tetraethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, sodium carbonate, Examples thereof include sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, sodium hydroxide, potassium hydroxide and the like.

There is no restriction | limiting in particular as the provision method by the said alkaline solution, According to the objective, it can select suitably, For example, application | coating, immersion, spraying etc. are mentioned. Specifically, a method of immersing the polarizing plate with a conductive layer of the present invention in an alkaline solution, a method of pouring an organic solvent into the polarizing plate with a conductive layer of the present invention using a shower or spray, the above of the present invention For example, a method of applying to a polarizing plate with a conductive layer using a napkin or the like in which an alkaline solution is immersed is used. Among these, the method of immersing the polarizing plate with a conductive layer of the present invention in an alkaline solution is particularly preferable.
There is no restriction | limiting in particular in the immersion time of the said alkaline solution, Although it can select suitably according to the objective, It is preferable that it is 10 seconds-5 minutes.

(Touch panel)
The touch panel of the present invention is not particularly limited as long as it has the conductive material (transparent conductor) of the present invention, and can be appropriately selected according to the purpose. For example, a surface capacitive touch panel, a projection electrostatic Examples include a capacitive touch panel and a resistive touch panel. The touch panel includes a so-called touch sensor and a touch pad.
The layer structure of the touch panel sensor electrode part in the touch panel is a bonding method in which two transparent electrodes are bonded, a method in which transparent electrodes are provided on both surfaces of a single substrate, a single-sided jumper or a through-hole method, or a single-area layer method. It is preferable that it is either.

Here, an example of the surface capacitive touch panel will be described with reference to FIG. In FIG. 2, the touch panel 10 has a transparent conductor 12 disposed so as to uniformly cover the surface of the transparent substrate 11 (corresponding to the conductive material of the present invention), and the transparent conductive material at the end of the transparent substrate 11. An electrode terminal 18 for electrical connection with an external detection circuit (not shown) is formed on the body 12.
In FIG. 2, 13 indicates a transparent conductor serving as a shield electrode, 14 and 17 indicate protective films, 15 indicates an intermediate protective film, and 16 indicates an antiglare film.
When an arbitrary point on the transparent conductor 12 is touched with a finger, the transparent conductor 12 is grounded through the human body at the touched point, and changes to a resistance value between each electrode terminal 18 and the ground line. Occurs. The change of the resistance value is detected by the external detection circuit, and the coordinates of the touched point are specified.

Another example of the surface capacitive touch panel will be described with reference to FIG. In FIG. 3, the touch panel 20 includes a transparent conductor 22 (corresponding to the conductive material of the present invention), a transparent conductor 23, a transparent conductor 22, and a transparent conductor disposed so as to cover the surface of the transparent substrate 21. An insulating layer 24 that insulates the body 23, and an insulating cover layer 25 that generates a capacitance between a contact object such as a finger and the transparent conductor 22 or the transparent conductor 23, and is positioned with respect to the contact object such as a finger Detect. Depending on the configuration, the transparent conductors 22 and 23 may be configured integrally, and the insulating layer 24 or the insulating cover layer 25 may be configured as an air layer.
When the insulating cover layer 25 is touched with a finger or the like, the capacitance value between the finger and the transparent conductor 22 or the transparent conductor 23 changes. This change in capacitance value is detected by the external detection circuit, and the coordinates of the touched point are specified.
Further, with reference to FIG. 4, the touch panel 20 as a projection capacitive touch panel will be schematically described through an arrangement in which the transparent conductor 22 and the transparent conductor 23 are viewed from the plane.
The touch panel 20 is provided with a plurality of transparent conductors 22 capable of detecting positions in the X-axis direction and a plurality of transparent conductors 23 in the Y-axis direction so as to be connectable to external terminals. The transparent conductor 22 and the transparent conductor 23 are in contact with a plurality of contact objects such as fingertips, and contact information can be input at multiple points.
When an arbitrary point on the touch panel 20 is touched with a finger, the coordinates in the X-axis direction and the Y-axis direction are specified with high positional accuracy.
In addition, as other structures, such as a transparent substrate and a protective layer, the structure of the said surface type capacitive touch panel can be selected suitably, and can be applied. Moreover, although the example of the pattern of the transparent conductor by the some transparent conductor 22 and the some transparent conductor 23 was shown in the touch panel 20, the shape, arrangement | positioning, etc. are not restricted to these.

An example of the resistive touch panel will be described with reference to FIG. In FIG. 5, the touch panel 30 includes a substrate 31 (corresponding to the conductive material of the present invention) on which a transparent conductor 32 is disposed, a plurality of spacers 36 disposed on the transparent conductor 32, and an air layer 34. Thus, the transparent conductor 33 that can contact the transparent conductor 32 and the transparent film 35 disposed on the transparent conductor 33 are supported and configured.
When the touch panel 30 is touched from the transparent film 35 side, the transparent film 35 is pressed, the pressed transparent conductor 32 and the transparent conductor 33 come into contact with each other, and a potential change at this position is not illustrated. By detecting with a circuit, the coordinates of the touched point are specified.

<Display device with touch panel display function>
The display device with a touch panel display function of the present invention is not particularly limited except that it has the touch panel of the present invention, and can be appropriately selected according to the purpose.
As the display device, a liquid crystal display device is preferable.

Here, as shown in FIG. 6, the display device with a touch panel display function 100 of the present invention combines the conductive material 5 of the present invention and the counter substrate 1 ′ by aligning the positions and press-bonding, and then heat-treating. It is manufactured by injecting liquid crystal and sealing the injection port. At this time, the conductive layer 3 ′ formed on the liquid crystal display device (color filter) 6 may also be the conductive layer 3 in the conductive material of the present invention.
There is no particular limitation on the liquid crystal used in the liquid crystal display device, that is, the liquid crystal compound and the liquid crystal composition, and any liquid crystal compound and liquid crystal composition can be used.

The liquid crystal display device includes a color filter and a backlight, and further includes other members as necessary.
The liquid crystal display device is described in, for example, “Next-generation liquid crystal display technology (edited by Tatsuo Uchida, published by Investigative Research Institute, Inc., 1994)”. The liquid crystal display device to which the present invention can be applied is not particularly limited, and can be applied, for example, to various types of liquid crystal display devices described in the “next-generation liquid crystal display technology”.

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

In the following examples, the average thickness of the undercoat layer, the average thickness of the conductive layer, and the average thickness of the hard coat layer were measured as follows.
<Measurement of average thickness of undercoat layer, average thickness of conductive layer, and average thickness of hard coat layer>
It can be measured by taking out a cross section of the material by microtome cutting and observing it with an SEM, or by observing a section prepared with a microtome after embedding with an epoxy resin. The average thickness of each of these layers is an average value measured at 10 points.

(Synthesis Example 1)
<Synthesis of Binder (A-1)>
7.79 g of methacrylic acid (MAA) and 37.21 g of benzyl methacrylate (BzMA) are used as monomer components constituting the copolymer, and 0.5 g of azobisisobutyronitrile (AIBN) is used as a radical polymerization initiator. These were polymerized in 55.00 g of solvent propylene glycol monomethyl ether acetate (PGMEA) to obtain a PGMEA solution (solid content concentration: 45% by mass) of binder (A-1) represented by the following formula. . The polymerization temperature was adjusted to a temperature of 60 ° C to 100 ° C.
As a result of measuring the molecular weight using gel permeation chromatography (GPC), the weight average molecular weight (Mw) in terms of polystyrene was 30,000, and the molecular weight distribution (Mw / Mn) was 2.21.

(Preparation Example 1)
-Preparation of silver nanowire aqueous dispersion-
The following additive solutions A, G, and H were prepared in advance.
[Additive liquid A]
0.51 g of silver nitrate powder was dissolved in 50 mL of pure water. Then, 1N ammonia water was added until it became transparent. And pure water was added so that the whole quantity might be 100 mL.
[Additive liquid G]
An additive solution G was prepared by dissolving 0.5 g of glucose powder in 140 mL of pure water.
[Additive liquid H]
Additive solution H was prepared by dissolving 0.5 g of HTAB (hexadecyl-trimethylammonium bromide) powder in 27.5 mL of pure water.

Next, a silver nanowire aqueous dispersion was prepared as follows.
410 mL of pure water was placed in a three-necked flask, and 82.5 mL of additive solution H and 206 mL of additive solution G were added using a funnel while stirring at 20 ° C. (first stage). To this solution, 206 mL of additive solution A was added at a flow rate of 2.0 mL / min and a stirring rotation speed of 800 rpm (second stage). Ten minutes later, 82.5 mL of additive liquid H was added (third stage). Thereafter, the internal temperature was raised to 75 ° C. at 3 ° C./min. Then, the stirring rotation speed was reduced to 200 rpm and heated for 5 hours.
After cooling the obtained aqueous dispersion, an ultrafiltration module SIP1013 (manufactured by Asahi Kasei Co., Ltd., molecular weight cut off 6,000), a magnet pump, and a stainless steel cup were connected with a silicone tube to obtain an ultrafiltration device. .
The silver nanowire dispersion (aqueous solution) was put into a stainless steel cup, and ultrafiltration was performed by operating a pump. When the filtrate from the module reached 50 mL, 950 mL of distilled water was added to the stainless steel cup for washing. The above washing was repeated until the conductivity reached 50 μS / cm or less, and then concentrated to obtain a silver nanowire aqueous dispersion.
About the obtained silver nanowire of Preparation Example 1, the average minor axis length, the average major axis length, the ratio of silver nanowires having an aspect ratio of 10 or more, and the silver nanowire minor axis length were as follows: The coefficient of variation was measured. The results are shown in Table 1.

<Average minor axis length (average diameter) and average major axis length of silver nanowires>
Using a transmission electron microscope (TEM; JEM-2000FX, manufactured by JEOL Ltd.), 300 silver nanowires were observed, and the average minor axis length and average major axis length of the silver nanowires were determined.

<Coefficient of variation of minor axis length of silver nanowires>
Using a transmission electron microscope (TEM; JEM-2000FX, manufactured by JEOL Ltd.), 300 short axis lengths of the silver nanowires were observed, and the amount of silver transmitted through the filter paper was measured. Of silver nanowires having a major axis length of 5 μm or more was determined as the ratio (%) of silver nanowires having an aspect ratio of 10 or more.
The silver nanowires were separated when determining the ratio of silver nanowires using a membrane filter (Millipore, FALP 02500, pore size 1.0 μm).

(Example 1)
<Sample No. Production of 101>
<< Preparation of undercoat layer >>
A commercially available biaxially stretched heat-fixed polyethylene terephthalate (PET) substrate having a thickness of 100 μm is subjected to a corona discharge treatment of 8 W / m ² ·, and an undercoat layer coating solution having the following composition is applied and dried to obtain an average thickness. An undercoat layer of 0.1 μm was formed.

-Composition of coating solution for undercoat layer-
・ Butyl acrylate: 40% by mass
・ Styrene ... 20% by mass
・ Glycidyl acrylate ・ ・ ・ 40% by mass
Copolymer latex having the above composition was mixed with 0.5% by mass of hexamethylene-1,6-bis (ethylene urea) to prepare an undercoat layer coating solution.

<< Preparation of conductive layer >>
-Preparation of MFG dispersion (Ag-1) of silver nanowires-
Polyvinylpyrrolidone (K-30, manufactured by Wako Pure Chemical Industries, Ltd.) and 1-methoxy-2-propanol (MFG) are added to the silver nanowire aqueous dispersion of Preparation Example 1, and after centrifuging, decantation is performed. The water in the supernatant was removed, MFG was added, redispersion was performed, and the operation was repeated three times to obtain an MFG dispersion (Ag-1) of silver nanowires. The final MFG addition amount was adjusted so that the silver content was 1% by mass of silver.

-Preparation of composition for negative conductive layer-
0.241 parts by mass of the binder (A-1) of Synthesis Example 1, 0.252 parts by mass of KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.), 0.0252 parts by mass of IRGACURE 379 (manufactured by Ciba Specialty Chemicals), crosslinking EHPE-3150 (manufactured by Daicel Chemical Co., Ltd.) 0.0237 parts by mass, Megafac F781F (manufactured by DIC Corporation) 0.0003 parts by mass, propylene glycol monomethyl ether acetate (PGMEA) 0.9611 parts by mass, and 1 44.3 parts by mass of methoxy-2-propanol (MFG) and 54.1 parts by mass of the MFG dispersion (Ag-1) of the silver nanowire were added and stirred to prepare a negative conductive layer composition.
Here, the mass ratio (A / B) of the total content A of the components other than the conductive fibers and the content B of the conductive fibers was 0.6.

-Formation of conductive layer-
The obtained negative conductive layer composition was coated on a polyethylene terephthalate (PET) film having a thickness of 75 μm so that the applied silver amount was 0.05 g / m ² , and dried to obtain an average thickness of 0.1 μm. A conductive layer was formed.

<< Preparation of hard coat layer >>
A hard coat liquid (TOP, manufactured by Muromachi Technos) is applied to the surface of the polyethylene terephthalate (PET) substrate that does not have a conductive layer, and dried at 80 ° C. for 10 minutes to form a hard coat layer having an average thickness of 1 μm. Formed. As described above, the sample No. 101 conductive materials were produced.

<Sample No. 102>
Sample No. In Sample 101, sample No. 101 was prepared except that the average thickness of the undercoat layer was 0.5 μm. In the same manner as in Sample 101, Sample No. 102 conductive materials were produced.

<Sample No. 103>
Sample No. In Sample 101, sample No. 101 was prepared except that the average thickness of the undercoat layer was 1 μm. In the same manner as in Sample 101, Sample No. 103 conductive materials were produced.

<Sample No. 104>
Sample No. In Sample 101, sample No. 101 was prepared except that the average thickness of the undercoat layer was 5 μm. In the same manner as in Sample 101, Sample No. 104 conductive materials were produced.

<Sample No. 105>
Sample No. In Sample 101, sample No. 101 was prepared except that the average thickness of the undercoat layer was 15 μm. In the same manner as in Sample 101, Sample No. 105 conductive materials were produced.

<Sample No. 106>
Sample No. 103, except that the conductive layer was formed to have an average thickness of 0.5 μm. 103, sample No. 106 conductive materials were produced.

<Sample No. 107>
Sample No. 103, except that the conductive layer was formed to have an average thickness of 0.05 μm. 103, sample No. 107 conductive materials were produced.

<Sample No. 108>
Sample No. 103, except that the average thickness of the undercoat layer was 0.8 μm. 103, sample No. 108 conductive materials were produced.

<Sample No. 109>
Sample No. In sample 101, sample no. In the same manner as in Sample 101, Sample No. 109 conductive materials were produced.

<Sample No. 110>
Sample No. 101, except that the average thickness of the conductive layer was 0.2 μm and the undercoat layer and the hard coat layer were not provided. In the same manner as in Sample 101, Sample No. 110 conductive materials were produced.

<Sample No. 111>
Sample No. 101, except that the average thickness of the undercoat layer was 20 μm. In the same manner as in Sample 101, Sample No. 111 conductive materials were produced.

<Sample No. 112>
Sample No. In Sample 101, sample No. 101 was prepared except that the average thickness of the undercoat layer was 0.05 μm. In the same manner as in Sample 101, Sample No. 112 conductive materials were produced.

<Sample No. 113>
Sample No. 103, except that the conductive layer was formed so that the average thickness was 2 μm. 103, sample No. 113 conductive materials were produced.

<Sample No. 114>
Sample No. No. 103, except that the average thickness of the hard coat layer was 8 μm. 103, sample No. 114 conductive materials were produced.

<Sample No. 115>
Sample No. No. 103, except that the average thickness of the hard coat layer was 0.3 μm. 103, sample No. 115 conductive materials were produced.

<Sample No. 116>
On the opposite side of the ITO film of the ITO film (product number 6392281, manufactured by Aldrich), the sample No. In the same manner as the hard coat layer application of No. 101, a hard coat layer was formed. 116 conductive materials were produced.

-Patterning process-
The diamond layer patterning process as shown in FIG. 4 was performed on the produced conductive layer of each conductive material by the following method.
[Patterning conditions]
High pressure mercury lamp i line (365 nm) was exposed to 100 mJ / cm ² (illuminance 20 mW / cm ² ) from above the mask. The exposed substrate was subjected to shower development for 30 seconds with a developer in which 5 g of sodium bicarbonate and 2.5 g of sodium carbonate were dissolved in 5,000 g of pure water. The shower pressure was 0.04 MPa, and the time until the stripe pattern appeared was 15 seconds. Next, it rinsed with the shower of pure water.

  Next, each of the obtained conductive materials was evaluated for light transmittance, surface resistance, curling property, and flexibility as follows. The results are shown in Table 2.

<Measurement of light transmittance>
Each obtained conductive material was measured at a measurement angle of 0 ° with respect to the CIE visibility function y under a C light source by using a haze guard plus manufactured by Gardner.

<Measurement of surface resistance>
The surface resistance of each obtained conductive material was measured using a surface resistance meter (Loresta-GP MCP-T600, manufactured by Mitsubishi Chemical Corporation).

<Curl properties>
Each of the obtained conductive materials was cut into a size of 10 cm × 30 cm, and the amount of warpage from the horizontal plane when the conductive layer was placed on the horizontal plane was measured with a ruler and evaluated. The case where the film cut out when viewed from the side has a concave shape is defined as “+”, and the case where the film has a convex shape is defined as “−”.
〔Evaluation criteria〕
○: Warpage amount ≦ ± 10mm
Δ: ± 10 mm <warping amount ≦ ± 30 mm
×: Warpage amount> ± 30 mm

<Flexibility>
The obtained surface of each conductive material provided with a conductive layer was turned outside, wound around a metal rod having a diameter of 9 mm, and allowed to stand for 15 seconds. The conductivity of the conductive layer of each conductive material before and after winding was measured using a surface resistance meter (Loresta-GP MCP-T600, manufactured by Mitsubishi Chemical Corporation), and the rate of resistance change was calculated from the following formula. evaluated. In addition, flexibility shows that it is so excellent that the number of resistance change rates is small.
Resistance change rate (%) = (surface resistance after winding / surface resistance before winding) × 100
〔Evaluation criteria〕
“1”: The rate of change in resistance is 300% or more, which is a practically problematic level. “2”: The rate of change in resistance is less than 300%, 150% or more, which is a practically problematic level. “3”: Resistance The rate of change is less than 150% and 130% or more, which is a level that is not a problem in practice. “4”: The rate of change in resistance is less than 130% and is a level that is not a problem in practice. %, A level that is practically acceptable

(Example 2)
-Fabrication of touch panel-
Sample No. Using 108 conductive materials, “Latest Touch Panel Technology” (issued July 6, 2009, Techno Times Co., Ltd.), supervised by Yuji Mitani, “Touch Panel Technology and Development”, CMC Publishing (issued in December 2004) The touch panel was produced by the method described in “FPD International 2009 Forum T-11 Lecture Textbook”, “Cypress Semiconductor Corporation Application Note AN2292”, and the like.
When the manufactured touch panel is used, it is excellent in visibility by improving the light transmittance, and for input of characters etc. or screen operation by at least one of bare hands, gloves-fitted hands, pointing tools by improving conductivity It was found that a touch panel with excellent responsiveness can be manufactured.

  The conductive material of the present invention is excellent in all of light transmittance, conductivity, flexibility, and handling properties, and has improved curl balance. For example, touch panel, antistatic for display, electromagnetic wave shield, organic EL display It can be used for a wide range of electrodes, inorganic EL display electrodes, electronic paper, flexible display electrodes, flexible display antistatic films, solar cells, and other various devices.

DESCRIPTION OF SYMBOLS 1 Base material 2 Undercoat layer 3 Conductive layer 4 Hard coat layer 5 Conductive material 6 Liquid crystal display device 10, 20, 30 Touch panel 11, 21, 31 Transparent substrate 12, 13, 22, 23, 32, 33 Transparent conductor 24 Insulating layer 25 Insulating cover layer 14, 17 Protective film 15 Intermediate protective film 16 Antiglare film 18 Electrode terminal 33 Spacer 34 Air layer 35 Transparent film 36 Spacer 100 Display device with touch panel function

Claims (14)

A base material, an undercoat layer on one surface of the base material, and a conductive layer containing at least conductive fibers in this order, and a hard coat layer on the other surface of the base material,
The conductive layer has an average thickness of 0.01 μm to 1 μm,
The undercoat layer has an average thickness of 0.1 μm to 15 μm,
The conductive material, wherein an average thickness of the hard coat layer is 0.5 μm to 5 μm.   The conductive material according to claim 1, wherein the conductive layer has an average thickness of 0.05 μm to 0.5 μm.   The conductive material according to claim 1, wherein the average thickness A of the conductive layer and the average thickness B of the hard coat layer satisfy the following formula: [(A / B) × 100] ≦ 30%.   The conductive material according to claim 1, wherein the average thickness C of the undercoat layer and the average thickness B of the hard coat layer satisfy the following formula: 60% ≦ [(C / B) × 100].   The conductive material according to claim 4, wherein the following formula is satisfied: 60% ≦ [(C / B) × 100] ≦ 150%.   The conductive material according to any one of claims 1 to 5, wherein a mass ratio of components other than the conductive fibers in the conductive layer to the conductive fibers is 0.1 to 5.   The conductive material according to claim 1, wherein the conductive fiber is a metal nanowire.   The conductive material according to claim 7, wherein the metal nanowire is made of any of silver and an alloy of silver and a metal other than silver.   The conductive material according to claim 7, wherein the metal nanowire has an average minor axis length of 100 nm or less and an average major axis length of 2 μm or more.   The conductive material according to claim 1, wherein the total visible light transmittance in the conductive layer is 85% or more.   The conductive material according to claim 1, wherein the conductive layer has a surface resistance of 0.1Ω / □ to 5,000Ω / □.   The pattern formation method characterized by exposing and developing with respect to the conductive layer in the electrically-conductive material in any one of Claims 1-11.   A touch panel using the conductive material according to claim 1.   A display device with a touch panel function, comprising the touch panel according to claim 13.