JP2015040316A - Nanoparticle carrying metal nanowire, dispersion, transparent conductive film and production method thereof, as well as touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nanoparticle carrying metal nanowire with which a touch panel having improved black floating prevention (contrast in a bright place) and improved invisibility of an electrode pattern can be produced by suppressing scattering of external light, and to provide a dispersion, a transparent conductive film and a production method of the same, and a touch panel.SOLUTION: A nanoparticle carrying metal nanowire is a metal nanowire carrying a nanoparticle. A dispersion includes the nanoparticle carrying metal nanowire. A transparent conductive film includes the metal nanowire, the nanoparticle carried on the metal nanowire and/or the nanoparticle unevenly distributed in the vicinity of the metal nanowire.

Description

  The present invention relates to a nanoparticle-supported metal nanowire, a dispersion, a transparent conductive film and a method for producing the same, and a touch panel, and in particular, a nanoparticle-supported metal nanowire, a dispersion containing the nanoparticle metal nanowire, and the nanoparticle The present invention relates to a transparent conductive film including a supported metal nanowire and / or a metal nanowire in which nanoparticles are distributed in the vicinity, a manufacturing method thereof, and a touch panel including the transparent conductive film.

  A transparent conductive film provided on the display surface of the display panel, a transparent conductive film of an information input device disposed on the display surface side of the display panel, or the like, such as a transparent conductive film required to transmit light, includes indium tin oxide. Metal oxides such as (ITO) have been used. However, transparent conductive films using metal oxides are expensive to produce because they are sputtered in a vacuum environment, and cracks and delamination are likely to occur due to deformation such as bending and deflection. .

  Therefore, instead of a transparent conductive film using a metal oxide, a transparent conductive film using a metal nanowire that can be formed by coating or printing and has high resistance to bending and bending has been studied. A transparent conductive film using metal nanowires has attracted attention as a next-generation transparent conductive film that does not use indium, which is a rare metal (see, for example, Patent Documents 1 and 2).

However, the transparent conductive film described in Patent Document 1 is reddish, and transparency may be impaired.
Furthermore, when a transparent conductive film using metal nanowires is provided on the display surface side of the display panel, the external display is diffusely reflected on the surface of the metal nanowires, so that the black display on the display panel is displayed slightly brightly. A so-called black floating phenomenon occurs. The black floating phenomenon causes deterioration of display characteristics due to a decrease in contrast.

For the purpose of preventing the occurrence of such black float, a gold nanotube using gold (Au), which hardly causes irregular reflection of light, has been proposed. For the formation of gold nanotubes, first, silver nanowires that easily diffusely reflect light are used as a template, and gold plating is applied thereto. Then, the silver nanowire part used as a template is etched or oxidized and converted into a gold nanotube (for example, refer to Patent Document 3).
In addition, a technique for preventing light scattering by using a metal nanowire and a secondary conductive medium (CNT (carbon nanotube), conductive polymer, ITO, etc.) in combination has been proposed (for example, see Patent Document 2). .

However, in the gold nanotube obtained by the former method, the silver nanowire used as a template is not only wasted as a material, but also a metal material for gold plating is required. Therefore, there is a problem that the material cost becomes high and the manufacturing process becomes high because the process becomes complicated.
In the latter method, since a secondary conductive medium (coloring material) such as CNT, conductive polymer, ITO, or the like is disposed in the opening of the metal nanowire network, there is a problem that transparency may be impaired. .

In order to solve such a problem, a transparent conductive film containing metal nanowires and a conductive material (see, for example, Patent Document 4), and a metal nanowire and a colored compound (dye) adsorbed on the metal nanowires are included. A transparent conductive film (see, for example, Patent Document 5) has been proposed.
However, the transparent conductive film containing the metal nanowires and the conductive material is contained in a state where the conductive material is uniformly dispersed in the transparent conductive film, so that it cannot absorb incident light and scatter external light. There is a problem that it cannot be suppressed. On the other hand, the transparent conductive film containing the metal nanowire and the colored compound (dye) adsorbed on the metal nanowire is merely a monomolecular layer of the colored compound (dye) formed on the surface of the metal nanowire. There is a possibility that external light scattering cannot be sufficiently suppressed. Here, it is possible to suppress external light scattering by aggregating the colored compound (dye) and adhering it to the surface of the metal nanowire, but in this case, it is difficult to aggregate the colored compound (dye) itself. In addition, the colored compound (dye) may be eluted.

Special table 2010-507199 Special table 2010-525526 gazette Special table 2010-525527 JP 2011-29038 A JP 2012-190780 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, a nanoparticle-supported metal nanowire capable of producing a touch panel that can suppress external light scattering and improve black float prevention (light contrast) and electrode pattern invisibility, and the nanoparticle-supported metal Provided are a dispersion containing nanowires, the above-mentioned nanoparticle-supporting metal nanowires, and / or a transparent conductive film containing metal nanowires in which nanoparticles are distributed in the vicinity, a method for producing the same, and a touch panel including the transparent conductive film The purpose is to do.

  As a result of intensive studies to achieve the above object, the present inventor absorbs incident light more by supporting (adsorbing) the nanoparticles larger than the colored compound (dye) on the metal nanowire, The present inventors have found that external light scattering can be suppressed and have completed the present invention.

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 nanoparticle-supported metal nanowire characterized by being a metal nanowire supporting nanoparticles.
In the nanoparticle-supported metal nanowire according to <1>, since the metal nanowire supports the nanoparticle, a single molecule of the nanoparticle is formed around the surface of the metal nanowire, and the incident light is more absorbed. Accordingly, it is possible to manufacture a touch panel that can suppress scattering of external light and improve anti-black float (light contrast) and electrode pattern non-visibility.
Further, in the nanoparticle-supported metal nanowire according to <1>, since the metal nanowire carries nanoparticles larger than the colored compound (dye), the colored compound (dye) is deposited on the surface of the metal nanowire. Rather than analyzing the formation, it can be easily analyzed that the nanoparticles are formed on the surface of the metal nanowire.

  <2> The surface of the nanoparticle is the nanoparticle-supported metal nanowire according to <1> that absorbs light in a visible light region.

  <3> The nanoparticle-supported metal nanowire according to <1> or <2>, wherein the nanoparticle is at least one of a metal particle, a resin particle, and an inorganic particle.

  <4> The nanoparticle-supported metal nanowire according to any one of <1> to <3>, wherein the nanoparticle has an average particle diameter of 1 nm to 100 nm.

<5> A dispersion liquid comprising the nanoparticle-supported metal nanowire according to any one of <1> to <4>.
Since the dispersion liquid according to <5> includes a nanoparticle-supported metal nanowire supporting nanoparticles, a touch panel capable of improving black float prevention (light contrast) and electrode pattern invisibility is manufactured. Can do.

<6> A transparent conductive film comprising metal nanowires, nanoparticles supported on the metal nanowires, and / or nanoparticles unevenly distributed in the vicinity of the metal nanowires.
In the transparent conductive film according to <6>, including metal nanowires, nanoparticles supported on the metal nanowires, and / or nanoparticles unevenly distributed in the vicinity of the metal nanowires, external light It is possible to manufacture a touch panel that can suppress scattering and improve black floating prevention (light contrast) and electrode pattern non-visibility.

<7> A method for producing a transparent conductive film according to <6>, wherein the dispersion film is formed on a substrate using a dispersion liquid containing metal nanowires, a binder, and a solvent. A step of forming, a step of curing the dispersion film formed on the substrate, and a cured product obtained by curing the dispersion film is immersed in a nanoparticle dispersion solution containing nanoparticles and a solvent; Or a step of applying or printing a nanoparticle dispersion solution containing nanoparticles and a solvent on a cured product obtained by curing the dispersion film. .
In the method for producing a transparent conductive film according to <7>, a cured product obtained by curing a dispersion film formed on a substrate using a dispersion containing metal nanowires, a binder, and a solvent. The nanoparticle dispersion solution containing the nanoparticles and the solvent is applied or printed on the cured product obtained by immersing the substrate in a nanoparticle dispersion solution containing the nanoparticles and the solvent, or by curing the dispersion film. A transparent conductive film including metal nanowires, nanoparticles supported on the metal nanowires, and / or nanoparticles unevenly distributed in the vicinity of the metal nanowires can be formed. It is possible to manufacture a touch panel capable of improving the black float prevention (light contrast) and the electrode pattern non-visibility.
Further, in the metal nanowire according to <7>, a dispersion film is formed on a base material using a dispersion liquid containing the metal nanowire, a binder, and a solvent, and the dispersion formed on the base material Since the film is cured, the metal nanowires can be brought into contact with each other with certainty and conductivity can be obtained, thereby improving the conductivity.

<8> A method for producing a transparent conductive film for producing the transparent conductive film according to <6>, wherein the dispersion or nanoparticle, metal nanowire, and binder according to <5>, A method for producing a transparent conductive film, comprising: forming a dispersion film on a substrate using a dispersion containing a solvent; and curing the dispersion film formed on the substrate. is there.
In the method for producing a transparent conductive film according to <8>, a base material using the dispersion liquid according to <5> or a dispersion liquid including nanoparticles, metal nanowires, a binder, and a solvent. Since the dispersion film is formed on the substrate and the dispersion film formed on the substrate is cured, the metal nanowires, the nanoparticles supported on the metal nanowires, and / or the metal nanowires are unevenly distributed. A touch panel capable of forming a transparent conductive film containing nanoparticles and suppressing external light scattering and improving black float prevention (light contrast) and electrode pattern non-visibility. Can do.

<9> A touch panel comprising the transparent conductive film according to <6>.
In the touch panel according to <9>, since it includes a transparent conductive film including metal nanowires carrying nanoparticles, it suppresses scattering of external light, prevents black float (light contrast), and electrode pattern invisibility. Can be improved.

According to the present invention, it is possible to solve the above-described problems and achieve the above-mentioned object, and to suppress the outside light scattering and improve the black float prevention property (light place contrast) and the electrode pattern non-visibility. A nanoparticle-supported metal nanowire capable of manufacturing a simple touch panel, a dispersion containing the nanoparticle-supported metal nanowire, the nanoparticle-supported metal nanowire, and / or a metal nanowire in which nanoparticles are unevenly distributed in the vicinity A transparent conductive film including the same, a method for manufacturing the same, and a touch panel including the transparent conductive film can be provided.
Furthermore, since the touch panel of the present invention uses the transparent conductive film with improved black float, the bright place contrast on the display surface can be improved.

FIG. 1 is a schematic view for explaining a nanoparticle-supported metal nanowire of the present invention. FIG. 2A is a schematic diagram for explaining a linker (small organic molecule) that connects metal nanowires and nanoparticles. FIG. 2B is a schematic diagram for explaining a linker (organic polymer) that connects metal nanowires and nanoparticles. FIG. 3 is a schematic diagram for explaining that nanoparticles are unevenly distributed in the vicinity of metal nanowires in the transparent conductive film of the present invention. FIG. 4 is a schematic view showing a first embodiment of a transparent electrode having a transparent conductive film of the present invention. FIG. 5 is a schematic view showing a second embodiment of a transparent electrode having a transparent conductive film of the present invention. FIG. 6 is a schematic view showing a third embodiment of a transparent electrode having a transparent conductive film of the present invention. FIG. 7 is a schematic view showing a fourth embodiment of a transparent electrode having a transparent conductive film of the present invention. FIG. 8 is a schematic view showing a fifth embodiment of a transparent electrode having a transparent conductive film of the present invention. FIG. 9 is a schematic view showing a cured product obtained in the curing step in the first embodiment of the method for producing a transparent conductive film of the present invention. FIG. 10 is a schematic diagram for explaining a surface treatment step (when a cured product is immersed in a nanoparticle dispersion solution) in the first embodiment of the method for producing a transparent conductive film of the present invention. FIG. 11 is a schematic view showing a cured product after the surface treatment step in the first embodiment of the method for producing a transparent conductive film of the present invention. FIG. 12: is a schematic diagram which shows the transparent conductive film obtained by 1st Embodiment of the manufacturing method of the transparent conductive film of this invention (the 1). FIG. 13: is a schematic diagram which shows the transparent conductive film obtained by 1st Embodiment of the manufacturing method of the transparent conductive film of this invention (the 2). FIG. 14: is a schematic diagram which shows the transparent conductive film obtained by 2nd Embodiment of the manufacturing method of the transparent conductive film of this invention (the 1). FIG. 15: is a schematic diagram which shows the transparent conductive film obtained by 2nd Embodiment of the manufacturing method of the transparent conductive film of this invention (the 2). FIG. 16 is a schematic diagram showing the calendar processing apparatus used in the embodiment of the present application. FIG. 17 is a schematic diagram showing an electrode pattern used in the evaluation of electrode pattern non-visibility in Examples of the present application. FIG. 18 is a photograph showing an SEM image of the transparent conductive film (silver nanowire layer) surface of the transparent electrode obtained in Comparative Example 1. FIG. 19 is a photograph showing an SEM image of the surface of the transparent conductive film (silver nanowire layer) of the transparent electrode obtained in Example 1. 20 is a photograph showing an SEM image of the transparent conductive film (silver nanowire layer) surface of the transparent electrode obtained in Example 2. FIG. FIG. 21 is a photograph showing an SEM image of the transparent conductive film (silver nanowire layer) surface of the transparent electrode obtained in Comparative Example 2. FIG. 22 is a photograph showing an SEM image of the transparent conductive film (silver nanowire layer) surface of the transparent electrode obtained in Example 3. FIG. 23 is a photograph showing an SEM image of the transparent conductive film (silver nanowire layer) surface of the transparent electrode obtained in Example 4.

(Nanoparticle-supported metal nanowires)
The nanoparticle carrying | support metal nanowire of this invention is a metal nanowire which carry | supported the nanoparticle.
Here, “supporting a nanoparticle” means “the nanoparticle and the metal nanowire are in contact (for example, see FIG. 1)” or “the nanoparticle and the metal nanowire are a linker molecule ( For example, it is connected through FIG. 2A and FIG. 2B).
FIG. 1 is a schematic view for explaining a nanoparticle-supported metal nanowire of the present invention.
In FIG. 1, at least a part of the surface 2 a of the metal nanowire 2 in the nanoparticle-supported metal nanowire 1 is covered with the nanoparticles 3. Thereby, visible light is absorbed by the nanoparticles 3 covered on at least a part of the metal nanowire surface 2a, and irregular reflection of light on the metal nanowire surface 2a is prevented.

The coverage of the nanoparticles in the nanoparticle-supporting metal nanowire can be defined by, for example, the area ratio of the nanoparticles per unit area of the metal nanowire in a micrograph (SEM image).
If the coverage of the nanoparticles is too small, the effect of suppressing external light scattering may be reduced. If the coverage of the nanoparticles is too large, even if the nanoparticles are metal particles, contact Resistance may increase and conductivity may deteriorate.

<Nanoparticles>
There is no restriction | limiting in particular as said nanoparticle, According to the objective, it can select suitably, For example, a metal particle, a resin particle, an inorganic particle, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Among these, particles (for example, metal particles, resin particles composed of a conductive polymer, etc.) composed of a conductive material are particularly used in the second embodiment of the method for producing a transparent conductive film described later (preliminarily metal In the method of supporting nanoparticles on nanowires, this is preferable from the viewpoint of conductivity.

-Metal particles-
There is no restriction | limiting in particular as a metal in the said metal particle, According to the objective, it can select suitably, For example, Mg, Sc, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Examples include Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, Si, Ge, Sn, Pb, La, Nd, and the like. These may be used individually by 1 type and may use 2 or more types together.

-Resin particles-
The resin in the resin particles is not particularly limited and may be appropriately selected depending on the purpose. For example, (i) organic pigments (azo, phthalocyanine, quinacridone, Prussian blue analog, aniline black, perylene (Ii) conductive polymer (polyacetylene (trans-type polyacetylene, cis-type polyacetylene, polydiacetylene, etc.), poly (phenylene) (poly (p-phenylene), poly (m-phenylene), Polythiophene (polythiophene, poly (3-alkylthiophene), poly (3-thiophene-β-ethanesulfonic acid), polyalkylene dioxythiophene and polystyrene sulfonate complex, etc.), polyaniline (polyaniline, Polymethylaniline, polymethoxyaniline, etc.), poly Pyrrole (polypyrrole, poly-3-methylpyrrole, poly-3-octylpyrrole, etc.), poly (phenylene vinylene) (poly (p-phenylene vinylene), etc.), poly (vinylene sulfide), poly (p-phenylene) Sulfide), poly (thienylene vinylene), etc.); and the like. These may be used individually by 1 type and may use 2 or more types together.

-Inorganic particles-
There is no restriction | limiting in particular as an inorganic substance in the said inorganic particle, According to the objective, it can select suitably, For example, Mg, Sc, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, Si, Ge, Sn, Pb, La, Nd, and other metal element oxides (metal oxides); Metal nitride); Carbide of metal element (metal carbide); Carbon; Graphite; Iron oxide; Co-Cr-Fe composite oxide; Co-Mn-Fe composite oxide; Antimony-doped tin oxide; Iron sulfide; Silver sulfide; and the like. These may be used individually by 1 type and may use 2 or more types together.

  The surface of the nanoparticles may be treated with a dispersant. The dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include low molecular compounds such as organic carboxylic acids and organic amines, high molecular compounds such as polyvinyl pyrrolidone, and linker molecules described below. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.

-The color of the surface of the nanoparticles-
The color exhibited by the surface of the nanoparticles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably colored to absorb light in the visible light region, black, blue, dark red, dark green, Is more preferable, and black is particularly preferable because it can absorb more light in the visible light region. When the color of the surface of the nanoparticles is black, the nanoparticle dispersion or dry powder is black.

There is no restriction | limiting in particular as a shape of the said nanoparticle, According to the objective, it can select suitably, For example, spherical shape, ellipsoid shape, needle shape, plate shape, scale shape, tube shape, fiber shape, rod shape (rod) Shape), indefinite shape, and the like. These may be used alone or in combination of two or more.
Here, the spherical shape includes not only a true spherical shape but also a substantially flat or distorted substantially spherical shape. The ellipsoidal shape includes not only a strict ellipsoidal shape but also a slightly flattened or distorted substantially elliptical shape.

There is no restriction | limiting in particular as an average particle diameter of the said nanoparticle, Although it can select suitably according to the objective, 1 nm-100 nm are preferable, and 5 nm-20 nm are more preferable.
When the average particle diameter of the nanoparticles is less than 1 nm, the effect of suppressing external light scattering may be reduced. When the average particle diameter exceeds 100 nm, the total light transmittance of the transparent electrode may be reduced or haze may be increased. ) Or the transparent electrode may exhibit the surface color of the nanoparticles. On the other hand, when the average particle diameter of the nanoparticles is within the more preferable range, it is advantageous in that the effect of suppressing external light scattering is high and the transparency of the transparent electrode can be maintained high.
The average particle size of the nanoparticles is a number average particle size that can be measured with a transmission electron microscope.
“Particle size” means “diameter” when the nanoparticles are spherical, and means “major axis length” when the nanoparticles are other than spherical. The particle size is measured from at least 100 nanoparticles, and the arithmetic average is taken as the average particle size.

<Metal nanowires>
The metal nanowire is made of metal and is a fine wire having a diameter on the order of nm.
In addition, the surface of the metal nanowire may be surface-treated with a linker molecule.

The constituent element of the metal nanowire is not particularly limited as long as it is a metal element, and can be appropriately selected according to the purpose. For example, Ag, Au, Ni, Cu, Pd, Pt, Rh, Ir, Examples include Ru, Os, Fe, Co, Sn, Al, Tl, Zn, Nb, Ti, In, W, Mo, Cr, Fe, V, and Ta. These may be used individually by 1 type and may use 2 or more types together.
Among these, Ag and Cu are preferable in terms of high conductivity.

There is no restriction | limiting in particular as an average short axis diameter of the said metal nanowire, Although it can select suitably according to the objective, More than 1 nm and 500 nm or less are preferable, and 10 nm-100 nm are more preferable.
When the average minor axis diameter of the metal nanowire is 1 nm or less, the conductivity of the metal nanowire deteriorates, and the transparent conductive film containing the metal nanowire may not function as a conductive film. When it is, the total light transmittance and haze (Haze) of the transparent conductive film containing the said metal nanowire may deteriorate. On the other hand, when the average minor axis diameter of the metal nanowire is within the more preferable range, it is advantageous in that the transparent conductive film including the metal nanowire has high conductivity and high transparency.
There is no restriction | limiting in particular as an average major axis length of the said metal nanowire, Although it can select suitably according to the objective, More than 1 micrometer and 1000 micrometers or less are preferable, and 10 micrometers-300 micrometers are more preferable.
When the average major axis length of the metal nanowires is 1 μm or less, the metal nanowires are hardly connected to each other, and the transparent conductive film containing the metal nanowires may not function as a conductive film, and is more than 1000 μm. The total light transmittance and haze of the transparent conductive film containing the metal nanowires may deteriorate, or the dispersibility of the metal nanowires in the dispersion used when forming the transparent conductive film may deteriorate. On the other hand, when the average major axis length of the metal nanowire is within the more preferable range, it is advantageous in that the transparent conductive film including the metal nanowire has high conductivity and high transparency.
The average minor axis diameter and the average major axis length of the metal nanowires are the number average minor axis diameter and the number average major axis length that can be measured with a scanning electron microscope. More specifically, at least 100 metal nanowires are measured, and the projected diameter and projected area of each nanowire are calculated from an electron micrograph using an image analyzer. The projected diameter was the minor axis diameter. Further, the major axis length was calculated based on the following formula.
Long axis length = projected area / projected diameter The average minor axis diameter was an arithmetic average value of minor axis diameters. The average major axis length was the arithmetic average value of the major axis length.
Further, the metal nanowire may have a wire shape in which metal nanoparticles are connected in a bead shape. In this case, the length is not limited.

The weight per unit area of the metal nanowires is not particularly limited and may be appropriately selected depending on the intended ^purpose, but is preferably ^{0.001g / m 2 ~1.000g / m 2} , 0.003g / m 2 ~ 0.3 g / m ² is more preferable.
When the basis weight of the metal nanowire is less than 0.001 g / m ² , the metal nanowire is not sufficiently present in the metal nanowire layer, and the conductivity of the transparent conductive film may be deteriorated. When the amount is more than 1.000 g / m ² , the total light transmittance and haze of the transparent conductive film may be deteriorated. On the other hand, when the basis weight of the metal nanowire is within the more preferable range, it is advantageous in that the conductivity of the transparent conductive film is high and the transparency is high.

<Linker molecule>
The linker molecule has at least a functional group X that adsorbs to the metal nanowire and a functional group Y that adsorbs to the nanoparticle, and an organic small molecule (for example, see FIG. 2A) and an organic polymer (for example, FIG. 2B). Reference).
FIG. 2A is a schematic diagram for explaining a linker (small organic molecule) that connects metal nanowires and nanoparticles.
In FIG. 2A, the linker (small organic molecule) 10 has a functional group X that adsorbs to the metal nanowire 2 at one end and a functional group Y that adsorbs to the nanoparticle 3 at the other end.
FIG. 2B is a schematic diagram for explaining a linker (organic polymer) that connects metal nanowires and nanoparticles.
In FIG. 2B, the linker (organic polymer) 20 has a plurality of functional groups X that adsorb to the metal nanowires 2 in the polymer chain, and a plurality of functional groups Y that adsorb to the nanoparticles 3 in the polymer chain. .
The functional group X or the functional group Y is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a sulfo group (including a sulfonate salt), a sulfonyl group, a sulfonamide group, and a carboxylic acid group ( (Including carboxylates), amino groups, amide groups, phosphate groups (including phosphates and phosphate esters), phosphino groups, silanol groups, epoxy groups, isocyanate groups, cyano groups, vinyl groups, thiol groups, carbinol groups , Hydroxyl groups, and the like. These may be used individually by 1 type and may use 2 or more types together. The functional group X and the functional group Y may be the same or different from each other.
The organic low molecule is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 1,4-butanedithiol, 2,3-butanedithiol, 1,6-hexanedithiol, 1,2- Benzenedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,3,5-benzenetrithiol, (3-mercaptopropyl) trimethoxysilane, 4-mercapto-1-butanol, 3-[(2 -Mercapto-1-methylpropyl) thio] -2-butanol, 6-hydroxy-1-hexanethiol, 6-amino-1-hexanethiol hydrochloride, 7-carboxy-1-heptanethiol, 7-amido-1- Heptanethiol, 8-amino-1-octanethiol hydrochloride, 10-carboxy-1-decanethiol, 10-amide 1-decane thiol, 11-amino-1-undecanethiol hydrochloride, 11-hydroxy-1-undecanethiol, 16-hydroxy-1-hexadecanethiol, 16-amino-1-hexadecanethiol hydrochloride, and the like. These may be used individually by 1 type and may use 2 or more types together.
The organic polymer is not particularly limited and may be appropriately selected depending on the intended purpose.For example, polyvinylpyrrolidone, polyethyleneimine, chitosan salt, polyallylamine, aminoethylated acrylic polymer, polyamideamine, polyetheramine, Etc. These may be used individually by 1 type and may use 2 or more types together.

<Method for producing nanoparticle-supported metal nanowire>
The nanoparticle-supporting metal nanowire can be obtained by mixing a metal nanowire dispersion solution and a nanoparticle dispersion solution. More specifically, the metal nanowire dispersion solution and the nanoparticle dispersion solution are mixed, and then the nanoparticles are supported on the metal nanowire while stirring at room temperature to 100 ° C. for 1 minute to 48 hours. In addition, after performing the nanoparticle support treatment, an operation of removing unsupported nanoparticles may be performed using centrifugation, filtering, or the like.

-Metal nanowire dispersion solution-
The metal nanowire dispersion solution contains at least metal nanowires and a solvent, and contains other components such as a linker molecule and a dispersant as required.
There is no restriction | limiting in particular in the said solvent, The material which can disperse | distribute metal nanowire to predetermined concentration can be selected suitably, For example, what is mentioned later by description of the dispersion liquid of this invention is mentioned.
The metal nanowires and the linker molecules are as described above, and the dispersant is the same as that described later in the description of the dispersion of the present invention.

-Nanoparticle dispersion solution-
The nanoparticle dispersion solution contains at least nanoparticles and a solvent, and if necessary, contains other components such as a linker molecule and a dispersant.
The solvent is not particularly limited, and a material that can disperse the nanoparticles at a predetermined concentration and is compatible with the solvent of the metal nanowire dispersion solution can be appropriately selected. For example, water, acetonitrile, 3-methoxy Propionitrile, 3,3-dimethoxypropionitrile ethoxypropionitrile, 3-ethoxypropionitrile, 3,3'-oxydipropionitrile, 3-aminopropionitrile, propionitrile, propyl cyanoacetate, isothiocyan 3-methoxypropyl acid, 3-phenoxypropionitrile, p-anisidine 3- (phenylmethoxy) propanenitrile, methanol, ethanol, propanol, isopropyl alcohol, n-butanol, 2-butanol, isobutanol, t-butanol, ethylene Glycol, triethyle Glycol, 1-methoxy-ethanol, 1,1-dimethyl-2-methoxyethanol, 3-methoxy-1-propanol, dimethyl sulfoxide, benzene, toluene, o-xylene, m-xylene, p-xylene, chlorobenzene, di- Examples include chlorobenzene, butyl acetate, ethyl acetate, hexane, cyclohexane, cyclohexanone, ethyl methyl ketone, acetone, dimethylformamide, and the like. These may be used individually by 1 type and may use 2 or more types together.
The nanoparticles and the linker molecule are as described above, and the dispersant is the same as that described later in the description of the dispersion of the present invention.
There is no restriction | limiting in particular as a density | concentration of the nanoparticle in the said nanoparticle dispersion solution, Although it can select suitably according to the objective, 0.01 mass% from a viewpoint of improving the loading speed of the nanoparticle with respect to metal nanowire. The above is preferable.

(Dispersion)
The dispersion of the present invention contains at least the nanoparticle-supported metal nanowire of the present invention, and further contains a binder, a solvent, a dispersant, other additives, and the like as necessary. Here, the nanoparticle carrying | support metal nanowire of this invention is as having mentioned above.
In addition, instead of using the above-mentioned “dispersion containing the nanoparticle-supported metal nanowire of the present invention” as a dispersion used to produce the transparent conductive film of the present invention described later, “metal nanowire and binder” And a dispersion containing a solvent and a “nanoparticle dispersion” may be used in combination. Here, the metal nanowires and nanoparticles are as described above.
Furthermore, instead of using the “dispersion containing the nanoparticle-supported metal nanowire of the present invention” as the dispersion used to produce the transparent conductive film of the present invention described later, “metal nanowire and nanoparticle” A dispersion containing a binder and a solvent ”may be used.

  The dispersion method of the dispersion is not particularly limited and may be appropriately selected depending on the purpose. For example, stirring, ultrasonic dispersion, bead dispersion, kneading, homogenizer treatment, pressure dispersion treatment, and the like are preferable. It is mentioned in.

There is no restriction | limiting in particular as a compounding quantity of the metal nanowire in the nanoparticle carrying | support metal nanowire in the said dispersion liquid, Although it can select suitably according to the objective, When the mass of the said dispersion liquid is 100 mass parts 0.01 parts by mass to 10.00 parts by mass is preferable.
When the compounding amount of the metal nanowires in the nanoparticle-supporting metal nanowires is less than 0.01 parts by mass, the basis weight (0.001 to 1.. 000 [g / m ² ]) may not be obtained, and if it exceeds 10.00 parts by mass, the dispersibility of the metal nanowires may be deteriorated.

<Binder>
The binder disperses nanoparticle-supported metal nanowires and / or metal nanowires.
The binder is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include known transparent, natural polymer resins and synthetic polymer resins, and may be thermoplastic resins. It may also be a heat (light) curable resin that is cured by heat, light, electron beam, or radiation. These may be used individually by 1 type and may use 2 or more types together.
The thermoplastic resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polymethyl methacrylate, nitrocellulose, chlorinated polyethylene, chlorine Polypropylene, vinylidene fluoride, ethylcellulose, hydroxypropylmethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, and the like.
The thermosetting (photo) curable resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include silicon resins such as melamine acrylate, urethane acrylate, isocyanate, epoxy resin, polyimide resin, and acrylic-modified silicate. And a polymer in which a photosensitive group such as an azide group or a diazirine group is introduced into at least one of a main chain and a side chain.

<Solvent>
The solvent is not particularly limited as long as the nanoparticle-supported metal nanowires and / or metal nanowires are dispersed, and can be appropriately selected according to the purpose. For example, water; methanol, ethanol , N-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, tert-butanol and other alcohols; cyclohexanone, cyclopentanone and other anones; N, N-dimethylformamide (DMF) and other amides; And sulfides such as dimethyl sulfoxide (DMSO). These may be used individually by 1 type and may use 2 or more types together.

In order to suppress drying unevenness and cracks in the dispersion film formed using the dispersion, a high boiling point solvent may be further added to the dispersion. Thereby, the evaporation rate of the solvent from the dispersion can be controlled.
The high boiling point solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, butyl cellosolve, diacetone alcohol, butyl triglycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl Ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol isopropyl A Le, dipropylene glycol isopropyl ether, tripropylene glycol isopropyl ether, methyl glycol, and the like. These may be used individually by 1 type and may use 2 or more types together.

<Dispersant>
The dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polyvinyl pyrrolidone (PVP); amino group-containing compounds such as polyethyleneimine; sulfo groups (including sulfonates) and sulfonyl groups. , Sulfonamide group, carboxylic acid group (including carboxylate), amide group, phosphate group (including phosphate and phosphate ester), phosphino group, silanol group, epoxy group, isocyanate group, cyano group, vinyl group, A compound having a functional group such as a thiol group or a carbinol group, which can be adsorbed to a metal; These may be used alone or in combination of two or more.
You may make the said dispersing agent adsorb | suck to the surface of the said nanoparticle carrying | support metal nanowire or the said metal nanowire. Thereby, the dispersibility of the said nanoparticle carrying | support metal nanowire or the said metal nanowire can be improved.

  Moreover, when adding the said dispersing agent with respect to the said dispersion liquid, it is preferable to make it the addition amount of the grade which the electroconductivity of the transparent conductive film finally obtained does not deteriorate. Thereby, the said dispersing agent can be made to adsorb | suck to the nanoparticle carrying | support metal nanowire or metal nanowire by the quantity which is the extent which the electroconductivity of a transparent conductive film does not deteriorate.

<Other additives>
There is no restriction | limiting in particular as said other additive, According to the objective, it can select suitably, For example, a thickener, surfactant, a linker molecule, etc. are mentioned. The linker molecule may have a function of a dispersant.

(Transparent conductive film)
The transparent conductive film of the present invention includes at least (i) metal nanowires, and (ii) nanoparticles supported on the metal nanowires and / or nanoparticles unevenly distributed in the vicinity of the metal nanowires. And further contains other components as necessary.
That is, the nanoparticles in the transparent conductive film are in contact with the metal nanowires (for example, see FIG. 1), or are connected to the metal nanowires through linker molecules (for example, FIG. 2A and FIG. 2B), it may be unevenly distributed in the vicinity of the metal nanowire (for example, see FIG. 3).
FIG. 3 is a schematic diagram for explaining that nanoparticles are unevenly distributed in the vicinity of metal nanowires in the transparent conductive film of the present invention.
In FIG. 3, the transparent conductive film 30 formed on the substrate 40 includes a metal nanowire 2 and a binder layer 31 that includes therein nanoparticles 3 that are unevenly distributed in the vicinity of the metal nanowire 2.
Here, the “vicinity” means a region existing at a distance within 5 times the length of the diameter of the metal nanowire from the surface of the metal nanowire.

  As the transparent electrode having the transparent conductive film of the present invention, (i) metal nanowires, (ii) nanoparticles supported on the metal nanowires, and / or nanoparticles unevenly distributed in the vicinity of the metal nanowires, As long as it has a transparent conductive film containing, there is no particular limitation, and it can be appropriately selected according to the purpose. For example, as shown in FIG. 4, the exposed portion of the metal nanowire 2 from the binder layer 31 (Ii) Nanoparticles 3 may be supported on the surface of the metal nanowire 2 as shown in FIG. 5. 3 is supported (the nanoparticles 3 may be present in the binder layer 31), (iii) As shown in FIG. 6, the overcoat layer 50 is formed on the binder layer 31, iv As shown in FIG. 7, the anchor layer 60 is formed between the binder layer 31 and the base material 40. (v) As shown in FIG. 8, the metal nanowire 2 carrying the nanoparticles 3 is included. The binder layer 31 is formed on both surfaces of the substrate 40, (vi) the above (i) to (v) are appropriately combined, and the like.

-Base material-
There is no restriction | limiting in particular as said base material, Although it can select suitably according to the objective, The transparent base material comprised with the material which has transparency with respect to visible light, such as an inorganic material and a plastic material, is preferable. The transparent substrate has a film thickness required for a transparent electrode having a transparent conductive film. For example, a film (sheet) thinned to such an extent that flexible flexibility can be realized, or an appropriate amount It is assumed that the substrate has a film thickness sufficient to realize flexibility and rigidity.
There is no restriction | limiting in particular as said inorganic material, According to the objective, it can select suitably, For example, quartz, sapphire, glass, etc. are mentioned.
There is no restriction | limiting in particular as said plastic material, According to the objective, it can select suitably, For example, a triacetyl cellulose (TAC), polyester (TPEE), a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), a polyimide (PI), polyamide (PA), aramid, polyethylene (PE), polyacrylate, polyether sulfone, polysulfone, polypropylene (PP), diacetyl cellulose, polyvinyl chloride, acrylic resin (PMMA), polycarbonate (PC), epoxy Known polymer materials such as resin, urea resin, urethane resin, melamine resin, and cycloolefin polymer (COP) can be used. When a transparent base material is configured using such a plastic material, the film thickness of the transparent base material is preferably 5 μm to 500 μm from the viewpoint of productivity, but is not particularly limited to this range.

-Overcoat layer-
It is important that the overcoat layer has a light-transmitting property with respect to visible light, and is composed of a polyacrylic resin, a polyamide resin, a polyester resin, or a cellulose resin, or In addition, it is composed of metal alkoxide hydrolysis, dehydration condensate and the like. Moreover, such an overcoat layer shall be comprised by the film thickness by which the light transmittance with respect to visible light is not inhibited. The overcoat layer may have at least one function selected from a functional group consisting of a hard coat function, an antiglare function, an antireflection function, an anti-Newton ring function, an antiblocking function, and the like.

-Anchor layer-
The anchor layer is not particularly limited and may be appropriately selected depending on the purpose as long as the base material and the binder layer can be bonded more firmly.

(Method for producing transparent conductive film)
<First Embodiment>
Hereinafter, 1st Embodiment of the manufacturing method of the transparent conductive film of this invention is described.
The method for producing a transparent conductive film of the present invention includes at least a dispersion film forming process, a curing process, and a surface treatment process, and further appropriately selected as necessary, a calendar process, a rinse drying process, and an overcoat layer formation. A process, a treatment process with a linker molecule, a pattern electrode formation process, and other processes.
1st Embodiment of the manufacturing method of the transparent conductive film of this invention is performed in order of a dispersion film formation process, a hardening process, a calendar process, a surface treatment process, and a rinse drying process, for example.

-Dispersion film formation process-
The dispersion film forming step is a step of forming a dispersion film on a substrate using a dispersion liquid containing metal nanowires, a binder, and a solvent.
The metal nanowire, the binder, and the solvent are all as described above in the description of the dispersion of the present invention.
The method for forming the dispersion film is not particularly limited and may be appropriately selected depending on the intended purpose. However, a wet film formation method is preferable in terms of physical properties, convenience, production cost, and the like.
There is no restriction | limiting in particular as said wet film-forming method, According to the objective, it can select suitably, For example, well-known methods, such as the apply | coating method, the spray method, and the printing method, are mentioned.
The coating method is not particularly limited and can be appropriately selected according to the purpose. For example, the micro gravure coating method, the wire bar coating method, the direct gravure coating method, the die coating method, the dip method, and the spray coating. Method, reverse roll coating method, curtain coating method, comma coating method, knife coating method, spin coating method, and the like.
There is no restriction | limiting in particular as said spray method, According to the objective, it can select suitably.
The printing method is not particularly limited and can be appropriately selected depending on the purpose. For example, letterpress printing, offset printing, gravure printing, intaglio printing, rubber printing, screen printing, ink jet printing, and the like. Is mentioned.

-Curing process-
The said hardening process is a process of hardening the dispersion film formed on the said base material, and obtaining hardened | cured material (binder layer 31 containing the metal nanowire 2 in FIG. 9).
In the curing step, first, the solvent in the dispersion film formed on the substrate is dried and removed. The removal of the solvent by drying may be either natural drying or heat drying. After drying, the uncured binder is cured, and the metal nanowires are dispersed in the cured binder. Here, the said hardening process can be performed by a heating and / or active energy ray irradiation.

-Surface treatment process-
In the surface treatment step, (i) as shown in FIG. 10, a cured product 70 obtained by curing the dispersion film is immersed in a nanoparticle dispersion solution 80 containing nanoparticles 3 and a solvent, or (Ii) A step of applying or printing a nanoparticle dispersion solution containing nanoparticles and a solvent on a cured product obtained by curing the dispersion film.
As a result, as shown in FIG. 11, the metal nanowires 2 dispersed in the cured binder layer 31 are loaded with the nanoparticles 3 in the nanoparticle dispersion solution to form a layer containing the nanoparticle-supported metal nanowires. To do. In such a supporting treatment, the nanoparticles 3 in the nanoparticle dispersion solution and the metal material constituting the metal nanowires 2 are chemically adsorbed (covalent bonds, coordinate bonds, Ionic bond or hydrogen bond) or physical adsorption.

  Specific examples of such a supporting treatment include (i) an immersion method in which a dispersion film in which metal nanowires 2 are dispersed is immersed in a nanoparticle dispersion solution, and (ii) a liquid film of the nanoparticle dispersion solution on the dispersion film. Examples thereof include a coating method or a printing method.

  In the case of applying the immersion method, a nanoparticle dispersion solution is prepared so that the dispersion film is sufficiently immersed, and the dispersion film is immersed in the nanoparticle dispersion solution for 0.1 seconds to 48 hours. During this time, by carrying out at least one of heating and sonication, the loading speed of the nanoparticles on the metal nanowire can be increased. After the immersion, if necessary, the dispersion film is washed with a good solvent for nanoparticles to remove unsupported nanoparticles remaining in the dispersion film.

When applying the coating method, for example, micro gravure coating method, wire bar coating method, direct gravure coating method, die coating method, dip method, spray coating method, reverse roll coating method, curtain coating method, comma coating method, knife coating An appropriate method is selected from a method, a spin coating method, and the like, and a liquid film of the nanoparticle dispersion solution is formed on the dispersion film.
When applying the printing method, for example, an appropriate method is selected from a relief printing method, an offset printing method, a gravure printing method, an intaglio printing method, a rubber plate printing method, an ink jet method, a screen printing method, etc. A liquid film of the nanoparticle dispersion solution is formed.

  When the coating method or the printing method is applied, metal nanowires are obtained by performing at least one of heating and ultrasonic treatment in a state where a liquid film of a predetermined amount of the nanoparticle dispersion solution is formed on the dispersion film. It is possible to increase the loading speed of nanoparticles with respect to. In addition, after a certain time has elapsed since the formation of the liquid film of the nanoparticle dispersion solution, if necessary, the dispersion film is washed with a good solvent for the nanoparticles to remove unsupported nanoparticles remaining in the dispersion film. The process to do is performed.

  Note that the formation of a liquid film of a certain amount of the nanoparticle dispersion solution need not be achieved by forming a single liquid film, but can be achieved by repeating the liquid film forming process and the cleaning process described above a plurality of times. May be.

  Moreover, you may surface-treat the hardened | cured material obtained by hardening the said dispersion film with a linker molecule before performing the said surface treatment process. The surface treatment may be performed, for example, by preparing a solution in which linker molecules are dissolved, and (i) immersing the cured product in the prepared linker molecule solution, or (ii) adding the prepared linker molecule solution to the cured product. It is performed by applying or printing.

-Calendar process-
The calendar treatment is a step performed between (i) the curing step and the surface treatment step, (ii) after the rinse drying step, or (iii) after the overcoat layer forming step. In this process, the surface smoothness is improved or the surface is glossed.
By performing such a calendar process, the sheet resistance value of the obtained transparent conductive film can be lowered.

-Rinse drying process-
The rinse drying step is a step of rinsing the surface-treated cured product with a predetermined solvent after the surface treatment step, followed by a drying treatment. Thereby, manufacture of the transparent conductive film containing the nanoparticle carrying | support metal nanowire formed on the base material is completed. The drying process may be either natural drying or heat drying.

-Overcoat layer formation process-
The overcoat layer forming step is a step of forming an overcoat layer on the cured product after the cured product of the dispersion is formed. The overcoat layer forming step may be performed after rinsing and drying.
The overcoat layer can be formed, for example, by applying an overcoat layer forming coating solution containing a predetermined material on the cured product and curing it.

-Processing with linker molecules-
The treatment step with the linker molecule is a step in which the cured product of the dispersion film in which the metal nanowires are dispersed is surface-treated with the linker molecule before the surface treatment step.
In the treatment step with the linker molecule, a solution in which the linker molecule is dissolved is prepared, and the cured product of the dispersion film is immersed in the prepared linker molecule solution, or the prepared linker molecule solution is added to the dispersion film. Apply or print on the cured product.

-Pattern electrode formation process-
The pattern electrode formation step is a step of forming a pattern electrode by applying a known photolithography process after the rinse drying step. Thereby, the transparent conductive film of this invention can be applied to the sensor electrode for electrostatic capacitance touch panels. In addition, when the hardening process in the said hardening process includes active energy ray irradiation, you may form a pattern electrode by making the said hardening process into mask exposure / development.

  As a transparent conductive film obtained by 1st Embodiment of the manufacturing method of the transparent conductive film of this invention, for example, (i) As shown in FIG. 12, only a part exposed from the binder layer 31 of metal nanowire 2 is nano. Particles 3 are supported (the nanoparticles 3 may be part of the surface of the binder layer 31), (ii) as shown in FIG. 13, the overcoat layer 50 on the binder layer 31 in FIG. Are formed.

  According to the first embodiment of the method for producing a transparent conductive film of the present invention, metal nanowires can be brought into contact with each other more reliably, so that the resin particles other than metal particles or inorganic can be used as the nanoparticles. Particles can be used.

Second Embodiment
Hereinafter, a second embodiment of the method for producing a transparent conductive film of the present invention will be described. Here, the part which overlaps with description of 1st Embodiment of the manufacturing method of the transparent conductive film of this invention is abbreviate | omitted.
The method for producing a transparent conductive film of the present invention includes at least a dispersion film forming process and a curing process, and further appropriately selected as necessary, a calendar process, an overcoat layer forming process, a pattern electrode forming process, and the like. These steps are included.
2nd Embodiment of the manufacturing method of the transparent conductive film of this invention is performed in order of a dispersion film formation process, a hardening process, and a calendar process, for example.

-Dispersion film formation process-
The dispersion film forming step includes (i) a dispersion containing nanoparticle-supported metal nanowires, a binder, and a solvent, or (ii) a dispersion containing nanoparticles, metal nanowires, a binder, and a solvent. This is a step of forming a dispersion film on a substrate using a liquid.
The nanoparticle-supporting metal nanowire, the nanoparticle, the metal nanowire, the binder, and the solvent are all as described above in the description of the dispersion of the present invention.

-Curing process-
The said hardening process is a process of hardening the dispersion film formed on the said base material, and obtaining hardened | cured material.

-Calendar process-
The calendering step is a step performed after (i) the curing step or (ii) after the overcoat layer forming step.

-Overcoat layer formation process-
The overcoat layer forming step is a step of forming an overcoat layer on the cured product after the cured product of the dispersion film is formed.

-Pattern electrode formation process-
The pattern electrode forming step is a step of forming a pattern electrode by applying a known photolithography process after forming a transparent conductive film on a substrate. Thereby, the transparent conductive film of this invention can be applied to the sensor electrode for electrostatic capacitance touch panels. In addition, when the hardening process in the said hardening process includes active energy ray irradiation, you may form a pattern electrode by making the said hardening process into mask exposure / development.

  As a transparent conductive film obtained by 2nd Embodiment of the manufacturing method of the transparent conductive film of this invention, (i) As shown in FIG. 14, the nanoparticle 3 is carry | supported on the surface of the metal nanowire 2, for example. (The nanoparticle 3 may be partly in the binder layer 31), (ii) As shown in FIG. 15, the overcoat layer 50 is formed on the binder layer 31 in FIG. Is mentioned.

(Touch panel)
The touch panel of the present invention includes at least a transparent electrode having the transparent conductive film of the present invention, and further includes other known members (see, for example, Japanese Patent No. 4862969) as necessary.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not restrict | limited to the following Example.

(Comparative Example 1)
<Preparation of silver nanowire ink (dispersion)>
A silver nanowire ink was prepared with the following composition.
(1) Metal nanowire: Silver nanowire (manufactured by Seashell Technology, AgNW-25, average diameter 25 nm, average length 23 μm): compounding amount 0.045 parts by mass (2) Dispersant: polyvinylpyrrolidone (Wako Pure Chemical Industries, Ltd.) Co., Ltd., K30): Compounding amount 0.003 parts by mass (3) Binder: Hydroxypropyl methylcellulose (manufactured by Aldrich, viscosity of 2% aqueous solution at 20 ° C., 80 cP to 120 cP (document value)): compounding amount 0.09 mass Parts (4) cross-linking agent: organotitanium compound (manufactured by Matsumoto Fine Chemical Co., Ltd., ORGATICS TC-400): compounding amount 0.009 parts by mass (5) solvent: (i) water: compounding amount 88.962 parts by mass, ( ii) 1-propanol: compounding amount 10 parts by mass, (iii) isopropanol: compounding amount 0.891 parts by mass Preparation of silver nanowires transparent electrode (silver nanowire transparent conductive film)>
A silver nanowire transparent electrode was prepared by the following procedure.
First, the produced silver nanowire ink (dispersion) was applied onto a transparent substrate (PET: U34, film thickness 125 μm) with a coil bar (counter 10) to form a silver nanowire dispersion film. . Here, the basis weight of the silver nanowire was set to about 0.01 g / m ² .
Next, in the atmosphere, hot air was applied to the coated surface with a dryer to remove the solvent in the silver nanowire-dispersed film by drying.
Thereafter, a heat curing treatment at 120 ° C. for 5 minutes was performed in an oven.
Thereafter, calendar processing (nip width 1 mm, load 4 kN, speed 1 m / min) was performed using a calendar processing apparatus (see FIG. 16) including a cylindrical press roll and a back roll.
The sheet resistance is measured on the surface of the transparent conductive film (silver nanowire layer) by contacting a measurement probe of a manual nondestructive resistance measuring instrument (manufactured by Napson Corporation, EC-80P) to the surface of the silver nanowire dispersion film. Were measured at three locations, and the average value was taken as the sheet resistance. The sheet resistance was 100Ω / □.

Example 1
<Preparation of palladium nanoparticle dispersion solution>
A palladium nanoparticle dispersion solution was prepared with the following composition.
(1) Nanoparticles: Palladium nanoparticles (manufactured by Tokuroku Honten Co., Ltd., average particle size 19 nm, black): blending amount 0.1 parts by mass (2) solvent: water: blending amount 99.9 parts by mass <silver nanowire transparent Production of electrode>
The silver nanowire transparent electrode prepared in the same manner as in Comparative Example 1 was immersed in the prepared palladium nanoparticle dispersion solution for 12 hours at room temperature, and the palladium nanoparticles were supported on the silver nanowire surface in the silver nanowire transparent electrode. did. The transparent electrode was taken out of the palladium nanoparticle dispersion solution, rinsed with ethanol, and dried by air blow to obtain the silver nanowire transparent electrode of Example 1.

(Example 2)
In Example 1, instead of using the palladium nanoparticle dispersion solution, the silver nanowire transparent electrode was immersed in the platinum nanoparticle dispersion solution prepared by the following formulation, and the platinum nanoparticle was supported on the silver nanowire surface. A transparent electrode was produced in the same manner as Example 1 except for the above.
<Preparation of platinum nanoparticle dispersion solution>
A platinum nanoparticle dispersion solution was prepared with the following composition.
(1) Nanoparticles: Platinum nanoparticles (Tokuriku head office, average particle size 10 nm, black): 0.1 parts by mass of compound (2) Solvent: Water: 99.9 parts by mass of compound

(Comparative Example 2)
<Preparation of silver nanowire ink (dispersion)>
A silver nanowire ink was prepared with the following composition.
(1) Metal nanowire: Silver nanowire (manufactured by Seashell Technology, AgNW-25, average diameter 25 nm, average length 23 μm): blending amount 0.065 parts by mass (2) Dispersant: polyvinylpyrrolidone (Wako Pure Chemical Industries, Ltd.) Co., Ltd., K30): 0.004 parts by mass (3) Binder: water-soluble photosensitive resin (manufactured by Toyo Gosei Co., Ltd., BIOSURFINE-AWP): 0.13 parts by mass (4) Solvent: ( i) Water: blending amount 89.801 parts by mass, (ii) 1-propanol: blending amount 10 parts by mass <Preparation of silver nanowire transparent electrode>
A silver nanowire transparent electrode was prepared by the following procedure.
First, the produced silver nanowire ink (dispersion) was applied onto a transparent substrate (PET: U34, film thickness 125 μm) with a coil bar (count 11) to form a silver nanowire dispersion film. . Here, the basis weight of the silver nanowire was set to about 0.016 g / m ² .
Next, in the atmosphere, hot air was applied to the coated surface with a dryer to remove the solvent in the silver nanowire-dispersed film by drying.
Thereafter, using a metal halide lamp, the binder was cured by irradiating ultraviolet rays with an integrated light amount of 200 mJ / cm ² from the transparent conductive film (silver nanowire layer) side in the atmosphere.
Thereafter, calendar processing (nip width 1 mm, load 4 kN, speed 1 m / min) was performed using a calendar processing apparatus (see FIG. 16) including a cylindrical press roll and a back roll.
The sheet resistance is measured on the surface of the transparent conductive film (silver nanowire layer) by contacting a measurement probe of a manual nondestructive resistance measuring instrument (manufactured by Napson Corporation, EC-80P) to the surface of the silver nanowire dispersion film. Were measured at three locations, and the average value was taken as the sheet resistance. The sheet resistance was 100Ω / □.
In addition, even if it performed calendar processing before ultraviolet curing, it was the same result (the Example 3 and 4 mentioned later are also the same).

Example 3
<Preparation of platinum nanoparticle dispersion solution>
A platinum nanoparticle dispersion solution was prepared with the following composition.
(1) Nanoparticles: Platinum nanoparticles (manufactured by Tokuriki Honten, average particle size 10 nm, black): blending amount 0.1 parts by mass (2) solvent: water: (i) blending amount 54.9 parts by mass, ( ii) Ethanol: 45 mass parts <production of silver nanowire transparent electrode>
The silver nanowire transparent electrode prepared in the same manner as in Comparative Example 2 was immersed in the prepared platinum nanoparticle dispersion solution for 12 hours at room temperature, and the platinum nanoparticles were supported on the silver nanowire surface in the silver nanowire transparent electrode. did. The transparent electrode was taken out of the platinum nanoparticle dispersion solution, rinsed with ethanol, and dried by air blow to obtain a silver nanowire transparent electrode of Example 3.

Example 4
In Example 3, instead of using a platinum nanoparticle dispersion solution containing ethanol as a solvent, a silver nanowire transparent electrode was immersed in a platinum nanoparticle dispersion solution prepared by the following composition, and the platinum nanoparticle was placed on the surface of the silver nanowire. A transparent electrode was produced in the same manner as in Example 3 except that the electrode was supported on.
<Preparation of platinum nanoparticle dispersion solution>
A platinum nanoparticle dispersion solution was prepared with the following composition.
(1) Nanoparticles: Platinum nanoparticles (Tokuriku head office, average particle size 10 nm, black): 0.1 parts by mass of compound (2) Solvent: Water: 99.9 parts by mass of compound

(Comparative Example 3)
The nanoparticles are randomly (uniformly) dispersed in the binder layer as described in JP 2011-29038 A, except that the composition of the silver nanowire ink is as follows. A transparent electrode was produced.
(1) Metal nanowire: Silver nanowire (manufactured by Seashell Technology, AgNW-25, average diameter 25 nm, average length 23 μm): compounding amount 0.045 parts by mass (2) Nanoparticle: palladium nanoparticle (Tokuriki Co., Ltd.) (Main store, average particle size 19 nm, black): 0.02 parts by mass of blending amount (3) Binder: hydroxypropylmethylcellulose (manufactured by Aldrich, viscosity of 2% aqueous solution at 20 ° C., 80 cP to 120 cP (reference value)): blending amount 0.09 parts by mass (4) Crosslinking agent: Organic titanium compound (manufactured by Matsumoto Fine Chemical Co., Ltd., ORGATICS TC-400): Compounding amount 0.009 parts by mass (5) Solvent: (i) Water: Compounding amount 88.945 Parts by weight, (ii) 1-propanol: 10 parts by weight, (iii) isopropanol: 0.8 1 part by weight

(Comparative Example 4)
In Example 1, instead of using a silver nanowire transparent electrode, a carbon nanotube transparent electrode prepared using a SWCNT aqueous dispersion manufactured by KH Chemicals was used. Further, gold nanoparticles (manufactured by Aldrich, average particle size 10 nm, dark red) were used as the nanoparticles instead of palladium nanoparticles. Other than that was carried out similarly to Example 1, and produced the transparent electrode in which the nanotube which the metal nanoparticle couple | bonded as described in Unexamined-Japanese-Patent No. 2011-527809 was contained in the binder layer.
The carbon nanotube electrode itself did not diffusely reflect external light, and the reflection L value was low (reflection L = 7 or less). For this reason, even if gold nanoparticles are supported on carbon nanotubes, there was no effect of reducing the reflection L value. Further, an electrode pattern as shown in FIG. 17 is prepared by a dry etching method, and the electrode pattern side is a glass plate (Matsunami Glass Industry Co., Ltd.) via a transparent double-sided adhesive sheet (manufactured by Nitto Denko Corporation, trade name: LUCIACS CS9621T). Manufactured, MICRO SLIDE GLASS S9213). As a result of observing the electrode pattern visually by projecting a fluorescent lamp on the glass surface, the electrode portion was visually recognized as black regardless of whether or not the gold nanoparticle was supported, and the electrode pattern was easily visible.

(Comparative Example 5)
In Example 1, instead of immersing a silver nanowire transparent electrode prepared in the same manner as in Comparative Example 1 in a palladium nanoparticle dispersion solution at room temperature for 12 hours, a silver nanowire transparent electrode prepared in the same manner as in Comparative Example 1 was used. A colored compound instead of nanoparticles as described in JP 2012-190780 A, similar to Example 1 except that it was immersed in a colored compound solution of the following composition at 80 ° C. for 30 minutes. Produced a transparent electrode supported by metal nanowires.
(1) Colored compound: Okamoto Dye Store Co., Ltd.-made Lany Black BG E / C and Tokyo Chemical Industry Co., Ltd. 2-aminoethanethiol reacted beforehand: Compounding amount 0.2 mass part (2) Solvent: Ethanol : Blending amount 99.8 parts by mass

(Evaluation)
About the transparent electrode produced in the above Examples 1-4 and Comparative Examples 1-5, A) Evaluation of reflection L value, B) Evaluation of black float, C) Evaluation of electrode pattern non-visibility, D) SEM observation evaluated. Each evaluation was performed as follows.

<A) Evaluation of reflection L value>
About the obtained transparent electrode, a black vinyl tape (VT-50 by Nichiban Co., Ltd.) is bonded to the base material surface opposite to the transparent conductive film (silver nanowire layer) side, and the transparent conductive film (silver nano). From the (wire layer) side, according to JIS Z8722, it evaluated by the color i5 by X-Rite. Measurement was performed at three arbitrary locations, and the average value was taken as the reflection L value.

<B) Evaluation of black float>
For the transparent electrodes obtained in Examples 1 to 4 and Comparative Example 5, a portion (untreated portion) that was not subjected to the supporting treatment was formed adjacent to the portion (treated portion) that was subjected to the nanoparticle supporting treatment. A transparent conductive film with a black vinyl tape (VT-50 manufactured by Nichiban Co., Ltd.) pasted on the surface of the substrate opposite to the transparent conductive film (silver nanowire layer) side where the treated part and the untreated part are formed. Visual observation was made from the (silver nanowire layer) side, and the occurrence of black float was evaluated according to the following evaluation criteria.
-Evaluation criteria-
○: The boundary between the processing part and the unprocessed part can be immediately determined, and the processing part is reduced in black floating. Δ: The boundary between the processing part and the non-processing part can be confirmed by the angle. The processing part is reduced in black floating. The boundary of the processing unit is not known, and the processing unit is black. Comparative Example 1 is equivalent to the untreated parts of Examples 1, 2 and Comparative Example 5, and Comparative Example 2 is untreated of Examples 3 and 4. It is equivalent to the part. That is, the three-stage evaluation for Examples 1 and 2 and Comparative Example 5 is an evaluation based on Comparative Example 1, and the three-stage evaluation for Examples 3 and 4 is an evaluation based on Comparative Example 2. is there.

<C) Evaluation of electrode pattern non-visibility>
After forming a resist layer on the transparent conductive film (silver nanowire layer) of the obtained transparent electrode, the resist layer was exposed using a Cr photomask on which an electrode pattern was formed. At this time, a diamond pattern was adopted as the electrode pattern of the Cr photomask. Next, the resist layer is developed to form a resist pattern. Using this resist pattern as a mask, the transparent conductive film (silver nanowire layer) is wet etched using a mixed acid etchant for Al, and then the resist layer is subjected to an alkaline developer. Was removed. As a result, an electrode pattern as shown in FIG. 17 (the unit of numerals other than the reference number in the figure is mm) was formed.
Black vinyl tape (VT-50 manufactured by Nichiban Co., Ltd.) is pasted on the surface of the base material opposite to the electrode pattern side, and the transparent double-sided adhesive sheet (manufactured by Nitto Denko Corporation, trade name: LUCIACS CS9621T) is used on the electrode pattern side. ), A glass plate (Matsunami Glass Industrial Co., Ltd., MICRO SLIDE GLASS S9213) was bonded.
A fluorescent lamp was projected on the glass surface, the electrode pattern was visually observed, and the electrode pattern invisibility was evaluated according to the following evaluation criteria.
-Evaluation criteria-
○: The pattern is difficult to visually recognize. Δ: The pattern is very difficult to visually recognize, but can be visually recognized depending on the angle. X: The pattern can be easily visually recognized. In Comparative Example 2, Example 3, and Example 4, the following steps are performed. The same result was obtained even when the electrode pattern was formed by the above method.
After coating and drying a silver nanowire ink (dispersion) to a PET substrate, the Cr photomask soft contact, then exposed to ultraviolet rays at a cumulative light quantity 200 mJ / cm ² using manufactured by Toshiba Lighting & Technology Corporation alignment exposure apparatus, an exposure portion Cured. Next, 100 mL of a 20% by mass aqueous acetic acid solution was sprayed in the form of a shower to remove the unexposed area and develop. Thereafter, calendering (nip width 1 mm, load 4 kN, speed 1 m / min) was performed, and the cured product was immersed in the nanoparticle dispersion solution as necessary to produce a transparent pattern electrode. Moreover, even if it performed the calendar process before ultraviolet curing, it was the same result.

<D) Evaluation of SEM observation>
About the obtained transparent pattern electrode, the scanning electron microscope (Scanning Electron Microscope, SEM) image of the transparent conductive film (silver nanowire layer) surface was image | photographed using Hitachi S-4700.

Each evaluation result is shown in Table 1 and FIGS. 18 to 23 (corresponding to Comparative Example 1, Examples 1-2, Comparative Example 2, and Examples 3-4, respectively).

From Table 1, it can be seen that by supporting black nanoparticles on the surface of the silver nanowire, the reflection L value is reduced, and the black floating and electrode pattern non-visibility are greatly improved.
Further, from Table 1, in Comparative Example 3 (transparent electrode in which nanoparticles are randomly (uniformly) dispersed in the binder layer), the light reflection of the metal nanowires cannot be sufficiently suppressed, and the reflection L value is low. It can be seen that the reduction effect is small and the electrode pattern non-visibility is not improved. Furthermore, compared with the comparative example 1, the total light transmittance has fallen.
Furthermore, from Table 1, in Comparative Example 5 (transparent electrode in which a colored compound is supported on metal nanowires instead of nanoparticles), the effect of suppressing light reflection of metal nanowires is compared with Examples 1-4. It turns out that it is inferior.
Moreover, when using carbon black nanoparticles (Cabot CAB-O-JET400, average particle size 130 nm, black) or carbon nanotubes (CARBOBYK-9810 manufactured by Big Chemie) instead of palladium nanoparticles, as nanoparticles, The effect of reducing the reflection L value was small, and the electrode pattern non-visibility was not improved. Furthermore, the total light transmittance has been greatly reduced.

  The nanoparticle-supported metal nanowire of the present invention, the dispersion containing the nanoparticle-supported metal nanowire, and the transparent conductive film containing the nanoparticle-supported metal nanowire and / or metal nanowire in which the nanoparticles are unevenly distributed in the vicinity Is particularly suitable for touch panels, but for applications other than touch panels (for example, organic EL electrodes, surface electrodes for solar cells, transparent antennas (wireless antennas for charging mobile phones or smartphones), prevention of condensation, etc. It can also be suitably used as a transparent heater that can be used.

DESCRIPTION OF SYMBOLS 1 Nanoparticle carrying | support metal nanowire 2 Metal nanowire 2a The surface of metal nanowire 3 Nanoparticle 10 Linker (organic low molecule)
20 Linker (organic polymer)
30 Transparent conductive film 31 Binder layer 40 Base material 50 Overcoat layer 60 Anchor layer 70 Hardened material 80 Nanoparticle dispersion solution 100 Press roll 110 Back roll 120 Transparent conductive film 130 PET base material 200 Electrode part 300 Insulation part X To metal nanowire Adsorbing functional group Y Functional group adsorbing to nanoparticles

Claims (9)

  A nanoparticle-supported metal nanowire, which is a metal nanowire supporting nanoparticles.   The nanoparticle-supported metal nanowire according to claim 1, wherein the surface of the nanoparticle absorbs light in a visible light region.   The nanoparticle-supporting metal nanowire according to claim 1, wherein the nanoparticle is at least one of a metal particle, a resin particle, and an inorganic particle.   The nanoparticle-supporting metal nanowire according to any one of claims 1 to 3, wherein the nanoparticle has an average particle diameter of 1 nm to 100 nm.   A dispersion liquid comprising the nanoparticle-supported metal nanowire according to claim 1. Metal nanowires,
A transparent conductive film comprising: nanoparticles supported on the metal nanowires and / or nanoparticles unevenly distributed in the vicinity of the metal nanowires. It is a manufacturing method of the transparent conductive film which manufactures the transparent conductive film of Claim 6,
Forming a dispersion film on a substrate using a dispersion containing metal nanowires, a binder, and a solvent;
Curing the dispersion film formed on the substrate;
The cured product obtained by curing the dispersion film is immersed in a nanoparticle dispersion solution containing nanoparticles and a solvent, or the cured product obtained by curing the dispersion film is subjected to nanoparticles and a solvent. Applying or printing a nanoparticle dispersion solution comprising:
The manufacturing method of the transparent conductive film characterized by including. It is a manufacturing method of the transparent conductive film which manufactures the transparent conductive film of Claim 6,
Forming the dispersion film on the substrate using the dispersion liquid according to claim 5 or a dispersion liquid containing nanoparticles, metal nanowires, a binder, and a solvent;
And a step of curing the dispersion film formed on the substrate.   A touch panel comprising the transparent conductive film according to claim 6.