JP2012003900A - Conductive film and method of manufacturing the same, touch panel, and integrated solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive film that has little light scatter to have excellent black tightness, has high transmissivity up to a long-wavelength range, and also has high conductivity and a method of manufacturing the same, a touch panel which has good visibility, and an integrated solar cell which has high conversion efficiency.SOLUTION: The conductive film at least includes metal nano-wires having an average short-axis length of equal to or less than 50 nm and an average long-axis length of equal to or larger than 5 μm, and is characterized in that when the conductive film is observed through a scanning electron microscope from a vertical direction to the surface of the conductive film, the number of intersections where one metal nanowire to be measured overlaps other metal nanowires is 2 to 200 per μm of the one metal nanowire.

Description

  The present invention relates to a conductive film, a method for manufacturing the conductive film, a touch panel, and an integrated solar cell.

  Solar cells are attracting attention as clean energy. In particular, thin film solar cells that use less raw materials are indispensable for the spread of solar cells in the future. On the other hand, increasing the conversion efficiency of solar cells is important from the viewpoint of space saving and low cost, and many studies have been made. In order to convert light of all wavelengths of sunlight falling on the earth into electrical energy, it has been devised to absorb light of longer wavelengths. For example, a so-called tandem type that combines materials having absorption from short wavelengths to long wavelengths, or materials having a large amount of absorption at long wavelengths such as CIGS solar cells, etc. are being studied. Has been obtained. Thus, in order to improve the conversion efficiency, the improvement of light absorption of long wavelengths has been studied. At this time, the light absorption (light transmittance) of the transparent electrode, which plays a role for taking out the solar cell as electric energy, is performed. Will also be important.

  In general, ITO (indium tin oxide) and zinc oxide, which are used as transparent electrodes in solar cells, are mainly subjected to N-type dopants for conductivity, but increasing the doping amount to increase conductivity There was a problem that the transmittance of long wavelength was lowered. However, in the case of using a solar cell having high absorption at a long wavelength, light for absorption in the long wavelength region cannot pass through the transparent electrode, which hinders efficiency increase. For this reason, attempts have been made to improve the long wavelength transmittance by devising the doping element and doping amount to be added to the oxide. However, these improvements alone are not sufficient, and further improvement in transmittance is desired.

  In recent years, ITO has been widely used as a transparent conductive material in touch panels whose demand is rapidly expanding due to the spread of portable game machines, mobile phones and the like. However, as described above, pen pressure durability is a problem as a color caused by low transmittance in the long wavelength region and a problem peculiar to the touch panel. In such cases, studies on transparent conductive films using silver nanowires have been reported. In this report, although silver nanowires are excellent in terms of transparency, low resistance, and reduction in the amount of metal used, synthesis at high temperatures using organic solvents is common, and synthesized silver Due to the thickness of the nanowire, haze is high and the contrast is remarkably reduced, and practical durability cannot be obtained unless a coating such as a photo-curing resin is applied to the outermost surface layer of the air. There is a problem that the resistance is increased, and further, the uniformity of the resistance in the surface is lowered, and an improvement thereof has been desired.

For example, Patent Document 1 describes that it is preferable that the average minor axis length of the metal nanowire is small and monodisperse for both transparency and high conductivity, but the number of intersections between the metal nanowires. There is no description about the crossing angle.
Further, it is described that in order to achieve transparency and low resistance in metal nanowires, it is necessary that one metal nanowire to be measured is in contact with a plurality of metal nanowires (Patent Literature). 2). Furthermore, it is described that it is ideal that the metal nanowires intersect in a lattice shape (90 degrees) (see Patent Documents 2 and 3).
However, these patent documents do not specifically show the number of intersections of metal nanowires or the numerical range of the intersection angle. Moreover, although the number of intersections between metal nanowires correlates with the aspect ratio and density of metal nanowires, there is no disclosure or suggestion about this.

  Accordingly, a conductive film and a method for manufacturing the conductive film having low light scattering, good black tightening, high transmittance up to a long wavelength region and high conductivity, a highly visible touch panel, and an integrated type with high conversion efficiency At present, prompt provision of solar cells is desired.

JP 2010-84173 A JP 2009-211978 A US Patent Application Publication No. 2009/0228131

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention relates to a conductive film and a conductive film manufacturing method that have low light scattering, good black tightening, high transmittance up to a long wavelength region, and high conductivity, and a highly visible touch panel and conversion efficiency. An object of the present invention is to provide a highly integrated solar cell.

Means for solving the problems are as follows. That is,
<1> A conductive film containing at least metal nanowires having an average minor axis length of 50 nm or less and an average major axis length of 5 μm or more,
When observed with a scanning electron microscope from a direction perpendicular to the surface of the conductive film, the number of intersections where one metal nanowire to be measured overlaps with another metal nanowire is the number of intersections of the one metal nanowire. The conductive film is characterized in that the number is 2 to 200 per μm.
<2> A conductive film containing at least metal nanowires having an average minor axis length of 50 nm or less and an average major axis length of 5 μm or more,
When observed with a scanning electron microscope from the direction perpendicular to the surface of the conductive film, the crossing angle on the narrow angle side at the intersection where one metal nanowire to be measured overlaps another metal nanowire is an average value. The conductive film is characterized by being 50 ° or more and less than 90 °.
<3> The conductive film according to any one of <1> to <2>, wherein an average minor axis length of the metal nanowire is 15 nm to 35 nm.
<4> The conductive film according to any one of <1> to <3>, wherein the metal nanowire is made of silver or an alloy of silver and a metal other than silver.
<5> The conductive film according to any one of <1> to <4>, wherein the metal nanowire has a curvature radius of 100 μm to 1,000 μm.
<6> The conductive film according to any one of <1> to <5>, wherein a ratio of spherical or rod-like particles having a major axis length of 0.1 μm or less is 10% or less.
<7> The conductive film according to any one of <1> to <6>, wherein the single degree of major axis length of the metal nanowire is 70% or more.
<8> At least a conductive layer forming step of forming a conductive layer by applying a conductive layer composition containing at least metal nanowires on the support,
In the conductive layer forming step, the conductive layer composition is applied by bar coating, and is performed twice or more by changing the application direction.
<9> The method for producing a conductive film according to <8>, including a cleaning step of cleaning the conductive layer with at least one of an organic solvent and an alkaline solution.
<10> The method for producing a conductive film according to any one of <8> to <9>, including a heating step of heating the conductive layer to 100 ° C. or higher.
<11> A touch panel or an integrated solar cell using the conductive film according to any one of <1> to <7>.

  According to the present invention, the conventional problems can be solved, the light scattering is small, the blackness is good, the transmittance is high up to a long wavelength region, and the conductive film has a high conductivity, and the method for manufacturing the conductive film, In addition, a highly visible touch panel and an integrated solar cell with high conversion efficiency can be provided.

1A to 1C are schematic diagrams illustrating a layer structure of a touch panel. 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 conductive films in the touch panel shown in FIG. FIG. 5 is a schematic cross-sectional view showing still another example of the touch panel.

(Conductive film)
The conductive film of the present invention contains at least metal nanowires, and contains a polymer and, if necessary, other components.

The shape, structure, size, and the like of the conductive film are not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape include a film shape and a sheet shape. Examples of the planar shape include a quadrangle and a circle. Examples of the structure include a single-layer structure and a laminated structure. The size can be appropriately selected depending on the application.
The conductive film is flexible and preferably transparent, and the transparent includes colorless and transparent as well as colored and transparent, translucent, and colored and translucent.
The conductive film may be patterned or unpatterned. 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, when observed with a scanning electron microscope (SEM) from the direction perpendicular to the surface of the conductive film, the number of intersections at which one metal nanowire to be measured overlaps with another metal nanowire is: The number of metal nanowires to be measured is 2 to 200, preferably 5 to 100, more preferably 8 to 50, per 1 μm of one metal nanowire. When the number of intersections is less than 2, high conductivity may not be obtained, and when it exceeds 200, transmittance may be lowered and black tightening may be insufficient and unacceptable.
Here, the intersection is a point (intersection) where the metal nanowires intersect each other when viewed from the direction perpendicular to the surface of the conductive film, and the metal nanowires do not necessarily need to be in contact with each other. It is preferable that it is the point (contact point) which metal nanowires are contacting at the point which lowers | hangs.
For example, when the number of the intersections is observed with a scanning electron microscope from the vertical direction with respect to the surface of the conductive film placed on a horizontal substrate, one metal nanowire as a measurement target is different from other metal nanowires. The overlapping intersections are measured, and the number of intersections per 1 μm of one metal nanowire that is the measurement target is obtained. For example, the number of intersections per 1 μm that avoids overlapping on the metal nanowires is obtained at 10 locations, and the average value is set as the number of intersections.
Selection of one metal nanowire which is a measurement object can be performed by selecting randomly on the electron microscope image of arbitrary magnification irrespective of the density of metal nanowire.

Moreover, in this invention, when observing with the scanning electron microscope from the perpendicular | vertical direction with respect to the said electrically conductive film surface, the narrow angle side in the intersection where one metal nanowire which is a measuring object overlaps with another metal nanowire is carried out. The crossing angle is preferably 50 degrees or more and less than 90 degrees as an average value, and preferably 75 degrees or more and less than 90 degrees as an average value. When the average crossing angle is less than 50 degrees, only a surface resistance equivalent to that of a conductive film that does not control the orientation of metal nanowires may be obtained.
The method for adjusting the average crossing angle will be described in the method for producing a conductive film, which will be described later, and is achieved by applying the metal nanowire-containing composition on the support twice or more times while changing the angle in the coating direction. Can do.
The average crossing angle is, for example, a protractor or a digitizer on the acute angle side of the angle formed by a straight line at the intersection of two arbitrary metal nanowires in a scanning electron microscope image or the angle formed by the tangents when curved. It can obtain | require by measuring an angle using. The average intersection angle is an average value of 20 arbitrary measurement data.

<Metal nanowires>
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.

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 particularly 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.

-Single degree of long axis length-
The single degree of major axis length in the metal nanowire is preferably 70% or more, and more preferably 80% to 100%. When the singleness of the major axis length is less than 70%, metal nanowires having no intersections at two or more points are generated, and the surface resistance is hardly lowered and the transmittance may be reduced.
The single degree of the major axis length is measured by measuring the major axis length of 100 arbitrary metal nanowires from, for example, a scanning electron microscope image, and is within a range of ± 30% of the average major axis length. It can be determined from the ratio (percentage) of the number of wires.

-Curvature radius-
The radius of curvature of the metal nanowire is preferably 100 μm to 1,000 μm, more preferably 300 μm to 900 μm, and still more preferably 500 μm to 800 μm. When the radius of curvature is less than 100 μm, the number of intersections of metal nanowires increases, but the number of intersections that become positions of connection and twist due to the substantial reduction of metal nanowire length increases, resulting in high resistance. When the thickness exceeds 1,000 μm, the resistance may be equivalent to that of a linear nanowire that is not substantially curved.
The radius of curvature of the metal nanowire can be measured by, for example, a method of obtaining the radius of curvature by approximating the nanowire of the scanning electron microscope image to an arc with a digitizer or the like.

The ratio of spherical or rod-like particles having a major axis length of 0.1 μm or less is preferably 10% or less, and more preferably 5% to 0%.
If the ratio exceeds 10%, the transmittance may be lowered and visibility may be lowered.
The ratio of spherical or rod-shaped particles having a major axis length of 0.1 μm or less is, for example, the number N of nanowires in a scanning electron microscope image and the number of spherical or rod-shaped particles R having a major axis length of 0.1 μm or less. Can be calculated by calculating R / N × 100.

-Aspect ratio-
The aspect ratio of the metal nanowire is preferably 10 or more. The aspect ratio generally means the ratio between the long side and the short side of the metal nanowire (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 metal nanowire with an electron microscope, it is only necessary to confirm whether the aspect ratio of the metal nanowire is 10 or more with one field of view of the electron microscope. Moreover, the aspect ratio of the whole metal nanowire can be estimated by measuring the major axis length and the minor axis length of the metal nanowire separately.

The aspect ratio of the metal nanowire 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 preferably 100 to 1,000,000. Is more preferable.
When the aspect ratio is less than 10, network formation by the metal nanowires may not be performed and sufficient conductivity may not be obtained. When the aspect ratio exceeds 1,000,000, the metal nanowires may be formed or handled thereafter. In this case, since the metal nanowires are entangled and aggregate before film formation, a stable liquid may not be obtained.

-Ratio of metal nanowires with an aspect ratio of 10 or more-
The ratio of the metal nanowires having an aspect ratio of 10 or more is preferably 50% or more, more preferably 60% or more, and even more preferably 75% or more in volume ratio in the total conductive composition. Hereinafter, the ratio of these metal nanowires may be referred to as “the ratio of metal nanowires”.
If the ratio of the metal nanowires is less than 50%, the conductive material that contributes to the conductivity may decrease and the conductivity may decrease. At the same time, a voltage concentration occurs because a dense network cannot be formed. , Durability may be reduced. In addition, particles having a shape other than metal nanowires 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 metal nanowire is, for example, when the metal nanowire is a silver nanowire, the silver nanowire aqueous dispersion is filtered to separate the silver nanowire from the other particles. The ratio of metal nanowires can be determined by measuring the amount of silver remaining on the filter paper and the amount of silver transmitted through the filter paper using an ICP emission analyzer. By observing the metal nanowires remaining on the filter paper with a TEM, observing the short axis length of 300 metal nanowires and examining their distribution, the short axis length is 200 nm or less and the long axis length It confirms that it is metal nanowire whose length is 1 micrometer or more. The filter paper has a short axis length of 200 nm or less in a TEM image, and the longest axis of particles other than metal nanowires 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 metal nanowire.

  Here, the average minor axis length and the average major axis length of the metal nanowire 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 metal nanowire are obtained by observing 300 metal nanowires with a transmission electron microscope (TEM) and calculating the average value. is there.

-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 further more preferable, and 40 to 170 degreeC is especially 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 Further preferred are alkali halides such as potassium bromide, potassium chloride and potassium iodide, and compounds that can be used in combination with the dispersion additives described below.
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.

<< Polymer >>
As the polymer, both a water-soluble polymer and a water-insoluble polymer can be suitably used.

-Water-soluble polymer-
The water-soluble polymer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, gelatin, gelatin derivatives, casein, agar, starch, polyvinyl alcohol, polyacrylic acid copolymer, carboxymethylcellulose, hydroxyethylcellulose , Polyvinyl pyrrolidone, dextran, and the like. These may be used individually by 1 type and may use 2 or more types together.
The mass ratio (A / B) of the metal nanowire content (A) and the water-soluble polymer content (B) is preferably 0.2 to 3.0, and preferably 0.5 to 2.5. More preferred.
When the mass ratio (A / B) is less than 0.2, there is a concern that the amount of the polymer is excessive with respect to the metal nanowire, and the resistance increases due to a slight variation in the coating amount. If it exceeds, the film strength may not be practically sufficient due to the small amount of polymer.

-Water-insoluble polymer-
The water-insoluble polymer has a function as a binder, and is a polymer that does not substantially dissolve in water near neutrality. The water-insoluble polymer specifically means a polymer having an SP value (calculated by the Okitsu method) of 18 MPa ^{1/2 to} 30 MPa ^1/2 .

As the SP value ^is preferably 18MPa ^1/2 ~30MPa ^1/2, more preferably 19MPa ^1/2 ~28MPa ^1/2, more preferably 19.5MPa ^1/2 ~27MPa 1/2.
The SP value is less than ^{18 MPa 1/2,} there are cases where to wash the adhered organic stains difficult, exceeds ^{30 MPa 1/2,} the higher the affinity for water, the coating film The conversion efficiency may decrease when a solar cell is manufactured, for example, because the absorption in the infrared region is increased due to the increase in water content.

Here, the SP value is calculated by the Okitsu method (Toshinao Okitsu, “Journal of the Adhesion Society of Japan” 29 (3) (1993)). Specifically, the SP value is calculated by the following formula. ΔF is a value described in the literature.
SP value (δ) = ΣΔF (Molar Attraction Constants) / V (molar volume)
When using a plurality of water-insoluble polymers, the SP value (σ) and the hydrogen bond term (σh) of the SP value are calculated by the following equations.

However, σn is the hydrogen bond term of the SP value or SP value of the water-insoluble polymer and water, Mn is the molar fraction of the water-insoluble polymer and water in the mixed solution, and Vn is the molar volume of the solvent. , N each represents an integer of 2 or more representing the type of solvent.

The water-insoluble polymer is not particularly limited as long as the SP value is 18 MPa ^{1/2 to} 30 MPa ^1/2 , but is not ethylenic in terms of adhesion of the coating film to the substrate and durability against sliding. Polymers having saturated groups are preferred. Among these, it is preferable that the side chain connected to the main chain contains at least one ethylenically unsaturated bond. A plurality of the ethylenically unsaturated bonds may be contained in the side chain. The ethylenically unsaturated bond may be included in the side chain of the water-insoluble polymer together with the branched and / or alicyclic structure and / or the acidic group.

The ethylenically unsaturated bond is bonded to the main chain of the water-insoluble polymer via at least one ester group (—COO—), and the water-insoluble polymer is composed of only the ethylenically unsaturated bond and the ester group. The side chain may be constituted. Further, it may have a divalent organic linking group between the main chain of the water-insoluble polymer and the ester group and / or between the ester group and the ethylenically unsaturated bond. The saturated bond may constitute a side chain of the water-insoluble polymer as “group having an ethylenically unsaturated bond”.
Examples of the divalent organic linking group include styrenes, (meth) acrylates, vinyl ethers, vinyl esters, (meth) acrylamides, etc., (meth) acrylates, vinyl esters, (meth ) Acrylamides are preferred, and (meth) acrylates are particularly preferred.

The ethylenically unsaturated bond is preferably arranged by introducing a (meth) acryloyl group.
The method for introducing a (meth) acryloyl group into the side chain of the water-insoluble polymer is not particularly limited and may be appropriately selected from known methods. For example, an epoxy group may be added to a repeating unit having an acidic group. Of adding (meth) acrylate having a hydroxyl group, adding a (meth) acrylate having an isocyanate group to a repeating unit having a hydroxyl group, and adding a (meth) acrylate having a hydroxyl group to a repeating unit having an isocyanate group Etc.
Among these, the method of adding (meth) acrylate having an epoxy group to a repeating unit having an acidic group is most preferable because it is the easiest to produce and is low in cost.

  The (meth) acrylate having an ethylenically unsaturated bond and an epoxy group is not particularly limited as long as it has these, and can be appropriately selected according to the purpose. For example, it is represented by the following structural formula (1). And a compound represented by the following structural formula (2) are preferred.

However, in the structural formula (1), R ¹ represents a hydrogen atom or a methyl group. L ¹ represents an organic group.

In the Structural formula (2), R ² represents a hydrogen atom or a methyl group. L ² represents an organic group. W represents a 4- to 7-membered aliphatic hydrocarbon group.

Among the compounds represented by the structural formula (1) and the structural formula (2), when used as a negative-type or positive-type resist in combination with a photocurable resin, in terms of good developability and film strength, A compound represented by the structural formula (1) is preferred. In the structural formulas (1) and (2), L ¹ and L ² are each independently more preferably an alkylene group having 1 to 4 carbon atoms.

  Although there is no restriction | limiting in particular as a compound represented by the said Structural formula (1) and Structural formula (2), For example, the following compounds (1)-(10) are mentioned.

As for mass ratio (A / C) of content (A) of the said metal nanowire, and content (C) of the said water-insoluble polymer, 0.2-3.0 are preferable, 0.5-2.5 Is more preferable.
If the mass ratio (A / C) is less than 0.2, there may be a problem of variation in resistance due to variation in coating amount, or the action of the solution in the present invention may be reduced. If it exceeds 1, practically sufficient strength may not be obtained in the coating film.
The content of the metal nanowires (coating amount) ^{is preferably,} more preferably 0.01g / ^{m 2} ~0.45g / m 2 it is ^{0.005g / m 2 ~0.5g / m 2} , 0 More preferably, it is .015 g / m ^{2 to} 0.4 g / m ² .

-Dispersant-
The dispersant is used to prevent and disperse the metal nanowires. The dispersant is not particularly limited as long as the metal nanowires can be dispersed, and can be appropriately selected according to the purpose. For example, a commercially available low molecular pigment dispersant or polymer pigment dispersant can be used. In particular, polymer dispersants having the property of adsorbing to metal nanowires are preferably used, such as polyvinylpyrrolidone, BYK series (manufactured by Big Chemie), Solsperse series (manufactured by Nippon Lubrizol, etc.), Ajisper series (Ajinomoto) Etc.).

  As content of the said dispersing agent, 0.1 mass part-50 mass parts are preferable with respect to 100 mass parts of said polymers, 0.5 mass part-40 mass parts are more preferable, and 1 mass part-30 mass parts are. Further preferred. If the content is less than 0.1 parts by mass, metal nanowires may aggregate in the dispersion, and if it exceeds 50 parts by mass, a stable coating film cannot be formed in the coating process. Application unevenness may occur.

<Other ingredients>
Examples of the other components include various additives such as surfactants, antioxidants, sulfurization inhibitors, metal corrosion inhibitors, viscosity modifiers, preservatives, and the like as necessary.

  The conductive film of the present invention may be formed on a support, in which case it may be referred to as a conductor.

-Support-
The support is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a transparent glass substrate, a synthetic resin sheet, a film, a metal substrate, other ceramic plates, and a semiconductor substrate having a photoelectric conversion element. Can be mentioned. If necessary, these substrates can be subjected to pretreatment such as chemical treatment such as a silane coupling agent, plasma treatment, ion plating, sputtering, gas phase reaction, and vacuum deposition.
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 and film include polyethylene terephthalate (PET), polycarbonate, polyethersulfone, polyester, acrylic resin, vinyl chloride resin, aromatic polyamide resin, polyamideimide, and polyimide.
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 support 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 support that is colored to the extent that the object of the present invention is not hindered can also be used.

The thickness of the support is preferably 1 μm to 5,000 μm, more preferably 3 μm to 4,000 μm, and still more preferably 5 μm to 3,000 μm.
If the thickness is less than 1 μm, the yield may decrease due to the difficulty of handling in the coating process. If the thickness exceeds 5,000 μm, the thickness and mass of the support may be a problem in portable applications. It may become.

(Manufacturing method of conductive film)
The manufacturing method of the electrically conductive film of this invention includes a conductive layer formation process at least, and also includes a washing | cleaning process, a heating process, and another process as needed.

<Conductive layer formation process>
The conductive layer forming step is a step of forming a conductive layer by applying a conductive layer composition containing at least metal nanowires on a support.
The support and the metal nanowire can be appropriately selected from those described above.
In the said conductive layer formation process, the intersection angle in the intersection of metal nanowires can be controlled by performing application | coating of the conductive layer composition on a support body 2 times or more by changing an application direction.
Specifically, it is preferable to apply by changing the second application direction from 45 degrees to 90 degrees with respect to the first application direction.

There is no restriction | limiting in particular as the application | coating method of the said conductive layer composition, According to the objective, it can select suitably, For example, a bar coat method, a spin coat method, a roll coat method, a slit coat method etc. are mentioned. Among these, the bar coating method is particularly preferable because the orientation of the metal nanowire can be easily controlled.
The coating speed is preferably such that the difference between the peripheral speed of the bar and the conveying speed of the support is 100 mm / min to 500 mm / min.

The coating amount of the metal nanowires as (content) is not particularly limited and may be appropriately selected depending on the intended ^purpose, it is preferably ^{0.005g / m 2 ~0.5g / m 2} , 0 more preferably ^{.01g / m 2 ~0.45g / m 2} , 0.015g / m 2 ~0.4g / m 2 is more preferable.
When the coating amount is less than 0.005 g / m ² , there may be a portion where the resistance is locally increased, and the in-plane resistance distribution may be deteriorated, and when it exceeds 0.5 g / m ^2. The haze may deteriorate due to the aggregation of metal nanowires during drying after coating.

There is no restriction | limiting in particular as thickness of the said conductive layer, According to the objective, it can select suitably, 20 nm-5,000 nm are preferable, 25 nm-4,000 nm are more preferable, 30 nm-3,500 nm are still more preferable.
If the thickness is less than 20 nm, the average minor axis length of the metal nanowires is not changed, and the film strength may be reduced. If the thickness exceeds 5,000 nm, the conductive layer is cracked and transmitted. Rate and haze may deteriorate.

<Washing process>
The washing step is a step of washing the conductive layer with at least one of an organic solvent and an alkaline solution. By washing the conductive layer with at least one of an organic solvent and an alkaline solution, excess portions between the metal nanowires can be removed, the number of contact points between the metal nanowires increases, and the surface resistance decreases. The conductivity of the conductive layer can be improved.

The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alcohols such as methanol, ethanol, propanol, isopropanol and butanol, cyclic ethers such as dioxane and tetrahydrofuran, and ketones such as acetone. And the like.
There is no restriction | limiting in particular as the washing | cleaning method by the said organic solvent, Although it can select suitably according to the objective, For example, the organic solvent is poured over using the method of immersing an electrically conductive film in the said organic solvent, a shower, or spraying. And a method of applying with a napkin soaked with an organic solvent.

  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 a washing | cleaning method by the said alkaline solution, Although it can select suitably according to the objective, For example, the method of immersing an electrically conductive film in the said alkaline solution, pouring an organic solvent using shower or spray And a method of applying with a napkin soaked with an alkaline solution.
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.

<Heating process>
The heating step is a step of heating the conductive layer to 100 ° C. or higher.
The heating temperature in the heating step is preferably 100 ° C or higher, more preferably 120 ° C to 250 ° C. If the heating temperature is less than 100 ° C., the conductivity improving effect may not be obtained.

<Other processes>
The manufacturing method of the electrically conductive film of this invention may include the patterning process as needed.
The patterning step is a step of pattern-exposing and developing the conductive layer.
There is no restriction | limiting in particular as a light source in the said exposure, Although it can select suitably according to a use etc., an ultraviolet irradiation device, an ultraviolet irradiation lamp, etc. are preferable, for example.
The development can be substituted in the alkali washing step when washing with an alkaline solution in the washing step.

The surface resistance of the conductive film of the present invention is preferably 0.1Ω / □ to 5,000Ω / □, and more preferably 0.1Ω / □ to 30Ω / □.
The surface resistance can be measured using, for example, a surface resistance meter (Loresta-GP MCP-T600, manufactured by Mitsubishi Chemical Corporation).
The light transmittance of the conductive film of the present invention is preferably 70% or more, and more preferably 80% or more.
Here, the light transmittance can be measured by, for example, a self-recording spectrophotometer (UV2400-PC, manufactured by Shimadzu Corporation).

  The conductive film 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, an organic EL display electrode It is widely applied to 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, a display element, and an integrated solar cell are particularly preferable.

<Display element>
A liquid crystal display element as a display element used in the present invention includes an element substrate provided with the conductive film of the present invention patterned on a substrate as described above, and a color filter substrate as a counter substrate. Are combined by heat treatment, injecting liquid crystal, and sealing the injection port. At this time, the conductive film of the present invention is also preferably used for the conductive film formed on the color filter.
Further, after the liquid crystal is spread on the element substrate, the liquid crystal display element may be manufactured by superimposing the substrates and sealing the liquid crystal so as not to leak.
In addition, there is no restriction | limiting in particular about the liquid crystal used for the said liquid crystal display element, ie, a liquid crystal compound, and a liquid crystal composition, Any liquid crystal compound and liquid crystal composition can be used.

(Touch panel)
The touch panel of the present invention is not particularly limited as long as it has the conductive film of the present invention, and can be appropriately selected according to the purpose. For example, a surface capacitive touch panel, a projection capacitive touch panel, Examples include a resistive touch panel.

Here, it is preferable that the touch panel has an antireflection film as described below.
<Antireflection film>
The antireflection film is produced by forming a hard coat layer and an antireflection layer on a transparent support.
Here, FIG. 1A to FIG. 1C are schematic views showing a layer structure of the touch panel.
1A includes a display 101, a touch panel 130, and an antireflection film 120. The touch panel 130 includes a first electrode 105, a transparent substrate 104, a second electrode 103, and a transparent adhesive 102. The antireflection film 120 includes an antireflection layer 109 and a hard coat layer 108.
1B includes a display 101, a touch panel 130, and an antireflection film 120. The touch panel 130 includes a protective resin layer 110, a first electrode 105, a transparent substrate 104, and a second electrode 103. And the transparent adhesive 102, and the antireflection film 120 includes an antireflection layer 109 and a hard coat layer 108.
1C includes a display 101, a touch panel 130, and an antireflection film 120. The touch panel 130 includes a transparent adhesive 106, a first electrode 105, a transparent substrate 104, and a second electrode 103. The antireflection film 120 includes an antireflection layer 109, a hard coat layer 108, and a transparent film 107.

-Transparent support-
Since the transparent support is used on the viewer-side surface of the image display device, the transparent support is required to be a colorless film having high light transmittance and excellent transparency. As such a transparent support, it is preferable to use a plastic film.
Examples of the polymer forming the plastic film include cellulose acylate (for example, cellulose triacetate such as TAC-TD80U, TD80UF, cellulose diacetate, cellulose acetate propionate, and cellulose acetate butyrate manufactured by Fuji Film Co., Ltd.), polyamide, Polycarbonate, polyester (for example, polyethylene terephthalate, polyethylene naphthalate), polystyrene, polyolefin, norbornene resin (Arton: trade name, manufactured by JSR Corporation), amorphous polyolefin (ZEONEX: trade name, manufactured by Nippon Zeon Corporation), ( (Meth) acrylic resin (ACRYPET VRL20A: trade name, manufactured by Mitsubishi Rayon Co., Ltd., JP-A-2004-70296 and JP-A-2006-17146 And the like described in JP-ring structure-containing acrylic resin). Among these, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, polyethylene terephthalate, and polyethylene naphthalate are preferable, and cellulose triacetate is particularly preferable.

-Hard coat layer-
The antireflection film is preferably provided with a hard coat layer in order to impart physical strength of the film. The hard coat layer may be composed of a laminate of two or more layers.

  The refractive index of the hard coat layer is preferably 1.48 to 1.90, more preferably 1.50 to 1.80, from the optical design for obtaining an antireflection film. Preferably, it is 1.52-1.65. Since there is at least one low refractive index layer on the hard coat layer, when the refractive index is too small, the antireflection property is lowered, and when it is too large, the color of the reflected light tends to be strong.

  The thickness of the hard coat layer is preferably 0.5 μm to 50 μm, and preferably 1 μm to 20 μm, from the viewpoint of imparting sufficient durability and impact resistance to the film. More preferably, the thickness is 2 μm to 15 μm, more preferably 3 μm to 10 μm. Further, the strength of the hard coat layer is preferably 2H or more, more preferably 3H or more, and further preferably 4H or more, in a pencil hardness test. Further, the hard coat layer is preferably as the wear amount of the test piece before and after the test is smaller in the Taber test according to JIS K5400.

  The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound. For example, it can be formed by applying a composition containing an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer on a transparent support and subjecting the polyfunctional monomer or polyfunctional oligomer to a crosslinking reaction or a polymerization reaction. . The functional group of the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is 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 specific compounds, monomers described in paragraphs [0087] and [0088] of JP-A-2006-30740 can be used, and curing described in paragraph [0089] of JP-A-2006-30740 can be used. The method can be used. In the case of photopolymerization, the photopolymerization initiator described in paragraphs [0090] to [0093] of JP-A-2006-30740 can be used.

  The hard coat layer contains matte particles having an average particle size of 1.0 μm to 10.0 μm, preferably 1.5 μm to 7.0 μm, such as inorganic compound particles or resin particles, for the purpose of imparting internal scattering properties. May be. As these particles, for example, the particles described in paragraph [0114] of JP-A-2006-30740 can be used.

  For the binder of the hard coat layer, for the purpose of controlling the refractive index of the hard coat layer, a high refractive index monomer or inorganic fine particles having a size that does not cause light scattering (the primary particle diameter is 10 nm to 200 nm), or both are used. 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.

-Antireflection layer-
The antireflection film is a film in which an antireflection layer is formed on the hard coat layer and utilizes optical interference. Therefore, the antireflection layer preferably has a refractive index and an optical thickness described below. The antireflection layer may be a single layer, but when a lower reflectance is required, a plurality of antireflection layers are laminated. In the lamination of the plurality of antireflection layers, optical interference layers having different refractive indexes may be alternately laminated, or two or more optical interference layers having different refractive indexes may be laminated. Specifically, an embodiment in which only a low refractive index layer is provided on the hard coat layer, an embodiment in which a high refractive index layer and a low refractive index layer are provided in this order on the hard coat layer, an intermediate refractive index layer on the hard coat layer, A mode in which a high refractive index layer and a low refractive index layer are provided in this order is commonly used. Note that low, medium, and high in the refractive index layer are expressions of the relative magnitude relationship of the refractive index.
The refractive index of the low refractive index layer is preferably set lower than the refractive index of the hard coat layer. When the refractive index difference between the low refractive index layer and the hard coat layer is too small, the antireflection property is lowered, and when it is too large, the color of the reflected light tends to be strong. The difference in refractive index between the low refractive index layer and the hard coat layer is preferably 0.01 or more and 0.40 or less, more preferably 0.05 or more and 0.30 or less (paragraph [0080] of JP2009-201727A. 〕reference).
The refractive index and thickness of each layer preferably satisfy the following.

  The refractive index of the low refractive index layer is preferably 1.20 to 1.46, more preferably 1.25 to 1.42, and still more preferably 1.30 to 1.38. . The thickness of the low refractive index layer is preferably 50 nm to 150 nm, and more preferably 70 nm to 120 nm.

  In order to construct the low refractive index layer on the high refractive index layer and produce an antireflection film, the refractive index of the high refractive index layer is preferably 1.55 to 2.40, It is more preferably 1.60 to 2.20, further preferably 1.65 to 2.10, and particularly preferably 1.80 to 2.00.

  When an antireflective film is prepared by coating a medium refractive index layer, a high refractive index layer, and a low refractive index layer in order from the support, the refractive index of the high refractive index layer is 1.65 to 2.40. It is preferable that it is preferably 1.70 to 2.20. The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The middle refractive index layer preferably has a refractive index of 1.55 to 1.80. In addition, the thickness of the said high refractive index layer and the said medium refractive index layer can be made into the optical thickness according to the range of refractive index.

-Low refractive index layer-
The low refractive index layer is preferably cured after the layer is formed. The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less.

A preferred composition for forming the low refractive index layer is preferably a composition containing at least one of the following.
(1) A composition containing a fluorine-containing polymer having a crosslinkable or polymerizable functional group (2) A composition comprising as a main component a hydrolysis-condensation product of a fluorine-containing organosilane material (3) Two or more ethylenes And a composition containing a monomer having an unsaturated group and inorganic fine particles having a hollow structure.

(1) Fluorine-containing compound having a crosslinkable or polymerizable functional group The fluorine-containing compound having a crosslinkable or polymerizable functional group includes a fluorine-containing monomer and a monomer having a crosslinkable or polymerizable functional group. A polymer can be mentioned.
Among the above-mentioned copolymers, as a copolymer having a main chain composed only of carbon atoms and comprising a fluorine-containing vinyl monomer polymer unit and a polymer unit having a (meth) acryloyl group in the side chain, JP-A P-1 to P-40 described in paragraphs [0043] to [0047] of 2004-45462 can be used. Further, as a fluorine-containing polymer into which a silicone component is introduced for improving scratch resistance and slipperiness, a graft polymer having a polymer unit containing a polysiloxane moiety in the side chain and a fluorine atom in the main chain is disclosed in JP The compounds described in Tables 1 and 2 of paragraphs [0074] to [0076] of 2003-222702 can be used, and the main chain contains an ethylenically unsaturated group-containing fluorine containing a structural unit derived from a polysiloxane compound. As the polymer, compounds described in JP-A No. 2003-183322 can be used.

  As described in JP 2000-17028 A, a curing agent having a polymerizable unsaturated group may be used in combination with the polymer. Moreover, combined use with the compound which has a fluorine-containing polyfunctional polymerizable unsaturated group as described in Unexamined-Japanese-Patent No. 2002-145952 is also preferable. Examples of the compound having a polyfunctional polymerizable unsaturated group include the monomer having two or more ethylenically unsaturated groups. Moreover, the hydrolysis-condensation product of the organolane described in Unexamined-Japanese-Patent No. 2004-170901 is also preferable, and the hydrolysis-condensation product of the organosilane containing a (meth) acryloyl group is especially preferable. These compounds are particularly preferred because they have a large combined effect for improving scratch resistance, particularly when a compound having a polymerizable unsaturated group is used in the polymer body.

  When the polymer itself does not have sufficient curability, the necessary curability can be imparted by blending a crosslinkable compound. For example, when the polymer body contains a hydroxyl group, various amino compounds are preferably used as the curing agent. The amino compound used as the crosslinkable compound is, for example, a compound containing one or both of a hydroxyalkylamino group and an alkoxyalkylamino group in total, specifically, for example, a melamine compound, Examples include urea compounds, benzoguanamine compounds, glycoluril compounds, and the like. For curing these compounds, an organic acid or a salt thereof is preferably used.

(2) Hydrolyzed condensate of fluorine-containing organosilane material The composition mainly composed of the hydrolyzed condensate of the fluorine-containing organosilane compound is also preferable because of its low refractive index and high coating surface hardness. A condensate of a tetraalkoxysilane with a hydrolyzable silanol-containing compound at one or both ends with respect to the fluorinated alkyl group is preferred. Specific compositions are described in JP-A Nos. 2002-265866 and 2002-317152.

(3) A composition containing a monomer having two or more ethylenically unsaturated groups and inorganic fine particles having a hollow structure As yet another preferred embodiment, a low refractive index layer comprising low refractive index particles and a binder can be mentioned. . The low refractive index particles may be organic or inorganic, but particles having pores inside are preferable. Specific examples of the hollow particles are described in silica-based particles described in JP-A No. 2002-79616. The particle refractive index is preferably 1.15 to 1.40, more preferably 1.20 to 1.30. Examples of the binder include monomers having two or more ethylenically unsaturated groups described in the section of the hard coat layer.

  It is preferable to add the polymerization initiator described on the page of the antiglare layer to the low refractive index layer. When a radically polymerizable compound is contained, it is preferable to add 1 part by mass to 10 parts by mass with respect to 100 parts by mass of the compound, and it is more preferable to add 1 part by mass to 5 parts by mass.

  In the low refractive index layer, inorganic particles can be used in combination. In order to impart scratch resistance, fine particles having a particle size of 15% to 150%, preferably 30% to 100%, more preferably 45% to 60% of the thickness of the low refractive index layer can be used. .

  For the purpose of imparting antifouling properties, water resistance, chemical resistance, slipping properties and the like, a known polysiloxane-based or fluorine-based antifouling agent, slipping agent, etc. are appropriately added to the low refractive index layer. be able to.

-High refractive index layer / Medium refractive index layer-
As described above, the antireflection film can be provided with a layer having a high refractive index between the low refractive index layer and the hard coat layer to enhance the antireflection property.
The high refractive index layer and the medium refractive index layer are preferably formed from a curable composition containing high refractive inorganic fine particles and a binder. As the high refractive index inorganic fine particles that can be used here, the high refractive index inorganic fine particles that can be contained to increase the refractive index of the hard coat layer can be used.

  The high refractive index layer and the medium refractive index layer are preferably a binder precursor (for example, an ionizing radiation curable polyfunctional monomer described later) necessary for forming a matrix in a dispersion in which inorganic particles are dispersed in a dispersion medium. And a polyfunctional oligomer), a photopolymerization initiator, and the like to form a coating composition for forming a high refractive index layer and a medium refractive index layer, and coating for forming a high refractive index layer and a medium refractive index layer on a transparent support. Preferably, the composition is applied and cured by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound (for example, a polyfunctional monomer or polyfunctional oligomer).

Furthermore, it is preferable to cause the binder of the high refractive index layer and the medium refractive index layer to undergo a crosslinking reaction or a polymerization reaction with the dispersant simultaneously with or after the coating of the layer.
The binder of the high refractive index layer and the medium refractive index layer produced in this way is, for example, the above-mentioned preferred dispersant and ionizing radiation curable polyfunctional monomer or polyfunctional oligomer are crosslinked or polymerized to form a binder. The anionic group of the dispersant is incorporated. Furthermore, the binder of the high refractive index layer and the medium refractive index layer has a function in which the anionic group maintains the dispersed state of the inorganic particles, and the crosslinked or polymerized structure imparts film forming ability to the binder and contains inorganic particles. To improve the physical strength, chemical resistance and weather resistance of the high refractive index layer and medium refractive index layer.

The binder of the high refractive index layer is added in an amount of 5% by mass to 80% by mass with respect to the solid content of the coating composition of the layer.
The content of the inorganic particles in the high refractive index layer is preferably 10% by mass to 90% by mass, more preferably 15% by mass to 80% by mass with respect to the mass of the high refractive index layer. It is still more preferable that it is mass%-75 mass%. Two or more kinds of the inorganic particles may be used in combination in the high refractive index layer.
When the low refractive index layer is provided on the high refractive index layer, the refractive index of the high refractive index layer is preferably higher than the refractive index of the transparent support.

The thickness when the high refractive index layer is used as an optical interference layer is preferably 30 nm to 200 nm, more preferably 50 nm to 170 nm, and still more preferably 60 nm to 150 nm.
The haze of the high refractive index layer and the medium refractive index layer is preferably as low as possible. The haze is preferably 5% or less, more preferably 3% or less, and still more preferably 1% or less.

  In the present invention, the preferable integrated reflectance of the antireflection antiglare film provided with the low refractive index layer is preferably 3.0% or less, more preferably 2.0% or less, and 1.5 More preferably, it is 0.3% or less.

  In the present invention, it is preferable to further reduce the surface free energy of the surface of the low refractive index layer from the viewpoint of improving the antifouling property. Specifically, it is preferable to use a fluorine-containing compound or a compound having a polysiloxane structure for the low refractive index layer. Further, an antifouling layer containing the following compound may be provided on the low refractive index layer separately from the low refractive index layer.

  Examples of the additive having a polysiloxane structure include a reactive group-containing polysiloxane {for example, “KF-100T”, “X-22-169AS”, “KF-102”, “X-22-3701IE”, “X-22”. -164B "," X-22-5002 "," X-22-173B "," X-22-174D "," X-22-167B "," X-22-161AS "(product name), Shin-Etsu “AK-5”, “AK-30”, “AK-32” (trade name), manufactured by Toa Gosei Co., Ltd .; “Silaplane FM0725”, “Silaplane FM0721” (trade name) In addition, it is also preferable to add, for example, manufactured by Chisso Corporation. Moreover, the silicone type compound of Table 2 and Table 3 of Unexamined-Japanese-Patent No. 2003-112383 can also be used preferably. These polysiloxanes are preferably added in the range of 0.1% by mass to 10% by mass of the total solid content of the low refractive index layer, and more preferably 1% by mass to 5% by mass.

<< Preparation Method of Antireflection Film >>
The antireflection film can be formed by the following coating method, but is not limited thereto.

−Preparation work for application−
First, a coating solution containing components for forming each layer such as a hard coat layer and an antireflection layer is prepared. Usually, since the coating liquid is mainly an organic solvent system, it is necessary to suppress the water content to 2% by mass or less and to seal it to suppress the volatilization amount of the solvent. The organic solvent to be used is selected according to the material used for each layer. In order to obtain the uniformity of the coating solution, a stirrer or a disperser is appropriately used.
The prepared coating solution is preferably filtered before coating so as not to cause a coating failure. It is preferable to use a filter having a pore size as small as possible within a range in which the components in the coating solution are not removed, and the filtration pressure is appropriately selected at 1.5 MPa or less. The filtered coating solution is preferably ultrasonically dispersed immediately before coating to defoam and retain the dispersion.
The transparent support used in the present invention may be subjected to a heat treatment for correcting the base deformation or a surface treatment for improving the coating property and the adhesiveness with the coating layer before coating. Specific methods for the surface treatment include corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, alkali treatment, and ultraviolet irradiation treatment. In addition, as described in JP-A-7-333433, it is preferable to provide an undercoat layer.

  Furthermore, it is preferable to provide a dust removing step as a pre-application step, and as a dust removing method used therefor, the method described in paragraph [0119] of JP 2010-32795 A can be used. In addition, it is particularly preferable to remove static electricity on the transparent support before performing such a dust removal step from the viewpoint of increasing dust removal efficiency and suppressing dust adhesion. As such a static elimination method, the method described in paragraph [0120] of JP 2010-32795 A can be used. Furthermore, the flatness of the film may be secured and the adhesiveness may be improved by the methods described in paragraphs [0121] and [0123] of JP2010-32795A.

-Application process-
Each layer of the antireflection film can be formed by the following coating method, but is not limited to this method. Dip coating method, air knife coating method, curtain coating method, roller coating method, wire bar coating method, gravure coating method, extrusion coating method (die coating method) (US Pat. No. 2,681,294, WO 05/123274) A known method such as a microgravure coating method is used, and among these, a microgravure coating method and a die coating method are preferable. The microgravure coating method is described in paragraphs [0125] and [0126] of JP 2010-32795 A, and the die coating method is described in paragraphs [0127] and [0128] of JP 2010-32795 A. These methods can also be used in the present invention. It is preferable in terms of productivity to apply at a speed of 20 m / min or more by using a die coating method.

-Drying process-
The antireflection film is preferably applied directly on the transparent support or via another layer and then conveyed by a web to a heated zone to dry the solvent.
Various knowledges can be used as a method for drying the solvent. As specific knowledge, descriptions in JP-A No. 2001-286817, JP-A No. 2001-314798, JP-A No. 2003-126768, JP-A No. 2003-315505, JP-A No. 2004-34002, etc. Technology.

  Regarding the temperature conditions of the drying zone, the respective conditions described in paragraph [0130] of JP 2010-32795 A, and the conditions of the drying air are described in paragraph [0131] of JP 2010-32795 A, respectively. Can be used.

-Curing process-
The antireflection film can pass through a zone for curing each coating film by ionizing radiation and / or heat as a web after the solvent is dried or at a later stage of drying to cure the coating film. The ionizing radiation species in the present invention is not particularly limited, and is appropriately selected from ultraviolet rays, electron beams, near ultraviolet rays, visible light, near infrared rays, infrared rays, X-rays, and the like according to the type of the curable composition forming the film. However, ultraviolet rays and electron beams are preferred, and ultraviolet rays are particularly preferred because they are easy to handle and high energy can be easily obtained.

  As the ultraviolet light source for photopolymerizing the ultraviolet curable compound, for example, the light source described in paragraph [0133] of JP 2010-32795 A can be used. As the electron beam, for example, the electron beam described in paragraph [0134] of JP 2010-32795 A can be used. Moreover, about irradiation conditions, irradiation light quantity, and irradiation time, the conditions as described in Paragraph [0135] and [0138] of Unexamined-Japanese-Patent No. 2010-32795 can be used, for example. Further, the film surface temperature, oxygen concentration, and oxygen concentration control method before and after the irradiation are described in, for example, paragraphs [0136], [0137], [0139] to [0144] of JP 2010-32795 A. Conditions and methods can be used.

-Handling for continuous production-
In order to continuously produce the antireflection film, a step of continuously feeding a roll-shaped transparent support film, a step of applying and drying a coating liquid, a step of curing a coating film, A step of winding the support film is performed.

  The above process may be performed every time each layer is formed, or a plurality of coating units-drying chambers-curing units may be provided (so-called tandem method) to form each layer continuously.

In order to produce the antireflection film, as described above, simultaneously with the microfiltration operation of the coating solution, the coating process in the coating unit and the drying process performed in the drying chamber are performed in a high clean air atmosphere, and It is preferable that dust and dust on the transparent support film are sufficiently removed before application. The air cleanliness of the coating process and the drying process is preferably class 10 (353 particles / m ³ or less of particles having a size of 0.5 μm or more) based on the standard of air cleanliness in the US Federal Standard 209E, class 1 It is more preferable that the particle size is 35.5 particles / m ³ or less (0.5 μm or more). In addition, it is more preferable that the degree of air cleanliness is high also in the feeding and winding parts other than the coating-drying process.

  In order to maintain the sharpness of the image, it is preferable to adjust the transparency of the transmitted image in addition to adjusting the surface shape of the antireflection film as smoothly as possible. The transmitted image definition of the antireflection film of the present invention is preferably 60% or more. The transmitted image clarity is generally an index indicating the degree of blurring of an image reflected through a film, and the larger this value, the clearer and better the image viewed through the film. The transmitted image definition is preferably 70% or more, and more preferably 80% or more.

The antireflection film can be used as a surface film on the viewing side of an image display device. The image display device can be applied to various display devices such as various liquid crystal display devices, plasma displays, organic ELs, touch panels. Depending on the properties of the outermost surface of the image display device using the antireflection film, an adhesive layer may be provided on the side surface of the antireflection film that does not have the transparent support coating layer, or the support surface may be saponified. It can be attached to an image display device.
As a method for saponifying the surface of the transparent support that does not have a coating layer, for example, the techniques described in paragraphs [0149] to [0160] of JP 2010-32795 A can be used.

Here, an example of the surface capacitive touch panel will be described with reference to FIG. In FIG. 2, the touch panel 10 includes a transparent conductive film 12 so as to uniformly cover the surface of the transparent substrate 11, and an external detection circuit (not shown) is formed on the transparent conductive film 12 at the end of the transparent substrate 11. The electrode terminal 18 for electrical connection is formed.
In the figure, reference numeral 13 denotes a transparent conductive film serving as a shield electrode, reference numerals 14 and 17 denote protective films, reference numeral 15 denotes an intermediate protective film, and reference numeral 16 denotes an antiglare film.
When an arbitrary point on the transparent conductive film 12 is touched with a finger or the like, the transparent conductive film 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 conductive film 22 and a transparent conductive film 23 arranged to cover the surface of the transparent substrate 21, and an insulating layer 24 that insulates the transparent conductive film 22 and the transparent conductive film 23. The insulating cover layer 25 that generates a capacitance between the contact object such as a finger and the transparent conductive film 22 or the transparent conductive film 23 detects the position of the contact object such as the finger. Depending on the configuration, the transparent conductive films 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 conductive film 22 or the transparent conductive film 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 conductive film 22 and the transparent conductive film 23 are viewed from the plane.
The touch panel 20 is provided with a plurality of transparent conductive films 22 capable of detecting positions in the X-axis direction and a plurality of transparent conductive films 23 in the Y-axis direction so as to be connectable to external terminals. The transparent conductive film 22 and the transparent conductive film 23 can detect contact information at multiple points even when a plurality of contact objects such as fingertips come into contact with each other.
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 conductive film by the some transparent conductive film 22 and the some transparent conductive film 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 is in contact with the transparent conductive film 32 through the substrate 31 on which the transparent conductive film 32 is disposed, the spacers 36 disposed on the transparent conductive film 32, and the air layer 34. A possible transparent conductive film 33 and a transparent film 35 disposed on the transparent conductive film 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 conductive film 32 and the transparent conductive film 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.

(Integrated solar cell)
The integrated solar cell of the present invention uses the conductive film of the present invention.
There is no restriction | limiting in particular as said integrated solar cell (henceforth a solar cell device), What is generally used as a solar cell device can be used. For example, a single crystal silicon solar cell device, a polycrystalline silicon solar cell device, an amorphous silicon solar cell device composed of a single junction type or a tandem structure type, gallium arsenide (GaAs), indium phosphorus (InP), etc. III-V compound semiconductor solar cell devices, II-VI compound semiconductor solar cell devices such as cadmium tellurium (CdTe), copper / indium / selenium system (so-called CIS system), copper / indium / gallium / selenium system ( So-called CIGS-based), copper / indium / gallium / selenium / sulfur-based (so-called CIGS-based) I-III-VI group compound semiconductor solar cell devices, dye-sensitized solar cell devices, organic solar cell devices, etc. Can be mentioned. Among these, in the present invention, the solar cell device is an amorphous silicon solar cell device constituted by a tandem structure type or the like, a copper / indium / selenium system (so-called CIS system), copper / indium / gallium / A selenium-based (so-called CIGS-based), copper / indium / gallium / selenium / sulfur-based (so-called CIGS-based) I-III-VI group compound semiconductor solar cell device is preferable.

  In the case of an amorphous silicon solar cell device composed of a tandem structure type or the like, amorphous silicon, a microcrystalline silicon thin film layer, a thin film containing germanium in these, and further, a tandem structure of two or more layers is a photoelectric conversion layer. Used as For film formation, plasma CVD or the like is used.

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

(Preparation Example 1)
-Preparation of silver nanowire dispersion (1)-
The following additive solutions A, G, and H were prepared in advance.
[Additive liquid A]
0.56 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 and 0.05 g of hydroxylamine with 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 the additive solution H and 206 mL of the additive solution G were added through a funnel while stirring at 20 ° C. (first stage). To this solution, 206 mL of the 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 65 ° C. at 3 ° C./min. Then, the stirring rotation speed was reduced to 200 rpm and heated for 8 hours.
After cooling the obtained 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 aqueous dispersion was put into a stainless cup, and the ultrafiltration was performed by operating the 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 dispersion (1).
The average minor axis length of silver nanowires in the obtained silver nanowire dispersion (1), the average major axis length, the coefficient of variation of minor axis length, and the ratio of silver nanowires with an aspect ratio of 10 or more The measurement was performed as follows. The results are shown in Table 1.

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

<Coefficient of variation of metal nanowire minor axis length>
Using a transmission electron microscope (TEM; JEM-2000FX, JEM-2000FX), 300 short-axis lengths of metal nanowires were observed, and the short-axis length of metal nanowires was measured from the average value. The coefficient of variation was obtained by calculating the standard deviation and the average value.

<Ratio of metal nanowires with an aspect ratio of 10 or more>
Each silver nanowire aqueous dispersion is filtered to separate silver nanowires and other particles, and the amount of silver remaining on the filter paper using an ICP emission analyzer (ICPS-8000, manufactured by Shimadzu Corporation) The amount of silver that has passed through the filter paper is measured, and the ratio of metal nanowires having a minor axis length of 50 nm or less and a major axis length of 5 μm or more to an aspect ratio of 10 or more (% ).
The metal nanowires were separated when determining the ratio of the metal nanowires using a membrane filter (Millipore, FALP 02500, pore size 1.0 μm).

<Single degree of long axis length>
The single axis of the long axis length in the metal nanowire is measured in the range of ± 30% of the average long axis length by measuring the long axis length of an arbitrary 100 metal nanowires from a scanning electron microscope image. It calculated | required from the ratio (percentage) of the number of metal nanowires.

<Curvature radius>
The radius of curvature of the metal nanowire was obtained by approximating the nanowire of the scanning electron microscope image to an arc with a digitizer.

<Ratio of spherical or rod-like particles having a major axis length of 0.1 μm or less>
From the scanning electron microscope image, the number N of metal nanowires and the number R of spherical or rod-like particles having a major axis length of 0.1 μm or less were measured, and the ratio R / N (percentage) was obtained.

(Preparation Example 2)
-Preparation of silver nanowire dispersion (2)-
30 mL of ethylene glycol was placed in a three-necked flask and heated to 160 ° C. Thereafter, 36 mM polyvinylpyrrolidone (PVP K-55, manufactured by Aldrich), 3 μM acetylacetonate iron, 18 μL of 60 μM sodium chloride ethylene glycol solution and 18 mL of 24 mM silver nitrate ethylene glycol solution were added at a rate of 1 mL per minute. . The mixture was heated at 160 ° C. for 60 minutes and cooled to room temperature. Add water and centrifuge, purify until the conductivity is 50 μS / cm or less, further centrifuge with propylene glycol monomethyl ether to remove water, finally add propylene glycol monomethyl ether, silver nanowires Dispersion (2) was prepared.
Metal nanowires (silver nanowires) having an average minor axis length, average major axis length, coefficient of variation of minor axis length, and aspect ratio of 10 or more of silver nanowires in the obtained silver nanowire dispersion (2) The ratio of (wire) was measured in the same manner as in Preparation Example 1. The results are shown in Table 1.

(Preparation Example 3)
-Preparation of carbon nanotube (CNT) dispersion-
A single-walled carbon nanotube dispersion was prepared with reference to Example 1 of Japanese Patent No. 3903159.
Single-walled carbon nanotubes (synthesized based on Chemical Physics Letters, 323 (2000) P.580-P.585), polyoxyethylene-polyoxypropylene copolymer as a dispersant, isopropyl alcohol / water mixture as a solvent (Mixing ratio 5: 1). The content of single-walled carbon nanotubes was 0.003% by mass, and the content of dispersant was 0.05% by mass.
The average minor axis length of CNTs in the obtained CNT dispersion was 5 nm, and the average major axis length was 1 μm.

* In Table 1, “ratio of metal nanowires” represents the ratio of metal nanowires (silver nanowires) having an aspect ratio of 1000 or more.

Example 1
<Preparation of transparent conductive film (single layer)>
As shown below, the sample Nos. 101 to 112 transparent conductive films were prepared.

<Sample No. Production of 101>
-Formation 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 · min, and an undercoat layer coating solution having the following composition is applied. An undercoat layer of 8 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.

Next, the surface of the undercoat layer was subjected to a corona discharge treatment of 8 W / m ² · min, and hydroxyethyl cellulose was coated as a hydrophilic polymer layer so that the dry thickness was 0.2 μm.

  Next, the silver nanowire dispersion (1) is coated on the hydrophilic polymer layer with a single-wafer automatic coating machine (G-7 type, manufactured by Tester Sangyo Co., Ltd.), coating speed of 50 mm / min, coating liquid temperature. No. No. under conditions of 25 ° C. and glass substrate temperature 25 ° C. Bar coating was applied with a bar coater 2 to form a conductive layer having a thickness of 0.1 μm. As described above, the sample No. A transparent conductive film 101 was prepared.

<Sample No. Production of 102>
Sample No. 101, the silver nanowire dispersion (1) was placed on the hydrophilic polymer layer, and the number of the bar coater was changed to No. 101. Sample no. In the same manner as in Sample 101, Sample No. A transparent conductive film 102 was produced.

<Sample No. Production of 103>
Sample No. 101, the silver nanowire dispersion (1) was placed on the hydrophilic polymer layer, and the number of the bar coater was changed to No. 101. Sample No. 14 was changed to bar No. 14 except that bar coating was applied. In the same manner as in Sample 101, Sample No. A transparent conductive film 103 was prepared.

<Sample No. Production of 104>
Sample No. 101, the silver nanowire dispersion (1) was placed on the hydrophilic polymer layer, and the number of the bar coater was changed to No. 101. Sample No. was changed except that bar coating was applied instead of 60. In the same manner as in Sample 101, Sample No. 104 transparent conductive films were prepared.

<Sample No. Production of 105>
Sample No. 101, except that the silver nanowire dispersion (1) was diluted with water three times on the hydrophilic polymer layer and bar-coated. In the same manner as in Sample 101, Sample No. 105 transparent conductive films were prepared.

<Sample No. Production of 106>
Sample No. 101, the silver nanowire dispersion (1) was placed on the hydrophilic polymer layer, and the number of the bar coater was changed to No. 101. Sample No. 7 except that bar coating was applied instead of 75. In the same manner as in Sample 101, Sample No. 106 transparent conductive films were prepared.

<Sample No. Production of 107>
Sample No. 101, the silver nanowire dispersion (1) was changed to the silver nanowire dispersion (2) on the hydrophilic polymer layer, and the count No. Sample No. 2 except that bar coating was applied with the bar coater of No. 2. In the same manner as in Sample 101, Sample No. 107 transparent conductive films were produced.

<Sample No. Production of 108>
Sample No. In No. 107, the silver nanowire dispersion (2) was placed on the hydrophilic polymer layer, and the number of the bar coater was No. 107. Sample no. In the same manner as in Sample 101, Sample No. 108 transparent conductive films were prepared.

<Sample No. Production of 109>
Sample No. 101, the silver nanowire dispersion (2) was placed on the hydrophilic polymer layer, and the number of the bar coater was No. 101. Sample No. 4 was changed to bar 14 except that bar coating was applied. In the same manner as in Sample 101, Sample No. 109 transparent conductive films were produced.

<Sample No. Production of 110>
Sample No. 101, the silver nanowire dispersion (2) was placed on the hydrophilic polymer layer, and the number of the bar coater was No. 101. Sample No. was changed except that bar coating was applied instead of 60. In the same manner as in Sample 101, Sample No. 110 transparent conductive films were produced.

<Sample No. Production of 111>
Sample No. 101, the CNT dispersion was changed to the silver nanowire dispersion (1) on the hydrophilic polymer layer, and the count No. Sample no. In the same manner as in Sample 101, Sample No. A transparent conductive film 111 was prepared.

<Sample No. Production of 112>
Sample No. 101, the CNT dispersion was placed on the hydrophilic polymer layer, and the number of the bar coater was changed to No. 101. Sample no. In the same manner as in Sample 101, Sample No. 112 transparent conductive films were produced.

  Next, the produced sample No. 101-No. About the transparent conductive film of 112, various characteristics were evaluated as follows. The results are shown in Table 2.

<Number of intersections>
Observation with a scanning electron microscope (SEM, manufactured by Hitachi, Ltd., S-2300) from the direction perpendicular to the surface of the conductive layer of each transparent conductive film obtained, one metal nanowire as a measurement target is another metal nanowire. The number of intersections overlapping with the wires was determined by obtaining 10 intersections per 1 μm, avoiding overlapping on the metal nanowires, and obtaining the average thereof to measure the number of intersections.

<Intersection angle>
Measure the crossing angle by using a protractor on the acute angle side of the angle formed by the straight line at the intersection of two metal nanowires in the scanning electron microscope image or the tangent line if curved. did. In addition, a measured value is an average value of 20 places.

<Measurement of transmittance>
About the obtained conductive layer of each transparent conductive film, the transmittance | permeability of 400 nm-800 nm was measured using Shimadzu UV-2550.

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

<Evaluation of black tightening>
For the evaluation of black tightening, a glass substrate coated with metal nanowires was placed on black paper, and sensory evaluation was performed visually. Evaluation was performed in a dark room so that reflection of external light and illumination did not occur, and the illumination was adjusted so that the glass surface was 500 lux. The evaluation criteria are as follows, and the most frequent evaluation among the evaluations by five panelists was the evaluation of black tightening of the sample.
〔Evaluation criteria〕
A: Good with almost no change in black compared to uncoated glass.
○: Black is slightly insufficient with respect to uncoated glass, but it is good because it is not felt alone.
(Triangle | delta): Even if it is a single substance, the shortage of blackness is felt, but it is an acceptable grade.
X: Black is insufficient and unacceptable.

(Example 2)
-Production of transparent conductive film (two-layer lamination)-
As shown below, the sample Nos. 201-No. 212 transparent conductive films were produced.

<Sample No. Production of 201>
-Formation 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 · min, and an undercoat layer coating solution having the following composition is applied. An undercoat layer of 8 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.

Next, the surface of the undercoat layer was subjected to a corona discharge treatment of 8 W / m ² · min, and hydroxyethyl cellulose was coated as a hydrophilic polymer layer so that the dry thickness was 0.2 μm.

Next, the silver nanowire dispersion (1) is coated on the hydrophilic polymer layer with a single wafer automatic coating machine (G-7 type, manufactured by Tester Sangyo Co., Ltd.), coating speed of 120 mm / min, coating liquid temperature. A first bar coating was applied at 35 ° C. and a glass substrate temperature of 35 ° C. to form a first conductive layer having a thickness of 0.1 μm.
Next, a second bar coat application in which the silver nanowire dispersion (1) is changed to a coating direction of 45 degrees with respect to the application direction of the first bar coat application on the first conductive layer. A second conductive layer having a thickness of 0.1 μm was formed in the same manner as in the first bar coat application except for the above. As described above, the sample No. 201 transparent conductive films were produced.

<Sample No. Production of 202>
Sample No. In 201, the second bar coat application was changed to the application direction of 60 degrees with respect to the application direction of the first bar coat application. In the same manner as in Sample No. 201, Sample No. 202 transparent conductive films were produced.

<Sample No. Production of 203>
Sample No. In sample 201, the second bar coat application was changed to an application direction of 75 degrees with respect to the application direction of the first bar coat application. In the same manner as in Sample No. 201, Sample No. 203 transparent conductive films were produced.

<Sample No. Production of 204>
Sample No. In No. 201, sample No. 2 was changed except that the second bar coat application was changed to 90 ° application direction with respect to the application direction of the first bar coat application. In the same manner as in Sample No. 201, Sample No. 204 transparent conductive films were produced.

<Sample No. Production of 205>
Sample No. In sample 201, the second bar coat application was changed to the application direction of 40 degrees with respect to the application direction of the first bar coat application. In the same manner as in Sample No. 201, Sample No. 205 transparent conductive films were produced.

<Sample No. Production of 206>
Sample No. In sample No. 201, the second bar coat application was changed to an application direction of 10 degrees with respect to the application direction of the first bar coat application. In the same manner as in Sample No. 201, Sample No. 206 transparent conductive films were prepared.

<Sample No. Production of 207>
Sample No. In Sample No. 201, except that the silver nanowire dispersion (1) was replaced with the silver nanowire dispersion (2). In the same manner as in Sample No. 201, Sample No. A transparent conductive film 207 was produced.

<Sample No. Production of 208>
Sample No. In sample No. 202, except that the silver nanowire dispersion (1) was replaced with the silver nanowire dispersion (2). In the same manner as in 202, sample no. 208 transparent conductive films were prepared.

<Sample No. Production of 209>
Sample No. No. 203, except that the silver nanowire dispersion (1) was replaced with the silver nanowire dispersion (2). In the same manner as in sample No. 203, sample no. A transparent conductive film 209 was prepared.

<Sample No. Production of 210>
Sample No. 204, except that the silver nanowire dispersion (1) was replaced with the silver nanowire dispersion (2). In the same manner as in sample No. 204, sample no. 210 transparent conductive films were produced.

<Sample No. Production of 211>
Sample No. In sample No. 205, except that the silver nanowire dispersion (1) was replaced with the silver nanowire dispersion (2). In the same manner as sample 205, sample no. 211 transparent conductive films were produced.

<Sample No. Production of 212>
Sample No. 206, except that the silver nanowire dispersion (1) was replaced with the silver nanowire dispersion (2). In the same manner as in Sample No. 206, Sample No. 212 transparent conductive films were produced.

  Next, the produced sample No. 201-No. For the transparent conductive film No. 212, Sample No. 101-No. In the same manner as 112, various characteristics were evaluated. The results are shown in Table 3.

(Example 3)
-Solvent cleaning, alkali cleaning, or heat treatment-
Sample No. 1 of Example 1 103 and sample no. Samples prepared in the same manner as in 104 were subjected to solvent washing, alkali washing, and heating post-treatment as shown in Table 4 below. In the solvent cleaning, an aqueous ethanol solution (95% by mass) or an aqueous propanol solution (80% by mass) was immersed at 25 ° C. for 20 seconds and dried at 40 ° C. In alkali cleaning, a 0.1N sodium hydroxide aqueous solution was immersed for 20 seconds at 25 ° C. and dried at 40 ° C. The heat treatment was performed by adhering to a hot plate at 110 ° C. for 1 minute. The water immersion was performed at 25 ° C. for 30 seconds.
Next, the produced sample No. 301-No. With respect to the transparent conductive film 310, Sample No. 101-No. In the same manner as 112, various characteristics were evaluated. The results are shown in Table 4.

From the results in Table 4, sample No. Sample no. 301-No. 306, and sample no. Sample no. 307-No. It can be seen that 310 is a more preferable embodiment of the present invention because the surface resistance is lower than that of water immersion after post-treatment, and the transmittance and blackening are improved.

Example 4
-Fabrication of touch panel-
Sample No. Using the 305 transparent conductive film, “Latest Touch Panel Technology” (issued July 6, 2009, Techno Times Co., Ltd.), supervised by Yuji Mitani, “Technology and Development of Touch Panel”, CM Publishing (December 2004) ), “FPD International 2009 Forum T-11 Lecture Textbook”, “Cypress Semiconductor Corporation Application Note AN2292” and the like, and the touch panel was manufactured.
When using the manufactured touch panel, it improves visibility by improving transmittance, and responds to input of characters, etc. or screen operations with at least one of bare hands, hands with gloves, or pointing tools by improving conductivity It was found that a touch panel with excellent performance can be produced. The touch panel includes a so-called touch sensor and a touch pad.

(Example 5)
<Production of integrated solar cell>
-Fabrication of amorphous solar cells (super straight type)-
On the glass substrate, the sample No. A transparent conductive film 304 was formed. A p-type film having a thickness of 15 nm was formed on the transparent conductive film by plasma CVD, an i-type film having a thickness of 350 nm was formed on the p-type film, and an n-type amorphous silicon film having a thickness of 30 nm was formed on the i-type film. A gallium-doped zinc oxide layer having a thickness of 20 nm was formed as a back surface reflecting electrode on the n-type amorphous silicon, and a silver layer having a thickness of 200 nm was formed on the gallium-doped zinc oxide layer to produce a photoelectric conversion element.

(Example 6)
<Production of integrated solar cell>
-Fabrication of CIGS solar cells (substrate type)-
A molybdenum electrode having a thickness of about 500 nm by a DC magnetron sputtering method on a glass substrate, and Cu (In _0.6 Ga _0.4) which is a chalcopyrite semiconductor material having a thickness of 2.5 μm by a vacuum deposition method on the electrode. ) A cadmium sulfide thin film having a thickness of 50 nm was formed on the Se ₂ thin film and the Cu (In _0.6 Ga _0.4 ) Se ₂ thin film by a solution deposition method. On top of the cadmium sulfide thin film, a sample No. A transparent conductive film 104 was formed, and a boron-added zinc oxide thin film (transparent conductive layer) having a thickness of 100 nm was formed on the transparent conductive film by a direct current magnetron sputtering method to produce a photoelectric conversion element.

<Evaluation of solar cell characteristics (conversion efficiency)>
About the produced solar cell of Example 5 and 6, the solar cell characteristic (conversion efficiency) was measured by irradiating the artificial sunlight of AM1.5 and 100 mW / cm < ² >. The results are shown in Table 5.

  The conductive film of the present invention has small light scattering, good black tightening, high transmittance up to a long wavelength region, high conductivity, and improved light resistance and migration resistance. It can be widely used for touch panels, antistatics for displays, electromagnetic shielding, electrodes for organic EL displays, electrodes for inorganic EL displays, electronic paper, electrodes for flexible displays, antistatics for flexible displays, solar cells, and other various devices. .

10, 20, 30 Touch panel 11, 21, 31 Transparent substrate 12, 13, 22, 23, 32, 33 Transparent conductive film 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 101 display 102 transparent adhesive 103 second electrode 104 transparent substrate 105 first electrode 106 transparent adhesive 107 transparent film 108 hard coat layer 109 antireflection layer 110 protective resin layer 120 reflection Prevention film 130 Touch panel

Claims (10)

A conductive film containing at least metal nanowires having an average minor axis length of 50 nm or less and an average major axis length of 5 μm or more,
When observed with a scanning electron microscope from a direction perpendicular to the surface of the conductive film, the number of intersections where one metal nanowire to be measured overlaps with another metal nanowire is the number of intersections of the one metal nanowire. 2. A conductive film characterized in that the number is 2 to 200 per 1 μm. A conductive film containing at least metal nanowires having an average minor axis length of 50 nm or less and an average major axis length of 5 μm or more,
When observed with a scanning electron microscope from the direction perpendicular to the surface of the conductive film, the crossing angle on the narrow angle side at the intersection where one metal nanowire to be measured overlaps another metal nanowire is an average value. A conductive film which is greater than or equal to 50 degrees and less than 90 degrees.   The conductive film according to claim 1, wherein the metal nanowire has an average minor axis length of 15 nm to 35 nm.   The electrically conductive film according to any one of claims 1 to 3, wherein the metal nanowire is made of any of silver and an alloy of silver and a metal other than silver.   The conductive film according to claim 1, wherein the metal nanowire has a radius of curvature of 100 μm to 1,000 μm.   The conductive film according to any one of claims 1 to 5, wherein a ratio of spherical or rod-like particles having a major axis length of 0.1 µm or less is 10% or less. At least a conductive layer forming step of forming a conductive layer by applying a conductive layer composition containing at least metal nanowires on a support,
In the conductive layer forming step, the conductive layer composition is applied by bar coating, and is applied twice or more by changing the application direction.   The manufacturing method of the electrically conductive film of Claim 7 including the washing | cleaning process of wash | cleaning a conductive layer with at least any one of an organic solvent and an alkaline solution.   The manufacturing method of the electrically conductive film in any one of Claim 7 to 8 including the heating process which heats a conductive layer to 100 degreeC or more.   A touch panel or an integrated solar cell using the conductive film according to claim 1.