JP2011222298A - Conductive film and method of producing the same, and touch panel and integrated solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a conductive film in which a fine pattern of a high permeability low resistance conductive film can be formed easily while improving insulation significantly, and to provide a touch panel in which durability against writing pressure and flexibility are improved, and an integrated solar cell in which conversion efficiency is improved.SOLUTION: A conductive film consists of a substrate, and a conductive layer formed on the substrate and containing at least conductive fibers. The conductive layer is patterned and the pattern edge roughness is 5 μm or less. Such an aspect as the conductive layer contains dispersant and the mass ratio (A/B) of the total content A of the dispersant and the content B of conductive fibers is 0.1 to 5.0, or an aspect as the conductive fibers have an average short-axis length of 100 nm or less and an average long-axis length of 5 μm or more is preferable.

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, studies have been made on improving the absorption of light having a long wavelength. At this time, light absorption (light transmittance) of the transparent electrode, which plays a role for taking out the solar cell as electric energy, is also important.

  In general, ITO (indium tin oxide) and zinc oxide, which are used as transparent electrodes for solar cells, are mainly applied with N-type dopants to impart conductivity, but increasing the doping amount to increase conductivity There is a problem that the transmittance of long wavelength is 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 improvement. 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, this is still insufficient, and further improvement in transmittance is desired. On the other hand, ITO is widely used as a transparent conductive material in touch panels, which have been rapidly demanded in recent years due to the spread of portable game machines and the like. However, as described above, pen pressure durability has been a problem as a color caused by low transmittance in the long wavelength region and a problem peculiar to the touch panel.

  In order to solve the above problems, for example, a transparent conductive film containing silver nanowires has been proposed (see Patent Document 1). This proposal is excellent in terms of transparency, low resistance, and reduction of the amount of metal used, but synthesis at high temperatures using an organic solvent is common. Due to the diameter of the silver nanowires generated, the haze is high, the contrast is significantly reduced, and practical durability is obtained unless a coating such as a photo-curing resin is applied to the outermost air layer. However, there is a problem that the resistance is increased by the coating and the uniformity of the in-plane resistance is lowered, and further improvement is desired.

On the other hand, patterned transparent conductive films are used in many parts such as display elements and solar cell electrodes. In general, a patterned transparent conductive film is formed by indium tin oxide (ITO) or zinc oxide exclusively by a dry process such as vapor deposition or sputtering because of required characteristics, mainly conductivity, transparency, and patterning characteristics. Thereafter, dry etching such as plasma, or a positive / negative resist is used together to produce a transparent conductive pattern (see Patent Documents 2 and 3).
However, in this manufacturing method, in order to form a transparent conductive pattern, a large number of processes such as resist coating and development, etching of the conductive film, etc., large-scale equipment that requires vacuum, and multistage chemical treatment are indispensable. In addition to the further improvement of the final performance, the simplification of the process is strongly desired from the viewpoint of the recent environment and energy.

For these problems, a transparent conductive film patterned by a relatively simple method by arranging a conductive layer containing conductive fibers such as silver nanowires in the same or different layer as the dispersion medium and patterning it by photolithography. A method for obtaining a film has been proposed (see Patent Document 4).
However, as a result of investigations by the present inventors, when a conductive layer containing conductive fibers such as silver nanowires is patterned by photolithography, silver nanowires protruding from the pattern edge partially remain in the vicinity of the pattern edge. I discovered a new problem that pattern quality deteriorates. In particular, the present inventors have found a new problem that it is difficult to arrange a conductive pattern with a narrow space interval when silver nanowire portions protruding from the pattern edge come into contact with each other.

  Therefore, a conductive film that can remarkably improve insulation, has high permeability, low resistance, and has improved flexibility, and a method for manufacturing a conductive film that can easily form fine patterns, as well as writing pressure durability and flexibility. Under the present circumstances, it is desired to promptly provide a touch panel with improved performance and an integrated solar cell with improved conversion efficiency.

US Patent Application Publication No. 2007/0074316 JP 2010-21137 A JP 2009-503825 A US Patent Application Publication No. 2008/0292979

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention can significantly improve insulation, high permeability, low resistance, improved flexibility, a method for producing a conductive film that can easily form fine patterns, and writing pressure durability. An object of the present invention is to provide a touch panel with improved properties and flexibility and an integrated solar cell with improved conversion efficiency.

In order to solve the above problems, when the present inventors patterned by photolithography, the conductive fiber protruding from the pattern edge partially remains in the vicinity of the pattern edge. As a result of intensive studies to solve the new problem that it becomes difficult to arrange conductive patterns at narrow space intervals due to contact of the wire part protruding from the pattern edge, It can be considered to be removed by etching using a chemical or the like, but it is a thin layer in order to achieve both high transparency and high conductivity, and a conductive film in which a conductive layer is arranged with a small dispersion medium. When applied, the conductive fibers in the pattern part are also removed by the drug, and the exposed conductive material It was found that is possible to selectively remove the Wei only is difficult.
Therefore, as a result of further intensive studies on the method for selectively removing the conductive fibers protruding from the pattern edge, the present inventors preferably (1) surprisingly (1) patterned conductive film in the liquid. Immersed and irradiated with ultrasonic waves, or (2) By bringing the patterned conductive film into contact with a halide ion-containing solution, the pattern edge roughness becomes 5 μm or less, and a fine pattern can be easily formed and highly transparent. It was found that the property and conductivity can be secured.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A substrate and a conductive layer containing at least conductive fibers on the substrate;
The conductive layer is patterned, and has a pattern edge roughness of 5 μm or less.
<2> The conductive layer contains a dispersion medium, and the mass ratio (A / B) between the total content A of the dispersion medium and the content B of the conductive fibers is 0.1 to 5.0 <1>.
<3> The conductive film according to any one of <1> to <2>, wherein the conductive fiber has an average minor axis length of 100 nm or less and an average major axis length of 5 μm or more.
<4> The conductive film according to any one of <1> to <3>, wherein the conductive fiber is a metal nanowire.
<5> The conductive film according to <4>, wherein the metal nanowire contains silver.
<6> The conductive film according to any one of <1> to <5>, wherein the light transmittance is 70% or more.
<7> The conductive film according to any one of <1> to <6>, wherein the surface resistance is 0.1Ω / □ to 10,000Ω / □.
<8> a first patterning step of forming a pattern on the conductive layer in the conductive film having a conductive layer containing at least conductive fibers on the substrate;
A second patterning step of removing conductive fibers protruding from the edges of the formed pattern;
It is a manufacturing method of the electrically conductive film characterized by including.
<9> The method for producing a conductive film according to <8>, wherein the second patterning step is performed by immersing the conductive film patterned in the first patterning step in a liquid and irradiating with ultrasonic waves. .
<10> The above <8> to <9, wherein the conductive fiber contains silver, and the second patterning step is performed by bringing the conductive film patterned in the first patterning step into contact with the halide ion-containing solution. > A method for producing a conductive film according to any one of the above.
<11> The conductive layer contains a photosensitive compound,
The method for producing a conductive film according to any one of <8> to <10>, wherein the first patterning step is performed by exposing and developing the conductive layer.
<12> A photosensitive layer is provided on either the surface of the conductive layer on the substrate side or the surface of the conductive layer that does not have the substrate.
The method for producing a conductive film according to any one of <8> to <10>, wherein the first patterning step is performed by exposing the photosensitive layer and developing the photosensitive layer and the conductive layer. .
<13> A touch panel using the conductive film according to any one of <1> to <7>.
<14> An integrated solar cell using the conductive film according to any one of <1> to <7>.

  According to the present invention, conventional problems can be solved, insulating properties can be remarkably improved, conductive properties with high permeability, low resistance, improved flexibility, and conductive properties that can easily form fine patterns. A film manufacturing method, a touch panel with improved writing pressure durability and flexibility, and an integrated solar cell with improved conversion efficiency can be provided.

FIG. 1 is a schematic view of a conductive pattern after patterning viewed from above for explaining how to obtain pattern edge roughness. 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. FIG. It is a photograph which shows the observation result by the digital microscope of 1-1. FIG. It is a photograph which shows the observation result by the digital microscope of 1-2. FIG. It is a photograph which shows the observation result by the digital microscope of 1-12. 9 shows a sample No. with a finer exposure pattern. It is a photograph which shows the observation result by the digital microscope of 1-1. 10 shows a sample No. with a finer exposure pattern. It is a photograph which shows the observation result by the digital microscope of 1-2.

(Conductive film)
The conductive film of the present invention comprises a base material and a conductive layer containing at least conductive fibers on the base material, and contains a photosensitive layer and, if necessary, other components.

In the present invention, the conductive layer is patterned, and the type of the pattern is not particularly limited and can be appropriately selected according to the purpose. For example, characters, symbols, patterns, figures, wiring patterns , Etc.
There is no restriction | limiting in particular as a magnitude | size of the said pattern, Although it can select suitably according to the objective, Any magnitude | size from nano size to centimeter size may be sufficient.

The pattern edge roughness in the pattern of the conductive layer is 5 μm or less, preferably 3 μm or less, and more preferably 1 μm or less. When the pattern edge roughness exceeds 5 μm, the conductive patterns having a narrow space interval are in contact with each other and short-circuited electrically, or the conductive fibers in the portion protruding from the pattern edge are deteriorated, resulting in problems such as coloring. May occur.
Here, the pattern edge roughness is obtained by extracting an edge region including an average line of pattern edges over a length of 100 μm and dividing it into 10 sections so that each section includes an average line length of 10 μm. The maximum width of the distance is obtained from the average line, the average value of the maximum widths up to the fifth highest among the obtained maximum widths of each section is calculated, and this is defined as the pattern edge roughness. However, when the total length of the average line of the pattern edge is less than 100 μm, the pattern edge region is equally divided into 10 along the average line, and the maximum width from the average line is obtained in each section. The average value of the maximum widths from the maximum width to the fifth highest is defined as the pattern edge roughness.
FIG. 1 is a schematic view of a conductive pattern after patterning viewed from above for explaining how to obtain pattern edge roughness. In FIG. 1, the pattern edge is divided into regions including an average line length of 10 μm along the average line, and the maximum width of the distance from the average line is obtained in each section (W1, W2, W3 in FIG. 1). This operation is performed over 10 sections, and an average value of values up to the top five is obtained from the maximum width of the distance from the average line from W1 to W10, and this is used as the pattern edge roughness. Although FIG. 1 illustrates the case where the average line is a straight line, the same applies to the case where the average line is a curve.
There is no restriction | limiting in particular as a method of calculating | requiring the distance from the said average line, According to the objective, it can select suitably, For example, it calculates | requires by observation, such as an optical microscope, a digital microscope, or a scanning electron microscope (SEM). Can do.

  The phenomenon that the pattern edge shape of the conductive layer becomes rough rather than flat as shown in FIG. 1 is a case where patterning is performed by negative photolithography. This is probably because part of the dispersion medium and the conductive fibers remained after development. The reason for this is considered as follows, including estimation. That is, if conductive fibers exist across the exposed and unexposed areas, the conductive fibers are partially fixed to the dispersion medium in the exposed area and cannot be eluted during development. The fiber remains including the part that protrudes from the unexposed part. In addition, if conductive fibers protrude from the unexposed areas, the elution efficiency in development decreases due to adsorption of the unexposed areas of the surrounding exposed fibers to the conductive fibers, etc. Part of it will remain. Thus, when patterning by photolithography is performed on a material containing a fibrous material, the pattern edge is considered to have a rough shape deviating from the exposure pattern. This problem is related to patterning methods other than negative photolithography, such as positive photolithography, ablation by partial irradiation of heat, electromagnetic waves, electron beams, etc. or patterning that removes a dispersion medium by partial irradiation of particles, fluids, etc. In the system, it is considered that the fibrous material can be generated in the same manner as it exists across the pattern boundary.

<Conductive layer>
The conductive layer contains at least conductive fibers, and contains a dispersion medium and, if necessary, other components.

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

-Metal nanowires-
The material of the metal nanowire is not particularly limited. For example, at least one metal selected from the group consisting of the fourth period, the fifth period, and the sixth period of the long periodic table (IUPAC 1991) is preferable. At least one metal selected from Group 2 to Group 14 is more preferable, and Group 2, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13, and Group 14 are more preferable. At least one metal selected from the group is more preferable, and it is particularly preferable to include it 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. And alloys thereof. Among these, silver and an alloy with silver are preferable in terms of excellent conductivity.
Examples of the metal used in the alloy with silver include platinum, osmium, palladium and iridium. These may be used alone or in combination of two or more.

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).

The average minor axis length of the metal nanowire (sometimes referred to as “average minor axis diameter” or “average diameter”) is preferably 100 nm or less, more preferably 5 nm to 45 nm, and more preferably 10 nm to 40 nm. Further preferred is 15 nm to 35 nm.
When the average minor axis length is less than 5 nm, the oxidation resistance may be deteriorated and the durability may be deteriorated. When the average minor axis length is more than 100 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 nanowire is preferably 5 μm or more, more preferably 5 μm to 40 μm, and even more preferably 5 μm to 30 μm.
If the average major axis length is less than 5 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.

  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 reduced, heating in the solvent which melt | dissolved the halogen compound and the dispersion additive as follows. It is preferable to manufacture by.

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

As heating temperature at the time of the said heating, 250 degrees C or less is preferable, 20 to 200 degreeC is more preferable, 30 to 180 degreeC is more preferable, 40 to 170 degreeC is still more preferable.
If the heating temperature is less than 20 ° C., the lower the heating temperature, the lower the nucleation probability, and the metal nanowires become too long, so the metal nanowires are likely to be entangled, and the dispersion stability may deteriorate. When it exceeds 250 ° C., the corner of the cross section of the metal nanowire becomes steep, and the transmittance in the evaluation of the coating film may be lowered.
If necessary, the temperature may be changed during the formation process of the metal nanowires. By changing the temperature during the process, the nucleation of the metal nanowires is controlled, the renucleation is suppressed, and the monodispersity is improved by promoting selective growth. The 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, methylcellulose, hydroxypropylcellulose, polyalkyleneamine, partial alkyl ester of polyacrylic acid, polyvinylpyrrolidone, and polyvinylpyrrolidone copolymer are preferable.
For the structure that can be used as the dispersion additive, for example, the description of “Encyclopedia of Pigments” (edited by Seijiro Ito, published by Asakura Shoin Co., Ltd., 2000) can be referred to.
Moreover, the shape of the metal nanowire obtained can also be changed with the kind of dispersion additive to be used.

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

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

  The dispersion additive and the halogen compound or the silver halide fine particles may be used in the same substance. Examples of the compound in which the dispersion additive and the halogen compound are used in combination include, for example, HTAB (hexadecyl-trimethylammonium bromide) containing an amino group and a bromide ion, and HTAC (hexadecyl-trimethylammonium chloride) containing an amino group and a chloride ion. Etc.

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

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

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

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

  There is no restriction | limiting in particular as a manufacturing method of the said metal nanotube, You may manufacture by what kind of method, For example, the well-known method etc. which are described in the US application publication 2005/0056118 grade | etc., Etc. can be used.

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

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

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

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

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

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

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

<< dispersion medium >>
In the present invention, the dispersion medium means all components other than the conductive fibers of the conductive layer. The mass ratio (A / B) of the total content A (in the case of only one kind) of the dispersion medium in the conductive layer and the content B of the conductive fibers is 0.1 to 5. 0 is preferable, and 0.5 to 3.0 is more preferable. When the mass ratio (A / B) is less than 0.1, deterioration of optical properties such as conductivity, transmittance and haze due to aggregation of conductive fibers, mechanical strength of the conductive layer, and adhesion to the substrate. Deterioration, particularly the quality of the pattern obtained by the first patterning using photolithography (faithful reproducibility of the exposure pattern) may occur. When the mass ratio (A / B) exceeds 5.0, there may be a decrease in conductivity due to a decrease in the number of contact points between the conductive fibers, and deterioration of optical characteristics such as haze and light transmittance.

  In the present invention, the dispersion medium preferably contains a compound that imparts the function of forming an image by exposure to the conductive layer, or a compound that gives the trigger thereof. Specifically, (1) a compound that generates an acid by exposure ( Photoacid generators), (2) photosensitive quinonediazide compounds, and (3) photoradical generators. These may be used individually by 1 type and may use 2 or more types together. Moreover, a sensitizer etc. can also be used together for sensitivity adjustment. In addition to these components, various additives such as polymers, monomers, dispersants, solvents, crosslinking agents, surfactants, antioxidants, antioxidants, metal corrosion inhibitors, viscosity modifiers, preservatives, and the like described below. Etc. These components may be appropriately contained as necessary.

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

  Examples of the (1) photoacid generator include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates. Among these, imide sulfonate, oxime sulfonate, and o-nitrobenzyl sulfonate, which are compounds that generate sulfonic acid, are particularly preferable.

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

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

  Examples of the 1,2-quinonediazide sulfonyl chlorides include benzoquinone-1,2-diazide-4-sulfonyl chloride, naphthoquinone-1,2-diazide-5-sulfonyl chloride, and naphthoquinone-1,2-diazide-4- And sulfonyl chloride. Among these, naphthoquinone-1,2-diazide-4-sulfonyl chloride is particularly preferable in terms of sensitivity.

  Examples of the hydroxy compound include hydroquinone, resorcinol, pyrogallol, bisphenol A, bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, and 2,3,4-trihydroxybenzophenone. 2,3,4,4′-tetrahydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3,4,2 ′, 3′-pentahydroxybenzophenone, 2,3,4, 3 ′, 4 ′, 5′-hexahydroxybenzophenone, bis (2,3,4-trihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) propane, 4b, 5,9b, 10-tetrahydro -1,3,6,8-tetrahydroxy-5,10-dimethylindeno [2, -A] indene, tris (4-hydroxyphenyl) methane, tris (4-hydroxyphenyl) ethane, 4,4 '-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl ] -Ethylidene] bisphenol, and the like.

  Examples of the amino compound include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, and 4,4′-diaminodiphenyl. Sulfide, o-aminophenol, m-aminophenol, p-aminophenol, 3,3′-diamino 4,4′-dihydroxybiphenyl, 4,4′-diamino 3,3′-dihydroxybiphenyl, bis (3-amino 4-hydroxyphenyl) propane, bis (4-amino3-hydroxyphenyl) propane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino3-hydroxyphenyl) sulfone, bis (3-amino-4- Hydroxyphenyl) hexafluoropropane Bis (4-amino-3-hydroxyphenyl) hexafluoropropane, and the like.

  The 1,2-quinonediazide sulfonyl chloride and the hydroxy compound and / or amino compound are blended so that the total of the hydroxy group and the amino group is 0.5 to 1 equivalent with respect to 1 mol of 1,2-quinonediazide sulfonyl chloride. It is preferred that A preferred ratio of the dehydrochlorinating agent and o-quinonediazide sulfonyl chloride is in the range of 1/1 to 1 / 0.9. A preferable reaction temperature is 0 ° C. to 40 ° C., and a preferable reaction time is 1 to 24 hours.

Examples of the reaction solvent include dioxane, 1,3-dioxolane, acetone, methyl ethyl ketone, tetrahydrofuran, chloroform, N-methylpyrrolidone, and γ-butyrolactone.
Examples of the dehydrochlorination agent include sodium carbonate, sodium hydroxide, sodium hydrogen carbonate, potassium carbonate, potassium hydroxide, trimethylamine, triethylamine, pyridine, 4-dimethylaminopyridine and the like.

As said quinonediazide compound, the compound which has the following structures can be mentioned, for example.
However, in said formula, D is independently either a hydrogen atom or the following substituents.

  However, at least 1 D should just be said quinonediazide group in each compound.

The blending amount of the (1) photoacid generator and the (2) quinonediazide compound is set to 100 parts by mass of the total amount of polymer to be described later in terms of the difference in dissolution rate between the exposed part and the unexposed part and the allowable range of sensitivity. On the other hand, 1 mass part-100 mass parts are preferable, and 3 mass parts-80 mass parts are more preferable.
The (1) photoacid generator and the (2) quinonediazide compound may be used in combination.

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

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

-(3) Photoradical generator-
In the conductive layer, a photo radical generator having a function of generating a polymerization active radical by directly absorbing light or being photosensitized to cause a decomposition reaction or a hydrogen abstraction reaction can be used as a dispersion medium. The photoradical generator preferably has absorption in a wavelength region of 300 nm to 500 nm.

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

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

  Examples of the triazine compound include 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) -4,6-bis (trichloromethyl)- s-triazine, 2- (4-ethoxynaphthyl) -4,6-bis (todichloromethyl) mono-s-triazine, 2- (4-ethoxycarbonylnaphthyl) -4,6-bis (trichloromethyl) -s- Triazine, 2,4,6-tris (monochloromethyl) -s-triazine, 2,4,6-tris (dichloromethyl) -s-triazine, 2,4,6-tris (trichloromethyl) -s-triazine, 2-methyl-4,6-bis (trichloromethyl) -s-triazine, 2-n-propyl-4,6-bis (trichloromethyl) -s-triazine, 2 (Α, α, β-trichloroethyl) -4,6-bis (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) ) -4,6-bis (trichloromethyl) -s-triazine, 2- (3,4-epoxyphenyl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (p-chlorophenyl) -4 , 6-Bis (trichloromethyl) -s-triazine, 2- [1- (p-methoxyphenyl) -2,4-butadienyl] -4,6-bis (trichloromethyl) -s-triazine, 2-styryl- 4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (pi-propyl) Xystyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-natoxynaphthyl) -4,6 -Bis (trichloromethyl) -s-triazine, 2-phenylthio-4,6-bis (trichloromethyl) -s-triazine, 2-benzylthio-4,6-bis (trichloromethyl) -s-triazine, 4- ( o-bromo-pN, N- (diethoxycarbonylamino) -phenyl) -2,6-di (trichloromethyl) -s-triazine, 2,4,6-tris (dibromomethyl) -s-triazine, 2,4,6-tris (tribromomethyl) -s-triazine, 2-methyl-4,6-bis (tribromomethyl) -s-triazine, 2-methoxy-4,6 -Bis (tribromomethyl) -s-triazine, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the benzophenone compounds include benzophenone, Michler's ketone, 2-methylbenzophenone, 3-methylbenzophenone, N, N-diethylaminobenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophenone, and the like. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the acetophenone compound include 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4. -(4-morpholinyl) phenyl] -1-butanone, 1-hydroxycyclohexyl phenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1-methylethyl (p-isopropylphenyl) ketone, 1-hydroxy -1- (p-dodecylphenyl) ketone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 1,1,1-trichloromethyl- (p-butylphenyl) ketone 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butano -1 and the like. Specific examples of commercially available products are Irgacure 369, Irgacure 379, and Irgacure 907 manufactured by Ciba Specialty Chemicals. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the imidazole compound include JP-B-6-29285, US Pat. No. 3,479,185, US Pat. No. 4,311,783, and US Pat. No. 4,622,286. Various compounds described in the literature, specifically 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-bromo) Phenyl)) 4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2 '-Bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biidazole, 2,2'-bis (o, o'-dichlorophenyl) -4,4 ', 5 5'-tetraphenylbi Midazole, 2,2′-bis (o-nitrophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5 5'-tetraphenylbiimidazole, 2,2'-bis (o-trifluorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, and the like.

  Examples of the oxime compound include J.I. C. S. Perkin II (1979) 1653-1660), J. MoI. C. S. Perkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, Japanese Patent Application Laid-Open No. 2000-66385, Japanese Patent Application Laid-Open No. 2000-80068, Japanese Patent Application Publication No. 2004-534797 Compounds and the like. Specific examples include Irgacure OXE-01 and OXE-02 manufactured by Ciba Specialty Chemicals.

  Examples of the acylphosphine (oxide) compound include Irgacure 819, Darocur 4265, and Darocur TPO manufactured by Ciba Specialty Chemicals.

  Among these, from the viewpoint of exposure sensitivity and transparency, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2,2'- Bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, N, N-diethylaminobenzophenone, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O -Benzoyloxime)] is particularly preferred.

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

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

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

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

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

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

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

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

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

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

  The content of the polymer is preferably 5% by mass to 90% by mass with respect to the entire conductive layer, more preferably 10% by mass to 85% by mass, and still more preferably 20% by mass to 80% by mass. When the content is in the range, both developability and conductivity of the metal nanowire can be achieved.

-Dispersant-
The dispersant is used for preventing and dispersing the conductive fibers. The dispersant is not particularly limited as long as the conductive fibers can be dispersed, and can be appropriately selected according to the purpose. For example, commercially available low molecular pigment dispersants and polymer pigment dispersants can be used. In particular, a polymer dispersant having a property of adsorbing to conductive fibers is preferably used. For example, polyvinylpyrrolidone, BYK series (manufactured by Big Chemie), Solsperse series (manufactured by Nippon Lubrizol, etc.), Ajisper series ( Ajinomoto Co., Inc.).

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

<Base material>
The substrate is not particularly limited and can be appropriately selected depending on the purpose. For example, a transparent glass substrate, a synthetic resin sheet, a film, a metal substrate, a ceramic plate, a semiconductor substrate having a photoelectric conversion element, and the like. 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, polyimide, and the like.
Examples of the metal substrate include an aluminum plate, a copper plate, a nickel plate, and a stainless plate.

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

The thickness of the substrate 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, and if it exceeds 5,000 μm, the thickness and mass of the substrate may be reduced in portable applications. May be a problem.

-Photosensitive layer-
In the present invention, when the conductive layer does not contain a photosensitive compound as a dispersion medium, one of the surface on the substrate side of the conductive layer and the surface on the side of the conductive layer not having the substrate. It is preferable to have a photosensitive layer.
The photosensitive layer contains at least a photosensitive compound, and contains a polymer and, if necessary, other components.
There is no restriction | limiting in particular as said photosensitive compound and polymer, Although it can select suitably according to the objective, For example, the thing similar to the said conductive layer can be used.
There is no restriction | limiting in particular in the thickness of the said photosensitive layer, Although it can select suitably according to the objective, It is preferable that they are 0.01 micrometer-100 micrometers, and it is more preferable that they are 0.05 micrometer-10 micrometers.

(Manufacturing method of conductive film)
The method for producing a conductive film of the present invention includes a first patterning step and a second patterning step, and further includes other steps as necessary.

<First patterning step>
The first patterning step is a step of forming a pattern on the conductive layer in a conductive film having a conductive layer containing at least conductive fibers on a substrate.

  The method of the first patterning step is not particularly limited and may be appropriately selected depending on the purpose. For example, photolithography, ablation by partial irradiation with heat, electromagnetic waves, electron beams, or particles, fluids, etc. Examples thereof include a method of partially removing the dispersion medium by partial irradiation, or a combination thereof. Among these, the photolithography method is particularly preferable.

As the photolithography method, for example, (1) when the conductive layer contains a photosensitive compound as a dispersion medium, the first patterning step is performed by exposing and developing the conductive layer. (2) In the case where the photosensitive layer is provided on either the substrate-side surface of the conductive layer or the surface of the conductive layer that does not have the substrate, the first patterning step may Examples include a method performed by exposing and developing the photosensitive layer and the conductive layer, or a combination thereof.
The method (1) is preferable from the viewpoint of simplifying the layer structure of the conductive film and facilitating electrical conduction between the conductive layer and the outside.
According to the method (2), when the conductive layer has a photosensitive layer on the side having no base material, the conductive layer is externally stimulated by the photosensitive layer (for example, light, humidity, pressure, gas, etc.). ) From the viewpoint of easy protection.

  The conductive film of the present invention will be described below in order to remove the conductive fibers and the dispersion medium that protrude from the pattern edge, which causes the pattern edge roughness to deteriorate in the pattern obtained by the first patterning step. It is preferably formed through a second patterning step.

<Second patterning step>
The second patterning step is a step of removing the conductive fibers protruding from the pattern edge formed in the first patterning step.

  Examples of the second patterning step include (1) a method by ultrasonic irradiation, (2) dissolution by an etching solution, (3) ozone irradiation, (4) dissolution by anodic oxidation, or a combination thereof.

At this time, it is preferable to remove the conductive fiber and, if necessary, the dispersion medium, selectively removing only the portion protruding from the pattern edge of the conductive layer in order not to impair the conductivity of the pattern portion. In particular, the reduction of the dispersion medium, which is advantageous for improving the conductivity, or the thinning of the conductive layer, which is advantageous for improving the transmittance, damages the conductive fibers and dispersion medium of the pattern in the second patterning step, There is a risk of impairing conductivity, and caution is required. Among these, it is difficult to avoid dissolution of the metal in the pattern portion by using a metal for the conductive fiber and removing it by dissolution with an etching solution having strong oxidizing power.
In this case, forming a protective layer that does not include conductive fibers patterned to have the same shape as the conductive layer on the conductive layer avoids damage to the conductive fibers in the pattern portion. It becomes effective. However, from the viewpoint of simplifying the layer configuration of the conductive film and facilitating conduction between the conductive layer and the outside, it is preferable to perform the second patterning step without forming a protective layer on the conductive layer. From such a viewpoint, (1) ultrasonic irradiation and (2) dissolution with an etching solution are particularly preferable.

The ultrasonic irradiation of the above (1) can dramatically improve the pattern edge roughness without substantially impairing the conductivity of the pattern portion and without requiring a special processing solution. As a method of the second patterning step This is the most preferable method.
The conditions for the ultrasonic irradiation are not particularly limited, and may vary depending on the output of the ultrasonic wave, the frequency, and the configuration of the conductive film. However, the frequency of the ultrasonic wave is preferably 5 kHz to 10 GHz, preferably 10 kHz. -1 MHz is more preferable, and 15 kHz to 400 kHz is even more preferable. In the present invention, the ultrasonic wave means an elastic wave that is not intended to be heard by a person, and includes frequencies in a range that can be heard by a person. The output of the ultrasonic wave is preferably 10 W to 10 kW, and more preferably 100 W to 2 kW. The irradiation time of the ultrasonic waves is preferably 1 second to 1 hour, and more preferably 10 seconds to 10 minutes.

As a method of irradiating the ultrasonic wave, it is preferable to irradiate the conductive film with ultrasonic waves in a solution, and a commercially available ultrasonic cleaner can be preferably used. Moreover, the irradiation of ultrasonic waves may be performed batchwise on the conductive film, or may be continuously performed while the substrate is conveyed.
There is no restriction | limiting in particular as a solvent of the bath used at the time of the said ultrasonic wave irradiation, According to the objective, it can select suitably, Both water and an organic solvent can be used preferably, but there is little environmental impact and it is not necessary for explosion-proof correspondence. Water is particularly preferred. Moreover, there is no restriction | limiting in particular as a composition of a bath, Although 2nd patterning is preferably possible with water, it can contain all the additives considered useful. Specifically, surfactants, antifoaming agents, curing agents, rust inhibitors, anticorrosives, oxidizing agents, antioxidants, reducing agents, acids, alkalis, and the like can be preferably contained depending on the purpose. In addition, when photolithography is used as the first patterning step, it is also preferable that the first patterning step and the second patterning step are performed simultaneously by performing development after exposure while irradiating with ultrasonic waves.

  There is no restriction | limiting in particular as melt | dissolution by the etching liquid of said (2), Although it can select suitably according to the objective, The method of using a halide ion containing solution as an etching liquid is preferable. By immersing the conductive film after the first patterning step in a halide ion-containing solution such as a sodium chloride solution, the conductive layer protruding from the pattern edge can be selectively removed. Although the mechanism is not clear, it is considered that there is a possibility that a local battery of the conductive layer was formed in the halide-containing solution and the conductive fibers were removed by anodic oxidation.

The halide ion is not particularly limited and may be appropriately selected depending on the intended purpose. For example, halide ions such as chloride ion, bromide ion, iodide ion, fluoride ion, further cyanide ion, Pseudohalide ions such as thiocyanide ions can also be used. Among these, chloride ions are particularly preferable.
There is no restriction | limiting in particular as a counter ion of the said halide ion, Although it can select suitably according to the objective, For example, an alkali metal ion, an alkaline-earth metal ion, an ammonium ion etc. are suitable. Among these, alkali metal ions such as Na and K are particularly preferable.
The halide ion-containing solution is preferably a solution containing at least one of a sodium chloride solution, a potassium chloride solution, an ammonium chloride solution, and a calcium chloride solution. From the viewpoint of cost and environmental impact, the sodium chloride solution Is particularly preferred.
The content of the halide ions in the halide ion-containing solution is preferably 1% by mass to 30% by mass, and more preferably 2% by mass to 15% by mass.
The etching method using the halide ion-containing solution is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the conductive film after the first patterning step may be used in a halide ion-containing solution. It is preferable to perform the treatment for 1 minute to 5 minutes with stirring at room temperature while stirring. The treated conductive film is rinsed with running ion exchange water and dried.

The surface resistance of the conductive film of the present invention is preferably 0.1Ω / □ to 10,000Ω / □, and more preferably 0.1Ω / □ to 1,000Ω / □. The low surface resistance itself is not harmful, but if it is less than 0.1 Ω / □, it may be difficult to obtain a conductive film with high light transmittance. If it exceeds 10,000 Ω / □, There may be a problem that disconnection due to Joule heat generated during energization is likely to occur, a voltage drop occurs upstream and downstream of the wiring, and the area used for the touch panel is limited.
Here, the said surface resistance can measure surface resistance, for example using the surface resistance meter (the Mitsubishi Chemical Corporation make, Loresta-GP MCP-T600) about each obtained electrically conductive film.

The light transmittance of the conductive film of the present invention is preferably 70% or more, and more preferably 80% or more. When the light transmittance is less than 70%, the conductive pattern becomes conspicuous when used in an image display medium such as a touch panel, and it is necessary to increase the power consumption in order to reduce the image quality or compensate for the decrease in luminance. Detrimental effects such as occurrence may occur.
Here, the said transmittance | permeability can be measured with a self-recording spectrophotometer (UV2400-PC, Shimadzu Corporation make), for example.

  The conductive film of the present invention can remarkably improve insulation, has high permeability and low resistance, and can easily form fine patterns. For example, a touch panel, an electrode for display, an electromagnetic wave shield, an electrode for organic or inorganic EL display It is widely applied to 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 uses the conductive film of the present invention.
The touch panel is not particularly limited as long as it has the conductive film, and can be appropriately selected according to the purpose. For example, a surface capacitive touch panel, a projected capacitive touch panel, a resistive touch panel Etc.

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

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

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

(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.

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

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

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

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

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

<Ratio of silver 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 ratio of silver nanowires having an aspect ratio of 10 or more is measured for silver nanowires each having an average minor axis length of 50 nm or less and an average major axis length of 5 μm or more. (%).
The silver nanowires were separated when determining the ratio of silver nanowires using a membrane filter (Millipore, FALP 02500, pore size 1.0 μm).

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

The following composition was prepared as a negative photoresist (photocurable composition).
0.241 parts by mass of binder (A-1) in Synthesis Example 1, 0.252 parts by mass of KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.) as a photosensitive compound, IRGACURE 379 (Ciba Specialty Chemicals Co., Ltd.) as a photosensitive compound (Made by company) 0.0252 parts by mass, EHPE-3150 (manufactured by Daicel Chemical Industries, Ltd.) 0.0237 parts by mass, MegaFac F781F (made by DIC) 0.0003 parts by mass, propylene glycol monomethyl ether acetate ( PGMEA) 0.9611 parts by mass, 1-methoxy-2-propanol (MFG) 44.3 parts by mass, 54.1 parts by mass of the silver nanowire MFG dispersion Ag-1 were added and stirred to obtain. The composition was designated as photosensitive composition (1).
Here, the mass ratio (A / B) between the total content A of the dispersion medium and the content B of the conductive fibers was 1.05.

-Production of conductive film-
Next, the obtained negative conductive layer composition was applied on a polyethylene terephthalate (PET) film having a thickness of 75 μm so that the applied silver amount was 0.05 g / m ^2, and dried at room temperature, A conductive film was obtained.

A first patterning step by photolithography was performed on the obtained conductive film by the following method. As described above, the sample No. 1-1 was produced.
-First patterning step-
Adhesion exposure was performed using an optical mask including a patterning region (rectangular pattern and numbers) for measuring edge roughness and a transparent region for measuring optical characteristics and conductive characteristics. The exposure was performed with 100 mJ / cm ² (illuminance 20 mW / cm ² ) of high-pressure mercury lamp i-line (365 nm). A 1.0% by weight developer solution (1 part by weight of CDK-1 and 99 parts by weight of pure water) of a potassium hydroxide developer CDK-1 (manufactured by FUJIFILM Electronics Materials) after exposure, At 25 ° C., shower development was performed for 30 seconds to remove unexposed portions. The shower pressure was 0.04 MPa, and the time until the exposure pattern appeared was 15 seconds.

<Sample No. 1-2>
Sample No. The conductive film after the first patterning process of 1-1 was irradiated with ultrasonic waves for 2 minutes in ion-exchanged water under conditions of 40 kHz and 160 W using an ultrasonic cleaning machine (manufactured by As One Co., Ltd., USD-4R). . Next, after rinsing with running ion-exchanged water for 1 minute, the sample was dried and dried. 1-2 was produced.

<Sample No. 1-3>
Sample No. In Sample 1-2, sample No. 1 was used except that ultrasonic waves were applied for 0.5 minutes under the conditions of 40 kHz and 160 W. In the same manner as in 1-2, Sample No. 1-3 was produced.

<Sample No. 1-4>
Sample No. In Sample 1-2, sample No. 1 was irradiated except that ultrasonic waves were applied for 5 minutes under the conditions of 40 kHz and 160 W. In the same manner as in 1-2, Sample No. 1-4 was produced.

<Sample No. 1-5>
Sample No. In Sample 1-2, sample No. 1 was used except that ultrasonic waves were applied for 5 minutes under the conditions of 28 kHz and 160 W. In the same manner as in 1-2, Sample No. 1-5 was produced.

<Sample No. 1-6>
Sample No. The conductive film after the first patterning step 1-1 was etched in a 30% by mass aqueous sodium chloride solution at 25 ° C. for 5 minutes. Next, after rinsing with running ion-exchanged water for 1 minute, the sample No. 1 was dried by drying. 1-6 was produced.

<Sample No. 1-7>
Sample No. Sample No. 1-6 except that the etching treatment was performed for 2 minutes while stirring at 25 ° C. in a 30 mass% sodium chloride aqueous solution. In the same manner as in 1-6, sample no. 1-7 was produced.

<Sample No. 1-8>
Sample No. Sample No. 1-6 except that the etching treatment was performed for 1 minute with stirring at 25 ° C. in a 30% by mass sodium chloride aqueous solution. In the same manner as in 1-6, sample no. 1-8 was produced.

<Sample No. 1-9>
Sample No. Sample No. 1-6 except that the etching treatment was performed for 5 minutes while stirring at 25 ° C. in a 10 mass% sodium chloride aqueous solution. In the same manner as in 1-6, sample no. 1-9 was produced.

<Sample No. 1-10>
Sample No. The conductive film after the first patterning step 1-1 was etched for 30 seconds in an etching solution A having the following composition at 25 ° C. with stirring. Next, after rinsing with running ion-exchanged water for 1 minute, the sample No. 1 was dried by drying. 1-10 was produced.
-Etching solution A-
・ Ethylenediaminetetraacetic acid iron (III) ammonium ... 2.71 g
・ Ethylenediaminetetraacetic acid disodium dihydrogen dihydrate ・ ・ ・ 0.17g
・ Ammonium thiosulfate (70 mass%) ... 3.61 g
・ Sodium sulfite 0.84g
-Glacial acetic acid: 0.43 g
-Add water to make a total of 1,000 mL
The etching solution A shown here is a composition obtained by diluting a general bleach-fixing solution for a silver halide photographic light-sensitive material, and has a strong oxidizing power against silver.

<Sample No. 1-11>
Sample No. Sample No. 1-10 except that the etching treatment was performed in the etching solution A at 25 ° C. for 1 minute in 1-10. In the same manner as in 1-10, the sample No. 1-11 was produced.

<Sample No. 1-12>
Sample No. 1-10 except that the etching treatment was performed in the etching solution A at 25 ° C. with stirring for 1 minute and 30 seconds. In the same manner as in Sample No. 1-10, Sample No. 1-12 was produced.

Next, the produced sample No. 1-1 to sample no. For 1-12, the pattern edge roughness, surface resistance, light transmittance, haze value, and flexibility were measured as follows. The results are shown in Table 2. Sample No. About 1-1 and 1-2, it observed with the digital microscope (VHX-600, the Keyence Corporation make, magnification 2,000 times). Sample No. The observation result of 1-1 is shown in FIG. Sample No. The observation result of 1-2 is shown in FIG.
From the results of FIGS. 6 and 7, it was found that the silver nanowires protruding from the pattern edge of FIG. 6 were selectively removed in FIG. 7 to form a fine pattern.
Sample No. The observation results with 1-12 digital microscope are shown in FIG. From the result of FIG. 8, the density of the conductive fibers in the pattern portion is the sample No. It turned out that it has decreased with respect to 1-2.

<Pattern edge roughness>
Pattern edge roughness was calculated | required as follows about each produced electrically conductive film using the digital microscope (VHX-600, the Keyence Corporation make, magnification 2,000 times).
An edge region including the average line of the pattern edge over a length of 100 μm is extracted and divided into 10 sections so that each section includes an average line length of 10 μm, and the maximum width of the distance is obtained from the average line in each section. The average value of the maximum widths from the maximum width of each section to the top five was calculated and defined as the pattern edge roughness. However, when the total length of the average line of the pattern edge is less than 100 μm, the pattern edge region is equally divided into 10 along the average line, and the maximum width from the average line is obtained in each section. The average value of the maximum width from the maximum width to the top five was defined as the pattern edge roughness.
FIG. 1 is a schematic view of a conductive pattern after patterning as viewed from above for explaining how to obtain pattern edge roughness. In FIG. 1, the pattern edge was divided into regions including an average line length of 10 μm along the average line, and the maximum width of the distance from the average line was determined in each section (W1, W2, W3 in FIG. 1). This operation was performed over 10 sections, and the average value of the values up to the top 5 was obtained from the maximum width of the distance from the average line from W1 to W10, and this was used as the pattern edge roughness. 1 illustrates the case where the average line is a straight line, the same applies to the case where the average line is a curve.

<Evaluation of resolution>
In order to evaluate the resolution of each conductive film, Sample No. 1-1 and Sample No. Regarding 1-2, the result of observation with the above-mentioned digital microscope is shown for a region including a portion in which the exposure pattern is further miniaturized and both the pattern width and the pattern interval width (that is, the line / space width) are 4.5 μm. 9 and FIG. FIG. 1-1 is a photograph showing the observation results of the digital microscope 1-1. It is a photograph which shows the observation result by the digital microscope of 1-2.
From the results of FIG. 9 and FIG. In the case of 1-2, the line / space width can separate the conductive portions even in this exposure pattern and has a good resolution of about 4.5 μm. In 1-1, it was found that the pattern was not separated and the resolution was insufficient.

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

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

<Measurement of haze value>
The haze value (%) of each conductive film obtained after the patterning treatment was measured using a haze guard plus manufactured by Gardner.

<Flexibility of conductive film>
In order to evaluate the flexibility of each conductive film, Sample No. 1-1 to Sample No. 1-12 was wound outwardly on a cylindrical acrylic resin having a diameter of 10 mm and left for 3 days, and then the pattern edge roughness, surface resistance, light transmittance, and haze value of each conductive film were measured. The evaluation was based on the following criteria.
〔Evaluation criteria〕
○: No change in pattern edge roughness, surface resistance, light transmittance, and haze value after standing for 3 days. X: At least any of pattern edge roughness, surface resistance, light transmittance, and haze value after standing for 3 days. Crab changes

From the results in Table 2, it was found that ultrasonic cleaning was most preferable as the second patterning step, and immersion in a sodium chloride solution was also preferable. In the etching solution A containing EDTA as a strong oxidizing agent, the edge roughness can be improved, but a decrease in sheet resistance value is observed.
Sample No. 1-1 to sample no. 1-12 was found to have sufficient flexibility. This was the same when the winding direction was changed inward.

(Example 2)
In Example 1, the negative type conductive layer composition was replaced with the positive type conductive layer composition prepared as follows, and the sample No. was changed in the same manner as in Example 1 except that the exposure and development conditions were further changed. . 1-1 to No. Sample No. 1-12 corresponding to 1-12. 2-1 to Sample No. 2-12 was produced.
The prepared sample No. 2-1 to Sample No. About 2-12, it carried out similarly to Example 1, and measured the edge roughness, the surface resistance, the light transmittance, and the haze value. The results are shown in Table 3.

-Preparation of positive conductive layer composition-
The following composition was prepared as a positive photoresist (photo-solubilizing composition).
0.402 parts by mass of binder (A-1) in Synthesis Example 1, TAS-200 (esterification rate 66%, manufactured by Toyo Gosei Co., Ltd.) 0.228 parts by mass as a dispersion medium, crosslinked 0.192 parts by mass of EHPE-3150 (manufactured by Daicel Chemical Industries, Ltd.), 5.17 parts by mass of propylene glycol monomethyl ether acetate (PGMEA), 221 parts by mass of 1-methoxy-2-propanol (MFG), and silver 41.0 parts by mass of nanowire MFG dispersion Ag-1 was added and stirred, and the resulting composition was designated as photosensitive composition (2).

The obtained photosensitive composition (2) is coated on a non-alkali glass having a thickness of 0.7 mm using a wire bar coater so that the amount of coated silver is 0.075 g / m ² and dried at room temperature. As a result, a conductive film was obtained. Here, the mass ratio (A / B) between the total content A of the dispersion medium and the content B of the conductive fibers was 1.55.

<Exposure and development process (first patterning process)>
Contact exposure was performed using an optical mask including a patterning region (rectangular pattern and number pattern) for measuring edge roughness and a transparent region for measuring optical characteristics and conductive characteristics. The exposure was performed under conditions of 150 mJ / cm ² (illuminance 20 mW / cm ² ) using a high-pressure mercury lamp i-line (365 nm). The exposed conductive film was subjected to paddle development for 90 seconds with a 0.4 mass% TMAH aqueous solution (23 ° C.) to remove the exposed portion. After the developed conductive film is dried at room temperature, it is post-exposed with a high-pressure mercury lamp i-line (365 nm) at 300 mJ / cm ² (illuminance 20 mW / cm ² ), and further post-baked at 170 ° C. for 10 minutes. went.

From the results in Table 3, it was found that ultrasonic cleaning was most preferable as the second patterning step, and immersion in a sodium chloride solution was also preferable. In the etching solution A containing EDTA as a strong oxidizing agent, the edge roughness can be improved, but a decrease in sheet resistance value is observed.

(Example 3)
-Fabrication of touch panel-
Sample No. For the conductive film 1-2, a conductive film was prepared by a method different only in that the exposure pattern was changed to the checkered pattern shown in FIG. 4, and the characteristics of surface resistance, edge roughness, transmittance, and haze value were measured. No. It was confirmed that it was substantially the same as 1-2. When using a touch panel manufactured using this conductive film, it has excellent visibility due to the improved transmittance, and a bare hand, a gloved hand, an indicator, etc. It was found that a touch panel with excellent responsiveness to input or screen operation can be manufactured. The touch panel includes a so-called touch sensor and a touch pad.
For the production of touch panels, “latest touch panel technology” (issued July 6, 2009, Techno Times), supervised by Yuji Mitani, “Technology and Development of Touch Panels”, CM Publishing (2004, 12), FPD International 2009 The publicly known methods described in the Forum T-11 lecture textbook, Cypress Semiconductor Corporation application note AN2292, etc. were used.

Example 4
<Production of integrated solar cell>
-Fabrication of amorphous solar cells (super straight type)-
Sample No. A conductive film was prepared in the same manner as in 1-2, except that the support was changed from PET to a glass substrate.
A p-type film having a thickness of about 15 nm is formed on the obtained conductive film by plasma CVD, an i-type film having a thickness of about 350 nm is formed on the p-type film, and an n-type amorphous silicon film having a thickness of about 30 nm is formed on the i-type film. A gallium-doped zinc oxide layer having a thickness of 20 nm was formed on the n-type amorphous silicon as a back surface reflecting electrode, and a silver layer having a thickness of 200 nm was formed on the gallium-doped zinc oxide layer. Thus, a photoelectric conversion element of Example 4 was produced.

(Example 5)
<Production of integrated solar cell>
-Fabrication of amorphous solar cells (super straight type)-
In Example 4, sample no. The conductive film of 1-2 was sample No. A photoelectric conversion element of Example 5 was produced in the same manner as Example 4 except that the conductive film of 2-2 was used.

(Example 6)
<Production of integrated solar cell>
-Fabrication of CIGS solar cells (substrate type)-
Sample No. A conductive film was prepared in the same manner as in 1-2, except that the support was changed from PET to a support prepared by the following method.
-Production method of support-
A molybdenum electrode having a thickness of about 500 nm is formed on a glass substrate by a direct current magnetron sputtering method, and Cu (In _0.6 Ga _0.4 ) which is a chalcopyrite semiconductor material having a thickness of about 2.5 μm is formed on the electrode by a vacuum deposition method. A cadmium sulfide thin film having a thickness of about 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. This was used as a support.
After producing the conductive film, a boron-added zinc oxide thin film (transparent conductive layer) having a thickness of about 100 nm was formed on the conductive film by direct current magnetron sputtering to produce a photoelectric conversion element.

(Example 7)
<Production of integrated solar cell>
In Example 6, sample no. The conductive film of 1-2 was sample No. A photoelectric conversion element of Example 7 was produced in the same manner as Example 6 except that the conductive film of 2-2 was used.

<Evaluation of solar cell characteristics (conversion efficiency)>
About each produced solar cell of Example 4-7, the solar cell characteristic (conversion efficiency) was measured by irradiating the pseudo-sunlight of AM1.5 and 100 mW / cm < ² >. The results are shown in Table 4.

  The conductive film of the present invention can remarkably improve insulation, has high permeability and low resistance, improves flexibility, and can easily form fine patterns. For example, touch panels, antistatics for displays, electromagnetic waves It can be widely used for shields, electrodes for organic or inorganic EL displays, electronic paper, electrodes for flexible displays, antistatics for flexible displays, solar cells, and other various devices.

Claims (14)

A substrate and a conductive layer containing at least conductive fibers on the substrate;
A conductive film, wherein the conductive layer is patterned and the pattern edge roughness is 5 μm or less.   The conductive layer contains a dispersion medium, and the mass ratio (A / B) of the total content A of the dispersion medium and the content B of conductive fibers is 0.1 to 5.0. Conductive film.   The conductive film according to claim 1, wherein the conductive fiber has an average minor axis length of 100 nm or less and an average major axis length of 5 μm or more.   The conductive film according to claim 1, wherein the conductive fiber is a metal nanowire.   The conductive film according to claim 4, wherein the metal nanowire contains silver.   The conductive film according to claim 1, which has a light transmittance of 70% or more.   7. The conductive film according to claim 1, wherein the surface resistance is 0.1Ω / □ to 10,000Ω / □. A first patterning step of forming a pattern on the conductive layer in a conductive film having a conductive layer containing at least conductive fibers on a substrate;
A second patterning step of removing conductive fibers protruding from the edges of the formed pattern;
The manufacturing method of the electrically conductive film characterized by including.   The method for producing a conductive film according to claim 8, wherein the second patterning step is performed by immersing the conductive film patterned in the first patterning step in a liquid and irradiating with ultrasonic waves.   The conductive fiber contains silver, and the second patterning step is performed by bringing the conductive film patterned in the first patterning step into contact with the halide ion-containing solution. Of manufacturing the conductive film. The conductive layer contains a photosensitive compound;
The method for producing a conductive film according to claim 8, wherein the first patterning step is performed by exposing and developing the conductive layer. Having a photosensitive layer on one of the surface of the conductive layer on the substrate side and the surface of the conductive layer on the side not having the substrate;
The method for producing a conductive film according to claim 8, wherein the first patterning step is performed by exposing the photosensitive layer and developing the photosensitive layer and the conductive layer.   A touch panel using the conductive film according to claim 1.   An integrated solar cell using the conductive film according to claim 1.