JP2012074206A - Production method and production apparatus of conductive film, and conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a conductive film capable of producing a conductive film having excellent conductivity and optical transparency easily and inexpensively on a substrate even if a general purpose polymer substrate such as a PET film is used, and to provide a conductive film.SOLUTION: The method of producing a conductive film having a pattern by coating a substrate with an organic solvent dispersion body containing conductive fine particles includes a step for forming a film having a pattern, after coating the substrate with an organic solvent dispersion body, by evaporating the organic solvent while condensing the organic solvent dispersion body on the coating film surface, and a step for making a solvent solution containing the organic solvent act on the film having that pattern.

Description

The present invention relates to a method for manufacturing a conductive film, a manufacturing apparatus, and a conductive film. More specifically, the present invention relates to a manufacturing method, a manufacturing apparatus, and a conductive film of a conductive film that can be suitably used for a thin display such as a liquid crystal display, a plasma display, and electronic paper (digital paper), and a touch panel.

Conductive films have been applied to various electrical devices, and in particular, in recent years, demand for thin displays such as liquid crystal displays, plasma displays, and electronic paper (digital paper) has increased, and they are applied to such applications. As the conductive film, a film excellent in light transmittance and conductivity is particularly demanded, and research and development are being actively conducted.
Currently, indium tin oxide (ITO) is generally used as a light-transmitting conductive film. A conductive film made of indium tin oxide has an excellent balance between light transmittance and conductivity, and is used not only for a normal liquid crystal display or the like but also for a touch panel, for example. However, since rare metals such as indium are expensive and there is a risk of resource depletion, there is a need for a conductive film having light transmittance using a material that is less expensive and less likely to be depleted of resources. By the way. Further, since a sputtering method or the like is usually used for forming an ITO film, there is room for improvement in terms of low productivity.

As the form of the light-transmitting conductive film, a conductive film using a light-transmitting and conductive material such as indium tin oxide, a mesh-like conductive film, or a mesh The form of the conductive film is mentioned. As a mesh-like conductive film and its manufacturing method, for example,
A method for producing a network-like conductive film by applying an organic solvent dispersion containing conductive fine particles to a substrate and evaporating the organic solvent while the applied organic solvent dispersion is condensed on the surface of the coating film. For example, refer to Patent Document 1.) Conducting a process of treating a metal fine particle layer with an organic solvent and then a process of treating with an acid to produce a conductive substrate in which a metal fine particle layer is laminated on at least one side of the substrate in a mesh shape. Is disclosed (for example, see Patent Document 2).
Further, as a method for producing a conductive film, a step of allowing a polar solvent solution containing a polar solvent or a solubilizing agent to act on a metal nanoparticle paste containing a coated metal nanoparticle and a dispersion solvent on a substrate, and It has been disclosed that a conductive film can be formed by sintering metal nanoparticles by a step of drying the substrate (see, for example, Patent Document 3).

JP 2010-34039 A (pages 1 and 2) Republished patent WO2007 / 114076 (page 23) JP 2008-72052 A (pages 1 and 2)

As described above, various methods have been studied for producing a light-transmitting conductive film at a low cost. In a light-transmitting conductive film, a light-transmitting and conductive property can be achieved at a high level by using a conductive film having a fine pattern of mesh or mesh. The methods described in 2 and 3 are not sufficient for obtaining a fine pattern, and there is room for improvement to obtain a conductive film having a fine pattern.
Moreover, according to the method for producing a conductive film described in Patent Document 1, it is possible to produce a conductive film having a fine mesh pattern. However, in the method of Patent Document 1, since it is necessary to perform a baking step at a high temperature, it is difficult to apply to the production of a conductive film using a general-purpose polymer film such as a PET film as a substrate. For this reason, there has been room for further contrivance for providing a method for forming a conductive film having light permeability easily at low cost on a highly versatile polymer film substrate such as a PET film.
For these reasons, there has been a demand for a method for forming a conductive film that can achieve both high light transmission and high conductivity without requiring high-temperature treatment and more easily and inexpensively. . If such a problem can be solved, the material of the substrate can be selected, and a highly versatile polymer film substrate such as a PET film can be easily and inexpensively and has excellent light transmission and conductivity. Since a film can be formed, its technical significance is great.

The present invention has been made in view of the above situation, and even when a general-purpose polymer substrate such as a PET film is used, a conductive film having excellent conductivity and light transmittance on a substrate can be simply and easily formed. An object of the present invention is to provide a conductive film manufacturing method and a conductive film that can be manufactured at low cost.

The present inventor has been able to use a general-purpose polymer substrate, and variously studied methods for producing a conductive film having excellent conductivity and light transmittance. After the organic solvent dispersion was applied to the substrate, A step of forming a film having a pattern by evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film, and a step of allowing a solvent solution containing the organic solvent to act on the film having the pattern Is performed to form a conductive film that has both a high level of conductivity and light transmission because it has a mesh-like line portion of a conductive material with a narrow line width and fine mesh and a void portion. I found that I can do it. According to this method, a conductive film can be formed without firing at a high temperature. Therefore, it has excellent conductivity and light transmittance even on a general-purpose polymer substrate that is not high in heat resistance such as PET film. Thus, the present inventors have arrived at the present invention by conceiving that the above-mentioned problems can be solved brilliantly.

That is, the present invention is a method of manufacturing a conductive film having a pattern by applying an organic solvent dispersion containing conductive fine particles to a substrate, and the above manufacturing method applies the organic solvent dispersion to a substrate. Thereafter, a step of forming a film having a pattern by evaporating the organic solvent while condensing the applied organic solvent dispersion on the surface of the coating film, and a solvent solution containing the organic solvent acting on the film having the pattern It is a manufacturing method of an electroconductive film including a process.
The present invention is described in detail below.

The method for producing a conductive film of the present invention is a method for producing a conductive film having a pattern by coating an organic solvent dispersion containing conductive fine particles on a substrate. In such a method, for example, film formation can be performed easily and at a lower cost as compared with a sputtering method, a plating method, and the like, and manufacturing costs can be reduced and productivity can be improved. it can. Hereinafter, the film of the organic solvent dispersion coated on the substrate is also referred to as “coating film”.

The method for producing a conductive film according to the present invention includes a step of forming a film having a pattern by evaporating the organic solvent while condensing the coated organic solvent dispersion on the surface of the coating film (self-organizing step). . By including such a process, it becomes possible to form a conductive film having a fine mesh pattern with a narrow line width, and the manufactured conductive film is not only conductive but also light transmissive. It becomes possible to make it excellent.
The details of the self-assembly process will be described later.

The manufacturing method of the electroconductive film of this invention includes the process of making the solvent solution containing an organic solvent act on the film | membrane which has the pattern formed by the said self-organization process.
As will be described later, in order to improve the dispersibility of the fine particles such as the conductive fine particles in the organic solvent dispersion, the organic solvent dispersion contains a fine particle dispersant as necessary. In that case, the conductive fine particles are coated with the fine particle dispersant. However, by causing a solvent solution containing an organic solvent to act on the film having the above pattern, the fine particle dispersant and the conductive fine particles are mixed. A solvent solution containing an organic solvent is interposed between the particles, the fine particle dispersant is washed away, and the conductive fine particles are exposed. As a result, fusion between the conductive fine particles is generated, and a layer expressing conductivity is formed. It is assumed that In this way, it is considered that a layer exhibiting electrical conductivity is formed. At that time, the solvent solution containing the organic solvent is not only a fine particle dispersant, but also an isolated extra without being fused. Conductive fine particles can be washed away at the same time. As a result, haze of the manufactured conductive film is suppressed, and the transmittance is improved.
In addition, since the pattern formed by the self-assembly process is very fine, each of the pores is very small, and it is necessary to wash away the fine particle dispersant that does not participate in conductivity or excess conductive fine particles. , The hole is likely to fill up. Therefore, a great haze suppression effect and a transmittance improvement effect are exhibited by washing away the fine particle dispersant and the extra conductive fine particles that are not involved in the conductivity.

Moreover, in the said self-organization process, in order to hold | maintain the shape of the water droplet taken in to a coating film with a suitable form so that it may mention later, it is preferable to make an organic solvent dispersion contain an amphiphilic compound. However, if an amphiphilic compound is contained in a large amount, there is a possibility that the conductivity is adversely affected. In this regard, according to the production method of the present invention, the amphiphilic compound used in the self-assembly step is used to perform the step of causing the solvent solution containing the organic solvent to act after the pattern is formed by the self-assembly step. Will also be washed away by the organic solvent. Thereby, in the case of the production method of the present invention, even if a large amount of the amphiphilic compound is used in the self-assembly process, the remaining amphiphilic compound in the conductive film can be reduced. While maintaining good conductivity, the shape of the water droplets taken into the coating is sufficiently stabilized, making it possible to more easily create the mesh of the conductive film, and the pore size of the pores from large to small Thus, it is possible to manufacture conductive films having various patterns. Further, the amphiphilic compound used in the self-assembly process is washed away with an organic solvent, whereby the line width of the film having the pattern to be formed can be made narrower. By forming a film having a pattern with a narrower line width, the transmittance of the obtained conductive film is further improved and light scattering is further suppressed, so that the haze is also lower.
In addition, in the above self-organization process, water droplets generated by condensation are taken into the coating film, and then the organic solvent is evaporated, and further, the water droplets taken in are dried, so that pores corresponding to the water droplets taken in are obtained. However, since it is necessary to dry the water droplets taken in, if the self-assembly process is performed, it takes time to manufacture the conductive film. In this regard, according to the production method of the present invention, the step of causing the solvent solution containing the organic solvent to act is performed, and therefore, when an organic solvent having a low boiling point such as methanol is used, the time for drying is shortened. Is possible. Furthermore, since it is possible to perform the step of allowing the organic solvent to act before sufficiently drying the water droplets, the total time for drying the water droplets and the organic solvent can be shortened. For these reasons, the productivity of the conductive film is improved.
For the reasons described above, when a pattern is formed by the self-assembly process and a very fine pattern is used, a method in which a solvent solution containing an organic solvent is used is a particularly preferable method.
In addition, for the first time in the present invention, it has been found and demonstrated that a remarkable effect is obtained by allowing a solvent solution containing an organic solvent to act on a film having a pattern formed by the self-assembly process. .
Moreover, in the manufacturing method of the electroconductive film of this invention, since it is possible to manufacture an electroconductive film without performing the baking process, it is general-purpose, such as PET film with low heat resistance compared with glass. This polymer film can be used as a substrate.

As described above, the method for producing a conductive film of the present invention includes a step of forming a film having a pattern by evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film, and the above The method includes a step of allowing a solvent solution containing an organic solvent to act on a film having a pattern. However, these steps may be carried out partially in parallel, or a coated organic solvent dispersion. After the step of forming a film having a pattern by evaporating the organic solvent while condensing on the coating film surface, a step of allowing a solvent solution containing the organic solvent to act on the film having the pattern may be performed. Among them, after performing a step of forming a film having a pattern by evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film, the solvent solution containing the organic solvent in the film having the pattern It is one of the preferred embodiments of the present invention to perform the step of acting.
The method for producing a conductive film of the present invention has a pattern in which an organic solvent dispersion is applied to a substrate and then the organic solvent is evaporated while the applied organic solvent dispersion is condensed on the surface of the coating film. Other steps may be included as long as it includes a step of forming a film and a step of allowing a solvent solution containing an organic solvent to act on the film having the pattern.

In the step of causing the solvent solution containing the organic solvent to act on the film having the pattern, the term “acting” is not particularly limited as long as the solvent solution containing the organic solvent acts on the film having the pattern. However, for example, a method of immersing part or all of a film having a pattern in a solvent solution containing an organic solvent, a method of applying a solvent solution containing an organic solvent to a film having a pattern, an organic solvent being applied to a film having a pattern And a method of spraying a solvent solution containing. Among these, it is preferable that the effect of the present invention can be sufficiently exerted when the film having a pattern is partly or wholly immersed in a solvent solution containing an organic solvent.

The step of allowing the solvent solution containing the organic solvent to act on the film having the pattern may be performed at any of low temperature, room temperature, and high temperature. For example, it may be performed at a temperature in the range of −20 ° C. to 150 ° C. A temperature in the range of 0 ° C to 100 ° C is more preferable. More preferably, it is performed at a temperature in the range of 10 ° C to 50 ° C.
Further, the step of causing the solvent solution containing the organic solvent to act on the film having the pattern may be performed while applying ultrasonic waves.

The step of allowing the solvent solution containing the organic solvent to act on the film having the above pattern includes the removal of the extra conductive fine particles isolated without melting the solvent solution containing the organic solvent and the fine particle dispersant used as necessary. Although it may be performed for the time required for removal, for example, it is preferably performed for 0.1 second to 1 day, and more preferably for 10 seconds to 2 hours. More preferably, it is performed for 1 to 30 minutes. Particularly preferably, it is 3 minutes to 20 minutes.

Examples of the organic solvent in the solvent solution containing the organic solvent include nonpolar solvents, polar solvents, and solubilizing agents. Among these, the solvent solution containing the organic solvent includes a polar solvent and / or a solubilizing agent. The polar solvent solution is preferably included. As said organic solvent, 1 type may be used and it is good also considering 2 types or more together as a mixed solvent.
Specific examples of the nonpolar solvent include esters such as ethyl acetate and butyl acetate; alkanes such as hexane, heptane, decane, and cyclohexane; ethers such as ethylene glycol butyl ether, ethylene glycol ethyl ether, and ethylene glycol methyl ether. And the like; toluene, chloroform, xylene and the like. Among these, esters such as ethyl acetate and butyl acetate are preferable.

Examples of the polar solvent include dipolar aprotic solvents; heterocycles; alkyl-substituted heterocycles; water; —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH. An alkane, alkene, alkyne, aromatic hydrocarbon, alkyl-substituted aromatic hydrocarbon, heterocycle, or alkyl-substituted heterocycle substituted with at least one group selected from the group consisting of: ;

(In the formula, R ¹ and R ² are the same or different and each represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkyl-substituted aryl group, a heteroaryl group, or an alkyl-substituted heteroaryl group. Y represents a group represented by —CONH—, —C (═O) —, or —SO—).
Examples of the dipolar aprotic solvent include N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide and the like.

Examples of the heterocycle include heterocycles having oxygen, sulfur, nitrogen, etc., specifically, thiophene, furan, pyran, xanthene, pyrrole, imidazole, pyrazole, thiazole, isoxazole, pyridine, pyrazine, A pyrimidine etc. are mentioned.
The alkyl-substituted heterocycle means one in which one or more hydrogen atoms of the heterocycle are substituted with an alkyl group.
As said alkyl group, a C1-C100 thing is mentioned, for example. Among these, Preferably it is a C1-C20 alkyl group, More preferably, it is a C1-C10 alkyl group, More preferably, it is a C1-C6 alkyl group. Particularly preferred is a methyl group.
Examples of such an alkyl-substituted heterocycle include a heterocycle substituted with an alkyl group having 1 to 10 carbon atoms. Specific examples include methylthiophene, hexylfuran, methylpyran, butylxanthene, methylpyrrole, pentylimidazole, octylpyrazole, hexylthiazole, pentylisoxazole, butylpyridine, methylpyrazine, and methylpyrimidine.

The _{-COOH, -SH, -SOH, -SO 2} H, -SO 3 H, and at least one alkane substituted with a group selected from the group consisting of -NH ₂ and -OH, 1 or more of the alkanes This means that one or more hydrogen atoms are substituted with the above substituents.
Examples of the alkane include those having 1 to 100 carbon atoms, which may be chain-like or branched. Among these, Preferably it is a C1-C20 alkane, More preferably, it is a C5-C15 alkane, More preferably, it is a C8-C15 alkane. Particularly preferred are 2,2,2,4-trimethylpentane and tetradecane.
Examples of the alkane substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH include, for example, formic acid , Acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, etc., hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, methane Sulfonic acid, methanol, ethanol, isopropanol, 2-methyl-2-propanol, butanol, pentanol, hexanol, heptanol, octanol, nonaol, decanol, undecanol, dodecanol, tridecanol, pentadecanol, hexadecanol, heptadecanol, Octadecanol, Nonadecano , Icosanol, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecyl Amine, octadecylamine, nonadecylamine, icosanylamine, methanethiol, ethanethiol, propanethiol, butanethiol, pentanethiol, hexanethiol, heptanethiol, octanethiol, nonanethiol, decanethiol, undecanethiol, dodecanethiol, tridecanethiol, tetradecane Thiol, pentadecanethiol, hexadecanethiol, heptadecanethiol, octadecane All, nonadecanethiol, icosanethiol and the like can be mentioned. Among these, lauric acid, myristic acid, palmitic acid, stearic acid, dodecylamine, dodecanethiol and the like are preferable.

The _{-COOH, -SH, -SOH, -SO 2} H, -SO 3 H, among the alkanes which are substituted by at least one group selected from the group consisting of -NH ₂ and -OH, in particular, with -COOH Examples of the substituted alkane include those in which 1 to 10 hydrogen atoms of an alkane having 1 to 50 carbon atoms are substituted with —COOH. Among them, preferably an alkane having 1 to 20 carbon atoms substituted with -COOH, for example, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, etc., hexanoic acid, Examples include heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, and stearic acid. More preferred is an alkane having 10 to 20 carbon atoms substituted with —COOH, and further preferred is an alkane having 12 to 18 carbon atoms substituted with —COOH.

The _{-COOH, -SH, -SOH, -SO 2} H, -SO 3 H, among the alkanes which are substituted by at least one group selected from the group consisting of -NH ₂ and -OH, in particular, -SH, Examples of the substituted alkane include those in which 1 to 10 hydrogen atoms of an alkane having 1 to 50 carbon atoms are substituted with 1 to 10 by -SH. Among these, Preferably it is C1-C20 alkane substituted by -SH, for example, methanethiol, ethanethiol, propanethiol, butanethiol, pentanethiol, hexanethiol, heptanethiol, octanethiol, nonanethiol , Decanethiol, undecanethiol, dodecanethiol, tridecanethiol, tetradecanethiol, pentadecanethiol, hexadecanethiol, heptadecanethiol, octadecanethiol, nonadecanethiol, icosanethiol. More preferred is an alkane having 3 to 17 carbon atoms substituted with —SH, and further preferred is an alkane having 5 to 15 carbon atoms substituted with —SH. Particularly preferred is dodecanethiol.

The _{-COOH, -SH, -SOH, -SO 2} H, -SO 3 H, among the alkanes which are substituted by at least one group selected from the group consisting of -NH ₂ and -OH, in particular, -NH ₂ Examples of the alkane substituted with 1 include those in which 1 to 10 hydrogen atoms of an alkane having 1 to 50 carbon atoms are substituted with —NH ₂ . Among them, preferably an alkane having from 1 to 20 carbon atoms which is substituted with -NH _2, for example, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, nonylamine, decylamine , Undecylamine, dodecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine, icosanylamine. More preferred is an alkane having 3 to 17 carbon atoms substituted with —NH ₂ , and further preferred is an alkane having 5 to 15 carbon atoms substituted with —NH ₂ . Particularly preferred is dodecylamine.

The _{-COOH, -SH, -SOH, -SO 2} H, -SO 3 H, among the alkanes which are substituted by at least one group selected from the group consisting of -NH ₂ and -OH, in particular, at -OH Examples of the substituted alkane include those in which 1 to 10 hydrogen atoms of an alkane having 1 to 50 carbon atoms are substituted with —OH. Among these, Preferably it is C1-C20 alkane substituted by -OH, for example, methanol, ethanol, isopropanol, 2-methyl-2-propanol, butanol, pentanol, hexanol, heptanol, octanol, nonaol , Decanol, undecanol, dodecanol, tridecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, icosanol, 3-methoxy-3-methyl-1-butanol, 1,3-butanediol, 3- And methyl-1,3-butanediol. More preferably, it is an alkane having 1 to 10 carbon atoms substituted with —OH.

The alkene substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH is one or more of the alkene. This means that one or more hydrogen atoms are substituted with the above substituents.
Examples of the alkene include those having 2 to 100 carbon atoms, which may be chain-like or branched. Among these, Preferably it is a C2-C20 alkene, More preferably, it is a C3-C10 alkene, More preferably, it is a C3-C5 alkene.
Examples of the alkene substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH include allyl. Alcohol, vinylamine, propenylamine, butenylamine, pentenylamine, hexenylamine, heptenylamine, octenylamine, nonenylamine, decenylamine, undecenylamine, dodecenylamine, tridecenylamine, tetradecenylamine, pentadecenylamine, hexadecenylamine, heptade Cenylamine, octadecenylamine, nonadecenylamine, oleylamine, icocenylamine, nonacosenylamine, ethenethiol, propenethiol (allyl mercaptan), butenethiol, pentenethio Hexene thiol, heptene thiol, octene thiol, nonene thiol, decene thiol, undecene thiol, dodecene thiol, tridecene thiol, tetradecene thiol, pentadecene thiol, hexadecene thiol, heptacene thiol, octadecenti All, nonadecenethiol, icosenethiol, nonacosethiol, acrylic acid (propenoic acid), methacrylic acid (2-methylpropenoic acid), crotonic acid (trans-but-2-enoic acid), isocrotonic acid (cis- (But-2-enoic acid), hexenoic acid, heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenic acid, oleic acid (cis-octadeca) -9-D Acid), elaidic acid (trans-octadeca-9-enoic acid), maleic acid (cis-butenedioic acid), fumaric acid (trans-butenedioic acid), and the like. Among these, oleylamine, allyl mercaptan, oleic acid and the like are preferable.

The _{-COOH, -SH, -SOH, -SO 2} H, -SO 3 H, among the alkene which is substituted by at least one group selected from the group consisting of -NH ₂ and -OH, in particular, with -COOH Examples of the substituted alkene include those in which 1 to 10 hydrogen atoms of an alkene having 1 to 50 carbon atoms are substituted with —COOH. Among these, Preferably it is C2-C30 alkene substituted by -COOH, for example, acrylic acid (propenoic acid), methacrylic acid (2-methylpropenoic acid), crotonic acid (trans-but-2-ene). Enoic acid), isocrotonic acid (cis-but-2-enoic acid), hexenoic acid, heptenoic acid, octenoic acid, nonenic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, Heptadecenoic acid, oleic acid (cis-octadeca-9-enoic acid), elaidic acid (trans-octadeca-9-enoic acid), maleic acid (cis-butenedioic acid), fumaric acid (trans-butenedioic acid) It is done. More preferred is an alkene having 10 to 20 carbon atoms substituted with —COOH, and further preferred is an alkene having 15 to 20 carbon atoms substituted with —COOH. Particularly preferred is oleic acid.

Of the alkenes substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH, in particular, —SH Examples of the substituted alkene include those in which 1 to 10 hydrogen atoms of an alkene having 1 to 50 carbon atoms are substituted with —SH. Among these, Preferably it is C2-C30 alkene substituted by -SH, for example, ethene thiol, propene thiol (allyl mercaptan), butene thiol, pentene thiol, hexene thiol, heptene thiol, octene thiol, nonene thiol, Decene thiol, undecene thiol, dodecene thiol, tridecene thiol, tetradecene thiol, pentadecene thiol, hexadecene thiol, heptacene thiol, octadecene thiol, nonadecene thiol, icosene thiol, nonaco Senthiol is mentioned. More preferred is an alkene having 2 to 20 carbon atoms substituted with —SH, and further preferred is an alkene having 3 to 15 carbon atoms substituted with —SH. Particularly preferred is allyl mercaptan.

The _{-COOH, -SH, -SOH, -SO 2} H, -SO 3 H, among the alkene which is substituted by at least one group selected from the group consisting of -NH ₂ and -OH, in particular, -NH ₂ Examples of the alkene substituted with are those in which 1 to 10 hydrogen atoms of an alkene having 1 to 50 carbon atoms are substituted with —NH ₂ . Among them, preferably alkenes been C2-30 substituted with -NH _2, for example, vinyl amine, propenyl amine, butenylamine, pentenyl amine, hexenyl amine, Heputeniruamin, Okuteniruamin, Noneniruamin, Deseniruamin, undecenyl amine, Examples include dodecenylamine, tridecenylamine, tetradecenylamine, pentadecenylamine, hexadecenylamine, heptadecenylamine, octadecenylamine, nonadecenylamine, oleylamine, icosenylamine, and nonacenylamine. More preferred is an alkene having 5 to 25 carbon atoms substituted with —NH ₂ , and still more preferred is an alkene having 10 to 20 carbon atoms substituted with —NH ₂ . Particularly preferred is oleylamine.

The alkyne substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH is one or more of alkyne. This means that one or more hydrogen atoms are substituted with the above substituents.
Examples of the alkyne include those having 2 to 100 carbon atoms, which may be chain-like or branched. Among these, Preferably it is a C2-C20 alkyne, More preferably, it is a C3-C10 alkyne, More preferably, it is a C3-C5 alkyne.
Examples of the alkyne substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH include, for example, ethynethiol. And propyneylamine.

The aromatic hydrocarbon substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH is aromatic. This means that one or more hydrogen atoms of a hydrocarbon are substituted with one or more of the above substituents.
Examples of the aromatic hydrocarbon include those having 6 to 30 carbon atoms. Among these, benzene, pentalene, naphthalene, phenalene, phenanthrene and the like are preferable.
As the aromatic hydrocarbon substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH, For example, benzoic acid, benzenethiol, aniline and the like can be mentioned.

An alkyl-substituted aromatic hydrocarbon substituted with at least one group selected from the group consisting of -COOH, -SH, -SOH, -SO ₂ H, -SO ₃ H, -NH ₂ and -OH; Means that one or more hydrogen atoms of an alkyl-substituted aromatic hydrocarbon are substituted with one or more of the above substituents.
The alkyl-substituted aromatic hydrocarbon means that one or more hydrogen atoms of the aromatic hydrocarbon are substituted with an alkyl group, and the alkyl group is the same as the alkyl group described above. can do.
Examples of such an alkyl-substituted aromatic hydrocarbon include an aromatic hydrocarbon having 6 to 30 carbon atoms substituted with an alkyl group having 1 to 10 carbon atoms. Specific examples include methylbenzene (toluene), propylpentalene, hexylnaphthalene, methylphenalene, ethylphenanthrene and the like. Among these, Preferably it is the aromatic hydrocarbon substituted by the C1-C6 alkyl group, More preferably, it is the aromatic hydrocarbon substituted by the C1-C3 alkyl group. More preferably, it is toluene.
As an alkyl-substituted aromatic hydrocarbon substituted with at least one group selected from the group consisting of -COOH, -SH, -SOH, -SO ₂ H, -SO ₃ H, -NH ₂ and -OH Examples include benzyl alcohol, phenylacetic acid, dibenzyl ketone, and aniline.

The heterocyclic ring substituted with at least one group selected from the group consisting of —COOH, —SH, —SOH, —SO ₂ H, —SO ₃ H, —NH ₂ and —OH is the above-mentioned heterocyclic ring. This means one or more hydrogen atoms substituted with one or more of the above substituents, and examples thereof include carboxyl pyridine and hydroxypyrazole.

The alkyl-substituted heterocycle substituted with at least one group selected from the group consisting of -COOH, -SH, -SOH, -SO ₂ H, -SO ₃ H, -NH ₂ and -OH is as follows: The alkyl substituted heterocyclic ring means one or more hydrogen atoms substituted with one or more of the above substituents, and examples thereof include carboxyl pyridine and hydroxypyrazole.

The polar solvent has the following general formula (1);

(In the formula, R ¹ and R ² are the same or different and each represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkyl-substituted aryl group, a heteroaryl group, or an alkyl-substituted heteroaryl group. R ¹ and R ² may be directly bonded to form a ring structure.Y represents a group represented by —CONH—, —C (═O) —, or —SO—). It is also preferable that the compound is represented.

The alkyl group can be the same as the alkyl group described above.
As said alkenyl group, a C2-C100 thing is mentioned, for example. Among these, Preferably it is a C2-C10 alkenyl group, More preferably, it is a C3-C7 alkenyl group, More preferably, it is a C4-C6 alkenyl group.
Examples of the alkynyl group include those having 2 to 100 carbon atoms. Among these, Preferably it is a C2-C20 alkynyl group, More preferably, it is a C2-C10 alkynyl group, More preferably, it is a C2-C5 alkynyl group.

As said aryl group, a C6-C30 thing is mentioned, for example. Among these, a phenyl group, a pentarenyl group, a naphthalenyl group, a phenalenyl group, a phenanthrenyl group, and the like are preferable.
The alkyl-substituted aryl group means a group in which one or more hydrogen atoms of the aryl group are substituted with an alkyl group, and the alkyl group can be the same as the alkyl group. . Examples of such an alkyl-substituted aryl group include an aryl group having 6 to 30 carbon atoms substituted with an alkyl group having 1 to 10 carbon atoms. Specifically, a methylphenyl group, a propylpentanyl group, a hexylnaphthalenyl group, a methylphenalenyl group, an ethylphenanthrenyl group, and the like are preferable.

Examples of the heteroaryl group include heteroaryl groups containing oxygen, sulfur, nitrogen, etc. Among them, thiophenyl group, furanyl group, pyranyl group, xanthenyl group, pyrrolinyl group, imidazolinyl group, pyrazolinyl group, thiazolinyl Group, isoxazolinyl group, pyridinyl group, pyrazinyl group, pyrimidinyl group and the like are preferable.
The alkyl-substituted heteroaryl group means a group in which one or more hydrogen atoms of the heteroaryl group are substituted with an alkyl group, and the alkyl group is the same as the alkyl group. Can do. Examples of such an alkyl-substituted heteroaryl group include heteroaryl groups containing oxygen, sulfur, nitrogen and the like substituted with an alkyl group having 1 to 10 carbon atoms. Among them, methylthiophonyl group, hexylfuranyl group, methylpyranyl group, butylxanthenyl group, methylpyrrolinyl group, pentylimidazolinyl group, octylpyrazolinyl group, hexylthiazolinyl group, pentylisoxazolinyl Group, butylpyridinyl group, methylpyrazinyl group, methylpyrimidinyl group and the like are preferable.

In addition, examples of the form in which R ¹ and R ² in the general formula (1) are directly bonded to form a ring structure include cyclohexanone and cyclopentanone.

As the polar solvent, among those described above, alkane substituted with -OH, the following general formula (2);

(Wherein R1 ′ and R2 ′ are the same or different and each represents an alkyl group), and at least one selected from the group consisting of a ketone represented by one or more, —alkane substituted with —COOH, and water. Preferably there is. More preferably, among the alkanes having 1 to 6 carbon atoms substituted with —OH and those represented by the general formula (2), R1 ′ and R2 ′ in the formula are the same or different, and A ketone representing an alkyl group of 6; at least one selected from the group consisting of an alkane having 1 to 6 carbon atoms substituted with one or more —COOH and water, methanol, ethanol, isopropanol, 2-methyl Even more preferred are 2-propanol, acetone, acetic acid, and a mixture of acetic acid and water. Particularly preferred are methanol, ethanol, isopropanol, and 2-methyl-2-propanol, and most preferred are methanol and ethanol.

The solubilizing agent is not particularly limited as long as it has a function of enhancing the polarity of the polar solvent and a function of assisting the dissolution of the fine particle dispersant, and examples thereof include polyvinylpyrrolidone, polyvinyl alcohol, and ammonia. And polyvinylpyrrolidone, polyvinyl alcohol, and ammonia are preferable.

Examples of the case where the solvent solution containing the organic solvent used in the present invention is a polar solvent solution containing a polar solvent and a solubilizing agent include, for example, an aqueous solution of polyvinyl pyrrolidone, an aqueous solution of polyvinyl alcohol, a methanol solution of polyvinyl pyrrolidone, Examples thereof include an ethanol solution of polyvinyl pyrrolidone, an isopropanol solution of polyvinyl pyrrolidone, a 2-methyl-2-propanol solution of polyvinyl pyrrolidone, an acetone solution of polyvinyl pyrrolidone, and aqueous ammonia. Among these, preferred are an aqueous solution of polyvinyl pyrrolidone, an aqueous solution of polyvinyl alcohol, a methanol solution of polyvinyl pyrrolidone, an ethanol solution of polyvinyl pyrrolidone, and aqueous ammonia.

In the method for producing a conductive film of the present invention, after the step of allowing a solvent solution containing an organic solvent to act on the film having the pattern, the step of allowing an acid to act on the film having the pattern may be performed. . Thus, after performing the process of making the solvent solution containing an organic solvent act, by making an acid act subsequently, compared with the case where an acid is not made to act, the electroconductivity of the electroconductive film manufactured is a little. Although reduced, haze is further suppressed and a conductive film with improved transmittance can be obtained.

In the step of allowing the acid to act on the film having the pattern, the method is not particularly limited as long as the acid acts on the film having the pattern, but for example, in the acid solution, Examples include a method of immersing a part or all of the film having a pattern, a method of applying an acid solution to the film having a pattern, a method of spraying an acid solution to the film having a pattern, and the like. Among these, it is preferable to act by a method of immersing a part or all of the film having a pattern in an acid solution because the effect of the step of acting an acid can be sufficiently obtained.

The step of allowing the acid to act on the film having the above pattern may be performed at any of low temperature, room temperature, and high temperature. If a thermoplastic resin film or the like is used as a substrate, the substrate may be whitened and the transparency may be impaired. . A preferable treatment temperature is 40 ° C. or lower, more preferably 30 ° C. or lower, and further preferably 25 ° C. or lower.

The step of causing the acid to act on the film having the above pattern may be performed for a time sufficient to obtain the effect of the step of acting the acid, but further improvement in the effect is not expected even if the treatment time is too long. In other cases, it may be difficult to obtain the effect. The treatment time for allowing the acid to act is, for example, preferably 15 seconds to 60 minutes, more preferably 15 seconds to 30 minutes, and even more preferably 15 seconds to 2 minutes. Particularly preferably, it is 15 seconds to 1 minute.

The acid used in the step of allowing the acid to act on the film having the above pattern is not particularly limited, and can be appropriately selected from various organic acids and inorganic acids, and may be a strong acid or a weak acid. May be. Examples of the organic acid include acetic acid, oxalic acid, propionic acid, lactic acid, and benzenesulfonic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and the like. Among these, the acid is preferably acetic acid, hydrochloric acid, sulfuric acid, or an aqueous solution thereof, more preferably hydrochloric acid, sulfuric acid, or an aqueous solution thereof.

When an acid aqueous solution is used as the acid used in the step of allowing the acid to act on the film having the above pattern, if the acid concentration is too high, the workability is lowered and the productivity is deteriorated or the substrate is heated. When a plastic resin film or the like is used, the substrate may be whitened and transparency may be impaired. On the other hand, if it is too low, the effect of acting an acid may not be obtained. Therefore, it is preferably 0.05 to 10 mol / L, and more preferably 0.05 to 5 mol / L. More preferably, it is 0.1-1 mol / L.

The conductive fine particles used in the present invention generally mean conductive particles having an average particle diameter of 100 μm or less, and the particle diameter of the conductive fine particles is not particularly limited. It is preferable that it is 1 micrometer or less. By setting the average particle diameter to 1 μm or less, the line width of the mesh-like line portion having conductivity can be narrowed, the transmission portion of the conductive film can be widened, and the aperture ratio is improved. . Thereby, the transmittance | permeability of an electroconductive film improves. The average particle diameter of the conductive fine particles is more preferably 500 nm or less, still more preferably 100 nm or less, particularly preferably 50 nm or less, and most preferably 10 nm or less. In particular, by setting the average particle diameter to 10 nm or less, the conductivity of the formed mesh-like line portion having conductivity can be increased. Further, as the particle size distribution, the coefficient of variation is preferably within 30%, more preferably within 20%, and even more preferably within 15%.

The average particle diameter of the conductive fine particles is obtained by a number average particle diameter obtained from a TEM image (transmission electron microscope observation image) or SEM image (scanning electron microscope observation image); a powder X-ray diffraction measurement method. Crystallite diameter: The average radius obtained from the radius of inertia obtained by the X-ray small angle scattering method or the like and the scattering intensity can be used. Especially, it is preferable that it is the number average particle diameter obtained by a SEM image (scanning electron microscope observation image).
The shape of the conductive fine particles is not limited to a spherical shape, and is, for example, an elliptical spherical shape, a cubic shape, a rectangular parallelepiped shape, a pyramid shape, a needle shape, a column shape, a rod shape, a cylindrical shape, a flake shape, a plate shape (for example, a hexagonal plate shape). It can also be suitably used in the shape of a thin piece such as a string or the like.

The conductive fine particles are not particularly limited as long as the conductive fine particles contain a conductive material, and examples thereof include fine particles of metals, conductive inorganic oxides, carbon-based materials, carbide-based materials, and the like. Various metals can be used as the metal, and any form such as a single metal, an alloy, and a solid solution may be used. The metal element is not particularly limited. For example, various metal elements such as platinum, gold, silver, copper, aluminum, chromium, cobalt, and tungsten can be used, but a metal having high conductivity is preferable. The metal having high conductivity preferably contains at least one selected from the group consisting of platinum, gold, silver and copper. Further, the metal is preferably a metal having high chemical stability. For example, when the above-described method for producing a conductive film is used, steps such as dispersing conductive fine particles in an organic solvent and drying the organic solvent are performed. It is preferable that oxidation, corrosion, and the like do not occur for such a process. From the viewpoint of high chemical stability, the metal preferably contains at least one selected from the group consisting of platinum, gold and silver. Among these, it is a preferable form to contain silver from the viewpoint of cost reduction. Examples of the inorganic oxide having conductivity include indium oxides such as indium tin oxide, transparent conductive materials such as zinc oxide oxides, and non-transparent inorganic oxides having conductivity. Examples of the carbon-based material include carbon black. Examples of the carbide-based material include silicon carbide, chrome carbide, and titanium carbide. In addition, as conductive fine particles that can be used, non-conductive fine particles are surrounded by a conductive substance (metal, conductive inorganic oxide, carbon-based material, carbide-based material, etc.) that forms the conductive fine particles. Fine particles (for example, fine particles having a core-shell structure of a core “non-conductive substance” and a shell “conductive substance”) are also preferable. The non-conductive fine particles are not particularly limited, and non-conductive fine particles formed of various substances can be used. As said electroconductive fine particles, these may be used independently and 2 or more types may be used.
Furthermore, as conductive fine particles that can be used, oxide fine particles such as silver oxide and copper oxide are dispersed in an organic solvent and then applied, and then the coating film is placed in a reducing atmosphere to thereby form a metal such as silver and copper. It can also be used after being reduced. That is, the method for producing the conductive film is one of preferred embodiments including a step of reducing the oxide fine particles by coating the oxide fine particles dispersed in an organic solvent and then placing the oxide fine particles in a reducing atmosphere. is there.

The content of the conductive fine particles is preferably 0.05 to 10% by mass with respect to 100% by mass of the organic solvent dispersion. By setting it as such a range, the electroconductive film which has sufficient electroconductivity can be obtained. More preferably, it is 0.1-10 mass% as content of electroconductive fine particles, More preferably, it is 0.2-10 mass%.

The organic solvent dispersion used in the present invention is a dispersion in which conductive fine particles are dispersed in an organic solvent, and may contain substances other than the organic solvent and the conductive fine particles. The organic solvent is not particularly limited, and various organic solvents can be used.
Examples of the organic solvent include aromatic carbon such as benzene hydrocarbon such as benzene, toluene, o-xylene, m-xylene, p-xylene, mixed xylene, ethylbenzene, hexylbenzene, dodecylbenzene, and phenylxylylethane. Hydrogens: paraffinic hydrocarbons such as n-hexane and n-decane, isoparaffinic hydrocarbons such as Isopar (Isopar, manufactured by Exxon Chemical), olefinic hydrocarbons such as 1-octene and 1-decene, cyclohexane, decalin Aliphatic hydrocarbons such as naphthenic hydrocarbons such as: kerosene, petroleum ether, petroleum benzine, ligroin, industrial gasoline, coal tar naphtha, petroleum naphtha, solvent naphtha and other petroleum and coal derived hydrocarbon mixtures; dichloromethane, chloroform , Carbon tetrachloride, 1,2-di Loroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichlorofluoroethane, tetrabromoethane, dibromotetrafluoroethane, tetrafluorodiiodoethane, 1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, Halogenated hydrocarbons such as trichlorofluoroethylene, chlorobutane, chlorocyclohexane, chlorobenzene, o-dichlorobenzene, bromobenzene, iodomethane, diiodomethane, iodoform; esters such as ethyl acetate and butyl acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Ketones; alcohols such as methanol, ethanol, isopropanol, octanol, methyl cellosolve; dimethyl silicone oil, methyl Silicone oils such as E alkenyl silicone oil; fluorine-based solvents hydrofluoroether like; carbon disulfide and the like are preferable. These organic solvents may be used alone or in combination of two or more.

As the organic solvent, a hydrophobic organic solvent is preferable. By using a hydrophobic organic solvent, water droplets can be taken into the organic solvent dispersion in a more stable form when placed in a humidified atmosphere in the self-assembly step described later. The organic solvent is preferably a nonpolar organic solvent. By being nonpolar, it becomes difficult to dissolve in water, which is a polar molecule, so that the form of water droplets taken into the coating film can be more suitably maintained. Nonpolar organic solvents include aromatic hydrocarbon solvents having about 6 to 10 carbon atoms such as benzene, toluene, xylene, hexane and cyclohexane; halogenated hydrocarbon solvents such as chloroform and dichloromethane; aliphatic hydrocarbon solvents A solvent etc. can be used preferably. Benzene, toluene, hexane, cyclohexane and the like are more preferable from the viewpoint of the evaporation rate of the organic solvent and the solubility of water, that is, from the viewpoint that the evaporation rate is relatively fast, water droplets are easily condensed, and are not easily mixed with water. The organic solvent may be a mixed solvent of a polar solvent and a nonpolar solvent. For example, a mixed solvent of an aromatic hydrocarbon solvent and a ketone solvent, a mixed solvent of an aromatic hydrocarbon and an amide solvent, or the like may be used.

The specific gravity of the organic solvent is preferably not more than the specific gravity of water. When the specific gravity of the organic solvent is larger than the specific gravity of water, water droplets condensed on the surface of the coating film may not be taken into the organic solvent dispersion when performing the self-assembly process described later. Specifically, the specific gravity of the organic solvent is preferably 1.00 or less, more preferably 0.95 or less, and still more preferably 0.90 or less at room temperature (20 ° C.). .

The viscosity of the organic solvent is preferably 2 mPa · s or less at room temperature (20 ° C.). When taking water into the coated organic solvent dispersion, if the viscosity of the organic solvent is too high, water droplets may not be taken in sufficiently.

The organic solvent dispersion preferably contains a fine particle dispersant that promotes dispersion of fine particles such as conductive fine particles in the organic solvent. By containing the fine particle dispersant, the fine particles can be prevented from aggregating in the organic solvent, and the organic solvent dispersion can be made more uniform.
The fine particle dispersant is not particularly limited as long as fine particles such as conductive fine particles can be dispersed in an organic solvent. For example, amine compounds such as octylamine, hexylamine and oleylamine; dodecanethiol and the like Sulfur compounds; carboxylic acid compounds such as oleic acid; and the like. Among these, if it is an amine compound, it becomes easy to be washed away in the step of allowing a solvent solution containing an organic solvent to act on the film having the above-described pattern, and it is expected that the effect of this step will be exhibited more remarkably. Therefore, it is preferable.
As said fine particle dispersing agent, these may be used independently and 2 or more types may be used.

The content of the fine particle dispersant is preferably 0.001 to 5% by mass with respect to 100% by mass of the organic solvent dispersion. If the amount is less than the above range, the aggregation of the fine particles in the organic solvent dispersion may not be sufficiently prevented. On the other hand, if the amount is larger, the conductivity of the formed conductive film may not be expressed. . More preferably, it is 0.01-3 mass% as content of a fine particle dispersing agent.

The organic solvent dispersion preferably contains an amphiphilic compound for water and the organic solvent. By containing the amphiphilic compound, when performing the self-assembly process described later, it becomes easy to maintain the shape of the water droplets to be incorporated into the coating film by a surface active function, for example, In addition, aggregation of water droplets can be controlled, and it becomes easy to form a mesh of a conductive film. The amphiphilic compound may be an amphiphilic low molecular compound or an amphiphilic polymer compound, and is not particularly limited. As a form that can further exhibit the surface active function, an amphiphilic polymer compound is preferable. In order to suitably maintain the form of water droplets taken into the coating film in the organic solvent dispersion, it is preferable to use a compound having a surface active function. That is, it is one of the preferable embodiments of the present invention that the organic solvent dispersion contains a compound having a surface active function.

The content of the amphiphilic compound is preferably 0.001 to 25% by mass with respect to 100% by mass of the organic solvent dispersion. By setting the content in such a range, the form of water droplets taken into the coated organic solvent dispersion can be more stably maintained in the self-assembly process performed when forming a film having a pattern. It becomes possible to do. When the amount is less than 0.001% by mass, it is difficult to grow and transport water droplets on the surface of the coating film, and the aperture ratio may be lowered. If it exceeds 25% by mass, water droplets aggregate on the surface of the coating film, and there is a possibility that pores are not sufficiently formed. Moreover, there exists a possibility that electroconductivity may become difficult to express. More preferably, it is 0.001-15 mass% as content of an amphiphilic compound, More preferably, it is 0.001-5 mass%, Most preferably, it is 0.01-1 mass%.

The amphiphilic compound is preferably a compound having both a hydrophilic group and a hydrophobic group. The amphiphilic compound is expected to have an effect of preventing water droplets attached to the organic solvent dispersion coated on the substrate from fusing each other in the self-assembly process described later. The amphiphilic compound is not particularly limited as long as it is a compound having an affinity for both water and an organic solvent. Examples of the hydrophobic group include hydrocarbons having 5 to 20 carbon atoms. And nonpolar groups such as a group, a phenyl group, and a phenylene group. Examples of the hydrophilic group include a hydroxyl group, a carboxyl group, an amino group, a carbonyl group, a sulfo group, an ester group, an amide group, an ether group, and a pyridine group.

Examples of the amphiphilic compound include anionic surfactants such as sodium alkyl sulfate, cationic surfactants such as alkyl ammonium chloride, polyoxyethylene alkyl ether, sorbitan fatty acid ester, sucrose fatty acid ester, glycerin fatty acid ester, poly Nonionic surfactants such as glycerin fatty acid esters, alkylamines such as octylamine and dodecylamine, amphiphilic polymers and the like can be mentioned. From the viewpoint of solubility in organic solvents and water, nonionic surfactants and amphiphilic polymers are preferred. These amphiphilic compounds may be used alone or in combination of two or more.

As the amphiphilic polymer, a polymer having polyacrylamide as a main chain skeleton, a hydrophilic group and a hydrophobic group in the side chain, and co-polymerization of hydrophobic (meth) acrylate and hydrophilic (meth) acrylate Polymer, copolymer of styrene and hydrophilic (meth) acrylate, copolymer of styrene and 2-vinylpyridine, octadecyl isocyanate modified polyethyleneimine (Epomin RP-20, manufactured by Nippon Shokubai Co., Ltd.) A polymer having a hydrophilic group and having a hydrophobic group in the side chain, a block copolymer of polyethylene glycol and polypropylene glycol having a hydrophobic group and a hydrophilic group, or sodium of dichlorodiphenylsulfone and bisphenol A It is obtained by polycondensation with a salt, and a diphenylenedimethylmethylene group which is a hydrophobic group and a divalent group which is a hydrophilic group in the main chain skeleton. Polysulfone or the like having a Enirensuruhon group.

The amphiphilic polymer preferably has a weight average molecular weight of 5,000 to 500,000. When an amphiphilic polymer having a weight average molecular weight of 5,000 or more and 500,000 or less is used, a pattern structure is less likely to be collapsed during solvent evaporation when a film having a pattern is formed by a self-assembly process described later. More preferably, the weight average molecular weight is 10,000 or more and 300,000 or less, still more preferably 50,000 or more and 200,000 or less, and particularly preferably 90,000 or more and 100,000 or less.
The number average molecular weight of the amphiphilic polymer is preferably 3000 or more and 500,000 or less. When the number average molecular weight is 3000 or more and 500,000 or less, the pattern structure is less likely to collapse during solvent evaporation when a film having a pattern is formed by a self-assembly process described later. The number average molecular weight of the amphiphilic polymer is more preferably 5000 or more and 300,000 or less, further preferably 10,000 or more and 200,000 or less, and 20,000 or more and 100,000 or less. It is particularly preferred.
The weight average molecular weight (Mw) and the number average molecular weight (Mn) are, for example, gel permeation chromatography (GPC) HLC-8120 (manufactured by Tosoh Corporation) as a measuring device, and TSK-GEL GMHXL-L (Tosoh Corporation) as a column. Can be measured as a molecular weight in terms of polystyrene.

Examples of the polymer having polyacrylamide as the main chain skeleton and hydrophilic groups and hydrophobic groups in the side chains include, for example, the following general formula (3):

(Wherein n and m are the same or different and represent the number of repeating structural units) (dodecylacrylamide) _n- (ω-carboxyhexylacrylamide) _m -random copolymer (hereinafter, “ Also referred to as “CAP”).
In the formula, the ratio of n to m (n / m) is preferably 1 to 15, more preferably 2 to 12, and still more preferably 3 to 10.

Examples of the hydrophobic (meth) acrylate include normal hexyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, heptyl (meth) acrylate, benzyl (meth) acrylate, octyl (meth) acrylate, and 2-ethylhexyl. (Meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like.

Examples of the hydrophilic (meth) acrylate include (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and dimethylaminoethyl (meth) acrylate. , Diethylaminoethyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, glycidyl (meth) acrylate, 2- (meth) acryloyloxyethyl Acid phosphate, caprolactone-modified (meth) acrylate and the like.

Further, a hydrophobic radical polymerizable monomer such as hydrophobic (meth) acrylamide or styrene is used instead of the hydrophobic (meth) acrylate, and hydrophilic (meth) acrylamide, N is used instead of the hydrophilic (meth) acrylate. -Hydrophilic radically polymerizable monomers such as vinylpyrrolidone may be used.
Each of the hydrophobic (meth) acrylate and the hydrophilic (meth) acrylate may be used alone or in combination of two or more. Moreover, a different component may be included.

The organic solvent dispersion preferably contains a binder. Adhesiveness with a board | substrate improves that it contains a binder. The binder is not particularly limited as long as it is a polymer that dissolves in an organic solvent, and examples thereof include urethane resins, acrylic resins, polyester resins, polyacrylamides, polyalkylene glycol polymers, and polystyrene.
These binders may be used independently and may use 2 or more types together.

The binder preferably has a weight average molecular weight of 5000 or more and 500,000 or less. When the weight average molecular weight of the binder is within such a range, the adhesion between the coated organic solvent dispersion and the substrate can be made sufficient. More preferably, the weight average molecular weight is 10,000 or more and 300,000 or less, still more preferably 50,000 or more and 200,000 or less, and particularly preferably 90,000 or more and 100,000 or less.
In addition, the weight average molecular weight of a binder can be measured similarly to the weight average molecular weight of the amphiphilic polymer mentioned above, for example.

The content of the binder is preferably 0.001 to 50% by mass with respect to 100% by mass of the organic solvent dispersion. By setting it as content of such a range, the adhesiveness of the coated organic solvent dispersion and a board | substrate can be made sufficient. Further, as described above, when an amphiphilic polymer is used as a binder, the content in such a range allows the coated organic solvent dispersion in the coated organic solvent dispersion. It is possible to more stably maintain the form of water droplets taken into the water. When the content is less than 0.001% by mass, it is difficult to grow and transport water droplets on the surface of the coating film when the self-assembly process described later is performed, and the aperture ratio may be lowered. If it exceeds 50% by mass, the coatability may be deteriorated, and the aperture ratio may be lowered without sufficient growth of water droplets.
More preferably, it is 0.001-25 mass% as content of a binder, More preferably, it is 0.005-25 mass%.

The organic solvent dispersion preferably has a water content of 10% by mass or less before coating. When a large amount of water is contained in the organic solvent dispersion before coating, the water in the organic solvent dispersion becomes large water droplets due to surface tension, and when a film having a pattern is formed by a self-assembly process described later. There is a possibility that the mesh cannot be made fine. More preferably, the water content before coating is 5% by mass or less.

The organic solvent dispersion is applied to a substrate. The said board | substrate is not specifically limited, What is necessary is just to be able to apply the organic solvent dispersion on the surface. As the substrate, for example, various substrates such as a glass substrate, a plastic substrate, a single crystal substrate, a semiconductor substrate, and a metal substrate can be used. When used for a display such as electronic paper (digital paper), a transparent substrate such as a glass substrate or a transparent plastic substrate is preferably used as the substrate. The transparent substrate is a substrate having a high visible light transmittance. For example, the visible light transmittance of a wavelength of 400 to 700 nm is preferably 50% or more. More preferably, the transmittance is 70% or more, and more preferably 80% or more. Use of a glass substrate or a plastic substrate is also preferable from the viewpoint of cost reduction. In the case of using as a display device such as electronic paper, it is also a preferable form to use a flexible substrate. Examples of the plastic substrate include ester films such as polyethylene terephthalate and polyethylene naphthalate; acrylic films; cycloolefin films; olefin films; resin films such as polyamide, polyphenylene sulfide, and polycarbonate.

The substrate on which the organic solvent dispersion is applied is preferably a substrate having a hydrophilic surface. Since the surface of the substrate is hydrophilic, water droplets can be easily brought into contact with the substrate, the penetration rate of the pores can be increased, and formation of an extra polymer / particle film on the bottom surface of the pores can be prevented. When a film having a pattern is formed by a self-assembly process described later, the shape of the pores can be made into a conductive film having a high aperture ratio. The substrate having a hydrophilic surface preferably has a water contact angle of 90 ° or less. By being 90 ° or less, the shape of the water droplets taken into the organic solvent dispersion can be adjusted, and the shape of the pores can be made to have a high aperture ratio. More preferably, it is 60 degrees or less as an upper limit of the contact angle with respect to water, More preferably, it is 30 degrees or less.

It is preferable that the substrate on which the organic solvent dispersion is applied has been subjected to a hydrophilic treatment on the substrate surface. According to this, water droplets taken into the organic solvent dispersion can be held in a suitable shape. Further, the shape of the conductive film can be further controlled by controlling the hydrophilicity of the substrate surface. The hydrophilic treatment method is not particularly limited, but for example, a method of immersing in an alkaline solution is preferable. Although it does not specifically limit as an alkaline solution, A potassium hydroxide solution, a sodium hydroxide solution, etc. can be used preferably. Specifically, a saturated potassium hydroxide ethanol solution or the like can be preferably used. Examples of the hydrophilic treatment method include corona discharge treatment, plasma treatment, and UV-ozone treatment. It is preferable to select a preferable method as appropriate depending on the type of the substrate, the type of the organic solvent dispersion, and the like. Moreover, the value of the preferable contact angle mentioned above can be used for the contact angle of the board | substrate by hydrophilization.

About the process (self-assembling process) of forming a film having a pattern by evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film, which is performed in the method for producing a conductive film of the present invention explain.
According to the self-organizing step, water droplets generated by condensation can be taken into the coating film while the organic solvent is evaporated. Then, the organic solvent evaporates and the taken water droplets are dried, so that a hole corresponding to the taken water droplets can be formed. Thereby, the mesh-like line part formed from electroconductive fine particles and the void | hole part are formed. Thus, a conductive film having a network pattern can be manufactured by a self-assembly process, and a network conductive film excellent in conductivity and light transmission can be manufactured easily and at low cost. It becomes possible. That is, the conductive film formed by the method for producing a conductive film of the present invention is preferably a mesh-like conductive film formed by a mesh-like line portion and a hole portion.

In the step of evaporating the organic solvent while condensing the coated organic solvent dispersion on the surface of the coating film, the dew condensation on the surface of the coating film is caused by the humidity near the coating film surface and the atmosphere near the coating film surface. This can be done by adjusting the temperature difference from the surface of the coating film. That is, the conditions for condensation on the coating film surface may be used. In the present invention, a network-like conductive part and a hole part are formed on the surface of the coating film by the self-assembly process, and this is because of a mechanism as shown in FIG. It is clear from a technical viewpoint that the organic solvent is evaporated while condensation is formed on the surface of the coating film.
From the above, it can be said that the self-organization method is a step of evaporating the applied organic solvent under the condition that condensation occurs on the surface of the coating film. The conditions under which condensation occurs on the surface of the coating film are, for example, conditions in which the dew point of the atmosphere for evaporating the organic solvent is higher than the temperature of the coating film surface. The method for causing dew condensation is not particularly limited. For example, the method for cooling the surface of the coating film to a dew point below the atmosphere for evaporating the organic solvent, or the atmosphere for evaporating the organic solvent as a humidified atmosphere. A method of making the dew point of the atmosphere higher than the temperature of the coating film surface is suitable. These methods may be used in one method or a combination of a plurality of methods. By combining a plurality of methods, the conditions for evaporating the organic solvent can be controlled more precisely, and the form of the mesh pattern of the conductive film can be adjusted.

The method for cooling the temperature of the coating film surface below the dew point of the atmosphere for evaporating the organic solvent is not particularly limited, but a method for forcibly cooling the coating film using a cooling element or the like, an organic solvent And a method of lowering the surface temperature of the coating film by latent heat of evaporation. Moreover, as a method of forcibly cooling the coating film using a cooling element or the like, it is also preferable to cool the temperature of the coating film surface by cooling the substrate coated with the organic solvent dispersion. By cooling by such a method, the difference between the temperature of the coating film surface and the temperature of the atmosphere in which the organic solvent is evaporated increases, so that condensation can be more easily generated. That is, it is preferable to make the temperature of the coating film surface lower than the temperature of the atmosphere in which the organic solvent is evaporated. For example, a method of cooling the substrate coated with the organic solvent dispersion by using a cooling device such as a Peltier device is one of preferable methods. With this method, temperature control of the coating film surface and control of the atmosphere around the coating film for evaporating the organic solvent can be performed independently, so that more precise condition setting can be performed. By adjusting the conditions more, the shape, transmittance, conductivity, etc. of the manufactured conductive film can be controlled, so it is possible to form a conductive film in a suitable form according to various applications. It becomes.

In order to cause condensation on the coating film surface when the organic solvent is evaporated, a humidified atmosphere is preferable. That is, the step of evaporating the organic solvent is preferably a step of evaporating the organic solvent in a humidified atmosphere. By setting the humidified atmosphere, dew condensation is likely to occur on the surface of the organic solvent dispersion. As a method of setting the atmosphere at the time of evaporating the organic solvent as a humidified atmosphere and making the dew point higher than the temperature of the coating film surface, a method of humidifying the entire surroundings where the organic solvent is evaporated, a humidified gas is blown on the coating film surface. The attaching method is suitable. By using a humidified atmosphere, condensation tends to occur on the surface of the coating film. When the humidified gas is sprayed onto the surface of the coating film, the shape and amount of water droplets taken into the coating film changes depending on the spraying speed, etc., so the organic solvent is evaporated by adjusting the spraying speed. The conditions to be adjusted can be adjusted. Thereby, the shape of the conductive film can be controlled, and its characteristics (light transmittance, conductivity, etc.) can be improved. The humidified atmosphere may be any atmosphere as long as the humidity is sufficient to cause condensation on the surface of the coating film of the organic solvent dispersion, that is, the same conditions as the humidification, The step of evaporating the organic solvent may be performed under a high humidity environment.

The humidified atmosphere preferably has a relative humidity of 50% or more. When the relative humidity is as high as 50% or more, condensation tends to occur on the surface of the coating film, and the conductive film can be efficiently produced. The relative humidity is more preferably 55% or more, and still more preferably 60% or more.

The upper limit of the wind speed for blowing the humidified gas is preferably 5 m / s (300 m / min) or less as the flow velocity. When the humidified gas is blown at a flow rate exceeding 5 m / s, the shape of the coated organic solvent dispersion is changed by blowing the humidified gas, and the film shape after drying the organic solvent is changed to the desired shape. May not be able to be retained. The flow rate that is more preferable as the upper limit of the wind speed for blowing the humidified gas is 3 m / s (180 m / min) or less, and more preferably 1 m / s (60 m / min) or less. Moreover, as a minimum of the said wind speed, it is preferable that it is 0.02 m / min or more. When the wind speed is 0.02 m / min or less, water droplets may not be sufficiently taken into the coated organic solvent dispersion. The flow rate more preferable as the lower limit of the wind speed is 0.1 m / min, more preferably 0.2 m / min or more, and particularly preferably 0.4 m / min or more. The upper limit of the time for blowing the humidified gas is preferably within one hour from the viewpoint of productivity. More preferably, it is within 40 minutes, and more preferably within 30 minutes. The lower limit of the time for blowing the humidified gas is preferably 1 minute or longer. If it is less than 1 minute, the organic solvent may not be sufficiently evaporated, and water droplets may not be sufficiently taken into the organic solvent dispersion. More preferably, it is 5 minutes or more, More preferably, it is 10 minutes or more. For example, a suitable time is about 20 minutes (15 to 25 minutes). The relative humidity of the humidified gas to be blown is also preferably 50% or more, more preferably 55% or more, and particularly preferably 60% or more, as described above.

Here, a method of manufacturing a film having a mesh pattern by the self-assembly process will be described with reference to FIGS. FIG. 1-2 is a flowchart showing a process of evaporating the organic solvent while the coated organic solvent dispersion is condensed on the coating film surface. As shown in FIG. 1-2 (a), the organic solvent dispersion (hereinafter also referred to as “coating film”) applied to the substrate 11 is a method for cooling the substrate 11 on which the coating film 12 is formed, or humidification. By setting it as the conditions which cause dew condensation on the coating film surface by the method of blowing gas, dew condensation occurs on the surface of the coating film as shown in FIG. The water droplet 13 generated by the condensation is taken into the coating film 12 as shown in FIGS. 1-2 (c) and 1-2 (d). In addition, the coated organic solvent dispersion evaporates with time and becomes thinner. Then, the organic solvent and the water droplets taken in by the humidified atmosphere evaporate, and as shown in FIG. It will be formed. In this way, a mesh pattern is formed. FIG. 2 is a schematic plan view showing the form of the film after the organic solvent evaporates, in which a mesh-like line portion 15 including a metal is formed around the formed hole portion 14. Thus, a film having a mesh pattern is formed.
Also, as shown in FIG. 3, a method of evaporating an organic solvent by cooling a substrate 21 and a coating film 22 using a Peltier element 20 and spraying a humidified gas on a coated organic solvent dispersion. Is one of the preferred embodiments of the method for producing a conductive film of the present invention. That is, the manufacturing method is preferably a manufacturing method including a step of cooling the substrate and the coating film, blowing a humidified gas onto the coating film, and evaporating the organic solvent while causing condensation on the coating film surface.

The method for producing the conductive film preferably further includes a step of performing electroless plating after the step of evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film. Thus, by performing electroless plating, the conductivity of the obtained conductive film can be further improved.

The present invention is also a conductive film manufactured by the above manufacturing method. By being manufactured by the above-described manufacturing method, the conductive film becomes a network-like conductive film formed by a mesh-like line portion and a void portion of a conductive substance, and is thus conductive and light-transmissive. It can be set as the transparent conductive film excellent in.
Note that the arrangement form of the mesh-like line portions and the hole portions in the conductive film having a mesh-like pattern may be random or regularly arranged. In addition, there may be some meshes where large and small meshes are mixed, but some meshes may be cut off, but overall, it is evaluated that a mesh-like structure is recognized in a micro technical field. It is desirable that That is, it is only necessary to confirm a network structure by observing with a microscope. The network structure is preferably formed on the entire surface of the conductive film, but may be appropriately set according to the use for which the conductive film is used, and may be partially as long as the function as the conductive film can be exhibited. It may be. Other preferred mesh-like forms will be described later. Here, the term “random” means that the mesh-like line portions and the hole portions are not arranged based on a certain rule.
Hereinafter, among the conductive films of the present invention, the form of a conductive film having a mesh pattern that has particularly excellent conductivity and light transmittance will be described. In addition, as a more preferable form of the electroconductive film manufactured by the said manufacturing method, it is the same as that of the preferable form of the mesh-shaped electroconductive film demonstrated below.

As the form of the mesh-like conductive film, the average area of the pores is preferably 400 μm ² or less, and the line width of the mesh-like line part is preferably 5 μm or less. Since the average area of the pores is small and the line width of the mesh-like line portion is narrow, it is possible to form a mesh-like conductive film having high light transmittance and high uniformity. The average area of the pores is more preferably 300 μm ² or less, still more preferably 200 μm ² or less, and particularly preferably 100 μm ² or less. In addition, the hole portion preferably has an average maximum ferret diameter of 20 μm or less, and more preferably 10 μm or less. The aperture ratio due to the pores is preferably 60% or more, whereby a conductive film with improved light transmittance can be obtained. The aperture ratio due to the voids is more preferably 65% or more, further preferably 70% or more, particularly preferably 80% or more, and most preferably 90% or more. The line width of the mesh-like line portion is more preferably 2 μm or less, and further preferably 1 μm or less. The maximum ferret diameter is the maximum between two parallel lines drawn so as to be in contact with the outline of each hole, and is called the maximum ferret diameter. The average maximum ferret diameter is measured for each hole. The average of the maximum ferret diameter is called the average maximum ferret diameter.

The present invention further relates to a network-like conductive film formed by a mesh-like line portion and a hole portion of a conductive substance, and the conductive film has an average area of the hole portion of 400 μm ² or less. Also, the conductive film having a line width of the mesh-like line portion of 5 μm or less. Since the average area of the pores is small and the line width of the mesh line portion is narrow, it is possible to form a mesh-like transparent conductive film having high light transmission and high uniformity. For example, when used for electronic paper or the like, a voltage can be uniformly applied to microcapsules for display. When the mesh is wide (the area of the pores is large), when the voltage is applied by a conductive film to change the color of the microcapsules, the pores must be fine if the mesh is not fine. The entire microcapsule is contained in the part, and no voltage is applied to such a capsule. Further, the finer mesh makes the conductivity more uniform. According to this, for example, when used for a touch panel, the accuracy of position recognition increases. Such a network-like conductive film can be formed using the above-described method for manufacturing a conductive film. The arrangement form of the mesh-like line portions and the hole portions in the conductive film may be random or regularly arranged. For example, when forming a mesh-like conductive film, in order to make the mesh finer, it is easier to manufacture if it is random. One.

In the conductive film, the average area of the pores is 400 μm ² or less, and the line width of the mesh-like line part is 5 μm or less, which means that the mesh of the conductive film is fine. By having a fine mesh, it is possible to have a uniform conductivity within the surface of the conductive film. When the average area of the pores exceeds 400 μm ² , the in-plane uniformity of the conductive film is not sufficient, and for example, there is a possibility that variations in light transmission and conductivity occur. In addition, as described above, when used for a display such as electronic paper, there is a possibility that the function as a conductive film may be insufficient due to the occurrence of a portion where no voltage is applied. The average area of the pores is more preferably 300 μm ² or less, still more preferably 200 μm ² or less, and particularly preferably 100 μm ² or less. In addition, the hole portion preferably has an average maximum ferret diameter of 20 μm or less, and more preferably 10 μm or less. The line width of the mesh-like line portion is 5 μm or less, and the narrow line width can suppress, for example, moire that may occur in a display or the like. When the line width of the mesh-like line portion exceeds 5 μm, the aperture ratio becomes small and the light transmittance may not be sufficient. The line width of the mesh-like line portion is more preferably 2 μm or less, and further preferably 1 μm or less. As described above, by controlling the average area of the hole portions and the line width of the mesh-like line portions, the conductivity and light transmittance of the conductive film can be controlled to more preferable values.

The conductive film preferably has an aperture ratio of 60% or more due to the pores. Since the light transmittance can be improved by increasing the aperture ratio, it can be suitably used for a display such as electronic paper. If it is less than 60%, sufficient light transmittance cannot be obtained, and there is a possibility that sufficient characteristics as a conductive film having transparency cannot be exhibited. The opening ratio due to the pores is more preferably 65% or more, further preferably 70% or more, particularly preferably 80% or more, and most preferably 90% or more.
The aperture ratio, line width, average area of pores, and average maximum ferret diameter can be determined by the following methods.

<How to find the aperture ratio, line width, average area of pores, average maximum ferret diameter>
The surface of the conductive film was observed with an ultrahigh resolution field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation) at a magnification of 1000 times, and the observed image was image processing software (Image-Pro Plus ver. 4). 0.0, manufactured by Media Cybernetics, USA), the following methods are used to determine the aperture ratio, line width, average area of pores, and ferret diameter of the conductive film.

The image observed with a microscope (this is called the “original image”) is binarized into black and white using the above-mentioned image processing software so that the conductive part is black and the other part (mesh opening) is white. To do. At this time, as the binarization threshold value, the peak values of white and black are obtained from the tone histogram, and set to the intermediate value. Next, black and white inversion processing of the binarized image is performed (this image is referred to as “binarized image”). At this time, the area ratio of the black portion with respect to the entire area is obtained and set as the aperture ratio.

Moreover, the area of the white part of a binarized image is calculated | required and let this be the area (S) of an electroconductive part. Next, thinning processing of the binarized image is performed (this image is referred to as “thinning processing image”). The area of the white part of the thinned image is obtained, and this is defined as the length (L) of the conductive part. Using the values of S and L obtained above, the line width of the conductive portion is obtained by the following formula (1).
Line width of conductive part = S / L (1)

Subsequently, the black portion of the binarized image is extracted (this image is referred to as “extracted image”). During extraction, voids on the boundary are excluded. In addition, pores having an area of 1 μm ² or less are also excluded. At this time, the area of each element and the maximum ferret diameter are measured and averaged to obtain the average area of the hole portion and the average maximum ferret diameter of the hole portion, respectively.

The thickness of the mesh line portion is preferably 200 nm or more. When the thickness is 200 nm or more, sufficient conductivity can be obtained even if the line width is narrowed. When the film thickness of the conductive film is less than 200 nm, the conductivity is low, and the characteristics as the conductive film may not be sufficiently exhibited. More preferably, the thickness of the mesh line portion is 1 μm or more. In addition, the thickness of a mesh line part is calculated | required by measuring the maximum film thickness, for example, can be measured by using a laser microscope. As a measurement method, the coating film was observed at a magnification of 50 times with a laser microscope (VK-9700, manufactured by Keyence Corporation), the maximum step of the coating film was measured at 10 locations from the observed image, and the averaged value was measured as conductivity. The maximum film thickness.

The conductive film of the present invention preferably has a light transmittance of 20% or more for visible light (wavelength: 400 to 700 nm). By increasing the light transmittance, for example, it can be suitably used for a display device such as electronic paper. The light transmittance is more preferably 40% or more, still more preferably 60% or more, and particularly preferably 80% or more. The light transmittance can be measured for light having a wavelength of 300 to 800 nm using a spectrophotometer (trade name “V-530”, manufactured by JASCO Corporation).

The conductive film of the present invention preferably has a total light transmittance of 20% or more. When the total light transmittance is 20% or more, for example, it can be suitably used for a display device such as electronic paper. More preferably, the total light transmittance is 40% or more, still more preferably 50% or more, and particularly preferably 60% or more. Most preferably, it is 75% or more.
In addition, the said total light transmittance can be measured based on JISK7361-1 using haze meter NDH5000 (made by Nippon Denshoku Industries Co., Ltd.).

The conductive film of the present invention preferably has a surface resistivity of 10 ¹² Ω / □ or less. Since it has sufficient electroconductivity as it is such surface resistivity, it can be used suitably, for example with respect to display apparatuses, such as electronic paper. More preferably, it is 10 ⁸ Ω / □ or less, more preferably 10 ⁷ Ω / □ or less, and particularly preferably 10 ⁶ Ω / □ or less. Most preferably, it is 10 ⁵ Ω / □ or less.
In addition, in the conductive film having the above-described mesh pattern, particularly when the aperture ratio due to the holes is high, the area of the mesh line portion is small and compared with the conductive film having the same film thickness with a low aperture ratio. As a result, the resistivity of the conductive film increases. Therefore, the area of the mesh line portion is preferably an area that can ensure sufficient conductivity. The preferred area of the mesh line portion varies depending on the film thickness and area of the conductive film, the metal material constituting the conductive film, and the like. For example, the surface resistivity in the plane of the conductive film is 10 ¹² Ω / □ or less. It is preferable to set the area of the mesh line portion so that According to this, the surface resistivity of the conductive film is more preferably 10 ⁸ Ω / □ or less, further preferably 10 ⁷ Ω / □ or less, and particularly preferably 10 ⁶ Ω / □ or less. is there. Most preferably, it is 10 ⁵ Ω / □ or less.
The surface resistivity can be measured by a four-terminal four-probe method using a resistivity meter Lorester-GP (manufactured by Mitsubishi Chemical Analytech, probe: ASP probe).

The conductive film of the present invention preferably has a haze of 40% or less. By suppressing the haze to a low level, for example, when used for a display device such as electronic paper, the image clarity can be improved. The haze is more preferably 30% or less, still more preferably 25% or less, and particularly preferably 20% or less.
In addition, the said haze can be measured based on JISK7361-1 using haze meter NDH5000 (made by Nippon Denshoku Industries Co., Ltd.).

The use of the conductive film is not particularly limited, and can be used for any application that requires conductivity. For example, it can be used as an electromagnetic wave shielding film (EMI shield film) used for a plasma display or the like, and can also be used as an electrode used for a display device of electronic paper (digital paper) or a liquid crystal display device. It can also be used for touch panels and the like.
Thus, the present invention is also a conductive film used for digital paper.

The present invention is also a conductive film manufacturing apparatus for manufacturing a conductive film by the above manufacturing method. That is, an apparatus for manufacturing a conductive film having a pattern by applying an organic solvent dispersion containing conductive fine particles to a substrate, wherein the manufacturing apparatus applies the organic solvent dispersion after applying the organic solvent dispersion to the substrate. A means for forming a film having a pattern by evaporating the organic solvent while the processed organic solvent dispersion is condensed on the surface of the coating film; and a means for allowing a solvent solution containing the organic solvent to act on the film having the pattern. An apparatus for producing a conductive film is also one aspect of the present invention.

The manufacturing apparatus of the present invention forms a film having a pattern by evaporating the organic solvent while condensing the coated organic solvent dispersion on the surface of the coating film, a part for performing the step of applying the organic solvent dispersion to the substrate Including a part for performing a process and a part for performing a process for allowing a solvent solution containing an organic solvent to act on a film having a pattern, as long as a part for performing these processes is included, including a part for performing other processes. May be. In particular, a high-quality conductive film can be obtained by removing impurities, gel-like foreign matters and aggregated foreign matters contained in the organic solvent dispersion solution by providing a filtration device so that the organic solvent dispersion is filtered before being applied. Preferred for manufacturing.

In the part of performing the step of applying the organic solvent dispersion to the substrate, as a method of applying the organic solvent dispersion to the substrate, any of the slide method, the extrusion method, the bar method, and the gravure method may be used. preferable. In order to produce a long conductive film, a long substrate is preferable, and for continuous production, a web-like substrate is preferably used. In addition, a web-like substrate is preferably in roll form for transportation and handling, and a web-like substrate on which a conductive film is formed can also be carried and handled by making it into a roll form with a take-up roller or the like. Is preferable.

The part of performing the step of forming a film having a pattern by evaporating the organic solvent while condensing the coated organic solvent dispersion on the coating film surface is formed by applying the organic solvent dispersion on the substrate. In an atmosphere adjusted so that the dew point of the gas in the vicinity of the film is higher than the surface temperature of the film, a gas wind is sent to the surface of the coating film of the organic solvent dispersion to evaporate the organic solvent and Adjust the part that performs the process of forming droplets on the coating surface by condensation (condensation process) and the film that has droplets on the surface so that the dew point of the gas near the coating film is lower than the surface temperature of the film It is preferable to include a portion for performing a step of evaporating the droplets (droplet evaporation step) by being placed in the atmosphere. Moreover, air is preferable as the gas sprayed onto the coating film.

In the dew condensation step, the difference between the surface temperature of the coating film and the dew point of the gas in the vicinity of the coating film is not particularly limited as long as droplets can be formed on the coating film surface. preferable. More preferably, it is 80 degrees C or less, More preferably, it is 70 degrees C or less. The variation of the surface temperature of the coating film immediately before the dew condensation process and the dew point of the dew condensation process is preferably ± 5% or less. More preferably, it is ± 3% or less, and still more preferably ± 2% or less.
When manufacturing using the moving web-like substrate, the moving speed of the web-like substrate is preferably 0.1 m / min to 100 m / min. More preferably, it is 0.1 m / min-80 m / min, More preferably, it is 0.1 m / min-60 m / min. The relative speed of the blown gas with respect to the moving speed of the web-like substrate is preferably 0.05 m / s or more. 1 m / s or more is more preferable. Moreover, 30 m / s or less is preferable, More preferably, it is 20 m / s or less. The relative speed variation is preferably ± 30% or less. More preferably, it is ± 20% or less, and still more preferably ± 10% or less. Thereby, the organic solvent can be sufficiently evaporated, droplets can be sufficiently formed on the surface of the coating film, and a film with stable quality can be formed.
Moreover, it is preferable that the air sent from the air blowing port in the dew condensation step is supplied from one direction at an angle such that the variation is within ± 20 ° with respect to the coating film, and further the moving direction of the web-like substrate More preferably, it is a parallel wind blowing toward When the wind is blown against the paint film as a head wind, it is difficult to control the speed of the wind when the relative speed between the wind and the paint film is low. There is a fear.

In the droplet evaporation step, the difference between the surface temperature of the coating film and the dew point of the gas in the vicinity of the coating film is not particularly limited as long as the droplets on the coating film surface can be evaporated. Is preferred. More preferably, it is 1 degreeC or more, More preferably, it is 2 degreeC or more. Moreover, it is preferable that it is 90 degrees C or less. More preferably, it is 80 degrees C or less, More preferably, it is 70 degrees C or less. Further, the variation of the surface temperature of the coating film immediately before the droplet evaporation step and the dew point of the droplet evaporation step are preferably ± 5% or less. More preferably, it is ± 3% or less, and still more preferably ± 2% or less.
In the droplet evaporation step, it is preferable to promote evaporation of the droplets by sending dry air to the coating film. In that case, it is preferable that the drying air is supplied from one direction at an angle that is within ± 20 ° with respect to the coating film, and is a wind that blows in parallel toward the moving direction of the coating film. More preferred.
As a method for controlling the surface temperature of the film in the dew condensation step and the droplet evaporation step, when a moving web-like substrate is used, a temperature controller is provided on a rotary roller in contact with the web-like substrate, A method of controlling the surface temperature of the film by controlling the temperature of the substrate can be used. In that case, for example, a liquid flow path through which the heat transfer medium flows can be provided inside the roller, and a method of feeding the temperature-controlled heat transfer medium can be used.

The part that performs the step of causing the solvent solution containing the organic solvent to act on the film having the pattern passes the film on which the pattern has been formed through the droplet evaporation step into the container containing the solvent solution containing the organic solvent. It is preferable that the portion has a structure. The method for allowing the film having a pattern to pass through a container containing a solvent solution containing an organic solvent is not particularly limited.

A schematic diagram of an example of the production apparatus of the present invention is shown in FIG.
In the conductive film manufacturing facility 100 of FIG. 7, a tank 102 containing an organic solvent dispersion 101 containing conductive fine particles is installed. The tank 102 is provided with a stirrer 103 having a stirring blade, and the conductive fine particles in the organic solvent dispersion 101 are kept in a dispersed state by rotating the stirring blade. The organic solvent dispersion 101 is sent by a pump 104 to a casting die 105 that coats the organic solvent dispersion on a substrate. The casting die 105 is provided above the web-like substrate 106, and the web-like substrate 106 is taken out from the delivery roller 108 and taken up by the take-up roller 112 through the rotation rollers 109 to 111. The temperature of the sending roller 108 and the rotating roller 109 is adjusted by a temperature controller 107, and thereby the temperature of the web-like substrate 106 between the sending roller 108 and the rotating roller 109 is controlled. The web-like substrate coated with the organic solvent dispersion from the casting die 105 includes a region 121 for performing the condensation process, a region 131 for performing the droplet evaporation process, and a solvent solution containing an organic solvent in a film having a pattern. After passing through a tank 141 containing a solvent solution containing an organic solvent to act, the film is wound around the winding roller 112 together with the conductive film 152 formed on the web-like substrate.

The inclination of the web-like substrate 106 between the delivery roller 108 and the rotating roller 109 is preferably within ± 10 ° with respect to the horizontal direction. Since the coated organic solvent dispersion is in a state of flowing from the time when the organic solvent dispersion 101 is coated on the substrate 106 by the casting die 105 until the dew condensation process, the inclination of the substrate 106 is increased. If the value is large, the organic solvent dispersion tends to have a lower inclination, and a coating film having a uniform thickness may not be formed. Variation in the thickness of the coating film can be suppressed by setting the inclination from the time when the organic solvent dispersion is applied on the substrate to the dew condensation process within ± 10 °. More preferably, the inclination is within ± 10 ° until the condensation process is completed.
By setting the inclination of the web-like substrate 106 between the delivery roller 108 and the rotating roller 109 to be within ± 10 ° with respect to the horizontal direction, the dew condensation process is performed after the organic solvent dispersion is applied on the substrate. In the meantime, the inclination of the substrate 106 can be within ± 10 ° with respect to the horizontal direction.

In the step of applying the organic solvent dispersion to the substrate, the organic solvent dispersion 101 containing conductive fine particles is applied from the casting die 105 onto the web-like substrate 106 taken out from the delivery roller 108 to form a coating film. It is formed.
In the region 121 where the dew condensation process is performed, wind is applied to the coating film whose temperature is controlled from the blower 122 for sending wind to the coating film 151 on the substrate, and droplets are formed on the coating film. The blower 122 preferably has a suction port that sucks the blown air together with the blower port, and may have a plurality of blower ports and suction ports. It is preferable that the air blower 122 is composed of a plurality of air blowers capable of independently controlling the temperature, humidity, air volume, and suction force of the wind. This makes it possible to control the conditions for blowing and suctioning according to the shape and amount of water droplets generated by condensation. A plurality of blowers may be installed in parallel to the moving direction of the substrate, or a plurality of fans may be installed perpendicular to the moving direction of the substrate. If a plurality of substrates are installed perpendicular to the moving direction of the substrate, the dew condensation condition can be controlled in the width direction of the coating film perpendicular to the moving direction of the substrate. Furthermore, in order to prevent the wind and dust from being mixed with the wind and reducing the cleanliness of the wind, the air blowing port and the suction port are preferably provided with a filter.

A dryer 132 is installed in the region 131 where the droplet evaporation step is performed. The dryer 132 sends drying air to the coating film 151 to dry the droplets formed on the coating film. To form a pattern. The dryer 132 preferably has a suction port for sending the drying air to the coating film 151 and sucking the air sent from the blower 122. Similarly to the blower 122, the dryer 132 can easily adjust the drying conditions of the coating film 151 by controlling the temperature and dew point of the wind. Similarly to the blower 122, the dryer 132 is preferably composed of a plurality of dryers capable of independently controlling the temperature, humidity, air volume, and suction force of the wind. May be provided in parallel with the moving direction of the substrate, or may be provided perpendicular to the moving direction of the substrate. In the case where a plurality of substrates are installed perpendicular to the moving direction of the substrate, the drying conditions can be controlled also in the width direction of the coating film perpendicular to the moving direction of the substrate. Further, in order to prevent the cleanliness of the wind from being deteriorated due to dust and dust mixed with the wind, it is preferable that the air blowing port and the suction port of the dryer include a filter.
In FIG. 7, the region 121 where the dew condensation process is performed and the region 131 where the droplet evaporation process is performed are separated, but these two regions may be in contact with each other. That is, you may use the air blower and dryer of the form with which the air blower 122 and the dryer 132 were united.

After a film having a pattern is formed through the region 131 where the droplet evaporation process is performed, the film 141 passes through a tank 141 containing a solvent solution 142 containing an organic solvent. Thereby, the solvent solution 142 containing the organic solvent can be allowed to act on the film having a pattern. In the apparatus of FIG. 7, there is only one rotating roller 110 in the solvent solution 142 in the tank 141, but as shown in FIG. 13, the rotating roller 702 is included in the solvent solution 742 containing the organic solvent. , 703 may be used, and when such a tank is used, an organic solvent is applied to the film having a pattern by adjusting the interval between two rotating rollers present in the solvent solution 742. It is possible to adjust the length of time for which the solvent solution containing is allowed to act. Moreover, the length of time for which the solvent solution containing the organic solvent is allowed to act on the film having the pattern can also be adjusted by adjusting the amount of the solvent solution in the tank. In addition, you may install an elastic roller in the position which opposes the rotation roller 109 of FIG. 7, and the rotation roller 701 of FIG. 13 across the film | membrane which has a pattern. In that case, it is preferable to install the elastic roller at a position where the rotation axes of the rotation rollers 109 and 701 and the elastic roller are horizontal.

As a part for performing the process from the coating of the organic solvent dispersion 101 on the substrate 106 by the casting die 105 to the droplet evaporation process, in addition to those shown in the conductive film manufacturing facility 100, FIG. As shown in FIG. 8, the web-like substrate 206 is moved by two rotating rollers 207 and 208, and a region 221 for performing a dew condensation process and a region 231 for performing a droplet evaporation process are provided separately above and below the web-like substrate. It is good also as a thing. In FIG. 8, 201 to 205 are the same as 101 to 105, respectively, and 222 and 232 are a blower and a dryer, respectively, similar to 122 and 132.
As yet another form, an organic solvent dispersion is applied on a plurality of substrates 302 installed on a moving belt 301 as shown in FIG. 9, and a dew condensation process or droplet evaporation is applied to a coating film 311 on the substrate. It is good also as a form of performing a process. In FIG. 9, 305 is a casting die, 321 is a region where a dew condensation process is performed, 331 is a region where a droplet evaporation process is performed, and 322 and 332 are a blower and a dryer, respectively.
8 and 9 show a portion from the coating to the droplet evaporation step in the entire conductive film manufacturing apparatus.

Furthermore, as a method of applying the organic solvent dispersion to the substrate, a slide coater 402 can be used as shown in FIG. 10 instead of the method using a casting die. In the form shown in FIG. 10, a slide coater 402 is installed facing the backup roller 404, and a decompression chamber 403 is installed in the slide coater 402. The slide coater is excellent in uniform coating property and productivity in the moving direction of the substrate, and can be applied without contacting the substrate 405, so that a uniform coating film can be formed without damaging the surface of the substrate 405. Can be formed. Furthermore, since the substrate is smoothed when it is wound around the backup roller 404, a uniform coating film can be formed.
Further, in place of the slide coater 402 in FIG. 10, a multilayer slide coater or an extrusion coater can be used.
In addition, in FIG. 10, the part of the process of apply | coating an organic-solvent dispersion body to a board | substrate among the whole electroconductive film manufacturing apparatuses is shown.

As another method, as shown in FIG. 11, a method of coating the organic solvent dispersion 502 on the substrate 504 using a wire bar coating machine 501 can also be used. In this method, the organic solvent dispersion 502 pulled up by the rotation of the wire bar 503 comes into contact with the substrate 504 to form a coating film.
Further, as shown in FIG. 12, a plate cylinder 603 having a recess on the surface and an impression cylinder 602 are installed facing each other, and the organic solvent dispersion 605 entering the recess 604 of the plate cylinder 603 by rotating the plate cylinder 603. It is also possible to use a coating method in which the coating is applied on the substrate 601 moving on the impression cylinder 602. In FIG. 12, reference numeral 606 denotes a doctor blade that scrapes off excess organic solvent dispersion 605.
11 and 12 also show a part of the step of applying the organic solvent dispersion to the substrate in the entire conductive film manufacturing apparatus.
The apparatus shown in FIGS. 7 to 13 and the part of the apparatus are all preferable embodiments of the conductive film manufacturing apparatus of the present invention, and the manufacturing apparatus capable of combining them in various ways is also the conductive film of the present invention. This is a preferred form of the manufacturing apparatus.

By the method for producing a conductive film of the present invention, a conductive film having excellent conductivity and light transmittance can be produced simply and inexpensively. In addition, since a high-temperature treatment process such as baking in the manufacturing process is not required, a general-purpose polymer substrate such as a PET film can be used as the substrate. And since the conductive film obtained in this way has the outstanding electroconductivity and light transmittance, it can be used suitably for displays, such as electronic paper.

FIG. 1-1 is a conceptual diagram of a cross-section of a coating film over time, showing an example of a process of evaporating an organic solvent while condensing a coated organic solvent dispersion on the coating film surface. FIGS. 1-2 (a) to (e) are conceptual diagrams illustrating a process of evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film. FIG. 2 is a schematic plan view of a mesh-like conductive film in which pores and mesh-like line portions are formed. FIG. 3 is a schematic cross-sectional view showing a method of using a Peltier device to cool a substrate and a coating film and to evaporate while blowing a humidified gas onto the coating film. FIG. 4 is a graph showing the relationship between the time during which a solvent solution containing an organic solvent acts and the surface resistivity in Examples 1 to 13. FIG. 5 is a graph showing the relationship between the time during which a solvent solution containing an organic solvent acts and the total light transmittance for Examples 1 to 13. FIG. 6 is a graph showing the relationship between the time during which a solvent solution containing an organic solvent acts and haze for Examples 1 to 13. FIG. 7 is a schematic view of a conductive film manufacturing facility 100 as an example of the conductive film manufacturing apparatus of the present invention. FIG. 8 shows, as an example of the conductive film manufacturing apparatus of the present invention, a portion from the coating of the organic solvent dispersion to the droplet evaporation step in the entire conductive film manufacturing apparatus. FIG. FIG. 9 shows, as an example of the conductive film manufacturing apparatus of the present invention, a part from the coating of the organic solvent dispersion to the droplet evaporation process in the entire conductive film manufacturing apparatus. FIG. FIG. 10 is a schematic view showing a part of a process for coating an organic solvent dispersion on a substrate in the entire conductive film manufacturing apparatus as an example of the conductive film manufacturing apparatus of the present invention. FIG. 11 is a schematic view showing a part of a process for applying an organic solvent dispersion on a substrate in the entire conductive film manufacturing apparatus as an example of the conductive film manufacturing apparatus of the present invention. FIG. 12 is a schematic view showing a part of a process of coating an organic solvent dispersion on a substrate in the entire conductive film manufacturing apparatus as an example of the conductive film manufacturing apparatus of the present invention. FIG. 13 is a schematic diagram showing a part of a process of allowing a solvent solution containing an organic solvent to act on a film having a pattern in the entire conductive film manufacturing apparatus as an example of the conductive film manufacturing apparatus of the present invention. is there.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

In the following examples and comparative examples, the physical properties of the conductive film were measured as follows.
<Surface resistivity>
The surface resistivity of the conductive film was measured by a four-terminal four-probe method using a resistivity meter Lorester-GP (manufactured by Mitsubishi Chemical Analytech, probe: ASP probe).
<Total light transmittance, haze>
The total light transmittance and haze of the conductive film were measured according to JIS K7361-1 using a haze meter NDH5000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

<Method for preparing conductive fine particle dispersion>
A 1 L beaker containing 148.1 g of octylamine (manufactured by Wako Pure Chemical Industries, Ltd.) is placed in a constant temperature bath at 40 ° C. Next, 18.6 g of silver acetate (manufactured by Wako Pure Chemical Industries, Ltd.) is added and thoroughly stirred and mixed for 20 minutes to prepare a uniform mixed solution. Subsequently, a reduction treatment was performed by gradually adding 20 g of a 20 wt% sodium borohydride aqueous solution.
After the reduction treatment, 200 g of acetone is added, and after standing for a while, a precipitate composed of silver and organic matter is separated and recovered by filtration. Toluene was added to the recovered material, redissolved, cooled to 10 ° C. or lower, and then filtered again to prepare a toluene dispersion with reduced impurities. Next, toluene was distilled off by an evaporator to prepare a conductive fine particle dispersion containing 20 wt% of silver fine particles. This solution was a solution containing 9 wt% octylamine and 71 wt% toluene in addition to the silver fine particles. When this solution was observed with FE-SEM, it was confirmed to be a nanoparticle dispersion having a particle size distribution with an average particle size of 4 nm and a coefficient of variation of 14%.

(Reference Example 1)
<Porous membrane preparation conditions>
Using the conductive fine particle dispersion solution, the weight concentration of silver was 0.93 mg / ml (corresponding to 0.120% by mass with respect to 100% by mass of the cyclohexane solution), NIKKOL Decaglyn 7-OV (polyglyceryl heptaoleate- (10, manufactured by Nikko Chemicals) 0.028 mg / ml (corresponding to 0.0036% by mass with respect to 100% by mass of the cyclohexane solution) was prepared. In an atmosphere of 23 ° C. and a relative humidity of 70%, 1.6 ml of the above solution was applied onto a 5 cm square PET film (Lumirror U34, double-sided easy-adhesion treated PET, manufactured by Toray Industries, Inc.) substrate, and humidified air (relative humidity of 70 %) Was sprayed at a flow rate of 1.6 m / min for 10 minutes to evaporate the organic solvent, and a dry film was formed.
<Drying conditions>
It was dried (air-dried) at room temperature and normal pressure.
<Baking conditions>
After drying, the film was heated at 10 ° C./min in an electric furnace at normal pressure and air atmosphere, and baked at 150 ° C. for 30 minutes. After firing, it was allowed to cool naturally and cooled to room temperature.
At this time, the surface resistivity of the conductive film was 1.7 × 10 ² Ω / □, the total light transmittance was 43.7%, and the haze was 34.5%. Further, the maximum film thickness, the aperture ratio, the line width, the average area of the hole portion, and the average maximum ferret diameter of the hole portion of the conductive film were obtained, and as shown in Table 1.

Example 1
Instead of the firing step, the membrane after drying was immersed in methanol, which is a solvent solution containing an organic solvent, for 3 minutes, and then dried at room temperature and normal pressure (air-dried). Thus, a conductive film was obtained.
The conductive film obtained at this time had a surface resistivity of 1.3 × 10 ⁶ Ω / □, a total light transmittance of 44.8%, and a haze of 34.0%. Further, the maximum film thickness, the aperture ratio, the line width, the average area of the hole portion, and the average maximum ferret diameter of the hole portion of the conductive film were obtained, and as shown in Table 1.

(Examples 2 to 11)
A conductive film was obtained in the same manner as in Example 1 except that the type of the solvent solution containing the organic solvent and the immersion time were changed as described in Table 1. As a result of evaluating the physical properties, they were as shown in Table 1.

(Example 12)
Instead of the firing step, the membrane after drying was immersed in methanol, which is a solvent solution containing an organic solvent, for 10 minutes, and then dried at room temperature and normal pressure (air-dried). A conductive film was obtained in the same manner as in Reference Example 1 except that it was immersed in hydrochloric acid for 1 minute, washed with water, and dried (air-dried) at room temperature and normal pressure. As a result of evaluating the physical properties of the obtained conductive film, it was as shown in Table 1.

(Example 13)
A conductive film was obtained in the same manner as in Example 12 except that acetone was used as a solvent solution containing an organic solvent. As a result of evaluating the physical properties of the obtained conductive film, it was as shown in Table 1.

From the results of Examples and Comparative Examples, the following was found.
A step of forming a film having a pattern by coating the organic solvent dispersion on the substrate, and then evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film; and a film having the pattern It is found that it is possible to form a conductive film that achieves a high level of both conductivity and light transmittance by producing a conductive film by applying a solvent solution containing an organic solvent to the substrate. (Examples 1 to 13).
Furthermore, a conductive film having the same degree of conductivity was obtained by performing a process in which a solvent solution containing an organic solvent was allowed to act on a film having a pattern without performing a baking process at a high temperature of 150 ° C. Furthermore, the obtained electroconductive film had a higher total light transmittance and a higher haze than the electroconductive film obtained by performing the firing step. In other words, from the viewpoint of light transmittance of the conductive film, it is found that the process of applying a solvent solution containing an organic solvent to the film having a pattern performed in the present invention has an advantage over the baking process. (For example, Reference Example 1 and Example 5).
Moreover, about the result of Examples 1-13, the graph which showed the relationship between the time for which the solvent solution containing an organic solvent is made to act, and surface resistivity, a total light transmittance, or a haze is each FIGS. 4-6. 4 to 6, it can be seen that the effect obtained is increased by extending the time for which the solvent solution containing the organic solvent is applied, regardless of the type of the solvent solution containing the organic solvent.
From these results, since the conductive film can be formed by the method for producing a conductive film of the present invention without firing at a high temperature, a general-purpose polymer substrate having a low heat resistance such as a PET film. It has also been demonstrated that a conductive film having excellent conductivity and light transmittance can be easily and inexpensively formed.
In the above examples, silver is used as the conductive material, octylamine is used as the fine particle dispersant, a specific nonionic surfactant is used as the surfactant, and a specific solvent solution containing an organic solvent is used. However, when a solvent solution containing an organic solvent is allowed to act, the fine particle dispersant, the surfactant, and the extra conductive fine particles isolated without being fused are washed away. The same applies to the case where the step of causing the solvent solution to contain is performed. Therefore, it can be said from the results of the above-described embodiments that the present invention can be applied in the entire technical scope of the present invention and in various forms disclosed in this specification, and can exhibit advantageous effects.

11, 21: substrate 12, 22: coating film (coated organic solvent dispersion)
13: Water droplet 14: Hole portion 15: Mesh-like line portion 20: Peltier element 101, 201, 401, 502, 605: Organic solvent dispersion 102 containing conductive fine particles, 202: Tank 103, 203: Stirrer 104, 204 : Pump 105, 205, 305: casting die 106, 206, 302, 405, 504, 601: substrate 107: temperature controller 108, 406: delivery rollers 109-111, 207, 208, 701-704: rotating roller 112 : Winding rollers 121, 221, 321: areas 122, 222, 322 for performing a dew condensation process: blowers 131, 231, 331: areas for performing a droplet evaporation process 132, 232, 332: dryer 141: a solvent containing an organic solvent Tanks 142 and 742 containing solutions: Solvent solutions 151 and 311 containing organic solvent: Coating film 152: Conductivity Film 301: Belt 402: slide coater 403: vacuum chamber 404: backup roller 501: a wire bar coater 503: wire bar 602: impression cylinder 603: plate cylinder 604: recess 606 of the plate cylinder 603: a doctor blade

Claims (5)

A method for producing a conductive film having a pattern by applying an organic solvent dispersion containing conductive fine particles to a substrate,
The manufacturing method comprises a step of forming a film having a pattern by applying an organic solvent dispersion to a substrate and then evaporating the organic solvent while allowing the applied organic solvent dispersion to condense on the coating film surface; and A method for producing a conductive film, comprising a step of allowing a solvent solution containing an organic solvent to act on the film having the pattern. The method for producing a conductive film according to claim 1, wherein the solvent solution containing the organic solvent is a polar solvent solution containing a polar solvent and / or a solubilizing agent. A conductive film produced by the method according to claim 1. The conductive film according to claim 3, wherein the conductive film is used for digital paper. An apparatus for producing a conductive film having a pattern by coating an organic solvent dispersion containing conductive fine particles on a substrate,
The manufacturing apparatus comprises: a means for forming a film having a pattern by coating an organic solvent dispersion on a substrate and then evaporating the organic solvent while the coated organic solvent dispersion is condensed on the surface of the coating film; And a means for causing a solvent solution containing an organic solvent to act on the film having a pattern.

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