JP7386713B2 - Method for producing organic solvent dispersion of highly conductive composite, method for producing conductive film - Google Patents

Description

The present invention relates to a method for producing an organic solvent dispersion of a highly conductive composite, a conductive film, and a method for producing the same.

As a paint for forming a conductive layer, a conductive polymer-containing liquid containing a conductive composite in which poly(3,4-ethylenedioxythiophene) is doped with polystyrene sulfonic acid may be used.
Patent Document 1 discloses that a conductive polymer aqueous dispersion is concentrated to 3.0 to 4.5% by mass and then mixed with a diol compound such as propylene glycol to produce a conductive polymer dispersion suitable for screen printing. A method for obtaining the information is disclosed.

JP 2019-104858 Publication

However, since about 50% by mass of the dispersion medium of the conductive polymer dispersion obtained by the method of Patent Document 1 is water, the wettability to the plastic substrate was not necessarily satisfactory.

The present invention is directed to the production of an organic solvent dispersion of a highly conductive composite that has a viscosity suitable for screen printing, has excellent wettability on plastic substrates, and is capable of forming a conductive layer with excellent conductivity. A method, a conductive film, and a method for manufacturing the same are provided.

[1] A mixed solution was obtained by mixing an aqueous dispersion of a conductive composite containing a π-conjugated conductive polymer and a polyanion with an organic solvent, and a highly conductive composite was precipitated in the mixed solution. After that, adding an epoxy compound to the mixed solution, separating the highly conductive composite to which the epoxy compound has been added, and adding a diol compound to the obtained highly conductive composite. A method for producing an organic solvent dispersion of a conductive composite.
[2] The organic solvent dispersion of the highly conductive composite according to [1], wherein the content of the organic solvent contained in the mixed solution is 50% by mass or more based on the total mass of the mixed solution. manufacturing method.
[3] The method for producing an organic solvent dispersion of a highly conductive composite according to [1] or [2], wherein the organic solvent contains at least one of a ketone solvent and an alcohol solvent.
[4] The method for producing an organic solvent dispersion of a highly conductive composite according to [3], wherein the organic solvent contains a ketone solvent, and the ketone solvent contains methyl ethyl ketone.
[5] The method for producing an organic solvent dispersion of a highly conductive composite according to [3], wherein the organic solvent contains an alcohol solvent, and the alcohol solvent contains methanol.
[6] The method for producing an organic solvent dispersion of a highly conductive composite according to [1] or [2], wherein the organic solvent contains methyl ethyl ketone and methanol.
[7] The highly conductive composite according to any one of [1] to [6], wherein the mixed solution is heated to 40° C. or higher when depositing the highly conductive composite in the mixed solution. A method for producing an organic solvent dispersion.
[8] When depositing the highly conductive composite in the mixed liquid, the content of at least one of an acid and a base other than the polyanion in the mixed liquid is 0 with respect to the total mass of the mixed liquid. .1% by mass or less, a method for producing an organic solvent dispersion of the highly conductive composite according to any one of [1] to [7].
[9] The method for producing an organic solvent dispersion of a highly conductive composite according to any one of [1] to [8], wherein the method for separating the highly conductive composite is filtration.
[10] The method for producing an organic solvent dispersion of a highly conductive composite according to any one of [1] to [9], wherein the diol compound contains propylene glycol, ethylene glycol, or diethylene glycol.
[11] Organic solvent dispersion of the highly conductive composite according to any one of [1] to [10], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene). Method of manufacturing liquid.
[12] The method for producing an organic solvent dispersion of a highly conductive composite according to any one of [1] to [11], wherein the polyanion is polystyrene sulfonic acid.
[13] A method for producing an organic solvent dispersion of a highly conductive composite according to any one of [1] to [12], which further includes mixing a binder component.
[14] The method for producing an organic solvent dispersion of a highly conductive composite according to [13], wherein the binder component is a water-dispersible resin.
[15] The organic solvent dispersion of the highly conductive composite obtained by the manufacturing method according to any one of [1] to [14] is applied to at least one surface of the film base material, and the composite is formed. A method for producing a conductive film, the method comprising drying a coated film.
[16] The method for producing a conductive film according to [15], wherein the method for applying the organic solvent dispersion of the highly conductive composite is screen printing.
[17] A conductive layer consisting of a cured layer of an organic solvent dispersion of a highly conductive composite obtained by the production method according to any one of [1] to [14] on at least one surface of the film base material. A conductive film with

According to the method for producing an organic solvent dispersion of a highly conductive composite of the present invention, a conductive layer having a viscosity suitable for screen printing, excellent wettability to a plastic substrate, and excellent conductivity can be formed. It is possible to manufacture paints that can.
According to the method for producing a conductive film of the present invention, a conductive layer having excellent conductivity and good light transmittance can be formed on a plastic substrate. In addition, screen printing can be performed in which the boundary between the printed area that becomes the conductive layer and the non-printed area is clear and does not bleed, and printing unevenness (fading) is reduced.
The conductive film of the present invention includes a conductive layer having excellent conductivity and good light transmittance. When the conductive layer is formed by screen printing, the boundary between the conductive layer consisting of the printed area and the insulating part consisting of the non-printing area is clearer than before and there is no bleeding, and printing unevenness (fading) is reduced. has been done.

<<Method for producing organic solvent dispersion of highly conductive composite>>
A mixed solution is obtained by mixing an aqueous dispersion of a conductive composite containing a π-conjugated conductive polymer and a polyanion with an organic solvent, and a highly conductive composite is precipitated in the mixed solution. A highly conductive composite comprising adding an epoxy compound to a mixed solution, separating the highly conductive composite to which the epoxy compound has been added, and adding a diol compound to the obtained highly conductive composite. This is a method for producing an organic solvent dispersion of a liquid.

[Aqueous dispersion of conductive composite]
The aqueous dispersion of a conductive composite used in this embodiment (hereinafter sometimes referred to as "conductive polymer aqueous dispersion") is a conductive composite containing a π-conjugated conductive polymer and a polyanion, and water. Contains. This aqueous dispersion may contain an organic solvent as long as the conductive composite in the liquid is in a dispersed state.

The polyanion is doped into a π-conjugated conductive polymer to form a conductive composite having conductivity. In the polyanion, only some of the anion groups are doped into the π-conjugated conductive polymer, and there are surplus anion groups that do not participate in doping. Since the excess anion group is a hydrophilic group, the conductive composite has water dispersibility.

In the conductive polymer aqueous dispersion used in this embodiment, the conductive composite is in a dispersed state. The dispersion state and the precipitation state can be easily distinguished visually. The transparency of the dispersion liquid in the dispersed state is high, and no suspended solid matter is found in the dispersion liquid. On the other hand, the transparency of the liquid in the precipitated state is low, and suspended solids are observed in the liquid. Generally, a conductive composite in a dispersed state does not easily precipitate; for example, even if it is allowed to stand still for 12 hours, precipitation is unlikely to occur. On the other hand, suspended matter in a liquid in a precipitated state tends to settle, and tends to cause precipitation, for example, by allowing it to stand for about 12 hours.

When the conductive polymer aqueous dispersion used in this embodiment is passed through a filter having a retained particle size of 7 μm, the conductive composite in a dispersed state passes through the filter together with the dispersion medium. On the other hand, the conductive composite in a precipitated state can be captured by the filter.
Here, the retained particle size of the filter paper is a measure of the coarseness of the filter paper, and is determined by the leaked particle size when barium sulfate or the like is naturally filtered as specified in JIS P 3801 [Filter paper (for chemical analysis)].

(π-conjugated conductive polymer)
The π-conjugated conductive polymer may be any organic polymer whose main chain is composed of a π-conjugated system, such as polypyrrole-based conductive polymers, polythiophene-based conductive polymers, and polyacetylene-based conductive polymers. Examples include polyphenylene conductive polymers, polyphenylene vinylene conductive polymers, polyaniline conductive polymers, polyacene conductive polymers, polythiophene vinylene conductive polymers, and copolymers thereof. From the viewpoint of stability in air, polypyrrole-based conductive polymers, polythiophenes, and polyaniline-based conductive polymers are preferred, and from the viewpoint of transparency, polythiophene-based conductive polymers are more preferred.

Polythiophene-based conductive polymers include polythiophene, poly(3-methylthiophene), poly(3-ethylthiophene), poly(3-propylthiophene), poly(3-butylthiophene), poly(3-hexylthiophene). , poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly(3-octadecylthiophene), poly(3-bromothiophene), poly (3-chlorothiophene), poly(3-iodothiophene), poly(3-cyanothiophene), poly(3-phenylthiophene), poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene) , poly(3-hydroxythiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptyloxythiophene) , poly(3-octyloxythiophene), poly(3-decyloxythiophene), poly(3-dodecyloxythiophene), poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3-decyloxythiophene) ,4-dimethoxythiophene), poly(3,4-diethoxythiophene), poly(3,4-dipropoxythiophene), poly(3,4-dibutoxythiophene), poly(3,4-dihexyloxythiophene) , poly(3,4-diheptyloxythiophene), poly(3,4-dioctyloxythiophene), poly(3,4-didecyloxythiophene), poly(3,4-didodecyloxythiophene), poly( 3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), poly(3,4-butylenedioxythiophene), poly(3-methyl-4-methoxythiophene), poly(3- methyl-4-ethoxythiophene), poly(3-carboxythiophene), poly(3-methyl-4-carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), poly(3-methyl-4-carboxythiophene) butylthiophene).
Examples of polypyrrole-based conductive polymers include polypyrrole, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-ethylpyrrole), poly(3-n-propylpyrrole), and poly(3-butylpyrrole). pyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3-dodecylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-dibutylpyrrole) -carboxypyrrole), poly(3-methyl-4-carboxypyrrole), poly(3-methyl-4-carboxyethylpyrrole), poly(3-methyl-4-carboxybutylpyrrole), poly(3-hydroxypyrrole) , poly(3-methoxypyrrole), poly(3-ethoxypyrrole), poly(3-butoxypyrrole), poly(3-hexyloxypyrrole), and poly(3-methyl-4-hexyloxypyrrole).
Examples of polyaniline-based conductive polymers include polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-aniline sulfonic acid), and poly(3-aniline sulfonic acid).
Among these π-conjugated conductive polymers, poly(3,4-ethylenedioxythiophene) is particularly preferred in terms of conductivity, transparency, and heat resistance.
The number of types of π-conjugated conductive polymers contained in the conductive composite may be one or two or more types.

(Polyanion)
A polyanion is a polymer having two or more monomer units having anionic groups in its molecule. The anion group of this polyanion functions as a dopant for the π-conjugated conductive polymer to improve the conductivity of the π-conjugated conductive polymer.
The anion group of the polyanion is preferably a sulfo group or a carboxy group.
Specific examples of such polyanions include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallylsulfonic acid, polyacrylic ester having a sulfo group, polymethacrylic ester having a sulfo group (for example, poly(4-sulfobutyl methacrylate) , polysulfoethyl methacrylate, polymethacryloyloxybenzenesulfonic acid), poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprene sulfonic acid, and other polymers with sulfo groups, polyvinylcarboxylic acid, polystyrenecarboxylic acid, Polymers having carboxyl groups such as polyarylcarboxylic acid, polyacrylic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropanecarboxylic acid), and polyisoprenecarboxylic acid are mentioned. may be a homopolymer obtained by polymerizing two or more types of monomers, or a copolymer obtained by polymerizing two or more types of monomers.
Among these polyanions, polymers having sulfo groups are preferred, and polystyrene sulfonic acid is more preferred, since it can further increase the conductivity.
The polyanions may be used alone or in combination of two or more.
The mass average molecular weight of the polyanion is preferably 20,000 or more and 1,000,000 or less, more preferably 100,000 or more and 500,000 or less. The mass average molecular weight is a mass-based average molecular weight measured using gel permeation chromatography and calculated in terms of polystyrene.

The content ratio of the polyanion in the conductive composite is preferably in the range of 1 part by mass or more and 1000 parts by mass or less, and 10 parts by mass or more and 700 parts by mass or less, based on 100 parts by mass of the π-conjugated conductive polymer. It is more preferable that it is, and it is even more preferable that it is in the range of 100 parts by mass or more and 500 parts by mass or less. If the content ratio of the polyanion is equal to or higher than the lower limit value, the doping effect on the π-conjugated conductive polymer tends to become stronger, and the conductivity becomes higher. On the other hand, if the content of the polyanion is below the upper limit value, the π-conjugated conductive polymer can be sufficiently contained, so that sufficient conductivity can be ensured.

<Method for producing conductive polymer aqueous dispersion>
A conductive polymer aqueous dispersion in which a conductive composite containing a π-conjugated conductive polymer and a polyanion is dispersed in an aqueous dispersion medium, for example, forms a π-conjugated conductive polymer in an aqueous solution of a polyanion. It can be obtained by chemical oxidative polymerization of monomers. Alternatively, a commercially available conductive polymer aqueous dispersion may be used.

The chemical oxidative polymerization can be performed using a known catalyst and oxidizing agent. Examples of the catalyst include transition metal compounds such as ferric chloride, ferric sulfate, ferric nitrate, and cupric chloride. Examples of the oxidizing agent include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate. The oxidizing agent can return the reduced catalyst to its original oxidized state.

The content of the conductive composite contained in the aqueous conductive polymer dispersion of this embodiment is preferably, for example, 0.1% by mass or more and 20% by mass or less, and 0.1% by mass or more and 20% by mass or less, based on the total mass of the aqueous dispersion. It is more preferably 5% by mass or more and 10% by mass or less, and even more preferably 1.0% by mass or more and 5.0% by mass or less. If it is at least the lower limit of the above range, the highly conductive composite will be easily deposited after addition of the organic solvent. If it is below the upper limit of the above range, the dispersibility of the conductive composite in the aqueous conductive polymer dispersion will increase, preventing unintentional aggregation during storage of the aqueous conductive polymer dispersion, and preventing the addition of organic solvents. The quality of the highly conductive composite that is deposited later can be made uniform.

The conductive polymer aqueous dispersion used in this embodiment may contain an organic solvent to the extent that the conductive composite is in a dispersed state. The content of the organic solvent is preferably as small as possible, and it is more preferable that it is substantially not contained. For example, it is preferably 10% by mass or less, more preferably 5% by mass or less, and 1% by mass based on the total mass of the aqueous dispersion. The following are more preferred.
The organic solvent that may be contained in the aqueous conductive polymer dispersion used in this embodiment is preferably one that is highly miscible with water, and includes, for example, the alcohol solvents described below.
In this specification, the term "conductive polymer aqueous dispersion" is a term that clearly indicates that it contains water as a dispersion medium and does not substantially contain an organic solvent.

[Preparation of mixed solution]
Methods of mixing a conductive polymer aqueous dispersion and an organic solvent to obtain a mixed solution include, for example, adding an organic solvent to a conductive polymer aqueous dispersion, and adding a conductive polymer aqueous dispersion to an organic solvent. Examples include a method of adding a liquid. A preferred embodiment includes a method of gradually adding an organic solvent while stirring the conductive polymer aqueous dispersion. With this addition method, it is possible to prevent the organic solvent concentration in the aqueous conductive polymer dispersion from rising locally and to gently precipitate the highly conductive composite. Rapid increases in organic solvent concentration may result in heterogeneous agglomerations of highly conductive composites.

The content of the organic solvent contained in the mixed solution is preferably 50% by mass or more and less than 100% by mass, more preferably 55% by mass or more and 90% by mass or less, and 60% by mass, based on the total mass of the mixed solution. It is more preferably 85% by mass or less, and particularly preferably 60% by mass or more and 80% by mass or less. Here, the content of the organic solvent is the amount including the organic solvent contained in the aqueous conductive polymer dispersion before mixing.
When the amount is at least the lower limit of the above range, precipitation of the highly conductive composite becomes easier, and the yield of the highly conductive composite improves.
When it is below the upper limit of the above range, the amount of the conductive polymer aqueous dispersion contained in the liquid mixture can be relatively increased, so the amount of the highly conductive composite to be fractionated can be increased.

After mixing a conductive polymer aqueous dispersion and an organic solvent, the appearance of the resulting mixture after standing may be that water and organic solvent are completely compatible with each other, or that they are separated from each other. However, from the viewpoint of facilitating the precipitation of the highly conductive composite, it is preferable that they are sufficiently compatible.

(Organic solvent)
The organic solvent constituting the liquid mixture of this embodiment is preferably a water-soluble organic solvent. Here, the water-soluble organic solvent is an organic solvent that dissolves in an amount of 1 g or more per 100 g of water at a temperature of 20°C.
Examples of the water-soluble organic solvent include alcohol solvents, ketone solvents, and ester solvents.
Examples of alcoholic solvents include methanol, ethanol, isopropanol, n-butanol, t-butanol, and allyl alcohol. Here, the alcohol solvent is preferably an alcohol solvent other than the diol compound described below.
Examples of the ketone solvent include methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diethyl ketone, diisopropyl ketone, acetone, diacetone alcohol, and the like.
Examples of the ester solvent include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and the like.
One type of organic solvent may be used alone, or two or more types may be used in combination.

The organic solvent constituting the liquid mixture of this embodiment preferably contains at least one of a ketone solvent and an alcohol solvent.
It is preferable that methyl ethyl ketone is included as the ketone solvent.
As the alcohol solvent, methanol or isopropanol is preferred.
When the above-mentioned suitable organic solvent is included, the highly conductive composite can be more easily precipitated in the mixed solution, and the yield can be further improved.

In the liquid mixture of this embodiment, methyl ethyl ketone is preferably included in combination with methanol or isopropanol, and more preferably in combination with methanol. In this case, the content of methanol or isopropanol per 100 parts by mass of methyl ethyl ketone is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 3 parts by mass or more and 50 parts by mass or less, and even more preferably 6 parts by mass or more and 20 parts by mass or less. .
When the above-mentioned suitable combination of organic solvents is included, the highly conductive composite can be more easily precipitated in the mixed solution, and the yield can be further improved.
When the organic solvent is contained in the above-mentioned suitable range, the highly conductive composite can be more easily precipitated in the liquid mixture, and the yield can be further improved.

In the liquid mixture of this embodiment, isopropanol is preferably included in combination with methyl acetate or ethyl acetate. In this case, the content of methyl acetate or ethyl acetate per 100 parts by mass of isopropanol is preferably 10 parts by mass or more and 300 parts by mass or less, more preferably 30 parts by mass or more and 200 parts by mass or less, and 60 parts by mass or more and 100 parts by mass or less. More preferred.
When the above-mentioned suitable combination of organic solvents is included, the highly conductive composite can be more easily precipitated in the mixed solution, and the yield can be further improved.
When the organic solvent is contained in the above-mentioned suitable range, the highly conductive composite can be more easily precipitated in the liquid mixture, and the yield can be further improved.

In the liquid mixture of this embodiment, it is preferable that methyl ethyl ketone, isopropanol, and methyl acetate or ethyl acetate are contained in combination. In this case, the content of methyl acetate or ethyl acetate per 100 parts by mass of isopropanol is preferably 10 parts by mass or more and 300 parts by mass or less, more preferably 30 parts by mass or more and 200 parts by mass or less, and 60 parts by mass or more and 100 parts by mass or less. More preferred. The content of methyl ethyl ketone per 100 parts by mass of isopropanol is preferably 100 parts by mass or more and 3000 parts by mass or less, more preferably 200 parts by mass or more and 2000 parts by mass or less, and even more preferably 500 parts by mass or more and 1000 parts by mass or less.
When the above-mentioned suitable combination of organic solvents is included, the highly conductive composite can be more easily precipitated in the mixed solution, and the yield can be further improved.
When the organic solvent is contained in the above-mentioned suitable range, the highly conductive composite can be more easily precipitated in the liquid mixture, and the yield can be further improved.

When depositing a highly conductive composite in the mixed liquid of this embodiment, the content of at least one of an acid and a base other than the polyanion in the mixed liquid is 0.1 with respect to the total mass of the mixed liquid. It is preferably at most 0.01% by mass, more preferably at most 0.01% by mass, and most preferably substantially not contained.
Examples of the acid include inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids such as paratoluenesulfonic acid and naphthalenesulfonic acid.
Examples of the base include inorganic bases such as sodium hydroxide and sodium carbonate, and organic bases such as trioctylamine and octylamine.
The above acids and bases may be a cause of inhibiting precipitation of the highly conductive composite in the mixed liquid of this embodiment. Further, when a strong acidic substance or a strong basic substance is contained, the polyanion may be dedoped and the conductivity may be reduced.

[Deposition of highly conductive composite]
The method for depositing the highly conductive composite in the prepared mixed solution is not particularly limited, and the highly conductive composite can be deposited simply by allowing the mixed solution to stand still. Further, it is not necessary to allow the mixture to stand completely still, and the precipitation may be performed while stirring gently.

When depositing the highly conductive composite in the mixed liquid, it is preferable to heat the mixed liquid. The heating temperature is preferably 40°C or higher, more preferably 50°C or higher and 100°C or lower, and even more preferably 60°C or higher and 80°C or lower. The heating time at the above-mentioned suitable heating temperature can be, for example, 1 hour or more and 10 hours or less.
When the mixed liquid is heated, the highly conductive composite can be easily precipitated in the mixed liquid, and the yield of the highly conductive composite can be improved.
When separating the precipitated highly conductive composite from the mixed liquid, it is preferable to return the temperature to room temperature (20 to 25°C) before separating.

[Addition of epoxy compound]
By adding an epoxy compound to the mixed liquid in which the highly conductive composite is precipitated, the epoxy compound is added to some of the anion groups of the polyanions constituting the highly conductive composite, thereby forming the highly conductive composite. Can be made hydrophobic. The highly conductive composite before being hydrophobized has high dispersibility in water, and the highly conductive composite that has been hydrophobized has high dispersibility in organic solvents.
The structure of the substituent in which the epoxy compound is added to the surplus anion group that does not participate in the doping of the polyanion is a substituent represented by the following chemical formula (A1) or the following chemical formula (A2) formed by ring-opening reaction of the epoxy group. It is considered to be group (A).

［式（Ａ１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、及びＲ^１４はそれぞれ独立に、水素原子、又は任意の置換基である。］

[In formula (A1), R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ are each independently a hydrogen atom or an arbitrary substituent. ]

［式（Ａ２）中、ｍは２以上の整数であり、複数のＲ^１５、複数のＲ^１６、複数のＲ^１７、及び複数のＲ^１８はそれぞれ独立に、水素原子、又は任意の置換基であり、複数のＲ^１５は同一でも異なっていてもよく、複数のＲ^１６は同一でも異なっていてもよく、複数のＲ^１７は同一でも異なっていてもよく、複数のＲ^１８は同一でも異なっていてもよい。］

[In formula (A2), m is an integer of 2 or more, and R ¹⁵ s, R ¹⁶ s, R ¹⁷ s, and R ^18s are each independently a hydrogen atom or an arbitrary substituent. , multiple R ^15s may be the same or different, multiple R ^16s may be the same or different, multiple R ^17s may be the same or different, and multiple R ^18s may be the same or different. You can. ]

In formulas (A1) and (A2), the leftmost bond represents that the substituent (A) is substituted with a proton of an anion group. Examples of the anionic group having a substituted proton include anionic groups having an active proton bonded to an oxygen atom such as "--SO ₃ H".

In formula (A1), optional substituents for R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ include an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent; Examples include aromatic hydrocarbon groups having 6 to 20 carbon atoms that may be present. R ¹¹ and R ¹³ may be bonded to form a ring which may have a substituent. For example, R ¹¹ and R ¹³ are the above-mentioned hydrocarbon groups, and a divalent hydrocarbon group obtained by removing any one hydrogen atom of the monovalent hydrocarbon group of R ¹¹ and a monovalent hydrocarbon group of R ¹³ An example is a case where a divalent hydrocarbon group from which any one hydrogen atom has been removed is bonded to the carbon atoms from which the hydrogen atom has been removed to form a ring.

In this specification, "may have a substituent" refers to the case where a hydrogen atom (-H) is substituted with a monovalent group, and the case where a methylene group (-CH ₂ -) is substituted with a divalent group. This includes both replacement and replacement cases.
Monovalent groups as substituents include alkyl groups having 1 to 4 carbon atoms, alkenyl groups having 2 to 4 carbon atoms, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.), trialkoxysilyl groups. (trimethoxysilyl group, etc.), and the like.
Examples of the divalent group as a substituent include an oxygen atom (-O-), -C(=O)-, -C(=O)-O-, and the like. However, this excludes the case where two oxygen atoms are adjacent to each other.

In formula (A2), optional substituents for R ¹⁵ , R ¹⁶ , R ¹⁷ , and R ¹⁸ include aliphatic hydrocarbon groups having 1 to 20 carbon atoms which may have substituents; Examples include aromatic hydrocarbon groups having 6 to 20 carbon atoms that may be present. R ¹⁵ and R ¹⁷ may be bonded to form a ring which may have a substituent. Examples of forming a ring are the same as above.

In formula (A2), m is an integer of 2 or more, preferably 2 to 100, more preferably 2 to 50, and even more preferably 2 to 25. When m is at least the above lower limit, the hydrophobicity of the highly conductive composite becomes sufficiently high. When m is less than or equal to the upper limit value, it is possible to prevent the hydrophobicity from becoming too high or the conductivity from decreasing.

The molecular weight of the epoxy compound added to the mixed liquid is, for example, preferably 50 or more and 1000 or less, more preferably 60 or more and 300 or less, and even more preferably 70 or more and 200 or less.
Within the above range, the above-mentioned suitable substituent (A) can be formed.

The epoxy compound is a compound having one or more epoxy groups in one molecule.
One type of epoxy compound may be used alone, or two or more types may be used in combination.

Examples of monofunctional epoxy compounds having one epoxy group in one molecule include ethylene oxide, propylene oxide, 2,3-butylene oxide, isobutylene oxide, 1,2-butylene oxide, 1,2-epoxyhexane, 1 , 2-epoxyheptane, 1,2-epoxypentane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,3-butadiene monoxide, 1,2-epoxytetradecane, glycidyl methyl ether, 1,2- Epoxyoctadecane, 1,2-epoxyhexadecane, ethyl glycidyl ether, glycidyl isopropyl ether, tert-butyl glycidyl ether, 1,2-epoxyeicosane, 2-(chloromethyl)-1,2-epoxypropane, glycidol, epichlorohydrin, Epibromohydrin, butyl glycidyl ether, 1,2-epoxyhexane, 1,2-epoxy-9-decane, 2-(chloromethyl)-1,2-epoxybutane, 2-ethylhexyl glycidyl ether, 1,2- Epoxy-1H,1H,2H,2H,3H,3H-trifluorobutane, allyl glycidyl ether, tetracyanoethylene oxide, glycidyl butyrate, 1,2-epoxycyclooctane, glycidyl methacrylate, 1,2-epoxycyclododecane, 1-Methyl-1,2-epoxycyclohexane, 1,2-epoxycyclopentadecane, 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,2-epoxy-1H,1H,2H,2H,3H, 3H-heptadecafluorobutane, 3,4-epoxytetrahydrofuran, glycidyl stearate, 3-glycidyloxypropyltrimethoxysilane, epoxysuccinic acid, glycidylphenyl ether, isophorone oxide, α-pinene oxide, 2,3-epoxynorbornene, Benzylglycidyl ether, diethoxy(3-glycidyloxypropyl)methylsilane, 3-[2-(perfluorohexyl)ethoxy]-1,2-epoxypropane, 1,1,1,3,5,5,5-heptamethyl- 3-(3-glycidyloxypropyl)trisiloxane, 9,10-epoxy-1,5-cyclododecadiene, 4-tert-butylglycidylbenzoate, 2,2-bis(4-glycidyloxyphenyl)propane, 2 -tert-butyl-2-[2-(4-chlorophenyl)]ethyloxirane, styrene oxide, glycidyl trityl ether, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-phenylpropylene oxide, cholesterol-5α , 6α-epoxide, stilbene oxide, glycidyl p-toluenesulfonate, ethyl 3-methyl-3-phenylglycidate, N-propyl-N-(2,3-epoxypropyl)perfluoro-n-octylsulfonamide, ( 2S,3S)-1,2-epoxy-3-(tert-butoxycarbonylamino)-4-phenylbutane, (R)-glycidyl 3-nitrobenzenesulfonate, glycidyl 3-nitrobenzenesulfonate, parthenolide, N-glycidyl Phthalimide, endrin, deirdrin, 4-glycidyloxycarbazole, 7,7-dimethyloctanoic acid [oxiranylmethyl], 1,2-epoxy-4-vinylcyclohexane, higher alcohol glycidyl ether with 10 to 16 carbon atoms, diallyl mono Examples include glycidyl isocyanurate.

Examples of polyfunctional epoxy compounds having two or more epoxy groups in one molecule include 1,6-hexanediol diglycidyl ether, 1,7-octadiene diepoxide, neopentyl glycol diglycidyl ether, and 4-butanediol. Diglycidyl ether, 1,2:3,4-diepoxybutane, diglycidyl 1,2-cyclohexanedicarboxylate, triglycidyl isocyanurate (also known as triglycidyl isocyanurate), neopentyl glycol diglycidyl ether, 1,2:3 , 4-diepoxybutane, polyethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexane diol di Glycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolpropane polyglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hexahydrophthalic acid diglycidyl ester, glycerin polyglycidyl ether, diglycerin polyglycidyl ether, poly Examples include glycerin polyglycidyl ether, sorbitol polyglycidyl ether, and ethylene oxide lauryl alcohol glycidyl ether.

Among the epoxy compounds listed above, it is easy to achieve a viscosity suitable for screen printing, it is easy to reduce printing bleeding and printing unevenness (fading) of the screen-printed coating film (conductive layer), and it is easy to improve the conductivity and light of the conductive layer to be formed. Glycidol, 1,2-butylene oxide, 1,2-epoxy-4-vinylcyclohexane, or triglycidyl isocyanurate is preferred, and glycidol or triglycidyl isocyanurate is more preferred, since the permeability tends to increase.

The amount of the epoxy compound added to the mixed solution is 1 part by mass or more and 10,000 parts by mass or less, based on 100 parts by mass of the π-conjugated conductive polymer and polyanion contained in the mixed solution. It is preferably 100 parts by mass or more and 5000 parts by mass or less, even more preferably 200 parts by mass or more and 1000 parts by mass or less, and particularly preferably 300 parts by mass or more and 800 parts by mass or less. If the addition ratio of the epoxy compound is at least the above-mentioned lower limit, the dispersibility of the highly conductive composite in organic solvents will be higher, and if it is below the above-mentioned upper limit, the conductivity of the highly conductive composite will be prevented from decreasing. be able to.

[Preparation of highly conductive composite]
The method for separating (recovering) the highly conductive composite to which the epoxy compound is added in the mixed liquid is not particularly limited, and includes, for example, filtration, decantation, centrifugation, vacuum drying, freeze drying, and spray drying. etc.
Among these, filtration or decantation is preferred because it is easy to separate the highly conductive composite from components other than the highly conductive composite contained in the liquid mixture. Here, filtration is an operation in which a highly conductive composite is captured in a filter through which a liquid mixture is passed. Moreover, decantation is an operation of precipitating the precipitated highly conductive composite and removing the supernatant liquid.
When fractionating by filtration, it is necessary to deal with clogging of the filter. Furthermore, since the solid matter of the highly conductive composite is compressed on the filter by the filtration pressure, the highly conductive composite separated by filtration tends to be in a harder state than when separated by decantation. Since the highly conductive composite obtained by decantation is obtained in a relatively soft powder state, it can be easily dispersed in a dispersion medium later.
On the other hand, when fractionating by decantation, it is necessary to wait until the highly conductive complex precipitates in the mixed solution. From the viewpoint of increasing the production rate of the highly conductive composite, it is preferable to separate it by filtration.

The separated highly conductive composite is preferably washed using an organic solvent that does not easily dissolve the highly conductive composite. Specifically, for example, an organic solvent may be poured onto a filter that has captured the highly conductive composite, or an organic solvent may be added to the highly conductive composite remaining at the bottom of the container after decantation, and the mixture may be stirred. After that, it may be fractionated again by decantation or the like.
By drying and removing the organic solvent and the like adhering to the separated highly conductive composite, a dried body of the highly conductive composite can be obtained.

[Addition of diol compound]
The diol compound added to the highly conductive composite to which an epoxy compound has been added (hereinafter, if it is clear from the context that an epoxy compound has been added, it may be simply referred to as a highly conductive composite) is a hydroxyl compound. It is an organic compound with two groups. By including a diol compound as a dispersion medium in the organic solvent dispersion of the highly conductive composite, the printability of the organic solvent dispersion of the highly conductive composite can be improved.
The diol compound is preferably a compound in which one of the hydrogen atoms at both ends of a linear aliphatic hydrocarbon is substituted with a hydroxy group. Further, the diol compound is preferably liquid at 25° C. since the highly conductive composite can be easily dispersed. Furthermore, the diol compound preferably has a boiling point of 250° C. or lower at standard pressure (1013 hPa) because it is easy to dry and can prevent contamination of the drying oven. Further, the boiling point of the diol compound at standard pressure is preferably 100° C. or higher in terms of suppressing volatilization of the diol compound.
Among diol compounds, ethylene glycol, diethylene glycol, propylene glycol, and butanediol (1,4-butanediol, 1,3-butanediol) are preferred in terms of further improving the printability of organic solvent dispersions of highly conductive composites. , 2,3-butanediol, and 1,2-butanediol) is preferred. Note that ethylene glycol, diethylene glycol, propylene glycol, and butanediol are diol compounds that are liquid at 25°C and have a boiling point of 250°C or less at standard pressure.

The amount of the diol compound added to the separated highly conductive composite is such that the content of the diol compound is 10% by mass or more when the mass of the organic solvent dispersion obtained by adding the diol compound is 100% by mass. The content is preferably .9% by mass or less, more preferably 50% by mass or more and 99% by mass or less, and even more preferably 80% by mass or more and 98% by mass or less. When the content ratio of the diol compound is within the above range, the printability of the organic solvent dispersion of the highly conductive composite becomes higher, and the dispersibility of the highly conductive composite can be further improved.

In the organic solvent dispersion of the highly conductive composite obtained by the manufacturing method of this embodiment, the solid content concentration (nonvolatile component concentration) of the highly conductive composite is 0.1 with respect to the total mass of the organic solvent dispersion. It is preferably at least 10% by mass, more preferably at least 0.5% by mass and at most 8% by mass, and even more preferably at least 1% by mass and at most 6% by mass.
When it is at least the lower limit of the above range, the conductivity of the conductive layer formed from the organic solvent dispersion can be further improved.
When it is below the upper limit of the above range, the dispersibility of the highly conductive composite in the organic solvent dispersion can be improved.

In the organic solvent dispersion of the highly conductive composite obtained by the production method of this embodiment, the water content is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the organic solvent dispersion. It is preferably 1% by mass or less, more preferably 1% by mass or less, particularly preferably substantially free of water, and may be 0% by mass. When the water content is within the above range, the dispersibility of the highly conductive composite in the organic solvent dispersion of the highly conductive composite can be further improved, and the wettability of the highly conductive composite to the plastic substrate can be further improved.

(Distributed processing)
A dispersion treatment may be performed after mixing the highly conductive composite and the diol compound. If dispersion treatment is performed, the dispersibility of the highly conductive composite in the organic solvent dispersion will be improved, so the conductivity and transparency of the conductive layer obtained by coating or printing the organic solvent dispersion can be further improved. .
The dispersion treatment is a treatment in which shear force is applied to a liquid mixture containing a highly conductive composite and a diol compound to disperse each component.
Examples of the dispersion machine used for the dispersion treatment include a homogenizer, a high-pressure homogenizer, and a bead mill. Among the dispersing machines, a high-pressure homogenizer is preferred because it can easily improve the dispersibility of each component.

(Addition of other ingredients)
The organic solvent dispersion of the highly conductive composite may contain a binder resin, a water-soluble organic solvent, a highly conductive agent, other additives, and the like. These components may be added to the organic solvent dispersion, or may be added to the diol compound before being mixed with the highly conductive composite.

The binder resin is a resin other than a π-conjugated conductive polymer and a polyanion, and is a resin that binds a highly conductive composite in the conductive layer and increases the strength of the conductive layer.
Specific examples of the binder resin include polyester, acrylic resin, polyurethane, polyimide, melamine resin, and the like.
It is preferable to use a water-dispersible resin as the binder resin because the dispersibility of the highly conductive composite in the organic solvent dispersion becomes high and the strength of the coating film is also improved.
Examples of the water-dispersible resin include water-dispersible polyester, water-dispersible acrylic resin, water-dispersible polyurethane, water-dispersible polyimide, and water-dispersible melamine resin. Among these water-dispersible resins, water-dispersible polyesters are preferred. If the binder resin is water-dispersible polyester, the conductivity of the conductive layer formed by coating or printing an organic solvent dispersion of the highly conductive composite can be increased, and the film strength can be increased. In addition, if the water-dispersible resin is water-dispersible polyester, when a polyethylene terephthalate film is used as a base material for applying or printing the organic solvent dispersion of the highly conductive composite, the adhesion of the conductive layer to the base material can be increased.
The water-dispersible resin preferably has an acid group such as a carboxyl group or a sulfo group, or a salt thereof, from the viewpoint of improving its dispersibility.
The water-dispersible resin may be an emulsion in an aqueous dispersion medium.
Among water-dispersible resins, polyesters having acid groups or their salts, polyurethanes having acid groups or their salts, emulsion-like polyesters, emulsion-like polyesters, etc. Polyurethane is preferred, and polyester having an acid group or a salt thereof is more preferred.
One type of water-dispersible resin may be used alone, or two or more types may be used in combination.

When adding a binder resin, the content ratio of the binder resin such as water-dispersible resin in the organic solvent dispersion of the highly conductive composite is 100 parts by mass or more based on 100 parts by mass of the solid content of the highly conductive composite. The content is preferably 10,000 parts by mass or less, more preferably 100 parts by mass or more and 5,000 parts by mass or less, and even more preferably 100 parts by mass or more and 1,000 parts by mass or less. If the content ratio of the binder resin is equal to or higher than the lower limit value, the adhesion of the conductive layer to the base material will be improved, and the strength of the conductive layer will be improved. If the content ratio of the binder resin is below the upper limit value, it is possible to suppress a decrease in conductivity due to a decrease in the relative content of the highly conductive composite.

Examples of water-soluble organic solvents include alcohol solvents (excluding the diol compounds mentioned above), ketone solvents, and ester solvents. One type of water-soluble organic solvent may be used alone, or two or more types may be used in combination.
The water-soluble organic solvent preferably has a boiling point lower than the boiling point of the diol at standard pressure. When the coating film of the organic solvent dispersion is dried, the water-soluble organic solvent evaporates first, so that a uniform conductive layer can be formed.

The high conductivity agent is a component that further improves the conductivity of the conductive layer. Here, the aforementioned π-conjugated conductive polymer, polyanion, diol compound, binder resin, and water-soluble organic solvent are not classified as high-conductivity agents.
The high conductivity agent is a saccharide, a nitrogen-containing aromatic cyclic compound, a compound having three or more hydroxy groups, a compound having one or more hydroxy groups and one or more carboxy group, a compound having an amide group, Preferably, it is at least one compound selected from the group consisting of imide group-containing compounds and lactam compounds.
The number of highly conductive agents contained in the organic solvent dispersion of the highly conductive composite may be one type, or two or more types.

When adding a high conductivity agent, the content ratio of the high conductivity agent in the organic solvent dispersion of the highly conductive composite is 1 part by mass or more and 10,000 parts by mass or less with respect to 100 parts by mass of the highly conductive composite. It is preferably 10 parts by mass or more and 5000 parts by mass or less, more preferably 100 parts by mass or more and 2500 parts by mass or less. If it is above the lower limit, the conductivity improvement effect by adding the high conductivity agent will be fully exhibited, and if it is below the upper limit, the conductivity will be reduced due to the decrease in the concentration of the π-conjugated conductive polymer. It is possible to prevent deterioration and decrease in transparency.

Examples of other additives include surfactants, inorganic conductive agents, antifoaming agents, coupling agents, antioxidants, and ultraviolet absorbers.
Examples of the surfactant include nonionic, anionic, and cationic surfactants, and nonionic surfactants are preferred from the viewpoint of storage stability. Additionally, polymeric surfactants such as polyvinyl alcohol and polyvinylpyrrolidone may be added.
Examples of the inorganic conductive agent include metal ions, conductive carbon, and the like. Note that metal ions can be generated by dissolving metal salts in water.
Examples of antifoaming agents include silicone resins, polydimethylsiloxanes, and silicone resins.
Examples of the coupling agent include silane coupling agents having a vinyl group, an amino group, an epoxy group, and the like.
Examples of the antioxidant include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, vitamins, and the like.
Examples of UV absorbers include benzotriazole UV absorbers, benzophenone UV absorbers, salicylate UV absorbers, cyanoacrylate UV absorbers, oxanilide UV absorbers, hindered amine UV absorbers, benzoate UV absorbers, etc. can be mentioned.

[Viscosity of organic solvent dispersion of highly conductive composite]
The viscosity of the organic solvent dispersion of the highly conductive composite obtained by the production method of this embodiment is increased by adding the epoxy compound to the highly conductive composite, and is further increased by the viscosity of the diol compound to be mixed. can also be adjusted. From the viewpoint of improving the printing suitability of the organic solvent dispersion, the viscosity of the organic solvent dispersion at 25° C. is preferably 500 cP (centipoise) or more and 5000 cP or less, more preferably 800 cP or more and 3000 cP or less, and even more preferably 1000 cP or more and 2000 cP or less. preferable. Here, the viscosity is a value measured at 25° C. using a B-type viscometer. When the viscosity is within the above range, the printability of the organic solvent dispersion of the highly conductive composite, particularly the printability for screen printing, becomes higher.
Here, 1 Pa·s (pascal second)=1000 cP (centipoise).

<Effect>
According to the method for producing an organic solvent dispersion of a highly conductive composite of the present invention, almost all of the conductive composite contained in the liquid mixture can be recovered as a precipitate of the highly conductive composite. In other words, a highly conductive composite can be obtained with a high yield of 90 to 100% by mass. It is presumed that the reason why the highly conductive composite is precipitated in the liquid mixture is that the highly conductive composite is difficult to dissolve in organic solvents other than diol compounds.
Surprisingly, by using the highly conductive composite deposited by the production method of the present invention, it is possible to form a conductive layer with superior conductivity than when using a conventional conductive composite (as described below). (See Examples and Comparative Examples). We believe that the difference in chemical composition between the highly conductive composite after precipitation and the conventional conductive composite is due to the presence or absence, if any, of an extremely small amount of organic solvent attached to the highly conductive composite at the molecular level. It will be done. It is thought that the difference in physicochemical properties rather than the chemical composition influences the difference in conductivity.
In the method for producing an organic solvent dispersion of a highly conductive composite of the present invention, since the highly conductive composite and the diol compound can be mixed in any ratio, the viscosity is suitably high and the dispersibility is excellent. A dispersion liquid can be easily obtained. The organic solvent dispersion having a viscosity within the above-described preferred range has high printability, particularly screen printing suitability.
In addition, in the present invention, by adding an epoxy compound to the highly conductive composite, the viscosity of the organic solvent dispersion of the highly conductive composite is further increased, and there is no printing bleed during screen printing. In particular, printing unevenness (fading) can be reduced.
Furthermore, as shown in Examples and Comparative Examples below, the organic solvent dispersion of the highly conductive composite of the present invention not only utilizes the high viscosity inherent to the diol compound; By adding an epoxy compound to the highly conductive composite, it has achieved a high viscosity suitable for screen printing. As described in formula (A1) and formula (A2) above, the mechanism for this is that by adding an epoxy compound to the highly conductive composite, a hydroxyl group derived from the epoxy compound is formed in the polyanion, and this hydroxyl group and It is presumed that the interaction with the diol compound, such as hydrogen bonding, is the reason why the high viscosity was achieved.

≪Method for manufacturing conductive film≫
The method for producing a conductive film according to the second embodiment of the present invention includes coating an organic solvent dispersion of the highly conductive composite obtained by the production method according to the first embodiment on at least one surface of a film base material to form a conductive film. A method for producing a conductive film, which method includes drying a coated film.

Examples of the film base material used in this embodiment include a plastic film.
Examples of film base resins constituting plastic films include ethylene-methyl methacrylate copolymer resin, ethylene-vinyl acetate copolymer resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyethylene terephthalate, and polybutylene terephthalate. , polyethylene naphthalate, polyacrylate, polycarbonate, polyvinylidene fluoride, polyarylate, styrene elastomer, polyester elastomer, polyether sulfone, polyetherimide, polyether ether ketone, polyphenylene sulfide, polyimide, cellulose triacetate, cellulose acetate propio Examples include Nate. Among these film base resins, polyethylene terephthalate is preferred because it is inexpensive and has excellent mechanical strength.
The film base resin may be amorphous or crystalline.
Further, the film base material may be unstretched or stretched.
Further, the film base material may be subjected to surface treatment such as corona discharge treatment, plasma treatment, flame treatment, etc. in order to further improve the adhesion of the conductive layer to be formed.

The average thickness of the film base material is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 200 μm or less. If the average thickness of the film base material is greater than or equal to the lower limit, it will be difficult to break, and if it is less than or equal to the upper limit, sufficient flexibility can be ensured as a film.
The thickness of the film base material in this specification is a value obtained by measuring the thickness of 10 randomly selected cross sections and averaging the measured values.

(Coating process)
Examples of methods for applying the organic solvent dispersion of the highly conductive composite onto the film substrate include gravure coater, roll coater, curtain flow coater, spin coater, bar coater, reverse coater, kiss coater, fountain coater, and rod coater. Coating methods using coaters such as air doctor coater, knife coater, blade coater, cast coater, screen coater, spraying methods using sprayers such as air spray, airless spray, rotor dampening, immersion methods such as dipping, etc. can be applied.
Among the above, a bar coater is sometimes used because it can be easily applied. In bar coaters, the coating thickness varies depending on the type, and in commercially available bar coaters, a number is assigned to each type, and the larger the number, the thicker the coating can be.
The amount of the dispersion applied to the film base material is not particularly limited, but from the viewpoint of obtaining good conductivity, the solid content should be in the range of 0.1 g/m ² or more and 10.0 g/m ² or less. is preferred.

Printing may be applied as a method of coating the organic solvent dispersion of the highly conductive composite onto the film base material. When the organic solvent dispersion has a suitable viscosity, good printing without bleeding or blurring can be easily performed. Specific printing methods include, for example, screen printing, gravure printing, flexo printing, offset printing, letterpress printing, inkjet printing, and the like. Among these, screen printing is preferred because it is easy to thicken the coating film, that is, the conductive layer.

The coating film may be applied to the entire surface of the film base material, may be formed only on a part of the surface, or may be formed in an arbitrary pattern on the film base material. Examples of the pattern include electrodes, wiring, electric circuits, and the like. By applying the coating by printing, pattern formation becomes easier.

(drying process)
Examples of methods for drying the coating film formed on the film base include heating drying, vacuum drying, and the like. For heating and drying, for example, a conventional method such as hot air heating or infrared heating can be used. When heat drying is applied, the heating temperature is appropriately set depending on the dispersion medium used, and can be set, for example, to 50° C. or more and 150° C. or less. Here, the heating temperature is the set temperature of the drying device. The drying time when drying at the above temperature can be, for example, 30 seconds or more and 5 minutes or less.

≪Conductive film≫
A third aspect of the present invention provides a conductive layer comprising a hardened layer of an organic solvent dispersion of a highly conductive composite obtained by the manufacturing method of the first aspect, on at least one surface of a film base material. It's a film. The conductive film of this aspect can be manufactured by the manufacturing method of the second aspect.

The conductive film obtained by this embodiment includes a film base material and a conductive layer formed on at least one surface of the film base material. The conductive layer contains the highly conductive composite of the first embodiment. Moreover, a part of the diol compound contained in the coating film at the time of forming the conductive layer may remain in the conductive layer.

The average thickness of the conductive layer of the conductive film of this embodiment is, for example, preferably 10 nm or more and 30 μm or less, more preferably 30 nm or more and 10 μm or less. If the average thickness of the conductive layer is not less than the lower limit value, sufficiently high conductivity can be exhibited, and if the average thickness is not more than the upper limit value, the adhesion of the conductive layer to the film base material is improved.
The thickness of the conductive layer is a value measured using an optical microscope or an electron microscope on a cross section of the conductive layer at an arbitrarily selected location.
The conductive layer may be formed in a pattern on the surface of the film base material, or may be formed on the entire surface of the film base material.

The surface resistance value of the conductive layer of the conductive film of this embodiment is, for example, preferably 1×10 ¹ Ω/□ or more and 1×10 ³ Ω/□ or less, and 1×10 ¹ Ω/□ or more and 5×10 ² Ω/ It is more preferably □ or less, and even more preferably 1×10 ¹ Ω/□ or more and 1×10 ² Ω/□ or less.

<Effect>
Since the conductive layer of the conductive film of the present invention contains a highly conductive composite, it has better conductivity than a conductive layer containing a conventional conductive composite. In addition, since the highly conductive composite is added with an epoxy compound, even when the conductive layer is formed by screen printing, there is no printing bleed and printing unevenness (fading) is reduced.

(Production Example 1) Synthesis of polystyrene sulfonic acid 206 g of sodium styrene sulfonate was dissolved in 1000 ml of ion-exchanged water, and while stirring at 80°C, 1.14 g of ammonium persulfate oxidizing agent solution previously dissolved in 10 ml of water was added. The solution was added dropwise for 20 minutes and stirred for 12 hours.
1,000 ml of sulfuric acid diluted to 10% by mass was added to the obtained sodium polystyrene sulfonate-containing solution, and about 1,000 ml of the solvent in the polystyrene sulfonic acid-containing solution was removed by ultrafiltration. Next, 2000 ml of ion-exchanged water was added to the residual liquid, about 2000 ml of the solvent was removed by ultrafiltration, and the polystyrene sulfonic acid was washed with water. This water washing operation was repeated three times.
Water in the resulting solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid.

(Production Example 2) Synthesis of conductive polymer aqueous dispersion A solution of 14.2 g of 3,4-ethylenedioxythiophene and 36.7 g of polystyrene sulfonic acid dissolved in 2000 ml of ion-exchanged water was mixed at 20°C. I let it happen.
While stirring the resulting mixed solution at 20° C., 29.64 g of ammonium persulfate and 8.0 g of ferric sulfate oxidation catalyst solution dissolved in 200 ml of ion-exchanged water were slowly added, The reaction was stirred for 3 hours.
2000 ml of ion-exchanged water was added to the resulting reaction solution, and about 2000 ml of the solvent was removed by ultrafiltration. This operation was repeated three times.
Then, 200 ml of sulfuric acid diluted to 10% by mass and 2000 ml of ion-exchanged water were added to the obtained solution, and about 2000 ml of the solvent was removed by ultrafiltration. 2000 ml of ion-exchanged water was added to the residual liquid, and about 2000 ml of the solvent was removed by ultrafiltration. This operation was repeated three times.
Further, 2000 ml of ion-exchanged water was added to the obtained solution, and about 2000 ml of the solvent was removed by ultrafiltration. This operation was repeated five times to obtain a 1.2% polystyrene sulfonic acid-doped poly(3,4-ethylenedioxythiophene) (PEDOT-PSS aqueous dispersion) solution.

(Example 1)
A mixture of 100 g of PEDOT-PSS aqueous dispersion (solid content: 1.2 g) of Production Example 2, 12.5 g of methanol, and 200 g of methyl ethyl ketone was heated and stirred at 60° C. for 3 hours. Next, when the mixed solution was returned to room temperature (20 to 25°C) and left to stand for 1 hour, the highly conductive composite composed of PEDOT-PSS precipitated in the mixed solution was precipitated, and the upper layer (supernatant) was It became a transparent liquid.
Next, 5.0 g of 1,2-butylene oxide (hereinafter referred to as butylene oxide) was added to the mixed solution in which the highly conductive composite was precipitated, and the mixture was stirred for 1 hour to precipitate the highly conductive composite. Butylene oxide was added to the product.
Subsequently, the mixed solution was filtered to obtain 2.3 g of a highly conductive composite to which the epoxy compound was added. Collection of the highly conductive composite by this filtration process was completed in 5 minutes or less.
The filtered highly conductive composite was washed with 100 g of acetone and dried. 237.7 g of propylene glycol was added to 2.3 g of this highly conductive composite and dispersed using a high-pressure homogenizer to obtain a propylene glycol dispersion of the highly conductive composite. Table 1 shows the results of measuring the viscosity of this dispersion using the method described below.
Next, using a 350 mesh (gauge thickness: 36 μm, aperture ratio: 60%) screen plate, the above propylene glycol dispersion was continuously printed on 10 sheets of PET film (Toray Industries, Ltd., Lumirror T60). Then, it was dried at 150° C. for 3 minutes to obtain 10 conductive films. Table 1 shows the surface resistance value and light transmittance of the 10th sheet of the continuously obtained conductive film measured by the method described below, as well as the results of screen printing (printability).

(Example 2)
In Example 1, the epoxy compound added to the mixed solution in which the highly conductive composite was precipitated was changed to 5.0 g of 1,2-epoxy-4-vinylcyclohexane, and the highly conductive composite 2 to which this epoxy compound was added was A dispersion of a highly conductive composite was prepared in the same manner as in Example 1, except that 0.5 g of the conductive film 10 was collected by filtration, and the amount of propylene glycol added was changed to 237.5 g. I made a sheet. The results are shown in Table 1.

(Example 3)
A mixture of 100 g of PEDOT-PSS aqueous dispersion (solid content: 1.2 g) of Production Example 2, 15.0 g of methanol, and 200 g of methyl ethyl ketone was heated and stirred at 60° C. for 3 hours. Next, when the mixed solution was returned to room temperature (20 to 25°C) and left to stand for 1 hour, the highly conductive composite composed of PEDOT-PSS precipitated in the mixed solution was precipitated, and the upper layer (supernatant) was It became a transparent liquid.
Next, 5.0 g of glycidol was added to the mixed solution in which the highly conductive composite was precipitated, and the mixture was stirred for 1 hour to add glycidol to the precipitate of the highly conductive composite.
Subsequently, the mixed liquid was filtered to obtain 2.5 g of a highly conductive composite to which the epoxy compound was added. Collection of the highly conductive composite by this filtration process was completed in 5 minutes or less.
The filtered highly conductive composite was washed with 100 g of acetone and dried. 237.5 g of propylene glycol was added to 2.5 g of this highly conductive composite and dispersed with a high-pressure homogenizer to obtain a propylene glycol dispersion of the highly conductive composite. Table 1 shows the results of measuring the viscosity of this dispersion using the method described below.
Next, using a 350-mesh screen plate, the above propylene glycol dispersion was continuously printed on 10 sheets of PET film (Toray Industries, Inc., Lumirror T60), dried at 150°C for 3 minutes, and made conductive. Ten films were obtained. Table 1 shows the surface resistance value and light transmittance of the 10th sheet of the continuously obtained conductive film measured by the method described below, as well as the results of screen printing (printability).

(Example 4)
In Example 3, the epoxy compound added to the mixed solution in which the highly conductive composite was precipitated was changed to 5.0 g of triglycidyl isocyanurate, and 2.5 g of the highly conductive composite to which this epoxy compound was added was collected by filtration. Except for the above, a highly conductive composite dispersion was prepared in the same manner as in Example 3, and 10 conductive films were produced. The results are shown in Table 1.

(Example 5)
Ten conductive films were produced in the same manner as in Example 3, except that propylene glycol was changed to ethylene glycol to obtain an ethylene glycol dispersion of a highly conductive composite. The results are shown in Table 1.

(Example 6)
Ten conductive films were produced in the same manner as in Example 3, except that propylene glycol was changed to diethylene glycol to obtain a diethylene glycol dispersion of a highly conductive composite. The results are shown in Table 1.

(Example 7)
To 45 g of the propylene glycol dispersion of the highly conductive composite obtained in Example 3, 5 g of Pluscoat RZ-105 (manufactured by Gooh Kagaku Co., Ltd., solid content 25% by mass), which is a water-dispersible polyester, was added and mixed. Got the paint. Using this paint, the viscosity was measured in the same manner as in Example 1, and 10 conductive films were produced. The results are shown in Table 1.

(Comparative example 1)
A mixture of 100 g (solid content 1.2 g) of PEDOT-PSS aqueous dispersion of Production Example 2 and 215 g of isopropanol was heated and stirred at 60° C. for 3 hours. Next, the mixed solution was returned to room temperature and allowed to stand for 1 hour, but the conductive composite was not precipitated, and it was confirmed that the mixed solution was uniform. 5.0 g of butylene oxide was added to this mixed solution and stirred for 1 hour to add and precipitate butylene oxide to the conductive composite. Subsequently, 2.0 g of a conductive composite to which the above epoxy compound was added was obtained by filtration. It took 5 hours to separate the precipitate through this filtration process.
The conductive composite collected by filtration was washed with 100 g of acetone and dried. 238.0 g of propylene glycol was added to 2.0 g of this conductive composite and dispersed with a high-pressure homogenizer to obtain a propylene glycol dispersion of the conductive composite. Table 1 shows the results of measuring the viscosity of this dispersion using the method described below.
Next, using a 350-mesh screen plate, the above propylene glycol dispersion was continuously printed on 10 sheets of PET film (Toray Industries, Inc., Lumirror T60), dried at 150°C for 3 minutes, and made conductive. Ten films were obtained. Table 1 shows the surface resistance value and light transmittance of the 10th sheet of the continuously obtained conductive film measured by the method described below, as well as the results of screen printing (printability).

(Comparative example 2)
In Comparative Example 1, the epoxy compound added to the mixed solution containing the conductive composite was changed to 5.0 g of 1,2-epoxy-4-vinylcyclohexane, and the conductive composite precipitated by the addition of this epoxy compound. A propylene glycol dispersion of a conductive composite was prepared in the same manner as in Comparative Example 1, except that 2.1 g was filtered for 5 hours and the amount of propylene glycol added was changed to 237.9 g. , 10 conductive films were produced. The results are shown in Table 1.

(Comparative example 3)
In Comparative Example 1, an attempt was made to generate a precipitate of a conductive composite in the same manner as in Comparative Example 1 except that 5.0 g of butylene oxide was changed to 5.0 g of glycidol. However, since no precipitate was formed, the production of the conductive film was discontinued.

(Comparative example 4)
In Comparative Example 1, a precipitate of a conductive composite to which an epoxy compound was added was formed in the same manner as in Comparative Example 1, except that 5.0 g of butylene oxide was changed to 5.0 g of triglycidyl isocyanurate. However, although an attempt was made to remove the precipitate by filtration, the filter paper became clogged and the precipitate could not be collected even after 5 hours, so the production of the conductive film was discontinued.

(Comparative example 5)
A mixture of 100 g of PEDOT-PSS aqueous dispersion (solid content: 1.2 g) of Production Example 2, 12.5 g of methanol, and 200 g of methyl ethyl ketone was heated and stirred at 60° C. for 3 hours. Next, when the mixed solution was returned to room temperature (20 to 25°C) and left to stand for 1 hour, the highly conductive composite composed of PEDOT-PSS precipitated in the mixed solution was precipitated, and the upper layer (supernatant) was It became a transparent liquid.
Subsequently, the mixed solution was filtered to obtain 1.2 g of a highly conductive composite. Collection of the highly conductive composite by this filtration process was completed in 5 minutes or less.
The filtered highly conductive composite was washed with 100 g of acetone and dried. 238.8 g of propylene glycol was added to 1.2 g of this highly conductive composite and dispersed with a high-pressure homogenizer to obtain a propylene glycol dispersion of the highly conductive composite. Table 1 shows the results of measuring the viscosity of this dispersion using the method described below.
Next, using a 350-mesh screen plate, the above propylene glycol dispersion was continuously printed on 10 sheets of PET film (Toray Industries, Inc., Lumirror T60), dried at 150°C for 3 minutes, and made conductive. Ten films were obtained. Table 1 shows the surface resistance value and light transmittance of the 10th sheet of the continuously obtained conductive film measured by the method described below, as well as the results of screen printing (printability).

(Comparative example 6)
Ten conductive films were produced in the same manner as in Comparative Example 5, except that methanol was used instead of propylene glycol to obtain a methanol dispersion of a highly conductive composite. The results are shown in Table 1.

<Evaluation>
[viscosity]
The viscosity of the organic solvent dispersion of the highly conductive composite or conductive composite prepared in each example was measured at 25° C. using a B-type viscometer (manufactured by A&D, model number: SV-10).

[Surface resistance value]
In each example, a resistivity meter (Lowresta manufactured by Mitsubishi Chemical Analytech) was used to measure the surface resistance value of the printed area of the 10th conductive film that was continuously screen printed. In the measurement, the applied voltage was 10V. "Ω/□" in Table 1 showing each measurement result means ohm per square.
The smaller the surface resistance value (unit: Ω/□), the higher the conductivity.

[Light transmittance]
In each example, the total light transmittance of the printed area of the 10th conductive film that was continuously screen printed was measured using a haze meter (manufactured by Nippon Denshoku Industries, model number: NDH-5000) in accordance with JIS K7136:2000. It was measured using The higher the total light transmittance (unit: %), the higher the transparency of the conductive layer and the higher the dispersibility of the highly conductive composite in the conductive layer. In the table, the results are shown in the "Transmittance (%)" column.

[Printability]
In each example, the 10th conductive film that was continuously screen printed was visually observed to evaluate the presence or absence of printing unevenness (fading). If there was no uneven printing, it was evaluated as good. If there is any blurring, it is written as "fading" in the table.
In each example, the boundary line between the screen-printed area and the non-printed area on the first conductive film that was continuously screen-printed was visually observed, and the presence or absence of printing blur was evaluated. It was evaluated as good if there was no printing bleed. If there was bleeding, it was written as "bleeding" in the table.

From the above results, the highly conductive composite to which the epoxy compound added obtained by the production method according to the present invention can be easily dispersed in a diol compound, and the organic solvent dispersion containing this highly conductive composite can be easily dispersed. It is clear that the liquid (paint) exhibits excellent printability without printing unevenness or printing bleed, and that the conductive layer consisting of the cured layer of the paint has excellent conductivity and good transparency.
On the other hand, Comparative Examples 1 and 2 do not contain a highly conductive composite and therefore have poor conductivity, and Comparative Example 5 contains a highly conductive composite but does not have an epoxy compound added, resulting in uneven printing. On the other hand, Comparative Example 6 contains a highly conductive composite but does not contain a diol compound, so the viscosity is low, the conductivity is poor, and printing smear occurs.

Claims (16)

After obtaining a mixed solution of an aqueous dispersion of a conductive composite containing a π-conjugated conductive polymer and a polyanion and an organic solvent, and depositing a highly conductive composite in the mixed solution,
Highly conductive, comprising adding an epoxy compound to the mixed liquid, separating the highly conductive composite to which the epoxy compound has been added, and adding a diol compound to the obtained highly conductive composite. A method for producing an organic solvent dispersion of a composite. The method for producing an organic solvent dispersion of a highly conductive composite according to claim 1, wherein the content of the organic solvent contained in the mixed solution is 50% by mass or more based on the total mass of the mixed solution. . The method for producing an organic solvent dispersion of a highly conductive composite according to claim 1 or 2, wherein the organic solvent contains at least one of a ketone solvent and an alcohol solvent. 4. The method for producing an organic solvent dispersion of a highly conductive composite according to claim 3, wherein the organic solvent contains a ketone solvent, and the ketone solvent contains methyl ethyl ketone. The method for producing an organic solvent dispersion of a highly conductive composite according to claim 3, wherein the organic solvent contains an alcohol solvent, and the alcohol solvent contains methanol. The method for producing an organic solvent dispersion of a highly conductive composite according to claim 1 or 2, wherein the organic solvent contains methyl ethyl ketone and methanol. The organic solvent dispersion of the highly conductive composite according to any one of claims 1 to 6, wherein the mixed solution is heated to 40° C. or higher when depositing the highly conductive composite in the mixed solution. Production method. When depositing the highly conductive composite in the mixed liquid, the content of at least one of an acid and a base other than the polyanion in the mixed liquid is 0.1 mass with respect to the total mass of the mixed liquid. % or less, a method for producing an organic solvent dispersion of a highly conductive composite according to any one of claims 1 to 7. The method for producing an organic solvent dispersion of a highly conductive composite according to any one of claims 1 to 8, wherein the method for separating the highly conductive composite is filtration. The method for producing an organic solvent dispersion of a highly conductive composite according to any one of claims 1 to 9, wherein the diol compound contains propylene glycol, ethylene glycol, or diethylene glycol. The method for producing an organic solvent dispersion of a highly conductive composite according to any one of claims 1 to 10, wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene). The method for producing an organic solvent dispersion of a highly conductive composite according to any one of claims 1 to 11, wherein the polyanion is polystyrene sulfonic acid. A method for producing an organic solvent dispersion of a highly conductive composite according to any one of claims 1 to 12, further comprising mixing a binder component. The method for producing an organic solvent dispersion of a highly conductive composite according to claim 13, wherein the binder component is a water-dispersible resin. Coating an organic solvent dispersion of the highly conductive composite obtained by the production method according to any one of claims 1 to 14 on at least one surface of the film base material, and drying the formed coating film. A method for producing a conductive film, comprising: The method for producing a conductive film according to claim 15, wherein the method for applying the organic solvent dispersion of the highly conductive composite is screen printing.