JP7519932B2 - Conductive polymer dispersion, conductive laminate and method for producing same - Google Patents

Description

The present invention relates to a conductive polymer dispersion containing a π-conjugated conductive polymer, a conductive laminate, and a method for producing the same.

As a technique for manufacturing electronic devices, a conductive layer may be formed by applying a conductive polymer dispersion liquid containing a π-conjugated conductive polymer to the surface of a film or glass substrate. π-conjugated conductive polymers are used as materials for forming conductive layers because of their excellent conductivity and transparency.
A conductive layer containing a π-conjugated conductive polymer may be required to have resistance to rubbing (abrasion resistance), and silica may be included to improve the abrasion resistance. When applying a conductive polymer dispersion containing silica (silicate), the dried silica may be an obstacle. To prevent this, a method for manufacturing a conductive laminate in which a conductive layer is formed by spray coating without using a coater has been disclosed (Patent Document 1).

JP 2020-121256 A

When a conductive film with a conductive layer containing silica is stretched, the conductive layer may crack and lose its conductivity. For this reason, there is a demand for a conductive film that does not contain silica but has improved abrasion resistance of the conductive layer and has excellent abrasion resistance and conductivity even after stretching.

The present invention provides a conductive polymer dispersion that can easily form a conductive layer with excellent abrasion resistance and conductivity, as well as a conductive laminate using the same and a method for producing the same.

[1] A conductive polymer dispersion liquid containing a conductive complex including a π-conjugated conductive polymer and a polyanion, an unsaturated aliphatic alcohol compound having an unsaturated bond between carbon atoms and a hydroxyl group in the molecule, a dispersion medium, and polyvinyl alcohol.
[2] The conductive polymer dispersion liquid according to [1], wherein the unsaturated aliphatic alcohol compound is a diol.
[3] The conductive polymer dispersion liquid according to [1] or [2], wherein the unsaturated aliphatic alcohol compound has 4 or more and 8 or less carbon atoms.
[4] The conductive polymer dispersion according to [1], wherein the unsaturated aliphatic alcohol compound includes at least one selected from the group consisting of cis-2-butene-1,4-diol, trans-2-butene-1,4-diol, 2-butyne-1,4-diol, and 2,4-hexadiyne-1,6-diol.
[5] The conductive polymer dispersion according to any one of [1] to [4], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene) or the polyanion is polystyrenesulfonic acid.
[6] The conductive polymer dispersion liquid according to any one of [1] to [5], further comprising one or more polyvalent carboxylic acid compounds.
[7] The conductive polymer dispersion liquid according to [6], wherein the polyvalent carboxylic acid compound includes thiodipropionic acid or tris(2-carboxyethyl)isocyanurate.
[8] A method for producing a conductive laminate, comprising applying the conductive polymer dispersion according to any one of [1] to [7] to at least a part of a surface of a substrate.
[9] The method for producing a conductive laminate according to [8], wherein the substrate is an amorphous film substrate, the method comprising: applying the conductive polymer dispersion to at least a partial surface of the amorphous film substrate to obtain a coated film; and heating and stretching the coated film to obtain a stretched film.
[10] A conductive laminate comprising a substrate and a conductive layer formed on at least a part of the surface of the substrate, the conductive layer being a cured layer of the conductive polymer dispersion according to any one of [1] to [7].

According to the conductive polymer dispersion of the present invention, a conductive layer having excellent abrasion resistance and conductivity even after being subjected to a stretching treatment can be easily formed.
The conductive layer in the conductive laminate of the present invention has excellent abrasion resistance and conductivity even after being subjected to a stretching treatment.
According to the method for producing a conductive laminate of the present invention, the above-mentioned conductive laminate can be easily produced.

This invention is believed to contribute to SDG Goal 12, "Responsible Consumption and Production."

In this specification and claims, the lower and upper limits of the numerical ranges indicated with "~" are considered to be included in the numerical range.

≪Conductive polymer dispersion liquid≫
The first aspect of the present invention is a conductive composite including a π-conjugated conductive polymer and a polyanion, an unsaturated aliphatic alcohol compound having an unsaturated bond between carbon atoms and a hydroxyl group in the molecule, and a dispersion medium. and polyvinyl alcohol.

[Conductive composite]
The conductive complex contained in the conductive polymer dispersion of this embodiment contains a π-conjugated conductive polymer and a polyanion. The polyanion in the conductive complex is doped into the π-conjugated conductive polymer to form a conductive complex having electrical conductivity.
In the polyanion, only a part of the anionic groups is doped into the π-conjugated conductive polymer, and there are excess anionic groups that are not involved in the doping. Since the excess anionic groups are hydrophilic groups, the conductive composite has water dispersibility.

(π-conjugated conductive polymer)
The π-conjugated conductive polymer may be an organic polymer whose main chain is composed of a π-conjugated system, and examples thereof include polypyrrole-based conductive polymers, polythiophene-based conductive polymers, polyacetylene-based conductive polymers, polyphenylene-based conductive polymers, polyphenylenevinylene-based conductive polymers, polyaniline-based conductive polymers, polyacene-based conductive polymers, polythiophenevinylene-based 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.

Examples of 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), and poly(3-iodothiophene). thiophene), 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), oxythiophene), poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3,4-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-di dodecyloxythiophene), 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), and poly(3-methyl-4-carboxybutylthiophene).
Examples of polypyrrole-based conductive polymers include polypyrrole, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-ethylpyrrole), poly(3-n-propylpyrrole), poly(3-butylpyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3-dodecylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-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-anilinesulfonic acid), and poly(3-anilinesulfonic acid).
Among these π-conjugated conductive polymers, poly(3,4-ethylenedioxythiophene) is particularly preferred because of its excellent conductivity, transparency and heat resistance.
The conductive composite may contain one type of π-conjugated conductive polymer, or two or more types of polymers.

(Polyanion)
A polyanion is a polymer having two or more monomer units each having an anionic group in the molecule. The anionic group of the polyanion functions as a dopant for a π-conjugated conductive polymer, thereby improving 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 polymers having a sulfo group, such as polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacrylic acid esters having a sulfo group, polymethacrylic acid esters having a sulfo group (e.g., poly(4-sulfobutyl methacrylate, polysulfoethyl methacrylate, polymethacryloyloxybenzenesulfonic acid), poly(2-acrylamido-2-methylpropanesulfonic acid), and polyisoprene sulfonic acid; and polymers having a carboxy group, such as polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacrylic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropanecarboxylic acid), and polyisoprene carboxylic acid. The polyanion may be a homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized.
Among these polyanions, polymers having a sulfo group are preferred, and polystyrene sulfonic acid is more preferred, since they can provide higher electrical conductivity.
The polyanions may be used alone or in combination of two or more kinds.
The mass average molecular weight of the polyanion is preferably from 20,000 to 1,000,000, and more preferably from 100,000 to 500,000. The mass average molecular weight is an average molecular weight based on mass measured by gel filtration chromatography and calculated in terms of pullulan.

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

The content of the conductive complex relative to the total mass of the conductive polymer dispersion of this embodiment is preferably from 0.01% by mass to 5% by mass, more preferably from 0.1% by mass to 3% by mass, and even more preferably from 0.3% by mass to 1.5% by mass.
When the content is at least as high as the lower limit of the above range, the conductivity of the conductive layer formed by coating the conductive polymer dispersion can be further improved.
When it is equal to or less than the upper limit of the above range, the dispersibility of the conductive complex in the conductive polymer dispersion can be improved, and a uniform conductive layer can be formed.

[Unsaturated aliphatic alcohol compound]
The one or more unsaturated aliphatic alcohol compounds contained in the conductive polymer dispersion of this embodiment are alcohols having one or more double bonds or triple bonds between carbon atoms in the molecule and having one or more hydroxyl groups (hydroxyl groups) in the molecule.

From the viewpoint of further improving the abrasion resistance and conductivity of the conductive layer formed from the conductive polymer dispersion of this embodiment, the unsaturated aliphatic alcohol compound is preferably a diol having two hydroxyl groups.
From the same viewpoint, the unsaturated aliphatic alcohol compound preferably has 4 or more and 12 or less carbon atoms, more preferably 4 or more and 10 or less, even more preferably 4 or more and 8 or less, and particularly preferably 4 or more and 6 or less carbon atoms.
From the same viewpoint, the number of unsaturated bonds contained in the unsaturated aliphatic alcohol compound is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

The unsaturated aliphatic alcohol compound is preferably at least one selected from the group consisting of cis-2-butene-1,4-diol, trans-2-butene-1,4-diol, 2-butyne-1,4-diol, and 2,4-hexadiyne-1,6-diol.
Further examples include 3,6-dimethyl-4-octyne-3,6-diol, 2,5-dimethyl-3-hexyne-2,5-diol, and the like.

In the conductive polymer dispersion of this embodiment, the total content of the unsaturated aliphatic alcohol compounds relative to 100 parts by mass of the conductive complex is preferably 10 parts by mass or more and 1000 parts by mass or less, more preferably 30 parts by mass or more and 500 parts by mass or less, and even more preferably 150 parts by mass or more and 300 parts by mass or less. When the content is within the above preferred range, the effect of the present invention is even more excellent.

The content of the unsaturated aliphatic alcohol compound relative to the total mass of the conductive polymer dispersion of this embodiment is preferably 0.01 mass % or more and 10 mass % or less, more preferably 0.1 mass % or more and 1 mass % or less, and even more preferably 0.2 mass % or more and 0.5 mass % or less.
When the content is within the above range, the abrasion resistance and electrical conductivity of the conductive layer can be sufficiently improved.

[Dispersion medium]
Examples of the dispersion medium contained in the conductive polymer dispersion of this embodiment include water, an organic solvent, and a mixture of water and an organic solvent.
The unsaturated aliphatic alcohol compound does not fall under the category of the dispersion medium contained in the conductive polymer dispersion liquid of this embodiment.

Examples of the organic solvent include alcohol-based solvents, ether-based solvents, ketone-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents.
Examples of alcohol-based solvents include monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, allyl alcohol, propylene glycol monomethyl ether, and ethylene glycol monomethyl ether.
Examples of the ether solvent include diethyl ether, dimethyl ether, ethylene glycol, propylene glycol, and propylene glycol dialkyl ether.
Examples of the ketone solvent include diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisopropyl ketone, methyl ethyl ketone, acetone, and diacetone alcohol.
Examples of the ester solvent include ethyl acetate, propyl acetate, and butyl acetate.
Examples of aromatic hydrocarbon solvents include benzene, toluene, xylene, ethylbenzene, propylbenzene, and isopropylbenzene.
The organic solvents may be used alone or in combination of two or more kinds.

Since the conductive complex has high dispersibility in water, the dispersion medium of the conductive polymer dispersion of this embodiment is preferably an aqueous dispersion medium containing water.
The content ratio of water to the total dispersion medium contained in the conductive polymer dispersion liquid of this embodiment can be, for example, 50% by mass or more and 100% by mass or less, preferably 60% by mass or more and 100% by mass or less, and more preferably 70% by mass or more and 100% by mass or less. As the dispersion medium other than water, a monohydric alcohol is preferable.

[Polyvinyl alcohol]
The polyvinyl alcohol contained in the conductive polymer dispersion of this embodiment functions as a dispersant for the conductive complex and also has the function of improving the stretchability of the conductive layer formed on the substrate. In other words, the conductive layer containing polyvinyl alcohol easily follows the stretching of the film, and the conductive layer is less likely to crack or peel off, resulting in high conductivity. In addition, polyvinyl alcohol also plays a role as a binder resin in the conductive layer. Therefore, even if the film is not stretched, the conductive polymer dispersion contains polyvinyl alcohol, which can reduce defects in the conductive layer and improve conductivity.

Polyvinyl alcohol is generally produced by saponifying the acetyl group of polyvinyl acetate, but some acetyl groups may not be saponified. Therefore, polyvinyl alcohol may contain vinyl acetate units. The saponification degree of the polyvinyl alcohol used in this embodiment is preferably 70% or more and 100% or less. If the saponification degree of the polyvinyl alcohol is the lower limit or more, it can be easily dissolved in water.
The mass average molecular weight of the polyvinyl alcohol is preferably from 500 to 10,000, and more preferably from 1,000 to 5,000. When the mass average molecular weight of the polyvinyl alcohol is equal to or more than the lower limit, the stretchability of the conductive layer can be sufficiently improved, and when it is equal to or less than the upper limit, the solubility in water can be improved.
The mass average molecular weight in this specification is a value measured by gel permeation chromatography using polystyrene as a standard substance.
The conductive polymer dispersion liquid may contain one type of polyvinyl alcohol or two or more types of polyvinyl alcohol.

The content of polyvinyl alcohol in the conductive polymer dispersion of this embodiment is, for example, preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 5 parts by mass or more and 1,000 parts by mass or less, still more preferably 10 parts by mass or more and 500 parts by mass or less, still more preferably 50 parts by mass or more and 300 parts by mass or less, and particularly preferably 100 parts by mass or more and 200 parts by mass or less, relative to 100 parts by mass of the conductive composite.
When the content is equal to or greater than the lower limit, the dispersibility of the conductive complex in the conductive polymer dispersion can be improved, and the stretchability of the conductive layer can be increased.
When the content is equal to or less than the upper limit, the decrease in electrical conductivity can be further suppressed.

[Polycarboxylic acid compound]
The polycarboxylic acid compound contained in the conductive polymer dispersion of this embodiment is a low molecular weight compound having two or more carboxy groups in the molecule. Polymers having carboxy groups in their side chains are not considered to be polycarboxylic acid compounds. The molecular weight of the polycarboxylic acid compound is preferably 50 to 1000, more preferably 100 to 500. The number of carboxy groups in the molecule of the polycarboxylic acid compound is preferably 2 to 5, more preferably 2 to 4, and even more preferably 2 to 3.

The arrangement of carboxy groups in the molecule of the polyvalent carboxylic acid compound is preferably an arrangement having one or more pairs of carboxy groups, which satisfies that an atom to which a first carboxy group is bonded (first α-atom) and an atom to which a second carboxy group is bonded (second α-atom) are not adjacent to each other and are not identical to each other, where the α-atom corresponds to a carbon atom, a nitrogen atom, a sulfur atom, or an oxygen atom.
The number of atoms connecting the first α-atom and the second α-atom in a single stroke is preferably from 1 to 10, more preferably from 2 to 8, and even more preferably from 3 to 7. Here, the atoms present on the single stroke connection include carbon atoms, nitrogen atoms, sulfur atoms, and oxygen atoms.

It is preferable that the polycarboxylic acid compound used in this embodiment does not have any hydroxyl groups other than the carboxyl groups.

The above-mentioned suitable polycarboxylic acid compound further improves the abrasion resistance of the conductive layer formed from the conductive polymer dispersion of this embodiment. Although the details of this mechanism have not been clarified, it is speculated that the polycarboxylic acid compound crosslinks the molecular chains of polyvinyl alcohol by forming an ester bond between the carboxyl group of the polycarboxylic acid compound and the hydroxyl group of polyvinyl alcohol. It is believed that the crosslinking increases the strength of the conductive layer and improves the abrasion resistance. In addition, in order for crosslinking to occur easily, it is believed that it is preferable that the carboxyl groups of the polycarboxylic acid compound are separated by several atoms or more. If the carboxyl groups are too close to each other, the rate at which crosslinks are formed may be reduced due to steric hindrance.

Suitable polycarboxylic acid compounds include, for example, tris(2-carboxyethyl) isocyanurate, 3,3'-thiodipropionic acid, phthalic acid, pyromellitic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, etc.

The content of the polyvalent carboxylic acid compound in the conductive polymer dispersion of this embodiment is preferably 1 part by mass or more and 200 parts by mass or less, more preferably 10 parts by mass or more and 100 parts by mass or less, and even more preferably 20 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the polyvinyl alcohol content.
When the content is equal to or greater than the lower limit, the abrasion resistance of the conductive layer formed can be further improved.
When the content is equal to or less than the upper limit, a decrease in the conductivity of the conductive layer formed can be prevented.

[Other additives]
The conductive polymer dispersion may contain other additives.
The additives are not particularly limited as long as the effects of the present invention can be obtained. For example, surfactants, inorganic conductive agents, antifoaming agents, coupling agents, antioxidants, ultraviolet absorbing agents, etc. can be used.
However, the additive is something other than the above-mentioned π-conjugated conductive polymer, polyanion, unsaturated aliphatic alcohol compound, dispersion medium, polyvinyl alcohol, and polyvalent carboxylic acid compound.
The surfactant may be a nonionic, anionic or cationic surfactant, with the nonionic surfactant being preferred from the standpoint of storage stability. A polymer surfactant such as polyvinylpyrrolidone may also be added.
Examples of the inorganic conductive agent include metal ions, conductive carbon, etc. Metal ions can be generated by dissolving a metal salt in water.
The antifoaming agent includes silicone resin, polydimethylsiloxane, silicone oil, and the like.
The coupling agent may be a silane coupling agent having an epoxy group, a vinyl group or an amino group.
Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, and sugars.
Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, oxanilide-based ultraviolet absorbers, hindered amine-based ultraviolet absorbers, and benzoate-based ultraviolet absorbers.

When the conductive polymer dispersion contains the additive, the content ratio is appropriately determined depending on the type of additive, but can be, for example, in the range of 0.001 parts by mass to 10 parts by mass per 100 parts by mass of the conductive composite.

<Method of producing conductive polymer dispersion>
Examples of a method for producing the conductive polymer dispersion of this embodiment include a method in which an unsaturated aliphatic alcohol compound, polyvinyl alcohol, a polycarboxylic acid compound, a dispersion medium, and the like are added to an aqueous dispersion of a conductive complex.
The aqueous dispersion of the conductive complex may be obtained by chemically oxidizing and polymerizing a monomer that forms a π-conjugated conductive polymer in an aqueous solution of a polyanion, or a commercially available product may be used.

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

<Conductive laminate>
A second aspect of the present invention is a conductive laminate comprising a substrate and a conductive layer formed on at least a partial surface of the substrate, the conductive layer being a cured layer of the conductive polymer dispersion of the first aspect.

[Conductive layer]
The conductive layer may be formed over the entire surface of any surface of the substrate, or over a portion of the entire surface. In the conductive film, it is preferable that a conductive layer of substantially uniform thickness is formed over substantially the entire surface of one surface or the other surface of the film substrate. When a conductive layer is formed only over a portion of the surface of the substrate, the conductive layer may be, for example, a fine conductive pattern such as a circuit or an electrode, or the conductive layer may be provided on the same surface and the conductive layer may be not provided on the same surface and may be roughly divided.

The average thickness of the conductive layer is, for example, preferably from 10 nm to 100 μm, more preferably from 20 nm to 50 μm, and even more preferably from 30 nm to 30 μm.
When the average thickness of the conductive layer is equal to or greater than the lower limit, high conductivity can be exhibited, and when the average thickness is equal to or less than the upper limit, the adhesion of the conductive layer to the substrate is further improved.

[Base material]
The substrate may be a substrate made of an insulating material or a substrate made of a conductive material. The shape of the substrate is not particularly limited, and examples thereof include a shape mainly having a flat surface, such as a film or a substrate.
Examples of insulating materials include glass, synthetic resin, and ceramics.
The conductive material may be a metal, a conductive metal oxide, carbon, or the like.

(Film substrate)
When a film substrate is used as the substrate, the conductive laminate becomes a conductive film.
The film substrate may be, for example, a plastic film made of a synthetic resin, such as ethylene-methyl methacrylate copolymer resin, ethylene-vinyl acetate copolymer resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacrylate, polycarbonate, polyvinylidene fluoride, polyarylate, styrene-based elastomer, polyester-based elastomer, polyethersulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyimide, cellulose triacetate, and cellulose acetate propionate.
From the viewpoint of improving the adhesion between the film substrate and the conductive layer, the synthetic resin for the film substrate is preferably a polyester resin, and among these, polyethylene terephthalate is preferable.

The synthetic resin for the film substrate may be either amorphous or crystalline.
The film substrate may be either unstretched or stretched.
The film substrate may be subjected to a surface treatment such as a corona discharge treatment, a plasma treatment, or a flame treatment in order to further improve the adhesion of the conductive layer.

The average thickness of the film substrate is preferably 5 μm to 500 μm, more preferably 20 μm to 200 μm. If the average thickness of the film substrate is equal to or more than the lower limit, the film is less likely to break, and if the average thickness is equal to or less than the upper limit, the film can have sufficient flexibility.
The average thickness of the film substrate is determined by measuring the thickness at 10 randomly selected points and averaging the measured values.

(Glass substrate)
Examples of the glass substrate include an alkali-free glass substrate, a soda-lime glass substrate, a borosilicate glass substrate, and a quartz glass substrate. If the substrate contains an alkali component, the conductivity of the conductive layer tends to decrease, so among the above glass substrates, an alkali-free glass is preferred. Here, the alkali-free glass refers to a glass composition in which the content of the alkali component is 0.1 mass% or less with respect to the total mass of the glass composition.

The average thickness of the glass substrate is preferably from 100 μm to 3000 μm, more preferably from 100 μm to 1000 μm. If the average thickness of the glass substrate is equal to or more than the lower limit, the glass substrate is less likely to break, and if the average thickness is equal to or less than the upper limit, the conductive laminate can be made thinner.
The average thickness of the glass substrate is determined by measuring the thickness at 10 randomly selected points and averaging the measured values.

<Method for manufacturing conductive laminate>
A third aspect of the present invention is a method for producing a conductive laminate, the method comprising: applying the conductive polymer dispersion of the first aspect to at least a part of a surface of a substrate to form a conductive layer. The conductive laminate of the second aspect can be produced by the production method of this aspect.

Methods for applying the conductive polymer dispersion to any surface of a substrate include, for example, methods using a coater such as a gravure coater, roll coater, curtain flow coater, spin coater, bar coater, reverse coater, kiss coater, fountain coater, rod coater, air doctor coater, knife coater, blade coater, cast coater, or screen coater; methods using a sprayer such as an air spray, airless spray, or rotor dampening; and immersion methods such as dipping.

The amount of the conductive polymer dispersion applied to the substrate is not particularly limited, but in consideration of uniform and even application and the electrical conductivity and film strength, the amount is preferably in the range of 0.01 g/ ^m2 or more and 10.0 g/ ^m2 or less in terms of solid content.

The conductive layer can be formed by drying the coating film made of the conductive polymer dispersion applied onto the substrate to remove at least a portion of the dispersion medium and curing the coating film.
Methods for drying the coating film include heat drying, vacuum drying, etc. Examples of heat drying that can be used include hot air heating and infrared heating.
When applying heat drying, the heating temperature is appropriately set depending on the dispersion medium used, but is usually within the range of 50° C. to 200° C. Here, the heating temperature is the set temperature of the drying device. A suitable drying time within the above heating temperature range is preferably 0.5 minutes to 30 minutes, more preferably 1 minute to 15 minutes.

In the method for producing the conductive laminate of this embodiment, the conductive film that has been subjected to the stretching treatment can be produced as follows.
The manufacturing method includes using an amorphous film substrate as the substrate, applying the conductive polymer dispersion to at least a part of the surface of the amorphous film substrate to obtain a coated film (coating step), and heating and stretching the coated film to obtain a stretched film (stretching step). The method may further include crystallizing the film heated in the stretching step (crystallization step). The coating step, stretching step, and crystallization step are described below.

[Coating process]
The film substrate used in this step is not particularly limited as long as it is amorphous, and for example, it can be arbitrarily selected from the film substrates described above.
In this step, the method for applying the coating material (conductive polymer dispersion) to the amorphous film substrate to obtain a coated film is not particularly limited, and for example, the above-mentioned coating methods can be applied.

[Stretching process]
The stretching step is a step of heating and stretching the coated film to obtain a stretched film. The dispersion medium contained in the coating material may be dried by heating in this step, or may be dried in a separate drying step before being subjected to this step.
By heating and stretching the coated film, a conductive film with a large area can be obtained even if the coated area is small, and the productivity of the conductive film is improved.
The stretching may be uniaxial or biaxial, but when a uniaxially stretched film is used as the amorphous film substrate, it is preferable to stretch in a direction perpendicular to the stretching direction. For example, when a uniaxially stretched film stretched along the longitudinal direction is used as the amorphous film substrate, it is preferable to stretch along the width direction.
The stretching ratio of the coated film is preferably from 2 to 20 times, more preferably from 3 to 15 times, and even more preferably from 4 to 10 times.

As the heating method, for example, a conventional method such as hot air heating or infrared heating can be used.
The heating temperature in the stretching step is preferably lower than the crystallization temperature of the amorphous film substrate, and is within the range of 50° C. to 150° C. Here, the heating temperature is the set temperature of the drying device. If the heating temperature in the stretching step is increased to the melting point of the material of the amorphous film substrate, the film may become too soft and stretching may become difficult.

[Crystallization step]
The crystallization step is a step in which the stretched film is heated and then cooled to crystallize the amorphous film substrate.
The heating temperature of the stretched film in the crystallization step is equal to or higher than the crystallization temperature of the amorphous film substrate, and is preferably equal to or higher than 200° C., more preferably equal to or higher than 220° C., and even more preferably equal to or higher than 240° C. If the heating temperature of the stretched film is equal to or higher than the lower limit, the amorphous film substrate can be sufficiently crystallized. On the other hand, from the viewpoint of preventing the film substrate from melting, the heating temperature of the stretched film is preferably equal to or lower than 300° C.

Since it is easily crystallized when heated at 200° C. or higher, the amorphous film substrate is preferably an amorphous polyethylene terephthalate film.
When heated to 200° C. or higher, at least a portion of the amorphous polyethylene terephthalate constituting the film substrate begins to melt. After melting, when cooled to a temperature lower than the crystallization temperature of polyethylene terephthalate, a portion of the molten amorphous polyethylene terephthalate crystallizes and solidifies. This allows the film substrate to become a crystalline polyethylene terephthalate film. The film substrate made of a crystalline polyethylene terephthalate film has excellent mechanical properties such as tensile strength.

The cooling method after heating is not particularly limited, and may be either blowing air at room temperature or allowing it to cool. Since the amorphous film substrate is prone to crystallization, it is preferable to cool the substrate at a slow temperature drop rate, specifically, at 200° C./min or less.
Through the above steps, a conductive film is obtained that has been subjected to the stretching step and the crystallization step.

(Production Example 1) Production 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 an oxidizing agent solution of ammonium persulfate previously dissolved in 10 ml of water was added dropwise over 20 minutes, and the solution was stirred for 12 hours.
1000ml of sulfuric acid diluted to 10% by mass was added to the obtained sodium polystyrene sulfonate-containing solution, and about 1000ml of the solvent was removed from the obtained polystyrene sulfonic acid-containing solution by ultrafiltration. Next, 2000ml of ion-exchanged water was added to the remaining liquid, and about 2000ml of the solvent was removed by ultrafiltration to wash the polystyrene sulfonic acid 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 PEDOT-PSS A solution obtained by dissolving 0.5 g of 3,4-ethylenedioxythiophene and 1.5 g of polystyrene sulfonic acid in 15.0 g of ion-exchanged water was mixed at 20° C. Next, 89.5 g of ion-exchanged water was added.
The resulting mixed solution was kept at 20° C., and while stirring, a solution of 0.03 g of ferric sulfate dissolved in 4.97 g of ion-exchanged water and a solution of 1.1 g of ammonium persulfate dissolved in 8.9 g of ion-exchanged water were slowly added, and the resulting reaction solution was stirred for 24 hours to cause a reaction.
By the above reaction, a conductive polymer dispersion liquid containing a conductive complex (PEDOT-PSS) containing poly(3,4-ethylenedioxythiophene) and polystyrenesulfonic acid, which are π-conjugated conductive polymers, and water, which is a dispersion medium, was obtained.
To this conductive polymer dispersion, 13.2 g of Duolite C255LFH (a cation exchange resin manufactured by Sumika Chemtex Co., Ltd.) and 13.2 g of Duolite A368S (anion exchange resin manufactured by Sumika Chemtex Co., Ltd.) were added, and the ion exchange resin was removed by filtration to obtain a conductive polymer dispersion from which the oxidizing agent and the catalyst had been removed. The solid content (non-volatile components) of the obtained conductive polymer dispersion was 1.3 mass%.

[Example 1]
30 g of the PEDOT-PSS aqueous dispersion obtained in Production Example 2 was mixed with 59.7 g of water, 10 g of PVA-217 (polyvinyl alcohol, manufactured by Kuraray Co., Ltd., 10 mass% aqueous solution, saponification degree 87% to 89%, polymerization degree 1700), and 0.3 g of 2-butyne-1,4-diol to obtain a conductive polymer dispersion.
The obtained conductive polymer dispersion was applied onto an amorphous polyethylene terephthalate film using a No. 8 bar coater to obtain a coated film. The obtained coated film was stretched 4 times at 100°C using a biaxial stretching device (Imoto Manufacturing Co., Ltd., 11A9) to obtain a stretched film. The stretched film was heated at 240°C for 30 seconds, and then slowly cooled so that the temperature drop rate was 100°C/min or less. This crystallized the amorphous polyethylene terephthalate film to obtain a conductive film having a conductive layer on the surface of the crystalline polyethylene terephthalate film.
The surface resistance of the obtained conductive film was measured, and then an abrasion resistance test was performed in which the nonwoven fabric was rubbed back and forth 10 times under a load of 100 g/ ^cm2 , and the appearance was observed. The results are shown in Table 1.

[Example 2]
A conductive film was obtained and measured in the same manner as in Example 1, except that the amount of 2-butyne-1,4-diol mixed was changed to 0.45 g and the amount of water mixed was changed to 59.55 g in Example 1. The results are shown in Table 1.

[Example 3]
A conductive film was obtained and measured in the same manner as in Example 1, except that the amount of 2-butyne-1,4-diol mixed was changed to 0.15 g and the amount of water mixed was changed to 59.85 g in Example 1. The results are shown in Table 1.

[Example 4]
A conductive film was obtained and measured in the same manner as in Example 1, except that the amount of PVA-217 mixed was changed to 15 g and the amount of water mixed was changed to 54.7 g in Example 1. The results are shown in Table 1.

[Example 5]
A conductive film was obtained and measured in the same manner as in Example 1, except that the amount of PVA-217 mixed was changed to 7.5 g and the amount of water mixed was changed to 62.2 g in Example 1. The results are shown in Table 1.

[Example 6]
A conductive film was obtained and measured in the same manner as in Example 1, except that 0.3 g of 2-butyne-1,4-diol was changed to 0.3 g of cis-2-butene-1,4-diol in Example 1. The results are shown in Table 1.

[Example 7]
A conductive film was obtained and measured in the same manner as in Example 1, except that 0.3 g of 2-butyne-1,4-diol was changed to 0.3 g of trans-2-butene-1,4-diol in Example 1. The results are shown in Table 1.

[Example 8]
A conductive film was obtained and measured in the same manner as in Example 1, except that 0.3 g of 2-butyne-1,4-diol was changed to 0.3 g of 2,4-hexadiyne-1,6-diol in Example 1. The results are shown in Table 1.

[Example 9]
A conductive film was obtained and measured in the same manner as in Example 1, except that 10 g of PVA-217 in Example 1 was changed to 10 g of PVA-210 (polyvinyl alcohol, manufactured by Kuraray Co., Ltd., 10% by mass aqueous solution, saponification degree 87% to 89%, polymerization degree 1000). The results are shown in Table 1.

[Example 10]
A conductive film was obtained and measured in the same manner as in Example 1, except that 10 g of PVA-224 (polyvinyl alcohol, manufactured by Kuraray Co., Ltd., 10% by mass aqueous solution, saponification degree 87% to 89%, polymerization degree 2400) was used instead of 10 g of PVA-217. The results are shown in Table 1.

[Example 11]
A conductive film was obtained and measured in the same manner as in Example 1, except that 0.3 g of thiodipropionic acid was further added and the amount of water was changed to 59.4 g. The results are shown in Table 1.

[Example 12]
A conductive film was obtained and measured in the same manner as in Example 1, except that 0.3 g of tris(2-carboxyethyl) isocyanurate was further added and the amount of water was changed to 59.4 g. The results are shown in Table 1.

[Comparative Example 1]
A conductive film was obtained and measured in the same manner as in Example 1, except that 2-butyne-1,4-diol was not added and the amount of water was changed to 60 g. The results are shown in Table 1.

[Comparative Example 2]
A conductive film was obtained and measured in the same manner as in Example 1, except that PVA-217 was not added and the amount of water was changed to 69.7 g. The results are shown in Table 1.

[Comparative Example 3]
A conductive film was obtained and measured in the same manner as in Example 1, except that 0.3 g of 2-butyne-1,4-diol was changed to 0.3 g of ethylene glycol. The results are shown in Table 1.

[Comparative Example 4]
A conductive film was obtained and measured in the same manner as in Example 1, except that 0.3 g of 2-butyne-1,4-diol was changed to 0.3 g of 1,4-butanediol. The results are shown in Table 1.

(Surface resistance value)
The surface resistance value (unit: Ω/□) of the conductive layer was measured using a resistivity meter (Loresta, manufactured by Nitto Seiko Analytech Co., Ltd.) at an applied voltage of 10 V. The results are shown in Table 1.
In the table, "2.0E+06" represents "2.0×10 ⁶ ", and the same applies to the others.

The conductive films of the Examples containing an unsaturated aliphatic alcohol compound were superior in conductivity and abrasion resistance to those of Comparative Examples 1 to 4 not containing an unsaturated aliphatic alcohol compound. The abrasion resistance of Examples 11 and 12, which further contained a polyvalent carboxylic acid compound in addition to the unsaturated aliphatic alcohol compound, was even more excellent. Example 8 is a reference example.
On the other hand, the conductive film of Comparative Example 2, which did not contain PVA, had fine cracks in the conductive layer during stretching, and lost conductivity. The conductive films of Comparative Examples 3 and 4, which did not contain an unsaturated aliphatic alcohol compound but contained a diol compound having no unsaturated bond, had poor conductivity and poor abrasion resistance.
From the above, it is clear that the conductive film according to the present invention has excellent conductivity and abrasion resistance.

Claims (8)

A conductive polymer dispersion liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, an unsaturated aliphatic alcohol compound which is a diol compound having 4 to 6 carbon atoms and which has one double bond or triple bond between carbon atoms in the molecule, a dispersion medium, and polyvinyl alcohol. 2. The conductive polymer dispersion according to claim 1, wherein the unsaturated aliphatic alcohol compound comprises at least one selected from the group consisting of cis-2-butene-1,4-diol, trans-2-butene-1,4-diol, and 2-butyne-1,4-diol. 3. The conductive polymer dispersion according to claim 1 , wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene), or the polyanion is polystyrenesulfonic acid. The conductive polymer dispersion according to any one of claims 1 to 3 , further comprising one or more polyvalent carboxylic acid compounds. 5. The conductive polymer dispersion according to claim 4 , wherein the polycarboxylic acid compound includes thiodipropionic acid or tris(2-carboxyethyl) isocyanurate. A method for producing a conductive laminate, comprising: applying the conductive polymer dispersion according to any one of claims 1 to 5 to at least a part of a surface of a substrate. the substrate is an amorphous film substrate, and the conductive polymer dispersion is applied to at least a portion of the surface of the amorphous film substrate to obtain a coated film;
The method for producing a conductive laminate according to claim 6 , further comprising: heating and stretching the coated film to obtain a stretched film. A conductive laminate comprising a substrate and a conductive layer formed on at least a portion of the surface of the substrate, the conductive layer being a cured layer of the conductive polymer dispersion according to any one of claims 1 to 5 .