JP7580338B2 - Conductive polymer dispersion and method for producing same, and method for producing conductive laminate - Google Patents

Description

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

Stretchability may be required for a conductive layer containing a π-conjugated conductive polymer. For example, when a carrier tape with a recess (storage section) for storing electronic components is formed by vacuum molding a conductive film with a conductive layer formed on the surface in a mold, the conductive film constituting the storage section is stretched about 2 to 4 times. At this time, there is a problem that fine cracks are generated in the conductive layer, reducing the conductivity (antistatic properties). To address this problem, Patent Document 1 discloses a technology that improves the stretchability of the conductive layer by incorporating polyvinyl alcohol (PVA) or the like into the conductive layer.

JP 2017-043765 A

If the stretched conductive layer retains sufficient conductivity even after it subsequently shrinks back to its original length, the conductive layer can be said to have elasticity. For example, a conductive laminate in which a stretchable conductive layer is formed on a substrate made of a stretchable material such as elastomer or polyurethane is expected to find a wide range of applications.

The present invention has been made in consideration of the above circumstances, and provides a conductive polymer dispersion capable of forming a conductive layer having elasticity, a method for producing the same, and a method for producing a conductive laminate.

[1] A conductive polymer dispersion comprising: a conductive complex containing a π-conjugated conductive polymer and a polyanion; water; an organic solvent; an amine compound other than imidazole; and a hydrophilic resin having an elongation at break of 500% or more as measured in accordance with JIS K6251.
[2] The conductive polymer dispersion according to [1], wherein the hydrophilic resin is contained in an amount of 100 parts by mass or more and 2000 parts by mass or less relative to 100 parts by mass of the conductive composite.
[3] The conductive polymer dispersion according to [1] or [2], wherein the hydrophilic resin contains a urethane resin or a versatic acid vinyl ester resin.
[4] The conductive polymer dispersion liquid according to any one of [1] to [3], wherein the amine compound includes an alkanolamine.
[5] The conductive polymer dispersion liquid according to [4], wherein the alkanolamine has an -NH ₂ group.
[6] The conductive polymer dispersion according to any one of [1] to [5], wherein the amine compound is contained in an amount of 1 part by mass or more and 100 parts by mass or less relative to 100 parts by mass of the conductive composite.
[7] The conductive polymer dispersion according to any one of [1] to [6], wherein a content of the water relative to a total mass of the conductive polymer dispersion is 30 mass% or more, or a content of the organic solvent relative to a total mass of the conductive polymer dispersion is 50 mass% or less.
[8] The conductive polymer dispersion according to any one of [1] to [7], wherein the π-conjugated conductive polymer contains poly(3,4-ethylenedioxythiophene) or the polyanion contains polystyrenesulfonic acid.
[9] A method for producing a conductive polymer dispersion, comprising adding a hydrophilic resin having an elongation at break of 500% or more, as measured in accordance with JIS K6251, to a mixed liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, water, an organic solvent, and an amine compound other than imidazole, to obtain a conductive polymer dispersion.
[10] A method for producing a conductive laminate, comprising the steps of: applying the conductive polymer dispersion according to any one of [1] to [8] to at least a part of a surface of a substrate to form a coating film; and drying the coating film to form a conductive layer.

According to the conductive polymer dispersion of the present invention, a conductive layer having excellent stretchability can be formed even without containing PVA. Furthermore, the conductive layer has excellent elasticity.
According to the method for producing a conductive polymer dispersion of the present invention, the above-mentioned conductive polymer dispersion can be easily produced.
The conductive layer of the conductive laminate of the present invention has excellent conductivity even after stretching, and also has excellent conductivity when it is subsequently shrunk to return to its original length.

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>>
The first aspect of the present invention is a conductive composite including a π-conjugated conductive polymer and a polyanion, water, an organic solvent, an amine compound other than imidazole, and a break time measured in accordance with JIS K6251. and a hydrophilic resin having an elongation rate of 500% or more.

<π-conjugated conductive polymer>
The π-conjugated conductive polymer is not particularly limited as long as it has the effect of the present invention and is 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 the above π-conjugated conductive polymers, poly(3,4-ethylenedioxythiophene) is particularly preferred from the viewpoints of 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 having an anionic group in the molecule. The monomer units may be of one type or of two or more types. The anionic group of the polyanion functions as a dopant for the π-conjugated conductive polymer, 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 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 (for example, 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.
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 conductive complex may contain one type of polyanion or two or more types of polyanions.
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 the average molecular weight based on mass measured by gel permeation chromatography and calculated in terms of polystyrene.

A conductive complex is formed by doping a polyanion into a π-conjugated conductive polymer. However, in the polyanion, some anion groups are not doped into the π-conjugated conductive polymer, and there are excess anion groups that are not involved in the doping. Since these excess anion groups are hydrophilic groups, the conductive complex has high water dispersibility and low organic solvent dispersibility.
When the number of all anionic groups in the polyanion is taken as 100 mol %, the excess anionic groups are preferably from 30 mol % to 90 mol %, more preferably from 45 mol % to 75 mol %.

The content of polyanion in the conductive complex is preferably in the range of 1 to 1000 parts by mass, more preferably 10 to 700 parts by mass, and even more preferably 100 to 500 parts by mass, per 100 parts by mass of the π-conjugated conductive polymer. If the content of polyanion is equal to or greater than the lower limit, the doping effect on the π-conjugated conductive polymer tends to be stronger, resulting in higher conductivity. On the other hand, if the content of polyanion is equal to or less than the upper limit, the amount of anion groups not involved in doping is appropriately suppressed.

The content of the conductive complex relative to the total mass of the conductive polymer dispersion is, for example, preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.2% by mass or more and 10% by mass or less, and even more preferably 0.3% by mass or more and 5.0% by mass or less.

<Dispersion medium>
The dispersion medium of the conductive polymer dispersion of this embodiment contains water and an organic solvent.
The organic solvent may be a water-soluble organic solvent or a water-insoluble organic solvent. Here, the water-soluble organic solvent is an organic solvent that dissolves in an amount of 1 g or more in 100 g of distilled water at 20° C., and the water-insoluble organic solvent is an organic solvent that dissolves in an amount of less than 1 g in 100 g of distilled water at 20° C.
From the viewpoint of improving compatibility with water, the organic solvent contained in the dispersion medium is preferably a water-soluble organic solvent.

Examples of the water-soluble organic solvent include alcohol-based solvents, ether-based solvents, ketone-based solvents, and nitrogen atom-containing solvents.
Examples of alcohol-based solvents include methanol, ethanol, 1-propanol, 2-propanol (isopropanol), 2-methyl-2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, and allyl alcohol.
Examples of the ether solvent include diethyl ether, dimethyl ether, propylene glycol dialkyl ether, and diethylene glycol diethyl ether.
Examples of the nitrogen atom-containing solvent include N-methylpyrrolidone, dimethylacetamide, and dimethylformamide.
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.
When the conductive polymer dispersion liquid of this embodiment contains the water-soluble organic solvent, the type of the water-soluble organic solvent may be one type or two or more types.

Examples of the non-water-soluble organic solvent include hydrocarbon solvents, etc. Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents.
Examples of the aliphatic hydrocarbon solvent include hexane, cyclohexane, pentane, heptane, octane, nonane, decane, and dodecane.
Examples of aromatic hydrocarbon solvents include benzene, toluene, xylene, ethylbenzene, propylbenzene, and isopropylbenzene.
When the conductive polymer dispersion of this embodiment contains a water-insoluble organic solvent, the type of the water-insoluble organic solvent may be one type or two or more types.

From the viewpoint of enhancing the dispersibility of the conductive composite in the conductive polymer dispersion of this embodiment and enhancing the compatibility of the entire dispersion, the content of water relative to the total mass of the conductive polymer dispersion of this embodiment is preferably 30 mass % or more, more preferably 40 mass % or more and 85 mass % or less, even more preferably 50 mass % or more and 80 mass % or less, and most preferably 60 mass % or more and 70 mass % or less.
From the same viewpoint as above, the content of the above-mentioned organic solvent relative to the total mass of the conductive polymer dispersion of this embodiment is preferably 50 mass% or less, more preferably 10 mass% or more and 45 mass% or less, even more preferably 15 mass% or more and 40 mass% or less, and most preferably 20 mass% or more and 35 mass% or less.

(Amine Compound)
The amine compound contained in the conductive polymer dispersion of this embodiment is an amine compound other than imidazole, and preferably contains an amine compound having one or more hydroxyl groups in the molecule.
As the amine compound having one or more hydroxyl groups in the molecule, an alkanolamine is preferred, and an alkanolamine having an --NH ₂ group is more preferred.
The alkanolamine preferably has 1 to 10 carbon atoms, more preferably 2 to 8 carbon atoms, further preferably 3 to 6 carbon atoms, and most preferably 3 or 4 carbon atoms.
The alkanolamine preferably has 1 to 4 hydroxyl groups, more preferably 1 to 3 hydroxyl groups, and even more preferably 1 or 2 hydroxyl groups.
Also preferred are amine compounds represented by the following formula N:
(Formula N)... R ¹ -NH-R ²
[In the formula, R ¹ and R ² each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms, and any one to three of the hydrogen atoms constituting R ¹ and R ² may be substituted with a hydroxyl group.]
Specific examples of the above-mentioned preferable amine compounds include 1-amino-2-propanol, 2-amino-1,3-propanediol, 2-[(hydroxymethyl)amino]ethanol, 3-methylamino-1,2-propanediol, and 2-(methylamino)ethanol.
The above examples of the amine compound do not distinguish between stereoisomers, and the structure of any stereoisomer can be adopted.
The above-mentioned suitable amine compounds can improve the dispersibility and compatibility of the conductive complex and the hydrophilic resin contained in the conductive polymer dispersion of this embodiment.
The amine compound contained in the conductive polymer dispersion of this embodiment may be one type or two or more types.

The content of the amine compound contained in the conductive polymer dispersion of this embodiment is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 5 parts by mass or more and 40 parts by mass or less, and even more preferably 8 parts by mass or more and 25 parts by mass or less, relative to 100 parts by mass of the conductive composite.
When the content is within the above preferred range, the dispersibility and compatibility of the conductive complex and the hydrophilic resin contained in the conductive polymer dispersion of this embodiment can be further improved.

The pH of the conductive polymer dispersion of this embodiment is preferably 1-6, more preferably 2-6, and even more preferably 3-6.
The pH value is measured using a known calibrated pH meter.

(hydrophilic resin)
The hydrophilic resin contained in the conductive polymer dispersion of this embodiment is a hydrophilic resin other than the conductive composite, and a test piece prepared from the hydrophilic resin alone has an elongation at break (elongation at break) of 500% or more as measured in accordance with JIS K6251 (2010).
The test piece used in the measurement is a dumbbell-shaped No. 3 test piece (film with a thickness of 0.3 to 0.4 mm) prepared in accordance with "8. Collection and preparation of test pieces" of JIS K6250 (2006). A film made of a hydrophilic resin can be obtained by drying a coating of a hydrophilic resin dispersion dispersed in a suitable dispersion medium.
The hydrophilic resin has a higher elongation percentage than general-purpose hydrophilic resins, and can improve the stretchability of the conductive layer that contains this hydrophilic resin together with the conductive complex.

Conventionally, when a mixture containing a hydrophilic resin exhibiting such a high elongation at break together with a conductive polymer composite is stirred, there is a problem that the dispersibility of the resin component decreases or gelation occurs (see Comparative Example described later). However, in the conductive polymer dispersion of this embodiment, by containing a specific amine compound, the dispersibility and compatibility of the hydrophilic resin and the conductive composite can be improved, and the dispersibility of the resin component is enhanced (see Example described later).

The elongation at break of the hydrophilic resin is preferably from 500% to 2000%, more preferably from 700% to 1600%, and even more preferably from 900% to 1300%.
When the content is within the above preferred range, the dispersibility of the resin component can be further improved, and the stretchability of the conductive layer formed from the conductive polymer dispersion of this embodiment can be further improved. That is, the conductivity of the conductive layer after stretching can be sufficiently increased, and the conductive layer can exhibit sufficient conductivity even when it subsequently shrinks together with the substrate.

The hydrophilic resin having an elongation at break of 500% or more preferably contains a urethane resin having a urethane bond in the polymer chain, or a versatic acid vinyl ester resin having versatic acid vinyl ester in the monomer units constituting the polymer chain. These hydrophilic resins may be modified with other reactive compounds, or may be copolymers with other polymerizable monomers. These hydrophilic resins can be made into aqueous dispersions.

Examples of the urethane resin include those obtained by reacting (a) a polyol, (b) a polyisocyanate, and, if necessary, (c) a low-molecular-weight chain extender having two or more active hydrogen atoms to obtain an isocyanate-terminated prepolymer, and then subjecting the resulting prepolymer to a chain extension reaction with (d) a polyamine compound having two or more amino groups and/or imino groups.
The urethane resin can be produced by a known method, for example, by referring to the production methods disclosed in JP-A-2008-248174, WO-A-2009/081815, and the like.

An example of a commercially available urethane resin with an elongation at break of 500% or more is the Evaphanol series, a water-based urethane resin manufactured by Nicca Chemical Co., Ltd.

Versatic acid vinyl ester is a compound represented by the following chemical formula (1).
(1)... CH ₂ =CH-OC(=O)-C(-R ¹ )(-R ² )-CH ₃

In the formula, R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, and it is preferable that at least one of R ¹ and R ² is a branched alkyl group, and more preferably that both are branched alkyl groups. The total number of carbon atoms in ^{R 1} and R ² is preferably 4 to 7, and more preferably 4 to 6.

Examples of other monomers copolymerizable with the vinyl versatate include vinyl acetate, (meth)acrylic acid alkyl esters, (meth)acrylic acid, olefins, (meth)acrylamides, etc. In this specification, "(meth)acrylic" is a general term for acrylic and methacrylic.
The content of the Versatic acid vinyl ester monomer unit in the Versatic acid vinyl ester copolymer is preferably 20 to 80%, and more preferably 30 to 70%, when the number of all monomer units is taken as 100%.

Polymers and copolymers of vinyl esters of versatic acid can be obtained by known methods for producing polymers and copolymers of known vinyl compounds.

Commercially available polymers and copolymers of versatic acid vinyl ester with an elongation at break of 500% or more include, for example, the VANORA series, which is a versatic acid vinyl ester copolymer acrylic emulsion manufactured by Kusumoto Chemicals Co., Ltd.

The conductive polymer dispersion of this embodiment may contain one type of hydrophilic resin, or two or more types of hydrophilic resins.

The content of the hydrophilic resin contained in the conductive polymer dispersion of this embodiment is preferably 100 parts by mass or more and 2,000 parts by mass or less, more preferably 200 parts by mass or more and 1,000 parts by mass or less, and even more preferably 300 parts by mass or more and 500 parts by mass or less, relative to 100 parts by mass of the conductive composite.
When it is at least the lower limit of the above range, the stretchability of the conductive layer formed from the conductive polymer dispersion of this embodiment can be further improved.
When it is equal to or less than the upper limit of the above range, the dispersibility and compatibility of the conductive complex and the hydrophilic resin contained in the conductive polymer dispersion of this embodiment can be further improved.

(Other additives)
The conductive polymer dispersion of this embodiment may contain other additives.
The additive is not particularly limited as long as the effects of the present invention can be obtained, and examples of the additive that can be used include surfactants, inorganic conductive agents, antifoaming agents, coupling agents, antioxidants, ultraviolet absorbers, etc. However, the additive is a compound other than the above-mentioned π-conjugated conductive polymers, polyanions, amine compounds, and hydrophilic resins.
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 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 of this embodiment contains the above-mentioned additive, the content thereof is appropriately determined depending on the type of additive, but can be, for example, in the range of 0.001 parts by mass or more and 5 parts by mass or less relative to 100 parts by mass of the conductive composite.

<Method for producing conductive polymer dispersion>
A second aspect of the present invention is a method for producing a conductive polymer dispersion, which comprises adding a hydrophilic resin having an elongation at break of 500% or more, as measured in accordance with JIS K6251, to a mixed liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, water, an organic solvent, and an amine compound other than imidazole, thereby obtaining a conductive polymer dispersion.
According to the production method of this embodiment, the conductive polymer dispersion of the first embodiment can be produced.

The mixed liquid may be an aqueous conductive polymer dispersion, which is a dispersion in which an aqueous dispersion medium contains an electrically conductive complex containing a π-conjugated conductive polymer and a polyanion.
Here, the aqueous dispersion medium is a mixed solvent of water and an organic solvent. The organic solvent is preferably a water-soluble organic solvent. Examples of the water-soluble organic solvent include alcohol-based solvents, ketone-based solvents, and ester-based solvents. The aqueous dispersion medium may contain one type of water-soluble organic solvent or two or more types of water-soluble organic solvents.

The conductive polymer aqueous dispersion can be obtained, for example, by chemically oxidizing a monomer that forms a π-conjugated conductive polymer in an aqueous solution of a polyanion. Alternatively, a commercially available conductive polymer aqueous dispersion can be used.
A known catalyst may be used in the chemical oxidative polymerization. For example, a catalyst and an oxidizing agent may be used. 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 respective contents of the conductive complex, water, organic solvent, and amine compound contained in the mixed liquid are adjusted to the suitable contents described in the first embodiment.
After adding an appropriate amount of the hydrophilic resin to the mixed solution, the mixture is gently stirred from the viewpoint of increasing the compatibility between the hydrophilic resin and the conductive composite to obtain the desired conductive polymer dispersion. In order to increase the dispersibility of the conductive composite, it is preferable to subject the mixed solution to a dispersion treatment in advance using a high-pressure homogenizer or the like before adding the hydrophilic resin to the mixed solution.

<Conductive laminate>
A third aspect of the present invention is 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 made of a cured product 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 provided on at least a portion of the surface of the substrate is, for example, preferably 10 nm to 100 μm, more preferably 20 nm to 50 μm, and even more preferably 30 nm to 30 μm.
When the average thickness of the conductive layer is equal to or greater than the lower limit, the conductive layer can exhibit sufficiently high conductivity, and when the average thickness is equal to or less than the upper limit, the conductive layer can exhibit improved adhesion to the substrate and better elasticity.

[Substrate]
The substrate constituting the conductive laminate of this embodiment 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 the same type of resin as the binder resin, and among these, a polyester resin such as polyethylene terephthalate is preferred.

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 adhesiveness of the conductive layer formed from the conductive polymer solution.

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.

The substrate in this embodiment may be a substrate having elasticity. In this embodiment, the conductive layer provided on the substrate can follow the expansion and contraction of the substrate. Examples of substrates having elasticity include substrates made of elastic materials such as elastomers, polyurethanes, silicone rubbers, and nitrile rubbers.

(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 glass substrates, an alkali-free glass is preferred. Here, the alkali-free glass refers to a glass composition having an alkali component content of 0.1 mass% or less relative to the total mass of the glass composition.

The average thickness of the glass substrate is preferably 50 μm or more and 3000 μm or less, and more preferably 100 μm or more and 1000 μm or less. 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 fourth aspect of the present invention is a method for producing a conductive laminate, the method including the steps of applying the conductive polymer dispersion of the first aspect to at least a part of the surface of the substrate to form a coating film, and drying the coating film to form a conductive layer. The conductive laminate of the third 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 coating film made of the conductive polymer dispersion applied onto the substrate is dried to remove the dispersion medium, thereby obtaining a conductive laminate in which a conductive layer (conductive film) is formed by 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 heat drying is applied, 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.

<Action and effect>
The conductive polymer dispersion of the first embodiment contains a specific amine compound, which enhances the dispersibility of the conductive complex and the hydrophilic resin having an elongation at break of 500% or more, and allows them to be compatible with each other. As a result, the dispersibility of the conductive complex and the hydrophilic resin in the conductive layer formed using the conductive polymer dispersion of the first embodiment is also enhanced, resulting in good conductivity. In addition, since the elongation at break of the hydrophilic resin forming the conductive layer is high, cracks are unlikely to occur even when the conductive layer is stretched and further when it is shrunk after stretching, and a decrease in conductivity can be 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 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 styrene sulfonate-containing solution, and about 1000ml of the polystyrene sulfonic acid-containing solution was removed by ultrafiltration. 2000ml of ion-exchanged water was added to the remaining liquid, and about 2000ml of the solution was removed by ultrafiltration. The above ultrafiltration operation was repeated three times. Furthermore, about 2000ml of ion-exchanged water was added to the obtained polystyrene sulfonic acid solution, and about 2000ml of the solution was removed by ultrafiltration. This ultrafiltration 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 14.2 g of 3,4-ethylenedioxythiophene and a solution in which 36.7 g of polystyrene sulfonic acid was dissolved in 2000 ml of ion-exchanged water were mixed at 20°C.
The resulting mixed solution was kept at 20° C., and while stirring, 29.64 g of ammonium persulfate and 8.0 g of an oxidation catalyst solution of ferric sulfate dissolved in 200 ml of ion-exchanged water were slowly added, and the mixture was reacted with stirring for 3 hours.
To the reaction solution obtained, 2000 ml of ion-exchanged water was added, and about 2000 ml of the solution 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, about 2000 ml of the solution was removed by ultrafiltration, 2000 ml of ion-exchanged water was added to the solution, and about 2000 ml of the solution 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 solution was removed by ultrafiltration. This operation was repeated five times to obtain a 1.2 mass% polystyrenesulfonic acid-doped poly(3,4-ethylenedioxythiophene) (PEDOT-PSS aqueous dispersion) solution. The content of PSS relative to the PEDOT-PSS solid content was 75 mass%.

Example 1
0.1 g of 1-amino-2-propanol and 20 g of ion-exchanged water were added to 40 g of the PEDOT-PSS aqueous dispersion obtained in Production Example 2 (containing 0.48 g of PEDOT-PSS), and the mixture was stirred at room temperature for 10 minutes. Then, 30 g of methanol was added and the mixture was stirred at room temperature for 10 minutes, after which 6.6 g of Evaphanol HA-15 (manufactured by NICCA Chemical Co., Ltd., hydrophilic polyurethane resin, solid content concentration 30 mass%, elongation at break 1100%) was added and the mixture was stirred at room temperature for 10 minutes, thereby obtaining a conductive polymer dispersion. The pH of the conductive polymer dispersion measured with a calibrated pH meter was 7.9.
The obtained conductive polymer dispersion was applied to a polyethylene terephthalate film (Lumirror T60, manufactured by Toray Industries, Inc.) using a No. 12 bar coater, and dried at 120° C. for 2 minutes to obtain a conductive film.
The elongation at break is a value measured by the method described above.

Example 2
A conductive glass having a conductive layer was obtained in the same manner as in Example 1, except that the conductive polymer dispersion was applied to a glass plate instead of a polyethylene terephthalate film.

Example 3
A conductive film was obtained in the same manner as in Example 1, except that 2-amino-1,3-propanediol was added instead of 1-amino-2-propanol.
The pH of the applied conductive polymer dispersion was 8.2.

Example 4
A conductive glass having a conductive layer was obtained in the same manner as in Example 3, except that the conductive polymer dispersion was applied to a glass plate instead of a polyethylene terephthalate film.

Example 5
A conductive film was obtained in the same manner as in Example 1, except that the amount of 1-amino-2-propanol added was changed to 0.05 g.
The pH of the applied conductive polymer dispersion was 4.0.

Example 6
A conductive film was obtained in the same manner as in Example 1, except that a spray was used instead of the bar coater, and the conductive polymer dispersion was applied to a polyurethane film instead of a polyethylene terephthalate film.
Here, the polyurethane film used was a commercially available urethane sheet having a hardness of A60 (thickness 1 mm, elongation at break 740%).

(Example 7)
A conductive film was obtained in the same manner as in Example 3, except that a spray was used instead of a bar coater, and the conductive polymer dispersion was applied to the polyurethane film instead of the polyethylene terephthalate film.

(Example 8)
A conductive film was obtained in the same manner as in Example 5, except that a spray was used instead of a bar coater, and the conductive polymer dispersion was applied to the polyurethane film instead of the polyethylene terephthalate film.

Example 9
A conductive film was obtained in the same manner as in Example 6, except that 4 g of VANORA DXV.4051 (manufactured by Kusumoto Chemicals Co., Ltd., solid content concentration 50 mass%, versatate vinyl ester-acrylic copolymer emulsion, elongation at break 500%) was added instead of Evaphanol HA-15. The pH of the applied conductive polymer dispersion was 8.2.
The elongation at break is a value measured by the method described above.

(Example 10)
A conductive film was obtained in the same manner as in Example 6, except that 4.4 g of VANORA DXV.4176 (manufactured by Kusumoto Chemicals Co., Ltd., solid content concentration 45 mass%, versatic acid vinyl ester polymer, elongation at break 900%) was added instead of Evaphanol HA-15. The pH of the applied conductive polymer dispersion was 8.0.
The elongation at break is a value measured by the method described above.

(Comparative Example 1)
A conductive film was obtained in the same manner as in Example 5, except that 10 g of PLASCOAT RZ-105 (manufactured by GOO Chemical Co., Ltd., solid content concentration 25 mass%, water-dispersible polyester resin, elongation at break less than 500%) was added instead of Evaphanol HA-15.
The pH of the applied conductive polymer dispersion was 8.0.
The elongation at break is a value measured by the method described above.

(Comparative Example 2)
An attempt was made to prepare a conductive polymer dispersion in the same manner as in Example 1, except that imidazole was added instead of 1-amino-2-propanol. However, the conductive polymer dispersion gelled, making it difficult to apply, and a conductive film could not be obtained.
The pH of the resulting gel was checked with a pH test paper and found to be about 8.

<Measurement of surface resistance>
For the conductive film or conductive glass obtained in each example, the surface resistance value of the conductive layer was measured using a resistivity meter (Hiresta manufactured by Nitto Seiko Analytech Co., Ltd.) under the condition of an applied voltage of 10 V. The measured values are shown in Table 1.

<Stretching and shrinkage (expansion and contraction) of conductive film>
The conductive films obtained in Examples 6 to 9 and Comparative Example 1 were cut into rectangular specimens measuring several centimeters in length and width. The two vertical sides of the specimen were held and slowly stretched in the horizontal direction (approximately 1 cm/sec) until the horizontal length was three times larger, and the stretched state was maintained, and the surface resistance value of the conductive layer was measured. The specimen was then slowly shrunk using the contraction force of the substrate, and the specimen naturally shrunk to its original size. The surface resistance value of the conductive layer that had shrunk following this was measured. These measured values are shown in Table 1.

The conductive polymer dispersions of the examples containing a specific amine compound and a specific hydrophilic resin had excellent dispersibility and compatibility of the resin components, and therefore were able to form conductive layers with excellent conductivity.
The conductive layer of the conductive film of each Example had excellent elasticity and showed good conductivity even in the stretched state and in the contracted state after release of stretching. On the other hand, the conductive layer of the conductive film of Comparative Example 1 had poor elasticity and cracks occurred due to stretching. As a result, the surface resistance value showed a value (OVER) that was so high that it could not be measured. Naturally, even after the stretched state was released and the film was shrunk, the cracks in the conductive layer did not repair, and the surface resistance value was so high that it could not be measured.

Claims (9)

A conductive polymer dispersion comprising: a conductive complex containing a π-conjugated conductive polymer and a polyanion; water; an organic solvent; an alkanolamine ; and a hydrophilic resin having an elongation at break of 500% or more as measured in accordance with JIS K6251. The conductive polymer dispersion according to claim 1, wherein the hydrophilic resin is contained in an amount of 100 parts by mass or more and 2000 parts by mass or less per 100 parts by mass of the conductive composite. The conductive polymer dispersion according to claim 1 or 2, wherein the hydrophilic resin comprises a urethane resin or a versatic acid vinyl ester resin. The conductive polymer dispersion according to claim 3 , wherein the alkanolamine has an —NH ₂ group. The conductive polymer dispersion according to any one of claims 1 to 4 , wherein the alkanolamine is contained in an amount of 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the conductive complex. 6. The conductive polymer dispersion according to claim 1 , wherein a content of the water relative to a total mass of the conductive polymer dispersion is 30 mass% or more, or a content of the organic solvent relative to a total mass of the conductive polymer dispersion is 50 mass % or less. The conductive polymer dispersion according to any one of claims 1 to 6 , wherein the π-conjugated conductive polymer contains poly(3,4-ethylenedioxythiophene), or the polyanion contains polystyrenesulfonic acid. A method for producing a conductive polymer dispersion, comprising adding a hydrophilic resin having an elongation at break of 500% or more, as measured in accordance with JIS K6251, to a mixed liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, water, an organic solvent, and an alkanolamine, thereby obtaining a conductive polymer dispersion. A method for producing a conductive laminate, comprising: a step of applying the conductive polymer dispersion according to any one of claims 1 to 7 to at least a part of a surface of a substrate to form a coating film; and a step of drying the coating film to form a conductive layer.