JP7792869B2 - Conductive polymer dispersion, conductive laminate and method for producing the same - Google Patents

Description

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

One technique for manufacturing electronic devices is to form a conductive layer on the surface of a resin substrate. π-conjugated conductive polymers have attracted attention as materials for forming conductive layers due to their excellent conductivity and transparency. Furthermore, a release layer containing silicone may be further laminated on the surface of the conductive layer. Such a conductive release film is disclosed in Patent Document 1.

Japanese Patent Application Laid-Open No. 2020-204009

The conductive polymer dispersion in Patent Document 1 contains a polyolefin resin, which provides particularly excellent adhesion to polyolefin substrates. Polyolefins have excellent processability, making them suitable for a wide range of applications. If a silicone-containing release layer is further laminated on the surface of the conductive layer, the surface can be made easily peelable (releasable). However, this increases the number of steps required to laminate the release layer on the surface of the conductive layer.

The present invention provides a conductive laminate having a conductive release layer that combines conductivity and releasability, a method for producing the same, and a conductive polymer dispersion suitable for the production method.

[1] A conductive polymer dispersion containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, a silicone emulsion, a carboxy group-containing polyolefin resin, and an aqueous dispersion medium.
[2] The conductive polymer dispersion liquid according to [1], wherein the content of water contained in the aqueous dispersion medium is 40 parts by mass or more relative to 1 part by mass of the conductive composite.
[3] The conductive polymer dispersion liquid according to [1] or [2], wherein the aqueous dispersion medium contains a water-soluble organic solvent, and the content of the water-soluble organic solvent relative to the total mass of the aqueous dispersion medium is 50 mass % or more and 95 mass % or less.
[4] The conductive polymer dispersion liquid according to any one of [1] to [3], further containing a platinum-based catalyst.
[5] The conductive polymer dispersion according to any one of [1] to [4], further comprising a basic compound.
[6] The conductive polymer dispersion according to any one of [1] to [5], wherein the content of the basic compound relative to the total mass of the conductive polymer dispersion is 1 mM or more and 10 mM or less.
[7] The conductive polymer dispersion according to any one of [1] to [6], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene), or the polyanion is polystyrenesulfonic acid.
[8] A conductive laminate comprising a substrate and a conductive release layer formed on at least a part of the surface of the substrate, wherein the conductive release layer is a cured product of the conductive polymer dispersion according to any one of [1] to [7].
[9] The conductive laminate according to [8], wherein the substrate is a polypropylene film.
[10] 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 the surface of a substrate to form a conductive layer.

In the conductive laminate of the present invention, the conductive release layer exhibits excellent conductivity and releasability, and further, the conductive release layer has excellent adhesion to the substrate.
The manufacturing method of the present invention makes it possible to easily manufacture the above-mentioned excellent conductive laminate. The conductive polymer dispersion of the present invention is suitable for the above-mentioned manufacturing method and has excellent wettability to the substrate.

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 numerical ranges indicated with "~" are considered to be included in the numerical range.

≪Conductive polymer dispersion liquid≫
A first aspect of the present invention is a conductive polymer dispersion containing a conductive composite containing a π-conjugated conductive polymer and a polyanion, a silicone emulsion, a carboxy group-containing polyolefin resin, and an aqueous dispersion medium.

[Conductive composite]
The conductive composite contained in the conductive polymer dispersion of this embodiment contains a π-conjugated conductive polymer and a polyanion. The polyanion in the conductive composite dopes the π-conjugated conductive polymer to form a conductive composite having conductivity.
In polyanions, only some of the anionic groups are doped into the π-conjugated conductive polymer, and there are excess anionic groups that are not involved in the doping. Because 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, polyphenylene vinylene-based conductive polymers, polyaniline-based conductive polymers, polyacene-based conductive polymers, polythiophene vinylene-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-dodecyl 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, improving the conductivity of the π-conjugated conductive polymer.
The anionic 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 (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. The polyanion may be a homopolymer formed by polymerizing a single monomer, or a copolymer formed by polymerizing two or more monomers.
Among these polyanions, polymers having sulfo groups are preferred, and polystyrene sulfonic acid is more preferred, since they can further increase the conductivity.
The polyanions may be used alone or in combination of two or more.
The mass average molecular weight of the polyanion is preferably 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 on a mass basis measured using gel filtration chromatography and calculated as pullulan.

The content of polyanion in the conductive composite is preferably in the range of 1 to 1,000 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 above 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 below the upper limit, a sufficient amount of π-conjugated conductive polymer can be contained, ensuring sufficient conductivity.

The content of the conductive complex contained in the conductive polymer dispersion of this embodiment is preferably 0.01 mass % or more and 5.0 mass % or less, more preferably 0.10 mass % or more and 2 mass % or less, and even more preferably 0.15 mass % or more and 1.0 mass % or less, relative to the total mass of the conductive polymer dispersion.
When the content is at least as large as the lower limit of the above range, the conductivity of the conductive release layer formed by applying the conductive polymer dispersion can be further improved.
When the content 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 release layer can be formed.

[Silicone emulsion]
A silicone emulsion is an emulsion formed by dispersing a silicone compound in an aqueous dispersion medium. A surfactant (emulsifier) may also be included to form the emulsion of the silicone compound.
As the silicone-based compound, silicone-based compounds contained in known mold release agents can be used. Here, silicone refers to a polymer collectively called organopolysiloxane, which has a main chain (silicone skeleton) in which organic groups (e.g., alkyl groups, phenyl groups, etc.) are bonded to siloxane bonds. As the organopolysiloxane, polydimethylsiloxane (PDMS) is preferred, and polydimethylsiloxanes having reactive or non-reactive functional groups in part are also preferred. In addition, acrylic resins and alkyd resins having organopolysiloxane in their side chains can also be used as the silicone-based compound.

As the silicone compound, a curable silicone is preferred because it exhibits stable releasability and excellent film-forming properties.
The curable silicone may be either an addition curable silicone or a condensation curable silicone. When curable silicone reacts, it forms a three-dimensional crosslinked structure and cures.
Examples of addition-curable silicones include linear polymers having siloxane bonds, including polydimethylsiloxane having vinyl groups at both ends of the linear chain, and hydrogensilane. A platinum-based curing catalyst may be used to accelerate the curing.
Specific examples of addition-curable silicones include KM-3951, X-52-6068, X-52-151, and X-52-6069 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

The content of solids (non-volatile content) of the silicone emulsion relative to the total mass of the conductive polymer dispersion of this embodiment is preferably from 0.1% by mass to 4.0% by mass, more preferably from 0.5% by mass to 3.5% by mass, even more preferably from 1.0% by mass to 3.0% by mass, and most preferably from 1.5% by mass to 2.5% by mass.
When the content is at least as large as the lower limit of the above range, excellent releasability can be imparted to the conductive release layer.
When the content is equal to or less than the upper limit of the above range, the conductivity of the conductive release layer can be sufficiently maintained, and excellent adhesion of the conductive release layer to the substrate can be maintained.

[Curing agent]
The conductive polymer dispersion of this embodiment may contain a curing agent that accelerates the curing of the curable silicone. The curing agent is selected depending on the type of curable silicone used.
In the case of addition reaction type silicone, it is preferable to use a platinum catalyst as a curing agent.
Specific examples of platinum catalysts include CAT-PL-50T and CAT-PM-10A (manufactured by Shin-Etsu Chemical Co., Ltd.).
In the case of a condensation reaction type silicone resin, it is preferable to use an organotin catalyst (for example, an organotin acylate catalyst) as a curing agent. A specific example of the organotin catalyst is CAT-PS-8S (manufactured by Shin-Etsu Chemical Co., Ltd.).

[Carboxy group-containing polyolefin resin]
The carboxy group-containing polyolefin resin contained in the conductive polymer dispersion of this embodiment is a polyolefin resin having one or more carboxy groups, and is obtained by copolymerizing a polyolefin resin constituting the main chain with an unsaturated carboxylic acid monomer having a carboxy group. The number of carboxy groups in the carboxy group-containing polyolefin is preferably two or more, since this improves the adhesion of the conductive release layer to the plastic substrate.
Specifically, the carboxy group-containing polyolefin resin may be a graft copolymer in which an unsaturated carboxylic acid monomer is graft polymerized onto a polyolefin resin, or may be a random copolymer or block copolymer of an olefin monomer and an unsaturated carboxylic acid monomer.
The carboxyl group-containing polyolefin resin may be used alone or in combination of two or more kinds.

Examples of the olefin monomer constituting the polyolefin resin include unsaturated hydrocarbons having from 2 to 6 carbon atoms. Examples of unsaturated hydrocarbons having from 2 to 6 carbon atoms include ethylene, propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene, butadiene, and isoprene. One type of the unsaturated hydrocarbons may be used alone, or two or more types may be used in combination.
The olefin monomer constituting the polyolefin resin is preferably selected depending on the plastic substrate to which the conductive polymer dispersion of this embodiment is to be applied. For example, when a polypropylene substrate is used as the plastic substrate, it is preferable to use propylene as the olefin monomer constituting the polyolefin resin, and when a polyethylene substrate is used as the plastic substrate, it is preferable to use ethylene as the olefin monomer constituting the polyolefin resin.

The content of olefin monomer units in the carboxy group-containing polyolefin resin is preferably 60% by mass or more and 99.5% by mass or less, more preferably 80% by mass or more and 99.5% by mass or less, and even more preferably 90% by mass or more and 99.5% by mass or less. If the content of olefin monomer units in the carboxy group-containing polyolefin resin is within this range, the adhesion of the conductive release layer to the plastic substrate will be higher.

The unsaturated carboxylic acid monomer used in this embodiment is preferably a compound having one or more vinyl groups and one or more carboxy groups, and an acid anhydride thereof.Specific examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, and allyl succinic acid.The unsaturated carboxylic acid monomer may be used alone or in combination of two or more.
Among the unsaturated carboxylic acid monomers, maleic anhydride, acrylic acid, and methacrylic acid are preferred because they can be easily introduced into the polyolefin resin, and maleic anhydride is more preferred.

The content of the unsaturated carboxylic acid monomer unit in the carboxyl group-containing polyolefin resin is preferably 0.5% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less. If the content of the unsaturated carboxylic acid monomer unit in the carboxyl group-containing polyolefin resin is equal to or more than the lower limit, the adhesion of the conductive release layer to the plastic substrate is improved, and if it is equal to or less than the upper limit, the carboxyl group-containing polyolefin resin can be easily produced.
The carboxylic acid value of the carboxyl group-containing polyolefin resin is preferably in the range of 5 mgKOH/g to 500 mgKOH/g, more preferably in the range of 10 mgKOH/g to 100 mgKOH/g. If the carboxylic acid value of the carboxyl group-containing polyolefin resin is equal to or greater than the lower limit, the adhesion of the conductive release layer to the plastic substrate is improved, and if it is equal to or less than the upper limit, the carboxyl group-containing polyolefin resin can be easily produced.

The carboxy group-containing polyolefin resin may have other monomer units in addition to the unsaturated hydrocarbon units and the unsaturated carboxylic acid monomer units.
Examples of the other monomers include alkyl acrylates (e.g., methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc.), alkyl methacrylates (e.g., methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc.), hydroxyalkyl acrylates (e.g., 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, etc.), hydroxyalkyl methacrylates (e.g., 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, etc.), unsaturated hydrocarbons having 7 or more carbon atoms (e.g., 1-octene, etc.), vinyl esters (e.g., vinyl acetate, etc.), vinyl cyanides (e.g., acrylonitrile, etc.), aromatic vinyls (e.g., styrene, etc.), etc. One type of the other monomers may be used alone, or two or more types may be used in combination.
However, the content of the other monomer units in the carboxyl group-containing polyolefin resin is preferably 20% by mass or less.

The method for producing the carboxyl group-containing polyolefin resin is not particularly limited, and known polymerization methods can be applied.
For example, when the carboxyl group-containing polyolefin resin is a graft copolymer obtained by graft polymerizing an unsaturated carboxylic acid monomer onto a polyolefin resin, a method of reacting the unsaturated carboxylic acid monomer with the polyolefin resin in the presence of a radical polymerization initiator can be mentioned. During the reaction, the polyolefin resin may be dissolved or dispersed in an organic solvent, or the polyolefin resin may be heated and melted without using an organic solvent.
Examples of the radical polymerization initiator include organic peroxides such as di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, tert-butylcumyl peroxide, benzoyl peroxide, dilauryl peroxide, cumene hydroperoxide, tert-butyl peroxybenzoate, ethyl ethyl ketone peroxide, and di-tert-butyl diperphthalate; and azo compounds such as azobisisobutyronitrile.

The mass average molecular weight of the carboxy group-containing polyolefin resin is preferably from 20,000 to 150,000, more preferably from 30,000 to 120,000, even more preferably from 30,000 to 100,000, and particularly preferably from 30,000 to 90,000. The mass average molecular weight of the carboxy group-containing polyolefin resin is a molecular weight based on mass determined by measuring the elution time using gel permeation chromatography (GPC) and based on a calibration curve of elution time versus molecular weight obtained in advance from polystyrene standard substances of known molecular weight.
If the mass average molecular weight of the carboxy group-containing polyolefin resin is equal to or greater than the lower limit of the above range, the adhesion of the conductive release layer to the plastic substrate can be further improved, and if it is equal to or less than the upper limit of the above range, the dispersibility of the carboxy group-containing polyolefin resin in the conductive polymer dispersion can be improved.

The carboxylic acid contained in the carboxyl group-containing polyolefin resin may be neutralized. If the carboxyl group-containing polyolefin resin is neutralized, the dispersibility of the carboxyl group-containing polyolefin resin in the conductive polymer dispersion can be improved.
The carboxyl group-containing polyolefin resin can be neutralized by adding an alkaline compound.
The alkaline compound may be either an inorganic alkali or an organic alkali.
Examples of inorganic alkaline compounds include sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium hydrogen carbonate, potassium hydrogen carbonate, and ammonium hydrogen carbonate.
The organic alkali includes primary amines, secondary amines, tertiary amines, quaternary ammonium salts, and nitrogen-containing aromatic cyclic compounds.
Examples of primary amines include aniline, toluidine, benzylamine, and ethanolamine.
Examples of secondary amines include diethanolamine, dimethylamine, diethylamine, dipropylamine, diphenylamine, dibenzylamine, and dinaphthylamine.
Examples of tertiary amines include triethanolamine, trimethylamine, triethylamine, tripropylamine, triphenylamine, tribenzylamine, and trinaphthylamine.
Examples of quaternary ammonium salts include tetramethylammonium salts, tetraethylammonium salts, tetrapropylammonium salts, tetraphenylammonium salts, tetrabenzylammonium salts, tetranaphthylammonium salts, etc. Examples of anions that serve as a counter ion to ammonium include hydroxide ions.
Examples of nitrogen-containing aromatic cyclic compounds include aniline, benzylamine, pyrrole, imidazole, 2-methylimidazole, 2-propylimidazole, N-methylimidazole, 1-(2-hydroxyethyl)imidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-acetylimidazole, 2-aminobenzimidazole, 2-amino-1-methylbenzimidazole, 2-hydroxybenzimidazole, 2-(2-pyridyl)benzimidazole, and pyridine.
The alkali compounds may be used alone or in combination of two or more.

The amount of alkali compound added is preferably 0.3 to 3 equivalents relative to the carboxy groups of the carboxy group-containing polyolefin resin, more preferably 0.5 to 2 equivalents, and even more preferably 0.6 to 1.5 equivalents. If the amount of alkali compound added is above the lower limit, the dispersibility of the carboxy group-containing polyolefin resin can be further improved. If the amount is below the upper limit, the conductive polymer dispersion can be prevented from becoming excessively alkaline, which would result in a decrease in conductivity.

The content of the carboxy group-containing polyolefin resin in the conductive polymer dispersion is preferably 100 parts by mass or more and 10,000 parts by mass or less, more preferably 100 parts by mass or more and 5,000 parts by mass or less, and even more preferably 100 parts by mass or more and 1,000 parts by mass or less, per 100 parts by mass of the conductive composite. If the content of the carboxy group-containing polyolefin resin is equal to or greater than the lower limit, the adhesion of the conductive release layer to the plastic substrate can be further improved. If the content is equal to or less than the upper limit, a decrease in conductivity due to a decrease in the content of the conductive composite can be prevented.

Furthermore, the content of the carboxy group-containing polyolefin resin in the conductive polymer dispersion is preferably 10 parts by mass or more and 1,000 parts by mass or less, more preferably 30 parts by mass or more and 500 parts by mass or less, and even more preferably 50 parts by mass or more and 100 parts by mass or less, relative to 100 parts by mass of the solid content of the silicone emulsion.
When the content is in the above range, the adhesiveness and film strength of the conductive release layer can be increased without impairing the releasability provided by the silicone emulsion.

[Aqueous dispersion medium]
The aqueous dispersion medium contained in the conductive polymer dispersion of this embodiment is water or a mixture of water and an organic solvent.

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; and dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol.
Examples of the ether solvent include diethyl ether, dimethyl ether, and propylene glycol dialkyl ether.
Examples of ketone solvents 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.
An example of a solvent that does not fall into the above categories is dimethyl sulfoxide.
The organic solvents may be used alone or in combination of two or more.

The aqueous dispersion of this embodiment is preferably a mixed solvent of water and a water-soluble organic solvent, from the viewpoint of enhancing the dispersibility of the silicone emulsion and the carboxyl group-containing polyolefin resin.
Here, a water-soluble organic solvent is an organic solvent that dissolves in an amount of 1 g or more in 100 g of water at 20°C, and a water-insoluble organic solvent is an organic solvent that dissolves in an amount of less than 1 g in 100 g of water at 20°C.
The water-soluble organic solvent is preferably one or more selected from alcohol-based solvents.

Since the conductive composite has high dispersibility in water, from the viewpoint of enhancing the dispersibility of the conductive composite, the content ratio of water relative to the total mass of the aqueous dispersion medium is, for example, preferably 10% by mass or more and 50% by mass or less, more preferably 15% by mass or more and 40% by mass or less, and even more preferably 20% by mass or more and 30% by mass or less.
Furthermore, the content of water per 1 part by mass of the conductive composite is preferably 40 parts by mass or more, more preferably 50 parts by mass or more and 1,000 parts by mass or less, even more preferably 80 parts by mass or more and 800 parts by mass or less, and particularly preferably 100 parts by mass or more and 400 parts by mass or less.
As the dispersion medium other than water, the above-mentioned water-soluble organic solvents are preferred.

The content of the water-soluble organic solvent relative to the total mass of the aqueous dispersion medium in the conductive polymer dispersion of this embodiment is, for example, preferably 50% by mass or more and 95% by mass or less, more preferably 60% by mass or more and 90% by mass or less, and even more preferably 70% by mass or more and 85% by mass or less.

[Basic Compounds]
The conductive polymer dispersion of this embodiment may contain one or more basic compounds. By containing a basic compound, the wettability of the conductive polymer dispersion to the substrate can be improved. Examples of basic compounds include inorganic alkalis, amine compounds, and nitrogen-containing aromatic cyclic compounds.

Examples of inorganic alkalis include sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium bicarbonate, potassium bicarbonate, and ammonium bicarbonate.

The content of the basic compound contained in the conductive polymer dispersion of this embodiment is, for example, preferably 0.1 mM or more and 50 mM or less, more preferably 0.5 mM or more and 20 mM or less, and even more preferably 1 mM or more and 10 mM or less.
When the content is within the above range, the wettability of the conductive polymer dispersion to the substrate can be further improved.

[Other additives]
The conductive polymer dispersion may contain other additives.
The additives are not particularly limited as long as they can achieve the effects of the present invention, and examples thereof include surfactants, inorganic conductive agents, antifoaming agents, coupling agents, antioxidants, and ultraviolet absorbers.
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 inorganic conductive agents include metal ions, conductive carbon, etc. Metal ions can be generated by dissolving a metal salt in water.
Examples of the coupling agent include silane coupling agents 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 determined appropriately 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 manufacturing conductive polymer dispersion>
An example of a method for producing the conductive polymer dispersion of this embodiment is a method in which a silicone emulsion, a carboxy group-containing polyolefin resin, and, if necessary, a basic compound are added to an aqueous dispersion of a conductive complex.
The aqueous dispersion of the conductive complex may be obtained by chemically oxidatively polymerizing a monomer that forms a π-conjugated conductive polymer in an aqueous solution of polyanion by a known method, or a commercially available product may be used.

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

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

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

[Base material]
The substrate may be made of an insulating material or 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.
Examples of conductive materials include metals, conductive metal oxides, and carbon.

(Film substrate)
When a film substrate is used as the substrate, the conductive laminate becomes a conductive film.
Examples of the film substrate include plastic films made of synthetic resins, 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 elastomers, polyester-based elastomers, 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 release layer, the synthetic resin for the film substrate is preferably a polyolefin resin, and among these, polypropylene is preferred.

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

The average thickness of the film substrate is preferably 5 μm or more and 500 μm or less, and more preferably 20 μm or more and 200 μm or less. When the average thickness of the film substrate is equal to or more than the lower limit, the film is less likely to break, and when 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 locations 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 release layer tends to decrease, so alkali-free glass is preferred among the glass substrates. Here, 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 100 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 it 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, which comprises applying the conductive polymer dispersion of the first aspect to at least a part of the surface of a substrate to form a conductive release layer. By the production method of this aspect, the conductive laminate of the second aspect can be produced.

Examples of methods for coating (applying) the conductive polymer dispersion onto any surface of a substrate include 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 to be applied to the substrate is not particularly limited, but in consideration of uniform and even application, 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.

It is preferable to remove the dispersion medium by drying the coating film made of the conductive polymer dispersion applied to the substrate. Methods for drying the coating film include heat drying, vacuum drying, etc. Examples of heat drying methods 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.
By the above method, a conductive laminate having a conductive release layer (conductive film) formed thereon can be obtained by drying and curing the coating film.

(Production Example 1) Production of polystyrene sulfonic acid 206 g of sodium styrene sulfonate was dissolved in 1,000 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.
To the resulting sodium polystyrene sulfonate-containing solution, 1000 ml of sulfuric acid diluted to 10% by mass was added to obtain a polystyrene sulfonic acid-containing solution. Next, approximately 1000 ml of the solvent was removed from the polystyrene sulfonic acid-containing solution by ultrafiltration, and 2000 ml of ion-exchanged water was added to the remaining solution, and approximately 2000 ml 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) Preparation of PEDOT-PSS aqueous dispersion A solution prepared 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 being stirred, a solution prepared by dissolving 0.03 g of ferric sulfate in 4.97 g of ion-exchanged water and a solution prepared by dissolving 1.1 g of ammonium persulfate in 8.9 g of ion-exchanged water were slowly added, and the resulting reaction solution was stirred for 24 hours to react.
By the above reaction, a PEDOT-PSS aqueous dispersion was obtained, which contained 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.
To this dispersion, 13.2 g of Duolite C255LFH (a cation exchange resin manufactured by Sumika Chemtex Co., Ltd.) and 13.2 g of Duolite A368S (an anion exchange resin manufactured by Sumika Chemtex Co., Ltd.) were added, and the ion exchange resin was removed by filtration to obtain an aqueous dispersion of PEDOT-PSS (solid content: 1.3% by mass) from which the oxidant and the catalyst had been removed.

Example 1
A conductive polymer dispersion was prepared by mixing 100 g of the PEDOT-PSS aqueous dispersion obtained in Production Example 2, 40 g of KM-3951 (addition-curing silicone emulsion, solids content 30%, aqueous dispersion, manufactured by Shin-Etsu Chemical Co., Ltd.), 40 g of Arrowbase DC-1010J2 (carboxy group-containing polyolefin resin emulsion, solids content 26.5%, aqueous dispersion, manufactured by Unitika Ltd.), 4 g of CAT-PM-10A (platinum catalyst, aqueous dispersion, manufactured by Shin-Etsu Chemical Co., Ltd.), and 540 g of methanol.
Next, the mixture was applied to a polypropylene film using a #8 bar coater and dried at 120° C. for 1 minute to obtain a conductive film provided with a conductive release layer.
The surface resistance, peel strength, adhesion, and wettability (visual repellency) of the applied conductive polymer dispersion to the polypropylene film of the obtained conductive film were observed, and the results are shown in Table 1.

Example 2
A conductive film was produced and measured in the same manner as in Example 1, except that the amount of KM-3951 was increased to 80 g and the amount of CAT-PM-10A was increased to 8 g in Example 1. The results are shown in Table 1.

Example 3
A conductive film was prepared and measured in the same manner as in Example 1, except that the amount of KM-3951 was reduced to 20 g and the amount of CAT-PM-10A was reduced to 2 g. The results are shown in Table 1.

Example 4
A conductive film was produced and measured in the same manner as in Example 1, except that the amount of Arrowbase DC-1010J2 in Example 1 was increased to 80 g. The results are shown in Table 1.

Example 5
A conductive film was produced and measured in the same manner as in Example 1, except that the amount of Arrowbase DC-1010J2 in Example 1 was reduced to 20 g. The results are shown in Table 1.

Example 6
A conductive film was prepared and measured in the same manner as in Example 1, except that KM-3951 in Example 1 was changed to X-52-6068 (addition-curing silicone emulsion, solids content 30%, aqueous dispersion, manufactured by Shin-Etsu Chemical Co., Ltd.). The results are shown in Table 1.

Example 7
A conductive film was prepared and measured in the same manner as in Example 1, except that Arrowbase DC-1010J2 in Example 1 was changed to Arrowbase DC-1010 (manufactured by Unitika Ltd., carboxyl group-containing polyolefin resin emulsion, solids content 26.5%, aqueous dispersion). The results are shown in Table 1.

(Example 8)
A conductive film was prepared and measured in the same manner as in Example 1, except that 0.3 g of sodium bicarbonate was added to the conductive polymer dispersion in Example 1. The results are shown in Table 1.

(Comparative Example 1)
A coating material was prepared in the same manner as in Example 1, except that the PEDOT-PSS aqueous dispersion was not added, and a film was prepared by coating the coating material and then measured. The results are shown in Table 1.

(Comparative Example 2)
A conductive film was prepared and measured in the same manner as in Example 1, except that KM-3951 and CAT-PM-10A were not added. The results are shown in Table 1.

(Comparative Example 3)
A conductive film was prepared and measured in the same manner as in Example 1, except that Arrowbase DC-1010J2 was not added. The results are shown in Table 1.

<Evaluation>
[Surface resistance value]
For the conductive film of each example, the surface resistance value of the conductive release 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 measurement results of the surface resistance value are shown in Table 1. In the table, "Ω/□" means ohms per square. "1.0E+09" represents "1.0 × 10 ⁹ ," and the same applies to the others.

[Peeling force]
For the conductive film of each example, the peel force was measured by the following method, and the releasability of the conductive release layer was evaluated.
A 25 mm wide polyester adhesive tape (Nitto Denko Corporation, No. 31B) was attached to the surface of the conductive release layer of the conductive film, and a load of 1976 Pa was applied to the adhesive tape, followed by a pressure treatment at 25°C for 20 hours. Next, in accordance with JIS Z0237, the adhesive tape attached to the conductive release layer was peeled off at an angle of 180° (peel rate 0.3 m/min) using a tensile tester, and the peel force (unit: N/25 mm) was measured. The measurement results are shown in Table 1. A smaller peel force means a higher releasability of the release layer.

[Adhesion]
For the conductive film of each example, the surface of the conductive release layer was rubbed with a finger 10 times, and the degree of damage to the conductive release layer was evaluated according to the following criteria. The results are shown in Table 1.
(Rating 1): The conductive release layer completely falls off within the fifth finger rub, and the conductive release layer loses its conductivity and easy peelability. In other words, the adhesion between the conductive release layer and the polypropylene film is poor.
(Evaluation 2): The conductive release layer remains after the first 5 finger rubs, but after that, by the 10th finger rub, the conductive release layer completely falls off, losing conductivity and easy peelability. In other words, the adhesion between the release layer and the polypropylene film is poor.
(Evaluation 3): The conductive release layer did not fall off within 10 finger rubs, but a significant change in color of the conductive release layer was observed, and the conductivity and ease of peeling were reduced. In other words, the adhesion between the conductive release layer and the polypropylene film was normal.
(Rating 4): The conductive release layer did not fall off within 10 finger rubs, and although a small change in color of the conductive release layer was observed, the conductivity and ease of peeling were hardly reduced. In other words, the adhesion between the conductive release layer and the polypropylene film was excellent.
(Evaluation 5): The conductive release layer did not fall off within 10 finger rubs, the color of the conductive release layer did not change, and the conductivity and ease of peeling were not reduced. In other words, the adhesion between the conductive release layer and the polypropylene film was particularly excellent.
In the above five-point evaluation criteria, the ease of peeling (releasability) is based on the results of testing the ease of peeling off an adhesive tape that has been applied to a surface rubbed with a finger. The discoloration of the conductive release layer indicates the degree of peeling at the interface between the conductive release layer and the polypropylene film. If this interface is partially peeled off, the interface will lift up when peeling off an adhesive tape applied to the surface of the conductive release layer, resulting in reduced peelability.

The conductive polymer dispersions of Examples 1 to 8 contain a silicone emulsion and a carboxyl group-containing polyolefin resin, and therefore the conductive release layer formed from the coating film has good conductivity and releasability, and the conductive release layer has excellent adhesion to the substrate. The conductive polymer dispersion of Example 8 contains a basic compound, which improves wettability to the substrate. The paint of Comparative Example 1 does not contain a conductive complex, and therefore the formed coating film has poor conductivity as well as poor releasability. These results demonstrate that the conductive complex improves the releasability of the silicone emulsion in the examples.
The conductive polymer dispersion of Comparative Example 2 does not contain a silicone emulsion, and therefore the releasability of the formed conductive layer is significantly poor.
The conductive polymer dispersion of Comparative Example 3 does not contain a carboxy group-containing polyolefin resin, and therefore the conductive layer formed has poor adhesion to the substrate.
Examples 1 to 7 are reference examples.

Claims (6)

A conductive polymer dispersion liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, a silicone emulsion, a carboxy group-containing polyolefin resin, an aqueous dispersion medium , and a basic compound,
the content of the conductive complex is 0.15% by mass or more and 1.0% by mass or less with respect to the total mass of the conductive polymer dispersion,
a solid content of the silicone emulsion is 0.5% by mass or more and 3.5% by mass or less with respect to the total mass of the conductive polymer dispersion,
the content of the carboxy group-containing polyolefin resin is 100 parts by mass or more and 5000 parts by mass or less relative to 100 parts by mass of the conductive composite,
the content of the carboxy group-containing polyolefin resin is 30 parts by mass or more and 500 parts by mass or less per 100 parts by mass of the solid content of the silicone emulsion,
The content of water relative to 1 part by mass of the conductive composite is 80 parts by mass or more and 400 parts by mass or less,
the aqueous dispersion medium contains a water-soluble organic solvent, and the content of the water-soluble organic solvent relative to the total mass of the aqueous dispersion medium is 60 mass% or more and 85 mass% or less;
The conductive polymer dispersion, wherein the basic compound is an inorganic alkali, and the content of the inorganic alkali relative to the total mass of the conductive polymer dispersion is 1 mM or more and 10 mM or less . The conductive polymer dispersion according to claim 1 , further comprising a platinum-based catalyst. 2. 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. A substrate and a conductive release layer formed on at least a portion of the surface of the substrate,
A conductive laminate, wherein the conductive release layer is a cured product of the conductive polymer dispersion according to any one of claims 1 to 3 . The conductive laminate according to claim 4 , wherein the substrate is a polypropylene film. A method for producing a conductive laminate, comprising: applying the conductive polymer dispersion according to any one of claims 1 to 3 to at least a part of the surface of a substrate to form a conductive layer.