JP6906745B1 - Method for producing conductive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a conductive composition for obtaining a conductive coating film capable of suppressing both increase and decrease of surface resistance with time. The following steps (i) to (iii): (i) A preliminary dispersion containing a conductive polymer which is a complex of poly (3,4-disubstituted thiophene) and a poly anion, and water. The step of obtaining, (ii) the step of dispersing the conductive polymer in the preliminary dispersion to obtain the dispersion, and (iii) the step of dispersing the dispersion, selected from the group consisting of an alkaline compound, an aqueous diluent, and an aqueous resin 1 The steps of adding the above are provided in this order, and the following steps (iv): (iv) are provided between the steps (i) and the steps (ii) and / or between the steps (ii) and the steps (iii). ) A method for producing a conductive composition, which comprises a step of aging the preliminary dispersion liquid or the dispersion liquid at 1 to 40 ° C. for 180 hours or more. [Selection diagram] None

Description

The present invention relates to a method for producing a conductive composition. More specifically, the present invention relates to a method for producing a conductive composition, which comprises a step of aging the conductive polymer before or after it is dispersed.

Since resin products have high electrical insulation, static electricity is likely to be generated by contact, peeling, and friction. This static electricity causes dust to adhere to the resin product. Further, in an electronic device including a resin member, the discharge of static electricity and the incident of electromagnetic waves can cause damage to the electronic device and noise.

In order to prevent the generation of static electricity on the surface of a resin product and noise of electronic devices, a method of applying a conductive composition in which a conductive polymer is dispersed in a solvent to the surface of the resin product is known. As such a conductive polymer, a π-conjugated conductive polymer such as polyaniline or polythiophene is used. On the other hand, the conductive coating film containing these conductive polymers has a problem that the conductivity changes with the passage of time after the film is formed, and it is difficult to maintain the desired conductivity.

Conventionally, a technique for improving the stability of the conductivity of a coating film over time has been known. That is, in Patent Document 1, when a water-soluble antioxidant is added to an aqueous solution in which a conductive polymer is dispersed, a coating film formed using the aqueous solution has resistance over time when exposed to air. It discloses that the rise can be suppressed. On the other hand, the resistance of the conductive coating film may decrease over time. In particular, in recent years, the quality level of display films requires control of not only the upper limit but also the lower limit of surface resistance, and it has been required to suppress a decrease in surface resistance with time.

JP-A-2010-196022

An object of the present invention is to obtain a conductive composition for obtaining a conductive coating film capable of suppressing both an increase and a decrease in surface resistance with time.

The present inventors carry out a step of highly dispersing the conductive polymer in water by a disperser, and further carry out a step of aging at 1 to 40 ° C. for 180 hours or more before or after the step to make the conductive polymer conductive. We have found that the arrangement of the conductive polymer in the conductive composition can be stabilized, and that the conductive coating film formed of this conductive composition can maintain the conductivity stably, and completed the present invention.

That is, in the present invention, the following steps (i) to (iii):
(I) A step of obtaining a preliminary dispersion liquid containing a conductive polymer which is a complex of poly (3,4-disubstituted thiophene) and a poly anion, and water.
(Ii) A step of subjecting the preliminary dispersion to a disperser to obtain a dispersion, and (iii) a step of adding one or more selected from the group consisting of an alkaline compound, an aqueous diluent, and an aqueous resin to the dispersion. Have in this order
Between step (i) and step (ii) and / or between step (ii) and step (iii),
The following process (iv):
(Iv) The present invention relates to a method for producing a conductive composition, which comprises a step of aging the preliminary dispersion liquid or the dispersion liquid at 1 to 40 ° C. for 180 hours or more.

In the above manufacturing method, it is preferable to carry out the step (iv) twice or more.

It is preferable that the production method further includes a step of aging the dispersion liquid at 1 to 40 ° C. for 180 hours or more after the step (iii).

In the production method, it is preferable that the conductive composition contains a low molecular weight anion.

In the above production method, it is preferable that the aqueous diluent contains a water-soluble organic solvent.

In the production method, the content of the water-soluble organic solvent in the entire conductive composition is preferably 1% by weight or more.

Further, the present invention is selected from the group consisting of a conductive polymer, water, which is a composite of poly (3,4-disubstituted thiophene) and polyanion, and an alkaline compound, an aqueous diluent, and an aqueous resin. Including 1 or more to be
Formula: (Surface resistivity after leaving at 25 ° C. for 24 hours) / (Surface resistivity immediately after film formation) × 100
The present invention relates to a conductive composition for forming a conductive coating film having a rate of change in surface resistivity represented by 90 to 110%.

The conductive composition preferably has a pH of 2-11.

In the conductive composition, it is preferable that the conductive coating film is formed through a drying step of 130 ° C. or lower.

It is preferable that the conductive composition is for forming a conductive coating film on a thermoplastic resin base material having a glass transition temperature of 180 ° C. or lower.

By the method for producing a conductive composition of the present invention, a conductive composition in which the arrangement of conductive polymers is stabilized can be obtained. The conductive coating film formed by using this conductive composition can stably maintain the conductivity after the film formation.

<< Manufacturing method of conductive composition >>
The method for producing the conductive composition of the present invention comprises the following steps (i) to (iii):
(I) A step of obtaining a preliminary dispersion liquid containing a conductive polymer which is a complex of poly (3,4-disubstituted thiophene) and a poly anion, and water.
(Ii) A step of subjecting the preliminary dispersion to a disperser to obtain a dispersion, and (iii) a step of adding one or more selected from the group consisting of an alkaline compound, an aqueous diluent, and an aqueous resin to the dispersion. Have in this order
Between step (i) and step (ii) and / or between step (ii) and step (iii),
The following process (iv):
(Iv) The pre-dispersion liquid or the dispersion liquid has a step of aging at 1 to 40 ° C. for 180 hours or more.

<Step of obtaining preliminary dispersion (i)>
In step (i), a preliminary dispersion liquid containing a conductive polymer which is a composite of poly (3,4-disubstituted thiophene) and poly anion, and water is obtained. The conductive polymer, which is a complex of poly (3,4-disubstituted thiophene) and polyanion, and water may be mixed, and the mixing order is not particularly limited. The conductive polymer may be further compounded with a low molecular weight anion described later.

The conductive polymer can be obtained by oxidatively polymerizing 3,4-disubstituted thiophene with an oxidizing agent. The polyanion which is a dopant may be charged before the oxidative polymerization, or may be added after the oxidative polymerization. The conductive polymer after oxidative polymerization may be subjected to solvent substitution if necessary. When converting 3,4-disubstituted thiophene to poly (3,4-disubstituted thiophene) in a mixture of poly anion, water, an oxidizing agent, etc. to form a complex with poly anion. , You do not have to add new water. When the preliminary dispersion is obtained by this method, it is preferable to remove or inactivate the oxidizing agent before proceeding to the next step.

As the poly (3,4-disubstituted thiophene) constituting the conductive polymer, poly (3,4-dialkoxythiophene) or poly (3,4-alkylenedioxythiophene) is preferable. The poly (3,4-dialkoxythiophene) or poly (3,4-alkylenedioxythiophene) has the following formula (I):

A cationic form of polythiophene consisting of the repeating structural units represented by is preferred. Here, R ¹ and R ² independently represent a hydrogen atom or _{an alkyl group of C 1-4} , or are bonded to each other to represent an alkylene group of _{C 1-4.} The alkyl group of C _1-4 is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. .. When R ¹ and R ² are bonded, _{the alkylene group of C 1-4} is not particularly limited, but for example, a methylene group, a 1,2-ethylene group, a 1,3-propylene group, 1, 4-butylene group, 1-methyl-1,2-ethylene group, 1-ethyl-1,2-ethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, etc. Can be mentioned. Among these, a methylene group, a 1,2-ethylene group and a 1,3-propylene group are preferable, and a 1,2-ethylene group is more preferable. Alkyl C _1-4, and _an alkylene group of _{C 1-4,} a portion of the hydrogen may be substituted. As the _{polythiophene having an alkylene group of C 1-4} , poly (3,4-ethylenedioxythiophene) is particularly preferable.

The weight average molecular weight of the conductive polymer is preferably 500 to 100,000, more preferably 1,000 to 10,000, and even more preferably 1,200 to 5,000. If the weight average molecular weight is less than 500, it may not be possible to secure the viscosity required for the conductive composition, or the conductivity when the coating film is formed may be lowered.

The poly anion is a dopant of poly (3,4-disubstituted thiophene) and forms a complex by forming an ion pair with poly (3,4-disubstituted thiophene) to form a poly (3,4-disubstituted thiophene). Thiophene) can be stably dispersed in water.

The polyanion is not particularly limited, but is, for example, carboxylic acid polymers (for example, polyacrylic acid, polymaleic acid, polymethacrylic acid, etc.), sulfonic acid polymers (for example, polystyrene sulfonic acid, polyvinylsulfonic acid, polyisoprene, etc.). Sulfonic acid, etc.) and the like. These carboxylic acid polymers and sulfonic acid polymers are also copolymers of vinyl carboxylic acids and vinyl sulfonic acids with other polymerizable monomers, such as acrylates, styrene, vinyl naphthalene and other aromatic vinyl compounds. It may be. Among these, polystyrene sulfonic acid is preferable, polystyrene sulfonate is more preferable, and amine salt or ammonium salt of polystyrene sulfonic acid is further preferable.

The amine salt of polystyrene sulfonic acid is not particularly limited as an amine, but for example, trimethylamine (TMA), triethylamine (TEA), tri-n-propylamine (TPA), tri-n-butylamine (TBA), ethyldimethyl. Examples include amines, N, N-dimethylethanolamine, morpholine and the like. These may be used alone or in combination of two or more.

The polystyrene sulfonic acid preferably has a weight average molecular weight of 1,000,000 to 1,000,000, and more preferably 30,000 to 500,000. If polystyrene sulfonic acid having a molecular weight outside this range is used, the dispersion stability of the conductive polymer in water may decrease. The weight average molecular weight is a value measured by gel permeation chromatography (GPC).

The conductive polymer is preferably a complex of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid from the viewpoint of particularly excellent conductivity.

The conductivity of the conductive polymer is not particularly limited, but is preferably 0.01 S / cm or more, and more preferably 1 S / cm or more.

In the preliminary dispersion, the amount of the polyanion compounded with respect to 100 parts by weight of poly (3,4-disubstituted thiophene) is preferably 100 to 500 parts by weight, more preferably 150 to 400 parts by weight.

Further, in the solid content of the finally obtained conductive composition, the blending amount of poly (3,4-disubstituted thiophene) is preferably 0.1 to 30% by weight, more preferably 0.1 to 20% by weight. .. The amount of the polyanion compounded in the solid content of the finally obtained conductive composition is preferably 0.1 to 50% by weight, more preferably 1 to 40% by weight.

<Step of obtaining dispersion (ii)>
In the step (ii), the preliminary dispersion liquid obtained in the step (i) is subjected to a disperser to obtain a dispersion liquid. The disperser is not particularly limited as long as it can reduce the viscosity of the preliminary dispersion liquid, and examples thereof include an ultrasonic disperser, a bead mill, a high-speed homogenizer, and a high-pressure homogenizer. Since the distribution of the conductive polymer can be made uniform by the dispersion, the change in conductivity with the passage of time can be suppressed. Furthermore, aggregation and gelation during the aging process can be suppressed.

When a high-pressure homogenizer is used as the disperser, the pressure is preferably 10 to 1000 MPa, more preferably 20 to 200 MPa. The number of treatments is preferably 1 to 100 times, more preferably 1 to 10 times.

<Step of adding alkaline compound, aqueous diluent, or aqueous resin (iii)>
In the step (iii), an alkaline compound, an aqueous diluent, or an aqueous resin is added to the dispersion obtained in the step (iii).

It is preferable to add an alkaline compound to the dispersion to neutralize it. This is because the conductive polymer, which is a complex of poly (3,4-disubstituted thiophene) and poly anion, is often strongly acidic with a pH of 1.0 to 3.5, and is an aqueous resin that remains strongly acidic. Is added, it may agglomerate depending on the type of the aqueous resin, and the agglomeration becomes particularly remarkable in a high concentration state during drying after the coating film is formed. The pH of the dispersion is preferably 4 to 10, more preferably 5 to 9, and even more preferably 6 to 9 by blending the alkaline compound. The type of the alkaline compound is not particularly limited, and examples thereof include a base containing an alkali metal or an alkaline earth metal, NH ₃ , a nitrogen-based aliphatic compound, a nitrogen-based aromatic compound, and the like. When an aqueous resin that can be crosslinked under acidic conditions is used, or when the film forming equipment is sufficiently protected against corrosion, it is not necessary to add the alkaline compound.

Examples of the base containing an alkali metal or an alkaline earth metal include sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium hydrogencarbonate, and potassium hydrogencarbonate. Examples of the nitrogen-based aliphatic compound include triethanolamine, ethanolamine, diethanolamine, dimethylamine, diethylamine, dipropylamine, trimethylamine, triethylamine, and tripropylamine. Examples of the nitrogen-based aromatic compound include imidazole, 2-methylimidazole, 2-propylimidazole, 1- (2-hydroxyethyl) imidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-. Examples thereof include cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-aminobenzimidazole, pyridine, aniline, and toluidine. As the alkaline compound, two kinds may be used alone, or two or more kinds may be used. Among these, NH ₃ , a nitrogen-based aliphatic compound, and a nitrogen-based aromatic compound are preferable, and NH ₃ , Nitrogen-based aliphatic compounds are more preferable, and triethanolamine and NH ₃ are even more preferable. The amount of the alkaline compound added is not particularly limited as long as the amount of the alkaline compound added is such that a predetermined pH is achieved for the finally obtained conductive composition.

The aqueous diluent is added to the dispersion for solids adjustment, dispersion stabilization of the conductive composition, and efficiency of step (iv). Examples of the aqueous diluent include water and a water-soluble organic solvent.

Examples of the water-soluble organic solvent include alcohols, ethylene glycols, amide compounds and the like. Examples of the alcohol include ethanol, methanol, 2-propanol, 1-propanol and the like. Examples of ethylene glycols include ethylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol and the like. Examples of the amide compound include acetonitrile, N-methylformamide, N, N-dimethylformamide, γ-butyrolactone, N-methylpyrrolidone and the like. As the aqueous diluent, a mixed solution of water and a water-soluble organic solvent may be used. When a mixed solution is used, the concentration of the water-soluble organic solvent is preferably 0 to 50% by weight, more preferably 0 to 40% by weight, still more preferably 0 to 30% by weight.

When the aqueous diluent contains a water-soluble organic solvent, the amount of the water-soluble organic solvent added is preferably 1% by weight or more, more preferably 2% by weight or more, still more preferably 5% by weight or more of the entire conductive composition. If it is less than 1% by weight, the surface resistivity of the coating film tends to be too high, the rate of change in the surface resistivity tends to be large, and the coatability during film formation tends to be poor.

By adding the water-based resin, the film-forming property and strength of the coating film formed by the conductive composition can be improved. Examples of the water-based resin include acrylic resin, polyether resin, polyester resin, polyurethane resin, polyolefin resin, siloxane, and oxazoline resin. The aqueous resin is preferably soluble or dispersible in water in order to facilitate blending with the conductive polymer. The resin may be solubilized or dispersed as a result of imparting a hydrophilic functional group, or may be forcibly solubilized or dispersed by an emulsifier.

The aqueous resin is preferably a mixture of 2 or more selected from the group consisting of acrylic resin, polyether resin, polyester resin, polyurethane resin, polyolefin resin, siloxane, and oxazoline resin, and is preferably a mixture of 3 or more. More preferred. Further, it is more preferable that the mixture of two or more contains at least one of the group selected from the acrylic resin, polyurethane resin, and polyolefin resin. By using such a mixture of two or more, the adhesive strength between the coating film formed by the conductive composition and the substrate is stably exhibited.

Examples of the acrylic resin include (meth) acrylic resin and vinyl ester resin. These acrylic resins constitute a polymerizable monomer having an acid group such as a carboxyl group, an acid anhydride group, a sulfonic acid group or a phosphoric acid group, and a fluoro group such as a perfluoroalkyl group or a perfluoroalkenyl group. It may be a polymer containing as. For example, a polymerized monomer having an acid group alone or a copolymer, a copolymer of a polymerizable monomer having an acid group and a copolymerizable monomer, and the like can be mentioned.

The (meth) acrylic resin may be polymerized with the copolymerizable monomer as long as it contains the (meth) acrylic monomer as the main constituent monomer (for example, 50 mol% or more). It is preferable that at least one of the (meth) acrylic monomer and the copolymerizable monomer has an acid group.

Examples of the (meth) acrylic resin include (meth) acrylic monomers having an acid group [(meth) acrylic acid, sulfoalkyl (meth) acrylate, sulfonic acid group-containing (meth) acrylamide, etc.] or a copolymer thereof. A polymer, a (meth) acrylic monomer having an acid group, and another polymerizable monomer having an acid group [another polymerizable carboxylic acid, a polymerizable polyvalent carboxylic acid or an anhydride , Vinyl aromatic sulfonic acid, etc.] and / or copolymerizable monomer [for example, (meth) acrylic acid alkyl ester, glycidyl (meth) acrylate, (meth) acrylonitrile, aromatic vinyl monomer, etc.] Polymer, other polymer monomer having an acid group and (meth) acrylic copolymer [for example, (meth) acrylic acid alkyl ester, hydroxyalkyl (meth) acrylate, glycidyl (meth) acrylate, Copolymer with (meth) acrylonitrile, etc.], (meth) acrylic monomer having no acid group [alkyl (meth) acrylate, aryl (meth) acrylate (fluorene-based (meth) acrylate, etc.] or its Examples thereof include copolymers, rosin-modified urethane acrylates, specially modified acrylic resins, urethane acrylates, epoxy acrylates, and urethane acrylate emulsions.

Among these (meth) acrylic resins, (meth) acrylic acid- (meth) acrylic acid ester polymer (acrylic acid-methyl methacrylate copolymer, etc.), (meth) acrylic acid- (meth) acrylic acid An ester-styrene copolymer (acrylic acid-methyl methacrylate-styrene copolymer, etc.) and the like are preferable.

Examples of the polyether resin include polyalkylene glycol, polyvinyl alcohol, polyether polyol, polyglycerin, pullulan, and derivatives thereof. These polyether resins have an acid group such as a carboxyl group, an acid anhydride group, a sulfonic acid group and a phosphoric acid group, a fluoro group such as a perfluoroalkyl group and a perfluoroalkenyl group, and an alkyl group and an alkenyl group. You may do it.

As the polyester resin, a method of polycondensing a compound having two or more carboxyl groups in the molecule and a compound having two or more hydroxyl groups, a method of directly dehydrating and polycondensing a hydroxycarboxylic acid, and a cyclic hydroxycarboxylic acid. The compound is not particularly limited as long as it is a polymer compound obtained by a method for ring-opening polymerization of an ester. For example, a compound having two or more hydroxyl groups (diol component) includes an aliphatic diol, an alicyclic diol, and an aromatic acid. Examples thereof include group diols, (poly) carbonate diols, polyether diols, polyester diols, and the like, and examples of the compound (dicarboxylic acid component) having two or more carboxyl groups in the molecule include aliphatic dicarboxylic acids and aromatic dicarboxylic acids. Examples thereof include alicyclic dicarboxylic acid, and examples of the cyclic ester of hydroxycarboxylic acid include lactide, glycolide, ε-caprolactone and the like. Examples of the general name of the obtained polymer compound include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate and the like. These polyester resins have an acid group such as a carboxyl group, an acid anhydride group, a sulfonic acid group and a phosphoric acid group, a fluoro group such as a perfluoroalkyl group and a perfluoroalkenyl group, and an alkyl group and an alkenyl group. You may be.

The polyurethane resin is not particularly limited as long as it is a polymer compound obtained by copolymerizing a compound having an isocyanate group and a compound having a hydroxyl group, and for example, an ester ether polyurethane resin, an ether polyurethane resin, and a polyester. Examples thereof include polyurethane resins, carbonate polyurethane resins, and acrylic polyurethane resins. These polyurethane resins may have a nonionic, anionic or cationic hydrophilic polar group introduced therein. As the source of introducing the hydrophilic polar group, a linear nonionic hydrophilic polar group such as a poly (oxyethylene) polyol, -COOM, -SO ₃ M (M is an alkali metal, an ammonium group, or an organic amine) is used. Anionic hydrophilic polar groups such as (shown)) and cationic hydrophilic polar groups such as quaternary ammonium salts can be mentioned.

Examples of the polyolefin resin include polyethylene, polypropylene, poly-4-methyl-1-pentene, poly-1-butene, chlorinated polypropylene, maleic anhydride-modified polypropylene, maleic anhydride-modified chlorinated polypropylene and the like. These polyolefin resins include α-olefin comonomer such as butene-1, penten-1, hexene-1, hepten-1, octene-1, cyclopentene, cyclohexene, norbornene, vinyl acetate, acrylic acid ester, methacrylic acid ester and the like. It may be a copolymer with the comonomer of, carboxylic acid group (-COOH), sulfo group (-SO ₃ H), sulfino group (-SO ₂ H), phosphono group (-PO ₂ H), vinyl. Hydrophilic polar groups such as an alcohol chain, a vinylpyrrolidone chain, and an ether chain may be introduced.

The siloxane is an alkoxysilane monomer represented by the following formula (II), or an alkoxysilane whose molecular weight has been increased in advance by condensing these monomers with each other, and has a siloxane bond (Si—O—Si) of 1. Examples thereof include those having one or more in a molecule.
SiR ₄ (II)
(In the formula, R is a hydrogen, a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, an alkyl group which may have a substituent, and a phenyl group which may have a substituent. However, of the four Rs At least one of them is an alkoxy group or a hydroxyl group having 1 to 4 carbon atoms.) When a monomer of alkoxysilane is used, it may be added to the conductive composition and then increased in molecular weight in the conductive composition. good.

The structure of the siloxane is not particularly limited, and may be linear or branched. Further, as the siloxane, the compound represented by the formula (II) may be used alone, or two or more kinds may be used in combination. These siloxanes may be modified with a polyether group, a polyalkyl group, a polyester group, or a polyol group. The shape of the modification may be linear or branched. The weight average molecular weight of the siloxane is not particularly limited, but is preferably greater than 4000 and 500,000 or less, and more preferably 5000 to 20000. Here, the weight average molecular weight is a value measured by gel permeation chromatography (GPC).

Examples of the oxazoline resin include addition-polymerizable oxazoline compounds such as 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline and 2-vinyl-4-methyl-2-oxazoline. Examples of commercially available products include Epocross WS-300, WS-500 and WS-700 (manufactured by Nippon Shokubai Co., Ltd.). By blending the oxazoline resin, cross-linking is generated between the conductive polymers, and the strength of the conductive coating film can be improved.

The content of the aqueous resin in the conductive composition is not particularly limited, but is preferably 10 to 5000 parts by weight, more preferably 30 to 3000 parts by weight, and further 50 to 2000 parts by weight with respect to 100 parts by weight of the conductive polymer. preferable. Within this range, sufficient conductivity can be ensured in the coating film formed by the conductive composition.

<Arbitrary ingredient>
In the present invention, antioxidants, low molecular weight anions, cross-linking agents, surfactants, fillers, defoamers, neutralizers, thickeners and the like may be added in any of the steps.

By adding an antioxidant, an increase in pH of the conductive composition can be suppressed. Examples of the antioxidant include ascorbic acid, erythorbic acid, compounds having a lactone ring substituted with two hydroxyl groups such as salts thereof, and phenols such as gallic acid, methyl gallate, propyl gallate, and tannic acid. Examples thereof include compounds having two or more sex hydroxyl groups. When an antioxidant is added, the amount of the antioxidant added is preferably 10 to 500 parts by weight, more preferably 20 to 300 parts by weight, based on 100 parts by weight of the conductive polymer. The antioxidant is preferably added in step (iii).

By adding a low molecular weight anion, the stabilization of the arrangement of poly (3,4-disubstituted thiophene) and poly anion can be promoted. The weight average molecular weight of the low molecular weight anion is preferably 1000 or less. Low molecular weight anions include aromatic sulfonic acids such as p-toluene sulfonic acid, ethylbenzene sulfonic acid and dodecylbenzene sulfonic acid; aliphatic sulfonic acids such as methane sulfonic acid and trifluoromethane sulfonic acid, formic acid, acetic acid, oxalic acid and benzoic acid. Acids, organic carboxylic acids such as trifluoroacetic acid, inorganic acids such as hydrochloric acid, sulfuric acid, nitrate, phosphoric acid, borohydrogenic acid, hydrofluoric acid, perchloric acid, Lewis acids such as PF5, AsF5, SbF5, BF5, etc. Can be mentioned. Aromatic sulfonic acid and aliphatic sulfonic acid are particularly preferable. The amount of the low molecular weight anion added is preferably 0.1 to 100 parts by weight, more preferably 1 to 40 parts by weight, still more preferably 10 to 30 parts by weight, based on 100 parts by weight of the polyanion. The low molecular weight anion is preferably added in step (i) in order to promote the stabilization of the arrangement of the poly (3,4-disubstituted thiophene) and the poly anion.

By adding a cross-linking agent, the aqueous resin can be cross-linked and the strength of the coating film after the conductive composition is applied can be improved. The cross-linking agent is preferably soluble in an aqueous diluent, more preferably soluble in water. Examples of the cross-linking agent include melamine-based, oxazoline-based, epoxy-based, and alkoxysilane-based compounds. These cross-linking agents may be used alone or in combination of two or more. When a cross-linking agent is added, the content thereof is preferably 0.1 to 30% by weight based on the solid content of the conductive composition.

The melamine compound is not particularly limited, and examples thereof include a methylated melamine compound and a butylated melamine compound, and commercially available products include Nicarac MW-30M (manufactured by Sanwa Chemical Co., Ltd.) and Cymel 303LF (Orne). Kus Japan Co., Ltd.) etc. These may be used in combination of two or more.

The oxazoline-based compound is not particularly limited, and examples thereof include addition-polymerizable oxazoline compounds such as 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline and 2-vinyl-4-methyl-2-oxazoline. Examples of commercially available products include Epocross WS-300, WS-500 and WS-700 (manufactured by Nippon Catalyst Co., Ltd.). These may be used in combination of two or more.

The epoxy compound is not particularly limited, but for example, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether. , Sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether and other aliphatic polyepoxy compounds, and commercially available products such as Denacol EX-521 and EX-614 (manufactured by Nagase ChemteX Corporation) can be used. be. These may be used in combination of two or more.

Examples of the alkoxysilane-based compound are an alkoxysilane represented by the following formula (III) and an alkoxysilane oligomer formed by condensing alkoxysilanes with each other, and have a siloxane bond (Si—O—Si) of 1. Examples thereof include oligomers having one or more in the molecule.
SiR ₄ (III)
(In the formula, R is hydrogen, a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms, an alkyl group which may have a substituent, and a phenyl group which may have a substituent. However, of the four Rs At least one of them is an alkoxy group or a hydroxyl group having 1 to 4 carbon atoms.)

The structure of the alkoxysilane oligomer is not particularly limited, and it may be linear or branched. Further, as the alkoxysilane oligomer, the compound represented by the formula (III) may be used alone, or two or more kinds may be used in combination. The weight average molecular weight of the alkoxysilane oligomer is not particularly limited, but is preferably larger than 152 and 4000 or less, and more preferably 500 to 2500. Here, the weight average molecular weight is a value measured by gel permeation chromatography (GPC).

By adding a surfactant to the conductive composition, the leveling property of the conductive composition can be improved. By using such a conductive composition, a uniform coating film can be formed.

The surfactant is not particularly limited as long as it has an effect of improving leveling property, and is a carboxylic acid such as coconut oil fatty acid amine salt and gum rosin; castor oil sulfate esters, phosphate esters, alkyl ether sulfates, and sorbitan fatty acids. Ester compounds such as esters, sulfonic acid esters, and succinic acid esters; sulfonate compounds such as alkylaryl sulfonic acid amine salts and dioctyl sodium sulfosuccinate; phosphate compounds such as sodium lauryl phosphate; coconut oil fatty acid ethanol amide and the like. Examples of the amide compound and the like. These surfactants may be used alone or in combination of two or more.

When the conductive composition contains a surfactant, the content is preferably 0 to 40% by weight, more preferably 0.01 to 10% by weight, based on the solid content of the conductive composition.

The filler is not particularly limited, and examples thereof include an inorganic filler and an organic filler having a crosslinked structure. Specific examples of the material of the inorganic filler are not particularly limited, but for example, in addition to silica such as colloidal silica, hollow silica and fumed silica and metal oxides such as titania and zirconia, thermoplastic or thermocurable. A core-shell type acrylic-silica composite in which the acrylic resin is coated with silica, a core-shell type melamine-silica composite in which the melamine resin is coated with silica, and a core-shell type in which silica is coated with a thermoplastic or thermosetting acrylic resin. Organic-inorganic composites such as acrylic-silica composites, core-shell melamine-silica composites in which silica is coated with melamine resin, and acrylic-silica composites in which small silica is supported by a thermoplastic or thermocurable acrylic resin. And so on. Specific examples of the material of the organic filler are not particularly limited, and examples thereof include fluororesin, acrylic resin, melamine resin, urethane rubber, and the like. These fillers may be used alone or in combination of two or more. When the filler is added, the content thereof is preferably 0.1 to 30% by weight, more preferably 0.2 to 10% by weight, based on the solid content of the conductive composition.

<Aging process (iv)>
In step (iv), a pre-dispersion solution or dispersion is placed between steps (i) and step (ii) and / or between step (ii) and step (iii) at 1 to 40 ° C. for 180 hours. Aged as above. A mixture of poly (3,4-disubstituted thiophene) and polyanion takes a long time to stabilize the arrangement of both, and a conductive composition in which the arrangement of the conductive polymer is not stabilized forms a film. Since the conductivity gradually fluctuates later, it is difficult to stably produce a laminate having the desired conductivity. In the present invention, the arrangement of poly (3,4-disubstituted thiophene) and polyanions is stabilized by undergoing a step of aging at 1 to 40 ° C. for 180 hours or more, and a laminate having desired conductivity is stabilized. Can be produced as a target.

The aging temperature is 1 to 40 ° C, preferably 2 to 40 ° C, more preferably 3 to 35 ° C. If the temperature is lower than 1 ° C., the preliminary dispersion liquid or the dispersion liquid freezes, and if the temperature exceeds 40 ° C., the conductive polymer tends to aggregate and the coating property, conductivity, and transparency tend to be impaired.

The aging time is 180 hours or more, preferably 200 hours or more, more preferably 200 to 20000 hours, still more preferably 300 to 10000 hours. In less than 180 hours, the arrangement of poly (3,4-disubstituted thiophene) and polyanion is not sufficiently stabilized, and the conductivity tends to fluctuate when a conductive coating film is formed. The upper limit of the aging time is not particularly limited, but if it exceeds 20000 hours, the conductive polymer may aggregate. It is preferable that the aging is carried out by storing the pre-dispersion liquid or the dispersion liquid in an arbitrary container and allowing it to stand in a place not exposed to the sun or giving weak sliding as appropriate. Containers to be accommodated include glass containers, stainless steel containers, polyethylene terephthalate, polyarylate, polyethylene naphthalate, polycarbonate, polyethylene, polytetrafluoroethylene, polypropylene, polybutylene terephthalate, polyimide, polymethylpentene, and polystyrene. Examples thereof include a copolymer of the monomers to be used, a plastic container in which two or more kinds containing these materials are combined, and the like, and a plastic container is preferable. If the stirring is continued using a stirrer at the time of aging, the stabilization of the arrangement of poly (3,4-disubstituted thiophene) and the poly anion is hindered and the aging efficiency is lowered. Therefore, it is preferable not to perform stirring.

Further, in addition to the step (iv), the conductive composition may be aged at 1 to 40 ° C. for 180 hours or more after the step (iii), in which case the aging is carried out under the conditions described for the step (iv). It can be carried out.

In the production method of the present invention, aging is preferably carried out twice or more, and more preferably three times or more. For example, aging may be carried out between steps (i) and step (ii) and between steps (ii) and step (iii). Further, it may be performed between the step (i) and the step (ii), between the step (ii) and the step (iii), and after the step (iii). Among these, it is preferable that the aging is performed between the step (i) and the step (ii). By aging the predisperse, the arrangement of poly (3,4-disubstituted thiophene) and polyanions can be stabilized more efficiently.

The solid content concentration of the finally obtained conductive composition is preferably 0.05 to 10%, more preferably 0.1 to 8%. The pH of the conductive composition is preferably pH 2-11, more preferably pH 6-11. Under strongly acidic conditions of less than pH 2, metal corrosion of the production line may occur, and when the film thickness of the coating film formed of the conductive composition is thin, the surface resistivity may increase.

<< Conductive composition and conductive coating film >>
Further, the conductive composition of the present invention comprises a conductive polymer, water, which is a composite of poly (3,4-disubstituted thiophene) and a poly anion, as well as an alkaline compound, an aqueous diluent, and an aqueous resin. Including one or more selected from the group consisting of
Formula: (Surface resistivity after leaving at 25 ° C. for 24 hours) / (Surface resistivity immediately after film formation) × 100
It is a conductive composition for forming a conductive coating film in which the rate of change of surface resistivity represented by is 90 to 110%.

In the conductive composition of the present invention, the arrangement of poly (3,4-disubstituted thiophene) and poly anion can be stabilized, thereby obtaining a coating film in which fluctuations in conductivity are suppressed. can. Therefore, the conductive coating film formed of the conductive composition of the present invention is
Formula: (Surface resistivity after leaving at 25 ° C. for 24 hours) / (Surface resistivity immediately after film formation) × 100
The rate of change of the surface resistivity represented by is 90 to 110%, but is preferably 93 to 108%. The surface resistivity refers to a value obtained by measuring by the method described in Examples after forming a conductive coating film on a base material.

The conductive coating film is obtained by applying a conductive composition on a substrate and drying it. Examples of the material of the base material include thermoplastic resin, glass, metal and the like, and among them, thermoplastic resin is preferable. Examples of the thermoplastic resin include polyester resins, acrylic resins, cycloolefin resins, polyolefin resins, cellulose resins, and polycarbonate resins. Among these, those having a glass transition temperature of 180 ° C. or lower are preferable, and those having a glass transition temperature of 160 ° C. or lower are preferable. The one is more preferable. Examples of the polyester resin include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). Examples of the acrylic resin include polymethyl methacrylate resin (PMMA). Examples of the cycloolefin resin include a cycloolefin polymer resin (COP). Examples of the polyolefin resin include polyethylene resin and polypropylene resin. Examples of the cellulosic resin include triacetyl cellulose (TAC) resin. The thickness of the base material is preferably 10 to 1000 μm, more preferably 25 to 500 μm. The total light transmittance of the base material is preferably 60% or more, more preferably 70% or more.

The method for applying the conductive composition is not particularly limited, and for example, a roll coating method, a bar coating method, a dip coating method, a spin coating method, a spray coating method, a screen printing method, an inkjet printing method, or the like can be used.

Drying after application of the conductive composition is not particularly limited as long as water and other volatile solvents contained in the conductive composition can be removed, and for example, a blower oven, an infrared oven, a vacuum oven, or the like may be used. .. The drying temperature is preferably 130 ° C. or lower, more preferably 100 ° C. or lower, and even more preferably 40 to 80 ° C. The drying time is preferably 5 minutes or less, more preferably 0.3 to 3 minutes.

The conductive polymer, water, alkaline compound, aqueous diluent, and aqueous resin, which are composites of poly (3,4-disubstituted thiophene) and polyanions, contained in the conductive composition have been described above.

The film thickness of the conductive coating film is preferably 1 to 300 nm, more preferably 5 to 250 nm, and even more preferably 10 to 200 nm.

When the conductive coating film is a thick film (70 to 300 nm), the surface resistivity immediately after the formation of the conductive coating film is preferably 10 to 10000 Ω / sq, more preferably 30 to 2000 Ω / sq. When the conductive coating film is a thin film (1 to 70 nm), 10 ⁴ to 10 ¹⁰ Ω / sq is preferable, and 10 ⁵ to 10 ⁹ Ω / sq is more preferable.

<< Laminated body >>
By applying the conductive composition of the present invention on a base material, a laminate composed of the base material and the conductive coating film can be obtained. This laminated body can stably maintain conductivity, and can be suitably used for a surface protective film, a transparent conductive film, an antistatic film, and the like.

The present invention will be described with reference to examples, but the present invention is not limited to the following examples. Hereinafter, "parts" or "%" means "parts by weight" or "% by weight", respectively, unless otherwise specified.

(Main materials used)
1. 1. Conductive polymer 3,4-ethylenedioxythiophene (manufactured by Tokyo Chemical Industry Co., Ltd.)
-Polystyrene sulfonic acid (PSS) aqueous solution (manufactured by AkzoNobel Co., Ltd., TL-72, solid content 17%)
2. Low molecular weight anion, p-toluenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.)
3. 3. Aqueous resin / acrylic resin A (manufactured by Big Chemie Japan, BYK-350)
-Acrylic resin B (manufactured by Nippon Carbide, Nikazol RX-3020)
-Polyurethane resin (made by ADEKA, ADEKA Bontiter HUX-895)
-Polyester resin (manufactured by Toagosei, Aronmelt PES-2405A30)
-Polyolefin resin (manufactured by TOYOBO, Hardlen EW-5303)
4. Antioxidant, ascorbic acid (manufactured by Tokyo Chemical Industry Co., Ltd.)
5. Solvent / ethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ N-Methylpyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd .: NMP)
・ Ethanol (manufactured by Tokyo Chemical Industry Co., Ltd.)
6. Resin base material, triacetyl cellulose resin (manufactured by Fujifilm, Fujitac TJ25UL: TAC)
-Polyethylene terephthalate resin (manufactured by Toray, Lumirror T60: PET)
-Cycloolefin resin (Zeon Corporation, Zeonoa ZF-14: COP)
・ Acrylic resin (created in Production Example 1)

(Production Example 1) Production of acrylic resin base material (meth) acrylic resin having a lactone ring structure (copolymerization monomer weight ratio = methyl methacrylate / 2- (hydroxymethyl) methyl acrylate = 8/2, lactone cyclization The rate is about 100%, the content of the lactone ring structure is 19.4%, the weight average molecular weight is 133000, the melt flow rate is 6.5 g / 10 minutes (240 ° C., 10 kgf), 90 parts by weight of Tg131 ° C.), and acrylonitrile-styrene (AS). ) Pellets of a mixture (Tg 127 ° C) with 10 parts by weight of resin (Toyo AS AS20, manufactured by Toyo Styron Co., Ltd.) are supplied to a biaxial extruder, melt-extruded into a sheet at about 280 ° C, and lactone having a thickness of 110 μm. A (meth) acrylic resin sheet having a ring structure was obtained. This unstretched sheet was stretched 2.0 times in length and 2.4 times in width under a temperature condition of 160 ° C. (thickness: 40 μm, in-plane retardation Δnd: 0. 8 nm, thickness direction phase difference Rth: 1.5 nm) was obtained.

(Examples 1 to 14, Comparative Examples 1 to 5)
(1) Production of conductive composition (i) Production of preliminary dispersion liquid Poly (3,4-disubstituted thiophene), poly anion, and small molecule shown in Tables 1 and 2 according to the following Synthesis Examples 1 to 5. The anions were mixed in water to produce a pre-dispersion solution.

(Synthesis Example 1)
Using a 3000 ml glass flask equipped with a cooling tube, 104.4 parts of a polystyrene sulfonic acid aqueous solution, 7.1 parts of 3,4-ethylenedioxythiophene (EDOT), and 1700 parts of ion-exchanged water were added to the ion-exchanged water. A mixture was obtained. While stirring this mixed solution, a solution prepared by dissolving 4.0 parts of ferric sulfate and 14.8 parts of ammonium peroxodisulfate in 100 parts of ion-exchanged water was added, and the mixture was stirred at 10 ° C. for 24 hours for oxidative polymerization. Was done. Next, the reaction mixture obtained was passed through a column packed with a cation exchange resin (Amberlite IR120B, manufactured by Organo Corporation) and an anion exchange resin (Amberlite IRA67, manufactured by Organo Corporation) to oxidize. After removing the residue of the agent and the catalyst, a preliminary dispersion having a solid content of 1.3% was obtained.

(Synthesis Example 2)
Using a 3000 ml glass flask equipped with a cooling tube, 104.4 parts of polystyrene sulfonic acid aqueous solution, 3.6 parts of p-toluenesulfonic acid, 7.1 parts of 3,4-ethylenedioxythiophene (EDOT), ion-exchanged water. Was added to 1900 parts of ion-exchanged water to obtain a mixed solution. While stirring this mixed solution, a solution prepared by dissolving 0.1 part of ferric sulfate and 13.1 part of ammonium peroxodisulfate in 100 parts of ion-exchanged water was added, and the mixture was stirred at 10 ° C. for 24 hours for oxidative polymerization. Was done. Next, the reaction mixture obtained was passed through a column packed with a cation exchange resin (Amberlite IR120B, manufactured by Organo Corporation) and an anion exchange resin (Amberlite IRA67, manufactured by Organo Corporation) to oxidize. After removing the residue of the agent and the catalyst, a preliminary dispersion having a solid content of 1.3% was obtained.

(Synthesis Example 3)
Using a 3000 ml glass flask equipped with a cooling tube, 83.5 parts of an aqueous polystyrene sulfonic acid solution, 3.6 parts of p-toluenesulfonic acid, 7.1 parts of 3,4-ethylenedioxythiophene (EDOT), and ion-exchanged water. Was added to 1900 parts of ion-exchanged water to obtain a mixed solution. While stirring this mixed solution, a solution prepared by dissolving 0.1 part of ferric sulfate and 13.1 part of ammonium peroxodisulfate in 100 parts of ion-exchanged water was added, and the mixture was stirred at 10 ° C. for 24 hours for oxidative polymerization. Was done. Next, the reaction mixture obtained was passed through a column packed with a cation exchange resin (Amberlite IR120B, manufactured by Organo Corporation) and an anion exchange resin (Amberlite IRA67, manufactured by Organo Corporation) to oxidize. After removing the residue of the agent and the catalyst, a preliminary dispersion having a solid content of 1.3% was obtained.

(Synthesis Example 4)
Using a 3000 ml glass flask equipped with a cooling tube, 125.3 parts of polystyrene sulfonic acid aqueous solution, 7.1 parts of p-toluenesulfonic acid, 7.1 parts of 3,4-ethylenedioxythiophene (EDOT), ion-exchanged water. Was added to 2500 parts of ion-exchanged water to obtain a mixed solution. While stirring this mixed solution, a solution prepared by dissolving 0.1 part of ferric sulfate and 13.1 part of ammonium peroxodisulfate in 100 parts of ion-exchanged water was added, and the mixture was stirred at 10 ° C. for 24 hours for oxidative polymerization. Was done. Next, the reaction mixture obtained was passed through a column packed with a cation exchange resin (Amberlite IR120B, manufactured by Organo Corporation) and an anion exchange resin (Amberlite IRA67, manufactured by Organo Corporation) to oxidize. After removing the residue of the agent and the catalyst, a preliminary dispersion having a solid content of 1.3% was obtained.

(Synthesis Example 5)
Using a 3000 ml glass flask equipped with a cooling tube, 106.3 parts of polystyrene sulfonic acid aqueous solution and 0.6 parts of p-toluenesulfonic acid, 7.1 parts of 3,4-ethylenedioxythiophene (EDOT), ion-exchanged water. Was added to 1700 parts of ion-exchanged water to obtain a mixed solution. While stirring this mixed solution, a solution prepared by dissolving 0.1 part of ferric sulfate and 13.1 part of ammonium peroxodisulfate in 100 parts of ion-exchanged water was added, and the mixture was stirred at 10 ° C. for 24 hours for oxidative polymerization. Was done. Next, the reaction mixture obtained was passed through a column packed with a cation exchange resin (Amberlite IR120B, manufactured by Organo Corporation) and an anion exchange resin (Amberlite IRA67, manufactured by Organo Corporation) to oxidize. After removing the residue of the agent and the catalyst, a preliminary dispersion having a solid content of 1.3% was obtained.

(Ii) Dispersion of Conductive Polymer The conductive polymer contained in the preliminary dispersion liquid was highly dispersed by a high-pressure homogenizer under the conditions shown in Tables 1 and 2 to produce a dispersion liquid of the conductive polymer. The measurement results of the viscosity before and after the step (ii) are shown in Tables 1 and 2. The viscosity was measured with a B-type viscometer under the condition of 25 ° C.

(Iii) Addition of alkaline compound, aqueous diluent, and aqueous resin to the dispersion liquid The aqueous resin, antioxidant, solvent, and alkaline compound shown in Tables 1 and 2 were added to the dispersion liquid of the conductive polymer. In Tables 1 and 2, the water content indicates the total amount of water blended in steps (i) and (iii).

(Iv) Aging During the above steps (i) to (ii), between (ii) to (iii), and after (iii), the pre-dispersion liquid or the dispersion liquid is placed at the temperatures shown in Tables 1 and 2. And aged under time conditions. The pH of the conductive composition finally obtained after aging is shown in Tables 1 and 2. Since the step (ii) was not carried out in Comparative Example 5, the aging step was carried out between the steps (i) and (iii).

(2) Formation of Conductive Coating Film The conductive composition is coated on a resin base material using a wire bar, and under the conditions for producing a thick film or a thin film shown in Tables 1 and 2. By drying, a conductive coating film was formed on the resin substrate.

(3) Surface resistivity of Conductive Coating Film (Thick Film) The wire bar count was adjusted so that the surface resistivity immediately after formation was 500Ω / sq, and the conductive coating film was formed on the resin base material. Immediately after forming the conductive coating film on the resin substrate and after storing at 25 ° C. for 24 hours, the probe ESP, using the Loresta GP (MCP-T610, trade name) manufactured by Mitsubishi Chemical Corporation, according to JIS K7194. The surface resistivity was measured at an applied voltage of 10 V. The rate of change in surface resistivity was calculated by the following formula, and the results are shown in Tables 1 and 2. However, in Comparative Example 3, since the conductivity was low, it was not possible to form a film achieving 500Ω / sq.
(% change rate of surface resistivity) = (surface resistivity after storage at 25 ° C. for 24 hours) / (surface resistivity immediately after coating film formation) × 100

(4) Surface resistivity of conductive coating film (thin film) After diluting the conductive composition with water so that the solid content is 2%, select the wire bar count so that the coating thickness is 5 μm. A conductive coating film was formed on the resin substrate. Immediately after forming the conductive coating film on the resin substrate and after storing at 25 ° C. for 24 hours, the probe was used by Mitsubishi Chemical Corporation's High Resta UP (MCP-HT-450, trade name) according to JIS K7194. The surface resistivity was measured at UA and an applied voltage of 10 V to 500 V. The rate of change in surface resistivity was calculated by the following formula, and the results are shown in Tables 1 and 2.
(% change rate of surface resistivity) = (surface resistivity after storage at 25 ° C. for 24 hours) / (surface resistivity immediately after coating film formation) × 100

In Comparative Examples 1 and 2, the aging time between the steps (i) to (ii) and between (ii) to (iii) was less than 180 hours, so that the obtained conductive composition was used. In the formed coating film, the change in surface resistivity was large in both the thick film and the thin film. The thick film formed of the conductive composition of Comparative Example 3 had a remarkably high resistance value and could not be measured, and the thin film had a large change in resistivity. In Comparative Example 4, since it was aged at a high temperature of 45 ° C., the surface resistivity of both the thick film and the thin film changed significantly, and the surface resistivity of the thin film also became a high value. Since the step (ii) was not performed in Comparative Example 5, the change in the surface resistivity of both the thick film and the thin film was large, and the surface resistivity of the thin film was also high.

In Examples 1 to 14, aging was carried out between steps (i) to (ii) or between (ii) to (iii) at an appropriate temperature for 180 hours or more, so that the conductive composition was formed. As for the coating film, the rate of change in surface resistivity of both the thick film and the thin film was suppressed within the range of 90 to 110%.

Claims (8)

The following steps (i) to (iii):
(I) A step of obtaining a preliminary dispersion liquid containing a conductive polymer which is a complex of poly (3,4-disubstituted thiophene) and a poly anion, and water.
(Ii) A step of subjecting the preliminary dispersion to a disperser to obtain a dispersion, and (iii) a step of adding one or more selected from the group consisting of an alkaline compound, an aqueous diluent, and an aqueous resin to the dispersion. Have in this order
Between step (i) and step (ii) and / or between step (ii) and step (iii),
The following process (iv):
(Iv) A method for producing a conductive composition, which comprises a step of aging the preliminary dispersion liquid or the dispersion liquid at 1 to 40 ° C. for 200 hours or more. The method for producing a conductive composition according to claim 1, wherein the step (iv) is performed twice or more. The method for producing a conductive composition according to claim 1 or 2, further comprising a step of aging the dispersion liquid at 1 to 40 ° C. for 180 hours or more after the step (iii). The method for producing a conductive composition according to any one of claims 1 to 3, wherein the conductive composition contains a low molecular weight anion. The method for producing a conductive composition according to any one of claims 1 to 4, wherein the aqueous diluent contains a water-soluble organic solvent. The method for producing a conductive composition according to claim 5, wherein the content of the water-soluble organic solvent in the entire conductive composition is 1% by weight or more. The amount of the aqueous resin added is 507.1 parts by weight or more with respect to 100 parts by weight of the conductive polymer.
The method for producing a conductive composition according to any one of claims 1 to 6. Further, the step of adding the cross-linking agent at a concentration of 30% by weight or less in the solid content is included.
The method for producing a conductive composition according to claim 7.