JP6849271B2 - Method for manufacturing conductive film - Google Patents

Description

The present invention relates to a method for producing a conductive film formed by stretching.

Resin films are used in a wide range of applications because they are excellent in processability and can be imparted with a wide variety of properties. On the other hand, the resin film is generally insulating and easily charged with static electricity, so that it has a disadvantage that impurities and dust adhere to it, and combustibles are easily ignited by electric discharge. In particular, in the electrical and electronic fields, when a resin film is used for an electronic component, the electronic component may be damaged.
For this reason, in particular, resin films used in applications such as electrical and electronic fields are required to be provided with antistatic performance. For example, an antistatic film made of a resin film coated with a conductive film has been conventionally used for bags for packaging electronic parts, surface protective films, temporary adhesive tapes, and the like.

Further, in touch panels, organic electroluminescence elements, thin-film solar cells and the like, transparent electrodes in which a transparent conductive film is formed on a transparent resin film are used.

Conventionally, the conductive substance used for the above-mentioned conductive film has been a surfactant, carbon, metal, metal oxide, or the like, but in recent years, a conductive polymer has attracted attention as an alternative to these. Has been done.
For example, in Patent Document 1, a coating liquid containing a conductive polymer (conductive polymer resin) and a polyurethane resin as a binder is applied onto a uniaxially stretched polyester film to form an antistatic layer, and the antistatic layer is formed. A method for producing a biaxially stretched antistatic polyester film by re-stretching the polyester film on which the above-mentioned material is formed has been proposed.
Further, Patent Document 2 describes a transparent conductive film including a base material and a conductive layer containing conductive polymer (conductive polymer) particles having a large aspect ratio and a binder resin.

Further, as a method for producing a conductive polymer dispersion used as a coating liquid for forming a conductive film, for example, in Patent Document 3, a monomer for obtaining a conjugated conductive polymer is protected by a polyanion. A method of obtaining a conductive polymer dispersion liquid by polymerizing in a dispersion medium containing colloidal seed particles has been proposed.

By the way, in the processing of a resin film, stretching treatment is generally performed for the purpose of thinning, improving heat resistance and cold resistance, imparting heat shrinkage (shrinkability), imparting polarization characteristics, and improving mechanical strength. It is done in the same way. According to the so-called in-line coating, in which the coating process for forming the conductive film and such a stretching process are continuously performed, the stretching process of the uncoated resin film and the coating process are separated from each other. It has the advantages that the manufacturing equipment can be reduced and the manufacturing cost can be suppressed, and the thickness of the conductive film can be adjusted by the draw ratio, as compared with the so-called offline coating performed in the above.

Japanese Unexamined Patent Publication No. 2010-37533 Japanese Unexamined Patent Publication No. 2014-26875 International Publication No. 2014/142133

Although the conductive polymer dispersion liquid described in Patent Document 3 contains seed particles, thickening of the dispersion liquid is suppressed and excellent productivity can be obtained, but the dispersion liquid can be used. The coating layer formed by using it as a coating liquid has a problem that when it is stretched to form a conductive film, the rate of decrease in conductivity with respect to the degree of stretchability is large.

The present invention has been made to solve the above technical problems, and when a coating film formed by using a coating liquid containing a conductive polymer is stretched to form a conductive film, the conductive film is formed. It is an object of the present invention to provide a method for producing a conductive film capable of suppressing a decrease in the conductivity of the above.

The present invention focuses on the morphology of particles containing a conductive polymer in a coating liquid for forming a conductive film, and deforms the particles as the coating layer is stretched by the coating liquid to form a conductive film. This was done based on the finding that the decrease in conductivity is suppressed.

That is, the present invention provides the following [1] to [15].
[1] A step of preparing a coating liquid containing a composite particle of a polymer seed particle protected and colloidalized with a polyanion and a conjugated conductive polymer, and a binder, and coating the polymer film base material with the coating liquid. The step of forming the coating layer by drying and the step of heating and stretching the coating layer to form a conductive film are included, and the glass transition temperature of the protective colloidalized polymer seed particles is the stretching temperature in the heating and stretching. A method for producing a conductive film, which is characterized by being lower than.
[2] The method for producing a conductive film according to the above [1], wherein the glass transition temperature is lower than the stretching temperature by 10 ° C. or more.
[3] The method for producing a conductive film according to the above [1] or [2], wherein the polymer seed particles are composed of a polymer containing one or more kinds of ethylenically unsaturated monomers as a constituent unit.
[4] The method for producing a conductive film according to any one of [1] to [3] above, wherein the content of the composite particles in the solid content of the coating liquid is 1 to 70% by mass.
[5] The method for producing a conductive film according to any one of [1] to [4] above, wherein the composite particles are provided as a dispersion in the step of preparing the coating liquid.
[6] The method for producing a conductive film according to any one of the above [1] to [5], wherein the binder is a thermoplastic resin.
[7] The binder is selected from polyester resin, acrylic resin, polyurethane resin, polyvinyl alcohol resin, polyamide resin, polyimide resin, vinyl ester resin, polystyrene resin, polyvinyl chloride resin, polyolefin resin, polycarbonate resin and cellulose resin. The method for producing a conductive film according to any one of the above [1] to [6], which is one or more of the above.
[8] The monomer which is a constituent unit of the conjugated conductive copolymer may have a pyrrole which may have a substituent, an aniline which may have a substituent, and a substituent. The method for producing a conductive film according to any one of the above [1] to [7], which comprises one or more selected from thiophene.
[9] The item according to any one of [1] to [8] above, wherein the monomer which is a constituent unit of the conjugated conductive copolymer contains a compound represented by the following formula (1). Method for manufacturing conductive film.

(In the formula (1), R ¹ and R ² independently have a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms which may have a substituent, and a carbon number which may have a substituent. Any of 1 to 18 alkoxy groups or alkyl thio groups having 1 to 18 carbon atoms which may have a substituent, or a substituent in which R ¹ and R ² are bonded to each other to form a ring. An alicyclic ring having 3 to 10 carbon atoms which may have a substituent, an aromatic ring having 6 to 10 carbon atoms which may have a substituent, and an oxygen atom-containing complex having 3 to 10 ring members which may have a substituent. A ring, a sulfur atom-containing heterocycle having 3 to 10 ring members which may have a substituent, or a sulfur atom and oxygen atom-containing heterocycle having 3 to 10 ring members which may have a substituent are shown.)
[10] The method for producing a conductive film according to any one of [1] to [9] above, wherein the polyanion is a polymer having a group consisting of sulfonic acid or a salt thereof.
[11] The above [1] to 30 mol, the content of the anionic group in the polyanion is 0.25 to 30 mol with respect to 1 mol of the monomer which is a constituent unit of the conjugated conductive copolymer. The method for producing a conductive film according to any one of [10].

[12] The method for producing a conductive film according to any one of [1] to [11] above, wherein the conductive film is a transparent conductive film.
[13] Production of the conductive film according to any one of [1] to [12] above, wherein in the heat stretching, the coating layer is peeled off from the polymer film base material and then only the coating layer is stretched. Method.
[14] The method for producing a conductive film according to any one of [1] to [12] above, wherein in the heat stretching, the coating layer on the polymer film base material is stretched together with the polymer film base material.
[15] A method for producing an antistatic film, which comprises obtaining an antistatic film composed of the conductive film and the polymer film base material by the production method according to the above [14]. Film manufacturing method.

According to the present invention, when a coating film formed by using a coating liquid containing a conductive polymer is stretched to form a conductive film, a decrease in the conductivity of the conductive film can be suppressed. Manufacturing method is provided.
Therefore, the method for producing a conductive film of the present invention can be suitably used for producing a transparent conductive film, an antistatic film, or the like.

It is a graph which showed the relationship between the stretch ratio and the conductivity of the conductive film in Examples 1 and 2 and Comparative Example 1. It is a graph which showed the relationship between the stretch ratio of the conductive film and the conductivity in Example 3 and Comparative Example 2. It is a graph which showed the relationship between the stretch ratio of the conductive film and the conductivity in Example 4 and Comparative Example 3.

Hereinafter, the present invention will be described in detail.
The method for producing a conductive film of the present invention includes a step of preparing a coating liquid containing composite particles of a polymer seed particle protected and colloidalized with a polyanion and a conjugated conductive polymer, and a binder, and a polymer using the coating liquid. It includes a step of coating a film base material and drying it to form a coating layer, and a step of heating and stretching the coating layer to form a conductive film.
That is, the method for producing a conductive film of the present invention goes through a coating liquid preparation step, a coating layer forming step using the coating liquid, and a conductive film forming step by heating and stretching the coating layer.
The term "polyanion" as used in the present invention means a polymer having two or more anionic groups. Further, "protective colloidalization" means protecting the surface of the polymer seed particles with a polyanion.

The present invention is characterized in that the glass transition temperature of the protective colloidalized polymer seed particles is lower than the stretching temperature in the heat stretching.
As described above, when the glass transition temperature of the protective colloidalized polymer seed particles is lower than the stretching temperature, it is possible to suppress the decrease in the conductivity of the conductive film due to stretching. This is because by heating and stretching at a stretching temperature that is higher than the glass transition temperature, the polymer seed particles are also deformed following the stretching, and the expansion of the distance between each composite particle due to stretching is suppressed. It is presumed that there is.

[Coating liquid preparation process]
In this step, as a coating liquid for forming a coating layer, a coating liquid containing composite particles of a polymer seed particle protected and colloidalized with a polyanion and a conjugated conductive polymer and a binder is prepared.
Specifically, a coating liquid is obtained by mixing composite particles, a binder, and other components added as needed in a dispersion medium.

(Composite particles)
The composite particles referred to here are composite particles of a polymer seed particle protected and colloidalized with a polyanion and a conjugated conductive polymer. More specifically, the particles are in a state where the polyanion is coordinated on the surface of the polymer seed particle to form a protective colloid, and the polyanion is doped in the conjugated conductive polymer.

The content of the conjugated conductive polymer in the composite particles is 2.7 to 77% by mass from the viewpoint of the conductivity of the coating layer formed by using the coating liquid containing the conjugated conductive polymer. It is preferably 3.2 to 50% by mass, more preferably 3.9 to 44% by mass.
Further, the content of the polymer seed particles in the polymer seed particles protected by the polyanion is 10 to 100 with respect to 100 parts by mass of the polyanion from the viewpoint of the stability of the polymer seed particles protected by the polyanion. It is preferably parts by mass, more preferably 20 to 90 parts by mass, and even more preferably 30 to 60 parts by mass.

The content of the composite particles in the solid content of the coating liquid is a value assuming that the entire amount of the conjugated conductive polymer is composited with the polymer seed particles, and can be calculated from the amount of raw materials charged at the time of preparing the coating liquid. .. The content of the composite particles is preferably 1 to 70% by mass, more preferably 5 to 70% by mass, still more preferably 30 to 70, from the viewpoint of the conductivity of the conductive film and the strength against stretching of the coating film. It is mass%.

(Polymer seed particles)
Polymer seed particles are particles that are protected colloidalized by polyanions in a dispersion medium. As the polymer seed particles, for example, those composed of a polymer containing one or more kinds of ethylenically unsaturated monomers as a constituent unit are preferable. The polymer may be one kind alone, a mixture of two or more kinds, and may be either crystalline or amorphous. In the case of crystallinity, the crystallinity is preferably 50% or less.
The ethylenically unsaturated monomer may have one or more polymerizable ethylenic carbon-carbon double bonds. For example, a (meth) acrylate having a linear, branched or cyclic alkyl group; an aromatic vinyl compound such as styrene or α-methylstyrene; a heterocyclic vinyl compound such as vinylpyrrolidone; a hydroxyalkyl (meth) acrylate; Dialkylaminoalkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate; vinyl esters such as vinyl acetate and vinyl alkanoate; monoolefins such as ethylene, propylene, butylene and isobutylene; conjugated diolefins such as butadiene, isoprene and chloroprene Α, β-unsaturated mono or dicarboxylic acids such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid; vinyl cyanide compounds such as acrylonitrile; carbonyl group-containing vinyl such as acrylonitrile and diacetoneacrylamide. Examples include compounds. These may be used alone or in combination of two or more.
In the present specification, "(meth) acrylic" refers to acrylic or methacrylic, and "(meth) acrylate" refers to acrylate or methacrylate.
Of these, the ethylenically unsaturated monomer preferably contains an aromatic vinyl compound, and more preferably contains styrene. In this case, the aromatic vinyl compound is preferably contained in an amount of 10% by mass or more, more preferably 20 to 100% by mass, still more preferably 30 to 100% by mass, among the ethylenically unsaturated monomers.

Further, the ethylenically unsaturated monomer may contain a crosslinkable monomer, and may be crosslinked with each other or in combination with an ethylenically unsaturated compound having an active hydrogen group. By using a crosslinked copolymer, the water resistance, moisture resistance, heat resistance, etc. of the conductive film can be improved. The crosslinkable monomer is a compound having two or more ethylenic carbon-carbon double bonds, or one or more ethylenic carbon-carbon double bonds and one other reactive group. The compound having the above.
Examples of the crosslinkable monomer include epoxy group-containing α, β-ethylenically unsaturated compounds such as glycidyl (meth) acrylate; hydrolyzable alkoxysilyls such as vinyltriethoxysilane and γ-methacryloxypropyltrimethoxysilane. Group-containing α, β-ethylenically unsaturated compounds; examples include polyfunctional vinyl compounds such as ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, allyl (meth) acrylate, divinylbenzene, and diallyl phthalate. ..
Further, using a crosslinkable monomer such as a carbonyl group-containing α, β-ethylenically unsaturated compound (containing a ketone group), a polyhydrazine compound (particularly, oxalic acid dihydrazide, succinate dihydrazide, adipic acid dihydrazide, etc. It may be crosslinked in combination with (having two or more hydrazide groups such as polyacrylic acid hydrazide).
The content of the crosslinkable monomer in the ethylenically unsaturated monomer is preferably 50% by mass or less, more preferably 35% by mass or less, still more preferably 25% by mass or less.

<Glass transition temperature>
In the present invention, the polymer seed particles protected and colloidalized with polyanions have a glass transition temperature lower than the stretching temperature during thermal stretching in the subsequent conductive film forming step, preferably 10 ° C. or higher, more preferably. It shall be lower than 15 ° C. When the glass transition temperature is lower than the stretching temperature in the heat stretching of the coating layer formed by using the coating liquid, it is possible to suppress a decrease in the conductivity of the conductive film formed by stretching.
The glass transition temperature is preferably −20 ° C. or higher, more preferably −10 ° C. or higher, still more preferably 0 ° C. or higher, from the viewpoint of preventing blocking of the conductive film.
The upper limit of the absolute value of the temperature difference with respect to the stretching temperature in the heat stretching of the glass transition temperature is not particularly limited as long as the resin constituting the polymer seed particles is not deteriorated by the heating stretching.

The glass transition temperature referred to in the present invention is a differential scanning calorimetry (DSC) for a sample obtained by drying a polymer seed particle protected and colloided with a polyanion in a nitrogen gas atmosphere in accordance with JIS K 7121: 2012. Scan calorimetry) is performed, and the intermediate glass transition temperature obtained from the obtained DSC curve is used. Specifically, it is measured by the method described in the following Examples.

The glass transition temperature can be estimated from the composition of the ethylenically unsaturated monomer, which is a constituent unit of the copolymer constituting the polymer seed particles, by using the following FOX formula.
1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ + ... + W _n / Tg _n
(Here, Tg is the glass transition temperature [unit: K] of the polymer having each ethylenically unsaturated monomer as a constituent unit, and W ₁ , W ₂ , ..., W _n are each ethylene. It is the weight fraction of the sex unsaturated _{monomer, Tg 1, Tg 2, ···} , Tg n is the glass transition temperature of the homopolymer of each ethylenic unsaturated monomer [unit: K] is .)
As the glass transition temperature of the homopolymer of the ethylenically unsaturated monomer used in the above calculation, the values described in publicly known documents can be used.

The combination of ethylenically unsaturated monomers is not particularly limited in controlling the glass transition temperature. For example, by using two types of a monomer having a high glass transition temperature and a monomer having a low glass transition temperature and changing the composition ratio in light of the FOX equation, the glass transition temperature is estimated and controlled. can do. Examples of the monomer having a high glass transition temperature include styrene, methyl methacrylate, cyclohexyl methacrylate, isobolonyl methacrylate and the like. Examples of the monomer having a low glass transition temperature include methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate.

(Polyanion)
The polyanion is a polymer having two or more anionic groups, which coordinates with the surface of the polymer seed particles to form a protective colloid, and functions as a dopant for a conjugated conductive polymer.
Examples of the anionic group include a group composed of sulfonic acid or a salt thereof, a group composed of phosphoric acid or a salt thereof, a monosubstituted phosphoric acid ester group, a group composed of a carboxylic acid or a salt thereof, a monosubstituted sulfuric acid ester group and the like. Be done. Among these, a strongly acidic group is preferable, a group composed of sulfonic acid or a salt thereof, a group composed of phosphoric acid or a salt thereof is more preferable, and a group composed of sulfonic acid or a salt thereof is further preferable.
The anionic group may be directly attached to the main chain of the polymer or may be attached to the side chain. When the anionic group is attached to the side chain, the doping effect becomes more remarkable, so that it is preferably attached to the end of the side chain.

The polyanion may have a substituent other than the anionic group. Examples of the substituent include an alkyl group, a hydroxy group, an alkoxy group, a phenol group, a cyano group, a phenyl group, a hydroxyphenyl group, an ester group, a halogeno group, an alkenyl group, an imide group, an amide group, an amino group and an oxycarbonyl. Examples include a group and a carbonyl group. Among these, an alkyl group, a hydroxy group, a cyano group, a hydroxyphenyl group and an oxycarbonyl group are preferable, and an alkyl group, a hydroxy group and a cyano group are more preferable. These substituents may be attached directly to the main chain of the polyanion or to the side chain. When the substituent is attached to the side chain, it is preferably attached to the end of the side chain from the viewpoint of effective action of the substituent.

The alkyl group among the substituents has an effect of improving the solubility or dispersibility in the dispersion medium, the compatibility with the conjugated conductive polymer, the dispersibility, and the like. Specific examples of the alkyl group include a chain alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group and a dodecyl group; Cycloalkyl groups such as propyl group, cyclopentyl group and cyclohexyl group can be mentioned. Considering the solubility in the dispersion medium, the dispersibility in the conjugated conductive polymer, the steric hindrance, and the like, an alkyl group having 1 to 12 carbon atoms is more preferable.
The hydroxy group facilitates the formation of hydrogen bonds with other hydrogen atoms and the like, and has the effect of improving the solubility in a dispersion medium, the compatibility and dispersibility with a conjugated conductive polymer, the adhesiveness, and the like. The hydroxy group is preferably bonded to the terminal of an alkyl group having 1 to 6 carbon atoms bonded to the main chain of the polyanion.
The cyano group and the hydroxyphenyl group have an action of improving compatibility with a conjugated conductive polymer, solubility in a dispersion medium, heat resistance and the like. The cyano group is preferably bonded directly to the main chain of the polyanion and at least at the end of an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms bonded to the main chain.
The oxycarbonyl group is preferably at least one of an alkyloxycarbonyl group and an aryloxycarbonyl group, and is preferably bonded to the main chain of the polyanion directly or via another functional group.

The composition of the main chain of the polyanion is not particularly limited. Examples of the main chain of the polyanion include polyalkylene, polyimide, polyamide, polyester and the like. Among these, polyalkylene is preferable from the viewpoint of ease of synthesis and availability.
The polyalkylene is a polymer having an ethylenically unsaturated monomer as a constituent unit, and may have a carbon-carbon double bond in the main chain. Specific examples of polyalkylene include polyethylene, polypropylene, polybutene, polypentene, polyhexene, polyvinyl alcohol, polyvinylphenol, poly (3,3,3-trifluoropropylene), polyacrylonitrile, polyacrylate, polymethacrylate, polystyrene, polybutadiene, etc. Polyisoprene and the like can be mentioned.
Specific examples of the polyimide include pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, 2,2,3,3-tetracarboxydiphenylether dianhydride, 2,2-[. 4,4'-Di (dicarboxyphenyloxy) phenyl] Obtained by polycondensation reaction of acid anhydrides such as propanedianhydride with diamines such as oxydianiline, paraphenylenediamine, metaphenylenediamine and benzophenonediamine. Examples include polymers.
Specific examples of the polyamide include nylon 6, nylon 66, nylon 610 and the like.
Specific examples of polyester include polyethylene terephthalate, polybutylene terephthalate and the like.

Among the polyanions, in particular, from the viewpoint of stability of the conjugated conductive polymer and the action of alleviating thermal decomposition, a polymer having a polyalkylene main chain and a group consisting of a sulfonic acid or a salt thereof is used. preferable. Specific examples include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, ethyl sulfonic acid polyacrylate, butyl sulfonic acid poly acrylate, poly (2-acrylamide-2-methyl propane sulfonic acid), and polyisoprene sulfonic acid. , And these alkali metal salts and the like. These polymers may be a single polymer or two or more kinds of copolymers. Among these, polystyrene sulfonic acid, polyisoprene sulfonic acid, ethyl sulfonic acid polyacrylic acid, butyl sulfonic acid polyacrylic acid, and sodium salts or potassium salts thereof are preferable from the viewpoint of imparting conductivity, and polystyrene sulfonic acid and Sodium polystyrene sulfonate is more preferred.

The polyanion preferably has a weight average molecular weight of 1,000 to 1,000,000, more preferably 10,000 to 500,000, and even more preferably 50,000 to 300,000. When the weight average molecular weight is within the above range, the solubility of the polyanion in the dispersion medium and the compatibility with the conjugated conductive polymer are good. The weight average molecular weight referred to here is a value measured as a polystyrene sulfonic acid equivalent molecular weight using gel permeation chromatography.

As the polyanion, a commercially available product may be used, or the polyanion may be obtained by synthesizing by a known method. Examples of the method for synthesizing the polyanion include the methods described in JP-A-2005-76016 and Houben-Weyl, “Methoden der organischen Chemie”, Vol.E20, Makromolekulare Stoffe, No.2, 1987, p.1141. Can be mentioned.

The content of anionic groups in the polyanion is 0.25 to 1 mol of the monomer, which is a constituent unit of the conjugated conductive polymer, from the viewpoint of obtaining composite particles having sufficient conductivity and dispersibility. It is preferably 30 mol, more preferably 0.8 to 25 mol, still more preferably 1 to 20 mol.

(Conjugated conductive polymer)
The conjugated conductive polymer referred to in the present invention is an organic polymer compound having a π-conjugated system in the main chain, and is not particularly limited as long as it is such a polymer compound. Examples of the conjugated conductive polymer include polypyrroles, polythiophenes, polyacetylenes, polyphenylenes, polyphenylene vinylenes, polyanilines, polyacenes, polythiophene vinylenes, and copolymers thereof. Among these, polypyrroles, polyanilines and polythiophenes are preferable, and polythiophenes are more preferable. Further, the conjugated conductive polymer preferably has a substituent such as an alkyl group, a carboxy group, a sulfonic acid group, an alkoxy group, a hydroxyl group or a cyano group from the viewpoint of obtaining high conductivity. The "class" in the compound notation referred to in the present specification means a compound group containing the compound structure, and for example, polypyrroles refer to a compound group containing a polypyrrole structure.

Specific examples of preferable conjugated conductive polymers include polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-n-propylpyrrole), and 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), poly (3-methyl-4-hexyloxypyrrole) , Polypyrroles such as poly (3-methyl-4-hexyloxypyrrole); 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-octylthiophene), Poly (3-bromothiophene), poly (3-chlorothiophene), poly (3-iodothiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), Poly (3,4-dibutylthiophene), poly (3-hydroxythiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythiophene) , Poly (3-heptyloxythiophene), Poly (3-octyloxythiophene), Poly (3-decyloxythiophene), Poly (3-dodecyloxythiophene), Poly (3-octadecyloxythiophene), Poly (3, 4-dihydroxythiophene), poly (3,4-dimethoxythiophene), poly (3,4-diethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4-diheptyloxythiophene) , Poly (3,4-dioctyloxythiophene), poly (3,4-didecyloxythiophene), poly (3,4-didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), Poly (3,4-propylene dioxythiophene), poly (3,4-butylenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly (3-methyl-4-ethoxythiophene), poly (3-methyl-4-ethoxythiophene) 3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene), poly (3,4- Polythiophenes such as ethyleneoxythithiophene); polyanilins such as polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid) and poly (3-anilinesulfonic acid), etc. Can be mentioned. These may be one kind alone or a mixture of two or more kinds.
Among these, from the viewpoint of high conductivity, polypyrrole, polythiophene, poly (N-methylpyrrole), poly (3-methylthiophene), poly (3-methoxythiophene) and poly (3,4-ethylenedioxythiophene) Is preferable. In particular, poly (3,4-ethylenedioxythiophene) is preferable because it has high conductivity and excellent heat resistance.

The monomer which is a constituent unit of the conjugated conductive polymer is selected from among pyrrole which may have a substituent, aniline which may have a substituent, and thiophene which may have a substituent. It is preferable that it contains one or more selected species. In the specification of the present application, "may have a substituent" means that both the case of having a substituent and the case of not having a substituent are included.
Examples of the substituent include an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 10 carbon atoms, a heteroaryl group having 5 to 10 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and an alkoxy group having 1 to 18 carbon atoms. Examples thereof include an alkylthio group, a carboxy group, a hydroxyl group, a halogen atom and a cyano group. In addition, these alkyl group, aryl group, heteroaryl group, alkoxy group and alkylthio group may be substituted with one or more selected from carboxy group, hydroxyl group, halogen atom and cyano group. Further, two or more of the substituents may be condensed to form a ring.

Specific examples of the monomer include pyrol, N-methylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-n-propylpyrrole, 3-butylpyrrole, 3-octylpyrrole, 3-decylpyrrole, 3 -Dodecylpyrrole, 3,4-dimethylpyrrole, 3,4-dibutylpyrrole, 3-carboxypyrrole, 3-methyl-4-carboxypyrrole, 3-methyl-4-carboxyethylpyrrole, 3-methyl-4-carboxybutyl Pyrroles such as pyrrole, 3-hydroxypyrrole, 3-methoxypyrrole, 3-ethoxypyrrole, 3-butoxypyrrole, 3-hexyloxypyrrole, 3-methyl-4-hexyloxypyrrole, 3-methyl-4-hexyloxypyrrole and the like. Thiophene, 3-methylthiophene, 3-ethylthiophene, 3-propylthiophene, 3-butylthiophene, 3-hexylthiophene, 3-heptylthiophene, 3-octylthiophene, 3-decylthiophene, 3-dodecylthiophene, 3- Octadesylthiophene, 3-bromothiophene, 3-chlorothiophene, 3-iodothiophene, 3-cyanothiophene, 3-phenylthiophene, 3,4-dimethylthiophene, 3,4-dibutylthiophene, 3-hydroxythiophene, 3-methoxy Thiophene, 3-ethoxythiophene, 3-butoxythiophene, 3-hexyloxythiophene, 3-heptyloxythiophene, 3-octyloxythiophene, 3-decyloxythiophene, 3-dodecyloxythiophene, 3-octadeciloxythiophene, 3, 4-dihydroxythiophene, 3,4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3,4-dihexyloxythiophene, 3,4-diheptyl Oxythiophene, 3,4-dioctyloxythiophene, 3,4-didecyloxythiophene, 3,4-didodecyloxythiophene, 3,4-ethylenedioxythiophene, 3,4-propylene dioxythiophene, 3,4 − Butyreneoxythiophene, 3-methyl-4-methoxythiophene, 3-methyl-4-ethoxythiophene, 3-carboxythiophene, 3-methyl-4-carboxythiophene, 3-methyl-4-carboxyethylthiophene, 3- Methyl-4-carboxybutylthiophene, 3,4-ethyleneoxythi Thiophenes such as thiophene; anilines such as aniline, 2-methylaniline, 3-isobutylaniline, 2-aniline sulfonic acid and 3-aniline sulfonic acid can be mentioned. These may be used alone or in combination of two or more as long as the conjugated conductive polymer can be obtained by polymerization.

Among these, the monomer preferably contains a compound represented by the following formula (1).

In the formula (1), R ¹ and R ² independently have a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms which may have a substituent, and an alkyl group having 1 to 18 carbon atoms which may have a substituent. Any of the alkoxy groups to 18 or alkylthio groups having 1 to 18 carbon atoms which may have a substituent, or a substituent in which R ¹ and R ² are bonded to each other to form a ring. An alicyclic ring having 3 to 10 carbon atoms, an aromatic ring having 6 to 10 carbon atoms which may have a substituent, and an oxygen atom-containing heterocycle having 3 to 10 ring members which may have a substituent. , A sulfur atom-containing heterocycle having 3 to 10 ring members which may have a substituent, or a sulfur atom and oxygen atom-containing heterocycle having 3 to 10 ring members which may have a substituent. It should be noted that each of the above carbon numbers does not include the carbon number of the substituent.

Specific examples of the oxygen atom-containing heterocycle include an oxylan ring, an oxetane ring, a furan ring, a hydrofuran ring, a pyran ring, a pyrone ring, a dioxane ring, a trioxane ring and the like.
Specific examples of the sulfur atom-containing heterocycle include a thielan ring, a thietan ring, a thiophene ring, a thiane ring, a thiopyran ring, a thiopyrylium ring, a benzothiopyran ring, a dithiolane ring, a dithiolane ring, and a trithian ring.
Specific examples of the sulfur atom- and oxygen atom-containing heterocycles include an oxathiorane ring and an oxatian ring.

^{Examples of the substituent in R 1} and R ² of the above formula (1) include an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 10 carbon atoms, a heteroaryl group having 5 to 10 carbon atoms, and 1 carbon group. Examples thereof include an alkoxy group of ~ 18, an alkylthio group having 1 to 18 carbon atoms, a carboxy group, a hydroxyl group, a halogen atom, a cyano group and the like. In addition, these alkyl group, aryl group, heteroaryl group, alkoxy group and alkylthio group may be substituted with one or more of carboxy group, hydroxyl group, halogen atom and cyano group. Further, two or more of the substituents may be condensed to form a ring.

The compound represented by the formula (1) is more preferably a compound represented by the following formula (2).

In formula (2), R ³ and R ⁴ are independently any of hydrogen atoms, hydroxyl groups, alkyl groups having 1 to 4 carbon atoms which may have substituents, or R ³ and R. ^It shows an oxygen atom-containing heterocycle having 5 or 6 ring members which may have a substituent, in which 4 and 4 are bonded to each other to form a ring.
It should be noted that each of the above carbon numbers does not include the carbon number of the substituent.
R ³ and R ⁴ are preferably oxygen atom-containing heterocycles having 5 or 6 ring members, which may have substituents, in which R ³ and R ^{4 are bonded to each other to form a ring.} Examples of such an oxygen atom-containing heterocycle include a dioxane ring, a trioxane ring, and the like, and a dioxane ring is more preferable.
Of the compounds represented by the formula (2), 3,4-ethylenedioxythiophene is particularly preferable.

^{Examples of the substituent in R 3} and R ⁴ of the above formula (2) include an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 10 carbon atoms, a heteroaryl group having 5 to 10 carbon atoms, and 1 carbon group. Examples thereof include an alkoxy group of ~ 18, an alkylthio group having 1 to 18 carbon atoms, a carboxy group, a hydroxyl group, a halogen atom, a cyano group and the like. In addition, these alkyl group, aryl group, heteroaryl group, alkoxy group and alkylthio group may be substituted with one or more of carboxy group, hydroxyl group, halogen atom and cyano group. Further, two or more of the substituents may be condensed to form a ring.

(Dispersion of composite particles)
From the viewpoint of improving stability and dispersibility, the composite particles are preferably provided in the state of a dispersion liquid. In addition to the method of mixing seed particles protected and colloidalized with polyanions and a conjugated conductive polymer in a dispersion medium, the dispersion liquid of the composite particles is, for example, the conductive weight described in Patent Document 3. It can be obtained by a method for producing a dispersion containing a coalescence. Specifically, the dispersion liquid containing the composite particles can be obtained by a method of polymerizing a monomer which is a constituent unit of the conjugated conductive polymer in a dispersion medium containing seed particles protected and colloidalized with polyanions. Can be done. In this case, the liquid used for the dispersion liquid containing the composite particles can be used as it is as a part or all of the liquid for preparing the coating liquid. Further, the dispersion liquid of the composite particles may contain a composite composed of a polyanion and a conjugated conductive polymer, that is, a conductive polymer containing no polymer seed particles.

(binder)
The binder is used for the purpose of fixing composite particles on a polymer film substrate to form a conductive coating layer. Those that have film-forming properties and can be dissolved or dispersed in the dispersion medium used for the coating liquid are used. When the coating layer is stretched together with the polymer film base material during heat stretching, a material that can be stretched following the stretching of the base material is used.
As the binder, a thermoplastic resin is preferable. Even a thermosetting resin or an ultraviolet curable resin can be applied as long as it can be heat-stretched. In this case, it can be cured after stretching.

The content of the binder in the solid content of the coating liquid is preferably 30 to 70% by mass, more preferably 32, from the viewpoint of film forming property, adhesion to the polymer film substrate, conductivity of the conductive film, and the like. It is ~ 68% by mass, more preferably 35 to 65% by mass.
Further, from the viewpoint of application to in-line coating, the binder is preferably dissolved or dispersed in an aqueous medium of the coating liquid. In this case, a hydrophilic group such as a sulfonic acid group or a carboxy group may be introduced into the resin used for the binder, or a surfactant may be used to improve the dispersibility. The solid content is a non-volatile content measured as the solid content concentration in the examples described later. Specifically, it includes polyanions, polymer seed particles, conjugated conductive copolymers and other non-volatile components.

Specific examples of the binder include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; acrylic resins; polyurethane resins; polyvinyl alcohol resins; polyamides 6, polyamides 6, 6, polyamides 12, and polyamides 11. Resin; Polyimide resin; Vinyl ester resin; Polystyrene resin; Polyvinyl chloride resin; Polyolefin resin; Polycarbonate resin; Cellulosic resin; Polyether resin; Polyamideimide resin; Vinylidene fluoride, Vinyl fluoride, Polytetrafluoroethylene, Ethylenetetrafluoro Fluorine resin such as ethylene copolymer and polychlorotrifluoroethylene; vinyl resin such as polyvinyl ether, polyvinyl butyral and polyvinyl acetate; epoxy resin; urea resin; melamine resin; phenol resin; oxetane resin; xylene resin; aramid resin; Polyamide silicone resin and the like can be mentioned, and polysaccharides such as starch can also be used. These may be used alone or in combination of two or more. It can be appropriately selected and used depending on the adhesion to the polymer film base material, the application application and performance of the conductive film, and the like. Of these, polyester resin, acrylic resin, polyurethane resin, polyvinyl alcohol resin, polyamide resin, polyimide resin, vinyl ester resin, polystyrene resin, polyvinyl chloride resin, polyolefin resin, polycarbonate tree and cellulose resin are preferable, and more preferable. Polyester resin, acrylic resin, polyurethane resin and polyvinyl alcohol resin are used.
Hereinafter, the representative resin among these will be described in more detail.

<Polyester resin>
The polyester resin is a linear polyester having a dicarboxylic acid component and a polyol component as monomer constituent units. This polyester resin can be synthesized by a conventional polycondensation reaction.
The glass transition temperature of the polyester resin is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, still more preferably 40 ° C., from the viewpoint of adhesion to the polymer film substrate and suppression of blocking in the coating layer. That is all.

Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4-diphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, and phenylindandicarboxylic acid. Dimer acid and the like can be mentioned. These may be used alone or in combination of two or more. The dicarboxylic acid component is an unsaturated polybasic acid such as maleic acid, fumaric acid, itaconic acid or the like, or a hydroxycarboxylic acid such as p-hydroxybenzoic acid or p- (β-hydroxyethoxy) benzoic acid with respect to the dicarboxylic acid. It may be used in combination of 10 mol% or less, preferably 7 mol% or less, and more preferably 5 mol% or less.

The polyol components include ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, dimethylol propionic acid, and glycerin. , Trimethylol propane, poly (ethyleneoxy) glycol, poly (tetramethyleneoxy) glycol, alkylene oxide adduct of bisphenol A, alkylene oxide adduct of hydrogenated bisphenol A and the like. These may be used alone or in combination of two or more. Of these, ethylene glycol, ethylene oxide or propylene oxide adduct of bisphenol A, and 1,4-butanediol are more preferable, and ethylene oxide or propylene oxide adduct of ethylene glycol and bisphenol A are even more preferable.

When the polyester resin is dissolved or dispersed in an aqueous medium of the coating liquid, in order to improve the solubility or dispersibility, the polyester resin is a compound having a group consisting of a sulfonate or a group consisting of a carboxylic acid or a salt thereof. One or more selected from the compounds having the above may be copolymerized. The content of the monomer having these compounds as a constituent unit in the polyester resin is preferably 50 mol% or less with respect to the total of the dicarboxylic acid component and the polyol component which are the monomer constituent units of the polyester resin. , More preferably 40 mol% or less, still more preferably 30 mol% or less.
Specific examples of compounds having a group consisting of a sulfonate include 5-sodium sulfoisophthalic acid, 5-ammonium sulfoisophthalic acid, 4-sodium sulfoisophthalic acid, 4-methylammonium sulfoisophthalic acid, and 2-sodium sulfoisophthalic acid. , 5-Pasyl sulfoisophthalic acid, 4-potassium sulfoisophthalic acid, 2-potassium sulfoisophthalic acid, sulfonic acid alkali metal salts such as sodium sulfosuccinic acid, sulfonic acid amine salt compounds and the like.
Specific examples of the compound having a group consisting of a carboxylic acid or a salt thereof include trimellitic anhydride, trimellitic acid, pyromellitic anhydride, pyromellitic acid, trimesic acid, cyclobutanetetracarboxylic acid, dimethylolpropionic acid, or these. Monoalkali metal salts and the like can be mentioned. The free carboxy group is made up of a carboxylate by reacting with an alkali metal compound or an amine compound after copolymerization.

<Acrylic resin>
Acrylic resin is a polymer having an ethylenically unsaturated monomer of a type typified by a (meth) acrylic monomer as a constituent unit. It may be either a homopolymer or a copolymer. Further, it may be a block copolymer or a graft copolymer with another copolymer such as polyester or polyurethane. Further, the acrylic resin referred to here is a polymer obtained by polymerizing the ethylenically unsaturated monomer in a solution or dispersion containing another copolymer such as polyester or polyurethane, or a polymer thereof. It shall also include a mixture of.
The glass transition temperature of the acrylic resin is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, still more preferably 40 ° C. or higher, from the viewpoint of adhesion to the polymer film substrate and suppression of blocking in the coating layer. Is.

The ethylenically unsaturated monomer, which is a (meth) acrylic monomer, is not particularly limited, and specific examples thereof include (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, and maleic acid. , Carboxy group-containing monomers such as citraconic acid, and salts thereof; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, monobutylhydroquilfumarate. , A hydroxyl group-containing monomer such as monobutyl hydroxyitaconate; (meth) acrylate such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and lauryl (meth) acrylate; Examples thereof include nitrogen-containing monomers such as (meth) acrylamide, diacetone acrylamide, N-methylol acrylamide, and (meth) acrylonitrile.

Examples of the acrylic resin include styrene derivatives such as styrene, α-methylstyrene, divinylbenzene and vinyltoluene; vinyl ester compounds such as vinyl acetate and vinyl propionate; γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane. Silicon-containing compounds such as methacryloyl silicon macromer; phosphorus-containing vinyl compounds; vinyl halides such as vinyl chloride, butylidene chloride, vinyl fluoride, vinylidene fluoride, trifluorochloroethylene, tetrafluoroethylene, chlorotrifluoroethylene, and hexafluoropropylene. Compound: One or two or more polymerizable monomers selected from a conjugated diene compound such as butadiene may be copolymerized. Among the monomer constituent units of the acrylic resin, the content of these polymerizable monomers is preferably 50 mol% or less, more preferably 40 mol% or less, still more preferably 30 mol% or less. ..

<Polyurethane resin>
Polyurethane resin is a polymer having a urethane bond in the molecule. Polyurethane resin is generally synthesized by utilizing the reaction between a hydroxyl group and an isocyanato group.

As the compound containing a hydroxyl group, a polyol is preferably used, and examples thereof include a polyether polyol, a polyester polyol, a polycarbonate-based polyol, a polyolefin polyol, and an acrylic polyol. One of these compounds may be used alone, or two or more thereof may be used in combination.
Specific examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol and the like.
Examples of the polyester polyol include a reaction product of a polyvalent carboxylic acid or an acid anhydride thereof and a polyhydric alcohol. Specific examples of the polyvalent carboxylic acid include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid and the like. Specific examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-. Butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4 -Pentanediol, 2-methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexane Diol, 2,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2- Examples thereof include butyl-2-hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamine, and lactonediol.
Examples of the polycarbonate-based polyol include polycarbonate diols obtained by dealcoholization reaction from polyhydric alcohols and dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate and the like, for example, poly (1,6-hexylene) carbonate and poly (3-). Methyl-1,5-pentylene) carbonate and the like can be mentioned.

Examples of the compound containing an isocyanato group include aromatic diisocyanis such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylenedi isocyanate, naphthalenedi isocyanate, and trizine diisocyanate; α, α, α', α'-tetramethylxamethylene diisocyanate. An aliphatic diisocyanate having an aromatic ring such as isocyanate; an aliphatic diisocyanis such as methylene diisocyanis, propylene diisocyanis, lysine diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate; Examples thereof include polyisocyanate compounds such as alicyclic diisocyanates such as dicyclohexamethylene diisocyanate. These may be used alone or in combination of two or more.

A known chain extender may be used in the synthesis of the polyurethane resin. The chain extender for polyurethane having an isocyanato group at the end may be any one having two or more reactive groups with an isocyanato group, and generally, a chain extender having two hydroxyl groups or amino groups is used. ..
Examples of the chain extender having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol and butanediol; aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene; esters such as neopentyl glycol hydroxypivalate. Examples include glycols such as glycols.
Examples of the chain extender having two amino groups include aromatic diamines such as tolylene diamine, xylylene diamine, and diphenylmethanediamine; ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3-propanediamine. , 2-Methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine And other aliphatic diamines; 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isoprovilitincyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1,3 -Alicyclic diamines such as bisaminomethylcyclohexane and the like can be mentioned.

When the polyurethane resin is dissolved or dispersed in an aqueous medium of the coating liquid, the polyurethane resin is preferably water-soluble or water-dispersible. The water-soluble or water-dispersible polyurethane resin can be obtained by introducing a hydrophilic group such as a hydroxyl group, a carboxy group, a sulfonic acid group, a sulfonyl group, a phosphoric acid group and an ether group. Among these hydrophilic groups, a carboxy group or a sulfonic acid group is preferable from the viewpoint of adhesion to the polymer film substrate and physical properties of the coating layer.

<Polyvinyl alcohol resin>
The polyvinyl alcohol resin is a polymer having a polyvinyl alcohol moiety in the molecule, and known ones can be used. The polyvinyl alcohol moiety may be partially modified by acetalization, butyralization, carboxylation, or the like. In particular, partially carboxylated polyvinyl alcohol is preferable from the viewpoint of adhesion to the polymer film substrate.
The degree of polymerization of the polyvinyl alcohol resin is not particularly limited, but is usually 100 or more, and preferably 300 to 40,000 is used. The higher the degree of polymerization, the better the adhesion to the polymer film substrate, but the higher the viscosity of the coating liquid, the more preferably the degree of polymerization is 3,000 or less. Further, by mixing two or more kinds of polyvinyl alcohol resins having different degrees of polymerization, the balance between the adhesion to the polymer film substrate and the viscosity of the coating liquid can be adjusted.
The degree of saponification of the polyvinyl alcohol resin is not particularly limited, but is preferably 50 mol% or more, more preferably 60 to 100 mol%, still more preferably 70 to 99 mol% of polyvinyl acetate saponified product. Is used.

(Coating liquid)
The liquid of the dispersion medium of the coating liquid is not particularly limited as long as it can disperse the composite particles and the binder well, but from the viewpoint of application to in-line coating, an aqueous medium may be used. preferable. That is, the coating liquid is preferably a solution in which composite particles, a binder, and other components added as necessary are dissolved or dispersed in an aqueous medium.

Water is preferable as the aqueous medium, and other amides such as N-vinylpyrrolidone, hexamethylphosphortriamide, N-vinylformamide, and N-vinylacetamide; phenols such as cresol, phenol, and xylenol; methanol. , Ethanol, isopropyl alcohol, ethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, diglycerin, isoprene glycol, butanediol, 1,5-pentanediol, 1,6- Alcohols such as hexanediol, 1,9-nonanediol, neopentyl glycol; ketones such as acetone; carbonates such as ethylene carbonate and propylene carbonate; dioxane, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene Ethers such as glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether; heterocyclic compounds such as 3-methyl-2-oxazolidinone; nitriles such as acetonitrile, glutalogie nitrile, methoxy acetonitrile, propionitrile, benzonitrile, etc. Kind and the like. These may be used alone or in combination of two or more. Among these, it is preferable that it contains water.
When the composite particles are provided as a dispersion liquid in the preparation of the coating liquid, as described above, a part or all of the liquid used in the dispersion liquid can be used as it is.

Additives other than composite particles and binders may be added to the coating liquid as long as the effects of the present invention are not impaired. Examples of the additive include a plasticizer of a resin as a binder, a wetting agent for improving wettability to a polymer film substrate, a thickener, a defoaming agent, a cross-linking agent, an antioxidant, an ultraviolet absorber, and the like. Examples include colorants, flame retardants, lubricants, preservatives and the like.

The method of mixing each component of the coating liquid is not particularly limited as long as a uniform coating liquid can be obtained. For example, each component may be mixed in a state of being dissolved or dispersed in the aqueous medium, or each component other than the composite particles may be added to the dispersion liquid of the composite particles. The order of addition of each component is also not particularly limited.
Any means may be used for mixing as long as the dispersion stability of each component is not impaired and a uniform coating liquid can be obtained. For example, mixing can be performed using an apparatus such as a stirrer, a dispenser, a planetary mixer, or a rotation / revolution type mixer.

[Coating layer forming process]
In this step, the polymer film substrate is coated with the coating liquid and dried to form a coating layer. The coating layer may be left coated with the polymer film base material or may be peeled off from the polymer film base material when it is subjected to a subsequent conductive film forming step.

(Polymer film base material)
A polymer film base material has a coating layer formed on its surface, and when the coating layer on the polymer film base material is stretched together with the polymer film base material in a later step, a stretchable resin is used. Is used. On the other hand, when the coating layer is peeled from the polymer film base material and only the coating layer is stretched, a resin capable of peeling the coating layer is used.

As the stretchable resin, a thermoplastic resin is preferable. Further, it can also be used in an embodiment in which a thermosetting resin or an ultraviolet curable resin, an uncured or semi-cured thermosetting resin, an ultraviolet curable resin or the like is cured after stretching.
Examples of such resins include polyamide resins; polyolefin resins such as polyethylene and polypropylene; polyester resins such as polylactic acid, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polyethylene terephthalate isophthalate; polyacetal resin; polycarbonate resin; acrylate. Resins; polystyrene resins; polyurethane resins, polyvinyl chloride resins; polyphenylene resins, fluororesins and the like can be mentioned. These may be used alone or in combination of two or more. Of these, polyolefin resins and polyester resins are preferable, and among these, polyethylene, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate are particularly preferable. Further, the polymer film base material may be a laminate made of the above-mentioned one type or two or more types of resins.
The polymer film base material using these resins may be subjected to surface treatment such as primer treatment or corona treatment from the viewpoint of preventing peeling of the coating layer during stretching.
Further, a known additive may be added to the polymer film base material. Examples of the additive include an antioxidant; a matting agent; a pigment; a filler such as silica, calcium carbonate, kaolin, and titanium dioxide; and an antistatic agent.

Examples of the peelable resin include polyolefin resins similar to the stretchable resin described above, fluororesins such as polytetrafluoroethylene, and the like, and these may be used alone or in combination of two or more. You may. Further, any resin can be used as long as it is a resin film that has undergone a mold release treatment.

The thickness of the polymer film base material can be appropriately set depending on the material of the polymer film base material, the use of the conductive film, etc., but in either case of stretching together with the coating layer or in the case of peeling off the coating layer. However, from the viewpoint of mechanical strength, handleability, etc., it is preferably 5 to 300 μm, more preferably 7 to 250 μm, and further preferably 10 to 200 μm.

(Formation of coating layer)
The method for coating the polymer film substrate with the coating liquid is not particularly limited, and a known method can be used. For example, a spray method, a flow coating method, a roll coating method, a gravure roll coating method, a knife coating method, a dip coating method, a comma coating method, a lip direct method, a slit reverse method, a blade coating method and the like can be mentioned. These coating methods may be performed once, or may be repeated a plurality of times.

Then, the coating layer is formed by drying the coating liquid on the coated polymer film base material. The coating and drying of the coating liquid may be repeated a plurality of times to form a coating layer having a desired thickness.
From the viewpoint of efficiency, the drying is preferably performed by heating within a range in which the composite particles constituting the coating layer, the resin of the binder, and the like do not cause thermal deterioration. The drying conditions can be appropriately determined according to the boiling point, volatility, etc. of the dispersion medium of the coating liquid. The drying temperature is preferably 15 to 200 ° C, more preferably 30 to 170 ° C, and even more preferably 50 to 150 ° C. For efficiency, it may be dried under reduced pressure. As the drying means, for example, a hot air drying furnace, an infrared drying furnace, a hot plate, or the like can be used.

When the coating layer on the polymer film substrate is stretched together with the polymer film substrate in the subsequent conductive film forming step, the coating layer is preferably formed by in-line coating which is continuously performed in the step. .. According to the in-line coating, the manufacturing equipment can be reduced and the manufacturing cost can be suppressed. Further, the thickness of the conductive film can be adjusted by the draw ratio.

[Conducting film forming process]
In this step, the coating layer is heat-stretched to form a conductive film. In the heat stretching, as described above, the coating layer on the polymer film base material may be stretched together with the polymer film base material, or the coating layer may be peeled off from the polymer film base material to remove only the coating layer. It may be stretched.

(Heat stretching)
The stretching method is not particularly limited, and can be appropriately selected depending on the material of the binder and the polymer film base material, the application application and performance of the conductive film, and even uniaxial stretching is biaxial stretching. You may.
The stretching temperature is set higher than the glass transition temperature of the polymer seed particles protected and colloidalized with polyanions, and is preferably 10 ° C. or higher, more preferably 15 ° C. or higher. When the stretching temperature is higher than the glass transition temperature, it is possible to suppress a decrease in the conductivity of the conductive film formed by stretching.
The upper limit of the absolute value of the temperature difference between the stretching temperature and the glass transition temperature is not particularly limited as long as the resin constituting the polymer seed particles is not deteriorated by heating and stretching.
When the coating layer is stretched together with the polymer film base material, the stretching temperature is preferably equal to or higher than the glass transition temperature of the resin constituting the polymer film base material, and more preferably 10 ° C. or more higher than the glass transition temperature. More preferably, the temperature is 15 ° C. or higher higher than the glass transition temperature.
Further, in both the case where the coating layer is stretched together with the polymer film base material and the case where only the coating layer is stretched, the temperature range is set to 30 to 30 so that the composite particles constituting the coating layer, the resin of the binder, etc. do not deteriorate. The temperature is preferably 200 ° C, more preferably 40 to 170 ° C, and even more preferably 50 to 150 ° C.
The draw ratio is appropriately set according to the content of the composite particles, the thickness of the coating layer, the desired thickness of the conductive film, etc., but is 110 to 2000% from the viewpoint of the mechanical strength and conductivity of the conductive film. It is preferably 115 to 1700%, more preferably 120 to 1500%. The stretching ratio is a value calculated by the following formula for the length in the stretching direction.
Stretching rate [%] = {(length after stretching-length before stretching) / length before stretching} x 100

[Conducting film]
The conductive film obtained by the production method of the present invention can also be obtained as a transparent conductive film because the composite particles and the binder can be made of a transparent material. Therefore, the conductive film of the present invention can be suitably used as a transparent conductive film in, for example, a touch panel, an organic electroluminescence element, a thin film solar cell, or the like.
Further, the conductive film obtained by stretching the coating layer together with the polymer film base material and the polymer film base material can be applied as an antistatic film. That is, the method for producing a conductive film according to the present invention can be applied to a method for producing an antistatic film composed of a conductive film and a polymer film base material.
In addition to the above, the conductive film of the present invention can be suitably applied to resin films and the like that are required to have conductivity and antistatic properties in the fields of electricity and electronics or other fields.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

[Physical property measurement and evaluation method]
The methods for measuring and evaluating various physical properties in the following examples and comparative examples are as follows.
(1) Solid content concentration The sample was measured using an infrared moisture meter (FD-720, manufactured by Kett Science Institute Co., Ltd.) under the conditions of a sample weight of 10 g and 110 ° C. for 30 minutes. The solid content concentration is a non-volatile content calculated by the following formula for a predetermined amount of sample.
Non-volatile content [%] = (weight after drying / weight before drying) x 100
(2) pH
The pH of the dispersion was measured at 25 ° C. with a pH meter (HM-30G, manufactured by DKK-TOA CORPORATION).
(3) Particle size of polymer seed particles (d50)
The particle size distribution of the polymer seed particles was measured with a Microtrack particle size analyzer (Microtrack UPA, manufactured by Nikkiso Co., Ltd.) to determine a 50% median diameter d50 on a volume basis.
(4) Glass transition temperature (Tg)
About 2 g of the polymer seed particles were dried in a dryer at 110 ° C. for 1 hour, and the obtained dried product was pulverized in a mortar.
Approximately 20 mg of the obtained pulverized product was weighed in an aluminum sample container for DSC, and heated at a heating rate of 20 ° C./min in a nitrogen gas atmosphere. The mixture was heated to 150 ° C. and held for 1 hour. Then, the sample was taken out from the DSC, the sample container was quickly covered, returned to the DSC, and cooled to 0 ° C. in 5 to 30 minutes using liquid nitrogen. In accordance with JIS K 7121: 2012, the heating rate was again 20 ° C./min. The glass transition temperature (intermediate glass transition temperature) was measured by heating to 150 ° C.
(5) Thickness For each of the coating layer and the conductive film, the thickness at any three points was measured with a micrometer, and the average value of each of these was taken as the thickness in Table 1.
(6) Conductivity The surface resistance of the coating layer and the conductive film was measured with a simple low resistivity meter (Loresta GP MCP-T610 manufactured by Mitsubishi Chemical Corporation), and the following formula was obtained from the thickness of the coating layer and the conductive film. The conductivity was calculated by
Conductivity = 1 / (surface resistance x film thickness)
(7) Transparency A coating solution diluted 5 times was applied on a smooth transparent glass plate with a bar coater and dried at 80 ° C. for 10 minutes to form a coating film having a thickness of about 100 nm. The transparency of the coating film was visually confirmed.

[Example 1]
(Preparation of dispersion of polymer seed particles protected and colloidalized with polyanion)
86 g of styrene, 49 g of 2-ethylhexyl acrylate, 15 g of divinylbenzene and 500 g of a 22 mass% aqueous solution of sodium polystyrene sulfonate (Polynas PS-5 manufactured by Tosoh Organic Chemical Co., Ltd., weight average molecular weight: about 120,000) were stirred and mixed, and simply mixed. A molecular weight mixture was prepared.
On the other hand, 1000 g of a 22 mass% aqueous solution of sodium polystyrene sulfonate (same as above) was heated to 80 ° C. with stirring, and 2 g of potassium persulfate was added thereto.
To this solution, 40 g of the monomer mixed solution and a 2.5 mass% potassium persulfate aqueous solution were added dropwise over 2 hours and 2.5 hours, respectively. After completion of the dropping, the mixture was kept at 80 ° C. for 2 hours, and then cooled to room temperature (25 ° C.).
To the obtained reaction solution, 1500 ml of a cation exchange resin (IR120B-H manufactured by Organo Corporation) and 1500 ml of an anion exchange resin (IRA410-OH manufactured by Organo Corporation) were added, and the mixture was stirred for 12 hours and then the ion exchange resin. I broke up. Polymer seed particles (Tg: 30 ° C., particle size) protected and colloidalized with polyanions by adding ion-exchanged water (hereinafter, simply referred to as water) to adjust the solid content concentration to 15.0% by mass. A dispersion of d50: 0.46 μm) was obtained.

(Preparation of dispersion containing composite particles)
In a 1 L polyethylene container, stir 223.2 g of water, 31.5 g of a 12% by mass aqueous solution of sodium polystyrene sulfonate, and 34.0 g of a dispersion of polymer seed particles protected and colloidalized with the polyanion prepared above at 32 ° C. Mixed. To this mixed solution, 2.80 g of 3,4-ethylenedioxythiophene was added at 32 ° C., emulsified and mixed with a homomixer (Robomix manufactured by Tokushu Kika Kogyo Co., Ltd .; 4000 rpm) for 30 minutes, and the monomer was obtained. A dispersion was prepared (sulphonic acid group content per 1 mol of 3,4-ethylenedioxythiophene: 1.9 mol). The sulfonic acid group is derived from a 12% by mass aqueous solution of sodium polystyrene sulfonate and sodium polystyrene sulfonate in the dispersion.
The monomer dispersion is put into a 1 L stainless steel container to which a high-share mixer (Pacific Machinery & Engineering Co., Ltd., Milder 303V; 5000 rpm) and a circulation pump are connected, and circulated at 32 ° C. by a stirring blade and a high-share mixer. While stirring, 5.89 g of sodium peroxodisulfate and 6.88 g of a 1% by mass aqueous solution of iron (III) sulfate hexahydrate were added as oxidizing agents, and a polymerization reaction was carried out for 24 hours.
221 g of the obtained reaction solution and 79 g of water were put into a 1 L stainless steel container to which a high-share mixer (manufactured by IKA, Magic Lab; 1800 rpm) and a circulation pump were connected, and the mixture was stirred while circulating for 12 hours for dispersion treatment. Was done.
To 300 g of the obtained dispersion, 300 mL of a cation exchange resin (same as above) and 300 mL of an anion exchange resin (same as above) were added, and after stirring for 6 hours, the ion exchange resin was filtered off. The body and oxidant were removed. The pH was adjusted to 4.4 with aqueous ammonia to obtain a dispersion (solid content concentration: 2.4% by mass) containing composite particles of polymer seed particles protected and colloidalized with polyanions and conjugated conductive polymers.

(Preparation of conductive film)
125.0 g of the composite particle-containing dispersion (solid content concentration 2.4% by mass) prepared above, polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA217, saponification degree: about 87 to 89 mol%, degree of polymerization: about 1,700 ) 30.0 g of a 15 mass% aqueous solution, 5.0 g of ethylene glycol, 4.5 g of glycerin, 23.0 g of water, and 0.2 g of an antifoaming agent (Nopco 1407-H, manufactured by Sannopco Co., Ltd.) are stirred and mixed, and the coating liquid (coating liquid () The solid content concentration was 4.0% by mass, and the composite particle content in the solid content was 40% by mass).
When the transparency of the coating film of the coating liquid was evaluated by the above-mentioned method, it was confirmed that the coating film was transparent.
This coating liquid was poured into a 7 cm × 17 cm mold on a smooth polyethylene film base material and dried at 23 ° C. and 50% relative humidity for 2 days at 80 ° C. for 1 hour to form a coating layer from the base material. It peeled off.
The coating layer was cut out to a size of 15 mm × 45 mm, and this was fixed to a precision universal testing machine (manufactured by Shimadzu Corporation, Autograph AG-X, 20 kN) in an 85 ° C. constant temperature bath at a distance between chucks of 15 mm. After holding in a constant temperature bath for 3 minutes and confirming that the surface of the coating layer reached 80 ° C. (stretching temperature), the stretching speed was 30 mm / min. It was stretched by about 400% to prepare a conductive film.
The thickness and conductivity of the coating layer and the conductive film are shown in Table 1 below. In this example, the conductivity evaluation of the conductive film was performed only on the conductive film (coating layer) from the viewpoint of eliminating the influence of the base material.

[Examples 2 to 4, Comparative Examples 1 to 3]
In Example 1, styrene, 2-ethylhexyl acrylate and divinylbenzene in the monomer mixed solution for obtaining the dispersion liquid of the polymer seed particles were changed to the compounding composition shown in Table 1 below, and the coating liquid was changed to Table 1 below. The coating layer and the conductive film were prepared in the same manner as in Example 1 by changing to the compounding composition shown in 1.
The film thickness and conductivity of these coating layers and conductive films are shown in Table 1 below.
When the transparency of the coating film of each coating liquid was evaluated by the above-mentioned method, it was confirmed that the coating film was transparent.

When the thickness and conductivity of the conductive film stretched at a predetermined stretching ratio were measured for each of the coating layers produced in the above Examples and Comparative Examples, and the coating layer (conductive film before stretching) was set to 100 [%]. The change in the ratio of conductivity was determined. The results are shown in Table 2 below, and the relationship between the draw ratio and the thickness is shown as a graph in FIGS. 1 to 3 for each of the coating liquids having the same content of composite particles in the solid content.

As can be seen from the graphs shown in Tables 1 and 2 and FIGS. 1 to 3, when the glass transition temperature of the polymer seed particles is lower than the stretching temperature of 80 ° C. in heat stretching (Examples 1 to 4), it is relative to the stretching ratio. It was confirmed that the decrease in conductivity was suppressed.

Claims (14)

A step of preparing a coating liquid containing composite particles of a polymer seed particle protected and colloidalized with a polyanion and a conjugated conductive polymer, and a binder.
A step of coating the polymer film base material with the coating liquid and drying to form a coating layer,
Including a step of heating and stretching the coating layer to form a conductive film.
The protective colloidalized polymer seed particles are a copolymer of at least one of methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate, styrene, and a polyfunctional vinyl compound, and the copolymer weight thereof. The content of the polyfunctional vinyl compound in the monomer for coalescence is 25% by mass or less, and the content is 25% by mass or less.
The glass transition temperature of the protective colloid polymer seed particles, rather lower than the stretching temperature in the heat stretching,
A method for producing a conductive film, wherein the binder can be stretched at the stretching temperature. The method for producing a conductive film according to claim 1, wherein the glass transition temperature of the protective colloidalized polymer seed particles is 60 ° C. or lower, which is 10 ° C. or higher lower than the stretching temperature. The method for producing a conductive film according to claim 1 or 2 , wherein the content of the composite particles in the solid content of the coating liquid is 1 to 70% by mass. The method for producing a conductive film according to any one of claims 1 to 3 , wherein the composite particles are provided as a dispersion in the step of preparing the coating liquid. The method for producing a conductive film according to any one of claims 1 to 4 , wherein the coating liquid contains water as an aqueous medium and the binder is a water-soluble thermoplastic resin. Wherein the binder is a port polyvinyl alcohol resins, method for producing a conductive film according to any one of claims 1-5. The monomer which is a constituent unit of the conjugated conductive copolymer is selected from pyrrole which may have a substituent, aniline which may have a substituent, and thiophene which may have a substituent. The method for producing a conductive film according to any one of claims 1 to 6 , which comprises one or more of the above-mentioned materials. The method for producing a conductive film according to any one of claims 1 to 7 , wherein the monomer, which is a constituent unit of the conjugated conductive copolymer, contains a compound represented by the following formula (1).

(In the formula (1), R ¹ and R ² independently have a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms which may have a substituent, and a carbon number which may have a substituent. Any of 1 to 18 alkoxy groups or alkyl thio groups having 1 to 18 carbon atoms which may have a substituent, or a substituent in which R ¹ and R ² are bonded to each other to form a ring. An alicyclic ring having 3 to 10 carbon atoms which may have a substituent, an aromatic ring having 6 to 10 carbon atoms which may have a substituent, and an oxygen atom-containing complex having 3 to 10 ring members which may have a substituent. A ring, a sulfur atom-containing heterocycle having 3 to 10 ring members which may have a substituent, or a sulfur atom and oxygen atom-containing heterocycle having 3 to 10 ring members which may have a substituent are shown.) The method for producing a conductive film according to any one of claims 1 to 8 , wherein the polyanion is a polymer having a group consisting of sulfonic acid or a salt thereof. Any of claims 1 to 9 , wherein the content of the anionic group in the polyanion is 0.25 to 30 mol with respect to 1 mol of the monomer which is a constituent unit of the conjugated conductive copolymer. The method for producing a conductive film according to item 1. The method for producing a conductive film according to any one of claims 1 to 10 , wherein the conductive film is a transparent conductive film. The method for producing a conductive film according to any one of claims 1 to 11, wherein in the heat stretching, the coating layer is peeled from the polymer film base material and then only the coating layer is stretched. The method for producing a conductive film according to any one of claims 1 to 11, wherein in the heat stretching, the coating layer on the polymer film base material is stretched together with the polymer film base material. A manufacturing method of a method of manufacturing the antistatic film, the production of antistatic film characterized by by the method according to claim 1 3, to obtain an antistatic film comprising the conductive layer and the polymeric film substrate Method.

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